Mercurial > hg > CbC > CbC_gcc
diff gcc/ada/gcc-interface/utils.c @ 111:04ced10e8804
gcc 7
| author | kono |
|---|---|
| date | Fri, 27 Oct 2017 22:46:09 +0900 |
| parents | |
| children | 84e7813d76e9 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gcc/ada/gcc-interface/utils.c Fri Oct 27 22:46:09 2017 +0900 @@ -0,0 +1,6458 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * U T I L S * + * * + * C Implementation File * + * * + * Copyright (C) 1992-2017, 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 along with GCC; see the file COPYING3. If not see * + * <http://www.gnu.org/licenses/>. * + * * + * GNAT was originally developed by the GNAT team at New York University. * + * Extensive contributions were provided by Ada Core Technologies Inc. * + * * + ****************************************************************************/ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "target.h" +#include "function.h" +#include "tree.h" +#include "stringpool.h" +#include "cgraph.h" +#include "diagnostic.h" +#include "alias.h" +#include "fold-const.h" +#include "stor-layout.h" +#include "attribs.h" +#include "varasm.h" +#include "toplev.h" +#include "output.h" +#include "debug.h" +#include "convert.h" +#include "common/common-target.h" +#include "langhooks.h" +#include "tree-dump.h" +#include "tree-inline.h" + +#include "ada.h" +#include "types.h" +#include "atree.h" +#include "nlists.h" +#include "uintp.h" +#include "fe.h" +#include "sinfo.h" +#include "einfo.h" +#include "ada-tree.h" +#include "gigi.h" + +/* If nonzero, pretend we are allocating at global level. */ +int force_global; + +/* The default alignment of "double" floating-point types, i.e. floating + point types whose size is equal to 64 bits, or 0 if this alignment is + not specifically capped. */ +int double_float_alignment; + +/* The default alignment of "double" or larger scalar types, i.e. scalar + types whose size is greater or equal to 64 bits, or 0 if this alignment + is not specifically capped. */ +int double_scalar_alignment; + +/* True if floating-point arithmetics may use wider intermediate results. */ +bool fp_arith_may_widen = true; + +/* Tree nodes for the various types and decls we create. */ +tree gnat_std_decls[(int) ADT_LAST]; + +/* Functions to call for each of the possible raise reasons. */ +tree gnat_raise_decls[(int) LAST_REASON_CODE + 1]; + +/* Likewise, but with extra info for each of the possible raise reasons. */ +tree gnat_raise_decls_ext[(int) LAST_REASON_CODE + 1]; + +/* Forward declarations for handlers of attributes. */ +static tree handle_const_attribute (tree *, tree, tree, int, bool *); +static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *); +static tree handle_pure_attribute (tree *, tree, tree, int, bool *); +static tree handle_novops_attribute (tree *, tree, tree, int, bool *); +static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *); +static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *); +static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *); +static tree handle_noinline_attribute (tree *, tree, tree, int, bool *); +static tree handle_noclone_attribute (tree *, tree, tree, int, bool *); +static tree handle_leaf_attribute (tree *, tree, tree, int, bool *); +static tree handle_always_inline_attribute (tree *, tree, tree, int, bool *); +static tree handle_malloc_attribute (tree *, tree, tree, int, bool *); +static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *); +static tree handle_vector_size_attribute (tree *, tree, tree, int, bool *); +static tree handle_vector_type_attribute (tree *, tree, tree, int, bool *); + +/* Fake handler for attributes we don't properly support, typically because + they'd require dragging a lot of the common-c front-end circuitry. */ +static tree fake_attribute_handler (tree *, tree, tree, int, bool *); + +/* Table of machine-independent internal attributes for Ada. We support + this minimal set of attributes to accommodate the needs of builtins. */ +const struct attribute_spec gnat_internal_attribute_table[] = +{ + /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler, + affects_type_identity } */ + { "const", 0, 0, true, false, false, handle_const_attribute, + false }, + { "nothrow", 0, 0, true, false, false, handle_nothrow_attribute, + false }, + { "pure", 0, 0, true, false, false, handle_pure_attribute, + false }, + { "no vops", 0, 0, true, false, false, handle_novops_attribute, + false }, + { "nonnull", 0, -1, false, true, true, handle_nonnull_attribute, + false }, + { "sentinel", 0, 1, false, true, true, handle_sentinel_attribute, + false }, + { "noreturn", 0, 0, true, false, false, handle_noreturn_attribute, + false }, + { "noinline", 0, 0, true, false, false, handle_noinline_attribute, + false }, + { "noclone", 0, 0, true, false, false, handle_noclone_attribute, + false }, + { "leaf", 0, 0, true, false, false, handle_leaf_attribute, + false }, + { "always_inline",0, 0, true, false, false, handle_always_inline_attribute, + false }, + { "malloc", 0, 0, true, false, false, handle_malloc_attribute, + false }, + { "type generic", 0, 0, false, true, true, handle_type_generic_attribute, + false }, + + { "vector_size", 1, 1, false, true, false, handle_vector_size_attribute, + false }, + { "vector_type", 0, 0, false, true, false, handle_vector_type_attribute, + false }, + { "may_alias", 0, 0, false, true, false, NULL, false }, + + /* ??? format and format_arg are heavy and not supported, which actually + prevents support for stdio builtins, which we however declare as part + of the common builtins.def contents. */ + { "format", 3, 3, false, true, true, fake_attribute_handler, false }, + { "format_arg", 1, 1, false, true, true, fake_attribute_handler, false }, + + { NULL, 0, 0, false, false, false, NULL, false } +}; + +/* Associates a GNAT tree node to a GCC tree node. It is used in + `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation + of `save_gnu_tree' for more info. */ +static GTY((length ("max_gnat_nodes"))) tree *associate_gnat_to_gnu; + +#define GET_GNU_TREE(GNAT_ENTITY) \ + associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] + +#define SET_GNU_TREE(GNAT_ENTITY,VAL) \ + associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL) + +#define PRESENT_GNU_TREE(GNAT_ENTITY) \ + (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE) + +/* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */ +static GTY((length ("max_gnat_nodes"))) tree *dummy_node_table; + +#define GET_DUMMY_NODE(GNAT_ENTITY) \ + dummy_node_table[(GNAT_ENTITY) - First_Node_Id] + +#define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \ + dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL) + +#define PRESENT_DUMMY_NODE(GNAT_ENTITY) \ + (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE) + +/* This variable keeps a table for types for each precision so that we only + allocate each of them once. Signed and unsigned types are kept separate. + + Note that these types are only used when fold-const requests something + special. Perhaps we should NOT share these types; we'll see how it + goes later. */ +static GTY(()) tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2]; + +/* Likewise for float types, but record these by mode. */ +static GTY(()) tree float_types[NUM_MACHINE_MODES]; + +/* For each binding contour we allocate a binding_level structure to indicate + the binding depth. */ + +struct GTY((chain_next ("%h.chain"))) gnat_binding_level { + /* The binding level containing this one (the enclosing binding level). */ + struct gnat_binding_level *chain; + /* The BLOCK node for this level. */ + tree block; + /* If nonzero, the setjmp buffer that needs to be updated for any + variable-sized definition within this context. */ + tree jmpbuf_decl; +}; + +/* The binding level currently in effect. */ +static GTY(()) struct gnat_binding_level *current_binding_level; + +/* A chain of gnat_binding_level structures awaiting reuse. */ +static GTY((deletable)) struct gnat_binding_level *free_binding_level; + +/* The context to be used for global declarations. */ +static GTY(()) tree global_context; + +/* An array of global declarations. */ +static GTY(()) vec<tree, va_gc> *global_decls; + +/* An array of builtin function declarations. */ +static GTY(()) vec<tree, va_gc> *builtin_decls; + +/* A chain of unused BLOCK nodes. */ +static GTY((deletable)) tree free_block_chain; + +/* A hash table of padded types. It is modelled on the generic type + hash table in tree.c, which must thus be used as a reference. */ + +struct GTY((for_user)) pad_type_hash +{ + hashval_t hash; + tree type; +}; + +struct pad_type_hasher : ggc_cache_ptr_hash<pad_type_hash> +{ + static inline hashval_t hash (pad_type_hash *t) { return t->hash; } + static bool equal (pad_type_hash *a, pad_type_hash *b); + + static int + keep_cache_entry (pad_type_hash *&t) + { + return ggc_marked_p (t->type); + } +}; + +static GTY ((cache)) hash_table<pad_type_hasher> *pad_type_hash_table; + +static tree merge_sizes (tree, tree, tree, bool, bool); +static tree fold_bit_position (const_tree); +static tree compute_related_constant (tree, tree); +static tree split_plus (tree, tree *); +static tree float_type_for_precision (int, machine_mode); +static tree convert_to_fat_pointer (tree, tree); +static unsigned int scale_by_factor_of (tree, unsigned int); +static bool potential_alignment_gap (tree, tree, tree); + +/* Linked list used as a queue to defer the initialization of the DECL_CONTEXT + of ..._DECL nodes and of the TYPE_CONTEXT of ..._TYPE nodes. */ +struct deferred_decl_context_node +{ + /* The ..._DECL node to work on. */ + tree decl; + + /* The corresponding entity's Scope. */ + Entity_Id gnat_scope; + + /* The value of force_global when DECL was pushed. */ + int force_global; + + /* The list of ..._TYPE nodes to propagate the context to. */ + vec<tree> types; + + /* The next queue item. */ + struct deferred_decl_context_node *next; +}; + +static struct deferred_decl_context_node *deferred_decl_context_queue = NULL; + +/* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to + feed it with the elaboration of GNAT_SCOPE. */ +static struct deferred_decl_context_node * +add_deferred_decl_context (tree decl, Entity_Id gnat_scope, int force_global); + +/* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to + feed it with the DECL_CONTEXT computed as part of N as soon as it is + computed. */ +static void add_deferred_type_context (struct deferred_decl_context_node *n, + tree type); + +/* Initialize data structures of the utils.c module. */ + +void +init_gnat_utils (void) +{ + /* Initialize the association of GNAT nodes to GCC trees. */ + associate_gnat_to_gnu = ggc_cleared_vec_alloc<tree> (max_gnat_nodes); + + /* Initialize the association of GNAT nodes to GCC trees as dummies. */ + dummy_node_table = ggc_cleared_vec_alloc<tree> (max_gnat_nodes); + + /* Initialize the hash table of padded types. */ + pad_type_hash_table = hash_table<pad_type_hasher>::create_ggc (512); +} + +/* Destroy data structures of the utils.c module. */ + +void +destroy_gnat_utils (void) +{ + /* Destroy the association of GNAT nodes to GCC trees. */ + ggc_free (associate_gnat_to_gnu); + associate_gnat_to_gnu = NULL; + + /* Destroy the association of GNAT nodes to GCC trees as dummies. */ + ggc_free (dummy_node_table); + dummy_node_table = NULL; + + /* Destroy the hash table of padded types. */ + pad_type_hash_table->empty (); + pad_type_hash_table = NULL; +} + +/* GNAT_ENTITY is a GNAT tree node for an entity. Associate GNU_DECL, a GCC + tree node, with GNAT_ENTITY. If GNU_DECL is not a ..._DECL node, abort. + If NO_CHECK is true, the latter check is suppressed. + + If GNU_DECL is zero, reset a previous association. */ + +void +save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl, bool no_check) +{ + /* Check that GNAT_ENTITY is not already defined and that it is being set + to something which is a decl. If that is not the case, this usually + means GNAT_ENTITY is defined twice, but occasionally is due to some + Gigi problem. */ + gcc_assert (!(gnu_decl + && (PRESENT_GNU_TREE (gnat_entity) + || (!no_check && !DECL_P (gnu_decl))))); + + SET_GNU_TREE (gnat_entity, gnu_decl); +} + +/* GNAT_ENTITY is a GNAT tree node for an entity. Return the GCC tree node + that was associated with it. If there is no such tree node, abort. + + In some cases, such as delayed elaboration or expressions that need to + be elaborated only once, GNAT_ENTITY is really not an entity. */ + +tree +get_gnu_tree (Entity_Id gnat_entity) +{ + gcc_assert (PRESENT_GNU_TREE (gnat_entity)); + return GET_GNU_TREE (gnat_entity); +} + +/* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */ + +bool +present_gnu_tree (Entity_Id gnat_entity) +{ + return PRESENT_GNU_TREE (gnat_entity); +} + +/* Make a dummy type corresponding to GNAT_TYPE. */ + +tree +make_dummy_type (Entity_Id gnat_type) +{ + Entity_Id gnat_equiv = Gigi_Equivalent_Type (Underlying_Type (gnat_type)); + tree gnu_type, debug_type; + + /* If there was no equivalent type (can only happen when just annotating + types) or underlying type, go back to the original type. */ + if (No (gnat_equiv)) + gnat_equiv = gnat_type; + + /* If it there already a dummy type, use that one. Else make one. */ + if (PRESENT_DUMMY_NODE (gnat_equiv)) + return GET_DUMMY_NODE (gnat_equiv); + + /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make + an ENUMERAL_TYPE. */ + gnu_type = make_node (Is_Record_Type (gnat_equiv) + ? tree_code_for_record_type (gnat_equiv) + : ENUMERAL_TYPE); + TYPE_NAME (gnu_type) = get_entity_name (gnat_type); + TYPE_DUMMY_P (gnu_type) = 1; + TYPE_STUB_DECL (gnu_type) + = create_type_stub_decl (TYPE_NAME (gnu_type), gnu_type); + if (Is_By_Reference_Type (gnat_equiv)) + TYPE_BY_REFERENCE_P (gnu_type) = 1; + + SET_DUMMY_NODE (gnat_equiv, gnu_type); + + /* Create a debug type so that debug info consumers only see an unspecified + type. */ + if (Needs_Debug_Info (gnat_type)) + { + debug_type = make_node (LANG_TYPE); + SET_TYPE_DEBUG_TYPE (gnu_type, debug_type); + + TYPE_NAME (debug_type) = TYPE_NAME (gnu_type); + TYPE_ARTIFICIAL (debug_type) = TYPE_ARTIFICIAL (gnu_type); + } + + return gnu_type; +} + +/* Return the dummy type that was made for GNAT_TYPE, if any. */ + +tree +get_dummy_type (Entity_Id gnat_type) +{ + return GET_DUMMY_NODE (gnat_type); +} + +/* Build dummy fat and thin pointer types whose designated type is specified + by GNAT_DESIG_TYPE/GNU_DESIG_TYPE and attach them to the latter. */ + +void +build_dummy_unc_pointer_types (Entity_Id gnat_desig_type, tree gnu_desig_type) +{ + tree gnu_template_type, gnu_ptr_template, gnu_array_type, gnu_ptr_array; + tree gnu_fat_type, fields, gnu_object_type; + + gnu_template_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_template_type) = create_concat_name (gnat_desig_type, "XUB"); + TYPE_DUMMY_P (gnu_template_type) = 1; + gnu_ptr_template = build_pointer_type (gnu_template_type); + + gnu_array_type = make_node (ENUMERAL_TYPE); + TYPE_NAME (gnu_array_type) = create_concat_name (gnat_desig_type, "XUA"); + TYPE_DUMMY_P (gnu_array_type) = 1; + gnu_ptr_array = build_pointer_type (gnu_array_type); + + gnu_fat_type = make_node (RECORD_TYPE); + /* Build a stub DECL to trigger the special processing for fat pointer types + in gnat_pushdecl. */ + TYPE_NAME (gnu_fat_type) + = create_type_stub_decl (create_concat_name (gnat_desig_type, "XUP"), + gnu_fat_type); + fields = create_field_decl (get_identifier ("P_ARRAY"), gnu_ptr_array, + gnu_fat_type, NULL_TREE, NULL_TREE, 0, 0); + DECL_CHAIN (fields) + = create_field_decl (get_identifier ("P_BOUNDS"), gnu_ptr_template, + gnu_fat_type, NULL_TREE, NULL_TREE, 0, 0); + finish_fat_pointer_type (gnu_fat_type, fields); + SET_TYPE_UNCONSTRAINED_ARRAY (gnu_fat_type, gnu_desig_type); + /* Suppress debug info until after the type is completed. */ + TYPE_DECL_SUPPRESS_DEBUG (TYPE_STUB_DECL (gnu_fat_type)) = 1; + + gnu_object_type = make_node (RECORD_TYPE); + TYPE_NAME (gnu_object_type) = create_concat_name (gnat_desig_type, "XUT"); + TYPE_DUMMY_P (gnu_object_type) = 1; + + TYPE_POINTER_TO (gnu_desig_type) = gnu_fat_type; + TYPE_REFERENCE_TO (gnu_desig_type) = gnu_fat_type; + TYPE_OBJECT_RECORD_TYPE (gnu_desig_type) = gnu_object_type; +} + +/* Return true if we are in the global binding level. */ + +bool +global_bindings_p (void) +{ + return force_global || !current_function_decl; +} + +/* Enter a new binding level. */ + +void +gnat_pushlevel (void) +{ + struct gnat_binding_level *newlevel = NULL; + + /* Reuse a struct for this binding level, if there is one. */ + if (free_binding_level) + { + newlevel = free_binding_level; + free_binding_level = free_binding_level->chain; + } + else + newlevel = ggc_alloc<gnat_binding_level> (); + + /* Use a free BLOCK, if any; otherwise, allocate one. */ + if (free_block_chain) + { + newlevel->block = free_block_chain; + free_block_chain = BLOCK_CHAIN (free_block_chain); + BLOCK_CHAIN (newlevel->block) = NULL_TREE; + } + else + newlevel->block = make_node (BLOCK); + + /* Point the BLOCK we just made to its parent. */ + if (current_binding_level) + BLOCK_SUPERCONTEXT (newlevel->block) = current_binding_level->block; + + BLOCK_VARS (newlevel->block) = NULL_TREE; + BLOCK_SUBBLOCKS (newlevel->block) = NULL_TREE; + TREE_USED (newlevel->block) = 1; + + /* Add this level to the front of the chain (stack) of active levels. */ + newlevel->chain = current_binding_level; + newlevel->jmpbuf_decl = NULL_TREE; + current_binding_level = newlevel; +} + +/* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL + and point FNDECL to this BLOCK. */ + +void +set_current_block_context (tree fndecl) +{ + BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl; + DECL_INITIAL (fndecl) = current_binding_level->block; + set_block_for_group (current_binding_level->block); +} + +/* Set the jmpbuf_decl for the current binding level to DECL. */ + +void +set_block_jmpbuf_decl (tree decl) +{ + current_binding_level->jmpbuf_decl = decl; +} + +/* Get the jmpbuf_decl, if any, for the current binding level. */ + +tree +get_block_jmpbuf_decl (void) +{ + return current_binding_level->jmpbuf_decl; +} + +/* Exit a binding level. Set any BLOCK into the current code group. */ + +void +gnat_poplevel (void) +{ + struct gnat_binding_level *level = current_binding_level; + tree block = level->block; + + BLOCK_VARS (block) = nreverse (BLOCK_VARS (block)); + BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block)); + + /* If this is a function-level BLOCK don't do anything. Otherwise, if there + are no variables free the block and merge its subblocks into those of its + parent block. Otherwise, add it to the list of its parent. */ + if (TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL) + ; + else if (!BLOCK_VARS (block)) + { + BLOCK_SUBBLOCKS (level->chain->block) + = block_chainon (BLOCK_SUBBLOCKS (block), + BLOCK_SUBBLOCKS (level->chain->block)); + BLOCK_CHAIN (block) = free_block_chain; + free_block_chain = block; + } + else + { + BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (level->chain->block); + BLOCK_SUBBLOCKS (level->chain->block) = block; + TREE_USED (block) = 1; + set_block_for_group (block); + } + + /* Free this binding structure. */ + current_binding_level = level->chain; + level->chain = free_binding_level; + free_binding_level = level; +} + +/* Exit a binding level and discard the associated BLOCK. */ + +void +gnat_zaplevel (void) +{ + struct gnat_binding_level *level = current_binding_level; + tree block = level->block; + + BLOCK_CHAIN (block) = free_block_chain; + free_block_chain = block; + + /* Free this binding structure. */ + current_binding_level = level->chain; + level->chain = free_binding_level; + free_binding_level = level; +} + +/* Set the context of TYPE and its parallel types (if any) to CONTEXT. */ + +static void +gnat_set_type_context (tree type, tree context) +{ + tree decl = TYPE_STUB_DECL (type); + + TYPE_CONTEXT (type) = context; + + while (decl && DECL_PARALLEL_TYPE (decl)) + { + tree parallel_type = DECL_PARALLEL_TYPE (decl); + + /* Give a context to the parallel types and their stub decl, if any. + Some parallel types seems to be present in multiple parallel type + chains, so don't mess with their context if they already have one. */ + if (!TYPE_CONTEXT (parallel_type)) + { + if (TYPE_STUB_DECL (parallel_type)) + DECL_CONTEXT (TYPE_STUB_DECL (parallel_type)) = context; + TYPE_CONTEXT (parallel_type) = context; + } + + decl = TYPE_STUB_DECL (DECL_PARALLEL_TYPE (decl)); + } +} + +/* Return the innermost scope, starting at GNAT_NODE, we are be interested in + the debug info, or Empty if there is no such scope. If not NULL, set + IS_SUBPROGRAM to whether the returned entity is a subprogram. */ + +Entity_Id +get_debug_scope (Node_Id gnat_node, bool *is_subprogram) +{ + Entity_Id gnat_entity; + + if (is_subprogram) + *is_subprogram = false; + + if (Nkind (gnat_node) == N_Defining_Identifier + || Nkind (gnat_node) == N_Defining_Operator_Symbol) + gnat_entity = Scope (gnat_node); + else + return Empty; + + while (Present (gnat_entity)) + { + switch (Ekind (gnat_entity)) + { + case E_Function: + case E_Procedure: + if (Present (Protected_Body_Subprogram (gnat_entity))) + gnat_entity = Protected_Body_Subprogram (gnat_entity); + + /* If the scope is a subprogram, then just rely on + current_function_decl, so that we don't have to defer + anything. This is needed because other places rely on the + validity of the DECL_CONTEXT attribute of FUNCTION_DECL nodes. */ + if (is_subprogram) + *is_subprogram = true; + return gnat_entity; + + case E_Record_Type: + case E_Record_Subtype: + return gnat_entity; + + default: + /* By default, we are not interested in this particular scope: go to + the outer one. */ + break; + } + + gnat_entity = Scope (gnat_entity); + } + + return Empty; +} + +/* If N is NULL, set TYPE's context to CONTEXT. Defer this to the processing + of N otherwise. */ + +static void +defer_or_set_type_context (tree type, tree context, + struct deferred_decl_context_node *n) +{ + if (n) + add_deferred_type_context (n, type); + else + gnat_set_type_context (type, context); +} + +/* Return global_context, but create it first if need be. */ + +static tree +get_global_context (void) +{ + if (!global_context) + { + global_context + = build_translation_unit_decl (get_identifier (main_input_filename)); + debug_hooks->register_main_translation_unit (global_context); + } + + return global_context; +} + +/* Record DECL as belonging to the current lexical scope and use GNAT_NODE + for location information and flag propagation. */ + +void +gnat_pushdecl (tree decl, Node_Id gnat_node) +{ + tree context = NULL_TREE; + struct deferred_decl_context_node *deferred_decl_context = NULL; + + /* If explicitely asked to make DECL global or if it's an imported nested + object, short-circuit the regular Scope-based context computation. */ + if (!((TREE_PUBLIC (decl) && DECL_EXTERNAL (decl)) || force_global == 1)) + { + /* Rely on the GNAT scope, or fallback to the current_function_decl if + the GNAT scope reached the global scope, if it reached a subprogram + or the declaration is a subprogram or a variable (for them we skip + intermediate context types because the subprogram body elaboration + machinery and the inliner both expect a subprogram context). + + Falling back to current_function_decl is necessary for implicit + subprograms created by gigi, such as the elaboration subprograms. */ + bool context_is_subprogram = false; + const Entity_Id gnat_scope + = get_debug_scope (gnat_node, &context_is_subprogram); + + if (Present (gnat_scope) + && !context_is_subprogram + && TREE_CODE (decl) != FUNCTION_DECL + && TREE_CODE (decl) != VAR_DECL) + /* Always assume the scope has not been elaborated, thus defer the + context propagation to the time its elaboration will be + available. */ + deferred_decl_context + = add_deferred_decl_context (decl, gnat_scope, force_global); + + /* External declarations (when force_global > 0) may not be in a + local context. */ + else if (current_function_decl && force_global == 0) + context = current_function_decl; + } + + /* If either we are forced to be in global mode or if both the GNAT scope and + the current_function_decl did not help in determining the context, use the + global scope. */ + if (!deferred_decl_context && !context) + context = get_global_context (); + + /* Functions imported in another function are not really nested. + For really nested functions mark them initially as needing + a static chain for uses of that flag before unnesting; + lower_nested_functions will then recompute it. */ + if (TREE_CODE (decl) == FUNCTION_DECL + && !TREE_PUBLIC (decl) + && context + && (TREE_CODE (context) == FUNCTION_DECL + || decl_function_context (context))) + DECL_STATIC_CHAIN (decl) = 1; + + if (!deferred_decl_context) + DECL_CONTEXT (decl) = context; + + TREE_NO_WARNING (decl) = (No (gnat_node) || Warnings_Off (gnat_node)); + + /* Set the location of DECL and emit a declaration for it. */ + if (Present (gnat_node) && !renaming_from_instantiation_p (gnat_node)) + Sloc_to_locus (Sloc (gnat_node), &DECL_SOURCE_LOCATION (decl)); + + add_decl_expr (decl, gnat_node); + + /* Put the declaration on the list. The list of declarations is in reverse + order. The list will be reversed later. Put global declarations in the + globals list and local ones in the current block. But skip TYPE_DECLs + for UNCONSTRAINED_ARRAY_TYPE in both cases, as they will cause trouble + with the debugger and aren't needed anyway. */ + if (!(TREE_CODE (decl) == TYPE_DECL + && TREE_CODE (TREE_TYPE (decl)) == UNCONSTRAINED_ARRAY_TYPE)) + { + /* External declarations must go to the binding level they belong to. + This will make corresponding imported entities are available in the + debugger at the proper time. */ + if (DECL_EXTERNAL (decl) + && TREE_CODE (decl) == FUNCTION_DECL + && DECL_BUILT_IN (decl)) + vec_safe_push (builtin_decls, decl); + else if (global_bindings_p ()) + vec_safe_push (global_decls, decl); + else + { + DECL_CHAIN (decl) = BLOCK_VARS (current_binding_level->block); + BLOCK_VARS (current_binding_level->block) = decl; + } + } + + /* For the declaration of a type, set its name either if it isn't already + set or if the previous type name was not derived from a source name. + We'd rather have the type named with a real name and all the pointer + types to the same object have the same node, except when the names are + both derived from source names. */ + if (TREE_CODE (decl) == TYPE_DECL && DECL_NAME (decl)) + { + tree t = TREE_TYPE (decl); + + /* Array and pointer types aren't tagged types in the C sense so we need + to generate a typedef in DWARF for them and make sure it is preserved, + unless the type is artificial. */ + if (!(TYPE_NAME (t) && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL) + && ((TREE_CODE (t) != ARRAY_TYPE && TREE_CODE (t) != POINTER_TYPE) + || DECL_ARTIFICIAL (decl))) + ; + /* For array and pointer types, create the DECL_ORIGINAL_TYPE that will + generate the typedef in DWARF. Also do that for fat pointer types + because, even though they are tagged types in the C sense, they are + still XUP types attached to the base array type at this point. */ + else if (!DECL_ARTIFICIAL (decl) + && (TREE_CODE (t) == ARRAY_TYPE + || TREE_CODE (t) == POINTER_TYPE + || TYPE_IS_FAT_POINTER_P (t))) + { + tree tt = build_variant_type_copy (t); + TYPE_NAME (tt) = decl; + defer_or_set_type_context (tt, + DECL_CONTEXT (decl), + deferred_decl_context); + TREE_TYPE (decl) = tt; + if (TYPE_NAME (t) + && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL + && DECL_ORIGINAL_TYPE (TYPE_NAME (t))) + DECL_ORIGINAL_TYPE (decl) = DECL_ORIGINAL_TYPE (TYPE_NAME (t)); + else + DECL_ORIGINAL_TYPE (decl) = t; + /* Array types need to have a name so that they can be related to + their GNAT encodings. */ + if (TREE_CODE (t) == ARRAY_TYPE && !TYPE_NAME (t)) + TYPE_NAME (t) = DECL_NAME (decl); + t = NULL_TREE; + } + else if (TYPE_NAME (t) + && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL + && DECL_ARTIFICIAL (TYPE_NAME (t)) && !DECL_ARTIFICIAL (decl)) + ; + else + t = NULL_TREE; + + /* Propagate the name to all the variants, this is needed for the type + qualifiers machinery to work properly (see check_qualified_type). + Also propagate the context to them. Note that it will be propagated + to all parallel types too thanks to gnat_set_type_context. */ + if (t) + for (t = TYPE_MAIN_VARIANT (t); t; t = TYPE_NEXT_VARIANT (t)) + /* ??? Because of the previous kludge, we can have variants of fat + pointer types with different names. */ + if (!(TYPE_IS_FAT_POINTER_P (t) + && TYPE_NAME (t) + && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL)) + { + TYPE_NAME (t) = decl; + defer_or_set_type_context (t, + DECL_CONTEXT (decl), + deferred_decl_context); + } + } +} + +/* Create a record type that contains a SIZE bytes long field of TYPE with a + starting bit position so that it is aligned to ALIGN bits, and leaving at + least ROOM bytes free before the field. BASE_ALIGN is the alignment the + record is guaranteed to get. GNAT_NODE is used for the position of the + associated TYPE_DECL. */ + +tree +make_aligning_type (tree type, unsigned int align, tree size, + unsigned int base_align, int room, Node_Id gnat_node) +{ + /* We will be crafting a record type with one field at a position set to be + the next multiple of ALIGN past record'address + room bytes. We use a + record placeholder to express record'address. */ + tree record_type = make_node (RECORD_TYPE); + tree record = build0 (PLACEHOLDER_EXPR, record_type); + + tree record_addr_st + = convert (sizetype, build_unary_op (ADDR_EXPR, NULL_TREE, record)); + + /* The diagram below summarizes the shape of what we manipulate: + + <--------- pos ----------> + { +------------+-------------+-----------------+ + record =>{ |############| ... | field (type) | + { +------------+-------------+-----------------+ + |<-- room -->|<- voffset ->|<---- size ----->| + o o + | | + record_addr vblock_addr + + Every length is in sizetype bytes there, except "pos" which has to be + set as a bit position in the GCC tree for the record. */ + tree room_st = size_int (room); + tree vblock_addr_st = size_binop (PLUS_EXPR, record_addr_st, room_st); + tree voffset_st, pos, field; + + tree name = TYPE_IDENTIFIER (type); + + name = concat_name (name, "ALIGN"); + TYPE_NAME (record_type) = name; + + /* Compute VOFFSET and then POS. The next byte position multiple of some + alignment after some address is obtained by "and"ing the alignment minus + 1 with the two's complement of the address. */ + voffset_st = size_binop (BIT_AND_EXPR, + fold_build1 (NEGATE_EXPR, sizetype, vblock_addr_st), + size_int ((align / BITS_PER_UNIT) - 1)); + + /* POS = (ROOM + VOFFSET) * BIT_PER_UNIT, in bitsizetype. */ + pos = size_binop (MULT_EXPR, + convert (bitsizetype, + size_binop (PLUS_EXPR, room_st, voffset_st)), + bitsize_unit_node); + + /* Craft the GCC record representation. We exceptionally do everything + manually here because 1) our generic circuitry is not quite ready to + handle the complex position/size expressions we are setting up, 2) we + have a strong simplifying factor at hand: we know the maximum possible + value of voffset, and 3) we have to set/reset at least the sizes in + accordance with this maximum value anyway, as we need them to convey + what should be "alloc"ated for this type. + + Use -1 as the 'addressable' indication for the field to prevent the + creation of a bitfield. We don't need one, it would have damaging + consequences on the alignment computation, and create_field_decl would + make one without this special argument, for instance because of the + complex position expression. */ + field = create_field_decl (get_identifier ("F"), type, record_type, size, + pos, 1, -1); + TYPE_FIELDS (record_type) = field; + + SET_TYPE_ALIGN (record_type, base_align); + TYPE_USER_ALIGN (record_type) = 1; + + TYPE_SIZE (record_type) + = size_binop (PLUS_EXPR, + size_binop (MULT_EXPR, convert (bitsizetype, size), + bitsize_unit_node), + bitsize_int (align + room * BITS_PER_UNIT)); + TYPE_SIZE_UNIT (record_type) + = size_binop (PLUS_EXPR, size, + size_int (room + align / BITS_PER_UNIT)); + + SET_TYPE_MODE (record_type, BLKmode); + relate_alias_sets (record_type, type, ALIAS_SET_COPY); + + /* Declare it now since it will never be declared otherwise. This is + necessary to ensure that its subtrees are properly marked. */ + create_type_decl (name, record_type, true, false, gnat_node); + + return record_type; +} + +/* TYPE is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE that is being used + as the field type of a packed record if IN_RECORD is true, or as the + component type of a packed array if IN_RECORD is false. See if we can + rewrite it either as a type that has non-BLKmode, which we can pack + tighter in the packed record case, or as a smaller type with at most + MAX_ALIGN alignment if the value is non-zero. If so, return the new + type; if not, return the original type. */ + +tree +make_packable_type (tree type, bool in_record, unsigned int max_align) +{ + unsigned HOST_WIDE_INT size = tree_to_uhwi (TYPE_SIZE (type)); + unsigned HOST_WIDE_INT new_size; + unsigned int align = TYPE_ALIGN (type); + unsigned int new_align; + + /* No point in doing anything if the size is zero. */ + if (size == 0) + return type; + + tree new_type = make_node (TREE_CODE (type)); + + /* Copy the name and flags from the old type to that of the new. + Note that we rely on the pointer equality created here for + TYPE_NAME to look through conversions in various places. */ + TYPE_NAME (new_type) = TYPE_NAME (type); + TYPE_JUSTIFIED_MODULAR_P (new_type) = TYPE_JUSTIFIED_MODULAR_P (type); + TYPE_CONTAINS_TEMPLATE_P (new_type) = TYPE_CONTAINS_TEMPLATE_P (type); + TYPE_REVERSE_STORAGE_ORDER (new_type) = TYPE_REVERSE_STORAGE_ORDER (type); + if (TREE_CODE (type) == RECORD_TYPE) + TYPE_PADDING_P (new_type) = TYPE_PADDING_P (type); + + /* If we are in a record and have a small size, set the alignment to + try for an integral mode. Otherwise set it to try for a smaller + type with BLKmode. */ + if (in_record && size <= MAX_FIXED_MODE_SIZE) + { + new_size = ceil_pow2 (size); + new_align = MIN (new_size, BIGGEST_ALIGNMENT); + SET_TYPE_ALIGN (new_type, new_align); + } + else + { + /* Do not try to shrink the size if the RM size is not constant. */ + if (TYPE_CONTAINS_TEMPLATE_P (type) + || !tree_fits_uhwi_p (TYPE_ADA_SIZE (type))) + return type; + + /* Round the RM size up to a unit boundary to get the minimal size + for a BLKmode record. Give up if it's already the size and we + don't need to lower the alignment. */ + new_size = tree_to_uhwi (TYPE_ADA_SIZE (type)); + new_size = (new_size + BITS_PER_UNIT - 1) & -BITS_PER_UNIT; + if (new_size == size && (max_align == 0 || align <= max_align)) + return type; + + new_align = MIN (new_size & -new_size, BIGGEST_ALIGNMENT); + if (max_align > 0 && new_align > max_align) + new_align = max_align; + SET_TYPE_ALIGN (new_type, MIN (align, new_align)); + } + + TYPE_USER_ALIGN (new_type) = 1; + + /* Now copy the fields, keeping the position and size as we don't want + to change the layout by propagating the packedness downwards. */ + tree new_field_list = NULL_TREE; + for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) + { + tree new_field_type = TREE_TYPE (field); + tree new_field, new_size; + + if (RECORD_OR_UNION_TYPE_P (new_field_type) + && !TYPE_FAT_POINTER_P (new_field_type) + && tree_fits_uhwi_p (TYPE_SIZE (new_field_type))) + new_field_type = make_packable_type (new_field_type, true, max_align); + + /* However, for the last field in a not already packed record type + that is of an aggregate type, we need to use the RM size in the + packable version of the record type, see finish_record_type. */ + if (!DECL_CHAIN (field) + && !TYPE_PACKED (type) + && RECORD_OR_UNION_TYPE_P (new_field_type) + && !TYPE_FAT_POINTER_P (new_field_type) + && !TYPE_CONTAINS_TEMPLATE_P (new_field_type) + && TYPE_ADA_SIZE (new_field_type)) + new_size = TYPE_ADA_SIZE (new_field_type); + else + new_size = DECL_SIZE (field); + + new_field + = create_field_decl (DECL_NAME (field), new_field_type, new_type, + new_size, bit_position (field), + TYPE_PACKED (type), + !DECL_NONADDRESSABLE_P (field)); + + DECL_INTERNAL_P (new_field) = DECL_INTERNAL_P (field); + SET_DECL_ORIGINAL_FIELD_TO_FIELD (new_field, field); + if (TREE_CODE (new_type) == QUAL_UNION_TYPE) + DECL_QUALIFIER (new_field) = DECL_QUALIFIER (field); + + DECL_CHAIN (new_field) = new_field_list; + new_field_list = new_field; + } + + finish_record_type (new_type, nreverse (new_field_list), 2, false); + relate_alias_sets (new_type, type, ALIAS_SET_COPY); + if (TYPE_STUB_DECL (type)) + SET_DECL_PARALLEL_TYPE (TYPE_STUB_DECL (new_type), + DECL_PARALLEL_TYPE (TYPE_STUB_DECL (type))); + + /* If this is a padding record, we never want to make the size smaller + than what was specified. For QUAL_UNION_TYPE, also copy the size. */ + if (TYPE_IS_PADDING_P (type) || TREE_CODE (type) == QUAL_UNION_TYPE) + { + TYPE_SIZE (new_type) = TYPE_SIZE (type); + TYPE_SIZE_UNIT (new_type) = TYPE_SIZE_UNIT (type); + new_size = size; + } + else + { + TYPE_SIZE (new_type) = bitsize_int (new_size); + TYPE_SIZE_UNIT (new_type) = size_int (new_size / BITS_PER_UNIT); + } + + if (!TYPE_CONTAINS_TEMPLATE_P (type)) + SET_TYPE_ADA_SIZE (new_type, TYPE_ADA_SIZE (type)); + + compute_record_mode (new_type); + + /* Try harder to get a packable type if necessary, for example + in case the record itself contains a BLKmode field. */ + if (in_record && TYPE_MODE (new_type) == BLKmode) + SET_TYPE_MODE (new_type, + mode_for_size_tree (TYPE_SIZE (new_type), + MODE_INT, 1).else_blk ()); + + /* If neither mode nor size nor alignment shrunk, return the old type. */ + if (TYPE_MODE (new_type) == BLKmode && new_size >= size && max_align == 0) + return type; + + return new_type; +} + +/* Return true if TYPE has an unsigned representation. This needs to be used + when the representation of types whose precision is not equal to their size + is manipulated based on the RM size. */ + +static inline bool +type_unsigned_for_rm (tree type) +{ + /* This is the common case. */ + if (TYPE_UNSIGNED (type)) + return true; + + /* See the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */ + if (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST + && tree_int_cst_sgn (TYPE_MIN_VALUE (type)) >= 0) + return true; + + return false; +} + +/* Given a type TYPE, return a new type whose size is appropriate for SIZE. + If TYPE is the best type, return it. Otherwise, make a new type. We + only support new integral and pointer types. FOR_BIASED is true if + we are making a biased type. */ + +tree +make_type_from_size (tree type, tree size_tree, bool for_biased) +{ + unsigned HOST_WIDE_INT size; + bool biased_p; + tree new_type; + + /* If size indicates an error, just return TYPE to avoid propagating + the error. Likewise if it's too large to represent. */ + if (!size_tree || !tree_fits_uhwi_p (size_tree)) + return type; + + size = tree_to_uhwi (size_tree); + + switch (TREE_CODE (type)) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + case BOOLEAN_TYPE: + biased_p = (TREE_CODE (type) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (type)); + + /* Integer types with precision 0 are forbidden. */ + if (size == 0) + size = 1; + + /* Only do something if the type isn't a packed array type and doesn't + already have the proper size and the size isn't too large. */ + if (TYPE_IS_PACKED_ARRAY_TYPE_P (type) + || (TYPE_PRECISION (type) == size && biased_p == for_biased) + || size > LONG_LONG_TYPE_SIZE) + break; + + biased_p |= for_biased; + + /* The type should be an unsigned type if the original type is unsigned + or if the lower bound is constant and non-negative or if the type is + biased, see E_Signed_Integer_Subtype case of gnat_to_gnu_entity. */ + if (type_unsigned_for_rm (type) || biased_p) + new_type = make_unsigned_type (size); + else + new_type = make_signed_type (size); + TREE_TYPE (new_type) = TREE_TYPE (type) ? TREE_TYPE (type) : type; + SET_TYPE_RM_MIN_VALUE (new_type, TYPE_MIN_VALUE (type)); + SET_TYPE_RM_MAX_VALUE (new_type, TYPE_MAX_VALUE (type)); + /* Copy the name to show that it's essentially the same type and + not a subrange type. */ + TYPE_NAME (new_type) = TYPE_NAME (type); + TYPE_BIASED_REPRESENTATION_P (new_type) = biased_p; + SET_TYPE_RM_SIZE (new_type, bitsize_int (size)); + return new_type; + + case RECORD_TYPE: + /* Do something if this is a fat pointer, in which case we + may need to return the thin pointer. */ + if (TYPE_FAT_POINTER_P (type) && size < POINTER_SIZE * 2) + { + scalar_int_mode p_mode; + if (!int_mode_for_size (size, 0).exists (&p_mode) + || !targetm.valid_pointer_mode (p_mode)) + p_mode = ptr_mode; + return + build_pointer_type_for_mode + (TYPE_OBJECT_RECORD_TYPE (TYPE_UNCONSTRAINED_ARRAY (type)), + p_mode, 0); + } + break; + + case POINTER_TYPE: + /* Only do something if this is a thin pointer, in which case we + may need to return the fat pointer. */ + if (TYPE_IS_THIN_POINTER_P (type) && size >= POINTER_SIZE * 2) + return + build_pointer_type (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))); + break; + + default: + break; + } + + return type; +} + +/* Return true iff the padded types are equivalent. */ + +bool +pad_type_hasher::equal (pad_type_hash *t1, pad_type_hash *t2) +{ + tree type1, type2; + + if (t1->hash != t2->hash) + return 0; + + type1 = t1->type; + type2 = t2->type; + + /* We consider that the padded types are equivalent if they pad the same type + and have the same size, alignment, RM size and storage order. Taking the + mode into account is redundant since it is determined by the others. */ + return + TREE_TYPE (TYPE_FIELDS (type1)) == TREE_TYPE (TYPE_FIELDS (type2)) + && TYPE_SIZE (type1) == TYPE_SIZE (type2) + && TYPE_ALIGN (type1) == TYPE_ALIGN (type2) + && TYPE_ADA_SIZE (type1) == TYPE_ADA_SIZE (type2) + && TYPE_REVERSE_STORAGE_ORDER (type1) == TYPE_REVERSE_STORAGE_ORDER (type2); +} + +/* Look up the padded TYPE in the hash table and return its canonical version + if it exists; otherwise, insert it into the hash table. */ + +static tree +lookup_and_insert_pad_type (tree type) +{ + hashval_t hashcode; + struct pad_type_hash in, *h; + + hashcode + = iterative_hash_object (TYPE_HASH (TREE_TYPE (TYPE_FIELDS (type))), 0); + hashcode = iterative_hash_expr (TYPE_SIZE (type), hashcode); + hashcode = iterative_hash_hashval_t (TYPE_ALIGN (type), hashcode); + hashcode = iterative_hash_expr (TYPE_ADA_SIZE (type), hashcode); + + in.hash = hashcode; + in.type = type; + h = pad_type_hash_table->find_with_hash (&in, hashcode); + if (h) + return h->type; + + h = ggc_alloc<pad_type_hash> (); + h->hash = hashcode; + h->type = type; + *pad_type_hash_table->find_slot_with_hash (h, hashcode, INSERT) = h; + return NULL_TREE; +} + +/* Ensure that TYPE has SIZE and ALIGN. Make and return a new padded type + if needed. We have already verified that SIZE and ALIGN are large enough. + GNAT_ENTITY is used to name the resulting record and to issue a warning. + IS_COMPONENT_TYPE is true if this is being done for the component type of + an array. IS_USER_TYPE is true if the original type needs to be completed. + DEFINITION is true if this type is being defined. SET_RM_SIZE is true if + the RM size of the resulting type is to be set to SIZE too; in this case, + the padded type is canonicalized before being returned. */ + +tree +maybe_pad_type (tree type, tree size, unsigned int align, + Entity_Id gnat_entity, bool is_component_type, + bool is_user_type, bool definition, bool set_rm_size) +{ + tree orig_size = TYPE_SIZE (type); + unsigned int orig_align = TYPE_ALIGN (type); + tree record, field; + + /* If TYPE is a padded type, see if it agrees with any size and alignment + we were given. If so, return the original type. Otherwise, strip + off the padding, since we will either be returning the inner type + or repadding it. If no size or alignment is specified, use that of + the original padded type. */ + if (TYPE_IS_PADDING_P (type)) + { + if ((!size + || operand_equal_p (round_up (size, orig_align), orig_size, 0)) + && (align == 0 || align == orig_align)) + return type; + + if (!size) + size = orig_size; + if (align == 0) + align = orig_align; + + type = TREE_TYPE (TYPE_FIELDS (type)); + orig_size = TYPE_SIZE (type); + orig_align = TYPE_ALIGN (type); + } + + /* If the size is either not being changed or is being made smaller (which + is not done here and is only valid for bitfields anyway), show the size + isn't changing. Likewise, clear the alignment if it isn't being + changed. Then return if we aren't doing anything. */ + if (size + && (operand_equal_p (size, orig_size, 0) + || (TREE_CODE (orig_size) == INTEGER_CST + && tree_int_cst_lt (size, orig_size)))) + size = NULL_TREE; + + if (align == orig_align) + align = 0; + + if (align == 0 && !size) + return type; + + /* If requested, complete the original type and give it a name. */ + if (is_user_type) + create_type_decl (get_entity_name (gnat_entity), type, + !Comes_From_Source (gnat_entity), + !(TYPE_NAME (type) + && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL + && DECL_IGNORED_P (TYPE_NAME (type))), + gnat_entity); + + /* We used to modify the record in place in some cases, but that could + generate incorrect debugging information. So make a new record + type and name. */ + record = make_node (RECORD_TYPE); + TYPE_PADDING_P (record) = 1; + + /* ??? Padding types around packed array implementation types will be + considered as root types in the array descriptor language hook (see + gnat_get_array_descr_info). Give them the original packed array type + name so that the one coming from sources appears in the debugging + information. */ + if (TYPE_IMPL_PACKED_ARRAY_P (type) + && TYPE_ORIGINAL_PACKED_ARRAY (type) + && gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL) + TYPE_NAME (record) = TYPE_NAME (TYPE_ORIGINAL_PACKED_ARRAY (type)); + else if (Present (gnat_entity)) + TYPE_NAME (record) = create_concat_name (gnat_entity, "PAD"); + + SET_TYPE_ALIGN (record, align ? align : orig_align); + TYPE_SIZE (record) = size ? size : orig_size; + TYPE_SIZE_UNIT (record) + = convert (sizetype, + size_binop (CEIL_DIV_EXPR, TYPE_SIZE (record), + bitsize_unit_node)); + + /* If we are changing the alignment and the input type is a record with + BLKmode and a small constant size, try to make a form that has an + integral mode. This might allow the padding record to also have an + integral mode, which will be much more efficient. There is no point + in doing so if a size is specified unless it is also a small constant + size and it is incorrect to do so if we cannot guarantee that the mode + will be naturally aligned since the field must always be addressable. + + ??? This might not always be a win when done for a stand-alone object: + since the nominal and the effective type of the object will now have + different modes, a VIEW_CONVERT_EXPR will be required for converting + between them and it might be hard to overcome afterwards, including + at the RTL level when the stand-alone object is accessed as a whole. */ + if (align != 0 + && RECORD_OR_UNION_TYPE_P (type) + && TYPE_MODE (type) == BLKmode + && !TYPE_BY_REFERENCE_P (type) + && TREE_CODE (orig_size) == INTEGER_CST + && !TREE_OVERFLOW (orig_size) + && compare_tree_int (orig_size, MAX_FIXED_MODE_SIZE) <= 0 + && (!size + || (TREE_CODE (size) == INTEGER_CST + && compare_tree_int (size, MAX_FIXED_MODE_SIZE) <= 0))) + { + tree packable_type = make_packable_type (type, true); + if (TYPE_MODE (packable_type) != BLKmode + && align >= TYPE_ALIGN (packable_type)) + type = packable_type; + } + + /* Now create the field with the original size. */ + field = create_field_decl (get_identifier ("F"), type, record, orig_size, + bitsize_zero_node, 0, 1); + DECL_INTERNAL_P (field) = 1; + + /* We will output additional debug info manually below. */ + finish_record_type (record, field, 1, false); + + if (gnat_encodings == DWARF_GNAT_ENCODINGS_MINIMAL) + SET_TYPE_DEBUG_TYPE (record, type); + + /* Set the RM size if requested. */ + if (set_rm_size) + { + tree canonical_pad_type; + + SET_TYPE_ADA_SIZE (record, size ? size : orig_size); + + /* If the padded type is complete and has constant size, we canonicalize + it by means of the hash table. This is consistent with the language + semantics and ensures that gigi and the middle-end have a common view + of these padded types. */ + if (TREE_CONSTANT (TYPE_SIZE (record)) + && (canonical_pad_type = lookup_and_insert_pad_type (record))) + { + record = canonical_pad_type; + goto built; + } + } + + /* Unless debugging information isn't being written for the input type, + write a record that shows what we are a subtype of and also make a + variable that indicates our size, if still variable. */ + if (TREE_CODE (orig_size) != INTEGER_CST + && TYPE_NAME (record) + && TYPE_NAME (type) + && !(TREE_CODE (TYPE_NAME (type)) == TYPE_DECL + && DECL_IGNORED_P (TYPE_NAME (type)))) + { + tree name = TYPE_IDENTIFIER (record); + tree size_unit = TYPE_SIZE_UNIT (record); + + /* A variable that holds the size is required even with no encoding since + it will be referenced by debugging information attributes. At global + level, we need a single variable across all translation units. */ + if (size + && TREE_CODE (size) != INTEGER_CST + && (definition || global_bindings_p ())) + { + /* Whether or not gnat_entity comes from source, this XVZ variable is + is a compilation artifact. */ + size_unit + = create_var_decl (concat_name (name, "XVZ"), NULL_TREE, sizetype, + size_unit, true, global_bindings_p (), + !definition && global_bindings_p (), false, + false, true, true, NULL, gnat_entity); + TYPE_SIZE_UNIT (record) = size_unit; + } + + /* There is no need to show what we are a subtype of when outputting as + few encodings as possible: regular debugging infomation makes this + redundant. */ + if (gnat_encodings != DWARF_GNAT_ENCODINGS_MINIMAL) + { + tree marker = make_node (RECORD_TYPE); + tree orig_name = TYPE_IDENTIFIER (type); + + TYPE_NAME (marker) = concat_name (name, "XVS"); + finish_record_type (marker, + create_field_decl (orig_name, + build_reference_type (type), + marker, NULL_TREE, NULL_TREE, + 0, 0), + 0, true); + TYPE_SIZE_UNIT (marker) = size_unit; + + add_parallel_type (record, marker); + } + } + +built: + /* If a simple size was explicitly given, maybe issue a warning. */ + if (!size + || TREE_CODE (size) == COND_EXPR + || TREE_CODE (size) == MAX_EXPR + || No (gnat_entity)) + return record; + + /* But don't do it if we are just annotating types and the type is tagged or + concurrent, since these types aren't fully laid out in this mode. */ + if (type_annotate_only) + { + Entity_Id gnat_type + = is_component_type + ? Component_Type (gnat_entity) : Etype (gnat_entity); + + if (Is_Tagged_Type (gnat_type) || Is_Concurrent_Type (gnat_type)) + return record; + } + + /* Take the original size as the maximum size of the input if there was an + unconstrained record involved and round it up to the specified alignment, + if one was specified, but only for aggregate types. */ + if (CONTAINS_PLACEHOLDER_P (orig_size)) + orig_size = max_size (orig_size, true); + + if (align && AGGREGATE_TYPE_P (type)) + orig_size = round_up (orig_size, align); + + if (!operand_equal_p (size, orig_size, 0) + && !(TREE_CODE (size) == INTEGER_CST + && TREE_CODE (orig_size) == INTEGER_CST + && (TREE_OVERFLOW (size) + || TREE_OVERFLOW (orig_size) + || tree_int_cst_lt (size, orig_size)))) + { + Node_Id gnat_error_node = Empty; + + /* For a packed array, post the message on the original array type. */ + if (Is_Packed_Array_Impl_Type (gnat_entity)) + gnat_entity = Original_Array_Type (gnat_entity); + + if ((Ekind (gnat_entity) == E_Component + || Ekind (gnat_entity) == E_Discriminant) + && Present (Component_Clause (gnat_entity))) + gnat_error_node = Last_Bit (Component_Clause (gnat_entity)); + else if (Present (Size_Clause (gnat_entity))) + gnat_error_node = Expression (Size_Clause (gnat_entity)); + + /* Generate message only for entities that come from source, since + if we have an entity created by expansion, the message will be + generated for some other corresponding source entity. */ + if (Comes_From_Source (gnat_entity)) + { + if (Present (gnat_error_node)) + post_error_ne_tree ("{^ }bits of & unused?", + gnat_error_node, gnat_entity, + size_diffop (size, orig_size)); + else if (is_component_type) + post_error_ne_tree ("component of& padded{ by ^ bits}?", + gnat_entity, gnat_entity, + size_diffop (size, orig_size)); + } + } + + return record; +} + +/* Return a copy of the padded TYPE but with reverse storage order. */ + +tree +set_reverse_storage_order_on_pad_type (tree type) +{ + tree field, canonical_pad_type; + + if (flag_checking) + { + /* If the inner type is not scalar then the function does nothing. */ + tree inner_type = TREE_TYPE (TYPE_FIELDS (type)); + gcc_assert (!AGGREGATE_TYPE_P (inner_type) + && !VECTOR_TYPE_P (inner_type)); + } + + /* This is required for the canonicalization. */ + gcc_assert (TREE_CONSTANT (TYPE_SIZE (type))); + + field = copy_node (TYPE_FIELDS (type)); + type = copy_type (type); + DECL_CONTEXT (field) = type; + TYPE_FIELDS (type) = field; + TYPE_REVERSE_STORAGE_ORDER (type) = 1; + canonical_pad_type = lookup_and_insert_pad_type (type); + return canonical_pad_type ? canonical_pad_type : type; +} + +/* Relate the alias sets of GNU_NEW_TYPE and GNU_OLD_TYPE according to OP. + If this is a multi-dimensional array type, do this recursively. + + OP may be + - ALIAS_SET_COPY: the new set is made a copy of the old one. + - ALIAS_SET_SUPERSET: the new set is made a superset of the old one. + - ALIAS_SET_SUBSET: the new set is made a subset of the old one. */ + +void +relate_alias_sets (tree gnu_new_type, tree gnu_old_type, enum alias_set_op op) +{ + /* Remove any padding from GNU_OLD_TYPE. It doesn't matter in the case + of a one-dimensional array, since the padding has the same alias set + as the field type, but if it's a multi-dimensional array, we need to + see the inner types. */ + while (TREE_CODE (gnu_old_type) == RECORD_TYPE + && (TYPE_JUSTIFIED_MODULAR_P (gnu_old_type) + || TYPE_PADDING_P (gnu_old_type))) + gnu_old_type = TREE_TYPE (TYPE_FIELDS (gnu_old_type)); + + /* Unconstrained array types are deemed incomplete and would thus be given + alias set 0. Retrieve the underlying array type. */ + if (TREE_CODE (gnu_old_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_old_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_old_type)))); + if (TREE_CODE (gnu_new_type) == UNCONSTRAINED_ARRAY_TYPE) + gnu_new_type + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (gnu_new_type)))); + + if (TREE_CODE (gnu_new_type) == ARRAY_TYPE + && TREE_CODE (TREE_TYPE (gnu_new_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (gnu_new_type))) + relate_alias_sets (TREE_TYPE (gnu_new_type), TREE_TYPE (gnu_old_type), op); + + switch (op) + { + case ALIAS_SET_COPY: + /* The alias set shouldn't be copied between array types with different + aliasing settings because this can break the aliasing relationship + between the array type and its element type. */ + if (flag_checking || flag_strict_aliasing) + gcc_assert (!(TREE_CODE (gnu_new_type) == ARRAY_TYPE + && TREE_CODE (gnu_old_type) == ARRAY_TYPE + && TYPE_NONALIASED_COMPONENT (gnu_new_type) + != TYPE_NONALIASED_COMPONENT (gnu_old_type))); + + TYPE_ALIAS_SET (gnu_new_type) = get_alias_set (gnu_old_type); + break; + + case ALIAS_SET_SUBSET: + case ALIAS_SET_SUPERSET: + { + alias_set_type old_set = get_alias_set (gnu_old_type); + alias_set_type new_set = get_alias_set (gnu_new_type); + + /* Do nothing if the alias sets conflict. This ensures that we + never call record_alias_subset several times for the same pair + or at all for alias set 0. */ + if (!alias_sets_conflict_p (old_set, new_set)) + { + if (op == ALIAS_SET_SUBSET) + record_alias_subset (old_set, new_set); + else + record_alias_subset (new_set, old_set); + } + } + break; + + default: + gcc_unreachable (); + } + + record_component_aliases (gnu_new_type); +} + +/* Record TYPE as a builtin type for Ada. NAME is the name of the type. + ARTIFICIAL_P is true if the type was generated by the compiler. */ + +void +record_builtin_type (const char *name, tree type, bool artificial_p) +{ + tree type_decl = build_decl (input_location, + TYPE_DECL, get_identifier (name), type); + DECL_ARTIFICIAL (type_decl) = artificial_p; + TYPE_ARTIFICIAL (type) = artificial_p; + gnat_pushdecl (type_decl, Empty); + + if (debug_hooks->type_decl) + debug_hooks->type_decl (type_decl, false); +} + +/* Finish constructing the character type CHAR_TYPE. + + In Ada character types are enumeration types and, as a consequence, are + represented in the front-end by integral types holding the positions of + the enumeration values as defined by the language, which means that the + integral types are unsigned. + + Unfortunately the signedness of 'char' in C is implementation-defined + and GCC even has the option -fsigned-char to toggle it at run time. + Since GNAT's philosophy is to be compatible with C by default, to wit + Interfaces.C.char is defined as a mere copy of Character, we may need + to declare character types as signed types in GENERIC and generate the + necessary adjustments to make them behave as unsigned types. + + The overall strategy is as follows: if 'char' is unsigned, do nothing; + if 'char' is signed, translate character types of CHAR_TYPE_SIZE and + character subtypes with RM_Size = Esize = CHAR_TYPE_SIZE into signed + types. The idea is to ensure that the bit pattern contained in the + Esize'd objects is not changed, even though the numerical value will + be interpreted differently depending on the signedness. */ + +void +finish_character_type (tree char_type) +{ + if (TYPE_UNSIGNED (char_type)) + return; + + /* Make a copy of a generic unsigned version since we'll modify it. */ + tree unsigned_char_type + = (char_type == char_type_node + ? unsigned_char_type_node + : copy_type (gnat_unsigned_type_for (char_type))); + + /* Create an unsigned version of the type and set it as debug type. */ + TYPE_NAME (unsigned_char_type) = TYPE_NAME (char_type); + TYPE_STRING_FLAG (unsigned_char_type) = TYPE_STRING_FLAG (char_type); + TYPE_ARTIFICIAL (unsigned_char_type) = TYPE_ARTIFICIAL (char_type); + SET_TYPE_DEBUG_TYPE (char_type, unsigned_char_type); + + /* If this is a subtype, make the debug type a subtype of the debug type + of the base type and convert literal RM bounds to unsigned. */ + if (TREE_TYPE (char_type)) + { + tree base_unsigned_char_type = TYPE_DEBUG_TYPE (TREE_TYPE (char_type)); + tree min_value = TYPE_RM_MIN_VALUE (char_type); + tree max_value = TYPE_RM_MAX_VALUE (char_type); + + if (TREE_CODE (min_value) == INTEGER_CST) + min_value = fold_convert (base_unsigned_char_type, min_value); + if (TREE_CODE (max_value) == INTEGER_CST) + max_value = fold_convert (base_unsigned_char_type, max_value); + + TREE_TYPE (unsigned_char_type) = base_unsigned_char_type; + SET_TYPE_RM_MIN_VALUE (unsigned_char_type, min_value); + SET_TYPE_RM_MAX_VALUE (unsigned_char_type, max_value); + } + + /* Adjust the RM bounds of the original type to unsigned; that's especially + important for types since they are implicit in this case. */ + SET_TYPE_RM_MIN_VALUE (char_type, TYPE_MIN_VALUE (unsigned_char_type)); + SET_TYPE_RM_MAX_VALUE (char_type, TYPE_MAX_VALUE (unsigned_char_type)); +} + +/* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST, + finish constructing the record type as a fat pointer type. */ + +void +finish_fat_pointer_type (tree record_type, tree field_list) +{ + /* Make sure we can put it into a register. */ + if (STRICT_ALIGNMENT) + SET_TYPE_ALIGN (record_type, MIN (BIGGEST_ALIGNMENT, 2 * POINTER_SIZE)); + + /* Show what it really is. */ + TYPE_FAT_POINTER_P (record_type) = 1; + + /* Do not emit debug info for it since the types of its fields may still be + incomplete at this point. */ + finish_record_type (record_type, field_list, 0, false); + + /* Force type_contains_placeholder_p to return true on it. Although the + PLACEHOLDER_EXPRs are referenced only indirectly, this isn't a pointer + type but the representation of the unconstrained array. */ + TYPE_CONTAINS_PLACEHOLDER_INTERNAL (record_type) = 2; +} + +/* Given a record type RECORD_TYPE and a list of FIELD_DECL nodes FIELD_LIST, + finish constructing the record or union type. If REP_LEVEL is zero, this + record has no representation clause and so will be entirely laid out here. + If REP_LEVEL is one, this record has a representation clause and has been + laid out already; only set the sizes and alignment. If REP_LEVEL is two, + this record is derived from a parent record and thus inherits its layout; + only make a pass on the fields to finalize them. DEBUG_INFO_P is true if + additional debug info needs to be output for this type. */ + +void +finish_record_type (tree record_type, tree field_list, int rep_level, + bool debug_info_p) +{ + enum tree_code code = TREE_CODE (record_type); + tree name = TYPE_IDENTIFIER (record_type); + tree ada_size = bitsize_zero_node; + tree size = bitsize_zero_node; + bool had_size = TYPE_SIZE (record_type) != 0; + bool had_size_unit = TYPE_SIZE_UNIT (record_type) != 0; + bool had_align = TYPE_ALIGN (record_type) != 0; + tree field; + + TYPE_FIELDS (record_type) = field_list; + + /* Always attach the TYPE_STUB_DECL for a record type. It is required to + generate debug info and have a parallel type. */ + TYPE_STUB_DECL (record_type) = create_type_stub_decl (name, record_type); + + /* Globally initialize the record first. If this is a rep'ed record, + that just means some initializations; otherwise, layout the record. */ + if (rep_level > 0) + { + SET_TYPE_ALIGN (record_type, MAX (BITS_PER_UNIT, + TYPE_ALIGN (record_type))); + + if (!had_size_unit) + TYPE_SIZE_UNIT (record_type) = size_zero_node; + + if (!had_size) + TYPE_SIZE (record_type) = bitsize_zero_node; + + /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE + out just like a UNION_TYPE, since the size will be fixed. */ + else if (code == QUAL_UNION_TYPE) + code = UNION_TYPE; + } + else + { + /* Ensure there isn't a size already set. There can be in an error + case where there is a rep clause but all fields have errors and + no longer have a position. */ + TYPE_SIZE (record_type) = 0; + + /* Ensure we use the traditional GCC layout for bitfields when we need + to pack the record type or have a representation clause. The other + possible layout (Microsoft C compiler), if available, would prevent + efficient packing in almost all cases. */ +#ifdef TARGET_MS_BITFIELD_LAYOUT + if (TARGET_MS_BITFIELD_LAYOUT && TYPE_PACKED (record_type)) + decl_attributes (&record_type, + tree_cons (get_identifier ("gcc_struct"), + NULL_TREE, NULL_TREE), + ATTR_FLAG_TYPE_IN_PLACE); +#endif + + layout_type (record_type); + } + + /* At this point, the position and size of each field is known. It was + either set before entry by a rep clause, or by laying out the type above. + + We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs) + to compute the Ada size; the GCC size and alignment (for rep'ed records + that are not padding types); and the mode (for rep'ed records). We also + clear the DECL_BIT_FIELD indication for the cases we know have not been + handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */ + + if (code == QUAL_UNION_TYPE) + field_list = nreverse (field_list); + + for (field = field_list; field; field = DECL_CHAIN (field)) + { + tree type = TREE_TYPE (field); + tree pos = bit_position (field); + tree this_size = DECL_SIZE (field); + tree this_ada_size; + + if (RECORD_OR_UNION_TYPE_P (type) + && !TYPE_FAT_POINTER_P (type) + && !TYPE_CONTAINS_TEMPLATE_P (type) + && TYPE_ADA_SIZE (type)) + this_ada_size = TYPE_ADA_SIZE (type); + else + this_ada_size = this_size; + + /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */ + if (DECL_BIT_FIELD (field) + && operand_equal_p (this_size, TYPE_SIZE (type), 0)) + { + unsigned int align = TYPE_ALIGN (type); + + /* In the general case, type alignment is required. */ + if (value_factor_p (pos, align)) + { + /* The enclosing record type must be sufficiently aligned. + Otherwise, if no alignment was specified for it and it + has been laid out already, bump its alignment to the + desired one if this is compatible with its size and + maximum alignment, if any. */ + if (TYPE_ALIGN (record_type) >= align) + { + SET_DECL_ALIGN (field, MAX (DECL_ALIGN (field), align)); + DECL_BIT_FIELD (field) = 0; + } + else if (!had_align + && rep_level == 0 + && value_factor_p (TYPE_SIZE (record_type), align) + && (!TYPE_MAX_ALIGN (record_type) + || TYPE_MAX_ALIGN (record_type) >= align)) + { + SET_TYPE_ALIGN (record_type, align); + SET_DECL_ALIGN (field, MAX (DECL_ALIGN (field), align)); + DECL_BIT_FIELD (field) = 0; + } + } + + /* In the non-strict alignment case, only byte alignment is. */ + if (!STRICT_ALIGNMENT + && DECL_BIT_FIELD (field) + && value_factor_p (pos, BITS_PER_UNIT)) + DECL_BIT_FIELD (field) = 0; + } + + /* If we still have DECL_BIT_FIELD set at this point, we know that the + field is technically not addressable. Except that it can actually + be addressed if it is BLKmode and happens to be properly aligned. */ + if (DECL_BIT_FIELD (field) + && !(DECL_MODE (field) == BLKmode + && value_factor_p (pos, BITS_PER_UNIT))) + DECL_NONADDRESSABLE_P (field) = 1; + + /* A type must be as aligned as its most aligned field that is not + a bit-field. But this is already enforced by layout_type. */ + if (rep_level > 0 && !DECL_BIT_FIELD (field)) + SET_TYPE_ALIGN (record_type, + MAX (TYPE_ALIGN (record_type), DECL_ALIGN (field))); + + switch (code) + { + case UNION_TYPE: + ada_size = size_binop (MAX_EXPR, ada_size, this_ada_size); + size = size_binop (MAX_EXPR, size, this_size); + break; + + case QUAL_UNION_TYPE: + ada_size + = fold_build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field), + this_ada_size, ada_size); + size = fold_build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field), + this_size, size); + break; + + case RECORD_TYPE: + /* Since we know here that all fields are sorted in order of + increasing bit position, the size of the record is one + higher than the ending bit of the last field processed + unless we have a rep clause, since in that case we might + have a field outside a QUAL_UNION_TYPE that has a higher ending + position. So use a MAX in that case. Also, if this field is a + QUAL_UNION_TYPE, we need to take into account the previous size in + the case of empty variants. */ + ada_size + = merge_sizes (ada_size, pos, this_ada_size, + TREE_CODE (type) == QUAL_UNION_TYPE, rep_level > 0); + size + = merge_sizes (size, pos, this_size, + TREE_CODE (type) == QUAL_UNION_TYPE, rep_level > 0); + break; + + default: + gcc_unreachable (); + } + } + + if (code == QUAL_UNION_TYPE) + nreverse (field_list); + + if (rep_level < 2) + { + /* If this is a padding record, we never want to make the size smaller + than what was specified in it, if any. */ + if (TYPE_IS_PADDING_P (record_type) && TYPE_SIZE (record_type)) + size = TYPE_SIZE (record_type); + + /* Now set any of the values we've just computed that apply. */ + if (!TYPE_FAT_POINTER_P (record_type) + && !TYPE_CONTAINS_TEMPLATE_P (record_type)) + SET_TYPE_ADA_SIZE (record_type, ada_size); + + if (rep_level > 0) + { + tree size_unit = had_size_unit + ? TYPE_SIZE_UNIT (record_type) + : convert (sizetype, + size_binop (CEIL_DIV_EXPR, size, + bitsize_unit_node)); + unsigned int align = TYPE_ALIGN (record_type); + + TYPE_SIZE (record_type) = variable_size (round_up (size, align)); + TYPE_SIZE_UNIT (record_type) + = variable_size (round_up (size_unit, align / BITS_PER_UNIT)); + + compute_record_mode (record_type); + } + } + + /* Reset the TYPE_MAX_ALIGN field since it's private to gigi. */ + TYPE_MAX_ALIGN (record_type) = 0; + + if (debug_info_p) + rest_of_record_type_compilation (record_type); +} + +/* Append PARALLEL_TYPE on the chain of parallel types of TYPE. If + PARRALEL_TYPE has no context and its computation is not deferred yet, also + propagate TYPE's context to PARALLEL_TYPE's or defer its propagation to the + moment TYPE will get a context. */ + +void +add_parallel_type (tree type, tree parallel_type) +{ + tree decl = TYPE_STUB_DECL (type); + + while (DECL_PARALLEL_TYPE (decl)) + decl = TYPE_STUB_DECL (DECL_PARALLEL_TYPE (decl)); + + SET_DECL_PARALLEL_TYPE (decl, parallel_type); + + /* If PARALLEL_TYPE already has a context, we are done. */ + if (TYPE_CONTEXT (parallel_type)) + return; + + /* Otherwise, try to get one from TYPE's context. If so, simply propagate + it to PARALLEL_TYPE. */ + if (TYPE_CONTEXT (type)) + gnat_set_type_context (parallel_type, TYPE_CONTEXT (type)); + + /* Otherwise TYPE has not context yet. We know it will have one thanks to + gnat_pushdecl and then its context will be propagated to PARALLEL_TYPE, + so we have nothing to do in this case. */ +} + +/* Return true if TYPE has a parallel type. */ + +static bool +has_parallel_type (tree type) +{ + tree decl = TYPE_STUB_DECL (type); + + return DECL_PARALLEL_TYPE (decl) != NULL_TREE; +} + +/* Wrap up compilation of RECORD_TYPE, i.e. output additional debug info + associated with it. It need not be invoked directly in most cases as + finish_record_type takes care of doing so. */ + +void +rest_of_record_type_compilation (tree record_type) +{ + bool var_size = false; + tree field; + + /* If this is a padded type, the bulk of the debug info has already been + generated for the field's type. */ + if (TYPE_IS_PADDING_P (record_type)) + return; + + /* If the type already has a parallel type (XVS type), then we're done. */ + if (has_parallel_type (record_type)) + return; + + for (field = TYPE_FIELDS (record_type); field; field = DECL_CHAIN (field)) + { + /* We need to make an XVE/XVU record if any field has variable size, + whether or not the record does. For example, if we have a union, + it may be that all fields, rounded up to the alignment, have the + same size, in which case we'll use that size. But the debug + output routines (except Dwarf2) won't be able to output the fields, + so we need to make the special record. */ + if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST + /* If a field has a non-constant qualifier, the record will have + variable size too. */ + || (TREE_CODE (record_type) == QUAL_UNION_TYPE + && TREE_CODE (DECL_QUALIFIER (field)) != INTEGER_CST)) + { + var_size = true; + break; + } + } + + /* If this record type is of variable size, make a parallel record type that + will tell the debugger how the former is laid out (see exp_dbug.ads). */ + if (var_size && gnat_encodings != DWARF_GNAT_ENCODINGS_MINIMAL) + { + tree new_record_type + = make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE + ? UNION_TYPE : TREE_CODE (record_type)); + tree orig_name = TYPE_IDENTIFIER (record_type), new_name; + tree last_pos = bitsize_zero_node; + tree old_field, prev_old_field = NULL_TREE; + + new_name + = concat_name (orig_name, TREE_CODE (record_type) == QUAL_UNION_TYPE + ? "XVU" : "XVE"); + TYPE_NAME (new_record_type) = new_name; + SET_TYPE_ALIGN (new_record_type, BIGGEST_ALIGNMENT); + TYPE_STUB_DECL (new_record_type) + = create_type_stub_decl (new_name, new_record_type); + DECL_IGNORED_P (TYPE_STUB_DECL (new_record_type)) + = DECL_IGNORED_P (TYPE_STUB_DECL (record_type)); + gnat_pushdecl (TYPE_STUB_DECL (new_record_type), Empty); + TYPE_SIZE (new_record_type) = size_int (TYPE_ALIGN (record_type)); + TYPE_SIZE_UNIT (new_record_type) + = size_int (TYPE_ALIGN (record_type) / BITS_PER_UNIT); + + /* Now scan all the fields, replacing each field with a new field + corresponding to the new encoding. */ + for (old_field = TYPE_FIELDS (record_type); old_field; + old_field = DECL_CHAIN (old_field)) + { + tree field_type = TREE_TYPE (old_field); + tree field_name = DECL_NAME (old_field); + tree curpos = fold_bit_position (old_field); + tree pos, new_field; + bool var = false; + unsigned int align = 0; + + /* See how the position was modified from the last position. + + There are two basic cases we support: a value was added + to the last position or the last position was rounded to + a boundary and they something was added. Check for the + first case first. If not, see if there is any evidence + of rounding. If so, round the last position and retry. + + If this is a union, the position can be taken as zero. */ + if (TREE_CODE (new_record_type) == UNION_TYPE) + pos = bitsize_zero_node; + else + pos = compute_related_constant (curpos, last_pos); + + if (!pos + && TREE_CODE (curpos) == MULT_EXPR + && tree_fits_uhwi_p (TREE_OPERAND (curpos, 1))) + { + tree offset = TREE_OPERAND (curpos, 0); + align = tree_to_uhwi (TREE_OPERAND (curpos, 1)); + align = scale_by_factor_of (offset, align); + last_pos = round_up (last_pos, align); + pos = compute_related_constant (curpos, last_pos); + } + else if (!pos + && TREE_CODE (curpos) == PLUS_EXPR + && tree_fits_uhwi_p (TREE_OPERAND (curpos, 1)) + && TREE_CODE (TREE_OPERAND (curpos, 0)) == MULT_EXPR + && tree_fits_uhwi_p + (TREE_OPERAND (TREE_OPERAND (curpos, 0), 1))) + { + tree offset = TREE_OPERAND (TREE_OPERAND (curpos, 0), 0); + unsigned HOST_WIDE_INT addend + = tree_to_uhwi (TREE_OPERAND (curpos, 1)); + align + = tree_to_uhwi (TREE_OPERAND (TREE_OPERAND (curpos, 0), 1)); + align = scale_by_factor_of (offset, align); + align = MIN (align, addend & -addend); + last_pos = round_up (last_pos, align); + pos = compute_related_constant (curpos, last_pos); + } + else if (potential_alignment_gap (prev_old_field, old_field, pos)) + { + align = TYPE_ALIGN (field_type); + last_pos = round_up (last_pos, align); + pos = compute_related_constant (curpos, last_pos); + } + + /* If we can't compute a position, set it to zero. + + ??? We really should abort here, but it's too much work + to get this correct for all cases. */ + if (!pos) + pos = bitsize_zero_node; + + /* See if this type is variable-sized and make a pointer type + and indicate the indirection if so. Beware that the debug + back-end may adjust the position computed above according + to the alignment of the field type, i.e. the pointer type + in this case, if we don't preventively counter that. */ + if (TREE_CODE (DECL_SIZE (old_field)) != INTEGER_CST) + { + field_type = build_pointer_type (field_type); + if (align != 0 && TYPE_ALIGN (field_type) > align) + { + field_type = copy_type (field_type); + SET_TYPE_ALIGN (field_type, align); + } + var = true; + } + + /* Make a new field name, if necessary. */ + if (var || align != 0) + { + char suffix[16]; + + if (align != 0) + sprintf (suffix, "XV%c%u", var ? 'L' : 'A', + align / BITS_PER_UNIT); + else + strcpy (suffix, "XVL"); + + field_name = concat_name (field_name, suffix); + } + + new_field + = create_field_decl (field_name, field_type, new_record_type, + DECL_SIZE (old_field), pos, 0, 0); + DECL_CHAIN (new_field) = TYPE_FIELDS (new_record_type); + TYPE_FIELDS (new_record_type) = new_field; + + /* If old_field is a QUAL_UNION_TYPE, take its size as being + zero. The only time it's not the last field of the record + is when there are other components at fixed positions after + it (meaning there was a rep clause for every field) and we + want to be able to encode them. */ + last_pos = size_binop (PLUS_EXPR, curpos, + (TREE_CODE (TREE_TYPE (old_field)) + == QUAL_UNION_TYPE) + ? bitsize_zero_node + : DECL_SIZE (old_field)); + prev_old_field = old_field; + } + + TYPE_FIELDS (new_record_type) = nreverse (TYPE_FIELDS (new_record_type)); + + add_parallel_type (record_type, new_record_type); + } +} + +/* Utility function of above to merge LAST_SIZE, the previous size of a record + with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this + represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and + replace a value of zero with the old size. If HAS_REP is true, we take the + MAX of the end position of this field with LAST_SIZE. In all other cases, + we use FIRST_BIT plus SIZE. Return an expression for the size. */ + +static tree +merge_sizes (tree last_size, tree first_bit, tree size, bool special, + bool has_rep) +{ + tree type = TREE_TYPE (last_size); + tree new_size; + + if (!special || TREE_CODE (size) != COND_EXPR) + { + new_size = size_binop (PLUS_EXPR, first_bit, size); + if (has_rep) + new_size = size_binop (MAX_EXPR, last_size, new_size); + } + + else + new_size = fold_build3 (COND_EXPR, type, TREE_OPERAND (size, 0), + integer_zerop (TREE_OPERAND (size, 1)) + ? last_size : merge_sizes (last_size, first_bit, + TREE_OPERAND (size, 1), + 1, has_rep), + integer_zerop (TREE_OPERAND (size, 2)) + ? last_size : merge_sizes (last_size, first_bit, + TREE_OPERAND (size, 2), + 1, has_rep)); + + /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially + when fed through substitute_in_expr) into thinking that a constant + size is not constant. */ + while (TREE_CODE (new_size) == NON_LVALUE_EXPR) + new_size = TREE_OPERAND (new_size, 0); + + return new_size; +} + +/* Return the bit position of FIELD, in bits from the start of the record, + and fold it as much as possible. This is a tree of type bitsizetype. */ + +static tree +fold_bit_position (const_tree field) +{ + tree offset = DECL_FIELD_OFFSET (field); + if (TREE_CODE (offset) == MULT_EXPR || TREE_CODE (offset) == PLUS_EXPR) + offset = size_binop (TREE_CODE (offset), + fold_convert (bitsizetype, TREE_OPERAND (offset, 0)), + fold_convert (bitsizetype, TREE_OPERAND (offset, 1))); + else + offset = fold_convert (bitsizetype, offset); + return size_binop (PLUS_EXPR, DECL_FIELD_BIT_OFFSET (field), + size_binop (MULT_EXPR, offset, bitsize_unit_node)); +} + +/* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are + related by the addition of a constant. Return that constant if so. */ + +static tree +compute_related_constant (tree op0, tree op1) +{ + tree factor, op0_var, op1_var, op0_cst, op1_cst, result; + + if (TREE_CODE (op0) == MULT_EXPR + && TREE_CODE (op1) == MULT_EXPR + && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST + && TREE_OPERAND (op1, 1) == TREE_OPERAND (op0, 1)) + { + factor = TREE_OPERAND (op0, 1); + op0 = TREE_OPERAND (op0, 0); + op1 = TREE_OPERAND (op1, 0); + } + else + factor = NULL_TREE; + + op0_cst = split_plus (op0, &op0_var); + op1_cst = split_plus (op1, &op1_var); + result = size_binop (MINUS_EXPR, op0_cst, op1_cst); + + if (operand_equal_p (op0_var, op1_var, 0)) + return factor ? size_binop (MULT_EXPR, factor, result) : result; + + return NULL_TREE; +} + +/* Utility function of above to split a tree OP which may be a sum, into a + constant part, which is returned, and a variable part, which is stored + in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of + bitsizetype. */ + +static tree +split_plus (tree in, tree *pvar) +{ + /* Strip conversions in order to ease the tree traversal and maximize the + potential for constant or plus/minus discovery. We need to be careful + to always return and set *pvar to bitsizetype trees, but it's worth + the effort. */ + in = remove_conversions (in, false); + + *pvar = convert (bitsizetype, in); + + if (TREE_CODE (in) == INTEGER_CST) + { + *pvar = bitsize_zero_node; + return convert (bitsizetype, in); + } + else if (TREE_CODE (in) == PLUS_EXPR || TREE_CODE (in) == MINUS_EXPR) + { + tree lhs_var, rhs_var; + tree lhs_con = split_plus (TREE_OPERAND (in, 0), &lhs_var); + tree rhs_con = split_plus (TREE_OPERAND (in, 1), &rhs_var); + + if (lhs_var == TREE_OPERAND (in, 0) + && rhs_var == TREE_OPERAND (in, 1)) + return bitsize_zero_node; + + *pvar = size_binop (TREE_CODE (in), lhs_var, rhs_var); + return size_binop (TREE_CODE (in), lhs_con, rhs_con); + } + else + return bitsize_zero_node; +} + +/* Return a copy of TYPE but safe to modify in any way. */ + +tree +copy_type (tree type) +{ + tree new_type = copy_node (type); + + /* Unshare the language-specific data. */ + if (TYPE_LANG_SPECIFIC (type)) + { + TYPE_LANG_SPECIFIC (new_type) = NULL; + SET_TYPE_LANG_SPECIFIC (new_type, GET_TYPE_LANG_SPECIFIC (type)); + } + + /* And the contents of the language-specific slot if needed. */ + if ((INTEGRAL_TYPE_P (type) || TREE_CODE (type) == REAL_TYPE) + && TYPE_RM_VALUES (type)) + { + TYPE_RM_VALUES (new_type) = NULL_TREE; + SET_TYPE_RM_SIZE (new_type, TYPE_RM_SIZE (type)); + SET_TYPE_RM_MIN_VALUE (new_type, TYPE_RM_MIN_VALUE (type)); + SET_TYPE_RM_MAX_VALUE (new_type, TYPE_RM_MAX_VALUE (type)); + } + + /* copy_node clears this field instead of copying it, because it is + aliased with TREE_CHAIN. */ + TYPE_STUB_DECL (new_type) = TYPE_STUB_DECL (type); + + TYPE_POINTER_TO (new_type) = NULL_TREE; + TYPE_REFERENCE_TO (new_type) = NULL_TREE; + TYPE_MAIN_VARIANT (new_type) = new_type; + TYPE_NEXT_VARIANT (new_type) = NULL_TREE; + TYPE_CANONICAL (new_type) = new_type; + + return new_type; +} + +/* Return a subtype of sizetype with range MIN to MAX and whose + TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position + of the associated TYPE_DECL. */ + +tree +create_index_type (tree min, tree max, tree index, Node_Id gnat_node) +{ + /* First build a type for the desired range. */ + tree type = build_nonshared_range_type (sizetype, min, max); + + /* Then set the index type. */ + SET_TYPE_INDEX_TYPE (type, index); + create_type_decl (NULL_TREE, type, true, false, gnat_node); + + return type; +} + +/* Return a subtype of TYPE with range MIN to MAX. If TYPE is NULL, + sizetype is used. */ + +tree +create_range_type (tree type, tree min, tree max) +{ + tree range_type; + + if (!type) + type = sizetype; + + /* First build a type with the base range. */ + range_type = build_nonshared_range_type (type, TYPE_MIN_VALUE (type), + TYPE_MAX_VALUE (type)); + + /* Then set the actual range. */ + SET_TYPE_RM_MIN_VALUE (range_type, min); + SET_TYPE_RM_MAX_VALUE (range_type, max); + + return range_type; +} + +/* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of TYPE. + NAME gives the name of the type to be used in the declaration. */ + +tree +create_type_stub_decl (tree name, tree type) +{ + tree type_decl = build_decl (input_location, TYPE_DECL, name, type); + DECL_ARTIFICIAL (type_decl) = 1; + TYPE_ARTIFICIAL (type) = 1; + return type_decl; +} + +/* Return a TYPE_DECL node for TYPE. NAME gives the name of the type to be + used in the declaration. ARTIFICIAL_P is true if the declaration was + generated by the compiler. DEBUG_INFO_P is true if we need to write + debug information about this type. GNAT_NODE is used for the position + of the decl. */ + +tree +create_type_decl (tree name, tree type, bool artificial_p, bool debug_info_p, + Node_Id gnat_node) +{ + enum tree_code code = TREE_CODE (type); + bool is_named + = TYPE_NAME (type) && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL; + tree type_decl; + + /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */ + gcc_assert (!TYPE_IS_DUMMY_P (type)); + + /* If the type hasn't been named yet, we're naming it; preserve an existing + TYPE_STUB_DECL that has been attached to it for some purpose. */ + if (!is_named && TYPE_STUB_DECL (type)) + { + type_decl = TYPE_STUB_DECL (type); + DECL_NAME (type_decl) = name; + } + else + type_decl = build_decl (input_location, TYPE_DECL, name, type); + + DECL_ARTIFICIAL (type_decl) = artificial_p; + TYPE_ARTIFICIAL (type) = artificial_p; + + /* Add this decl to the current binding level. */ + gnat_pushdecl (type_decl, gnat_node); + + /* If we're naming the type, equate the TYPE_STUB_DECL to the name. This + causes the name to be also viewed as a "tag" by the debug back-end, with + the advantage that no DW_TAG_typedef is emitted for artificial "tagged" + types in DWARF. + + Note that if "type" is used as a DECL_ORIGINAL_TYPE, it may be referenced + from multiple contexts, and "type_decl" references a copy of it: in such a + case, do not mess TYPE_STUB_DECL: we do not want to re-use the TYPE_DECL + with the mechanism above. */ + if (!is_named && type != DECL_ORIGINAL_TYPE (type_decl)) + TYPE_STUB_DECL (type) = type_decl; + + /* Do not generate debug info for UNCONSTRAINED_ARRAY_TYPE that the + back-end doesn't support, and for others if we don't need to. */ + if (code == UNCONSTRAINED_ARRAY_TYPE || !debug_info_p) + DECL_IGNORED_P (type_decl) = 1; + + return type_decl; +} + +/* Return a VAR_DECL or CONST_DECL node. + + NAME gives the name of the variable. ASM_NAME is its assembler name + (if provided). TYPE is its data type (a GCC ..._TYPE node). INIT is + the GCC tree for an optional initial expression; NULL_TREE if none. + + CONST_FLAG is true if this variable is constant, in which case we might + return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false. + + PUBLIC_FLAG is true if this is for a reference to a public entity or for a + definition to be made visible outside of the current compilation unit, for + instance variable definitions in a package specification. + + EXTERN_FLAG is true when processing an external variable declaration (as + opposed to a definition: no storage is to be allocated for the variable). + + STATIC_FLAG is only relevant when not at top level and indicates whether + to always allocate storage to the variable. + + VOLATILE_FLAG is true if this variable is declared as volatile. + + ARTIFICIAL_P is true if the variable was generated by the compiler. + + DEBUG_INFO_P is true if we need to write debug information for it. + + ATTR_LIST is the list of attributes to be attached to the variable. + + GNAT_NODE is used for the position of the decl. */ + +tree +create_var_decl (tree name, tree asm_name, tree type, tree init, + bool const_flag, bool public_flag, bool extern_flag, + bool static_flag, bool volatile_flag, bool artificial_p, + bool debug_info_p, struct attrib *attr_list, + Node_Id gnat_node, bool const_decl_allowed_p) +{ + /* Whether the object has static storage duration, either explicitly or by + virtue of being declared at the global level. */ + const bool static_storage = static_flag || global_bindings_p (); + + /* Whether the initializer is constant: for an external object or an object + with static storage duration, we check that the initializer is a valid + constant expression for initializing a static variable; otherwise, we + only check that it is constant. */ + const bool init_const + = (init + && gnat_types_compatible_p (type, TREE_TYPE (init)) + && (extern_flag || static_storage + ? initializer_constant_valid_p (init, TREE_TYPE (init)) + != NULL_TREE + : TREE_CONSTANT (init))); + + /* Whether we will make TREE_CONSTANT the DECL we produce here, in which + case the initializer may be used in lieu of the DECL node (as done in + Identifier_to_gnu). This is useful to prevent the need of elaboration + code when an identifier for which such a DECL is made is in turn used + as an initializer. We used to rely on CONST_DECL vs VAR_DECL for this, + but extra constraints apply to this choice (see below) and they are not + relevant to the distinction we wish to make. */ + const bool constant_p = const_flag && init_const; + + /* The actual DECL node. CONST_DECL was initially intended for enumerals + and may be used for scalars in general but not for aggregates. */ + tree var_decl + = build_decl (input_location, + (constant_p + && const_decl_allowed_p + && !AGGREGATE_TYPE_P (type) ? CONST_DECL : VAR_DECL), + name, type); + + /* Detect constants created by the front-end to hold 'reference to function + calls for stabilization purposes. This is needed for renaming. */ + if (const_flag && init && POINTER_TYPE_P (type)) + { + tree inner = init; + if (TREE_CODE (inner) == COMPOUND_EXPR) + inner = TREE_OPERAND (inner, 1); + inner = remove_conversions (inner, true); + if (TREE_CODE (inner) == ADDR_EXPR + && ((TREE_CODE (TREE_OPERAND (inner, 0)) == CALL_EXPR + && !call_is_atomic_load (TREE_OPERAND (inner, 0))) + || (TREE_CODE (TREE_OPERAND (inner, 0)) == VAR_DECL + && DECL_RETURN_VALUE_P (TREE_OPERAND (inner, 0))))) + DECL_RETURN_VALUE_P (var_decl) = 1; + } + + /* If this is external, throw away any initializations (they will be done + elsewhere) unless this is a constant for which we would like to remain + able to get the initializer. If we are defining a global here, leave a + constant initialization and save any variable elaborations for the + elaboration routine. If we are just annotating types, throw away the + initialization if it isn't a constant. */ + if ((extern_flag && !constant_p) + || (type_annotate_only && init && !TREE_CONSTANT (init))) + init = NULL_TREE; + + /* At the global level, a non-constant initializer generates elaboration + statements. Check that such statements are allowed, that is to say, + not violating a No_Elaboration_Code restriction. */ + if (init && !init_const && global_bindings_p ()) + Check_Elaboration_Code_Allowed (gnat_node); + + /* Attach the initializer, if any. */ + DECL_INITIAL (var_decl) = init; + + /* Directly set some flags. */ + DECL_ARTIFICIAL (var_decl) = artificial_p; + DECL_EXTERNAL (var_decl) = extern_flag; + + TREE_CONSTANT (var_decl) = constant_p; + TREE_READONLY (var_decl) = const_flag; + + /* The object is public if it is external or if it is declared public + and has static storage duration. */ + TREE_PUBLIC (var_decl) = extern_flag || (public_flag && static_storage); + + /* We need to allocate static storage for an object with static storage + duration if it isn't external. */ + TREE_STATIC (var_decl) = !extern_flag && static_storage; + + TREE_SIDE_EFFECTS (var_decl) + = TREE_THIS_VOLATILE (var_decl) + = TYPE_VOLATILE (type) | volatile_flag; + + if (TREE_SIDE_EFFECTS (var_decl)) + TREE_ADDRESSABLE (var_decl) = 1; + + /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't + try to fiddle with DECL_COMMON. However, on platforms that don't + support global BSS sections, uninitialized global variables would + go in DATA instead, thus increasing the size of the executable. */ + if (!flag_no_common + && TREE_CODE (var_decl) == VAR_DECL + && TREE_PUBLIC (var_decl) + && !have_global_bss_p ()) + DECL_COMMON (var_decl) = 1; + + /* Do not emit debug info for a CONST_DECL if optimization isn't enabled, + since we will create an associated variable. Likewise for an external + constant whose initializer is not absolute, because this would mean a + global relocation in a read-only section which runs afoul of the PE-COFF + run-time relocation mechanism. */ + if (!debug_info_p + || (TREE_CODE (var_decl) == CONST_DECL && !optimize) + || (extern_flag + && constant_p + && init + && initializer_constant_valid_p (init, TREE_TYPE (init)) + != null_pointer_node)) + DECL_IGNORED_P (var_decl) = 1; + + /* ??? Some attributes cannot be applied to CONST_DECLs. */ + if (TREE_CODE (var_decl) == VAR_DECL) + process_attributes (&var_decl, &attr_list, true, gnat_node); + + /* Add this decl to the current binding level. */ + gnat_pushdecl (var_decl, gnat_node); + + if (TREE_CODE (var_decl) == VAR_DECL && asm_name) + { + /* Let the target mangle the name if this isn't a verbatim asm. */ + if (*IDENTIFIER_POINTER (asm_name) != '*') + asm_name = targetm.mangle_decl_assembler_name (var_decl, asm_name); + + SET_DECL_ASSEMBLER_NAME (var_decl, asm_name); + } + + return var_decl; +} + +/* Return true if TYPE, an aggregate type, contains (or is) an array. */ + +static bool +aggregate_type_contains_array_p (tree type) +{ + switch (TREE_CODE (type)) + { + case RECORD_TYPE: + case UNION_TYPE: + case QUAL_UNION_TYPE: + { + tree field; + for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) + if (AGGREGATE_TYPE_P (TREE_TYPE (field)) + && aggregate_type_contains_array_p (TREE_TYPE (field))) + return true; + return false; + } + + case ARRAY_TYPE: + return true; + + default: + gcc_unreachable (); + } +} + +/* Return a FIELD_DECL node. NAME is the field's name, TYPE is its type and + RECORD_TYPE is the type of the enclosing record. If SIZE is nonzero, it + is the specified size of the field. If POS is nonzero, it is the bit + position. PACKED is 1 if the enclosing record is packed, -1 if it has + Component_Alignment of Storage_Unit. If ADDRESSABLE is nonzero, it + means we are allowed to take the address of the field; if it is negative, + we should not make a bitfield, which is used by make_aligning_type. */ + +tree +create_field_decl (tree name, tree type, tree record_type, tree size, tree pos, + int packed, int addressable) +{ + tree field_decl = build_decl (input_location, FIELD_DECL, name, type); + + DECL_CONTEXT (field_decl) = record_type; + TREE_READONLY (field_decl) = TYPE_READONLY (type); + + /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a + byte boundary since GCC cannot handle less-aligned BLKmode bitfields. + Likewise for an aggregate without specified position that contains an + array, because in this case slices of variable length of this array + must be handled by GCC and variable-sized objects need to be aligned + to at least a byte boundary. */ + if (packed && (TYPE_MODE (type) == BLKmode + || (!pos + && AGGREGATE_TYPE_P (type) + && aggregate_type_contains_array_p (type)))) + SET_DECL_ALIGN (field_decl, BITS_PER_UNIT); + + /* If a size is specified, use it. Otherwise, if the record type is packed + compute a size to use, which may differ from the object's natural size. + We always set a size in this case to trigger the checks for bitfield + creation below, which is typically required when no position has been + specified. */ + if (size) + size = convert (bitsizetype, size); + else if (packed == 1) + { + size = rm_size (type); + if (TYPE_MODE (type) == BLKmode) + size = round_up (size, BITS_PER_UNIT); + } + + /* If we may, according to ADDRESSABLE, make a bitfield if a size is + specified for two reasons: first if the size differs from the natural + size. Second, if the alignment is insufficient. There are a number of + ways the latter can be true. + + We never make a bitfield if the type of the field has a nonconstant size, + because no such entity requiring bitfield operations should reach here. + + We do *preventively* make a bitfield when there might be the need for it + but we don't have all the necessary information to decide, as is the case + of a field with no specified position in a packed record. + + We also don't look at STRICT_ALIGNMENT here, and rely on later processing + in layout_decl or finish_record_type to clear the bit_field indication if + it is in fact not needed. */ + if (addressable >= 0 + && size + && TREE_CODE (size) == INTEGER_CST + && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST + && (!tree_int_cst_equal (size, TYPE_SIZE (type)) + || (pos && !value_factor_p (pos, TYPE_ALIGN (type))) + || packed + || (TYPE_ALIGN (record_type) != 0 + && TYPE_ALIGN (record_type) < TYPE_ALIGN (type)))) + { + DECL_BIT_FIELD (field_decl) = 1; + DECL_SIZE (field_decl) = size; + if (!packed && !pos) + { + if (TYPE_ALIGN (record_type) != 0 + && TYPE_ALIGN (record_type) < TYPE_ALIGN (type)) + SET_DECL_ALIGN (field_decl, TYPE_ALIGN (record_type)); + else + SET_DECL_ALIGN (field_decl, TYPE_ALIGN (type)); + } + } + + DECL_PACKED (field_decl) = pos ? DECL_BIT_FIELD (field_decl) : packed; + + /* Bump the alignment if need be, either for bitfield/packing purposes or + to satisfy the type requirements if no such consideration applies. When + we get the alignment from the type, indicate if this is from an explicit + user request, which prevents stor-layout from lowering it later on. */ + { + unsigned int bit_align + = (DECL_BIT_FIELD (field_decl) ? 1 + : packed && TYPE_MODE (type) != BLKmode ? BITS_PER_UNIT : 0); + + if (bit_align > DECL_ALIGN (field_decl)) + SET_DECL_ALIGN (field_decl, bit_align); + else if (!bit_align && TYPE_ALIGN (type) > DECL_ALIGN (field_decl)) + { + SET_DECL_ALIGN (field_decl, TYPE_ALIGN (type)); + DECL_USER_ALIGN (field_decl) = TYPE_USER_ALIGN (type); + } + } + + if (pos) + { + /* We need to pass in the alignment the DECL is known to have. + This is the lowest-order bit set in POS, but no more than + the alignment of the record, if one is specified. Note + that an alignment of 0 is taken as infinite. */ + unsigned int known_align; + + if (tree_fits_uhwi_p (pos)) + known_align = tree_to_uhwi (pos) & - tree_to_uhwi (pos); + else + known_align = BITS_PER_UNIT; + + if (TYPE_ALIGN (record_type) + && (known_align == 0 || known_align > TYPE_ALIGN (record_type))) + known_align = TYPE_ALIGN (record_type); + + layout_decl (field_decl, known_align); + SET_DECL_OFFSET_ALIGN (field_decl, + tree_fits_uhwi_p (pos) ? BIGGEST_ALIGNMENT + : BITS_PER_UNIT); + pos_from_bit (&DECL_FIELD_OFFSET (field_decl), + &DECL_FIELD_BIT_OFFSET (field_decl), + DECL_OFFSET_ALIGN (field_decl), pos); + } + + /* In addition to what our caller says, claim the field is addressable if we + know that its type is not suitable. + + The field may also be "technically" nonaddressable, meaning that even if + we attempt to take the field's address we will actually get the address + of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD + value we have at this point is not accurate enough, so we don't account + for this here and let finish_record_type decide. */ + if (!addressable && !type_for_nonaliased_component_p (type)) + addressable = 1; + + DECL_NONADDRESSABLE_P (field_decl) = !addressable; + + return field_decl; +} + +/* Return a PARM_DECL node with NAME and TYPE. */ + +tree +create_param_decl (tree name, tree type) +{ + tree param_decl = build_decl (input_location, PARM_DECL, name, type); + + /* Honor TARGET_PROMOTE_PROTOTYPES like the C compiler, as not doing so + can lead to various ABI violations. */ + if (targetm.calls.promote_prototypes (NULL_TREE) + && INTEGRAL_TYPE_P (type) + && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) + { + /* We have to be careful about biased types here. Make a subtype + of integer_type_node with the proper biasing. */ + if (TREE_CODE (type) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (type)) + { + tree subtype + = make_unsigned_type (TYPE_PRECISION (integer_type_node)); + TREE_TYPE (subtype) = integer_type_node; + TYPE_BIASED_REPRESENTATION_P (subtype) = 1; + SET_TYPE_RM_MIN_VALUE (subtype, TYPE_MIN_VALUE (type)); + SET_TYPE_RM_MAX_VALUE (subtype, TYPE_MAX_VALUE (type)); + type = subtype; + } + else + type = integer_type_node; + } + + DECL_ARG_TYPE (param_decl) = type; + return param_decl; +} + +/* Process the attributes in ATTR_LIST for NODE, which is either a DECL or + a TYPE. If IN_PLACE is true, the tree pointed to by NODE should not be + changed. GNAT_NODE is used for the position of error messages. */ + +void +process_attributes (tree *node, struct attrib **attr_list, bool in_place, + Node_Id gnat_node) +{ + struct attrib *attr; + + for (attr = *attr_list; attr; attr = attr->next) + switch (attr->type) + { + case ATTR_MACHINE_ATTRIBUTE: + Sloc_to_locus (Sloc (gnat_node), &input_location); + decl_attributes (node, tree_cons (attr->name, attr->args, NULL_TREE), + in_place ? ATTR_FLAG_TYPE_IN_PLACE : 0); + break; + + case ATTR_LINK_ALIAS: + if (!DECL_EXTERNAL (*node)) + { + TREE_STATIC (*node) = 1; + assemble_alias (*node, attr->name); + } + break; + + case ATTR_WEAK_EXTERNAL: + if (SUPPORTS_WEAK) + declare_weak (*node); + else + post_error ("?weak declarations not supported on this target", + attr->error_point); + break; + + case ATTR_LINK_SECTION: + if (targetm_common.have_named_sections) + { + set_decl_section_name (*node, IDENTIFIER_POINTER (attr->name)); + DECL_COMMON (*node) = 0; + } + else + post_error ("?section attributes are not supported for this target", + attr->error_point); + break; + + case ATTR_LINK_CONSTRUCTOR: + DECL_STATIC_CONSTRUCTOR (*node) = 1; + TREE_USED (*node) = 1; + break; + + case ATTR_LINK_DESTRUCTOR: + DECL_STATIC_DESTRUCTOR (*node) = 1; + TREE_USED (*node) = 1; + break; + + case ATTR_THREAD_LOCAL_STORAGE: + set_decl_tls_model (*node, decl_default_tls_model (*node)); + DECL_COMMON (*node) = 0; + break; + } + + *attr_list = NULL; +} + +/* Return true if VALUE is a known to be a multiple of FACTOR, which must be + a power of 2. */ + +bool +value_factor_p (tree value, HOST_WIDE_INT factor) +{ + if (tree_fits_uhwi_p (value)) + return tree_to_uhwi (value) % factor == 0; + + if (TREE_CODE (value) == MULT_EXPR) + return (value_factor_p (TREE_OPERAND (value, 0), factor) + || value_factor_p (TREE_OPERAND (value, 1), factor)); + + return false; +} + +/* Return whether GNAT_NODE is a defining identifier for a renaming that comes + from the parameter association for the instantiation of a generic. We do + not want to emit source location for them: the code generated for their + initialization is likely to disturb debugging. */ + +bool +renaming_from_instantiation_p (Node_Id gnat_node) +{ + if (Nkind (gnat_node) != N_Defining_Identifier + || !Is_Object (gnat_node) + || Comes_From_Source (gnat_node) + || !Present (Renamed_Object (gnat_node))) + return false; + + /* Get the object declaration of the renamed object, if any and if the + renamed object is a mere identifier. */ + gnat_node = Renamed_Object (gnat_node); + if (Nkind (gnat_node) != N_Identifier) + return false; + + gnat_node = Entity (gnat_node); + if (!Present (Parent (gnat_node))) + return false; + + gnat_node = Parent (gnat_node); + return + (Present (gnat_node) + && Nkind (gnat_node) == N_Object_Declaration + && Present (Corresponding_Generic_Association (gnat_node))); +} + +/* Defer the initialization of DECL's DECL_CONTEXT attribute, scheduling to + feed it with the elaboration of GNAT_SCOPE. */ + +static struct deferred_decl_context_node * +add_deferred_decl_context (tree decl, Entity_Id gnat_scope, int force_global) +{ + struct deferred_decl_context_node *new_node; + + new_node + = (struct deferred_decl_context_node * ) xmalloc (sizeof (*new_node)); + new_node->decl = decl; + new_node->gnat_scope = gnat_scope; + new_node->force_global = force_global; + new_node->types.create (1); + new_node->next = deferred_decl_context_queue; + deferred_decl_context_queue = new_node; + return new_node; +} + +/* Defer the initialization of TYPE's TYPE_CONTEXT attribute, scheduling to + feed it with the DECL_CONTEXT computed as part of N as soon as it is + computed. */ + +static void +add_deferred_type_context (struct deferred_decl_context_node *n, tree type) +{ + n->types.safe_push (type); +} + +/* Get the GENERIC node corresponding to GNAT_SCOPE, if available. Return + NULL_TREE if it is not available. */ + +static tree +compute_deferred_decl_context (Entity_Id gnat_scope) +{ + tree context; + + if (present_gnu_tree (gnat_scope)) + context = get_gnu_tree (gnat_scope); + else + return NULL_TREE; + + if (TREE_CODE (context) == TYPE_DECL) + { + const tree context_type = TREE_TYPE (context); + + /* Skip dummy types: only the final ones can appear in the context + chain. */ + if (TYPE_DUMMY_P (context_type)) + return NULL_TREE; + + /* ..._TYPE nodes are more useful than TYPE_DECL nodes in the context + chain. */ + else + context = context_type; + } + + return context; +} + +/* Try to process all deferred nodes in the queue. Keep in the queue the ones + that cannot be processed yet, remove the other ones. If FORCE is true, + force the processing for all nodes, use the global context when nodes don't + have a GNU translation. */ + +void +process_deferred_decl_context (bool force) +{ + struct deferred_decl_context_node **it = &deferred_decl_context_queue; + struct deferred_decl_context_node *node; + + while (*it) + { + bool processed = false; + tree context = NULL_TREE; + Entity_Id gnat_scope; + + node = *it; + + /* If FORCE, get the innermost elaborated scope. Otherwise, just try to + get the first scope. */ + gnat_scope = node->gnat_scope; + while (Present (gnat_scope)) + { + context = compute_deferred_decl_context (gnat_scope); + if (!force || context) + break; + gnat_scope = get_debug_scope (gnat_scope, NULL); + } + + /* Imported declarations must not be in a local context (i.e. not inside + a function). */ + if (context && node->force_global > 0) + { + tree ctx = context; + + while (ctx) + { + gcc_assert (TREE_CODE (ctx) != FUNCTION_DECL); + ctx = DECL_P (ctx) ? DECL_CONTEXT (ctx) : TYPE_CONTEXT (ctx); + } + } + + /* If FORCE, we want to get rid of all nodes in the queue: in case there + was no elaborated scope, use the global context. */ + if (force && !context) + context = get_global_context (); + + if (context) + { + tree t; + int i; + + DECL_CONTEXT (node->decl) = context; + + /* Propagate it to the TYPE_CONTEXT attributes of the requested + ..._TYPE nodes. */ + FOR_EACH_VEC_ELT (node->types, i, t) + { + gnat_set_type_context (t, context); + } + processed = true; + } + + /* If this node has been successfuly processed, remove it from the + queue. Then move to the next node. */ + if (processed) + { + *it = node->next; + node->types.release (); + free (node); + } + else + it = &node->next; + } +} + +/* Return VALUE scaled by the biggest power-of-2 factor of EXPR. */ + +static unsigned int +scale_by_factor_of (tree expr, unsigned int value) +{ + unsigned HOST_WIDE_INT addend = 0; + unsigned HOST_WIDE_INT factor = 1; + + /* Peel conversions around EXPR and try to extract bodies from function + calls: it is possible to get the scale factor from size functions. */ + expr = remove_conversions (expr, true); + if (TREE_CODE (expr) == CALL_EXPR) + expr = maybe_inline_call_in_expr (expr); + + /* Sometimes we get PLUS_EXPR (BIT_AND_EXPR (..., X), Y), where Y is a + multiple of the scale factor we are looking for. */ + if (TREE_CODE (expr) == PLUS_EXPR + && TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST + && tree_fits_uhwi_p (TREE_OPERAND (expr, 1))) + { + addend = TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)); + expr = TREE_OPERAND (expr, 0); + } + + /* An expression which is a bitwise AND with a mask has a power-of-2 factor + corresponding to the number of trailing zeros of the mask. */ + if (TREE_CODE (expr) == BIT_AND_EXPR + && TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST) + { + unsigned HOST_WIDE_INT mask = TREE_INT_CST_LOW (TREE_OPERAND (expr, 1)); + unsigned int i = 0; + + while ((mask & 1) == 0 && i < HOST_BITS_PER_WIDE_INT) + { + mask >>= 1; + factor *= 2; + i++; + } + } + + /* If the addend is not a multiple of the factor we found, give up. In + theory we could find a smaller common factor but it's useless for our + needs. This situation arises when dealing with a field F1 with no + alignment requirement but that is following a field F2 with such + requirements. As long as we have F2's offset, we don't need alignment + information to compute F1's. */ + if (addend % factor != 0) + factor = 1; + + return factor * value; +} + +/* Given two consecutive field decls PREV_FIELD and CURR_FIELD, return true + unless we can prove these 2 fields are laid out in such a way that no gap + exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET + is the distance in bits between the end of PREV_FIELD and the starting + position of CURR_FIELD. It is ignored if null. */ + +static bool +potential_alignment_gap (tree prev_field, tree curr_field, tree offset) +{ + /* If this is the first field of the record, there cannot be any gap */ + if (!prev_field) + return false; + + /* If the previous field is a union type, then return false: The only + time when such a field is not the last field of the record is when + there are other components at fixed positions after it (meaning there + was a rep clause for every field), in which case we don't want the + alignment constraint to override them. */ + if (TREE_CODE (TREE_TYPE (prev_field)) == QUAL_UNION_TYPE) + return false; + + /* If the distance between the end of prev_field and the beginning of + curr_field is constant, then there is a gap if the value of this + constant is not null. */ + if (offset && tree_fits_uhwi_p (offset)) + return !integer_zerop (offset); + + /* If the size and position of the previous field are constant, + then check the sum of this size and position. There will be a gap + iff it is not multiple of the current field alignment. */ + if (tree_fits_uhwi_p (DECL_SIZE (prev_field)) + && tree_fits_uhwi_p (bit_position (prev_field))) + return ((tree_to_uhwi (bit_position (prev_field)) + + tree_to_uhwi (DECL_SIZE (prev_field))) + % DECL_ALIGN (curr_field) != 0); + + /* If both the position and size of the previous field are multiples + of the current field alignment, there cannot be any gap. */ + if (value_factor_p (bit_position (prev_field), DECL_ALIGN (curr_field)) + && value_factor_p (DECL_SIZE (prev_field), DECL_ALIGN (curr_field))) + return false; + + /* Fallback, return that there may be a potential gap */ + return true; +} + +/* Return a LABEL_DECL with NAME. GNAT_NODE is used for the position of + the decl. */ + +tree +create_label_decl (tree name, Node_Id gnat_node) +{ + tree label_decl + = build_decl (input_location, LABEL_DECL, name, void_type_node); + + SET_DECL_MODE (label_decl, VOIDmode); + + /* Add this decl to the current binding level. */ + gnat_pushdecl (label_decl, gnat_node); + + return label_decl; +} + +/* Return a FUNCTION_DECL node. NAME is the name of the subprogram, ASM_NAME + its assembler name, TYPE its type (a FUNCTION_TYPE node), PARAM_DECL_LIST + the list of its parameters (a list of PARM_DECL nodes chained through the + DECL_CHAIN field). + + INLINE_STATUS describes the inline flags to be set on the FUNCTION_DECL. + + PUBLIC_FLAG is true if this is for a reference to a public entity or for a + definition to be made visible outside of the current compilation unit. + + EXTERN_FLAG is true when processing an external subprogram declaration. + + ARTIFICIAL_P is true if the subprogram was generated by the compiler. + + DEBUG_INFO_P is true if we need to write debug information for it. + + DEFINITION is true if the subprogram is to be considered as a definition. + + ATTR_LIST is the list of attributes to be attached to the subprogram. + + GNAT_NODE is used for the position of the decl. */ + +tree +create_subprog_decl (tree name, tree asm_name, tree type, tree param_decl_list, + enum inline_status_t inline_status, bool public_flag, + bool extern_flag, bool artificial_p, bool debug_info_p, + bool definition, struct attrib *attr_list, + Node_Id gnat_node) +{ + tree subprog_decl = build_decl (input_location, FUNCTION_DECL, name, type); + DECL_ARGUMENTS (subprog_decl) = param_decl_list; + + DECL_ARTIFICIAL (subprog_decl) = artificial_p; + DECL_EXTERNAL (subprog_decl) = extern_flag; + TREE_PUBLIC (subprog_decl) = public_flag; + + if (!debug_info_p) + DECL_IGNORED_P (subprog_decl) = 1; + if (definition) + DECL_FUNCTION_IS_DEF (subprog_decl) = 1; + + switch (inline_status) + { + case is_suppressed: + DECL_UNINLINABLE (subprog_decl) = 1; + break; + + case is_disabled: + break; + + case is_required: + if (Back_End_Inlining) + { + decl_attributes (&subprog_decl, + tree_cons (get_identifier ("always_inline"), + NULL_TREE, NULL_TREE), + ATTR_FLAG_TYPE_IN_PLACE); + + /* Inline_Always guarantees that every direct call is inlined and + that there is no indirect reference to the subprogram, so the + instance in the original package (as well as its clones in the + client packages created for inter-unit inlining) can be made + private, which causes the out-of-line body to be eliminated. */ + TREE_PUBLIC (subprog_decl) = 0; + } + + /* ... fall through ... */ + + case is_enabled: + DECL_DECLARED_INLINE_P (subprog_decl) = 1; + DECL_NO_INLINE_WARNING_P (subprog_decl) = artificial_p; + break; + + default: + gcc_unreachable (); + } + + process_attributes (&subprog_decl, &attr_list, true, gnat_node); + + /* Once everything is processed, finish the subprogram declaration. */ + finish_subprog_decl (subprog_decl, asm_name, type); + + /* Add this decl to the current binding level. */ + gnat_pushdecl (subprog_decl, gnat_node); + + /* Output the assembler code and/or RTL for the declaration. */ + rest_of_decl_compilation (subprog_decl, global_bindings_p (), 0); + + return subprog_decl; +} + +/* Given a subprogram declaration DECL, its assembler name and its type, + finish constructing the subprogram declaration from ASM_NAME and TYPE. */ + +void +finish_subprog_decl (tree decl, tree asm_name, tree type) +{ + tree result_decl + = build_decl (DECL_SOURCE_LOCATION (decl), RESULT_DECL, NULL_TREE, + TREE_TYPE (type)); + + DECL_ARTIFICIAL (result_decl) = 1; + DECL_IGNORED_P (result_decl) = 1; + DECL_BY_REFERENCE (result_decl) = TREE_ADDRESSABLE (type); + DECL_RESULT (decl) = result_decl; + + TREE_READONLY (decl) = TYPE_READONLY (type); + TREE_SIDE_EFFECTS (decl) = TREE_THIS_VOLATILE (decl) = TYPE_VOLATILE (type); + + if (asm_name) + { + /* Let the target mangle the name if this isn't a verbatim asm. */ + if (*IDENTIFIER_POINTER (asm_name) != '*') + asm_name = targetm.mangle_decl_assembler_name (decl, asm_name); + + SET_DECL_ASSEMBLER_NAME (decl, asm_name); + + /* The expand_main_function circuitry expects "main_identifier_node" to + designate the DECL_NAME of the 'main' entry point, in turn expected + to be declared as the "main" function literally by default. Ada + program entry points are typically declared with a different name + within the binder generated file, exported as 'main' to satisfy the + system expectations. Force main_identifier_node in this case. */ + if (asm_name == main_identifier_node) + DECL_NAME (decl) = main_identifier_node; + } +} + +/* Set up the framework for generating code for SUBPROG_DECL, a subprogram + body. This routine needs to be invoked before processing the declarations + appearing in the subprogram. */ + +void +begin_subprog_body (tree subprog_decl) +{ + tree param_decl; + + announce_function (subprog_decl); + + /* This function is being defined. */ + TREE_STATIC (subprog_decl) = 1; + + /* The failure of this assertion will likely come from a wrong context for + the subprogram body, e.g. another procedure for a procedure declared at + library level. */ + gcc_assert (current_function_decl == decl_function_context (subprog_decl)); + + current_function_decl = subprog_decl; + + /* Enter a new binding level and show that all the parameters belong to + this function. */ + gnat_pushlevel (); + + for (param_decl = DECL_ARGUMENTS (subprog_decl); param_decl; + param_decl = DECL_CHAIN (param_decl)) + DECL_CONTEXT (param_decl) = subprog_decl; + + make_decl_rtl (subprog_decl); +} + +/* Finish translating the current subprogram and set its BODY. */ + +void +end_subprog_body (tree body) +{ + tree fndecl = current_function_decl; + + /* Attach the BLOCK for this level to the function and pop the level. */ + BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl; + DECL_INITIAL (fndecl) = current_binding_level->block; + gnat_poplevel (); + + /* Mark the RESULT_DECL as being in this subprogram. */ + DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; + + /* The body should be a BIND_EXPR whose BLOCK is the top-level one. */ + if (TREE_CODE (body) == BIND_EXPR) + { + BLOCK_SUPERCONTEXT (BIND_EXPR_BLOCK (body)) = fndecl; + DECL_INITIAL (fndecl) = BIND_EXPR_BLOCK (body); + } + + DECL_SAVED_TREE (fndecl) = body; + + current_function_decl = decl_function_context (fndecl); +} + +/* Wrap up compilation of SUBPROG_DECL, a subprogram body. */ + +void +rest_of_subprog_body_compilation (tree subprog_decl) +{ + /* We cannot track the location of errors past this point. */ + error_gnat_node = Empty; + + /* If we're only annotating types, don't actually compile this function. */ + if (type_annotate_only) + return; + + /* Dump functions before gimplification. */ + dump_function (TDI_original, subprog_decl); + + if (!decl_function_context (subprog_decl)) + cgraph_node::finalize_function (subprog_decl, false); + else + /* Register this function with cgraph just far enough to get it + added to our parent's nested function list. */ + (void) cgraph_node::get_create (subprog_decl); +} + +tree +gnat_builtin_function (tree decl) +{ + gnat_pushdecl (decl, Empty); + return decl; +} + +/* Return an integer type with the number of bits of precision given by + PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise + it is a signed type. */ + +tree +gnat_type_for_size (unsigned precision, int unsignedp) +{ + tree t; + char type_name[20]; + + if (precision <= 2 * MAX_BITS_PER_WORD + && signed_and_unsigned_types[precision][unsignedp]) + return signed_and_unsigned_types[precision][unsignedp]; + + if (unsignedp) + t = make_unsigned_type (precision); + else + t = make_signed_type (precision); + TYPE_ARTIFICIAL (t) = 1; + + if (precision <= 2 * MAX_BITS_PER_WORD) + signed_and_unsigned_types[precision][unsignedp] = t; + + if (!TYPE_NAME (t)) + { + sprintf (type_name, "%sSIGNED_%u", unsignedp ? "UN" : "", precision); + TYPE_NAME (t) = get_identifier (type_name); + } + + return t; +} + +/* Likewise for floating-point types. */ + +static tree +float_type_for_precision (int precision, machine_mode mode) +{ + tree t; + char type_name[20]; + + if (float_types[(int) mode]) + return float_types[(int) mode]; + + float_types[(int) mode] = t = make_node (REAL_TYPE); + TYPE_PRECISION (t) = precision; + layout_type (t); + + gcc_assert (TYPE_MODE (t) == mode); + if (!TYPE_NAME (t)) + { + sprintf (type_name, "FLOAT_%d", precision); + TYPE_NAME (t) = get_identifier (type_name); + } + + return t; +} + +/* Return a data type that has machine mode MODE. UNSIGNEDP selects + an unsigned type; otherwise a signed type is returned. */ + +tree +gnat_type_for_mode (machine_mode mode, int unsignedp) +{ + if (mode == BLKmode) + return NULL_TREE; + + if (mode == VOIDmode) + return void_type_node; + + if (COMPLEX_MODE_P (mode)) + return NULL_TREE; + + scalar_float_mode float_mode; + if (is_a <scalar_float_mode> (mode, &float_mode)) + return float_type_for_precision (GET_MODE_PRECISION (float_mode), + float_mode); + + scalar_int_mode int_mode; + if (is_a <scalar_int_mode> (mode, &int_mode)) + return gnat_type_for_size (GET_MODE_BITSIZE (int_mode), unsignedp); + + if (VECTOR_MODE_P (mode)) + { + machine_mode inner_mode = GET_MODE_INNER (mode); + tree inner_type = gnat_type_for_mode (inner_mode, unsignedp); + if (inner_type) + return build_vector_type_for_mode (inner_type, mode); + } + + return NULL_TREE; +} + +/* Return the signed or unsigned version of TYPE_NODE, a scalar type, the + signedness being specified by UNSIGNEDP. */ + +tree +gnat_signed_or_unsigned_type_for (int unsignedp, tree type_node) +{ + if (type_node == char_type_node) + return unsignedp ? unsigned_char_type_node : signed_char_type_node; + + tree type = gnat_type_for_size (TYPE_PRECISION (type_node), unsignedp); + + if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node)) + { + type = copy_type (type); + TREE_TYPE (type) = type_node; + } + else if (TREE_TYPE (type_node) + && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE + && TYPE_MODULAR_P (TREE_TYPE (type_node))) + { + type = copy_type (type); + TREE_TYPE (type) = TREE_TYPE (type_node); + } + + return type; +} + +/* Return 1 if the types T1 and T2 are compatible, i.e. if they can be + transparently converted to each other. */ + +int +gnat_types_compatible_p (tree t1, tree t2) +{ + enum tree_code code; + + /* This is the default criterion. */ + if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) + return 1; + + /* We only check structural equivalence here. */ + if ((code = TREE_CODE (t1)) != TREE_CODE (t2)) + return 0; + + /* Vector types are also compatible if they have the same number of subparts + and the same form of (scalar) element type. */ + if (code == VECTOR_TYPE + && TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2) + && TREE_CODE (TREE_TYPE (t1)) == TREE_CODE (TREE_TYPE (t2)) + && TYPE_PRECISION (TREE_TYPE (t1)) == TYPE_PRECISION (TREE_TYPE (t2))) + return 1; + + /* Array types are also compatible if they are constrained and have the same + domain(s), the same component type and the same scalar storage order. */ + if (code == ARRAY_TYPE + && (TYPE_DOMAIN (t1) == TYPE_DOMAIN (t2) + || (TYPE_DOMAIN (t1) + && TYPE_DOMAIN (t2) + && tree_int_cst_equal (TYPE_MIN_VALUE (TYPE_DOMAIN (t1)), + TYPE_MIN_VALUE (TYPE_DOMAIN (t2))) + && tree_int_cst_equal (TYPE_MAX_VALUE (TYPE_DOMAIN (t1)), + TYPE_MAX_VALUE (TYPE_DOMAIN (t2))))) + && (TREE_TYPE (t1) == TREE_TYPE (t2) + || (TREE_CODE (TREE_TYPE (t1)) == ARRAY_TYPE + && gnat_types_compatible_p (TREE_TYPE (t1), TREE_TYPE (t2)))) + && TYPE_REVERSE_STORAGE_ORDER (t1) == TYPE_REVERSE_STORAGE_ORDER (t2)) + return 1; + + return 0; +} + +/* Return true if EXPR is a useless type conversion. */ + +bool +gnat_useless_type_conversion (tree expr) +{ + if (CONVERT_EXPR_P (expr) + || TREE_CODE (expr) == VIEW_CONVERT_EXPR + || TREE_CODE (expr) == NON_LVALUE_EXPR) + return gnat_types_compatible_p (TREE_TYPE (expr), + TREE_TYPE (TREE_OPERAND (expr, 0))); + + return false; +} + +/* Return true if T, a FUNCTION_TYPE, has the specified list of flags. */ + +bool +fntype_same_flags_p (const_tree t, tree cico_list, bool return_unconstrained_p, + bool return_by_direct_ref_p, bool return_by_invisi_ref_p) +{ + return TYPE_CI_CO_LIST (t) == cico_list + && TYPE_RETURN_UNCONSTRAINED_P (t) == return_unconstrained_p + && TYPE_RETURN_BY_DIRECT_REF_P (t) == return_by_direct_ref_p + && TREE_ADDRESSABLE (t) == return_by_invisi_ref_p; +} + +/* EXP is an expression for the size of an object. If this size contains + discriminant references, replace them with the maximum (if MAX_P) or + minimum (if !MAX_P) possible value of the discriminant. */ + +tree +max_size (tree exp, bool max_p) +{ + enum tree_code code = TREE_CODE (exp); + tree type = TREE_TYPE (exp); + tree op0, op1, op2; + + switch (TREE_CODE_CLASS (code)) + { + case tcc_declaration: + case tcc_constant: + return exp; + + case tcc_exceptional: + gcc_assert (code == SSA_NAME); + return exp; + + case tcc_vl_exp: + if (code == CALL_EXPR) + { + tree t, *argarray; + int n, i; + + t = maybe_inline_call_in_expr (exp); + if (t) + return max_size (t, max_p); + + n = call_expr_nargs (exp); + gcc_assert (n > 0); + argarray = XALLOCAVEC (tree, n); + for (i = 0; i < n; i++) + argarray[i] = max_size (CALL_EXPR_ARG (exp, i), max_p); + return build_call_array (type, CALL_EXPR_FN (exp), n, argarray); + } + break; + + case tcc_reference: + /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to + modify. Otherwise, we treat it like a variable. */ + if (CONTAINS_PLACEHOLDER_P (exp)) + { + tree val_type = TREE_TYPE (TREE_OPERAND (exp, 1)); + tree val = (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type)); + return + convert (type, + max_size (convert (get_base_type (val_type), val), true)); + } + + return exp; + + case tcc_comparison: + return build_int_cst (type, max_p ? 1 : 0); + + case tcc_unary: + if (code == NON_LVALUE_EXPR) + return max_size (TREE_OPERAND (exp, 0), max_p); + + op0 = max_size (TREE_OPERAND (exp, 0), + code == NEGATE_EXPR ? !max_p : max_p); + + if (op0 == TREE_OPERAND (exp, 0)) + return exp; + + return fold_build1 (code, type, op0); + + case tcc_binary: + { + tree lhs = max_size (TREE_OPERAND (exp, 0), max_p); + tree rhs = max_size (TREE_OPERAND (exp, 1), + code == MINUS_EXPR ? !max_p : max_p); + + /* Special-case wanting the maximum value of a MIN_EXPR. + In that case, if one side overflows, return the other. */ + if (max_p && code == MIN_EXPR) + { + if (TREE_CODE (rhs) == INTEGER_CST && TREE_OVERFLOW (rhs)) + return lhs; + + if (TREE_CODE (lhs) == INTEGER_CST && TREE_OVERFLOW (lhs)) + return rhs; + } + + /* Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS + overflowing and the RHS a variable. */ + if ((code == MINUS_EXPR || code == PLUS_EXPR) + && TREE_CODE (lhs) == INTEGER_CST + && TREE_OVERFLOW (lhs) + && TREE_CODE (rhs) != INTEGER_CST) + return lhs; + + /* If we are going to subtract a "negative" value in an unsigned type, + do the operation as an addition of the negated value, in order to + avoid creating a spurious overflow below. */ + if (code == MINUS_EXPR + && TYPE_UNSIGNED (type) + && TREE_CODE (rhs) == INTEGER_CST + && !TREE_OVERFLOW (rhs) + && tree_int_cst_sign_bit (rhs) != 0) + { + rhs = fold_build1 (NEGATE_EXPR, type, rhs); + code = PLUS_EXPR; + } + + if (lhs == TREE_OPERAND (exp, 0) && rhs == TREE_OPERAND (exp, 1)) + return exp; + + /* We need to detect overflows so we call size_binop here. */ + return size_binop (code, lhs, rhs); + } + + case tcc_expression: + switch (TREE_CODE_LENGTH (code)) + { + case 1: + if (code == SAVE_EXPR) + return exp; + + op0 = max_size (TREE_OPERAND (exp, 0), + code == TRUTH_NOT_EXPR ? !max_p : max_p); + + if (op0 == TREE_OPERAND (exp, 0)) + return exp; + + return fold_build1 (code, type, op0); + + case 2: + if (code == COMPOUND_EXPR) + return max_size (TREE_OPERAND (exp, 1), max_p); + + op0 = max_size (TREE_OPERAND (exp, 0), max_p); + op1 = max_size (TREE_OPERAND (exp, 1), max_p); + + if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)) + return exp; + + return fold_build2 (code, type, op0, op1); + + case 3: + if (code == COND_EXPR) + { + op1 = TREE_OPERAND (exp, 1); + op2 = TREE_OPERAND (exp, 2); + + if (!op1 || !op2) + return exp; + + return + fold_build2 (max_p ? MAX_EXPR : MIN_EXPR, type, + max_size (op1, max_p), max_size (op2, max_p)); + } + break; + + default: + break; + } + + /* Other tree classes cannot happen. */ + default: + break; + } + + gcc_unreachable (); +} + +/* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE. + EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs. + Return a constructor for the template. */ + +tree +build_template (tree template_type, tree array_type, tree expr) +{ + vec<constructor_elt, va_gc> *template_elts = NULL; + tree bound_list = NULL_TREE; + tree field; + + while (TREE_CODE (array_type) == RECORD_TYPE + && (TYPE_PADDING_P (array_type) + || TYPE_JUSTIFIED_MODULAR_P (array_type))) + array_type = TREE_TYPE (TYPE_FIELDS (array_type)); + + if (TREE_CODE (array_type) == ARRAY_TYPE + || (TREE_CODE (array_type) == INTEGER_TYPE + && TYPE_HAS_ACTUAL_BOUNDS_P (array_type))) + bound_list = TYPE_ACTUAL_BOUNDS (array_type); + + /* First make the list for a CONSTRUCTOR for the template. Go down the + field list of the template instead of the type chain because this + array might be an Ada array of arrays and we can't tell where the + nested arrays stop being the underlying object. */ + + for (field = TYPE_FIELDS (template_type); field; + (bound_list + ? (bound_list = TREE_CHAIN (bound_list)) + : (array_type = TREE_TYPE (array_type))), + field = DECL_CHAIN (DECL_CHAIN (field))) + { + tree bounds, min, max; + + /* If we have a bound list, get the bounds from there. Likewise + for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with + DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template. + This will give us a maximum range. */ + if (bound_list) + bounds = TREE_VALUE (bound_list); + else if (TREE_CODE (array_type) == ARRAY_TYPE) + bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type)); + else if (expr && TREE_CODE (expr) == PARM_DECL + && DECL_BY_COMPONENT_PTR_P (expr)) + bounds = TREE_TYPE (field); + else + gcc_unreachable (); + + min = convert (TREE_TYPE (field), TYPE_MIN_VALUE (bounds)); + max = convert (TREE_TYPE (DECL_CHAIN (field)), TYPE_MAX_VALUE (bounds)); + + /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must + substitute it from OBJECT. */ + min = SUBSTITUTE_PLACEHOLDER_IN_EXPR (min, expr); + max = SUBSTITUTE_PLACEHOLDER_IN_EXPR (max, expr); + + CONSTRUCTOR_APPEND_ELT (template_elts, field, min); + CONSTRUCTOR_APPEND_ELT (template_elts, DECL_CHAIN (field), max); + } + + return gnat_build_constructor (template_type, template_elts); +} + +/* Return true if TYPE is suitable for the element type of a vector. */ + +static bool +type_for_vector_element_p (tree type) +{ + machine_mode mode; + + if (!INTEGRAL_TYPE_P (type) + && !SCALAR_FLOAT_TYPE_P (type) + && !FIXED_POINT_TYPE_P (type)) + return false; + + mode = TYPE_MODE (type); + if (GET_MODE_CLASS (mode) != MODE_INT + && !SCALAR_FLOAT_MODE_P (mode) + && !ALL_SCALAR_FIXED_POINT_MODE_P (mode)) + return false; + + return true; +} + +/* Return a vector type given the SIZE and the INNER_TYPE, or NULL_TREE if + this is not possible. If ATTRIBUTE is non-zero, we are processing the + attribute declaration and want to issue error messages on failure. */ + +static tree +build_vector_type_for_size (tree inner_type, tree size, tree attribute) +{ + unsigned HOST_WIDE_INT size_int, inner_size_int; + int nunits; + + /* Silently punt on variable sizes. We can't make vector types for them, + need to ignore them on front-end generated subtypes of unconstrained + base types, and this attribute is for binding implementors, not end + users, so we should never get there from legitimate explicit uses. */ + if (!tree_fits_uhwi_p (size)) + return NULL_TREE; + size_int = tree_to_uhwi (size); + + if (!type_for_vector_element_p (inner_type)) + { + if (attribute) + error ("invalid element type for attribute %qs", + IDENTIFIER_POINTER (attribute)); + return NULL_TREE; + } + inner_size_int = tree_to_uhwi (TYPE_SIZE_UNIT (inner_type)); + + if (size_int % inner_size_int) + { + if (attribute) + error ("vector size not an integral multiple of component size"); + return NULL_TREE; + } + + if (size_int == 0) + { + if (attribute) + error ("zero vector size"); + return NULL_TREE; + } + + nunits = size_int / inner_size_int; + if (nunits & (nunits - 1)) + { + if (attribute) + error ("number of components of vector not a power of two"); + return NULL_TREE; + } + + return build_vector_type (inner_type, nunits); +} + +/* Return a vector type whose representative array type is ARRAY_TYPE, or + NULL_TREE if this is not possible. If ATTRIBUTE is non-zero, we are + processing the attribute and want to issue error messages on failure. */ + +static tree +build_vector_type_for_array (tree array_type, tree attribute) +{ + tree vector_type = build_vector_type_for_size (TREE_TYPE (array_type), + TYPE_SIZE_UNIT (array_type), + attribute); + if (!vector_type) + return NULL_TREE; + + TYPE_REPRESENTATIVE_ARRAY (vector_type) = array_type; + return vector_type; +} + +/* Build a type to be used to represent an aliased object whose nominal type + is an unconstrained array. This consists of a RECORD_TYPE containing a + field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an ARRAY_TYPE. + If ARRAY_TYPE is that of an unconstrained array, this is used to represent + an arbitrary unconstrained object. Use NAME as the name of the record. + DEBUG_INFO_P is true if we need to write debug information for the type. */ + +tree +build_unc_object_type (tree template_type, tree object_type, tree name, + bool debug_info_p) +{ + tree decl; + tree type = make_node (RECORD_TYPE); + tree template_field + = create_field_decl (get_identifier ("BOUNDS"), template_type, type, + NULL_TREE, NULL_TREE, 0, 1); + tree array_field + = create_field_decl (get_identifier ("ARRAY"), object_type, type, + NULL_TREE, NULL_TREE, 0, 1); + + TYPE_NAME (type) = name; + TYPE_CONTAINS_TEMPLATE_P (type) = 1; + DECL_CHAIN (template_field) = array_field; + finish_record_type (type, template_field, 0, true); + + /* Declare it now since it will never be declared otherwise. This is + necessary to ensure that its subtrees are properly marked. */ + decl = create_type_decl (name, type, true, debug_info_p, Empty); + + /* template_type will not be used elsewhere than here, so to keep the debug + info clean and in order to avoid scoping issues, make decl its + context. */ + gnat_set_type_context (template_type, decl); + + return type; +} + +/* Same, taking a thin or fat pointer type instead of a template type. */ + +tree +build_unc_object_type_from_ptr (tree thin_fat_ptr_type, tree object_type, + tree name, bool debug_info_p) +{ + tree template_type; + + gcc_assert (TYPE_IS_FAT_OR_THIN_POINTER_P (thin_fat_ptr_type)); + + template_type + = (TYPE_IS_FAT_POINTER_P (thin_fat_ptr_type) + ? TREE_TYPE (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (thin_fat_ptr_type)))) + : TREE_TYPE (TYPE_FIELDS (TREE_TYPE (thin_fat_ptr_type)))); + + return + build_unc_object_type (template_type, object_type, name, debug_info_p); +} + +/* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE. + In the normal case this is just two adjustments, but we have more to + do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */ + +void +update_pointer_to (tree old_type, tree new_type) +{ + tree ptr = TYPE_POINTER_TO (old_type); + tree ref = TYPE_REFERENCE_TO (old_type); + tree t; + + /* If this is the main variant, process all the other variants first. */ + if (TYPE_MAIN_VARIANT (old_type) == old_type) + for (t = TYPE_NEXT_VARIANT (old_type); t; t = TYPE_NEXT_VARIANT (t)) + update_pointer_to (t, new_type); + + /* If no pointers and no references, we are done. */ + if (!ptr && !ref) + return; + + /* Merge the old type qualifiers in the new type. + + Each old variant has qualifiers for specific reasons, and the new + designated type as well. Each set of qualifiers represents useful + information grabbed at some point, and merging the two simply unifies + these inputs into the final type description. + + Consider for instance a volatile type frozen after an access to constant + type designating it; after the designated type's freeze, we get here with + a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created + when the access type was processed. We will make a volatile and readonly + designated type, because that's what it really is. + + We might also get here for a non-dummy OLD_TYPE variant with different + qualifiers than those of NEW_TYPE, for instance in some cases of pointers + to private record type elaboration (see the comments around the call to + this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge + the qualifiers in those cases too, to avoid accidentally discarding the + initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */ + new_type + = build_qualified_type (new_type, + TYPE_QUALS (old_type) | TYPE_QUALS (new_type)); + + /* If old type and new type are identical, there is nothing to do. */ + if (old_type == new_type) + return; + + /* Otherwise, first handle the simple case. */ + if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE) + { + tree new_ptr, new_ref; + + /* If pointer or reference already points to new type, nothing to do. + This can happen as update_pointer_to can be invoked multiple times + on the same couple of types because of the type variants. */ + if ((ptr && TREE_TYPE (ptr) == new_type) + || (ref && TREE_TYPE (ref) == new_type)) + return; + + /* Chain PTR and its variants at the end. */ + new_ptr = TYPE_POINTER_TO (new_type); + if (new_ptr) + { + while (TYPE_NEXT_PTR_TO (new_ptr)) + new_ptr = TYPE_NEXT_PTR_TO (new_ptr); + TYPE_NEXT_PTR_TO (new_ptr) = ptr; + } + else + TYPE_POINTER_TO (new_type) = ptr; + + /* Now adjust them. */ + for (; ptr; ptr = TYPE_NEXT_PTR_TO (ptr)) + for (t = TYPE_MAIN_VARIANT (ptr); t; t = TYPE_NEXT_VARIANT (t)) + { + TREE_TYPE (t) = new_type; + if (TYPE_NULL_BOUNDS (t)) + TREE_TYPE (TREE_OPERAND (TYPE_NULL_BOUNDS (t), 0)) = new_type; + } + + /* Chain REF and its variants at the end. */ + new_ref = TYPE_REFERENCE_TO (new_type); + if (new_ref) + { + while (TYPE_NEXT_REF_TO (new_ref)) + new_ref = TYPE_NEXT_REF_TO (new_ref); + TYPE_NEXT_REF_TO (new_ref) = ref; + } + else + TYPE_REFERENCE_TO (new_type) = ref; + + /* Now adjust them. */ + for (; ref; ref = TYPE_NEXT_REF_TO (ref)) + for (t = TYPE_MAIN_VARIANT (ref); t; t = TYPE_NEXT_VARIANT (t)) + TREE_TYPE (t) = new_type; + + TYPE_POINTER_TO (old_type) = NULL_TREE; + TYPE_REFERENCE_TO (old_type) = NULL_TREE; + } + + /* Now deal with the unconstrained array case. In this case the pointer + is actually a record where both fields are pointers to dummy nodes. + Turn them into pointers to the correct types using update_pointer_to. + Likewise for the pointer to the object record (thin pointer). */ + else + { + tree new_ptr = TYPE_POINTER_TO (new_type); + + gcc_assert (TYPE_IS_FAT_POINTER_P (ptr)); + + /* If PTR already points to NEW_TYPE, nothing to do. This can happen + since update_pointer_to can be invoked multiple times on the same + couple of types because of the type variants. */ + if (TYPE_UNCONSTRAINED_ARRAY (ptr) == new_type) + return; + + update_pointer_to + (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))), + TREE_TYPE (TREE_TYPE (TYPE_FIELDS (new_ptr)))); + + update_pointer_to + (TREE_TYPE (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (ptr)))), + TREE_TYPE (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (new_ptr))))); + + update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), + TYPE_OBJECT_RECORD_TYPE (new_type)); + + TYPE_POINTER_TO (old_type) = NULL_TREE; + TYPE_REFERENCE_TO (old_type) = NULL_TREE; + } +} + +/* Convert EXPR, a pointer to a constrained array, into a pointer to an + unconstrained one. This involves making or finding a template. */ + +static tree +convert_to_fat_pointer (tree type, tree expr) +{ + tree template_type = TREE_TYPE (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type)))); + tree p_array_type = TREE_TYPE (TYPE_FIELDS (type)); + tree etype = TREE_TYPE (expr); + tree template_addr; + vec<constructor_elt, va_gc> *v; + vec_alloc (v, 2); + + /* If EXPR is null, make a fat pointer that contains a null pointer to the + array (compare_fat_pointers ensures that this is the full discriminant) + and a valid pointer to the bounds. This latter property is necessary + since the compiler can hoist the load of the bounds done through it. */ + if (integer_zerop (expr)) + { + tree ptr_template_type = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type))); + tree null_bounds, t; + + if (TYPE_NULL_BOUNDS (ptr_template_type)) + null_bounds = TYPE_NULL_BOUNDS (ptr_template_type); + else + { + /* The template type can still be dummy at this point so we build an + empty constructor. The middle-end will fill it in with zeros. */ + t = build_constructor (template_type, NULL); + TREE_CONSTANT (t) = TREE_STATIC (t) = 1; + null_bounds = build_unary_op (ADDR_EXPR, NULL_TREE, t); + SET_TYPE_NULL_BOUNDS (ptr_template_type, null_bounds); + } + + CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (type), + fold_convert (p_array_type, null_pointer_node)); + CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (TYPE_FIELDS (type)), null_bounds); + t = build_constructor (type, v); + /* Do not set TREE_CONSTANT so as to force T to static memory. */ + TREE_CONSTANT (t) = 0; + TREE_STATIC (t) = 1; + + return t; + } + + /* If EXPR is a thin pointer, make template and data from the record. */ + if (TYPE_IS_THIN_POINTER_P (etype)) + { + tree field = TYPE_FIELDS (TREE_TYPE (etype)); + + expr = gnat_protect_expr (expr); + + /* If we have a TYPE_UNCONSTRAINED_ARRAY attached to the RECORD_TYPE, + the thin pointer value has been shifted so we shift it back to get + the template address. */ + if (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (etype))) + { + template_addr + = build_binary_op (POINTER_PLUS_EXPR, etype, expr, + fold_build1 (NEGATE_EXPR, sizetype, + byte_position + (DECL_CHAIN (field)))); + template_addr + = fold_convert (TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type))), + template_addr); + } + + /* Otherwise we explicitly take the address of the fields. */ + else + { + expr = build_unary_op (INDIRECT_REF, NULL_TREE, expr); + template_addr + = build_unary_op (ADDR_EXPR, NULL_TREE, + build_component_ref (expr, field, false)); + expr = build_unary_op (ADDR_EXPR, NULL_TREE, + build_component_ref (expr, DECL_CHAIN (field), + false)); + } + } + + /* Otherwise, build the constructor for the template. */ + else + template_addr + = build_unary_op (ADDR_EXPR, NULL_TREE, + build_template (template_type, TREE_TYPE (etype), + expr)); + + /* The final result is a constructor for the fat pointer. + + If EXPR is an argument of a foreign convention subprogram, the type it + points to is directly the component type. In this case, the expression + type may not match the corresponding FIELD_DECL type at this point, so we + call "convert" here to fix that up if necessary. This type consistency is + required, for instance because it ensures that possible later folding of + COMPONENT_REFs against this constructor always yields something of the + same type as the initial reference. + + Note that the call to "build_template" above is still fine because it + will only refer to the provided TEMPLATE_TYPE in this case. */ + CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (type), convert (p_array_type, expr)); + CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (TYPE_FIELDS (type)), template_addr); + return gnat_build_constructor (type, v); +} + +/* Create an expression whose value is that of EXPR, + converted to type TYPE. The TREE_TYPE of the value + is always TYPE. This function implements all reasonable + conversions; callers should filter out those that are + not permitted by the language being compiled. */ + +tree +convert (tree type, tree expr) +{ + tree etype = TREE_TYPE (expr); + enum tree_code ecode = TREE_CODE (etype); + enum tree_code code = TREE_CODE (type); + + /* If the expression is already of the right type, we are done. */ + if (etype == type) + return expr; + + /* If both input and output have padding and are of variable size, do this + as an unchecked conversion. Likewise if one is a mere variant of the + other, so we avoid a pointless unpad/repad sequence. */ + else if (code == RECORD_TYPE && ecode == RECORD_TYPE + && TYPE_PADDING_P (type) && TYPE_PADDING_P (etype) + && (!TREE_CONSTANT (TYPE_SIZE (type)) + || !TREE_CONSTANT (TYPE_SIZE (etype)) + || TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype) + || TYPE_NAME (TREE_TYPE (TYPE_FIELDS (type))) + == TYPE_NAME (TREE_TYPE (TYPE_FIELDS (etype))))) + ; + + /* If the output type has padding, convert to the inner type and make a + constructor to build the record, unless a variable size is involved. */ + else if (code == RECORD_TYPE && TYPE_PADDING_P (type)) + { + /* If we previously converted from another type and our type is + of variable size, remove the conversion to avoid the need for + variable-sized temporaries. Likewise for a conversion between + original and packable version. */ + if (TREE_CODE (expr) == VIEW_CONVERT_EXPR + && (!TREE_CONSTANT (TYPE_SIZE (type)) + || (ecode == RECORD_TYPE + && TYPE_NAME (etype) + == TYPE_NAME (TREE_TYPE (TREE_OPERAND (expr, 0)))))) + expr = TREE_OPERAND (expr, 0); + + /* If we are just removing the padding from expr, convert the original + object if we have variable size in order to avoid the need for some + variable-sized temporaries. Likewise if the padding is a variant + of the other, so we avoid a pointless unpad/repad sequence. */ + if (TREE_CODE (expr) == COMPONENT_REF + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (expr, 0))) + && (!TREE_CONSTANT (TYPE_SIZE (type)) + || TYPE_MAIN_VARIANT (type) + == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (expr, 0))) + || (ecode == RECORD_TYPE + && TYPE_NAME (etype) + == TYPE_NAME (TREE_TYPE (TYPE_FIELDS (type)))))) + return convert (type, TREE_OPERAND (expr, 0)); + + /* If the inner type is of self-referential size and the expression type + is a record, do this as an unchecked conversion unless both types are + essentially the same. But first pad the expression if possible to + have the same size on both sides. */ + if (ecode == RECORD_TYPE + && CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type))) + && TYPE_MAIN_VARIANT (etype) + != TYPE_MAIN_VARIANT (TREE_TYPE (TYPE_FIELDS (type)))) + { + if (TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST) + expr = convert (maybe_pad_type (etype, TYPE_SIZE (type), 0, Empty, + false, false, false, true), + expr); + return unchecked_convert (type, expr, false); + } + + /* If we are converting between array types with variable size, do the + final conversion as an unchecked conversion, again to avoid the need + for some variable-sized temporaries. If valid, this conversion is + very likely purely technical and without real effects. */ + if (ecode == ARRAY_TYPE + && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == ARRAY_TYPE + && !TREE_CONSTANT (TYPE_SIZE (etype)) + && !TREE_CONSTANT (TYPE_SIZE (type))) + return unchecked_convert (type, + convert (TREE_TYPE (TYPE_FIELDS (type)), + expr), + false); + + tree t = convert (TREE_TYPE (TYPE_FIELDS (type)), expr); + + /* If converting to the inner type has already created a CONSTRUCTOR with + the right size, then reuse it instead of creating another one. This + can happen for the padding type built to overalign local variables. */ + if (TREE_CODE (t) == VIEW_CONVERT_EXPR + && TREE_CODE (TREE_OPERAND (t, 0)) == CONSTRUCTOR + && TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (TREE_OPERAND (t, 0)))) + && tree_int_cst_equal (TYPE_SIZE (type), + TYPE_SIZE (TREE_TYPE (TREE_OPERAND (t, 0))))) + return build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (t, 0)); + + vec<constructor_elt, va_gc> *v; + vec_alloc (v, 1); + CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (type), t); + return gnat_build_constructor (type, v); + } + + /* If the input type has padding, remove it and convert to the output type. + The conditions ordering is arranged to ensure that the output type is not + a padding type here, as it is not clear whether the conversion would + always be correct if this was to happen. */ + else if (ecode == RECORD_TYPE && TYPE_PADDING_P (etype)) + { + tree unpadded; + + /* If we have just converted to this padded type, just get the + inner expression. */ + if (TREE_CODE (expr) == CONSTRUCTOR) + unpadded = CONSTRUCTOR_ELT (expr, 0)->value; + + /* Otherwise, build an explicit component reference. */ + else + unpadded = build_component_ref (expr, TYPE_FIELDS (etype), false); + + return convert (type, unpadded); + } + + /* If the input is a biased type, convert first to the base type and add + the bias. Note that the bias must go through a full conversion to the + base type, lest it is itself a biased value; this happens for subtypes + of biased types. */ + if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype)) + return convert (type, fold_build2 (PLUS_EXPR, TREE_TYPE (etype), + fold_convert (TREE_TYPE (etype), expr), + convert (TREE_TYPE (etype), + TYPE_MIN_VALUE (etype)))); + + /* If the input is a justified modular type, we need to extract the actual + object before converting it to any other type with the exceptions of an + unconstrained array or of a mere type variant. It is useful to avoid the + extraction and conversion in the type variant case because it could end + up replacing a VAR_DECL expr by a constructor and we might be about the + take the address of the result. */ + if (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype) + && code != UNCONSTRAINED_ARRAY_TYPE + && TYPE_MAIN_VARIANT (type) != TYPE_MAIN_VARIANT (etype)) + return + convert (type, build_component_ref (expr, TYPE_FIELDS (etype), false)); + + /* If converting to a type that contains a template, convert to the data + type and then build the template. */ + if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type)) + { + tree obj_type = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type))); + vec<constructor_elt, va_gc> *v; + vec_alloc (v, 2); + + /* If the source already has a template, get a reference to the + associated array only, as we are going to rebuild a template + for the target type anyway. */ + expr = maybe_unconstrained_array (expr); + + CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (type), + build_template (TREE_TYPE (TYPE_FIELDS (type)), + obj_type, NULL_TREE)); + if (expr) + CONSTRUCTOR_APPEND_ELT (v, DECL_CHAIN (TYPE_FIELDS (type)), + convert (obj_type, expr)); + return gnat_build_constructor (type, v); + } + + /* There are some cases of expressions that we process specially. */ + switch (TREE_CODE (expr)) + { + case ERROR_MARK: + return expr; + + case NULL_EXPR: + /* Just set its type here. For TRANSFORM_EXPR, we will do the actual + conversion in gnat_expand_expr. NULL_EXPR does not represent + and actual value, so no conversion is needed. */ + expr = copy_node (expr); + TREE_TYPE (expr) = type; + return expr; + + case STRING_CST: + /* If we are converting a STRING_CST to another constrained array type, + just make a new one in the proper type. */ + if (code == ecode && AGGREGATE_TYPE_P (etype) + && !(TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST + && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)) + { + expr = copy_node (expr); + TREE_TYPE (expr) = type; + return expr; + } + break; + + case VECTOR_CST: + /* If we are converting a VECTOR_CST to a mere type variant, just make + a new one in the proper type. */ + if (code == ecode && gnat_types_compatible_p (type, etype)) + { + expr = copy_node (expr); + TREE_TYPE (expr) = type; + return expr; + } + break; + + case CONSTRUCTOR: + /* If we are converting a CONSTRUCTOR to a mere type variant, or to + another padding type around the same type, just make a new one in + the proper type. */ + if (code == ecode + && (gnat_types_compatible_p (type, etype) + || (code == RECORD_TYPE + && TYPE_PADDING_P (type) && TYPE_PADDING_P (etype) + && TREE_TYPE (TYPE_FIELDS (type)) + == TREE_TYPE (TYPE_FIELDS (etype))))) + { + expr = copy_node (expr); + TREE_TYPE (expr) = type; + CONSTRUCTOR_ELTS (expr) = vec_safe_copy (CONSTRUCTOR_ELTS (expr)); + return expr; + } + + /* Likewise for a conversion between original and packable version, or + conversion between types of the same size and with the same list of + fields, but we have to work harder to preserve type consistency. */ + if (code == ecode + && code == RECORD_TYPE + && (TYPE_NAME (type) == TYPE_NAME (etype) + || tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (etype)))) + + { + vec<constructor_elt, va_gc> *e = CONSTRUCTOR_ELTS (expr); + unsigned HOST_WIDE_INT len = vec_safe_length (e); + vec<constructor_elt, va_gc> *v; + vec_alloc (v, len); + tree efield = TYPE_FIELDS (etype), field = TYPE_FIELDS (type); + unsigned HOST_WIDE_INT idx; + tree index, value; + + /* Whether we need to clear TREE_CONSTANT et al. on the output + constructor when we convert in place. */ + bool clear_constant = false; + + FOR_EACH_CONSTRUCTOR_ELT(e, idx, index, value) + { + /* Skip the missing fields in the CONSTRUCTOR. */ + while (efield && field && !SAME_FIELD_P (efield, index)) + { + efield = DECL_CHAIN (efield); + field = DECL_CHAIN (field); + } + /* The field must be the same. */ + if (!(efield && field && SAME_FIELD_P (efield, field))) + break; + constructor_elt elt + = {field, convert (TREE_TYPE (field), value)}; + v->quick_push (elt); + + /* If packing has made this field a bitfield and the input + value couldn't be emitted statically any more, we need to + clear TREE_CONSTANT on our output. */ + if (!clear_constant + && TREE_CONSTANT (expr) + && !CONSTRUCTOR_BITFIELD_P (efield) + && CONSTRUCTOR_BITFIELD_P (field) + && !initializer_constant_valid_for_bitfield_p (value)) + clear_constant = true; + + efield = DECL_CHAIN (efield); + field = DECL_CHAIN (field); + } + + /* If we have been able to match and convert all the input fields + to their output type, convert in place now. We'll fallback to a + view conversion downstream otherwise. */ + if (idx == len) + { + expr = copy_node (expr); + TREE_TYPE (expr) = type; + CONSTRUCTOR_ELTS (expr) = v; + if (clear_constant) + TREE_CONSTANT (expr) = TREE_STATIC (expr) = 0; + return expr; + } + } + + /* Likewise for a conversion between array type and vector type with a + compatible representative array. */ + else if (code == VECTOR_TYPE + && ecode == ARRAY_TYPE + && gnat_types_compatible_p (TYPE_REPRESENTATIVE_ARRAY (type), + etype)) + { + vec<constructor_elt, va_gc> *e = CONSTRUCTOR_ELTS (expr); + unsigned HOST_WIDE_INT len = vec_safe_length (e); + vec<constructor_elt, va_gc> *v; + unsigned HOST_WIDE_INT ix; + tree value; + + /* Build a VECTOR_CST from a *constant* array constructor. */ + if (TREE_CONSTANT (expr)) + { + bool constant_p = true; + + /* Iterate through elements and check if all constructor + elements are *_CSTs. */ + FOR_EACH_CONSTRUCTOR_VALUE (e, ix, value) + if (!CONSTANT_CLASS_P (value)) + { + constant_p = false; + break; + } + + if (constant_p) + return build_vector_from_ctor (type, + CONSTRUCTOR_ELTS (expr)); + } + + /* Otherwise, build a regular vector constructor. */ + vec_alloc (v, len); + FOR_EACH_CONSTRUCTOR_VALUE (e, ix, value) + { + constructor_elt elt = {NULL_TREE, value}; + v->quick_push (elt); + } + expr = copy_node (expr); + TREE_TYPE (expr) = type; + CONSTRUCTOR_ELTS (expr) = v; + return expr; + } + break; + + case UNCONSTRAINED_ARRAY_REF: + /* First retrieve the underlying array. */ + expr = maybe_unconstrained_array (expr); + etype = TREE_TYPE (expr); + ecode = TREE_CODE (etype); + break; + + case VIEW_CONVERT_EXPR: + { + /* GCC 4.x is very sensitive to type consistency overall, and view + conversions thus are very frequent. Even though just "convert"ing + the inner operand to the output type is fine in most cases, it + might expose unexpected input/output type mismatches in special + circumstances so we avoid such recursive calls when we can. */ + tree op0 = TREE_OPERAND (expr, 0); + + /* If we are converting back to the original type, we can just + lift the input conversion. This is a common occurrence with + switches back-and-forth amongst type variants. */ + if (type == TREE_TYPE (op0)) + return op0; + + /* Otherwise, if we're converting between two aggregate or vector + types, we might be allowed to substitute the VIEW_CONVERT_EXPR + target type in place or to just convert the inner expression. */ + if ((AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype)) + || (VECTOR_TYPE_P (type) && VECTOR_TYPE_P (etype))) + { + /* If we are converting between mere variants, we can just + substitute the VIEW_CONVERT_EXPR in place. */ + if (gnat_types_compatible_p (type, etype)) + return build1 (VIEW_CONVERT_EXPR, type, op0); + + /* Otherwise, we may just bypass the input view conversion unless + one of the types is a fat pointer, which is handled by + specialized code below which relies on exact type matching. */ + else if (!TYPE_IS_FAT_POINTER_P (type) + && !TYPE_IS_FAT_POINTER_P (etype)) + return convert (type, op0); + } + + break; + } + + default: + break; + } + + /* Check for converting to a pointer to an unconstrained array. */ + if (TYPE_IS_FAT_POINTER_P (type) && !TYPE_IS_FAT_POINTER_P (etype)) + return convert_to_fat_pointer (type, expr); + + /* If we are converting between two aggregate or vector types that are mere + variants, just make a VIEW_CONVERT_EXPR. Likewise when we are converting + to a vector type from its representative array type. */ + else if ((code == ecode + && (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) + && gnat_types_compatible_p (type, etype)) + || (code == VECTOR_TYPE + && ecode == ARRAY_TYPE + && gnat_types_compatible_p (TYPE_REPRESENTATIVE_ARRAY (type), + etype))) + return build1 (VIEW_CONVERT_EXPR, type, expr); + + /* If we are converting between tagged types, try to upcast properly. */ + else if (ecode == RECORD_TYPE && code == RECORD_TYPE + && TYPE_ALIGN_OK (etype) && TYPE_ALIGN_OK (type)) + { + tree child_etype = etype; + do { + tree field = TYPE_FIELDS (child_etype); + if (DECL_NAME (field) == parent_name_id && TREE_TYPE (field) == type) + return build_component_ref (expr, field, false); + child_etype = TREE_TYPE (field); + } while (TREE_CODE (child_etype) == RECORD_TYPE); + } + + /* If we are converting from a smaller form of record type back to it, just + make a VIEW_CONVERT_EXPR. But first pad the expression to have the same + size on both sides. */ + else if (ecode == RECORD_TYPE && code == RECORD_TYPE + && smaller_form_type_p (etype, type)) + { + expr = convert (maybe_pad_type (etype, TYPE_SIZE (type), 0, Empty, + false, false, false, true), + expr); + return build1 (VIEW_CONVERT_EXPR, type, expr); + } + + /* In all other cases of related types, make a NOP_EXPR. */ + else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype)) + return fold_convert (type, expr); + + switch (code) + { + case VOID_TYPE: + return fold_build1 (CONVERT_EXPR, type, expr); + + case INTEGER_TYPE: + if (TYPE_HAS_ACTUAL_BOUNDS_P (type) + && (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE + || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype)))) + return unchecked_convert (type, expr, false); + + /* If the output is a biased type, convert first to the base type and + subtract the bias. Note that the bias itself must go through a full + conversion to the base type, lest it is a biased value; this happens + for subtypes of biased types. */ + if (TYPE_BIASED_REPRESENTATION_P (type)) + return fold_convert (type, + fold_build2 (MINUS_EXPR, TREE_TYPE (type), + convert (TREE_TYPE (type), expr), + convert (TREE_TYPE (type), + TYPE_MIN_VALUE (type)))); + + /* ... fall through ... */ + + case ENUMERAL_TYPE: + case BOOLEAN_TYPE: + /* If we are converting an additive expression to an integer type + with lower precision, be wary of the optimization that can be + applied by convert_to_integer. There are 2 problematic cases: + - if the first operand was originally of a biased type, + because we could be recursively called to convert it + to an intermediate type and thus rematerialize the + additive operator endlessly, + - if the expression contains a placeholder, because an + intermediate conversion that changes the sign could + be inserted and thus introduce an artificial overflow + at compile time when the placeholder is substituted. */ + if (code == INTEGER_TYPE + && ecode == INTEGER_TYPE + && TYPE_PRECISION (type) < TYPE_PRECISION (etype) + && (TREE_CODE (expr) == PLUS_EXPR || TREE_CODE (expr) == MINUS_EXPR)) + { + tree op0 = get_unwidened (TREE_OPERAND (expr, 0), type); + + if ((TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (TREE_TYPE (op0))) + || CONTAINS_PLACEHOLDER_P (expr)) + return build1 (NOP_EXPR, type, expr); + } + + return fold (convert_to_integer (type, expr)); + + case POINTER_TYPE: + case REFERENCE_TYPE: + /* If converting between two thin pointers, adjust if needed to account + for differing offsets from the base pointer, depending on whether + there is a TYPE_UNCONSTRAINED_ARRAY attached to the record type. */ + if (TYPE_IS_THIN_POINTER_P (etype) && TYPE_IS_THIN_POINTER_P (type)) + { + tree etype_pos + = TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (etype)) + ? byte_position (DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (etype)))) + : size_zero_node; + tree type_pos + = TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)) + ? byte_position (DECL_CHAIN (TYPE_FIELDS (TREE_TYPE (type)))) + : size_zero_node; + tree byte_diff = size_diffop (type_pos, etype_pos); + + expr = build1 (NOP_EXPR, type, expr); + if (integer_zerop (byte_diff)) + return expr; + + return build_binary_op (POINTER_PLUS_EXPR, type, expr, + fold_convert (sizetype, byte_diff)); + } + + /* If converting fat pointer to normal or thin pointer, get the pointer + to the array and then convert it. */ + if (TYPE_IS_FAT_POINTER_P (etype)) + expr = build_component_ref (expr, TYPE_FIELDS (etype), false); + + return fold (convert_to_pointer (type, expr)); + + case REAL_TYPE: + return fold (convert_to_real (type, expr)); + + case RECORD_TYPE: + if (TYPE_JUSTIFIED_MODULAR_P (type) && !AGGREGATE_TYPE_P (etype)) + { + vec<constructor_elt, va_gc> *v; + vec_alloc (v, 1); + + CONSTRUCTOR_APPEND_ELT (v, TYPE_FIELDS (type), + convert (TREE_TYPE (TYPE_FIELDS (type)), + expr)); + return gnat_build_constructor (type, v); + } + + /* ... fall through ... */ + + case ARRAY_TYPE: + /* In these cases, assume the front-end has validated the conversion. + If the conversion is valid, it will be a bit-wise conversion, so + it can be viewed as an unchecked conversion. */ + return unchecked_convert (type, expr, false); + + case UNION_TYPE: + /* This is a either a conversion between a tagged type and some + subtype, which we have to mark as a UNION_TYPE because of + overlapping fields or a conversion of an Unchecked_Union. */ + return unchecked_convert (type, expr, false); + + case UNCONSTRAINED_ARRAY_TYPE: + /* If the input is a VECTOR_TYPE, convert to the representative + array type first. */ + if (ecode == VECTOR_TYPE) + { + expr = convert (TYPE_REPRESENTATIVE_ARRAY (etype), expr); + etype = TREE_TYPE (expr); + ecode = TREE_CODE (etype); + } + + /* If EXPR is a constrained array, take its address, convert it to a + fat pointer, and then dereference it. Likewise if EXPR is a + record containing both a template and a constrained array. + Note that a record representing a justified modular type + always represents a packed constrained array. */ + if (ecode == ARRAY_TYPE + || (ecode == INTEGER_TYPE && TYPE_HAS_ACTUAL_BOUNDS_P (etype)) + || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype)) + || (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype))) + return + build_unary_op + (INDIRECT_REF, NULL_TREE, + convert_to_fat_pointer (TREE_TYPE (type), + build_unary_op (ADDR_EXPR, + NULL_TREE, expr))); + + /* Do something very similar for converting one unconstrained + array to another. */ + else if (ecode == UNCONSTRAINED_ARRAY_TYPE) + return + build_unary_op (INDIRECT_REF, NULL_TREE, + convert (TREE_TYPE (type), + build_unary_op (ADDR_EXPR, + NULL_TREE, expr))); + else + gcc_unreachable (); + + case COMPLEX_TYPE: + return fold (convert_to_complex (type, expr)); + + default: + gcc_unreachable (); + } +} + +/* Create an expression whose value is that of EXPR converted to the common + index type, which is sizetype. EXPR is supposed to be in the base type + of the GNAT index type. Calling it is equivalent to doing + + convert (sizetype, expr) + + but we try to distribute the type conversion with the knowledge that EXPR + cannot overflow in its type. This is a best-effort approach and we fall + back to the above expression as soon as difficulties are encountered. + + This is necessary to overcome issues that arise when the GNAT base index + type and the GCC common index type (sizetype) don't have the same size, + which is quite frequent on 64-bit architectures. In this case, and if + the GNAT base index type is signed but the iteration type of the loop has + been forced to unsigned, the loop scalar evolution engine cannot compute + a simple evolution for the general induction variables associated with the + array indices, because it will preserve the wrap-around semantics in the + unsigned type of their "inner" part. As a result, many loop optimizations + are blocked. + + The solution is to use a special (basic) induction variable that is at + least as large as sizetype, and to express the aforementioned general + induction variables in terms of this induction variable, eliminating + the problematic intermediate truncation to the GNAT base index type. + This is possible as long as the original expression doesn't overflow + and if the middle-end hasn't introduced artificial overflows in the + course of the various simplification it can make to the expression. */ + +tree +convert_to_index_type (tree expr) +{ + enum tree_code code = TREE_CODE (expr); + tree type = TREE_TYPE (expr); + + /* If the type is unsigned, overflow is allowed so we cannot be sure that + EXPR doesn't overflow. Keep it simple if optimization is disabled. */ + if (TYPE_UNSIGNED (type) || !optimize) + return convert (sizetype, expr); + + switch (code) + { + case VAR_DECL: + /* The main effect of the function: replace a loop parameter with its + associated special induction variable. */ + if (DECL_LOOP_PARM_P (expr) && DECL_INDUCTION_VAR (expr)) + expr = DECL_INDUCTION_VAR (expr); + break; + + CASE_CONVERT: + { + tree otype = TREE_TYPE (TREE_OPERAND (expr, 0)); + /* Bail out as soon as we suspect some sort of type frobbing. */ + if (TYPE_PRECISION (type) != TYPE_PRECISION (otype) + || TYPE_UNSIGNED (type) != TYPE_UNSIGNED (otype)) + break; + } + + /* ... fall through ... */ + + case NON_LVALUE_EXPR: + return fold_build1 (code, sizetype, + convert_to_index_type (TREE_OPERAND (expr, 0))); + + case PLUS_EXPR: + case MINUS_EXPR: + case MULT_EXPR: + return fold_build2 (code, sizetype, + convert_to_index_type (TREE_OPERAND (expr, 0)), + convert_to_index_type (TREE_OPERAND (expr, 1))); + + case COMPOUND_EXPR: + return fold_build2 (code, sizetype, TREE_OPERAND (expr, 0), + convert_to_index_type (TREE_OPERAND (expr, 1))); + + case COND_EXPR: + return fold_build3 (code, sizetype, TREE_OPERAND (expr, 0), + convert_to_index_type (TREE_OPERAND (expr, 1)), + convert_to_index_type (TREE_OPERAND (expr, 2))); + + default: + break; + } + + return convert (sizetype, expr); +} + +/* Remove all conversions that are done in EXP. This includes converting + from a padded type or to a justified modular type. If TRUE_ADDRESS + is true, always return the address of the containing object even if + the address is not bit-aligned. */ + +tree +remove_conversions (tree exp, bool true_address) +{ + switch (TREE_CODE (exp)) + { + case CONSTRUCTOR: + if (true_address + && TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (TREE_TYPE (exp))) + return + remove_conversions (CONSTRUCTOR_ELT (exp, 0)->value, true); + break; + + case COMPONENT_REF: + if (TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (exp, 0)))) + return remove_conversions (TREE_OPERAND (exp, 0), true_address); + break; + + CASE_CONVERT: + case VIEW_CONVERT_EXPR: + case NON_LVALUE_EXPR: + return remove_conversions (TREE_OPERAND (exp, 0), true_address); + + default: + break; + } + + return exp; +} + +/* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that + refers to the underlying array. If it has TYPE_CONTAINS_TEMPLATE_P, + likewise return an expression pointing to the underlying array. */ + +tree +maybe_unconstrained_array (tree exp) +{ + enum tree_code code = TREE_CODE (exp); + tree type = TREE_TYPE (exp); + + switch (TREE_CODE (type)) + { + case UNCONSTRAINED_ARRAY_TYPE: + if (code == UNCONSTRAINED_ARRAY_REF) + { + const bool read_only = TREE_READONLY (exp); + const bool no_trap = TREE_THIS_NOTRAP (exp); + + exp = TREE_OPERAND (exp, 0); + type = TREE_TYPE (exp); + + if (TREE_CODE (exp) == COND_EXPR) + { + tree op1 + = build_unary_op (INDIRECT_REF, NULL_TREE, + build_component_ref (TREE_OPERAND (exp, 1), + TYPE_FIELDS (type), + false)); + tree op2 + = build_unary_op (INDIRECT_REF, NULL_TREE, + build_component_ref (TREE_OPERAND (exp, 2), + TYPE_FIELDS (type), + false)); + + exp = build3 (COND_EXPR, + TREE_TYPE (TREE_TYPE (TYPE_FIELDS (type))), + TREE_OPERAND (exp, 0), op1, op2); + } + else + { + exp = build_unary_op (INDIRECT_REF, NULL_TREE, + build_component_ref (exp, + TYPE_FIELDS (type), + false)); + TREE_READONLY (exp) = read_only; + TREE_THIS_NOTRAP (exp) = no_trap; + } + } + + else if (code == NULL_EXPR) + exp = build1 (NULL_EXPR, + TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type)))), + TREE_OPERAND (exp, 0)); + break; + + case RECORD_TYPE: + /* If this is a padded type and it contains a template, convert to the + unpadded type first. */ + if (TYPE_PADDING_P (type) + && TREE_CODE (TREE_TYPE (TYPE_FIELDS (type))) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (TYPE_FIELDS (type)))) + { + exp = convert (TREE_TYPE (TYPE_FIELDS (type)), exp); + code = TREE_CODE (exp); + type = TREE_TYPE (exp); + } + + if (TYPE_CONTAINS_TEMPLATE_P (type)) + { + /* If the array initializer is a box, return NULL_TREE. */ + if (code == CONSTRUCTOR && CONSTRUCTOR_NELTS (exp) < 2) + return NULL_TREE; + + exp = build_component_ref (exp, DECL_CHAIN (TYPE_FIELDS (type)), + false); + type = TREE_TYPE (exp); + + /* If the array type is padded, convert to the unpadded type. */ + if (TYPE_IS_PADDING_P (type)) + exp = convert (TREE_TYPE (TYPE_FIELDS (type)), exp); + } + break; + + default: + break; + } + + return exp; +} + +/* Return true if EXPR is an expression that can be folded as an operand + of a VIEW_CONVERT_EXPR. See ada-tree.h for a complete rationale. */ + +static bool +can_fold_for_view_convert_p (tree expr) +{ + tree t1, t2; + + /* The folder will fold NOP_EXPRs between integral types with the same + precision (in the middle-end's sense). We cannot allow it if the + types don't have the same precision in the Ada sense as well. */ + if (TREE_CODE (expr) != NOP_EXPR) + return true; + + t1 = TREE_TYPE (expr); + t2 = TREE_TYPE (TREE_OPERAND (expr, 0)); + + /* Defer to the folder for non-integral conversions. */ + if (!(INTEGRAL_TYPE_P (t1) && INTEGRAL_TYPE_P (t2))) + return true; + + /* Only fold conversions that preserve both precisions. */ + if (TYPE_PRECISION (t1) == TYPE_PRECISION (t2) + && operand_equal_p (rm_size (t1), rm_size (t2), 0)) + return true; + + return false; +} + +/* Return an expression that does an unchecked conversion of EXPR to TYPE. + If NOTRUNC_P is true, truncation operations should be suppressed. + + Special care is required with (source or target) integral types whose + precision is not equal to their size, to make sure we fetch or assign + the value bits whose location might depend on the endianness, e.g. + + Rmsize : constant := 8; + subtype Int is Integer range 0 .. 2 ** Rmsize - 1; + + type Bit_Array is array (1 .. Rmsize) of Boolean; + pragma Pack (Bit_Array); + + function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array); + + Value : Int := 2#1000_0001#; + Vbits : Bit_Array := To_Bit_Array (Value); + + we expect the 8 bits at Vbits'Address to always contain Value, while + their original location depends on the endianness, at Value'Address + on a little-endian architecture but not on a big-endian one. + + One pitfall is that we cannot use TYPE_UNSIGNED directly to decide how + the bits between the precision and the size are filled, because of the + trick used in the E_Signed_Integer_Subtype case of gnat_to_gnu_entity. + So we use the special predicate type_unsigned_for_rm above. */ + +tree +unchecked_convert (tree type, tree expr, bool notrunc_p) +{ + tree etype = TREE_TYPE (expr); + enum tree_code ecode = TREE_CODE (etype); + enum tree_code code = TREE_CODE (type); + tree tem; + int c; + + /* If the expression is already of the right type, we are done. */ + if (etype == type) + return expr; + + /* If both types are integral just do a normal conversion. + Likewise for a conversion to an unconstrained array. */ + if (((INTEGRAL_TYPE_P (type) + || (POINTER_TYPE_P (type) && !TYPE_IS_THIN_POINTER_P (type)) + || (code == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (type))) + && (INTEGRAL_TYPE_P (etype) + || (POINTER_TYPE_P (etype) && !TYPE_IS_THIN_POINTER_P (etype)) + || (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)))) + || code == UNCONSTRAINED_ARRAY_TYPE) + { + if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype)) + { + tree ntype = copy_type (etype); + TYPE_BIASED_REPRESENTATION_P (ntype) = 0; + TYPE_MAIN_VARIANT (ntype) = ntype; + expr = build1 (NOP_EXPR, ntype, expr); + } + + if (code == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (type)) + { + tree rtype = copy_type (type); + TYPE_BIASED_REPRESENTATION_P (rtype) = 0; + TYPE_MAIN_VARIANT (rtype) = rtype; + expr = convert (rtype, expr); + expr = build1 (NOP_EXPR, type, expr); + } + else + expr = convert (type, expr); + } + + /* If we are converting to an integral type whose precision is not equal + to its size, first unchecked convert to a record type that contains a + field of the given precision. Then extract the result from the field. + + There is a subtlety if the source type is an aggregate type with reverse + storage order because its representation is not contiguous in the native + storage order, i.e. a direct unchecked conversion to an integral type + with N bits of precision cannot read the first N bits of the aggregate + type. To overcome it, we do an unchecked conversion to an integral type + with reverse storage order and return the resulting value. This also + ensures that the result of the unchecked conversion doesn't depend on + the endianness of the target machine, but only on the storage order of + the aggregate type. + + Finally, for the sake of consistency, we do the unchecked conversion + to an integral type with reverse storage order as soon as the source + type is an aggregate type with reverse storage order, even if there + are no considerations of precision or size involved. */ + else if (INTEGRAL_TYPE_P (type) + && TYPE_RM_SIZE (type) + && (tree_int_cst_compare (TYPE_RM_SIZE (type), + TYPE_SIZE (type)) < 0 + || (AGGREGATE_TYPE_P (etype) + && TYPE_REVERSE_STORAGE_ORDER (etype)))) + { + tree rec_type = make_node (RECORD_TYPE); + unsigned HOST_WIDE_INT prec = TREE_INT_CST_LOW (TYPE_RM_SIZE (type)); + tree field_type, field; + + if (AGGREGATE_TYPE_P (etype)) + TYPE_REVERSE_STORAGE_ORDER (rec_type) + = TYPE_REVERSE_STORAGE_ORDER (etype); + + if (type_unsigned_for_rm (type)) + field_type = make_unsigned_type (prec); + else + field_type = make_signed_type (prec); + SET_TYPE_RM_SIZE (field_type, TYPE_RM_SIZE (type)); + + field = create_field_decl (get_identifier ("OBJ"), field_type, rec_type, + NULL_TREE, bitsize_zero_node, 1, 0); + + finish_record_type (rec_type, field, 1, false); + + expr = unchecked_convert (rec_type, expr, notrunc_p); + expr = build_component_ref (expr, field, false); + expr = fold_build1 (NOP_EXPR, type, expr); + } + + /* Similarly if we are converting from an integral type whose precision is + not equal to its size, first copy into a field of the given precision + and unchecked convert the record type. + + The same considerations as above apply if the target type is an aggregate + type with reverse storage order and we also proceed similarly. */ + else if (INTEGRAL_TYPE_P (etype) + && TYPE_RM_SIZE (etype) + && (tree_int_cst_compare (TYPE_RM_SIZE (etype), + TYPE_SIZE (etype)) < 0 + || (AGGREGATE_TYPE_P (type) + && TYPE_REVERSE_STORAGE_ORDER (type)))) + { + tree rec_type = make_node (RECORD_TYPE); + unsigned HOST_WIDE_INT prec = TREE_INT_CST_LOW (TYPE_RM_SIZE (etype)); + vec<constructor_elt, va_gc> *v; + vec_alloc (v, 1); + tree field_type, field; + + if (AGGREGATE_TYPE_P (type)) + TYPE_REVERSE_STORAGE_ORDER (rec_type) + = TYPE_REVERSE_STORAGE_ORDER (type); + + if (type_unsigned_for_rm (etype)) + field_type = make_unsigned_type (prec); + else + field_type = make_signed_type (prec); + SET_TYPE_RM_SIZE (field_type, TYPE_RM_SIZE (etype)); + + field = create_field_decl (get_identifier ("OBJ"), field_type, rec_type, + NULL_TREE, bitsize_zero_node, 1, 0); + + finish_record_type (rec_type, field, 1, false); + + expr = fold_build1 (NOP_EXPR, field_type, expr); + CONSTRUCTOR_APPEND_ELT (v, field, expr); + expr = gnat_build_constructor (rec_type, v); + expr = unchecked_convert (type, expr, notrunc_p); + } + + /* If we are converting from a scalar type to a type with a different size, + we need to pad to have the same size on both sides. + + ??? We cannot do it unconditionally because unchecked conversions are + used liberally by the front-end to implement polymorphism, e.g. in: + + S191s : constant ada__tags__addr_ptr := ada__tags__addr_ptr!(S190s); + return p___size__4 (p__object!(S191s.all)); + + so we skip all expressions that are references. */ + else if (!REFERENCE_CLASS_P (expr) + && !AGGREGATE_TYPE_P (etype) + && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST + && (c = tree_int_cst_compare (TYPE_SIZE (etype), TYPE_SIZE (type)))) + { + if (c < 0) + { + expr = convert (maybe_pad_type (etype, TYPE_SIZE (type), 0, Empty, + false, false, false, true), + expr); + expr = unchecked_convert (type, expr, notrunc_p); + } + else + { + tree rec_type = maybe_pad_type (type, TYPE_SIZE (etype), 0, Empty, + false, false, false, true); + expr = unchecked_convert (rec_type, expr, notrunc_p); + expr = build_component_ref (expr, TYPE_FIELDS (rec_type), false); + } + } + + /* We have a special case when we are converting between two unconstrained + array types. In that case, take the address, convert the fat pointer + types, and dereference. */ + else if (ecode == code && code == UNCONSTRAINED_ARRAY_TYPE) + expr = build_unary_op (INDIRECT_REF, NULL_TREE, + build1 (VIEW_CONVERT_EXPR, TREE_TYPE (type), + build_unary_op (ADDR_EXPR, NULL_TREE, + expr))); + + /* Another special case is when we are converting to a vector type from its + representative array type; this a regular conversion. */ + else if (code == VECTOR_TYPE + && ecode == ARRAY_TYPE + && gnat_types_compatible_p (TYPE_REPRESENTATIVE_ARRAY (type), + etype)) + expr = convert (type, expr); + + /* And, if the array type is not the representative, we try to build an + intermediate vector type of which the array type is the representative + and to do the unchecked conversion between the vector types, in order + to enable further simplifications in the middle-end. */ + else if (code == VECTOR_TYPE + && ecode == ARRAY_TYPE + && (tem = build_vector_type_for_array (etype, NULL_TREE))) + { + expr = convert (tem, expr); + return unchecked_convert (type, expr, notrunc_p); + } + + /* If we are converting a CONSTRUCTOR to a more aligned RECORD_TYPE, bump + the alignment of the CONSTRUCTOR to speed up the copy operation. */ + else if (TREE_CODE (expr) == CONSTRUCTOR + && code == RECORD_TYPE + && TYPE_ALIGN (etype) < TYPE_ALIGN (type)) + { + expr = convert (maybe_pad_type (etype, NULL_TREE, TYPE_ALIGN (type), + Empty, false, false, false, true), + expr); + return unchecked_convert (type, expr, notrunc_p); + } + + /* Otherwise, just build a VIEW_CONVERT_EXPR of the expression. */ + else + { + expr = maybe_unconstrained_array (expr); + etype = TREE_TYPE (expr); + ecode = TREE_CODE (etype); + if (can_fold_for_view_convert_p (expr)) + expr = fold_build1 (VIEW_CONVERT_EXPR, type, expr); + else + expr = build1 (VIEW_CONVERT_EXPR, type, expr); + } + + /* If the result is a non-biased integral type whose precision is not equal + to its size, sign- or zero-extend the result. But we need not do this + if the input is also an integral type and both are unsigned or both are + signed and have the same precision. */ + if (!notrunc_p + && INTEGRAL_TYPE_P (type) + && !(code == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (type)) + && TYPE_RM_SIZE (type) + && tree_int_cst_compare (TYPE_RM_SIZE (type), TYPE_SIZE (type)) < 0 + && !(INTEGRAL_TYPE_P (etype) + && type_unsigned_for_rm (type) == type_unsigned_for_rm (etype) + && (type_unsigned_for_rm (type) + || tree_int_cst_compare (TYPE_RM_SIZE (type), + TYPE_RM_SIZE (etype) + ? TYPE_RM_SIZE (etype) + : TYPE_SIZE (etype)) == 0))) + { + if (integer_zerop (TYPE_RM_SIZE (type))) + expr = build_int_cst (type, 0); + else + { + tree base_type + = gnat_type_for_size (TREE_INT_CST_LOW (TYPE_SIZE (type)), + type_unsigned_for_rm (type)); + tree shift_expr + = convert (base_type, + size_binop (MINUS_EXPR, + TYPE_SIZE (type), TYPE_RM_SIZE (type))); + expr + = convert (type, + build_binary_op (RSHIFT_EXPR, base_type, + build_binary_op (LSHIFT_EXPR, base_type, + convert (base_type, + expr), + shift_expr), + shift_expr)); + } + } + + /* An unchecked conversion should never raise Constraint_Error. The code + below assumes that GCC's conversion routines overflow the same way that + the underlying hardware does. This is probably true. In the rare case + when it is false, we can rely on the fact that such conversions are + erroneous anyway. */ + if (TREE_CODE (expr) == INTEGER_CST) + TREE_OVERFLOW (expr) = 0; + + /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR, + show no longer constant. */ + if (TREE_CODE (expr) == VIEW_CONVERT_EXPR + && !operand_equal_p (TYPE_SIZE_UNIT (type), TYPE_SIZE_UNIT (etype), + OEP_ONLY_CONST)) + TREE_CONSTANT (expr) = 0; + + return expr; +} + +/* Return the appropriate GCC tree code for the specified GNAT_TYPE, + the latter being a record type as predicated by Is_Record_Type. */ + +enum tree_code +tree_code_for_record_type (Entity_Id gnat_type) +{ + Node_Id component_list, component; + + /* Return UNION_TYPE if it's an Unchecked_Union whose non-discriminant + fields are all in the variant part. Otherwise, return RECORD_TYPE. */ + if (!Is_Unchecked_Union (gnat_type)) + return RECORD_TYPE; + + gnat_type = Implementation_Base_Type (gnat_type); + component_list + = Component_List (Type_Definition (Declaration_Node (gnat_type))); + + for (component = First_Non_Pragma (Component_Items (component_list)); + Present (component); + component = Next_Non_Pragma (component)) + if (Ekind (Defining_Entity (component)) == E_Component) + return RECORD_TYPE; + + return UNION_TYPE; +} + +/* Return true if GNAT_TYPE is a "double" floating-point type, i.e. whose + size is equal to 64 bits, or an array of such a type. Set ALIGN_CLAUSE + according to the presence of an alignment clause on the type or, if it + is an array, on the component type. */ + +bool +is_double_float_or_array (Entity_Id gnat_type, bool *align_clause) +{ + gnat_type = Underlying_Type (gnat_type); + + *align_clause = Present (Alignment_Clause (gnat_type)); + + if (Is_Array_Type (gnat_type)) + { + gnat_type = Underlying_Type (Component_Type (gnat_type)); + if (Present (Alignment_Clause (gnat_type))) + *align_clause = true; + } + + if (!Is_Floating_Point_Type (gnat_type)) + return false; + + if (UI_To_Int (Esize (gnat_type)) != 64) + return false; + + return true; +} + +/* Return true if GNAT_TYPE is a "double" or larger scalar type, i.e. whose + size is greater or equal to 64 bits, or an array of such a type. Set + ALIGN_CLAUSE according to the presence of an alignment clause on the + type or, if it is an array, on the component type. */ + +bool +is_double_scalar_or_array (Entity_Id gnat_type, bool *align_clause) +{ + gnat_type = Underlying_Type (gnat_type); + + *align_clause = Present (Alignment_Clause (gnat_type)); + + if (Is_Array_Type (gnat_type)) + { + gnat_type = Underlying_Type (Component_Type (gnat_type)); + if (Present (Alignment_Clause (gnat_type))) + *align_clause = true; + } + + if (!Is_Scalar_Type (gnat_type)) + return false; + + if (UI_To_Int (Esize (gnat_type)) < 64) + return false; + + return true; +} + +/* Return true if GNU_TYPE is suitable as the type of a non-aliased + component of an aggregate type. */ + +bool +type_for_nonaliased_component_p (tree gnu_type) +{ + /* If the type is passed by reference, we may have pointers to the + component so it cannot be made non-aliased. */ + if (must_pass_by_ref (gnu_type) || default_pass_by_ref (gnu_type)) + return false; + + /* We used to say that any component of aggregate type is aliased + because the front-end may take 'Reference of it. The front-end + has been enhanced in the meantime so as to use a renaming instead + in most cases, but the back-end can probably take the address of + such a component too so we go for the conservative stance. + + For instance, we might need the address of any array type, even + if normally passed by copy, to construct a fat pointer if the + component is used as an actual for an unconstrained formal. + + Likewise for record types: even if a specific record subtype is + passed by copy, the parent type might be passed by ref (e.g. if + it's of variable size) and we might take the address of a child + component to pass to a parent formal. We have no way to check + for such conditions here. */ + if (AGGREGATE_TYPE_P (gnu_type)) + return false; + + return true; +} + +/* Return true if TYPE is a smaller form of ORIG_TYPE. */ + +bool +smaller_form_type_p (tree type, tree orig_type) +{ + tree size, osize; + + /* We're not interested in variants here. */ + if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig_type)) + return false; + + /* Like a variant, a packable version keeps the original TYPE_NAME. */ + if (TYPE_NAME (type) != TYPE_NAME (orig_type)) + return false; + + size = TYPE_SIZE (type); + osize = TYPE_SIZE (orig_type); + + if (!(TREE_CODE (size) == INTEGER_CST && TREE_CODE (osize) == INTEGER_CST)) + return false; + + return tree_int_cst_lt (size, osize) != 0; +} + +/* Return whether EXPR, which is the renamed object in an object renaming + declaration, can be materialized as a reference (with a REFERENCE_TYPE). + This should be synchronized with Exp_Dbug.Debug_Renaming_Declaration. */ + +bool +can_materialize_object_renaming_p (Node_Id expr) +{ + while (true) + { + expr = Original_Node (expr); + + switch Nkind (expr) + { + case N_Identifier: + case N_Expanded_Name: + if (!Present (Renamed_Object (Entity (expr)))) + return true; + expr = Renamed_Object (Entity (expr)); + break; + + case N_Selected_Component: + { + if (Is_Packed (Underlying_Type (Etype (Prefix (expr))))) + return false; + + const Uint bitpos + = Normalized_First_Bit (Entity (Selector_Name (expr))); + if (!UI_Is_In_Int_Range (bitpos) + || (bitpos != UI_No_Uint && bitpos != UI_From_Int (0))) + return false; + + expr = Prefix (expr); + break; + } + + case N_Indexed_Component: + case N_Slice: + { + const Entity_Id t = Underlying_Type (Etype (Prefix (expr))); + + if (Is_Array_Type (t) && Present (Packed_Array_Impl_Type (t))) + return false; + + expr = Prefix (expr); + break; + } + + case N_Explicit_Dereference: + expr = Prefix (expr); + break; + + default: + return true; + }; + } +} + +/* Perform final processing on global declarations. */ + +static GTY (()) tree dummy_global; + +void +gnat_write_global_declarations (void) +{ + unsigned int i; + tree iter; + + /* If we have declared types as used at the global level, insert them in + the global hash table. We use a dummy variable for this purpose, but + we need to build it unconditionally to avoid -fcompare-debug issues. */ + if (first_global_object_name) + { + struct varpool_node *node; + char *label; + + ASM_FORMAT_PRIVATE_NAME (label, first_global_object_name, 0); + dummy_global + = build_decl (BUILTINS_LOCATION, VAR_DECL, get_identifier (label), + void_type_node); + DECL_HARD_REGISTER (dummy_global) = 1; + TREE_STATIC (dummy_global) = 1; + node = varpool_node::get_create (dummy_global); + node->definition = 1; + node->force_output = 1; + + if (types_used_by_cur_var_decl) + while (!types_used_by_cur_var_decl->is_empty ()) + { + tree t = types_used_by_cur_var_decl->pop (); + types_used_by_var_decl_insert (t, dummy_global); + } + } + + /* Output debug information for all global type declarations first. This + ensures that global types whose compilation hasn't been finalized yet, + for example pointers to Taft amendment types, have their compilation + finalized in the right context. */ + FOR_EACH_VEC_SAFE_ELT (global_decls, i, iter) + if (TREE_CODE (iter) == TYPE_DECL && !DECL_IGNORED_P (iter)) + debug_hooks->type_decl (iter, false); + + /* Output imported functions. */ + FOR_EACH_VEC_SAFE_ELT (global_decls, i, iter) + if (TREE_CODE (iter) == FUNCTION_DECL + && DECL_EXTERNAL (iter) + && DECL_INITIAL (iter) == NULL + && !DECL_IGNORED_P (iter) + && DECL_FUNCTION_IS_DEF (iter)) + debug_hooks->early_global_decl (iter); + + /* Then output the global variables. We need to do that after the debug + information for global types is emitted so that they are finalized. Skip + external global variables, unless we need to emit debug info for them: + this is useful for imported variables, for instance. */ + FOR_EACH_VEC_SAFE_ELT (global_decls, i, iter) + if (TREE_CODE (iter) == VAR_DECL + && (!DECL_EXTERNAL (iter) || !DECL_IGNORED_P (iter))) + rest_of_decl_compilation (iter, true, 0); + + /* Output the imported modules/declarations. In GNAT, these are only + materializing subprogram. */ + FOR_EACH_VEC_SAFE_ELT (global_decls, i, iter) + if (TREE_CODE (iter) == IMPORTED_DECL && !DECL_IGNORED_P (iter)) + debug_hooks->imported_module_or_decl (iter, DECL_NAME (iter), + DECL_CONTEXT (iter), false, false); +} + +/* ************************************************************************ + * * GCC builtins support * + * ************************************************************************ */ + +/* The general scheme is fairly simple: + + For each builtin function/type to be declared, gnat_install_builtins calls + internal facilities which eventually get to gnat_pushdecl, which in turn + tracks the so declared builtin function decls in the 'builtin_decls' global + datastructure. When an Intrinsic subprogram declaration is processed, we + search this global datastructure to retrieve the associated BUILT_IN DECL + node. */ + +/* Search the chain of currently available builtin declarations for a node + corresponding to function NAME (an IDENTIFIER_NODE). Return the first node + found, if any, or NULL_TREE otherwise. */ +tree +builtin_decl_for (tree name) +{ + unsigned i; + tree decl; + + FOR_EACH_VEC_SAFE_ELT (builtin_decls, i, decl) + if (DECL_NAME (decl) == name) + return decl; + + return NULL_TREE; +} + +/* The code below eventually exposes gnat_install_builtins, which declares + the builtin types and functions we might need, either internally or as + user accessible facilities. + + ??? This is a first implementation shot, still in rough shape. It is + heavily inspired from the "C" family implementation, with chunks copied + verbatim from there. + + Two obvious improvement candidates are: + o Use a more efficient name/decl mapping scheme + o Devise a middle-end infrastructure to avoid having to copy + pieces between front-ends. */ + +/* ----------------------------------------------------------------------- * + * BUILTIN ELEMENTARY TYPES * + * ----------------------------------------------------------------------- */ + +/* Standard data types to be used in builtin argument declarations. */ + +enum c_tree_index +{ + CTI_SIGNED_SIZE_TYPE, /* For format checking only. */ + CTI_STRING_TYPE, + CTI_CONST_STRING_TYPE, + + CTI_MAX +}; + +static tree c_global_trees[CTI_MAX]; + +#define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE] +#define string_type_node c_global_trees[CTI_STRING_TYPE] +#define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE] + +/* ??? In addition some attribute handlers, we currently don't support a + (small) number of builtin-types, which in turns inhibits support for a + number of builtin functions. */ +#define wint_type_node void_type_node +#define intmax_type_node void_type_node +#define uintmax_type_node void_type_node + +/* Used to help initialize the builtin-types.def table. When a type of + the correct size doesn't exist, use error_mark_node instead of NULL. + The later results in segfaults even when a decl using the type doesn't + get invoked. */ + +static tree +builtin_type_for_size (int size, bool unsignedp) +{ + tree type = gnat_type_for_size (size, unsignedp); + return type ? type : error_mark_node; +} + +/* Build/push the elementary type decls that builtin functions/types + will need. */ + +static void +install_builtin_elementary_types (void) +{ + signed_size_type_node = gnat_signed_type_for (size_type_node); + pid_type_node = integer_type_node; + + string_type_node = build_pointer_type (char_type_node); + const_string_type_node + = build_pointer_type (build_qualified_type + (char_type_node, TYPE_QUAL_CONST)); +} + +/* ----------------------------------------------------------------------- * + * BUILTIN FUNCTION TYPES * + * ----------------------------------------------------------------------- */ + +/* Now, builtin function types per se. */ + +enum c_builtin_type +{ +#define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME, +#define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME, +#define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME, +#define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME, +#define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, +#define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, +#define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME, +#define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6) NAME, +#define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7) NAME, +#define DEF_FUNCTION_TYPE_8(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7, ARG8) NAME, +#define DEF_FUNCTION_TYPE_9(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7, ARG8, ARG9) NAME, +#define DEF_FUNCTION_TYPE_10(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7, ARG8, ARG9, ARG10) NAME, +#define DEF_FUNCTION_TYPE_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME, +#define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME, +#define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME, +#define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME, +#define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, +#define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, +#define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ + NAME, +#define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6) NAME, +#define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7) NAME, +#define DEF_POINTER_TYPE(NAME, TYPE) NAME, +#include "builtin-types.def" +#undef DEF_PRIMITIVE_TYPE +#undef DEF_FUNCTION_TYPE_0 +#undef DEF_FUNCTION_TYPE_1 +#undef DEF_FUNCTION_TYPE_2 +#undef DEF_FUNCTION_TYPE_3 +#undef DEF_FUNCTION_TYPE_4 +#undef DEF_FUNCTION_TYPE_5 +#undef DEF_FUNCTION_TYPE_6 +#undef DEF_FUNCTION_TYPE_7 +#undef DEF_FUNCTION_TYPE_8 +#undef DEF_FUNCTION_TYPE_9 +#undef DEF_FUNCTION_TYPE_10 +#undef DEF_FUNCTION_TYPE_11 +#undef DEF_FUNCTION_TYPE_VAR_0 +#undef DEF_FUNCTION_TYPE_VAR_1 +#undef DEF_FUNCTION_TYPE_VAR_2 +#undef DEF_FUNCTION_TYPE_VAR_3 +#undef DEF_FUNCTION_TYPE_VAR_4 +#undef DEF_FUNCTION_TYPE_VAR_5 +#undef DEF_FUNCTION_TYPE_VAR_6 +#undef DEF_FUNCTION_TYPE_VAR_7 +#undef DEF_POINTER_TYPE + BT_LAST +}; + +typedef enum c_builtin_type builtin_type; + +/* A temporary array used in communication with def_fn_type. */ +static GTY(()) tree builtin_types[(int) BT_LAST + 1]; + +/* A helper function for install_builtin_types. Build function type + for DEF with return type RET and N arguments. If VAR is true, then the + function should be variadic after those N arguments. + + Takes special care not to ICE if any of the types involved are + error_mark_node, which indicates that said type is not in fact available + (see builtin_type_for_size). In which case the function type as a whole + should be error_mark_node. */ + +static void +def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...) +{ + tree t; + tree *args = XALLOCAVEC (tree, n); + va_list list; + int i; + + va_start (list, n); + for (i = 0; i < n; ++i) + { + builtin_type a = (builtin_type) va_arg (list, int); + t = builtin_types[a]; + if (t == error_mark_node) + goto egress; + args[i] = t; + } + + t = builtin_types[ret]; + if (t == error_mark_node) + goto egress; + if (var) + t = build_varargs_function_type_array (t, n, args); + else + t = build_function_type_array (t, n, args); + + egress: + builtin_types[def] = t; + va_end (list); +} + +/* Build the builtin function types and install them in the builtin_types + array for later use in builtin function decls. */ + +static void +install_builtin_function_types (void) +{ + tree va_list_ref_type_node; + tree va_list_arg_type_node; + + if (TREE_CODE (va_list_type_node) == ARRAY_TYPE) + { + va_list_arg_type_node = va_list_ref_type_node = + build_pointer_type (TREE_TYPE (va_list_type_node)); + } + else + { + va_list_arg_type_node = va_list_type_node; + va_list_ref_type_node = build_reference_type (va_list_type_node); + } + +#define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \ + builtin_types[ENUM] = VALUE; +#define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \ + def_fn_type (ENUM, RETURN, 0, 0); +#define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \ + def_fn_type (ENUM, RETURN, 0, 1, ARG1); +#define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \ + def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2); +#define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ + def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3); +#define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ + def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4); +#define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ + def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5); +#define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6) \ + def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6); +#define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7) \ + def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7); +#define DEF_FUNCTION_TYPE_8(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7, ARG8) \ + def_fn_type (ENUM, RETURN, 0, 8, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \ + ARG7, ARG8); +#define DEF_FUNCTION_TYPE_9(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7, ARG8, ARG9) \ + def_fn_type (ENUM, RETURN, 0, 9, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \ + ARG7, ARG8, ARG9); +#define DEF_FUNCTION_TYPE_10(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\ + ARG6, ARG7, ARG8, ARG9, ARG10) \ + def_fn_type (ENUM, RETURN, 0, 10, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \ + ARG7, ARG8, ARG9, ARG10); +#define DEF_FUNCTION_TYPE_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5,\ + ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \ + def_fn_type (ENUM, RETURN, 0, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, \ + ARG7, ARG8, ARG9, ARG10, ARG11); +#define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \ + def_fn_type (ENUM, RETURN, 1, 0); +#define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \ + def_fn_type (ENUM, RETURN, 1, 1, ARG1); +#define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \ + def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2); +#define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ + def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3); +#define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ + def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4); +#define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ + def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5); +#define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6) \ + def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6); +#define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7) \ + def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7); +#define DEF_POINTER_TYPE(ENUM, TYPE) \ + builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]); + +#include "builtin-types.def" + +#undef DEF_PRIMITIVE_TYPE +#undef DEF_FUNCTION_TYPE_0 +#undef DEF_FUNCTION_TYPE_1 +#undef DEF_FUNCTION_TYPE_2 +#undef DEF_FUNCTION_TYPE_3 +#undef DEF_FUNCTION_TYPE_4 +#undef DEF_FUNCTION_TYPE_5 +#undef DEF_FUNCTION_TYPE_6 +#undef DEF_FUNCTION_TYPE_7 +#undef DEF_FUNCTION_TYPE_8 +#undef DEF_FUNCTION_TYPE_9 +#undef DEF_FUNCTION_TYPE_10 +#undef DEF_FUNCTION_TYPE_11 +#undef DEF_FUNCTION_TYPE_VAR_0 +#undef DEF_FUNCTION_TYPE_VAR_1 +#undef DEF_FUNCTION_TYPE_VAR_2 +#undef DEF_FUNCTION_TYPE_VAR_3 +#undef DEF_FUNCTION_TYPE_VAR_4 +#undef DEF_FUNCTION_TYPE_VAR_5 +#undef DEF_FUNCTION_TYPE_VAR_6 +#undef DEF_FUNCTION_TYPE_VAR_7 +#undef DEF_POINTER_TYPE + builtin_types[(int) BT_LAST] = NULL_TREE; +} + +/* ----------------------------------------------------------------------- * + * BUILTIN ATTRIBUTES * + * ----------------------------------------------------------------------- */ + +enum built_in_attribute +{ +#define DEF_ATTR_NULL_TREE(ENUM) ENUM, +#define DEF_ATTR_INT(ENUM, VALUE) ENUM, +#define DEF_ATTR_STRING(ENUM, VALUE) ENUM, +#define DEF_ATTR_IDENT(ENUM, STRING) ENUM, +#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM, +#include "builtin-attrs.def" +#undef DEF_ATTR_NULL_TREE +#undef DEF_ATTR_INT +#undef DEF_ATTR_STRING +#undef DEF_ATTR_IDENT +#undef DEF_ATTR_TREE_LIST + ATTR_LAST +}; + +static GTY(()) tree built_in_attributes[(int) ATTR_LAST]; + +static void +install_builtin_attributes (void) +{ + /* Fill in the built_in_attributes array. */ +#define DEF_ATTR_NULL_TREE(ENUM) \ + built_in_attributes[(int) ENUM] = NULL_TREE; +#define DEF_ATTR_INT(ENUM, VALUE) \ + built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE); +#define DEF_ATTR_STRING(ENUM, VALUE) \ + built_in_attributes[(int) ENUM] = build_string (strlen (VALUE), VALUE); +#define DEF_ATTR_IDENT(ENUM, STRING) \ + built_in_attributes[(int) ENUM] = get_identifier (STRING); +#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \ + built_in_attributes[(int) ENUM] \ + = tree_cons (built_in_attributes[(int) PURPOSE], \ + built_in_attributes[(int) VALUE], \ + built_in_attributes[(int) CHAIN]); +#include "builtin-attrs.def" +#undef DEF_ATTR_NULL_TREE +#undef DEF_ATTR_INT +#undef DEF_ATTR_STRING +#undef DEF_ATTR_IDENT +#undef DEF_ATTR_TREE_LIST +} + +/* Handle a "const" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_const_attribute (tree *node, tree ARG_UNUSED (name), + tree ARG_UNUSED (args), int ARG_UNUSED (flags), + bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL) + TREE_READONLY (*node) = 1; + else + *no_add_attrs = true; + + return NULL_TREE; +} + +/* Handle a "nothrow" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_nothrow_attribute (tree *node, tree ARG_UNUSED (name), + tree ARG_UNUSED (args), int ARG_UNUSED (flags), + bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL) + TREE_NOTHROW (*node) = 1; + else + *no_add_attrs = true; + + return NULL_TREE; +} + +/* Handle a "pure" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL) + DECL_PURE_P (*node) = 1; + /* TODO: support types. */ + else + { + warning (OPT_Wattributes, "%qs attribute ignored", + IDENTIFIER_POINTER (name)); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "no vops" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_novops_attribute (tree *node, tree ARG_UNUSED (name), + tree ARG_UNUSED (args), int ARG_UNUSED (flags), + bool *ARG_UNUSED (no_add_attrs)) +{ + gcc_assert (TREE_CODE (*node) == FUNCTION_DECL); + DECL_IS_NOVOPS (*node) = 1; + return NULL_TREE; +} + +/* Helper for nonnull attribute handling; fetch the operand number + from the attribute argument list. */ + +static bool +get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp) +{ + /* Verify the arg number is a constant. */ + if (!tree_fits_uhwi_p (arg_num_expr)) + return false; + + *valp = TREE_INT_CST_LOW (arg_num_expr); + return true; +} + +/* Handle the "nonnull" attribute. */ +static tree +handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name), + tree args, int ARG_UNUSED (flags), + bool *no_add_attrs) +{ + tree type = *node; + unsigned HOST_WIDE_INT attr_arg_num; + + /* If no arguments are specified, all pointer arguments should be + non-null. Verify a full prototype is given so that the arguments + will have the correct types when we actually check them later. + Avoid diagnosing type-generic built-ins since those have no + prototype. */ + if (!args) + { + if (!prototype_p (type) + && (!TYPE_ATTRIBUTES (type) + || !lookup_attribute ("type generic", TYPE_ATTRIBUTES (type)))) + { + error ("nonnull attribute without arguments on a non-prototype"); + *no_add_attrs = true; + } + return NULL_TREE; + } + + /* Argument list specified. Verify that each argument number references + a pointer argument. */ + for (attr_arg_num = 1; args; args = TREE_CHAIN (args)) + { + unsigned HOST_WIDE_INT arg_num = 0, ck_num; + + if (!get_nonnull_operand (TREE_VALUE (args), &arg_num)) + { + error ("nonnull argument has invalid operand number (argument %lu)", + (unsigned long) attr_arg_num); + *no_add_attrs = true; + return NULL_TREE; + } + + if (prototype_p (type)) + { + function_args_iterator iter; + tree argument; + + function_args_iter_init (&iter, type); + for (ck_num = 1; ; ck_num++, function_args_iter_next (&iter)) + { + argument = function_args_iter_cond (&iter); + if (!argument || ck_num == arg_num) + break; + } + + if (!argument + || TREE_CODE (argument) == VOID_TYPE) + { + error ("nonnull argument with out-of-range operand number " + "(argument %lu, operand %lu)", + (unsigned long) attr_arg_num, (unsigned long) arg_num); + *no_add_attrs = true; + return NULL_TREE; + } + + if (TREE_CODE (argument) != POINTER_TYPE) + { + error ("nonnull argument references non-pointer operand " + "(argument %lu, operand %lu)", + (unsigned long) attr_arg_num, (unsigned long) arg_num); + *no_add_attrs = true; + return NULL_TREE; + } + } + } + + return NULL_TREE; +} + +/* Handle a "sentinel" attribute. */ + +static tree +handle_sentinel_attribute (tree *node, tree name, tree args, + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (!prototype_p (*node)) + { + warning (OPT_Wattributes, + "%qs attribute requires prototypes with named arguments", + IDENTIFIER_POINTER (name)); + *no_add_attrs = true; + } + else + { + if (!stdarg_p (*node)) + { + warning (OPT_Wattributes, + "%qs attribute only applies to variadic functions", + IDENTIFIER_POINTER (name)); + *no_add_attrs = true; + } + } + + if (args) + { + tree position = TREE_VALUE (args); + + if (TREE_CODE (position) != INTEGER_CST) + { + warning (0, "requested position is not an integer constant"); + *no_add_attrs = true; + } + else + { + if (tree_int_cst_lt (position, integer_zero_node)) + { + warning (0, "requested position is less than zero"); + *no_add_attrs = true; + } + } + } + + return NULL_TREE; +} + +/* Handle a "noreturn" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + tree type = TREE_TYPE (*node); + + /* See FIXME comment in c_common_attribute_table. */ + if (TREE_CODE (*node) == FUNCTION_DECL) + TREE_THIS_VOLATILE (*node) = 1; + else if (TREE_CODE (type) == POINTER_TYPE + && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) + TREE_TYPE (*node) + = build_pointer_type + (build_type_variant (TREE_TYPE (type), + TYPE_READONLY (TREE_TYPE (type)), 1)); + else + { + warning (OPT_Wattributes, "%qs attribute ignored", + IDENTIFIER_POINTER (name)); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "noinline" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_noinline_attribute (tree *node, tree name, + tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL) + { + if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (*node))) + { + warning (OPT_Wattributes, "%qE attribute ignored due to conflict " + "with attribute %qs", name, "always_inline"); + *no_add_attrs = true; + } + else + DECL_UNINLINABLE (*node) = 1; + } + else + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "noclone" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_noclone_attribute (tree *node, tree name, + tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) != FUNCTION_DECL) + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "leaf" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_leaf_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) != FUNCTION_DECL) + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + if (!TREE_PUBLIC (*node)) + { + warning (OPT_Wattributes, "%qE attribute has no effect", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "always_inline" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_always_inline_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL) + { + /* Set the attribute and mark it for disregarding inline limits. */ + DECL_DISREGARD_INLINE_LIMITS (*node) = 1; + } + else + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "malloc" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL + && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node)))) + DECL_IS_MALLOC (*node) = 1; + else + { + warning (OPT_Wattributes, "%qs attribute ignored", + IDENTIFIER_POINTER (name)); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Fake handler for attributes we don't properly support. */ + +tree +fake_attribute_handler (tree * ARG_UNUSED (node), + tree ARG_UNUSED (name), + tree ARG_UNUSED (args), + int ARG_UNUSED (flags), + bool * ARG_UNUSED (no_add_attrs)) +{ + return NULL_TREE; +} + +/* Handle a "type_generic" attribute. */ + +static tree +handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name), + tree ARG_UNUSED (args), int ARG_UNUSED (flags), + bool * ARG_UNUSED (no_add_attrs)) +{ + /* Ensure we have a function type. */ + gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE); + + /* Ensure we have a variadic function. */ + gcc_assert (!prototype_p (*node) || stdarg_p (*node)); + + return NULL_TREE; +} + +/* Handle a "vector_size" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_vector_size_attribute (tree *node, tree name, tree args, + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + tree type = *node; + tree vector_type; + + *no_add_attrs = true; + + /* We need to provide for vector pointers, vector arrays, and + functions returning vectors. For example: + + __attribute__((vector_size(16))) short *foo; + + In this case, the mode is SI, but the type being modified is + HI, so we need to look further. */ + while (POINTER_TYPE_P (type) + || TREE_CODE (type) == FUNCTION_TYPE + || TREE_CODE (type) == ARRAY_TYPE) + type = TREE_TYPE (type); + + vector_type = build_vector_type_for_size (type, TREE_VALUE (args), name); + if (!vector_type) + return NULL_TREE; + + /* Build back pointers if needed. */ + *node = reconstruct_complex_type (*node, vector_type); + + return NULL_TREE; +} + +/* Handle a "vector_type" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_vector_type_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + tree type = *node; + tree vector_type; + + *no_add_attrs = true; + + if (TREE_CODE (type) != ARRAY_TYPE) + { + error ("attribute %qs applies to array types only", + IDENTIFIER_POINTER (name)); + return NULL_TREE; + } + + vector_type = build_vector_type_for_array (type, name); + if (!vector_type) + return NULL_TREE; + + TYPE_REPRESENTATIVE_ARRAY (vector_type) = type; + *node = vector_type; + + return NULL_TREE; +} + +/* ----------------------------------------------------------------------- * + * BUILTIN FUNCTIONS * + * ----------------------------------------------------------------------- */ + +/* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two + names. Does not declare a non-__builtin_ function if flag_no_builtin, or + if nonansi_p and flag_no_nonansi_builtin. */ + +static void +def_builtin_1 (enum built_in_function fncode, + const char *name, + enum built_in_class fnclass, + tree fntype, tree libtype, + bool both_p, bool fallback_p, + bool nonansi_p ATTRIBUTE_UNUSED, + tree fnattrs, bool implicit_p) +{ + tree decl; + const char *libname; + + /* Preserve an already installed decl. It most likely was setup in advance + (e.g. as part of the internal builtins) for specific reasons. */ + if (builtin_decl_explicit (fncode)) + return; + + gcc_assert ((!both_p && !fallback_p) + || !strncmp (name, "__builtin_", + strlen ("__builtin_"))); + + libname = name + strlen ("__builtin_"); + decl = add_builtin_function (name, fntype, fncode, fnclass, + (fallback_p ? libname : NULL), + fnattrs); + if (both_p) + /* ??? This is normally further controlled by command-line options + like -fno-builtin, but we don't have them for Ada. */ + add_builtin_function (libname, libtype, fncode, fnclass, + NULL, fnattrs); + + set_builtin_decl (fncode, decl, implicit_p); +} + +static int flag_isoc94 = 0; +static int flag_isoc99 = 0; +static int flag_isoc11 = 0; + +/* Install what the common builtins.def offers. */ + +static void +install_builtin_functions (void) +{ +#define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \ + NONANSI_P, ATTRS, IMPLICIT, COND) \ + if (NAME && COND) \ + def_builtin_1 (ENUM, NAME, CLASS, \ + builtin_types[(int) TYPE], \ + builtin_types[(int) LIBTYPE], \ + BOTH_P, FALLBACK_P, NONANSI_P, \ + built_in_attributes[(int) ATTRS], IMPLICIT); +#include "builtins.def" +} + +/* ----------------------------------------------------------------------- * + * BUILTIN FUNCTIONS * + * ----------------------------------------------------------------------- */ + +/* Install the builtin functions we might need. */ + +void +gnat_install_builtins (void) +{ + install_builtin_elementary_types (); + install_builtin_function_types (); + install_builtin_attributes (); + + /* Install builtins used by generic middle-end pieces first. Some of these + know about internal specificities and control attributes accordingly, for + instance __builtin_alloca vs no-throw and -fstack-check. We will ignore + the generic definition from builtins.def. */ + build_common_builtin_nodes (); + + /* Now, install the target specific builtins, such as the AltiVec family on + ppc, and the common set as exposed by builtins.def. */ + targetm.init_builtins (); + install_builtin_functions (); +} + +#include "gt-ada-utils.h" +#include "gtype-ada.h"