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Diffstat (limited to 'gcc-4.8.1/gcc/ada/gcc-interface/trans.c')
| -rw-r--r-- | gcc-4.8.1/gcc/ada/gcc-interface/trans.c | 9210 |
1 files changed, 9210 insertions, 0 deletions
diff --git a/gcc-4.8.1/gcc/ada/gcc-interface/trans.c b/gcc-4.8.1/gcc/ada/gcc-interface/trans.c new file mode 100644 index 000000000..a4e5f5067 --- /dev/null +++ b/gcc-4.8.1/gcc/ada/gcc-interface/trans.c @@ -0,0 +1,9210 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * T R A N S * + * * + * C Implementation File * + * * + * Copyright (C) 1992-2013, Free Software Foundation, Inc. * + * * + * GNAT is free software; you can redistribute it and/or modify it under * + * terms of the GNU General Public License as published by the Free Soft- * + * ware Foundation; either version 3, or (at your option) any later ver- * + * sion. GNAT is distributed in the hope that it will be useful, but WITH- * + * OUT 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 distributed with GNAT; see file COPYING3. If not see * + * <http://www.gnu.org/licenses/>. * + * * + * GNAT was originally developed by the GNAT team at New York University. * + * Extensive contributions were provided by Ada Core Technologies Inc. * + * * + ****************************************************************************/ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "flags.h" +#include "ggc.h" +#include "output.h" +#include "libfuncs.h" /* For set_stack_check_libfunc. */ +#include "tree-iterator.h" +#include "gimple.h" +#include "bitmap.h" +#include "cgraph.h" +#include "target.h" +#include "common/common-target.h" + +#include "ada.h" +#include "adadecode.h" +#include "types.h" +#include "atree.h" +#include "elists.h" +#include "namet.h" +#include "nlists.h" +#include "snames.h" +#include "stringt.h" +#include "uintp.h" +#include "urealp.h" +#include "fe.h" +#include "sinfo.h" +#include "einfo.h" +#include "gadaint.h" +#include "ada-tree.h" +#include "gigi.h" + +/* We should avoid allocating more than ALLOCA_THRESHOLD bytes via alloca, + for fear of running out of stack space. If we need more, we use xmalloc + instead. */ +#define ALLOCA_THRESHOLD 1000 + +/* Let code below know whether we are targetting VMS without need of + intrusive preprocessor directives. */ +#ifndef TARGET_ABI_OPEN_VMS +#define TARGET_ABI_OPEN_VMS 0 +#endif + +/* In configurations where blocks have no end_locus attached, just + sink assignments into a dummy global. */ +#ifndef BLOCK_SOURCE_END_LOCATION +static location_t block_end_locus_sink; +#define BLOCK_SOURCE_END_LOCATION(BLOCK) block_end_locus_sink +#endif + +/* For efficient float-to-int rounding, it is necessary to know whether + floating-point arithmetic may use wider intermediate results. When + FP_ARITH_MAY_WIDEN is not defined, be conservative and only assume + that arithmetic does not widen if double precision is emulated. */ +#ifndef FP_ARITH_MAY_WIDEN +#if defined(HAVE_extendsfdf2) +#define FP_ARITH_MAY_WIDEN HAVE_extendsfdf2 +#else +#define FP_ARITH_MAY_WIDEN 0 +#endif +#endif + +/* Pointers to front-end tables accessed through macros. */ +struct Node *Nodes_Ptr; +Node_Id *Next_Node_Ptr; +Node_Id *Prev_Node_Ptr; +struct Elist_Header *Elists_Ptr; +struct Elmt_Item *Elmts_Ptr; +struct String_Entry *Strings_Ptr; +Char_Code *String_Chars_Ptr; +struct List_Header *List_Headers_Ptr; + +/* Highest number in the front-end node table. */ +int max_gnat_nodes; + +/* Current node being treated, in case abort called. */ +Node_Id error_gnat_node; + +/* True when gigi is being called on an analyzed but unexpanded + tree, and the only purpose of the call is to properly annotate + types with representation information. */ +bool type_annotate_only; + +/* Current filename without path. */ +const char *ref_filename; + + +/* List of N_Validate_Unchecked_Conversion nodes in the unit. */ +static vec<Node_Id> gnat_validate_uc_list; + +/* When not optimizing, we cache the 'First, 'Last and 'Length attributes + of unconstrained array IN parameters to avoid emitting a great deal of + redundant instructions to recompute them each time. */ +struct GTY (()) parm_attr_d { + int id; /* GTY doesn't like Entity_Id. */ + int dim; + tree first; + tree last; + tree length; +}; + +typedef struct parm_attr_d *parm_attr; + + +struct GTY(()) language_function { + vec<parm_attr, va_gc> *parm_attr_cache; + bitmap named_ret_val; + vec<tree, va_gc> *other_ret_val; + int gnat_ret; +}; + +#define f_parm_attr_cache \ + DECL_STRUCT_FUNCTION (current_function_decl)->language->parm_attr_cache + +#define f_named_ret_val \ + DECL_STRUCT_FUNCTION (current_function_decl)->language->named_ret_val + +#define f_other_ret_val \ + DECL_STRUCT_FUNCTION (current_function_decl)->language->other_ret_val + +#define f_gnat_ret \ + DECL_STRUCT_FUNCTION (current_function_decl)->language->gnat_ret + +/* A structure used to gather together information about a statement group. + We use this to gather related statements, for example the "then" part + of a IF. In the case where it represents a lexical scope, we may also + have a BLOCK node corresponding to it and/or cleanups. */ + +struct GTY((chain_next ("%h.previous"))) stmt_group { + struct stmt_group *previous; /* Previous code group. */ + tree stmt_list; /* List of statements for this code group. */ + tree block; /* BLOCK for this code group, if any. */ + tree cleanups; /* Cleanups for this code group, if any. */ +}; + +static GTY(()) struct stmt_group *current_stmt_group; + +/* List of unused struct stmt_group nodes. */ +static GTY((deletable)) struct stmt_group *stmt_group_free_list; + +/* A structure used to record information on elaboration procedures + we've made and need to process. + + ??? gnat_node should be Node_Id, but gengtype gets confused. */ + +struct GTY((chain_next ("%h.next"))) elab_info { + struct elab_info *next; /* Pointer to next in chain. */ + tree elab_proc; /* Elaboration procedure. */ + int gnat_node; /* The N_Compilation_Unit. */ +}; + +static GTY(()) struct elab_info *elab_info_list; + +/* Stack of exception pointer variables. Each entry is the VAR_DECL + that stores the address of the raised exception. Nonzero means we + are in an exception handler. Not used in the zero-cost case. */ +static GTY(()) vec<tree, va_gc> *gnu_except_ptr_stack; + +/* In ZCX case, current exception pointer. Used to re-raise it. */ +static GTY(()) tree gnu_incoming_exc_ptr; + +/* Stack for storing the current elaboration procedure decl. */ +static GTY(()) vec<tree, va_gc> *gnu_elab_proc_stack; + +/* Stack of labels to be used as a goto target instead of a return in + some functions. See processing for N_Subprogram_Body. */ +static GTY(()) vec<tree, va_gc> *gnu_return_label_stack; + +/* Stack of variable for the return value of a function with copy-in/copy-out + parameters. See processing for N_Subprogram_Body. */ +static GTY(()) vec<tree, va_gc> *gnu_return_var_stack; + +/* Structure used to record information for a range check. */ +struct GTY(()) range_check_info_d { + tree low_bound; + tree high_bound; + tree type; + tree invariant_cond; +}; + +typedef struct range_check_info_d *range_check_info; + + +/* Structure used to record information for a loop. */ +struct GTY(()) loop_info_d { + tree label; + tree loop_var; + vec<range_check_info, va_gc> *checks; +}; + +typedef struct loop_info_d *loop_info; + + +/* Stack of loop_info structures associated with LOOP_STMT nodes. */ +static GTY(()) vec<loop_info, va_gc> *gnu_loop_stack; + +/* The stacks for N_{Push,Pop}_*_Label. */ +static GTY(()) vec<tree, va_gc> *gnu_constraint_error_label_stack; +static GTY(()) vec<tree, va_gc> *gnu_storage_error_label_stack; +static GTY(()) vec<tree, va_gc> *gnu_program_error_label_stack; + +/* Map GNAT tree codes to GCC tree codes for simple expressions. */ +static enum tree_code gnu_codes[Number_Node_Kinds]; + +static void init_code_table (void); +static void Compilation_Unit_to_gnu (Node_Id); +static void record_code_position (Node_Id); +static void insert_code_for (Node_Id); +static void add_cleanup (tree, Node_Id); +static void add_stmt_list (List_Id); +static void push_exception_label_stack (vec<tree, va_gc> **, Entity_Id); +static tree build_stmt_group (List_Id, bool); +static inline bool stmt_group_may_fallthru (void); +static enum gimplify_status gnat_gimplify_stmt (tree *); +static void elaborate_all_entities (Node_Id); +static void process_freeze_entity (Node_Id); +static void process_decls (List_Id, List_Id, Node_Id, bool, bool); +static tree emit_range_check (tree, Node_Id, Node_Id); +static tree emit_index_check (tree, tree, tree, tree, Node_Id); +static tree emit_check (tree, tree, int, Node_Id); +static tree build_unary_op_trapv (enum tree_code, tree, tree, Node_Id); +static tree build_binary_op_trapv (enum tree_code, tree, tree, tree, Node_Id); +static tree convert_with_check (Entity_Id, tree, bool, bool, bool, Node_Id); +static bool addressable_p (tree, tree); +static tree assoc_to_constructor (Entity_Id, Node_Id, tree); +static tree extract_values (tree, tree); +static tree pos_to_constructor (Node_Id, tree, Entity_Id); +static void validate_unchecked_conversion (Node_Id); +static tree maybe_implicit_deref (tree); +static void set_expr_location_from_node (tree, Node_Id); +static bool set_end_locus_from_node (tree, Node_Id); +static void set_gnu_expr_location_from_node (tree, Node_Id); +static int lvalue_required_p (Node_Id, tree, bool, bool, bool); +static tree build_raise_check (int, enum exception_info_kind); +static tree create_init_temporary (const char *, tree, tree *, Node_Id); + +/* Hooks for debug info back-ends, only supported and used in a restricted set + of configurations. */ +static const char *extract_encoding (const char *) ATTRIBUTE_UNUSED; +static const char *decode_name (const char *) ATTRIBUTE_UNUSED; + +/* This is the main program of the back-end. It sets up all the table + structures and then generates code. */ + +void +gigi (Node_Id gnat_root, int max_gnat_node, int number_name ATTRIBUTE_UNUSED, + struct Node *nodes_ptr, Node_Id *next_node_ptr, Node_Id *prev_node_ptr, + struct Elist_Header *elists_ptr, struct Elmt_Item *elmts_ptr, + struct String_Entry *strings_ptr, Char_Code *string_chars_ptr, + struct List_Header *list_headers_ptr, Nat number_file, + struct File_Info_Type *file_info_ptr, + Entity_Id standard_boolean, Entity_Id standard_integer, + Entity_Id standard_character, Entity_Id standard_long_long_float, + Entity_Id standard_exception_type, Int gigi_operating_mode) +{ + Node_Id gnat_iter; + Entity_Id gnat_literal; + tree long_long_float_type, exception_type, t, ftype; + tree int64_type = gnat_type_for_size (64, 0); + struct elab_info *info; + int i; +#ifdef ORDINARY_MAP_INSTANCE + struct line_map *map; +#endif + + max_gnat_nodes = max_gnat_node; + + Nodes_Ptr = nodes_ptr; + Next_Node_Ptr = next_node_ptr; + Prev_Node_Ptr = prev_node_ptr; + Elists_Ptr = elists_ptr; + Elmts_Ptr = elmts_ptr; + Strings_Ptr = strings_ptr; + String_Chars_Ptr = string_chars_ptr; + List_Headers_Ptr = list_headers_ptr; + + type_annotate_only = (gigi_operating_mode == 1); + + /* ??? Disable the generation of the SCO instance table until after the + back-end supports instance based debug info discriminators. */ + Generate_SCO_Instance_Table = False; + + for (i = 0; i < number_file; i++) + { + /* Use the identifier table to make a permanent copy of the filename as + the name table gets reallocated after Gigi returns but before all the + debugging information is output. The __gnat_to_canonical_file_spec + call translates filenames from pragmas Source_Reference that contain + host style syntax not understood by gdb. */ + const char *filename + = IDENTIFIER_POINTER + (get_identifier + (__gnat_to_canonical_file_spec + (Get_Name_String (file_info_ptr[i].File_Name)))); + + /* We rely on the order isomorphism between files and line maps. */ + gcc_assert ((int) LINEMAPS_ORDINARY_USED (line_table) == i); + + /* We create the line map for a source file at once, with a fixed number + of columns chosen to avoid jumping over the next power of 2. */ + linemap_add (line_table, LC_ENTER, 0, filename, 1); +#ifdef ORDINARY_MAP_INSTANCE + map = LINEMAPS_ORDINARY_MAP_AT (line_table, i); + if (flag_debug_instances) + ORDINARY_MAP_INSTANCE (map) = file_info_ptr[i].Instance; +#endif + linemap_line_start (line_table, file_info_ptr[i].Num_Source_Lines, 252); + linemap_position_for_column (line_table, 252 - 1); + linemap_add (line_table, LC_LEAVE, 0, NULL, 0); + } + + gcc_assert (Nkind (gnat_root) == N_Compilation_Unit); + + /* Declare the name of the compilation unit as the first global + name in order to make the middle-end fully deterministic. */ + t = create_concat_name (Defining_Entity (Unit (gnat_root)), NULL); + first_global_object_name = ggc_strdup (IDENTIFIER_POINTER (t)); + + /* Initialize ourselves. */ + init_code_table (); + init_gnat_utils (); + + /* If we are just annotating types, give VOID_TYPE zero sizes to avoid + errors. */ + if (type_annotate_only) + { + TYPE_SIZE (void_type_node) = bitsize_zero_node; + TYPE_SIZE_UNIT (void_type_node) = size_zero_node; + } + + /* Enable GNAT stack checking method if needed */ + if (!Stack_Check_Probes_On_Target) + set_stack_check_libfunc ("_gnat_stack_check"); + + /* Retrieve alignment settings. */ + double_float_alignment = get_target_double_float_alignment (); + double_scalar_alignment = get_target_double_scalar_alignment (); + + /* Record the builtin types. Define `integer' and `character' first so that + dbx will output them first. */ + record_builtin_type ("integer", integer_type_node, false); + record_builtin_type ("character", unsigned_char_type_node, false); + record_builtin_type ("boolean", boolean_type_node, false); + record_builtin_type ("void", void_type_node, false); + + /* Save the type we made for integer as the type for Standard.Integer. */ + save_gnu_tree (Base_Type (standard_integer), + TYPE_NAME (integer_type_node), + false); + + /* Likewise for character as the type for Standard.Character. */ + save_gnu_tree (Base_Type (standard_character), + TYPE_NAME (unsigned_char_type_node), + false); + + /* Likewise for boolean as the type for Standard.Boolean. */ + save_gnu_tree (Base_Type (standard_boolean), + TYPE_NAME (boolean_type_node), + false); + gnat_literal = First_Literal (Base_Type (standard_boolean)); + t = UI_To_gnu (Enumeration_Rep (gnat_literal), boolean_type_node); + gcc_assert (t == boolean_false_node); + t = create_var_decl (get_entity_name (gnat_literal), NULL_TREE, + boolean_type_node, t, true, false, false, false, + NULL, gnat_literal); + DECL_IGNORED_P (t) = 1; + save_gnu_tree (gnat_literal, t, false); + gnat_literal = Next_Literal (gnat_literal); + t = UI_To_gnu (Enumeration_Rep (gnat_literal), boolean_type_node); + gcc_assert (t == boolean_true_node); + t = create_var_decl (get_entity_name (gnat_literal), NULL_TREE, + boolean_type_node, t, true, false, false, false, + NULL, gnat_literal); + DECL_IGNORED_P (t) = 1; + save_gnu_tree (gnat_literal, t, false); + + void_ftype = build_function_type_list (void_type_node, NULL_TREE); + ptr_void_ftype = build_pointer_type (void_ftype); + + /* Now declare run-time functions. */ + ftype = build_function_type_list (ptr_void_type_node, sizetype, NULL_TREE); + + /* malloc is a function declaration tree for a function to allocate + memory. */ + malloc_decl + = create_subprog_decl (get_identifier ("__gnat_malloc"), NULL_TREE, + ftype, NULL_TREE, false, true, true, true, NULL, + Empty); + DECL_IS_MALLOC (malloc_decl) = 1; + + /* malloc32 is a function declaration tree for a function to allocate + 32-bit memory on a 64-bit system. Needed only on 64-bit VMS. */ + malloc32_decl + = create_subprog_decl (get_identifier ("__gnat_malloc32"), NULL_TREE, + ftype, NULL_TREE, false, true, true, true, NULL, + Empty); + DECL_IS_MALLOC (malloc32_decl) = 1; + + /* free is a function declaration tree for a function to free memory. */ + free_decl + = create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE, + build_function_type_list (void_type_node, + ptr_void_type_node, + NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + + /* This is used for 64-bit multiplication with overflow checking. */ + mulv64_decl + = create_subprog_decl (get_identifier ("__gnat_mulv64"), NULL_TREE, + build_function_type_list (int64_type, int64_type, + int64_type, NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + + /* Name of the _Parent field in tagged record types. */ + parent_name_id = get_identifier (Get_Name_String (Name_uParent)); + + /* Name of the Exception_Data type defined in System.Standard_Library. */ + exception_data_name_id + = get_identifier ("system__standard_library__exception_data"); + + /* Make the types and functions used for exception processing. */ + jmpbuf_type + = build_array_type (gnat_type_for_mode (Pmode, 0), + build_index_type (size_int (5))); + record_builtin_type ("JMPBUF_T", jmpbuf_type, true); + jmpbuf_ptr_type = build_pointer_type (jmpbuf_type); + + /* Functions to get and set the jumpbuf pointer for the current thread. */ + get_jmpbuf_decl + = create_subprog_decl + (get_identifier ("system__soft_links__get_jmpbuf_address_soft"), + NULL_TREE, build_function_type_list (jmpbuf_ptr_type, NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + DECL_IGNORED_P (get_jmpbuf_decl) = 1; + + set_jmpbuf_decl + = create_subprog_decl + (get_identifier ("system__soft_links__set_jmpbuf_address_soft"), + NULL_TREE, build_function_type_list (void_type_node, jmpbuf_ptr_type, + NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + DECL_IGNORED_P (set_jmpbuf_decl) = 1; + + /* setjmp returns an integer and has one operand, which is a pointer to + a jmpbuf. */ + setjmp_decl + = create_subprog_decl + (get_identifier ("__builtin_setjmp"), NULL_TREE, + build_function_type_list (integer_type_node, jmpbuf_ptr_type, + NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL; + DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP; + + /* update_setjmp_buf updates a setjmp buffer from the current stack pointer + address. */ + update_setjmp_buf_decl + = create_subprog_decl + (get_identifier ("__builtin_update_setjmp_buf"), NULL_TREE, + build_function_type_list (void_type_node, jmpbuf_ptr_type, NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + DECL_BUILT_IN_CLASS (update_setjmp_buf_decl) = BUILT_IN_NORMAL; + DECL_FUNCTION_CODE (update_setjmp_buf_decl) = BUILT_IN_UPDATE_SETJMP_BUF; + + /* Hooks to call when entering/leaving an exception handler. */ + ftype + = build_function_type_list (void_type_node, ptr_void_type_node, NULL_TREE); + + begin_handler_decl + = create_subprog_decl (get_identifier ("__gnat_begin_handler"), NULL_TREE, + ftype, NULL_TREE, false, true, true, true, NULL, + Empty); + DECL_IGNORED_P (begin_handler_decl) = 1; + + end_handler_decl + = create_subprog_decl (get_identifier ("__gnat_end_handler"), NULL_TREE, + ftype, NULL_TREE, false, true, true, true, NULL, + Empty); + DECL_IGNORED_P (end_handler_decl) = 1; + + unhandled_except_decl + = create_subprog_decl (get_identifier ("__gnat_unhandled_except_handler"), + NULL_TREE, + ftype, NULL_TREE, false, true, true, true, NULL, + Empty); + DECL_IGNORED_P (unhandled_except_decl) = 1; + + reraise_zcx_decl + = create_subprog_decl (get_identifier ("__gnat_reraise_zcx"), NULL_TREE, + ftype, NULL_TREE, false, true, true, true, NULL, + Empty); + /* Indicate that these never return. */ + DECL_IGNORED_P (reraise_zcx_decl) = 1; + TREE_THIS_VOLATILE (reraise_zcx_decl) = 1; + TREE_SIDE_EFFECTS (reraise_zcx_decl) = 1; + TREE_TYPE (reraise_zcx_decl) + = build_qualified_type (TREE_TYPE (reraise_zcx_decl), TYPE_QUAL_VOLATILE); + + /* If in no exception handlers mode, all raise statements are redirected to + __gnat_last_chance_handler. No need to redefine raise_nodefer_decl since + this procedure will never be called in this mode. */ + if (No_Exception_Handlers_Set ()) + { + tree decl + = create_subprog_decl + (get_identifier ("__gnat_last_chance_handler"), NULL_TREE, + build_function_type_list (void_type_node, + build_pointer_type + (unsigned_char_type_node), + integer_type_node, NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + TREE_THIS_VOLATILE (decl) = 1; + TREE_SIDE_EFFECTS (decl) = 1; + TREE_TYPE (decl) + = build_qualified_type (TREE_TYPE (decl), TYPE_QUAL_VOLATILE); + for (i = 0; i < (int) ARRAY_SIZE (gnat_raise_decls); i++) + gnat_raise_decls[i] = decl; + } + else + { + /* Otherwise, make one decl for each exception reason. */ + for (i = 0; i < (int) ARRAY_SIZE (gnat_raise_decls); i++) + gnat_raise_decls[i] = build_raise_check (i, exception_simple); + for (i = 0; i < (int) ARRAY_SIZE (gnat_raise_decls_ext); i++) + gnat_raise_decls_ext[i] + = build_raise_check (i, + i == CE_Index_Check_Failed + || i == CE_Range_Check_Failed + || i == CE_Invalid_Data + ? exception_range : exception_column); + } + + /* Set the types that GCC and Gigi use from the front end. */ + exception_type + = gnat_to_gnu_entity (Base_Type (standard_exception_type), NULL_TREE, 0); + except_type_node = TREE_TYPE (exception_type); + + /* Make other functions used for exception processing. */ + get_excptr_decl + = create_subprog_decl + (get_identifier ("system__soft_links__get_gnat_exception"), NULL_TREE, + build_function_type_list (build_pointer_type (except_type_node), + NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + DECL_IGNORED_P (get_excptr_decl) = 1; + + raise_nodefer_decl + = create_subprog_decl + (get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE, + build_function_type_list (void_type_node, + build_pointer_type (except_type_node), + NULL_TREE), + NULL_TREE, false, true, true, true, NULL, Empty); + + /* Indicate that it never returns. */ + TREE_THIS_VOLATILE (raise_nodefer_decl) = 1; + TREE_SIDE_EFFECTS (raise_nodefer_decl) = 1; + TREE_TYPE (raise_nodefer_decl) + = build_qualified_type (TREE_TYPE (raise_nodefer_decl), + TYPE_QUAL_VOLATILE); + + /* Build the special descriptor type and its null node if needed. */ + if (TARGET_VTABLE_USES_DESCRIPTORS) + { + tree null_node = fold_convert (ptr_void_ftype, null_pointer_node); + tree field_list = NULL_TREE; + int j; + vec<constructor_elt, va_gc> *null_vec = NULL; + constructor_elt *elt; + + fdesc_type_node = make_node (RECORD_TYPE); + vec_safe_grow (null_vec, TARGET_VTABLE_USES_DESCRIPTORS); + elt = (null_vec->address () + TARGET_VTABLE_USES_DESCRIPTORS - 1); + + for (j = 0; j < TARGET_VTABLE_USES_DESCRIPTORS; j++) + { + tree field + = create_field_decl (NULL_TREE, ptr_void_ftype, fdesc_type_node, + NULL_TREE, NULL_TREE, 0, 1); + DECL_CHAIN (field) = field_list; + field_list = field; + elt->index = field; + elt->value = null_node; + elt--; + } + + finish_record_type (fdesc_type_node, nreverse (field_list), 0, false); + record_builtin_type ("descriptor", fdesc_type_node, true); + null_fdesc_node = gnat_build_constructor (fdesc_type_node, null_vec); + } + + long_long_float_type + = gnat_to_gnu_entity (Base_Type (standard_long_long_float), NULL_TREE, 0); + + if (TREE_CODE (TREE_TYPE (long_long_float_type)) == INTEGER_TYPE) + { + /* In this case, the builtin floating point types are VAX float, + so make up a type for use. */ + longest_float_type_node = make_node (REAL_TYPE); + TYPE_PRECISION (longest_float_type_node) = LONG_DOUBLE_TYPE_SIZE; + layout_type (longest_float_type_node); + record_builtin_type ("longest float type", longest_float_type_node, + false); + } + else + longest_float_type_node = TREE_TYPE (long_long_float_type); + + /* Dummy objects to materialize "others" and "all others" in the exception + tables. These are exported by a-exexpr-gcc.adb, so see this unit for + the types to use. */ + others_decl + = create_var_decl (get_identifier ("OTHERS"), + get_identifier ("__gnat_others_value"), + integer_type_node, NULL_TREE, true, false, true, false, + NULL, Empty); + + all_others_decl + = create_var_decl (get_identifier ("ALL_OTHERS"), + get_identifier ("__gnat_all_others_value"), + integer_type_node, NULL_TREE, true, false, true, false, + NULL, Empty); + + unhandled_others_decl + = create_var_decl (get_identifier ("UNHANDLED_OTHERS"), + get_identifier ("__gnat_unhandled_others_value"), + integer_type_node, NULL_TREE, true, false, true, false, + NULL, Empty); + + main_identifier_node = get_identifier ("main"); + + /* Install the builtins we might need, either internally or as + user available facilities for Intrinsic imports. */ + gnat_install_builtins (); + + vec_safe_push (gnu_except_ptr_stack, NULL_TREE); + vec_safe_push (gnu_constraint_error_label_stack, NULL_TREE); + vec_safe_push (gnu_storage_error_label_stack, NULL_TREE); + vec_safe_push (gnu_program_error_label_stack, NULL_TREE); + + /* Process any Pragma Ident for the main unit. */ + if (Present (Ident_String (Main_Unit))) + targetm.asm_out.output_ident + (TREE_STRING_POINTER (gnat_to_gnu (Ident_String (Main_Unit)))); + + /* If we are using the GCC exception mechanism, let GCC know. */ + if (Exception_Mechanism == Back_End_Exceptions) + gnat_init_gcc_eh (); + + /* Now translate the compilation unit proper. */ + Compilation_Unit_to_gnu (gnat_root); + + /* Then process the N_Validate_Unchecked_Conversion nodes. We do this at + the very end to avoid having to second-guess the front-end when we run + into dummy nodes during the regular processing. */ + for (i = 0; gnat_validate_uc_list.iterate (i, &gnat_iter); i++) + validate_unchecked_conversion (gnat_iter); + gnat_validate_uc_list.release (); + + /* Finally see if we have any elaboration procedures to deal with. */ + for (info = elab_info_list; info; info = info->next) + { + tree gnu_body = DECL_SAVED_TREE (info->elab_proc), gnu_stmts; + + /* We should have a BIND_EXPR but it may not have any statements in it. + If it doesn't have any, we have nothing to do except for setting the + flag on the GNAT node. Otherwise, process the function as others. */ + gnu_stmts = gnu_body; + if (TREE_CODE (gnu_stmts) == BIND_EXPR) + gnu_stmts = BIND_EXPR_BODY (gnu_stmts); + if (!gnu_stmts || !STATEMENT_LIST_HEAD (gnu_stmts)) + Set_Has_No_Elaboration_Code (info->gnat_node, 1); + else + { + begin_subprog_body (info->elab_proc); + end_subprog_body (gnu_body); + rest_of_subprog_body_compilation (info->elab_proc); + } + } + + /* Destroy ourselves. */ + destroy_gnat_utils (); + + /* We cannot track the location of errors past this point. */ + error_gnat_node = Empty; +} + +/* Return a subprogram decl corresponding to __gnat_rcheck_xx for the given + CHECK if KIND is EXCEPTION_SIMPLE, or else to __gnat_rcheck_xx_ext. */ + +static tree +build_raise_check (int check, enum exception_info_kind kind) +{ + tree result, ftype; + const char pfx[] = "__gnat_rcheck_"; + + strcpy (Name_Buffer, pfx); + Name_Len = sizeof (pfx) - 1; + Get_RT_Exception_Name (check); + + if (kind == exception_simple) + { + Name_Buffer[Name_Len] = 0; + ftype + = build_function_type_list (void_type_node, + build_pointer_type + (unsigned_char_type_node), + integer_type_node, NULL_TREE); + } + else + { + tree t = (kind == exception_column ? NULL_TREE : integer_type_node); + + strcpy (Name_Buffer + Name_Len, "_ext"); + Name_Buffer[Name_Len + 4] = 0; + ftype + = build_function_type_list (void_type_node, + build_pointer_type + (unsigned_char_type_node), + integer_type_node, integer_type_node, + t, t, NULL_TREE); + } + + result + = create_subprog_decl (get_identifier (Name_Buffer), + NULL_TREE, ftype, NULL_TREE, + false, true, true, true, NULL, Empty); + + /* Indicate that it never returns. */ + TREE_THIS_VOLATILE (result) = 1; + TREE_SIDE_EFFECTS (result) = 1; + TREE_TYPE (result) + = build_qualified_type (TREE_TYPE (result), TYPE_QUAL_VOLATILE); + + return result; +} + +/* Return a positive value if an lvalue is required for GNAT_NODE, which is + an N_Attribute_Reference. */ + +static int +lvalue_required_for_attribute_p (Node_Id gnat_node) +{ + switch (Get_Attribute_Id (Attribute_Name (gnat_node))) + { + case Attr_Pos: + case Attr_Val: + case Attr_Pred: + case Attr_Succ: + case Attr_First: + case Attr_Last: + case Attr_Range_Length: + case Attr_Length: + case Attr_Object_Size: + case Attr_Value_Size: + case Attr_Component_Size: + case Attr_Max_Size_In_Storage_Elements: + case Attr_Min: + case Attr_Max: + case Attr_Null_Parameter: + case Attr_Passed_By_Reference: + case Attr_Mechanism_Code: + return 0; + + case Attr_Address: + case Attr_Access: + case Attr_Unchecked_Access: + case Attr_Unrestricted_Access: + case Attr_Code_Address: + case Attr_Pool_Address: + case Attr_Size: + case Attr_Alignment: + case Attr_Bit_Position: + case Attr_Position: + case Attr_First_Bit: + case Attr_Last_Bit: + case Attr_Bit: + case Attr_Asm_Input: + case Attr_Asm_Output: + default: + return 1; + } +} + +/* Return a positive value if an lvalue is required for GNAT_NODE. GNU_TYPE + is the type that will be used for GNAT_NODE in the translated GNU tree. + CONSTANT indicates whether the underlying object represented by GNAT_NODE + is constant in the Ada sense. If it is, ADDRESS_OF_CONSTANT indicates + whether its value is the address of a constant and ALIASED whether it is + aliased. If it isn't, ADDRESS_OF_CONSTANT and ALIASED are ignored. + + The function climbs up the GNAT tree starting from the node and returns 1 + upon encountering a node that effectively requires an lvalue downstream. + It returns int instead of bool to facilitate usage in non-purely binary + logic contexts. */ + +static int +lvalue_required_p (Node_Id gnat_node, tree gnu_type, bool constant, + bool address_of_constant, bool aliased) +{ + Node_Id gnat_parent = Parent (gnat_node), gnat_temp; + + switch (Nkind (gnat_parent)) + { + case N_Reference: + return 1; + + case N_Attribute_Reference: + return lvalue_required_for_attribute_p (gnat_parent); + + case N_Parameter_Association: + case N_Function_Call: + case N_Procedure_Call_Statement: + /* If the parameter is by reference, an lvalue is required. */ + return (!constant + || must_pass_by_ref (gnu_type) + || default_pass_by_ref (gnu_type)); + + case N_Indexed_Component: + /* Only the array expression can require an lvalue. */ + if (Prefix (gnat_parent) != gnat_node) + return 0; + + /* ??? Consider that referencing an indexed component with a + non-constant index forces the whole aggregate to memory. + Note that N_Integer_Literal is conservative, any static + expression in the RM sense could probably be accepted. */ + for (gnat_temp = First (Expressions (gnat_parent)); + Present (gnat_temp); + gnat_temp = Next (gnat_temp)) + if (Nkind (gnat_temp) != N_Integer_Literal) + return 1; + + /* ... fall through ... */ + + case N_Slice: + /* Only the array expression can require an lvalue. */ + if (Prefix (gnat_parent) != gnat_node) + return 0; + + aliased |= Has_Aliased_Components (Etype (gnat_node)); + return lvalue_required_p (gnat_parent, gnu_type, constant, + address_of_constant, aliased); + + case N_Selected_Component: + aliased |= Is_Aliased (Entity (Selector_Name (gnat_parent))); + return lvalue_required_p (gnat_parent, gnu_type, constant, + address_of_constant, aliased); + + case N_Object_Renaming_Declaration: + /* We need to make a real renaming only if the constant object is + aliased or if we may use a renaming pointer; otherwise we can + optimize and return the rvalue. We make an exception if the object + is an identifier since in this case the rvalue can be propagated + attached to the CONST_DECL. */ + return (!constant + || aliased + /* This should match the constant case of the renaming code. */ + || Is_Composite_Type + (Underlying_Type (Etype (Name (gnat_parent)))) + || Nkind (Name (gnat_parent)) == N_Identifier); + + case N_Object_Declaration: + /* We cannot use a constructor if this is an atomic object because + the actual assignment might end up being done component-wise. */ + return (!constant + ||(Is_Composite_Type (Underlying_Type (Etype (gnat_node))) + && Is_Atomic (Defining_Entity (gnat_parent))) + /* We don't use a constructor if this is a class-wide object + because the effective type of the object is the equivalent + type of the class-wide subtype and it smashes most of the + data into an array of bytes to which we cannot convert. */ + || Ekind ((Etype (Defining_Entity (gnat_parent)))) + == E_Class_Wide_Subtype); + + case N_Assignment_Statement: + /* We cannot use a constructor if the LHS is an atomic object because + the actual assignment might end up being done component-wise. */ + return (!constant + || Name (gnat_parent) == gnat_node + || (Is_Composite_Type (Underlying_Type (Etype (gnat_node))) + && Is_Atomic (Entity (Name (gnat_parent))))); + + case N_Unchecked_Type_Conversion: + if (!constant) + return 1; + + /* ... fall through ... */ + + case N_Type_Conversion: + case N_Qualified_Expression: + /* We must look through all conversions because we may need to bypass + an intermediate conversion that is meant to be purely formal. */ + return lvalue_required_p (gnat_parent, + get_unpadded_type (Etype (gnat_parent)), + constant, address_of_constant, aliased); + + case N_Allocator: + /* We should only reach here through the N_Qualified_Expression case. + Force an lvalue for composite types since a block-copy to the newly + allocated area of memory is made. */ + return Is_Composite_Type (Underlying_Type (Etype (gnat_node))); + + case N_Explicit_Dereference: + /* We look through dereferences for address of constant because we need + to handle the special cases listed above. */ + if (constant && address_of_constant) + return lvalue_required_p (gnat_parent, + get_unpadded_type (Etype (gnat_parent)), + true, false, true); + + /* ... fall through ... */ + + default: + return 0; + } + + gcc_unreachable (); +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Identifier, + to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer + to where we should place the result type. */ + +static tree +Identifier_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p) +{ + Node_Id gnat_temp, gnat_temp_type; + tree gnu_result, gnu_result_type; + + /* Whether we should require an lvalue for GNAT_NODE. Needed in + specific circumstances only, so evaluated lazily. < 0 means + unknown, > 0 means known true, 0 means known false. */ + int require_lvalue = -1; + + /* If GNAT_NODE is a constant, whether we should use the initialization + value instead of the constant entity, typically for scalars with an + address clause when the parent doesn't require an lvalue. */ + bool use_constant_initializer = false; + + /* If the Etype of this node does not equal the Etype of the Entity, + something is wrong with the entity map, probably in generic + instantiation. However, this does not apply to types. Since we sometime + have strange Ekind's, just do this test for objects. Also, if the Etype of + the Entity is private, the Etype of the N_Identifier is allowed to be the + full type and also we consider a packed array type to be the same as the + original type. Similarly, a class-wide type is equivalent to a subtype of + itself. Finally, if the types are Itypes, one may be a copy of the other, + which is also legal. */ + gnat_temp = (Nkind (gnat_node) == N_Defining_Identifier + ? gnat_node : Entity (gnat_node)); + gnat_temp_type = Etype (gnat_temp); + + gcc_assert (Etype (gnat_node) == gnat_temp_type + || (Is_Packed (gnat_temp_type) + && Etype (gnat_node) == Packed_Array_Type (gnat_temp_type)) + || (Is_Class_Wide_Type (Etype (gnat_node))) + || (IN (Ekind (gnat_temp_type), Private_Kind) + && Present (Full_View (gnat_temp_type)) + && ((Etype (gnat_node) == Full_View (gnat_temp_type)) + || (Is_Packed (Full_View (gnat_temp_type)) + && (Etype (gnat_node) + == Packed_Array_Type (Full_View + (gnat_temp_type)))))) + || (Is_Itype (Etype (gnat_node)) && Is_Itype (gnat_temp_type)) + || !(Ekind (gnat_temp) == E_Variable + || Ekind (gnat_temp) == E_Component + || Ekind (gnat_temp) == E_Constant + || Ekind (gnat_temp) == E_Loop_Parameter + || IN (Ekind (gnat_temp), Formal_Kind))); + + /* If this is a reference to a deferred constant whose partial view is an + unconstrained private type, the proper type is on the full view of the + constant, not on the full view of the type, which may be unconstrained. + + This may be a reference to a type, for example in the prefix of the + attribute Position, generated for dispatching code (see Make_DT in + exp_disp,adb). In that case we need the type itself, not is parent, + in particular if it is a derived type */ + if (Ekind (gnat_temp) == E_Constant + && Is_Private_Type (gnat_temp_type) + && (Has_Unknown_Discriminants (gnat_temp_type) + || (Present (Full_View (gnat_temp_type)) + && Has_Discriminants (Full_View (gnat_temp_type)))) + && Present (Full_View (gnat_temp))) + { + gnat_temp = Full_View (gnat_temp); + gnat_temp_type = Etype (gnat_temp); + } + else + { + /* We want to use the Actual_Subtype if it has already been elaborated, + otherwise the Etype. Avoid using Actual_Subtype for packed arrays to + simplify things. */ + if ((Ekind (gnat_temp) == E_Constant + || Ekind (gnat_temp) == E_Variable || Is_Formal (gnat_temp)) + && !(Is_Array_Type (Etype (gnat_temp)) + && Present (Packed_Array_Type (Etype (gnat_temp)))) + && Present (Actual_Subtype (gnat_temp)) + && present_gnu_tree (Actual_Subtype (gnat_temp))) + gnat_temp_type = Actual_Subtype (gnat_temp); + else + gnat_temp_type = Etype (gnat_node); + } + + /* Expand the type of this identifier first, in case it is an enumeral + literal, which only get made when the type is expanded. There is no + order-of-elaboration issue here. */ + gnu_result_type = get_unpadded_type (gnat_temp_type); + + /* If this is a non-imported elementary constant with an address clause, + retrieve the value instead of a pointer to be dereferenced unless + an lvalue is required. This is generally more efficient and actually + required if this is a static expression because it might be used + in a context where a dereference is inappropriate, such as a case + statement alternative or a record discriminant. There is no possible + volatile-ness short-circuit here since Volatile constants must be + imported per C.6. */ + if (Ekind (gnat_temp) == E_Constant + && Is_Elementary_Type (gnat_temp_type) + && !Is_Imported (gnat_temp) + && Present (Address_Clause (gnat_temp))) + { + require_lvalue = lvalue_required_p (gnat_node, gnu_result_type, true, + false, Is_Aliased (gnat_temp)); + use_constant_initializer = !require_lvalue; + } + + if (use_constant_initializer) + { + /* If this is a deferred constant, the initializer is attached to + the full view. */ + if (Present (Full_View (gnat_temp))) + gnat_temp = Full_View (gnat_temp); + + gnu_result = gnat_to_gnu (Expression (Declaration_Node (gnat_temp))); + } + else + gnu_result = gnat_to_gnu_entity (gnat_temp, NULL_TREE, 0); + + /* Some objects (such as parameters passed by reference, globals of + variable size, and renamed objects) actually represent the address + of the object. In that case, we must do the dereference. Likewise, + deal with parameters to foreign convention subprograms. */ + if (DECL_P (gnu_result) + && (DECL_BY_REF_P (gnu_result) + || (TREE_CODE (gnu_result) == PARM_DECL + && DECL_BY_COMPONENT_PTR_P (gnu_result)))) + { + const bool read_only = DECL_POINTS_TO_READONLY_P (gnu_result); + + /* First do the first dereference if needed. */ + if (TREE_CODE (gnu_result) == PARM_DECL + && DECL_BY_DOUBLE_REF_P (gnu_result)) + { + gnu_result = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_result); + if (TREE_CODE (gnu_result) == INDIRECT_REF) + TREE_THIS_NOTRAP (gnu_result) = 1; + + /* The first reference, in case of a double reference, always points + to read-only, see gnat_to_gnu_param for the rationale. */ + TREE_READONLY (gnu_result) = 1; + } + + /* If it's a PARM_DECL to foreign convention subprogram, convert it. */ + if (TREE_CODE (gnu_result) == PARM_DECL + && DECL_BY_COMPONENT_PTR_P (gnu_result)) + gnu_result + = convert (build_pointer_type (gnu_result_type), gnu_result); + + /* If it's a CONST_DECL, return the underlying constant like below. */ + else if (TREE_CODE (gnu_result) == CONST_DECL + && !(DECL_CONST_ADDRESS_P (gnu_result) + && lvalue_required_p (gnat_node, gnu_result_type, true, + true, false))) + gnu_result = DECL_INITIAL (gnu_result); + + /* If it's a renaming pointer and we are at the right binding level, + we can reference the renamed object directly, since the renamed + expression has been protected against multiple evaluations. */ + if (TREE_CODE (gnu_result) == VAR_DECL + && !DECL_LOOP_PARM_P (gnu_result) + && DECL_RENAMED_OBJECT (gnu_result) + && (!DECL_RENAMING_GLOBAL_P (gnu_result) || global_bindings_p ())) + gnu_result = DECL_RENAMED_OBJECT (gnu_result); + + /* Otherwise, do the final dereference. */ + else + { + gnu_result = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_result); + + if ((TREE_CODE (gnu_result) == INDIRECT_REF + || TREE_CODE (gnu_result) == UNCONSTRAINED_ARRAY_REF) + && No (Address_Clause (gnat_temp))) + TREE_THIS_NOTRAP (gnu_result) = 1; + + if (read_only) + TREE_READONLY (gnu_result) = 1; + } + } + + /* If we have a constant declaration and its initializer, try to return the + latter to avoid the need to call fold in lots of places and the need for + elaboration code if this identifier is used as an initializer itself. + Don't do it for aggregate types that contain a placeholder since their + initializers cannot be manipulated easily. */ + if (TREE_CONSTANT (gnu_result) + && DECL_P (gnu_result) + && DECL_INITIAL (gnu_result) + && !(AGGREGATE_TYPE_P (TREE_TYPE (gnu_result)) + && !TYPE_IS_FAT_POINTER_P (TREE_TYPE (gnu_result)) + && type_contains_placeholder_p (TREE_TYPE (gnu_result)))) + { + bool constant_only = (TREE_CODE (gnu_result) == CONST_DECL + && !DECL_CONST_CORRESPONDING_VAR (gnu_result)); + bool address_of_constant = (TREE_CODE (gnu_result) == CONST_DECL + && DECL_CONST_ADDRESS_P (gnu_result)); + + /* If there is a (corresponding) variable or this is the address of a + constant, we only want to return the initializer if an lvalue isn't + required. Evaluate this now if we have not already done so. */ + if ((!constant_only || address_of_constant) && require_lvalue < 0) + require_lvalue + = lvalue_required_p (gnat_node, gnu_result_type, true, + address_of_constant, Is_Aliased (gnat_temp)); + + /* Finally retrieve the initializer if this is deemed valid. */ + if ((constant_only && !address_of_constant) || !require_lvalue) + gnu_result = DECL_INITIAL (gnu_result); + } + + /* The GNAT tree has the type of a function set to its result type, so we + adjust here. Also use the type of the result if the Etype is a subtype + that is nominally unconstrained. Likewise if this is a deferred constant + of a discriminated type whose full view can be elaborated statically, to + avoid problematic conversions to the nominal subtype. But remove any + padding from the resulting type. */ + if (TREE_CODE (TREE_TYPE (gnu_result)) == FUNCTION_TYPE + || Is_Constr_Subt_For_UN_Aliased (gnat_temp_type) + || (Ekind (gnat_temp) == E_Constant + && Present (Full_View (gnat_temp)) + && Has_Discriminants (gnat_temp_type) + && TREE_CODE (gnu_result) == CONSTRUCTOR)) + { + gnu_result_type = TREE_TYPE (gnu_result); + if (TYPE_IS_PADDING_P (gnu_result_type)) + gnu_result_type = TREE_TYPE (TYPE_FIELDS (gnu_result_type)); + } + + *gnu_result_type_p = gnu_result_type; + + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to process gnat_node, an N_Pragma. Return + any statements we generate. */ + +static tree +Pragma_to_gnu (Node_Id gnat_node) +{ + Node_Id gnat_temp; + tree gnu_result = alloc_stmt_list (); + + /* Check for (and ignore) unrecognized pragma and do nothing if we are just + annotating types. */ + if (type_annotate_only + || !Is_Pragma_Name (Chars (Pragma_Identifier (gnat_node)))) + return gnu_result; + + switch (Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node)))) + { + case Pragma_Inspection_Point: + /* Do nothing at top level: all such variables are already viewable. */ + if (global_bindings_p ()) + break; + + for (gnat_temp = First (Pragma_Argument_Associations (gnat_node)); + Present (gnat_temp); + gnat_temp = Next (gnat_temp)) + { + Node_Id gnat_expr = Expression (gnat_temp); + tree gnu_expr = gnat_to_gnu (gnat_expr); + int use_address; + enum machine_mode mode; + tree asm_constraint = NULL_TREE; +#ifdef ASM_COMMENT_START + char *comment; +#endif + + if (TREE_CODE (gnu_expr) == UNCONSTRAINED_ARRAY_REF) + gnu_expr = TREE_OPERAND (gnu_expr, 0); + + /* Use the value only if it fits into a normal register, + otherwise use the address. */ + mode = TYPE_MODE (TREE_TYPE (gnu_expr)); + use_address = ((GET_MODE_CLASS (mode) != MODE_INT + && GET_MODE_CLASS (mode) != MODE_PARTIAL_INT) + || GET_MODE_SIZE (mode) > UNITS_PER_WORD); + + if (use_address) + gnu_expr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr); + +#ifdef ASM_COMMENT_START + comment = concat (ASM_COMMENT_START, + " inspection point: ", + Get_Name_String (Chars (gnat_expr)), + use_address ? " address" : "", + " is in %0", + NULL); + asm_constraint = build_string (strlen (comment), comment); + free (comment); +#endif + gnu_expr = build5 (ASM_EXPR, void_type_node, + asm_constraint, + NULL_TREE, + tree_cons + (build_tree_list (NULL_TREE, + build_string (1, "g")), + gnu_expr, NULL_TREE), + NULL_TREE, NULL_TREE); + ASM_VOLATILE_P (gnu_expr) = 1; + set_expr_location_from_node (gnu_expr, gnat_node); + append_to_statement_list (gnu_expr, &gnu_result); + } + break; + + case Pragma_Optimize: + switch (Chars (Expression + (First (Pragma_Argument_Associations (gnat_node))))) + { + case Name_Off: + if (optimize) + post_error ("must specify -O0?", gnat_node); + break; + + case Name_Space: + if (!optimize_size) + post_error ("must specify -Os?", gnat_node); + break; + + case Name_Time: + if (!optimize) + post_error ("insufficient -O value?", gnat_node); + break; + + default: + gcc_unreachable (); + } + break; + + case Pragma_Reviewable: + if (write_symbols == NO_DEBUG) + post_error ("must specify -g?", gnat_node); + break; + } + + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to translate GNAT_NODE, an N_Attribute node, + to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to + where we should place the result type. ATTRIBUTE is the attribute ID. */ + +static tree +Attribute_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, int attribute) +{ + tree gnu_prefix, gnu_type, gnu_expr; + tree gnu_result_type, gnu_result = error_mark_node; + bool prefix_unused = false; + + /* ??? If this is an access attribute for a public subprogram to be used in + a dispatch table, do not translate its type as it's useless there and the + parameter types might be incomplete types coming from a limited with. */ + if (Ekind (Etype (gnat_node)) == E_Access_Subprogram_Type + && Is_Dispatch_Table_Entity (Etype (gnat_node)) + && Nkind (Prefix (gnat_node)) == N_Identifier + && Is_Subprogram (Entity (Prefix (gnat_node))) + && Is_Public (Entity (Prefix (gnat_node))) + && !present_gnu_tree (Entity (Prefix (gnat_node)))) + gnu_prefix = get_minimal_subprog_decl (Entity (Prefix (gnat_node))); + else + gnu_prefix = gnat_to_gnu (Prefix (gnat_node)); + gnu_type = TREE_TYPE (gnu_prefix); + + /* If the input is a NULL_EXPR, make a new one. */ + if (TREE_CODE (gnu_prefix) == NULL_EXPR) + { + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + *gnu_result_type_p = gnu_result_type; + return build1 (NULL_EXPR, gnu_result_type, TREE_OPERAND (gnu_prefix, 0)); + } + + switch (attribute) + { + case Attr_Pos: + case Attr_Val: + /* These are just conversions since representation clauses for + enumeration types are handled in the front-end. */ + { + bool checkp = Do_Range_Check (First (Expressions (gnat_node))); + gnu_result = gnat_to_gnu (First (Expressions (gnat_node))); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = convert_with_check (Etype (gnat_node), gnu_result, + checkp, checkp, true, gnat_node); + } + break; + + case Attr_Pred: + case Attr_Succ: + /* These just add or subtract the constant 1 since representation + clauses for enumeration types are handled in the front-end. */ + gnu_expr = gnat_to_gnu (First (Expressions (gnat_node))); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + if (Do_Range_Check (First (Expressions (gnat_node)))) + { + gnu_expr = gnat_protect_expr (gnu_expr); + gnu_expr + = emit_check + (build_binary_op (EQ_EXPR, boolean_type_node, + gnu_expr, + attribute == Attr_Pred + ? TYPE_MIN_VALUE (gnu_result_type) + : TYPE_MAX_VALUE (gnu_result_type)), + gnu_expr, CE_Range_Check_Failed, gnat_node); + } + + gnu_result + = build_binary_op (attribute == Attr_Pred ? MINUS_EXPR : PLUS_EXPR, + gnu_result_type, gnu_expr, + convert (gnu_result_type, integer_one_node)); + break; + + case Attr_Address: + case Attr_Unrestricted_Access: + /* Conversions don't change addresses but can cause us to miss the + COMPONENT_REF case below, so strip them off. */ + gnu_prefix = remove_conversions (gnu_prefix, + !Must_Be_Byte_Aligned (gnat_node)); + + /* If we are taking 'Address of an unconstrained object, this is the + pointer to the underlying array. */ + if (attribute == Attr_Address) + gnu_prefix = maybe_unconstrained_array (gnu_prefix); + + /* If we are building a static dispatch table, we have to honor + TARGET_VTABLE_USES_DESCRIPTORS if we want to be compatible + with the C++ ABI. We do it in the non-static case as well, + see gnat_to_gnu_entity, case E_Access_Subprogram_Type. */ + else if (TARGET_VTABLE_USES_DESCRIPTORS + && Is_Dispatch_Table_Entity (Etype (gnat_node))) + { + tree gnu_field, t; + /* Descriptors can only be built here for top-level functions. */ + bool build_descriptor = (global_bindings_p () != 0); + int i; + vec<constructor_elt, va_gc> *gnu_vec = NULL; + constructor_elt *elt; + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If we're not going to build the descriptor, we have to retrieve + the one which will be built by the linker (or by the compiler + later if a static chain is requested). */ + if (!build_descriptor) + { + gnu_result = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_prefix); + gnu_result = fold_convert (build_pointer_type (gnu_result_type), + gnu_result); + gnu_result = build1 (INDIRECT_REF, gnu_result_type, gnu_result); + } + + vec_safe_grow (gnu_vec, TARGET_VTABLE_USES_DESCRIPTORS); + elt = (gnu_vec->address () + TARGET_VTABLE_USES_DESCRIPTORS - 1); + for (gnu_field = TYPE_FIELDS (gnu_result_type), i = 0; + i < TARGET_VTABLE_USES_DESCRIPTORS; + gnu_field = DECL_CHAIN (gnu_field), i++) + { + if (build_descriptor) + { + t = build2 (FDESC_EXPR, TREE_TYPE (gnu_field), gnu_prefix, + build_int_cst (NULL_TREE, i)); + TREE_CONSTANT (t) = 1; + } + else + t = build3 (COMPONENT_REF, ptr_void_ftype, gnu_result, + gnu_field, NULL_TREE); + + elt->index = gnu_field; + elt->value = t; + elt--; + } + + gnu_result = gnat_build_constructor (gnu_result_type, gnu_vec); + break; + } + + /* ... fall through ... */ + + case Attr_Access: + case Attr_Unchecked_Access: + case Attr_Code_Address: + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result + = build_unary_op (((attribute == Attr_Address + || attribute == Attr_Unrestricted_Access) + && !Must_Be_Byte_Aligned (gnat_node)) + ? ATTR_ADDR_EXPR : ADDR_EXPR, + gnu_result_type, gnu_prefix); + + /* For 'Code_Address, find an inner ADDR_EXPR and mark it so that we + don't try to build a trampoline. */ + if (attribute == Attr_Code_Address) + { + gnu_expr = remove_conversions (gnu_result, false); + + if (TREE_CODE (gnu_expr) == ADDR_EXPR) + TREE_NO_TRAMPOLINE (gnu_expr) = TREE_CONSTANT (gnu_expr) = 1; + } + + /* For 'Access, issue an error message if the prefix is a C++ method + since it can use a special calling convention on some platforms, + which cannot be propagated to the access type. */ + else if (attribute == Attr_Access + && Nkind (Prefix (gnat_node)) == N_Identifier + && is_cplusplus_method (Entity (Prefix (gnat_node)))) + post_error ("access to C++ constructor or member function not allowed", + gnat_node); + + /* For other address attributes applied to a nested function, + find an inner ADDR_EXPR and annotate it so that we can issue + a useful warning with -Wtrampolines. */ + else if (TREE_CODE (TREE_TYPE (gnu_prefix)) == FUNCTION_TYPE) + { + gnu_expr = remove_conversions (gnu_result, false); + + if (TREE_CODE (gnu_expr) == ADDR_EXPR + && decl_function_context (TREE_OPERAND (gnu_expr, 0))) + { + set_expr_location_from_node (gnu_expr, gnat_node); + + /* Check that we're not violating the No_Implicit_Dynamic_Code + restriction. Be conservative if we don't know anything + about the trampoline strategy for the target. */ + Check_Implicit_Dynamic_Code_Allowed (gnat_node); + } + } + break; + + case Attr_Pool_Address: + { + tree gnu_ptr = gnu_prefix; + tree gnu_obj_type; + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is fat pointer, the object must have been allocated with the + template in front of the array. So compute the template address; do + it by converting to a thin pointer. */ + if (TYPE_IS_FAT_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr + = convert (build_pointer_type + (TYPE_OBJECT_RECORD_TYPE + (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (gnu_ptr)))), + gnu_ptr); + + gnu_obj_type = TREE_TYPE (TREE_TYPE (gnu_ptr)); + + /* If this is a thin pointer, the object must have been allocated with + the template in front of the array. So compute the template address + and return it. */ + if (TYPE_IS_THIN_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr + = build_binary_op (POINTER_PLUS_EXPR, TREE_TYPE (gnu_ptr), + gnu_ptr, + fold_build1 (NEGATE_EXPR, sizetype, + byte_position + (DECL_CHAIN + TYPE_FIELDS ((gnu_obj_type))))); + + gnu_result = convert (gnu_result_type, gnu_ptr); + } + break; + + case Attr_Size: + case Attr_Object_Size: + case Attr_Value_Size: + case Attr_Max_Size_In_Storage_Elements: + gnu_expr = gnu_prefix; + + /* Remove NOPs and conversions between original and packable version + from GNU_EXPR, and conversions from GNU_PREFIX. We use GNU_EXPR + to see if a COMPONENT_REF was involved. */ + while (TREE_CODE (gnu_expr) == NOP_EXPR + || (TREE_CODE (gnu_expr) == VIEW_CONVERT_EXPR + && TREE_CODE (TREE_TYPE (gnu_expr)) == RECORD_TYPE + && TREE_CODE (TREE_TYPE (TREE_OPERAND (gnu_expr, 0))) + == RECORD_TYPE + && TYPE_NAME (TREE_TYPE (gnu_expr)) + == TYPE_NAME (TREE_TYPE (TREE_OPERAND (gnu_expr, 0))))) + gnu_expr = TREE_OPERAND (gnu_expr, 0); + + gnu_prefix = remove_conversions (gnu_prefix, true); + prefix_unused = true; + gnu_type = TREE_TYPE (gnu_prefix); + + /* Replace an unconstrained array type with the type of the underlying + array. We can't do this with a call to maybe_unconstrained_array + since we may have a TYPE_DECL. For 'Max_Size_In_Storage_Elements, + use the record type that will be used to allocate the object and its + template. */ + if (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE) + { + gnu_type = TYPE_OBJECT_RECORD_TYPE (gnu_type); + if (attribute != Attr_Max_Size_In_Storage_Elements) + gnu_type = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_type))); + } + + /* If we're looking for the size of a field, return the field size. */ + if (TREE_CODE (gnu_prefix) == COMPONENT_REF) + gnu_result = DECL_SIZE (TREE_OPERAND (gnu_prefix, 1)); + + /* Otherwise, if the prefix is an object, or if we are looking for + 'Object_Size or 'Max_Size_In_Storage_Elements, the result is the + GCC size of the type. We make an exception for padded objects, + as we do not take into account alignment promotions for the size. + This is in keeping with the object case of gnat_to_gnu_entity. */ + else if ((TREE_CODE (gnu_prefix) != TYPE_DECL + && !(TYPE_IS_PADDING_P (gnu_type) + && TREE_CODE (gnu_expr) == COMPONENT_REF)) + || attribute == Attr_Object_Size + || attribute == Attr_Max_Size_In_Storage_Elements) + { + /* If this is a dereference and we have a special dynamic constrained + subtype on the prefix, use it to compute the size; otherwise, use + the designated subtype. */ + if (Nkind (Prefix (gnat_node)) == N_Explicit_Dereference) + { + Node_Id gnat_deref = Prefix (gnat_node); + Node_Id gnat_actual_subtype + = Actual_Designated_Subtype (gnat_deref); + tree gnu_ptr_type + = TREE_TYPE (gnat_to_gnu (Prefix (gnat_deref))); + + if (TYPE_IS_FAT_OR_THIN_POINTER_P (gnu_ptr_type) + && Present (gnat_actual_subtype)) + { + tree gnu_actual_obj_type + = gnat_to_gnu_type (gnat_actual_subtype); + gnu_type + = build_unc_object_type_from_ptr (gnu_ptr_type, + gnu_actual_obj_type, + get_identifier ("SIZE"), + false); + } + } + + gnu_result = TYPE_SIZE (gnu_type); + } + + /* Otherwise, the result is the RM size of the type. */ + else + gnu_result = rm_size (gnu_type); + + /* Deal with a self-referential size by returning the maximum size for + a type and by qualifying the size with the object otherwise. */ + if (CONTAINS_PLACEHOLDER_P (gnu_result)) + { + if (TREE_CODE (gnu_prefix) == TYPE_DECL) + gnu_result = max_size (gnu_result, true); + else + gnu_result = substitute_placeholder_in_expr (gnu_result, gnu_expr); + } + + /* If the type contains a template, subtract its size. */ + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_type)) + gnu_result = size_binop (MINUS_EXPR, gnu_result, + DECL_SIZE (TYPE_FIELDS (gnu_type))); + + /* For 'Max_Size_In_Storage_Elements, adjust the unit. */ + if (attribute == Attr_Max_Size_In_Storage_Elements) + gnu_result = size_binop (CEIL_DIV_EXPR, gnu_result, bitsize_unit_node); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case Attr_Alignment: + { + unsigned int align; + + if (TREE_CODE (gnu_prefix) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_prefix, 0)))) + gnu_prefix = TREE_OPERAND (gnu_prefix, 0); + + gnu_type = TREE_TYPE (gnu_prefix); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + prefix_unused = true; + + if (TREE_CODE (gnu_prefix) == COMPONENT_REF) + align = DECL_ALIGN (TREE_OPERAND (gnu_prefix, 1)) / BITS_PER_UNIT; + else + { + Node_Id gnat_prefix = Prefix (gnat_node); + Entity_Id gnat_type = Etype (gnat_prefix); + unsigned int double_align; + bool is_capped_double, align_clause; + + /* If the default alignment of "double" or larger scalar types is + specifically capped and there is an alignment clause neither + on the type nor on the prefix itself, return the cap. */ + if ((double_align = double_float_alignment) > 0) + is_capped_double + = is_double_float_or_array (gnat_type, &align_clause); + else if ((double_align = double_scalar_alignment) > 0) + is_capped_double + = is_double_scalar_or_array (gnat_type, &align_clause); + else + is_capped_double = align_clause = false; + + if (is_capped_double + && Nkind (gnat_prefix) == N_Identifier + && Present (Alignment_Clause (Entity (gnat_prefix)))) + align_clause = true; + + if (is_capped_double && !align_clause) + align = double_align; + else + align = TYPE_ALIGN (gnu_type) / BITS_PER_UNIT; + } + + gnu_result = size_int (align); + } + break; + + case Attr_First: + case Attr_Last: + case Attr_Range_Length: + prefix_unused = true; + + if (INTEGRAL_TYPE_P (gnu_type) || TREE_CODE (gnu_type) == REAL_TYPE) + { + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + if (attribute == Attr_First) + gnu_result = TYPE_MIN_VALUE (gnu_type); + else if (attribute == Attr_Last) + gnu_result = TYPE_MAX_VALUE (gnu_type); + else + gnu_result + = build_binary_op + (MAX_EXPR, get_base_type (gnu_result_type), + build_binary_op + (PLUS_EXPR, get_base_type (gnu_result_type), + build_binary_op (MINUS_EXPR, + get_base_type (gnu_result_type), + convert (gnu_result_type, + TYPE_MAX_VALUE (gnu_type)), + convert (gnu_result_type, + TYPE_MIN_VALUE (gnu_type))), + convert (gnu_result_type, integer_one_node)), + convert (gnu_result_type, integer_zero_node)); + + break; + } + + /* ... fall through ... */ + + case Attr_Length: + { + int Dimension = (Present (Expressions (gnat_node)) + ? UI_To_Int (Intval (First (Expressions (gnat_node)))) + : 1), i; + struct parm_attr_d *pa = NULL; + Entity_Id gnat_param = Empty; + + /* Make sure any implicit dereference gets done. */ + gnu_prefix = maybe_implicit_deref (gnu_prefix); + gnu_prefix = maybe_unconstrained_array (gnu_prefix); + + /* We treat unconstrained array In parameters specially. */ + if (!Is_Constrained (Etype (Prefix (gnat_node)))) + { + Node_Id gnat_prefix = Prefix (gnat_node); + + /* This is the direct case. */ + if (Nkind (gnat_prefix) == N_Identifier + && Ekind (Entity (gnat_prefix)) == E_In_Parameter) + gnat_param = Entity (gnat_prefix); + + /* This is the indirect case. Note that we need to be sure that + the access value cannot be null as we'll hoist the load. */ + if (Nkind (gnat_prefix) == N_Explicit_Dereference + && Nkind (Prefix (gnat_prefix)) == N_Identifier + && Ekind (Entity (Prefix (gnat_prefix))) == E_In_Parameter + && Can_Never_Be_Null (Entity (Prefix (gnat_prefix)))) + gnat_param = Entity (Prefix (gnat_prefix)); + } + + /* If the prefix is the view conversion of a constrained array to an + unconstrained form, we retrieve the constrained array because we + might not be able to substitute the PLACEHOLDER_EXPR coming from + the conversion. This can occur with the 'Old attribute applied + to a parameter with an unconstrained type, which gets rewritten + into a constrained local variable very late in the game. */ + if (TREE_CODE (gnu_prefix) == VIEW_CONVERT_EXPR + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (TREE_TYPE (gnu_prefix))) + && !CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (TREE_OPERAND (gnu_prefix, 0))))) + gnu_type = TREE_TYPE (TREE_OPERAND (gnu_prefix, 0)); + else + gnu_type = TREE_TYPE (gnu_prefix); + + prefix_unused = true; + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + if (TYPE_CONVENTION_FORTRAN_P (gnu_type)) + { + int ndim; + tree gnu_type_temp; + + for (ndim = 1, gnu_type_temp = gnu_type; + TREE_CODE (TREE_TYPE (gnu_type_temp)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type_temp)); + ndim++, gnu_type_temp = TREE_TYPE (gnu_type_temp)) + ; + + Dimension = ndim + 1 - Dimension; + } + + for (i = 1; i < Dimension; i++) + gnu_type = TREE_TYPE (gnu_type); + + gcc_assert (TREE_CODE (gnu_type) == ARRAY_TYPE); + + /* When not optimizing, look up the slot associated with the parameter + and the dimension in the cache and create a new one on failure. */ + if (!optimize && Present (gnat_param)) + { + FOR_EACH_VEC_SAFE_ELT (f_parm_attr_cache, i, pa) + if (pa->id == gnat_param && pa->dim == Dimension) + break; + + if (!pa) + { + pa = ggc_alloc_cleared_parm_attr_d (); + pa->id = gnat_param; + pa->dim = Dimension; + vec_safe_push (f_parm_attr_cache, pa); + } + } + + /* Return the cached expression or build a new one. */ + if (attribute == Attr_First) + { + if (pa && pa->first) + { + gnu_result = pa->first; + break; + } + + gnu_result + = TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type))); + } + + else if (attribute == Attr_Last) + { + if (pa && pa->last) + { + gnu_result = pa->last; + break; + } + + gnu_result + = TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type))); + } + + else /* attribute == Attr_Range_Length || attribute == Attr_Length */ + { + if (pa && pa->length) + { + gnu_result = pa->length; + break; + } + else + { + /* We used to compute the length as max (hb - lb + 1, 0), + which could overflow for some cases of empty arrays, e.g. + when lb == index_type'first. We now compute the length as + (hb >= lb) ? hb - lb + 1 : 0, which would only overflow in + much rarer cases, for extremely large arrays we expect + never to encounter in practice. In addition, the former + computation required the use of potentially constraining + signed arithmetic while the latter doesn't. Note that + the comparison must be done in the original index type, + to avoid any overflow during the conversion. */ + tree comp_type = get_base_type (gnu_result_type); + tree index_type = TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type)); + tree lb = TYPE_MIN_VALUE (index_type); + tree hb = TYPE_MAX_VALUE (index_type); + gnu_result + = build_binary_op (PLUS_EXPR, comp_type, + build_binary_op (MINUS_EXPR, + comp_type, + convert (comp_type, hb), + convert (comp_type, lb)), + convert (comp_type, integer_one_node)); + gnu_result + = build_cond_expr (comp_type, + build_binary_op (GE_EXPR, + boolean_type_node, + hb, lb), + gnu_result, + convert (comp_type, integer_zero_node)); + } + } + + /* If this has a PLACEHOLDER_EXPR, qualify it by the object we are + handling. Note that these attributes could not have been used on + an unconstrained array type. */ + gnu_result = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_result, gnu_prefix); + + /* Cache the expression we have just computed. Since we want to do it + at run time, we force the use of a SAVE_EXPR and let the gimplifier + create the temporary in the outermost binding level. We will make + sure in Subprogram_Body_to_gnu that it is evaluated on all possible + paths by forcing its evaluation on entry of the function. */ + if (pa) + { + gnu_result + = build1 (SAVE_EXPR, TREE_TYPE (gnu_result), gnu_result); + if (attribute == Attr_First) + pa->first = gnu_result; + else if (attribute == Attr_Last) + pa->last = gnu_result; + else + pa->length = gnu_result; + } + + /* Set the source location onto the predicate of the condition in the + 'Length case but do not do it if the expression is cached to avoid + messing up the debug info. */ + else if ((attribute == Attr_Range_Length || attribute == Attr_Length) + && TREE_CODE (gnu_result) == COND_EXPR + && EXPR_P (TREE_OPERAND (gnu_result, 0))) + set_expr_location_from_node (TREE_OPERAND (gnu_result, 0), + gnat_node); + + break; + } + + case Attr_Bit_Position: + case Attr_Position: + case Attr_First_Bit: + case Attr_Last_Bit: + case Attr_Bit: + { + HOST_WIDE_INT bitsize; + HOST_WIDE_INT bitpos; + tree gnu_offset; + tree gnu_field_bitpos; + tree gnu_field_offset; + tree gnu_inner; + enum machine_mode mode; + int unsignedp, volatilep; + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_prefix = remove_conversions (gnu_prefix, true); + prefix_unused = true; + + /* We can have 'Bit on any object, but if it isn't a COMPONENT_REF, + the result is 0. Don't allow 'Bit on a bare component, though. */ + if (attribute == Attr_Bit + && TREE_CODE (gnu_prefix) != COMPONENT_REF + && TREE_CODE (gnu_prefix) != FIELD_DECL) + { + gnu_result = integer_zero_node; + break; + } + + else + gcc_assert (TREE_CODE (gnu_prefix) == COMPONENT_REF + || (attribute == Attr_Bit_Position + && TREE_CODE (gnu_prefix) == FIELD_DECL)); + + get_inner_reference (gnu_prefix, &bitsize, &bitpos, &gnu_offset, + &mode, &unsignedp, &volatilep, false); + + if (TREE_CODE (gnu_prefix) == COMPONENT_REF) + { + gnu_field_bitpos = bit_position (TREE_OPERAND (gnu_prefix, 1)); + gnu_field_offset = byte_position (TREE_OPERAND (gnu_prefix, 1)); + + for (gnu_inner = TREE_OPERAND (gnu_prefix, 0); + TREE_CODE (gnu_inner) == COMPONENT_REF + && DECL_INTERNAL_P (TREE_OPERAND (gnu_inner, 1)); + gnu_inner = TREE_OPERAND (gnu_inner, 0)) + { + gnu_field_bitpos + = size_binop (PLUS_EXPR, gnu_field_bitpos, + bit_position (TREE_OPERAND (gnu_inner, 1))); + gnu_field_offset + = size_binop (PLUS_EXPR, gnu_field_offset, + byte_position (TREE_OPERAND (gnu_inner, 1))); + } + } + else if (TREE_CODE (gnu_prefix) == FIELD_DECL) + { + gnu_field_bitpos = bit_position (gnu_prefix); + gnu_field_offset = byte_position (gnu_prefix); + } + else + { + gnu_field_bitpos = bitsize_zero_node; + gnu_field_offset = size_zero_node; + } + + switch (attribute) + { + case Attr_Position: + gnu_result = gnu_field_offset; + break; + + case Attr_First_Bit: + case Attr_Bit: + gnu_result = size_int (bitpos % BITS_PER_UNIT); + break; + + case Attr_Last_Bit: + gnu_result = bitsize_int (bitpos % BITS_PER_UNIT); + gnu_result = size_binop (PLUS_EXPR, gnu_result, + TYPE_SIZE (TREE_TYPE (gnu_prefix))); + /* ??? Avoid a large unsigned result that will overflow when + converted to the signed universal_integer. */ + if (integer_zerop (gnu_result)) + gnu_result = integer_minus_one_node; + else + gnu_result + = size_binop (MINUS_EXPR, gnu_result, bitsize_one_node); + break; + + case Attr_Bit_Position: + gnu_result = gnu_field_bitpos; + break; + } + + /* If this has a PLACEHOLDER_EXPR, qualify it by the object we are + handling. */ + gnu_result = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_result, gnu_prefix); + break; + } + + case Attr_Min: + case Attr_Max: + { + tree gnu_lhs = gnat_to_gnu (First (Expressions (gnat_node))); + tree gnu_rhs = gnat_to_gnu (Next (First (Expressions (gnat_node)))); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = build_binary_op (attribute == Attr_Min + ? MIN_EXPR : MAX_EXPR, + gnu_result_type, gnu_lhs, gnu_rhs); + } + break; + + case Attr_Passed_By_Reference: + gnu_result = size_int (default_pass_by_ref (gnu_type) + || must_pass_by_ref (gnu_type)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case Attr_Component_Size: + if (TREE_CODE (gnu_prefix) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_prefix, 0)))) + gnu_prefix = TREE_OPERAND (gnu_prefix, 0); + + gnu_prefix = maybe_implicit_deref (gnu_prefix); + gnu_type = TREE_TYPE (gnu_prefix); + + if (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_type)))); + + while (TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type))) + gnu_type = TREE_TYPE (gnu_type); + + gcc_assert (TREE_CODE (gnu_type) == ARRAY_TYPE); + + /* Note this size cannot be self-referential. */ + gnu_result = TYPE_SIZE (TREE_TYPE (gnu_type)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + prefix_unused = true; + break; + + case Attr_Descriptor_Size: + gnu_type = TREE_TYPE (gnu_prefix); + gcc_assert (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE); + + /* What we want is the offset of the ARRAY field in the record + that the thin pointer designates. */ + gnu_type = TYPE_OBJECT_RECORD_TYPE (gnu_type); + gnu_result = bit_position (DECL_CHAIN (TYPE_FIELDS (gnu_type))); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + prefix_unused = true; + break; + + case Attr_Null_Parameter: + /* This is just a zero cast to the pointer type for our prefix and + dereferenced. */ + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result + = build_unary_op (INDIRECT_REF, NULL_TREE, + convert (build_pointer_type (gnu_result_type), + integer_zero_node)); + TREE_PRIVATE (gnu_result) = 1; + break; + + case Attr_Mechanism_Code: + { + int code; + Entity_Id gnat_obj = Entity (Prefix (gnat_node)); + + prefix_unused = true; + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + if (Present (Expressions (gnat_node))) + { + int i = UI_To_Int (Intval (First (Expressions (gnat_node)))); + + for (gnat_obj = First_Formal (gnat_obj); i > 1; + i--, gnat_obj = Next_Formal (gnat_obj)) + ; + } + + code = Mechanism (gnat_obj); + if (code == Default) + code = ((present_gnu_tree (gnat_obj) + && (DECL_BY_REF_P (get_gnu_tree (gnat_obj)) + || ((TREE_CODE (get_gnu_tree (gnat_obj)) + == PARM_DECL) + && (DECL_BY_COMPONENT_PTR_P + (get_gnu_tree (gnat_obj)))))) + ? By_Reference : By_Copy); + gnu_result = convert (gnu_result_type, size_int (- code)); + } + break; + + default: + /* This abort means that we have an unimplemented attribute. */ + gcc_unreachable (); + } + + /* If this is an attribute where the prefix was unused, force a use of it if + it has a side-effect. But don't do it if the prefix is just an entity + name. However, if an access check is needed, we must do it. See second + example in AARM 11.6(5.e). */ + if (prefix_unused && TREE_SIDE_EFFECTS (gnu_prefix) + && !Is_Entity_Name (Prefix (gnat_node))) + gnu_result = build_compound_expr (TREE_TYPE (gnu_result), gnu_prefix, + gnu_result); + + *gnu_result_type_p = gnu_result_type; + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Case_Statement, + to a GCC tree, which is returned. */ + +static tree +Case_Statement_to_gnu (Node_Id gnat_node) +{ + tree gnu_result, gnu_expr, gnu_label; + Node_Id gnat_when; + location_t end_locus; + bool may_fallthru = false; + + gnu_expr = gnat_to_gnu (Expression (gnat_node)); + gnu_expr = convert (get_base_type (TREE_TYPE (gnu_expr)), gnu_expr); + + /* The range of values in a case statement is determined by the rules in + RM 5.4(7-9). In almost all cases, this range is represented by the Etype + of the expression. One exception arises in the case of a simple name that + is parenthesized. This still has the Etype of the name, but since it is + not a name, para 7 does not apply, and we need to go to the base type. + This is the only case where parenthesization affects the dynamic + semantics (i.e. the range of possible values at run time that is covered + by the others alternative). + + Another exception is if the subtype of the expression is non-static. In + that case, we also have to use the base type. */ + if (Paren_Count (Expression (gnat_node)) != 0 + || !Is_OK_Static_Subtype (Underlying_Type + (Etype (Expression (gnat_node))))) + gnu_expr = convert (get_base_type (TREE_TYPE (gnu_expr)), gnu_expr); + + /* We build a SWITCH_EXPR that contains the code with interspersed + CASE_LABEL_EXPRs for each label. */ + if (!Sloc_to_locus (Sloc (gnat_node) + UI_To_Int (End_Span (gnat_node)), + &end_locus)) + end_locus = input_location; + gnu_label = create_artificial_label (end_locus); + start_stmt_group (); + + for (gnat_when = First_Non_Pragma (Alternatives (gnat_node)); + Present (gnat_when); + gnat_when = Next_Non_Pragma (gnat_when)) + { + bool choices_added_p = false; + Node_Id gnat_choice; + + /* First compile all the different case choices for the current WHEN + alternative. */ + for (gnat_choice = First (Discrete_Choices (gnat_when)); + Present (gnat_choice); gnat_choice = Next (gnat_choice)) + { + tree gnu_low = NULL_TREE, gnu_high = NULL_TREE; + + switch (Nkind (gnat_choice)) + { + case N_Range: + gnu_low = gnat_to_gnu (Low_Bound (gnat_choice)); + gnu_high = gnat_to_gnu (High_Bound (gnat_choice)); + break; + + case N_Subtype_Indication: + gnu_low = gnat_to_gnu (Low_Bound (Range_Expression + (Constraint (gnat_choice)))); + gnu_high = gnat_to_gnu (High_Bound (Range_Expression + (Constraint (gnat_choice)))); + break; + + case N_Identifier: + case N_Expanded_Name: + /* This represents either a subtype range or a static value of + some kind; Ekind says which. */ + if (IN (Ekind (Entity (gnat_choice)), Type_Kind)) + { + tree gnu_type = get_unpadded_type (Entity (gnat_choice)); + + gnu_low = fold (TYPE_MIN_VALUE (gnu_type)); + gnu_high = fold (TYPE_MAX_VALUE (gnu_type)); + break; + } + + /* ... fall through ... */ + + case N_Character_Literal: + case N_Integer_Literal: + gnu_low = gnat_to_gnu (gnat_choice); + break; + + case N_Others_Choice: + break; + + default: + gcc_unreachable (); + } + + /* If the case value is a subtype that raises Constraint_Error at + run time because of a wrong bound, then gnu_low or gnu_high is + not translated into an INTEGER_CST. In such a case, we need + to ensure that the when statement is not added in the tree, + otherwise it will crash the gimplifier. */ + if ((!gnu_low || TREE_CODE (gnu_low) == INTEGER_CST) + && (!gnu_high || TREE_CODE (gnu_high) == INTEGER_CST)) + { + add_stmt_with_node (build_case_label + (gnu_low, gnu_high, + create_artificial_label (input_location)), + gnat_choice); + choices_added_p = true; + } + } + + /* Push a binding level here in case variables are declared as we want + them to be local to this set of statements instead of to the block + containing the Case statement. */ + if (choices_added_p) + { + tree group = build_stmt_group (Statements (gnat_when), true); + bool group_may_fallthru = block_may_fallthru (group); + add_stmt (group); + if (group_may_fallthru) + { + tree stmt = build1 (GOTO_EXPR, void_type_node, gnu_label); + SET_EXPR_LOCATION (stmt, end_locus); + add_stmt (stmt); + may_fallthru = true; + } + } + } + + /* Now emit a definition of the label the cases branch to, if any. */ + if (may_fallthru) + add_stmt (build1 (LABEL_EXPR, void_type_node, gnu_label)); + gnu_result = build3 (SWITCH_EXPR, TREE_TYPE (gnu_expr), gnu_expr, + end_stmt_group (), NULL_TREE); + + return gnu_result; +} + +/* Find out whether VAR is an iteration variable of an enclosing loop in the + current function. If so, push a range_check_info structure onto the stack + of this enclosing loop and return it. Otherwise, return NULL. */ + +static struct range_check_info_d * +push_range_check_info (tree var) +{ + struct loop_info_d *iter = NULL; + unsigned int i; + + if (vec_safe_is_empty (gnu_loop_stack)) + return NULL; + + var = remove_conversions (var, false); + + if (TREE_CODE (var) != VAR_DECL) + return NULL; + + if (decl_function_context (var) != current_function_decl) + return NULL; + + for (i = vec_safe_length (gnu_loop_stack) - 1; + vec_safe_iterate (gnu_loop_stack, i, &iter); + i--) + if (var == iter->loop_var) + break; + + if (iter) + { + struct range_check_info_d *rci = ggc_alloc_range_check_info_d (); + vec_safe_push (iter->checks, rci); + return rci; + } + + return NULL; +} + +/* Return true if VAL (of type TYPE) can equal the minimum value if MAX is + false, or the maximum value if MAX is true, of TYPE. */ + +static bool +can_equal_min_or_max_val_p (tree val, tree type, bool max) +{ + tree min_or_max_val = (max ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type)); + + if (TREE_CODE (min_or_max_val) != INTEGER_CST) + return true; + + if (TREE_CODE (val) == NOP_EXPR) + val = (max + ? TYPE_MAX_VALUE (TREE_TYPE (TREE_OPERAND (val, 0))) + : TYPE_MIN_VALUE (TREE_TYPE (TREE_OPERAND (val, 0)))); + + if (TREE_CODE (val) != INTEGER_CST) + return true; + + return tree_int_cst_equal (val, min_or_max_val) == 1; +} + +/* Return true if VAL (of type TYPE) can equal the minimum value of TYPE. + If REVERSE is true, minimum value is taken as maximum value. */ + +static inline bool +can_equal_min_val_p (tree val, tree type, bool reverse) +{ + return can_equal_min_or_max_val_p (val, type, reverse); +} + +/* Return true if VAL (of type TYPE) can equal the maximum value of TYPE. + If REVERSE is true, maximum value is taken as minimum value. */ + +static inline bool +can_equal_max_val_p (tree val, tree type, bool reverse) +{ + return can_equal_min_or_max_val_p (val, type, !reverse); +} + +/* Return true if VAL1 can be lower than VAL2. */ + +static bool +can_be_lower_p (tree val1, tree val2) +{ + if (TREE_CODE (val1) == NOP_EXPR) + val1 = TYPE_MIN_VALUE (TREE_TYPE (TREE_OPERAND (val1, 0))); + + if (TREE_CODE (val1) != INTEGER_CST) + return true; + + if (TREE_CODE (val2) == NOP_EXPR) + val2 = TYPE_MAX_VALUE (TREE_TYPE (TREE_OPERAND (val2, 0))); + + if (TREE_CODE (val2) != INTEGER_CST) + return true; + + return tree_int_cst_lt (val1, val2); +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Loop_Statement, + to a GCC tree, which is returned. */ + +static tree +Loop_Statement_to_gnu (Node_Id gnat_node) +{ + const Node_Id gnat_iter_scheme = Iteration_Scheme (gnat_node); + struct loop_info_d *gnu_loop_info = ggc_alloc_cleared_loop_info_d (); + tree gnu_loop_stmt = build4 (LOOP_STMT, void_type_node, NULL_TREE, + NULL_TREE, NULL_TREE, NULL_TREE); + tree gnu_loop_label = create_artificial_label (input_location); + tree gnu_cond_expr = NULL_TREE, gnu_low = NULL_TREE, gnu_high = NULL_TREE; + tree gnu_result; + + /* Push the loop_info structure associated with the LOOP_STMT. */ + vec_safe_push (gnu_loop_stack, gnu_loop_info); + + /* Set location information for statement and end label. */ + set_expr_location_from_node (gnu_loop_stmt, gnat_node); + Sloc_to_locus (Sloc (End_Label (gnat_node)), + &DECL_SOURCE_LOCATION (gnu_loop_label)); + LOOP_STMT_LABEL (gnu_loop_stmt) = gnu_loop_label; + + /* Save the label so that a corresponding N_Exit_Statement can find it. */ + gnu_loop_info->label = gnu_loop_label; + + /* Set the condition under which the loop must keep going. + For the case "LOOP .... END LOOP;" the condition is always true. */ + if (No (gnat_iter_scheme)) + ; + + /* For the case "WHILE condition LOOP ..... END LOOP;" it's immediate. */ + else if (Present (Condition (gnat_iter_scheme))) + LOOP_STMT_COND (gnu_loop_stmt) + = gnat_to_gnu (Condition (gnat_iter_scheme)); + + /* Otherwise we have an iteration scheme and the condition is given by the + bounds of the subtype of the iteration variable. */ + else + { + Node_Id gnat_loop_spec = Loop_Parameter_Specification (gnat_iter_scheme); + Entity_Id gnat_loop_var = Defining_Entity (gnat_loop_spec); + Entity_Id gnat_type = Etype (gnat_loop_var); + tree gnu_type = get_unpadded_type (gnat_type); + tree gnu_base_type = get_base_type (gnu_type); + tree gnu_one_node = convert (gnu_base_type, integer_one_node); + tree gnu_loop_var, gnu_loop_iv, gnu_first, gnu_last, gnu_stmt; + enum tree_code update_code, test_code, shift_code; + bool reverse = Reverse_Present (gnat_loop_spec), use_iv = false; + + gnu_low = TYPE_MIN_VALUE (gnu_type); + gnu_high = TYPE_MAX_VALUE (gnu_type); + + /* We must disable modulo reduction for the iteration variable, if any, + in order for the loop comparison to be effective. */ + if (reverse) + { + gnu_first = gnu_high; + gnu_last = gnu_low; + update_code = MINUS_NOMOD_EXPR; + test_code = GE_EXPR; + shift_code = PLUS_NOMOD_EXPR; + } + else + { + gnu_first = gnu_low; + gnu_last = gnu_high; + update_code = PLUS_NOMOD_EXPR; + test_code = LE_EXPR; + shift_code = MINUS_NOMOD_EXPR; + } + + /* We use two different strategies to translate the loop, depending on + whether optimization is enabled. + + If it is, we generate the canonical loop form expected by the loop + optimizer and the loop vectorizer, which is the do-while form: + + ENTRY_COND + loop: + TOP_UPDATE + BODY + BOTTOM_COND + GOTO loop + + This avoids an implicit dependency on loop header copying and makes + it possible to turn BOTTOM_COND into an inequality test. + + If optimization is disabled, loop header copying doesn't come into + play and we try to generate the loop form with the fewer conditional + branches. First, the default form, which is: + + loop: + TOP_COND + BODY + BOTTOM_UPDATE + GOTO loop + + It should catch most loops with constant ending point. Then, if we + cannot, we try to generate the shifted form: + + loop: + TOP_COND + TOP_UPDATE + BODY + GOTO loop + + which should catch loops with constant starting point. Otherwise, if + we cannot, we generate the fallback form: + + ENTRY_COND + loop: + BODY + BOTTOM_COND + BOTTOM_UPDATE + GOTO loop + + which works in all cases. */ + + if (optimize) + { + /* We can use the do-while form directly if GNU_FIRST-1 doesn't + overflow. */ + if (!can_equal_min_val_p (gnu_first, gnu_base_type, reverse)) + ; + + /* Otherwise, use the do-while form with the help of a special + induction variable in the unsigned version of the base type + or the unsigned version of the size type, whichever is the + largest, in order to have wrap-around arithmetics for it. */ + else + { + if (TYPE_PRECISION (gnu_base_type) + > TYPE_PRECISION (size_type_node)) + gnu_base_type + = gnat_type_for_size (TYPE_PRECISION (gnu_base_type), 1); + else + gnu_base_type = size_type_node; + + gnu_first = convert (gnu_base_type, gnu_first); + gnu_last = convert (gnu_base_type, gnu_last); + gnu_one_node = convert (gnu_base_type, integer_one_node); + use_iv = true; + } + + gnu_first + = build_binary_op (shift_code, gnu_base_type, gnu_first, + gnu_one_node); + LOOP_STMT_TOP_UPDATE_P (gnu_loop_stmt) = 1; + LOOP_STMT_BOTTOM_COND_P (gnu_loop_stmt) = 1; + } + else + { + /* We can use the default form if GNU_LAST+1 doesn't overflow. */ + if (!can_equal_max_val_p (gnu_last, gnu_base_type, reverse)) + ; + + /* Otherwise, we can use the shifted form if neither GNU_FIRST-1 nor + GNU_LAST-1 does. */ + else if (!can_equal_min_val_p (gnu_first, gnu_base_type, reverse) + && !can_equal_min_val_p (gnu_last, gnu_base_type, reverse)) + { + gnu_first + = build_binary_op (shift_code, gnu_base_type, gnu_first, + gnu_one_node); + gnu_last + = build_binary_op (shift_code, gnu_base_type, gnu_last, + gnu_one_node); + LOOP_STMT_TOP_UPDATE_P (gnu_loop_stmt) = 1; + } + + /* Otherwise, use the fallback form. */ + else + LOOP_STMT_BOTTOM_COND_P (gnu_loop_stmt) = 1; + } + + /* If we use the BOTTOM_COND, we can turn the test into an inequality + test but we may have to add ENTRY_COND to protect the empty loop. */ + if (LOOP_STMT_BOTTOM_COND_P (gnu_loop_stmt)) + { + test_code = NE_EXPR; + if (can_be_lower_p (gnu_high, gnu_low)) + { + gnu_cond_expr + = build3 (COND_EXPR, void_type_node, + build_binary_op (LE_EXPR, boolean_type_node, + gnu_low, gnu_high), + NULL_TREE, alloc_stmt_list ()); + set_expr_location_from_node (gnu_cond_expr, gnat_loop_spec); + } + } + + /* Open a new nesting level that will surround the loop to declare the + iteration variable. */ + start_stmt_group (); + gnat_pushlevel (); + + /* If we use the special induction variable, create it and set it to + its initial value. Morever, the regular iteration variable cannot + itself be initialized, lest the initial value wrapped around. */ + if (use_iv) + { + gnu_loop_iv + = create_init_temporary ("I", gnu_first, &gnu_stmt, gnat_loop_var); + add_stmt (gnu_stmt); + gnu_first = NULL_TREE; + } + else + gnu_loop_iv = NULL_TREE; + + /* Declare the iteration variable and set it to its initial value. */ + gnu_loop_var = gnat_to_gnu_entity (gnat_loop_var, gnu_first, 1); + if (DECL_BY_REF_P (gnu_loop_var)) + gnu_loop_var = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_loop_var); + else if (use_iv) + { + gcc_assert (DECL_LOOP_PARM_P (gnu_loop_var)); + SET_DECL_INDUCTION_VAR (gnu_loop_var, gnu_loop_iv); + } + gnu_loop_info->loop_var = gnu_loop_var; + + /* Do all the arithmetics in the base type. */ + gnu_loop_var = convert (gnu_base_type, gnu_loop_var); + + /* Set either the top or bottom exit condition. */ + if (use_iv) + LOOP_STMT_COND (gnu_loop_stmt) + = build_binary_op (test_code, boolean_type_node, gnu_loop_iv, + gnu_last); + else + LOOP_STMT_COND (gnu_loop_stmt) + = build_binary_op (test_code, boolean_type_node, gnu_loop_var, + gnu_last); + + /* Set either the top or bottom update statement and give it the source + location of the iteration for better coverage info. */ + if (use_iv) + { + gnu_stmt + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_loop_iv, + build_binary_op (update_code, gnu_base_type, + gnu_loop_iv, gnu_one_node)); + set_expr_location_from_node (gnu_stmt, gnat_iter_scheme); + append_to_statement_list (gnu_stmt, + &LOOP_STMT_UPDATE (gnu_loop_stmt)); + gnu_stmt + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_loop_var, + gnu_loop_iv); + set_expr_location_from_node (gnu_stmt, gnat_iter_scheme); + append_to_statement_list (gnu_stmt, + &LOOP_STMT_UPDATE (gnu_loop_stmt)); + } + else + { + gnu_stmt + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_loop_var, + build_binary_op (update_code, gnu_base_type, + gnu_loop_var, gnu_one_node)); + set_expr_location_from_node (gnu_stmt, gnat_iter_scheme); + LOOP_STMT_UPDATE (gnu_loop_stmt) = gnu_stmt; + } + } + + /* If the loop was named, have the name point to this loop. In this case, + the association is not a DECL node, but the end label of the loop. */ + if (Present (Identifier (gnat_node))) + save_gnu_tree (Entity (Identifier (gnat_node)), gnu_loop_label, true); + + /* Make the loop body into its own block, so any allocated storage will be + released every iteration. This is needed for stack allocation. */ + LOOP_STMT_BODY (gnu_loop_stmt) + = build_stmt_group (Statements (gnat_node), true); + TREE_SIDE_EFFECTS (gnu_loop_stmt) = 1; + + /* If we have an iteration scheme, then we are in a statement group. Add + the LOOP_STMT to it, finish it and make it the "loop". */ + if (Present (gnat_iter_scheme) && No (Condition (gnat_iter_scheme))) + { + struct range_check_info_d *rci; + unsigned n_checks = vec_safe_length (gnu_loop_info->checks); + unsigned int i; + + /* First, if we have computed a small number of invariant conditions for + range checks applied to the iteration variable, then initialize these + conditions in front of the loop. Otherwise, leave them set to True. + + ??? The heuristics need to be improved, by taking into account the + following datapoints: + - loop unswitching is disabled for big loops. The cap is the + parameter PARAM_MAX_UNSWITCH_INSNS (50). + - loop unswitching can only be applied a small number of times + to a given loop. The cap is PARAM_MAX_UNSWITCH_LEVEL (3). + - the front-end quickly generates useless or redundant checks + that can be entirely optimized away in the end. */ + if (1 <= n_checks && n_checks <= 4) + for (i = 0; + vec_safe_iterate (gnu_loop_info->checks, i, &rci); + i++) + { + tree low_ok + = rci->low_bound + ? build_binary_op (GE_EXPR, boolean_type_node, + convert (rci->type, gnu_low), + rci->low_bound) + : boolean_true_node; + + tree high_ok + = rci->high_bound + ? build_binary_op (LE_EXPR, boolean_type_node, + convert (rci->type, gnu_high), + rci->high_bound) + : boolean_true_node; + + tree range_ok + = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node, + low_ok, high_ok); + + TREE_OPERAND (rci->invariant_cond, 0) + = build_unary_op (TRUTH_NOT_EXPR, boolean_type_node, range_ok); + + add_stmt_with_node_force (rci->invariant_cond, gnat_node); + } + + add_stmt (gnu_loop_stmt); + gnat_poplevel (); + gnu_loop_stmt = end_stmt_group (); + } + + /* If we have an outer COND_EXPR, that's our result and this loop is its + "true" statement. Otherwise, the result is the LOOP_STMT. */ + if (gnu_cond_expr) + { + COND_EXPR_THEN (gnu_cond_expr) = gnu_loop_stmt; + gnu_result = gnu_cond_expr; + recalculate_side_effects (gnu_cond_expr); + } + else + gnu_result = gnu_loop_stmt; + + gnu_loop_stack->pop (); + + return gnu_result; +} + +/* Emit statements to establish __gnat_handle_vms_condition as a VMS condition + handler for the current function. */ + +/* This is implemented by issuing a call to the appropriate VMS specific + builtin. To avoid having VMS specific sections in the global gigi decls + array, we maintain the decls of interest here. We can't declare them + inside the function because we must mark them never to be GC'd, which we + can only do at the global level. */ + +static GTY(()) tree vms_builtin_establish_handler_decl = NULL_TREE; +static GTY(()) tree gnat_vms_condition_handler_decl = NULL_TREE; + +static void +establish_gnat_vms_condition_handler (void) +{ + tree establish_stmt; + + /* Elaborate the required decls on the first call. Check on the decl for + the gnat condition handler to decide, as this is one we create so we are + sure that it will be non null on subsequent calls. The builtin decl is + looked up so remains null on targets where it is not implemented yet. */ + if (gnat_vms_condition_handler_decl == NULL_TREE) + { + vms_builtin_establish_handler_decl + = builtin_decl_for + (get_identifier ("__builtin_establish_vms_condition_handler")); + + gnat_vms_condition_handler_decl + = create_subprog_decl (get_identifier ("__gnat_handle_vms_condition"), + NULL_TREE, + build_function_type_list (boolean_type_node, + ptr_void_type_node, + ptr_void_type_node, + NULL_TREE), + NULL_TREE, false, true, true, true, NULL, + Empty); + + /* ??? DECL_CONTEXT shouldn't have been set because of DECL_EXTERNAL. */ + DECL_CONTEXT (gnat_vms_condition_handler_decl) = NULL_TREE; + } + + /* Do nothing if the establish builtin is not available, which might happen + on targets where the facility is not implemented. */ + if (vms_builtin_establish_handler_decl == NULL_TREE) + return; + + establish_stmt + = build_call_n_expr (vms_builtin_establish_handler_decl, 1, + build_unary_op + (ADDR_EXPR, NULL_TREE, + gnat_vms_condition_handler_decl)); + + add_stmt (establish_stmt); +} + +/* This page implements a form of Named Return Value optimization modelled + on the C++ optimization of the same name. The main difference is that + we disregard any semantical considerations when applying it here, the + counterpart being that we don't try to apply it to semantically loaded + return types, i.e. types with the TYPE_BY_REFERENCE_P flag set. + + We consider a function body of the following GENERIC form: + + return_type R1; + [...] + RETURN_EXPR [<retval> = ...] + [...] + RETURN_EXPR [<retval> = R1] + [...] + return_type Ri; + [...] + RETURN_EXPR [<retval> = ...] + [...] + RETURN_EXPR [<retval> = Ri] + [...] + + and we try to fulfill a simple criterion that would make it possible to + replace one or several Ri variables with the RESULT_DECL of the function. + + The first observation is that RETURN_EXPRs that don't directly reference + any of the Ri variables on the RHS of their assignment are transparent wrt + the optimization. This is because the Ri variables aren't addressable so + any transformation applied to them doesn't affect the RHS; moreover, the + assignment writes the full <retval> object so existing values are entirely + discarded. + + This property can be extended to some forms of RETURN_EXPRs that reference + the Ri variables, for example CONSTRUCTORs, but isn't true in the general + case, in particular when function calls are involved. + + Therefore the algorithm is as follows: + + 1. Collect the list of candidates for a Named Return Value (Ri variables + on the RHS of assignments of RETURN_EXPRs) as well as the list of the + other expressions on the RHS of such assignments. + + 2. Prune the members of the first list (candidates) that are referenced + by a member of the second list (expressions). + + 3. Extract a set of candidates with non-overlapping live ranges from the + first list. These are the Named Return Values. + + 4. Adjust the relevant RETURN_EXPRs and replace the occurrences of the + Named Return Values in the function with the RESULT_DECL. + + If the function returns an unconstrained type, things are a bit different + because the anonymous return object is allocated on the secondary stack + and RESULT_DECL is only a pointer to it. Each return object can be of a + different size and is allocated separately so we need not care about the + aforementioned overlapping issues. Therefore, we don't collect the other + expressions and skip step #2 in the algorithm. */ + +struct nrv_data +{ + bitmap nrv; + tree result; + Node_Id gnat_ret; + struct pointer_set_t *visited; +}; + +/* Return true if T is a Named Return Value. */ + +static inline bool +is_nrv_p (bitmap nrv, tree t) +{ + return TREE_CODE (t) == VAR_DECL && bitmap_bit_p (nrv, DECL_UID (t)); +} + +/* Helper function for walk_tree, used by finalize_nrv below. */ + +static tree +prune_nrv_r (tree *tp, int *walk_subtrees, void *data) +{ + struct nrv_data *dp = (struct nrv_data *)data; + tree t = *tp; + + /* No need to walk into types or decls. */ + if (IS_TYPE_OR_DECL_P (t)) + *walk_subtrees = 0; + + if (is_nrv_p (dp->nrv, t)) + bitmap_clear_bit (dp->nrv, DECL_UID (t)); + + return NULL_TREE; +} + +/* Prune Named Return Values in BLOCK and return true if there is still a + Named Return Value in BLOCK or one of its sub-blocks. */ + +static bool +prune_nrv_in_block (bitmap nrv, tree block) +{ + bool has_nrv = false; + tree t; + + /* First recurse on the sub-blocks. */ + for (t = BLOCK_SUBBLOCKS (block); t; t = BLOCK_CHAIN (t)) + has_nrv |= prune_nrv_in_block (nrv, t); + + /* Then make sure to keep at most one NRV per block. */ + for (t = BLOCK_VARS (block); t; t = DECL_CHAIN (t)) + if (is_nrv_p (nrv, t)) + { + if (has_nrv) + bitmap_clear_bit (nrv, DECL_UID (t)); + else + has_nrv = true; + } + + return has_nrv; +} + +/* Helper function for walk_tree, used by finalize_nrv below. */ + +static tree +finalize_nrv_r (tree *tp, int *walk_subtrees, void *data) +{ + struct nrv_data *dp = (struct nrv_data *)data; + tree t = *tp; + + /* No need to walk into types. */ + if (TYPE_P (t)) + *walk_subtrees = 0; + + /* Change RETURN_EXPRs of NRVs to just refer to the RESULT_DECL; this is a + nop, but differs from using NULL_TREE in that it indicates that we care + about the value of the RESULT_DECL. */ + else if (TREE_CODE (t) == RETURN_EXPR + && TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR) + { + tree ret_val = TREE_OPERAND (TREE_OPERAND (t, 0), 1), init_expr; + + /* If this is the temporary created for a return value with variable + size in Call_to_gnu, we replace the RHS with the init expression. */ + if (TREE_CODE (ret_val) == COMPOUND_EXPR + && TREE_CODE (TREE_OPERAND (ret_val, 0)) == INIT_EXPR + && TREE_OPERAND (TREE_OPERAND (ret_val, 0), 0) + == TREE_OPERAND (ret_val, 1)) + { + init_expr = TREE_OPERAND (TREE_OPERAND (ret_val, 0), 1); + ret_val = TREE_OPERAND (ret_val, 1); + } + else + init_expr = NULL_TREE; + + /* Strip useless conversions around the return value. */ + if (gnat_useless_type_conversion (ret_val)) + ret_val = TREE_OPERAND (ret_val, 0); + + if (is_nrv_p (dp->nrv, ret_val)) + { + if (init_expr) + TREE_OPERAND (TREE_OPERAND (t, 0), 1) = init_expr; + else + TREE_OPERAND (t, 0) = dp->result; + } + } + + /* Replace the DECL_EXPR of NRVs with an initialization of the RESULT_DECL, + if needed. */ + else if (TREE_CODE (t) == DECL_EXPR + && is_nrv_p (dp->nrv, DECL_EXPR_DECL (t))) + { + tree var = DECL_EXPR_DECL (t), init; + + if (DECL_INITIAL (var)) + { + init = build_binary_op (INIT_EXPR, NULL_TREE, dp->result, + DECL_INITIAL (var)); + SET_EXPR_LOCATION (init, EXPR_LOCATION (t)); + DECL_INITIAL (var) = NULL_TREE; + } + else + init = build_empty_stmt (EXPR_LOCATION (t)); + *tp = init; + + /* Identify the NRV to the RESULT_DECL for debugging purposes. */ + SET_DECL_VALUE_EXPR (var, dp->result); + DECL_HAS_VALUE_EXPR_P (var) = 1; + /* ??? Kludge to avoid an assertion failure during inlining. */ + DECL_SIZE (var) = bitsize_unit_node; + DECL_SIZE_UNIT (var) = size_one_node; + } + + /* And replace all uses of NRVs with the RESULT_DECL. */ + else if (is_nrv_p (dp->nrv, t)) + *tp = convert (TREE_TYPE (t), dp->result); + + /* Avoid walking into the same tree more than once. Unfortunately, we + can't just use walk_tree_without_duplicates because it would only + call us for the first occurrence of NRVs in the function body. */ + if (pointer_set_insert (dp->visited, *tp)) + *walk_subtrees = 0; + + return NULL_TREE; +} + +/* Likewise, but used when the function returns an unconstrained type. */ + +static tree +finalize_nrv_unc_r (tree *tp, int *walk_subtrees, void *data) +{ + struct nrv_data *dp = (struct nrv_data *)data; + tree t = *tp; + + /* No need to walk into types. */ + if (TYPE_P (t)) + *walk_subtrees = 0; + + /* We need to see the DECL_EXPR of NRVs before any other references so we + walk the body of BIND_EXPR before walking its variables. */ + else if (TREE_CODE (t) == BIND_EXPR) + walk_tree (&BIND_EXPR_BODY (t), finalize_nrv_unc_r, data, NULL); + + /* Change RETURN_EXPRs of NRVs to assign to the RESULT_DECL only the final + return value built by the allocator instead of the whole construct. */ + else if (TREE_CODE (t) == RETURN_EXPR + && TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR) + { + tree ret_val = TREE_OPERAND (TREE_OPERAND (t, 0), 1); + + /* This is the construct returned by the allocator. */ + if (TREE_CODE (ret_val) == COMPOUND_EXPR + && TREE_CODE (TREE_OPERAND (ret_val, 0)) == INIT_EXPR) + { + if (TYPE_IS_FAT_POINTER_P (TREE_TYPE (ret_val))) + ret_val + = (*CONSTRUCTOR_ELTS (TREE_OPERAND (TREE_OPERAND (ret_val, 0), + 1)))[1].value; + else + ret_val = TREE_OPERAND (TREE_OPERAND (ret_val, 0), 1); + } + + /* Strip useless conversions around the return value. */ + if (gnat_useless_type_conversion (ret_val) + || TREE_CODE (ret_val) == VIEW_CONVERT_EXPR) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Strip unpadding around the return value. */ + if (TREE_CODE (ret_val) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (ret_val, 0)))) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Assign the new return value to the RESULT_DECL. */ + if (is_nrv_p (dp->nrv, ret_val)) + TREE_OPERAND (TREE_OPERAND (t, 0), 1) + = TREE_OPERAND (DECL_INITIAL (ret_val), 0); + } + + /* Adjust the DECL_EXPR of NRVs to call the allocator and save the result + into a new variable. */ + else if (TREE_CODE (t) == DECL_EXPR + && is_nrv_p (dp->nrv, DECL_EXPR_DECL (t))) + { + tree saved_current_function_decl = current_function_decl; + tree var = DECL_EXPR_DECL (t); + tree alloc, p_array, new_var, new_ret; + vec<constructor_elt, va_gc> *v; + vec_alloc (v, 2); + + /* Create an artificial context to build the allocation. */ + current_function_decl = decl_function_context (var); + start_stmt_group (); + gnat_pushlevel (); + + /* This will return a COMPOUND_EXPR with the allocation in the first + arm and the final return value in the second arm. */ + alloc = build_allocator (TREE_TYPE (var), DECL_INITIAL (var), + TREE_TYPE (dp->result), + Procedure_To_Call (dp->gnat_ret), + Storage_Pool (dp->gnat_ret), + Empty, false); + + /* The new variable is built as a reference to the allocated space. */ + new_var + = build_decl (DECL_SOURCE_LOCATION (var), VAR_DECL, DECL_NAME (var), + build_reference_type (TREE_TYPE (var))); + DECL_BY_REFERENCE (new_var) = 1; + + if (TYPE_IS_FAT_POINTER_P (TREE_TYPE (alloc))) + { + /* The new initial value is a COMPOUND_EXPR with the allocation in + the first arm and the value of P_ARRAY in the second arm. */ + DECL_INITIAL (new_var) + = build2 (COMPOUND_EXPR, TREE_TYPE (new_var), + TREE_OPERAND (alloc, 0), + (*CONSTRUCTOR_ELTS (TREE_OPERAND (alloc, 1)))[0].value); + + /* Build a modified CONSTRUCTOR that references NEW_VAR. */ + p_array = TYPE_FIELDS (TREE_TYPE (alloc)); + CONSTRUCTOR_APPEND_ELT (v, p_array, + fold_convert (TREE_TYPE (p_array), new_var)); + CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (p_array), + (*CONSTRUCTOR_ELTS ( + TREE_OPERAND (alloc, 1)))[1].value); + new_ret = build_constructor (TREE_TYPE (alloc), v); + } + else + { + /* The new initial value is just the allocation. */ + DECL_INITIAL (new_var) = alloc; + new_ret = fold_convert (TREE_TYPE (alloc), new_var); + } + + gnat_pushdecl (new_var, Empty); + + /* Destroy the artificial context and insert the new statements. */ + gnat_zaplevel (); + *tp = end_stmt_group (); + current_function_decl = saved_current_function_decl; + + /* Chain NEW_VAR immediately after VAR and ignore the latter. */ + DECL_CHAIN (new_var) = DECL_CHAIN (var); + DECL_CHAIN (var) = new_var; + DECL_IGNORED_P (var) = 1; + + /* Save the new return value and the dereference of NEW_VAR. */ + DECL_INITIAL (var) + = build2 (COMPOUND_EXPR, TREE_TYPE (var), new_ret, + build1 (INDIRECT_REF, TREE_TYPE (var), new_var)); + /* ??? Kludge to avoid messing up during inlining. */ + DECL_CONTEXT (var) = NULL_TREE; + } + + /* And replace all uses of NRVs with the dereference of NEW_VAR. */ + else if (is_nrv_p (dp->nrv, t)) + *tp = TREE_OPERAND (DECL_INITIAL (t), 1); + + /* Avoid walking into the same tree more than once. Unfortunately, we + can't just use walk_tree_without_duplicates because it would only + call us for the first occurrence of NRVs in the function body. */ + if (pointer_set_insert (dp->visited, *tp)) + *walk_subtrees = 0; + + return NULL_TREE; +} + +/* Finalize the Named Return Value optimization for FNDECL. The NRV bitmap + contains the candidates for Named Return Value and OTHER is a list of + the other return values. GNAT_RET is a representative return node. */ + +static void +finalize_nrv (tree fndecl, bitmap nrv, vec<tree, va_gc> *other, Node_Id gnat_ret) +{ + struct cgraph_node *node; + struct nrv_data data; + walk_tree_fn func; + unsigned int i; + tree iter; + + /* We shouldn't be applying the optimization to return types that we aren't + allowed to manipulate freely. */ + gcc_assert (!TYPE_IS_BY_REFERENCE_P (TREE_TYPE (TREE_TYPE (fndecl)))); + + /* Prune the candidates that are referenced by other return values. */ + data.nrv = nrv; + data.result = NULL_TREE; + data.visited = NULL; + for (i = 0; vec_safe_iterate (other, i, &iter); i++) + walk_tree_without_duplicates (&iter, prune_nrv_r, &data); + if (bitmap_empty_p (nrv)) + return; + + /* Prune also the candidates that are referenced by nested functions. */ + node = cgraph_get_create_node (fndecl); + for (node = node->nested; node; node = node->next_nested) + walk_tree_without_duplicates (&DECL_SAVED_TREE (node->symbol.decl), prune_nrv_r, + &data); + if (bitmap_empty_p (nrv)) + return; + + /* Extract a set of NRVs with non-overlapping live ranges. */ + if (!prune_nrv_in_block (nrv, DECL_INITIAL (fndecl))) + return; + + /* Adjust the relevant RETURN_EXPRs and replace the occurrences of NRVs. */ + data.nrv = nrv; + data.result = DECL_RESULT (fndecl); + data.gnat_ret = gnat_ret; + data.visited = pointer_set_create (); + if (TYPE_RETURN_UNCONSTRAINED_P (TREE_TYPE (fndecl))) + func = finalize_nrv_unc_r; + else + func = finalize_nrv_r; + walk_tree (&DECL_SAVED_TREE (fndecl), func, &data, NULL); + pointer_set_destroy (data.visited); +} + +/* Return true if RET_VAL can be used as a Named Return Value for the + anonymous return object RET_OBJ. */ + +static bool +return_value_ok_for_nrv_p (tree ret_obj, tree ret_val) +{ + if (TREE_CODE (ret_val) != VAR_DECL) + return false; + + if (TREE_THIS_VOLATILE (ret_val)) + return false; + + if (DECL_CONTEXT (ret_val) != current_function_decl) + return false; + + if (TREE_STATIC (ret_val)) + return false; + + if (TREE_ADDRESSABLE (ret_val)) + return false; + + if (ret_obj && DECL_ALIGN (ret_val) > DECL_ALIGN (ret_obj)) + return false; + + return true; +} + +/* Build a RETURN_EXPR. If RET_VAL is non-null, build a RETURN_EXPR around + the assignment of RET_VAL to RET_OBJ. Otherwise build a bare RETURN_EXPR + around RESULT_OBJ, which may be null in this case. */ + +static tree +build_return_expr (tree ret_obj, tree ret_val) +{ + tree result_expr; + + if (ret_val) + { + /* The gimplifier explicitly enforces the following invariant: + + RETURN_EXPR + | + MODIFY_EXPR + / \ + / \ + RET_OBJ ... + + As a consequence, type consistency dictates that we use the type + of the RET_OBJ as the operation type. */ + tree operation_type = TREE_TYPE (ret_obj); + + /* Convert the right operand to the operation type. Note that it's the + same transformation as in the MODIFY_EXPR case of build_binary_op, + with the assumption that the type cannot involve a placeholder. */ + if (operation_type != TREE_TYPE (ret_val)) + ret_val = convert (operation_type, ret_val); + + result_expr = build2 (MODIFY_EXPR, void_type_node, ret_obj, ret_val); + + /* If the function returns an aggregate type, find out whether this is + a candidate for Named Return Value. If so, record it. Otherwise, + if this is an expression of some kind, record it elsewhere. */ + if (optimize + && AGGREGATE_TYPE_P (operation_type) + && !TYPE_IS_FAT_POINTER_P (operation_type) + && TYPE_MODE (operation_type) == BLKmode + && aggregate_value_p (operation_type, current_function_decl)) + { + /* Recognize the temporary created for a return value with variable + size in Call_to_gnu. We want to eliminate it if possible. */ + if (TREE_CODE (ret_val) == COMPOUND_EXPR + && TREE_CODE (TREE_OPERAND (ret_val, 0)) == INIT_EXPR + && TREE_OPERAND (TREE_OPERAND (ret_val, 0), 0) + == TREE_OPERAND (ret_val, 1)) + ret_val = TREE_OPERAND (ret_val, 1); + + /* Strip useless conversions around the return value. */ + if (gnat_useless_type_conversion (ret_val)) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Now apply the test to the return value. */ + if (return_value_ok_for_nrv_p (ret_obj, ret_val)) + { + if (!f_named_ret_val) + f_named_ret_val = BITMAP_GGC_ALLOC (); + bitmap_set_bit (f_named_ret_val, DECL_UID (ret_val)); + } + + /* Note that we need not care about CONSTRUCTORs here, as they are + totally transparent given the read-compose-write semantics of + assignments from CONSTRUCTORs. */ + else if (EXPR_P (ret_val)) + vec_safe_push (f_other_ret_val, ret_val); + } + } + else + result_expr = ret_obj; + + return build1 (RETURN_EXPR, void_type_node, result_expr); +} + +/* Build a stub for the subprogram specified by the GCC tree GNU_SUBPROG + and the GNAT node GNAT_SUBPROG. */ + +static void +build_function_stub (tree gnu_subprog, Entity_Id gnat_subprog) +{ + tree gnu_subprog_type, gnu_subprog_addr, gnu_subprog_call; + tree gnu_subprog_param, gnu_stub_param, gnu_param; + tree gnu_stub_decl = DECL_FUNCTION_STUB (gnu_subprog); + vec<tree, va_gc> *gnu_param_vec = NULL; + + gnu_subprog_type = TREE_TYPE (gnu_subprog); + + /* Initialize the information structure for the function. */ + allocate_struct_function (gnu_stub_decl, false); + set_cfun (NULL); + + begin_subprog_body (gnu_stub_decl); + + start_stmt_group (); + gnat_pushlevel (); + + /* Loop over the parameters of the stub and translate any of them + passed by descriptor into a by reference one. */ + for (gnu_stub_param = DECL_ARGUMENTS (gnu_stub_decl), + gnu_subprog_param = DECL_ARGUMENTS (gnu_subprog); + gnu_stub_param; + gnu_stub_param = DECL_CHAIN (gnu_stub_param), + gnu_subprog_param = DECL_CHAIN (gnu_subprog_param)) + { + if (DECL_BY_DESCRIPTOR_P (gnu_stub_param)) + { + gcc_assert (DECL_BY_REF_P (gnu_subprog_param)); + gnu_param + = convert_vms_descriptor (TREE_TYPE (gnu_subprog_param), + gnu_stub_param, + DECL_PARM_ALT_TYPE (gnu_stub_param), + DECL_BY_DOUBLE_REF_P (gnu_subprog_param), + gnat_subprog); + } + else + gnu_param = gnu_stub_param; + + vec_safe_push (gnu_param_vec, gnu_param); + } + + /* Invoke the internal subprogram. */ + gnu_subprog_addr = build1 (ADDR_EXPR, build_pointer_type (gnu_subprog_type), + gnu_subprog); + gnu_subprog_call = build_call_vec (TREE_TYPE (gnu_subprog_type), + gnu_subprog_addr, gnu_param_vec); + + /* Propagate the return value, if any. */ + if (VOID_TYPE_P (TREE_TYPE (gnu_subprog_type))) + add_stmt (gnu_subprog_call); + else + add_stmt (build_return_expr (DECL_RESULT (gnu_stub_decl), + gnu_subprog_call)); + + gnat_poplevel (); + end_subprog_body (end_stmt_group ()); + rest_of_subprog_body_compilation (gnu_stub_decl); +} + +/* Subroutine of gnat_to_gnu to process gnat_node, an N_Subprogram_Body. We + don't return anything. */ + +static void +Subprogram_Body_to_gnu (Node_Id gnat_node) +{ + /* Defining identifier of a parameter to the subprogram. */ + Entity_Id gnat_param; + /* The defining identifier for the subprogram body. Note that if a + specification has appeared before for this body, then the identifier + occurring in that specification will also be a defining identifier and all + the calls to this subprogram will point to that specification. */ + Entity_Id gnat_subprog_id + = (Present (Corresponding_Spec (gnat_node)) + ? Corresponding_Spec (gnat_node) : Defining_Entity (gnat_node)); + /* The FUNCTION_DECL node corresponding to the subprogram spec. */ + tree gnu_subprog_decl; + /* Its RESULT_DECL node. */ + tree gnu_result_decl; + /* Its FUNCTION_TYPE node. */ + tree gnu_subprog_type; + /* The TYPE_CI_CO_LIST of its FUNCTION_TYPE node, if any. */ + tree gnu_cico_list; + /* The entry in the CI_CO_LIST that represents a function return, if any. */ + tree gnu_return_var_elmt = NULL_TREE; + tree gnu_result; + struct language_function *gnu_subprog_language; + vec<parm_attr, va_gc> *cache; + + /* If this is a generic object or if it has been eliminated, + ignore it. */ + if (Ekind (gnat_subprog_id) == E_Generic_Procedure + || Ekind (gnat_subprog_id) == E_Generic_Function + || Is_Eliminated (gnat_subprog_id)) + return; + + /* If this subprogram acts as its own spec, define it. Otherwise, just get + the already-elaborated tree node. However, if this subprogram had its + elaboration deferred, we will already have made a tree node for it. So + treat it as not being defined in that case. Such a subprogram cannot + have an address clause or a freeze node, so this test is safe, though it + does disable some otherwise-useful error checking. */ + gnu_subprog_decl + = gnat_to_gnu_entity (gnat_subprog_id, NULL_TREE, + Acts_As_Spec (gnat_node) + && !present_gnu_tree (gnat_subprog_id)); + gnu_result_decl = DECL_RESULT (gnu_subprog_decl); + gnu_subprog_type = TREE_TYPE (gnu_subprog_decl); + gnu_cico_list = TYPE_CI_CO_LIST (gnu_subprog_type); + if (gnu_cico_list) + gnu_return_var_elmt = value_member (void_type_node, gnu_cico_list); + + /* If the function returns by invisible reference, make it explicit in the + function body. See gnat_to_gnu_entity, E_Subprogram_Type case. + Handle the explicit case here and the copy-in/copy-out case below. */ + if (TREE_ADDRESSABLE (gnu_subprog_type) && !gnu_return_var_elmt) + { + TREE_TYPE (gnu_result_decl) + = build_reference_type (TREE_TYPE (gnu_result_decl)); + relayout_decl (gnu_result_decl); + } + + /* Set the line number in the decl to correspond to that of the body so that + the line number notes are written correctly. */ + Sloc_to_locus (Sloc (gnat_node), &DECL_SOURCE_LOCATION (gnu_subprog_decl)); + + /* Initialize the information structure for the function. */ + allocate_struct_function (gnu_subprog_decl, false); + gnu_subprog_language = ggc_alloc_cleared_language_function (); + DECL_STRUCT_FUNCTION (gnu_subprog_decl)->language = gnu_subprog_language; + set_cfun (NULL); + + begin_subprog_body (gnu_subprog_decl); + + /* If there are In Out or Out parameters, we need to ensure that the return + statement properly copies them out. We do this by making a new block and + converting any return into a goto to a label at the end of the block. */ + if (gnu_cico_list) + { + tree gnu_return_var = NULL_TREE; + + vec_safe_push (gnu_return_label_stack, + create_artificial_label (input_location)); + + start_stmt_group (); + gnat_pushlevel (); + + /* If this is a function with In Out or Out parameters, we also need a + variable for the return value to be placed. */ + if (gnu_return_var_elmt) + { + tree gnu_return_type + = TREE_TYPE (TREE_PURPOSE (gnu_return_var_elmt)); + + /* If the function returns by invisible reference, make it + explicit in the function body. See gnat_to_gnu_entity, + E_Subprogram_Type case. */ + if (TREE_ADDRESSABLE (gnu_subprog_type)) + gnu_return_type = build_reference_type (gnu_return_type); + + gnu_return_var + = create_var_decl (get_identifier ("RETVAL"), NULL_TREE, + gnu_return_type, NULL_TREE, false, false, + false, false, NULL, gnat_subprog_id); + TREE_VALUE (gnu_return_var_elmt) = gnu_return_var; + } + + vec_safe_push (gnu_return_var_stack, gnu_return_var); + + /* See whether there are parameters for which we don't have a GCC tree + yet. These must be Out parameters. Make a VAR_DECL for them and + put it into TYPE_CI_CO_LIST, which must contain an empty entry too. + We can match up the entries because TYPE_CI_CO_LIST is in the order + of the parameters. */ + for (gnat_param = First_Formal_With_Extras (gnat_subprog_id); + Present (gnat_param); + gnat_param = Next_Formal_With_Extras (gnat_param)) + if (!present_gnu_tree (gnat_param)) + { + tree gnu_cico_entry = gnu_cico_list; + tree gnu_decl; + + /* Skip any entries that have been already filled in; they must + correspond to In Out parameters. */ + while (gnu_cico_entry && TREE_VALUE (gnu_cico_entry)) + gnu_cico_entry = TREE_CHAIN (gnu_cico_entry); + + /* Do any needed dereferences for by-ref objects. */ + gnu_decl = gnat_to_gnu_entity (gnat_param, NULL_TREE, 1); + gcc_assert (DECL_P (gnu_decl)); + if (DECL_BY_REF_P (gnu_decl)) + gnu_decl = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_decl); + + /* Do any needed references for padded types. */ + TREE_VALUE (gnu_cico_entry) + = convert (TREE_TYPE (TREE_PURPOSE (gnu_cico_entry)), gnu_decl); + } + } + else + vec_safe_push (gnu_return_label_stack, NULL_TREE); + + /* Get a tree corresponding to the code for the subprogram. */ + start_stmt_group (); + gnat_pushlevel (); + + /* On VMS, establish our condition handler to possibly turn a condition into + the corresponding exception if the subprogram has a foreign convention or + is exported. + + To ensure proper execution of local finalizations on condition instances, + we must turn a condition into the corresponding exception even if there + is no applicable Ada handler, and need at least one condition handler per + possible call chain involving GNAT code. OTOH, establishing the handler + has a cost so we want to minimize the number of subprograms into which + this happens. The foreign or exported condition is expected to satisfy + all the constraints. */ + if (TARGET_ABI_OPEN_VMS + && (Has_Foreign_Convention (gnat_subprog_id) + || Is_Exported (gnat_subprog_id))) + establish_gnat_vms_condition_handler (); + + process_decls (Declarations (gnat_node), Empty, Empty, true, true); + + /* Generate the code of the subprogram itself. A return statement will be + present and any Out parameters will be handled there. */ + add_stmt (gnat_to_gnu (Handled_Statement_Sequence (gnat_node))); + gnat_poplevel (); + gnu_result = end_stmt_group (); + + /* If we populated the parameter attributes cache, we need to make sure that + the cached expressions are evaluated on all the possible paths leading to + their uses. So we force their evaluation on entry of the function. */ + cache = gnu_subprog_language->parm_attr_cache; + if (cache) + { + struct parm_attr_d *pa; + int i; + + start_stmt_group (); + + FOR_EACH_VEC_ELT (*cache, i, pa) + { + if (pa->first) + add_stmt_with_node_force (pa->first, gnat_node); + if (pa->last) + add_stmt_with_node_force (pa->last, gnat_node); + if (pa->length) + add_stmt_with_node_force (pa->length, gnat_node); + } + + add_stmt (gnu_result); + gnu_result = end_stmt_group (); + + gnu_subprog_language->parm_attr_cache = NULL; + } + + /* If we are dealing with a return from an Ada procedure with parameters + passed by copy-in/copy-out, we need to return a record containing the + final values of these parameters. If the list contains only one entry, + return just that entry though. + + For a full description of the copy-in/copy-out parameter mechanism, see + the part of the gnat_to_gnu_entity routine dealing with the translation + of subprograms. + + We need to make a block that contains the definition of that label and + the copying of the return value. It first contains the function, then + the label and copy statement. */ + if (gnu_cico_list) + { + tree gnu_retval; + + add_stmt (gnu_result); + add_stmt (build1 (LABEL_EXPR, void_type_node, + gnu_return_label_stack->last ())); + + if (list_length (gnu_cico_list) == 1) + gnu_retval = TREE_VALUE (gnu_cico_list); + else + gnu_retval = build_constructor_from_list (TREE_TYPE (gnu_subprog_type), + gnu_cico_list); + + add_stmt_with_node (build_return_expr (gnu_result_decl, gnu_retval), + End_Label (Handled_Statement_Sequence (gnat_node))); + gnat_poplevel (); + gnu_result = end_stmt_group (); + } + + gnu_return_label_stack->pop (); + + /* Attempt setting the end_locus of our GCC body tree, typically a + BIND_EXPR or STATEMENT_LIST, then the end_locus of our GCC subprogram + declaration tree. */ + set_end_locus_from_node (gnu_result, gnat_node); + set_end_locus_from_node (gnu_subprog_decl, gnat_node); + + /* On SEH targets, install an exception handler around the main entry + point to catch unhandled exceptions. */ + if (DECL_NAME (gnu_subprog_decl) == main_identifier_node + && targetm_common.except_unwind_info (&global_options) == UI_SEH) + { + tree t; + tree etype; + + t = build_call_expr (builtin_decl_explicit (BUILT_IN_EH_POINTER), + 1, integer_zero_node); + t = build_call_n_expr (unhandled_except_decl, 1, t); + + etype = build_unary_op (ADDR_EXPR, NULL_TREE, unhandled_others_decl); + etype = tree_cons (NULL_TREE, etype, NULL_TREE); + + t = build2 (CATCH_EXPR, void_type_node, etype, t); + gnu_result = build2 (TRY_CATCH_EXPR, TREE_TYPE (gnu_result), + gnu_result, t); + } + + end_subprog_body (gnu_result); + + /* Finally annotate the parameters and disconnect the trees for parameters + that we have turned into variables since they are now unusable. */ + for (gnat_param = First_Formal_With_Extras (gnat_subprog_id); + Present (gnat_param); + gnat_param = Next_Formal_With_Extras (gnat_param)) + { + tree gnu_param = get_gnu_tree (gnat_param); + bool is_var_decl = (TREE_CODE (gnu_param) == VAR_DECL); + + annotate_object (gnat_param, TREE_TYPE (gnu_param), NULL_TREE, + DECL_BY_REF_P (gnu_param), + !is_var_decl && DECL_BY_DOUBLE_REF_P (gnu_param)); + + if (is_var_decl) + save_gnu_tree (gnat_param, NULL_TREE, false); + } + + /* Disconnect the variable created for the return value. */ + if (gnu_return_var_elmt) + TREE_VALUE (gnu_return_var_elmt) = void_type_node; + + /* If the function returns an aggregate type and we have candidates for + a Named Return Value, finalize the optimization. */ + if (optimize && gnu_subprog_language->named_ret_val) + { + finalize_nrv (gnu_subprog_decl, + gnu_subprog_language->named_ret_val, + gnu_subprog_language->other_ret_val, + gnu_subprog_language->gnat_ret); + gnu_subprog_language->named_ret_val = NULL; + gnu_subprog_language->other_ret_val = NULL; + } + + rest_of_subprog_body_compilation (gnu_subprog_decl); + + /* If there is a stub associated with the function, build it now. */ + if (DECL_FUNCTION_STUB (gnu_subprog_decl)) + build_function_stub (gnu_subprog_decl, gnat_subprog_id); +} + +/* Return true if GNAT_NODE requires atomic synchronization. */ + +static bool +atomic_sync_required_p (Node_Id gnat_node) +{ + const Node_Id gnat_parent = Parent (gnat_node); + Node_Kind kind; + unsigned char attr_id; + + /* First, scan the node to find the Atomic_Sync_Required flag. */ + kind = Nkind (gnat_node); + if (kind == N_Type_Conversion || kind == N_Unchecked_Type_Conversion) + { + gnat_node = Expression (gnat_node); + kind = Nkind (gnat_node); + } + + switch (kind) + { + case N_Expanded_Name: + case N_Explicit_Dereference: + case N_Identifier: + case N_Indexed_Component: + case N_Selected_Component: + if (!Atomic_Sync_Required (gnat_node)) + return false; + break; + + default: + return false; + } + + /* Then, scan the parent to find out cases where the flag is irrelevant. */ + kind = Nkind (gnat_parent); + switch (kind) + { + case N_Attribute_Reference: + attr_id = Get_Attribute_Id (Attribute_Name (gnat_parent)); + /* Do not mess up machine code insertions. */ + if (attr_id == Attr_Asm_Input || attr_id == Attr_Asm_Output) + return false; + break; + + case N_Object_Renaming_Declaration: + /* Do not generate a function call as a renamed object. */ + return false; + + default: + break; + } + + return true; +} + +/* Create a temporary variable with PREFIX and TYPE, and return it. */ + +static tree +create_temporary (const char *prefix, tree type) +{ + tree gnu_temp = create_var_decl (create_tmp_var_name (prefix), NULL_TREE, + type, NULL_TREE, false, false, false, false, + NULL, Empty); + DECL_ARTIFICIAL (gnu_temp) = 1; + DECL_IGNORED_P (gnu_temp) = 1; + + return gnu_temp; +} + +/* Create a temporary variable with PREFIX and initialize it with GNU_INIT. + Put the initialization statement into GNU_INIT_STMT and annotate it with + the SLOC of GNAT_NODE. Return the temporary variable. */ + +static tree +create_init_temporary (const char *prefix, tree gnu_init, tree *gnu_init_stmt, + Node_Id gnat_node) +{ + tree gnu_temp = create_temporary (prefix, TREE_TYPE (gnu_init)); + + *gnu_init_stmt = build_binary_op (INIT_EXPR, NULL_TREE, gnu_temp, gnu_init); + set_expr_location_from_node (*gnu_init_stmt, gnat_node); + + return gnu_temp; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, either an N_Function_Call + or an N_Procedure_Call_Statement, to a GCC tree, which is returned. + GNU_RESULT_TYPE_P is a pointer to where we should place the result type. + If GNU_TARGET is non-null, this must be a function call on the RHS of a + N_Assignment_Statement and the result is to be placed into that object. + If, in addition, ATOMIC_SYNC is true, then the assignment to GNU_TARGET + requires atomic synchronization. */ + +static tree +Call_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, tree gnu_target, + bool atomic_sync) +{ + const bool function_call = (Nkind (gnat_node) == N_Function_Call); + const bool returning_value = (function_call && !gnu_target); + /* The GCC node corresponding to the GNAT subprogram name. This can either + be a FUNCTION_DECL node if we are dealing with a standard subprogram call, + or an indirect reference expression (an INDIRECT_REF node) pointing to a + subprogram. */ + tree gnu_subprog = gnat_to_gnu (Name (gnat_node)); + /* The FUNCTION_TYPE node giving the GCC type of the subprogram. */ + tree gnu_subprog_type = TREE_TYPE (gnu_subprog); + /* The return type of the FUNCTION_TYPE. */ + tree gnu_result_type = TREE_TYPE (gnu_subprog_type); + tree gnu_subprog_addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_subprog); + vec<tree, va_gc> *gnu_actual_vec = NULL; + tree gnu_name_list = NULL_TREE; + tree gnu_stmt_list = NULL_TREE; + tree gnu_after_list = NULL_TREE; + tree gnu_retval = NULL_TREE; + tree gnu_call, gnu_result; + bool went_into_elab_proc = false; + bool pushed_binding_level = false; + Entity_Id gnat_formal; + Node_Id gnat_actual; + + gcc_assert (TREE_CODE (gnu_subprog_type) == FUNCTION_TYPE); + + /* If we are calling a stubbed function, raise Program_Error, but Elaborate + all our args first. */ + if (TREE_CODE (gnu_subprog) == FUNCTION_DECL && DECL_STUBBED_P (gnu_subprog)) + { + tree call_expr = build_call_raise (PE_Stubbed_Subprogram_Called, + gnat_node, N_Raise_Program_Error); + + for (gnat_actual = First_Actual (gnat_node); + Present (gnat_actual); + gnat_actual = Next_Actual (gnat_actual)) + add_stmt (gnat_to_gnu (gnat_actual)); + + if (returning_value) + { + *gnu_result_type_p = gnu_result_type; + return build1 (NULL_EXPR, gnu_result_type, call_expr); + } + + return call_expr; + } + + /* The only way we can be making a call via an access type is if Name is an + explicit dereference. In that case, get the list of formal args from the + type the access type is pointing to. Otherwise, get the formals from the + entity being called. */ + if (Nkind (Name (gnat_node)) == N_Explicit_Dereference) + gnat_formal = First_Formal_With_Extras (Etype (Name (gnat_node))); + else if (Nkind (Name (gnat_node)) == N_Attribute_Reference) + /* Assume here that this must be 'Elab_Body or 'Elab_Spec. */ + gnat_formal = Empty; + else + gnat_formal = First_Formal_With_Extras (Entity (Name (gnat_node))); + + /* The lifetime of the temporaries created for the call ends right after the + return value is copied, so we can give them the scope of the elaboration + routine at top level. */ + if (!current_function_decl) + { + current_function_decl = get_elaboration_procedure (); + went_into_elab_proc = true; + } + + /* First, create the temporary for the return value when: + + 1. There is no target and the function has copy-in/copy-out parameters, + because we need to preserve the return value before copying back the + parameters. + + 2. There is no target and this is not an object declaration, and the + return type has variable size, because in these cases the gimplifier + cannot create the temporary. + + 3. There is a target and it is a slice or an array with fixed size, + and the return type has variable size, because the gimplifier + doesn't handle these cases. + + This must be done before we push a binding level around the call, since + we will pop it before copying the return value. */ + if (function_call + && ((!gnu_target && TYPE_CI_CO_LIST (gnu_subprog_type)) + || (!gnu_target + && Nkind (Parent (gnat_node)) != N_Object_Declaration + && TREE_CODE (TYPE_SIZE (gnu_result_type)) != INTEGER_CST) + || (gnu_target + && (TREE_CODE (gnu_target) == ARRAY_RANGE_REF + || (TREE_CODE (TREE_TYPE (gnu_target)) == ARRAY_TYPE + && TREE_CODE (TYPE_SIZE (TREE_TYPE (gnu_target))) + == INTEGER_CST)) + && TREE_CODE (TYPE_SIZE (gnu_result_type)) != INTEGER_CST))) + gnu_retval = create_temporary ("R", gnu_result_type); + + /* Create the list of the actual parameters as GCC expects it, namely a + chain of TREE_LIST nodes in which the TREE_VALUE field of each node + is an expression and the TREE_PURPOSE field is null. But skip Out + parameters not passed by reference and that need not be copied in. */ + for (gnat_actual = First_Actual (gnat_node); + Present (gnat_actual); + gnat_formal = Next_Formal_With_Extras (gnat_formal), + gnat_actual = Next_Actual (gnat_actual)) + { + tree gnu_formal = present_gnu_tree (gnat_formal) + ? get_gnu_tree (gnat_formal) : NULL_TREE; + tree gnu_formal_type = gnat_to_gnu_type (Etype (gnat_formal)); + const bool is_true_formal_parm + = gnu_formal && TREE_CODE (gnu_formal) == PARM_DECL; + const bool is_by_ref_formal_parm + = is_true_formal_parm + && (DECL_BY_REF_P (gnu_formal) + || DECL_BY_COMPONENT_PTR_P (gnu_formal) + || DECL_BY_DESCRIPTOR_P (gnu_formal)); + /* In the Out or In Out case, we must suppress conversions that yield + an lvalue but can nevertheless cause the creation of a temporary, + because we need the real object in this case, either to pass its + address if it's passed by reference or as target of the back copy + done after the call if it uses the copy-in/copy-out mechanism. + We do it in the In case too, except for an unchecked conversion + because it alone can cause the actual to be misaligned and the + addressability test is applied to the real object. */ + const bool suppress_type_conversion + = ((Nkind (gnat_actual) == N_Unchecked_Type_Conversion + && Ekind (gnat_formal) != E_In_Parameter) + || (Nkind (gnat_actual) == N_Type_Conversion + && Is_Composite_Type (Underlying_Type (Etype (gnat_formal))))); + Node_Id gnat_name = suppress_type_conversion + ? Expression (gnat_actual) : gnat_actual; + tree gnu_name = gnat_to_gnu (gnat_name), gnu_name_type; + tree gnu_actual; + + /* If it's possible we may need to use this expression twice, make sure + that any side-effects are handled via SAVE_EXPRs; likewise if we need + to force side-effects before the call. + ??? This is more conservative than we need since we don't need to do + this for pass-by-ref with no conversion. */ + if (Ekind (gnat_formal) != E_In_Parameter) + gnu_name = gnat_stabilize_reference (gnu_name, true, NULL); + + /* If we are passing a non-addressable parameter by reference, pass the + address of a copy. In the Out or In Out case, set up to copy back + out after the call. */ + if (is_by_ref_formal_parm + && (gnu_name_type = gnat_to_gnu_type (Etype (gnat_name))) + && !addressable_p (gnu_name, gnu_name_type)) + { + bool in_param = (Ekind (gnat_formal) == E_In_Parameter); + tree gnu_orig = gnu_name, gnu_temp, gnu_stmt; + + /* Do not issue warnings for CONSTRUCTORs since this is not a copy + but sort of an instantiation for them. */ + if (TREE_CODE (gnu_name) == CONSTRUCTOR) + ; + + /* If the type is passed by reference, a copy is not allowed. */ + else if (TYPE_IS_BY_REFERENCE_P (gnu_formal_type)) + post_error ("misaligned actual cannot be passed by reference", + gnat_actual); + + /* For users of Starlet we issue a warning because the interface + apparently assumes that by-ref parameters outlive the procedure + invocation. The code still will not work as intended, but we + cannot do much better since low-level parts of the back-end + would allocate temporaries at will because of the misalignment + if we did not do so here. */ + else if (Is_Valued_Procedure (Entity (Name (gnat_node)))) + { + post_error + ("?possible violation of implicit assumption", gnat_actual); + post_error_ne + ("?made by pragma Import_Valued_Procedure on &", gnat_actual, + Entity (Name (gnat_node))); + post_error_ne ("?because of misalignment of &", gnat_actual, + gnat_formal); + } + + /* If the actual type of the object is already the nominal type, + we have nothing to do, except if the size is self-referential + in which case we'll remove the unpadding below. */ + if (TREE_TYPE (gnu_name) == gnu_name_type + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_name_type))) + ; + + /* Otherwise remove the unpadding from all the objects. */ + else if (TREE_CODE (gnu_name) == COMPONENT_REF + && TYPE_IS_PADDING_P + (TREE_TYPE (TREE_OPERAND (gnu_name, 0)))) + gnu_orig = gnu_name = TREE_OPERAND (gnu_name, 0); + + /* Otherwise convert to the nominal type of the object if needed. + There are several cases in which we need to make the temporary + using this type instead of the actual type of the object when + they are distinct, because the expectations of the callee would + otherwise not be met: + - if it's a justified modular type, + - if the actual type is a smaller form of it, + - if it's a smaller form of the actual type. */ + else if ((TREE_CODE (gnu_name_type) == RECORD_TYPE + && (TYPE_JUSTIFIED_MODULAR_P (gnu_name_type) + || smaller_form_type_p (TREE_TYPE (gnu_name), + gnu_name_type))) + || (INTEGRAL_TYPE_P (gnu_name_type) + && smaller_form_type_p (gnu_name_type, + TREE_TYPE (gnu_name)))) + gnu_name = convert (gnu_name_type, gnu_name); + + /* If this is an In Out or Out parameter and we're returning a value, + we need to create a temporary for the return value because we must + preserve it before copying back at the very end. */ + if (!in_param && returning_value && !gnu_retval) + gnu_retval = create_temporary ("R", gnu_result_type); + + /* If we haven't pushed a binding level, push a new one. This will + narrow the lifetime of the temporary we are about to make as much + as possible. The drawback is that we'd need to create a temporary + for the return value, if any (see comment before the loop). So do + it only when this temporary was already created just above. */ + if (!pushed_binding_level && !(in_param && returning_value)) + { + start_stmt_group (); + gnat_pushlevel (); + pushed_binding_level = true; + } + + /* Create an explicit temporary holding the copy. */ + gnu_temp + = create_init_temporary ("A", gnu_name, &gnu_stmt, gnat_actual); + + /* But initialize it on the fly like for an implicit temporary as + we aren't necessarily having a statement list. */ + gnu_name = build_compound_expr (TREE_TYPE (gnu_name), gnu_stmt, + gnu_temp); + + /* Set up to move the copy back to the original if needed. */ + if (!in_param) + { + gnu_stmt = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_orig, + gnu_temp); + set_expr_location_from_node (gnu_stmt, gnat_node); + append_to_statement_list (gnu_stmt, &gnu_after_list); + } + } + + /* Start from the real object and build the actual. */ + gnu_actual = gnu_name; + + /* If this is an atomic access of an In or In Out parameter for which + synchronization is required, build the atomic load. */ + if (is_true_formal_parm + && !is_by_ref_formal_parm + && Ekind (gnat_formal) != E_Out_Parameter + && atomic_sync_required_p (gnat_actual)) + gnu_actual = build_atomic_load (gnu_actual); + + /* If this was a procedure call, we may not have removed any padding. + So do it here for the part we will use as an input, if any. */ + if (Ekind (gnat_formal) != E_Out_Parameter + && TYPE_IS_PADDING_P (TREE_TYPE (gnu_actual))) + gnu_actual + = convert (get_unpadded_type (Etype (gnat_actual)), gnu_actual); + + /* Put back the conversion we suppressed above in the computation of the + real object. And even if we didn't suppress any conversion there, we + may have suppressed a conversion to the Etype of the actual earlier, + since the parent is a procedure call, so put it back here. */ + if (suppress_type_conversion + && Nkind (gnat_actual) == N_Unchecked_Type_Conversion) + gnu_actual + = unchecked_convert (gnat_to_gnu_type (Etype (gnat_actual)), + gnu_actual, No_Truncation (gnat_actual)); + else + gnu_actual + = convert (gnat_to_gnu_type (Etype (gnat_actual)), gnu_actual); + + /* Make sure that the actual is in range of the formal's type. */ + if (Ekind (gnat_formal) != E_Out_Parameter + && Do_Range_Check (gnat_actual)) + gnu_actual + = emit_range_check (gnu_actual, Etype (gnat_formal), gnat_actual); + + /* Unless this is an In parameter, we must remove any justified modular + building from GNU_NAME to get an lvalue. */ + if (Ekind (gnat_formal) != E_In_Parameter + && TREE_CODE (gnu_name) == CONSTRUCTOR + && TREE_CODE (TREE_TYPE (gnu_name)) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (TREE_TYPE (gnu_name))) + gnu_name + = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_name))), gnu_name); + + /* If we have not saved a GCC object for the formal, it means it is an + Out parameter not passed by reference and that need not be copied in. + Otherwise, first see if the parameter is passed by reference. */ + if (is_true_formal_parm && DECL_BY_REF_P (gnu_formal)) + { + if (Ekind (gnat_formal) != E_In_Parameter) + { + /* In Out or Out parameters passed by reference don't use the + copy-in/copy-out mechanism so the address of the real object + must be passed to the function. */ + gnu_actual = gnu_name; + + /* If we have a padded type, be sure we've removed padding. */ + if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_actual))) + gnu_actual = convert (get_unpadded_type (Etype (gnat_actual)), + gnu_actual); + + /* If we have the constructed subtype of an aliased object + with an unconstrained nominal subtype, the type of the + actual includes the template, although it is formally + constrained. So we need to convert it back to the real + constructed subtype to retrieve the constrained part + and takes its address. */ + if (TREE_CODE (TREE_TYPE (gnu_actual)) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (gnu_actual)) + && Is_Constr_Subt_For_UN_Aliased (Etype (gnat_actual)) + && Is_Array_Type (Etype (gnat_actual))) + gnu_actual = convert (gnat_to_gnu_type (Etype (gnat_actual)), + gnu_actual); + } + + /* There is no need to convert the actual to the formal's type before + taking its address. The only exception is for unconstrained array + types because of the way we build fat pointers. */ + if (TREE_CODE (gnu_formal_type) == UNCONSTRAINED_ARRAY_TYPE) + { + /* Put back a view conversion for In Out or Out parameters. */ + if (Ekind (gnat_formal) != E_In_Parameter) + gnu_actual = convert (gnat_to_gnu_type (Etype (gnat_actual)), + gnu_actual); + gnu_actual = convert (gnu_formal_type, gnu_actual); + } + + /* The symmetry of the paths to the type of an entity is broken here + since arguments don't know that they will be passed by ref. */ + gnu_formal_type = TREE_TYPE (gnu_formal); + + if (DECL_BY_DOUBLE_REF_P (gnu_formal)) + gnu_actual + = build_unary_op (ADDR_EXPR, TREE_TYPE (gnu_formal_type), + gnu_actual); + + gnu_actual = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual); + } + else if (is_true_formal_parm && DECL_BY_COMPONENT_PTR_P (gnu_formal)) + { + gnu_formal_type = TREE_TYPE (gnu_formal); + gnu_actual = maybe_implicit_deref (gnu_actual); + gnu_actual = maybe_unconstrained_array (gnu_actual); + + if (TYPE_IS_PADDING_P (gnu_formal_type)) + { + gnu_formal_type = TREE_TYPE (TYPE_FIELDS (gnu_formal_type)); + gnu_actual = convert (gnu_formal_type, gnu_actual); + } + + /* Take the address of the object and convert to the proper pointer + type. We'd like to actually compute the address of the beginning + of the array using an ADDR_EXPR of an ARRAY_REF, but there's a + possibility that the ARRAY_REF might return a constant and we'd be + getting the wrong address. Neither approach is exactly correct, + but this is the most likely to work in all cases. */ + gnu_actual = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual); + } + else if (is_true_formal_parm && DECL_BY_DESCRIPTOR_P (gnu_formal)) + { + gnu_actual = convert (gnu_formal_type, gnu_actual); + + /* If this is 'Null_Parameter, pass a zero descriptor. */ + if ((TREE_CODE (gnu_actual) == INDIRECT_REF + || TREE_CODE (gnu_actual) == UNCONSTRAINED_ARRAY_REF) + && TREE_PRIVATE (gnu_actual)) + gnu_actual + = convert (DECL_ARG_TYPE (gnu_formal), integer_zero_node); + else + gnu_actual = build_unary_op (ADDR_EXPR, NULL_TREE, + fill_vms_descriptor + (TREE_TYPE (TREE_TYPE (gnu_formal)), + gnu_actual, gnat_actual)); + } + else + { + tree gnu_size; + + if (Ekind (gnat_formal) != E_In_Parameter) + gnu_name_list = tree_cons (NULL_TREE, gnu_name, gnu_name_list); + + if (!is_true_formal_parm) + { + /* Make sure side-effects are evaluated before the call. */ + if (TREE_SIDE_EFFECTS (gnu_name)) + append_to_statement_list (gnu_name, &gnu_stmt_list); + continue; + } + + gnu_actual = convert (gnu_formal_type, gnu_actual); + + /* If this is 'Null_Parameter, pass a zero even though we are + dereferencing it. */ + if (TREE_CODE (gnu_actual) == INDIRECT_REF + && TREE_PRIVATE (gnu_actual) + && (gnu_size = TYPE_SIZE (TREE_TYPE (gnu_actual))) + && TREE_CODE (gnu_size) == INTEGER_CST + && compare_tree_int (gnu_size, BITS_PER_WORD) <= 0) + gnu_actual + = unchecked_convert (DECL_ARG_TYPE (gnu_formal), + convert (gnat_type_for_size + (TREE_INT_CST_LOW (gnu_size), 1), + integer_zero_node), + false); + else + gnu_actual = convert (DECL_ARG_TYPE (gnu_formal), gnu_actual); + } + + vec_safe_push (gnu_actual_vec, gnu_actual); + } + + gnu_call + = build_call_vec (gnu_result_type, gnu_subprog_addr, gnu_actual_vec); + set_expr_location_from_node (gnu_call, gnat_node); + + /* If we have created a temporary for the return value, initialize it. */ + if (gnu_retval) + { + tree gnu_stmt + = build_binary_op (INIT_EXPR, NULL_TREE, gnu_retval, gnu_call); + set_expr_location_from_node (gnu_stmt, gnat_node); + append_to_statement_list (gnu_stmt, &gnu_stmt_list); + gnu_call = gnu_retval; + } + + /* If this is a subprogram with copy-in/copy-out parameters, we need to + unpack the valued returned from the function into the In Out or Out + parameters. We deal with the function return (if this is an Ada + function) below. */ + if (TYPE_CI_CO_LIST (gnu_subprog_type)) + { + /* List of FIELD_DECLs associated with the PARM_DECLs of the copy-in/ + copy-out parameters. */ + tree gnu_cico_list = TYPE_CI_CO_LIST (gnu_subprog_type); + const int length = list_length (gnu_cico_list); + + /* The call sequence must contain one and only one call, even though the + function is pure. Save the result into a temporary if needed. */ + if (length > 1) + { + if (!gnu_retval) + { + tree gnu_stmt; + /* If we haven't pushed a binding level, push a new one. This + will narrow the lifetime of the temporary we are about to + make as much as possible. */ + if (!pushed_binding_level) + { + start_stmt_group (); + gnat_pushlevel (); + pushed_binding_level = true; + } + gnu_call + = create_init_temporary ("P", gnu_call, &gnu_stmt, gnat_node); + append_to_statement_list (gnu_stmt, &gnu_stmt_list); + } + + gnu_name_list = nreverse (gnu_name_list); + } + + /* The first entry is for the actual return value if this is a + function, so skip it. */ + if (function_call) + gnu_cico_list = TREE_CHAIN (gnu_cico_list); + + if (Nkind (Name (gnat_node)) == N_Explicit_Dereference) + gnat_formal = First_Formal_With_Extras (Etype (Name (gnat_node))); + else + gnat_formal = First_Formal_With_Extras (Entity (Name (gnat_node))); + + for (gnat_actual = First_Actual (gnat_node); + Present (gnat_actual); + gnat_formal = Next_Formal_With_Extras (gnat_formal), + gnat_actual = Next_Actual (gnat_actual)) + /* If we are dealing with a copy-in/copy-out parameter, we must + retrieve its value from the record returned in the call. */ + if (!(present_gnu_tree (gnat_formal) + && TREE_CODE (get_gnu_tree (gnat_formal)) == PARM_DECL + && (DECL_BY_REF_P (get_gnu_tree (gnat_formal)) + || (TREE_CODE (get_gnu_tree (gnat_formal)) == PARM_DECL + && ((DECL_BY_COMPONENT_PTR_P (get_gnu_tree (gnat_formal)) + || (DECL_BY_DESCRIPTOR_P + (get_gnu_tree (gnat_formal)))))))) + && Ekind (gnat_formal) != E_In_Parameter) + { + /* Get the value to assign to this Out or In Out parameter. It is + either the result of the function if there is only a single such + parameter or the appropriate field from the record returned. */ + tree gnu_result + = length == 1 + ? gnu_call + : build_component_ref (gnu_call, NULL_TREE, + TREE_PURPOSE (gnu_cico_list), false); + + /* If the actual is a conversion, get the inner expression, which + will be the real destination, and convert the result to the + type of the actual parameter. */ + tree gnu_actual + = maybe_unconstrained_array (TREE_VALUE (gnu_name_list)); + + /* If the result is a padded type, remove the padding. */ + if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_result))) + gnu_result + = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_result))), + gnu_result); + + /* If the actual is a type conversion, the real target object is + denoted by the inner Expression and we need to convert the + result to the associated type. + We also need to convert our gnu assignment target to this type + if the corresponding GNU_NAME was constructed from the GNAT + conversion node and not from the inner Expression. */ + if (Nkind (gnat_actual) == N_Type_Conversion) + { + gnu_result + = convert_with_check + (Etype (Expression (gnat_actual)), gnu_result, + Do_Overflow_Check (gnat_actual), + Do_Range_Check (Expression (gnat_actual)), + Float_Truncate (gnat_actual), gnat_actual); + + if (!Is_Composite_Type (Underlying_Type (Etype (gnat_formal)))) + gnu_actual = convert (TREE_TYPE (gnu_result), gnu_actual); + } + + /* Unchecked conversions as actuals for Out parameters are not + allowed in user code because they are not variables, but do + occur in front-end expansions. The associated GNU_NAME is + always obtained from the inner expression in such cases. */ + else if (Nkind (gnat_actual) == N_Unchecked_Type_Conversion) + gnu_result = unchecked_convert (TREE_TYPE (gnu_actual), + gnu_result, + No_Truncation (gnat_actual)); + else + { + if (Do_Range_Check (gnat_actual)) + gnu_result + = emit_range_check (gnu_result, Etype (gnat_actual), + gnat_actual); + + if (!(!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (gnu_actual))) + && TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (gnu_result))))) + gnu_result = convert (TREE_TYPE (gnu_actual), gnu_result); + } + + if (atomic_sync_required_p (gnat_actual)) + gnu_result = build_atomic_store (gnu_actual, gnu_result); + else + gnu_result = build_binary_op (MODIFY_EXPR, NULL_TREE, + gnu_actual, gnu_result); + set_expr_location_from_node (gnu_result, gnat_node); + append_to_statement_list (gnu_result, &gnu_stmt_list); + gnu_cico_list = TREE_CHAIN (gnu_cico_list); + gnu_name_list = TREE_CHAIN (gnu_name_list); + } + } + + /* If this is a function call, the result is the call expression unless a + target is specified, in which case we copy the result into the target + and return the assignment statement. */ + if (function_call) + { + /* If this is a function with copy-in/copy-out parameters, extract the + return value from it and update the return type. */ + if (TYPE_CI_CO_LIST (gnu_subprog_type)) + { + tree gnu_elmt = TYPE_CI_CO_LIST (gnu_subprog_type); + gnu_call = build_component_ref (gnu_call, NULL_TREE, + TREE_PURPOSE (gnu_elmt), false); + gnu_result_type = TREE_TYPE (gnu_call); + } + + /* If the function returns an unconstrained array or by direct reference, + we have to dereference the pointer. */ + if (TYPE_RETURN_UNCONSTRAINED_P (gnu_subprog_type) + || TYPE_RETURN_BY_DIRECT_REF_P (gnu_subprog_type)) + gnu_call = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_call); + + if (gnu_target) + { + Node_Id gnat_parent = Parent (gnat_node); + enum tree_code op_code; + + /* If range check is needed, emit code to generate it. */ + if (Do_Range_Check (gnat_node)) + gnu_call + = emit_range_check (gnu_call, Etype (Name (gnat_parent)), + gnat_parent); + + /* ??? If the return type has variable size, then force the return + slot optimization as we would not be able to create a temporary. + Likewise if it was unconstrained as we would copy too much data. + That's what has been done historically. */ + if (TREE_CODE (TYPE_SIZE (gnu_result_type)) != INTEGER_CST + || (TYPE_IS_PADDING_P (gnu_result_type) + && CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS (gnu_result_type)))))) + op_code = INIT_EXPR; + else + op_code = MODIFY_EXPR; + + if (atomic_sync) + gnu_call = build_atomic_store (gnu_target, gnu_call); + else + gnu_call + = build_binary_op (op_code, NULL_TREE, gnu_target, gnu_call); + set_expr_location_from_node (gnu_call, gnat_parent); + append_to_statement_list (gnu_call, &gnu_stmt_list); + } + else + *gnu_result_type_p = get_unpadded_type (Etype (gnat_node)); + } + + /* Otherwise, if this is a procedure call statement without copy-in/copy-out + parameters, the result is just the call statement. */ + else if (!TYPE_CI_CO_LIST (gnu_subprog_type)) + append_to_statement_list (gnu_call, &gnu_stmt_list); + + /* Finally, add the copy back statements, if any. */ + append_to_statement_list (gnu_after_list, &gnu_stmt_list); + + if (went_into_elab_proc) + current_function_decl = NULL_TREE; + + /* If we have pushed a binding level, pop it and finish up the enclosing + statement group. */ + if (pushed_binding_level) + { + add_stmt (gnu_stmt_list); + gnat_poplevel (); + gnu_result = end_stmt_group (); + } + + /* Otherwise, retrieve the statement list, if any. */ + else if (gnu_stmt_list) + gnu_result = gnu_stmt_list; + + /* Otherwise, just return the call expression. */ + else + return gnu_call; + + /* If we nevertheless need a value, make a COMPOUND_EXPR to return it. + But first simplify if we have only one statement in the list. */ + if (returning_value) + { + tree first = expr_first (gnu_result), last = expr_last (gnu_result); + if (first == last) + gnu_result = first; + gnu_result + = build_compound_expr (TREE_TYPE (gnu_call), gnu_result, gnu_call); + } + + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an + N_Handled_Sequence_Of_Statements, to a GCC tree, which is returned. */ + +static tree +Handled_Sequence_Of_Statements_to_gnu (Node_Id gnat_node) +{ + tree gnu_jmpsave_decl = NULL_TREE; + tree gnu_jmpbuf_decl = NULL_TREE; + /* If just annotating, ignore all EH and cleanups. */ + bool gcc_zcx = (!type_annotate_only + && Present (Exception_Handlers (gnat_node)) + && Exception_Mechanism == Back_End_Exceptions); + bool setjmp_longjmp + = (!type_annotate_only && Present (Exception_Handlers (gnat_node)) + && Exception_Mechanism == Setjmp_Longjmp); + bool at_end = !type_annotate_only && Present (At_End_Proc (gnat_node)); + bool binding_for_block = (at_end || gcc_zcx || setjmp_longjmp); + tree gnu_inner_block; /* The statement(s) for the block itself. */ + tree gnu_result; + tree gnu_expr; + Node_Id gnat_temp; + + /* The GCC exception handling mechanism can handle both ZCX and SJLJ schemes + and we have our own SJLJ mechanism. To call the GCC mechanism, we call + add_cleanup, and when we leave the binding, end_stmt_group will create + the TRY_FINALLY_EXPR. + + ??? The region level calls down there have been specifically put in place + for a ZCX context and currently the order in which things are emitted + (region/handlers) is different from the SJLJ case. Instead of putting + other calls with different conditions at other places for the SJLJ case, + it seems cleaner to reorder things for the SJLJ case and generalize the + condition to make it not ZCX specific. + + If there are any exceptions or cleanup processing involved, we need an + outer statement group (for Setjmp_Longjmp) and binding level. */ + if (binding_for_block) + { + start_stmt_group (); + gnat_pushlevel (); + } + + /* If using setjmp_longjmp, make the variables for the setjmp buffer and save + area for address of previous buffer. Do this first since we need to have + the setjmp buf known for any decls in this block. */ + if (setjmp_longjmp) + { + gnu_jmpsave_decl + = create_var_decl (get_identifier ("JMPBUF_SAVE"), NULL_TREE, + jmpbuf_ptr_type, + build_call_n_expr (get_jmpbuf_decl, 0), + false, false, false, false, NULL, gnat_node); + DECL_ARTIFICIAL (gnu_jmpsave_decl) = 1; + + /* The __builtin_setjmp receivers will immediately reinstall it. Now + because of the unstructured form of EH used by setjmp_longjmp, there + might be forward edges going to __builtin_setjmp receivers on which + it is uninitialized, although they will never be actually taken. */ + TREE_NO_WARNING (gnu_jmpsave_decl) = 1; + gnu_jmpbuf_decl + = create_var_decl (get_identifier ("JMP_BUF"), NULL_TREE, + jmpbuf_type, + NULL_TREE, + false, false, false, false, NULL, gnat_node); + DECL_ARTIFICIAL (gnu_jmpbuf_decl) = 1; + + set_block_jmpbuf_decl (gnu_jmpbuf_decl); + + /* When we exit this block, restore the saved value. */ + add_cleanup (build_call_n_expr (set_jmpbuf_decl, 1, gnu_jmpsave_decl), + End_Label (gnat_node)); + } + + /* If we are to call a function when exiting this block, add a cleanup + to the binding level we made above. Note that add_cleanup is FIFO + so we must register this cleanup after the EH cleanup just above. */ + if (at_end) + add_cleanup (build_call_n_expr (gnat_to_gnu (At_End_Proc (gnat_node)), 0), + End_Label (gnat_node)); + + /* Now build the tree for the declarations and statements inside this block. + If this is SJLJ, set our jmp_buf as the current buffer. */ + start_stmt_group (); + + if (setjmp_longjmp) + add_stmt (build_call_n_expr (set_jmpbuf_decl, 1, + build_unary_op (ADDR_EXPR, NULL_TREE, + gnu_jmpbuf_decl))); + + if (Present (First_Real_Statement (gnat_node))) + process_decls (Statements (gnat_node), Empty, + First_Real_Statement (gnat_node), true, true); + + /* Generate code for each statement in the block. */ + for (gnat_temp = (Present (First_Real_Statement (gnat_node)) + ? First_Real_Statement (gnat_node) + : First (Statements (gnat_node))); + Present (gnat_temp); gnat_temp = Next (gnat_temp)) + add_stmt (gnat_to_gnu (gnat_temp)); + gnu_inner_block = end_stmt_group (); + + /* Now generate code for the two exception models, if either is relevant for + this block. */ + if (setjmp_longjmp) + { + tree *gnu_else_ptr = 0; + tree gnu_handler; + + /* Make a binding level for the exception handling declarations and code + and set up gnu_except_ptr_stack for the handlers to use. */ + start_stmt_group (); + gnat_pushlevel (); + + vec_safe_push (gnu_except_ptr_stack, + create_var_decl (get_identifier ("EXCEPT_PTR"), NULL_TREE, + build_pointer_type (except_type_node), + build_call_n_expr (get_excptr_decl, 0), + false, false, false, false, + NULL, gnat_node)); + + /* Generate code for each handler. The N_Exception_Handler case does the + real work and returns a COND_EXPR for each handler, which we chain + together here. */ + for (gnat_temp = First_Non_Pragma (Exception_Handlers (gnat_node)); + Present (gnat_temp); gnat_temp = Next_Non_Pragma (gnat_temp)) + { + gnu_expr = gnat_to_gnu (gnat_temp); + + /* If this is the first one, set it as the outer one. Otherwise, + point the "else" part of the previous handler to us. Then point + to our "else" part. */ + if (!gnu_else_ptr) + add_stmt (gnu_expr); + else + *gnu_else_ptr = gnu_expr; + + gnu_else_ptr = &COND_EXPR_ELSE (gnu_expr); + } + + /* If none of the exception handlers did anything, re-raise but do not + defer abortion. */ + gnu_expr = build_call_n_expr (raise_nodefer_decl, 1, + gnu_except_ptr_stack->last ()); + set_expr_location_from_node + (gnu_expr, + Present (End_Label (gnat_node)) ? End_Label (gnat_node) : gnat_node); + + if (gnu_else_ptr) + *gnu_else_ptr = gnu_expr; + else + add_stmt (gnu_expr); + + /* End the binding level dedicated to the exception handlers and get the + whole statement group. */ + gnu_except_ptr_stack->pop (); + gnat_poplevel (); + gnu_handler = end_stmt_group (); + + /* If the setjmp returns 1, we restore our incoming longjmp value and + then check the handlers. */ + start_stmt_group (); + add_stmt_with_node (build_call_n_expr (set_jmpbuf_decl, 1, + gnu_jmpsave_decl), + gnat_node); + add_stmt (gnu_handler); + gnu_handler = end_stmt_group (); + + /* This block is now "if (setjmp) ... <handlers> else <block>". */ + gnu_result = build3 (COND_EXPR, void_type_node, + (build_call_n_expr + (setjmp_decl, 1, + build_unary_op (ADDR_EXPR, NULL_TREE, + gnu_jmpbuf_decl))), + gnu_handler, gnu_inner_block); + } + else if (gcc_zcx) + { + tree gnu_handlers; + location_t locus; + + /* First make a block containing the handlers. */ + start_stmt_group (); + for (gnat_temp = First_Non_Pragma (Exception_Handlers (gnat_node)); + Present (gnat_temp); + gnat_temp = Next_Non_Pragma (gnat_temp)) + add_stmt (gnat_to_gnu (gnat_temp)); + gnu_handlers = end_stmt_group (); + + /* Now make the TRY_CATCH_EXPR for the block. */ + gnu_result = build2 (TRY_CATCH_EXPR, void_type_node, + gnu_inner_block, gnu_handlers); + /* Set a location. We need to find a uniq location for the dispatching + code, otherwise we can get coverage or debugging issues. Try with + the location of the end label. */ + if (Present (End_Label (gnat_node)) + && Sloc_to_locus (Sloc (End_Label (gnat_node)), &locus)) + SET_EXPR_LOCATION (gnu_result, locus); + else + set_expr_location_from_node (gnu_result, gnat_node); + } + else + gnu_result = gnu_inner_block; + + /* Now close our outer block, if we had to make one. */ + if (binding_for_block) + { + add_stmt (gnu_result); + gnat_poplevel (); + gnu_result = end_stmt_group (); + } + + return gnu_result; +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler, + to a GCC tree, which is returned. This is the variant for Setjmp_Longjmp + exception handling. */ + +static tree +Exception_Handler_to_gnu_sjlj (Node_Id gnat_node) +{ + /* Unless this is "Others" or the special "Non-Ada" exception for Ada, make + an "if" statement to select the proper exceptions. For "Others", exclude + exceptions where Handled_By_Others is nonzero unless the All_Others flag + is set. For "Non-ada", accept an exception if "Lang" is 'V'. */ + tree gnu_choice = boolean_false_node; + tree gnu_body = build_stmt_group (Statements (gnat_node), false); + Node_Id gnat_temp; + + for (gnat_temp = First (Exception_Choices (gnat_node)); + gnat_temp; gnat_temp = Next (gnat_temp)) + { + tree this_choice; + + if (Nkind (gnat_temp) == N_Others_Choice) + { + if (All_Others (gnat_temp)) + this_choice = boolean_true_node; + else + this_choice + = build_binary_op + (EQ_EXPR, boolean_type_node, + convert + (integer_type_node, + build_component_ref + (build_unary_op + (INDIRECT_REF, NULL_TREE, + gnu_except_ptr_stack->last ()), + get_identifier ("not_handled_by_others"), NULL_TREE, + false)), + integer_zero_node); + } + + else if (Nkind (gnat_temp) == N_Identifier + || Nkind (gnat_temp) == N_Expanded_Name) + { + Entity_Id gnat_ex_id = Entity (gnat_temp); + tree gnu_expr; + + /* Exception may be a renaming. Recover original exception which is + the one elaborated and registered. */ + if (Present (Renamed_Object (gnat_ex_id))) + gnat_ex_id = Renamed_Object (gnat_ex_id); + + gnu_expr = gnat_to_gnu_entity (gnat_ex_id, NULL_TREE, 0); + + this_choice + = build_binary_op + (EQ_EXPR, boolean_type_node, + gnu_except_ptr_stack->last (), + convert (TREE_TYPE (gnu_except_ptr_stack->last ()), + build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr))); + + /* If this is the distinguished exception "Non_Ada_Error" (and we are + in VMS mode), also allow a non-Ada exception (a VMS condition) t + match. */ + if (Is_Non_Ada_Error (Entity (gnat_temp))) + { + tree gnu_comp + = build_component_ref + (build_unary_op (INDIRECT_REF, NULL_TREE, + gnu_except_ptr_stack->last ()), + get_identifier ("lang"), NULL_TREE, false); + + this_choice + = build_binary_op + (TRUTH_ORIF_EXPR, boolean_type_node, + build_binary_op (EQ_EXPR, boolean_type_node, gnu_comp, + build_int_cst (TREE_TYPE (gnu_comp), 'V')), + this_choice); + } + } + else + gcc_unreachable (); + + gnu_choice = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + gnu_choice, this_choice); + } + + return build3 (COND_EXPR, void_type_node, gnu_choice, gnu_body, NULL_TREE); +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler, + to a GCC tree, which is returned. This is the variant for ZCX. */ + +static tree +Exception_Handler_to_gnu_zcx (Node_Id gnat_node) +{ + tree gnu_etypes_list = NULL_TREE; + tree gnu_expr; + tree gnu_etype; + tree gnu_current_exc_ptr; + tree prev_gnu_incoming_exc_ptr; + Node_Id gnat_temp; + + /* We build a TREE_LIST of nodes representing what exception types this + handler can catch, with special cases for others and all others cases. + + Each exception type is actually identified by a pointer to the exception + id, or to a dummy object for "others" and "all others". */ + for (gnat_temp = First (Exception_Choices (gnat_node)); + gnat_temp; gnat_temp = Next (gnat_temp)) + { + if (Nkind (gnat_temp) == N_Others_Choice) + { + tree gnu_expr + = All_Others (gnat_temp) ? all_others_decl : others_decl; + + gnu_etype + = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr); + } + else if (Nkind (gnat_temp) == N_Identifier + || Nkind (gnat_temp) == N_Expanded_Name) + { + Entity_Id gnat_ex_id = Entity (gnat_temp); + + /* Exception may be a renaming. Recover original exception which is + the one elaborated and registered. */ + if (Present (Renamed_Object (gnat_ex_id))) + gnat_ex_id = Renamed_Object (gnat_ex_id); + + gnu_expr = gnat_to_gnu_entity (gnat_ex_id, NULL_TREE, 0); + gnu_etype = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_expr); + + /* The Non_Ada_Error case for VMS exceptions is handled + by the personality routine. */ + } + else + gcc_unreachable (); + + /* The GCC interface expects NULL to be passed for catch all handlers, so + it would be quite tempting to set gnu_etypes_list to NULL if gnu_etype + is integer_zero_node. It would not work, however, because GCC's + notion of "catch all" is stronger than our notion of "others". Until + we correctly use the cleanup interface as well, doing that would + prevent the "all others" handlers from being seen, because nothing + can be caught beyond a catch all from GCC's point of view. */ + gnu_etypes_list = tree_cons (NULL_TREE, gnu_etype, gnu_etypes_list); + } + + start_stmt_group (); + gnat_pushlevel (); + + /* Expand a call to the begin_handler hook at the beginning of the handler, + and arrange for a call to the end_handler hook to occur on every possible + exit path. + + The hooks expect a pointer to the low level occurrence. This is required + for our stack management scheme because a raise inside the handler pushes + a new occurrence on top of the stack, which means that this top does not + necessarily match the occurrence this handler was dealing with. + + __builtin_eh_pointer references the exception occurrence being + propagated. Upon handler entry, this is the exception for which the + handler is triggered. This might not be the case upon handler exit, + however, as we might have a new occurrence propagated by the handler's + body, and the end_handler hook called as a cleanup in this context. + + We use a local variable to retrieve the incoming value at handler entry + time, and reuse it to feed the end_handler hook's argument at exit. */ + + gnu_current_exc_ptr + = build_call_expr (builtin_decl_explicit (BUILT_IN_EH_POINTER), + 1, integer_zero_node); + prev_gnu_incoming_exc_ptr = gnu_incoming_exc_ptr; + gnu_incoming_exc_ptr = create_var_decl (get_identifier ("EXPTR"), NULL_TREE, + ptr_type_node, gnu_current_exc_ptr, + false, false, false, false, + NULL, gnat_node); + + add_stmt_with_node (build_call_n_expr (begin_handler_decl, 1, + gnu_incoming_exc_ptr), + gnat_node); + /* ??? We don't seem to have an End_Label at hand to set the location. */ + add_cleanup (build_call_n_expr (end_handler_decl, 1, gnu_incoming_exc_ptr), + Empty); + add_stmt_list (Statements (gnat_node)); + gnat_poplevel (); + + gnu_incoming_exc_ptr = prev_gnu_incoming_exc_ptr; + + return build2 (CATCH_EXPR, void_type_node, gnu_etypes_list, + end_stmt_group ()); +} + +/* Subroutine of gnat_to_gnu to generate code for an N_Compilation unit. */ + +static void +Compilation_Unit_to_gnu (Node_Id gnat_node) +{ + const Node_Id gnat_unit = Unit (gnat_node); + const bool body_p = (Nkind (gnat_unit) == N_Package_Body + || Nkind (gnat_unit) == N_Subprogram_Body); + const Entity_Id gnat_unit_entity = Defining_Entity (gnat_unit); + Node_Id gnat_pragma; + /* Make the decl for the elaboration procedure. */ + tree gnu_elab_proc_decl + = create_subprog_decl + (create_concat_name (gnat_unit_entity, body_p ? "elabb" : "elabs"), + NULL_TREE, void_ftype, NULL_TREE, false, true, false, true, NULL, + gnat_unit); + struct elab_info *info; + + vec_safe_push (gnu_elab_proc_stack, gnu_elab_proc_decl); + DECL_ELABORATION_PROC_P (gnu_elab_proc_decl) = 1; + + /* Initialize the information structure for the function. */ + allocate_struct_function (gnu_elab_proc_decl, false); + set_cfun (NULL); + + current_function_decl = NULL_TREE; + + start_stmt_group (); + gnat_pushlevel (); + + /* For a body, first process the spec if there is one. */ + if (Nkind (gnat_unit) == N_Package_Body + || (Nkind (gnat_unit) == N_Subprogram_Body && !Acts_As_Spec (gnat_node))) + add_stmt (gnat_to_gnu (Library_Unit (gnat_node))); + + if (type_annotate_only && gnat_node == Cunit (Main_Unit)) + { + elaborate_all_entities (gnat_node); + + if (Nkind (gnat_unit) == N_Subprogram_Declaration + || Nkind (gnat_unit) == N_Generic_Package_Declaration + || Nkind (gnat_unit) == N_Generic_Subprogram_Declaration) + return; + } + + /* Then process any pragmas and declarations preceding the unit. */ + for (gnat_pragma = First (Context_Items (gnat_node)); + Present (gnat_pragma); + gnat_pragma = Next (gnat_pragma)) + if (Nkind (gnat_pragma) == N_Pragma) + add_stmt (gnat_to_gnu (gnat_pragma)); + process_decls (Declarations (Aux_Decls_Node (gnat_node)), Empty, Empty, + true, true); + + /* Process the unit itself. */ + add_stmt (gnat_to_gnu (gnat_unit)); + + /* If we can inline, generate code for all the inlined subprograms. */ + if (optimize) + { + Entity_Id gnat_entity; + + for (gnat_entity = First_Inlined_Subprogram (gnat_node); + Present (gnat_entity); + gnat_entity = Next_Inlined_Subprogram (gnat_entity)) + { + Node_Id gnat_body = Parent (Declaration_Node (gnat_entity)); + + if (Nkind (gnat_body) != N_Subprogram_Body) + { + /* ??? This really should always be present. */ + if (No (Corresponding_Body (gnat_body))) + continue; + gnat_body + = Parent (Declaration_Node (Corresponding_Body (gnat_body))); + } + + if (Present (gnat_body)) + { + /* Define the entity first so we set DECL_EXTERNAL. */ + gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0); + add_stmt (gnat_to_gnu (gnat_body)); + } + } + } + + /* Process any pragmas and actions following the unit. */ + add_stmt_list (Pragmas_After (Aux_Decls_Node (gnat_node))); + add_stmt_list (Actions (Aux_Decls_Node (gnat_node))); + finalize_from_with_types (); + + /* Save away what we've made so far and record this potential elaboration + procedure. */ + info = ggc_alloc_elab_info (); + set_current_block_context (gnu_elab_proc_decl); + gnat_poplevel (); + DECL_SAVED_TREE (gnu_elab_proc_decl) = end_stmt_group (); + + set_end_locus_from_node (gnu_elab_proc_decl, gnat_unit); + + info->next = elab_info_list; + info->elab_proc = gnu_elab_proc_decl; + info->gnat_node = gnat_node; + elab_info_list = info; + + /* Generate elaboration code for this unit, if necessary, and say whether + we did or not. */ + gnu_elab_proc_stack->pop (); + + /* Invalidate the global renaming pointers. This is necessary because + stabilization of the renamed entities may create SAVE_EXPRs which + have been tied to a specific elaboration routine just above. */ + invalidate_global_renaming_pointers (); +} + +/* Subroutine of gnat_to_gnu to translate gnat_node, an N_Raise_xxx_Error, + to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to where + we should place the result type. LABEL_P is true if there is a label to + branch to for the exception. */ + +static tree +Raise_Error_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p) +{ + const Node_Kind kind = Nkind (gnat_node); + const int reason = UI_To_Int (Reason (gnat_node)); + const Node_Id gnat_cond = Condition (gnat_node); + const bool with_extra_info + = Exception_Extra_Info + && !No_Exception_Handlers_Set () + && !get_exception_label (kind); + tree gnu_result = NULL_TREE, gnu_cond = NULL_TREE; + + *gnu_result_type_p = get_unpadded_type (Etype (gnat_node)); + + switch (reason) + { + case CE_Access_Check_Failed: + if (with_extra_info) + gnu_result = build_call_raise_column (reason, gnat_node); + break; + + case CE_Index_Check_Failed: + case CE_Range_Check_Failed: + case CE_Invalid_Data: + if (Present (gnat_cond) && Nkind (gnat_cond) == N_Op_Not) + { + Node_Id gnat_range, gnat_index, gnat_type; + tree gnu_index, gnu_low_bound, gnu_high_bound; + struct range_check_info_d *rci; + + switch (Nkind (Right_Opnd (gnat_cond))) + { + case N_In: + gnat_range = Right_Opnd (Right_Opnd (gnat_cond)); + gcc_assert (Nkind (gnat_range) == N_Range); + gnu_low_bound = gnat_to_gnu (Low_Bound (gnat_range)); + gnu_high_bound = gnat_to_gnu (High_Bound (gnat_range)); + break; + + case N_Op_Ge: + gnu_low_bound = gnat_to_gnu (Right_Opnd (Right_Opnd (gnat_cond))); + gnu_high_bound = NULL_TREE; + break; + + case N_Op_Le: + gnu_low_bound = NULL_TREE; + gnu_high_bound = gnat_to_gnu (Right_Opnd (Right_Opnd (gnat_cond))); + break; + + default: + goto common; + } + + gnat_index = Left_Opnd (Right_Opnd (gnat_cond)); + gnat_type = Etype (gnat_index); + gnu_index = gnat_to_gnu (gnat_index); + + if (with_extra_info + && gnu_low_bound + && gnu_high_bound + && Known_Esize (gnat_type) + && UI_To_Int (Esize (gnat_type)) <= 32) + gnu_result + = build_call_raise_range (reason, gnat_node, gnu_index, + gnu_low_bound, gnu_high_bound); + + /* If loop unswitching is enabled, we try to compute invariant + conditions for checks applied to iteration variables, i.e. + conditions that are both independent of the variable and + necessary in order for the check to fail in the course of + some iteration, and prepend them to the original condition + of the checks. This will make it possible later for the + loop unswitching pass to replace the loop with two loops, + one of which has the checks eliminated and the other has + the original checks reinstated, and a run time selection. + The former loop will be suitable for vectorization. */ + if (flag_unswitch_loops + && (!gnu_low_bound + || (gnu_low_bound = gnat_invariant_expr (gnu_low_bound))) + && (!gnu_high_bound + || (gnu_high_bound = gnat_invariant_expr (gnu_high_bound))) + && (rci = push_range_check_info (gnu_index))) + { + rci->low_bound = gnu_low_bound; + rci->high_bound = gnu_high_bound; + rci->type = get_unpadded_type (gnat_type); + rci->invariant_cond = build1 (SAVE_EXPR, boolean_type_node, + boolean_true_node); + gnu_cond = build_binary_op (TRUTH_ANDIF_EXPR, + boolean_type_node, + rci->invariant_cond, + gnat_to_gnu (gnat_cond)); + } + } + break; + + default: + break; + } + +common: + if (!gnu_result) + gnu_result = build_call_raise (reason, gnat_node, kind); + set_expr_location_from_node (gnu_result, gnat_node); + + /* If the type is VOID, this is a statement, so we need to generate the code + for the call. Handle a condition, if there is one. */ + if (VOID_TYPE_P (*gnu_result_type_p)) + { + if (Present (gnat_cond)) + { + if (!gnu_cond) + gnu_cond = gnat_to_gnu (gnat_cond); + gnu_result = build3 (COND_EXPR, void_type_node, gnu_cond, gnu_result, + alloc_stmt_list ()); + } + } + else + gnu_result = build1 (NULL_EXPR, *gnu_result_type_p, gnu_result); + + return gnu_result; +} + +/* Return true if GNAT_NODE is on the LHS of an assignment or an actual + parameter of a call. */ + +static bool +lhs_or_actual_p (Node_Id gnat_node) +{ + Node_Id gnat_parent = Parent (gnat_node); + Node_Kind kind = Nkind (gnat_parent); + + if (kind == N_Assignment_Statement && Name (gnat_parent) == gnat_node) + return true; + + if ((kind == N_Procedure_Call_Statement || kind == N_Function_Call) + && Name (gnat_parent) != gnat_node) + return true; + + if (kind == N_Parameter_Association) + return true; + + return false; +} + +/* Return true if either GNAT_NODE or a view of GNAT_NODE is on the LHS + of an assignment or an actual parameter of a call. */ + +static bool +present_in_lhs_or_actual_p (Node_Id gnat_node) +{ + Node_Kind kind; + + if (lhs_or_actual_p (gnat_node)) + return true; + + kind = Nkind (Parent (gnat_node)); + + if ((kind == N_Type_Conversion || kind == N_Unchecked_Type_Conversion) + && lhs_or_actual_p (Parent (gnat_node))) + return true; + + return false; +} + +/* Return true if GNAT_NODE, an unchecked type conversion, is a no-op as far + as gigi is concerned. This is used to avoid conversions on the LHS. */ + +static bool +unchecked_conversion_nop (Node_Id gnat_node) +{ + Entity_Id from_type, to_type; + + /* The conversion must be on the LHS of an assignment or an actual parameter + of a call. Otherwise, even if the conversion was essentially a no-op, it + could de facto ensure type consistency and this should be preserved. */ + if (!lhs_or_actual_p (gnat_node)) + return false; + + from_type = Etype (Expression (gnat_node)); + + /* We're interested in artificial conversions generated by the front-end + to make private types explicit, e.g. in Expand_Assign_Array. */ + if (!Is_Private_Type (from_type)) + return false; + + from_type = Underlying_Type (from_type); + to_type = Etype (gnat_node); + + /* The direct conversion to the underlying type is a no-op. */ + if (to_type == from_type) + return true; + + /* For an array subtype, the conversion to the PAT is a no-op. */ + if (Ekind (from_type) == E_Array_Subtype + && to_type == Packed_Array_Type (from_type)) + return true; + + /* For a record subtype, the conversion to the type is a no-op. */ + if (Ekind (from_type) == E_Record_Subtype + && to_type == Etype (from_type)) + return true; + + return false; +} + +/* This function is the driver of the GNAT to GCC tree transformation process. + It is the entry point of the tree transformer. GNAT_NODE is the root of + some GNAT tree. Return the root of the corresponding GCC tree. If this + is an expression, return the GCC equivalent of the expression. If this + is a statement, return the statement or add it to the current statement + group, in which case anything returned is to be interpreted as occurring + after anything added. */ + +tree +gnat_to_gnu (Node_Id gnat_node) +{ + const Node_Kind kind = Nkind (gnat_node); + bool went_into_elab_proc = false; + tree gnu_result = error_mark_node; /* Default to no value. */ + tree gnu_result_type = void_type_node; + tree gnu_expr, gnu_lhs, gnu_rhs; + Node_Id gnat_temp; + + /* Save node number for error message and set location information. */ + error_gnat_node = gnat_node; + Sloc_to_locus (Sloc (gnat_node), &input_location); + + /* If this node is a statement and we are only annotating types, return an + empty statement list. */ + if (type_annotate_only && IN (kind, N_Statement_Other_Than_Procedure_Call)) + return alloc_stmt_list (); + + /* If this node is a non-static subexpression and we are only annotating + types, make this into a NULL_EXPR. */ + if (type_annotate_only + && IN (kind, N_Subexpr) + && kind != N_Identifier + && !Compile_Time_Known_Value (gnat_node)) + return build1 (NULL_EXPR, get_unpadded_type (Etype (gnat_node)), + build_call_raise (CE_Range_Check_Failed, gnat_node, + N_Raise_Constraint_Error)); + + if ((IN (kind, N_Statement_Other_Than_Procedure_Call) + && kind != N_Null_Statement) + || kind == N_Procedure_Call_Statement + || kind == N_Label + || kind == N_Implicit_Label_Declaration + || kind == N_Handled_Sequence_Of_Statements + || (IN (kind, N_Raise_xxx_Error) && Ekind (Etype (gnat_node)) == E_Void)) + { + tree current_elab_proc = get_elaboration_procedure (); + + /* If this is a statement and we are at top level, it must be part of + the elaboration procedure, so mark us as being in that procedure. */ + if (!current_function_decl) + { + current_function_decl = current_elab_proc; + went_into_elab_proc = true; + } + + /* If we are in the elaboration procedure, check if we are violating a + No_Elaboration_Code restriction by having a statement there. Don't + check for a possible No_Elaboration_Code restriction violation on + N_Handled_Sequence_Of_Statements, as we want to signal an error on + every nested real statement instead. This also avoids triggering + spurious errors on dummy (empty) sequences created by the front-end + for package bodies in some cases. */ + if (current_function_decl == current_elab_proc + && kind != N_Handled_Sequence_Of_Statements) + Check_Elaboration_Code_Allowed (gnat_node); + } + + switch (kind) + { + /********************************/ + /* Chapter 2: Lexical Elements */ + /********************************/ + + case N_Identifier: + case N_Expanded_Name: + case N_Operator_Symbol: + case N_Defining_Identifier: + gnu_result = Identifier_to_gnu (gnat_node, &gnu_result_type); + + /* If this is an atomic access on the RHS for which synchronization is + required, build the atomic load. */ + if (atomic_sync_required_p (gnat_node) + && !present_in_lhs_or_actual_p (gnat_node)) + gnu_result = build_atomic_load (gnu_result); + break; + + case N_Integer_Literal: + { + tree gnu_type; + + /* Get the type of the result, looking inside any padding and + justified modular types. Then get the value in that type. */ + gnu_type = gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + if (TREE_CODE (gnu_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_type)) + gnu_type = TREE_TYPE (TYPE_FIELDS (gnu_type)); + + gnu_result = UI_To_gnu (Intval (gnat_node), gnu_type); + + /* If the result overflows (meaning it doesn't fit in its base type), + abort. We would like to check that the value is within the range + of the subtype, but that causes problems with subtypes whose usage + will raise Constraint_Error and with biased representation, so + we don't. */ + gcc_assert (!TREE_OVERFLOW (gnu_result)); + } + break; + + case N_Character_Literal: + /* If a Entity is present, it means that this was one of the + literals in a user-defined character type. In that case, + just return the value in the CONST_DECL. Otherwise, use the + character code. In that case, the base type should be an + INTEGER_TYPE, but we won't bother checking for that. */ + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + if (Present (Entity (gnat_node))) + gnu_result = DECL_INITIAL (get_gnu_tree (Entity (gnat_node))); + else + gnu_result + = build_int_cst_type + (gnu_result_type, UI_To_CC (Char_Literal_Value (gnat_node))); + break; + + case N_Real_Literal: + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is of a fixed-point type, the value we want is the + value of the corresponding integer. */ + if (IN (Ekind (Underlying_Type (Etype (gnat_node))), Fixed_Point_Kind)) + { + gnu_result = UI_To_gnu (Corresponding_Integer_Value (gnat_node), + gnu_result_type); + gcc_assert (!TREE_OVERFLOW (gnu_result)); + } + + /* Convert the Ureal to a vax float (represented on a signed type). */ + else if (Vax_Float (Underlying_Type (Etype (gnat_node)))) + { + gnu_result = UI_To_gnu (Get_Vax_Real_Literal_As_Signed (gnat_node), + gnu_result_type); + } + + else + { + Ureal ur_realval = Realval (gnat_node); + + /* First convert the real value to a machine number if it isn't + already. That forces BASE to 2 for non-zero values and simplifies + the rest of our logic. */ + + if (!Is_Machine_Number (gnat_node)) + ur_realval + = Machine (Base_Type (Underlying_Type (Etype (gnat_node))), + ur_realval, Round_Even, gnat_node); + + if (UR_Is_Zero (ur_realval)) + gnu_result = convert (gnu_result_type, integer_zero_node); + else + { + REAL_VALUE_TYPE tmp; + + gnu_result + = UI_To_gnu (Numerator (ur_realval), gnu_result_type); + + /* The base must be 2 as Machine guarantees this, so we scale + the value, which we know can fit in the mantissa of the type + (hence the use of that type above). */ + + gcc_assert (Rbase (ur_realval) == 2); + real_ldexp (&tmp, &TREE_REAL_CST (gnu_result), + - UI_To_Int (Denominator (ur_realval))); + gnu_result = build_real (gnu_result_type, tmp); + } + + /* Now see if we need to negate the result. Do it this way to + properly handle -0. */ + if (UR_Is_Negative (Realval (gnat_node))) + gnu_result + = build_unary_op (NEGATE_EXPR, get_base_type (gnu_result_type), + gnu_result); + } + + break; + + case N_String_Literal: + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + if (TYPE_PRECISION (TREE_TYPE (gnu_result_type)) == HOST_BITS_PER_CHAR) + { + String_Id gnat_string = Strval (gnat_node); + int length = String_Length (gnat_string); + int i; + char *string; + if (length >= ALLOCA_THRESHOLD) + string = XNEWVEC (char, length + 1); + else + string = (char *) alloca (length + 1); + + /* Build the string with the characters in the literal. Note + that Ada strings are 1-origin. */ + for (i = 0; i < length; i++) + string[i] = Get_String_Char (gnat_string, i + 1); + + /* Put a null at the end of the string in case it's in a context + where GCC will want to treat it as a C string. */ + string[i] = 0; + + gnu_result = build_string (length, string); + + /* Strings in GCC don't normally have types, but we want + this to not be converted to the array type. */ + TREE_TYPE (gnu_result) = gnu_result_type; + + if (length >= ALLOCA_THRESHOLD) + free (string); + } + else + { + /* Build a list consisting of each character, then make + the aggregate. */ + String_Id gnat_string = Strval (gnat_node); + int length = String_Length (gnat_string); + int i; + tree gnu_idx = TYPE_MIN_VALUE (TYPE_DOMAIN (gnu_result_type)); + vec<constructor_elt, va_gc> *gnu_vec; + vec_alloc (gnu_vec, length); + + for (i = 0; i < length; i++) + { + tree t = build_int_cst (TREE_TYPE (gnu_result_type), + Get_String_Char (gnat_string, i + 1)); + + CONSTRUCTOR_APPEND_ELT (gnu_vec, gnu_idx, t); + gnu_idx = int_const_binop (PLUS_EXPR, gnu_idx, integer_one_node); + } + + gnu_result = gnat_build_constructor (gnu_result_type, gnu_vec); + } + break; + + case N_Pragma: + gnu_result = Pragma_to_gnu (gnat_node); + break; + + /**************************************/ + /* Chapter 3: Declarations and Types */ + /**************************************/ + + case N_Subtype_Declaration: + case N_Full_Type_Declaration: + case N_Incomplete_Type_Declaration: + case N_Private_Type_Declaration: + case N_Private_Extension_Declaration: + case N_Task_Type_Declaration: + process_type (Defining_Entity (gnat_node)); + gnu_result = alloc_stmt_list (); + break; + + case N_Object_Declaration: + case N_Exception_Declaration: + gnat_temp = Defining_Entity (gnat_node); + gnu_result = alloc_stmt_list (); + + /* If we are just annotating types and this object has an unconstrained + or task type, don't elaborate it. */ + if (type_annotate_only + && (((Is_Array_Type (Etype (gnat_temp)) + || Is_Record_Type (Etype (gnat_temp))) + && !Is_Constrained (Etype (gnat_temp))) + || Is_Concurrent_Type (Etype (gnat_temp)))) + break; + + if (Present (Expression (gnat_node)) + && !(kind == N_Object_Declaration && No_Initialization (gnat_node)) + && (!type_annotate_only + || Compile_Time_Known_Value (Expression (gnat_node)))) + { + gnu_expr = gnat_to_gnu (Expression (gnat_node)); + if (Do_Range_Check (Expression (gnat_node))) + gnu_expr + = emit_range_check (gnu_expr, Etype (gnat_temp), gnat_node); + + /* If this object has its elaboration delayed, we must force + evaluation of GNU_EXPR right now and save it for when the object + is frozen. */ + if (Present (Freeze_Node (gnat_temp))) + { + if (TREE_CONSTANT (gnu_expr)) + ; + else if (global_bindings_p ()) + gnu_expr + = create_var_decl (create_concat_name (gnat_temp, "init"), + NULL_TREE, TREE_TYPE (gnu_expr), gnu_expr, + false, false, false, false, + NULL, gnat_temp); + else + gnu_expr = gnat_save_expr (gnu_expr); + + save_gnu_tree (gnat_node, gnu_expr, true); + } + } + else + gnu_expr = NULL_TREE; + + if (type_annotate_only && gnu_expr && TREE_CODE (gnu_expr) == ERROR_MARK) + gnu_expr = NULL_TREE; + + /* If this is a deferred constant with an address clause, we ignore the + full view since the clause is on the partial view and we cannot have + 2 different GCC trees for the object. The only bits of the full view + we will use is the initializer, but it will be directly fetched. */ + if (Ekind(gnat_temp) == E_Constant + && Present (Address_Clause (gnat_temp)) + && Present (Full_View (gnat_temp))) + save_gnu_tree (Full_View (gnat_temp), error_mark_node, true); + + if (No (Freeze_Node (gnat_temp))) + gnat_to_gnu_entity (gnat_temp, gnu_expr, 1); + break; + + case N_Object_Renaming_Declaration: + gnat_temp = Defining_Entity (gnat_node); + + /* Don't do anything if this renaming is handled by the front end or if + we are just annotating types and this object has a composite or task + type, don't elaborate it. We return the result in case it has any + SAVE_EXPRs in it that need to be evaluated here. */ + if (!Is_Renaming_Of_Object (gnat_temp) + && ! (type_annotate_only + && (Is_Array_Type (Etype (gnat_temp)) + || Is_Record_Type (Etype (gnat_temp)) + || Is_Concurrent_Type (Etype (gnat_temp))))) + gnu_result + = gnat_to_gnu_entity (gnat_temp, + gnat_to_gnu (Renamed_Object (gnat_temp)), 1); + else + gnu_result = alloc_stmt_list (); + break; + + case N_Implicit_Label_Declaration: + gnat_to_gnu_entity (Defining_Entity (gnat_node), NULL_TREE, 1); + gnu_result = alloc_stmt_list (); + break; + + case N_Exception_Renaming_Declaration: + case N_Number_Declaration: + case N_Package_Renaming_Declaration: + case N_Subprogram_Renaming_Declaration: + /* These are fully handled in the front end. */ + gnu_result = alloc_stmt_list (); + break; + + /*************************************/ + /* Chapter 4: Names and Expressions */ + /*************************************/ + + case N_Explicit_Dereference: + gnu_result = gnat_to_gnu (Prefix (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = build_unary_op (INDIRECT_REF, NULL_TREE, gnu_result); + + /* If this is an atomic access on the RHS for which synchronization is + required, build the atomic load. */ + if (atomic_sync_required_p (gnat_node) + && !present_in_lhs_or_actual_p (gnat_node)) + gnu_result = build_atomic_load (gnu_result); + break; + + case N_Indexed_Component: + { + tree gnu_array_object = gnat_to_gnu (Prefix (gnat_node)); + tree gnu_type; + int ndim; + int i; + Node_Id *gnat_expr_array; + + gnu_array_object = maybe_implicit_deref (gnu_array_object); + + /* Convert vector inputs to their representative array type, to fit + what the code below expects. */ + if (VECTOR_TYPE_P (TREE_TYPE (gnu_array_object))) + { + if (present_in_lhs_or_actual_p (gnat_node)) + gnat_mark_addressable (gnu_array_object); + gnu_array_object = maybe_vector_array (gnu_array_object); + } + + gnu_array_object = maybe_unconstrained_array (gnu_array_object); + + /* If we got a padded type, remove it too. */ + if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_array_object))) + gnu_array_object + = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_array_object))), + gnu_array_object); + + gnu_result = gnu_array_object; + + /* The failure of this assertion will very likely come from a missing + expansion for a packed array access. */ + gcc_assert (TREE_CODE (TREE_TYPE (gnu_array_object)) == ARRAY_TYPE); + + /* First compute the number of dimensions of the array, then + fill the expression array, the order depending on whether + this is a Convention_Fortran array or not. */ + for (ndim = 1, gnu_type = TREE_TYPE (gnu_array_object); + TREE_CODE (TREE_TYPE (gnu_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_type)); + ndim++, gnu_type = TREE_TYPE (gnu_type)) + ; + + gnat_expr_array = XALLOCAVEC (Node_Id, ndim); + + if (TYPE_CONVENTION_FORTRAN_P (TREE_TYPE (gnu_array_object))) + for (i = ndim - 1, gnat_temp = First (Expressions (gnat_node)); + i >= 0; + i--, gnat_temp = Next (gnat_temp)) + gnat_expr_array[i] = gnat_temp; + else + for (i = 0, gnat_temp = First (Expressions (gnat_node)); + i < ndim; + i++, gnat_temp = Next (gnat_temp)) + gnat_expr_array[i] = gnat_temp; + + for (i = 0, gnu_type = TREE_TYPE (gnu_array_object); + i < ndim; i++, gnu_type = TREE_TYPE (gnu_type)) + { + gcc_assert (TREE_CODE (gnu_type) == ARRAY_TYPE); + gnat_temp = gnat_expr_array[i]; + gnu_expr = gnat_to_gnu (gnat_temp); + + if (Do_Range_Check (gnat_temp)) + gnu_expr + = emit_index_check + (gnu_array_object, gnu_expr, + TYPE_MIN_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type))), + TYPE_MAX_VALUE (TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type))), + gnat_temp); + + gnu_result = build_binary_op (ARRAY_REF, NULL_TREE, + gnu_result, gnu_expr); + } + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is an atomic access on the RHS for which synchronization is + required, build the atomic load. */ + if (atomic_sync_required_p (gnat_node) + && !present_in_lhs_or_actual_p (gnat_node)) + gnu_result = build_atomic_load (gnu_result); + } + break; + + case N_Slice: + { + Node_Id gnat_range_node = Discrete_Range (gnat_node); + tree gnu_type; + + gnu_result = gnat_to_gnu (Prefix (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* Do any implicit dereferences of the prefix and do any needed + range check. */ + gnu_result = maybe_implicit_deref (gnu_result); + gnu_result = maybe_unconstrained_array (gnu_result); + gnu_type = TREE_TYPE (gnu_result); + if (Do_Range_Check (gnat_range_node)) + { + /* Get the bounds of the slice. */ + tree gnu_index_type + = TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_result_type)); + tree gnu_min_expr = TYPE_MIN_VALUE (gnu_index_type); + tree gnu_max_expr = TYPE_MAX_VALUE (gnu_index_type); + /* Get the permitted bounds. */ + tree gnu_base_index_type + = TYPE_INDEX_TYPE (TYPE_DOMAIN (gnu_type)); + tree gnu_base_min_expr = SUBSTITUTE_PLACEHOLDER_IN_EXPR + (TYPE_MIN_VALUE (gnu_base_index_type), gnu_result); + tree gnu_base_max_expr = SUBSTITUTE_PLACEHOLDER_IN_EXPR + (TYPE_MAX_VALUE (gnu_base_index_type), gnu_result); + tree gnu_expr_l, gnu_expr_h, gnu_expr_type; + + gnu_min_expr = gnat_protect_expr (gnu_min_expr); + gnu_max_expr = gnat_protect_expr (gnu_max_expr); + + /* Derive a good type to convert everything to. */ + gnu_expr_type = get_base_type (gnu_index_type); + + /* Test whether the minimum slice value is too small. */ + gnu_expr_l = build_binary_op (LT_EXPR, boolean_type_node, + convert (gnu_expr_type, + gnu_min_expr), + convert (gnu_expr_type, + gnu_base_min_expr)); + + /* Test whether the maximum slice value is too large. */ + gnu_expr_h = build_binary_op (GT_EXPR, boolean_type_node, + convert (gnu_expr_type, + gnu_max_expr), + convert (gnu_expr_type, + gnu_base_max_expr)); + + /* Build a slice index check that returns the low bound, + assuming the slice is not empty. */ + gnu_expr = emit_check + (build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + gnu_expr_l, gnu_expr_h), + gnu_min_expr, CE_Index_Check_Failed, gnat_node); + + /* Build a conditional expression that does the index checks and + returns the low bound if the slice is not empty (max >= min), + and returns the naked low bound otherwise (max < min), unless + it is non-constant and the high bound is; this prevents VRP + from inferring bogus ranges on the unlikely path. */ + gnu_expr = fold_build3 (COND_EXPR, gnu_expr_type, + build_binary_op (GE_EXPR, gnu_expr_type, + convert (gnu_expr_type, + gnu_max_expr), + convert (gnu_expr_type, + gnu_min_expr)), + gnu_expr, + TREE_CODE (gnu_min_expr) != INTEGER_CST + && TREE_CODE (gnu_max_expr) == INTEGER_CST + ? gnu_max_expr : gnu_min_expr); + } + else + /* Simply return the naked low bound. */ + gnu_expr = TYPE_MIN_VALUE (TYPE_DOMAIN (gnu_result_type)); + + /* If this is a slice with non-constant size of an array with constant + size, set the maximum size for the allocation of temporaries. */ + if (!TREE_CONSTANT (TYPE_SIZE_UNIT (gnu_result_type)) + && TREE_CONSTANT (TYPE_SIZE_UNIT (gnu_type))) + TYPE_ARRAY_MAX_SIZE (gnu_result_type) = TYPE_SIZE_UNIT (gnu_type); + + gnu_result = build_binary_op (ARRAY_RANGE_REF, gnu_result_type, + gnu_result, gnu_expr); + } + break; + + case N_Selected_Component: + { + tree gnu_prefix = gnat_to_gnu (Prefix (gnat_node)); + Entity_Id gnat_field = Entity (Selector_Name (gnat_node)); + Entity_Id gnat_pref_type = Etype (Prefix (gnat_node)); + tree gnu_field; + + while (IN (Ekind (gnat_pref_type), Incomplete_Or_Private_Kind) + || IN (Ekind (gnat_pref_type), Access_Kind)) + { + if (IN (Ekind (gnat_pref_type), Incomplete_Or_Private_Kind)) + gnat_pref_type = Underlying_Type (gnat_pref_type); + else if (IN (Ekind (gnat_pref_type), Access_Kind)) + gnat_pref_type = Designated_Type (gnat_pref_type); + } + + gnu_prefix = maybe_implicit_deref (gnu_prefix); + + /* For discriminant references in tagged types always substitute the + corresponding discriminant as the actual selected component. */ + if (Is_Tagged_Type (gnat_pref_type)) + while (Present (Corresponding_Discriminant (gnat_field))) + gnat_field = Corresponding_Discriminant (gnat_field); + + /* For discriminant references of untagged types always substitute the + corresponding stored discriminant. */ + else if (Present (Corresponding_Discriminant (gnat_field))) + gnat_field = Original_Record_Component (gnat_field); + + /* Handle extracting the real or imaginary part of a complex. + The real part is the first field and the imaginary the last. */ + if (TREE_CODE (TREE_TYPE (gnu_prefix)) == COMPLEX_TYPE) + gnu_result = build_unary_op (Present (Next_Entity (gnat_field)) + ? REALPART_EXPR : IMAGPART_EXPR, + NULL_TREE, gnu_prefix); + else + { + gnu_field = gnat_to_gnu_field_decl (gnat_field); + + /* If there are discriminants, the prefix might be evaluated more + than once, which is a problem if it has side-effects. */ + if (Has_Discriminants (Is_Access_Type (Etype (Prefix (gnat_node))) + ? Designated_Type (Etype + (Prefix (gnat_node))) + : Etype (Prefix (gnat_node)))) + gnu_prefix = gnat_stabilize_reference (gnu_prefix, false, NULL); + + gnu_result + = build_component_ref (gnu_prefix, NULL_TREE, gnu_field, + (Nkind (Parent (gnat_node)) + == N_Attribute_Reference) + && lvalue_required_for_attribute_p + (Parent (gnat_node))); + } + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is an atomic access on the RHS for which synchronization is + required, build the atomic load. */ + if (atomic_sync_required_p (gnat_node) + && !present_in_lhs_or_actual_p (gnat_node)) + gnu_result = build_atomic_load (gnu_result); + } + break; + + case N_Attribute_Reference: + { + /* The attribute designator. */ + const int attr = Get_Attribute_Id (Attribute_Name (gnat_node)); + + /* The Elab_Spec and Elab_Body attributes are special in that Prefix + is a unit, not an object with a GCC equivalent. */ + if (attr == Attr_Elab_Spec || attr == Attr_Elab_Body) + return + create_subprog_decl (create_concat_name + (Entity (Prefix (gnat_node)), + attr == Attr_Elab_Body ? "elabb" : "elabs"), + NULL_TREE, void_ftype, NULL_TREE, false, + true, true, true, NULL, gnat_node); + + gnu_result = Attribute_to_gnu (gnat_node, &gnu_result_type, attr); + } + break; + + case N_Reference: + /* Like 'Access as far as we are concerned. */ + gnu_result = gnat_to_gnu (Prefix (gnat_node)); + gnu_result = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_result); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case N_Aggregate: + case N_Extension_Aggregate: + { + tree gnu_aggr_type; + + /* ??? It is wrong to evaluate the type now, but there doesn't + seem to be any other practical way of doing it. */ + + gcc_assert (!Expansion_Delayed (gnat_node)); + + gnu_aggr_type = gnu_result_type + = get_unpadded_type (Etype (gnat_node)); + + if (TREE_CODE (gnu_result_type) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (gnu_result_type)) + gnu_aggr_type + = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (gnu_result_type))); + else if (TREE_CODE (gnu_result_type) == VECTOR_TYPE) + gnu_aggr_type = TYPE_REPRESENTATIVE_ARRAY (gnu_result_type); + + if (Null_Record_Present (gnat_node)) + gnu_result = gnat_build_constructor (gnu_aggr_type, + NULL); + + else if (TREE_CODE (gnu_aggr_type) == RECORD_TYPE + || TREE_CODE (gnu_aggr_type) == UNION_TYPE) + gnu_result + = assoc_to_constructor (Etype (gnat_node), + First (Component_Associations (gnat_node)), + gnu_aggr_type); + else if (TREE_CODE (gnu_aggr_type) == ARRAY_TYPE) + gnu_result = pos_to_constructor (First (Expressions (gnat_node)), + gnu_aggr_type, + Component_Type (Etype (gnat_node))); + else if (TREE_CODE (gnu_aggr_type) == COMPLEX_TYPE) + gnu_result + = build_binary_op + (COMPLEX_EXPR, gnu_aggr_type, + gnat_to_gnu (Expression (First + (Component_Associations (gnat_node)))), + gnat_to_gnu (Expression + (Next + (First (Component_Associations (gnat_node)))))); + else + gcc_unreachable (); + + gnu_result = convert (gnu_result_type, gnu_result); + } + break; + + case N_Null: + if (TARGET_VTABLE_USES_DESCRIPTORS + && Ekind (Etype (gnat_node)) == E_Access_Subprogram_Type + && Is_Dispatch_Table_Entity (Etype (gnat_node))) + gnu_result = null_fdesc_node; + else + gnu_result = null_pointer_node; + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case N_Type_Conversion: + case N_Qualified_Expression: + /* Get the operand expression. */ + gnu_result = gnat_to_gnu (Expression (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If this is a qualified expression for a tagged type, we mark the type + as used. Because of polymorphism, this might be the only reference to + the tagged type in the program while objects have it as dynamic type. + The debugger needs to see it to display these objects properly. */ + if (kind == N_Qualified_Expression && Is_Tagged_Type (Etype (gnat_node))) + used_types_insert (gnu_result_type); + + gnu_result + = convert_with_check (Etype (gnat_node), gnu_result, + Do_Overflow_Check (gnat_node), + Do_Range_Check (Expression (gnat_node)), + kind == N_Type_Conversion + && Float_Truncate (gnat_node), gnat_node); + break; + + case N_Unchecked_Type_Conversion: + gnu_result = gnat_to_gnu (Expression (gnat_node)); + + /* Skip further processing if the conversion is deemed a no-op. */ + if (unchecked_conversion_nop (gnat_node)) + { + gnu_result_type = TREE_TYPE (gnu_result); + break; + } + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If the result is a pointer type, see if we are improperly + converting to a stricter alignment. */ + if (STRICT_ALIGNMENT && POINTER_TYPE_P (gnu_result_type) + && IN (Ekind (Etype (gnat_node)), Access_Kind)) + { + unsigned int align = known_alignment (gnu_result); + tree gnu_obj_type = TREE_TYPE (gnu_result_type); + unsigned int oalign = TYPE_ALIGN (gnu_obj_type); + + if (align != 0 && align < oalign && !TYPE_ALIGN_OK (gnu_obj_type)) + post_error_ne_tree_2 + ("?source alignment (^) '< alignment of & (^)", + gnat_node, Designated_Type (Etype (gnat_node)), + size_int (align / BITS_PER_UNIT), oalign / BITS_PER_UNIT); + } + + /* If we are converting a descriptor to a function pointer, first + build the pointer. */ + if (TARGET_VTABLE_USES_DESCRIPTORS + && TREE_TYPE (gnu_result) == fdesc_type_node + && POINTER_TYPE_P (gnu_result_type)) + gnu_result = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_result); + + gnu_result = unchecked_convert (gnu_result_type, gnu_result, + No_Truncation (gnat_node)); + break; + + case N_In: + case N_Not_In: + { + tree gnu_obj = gnat_to_gnu (Left_Opnd (gnat_node)); + Node_Id gnat_range = Right_Opnd (gnat_node); + tree gnu_low, gnu_high; + + /* GNAT_RANGE is either an N_Range node or an identifier denoting a + subtype. */ + if (Nkind (gnat_range) == N_Range) + { + gnu_low = gnat_to_gnu (Low_Bound (gnat_range)); + gnu_high = gnat_to_gnu (High_Bound (gnat_range)); + } + else if (Nkind (gnat_range) == N_Identifier + || Nkind (gnat_range) == N_Expanded_Name) + { + tree gnu_range_type = get_unpadded_type (Entity (gnat_range)); + + gnu_low = TYPE_MIN_VALUE (gnu_range_type); + gnu_high = TYPE_MAX_VALUE (gnu_range_type); + } + else + gcc_unreachable (); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* If LOW and HIGH are identical, perform an equality test. Otherwise, + ensure that GNU_OBJ is evaluated only once and perform a full range + test. */ + if (operand_equal_p (gnu_low, gnu_high, 0)) + gnu_result + = build_binary_op (EQ_EXPR, gnu_result_type, gnu_obj, gnu_low); + else + { + tree t1, t2; + gnu_obj = gnat_protect_expr (gnu_obj); + t1 = build_binary_op (GE_EXPR, gnu_result_type, gnu_obj, gnu_low); + if (EXPR_P (t1)) + set_expr_location_from_node (t1, gnat_node); + t2 = build_binary_op (LE_EXPR, gnu_result_type, gnu_obj, gnu_high); + if (EXPR_P (t2)) + set_expr_location_from_node (t2, gnat_node); + gnu_result + = build_binary_op (TRUTH_ANDIF_EXPR, gnu_result_type, t1, t2); + } + + if (kind == N_Not_In) + gnu_result + = invert_truthvalue_loc (EXPR_LOCATION (gnu_result), gnu_result); + } + break; + + case N_Op_Divide: + gnu_lhs = gnat_to_gnu (Left_Opnd (gnat_node)); + gnu_rhs = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = build_binary_op (FLOAT_TYPE_P (gnu_result_type) + ? RDIV_EXPR + : (Rounded_Result (gnat_node) + ? ROUND_DIV_EXPR : TRUNC_DIV_EXPR), + gnu_result_type, gnu_lhs, gnu_rhs); + break; + + case N_Op_Or: case N_Op_And: case N_Op_Xor: + /* These can either be operations on booleans or on modular types. + Fall through for boolean types since that's the way GNU_CODES is + set up. */ + if (IN (Ekind (Underlying_Type (Etype (gnat_node))), + Modular_Integer_Kind)) + { + enum tree_code code + = (kind == N_Op_Or ? BIT_IOR_EXPR + : kind == N_Op_And ? BIT_AND_EXPR + : BIT_XOR_EXPR); + + gnu_lhs = gnat_to_gnu (Left_Opnd (gnat_node)); + gnu_rhs = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = build_binary_op (code, gnu_result_type, + gnu_lhs, gnu_rhs); + break; + } + + /* ... fall through ... */ + + case N_Op_Eq: case N_Op_Ne: case N_Op_Lt: + case N_Op_Le: case N_Op_Gt: case N_Op_Ge: + case N_Op_Add: case N_Op_Subtract: case N_Op_Multiply: + case N_Op_Mod: case N_Op_Rem: + case N_Op_Rotate_Left: + case N_Op_Rotate_Right: + case N_Op_Shift_Left: + case N_Op_Shift_Right: + case N_Op_Shift_Right_Arithmetic: + case N_And_Then: case N_Or_Else: + { + enum tree_code code = gnu_codes[kind]; + bool ignore_lhs_overflow = false; + location_t saved_location = input_location; + tree gnu_type; + + gnu_lhs = gnat_to_gnu (Left_Opnd (gnat_node)); + gnu_rhs = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_type = gnu_result_type = get_unpadded_type (Etype (gnat_node)); + + /* Pending generic support for efficient vector logical operations in + GCC, convert vectors to their representative array type view and + fallthrough. */ + gnu_lhs = maybe_vector_array (gnu_lhs); + gnu_rhs = maybe_vector_array (gnu_rhs); + + /* If this is a comparison operator, convert any references to + an unconstrained array value into a reference to the + actual array. */ + if (TREE_CODE_CLASS (code) == tcc_comparison) + { + gnu_lhs = maybe_unconstrained_array (gnu_lhs); + gnu_rhs = maybe_unconstrained_array (gnu_rhs); + } + + /* If the result type is a private type, its full view may be a + numeric subtype. The representation we need is that of its base + type, given that it is the result of an arithmetic operation. */ + else if (Is_Private_Type (Etype (gnat_node))) + gnu_type = gnu_result_type + = get_unpadded_type (Base_Type (Full_View (Etype (gnat_node)))); + + /* If this is a shift whose count is not guaranteed to be correct, + we need to adjust the shift count. */ + if (IN (kind, N_Op_Shift) && !Shift_Count_OK (gnat_node)) + { + tree gnu_count_type = get_base_type (TREE_TYPE (gnu_rhs)); + tree gnu_max_shift + = convert (gnu_count_type, TYPE_SIZE (gnu_type)); + + if (kind == N_Op_Rotate_Left || kind == N_Op_Rotate_Right) + gnu_rhs = build_binary_op (TRUNC_MOD_EXPR, gnu_count_type, + gnu_rhs, gnu_max_shift); + else if (kind == N_Op_Shift_Right_Arithmetic) + gnu_rhs + = build_binary_op + (MIN_EXPR, gnu_count_type, + build_binary_op (MINUS_EXPR, + gnu_count_type, + gnu_max_shift, + convert (gnu_count_type, + integer_one_node)), + gnu_rhs); + } + + /* For right shifts, the type says what kind of shift to do, + so we may need to choose a different type. In this case, + we have to ignore integer overflow lest it propagates all + the way down and causes a CE to be explicitly raised. */ + if (kind == N_Op_Shift_Right && !TYPE_UNSIGNED (gnu_type)) + { + gnu_type = gnat_unsigned_type (gnu_type); + ignore_lhs_overflow = true; + } + else if (kind == N_Op_Shift_Right_Arithmetic + && TYPE_UNSIGNED (gnu_type)) + { + gnu_type = gnat_signed_type (gnu_type); + ignore_lhs_overflow = true; + } + + if (gnu_type != gnu_result_type) + { + tree gnu_old_lhs = gnu_lhs; + gnu_lhs = convert (gnu_type, gnu_lhs); + if (TREE_CODE (gnu_lhs) == INTEGER_CST && ignore_lhs_overflow) + TREE_OVERFLOW (gnu_lhs) = TREE_OVERFLOW (gnu_old_lhs); + gnu_rhs = convert (gnu_type, gnu_rhs); + } + + /* Instead of expanding overflow checks for addition, subtraction + and multiplication itself, the front end will leave this to + the back end when Backend_Overflow_Checks_On_Target is set. + As the GCC back end itself does not know yet how to properly + do overflow checking, do it here. The goal is to push + the expansions further into the back end over time. */ + if (Do_Overflow_Check (gnat_node) && Backend_Overflow_Checks_On_Target + && (kind == N_Op_Add + || kind == N_Op_Subtract + || kind == N_Op_Multiply) + && !TYPE_UNSIGNED (gnu_type) + && !FLOAT_TYPE_P (gnu_type)) + gnu_result = build_binary_op_trapv (code, gnu_type, + gnu_lhs, gnu_rhs, gnat_node); + else + { + /* Some operations, e.g. comparisons of arrays, generate complex + trees that need to be annotated while they are being built. */ + input_location = saved_location; + gnu_result = build_binary_op (code, gnu_type, gnu_lhs, gnu_rhs); + } + + /* If this is a logical shift with the shift count not verified, + we must return zero if it is too large. We cannot compensate + above in this case. */ + if ((kind == N_Op_Shift_Left || kind == N_Op_Shift_Right) + && !Shift_Count_OK (gnat_node)) + gnu_result + = build_cond_expr + (gnu_type, + build_binary_op (GE_EXPR, boolean_type_node, + gnu_rhs, + convert (TREE_TYPE (gnu_rhs), + TYPE_SIZE (gnu_type))), + convert (gnu_type, integer_zero_node), + gnu_result); + } + break; + + case N_If_Expression: + { + tree gnu_cond = gnat_to_gnu (First (Expressions (gnat_node))); + tree gnu_true = gnat_to_gnu (Next (First (Expressions (gnat_node)))); + tree gnu_false + = gnat_to_gnu (Next (Next (First (Expressions (gnat_node))))); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result + = build_cond_expr (gnu_result_type, gnu_cond, gnu_true, gnu_false); + } + break; + + case N_Op_Plus: + gnu_result = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case N_Op_Not: + /* This case can apply to a boolean or a modular type. + Fall through for a boolean operand since GNU_CODES is set + up to handle this. */ + if (Is_Modular_Integer_Type (Etype (gnat_node)) + || (Ekind (Etype (gnat_node)) == E_Private_Type + && Is_Modular_Integer_Type (Full_View (Etype (gnat_node))))) + { + gnu_expr = gnat_to_gnu (Right_Opnd (gnat_node)); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + gnu_result = build_unary_op (BIT_NOT_EXPR, gnu_result_type, + gnu_expr); + break; + } + + /* ... fall through ... */ + + case N_Op_Minus: case N_Op_Abs: + gnu_expr = gnat_to_gnu (Right_Opnd (gnat_node)); + + if (Ekind (Etype (gnat_node)) != E_Private_Type) + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + else + gnu_result_type = get_unpadded_type (Base_Type + (Full_View (Etype (gnat_node)))); + + if (Do_Overflow_Check (gnat_node) + && !TYPE_UNSIGNED (gnu_result_type) + && !FLOAT_TYPE_P (gnu_result_type)) + gnu_result + = build_unary_op_trapv (gnu_codes[kind], + gnu_result_type, gnu_expr, gnat_node); + else + gnu_result = build_unary_op (gnu_codes[kind], + gnu_result_type, gnu_expr); + break; + + case N_Allocator: + { + tree gnu_init = 0; + tree gnu_type; + bool ignore_init_type = false; + + gnat_temp = Expression (gnat_node); + + /* The Expression operand can either be an N_Identifier or + Expanded_Name, which must represent a type, or a + N_Qualified_Expression, which contains both the object type and an + initial value for the object. */ + if (Nkind (gnat_temp) == N_Identifier + || Nkind (gnat_temp) == N_Expanded_Name) + gnu_type = gnat_to_gnu_type (Entity (gnat_temp)); + else if (Nkind (gnat_temp) == N_Qualified_Expression) + { + Entity_Id gnat_desig_type + = Designated_Type (Underlying_Type (Etype (gnat_node))); + + ignore_init_type = Has_Constrained_Partial_View (gnat_desig_type); + gnu_init = gnat_to_gnu (Expression (gnat_temp)); + + gnu_init = maybe_unconstrained_array (gnu_init); + if (Do_Range_Check (Expression (gnat_temp))) + gnu_init + = emit_range_check (gnu_init, gnat_desig_type, gnat_temp); + + if (Is_Elementary_Type (gnat_desig_type) + || Is_Constrained (gnat_desig_type)) + gnu_type = gnat_to_gnu_type (gnat_desig_type); + else + { + gnu_type = gnat_to_gnu_type (Etype (Expression (gnat_temp))); + if (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_type = TREE_TYPE (gnu_init); + } + + /* See the N_Qualified_Expression case for the rationale. */ + if (Is_Tagged_Type (gnat_desig_type)) + used_types_insert (gnu_type); + + gnu_init = convert (gnu_type, gnu_init); + } + else + gcc_unreachable (); + + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + return build_allocator (gnu_type, gnu_init, gnu_result_type, + Procedure_To_Call (gnat_node), + Storage_Pool (gnat_node), gnat_node, + ignore_init_type); + } + break; + + /**************************/ + /* Chapter 5: Statements */ + /**************************/ + + case N_Label: + gnu_result = build1 (LABEL_EXPR, void_type_node, + gnat_to_gnu (Identifier (gnat_node))); + break; + + case N_Null_Statement: + /* When not optimizing, turn null statements from source into gotos to + the next statement that the middle-end knows how to preserve. */ + if (!optimize && Comes_From_Source (gnat_node)) + { + tree stmt, label = create_label_decl (NULL_TREE, gnat_node); + DECL_IGNORED_P (label) = 1; + start_stmt_group (); + stmt = build1 (GOTO_EXPR, void_type_node, label); + set_expr_location_from_node (stmt, gnat_node); + add_stmt (stmt); + stmt = build1 (LABEL_EXPR, void_type_node, label); + set_expr_location_from_node (stmt, gnat_node); + add_stmt (stmt); + gnu_result = end_stmt_group (); + } + else + gnu_result = alloc_stmt_list (); + break; + + case N_Assignment_Statement: + /* Get the LHS and RHS of the statement and convert any reference to an + unconstrained array into a reference to the underlying array. */ + gnu_lhs = maybe_unconstrained_array (gnat_to_gnu (Name (gnat_node))); + + /* If the type has a size that overflows, convert this into raise of + Storage_Error: execution shouldn't have gotten here anyway. */ + if (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (gnu_lhs))) == INTEGER_CST + && !valid_constant_size_p (TYPE_SIZE_UNIT (TREE_TYPE (gnu_lhs)))) + gnu_result = build_call_raise (SE_Object_Too_Large, gnat_node, + N_Raise_Storage_Error); + else if (Nkind (Expression (gnat_node)) == N_Function_Call) + gnu_result + = Call_to_gnu (Expression (gnat_node), &gnu_result_type, gnu_lhs, + atomic_sync_required_p (Name (gnat_node))); + else + { + gnu_rhs + = maybe_unconstrained_array (gnat_to_gnu (Expression (gnat_node))); + + /* If range check is needed, emit code to generate it. */ + if (Do_Range_Check (Expression (gnat_node))) + gnu_rhs = emit_range_check (gnu_rhs, Etype (Name (gnat_node)), + gnat_node); + + if (atomic_sync_required_p (Name (gnat_node))) + gnu_result = build_atomic_store (gnu_lhs, gnu_rhs); + else + gnu_result + = build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_lhs, gnu_rhs); + + /* If the type being assigned is an array type and the two sides are + not completely disjoint, play safe and use memmove. But don't do + it for a bit-packed array as it might not be byte-aligned. */ + if (TREE_CODE (gnu_result) == MODIFY_EXPR + && Is_Array_Type (Etype (Name (gnat_node))) + && !Is_Bit_Packed_Array (Etype (Name (gnat_node))) + && !(Forwards_OK (gnat_node) && Backwards_OK (gnat_node))) + { + tree to, from, size, to_ptr, from_ptr, t; + + to = TREE_OPERAND (gnu_result, 0); + from = TREE_OPERAND (gnu_result, 1); + + size = TYPE_SIZE_UNIT (TREE_TYPE (from)); + size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, from); + + to_ptr = build_fold_addr_expr (to); + from_ptr = build_fold_addr_expr (from); + + t = builtin_decl_implicit (BUILT_IN_MEMMOVE); + gnu_result = build_call_expr (t, 3, to_ptr, from_ptr, size); + } + } + break; + + case N_If_Statement: + { + tree *gnu_else_ptr; /* Point to put next "else if" or "else". */ + + /* Make the outer COND_EXPR. Avoid non-determinism. */ + gnu_result = build3 (COND_EXPR, void_type_node, + gnat_to_gnu (Condition (gnat_node)), + NULL_TREE, NULL_TREE); + COND_EXPR_THEN (gnu_result) + = build_stmt_group (Then_Statements (gnat_node), false); + TREE_SIDE_EFFECTS (gnu_result) = 1; + gnu_else_ptr = &COND_EXPR_ELSE (gnu_result); + + /* Now make a COND_EXPR for each of the "else if" parts. Put each + into the previous "else" part and point to where to put any + outer "else". Also avoid non-determinism. */ + if (Present (Elsif_Parts (gnat_node))) + for (gnat_temp = First (Elsif_Parts (gnat_node)); + Present (gnat_temp); gnat_temp = Next (gnat_temp)) + { + gnu_expr = build3 (COND_EXPR, void_type_node, + gnat_to_gnu (Condition (gnat_temp)), + NULL_TREE, NULL_TREE); + COND_EXPR_THEN (gnu_expr) + = build_stmt_group (Then_Statements (gnat_temp), false); + TREE_SIDE_EFFECTS (gnu_expr) = 1; + set_expr_location_from_node (gnu_expr, gnat_temp); + *gnu_else_ptr = gnu_expr; + gnu_else_ptr = &COND_EXPR_ELSE (gnu_expr); + } + + *gnu_else_ptr = build_stmt_group (Else_Statements (gnat_node), false); + } + break; + + case N_Case_Statement: + gnu_result = Case_Statement_to_gnu (gnat_node); + break; + + case N_Loop_Statement: + gnu_result = Loop_Statement_to_gnu (gnat_node); + break; + + case N_Block_Statement: + /* The only way to enter the block is to fall through to it. */ + if (stmt_group_may_fallthru ()) + { + start_stmt_group (); + gnat_pushlevel (); + process_decls (Declarations (gnat_node), Empty, Empty, true, true); + add_stmt (gnat_to_gnu (Handled_Statement_Sequence (gnat_node))); + gnat_poplevel (); + gnu_result = end_stmt_group (); + } + else + gnu_result = alloc_stmt_list (); + break; + + case N_Exit_Statement: + gnu_result + = build2 (EXIT_STMT, void_type_node, + (Present (Condition (gnat_node)) + ? gnat_to_gnu (Condition (gnat_node)) : NULL_TREE), + (Present (Name (gnat_node)) + ? get_gnu_tree (Entity (Name (gnat_node))) + : gnu_loop_stack->last ()->label)); + break; + + case N_Simple_Return_Statement: + { + tree gnu_ret_obj, gnu_ret_val; + + /* If the subprogram is a function, we must return the expression. */ + if (Present (Expression (gnat_node))) + { + tree gnu_subprog_type = TREE_TYPE (current_function_decl); + + /* If this function has copy-in/copy-out parameters, get the real + object for the return. See Subprogram_to_gnu. */ + if (TYPE_CI_CO_LIST (gnu_subprog_type)) + gnu_ret_obj = gnu_return_var_stack->last (); + else + gnu_ret_obj = DECL_RESULT (current_function_decl); + + /* Get the GCC tree for the expression to be returned. */ + gnu_ret_val = gnat_to_gnu (Expression (gnat_node)); + + /* Do not remove the padding from GNU_RET_VAL if the inner type is + self-referential since we want to allocate the fixed size. */ + if (TREE_CODE (gnu_ret_val) == COMPONENT_REF + && TYPE_IS_PADDING_P + (TREE_TYPE (TREE_OPERAND (gnu_ret_val, 0))) + && CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (gnu_ret_val)))) + gnu_ret_val = TREE_OPERAND (gnu_ret_val, 0); + + /* If the function returns by direct reference, return a pointer + to the return value. */ + if (TYPE_RETURN_BY_DIRECT_REF_P (gnu_subprog_type) + || By_Ref (gnat_node)) + gnu_ret_val = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_ret_val); + + /* Otherwise, if it returns an unconstrained array, we have to + allocate a new version of the result and return it. */ + else if (TYPE_RETURN_UNCONSTRAINED_P (gnu_subprog_type)) + { + gnu_ret_val = maybe_unconstrained_array (gnu_ret_val); + + /* And find out whether this is a candidate for Named Return + Value. If so, record it. */ + if (!TYPE_CI_CO_LIST (gnu_subprog_type) && optimize) + { + tree ret_val = gnu_ret_val; + + /* Strip useless conversions around the return value. */ + if (gnat_useless_type_conversion (ret_val)) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Strip unpadding around the return value. */ + if (TREE_CODE (ret_val) == COMPONENT_REF + && TYPE_IS_PADDING_P + (TREE_TYPE (TREE_OPERAND (ret_val, 0)))) + ret_val = TREE_OPERAND (ret_val, 0); + + /* Now apply the test to the return value. */ + if (return_value_ok_for_nrv_p (NULL_TREE, ret_val)) + { + if (!f_named_ret_val) + f_named_ret_val = BITMAP_GGC_ALLOC (); + bitmap_set_bit (f_named_ret_val, DECL_UID (ret_val)); + if (!f_gnat_ret) + f_gnat_ret = gnat_node; + } + } + + gnu_ret_val = build_allocator (TREE_TYPE (gnu_ret_val), + gnu_ret_val, + TREE_TYPE (gnu_ret_obj), + Procedure_To_Call (gnat_node), + Storage_Pool (gnat_node), + gnat_node, false); + } + + /* Otherwise, if it returns by invisible reference, dereference + the pointer it is passed using the type of the return value + and build the copy operation manually. This ensures that we + don't copy too much data, for example if the return type is + unconstrained with a maximum size. */ + else if (TREE_ADDRESSABLE (gnu_subprog_type)) + { + tree gnu_ret_deref + = build_unary_op (INDIRECT_REF, TREE_TYPE (gnu_ret_val), + gnu_ret_obj); + gnu_result = build_binary_op (MODIFY_EXPR, NULL_TREE, + gnu_ret_deref, gnu_ret_val); + add_stmt_with_node (gnu_result, gnat_node); + gnu_ret_val = NULL_TREE; + } + } + + else + gnu_ret_obj = gnu_ret_val = NULL_TREE; + + /* If we have a return label defined, convert this into a branch to + that label. The return proper will be handled elsewhere. */ + if (gnu_return_label_stack->last ()) + { + if (gnu_ret_obj) + add_stmt (build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_ret_obj, + gnu_ret_val)); + + gnu_result = build1 (GOTO_EXPR, void_type_node, + gnu_return_label_stack->last ()); + + /* When not optimizing, make sure the return is preserved. */ + if (!optimize && Comes_From_Source (gnat_node)) + DECL_ARTIFICIAL (gnu_return_label_stack->last ()) = 0; + } + + /* Otherwise, build a regular return. */ + else + gnu_result = build_return_expr (gnu_ret_obj, gnu_ret_val); + } + break; + + case N_Goto_Statement: + gnu_result + = build1 (GOTO_EXPR, void_type_node, gnat_to_gnu (Name (gnat_node))); + break; + + /***************************/ + /* Chapter 6: Subprograms */ + /***************************/ + + case N_Subprogram_Declaration: + /* Unless there is a freeze node, declare the subprogram. We consider + this a "definition" even though we're not generating code for + the subprogram because we will be making the corresponding GCC + node here. */ + + if (No (Freeze_Node (Defining_Entity (Specification (gnat_node))))) + gnat_to_gnu_entity (Defining_Entity (Specification (gnat_node)), + NULL_TREE, 1); + gnu_result = alloc_stmt_list (); + break; + + case N_Abstract_Subprogram_Declaration: + /* This subprogram doesn't exist for code generation purposes, but we + have to elaborate the types of any parameters and result, unless + they are imported types (nothing to generate in this case). + + The parameter list may contain types with freeze nodes, e.g. not null + subtypes, so the subprogram itself may carry a freeze node, in which + case its elaboration must be deferred. */ + + /* Process the parameter types first. */ + if (No (Freeze_Node (Defining_Entity (Specification (gnat_node))))) + for (gnat_temp + = First_Formal_With_Extras + (Defining_Entity (Specification (gnat_node))); + Present (gnat_temp); + gnat_temp = Next_Formal_With_Extras (gnat_temp)) + if (Is_Itype (Etype (gnat_temp)) + && !From_With_Type (Etype (gnat_temp))) + gnat_to_gnu_entity (Etype (gnat_temp), NULL_TREE, 0); + + /* Then the result type, set to Standard_Void_Type for procedures. */ + { + Entity_Id gnat_temp_type + = Etype (Defining_Entity (Specification (gnat_node))); + + if (Is_Itype (gnat_temp_type) && !From_With_Type (gnat_temp_type)) + gnat_to_gnu_entity (Etype (gnat_temp_type), NULL_TREE, 0); + } + + gnu_result = alloc_stmt_list (); + break; + + case N_Defining_Program_Unit_Name: + /* For a child unit identifier go up a level to get the specification. + We get this when we try to find the spec of a child unit package + that is the compilation unit being compiled. */ + gnu_result = gnat_to_gnu (Parent (gnat_node)); + break; + + case N_Subprogram_Body: + Subprogram_Body_to_gnu (gnat_node); + gnu_result = alloc_stmt_list (); + break; + + case N_Function_Call: + case N_Procedure_Call_Statement: + gnu_result = Call_to_gnu (gnat_node, &gnu_result_type, NULL_TREE, false); + break; + + /************************/ + /* Chapter 7: Packages */ + /************************/ + + case N_Package_Declaration: + gnu_result = gnat_to_gnu (Specification (gnat_node)); + break; + + case N_Package_Specification: + + start_stmt_group (); + process_decls (Visible_Declarations (gnat_node), + Private_Declarations (gnat_node), Empty, true, true); + gnu_result = end_stmt_group (); + break; + + case N_Package_Body: + + /* If this is the body of a generic package - do nothing. */ + if (Ekind (Corresponding_Spec (gnat_node)) == E_Generic_Package) + { + gnu_result = alloc_stmt_list (); + break; + } + + start_stmt_group (); + process_decls (Declarations (gnat_node), Empty, Empty, true, true); + + if (Present (Handled_Statement_Sequence (gnat_node))) + add_stmt (gnat_to_gnu (Handled_Statement_Sequence (gnat_node))); + + gnu_result = end_stmt_group (); + break; + + /********************************/ + /* Chapter 8: Visibility Rules */ + /********************************/ + + case N_Use_Package_Clause: + case N_Use_Type_Clause: + /* Nothing to do here - but these may appear in list of declarations. */ + gnu_result = alloc_stmt_list (); + break; + + /*********************/ + /* Chapter 9: Tasks */ + /*********************/ + + case N_Protected_Type_Declaration: + gnu_result = alloc_stmt_list (); + break; + + case N_Single_Task_Declaration: + gnat_to_gnu_entity (Defining_Entity (gnat_node), NULL_TREE, 1); + gnu_result = alloc_stmt_list (); + break; + + /*********************************************************/ + /* Chapter 10: Program Structure and Compilation Issues */ + /*********************************************************/ + + case N_Compilation_Unit: + /* This is not called for the main unit on which gigi is invoked. */ + Compilation_Unit_to_gnu (gnat_node); + gnu_result = alloc_stmt_list (); + break; + + case N_Subprogram_Body_Stub: + case N_Package_Body_Stub: + case N_Protected_Body_Stub: + case N_Task_Body_Stub: + /* Simply process whatever unit is being inserted. */ + if (Present (Library_Unit (gnat_node))) + gnu_result = gnat_to_gnu (Unit (Library_Unit (gnat_node))); + else + { + gcc_assert (type_annotate_only); + gnu_result = alloc_stmt_list (); + } + break; + + case N_Subunit: + gnu_result = gnat_to_gnu (Proper_Body (gnat_node)); + break; + + /***************************/ + /* Chapter 11: Exceptions */ + /***************************/ + + case N_Handled_Sequence_Of_Statements: + /* If there is an At_End procedure attached to this node, and the EH + mechanism is SJLJ, we must have at least a corresponding At_End + handler, unless the No_Exception_Handlers restriction is set. */ + gcc_assert (type_annotate_only + || Exception_Mechanism != Setjmp_Longjmp + || No (At_End_Proc (gnat_node)) + || Present (Exception_Handlers (gnat_node)) + || No_Exception_Handlers_Set ()); + + gnu_result = Handled_Sequence_Of_Statements_to_gnu (gnat_node); + break; + + case N_Exception_Handler: + if (Exception_Mechanism == Setjmp_Longjmp) + gnu_result = Exception_Handler_to_gnu_sjlj (gnat_node); + else if (Exception_Mechanism == Back_End_Exceptions) + gnu_result = Exception_Handler_to_gnu_zcx (gnat_node); + else + gcc_unreachable (); + break; + + case N_Raise_Statement: + /* Only for reraise in back-end exceptions mode. */ + gcc_assert (No (Name (gnat_node)) + && Exception_Mechanism == Back_End_Exceptions); + + start_stmt_group (); + gnat_pushlevel (); + + /* Clear the current exception pointer so that the occurrence won't be + deallocated. */ + gnu_expr = create_var_decl (get_identifier ("SAVED_EXPTR"), NULL_TREE, + ptr_type_node, gnu_incoming_exc_ptr, + false, false, false, false, NULL, gnat_node); + + add_stmt (build_binary_op (MODIFY_EXPR, NULL_TREE, gnu_incoming_exc_ptr, + convert (ptr_type_node, integer_zero_node))); + add_stmt (build_call_n_expr (reraise_zcx_decl, 1, gnu_expr)); + gnat_poplevel (); + gnu_result = end_stmt_group (); + break; + + case N_Push_Constraint_Error_Label: + push_exception_label_stack (&gnu_constraint_error_label_stack, + Exception_Label (gnat_node)); + break; + + case N_Push_Storage_Error_Label: + push_exception_label_stack (&gnu_storage_error_label_stack, + Exception_Label (gnat_node)); + break; + + case N_Push_Program_Error_Label: + push_exception_label_stack (&gnu_program_error_label_stack, + Exception_Label (gnat_node)); + break; + + case N_Pop_Constraint_Error_Label: + gnu_constraint_error_label_stack->pop (); + break; + + case N_Pop_Storage_Error_Label: + gnu_storage_error_label_stack->pop (); + break; + + case N_Pop_Program_Error_Label: + gnu_program_error_label_stack->pop (); + break; + + /******************************/ + /* Chapter 12: Generic Units */ + /******************************/ + + case N_Generic_Function_Renaming_Declaration: + case N_Generic_Package_Renaming_Declaration: + case N_Generic_Procedure_Renaming_Declaration: + case N_Generic_Package_Declaration: + case N_Generic_Subprogram_Declaration: + case N_Package_Instantiation: + case N_Procedure_Instantiation: + case N_Function_Instantiation: + /* These nodes can appear on a declaration list but there is nothing to + to be done with them. */ + gnu_result = alloc_stmt_list (); + break; + + /**************************************************/ + /* Chapter 13: Representation Clauses and */ + /* Implementation-Dependent Features */ + /**************************************************/ + + case N_Attribute_Definition_Clause: + gnu_result = alloc_stmt_list (); + + /* The only one we need to deal with is 'Address since, for the others, + the front-end puts the information elsewhere. */ + if (Get_Attribute_Id (Chars (gnat_node)) != Attr_Address) + break; + + /* And we only deal with 'Address if the object has a Freeze node. */ + gnat_temp = Entity (Name (gnat_node)); + if (No (Freeze_Node (gnat_temp))) + break; + + /* Get the value to use as the address and save it as the equivalent + for the object. When it is frozen, gnat_to_gnu_entity will do the + right thing. */ + save_gnu_tree (gnat_temp, gnat_to_gnu (Expression (gnat_node)), true); + break; + + case N_Enumeration_Representation_Clause: + case N_Record_Representation_Clause: + case N_At_Clause: + /* We do nothing with these. SEM puts the information elsewhere. */ + gnu_result = alloc_stmt_list (); + break; + + case N_Code_Statement: + if (!type_annotate_only) + { + tree gnu_template = gnat_to_gnu (Asm_Template (gnat_node)); + tree gnu_inputs = NULL_TREE, gnu_outputs = NULL_TREE; + tree gnu_clobbers = NULL_TREE, tail; + bool allows_mem, allows_reg, fake; + int ninputs, noutputs, i; + const char **oconstraints; + const char *constraint; + char *clobber; + + /* First retrieve the 3 operand lists built by the front-end. */ + Setup_Asm_Outputs (gnat_node); + while (Present (gnat_temp = Asm_Output_Variable ())) + { + tree gnu_value = gnat_to_gnu (gnat_temp); + tree gnu_constr = build_tree_list (NULL_TREE, gnat_to_gnu + (Asm_Output_Constraint ())); + + gnu_outputs = tree_cons (gnu_constr, gnu_value, gnu_outputs); + Next_Asm_Output (); + } + + Setup_Asm_Inputs (gnat_node); + while (Present (gnat_temp = Asm_Input_Value ())) + { + tree gnu_value = gnat_to_gnu (gnat_temp); + tree gnu_constr = build_tree_list (NULL_TREE, gnat_to_gnu + (Asm_Input_Constraint ())); + + gnu_inputs = tree_cons (gnu_constr, gnu_value, gnu_inputs); + Next_Asm_Input (); + } + + Clobber_Setup (gnat_node); + while ((clobber = Clobber_Get_Next ())) + gnu_clobbers + = tree_cons (NULL_TREE, + build_string (strlen (clobber) + 1, clobber), + gnu_clobbers); + + /* Then perform some standard checking and processing on the + operands. In particular, mark them addressable if needed. */ + gnu_outputs = nreverse (gnu_outputs); + noutputs = list_length (gnu_outputs); + gnu_inputs = nreverse (gnu_inputs); + ninputs = list_length (gnu_inputs); + oconstraints = XALLOCAVEC (const char *, noutputs); + + for (i = 0, tail = gnu_outputs; tail; ++i, tail = TREE_CHAIN (tail)) + { + tree output = TREE_VALUE (tail); + constraint + = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); + oconstraints[i] = constraint; + + if (parse_output_constraint (&constraint, i, ninputs, noutputs, + &allows_mem, &allows_reg, &fake)) + { + /* If the operand is going to end up in memory, + mark it addressable. Note that we don't test + allows_mem like in the input case below; this + is modelled on the C front-end. */ + if (!allows_reg) + { + output = remove_conversions (output, false); + if (TREE_CODE (output) == CONST_DECL + && DECL_CONST_CORRESPONDING_VAR (output)) + output = DECL_CONST_CORRESPONDING_VAR (output); + if (!gnat_mark_addressable (output)) + output = error_mark_node; + } + } + else + output = error_mark_node; + + TREE_VALUE (tail) = output; + } + + for (i = 0, tail = gnu_inputs; tail; ++i, tail = TREE_CHAIN (tail)) + { + tree input = TREE_VALUE (tail); + constraint + = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); + + if (parse_input_constraint (&constraint, i, ninputs, noutputs, + 0, oconstraints, + &allows_mem, &allows_reg)) + { + /* If the operand is going to end up in memory, + mark it addressable. */ + if (!allows_reg && allows_mem) + { + input = remove_conversions (input, false); + if (TREE_CODE (input) == CONST_DECL + && DECL_CONST_CORRESPONDING_VAR (input)) + input = DECL_CONST_CORRESPONDING_VAR (input); + if (!gnat_mark_addressable (input)) + input = error_mark_node; + } + } + else + input = error_mark_node; + + TREE_VALUE (tail) = input; + } + + gnu_result = build5 (ASM_EXPR, void_type_node, + gnu_template, gnu_outputs, + gnu_inputs, gnu_clobbers, NULL_TREE); + ASM_VOLATILE_P (gnu_result) = Is_Asm_Volatile (gnat_node); + } + else + gnu_result = alloc_stmt_list (); + + break; + + /****************/ + /* Added Nodes */ + /****************/ + + case N_Expression_With_Actions: + /* This construct doesn't define a scope so we don't wrap the statement + list in a BIND_EXPR; however, we wrap it in a SAVE_EXPR to protect it + from unsharing. */ + gnu_result = build_stmt_group (Actions (gnat_node), false); + gnu_result = build1 (SAVE_EXPR, void_type_node, gnu_result); + TREE_SIDE_EFFECTS (gnu_result) = 1; + gnu_expr = gnat_to_gnu (Expression (gnat_node)); + gnu_result + = build_compound_expr (TREE_TYPE (gnu_expr), gnu_result, gnu_expr); + gnu_result_type = get_unpadded_type (Etype (gnat_node)); + break; + + case N_Freeze_Entity: + start_stmt_group (); + process_freeze_entity (gnat_node); + process_decls (Actions (gnat_node), Empty, Empty, true, true); + gnu_result = end_stmt_group (); + break; + + case N_Itype_Reference: + if (!present_gnu_tree (Itype (gnat_node))) + process_type (Itype (gnat_node)); + + gnu_result = alloc_stmt_list (); + break; + + case N_Free_Statement: + if (!type_annotate_only) + { + tree gnu_ptr = gnat_to_gnu (Expression (gnat_node)); + tree gnu_ptr_type = TREE_TYPE (gnu_ptr); + tree gnu_obj_type, gnu_actual_obj_type; + + /* If this is a thin pointer, we must first dereference it to create + a fat pointer, then go back below to a thin pointer. The reason + for this is that we need to have a fat pointer someplace in order + to properly compute the size. */ + if (TYPE_IS_THIN_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr = build_unary_op (ADDR_EXPR, NULL_TREE, + build_unary_op (INDIRECT_REF, NULL_TREE, + gnu_ptr)); + + /* If this is a fat pointer, the object must have been allocated with + the template in front of the array. So pass the template address, + and get the total size; do it by converting to a thin pointer. */ + if (TYPE_IS_FAT_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr + = convert (build_pointer_type + (TYPE_OBJECT_RECORD_TYPE + (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (gnu_ptr)))), + gnu_ptr); + + gnu_obj_type = TREE_TYPE (TREE_TYPE (gnu_ptr)); + + /* If this is a thin pointer, the object must have been allocated with + the template in front of the array. So pass the template address, + and get the total size. */ + if (TYPE_IS_THIN_POINTER_P (TREE_TYPE (gnu_ptr))) + gnu_ptr + = build_binary_op (POINTER_PLUS_EXPR, TREE_TYPE (gnu_ptr), + gnu_ptr, + fold_build1 (NEGATE_EXPR, sizetype, + byte_position + (DECL_CHAIN + TYPE_FIELDS ((gnu_obj_type))))); + + /* If we have a special dynamic constrained subtype on the node, use + it to compute the size; otherwise, use the designated subtype. */ + if (Present (Actual_Designated_Subtype (gnat_node))) + { + gnu_actual_obj_type + = gnat_to_gnu_type (Actual_Designated_Subtype (gnat_node)); + + if (TYPE_IS_FAT_OR_THIN_POINTER_P (gnu_ptr_type)) + gnu_actual_obj_type + = build_unc_object_type_from_ptr (gnu_ptr_type, + gnu_actual_obj_type, + get_identifier ("DEALLOC"), + false); + } + else + gnu_actual_obj_type = gnu_obj_type; + + gnu_result + = build_call_alloc_dealloc (gnu_ptr, + TYPE_SIZE_UNIT (gnu_actual_obj_type), + gnu_obj_type, + Procedure_To_Call (gnat_node), + Storage_Pool (gnat_node), + gnat_node); + } + break; + + case N_Raise_Constraint_Error: + case N_Raise_Program_Error: + case N_Raise_Storage_Error: + if (type_annotate_only) + gnu_result = alloc_stmt_list (); + else + gnu_result = Raise_Error_to_gnu (gnat_node, &gnu_result_type); + break; + + case N_Validate_Unchecked_Conversion: + /* The only validation we currently do on an unchecked conversion is + that of aliasing assumptions. */ + if (flag_strict_aliasing) + gnat_validate_uc_list.safe_push (gnat_node); + gnu_result = alloc_stmt_list (); + break; + + case N_Function_Specification: + case N_Procedure_Specification: + case N_Op_Concat: + case N_Component_Association: + case N_Protected_Body: + case N_Task_Body: + /* These nodes should only be present when annotating types. */ + gcc_assert (type_annotate_only); + gnu_result = alloc_stmt_list (); + break; + + default: + /* Other nodes are not supposed to reach here. */ + gcc_unreachable (); + } + + /* If we pushed the processing of the elaboration routine, pop it back. */ + if (went_into_elab_proc) + current_function_decl = NULL_TREE; + + /* When not optimizing, turn boolean rvalues B into B != false tests + so that the code just below can put the location information of the + reference to B on the inequality operator for better debug info. */ + if (!optimize + && TREE_CODE (gnu_result) != INTEGER_CST + && (kind == N_Identifier + || kind == N_Expanded_Name + || kind == N_Explicit_Dereference + || kind == N_Function_Call + || kind == N_Indexed_Component + || kind == N_Selected_Component) + && TREE_CODE (get_base_type (gnu_result_type)) == BOOLEAN_TYPE + && !lvalue_required_p (gnat_node, gnu_result_type, false, false, false)) + gnu_result = build_binary_op (NE_EXPR, gnu_result_type, + convert (gnu_result_type, gnu_result), + convert (gnu_result_type, + boolean_false_node)); + + /* Set the location information on the result. Note that we may have + no result if we tried to build a CALL_EXPR node to a procedure with + no side-effects and optimization is enabled. */ + if (gnu_result && EXPR_P (gnu_result)) + set_gnu_expr_location_from_node (gnu_result, gnat_node); + + /* If we're supposed to return something of void_type, it means we have + something we're elaborating for effect, so just return. */ + if (TREE_CODE (gnu_result_type) == VOID_TYPE) + return gnu_result; + + /* If the result is a constant that overflowed, raise Constraint_Error. */ + if (TREE_CODE (gnu_result) == INTEGER_CST && TREE_OVERFLOW (gnu_result)) + { + post_error ("?`Constraint_Error` will be raised at run time", gnat_node); + gnu_result + = build1 (NULL_EXPR, gnu_result_type, + build_call_raise (CE_Overflow_Check_Failed, gnat_node, + N_Raise_Constraint_Error)); + } + + /* If the result has side-effects and is of an unconstrained type, make a + SAVE_EXPR so that we can be sure it will only be referenced once. But + this is useless for a call to a function that returns an unconstrained + type with default discriminant, as we cannot compute the size of the + actual returned object. We must do this before any conversions. */ + if (TREE_SIDE_EFFECTS (gnu_result) + && !(TREE_CODE (gnu_result) == CALL_EXPR + && TYPE_IS_PADDING_P (TREE_TYPE (gnu_result))) + && (TREE_CODE (gnu_result_type) == UNCONSTRAINED_ARRAY_TYPE + || CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_result_type)))) + gnu_result = gnat_stabilize_reference (gnu_result, false, NULL); + + /* Now convert the result to the result type, unless we are in one of the + following cases: + + 1. If this is the LHS of an assignment or an actual parameter of a + call, return the result almost unmodified since the RHS will have + to be converted to our type in that case, unless the result type + has a simpler size. Likewise if there is just a no-op unchecked + conversion in-between. Similarly, don't convert integral types + that are the operands of an unchecked conversion since we need + to ignore those conversions (for 'Valid). + + 2. If we have a label (which doesn't have any well-defined type), a + field or an error, return the result almost unmodified. Similarly, + if the two types are record types with the same name, don't convert. + This will be the case when we are converting from a packable version + of a type to its original type and we need those conversions to be + NOPs in order for assignments into these types to work properly. + + 3. If the type is void or if we have no result, return error_mark_node + to show we have no result. + + 4. If this a call to a function that returns an unconstrained type with + default discriminant, return the call expression unmodified since we + cannot compute the size of the actual returned object. + + 5. Finally, if the type of the result is already correct. */ + + if (Present (Parent (gnat_node)) + && (lhs_or_actual_p (gnat_node) + || (Nkind (Parent (gnat_node)) == N_Unchecked_Type_Conversion + && unchecked_conversion_nop (Parent (gnat_node))) + || (Nkind (Parent (gnat_node)) == N_Unchecked_Type_Conversion + && !AGGREGATE_TYPE_P (gnu_result_type) + && !AGGREGATE_TYPE_P (TREE_TYPE (gnu_result)))) + && !(TYPE_SIZE (gnu_result_type) + && TYPE_SIZE (TREE_TYPE (gnu_result)) + && (AGGREGATE_TYPE_P (gnu_result_type) + == AGGREGATE_TYPE_P (TREE_TYPE (gnu_result))) + && ((TREE_CODE (TYPE_SIZE (gnu_result_type)) == INTEGER_CST + && (TREE_CODE (TYPE_SIZE (TREE_TYPE (gnu_result))) + != INTEGER_CST)) + || (TREE_CODE (TYPE_SIZE (gnu_result_type)) != INTEGER_CST + && !CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_result_type)) + && (CONTAINS_PLACEHOLDER_P + (TYPE_SIZE (TREE_TYPE (gnu_result)))))) + && !(TREE_CODE (gnu_result_type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (gnu_result_type)))) + { + /* Remove padding only if the inner object is of self-referential + size: in that case it must be an object of unconstrained type + with a default discriminant and we want to avoid copying too + much data. */ + if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_result)) + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (TREE_TYPE (TYPE_FIELDS + (TREE_TYPE (gnu_result)))))) + gnu_result = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_result))), + gnu_result); + } + + else if (TREE_CODE (gnu_result) == LABEL_DECL + || TREE_CODE (gnu_result) == FIELD_DECL + || TREE_CODE (gnu_result) == ERROR_MARK + || (TYPE_NAME (gnu_result_type) + == TYPE_NAME (TREE_TYPE (gnu_result)) + && TREE_CODE (gnu_result_type) == RECORD_TYPE + && TREE_CODE (TREE_TYPE (gnu_result)) == RECORD_TYPE)) + { + /* Remove any padding. */ + if (TYPE_IS_PADDING_P (TREE_TYPE (gnu_result))) + gnu_result = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_result))), + gnu_result); + } + + else if (gnu_result == error_mark_node || gnu_result_type == void_type_node) + gnu_result = error_mark_node; + + else if (TREE_CODE (gnu_result) == CALL_EXPR + && TYPE_IS_PADDING_P (TREE_TYPE (gnu_result)) + && TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_result))) + == gnu_result_type + && CONTAINS_PLACEHOLDER_P (TYPE_SIZE (gnu_result_type))) + ; + + else if (TREE_TYPE (gnu_result) != gnu_result_type) + gnu_result = convert (gnu_result_type, gnu_result); + + /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on the result. */ + while ((TREE_CODE (gnu_result) == NOP_EXPR + || TREE_CODE (gnu_result) == NON_LVALUE_EXPR) + && TREE_TYPE (TREE_OPERAND (gnu_result, 0)) == TREE_TYPE (gnu_result)) + gnu_result = TREE_OPERAND (gnu_result, 0); + + return gnu_result; +} + +/* Subroutine of above to push the exception label stack. GNU_STACK is + a pointer to the stack to update and GNAT_LABEL, if present, is the + label to push onto the stack. */ + +static void +push_exception_label_stack (vec<tree, va_gc> **gnu_stack, Entity_Id gnat_label) +{ + tree gnu_label = (Present (gnat_label) + ? gnat_to_gnu_entity (gnat_label, NULL_TREE, 0) + : NULL_TREE); + + vec_safe_push (*gnu_stack, gnu_label); +} + +/* Record the current code position in GNAT_NODE. */ + +static void +record_code_position (Node_Id gnat_node) +{ + tree stmt_stmt = build1 (STMT_STMT, void_type_node, NULL_TREE); + + add_stmt_with_node (stmt_stmt, gnat_node); + save_gnu_tree (gnat_node, stmt_stmt, true); +} + +/* Insert the code for GNAT_NODE at the position saved for that node. */ + +static void +insert_code_for (Node_Id gnat_node) +{ + STMT_STMT_STMT (get_gnu_tree (gnat_node)) = gnat_to_gnu (gnat_node); + save_gnu_tree (gnat_node, NULL_TREE, true); +} + +/* Start a new statement group chained to the previous group. */ + +void +start_stmt_group (void) +{ + struct stmt_group *group = stmt_group_free_list; + + /* First see if we can get one from the free list. */ + if (group) + stmt_group_free_list = group->previous; + else + group = ggc_alloc_stmt_group (); + + group->previous = current_stmt_group; + group->stmt_list = group->block = group->cleanups = NULL_TREE; + current_stmt_group = group; +} + +/* Add GNU_STMT to the current statement group. If it is an expression with + no effects, it is ignored. */ + +void +add_stmt (tree gnu_stmt) +{ + append_to_statement_list (gnu_stmt, ¤t_stmt_group->stmt_list); +} + +/* Similar, but the statement is always added, regardless of side-effects. */ + +void +add_stmt_force (tree gnu_stmt) +{ + append_to_statement_list_force (gnu_stmt, ¤t_stmt_group->stmt_list); +} + +/* Like add_stmt, but set the location of GNU_STMT to that of GNAT_NODE. */ + +void +add_stmt_with_node (tree gnu_stmt, Node_Id gnat_node) +{ + if (Present (gnat_node)) + set_expr_location_from_node (gnu_stmt, gnat_node); + add_stmt (gnu_stmt); +} + +/* Similar, but the statement is always added, regardless of side-effects. */ + +void +add_stmt_with_node_force (tree gnu_stmt, Node_Id gnat_node) +{ + if (Present (gnat_node)) + set_expr_location_from_node (gnu_stmt, gnat_node); + add_stmt_force (gnu_stmt); +} + +/* Add a declaration statement for GNU_DECL to the current statement group. + Get SLOC from Entity_Id. */ + +void +add_decl_expr (tree gnu_decl, Entity_Id gnat_entity) +{ + tree type = TREE_TYPE (gnu_decl); + tree gnu_stmt, gnu_init, t; + + /* If this is a variable that Gigi is to ignore, we may have been given + an ERROR_MARK. So test for it. We also might have been given a + reference for a renaming. So only do something for a decl. Also + ignore a TYPE_DECL for an UNCONSTRAINED_ARRAY_TYPE. */ + if (!DECL_P (gnu_decl) + || (TREE_CODE (gnu_decl) == TYPE_DECL + && TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)) + return; + + gnu_stmt = build1 (DECL_EXPR, void_type_node, gnu_decl); + + /* If we are external or global, we don't want to output the DECL_EXPR for + this DECL node since we already have evaluated the expressions in the + sizes and positions as globals and doing it again would be wrong. */ + if (DECL_EXTERNAL (gnu_decl) || global_bindings_p ()) + { + /* Mark everything as used to prevent node sharing with subprograms. + Note that walk_tree knows how to deal with TYPE_DECL, but neither + VAR_DECL nor CONST_DECL. This appears to be somewhat arbitrary. */ + MARK_VISITED (gnu_stmt); + if (TREE_CODE (gnu_decl) == VAR_DECL + || TREE_CODE (gnu_decl) == CONST_DECL) + { + MARK_VISITED (DECL_SIZE (gnu_decl)); + MARK_VISITED (DECL_SIZE_UNIT (gnu_decl)); + MARK_VISITED (DECL_INITIAL (gnu_decl)); + } + /* In any case, we have to deal with our own TYPE_ADA_SIZE field. */ + else if (TREE_CODE (gnu_decl) == TYPE_DECL + && RECORD_OR_UNION_TYPE_P (type) + && !TYPE_FAT_POINTER_P (type)) + MARK_VISITED (TYPE_ADA_SIZE (type)); + } + else + add_stmt_with_node (gnu_stmt, gnat_entity); + + /* If this is a variable and an initializer is attached to it, it must be + valid for the context. Similar to init_const in create_var_decl_1. */ + if (TREE_CODE (gnu_decl) == VAR_DECL + && (gnu_init = DECL_INITIAL (gnu_decl)) != NULL_TREE + && (!gnat_types_compatible_p (type, TREE_TYPE (gnu_init)) + || (TREE_STATIC (gnu_decl) + && !initializer_constant_valid_p (gnu_init, + TREE_TYPE (gnu_init))))) + { + /* If GNU_DECL has a padded type, convert it to the unpadded + type so the assignment is done properly. */ + if (TYPE_IS_PADDING_P (type)) + t = convert (TREE_TYPE (TYPE_FIELDS (type)), gnu_decl); + else + t = gnu_decl; + + gnu_stmt = build_binary_op (INIT_EXPR, NULL_TREE, t, gnu_init); + + DECL_INITIAL (gnu_decl) = NULL_TREE; + if (TREE_READONLY (gnu_decl)) + { + TREE_READONLY (gnu_decl) = 0; + DECL_READONLY_ONCE_ELAB (gnu_decl) = 1; + } + + add_stmt_with_node (gnu_stmt, gnat_entity); + } +} + +/* Callback for walk_tree to mark the visited trees rooted at *TP. */ + +static tree +mark_visited_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) +{ + tree t = *tp; + + if (TREE_VISITED (t)) + *walk_subtrees = 0; + + /* Don't mark a dummy type as visited because we want to mark its sizes + and fields once it's filled in. */ + else if (!TYPE_IS_DUMMY_P (t)) + TREE_VISITED (t) = 1; + + if (TYPE_P (t)) + TYPE_SIZES_GIMPLIFIED (t) = 1; + + return NULL_TREE; +} + +/* Mark nodes rooted at T with TREE_VISITED and types as having their + sized gimplified. We use this to indicate all variable sizes and + positions in global types may not be shared by any subprogram. */ + +void +mark_visited (tree t) +{ + walk_tree (&t, mark_visited_r, NULL, NULL); +} + +/* Add GNU_CLEANUP, a cleanup action, to the current code group and + set its location to that of GNAT_NODE if present. */ + +static void +add_cleanup (tree gnu_cleanup, Node_Id gnat_node) +{ + if (Present (gnat_node)) + set_expr_location_from_node (gnu_cleanup, gnat_node); + append_to_statement_list (gnu_cleanup, ¤t_stmt_group->cleanups); +} + +/* Set the BLOCK node corresponding to the current code group to GNU_BLOCK. */ + +void +set_block_for_group (tree gnu_block) +{ + gcc_assert (!current_stmt_group->block); + current_stmt_group->block = gnu_block; +} + +/* Return code corresponding to the current code group. It is normally + a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if + BLOCK or cleanups were set. */ + +tree +end_stmt_group (void) +{ + struct stmt_group *group = current_stmt_group; + tree gnu_retval = group->stmt_list; + + /* If this is a null list, allocate a new STATEMENT_LIST. Then, if there + are cleanups, make a TRY_FINALLY_EXPR. Last, if there is a BLOCK, + make a BIND_EXPR. Note that we nest in that because the cleanup may + reference variables in the block. */ + if (gnu_retval == NULL_TREE) + gnu_retval = alloc_stmt_list (); + + if (group->cleanups) + gnu_retval = build2 (TRY_FINALLY_EXPR, void_type_node, gnu_retval, + group->cleanups); + + if (current_stmt_group->block) + gnu_retval = build3 (BIND_EXPR, void_type_node, BLOCK_VARS (group->block), + gnu_retval, group->block); + + /* Remove this group from the stack and add it to the free list. */ + current_stmt_group = group->previous; + group->previous = stmt_group_free_list; + stmt_group_free_list = group; + + return gnu_retval; +} + +/* Return whether the current statement group may fall through. */ + +static inline bool +stmt_group_may_fallthru (void) +{ + if (current_stmt_group->stmt_list) + return block_may_fallthru (current_stmt_group->stmt_list); + else + return true; +} + +/* Add a list of statements from GNAT_LIST, a possibly-empty list of + statements.*/ + +static void +add_stmt_list (List_Id gnat_list) +{ + Node_Id gnat_node; + + if (Present (gnat_list)) + for (gnat_node = First (gnat_list); Present (gnat_node); + gnat_node = Next (gnat_node)) + add_stmt (gnat_to_gnu (gnat_node)); +} + +/* Build a tree from GNAT_LIST, a possibly-empty list of statements. + If BINDING_P is true, push and pop a binding level around the list. */ + +static tree +build_stmt_group (List_Id gnat_list, bool binding_p) +{ + start_stmt_group (); + if (binding_p) + gnat_pushlevel (); + + add_stmt_list (gnat_list); + if (binding_p) + gnat_poplevel (); + + return end_stmt_group (); +} + +/* Generate GIMPLE in place for the expression at *EXPR_P. */ + +int +gnat_gimplify_expr (tree *expr_p, gimple_seq *pre_p, + gimple_seq *post_p ATTRIBUTE_UNUSED) +{ + tree expr = *expr_p; + tree op; + + if (IS_ADA_STMT (expr)) + return gnat_gimplify_stmt (expr_p); + + switch (TREE_CODE (expr)) + { + case NULL_EXPR: + /* If this is for a scalar, just make a VAR_DECL for it. If for + an aggregate, get a null pointer of the appropriate type and + dereference it. */ + if (AGGREGATE_TYPE_P (TREE_TYPE (expr))) + *expr_p = build1 (INDIRECT_REF, TREE_TYPE (expr), + convert (build_pointer_type (TREE_TYPE (expr)), + integer_zero_node)); + else + { + *expr_p = create_tmp_var (TREE_TYPE (expr), NULL); + TREE_NO_WARNING (*expr_p) = 1; + } + + gimplify_and_add (TREE_OPERAND (expr, 0), pre_p); + return GS_OK; + + case UNCONSTRAINED_ARRAY_REF: + /* We should only do this if we are just elaborating for side-effects, + but we can't know that yet. */ + *expr_p = TREE_OPERAND (*expr_p, 0); + return GS_OK; + + case ADDR_EXPR: + op = TREE_OPERAND (expr, 0); + + /* If we are taking the address of a constant CONSTRUCTOR, make sure it + is put into static memory. We know that it's going to be read-only + given the semantics we have and it must be in static memory when the + reference is in an elaboration procedure. */ + if (TREE_CODE (op) == CONSTRUCTOR && TREE_CONSTANT (op)) + { + tree addr = build_fold_addr_expr (tree_output_constant_def (op)); + *expr_p = fold_convert (TREE_TYPE (expr), addr); + return GS_ALL_DONE; + } + + return GS_UNHANDLED; + + case VIEW_CONVERT_EXPR: + op = TREE_OPERAND (expr, 0); + + /* If we are view-converting a CONSTRUCTOR or a call from an aggregate + type to a scalar one, explicitly create the local temporary. That's + required if the type is passed by reference. */ + if ((TREE_CODE (op) == CONSTRUCTOR || TREE_CODE (op) == CALL_EXPR) + && AGGREGATE_TYPE_P (TREE_TYPE (op)) + && !AGGREGATE_TYPE_P (TREE_TYPE (expr))) + { + tree mod, new_var = create_tmp_var_raw (TREE_TYPE (op), "C"); + gimple_add_tmp_var (new_var); + + mod = build2 (INIT_EXPR, TREE_TYPE (new_var), new_var, op); + gimplify_and_add (mod, pre_p); + + TREE_OPERAND (expr, 0) = new_var; + return GS_OK; + } + + return GS_UNHANDLED; + + case DECL_EXPR: + op = DECL_EXPR_DECL (expr); + + /* The expressions for the RM bounds must be gimplified to ensure that + they are properly elaborated. See gimplify_decl_expr. */ + if ((TREE_CODE (op) == TYPE_DECL || TREE_CODE (op) == VAR_DECL) + && !TYPE_SIZES_GIMPLIFIED (TREE_TYPE (op))) + switch (TREE_CODE (TREE_TYPE (op))) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + case BOOLEAN_TYPE: + case REAL_TYPE: + { + tree type = TYPE_MAIN_VARIANT (TREE_TYPE (op)), t, val; + + val = TYPE_RM_MIN_VALUE (type); + if (val) + { + gimplify_one_sizepos (&val, pre_p); + for (t = type; t; t = TYPE_NEXT_VARIANT (t)) + SET_TYPE_RM_MIN_VALUE (t, val); + } + + val = TYPE_RM_MAX_VALUE (type); + if (val) + { + gimplify_one_sizepos (&val, pre_p); + for (t = type; t; t = TYPE_NEXT_VARIANT (t)) + SET_TYPE_RM_MAX_VALUE (t, val); + } + + } + break; + + default: + break; + } + + /* ... fall through ... */ + + default: + return GS_UNHANDLED; + } +} + +/* Generate GIMPLE in place for the statement at *STMT_P. */ + +static enum gimplify_status +gnat_gimplify_stmt (tree *stmt_p) +{ + tree stmt = *stmt_p; + + switch (TREE_CODE (stmt)) + { + case STMT_STMT: + *stmt_p = STMT_STMT_STMT (stmt); + return GS_OK; + + case LOOP_STMT: + { + tree gnu_start_label = create_artificial_label (input_location); + tree gnu_cond = LOOP_STMT_COND (stmt); + tree gnu_update = LOOP_STMT_UPDATE (stmt); + tree gnu_end_label = LOOP_STMT_LABEL (stmt); + tree t; + + /* Build the condition expression from the test, if any. */ + if (gnu_cond) + gnu_cond + = build3 (COND_EXPR, void_type_node, gnu_cond, alloc_stmt_list (), + build1 (GOTO_EXPR, void_type_node, gnu_end_label)); + + /* Set to emit the statements of the loop. */ + *stmt_p = NULL_TREE; + + /* We first emit the start label and then a conditional jump to the + end label if there's a top condition, then the update if it's at + the top, then the body of the loop, then a conditional jump to + the end label if there's a bottom condition, then the update if + it's at the bottom, and finally a jump to the start label and the + definition of the end label. */ + append_to_statement_list (build1 (LABEL_EXPR, void_type_node, + gnu_start_label), + stmt_p); + + if (gnu_cond && !LOOP_STMT_BOTTOM_COND_P (stmt)) + append_to_statement_list (gnu_cond, stmt_p); + + if (gnu_update && LOOP_STMT_TOP_UPDATE_P (stmt)) + append_to_statement_list (gnu_update, stmt_p); + + append_to_statement_list (LOOP_STMT_BODY (stmt), stmt_p); + + if (gnu_cond && LOOP_STMT_BOTTOM_COND_P (stmt)) + append_to_statement_list (gnu_cond, stmt_p); + + if (gnu_update && !LOOP_STMT_TOP_UPDATE_P (stmt)) + append_to_statement_list (gnu_update, stmt_p); + + t = build1 (GOTO_EXPR, void_type_node, gnu_start_label); + SET_EXPR_LOCATION (t, DECL_SOURCE_LOCATION (gnu_end_label)); + append_to_statement_list (t, stmt_p); + + append_to_statement_list (build1 (LABEL_EXPR, void_type_node, + gnu_end_label), + stmt_p); + return GS_OK; + } + + case EXIT_STMT: + /* Build a statement to jump to the corresponding end label, then + see if it needs to be conditional. */ + *stmt_p = build1 (GOTO_EXPR, void_type_node, EXIT_STMT_LABEL (stmt)); + if (EXIT_STMT_COND (stmt)) + *stmt_p = build3 (COND_EXPR, void_type_node, + EXIT_STMT_COND (stmt), *stmt_p, alloc_stmt_list ()); + return GS_OK; + + default: + gcc_unreachable (); + } +} + +/* Force references to each of the entities in packages withed by GNAT_NODE. + Operate recursively but check that we aren't elaborating something more + than once. + + This routine is exclusively called in type_annotate mode, to compute DDA + information for types in withed units, for ASIS use. */ + +static void +elaborate_all_entities (Node_Id gnat_node) +{ + Entity_Id gnat_with_clause, gnat_entity; + + /* Process each unit only once. As we trace the context of all relevant + units transitively, including generic bodies, we may encounter the + same generic unit repeatedly. */ + if (!present_gnu_tree (gnat_node)) + save_gnu_tree (gnat_node, integer_zero_node, true); + + /* Save entities in all context units. A body may have an implicit_with + on its own spec, if the context includes a child unit, so don't save + the spec twice. */ + for (gnat_with_clause = First (Context_Items (gnat_node)); + Present (gnat_with_clause); + gnat_with_clause = Next (gnat_with_clause)) + if (Nkind (gnat_with_clause) == N_With_Clause + && !present_gnu_tree (Library_Unit (gnat_with_clause)) + && Library_Unit (gnat_with_clause) != Library_Unit (Cunit (Main_Unit))) + { + elaborate_all_entities (Library_Unit (gnat_with_clause)); + + if (Ekind (Entity (Name (gnat_with_clause))) == E_Package) + { + for (gnat_entity = First_Entity (Entity (Name (gnat_with_clause))); + Present (gnat_entity); + gnat_entity = Next_Entity (gnat_entity)) + if (Is_Public (gnat_entity) + && Convention (gnat_entity) != Convention_Intrinsic + && Ekind (gnat_entity) != E_Package + && Ekind (gnat_entity) != E_Package_Body + && Ekind (gnat_entity) != E_Operator + && !(IN (Ekind (gnat_entity), Type_Kind) + && !Is_Frozen (gnat_entity)) + && !((Ekind (gnat_entity) == E_Procedure + || Ekind (gnat_entity) == E_Function) + && Is_Intrinsic_Subprogram (gnat_entity)) + && !IN (Ekind (gnat_entity), Named_Kind) + && !IN (Ekind (gnat_entity), Generic_Unit_Kind)) + gnat_to_gnu_entity (gnat_entity, NULL_TREE, 0); + } + else if (Ekind (Entity (Name (gnat_with_clause))) == E_Generic_Package) + { + Node_Id gnat_body + = Corresponding_Body (Unit (Library_Unit (gnat_with_clause))); + + /* Retrieve compilation unit node of generic body. */ + while (Present (gnat_body) + && Nkind (gnat_body) != N_Compilation_Unit) + gnat_body = Parent (gnat_body); + + /* If body is available, elaborate its context. */ + if (Present (gnat_body)) + elaborate_all_entities (gnat_body); + } + } + + if (Nkind (Unit (gnat_node)) == N_Package_Body) + elaborate_all_entities (Library_Unit (gnat_node)); +} + +/* Do the processing of GNAT_NODE, an N_Freeze_Entity. */ + +static void +process_freeze_entity (Node_Id gnat_node) +{ + const Entity_Id gnat_entity = Entity (gnat_node); + const Entity_Kind kind = Ekind (gnat_entity); + tree gnu_old, gnu_new; + + /* If this is a package, we need to generate code for the package. */ + if (kind == E_Package) + { + insert_code_for + (Parent (Corresponding_Body + (Parent (Declaration_Node (gnat_entity))))); + return; + } + + /* Don't do anything for class-wide types as they are always transformed + into their root type. */ + if (kind == E_Class_Wide_Type) + return; + + /* Check for an old definition. This freeze node might be for an Itype. */ + gnu_old + = present_gnu_tree (gnat_entity) ? get_gnu_tree (gnat_entity) : NULL_TREE; + + /* If this entity has an address representation clause, GNU_OLD is the + address, so discard it here. */ + if (Present (Address_Clause (gnat_entity))) + gnu_old = NULL_TREE; + + /* Don't do anything for subprograms that may have been elaborated before + their freeze nodes. This can happen, for example, because of an inner + call in an instance body or because of previous compilation of a spec + for inlining purposes. */ + if (gnu_old + && ((TREE_CODE (gnu_old) == FUNCTION_DECL + && (kind == E_Function || kind == E_Procedure)) + || (TREE_CODE (TREE_TYPE (gnu_old)) == FUNCTION_TYPE + && kind == E_Subprogram_Type))) + return; + + /* If we have a non-dummy type old tree, we have nothing to do, except + aborting if this is the public view of a private type whose full view was + not delayed, as this node was never delayed as it should have been. We + let this happen for concurrent types and their Corresponding_Record_Type, + however, because each might legitimately be elaborated before its own + freeze node, e.g. while processing the other. */ + if (gnu_old + && !(TREE_CODE (gnu_old) == TYPE_DECL + && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_old)))) + { + gcc_assert ((IN (kind, Incomplete_Or_Private_Kind) + && Present (Full_View (gnat_entity)) + && No (Freeze_Node (Full_View (gnat_entity)))) + || Is_Concurrent_Type (gnat_entity) + || (IN (kind, Record_Kind) + && Is_Concurrent_Record_Type (gnat_entity))); + return; + } + + /* Reset the saved tree, if any, and elaborate the object or type for real. + If there is a full view, elaborate it and use the result. And, if this + is the root type of a class-wide type, reuse it for the latter. */ + if (gnu_old) + { + save_gnu_tree (gnat_entity, NULL_TREE, false); + if (IN (kind, Incomplete_Or_Private_Kind) + && Present (Full_View (gnat_entity)) + && present_gnu_tree (Full_View (gnat_entity))) + save_gnu_tree (Full_View (gnat_entity), NULL_TREE, false); + if (IN (kind, Type_Kind) + && Present (Class_Wide_Type (gnat_entity)) + && Root_Type (Class_Wide_Type (gnat_entity)) == gnat_entity) + save_gnu_tree (Class_Wide_Type (gnat_entity), NULL_TREE, false); + } + + if (IN (kind, Incomplete_Or_Private_Kind) + && Present (Full_View (gnat_entity))) + { + gnu_new = gnat_to_gnu_entity (Full_View (gnat_entity), NULL_TREE, 1); + + /* Propagate back-annotations from full view to partial view. */ + if (Unknown_Alignment (gnat_entity)) + Set_Alignment (gnat_entity, Alignment (Full_View (gnat_entity))); + + if (Unknown_Esize (gnat_entity)) + Set_Esize (gnat_entity, Esize (Full_View (gnat_entity))); + + if (Unknown_RM_Size (gnat_entity)) + Set_RM_Size (gnat_entity, RM_Size (Full_View (gnat_entity))); + + /* The above call may have defined this entity (the simplest example + of this is when we have a private enumeral type since the bounds + will have the public view). */ + if (!present_gnu_tree (gnat_entity)) + save_gnu_tree (gnat_entity, gnu_new, false); + } + else + { + tree gnu_init + = (Nkind (Declaration_Node (gnat_entity)) == N_Object_Declaration + && present_gnu_tree (Declaration_Node (gnat_entity))) + ? get_gnu_tree (Declaration_Node (gnat_entity)) : NULL_TREE; + + gnu_new = gnat_to_gnu_entity (gnat_entity, gnu_init, 1); + } + + if (IN (kind, Type_Kind) + && Present (Class_Wide_Type (gnat_entity)) + && Root_Type (Class_Wide_Type (gnat_entity)) == gnat_entity) + save_gnu_tree (Class_Wide_Type (gnat_entity), gnu_new, false); + + /* If we have an old type and we've made pointers to this type, update those + pointers. If this is a Taft amendment type in the main unit, we need to + mark the type as used since other units referencing it don't see the full + declaration and, therefore, cannot mark it as used themselves. */ + if (gnu_old) + { + update_pointer_to (TYPE_MAIN_VARIANT (TREE_TYPE (gnu_old)), + TREE_TYPE (gnu_new)); + if (DECL_TAFT_TYPE_P (gnu_old)) + used_types_insert (TREE_TYPE (gnu_new)); + } +} + +/* Elaborate decls in the lists GNAT_DECLS and GNAT_DECLS2, if present. + We make two passes, one to elaborate anything other than bodies (but + we declare a function if there was no spec). The second pass + elaborates the bodies. + + GNAT_END_LIST gives the element in the list past the end. Normally, + this is Empty, but can be First_Real_Statement for a + Handled_Sequence_Of_Statements. + + We make a complete pass through both lists if PASS1P is true, then make + the second pass over both lists if PASS2P is true. The lists usually + correspond to the public and private parts of a package. */ + +static void +process_decls (List_Id gnat_decls, List_Id gnat_decls2, + Node_Id gnat_end_list, bool pass1p, bool pass2p) +{ + List_Id gnat_decl_array[2]; + Node_Id gnat_decl; + int i; + + gnat_decl_array[0] = gnat_decls, gnat_decl_array[1] = gnat_decls2; + + if (pass1p) + for (i = 0; i <= 1; i++) + if (Present (gnat_decl_array[i])) + for (gnat_decl = First (gnat_decl_array[i]); + gnat_decl != gnat_end_list; gnat_decl = Next (gnat_decl)) + { + /* For package specs, we recurse inside the declarations, + thus taking the two pass approach inside the boundary. */ + if (Nkind (gnat_decl) == N_Package_Declaration + && (Nkind (Specification (gnat_decl) + == N_Package_Specification))) + process_decls (Visible_Declarations (Specification (gnat_decl)), + Private_Declarations (Specification (gnat_decl)), + Empty, true, false); + + /* Similarly for any declarations in the actions of a + freeze node. */ + else if (Nkind (gnat_decl) == N_Freeze_Entity) + { + process_freeze_entity (gnat_decl); + process_decls (Actions (gnat_decl), Empty, Empty, true, false); + } + + /* Package bodies with freeze nodes get their elaboration deferred + until the freeze node, but the code must be placed in the right + place, so record the code position now. */ + else if (Nkind (gnat_decl) == N_Package_Body + && Present (Freeze_Node (Corresponding_Spec (gnat_decl)))) + record_code_position (gnat_decl); + + else if (Nkind (gnat_decl) == N_Package_Body_Stub + && Present (Library_Unit (gnat_decl)) + && Present (Freeze_Node + (Corresponding_Spec + (Proper_Body (Unit + (Library_Unit (gnat_decl))))))) + record_code_position + (Proper_Body (Unit (Library_Unit (gnat_decl)))); + + /* We defer most subprogram bodies to the second pass. */ + else if (Nkind (gnat_decl) == N_Subprogram_Body) + { + if (Acts_As_Spec (gnat_decl)) + { + Node_Id gnat_subprog_id = Defining_Entity (gnat_decl); + + if (Ekind (gnat_subprog_id) != E_Generic_Procedure + && Ekind (gnat_subprog_id) != E_Generic_Function) + gnat_to_gnu_entity (gnat_subprog_id, NULL_TREE, 1); + } + } + + /* For bodies and stubs that act as their own specs, the entity + itself must be elaborated in the first pass, because it may + be used in other declarations. */ + else if (Nkind (gnat_decl) == N_Subprogram_Body_Stub) + { + Node_Id gnat_subprog_id + = Defining_Entity (Specification (gnat_decl)); + + if (Ekind (gnat_subprog_id) != E_Subprogram_Body + && Ekind (gnat_subprog_id) != E_Generic_Procedure + && Ekind (gnat_subprog_id) != E_Generic_Function) + gnat_to_gnu_entity (gnat_subprog_id, NULL_TREE, 1); + } + + /* Concurrent stubs stand for the corresponding subprogram bodies, + which are deferred like other bodies. */ + else if (Nkind (gnat_decl) == N_Task_Body_Stub + || Nkind (gnat_decl) == N_Protected_Body_Stub) + ; + + else + add_stmt (gnat_to_gnu (gnat_decl)); + } + + /* Here we elaborate everything we deferred above except for package bodies, + which are elaborated at their freeze nodes. Note that we must also + go inside things (package specs and freeze nodes) the first pass did. */ + if (pass2p) + for (i = 0; i <= 1; i++) + if (Present (gnat_decl_array[i])) + for (gnat_decl = First (gnat_decl_array[i]); + gnat_decl != gnat_end_list; gnat_decl = Next (gnat_decl)) + { + if (Nkind (gnat_decl) == N_Subprogram_Body + || Nkind (gnat_decl) == N_Subprogram_Body_Stub + || Nkind (gnat_decl) == N_Task_Body_Stub + || Nkind (gnat_decl) == N_Protected_Body_Stub) + add_stmt (gnat_to_gnu (gnat_decl)); + + else if (Nkind (gnat_decl) == N_Package_Declaration + && (Nkind (Specification (gnat_decl) + == N_Package_Specification))) + process_decls (Visible_Declarations (Specification (gnat_decl)), + Private_Declarations (Specification (gnat_decl)), + Empty, false, true); + + else if (Nkind (gnat_decl) == N_Freeze_Entity) + process_decls (Actions (gnat_decl), Empty, Empty, false, true); + } +} + +/* Make a unary operation of kind CODE using build_unary_op, but guard + the operation by an overflow check. CODE can be one of NEGATE_EXPR + or ABS_EXPR. GNU_TYPE is the type desired for the result. Usually + the operation is to be performed in that type. GNAT_NODE is the gnat + node conveying the source location for which the error should be + signaled. */ + +static tree +build_unary_op_trapv (enum tree_code code, tree gnu_type, tree operand, + Node_Id gnat_node) +{ + gcc_assert (code == NEGATE_EXPR || code == ABS_EXPR); + + operand = gnat_protect_expr (operand); + + return emit_check (build_binary_op (EQ_EXPR, boolean_type_node, + operand, TYPE_MIN_VALUE (gnu_type)), + build_unary_op (code, gnu_type, operand), + CE_Overflow_Check_Failed, gnat_node); +} + +/* Make a binary operation of kind CODE using build_binary_op, but guard + the operation by an overflow check. CODE can be one of PLUS_EXPR, + MINUS_EXPR or MULT_EXPR. GNU_TYPE is the type desired for the result. + Usually the operation is to be performed in that type. GNAT_NODE is + the GNAT node conveying the source location for which the error should + be signaled. */ + +static tree +build_binary_op_trapv (enum tree_code code, tree gnu_type, tree left, + tree right, Node_Id gnat_node) +{ + tree lhs = gnat_protect_expr (left); + tree rhs = gnat_protect_expr (right); + tree type_max = TYPE_MAX_VALUE (gnu_type); + tree type_min = TYPE_MIN_VALUE (gnu_type); + tree gnu_expr; + tree tmp1, tmp2; + tree zero = convert (gnu_type, integer_zero_node); + tree rhs_lt_zero; + tree check_pos; + tree check_neg; + tree check; + int precision = TYPE_PRECISION (gnu_type); + + gcc_assert (!(precision & (precision - 1))); /* ensure power of 2 */ + + /* Prefer a constant or known-positive rhs to simplify checks. */ + if (!TREE_CONSTANT (rhs) + && commutative_tree_code (code) + && (TREE_CONSTANT (lhs) || (!tree_expr_nonnegative_p (rhs) + && tree_expr_nonnegative_p (lhs)))) + { + tree tmp = lhs; + lhs = rhs; + rhs = tmp; + } + + rhs_lt_zero = tree_expr_nonnegative_p (rhs) + ? boolean_false_node + : build_binary_op (LT_EXPR, boolean_type_node, rhs, zero); + + /* ??? Should use more efficient check for operand_equal_p (lhs, rhs, 0) */ + + /* Try a few strategies that may be cheaper than the general + code at the end of the function, if the rhs is not known. + The strategies are: + - Call library function for 64-bit multiplication (complex) + - Widen, if input arguments are sufficiently small + - Determine overflow using wrapped result for addition/subtraction. */ + + if (!TREE_CONSTANT (rhs)) + { + /* Even for add/subtract double size to get another base type. */ + int needed_precision = precision * 2; + + if (code == MULT_EXPR && precision == 64) + { + tree int_64 = gnat_type_for_size (64, 0); + + return convert (gnu_type, build_call_n_expr (mulv64_decl, 2, + convert (int_64, lhs), + convert (int_64, rhs))); + } + + else if (needed_precision <= BITS_PER_WORD + || (code == MULT_EXPR + && needed_precision <= LONG_LONG_TYPE_SIZE)) + { + tree wide_type = gnat_type_for_size (needed_precision, 0); + + tree wide_result = build_binary_op (code, wide_type, + convert (wide_type, lhs), + convert (wide_type, rhs)); + + tree check = build_binary_op + (TRUTH_ORIF_EXPR, boolean_type_node, + build_binary_op (LT_EXPR, boolean_type_node, wide_result, + convert (wide_type, type_min)), + build_binary_op (GT_EXPR, boolean_type_node, wide_result, + convert (wide_type, type_max))); + + tree result = convert (gnu_type, wide_result); + + return + emit_check (check, result, CE_Overflow_Check_Failed, gnat_node); + } + + else if (code == PLUS_EXPR || code == MINUS_EXPR) + { + tree unsigned_type = gnat_type_for_size (precision, 1); + tree wrapped_expr = convert + (gnu_type, build_binary_op (code, unsigned_type, + convert (unsigned_type, lhs), + convert (unsigned_type, rhs))); + + tree result = convert + (gnu_type, build_binary_op (code, gnu_type, lhs, rhs)); + + /* Overflow when (rhs < 0) ^ (wrapped_expr < lhs)), for addition + or when (rhs < 0) ^ (wrapped_expr > lhs) for subtraction. */ + tree check = build_binary_op + (TRUTH_XOR_EXPR, boolean_type_node, rhs_lt_zero, + build_binary_op (code == PLUS_EXPR ? LT_EXPR : GT_EXPR, + boolean_type_node, wrapped_expr, lhs)); + + return + emit_check (check, result, CE_Overflow_Check_Failed, gnat_node); + } + } + + switch (code) + { + case PLUS_EXPR: + /* When rhs >= 0, overflow when lhs > type_max - rhs. */ + check_pos = build_binary_op (GT_EXPR, boolean_type_node, lhs, + build_binary_op (MINUS_EXPR, gnu_type, + type_max, rhs)), + + /* When rhs < 0, overflow when lhs < type_min - rhs. */ + check_neg = build_binary_op (LT_EXPR, boolean_type_node, lhs, + build_binary_op (MINUS_EXPR, gnu_type, + type_min, rhs)); + break; + + case MINUS_EXPR: + /* When rhs >= 0, overflow when lhs < type_min + rhs. */ + check_pos = build_binary_op (LT_EXPR, boolean_type_node, lhs, + build_binary_op (PLUS_EXPR, gnu_type, + type_min, rhs)), + + /* When rhs < 0, overflow when lhs > type_max + rhs. */ + check_neg = build_binary_op (GT_EXPR, boolean_type_node, lhs, + build_binary_op (PLUS_EXPR, gnu_type, + type_max, rhs)); + break; + + case MULT_EXPR: + /* The check here is designed to be efficient if the rhs is constant, + but it will work for any rhs by using integer division. + Four different check expressions determine whether X * C overflows, + depending on C. + C == 0 => false + C > 0 => X > type_max / C || X < type_min / C + C == -1 => X == type_min + C < -1 => X > type_min / C || X < type_max / C */ + + tmp1 = build_binary_op (TRUNC_DIV_EXPR, gnu_type, type_max, rhs); + tmp2 = build_binary_op (TRUNC_DIV_EXPR, gnu_type, type_min, rhs); + + check_pos + = build_binary_op (TRUTH_ANDIF_EXPR, boolean_type_node, + build_binary_op (NE_EXPR, boolean_type_node, zero, + rhs), + build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + build_binary_op (GT_EXPR, + boolean_type_node, + lhs, tmp1), + build_binary_op (LT_EXPR, + boolean_type_node, + lhs, tmp2))); + + check_neg + = fold_build3 (COND_EXPR, boolean_type_node, + build_binary_op (EQ_EXPR, boolean_type_node, rhs, + build_int_cst (gnu_type, -1)), + build_binary_op (EQ_EXPR, boolean_type_node, lhs, + type_min), + build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + build_binary_op (GT_EXPR, + boolean_type_node, + lhs, tmp2), + build_binary_op (LT_EXPR, + boolean_type_node, + lhs, tmp1))); + break; + + default: + gcc_unreachable(); + } + + gnu_expr = build_binary_op (code, gnu_type, lhs, rhs); + + /* If we can fold the expression to a constant, just return it. + The caller will deal with overflow, no need to generate a check. */ + if (TREE_CONSTANT (gnu_expr)) + return gnu_expr; + + check = fold_build3 (COND_EXPR, boolean_type_node, rhs_lt_zero, check_neg, + check_pos); + + return emit_check (check, gnu_expr, CE_Overflow_Check_Failed, gnat_node); +} + +/* Emit code for a range check. GNU_EXPR is the expression to be checked, + GNAT_RANGE_TYPE the gnat type or subtype containing the bounds against + which we have to check. GNAT_NODE is the GNAT node conveying the source + location for which the error should be signaled. */ + +static tree +emit_range_check (tree gnu_expr, Entity_Id gnat_range_type, Node_Id gnat_node) +{ + tree gnu_range_type = get_unpadded_type (gnat_range_type); + tree gnu_compare_type = get_base_type (TREE_TYPE (gnu_expr)); + + /* If GNU_EXPR has GNAT_RANGE_TYPE as its base type, no check is needed. + This can for example happen when translating 'Val or 'Value. */ + if (gnu_compare_type == gnu_range_type) + return gnu_expr; + + /* Range checks can only be applied to types with ranges. */ + gcc_assert (INTEGRAL_TYPE_P (gnu_range_type) + || SCALAR_FLOAT_TYPE_P (gnu_range_type)); + + /* If GNU_EXPR has an integral type that is narrower than GNU_RANGE_TYPE, + we can't do anything since we might be truncating the bounds. No + check is needed in this case. */ + if (INTEGRAL_TYPE_P (TREE_TYPE (gnu_expr)) + && (TYPE_PRECISION (gnu_compare_type) + < TYPE_PRECISION (get_base_type (gnu_range_type)))) + return gnu_expr; + + /* Checked expressions must be evaluated only once. */ + gnu_expr = gnat_protect_expr (gnu_expr); + + /* Note that the form of the check is + (not (expr >= lo)) or (not (expr <= hi)) + the reason for this slightly convoluted form is that NaNs + are not considered to be in range in the float case. */ + return emit_check + (build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + invert_truthvalue + (build_binary_op (GE_EXPR, boolean_type_node, + convert (gnu_compare_type, gnu_expr), + convert (gnu_compare_type, + TYPE_MIN_VALUE + (gnu_range_type)))), + invert_truthvalue + (build_binary_op (LE_EXPR, boolean_type_node, + convert (gnu_compare_type, gnu_expr), + convert (gnu_compare_type, + TYPE_MAX_VALUE + (gnu_range_type))))), + gnu_expr, CE_Range_Check_Failed, gnat_node); +} + +/* Emit code for an index check. GNU_ARRAY_OBJECT is the array object which + we are about to index, GNU_EXPR is the index expression to be checked, + GNU_LOW and GNU_HIGH are the lower and upper bounds against which GNU_EXPR + has to be checked. Note that for index checking we cannot simply use the + emit_range_check function (although very similar code needs to be generated + in both cases) since for index checking the array type against which we are + checking the indices may be unconstrained and consequently we need to get + the actual index bounds from the array object itself (GNU_ARRAY_OBJECT). + The place where we need to do that is in subprograms having unconstrained + array formal parameters. GNAT_NODE is the GNAT node conveying the source + location for which the error should be signaled. */ + +static tree +emit_index_check (tree gnu_array_object, tree gnu_expr, tree gnu_low, + tree gnu_high, Node_Id gnat_node) +{ + tree gnu_expr_check; + + /* Checked expressions must be evaluated only once. */ + gnu_expr = gnat_protect_expr (gnu_expr); + + /* Must do this computation in the base type in case the expression's + type is an unsigned subtypes. */ + gnu_expr_check = convert (get_base_type (TREE_TYPE (gnu_expr)), gnu_expr); + + /* If GNU_LOW or GNU_HIGH are a PLACEHOLDER_EXPR, qualify them by + the object we are handling. */ + gnu_low = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_low, gnu_array_object); + gnu_high = SUBSTITUTE_PLACEHOLDER_IN_EXPR (gnu_high, gnu_array_object); + + return emit_check + (build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, + build_binary_op (LT_EXPR, boolean_type_node, + gnu_expr_check, + convert (TREE_TYPE (gnu_expr_check), + gnu_low)), + build_binary_op (GT_EXPR, boolean_type_node, + gnu_expr_check, + convert (TREE_TYPE (gnu_expr_check), + gnu_high))), + gnu_expr, CE_Index_Check_Failed, gnat_node); +} + +/* GNU_COND contains the condition corresponding to an access, discriminant or + range check of value GNU_EXPR. Build a COND_EXPR that returns GNU_EXPR if + GNU_COND is false and raises a CONSTRAINT_ERROR if GNU_COND is true. + REASON is the code that says why the exception was raised. GNAT_NODE is + the GNAT node conveying the source location for which the error should be + signaled. */ + +static tree +emit_check (tree gnu_cond, tree gnu_expr, int reason, Node_Id gnat_node) +{ + tree gnu_call + = build_call_raise (reason, gnat_node, N_Raise_Constraint_Error); + tree gnu_result + = fold_build3 (COND_EXPR, TREE_TYPE (gnu_expr), gnu_cond, + build2 (COMPOUND_EXPR, TREE_TYPE (gnu_expr), gnu_call, + convert (TREE_TYPE (gnu_expr), integer_zero_node)), + gnu_expr); + + /* GNU_RESULT has side effects if and only if GNU_EXPR has: + we don't need to evaluate it just for the check. */ + TREE_SIDE_EFFECTS (gnu_result) = TREE_SIDE_EFFECTS (gnu_expr); + + return gnu_result; +} + +/* Return an expression that converts GNU_EXPR to GNAT_TYPE, doing overflow + checks if OVERFLOW_P is true and range checks if RANGE_P is true. + GNAT_TYPE is known to be an integral type. If TRUNCATE_P true, do a + float to integer conversion with truncation; otherwise round. + GNAT_NODE is the GNAT node conveying the source location for which the + error should be signaled. */ + +static tree +convert_with_check (Entity_Id gnat_type, tree gnu_expr, bool overflowp, + bool rangep, bool truncatep, Node_Id gnat_node) +{ + tree gnu_type = get_unpadded_type (gnat_type); + tree gnu_in_type = TREE_TYPE (gnu_expr); + tree gnu_in_basetype = get_base_type (gnu_in_type); + tree gnu_base_type = get_base_type (gnu_type); + tree gnu_result = gnu_expr; + + /* If we are not doing any checks, the output is an integral type, and + the input is not a floating type, just do the conversion. This + shortcut is required to avoid problems with packed array types + and simplifies code in all cases anyway. */ + if (!rangep && !overflowp && INTEGRAL_TYPE_P (gnu_base_type) + && !FLOAT_TYPE_P (gnu_in_type)) + return convert (gnu_type, gnu_expr); + + /* First convert the expression to its base type. This + will never generate code, but makes the tests below much simpler. + But don't do this if converting from an integer type to an unconstrained + array type since then we need to get the bounds from the original + (unpacked) type. */ + if (TREE_CODE (gnu_type) != UNCONSTRAINED_ARRAY_TYPE) + gnu_result = convert (gnu_in_basetype, gnu_result); + + /* If overflow checks are requested, we need to be sure the result will + fit in the output base type. But don't do this if the input + is integer and the output floating-point. */ + if (overflowp + && !(FLOAT_TYPE_P (gnu_base_type) && INTEGRAL_TYPE_P (gnu_in_basetype))) + { + /* Ensure GNU_EXPR only gets evaluated once. */ + tree gnu_input = gnat_protect_expr (gnu_result); + tree gnu_cond = boolean_false_node; + tree gnu_in_lb = TYPE_MIN_VALUE (gnu_in_basetype); + tree gnu_in_ub = TYPE_MAX_VALUE (gnu_in_basetype); + tree gnu_out_lb = TYPE_MIN_VALUE (gnu_base_type); + tree gnu_out_ub = TYPE_MAX_VALUE (gnu_base_type); + + /* Convert the lower bounds to signed types, so we're sure we're + comparing them properly. Likewise, convert the upper bounds + to unsigned types. */ + if (INTEGRAL_TYPE_P (gnu_in_basetype) && TYPE_UNSIGNED (gnu_in_basetype)) + gnu_in_lb = convert (gnat_signed_type (gnu_in_basetype), gnu_in_lb); + + if (INTEGRAL_TYPE_P (gnu_in_basetype) + && !TYPE_UNSIGNED (gnu_in_basetype)) + gnu_in_ub = convert (gnat_unsigned_type (gnu_in_basetype), gnu_in_ub); + + if (INTEGRAL_TYPE_P (gnu_base_type) && TYPE_UNSIGNED (gnu_base_type)) + gnu_out_lb = convert (gnat_signed_type (gnu_base_type), gnu_out_lb); + + if (INTEGRAL_TYPE_P (gnu_base_type) && !TYPE_UNSIGNED (gnu_base_type)) + gnu_out_ub = convert (gnat_unsigned_type (gnu_base_type), gnu_out_ub); + + /* Check each bound separately and only if the result bound + is tighter than the bound on the input type. Note that all the + types are base types, so the bounds must be constant. Also, + the comparison is done in the base type of the input, which + always has the proper signedness. First check for input + integer (which means output integer), output float (which means + both float), or mixed, in which case we always compare. + Note that we have to do the comparison which would *fail* in the + case of an error since if it's an FP comparison and one of the + values is a NaN or Inf, the comparison will fail. */ + if (INTEGRAL_TYPE_P (gnu_in_basetype) + ? tree_int_cst_lt (gnu_in_lb, gnu_out_lb) + : (FLOAT_TYPE_P (gnu_base_type) + ? REAL_VALUES_LESS (TREE_REAL_CST (gnu_in_lb), + TREE_REAL_CST (gnu_out_lb)) + : 1)) + gnu_cond + = invert_truthvalue + (build_binary_op (GE_EXPR, boolean_type_node, + gnu_input, convert (gnu_in_basetype, + gnu_out_lb))); + + if (INTEGRAL_TYPE_P (gnu_in_basetype) + ? tree_int_cst_lt (gnu_out_ub, gnu_in_ub) + : (FLOAT_TYPE_P (gnu_base_type) + ? REAL_VALUES_LESS (TREE_REAL_CST (gnu_out_ub), + TREE_REAL_CST (gnu_in_lb)) + : 1)) + gnu_cond + = build_binary_op (TRUTH_ORIF_EXPR, boolean_type_node, gnu_cond, + invert_truthvalue + (build_binary_op (LE_EXPR, boolean_type_node, + gnu_input, + convert (gnu_in_basetype, + gnu_out_ub)))); + + if (!integer_zerop (gnu_cond)) + gnu_result = emit_check (gnu_cond, gnu_input, + CE_Overflow_Check_Failed, gnat_node); + } + + /* Now convert to the result base type. If this is a non-truncating + float-to-integer conversion, round. */ + if (INTEGRAL_TYPE_P (gnu_base_type) && FLOAT_TYPE_P (gnu_in_basetype) + && !truncatep) + { + REAL_VALUE_TYPE half_minus_pred_half, pred_half; + tree gnu_conv, gnu_zero, gnu_comp, calc_type; + tree gnu_pred_half, gnu_add_pred_half, gnu_subtract_pred_half; + const struct real_format *fmt; + + /* The following calculations depend on proper rounding to even + of each arithmetic operation. In order to prevent excess + precision from spoiling this property, use the widest hardware + floating-point type if FP_ARITH_MAY_WIDEN is true. */ + calc_type + = FP_ARITH_MAY_WIDEN ? longest_float_type_node : gnu_in_basetype; + + /* FIXME: Should not have padding in the first place. */ + if (TYPE_IS_PADDING_P (calc_type)) + calc_type = TREE_TYPE (TYPE_FIELDS (calc_type)); + + /* Compute the exact value calc_type'Pred (0.5) at compile time. */ + fmt = REAL_MODE_FORMAT (TYPE_MODE (calc_type)); + real_2expN (&half_minus_pred_half, -(fmt->p) - 1, TYPE_MODE (calc_type)); + REAL_ARITHMETIC (pred_half, MINUS_EXPR, dconsthalf, + half_minus_pred_half); + gnu_pred_half = build_real (calc_type, pred_half); + + /* If the input is strictly negative, subtract this value + and otherwise add it from the input. For 0.5, the result + is exactly between 1.0 and the machine number preceding 1.0 + (for calc_type). Since the last bit of 1.0 is even, this 0.5 + will round to 1.0, while all other number with an absolute + value less than 0.5 round to 0.0. For larger numbers exactly + halfway between integers, rounding will always be correct as + the true mathematical result will be closer to the higher + integer compared to the lower one. So, this constant works + for all floating-point numbers. + + The reason to use the same constant with subtract/add instead + of a positive and negative constant is to allow the comparison + to be scheduled in parallel with retrieval of the constant and + conversion of the input to the calc_type (if necessary). */ + + gnu_zero = convert (gnu_in_basetype, integer_zero_node); + gnu_result = gnat_protect_expr (gnu_result); + gnu_conv = convert (calc_type, gnu_result); + gnu_comp + = fold_build2 (GE_EXPR, boolean_type_node, gnu_result, gnu_zero); + gnu_add_pred_half + = fold_build2 (PLUS_EXPR, calc_type, gnu_conv, gnu_pred_half); + gnu_subtract_pred_half + = fold_build2 (MINUS_EXPR, calc_type, gnu_conv, gnu_pred_half); + gnu_result = fold_build3 (COND_EXPR, calc_type, gnu_comp, + gnu_add_pred_half, gnu_subtract_pred_half); + } + + if (TREE_CODE (gnu_base_type) == INTEGER_TYPE + && TYPE_HAS_ACTUAL_BOUNDS_P (gnu_base_type) + && TREE_CODE (gnu_result) == UNCONSTRAINED_ARRAY_REF) + gnu_result = unchecked_convert (gnu_base_type, gnu_result, false); + else + gnu_result = convert (gnu_base_type, gnu_result); + + /* Finally, do the range check if requested. Note that if the result type + is a modular type, the range check is actually an overflow check. */ + if (rangep + || (TREE_CODE (gnu_base_type) == INTEGER_TYPE + && TYPE_MODULAR_P (gnu_base_type) && overflowp)) + gnu_result = emit_range_check (gnu_result, gnat_type, gnat_node); + + return convert (gnu_type, gnu_result); +} + +/* Return true if GNU_EXPR can be directly addressed. This is the case + unless it is an expression involving computation or if it involves a + reference to a bitfield or to an object not sufficiently aligned for + its type. If GNU_TYPE is non-null, return true only if GNU_EXPR can + be directly addressed as an object of this type. + + *** Notes on addressability issues in the Ada compiler *** + + This predicate is necessary in order to bridge the gap between Gigi + and the middle-end about addressability of GENERIC trees. A tree + is said to be addressable if it can be directly addressed, i.e. if + its address can be taken, is a multiple of the type's alignment on + strict-alignment architectures and returns the first storage unit + assigned to the object represented by the tree. + + In the C family of languages, everything is in practice addressable + at the language level, except for bit-fields. This means that these + compilers will take the address of any tree that doesn't represent + a bit-field reference and expect the result to be the first storage + unit assigned to the object. Even in cases where this will result + in unaligned accesses at run time, nothing is supposed to be done + and the program is considered as erroneous instead (see PR c/18287). + + The implicit assumptions made in the middle-end are in keeping with + the C viewpoint described above: + - the address of a bit-field reference is supposed to be never + taken; the compiler (generally) will stop on such a construct, + - any other tree is addressable if it is formally addressable, + i.e. if it is formally allowed to be the operand of ADDR_EXPR. + + In Ada, the viewpoint is the opposite one: nothing is addressable + at the language level unless explicitly declared so. This means + that the compiler will both make sure that the trees representing + references to addressable ("aliased" in Ada parlance) objects are + addressable and make no real attempts at ensuring that the trees + representing references to non-addressable objects are addressable. + + In the first case, Ada is effectively equivalent to C and handing + down the direct result of applying ADDR_EXPR to these trees to the + middle-end works flawlessly. In the second case, Ada cannot afford + to consider the program as erroneous if the address of trees that + are not addressable is requested for technical reasons, unlike C; + as a consequence, the Ada compiler must arrange for either making + sure that this address is not requested in the middle-end or for + compensating by inserting temporaries if it is requested in Gigi. + + The first goal can be achieved because the middle-end should not + request the address of non-addressable trees on its own; the only + exception is for the invocation of low-level block operations like + memcpy, for which the addressability requirements are lower since + the type's alignment can be disregarded. In practice, this means + that Gigi must make sure that such operations cannot be applied to + non-BLKmode bit-fields. + + The second goal is achieved by means of the addressable_p predicate, + which computes whether a temporary must be inserted by Gigi when the + address of a tree is requested; if so, the address of the temporary + will be used in lieu of that of the original tree and some glue code + generated to connect everything together. */ + +static bool +addressable_p (tree gnu_expr, tree gnu_type) +{ + /* For an integral type, the size of the actual type of the object may not + be greater than that of the expected type, otherwise an indirect access + in the latter type wouldn't correctly set all the bits of the object. */ + if (gnu_type + && INTEGRAL_TYPE_P (gnu_type) + && smaller_form_type_p (gnu_type, TREE_TYPE (gnu_expr))) + return false; + + /* The size of the actual type of the object may not be smaller than that + of the expected type, otherwise an indirect access in the latter type + would be larger than the object. But only record types need to be + considered in practice for this case. */ + if (gnu_type + && TREE_CODE (gnu_type) == RECORD_TYPE + && smaller_form_type_p (TREE_TYPE (gnu_expr), gnu_type)) + return false; + + switch (TREE_CODE (gnu_expr)) + { + case VAR_DECL: + case PARM_DECL: + case FUNCTION_DECL: + case RESULT_DECL: + /* All DECLs are addressable: if they are in a register, we can force + them to memory. */ + return true; + + case UNCONSTRAINED_ARRAY_REF: + case INDIRECT_REF: + /* Taking the address of a dereference yields the original pointer. */ + return true; + + case STRING_CST: + case INTEGER_CST: + /* Taking the address yields a pointer to the constant pool. */ + return true; + + case CONSTRUCTOR: + /* Taking the address of a static constructor yields a pointer to the + tree constant pool. */ + return TREE_STATIC (gnu_expr) ? true : false; + + case NULL_EXPR: + case SAVE_EXPR: + case CALL_EXPR: + case PLUS_EXPR: + case MINUS_EXPR: + case BIT_IOR_EXPR: + case BIT_XOR_EXPR: + case BIT_AND_EXPR: + case BIT_NOT_EXPR: + /* All rvalues are deemed addressable since taking their address will + force a temporary to be created by the middle-end. */ + return true; + + case COMPOUND_EXPR: + /* The address of a compound expression is that of its 2nd operand. */ + return addressable_p (TREE_OPERAND (gnu_expr, 1), gnu_type); + + case COND_EXPR: + /* We accept &COND_EXPR as soon as both operands are addressable and + expect the outcome to be the address of the selected operand. */ + return (addressable_p (TREE_OPERAND (gnu_expr, 1), NULL_TREE) + && addressable_p (TREE_OPERAND (gnu_expr, 2), NULL_TREE)); + + case COMPONENT_REF: + return (((!DECL_BIT_FIELD (TREE_OPERAND (gnu_expr, 1)) + /* Even with DECL_BIT_FIELD cleared, we have to ensure that + the field is sufficiently aligned, in case it is subject + to a pragma Component_Alignment. But we don't need to + check the alignment of the containing record, as it is + guaranteed to be not smaller than that of its most + aligned field that is not a bit-field. */ + && (!STRICT_ALIGNMENT + || DECL_ALIGN (TREE_OPERAND (gnu_expr, 1)) + >= TYPE_ALIGN (TREE_TYPE (gnu_expr)))) + /* The field of a padding record is always addressable. */ + || TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (gnu_expr, 0)))) + && addressable_p (TREE_OPERAND (gnu_expr, 0), NULL_TREE)); + + case ARRAY_REF: case ARRAY_RANGE_REF: + case REALPART_EXPR: case IMAGPART_EXPR: + case NOP_EXPR: + return addressable_p (TREE_OPERAND (gnu_expr, 0), NULL_TREE); + + case CONVERT_EXPR: + return (AGGREGATE_TYPE_P (TREE_TYPE (gnu_expr)) + && addressable_p (TREE_OPERAND (gnu_expr, 0), NULL_TREE)); + + case VIEW_CONVERT_EXPR: + { + /* This is addressable if we can avoid a copy. */ + tree type = TREE_TYPE (gnu_expr); + tree inner_type = TREE_TYPE (TREE_OPERAND (gnu_expr, 0)); + return (((TYPE_MODE (type) == TYPE_MODE (inner_type) + && (!STRICT_ALIGNMENT + || TYPE_ALIGN (type) <= TYPE_ALIGN (inner_type) + || TYPE_ALIGN (inner_type) >= BIGGEST_ALIGNMENT)) + || ((TYPE_MODE (type) == BLKmode + || TYPE_MODE (inner_type) == BLKmode) + && (!STRICT_ALIGNMENT + || TYPE_ALIGN (type) <= TYPE_ALIGN (inner_type) + || TYPE_ALIGN (inner_type) >= BIGGEST_ALIGNMENT + || TYPE_ALIGN_OK (type) + || TYPE_ALIGN_OK (inner_type)))) + && addressable_p (TREE_OPERAND (gnu_expr, 0), NULL_TREE)); + } + + default: + return false; + } +} + +/* Do the processing for the declaration of a GNAT_ENTITY, a type. If + a separate Freeze node exists, delay the bulk of the processing. Otherwise + make a GCC type for GNAT_ENTITY and set up the correspondence. */ + +void +process_type (Entity_Id gnat_entity) +{ + tree gnu_old + = present_gnu_tree (gnat_entity) ? get_gnu_tree (gnat_entity) : 0; + tree gnu_new; + + /* If we are to delay elaboration of this type, just do any + elaborations needed for expressions within the declaration and + make a dummy type entry for this node and its Full_View (if + any) in case something points to it. Don't do this if it + has already been done (the only way that can happen is if + the private completion is also delayed). */ + if (Present (Freeze_Node (gnat_entity)) + || (IN (Ekind (gnat_entity), Incomplete_Or_Private_Kind) + && Present (Full_View (gnat_entity)) + && Freeze_Node (Full_View (gnat_entity)) + && !present_gnu_tree (Full_View (gnat_entity)))) + { + elaborate_entity (gnat_entity); + + if (!gnu_old) + { + tree gnu_decl = TYPE_STUB_DECL (make_dummy_type (gnat_entity)); + save_gnu_tree (gnat_entity, gnu_decl, false); + if (IN (Ekind (gnat_entity), Incomplete_Or_Private_Kind) + && Present (Full_View (gnat_entity))) + { + if (Has_Completion_In_Body (gnat_entity)) + DECL_TAFT_TYPE_P (gnu_decl) = 1; + save_gnu_tree (Full_View (gnat_entity), gnu_decl, false); + } + } + + return; + } + + /* If we saved away a dummy type for this node it means that this + made the type that corresponds to the full type of an incomplete + type. Clear that type for now and then update the type in the + pointers. */ + if (gnu_old) + { + gcc_assert (TREE_CODE (gnu_old) == TYPE_DECL + && TYPE_IS_DUMMY_P (TREE_TYPE (gnu_old))); + + save_gnu_tree (gnat_entity, NULL_TREE, false); + } + + /* Now fully elaborate the type. */ + gnu_new = gnat_to_gnu_entity (gnat_entity, NULL_TREE, 1); + gcc_assert (TREE_CODE (gnu_new) == TYPE_DECL); + + /* If we have an old type and we've made pointers to this type, update those + pointers. If this is a Taft amendment type in the main unit, we need to + mark the type as used since other units referencing it don't see the full + declaration and, therefore, cannot mark it as used themselves. */ + if (gnu_old) + { + update_pointer_to (TYPE_MAIN_VARIANT (TREE_TYPE (gnu_old)), + TREE_TYPE (gnu_new)); + if (DECL_TAFT_TYPE_P (gnu_old)) + used_types_insert (TREE_TYPE (gnu_new)); + } + + /* If this is a record type corresponding to a task or protected type + that is a completion of an incomplete type, perform a similar update + on the type. ??? Including protected types here is a guess. */ + if (IN (Ekind (gnat_entity), Record_Kind) + && Is_Concurrent_Record_Type (gnat_entity) + && present_gnu_tree (Corresponding_Concurrent_Type (gnat_entity))) + { + tree gnu_task_old + = get_gnu_tree (Corresponding_Concurrent_Type (gnat_entity)); + + save_gnu_tree (Corresponding_Concurrent_Type (gnat_entity), + NULL_TREE, false); + save_gnu_tree (Corresponding_Concurrent_Type (gnat_entity), + gnu_new, false); + + update_pointer_to (TYPE_MAIN_VARIANT (TREE_TYPE (gnu_task_old)), + TREE_TYPE (gnu_new)); + } +} + +/* GNAT_ENTITY is the type of the resulting constructor, GNAT_ASSOC is the + front of the Component_Associations of an N_Aggregate and GNU_TYPE is the + GCC type of the corresponding record type. Return the CONSTRUCTOR. */ + +static tree +assoc_to_constructor (Entity_Id gnat_entity, Node_Id gnat_assoc, tree gnu_type) +{ + tree gnu_list = NULL_TREE, gnu_result; + + /* We test for GNU_FIELD being empty in the case where a variant + was the last thing since we don't take things off GNAT_ASSOC in + that case. We check GNAT_ASSOC in case we have a variant, but it + has no fields. */ + + for (; Present (gnat_assoc); gnat_assoc = Next (gnat_assoc)) + { + Node_Id gnat_field = First (Choices (gnat_assoc)); + tree gnu_field = gnat_to_gnu_field_decl (Entity (gnat_field)); + tree gnu_expr = gnat_to_gnu (Expression (gnat_assoc)); + + /* The expander is supposed to put a single component selector name + in every record component association. */ + gcc_assert (No (Next (gnat_field))); + + /* Ignore fields that have Corresponding_Discriminants since we'll + be setting that field in the parent. */ + if (Present (Corresponding_Discriminant (Entity (gnat_field))) + && Is_Tagged_Type (Scope (Entity (gnat_field)))) + continue; + + /* Also ignore discriminants of Unchecked_Unions. */ + if (Is_Unchecked_Union (gnat_entity) + && Ekind (Entity (gnat_field)) == E_Discriminant) + continue; + + /* Before assigning a value in an aggregate make sure range checks + are done if required. Then convert to the type of the field. */ + if (Do_Range_Check (Expression (gnat_assoc))) + gnu_expr = emit_range_check (gnu_expr, Etype (gnat_field), Empty); + + gnu_expr = convert (TREE_TYPE (gnu_field), gnu_expr); + + /* Add the field and expression to the list. */ + gnu_list = tree_cons (gnu_field, gnu_expr, gnu_list); + } + + gnu_result = extract_values (gnu_list, gnu_type); + +#ifdef ENABLE_CHECKING + /* Verify that every entry in GNU_LIST was used. */ + for (; gnu_list; gnu_list = TREE_CHAIN (gnu_list)) + gcc_assert (TREE_ADDRESSABLE (gnu_list)); +#endif + + return gnu_result; +} + +/* Build a possibly nested constructor for array aggregates. GNAT_EXPR is + the first element of an array aggregate. It may itself be an aggregate. + GNU_ARRAY_TYPE is the GCC type corresponding to the array aggregate. + GNAT_COMPONENT_TYPE is the type of the array component; it is needed + for range checking. */ + +static tree +pos_to_constructor (Node_Id gnat_expr, tree gnu_array_type, + Entity_Id gnat_component_type) +{ + tree gnu_index = TYPE_MIN_VALUE (TYPE_DOMAIN (gnu_array_type)); + tree gnu_expr; + vec<constructor_elt, va_gc> *gnu_expr_vec = NULL; + + for ( ; Present (gnat_expr); gnat_expr = Next (gnat_expr)) + { + /* If the expression is itself an array aggregate then first build the + innermost constructor if it is part of our array (multi-dimensional + case). */ + if (Nkind (gnat_expr) == N_Aggregate + && TREE_CODE (TREE_TYPE (gnu_array_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_array_type))) + gnu_expr = pos_to_constructor (First (Expressions (gnat_expr)), + TREE_TYPE (gnu_array_type), + gnat_component_type); + else + { + gnu_expr = gnat_to_gnu (gnat_expr); + + /* Before assigning the element to the array, make sure it is + in range. */ + if (Do_Range_Check (gnat_expr)) + gnu_expr = emit_range_check (gnu_expr, gnat_component_type, Empty); + } + + CONSTRUCTOR_APPEND_ELT (gnu_expr_vec, gnu_index, + convert (TREE_TYPE (gnu_array_type), gnu_expr)); + + gnu_index = int_const_binop (PLUS_EXPR, gnu_index, integer_one_node); + } + + return gnat_build_constructor (gnu_array_type, gnu_expr_vec); +} + +/* Subroutine of assoc_to_constructor: VALUES is a list of field associations, + some of which are from RECORD_TYPE. Return a CONSTRUCTOR consisting + of the associations that are from RECORD_TYPE. If we see an internal + record, make a recursive call to fill it in as well. */ + +static tree +extract_values (tree values, tree record_type) +{ + tree field, tem; + vec<constructor_elt, va_gc> *v = NULL; + + for (field = TYPE_FIELDS (record_type); field; field = DECL_CHAIN (field)) + { + tree value = 0; + + /* _Parent is an internal field, but may have values in the aggregate, + so check for values first. */ + if ((tem = purpose_member (field, values))) + { + value = TREE_VALUE (tem); + TREE_ADDRESSABLE (tem) = 1; + } + + else if (DECL_INTERNAL_P (field)) + { + value = extract_values (values, TREE_TYPE (field)); + if (TREE_CODE (value) == CONSTRUCTOR + && vec_safe_is_empty (CONSTRUCTOR_ELTS (value))) + value = 0; + } + else + /* If we have a record subtype, the names will match, but not the + actual FIELD_DECLs. */ + for (tem = values; tem; tem = TREE_CHAIN (tem)) + if (DECL_NAME (TREE_PURPOSE (tem)) == DECL_NAME (field)) + { + value = convert (TREE_TYPE (field), TREE_VALUE (tem)); + TREE_ADDRESSABLE (tem) = 1; + } + + if (!value) + continue; + + CONSTRUCTOR_APPEND_ELT (v, field, value); + } + + return gnat_build_constructor (record_type, v); +} + +/* Process a N_Validate_Unchecked_Conversion node. */ + +static void +validate_unchecked_conversion (Node_Id gnat_node) +{ + tree gnu_source_type = gnat_to_gnu_type (Source_Type (gnat_node)); + tree gnu_target_type = gnat_to_gnu_type (Target_Type (gnat_node)); + + /* If the target is a pointer type, see if we are either converting from a + non-pointer or from a pointer to a type with a different alias set and + warn if so, unless the pointer has been marked to alias everything. */ + if (POINTER_TYPE_P (gnu_target_type) + && !TYPE_REF_CAN_ALIAS_ALL (gnu_target_type)) + { + tree gnu_source_desig_type = POINTER_TYPE_P (gnu_source_type) + ? TREE_TYPE (gnu_source_type) + : NULL_TREE; + tree gnu_target_desig_type = TREE_TYPE (gnu_target_type); + alias_set_type target_alias_set = get_alias_set (gnu_target_desig_type); + + if (target_alias_set != 0 + && (!POINTER_TYPE_P (gnu_source_type) + || !alias_sets_conflict_p (get_alias_set (gnu_source_desig_type), + target_alias_set))) + { + post_error_ne ("?possible aliasing problem for type&", + gnat_node, Target_Type (gnat_node)); + post_error ("\\?use -fno-strict-aliasing switch for references", + gnat_node); + post_error_ne ("\\?or use `pragma No_Strict_Aliasing (&);`", + gnat_node, Target_Type (gnat_node)); + } + } + + /* Likewise if the target is a fat pointer type, but we have no mechanism to + mitigate the problem in this case, so we unconditionally warn. */ + else if (TYPE_IS_FAT_POINTER_P (gnu_target_type)) + { + tree gnu_source_desig_type + = TYPE_IS_FAT_POINTER_P (gnu_source_type) + ? TREE_TYPE (TREE_TYPE (TYPE_FIELDS (gnu_source_type))) + : NULL_TREE; + tree gnu_target_desig_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (gnu_target_type))); + alias_set_type target_alias_set = get_alias_set (gnu_target_desig_type); + + if (target_alias_set != 0 + && (!TYPE_IS_FAT_POINTER_P (gnu_source_type) + || !alias_sets_conflict_p (get_alias_set (gnu_source_desig_type), + target_alias_set))) + { + post_error_ne ("?possible aliasing problem for type&", + gnat_node, Target_Type (gnat_node)); + post_error ("\\?use -fno-strict-aliasing switch for references", + gnat_node); + } + } +} + +/* EXP is to be treated as an array or record. Handle the cases when it is + an access object and perform the required dereferences. */ + +static tree +maybe_implicit_deref (tree exp) +{ + /* If the type is a pointer, dereference it. */ + if (POINTER_TYPE_P (TREE_TYPE (exp)) + || TYPE_IS_FAT_POINTER_P (TREE_TYPE (exp))) + exp = build_unary_op (INDIRECT_REF, NULL_TREE, exp); + + /* If we got a padded type, remove it too. */ + if (TYPE_IS_PADDING_P (TREE_TYPE (exp))) + exp = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (exp))), exp); + + return exp; +} + +/* Convert SLOC into LOCUS. Return true if SLOC corresponds to a source code + location and false if it doesn't. In the former case, set the Gigi global + variable REF_FILENAME to the simple debug file name as given by sinput. */ + +bool +Sloc_to_locus (Source_Ptr Sloc, location_t *locus) +{ + if (Sloc == No_Location) + return false; + + if (Sloc <= Standard_Location) + { + *locus = BUILTINS_LOCATION; + return false; + } + else + { + Source_File_Index file = Get_Source_File_Index (Sloc); + Logical_Line_Number line = Get_Logical_Line_Number (Sloc); + Column_Number column = Get_Column_Number (Sloc); + struct line_map *map = LINEMAPS_ORDINARY_MAP_AT (line_table, file - 1); + + /* We can have zero if pragma Source_Reference is in effect. */ + if (line < 1) + line = 1; + + /* Translate the location. */ + *locus = linemap_position_for_line_and_column (map, line, column); + } + + ref_filename + = IDENTIFIER_POINTER + (get_identifier + (Get_Name_String (Debug_Source_Name (Get_Source_File_Index (Sloc)))));; + + return true; +} + +/* Similar to set_expr_location, but start with the Sloc of GNAT_NODE and + don't do anything if it doesn't correspond to a source location. */ + +static void +set_expr_location_from_node (tree node, Node_Id gnat_node) +{ + location_t locus; + + if (!Sloc_to_locus (Sloc (gnat_node), &locus)) + return; + + SET_EXPR_LOCATION (node, locus); +} + +/* More elaborate version of set_expr_location_from_node to be used in more + general contexts, for example the result of the translation of a generic + GNAT node. */ + +static void +set_gnu_expr_location_from_node (tree node, Node_Id gnat_node) +{ + /* Set the location information on the node if it is a real expression. + References can be reused for multiple GNAT nodes and they would get + the location information of their last use. Also make sure not to + overwrite an existing location as it is probably more precise. */ + + switch (TREE_CODE (node)) + { + CASE_CONVERT: + case NON_LVALUE_EXPR: + break; + + case COMPOUND_EXPR: + if (EXPR_P (TREE_OPERAND (node, 1))) + set_gnu_expr_location_from_node (TREE_OPERAND (node, 1), gnat_node); + + /* ... fall through ... */ + + default: + if (!REFERENCE_CLASS_P (node) && !EXPR_HAS_LOCATION (node)) + { + set_expr_location_from_node (node, gnat_node); + set_end_locus_from_node (node, gnat_node); + } + break; + } +} + +/* Return a colon-separated list of encodings contained in encoded Ada + name. */ + +static const char * +extract_encoding (const char *name) +{ + char *encoding = (char *) ggc_alloc_atomic (strlen (name)); + get_encoding (name, encoding); + return encoding; +} + +/* Extract the Ada name from an encoded name. */ + +static const char * +decode_name (const char *name) +{ + char *decoded = (char *) ggc_alloc_atomic (strlen (name) * 2 + 60); + __gnat_decode (name, decoded, 0); + return decoded; +} + +/* Post an error message. MSG is the error message, properly annotated. + NODE is the node at which to post the error and the node to use for the + '&' substitution. */ + +void +post_error (const char *msg, Node_Id node) +{ + String_Template temp; + Fat_Pointer fp; + + temp.Low_Bound = 1, temp.High_Bound = strlen (msg); + fp.Array = msg, fp.Bounds = &temp; + if (Present (node)) + Error_Msg_N (fp, node); +} + +/* Similar to post_error, but NODE is the node at which to post the error and + ENT is the node to use for the '&' substitution. */ + +void +post_error_ne (const char *msg, Node_Id node, Entity_Id ent) +{ + String_Template temp; + Fat_Pointer fp; + + temp.Low_Bound = 1, temp.High_Bound = strlen (msg); + fp.Array = msg, fp.Bounds = &temp; + if (Present (node)) + Error_Msg_NE (fp, node, ent); +} + +/* Similar to post_error_ne, but NUM is the number to use for the '^'. */ + +void +post_error_ne_num (const char *msg, Node_Id node, Entity_Id ent, int num) +{ + Error_Msg_Uint_1 = UI_From_Int (num); + post_error_ne (msg, node, ent); +} + +/* Set the end_locus information for GNU_NODE, if any, from an explicit end + location associated with GNAT_NODE or GNAT_NODE itself, whichever makes + most sense. Return true if a sensible assignment was performed. */ + +static bool +set_end_locus_from_node (tree gnu_node, Node_Id gnat_node) +{ + Node_Id gnat_end_label = Empty; + location_t end_locus; + + /* Pick the GNAT node of which we'll take the sloc to assign to the GCC node + end_locus when there is one. We consider only GNAT nodes with a possible + End_Label attached. If the End_Label actually was unassigned, fallback + on the orginal node. We'd better assign an explicit sloc associated with + the outer construct in any case. */ + + switch (Nkind (gnat_node)) + { + case N_Package_Body: + case N_Subprogram_Body: + case N_Block_Statement: + gnat_end_label = End_Label (Handled_Statement_Sequence (gnat_node)); + break; + + case N_Package_Declaration: + gnat_end_label = End_Label (Specification (gnat_node)); + break; + + default: + return false; + } + + gnat_node = Present (gnat_end_label) ? gnat_end_label : gnat_node; + + /* Some expanded subprograms have neither an End_Label nor a Sloc + attached. Notify that to callers. */ + + if (!Sloc_to_locus (Sloc (gnat_node), &end_locus)) + return false; + + switch (TREE_CODE (gnu_node)) + { + case BIND_EXPR: + BLOCK_SOURCE_END_LOCATION (BIND_EXPR_BLOCK (gnu_node)) = end_locus; + return true; + + case FUNCTION_DECL: + DECL_STRUCT_FUNCTION (gnu_node)->function_end_locus = end_locus; + return true; + + default: + return false; + } +} + +/* Similar to post_error_ne, but T is a GCC tree representing the number to + write. If T represents a constant, the text inside curly brackets in + MSG will be output (presumably including a '^'). Otherwise it will not + be output and the text inside square brackets will be output instead. */ + +void +post_error_ne_tree (const char *msg, Node_Id node, Entity_Id ent, tree t) +{ + char *new_msg = XALLOCAVEC (char, strlen (msg) + 1); + char start_yes, end_yes, start_no, end_no; + const char *p; + char *q; + + if (TREE_CODE (t) == INTEGER_CST) + { + Error_Msg_Uint_1 = UI_From_gnu (t); + start_yes = '{', end_yes = '}', start_no = '[', end_no = ']'; + } + else + start_yes = '[', end_yes = ']', start_no = '{', end_no = '}'; + + for (p = msg, q = new_msg; *p; p++) + { + if (*p == start_yes) + for (p++; *p != end_yes; p++) + *q++ = *p; + else if (*p == start_no) + for (p++; *p != end_no; p++) + ; + else + *q++ = *p; + } + + *q = 0; + + post_error_ne (new_msg, node, ent); +} + +/* Similar to post_error_ne_tree, but NUM is a second integer to write. */ + +void +post_error_ne_tree_2 (const char *msg, Node_Id node, Entity_Id ent, tree t, + int num) +{ + Error_Msg_Uint_2 = UI_From_Int (num); + post_error_ne_tree (msg, node, ent, t); +} + +/* Initialize the table that maps GNAT codes to GCC codes for simple + binary and unary operations. */ + +static void +init_code_table (void) +{ + gnu_codes[N_And_Then] = TRUTH_ANDIF_EXPR; + gnu_codes[N_Or_Else] = TRUTH_ORIF_EXPR; + + gnu_codes[N_Op_And] = TRUTH_AND_EXPR; + gnu_codes[N_Op_Or] = TRUTH_OR_EXPR; + gnu_codes[N_Op_Xor] = TRUTH_XOR_EXPR; + gnu_codes[N_Op_Eq] = EQ_EXPR; + gnu_codes[N_Op_Ne] = NE_EXPR; + gnu_codes[N_Op_Lt] = LT_EXPR; + gnu_codes[N_Op_Le] = LE_EXPR; + gnu_codes[N_Op_Gt] = GT_EXPR; + gnu_codes[N_Op_Ge] = GE_EXPR; + gnu_codes[N_Op_Add] = PLUS_EXPR; + gnu_codes[N_Op_Subtract] = MINUS_EXPR; + gnu_codes[N_Op_Multiply] = MULT_EXPR; + gnu_codes[N_Op_Mod] = FLOOR_MOD_EXPR; + gnu_codes[N_Op_Rem] = TRUNC_MOD_EXPR; + gnu_codes[N_Op_Minus] = NEGATE_EXPR; + gnu_codes[N_Op_Abs] = ABS_EXPR; + gnu_codes[N_Op_Not] = TRUTH_NOT_EXPR; + gnu_codes[N_Op_Rotate_Left] = LROTATE_EXPR; + gnu_codes[N_Op_Rotate_Right] = RROTATE_EXPR; + gnu_codes[N_Op_Shift_Left] = LSHIFT_EXPR; + gnu_codes[N_Op_Shift_Right] = RSHIFT_EXPR; + gnu_codes[N_Op_Shift_Right_Arithmetic] = RSHIFT_EXPR; +} + +/* Return a label to branch to for the exception type in KIND or NULL_TREE + if none. */ + +tree +get_exception_label (char kind) +{ + if (kind == N_Raise_Constraint_Error) + return gnu_constraint_error_label_stack->last (); + else if (kind == N_Raise_Storage_Error) + return gnu_storage_error_label_stack->last (); + else if (kind == N_Raise_Program_Error) + return gnu_program_error_label_stack->last (); + else + return NULL_TREE; +} + +/* Return the decl for the current elaboration procedure. */ + +tree +get_elaboration_procedure (void) +{ + return gnu_elab_proc_stack->last (); +} + +#include "gt-ada-trans.h" |