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Diffstat (limited to 'gcc-4.9/gcc/cp/pt.c')
| -rw-r--r-- | gcc-4.9/gcc/cp/pt.c | 21975 |
1 files changed, 21975 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/cp/pt.c b/gcc-4.9/gcc/cp/pt.c new file mode 100644 index 000000000..c791d031a --- /dev/null +++ b/gcc-4.9/gcc/cp/pt.c @@ -0,0 +1,21975 @@ +/* Handle parameterized types (templates) for GNU -*- C++ -*-. + Copyright (C) 1992-2014 Free Software Foundation, Inc. + Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing. + Rewritten by Jason Merrill (jason@cygnus.com). + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +/* Known bugs or deficiencies include: + + all methods must be provided in header files; can't use a source + file that contains only the method templates and "just win". */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "stringpool.h" +#include "varasm.h" +#include "attribs.h" +#include "stor-layout.h" +#include "intl.h" +#include "pointer-set.h" +#include "flags.h" +#include "cp-tree.h" +#include "c-family/c-common.h" +#include "c-family/c-objc.h" +#include "cp-objcp-common.h" +#include "tree-inline.h" +#include "decl.h" +#include "toplev.h" +#include "timevar.h" +#include "tree-iterator.h" +#include "type-utils.h" +#include "gimplify.h" + +/* The type of functions taking a tree, and some additional data, and + returning an int. */ +typedef int (*tree_fn_t) (tree, void*); + +/* The PENDING_TEMPLATES is a TREE_LIST of templates whose + instantiations have been deferred, either because their definitions + were not yet available, or because we were putting off doing the work. */ +struct GTY ((chain_next ("%h.next"))) pending_template { + struct pending_template *next; + struct tinst_level *tinst; +}; + +static GTY(()) struct pending_template *pending_templates; +static GTY(()) struct pending_template *last_pending_template; + +int processing_template_parmlist; +static int template_header_count; + +static GTY(()) tree saved_trees; +static vec<int> inline_parm_levels; + +static GTY(()) struct tinst_level *current_tinst_level; + +static GTY(()) tree saved_access_scope; + +/* Live only within one (recursive) call to tsubst_expr. We use + this to pass the statement expression node from the STMT_EXPR + to the EXPR_STMT that is its result. */ +static tree cur_stmt_expr; + +/* True if we've recursed into fn_type_unification too many times. */ +static bool excessive_deduction_depth; + +typedef struct GTY(()) spec_entry +{ + tree tmpl; + tree args; + tree spec; +} spec_entry; + +static GTY ((param_is (spec_entry))) + htab_t decl_specializations; + +static GTY ((param_is (spec_entry))) + htab_t type_specializations; + +/* Contains canonical template parameter types. The vector is indexed by + the TEMPLATE_TYPE_IDX of the template parameter. Each element is a + TREE_LIST, whose TREE_VALUEs contain the canonical template + parameters of various types and levels. */ +static GTY(()) vec<tree, va_gc> *canonical_template_parms; + +#define UNIFY_ALLOW_NONE 0 +#define UNIFY_ALLOW_MORE_CV_QUAL 1 +#define UNIFY_ALLOW_LESS_CV_QUAL 2 +#define UNIFY_ALLOW_DERIVED 4 +#define UNIFY_ALLOW_INTEGER 8 +#define UNIFY_ALLOW_OUTER_LEVEL 16 +#define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32 +#define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64 + +enum template_base_result { + tbr_incomplete_type, + tbr_ambiguous_baseclass, + tbr_success +}; + +static void push_access_scope (tree); +static void pop_access_scope (tree); +static bool resolve_overloaded_unification (tree, tree, tree, tree, + unification_kind_t, int, + bool); +static int try_one_overload (tree, tree, tree, tree, tree, + unification_kind_t, int, bool, bool); +static int unify (tree, tree, tree, tree, int, bool); +static void add_pending_template (tree); +static tree reopen_tinst_level (struct tinst_level *); +static tree tsubst_initializer_list (tree, tree); +static tree get_class_bindings (tree, tree, tree, tree); +static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t, + bool, bool); +static tree coerce_innermost_template_parms (tree, tree, tree, tsubst_flags_t, + bool, bool); +static void tsubst_enum (tree, tree, tree); +static tree add_to_template_args (tree, tree); +static tree add_outermost_template_args (tree, tree); +static bool check_instantiated_args (tree, tree, tsubst_flags_t); +static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*, + tree); +static int type_unification_real (tree, tree, tree, const tree *, + unsigned int, int, unification_kind_t, int, + vec<deferred_access_check, va_gc> **, + bool); +static void note_template_header (int); +static tree convert_nontype_argument_function (tree, tree); +static tree convert_nontype_argument (tree, tree, tsubst_flags_t); +static tree convert_template_argument (tree, tree, tree, + tsubst_flags_t, int, tree); +static int for_each_template_parm (tree, tree_fn_t, void*, + struct pointer_set_t*, bool); +static tree expand_template_argument_pack (tree); +static tree build_template_parm_index (int, int, int, tree, tree); +static bool inline_needs_template_parms (tree, bool); +static void push_inline_template_parms_recursive (tree, int); +static tree retrieve_local_specialization (tree); +static void register_local_specialization (tree, tree); +static hashval_t hash_specialization (const void *p); +static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t); +static int mark_template_parm (tree, void *); +static int template_parm_this_level_p (tree, void *); +static tree tsubst_friend_function (tree, tree); +static tree tsubst_friend_class (tree, tree); +static int can_complete_type_without_circularity (tree); +static tree get_bindings (tree, tree, tree, bool); +static int template_decl_level (tree); +static int check_cv_quals_for_unify (int, tree, tree); +static void template_parm_level_and_index (tree, int*, int*); +static int unify_pack_expansion (tree, tree, tree, + tree, unification_kind_t, bool, bool); +static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree); +static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree); +static tree tsubst_template_parms (tree, tree, tsubst_flags_t); +static void regenerate_decl_from_template (tree, tree); +static tree most_specialized_class (tree, tsubst_flags_t); +static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int); +static tree tsubst_arg_types (tree, tree, tree, tsubst_flags_t, tree); +static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree); +static bool check_specialization_scope (void); +static tree process_partial_specialization (tree); +static void set_current_access_from_decl (tree); +static enum template_base_result get_template_base (tree, tree, tree, tree, + bool , tree *); +static tree try_class_unification (tree, tree, tree, tree, bool); +static int coerce_template_template_parms (tree, tree, tsubst_flags_t, + tree, tree); +static bool template_template_parm_bindings_ok_p (tree, tree); +static int template_args_equal (tree, tree); +static void tsubst_default_arguments (tree, tsubst_flags_t); +static tree for_each_template_parm_r (tree *, int *, void *); +static tree copy_default_args_to_explicit_spec_1 (tree, tree); +static void copy_default_args_to_explicit_spec (tree); +static int invalid_nontype_parm_type_p (tree, tsubst_flags_t); +static bool dependent_template_arg_p (tree); +static bool any_template_arguments_need_structural_equality_p (tree); +static bool dependent_type_p_r (tree); +static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool); +static tree tsubst_copy (tree, tree, tsubst_flags_t, tree); +static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree); +static tree tsubst_decl (tree, tree, tsubst_flags_t); +static void perform_typedefs_access_check (tree tmpl, tree targs); +static void append_type_to_template_for_access_check_1 (tree, tree, tree, + location_t); +static tree listify (tree); +static tree listify_autos (tree, tree); +static tree template_parm_to_arg (tree t); +static tree current_template_args (void); +static tree tsubst_template_parm (tree, tree, tsubst_flags_t); +static tree instantiate_alias_template (tree, tree, tsubst_flags_t); + +/* Make the current scope suitable for access checking when we are + processing T. T can be FUNCTION_DECL for instantiated function + template, VAR_DECL for static member variable, or TYPE_DECL for + alias template (needed by instantiate_decl). */ + +static void +push_access_scope (tree t) +{ + gcc_assert (VAR_OR_FUNCTION_DECL_P (t) + || TREE_CODE (t) == TYPE_DECL); + + if (DECL_FRIEND_CONTEXT (t)) + push_nested_class (DECL_FRIEND_CONTEXT (t)); + else if (DECL_CLASS_SCOPE_P (t)) + push_nested_class (DECL_CONTEXT (t)); + else + push_to_top_level (); + + if (TREE_CODE (t) == FUNCTION_DECL) + { + saved_access_scope = tree_cons + (NULL_TREE, current_function_decl, saved_access_scope); + current_function_decl = t; + } +} + +/* Restore the scope set up by push_access_scope. T is the node we + are processing. */ + +static void +pop_access_scope (tree t) +{ + if (TREE_CODE (t) == FUNCTION_DECL) + { + current_function_decl = TREE_VALUE (saved_access_scope); + saved_access_scope = TREE_CHAIN (saved_access_scope); + } + + if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t)) + pop_nested_class (); + else + pop_from_top_level (); +} + +/* Do any processing required when DECL (a member template + declaration) is finished. Returns the TEMPLATE_DECL corresponding + to DECL, unless it is a specialization, in which case the DECL + itself is returned. */ + +tree +finish_member_template_decl (tree decl) +{ + if (decl == error_mark_node) + return error_mark_node; + + gcc_assert (DECL_P (decl)); + + if (TREE_CODE (decl) == TYPE_DECL) + { + tree type; + + type = TREE_TYPE (decl); + if (type == error_mark_node) + return error_mark_node; + if (MAYBE_CLASS_TYPE_P (type) + && CLASSTYPE_TEMPLATE_INFO (type) + && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type)) + { + tree tmpl = CLASSTYPE_TI_TEMPLATE (type); + check_member_template (tmpl); + return tmpl; + } + return NULL_TREE; + } + else if (TREE_CODE (decl) == FIELD_DECL) + error ("data member %qD cannot be a member template", decl); + else if (DECL_TEMPLATE_INFO (decl)) + { + if (!DECL_TEMPLATE_SPECIALIZATION (decl)) + { + check_member_template (DECL_TI_TEMPLATE (decl)); + return DECL_TI_TEMPLATE (decl); + } + else + return decl; + } + else + error ("invalid member template declaration %qD", decl); + + return error_mark_node; +} + +/* Create a template info node. */ + +tree +build_template_info (tree template_decl, tree template_args) +{ + tree result = make_node (TEMPLATE_INFO); + TI_TEMPLATE (result) = template_decl; + TI_ARGS (result) = template_args; + return result; +} + +/* Return the template info node corresponding to T, whatever T is. */ + +tree +get_template_info (const_tree t) +{ + tree tinfo = NULL_TREE; + + if (!t || t == error_mark_node) + return NULL; + + if (DECL_P (t) && DECL_LANG_SPECIFIC (t)) + tinfo = DECL_TEMPLATE_INFO (t); + + if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t)) + t = TREE_TYPE (t); + + if (OVERLOAD_TYPE_P (t)) + tinfo = TYPE_TEMPLATE_INFO (t); + else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM) + tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t); + + return tinfo; +} + +/* Returns the template nesting level of the indicated class TYPE. + + For example, in: + template <class T> + struct A + { + template <class U> + struct B {}; + }; + + A<T>::B<U> has depth two, while A<T> has depth one. + Both A<T>::B<int> and A<int>::B<U> have depth one, if + they are instantiations, not specializations. + + This function is guaranteed to return 0 if passed NULL_TREE so + that, for example, `template_class_depth (current_class_type)' is + always safe. */ + +int +template_class_depth (tree type) +{ + int depth; + + for (depth = 0; + type && TREE_CODE (type) != NAMESPACE_DECL; + type = (TREE_CODE (type) == FUNCTION_DECL) + ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type)) + { + tree tinfo = get_template_info (type); + + if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo)) + && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo)))) + ++depth; + } + + return depth; +} + +/* Subroutine of maybe_begin_member_template_processing. + Returns true if processing DECL needs us to push template parms. */ + +static bool +inline_needs_template_parms (tree decl, bool nsdmi) +{ + if (!decl || (!nsdmi && ! DECL_TEMPLATE_INFO (decl))) + return false; + + return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl))) + > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl))); +} + +/* Subroutine of maybe_begin_member_template_processing. + Push the template parms in PARMS, starting from LEVELS steps into the + chain, and ending at the beginning, since template parms are listed + innermost first. */ + +static void +push_inline_template_parms_recursive (tree parmlist, int levels) +{ + tree parms = TREE_VALUE (parmlist); + int i; + + if (levels > 1) + push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1); + + ++processing_template_decl; + current_template_parms + = tree_cons (size_int (processing_template_decl), + parms, current_template_parms); + TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1; + + begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec, + NULL); + for (i = 0; i < TREE_VEC_LENGTH (parms); ++i) + { + tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i)); + + if (parm == error_mark_node) + continue; + + gcc_assert (DECL_P (parm)); + + switch (TREE_CODE (parm)) + { + case TYPE_DECL: + case TEMPLATE_DECL: + pushdecl (parm); + break; + + case PARM_DECL: + { + /* Make a CONST_DECL as is done in process_template_parm. + It is ugly that we recreate this here; the original + version built in process_template_parm is no longer + available. */ + tree decl = build_decl (DECL_SOURCE_LOCATION (parm), + CONST_DECL, DECL_NAME (parm), + TREE_TYPE (parm)); + DECL_ARTIFICIAL (decl) = 1; + TREE_CONSTANT (decl) = 1; + TREE_READONLY (decl) = 1; + DECL_INITIAL (decl) = DECL_INITIAL (parm); + SET_DECL_TEMPLATE_PARM_P (decl); + pushdecl (decl); + } + break; + + default: + gcc_unreachable (); + } + } +} + +/* Restore the template parameter context for a member template, a + friend template defined in a class definition, or a non-template + member of template class. */ + +void +maybe_begin_member_template_processing (tree decl) +{ + tree parms; + int levels = 0; + bool nsdmi = TREE_CODE (decl) == FIELD_DECL; + + if (nsdmi) + decl = (CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl)) + ? CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (decl)) + : NULL_TREE); + + if (inline_needs_template_parms (decl, nsdmi)) + { + parms = DECL_TEMPLATE_PARMS (most_general_template (decl)); + levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl; + + if (DECL_TEMPLATE_SPECIALIZATION (decl)) + { + --levels; + parms = TREE_CHAIN (parms); + } + + push_inline_template_parms_recursive (parms, levels); + } + + /* Remember how many levels of template parameters we pushed so that + we can pop them later. */ + inline_parm_levels.safe_push (levels); +} + +/* Undo the effects of maybe_begin_member_template_processing. */ + +void +maybe_end_member_template_processing (void) +{ + int i; + int last; + + if (inline_parm_levels.length () == 0) + return; + + last = inline_parm_levels.pop (); + for (i = 0; i < last; ++i) + { + --processing_template_decl; + current_template_parms = TREE_CHAIN (current_template_parms); + poplevel (0, 0, 0); + } +} + +/* Return a new template argument vector which contains all of ARGS, + but has as its innermost set of arguments the EXTRA_ARGS. */ + +static tree +add_to_template_args (tree args, tree extra_args) +{ + tree new_args; + int extra_depth; + int i; + int j; + + if (args == NULL_TREE || extra_args == error_mark_node) + return extra_args; + + extra_depth = TMPL_ARGS_DEPTH (extra_args); + new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth); + + for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i) + SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i)); + + for (j = 1; j <= extra_depth; ++j, ++i) + SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j)); + + return new_args; +} + +/* Like add_to_template_args, but only the outermost ARGS are added to + the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH + (EXTRA_ARGS) levels are added. This function is used to combine + the template arguments from a partial instantiation with the + template arguments used to attain the full instantiation from the + partial instantiation. */ + +static tree +add_outermost_template_args (tree args, tree extra_args) +{ + tree new_args; + + /* If there are more levels of EXTRA_ARGS than there are ARGS, + something very fishy is going on. */ + gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args)); + + /* If *all* the new arguments will be the EXTRA_ARGS, just return + them. */ + if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args)) + return extra_args; + + /* For the moment, we make ARGS look like it contains fewer levels. */ + TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args); + + new_args = add_to_template_args (args, extra_args); + + /* Now, we restore ARGS to its full dimensions. */ + TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args); + + return new_args; +} + +/* Return the N levels of innermost template arguments from the ARGS. */ + +tree +get_innermost_template_args (tree args, int n) +{ + tree new_args; + int extra_levels; + int i; + + gcc_assert (n >= 0); + + /* If N is 1, just return the innermost set of template arguments. */ + if (n == 1) + return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args)); + + /* If we're not removing anything, just return the arguments we were + given. */ + extra_levels = TMPL_ARGS_DEPTH (args) - n; + gcc_assert (extra_levels >= 0); + if (extra_levels == 0) + return args; + + /* Make a new set of arguments, not containing the outer arguments. */ + new_args = make_tree_vec (n); + for (i = 1; i <= n; ++i) + SET_TMPL_ARGS_LEVEL (new_args, i, + TMPL_ARGS_LEVEL (args, i + extra_levels)); + + return new_args; +} + +/* The inverse of get_innermost_template_args: Return all but the innermost + EXTRA_LEVELS levels of template arguments from the ARGS. */ + +static tree +strip_innermost_template_args (tree args, int extra_levels) +{ + tree new_args; + int n = TMPL_ARGS_DEPTH (args) - extra_levels; + int i; + + gcc_assert (n >= 0); + + /* If N is 1, just return the outermost set of template arguments. */ + if (n == 1) + return TMPL_ARGS_LEVEL (args, 1); + + /* If we're not removing anything, just return the arguments we were + given. */ + gcc_assert (extra_levels >= 0); + if (extra_levels == 0) + return args; + + /* Make a new set of arguments, not containing the inner arguments. */ + new_args = make_tree_vec (n); + for (i = 1; i <= n; ++i) + SET_TMPL_ARGS_LEVEL (new_args, i, + TMPL_ARGS_LEVEL (args, i)); + + return new_args; +} + +/* We've got a template header coming up; push to a new level for storing + the parms. */ + +void +begin_template_parm_list (void) +{ + /* We use a non-tag-transparent scope here, which causes pushtag to + put tags in this scope, rather than in the enclosing class or + namespace scope. This is the right thing, since we want + TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a + global template class, push_template_decl handles putting the + TEMPLATE_DECL into top-level scope. For a nested template class, + e.g.: + + template <class T> struct S1 { + template <class T> struct S2 {}; + }; + + pushtag contains special code to call pushdecl_with_scope on the + TEMPLATE_DECL for S2. */ + begin_scope (sk_template_parms, NULL); + ++processing_template_decl; + ++processing_template_parmlist; + note_template_header (0); +} + +/* This routine is called when a specialization is declared. If it is + invalid to declare a specialization here, an error is reported and + false is returned, otherwise this routine will return true. */ + +static bool +check_specialization_scope (void) +{ + tree scope = current_scope (); + + /* [temp.expl.spec] + + An explicit specialization shall be declared in the namespace of + which the template is a member, or, for member templates, in the + namespace of which the enclosing class or enclosing class + template is a member. An explicit specialization of a member + function, member class or static data member of a class template + shall be declared in the namespace of which the class template + is a member. */ + if (scope && TREE_CODE (scope) != NAMESPACE_DECL) + { + error ("explicit specialization in non-namespace scope %qD", scope); + return false; + } + + /* [temp.expl.spec] + + In an explicit specialization declaration for a member of a class + template or a member template that appears in namespace scope, + the member template and some of its enclosing class templates may + remain unspecialized, except that the declaration shall not + explicitly specialize a class member template if its enclosing + class templates are not explicitly specialized as well. */ + if (current_template_parms) + { + error ("enclosing class templates are not explicitly specialized"); + return false; + } + + return true; +} + +/* We've just seen template <>. */ + +bool +begin_specialization (void) +{ + begin_scope (sk_template_spec, NULL); + note_template_header (1); + return check_specialization_scope (); +} + +/* Called at then end of processing a declaration preceded by + template<>. */ + +void +end_specialization (void) +{ + finish_scope (); + reset_specialization (); +} + +/* Any template <>'s that we have seen thus far are not referring to a + function specialization. */ + +void +reset_specialization (void) +{ + processing_specialization = 0; + template_header_count = 0; +} + +/* We've just seen a template header. If SPECIALIZATION is nonzero, + it was of the form template <>. */ + +static void +note_template_header (int specialization) +{ + processing_specialization = specialization; + template_header_count++; +} + +/* We're beginning an explicit instantiation. */ + +void +begin_explicit_instantiation (void) +{ + gcc_assert (!processing_explicit_instantiation); + processing_explicit_instantiation = true; +} + + +void +end_explicit_instantiation (void) +{ + gcc_assert (processing_explicit_instantiation); + processing_explicit_instantiation = false; +} + +/* An explicit specialization or partial specialization of TMPL is being + declared. Check that the namespace in which the specialization is + occurring is permissible. Returns false iff it is invalid to + specialize TMPL in the current namespace. */ + +static bool +check_specialization_namespace (tree tmpl) +{ + tree tpl_ns = decl_namespace_context (tmpl); + + /* [tmpl.expl.spec] + + An explicit specialization shall be declared in the namespace of + which the template is a member, or, for member templates, in the + namespace of which the enclosing class or enclosing class + template is a member. An explicit specialization of a member + function, member class or static data member of a class template + shall be declared in the namespace of which the class template is + a member. */ + if (current_scope() != DECL_CONTEXT (tmpl) + && !at_namespace_scope_p ()) + { + error ("specialization of %qD must appear at namespace scope", tmpl); + return false; + } + if (is_associated_namespace (current_namespace, tpl_ns)) + /* Same or super-using namespace. */ + return true; + else + { + permerror (input_location, "specialization of %qD in different namespace", tmpl); + permerror (input_location, " from definition of %q+#D", tmpl); + return false; + } +} + +/* SPEC is an explicit instantiation. Check that it is valid to + perform this explicit instantiation in the current namespace. */ + +static void +check_explicit_instantiation_namespace (tree spec) +{ + tree ns; + + /* DR 275: An explicit instantiation shall appear in an enclosing + namespace of its template. */ + ns = decl_namespace_context (spec); + if (!is_ancestor (current_namespace, ns)) + permerror (input_location, "explicit instantiation of %qD in namespace %qD " + "(which does not enclose namespace %qD)", + spec, current_namespace, ns); +} + +/* The TYPE is being declared. If it is a template type, that means it + is a partial specialization. Do appropriate error-checking. */ + +tree +maybe_process_partial_specialization (tree type) +{ + tree context; + + if (type == error_mark_node) + return error_mark_node; + + /* A lambda that appears in specialization context is not itself a + specialization. */ + if (CLASS_TYPE_P (type) && CLASSTYPE_LAMBDA_EXPR (type)) + return type; + + if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM) + { + error ("name of class shadows template template parameter %qD", + TYPE_NAME (type)); + return error_mark_node; + } + + context = TYPE_CONTEXT (type); + + if (TYPE_ALIAS_P (type)) + { + if (TYPE_TEMPLATE_INFO (type) + && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type))) + error ("specialization of alias template %qD", + TYPE_TI_TEMPLATE (type)); + else + error ("explicit specialization of non-template %qT", type); + return error_mark_node; + } + else if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type)) + { + /* This is for ordinary explicit specialization and partial + specialization of a template class such as: + + template <> class C<int>; + + or: + + template <class T> class C<T*>; + + Make sure that `C<int>' and `C<T*>' are implicit instantiations. */ + + if (CLASSTYPE_IMPLICIT_INSTANTIATION (type) + && !COMPLETE_TYPE_P (type)) + { + if (!check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type)) + && !at_namespace_scope_p ()) + return error_mark_node; + SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type); + DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)) = input_location; + if (processing_template_decl) + { + if (push_template_decl (TYPE_MAIN_DECL (type)) + == error_mark_node) + return error_mark_node; + } + } + else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type)) + error ("specialization of %qT after instantiation", type); + else if (errorcount && !processing_specialization + && CLASSTYPE_TEMPLATE_SPECIALIZATION (type) + && !uses_template_parms (CLASSTYPE_TI_ARGS (type))) + /* Trying to define a specialization either without a template<> header + or in an inappropriate place. We've already given an error, so just + bail now so we don't actually define the specialization. */ + return error_mark_node; + } + else if (CLASS_TYPE_P (type) + && !CLASSTYPE_USE_TEMPLATE (type) + && CLASSTYPE_TEMPLATE_INFO (type) + && context && CLASS_TYPE_P (context) + && CLASSTYPE_TEMPLATE_INFO (context)) + { + /* This is for an explicit specialization of member class + template according to [temp.expl.spec/18]: + + template <> template <class U> class C<int>::D; + + The context `C<int>' must be an implicit instantiation. + Otherwise this is just a member class template declared + earlier like: + + template <> class C<int> { template <class U> class D; }; + template <> template <class U> class C<int>::D; + + In the first case, `C<int>::D' is a specialization of `C<T>::D' + while in the second case, `C<int>::D' is a primary template + and `C<T>::D' may not exist. */ + + if (CLASSTYPE_IMPLICIT_INSTANTIATION (context) + && !COMPLETE_TYPE_P (type)) + { + tree t; + tree tmpl = CLASSTYPE_TI_TEMPLATE (type); + + if (current_namespace + != decl_namespace_context (tmpl)) + { + permerror (input_location, "specializing %q#T in different namespace", type); + permerror (input_location, " from definition of %q+#D", tmpl); + } + + /* Check for invalid specialization after instantiation: + + template <> template <> class C<int>::D<int>; + template <> template <class U> class C<int>::D; */ + + for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl); + t; t = TREE_CHAIN (t)) + { + tree inst = TREE_VALUE (t); + if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst) + || !COMPLETE_OR_OPEN_TYPE_P (inst)) + { + /* We already have a full specialization of this partial + instantiation, or a full specialization has been + looked up but not instantiated. Reassign it to the + new member specialization template. */ + spec_entry elt; + spec_entry *entry; + void **slot; + + elt.tmpl = most_general_template (tmpl); + elt.args = CLASSTYPE_TI_ARGS (inst); + elt.spec = inst; + + htab_remove_elt (type_specializations, &elt); + + elt.tmpl = tmpl; + elt.args = INNERMOST_TEMPLATE_ARGS (elt.args); + + slot = htab_find_slot (type_specializations, &elt, INSERT); + entry = ggc_alloc_spec_entry (); + *entry = elt; + *slot = entry; + } + else + /* But if we've had an implicit instantiation, that's a + problem ([temp.expl.spec]/6). */ + error ("specialization %qT after instantiation %qT", + type, inst); + } + + /* Mark TYPE as a specialization. And as a result, we only + have one level of template argument for the innermost + class template. */ + SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type); + DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)) = input_location; + CLASSTYPE_TI_ARGS (type) + = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)); + } + } + else if (processing_specialization) + { + /* Someday C++0x may allow for enum template specialization. */ + if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE + && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context)) + pedwarn (input_location, OPT_Wpedantic, "template specialization " + "of %qD not allowed by ISO C++", type); + else + { + error ("explicit specialization of non-template %qT", type); + return error_mark_node; + } + } + + return type; +} + +/* Returns nonzero if we can optimize the retrieval of specializations + for TMPL, a TEMPLATE_DECL. In particular, for such a template, we + do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */ + +static inline bool +optimize_specialization_lookup_p (tree tmpl) +{ + return (DECL_FUNCTION_TEMPLATE_P (tmpl) + && DECL_CLASS_SCOPE_P (tmpl) + /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template + parameter. */ + && CLASS_TYPE_P (DECL_CONTEXT (tmpl)) + /* The optimized lookup depends on the fact that the + template arguments for the member function template apply + purely to the containing class, which is not true if the + containing class is an explicit or partial + specialization. */ + && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl)) + && !DECL_MEMBER_TEMPLATE_P (tmpl) + && !DECL_CONV_FN_P (tmpl) + /* It is possible to have a template that is not a member + template and is not a member of a template class: + + template <typename T> + struct S { friend A::f(); }; + + Here, the friend function is a template, but the context does + not have template information. The optimized lookup relies + on having ARGS be the template arguments for both the class + and the function template. */ + && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl))); +} + +/* Retrieve the specialization (in the sense of [temp.spec] - a + specialization is either an instantiation or an explicit + specialization) of TMPL for the given template ARGS. If there is + no such specialization, return NULL_TREE. The ARGS are a vector of + arguments, or a vector of vectors of arguments, in the case of + templates with more than one level of parameters. + + If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true, + then we search for a partial specialization matching ARGS. This + parameter is ignored if TMPL is not a class template. + + We can also look up a FIELD_DECL, if it is a lambda capture pack; the + result is a NONTYPE_ARGUMENT_PACK. */ + +static tree +retrieve_specialization (tree tmpl, tree args, hashval_t hash) +{ + if (tmpl == NULL_TREE) + return NULL_TREE; + + if (args == error_mark_node) + return NULL_TREE; + + gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL + || TREE_CODE (tmpl) == FIELD_DECL); + + /* There should be as many levels of arguments as there are + levels of parameters. */ + gcc_assert (TMPL_ARGS_DEPTH (args) + == (TREE_CODE (tmpl) == TEMPLATE_DECL + ? TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)) + : template_class_depth (DECL_CONTEXT (tmpl)))); + + if (optimize_specialization_lookup_p (tmpl)) + { + tree class_template; + tree class_specialization; + vec<tree, va_gc> *methods; + tree fns; + int idx; + + /* The template arguments actually apply to the containing + class. Find the class specialization with those + arguments. */ + class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl)); + class_specialization + = retrieve_specialization (class_template, args, 0); + if (!class_specialization) + return NULL_TREE; + /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC + for the specialization. */ + idx = class_method_index_for_fn (class_specialization, tmpl); + if (idx == -1) + return NULL_TREE; + /* Iterate through the methods with the indicated name, looking + for the one that has an instance of TMPL. */ + methods = CLASSTYPE_METHOD_VEC (class_specialization); + for (fns = (*methods)[idx]; fns; fns = OVL_NEXT (fns)) + { + tree fn = OVL_CURRENT (fns); + if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl + /* using-declarations can add base methods to the method vec, + and we don't want those here. */ + && DECL_CONTEXT (fn) == class_specialization) + return fn; + } + return NULL_TREE; + } + else + { + spec_entry *found; + spec_entry elt; + htab_t specializations; + + elt.tmpl = tmpl; + elt.args = args; + elt.spec = NULL_TREE; + + if (DECL_CLASS_TEMPLATE_P (tmpl)) + specializations = type_specializations; + else + specializations = decl_specializations; + + if (hash == 0) + hash = hash_specialization (&elt); + found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash); + if (found) + return found->spec; + } + + return NULL_TREE; +} + +/* Like retrieve_specialization, but for local declarations. */ + +static tree +retrieve_local_specialization (tree tmpl) +{ + void **slot; + + if (local_specializations == NULL) + return NULL_TREE; + + slot = pointer_map_contains (local_specializations, tmpl); + return slot ? (tree) *slot : NULL_TREE; +} + +/* Returns nonzero iff DECL is a specialization of TMPL. */ + +int +is_specialization_of (tree decl, tree tmpl) +{ + tree t; + + if (TREE_CODE (decl) == FUNCTION_DECL) + { + for (t = decl; + t != NULL_TREE; + t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE) + if (t == tmpl) + return 1; + } + else + { + gcc_assert (TREE_CODE (decl) == TYPE_DECL); + + for (t = TREE_TYPE (decl); + t != NULL_TREE; + t = CLASSTYPE_USE_TEMPLATE (t) + ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE) + if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl))) + return 1; + } + + return 0; +} + +/* Returns nonzero iff DECL is a specialization of friend declaration + FRIEND_DECL according to [temp.friend]. */ + +bool +is_specialization_of_friend (tree decl, tree friend_decl) +{ + bool need_template = true; + int template_depth; + + gcc_assert (TREE_CODE (decl) == FUNCTION_DECL + || TREE_CODE (decl) == TYPE_DECL); + + /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function + of a template class, we want to check if DECL is a specialization + if this. */ + if (TREE_CODE (friend_decl) == FUNCTION_DECL + && DECL_TEMPLATE_INFO (friend_decl) + && !DECL_USE_TEMPLATE (friend_decl)) + { + /* We want a TEMPLATE_DECL for `is_specialization_of'. */ + friend_decl = DECL_TI_TEMPLATE (friend_decl); + need_template = false; + } + else if (TREE_CODE (friend_decl) == TEMPLATE_DECL + && !PRIMARY_TEMPLATE_P (friend_decl)) + need_template = false; + + /* There is nothing to do if this is not a template friend. */ + if (TREE_CODE (friend_decl) != TEMPLATE_DECL) + return false; + + if (is_specialization_of (decl, friend_decl)) + return true; + + /* [temp.friend/6] + A member of a class template may be declared to be a friend of a + non-template class. In this case, the corresponding member of + every specialization of the class template is a friend of the + class granting friendship. + + For example, given a template friend declaration + + template <class T> friend void A<T>::f(); + + the member function below is considered a friend + + template <> struct A<int> { + void f(); + }; + + For this type of template friend, TEMPLATE_DEPTH below will be + nonzero. To determine if DECL is a friend of FRIEND, we first + check if the enclosing class is a specialization of another. */ + + template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl)); + if (template_depth + && DECL_CLASS_SCOPE_P (decl) + && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)), + CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl)))) + { + /* Next, we check the members themselves. In order to handle + a few tricky cases, such as when FRIEND_DECL's are + + template <class T> friend void A<T>::g(T t); + template <class T> template <T t> friend void A<T>::h(); + + and DECL's are + + void A<int>::g(int); + template <int> void A<int>::h(); + + we need to figure out ARGS, the template arguments from + the context of DECL. This is required for template substitution + of `T' in the function parameter of `g' and template parameter + of `h' in the above examples. Here ARGS corresponds to `int'. */ + + tree context = DECL_CONTEXT (decl); + tree args = NULL_TREE; + int current_depth = 0; + + while (current_depth < template_depth) + { + if (CLASSTYPE_TEMPLATE_INFO (context)) + { + if (current_depth == 0) + args = TYPE_TI_ARGS (context); + else + args = add_to_template_args (TYPE_TI_ARGS (context), args); + current_depth++; + } + context = TYPE_CONTEXT (context); + } + + if (TREE_CODE (decl) == FUNCTION_DECL) + { + bool is_template; + tree friend_type; + tree decl_type; + tree friend_args_type; + tree decl_args_type; + + /* Make sure that both DECL and FRIEND_DECL are templates or + non-templates. */ + is_template = DECL_TEMPLATE_INFO (decl) + && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)); + if (need_template ^ is_template) + return false; + else if (is_template) + { + /* If both are templates, check template parameter list. */ + tree friend_parms + = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl), + args, tf_none); + if (!comp_template_parms + (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)), + friend_parms)) + return false; + + decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl)); + } + else + decl_type = TREE_TYPE (decl); + + friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args, + tf_none, NULL_TREE); + if (friend_type == error_mark_node) + return false; + + /* Check if return types match. */ + if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type))) + return false; + + /* Check if function parameter types match, ignoring the + `this' parameter. */ + friend_args_type = TYPE_ARG_TYPES (friend_type); + decl_args_type = TYPE_ARG_TYPES (decl_type); + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl)) + friend_args_type = TREE_CHAIN (friend_args_type); + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)) + decl_args_type = TREE_CHAIN (decl_args_type); + + return compparms (decl_args_type, friend_args_type); + } + else + { + /* DECL is a TYPE_DECL */ + bool is_template; + tree decl_type = TREE_TYPE (decl); + + /* Make sure that both DECL and FRIEND_DECL are templates or + non-templates. */ + is_template + = CLASSTYPE_TEMPLATE_INFO (decl_type) + && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type)); + + if (need_template ^ is_template) + return false; + else if (is_template) + { + tree friend_parms; + /* If both are templates, check the name of the two + TEMPLATE_DECL's first because is_friend didn't. */ + if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type)) + != DECL_NAME (friend_decl)) + return false; + + /* Now check template parameter list. */ + friend_parms + = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl), + args, tf_none); + return comp_template_parms + (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)), + friend_parms); + } + else + return (DECL_NAME (decl) + == DECL_NAME (friend_decl)); + } + } + return false; +} + +/* Register the specialization SPEC as a specialization of TMPL with + the indicated ARGS. IS_FRIEND indicates whether the specialization + is actually just a friend declaration. Returns SPEC, or an + equivalent prior declaration, if available. + + We also store instantiations of field packs in the hash table, even + though they are not themselves templates, to make lookup easier. */ + +static tree +register_specialization (tree spec, tree tmpl, tree args, bool is_friend, + hashval_t hash) +{ + tree fn; + void **slot = NULL; + spec_entry elt; + + gcc_assert ((TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec)) + || (TREE_CODE (tmpl) == FIELD_DECL + && TREE_CODE (spec) == NONTYPE_ARGUMENT_PACK)); + + if (TREE_CODE (spec) == FUNCTION_DECL + && uses_template_parms (DECL_TI_ARGS (spec))) + /* This is the FUNCTION_DECL for a partial instantiation. Don't + register it; we want the corresponding TEMPLATE_DECL instead. + We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than + the more obvious `uses_template_parms (spec)' to avoid problems + with default function arguments. In particular, given + something like this: + + template <class T> void f(T t1, T t = T()) + + the default argument expression is not substituted for in an + instantiation unless and until it is actually needed. */ + return spec; + + if (optimize_specialization_lookup_p (tmpl)) + /* We don't put these specializations in the hash table, but we might + want to give an error about a mismatch. */ + fn = retrieve_specialization (tmpl, args, 0); + else + { + elt.tmpl = tmpl; + elt.args = args; + elt.spec = spec; + + if (hash == 0) + hash = hash_specialization (&elt); + + slot = + htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT); + if (*slot) + fn = ((spec_entry *) *slot)->spec; + else + fn = NULL_TREE; + } + + /* We can sometimes try to re-register a specialization that we've + already got. In particular, regenerate_decl_from_template calls + duplicate_decls which will update the specialization list. But, + we'll still get called again here anyhow. It's more convenient + to simply allow this than to try to prevent it. */ + if (fn == spec) + return spec; + else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec)) + { + if (DECL_TEMPLATE_INSTANTIATION (fn)) + { + if (DECL_ODR_USED (fn) + || DECL_EXPLICIT_INSTANTIATION (fn)) + { + error ("specialization of %qD after instantiation", + fn); + return error_mark_node; + } + else + { + tree clone; + /* This situation should occur only if the first + specialization is an implicit instantiation, the + second is an explicit specialization, and the + implicit instantiation has not yet been used. That + situation can occur if we have implicitly + instantiated a member function and then specialized + it later. + + We can also wind up here if a friend declaration that + looked like an instantiation turns out to be a + specialization: + + template <class T> void foo(T); + class S { friend void foo<>(int) }; + template <> void foo(int); + + We transform the existing DECL in place so that any + pointers to it become pointers to the updated + declaration. + + If there was a definition for the template, but not + for the specialization, we want this to look as if + there were no definition, and vice versa. */ + DECL_INITIAL (fn) = NULL_TREE; + duplicate_decls (spec, fn, is_friend); + /* The call to duplicate_decls will have applied + [temp.expl.spec]: + + An explicit specialization of a function template + is inline only if it is explicitly declared to be, + and independently of whether its function template + is. + + to the primary function; now copy the inline bits to + the various clones. */ + FOR_EACH_CLONE (clone, fn) + { + DECL_DECLARED_INLINE_P (clone) + = DECL_DECLARED_INLINE_P (fn); + DECL_SOURCE_LOCATION (clone) + = DECL_SOURCE_LOCATION (fn); + DECL_DELETED_FN (clone) + = DECL_DELETED_FN (fn); + } + check_specialization_namespace (tmpl); + + return fn; + } + } + else if (DECL_TEMPLATE_SPECIALIZATION (fn)) + { + if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec)) + /* Dup decl failed, but this is a new definition. Set the + line number so any errors match this new + definition. */ + DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec); + + return fn; + } + } + else if (fn) + return duplicate_decls (spec, fn, is_friend); + + /* A specialization must be declared in the same namespace as the + template it is specializing. */ + if (DECL_P (spec) && DECL_TEMPLATE_SPECIALIZATION (spec) + && !check_specialization_namespace (tmpl)) + DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl); + + if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */) + { + spec_entry *entry = ggc_alloc_spec_entry (); + gcc_assert (tmpl && args && spec); + *entry = elt; + *slot = entry; + if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec) + && PRIMARY_TEMPLATE_P (tmpl) + && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE) + /* TMPL is a forward declaration of a template function; keep a list + of all specializations in case we need to reassign them to a friend + template later in tsubst_friend_function. */ + DECL_TEMPLATE_INSTANTIATIONS (tmpl) + = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl)); + } + + return spec; +} + +/* Returns true iff two spec_entry nodes are equivalent. Only compares the + TMPL and ARGS members, ignores SPEC. */ + +int comparing_specializations; + +static int +eq_specializations (const void *p1, const void *p2) +{ + const spec_entry *e1 = (const spec_entry *)p1; + const spec_entry *e2 = (const spec_entry *)p2; + int equal; + + ++comparing_specializations; + equal = (e1->tmpl == e2->tmpl + && comp_template_args (e1->args, e2->args)); + --comparing_specializations; + + return equal; +} + +/* Returns a hash for a template TMPL and template arguments ARGS. */ + +static hashval_t +hash_tmpl_and_args (tree tmpl, tree args) +{ + hashval_t val = DECL_UID (tmpl); + return iterative_hash_template_arg (args, val); +} + +/* Returns a hash for a spec_entry node based on the TMPL and ARGS members, + ignoring SPEC. */ + +static hashval_t +hash_specialization (const void *p) +{ + const spec_entry *e = (const spec_entry *)p; + return hash_tmpl_and_args (e->tmpl, e->args); +} + +/* Recursively calculate a hash value for a template argument ARG, for use + in the hash tables of template specializations. */ + +hashval_t +iterative_hash_template_arg (tree arg, hashval_t val) +{ + unsigned HOST_WIDE_INT i; + enum tree_code code; + char tclass; + + if (arg == NULL_TREE) + return iterative_hash_object (arg, val); + + if (!TYPE_P (arg)) + STRIP_NOPS (arg); + + if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT) + /* We can get one of these when re-hashing a previous entry in the middle + of substituting into a pack expansion. Just look through it. */ + arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg); + + code = TREE_CODE (arg); + tclass = TREE_CODE_CLASS (code); + + val = iterative_hash_object (code, val); + + switch (code) + { + case ERROR_MARK: + return val; + + case IDENTIFIER_NODE: + return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val); + + case TREE_VEC: + { + int i, len = TREE_VEC_LENGTH (arg); + for (i = 0; i < len; ++i) + val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val); + return val; + } + + case TYPE_PACK_EXPANSION: + case EXPR_PACK_EXPANSION: + val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val); + return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val); + + case TYPE_ARGUMENT_PACK: + case NONTYPE_ARGUMENT_PACK: + return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val); + + case TREE_LIST: + for (; arg; arg = TREE_CHAIN (arg)) + val = iterative_hash_template_arg (TREE_VALUE (arg), val); + return val; + + case OVERLOAD: + for (; arg; arg = OVL_NEXT (arg)) + val = iterative_hash_template_arg (OVL_CURRENT (arg), val); + return val; + + case CONSTRUCTOR: + { + tree field, value; + FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value) + { + val = iterative_hash_template_arg (field, val); + val = iterative_hash_template_arg (value, val); + } + return val; + } + + case PARM_DECL: + if (!DECL_ARTIFICIAL (arg)) + { + val = iterative_hash_object (DECL_PARM_INDEX (arg), val); + val = iterative_hash_object (DECL_PARM_LEVEL (arg), val); + } + return iterative_hash_template_arg (TREE_TYPE (arg), val); + + case TARGET_EXPR: + return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val); + + case PTRMEM_CST: + val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val); + return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val); + + case TEMPLATE_PARM_INDEX: + val = iterative_hash_template_arg + (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val); + val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val); + return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val); + + case TRAIT_EXPR: + val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val); + val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val); + return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val); + + case BASELINK: + val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)), + val); + return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)), + val); + + case MODOP_EXPR: + val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val); + code = TREE_CODE (TREE_OPERAND (arg, 1)); + val = iterative_hash_object (code, val); + return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val); + + case LAMBDA_EXPR: + /* A lambda can't appear in a template arg, but don't crash on + erroneous input. */ + gcc_assert (seen_error ()); + return val; + + case CAST_EXPR: + case IMPLICIT_CONV_EXPR: + case STATIC_CAST_EXPR: + case REINTERPRET_CAST_EXPR: + case CONST_CAST_EXPR: + case DYNAMIC_CAST_EXPR: + case NEW_EXPR: + val = iterative_hash_template_arg (TREE_TYPE (arg), val); + /* Now hash operands as usual. */ + break; + + default: + break; + } + + switch (tclass) + { + case tcc_type: + if (TYPE_CANONICAL (arg)) + return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)), + val); + else if (TREE_CODE (arg) == DECLTYPE_TYPE) + return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val); + /* Otherwise just compare the types during lookup. */ + return val; + + case tcc_declaration: + case tcc_constant: + return iterative_hash_expr (arg, val); + + default: + gcc_assert (IS_EXPR_CODE_CLASS (tclass)); + { + unsigned n = cp_tree_operand_length (arg); + for (i = 0; i < n; ++i) + val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val); + return val; + } + } + gcc_unreachable (); + return 0; +} + +/* Unregister the specialization SPEC as a specialization of TMPL. + Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true + if the SPEC was listed as a specialization of TMPL. + + Note that SPEC has been ggc_freed, so we can't look inside it. */ + +bool +reregister_specialization (tree spec, tree tinfo, tree new_spec) +{ + spec_entry *entry; + spec_entry elt; + + elt.tmpl = most_general_template (TI_TEMPLATE (tinfo)); + elt.args = TI_ARGS (tinfo); + elt.spec = NULL_TREE; + + entry = (spec_entry *) htab_find (decl_specializations, &elt); + if (entry != NULL) + { + gcc_assert (entry->spec == spec || entry->spec == new_spec); + gcc_assert (new_spec != NULL_TREE); + entry->spec = new_spec; + return 1; + } + + return 0; +} + +/* Like register_specialization, but for local declarations. We are + registering SPEC, an instantiation of TMPL. */ + +static void +register_local_specialization (tree spec, tree tmpl) +{ + void **slot; + + slot = pointer_map_insert (local_specializations, tmpl); + *slot = spec; +} + +/* TYPE is a class type. Returns true if TYPE is an explicitly + specialized class. */ + +bool +explicit_class_specialization_p (tree type) +{ + if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type)) + return false; + return !uses_template_parms (CLASSTYPE_TI_ARGS (type)); +} + +/* Print the list of functions at FNS, going through all the overloads + for each element of the list. Alternatively, FNS can not be a + TREE_LIST, in which case it will be printed together with all the + overloads. + + MORE and *STR should respectively be FALSE and NULL when the function + is called from the outside. They are used internally on recursive + calls. print_candidates manages the two parameters and leaves NULL + in *STR when it ends. */ + +static void +print_candidates_1 (tree fns, bool more, const char **str) +{ + tree fn, fn2; + char *spaces = NULL; + + for (fn = fns; fn; fn = OVL_NEXT (fn)) + if (TREE_CODE (fn) == TREE_LIST) + { + for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2)) + print_candidates_1 (TREE_VALUE (fn2), + TREE_CHAIN (fn2) || more, str); + } + else + { + tree cand = OVL_CURRENT (fn); + if (!*str) + { + /* Pick the prefix string. */ + if (!more && !OVL_NEXT (fns)) + { + inform (DECL_SOURCE_LOCATION (cand), + "candidate is: %#D", cand); + continue; + } + + *str = _("candidates are:"); + spaces = get_spaces (*str); + } + inform (DECL_SOURCE_LOCATION (cand), "%s %#D", *str, cand); + *str = spaces ? spaces : *str; + } + + if (!more) + { + free (spaces); + *str = NULL; + } +} + +/* Print the list of candidate FNS in an error message. FNS can also + be a TREE_LIST of non-functions in the case of an ambiguous lookup. */ + +void +print_candidates (tree fns) +{ + const char *str = NULL; + print_candidates_1 (fns, false, &str); + gcc_assert (str == NULL); +} + +/* Returns the template (one of the functions given by TEMPLATE_ID) + which can be specialized to match the indicated DECL with the + explicit template args given in TEMPLATE_ID. The DECL may be + NULL_TREE if none is available. In that case, the functions in + TEMPLATE_ID are non-members. + + If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a + specialization of a member template. + + The TEMPLATE_COUNT is the number of references to qualifying + template classes that appeared in the name of the function. See + check_explicit_specialization for a more accurate description. + + TSK indicates what kind of template declaration (if any) is being + declared. TSK_TEMPLATE indicates that the declaration given by + DECL, though a FUNCTION_DECL, has template parameters, and is + therefore a template function. + + The template args (those explicitly specified and those deduced) + are output in a newly created vector *TARGS_OUT. + + If it is impossible to determine the result, an error message is + issued. The error_mark_node is returned to indicate failure. */ + +static tree +determine_specialization (tree template_id, + tree decl, + tree* targs_out, + int need_member_template, + int template_count, + tmpl_spec_kind tsk) +{ + tree fns; + tree targs; + tree explicit_targs; + tree candidates = NULL_TREE; + /* A TREE_LIST of templates of which DECL may be a specialization. + The TREE_VALUE of each node is a TEMPLATE_DECL. The + corresponding TREE_PURPOSE is the set of template arguments that, + when used to instantiate the template, would produce a function + with the signature of DECL. */ + tree templates = NULL_TREE; + int header_count; + cp_binding_level *b; + + *targs_out = NULL_TREE; + + if (template_id == error_mark_node || decl == error_mark_node) + return error_mark_node; + + /* We shouldn't be specializing a member template of an + unspecialized class template; we already gave an error in + check_specialization_scope, now avoid crashing. */ + if (template_count && DECL_CLASS_SCOPE_P (decl) + && template_class_depth (DECL_CONTEXT (decl)) > 0) + { + gcc_assert (errorcount); + return error_mark_node; + } + + fns = TREE_OPERAND (template_id, 0); + explicit_targs = TREE_OPERAND (template_id, 1); + + if (fns == error_mark_node) + return error_mark_node; + + /* Check for baselinks. */ + if (BASELINK_P (fns)) + fns = BASELINK_FUNCTIONS (fns); + + if (!is_overloaded_fn (fns)) + { + error ("%qD is not a function template", fns); + return error_mark_node; + } + + /* Count the number of template headers specified for this + specialization. */ + header_count = 0; + for (b = current_binding_level; + b->kind == sk_template_parms; + b = b->level_chain) + ++header_count; + + for (; fns; fns = OVL_NEXT (fns)) + { + tree fn = OVL_CURRENT (fns); + + if (TREE_CODE (fn) == TEMPLATE_DECL) + { + tree decl_arg_types; + tree fn_arg_types; + tree insttype; + + /* In case of explicit specialization, we need to check if + the number of template headers appearing in the specialization + is correct. This is usually done in check_explicit_specialization, + but the check done there cannot be exhaustive when specializing + member functions. Consider the following code: + + template <> void A<int>::f(int); + template <> template <> void A<int>::f(int); + + Assuming that A<int> is not itself an explicit specialization + already, the first line specializes "f" which is a non-template + member function, whilst the second line specializes "f" which + is a template member function. So both lines are syntactically + correct, and check_explicit_specialization does not reject + them. + + Here, we can do better, as we are matching the specialization + against the declarations. We count the number of template + headers, and we check if they match TEMPLATE_COUNT + 1 + (TEMPLATE_COUNT is the number of qualifying template classes, + plus there must be another header for the member template + itself). + + Notice that if header_count is zero, this is not a + specialization but rather a template instantiation, so there + is no check we can perform here. */ + if (header_count && header_count != template_count + 1) + continue; + + /* Check that the number of template arguments at the + innermost level for DECL is the same as for FN. */ + if (current_binding_level->kind == sk_template_parms + && !current_binding_level->explicit_spec_p + && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn)) + != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS + (current_template_parms)))) + continue; + + /* DECL might be a specialization of FN. */ + decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl)); + fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn)); + + /* For a non-static member function, we need to make sure + that the const qualification is the same. Since + get_bindings does not try to merge the "this" parameter, + we must do the comparison explicitly. */ + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) + && !same_type_p (TREE_VALUE (fn_arg_types), + TREE_VALUE (decl_arg_types))) + continue; + + /* Skip the "this" parameter and, for constructors of + classes with virtual bases, the VTT parameter. A + full specialization of a constructor will have a VTT + parameter, but a template never will. */ + decl_arg_types + = skip_artificial_parms_for (decl, decl_arg_types); + fn_arg_types + = skip_artificial_parms_for (fn, fn_arg_types); + + /* Function templates cannot be specializations; there are + no partial specializations of functions. Therefore, if + the type of DECL does not match FN, there is no + match. */ + if (tsk == tsk_template) + { + if (compparms (fn_arg_types, decl_arg_types)) + candidates = tree_cons (NULL_TREE, fn, candidates); + continue; + } + + /* See whether this function might be a specialization of this + template. Suppress access control because we might be trying + to make this specialization a friend, and we have already done + access control for the declaration of the specialization. */ + push_deferring_access_checks (dk_no_check); + targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true); + pop_deferring_access_checks (); + + if (!targs) + /* We cannot deduce template arguments that when used to + specialize TMPL will produce DECL. */ + continue; + + /* Make sure that the deduced arguments actually work. */ + insttype = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE); + if (insttype == error_mark_node) + continue; + fn_arg_types + = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (insttype)); + if (!compparms (fn_arg_types, decl_arg_types)) + continue; + + /* Save this template, and the arguments deduced. */ + templates = tree_cons (targs, fn, templates); + } + else if (need_member_template) + /* FN is an ordinary member function, and we need a + specialization of a member template. */ + ; + else if (TREE_CODE (fn) != FUNCTION_DECL) + /* We can get IDENTIFIER_NODEs here in certain erroneous + cases. */ + ; + else if (!DECL_FUNCTION_MEMBER_P (fn)) + /* This is just an ordinary non-member function. Nothing can + be a specialization of that. */ + ; + else if (DECL_ARTIFICIAL (fn)) + /* Cannot specialize functions that are created implicitly. */ + ; + else + { + tree decl_arg_types; + + /* This is an ordinary member function. However, since + we're here, we can assume its enclosing class is a + template class. For example, + + template <typename T> struct S { void f(); }; + template <> void S<int>::f() {} + + Here, S<int>::f is a non-template, but S<int> is a + template class. If FN has the same type as DECL, we + might be in business. */ + + if (!DECL_TEMPLATE_INFO (fn)) + /* Its enclosing class is an explicit specialization + of a template class. This is not a candidate. */ + continue; + + if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)), + TREE_TYPE (TREE_TYPE (fn)))) + /* The return types differ. */ + continue; + + /* Adjust the type of DECL in case FN is a static member. */ + decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl)); + if (DECL_STATIC_FUNCTION_P (fn) + && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)) + decl_arg_types = TREE_CHAIN (decl_arg_types); + + if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)), + decl_arg_types)) + /* They match! */ + candidates = tree_cons (NULL_TREE, fn, candidates); + } + } + + if (templates && TREE_CHAIN (templates)) + { + /* We have: + + [temp.expl.spec] + + It is possible for a specialization with a given function + signature to be instantiated from more than one function + template. In such cases, explicit specification of the + template arguments must be used to uniquely identify the + function template specialization being specialized. + + Note that here, there's no suggestion that we're supposed to + determine which of the candidate templates is most + specialized. However, we, also have: + + [temp.func.order] + + Partial ordering of overloaded function template + declarations is used in the following contexts to select + the function template to which a function template + specialization refers: + + -- when an explicit specialization refers to a function + template. + + So, we do use the partial ordering rules, at least for now. + This extension can only serve to make invalid programs valid, + so it's safe. And, there is strong anecdotal evidence that + the committee intended the partial ordering rules to apply; + the EDG front end has that behavior, and John Spicer claims + that the committee simply forgot to delete the wording in + [temp.expl.spec]. */ + tree tmpl = most_specialized_instantiation (templates); + if (tmpl != error_mark_node) + { + templates = tmpl; + TREE_CHAIN (templates) = NULL_TREE; + } + } + + if (templates == NULL_TREE && candidates == NULL_TREE) + { + error ("template-id %qD for %q+D does not match any template " + "declaration", template_id, decl); + if (header_count && header_count != template_count + 1) + inform (input_location, "saw %d %<template<>%>, need %d for " + "specializing a member function template", + header_count, template_count + 1); + return error_mark_node; + } + else if ((templates && TREE_CHAIN (templates)) + || (candidates && TREE_CHAIN (candidates)) + || (templates && candidates)) + { + error ("ambiguous template specialization %qD for %q+D", + template_id, decl); + candidates = chainon (candidates, templates); + print_candidates (candidates); + return error_mark_node; + } + + /* We have one, and exactly one, match. */ + if (candidates) + { + tree fn = TREE_VALUE (candidates); + *targs_out = copy_node (DECL_TI_ARGS (fn)); + /* DECL is a re-declaration or partial instantiation of a template + function. */ + if (TREE_CODE (fn) == TEMPLATE_DECL) + return fn; + /* It was a specialization of an ordinary member function in a + template class. */ + return DECL_TI_TEMPLATE (fn); + } + + /* It was a specialization of a template. */ + targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates))); + if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs)) + { + *targs_out = copy_node (targs); + SET_TMPL_ARGS_LEVEL (*targs_out, + TMPL_ARGS_DEPTH (*targs_out), + TREE_PURPOSE (templates)); + } + else + *targs_out = TREE_PURPOSE (templates); + return TREE_VALUE (templates); +} + +/* Returns a chain of parameter types, exactly like the SPEC_TYPES, + but with the default argument values filled in from those in the + TMPL_TYPES. */ + +static tree +copy_default_args_to_explicit_spec_1 (tree spec_types, + tree tmpl_types) +{ + tree new_spec_types; + + if (!spec_types) + return NULL_TREE; + + if (spec_types == void_list_node) + return void_list_node; + + /* Substitute into the rest of the list. */ + new_spec_types = + copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types), + TREE_CHAIN (tmpl_types)); + + /* Add the default argument for this parameter. */ + return hash_tree_cons (TREE_PURPOSE (tmpl_types), + TREE_VALUE (spec_types), + new_spec_types); +} + +/* DECL is an explicit specialization. Replicate default arguments + from the template it specializes. (That way, code like: + + template <class T> void f(T = 3); + template <> void f(double); + void g () { f (); } + + works, as required.) An alternative approach would be to look up + the correct default arguments at the call-site, but this approach + is consistent with how implicit instantiations are handled. */ + +static void +copy_default_args_to_explicit_spec (tree decl) +{ + tree tmpl; + tree spec_types; + tree tmpl_types; + tree new_spec_types; + tree old_type; + tree new_type; + tree t; + tree object_type = NULL_TREE; + tree in_charge = NULL_TREE; + tree vtt = NULL_TREE; + + /* See if there's anything we need to do. */ + tmpl = DECL_TI_TEMPLATE (decl); + tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl))); + for (t = tmpl_types; t; t = TREE_CHAIN (t)) + if (TREE_PURPOSE (t)) + break; + if (!t) + return; + + old_type = TREE_TYPE (decl); + spec_types = TYPE_ARG_TYPES (old_type); + + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)) + { + /* Remove the this pointer, but remember the object's type for + CV quals. */ + object_type = TREE_TYPE (TREE_VALUE (spec_types)); + spec_types = TREE_CHAIN (spec_types); + tmpl_types = TREE_CHAIN (tmpl_types); + + if (DECL_HAS_IN_CHARGE_PARM_P (decl)) + { + /* DECL may contain more parameters than TMPL due to the extra + in-charge parameter in constructors and destructors. */ + in_charge = spec_types; + spec_types = TREE_CHAIN (spec_types); + } + if (DECL_HAS_VTT_PARM_P (decl)) + { + vtt = spec_types; + spec_types = TREE_CHAIN (spec_types); + } + } + + /* Compute the merged default arguments. */ + new_spec_types = + copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types); + + /* Compute the new FUNCTION_TYPE. */ + if (object_type) + { + if (vtt) + new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt), + TREE_VALUE (vtt), + new_spec_types); + + if (in_charge) + /* Put the in-charge parameter back. */ + new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge), + TREE_VALUE (in_charge), + new_spec_types); + + new_type = build_method_type_directly (object_type, + TREE_TYPE (old_type), + new_spec_types); + } + else + new_type = build_function_type (TREE_TYPE (old_type), + new_spec_types); + new_type = cp_build_type_attribute_variant (new_type, + TYPE_ATTRIBUTES (old_type)); + new_type = build_exception_variant (new_type, + TYPE_RAISES_EXCEPTIONS (old_type)); + TREE_TYPE (decl) = new_type; +} + +/* Return the number of template headers we expect to see for a definition + or specialization of CTYPE or one of its non-template members. */ + +int +num_template_headers_for_class (tree ctype) +{ + int num_templates = 0; + + while (ctype && CLASS_TYPE_P (ctype)) + { + /* You're supposed to have one `template <...>' for every + template class, but you don't need one for a full + specialization. For example: + + template <class T> struct S{}; + template <> struct S<int> { void f(); }; + void S<int>::f () {} + + is correct; there shouldn't be a `template <>' for the + definition of `S<int>::f'. */ + if (!CLASSTYPE_TEMPLATE_INFO (ctype)) + /* If CTYPE does not have template information of any + kind, then it is not a template, nor is it nested + within a template. */ + break; + if (explicit_class_specialization_p (ctype)) + break; + if (PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (ctype))) + ++num_templates; + + ctype = TYPE_CONTEXT (ctype); + } + + return num_templates; +} + +/* Do a simple sanity check on the template headers that precede the + variable declaration DECL. */ + +void +check_template_variable (tree decl) +{ + tree ctx = CP_DECL_CONTEXT (decl); + int wanted = num_template_headers_for_class (ctx); + if (!TYPE_P (ctx) || !CLASSTYPE_TEMPLATE_INFO (ctx)) + permerror (DECL_SOURCE_LOCATION (decl), + "%qD is not a static data member of a class template", decl); + else if (template_header_count > wanted) + { + pedwarn (DECL_SOURCE_LOCATION (decl), 0, + "too many template headers for %D (should be %d)", + decl, wanted); + if (CLASSTYPE_TEMPLATE_SPECIALIZATION (ctx)) + inform (DECL_SOURCE_LOCATION (decl), + "members of an explicitly specialized class are defined " + "without a template header"); + } +} + +/* Check to see if the function just declared, as indicated in + DECLARATOR, and in DECL, is a specialization of a function + template. We may also discover that the declaration is an explicit + instantiation at this point. + + Returns DECL, or an equivalent declaration that should be used + instead if all goes well. Issues an error message if something is + amiss. Returns error_mark_node if the error is not easily + recoverable. + + FLAGS is a bitmask consisting of the following flags: + + 2: The function has a definition. + 4: The function is a friend. + + The TEMPLATE_COUNT is the number of references to qualifying + template classes that appeared in the name of the function. For + example, in + + template <class T> struct S { void f(); }; + void S<int>::f(); + + the TEMPLATE_COUNT would be 1. However, explicitly specialized + classes are not counted in the TEMPLATE_COUNT, so that in + + template <class T> struct S {}; + template <> struct S<int> { void f(); } + template <> void S<int>::f(); + + the TEMPLATE_COUNT would be 0. (Note that this declaration is + invalid; there should be no template <>.) + + If the function is a specialization, it is marked as such via + DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO + is set up correctly, and it is added to the list of specializations + for that template. */ + +tree +check_explicit_specialization (tree declarator, + tree decl, + int template_count, + int flags) +{ + int have_def = flags & 2; + int is_friend = flags & 4; + int specialization = 0; + int explicit_instantiation = 0; + int member_specialization = 0; + tree ctype = DECL_CLASS_CONTEXT (decl); + tree dname = DECL_NAME (decl); + tmpl_spec_kind tsk; + + if (is_friend) + { + if (!processing_specialization) + tsk = tsk_none; + else + tsk = tsk_excessive_parms; + } + else + tsk = current_tmpl_spec_kind (template_count); + + switch (tsk) + { + case tsk_none: + if (processing_specialization) + { + specialization = 1; + SET_DECL_TEMPLATE_SPECIALIZATION (decl); + } + else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR) + { + if (is_friend) + /* This could be something like: + + template <class T> void f(T); + class S { friend void f<>(int); } */ + specialization = 1; + else + { + /* This case handles bogus declarations like template <> + template <class T> void f<int>(); */ + + error ("template-id %qD in declaration of primary template", + declarator); + return decl; + } + } + break; + + case tsk_invalid_member_spec: + /* The error has already been reported in + check_specialization_scope. */ + return error_mark_node; + + case tsk_invalid_expl_inst: + error ("template parameter list used in explicit instantiation"); + + /* Fall through. */ + + case tsk_expl_inst: + if (have_def) + error ("definition provided for explicit instantiation"); + + explicit_instantiation = 1; + break; + + case tsk_excessive_parms: + case tsk_insufficient_parms: + if (tsk == tsk_excessive_parms) + error ("too many template parameter lists in declaration of %qD", + decl); + else if (template_header_count) + error("too few template parameter lists in declaration of %qD", decl); + else + error("explicit specialization of %qD must be introduced by " + "%<template <>%>", decl); + + /* Fall through. */ + case tsk_expl_spec: + SET_DECL_TEMPLATE_SPECIALIZATION (decl); + if (ctype) + member_specialization = 1; + else + specialization = 1; + break; + + case tsk_template: + if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR) + { + /* This case handles bogus declarations like template <> + template <class T> void f<int>(); */ + + if (uses_template_parms (declarator)) + error ("function template partial specialization %qD " + "is not allowed", declarator); + else + error ("template-id %qD in declaration of primary template", + declarator); + return decl; + } + + if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype)) + /* This is a specialization of a member template, without + specialization the containing class. Something like: + + template <class T> struct S { + template <class U> void f (U); + }; + template <> template <class U> void S<int>::f(U) {} + + That's a specialization -- but of the entire template. */ + specialization = 1; + break; + + default: + gcc_unreachable (); + } + + if (specialization || member_specialization) + { + tree t = TYPE_ARG_TYPES (TREE_TYPE (decl)); + for (; t; t = TREE_CHAIN (t)) + if (TREE_PURPOSE (t)) + { + permerror (input_location, + "default argument specified in explicit specialization"); + break; + } + } + + if (specialization || member_specialization || explicit_instantiation) + { + tree tmpl = NULL_TREE; + tree targs = NULL_TREE; + + /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */ + if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR) + { + tree fns; + + gcc_assert (identifier_p (declarator)); + if (ctype) + fns = dname; + else + { + /* If there is no class context, the explicit instantiation + must be at namespace scope. */ + gcc_assert (DECL_NAMESPACE_SCOPE_P (decl)); + + /* Find the namespace binding, using the declaration + context. */ + fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname, + false, true); + if (fns == error_mark_node || !is_overloaded_fn (fns)) + { + error ("%qD is not a template function", dname); + fns = error_mark_node; + } + else + { + tree fn = OVL_CURRENT (fns); + if (!is_associated_namespace (CP_DECL_CONTEXT (decl), + CP_DECL_CONTEXT (fn))) + error ("%qD is not declared in %qD", + decl, current_namespace); + } + } + + declarator = lookup_template_function (fns, NULL_TREE); + } + + if (declarator == error_mark_node) + return error_mark_node; + + if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype)) + { + if (!explicit_instantiation) + /* A specialization in class scope. This is invalid, + but the error will already have been flagged by + check_specialization_scope. */ + return error_mark_node; + else + { + /* It's not valid to write an explicit instantiation in + class scope, e.g.: + + class C { template void f(); } + + This case is caught by the parser. However, on + something like: + + template class C { void f(); }; + + (which is invalid) we can get here. The error will be + issued later. */ + ; + } + + return decl; + } + else if (ctype != NULL_TREE + && (identifier_p (TREE_OPERAND (declarator, 0)))) + { + /* Find the list of functions in ctype that have the same + name as the declared function. */ + tree name = TREE_OPERAND (declarator, 0); + tree fns = NULL_TREE; + int idx; + + if (constructor_name_p (name, ctype)) + { + int is_constructor = DECL_CONSTRUCTOR_P (decl); + + if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype) + : !CLASSTYPE_DESTRUCTORS (ctype)) + { + /* From [temp.expl.spec]: + + If such an explicit specialization for the member + of a class template names an implicitly-declared + special member function (clause _special_), the + program is ill-formed. + + Similar language is found in [temp.explicit]. */ + error ("specialization of implicitly-declared special member function"); + return error_mark_node; + } + + name = is_constructor ? ctor_identifier : dtor_identifier; + } + + if (!DECL_CONV_FN_P (decl)) + { + idx = lookup_fnfields_1 (ctype, name); + if (idx >= 0) + fns = (*CLASSTYPE_METHOD_VEC (ctype))[idx]; + } + else + { + vec<tree, va_gc> *methods; + tree ovl; + + /* For a type-conversion operator, we cannot do a + name-based lookup. We might be looking for `operator + int' which will be a specialization of `operator T'. + So, we find *all* the conversion operators, and then + select from them. */ + fns = NULL_TREE; + + methods = CLASSTYPE_METHOD_VEC (ctype); + if (methods) + for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT; + methods->iterate (idx, &ovl); + ++idx) + { + if (!DECL_CONV_FN_P (OVL_CURRENT (ovl))) + /* There are no more conversion functions. */ + break; + + /* Glue all these conversion functions together + with those we already have. */ + for (; ovl; ovl = OVL_NEXT (ovl)) + fns = ovl_cons (OVL_CURRENT (ovl), fns); + } + } + + if (fns == NULL_TREE) + { + error ("no member function %qD declared in %qT", name, ctype); + return error_mark_node; + } + else + TREE_OPERAND (declarator, 0) = fns; + } + + /* Figure out what exactly is being specialized at this point. + Note that for an explicit instantiation, even one for a + member function, we cannot tell apriori whether the + instantiation is for a member template, or just a member + function of a template class. Even if a member template is + being instantiated, the member template arguments may be + elided if they can be deduced from the rest of the + declaration. */ + tmpl = determine_specialization (declarator, decl, + &targs, + member_specialization, + template_count, + tsk); + + if (!tmpl || tmpl == error_mark_node) + /* We couldn't figure out what this declaration was + specializing. */ + return error_mark_node; + else + { + tree gen_tmpl = most_general_template (tmpl); + + if (explicit_instantiation) + { + /* We don't set DECL_EXPLICIT_INSTANTIATION here; that + is done by do_decl_instantiation later. */ + + int arg_depth = TMPL_ARGS_DEPTH (targs); + int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)); + + if (arg_depth > parm_depth) + { + /* If TMPL is not the most general template (for + example, if TMPL is a friend template that is + injected into namespace scope), then there will + be too many levels of TARGS. Remove some of them + here. */ + int i; + tree new_targs; + + new_targs = make_tree_vec (parm_depth); + for (i = arg_depth - parm_depth; i < arg_depth; ++i) + TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth)) + = TREE_VEC_ELT (targs, i); + targs = new_targs; + } + + return instantiate_template (tmpl, targs, tf_error); + } + + /* If we thought that the DECL was a member function, but it + turns out to be specializing a static member function, + make DECL a static member function as well. */ + if (DECL_STATIC_FUNCTION_P (tmpl) + && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)) + revert_static_member_fn (decl); + + /* If this is a specialization of a member template of a + template class, we want to return the TEMPLATE_DECL, not + the specialization of it. */ + if (tsk == tsk_template) + { + tree result = DECL_TEMPLATE_RESULT (tmpl); + SET_DECL_TEMPLATE_SPECIALIZATION (tmpl); + DECL_INITIAL (result) = NULL_TREE; + if (have_def) + { + tree parm; + DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl); + DECL_SOURCE_LOCATION (result) + = DECL_SOURCE_LOCATION (decl); + /* We want to use the argument list specified in the + definition, not in the original declaration. */ + DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl); + for (parm = DECL_ARGUMENTS (result); parm; + parm = DECL_CHAIN (parm)) + DECL_CONTEXT (parm) = result; + } + return register_specialization (tmpl, gen_tmpl, targs, + is_friend, 0); + } + + /* Set up the DECL_TEMPLATE_INFO for DECL. */ + DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs); + + /* Inherit default function arguments from the template + DECL is specializing. */ + copy_default_args_to_explicit_spec (decl); + + /* This specialization has the same protection as the + template it specializes. */ + TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl); + TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl); + + /* 7.1.1-1 [dcl.stc] + + A storage-class-specifier shall not be specified in an + explicit specialization... + + The parser rejects these, so unless action is taken here, + explicit function specializations will always appear with + global linkage. + + The action recommended by the C++ CWG in response to C++ + defect report 605 is to make the storage class and linkage + of the explicit specialization match the templated function: + + http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605 + */ + if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl)) + { + tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl); + gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL); + + /* This specialization has the same linkage and visibility as + the function template it specializes. */ + TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func); + if (! TREE_PUBLIC (decl)) + { + DECL_INTERFACE_KNOWN (decl) = 1; + DECL_NOT_REALLY_EXTERN (decl) = 1; + } + DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func); + if (DECL_VISIBILITY_SPECIFIED (tmpl_func)) + { + DECL_VISIBILITY_SPECIFIED (decl) = 1; + DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func); + } + } + + /* If DECL is a friend declaration, declared using an + unqualified name, the namespace associated with DECL may + have been set incorrectly. For example, in: + + template <typename T> void f(T); + namespace N { + struct S { friend void f<int>(int); } + } + + we will have set the DECL_CONTEXT for the friend + declaration to N, rather than to the global namespace. */ + if (DECL_NAMESPACE_SCOPE_P (decl)) + DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl); + + if (is_friend && !have_def) + /* This is not really a declaration of a specialization. + It's just the name of an instantiation. But, it's not + a request for an instantiation, either. */ + SET_DECL_IMPLICIT_INSTANTIATION (decl); + + /* Register this specialization so that we can find it + again. */ + decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0); + + /* A 'structor should already have clones. */ + gcc_assert (decl == error_mark_node + || !(DECL_CONSTRUCTOR_P (decl) + || DECL_DESTRUCTOR_P (decl)) + || DECL_CLONED_FUNCTION_P (DECL_CHAIN (decl))); + } + } + + return decl; +} + +/* Returns 1 iff PARMS1 and PARMS2 are identical sets of template + parameters. These are represented in the same format used for + DECL_TEMPLATE_PARMS. */ + +int +comp_template_parms (const_tree parms1, const_tree parms2) +{ + const_tree p1; + const_tree p2; + + if (parms1 == parms2) + return 1; + + for (p1 = parms1, p2 = parms2; + p1 != NULL_TREE && p2 != NULL_TREE; + p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2)) + { + tree t1 = TREE_VALUE (p1); + tree t2 = TREE_VALUE (p2); + int i; + + gcc_assert (TREE_CODE (t1) == TREE_VEC); + gcc_assert (TREE_CODE (t2) == TREE_VEC); + + if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2)) + return 0; + + for (i = 0; i < TREE_VEC_LENGTH (t2); ++i) + { + tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i)); + tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i)); + + /* If either of the template parameters are invalid, assume + they match for the sake of error recovery. */ + if (parm1 == error_mark_node || parm2 == error_mark_node) + return 1; + + if (TREE_CODE (parm1) != TREE_CODE (parm2)) + return 0; + + if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM + && (TEMPLATE_TYPE_PARAMETER_PACK (parm1) + == TEMPLATE_TYPE_PARAMETER_PACK (parm2))) + continue; + else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2))) + return 0; + } + } + + if ((p1 != NULL_TREE) != (p2 != NULL_TREE)) + /* One set of parameters has more parameters lists than the + other. */ + return 0; + + return 1; +} + +/* Determine whether PARM is a parameter pack. */ + +bool +template_parameter_pack_p (const_tree parm) +{ + /* Determine if we have a non-type template parameter pack. */ + if (TREE_CODE (parm) == PARM_DECL) + return (DECL_TEMPLATE_PARM_P (parm) + && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))); + if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX) + return TEMPLATE_PARM_PARAMETER_PACK (parm); + + /* If this is a list of template parameters, we could get a + TYPE_DECL or a TEMPLATE_DECL. */ + if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL) + parm = TREE_TYPE (parm); + + /* Otherwise it must be a type template parameter. */ + return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM + || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM) + && TEMPLATE_TYPE_PARAMETER_PACK (parm)); +} + +/* Determine if T is a function parameter pack. */ + +bool +function_parameter_pack_p (const_tree t) +{ + if (t && TREE_CODE (t) == PARM_DECL) + return DECL_PACK_P (t); + return false; +} + +/* Return the function template declaration of PRIMARY_FUNC_TMPL_INST. + PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */ + +tree +get_function_template_decl (const_tree primary_func_tmpl_inst) +{ + if (! primary_func_tmpl_inst + || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL + || ! primary_template_instantiation_p (primary_func_tmpl_inst)) + return NULL; + + return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst)); +} + +/* Return true iff the function parameter PARAM_DECL was expanded + from the function parameter pack PACK. */ + +bool +function_parameter_expanded_from_pack_p (tree param_decl, tree pack) +{ + if (DECL_ARTIFICIAL (param_decl) + || !function_parameter_pack_p (pack)) + return false; + + /* The parameter pack and its pack arguments have the same + DECL_PARM_INDEX. */ + return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl); +} + +/* Determine whether ARGS describes a variadic template args list, + i.e., one that is terminated by a template argument pack. */ + +static bool +template_args_variadic_p (tree args) +{ + int nargs; + tree last_parm; + + if (args == NULL_TREE) + return false; + + args = INNERMOST_TEMPLATE_ARGS (args); + nargs = TREE_VEC_LENGTH (args); + + if (nargs == 0) + return false; + + last_parm = TREE_VEC_ELT (args, nargs - 1); + + return ARGUMENT_PACK_P (last_parm); +} + +/* Generate a new name for the parameter pack name NAME (an + IDENTIFIER_NODE) that incorporates its */ + +static tree +make_ith_pack_parameter_name (tree name, int i) +{ + /* Munge the name to include the parameter index. */ +#define NUMBUF_LEN 128 + char numbuf[NUMBUF_LEN]; + char* newname; + int newname_len; + + if (name == NULL_TREE) + return name; + snprintf (numbuf, NUMBUF_LEN, "%i", i); + newname_len = IDENTIFIER_LENGTH (name) + + strlen (numbuf) + 2; + newname = (char*)alloca (newname_len); + snprintf (newname, newname_len, + "%s#%i", IDENTIFIER_POINTER (name), i); + return get_identifier (newname); +} + +/* Return true if T is a primary function, class or alias template + instantiation. */ + +bool +primary_template_instantiation_p (const_tree t) +{ + if (!t) + return false; + + if (TREE_CODE (t) == FUNCTION_DECL) + return DECL_LANG_SPECIFIC (t) + && DECL_TEMPLATE_INSTANTIATION (t) + && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t)); + else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t))) + return CLASSTYPE_TEMPLATE_INSTANTIATION (t) + && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t)); + else if (alias_template_specialization_p (t)) + return true; + return false; +} + +/* Return true if PARM is a template template parameter. */ + +bool +template_template_parameter_p (const_tree parm) +{ + return DECL_TEMPLATE_TEMPLATE_PARM_P (parm); +} + +/* Return true iff PARM is a DECL representing a type template + parameter. */ + +bool +template_type_parameter_p (const_tree parm) +{ + return (parm + && (TREE_CODE (parm) == TYPE_DECL + || TREE_CODE (parm) == TEMPLATE_DECL) + && DECL_TEMPLATE_PARM_P (parm)); +} + +/* Return the template parameters of T if T is a + primary template instantiation, NULL otherwise. */ + +tree +get_primary_template_innermost_parameters (const_tree t) +{ + tree parms = NULL, template_info = NULL; + + if ((template_info = get_template_info (t)) + && primary_template_instantiation_p (t)) + parms = INNERMOST_TEMPLATE_PARMS + (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info))); + + return parms; +} + +/* Return the template parameters of the LEVELth level from the full list + of template parameters PARMS. */ + +tree +get_template_parms_at_level (tree parms, int level) +{ + tree p; + if (!parms + || TREE_CODE (parms) != TREE_LIST + || level > TMPL_PARMS_DEPTH (parms)) + return NULL_TREE; + + for (p = parms; p; p = TREE_CHAIN (p)) + if (TMPL_PARMS_DEPTH (p) == level) + return p; + + return NULL_TREE; +} + +/* Returns the template arguments of T if T is a template instantiation, + NULL otherwise. */ + +tree +get_template_innermost_arguments (const_tree t) +{ + tree args = NULL, template_info = NULL; + + if ((template_info = get_template_info (t)) + && TI_ARGS (template_info)) + args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info)); + + return args; +} + +/* Return the argument pack elements of T if T is a template argument pack, + NULL otherwise. */ + +tree +get_template_argument_pack_elems (const_tree t) +{ + if (TREE_CODE (t) != TYPE_ARGUMENT_PACK + && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK) + return NULL; + + return ARGUMENT_PACK_ARGS (t); +} + +/* Structure used to track the progress of find_parameter_packs_r. */ +struct find_parameter_pack_data +{ + /* TREE_LIST that will contain all of the parameter packs found by + the traversal. */ + tree* parameter_packs; + + /* Set of AST nodes that have been visited by the traversal. */ + struct pointer_set_t *visited; +}; + +/* Identifies all of the argument packs that occur in a template + argument and appends them to the TREE_LIST inside DATA, which is a + find_parameter_pack_data structure. This is a subroutine of + make_pack_expansion and uses_parameter_packs. */ +static tree +find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data) +{ + tree t = *tp; + struct find_parameter_pack_data* ppd = + (struct find_parameter_pack_data*)data; + bool parameter_pack_p = false; + + /* Handle type aliases/typedefs. */ + if (TYPE_ALIAS_P (t)) + { + if (TYPE_TEMPLATE_INFO (t)) + cp_walk_tree (&TYPE_TI_ARGS (t), + &find_parameter_packs_r, + ppd, ppd->visited); + *walk_subtrees = 0; + return NULL_TREE; + } + + /* Identify whether this is a parameter pack or not. */ + switch (TREE_CODE (t)) + { + case TEMPLATE_PARM_INDEX: + if (TEMPLATE_PARM_PARAMETER_PACK (t)) + parameter_pack_p = true; + break; + + case TEMPLATE_TYPE_PARM: + t = TYPE_MAIN_VARIANT (t); + case TEMPLATE_TEMPLATE_PARM: + if (TEMPLATE_TYPE_PARAMETER_PACK (t)) + parameter_pack_p = true; + break; + + case FIELD_DECL: + case PARM_DECL: + if (DECL_PACK_P (t)) + { + /* We don't want to walk into the type of a PARM_DECL, + because we don't want to see the type parameter pack. */ + *walk_subtrees = 0; + parameter_pack_p = true; + } + break; + + /* Look through a lambda capture proxy to the field pack. */ + case VAR_DECL: + if (DECL_HAS_VALUE_EXPR_P (t)) + { + tree v = DECL_VALUE_EXPR (t); + cp_walk_tree (&v, + &find_parameter_packs_r, + ppd, ppd->visited); + *walk_subtrees = 0; + } + break; + + case BASES: + parameter_pack_p = true; + break; + default: + /* Not a parameter pack. */ + break; + } + + if (parameter_pack_p) + { + /* Add this parameter pack to the list. */ + *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs); + } + + if (TYPE_P (t)) + cp_walk_tree (&TYPE_CONTEXT (t), + &find_parameter_packs_r, ppd, ppd->visited); + + /* This switch statement will return immediately if we don't find a + parameter pack. */ + switch (TREE_CODE (t)) + { + case TEMPLATE_PARM_INDEX: + return NULL_TREE; + + case BOUND_TEMPLATE_TEMPLATE_PARM: + /* Check the template itself. */ + cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)), + &find_parameter_packs_r, ppd, ppd->visited); + /* Check the template arguments. */ + cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd, + ppd->visited); + *walk_subtrees = 0; + return NULL_TREE; + + case TEMPLATE_TYPE_PARM: + case TEMPLATE_TEMPLATE_PARM: + return NULL_TREE; + + case PARM_DECL: + return NULL_TREE; + + case RECORD_TYPE: + if (TYPE_PTRMEMFUNC_P (t)) + return NULL_TREE; + /* Fall through. */ + + case UNION_TYPE: + case ENUMERAL_TYPE: + if (TYPE_TEMPLATE_INFO (t)) + cp_walk_tree (&TYPE_TI_ARGS (t), + &find_parameter_packs_r, ppd, ppd->visited); + + *walk_subtrees = 0; + return NULL_TREE; + + case CONSTRUCTOR: + case TEMPLATE_DECL: + cp_walk_tree (&TREE_TYPE (t), + &find_parameter_packs_r, ppd, ppd->visited); + return NULL_TREE; + + case TYPENAME_TYPE: + cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r, + ppd, ppd->visited); + *walk_subtrees = 0; + return NULL_TREE; + + case TYPE_PACK_EXPANSION: + case EXPR_PACK_EXPANSION: + *walk_subtrees = 0; + return NULL_TREE; + + case INTEGER_TYPE: + cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r, + ppd, ppd->visited); + *walk_subtrees = 0; + return NULL_TREE; + + case IDENTIFIER_NODE: + cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd, + ppd->visited); + *walk_subtrees = 0; + return NULL_TREE; + + default: + return NULL_TREE; + } + + return NULL_TREE; +} + +/* Determines if the expression or type T uses any parameter packs. */ +bool +uses_parameter_packs (tree t) +{ + tree parameter_packs = NULL_TREE; + struct find_parameter_pack_data ppd; + ppd.parameter_packs = ¶meter_packs; + ppd.visited = pointer_set_create (); + cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited); + pointer_set_destroy (ppd.visited); + return parameter_packs != NULL_TREE; +} + +/* Turn ARG, which may be an expression, type, or a TREE_LIST + representation a base-class initializer into a parameter pack + expansion. If all goes well, the resulting node will be an + EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST, + respectively. */ +tree +make_pack_expansion (tree arg) +{ + tree result; + tree parameter_packs = NULL_TREE; + bool for_types = false; + struct find_parameter_pack_data ppd; + + if (!arg || arg == error_mark_node) + return arg; + + if (TREE_CODE (arg) == TREE_LIST) + { + /* The only time we will see a TREE_LIST here is for a base + class initializer. In this case, the TREE_PURPOSE will be a + _TYPE node (representing the base class expansion we're + initializing) and the TREE_VALUE will be a TREE_LIST + containing the initialization arguments. + + The resulting expansion looks somewhat different from most + expansions. Rather than returning just one _EXPANSION, we + return a TREE_LIST whose TREE_PURPOSE is a + TYPE_PACK_EXPANSION containing the bases that will be + initialized. The TREE_VALUE will be identical to the + original TREE_VALUE, which is a list of arguments that will + be passed to each base. We do not introduce any new pack + expansion nodes into the TREE_VALUE (although it is possible + that some already exist), because the TREE_PURPOSE and + TREE_VALUE all need to be expanded together with the same + _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the + resulting TREE_PURPOSE will mention the parameter packs in + both the bases and the arguments to the bases. */ + tree purpose; + tree value; + tree parameter_packs = NULL_TREE; + + /* Determine which parameter packs will be used by the base + class expansion. */ + ppd.visited = pointer_set_create (); + ppd.parameter_packs = ¶meter_packs; + cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r, + &ppd, ppd.visited); + + if (parameter_packs == NULL_TREE) + { + error ("base initializer expansion %<%T%> contains no parameter packs", arg); + pointer_set_destroy (ppd.visited); + return error_mark_node; + } + + if (TREE_VALUE (arg) != void_type_node) + { + /* Collect the sets of parameter packs used in each of the + initialization arguments. */ + for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value)) + { + /* Determine which parameter packs will be expanded in this + argument. */ + cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r, + &ppd, ppd.visited); + } + } + + pointer_set_destroy (ppd.visited); + + /* Create the pack expansion type for the base type. */ + purpose = cxx_make_type (TYPE_PACK_EXPANSION); + SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg)); + PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs; + + /* Just use structural equality for these TYPE_PACK_EXPANSIONS; + they will rarely be compared to anything. */ + SET_TYPE_STRUCTURAL_EQUALITY (purpose); + + return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE); + } + + if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL) + for_types = true; + + /* Build the PACK_EXPANSION_* node. */ + result = for_types + ? cxx_make_type (TYPE_PACK_EXPANSION) + : make_node (EXPR_PACK_EXPANSION); + SET_PACK_EXPANSION_PATTERN (result, arg); + if (TREE_CODE (result) == EXPR_PACK_EXPANSION) + { + /* Propagate type and const-expression information. */ + TREE_TYPE (result) = TREE_TYPE (arg); + TREE_CONSTANT (result) = TREE_CONSTANT (arg); + } + else + /* Just use structural equality for these TYPE_PACK_EXPANSIONS; + they will rarely be compared to anything. */ + SET_TYPE_STRUCTURAL_EQUALITY (result); + + /* Determine which parameter packs will be expanded. */ + ppd.parameter_packs = ¶meter_packs; + ppd.visited = pointer_set_create (); + cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited); + pointer_set_destroy (ppd.visited); + + /* Make sure we found some parameter packs. */ + if (parameter_packs == NULL_TREE) + { + if (TYPE_P (arg)) + error ("expansion pattern %<%T%> contains no argument packs", arg); + else + error ("expansion pattern %<%E%> contains no argument packs", arg); + return error_mark_node; + } + PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs; + + PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p (); + + return result; +} + +/* Checks T for any "bare" parameter packs, which have not yet been + expanded, and issues an error if any are found. This operation can + only be done on full expressions or types (e.g., an expression + statement, "if" condition, etc.), because we could have expressions like: + + foo(f(g(h(args)))...) + + where "args" is a parameter pack. check_for_bare_parameter_packs + should not be called for the subexpressions args, h(args), + g(h(args)), or f(g(h(args))), because we would produce erroneous + error messages. + + Returns TRUE and emits an error if there were bare parameter packs, + returns FALSE otherwise. */ +bool +check_for_bare_parameter_packs (tree t) +{ + tree parameter_packs = NULL_TREE; + struct find_parameter_pack_data ppd; + + if (!processing_template_decl || !t || t == error_mark_node) + return false; + + if (TREE_CODE (t) == TYPE_DECL) + t = TREE_TYPE (t); + + ppd.parameter_packs = ¶meter_packs; + ppd.visited = pointer_set_create (); + cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited); + pointer_set_destroy (ppd.visited); + + if (parameter_packs) + { + error ("parameter packs not expanded with %<...%>:"); + while (parameter_packs) + { + tree pack = TREE_VALUE (parameter_packs); + tree name = NULL_TREE; + + if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM + || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM) + name = TYPE_NAME (pack); + else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX) + name = DECL_NAME (TEMPLATE_PARM_DECL (pack)); + else + name = DECL_NAME (pack); + + if (name) + inform (input_location, " %qD", name); + else + inform (input_location, " <anonymous>"); + + parameter_packs = TREE_CHAIN (parameter_packs); + } + + return true; + } + + return false; +} + +/* Expand any parameter packs that occur in the template arguments in + ARGS. */ +tree +expand_template_argument_pack (tree args) +{ + tree result_args = NULL_TREE; + int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0; + int num_result_args = -1; + int non_default_args_count = -1; + + /* First, determine if we need to expand anything, and the number of + slots we'll need. */ + for (in_arg = 0; in_arg < nargs; ++in_arg) + { + tree arg = TREE_VEC_ELT (args, in_arg); + if (arg == NULL_TREE) + return args; + if (ARGUMENT_PACK_P (arg)) + { + int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg)); + if (num_result_args < 0) + num_result_args = in_arg + num_packed; + else + num_result_args += num_packed; + } + else + { + if (num_result_args >= 0) + num_result_args++; + } + } + + /* If no expansion is necessary, we're done. */ + if (num_result_args < 0) + return args; + + /* Expand arguments. */ + result_args = make_tree_vec (num_result_args); + if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args)) + non_default_args_count = + GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args); + for (in_arg = 0; in_arg < nargs; ++in_arg) + { + tree arg = TREE_VEC_ELT (args, in_arg); + if (ARGUMENT_PACK_P (arg)) + { + tree packed = ARGUMENT_PACK_ARGS (arg); + int i, num_packed = TREE_VEC_LENGTH (packed); + for (i = 0; i < num_packed; ++i, ++out_arg) + TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i); + if (non_default_args_count > 0) + non_default_args_count += num_packed - 1; + } + else + { + TREE_VEC_ELT (result_args, out_arg) = arg; + ++out_arg; + } + } + if (non_default_args_count >= 0) + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count); + return result_args; +} + +/* Checks if DECL shadows a template parameter. + + [temp.local]: A template-parameter shall not be redeclared within its + scope (including nested scopes). + + Emits an error and returns TRUE if the DECL shadows a parameter, + returns FALSE otherwise. */ + +bool +check_template_shadow (tree decl) +{ + tree olddecl; + + /* If we're not in a template, we can't possibly shadow a template + parameter. */ + if (!current_template_parms) + return true; + + /* Figure out what we're shadowing. */ + if (TREE_CODE (decl) == OVERLOAD) + decl = OVL_CURRENT (decl); + olddecl = innermost_non_namespace_value (DECL_NAME (decl)); + + /* If there's no previous binding for this name, we're not shadowing + anything, let alone a template parameter. */ + if (!olddecl) + return true; + + /* If we're not shadowing a template parameter, we're done. Note + that OLDDECL might be an OVERLOAD (or perhaps even an + ERROR_MARK), so we can't just blithely assume it to be a _DECL + node. */ + if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl)) + return true; + + /* We check for decl != olddecl to avoid bogus errors for using a + name inside a class. We check TPFI to avoid duplicate errors for + inline member templates. */ + if (decl == olddecl + || (DECL_TEMPLATE_PARM_P (decl) + && TEMPLATE_PARMS_FOR_INLINE (current_template_parms))) + return true; + + /* Don't complain about the injected class name, as we've already + complained about the class itself. */ + if (DECL_SELF_REFERENCE_P (decl)) + return false; + + error ("declaration of %q+#D", decl); + error (" shadows template parm %q+#D", olddecl); + return false; +} + +/* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL, + ORIG_LEVEL, DECL, and TYPE. */ + +static tree +build_template_parm_index (int index, + int level, + int orig_level, + tree decl, + tree type) +{ + tree t = make_node (TEMPLATE_PARM_INDEX); + TEMPLATE_PARM_IDX (t) = index; + TEMPLATE_PARM_LEVEL (t) = level; + TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level; + TEMPLATE_PARM_DECL (t) = decl; + TREE_TYPE (t) = type; + TREE_CONSTANT (t) = TREE_CONSTANT (decl); + TREE_READONLY (t) = TREE_READONLY (decl); + + return t; +} + +/* Find the canonical type parameter for the given template type + parameter. Returns the canonical type parameter, which may be TYPE + if no such parameter existed. */ + +static tree +canonical_type_parameter (tree type) +{ + tree list; + int idx = TEMPLATE_TYPE_IDX (type); + if (!canonical_template_parms) + vec_alloc (canonical_template_parms, idx+1); + + while (canonical_template_parms->length () <= (unsigned)idx) + vec_safe_push (canonical_template_parms, NULL_TREE); + + list = (*canonical_template_parms)[idx]; + while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL)) + list = TREE_CHAIN (list); + + if (list) + return TREE_VALUE (list); + else + { + (*canonical_template_parms)[idx] + = tree_cons (NULL_TREE, type, + (*canonical_template_parms)[idx]); + return type; + } +} + +/* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose + TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a + TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a + new one is created. */ + +static tree +reduce_template_parm_level (tree index, tree type, int levels, tree args, + tsubst_flags_t complain) +{ + if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE + || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index)) + != TEMPLATE_PARM_LEVEL (index) - levels) + || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index)))) + { + tree orig_decl = TEMPLATE_PARM_DECL (index); + tree decl, t; + + decl = build_decl (DECL_SOURCE_LOCATION (orig_decl), + TREE_CODE (orig_decl), DECL_NAME (orig_decl), type); + TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl); + TREE_READONLY (decl) = TREE_READONLY (orig_decl); + DECL_ARTIFICIAL (decl) = 1; + SET_DECL_TEMPLATE_PARM_P (decl); + + t = build_template_parm_index (TEMPLATE_PARM_IDX (index), + TEMPLATE_PARM_LEVEL (index) - levels, + TEMPLATE_PARM_ORIG_LEVEL (index), + decl, type); + TEMPLATE_PARM_DESCENDANTS (index) = t; + TEMPLATE_PARM_PARAMETER_PACK (t) + = TEMPLATE_PARM_PARAMETER_PACK (index); + + /* Template template parameters need this. */ + if (TREE_CODE (decl) == TEMPLATE_DECL) + DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms + (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)), + args, complain); + } + + return TEMPLATE_PARM_DESCENDANTS (index); +} + +/* Process information from new template parameter PARM and append it + to the LIST being built. This new parameter is a non-type + parameter iff IS_NON_TYPE is true. This new parameter is a + parameter pack iff IS_PARAMETER_PACK is true. The location of PARM + is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template + parameter list PARM belongs to. This is used used to create a + proper canonical type for the type of PARM that is to be created, + iff PARM is a type. If the size is not known, this parameter shall + be set to 0. */ + +tree +process_template_parm (tree list, location_t parm_loc, tree parm, + bool is_non_type, bool is_parameter_pack) +{ + tree decl = 0; + tree defval; + tree err_parm_list; + int idx = 0; + + gcc_assert (TREE_CODE (parm) == TREE_LIST); + defval = TREE_PURPOSE (parm); + + if (list) + { + tree p = tree_last (list); + + if (p && TREE_VALUE (p) != error_mark_node) + { + p = TREE_VALUE (p); + if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL) + idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p)); + else + idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p)); + } + + ++idx; + } + else + idx = 0; + + if (is_non_type) + { + parm = TREE_VALUE (parm); + + SET_DECL_TEMPLATE_PARM_P (parm); + + if (TREE_TYPE (parm) == error_mark_node) + { + err_parm_list = build_tree_list (defval, parm); + TREE_VALUE (err_parm_list) = error_mark_node; + return chainon (list, err_parm_list); + } + else + { + /* [temp.param] + + The top-level cv-qualifiers on the template-parameter are + ignored when determining its type. */ + TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm)); + if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1)) + { + err_parm_list = build_tree_list (defval, parm); + TREE_VALUE (err_parm_list) = error_mark_node; + return chainon (list, err_parm_list); + } + + if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack + /* If we're in a nested template parameter list, the template + template parameter could be a parameter pack. */ + && processing_template_parmlist == 1) + { + /* This template parameter is not a parameter pack, but it + should be. Complain about "bare" parameter packs. */ + check_for_bare_parameter_packs (TREE_TYPE (parm)); + + /* Recover by calling this a parameter pack. */ + is_parameter_pack = true; + } + } + + /* A template parameter is not modifiable. */ + TREE_CONSTANT (parm) = 1; + TREE_READONLY (parm) = 1; + decl = build_decl (parm_loc, + CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm)); + TREE_CONSTANT (decl) = 1; + TREE_READONLY (decl) = 1; + DECL_INITIAL (parm) = DECL_INITIAL (decl) + = build_template_parm_index (idx, processing_template_decl, + processing_template_decl, + decl, TREE_TYPE (parm)); + + TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)) + = is_parameter_pack; + } + else + { + tree t; + parm = TREE_VALUE (TREE_VALUE (parm)); + + if (parm && TREE_CODE (parm) == TEMPLATE_DECL) + { + t = cxx_make_type (TEMPLATE_TEMPLATE_PARM); + /* This is for distinguishing between real templates and template + template parameters */ + TREE_TYPE (parm) = t; + TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t; + decl = parm; + } + else + { + t = cxx_make_type (TEMPLATE_TYPE_PARM); + /* parm is either IDENTIFIER_NODE or NULL_TREE. */ + decl = build_decl (parm_loc, + TYPE_DECL, parm, t); + } + + TYPE_NAME (t) = decl; + TYPE_STUB_DECL (t) = decl; + parm = decl; + TEMPLATE_TYPE_PARM_INDEX (t) + = build_template_parm_index (idx, processing_template_decl, + processing_template_decl, + decl, TREE_TYPE (parm)); + TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack; + TYPE_CANONICAL (t) = canonical_type_parameter (t); + } + DECL_ARTIFICIAL (decl) = 1; + SET_DECL_TEMPLATE_PARM_P (decl); + pushdecl (decl); + parm = build_tree_list (defval, parm); + return chainon (list, parm); +} + +/* The end of a template parameter list has been reached. Process the + tree list into a parameter vector, converting each parameter into a more + useful form. Type parameters are saved as IDENTIFIER_NODEs, and others + as PARM_DECLs. */ + +tree +end_template_parm_list (tree parms) +{ + int nparms; + tree parm, next; + tree saved_parmlist = make_tree_vec (list_length (parms)); + + current_template_parms + = tree_cons (size_int (processing_template_decl), + saved_parmlist, current_template_parms); + + for (parm = parms, nparms = 0; parm; parm = next, nparms++) + { + next = TREE_CHAIN (parm); + TREE_VEC_ELT (saved_parmlist, nparms) = parm; + TREE_CHAIN (parm) = NULL_TREE; + } + + --processing_template_parmlist; + + return saved_parmlist; +} + +/* end_template_decl is called after a template declaration is seen. */ + +void +end_template_decl (void) +{ + reset_specialization (); + + if (! processing_template_decl) + return; + + /* This matches the pushlevel in begin_template_parm_list. */ + finish_scope (); + + --processing_template_decl; + current_template_parms = TREE_CHAIN (current_template_parms); +} + +/* Takes a TREE_LIST representing a template parameter and convert it + into an argument suitable to be passed to the type substitution + functions. Note that If the TREE_LIST contains an error_mark + node, the returned argument is error_mark_node. */ + +static tree +template_parm_to_arg (tree t) +{ + + if (t == NULL_TREE + || TREE_CODE (t) != TREE_LIST) + return t; + + if (error_operand_p (TREE_VALUE (t))) + return error_mark_node; + + t = TREE_VALUE (t); + + if (TREE_CODE (t) == TYPE_DECL + || TREE_CODE (t) == TEMPLATE_DECL) + { + t = TREE_TYPE (t); + + if (TEMPLATE_TYPE_PARAMETER_PACK (t)) + { + /* Turn this argument into a TYPE_ARGUMENT_PACK + with a single element, which expands T. */ + tree vec = make_tree_vec (1); +#ifdef ENABLE_CHECKING + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT + (vec, TREE_VEC_LENGTH (vec)); +#endif + TREE_VEC_ELT (vec, 0) = make_pack_expansion (t); + + t = cxx_make_type (TYPE_ARGUMENT_PACK); + SET_ARGUMENT_PACK_ARGS (t, vec); + } + } + else + { + t = DECL_INITIAL (t); + + if (TEMPLATE_PARM_PARAMETER_PACK (t)) + { + /* Turn this argument into a NONTYPE_ARGUMENT_PACK + with a single element, which expands T. */ + tree vec = make_tree_vec (1); + tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t)); +#ifdef ENABLE_CHECKING + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT + (vec, TREE_VEC_LENGTH (vec)); +#endif + t = convert_from_reference (t); + TREE_VEC_ELT (vec, 0) = make_pack_expansion (t); + + t = make_node (NONTYPE_ARGUMENT_PACK); + SET_ARGUMENT_PACK_ARGS (t, vec); + TREE_TYPE (t) = type; + } + else + t = convert_from_reference (t); + } + return t; +} + +/* Given a set of template parameters, return them as a set of template + arguments. The template parameters are represented as a TREE_VEC, in + the form documented in cp-tree.h for template arguments. */ + +static tree +template_parms_to_args (tree parms) +{ + tree header; + tree args = NULL_TREE; + int length = TMPL_PARMS_DEPTH (parms); + int l = length; + + /* If there is only one level of template parameters, we do not + create a TREE_VEC of TREE_VECs. Instead, we return a single + TREE_VEC containing the arguments. */ + if (length > 1) + args = make_tree_vec (length); + + for (header = parms; header; header = TREE_CHAIN (header)) + { + tree a = copy_node (TREE_VALUE (header)); + int i; + + TREE_TYPE (a) = NULL_TREE; + for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i) + TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i)); + +#ifdef ENABLE_CHECKING + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a)); +#endif + + if (length > 1) + TREE_VEC_ELT (args, --l) = a; + else + args = a; + } + + if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE) + /* This can happen for template parms of a template template + parameter, e.g: + + template<template<class T, class U> class TT> struct S; + + Consider the level of the parms of TT; T and U both have + level 2; TT has no template parm of level 1. So in this case + the first element of full_template_args is NULL_TREE. If we + leave it like this TMPL_ARGS_DEPTH on args returns 1 instead + of 2. This will make tsubst wrongly consider that T and U + have level 1. Instead, let's create a dummy vector as the + first element of full_template_args so that TMPL_ARGS_DEPTH + returns the correct depth for args. */ + TREE_VEC_ELT (args, 0) = make_tree_vec (1); + return args; +} + +/* Within the declaration of a template, return the currently active + template parameters as an argument TREE_VEC. */ + +static tree +current_template_args (void) +{ + return template_parms_to_args (current_template_parms); +} + +/* Update the declared TYPE by doing any lookups which were thought to be + dependent, but are not now that we know the SCOPE of the declarator. */ + +tree +maybe_update_decl_type (tree orig_type, tree scope) +{ + tree type = orig_type; + + if (type == NULL_TREE) + return type; + + if (TREE_CODE (orig_type) == TYPE_DECL) + type = TREE_TYPE (type); + + if (scope && TYPE_P (scope) && dependent_type_p (scope) + && dependent_type_p (type) + /* Don't bother building up the args in this case. */ + && TREE_CODE (type) != TEMPLATE_TYPE_PARM) + { + /* tsubst in the args corresponding to the template parameters, + including auto if present. Most things will be unchanged, but + make_typename_type and tsubst_qualified_id will resolve + TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */ + tree args = current_template_args (); + tree auto_node = type_uses_auto (type); + tree pushed; + if (auto_node) + { + tree auto_vec = make_tree_vec (1); + TREE_VEC_ELT (auto_vec, 0) = auto_node; + args = add_to_template_args (args, auto_vec); + } + pushed = push_scope (scope); + type = tsubst (type, args, tf_warning_or_error, NULL_TREE); + if (pushed) + pop_scope (scope); + } + + if (type == error_mark_node) + return orig_type; + + if (TREE_CODE (orig_type) == TYPE_DECL) + { + if (same_type_p (type, TREE_TYPE (orig_type))) + type = orig_type; + else + type = TYPE_NAME (type); + } + return type; +} + +/* Return a TEMPLATE_DECL corresponding to DECL, using the indicated + template PARMS. If MEMBER_TEMPLATE_P is true, the new template is + a member template. Used by push_template_decl below. */ + +static tree +build_template_decl (tree decl, tree parms, bool member_template_p) +{ + tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE); + DECL_TEMPLATE_PARMS (tmpl) = parms; + DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl); + DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl); + DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p; + + return tmpl; +} + +struct template_parm_data +{ + /* The level of the template parameters we are currently + processing. */ + int level; + + /* The index of the specialization argument we are currently + processing. */ + int current_arg; + + /* An array whose size is the number of template parameters. The + elements are nonzero if the parameter has been used in any one + of the arguments processed so far. */ + int* parms; + + /* An array whose size is the number of template arguments. The + elements are nonzero if the argument makes use of template + parameters of this level. */ + int* arg_uses_template_parms; +}; + +/* Subroutine of push_template_decl used to see if each template + parameter in a partial specialization is used in the explicit + argument list. If T is of the LEVEL given in DATA (which is + treated as a template_parm_data*), then DATA->PARMS is marked + appropriately. */ + +static int +mark_template_parm (tree t, void* data) +{ + int level; + int idx; + struct template_parm_data* tpd = (struct template_parm_data*) data; + + if (TREE_CODE (t) == TEMPLATE_PARM_INDEX) + { + level = TEMPLATE_PARM_LEVEL (t); + idx = TEMPLATE_PARM_IDX (t); + } + else + { + level = TEMPLATE_TYPE_LEVEL (t); + idx = TEMPLATE_TYPE_IDX (t); + } + + if (level == tpd->level) + { + tpd->parms[idx] = 1; + tpd->arg_uses_template_parms[tpd->current_arg] = 1; + } + + /* Return zero so that for_each_template_parm will continue the + traversal of the tree; we want to mark *every* template parm. */ + return 0; +} + +/* Process the partial specialization DECL. */ + +static tree +process_partial_specialization (tree decl) +{ + tree type = TREE_TYPE (decl); + tree maintmpl = CLASSTYPE_TI_TEMPLATE (type); + tree specargs = CLASSTYPE_TI_ARGS (type); + tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs); + tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl); + tree inner_parms; + tree inst; + int nargs = TREE_VEC_LENGTH (inner_args); + int ntparms; + int i; + bool did_error_intro = false; + struct template_parm_data tpd; + struct template_parm_data tpd2; + + gcc_assert (current_template_parms); + + inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms); + ntparms = TREE_VEC_LENGTH (inner_parms); + + /* We check that each of the template parameters given in the + partial specialization is used in the argument list to the + specialization. For example: + + template <class T> struct S; + template <class T> struct S<T*>; + + The second declaration is OK because `T*' uses the template + parameter T, whereas + + template <class T> struct S<int>; + + is no good. Even trickier is: + + template <class T> + struct S1 + { + template <class U> + struct S2; + template <class U> + struct S2<T>; + }; + + The S2<T> declaration is actually invalid; it is a + full-specialization. Of course, + + template <class U> + struct S2<T (*)(U)>; + + or some such would have been OK. */ + tpd.level = TMPL_PARMS_DEPTH (current_template_parms); + tpd.parms = XALLOCAVEC (int, ntparms); + memset (tpd.parms, 0, sizeof (int) * ntparms); + + tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs); + memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs); + for (i = 0; i < nargs; ++i) + { + tpd.current_arg = i; + for_each_template_parm (TREE_VEC_ELT (inner_args, i), + &mark_template_parm, + &tpd, + NULL, + /*include_nondeduced_p=*/false); + } + for (i = 0; i < ntparms; ++i) + if (tpd.parms[i] == 0) + { + /* One of the template parms was not used in the + specialization. */ + if (!did_error_intro) + { + error ("template parameters not used in partial specialization:"); + did_error_intro = true; + } + + error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i))); + } + + if (did_error_intro) + return error_mark_node; + + /* [temp.class.spec] + + The argument list of the specialization shall not be identical to + the implicit argument list of the primary template. */ + if (comp_template_args + (inner_args, + INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE + (maintmpl))))) + error ("partial specialization %qT does not specialize any template arguments", type); + + /* A partial specialization that replaces multiple parameters of the + primary template with a pack expansion is less specialized for those + parameters. */ + if (nargs < DECL_NTPARMS (maintmpl)) + { + error ("partial specialization is not more specialized than the " + "primary template because it replaces multiple parameters " + "with a pack expansion"); + inform (DECL_SOURCE_LOCATION (maintmpl), "primary template here"); + return decl; + } + + /* [temp.class.spec] + + A partially specialized non-type argument expression shall not + involve template parameters of the partial specialization except + when the argument expression is a simple identifier. + + The type of a template parameter corresponding to a specialized + non-type argument shall not be dependent on a parameter of the + specialization. + + Also, we verify that pack expansions only occur at the + end of the argument list. */ + gcc_assert (nargs == DECL_NTPARMS (maintmpl)); + tpd2.parms = 0; + for (i = 0; i < nargs; ++i) + { + tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i)); + tree arg = TREE_VEC_ELT (inner_args, i); + tree packed_args = NULL_TREE; + int j, len = 1; + + if (ARGUMENT_PACK_P (arg)) + { + /* Extract the arguments from the argument pack. We'll be + iterating over these in the following loop. */ + packed_args = ARGUMENT_PACK_ARGS (arg); + len = TREE_VEC_LENGTH (packed_args); + } + + for (j = 0; j < len; j++) + { + if (packed_args) + /* Get the Jth argument in the parameter pack. */ + arg = TREE_VEC_ELT (packed_args, j); + + if (PACK_EXPANSION_P (arg)) + { + /* Pack expansions must come at the end of the + argument list. */ + if ((packed_args && j < len - 1) + || (!packed_args && i < nargs - 1)) + { + if (TREE_CODE (arg) == EXPR_PACK_EXPANSION) + error ("parameter pack argument %qE must be at the " + "end of the template argument list", arg); + else + error ("parameter pack argument %qT must be at the " + "end of the template argument list", arg); + } + } + + if (TREE_CODE (arg) == EXPR_PACK_EXPANSION) + /* We only care about the pattern. */ + arg = PACK_EXPANSION_PATTERN (arg); + + if (/* These first two lines are the `non-type' bit. */ + !TYPE_P (arg) + && TREE_CODE (arg) != TEMPLATE_DECL + /* This next two lines are the `argument expression is not just a + simple identifier' condition and also the `specialized + non-type argument' bit. */ + && TREE_CODE (arg) != TEMPLATE_PARM_INDEX + && !(REFERENCE_REF_P (arg) + && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_PARM_INDEX)) + { + if ((!packed_args && tpd.arg_uses_template_parms[i]) + || (packed_args && uses_template_parms (arg))) + error ("template argument %qE involves template parameter(s)", + arg); + else + { + /* Look at the corresponding template parameter, + marking which template parameters its type depends + upon. */ + tree type = TREE_TYPE (parm); + + if (!tpd2.parms) + { + /* We haven't yet initialized TPD2. Do so now. */ + tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs); + /* The number of parameters here is the number in the + main template, which, as checked in the assertion + above, is NARGS. */ + tpd2.parms = XALLOCAVEC (int, nargs); + tpd2.level = + TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl)); + } + + /* Mark the template parameters. But this time, we're + looking for the template parameters of the main + template, not in the specialization. */ + tpd2.current_arg = i; + tpd2.arg_uses_template_parms[i] = 0; + memset (tpd2.parms, 0, sizeof (int) * nargs); + for_each_template_parm (type, + &mark_template_parm, + &tpd2, + NULL, + /*include_nondeduced_p=*/false); + + if (tpd2.arg_uses_template_parms [i]) + { + /* The type depended on some template parameters. + If they are fully specialized in the + specialization, that's OK. */ + int j; + int count = 0; + for (j = 0; j < nargs; ++j) + if (tpd2.parms[j] != 0 + && tpd.arg_uses_template_parms [j]) + ++count; + if (count != 0) + error_n (input_location, count, + "type %qT of template argument %qE depends " + "on a template parameter", + "type %qT of template argument %qE depends " + "on template parameters", + type, + arg); + } + } + } + } + } + + /* We should only get here once. */ + gcc_assert (!COMPLETE_TYPE_P (type)); + + tree tmpl = build_template_decl (decl, current_template_parms, + DECL_MEMBER_TEMPLATE_P (maintmpl)); + TREE_TYPE (tmpl) = type; + DECL_TEMPLATE_RESULT (tmpl) = decl; + SET_DECL_TEMPLATE_SPECIALIZATION (tmpl); + DECL_TEMPLATE_INFO (tmpl) = build_template_info (maintmpl, specargs); + DECL_PRIMARY_TEMPLATE (tmpl) = maintmpl; + + DECL_TEMPLATE_SPECIALIZATIONS (maintmpl) + = tree_cons (specargs, tmpl, + DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)); + TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type; + + for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst; + inst = TREE_CHAIN (inst)) + { + tree inst_type = TREE_VALUE (inst); + if (COMPLETE_TYPE_P (inst_type) + && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type)) + { + tree spec = most_specialized_class (inst_type, tf_none); + if (spec && TREE_TYPE (spec) == type) + permerror (input_location, + "partial specialization of %qT after instantiation " + "of %qT", type, inst_type); + } + } + + return decl; +} + +/* PARM is a template parameter of some form; return the corresponding + TEMPLATE_PARM_INDEX. */ + +static tree +get_template_parm_index (tree parm) +{ + if (TREE_CODE (parm) == PARM_DECL + || TREE_CODE (parm) == CONST_DECL) + parm = DECL_INITIAL (parm); + else if (TREE_CODE (parm) == TYPE_DECL + || TREE_CODE (parm) == TEMPLATE_DECL) + parm = TREE_TYPE (parm); + if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM + || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM) + parm = TEMPLATE_TYPE_PARM_INDEX (parm); + gcc_assert (TREE_CODE (parm) == TEMPLATE_PARM_INDEX); + return parm; +} + +/* Subroutine of fixed_parameter_pack_p below. Look for any template + parameter packs used by the template parameter PARM. */ + +static void +fixed_parameter_pack_p_1 (tree parm, struct find_parameter_pack_data *ppd) +{ + /* A type parm can't refer to another parm. */ + if (TREE_CODE (parm) == TYPE_DECL) + return; + else if (TREE_CODE (parm) == PARM_DECL) + { + cp_walk_tree (&TREE_TYPE (parm), &find_parameter_packs_r, + ppd, ppd->visited); + return; + } + + gcc_assert (TREE_CODE (parm) == TEMPLATE_DECL); + + tree vec = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm)); + for (int i = 0; i < TREE_VEC_LENGTH (vec); ++i) + fixed_parameter_pack_p_1 (TREE_VALUE (TREE_VEC_ELT (vec, i)), ppd); +} + +/* PARM is a template parameter pack. Return any parameter packs used in + its type or the type of any of its template parameters. If there are + any such packs, it will be instantiated into a fixed template parameter + list by partial instantiation rather than be fully deduced. */ + +tree +fixed_parameter_pack_p (tree parm) +{ + /* This can only be true in a member template. */ + if (TEMPLATE_PARM_ORIG_LEVEL (get_template_parm_index (parm)) < 2) + return NULL_TREE; + /* This can only be true for a parameter pack. */ + if (!template_parameter_pack_p (parm)) + return NULL_TREE; + /* A type parm can't refer to another parm. */ + if (TREE_CODE (parm) == TYPE_DECL) + return NULL_TREE; + + tree parameter_packs = NULL_TREE; + struct find_parameter_pack_data ppd; + ppd.parameter_packs = ¶meter_packs; + ppd.visited = pointer_set_create (); + + fixed_parameter_pack_p_1 (parm, &ppd); + + pointer_set_destroy (ppd.visited); + return parameter_packs; +} + +/* Check that a template declaration's use of default arguments and + parameter packs is not invalid. Here, PARMS are the template + parameters. IS_PRIMARY is true if DECL is the thing declared by + a primary template. IS_PARTIAL is true if DECL is a partial + specialization. + + IS_FRIEND_DECL is nonzero if DECL is a friend function template + declaration (but not a definition); 1 indicates a declaration, 2 + indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are + emitted for extraneous default arguments. + + Returns TRUE if there were no errors found, FALSE otherwise. */ + +bool +check_default_tmpl_args (tree decl, tree parms, bool is_primary, + bool is_partial, int is_friend_decl) +{ + const char *msg; + int last_level_to_check; + tree parm_level; + bool no_errors = true; + + /* [temp.param] + + A default template-argument shall not be specified in a + function template declaration or a function template definition, nor + in the template-parameter-list of the definition of a member of a + class template. */ + + if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL) + /* You can't have a function template declaration in a local + scope, nor you can you define a member of a class template in a + local scope. */ + return true; + + if (TREE_CODE (decl) == TYPE_DECL + && TREE_TYPE (decl) + && LAMBDA_TYPE_P (TREE_TYPE (decl))) + /* A lambda doesn't have an explicit declaration; don't complain + about the parms of the enclosing class. */ + return true; + + if (current_class_type + && !TYPE_BEING_DEFINED (current_class_type) + && DECL_LANG_SPECIFIC (decl) + && DECL_DECLARES_FUNCTION_P (decl) + /* If this is either a friend defined in the scope of the class + or a member function. */ + && (DECL_FUNCTION_MEMBER_P (decl) + ? same_type_p (DECL_CONTEXT (decl), current_class_type) + : DECL_FRIEND_CONTEXT (decl) + ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type) + : false) + /* And, if it was a member function, it really was defined in + the scope of the class. */ + && (!DECL_FUNCTION_MEMBER_P (decl) + || DECL_INITIALIZED_IN_CLASS_P (decl))) + /* We already checked these parameters when the template was + declared, so there's no need to do it again now. This function + was defined in class scope, but we're processing its body now + that the class is complete. */ + return true; + + /* Core issue 226 (C++0x only): the following only applies to class + templates. */ + if (is_primary + && ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)) + { + /* [temp.param] + + If a template-parameter has a default template-argument, all + subsequent template-parameters shall have a default + template-argument supplied. */ + for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level)) + { + tree inner_parms = TREE_VALUE (parm_level); + int ntparms = TREE_VEC_LENGTH (inner_parms); + int seen_def_arg_p = 0; + int i; + + for (i = 0; i < ntparms; ++i) + { + tree parm = TREE_VEC_ELT (inner_parms, i); + + if (parm == error_mark_node) + continue; + + if (TREE_PURPOSE (parm)) + seen_def_arg_p = 1; + else if (seen_def_arg_p + && !template_parameter_pack_p (TREE_VALUE (parm))) + { + error ("no default argument for %qD", TREE_VALUE (parm)); + /* For better subsequent error-recovery, we indicate that + there should have been a default argument. */ + TREE_PURPOSE (parm) = error_mark_node; + no_errors = false; + } + else if (!is_partial + && !is_friend_decl + /* Don't complain about an enclosing partial + specialization. */ + && parm_level == parms + && TREE_CODE (decl) == TYPE_DECL + && i < ntparms - 1 + && template_parameter_pack_p (TREE_VALUE (parm)) + /* A fixed parameter pack will be partially + instantiated into a fixed length list. */ + && !fixed_parameter_pack_p (TREE_VALUE (parm))) + { + /* A primary class template can only have one + parameter pack, at the end of the template + parameter list. */ + + if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL) + error ("parameter pack %qE must be at the end of the" + " template parameter list", TREE_VALUE (parm)); + else + error ("parameter pack %qT must be at the end of the" + " template parameter list", + TREE_TYPE (TREE_VALUE (parm))); + + TREE_VALUE (TREE_VEC_ELT (inner_parms, i)) + = error_mark_node; + no_errors = false; + } + } + } + } + + if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL) + || is_partial + || !is_primary + || is_friend_decl) + /* For an ordinary class template, default template arguments are + allowed at the innermost level, e.g.: + template <class T = int> + struct S {}; + but, in a partial specialization, they're not allowed even + there, as we have in [temp.class.spec]: + + The template parameter list of a specialization shall not + contain default template argument values. + + So, for a partial specialization, or for a function template + (in C++98/C++03), we look at all of them. */ + ; + else + /* But, for a primary class template that is not a partial + specialization we look at all template parameters except the + innermost ones. */ + parms = TREE_CHAIN (parms); + + /* Figure out what error message to issue. */ + if (is_friend_decl == 2) + msg = G_("default template arguments may not be used in function template " + "friend re-declaration"); + else if (is_friend_decl) + msg = G_("default template arguments may not be used in function template " + "friend declarations"); + else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98)) + msg = G_("default template arguments may not be used in function templates " + "without -std=c++11 or -std=gnu++11"); + else if (is_partial) + msg = G_("default template arguments may not be used in " + "partial specializations"); + else + msg = G_("default argument for template parameter for class enclosing %qD"); + + if (current_class_type && TYPE_BEING_DEFINED (current_class_type)) + /* If we're inside a class definition, there's no need to + examine the parameters to the class itself. On the one + hand, they will be checked when the class is defined, and, + on the other, default arguments are valid in things like: + template <class T = double> + struct S { template <class U> void f(U); }; + Here the default argument for `S' has no bearing on the + declaration of `f'. */ + last_level_to_check = template_class_depth (current_class_type) + 1; + else + /* Check everything. */ + last_level_to_check = 0; + + for (parm_level = parms; + parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check; + parm_level = TREE_CHAIN (parm_level)) + { + tree inner_parms = TREE_VALUE (parm_level); + int i; + int ntparms; + + ntparms = TREE_VEC_LENGTH (inner_parms); + for (i = 0; i < ntparms; ++i) + { + if (TREE_VEC_ELT (inner_parms, i) == error_mark_node) + continue; + + if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i))) + { + if (msg) + { + no_errors = false; + if (is_friend_decl == 2) + return no_errors; + + error (msg, decl); + msg = 0; + } + + /* Clear out the default argument so that we are not + confused later. */ + TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE; + } + } + + /* At this point, if we're still interested in issuing messages, + they must apply to classes surrounding the object declared. */ + if (msg) + msg = G_("default argument for template parameter for class " + "enclosing %qD"); + } + + return no_errors; +} + +/* Worker for push_template_decl_real, called via + for_each_template_parm. DATA is really an int, indicating the + level of the parameters we are interested in. If T is a template + parameter of that level, return nonzero. */ + +static int +template_parm_this_level_p (tree t, void* data) +{ + int this_level = *(int *)data; + int level; + + if (TREE_CODE (t) == TEMPLATE_PARM_INDEX) + level = TEMPLATE_PARM_LEVEL (t); + else + level = TEMPLATE_TYPE_LEVEL (t); + return level == this_level; +} + +/* Creates a TEMPLATE_DECL for the indicated DECL using the template + parameters given by current_template_args, or reuses a + previously existing one, if appropriate. Returns the DECL, or an + equivalent one, if it is replaced via a call to duplicate_decls. + + If IS_FRIEND is true, DECL is a friend declaration. */ + +tree +push_template_decl_real (tree decl, bool is_friend) +{ + tree tmpl; + tree args; + tree info; + tree ctx; + bool is_primary; + bool is_partial; + int new_template_p = 0; + /* True if the template is a member template, in the sense of + [temp.mem]. */ + bool member_template_p = false; + + if (decl == error_mark_node || !current_template_parms) + return error_mark_node; + + /* See if this is a partial specialization. */ + is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl) + && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE + && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl))); + + if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl)) + is_friend = true; + + if (is_friend) + /* For a friend, we want the context of the friend function, not + the type of which it is a friend. */ + ctx = CP_DECL_CONTEXT (decl); + else if (CP_DECL_CONTEXT (decl) + && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL) + /* In the case of a virtual function, we want the class in which + it is defined. */ + ctx = CP_DECL_CONTEXT (decl); + else + /* Otherwise, if we're currently defining some class, the DECL + is assumed to be a member of the class. */ + ctx = current_scope (); + + if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL) + ctx = NULL_TREE; + + if (!DECL_CONTEXT (decl)) + DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace); + + /* See if this is a primary template. */ + if (is_friend && ctx + && uses_template_parms_level (ctx, processing_template_decl)) + /* A friend template that specifies a class context, i.e. + template <typename T> friend void A<T>::f(); + is not primary. */ + is_primary = false; + else + is_primary = template_parm_scope_p (); + + if (is_primary) + { + if (DECL_CLASS_SCOPE_P (decl)) + member_template_p = true; + if (TREE_CODE (decl) == TYPE_DECL + && ANON_AGGRNAME_P (DECL_NAME (decl))) + { + error ("template class without a name"); + return error_mark_node; + } + else if (TREE_CODE (decl) == FUNCTION_DECL) + { + if (DECL_DESTRUCTOR_P (decl)) + { + /* [temp.mem] + + A destructor shall not be a member template. */ + error ("destructor %qD declared as member template", decl); + return error_mark_node; + } + if (NEW_DELETE_OPNAME_P (DECL_NAME (decl)) + && (!prototype_p (TREE_TYPE (decl)) + || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node + || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl))) + || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl)))) + == void_list_node))) + { + /* [basic.stc.dynamic.allocation] + + An allocation function can be a function + template. ... Template allocation functions shall + have two or more parameters. */ + error ("invalid template declaration of %qD", decl); + return error_mark_node; + } + } + else if (DECL_IMPLICIT_TYPEDEF_P (decl) + && CLASS_TYPE_P (TREE_TYPE (decl))) + /* OK */; + else if (TREE_CODE (decl) == TYPE_DECL + && TYPE_DECL_ALIAS_P (decl)) + /* alias-declaration */ + gcc_assert (!DECL_ARTIFICIAL (decl)); + else + { + error ("template declaration of %q#D", decl); + return error_mark_node; + } + } + + /* Check to see that the rules regarding the use of default + arguments are not being violated. */ + check_default_tmpl_args (decl, current_template_parms, + is_primary, is_partial, /*is_friend_decl=*/0); + + /* Ensure that there are no parameter packs in the type of this + declaration that have not been expanded. */ + if (TREE_CODE (decl) == FUNCTION_DECL) + { + /* Check each of the arguments individually to see if there are + any bare parameter packs. */ + tree type = TREE_TYPE (decl); + tree arg = DECL_ARGUMENTS (decl); + tree argtype = TYPE_ARG_TYPES (type); + + while (arg && argtype) + { + if (!DECL_PACK_P (arg) + && check_for_bare_parameter_packs (TREE_TYPE (arg))) + { + /* This is a PARM_DECL that contains unexpanded parameter + packs. We have already complained about this in the + check_for_bare_parameter_packs call, so just replace + these types with ERROR_MARK_NODE. */ + TREE_TYPE (arg) = error_mark_node; + TREE_VALUE (argtype) = error_mark_node; + } + + arg = DECL_CHAIN (arg); + argtype = TREE_CHAIN (argtype); + } + + /* Check for bare parameter packs in the return type and the + exception specifiers. */ + if (check_for_bare_parameter_packs (TREE_TYPE (type))) + /* Errors were already issued, set return type to int + as the frontend doesn't expect error_mark_node as + the return type. */ + TREE_TYPE (type) = integer_type_node; + if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type))) + TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE; + } + else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL + && TYPE_DECL_ALIAS_P (decl)) + ? DECL_ORIGINAL_TYPE (decl) + : TREE_TYPE (decl))) + { + TREE_TYPE (decl) = error_mark_node; + return error_mark_node; + } + + if (is_partial) + return process_partial_specialization (decl); + + args = current_template_args (); + + if (!ctx + || TREE_CODE (ctx) == FUNCTION_DECL + || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx)) + || (TREE_CODE (decl) == TYPE_DECL + && LAMBDA_TYPE_P (TREE_TYPE (decl))) + || (is_friend && !DECL_TEMPLATE_INFO (decl))) + { + if (DECL_LANG_SPECIFIC (decl) + && DECL_TEMPLATE_INFO (decl) + && DECL_TI_TEMPLATE (decl)) + tmpl = DECL_TI_TEMPLATE (decl); + /* If DECL is a TYPE_DECL for a class-template, then there won't + be DECL_LANG_SPECIFIC. The information equivalent to + DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */ + else if (DECL_IMPLICIT_TYPEDEF_P (decl) + && TYPE_TEMPLATE_INFO (TREE_TYPE (decl)) + && TYPE_TI_TEMPLATE (TREE_TYPE (decl))) + { + /* Since a template declaration already existed for this + class-type, we must be redeclaring it here. Make sure + that the redeclaration is valid. */ + redeclare_class_template (TREE_TYPE (decl), + current_template_parms); + /* We don't need to create a new TEMPLATE_DECL; just use the + one we already had. */ + tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl)); + } + else + { + tmpl = build_template_decl (decl, current_template_parms, + member_template_p); + new_template_p = 1; + + if (DECL_LANG_SPECIFIC (decl) + && DECL_TEMPLATE_SPECIALIZATION (decl)) + { + /* A specialization of a member template of a template + class. */ + SET_DECL_TEMPLATE_SPECIALIZATION (tmpl); + DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl); + DECL_TEMPLATE_INFO (decl) = NULL_TREE; + } + } + } + else + { + tree a, t, current, parms; + int i; + tree tinfo = get_template_info (decl); + + if (!tinfo) + { + error ("template definition of non-template %q#D", decl); + return error_mark_node; + } + + tmpl = TI_TEMPLATE (tinfo); + + if (DECL_FUNCTION_TEMPLATE_P (tmpl) + && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl) + && DECL_TEMPLATE_SPECIALIZATION (decl) + && DECL_MEMBER_TEMPLATE_P (tmpl)) + { + tree new_tmpl; + + /* The declaration is a specialization of a member + template, declared outside the class. Therefore, the + innermost template arguments will be NULL, so we + replace them with the arguments determined by the + earlier call to check_explicit_specialization. */ + args = DECL_TI_ARGS (decl); + + new_tmpl + = build_template_decl (decl, current_template_parms, + member_template_p); + DECL_TEMPLATE_RESULT (new_tmpl) = decl; + TREE_TYPE (new_tmpl) = TREE_TYPE (decl); + DECL_TI_TEMPLATE (decl) = new_tmpl; + SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl); + DECL_TEMPLATE_INFO (new_tmpl) + = build_template_info (tmpl, args); + + register_specialization (new_tmpl, + most_general_template (tmpl), + args, + is_friend, 0); + return decl; + } + + /* Make sure the template headers we got make sense. */ + + parms = DECL_TEMPLATE_PARMS (tmpl); + i = TMPL_PARMS_DEPTH (parms); + if (TMPL_ARGS_DEPTH (args) != i) + { + error ("expected %d levels of template parms for %q#D, got %d", + i, decl, TMPL_ARGS_DEPTH (args)); + DECL_INTERFACE_KNOWN (decl) = 1; + return error_mark_node; + } + else + for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms)) + { + a = TMPL_ARGS_LEVEL (args, i); + t = INNERMOST_TEMPLATE_PARMS (parms); + + if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a)) + { + if (current == decl) + error ("got %d template parameters for %q#D", + TREE_VEC_LENGTH (a), decl); + else + error ("got %d template parameters for %q#T", + TREE_VEC_LENGTH (a), current); + error (" but %d required", TREE_VEC_LENGTH (t)); + /* Avoid crash in import_export_decl. */ + DECL_INTERFACE_KNOWN (decl) = 1; + return error_mark_node; + } + + if (current == decl) + current = ctx; + else if (current == NULL_TREE) + /* Can happen in erroneous input. */ + break; + else + current = get_containing_scope (current); + } + + /* Check that the parms are used in the appropriate qualifying scopes + in the declarator. */ + if (!comp_template_args + (TI_ARGS (tinfo), + TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl))))) + { + error ("\ +template arguments to %qD do not match original template %qD", + decl, DECL_TEMPLATE_RESULT (tmpl)); + if (!uses_template_parms (TI_ARGS (tinfo))) + inform (input_location, "use template<> for an explicit specialization"); + /* Avoid crash in import_export_decl. */ + DECL_INTERFACE_KNOWN (decl) = 1; + return error_mark_node; + } + } + + DECL_TEMPLATE_RESULT (tmpl) = decl; + TREE_TYPE (tmpl) = TREE_TYPE (decl); + + /* Push template declarations for global functions and types. Note + that we do not try to push a global template friend declared in a + template class; such a thing may well depend on the template + parameters of the class. */ + if (new_template_p && !ctx + && !(is_friend && template_class_depth (current_class_type) > 0)) + { + tmpl = pushdecl_namespace_level (tmpl, is_friend); + if (tmpl == error_mark_node) + return error_mark_node; + + /* Hide template friend classes that haven't been declared yet. */ + if (is_friend && TREE_CODE (decl) == TYPE_DECL) + { + DECL_ANTICIPATED (tmpl) = 1; + DECL_FRIEND_P (tmpl) = 1; + } + } + + if (is_primary) + { + tree parms = DECL_TEMPLATE_PARMS (tmpl); + int i; + + DECL_PRIMARY_TEMPLATE (tmpl) = tmpl; + if (DECL_CONV_FN_P (tmpl)) + { + int depth = TMPL_PARMS_DEPTH (parms); + + /* It is a conversion operator. See if the type converted to + depends on innermost template operands. */ + + if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)), + depth)) + DECL_TEMPLATE_CONV_FN_P (tmpl) = 1; + } + + /* Give template template parms a DECL_CONTEXT of the template + for which they are a parameter. */ + parms = INNERMOST_TEMPLATE_PARMS (parms); + for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i) + { + tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i)); + if (TREE_CODE (parm) == TEMPLATE_DECL) + DECL_CONTEXT (parm) = tmpl; + } + } + + /* The DECL_TI_ARGS of DECL contains full set of arguments referring + back to its most general template. If TMPL is a specialization, + ARGS may only have the innermost set of arguments. Add the missing + argument levels if necessary. */ + if (DECL_TEMPLATE_INFO (tmpl)) + args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args); + + info = build_template_info (tmpl, args); + + if (DECL_IMPLICIT_TYPEDEF_P (decl)) + SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info); + else + { + if (is_primary && !DECL_LANG_SPECIFIC (decl)) + retrofit_lang_decl (decl); + if (DECL_LANG_SPECIFIC (decl)) + DECL_TEMPLATE_INFO (decl) = info; + } + + return DECL_TEMPLATE_RESULT (tmpl); +} + +tree +push_template_decl (tree decl) +{ + return push_template_decl_real (decl, false); +} + +/* FN is an inheriting constructor that inherits from the constructor + template INHERITED; turn FN into a constructor template with a matching + template header. */ + +tree +add_inherited_template_parms (tree fn, tree inherited) +{ + tree inner_parms + = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (inherited)); + inner_parms = copy_node (inner_parms); + tree parms + = tree_cons (size_int (processing_template_decl + 1), + inner_parms, current_template_parms); + tree tmpl = build_template_decl (fn, parms, /*member*/true); + tree args = template_parms_to_args (parms); + DECL_TEMPLATE_INFO (fn) = build_template_info (tmpl, args); + TREE_TYPE (tmpl) = TREE_TYPE (fn); + DECL_TEMPLATE_RESULT (tmpl) = fn; + DECL_ARTIFICIAL (tmpl) = true; + DECL_PRIMARY_TEMPLATE (tmpl) = tmpl; + return tmpl; +} + +/* Called when a class template TYPE is redeclared with the indicated + template PARMS, e.g.: + + template <class T> struct S; + template <class T> struct S {}; */ + +bool +redeclare_class_template (tree type, tree parms) +{ + tree tmpl; + tree tmpl_parms; + int i; + + if (!TYPE_TEMPLATE_INFO (type)) + { + error ("%qT is not a template type", type); + return false; + } + + tmpl = TYPE_TI_TEMPLATE (type); + if (!PRIMARY_TEMPLATE_P (tmpl)) + /* The type is nested in some template class. Nothing to worry + about here; there are no new template parameters for the nested + type. */ + return true; + + if (!parms) + { + error ("template specifiers not specified in declaration of %qD", + tmpl); + return false; + } + + parms = INNERMOST_TEMPLATE_PARMS (parms); + tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl); + + if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms)) + { + error_n (input_location, TREE_VEC_LENGTH (parms), + "redeclared with %d template parameter", + "redeclared with %d template parameters", + TREE_VEC_LENGTH (parms)); + inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms), + "previous declaration %q+D used %d template parameter", + "previous declaration %q+D used %d template parameters", + tmpl, TREE_VEC_LENGTH (tmpl_parms)); + return false; + } + + for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i) + { + tree tmpl_parm; + tree parm; + tree tmpl_default; + tree parm_default; + + if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node + || TREE_VEC_ELT (parms, i) == error_mark_node) + continue; + + tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i)); + if (tmpl_parm == error_mark_node) + return false; + + parm = TREE_VALUE (TREE_VEC_ELT (parms, i)); + tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)); + parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i)); + + /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or + TEMPLATE_DECL. */ + if (TREE_CODE (tmpl_parm) != TREE_CODE (parm) + || (TREE_CODE (tmpl_parm) != TYPE_DECL + && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm))) + || (TREE_CODE (tmpl_parm) != PARM_DECL + && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm)) + != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))) + || (TREE_CODE (tmpl_parm) == PARM_DECL + && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm)) + != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))))) + { + error ("template parameter %q+#D", tmpl_parm); + error ("redeclared here as %q#D", parm); + return false; + } + + if (tmpl_default != NULL_TREE && parm_default != NULL_TREE) + { + /* We have in [temp.param]: + + A template-parameter may not be given default arguments + by two different declarations in the same scope. */ + error_at (input_location, "redefinition of default argument for %q#D", parm); + inform (DECL_SOURCE_LOCATION (tmpl_parm), + "original definition appeared here"); + return false; + } + + if (parm_default != NULL_TREE) + /* Update the previous template parameters (which are the ones + that will really count) with the new default value. */ + TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default; + else if (tmpl_default != NULL_TREE) + /* Update the new parameters, too; they'll be used as the + parameters for any members. */ + TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default; + } + + return true; +} + +/* Simplify EXPR if it is a non-dependent expression. Returns the + (possibly simplified) expression. */ + +tree +fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain) +{ + if (expr == NULL_TREE) + return NULL_TREE; + + /* If we're in a template, but EXPR isn't value dependent, simplify + it. We're supposed to treat: + + template <typename T> void f(T[1 + 1]); + template <typename T> void f(T[2]); + + as two declarations of the same function, for example. */ + if (processing_template_decl + && !instantiation_dependent_expression_p (expr) + && potential_constant_expression (expr)) + { + HOST_WIDE_INT saved_processing_template_decl; + + saved_processing_template_decl = processing_template_decl; + processing_template_decl = 0; + expr = tsubst_copy_and_build (expr, + /*args=*/NULL_TREE, + complain, + /*in_decl=*/NULL_TREE, + /*function_p=*/false, + /*integral_constant_expression_p=*/true); + processing_template_decl = saved_processing_template_decl; + } + return expr; +} + +tree +fold_non_dependent_expr (tree expr) +{ + return fold_non_dependent_expr_sfinae (expr, tf_error); +} + +/* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias + template declaration, or a TYPE_DECL for an alias declaration. */ + +bool +alias_type_or_template_p (tree t) +{ + if (t == NULL_TREE) + return false; + return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t)) + || (TYPE_P (t) + && TYPE_NAME (t) + && TYPE_DECL_ALIAS_P (TYPE_NAME (t))) + || DECL_ALIAS_TEMPLATE_P (t)); +} + +/* Return TRUE iff is a specialization of an alias template. */ + +bool +alias_template_specialization_p (const_tree t) +{ + if (t == NULL_TREE) + return false; + + return (TYPE_P (t) + && TYPE_TEMPLATE_INFO (t) + && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t)) + && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t))); +} + +/* Return the number of innermost template parameters in TMPL. */ + +static int +num_innermost_template_parms (tree tmpl) +{ + tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (tmpl)); + return TREE_VEC_LENGTH (parms); +} + +/* Return either TMPL or another template that it is equivalent to under DR + 1286: An alias that just changes the name of a template is equivalent to + the other template. */ + +static tree +get_underlying_template (tree tmpl) +{ + gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL); + while (DECL_ALIAS_TEMPLATE_P (tmpl)) + { + tree result = DECL_ORIGINAL_TYPE (DECL_TEMPLATE_RESULT (tmpl)); + if (TYPE_TEMPLATE_INFO (result)) + { + tree sub = TYPE_TI_TEMPLATE (result); + if (PRIMARY_TEMPLATE_P (sub) + && (num_innermost_template_parms (tmpl) + == num_innermost_template_parms (sub))) + { + tree alias_args = INNERMOST_TEMPLATE_ARGS + (template_parms_to_args (DECL_TEMPLATE_PARMS (tmpl))); + if (!comp_template_args (TYPE_TI_ARGS (result), alias_args)) + break; + /* The alias type is equivalent to the pattern of the + underlying template, so strip the alias. */ + tmpl = sub; + continue; + } + } + break; + } + return tmpl; +} + +/* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which + must be a function or a pointer-to-function type, as specified + in [temp.arg.nontype]: disambiguate EXPR if it is an overload set, + and check that the resulting function has external linkage. */ + +static tree +convert_nontype_argument_function (tree type, tree expr) +{ + tree fns = expr; + tree fn, fn_no_ptr; + linkage_kind linkage; + + fn = instantiate_type (type, fns, tf_none); + if (fn == error_mark_node) + return error_mark_node; + + fn_no_ptr = fn; + if (TREE_CODE (fn_no_ptr) == ADDR_EXPR) + fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0); + if (BASELINK_P (fn_no_ptr)) + fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr); + + /* [temp.arg.nontype]/1 + + A template-argument for a non-type, non-template template-parameter + shall be one of: + [...] + -- the address of an object or function with external [C++11: or + internal] linkage. */ + + if (TREE_CODE (fn_no_ptr) != FUNCTION_DECL) + { + error ("%qE is not a valid template argument for type %qT", expr, type); + if (TYPE_PTR_P (type)) + error ("it must be the address of a function with external linkage"); + else + error ("it must be the name of a function with external linkage"); + return NULL_TREE; + } + + linkage = decl_linkage (fn_no_ptr); + if (cxx_dialect >= cxx11 ? linkage == lk_none : linkage != lk_external) + { + if (cxx_dialect >= cxx11) + error ("%qE is not a valid template argument for type %qT " + "because %qD has no linkage", + expr, type, fn_no_ptr); + else + error ("%qE is not a valid template argument for type %qT " + "because %qD does not have external linkage", + expr, type, fn_no_ptr); + return NULL_TREE; + } + + return fn; +} + +/* Subroutine of convert_nontype_argument. + Check if EXPR of type TYPE is a valid pointer-to-member constant. + Emit an error otherwise. */ + +static bool +check_valid_ptrmem_cst_expr (tree type, tree expr, + tsubst_flags_t complain) +{ + STRIP_NOPS (expr); + if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST)) + return true; + if (cxx_dialect >= cxx11 && null_member_pointer_value_p (expr)) + return true; + if (complain & tf_error) + { + error ("%qE is not a valid template argument for type %qT", + expr, type); + error ("it must be a pointer-to-member of the form %<&X::Y%>"); + } + return false; +} + +/* Returns TRUE iff the address of OP is value-dependent. + + 14.6.2.4 [temp.dep.temp]: + A non-integral non-type template-argument is dependent if its type is + dependent or it has either of the following forms + qualified-id + & qualified-id + and contains a nested-name-specifier which specifies a class-name that + names a dependent type. + + We generalize this to just say that the address of a member of a + dependent class is value-dependent; the above doesn't cover the + address of a static data member named with an unqualified-id. */ + +static bool +has_value_dependent_address (tree op) +{ + /* We could use get_inner_reference here, but there's no need; + this is only relevant for template non-type arguments, which + can only be expressed as &id-expression. */ + if (DECL_P (op)) + { + tree ctx = CP_DECL_CONTEXT (op); + if (TYPE_P (ctx) && dependent_type_p (ctx)) + return true; + } + + return false; +} + +/* The next set of functions are used for providing helpful explanatory + diagnostics for failed overload resolution. Their messages should be + indented by two spaces for consistency with the messages in + call.c */ + +static int +unify_success (bool /*explain_p*/) +{ + return 0; +} + +static int +unify_parameter_deduction_failure (bool explain_p, tree parm) +{ + if (explain_p) + inform (input_location, + " couldn't deduce template parameter %qD", parm); + return 1; +} + +static int +unify_invalid (bool /*explain_p*/) +{ + return 1; +} + +static int +unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg) +{ + if (explain_p) + inform (input_location, + " types %qT and %qT have incompatible cv-qualifiers", + parm, arg); + return 1; +} + +static int +unify_type_mismatch (bool explain_p, tree parm, tree arg) +{ + if (explain_p) + inform (input_location, " mismatched types %qT and %qT", parm, arg); + return 1; +} + +static int +unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg) +{ + if (explain_p) + inform (input_location, + " template parameter %qD is not a parameter pack, but " + "argument %qD is", + parm, arg); + return 1; +} + +static int +unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg) +{ + if (explain_p) + inform (input_location, + " template argument %qE does not match " + "pointer-to-member constant %qE", + arg, parm); + return 1; +} + +static int +unify_expression_unequal (bool explain_p, tree parm, tree arg) +{ + if (explain_p) + inform (input_location, " %qE is not equivalent to %qE", parm, arg); + return 1; +} + +static int +unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg) +{ + if (explain_p) + inform (input_location, + " inconsistent parameter pack deduction with %qT and %qT", + old_arg, new_arg); + return 1; +} + +static int +unify_inconsistency (bool explain_p, tree parm, tree first, tree second) +{ + if (explain_p) + { + if (TYPE_P (parm)) + inform (input_location, + " deduced conflicting types for parameter %qT (%qT and %qT)", + parm, first, second); + else + inform (input_location, + " deduced conflicting values for non-type parameter " + "%qE (%qE and %qE)", parm, first, second); + } + return 1; +} + +static int +unify_vla_arg (bool explain_p, tree arg) +{ + if (explain_p) + inform (input_location, + " variable-sized array type %qT is not " + "a valid template argument", + arg); + return 1; +} + +static int +unify_method_type_error (bool explain_p, tree arg) +{ + if (explain_p) + inform (input_location, + " member function type %qT is not a valid template argument", + arg); + return 1; +} + +static int +unify_arity (bool explain_p, int have, int wanted) +{ + if (explain_p) + inform_n (input_location, wanted, + " candidate expects %d argument, %d provided", + " candidate expects %d arguments, %d provided", + wanted, have); + return 1; +} + +static int +unify_too_many_arguments (bool explain_p, int have, int wanted) +{ + return unify_arity (explain_p, have, wanted); +} + +static int +unify_too_few_arguments (bool explain_p, int have, int wanted) +{ + return unify_arity (explain_p, have, wanted); +} + +static int +unify_arg_conversion (bool explain_p, tree to_type, + tree from_type, tree arg) +{ + if (explain_p) + inform (EXPR_LOC_OR_LOC (arg, input_location), + " cannot convert %qE (type %qT) to type %qT", + arg, from_type, to_type); + return 1; +} + +static int +unify_no_common_base (bool explain_p, enum template_base_result r, + tree parm, tree arg) +{ + if (explain_p) + switch (r) + { + case tbr_ambiguous_baseclass: + inform (input_location, " %qT is an ambiguous base class of %qT", + parm, arg); + break; + default: + inform (input_location, " %qT is not derived from %qT", arg, parm); + break; + } + return 1; +} + +static int +unify_inconsistent_template_template_parameters (bool explain_p) +{ + if (explain_p) + inform (input_location, + " template parameters of a template template argument are " + "inconsistent with other deduced template arguments"); + return 1; +} + +static int +unify_template_deduction_failure (bool explain_p, tree parm, tree arg) +{ + if (explain_p) + inform (input_location, + " can't deduce a template for %qT from non-template type %qT", + parm, arg); + return 1; +} + +static int +unify_template_argument_mismatch (bool explain_p, tree parm, tree arg) +{ + if (explain_p) + inform (input_location, + " template argument %qE does not match %qD", arg, parm); + return 1; +} + +static int +unify_overload_resolution_failure (bool explain_p, tree arg) +{ + if (explain_p) + inform (input_location, + " could not resolve address from overloaded function %qE", + arg); + return 1; +} + +/* Attempt to convert the non-type template parameter EXPR to the + indicated TYPE. If the conversion is successful, return the + converted value. If the conversion is unsuccessful, return + NULL_TREE if we issued an error message, or error_mark_node if we + did not. We issue error messages for out-and-out bad template + parameters, but not simply because the conversion failed, since we + might be just trying to do argument deduction. Both TYPE and EXPR + must be non-dependent. + + The conversion follows the special rules described in + [temp.arg.nontype], and it is much more strict than an implicit + conversion. + + This function is called twice for each template argument (see + lookup_template_class for a more accurate description of this + problem). This means that we need to handle expressions which + are not valid in a C++ source, but can be created from the + first call (for instance, casts to perform conversions). These + hacks can go away after we fix the double coercion problem. */ + +static tree +convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain) +{ + tree expr_type; + + /* Detect immediately string literals as invalid non-type argument. + This special-case is not needed for correctness (we would easily + catch this later), but only to provide better diagnostic for this + common user mistake. As suggested by DR 100, we do not mention + linkage issues in the diagnostic as this is not the point. */ + /* FIXME we're making this OK. */ + if (TREE_CODE (expr) == STRING_CST) + { + if (complain & tf_error) + error ("%qE is not a valid template argument for type %qT " + "because string literals can never be used in this context", + expr, type); + return NULL_TREE; + } + + /* Add the ADDR_EXPR now for the benefit of + value_dependent_expression_p. */ + if (TYPE_PTROBV_P (type) + && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE) + { + expr = decay_conversion (expr, complain); + if (expr == error_mark_node) + return error_mark_node; + } + + /* If we are in a template, EXPR may be non-dependent, but still + have a syntactic, rather than semantic, form. For example, EXPR + might be a SCOPE_REF, rather than the VAR_DECL to which the + SCOPE_REF refers. Preserving the qualifying scope is necessary + so that access checking can be performed when the template is + instantiated -- but here we need the resolved form so that we can + convert the argument. */ + if (TYPE_REF_OBJ_P (type) + && has_value_dependent_address (expr)) + /* If we want the address and it's value-dependent, don't fold. */; + else if (!type_unknown_p (expr)) + expr = fold_non_dependent_expr_sfinae (expr, complain); + if (error_operand_p (expr)) + return error_mark_node; + expr_type = TREE_TYPE (expr); + if (TREE_CODE (type) == REFERENCE_TYPE) + expr = mark_lvalue_use (expr); + else + expr = mark_rvalue_use (expr); + + /* 14.3.2/5: The null pointer{,-to-member} conversion is applied + to a non-type argument of "nullptr". */ + if (expr == nullptr_node && TYPE_PTR_OR_PTRMEM_P (type)) + expr = convert (type, expr); + + /* In C++11, integral or enumeration non-type template arguments can be + arbitrary constant expressions. Pointer and pointer to + member arguments can be general constant expressions that evaluate + to a null value, but otherwise still need to be of a specific form. */ + if (cxx_dialect >= cxx11) + { + if (TREE_CODE (expr) == PTRMEM_CST) + /* A PTRMEM_CST is already constant, and a valid template + argument for a parameter of pointer to member type, we just want + to leave it in that form rather than lower it to a + CONSTRUCTOR. */; + else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) + expr = maybe_constant_value (expr); + else if (TYPE_PTR_OR_PTRMEM_P (type)) + { + tree folded = maybe_constant_value (expr); + if (TYPE_PTR_P (type) ? integer_zerop (folded) + : null_member_pointer_value_p (folded)) + expr = folded; + } + } + + /* HACK: Due to double coercion, we can get a + NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here, + which is the tree that we built on the first call (see + below when coercing to reference to object or to reference to + function). We just strip everything and get to the arg. + See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C + for examples. */ + if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type)) + { + tree probe_type, probe = expr; + if (REFERENCE_REF_P (probe)) + probe = TREE_OPERAND (probe, 0); + probe_type = TREE_TYPE (probe); + if (TREE_CODE (probe) == NOP_EXPR) + { + /* ??? Maybe we could use convert_from_reference here, but we + would need to relax its constraints because the NOP_EXPR + could actually change the type to something more cv-qualified, + and this is not folded by convert_from_reference. */ + tree addr = TREE_OPERAND (probe, 0); + if (TREE_CODE (probe_type) == REFERENCE_TYPE + && TREE_CODE (addr) == ADDR_EXPR + && TYPE_PTR_P (TREE_TYPE (addr)) + && (same_type_ignoring_top_level_qualifiers_p + (TREE_TYPE (probe_type), + TREE_TYPE (TREE_TYPE (addr))))) + { + expr = TREE_OPERAND (addr, 0); + expr_type = TREE_TYPE (probe_type); + } + } + } + + /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the + parameter is a pointer to object, through decay and + qualification conversion. Let's strip everything. */ + else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type)) + { + tree probe = expr; + STRIP_NOPS (probe); + if (TREE_CODE (probe) == ADDR_EXPR + && TYPE_PTR_P (TREE_TYPE (probe))) + { + /* Skip the ADDR_EXPR only if it is part of the decay for + an array. Otherwise, it is part of the original argument + in the source code. */ + if (TREE_CODE (TREE_TYPE (TREE_OPERAND (probe, 0))) == ARRAY_TYPE) + probe = TREE_OPERAND (probe, 0); + expr = probe; + expr_type = TREE_TYPE (expr); + } + } + + /* [temp.arg.nontype]/5, bullet 1 + + For a non-type template-parameter of integral or enumeration type, + integral promotions (_conv.prom_) and integral conversions + (_conv.integral_) are applied. */ + if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) + { + tree t = build_integral_nontype_arg_conv (type, expr, complain); + t = maybe_constant_value (t); + if (t != error_mark_node) + expr = t; + + if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr))) + return error_mark_node; + + /* Notice that there are constant expressions like '4 % 0' which + do not fold into integer constants. */ + if (TREE_CODE (expr) != INTEGER_CST) + { + if (complain & tf_error) + { + int errs = errorcount, warns = warningcount + werrorcount; + if (processing_template_decl + && !require_potential_constant_expression (expr)) + return NULL_TREE; + expr = cxx_constant_value (expr); + if (errorcount > errs || warningcount + werrorcount > warns) + inform (EXPR_LOC_OR_LOC (expr, input_location), + "in template argument for type %qT ", type); + if (expr == error_mark_node) + return NULL_TREE; + /* else cxx_constant_value complained but gave us + a real constant, so go ahead. */ + gcc_assert (TREE_CODE (expr) == INTEGER_CST); + } + else + return NULL_TREE; + } + + /* Avoid typedef problems. */ + if (TREE_TYPE (expr) != type) + expr = fold_convert (type, expr); + } + /* [temp.arg.nontype]/5, bullet 2 + + For a non-type template-parameter of type pointer to object, + qualification conversions (_conv.qual_) and the array-to-pointer + conversion (_conv.array_) are applied. */ + else if (TYPE_PTROBV_P (type)) + { + /* [temp.arg.nontype]/1 (TC1 version, DR 49): + + A template-argument for a non-type, non-template template-parameter + shall be one of: [...] + + -- the name of a non-type template-parameter; + -- the address of an object or function with external linkage, [...] + expressed as "& id-expression" where the & is optional if the name + refers to a function or array, or if the corresponding + template-parameter is a reference. + + Here, we do not care about functions, as they are invalid anyway + for a parameter of type pointer-to-object. */ + + if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr)) + /* Non-type template parameters are OK. */ + ; + else if (cxx_dialect >= cxx11 && integer_zerop (expr)) + /* Null pointer values are OK in C++11. */; + else if (TREE_CODE (expr) != ADDR_EXPR + && TREE_CODE (expr_type) != ARRAY_TYPE) + { + if (VAR_P (expr)) + { + error ("%qD is not a valid template argument " + "because %qD is a variable, not the address of " + "a variable", + expr, expr); + return NULL_TREE; + } + if (POINTER_TYPE_P (expr_type)) + { + error ("%qE is not a valid template argument for %qT " + "because it is not the address of a variable", + expr, type); + return NULL_TREE; + } + /* Other values, like integer constants, might be valid + non-type arguments of some other type. */ + return error_mark_node; + } + else + { + tree decl; + + decl = ((TREE_CODE (expr) == ADDR_EXPR) + ? TREE_OPERAND (expr, 0) : expr); + if (!VAR_P (decl)) + { + error ("%qE is not a valid template argument of type %qT " + "because %qE is not a variable", + expr, type, decl); + return NULL_TREE; + } + else if (cxx_dialect < cxx11 && !DECL_EXTERNAL_LINKAGE_P (decl)) + { + error ("%qE is not a valid template argument of type %qT " + "because %qD does not have external linkage", + expr, type, decl); + return NULL_TREE; + } + else if (cxx_dialect >= cxx11 && decl_linkage (decl) == lk_none) + { + error ("%qE is not a valid template argument of type %qT " + "because %qD has no linkage", + expr, type, decl); + return NULL_TREE; + } + } + + expr = decay_conversion (expr, complain); + if (expr == error_mark_node) + return error_mark_node; + + expr = perform_qualification_conversions (type, expr); + if (expr == error_mark_node) + return error_mark_node; + } + /* [temp.arg.nontype]/5, bullet 3 + + For a non-type template-parameter of type reference to object, no + conversions apply. The type referred to by the reference may be more + cv-qualified than the (otherwise identical) type of the + template-argument. The template-parameter is bound directly to the + template-argument, which must be an lvalue. */ + else if (TYPE_REF_OBJ_P (type)) + { + if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type), + expr_type)) + return error_mark_node; + + if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type)) + { + error ("%qE is not a valid template argument for type %qT " + "because of conflicts in cv-qualification", expr, type); + return NULL_TREE; + } + + if (!real_lvalue_p (expr)) + { + error ("%qE is not a valid template argument for type %qT " + "because it is not an lvalue", expr, type); + return NULL_TREE; + } + + /* [temp.arg.nontype]/1 + + A template-argument for a non-type, non-template template-parameter + shall be one of: [...] + + -- the address of an object or function with external linkage. */ + if (INDIRECT_REF_P (expr) + && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0)))) + { + expr = TREE_OPERAND (expr, 0); + if (DECL_P (expr)) + { + error ("%q#D is not a valid template argument for type %qT " + "because a reference variable does not have a constant " + "address", expr, type); + return NULL_TREE; + } + } + + if (!DECL_P (expr)) + { + error ("%qE is not a valid template argument for type %qT " + "because it is not an object with external linkage", + expr, type); + return NULL_TREE; + } + + if (!DECL_EXTERNAL_LINKAGE_P (expr)) + { + error ("%qE is not a valid template argument for type %qT " + "because object %qD has not external linkage", + expr, type, expr); + return NULL_TREE; + } + + expr = build_nop (type, build_address (expr)); + } + /* [temp.arg.nontype]/5, bullet 4 + + For a non-type template-parameter of type pointer to function, only + the function-to-pointer conversion (_conv.func_) is applied. If the + template-argument represents a set of overloaded functions (or a + pointer to such), the matching function is selected from the set + (_over.over_). */ + else if (TYPE_PTRFN_P (type)) + { + /* If the argument is a template-id, we might not have enough + context information to decay the pointer. */ + if (!type_unknown_p (expr_type)) + { + expr = decay_conversion (expr, complain); + if (expr == error_mark_node) + return error_mark_node; + } + + if (cxx_dialect >= cxx11 && integer_zerop (expr)) + /* Null pointer values are OK in C++11. */ + return perform_qualification_conversions (type, expr); + + expr = convert_nontype_argument_function (type, expr); + if (!expr || expr == error_mark_node) + return expr; + } + /* [temp.arg.nontype]/5, bullet 5 + + For a non-type template-parameter of type reference to function, no + conversions apply. If the template-argument represents a set of + overloaded functions, the matching function is selected from the set + (_over.over_). */ + else if (TYPE_REFFN_P (type)) + { + if (TREE_CODE (expr) == ADDR_EXPR) + { + error ("%qE is not a valid template argument for type %qT " + "because it is a pointer", expr, type); + inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0)); + return NULL_TREE; + } + + expr = convert_nontype_argument_function (type, expr); + if (!expr || expr == error_mark_node) + return expr; + + expr = build_nop (type, build_address (expr)); + } + /* [temp.arg.nontype]/5, bullet 6 + + For a non-type template-parameter of type pointer to member function, + no conversions apply. If the template-argument represents a set of + overloaded member functions, the matching member function is selected + from the set (_over.over_). */ + else if (TYPE_PTRMEMFUNC_P (type)) + { + expr = instantiate_type (type, expr, tf_none); + if (expr == error_mark_node) + return error_mark_node; + + /* [temp.arg.nontype] bullet 1 says the pointer to member + expression must be a pointer-to-member constant. */ + if (!check_valid_ptrmem_cst_expr (type, expr, complain)) + return error_mark_node; + + /* There is no way to disable standard conversions in + resolve_address_of_overloaded_function (called by + instantiate_type). It is possible that the call succeeded by + converting &B::I to &D::I (where B is a base of D), so we need + to reject this conversion here. + + Actually, even if there was a way to disable standard conversions, + it would still be better to reject them here so that we can + provide a superior diagnostic. */ + if (!same_type_p (TREE_TYPE (expr), type)) + { + error ("%qE is not a valid template argument for type %qT " + "because it is of type %qT", expr, type, + TREE_TYPE (expr)); + /* If we are just one standard conversion off, explain. */ + if (can_convert_standard (type, TREE_TYPE (expr), complain)) + inform (input_location, + "standard conversions are not allowed in this context"); + return NULL_TREE; + } + } + /* [temp.arg.nontype]/5, bullet 7 + + For a non-type template-parameter of type pointer to data member, + qualification conversions (_conv.qual_) are applied. */ + else if (TYPE_PTRDATAMEM_P (type)) + { + /* [temp.arg.nontype] bullet 1 says the pointer to member + expression must be a pointer-to-member constant. */ + if (!check_valid_ptrmem_cst_expr (type, expr, complain)) + return error_mark_node; + + expr = perform_qualification_conversions (type, expr); + if (expr == error_mark_node) + return expr; + } + else if (NULLPTR_TYPE_P (type)) + { + if (expr != nullptr_node) + { + error ("%qE is not a valid template argument for type %qT " + "because it is of type %qT", expr, type, TREE_TYPE (expr)); + return NULL_TREE; + } + return expr; + } + /* A template non-type parameter must be one of the above. */ + else + gcc_unreachable (); + + /* Sanity check: did we actually convert the argument to the + right type? */ + gcc_assert (same_type_ignoring_top_level_qualifiers_p + (type, TREE_TYPE (expr))); + return expr; +} + +/* Subroutine of coerce_template_template_parms, which returns 1 if + PARM_PARM and ARG_PARM match using the rule for the template + parameters of template template parameters. Both PARM and ARG are + template parameters; the rest of the arguments are the same as for + coerce_template_template_parms. + */ +static int +coerce_template_template_parm (tree parm, + tree arg, + tsubst_flags_t complain, + tree in_decl, + tree outer_args) +{ + if (arg == NULL_TREE || arg == error_mark_node + || parm == NULL_TREE || parm == error_mark_node) + return 0; + + if (TREE_CODE (arg) != TREE_CODE (parm)) + return 0; + + switch (TREE_CODE (parm)) + { + case TEMPLATE_DECL: + /* We encounter instantiations of templates like + template <template <template <class> class> class TT> + class C; */ + { + tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm); + tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg); + + if (!coerce_template_template_parms + (parmparm, argparm, complain, in_decl, outer_args)) + return 0; + } + /* Fall through. */ + + case TYPE_DECL: + if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg)) + && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))) + /* Argument is a parameter pack but parameter is not. */ + return 0; + break; + + case PARM_DECL: + /* The tsubst call is used to handle cases such as + + template <int> class C {}; + template <class T, template <T> class TT> class D {}; + D<int, C> d; + + i.e. the parameter list of TT depends on earlier parameters. */ + if (!uses_template_parms (TREE_TYPE (arg)) + && !same_type_p + (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl), + TREE_TYPE (arg))) + return 0; + + if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg)) + && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))) + /* Argument is a parameter pack but parameter is not. */ + return 0; + + break; + + default: + gcc_unreachable (); + } + + return 1; +} + + +/* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for + template template parameters. Both PARM_PARMS and ARG_PARMS are + vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL + or PARM_DECL. + + Consider the example: + template <class T> class A; + template<template <class U> class TT> class B; + + For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are + the parameters to A, and OUTER_ARGS contains A. */ + +static int +coerce_template_template_parms (tree parm_parms, + tree arg_parms, + tsubst_flags_t complain, + tree in_decl, + tree outer_args) +{ + int nparms, nargs, i; + tree parm, arg; + int variadic_p = 0; + + gcc_assert (TREE_CODE (parm_parms) == TREE_VEC); + gcc_assert (TREE_CODE (arg_parms) == TREE_VEC); + + nparms = TREE_VEC_LENGTH (parm_parms); + nargs = TREE_VEC_LENGTH (arg_parms); + + /* Determine whether we have a parameter pack at the end of the + template template parameter's template parameter list. */ + if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node) + { + parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1)); + + if (parm == error_mark_node) + return 0; + + switch (TREE_CODE (parm)) + { + case TEMPLATE_DECL: + case TYPE_DECL: + if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))) + variadic_p = 1; + break; + + case PARM_DECL: + if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))) + variadic_p = 1; + break; + + default: + gcc_unreachable (); + } + } + + if (nargs != nparms + && !(variadic_p && nargs >= nparms - 1)) + return 0; + + /* Check all of the template parameters except the parameter pack at + the end (if any). */ + for (i = 0; i < nparms - variadic_p; ++i) + { + if (TREE_VEC_ELT (parm_parms, i) == error_mark_node + || TREE_VEC_ELT (arg_parms, i) == error_mark_node) + continue; + + parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i)); + arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i)); + + if (!coerce_template_template_parm (parm, arg, complain, in_decl, + outer_args)) + return 0; + + } + + if (variadic_p) + { + /* Check each of the template parameters in the template + argument against the template parameter pack at the end of + the template template parameter. */ + if (TREE_VEC_ELT (parm_parms, i) == error_mark_node) + return 0; + + parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i)); + + for (; i < nargs; ++i) + { + if (TREE_VEC_ELT (arg_parms, i) == error_mark_node) + continue; + + arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i)); + + if (!coerce_template_template_parm (parm, arg, complain, in_decl, + outer_args)) + return 0; + } + } + + return 1; +} + +/* Verifies that the deduced template arguments (in TARGS) for the + template template parameters (in TPARMS) represent valid bindings, + by comparing the template parameter list of each template argument + to the template parameter list of its corresponding template + template parameter, in accordance with DR150. This + routine can only be called after all template arguments have been + deduced. It will return TRUE if all of the template template + parameter bindings are okay, FALSE otherwise. */ +bool +template_template_parm_bindings_ok_p (tree tparms, tree targs) +{ + int i, ntparms = TREE_VEC_LENGTH (tparms); + bool ret = true; + + /* We're dealing with template parms in this process. */ + ++processing_template_decl; + + targs = INNERMOST_TEMPLATE_ARGS (targs); + + for (i = 0; i < ntparms; ++i) + { + tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i)); + tree targ = TREE_VEC_ELT (targs, i); + + if (TREE_CODE (tparm) == TEMPLATE_DECL && targ) + { + tree packed_args = NULL_TREE; + int idx, len = 1; + + if (ARGUMENT_PACK_P (targ)) + { + /* Look inside the argument pack. */ + packed_args = ARGUMENT_PACK_ARGS (targ); + len = TREE_VEC_LENGTH (packed_args); + } + + for (idx = 0; idx < len; ++idx) + { + tree targ_parms = NULL_TREE; + + if (packed_args) + /* Extract the next argument from the argument + pack. */ + targ = TREE_VEC_ELT (packed_args, idx); + + if (PACK_EXPANSION_P (targ)) + /* Look at the pattern of the pack expansion. */ + targ = PACK_EXPANSION_PATTERN (targ); + + /* Extract the template parameters from the template + argument. */ + if (TREE_CODE (targ) == TEMPLATE_DECL) + targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ); + else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM) + targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ)); + + /* Verify that we can coerce the template template + parameters from the template argument to the template + parameter. This requires an exact match. */ + if (targ_parms + && !coerce_template_template_parms + (DECL_INNERMOST_TEMPLATE_PARMS (tparm), + targ_parms, + tf_none, + tparm, + targs)) + { + ret = false; + goto out; + } + } + } + } + + out: + + --processing_template_decl; + return ret; +} + +/* Since type attributes aren't mangled, we need to strip them from + template type arguments. */ + +static tree +canonicalize_type_argument (tree arg, tsubst_flags_t complain) +{ + tree mv; + if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg)) + return arg; + mv = TYPE_MAIN_VARIANT (arg); + arg = strip_typedefs (arg); + if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv) + || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv)) + { + if (complain & tf_warning) + warning (0, "ignoring attributes on template argument %qT", arg); + arg = build_aligned_type (arg, TYPE_ALIGN (mv)); + arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv)); + } + return arg; +} + +/* Convert the indicated template ARG as necessary to match the + indicated template PARM. Returns the converted ARG, or + error_mark_node if the conversion was unsuccessful. Error and + warning messages are issued under control of COMPLAIN. This + conversion is for the Ith parameter in the parameter list. ARGS is + the full set of template arguments deduced so far. */ + +static tree +convert_template_argument (tree parm, + tree arg, + tree args, + tsubst_flags_t complain, + int i, + tree in_decl) +{ + tree orig_arg; + tree val; + int is_type, requires_type, is_tmpl_type, requires_tmpl_type; + + if (TREE_CODE (arg) == TREE_LIST + && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF) + { + /* The template argument was the name of some + member function. That's usually + invalid, but static members are OK. In any + case, grab the underlying fields/functions + and issue an error later if required. */ + orig_arg = TREE_VALUE (arg); + TREE_TYPE (arg) = unknown_type_node; + } + + orig_arg = arg; + + requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL; + requires_type = (TREE_CODE (parm) == TYPE_DECL + || requires_tmpl_type); + + /* When determining whether an argument pack expansion is a template, + look at the pattern. */ + if (TREE_CODE (arg) == TYPE_PACK_EXPANSION) + arg = PACK_EXPANSION_PATTERN (arg); + + /* Deal with an injected-class-name used as a template template arg. */ + if (requires_tmpl_type && CLASS_TYPE_P (arg)) + { + tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg)); + if (TREE_CODE (t) == TEMPLATE_DECL) + { + if (cxx_dialect >= cxx11) + /* OK under DR 1004. */; + else if (complain & tf_warning_or_error) + pedwarn (input_location, OPT_Wpedantic, "injected-class-name %qD" + " used as template template argument", TYPE_NAME (arg)); + else if (flag_pedantic_errors) + t = arg; + + arg = t; + } + } + + is_tmpl_type = + ((TREE_CODE (arg) == TEMPLATE_DECL + && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL) + || (requires_tmpl_type && TREE_CODE (arg) == TYPE_ARGUMENT_PACK) + || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM + || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE); + + if (is_tmpl_type + && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM + || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)) + arg = TYPE_STUB_DECL (arg); + + is_type = TYPE_P (arg) || is_tmpl_type; + + if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF + && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM) + { + if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR) + { + if (complain & tf_error) + error ("invalid use of destructor %qE as a type", orig_arg); + return error_mark_node; + } + + permerror (input_location, + "to refer to a type member of a template parameter, " + "use %<typename %E%>", orig_arg); + + orig_arg = make_typename_type (TREE_OPERAND (arg, 0), + TREE_OPERAND (arg, 1), + typename_type, + complain); + arg = orig_arg; + is_type = 1; + } + if (is_type != requires_type) + { + if (in_decl) + { + if (complain & tf_error) + { + error ("type/value mismatch at argument %d in template " + "parameter list for %qD", + i + 1, in_decl); + if (is_type) + error (" expected a constant of type %qT, got %qT", + TREE_TYPE (parm), + (DECL_P (arg) ? DECL_NAME (arg) : orig_arg)); + else if (requires_tmpl_type) + error (" expected a class template, got %qE", orig_arg); + else + error (" expected a type, got %qE", orig_arg); + } + } + return error_mark_node; + } + if (is_tmpl_type ^ requires_tmpl_type) + { + if (in_decl && (complain & tf_error)) + { + error ("type/value mismatch at argument %d in template " + "parameter list for %qD", + i + 1, in_decl); + if (is_tmpl_type) + error (" expected a type, got %qT", DECL_NAME (arg)); + else + error (" expected a class template, got %qT", orig_arg); + } + return error_mark_node; + } + + if (is_type) + { + if (requires_tmpl_type) + { + if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg)) + val = orig_arg; + else if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE) + /* The number of argument required is not known yet. + Just accept it for now. */ + val = TREE_TYPE (arg); + else + { + tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm); + tree argparm; + + /* Strip alias templates that are equivalent to another + template. */ + arg = get_underlying_template (arg); + argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg); + + if (coerce_template_template_parms (parmparm, argparm, + complain, in_decl, + args)) + { + val = arg; + + /* TEMPLATE_TEMPLATE_PARM node is preferred over + TEMPLATE_DECL. */ + if (val != error_mark_node) + { + if (DECL_TEMPLATE_TEMPLATE_PARM_P (val)) + val = TREE_TYPE (val); + if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION) + val = make_pack_expansion (val); + } + } + else + { + if (in_decl && (complain & tf_error)) + { + error ("type/value mismatch at argument %d in " + "template parameter list for %qD", + i + 1, in_decl); + error (" expected a template of type %qD, got %qT", + parm, orig_arg); + } + + val = error_mark_node; + } + } + } + else + val = orig_arg; + /* We only form one instance of each template specialization. + Therefore, if we use a non-canonical variant (i.e., a + typedef), any future messages referring to the type will use + the typedef, which is confusing if those future uses do not + themselves also use the typedef. */ + if (TYPE_P (val)) + val = canonicalize_type_argument (val, complain); + } + else + { + tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl); + + if (invalid_nontype_parm_type_p (t, complain)) + return error_mark_node; + + if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg)) + { + if (same_type_p (t, TREE_TYPE (orig_arg))) + val = orig_arg; + else + { + /* Not sure if this is reachable, but it doesn't hurt + to be robust. */ + error ("type mismatch in nontype parameter pack"); + val = error_mark_node; + } + } + else if (!dependent_template_arg_p (orig_arg) + && !uses_template_parms (t)) + /* We used to call digest_init here. However, digest_init + will report errors, which we don't want when complain + is zero. More importantly, digest_init will try too + hard to convert things: for example, `0' should not be + converted to pointer type at this point according to + the standard. Accepting this is not merely an + extension, since deciding whether or not these + conversions can occur is part of determining which + function template to call, or whether a given explicit + argument specification is valid. */ + val = convert_nontype_argument (t, orig_arg, complain); + else + val = strip_typedefs_expr (orig_arg); + + if (val == NULL_TREE) + val = error_mark_node; + else if (val == error_mark_node && (complain & tf_error)) + error ("could not convert template argument %qE to %qT", orig_arg, t); + + if (TREE_CODE (val) == SCOPE_REF) + { + /* Strip typedefs from the SCOPE_REF. */ + tree type = canonicalize_type_argument (TREE_TYPE (val), complain); + tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0), + complain); + val = build_qualified_name (type, scope, TREE_OPERAND (val, 1), + QUALIFIED_NAME_IS_TEMPLATE (val)); + } + } + + return val; +} + +/* Coerces the remaining template arguments in INNER_ARGS (from + ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS. + Returns the coerced argument pack. PARM_IDX is the position of this + parameter in the template parameter list. ARGS is the original + template argument list. */ +static tree +coerce_template_parameter_pack (tree parms, + int parm_idx, + tree args, + tree inner_args, + int arg_idx, + tree new_args, + int* lost, + tree in_decl, + tsubst_flags_t complain) +{ + tree parm = TREE_VEC_ELT (parms, parm_idx); + int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0; + tree packed_args; + tree argument_pack; + tree packed_parms = NULL_TREE; + + if (arg_idx > nargs) + arg_idx = nargs; + + if (tree packs = fixed_parameter_pack_p (TREE_VALUE (parm))) + { + /* When the template parameter is a non-type template parameter pack + or template template parameter pack whose type or template + parameters use parameter packs, we know exactly how many arguments + we are looking for. Build a vector of the instantiated decls for + these template parameters in PACKED_PARMS. */ + /* We can't use make_pack_expansion here because it would interpret a + _DECL as a use rather than a declaration. */ + tree decl = TREE_VALUE (parm); + tree exp = cxx_make_type (TYPE_PACK_EXPANSION); + SET_PACK_EXPANSION_PATTERN (exp, decl); + PACK_EXPANSION_PARAMETER_PACKS (exp) = packs; + SET_TYPE_STRUCTURAL_EQUALITY (exp); + + TREE_VEC_LENGTH (args)--; + packed_parms = tsubst_pack_expansion (exp, args, complain, decl); + TREE_VEC_LENGTH (args)++; + + if (packed_parms == error_mark_node) + return error_mark_node; + + /* If we're doing a partial instantiation of a member template, + verify that all of the types used for the non-type + template parameter pack are, in fact, valid for non-type + template parameters. */ + if (arg_idx < nargs + && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))) + { + int j, len = TREE_VEC_LENGTH (packed_parms); + for (j = 0; j < len; ++j) + { + tree t = TREE_TYPE (TREE_VEC_ELT (packed_parms, j)); + if (invalid_nontype_parm_type_p (t, complain)) + return error_mark_node; + } + } + + packed_args = make_tree_vec (TREE_VEC_LENGTH (packed_parms)); + } + else + packed_args = make_tree_vec (nargs - arg_idx); + + /* Convert the remaining arguments, which will be a part of the + parameter pack "parm". */ + for (; arg_idx < nargs; ++arg_idx) + { + tree arg = TREE_VEC_ELT (inner_args, arg_idx); + tree actual_parm = TREE_VALUE (parm); + int pack_idx = arg_idx - parm_idx; + + if (packed_parms) + { + /* Once we've packed as many args as we have types, stop. */ + if (pack_idx >= TREE_VEC_LENGTH (packed_parms)) + break; + else if (PACK_EXPANSION_P (arg)) + /* We don't know how many args we have yet, just + use the unconverted ones for now. */ + return NULL_TREE; + else + actual_parm = TREE_VEC_ELT (packed_parms, pack_idx); + } + + if (arg == error_mark_node) + { + if (complain & tf_error) + error ("template argument %d is invalid", arg_idx + 1); + } + else + arg = convert_template_argument (actual_parm, + arg, new_args, complain, parm_idx, + in_decl); + if (arg == error_mark_node) + (*lost)++; + TREE_VEC_ELT (packed_args, pack_idx) = arg; + } + + if (arg_idx - parm_idx < TREE_VEC_LENGTH (packed_args) + && TREE_VEC_LENGTH (packed_args) > 0) + { + error ("wrong number of template arguments (%d, should be %d)", + arg_idx - parm_idx, TREE_VEC_LENGTH (packed_args)); + return error_mark_node; + } + + if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL + || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL) + argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK); + else + { + argument_pack = make_node (NONTYPE_ARGUMENT_PACK); + TREE_TYPE (argument_pack) + = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl); + TREE_CONSTANT (argument_pack) = 1; + } + + SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args); +#ifdef ENABLE_CHECKING + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args, + TREE_VEC_LENGTH (packed_args)); +#endif + return argument_pack; +} + +/* Returns the number of pack expansions in the template argument vector + ARGS. */ + +static int +pack_expansion_args_count (tree args) +{ + int i; + int count = 0; + if (args) + for (i = 0; i < TREE_VEC_LENGTH (args); ++i) + { + tree elt = TREE_VEC_ELT (args, i); + if (elt && PACK_EXPANSION_P (elt)) + ++count; + } + return count; +} + +/* Convert all template arguments to their appropriate types, and + return a vector containing the innermost resulting template + arguments. If any error occurs, return error_mark_node. Error and + warning messages are issued under control of COMPLAIN. + + If REQUIRE_ALL_ARGS is false, argument deduction will be performed + for arguments not specified in ARGS. Otherwise, if + USE_DEFAULT_ARGS is true, default arguments will be used to fill in + unspecified arguments. If REQUIRE_ALL_ARGS is true, but + USE_DEFAULT_ARGS is false, then all arguments must be specified in + ARGS. */ + +static tree +coerce_template_parms (tree parms, + tree args, + tree in_decl, + tsubst_flags_t complain, + bool require_all_args, + bool use_default_args) +{ + int nparms, nargs, parm_idx, arg_idx, lost = 0; + tree orig_inner_args; + tree inner_args; + tree new_args; + tree new_inner_args; + int saved_unevaluated_operand; + int saved_inhibit_evaluation_warnings; + + /* When used as a boolean value, indicates whether this is a + variadic template parameter list. Since it's an int, we can also + subtract it from nparms to get the number of non-variadic + parameters. */ + int variadic_p = 0; + int variadic_args_p = 0; + int post_variadic_parms = 0; + + if (args == error_mark_node) + return error_mark_node; + + nparms = TREE_VEC_LENGTH (parms); + + /* Determine if there are any parameter packs. */ + for (parm_idx = 0; parm_idx < nparms; ++parm_idx) + { + tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx)); + if (variadic_p) + ++post_variadic_parms; + if (template_parameter_pack_p (tparm)) + ++variadic_p; + } + + inner_args = orig_inner_args = INNERMOST_TEMPLATE_ARGS (args); + /* If there are no parameters that follow a parameter pack, we need to + expand any argument packs so that we can deduce a parameter pack from + some non-packed args followed by an argument pack, as in variadic85.C. + If there are such parameters, we need to leave argument packs intact + so the arguments are assigned properly. This can happen when dealing + with a nested class inside a partial specialization of a class + template, as in variadic92.C, or when deducing a template parameter pack + from a sub-declarator, as in variadic114.C. */ + if (!post_variadic_parms) + inner_args = expand_template_argument_pack (inner_args); + + /* Count any pack expansion args. */ + variadic_args_p = pack_expansion_args_count (inner_args); + + nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0; + if ((nargs > nparms && !variadic_p) + || (nargs < nparms - variadic_p + && require_all_args + && !variadic_args_p + && (!use_default_args + || (TREE_VEC_ELT (parms, nargs) != error_mark_node + && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs)))))) + { + if (complain & tf_error) + { + if (variadic_p) + { + nparms -= variadic_p; + error ("wrong number of template arguments " + "(%d, should be %d or more)", nargs, nparms); + } + else + error ("wrong number of template arguments " + "(%d, should be %d)", nargs, nparms); + + if (in_decl) + error ("provided for %q+D", in_decl); + } + + return error_mark_node; + } + /* We can't pass a pack expansion to a non-pack parameter of an alias + template (DR 1430). */ + else if (in_decl && DECL_ALIAS_TEMPLATE_P (in_decl) + && variadic_args_p + && nargs - variadic_args_p < nparms - variadic_p) + { + if (complain & tf_error) + { + for (int i = 0; i < TREE_VEC_LENGTH (inner_args); ++i) + { + tree arg = TREE_VEC_ELT (inner_args, i); + tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i)); + + if (PACK_EXPANSION_P (arg) + && !template_parameter_pack_p (parm)) + { + error ("pack expansion argument for non-pack parameter " + "%qD of alias template %qD", parm, in_decl); + inform (DECL_SOURCE_LOCATION (parm), "declared here"); + goto found; + } + } + gcc_unreachable (); + found:; + } + return error_mark_node; + } + + /* We need to evaluate the template arguments, even though this + template-id may be nested within a "sizeof". */ + saved_unevaluated_operand = cp_unevaluated_operand; + cp_unevaluated_operand = 0; + saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings; + c_inhibit_evaluation_warnings = 0; + new_inner_args = make_tree_vec (nparms); + new_args = add_outermost_template_args (args, new_inner_args); + int pack_adjust = 0; + for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++) + { + tree arg; + tree parm; + + /* Get the Ith template parameter. */ + parm = TREE_VEC_ELT (parms, parm_idx); + + if (parm == error_mark_node) + { + TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node; + continue; + } + + /* Calculate the next argument. */ + if (arg_idx < nargs) + arg = TREE_VEC_ELT (inner_args, arg_idx); + else + arg = NULL_TREE; + + if (template_parameter_pack_p (TREE_VALUE (parm)) + && !(arg && ARGUMENT_PACK_P (arg))) + { + /* Some arguments will be placed in the + template parameter pack PARM. */ + arg = coerce_template_parameter_pack (parms, parm_idx, args, + inner_args, arg_idx, + new_args, &lost, + in_decl, complain); + + if (arg == NULL_TREE) + { + /* We don't know how many args we have yet, just use the + unconverted (and still packed) ones for now. */ + new_inner_args = orig_inner_args; + arg_idx = nargs; + break; + } + + TREE_VEC_ELT (new_inner_args, parm_idx) = arg; + + /* Store this argument. */ + if (arg == error_mark_node) + { + lost++; + /* We are done with all of the arguments. */ + arg_idx = nargs; + } + else + { + pack_adjust = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg)) - 1; + arg_idx += pack_adjust; + } + + continue; + } + else if (arg) + { + if (PACK_EXPANSION_P (arg)) + { + /* We don't know how many args we have yet, just + use the unconverted ones for now. */ + new_inner_args = inner_args; + arg_idx = nargs; + break; + } + } + else if (require_all_args) + { + /* There must be a default arg in this case. */ + arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args, + complain, in_decl); + /* The position of the first default template argument, + is also the number of non-defaulted arguments in NEW_INNER_ARGS. + Record that. */ + if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args)) + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, + arg_idx - pack_adjust); + } + else + break; + + if (arg == error_mark_node) + { + if (complain & tf_error) + error ("template argument %d is invalid", arg_idx + 1); + } + else if (!arg) + /* This only occurs if there was an error in the template + parameter list itself (which we would already have + reported) that we are trying to recover from, e.g., a class + template with a parameter list such as + template<typename..., typename>. */ + ++lost; + else + arg = convert_template_argument (TREE_VALUE (parm), + arg, new_args, complain, + parm_idx, in_decl); + + if (arg == error_mark_node) + lost++; + TREE_VEC_ELT (new_inner_args, arg_idx - pack_adjust) = arg; + } + cp_unevaluated_operand = saved_unevaluated_operand; + c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings; + + if (variadic_p && arg_idx < nargs) + { + if (complain & tf_error) + { + error ("wrong number of template arguments " + "(%d, should be %d)", nargs, arg_idx); + if (in_decl) + error ("provided for %q+D", in_decl); + } + return error_mark_node; + } + + if (lost) + return error_mark_node; + +#ifdef ENABLE_CHECKING + if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args)) + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, + TREE_VEC_LENGTH (new_inner_args)); +#endif + + return new_inner_args; +} + +/* Like coerce_template_parms. If PARMS represents all template + parameters levels, this function returns a vector of vectors + representing all the resulting argument levels. Note that in this + case, only the innermost arguments are coerced because the + outermost ones are supposed to have been coerced already. + + Otherwise, if PARMS represents only (the innermost) vector of + parameters, this function returns a vector containing just the + innermost resulting arguments. */ + +static tree +coerce_innermost_template_parms (tree parms, + tree args, + tree in_decl, + tsubst_flags_t complain, + bool require_all_args, + bool use_default_args) +{ + int parms_depth = TMPL_PARMS_DEPTH (parms); + int args_depth = TMPL_ARGS_DEPTH (args); + tree coerced_args; + + if (parms_depth > 1) + { + coerced_args = make_tree_vec (parms_depth); + tree level; + int cur_depth; + + for (level = parms, cur_depth = parms_depth; + parms_depth > 0 && level != NULL_TREE; + level = TREE_CHAIN (level), --cur_depth) + { + tree l; + if (cur_depth == args_depth) + l = coerce_template_parms (TREE_VALUE (level), + args, in_decl, complain, + require_all_args, + use_default_args); + else + l = TMPL_ARGS_LEVEL (args, cur_depth); + + if (l == error_mark_node) + return error_mark_node; + + SET_TMPL_ARGS_LEVEL (coerced_args, cur_depth, l); + } + } + else + coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms), + args, in_decl, complain, + require_all_args, + use_default_args); + return coerced_args; +} + +/* Returns 1 if template args OT and NT are equivalent. */ + +static int +template_args_equal (tree ot, tree nt) +{ + if (nt == ot) + return 1; + if (nt == NULL_TREE || ot == NULL_TREE) + return false; + + if (TREE_CODE (nt) == TREE_VEC) + /* For member templates */ + return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt); + else if (PACK_EXPANSION_P (ot)) + return (PACK_EXPANSION_P (nt) + && template_args_equal (PACK_EXPANSION_PATTERN (ot), + PACK_EXPANSION_PATTERN (nt)) + && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot), + PACK_EXPANSION_EXTRA_ARGS (nt))); + else if (ARGUMENT_PACK_P (ot)) + { + int i, len; + tree opack, npack; + + if (!ARGUMENT_PACK_P (nt)) + return 0; + + opack = ARGUMENT_PACK_ARGS (ot); + npack = ARGUMENT_PACK_ARGS (nt); + len = TREE_VEC_LENGTH (opack); + if (TREE_VEC_LENGTH (npack) != len) + return 0; + for (i = 0; i < len; ++i) + if (!template_args_equal (TREE_VEC_ELT (opack, i), + TREE_VEC_ELT (npack, i))) + return 0; + return 1; + } + else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT) + { + /* We get here probably because we are in the middle of substituting + into the pattern of a pack expansion. In that case the + ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are + interested in. So we want to use the initial pack argument for + the comparison. */ + ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot); + if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT) + nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt); + return template_args_equal (ot, nt); + } + else if (TYPE_P (nt)) + return TYPE_P (ot) && same_type_p (ot, nt); + else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot)) + return 0; + else + return cp_tree_equal (ot, nt); +} + +/* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of + template arguments. Returns 0 otherwise, and updates OLDARG_PTR and + NEWARG_PTR with the offending arguments if they are non-NULL. */ + +static int +comp_template_args_with_info (tree oldargs, tree newargs, + tree *oldarg_ptr, tree *newarg_ptr) +{ + int i; + + if (oldargs == newargs) + return 1; + + if (!oldargs || !newargs) + return 0; + + if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs)) + return 0; + + for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i) + { + tree nt = TREE_VEC_ELT (newargs, i); + tree ot = TREE_VEC_ELT (oldargs, i); + + if (! template_args_equal (ot, nt)) + { + if (oldarg_ptr != NULL) + *oldarg_ptr = ot; + if (newarg_ptr != NULL) + *newarg_ptr = nt; + return 0; + } + } + return 1; +} + +/* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets + of template arguments. Returns 0 otherwise. */ + +int +comp_template_args (tree oldargs, tree newargs) +{ + return comp_template_args_with_info (oldargs, newargs, NULL, NULL); +} + +static void +add_pending_template (tree d) +{ + tree ti = (TYPE_P (d) + ? CLASSTYPE_TEMPLATE_INFO (d) + : DECL_TEMPLATE_INFO (d)); + struct pending_template *pt; + int level; + + if (TI_PENDING_TEMPLATE_FLAG (ti)) + return; + + /* We are called both from instantiate_decl, where we've already had a + tinst_level pushed, and instantiate_template, where we haven't. + Compensate. */ + level = !current_tinst_level || current_tinst_level->decl != d; + + if (level) + push_tinst_level (d); + + pt = ggc_alloc_pending_template (); + pt->next = NULL; + pt->tinst = current_tinst_level; + if (last_pending_template) + last_pending_template->next = pt; + else + pending_templates = pt; + + last_pending_template = pt; + + TI_PENDING_TEMPLATE_FLAG (ti) = 1; + + if (level) + pop_tinst_level (); +} + + +/* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and + ARGLIST. Valid choices for FNS are given in the cp-tree.def + documentation for TEMPLATE_ID_EXPR. */ + +tree +lookup_template_function (tree fns, tree arglist) +{ + tree type; + + if (fns == error_mark_node || arglist == error_mark_node) + return error_mark_node; + + gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC); + + if (!is_overloaded_fn (fns) && !identifier_p (fns)) + { + error ("%q#D is not a function template", fns); + return error_mark_node; + } + + if (BASELINK_P (fns)) + { + BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR, + unknown_type_node, + BASELINK_FUNCTIONS (fns), + arglist); + return fns; + } + + type = TREE_TYPE (fns); + if (TREE_CODE (fns) == OVERLOAD || !type) + type = unknown_type_node; + + return build2 (TEMPLATE_ID_EXPR, type, fns, arglist); +} + +/* Within the scope of a template class S<T>, the name S gets bound + (in build_self_reference) to a TYPE_DECL for the class, not a + TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type, + or one of its enclosing classes, and that type is a template, + return the associated TEMPLATE_DECL. Otherwise, the original + DECL is returned. + + Also handle the case when DECL is a TREE_LIST of ambiguous + injected-class-names from different bases. */ + +tree +maybe_get_template_decl_from_type_decl (tree decl) +{ + if (decl == NULL_TREE) + return decl; + + /* DR 176: A lookup that finds an injected-class-name (10.2 + [class.member.lookup]) can result in an ambiguity in certain cases + (for example, if it is found in more than one base class). If all of + the injected-class-names that are found refer to specializations of + the same class template, and if the name is followed by a + template-argument-list, the reference refers to the class template + itself and not a specialization thereof, and is not ambiguous. */ + if (TREE_CODE (decl) == TREE_LIST) + { + tree t, tmpl = NULL_TREE; + for (t = decl; t; t = TREE_CHAIN (t)) + { + tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t)); + if (!tmpl) + tmpl = elt; + else if (tmpl != elt) + break; + } + if (tmpl && t == NULL_TREE) + return tmpl; + else + return decl; + } + + return (decl != NULL_TREE + && DECL_SELF_REFERENCE_P (decl) + && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl))) + ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl; +} + +/* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of + parameters, find the desired type. + + D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments. + + IN_DECL, if non-NULL, is the template declaration we are trying to + instantiate. + + If ENTERING_SCOPE is nonzero, we are about to enter the scope of + the class we are looking up. + + Issue error and warning messages under control of COMPLAIN. + + If the template class is really a local class in a template + function, then the FUNCTION_CONTEXT is the function in which it is + being instantiated. + + ??? Note that this function is currently called *twice* for each + template-id: the first time from the parser, while creating the + incomplete type (finish_template_type), and the second type during the + real instantiation (instantiate_template_class). This is surely something + that we want to avoid. It also causes some problems with argument + coercion (see convert_nontype_argument for more information on this). */ + +static tree +lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context, + int entering_scope, tsubst_flags_t complain) +{ + tree templ = NULL_TREE, parmlist; + tree t; + void **slot; + spec_entry *entry; + spec_entry elt; + hashval_t hash; + + if (identifier_p (d1)) + { + tree value = innermost_non_namespace_value (d1); + if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value)) + templ = value; + else + { + if (context) + push_decl_namespace (context); + templ = lookup_name (d1); + templ = maybe_get_template_decl_from_type_decl (templ); + if (context) + pop_decl_namespace (); + } + if (templ) + context = DECL_CONTEXT (templ); + } + else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1))) + { + tree type = TREE_TYPE (d1); + + /* If we are declaring a constructor, say A<T>::A<T>, we will get + an implicit typename for the second A. Deal with it. */ + if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type)) + type = TREE_TYPE (type); + + if (CLASSTYPE_TEMPLATE_INFO (type)) + { + templ = CLASSTYPE_TI_TEMPLATE (type); + d1 = DECL_NAME (templ); + } + } + else if (TREE_CODE (d1) == ENUMERAL_TYPE + || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1))) + { + templ = TYPE_TI_TEMPLATE (d1); + d1 = DECL_NAME (templ); + } + else if (TREE_CODE (d1) == TEMPLATE_DECL + && DECL_TEMPLATE_RESULT (d1) + && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL) + { + templ = d1; + d1 = DECL_NAME (templ); + context = DECL_CONTEXT (templ); + } + else if (DECL_TEMPLATE_TEMPLATE_PARM_P (d1)) + { + templ = d1; + d1 = DECL_NAME (templ); + } + + /* Issue an error message if we didn't find a template. */ + if (! templ) + { + if (complain & tf_error) + error ("%qT is not a template", d1); + return error_mark_node; + } + + if (TREE_CODE (templ) != TEMPLATE_DECL + /* Make sure it's a user visible template, if it was named by + the user. */ + || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ) + && !PRIMARY_TEMPLATE_P (templ))) + { + if (complain & tf_error) + { + error ("non-template type %qT used as a template", d1); + if (in_decl) + error ("for template declaration %q+D", in_decl); + } + return error_mark_node; + } + + complain &= ~tf_user; + + /* An alias that just changes the name of a template is equivalent to the + other template, so if any of the arguments are pack expansions, strip + the alias to avoid problems with a pack expansion passed to a non-pack + alias template parameter (DR 1430). */ + if (pack_expansion_args_count (INNERMOST_TEMPLATE_ARGS (arglist))) + templ = get_underlying_template (templ); + + if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ)) + { + /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store + template arguments */ + + tree parm; + tree arglist2; + tree outer; + + parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ); + + /* Consider an example where a template template parameter declared as + + template <class T, class U = std::allocator<T> > class TT + + The template parameter level of T and U are one level larger than + of TT. To proper process the default argument of U, say when an + instantiation `TT<int>' is seen, we need to build the full + arguments containing {int} as the innermost level. Outer levels, + available when not appearing as default template argument, can be + obtained from the arguments of the enclosing template. + + Suppose that TT is later substituted with std::vector. The above + instantiation is `TT<int, std::allocator<T> >' with TT at + level 1, and T at level 2, while the template arguments at level 1 + becomes {std::vector} and the inner level 2 is {int}. */ + + outer = DECL_CONTEXT (templ); + if (outer) + outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer))); + else if (current_template_parms) + /* This is an argument of the current template, so we haven't set + DECL_CONTEXT yet. */ + outer = current_template_args (); + + if (outer) + arglist = add_to_template_args (outer, arglist); + + arglist2 = coerce_template_parms (parmlist, arglist, templ, + complain, + /*require_all_args=*/true, + /*use_default_args=*/true); + if (arglist2 == error_mark_node + || (!uses_template_parms (arglist2) + && check_instantiated_args (templ, arglist2, complain))) + return error_mark_node; + + parm = bind_template_template_parm (TREE_TYPE (templ), arglist2); + return parm; + } + else + { + tree template_type = TREE_TYPE (templ); + tree gen_tmpl; + tree type_decl; + tree found = NULL_TREE; + int arg_depth; + int parm_depth; + int is_dependent_type; + int use_partial_inst_tmpl = false; + + if (template_type == error_mark_node) + /* An error occurred while building the template TEMPL, and a + diagnostic has most certainly been emitted for that + already. Let's propagate that error. */ + return error_mark_node; + + gen_tmpl = most_general_template (templ); + parmlist = DECL_TEMPLATE_PARMS (gen_tmpl); + parm_depth = TMPL_PARMS_DEPTH (parmlist); + arg_depth = TMPL_ARGS_DEPTH (arglist); + + if (arg_depth == 1 && parm_depth > 1) + { + /* We've been given an incomplete set of template arguments. + For example, given: + + template <class T> struct S1 { + template <class U> struct S2 {}; + template <class U> struct S2<U*> {}; + }; + + we will be called with an ARGLIST of `U*', but the + TEMPLATE will be `template <class T> template + <class U> struct S1<T>::S2'. We must fill in the missing + arguments. */ + arglist + = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)), + arglist); + arg_depth = TMPL_ARGS_DEPTH (arglist); + } + + /* Now we should have enough arguments. */ + gcc_assert (parm_depth == arg_depth); + + /* From here on, we're only interested in the most general + template. */ + + /* Calculate the BOUND_ARGS. These will be the args that are + actually tsubst'd into the definition to create the + instantiation. */ + if (parm_depth > 1) + { + /* We have multiple levels of arguments to coerce, at once. */ + int i; + int saved_depth = TMPL_ARGS_DEPTH (arglist); + + tree bound_args = make_tree_vec (parm_depth); + + for (i = saved_depth, + t = DECL_TEMPLATE_PARMS (gen_tmpl); + i > 0 && t != NULL_TREE; + --i, t = TREE_CHAIN (t)) + { + tree a; + if (i == saved_depth) + a = coerce_template_parms (TREE_VALUE (t), + arglist, gen_tmpl, + complain, + /*require_all_args=*/true, + /*use_default_args=*/true); + else + /* Outer levels should have already been coerced. */ + a = TMPL_ARGS_LEVEL (arglist, i); + + /* Don't process further if one of the levels fails. */ + if (a == error_mark_node) + { + /* Restore the ARGLIST to its full size. */ + TREE_VEC_LENGTH (arglist) = saved_depth; + return error_mark_node; + } + + SET_TMPL_ARGS_LEVEL (bound_args, i, a); + + /* We temporarily reduce the length of the ARGLIST so + that coerce_template_parms will see only the arguments + corresponding to the template parameters it is + examining. */ + TREE_VEC_LENGTH (arglist)--; + } + + /* Restore the ARGLIST to its full size. */ + TREE_VEC_LENGTH (arglist) = saved_depth; + + arglist = bound_args; + } + else + arglist + = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist), + INNERMOST_TEMPLATE_ARGS (arglist), + gen_tmpl, + complain, + /*require_all_args=*/true, + /*use_default_args=*/true); + + if (arglist == error_mark_node) + /* We were unable to bind the arguments. */ + return error_mark_node; + + /* In the scope of a template class, explicit references to the + template class refer to the type of the template, not any + instantiation of it. For example, in: + + template <class T> class C { void f(C<T>); } + + the `C<T>' is just the same as `C'. Outside of the + class, however, such a reference is an instantiation. */ + if ((entering_scope + || !PRIMARY_TEMPLATE_P (gen_tmpl) + || currently_open_class (template_type)) + /* comp_template_args is expensive, check it last. */ + && comp_template_args (TYPE_TI_ARGS (template_type), + arglist)) + return template_type; + + /* If we already have this specialization, return it. */ + elt.tmpl = gen_tmpl; + elt.args = arglist; + hash = hash_specialization (&elt); + entry = (spec_entry *) htab_find_with_hash (type_specializations, + &elt, hash); + + if (entry) + return entry->spec; + + is_dependent_type = uses_template_parms (arglist); + + /* If the deduced arguments are invalid, then the binding + failed. */ + if (!is_dependent_type + && check_instantiated_args (gen_tmpl, + INNERMOST_TEMPLATE_ARGS (arglist), + complain)) + return error_mark_node; + + if (!is_dependent_type + && !PRIMARY_TEMPLATE_P (gen_tmpl) + && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl)) + && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL) + { + found = xref_tag_from_type (TREE_TYPE (gen_tmpl), + DECL_NAME (gen_tmpl), + /*tag_scope=*/ts_global); + return found; + } + + context = tsubst (DECL_CONTEXT (gen_tmpl), arglist, + complain, in_decl); + if (context == error_mark_node) + return error_mark_node; + + if (!context) + context = global_namespace; + + /* Create the type. */ + if (DECL_ALIAS_TEMPLATE_P (gen_tmpl)) + { + /* The user referred to a specialization of an alias + template represented by GEN_TMPL. + + [temp.alias]/2 says: + + When a template-id refers to the specialization of an + alias template, it is equivalent to the associated + type obtained by substitution of its + template-arguments for the template-parameters in the + type-id of the alias template. */ + + t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl); + /* Note that the call above (by indirectly calling + register_specialization in tsubst_decl) registers the + TYPE_DECL representing the specialization of the alias + template. So next time someone substitutes ARGLIST for + the template parms into the alias template (GEN_TMPL), + she'll get that TYPE_DECL back. */ + + if (t == error_mark_node) + return t; + } + else if (TREE_CODE (template_type) == ENUMERAL_TYPE) + { + if (!is_dependent_type) + { + set_current_access_from_decl (TYPE_NAME (template_type)); + t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE, + tsubst (ENUM_UNDERLYING_TYPE (template_type), + arglist, complain, in_decl), + SCOPED_ENUM_P (template_type), NULL); + + if (t == error_mark_node) + return t; + } + else + { + /* We don't want to call start_enum for this type, since + the values for the enumeration constants may involve + template parameters. And, no one should be interested + in the enumeration constants for such a type. */ + t = cxx_make_type (ENUMERAL_TYPE); + SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type)); + } + SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type)); + ENUM_FIXED_UNDERLYING_TYPE_P (t) + = ENUM_FIXED_UNDERLYING_TYPE_P (template_type); + } + else if (CLASS_TYPE_P (template_type)) + { + t = make_class_type (TREE_CODE (template_type)); + CLASSTYPE_DECLARED_CLASS (t) + = CLASSTYPE_DECLARED_CLASS (template_type); + SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t); + TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type); + + /* A local class. Make sure the decl gets registered properly. */ + if (context == current_function_decl) + pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current); + + if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist)) + /* This instantiation is another name for the primary + template type. Set the TYPE_CANONICAL field + appropriately. */ + TYPE_CANONICAL (t) = template_type; + else if (any_template_arguments_need_structural_equality_p (arglist)) + /* Some of the template arguments require structural + equality testing, so this template class requires + structural equality testing. */ + SET_TYPE_STRUCTURAL_EQUALITY (t); + } + else + gcc_unreachable (); + + /* If we called start_enum or pushtag above, this information + will already be set up. */ + if (!TYPE_NAME (t)) + { + TYPE_CONTEXT (t) = FROB_CONTEXT (context); + + type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t); + DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t); + DECL_SOURCE_LOCATION (type_decl) + = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type)); + } + else + type_decl = TYPE_NAME (t); + + if (CLASS_TYPE_P (template_type)) + { + TREE_PRIVATE (type_decl) + = TREE_PRIVATE (TYPE_MAIN_DECL (template_type)); + TREE_PROTECTED (type_decl) + = TREE_PROTECTED (TYPE_MAIN_DECL (template_type)); + if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type)) + { + DECL_VISIBILITY_SPECIFIED (type_decl) = 1; + DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type); + } + } + + /* Let's consider the explicit specialization of a member + of a class template specialization that is implicitly instantiated, + e.g.: + template<class T> + struct S + { + template<class U> struct M {}; //#0 + }; + + template<> + template<> + struct S<int>::M<char> //#1 + { + int i; + }; + [temp.expl.spec]/4 says this is valid. + + In this case, when we write: + S<int>::M<char> m; + + M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from + the one of #0. + + When we encounter #1, we want to store the partial instantiation + of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE. + + For all cases other than this "explicit specialization of member of a + class template", we just want to store the most general template into + the CLASSTYPE_TI_TEMPLATE of M. + + This case of "explicit specialization of member of a class template" + only happens when: + 1/ the enclosing class is an instantiation of, and therefore not + the same as, the context of the most general template, and + 2/ we aren't looking at the partial instantiation itself, i.e. + the innermost arguments are not the same as the innermost parms of + the most general template. + + So it's only when 1/ and 2/ happens that we want to use the partial + instantiation of the member template in lieu of its most general + template. */ + + if (PRIMARY_TEMPLATE_P (gen_tmpl) + && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist) + /* the enclosing class must be an instantiation... */ + && CLASS_TYPE_P (context) + && !same_type_p (context, DECL_CONTEXT (gen_tmpl))) + { + tree partial_inst_args; + TREE_VEC_LENGTH (arglist)--; + ++processing_template_decl; + partial_inst_args = + tsubst (INNERMOST_TEMPLATE_ARGS + (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))), + arglist, complain, NULL_TREE); + --processing_template_decl; + TREE_VEC_LENGTH (arglist)++; + use_partial_inst_tmpl = + /*...and we must not be looking at the partial instantiation + itself. */ + !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist), + partial_inst_args); + } + + if (!use_partial_inst_tmpl) + /* This case is easy; there are no member templates involved. */ + found = gen_tmpl; + else + { + /* This is a full instantiation of a member template. Find + the partial instantiation of which this is an instance. */ + + /* Temporarily reduce by one the number of levels in the ARGLIST + so as to avoid comparing the last set of arguments. */ + TREE_VEC_LENGTH (arglist)--; + found = tsubst (gen_tmpl, arglist, complain, NULL_TREE); + TREE_VEC_LENGTH (arglist)++; + /* FOUND is either a proper class type, or an alias + template specialization. In the later case, it's a + TYPE_DECL, resulting from the substituting of arguments + for parameters in the TYPE_DECL of the alias template + done earlier. So be careful while getting the template + of FOUND. */ + found = TREE_CODE (found) == TYPE_DECL + ? TYPE_TI_TEMPLATE (TREE_TYPE (found)) + : CLASSTYPE_TI_TEMPLATE (found); + } + + SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist)); + + elt.spec = t; + slot = htab_find_slot_with_hash (type_specializations, + &elt, hash, INSERT); + entry = ggc_alloc_spec_entry (); + *entry = elt; + *slot = entry; + + /* Note this use of the partial instantiation so we can check it + later in maybe_process_partial_specialization. */ + DECL_TEMPLATE_INSTANTIATIONS (found) + = tree_cons (arglist, t, + DECL_TEMPLATE_INSTANTIATIONS (found)); + + if (TREE_CODE (template_type) == ENUMERAL_TYPE && !is_dependent_type + && !DECL_ALIAS_TEMPLATE_P (gen_tmpl)) + /* Now that the type has been registered on the instantiations + list, we set up the enumerators. Because the enumeration + constants may involve the enumeration type itself, we make + sure to register the type first, and then create the + constants. That way, doing tsubst_expr for the enumeration + constants won't result in recursive calls here; we'll find + the instantiation and exit above. */ + tsubst_enum (template_type, t, arglist); + + if (CLASS_TYPE_P (template_type) && is_dependent_type) + /* If the type makes use of template parameters, the + code that generates debugging information will crash. */ + DECL_IGNORED_P (TYPE_MAIN_DECL (t)) = 1; + + /* Possibly limit visibility based on template args. */ + TREE_PUBLIC (type_decl) = 1; + determine_visibility (type_decl); + + return t; + } +} + +/* Wrapper for lookup_template_class_1. */ + +tree +lookup_template_class (tree d1, tree arglist, tree in_decl, tree context, + int entering_scope, tsubst_flags_t complain) +{ + tree ret; + timevar_push (TV_TEMPLATE_INST); + ret = lookup_template_class_1 (d1, arglist, in_decl, context, + entering_scope, complain); + timevar_pop (TV_TEMPLATE_INST); + return ret; +} + +struct pair_fn_data +{ + tree_fn_t fn; + void *data; + /* True when we should also visit template parameters that occur in + non-deduced contexts. */ + bool include_nondeduced_p; + struct pointer_set_t *visited; +}; + +/* Called from for_each_template_parm via walk_tree. */ + +static tree +for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d) +{ + tree t = *tp; + struct pair_fn_data *pfd = (struct pair_fn_data *) d; + tree_fn_t fn = pfd->fn; + void *data = pfd->data; + + if (TYPE_P (t) + && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE) + && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited, + pfd->include_nondeduced_p)) + return error_mark_node; + + switch (TREE_CODE (t)) + { + case RECORD_TYPE: + if (TYPE_PTRMEMFUNC_P (t)) + break; + /* Fall through. */ + + case UNION_TYPE: + case ENUMERAL_TYPE: + if (!TYPE_TEMPLATE_INFO (t)) + *walk_subtrees = 0; + else if (for_each_template_parm (TYPE_TI_ARGS (t), + fn, data, pfd->visited, + pfd->include_nondeduced_p)) + return error_mark_node; + break; + + case INTEGER_TYPE: + if (for_each_template_parm (TYPE_MIN_VALUE (t), + fn, data, pfd->visited, + pfd->include_nondeduced_p) + || for_each_template_parm (TYPE_MAX_VALUE (t), + fn, data, pfd->visited, + pfd->include_nondeduced_p)) + return error_mark_node; + break; + + case METHOD_TYPE: + /* Since we're not going to walk subtrees, we have to do this + explicitly here. */ + if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data, + pfd->visited, pfd->include_nondeduced_p)) + return error_mark_node; + /* Fall through. */ + + case FUNCTION_TYPE: + /* Check the return type. */ + if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited, + pfd->include_nondeduced_p)) + return error_mark_node; + + /* Check the parameter types. Since default arguments are not + instantiated until they are needed, the TYPE_ARG_TYPES may + contain expressions that involve template parameters. But, + no-one should be looking at them yet. And, once they're + instantiated, they don't contain template parameters, so + there's no point in looking at them then, either. */ + { + tree parm; + + for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm)) + if (for_each_template_parm (TREE_VALUE (parm), fn, data, + pfd->visited, pfd->include_nondeduced_p)) + return error_mark_node; + + /* Since we've already handled the TYPE_ARG_TYPES, we don't + want walk_tree walking into them itself. */ + *walk_subtrees = 0; + } + break; + + case TYPEOF_TYPE: + case UNDERLYING_TYPE: + if (pfd->include_nondeduced_p + && for_each_template_parm (TYPE_FIELDS (t), fn, data, + pfd->visited, + pfd->include_nondeduced_p)) + return error_mark_node; + break; + + case FUNCTION_DECL: + case VAR_DECL: + if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t) + && for_each_template_parm (DECL_TI_ARGS (t), fn, data, + pfd->visited, pfd->include_nondeduced_p)) + return error_mark_node; + /* Fall through. */ + + case PARM_DECL: + case CONST_DECL: + if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t) + && for_each_template_parm (DECL_INITIAL (t), fn, data, + pfd->visited, pfd->include_nondeduced_p)) + return error_mark_node; + if (DECL_CONTEXT (t) + && pfd->include_nondeduced_p + && for_each_template_parm (DECL_CONTEXT (t), fn, data, + pfd->visited, pfd->include_nondeduced_p)) + return error_mark_node; + break; + + case BOUND_TEMPLATE_TEMPLATE_PARM: + /* Record template parameters such as `T' inside `TT<T>'. */ + if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited, + pfd->include_nondeduced_p)) + return error_mark_node; + /* Fall through. */ + + case TEMPLATE_TEMPLATE_PARM: + case TEMPLATE_TYPE_PARM: + case TEMPLATE_PARM_INDEX: + if (fn && (*fn)(t, data)) + return error_mark_node; + else if (!fn) + return error_mark_node; + break; + + case TEMPLATE_DECL: + /* A template template parameter is encountered. */ + if (DECL_TEMPLATE_TEMPLATE_PARM_P (t) + && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited, + pfd->include_nondeduced_p)) + return error_mark_node; + + /* Already substituted template template parameter */ + *walk_subtrees = 0; + break; + + case TYPENAME_TYPE: + if (!fn + || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn, + data, pfd->visited, + pfd->include_nondeduced_p)) + return error_mark_node; + break; + + case CONSTRUCTOR: + if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t)) + && pfd->include_nondeduced_p + && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE + (TREE_TYPE (t)), fn, data, + pfd->visited, pfd->include_nondeduced_p)) + return error_mark_node; + break; + + case INDIRECT_REF: + case COMPONENT_REF: + /* If there's no type, then this thing must be some expression + involving template parameters. */ + if (!fn && !TREE_TYPE (t)) + return error_mark_node; + break; + + case MODOP_EXPR: + case CAST_EXPR: + case IMPLICIT_CONV_EXPR: + case REINTERPRET_CAST_EXPR: + case CONST_CAST_EXPR: + case STATIC_CAST_EXPR: + case DYNAMIC_CAST_EXPR: + case ARROW_EXPR: + case DOTSTAR_EXPR: + case TYPEID_EXPR: + case PSEUDO_DTOR_EXPR: + if (!fn) + return error_mark_node; + break; + + default: + break; + } + + /* We didn't find any template parameters we liked. */ + return NULL_TREE; +} + +/* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM, + BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T, + call FN with the parameter and the DATA. + If FN returns nonzero, the iteration is terminated, and + for_each_template_parm returns 1. Otherwise, the iteration + continues. If FN never returns a nonzero value, the value + returned by for_each_template_parm is 0. If FN is NULL, it is + considered to be the function which always returns 1. + + If INCLUDE_NONDEDUCED_P, then this routine will also visit template + parameters that occur in non-deduced contexts. When false, only + visits those template parameters that can be deduced. */ + +static int +for_each_template_parm (tree t, tree_fn_t fn, void* data, + struct pointer_set_t *visited, + bool include_nondeduced_p) +{ + struct pair_fn_data pfd; + int result; + + /* Set up. */ + pfd.fn = fn; + pfd.data = data; + pfd.include_nondeduced_p = include_nondeduced_p; + + /* Walk the tree. (Conceptually, we would like to walk without + duplicates, but for_each_template_parm_r recursively calls + for_each_template_parm, so we would need to reorganize a fair + bit to use walk_tree_without_duplicates, so we keep our own + visited list.) */ + if (visited) + pfd.visited = visited; + else + pfd.visited = pointer_set_create (); + result = cp_walk_tree (&t, + for_each_template_parm_r, + &pfd, + pfd.visited) != NULL_TREE; + + /* Clean up. */ + if (!visited) + { + pointer_set_destroy (pfd.visited); + pfd.visited = 0; + } + + return result; +} + +/* Returns true if T depends on any template parameter. */ + +int +uses_template_parms (tree t) +{ + bool dependent_p; + int saved_processing_template_decl; + + saved_processing_template_decl = processing_template_decl; + if (!saved_processing_template_decl) + processing_template_decl = 1; + if (TYPE_P (t)) + dependent_p = dependent_type_p (t); + else if (TREE_CODE (t) == TREE_VEC) + dependent_p = any_dependent_template_arguments_p (t); + else if (TREE_CODE (t) == TREE_LIST) + dependent_p = (uses_template_parms (TREE_VALUE (t)) + || uses_template_parms (TREE_CHAIN (t))); + else if (TREE_CODE (t) == TYPE_DECL) + dependent_p = dependent_type_p (TREE_TYPE (t)); + else if (DECL_P (t) + || EXPR_P (t) + || TREE_CODE (t) == TEMPLATE_PARM_INDEX + || TREE_CODE (t) == OVERLOAD + || BASELINK_P (t) + || identifier_p (t) + || TREE_CODE (t) == TRAIT_EXPR + || TREE_CODE (t) == CONSTRUCTOR + || CONSTANT_CLASS_P (t)) + dependent_p = (type_dependent_expression_p (t) + || value_dependent_expression_p (t)); + else + { + gcc_assert (t == error_mark_node); + dependent_p = false; + } + + processing_template_decl = saved_processing_template_decl; + + return dependent_p; +} + +/* Returns true iff current_function_decl is an incompletely instantiated + template. Useful instead of processing_template_decl because the latter + is set to 0 during fold_non_dependent_expr. */ + +bool +in_template_function (void) +{ + tree fn = current_function_decl; + bool ret; + ++processing_template_decl; + ret = (fn && DECL_LANG_SPECIFIC (fn) + && DECL_TEMPLATE_INFO (fn) + && any_dependent_template_arguments_p (DECL_TI_ARGS (fn))); + --processing_template_decl; + return ret; +} + +/* Returns true if T depends on any template parameter with level LEVEL. */ + +int +uses_template_parms_level (tree t, int level) +{ + return for_each_template_parm (t, template_parm_this_level_p, &level, NULL, + /*include_nondeduced_p=*/true); +} + +/* Returns TRUE iff INST is an instantiation we don't need to do in an + ill-formed translation unit, i.e. a variable or function that isn't + usable in a constant expression. */ + +static inline bool +neglectable_inst_p (tree d) +{ + return (DECL_P (d) + && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d) + : decl_maybe_constant_var_p (d))); +} + +/* Returns TRUE iff we should refuse to instantiate DECL because it's + neglectable and instantiated from within an erroneous instantiation. */ + +static bool +limit_bad_template_recursion (tree decl) +{ + struct tinst_level *lev = current_tinst_level; + int errs = errorcount + sorrycount; + if (lev == NULL || errs == 0 || !neglectable_inst_p (decl)) + return false; + + for (; lev; lev = lev->next) + if (neglectable_inst_p (lev->decl)) + break; + + return (lev && errs > lev->errors); +} + +static int tinst_depth; +extern int max_tinst_depth; +int depth_reached; + +static GTY(()) struct tinst_level *last_error_tinst_level; + +/* We're starting to instantiate D; record the template instantiation context + for diagnostics and to restore it later. */ + +int +push_tinst_level (tree d) +{ + struct tinst_level *new_level; + + if (tinst_depth >= max_tinst_depth) + { + last_error_tinst_level = current_tinst_level; + if (TREE_CODE (d) == TREE_LIST) + error ("template instantiation depth exceeds maximum of %d (use " + "-ftemplate-depth= to increase the maximum) substituting %qS", + max_tinst_depth, d); + else + error ("template instantiation depth exceeds maximum of %d (use " + "-ftemplate-depth= to increase the maximum) instantiating %qD", + max_tinst_depth, d); + + print_instantiation_context (); + + return 0; + } + + /* If the current instantiation caused problems, don't let it instantiate + anything else. Do allow deduction substitution and decls usable in + constant expressions. */ + if (limit_bad_template_recursion (d)) + return 0; + + new_level = ggc_alloc_tinst_level (); + new_level->decl = d; + new_level->locus = input_location; + new_level->errors = errorcount+sorrycount; + new_level->in_system_header_p = in_system_header_at (input_location); + new_level->next = current_tinst_level; + current_tinst_level = new_level; + + ++tinst_depth; + if (GATHER_STATISTICS && (tinst_depth > depth_reached)) + depth_reached = tinst_depth; + + return 1; +} + +/* We're done instantiating this template; return to the instantiation + context. */ + +void +pop_tinst_level (void) +{ + /* Restore the filename and line number stashed away when we started + this instantiation. */ + input_location = current_tinst_level->locus; + current_tinst_level = current_tinst_level->next; + --tinst_depth; +} + +/* We're instantiating a deferred template; restore the template + instantiation context in which the instantiation was requested, which + is one step out from LEVEL. Return the corresponding DECL or TYPE. */ + +static tree +reopen_tinst_level (struct tinst_level *level) +{ + struct tinst_level *t; + + tinst_depth = 0; + for (t = level; t; t = t->next) + ++tinst_depth; + + current_tinst_level = level; + pop_tinst_level (); + if (current_tinst_level) + current_tinst_level->errors = errorcount+sorrycount; + return level->decl; +} + +/* Returns the TINST_LEVEL which gives the original instantiation + context. */ + +struct tinst_level * +outermost_tinst_level (void) +{ + struct tinst_level *level = current_tinst_level; + if (level) + while (level->next) + level = level->next; + return level; +} + +/* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the + vector of template arguments, as for tsubst. + + Returns an appropriate tsubst'd friend declaration. */ + +static tree +tsubst_friend_function (tree decl, tree args) +{ + tree new_friend; + + if (TREE_CODE (decl) == FUNCTION_DECL + && DECL_TEMPLATE_INSTANTIATION (decl) + && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL) + /* This was a friend declared with an explicit template + argument list, e.g.: + + friend void f<>(T); + + to indicate that f was a template instantiation, not a new + function declaration. Now, we have to figure out what + instantiation of what template. */ + { + tree template_id, arglist, fns; + tree new_args; + tree tmpl; + tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type)); + + /* Friend functions are looked up in the containing namespace scope. + We must enter that scope, to avoid finding member functions of the + current class with same name. */ + push_nested_namespace (ns); + fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args, + tf_warning_or_error, NULL_TREE, + /*integral_constant_expression_p=*/false); + pop_nested_namespace (ns); + arglist = tsubst (DECL_TI_ARGS (decl), args, + tf_warning_or_error, NULL_TREE); + template_id = lookup_template_function (fns, arglist); + + new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE); + tmpl = determine_specialization (template_id, new_friend, + &new_args, + /*need_member_template=*/0, + TREE_VEC_LENGTH (args), + tsk_none); + return instantiate_template (tmpl, new_args, tf_error); + } + + new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE); + + /* The NEW_FRIEND will look like an instantiation, to the + compiler, but is not an instantiation from the point of view of + the language. For example, we might have had: + + template <class T> struct S { + template <class U> friend void f(T, U); + }; + + Then, in S<int>, template <class U> void f(int, U) is not an + instantiation of anything. */ + if (new_friend == error_mark_node) + return error_mark_node; + + DECL_USE_TEMPLATE (new_friend) = 0; + if (TREE_CODE (decl) == TEMPLATE_DECL) + { + DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0; + DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend)) + = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl)); + } + + /* The mangled name for the NEW_FRIEND is incorrect. The function + is not a template instantiation and should not be mangled like + one. Therefore, we forget the mangling here; we'll recompute it + later if we need it. */ + if (TREE_CODE (new_friend) != TEMPLATE_DECL) + { + SET_DECL_RTL (new_friend, NULL); + SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE); + } + + if (DECL_NAMESPACE_SCOPE_P (new_friend)) + { + tree old_decl; + tree new_friend_template_info; + tree new_friend_result_template_info; + tree ns; + int new_friend_is_defn; + + /* We must save some information from NEW_FRIEND before calling + duplicate decls since that function will free NEW_FRIEND if + possible. */ + new_friend_template_info = DECL_TEMPLATE_INFO (new_friend); + new_friend_is_defn = + (DECL_INITIAL (DECL_TEMPLATE_RESULT + (template_for_substitution (new_friend))) + != NULL_TREE); + if (TREE_CODE (new_friend) == TEMPLATE_DECL) + { + /* This declaration is a `primary' template. */ + DECL_PRIMARY_TEMPLATE (new_friend) = new_friend; + + new_friend_result_template_info + = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend)); + } + else + new_friend_result_template_info = NULL_TREE; + + /* Make the init_value nonzero so pushdecl knows this is a defn. */ + if (new_friend_is_defn) + DECL_INITIAL (new_friend) = error_mark_node; + + /* Inside pushdecl_namespace_level, we will push into the + current namespace. However, the friend function should go + into the namespace of the template. */ + ns = decl_namespace_context (new_friend); + push_nested_namespace (ns); + old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true); + pop_nested_namespace (ns); + + if (old_decl == error_mark_node) + return error_mark_node; + + if (old_decl != new_friend) + { + /* This new friend declaration matched an existing + declaration. For example, given: + + template <class T> void f(T); + template <class U> class C { + template <class T> friend void f(T) {} + }; + + the friend declaration actually provides the definition + of `f', once C has been instantiated for some type. So, + old_decl will be the out-of-class template declaration, + while new_friend is the in-class definition. + + But, if `f' was called before this point, the + instantiation of `f' will have DECL_TI_ARGS corresponding + to `T' but not to `U', references to which might appear + in the definition of `f'. Previously, the most general + template for an instantiation of `f' was the out-of-class + version; now it is the in-class version. Therefore, we + run through all specialization of `f', adding to their + DECL_TI_ARGS appropriately. In particular, they need a + new set of outer arguments, corresponding to the + arguments for this class instantiation. + + The same situation can arise with something like this: + + friend void f(int); + template <class T> class C { + friend void f(T) {} + }; + + when `C<int>' is instantiated. Now, `f(int)' is defined + in the class. */ + + if (!new_friend_is_defn) + /* On the other hand, if the in-class declaration does + *not* provide a definition, then we don't want to alter + existing definitions. We can just leave everything + alone. */ + ; + else + { + tree new_template = TI_TEMPLATE (new_friend_template_info); + tree new_args = TI_ARGS (new_friend_template_info); + + /* Overwrite whatever template info was there before, if + any, with the new template information pertaining to + the declaration. */ + DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info; + + if (TREE_CODE (old_decl) != TEMPLATE_DECL) + { + /* We should have called reregister_specialization in + duplicate_decls. */ + gcc_assert (retrieve_specialization (new_template, + new_args, 0) + == old_decl); + + /* Instantiate it if the global has already been used. */ + if (DECL_ODR_USED (old_decl)) + instantiate_decl (old_decl, /*defer_ok=*/true, + /*expl_inst_class_mem_p=*/false); + } + else + { + tree t; + + /* Indicate that the old function template is a partial + instantiation. */ + DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl)) + = new_friend_result_template_info; + + gcc_assert (new_template + == most_general_template (new_template)); + gcc_assert (new_template != old_decl); + + /* Reassign any specializations already in the hash table + to the new more general template, and add the + additional template args. */ + for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl); + t != NULL_TREE; + t = TREE_CHAIN (t)) + { + tree spec = TREE_VALUE (t); + spec_entry elt; + + elt.tmpl = old_decl; + elt.args = DECL_TI_ARGS (spec); + elt.spec = NULL_TREE; + + htab_remove_elt (decl_specializations, &elt); + + DECL_TI_ARGS (spec) + = add_outermost_template_args (new_args, + DECL_TI_ARGS (spec)); + + register_specialization + (spec, new_template, DECL_TI_ARGS (spec), true, 0); + + } + DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE; + } + } + + /* The information from NEW_FRIEND has been merged into OLD_DECL + by duplicate_decls. */ + new_friend = old_decl; + } + } + else + { + tree context = DECL_CONTEXT (new_friend); + bool dependent_p; + + /* In the code + template <class T> class C { + template <class U> friend void C1<U>::f (); // case 1 + friend void C2<T>::f (); // case 2 + }; + we only need to make sure CONTEXT is a complete type for + case 2. To distinguish between the two cases, we note that + CONTEXT of case 1 remains dependent type after tsubst while + this isn't true for case 2. */ + ++processing_template_decl; + dependent_p = dependent_type_p (context); + --processing_template_decl; + + if (!dependent_p + && !complete_type_or_else (context, NULL_TREE)) + return error_mark_node; + + if (COMPLETE_TYPE_P (context)) + { + tree fn = new_friend; + /* do_friend adds the TEMPLATE_DECL for any member friend + template even if it isn't a member template, i.e. + template <class T> friend A<T>::f(); + Look through it in that case. */ + if (TREE_CODE (fn) == TEMPLATE_DECL + && !PRIMARY_TEMPLATE_P (fn)) + fn = DECL_TEMPLATE_RESULT (fn); + /* Check to see that the declaration is really present, and, + possibly obtain an improved declaration. */ + fn = check_classfn (context, fn, NULL_TREE); + + if (fn) + new_friend = fn; + } + } + + return new_friend; +} + +/* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of + template arguments, as for tsubst. + + Returns an appropriate tsubst'd friend type or error_mark_node on + failure. */ + +static tree +tsubst_friend_class (tree friend_tmpl, tree args) +{ + tree friend_type; + tree tmpl; + tree context; + + if (DECL_TEMPLATE_TEMPLATE_PARM_P (friend_tmpl)) + { + tree t = tsubst (TREE_TYPE (friend_tmpl), args, tf_none, NULL_TREE); + return TREE_TYPE (t); + } + + context = CP_DECL_CONTEXT (friend_tmpl); + + if (context != global_namespace) + { + if (TREE_CODE (context) == NAMESPACE_DECL) + push_nested_namespace (context); + else + push_nested_class (tsubst (context, args, tf_none, NULL_TREE)); + } + + /* Look for a class template declaration. We look for hidden names + because two friend declarations of the same template are the + same. For example, in: + + struct A { + template <typename> friend class F; + }; + template <typename> struct B { + template <typename> friend class F; + }; + + both F templates are the same. */ + tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0, + /*block_p=*/true, 0, LOOKUP_HIDDEN); + + /* But, if we don't find one, it might be because we're in a + situation like this: + + template <class T> + struct S { + template <class U> + friend struct S; + }; + + Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL + for `S<int>', not the TEMPLATE_DECL. */ + if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl)) + { + tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1); + tmpl = maybe_get_template_decl_from_type_decl (tmpl); + } + + if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl)) + { + /* The friend template has already been declared. Just + check to see that the declarations match, and install any new + default parameters. We must tsubst the default parameters, + of course. We only need the innermost template parameters + because that is all that redeclare_class_template will look + at. */ + if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl)) + > TMPL_ARGS_DEPTH (args)) + { + tree parms; + location_t saved_input_location; + parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl), + args, tf_warning_or_error); + + saved_input_location = input_location; + input_location = DECL_SOURCE_LOCATION (friend_tmpl); + redeclare_class_template (TREE_TYPE (tmpl), parms); + input_location = saved_input_location; + + } + + friend_type = TREE_TYPE (tmpl); + } + else + { + /* The friend template has not already been declared. In this + case, the instantiation of the template class will cause the + injection of this template into the global scope. */ + tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE); + if (tmpl == error_mark_node) + return error_mark_node; + + /* The new TMPL is not an instantiation of anything, so we + forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for + the new type because that is supposed to be the corresponding + template decl, i.e., TMPL. */ + DECL_USE_TEMPLATE (tmpl) = 0; + DECL_TEMPLATE_INFO (tmpl) = NULL_TREE; + CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0; + CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)) + = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))); + + /* Inject this template into the global scope. */ + friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true)); + } + + if (context != global_namespace) + { + if (TREE_CODE (context) == NAMESPACE_DECL) + pop_nested_namespace (context); + else + pop_nested_class (); + } + + return friend_type; +} + +/* Returns zero if TYPE cannot be completed later due to circularity. + Otherwise returns one. */ + +static int +can_complete_type_without_circularity (tree type) +{ + if (type == NULL_TREE || type == error_mark_node) + return 0; + else if (COMPLETE_TYPE_P (type)) + return 1; + else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type)) + return can_complete_type_without_circularity (TREE_TYPE (type)); + else if (CLASS_TYPE_P (type) + && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type))) + return 0; + else + return 1; +} + +static tree tsubst_omp_clauses (tree, bool, tree, tsubst_flags_t, tree); + +/* Apply any attributes which had to be deferred until instantiation + time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes; + ARGS, COMPLAIN, IN_DECL are as tsubst. */ + +static void +apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags, + tree args, tsubst_flags_t complain, tree in_decl) +{ + tree last_dep = NULL_TREE; + tree t; + tree *p; + + for (t = attributes; t; t = TREE_CHAIN (t)) + if (ATTR_IS_DEPENDENT (t)) + { + last_dep = t; + attributes = copy_list (attributes); + break; + } + + if (DECL_P (*decl_p)) + { + if (TREE_TYPE (*decl_p) == error_mark_node) + return; + p = &DECL_ATTRIBUTES (*decl_p); + } + else + p = &TYPE_ATTRIBUTES (*decl_p); + + if (last_dep) + { + tree late_attrs = NULL_TREE; + tree *q = &late_attrs; + + for (*p = attributes; *p; ) + { + t = *p; + if (ATTR_IS_DEPENDENT (t)) + { + *p = TREE_CHAIN (t); + TREE_CHAIN (t) = NULL_TREE; + if ((flag_openmp || flag_cilkplus) + && is_attribute_p ("omp declare simd", + get_attribute_name (t)) + && TREE_VALUE (t)) + { + tree clauses = TREE_VALUE (TREE_VALUE (t)); + clauses = tsubst_omp_clauses (clauses, true, args, + complain, in_decl); + c_omp_declare_simd_clauses_to_decls (*decl_p, clauses); + clauses = finish_omp_clauses (clauses); + tree parms = DECL_ARGUMENTS (*decl_p); + clauses + = c_omp_declare_simd_clauses_to_numbers (parms, clauses); + if (clauses) + TREE_VALUE (TREE_VALUE (t)) = clauses; + else + TREE_VALUE (t) = NULL_TREE; + } + /* If the first attribute argument is an identifier, don't + pass it through tsubst. Attributes like mode, format, + cleanup and several target specific attributes expect it + unmodified. */ + else if (attribute_takes_identifier_p (get_attribute_name (t)) + && TREE_VALUE (t)) + { + tree chain + = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain, + in_decl, + /*integral_constant_expression_p=*/false); + if (chain != TREE_CHAIN (TREE_VALUE (t))) + TREE_VALUE (t) + = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)), + chain); + } + else + TREE_VALUE (t) + = tsubst_expr (TREE_VALUE (t), args, complain, in_decl, + /*integral_constant_expression_p=*/false); + *q = t; + q = &TREE_CHAIN (t); + } + else + p = &TREE_CHAIN (t); + } + + cplus_decl_attributes (decl_p, late_attrs, attr_flags); + } +} + +/* Perform (or defer) access check for typedefs that were referenced + from within the template TMPL code. + This is a subroutine of instantiate_decl and instantiate_class_template. + TMPL is the template to consider and TARGS is the list of arguments of + that template. */ + +static void +perform_typedefs_access_check (tree tmpl, tree targs) +{ + location_t saved_location; + unsigned i; + qualified_typedef_usage_t *iter; + + if (!tmpl + || (!CLASS_TYPE_P (tmpl) + && TREE_CODE (tmpl) != FUNCTION_DECL)) + return; + + saved_location = input_location; + FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (tmpl), i, iter) + { + tree type_decl = iter->typedef_decl; + tree type_scope = iter->context; + + if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope)) + continue; + + if (uses_template_parms (type_decl)) + type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE); + if (uses_template_parms (type_scope)) + type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE); + + /* Make access check error messages point to the location + of the use of the typedef. */ + input_location = iter->locus; + perform_or_defer_access_check (TYPE_BINFO (type_scope), + type_decl, type_decl, + tf_warning_or_error); + } + input_location = saved_location; +} + +static tree +instantiate_class_template_1 (tree type) +{ + tree templ, args, pattern, t, member; + tree typedecl; + tree pbinfo; + tree base_list; + unsigned int saved_maximum_field_alignment; + tree fn_context; + + if (type == error_mark_node) + return error_mark_node; + + if (COMPLETE_OR_OPEN_TYPE_P (type) + || uses_template_parms (type)) + return type; + + /* Figure out which template is being instantiated. */ + templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type)); + gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL); + + /* Determine what specialization of the original template to + instantiate. */ + t = most_specialized_class (type, tf_warning_or_error); + if (t == error_mark_node) + { + TYPE_BEING_DEFINED (type) = 1; + return error_mark_node; + } + else if (t) + { + /* This TYPE is actually an instantiation of a partial + specialization. We replace the innermost set of ARGS with + the arguments appropriate for substitution. For example, + given: + + template <class T> struct S {}; + template <class T> struct S<T*> {}; + + and supposing that we are instantiating S<int*>, ARGS will + presently be {int*} -- but we need {int}. */ + pattern = TREE_TYPE (t); + args = TREE_PURPOSE (t); + } + else + { + pattern = TREE_TYPE (templ); + args = CLASSTYPE_TI_ARGS (type); + } + + /* If the template we're instantiating is incomplete, then clearly + there's nothing we can do. */ + if (!COMPLETE_TYPE_P (pattern)) + return type; + + /* If we've recursively instantiated too many templates, stop. */ + if (! push_tinst_level (type)) + return type; + + /* Now we're really doing the instantiation. Mark the type as in + the process of being defined. */ + TYPE_BEING_DEFINED (type) = 1; + + /* We may be in the middle of deferred access check. Disable + it now. */ + push_deferring_access_checks (dk_no_deferred); + + fn_context = decl_function_context (TYPE_MAIN_DECL (type)); + if (!fn_context) + push_to_top_level (); + /* Use #pragma pack from the template context. */ + saved_maximum_field_alignment = maximum_field_alignment; + maximum_field_alignment = TYPE_PRECISION (pattern); + + SET_CLASSTYPE_INTERFACE_UNKNOWN (type); + + /* Set the input location to the most specialized template definition. + This is needed if tsubsting causes an error. */ + typedecl = TYPE_MAIN_DECL (pattern); + input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) = + DECL_SOURCE_LOCATION (typedecl); + + TYPE_PACKED (type) = TYPE_PACKED (pattern); + TYPE_ALIGN (type) = TYPE_ALIGN (pattern); + TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern); + TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */ + if (ANON_AGGR_TYPE_P (pattern)) + SET_ANON_AGGR_TYPE_P (type); + if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern)) + { + CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1; + CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern); + /* Adjust visibility for template arguments. */ + determine_visibility (TYPE_MAIN_DECL (type)); + } + if (CLASS_TYPE_P (type)) + CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern); + + pbinfo = TYPE_BINFO (pattern); + + /* We should never instantiate a nested class before its enclosing + class; we need to look up the nested class by name before we can + instantiate it, and that lookup should instantiate the enclosing + class. */ + gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern)) + || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type))); + + base_list = NULL_TREE; + if (BINFO_N_BASE_BINFOS (pbinfo)) + { + tree pbase_binfo; + tree pushed_scope; + int i; + + /* We must enter the scope containing the type, as that is where + the accessibility of types named in dependent bases are + looked up from. */ + pushed_scope = push_scope (CP_TYPE_CONTEXT (type)); + + /* Substitute into each of the bases to determine the actual + basetypes. */ + for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++) + { + tree base; + tree access = BINFO_BASE_ACCESS (pbinfo, i); + tree expanded_bases = NULL_TREE; + int idx, len = 1; + + if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo))) + { + expanded_bases = + tsubst_pack_expansion (BINFO_TYPE (pbase_binfo), + args, tf_error, NULL_TREE); + if (expanded_bases == error_mark_node) + continue; + + len = TREE_VEC_LENGTH (expanded_bases); + } + + for (idx = 0; idx < len; idx++) + { + if (expanded_bases) + /* Extract the already-expanded base class. */ + base = TREE_VEC_ELT (expanded_bases, idx); + else + /* Substitute to figure out the base class. */ + base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error, + NULL_TREE); + + if (base == error_mark_node) + continue; + + base_list = tree_cons (access, base, base_list); + if (BINFO_VIRTUAL_P (pbase_binfo)) + TREE_TYPE (base_list) = integer_type_node; + } + } + + /* The list is now in reverse order; correct that. */ + base_list = nreverse (base_list); + + if (pushed_scope) + pop_scope (pushed_scope); + } + /* Now call xref_basetypes to set up all the base-class + information. */ + xref_basetypes (type, base_list); + + apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern), + (int) ATTR_FLAG_TYPE_IN_PLACE, + args, tf_error, NULL_TREE); + fixup_attribute_variants (type); + + /* Now that our base classes are set up, enter the scope of the + class, so that name lookups into base classes, etc. will work + correctly. This is precisely analogous to what we do in + begin_class_definition when defining an ordinary non-template + class, except we also need to push the enclosing classes. */ + push_nested_class (type); + + /* Now members are processed in the order of declaration. */ + for (member = CLASSTYPE_DECL_LIST (pattern); + member; member = TREE_CHAIN (member)) + { + tree t = TREE_VALUE (member); + + if (TREE_PURPOSE (member)) + { + if (TYPE_P (t)) + { + /* Build new CLASSTYPE_NESTED_UTDS. */ + + tree newtag; + bool class_template_p; + + class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE + && TYPE_LANG_SPECIFIC (t) + && CLASSTYPE_IS_TEMPLATE (t)); + /* If the member is a class template, then -- even after + substitution -- there may be dependent types in the + template argument list for the class. We increment + PROCESSING_TEMPLATE_DECL so that dependent_type_p, as + that function will assume that no types are dependent + when outside of a template. */ + if (class_template_p) + ++processing_template_decl; + newtag = tsubst (t, args, tf_error, NULL_TREE); + if (class_template_p) + --processing_template_decl; + if (newtag == error_mark_node) + continue; + + if (TREE_CODE (newtag) != ENUMERAL_TYPE) + { + tree name = TYPE_IDENTIFIER (t); + + if (class_template_p) + /* Unfortunately, lookup_template_class sets + CLASSTYPE_IMPLICIT_INSTANTIATION for a partial + instantiation (i.e., for the type of a member + template class nested within a template class.) + This behavior is required for + maybe_process_partial_specialization to work + correctly, but is not accurate in this case; + the TAG is not an instantiation of anything. + (The corresponding TEMPLATE_DECL is an + instantiation, but the TYPE is not.) */ + CLASSTYPE_USE_TEMPLATE (newtag) = 0; + + /* Now, we call pushtag to put this NEWTAG into the scope of + TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid + pushtag calling push_template_decl. We don't have to do + this for enums because it will already have been done in + tsubst_enum. */ + if (name) + SET_IDENTIFIER_TYPE_VALUE (name, newtag); + pushtag (name, newtag, /*tag_scope=*/ts_current); + } + } + else if (DECL_DECLARES_FUNCTION_P (t)) + { + /* Build new TYPE_METHODS. */ + tree r; + + if (TREE_CODE (t) == TEMPLATE_DECL) + ++processing_template_decl; + r = tsubst (t, args, tf_error, NULL_TREE); + if (TREE_CODE (t) == TEMPLATE_DECL) + --processing_template_decl; + set_current_access_from_decl (r); + finish_member_declaration (r); + /* Instantiate members marked with attribute used. */ + if (r != error_mark_node && DECL_PRESERVE_P (r)) + mark_used (r); + if (TREE_CODE (r) == FUNCTION_DECL + && DECL_OMP_DECLARE_REDUCTION_P (r)) + cp_check_omp_declare_reduction (r); + } + else + { + /* Build new TYPE_FIELDS. */ + if (TREE_CODE (t) == STATIC_ASSERT) + { + tree condition; + + ++c_inhibit_evaluation_warnings; + condition = + tsubst_expr (STATIC_ASSERT_CONDITION (t), args, + tf_warning_or_error, NULL_TREE, + /*integral_constant_expression_p=*/true); + --c_inhibit_evaluation_warnings; + + finish_static_assert (condition, + STATIC_ASSERT_MESSAGE (t), + STATIC_ASSERT_SOURCE_LOCATION (t), + /*member_p=*/true); + } + else if (TREE_CODE (t) != CONST_DECL) + { + tree r; + tree vec = NULL_TREE; + int len = 1; + + /* The file and line for this declaration, to + assist in error message reporting. Since we + called push_tinst_level above, we don't need to + restore these. */ + input_location = DECL_SOURCE_LOCATION (t); + + if (TREE_CODE (t) == TEMPLATE_DECL) + ++processing_template_decl; + r = tsubst (t, args, tf_warning_or_error, NULL_TREE); + if (TREE_CODE (t) == TEMPLATE_DECL) + --processing_template_decl; + + if (TREE_CODE (r) == TREE_VEC) + { + /* A capture pack became multiple fields. */ + vec = r; + len = TREE_VEC_LENGTH (vec); + } + + for (int i = 0; i < len; ++i) + { + if (vec) + r = TREE_VEC_ELT (vec, i); + if (VAR_P (r)) + { + /* In [temp.inst]: + + [t]he initialization (and any associated + side-effects) of a static data member does + not occur unless the static data member is + itself used in a way that requires the + definition of the static data member to + exist. + + Therefore, we do not substitute into the + initialized for the static data member here. */ + finish_static_data_member_decl + (r, + /*init=*/NULL_TREE, + /*init_const_expr_p=*/false, + /*asmspec_tree=*/NULL_TREE, + /*flags=*/0); + /* Instantiate members marked with attribute used. */ + if (r != error_mark_node && DECL_PRESERVE_P (r)) + mark_used (r); + } + else if (TREE_CODE (r) == FIELD_DECL) + { + /* Determine whether R has a valid type and can be + completed later. If R is invalid, then its type + is replaced by error_mark_node. */ + tree rtype = TREE_TYPE (r); + if (can_complete_type_without_circularity (rtype)) + complete_type (rtype); + + if (!COMPLETE_TYPE_P (rtype)) + { + cxx_incomplete_type_error (r, rtype); + TREE_TYPE (r) = error_mark_node; + } + } + + /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE, + such a thing will already have been added to the field + list by tsubst_enum in finish_member_declaration in the + CLASSTYPE_NESTED_UTDS case above. */ + if (!(TREE_CODE (r) == TYPE_DECL + && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE + && DECL_ARTIFICIAL (r))) + { + set_current_access_from_decl (r); + finish_member_declaration (r); + } + } + } + } + } + else + { + if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t) + || DECL_TEMPLATE_TEMPLATE_PARM_P (t)) + { + /* Build new CLASSTYPE_FRIEND_CLASSES. */ + + tree friend_type = t; + bool adjust_processing_template_decl = false; + + if (TREE_CODE (friend_type) == TEMPLATE_DECL) + { + /* template <class T> friend class C; */ + friend_type = tsubst_friend_class (friend_type, args); + adjust_processing_template_decl = true; + } + else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE) + { + /* template <class T> friend class C::D; */ + friend_type = tsubst (friend_type, args, + tf_warning_or_error, NULL_TREE); + if (TREE_CODE (friend_type) == TEMPLATE_DECL) + friend_type = TREE_TYPE (friend_type); + adjust_processing_template_decl = true; + } + else if (TREE_CODE (friend_type) == TYPENAME_TYPE + || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM) + { + /* This could be either + + friend class T::C; + + when dependent_type_p is false or + + template <class U> friend class T::C; + + otherwise. */ + friend_type = tsubst (friend_type, args, + tf_warning_or_error, NULL_TREE); + /* Bump processing_template_decl for correct + dependent_type_p calculation. */ + ++processing_template_decl; + if (dependent_type_p (friend_type)) + adjust_processing_template_decl = true; + --processing_template_decl; + } + else if (!CLASSTYPE_USE_TEMPLATE (friend_type) + && hidden_name_p (TYPE_NAME (friend_type))) + { + /* friend class C; + + where C hasn't been declared yet. Let's lookup name + from namespace scope directly, bypassing any name that + come from dependent base class. */ + tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type)); + + /* The call to xref_tag_from_type does injection for friend + classes. */ + push_nested_namespace (ns); + friend_type = + xref_tag_from_type (friend_type, NULL_TREE, + /*tag_scope=*/ts_current); + pop_nested_namespace (ns); + } + else if (uses_template_parms (friend_type)) + /* friend class C<T>; */ + friend_type = tsubst (friend_type, args, + tf_warning_or_error, NULL_TREE); + /* Otherwise it's + + friend class C; + + where C is already declared or + + friend class C<int>; + + We don't have to do anything in these cases. */ + + if (adjust_processing_template_decl) + /* Trick make_friend_class into realizing that the friend + we're adding is a template, not an ordinary class. It's + important that we use make_friend_class since it will + perform some error-checking and output cross-reference + information. */ + ++processing_template_decl; + + if (friend_type != error_mark_node) + make_friend_class (type, friend_type, /*complain=*/false); + + if (adjust_processing_template_decl) + --processing_template_decl; + } + else + { + /* Build new DECL_FRIENDLIST. */ + tree r; + + /* The file and line for this declaration, to + assist in error message reporting. Since we + called push_tinst_level above, we don't need to + restore these. */ + input_location = DECL_SOURCE_LOCATION (t); + + if (TREE_CODE (t) == TEMPLATE_DECL) + { + ++processing_template_decl; + push_deferring_access_checks (dk_no_check); + } + + r = tsubst_friend_function (t, args); + add_friend (type, r, /*complain=*/false); + if (TREE_CODE (t) == TEMPLATE_DECL) + { + pop_deferring_access_checks (); + --processing_template_decl; + } + } + } + } + + if (tree expr = CLASSTYPE_LAMBDA_EXPR (type)) + { + tree decl = lambda_function (type); + if (decl) + { + if (!DECL_TEMPLATE_INFO (decl) + || DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (decl)) != decl) + instantiate_decl (decl, false, false); + + /* We need to instantiate the capture list from the template + after we've instantiated the closure members, but before we + consider adding the conversion op. Also keep any captures + that may have been added during instantiation of the op(). */ + tree tmpl_expr = CLASSTYPE_LAMBDA_EXPR (pattern); + tree tmpl_cap + = tsubst_copy_and_build (LAMBDA_EXPR_CAPTURE_LIST (tmpl_expr), + args, tf_warning_or_error, NULL_TREE, + false, false); + + LAMBDA_EXPR_CAPTURE_LIST (expr) + = chainon (tmpl_cap, nreverse (LAMBDA_EXPR_CAPTURE_LIST (expr))); + + maybe_add_lambda_conv_op (type); + } + else + gcc_assert (errorcount); + } + + /* Set the file and line number information to whatever is given for + the class itself. This puts error messages involving generated + implicit functions at a predictable point, and the same point + that would be used for non-template classes. */ + input_location = DECL_SOURCE_LOCATION (typedecl); + + unreverse_member_declarations (type); + finish_struct_1 (type); + TYPE_BEING_DEFINED (type) = 0; + + /* We don't instantiate default arguments for member functions. 14.7.1: + + The implicit instantiation of a class template specialization causes + the implicit instantiation of the declarations, but not of the + definitions or default arguments, of the class member functions, + member classes, static data members and member templates.... */ + + /* Some typedefs referenced from within the template code need to be access + checked at template instantiation time, i.e now. These types were + added to the template at parsing time. Let's get those and perform + the access checks then. */ + perform_typedefs_access_check (pattern, args); + perform_deferred_access_checks (tf_warning_or_error); + pop_nested_class (); + maximum_field_alignment = saved_maximum_field_alignment; + if (!fn_context) + pop_from_top_level (); + pop_deferring_access_checks (); + pop_tinst_level (); + + /* The vtable for a template class can be emitted in any translation + unit in which the class is instantiated. When there is no key + method, however, finish_struct_1 will already have added TYPE to + the keyed_classes list. */ + if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type)) + keyed_classes = tree_cons (NULL_TREE, type, keyed_classes); + + return type; +} + +/* Wrapper for instantiate_class_template_1. */ + +tree +instantiate_class_template (tree type) +{ + tree ret; + timevar_push (TV_TEMPLATE_INST); + ret = instantiate_class_template_1 (type); + timevar_pop (TV_TEMPLATE_INST); + return ret; +} + +static tree +tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl) +{ + tree r; + + if (!t) + r = t; + else if (TYPE_P (t)) + r = tsubst (t, args, complain, in_decl); + else + { + if (!(complain & tf_warning)) + ++c_inhibit_evaluation_warnings; + r = tsubst_expr (t, args, complain, in_decl, + /*integral_constant_expression_p=*/true); + if (!(complain & tf_warning)) + --c_inhibit_evaluation_warnings; + } + return r; +} + +/* Given a function parameter pack TMPL_PARM and some function parameters + instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them + and set *SPEC_P to point at the next point in the list. */ + +static tree +extract_fnparm_pack (tree tmpl_parm, tree *spec_p) +{ + /* Collect all of the extra "packed" parameters into an + argument pack. */ + tree parmvec; + tree parmtypevec; + tree argpack = make_node (NONTYPE_ARGUMENT_PACK); + tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK); + tree spec_parm = *spec_p; + int i, len; + + for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm)) + if (tmpl_parm + && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm)) + break; + + /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */ + parmvec = make_tree_vec (len); + parmtypevec = make_tree_vec (len); + spec_parm = *spec_p; + for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm)) + { + TREE_VEC_ELT (parmvec, i) = spec_parm; + TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm); + } + + /* Build the argument packs. */ + SET_ARGUMENT_PACK_ARGS (argpack, parmvec); + SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec); + TREE_TYPE (argpack) = argtypepack; + *spec_p = spec_parm; + + return argpack; +} + +/* Give a chain SPEC_PARM of PARM_DECLs, pack them into a + NONTYPE_ARGUMENT_PACK. */ + +static tree +make_fnparm_pack (tree spec_parm) +{ + return extract_fnparm_pack (NULL_TREE, &spec_parm); +} + +/* Return true iff the Ith element of the argument pack ARG_PACK is a + pack expansion. */ + +static bool +argument_pack_element_is_expansion_p (tree arg_pack, int i) +{ + tree vec = ARGUMENT_PACK_ARGS (arg_pack); + if (i >= TREE_VEC_LENGTH (vec)) + return false; + return PACK_EXPANSION_P (TREE_VEC_ELT (vec, i)); +} + + +/* Creates and return an ARGUMENT_PACK_SELECT tree node. */ + +static tree +make_argument_pack_select (tree arg_pack, unsigned index) +{ + tree aps = make_node (ARGUMENT_PACK_SELECT); + + ARGUMENT_PACK_SELECT_FROM_PACK (aps) = arg_pack; + ARGUMENT_PACK_SELECT_INDEX (aps) = index; + + return aps; +} + +/* This is a subroutine of tsubst_pack_expansion. + + It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS + mechanism to store the (non complete list of) arguments of the + substitution and return a non substituted pack expansion, in order + to wait for when we have enough arguments to really perform the + substitution. */ + +static bool +use_pack_expansion_extra_args_p (tree parm_packs, + int arg_pack_len, + bool has_empty_arg) +{ + /* If one pack has an expansion and another pack has a normal + argument or if one pack has an empty argument and an another + one hasn't then tsubst_pack_expansion cannot perform the + substitution and need to fall back on the + PACK_EXPANSION_EXTRA mechanism. */ + if (parm_packs == NULL_TREE) + return false; + else if (has_empty_arg) + return true; + + bool has_expansion_arg = false; + for (int i = 0 ; i < arg_pack_len; ++i) + { + bool has_non_expansion_arg = false; + for (tree parm_pack = parm_packs; + parm_pack; + parm_pack = TREE_CHAIN (parm_pack)) + { + tree arg = TREE_VALUE (parm_pack); + + if (argument_pack_element_is_expansion_p (arg, i)) + has_expansion_arg = true; + else + has_non_expansion_arg = true; + } + + if (has_expansion_arg && has_non_expansion_arg) + return true; + } + return false; +} + +/* [temp.variadic]/6 says that: + + The instantiation of a pack expansion [...] + produces a list E1,E2, ..., En, where N is the number of elements + in the pack expansion parameters. + + This subroutine of tsubst_pack_expansion produces one of these Ei. + + PATTERN is the pattern of the pack expansion. PARM_PACKS is a + TREE_LIST in which each TREE_PURPOSE is a parameter pack of + PATTERN, and each TREE_VALUE is its corresponding argument pack. + INDEX is the index 'i' of the element Ei to produce. ARGS, + COMPLAIN, and IN_DECL are the same parameters as for the + tsubst_pack_expansion function. + + The function returns the resulting Ei upon successful completion, + or error_mark_node. + + Note that this function possibly modifies the ARGS parameter, so + it's the responsibility of the caller to restore it. */ + +static tree +gen_elem_of_pack_expansion_instantiation (tree pattern, + tree parm_packs, + unsigned index, + tree args /* This parm gets + modified. */, + tsubst_flags_t complain, + tree in_decl) +{ + tree t; + bool ith_elem_is_expansion = false; + + /* For each parameter pack, change the substitution of the parameter + pack to the ith argument in its argument pack, then expand the + pattern. */ + for (tree pack = parm_packs; pack; pack = TREE_CHAIN (pack)) + { + tree parm = TREE_PURPOSE (pack); + tree arg_pack = TREE_VALUE (pack); + tree aps; /* instance of ARGUMENT_PACK_SELECT. */ + + ith_elem_is_expansion |= + argument_pack_element_is_expansion_p (arg_pack, index); + + /* Select the Ith argument from the pack. */ + if (TREE_CODE (parm) == PARM_DECL + || TREE_CODE (parm) == FIELD_DECL) + { + if (index == 0) + { + aps = make_argument_pack_select (arg_pack, index); + mark_used (parm); + register_local_specialization (aps, parm); + } + else + aps = retrieve_local_specialization (parm); + } + else + { + int idx, level; + template_parm_level_and_index (parm, &level, &idx); + + if (index == 0) + { + aps = make_argument_pack_select (arg_pack, index); + /* Update the corresponding argument. */ + TMPL_ARG (args, level, idx) = aps; + } + else + /* Re-use the ARGUMENT_PACK_SELECT. */ + aps = TMPL_ARG (args, level, idx); + } + ARGUMENT_PACK_SELECT_INDEX (aps) = index; + } + + /* Substitute into the PATTERN with the (possibly altered) + arguments. */ + if (pattern == in_decl) + /* Expanding a fixed parameter pack from + coerce_template_parameter_pack. */ + t = tsubst_decl (pattern, args, complain); + else if (!TYPE_P (pattern)) + t = tsubst_expr (pattern, args, complain, in_decl, + /*integral_constant_expression_p=*/false); + else + t = tsubst (pattern, args, complain, in_decl); + + /* If the Ith argument pack element is a pack expansion, then + the Ith element resulting from the substituting is going to + be a pack expansion as well. */ + if (ith_elem_is_expansion) + t = make_pack_expansion (t); + + return t; +} + +/* Substitute ARGS into T, which is an pack expansion + (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a + TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node + (if only a partial substitution could be performed) or + ERROR_MARK_NODE if there was an error. */ +tree +tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain, + tree in_decl) +{ + tree pattern; + tree pack, packs = NULL_TREE; + bool unsubstituted_packs = false; + int i, len = -1; + tree result; + struct pointer_map_t *saved_local_specializations = NULL; + bool need_local_specializations = false; + int levels; + + gcc_assert (PACK_EXPANSION_P (t)); + pattern = PACK_EXPANSION_PATTERN (t); + + /* Add in any args remembered from an earlier partial instantiation. */ + args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args); + + levels = TMPL_ARGS_DEPTH (args); + + /* Determine the argument packs that will instantiate the parameter + packs used in the expansion expression. While we're at it, + compute the number of arguments to be expanded and make sure it + is consistent. */ + for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack; + pack = TREE_CHAIN (pack)) + { + tree parm_pack = TREE_VALUE (pack); + tree arg_pack = NULL_TREE; + tree orig_arg = NULL_TREE; + int level = 0; + + if (TREE_CODE (parm_pack) == BASES) + { + if (BASES_DIRECT (parm_pack)) + return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack), + args, complain, in_decl, false)); + else + return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack), + args, complain, in_decl, false)); + } + if (TREE_CODE (parm_pack) == PARM_DECL) + { + if (PACK_EXPANSION_LOCAL_P (t)) + arg_pack = retrieve_local_specialization (parm_pack); + else + { + /* We can't rely on local_specializations for a parameter + name used later in a function declaration (such as in a + late-specified return type). Even if it exists, it might + have the wrong value for a recursive call. Just make a + dummy decl, since it's only used for its type. */ + arg_pack = tsubst_decl (parm_pack, args, complain); + if (arg_pack && DECL_PACK_P (arg_pack)) + /* Partial instantiation of the parm_pack, we can't build + up an argument pack yet. */ + arg_pack = NULL_TREE; + else + arg_pack = make_fnparm_pack (arg_pack); + need_local_specializations = true; + } + } + else if (TREE_CODE (parm_pack) == FIELD_DECL) + arg_pack = tsubst_copy (parm_pack, args, complain, in_decl); + else + { + int idx; + template_parm_level_and_index (parm_pack, &level, &idx); + + if (level <= levels) + arg_pack = TMPL_ARG (args, level, idx); + } + + orig_arg = arg_pack; + if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT) + arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack); + + if (arg_pack && !ARGUMENT_PACK_P (arg_pack)) + /* This can only happen if we forget to expand an argument + pack somewhere else. Just return an error, silently. */ + { + result = make_tree_vec (1); + TREE_VEC_ELT (result, 0) = error_mark_node; + return result; + } + + if (arg_pack) + { + int my_len = + TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)); + + /* Don't bother trying to do a partial substitution with + incomplete packs; we'll try again after deduction. */ + if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack)) + return t; + + if (len < 0) + len = my_len; + else if (len != my_len) + { + if (!(complain & tf_error)) + /* Fail quietly. */; + else if (TREE_CODE (t) == TYPE_PACK_EXPANSION) + error ("mismatched argument pack lengths while expanding " + "%<%T%>", + pattern); + else + error ("mismatched argument pack lengths while expanding " + "%<%E%>", + pattern); + return error_mark_node; + } + + /* Keep track of the parameter packs and their corresponding + argument packs. */ + packs = tree_cons (parm_pack, arg_pack, packs); + TREE_TYPE (packs) = orig_arg; + } + else + { + /* We can't substitute for this parameter pack. We use a flag as + well as the missing_level counter because function parameter + packs don't have a level. */ + unsubstituted_packs = true; + } + } + + /* We cannot expand this expansion expression, because we don't have + all of the argument packs we need. */ + if (use_pack_expansion_extra_args_p (packs, len, unsubstituted_packs)) + { + /* We got some full packs, but we can't substitute them in until we + have values for all the packs. So remember these until then. */ + + t = make_pack_expansion (pattern); + PACK_EXPANSION_EXTRA_ARGS (t) = args; + return t; + } + else if (unsubstituted_packs) + { + /* There were no real arguments, we're just replacing a parameter + pack with another version of itself. Substitute into the + pattern and return a PACK_EXPANSION_*. The caller will need to + deal with that. */ + if (TREE_CODE (t) == EXPR_PACK_EXPANSION) + t = tsubst_expr (pattern, args, complain, in_decl, + /*integral_constant_expression_p=*/false); + else + t = tsubst (pattern, args, complain, in_decl); + t = make_pack_expansion (t); + return t; + } + + gcc_assert (len >= 0); + + if (need_local_specializations) + { + /* We're in a late-specified return type, so create our own local + specializations map; the current map is either NULL or (in the + case of recursive unification) might have bindings that we don't + want to use or alter. */ + saved_local_specializations = local_specializations; + local_specializations = pointer_map_create (); + } + + /* For each argument in each argument pack, substitute into the + pattern. */ + result = make_tree_vec (len); + for (i = 0; i < len; ++i) + { + t = gen_elem_of_pack_expansion_instantiation (pattern, packs, + i, + args, complain, + in_decl); + TREE_VEC_ELT (result, i) = t; + if (t == error_mark_node) + { + result = error_mark_node; + break; + } + } + + /* Update ARGS to restore the substitution from parameter packs to + their argument packs. */ + for (pack = packs; pack; pack = TREE_CHAIN (pack)) + { + tree parm = TREE_PURPOSE (pack); + + if (TREE_CODE (parm) == PARM_DECL + || TREE_CODE (parm) == FIELD_DECL) + register_local_specialization (TREE_TYPE (pack), parm); + else + { + int idx, level; + + if (TREE_VALUE (pack) == NULL_TREE) + continue; + + template_parm_level_and_index (parm, &level, &idx); + + /* Update the corresponding argument. */ + if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)) + TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) = + TREE_TYPE (pack); + else + TREE_VEC_ELT (args, idx) = TREE_TYPE (pack); + } + } + + if (need_local_specializations) + { + pointer_map_destroy (local_specializations); + local_specializations = saved_local_specializations; + } + + return result; +} + +/* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template + TMPL. We do this using DECL_PARM_INDEX, which should work even with + parameter packs; all parms generated from a function parameter pack will + have the same DECL_PARM_INDEX. */ + +tree +get_pattern_parm (tree parm, tree tmpl) +{ + tree pattern = DECL_TEMPLATE_RESULT (tmpl); + tree patparm; + + if (DECL_ARTIFICIAL (parm)) + { + for (patparm = DECL_ARGUMENTS (pattern); + patparm; patparm = DECL_CHAIN (patparm)) + if (DECL_ARTIFICIAL (patparm) + && DECL_NAME (parm) == DECL_NAME (patparm)) + break; + } + else + { + patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl)); + patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm); + gcc_assert (DECL_PARM_INDEX (patparm) + == DECL_PARM_INDEX (parm)); + } + + return patparm; +} + +/* Substitute ARGS into the vector or list of template arguments T. */ + +static tree +tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl) +{ + tree orig_t = t; + int len, need_new = 0, i, expanded_len_adjust = 0, out; + tree *elts; + + if (t == error_mark_node) + return error_mark_node; + + len = TREE_VEC_LENGTH (t); + elts = XALLOCAVEC (tree, len); + + for (i = 0; i < len; i++) + { + tree orig_arg = TREE_VEC_ELT (t, i); + tree new_arg; + + if (TREE_CODE (orig_arg) == TREE_VEC) + new_arg = tsubst_template_args (orig_arg, args, complain, in_decl); + else if (PACK_EXPANSION_P (orig_arg)) + { + /* Substitute into an expansion expression. */ + new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl); + + if (TREE_CODE (new_arg) == TREE_VEC) + /* Add to the expanded length adjustment the number of + expanded arguments. We subtract one from this + measurement, because the argument pack expression + itself is already counted as 1 in + LEN. EXPANDED_LEN_ADJUST can actually be negative, if + the argument pack is empty. */ + expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1; + } + else if (ARGUMENT_PACK_P (orig_arg)) + { + /* Substitute into each of the arguments. */ + new_arg = TYPE_P (orig_arg) + ? cxx_make_type (TREE_CODE (orig_arg)) + : make_node (TREE_CODE (orig_arg)); + + SET_ARGUMENT_PACK_ARGS ( + new_arg, + tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg), + args, complain, in_decl)); + + if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node) + new_arg = error_mark_node; + + if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) { + TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args, + complain, in_decl); + TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg); + + if (TREE_TYPE (new_arg) == error_mark_node) + new_arg = error_mark_node; + } + } + else + new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl); + + if (new_arg == error_mark_node) + return error_mark_node; + + elts[i] = new_arg; + if (new_arg != orig_arg) + need_new = 1; + } + + if (!need_new) + return t; + + /* Make space for the expanded arguments coming from template + argument packs. */ + t = make_tree_vec (len + expanded_len_adjust); + /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the + arguments for a member template. + In that case each TREE_VEC in ORIG_T represents a level of template + arguments, and ORIG_T won't carry any non defaulted argument count. + It will rather be the nested TREE_VECs that will carry one. + In other words, ORIG_T carries a non defaulted argument count only + if it doesn't contain any nested TREE_VEC. */ + if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t)) + { + int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t); + count += expanded_len_adjust; + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count); + } + for (i = 0, out = 0; i < len; i++) + { + if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i)) + || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i))) + && TREE_CODE (elts[i]) == TREE_VEC) + { + int idx; + + /* Now expand the template argument pack "in place". */ + for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++) + TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx); + } + else + { + TREE_VEC_ELT (t, out) = elts[i]; + out++; + } + } + + return t; +} + +/* Return the result of substituting ARGS into the template parameters + given by PARMS. If there are m levels of ARGS and m + n levels of + PARMS, then the result will contain n levels of PARMS. For + example, if PARMS is `template <class T> template <class U> + template <T*, U, class V>' and ARGS is {{int}, {double}} then the + result will be `template <int*, double, class V>'. */ + +static tree +tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain) +{ + tree r = NULL_TREE; + tree* new_parms; + + /* When substituting into a template, we must set + PROCESSING_TEMPLATE_DECL as the template parameters may be + dependent if they are based on one-another, and the dependency + predicates are short-circuit outside of templates. */ + ++processing_template_decl; + + for (new_parms = &r; + parms && TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args); + new_parms = &(TREE_CHAIN (*new_parms)), + parms = TREE_CHAIN (parms)) + { + tree new_vec = + make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms))); + int i; + + for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i) + { + tree tuple; + + if (parms == error_mark_node) + continue; + + tuple = TREE_VEC_ELT (TREE_VALUE (parms), i); + + if (tuple == error_mark_node) + continue; + + TREE_VEC_ELT (new_vec, i) = + tsubst_template_parm (tuple, args, complain); + } + + *new_parms = + tree_cons (size_int (TMPL_PARMS_DEPTH (parms) + - TMPL_ARGS_DEPTH (args)), + new_vec, NULL_TREE); + } + + --processing_template_decl; + + return r; +} + +/* Return the result of substituting ARGS into one template parameter + given by T. T Must be a TREE_LIST which TREE_VALUE is the template + parameter and which TREE_PURPOSE is the default argument of the + template parameter. */ + +static tree +tsubst_template_parm (tree t, tree args, tsubst_flags_t complain) +{ + tree default_value, parm_decl; + + if (args == NULL_TREE + || t == NULL_TREE + || t == error_mark_node) + return t; + + gcc_assert (TREE_CODE (t) == TREE_LIST); + + default_value = TREE_PURPOSE (t); + parm_decl = TREE_VALUE (t); + + parm_decl = tsubst (parm_decl, args, complain, NULL_TREE); + if (TREE_CODE (parm_decl) == PARM_DECL + && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain)) + parm_decl = error_mark_node; + default_value = tsubst_template_arg (default_value, args, + complain, NULL_TREE); + + return build_tree_list (default_value, parm_decl); +} + +/* Substitute the ARGS into the indicated aggregate (or enumeration) + type T. If T is not an aggregate or enumeration type, it is + handled as if by tsubst. IN_DECL is as for tsubst. If + ENTERING_SCOPE is nonzero, T is the context for a template which + we are presently tsubst'ing. Return the substituted value. */ + +static tree +tsubst_aggr_type (tree t, + tree args, + tsubst_flags_t complain, + tree in_decl, + int entering_scope) +{ + if (t == NULL_TREE) + return NULL_TREE; + + switch (TREE_CODE (t)) + { + case RECORD_TYPE: + if (TYPE_PTRMEMFUNC_P (t)) + return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl); + + /* Else fall through. */ + case ENUMERAL_TYPE: + case UNION_TYPE: + if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t)) + { + tree argvec; + tree context; + tree r; + int saved_unevaluated_operand; + int saved_inhibit_evaluation_warnings; + + /* In "sizeof(X<I>)" we need to evaluate "I". */ + saved_unevaluated_operand = cp_unevaluated_operand; + cp_unevaluated_operand = 0; + saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings; + c_inhibit_evaluation_warnings = 0; + + /* First, determine the context for the type we are looking + up. */ + context = TYPE_CONTEXT (t); + if (context && TYPE_P (context)) + { + context = tsubst_aggr_type (context, args, complain, + in_decl, /*entering_scope=*/1); + /* If context is a nested class inside a class template, + it may still need to be instantiated (c++/33959). */ + context = complete_type (context); + } + + /* Then, figure out what arguments are appropriate for the + type we are trying to find. For example, given: + + template <class T> struct S; + template <class T, class U> void f(T, U) { S<U> su; } + + and supposing that we are instantiating f<int, double>, + then our ARGS will be {int, double}, but, when looking up + S we only want {double}. */ + argvec = tsubst_template_args (TYPE_TI_ARGS (t), args, + complain, in_decl); + if (argvec == error_mark_node) + r = error_mark_node; + else + { + r = lookup_template_class (t, argvec, in_decl, context, + entering_scope, complain); + r = cp_build_qualified_type_real (r, cp_type_quals (t), complain); + } + + cp_unevaluated_operand = saved_unevaluated_operand; + c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings; + + return r; + } + else + /* This is not a template type, so there's nothing to do. */ + return t; + + default: + return tsubst (t, args, complain, in_decl); + } +} + +/* Substitute into the default argument ARG (a default argument for + FN), which has the indicated TYPE. */ + +tree +tsubst_default_argument (tree fn, tree type, tree arg, tsubst_flags_t complain) +{ + tree saved_class_ptr = NULL_TREE; + tree saved_class_ref = NULL_TREE; + int errs = errorcount + sorrycount; + + /* This can happen in invalid code. */ + if (TREE_CODE (arg) == DEFAULT_ARG) + return arg; + + /* This default argument came from a template. Instantiate the + default argument here, not in tsubst. In the case of + something like: + + template <class T> + struct S { + static T t(); + void f(T = t()); + }; + + we must be careful to do name lookup in the scope of S<T>, + rather than in the current class. */ + push_access_scope (fn); + /* The "this" pointer is not valid in a default argument. */ + if (cfun) + { + saved_class_ptr = current_class_ptr; + cp_function_chain->x_current_class_ptr = NULL_TREE; + saved_class_ref = current_class_ref; + cp_function_chain->x_current_class_ref = NULL_TREE; + } + + push_deferring_access_checks(dk_no_deferred); + /* The default argument expression may cause implicitly defined + member functions to be synthesized, which will result in garbage + collection. We must treat this situation as if we were within + the body of function so as to avoid collecting live data on the + stack. */ + ++function_depth; + arg = tsubst_expr (arg, DECL_TI_ARGS (fn), + complain, NULL_TREE, + /*integral_constant_expression_p=*/false); + --function_depth; + pop_deferring_access_checks(); + + /* Restore the "this" pointer. */ + if (cfun) + { + cp_function_chain->x_current_class_ptr = saved_class_ptr; + cp_function_chain->x_current_class_ref = saved_class_ref; + } + + if (errorcount+sorrycount > errs + && (complain & tf_warning_or_error)) + inform (input_location, + " when instantiating default argument for call to %D", fn); + + /* Make sure the default argument is reasonable. */ + arg = check_default_argument (type, arg, complain); + + pop_access_scope (fn); + + return arg; +} + +/* Substitute into all the default arguments for FN. */ + +static void +tsubst_default_arguments (tree fn, tsubst_flags_t complain) +{ + tree arg; + tree tmpl_args; + + tmpl_args = DECL_TI_ARGS (fn); + + /* If this function is not yet instantiated, we certainly don't need + its default arguments. */ + if (uses_template_parms (tmpl_args)) + return; + /* Don't do this again for clones. */ + if (DECL_CLONED_FUNCTION_P (fn)) + return; + + for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn)); + arg; + arg = TREE_CHAIN (arg)) + if (TREE_PURPOSE (arg)) + TREE_PURPOSE (arg) = tsubst_default_argument (fn, + TREE_VALUE (arg), + TREE_PURPOSE (arg), + complain); +} + +/* Substitute the ARGS into the T, which is a _DECL. Return the + result of the substitution. Issue error and warning messages under + control of COMPLAIN. */ + +static tree +tsubst_decl (tree t, tree args, tsubst_flags_t complain) +{ +#define RETURN(EXP) do { r = (EXP); goto out; } while(0) + location_t saved_loc; + tree r = NULL_TREE; + tree in_decl = t; + hashval_t hash = 0; + + /* Set the filename and linenumber to improve error-reporting. */ + saved_loc = input_location; + input_location = DECL_SOURCE_LOCATION (t); + + switch (TREE_CODE (t)) + { + case TEMPLATE_DECL: + { + /* We can get here when processing a member function template, + member class template, or template template parameter. */ + tree decl = DECL_TEMPLATE_RESULT (t); + tree spec; + tree tmpl_args; + tree full_args; + + if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)) + { + /* Template template parameter is treated here. */ + tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl); + if (new_type == error_mark_node) + RETURN (error_mark_node); + /* If we get a real template back, return it. This can happen in + the context of most_specialized_class. */ + if (TREE_CODE (new_type) == TEMPLATE_DECL) + return new_type; + + r = copy_decl (t); + DECL_CHAIN (r) = NULL_TREE; + TREE_TYPE (r) = new_type; + DECL_TEMPLATE_RESULT (r) + = build_decl (DECL_SOURCE_LOCATION (decl), + TYPE_DECL, DECL_NAME (decl), new_type); + DECL_TEMPLATE_PARMS (r) + = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args, + complain); + TYPE_NAME (new_type) = r; + break; + } + + /* We might already have an instance of this template. + The ARGS are for the surrounding class type, so the + full args contain the tsubst'd args for the context, + plus the innermost args from the template decl. */ + tmpl_args = DECL_CLASS_TEMPLATE_P (t) + ? CLASSTYPE_TI_ARGS (TREE_TYPE (t)) + : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t)); + /* Because this is a template, the arguments will still be + dependent, even after substitution. If + PROCESSING_TEMPLATE_DECL is not set, the dependency + predicates will short-circuit. */ + ++processing_template_decl; + full_args = tsubst_template_args (tmpl_args, args, + complain, in_decl); + --processing_template_decl; + if (full_args == error_mark_node) + RETURN (error_mark_node); + + /* If this is a default template template argument, + tsubst might not have changed anything. */ + if (full_args == tmpl_args) + RETURN (t); + + hash = hash_tmpl_and_args (t, full_args); + spec = retrieve_specialization (t, full_args, hash); + if (spec != NULL_TREE) + { + r = spec; + break; + } + + /* Make a new template decl. It will be similar to the + original, but will record the current template arguments. + We also create a new function declaration, which is just + like the old one, but points to this new template, rather + than the old one. */ + r = copy_decl (t); + gcc_assert (DECL_LANG_SPECIFIC (r) != 0); + DECL_CHAIN (r) = NULL_TREE; + + DECL_TEMPLATE_INFO (r) = build_template_info (t, args); + + if (TREE_CODE (decl) == TYPE_DECL + && !TYPE_DECL_ALIAS_P (decl)) + { + tree new_type; + ++processing_template_decl; + new_type = tsubst (TREE_TYPE (t), args, complain, in_decl); + --processing_template_decl; + if (new_type == error_mark_node) + RETURN (error_mark_node); + + TREE_TYPE (r) = new_type; + /* For a partial specialization, we need to keep pointing to + the primary template. */ + if (!DECL_TEMPLATE_SPECIALIZATION (t)) + CLASSTYPE_TI_TEMPLATE (new_type) = r; + DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type); + DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type); + DECL_CONTEXT (r) = TYPE_CONTEXT (new_type); + } + else + { + tree new_decl; + ++processing_template_decl; + new_decl = tsubst (decl, args, complain, in_decl); + --processing_template_decl; + if (new_decl == error_mark_node) + RETURN (error_mark_node); + + DECL_TEMPLATE_RESULT (r) = new_decl; + DECL_TI_TEMPLATE (new_decl) = r; + TREE_TYPE (r) = TREE_TYPE (new_decl); + DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl); + DECL_CONTEXT (r) = DECL_CONTEXT (new_decl); + } + + SET_DECL_IMPLICIT_INSTANTIATION (r); + DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE; + DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE; + + /* The template parameters for this new template are all the + template parameters for the old template, except the + outermost level of parameters. */ + DECL_TEMPLATE_PARMS (r) + = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args, + complain); + + if (PRIMARY_TEMPLATE_P (t)) + DECL_PRIMARY_TEMPLATE (r) = r; + + if (TREE_CODE (decl) != TYPE_DECL) + /* Record this non-type partial instantiation. */ + register_specialization (r, t, + DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)), + false, hash); + } + break; + + case FUNCTION_DECL: + { + tree ctx; + tree argvec = NULL_TREE; + tree *friends; + tree gen_tmpl; + tree type; + int member; + int args_depth; + int parms_depth; + + /* Nobody should be tsubst'ing into non-template functions. */ + gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE); + + if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL) + { + tree spec; + bool dependent_p; + + /* If T is not dependent, just return it. We have to + increment PROCESSING_TEMPLATE_DECL because + value_dependent_expression_p assumes that nothing is + dependent when PROCESSING_TEMPLATE_DECL is zero. */ + ++processing_template_decl; + dependent_p = value_dependent_expression_p (t); + --processing_template_decl; + if (!dependent_p) + RETURN (t); + + /* Calculate the most general template of which R is a + specialization, and the complete set of arguments used to + specialize R. */ + gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t)); + argvec = tsubst_template_args (DECL_TI_ARGS + (DECL_TEMPLATE_RESULT + (DECL_TI_TEMPLATE (t))), + args, complain, in_decl); + if (argvec == error_mark_node) + RETURN (error_mark_node); + + /* Check to see if we already have this specialization. */ + hash = hash_tmpl_and_args (gen_tmpl, argvec); + spec = retrieve_specialization (gen_tmpl, argvec, hash); + + if (spec) + { + r = spec; + break; + } + + /* We can see more levels of arguments than parameters if + there was a specialization of a member template, like + this: + + template <class T> struct S { template <class U> void f(); } + template <> template <class U> void S<int>::f(U); + + Here, we'll be substituting into the specialization, + because that's where we can find the code we actually + want to generate, but we'll have enough arguments for + the most general template. + + We also deal with the peculiar case: + + template <class T> struct S { + template <class U> friend void f(); + }; + template <class U> void f() {} + template S<int>; + template void f<double>(); + + Here, the ARGS for the instantiation of will be {int, + double}. But, we only need as many ARGS as there are + levels of template parameters in CODE_PATTERN. We are + careful not to get fooled into reducing the ARGS in + situations like: + + template <class T> struct S { template <class U> void f(U); } + template <class T> template <> void S<T>::f(int) {} + + which we can spot because the pattern will be a + specialization in this case. */ + args_depth = TMPL_ARGS_DEPTH (args); + parms_depth = + TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t))); + if (args_depth > parms_depth + && !DECL_TEMPLATE_SPECIALIZATION (t)) + args = get_innermost_template_args (args, parms_depth); + } + else + { + /* This special case arises when we have something like this: + + template <class T> struct S { + friend void f<int>(int, double); + }; + + Here, the DECL_TI_TEMPLATE for the friend declaration + will be an IDENTIFIER_NODE. We are being called from + tsubst_friend_function, and we want only to create a + new decl (R) with appropriate types so that we can call + determine_specialization. */ + gen_tmpl = NULL_TREE; + } + + if (DECL_CLASS_SCOPE_P (t)) + { + if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t))) + member = 2; + else + member = 1; + ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, + complain, t, /*entering_scope=*/1); + } + else + { + member = 0; + ctx = DECL_CONTEXT (t); + } + type = tsubst (TREE_TYPE (t), args, complain, in_decl); + if (type == error_mark_node) + RETURN (error_mark_node); + + /* If we hit excessive deduction depth, the type is bogus even if + it isn't error_mark_node, so don't build a decl. */ + if (excessive_deduction_depth) + RETURN (error_mark_node); + + /* We do NOT check for matching decls pushed separately at this + point, as they may not represent instantiations of this + template, and in any case are considered separate under the + discrete model. */ + r = copy_decl (t); + DECL_USE_TEMPLATE (r) = 0; + TREE_TYPE (r) = type; + /* Clear out the mangled name and RTL for the instantiation. */ + SET_DECL_ASSEMBLER_NAME (r, NULL_TREE); + SET_DECL_RTL (r, NULL); + /* Leave DECL_INITIAL set on deleted instantiations. */ + if (!DECL_DELETED_FN (r)) + DECL_INITIAL (r) = NULL_TREE; + DECL_CONTEXT (r) = ctx; + + /* OpenMP UDRs have the only argument a reference to the declared + type. We want to diagnose if the declared type is a reference, + which is invalid, but as references to references are usually + quietly merged, diagnose it here. */ + if (DECL_OMP_DECLARE_REDUCTION_P (t)) + { + tree argtype + = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (t)))); + argtype = tsubst (argtype, args, complain, in_decl); + if (TREE_CODE (argtype) == REFERENCE_TYPE) + error_at (DECL_SOURCE_LOCATION (t), + "reference type %qT in " + "%<#pragma omp declare reduction%>", argtype); + if (strchr (IDENTIFIER_POINTER (DECL_NAME (t)), '~') == NULL) + DECL_NAME (r) = omp_reduction_id (ERROR_MARK, DECL_NAME (t), + argtype); + } + + if (member && DECL_CONV_FN_P (r)) + /* Type-conversion operator. Reconstruct the name, in + case it's the name of one of the template's parameters. */ + DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type)); + + DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args, + complain, t); + DECL_RESULT (r) = NULL_TREE; + + TREE_STATIC (r) = 0; + TREE_PUBLIC (r) = TREE_PUBLIC (t); + DECL_EXTERNAL (r) = 1; + /* If this is an instantiation of a function with internal + linkage, we already know what object file linkage will be + assigned to the instantiation. */ + DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r); + DECL_DEFER_OUTPUT (r) = 0; + DECL_CHAIN (r) = NULL_TREE; + DECL_PENDING_INLINE_INFO (r) = 0; + DECL_PENDING_INLINE_P (r) = 0; + DECL_SAVED_TREE (r) = NULL_TREE; + DECL_STRUCT_FUNCTION (r) = NULL; + TREE_USED (r) = 0; + /* We'll re-clone as appropriate in instantiate_template. */ + DECL_CLONED_FUNCTION (r) = NULL_TREE; + + /* If we aren't complaining now, return on error before we register + the specialization so that we'll complain eventually. */ + if ((complain & tf_error) == 0 + && IDENTIFIER_OPNAME_P (DECL_NAME (r)) + && !grok_op_properties (r, /*complain=*/false)) + RETURN (error_mark_node); + + /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do + this in the special friend case mentioned above where + GEN_TMPL is NULL. */ + if (gen_tmpl) + { + DECL_TEMPLATE_INFO (r) + = build_template_info (gen_tmpl, argvec); + SET_DECL_IMPLICIT_INSTANTIATION (r); + + tree new_r + = register_specialization (r, gen_tmpl, argvec, false, hash); + if (new_r != r) + /* We instantiated this while substituting into + the type earlier (template/friend54.C). */ + RETURN (new_r); + + /* We're not supposed to instantiate default arguments + until they are called, for a template. But, for a + declaration like: + + template <class T> void f () + { extern void g(int i = T()); } + + we should do the substitution when the template is + instantiated. We handle the member function case in + instantiate_class_template since the default arguments + might refer to other members of the class. */ + if (!member + && !PRIMARY_TEMPLATE_P (gen_tmpl) + && !uses_template_parms (argvec)) + tsubst_default_arguments (r, complain); + } + else + DECL_TEMPLATE_INFO (r) = NULL_TREE; + + /* Copy the list of befriending classes. */ + for (friends = &DECL_BEFRIENDING_CLASSES (r); + *friends; + friends = &TREE_CHAIN (*friends)) + { + *friends = copy_node (*friends); + TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends), + args, complain, + in_decl); + } + + if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r)) + { + maybe_retrofit_in_chrg (r); + if (DECL_CONSTRUCTOR_P (r)) + grok_ctor_properties (ctx, r); + if (DECL_INHERITED_CTOR_BASE (r)) + deduce_inheriting_ctor (r); + /* If this is an instantiation of a member template, clone it. + If it isn't, that'll be handled by + clone_constructors_and_destructors. */ + if (PRIMARY_TEMPLATE_P (gen_tmpl)) + clone_function_decl (r, /*update_method_vec_p=*/0); + } + else if ((complain & tf_error) != 0 + && IDENTIFIER_OPNAME_P (DECL_NAME (r)) + && !grok_op_properties (r, /*complain=*/true)) + RETURN (error_mark_node); + + if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t)) + SET_DECL_FRIEND_CONTEXT (r, + tsubst (DECL_FRIEND_CONTEXT (t), + args, complain, in_decl)); + + /* Possibly limit visibility based on template args. */ + DECL_VISIBILITY (r) = VISIBILITY_DEFAULT; + if (DECL_VISIBILITY_SPECIFIED (t)) + { + DECL_VISIBILITY_SPECIFIED (r) = 0; + DECL_ATTRIBUTES (r) + = remove_attribute ("visibility", DECL_ATTRIBUTES (r)); + } + determine_visibility (r); + if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r) + && !processing_template_decl) + defaulted_late_check (r); + + apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0, + args, complain, in_decl); + } + break; + + case PARM_DECL: + { + tree type = NULL_TREE; + int i, len = 1; + tree expanded_types = NULL_TREE; + tree prev_r = NULL_TREE; + tree first_r = NULL_TREE; + + if (DECL_PACK_P (t)) + { + /* If there is a local specialization that isn't a + parameter pack, it means that we're doing a "simple" + substitution from inside tsubst_pack_expansion. Just + return the local specialization (which will be a single + parm). */ + tree spec = retrieve_local_specialization (t); + if (spec + && TREE_CODE (spec) == PARM_DECL + && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION) + RETURN (spec); + + /* Expand the TYPE_PACK_EXPANSION that provides the types for + the parameters in this function parameter pack. */ + expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args, + complain, in_decl); + if (TREE_CODE (expanded_types) == TREE_VEC) + { + len = TREE_VEC_LENGTH (expanded_types); + + /* Zero-length parameter packs are boring. Just substitute + into the chain. */ + if (len == 0) + RETURN (tsubst (TREE_CHAIN (t), args, complain, + TREE_CHAIN (t))); + } + else + { + /* All we did was update the type. Make a note of that. */ + type = expanded_types; + expanded_types = NULL_TREE; + } + } + + /* Loop through all of the parameters we'll build. When T is + a function parameter pack, LEN is the number of expanded + types in EXPANDED_TYPES; otherwise, LEN is 1. */ + r = NULL_TREE; + for (i = 0; i < len; ++i) + { + prev_r = r; + r = copy_node (t); + if (DECL_TEMPLATE_PARM_P (t)) + SET_DECL_TEMPLATE_PARM_P (r); + + if (expanded_types) + /* We're on the Ith parameter of the function parameter + pack. */ + { + /* Get the Ith type. */ + type = TREE_VEC_ELT (expanded_types, i); + + /* Rename the parameter to include the index. */ + DECL_NAME (r) + = make_ith_pack_parameter_name (DECL_NAME (r), i); + } + else if (!type) + /* We're dealing with a normal parameter. */ + type = tsubst (TREE_TYPE (t), args, complain, in_decl); + + type = type_decays_to (type); + TREE_TYPE (r) = type; + cp_apply_type_quals_to_decl (cp_type_quals (type), r); + + if (DECL_INITIAL (r)) + { + if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX) + DECL_INITIAL (r) = TREE_TYPE (r); + else + DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args, + complain, in_decl); + } + + DECL_CONTEXT (r) = NULL_TREE; + + if (!DECL_TEMPLATE_PARM_P (r)) + DECL_ARG_TYPE (r) = type_passed_as (type); + + apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0, + args, complain, in_decl); + + /* Keep track of the first new parameter we + generate. That's what will be returned to the + caller. */ + if (!first_r) + first_r = r; + + /* Build a proper chain of parameters when substituting + into a function parameter pack. */ + if (prev_r) + DECL_CHAIN (prev_r) = r; + } + + /* If cp_unevaluated_operand is set, we're just looking for a + single dummy parameter, so don't keep going. */ + if (DECL_CHAIN (t) && !cp_unevaluated_operand) + DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args, + complain, DECL_CHAIN (t)); + + /* FIRST_R contains the start of the chain we've built. */ + r = first_r; + } + break; + + case FIELD_DECL: + { + tree type = NULL_TREE; + tree vec = NULL_TREE; + tree expanded_types = NULL_TREE; + int len = 1; + + if (PACK_EXPANSION_P (TREE_TYPE (t))) + { + /* This field is a lambda capture pack. Return a TREE_VEC of + the expanded fields to instantiate_class_template_1 and + store them in the specializations hash table as a + NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */ + expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args, + complain, in_decl); + if (TREE_CODE (expanded_types) == TREE_VEC) + { + len = TREE_VEC_LENGTH (expanded_types); + vec = make_tree_vec (len); + } + else + { + /* All we did was update the type. Make a note of that. */ + type = expanded_types; + expanded_types = NULL_TREE; + } + } + + for (int i = 0; i < len; ++i) + { + r = copy_decl (t); + if (expanded_types) + { + type = TREE_VEC_ELT (expanded_types, i); + DECL_NAME (r) + = make_ith_pack_parameter_name (DECL_NAME (r), i); + } + else if (!type) + type = tsubst (TREE_TYPE (t), args, complain, in_decl); + + if (type == error_mark_node) + RETURN (error_mark_node); + TREE_TYPE (r) = type; + cp_apply_type_quals_to_decl (cp_type_quals (type), r); + + if (DECL_C_BIT_FIELD (r)) + /* For bit-fields, DECL_INITIAL gives the number of bits. For + non-bit-fields DECL_INITIAL is a non-static data member + initializer, which gets deferred instantiation. */ + DECL_INITIAL (r) + = tsubst_expr (DECL_INITIAL (t), args, + complain, in_decl, + /*integral_constant_expression_p=*/true); + else if (DECL_INITIAL (t)) + { + /* Set up DECL_TEMPLATE_INFO so that we can get at the + NSDMI in perform_member_init. Still set DECL_INITIAL + so that we know there is one. */ + DECL_INITIAL (r) = void_zero_node; + gcc_assert (DECL_LANG_SPECIFIC (r) == NULL); + retrofit_lang_decl (r); + DECL_TEMPLATE_INFO (r) = build_template_info (t, args); + } + /* We don't have to set DECL_CONTEXT here; it is set by + finish_member_declaration. */ + DECL_CHAIN (r) = NULL_TREE; + + apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0, + args, complain, in_decl); + + if (vec) + TREE_VEC_ELT (vec, i) = r; + } + + if (vec) + { + r = vec; + tree pack = make_node (NONTYPE_ARGUMENT_PACK); + tree tpack = cxx_make_type (TYPE_ARGUMENT_PACK); + SET_ARGUMENT_PACK_ARGS (pack, vec); + SET_ARGUMENT_PACK_ARGS (tpack, expanded_types); + TREE_TYPE (pack) = tpack; + register_specialization (pack, t, args, false, 0); + } + } + break; + + case USING_DECL: + /* We reach here only for member using decls. We also need to check + uses_template_parms because DECL_DEPENDENT_P is not set for a + using-declaration that designates a member of the current + instantiation (c++/53549). */ + if (DECL_DEPENDENT_P (t) + || uses_template_parms (USING_DECL_SCOPE (t))) + { + tree inst_scope = tsubst_copy (USING_DECL_SCOPE (t), args, + complain, in_decl); + tree name = tsubst_copy (DECL_NAME (t), args, complain, in_decl); + r = do_class_using_decl (inst_scope, name); + if (!r) + r = error_mark_node; + else + { + TREE_PROTECTED (r) = TREE_PROTECTED (t); + TREE_PRIVATE (r) = TREE_PRIVATE (t); + } + } + else + { + r = copy_node (t); + DECL_CHAIN (r) = NULL_TREE; + } + break; + + case TYPE_DECL: + case VAR_DECL: + { + tree argvec = NULL_TREE; + tree gen_tmpl = NULL_TREE; + tree spec; + tree tmpl = NULL_TREE; + tree ctx; + tree type = NULL_TREE; + bool local_p; + + if (TREE_TYPE (t) == error_mark_node) + RETURN (error_mark_node); + + if (TREE_CODE (t) == TYPE_DECL + && t == TYPE_MAIN_DECL (TREE_TYPE (t))) + { + /* If this is the canonical decl, we don't have to + mess with instantiations, and often we can't (for + typename, template type parms and such). Note that + TYPE_NAME is not correct for the above test if + we've copied the type for a typedef. */ + type = tsubst (TREE_TYPE (t), args, complain, in_decl); + if (type == error_mark_node) + RETURN (error_mark_node); + r = TYPE_NAME (type); + break; + } + + /* Check to see if we already have the specialization we + need. */ + spec = NULL_TREE; + if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t)) + { + /* T is a static data member or namespace-scope entity. + We have to substitute into namespace-scope variables + (even though such entities are never templates) because + of cases like: + + template <class T> void f() { extern T t; } + + where the entity referenced is not known until + instantiation time. */ + local_p = false; + ctx = DECL_CONTEXT (t); + if (DECL_CLASS_SCOPE_P (t)) + { + ctx = tsubst_aggr_type (ctx, args, + complain, + in_decl, /*entering_scope=*/1); + /* If CTX is unchanged, then T is in fact the + specialization we want. That situation occurs when + referencing a static data member within in its own + class. We can use pointer equality, rather than + same_type_p, because DECL_CONTEXT is always + canonical... */ + if (ctx == DECL_CONTEXT (t) + && (TREE_CODE (t) != TYPE_DECL + /* ... unless T is a member template; in which + case our caller can be willing to create a + specialization of that template represented + by T. */ + || !(DECL_TI_TEMPLATE (t) + && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t))))) + spec = t; + } + + if (!spec) + { + tmpl = DECL_TI_TEMPLATE (t); + gen_tmpl = most_general_template (tmpl); + argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl); + if (argvec == error_mark_node) + RETURN (error_mark_node); + hash = hash_tmpl_and_args (gen_tmpl, argvec); + spec = retrieve_specialization (gen_tmpl, argvec, hash); + } + } + else + { + /* A local variable. */ + local_p = true; + /* Subsequent calls to pushdecl will fill this in. */ + ctx = NULL_TREE; + spec = retrieve_local_specialization (t); + } + /* If we already have the specialization we need, there is + nothing more to do. */ + if (spec) + { + r = spec; + break; + } + + /* Create a new node for the specialization we need. */ + r = copy_decl (t); + if (type == NULL_TREE) + { + if (is_typedef_decl (t)) + type = DECL_ORIGINAL_TYPE (t); + else + type = TREE_TYPE (t); + if (VAR_P (t) + && VAR_HAD_UNKNOWN_BOUND (t) + && type != error_mark_node) + type = strip_array_domain (type); + type = tsubst (type, args, complain, in_decl); + } + if (VAR_P (r)) + { + /* Even if the original location is out of scope, the + newly substituted one is not. */ + DECL_DEAD_FOR_LOCAL (r) = 0; + DECL_INITIALIZED_P (r) = 0; + DECL_TEMPLATE_INSTANTIATED (r) = 0; + if (type == error_mark_node) + RETURN (error_mark_node); + if (TREE_CODE (type) == FUNCTION_TYPE) + { + /* It may seem that this case cannot occur, since: + + typedef void f(); + void g() { f x; } + + declares a function, not a variable. However: + + typedef void f(); + template <typename T> void g() { T t; } + template void g<f>(); + + is an attempt to declare a variable with function + type. */ + error ("variable %qD has function type", + /* R is not yet sufficiently initialized, so we + just use its name. */ + DECL_NAME (r)); + RETURN (error_mark_node); + } + type = complete_type (type); + /* Wait until cp_finish_decl to set this again, to handle + circular dependency (template/instantiate6.C). */ + DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0; + type = check_var_type (DECL_NAME (r), type); + + if (DECL_HAS_VALUE_EXPR_P (t)) + { + tree ve = DECL_VALUE_EXPR (t); + ve = tsubst_expr (ve, args, complain, in_decl, + /*constant_expression_p=*/false); + if (REFERENCE_REF_P (ve)) + { + gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); + ve = TREE_OPERAND (ve, 0); + } + SET_DECL_VALUE_EXPR (r, ve); + } + } + else if (DECL_SELF_REFERENCE_P (t)) + SET_DECL_SELF_REFERENCE_P (r); + TREE_TYPE (r) = type; + cp_apply_type_quals_to_decl (cp_type_quals (type), r); + DECL_CONTEXT (r) = ctx; + /* Clear out the mangled name and RTL for the instantiation. */ + SET_DECL_ASSEMBLER_NAME (r, NULL_TREE); + if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL)) + SET_DECL_RTL (r, NULL); + /* The initializer must not be expanded until it is required; + see [temp.inst]. */ + DECL_INITIAL (r) = NULL_TREE; + if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL)) + SET_DECL_RTL (r, NULL); + DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0; + if (VAR_P (r)) + { + /* Possibly limit visibility based on template args. */ + DECL_VISIBILITY (r) = VISIBILITY_DEFAULT; + if (DECL_VISIBILITY_SPECIFIED (t)) + { + DECL_VISIBILITY_SPECIFIED (r) = 0; + DECL_ATTRIBUTES (r) + = remove_attribute ("visibility", DECL_ATTRIBUTES (r)); + } + determine_visibility (r); + } + + if (!local_p) + { + /* A static data member declaration is always marked + external when it is declared in-class, even if an + initializer is present. We mimic the non-template + processing here. */ + DECL_EXTERNAL (r) = 1; + + register_specialization (r, gen_tmpl, argvec, false, hash); + DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec); + SET_DECL_IMPLICIT_INSTANTIATION (r); + } + else if (!cp_unevaluated_operand) + register_local_specialization (r, t); + + DECL_CHAIN (r) = NULL_TREE; + + apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), + /*flags=*/0, + args, complain, in_decl); + + /* Preserve a typedef that names a type. */ + if (is_typedef_decl (r)) + { + DECL_ORIGINAL_TYPE (r) = NULL_TREE; + set_underlying_type (r); + } + + layout_decl (r, 0); + } + break; + + default: + gcc_unreachable (); + } +#undef RETURN + + out: + /* Restore the file and line information. */ + input_location = saved_loc; + + return r; +} + +/* Substitute into the ARG_TYPES of a function type. + If END is a TREE_CHAIN, leave it and any following types + un-substituted. */ + +static tree +tsubst_arg_types (tree arg_types, + tree args, + tree end, + tsubst_flags_t complain, + tree in_decl) +{ + tree remaining_arg_types; + tree type = NULL_TREE; + int i = 1; + tree expanded_args = NULL_TREE; + tree default_arg; + + if (!arg_types || arg_types == void_list_node || arg_types == end) + return arg_types; + + remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types), + args, end, complain, in_decl); + if (remaining_arg_types == error_mark_node) + return error_mark_node; + + if (PACK_EXPANSION_P (TREE_VALUE (arg_types))) + { + /* For a pack expansion, perform substitution on the + entire expression. Later on, we'll handle the arguments + one-by-one. */ + expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types), + args, complain, in_decl); + + if (TREE_CODE (expanded_args) == TREE_VEC) + /* So that we'll spin through the parameters, one by one. */ + i = TREE_VEC_LENGTH (expanded_args); + else + { + /* We only partially substituted into the parameter + pack. Our type is TYPE_PACK_EXPANSION. */ + type = expanded_args; + expanded_args = NULL_TREE; + } + } + + while (i > 0) { + --i; + + if (expanded_args) + type = TREE_VEC_ELT (expanded_args, i); + else if (!type) + type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl); + + if (type == error_mark_node) + return error_mark_node; + if (VOID_TYPE_P (type)) + { + if (complain & tf_error) + { + error ("invalid parameter type %qT", type); + if (in_decl) + error ("in declaration %q+D", in_decl); + } + return error_mark_node; + } + /* DR 657. */ + if (abstract_virtuals_error_sfinae (ACU_PARM, type, complain)) + return error_mark_node; + + /* Do array-to-pointer, function-to-pointer conversion, and ignore + top-level qualifiers as required. */ + type = cv_unqualified (type_decays_to (type)); + + /* We do not substitute into default arguments here. The standard + mandates that they be instantiated only when needed, which is + done in build_over_call. */ + default_arg = TREE_PURPOSE (arg_types); + + if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG) + { + /* We've instantiated a template before its default arguments + have been parsed. This can happen for a nested template + class, and is not an error unless we require the default + argument in a call of this function. */ + remaining_arg_types = + tree_cons (default_arg, type, remaining_arg_types); + vec_safe_push (DEFARG_INSTANTIATIONS(default_arg), remaining_arg_types); + } + else + remaining_arg_types = + hash_tree_cons (default_arg, type, remaining_arg_types); + } + + return remaining_arg_types; +} + +/* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does + *not* handle the exception-specification for FNTYPE, because the + initial substitution of explicitly provided template parameters + during argument deduction forbids substitution into the + exception-specification: + + [temp.deduct] + + All references in the function type of the function template to the + corresponding template parameters are replaced by the specified tem- + plate argument values. If a substitution in a template parameter or + in the function type of the function template results in an invalid + type, type deduction fails. [Note: The equivalent substitution in + exception specifications is done only when the function is instanti- + ated, at which point a program is ill-formed if the substitution + results in an invalid type.] */ + +static tree +tsubst_function_type (tree t, + tree args, + tsubst_flags_t complain, + tree in_decl) +{ + tree return_type; + tree arg_types; + tree fntype; + + /* The TYPE_CONTEXT is not used for function/method types. */ + gcc_assert (TYPE_CONTEXT (t) == NULL_TREE); + + /* Substitute the return type. */ + return_type = tsubst (TREE_TYPE (t), args, complain, in_decl); + if (return_type == error_mark_node) + return error_mark_node; + /* DR 486 clarifies that creation of a function type with an + invalid return type is a deduction failure. */ + if (TREE_CODE (return_type) == ARRAY_TYPE + || TREE_CODE (return_type) == FUNCTION_TYPE) + { + if (complain & tf_error) + { + if (TREE_CODE (return_type) == ARRAY_TYPE) + error ("function returning an array"); + else + error ("function returning a function"); + } + return error_mark_node; + } + /* And DR 657. */ + if (abstract_virtuals_error_sfinae (ACU_RETURN, return_type, complain)) + return error_mark_node; + + /* Substitute the argument types. */ + arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, NULL_TREE, + complain, in_decl); + if (arg_types == error_mark_node) + return error_mark_node; + + /* Construct a new type node and return it. */ + if (TREE_CODE (t) == FUNCTION_TYPE) + { + fntype = build_function_type (return_type, arg_types); + fntype = apply_memfn_quals (fntype, + type_memfn_quals (t), + type_memfn_rqual (t)); + } + else + { + tree r = TREE_TYPE (TREE_VALUE (arg_types)); + /* Don't pick up extra function qualifiers from the basetype. */ + r = cp_build_qualified_type_real (r, type_memfn_quals (t), complain); + if (! MAYBE_CLASS_TYPE_P (r)) + { + /* [temp.deduct] + + Type deduction may fail for any of the following + reasons: + + -- Attempting to create "pointer to member of T" when T + is not a class type. */ + if (complain & tf_error) + error ("creating pointer to member function of non-class type %qT", + r); + return error_mark_node; + } + + fntype = build_method_type_directly (r, return_type, + TREE_CHAIN (arg_types)); + fntype = build_ref_qualified_type (fntype, type_memfn_rqual (t)); + } + fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t)); + + return fntype; +} + +/* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template + ARGS into that specification, and return the substituted + specification. If there is no specification, return NULL_TREE. */ + +static tree +tsubst_exception_specification (tree fntype, + tree args, + tsubst_flags_t complain, + tree in_decl, + bool defer_ok) +{ + tree specs; + tree new_specs; + + specs = TYPE_RAISES_EXCEPTIONS (fntype); + new_specs = NULL_TREE; + if (specs && TREE_PURPOSE (specs)) + { + /* A noexcept-specifier. */ + tree expr = TREE_PURPOSE (specs); + if (TREE_CODE (expr) == INTEGER_CST) + new_specs = expr; + else if (defer_ok) + { + /* Defer instantiation of noexcept-specifiers to avoid + excessive instantiations (c++/49107). */ + new_specs = make_node (DEFERRED_NOEXCEPT); + if (DEFERRED_NOEXCEPT_SPEC_P (specs)) + { + /* We already partially instantiated this member template, + so combine the new args with the old. */ + DEFERRED_NOEXCEPT_PATTERN (new_specs) + = DEFERRED_NOEXCEPT_PATTERN (expr); + DEFERRED_NOEXCEPT_ARGS (new_specs) + = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args); + } + else + { + DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr; + DEFERRED_NOEXCEPT_ARGS (new_specs) = args; + } + } + else + new_specs = tsubst_copy_and_build + (expr, args, complain, in_decl, /*function_p=*/false, + /*integral_constant_expression_p=*/true); + new_specs = build_noexcept_spec (new_specs, complain); + } + else if (specs) + { + if (! TREE_VALUE (specs)) + new_specs = specs; + else + while (specs) + { + tree spec; + int i, len = 1; + tree expanded_specs = NULL_TREE; + + if (PACK_EXPANSION_P (TREE_VALUE (specs))) + { + /* Expand the pack expansion type. */ + expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs), + args, complain, + in_decl); + + if (expanded_specs == error_mark_node) + return error_mark_node; + else if (TREE_CODE (expanded_specs) == TREE_VEC) + len = TREE_VEC_LENGTH (expanded_specs); + else + { + /* We're substituting into a member template, so + we got a TYPE_PACK_EXPANSION back. Add that + expansion and move on. */ + gcc_assert (TREE_CODE (expanded_specs) + == TYPE_PACK_EXPANSION); + new_specs = add_exception_specifier (new_specs, + expanded_specs, + complain); + specs = TREE_CHAIN (specs); + continue; + } + } + + for (i = 0; i < len; ++i) + { + if (expanded_specs) + spec = TREE_VEC_ELT (expanded_specs, i); + else + spec = tsubst (TREE_VALUE (specs), args, complain, in_decl); + if (spec == error_mark_node) + return spec; + new_specs = add_exception_specifier (new_specs, spec, + complain); + } + + specs = TREE_CHAIN (specs); + } + } + return new_specs; +} + +/* Take the tree structure T and replace template parameters used + therein with the argument vector ARGS. IN_DECL is an associated + decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE. + Issue error and warning messages under control of COMPLAIN. Note + that we must be relatively non-tolerant of extensions here, in + order to preserve conformance; if we allow substitutions that + should not be allowed, we may allow argument deductions that should + not succeed, and therefore report ambiguous overload situations + where there are none. In theory, we could allow the substitution, + but indicate that it should have failed, and allow our caller to + make sure that the right thing happens, but we don't try to do this + yet. + + This function is used for dealing with types, decls and the like; + for expressions, use tsubst_expr or tsubst_copy. */ + +tree +tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl) +{ + enum tree_code code; + tree type, r = NULL_TREE; + + if (t == NULL_TREE || t == error_mark_node + || t == integer_type_node + || t == void_type_node + || t == char_type_node + || t == unknown_type_node + || TREE_CODE (t) == NAMESPACE_DECL + || TREE_CODE (t) == TRANSLATION_UNIT_DECL) + return t; + + if (DECL_P (t)) + return tsubst_decl (t, args, complain); + + if (args == NULL_TREE) + return t; + + code = TREE_CODE (t); + + if (code == IDENTIFIER_NODE) + type = IDENTIFIER_TYPE_VALUE (t); + else + type = TREE_TYPE (t); + + gcc_assert (type != unknown_type_node); + + /* Reuse typedefs. We need to do this to handle dependent attributes, + such as attribute aligned. */ + if (TYPE_P (t) + && typedef_variant_p (t)) + { + tree decl = TYPE_NAME (t); + + if (alias_template_specialization_p (t)) + { + /* DECL represents an alias template and we want to + instantiate it. */ + tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl)); + tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl); + r = instantiate_alias_template (tmpl, gen_args, complain); + } + else if (DECL_CLASS_SCOPE_P (decl) + && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl)) + && uses_template_parms (DECL_CONTEXT (decl))) + { + tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl)); + tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl); + r = retrieve_specialization (tmpl, gen_args, 0); + } + else if (DECL_FUNCTION_SCOPE_P (decl) + && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl)) + && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl)))) + r = retrieve_local_specialization (decl); + else + /* The typedef is from a non-template context. */ + return t; + + if (r) + { + r = TREE_TYPE (r); + r = cp_build_qualified_type_real + (r, cp_type_quals (t) | cp_type_quals (r), + complain | tf_ignore_bad_quals); + return r; + } + else + { + /* We don't have an instantiation yet, so drop the typedef. */ + int quals = cp_type_quals (t); + t = DECL_ORIGINAL_TYPE (decl); + t = cp_build_qualified_type_real (t, quals, + complain | tf_ignore_bad_quals); + } + } + + if (type + && code != TYPENAME_TYPE + && code != TEMPLATE_TYPE_PARM + && code != IDENTIFIER_NODE + && code != FUNCTION_TYPE + && code != METHOD_TYPE) + type = tsubst (type, args, complain, in_decl); + if (type == error_mark_node) + return error_mark_node; + + switch (code) + { + case RECORD_TYPE: + case UNION_TYPE: + case ENUMERAL_TYPE: + return tsubst_aggr_type (t, args, complain, in_decl, + /*entering_scope=*/0); + + case ERROR_MARK: + case IDENTIFIER_NODE: + case VOID_TYPE: + case REAL_TYPE: + case COMPLEX_TYPE: + case VECTOR_TYPE: + case BOOLEAN_TYPE: + case NULLPTR_TYPE: + case LANG_TYPE: + return t; + + case INTEGER_TYPE: + if (t == integer_type_node) + return t; + + if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST + && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST) + return t; + + { + tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0); + + max = tsubst_expr (omax, args, complain, in_decl, + /*integral_constant_expression_p=*/false); + + /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if + needed. */ + if (TREE_CODE (max) == NOP_EXPR + && TREE_SIDE_EFFECTS (omax) + && !TREE_TYPE (max)) + TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0)); + + /* If we're in a partial instantiation, preserve the magic NOP_EXPR + with TREE_SIDE_EFFECTS that indicates this is not an integral + constant expression. */ + if (processing_template_decl + && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR) + { + gcc_assert (TREE_CODE (max) == NOP_EXPR); + TREE_SIDE_EFFECTS (max) = 1; + } + + return compute_array_index_type (NULL_TREE, max, complain); + } + + case TEMPLATE_TYPE_PARM: + case TEMPLATE_TEMPLATE_PARM: + case BOUND_TEMPLATE_TEMPLATE_PARM: + case TEMPLATE_PARM_INDEX: + { + int idx; + int level; + int levels; + tree arg = NULL_TREE; + + r = NULL_TREE; + + gcc_assert (TREE_VEC_LENGTH (args) > 0); + template_parm_level_and_index (t, &level, &idx); + + levels = TMPL_ARGS_DEPTH (args); + if (level <= levels) + { + arg = TMPL_ARG (args, level, idx); + + if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT) + { + /* See through ARGUMENT_PACK_SELECT arguments. */ + arg = ARGUMENT_PACK_SELECT_ARG (arg); + /* If the selected argument is an expansion E, that most + likely means we were called from + gen_elem_of_pack_expansion_instantiation during the + substituting of pack an argument pack (which Ith + element is a pack expansion, where I is + ARGUMENT_PACK_SELECT_INDEX) into a pack expansion. + In this case, the Ith element resulting from this + substituting is going to be a pack expansion, which + pattern is the pattern of E. Let's return the + pattern of E, and + gen_elem_of_pack_expansion_instantiation will + build the resulting pack expansion from it. */ + if (PACK_EXPANSION_P (arg)) + arg = PACK_EXPANSION_PATTERN (arg); + } + } + + if (arg == error_mark_node) + return error_mark_node; + else if (arg != NULL_TREE) + { + if (ARGUMENT_PACK_P (arg)) + /* If ARG is an argument pack, we don't actually want to + perform a substitution here, because substitutions + for argument packs are only done + element-by-element. We can get to this point when + substituting the type of a non-type template + parameter pack, when that type actually contains + template parameter packs from an outer template, e.g., + + template<typename... Types> struct A { + template<Types... Values> struct B { }; + }; */ + return t; + + if (code == TEMPLATE_TYPE_PARM) + { + int quals; + gcc_assert (TYPE_P (arg)); + + quals = cp_type_quals (arg) | cp_type_quals (t); + + return cp_build_qualified_type_real + (arg, quals, complain | tf_ignore_bad_quals); + } + else if (code == BOUND_TEMPLATE_TEMPLATE_PARM) + { + /* We are processing a type constructed from a + template template parameter. */ + tree argvec = tsubst (TYPE_TI_ARGS (t), + args, complain, in_decl); + if (argvec == error_mark_node) + return error_mark_node; + + gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM + || TREE_CODE (arg) == TEMPLATE_DECL + || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE); + + if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE) + /* Consider this code: + + template <template <class> class Template> + struct Internal { + template <class Arg> using Bind = Template<Arg>; + }; + + template <template <class> class Template, class Arg> + using Instantiate = Template<Arg>; //#0 + + template <template <class> class Template, + class Argument> + using Bind = + Instantiate<Internal<Template>::template Bind, + Argument>; //#1 + + When #1 is parsed, the + BOUND_TEMPLATE_TEMPLATE_PARM representing the + parameter `Template' in #0 matches the + UNBOUND_CLASS_TEMPLATE representing the argument + `Internal<Template>::template Bind'; We then want + to assemble the type `Bind<Argument>' that can't + be fully created right now, because + `Internal<Template>' not being complete, the Bind + template cannot be looked up in that context. So + we need to "store" `Bind<Argument>' for later + when the context of Bind becomes complete. Let's + store that in a TYPENAME_TYPE. */ + return make_typename_type (TYPE_CONTEXT (arg), + build_nt (TEMPLATE_ID_EXPR, + TYPE_IDENTIFIER (arg), + argvec), + typename_type, + complain); + + /* We can get a TEMPLATE_TEMPLATE_PARM here when we + are resolving nested-types in the signature of a + member function templates. Otherwise ARG is a + TEMPLATE_DECL and is the real template to be + instantiated. */ + if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM) + arg = TYPE_NAME (arg); + + r = lookup_template_class (arg, + argvec, in_decl, + DECL_CONTEXT (arg), + /*entering_scope=*/0, + complain); + return cp_build_qualified_type_real + (r, cp_type_quals (t) | cp_type_quals (r), complain); + } + else + /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */ + return convert_from_reference (unshare_expr (arg)); + } + + if (level == 1) + /* This can happen during the attempted tsubst'ing in + unify. This means that we don't yet have any information + about the template parameter in question. */ + return t; + + /* Early in template argument deduction substitution, we don't + want to reduce the level of 'auto', or it will be confused + with a normal template parm in subsequent deduction. */ + if (is_auto (t) && (complain & tf_partial)) + return t; + + /* If we get here, we must have been looking at a parm for a + more deeply nested template. Make a new version of this + template parameter, but with a lower level. */ + switch (code) + { + case TEMPLATE_TYPE_PARM: + case TEMPLATE_TEMPLATE_PARM: + case BOUND_TEMPLATE_TEMPLATE_PARM: + if (cp_type_quals (t)) + { + r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl); + r = cp_build_qualified_type_real + (r, cp_type_quals (t), + complain | (code == TEMPLATE_TYPE_PARM + ? tf_ignore_bad_quals : 0)); + } + else + { + r = copy_type (t); + TEMPLATE_TYPE_PARM_INDEX (r) + = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t), + r, levels, args, complain); + TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r); + TYPE_MAIN_VARIANT (r) = r; + TYPE_POINTER_TO (r) = NULL_TREE; + TYPE_REFERENCE_TO (r) = NULL_TREE; + + if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM) + /* We have reduced the level of the template + template parameter, but not the levels of its + template parameters, so canonical_type_parameter + will not be able to find the canonical template + template parameter for this level. Thus, we + require structural equality checking to compare + TEMPLATE_TEMPLATE_PARMs. */ + SET_TYPE_STRUCTURAL_EQUALITY (r); + else if (TYPE_STRUCTURAL_EQUALITY_P (t)) + SET_TYPE_STRUCTURAL_EQUALITY (r); + else + TYPE_CANONICAL (r) = canonical_type_parameter (r); + + if (code == BOUND_TEMPLATE_TEMPLATE_PARM) + { + tree argvec = tsubst (TYPE_TI_ARGS (t), args, + complain, in_decl); + if (argvec == error_mark_node) + return error_mark_node; + + TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r) + = build_template_info (TYPE_TI_TEMPLATE (t), argvec); + } + } + break; + + case TEMPLATE_PARM_INDEX: + r = reduce_template_parm_level (t, type, levels, args, complain); + break; + + default: + gcc_unreachable (); + } + + return r; + } + + case TREE_LIST: + { + tree purpose, value, chain; + + if (t == void_list_node) + return t; + + purpose = TREE_PURPOSE (t); + if (purpose) + { + purpose = tsubst (purpose, args, complain, in_decl); + if (purpose == error_mark_node) + return error_mark_node; + } + value = TREE_VALUE (t); + if (value) + { + value = tsubst (value, args, complain, in_decl); + if (value == error_mark_node) + return error_mark_node; + } + chain = TREE_CHAIN (t); + if (chain && chain != void_type_node) + { + chain = tsubst (chain, args, complain, in_decl); + if (chain == error_mark_node) + return error_mark_node; + } + if (purpose == TREE_PURPOSE (t) + && value == TREE_VALUE (t) + && chain == TREE_CHAIN (t)) + return t; + return hash_tree_cons (purpose, value, chain); + } + + case TREE_BINFO: + /* We should never be tsubsting a binfo. */ + gcc_unreachable (); + + case TREE_VEC: + /* A vector of template arguments. */ + gcc_assert (!type); + return tsubst_template_args (t, args, complain, in_decl); + + case POINTER_TYPE: + case REFERENCE_TYPE: + { + if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE) + return t; + + /* [temp.deduct] + + Type deduction may fail for any of the following + reasons: + + -- Attempting to create a pointer to reference type. + -- Attempting to create a reference to a reference type or + a reference to void. + + Core issue 106 says that creating a reference to a reference + during instantiation is no longer a cause for failure. We + only enforce this check in strict C++98 mode. */ + if ((TREE_CODE (type) == REFERENCE_TYPE + && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE)) + || (code == REFERENCE_TYPE && VOID_TYPE_P (type))) + { + static location_t last_loc; + + /* We keep track of the last time we issued this error + message to avoid spewing a ton of messages during a + single bad template instantiation. */ + if (complain & tf_error + && last_loc != input_location) + { + if (VOID_TYPE_P (type)) + error ("forming reference to void"); + else if (code == POINTER_TYPE) + error ("forming pointer to reference type %qT", type); + else + error ("forming reference to reference type %qT", type); + last_loc = input_location; + } + + return error_mark_node; + } + else if (TREE_CODE (type) == FUNCTION_TYPE + && (type_memfn_quals (type) != TYPE_UNQUALIFIED + || type_memfn_rqual (type) != REF_QUAL_NONE)) + { + if (complain & tf_error) + { + if (code == POINTER_TYPE) + error ("forming pointer to qualified function type %qT", + type); + else + error ("forming reference to qualified function type %qT", + type); + } + return error_mark_node; + } + else if (code == POINTER_TYPE) + { + r = build_pointer_type (type); + if (TREE_CODE (type) == METHOD_TYPE) + r = build_ptrmemfunc_type (r); + } + else if (TREE_CODE (type) == REFERENCE_TYPE) + /* In C++0x, during template argument substitution, when there is an + attempt to create a reference to a reference type, reference + collapsing is applied as described in [14.3.1/4 temp.arg.type]: + + "If a template-argument for a template-parameter T names a type + that is a reference to a type A, an attempt to create the type + 'lvalue reference to cv T' creates the type 'lvalue reference to + A,' while an attempt to create the type type rvalue reference to + cv T' creates the type T" + */ + r = cp_build_reference_type + (TREE_TYPE (type), + TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type)); + else + r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t)); + r = cp_build_qualified_type_real (r, cp_type_quals (t), complain); + + if (cxx_dialect >= cxx1y + && !(TREE_CODE (t) == REFERENCE_TYPE && REFERENCE_VLA_OK (t)) + && array_of_runtime_bound_p (type) + && (flag_iso || warn_vla > 0)) + { + if (complain & tf_warning_or_error) + pedwarn + (input_location, OPT_Wvla, + code == REFERENCE_TYPE + ? G_("cannot declare reference to array of runtime bound") + : G_("cannot declare pointer to array of runtime bound")); + else + r = error_mark_node; + } + + if (r != error_mark_node) + /* Will this ever be needed for TYPE_..._TO values? */ + layout_type (r); + + return r; + } + case OFFSET_TYPE: + { + r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl); + if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r)) + { + /* [temp.deduct] + + Type deduction may fail for any of the following + reasons: + + -- Attempting to create "pointer to member of T" when T + is not a class type. */ + if (complain & tf_error) + error ("creating pointer to member of non-class type %qT", r); + return error_mark_node; + } + if (TREE_CODE (type) == REFERENCE_TYPE) + { + if (complain & tf_error) + error ("creating pointer to member reference type %qT", type); + return error_mark_node; + } + if (VOID_TYPE_P (type)) + { + if (complain & tf_error) + error ("creating pointer to member of type void"); + return error_mark_node; + } + gcc_assert (TREE_CODE (type) != METHOD_TYPE); + if (TREE_CODE (type) == FUNCTION_TYPE) + { + /* The type of the implicit object parameter gets its + cv-qualifiers from the FUNCTION_TYPE. */ + tree memptr; + tree method_type + = build_memfn_type (type, r, type_memfn_quals (type), + type_memfn_rqual (type)); + memptr = build_ptrmemfunc_type (build_pointer_type (method_type)); + return cp_build_qualified_type_real (memptr, cp_type_quals (t), + complain); + } + else + return cp_build_qualified_type_real (build_ptrmem_type (r, type), + cp_type_quals (t), + complain); + } + case FUNCTION_TYPE: + case METHOD_TYPE: + { + tree fntype; + tree specs; + fntype = tsubst_function_type (t, args, complain, in_decl); + if (fntype == error_mark_node) + return error_mark_node; + + /* Substitute the exception specification. */ + specs = tsubst_exception_specification (t, args, complain, + in_decl, /*defer_ok*/true); + if (specs == error_mark_node) + return error_mark_node; + if (specs) + fntype = build_exception_variant (fntype, specs); + return fntype; + } + case ARRAY_TYPE: + { + tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl); + if (domain == error_mark_node) + return error_mark_node; + + /* As an optimization, we avoid regenerating the array type if + it will obviously be the same as T. */ + if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t)) + return t; + + /* These checks should match the ones in grokdeclarator. + + [temp.deduct] + + The deduction may fail for any of the following reasons: + + -- Attempting to create an array with an element type that + is void, a function type, or a reference type, or [DR337] + an abstract class type. */ + if (VOID_TYPE_P (type) + || TREE_CODE (type) == FUNCTION_TYPE + || TREE_CODE (type) == REFERENCE_TYPE) + { + if (complain & tf_error) + error ("creating array of %qT", type); + return error_mark_node; + } + + if (abstract_virtuals_error_sfinae (ACU_ARRAY, type, complain)) + return error_mark_node; + + r = build_cplus_array_type (type, domain); + + if (TYPE_USER_ALIGN (t)) + { + TYPE_ALIGN (r) = TYPE_ALIGN (t); + TYPE_USER_ALIGN (r) = 1; + } + + return r; + } + + case TYPENAME_TYPE: + { + tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain, + in_decl, /*entering_scope=*/1); + tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args, + complain, in_decl); + + if (ctx == error_mark_node || f == error_mark_node) + return error_mark_node; + + if (!MAYBE_CLASS_TYPE_P (ctx)) + { + if (complain & tf_error) + error ("%qT is not a class, struct, or union type", ctx); + return error_mark_node; + } + else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx)) + { + /* Normally, make_typename_type does not require that the CTX + have complete type in order to allow things like: + + template <class T> struct S { typename S<T>::X Y; }; + + But, such constructs have already been resolved by this + point, so here CTX really should have complete type, unless + it's a partial instantiation. */ + ctx = complete_type (ctx); + if (!COMPLETE_TYPE_P (ctx)) + { + if (complain & tf_error) + cxx_incomplete_type_error (NULL_TREE, ctx); + return error_mark_node; + } + } + + f = make_typename_type (ctx, f, typename_type, + complain | tf_keep_type_decl); + if (f == error_mark_node) + return f; + if (TREE_CODE (f) == TYPE_DECL) + { + complain |= tf_ignore_bad_quals; + f = TREE_TYPE (f); + } + + if (TREE_CODE (f) != TYPENAME_TYPE) + { + if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE) + { + if (complain & tf_error) + error ("%qT resolves to %qT, which is not an enumeration type", + t, f); + else + return error_mark_node; + } + else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f)) + { + if (complain & tf_error) + error ("%qT resolves to %qT, which is is not a class type", + t, f); + else + return error_mark_node; + } + } + + return cp_build_qualified_type_real + (f, cp_type_quals (f) | cp_type_quals (t), complain); + } + + case UNBOUND_CLASS_TEMPLATE: + { + tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain, + in_decl, /*entering_scope=*/1); + tree name = TYPE_IDENTIFIER (t); + tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t)); + + if (ctx == error_mark_node || name == error_mark_node) + return error_mark_node; + + if (parm_list) + parm_list = tsubst_template_parms (parm_list, args, complain); + return make_unbound_class_template (ctx, name, parm_list, complain); + } + + case TYPEOF_TYPE: + { + tree type; + + ++cp_unevaluated_operand; + ++c_inhibit_evaluation_warnings; + + type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args, + complain, in_decl, + /*integral_constant_expression_p=*/false); + + --cp_unevaluated_operand; + --c_inhibit_evaluation_warnings; + + type = finish_typeof (type); + return cp_build_qualified_type_real (type, + cp_type_quals (t) + | cp_type_quals (type), + complain); + } + + case DECLTYPE_TYPE: + { + tree type; + + ++cp_unevaluated_operand; + ++c_inhibit_evaluation_warnings; + + type = tsubst_copy_and_build (DECLTYPE_TYPE_EXPR (t), args, + complain|tf_decltype, in_decl, + /*function_p*/false, + /*integral_constant_expression*/false); + + --cp_unevaluated_operand; + --c_inhibit_evaluation_warnings; + + if (DECLTYPE_FOR_LAMBDA_CAPTURE (t)) + type = lambda_capture_field_type (type, + DECLTYPE_FOR_INIT_CAPTURE (t)); + else if (DECLTYPE_FOR_LAMBDA_PROXY (t)) + type = lambda_proxy_type (type); + else + { + bool id = DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t); + if (id && TREE_CODE (DECLTYPE_TYPE_EXPR (t)) == BIT_NOT_EXPR + && EXPR_P (type)) + /* In a template ~id could be either a complement expression + or an unqualified-id naming a destructor; if instantiating + it produces an expression, it's not an id-expression or + member access. */ + id = false; + type = finish_decltype_type (type, id, complain); + } + return cp_build_qualified_type_real (type, + cp_type_quals (t) + | cp_type_quals (type), + complain); + } + + case UNDERLYING_TYPE: + { + tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args, + complain, in_decl); + return finish_underlying_type (type); + } + + case TYPE_ARGUMENT_PACK: + case NONTYPE_ARGUMENT_PACK: + { + tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code); + tree packed_out = + tsubst_template_args (ARGUMENT_PACK_ARGS (t), + args, + complain, + in_decl); + SET_ARGUMENT_PACK_ARGS (r, packed_out); + + /* For template nontype argument packs, also substitute into + the type. */ + if (code == NONTYPE_ARGUMENT_PACK) + TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl); + + return r; + } + break; + + case INTEGER_CST: + case REAL_CST: + case STRING_CST: + case PLUS_EXPR: + case MINUS_EXPR: + case NEGATE_EXPR: + case NOP_EXPR: + case INDIRECT_REF: + case ADDR_EXPR: + case CALL_EXPR: + case ARRAY_REF: + case SCOPE_REF: + /* We should use one of the expression tsubsts for these codes. */ + gcc_unreachable (); + + default: + sorry ("use of %qs in template", get_tree_code_name (code)); + return error_mark_node; + } +} + +/* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the + type of the expression on the left-hand side of the "." or "->" + operator. */ + +static tree +tsubst_baselink (tree baselink, tree object_type, + tree args, tsubst_flags_t complain, tree in_decl) +{ + tree name; + tree qualifying_scope; + tree fns; + tree optype; + tree template_args = 0; + bool template_id_p = false; + bool qualified = BASELINK_QUALIFIED_P (baselink); + + /* A baselink indicates a function from a base class. Both the + BASELINK_ACCESS_BINFO and the base class referenced may + indicate bases of the template class, rather than the + instantiated class. In addition, lookups that were not + ambiguous before may be ambiguous now. Therefore, we perform + the lookup again. */ + qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink)); + qualifying_scope = tsubst (qualifying_scope, args, + complain, in_decl); + fns = BASELINK_FUNCTIONS (baselink); + optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl); + if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) + { + template_id_p = true; + template_args = TREE_OPERAND (fns, 1); + fns = TREE_OPERAND (fns, 0); + if (template_args) + template_args = tsubst_template_args (template_args, args, + complain, in_decl); + } + name = DECL_NAME (get_first_fn (fns)); + if (IDENTIFIER_TYPENAME_P (name)) + name = mangle_conv_op_name_for_type (optype); + baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1); + if (!baselink) + return error_mark_node; + + /* If lookup found a single function, mark it as used at this + point. (If it lookup found multiple functions the one selected + later by overload resolution will be marked as used at that + point.) */ + if (BASELINK_P (baselink)) + fns = BASELINK_FUNCTIONS (baselink); + if (!template_id_p && !really_overloaded_fn (fns)) + mark_used (OVL_CURRENT (fns)); + + /* Add back the template arguments, if present. */ + if (BASELINK_P (baselink) && template_id_p) + BASELINK_FUNCTIONS (baselink) + = build_nt (TEMPLATE_ID_EXPR, + BASELINK_FUNCTIONS (baselink), + template_args); + /* Update the conversion operator type. */ + BASELINK_OPTYPE (baselink) = optype; + + if (!object_type) + object_type = current_class_type; + + if (qualified) + baselink = adjust_result_of_qualified_name_lookup (baselink, + qualifying_scope, + object_type); + return baselink; +} + +/* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is + true if the qualified-id will be a postfix-expression in-and-of + itself; false if more of the postfix-expression follows the + QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand + of "&". */ + +static tree +tsubst_qualified_id (tree qualified_id, tree args, + tsubst_flags_t complain, tree in_decl, + bool done, bool address_p) +{ + tree expr; + tree scope; + tree name; + bool is_template; + tree template_args; + location_t loc = UNKNOWN_LOCATION; + + gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF); + + /* Figure out what name to look up. */ + name = TREE_OPERAND (qualified_id, 1); + if (TREE_CODE (name) == TEMPLATE_ID_EXPR) + { + is_template = true; + loc = EXPR_LOCATION (name); + template_args = TREE_OPERAND (name, 1); + if (template_args) + template_args = tsubst_template_args (template_args, args, + complain, in_decl); + name = TREE_OPERAND (name, 0); + } + else + { + is_template = false; + template_args = NULL_TREE; + } + + /* Substitute into the qualifying scope. When there are no ARGS, we + are just trying to simplify a non-dependent expression. In that + case the qualifying scope may be dependent, and, in any case, + substituting will not help. */ + scope = TREE_OPERAND (qualified_id, 0); + if (args) + { + scope = tsubst (scope, args, complain, in_decl); + expr = tsubst_copy (name, args, complain, in_decl); + } + else + expr = name; + + if (dependent_scope_p (scope)) + { + if (is_template) + expr = build_min_nt_loc (loc, TEMPLATE_ID_EXPR, expr, template_args); + return build_qualified_name (NULL_TREE, scope, expr, + QUALIFIED_NAME_IS_TEMPLATE (qualified_id)); + } + + if (!BASELINK_P (name) && !DECL_P (expr)) + { + if (TREE_CODE (expr) == BIT_NOT_EXPR) + { + /* A BIT_NOT_EXPR is used to represent a destructor. */ + if (!check_dtor_name (scope, TREE_OPERAND (expr, 0))) + { + error ("qualifying type %qT does not match destructor name ~%qT", + scope, TREE_OPERAND (expr, 0)); + expr = error_mark_node; + } + else + expr = lookup_qualified_name (scope, complete_dtor_identifier, + /*is_type_p=*/0, false); + } + else + expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false); + if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL + ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL) + { + if (complain & tf_error) + { + error ("dependent-name %qE is parsed as a non-type, but " + "instantiation yields a type", qualified_id); + inform (input_location, "say %<typename %E%> if a type is meant", qualified_id); + } + return error_mark_node; + } + } + + if (DECL_P (expr)) + { + check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE, + scope); + /* Remember that there was a reference to this entity. */ + mark_used (expr); + } + + if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST) + { + if (complain & tf_error) + qualified_name_lookup_error (scope, + TREE_OPERAND (qualified_id, 1), + expr, input_location); + return error_mark_node; + } + + if (is_template) + expr = lookup_template_function (expr, template_args); + + if (expr == error_mark_node && complain & tf_error) + qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1), + expr, input_location); + else if (TYPE_P (scope)) + { + expr = (adjust_result_of_qualified_name_lookup + (expr, scope, current_nonlambda_class_type ())); + expr = (finish_qualified_id_expr + (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id), + QUALIFIED_NAME_IS_TEMPLATE (qualified_id), + /*template_arg_p=*/false, complain)); + } + + /* Expressions do not generally have reference type. */ + if (TREE_CODE (expr) != SCOPE_REF + /* However, if we're about to form a pointer-to-member, we just + want the referenced member referenced. */ + && TREE_CODE (expr) != OFFSET_REF) + expr = convert_from_reference (expr); + + return expr; +} + +/* Like tsubst, but deals with expressions. This function just replaces + template parms; to finish processing the resultant expression, use + tsubst_copy_and_build or tsubst_expr. */ + +static tree +tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl) +{ + enum tree_code code; + tree r; + + if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE) + return t; + + code = TREE_CODE (t); + + switch (code) + { + case PARM_DECL: + r = retrieve_local_specialization (t); + + if (r == NULL_TREE) + { + /* We get here for a use of 'this' in an NSDMI. */ + if (DECL_NAME (t) == this_identifier + && at_function_scope_p () + && DECL_CONSTRUCTOR_P (current_function_decl)) + return current_class_ptr; + + /* This can happen for a parameter name used later in a function + declaration (such as in a late-specified return type). Just + make a dummy decl, since it's only used for its type. */ + gcc_assert (cp_unevaluated_operand != 0); + r = tsubst_decl (t, args, complain); + /* Give it the template pattern as its context; its true context + hasn't been instantiated yet and this is good enough for + mangling. */ + DECL_CONTEXT (r) = DECL_CONTEXT (t); + } + + if (TREE_CODE (r) == ARGUMENT_PACK_SELECT) + r = ARGUMENT_PACK_SELECT_ARG (r); + mark_used (r); + return r; + + case CONST_DECL: + { + tree enum_type; + tree v; + + if (DECL_TEMPLATE_PARM_P (t)) + return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl); + /* There is no need to substitute into namespace-scope + enumerators. */ + if (DECL_NAMESPACE_SCOPE_P (t)) + return t; + /* If ARGS is NULL, then T is known to be non-dependent. */ + if (args == NULL_TREE) + return integral_constant_value (t); + + /* Unfortunately, we cannot just call lookup_name here. + Consider: + + template <int I> int f() { + enum E { a = I }; + struct S { void g() { E e = a; } }; + }; + + When we instantiate f<7>::S::g(), say, lookup_name is not + clever enough to find f<7>::a. */ + enum_type + = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl, + /*entering_scope=*/0); + + for (v = TYPE_VALUES (enum_type); + v != NULL_TREE; + v = TREE_CHAIN (v)) + if (TREE_PURPOSE (v) == DECL_NAME (t)) + return TREE_VALUE (v); + + /* We didn't find the name. That should never happen; if + name-lookup found it during preliminary parsing, we + should find it again here during instantiation. */ + gcc_unreachable (); + } + return t; + + case FIELD_DECL: + if (PACK_EXPANSION_P (TREE_TYPE (t))) + { + /* Check for a local specialization set up by + tsubst_pack_expansion. */ + if (tree r = retrieve_local_specialization (t)) + { + if (TREE_CODE (r) == ARGUMENT_PACK_SELECT) + r = ARGUMENT_PACK_SELECT_ARG (r); + return r; + } + + /* When retrieving a capture pack from a generic lambda, remove the + lambda call op's own template argument list from ARGS. Only the + template arguments active for the closure type should be used to + retrieve the pack specialization. */ + if (LAMBDA_FUNCTION_P (current_function_decl) + && (template_class_depth (DECL_CONTEXT (t)) + != TMPL_ARGS_DEPTH (args))) + args = strip_innermost_template_args (args, 1); + + /* Otherwise return the full NONTYPE_ARGUMENT_PACK that + tsubst_decl put in the hash table. */ + return retrieve_specialization (t, args, 0); + } + + if (DECL_CONTEXT (t)) + { + tree ctx; + + ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl, + /*entering_scope=*/1); + if (ctx != DECL_CONTEXT (t)) + { + tree r = lookup_field (ctx, DECL_NAME (t), 0, false); + if (!r) + { + if (complain & tf_error) + error ("using invalid field %qD", t); + return error_mark_node; + } + return r; + } + } + + return t; + + case VAR_DECL: + case FUNCTION_DECL: + if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)) + r = tsubst (t, args, complain, in_decl); + else if (local_variable_p (t)) + { + r = retrieve_local_specialization (t); + if (r == NULL_TREE) + { + if (DECL_ANON_UNION_VAR_P (t)) + { + /* Just use name lookup to find a member alias for an + anonymous union, but then add it to the hash table. */ + r = lookup_name (DECL_NAME (t)); + gcc_assert (DECL_ANON_UNION_VAR_P (r)); + register_local_specialization (r, t); + } + else + { + /* This can happen for a variable used in a late-specified + return type of a local lambda. Just make a dummy decl + since it's only used for its type. */ + if (cp_unevaluated_operand) + return tsubst_decl (t, args, complain); + gcc_assert (errorcount || sorrycount); + return error_mark_node; + } + } + } + else + r = t; + mark_used (r); + return r; + + case NAMESPACE_DECL: + return t; + + case OVERLOAD: + /* An OVERLOAD will always be a non-dependent overload set; an + overload set from function scope will just be represented with an + IDENTIFIER_NODE, and from class scope with a BASELINK. */ + gcc_assert (!uses_template_parms (t)); + return t; + + case BASELINK: + return tsubst_baselink (t, current_nonlambda_class_type (), + args, complain, in_decl); + + case TEMPLATE_DECL: + if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)) + return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)), + args, complain, in_decl); + else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t)) + return tsubst (t, args, complain, in_decl); + else if (DECL_CLASS_SCOPE_P (t) + && uses_template_parms (DECL_CONTEXT (t))) + { + /* Template template argument like the following example need + special treatment: + + template <template <class> class TT> struct C {}; + template <class T> struct D { + template <class U> struct E {}; + C<E> c; // #1 + }; + D<int> d; // #2 + + We are processing the template argument `E' in #1 for + the template instantiation #2. Originally, `E' is a + TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we + have to substitute this with one having context `D<int>'. */ + + tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl); + return lookup_field (context, DECL_NAME(t), 0, false); + } + else + /* Ordinary template template argument. */ + return t; + + case CAST_EXPR: + case REINTERPRET_CAST_EXPR: + case CONST_CAST_EXPR: + case STATIC_CAST_EXPR: + case DYNAMIC_CAST_EXPR: + case IMPLICIT_CONV_EXPR: + case CONVERT_EXPR: + case NOP_EXPR: + return build1 + (code, tsubst (TREE_TYPE (t), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl)); + + case SIZEOF_EXPR: + if (PACK_EXPANSION_P (TREE_OPERAND (t, 0))) + { + + tree expanded, op = TREE_OPERAND (t, 0); + int len = 0; + + if (SIZEOF_EXPR_TYPE_P (t)) + op = TREE_TYPE (op); + + ++cp_unevaluated_operand; + ++c_inhibit_evaluation_warnings; + /* We only want to compute the number of arguments. */ + expanded = tsubst_pack_expansion (op, args, complain, in_decl); + --cp_unevaluated_operand; + --c_inhibit_evaluation_warnings; + + if (TREE_CODE (expanded) == TREE_VEC) + len = TREE_VEC_LENGTH (expanded); + + if (expanded == error_mark_node) + return error_mark_node; + else if (PACK_EXPANSION_P (expanded) + || (TREE_CODE (expanded) == TREE_VEC + && len > 0 + && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1)))) + { + if (TREE_CODE (expanded) == TREE_VEC) + expanded = TREE_VEC_ELT (expanded, len - 1); + + if (TYPE_P (expanded)) + return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR, + complain & tf_error); + else + return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR, + complain & tf_error); + } + else + return build_int_cst (size_type_node, len); + } + if (SIZEOF_EXPR_TYPE_P (t)) + { + r = tsubst (TREE_TYPE (TREE_OPERAND (t, 0)), + args, complain, in_decl); + r = build1 (NOP_EXPR, r, error_mark_node); + r = build1 (SIZEOF_EXPR, + tsubst (TREE_TYPE (t), args, complain, in_decl), r); + SIZEOF_EXPR_TYPE_P (r) = 1; + return r; + } + /* Fall through */ + + case INDIRECT_REF: + case NEGATE_EXPR: + case TRUTH_NOT_EXPR: + case BIT_NOT_EXPR: + case ADDR_EXPR: + case UNARY_PLUS_EXPR: /* Unary + */ + case ALIGNOF_EXPR: + case AT_ENCODE_EXPR: + case ARROW_EXPR: + case THROW_EXPR: + case TYPEID_EXPR: + case REALPART_EXPR: + case IMAGPART_EXPR: + case PAREN_EXPR: + return build1 + (code, tsubst (TREE_TYPE (t), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl)); + + case COMPONENT_REF: + { + tree object; + tree name; + + object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl); + name = TREE_OPERAND (t, 1); + if (TREE_CODE (name) == BIT_NOT_EXPR) + { + name = tsubst_copy (TREE_OPERAND (name, 0), args, + complain, in_decl); + name = build1 (BIT_NOT_EXPR, NULL_TREE, name); + } + else if (TREE_CODE (name) == SCOPE_REF + && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR) + { + tree base = tsubst_copy (TREE_OPERAND (name, 0), args, + complain, in_decl); + name = TREE_OPERAND (name, 1); + name = tsubst_copy (TREE_OPERAND (name, 0), args, + complain, in_decl); + name = build1 (BIT_NOT_EXPR, NULL_TREE, name); + name = build_qualified_name (/*type=*/NULL_TREE, + base, name, + /*template_p=*/false); + } + else if (BASELINK_P (name)) + name = tsubst_baselink (name, + non_reference (TREE_TYPE (object)), + args, complain, + in_decl); + else + name = tsubst_copy (name, args, complain, in_decl); + return build_nt (COMPONENT_REF, object, name, NULL_TREE); + } + + case PLUS_EXPR: + case MINUS_EXPR: + case MULT_EXPR: + case TRUNC_DIV_EXPR: + case CEIL_DIV_EXPR: + case FLOOR_DIV_EXPR: + case ROUND_DIV_EXPR: + case EXACT_DIV_EXPR: + case BIT_AND_EXPR: + case BIT_IOR_EXPR: + case BIT_XOR_EXPR: + case TRUNC_MOD_EXPR: + case FLOOR_MOD_EXPR: + case TRUTH_ANDIF_EXPR: + case TRUTH_ORIF_EXPR: + case TRUTH_AND_EXPR: + case TRUTH_OR_EXPR: + case RSHIFT_EXPR: + case LSHIFT_EXPR: + case RROTATE_EXPR: + case LROTATE_EXPR: + case EQ_EXPR: + case NE_EXPR: + case MAX_EXPR: + case MIN_EXPR: + case LE_EXPR: + case GE_EXPR: + case LT_EXPR: + case GT_EXPR: + case COMPOUND_EXPR: + case DOTSTAR_EXPR: + case MEMBER_REF: + case PREDECREMENT_EXPR: + case PREINCREMENT_EXPR: + case POSTDECREMENT_EXPR: + case POSTINCREMENT_EXPR: + return build_nt + (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl)); + + case SCOPE_REF: + return build_qualified_name (/*type=*/NULL_TREE, + tsubst_copy (TREE_OPERAND (t, 0), + args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 1), + args, complain, in_decl), + QUALIFIED_NAME_IS_TEMPLATE (t)); + + case ARRAY_REF: + return build_nt + (ARRAY_REF, + tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl), + NULL_TREE, NULL_TREE); + + case CALL_EXPR: + { + int n = VL_EXP_OPERAND_LENGTH (t); + tree result = build_vl_exp (CALL_EXPR, n); + int i; + for (i = 0; i < n; i++) + TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args, + complain, in_decl); + return result; + } + + case COND_EXPR: + case MODOP_EXPR: + case PSEUDO_DTOR_EXPR: + case VEC_PERM_EXPR: + { + r = build_nt + (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl)); + TREE_NO_WARNING (r) = TREE_NO_WARNING (t); + return r; + } + + case NEW_EXPR: + { + r = build_nt + (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl)); + NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t); + return r; + } + + case DELETE_EXPR: + { + r = build_nt + (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl)); + DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t); + DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t); + return r; + } + + case TEMPLATE_ID_EXPR: + { + /* Substituted template arguments */ + tree fn = TREE_OPERAND (t, 0); + tree targs = TREE_OPERAND (t, 1); + + fn = tsubst_copy (fn, args, complain, in_decl); + if (targs) + targs = tsubst_template_args (targs, args, complain, in_decl); + + return lookup_template_function (fn, targs); + } + + case TREE_LIST: + { + tree purpose, value, chain; + + if (t == void_list_node) + return t; + + purpose = TREE_PURPOSE (t); + if (purpose) + purpose = tsubst_copy (purpose, args, complain, in_decl); + value = TREE_VALUE (t); + if (value) + value = tsubst_copy (value, args, complain, in_decl); + chain = TREE_CHAIN (t); + if (chain && chain != void_type_node) + chain = tsubst_copy (chain, args, complain, in_decl); + if (purpose == TREE_PURPOSE (t) + && value == TREE_VALUE (t) + && chain == TREE_CHAIN (t)) + return t; + return tree_cons (purpose, value, chain); + } + + case RECORD_TYPE: + case UNION_TYPE: + case ENUMERAL_TYPE: + case INTEGER_TYPE: + case TEMPLATE_TYPE_PARM: + case TEMPLATE_TEMPLATE_PARM: + case BOUND_TEMPLATE_TEMPLATE_PARM: + case TEMPLATE_PARM_INDEX: + case POINTER_TYPE: + case REFERENCE_TYPE: + case OFFSET_TYPE: + case FUNCTION_TYPE: + case METHOD_TYPE: + case ARRAY_TYPE: + case TYPENAME_TYPE: + case UNBOUND_CLASS_TEMPLATE: + case TYPEOF_TYPE: + case DECLTYPE_TYPE: + case TYPE_DECL: + return tsubst (t, args, complain, in_decl); + + case USING_DECL: + t = DECL_NAME (t); + /* Fall through. */ + case IDENTIFIER_NODE: + if (IDENTIFIER_TYPENAME_P (t)) + { + tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl); + return mangle_conv_op_name_for_type (new_type); + } + else + return t; + + case CONSTRUCTOR: + /* This is handled by tsubst_copy_and_build. */ + gcc_unreachable (); + + case VA_ARG_EXPR: + return build_x_va_arg (EXPR_LOCATION (t), + tsubst_copy (TREE_OPERAND (t, 0), args, complain, + in_decl), + tsubst (TREE_TYPE (t), args, complain, in_decl)); + + case CLEANUP_POINT_EXPR: + /* We shouldn't have built any of these during initial template + generation. Instead, they should be built during instantiation + in response to the saved STMT_IS_FULL_EXPR_P setting. */ + gcc_unreachable (); + + case OFFSET_REF: + r = build2 + (code, tsubst (TREE_TYPE (t), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), + tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl)); + PTRMEM_OK_P (r) = PTRMEM_OK_P (t); + mark_used (TREE_OPERAND (r, 1)); + return r; + + case EXPR_PACK_EXPANSION: + error ("invalid use of pack expansion expression"); + return error_mark_node; + + case NONTYPE_ARGUMENT_PACK: + error ("use %<...%> to expand argument pack"); + return error_mark_node; + + case INTEGER_CST: + case REAL_CST: + case STRING_CST: + case COMPLEX_CST: + { + /* Instantiate any typedefs in the type. */ + tree type = tsubst (TREE_TYPE (t), args, complain, in_decl); + r = fold_convert (type, t); + gcc_assert (TREE_CODE (r) == code); + return r; + } + + case PTRMEM_CST: + /* These can sometimes show up in a partial instantiation, but never + involve template parms. */ + gcc_assert (!uses_template_parms (t)); + return t; + + default: + /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */ + gcc_checking_assert (false); + return t; + } +} + +/* Like tsubst_copy, but specifically for OpenMP clauses. */ + +static tree +tsubst_omp_clauses (tree clauses, bool declare_simd, + tree args, tsubst_flags_t complain, tree in_decl) +{ + tree new_clauses = NULL, nc, oc; + + for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc)) + { + nc = copy_node (oc); + OMP_CLAUSE_CHAIN (nc) = new_clauses; + new_clauses = nc; + + switch (OMP_CLAUSE_CODE (nc)) + { + case OMP_CLAUSE_LASTPRIVATE: + if (OMP_CLAUSE_LASTPRIVATE_STMT (oc)) + { + OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list (); + tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain, + in_decl, /*integral_constant_expression_p=*/false); + OMP_CLAUSE_LASTPRIVATE_STMT (nc) + = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc)); + } + /* FALLTHRU */ + case OMP_CLAUSE_PRIVATE: + case OMP_CLAUSE_SHARED: + case OMP_CLAUSE_FIRSTPRIVATE: + case OMP_CLAUSE_COPYIN: + case OMP_CLAUSE_COPYPRIVATE: + case OMP_CLAUSE_IF: + case OMP_CLAUSE_NUM_THREADS: + case OMP_CLAUSE_SCHEDULE: + case OMP_CLAUSE_COLLAPSE: + case OMP_CLAUSE_FINAL: + case OMP_CLAUSE_DEPEND: + case OMP_CLAUSE_FROM: + case OMP_CLAUSE_TO: + case OMP_CLAUSE_UNIFORM: + case OMP_CLAUSE_MAP: + case OMP_CLAUSE_DEVICE: + case OMP_CLAUSE_DIST_SCHEDULE: + case OMP_CLAUSE_NUM_TEAMS: + case OMP_CLAUSE_THREAD_LIMIT: + case OMP_CLAUSE_SAFELEN: + case OMP_CLAUSE_SIMDLEN: + OMP_CLAUSE_OPERAND (nc, 0) + = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain, + in_decl, /*integral_constant_expression_p=*/false); + break; + case OMP_CLAUSE_REDUCTION: + if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (oc)) + { + tree placeholder = OMP_CLAUSE_REDUCTION_PLACEHOLDER (oc); + if (TREE_CODE (placeholder) == SCOPE_REF) + { + tree scope = tsubst (TREE_OPERAND (placeholder, 0), args, + complain, in_decl); + OMP_CLAUSE_REDUCTION_PLACEHOLDER (nc) + = build_qualified_name (NULL_TREE, scope, + TREE_OPERAND (placeholder, 1), + false); + } + else + gcc_assert (identifier_p (placeholder)); + } + OMP_CLAUSE_OPERAND (nc, 0) + = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain, + in_decl, /*integral_constant_expression_p=*/false); + break; + case OMP_CLAUSE_LINEAR: + case OMP_CLAUSE_ALIGNED: + OMP_CLAUSE_OPERAND (nc, 0) + = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain, + in_decl, /*integral_constant_expression_p=*/false); + OMP_CLAUSE_OPERAND (nc, 1) + = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 1), args, complain, + in_decl, /*integral_constant_expression_p=*/false); + break; + + case OMP_CLAUSE_NOWAIT: + case OMP_CLAUSE_ORDERED: + case OMP_CLAUSE_DEFAULT: + case OMP_CLAUSE_UNTIED: + case OMP_CLAUSE_MERGEABLE: + case OMP_CLAUSE_INBRANCH: + case OMP_CLAUSE_NOTINBRANCH: + case OMP_CLAUSE_PROC_BIND: + case OMP_CLAUSE_FOR: + case OMP_CLAUSE_PARALLEL: + case OMP_CLAUSE_SECTIONS: + case OMP_CLAUSE_TASKGROUP: + break; + default: + gcc_unreachable (); + } + } + + new_clauses = nreverse (new_clauses); + if (!declare_simd) + new_clauses = finish_omp_clauses (new_clauses); + return new_clauses; +} + +/* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */ + +static tree +tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain, + tree in_decl) +{ +#define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl) + + tree purpose, value, chain; + + if (t == NULL) + return t; + + if (TREE_CODE (t) != TREE_LIST) + return tsubst_copy_and_build (t, args, complain, in_decl, + /*function_p=*/false, + /*integral_constant_expression_p=*/false); + + if (t == void_list_node) + return t; + + purpose = TREE_PURPOSE (t); + if (purpose) + purpose = RECUR (purpose); + value = TREE_VALUE (t); + if (value) + { + if (TREE_CODE (value) != LABEL_DECL) + value = RECUR (value); + else + { + value = lookup_label (DECL_NAME (value)); + gcc_assert (TREE_CODE (value) == LABEL_DECL); + TREE_USED (value) = 1; + } + } + chain = TREE_CHAIN (t); + if (chain && chain != void_type_node) + chain = RECUR (chain); + return tree_cons (purpose, value, chain); +#undef RECUR +} + +/* Substitute one OMP_FOR iterator. */ + +static void +tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv, + tree condv, tree incrv, tree *clauses, + tree args, tsubst_flags_t complain, tree in_decl, + bool integral_constant_expression_p) +{ +#define RECUR(NODE) \ + tsubst_expr ((NODE), args, complain, in_decl, \ + integral_constant_expression_p) + tree decl, init, cond, incr; + + init = TREE_VEC_ELT (OMP_FOR_INIT (t), i); + gcc_assert (TREE_CODE (init) == MODIFY_EXPR); + decl = TREE_OPERAND (init, 0); + init = TREE_OPERAND (init, 1); + tree decl_expr = NULL_TREE; + if (init && TREE_CODE (init) == DECL_EXPR) + { + /* We need to jump through some hoops to handle declarations in the + for-init-statement, since we might need to handle auto deduction, + but we need to keep control of initialization. */ + decl_expr = init; + init = DECL_INITIAL (DECL_EXPR_DECL (init)); + decl = tsubst_decl (decl, args, complain); + } + else + decl = RECUR (decl); + init = RECUR (init); + + tree auto_node = type_uses_auto (TREE_TYPE (decl)); + if (auto_node && init) + TREE_TYPE (decl) + = do_auto_deduction (TREE_TYPE (decl), init, auto_node); + + gcc_assert (!type_dependent_expression_p (decl)); + + if (!CLASS_TYPE_P (TREE_TYPE (decl))) + { + if (decl_expr) + { + /* Declare the variable, but don't let that initialize it. */ + tree init_sav = DECL_INITIAL (DECL_EXPR_DECL (decl_expr)); + DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL_TREE; + RECUR (decl_expr); + DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init_sav; + } + + cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i)); + incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i); + if (TREE_CODE (incr) == MODIFY_EXPR) + incr = build_x_modify_expr (EXPR_LOCATION (incr), + RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR, + RECUR (TREE_OPERAND (incr, 1)), + complain); + else + incr = RECUR (incr); + TREE_VEC_ELT (declv, i) = decl; + TREE_VEC_ELT (initv, i) = init; + TREE_VEC_ELT (condv, i) = cond; + TREE_VEC_ELT (incrv, i) = incr; + return; + } + + if (decl_expr) + { + /* Declare and initialize the variable. */ + RECUR (decl_expr); + init = NULL_TREE; + } + else if (init) + { + tree c; + for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c)) + { + if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE + || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE) + && OMP_CLAUSE_DECL (c) == decl) + break; + else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE + && OMP_CLAUSE_DECL (c) == decl) + error ("iteration variable %qD should not be firstprivate", decl); + else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION + && OMP_CLAUSE_DECL (c) == decl) + error ("iteration variable %qD should not be reduction", decl); + } + if (c == NULL) + { + c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE); + OMP_CLAUSE_DECL (c) = decl; + c = finish_omp_clauses (c); + if (c) + { + OMP_CLAUSE_CHAIN (c) = *clauses; + *clauses = c; + } + } + } + cond = TREE_VEC_ELT (OMP_FOR_COND (t), i); + if (COMPARISON_CLASS_P (cond)) + cond = build2 (TREE_CODE (cond), boolean_type_node, + RECUR (TREE_OPERAND (cond, 0)), + RECUR (TREE_OPERAND (cond, 1))); + else + cond = RECUR (cond); + incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i); + switch (TREE_CODE (incr)) + { + case PREINCREMENT_EXPR: + case PREDECREMENT_EXPR: + case POSTINCREMENT_EXPR: + case POSTDECREMENT_EXPR: + incr = build2 (TREE_CODE (incr), TREE_TYPE (decl), + RECUR (TREE_OPERAND (incr, 0)), NULL_TREE); + break; + case MODIFY_EXPR: + if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR + || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR) + { + tree rhs = TREE_OPERAND (incr, 1); + incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), + RECUR (TREE_OPERAND (incr, 0)), + build2 (TREE_CODE (rhs), TREE_TYPE (decl), + RECUR (TREE_OPERAND (rhs, 0)), + RECUR (TREE_OPERAND (rhs, 1)))); + } + else + incr = RECUR (incr); + break; + case MODOP_EXPR: + if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR + || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR) + { + tree lhs = RECUR (TREE_OPERAND (incr, 0)); + incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs, + build2 (TREE_CODE (TREE_OPERAND (incr, 1)), + TREE_TYPE (decl), lhs, + RECUR (TREE_OPERAND (incr, 2)))); + } + else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR + && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR + || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR))) + { + tree rhs = TREE_OPERAND (incr, 2); + incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), + RECUR (TREE_OPERAND (incr, 0)), + build2 (TREE_CODE (rhs), TREE_TYPE (decl), + RECUR (TREE_OPERAND (rhs, 0)), + RECUR (TREE_OPERAND (rhs, 1)))); + } + else + incr = RECUR (incr); + break; + default: + incr = RECUR (incr); + break; + } + + TREE_VEC_ELT (declv, i) = decl; + TREE_VEC_ELT (initv, i) = init; + TREE_VEC_ELT (condv, i) = cond; + TREE_VEC_ELT (incrv, i) = incr; +#undef RECUR +} + +/* Like tsubst_copy for expressions, etc. but also does semantic + processing. */ + +static tree +tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl, + bool integral_constant_expression_p) +{ +#define RETURN(EXP) do { r = (EXP); goto out; } while(0) +#define RECUR(NODE) \ + tsubst_expr ((NODE), args, complain, in_decl, \ + integral_constant_expression_p) + + tree stmt, tmp; + tree r; + location_t loc; + + if (t == NULL_TREE || t == error_mark_node) + return t; + + loc = input_location; + if (EXPR_HAS_LOCATION (t)) + input_location = EXPR_LOCATION (t); + if (STATEMENT_CODE_P (TREE_CODE (t))) + current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t); + + switch (TREE_CODE (t)) + { + case STATEMENT_LIST: + { + tree_stmt_iterator i; + for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) + RECUR (tsi_stmt (i)); + break; + } + + case CTOR_INITIALIZER: + finish_mem_initializers (tsubst_initializer_list + (TREE_OPERAND (t, 0), args)); + break; + + case RETURN_EXPR: + finish_return_stmt (RECUR (TREE_OPERAND (t, 0))); + break; + + case EXPR_STMT: + tmp = RECUR (EXPR_STMT_EXPR (t)); + if (EXPR_STMT_STMT_EXPR_RESULT (t)) + finish_stmt_expr_expr (tmp, cur_stmt_expr); + else + finish_expr_stmt (tmp); + break; + + case USING_STMT: + do_using_directive (USING_STMT_NAMESPACE (t)); + break; + + case DECL_EXPR: + { + tree decl, pattern_decl; + tree init; + + pattern_decl = decl = DECL_EXPR_DECL (t); + if (TREE_CODE (decl) == LABEL_DECL) + finish_label_decl (DECL_NAME (decl)); + else if (TREE_CODE (decl) == USING_DECL) + { + tree scope = USING_DECL_SCOPE (decl); + tree name = DECL_NAME (decl); + tree decl; + + scope = tsubst (scope, args, complain, in_decl); + decl = lookup_qualified_name (scope, name, + /*is_type_p=*/false, + /*complain=*/false); + if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST) + qualified_name_lookup_error (scope, name, decl, input_location); + else + do_local_using_decl (decl, scope, name); + } + else if (DECL_PACK_P (decl)) + { + /* Don't build up decls for a variadic capture proxy, we'll + instantiate the elements directly as needed. */ + break; + } + else + { + init = DECL_INITIAL (decl); + decl = tsubst (decl, args, complain, in_decl); + if (decl != error_mark_node) + { + /* By marking the declaration as instantiated, we avoid + trying to instantiate it. Since instantiate_decl can't + handle local variables, and since we've already done + all that needs to be done, that's the right thing to + do. */ + if (VAR_P (decl)) + DECL_TEMPLATE_INSTANTIATED (decl) = 1; + if (VAR_P (decl) + && ANON_AGGR_TYPE_P (TREE_TYPE (decl))) + /* Anonymous aggregates are a special case. */ + finish_anon_union (decl); + else if (is_capture_proxy (DECL_EXPR_DECL (t))) + { + DECL_CONTEXT (decl) = current_function_decl; + if (DECL_NAME (decl) == this_identifier) + { + tree lam = DECL_CONTEXT (current_function_decl); + lam = CLASSTYPE_LAMBDA_EXPR (lam); + LAMBDA_EXPR_THIS_CAPTURE (lam) = decl; + } + insert_capture_proxy (decl); + } + else if (DECL_IMPLICIT_TYPEDEF_P (t)) + /* We already did a pushtag. */; + else if (TREE_CODE (decl) == FUNCTION_DECL + && DECL_OMP_DECLARE_REDUCTION_P (decl) + && DECL_FUNCTION_SCOPE_P (pattern_decl)) + { + DECL_CONTEXT (decl) = NULL_TREE; + pushdecl (decl); + DECL_CONTEXT (decl) = current_function_decl; + cp_check_omp_declare_reduction (decl); + } + else + { + int const_init = false; + maybe_push_decl (decl); + if (VAR_P (decl) + && DECL_PRETTY_FUNCTION_P (decl)) + { + /* For __PRETTY_FUNCTION__ we have to adjust the + initializer. */ + const char *const name + = cxx_printable_name (current_function_decl, 2); + init = cp_fname_init (name, &TREE_TYPE (decl)); + } + else + { + tree t = RECUR (init); + + if (init && !t) + { + /* If we had an initializer but it + instantiated to nothing, + value-initialize the object. This will + only occur when the initializer was a + pack expansion where the parameter packs + used in that expansion were of length + zero. */ + init = build_value_init (TREE_TYPE (decl), + complain); + if (TREE_CODE (init) == AGGR_INIT_EXPR) + init = get_target_expr_sfinae (init, complain); + } + else + init = t; + } + + if (VAR_P (decl)) + const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P + (pattern_decl)); + cp_finish_decl (decl, init, const_init, NULL_TREE, 0); + } + } + } + + break; + } + + case FOR_STMT: + stmt = begin_for_stmt (NULL_TREE, NULL_TREE); + RECUR (FOR_INIT_STMT (t)); + finish_for_init_stmt (stmt); + tmp = RECUR (FOR_COND (t)); + finish_for_cond (tmp, stmt, false); + tmp = RECUR (FOR_EXPR (t)); + finish_for_expr (tmp, stmt); + RECUR (FOR_BODY (t)); + finish_for_stmt (stmt); + break; + + case RANGE_FOR_STMT: + { + tree decl, expr; + stmt = begin_for_stmt (NULL_TREE, NULL_TREE); + decl = RANGE_FOR_DECL (t); + decl = tsubst (decl, args, complain, in_decl); + maybe_push_decl (decl); + expr = RECUR (RANGE_FOR_EXPR (t)); + stmt = cp_convert_range_for (stmt, decl, expr, RANGE_FOR_IVDEP (t)); + RECUR (RANGE_FOR_BODY (t)); + finish_for_stmt (stmt); + } + break; + + case WHILE_STMT: + stmt = begin_while_stmt (); + tmp = RECUR (WHILE_COND (t)); + finish_while_stmt_cond (tmp, stmt, false); + RECUR (WHILE_BODY (t)); + finish_while_stmt (stmt); + break; + + case DO_STMT: + stmt = begin_do_stmt (); + RECUR (DO_BODY (t)); + finish_do_body (stmt); + tmp = RECUR (DO_COND (t)); + finish_do_stmt (tmp, stmt, false); + break; + + case IF_STMT: + stmt = begin_if_stmt (); + tmp = RECUR (IF_COND (t)); + finish_if_stmt_cond (tmp, stmt); + RECUR (THEN_CLAUSE (t)); + finish_then_clause (stmt); + + if (ELSE_CLAUSE (t)) + { + begin_else_clause (stmt); + RECUR (ELSE_CLAUSE (t)); + finish_else_clause (stmt); + } + + finish_if_stmt (stmt); + break; + + case BIND_EXPR: + if (BIND_EXPR_BODY_BLOCK (t)) + stmt = begin_function_body (); + else + stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t) + ? BCS_TRY_BLOCK : 0); + + RECUR (BIND_EXPR_BODY (t)); + + if (BIND_EXPR_BODY_BLOCK (t)) + finish_function_body (stmt); + else + finish_compound_stmt (stmt); + break; + + case BREAK_STMT: + finish_break_stmt (); + break; + + case CONTINUE_STMT: + finish_continue_stmt (); + break; + + case SWITCH_STMT: + stmt = begin_switch_stmt (); + tmp = RECUR (SWITCH_STMT_COND (t)); + finish_switch_cond (tmp, stmt); + RECUR (SWITCH_STMT_BODY (t)); + finish_switch_stmt (stmt); + break; + + case CASE_LABEL_EXPR: + finish_case_label (EXPR_LOCATION (t), + RECUR (CASE_LOW (t)), + RECUR (CASE_HIGH (t))); + break; + + case LABEL_EXPR: + { + tree decl = LABEL_EXPR_LABEL (t); + tree label; + + label = finish_label_stmt (DECL_NAME (decl)); + if (DECL_ATTRIBUTES (decl) != NULL_TREE) + cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0); + } + break; + + case GOTO_EXPR: + tmp = GOTO_DESTINATION (t); + if (TREE_CODE (tmp) != LABEL_DECL) + /* Computed goto's must be tsubst'd into. On the other hand, + non-computed gotos must not be; the identifier in question + will have no binding. */ + tmp = RECUR (tmp); + else + tmp = DECL_NAME (tmp); + finish_goto_stmt (tmp); + break; + + case ASM_EXPR: + tmp = finish_asm_stmt + (ASM_VOLATILE_P (t), + RECUR (ASM_STRING (t)), + tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl), + tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl), + tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl), + tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl)); + { + tree asm_expr = tmp; + if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR) + asm_expr = TREE_OPERAND (asm_expr, 0); + ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t); + } + break; + + case TRY_BLOCK: + if (CLEANUP_P (t)) + { + stmt = begin_try_block (); + RECUR (TRY_STMTS (t)); + finish_cleanup_try_block (stmt); + finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt); + } + else + { + tree compound_stmt = NULL_TREE; + + if (FN_TRY_BLOCK_P (t)) + stmt = begin_function_try_block (&compound_stmt); + else + stmt = begin_try_block (); + + RECUR (TRY_STMTS (t)); + + if (FN_TRY_BLOCK_P (t)) + finish_function_try_block (stmt); + else + finish_try_block (stmt); + + RECUR (TRY_HANDLERS (t)); + if (FN_TRY_BLOCK_P (t)) + finish_function_handler_sequence (stmt, compound_stmt); + else + finish_handler_sequence (stmt); + } + break; + + case HANDLER: + { + tree decl = HANDLER_PARMS (t); + + if (decl) + { + decl = tsubst (decl, args, complain, in_decl); + /* Prevent instantiate_decl from trying to instantiate + this variable. We've already done all that needs to be + done. */ + if (decl != error_mark_node) + DECL_TEMPLATE_INSTANTIATED (decl) = 1; + } + stmt = begin_handler (); + finish_handler_parms (decl, stmt); + RECUR (HANDLER_BODY (t)); + finish_handler (stmt); + } + break; + + case TAG_DEFN: + tmp = tsubst (TREE_TYPE (t), args, complain, NULL_TREE); + if (CLASS_TYPE_P (tmp)) + { + /* Local classes are not independent templates; they are + instantiated along with their containing function. And this + way we don't have to deal with pushing out of one local class + to instantiate a member of another local class. */ + tree fn; + /* Closures are handled by the LAMBDA_EXPR. */ + gcc_assert (!LAMBDA_TYPE_P (TREE_TYPE (t))); + complete_type (tmp); + for (fn = TYPE_METHODS (tmp); fn; fn = DECL_CHAIN (fn)) + if (!DECL_ARTIFICIAL (fn)) + instantiate_decl (fn, /*defer_ok*/0, /*expl_inst_class*/false); + } + break; + + case STATIC_ASSERT: + { + tree condition; + + ++c_inhibit_evaluation_warnings; + condition = + tsubst_expr (STATIC_ASSERT_CONDITION (t), + args, + complain, in_decl, + /*integral_constant_expression_p=*/true); + --c_inhibit_evaluation_warnings; + + finish_static_assert (condition, + STATIC_ASSERT_MESSAGE (t), + STATIC_ASSERT_SOURCE_LOCATION (t), + /*member_p=*/false); + } + break; + + case OMP_PARALLEL: + tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t), false, + args, complain, in_decl); + stmt = begin_omp_parallel (); + RECUR (OMP_PARALLEL_BODY (t)); + OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt)) + = OMP_PARALLEL_COMBINED (t); + break; + + case OMP_TASK: + tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t), false, + args, complain, in_decl); + stmt = begin_omp_task (); + RECUR (OMP_TASK_BODY (t)); + finish_omp_task (tmp, stmt); + break; + + case OMP_FOR: + case OMP_SIMD: + case CILK_SIMD: + case OMP_DISTRIBUTE: + { + tree clauses, body, pre_body; + tree declv = NULL_TREE, initv = NULL_TREE, condv = NULL_TREE; + tree incrv = NULL_TREE; + int i; + + clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t), false, + args, complain, in_decl); + if (OMP_FOR_INIT (t) != NULL_TREE) + { + declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t))); + initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t))); + condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t))); + incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t))); + } + + stmt = begin_omp_structured_block (); + + pre_body = push_stmt_list (); + RECUR (OMP_FOR_PRE_BODY (t)); + pre_body = pop_stmt_list (pre_body); + + if (OMP_FOR_INIT (t) != NULL_TREE) + for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++) + tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv, + &clauses, args, complain, in_decl, + integral_constant_expression_p); + + body = push_stmt_list (); + RECUR (OMP_FOR_BODY (t)); + body = pop_stmt_list (body); + + if (OMP_FOR_INIT (t) != NULL_TREE) + t = finish_omp_for (EXPR_LOCATION (t), TREE_CODE (t), declv, initv, + condv, incrv, body, pre_body, clauses); + else + { + t = make_node (TREE_CODE (t)); + TREE_TYPE (t) = void_type_node; + OMP_FOR_BODY (t) = body; + OMP_FOR_PRE_BODY (t) = pre_body; + OMP_FOR_CLAUSES (t) = clauses; + SET_EXPR_LOCATION (t, EXPR_LOCATION (t)); + add_stmt (t); + } + + add_stmt (finish_omp_structured_block (stmt)); + } + break; + + case OMP_SECTIONS: + case OMP_SINGLE: + case OMP_TEAMS: + case OMP_TARGET_DATA: + case OMP_TARGET: + tmp = tsubst_omp_clauses (OMP_CLAUSES (t), false, + args, complain, in_decl); + stmt = push_stmt_list (); + RECUR (OMP_BODY (t)); + stmt = pop_stmt_list (stmt); + + t = copy_node (t); + OMP_BODY (t) = stmt; + OMP_CLAUSES (t) = tmp; + add_stmt (t); + break; + + case OMP_TARGET_UPDATE: + tmp = tsubst_omp_clauses (OMP_TARGET_UPDATE_CLAUSES (t), false, + args, complain, in_decl); + t = copy_node (t); + OMP_CLAUSES (t) = tmp; + add_stmt (t); + break; + + case OMP_SECTION: + case OMP_CRITICAL: + case OMP_MASTER: + case OMP_TASKGROUP: + case OMP_ORDERED: + stmt = push_stmt_list (); + RECUR (OMP_BODY (t)); + stmt = pop_stmt_list (stmt); + + t = copy_node (t); + OMP_BODY (t) = stmt; + add_stmt (t); + break; + + case OMP_ATOMIC: + gcc_assert (OMP_ATOMIC_DEPENDENT_P (t)); + if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR) + { + tree op1 = TREE_OPERAND (t, 1); + tree rhs1 = NULL_TREE; + tree lhs, rhs; + if (TREE_CODE (op1) == COMPOUND_EXPR) + { + rhs1 = RECUR (TREE_OPERAND (op1, 0)); + op1 = TREE_OPERAND (op1, 1); + } + lhs = RECUR (TREE_OPERAND (op1, 0)); + rhs = RECUR (TREE_OPERAND (op1, 1)); + finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs, + NULL_TREE, NULL_TREE, rhs1, + OMP_ATOMIC_SEQ_CST (t)); + } + else + { + tree op1 = TREE_OPERAND (t, 1); + tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE; + tree rhs1 = NULL_TREE; + enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1)); + enum tree_code opcode = NOP_EXPR; + if (code == OMP_ATOMIC_READ) + { + v = RECUR (TREE_OPERAND (op1, 0)); + lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0)); + } + else if (code == OMP_ATOMIC_CAPTURE_OLD + || code == OMP_ATOMIC_CAPTURE_NEW) + { + tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1); + v = RECUR (TREE_OPERAND (op1, 0)); + lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0)); + if (TREE_CODE (op11) == COMPOUND_EXPR) + { + rhs1 = RECUR (TREE_OPERAND (op11, 0)); + op11 = TREE_OPERAND (op11, 1); + } + lhs = RECUR (TREE_OPERAND (op11, 0)); + rhs = RECUR (TREE_OPERAND (op11, 1)); + opcode = TREE_CODE (op11); + if (opcode == MODIFY_EXPR) + opcode = NOP_EXPR; + } + else + { + code = OMP_ATOMIC; + lhs = RECUR (TREE_OPERAND (op1, 0)); + rhs = RECUR (TREE_OPERAND (op1, 1)); + } + finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1, + OMP_ATOMIC_SEQ_CST (t)); + } + break; + + case TRANSACTION_EXPR: + { + int flags = 0; + flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0); + flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0); + + if (TRANSACTION_EXPR_IS_STMT (t)) + { + tree body = TRANSACTION_EXPR_BODY (t); + tree noex = NULL_TREE; + if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) + { + noex = MUST_NOT_THROW_COND (body); + if (noex == NULL_TREE) + noex = boolean_true_node; + body = TREE_OPERAND (body, 0); + } + stmt = begin_transaction_stmt (input_location, NULL, flags); + RECUR (body); + finish_transaction_stmt (stmt, NULL, flags, RECUR (noex)); + } + else + { + stmt = build_transaction_expr (EXPR_LOCATION (t), + RECUR (TRANSACTION_EXPR_BODY (t)), + flags, NULL_TREE); + RETURN (stmt); + } + } + break; + + case MUST_NOT_THROW_EXPR: + RETURN (build_must_not_throw_expr (RECUR (TREE_OPERAND (t, 0)), + RECUR (MUST_NOT_THROW_COND (t)))); + + case EXPR_PACK_EXPANSION: + error ("invalid use of pack expansion expression"); + RETURN (error_mark_node); + + case NONTYPE_ARGUMENT_PACK: + error ("use %<...%> to expand argument pack"); + RETURN (error_mark_node); + + case CILK_SPAWN_STMT: + cfun->calls_cilk_spawn = 1; + RETURN (build_cilk_spawn (EXPR_LOCATION (t), RECUR (CILK_SPAWN_FN (t)))); + + case CILK_SYNC_STMT: + RETURN (build_cilk_sync ()); + + case COMPOUND_EXPR: + tmp = RECUR (TREE_OPERAND (t, 0)); + if (tmp == NULL_TREE) + /* If the first operand was a statement, we're done with it. */ + RETURN (RECUR (TREE_OPERAND (t, 1))); + RETURN (build_x_compound_expr (EXPR_LOCATION (t), tmp, + RECUR (TREE_OPERAND (t, 1)), + complain)); + + case ANNOTATE_EXPR: + tmp = RECUR (TREE_OPERAND (t, 0)); + RETURN (build2_loc (EXPR_LOCATION (t), ANNOTATE_EXPR, + TREE_TYPE (tmp), tmp, RECUR (TREE_OPERAND (t, 1)))); + + default: + gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t))); + + RETURN (tsubst_copy_and_build (t, args, complain, in_decl, + /*function_p=*/false, + integral_constant_expression_p)); + } + + RETURN (NULL_TREE); + out: + input_location = loc; + return r; +#undef RECUR +#undef RETURN +} + +/* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION + function. For description of the body see comment above + cp_parser_omp_declare_reduction_exprs. */ + +static void +tsubst_omp_udr (tree t, tree args, tsubst_flags_t complain, tree in_decl) +{ + if (t == NULL_TREE || t == error_mark_node) + return; + + gcc_assert (TREE_CODE (t) == STATEMENT_LIST); + + tree_stmt_iterator tsi; + int i; + tree stmts[7]; + memset (stmts, 0, sizeof stmts); + for (i = 0, tsi = tsi_start (t); + i < 7 && !tsi_end_p (tsi); + i++, tsi_next (&tsi)) + stmts[i] = tsi_stmt (tsi); + gcc_assert (tsi_end_p (tsi)); + + if (i >= 3) + { + gcc_assert (TREE_CODE (stmts[0]) == DECL_EXPR + && TREE_CODE (stmts[1]) == DECL_EXPR); + tree omp_out = tsubst (DECL_EXPR_DECL (stmts[0]), + args, complain, in_decl); + tree omp_in = tsubst (DECL_EXPR_DECL (stmts[1]), + args, complain, in_decl); + DECL_CONTEXT (omp_out) = current_function_decl; + DECL_CONTEXT (omp_in) = current_function_decl; + keep_next_level (true); + tree block = begin_omp_structured_block (); + tsubst_expr (stmts[2], args, complain, in_decl, false); + block = finish_omp_structured_block (block); + block = maybe_cleanup_point_expr_void (block); + add_decl_expr (omp_out); + if (TREE_NO_WARNING (DECL_EXPR_DECL (stmts[0]))) + TREE_NO_WARNING (omp_out) = 1; + add_decl_expr (omp_in); + finish_expr_stmt (block); + } + if (i >= 6) + { + gcc_assert (TREE_CODE (stmts[3]) == DECL_EXPR + && TREE_CODE (stmts[4]) == DECL_EXPR); + tree omp_priv = tsubst (DECL_EXPR_DECL (stmts[3]), + args, complain, in_decl); + tree omp_orig = tsubst (DECL_EXPR_DECL (stmts[4]), + args, complain, in_decl); + DECL_CONTEXT (omp_priv) = current_function_decl; + DECL_CONTEXT (omp_orig) = current_function_decl; + keep_next_level (true); + tree block = begin_omp_structured_block (); + tsubst_expr (stmts[5], args, complain, in_decl, false); + block = finish_omp_structured_block (block); + block = maybe_cleanup_point_expr_void (block); + cp_walk_tree (&block, cp_remove_omp_priv_cleanup_stmt, omp_priv, NULL); + add_decl_expr (omp_priv); + add_decl_expr (omp_orig); + finish_expr_stmt (block); + if (i == 7) + add_decl_expr (omp_orig); + } +} + +/* T is a postfix-expression that is not being used in a function + call. Return the substituted version of T. */ + +static tree +tsubst_non_call_postfix_expression (tree t, tree args, + tsubst_flags_t complain, + tree in_decl) +{ + if (TREE_CODE (t) == SCOPE_REF) + t = tsubst_qualified_id (t, args, complain, in_decl, + /*done=*/false, /*address_p=*/false); + else + t = tsubst_copy_and_build (t, args, complain, in_decl, + /*function_p=*/false, + /*integral_constant_expression_p=*/false); + + return t; +} + +/* Sentinel to disable certain warnings during template substitution. */ + +struct warning_sentinel { + int &flag; + int val; + warning_sentinel(int& flag, bool suppress=true) + : flag(flag), val(flag) { if (suppress) flag = 0; } + ~warning_sentinel() { flag = val; } +}; + +/* Like tsubst but deals with expressions and performs semantic + analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */ + +tree +tsubst_copy_and_build (tree t, + tree args, + tsubst_flags_t complain, + tree in_decl, + bool function_p, + bool integral_constant_expression_p) +{ +#define RETURN(EXP) do { retval = (EXP); goto out; } while(0) +#define RECUR(NODE) \ + tsubst_copy_and_build (NODE, args, complain, in_decl, \ + /*function_p=*/false, \ + integral_constant_expression_p) + + tree retval, op1; + location_t loc; + + if (t == NULL_TREE || t == error_mark_node) + return t; + + loc = input_location; + if (EXPR_HAS_LOCATION (t)) + input_location = EXPR_LOCATION (t); + + /* N3276 decltype magic only applies to calls at the top level or on the + right side of a comma. */ + tsubst_flags_t decltype_flag = (complain & tf_decltype); + complain &= ~tf_decltype; + + switch (TREE_CODE (t)) + { + case USING_DECL: + t = DECL_NAME (t); + /* Fall through. */ + case IDENTIFIER_NODE: + { + tree decl; + cp_id_kind idk; + bool non_integral_constant_expression_p; + const char *error_msg; + + if (IDENTIFIER_TYPENAME_P (t)) + { + tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl); + t = mangle_conv_op_name_for_type (new_type); + } + + /* Look up the name. */ + decl = lookup_name (t); + + /* By convention, expressions use ERROR_MARK_NODE to indicate + failure, not NULL_TREE. */ + if (decl == NULL_TREE) + decl = error_mark_node; + + decl = finish_id_expression (t, decl, NULL_TREE, + &idk, + integral_constant_expression_p, + /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx11), + &non_integral_constant_expression_p, + /*template_p=*/false, + /*done=*/true, + /*address_p=*/false, + /*template_arg_p=*/false, + &error_msg, + input_location); + if (error_msg) + error (error_msg); + if (!function_p && identifier_p (decl)) + { + if (complain & tf_error) + unqualified_name_lookup_error (decl); + decl = error_mark_node; + } + RETURN (decl); + } + + case TEMPLATE_ID_EXPR: + { + tree object; + tree templ = RECUR (TREE_OPERAND (t, 0)); + tree targs = TREE_OPERAND (t, 1); + + if (targs) + targs = tsubst_template_args (targs, args, complain, in_decl); + + if (TREE_CODE (templ) == COMPONENT_REF) + { + object = TREE_OPERAND (templ, 0); + templ = TREE_OPERAND (templ, 1); + } + else + object = NULL_TREE; + templ = lookup_template_function (templ, targs); + + if (object) + RETURN (build3 (COMPONENT_REF, TREE_TYPE (templ), + object, templ, NULL_TREE)); + else + RETURN (baselink_for_fns (templ)); + } + + case INDIRECT_REF: + { + tree r = RECUR (TREE_OPERAND (t, 0)); + + if (REFERENCE_REF_P (t)) + { + /* A type conversion to reference type will be enclosed in + such an indirect ref, but the substitution of the cast + will have also added such an indirect ref. */ + if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE) + r = convert_from_reference (r); + } + else + r = build_x_indirect_ref (input_location, r, RO_UNARY_STAR, + complain|decltype_flag); + RETURN (r); + } + + case NOP_EXPR: + RETURN (build_nop + (tsubst (TREE_TYPE (t), args, complain, in_decl), + RECUR (TREE_OPERAND (t, 0)))); + + case IMPLICIT_CONV_EXPR: + { + tree type = tsubst (TREE_TYPE (t), args, complain, in_decl); + tree expr = RECUR (TREE_OPERAND (t, 0)); + int flags = LOOKUP_IMPLICIT; + if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t)) + flags = LOOKUP_NORMAL; + RETURN (perform_implicit_conversion_flags (type, expr, complain, + flags)); + } + + case CONVERT_EXPR: + RETURN (build1 + (CONVERT_EXPR, + tsubst (TREE_TYPE (t), args, complain, in_decl), + RECUR (TREE_OPERAND (t, 0)))); + + case CAST_EXPR: + case REINTERPRET_CAST_EXPR: + case CONST_CAST_EXPR: + case DYNAMIC_CAST_EXPR: + case STATIC_CAST_EXPR: + { + tree type; + tree op, r = NULL_TREE; + + type = tsubst (TREE_TYPE (t), args, complain, in_decl); + if (integral_constant_expression_p + && !cast_valid_in_integral_constant_expression_p (type)) + { + if (complain & tf_error) + error ("a cast to a type other than an integral or " + "enumeration type cannot appear in a constant-expression"); + RETURN (error_mark_node); + } + + op = RECUR (TREE_OPERAND (t, 0)); + + warning_sentinel s(warn_useless_cast); + switch (TREE_CODE (t)) + { + case CAST_EXPR: + r = build_functional_cast (type, op, complain); + break; + case REINTERPRET_CAST_EXPR: + r = build_reinterpret_cast (type, op, complain); + break; + case CONST_CAST_EXPR: + r = build_const_cast (type, op, complain); + break; + case DYNAMIC_CAST_EXPR: + r = build_dynamic_cast (type, op, complain); + break; + case STATIC_CAST_EXPR: + r = build_static_cast (type, op, complain); + break; + default: + gcc_unreachable (); + } + + RETURN (r); + } + + case POSTDECREMENT_EXPR: + case POSTINCREMENT_EXPR: + op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0), + args, complain, in_decl); + RETURN (build_x_unary_op (input_location, TREE_CODE (t), op1, + complain|decltype_flag)); + + case PREDECREMENT_EXPR: + case PREINCREMENT_EXPR: + case NEGATE_EXPR: + case BIT_NOT_EXPR: + case ABS_EXPR: + case TRUTH_NOT_EXPR: + case UNARY_PLUS_EXPR: /* Unary + */ + case REALPART_EXPR: + case IMAGPART_EXPR: + RETURN (build_x_unary_op (input_location, TREE_CODE (t), + RECUR (TREE_OPERAND (t, 0)), + complain|decltype_flag)); + + case FIX_TRUNC_EXPR: + RETURN (cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)), + 0, complain)); + + case ADDR_EXPR: + op1 = TREE_OPERAND (t, 0); + if (TREE_CODE (op1) == LABEL_DECL) + RETURN (finish_label_address_expr (DECL_NAME (op1), + EXPR_LOCATION (op1))); + if (TREE_CODE (op1) == SCOPE_REF) + op1 = tsubst_qualified_id (op1, args, complain, in_decl, + /*done=*/true, /*address_p=*/true); + else + op1 = tsubst_non_call_postfix_expression (op1, args, complain, + in_decl); + RETURN (build_x_unary_op (input_location, ADDR_EXPR, op1, + complain|decltype_flag)); + + case PLUS_EXPR: + case MINUS_EXPR: + case MULT_EXPR: + case TRUNC_DIV_EXPR: + case CEIL_DIV_EXPR: + case FLOOR_DIV_EXPR: + case ROUND_DIV_EXPR: + case EXACT_DIV_EXPR: + case BIT_AND_EXPR: + case BIT_IOR_EXPR: + case BIT_XOR_EXPR: + case TRUNC_MOD_EXPR: + case FLOOR_MOD_EXPR: + case TRUTH_ANDIF_EXPR: + case TRUTH_ORIF_EXPR: + case TRUTH_AND_EXPR: + case TRUTH_OR_EXPR: + case RSHIFT_EXPR: + case LSHIFT_EXPR: + case RROTATE_EXPR: + case LROTATE_EXPR: + case EQ_EXPR: + case NE_EXPR: + case MAX_EXPR: + case MIN_EXPR: + case LE_EXPR: + case GE_EXPR: + case LT_EXPR: + case GT_EXPR: + case MEMBER_REF: + case DOTSTAR_EXPR: + { + warning_sentinel s1(warn_type_limits); + warning_sentinel s2(warn_div_by_zero); + tree r = build_x_binary_op + (input_location, TREE_CODE (t), + RECUR (TREE_OPERAND (t, 0)), + (TREE_NO_WARNING (TREE_OPERAND (t, 0)) + ? ERROR_MARK + : TREE_CODE (TREE_OPERAND (t, 0))), + RECUR (TREE_OPERAND (t, 1)), + (TREE_NO_WARNING (TREE_OPERAND (t, 1)) + ? ERROR_MARK + : TREE_CODE (TREE_OPERAND (t, 1))), + /*overload=*/NULL, + complain|decltype_flag); + if (EXPR_P (r) && TREE_NO_WARNING (t)) + TREE_NO_WARNING (r) = TREE_NO_WARNING (t); + + RETURN (r); + } + + case POINTER_PLUS_EXPR: + return fold_build_pointer_plus (RECUR (TREE_OPERAND (t, 0)), + RECUR (TREE_OPERAND (t, 1))); + + case SCOPE_REF: + RETURN (tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true, + /*address_p=*/false)); + case ARRAY_REF: + op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0), + args, complain, in_decl); + RETURN (build_x_array_ref (EXPR_LOCATION (t), op1, + RECUR (TREE_OPERAND (t, 1)), + complain|decltype_flag)); + + case ARRAY_NOTATION_REF: + { + tree start_index, length, stride; + op1 = tsubst_non_call_postfix_expression (ARRAY_NOTATION_ARRAY (t), + args, complain, in_decl); + start_index = RECUR (ARRAY_NOTATION_START (t)); + length = RECUR (ARRAY_NOTATION_LENGTH (t)); + stride = RECUR (ARRAY_NOTATION_STRIDE (t)); + RETURN (build_array_notation_ref (EXPR_LOCATION (t), op1, start_index, + length, stride, TREE_TYPE (op1))); + } + case SIZEOF_EXPR: + if (PACK_EXPANSION_P (TREE_OPERAND (t, 0))) + RETURN (tsubst_copy (t, args, complain, in_decl)); + /* Fall through */ + + case ALIGNOF_EXPR: + { + tree r; + + op1 = TREE_OPERAND (t, 0); + if (TREE_CODE (t) == SIZEOF_EXPR && SIZEOF_EXPR_TYPE_P (t)) + op1 = TREE_TYPE (op1); + if (!args) + { + /* When there are no ARGS, we are trying to evaluate a + non-dependent expression from the parser. Trying to do + the substitutions may not work. */ + if (!TYPE_P (op1)) + op1 = TREE_TYPE (op1); + } + else + { + ++cp_unevaluated_operand; + ++c_inhibit_evaluation_warnings; + if (TYPE_P (op1)) + op1 = tsubst (op1, args, complain, in_decl); + else + op1 = tsubst_copy_and_build (op1, args, complain, in_decl, + /*function_p=*/false, + /*integral_constant_expression_p=*/ + false); + --cp_unevaluated_operand; + --c_inhibit_evaluation_warnings; + } + if (TYPE_P (op1)) + r = cxx_sizeof_or_alignof_type (op1, TREE_CODE (t), + complain & tf_error); + else + r = cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t), + complain & tf_error); + if (TREE_CODE (t) == SIZEOF_EXPR && r != error_mark_node) + { + if (TREE_CODE (r) != SIZEOF_EXPR || TYPE_P (op1)) + { + if (!processing_template_decl && TYPE_P (op1)) + { + r = build_min (SIZEOF_EXPR, size_type_node, + build1 (NOP_EXPR, op1, error_mark_node)); + SIZEOF_EXPR_TYPE_P (r) = 1; + } + else + r = build_min (SIZEOF_EXPR, size_type_node, op1); + TREE_SIDE_EFFECTS (r) = 0; + TREE_READONLY (r) = 1; + } + SET_EXPR_LOCATION (r, EXPR_LOCATION (t)); + } + RETURN (r); + } + + case AT_ENCODE_EXPR: + { + op1 = TREE_OPERAND (t, 0); + ++cp_unevaluated_operand; + ++c_inhibit_evaluation_warnings; + op1 = tsubst_copy_and_build (op1, args, complain, in_decl, + /*function_p=*/false, + /*integral_constant_expression_p=*/false); + --cp_unevaluated_operand; + --c_inhibit_evaluation_warnings; + RETURN (objc_build_encode_expr (op1)); + } + + case NOEXCEPT_EXPR: + op1 = TREE_OPERAND (t, 0); + ++cp_unevaluated_operand; + ++c_inhibit_evaluation_warnings; + op1 = tsubst_copy_and_build (op1, args, complain, in_decl, + /*function_p=*/false, + /*integral_constant_expression_p=*/false); + --cp_unevaluated_operand; + --c_inhibit_evaluation_warnings; + RETURN (finish_noexcept_expr (op1, complain)); + + case MODOP_EXPR: + { + warning_sentinel s(warn_div_by_zero); + tree r = build_x_modify_expr + (EXPR_LOCATION (t), + RECUR (TREE_OPERAND (t, 0)), + TREE_CODE (TREE_OPERAND (t, 1)), + RECUR (TREE_OPERAND (t, 2)), + complain|decltype_flag); + /* TREE_NO_WARNING must be set if either the expression was + parenthesized or it uses an operator such as >>= rather + than plain assignment. In the former case, it was already + set and must be copied. In the latter case, + build_x_modify_expr sets it and it must not be reset + here. */ + if (TREE_NO_WARNING (t)) + TREE_NO_WARNING (r) = TREE_NO_WARNING (t); + + RETURN (r); + } + + case ARROW_EXPR: + op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0), + args, complain, in_decl); + /* Remember that there was a reference to this entity. */ + if (DECL_P (op1)) + mark_used (op1); + RETURN (build_x_arrow (input_location, op1, complain)); + + case NEW_EXPR: + { + tree placement = RECUR (TREE_OPERAND (t, 0)); + tree init = RECUR (TREE_OPERAND (t, 3)); + vec<tree, va_gc> *placement_vec; + vec<tree, va_gc> *init_vec; + tree ret; + + if (placement == NULL_TREE) + placement_vec = NULL; + else + { + placement_vec = make_tree_vector (); + for (; placement != NULL_TREE; placement = TREE_CHAIN (placement)) + vec_safe_push (placement_vec, TREE_VALUE (placement)); + } + + /* If there was an initializer in the original tree, but it + instantiated to an empty list, then we should pass a + non-NULL empty vector to tell build_new that it was an + empty initializer() rather than no initializer. This can + only happen when the initializer is a pack expansion whose + parameter packs are of length zero. */ + if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE) + init_vec = NULL; + else + { + init_vec = make_tree_vector (); + if (init == void_zero_node) + gcc_assert (init_vec != NULL); + else + { + for (; init != NULL_TREE; init = TREE_CHAIN (init)) + vec_safe_push (init_vec, TREE_VALUE (init)); + } + } + + ret = build_new (&placement_vec, + tsubst (TREE_OPERAND (t, 1), args, complain, in_decl), + RECUR (TREE_OPERAND (t, 2)), + &init_vec, + NEW_EXPR_USE_GLOBAL (t), + complain); + + if (placement_vec != NULL) + release_tree_vector (placement_vec); + if (init_vec != NULL) + release_tree_vector (init_vec); + + RETURN (ret); + } + + case DELETE_EXPR: + RETURN (delete_sanity + (RECUR (TREE_OPERAND (t, 0)), + RECUR (TREE_OPERAND (t, 1)), + DELETE_EXPR_USE_VEC (t), + DELETE_EXPR_USE_GLOBAL (t), + complain)); + + case COMPOUND_EXPR: + { + tree op0 = tsubst_copy_and_build (TREE_OPERAND (t, 0), args, + complain & ~tf_decltype, in_decl, + /*function_p=*/false, + integral_constant_expression_p); + RETURN (build_x_compound_expr (EXPR_LOCATION (t), + op0, + RECUR (TREE_OPERAND (t, 1)), + complain|decltype_flag)); + } + + case CALL_EXPR: + { + tree function; + vec<tree, va_gc> *call_args; + unsigned int nargs, i; + bool qualified_p; + bool koenig_p; + tree ret; + + function = CALL_EXPR_FN (t); + /* When we parsed the expression, we determined whether or + not Koenig lookup should be performed. */ + koenig_p = KOENIG_LOOKUP_P (t); + if (TREE_CODE (function) == SCOPE_REF) + { + qualified_p = true; + function = tsubst_qualified_id (function, args, complain, in_decl, + /*done=*/false, + /*address_p=*/false); + } + else if (koenig_p && identifier_p (function)) + { + /* Do nothing; calling tsubst_copy_and_build on an identifier + would incorrectly perform unqualified lookup again. + + Note that we can also have an IDENTIFIER_NODE if the earlier + unqualified lookup found a member function; in that case + koenig_p will be false and we do want to do the lookup + again to find the instantiated member function. + + FIXME but doing that causes c++/15272, so we need to stop + using IDENTIFIER_NODE in that situation. */ + qualified_p = false; + } + else + { + if (TREE_CODE (function) == COMPONENT_REF) + { + tree op = TREE_OPERAND (function, 1); + + qualified_p = (TREE_CODE (op) == SCOPE_REF + || (BASELINK_P (op) + && BASELINK_QUALIFIED_P (op))); + } + else + qualified_p = false; + + if (TREE_CODE (function) == ADDR_EXPR + && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) + /* Avoid error about taking the address of a constructor. */ + function = TREE_OPERAND (function, 0); + + function = tsubst_copy_and_build (function, args, complain, + in_decl, + !qualified_p, + integral_constant_expression_p); + + if (BASELINK_P (function)) + qualified_p = true; + } + + nargs = call_expr_nargs (t); + call_args = make_tree_vector (); + for (i = 0; i < nargs; ++i) + { + tree arg = CALL_EXPR_ARG (t, i); + + if (!PACK_EXPANSION_P (arg)) + vec_safe_push (call_args, RECUR (CALL_EXPR_ARG (t, i))); + else + { + /* Expand the pack expansion and push each entry onto + CALL_ARGS. */ + arg = tsubst_pack_expansion (arg, args, complain, in_decl); + if (TREE_CODE (arg) == TREE_VEC) + { + unsigned int len, j; + + len = TREE_VEC_LENGTH (arg); + for (j = 0; j < len; ++j) + { + tree value = TREE_VEC_ELT (arg, j); + if (value != NULL_TREE) + value = convert_from_reference (value); + vec_safe_push (call_args, value); + } + } + else + { + /* A partial substitution. Add one entry. */ + vec_safe_push (call_args, arg); + } + } + } + + /* We do not perform argument-dependent lookup if normal + lookup finds a non-function, in accordance with the + expected resolution of DR 218. */ + if (koenig_p + && ((is_overloaded_fn (function) + /* If lookup found a member function, the Koenig lookup is + not appropriate, even if an unqualified-name was used + to denote the function. */ + && !DECL_FUNCTION_MEMBER_P (get_first_fn (function))) + || identifier_p (function)) + /* Only do this when substitution turns a dependent call + into a non-dependent call. */ + && type_dependent_expression_p_push (t) + && !any_type_dependent_arguments_p (call_args)) + function = perform_koenig_lookup (function, call_args, tf_none); + + if (identifier_p (function) + && !any_type_dependent_arguments_p (call_args)) + { + if (koenig_p && (complain & tf_warning_or_error)) + { + /* For backwards compatibility and good diagnostics, try + the unqualified lookup again if we aren't in SFINAE + context. */ + tree unq = (tsubst_copy_and_build + (function, args, complain, in_decl, true, + integral_constant_expression_p)); + if (unq == error_mark_node) + RETURN (error_mark_node); + + if (unq != function) + { + tree fn = unq; + if (INDIRECT_REF_P (fn)) + fn = TREE_OPERAND (fn, 0); + if (TREE_CODE (fn) == COMPONENT_REF) + fn = TREE_OPERAND (fn, 1); + if (is_overloaded_fn (fn)) + fn = get_first_fn (fn); + if (permerror (EXPR_LOC_OR_LOC (t, input_location), + "%qD was not declared in this scope, " + "and no declarations were found by " + "argument-dependent lookup at the point " + "of instantiation", function)) + { + if (!DECL_P (fn)) + /* Can't say anything more. */; + else if (DECL_CLASS_SCOPE_P (fn)) + { + location_t loc = EXPR_LOC_OR_LOC (t, + input_location); + inform (loc, + "declarations in dependent base %qT are " + "not found by unqualified lookup", + DECL_CLASS_CONTEXT (fn)); + if (current_class_ptr) + inform (loc, + "use %<this->%D%> instead", function); + else + inform (loc, + "use %<%T::%D%> instead", + current_class_name, function); + } + else + inform (0, "%q+D declared here, later in the " + "translation unit", fn); + } + function = unq; + } + } + if (identifier_p (function)) + { + if (complain & tf_error) + unqualified_name_lookup_error (function); + release_tree_vector (call_args); + RETURN (error_mark_node); + } + } + + /* Remember that there was a reference to this entity. */ + if (DECL_P (function)) + mark_used (function); + + /* Put back tf_decltype for the actual call. */ + complain |= decltype_flag; + + if (TREE_CODE (function) == OFFSET_REF) + ret = build_offset_ref_call_from_tree (function, &call_args, + complain); + else if (TREE_CODE (function) == COMPONENT_REF) + { + tree instance = TREE_OPERAND (function, 0); + tree fn = TREE_OPERAND (function, 1); + + if (processing_template_decl + && (type_dependent_expression_p (instance) + || (!BASELINK_P (fn) + && TREE_CODE (fn) != FIELD_DECL) + || type_dependent_expression_p (fn) + || any_type_dependent_arguments_p (call_args))) + ret = build_nt_call_vec (function, call_args); + else if (!BASELINK_P (fn)) + ret = finish_call_expr (function, &call_args, + /*disallow_virtual=*/false, + /*koenig_p=*/false, + complain); + else + ret = (build_new_method_call + (instance, fn, + &call_args, NULL_TREE, + qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL, + /*fn_p=*/NULL, + complain)); + } + else + ret = finish_call_expr (function, &call_args, + /*disallow_virtual=*/qualified_p, + koenig_p, + complain); + + release_tree_vector (call_args); + + RETURN (ret); + } + + case COND_EXPR: + { + tree cond = RECUR (TREE_OPERAND (t, 0)); + tree exp1, exp2; + + if (TREE_CODE (cond) == INTEGER_CST) + { + if (integer_zerop (cond)) + { + ++c_inhibit_evaluation_warnings; + exp1 = RECUR (TREE_OPERAND (t, 1)); + --c_inhibit_evaluation_warnings; + exp2 = RECUR (TREE_OPERAND (t, 2)); + } + else + { + exp1 = RECUR (TREE_OPERAND (t, 1)); + ++c_inhibit_evaluation_warnings; + exp2 = RECUR (TREE_OPERAND (t, 2)); + --c_inhibit_evaluation_warnings; + } + } + else + { + exp1 = RECUR (TREE_OPERAND (t, 1)); + exp2 = RECUR (TREE_OPERAND (t, 2)); + } + + RETURN (build_x_conditional_expr (EXPR_LOCATION (t), + cond, exp1, exp2, complain)); + } + + case PSEUDO_DTOR_EXPR: + RETURN (finish_pseudo_destructor_expr + (RECUR (TREE_OPERAND (t, 0)), + RECUR (TREE_OPERAND (t, 1)), + tsubst (TREE_OPERAND (t, 2), args, complain, in_decl), + input_location)); + + case TREE_LIST: + { + tree purpose, value, chain; + + if (t == void_list_node) + RETURN (t); + + if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t))) + || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t)))) + { + /* We have pack expansions, so expand those and + create a new list out of it. */ + tree purposevec = NULL_TREE; + tree valuevec = NULL_TREE; + tree chain; + int i, len = -1; + + /* Expand the argument expressions. */ + if (TREE_PURPOSE (t)) + purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args, + complain, in_decl); + if (TREE_VALUE (t)) + valuevec = tsubst_pack_expansion (TREE_VALUE (t), args, + complain, in_decl); + + /* Build the rest of the list. */ + chain = TREE_CHAIN (t); + if (chain && chain != void_type_node) + chain = RECUR (chain); + + /* Determine the number of arguments. */ + if (purposevec && TREE_CODE (purposevec) == TREE_VEC) + { + len = TREE_VEC_LENGTH (purposevec); + gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec)); + } + else if (TREE_CODE (valuevec) == TREE_VEC) + len = TREE_VEC_LENGTH (valuevec); + else + { + /* Since we only performed a partial substitution into + the argument pack, we only RETURN (a single list + node. */ + if (purposevec == TREE_PURPOSE (t) + && valuevec == TREE_VALUE (t) + && chain == TREE_CHAIN (t)) + RETURN (t); + + RETURN (tree_cons (purposevec, valuevec, chain)); + } + + /* Convert the argument vectors into a TREE_LIST */ + i = len; + while (i > 0) + { + /* Grab the Ith values. */ + i--; + purpose = purposevec ? TREE_VEC_ELT (purposevec, i) + : NULL_TREE; + value + = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i)) + : NULL_TREE; + + /* Build the list (backwards). */ + chain = tree_cons (purpose, value, chain); + } + + RETURN (chain); + } + + purpose = TREE_PURPOSE (t); + if (purpose) + purpose = RECUR (purpose); + value = TREE_VALUE (t); + if (value) + value = RECUR (value); + chain = TREE_CHAIN (t); + if (chain && chain != void_type_node) + chain = RECUR (chain); + if (purpose == TREE_PURPOSE (t) + && value == TREE_VALUE (t) + && chain == TREE_CHAIN (t)) + RETURN (t); + RETURN (tree_cons (purpose, value, chain)); + } + + case COMPONENT_REF: + { + tree object; + tree object_type; + tree member; + tree r; + + object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0), + args, complain, in_decl); + /* Remember that there was a reference to this entity. */ + if (DECL_P (object)) + mark_used (object); + object_type = TREE_TYPE (object); + + member = TREE_OPERAND (t, 1); + if (BASELINK_P (member)) + member = tsubst_baselink (member, + non_reference (TREE_TYPE (object)), + args, complain, in_decl); + else + member = tsubst_copy (member, args, complain, in_decl); + if (member == error_mark_node) + RETURN (error_mark_node); + + if (type_dependent_expression_p (object)) + /* We can't do much here. */; + else if (!CLASS_TYPE_P (object_type)) + { + if (scalarish_type_p (object_type)) + { + tree s = NULL_TREE; + tree dtor = member; + + if (TREE_CODE (dtor) == SCOPE_REF) + { + s = TREE_OPERAND (dtor, 0); + dtor = TREE_OPERAND (dtor, 1); + } + if (TREE_CODE (dtor) == BIT_NOT_EXPR) + { + dtor = TREE_OPERAND (dtor, 0); + if (TYPE_P (dtor)) + RETURN (finish_pseudo_destructor_expr + (object, s, dtor, input_location)); + } + } + } + else if (TREE_CODE (member) == SCOPE_REF + && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR) + { + /* Lookup the template functions now that we know what the + scope is. */ + tree scope = TREE_OPERAND (member, 0); + tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0); + tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1); + member = lookup_qualified_name (scope, tmpl, + /*is_type_p=*/false, + /*complain=*/false); + if (BASELINK_P (member)) + { + BASELINK_FUNCTIONS (member) + = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member), + args); + member = (adjust_result_of_qualified_name_lookup + (member, BINFO_TYPE (BASELINK_BINFO (member)), + object_type)); + } + else + { + qualified_name_lookup_error (scope, tmpl, member, + input_location); + RETURN (error_mark_node); + } + } + else if (TREE_CODE (member) == SCOPE_REF + && !CLASS_TYPE_P (TREE_OPERAND (member, 0)) + && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL) + { + if (complain & tf_error) + { + if (TYPE_P (TREE_OPERAND (member, 0))) + error ("%qT is not a class or namespace", + TREE_OPERAND (member, 0)); + else + error ("%qD is not a class or namespace", + TREE_OPERAND (member, 0)); + } + RETURN (error_mark_node); + } + else if (TREE_CODE (member) == FIELD_DECL) + { + r = finish_non_static_data_member (member, object, NULL_TREE); + if (TREE_CODE (r) == COMPONENT_REF) + REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t); + RETURN (r); + } + + r = finish_class_member_access_expr (object, member, + /*template_p=*/false, + complain); + if (TREE_CODE (r) == COMPONENT_REF) + REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t); + RETURN (r); + } + + case THROW_EXPR: + RETURN (build_throw + (RECUR (TREE_OPERAND (t, 0)))); + + case CONSTRUCTOR: + { + vec<constructor_elt, va_gc> *n; + constructor_elt *ce; + unsigned HOST_WIDE_INT idx; + tree type = tsubst (TREE_TYPE (t), args, complain, in_decl); + bool process_index_p; + int newlen; + bool need_copy_p = false; + tree r; + + if (type == error_mark_node) + RETURN (error_mark_node); + + /* digest_init will do the wrong thing if we let it. */ + if (type && TYPE_PTRMEMFUNC_P (type)) + RETURN (t); + + /* We do not want to process the index of aggregate + initializers as they are identifier nodes which will be + looked up by digest_init. */ + process_index_p = !(type && MAYBE_CLASS_TYPE_P (type)); + + n = vec_safe_copy (CONSTRUCTOR_ELTS (t)); + newlen = vec_safe_length (n); + FOR_EACH_VEC_SAFE_ELT (n, idx, ce) + { + if (ce->index && process_index_p + /* An identifier index is looked up in the type + being initialized, not the current scope. */ + && TREE_CODE (ce->index) != IDENTIFIER_NODE) + ce->index = RECUR (ce->index); + + if (PACK_EXPANSION_P (ce->value)) + { + /* Substitute into the pack expansion. */ + ce->value = tsubst_pack_expansion (ce->value, args, complain, + in_decl); + + if (ce->value == error_mark_node + || PACK_EXPANSION_P (ce->value)) + ; + else if (TREE_VEC_LENGTH (ce->value) == 1) + /* Just move the argument into place. */ + ce->value = TREE_VEC_ELT (ce->value, 0); + else + { + /* Update the length of the final CONSTRUCTOR + arguments vector, and note that we will need to + copy.*/ + newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1; + need_copy_p = true; + } + } + else + ce->value = RECUR (ce->value); + } + + if (need_copy_p) + { + vec<constructor_elt, va_gc> *old_n = n; + + vec_alloc (n, newlen); + FOR_EACH_VEC_ELT (*old_n, idx, ce) + { + if (TREE_CODE (ce->value) == TREE_VEC) + { + int i, len = TREE_VEC_LENGTH (ce->value); + for (i = 0; i < len; ++i) + CONSTRUCTOR_APPEND_ELT (n, 0, + TREE_VEC_ELT (ce->value, i)); + } + else + CONSTRUCTOR_APPEND_ELT (n, 0, ce->value); + } + } + + r = build_constructor (init_list_type_node, n); + CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t); + + if (TREE_HAS_CONSTRUCTOR (t)) + RETURN (finish_compound_literal (type, r, complain)); + + TREE_TYPE (r) = type; + RETURN (r); + } + + case TYPEID_EXPR: + { + tree operand_0 = TREE_OPERAND (t, 0); + if (TYPE_P (operand_0)) + { + operand_0 = tsubst (operand_0, args, complain, in_decl); + RETURN (get_typeid (operand_0, complain)); + } + else + { + operand_0 = RECUR (operand_0); + RETURN (build_typeid (operand_0, complain)); + } + } + + case VAR_DECL: + if (!args) + RETURN (t); + else if (DECL_PACK_P (t)) + { + /* We don't build decls for an instantiation of a + variadic capture proxy, we instantiate the elements + when needed. */ + gcc_assert (DECL_HAS_VALUE_EXPR_P (t)); + return RECUR (DECL_VALUE_EXPR (t)); + } + /* Fall through */ + + case PARM_DECL: + { + tree r = tsubst_copy (t, args, complain, in_decl); + + if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE) + /* If the original type was a reference, we'll be wrapped in + the appropriate INDIRECT_REF. */ + r = convert_from_reference (r); + RETURN (r); + } + + case VA_ARG_EXPR: + RETURN (build_x_va_arg (EXPR_LOCATION (t), + RECUR (TREE_OPERAND (t, 0)), + tsubst (TREE_TYPE (t), args, complain, in_decl))); + + case OFFSETOF_EXPR: + RETURN (finish_offsetof (RECUR (TREE_OPERAND (t, 0)))); + + case TRAIT_EXPR: + { + tree type1 = tsubst (TRAIT_EXPR_TYPE1 (t), args, + complain, in_decl); + + tree type2 = TRAIT_EXPR_TYPE2 (t); + if (type2) + type2 = tsubst (type2, args, complain, in_decl); + + RETURN (finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2)); + } + + case STMT_EXPR: + { + tree old_stmt_expr = cur_stmt_expr; + tree stmt_expr = begin_stmt_expr (); + + cur_stmt_expr = stmt_expr; + tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl, + integral_constant_expression_p); + stmt_expr = finish_stmt_expr (stmt_expr, false); + cur_stmt_expr = old_stmt_expr; + + /* If the resulting list of expression statement is empty, + fold it further into void_zero_node. */ + if (empty_expr_stmt_p (stmt_expr)) + stmt_expr = void_zero_node; + + RETURN (stmt_expr); + } + + case LAMBDA_EXPR: + { + tree r = build_lambda_expr (); + + tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE); + LAMBDA_EXPR_CLOSURE (r) = type; + CLASSTYPE_LAMBDA_EXPR (type) = r; + + LAMBDA_EXPR_LOCATION (r) + = LAMBDA_EXPR_LOCATION (t); + LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r) + = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t); + LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t); + LAMBDA_EXPR_DISCRIMINATOR (r) + = (LAMBDA_EXPR_DISCRIMINATOR (t)); + /* For a function scope, we want to use tsubst so that we don't + complain about referring to an auto function before its return + type has been deduced. Otherwise, we want to use tsubst_copy so + that we look up the existing field/parameter/variable rather + than build a new one. */ + tree scope = LAMBDA_EXPR_EXTRA_SCOPE (t); + if (scope && TREE_CODE (scope) == FUNCTION_DECL) + scope = tsubst (scope, args, complain, in_decl); + else if (scope && TREE_CODE (scope) == PARM_DECL) + { + /* Look up the parameter we want directly, as tsubst_copy + doesn't do what we need. */ + tree fn = tsubst (DECL_CONTEXT (scope), args, complain, in_decl); + tree parm = FUNCTION_FIRST_USER_PARM (fn); + while (DECL_PARM_INDEX (parm) != DECL_PARM_INDEX (scope)) + parm = DECL_CHAIN (parm); + scope = parm; + /* FIXME Work around the parm not having DECL_CONTEXT set. */ + if (DECL_CONTEXT (scope) == NULL_TREE) + DECL_CONTEXT (scope) = fn; + } + else + scope = RECUR (scope); + LAMBDA_EXPR_EXTRA_SCOPE (r) = scope; + LAMBDA_EXPR_RETURN_TYPE (r) + = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl); + + gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE + && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL); + + /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */ + determine_visibility (TYPE_NAME (type)); + /* Now that we know visibility, instantiate the type so we have a + declaration of the op() for later calls to lambda_function. */ + complete_type (type); + + LAMBDA_EXPR_THIS_CAPTURE (r) = NULL_TREE; + + RETURN (build_lambda_object (r)); + } + + case TARGET_EXPR: + /* We can get here for a constant initializer of non-dependent type. + FIXME stop folding in cp_parser_initializer_clause. */ + { + tree r = get_target_expr_sfinae (RECUR (TARGET_EXPR_INITIAL (t)), + complain); + RETURN (r); + } + + case TRANSACTION_EXPR: + RETURN (tsubst_expr(t, args, complain, in_decl, + integral_constant_expression_p)); + + case PAREN_EXPR: + RETURN (finish_parenthesized_expr (RECUR (TREE_OPERAND (t, 0)))); + + case VEC_PERM_EXPR: + RETURN (build_x_vec_perm_expr (input_location, + RECUR (TREE_OPERAND (t, 0)), + RECUR (TREE_OPERAND (t, 1)), + RECUR (TREE_OPERAND (t, 2)), + complain)); + + default: + /* Handle Objective-C++ constructs, if appropriate. */ + { + tree subst + = objcp_tsubst_copy_and_build (t, args, complain, + in_decl, /*function_p=*/false); + if (subst) + RETURN (subst); + } + RETURN (tsubst_copy (t, args, complain, in_decl)); + } + +#undef RECUR +#undef RETURN + out: + input_location = loc; + return retval; +} + +/* Verify that the instantiated ARGS are valid. For type arguments, + make sure that the type's linkage is ok. For non-type arguments, + make sure they are constants if they are integral or enumerations. + Emit an error under control of COMPLAIN, and return TRUE on error. */ + +static bool +check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain) +{ + if (dependent_template_arg_p (t)) + return false; + if (ARGUMENT_PACK_P (t)) + { + tree vec = ARGUMENT_PACK_ARGS (t); + int len = TREE_VEC_LENGTH (vec); + bool result = false; + int i; + + for (i = 0; i < len; ++i) + if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain)) + result = true; + return result; + } + else if (TYPE_P (t)) + { + /* [basic.link]: A name with no linkage (notably, the name + of a class or enumeration declared in a local scope) + shall not be used to declare an entity with linkage. + This implies that names with no linkage cannot be used as + template arguments + + DR 757 relaxes this restriction for C++0x. */ + tree nt = (cxx_dialect > cxx98 ? NULL_TREE + : no_linkage_check (t, /*relaxed_p=*/false)); + + if (nt) + { + /* DR 488 makes use of a type with no linkage cause + type deduction to fail. */ + if (complain & tf_error) + { + if (TYPE_ANONYMOUS_P (nt)) + error ("%qT is/uses anonymous type", t); + else + error ("template argument for %qD uses local type %qT", + tmpl, t); + } + return true; + } + /* In order to avoid all sorts of complications, we do not + allow variably-modified types as template arguments. */ + else if (variably_modified_type_p (t, NULL_TREE)) + { + if (complain & tf_error) + error ("%qT is a variably modified type", t); + return true; + } + } + /* Class template and alias template arguments should be OK. */ + else if (DECL_TYPE_TEMPLATE_P (t)) + ; + /* A non-type argument of integral or enumerated type must be a + constant. */ + else if (TREE_TYPE (t) + && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t)) + && !TREE_CONSTANT (t)) + { + if (complain & tf_error) + error ("integral expression %qE is not constant", t); + return true; + } + return false; +} + +static bool +check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain) +{ + int ix, len = DECL_NTPARMS (tmpl); + bool result = false; + + for (ix = 0; ix != len; ix++) + { + if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain)) + result = true; + } + if (result && (complain & tf_error)) + error (" trying to instantiate %qD", tmpl); + return result; +} + +/* We're out of SFINAE context now, so generate diagnostics for the access + errors we saw earlier when instantiating D from TMPL and ARGS. */ + +static void +recheck_decl_substitution (tree d, tree tmpl, tree args) +{ + tree pattern = DECL_TEMPLATE_RESULT (tmpl); + tree type = TREE_TYPE (pattern); + location_t loc = input_location; + + push_access_scope (d); + push_deferring_access_checks (dk_no_deferred); + input_location = DECL_SOURCE_LOCATION (pattern); + tsubst (type, args, tf_warning_or_error, d); + input_location = loc; + pop_deferring_access_checks (); + pop_access_scope (d); +} + +/* Instantiate the indicated variable, function, or alias template TMPL with + the template arguments in TARG_PTR. */ + +static tree +instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain) +{ + tree targ_ptr = orig_args; + tree fndecl; + tree gen_tmpl; + tree spec; + bool access_ok = true; + + if (tmpl == error_mark_node) + return error_mark_node; + + gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL); + + /* If this function is a clone, handle it specially. */ + if (DECL_CLONED_FUNCTION_P (tmpl)) + { + tree spec; + tree clone; + + /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have + DECL_CLONED_FUNCTION. */ + spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl), + targ_ptr, complain); + if (spec == error_mark_node) + return error_mark_node; + + /* Look for the clone. */ + FOR_EACH_CLONE (clone, spec) + if (DECL_NAME (clone) == DECL_NAME (tmpl)) + return clone; + /* We should always have found the clone by now. */ + gcc_unreachable (); + return NULL_TREE; + } + + if (targ_ptr == error_mark_node) + return error_mark_node; + + /* Check to see if we already have this specialization. */ + gen_tmpl = most_general_template (tmpl); + if (tmpl != gen_tmpl) + /* The TMPL is a partial instantiation. To get a full set of + arguments we must add the arguments used to perform the + partial instantiation. */ + targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl), + targ_ptr); + + /* It would be nice to avoid hashing here and then again in tsubst_decl, + but it doesn't seem to be on the hot path. */ + spec = retrieve_specialization (gen_tmpl, targ_ptr, 0); + + gcc_assert (tmpl == gen_tmpl + || ((fndecl = retrieve_specialization (tmpl, orig_args, 0)) + == spec) + || fndecl == NULL_TREE); + + if (spec != NULL_TREE) + { + if (FNDECL_HAS_ACCESS_ERRORS (spec)) + { + if (complain & tf_error) + recheck_decl_substitution (spec, gen_tmpl, targ_ptr); + return error_mark_node; + } + return spec; + } + + if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr), + complain)) + return error_mark_node; + + /* We are building a FUNCTION_DECL, during which the access of its + parameters and return types have to be checked. However this + FUNCTION_DECL which is the desired context for access checking + is not built yet. We solve this chicken-and-egg problem by + deferring all checks until we have the FUNCTION_DECL. */ + push_deferring_access_checks (dk_deferred); + + /* Instantiation of the function happens in the context of the function + template, not the context of the overload resolution we're doing. */ + push_to_top_level (); + /* If there are dependent arguments, e.g. because we're doing partial + ordering, make sure processing_template_decl stays set. */ + if (uses_template_parms (targ_ptr)) + ++processing_template_decl; + if (DECL_CLASS_SCOPE_P (gen_tmpl)) + { + tree ctx = tsubst (DECL_CONTEXT (gen_tmpl), targ_ptr, + complain, gen_tmpl); + push_nested_class (ctx); + } + /* Substitute template parameters to obtain the specialization. */ + fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl), + targ_ptr, complain, gen_tmpl); + if (DECL_CLASS_SCOPE_P (gen_tmpl)) + pop_nested_class (); + pop_from_top_level (); + + if (fndecl == error_mark_node) + { + pop_deferring_access_checks (); + return error_mark_node; + } + + /* The DECL_TI_TEMPLATE should always be the immediate parent + template, not the most general template. */ + DECL_TI_TEMPLATE (fndecl) = tmpl; + + /* Now we know the specialization, compute access previously + deferred. */ + push_access_scope (fndecl); + if (!perform_deferred_access_checks (complain)) + access_ok = false; + pop_access_scope (fndecl); + pop_deferring_access_checks (); + + /* If we've just instantiated the main entry point for a function, + instantiate all the alternate entry points as well. We do this + by cloning the instantiation of the main entry point, not by + instantiating the template clones. */ + if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl))) + clone_function_decl (fndecl, /*update_method_vec_p=*/0); + + if (!access_ok) + { + if (!(complain & tf_error)) + { + /* Remember to reinstantiate when we're out of SFINAE so the user + can see the errors. */ + FNDECL_HAS_ACCESS_ERRORS (fndecl) = true; + } + return error_mark_node; + } + return fndecl; +} + +/* Wrapper for instantiate_template_1. */ + +tree +instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain) +{ + tree ret; + timevar_push (TV_TEMPLATE_INST); + ret = instantiate_template_1 (tmpl, orig_args, complain); + timevar_pop (TV_TEMPLATE_INST); + return ret; +} + +/* Instantiate the alias template TMPL with ARGS. Also push a template + instantiation level, which instantiate_template doesn't do because + functions and variables have sufficient context established by the + callers. */ + +static tree +instantiate_alias_template (tree tmpl, tree args, tsubst_flags_t complain) +{ + struct pending_template *old_last_pend = last_pending_template; + struct tinst_level *old_error_tinst = last_error_tinst_level; + if (tmpl == error_mark_node || args == error_mark_node) + return error_mark_node; + tree tinst = build_tree_list (tmpl, args); + if (!push_tinst_level (tinst)) + { + ggc_free (tinst); + return error_mark_node; + } + + args = + coerce_innermost_template_parms (DECL_TEMPLATE_PARMS (tmpl), + args, tmpl, complain, + /*require_all_args=*/true, + /*use_default_args=*/true); + + tree r = instantiate_template (tmpl, args, complain); + pop_tinst_level (); + /* We can't free this if a pending_template entry or last_error_tinst_level + is pointing at it. */ + if (last_pending_template == old_last_pend + && last_error_tinst_level == old_error_tinst) + ggc_free (tinst); + + return r; +} + +/* PARM is a template parameter pack for FN. Returns true iff + PARM is used in a deducible way in the argument list of FN. */ + +static bool +pack_deducible_p (tree parm, tree fn) +{ + tree t = FUNCTION_FIRST_USER_PARMTYPE (fn); + for (; t; t = TREE_CHAIN (t)) + { + tree type = TREE_VALUE (t); + tree packs; + if (!PACK_EXPANSION_P (type)) + continue; + for (packs = PACK_EXPANSION_PARAMETER_PACKS (type); + packs; packs = TREE_CHAIN (packs)) + if (TREE_VALUE (packs) == parm) + { + /* The template parameter pack is used in a function parameter + pack. If this is the end of the parameter list, the + template parameter pack is deducible. */ + if (TREE_CHAIN (t) == void_list_node) + return true; + else + /* Otherwise, not. Well, it could be deduced from + a non-pack parameter, but doing so would end up with + a deduction mismatch, so don't bother. */ + return false; + } + } + /* The template parameter pack isn't used in any function parameter + packs, but it might be used deeper, e.g. tuple<Args...>. */ + return true; +} + +/* The FN is a TEMPLATE_DECL for a function. ARGS is an array with + NARGS elements of the arguments that are being used when calling + it. TARGS is a vector into which the deduced template arguments + are placed. + + Returns either a FUNCTION_DECL for the matching specialization of FN or + NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is + true, diagnostics will be printed to explain why it failed. + + If FN is a conversion operator, or we are trying to produce a specific + specialization, RETURN_TYPE is the return type desired. + + The EXPLICIT_TARGS are explicit template arguments provided via a + template-id. + + The parameter STRICT is one of: + + DEDUCE_CALL: + We are deducing arguments for a function call, as in + [temp.deduct.call]. + + DEDUCE_CONV: + We are deducing arguments for a conversion function, as in + [temp.deduct.conv]. + + DEDUCE_EXACT: + We are deducing arguments when doing an explicit instantiation + as in [temp.explicit], when determining an explicit specialization + as in [temp.expl.spec], or when taking the address of a function + template, as in [temp.deduct.funcaddr]. */ + +tree +fn_type_unification (tree fn, + tree explicit_targs, + tree targs, + const tree *args, + unsigned int nargs, + tree return_type, + unification_kind_t strict, + int flags, + bool explain_p, + bool decltype_p) +{ + tree parms; + tree fntype; + tree decl = NULL_TREE; + tsubst_flags_t complain = (explain_p ? tf_warning_or_error : tf_none); + bool ok; + static int deduction_depth; + struct pending_template *old_last_pend = last_pending_template; + struct tinst_level *old_error_tinst = last_error_tinst_level; + tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn); + tree tinst; + tree r = error_mark_node; + + if (decltype_p) + complain |= tf_decltype; + + /* In C++0x, it's possible to have a function template whose type depends + on itself recursively. This is most obvious with decltype, but can also + occur with enumeration scope (c++/48969). So we need to catch infinite + recursion and reject the substitution at deduction time; this function + will return error_mark_node for any repeated substitution. + + This also catches excessive recursion such as when f<N> depends on + f<N-1> across all integers, and returns error_mark_node for all the + substitutions back up to the initial one. + + This is, of course, not reentrant. */ + if (excessive_deduction_depth) + return error_mark_node; + tinst = build_tree_list (fn, NULL_TREE); + ++deduction_depth; + + gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL); + + fntype = TREE_TYPE (fn); + if (explicit_targs) + { + /* [temp.deduct] + + The specified template arguments must match the template + parameters in kind (i.e., type, nontype, template), and there + must not be more arguments than there are parameters; + otherwise type deduction fails. + + Nontype arguments must match the types of the corresponding + nontype template parameters, or must be convertible to the + types of the corresponding nontype parameters as specified in + _temp.arg.nontype_, otherwise type deduction fails. + + All references in the function type of the function template + to the corresponding template parameters are replaced by the + specified template argument values. If a substitution in a + template parameter or in the function type of the function + template results in an invalid type, type deduction fails. */ + int i, len = TREE_VEC_LENGTH (tparms); + location_t loc = input_location; + bool incomplete = false; + + /* Adjust any explicit template arguments before entering the + substitution context. */ + explicit_targs + = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, + complain, + /*require_all_args=*/false, + /*use_default_args=*/false)); + if (explicit_targs == error_mark_node) + goto fail; + + /* Substitute the explicit args into the function type. This is + necessary so that, for instance, explicitly declared function + arguments can match null pointed constants. If we were given + an incomplete set of explicit args, we must not do semantic + processing during substitution as we could create partial + instantiations. */ + for (i = 0; i < len; i++) + { + tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i)); + bool parameter_pack = false; + tree targ = TREE_VEC_ELT (explicit_targs, i); + + /* Dig out the actual parm. */ + if (TREE_CODE (parm) == TYPE_DECL + || TREE_CODE (parm) == TEMPLATE_DECL) + { + parm = TREE_TYPE (parm); + parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm); + } + else if (TREE_CODE (parm) == PARM_DECL) + { + parm = DECL_INITIAL (parm); + parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm); + } + + if (!parameter_pack && targ == NULL_TREE) + /* No explicit argument for this template parameter. */ + incomplete = true; + + if (parameter_pack && pack_deducible_p (parm, fn)) + { + /* Mark the argument pack as "incomplete". We could + still deduce more arguments during unification. + We remove this mark in type_unification_real. */ + if (targ) + { + ARGUMENT_PACK_INCOMPLETE_P(targ) = 1; + ARGUMENT_PACK_EXPLICIT_ARGS (targ) + = ARGUMENT_PACK_ARGS (targ); + } + + /* We have some incomplete argument packs. */ + incomplete = true; + } + } + + TREE_VALUE (tinst) = explicit_targs; + if (!push_tinst_level (tinst)) + { + excessive_deduction_depth = true; + goto fail; + } + processing_template_decl += incomplete; + input_location = DECL_SOURCE_LOCATION (fn); + /* Ignore any access checks; we'll see them again in + instantiate_template and they might have the wrong + access path at this point. */ + push_deferring_access_checks (dk_deferred); + fntype = tsubst (TREE_TYPE (fn), explicit_targs, + complain | tf_partial, NULL_TREE); + pop_deferring_access_checks (); + input_location = loc; + processing_template_decl -= incomplete; + pop_tinst_level (); + + if (fntype == error_mark_node) + goto fail; + + /* Place the explicitly specified arguments in TARGS. */ + for (i = NUM_TMPL_ARGS (explicit_targs); i--;) + TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (explicit_targs, i); + } + + /* Never do unification on the 'this' parameter. */ + parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype)); + + if (return_type) + { + tree *new_args; + + parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms); + new_args = XALLOCAVEC (tree, nargs + 1); + new_args[0] = return_type; + memcpy (new_args + 1, args, nargs * sizeof (tree)); + args = new_args; + ++nargs; + } + + /* We allow incomplete unification without an error message here + because the standard doesn't seem to explicitly prohibit it. Our + callers must be ready to deal with unification failures in any + event. */ + + TREE_VALUE (tinst) = targs; + /* If we aren't explaining yet, push tinst context so we can see where + any errors (e.g. from class instantiations triggered by instantiation + of default template arguments) come from. If we are explaining, this + context is redundant. */ + if (!explain_p && !push_tinst_level (tinst)) + { + excessive_deduction_depth = true; + goto fail; + } + + /* type_unification_real will pass back any access checks from default + template argument substitution. */ + vec<deferred_access_check, va_gc> *checks; + checks = NULL; + + ok = !type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn), + targs, parms, args, nargs, /*subr=*/0, + strict, flags, &checks, explain_p); + if (!explain_p) + pop_tinst_level (); + if (!ok) + goto fail; + + /* Now that we have bindings for all of the template arguments, + ensure that the arguments deduced for the template template + parameters have compatible template parameter lists. We cannot + check this property before we have deduced all template + arguments, because the template parameter types of a template + template parameter might depend on prior template parameters + deduced after the template template parameter. The following + ill-formed example illustrates this issue: + + template<typename T, template<T> class C> void f(C<5>, T); + + template<int N> struct X {}; + + void g() { + f(X<5>(), 5l); // error: template argument deduction fails + } + + The template parameter list of 'C' depends on the template type + parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to + 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the + time that we deduce 'C'. */ + if (!template_template_parm_bindings_ok_p + (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs)) + { + unify_inconsistent_template_template_parameters (explain_p); + goto fail; + } + + /* All is well so far. Now, check: + + [temp.deduct] + + When all template arguments have been deduced, all uses of + template parameters in nondeduced contexts are replaced with + the corresponding deduced argument values. If the + substitution results in an invalid type, as described above, + type deduction fails. */ + TREE_VALUE (tinst) = targs; + if (!push_tinst_level (tinst)) + { + excessive_deduction_depth = true; + goto fail; + } + + /* Also collect access checks from the instantiation. */ + reopen_deferring_access_checks (checks); + + decl = instantiate_template (fn, targs, complain); + + checks = get_deferred_access_checks (); + pop_deferring_access_checks (); + + pop_tinst_level (); + + if (decl == error_mark_node) + goto fail; + + /* Now perform any access checks encountered during substitution. */ + push_access_scope (decl); + ok = perform_access_checks (checks, complain); + pop_access_scope (decl); + if (!ok) + goto fail; + + /* If we're looking for an exact match, check that what we got + is indeed an exact match. It might not be if some template + parameters are used in non-deduced contexts. But don't check + for an exact match if we have dependent template arguments; + in that case we're doing partial ordering, and we already know + that we have two candidates that will provide the actual type. */ + if (strict == DEDUCE_EXACT && !any_dependent_template_arguments_p (targs)) + { + tree substed = TREE_TYPE (decl); + unsigned int i; + + tree sarg + = skip_artificial_parms_for (decl, TYPE_ARG_TYPES (substed)); + if (return_type) + sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg); + for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg)) + if (!same_type_p (args[i], TREE_VALUE (sarg))) + { + unify_type_mismatch (explain_p, args[i], + TREE_VALUE (sarg)); + goto fail; + } + } + + r = decl; + + fail: + --deduction_depth; + if (excessive_deduction_depth) + { + if (deduction_depth == 0) + /* Reset once we're all the way out. */ + excessive_deduction_depth = false; + } + + /* We can't free this if a pending_template entry or last_error_tinst_level + is pointing at it. */ + if (last_pending_template == old_last_pend + && last_error_tinst_level == old_error_tinst) + ggc_free (tinst); + + return r; +} + +/* Adjust types before performing type deduction, as described in + [temp.deduct.call] and [temp.deduct.conv]. The rules in these two + sections are symmetric. PARM is the type of a function parameter + or the return type of the conversion function. ARG is the type of + the argument passed to the call, or the type of the value + initialized with the result of the conversion function. + ARG_EXPR is the original argument expression, which may be null. */ + +static int +maybe_adjust_types_for_deduction (unification_kind_t strict, + tree* parm, + tree* arg, + tree arg_expr) +{ + int result = 0; + + switch (strict) + { + case DEDUCE_CALL: + break; + + case DEDUCE_CONV: + { + /* Swap PARM and ARG throughout the remainder of this + function; the handling is precisely symmetric since PARM + will initialize ARG rather than vice versa. */ + tree* temp = parm; + parm = arg; + arg = temp; + break; + } + + case DEDUCE_EXACT: + /* Core issue #873: Do the DR606 thing (see below) for these cases, + too, but here handle it by stripping the reference from PARM + rather than by adding it to ARG. */ + if (TREE_CODE (*parm) == REFERENCE_TYPE + && TYPE_REF_IS_RVALUE (*parm) + && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM + && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED + && TREE_CODE (*arg) == REFERENCE_TYPE + && !TYPE_REF_IS_RVALUE (*arg)) + *parm = TREE_TYPE (*parm); + /* Nothing else to do in this case. */ + return 0; + + default: + gcc_unreachable (); + } + + if (TREE_CODE (*parm) != REFERENCE_TYPE) + { + /* [temp.deduct.call] + + If P is not a reference type: + + --If A is an array type, the pointer type produced by the + array-to-pointer standard conversion (_conv.array_) is + used in place of A for type deduction; otherwise, + + --If A is a function type, the pointer type produced by + the function-to-pointer standard conversion + (_conv.func_) is used in place of A for type deduction; + otherwise, + + --If A is a cv-qualified type, the top level + cv-qualifiers of A's type are ignored for type + deduction. */ + if (TREE_CODE (*arg) == ARRAY_TYPE) + *arg = build_pointer_type (TREE_TYPE (*arg)); + else if (TREE_CODE (*arg) == FUNCTION_TYPE) + *arg = build_pointer_type (*arg); + else + *arg = TYPE_MAIN_VARIANT (*arg); + } + + /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is + of the form T&&, where T is a template parameter, and the argument + is an lvalue, T is deduced as A& */ + if (TREE_CODE (*parm) == REFERENCE_TYPE + && TYPE_REF_IS_RVALUE (*parm) + && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM + && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED + && (arg_expr ? real_lvalue_p (arg_expr) + /* try_one_overload doesn't provide an arg_expr, but + functions are always lvalues. */ + : TREE_CODE (*arg) == FUNCTION_TYPE)) + *arg = build_reference_type (*arg); + + /* [temp.deduct.call] + + If P is a cv-qualified type, the top level cv-qualifiers + of P's type are ignored for type deduction. If P is a + reference type, the type referred to by P is used for + type deduction. */ + *parm = TYPE_MAIN_VARIANT (*parm); + if (TREE_CODE (*parm) == REFERENCE_TYPE) + { + *parm = TREE_TYPE (*parm); + result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL; + } + + /* DR 322. For conversion deduction, remove a reference type on parm + too (which has been swapped into ARG). */ + if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE) + *arg = TREE_TYPE (*arg); + + return result; +} + +/* Subroutine of unify_one_argument. PARM is a function parameter of a + template which does contain any deducible template parameters; check if + ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in + unify_one_argument. */ + +static int +check_non_deducible_conversion (tree parm, tree arg, int strict, + int flags, bool explain_p) +{ + tree type; + + if (!TYPE_P (arg)) + type = TREE_TYPE (arg); + else + type = arg; + + if (same_type_p (parm, type)) + return unify_success (explain_p); + + if (strict == DEDUCE_CONV) + { + if (can_convert_arg (type, parm, NULL_TREE, flags, + explain_p ? tf_warning_or_error : tf_none)) + return unify_success (explain_p); + } + else if (strict != DEDUCE_EXACT) + { + if (can_convert_arg (parm, type, + TYPE_P (arg) ? NULL_TREE : arg, + flags, explain_p ? tf_warning_or_error : tf_none)) + return unify_success (explain_p); + } + + if (strict == DEDUCE_EXACT) + return unify_type_mismatch (explain_p, parm, arg); + else + return unify_arg_conversion (explain_p, parm, type, arg); +} + +static bool uses_deducible_template_parms (tree type); + +/* Returns true iff the expression EXPR is one from which a template + argument can be deduced. In other words, if it's an undecorated + use of a template non-type parameter. */ + +static bool +deducible_expression (tree expr) +{ + return (TREE_CODE (expr) == TEMPLATE_PARM_INDEX); +} + +/* Returns true iff the array domain DOMAIN uses a template parameter in a + deducible way; that is, if it has a max value of <PARM> - 1. */ + +static bool +deducible_array_bound (tree domain) +{ + if (domain == NULL_TREE) + return false; + + tree max = TYPE_MAX_VALUE (domain); + if (TREE_CODE (max) != MINUS_EXPR) + return false; + + return deducible_expression (TREE_OPERAND (max, 0)); +} + +/* Returns true iff the template arguments ARGS use a template parameter + in a deducible way. */ + +static bool +deducible_template_args (tree args) +{ + for (int i = 0; i < TREE_VEC_LENGTH (args); ++i) + { + bool deducible; + tree elt = TREE_VEC_ELT (args, i); + if (ARGUMENT_PACK_P (elt)) + deducible = deducible_template_args (ARGUMENT_PACK_ARGS (elt)); + else + { + if (PACK_EXPANSION_P (elt)) + elt = PACK_EXPANSION_PATTERN (elt); + if (TREE_CODE (elt) == TEMPLATE_TEMPLATE_PARM) + deducible = true; + else if (TYPE_P (elt)) + deducible = uses_deducible_template_parms (elt); + else + deducible = deducible_expression (elt); + } + if (deducible) + return true; + } + return false; +} + +/* Returns true iff TYPE contains any deducible references to template + parameters, as per 14.8.2.5. */ + +static bool +uses_deducible_template_parms (tree type) +{ + if (PACK_EXPANSION_P (type)) + type = PACK_EXPANSION_PATTERN (type); + + /* T + cv-list T + TT<T> + TT<i> + TT<> */ + if (TREE_CODE (type) == TEMPLATE_TYPE_PARM + || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM) + return true; + + /* T* + T& + T&& */ + if (POINTER_TYPE_P (type)) + return uses_deducible_template_parms (TREE_TYPE (type)); + + /* T[integer-constant ] + type [i] */ + if (TREE_CODE (type) == ARRAY_TYPE) + return (uses_deducible_template_parms (TREE_TYPE (type)) + || deducible_array_bound (TYPE_DOMAIN (type))); + + /* T type ::* + type T::* + T T::* + T (type ::*)() + type (T::*)() + type (type ::*)(T) + type (T::*)(T) + T (type ::*)(T) + T (T::*)() + T (T::*)(T) */ + if (TYPE_PTRMEM_P (type)) + return (uses_deducible_template_parms (TYPE_PTRMEM_CLASS_TYPE (type)) + || (uses_deducible_template_parms + (TYPE_PTRMEM_POINTED_TO_TYPE (type)))); + + /* template-name <T> (where template-name refers to a class template) + template-name <i> (where template-name refers to a class template) */ + if (CLASS_TYPE_P (type) + && CLASSTYPE_TEMPLATE_INFO (type) + && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type))) + return deducible_template_args (INNERMOST_TEMPLATE_ARGS + (CLASSTYPE_TI_ARGS (type))); + + /* type (T) + T() + T(T) */ + if (TREE_CODE (type) == FUNCTION_TYPE + || TREE_CODE (type) == METHOD_TYPE) + { + if (uses_deducible_template_parms (TREE_TYPE (type))) + return true; + tree parm = TYPE_ARG_TYPES (type); + if (TREE_CODE (type) == METHOD_TYPE) + parm = TREE_CHAIN (parm); + for (; parm; parm = TREE_CHAIN (parm)) + if (uses_deducible_template_parms (TREE_VALUE (parm))) + return true; + } + + return false; +} + +/* Subroutine of type_unification_real and unify_pack_expansion to + handle unification of a single P/A pair. Parameters are as + for those functions. */ + +static int +unify_one_argument (tree tparms, tree targs, tree parm, tree arg, + int subr, unification_kind_t strict, int flags, + bool explain_p) +{ + tree arg_expr = NULL_TREE; + int arg_strict; + + if (arg == error_mark_node || parm == error_mark_node) + return unify_invalid (explain_p); + if (arg == unknown_type_node) + /* We can't deduce anything from this, but we might get all the + template args from other function args. */ + return unify_success (explain_p); + + /* Implicit conversions (Clause 4) will be performed on a function + argument to convert it to the type of the corresponding function + parameter if the parameter type contains no template-parameters that + participate in template argument deduction. */ + if (TYPE_P (parm) && !uses_template_parms (parm)) + /* For function parameters that contain no template-parameters at all, + we have historically checked for convertibility in order to shortcut + consideration of this candidate. */ + return check_non_deducible_conversion (parm, arg, strict, flags, + explain_p); + else if (strict == DEDUCE_CALL + && TYPE_P (parm) && !uses_deducible_template_parms (parm)) + /* For function parameters with only non-deducible template parameters, + just return. */ + return unify_success (explain_p); + + switch (strict) + { + case DEDUCE_CALL: + arg_strict = (UNIFY_ALLOW_OUTER_LEVEL + | UNIFY_ALLOW_MORE_CV_QUAL + | UNIFY_ALLOW_DERIVED); + break; + + case DEDUCE_CONV: + arg_strict = UNIFY_ALLOW_LESS_CV_QUAL; + break; + + case DEDUCE_EXACT: + arg_strict = UNIFY_ALLOW_NONE; + break; + + default: + gcc_unreachable (); + } + + /* We only do these transformations if this is the top-level + parameter_type_list in a call or declaration matching; in other + situations (nested function declarators, template argument lists) we + won't be comparing a type to an expression, and we don't do any type + adjustments. */ + if (!subr) + { + if (!TYPE_P (arg)) + { + gcc_assert (TREE_TYPE (arg) != NULL_TREE); + if (type_unknown_p (arg)) + { + /* [temp.deduct.type] A template-argument can be + deduced from a pointer to function or pointer + to member function argument if the set of + overloaded functions does not contain function + templates and at most one of a set of + overloaded functions provides a unique + match. */ + + if (resolve_overloaded_unification + (tparms, targs, parm, arg, strict, + arg_strict, explain_p)) + return unify_success (explain_p); + return unify_overload_resolution_failure (explain_p, arg); + } + + arg_expr = arg; + arg = unlowered_expr_type (arg); + if (arg == error_mark_node) + return unify_invalid (explain_p); + } + + arg_strict |= + maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr); + } + else + gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL) + == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)); + + /* For deduction from an init-list we need the actual list. */ + if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr)) + arg = arg_expr; + return unify (tparms, targs, parm, arg, arg_strict, explain_p); +} + +/* Most parms like fn_type_unification. + + If SUBR is 1, we're being called recursively (to unify the + arguments of a function or method parameter of a function + template). + + CHECKS is a pointer to a vector of access checks encountered while + substituting default template arguments. */ + +static int +type_unification_real (tree tparms, + tree targs, + tree xparms, + const tree *xargs, + unsigned int xnargs, + int subr, + unification_kind_t strict, + int flags, + vec<deferred_access_check, va_gc> **checks, + bool explain_p) +{ + tree parm, arg; + int i; + int ntparms = TREE_VEC_LENGTH (tparms); + int saw_undeduced = 0; + tree parms; + const tree *args; + unsigned int nargs; + unsigned int ia; + + gcc_assert (TREE_CODE (tparms) == TREE_VEC); + gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST); + gcc_assert (ntparms > 0); + + /* Reset the number of non-defaulted template arguments contained + in TARGS. */ + NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE; + + again: + parms = xparms; + args = xargs; + nargs = xnargs; + + ia = 0; + while (parms && parms != void_list_node + && ia < nargs) + { + parm = TREE_VALUE (parms); + + if (TREE_CODE (parm) == TYPE_PACK_EXPANSION + && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node)) + /* For a function parameter pack that occurs at the end of the + parameter-declaration-list, the type A of each remaining + argument of the call is compared with the type P of the + declarator-id of the function parameter pack. */ + break; + + parms = TREE_CHAIN (parms); + + if (TREE_CODE (parm) == TYPE_PACK_EXPANSION) + /* For a function parameter pack that does not occur at the + end of the parameter-declaration-list, the type of the + parameter pack is a non-deduced context. */ + continue; + + arg = args[ia]; + ++ia; + + if (unify_one_argument (tparms, targs, parm, arg, subr, strict, + flags, explain_p)) + return 1; + } + + if (parms + && parms != void_list_node + && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION) + { + /* Unify the remaining arguments with the pack expansion type. */ + tree argvec; + tree parmvec = make_tree_vec (1); + + /* Allocate a TREE_VEC and copy in all of the arguments */ + argvec = make_tree_vec (nargs - ia); + for (i = 0; ia < nargs; ++ia, ++i) + TREE_VEC_ELT (argvec, i) = args[ia]; + + /* Copy the parameter into parmvec. */ + TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms); + if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict, + /*subr=*/subr, explain_p)) + return 1; + + /* Advance to the end of the list of parameters. */ + parms = TREE_CHAIN (parms); + } + + /* Fail if we've reached the end of the parm list, and more args + are present, and the parm list isn't variadic. */ + if (ia < nargs && parms == void_list_node) + return unify_too_many_arguments (explain_p, nargs, ia); + /* Fail if parms are left and they don't have default values. */ + if (parms && parms != void_list_node + && TREE_PURPOSE (parms) == NULL_TREE) + { + unsigned int count = nargs; + tree p = parms; + while (p && p != void_list_node) + { + count++; + p = TREE_CHAIN (p); + } + return unify_too_few_arguments (explain_p, ia, count); + } + + if (!subr) + { + tsubst_flags_t complain = (explain_p + ? tf_warning_or_error + : tf_none); + + for (i = 0; i < ntparms; i++) + { + tree targ = TREE_VEC_ELT (targs, i); + tree tparm = TREE_VEC_ELT (tparms, i); + + /* Clear the "incomplete" flags on all argument packs now so that + substituting them into later default arguments works. */ + if (targ && ARGUMENT_PACK_P (targ)) + { + ARGUMENT_PACK_INCOMPLETE_P (targ) = 0; + ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE; + } + + if (targ || tparm == error_mark_node) + continue; + tparm = TREE_VALUE (tparm); + + /* If this is an undeduced nontype parameter that depends on + a type parameter, try another pass; its type may have been + deduced from a later argument than the one from which + this parameter can be deduced. */ + if (TREE_CODE (tparm) == PARM_DECL + && uses_template_parms (TREE_TYPE (tparm)) + && !saw_undeduced++) + goto again; + + /* Core issue #226 (C++0x) [temp.deduct]: + + If a template argument has not been deduced, its + default template argument, if any, is used. + + When we are in C++98 mode, TREE_PURPOSE will either + be NULL_TREE or ERROR_MARK_NODE, so we do not need + to explicitly check cxx_dialect here. */ + if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i))) + { + tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i)); + tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i)); + reopen_deferring_access_checks (*checks); + location_t save_loc = input_location; + if (DECL_P (parm)) + input_location = DECL_SOURCE_LOCATION (parm); + arg = tsubst_template_arg (arg, targs, complain, NULL_TREE); + arg = convert_template_argument (parm, arg, targs, complain, + i, NULL_TREE); + input_location = save_loc; + *checks = get_deferred_access_checks (); + pop_deferring_access_checks (); + if (arg == error_mark_node) + return 1; + else + { + TREE_VEC_ELT (targs, i) = arg; + /* The position of the first default template argument, + is also the number of non-defaulted arguments in TARGS. + Record that. */ + if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs)) + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i); + continue; + } + } + + /* If the type parameter is a parameter pack, then it will + be deduced to an empty parameter pack. */ + if (template_parameter_pack_p (tparm)) + { + tree arg; + + if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX) + { + arg = make_node (NONTYPE_ARGUMENT_PACK); + TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm)); + TREE_CONSTANT (arg) = 1; + } + else + arg = cxx_make_type (TYPE_ARGUMENT_PACK); + + SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0)); + + TREE_VEC_ELT (targs, i) = arg; + continue; + } + + return unify_parameter_deduction_failure (explain_p, tparm); + } + } +#ifdef ENABLE_CHECKING + if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs)) + SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs)); +#endif + + return unify_success (explain_p); +} + +/* Subroutine of type_unification_real. Args are like the variables + at the call site. ARG is an overloaded function (or template-id); + we try deducing template args from each of the overloads, and if + only one succeeds, we go with that. Modifies TARGS and returns + true on success. */ + +static bool +resolve_overloaded_unification (tree tparms, + tree targs, + tree parm, + tree arg, + unification_kind_t strict, + int sub_strict, + bool explain_p) +{ + tree tempargs = copy_node (targs); + int good = 0; + tree goodfn = NULL_TREE; + bool addr_p; + + if (TREE_CODE (arg) == ADDR_EXPR) + { + arg = TREE_OPERAND (arg, 0); + addr_p = true; + } + else + addr_p = false; + + if (TREE_CODE (arg) == COMPONENT_REF) + /* Handle `&x' where `x' is some static or non-static member + function name. */ + arg = TREE_OPERAND (arg, 1); + + if (TREE_CODE (arg) == OFFSET_REF) + arg = TREE_OPERAND (arg, 1); + + /* Strip baselink information. */ + if (BASELINK_P (arg)) + arg = BASELINK_FUNCTIONS (arg); + + if (TREE_CODE (arg) == TEMPLATE_ID_EXPR) + { + /* If we got some explicit template args, we need to plug them into + the affected templates before we try to unify, in case the + explicit args will completely resolve the templates in question. */ + + int ok = 0; + tree expl_subargs = TREE_OPERAND (arg, 1); + arg = TREE_OPERAND (arg, 0); + + for (; arg; arg = OVL_NEXT (arg)) + { + tree fn = OVL_CURRENT (arg); + tree subargs, elem; + + if (TREE_CODE (fn) != TEMPLATE_DECL) + continue; + + subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn), + expl_subargs, NULL_TREE, tf_none, + /*require_all_args=*/true, + /*use_default_args=*/true); + if (subargs != error_mark_node + && !any_dependent_template_arguments_p (subargs)) + { + elem = TREE_TYPE (instantiate_template (fn, subargs, tf_none)); + if (try_one_overload (tparms, targs, tempargs, parm, + elem, strict, sub_strict, addr_p, explain_p) + && (!goodfn || !same_type_p (goodfn, elem))) + { + goodfn = elem; + ++good; + } + } + else if (subargs) + ++ok; + } + /* If no templates (or more than one) are fully resolved by the + explicit arguments, this template-id is a non-deduced context; it + could still be OK if we deduce all template arguments for the + enclosing call through other arguments. */ + if (good != 1) + good = ok; + } + else if (TREE_CODE (arg) != OVERLOAD + && TREE_CODE (arg) != FUNCTION_DECL) + /* If ARG is, for example, "(0, &f)" then its type will be unknown + -- but the deduction does not succeed because the expression is + not just the function on its own. */ + return false; + else + for (; arg; arg = OVL_NEXT (arg)) + if (try_one_overload (tparms, targs, tempargs, parm, + TREE_TYPE (OVL_CURRENT (arg)), + strict, sub_strict, addr_p, explain_p) + && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg)))) + { + goodfn = OVL_CURRENT (arg); + ++good; + } + + /* [temp.deduct.type] A template-argument can be deduced from a pointer + to function or pointer to member function argument if the set of + overloaded functions does not contain function templates and at most + one of a set of overloaded functions provides a unique match. + + So if we found multiple possibilities, we return success but don't + deduce anything. */ + + if (good == 1) + { + int i = TREE_VEC_LENGTH (targs); + for (; i--; ) + if (TREE_VEC_ELT (tempargs, i)) + TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i); + } + if (good) + return true; + + return false; +} + +/* Core DR 115: In contexts where deduction is done and fails, or in + contexts where deduction is not done, if a template argument list is + specified and it, along with any default template arguments, identifies + a single function template specialization, then the template-id is an + lvalue for the function template specialization. */ + +tree +resolve_nondeduced_context (tree orig_expr) +{ + tree expr, offset, baselink; + bool addr; + + if (!type_unknown_p (orig_expr)) + return orig_expr; + + expr = orig_expr; + addr = false; + offset = NULL_TREE; + baselink = NULL_TREE; + + if (TREE_CODE (expr) == ADDR_EXPR) + { + expr = TREE_OPERAND (expr, 0); + addr = true; + } + if (TREE_CODE (expr) == OFFSET_REF) + { + offset = expr; + expr = TREE_OPERAND (expr, 1); + } + if (BASELINK_P (expr)) + { + baselink = expr; + expr = BASELINK_FUNCTIONS (expr); + } + + if (TREE_CODE (expr) == TEMPLATE_ID_EXPR) + { + int good = 0; + tree goodfn = NULL_TREE; + + /* If we got some explicit template args, we need to plug them into + the affected templates before we try to unify, in case the + explicit args will completely resolve the templates in question. */ + + tree expl_subargs = TREE_OPERAND (expr, 1); + tree arg = TREE_OPERAND (expr, 0); + tree badfn = NULL_TREE; + tree badargs = NULL_TREE; + + for (; arg; arg = OVL_NEXT (arg)) + { + tree fn = OVL_CURRENT (arg); + tree subargs, elem; + + if (TREE_CODE (fn) != TEMPLATE_DECL) + continue; + + subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn), + expl_subargs, NULL_TREE, tf_none, + /*require_all_args=*/true, + /*use_default_args=*/true); + if (subargs != error_mark_node + && !any_dependent_template_arguments_p (subargs)) + { + elem = instantiate_template (fn, subargs, tf_none); + if (elem == error_mark_node) + { + badfn = fn; + badargs = subargs; + } + else if (elem && (!goodfn || !decls_match (goodfn, elem))) + { + goodfn = elem; + ++good; + } + } + } + if (good == 1) + { + mark_used (goodfn); + expr = goodfn; + if (baselink) + expr = build_baselink (BASELINK_BINFO (baselink), + BASELINK_ACCESS_BINFO (baselink), + expr, BASELINK_OPTYPE (baselink)); + if (offset) + { + tree base + = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0))); + expr = build_offset_ref (base, expr, addr, tf_warning_or_error); + } + if (addr) + expr = cp_build_addr_expr (expr, tf_warning_or_error); + return expr; + } + else if (good == 0 && badargs) + /* There were no good options and at least one bad one, so let the + user know what the problem is. */ + instantiate_template (badfn, badargs, tf_warning_or_error); + } + return orig_expr; +} + +/* Subroutine of resolve_overloaded_unification; does deduction for a single + overload. Fills TARGS with any deduced arguments, or error_mark_node if + different overloads deduce different arguments for a given parm. + ADDR_P is true if the expression for which deduction is being + performed was of the form "& fn" rather than simply "fn". + + Returns 1 on success. */ + +static int +try_one_overload (tree tparms, + tree orig_targs, + tree targs, + tree parm, + tree arg, + unification_kind_t strict, + int sub_strict, + bool addr_p, + bool explain_p) +{ + int nargs; + tree tempargs; + int i; + + if (arg == error_mark_node) + return 0; + + /* [temp.deduct.type] A template-argument can be deduced from a pointer + to function or pointer to member function argument if the set of + overloaded functions does not contain function templates and at most + one of a set of overloaded functions provides a unique match. + + So if this is a template, just return success. */ + + if (uses_template_parms (arg)) + return 1; + + if (TREE_CODE (arg) == METHOD_TYPE) + arg = build_ptrmemfunc_type (build_pointer_type (arg)); + else if (addr_p) + arg = build_pointer_type (arg); + + sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL); + + /* We don't copy orig_targs for this because if we have already deduced + some template args from previous args, unify would complain when we + try to deduce a template parameter for the same argument, even though + there isn't really a conflict. */ + nargs = TREE_VEC_LENGTH (targs); + tempargs = make_tree_vec (nargs); + + if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p)) + return 0; + + /* First make sure we didn't deduce anything that conflicts with + explicitly specified args. */ + for (i = nargs; i--; ) + { + tree elt = TREE_VEC_ELT (tempargs, i); + tree oldelt = TREE_VEC_ELT (orig_targs, i); + + if (!elt) + /*NOP*/; + else if (uses_template_parms (elt)) + /* Since we're unifying against ourselves, we will fill in + template args used in the function parm list with our own + template parms. Discard them. */ + TREE_VEC_ELT (tempargs, i) = NULL_TREE; + else if (oldelt && !template_args_equal (oldelt, elt)) + return 0; + } + + for (i = nargs; i--; ) + { + tree elt = TREE_VEC_ELT (tempargs, i); + + if (elt) + TREE_VEC_ELT (targs, i) = elt; + } + + return 1; +} + +/* PARM is a template class (perhaps with unbound template + parameters). ARG is a fully instantiated type. If ARG can be + bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and + TARGS are as for unify. */ + +static tree +try_class_unification (tree tparms, tree targs, tree parm, tree arg, + bool explain_p) +{ + tree copy_of_targs; + + if (!CLASSTYPE_TEMPLATE_INFO (arg) + || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg)) + != most_general_template (CLASSTYPE_TI_TEMPLATE (parm)))) + return NULL_TREE; + + /* We need to make a new template argument vector for the call to + unify. If we used TARGS, we'd clutter it up with the result of + the attempted unification, even if this class didn't work out. + We also don't want to commit ourselves to all the unifications + we've already done, since unification is supposed to be done on + an argument-by-argument basis. In other words, consider the + following pathological case: + + template <int I, int J, int K> + struct S {}; + + template <int I, int J> + struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {}; + + template <int I, int J, int K> + void f(S<I, J, K>, S<I, I, I>); + + void g() { + S<0, 0, 0> s0; + S<0, 1, 2> s2; + + f(s0, s2); + } + + Now, by the time we consider the unification involving `s2', we + already know that we must have `f<0, 0, 0>'. But, even though + `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid + because there are two ways to unify base classes of S<0, 1, 2> + with S<I, I, I>. If we kept the already deduced knowledge, we + would reject the possibility I=1. */ + copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs)); + + /* If unification failed, we're done. */ + if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm), + CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p)) + return NULL_TREE; + + return arg; +} + +/* Given a template type PARM and a class type ARG, find the unique + base type in ARG that is an instance of PARM. We do not examine + ARG itself; only its base-classes. If there is not exactly one + appropriate base class, return NULL_TREE. PARM may be the type of + a partial specialization, as well as a plain template type. Used + by unify. */ + +static enum template_base_result +get_template_base (tree tparms, tree targs, tree parm, tree arg, + bool explain_p, tree *result) +{ + tree rval = NULL_TREE; + tree binfo; + + gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg))); + + binfo = TYPE_BINFO (complete_type (arg)); + if (!binfo) + { + /* The type could not be completed. */ + *result = NULL_TREE; + return tbr_incomplete_type; + } + + /* Walk in inheritance graph order. The search order is not + important, and this avoids multiple walks of virtual bases. */ + for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo)) + { + tree r = try_class_unification (tparms, targs, parm, + BINFO_TYPE (binfo), explain_p); + + if (r) + { + /* If there is more than one satisfactory baseclass, then: + + [temp.deduct.call] + + If they yield more than one possible deduced A, the type + deduction fails. + + applies. */ + if (rval && !same_type_p (r, rval)) + { + *result = NULL_TREE; + return tbr_ambiguous_baseclass; + } + + rval = r; + } + } + + *result = rval; + return tbr_success; +} + +/* Returns the level of DECL, which declares a template parameter. */ + +static int +template_decl_level (tree decl) +{ + switch (TREE_CODE (decl)) + { + case TYPE_DECL: + case TEMPLATE_DECL: + return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl)); + + case PARM_DECL: + return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl)); + + default: + gcc_unreachable (); + } + return 0; +} + +/* Decide whether ARG can be unified with PARM, considering only the + cv-qualifiers of each type, given STRICT as documented for unify. + Returns nonzero iff the unification is OK on that basis. */ + +static int +check_cv_quals_for_unify (int strict, tree arg, tree parm) +{ + int arg_quals = cp_type_quals (arg); + int parm_quals = cp_type_quals (parm); + + if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM + && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL)) + { + /* Although a CVR qualifier is ignored when being applied to a + substituted template parameter ([8.3.2]/1 for example), that + does not allow us to unify "const T" with "int&" because both + types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type]. + It is ok when we're allowing additional CV qualifiers + at the outer level [14.8.2.1]/3,1st bullet. */ + if ((TREE_CODE (arg) == REFERENCE_TYPE + || TREE_CODE (arg) == FUNCTION_TYPE + || TREE_CODE (arg) == METHOD_TYPE) + && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE))) + return 0; + + if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM) + && (parm_quals & TYPE_QUAL_RESTRICT)) + return 0; + } + + if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL)) + && (arg_quals & parm_quals) != parm_quals) + return 0; + + if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL)) + && (parm_quals & arg_quals) != arg_quals) + return 0; + + return 1; +} + +/* Determines the LEVEL and INDEX for the template parameter PARM. */ +void +template_parm_level_and_index (tree parm, int* level, int* index) +{ + if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM + || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM + || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) + { + *index = TEMPLATE_TYPE_IDX (parm); + *level = TEMPLATE_TYPE_LEVEL (parm); + } + else + { + *index = TEMPLATE_PARM_IDX (parm); + *level = TEMPLATE_PARM_LEVEL (parm); + } +} + +#define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \ + do { \ + if (unify (TP, TA, P, A, S, EP)) \ + return 1; \ + } while (0); + +/* Unifies the remaining arguments in PACKED_ARGS with the pack + expansion at the end of PACKED_PARMS. Returns 0 if the type + deduction succeeds, 1 otherwise. STRICT is the same as in + unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function + call argument list. We'll need to adjust the arguments to make them + types. SUBR tells us if this is from a recursive call to + type_unification_real, or for comparing two template argument + lists. */ + +static int +unify_pack_expansion (tree tparms, tree targs, tree packed_parms, + tree packed_args, unification_kind_t strict, + bool subr, bool explain_p) +{ + tree parm + = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1); + tree pattern = PACK_EXPANSION_PATTERN (parm); + tree pack, packs = NULL_TREE; + int i, start = TREE_VEC_LENGTH (packed_parms) - 1; + + packed_args = expand_template_argument_pack (packed_args); + + int len = TREE_VEC_LENGTH (packed_args); + + /* Determine the parameter packs we will be deducing from the + pattern, and record their current deductions. */ + for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm); + pack; pack = TREE_CHAIN (pack)) + { + tree parm_pack = TREE_VALUE (pack); + int idx, level; + + /* Determine the index and level of this parameter pack. */ + template_parm_level_and_index (parm_pack, &level, &idx); + + /* Keep track of the parameter packs and their corresponding + argument packs. */ + packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs); + TREE_TYPE (packs) = make_tree_vec (len - start); + } + + /* Loop through all of the arguments that have not yet been + unified and unify each with the pattern. */ + for (i = start; i < len; i++) + { + tree parm; + bool any_explicit = false; + tree arg = TREE_VEC_ELT (packed_args, i); + + /* For each parameter pack, set its TMPL_ARG to either NULL_TREE + or the element of its argument pack at the current index if + this argument was explicitly specified. */ + for (pack = packs; pack; pack = TREE_CHAIN (pack)) + { + int idx, level; + tree arg, pargs; + template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx); + + arg = NULL_TREE; + if (TREE_VALUE (pack) + && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack))) + && (i - start < TREE_VEC_LENGTH (pargs))) + { + any_explicit = true; + arg = TREE_VEC_ELT (pargs, i - start); + } + TMPL_ARG (targs, level, idx) = arg; + } + + /* If we had explicit template arguments, substitute them into the + pattern before deduction. */ + if (any_explicit) + { + /* Some arguments might still be unspecified or dependent. */ + bool dependent; + ++processing_template_decl; + dependent = any_dependent_template_arguments_p (targs); + if (!dependent) + --processing_template_decl; + parm = tsubst (pattern, targs, + explain_p ? tf_warning_or_error : tf_none, + NULL_TREE); + if (dependent) + --processing_template_decl; + if (parm == error_mark_node) + return 1; + } + else + parm = pattern; + + /* Unify the pattern with the current argument. */ + if (unify_one_argument (tparms, targs, parm, arg, subr, strict, + LOOKUP_IMPLICIT, explain_p)) + return 1; + + /* For each parameter pack, collect the deduced value. */ + for (pack = packs; pack; pack = TREE_CHAIN (pack)) + { + int idx, level; + template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx); + + TREE_VEC_ELT (TREE_TYPE (pack), i - start) = + TMPL_ARG (targs, level, idx); + } + } + + /* Verify that the results of unification with the parameter packs + produce results consistent with what we've seen before, and make + the deduced argument packs available. */ + for (pack = packs; pack; pack = TREE_CHAIN (pack)) + { + tree old_pack = TREE_VALUE (pack); + tree new_args = TREE_TYPE (pack); + int i, len = TREE_VEC_LENGTH (new_args); + int idx, level; + bool nondeduced_p = false; + + /* By default keep the original deduced argument pack. + If necessary, more specific code is going to update the + resulting deduced argument later down in this function. */ + template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx); + TMPL_ARG (targs, level, idx) = old_pack; + + /* If NEW_ARGS contains any NULL_TREE entries, we didn't + actually deduce anything. */ + for (i = 0; i < len && !nondeduced_p; ++i) + if (TREE_VEC_ELT (new_args, i) == NULL_TREE) + nondeduced_p = true; + if (nondeduced_p) + continue; + + if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack)) + { + /* If we had fewer function args than explicit template args, + just use the explicits. */ + tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack); + int explicit_len = TREE_VEC_LENGTH (explicit_args); + if (len < explicit_len) + new_args = explicit_args; + } + + if (!old_pack) + { + tree result; + /* Build the deduced *_ARGUMENT_PACK. */ + if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX) + { + result = make_node (NONTYPE_ARGUMENT_PACK); + TREE_TYPE (result) = + TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack))); + TREE_CONSTANT (result) = 1; + } + else + result = cxx_make_type (TYPE_ARGUMENT_PACK); + + SET_ARGUMENT_PACK_ARGS (result, new_args); + + /* Note the deduced argument packs for this parameter + pack. */ + TMPL_ARG (targs, level, idx) = result; + } + else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack) + && (ARGUMENT_PACK_ARGS (old_pack) + == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack))) + { + /* We only had the explicitly-provided arguments before, but + now we have a complete set of arguments. */ + tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack); + + SET_ARGUMENT_PACK_ARGS (old_pack, new_args); + ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1; + ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args; + } + else + { + tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE; + tree old_args = ARGUMENT_PACK_ARGS (old_pack); + + if (!comp_template_args_with_info (old_args, new_args, + &bad_old_arg, &bad_new_arg)) + /* Inconsistent unification of this parameter pack. */ + return unify_parameter_pack_inconsistent (explain_p, + bad_old_arg, + bad_new_arg); + } + } + + return unify_success (explain_p); +} + +/* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are + INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other + parameters and return value are as for unify. */ + +static int +unify_array_domain (tree tparms, tree targs, + tree parm_dom, tree arg_dom, + bool explain_p) +{ + tree parm_max; + tree arg_max; + bool parm_cst; + bool arg_cst; + + /* Our representation of array types uses "N - 1" as the + TYPE_MAX_VALUE for an array with "N" elements, if "N" is + not an integer constant. We cannot unify arbitrarily + complex expressions, so we eliminate the MINUS_EXPRs + here. */ + parm_max = TYPE_MAX_VALUE (parm_dom); + parm_cst = TREE_CODE (parm_max) == INTEGER_CST; + if (!parm_cst) + { + gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR); + parm_max = TREE_OPERAND (parm_max, 0); + } + arg_max = TYPE_MAX_VALUE (arg_dom); + arg_cst = TREE_CODE (arg_max) == INTEGER_CST; + if (!arg_cst) + { + /* The ARG_MAX may not be a simple MINUS_EXPR, if we are + trying to unify the type of a variable with the type + of a template parameter. For example: + + template <unsigned int N> + void f (char (&) [N]); + int g(); + void h(int i) { + char a[g(i)]; + f(a); + } + + Here, the type of the ARG will be "int [g(i)]", and + may be a SAVE_EXPR, etc. */ + if (TREE_CODE (arg_max) != MINUS_EXPR) + return unify_vla_arg (explain_p, arg_dom); + arg_max = TREE_OPERAND (arg_max, 0); + } + + /* If only one of the bounds used a MINUS_EXPR, compensate + by adding one to the other bound. */ + if (parm_cst && !arg_cst) + parm_max = fold_build2_loc (input_location, PLUS_EXPR, + integer_type_node, + parm_max, + integer_one_node); + else if (arg_cst && !parm_cst) + arg_max = fold_build2_loc (input_location, PLUS_EXPR, + integer_type_node, + arg_max, + integer_one_node); + + return unify (tparms, targs, parm_max, arg_max, + UNIFY_ALLOW_INTEGER, explain_p); +} + +/* Deduce the value of template parameters. TPARMS is the (innermost) + set of template parameters to a template. TARGS is the bindings + for those template parameters, as determined thus far; TARGS may + include template arguments for outer levels of template parameters + as well. PARM is a parameter to a template function, or a + subcomponent of that parameter; ARG is the corresponding argument. + This function attempts to match PARM with ARG in a manner + consistent with the existing assignments in TARGS. If more values + are deduced, then TARGS is updated. + + Returns 0 if the type deduction succeeds, 1 otherwise. The + parameter STRICT is a bitwise or of the following flags: + + UNIFY_ALLOW_NONE: + Require an exact match between PARM and ARG. + UNIFY_ALLOW_MORE_CV_QUAL: + Allow the deduced ARG to be more cv-qualified (by qualification + conversion) than ARG. + UNIFY_ALLOW_LESS_CV_QUAL: + Allow the deduced ARG to be less cv-qualified than ARG. + UNIFY_ALLOW_DERIVED: + Allow the deduced ARG to be a template base class of ARG, + or a pointer to a template base class of the type pointed to by + ARG. + UNIFY_ALLOW_INTEGER: + Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX + case for more information. + UNIFY_ALLOW_OUTER_LEVEL: + This is the outermost level of a deduction. Used to determine validity + of qualification conversions. A valid qualification conversion must + have const qualified pointers leading up to the inner type which + requires additional CV quals, except at the outer level, where const + is not required [conv.qual]. It would be normal to set this flag in + addition to setting UNIFY_ALLOW_MORE_CV_QUAL. + UNIFY_ALLOW_OUTER_MORE_CV_QUAL: + This is the outermost level of a deduction, and PARM can be more CV + qualified at this point. + UNIFY_ALLOW_OUTER_LESS_CV_QUAL: + This is the outermost level of a deduction, and PARM can be less CV + qualified at this point. */ + +static int +unify (tree tparms, tree targs, tree parm, tree arg, int strict, + bool explain_p) +{ + int idx; + tree targ; + tree tparm; + int strict_in = strict; + + /* I don't think this will do the right thing with respect to types. + But the only case I've seen it in so far has been array bounds, where + signedness is the only information lost, and I think that will be + okay. */ + while (TREE_CODE (parm) == NOP_EXPR) + parm = TREE_OPERAND (parm, 0); + + if (arg == error_mark_node) + return unify_invalid (explain_p); + if (arg == unknown_type_node + || arg == init_list_type_node) + /* We can't deduce anything from this, but we might get all the + template args from other function args. */ + return unify_success (explain_p); + + /* If PARM uses template parameters, then we can't bail out here, + even if ARG == PARM, since we won't record unifications for the + template parameters. We might need them if we're trying to + figure out which of two things is more specialized. */ + if (arg == parm && !uses_template_parms (parm)) + return unify_success (explain_p); + + /* Handle init lists early, so the rest of the function can assume + we're dealing with a type. */ + if (BRACE_ENCLOSED_INITIALIZER_P (arg)) + { + tree elt, elttype; + unsigned i; + tree orig_parm = parm; + + /* Replace T with std::initializer_list<T> for deduction. */ + if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM + && flag_deduce_init_list) + parm = listify (parm); + + if (!is_std_init_list (parm) + && TREE_CODE (parm) != ARRAY_TYPE) + /* We can only deduce from an initializer list argument if the + parameter is std::initializer_list or an array; otherwise this + is a non-deduced context. */ + return unify_success (explain_p); + + if (TREE_CODE (parm) == ARRAY_TYPE) + elttype = TREE_TYPE (parm); + else + elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0); + + FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt) + { + int elt_strict = strict; + + if (elt == error_mark_node) + return unify_invalid (explain_p); + + if (!BRACE_ENCLOSED_INITIALIZER_P (elt)) + { + tree type = TREE_TYPE (elt); + /* It should only be possible to get here for a call. */ + gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL); + elt_strict |= maybe_adjust_types_for_deduction + (DEDUCE_CALL, &elttype, &type, elt); + elt = type; + } + + RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict, + explain_p); + } + + if (TREE_CODE (parm) == ARRAY_TYPE + && deducible_array_bound (TYPE_DOMAIN (parm))) + { + /* Also deduce from the length of the initializer list. */ + tree max = size_int (CONSTRUCTOR_NELTS (arg)); + tree idx = compute_array_index_type (NULL_TREE, max, tf_none); + if (idx == error_mark_node) + return unify_invalid (explain_p); + return unify_array_domain (tparms, targs, TYPE_DOMAIN (parm), + idx, explain_p); + } + + /* If the std::initializer_list<T> deduction worked, replace the + deduced A with std::initializer_list<A>. */ + if (orig_parm != parm) + { + idx = TEMPLATE_TYPE_IDX (orig_parm); + targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx); + targ = listify (targ); + TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ; + } + return unify_success (explain_p); + } + + /* Immediately reject some pairs that won't unify because of + cv-qualification mismatches. */ + if (TREE_CODE (arg) == TREE_CODE (parm) + && TYPE_P (arg) + /* It is the elements of the array which hold the cv quals of an array + type, and the elements might be template type parms. We'll check + when we recurse. */ + && TREE_CODE (arg) != ARRAY_TYPE + /* We check the cv-qualifiers when unifying with template type + parameters below. We want to allow ARG `const T' to unify with + PARM `T' for example, when computing which of two templates + is more specialized, for example. */ + && TREE_CODE (arg) != TEMPLATE_TYPE_PARM + && !check_cv_quals_for_unify (strict_in, arg, parm)) + return unify_cv_qual_mismatch (explain_p, parm, arg); + + if (!(strict & UNIFY_ALLOW_OUTER_LEVEL) + && TYPE_P (parm) && !CP_TYPE_CONST_P (parm)) + strict &= ~UNIFY_ALLOW_MORE_CV_QUAL; + strict &= ~UNIFY_ALLOW_OUTER_LEVEL; + strict &= ~UNIFY_ALLOW_DERIVED; + strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL; + strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL; + + switch (TREE_CODE (parm)) + { + case TYPENAME_TYPE: + case SCOPE_REF: + case UNBOUND_CLASS_TEMPLATE: + /* In a type which contains a nested-name-specifier, template + argument values cannot be deduced for template parameters used + within the nested-name-specifier. */ + return unify_success (explain_p); + + case TEMPLATE_TYPE_PARM: + case TEMPLATE_TEMPLATE_PARM: + case BOUND_TEMPLATE_TEMPLATE_PARM: + tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0)); + if (tparm == error_mark_node) + return unify_invalid (explain_p); + + if (TEMPLATE_TYPE_LEVEL (parm) + != template_decl_level (tparm)) + /* The PARM is not one we're trying to unify. Just check + to see if it matches ARG. */ + { + if (TREE_CODE (arg) == TREE_CODE (parm) + && (is_auto (parm) ? is_auto (arg) + : same_type_p (parm, arg))) + return unify_success (explain_p); + else + return unify_type_mismatch (explain_p, parm, arg); + } + idx = TEMPLATE_TYPE_IDX (parm); + targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx); + tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx)); + if (tparm == error_mark_node) + return unify_invalid (explain_p); + + /* Check for mixed types and values. */ + if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM + && TREE_CODE (tparm) != TYPE_DECL) + || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM + && TREE_CODE (tparm) != TEMPLATE_DECL)) + gcc_unreachable (); + + if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) + { + /* ARG must be constructed from a template class or a template + template parameter. */ + if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM + && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg)) + return unify_template_deduction_failure (explain_p, parm, arg); + { + tree parmvec = TYPE_TI_ARGS (parm); + /* An alias template name is never deduced. */ + if (TYPE_ALIAS_P (arg)) + arg = strip_typedefs (arg); + tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg)); + tree full_argvec = add_to_template_args (targs, argvec); + tree parm_parms + = DECL_INNERMOST_TEMPLATE_PARMS + (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm)); + int i, len; + int parm_variadic_p = 0; + + /* The resolution to DR150 makes clear that default + arguments for an N-argument may not be used to bind T + to a template template parameter with fewer than N + parameters. It is not safe to permit the binding of + default arguments as an extension, as that may change + the meaning of a conforming program. Consider: + + struct Dense { static const unsigned int dim = 1; }; + + template <template <typename> class View, + typename Block> + void operator+(float, View<Block> const&); + + template <typename Block, + unsigned int Dim = Block::dim> + struct Lvalue_proxy { operator float() const; }; + + void + test_1d (void) { + Lvalue_proxy<Dense> p; + float b; + b + p; + } + + Here, if Lvalue_proxy is permitted to bind to View, then + the global operator+ will be used; if they are not, the + Lvalue_proxy will be converted to float. */ + if (coerce_template_parms (parm_parms, + full_argvec, + TYPE_TI_TEMPLATE (parm), + (explain_p + ? tf_warning_or_error + : tf_none), + /*require_all_args=*/true, + /*use_default_args=*/false) + == error_mark_node) + return 1; + + /* Deduce arguments T, i from TT<T> or TT<i>. + We check each element of PARMVEC and ARGVEC individually + rather than the whole TREE_VEC since they can have + different number of elements. */ + + parmvec = expand_template_argument_pack (parmvec); + argvec = expand_template_argument_pack (argvec); + + len = TREE_VEC_LENGTH (parmvec); + + /* Check if the parameters end in a pack, making them + variadic. */ + if (len > 0 + && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1))) + parm_variadic_p = 1; + + for (i = 0; i < len - parm_variadic_p; ++i) + /* If the template argument list of P contains a pack + expansion that is not the last template argument, the + entire template argument list is a non-deduced + context. */ + if (PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, i))) + return unify_success (explain_p); + + if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p) + return unify_too_few_arguments (explain_p, + TREE_VEC_LENGTH (argvec), len); + + for (i = 0; i < len - parm_variadic_p; ++i) + { + RECUR_AND_CHECK_FAILURE (tparms, targs, + TREE_VEC_ELT (parmvec, i), + TREE_VEC_ELT (argvec, i), + UNIFY_ALLOW_NONE, explain_p); + } + + if (parm_variadic_p + && unify_pack_expansion (tparms, targs, + parmvec, argvec, + DEDUCE_EXACT, + /*subr=*/true, explain_p)) + return 1; + } + arg = TYPE_TI_TEMPLATE (arg); + + /* Fall through to deduce template name. */ + } + + if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM + || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM) + { + /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */ + + /* Simple cases: Value already set, does match or doesn't. */ + if (targ != NULL_TREE && template_args_equal (targ, arg)) + return unify_success (explain_p); + else if (targ) + return unify_inconsistency (explain_p, parm, targ, arg); + } + else + { + /* If PARM is `const T' and ARG is only `int', we don't have + a match unless we are allowing additional qualification. + If ARG is `const int' and PARM is just `T' that's OK; + that binds `const int' to `T'. */ + if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL, + arg, parm)) + return unify_cv_qual_mismatch (explain_p, parm, arg); + + /* Consider the case where ARG is `const volatile int' and + PARM is `const T'. Then, T should be `volatile int'. */ + arg = cp_build_qualified_type_real + (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none); + if (arg == error_mark_node) + return unify_invalid (explain_p); + + /* Simple cases: Value already set, does match or doesn't. */ + if (targ != NULL_TREE && same_type_p (targ, arg)) + return unify_success (explain_p); + else if (targ) + return unify_inconsistency (explain_p, parm, targ, arg); + + /* Make sure that ARG is not a variable-sized array. (Note + that were talking about variable-sized arrays (like + `int[n]'), rather than arrays of unknown size (like + `int[]').) We'll get very confused by such a type since + the bound of the array is not constant, and therefore + not mangleable. Besides, such types are not allowed in + ISO C++, so we can do as we please here. We do allow + them for 'auto' deduction, since that isn't ABI-exposed. */ + if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE)) + return unify_vla_arg (explain_p, arg); + + /* Strip typedefs as in convert_template_argument. */ + arg = canonicalize_type_argument (arg, tf_none); + } + + /* If ARG is a parameter pack or an expansion, we cannot unify + against it unless PARM is also a parameter pack. */ + if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg)) + && !template_parameter_pack_p (parm)) + return unify_parameter_pack_mismatch (explain_p, parm, arg); + + /* If the argument deduction results is a METHOD_TYPE, + then there is a problem. + METHOD_TYPE doesn't map to any real C++ type the result of + the deduction can not be of that type. */ + if (TREE_CODE (arg) == METHOD_TYPE) + return unify_method_type_error (explain_p, arg); + + TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg; + return unify_success (explain_p); + + case TEMPLATE_PARM_INDEX: + tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0)); + if (tparm == error_mark_node) + return unify_invalid (explain_p); + + if (TEMPLATE_PARM_LEVEL (parm) + != template_decl_level (tparm)) + { + /* The PARM is not one we're trying to unify. Just check + to see if it matches ARG. */ + int result = !(TREE_CODE (arg) == TREE_CODE (parm) + && cp_tree_equal (parm, arg)); + if (result) + unify_expression_unequal (explain_p, parm, arg); + return result; + } + + idx = TEMPLATE_PARM_IDX (parm); + targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx); + + if (targ) + { + int x = !cp_tree_equal (targ, arg); + if (x) + unify_inconsistency (explain_p, parm, targ, arg); + return x; + } + + /* [temp.deduct.type] If, in the declaration of a function template + with a non-type template-parameter, the non-type + template-parameter is used in an expression in the function + parameter-list and, if the corresponding template-argument is + deduced, the template-argument type shall match the type of the + template-parameter exactly, except that a template-argument + deduced from an array bound may be of any integral type. + The non-type parameter might use already deduced type parameters. */ + tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE); + if (!TREE_TYPE (arg)) + /* Template-parameter dependent expression. Just accept it for now. + It will later be processed in convert_template_argument. */ + ; + else if (same_type_p (TREE_TYPE (arg), tparm)) + /* OK */; + else if ((strict & UNIFY_ALLOW_INTEGER) + && CP_INTEGRAL_TYPE_P (tparm)) + /* Convert the ARG to the type of PARM; the deduced non-type + template argument must exactly match the types of the + corresponding parameter. */ + arg = fold (build_nop (tparm, arg)); + else if (uses_template_parms (tparm)) + /* We haven't deduced the type of this parameter yet. Try again + later. */ + return unify_success (explain_p); + else + return unify_type_mismatch (explain_p, tparm, TREE_TYPE (arg)); + + /* If ARG is a parameter pack or an expansion, we cannot unify + against it unless PARM is also a parameter pack. */ + if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg)) + && !TEMPLATE_PARM_PARAMETER_PACK (parm)) + return unify_parameter_pack_mismatch (explain_p, parm, arg); + + arg = strip_typedefs_expr (arg); + TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg; + return unify_success (explain_p); + + case PTRMEM_CST: + { + /* A pointer-to-member constant can be unified only with + another constant. */ + if (TREE_CODE (arg) != PTRMEM_CST) + return unify_ptrmem_cst_mismatch (explain_p, parm, arg); + + /* Just unify the class member. It would be useless (and possibly + wrong, depending on the strict flags) to unify also + PTRMEM_CST_CLASS, because we want to be sure that both parm and + arg refer to the same variable, even if through different + classes. For instance: + + struct A { int x; }; + struct B : A { }; + + Unification of &A::x and &B::x must succeed. */ + return unify (tparms, targs, PTRMEM_CST_MEMBER (parm), + PTRMEM_CST_MEMBER (arg), strict, explain_p); + } + + case POINTER_TYPE: + { + if (!TYPE_PTR_P (arg)) + return unify_type_mismatch (explain_p, parm, arg); + + /* [temp.deduct.call] + + A can be another pointer or pointer to member type that can + be converted to the deduced A via a qualification + conversion (_conv.qual_). + + We pass down STRICT here rather than UNIFY_ALLOW_NONE. + This will allow for additional cv-qualification of the + pointed-to types if appropriate. */ + + if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE) + /* The derived-to-base conversion only persists through one + level of pointers. */ + strict |= (strict_in & UNIFY_ALLOW_DERIVED); + + return unify (tparms, targs, TREE_TYPE (parm), + TREE_TYPE (arg), strict, explain_p); + } + + case REFERENCE_TYPE: + if (TREE_CODE (arg) != REFERENCE_TYPE) + return unify_type_mismatch (explain_p, parm, arg); + return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg), + strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p); + + case ARRAY_TYPE: + if (TREE_CODE (arg) != ARRAY_TYPE) + return unify_type_mismatch (explain_p, parm, arg); + if ((TYPE_DOMAIN (parm) == NULL_TREE) + != (TYPE_DOMAIN (arg) == NULL_TREE)) + return unify_type_mismatch (explain_p, parm, arg); + RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg), + strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p); + if (TYPE_DOMAIN (parm) != NULL_TREE) + return unify_array_domain (tparms, targs, TYPE_DOMAIN (parm), + TYPE_DOMAIN (arg), explain_p); + return unify_success (explain_p); + + case REAL_TYPE: + case COMPLEX_TYPE: + case VECTOR_TYPE: + case INTEGER_TYPE: + case BOOLEAN_TYPE: + case ENUMERAL_TYPE: + case VOID_TYPE: + case NULLPTR_TYPE: + if (TREE_CODE (arg) != TREE_CODE (parm)) + return unify_type_mismatch (explain_p, parm, arg); + + /* We have already checked cv-qualification at the top of the + function. */ + if (!same_type_ignoring_top_level_qualifiers_p (arg, parm)) + return unify_type_mismatch (explain_p, parm, arg); + + /* As far as unification is concerned, this wins. Later checks + will invalidate it if necessary. */ + return unify_success (explain_p); + + /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */ + /* Type INTEGER_CST can come from ordinary constant template args. */ + case INTEGER_CST: + while (TREE_CODE (arg) == NOP_EXPR) + arg = TREE_OPERAND (arg, 0); + + if (TREE_CODE (arg) != INTEGER_CST) + return unify_template_argument_mismatch (explain_p, parm, arg); + return (tree_int_cst_equal (parm, arg) + ? unify_success (explain_p) + : unify_template_argument_mismatch (explain_p, parm, arg)); + + case TREE_VEC: + { + int i, len, argslen; + int parm_variadic_p = 0; + + if (TREE_CODE (arg) != TREE_VEC) + return unify_template_argument_mismatch (explain_p, parm, arg); + + len = TREE_VEC_LENGTH (parm); + argslen = TREE_VEC_LENGTH (arg); + + /* Check for pack expansions in the parameters. */ + for (i = 0; i < len; ++i) + { + if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i))) + { + if (i == len - 1) + /* We can unify against something with a trailing + parameter pack. */ + parm_variadic_p = 1; + else + /* [temp.deduct.type]/9: If the template argument list of + P contains a pack expansion that is not the last + template argument, the entire template argument list + is a non-deduced context. */ + return unify_success (explain_p); + } + } + + /* If we don't have enough arguments to satisfy the parameters + (not counting the pack expression at the end), or we have + too many arguments for a parameter list that doesn't end in + a pack expression, we can't unify. */ + if (parm_variadic_p + ? argslen < len - parm_variadic_p + : argslen != len) + return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len); + + /* Unify all of the parameters that precede the (optional) + pack expression. */ + for (i = 0; i < len - parm_variadic_p; ++i) + { + RECUR_AND_CHECK_FAILURE (tparms, targs, + TREE_VEC_ELT (parm, i), + TREE_VEC_ELT (arg, i), + UNIFY_ALLOW_NONE, explain_p); + } + if (parm_variadic_p) + return unify_pack_expansion (tparms, targs, parm, arg, + DEDUCE_EXACT, + /*subr=*/true, explain_p); + return unify_success (explain_p); + } + + case RECORD_TYPE: + case UNION_TYPE: + if (TREE_CODE (arg) != TREE_CODE (parm)) + return unify_type_mismatch (explain_p, parm, arg); + + if (TYPE_PTRMEMFUNC_P (parm)) + { + if (!TYPE_PTRMEMFUNC_P (arg)) + return unify_type_mismatch (explain_p, parm, arg); + + return unify (tparms, targs, + TYPE_PTRMEMFUNC_FN_TYPE (parm), + TYPE_PTRMEMFUNC_FN_TYPE (arg), + strict, explain_p); + } + + if (CLASSTYPE_TEMPLATE_INFO (parm)) + { + tree t = NULL_TREE; + + if (strict_in & UNIFY_ALLOW_DERIVED) + { + /* First, we try to unify the PARM and ARG directly. */ + t = try_class_unification (tparms, targs, + parm, arg, explain_p); + + if (!t) + { + /* Fallback to the special case allowed in + [temp.deduct.call]: + + If P is a class, and P has the form + template-id, then A can be a derived class of + the deduced A. Likewise, if P is a pointer to + a class of the form template-id, A can be a + pointer to a derived class pointed to by the + deduced A. */ + enum template_base_result r; + r = get_template_base (tparms, targs, parm, arg, + explain_p, &t); + + if (!t) + return unify_no_common_base (explain_p, r, parm, arg); + } + } + else if (CLASSTYPE_TEMPLATE_INFO (arg) + && (CLASSTYPE_TI_TEMPLATE (parm) + == CLASSTYPE_TI_TEMPLATE (arg))) + /* Perhaps PARM is something like S<U> and ARG is S<int>. + Then, we should unify `int' and `U'. */ + t = arg; + else + /* There's no chance of unification succeeding. */ + return unify_type_mismatch (explain_p, parm, arg); + + return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm), + CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p); + } + else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg)) + return unify_type_mismatch (explain_p, parm, arg); + return unify_success (explain_p); + + case METHOD_TYPE: + case FUNCTION_TYPE: + { + unsigned int nargs; + tree *args; + tree a; + unsigned int i; + + if (TREE_CODE (arg) != TREE_CODE (parm)) + return unify_type_mismatch (explain_p, parm, arg); + + /* CV qualifications for methods can never be deduced, they must + match exactly. We need to check them explicitly here, + because type_unification_real treats them as any other + cv-qualified parameter. */ + if (TREE_CODE (parm) == METHOD_TYPE + && (!check_cv_quals_for_unify + (UNIFY_ALLOW_NONE, + class_of_this_parm (arg), + class_of_this_parm (parm)))) + return unify_cv_qual_mismatch (explain_p, parm, arg); + + RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm), + TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p); + + nargs = list_length (TYPE_ARG_TYPES (arg)); + args = XALLOCAVEC (tree, nargs); + for (a = TYPE_ARG_TYPES (arg), i = 0; + a != NULL_TREE && a != void_list_node; + a = TREE_CHAIN (a), ++i) + args[i] = TREE_VALUE (a); + nargs = i; + + return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm), + args, nargs, 1, DEDUCE_EXACT, + LOOKUP_NORMAL, NULL, explain_p); + } + + case OFFSET_TYPE: + /* Unify a pointer to member with a pointer to member function, which + deduces the type of the member as a function type. */ + if (TYPE_PTRMEMFUNC_P (arg)) + { + /* Check top-level cv qualifiers */ + if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm)) + return unify_cv_qual_mismatch (explain_p, parm, arg); + + RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm), + TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), + UNIFY_ALLOW_NONE, explain_p); + + /* Determine the type of the function we are unifying against. */ + tree fntype = static_fn_type (arg); + + return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p); + } + + if (TREE_CODE (arg) != OFFSET_TYPE) + return unify_type_mismatch (explain_p, parm, arg); + RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm), + TYPE_OFFSET_BASETYPE (arg), + UNIFY_ALLOW_NONE, explain_p); + return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg), + strict, explain_p); + + case CONST_DECL: + if (DECL_TEMPLATE_PARM_P (parm)) + return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p); + if (arg != integral_constant_value (parm)) + return unify_template_argument_mismatch (explain_p, parm, arg); + return unify_success (explain_p); + + case FIELD_DECL: + case TEMPLATE_DECL: + /* Matched cases are handled by the ARG == PARM test above. */ + return unify_template_argument_mismatch (explain_p, parm, arg); + + case VAR_DECL: + /* A non-type template parameter that is a variable should be a + an integral constant, in which case, it whould have been + folded into its (constant) value. So we should not be getting + a variable here. */ + gcc_unreachable (); + + case TYPE_ARGUMENT_PACK: + case NONTYPE_ARGUMENT_PACK: + return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm), + ARGUMENT_PACK_ARGS (arg), strict, explain_p); + + case TYPEOF_TYPE: + case DECLTYPE_TYPE: + case UNDERLYING_TYPE: + /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE, + or UNDERLYING_TYPE nodes. */ + return unify_success (explain_p); + + case ERROR_MARK: + /* Unification fails if we hit an error node. */ + return unify_invalid (explain_p); + + case INDIRECT_REF: + if (REFERENCE_REF_P (parm)) + return unify (tparms, targs, TREE_OPERAND (parm, 0), arg, + strict, explain_p); + /* FALLTHRU */ + + default: + /* An unresolved overload is a nondeduced context. */ + if (is_overloaded_fn (parm) || type_unknown_p (parm)) + return unify_success (explain_p); + gcc_assert (EXPR_P (parm)); + + /* We must be looking at an expression. This can happen with + something like: + + template <int I> + void foo(S<I>, S<I + 2>); + + This is a "nondeduced context": + + [deduct.type] + + The nondeduced contexts are: + + --A type that is a template-id in which one or more of + the template-arguments is an expression that references + a template-parameter. + + In these cases, we assume deduction succeeded, but don't + actually infer any unifications. */ + + if (!uses_template_parms (parm) + && !template_args_equal (parm, arg)) + return unify_expression_unequal (explain_p, parm, arg); + else + return unify_success (explain_p); + } +} +#undef RECUR_AND_CHECK_FAILURE + +/* Note that DECL can be defined in this translation unit, if + required. */ + +static void +mark_definable (tree decl) +{ + tree clone; + DECL_NOT_REALLY_EXTERN (decl) = 1; + FOR_EACH_CLONE (clone, decl) + DECL_NOT_REALLY_EXTERN (clone) = 1; +} + +/* Called if RESULT is explicitly instantiated, or is a member of an + explicitly instantiated class. */ + +void +mark_decl_instantiated (tree result, int extern_p) +{ + SET_DECL_EXPLICIT_INSTANTIATION (result); + + /* If this entity has already been written out, it's too late to + make any modifications. */ + if (TREE_ASM_WRITTEN (result)) + return; + + /* For anonymous namespace we don't need to do anything. */ + if (decl_anon_ns_mem_p (result)) + { + gcc_assert (!TREE_PUBLIC (result)); + return; + } + + if (TREE_CODE (result) != FUNCTION_DECL) + /* The TREE_PUBLIC flag for function declarations will have been + set correctly by tsubst. */ + TREE_PUBLIC (result) = 1; + + /* This might have been set by an earlier implicit instantiation. */ + DECL_COMDAT (result) = 0; + + if (extern_p) + DECL_NOT_REALLY_EXTERN (result) = 0; + else + { + mark_definable (result); + mark_needed (result); + /* Always make artificials weak. */ + if (DECL_ARTIFICIAL (result) && flag_weak) + comdat_linkage (result); + /* For WIN32 we also want to put explicit instantiations in + linkonce sections. */ + else if (TREE_PUBLIC (result)) + maybe_make_one_only (result); + } + + /* If EXTERN_P, then this function will not be emitted -- unless + followed by an explicit instantiation, at which point its linkage + will be adjusted. If !EXTERN_P, then this function will be + emitted here. In neither circumstance do we want + import_export_decl to adjust the linkage. */ + DECL_INTERFACE_KNOWN (result) = 1; +} + +/* Subroutine of more_specialized_fn: check whether TARGS is missing any + important template arguments. If any are missing, we check whether + they're important by using error_mark_node for substituting into any + args that were used for partial ordering (the ones between ARGS and END) + and seeing if it bubbles up. */ + +static bool +check_undeduced_parms (tree targs, tree args, tree end) +{ + bool found = false; + int i; + for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i) + if (TREE_VEC_ELT (targs, i) == NULL_TREE) + { + found = true; + TREE_VEC_ELT (targs, i) = error_mark_node; + } + if (found) + { + tree substed = tsubst_arg_types (args, targs, end, tf_none, NULL_TREE); + if (substed == error_mark_node) + return true; + } + return false; +} + +/* Given two function templates PAT1 and PAT2, return: + + 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order]. + -1 if PAT2 is more specialized than PAT1. + 0 if neither is more specialized. + + LEN indicates the number of parameters we should consider + (defaulted parameters should not be considered). + + The 1998 std underspecified function template partial ordering, and + DR214 addresses the issue. We take pairs of arguments, one from + each of the templates, and deduce them against each other. One of + the templates will be more specialized if all the *other* + template's arguments deduce against its arguments and at least one + of its arguments *does* *not* deduce against the other template's + corresponding argument. Deduction is done as for class templates. + The arguments used in deduction have reference and top level cv + qualifiers removed. Iff both arguments were originally reference + types *and* deduction succeeds in both directions, an lvalue reference + wins against an rvalue reference and otherwise the template + with the more cv-qualified argument wins for that pairing (if + neither is more cv-qualified, they both are equal). Unlike regular + deduction, after all the arguments have been deduced in this way, + we do *not* verify the deduced template argument values can be + substituted into non-deduced contexts. + + The logic can be a bit confusing here, because we look at deduce1 and + targs1 to see if pat2 is at least as specialized, and vice versa; if we + can find template arguments for pat1 to make arg1 look like arg2, that + means that arg2 is at least as specialized as arg1. */ + +int +more_specialized_fn (tree pat1, tree pat2, int len) +{ + tree decl1 = DECL_TEMPLATE_RESULT (pat1); + tree decl2 = DECL_TEMPLATE_RESULT (pat2); + tree targs1 = make_tree_vec (DECL_NTPARMS (pat1)); + tree targs2 = make_tree_vec (DECL_NTPARMS (pat2)); + tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1); + tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2); + tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1)); + tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2)); + tree origs1, origs2; + bool lose1 = false; + bool lose2 = false; + + /* Remove the this parameter from non-static member functions. If + one is a non-static member function and the other is not a static + member function, remove the first parameter from that function + also. This situation occurs for operator functions where we + locate both a member function (with this pointer) and non-member + operator (with explicit first operand). */ + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1)) + { + len--; /* LEN is the number of significant arguments for DECL1 */ + args1 = TREE_CHAIN (args1); + if (!DECL_STATIC_FUNCTION_P (decl2)) + args2 = TREE_CHAIN (args2); + } + else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2)) + { + args2 = TREE_CHAIN (args2); + if (!DECL_STATIC_FUNCTION_P (decl1)) + { + len--; + args1 = TREE_CHAIN (args1); + } + } + + /* If only one is a conversion operator, they are unordered. */ + if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2)) + return 0; + + /* Consider the return type for a conversion function */ + if (DECL_CONV_FN_P (decl1)) + { + args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1); + args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2); + len++; + } + + processing_template_decl++; + + origs1 = args1; + origs2 = args2; + + while (len-- + /* Stop when an ellipsis is seen. */ + && args1 != NULL_TREE && args2 != NULL_TREE) + { + tree arg1 = TREE_VALUE (args1); + tree arg2 = TREE_VALUE (args2); + int deduce1, deduce2; + int quals1 = -1; + int quals2 = -1; + int ref1 = 0; + int ref2 = 0; + + if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION + && TREE_CODE (arg2) == TYPE_PACK_EXPANSION) + { + /* When both arguments are pack expansions, we need only + unify the patterns themselves. */ + arg1 = PACK_EXPANSION_PATTERN (arg1); + arg2 = PACK_EXPANSION_PATTERN (arg2); + + /* This is the last comparison we need to do. */ + len = 0; + } + + if (TREE_CODE (arg1) == REFERENCE_TYPE) + { + ref1 = TYPE_REF_IS_RVALUE (arg1) + 1; + arg1 = TREE_TYPE (arg1); + quals1 = cp_type_quals (arg1); + } + + if (TREE_CODE (arg2) == REFERENCE_TYPE) + { + ref2 = TYPE_REF_IS_RVALUE (arg2) + 1; + arg2 = TREE_TYPE (arg2); + quals2 = cp_type_quals (arg2); + } + + arg1 = TYPE_MAIN_VARIANT (arg1); + arg2 = TYPE_MAIN_VARIANT (arg2); + + if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION) + { + int i, len2 = list_length (args2); + tree parmvec = make_tree_vec (1); + tree argvec = make_tree_vec (len2); + tree ta = args2; + + /* Setup the parameter vector, which contains only ARG1. */ + TREE_VEC_ELT (parmvec, 0) = arg1; + + /* Setup the argument vector, which contains the remaining + arguments. */ + for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta)) + TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta); + + deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec, + argvec, DEDUCE_EXACT, + /*subr=*/true, /*explain_p=*/false) + == 0); + + /* We cannot deduce in the other direction, because ARG1 is + a pack expansion but ARG2 is not. */ + deduce2 = 0; + } + else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION) + { + int i, len1 = list_length (args1); + tree parmvec = make_tree_vec (1); + tree argvec = make_tree_vec (len1); + tree ta = args1; + + /* Setup the parameter vector, which contains only ARG1. */ + TREE_VEC_ELT (parmvec, 0) = arg2; + + /* Setup the argument vector, which contains the remaining + arguments. */ + for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta)) + TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta); + + deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec, + argvec, DEDUCE_EXACT, + /*subr=*/true, /*explain_p=*/false) + == 0); + + /* We cannot deduce in the other direction, because ARG2 is + a pack expansion but ARG1 is not.*/ + deduce1 = 0; + } + + else + { + /* The normal case, where neither argument is a pack + expansion. */ + deduce1 = (unify (tparms1, targs1, arg1, arg2, + UNIFY_ALLOW_NONE, /*explain_p=*/false) + == 0); + deduce2 = (unify (tparms2, targs2, arg2, arg1, + UNIFY_ALLOW_NONE, /*explain_p=*/false) + == 0); + } + + /* If we couldn't deduce arguments for tparms1 to make arg1 match + arg2, then arg2 is not as specialized as arg1. */ + if (!deduce1) + lose2 = true; + if (!deduce2) + lose1 = true; + + /* "If, for a given type, deduction succeeds in both directions + (i.e., the types are identical after the transformations above) + and both P and A were reference types (before being replaced with + the type referred to above): + - if the type from the argument template was an lvalue reference and + the type from the parameter template was not, the argument type is + considered to be more specialized than the other; otherwise, + - if the type from the argument template is more cv-qualified + than the type from the parameter template (as described above), + the argument type is considered to be more specialized than the other; + otherwise, + - neither type is more specialized than the other." */ + + if (deduce1 && deduce2) + { + if (ref1 && ref2 && ref1 != ref2) + { + if (ref1 > ref2) + lose1 = true; + else + lose2 = true; + } + else if (quals1 != quals2 && quals1 >= 0 && quals2 >= 0) + { + if ((quals1 & quals2) == quals2) + lose2 = true; + if ((quals1 & quals2) == quals1) + lose1 = true; + } + } + + if (lose1 && lose2) + /* We've failed to deduce something in either direction. + These must be unordered. */ + break; + + if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION + || TREE_CODE (arg2) == TYPE_PACK_EXPANSION) + /* We have already processed all of the arguments in our + handing of the pack expansion type. */ + len = 0; + + args1 = TREE_CHAIN (args1); + args2 = TREE_CHAIN (args2); + } + + /* "In most cases, all template parameters must have values in order for + deduction to succeed, but for partial ordering purposes a template + parameter may remain without a value provided it is not used in the + types being used for partial ordering." + + Thus, if we are missing any of the targs1 we need to substitute into + origs1, then pat2 is not as specialized as pat1. This can happen when + there is a nondeduced context. */ + if (!lose2 && check_undeduced_parms (targs1, origs1, args1)) + lose2 = true; + if (!lose1 && check_undeduced_parms (targs2, origs2, args2)) + lose1 = true; + + processing_template_decl--; + + /* All things being equal, if the next argument is a pack expansion + for one function but not for the other, prefer the + non-variadic function. FIXME this is bogus; see c++/41958. */ + if (lose1 == lose2 + && args1 && TREE_VALUE (args1) + && args2 && TREE_VALUE (args2)) + { + lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION; + lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION; + } + + if (lose1 == lose2) + return 0; + else if (!lose1) + return 1; + else + return -1; +} + +/* Determine which of two partial specializations of TMPL is more + specialized. + + PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding + to the first partial specialization. The TREE_VALUE is the + innermost set of template parameters for the partial + specialization. PAT2 is similar, but for the second template. + + Return 1 if the first partial specialization is more specialized; + -1 if the second is more specialized; 0 if neither is more + specialized. + + See [temp.class.order] for information about determining which of + two templates is more specialized. */ + +static int +more_specialized_class (tree tmpl, tree pat1, tree pat2) +{ + tree targs; + tree tmpl1, tmpl2; + int winner = 0; + bool any_deductions = false; + + tmpl1 = TREE_TYPE (pat1); + tmpl2 = TREE_TYPE (pat2); + + /* Just like what happens for functions, if we are ordering between + different class template specializations, we may encounter dependent + types in the arguments, and we need our dependency check functions + to behave correctly. */ + ++processing_template_decl; + targs = get_class_bindings (tmpl, TREE_VALUE (pat1), + CLASSTYPE_TI_ARGS (tmpl1), + CLASSTYPE_TI_ARGS (tmpl2)); + if (targs) + { + --winner; + any_deductions = true; + } + + targs = get_class_bindings (tmpl, TREE_VALUE (pat2), + CLASSTYPE_TI_ARGS (tmpl2), + CLASSTYPE_TI_ARGS (tmpl1)); + if (targs) + { + ++winner; + any_deductions = true; + } + --processing_template_decl; + + /* In the case of a tie where at least one of the class templates + has a parameter pack at the end, the template with the most + non-packed parameters wins. */ + if (winner == 0 + && any_deductions + && (template_args_variadic_p (TREE_PURPOSE (pat1)) + || template_args_variadic_p (TREE_PURPOSE (pat2)))) + { + tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1)); + tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2)); + int len1 = TREE_VEC_LENGTH (args1); + int len2 = TREE_VEC_LENGTH (args2); + + /* We don't count the pack expansion at the end. */ + if (template_args_variadic_p (TREE_PURPOSE (pat1))) + --len1; + if (template_args_variadic_p (TREE_PURPOSE (pat2))) + --len2; + + if (len1 > len2) + return 1; + else if (len1 < len2) + return -1; + } + + return winner; +} + +/* Return the template arguments that will produce the function signature + DECL from the function template FN, with the explicit template + arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must + also match. Return NULL_TREE if no satisfactory arguments could be + found. */ + +static tree +get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype) +{ + int ntparms = DECL_NTPARMS (fn); + tree targs = make_tree_vec (ntparms); + tree decl_type = TREE_TYPE (decl); + tree decl_arg_types; + tree *args; + unsigned int nargs, ix; + tree arg; + + gcc_assert (decl != DECL_TEMPLATE_RESULT (fn)); + + /* Never do unification on the 'this' parameter. */ + decl_arg_types = skip_artificial_parms_for (decl, + TYPE_ARG_TYPES (decl_type)); + + nargs = list_length (decl_arg_types); + args = XALLOCAVEC (tree, nargs); + for (arg = decl_arg_types, ix = 0; + arg != NULL_TREE && arg != void_list_node; + arg = TREE_CHAIN (arg), ++ix) + args[ix] = TREE_VALUE (arg); + + if (fn_type_unification (fn, explicit_args, targs, + args, ix, + (check_rettype || DECL_CONV_FN_P (fn) + ? TREE_TYPE (decl_type) : NULL_TREE), + DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false, + /*decltype*/false) + == error_mark_node) + return NULL_TREE; + + return targs; +} + +/* Return the innermost template arguments that, when applied to a partial + specialization of TMPL whose innermost template parameters are + TPARMS, and whose specialization arguments are SPEC_ARGS, yield the + ARGS. + + For example, suppose we have: + + template <class T, class U> struct S {}; + template <class T> struct S<T*, int> {}; + + Then, suppose we want to get `S<double*, int>'. The TPARMS will be + {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*, + int}. The resulting vector will be {double}, indicating that `T' + is bound to `double'. */ + +static tree +get_class_bindings (tree tmpl, tree tparms, tree spec_args, tree args) +{ + int i, ntparms = TREE_VEC_LENGTH (tparms); + tree deduced_args; + tree innermost_deduced_args; + + innermost_deduced_args = make_tree_vec (ntparms); + if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)) + { + deduced_args = copy_node (args); + SET_TMPL_ARGS_LEVEL (deduced_args, + TMPL_ARGS_DEPTH (deduced_args), + innermost_deduced_args); + } + else + deduced_args = innermost_deduced_args; + + if (unify (tparms, deduced_args, + INNERMOST_TEMPLATE_ARGS (spec_args), + INNERMOST_TEMPLATE_ARGS (args), + UNIFY_ALLOW_NONE, /*explain_p=*/false)) + return NULL_TREE; + + for (i = 0; i < ntparms; ++i) + if (! TREE_VEC_ELT (innermost_deduced_args, i)) + return NULL_TREE; + + /* Verify that nondeduced template arguments agree with the type + obtained from argument deduction. + + For example: + + struct A { typedef int X; }; + template <class T, class U> struct C {}; + template <class T> struct C<T, typename T::X> {}; + + Then with the instantiation `C<A, int>', we can deduce that + `T' is `A' but unify () does not check whether `typename T::X' + is `int'. */ + spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE); + spec_args = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl), + spec_args, tmpl, + tf_none, false, false); + if (spec_args == error_mark_node + /* We only need to check the innermost arguments; the other + arguments will always agree. */ + || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args), + INNERMOST_TEMPLATE_ARGS (args))) + return NULL_TREE; + + /* Now that we have bindings for all of the template arguments, + ensure that the arguments deduced for the template template + parameters have compatible template parameter lists. See the use + of template_template_parm_bindings_ok_p in fn_type_unification + for more information. */ + if (!template_template_parm_bindings_ok_p (tparms, deduced_args)) + return NULL_TREE; + + return deduced_args; +} + +/* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL. + Return the TREE_LIST node with the most specialized template, if + any. If there is no most specialized template, the error_mark_node + is returned. + + Note that this function does not look at, or modify, the + TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node + returned is one of the elements of INSTANTIATIONS, callers may + store information in the TREE_PURPOSE or TREE_TYPE of the nodes, + and retrieve it from the value returned. */ + +tree +most_specialized_instantiation (tree templates) +{ + tree fn, champ; + + ++processing_template_decl; + + champ = templates; + for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn)) + { + int fate = 0; + + if (get_bindings (TREE_VALUE (champ), + DECL_TEMPLATE_RESULT (TREE_VALUE (fn)), + NULL_TREE, /*check_ret=*/true)) + fate--; + + if (get_bindings (TREE_VALUE (fn), + DECL_TEMPLATE_RESULT (TREE_VALUE (champ)), + NULL_TREE, /*check_ret=*/true)) + fate++; + + if (fate == -1) + champ = fn; + else if (!fate) + { + /* Equally specialized, move to next function. If there + is no next function, nothing's most specialized. */ + fn = TREE_CHAIN (fn); + champ = fn; + if (!fn) + break; + } + } + + if (champ) + /* Now verify that champ is better than everything earlier in the + instantiation list. */ + for (fn = templates; fn != champ; fn = TREE_CHAIN (fn)) + if (get_bindings (TREE_VALUE (champ), + DECL_TEMPLATE_RESULT (TREE_VALUE (fn)), + NULL_TREE, /*check_ret=*/true) + || !get_bindings (TREE_VALUE (fn), + DECL_TEMPLATE_RESULT (TREE_VALUE (champ)), + NULL_TREE, /*check_ret=*/true)) + { + champ = NULL_TREE; + break; + } + + processing_template_decl--; + + if (!champ) + return error_mark_node; + + return champ; +} + +/* If DECL is a specialization of some template, return the most + general such template. Otherwise, returns NULL_TREE. + + For example, given: + + template <class T> struct S { template <class U> void f(U); }; + + if TMPL is `template <class U> void S<int>::f(U)' this will return + the full template. This function will not trace past partial + specializations, however. For example, given in addition: + + template <class T> struct S<T*> { template <class U> void f(U); }; + + if TMPL is `template <class U> void S<int*>::f(U)' this will return + `template <class T> template <class U> S<T*>::f(U)'. */ + +tree +most_general_template (tree decl) +{ + /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is + an immediate specialization. */ + if (TREE_CODE (decl) == FUNCTION_DECL) + { + if (DECL_TEMPLATE_INFO (decl)) { + decl = DECL_TI_TEMPLATE (decl); + + /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a + template friend. */ + if (TREE_CODE (decl) != TEMPLATE_DECL) + return NULL_TREE; + } else + return NULL_TREE; + } + + /* Look for more and more general templates. */ + while (DECL_TEMPLATE_INFO (decl)) + { + /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases. + (See cp-tree.h for details.) */ + if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL) + break; + + if (CLASS_TYPE_P (TREE_TYPE (decl)) + && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl))) + break; + + /* Stop if we run into an explicitly specialized class template. */ + if (!DECL_NAMESPACE_SCOPE_P (decl) + && DECL_CONTEXT (decl) + && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl))) + break; + + decl = DECL_TI_TEMPLATE (decl); + } + + return decl; +} + +/* Return the most specialized of the class template partial + specializations which can produce TYPE, a specialization of some class + template. The value returned is actually a TREE_LIST; the TREE_TYPE is + a _TYPE node corresponding to the partial specialization, while the + TREE_PURPOSE is the set of template arguments that must be + substituted into the TREE_TYPE in order to generate TYPE. + + If the choice of partial specialization is ambiguous, a diagnostic + is issued, and the error_mark_node is returned. If there are no + partial specializations matching TYPE, then NULL_TREE is + returned, indicating that the primary template should be used. */ + +static tree +most_specialized_class (tree type, tsubst_flags_t complain) +{ + tree list = NULL_TREE; + tree t; + tree champ; + int fate; + bool ambiguous_p; + tree outer_args = NULL_TREE; + + tree tmpl = CLASSTYPE_TI_TEMPLATE (type); + tree main_tmpl = most_general_template (tmpl); + tree args = CLASSTYPE_TI_ARGS (type); + + /* For determining which partial specialization to use, only the + innermost args are interesting. */ + if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)) + { + outer_args = strip_innermost_template_args (args, 1); + args = INNERMOST_TEMPLATE_ARGS (args); + } + + for (t = DECL_TEMPLATE_SPECIALIZATIONS (main_tmpl); t; t = TREE_CHAIN (t)) + { + tree partial_spec_args; + tree spec_args; + tree spec_tmpl = TREE_VALUE (t); + tree orig_parms = DECL_INNERMOST_TEMPLATE_PARMS (spec_tmpl); + + partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t)); + + ++processing_template_decl; + + if (outer_args) + { + /* Discard the outer levels of args, and then substitute in the + template args from the enclosing class. */ + partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args); + partial_spec_args = tsubst_template_args + (partial_spec_args, outer_args, tf_none, NULL_TREE); + + /* And the same for the partial specialization TEMPLATE_DECL. */ + spec_tmpl = tsubst (spec_tmpl, outer_args, tf_none, NULL_TREE); + } + + partial_spec_args = + coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl), + partial_spec_args, + tmpl, tf_none, + /*require_all_args=*/true, + /*use_default_args=*/true); + + --processing_template_decl; + + if (partial_spec_args == error_mark_node) + return error_mark_node; + if (spec_tmpl == error_mark_node) + return error_mark_node; + + tree parms = DECL_INNERMOST_TEMPLATE_PARMS (spec_tmpl); + spec_args = get_class_bindings (tmpl, parms, + partial_spec_args, + args); + if (spec_args) + { + if (outer_args) + spec_args = add_to_template_args (outer_args, spec_args); + list = tree_cons (spec_args, orig_parms, list); + TREE_TYPE (list) = TREE_TYPE (t); + } + } + + if (! list) + return NULL_TREE; + + ambiguous_p = false; + t = list; + champ = t; + t = TREE_CHAIN (t); + for (; t; t = TREE_CHAIN (t)) + { + fate = more_specialized_class (tmpl, champ, t); + if (fate == 1) + ; + else + { + if (fate == 0) + { + t = TREE_CHAIN (t); + if (! t) + { + ambiguous_p = true; + break; + } + } + champ = t; + } + } + + if (!ambiguous_p) + for (t = list; t && t != champ; t = TREE_CHAIN (t)) + { + fate = more_specialized_class (tmpl, champ, t); + if (fate != 1) + { + ambiguous_p = true; + break; + } + } + + if (ambiguous_p) + { + const char *str; + char *spaces = NULL; + if (!(complain & tf_error)) + return error_mark_node; + error ("ambiguous class template instantiation for %q#T", type); + str = ngettext ("candidate is:", "candidates are:", list_length (list)); + for (t = list; t; t = TREE_CHAIN (t)) + { + error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t)); + spaces = spaces ? spaces : get_spaces (str); + } + free (spaces); + return error_mark_node; + } + + return champ; +} + +/* Explicitly instantiate DECL. */ + +void +do_decl_instantiation (tree decl, tree storage) +{ + tree result = NULL_TREE; + int extern_p = 0; + + if (!decl || decl == error_mark_node) + /* An error occurred, for which grokdeclarator has already issued + an appropriate message. */ + return; + else if (! DECL_LANG_SPECIFIC (decl)) + { + error ("explicit instantiation of non-template %q#D", decl); + return; + } + else if (VAR_P (decl)) + { + /* There is an asymmetry here in the way VAR_DECLs and + FUNCTION_DECLs are handled by grokdeclarator. In the case of + the latter, the DECL we get back will be marked as a + template instantiation, and the appropriate + DECL_TEMPLATE_INFO will be set up. This does not happen for + VAR_DECLs so we do the lookup here. Probably, grokdeclarator + should handle VAR_DECLs as it currently handles + FUNCTION_DECLs. */ + if (!DECL_CLASS_SCOPE_P (decl)) + { + error ("%qD is not a static data member of a class template", decl); + return; + } + result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false); + if (!result || !VAR_P (result)) + { + error ("no matching template for %qD found", decl); + return; + } + if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl))) + { + error ("type %qT for explicit instantiation %qD does not match " + "declared type %qT", TREE_TYPE (result), decl, + TREE_TYPE (decl)); + return; + } + } + else if (TREE_CODE (decl) != FUNCTION_DECL) + { + error ("explicit instantiation of %q#D", decl); + return; + } + else + result = decl; + + /* Check for various error cases. Note that if the explicit + instantiation is valid the RESULT will currently be marked as an + *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set + until we get here. */ + + if (DECL_TEMPLATE_SPECIALIZATION (result)) + { + /* DR 259 [temp.spec]. + + Both an explicit instantiation and a declaration of an explicit + specialization shall not appear in a program unless the explicit + instantiation follows a declaration of the explicit specialization. + + For a given set of template parameters, if an explicit + instantiation of a template appears after a declaration of an + explicit specialization for that template, the explicit + instantiation has no effect. */ + return; + } + else if (DECL_EXPLICIT_INSTANTIATION (result)) + { + /* [temp.spec] + + No program shall explicitly instantiate any template more + than once. + + We check DECL_NOT_REALLY_EXTERN so as not to complain when + the first instantiation was `extern' and the second is not, + and EXTERN_P for the opposite case. */ + if (DECL_NOT_REALLY_EXTERN (result) && !extern_p) + permerror (input_location, "duplicate explicit instantiation of %q#D", result); + /* If an "extern" explicit instantiation follows an ordinary + explicit instantiation, the template is instantiated. */ + if (extern_p) + return; + } + else if (!DECL_IMPLICIT_INSTANTIATION (result)) + { + error ("no matching template for %qD found", result); + return; + } + else if (!DECL_TEMPLATE_INFO (result)) + { + permerror (input_location, "explicit instantiation of non-template %q#D", result); + return; + } + + if (storage == NULL_TREE) + ; + else if (storage == ridpointers[(int) RID_EXTERN]) + { + if (!in_system_header_at (input_location) && (cxx_dialect == cxx98)) + pedwarn (input_location, OPT_Wpedantic, + "ISO C++ 1998 forbids the use of %<extern%> on explicit " + "instantiations"); + extern_p = 1; + } + else + error ("storage class %qD applied to template instantiation", storage); + + check_explicit_instantiation_namespace (result); + mark_decl_instantiated (result, extern_p); + if (! extern_p) + instantiate_decl (result, /*defer_ok=*/1, + /*expl_inst_class_mem_p=*/false); +} + +static void +mark_class_instantiated (tree t, int extern_p) +{ + SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t); + SET_CLASSTYPE_INTERFACE_KNOWN (t); + CLASSTYPE_INTERFACE_ONLY (t) = extern_p; + TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p; + if (! extern_p) + { + CLASSTYPE_DEBUG_REQUESTED (t) = 1; + rest_of_type_compilation (t, 1); + } +} + +/* Called from do_type_instantiation through binding_table_foreach to + do recursive instantiation for the type bound in ENTRY. */ +static void +bt_instantiate_type_proc (binding_entry entry, void *data) +{ + tree storage = *(tree *) data; + + if (MAYBE_CLASS_TYPE_P (entry->type) + && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type))) + do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0); +} + +/* Called from do_type_instantiation to instantiate a member + (a member function or a static member variable) of an + explicitly instantiated class template. */ +static void +instantiate_class_member (tree decl, int extern_p) +{ + mark_decl_instantiated (decl, extern_p); + if (! extern_p) + instantiate_decl (decl, /*defer_ok=*/1, + /*expl_inst_class_mem_p=*/true); +} + +/* Perform an explicit instantiation of template class T. STORAGE, if + non-null, is the RID for extern, inline or static. COMPLAIN is + nonzero if this is called from the parser, zero if called recursively, + since the standard is unclear (as detailed below). */ + +void +do_type_instantiation (tree t, tree storage, tsubst_flags_t complain) +{ + int extern_p = 0; + int nomem_p = 0; + int static_p = 0; + int previous_instantiation_extern_p = 0; + + if (TREE_CODE (t) == TYPE_DECL) + t = TREE_TYPE (t); + + if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t)) + { + tree tmpl = + (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL; + if (tmpl) + error ("explicit instantiation of non-class template %qD", tmpl); + else + error ("explicit instantiation of non-template type %qT", t); + return; + } + + complete_type (t); + + if (!COMPLETE_TYPE_P (t)) + { + if (complain & tf_error) + error ("explicit instantiation of %q#T before definition of template", + t); + return; + } + + if (storage != NULL_TREE) + { + if (!in_system_header_at (input_location)) + { + if (storage == ridpointers[(int) RID_EXTERN]) + { + if (cxx_dialect == cxx98) + pedwarn (input_location, OPT_Wpedantic, + "ISO C++ 1998 forbids the use of %<extern%> on " + "explicit instantiations"); + } + else + pedwarn (input_location, OPT_Wpedantic, + "ISO C++ forbids the use of %qE" + " on explicit instantiations", storage); + } + + if (storage == ridpointers[(int) RID_INLINE]) + nomem_p = 1; + else if (storage == ridpointers[(int) RID_EXTERN]) + extern_p = 1; + else if (storage == ridpointers[(int) RID_STATIC]) + static_p = 1; + else + { + error ("storage class %qD applied to template instantiation", + storage); + extern_p = 0; + } + } + + if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t)) + { + /* DR 259 [temp.spec]. + + Both an explicit instantiation and a declaration of an explicit + specialization shall not appear in a program unless the explicit + instantiation follows a declaration of the explicit specialization. + + For a given set of template parameters, if an explicit + instantiation of a template appears after a declaration of an + explicit specialization for that template, the explicit + instantiation has no effect. */ + return; + } + else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t)) + { + /* [temp.spec] + + No program shall explicitly instantiate any template more + than once. + + If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit + instantiation was `extern'. If EXTERN_P then the second is. + These cases are OK. */ + previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t); + + if (!previous_instantiation_extern_p && !extern_p + && (complain & tf_error)) + permerror (input_location, "duplicate explicit instantiation of %q#T", t); + + /* If we've already instantiated the template, just return now. */ + if (!CLASSTYPE_INTERFACE_ONLY (t)) + return; + } + + check_explicit_instantiation_namespace (TYPE_NAME (t)); + mark_class_instantiated (t, extern_p); + + if (nomem_p) + return; + + { + tree tmp; + + /* In contrast to implicit instantiation, where only the + declarations, and not the definitions, of members are + instantiated, we have here: + + [temp.explicit] + + The explicit instantiation of a class template specialization + implies the instantiation of all of its members not + previously explicitly specialized in the translation unit + containing the explicit instantiation. + + Of course, we can't instantiate member template classes, since + we don't have any arguments for them. Note that the standard + is unclear on whether the instantiation of the members are + *explicit* instantiations or not. However, the most natural + interpretation is that it should be an explicit instantiation. */ + + if (! static_p) + for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp)) + if (TREE_CODE (tmp) == FUNCTION_DECL + && DECL_TEMPLATE_INSTANTIATION (tmp)) + instantiate_class_member (tmp, extern_p); + + for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp)) + if (VAR_P (tmp) && DECL_TEMPLATE_INSTANTIATION (tmp)) + instantiate_class_member (tmp, extern_p); + + if (CLASSTYPE_NESTED_UTDS (t)) + binding_table_foreach (CLASSTYPE_NESTED_UTDS (t), + bt_instantiate_type_proc, &storage); + } +} + +/* Given a function DECL, which is a specialization of TMPL, modify + DECL to be a re-instantiation of TMPL with the same template + arguments. TMPL should be the template into which tsubst'ing + should occur for DECL, not the most general template. + + One reason for doing this is a scenario like this: + + template <class T> + void f(const T&, int i); + + void g() { f(3, 7); } + + template <class T> + void f(const T& t, const int i) { } + + Note that when the template is first instantiated, with + instantiate_template, the resulting DECL will have no name for the + first parameter, and the wrong type for the second. So, when we go + to instantiate the DECL, we regenerate it. */ + +static void +regenerate_decl_from_template (tree decl, tree tmpl) +{ + /* The arguments used to instantiate DECL, from the most general + template. */ + tree args; + tree code_pattern; + + args = DECL_TI_ARGS (decl); + code_pattern = DECL_TEMPLATE_RESULT (tmpl); + + /* Make sure that we can see identifiers, and compute access + correctly. */ + push_access_scope (decl); + + if (TREE_CODE (decl) == FUNCTION_DECL) + { + tree decl_parm; + tree pattern_parm; + tree specs; + int args_depth; + int parms_depth; + + args_depth = TMPL_ARGS_DEPTH (args); + parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)); + if (args_depth > parms_depth) + args = get_innermost_template_args (args, parms_depth); + + specs = tsubst_exception_specification (TREE_TYPE (code_pattern), + args, tf_error, NULL_TREE, + /*defer_ok*/false); + if (specs && specs != error_mark_node) + TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl), + specs); + + /* Merge parameter declarations. */ + decl_parm = skip_artificial_parms_for (decl, + DECL_ARGUMENTS (decl)); + pattern_parm + = skip_artificial_parms_for (code_pattern, + DECL_ARGUMENTS (code_pattern)); + while (decl_parm && !DECL_PACK_P (pattern_parm)) + { + tree parm_type; + tree attributes; + + if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm)) + DECL_NAME (decl_parm) = DECL_NAME (pattern_parm); + parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error, + NULL_TREE); + parm_type = type_decays_to (parm_type); + if (!same_type_p (TREE_TYPE (decl_parm), parm_type)) + TREE_TYPE (decl_parm) = parm_type; + attributes = DECL_ATTRIBUTES (pattern_parm); + if (DECL_ATTRIBUTES (decl_parm) != attributes) + { + DECL_ATTRIBUTES (decl_parm) = attributes; + cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0); + } + decl_parm = DECL_CHAIN (decl_parm); + pattern_parm = DECL_CHAIN (pattern_parm); + } + /* Merge any parameters that match with the function parameter + pack. */ + if (pattern_parm && DECL_PACK_P (pattern_parm)) + { + int i, len; + tree expanded_types; + /* Expand the TYPE_PACK_EXPANSION that provides the types for + the parameters in this function parameter pack. */ + expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm), + args, tf_error, NULL_TREE); + len = TREE_VEC_LENGTH (expanded_types); + for (i = 0; i < len; i++) + { + tree parm_type; + tree attributes; + + if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm)) + /* Rename the parameter to include the index. */ + DECL_NAME (decl_parm) = + make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i); + parm_type = TREE_VEC_ELT (expanded_types, i); + parm_type = type_decays_to (parm_type); + if (!same_type_p (TREE_TYPE (decl_parm), parm_type)) + TREE_TYPE (decl_parm) = parm_type; + attributes = DECL_ATTRIBUTES (pattern_parm); + if (DECL_ATTRIBUTES (decl_parm) != attributes) + { + DECL_ATTRIBUTES (decl_parm) = attributes; + cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0); + } + decl_parm = DECL_CHAIN (decl_parm); + } + } + /* Merge additional specifiers from the CODE_PATTERN. */ + if (DECL_DECLARED_INLINE_P (code_pattern) + && !DECL_DECLARED_INLINE_P (decl)) + DECL_DECLARED_INLINE_P (decl) = 1; + } + else if (VAR_P (decl)) + { + DECL_INITIAL (decl) = + tsubst_expr (DECL_INITIAL (code_pattern), args, + tf_error, DECL_TI_TEMPLATE (decl), + /*integral_constant_expression_p=*/false); + if (VAR_HAD_UNKNOWN_BOUND (decl)) + TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args, + tf_error, DECL_TI_TEMPLATE (decl)); + } + else + gcc_unreachable (); + + pop_access_scope (decl); +} + +/* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be + substituted to get DECL. */ + +tree +template_for_substitution (tree decl) +{ + tree tmpl = DECL_TI_TEMPLATE (decl); + + /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern + for the instantiation. This is not always the most general + template. Consider, for example: + + template <class T> + struct S { template <class U> void f(); + template <> void f<int>(); }; + + and an instantiation of S<double>::f<int>. We want TD to be the + specialization S<T>::f<int>, not the more general S<T>::f<U>. */ + while (/* An instantiation cannot have a definition, so we need a + more general template. */ + DECL_TEMPLATE_INSTANTIATION (tmpl) + /* We must also deal with friend templates. Given: + + template <class T> struct S { + template <class U> friend void f() {}; + }; + + S<int>::f<U> say, is not an instantiation of S<T>::f<U>, + so far as the language is concerned, but that's still + where we get the pattern for the instantiation from. On + other hand, if the definition comes outside the class, say: + + template <class T> struct S { + template <class U> friend void f(); + }; + template <class U> friend void f() {} + + we don't need to look any further. That's what the check for + DECL_INITIAL is for. */ + || (TREE_CODE (decl) == FUNCTION_DECL + && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl) + && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl)))) + { + /* The present template, TD, should not be a definition. If it + were a definition, we should be using it! Note that we + cannot restructure the loop to just keep going until we find + a template with a definition, since that might go too far if + a specialization was declared, but not defined. */ + gcc_assert (!VAR_P (decl) + || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl))); + + /* Fetch the more general template. */ + tmpl = DECL_TI_TEMPLATE (tmpl); + } + + return tmpl; +} + +/* Returns true if we need to instantiate this template instance even if we + know we aren't going to emit it.. */ + +bool +always_instantiate_p (tree decl) +{ + /* We always instantiate inline functions so that we can inline them. An + explicit instantiation declaration prohibits implicit instantiation of + non-inline functions. With high levels of optimization, we would + normally inline non-inline functions -- but we're not allowed to do + that for "extern template" functions. Therefore, we check + DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */ + return ((TREE_CODE (decl) == FUNCTION_DECL + && (DECL_DECLARED_INLINE_P (decl) + || type_uses_auto (TREE_TYPE (TREE_TYPE (decl))))) + /* And we need to instantiate static data members so that + their initializers are available in integral constant + expressions. */ + || (VAR_P (decl) + && decl_maybe_constant_var_p (decl))); +} + +/* If FN has a noexcept-specifier that hasn't been instantiated yet, + instantiate it now, modifying TREE_TYPE (fn). */ + +void +maybe_instantiate_noexcept (tree fn) +{ + tree fntype, spec, noex, clone; + + /* Don't instantiate a noexcept-specification from template context. */ + if (processing_template_decl) + return; + + if (DECL_CLONED_FUNCTION_P (fn)) + fn = DECL_CLONED_FUNCTION (fn); + fntype = TREE_TYPE (fn); + spec = TYPE_RAISES_EXCEPTIONS (fntype); + + if (!DEFERRED_NOEXCEPT_SPEC_P (spec)) + return; + + noex = TREE_PURPOSE (spec); + + if (TREE_CODE (noex) == DEFERRED_NOEXCEPT) + { + if (push_tinst_level (fn)) + { + push_access_scope (fn); + push_deferring_access_checks (dk_no_deferred); + input_location = DECL_SOURCE_LOCATION (fn); + noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex), + DEFERRED_NOEXCEPT_ARGS (noex), + tf_warning_or_error, fn, + /*function_p=*/false, + /*integral_constant_expression_p=*/true); + pop_deferring_access_checks (); + pop_access_scope (fn); + pop_tinst_level (); + spec = build_noexcept_spec (noex, tf_warning_or_error); + if (spec == error_mark_node) + spec = noexcept_false_spec; + } + else + spec = noexcept_false_spec; + } + else + { + /* This is an implicitly declared function, so NOEX is a list of + other functions to evaluate and merge. */ + tree elt; + spec = noexcept_true_spec; + for (elt = noex; elt; elt = OVL_NEXT (elt)) + { + tree fn = OVL_CURRENT (elt); + tree subspec; + maybe_instantiate_noexcept (fn); + subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)); + spec = merge_exception_specifiers (spec, subspec, NULL_TREE); + } + } + + TREE_TYPE (fn) = build_exception_variant (fntype, spec); + + FOR_EACH_CLONE (clone, fn) + { + if (TREE_TYPE (clone) == fntype) + TREE_TYPE (clone) = TREE_TYPE (fn); + else + TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec); + } +} + +/* Produce the definition of D, a _DECL generated from a template. If + DEFER_OK is nonzero, then we don't have to actually do the + instantiation now; we just have to do it sometime. Normally it is + an error if this is an explicit instantiation but D is undefined. + EXPL_INST_CLASS_MEM_P is true iff D is a member of an + explicitly instantiated class template. */ + +tree +instantiate_decl (tree d, int defer_ok, + bool expl_inst_class_mem_p) +{ + tree tmpl = DECL_TI_TEMPLATE (d); + tree gen_args; + tree args; + tree td; + tree code_pattern; + tree spec; + tree gen_tmpl; + bool pattern_defined; + location_t saved_loc = input_location; + int saved_unevaluated_operand = cp_unevaluated_operand; + int saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings; + bool external_p; + tree fn_context; + bool nested; + + /* This function should only be used to instantiate templates for + functions and static member variables. */ + gcc_assert (VAR_OR_FUNCTION_DECL_P (d)); + + /* Variables are never deferred; if instantiation is required, they + are instantiated right away. That allows for better code in the + case that an expression refers to the value of the variable -- + if the variable has a constant value the referring expression can + take advantage of that fact. */ + if (VAR_P (d) + || DECL_DECLARED_CONSTEXPR_P (d)) + defer_ok = 0; + + /* Don't instantiate cloned functions. Instead, instantiate the + functions they cloned. */ + if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d)) + d = DECL_CLONED_FUNCTION (d); + + if (DECL_TEMPLATE_INSTANTIATED (d) + || (TREE_CODE (d) == FUNCTION_DECL + && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d)) + || DECL_TEMPLATE_SPECIALIZATION (d)) + /* D has already been instantiated or explicitly specialized, so + there's nothing for us to do here. + + It might seem reasonable to check whether or not D is an explicit + instantiation, and, if so, stop here. But when an explicit + instantiation is deferred until the end of the compilation, + DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do + the instantiation. */ + return d; + + /* Check to see whether we know that this template will be + instantiated in some other file, as with "extern template" + extension. */ + external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d)); + + /* In general, we do not instantiate such templates. */ + if (external_p && !always_instantiate_p (d)) + return d; + + gen_tmpl = most_general_template (tmpl); + gen_args = DECL_TI_ARGS (d); + + if (tmpl != gen_tmpl) + /* We should already have the extra args. */ + gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl)) + == TMPL_ARGS_DEPTH (gen_args)); + /* And what's in the hash table should match D. */ + gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d + || spec == NULL_TREE); + + /* This needs to happen before any tsubsting. */ + if (! push_tinst_level (d)) + return d; + + timevar_push (TV_TEMPLATE_INST); + + /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern + for the instantiation. */ + td = template_for_substitution (d); + code_pattern = DECL_TEMPLATE_RESULT (td); + + /* We should never be trying to instantiate a member of a class + template or partial specialization. */ + gcc_assert (d != code_pattern); + + if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d)) + || DECL_TEMPLATE_SPECIALIZATION (td)) + /* In the case of a friend template whose definition is provided + outside the class, we may have too many arguments. Drop the + ones we don't need. The same is true for specializations. */ + args = get_innermost_template_args + (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td))); + else + args = gen_args; + + if (TREE_CODE (d) == FUNCTION_DECL) + pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE + || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern)); + else + pattern_defined = ! DECL_IN_AGGR_P (code_pattern); + + /* We may be in the middle of deferred access check. Disable it now. */ + push_deferring_access_checks (dk_no_deferred); + + /* Unless an explicit instantiation directive has already determined + the linkage of D, remember that a definition is available for + this entity. */ + if (pattern_defined + && !DECL_INTERFACE_KNOWN (d) + && !DECL_NOT_REALLY_EXTERN (d)) + mark_definable (d); + + DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern); + DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern); + input_location = DECL_SOURCE_LOCATION (d); + + /* If D is a member of an explicitly instantiated class template, + and no definition is available, treat it like an implicit + instantiation. */ + if (!pattern_defined && expl_inst_class_mem_p + && DECL_EXPLICIT_INSTANTIATION (d)) + { + /* Leave linkage flags alone on instantiations with anonymous + visibility. */ + if (TREE_PUBLIC (d)) + { + DECL_NOT_REALLY_EXTERN (d) = 0; + DECL_INTERFACE_KNOWN (d) = 0; + } + SET_DECL_IMPLICIT_INSTANTIATION (d); + } + + if (TREE_CODE (d) == FUNCTION_DECL) + maybe_instantiate_noexcept (d); + + /* Defer all other templates, unless we have been explicitly + forbidden from doing so. */ + if (/* If there is no definition, we cannot instantiate the + template. */ + ! pattern_defined + /* If it's OK to postpone instantiation, do so. */ + || defer_ok + /* If this is a static data member that will be defined + elsewhere, we don't want to instantiate the entire data + member, but we do want to instantiate the initializer so that + we can substitute that elsewhere. */ + || (external_p && VAR_P (d))) + { + /* The definition of the static data member is now required so + we must substitute the initializer. */ + if (VAR_P (d) + && !DECL_INITIAL (d) + && DECL_INITIAL (code_pattern)) + { + tree ns; + tree init; + bool const_init = false; + + ns = decl_namespace_context (d); + push_nested_namespace (ns); + push_nested_class (DECL_CONTEXT (d)); + init = tsubst_expr (DECL_INITIAL (code_pattern), + args, + tf_warning_or_error, NULL_TREE, + /*integral_constant_expression_p=*/false); + /* Make sure the initializer is still constant, in case of + circular dependency (template/instantiate6.C). */ + const_init + = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern); + cp_finish_decl (d, init, /*init_const_expr_p=*/const_init, + /*asmspec_tree=*/NULL_TREE, + LOOKUP_ONLYCONVERTING); + pop_nested_class (); + pop_nested_namespace (ns); + } + + /* We restore the source position here because it's used by + add_pending_template. */ + input_location = saved_loc; + + if (at_eof && !pattern_defined + && DECL_EXPLICIT_INSTANTIATION (d) + && DECL_NOT_REALLY_EXTERN (d)) + /* [temp.explicit] + + The definition of a non-exported function template, a + non-exported member function template, or a non-exported + member function or static data member of a class template + shall be present in every translation unit in which it is + explicitly instantiated. */ + permerror (input_location, "explicit instantiation of %qD " + "but no definition available", d); + + /* If we're in unevaluated context, we just wanted to get the + constant value; this isn't an odr use, so don't queue + a full instantiation. */ + if (cp_unevaluated_operand != 0) + goto out; + /* ??? Historically, we have instantiated inline functions, even + when marked as "extern template". */ + if (!(external_p && VAR_P (d))) + add_pending_template (d); + goto out; + } + /* Tell the repository that D is available in this translation unit + -- and see if it is supposed to be instantiated here. */ + if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d)) + { + /* In a PCH file, despite the fact that the repository hasn't + requested instantiation in the PCH it is still possible that + an instantiation will be required in a file that includes the + PCH. */ + if (pch_file) + add_pending_template (d); + /* Instantiate inline functions so that the inliner can do its + job, even though we'll not be emitting a copy of this + function. */ + if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d))) + goto out; + } + + fn_context = decl_function_context (d); + nested = (current_function_decl != NULL_TREE); + if (!fn_context) + push_to_top_level (); + else + { + if (nested) + push_function_context (); + cp_unevaluated_operand = 0; + c_inhibit_evaluation_warnings = 0; + } + + /* Mark D as instantiated so that recursive calls to + instantiate_decl do not try to instantiate it again. */ + DECL_TEMPLATE_INSTANTIATED (d) = 1; + + /* Regenerate the declaration in case the template has been modified + by a subsequent redeclaration. */ + regenerate_decl_from_template (d, td); + + /* We already set the file and line above. Reset them now in case + they changed as a result of calling regenerate_decl_from_template. */ + input_location = DECL_SOURCE_LOCATION (d); + + if (VAR_P (d)) + { + tree init; + bool const_init = false; + + /* Clear out DECL_RTL; whatever was there before may not be right + since we've reset the type of the declaration. */ + SET_DECL_RTL (d, NULL); + DECL_IN_AGGR_P (d) = 0; + + /* The initializer is placed in DECL_INITIAL by + regenerate_decl_from_template so we don't need to + push/pop_access_scope again here. Pull it out so that + cp_finish_decl can process it. */ + init = DECL_INITIAL (d); + DECL_INITIAL (d) = NULL_TREE; + DECL_INITIALIZED_P (d) = 0; + + /* Clear DECL_EXTERNAL so that cp_finish_decl will process the + initializer. That function will defer actual emission until + we have a chance to determine linkage. */ + DECL_EXTERNAL (d) = 0; + + /* Enter the scope of D so that access-checking works correctly. */ + push_nested_class (DECL_CONTEXT (d)); + const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern); + cp_finish_decl (d, init, const_init, NULL_TREE, 0); + pop_nested_class (); + } + else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern)) + synthesize_method (d); + else if (TREE_CODE (d) == FUNCTION_DECL) + { + struct pointer_map_t *saved_local_specializations; + tree subst_decl; + tree tmpl_parm; + tree spec_parm; + tree block = NULL_TREE; + + /* Save away the current list, in case we are instantiating one + template from within the body of another. */ + saved_local_specializations = local_specializations; + + /* Set up the list of local specializations. */ + local_specializations = pointer_map_create (); + + /* Set up context. */ + if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern) + && TREE_CODE (DECL_CONTEXT (code_pattern)) == FUNCTION_DECL) + block = push_stmt_list (); + else + start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED); + + /* Some typedefs referenced from within the template code need to be + access checked at template instantiation time, i.e now. These + types were added to the template at parsing time. Let's get those + and perform the access checks then. */ + perform_typedefs_access_check (DECL_TEMPLATE_RESULT (gen_tmpl), + gen_args); + + /* Create substitution entries for the parameters. */ + subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d)); + tmpl_parm = DECL_ARGUMENTS (subst_decl); + spec_parm = DECL_ARGUMENTS (d); + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d)) + { + register_local_specialization (spec_parm, tmpl_parm); + spec_parm = skip_artificial_parms_for (d, spec_parm); + tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm); + } + for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm)) + { + if (!DECL_PACK_P (tmpl_parm)) + { + register_local_specialization (spec_parm, tmpl_parm); + spec_parm = DECL_CHAIN (spec_parm); + } + else + { + /* Register the (value) argument pack as a specialization of + TMPL_PARM, then move on. */ + tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm); + register_local_specialization (argpack, tmpl_parm); + } + } + gcc_assert (!spec_parm); + + /* Substitute into the body of the function. */ + if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern)) + tsubst_omp_udr (DECL_SAVED_TREE (code_pattern), args, + tf_warning_or_error, tmpl); + else + { + tsubst_expr (DECL_SAVED_TREE (code_pattern), args, + tf_warning_or_error, tmpl, + /*integral_constant_expression_p=*/false); + + /* Set the current input_location to the end of the function + so that finish_function knows where we are. */ + input_location + = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus; + + /* Remember if we saw an infinite loop in the template. */ + current_function_infinite_loop + = DECL_STRUCT_FUNCTION (code_pattern)->language->infinite_loop; + } + + /* We don't need the local specializations any more. */ + pointer_map_destroy (local_specializations); + local_specializations = saved_local_specializations; + + /* Finish the function. */ + if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern) + && TREE_CODE (DECL_CONTEXT (code_pattern)) == FUNCTION_DECL) + DECL_SAVED_TREE (d) = pop_stmt_list (block); + else + { + d = finish_function (0); + expand_or_defer_fn (d); + } + + if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern)) + cp_check_omp_declare_reduction (d); + } + + /* We're not deferring instantiation any more. */ + TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0; + + if (!fn_context) + pop_from_top_level (); + else if (nested) + pop_function_context (); + +out: + input_location = saved_loc; + cp_unevaluated_operand = saved_unevaluated_operand; + c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings; + pop_deferring_access_checks (); + pop_tinst_level (); + + timevar_pop (TV_TEMPLATE_INST); + + return d; +} + +/* Run through the list of templates that we wish we could + instantiate, and instantiate any we can. RETRIES is the + number of times we retry pending template instantiation. */ + +void +instantiate_pending_templates (int retries) +{ + int reconsider; + location_t saved_loc = input_location; + + /* Instantiating templates may trigger vtable generation. This in turn + may require further template instantiations. We place a limit here + to avoid infinite loop. */ + if (pending_templates && retries >= max_tinst_depth) + { + tree decl = pending_templates->tinst->decl; + + error ("template instantiation depth exceeds maximum of %d" + " instantiating %q+D, possibly from virtual table generation" + " (use -ftemplate-depth= to increase the maximum)", + max_tinst_depth, decl); + if (TREE_CODE (decl) == FUNCTION_DECL) + /* Pretend that we defined it. */ + DECL_INITIAL (decl) = error_mark_node; + return; + } + + do + { + struct pending_template **t = &pending_templates; + struct pending_template *last = NULL; + reconsider = 0; + while (*t) + { + tree instantiation = reopen_tinst_level ((*t)->tinst); + bool complete = false; + + if (TYPE_P (instantiation)) + { + tree fn; + + if (!COMPLETE_TYPE_P (instantiation)) + { + instantiate_class_template (instantiation); + if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation)) + for (fn = TYPE_METHODS (instantiation); + fn; + fn = TREE_CHAIN (fn)) + if (! DECL_ARTIFICIAL (fn)) + instantiate_decl (fn, + /*defer_ok=*/0, + /*expl_inst_class_mem_p=*/false); + if (COMPLETE_TYPE_P (instantiation)) + reconsider = 1; + } + + complete = COMPLETE_TYPE_P (instantiation); + } + else + { + if (!DECL_TEMPLATE_SPECIALIZATION (instantiation) + && !DECL_TEMPLATE_INSTANTIATED (instantiation)) + { + instantiation + = instantiate_decl (instantiation, + /*defer_ok=*/0, + /*expl_inst_class_mem_p=*/false); + if (DECL_TEMPLATE_INSTANTIATED (instantiation)) + reconsider = 1; + } + + complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation) + || DECL_TEMPLATE_INSTANTIATED (instantiation)); + } + + if (complete) + /* If INSTANTIATION has been instantiated, then we don't + need to consider it again in the future. */ + *t = (*t)->next; + else + { + last = *t; + t = &(*t)->next; + } + tinst_depth = 0; + current_tinst_level = NULL; + } + last_pending_template = last; + } + while (reconsider); + + input_location = saved_loc; +} + +/* Substitute ARGVEC into T, which is a list of initializers for + either base class or a non-static data member. The TREE_PURPOSEs + are DECLs, and the TREE_VALUEs are the initializer values. Used by + instantiate_decl. */ + +static tree +tsubst_initializer_list (tree t, tree argvec) +{ + tree inits = NULL_TREE; + + for (; t; t = TREE_CHAIN (t)) + { + tree decl; + tree init; + tree expanded_bases = NULL_TREE; + tree expanded_arguments = NULL_TREE; + int i, len = 1; + + if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION) + { + tree expr; + tree arg; + + /* Expand the base class expansion type into separate base + classes. */ + expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec, + tf_warning_or_error, + NULL_TREE); + if (expanded_bases == error_mark_node) + continue; + + /* We'll be building separate TREE_LISTs of arguments for + each base. */ + len = TREE_VEC_LENGTH (expanded_bases); + expanded_arguments = make_tree_vec (len); + for (i = 0; i < len; i++) + TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE; + + /* Build a dummy EXPR_PACK_EXPANSION that will be used to + expand each argument in the TREE_VALUE of t. */ + expr = make_node (EXPR_PACK_EXPANSION); + PACK_EXPANSION_LOCAL_P (expr) = true; + PACK_EXPANSION_PARAMETER_PACKS (expr) = + PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t)); + + if (TREE_VALUE (t) == void_type_node) + /* VOID_TYPE_NODE is used to indicate + value-initialization. */ + { + for (i = 0; i < len; i++) + TREE_VEC_ELT (expanded_arguments, i) = void_type_node; + } + else + { + /* Substitute parameter packs into each argument in the + TREE_LIST. */ + in_base_initializer = 1; + for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg)) + { + tree expanded_exprs; + + /* Expand the argument. */ + SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg)); + expanded_exprs + = tsubst_pack_expansion (expr, argvec, + tf_warning_or_error, + NULL_TREE); + if (expanded_exprs == error_mark_node) + continue; + + /* Prepend each of the expanded expressions to the + corresponding TREE_LIST in EXPANDED_ARGUMENTS. */ + for (i = 0; i < len; i++) + { + TREE_VEC_ELT (expanded_arguments, i) = + tree_cons (NULL_TREE, + TREE_VEC_ELT (expanded_exprs, i), + TREE_VEC_ELT (expanded_arguments, i)); + } + } + in_base_initializer = 0; + + /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS, + since we built them backwards. */ + for (i = 0; i < len; i++) + { + TREE_VEC_ELT (expanded_arguments, i) = + nreverse (TREE_VEC_ELT (expanded_arguments, i)); + } + } + } + + for (i = 0; i < len; ++i) + { + if (expanded_bases) + { + decl = TREE_VEC_ELT (expanded_bases, i); + decl = expand_member_init (decl); + init = TREE_VEC_ELT (expanded_arguments, i); + } + else + { + tree tmp; + decl = tsubst_copy (TREE_PURPOSE (t), argvec, + tf_warning_or_error, NULL_TREE); + + decl = expand_member_init (decl); + if (decl && !DECL_P (decl)) + in_base_initializer = 1; + + init = TREE_VALUE (t); + tmp = init; + if (init != void_type_node) + init = tsubst_expr (init, argvec, + tf_warning_or_error, NULL_TREE, + /*integral_constant_expression_p=*/false); + if (init == NULL_TREE && tmp != NULL_TREE) + /* If we had an initializer but it instantiated to nothing, + value-initialize the object. This will only occur when + the initializer was a pack expansion where the parameter + packs used in that expansion were of length zero. */ + init = void_type_node; + in_base_initializer = 0; + } + + if (decl) + { + init = build_tree_list (decl, init); + TREE_CHAIN (init) = inits; + inits = init; + } + } + } + return inits; +} + +/* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */ + +static void +set_current_access_from_decl (tree decl) +{ + if (TREE_PRIVATE (decl)) + current_access_specifier = access_private_node; + else if (TREE_PROTECTED (decl)) + current_access_specifier = access_protected_node; + else + current_access_specifier = access_public_node; +} + +/* Instantiate an enumerated type. TAG is the template type, NEWTAG + is the instantiation (which should have been created with + start_enum) and ARGS are the template arguments to use. */ + +static void +tsubst_enum (tree tag, tree newtag, tree args) +{ + tree e; + + if (SCOPED_ENUM_P (newtag)) + begin_scope (sk_scoped_enum, newtag); + + for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e)) + { + tree value; + tree decl; + + decl = TREE_VALUE (e); + /* Note that in a template enum, the TREE_VALUE is the + CONST_DECL, not the corresponding INTEGER_CST. */ + value = tsubst_expr (DECL_INITIAL (decl), + args, tf_warning_or_error, NULL_TREE, + /*integral_constant_expression_p=*/true); + + /* Give this enumeration constant the correct access. */ + set_current_access_from_decl (decl); + + /* Actually build the enumerator itself. */ + build_enumerator + (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl)); + } + + if (SCOPED_ENUM_P (newtag)) + finish_scope (); + + finish_enum_value_list (newtag); + finish_enum (newtag); + + DECL_SOURCE_LOCATION (TYPE_NAME (newtag)) + = DECL_SOURCE_LOCATION (TYPE_NAME (tag)); +} + +/* DECL is a FUNCTION_DECL that is a template specialization. Return + its type -- but without substituting the innermost set of template + arguments. So, innermost set of template parameters will appear in + the type. */ + +tree +get_mostly_instantiated_function_type (tree decl) +{ + tree fn_type; + tree tmpl; + tree targs; + tree tparms; + int parm_depth; + + tmpl = most_general_template (DECL_TI_TEMPLATE (decl)); + targs = DECL_TI_ARGS (decl); + tparms = DECL_TEMPLATE_PARMS (tmpl); + parm_depth = TMPL_PARMS_DEPTH (tparms); + + /* There should be as many levels of arguments as there are levels + of parameters. */ + gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs)); + + fn_type = TREE_TYPE (tmpl); + + if (parm_depth == 1) + /* No substitution is necessary. */ + ; + else + { + int i; + tree partial_args; + + /* Replace the innermost level of the TARGS with NULL_TREEs to + let tsubst know not to substitute for those parameters. */ + partial_args = make_tree_vec (TREE_VEC_LENGTH (targs)); + for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i) + SET_TMPL_ARGS_LEVEL (partial_args, i, + TMPL_ARGS_LEVEL (targs, i)); + SET_TMPL_ARGS_LEVEL (partial_args, + TMPL_ARGS_DEPTH (targs), + make_tree_vec (DECL_NTPARMS (tmpl))); + + /* Make sure that we can see identifiers, and compute access + correctly. */ + push_access_scope (decl); + + ++processing_template_decl; + /* Now, do the (partial) substitution to figure out the + appropriate function type. */ + fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE); + --processing_template_decl; + + /* Substitute into the template parameters to obtain the real + innermost set of parameters. This step is important if the + innermost set of template parameters contains value + parameters whose types depend on outer template parameters. */ + TREE_VEC_LENGTH (partial_args)--; + tparms = tsubst_template_parms (tparms, partial_args, tf_error); + + pop_access_scope (decl); + } + + return fn_type; +} + +/* Return truthvalue if we're processing a template different from + the last one involved in diagnostics. */ +int +problematic_instantiation_changed (void) +{ + return current_tinst_level != last_error_tinst_level; +} + +/* Remember current template involved in diagnostics. */ +void +record_last_problematic_instantiation (void) +{ + last_error_tinst_level = current_tinst_level; +} + +struct tinst_level * +current_instantiation (void) +{ + return current_tinst_level; +} + +/* [temp.param] Check that template non-type parm TYPE is of an allowable + type. Return zero for ok, nonzero for disallowed. Issue error and + warning messages under control of COMPLAIN. */ + +static int +invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain) +{ + if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) + return 0; + else if (POINTER_TYPE_P (type)) + return 0; + else if (TYPE_PTRMEM_P (type)) + return 0; + else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM) + return 0; + else if (TREE_CODE (type) == TYPENAME_TYPE) + return 0; + else if (TREE_CODE (type) == DECLTYPE_TYPE) + return 0; + else if (TREE_CODE (type) == NULLPTR_TYPE) + return 0; + + if (complain & tf_error) + { + if (type == error_mark_node) + inform (input_location, "invalid template non-type parameter"); + else + error ("%q#T is not a valid type for a template non-type parameter", + type); + } + return 1; +} + +/* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type]. + Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/ + +static bool +dependent_type_p_r (tree type) +{ + tree scope; + + /* [temp.dep.type] + + A type is dependent if it is: + + -- a template parameter. Template template parameters are types + for us (since TYPE_P holds true for them) so we handle + them here. */ + if (TREE_CODE (type) == TEMPLATE_TYPE_PARM + || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM) + return true; + /* -- a qualified-id with a nested-name-specifier which contains a + class-name that names a dependent type or whose unqualified-id + names a dependent type. */ + if (TREE_CODE (type) == TYPENAME_TYPE) + return true; + /* -- a cv-qualified type where the cv-unqualified type is + dependent. */ + type = TYPE_MAIN_VARIANT (type); + /* -- a compound type constructed from any dependent type. */ + if (TYPE_PTRMEM_P (type)) + return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type)) + || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE + (type))); + else if (TYPE_PTR_P (type) + || TREE_CODE (type) == REFERENCE_TYPE) + return dependent_type_p (TREE_TYPE (type)); + else if (TREE_CODE (type) == FUNCTION_TYPE + || TREE_CODE (type) == METHOD_TYPE) + { + tree arg_type; + + if (dependent_type_p (TREE_TYPE (type))) + return true; + for (arg_type = TYPE_ARG_TYPES (type); + arg_type; + arg_type = TREE_CHAIN (arg_type)) + if (dependent_type_p (TREE_VALUE (arg_type))) + return true; + return false; + } + /* -- an array type constructed from any dependent type or whose + size is specified by a constant expression that is + value-dependent. + + We checked for type- and value-dependence of the bounds in + compute_array_index_type, so TYPE_DEPENDENT_P is already set. */ + if (TREE_CODE (type) == ARRAY_TYPE) + { + if (TYPE_DOMAIN (type) + && dependent_type_p (TYPE_DOMAIN (type))) + return true; + return dependent_type_p (TREE_TYPE (type)); + } + + /* -- a template-id in which either the template name is a template + parameter ... */ + if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM) + return true; + /* ... or any of the template arguments is a dependent type or + an expression that is type-dependent or value-dependent. */ + else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type) + && (any_dependent_template_arguments_p + (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type))))) + return true; + + /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are + dependent; if the argument of the `typeof' expression is not + type-dependent, then it should already been have resolved. */ + if (TREE_CODE (type) == TYPEOF_TYPE + || TREE_CODE (type) == DECLTYPE_TYPE + || TREE_CODE (type) == UNDERLYING_TYPE) + return true; + + /* A template argument pack is dependent if any of its packed + arguments are. */ + if (TREE_CODE (type) == TYPE_ARGUMENT_PACK) + { + tree args = ARGUMENT_PACK_ARGS (type); + int i, len = TREE_VEC_LENGTH (args); + for (i = 0; i < len; ++i) + if (dependent_template_arg_p (TREE_VEC_ELT (args, i))) + return true; + } + + /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must + be template parameters. */ + if (TREE_CODE (type) == TYPE_PACK_EXPANSION) + return true; + + /* The standard does not specifically mention types that are local + to template functions or local classes, but they should be + considered dependent too. For example: + + template <int I> void f() { + enum E { a = I }; + S<sizeof (E)> s; + } + + The size of `E' cannot be known until the value of `I' has been + determined. Therefore, `E' must be considered dependent. */ + scope = TYPE_CONTEXT (type); + if (scope && TYPE_P (scope)) + return dependent_type_p (scope); + /* Don't use type_dependent_expression_p here, as it can lead + to infinite recursion trying to determine whether a lambda + nested in a lambda is dependent (c++/47687). */ + else if (scope && TREE_CODE (scope) == FUNCTION_DECL + && DECL_LANG_SPECIFIC (scope) + && DECL_TEMPLATE_INFO (scope) + && (any_dependent_template_arguments_p + (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope))))) + return true; + + /* Other types are non-dependent. */ + return false; +} + +/* Returns TRUE if TYPE is dependent, in the sense of + [temp.dep.type]. Note that a NULL type is considered dependent. */ + +bool +dependent_type_p (tree type) +{ + /* If there are no template parameters in scope, then there can't be + any dependent types. */ + if (!processing_template_decl) + { + /* If we are not processing a template, then nobody should be + providing us with a dependent type. */ + gcc_assert (type); + gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type)); + return false; + } + + /* If the type is NULL, we have not computed a type for the entity + in question; in that case, the type is dependent. */ + if (!type) + return true; + + /* Erroneous types can be considered non-dependent. */ + if (type == error_mark_node) + return false; + + /* If we have not already computed the appropriate value for TYPE, + do so now. */ + if (!TYPE_DEPENDENT_P_VALID (type)) + { + TYPE_DEPENDENT_P (type) = dependent_type_p_r (type); + TYPE_DEPENDENT_P_VALID (type) = 1; + } + + return TYPE_DEPENDENT_P (type); +} + +/* Returns TRUE if SCOPE is a dependent scope, in which we can't do any + lookup. In other words, a dependent type that is not the current + instantiation. */ + +bool +dependent_scope_p (tree scope) +{ + return (scope && TYPE_P (scope) && dependent_type_p (scope) + && !currently_open_class (scope)); +} + +/* T is a SCOPE_REF; return whether we need to consider it + instantiation-dependent so that we can check access at instantiation + time even though we know which member it resolves to. */ + +static bool +instantiation_dependent_scope_ref_p (tree t) +{ + if (DECL_P (TREE_OPERAND (t, 1)) + && CLASS_TYPE_P (TREE_OPERAND (t, 0)) + && accessible_in_template_p (TREE_OPERAND (t, 0), + TREE_OPERAND (t, 1))) + return false; + else + return true; +} + +/* Returns TRUE if the EXPRESSION is value-dependent, in the sense of + [temp.dep.constexpr]. EXPRESSION is already known to be a constant + expression. */ + +/* Note that this predicate is not appropriate for general expressions; + only constant expressions (that satisfy potential_constant_expression) + can be tested for value dependence. */ + +bool +value_dependent_expression_p (tree expression) +{ + if (!processing_template_decl) + return false; + + /* A name declared with a dependent type. */ + if (DECL_P (expression) && type_dependent_expression_p (expression)) + return true; + + switch (TREE_CODE (expression)) + { + case IDENTIFIER_NODE: + /* A name that has not been looked up -- must be dependent. */ + return true; + + case TEMPLATE_PARM_INDEX: + /* A non-type template parm. */ + return true; + + case CONST_DECL: + /* A non-type template parm. */ + if (DECL_TEMPLATE_PARM_P (expression)) + return true; + return value_dependent_expression_p (DECL_INITIAL (expression)); + + case VAR_DECL: + /* A constant with literal type and is initialized + with an expression that is value-dependent. + + Note that a non-dependent parenthesized initializer will have + already been replaced with its constant value, so if we see + a TREE_LIST it must be dependent. */ + if (DECL_INITIAL (expression) + && decl_constant_var_p (expression) + && (TREE_CODE (DECL_INITIAL (expression)) == TREE_LIST + || value_dependent_expression_p (DECL_INITIAL (expression)))) + return true; + return false; + + case DYNAMIC_CAST_EXPR: + case STATIC_CAST_EXPR: + case CONST_CAST_EXPR: + case REINTERPRET_CAST_EXPR: + case CAST_EXPR: + /* These expressions are value-dependent if the type to which + the cast occurs is dependent or the expression being casted + is value-dependent. */ + { + tree type = TREE_TYPE (expression); + + if (dependent_type_p (type)) + return true; + + /* A functional cast has a list of operands. */ + expression = TREE_OPERAND (expression, 0); + if (!expression) + { + /* If there are no operands, it must be an expression such + as "int()". This should not happen for aggregate types + because it would form non-constant expressions. */ + gcc_assert (cxx_dialect >= cxx11 + || INTEGRAL_OR_ENUMERATION_TYPE_P (type)); + + return false; + } + + if (TREE_CODE (expression) == TREE_LIST) + return any_value_dependent_elements_p (expression); + + return value_dependent_expression_p (expression); + } + + case SIZEOF_EXPR: + if (SIZEOF_EXPR_TYPE_P (expression)) + return dependent_type_p (TREE_TYPE (TREE_OPERAND (expression, 0))); + /* FALLTHRU */ + case ALIGNOF_EXPR: + case TYPEID_EXPR: + /* A `sizeof' expression is value-dependent if the operand is + type-dependent or is a pack expansion. */ + expression = TREE_OPERAND (expression, 0); + if (PACK_EXPANSION_P (expression)) + return true; + else if (TYPE_P (expression)) + return dependent_type_p (expression); + return instantiation_dependent_expression_p (expression); + + case AT_ENCODE_EXPR: + /* An 'encode' expression is value-dependent if the operand is + type-dependent. */ + expression = TREE_OPERAND (expression, 0); + return dependent_type_p (expression); + + case NOEXCEPT_EXPR: + expression = TREE_OPERAND (expression, 0); + return instantiation_dependent_expression_p (expression); + + case SCOPE_REF: + /* All instantiation-dependent expressions should also be considered + value-dependent. */ + return instantiation_dependent_scope_ref_p (expression); + + case COMPONENT_REF: + return (value_dependent_expression_p (TREE_OPERAND (expression, 0)) + || value_dependent_expression_p (TREE_OPERAND (expression, 1))); + + case NONTYPE_ARGUMENT_PACK: + /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument + is value-dependent. */ + { + tree values = ARGUMENT_PACK_ARGS (expression); + int i, len = TREE_VEC_LENGTH (values); + + for (i = 0; i < len; ++i) + if (value_dependent_expression_p (TREE_VEC_ELT (values, i))) + return true; + + return false; + } + + case TRAIT_EXPR: + { + tree type2 = TRAIT_EXPR_TYPE2 (expression); + return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression)) + || (type2 ? dependent_type_p (type2) : false)); + } + + case MODOP_EXPR: + return ((value_dependent_expression_p (TREE_OPERAND (expression, 0))) + || (value_dependent_expression_p (TREE_OPERAND (expression, 2)))); + + case ARRAY_REF: + return ((value_dependent_expression_p (TREE_OPERAND (expression, 0))) + || (value_dependent_expression_p (TREE_OPERAND (expression, 1)))); + + case ADDR_EXPR: + { + tree op = TREE_OPERAND (expression, 0); + return (value_dependent_expression_p (op) + || has_value_dependent_address (op)); + } + + case CALL_EXPR: + { + tree fn = get_callee_fndecl (expression); + int i, nargs; + if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression))) + return true; + nargs = call_expr_nargs (expression); + for (i = 0; i < nargs; ++i) + { + tree op = CALL_EXPR_ARG (expression, i); + /* In a call to a constexpr member function, look through the + implicit ADDR_EXPR on the object argument so that it doesn't + cause the call to be considered value-dependent. We also + look through it in potential_constant_expression. */ + if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn) + && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) + && TREE_CODE (op) == ADDR_EXPR) + op = TREE_OPERAND (op, 0); + if (value_dependent_expression_p (op)) + return true; + } + return false; + } + + case TEMPLATE_ID_EXPR: + /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be + type-dependent. */ + return type_dependent_expression_p (expression); + + case CONSTRUCTOR: + { + unsigned ix; + tree val; + FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val) + if (value_dependent_expression_p (val)) + return true; + return false; + } + + case STMT_EXPR: + /* Treat a GNU statement expression as dependent to avoid crashing + under fold_non_dependent_expr; it can't be constant. */ + return true; + + default: + /* A constant expression is value-dependent if any subexpression is + value-dependent. */ + switch (TREE_CODE_CLASS (TREE_CODE (expression))) + { + case tcc_reference: + case tcc_unary: + case tcc_comparison: + case tcc_binary: + case tcc_expression: + case tcc_vl_exp: + { + int i, len = cp_tree_operand_length (expression); + + for (i = 0; i < len; i++) + { + tree t = TREE_OPERAND (expression, i); + + /* In some cases, some of the operands may be missing.l + (For example, in the case of PREDECREMENT_EXPR, the + amount to increment by may be missing.) That doesn't + make the expression dependent. */ + if (t && value_dependent_expression_p (t)) + return true; + } + } + break; + default: + break; + } + break; + } + + /* The expression is not value-dependent. */ + return false; +} + +/* Returns TRUE if the EXPRESSION is type-dependent, in the sense of + [temp.dep.expr]. Note that an expression with no type is + considered dependent. Other parts of the compiler arrange for an + expression with type-dependent subexpressions to have no type, so + this function doesn't have to be fully recursive. */ + +bool +type_dependent_expression_p (tree expression) +{ + if (!processing_template_decl) + return false; + + if (expression == NULL_TREE || expression == error_mark_node) + return false; + + /* An unresolved name is always dependent. */ + if (identifier_p (expression) || TREE_CODE (expression) == USING_DECL) + return true; + + /* Some expression forms are never type-dependent. */ + if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR + || TREE_CODE (expression) == SIZEOF_EXPR + || TREE_CODE (expression) == ALIGNOF_EXPR + || TREE_CODE (expression) == AT_ENCODE_EXPR + || TREE_CODE (expression) == NOEXCEPT_EXPR + || TREE_CODE (expression) == TRAIT_EXPR + || TREE_CODE (expression) == TYPEID_EXPR + || TREE_CODE (expression) == DELETE_EXPR + || TREE_CODE (expression) == VEC_DELETE_EXPR + || TREE_CODE (expression) == THROW_EXPR) + return false; + + /* The types of these expressions depends only on the type to which + the cast occurs. */ + if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR + || TREE_CODE (expression) == STATIC_CAST_EXPR + || TREE_CODE (expression) == CONST_CAST_EXPR + || TREE_CODE (expression) == REINTERPRET_CAST_EXPR + || TREE_CODE (expression) == IMPLICIT_CONV_EXPR + || TREE_CODE (expression) == CAST_EXPR) + return dependent_type_p (TREE_TYPE (expression)); + + /* The types of these expressions depends only on the type created + by the expression. */ + if (TREE_CODE (expression) == NEW_EXPR + || TREE_CODE (expression) == VEC_NEW_EXPR) + { + /* For NEW_EXPR tree nodes created inside a template, either + the object type itself or a TREE_LIST may appear as the + operand 1. */ + tree type = TREE_OPERAND (expression, 1); + if (TREE_CODE (type) == TREE_LIST) + /* This is an array type. We need to check array dimensions + as well. */ + return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type))) + || value_dependent_expression_p + (TREE_OPERAND (TREE_VALUE (type), 1)); + else + return dependent_type_p (type); + } + + if (TREE_CODE (expression) == SCOPE_REF) + { + tree scope = TREE_OPERAND (expression, 0); + tree name = TREE_OPERAND (expression, 1); + + /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it + contains an identifier associated by name lookup with one or more + declarations declared with a dependent type, or...a + nested-name-specifier or qualified-id that names a member of an + unknown specialization. */ + return (type_dependent_expression_p (name) + || dependent_scope_p (scope)); + } + + if (TREE_CODE (expression) == FUNCTION_DECL + && DECL_LANG_SPECIFIC (expression) + && DECL_TEMPLATE_INFO (expression) + && (any_dependent_template_arguments_p + (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression))))) + return true; + + if (TREE_CODE (expression) == TEMPLATE_DECL + && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression)) + return false; + + if (TREE_CODE (expression) == STMT_EXPR) + expression = stmt_expr_value_expr (expression); + + if (BRACE_ENCLOSED_INITIALIZER_P (expression)) + { + tree elt; + unsigned i; + + FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt) + { + if (type_dependent_expression_p (elt)) + return true; + } + return false; + } + + /* A static data member of the current instantiation with incomplete + array type is type-dependent, as the definition and specializations + can have different bounds. */ + if (VAR_P (expression) + && DECL_CLASS_SCOPE_P (expression) + && dependent_type_p (DECL_CONTEXT (expression)) + && VAR_HAD_UNKNOWN_BOUND (expression)) + return true; + + /* An array of unknown bound depending on a variadic parameter, eg: + + template<typename... Args> + void foo (Args... args) + { + int arr[] = { args... }; + } + + template<int... vals> + void bar () + { + int arr[] = { vals... }; + } + + If the array has no length and has an initializer, it must be that + we couldn't determine its length in cp_complete_array_type because + it is dependent. */ + if (VAR_P (expression) + && TREE_CODE (TREE_TYPE (expression)) == ARRAY_TYPE + && !TYPE_DOMAIN (TREE_TYPE (expression)) + && DECL_INITIAL (expression)) + return true; + + if (TREE_TYPE (expression) == unknown_type_node) + { + if (TREE_CODE (expression) == ADDR_EXPR) + return type_dependent_expression_p (TREE_OPERAND (expression, 0)); + if (TREE_CODE (expression) == COMPONENT_REF + || TREE_CODE (expression) == OFFSET_REF) + { + if (type_dependent_expression_p (TREE_OPERAND (expression, 0))) + return true; + expression = TREE_OPERAND (expression, 1); + if (identifier_p (expression)) + return false; + } + /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */ + if (TREE_CODE (expression) == SCOPE_REF) + return false; + + /* Always dependent, on the number of arguments if nothing else. */ + if (TREE_CODE (expression) == EXPR_PACK_EXPANSION) + return true; + + if (BASELINK_P (expression)) + expression = BASELINK_FUNCTIONS (expression); + + if (TREE_CODE (expression) == TEMPLATE_ID_EXPR) + { + if (any_dependent_template_arguments_p + (TREE_OPERAND (expression, 1))) + return true; + expression = TREE_OPERAND (expression, 0); + } + gcc_assert (TREE_CODE (expression) == OVERLOAD + || TREE_CODE (expression) == FUNCTION_DECL); + + while (expression) + { + if (type_dependent_expression_p (OVL_CURRENT (expression))) + return true; + expression = OVL_NEXT (expression); + } + return false; + } + + gcc_assert (TREE_CODE (expression) != TYPE_DECL); + + return (dependent_type_p (TREE_TYPE (expression))); +} + +/* walk_tree callback function for instantiation_dependent_expression_p, + below. Returns non-zero if a dependent subexpression is found. */ + +static tree +instantiation_dependent_r (tree *tp, int *walk_subtrees, + void * /*data*/) +{ + if (TYPE_P (*tp)) + { + /* We don't have to worry about decltype currently because decltype + of an instantiation-dependent expr is a dependent type. This + might change depending on the resolution of DR 1172. */ + *walk_subtrees = false; + return NULL_TREE; + } + enum tree_code code = TREE_CODE (*tp); + switch (code) + { + /* Don't treat an argument list as dependent just because it has no + TREE_TYPE. */ + case TREE_LIST: + case TREE_VEC: + return NULL_TREE; + + case VAR_DECL: + case CONST_DECL: + /* A constant with a dependent initializer is dependent. */ + if (value_dependent_expression_p (*tp)) + return *tp; + break; + + case TEMPLATE_PARM_INDEX: + return *tp; + + /* Handle expressions with type operands. */ + case SIZEOF_EXPR: + case ALIGNOF_EXPR: + case TYPEID_EXPR: + case AT_ENCODE_EXPR: + { + tree op = TREE_OPERAND (*tp, 0); + if (code == SIZEOF_EXPR && SIZEOF_EXPR_TYPE_P (*tp)) + op = TREE_TYPE (op); + if (TYPE_P (op)) + { + if (dependent_type_p (op)) + return *tp; + else + { + *walk_subtrees = false; + return NULL_TREE; + } + } + break; + } + + case TRAIT_EXPR: + if (dependent_type_p (TRAIT_EXPR_TYPE1 (*tp)) + || (TRAIT_EXPR_TYPE2 (*tp) + && dependent_type_p (TRAIT_EXPR_TYPE2 (*tp)))) + return *tp; + *walk_subtrees = false; + return NULL_TREE; + + case COMPONENT_REF: + if (identifier_p (TREE_OPERAND (*tp, 1))) + /* In a template, finish_class_member_access_expr creates a + COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't + type-dependent, so that we can check access control at + instantiation time (PR 42277). See also Core issue 1273. */ + return *tp; + break; + + case SCOPE_REF: + if (instantiation_dependent_scope_ref_p (*tp)) + return *tp; + else + break; + + /* Treat statement-expressions as dependent. */ + case BIND_EXPR: + return *tp; + + default: + break; + } + + if (type_dependent_expression_p (*tp)) + return *tp; + else + return NULL_TREE; +} + +/* Returns TRUE if the EXPRESSION is instantiation-dependent, in the + sense defined by the ABI: + + "An expression is instantiation-dependent if it is type-dependent + or value-dependent, or it has a subexpression that is type-dependent + or value-dependent." */ + +bool +instantiation_dependent_expression_p (tree expression) +{ + tree result; + + if (!processing_template_decl) + return false; + + if (expression == error_mark_node) + return false; + + result = cp_walk_tree_without_duplicates (&expression, + instantiation_dependent_r, NULL); + return result != NULL_TREE; +} + +/* Like type_dependent_expression_p, but it also works while not processing + a template definition, i.e. during substitution or mangling. */ + +bool +type_dependent_expression_p_push (tree expr) +{ + bool b; + ++processing_template_decl; + b = type_dependent_expression_p (expr); + --processing_template_decl; + return b; +} + +/* Returns TRUE if ARGS contains a type-dependent expression. */ + +bool +any_type_dependent_arguments_p (const vec<tree, va_gc> *args) +{ + unsigned int i; + tree arg; + + FOR_EACH_VEC_SAFE_ELT (args, i, arg) + { + if (type_dependent_expression_p (arg)) + return true; + } + return false; +} + +/* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are + expressions) contains any type-dependent expressions. */ + +bool +any_type_dependent_elements_p (const_tree list) +{ + for (; list; list = TREE_CHAIN (list)) + if (type_dependent_expression_p (TREE_VALUE (list))) + return true; + + return false; +} + +/* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are + expressions) contains any value-dependent expressions. */ + +bool +any_value_dependent_elements_p (const_tree list) +{ + for (; list; list = TREE_CHAIN (list)) + if (value_dependent_expression_p (TREE_VALUE (list))) + return true; + + return false; +} + +/* Returns TRUE if the ARG (a template argument) is dependent. */ + +bool +dependent_template_arg_p (tree arg) +{ + if (!processing_template_decl) + return false; + + /* Assume a template argument that was wrongly written by the user + is dependent. This is consistent with what + any_dependent_template_arguments_p [that calls this function] + does. */ + if (!arg || arg == error_mark_node) + return true; + + if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT) + arg = ARGUMENT_PACK_SELECT_ARG (arg); + + if (TREE_CODE (arg) == TEMPLATE_DECL + || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM) + return dependent_template_p (arg); + else if (ARGUMENT_PACK_P (arg)) + { + tree args = ARGUMENT_PACK_ARGS (arg); + int i, len = TREE_VEC_LENGTH (args); + for (i = 0; i < len; ++i) + { + if (dependent_template_arg_p (TREE_VEC_ELT (args, i))) + return true; + } + + return false; + } + else if (TYPE_P (arg)) + return dependent_type_p (arg); + else + return (type_dependent_expression_p (arg) + || value_dependent_expression_p (arg)); +} + +/* Returns true if ARGS (a collection of template arguments) contains + any types that require structural equality testing. */ + +bool +any_template_arguments_need_structural_equality_p (tree args) +{ + int i; + int j; + + if (!args) + return false; + if (args == error_mark_node) + return true; + + for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i) + { + tree level = TMPL_ARGS_LEVEL (args, i + 1); + for (j = 0; j < TREE_VEC_LENGTH (level); ++j) + { + tree arg = TREE_VEC_ELT (level, j); + tree packed_args = NULL_TREE; + int k, len = 1; + + if (ARGUMENT_PACK_P (arg)) + { + /* Look inside the argument pack. */ + packed_args = ARGUMENT_PACK_ARGS (arg); + len = TREE_VEC_LENGTH (packed_args); + } + + for (k = 0; k < len; ++k) + { + if (packed_args) + arg = TREE_VEC_ELT (packed_args, k); + + if (error_operand_p (arg)) + return true; + else if (TREE_CODE (arg) == TEMPLATE_DECL) + continue; + else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg)) + return true; + else if (!TYPE_P (arg) && TREE_TYPE (arg) + && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg))) + return true; + } + } + } + + return false; +} + +/* Returns true if ARGS (a collection of template arguments) contains + any dependent arguments. */ + +bool +any_dependent_template_arguments_p (const_tree args) +{ + int i; + int j; + + if (!args) + return false; + if (args == error_mark_node) + return true; + + for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i) + { + const_tree level = TMPL_ARGS_LEVEL (args, i + 1); + for (j = 0; j < TREE_VEC_LENGTH (level); ++j) + if (dependent_template_arg_p (TREE_VEC_ELT (level, j))) + return true; + } + + return false; +} + +/* Returns TRUE if the template TMPL is dependent. */ + +bool +dependent_template_p (tree tmpl) +{ + if (TREE_CODE (tmpl) == OVERLOAD) + { + while (tmpl) + { + if (dependent_template_p (OVL_CURRENT (tmpl))) + return true; + tmpl = OVL_NEXT (tmpl); + } + return false; + } + + /* Template template parameters are dependent. */ + if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl) + || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM) + return true; + /* So are names that have not been looked up. */ + if (TREE_CODE (tmpl) == SCOPE_REF || identifier_p (tmpl)) + return true; + /* So are member templates of dependent classes. */ + if (TYPE_P (CP_DECL_CONTEXT (tmpl))) + return dependent_type_p (DECL_CONTEXT (tmpl)); + return false; +} + +/* Returns TRUE if the specialization TMPL<ARGS> is dependent. */ + +bool +dependent_template_id_p (tree tmpl, tree args) +{ + return (dependent_template_p (tmpl) + || any_dependent_template_arguments_p (args)); +} + +/* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors + is dependent. */ + +bool +dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv) +{ + int i; + + if (!processing_template_decl) + return false; + + for (i = 0; i < TREE_VEC_LENGTH (declv); i++) + { + tree decl = TREE_VEC_ELT (declv, i); + tree init = TREE_VEC_ELT (initv, i); + tree cond = TREE_VEC_ELT (condv, i); + tree incr = TREE_VEC_ELT (incrv, i); + + if (type_dependent_expression_p (decl)) + return true; + + if (init && type_dependent_expression_p (init)) + return true; + + if (type_dependent_expression_p (cond)) + return true; + + if (COMPARISON_CLASS_P (cond) + && (type_dependent_expression_p (TREE_OPERAND (cond, 0)) + || type_dependent_expression_p (TREE_OPERAND (cond, 1)))) + return true; + + if (TREE_CODE (incr) == MODOP_EXPR) + { + if (type_dependent_expression_p (TREE_OPERAND (incr, 0)) + || type_dependent_expression_p (TREE_OPERAND (incr, 2))) + return true; + } + else if (type_dependent_expression_p (incr)) + return true; + else if (TREE_CODE (incr) == MODIFY_EXPR) + { + if (type_dependent_expression_p (TREE_OPERAND (incr, 0))) + return true; + else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1))) + { + tree t = TREE_OPERAND (incr, 1); + if (type_dependent_expression_p (TREE_OPERAND (t, 0)) + || type_dependent_expression_p (TREE_OPERAND (t, 1))) + return true; + } + } + } + + return false; +} + +/* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the + TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if + no such TYPE can be found. Note that this function peers inside + uninstantiated templates and therefore should be used only in + extremely limited situations. ONLY_CURRENT_P restricts this + peering to the currently open classes hierarchy (which is required + when comparing types). */ + +tree +resolve_typename_type (tree type, bool only_current_p) +{ + tree scope; + tree name; + tree decl; + int quals; + tree pushed_scope; + tree result; + + gcc_assert (TREE_CODE (type) == TYPENAME_TYPE); + + scope = TYPE_CONTEXT (type); + /* Usually the non-qualified identifier of a TYPENAME_TYPE is + TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of + a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing + the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified + identifier of the TYPENAME_TYPE anymore. + So by getting the TYPE_IDENTIFIER of the _main declaration_ of the + TYPENAME_TYPE instead, we avoid messing up with a possible + typedef variant case. */ + name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type)); + + /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve + it first before we can figure out what NAME refers to. */ + if (TREE_CODE (scope) == TYPENAME_TYPE) + { + if (TYPENAME_IS_RESOLVING_P (scope)) + /* Given a class template A with a dependent base with nested type C, + typedef typename A::C::C C will land us here, as trying to resolve + the initial A::C leads to the local C typedef, which leads back to + A::C::C. So we break the recursion now. */ + return type; + else + scope = resolve_typename_type (scope, only_current_p); + } + /* If we don't know what SCOPE refers to, then we cannot resolve the + TYPENAME_TYPE. */ + if (TREE_CODE (scope) == TYPENAME_TYPE) + return type; + /* If the SCOPE is a template type parameter, we have no way of + resolving the name. */ + if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM) + return type; + /* If the SCOPE is not the current instantiation, there's no reason + to look inside it. */ + if (only_current_p && !currently_open_class (scope)) + return type; + /* If this is a typedef, we don't want to look inside (c++/11987). */ + if (typedef_variant_p (type)) + return type; + /* If SCOPE isn't the template itself, it will not have a valid + TYPE_FIELDS list. */ + if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope))) + /* scope is either the template itself or a compatible instantiation + like X<T>, so look up the name in the original template. */ + scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope); + else + /* scope is a partial instantiation, so we can't do the lookup or we + will lose the template arguments. */ + return type; + /* Enter the SCOPE so that name lookup will be resolved as if we + were in the class definition. In particular, SCOPE will no + longer be considered a dependent type. */ + pushed_scope = push_scope (scope); + /* Look up the declaration. */ + decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true, + tf_warning_or_error); + + result = NULL_TREE; + + /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to + find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */ + if (!decl) + /*nop*/; + else if (identifier_p (TYPENAME_TYPE_FULLNAME (type)) + && TREE_CODE (decl) == TYPE_DECL) + { + result = TREE_TYPE (decl); + if (result == error_mark_node) + result = NULL_TREE; + } + else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR + && DECL_CLASS_TEMPLATE_P (decl)) + { + tree tmpl; + tree args; + /* Obtain the template and the arguments. */ + tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0); + args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1); + /* Instantiate the template. */ + result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE, + /*entering_scope=*/0, + tf_error | tf_user); + if (result == error_mark_node) + result = NULL_TREE; + } + + /* Leave the SCOPE. */ + if (pushed_scope) + pop_scope (pushed_scope); + + /* If we failed to resolve it, return the original typename. */ + if (!result) + return type; + + /* If lookup found a typename type, resolve that too. */ + if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result)) + { + /* Ill-formed programs can cause infinite recursion here, so we + must catch that. */ + TYPENAME_IS_RESOLVING_P (type) = 1; + result = resolve_typename_type (result, only_current_p); + TYPENAME_IS_RESOLVING_P (type) = 0; + } + + /* Qualify the resulting type. */ + quals = cp_type_quals (type); + if (quals) + result = cp_build_qualified_type (result, cp_type_quals (result) | quals); + + return result; +} + +/* EXPR is an expression which is not type-dependent. Return a proxy + for EXPR that can be used to compute the types of larger + expressions containing EXPR. */ + +tree +build_non_dependent_expr (tree expr) +{ + tree inner_expr; + +#ifdef ENABLE_CHECKING + /* Try to get a constant value for all non-dependent expressions in + order to expose bugs in *_dependent_expression_p and constexpr. */ + if (cxx_dialect >= cxx11) + maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none)); +#endif + + /* Preserve OVERLOADs; the functions must be available to resolve + types. */ + inner_expr = expr; + if (TREE_CODE (inner_expr) == STMT_EXPR) + inner_expr = stmt_expr_value_expr (inner_expr); + if (TREE_CODE (inner_expr) == ADDR_EXPR) + inner_expr = TREE_OPERAND (inner_expr, 0); + if (TREE_CODE (inner_expr) == COMPONENT_REF) + inner_expr = TREE_OPERAND (inner_expr, 1); + if (is_overloaded_fn (inner_expr) + || TREE_CODE (inner_expr) == OFFSET_REF) + return expr; + /* There is no need to return a proxy for a variable. */ + if (VAR_P (expr)) + return expr; + /* Preserve string constants; conversions from string constants to + "char *" are allowed, even though normally a "const char *" + cannot be used to initialize a "char *". */ + if (TREE_CODE (expr) == STRING_CST) + return expr; + /* Preserve arithmetic constants, as an optimization -- there is no + reason to create a new node. */ + if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST) + return expr; + /* Preserve THROW_EXPRs -- all throw-expressions have type "void". + There is at least one place where we want to know that a + particular expression is a throw-expression: when checking a ?: + expression, there are special rules if the second or third + argument is a throw-expression. */ + if (TREE_CODE (expr) == THROW_EXPR) + return expr; + + /* Don't wrap an initializer list, we need to be able to look inside. */ + if (BRACE_ENCLOSED_INITIALIZER_P (expr)) + return expr; + + /* Don't wrap a dummy object, we need to be able to test for it. */ + if (is_dummy_object (expr)) + return expr; + + if (TREE_CODE (expr) == COND_EXPR) + return build3 (COND_EXPR, + TREE_TYPE (expr), + TREE_OPERAND (expr, 0), + (TREE_OPERAND (expr, 1) + ? build_non_dependent_expr (TREE_OPERAND (expr, 1)) + : build_non_dependent_expr (TREE_OPERAND (expr, 0))), + build_non_dependent_expr (TREE_OPERAND (expr, 2))); + if (TREE_CODE (expr) == COMPOUND_EXPR + && !COMPOUND_EXPR_OVERLOADED (expr)) + return build2 (COMPOUND_EXPR, + TREE_TYPE (expr), + TREE_OPERAND (expr, 0), + build_non_dependent_expr (TREE_OPERAND (expr, 1))); + + /* If the type is unknown, it can't really be non-dependent */ + gcc_assert (TREE_TYPE (expr) != unknown_type_node); + + /* Otherwise, build a NON_DEPENDENT_EXPR. */ + return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr); +} + +/* ARGS is a vector of expressions as arguments to a function call. + Replace the arguments with equivalent non-dependent expressions. + This modifies ARGS in place. */ + +void +make_args_non_dependent (vec<tree, va_gc> *args) +{ + unsigned int ix; + tree arg; + + FOR_EACH_VEC_SAFE_ELT (args, ix, arg) + { + tree newarg = build_non_dependent_expr (arg); + if (newarg != arg) + (*args)[ix] = newarg; + } +} + +/* Returns a type which represents 'auto' or 'decltype(auto)'. We use a + TEMPLATE_TYPE_PARM with a level one deeper than the actual template + parms. */ + +static tree +make_auto_1 (tree name) +{ + tree au = cxx_make_type (TEMPLATE_TYPE_PARM); + TYPE_NAME (au) = build_decl (input_location, + TYPE_DECL, name, au); + TYPE_STUB_DECL (au) = TYPE_NAME (au); + TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index + (0, processing_template_decl + 1, processing_template_decl + 1, + TYPE_NAME (au), NULL_TREE); + TYPE_CANONICAL (au) = canonical_type_parameter (au); + DECL_ARTIFICIAL (TYPE_NAME (au)) = 1; + SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au)); + + return au; +} + +tree +make_decltype_auto (void) +{ + return make_auto_1 (get_identifier ("decltype(auto)")); +} + +tree +make_auto (void) +{ + return make_auto_1 (get_identifier ("auto")); +} + +/* Given type ARG, return std::initializer_list<ARG>. */ + +static tree +listify (tree arg) +{ + tree std_init_list = namespace_binding + (get_identifier ("initializer_list"), std_node); + tree argvec; + if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list)) + { + error ("deducing from brace-enclosed initializer list requires " + "#include <initializer_list>"); + return error_mark_node; + } + argvec = make_tree_vec (1); + TREE_VEC_ELT (argvec, 0) = arg; + return lookup_template_class (std_init_list, argvec, NULL_TREE, + NULL_TREE, 0, tf_warning_or_error); +} + +/* Replace auto in TYPE with std::initializer_list<auto>. */ + +static tree +listify_autos (tree type, tree auto_node) +{ + tree init_auto = listify (auto_node); + tree argvec = make_tree_vec (1); + TREE_VEC_ELT (argvec, 0) = init_auto; + if (processing_template_decl) + argvec = add_to_template_args (current_template_args (), argvec); + return tsubst (type, argvec, tf_warning_or_error, NULL_TREE); +} + +/* Replace occurrences of 'auto' in TYPE with the appropriate type deduced + from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */ + +tree +do_auto_deduction (tree type, tree init, tree auto_node) +{ + tree targs; + + if (init == error_mark_node) + return error_mark_node; + + if (type_dependent_expression_p (init)) + /* Defining a subset of type-dependent expressions that we can deduce + from ahead of time isn't worth the trouble. */ + return type; + + /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto + with either a new invented type template parameter U or, if the + initializer is a braced-init-list (8.5.4), with + std::initializer_list<U>. */ + if (BRACE_ENCLOSED_INITIALIZER_P (init)) + type = listify_autos (type, auto_node); + + init = resolve_nondeduced_context (init); + + targs = make_tree_vec (1); + if (AUTO_IS_DECLTYPE (auto_node)) + { + bool id = (DECL_P (init) || (TREE_CODE (init) == COMPONENT_REF + && !REF_PARENTHESIZED_P (init))); + TREE_VEC_ELT (targs, 0) + = finish_decltype_type (init, id, tf_warning_or_error); + if (type != auto_node) + { + error ("%qT as type rather than plain %<decltype(auto)%>", type); + return error_mark_node; + } + } + else + { + tree parms = build_tree_list (NULL_TREE, type); + tree tparms = make_tree_vec (1); + int val; + + TREE_VEC_ELT (tparms, 0) + = build_tree_list (NULL_TREE, TYPE_NAME (auto_node)); + val = type_unification_real (tparms, targs, parms, &init, 1, 0, + DEDUCE_CALL, LOOKUP_NORMAL, + NULL, /*explain_p=*/false); + if (val > 0) + { + if (processing_template_decl) + /* Try again at instantiation time. */ + return type; + if (type && type != error_mark_node) + /* If type is error_mark_node a diagnostic must have been + emitted by now. Also, having a mention to '<type error>' + in the diagnostic is not really useful to the user. */ + { + if (cfun && auto_node == current_function_auto_return_pattern + && LAMBDA_FUNCTION_P (current_function_decl)) + error ("unable to deduce lambda return type from %qE", init); + else + error ("unable to deduce %qT from %qE", type, init); + } + return error_mark_node; + } + } + + /* If the list of declarators contains more than one declarator, the type + of each declared variable is determined as described above. If the + type deduced for the template parameter U is not the same in each + deduction, the program is ill-formed. */ + if (TREE_TYPE (auto_node) + && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0))) + { + if (cfun && auto_node == current_function_auto_return_pattern + && LAMBDA_FUNCTION_P (current_function_decl)) + error ("inconsistent types %qT and %qT deduced for " + "lambda return type", TREE_TYPE (auto_node), + TREE_VEC_ELT (targs, 0)); + else + error ("inconsistent deduction for %qT: %qT and then %qT", + auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)); + return error_mark_node; + } + TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0); + + if (processing_template_decl) + targs = add_to_template_args (current_template_args (), targs); + return tsubst (type, targs, tf_warning_or_error, NULL_TREE); +} + +/* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the + result. */ + +tree +splice_late_return_type (tree type, tree late_return_type) +{ + tree argvec; + + if (late_return_type == NULL_TREE) + return type; + argvec = make_tree_vec (1); + TREE_VEC_ELT (argvec, 0) = late_return_type; + if (processing_template_parmlist) + /* For a late-specified return type in a template type-parameter, we + need to add a dummy argument level for its parmlist. */ + argvec = add_to_template_args + (make_tree_vec (processing_template_parmlist), argvec); + if (current_template_parms) + argvec = add_to_template_args (current_template_args (), argvec); + return tsubst (type, argvec, tf_warning_or_error, NULL_TREE); +} + +/* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or + 'decltype(auto)'. */ + +bool +is_auto (const_tree type) +{ + if (TREE_CODE (type) == TEMPLATE_TYPE_PARM + && (TYPE_IDENTIFIER (type) == get_identifier ("auto") + || TYPE_IDENTIFIER (type) == get_identifier ("decltype(auto)"))) + return true; + else + return false; +} + +/* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains + a use of `auto'. Returns NULL_TREE otherwise. */ + +tree +type_uses_auto (tree type) +{ + return find_type_usage (type, is_auto); +} + +/* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto', + 'decltype(auto)' or a concept. */ + +bool +is_auto_or_concept (const_tree type) +{ + return is_auto (type); // or concept +} + +/* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or + a concept identifier) iff TYPE contains a use of a generic type. Returns + NULL_TREE otherwise. */ + +tree +type_uses_auto_or_concept (tree type) +{ + return find_type_usage (type, is_auto_or_concept); +} + + +/* For a given template T, return the vector of typedefs referenced + in T for which access check is needed at T instantiation time. + T is either a FUNCTION_DECL or a RECORD_TYPE. + Those typedefs were added to T by the function + append_type_to_template_for_access_check. */ + +vec<qualified_typedef_usage_t, va_gc> * +get_types_needing_access_check (tree t) +{ + tree ti; + vec<qualified_typedef_usage_t, va_gc> *result = NULL; + + if (!t || t == error_mark_node) + return NULL; + + if (!(ti = get_template_info (t))) + return NULL; + + if (CLASS_TYPE_P (t) + || TREE_CODE (t) == FUNCTION_DECL) + { + if (!TI_TEMPLATE (ti)) + return NULL; + + result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti); + } + + return result; +} + +/* Append the typedef TYPE_DECL used in template T to a list of typedefs + tied to T. That list of typedefs will be access checked at + T instantiation time. + T is either a FUNCTION_DECL or a RECORD_TYPE. + TYPE_DECL is a TYPE_DECL node representing a typedef. + SCOPE is the scope through which TYPE_DECL is accessed. + LOCATION is the location of the usage point of TYPE_DECL. + + This function is a subroutine of + append_type_to_template_for_access_check. */ + +static void +append_type_to_template_for_access_check_1 (tree t, + tree type_decl, + tree scope, + location_t location) +{ + qualified_typedef_usage_t typedef_usage; + tree ti; + + if (!t || t == error_mark_node) + return; + + gcc_assert ((TREE_CODE (t) == FUNCTION_DECL + || CLASS_TYPE_P (t)) + && type_decl + && TREE_CODE (type_decl) == TYPE_DECL + && scope); + + if (!(ti = get_template_info (t))) + return; + + gcc_assert (TI_TEMPLATE (ti)); + + typedef_usage.typedef_decl = type_decl; + typedef_usage.context = scope; + typedef_usage.locus = location; + + vec_safe_push (TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti), typedef_usage); +} + +/* Append TYPE_DECL to the template TEMPL. + TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL. + At TEMPL instanciation time, TYPE_DECL will be checked to see + if it can be accessed through SCOPE. + LOCATION is the location of the usage point of TYPE_DECL. + + e.g. consider the following code snippet: + + class C + { + typedef int myint; + }; + + template<class U> struct S + { + C::myint mi; // <-- usage point of the typedef C::myint + }; + + S<char> s; + + At S<char> instantiation time, we need to check the access of C::myint + In other words, we need to check the access of the myint typedef through + the C scope. For that purpose, this function will add the myint typedef + and the scope C through which its being accessed to a list of typedefs + tied to the template S. That list will be walked at template instantiation + time and access check performed on each typedefs it contains. + Note that this particular code snippet should yield an error because + myint is private to C. */ + +void +append_type_to_template_for_access_check (tree templ, + tree type_decl, + tree scope, + location_t location) +{ + qualified_typedef_usage_t *iter; + unsigned i; + + gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL)); + + /* Make sure we don't append the type to the template twice. */ + FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (templ), i, iter) + if (iter->typedef_decl == type_decl && scope == iter->context) + return; + + append_type_to_template_for_access_check_1 (templ, type_decl, + scope, location); +} + +/* Convert the generic type parameters in PARM that match the types given in the + range [START_IDX, END_IDX) from the current_template_parms into generic type + packs. */ + +tree +convert_generic_types_to_packs (tree parm, int start_idx, int end_idx) +{ + tree current = current_template_parms; + int depth = TMPL_PARMS_DEPTH (current); + current = INNERMOST_TEMPLATE_PARMS (current); + tree replacement = make_tree_vec (TREE_VEC_LENGTH (current)); + + for (int i = 0; i < start_idx; ++i) + TREE_VEC_ELT (replacement, i) + = TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (current, i))); + + for (int i = start_idx; i < end_idx; ++i) + { + /* Create a distinct parameter pack type from the current parm and add it + to the replacement args to tsubst below into the generic function + parameter. */ + + tree o = TREE_TYPE (TREE_VALUE + (TREE_VEC_ELT (current, i))); + tree t = copy_type (o); + TEMPLATE_TYPE_PARM_INDEX (t) + = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (o), + o, 0, 0, tf_none); + TREE_TYPE (TEMPLATE_TYPE_DECL (t)) = t; + TYPE_STUB_DECL (t) = TYPE_NAME (t) = TEMPLATE_TYPE_DECL (t); + TYPE_MAIN_VARIANT (t) = t; + TEMPLATE_TYPE_PARAMETER_PACK (t) = true; + TYPE_CANONICAL (t) = canonical_type_parameter (t); + TREE_VEC_ELT (replacement, i) = t; + TREE_VALUE (TREE_VEC_ELT (current, i)) = TREE_CHAIN (t); + } + + for (int i = end_idx, e = TREE_VEC_LENGTH (current); i < e; ++i) + TREE_VEC_ELT (replacement, i) + = TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (current, i))); + + /* If there are more levels then build up the replacement with the outer + template parms. */ + if (depth > 1) + replacement = add_to_template_args (template_parms_to_args + (TREE_CHAIN (current_template_parms)), + replacement); + + return tsubst (parm, replacement, tf_none, NULL_TREE); +} + + +/* Set up the hash tables for template instantiations. */ + +void +init_template_processing (void) +{ + decl_specializations = htab_create_ggc (37, + hash_specialization, + eq_specializations, + ggc_free); + type_specializations = htab_create_ggc (37, + hash_specialization, + eq_specializations, + ggc_free); +} + +/* Print stats about the template hash tables for -fstats. */ + +void +print_template_statistics (void) +{ + fprintf (stderr, "decl_specializations: size %ld, %ld elements, " + "%f collisions\n", (long) htab_size (decl_specializations), + (long) htab_elements (decl_specializations), + htab_collisions (decl_specializations)); + fprintf (stderr, "type_specializations: size %ld, %ld elements, " + "%f collisions\n", (long) htab_size (type_specializations), + (long) htab_elements (type_specializations), + htab_collisions (type_specializations)); +} + +#include "gt-cp-pt.h" |