/**************************************************************************** * * * GNAT COMPILER COMPONENTS * * * * T R A N S * * * * C Implementation File * * * * Copyright (C) 1992-2014, 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 * * . * * * * 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 "stringpool.h" #include "stor-layout.h" #include "stmt.h" #include "varasm.h" #include "flags.h" #include "output.h" #include "libfuncs.h" /* For set_stack_check_libfunc. */ #include "tree-iterator.h" #include "pointer-set.h" #include "gimple-expr.h" #include "gimplify.h" #include "bitmap.h" #include "cgraph.h" #include "diagnostic.h" #include "opts.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 /* 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; struct Flags *Flags_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 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_cache; bitmap named_ret_val; vec *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 *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 *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 *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 *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 stmt; tree loop_var; vec *checks; }; typedef struct loop_info_d *loop_info; /* Stack of loop_info structures associated with LOOP_STMT nodes. */ static GTY(()) vec *gnu_loop_stack; /* The stacks for N_{Push,Pop}_*_Label. */ static GTY(()) vec *gnu_constraint_error_label_stack; static GTY(()) vec *gnu_storage_error_label_stack; static GTY(()) vec *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 **, 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 void set_expr_location_from_node1 (tree, Node_Id, bool); static bool Sloc_to_locus1 (Source_Ptr, location_t *, bool); 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, struct Flags *flags_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; max_gnat_nodes = max_gnat_node; Nodes_Ptr = nodes_ptr; Flags_Ptr = flags_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); #if TARGET_ABI_OPEN_VMS vms_float_format = Float_Format; #endif 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); 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, 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, is_disabled, true, true, true, NULL, Empty); DECL_IGNORED_P (get_excptr_decl) = 1; set_exception_parameter_decl = create_subprog_decl (get_identifier ("__gnat_set_exception_parameter"), NULL_TREE, build_function_type_list (void_type_node, ptr_void_type_node, ptr_void_type_node, NULL_TREE), NULL_TREE, is_disabled, true, true, true, NULL, Empty); 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, is_disabled, 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 *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"), unsigned_char_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"), unsigned_char_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"), unsigned_char_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 (); /* Initialize the GCC support for FP operations. */ gnat_init_gcc_fp (); /* 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, is_disabled, 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); /* 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) { tree gnu_result = alloc_stmt_list (); unsigned char pragma_id; Node_Id gnat_temp; /* Do nothing if we are just annotating types and check for (and ignore) unrecognized pragmas. */ if (type_annotate_only || !Is_Pragma_Name (Chars (Pragma_Identifier (gnat_node)))) return gnu_result; pragma_id = Get_Pragma_Id (Chars (Pragma_Identifier (gnat_node))); switch (pragma_id) { 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_Loop_Optimize: for (gnat_temp = First (Pragma_Argument_Associations (gnat_node)); Present (gnat_temp); gnat_temp = Next (gnat_temp)) { tree gnu_loop_stmt = gnu_loop_stack ->last ()->stmt; switch (Chars (Expression (gnat_temp))) { case Name_No_Unroll: LOOP_STMT_NO_UNROLL (gnu_loop_stmt) = 1; break; case Name_Unroll: LOOP_STMT_UNROLL (gnu_loop_stmt) = 1; break; case Name_No_Vector: LOOP_STMT_NO_VECTOR (gnu_loop_stmt) = 1; break; case Name_Vector: LOOP_STMT_VECTOR (gnu_loop_stmt) = 1; break; default: gcc_unreachable (); } } 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; case Pragma_Warning_As_Error: case Pragma_Warnings: { Node_Id gnat_expr; /* Preserve the location of the pragma. */ const location_t location = input_location; struct cl_option_handlers handlers; unsigned int option_index; diagnostic_t kind; bool imply; gnat_temp = First (Pragma_Argument_Associations (gnat_node)); /* This is the String form: pragma Warning{s|_As_Error}(String). */ if (Nkind (Expression (gnat_temp)) == N_String_Literal) { switch (pragma_id) { case Pragma_Warning_As_Error: kind = DK_ERROR; imply = false; break; case Pragma_Warnings: kind = DK_WARNING; imply = true; break; default: gcc_unreachable (); } gnat_expr = Expression (gnat_temp); } /* This is the On/Off form: pragma Warnings (On | Off [,String]). */ else if (Nkind (Expression (gnat_temp)) == N_Identifier) { switch (Chars (Expression (gnat_temp))) { case Name_Off: kind = DK_IGNORED; break; case Name_On: kind = DK_WARNING; break; default: gcc_unreachable (); } if (Present (Next (gnat_temp))) { /* pragma Warnings (On | Off, Name) is handled differently. */ if (Nkind (Expression (Next (gnat_temp))) != N_String_Literal) break; gnat_expr = Expression (Next (gnat_temp)); } else gnat_expr = Empty; imply = false; } else gcc_unreachable (); /* This is the same implementation as in the C family of compilers. */ if (Present (gnat_expr)) { tree gnu_expr = gnat_to_gnu (gnat_expr); const char *opt_string = TREE_STRING_POINTER (gnu_expr); const int len = TREE_STRING_LENGTH (gnu_expr); if (len < 3 || opt_string[0] != '-' || opt_string[1] != 'W') break; for (option_index = 0; option_index < cl_options_count; option_index++) if (strcmp (cl_options[option_index].opt_text, opt_string) == 0) break; if (option_index == cl_options_count) { post_error ("unknown -W switch", gnat_node); break; } } else option_index = 0; set_default_handlers (&handlers); control_warning_option (option_index, (int) kind, imply, location, CL_Ada, &handlers, &global_options, &global_options_set, global_dc); } break; default: 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) { const Node_Id gnat_prefix = Prefix (gnat_node); 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 (gnat_prefix) == N_Identifier && Is_Subprogram (Entity (gnat_prefix)) && Is_Public (Entity (gnat_prefix)) && !present_gnu_tree (Entity (gnat_prefix))) gnu_prefix = get_minimal_subprog_decl (Entity (gnat_prefix)); else gnu_prefix = gnat_to_gnu (gnat_prefix); 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 *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 (gnat_prefix) == N_Identifier && is_cplusplus_method (Entity (gnat_prefix))) 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 (gnat_prefix) == N_Explicit_Dereference) { Node_Id gnat_actual_subtype = Actual_Designated_Subtype (gnat_prefix); tree gnu_ptr_type = TREE_TYPE (gnat_to_gnu (Prefix (gnat_prefix))); 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 { 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; bool unconstrained_ptr_deref = false; /* 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. We also note whether we are dereferencing a pointer to unconstrained array. */ if (!Is_Constrained (Etype (gnat_prefix))) switch (Nkind (gnat_prefix)) { case N_Identifier: /* This is the direct case. */ if (Ekind (Entity (gnat_prefix)) == E_In_Parameter) gnat_param = Entity (gnat_prefix); break; case N_Explicit_Dereference: /* 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 (Prefix (gnat_prefix)) == N_Identifier && Ekind (Entity (Prefix (gnat_prefix))) == E_In_Parameter) { if (Can_Never_Be_Null (Entity (Prefix (gnat_prefix)))) gnat_param = Entity (Prefix (gnat_prefix)); } else unconstrained_ptr_deref = true; break; default: break; } /* 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); switch (attribute) { case Attr_First: pa->first = gnu_result; break; case Attr_Last: pa->last = gnu_result; break; case Attr_Length: case Attr_Range_Length: pa->length = gnu_result; break; default: gcc_unreachable (); } } /* Otherwise, evaluate it each time it is referenced. */ else switch (attribute) { case Attr_First: case Attr_Last: /* If we are dereferencing a pointer to unconstrained array, we need to capture the value because the pointed-to bounds may subsequently be released. */ if (unconstrained_ptr_deref) gnu_result = build1 (SAVE_EXPR, TREE_TYPE (gnu_result), gnu_result); break; case Attr_Length: case Attr_Range_Length: /* Set the source location onto the predicate of the condition but not if the expression is cached to avoid messing up the debug info. */ if (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; default: gcc_unreachable (); } 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: { Entity_Id gnat_obj = Entity (gnat_prefix); int code; 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 (gnat_prefix)) 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; } } /* This construct doesn't define a scope so we shouldn't push a binding level around the statement list. Except that we have always done so historically and this makes it possible to reduce stack usage. As a compromise, we keep doing it for case statements, for which this has never been problematic, but not for case expressions in Ada 2012. */ if (choices_added_p) { const bool is_case_expression = (Nkind (Parent (gnat_node)) == N_Expression_With_Actions); tree group = build_stmt_group (Statements (gnat_when), !is_case_expression); 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; if (max) return tree_int_cst_lt (val, min_or_max_val) == 0; else return tree_int_cst_lt (min_or_max_val, val) == 0; } /* 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 statement for later reuse. */ gnu_loop_info->stmt = gnu_loop_stmt; /* 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; TREE_SIDE_EFFECTS (gnu_cond_expr) = 1; gnu_result = 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, is_disabled, 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 [ = ...] [...] RETURN_EXPR [ = R1] [...] return_type Ri; [...] RETURN_EXPR [ = ...] [...] RETURN_EXPR [ = 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 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 *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 *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->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 *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), 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 *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; gnu_return_var_stack->pop (); 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)); 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 *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) { /* If the original is a COND_EXPR whose first arm isn't meant to be further used, just deal with the second arm. This is very likely the conditional expression built for a check. */ if (TREE_CODE (gnu_orig) == COND_EXPR && TREE_CODE (TREE_OPERAND (gnu_orig, 1)) == COMPOUND_EXPR && integer_zerop (TREE_OPERAND (TREE_OPERAND (gnu_orig, 1), 1))) gnu_orig = TREE_OPERAND (gnu_orig, 2); 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); /* 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)) || (Is_Private_Type (Etype (gnat_actual)) && Is_Array_Type (Full_View (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); gnu_actual = build_unary_op (ADDR_EXPR, gnu_formal_type, gnu_actual); } /* Then see if the parameter is an array passed to a foreign convention subprogram. */ 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); } /* Then see if the parameter is passed by descriptor. */ 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)); } /* Otherwise the parameter is passed by copy. */ else { tree gnu_size; if (Ekind (gnat_formal) != E_In_Parameter) gnu_name_list = tree_cons (NULL_TREE, gnu_name, gnu_name_list); /* If we didn't create a PARM_DECL for the formal, this means that it is an Out parameter not passed by reference and that need not be copied in. In this case, the value of the actual need not be read. However, we still need to make sure that its side-effects are evaluated before the call, so we evaluate its address. */ if (!is_true_formal_parm) { if (TREE_SIDE_EFFECTS (gnu_name)) { tree addr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_name); append_to_statement_list (addr, &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; /* Node providing the sloc for the cleanup actions. */ Node_Id gnat_cleanup_loc_node = (Present (End_Label (gnat_node)) ? End_Label (gnat_node) : gnat_node); /* 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), gnat_cleanup_loc_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), gnat_cleanup_loc_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) ... else ". */ 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 unique 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 /* Clear column information so that the exception handler of an implicit transient block does not incorrectly inherit the slocs of a decision, which would otherwise confuse control flow based coverage analysis tools. */ set_expr_location_from_node1 (gnu_result, gnat_node, true); } 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_current_exc_ptr, 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)) { tree gnu_expr, gnu_etype; if (Nkind (gnat_temp) == N_Others_Choice) { 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); /* Declare and initialize the choice parameter, if present. */ if (Present (Choice_Parameter (gnat_node))) { tree gnu_param = gnat_to_gnu_entity (Choice_Parameter (gnat_node), NULL_TREE, 1); add_stmt (build_call_n_expr (set_exception_parameter_decl, 2, build_unary_op (ADDR_EXPR, NULL_TREE, gnu_param), gnu_incoming_exc_ptr)); } /* We don't have an End_Label at hand to set the location of the cleanup actions, so we use that of the exception handler itself instead. */ add_cleanup (build_call_n_expr (end_handler_decl, 1, gnu_incoming_exc_ptr), gnat_node); 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, is_disabled, 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_limited_with (); /* 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 *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, is_disabled, 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)) || (Is_Private_Type (Etype (gnat_node)) && 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)); gnu_result_type = get_unpadded_type (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))) : LOOP_STMT_LABEL (gnu_loop_stack->last ()->stmt))); 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_Limited_With (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_Limited_With (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 push a binding level around the statement list; but 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_Freeze_Generic_Entity: gnu_result = alloc_stmt_list (); 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 **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, but with column info cleared so that conditional branches generated as part of the cleanup code do not interfere with coverage analysis tools. */ static void add_cleanup (tree gnu_cleanup, Node_Id gnat_node) { if (Present (gnat_node)) set_expr_location_from_node1 (gnu_cleanup, gnat_node, true); 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)) && Present (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 *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 *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. If clear_column is true, set column information to 0. */ static bool Sloc_to_locus1 (Source_Ptr Sloc, location_t *locus, bool clear_column) { 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 = (clear_column ? 0 : 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 the above, not clearing the column information. */ bool Sloc_to_locus (Source_Ptr Sloc, location_t *locus) { return Sloc_to_locus1 (Sloc, locus, false); } /* 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_node1 (tree node, Node_Id gnat_node, bool clear_column) { location_t locus; if (!Sloc_to_locus1 (Sloc (gnat_node), &locus, clear_column)) return; SET_EXPR_LOCATION (node, locus); } /* Similar to the above, not clearing the column information. */ static void set_expr_location_from_node (tree node, Node_Id gnat_node) { set_expr_location_from_node1 (node, gnat_node, false); } /* 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; if (No (node)) return; temp.Low_Bound = 1; temp.High_Bound = strlen (msg); fp.Bounds = &temp; fp.Array = msg; 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; if (No (node)) return; temp.Low_Bound = 1; temp.High_Bound = strlen (msg); fp.Bounds = &temp; fp.Array = msg; 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 original 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. For a block statement with no End_Label, clear column information, so that the tree for a transient block does not receive the sloc of a source condition. */ if (!Sloc_to_locus1 (Sloc (gnat_node), &end_locus, No (gnat_end_label) && (Nkind (gnat_node) == N_Block_Statement))) 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"