1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2007, Free Software Foundation, Inc. *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License along with GCC; see the file COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
24 ****************************************************************************/
28 #include "coretypes.h"
41 #include "tree-inline.h"
42 #include "tree-gimple.h"
43 #include "tree-dump.h"
44 #include "pointer-set.h"
60 #ifndef MAX_FIXED_MODE_SIZE
61 #define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
64 #ifndef MAX_BITS_PER_WORD
65 #define MAX_BITS_PER_WORD BITS_PER_WORD
68 /* If nonzero, pretend we are allocating at global level. */
71 /* Tree nodes for the various types and decls we create. */
72 tree gnat_std_decls[(int) ADT_LAST];
74 /* Functions to call for each of the possible raise reasons. */
75 tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
77 /* Forward declarations for handlers of attributes. */
78 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
79 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
81 /* Table of machine-independent internal attributes for Ada. We support
82 this minimal set of attributes to accommodate the Alpha back-end which
83 unconditionally puts them on its builtins. */
84 const struct attribute_spec gnat_internal_attribute_table[] =
86 /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
87 { "const", 0, 0, true, false, false, handle_const_attribute },
88 { "nothrow", 0, 0, true, false, false, handle_nothrow_attribute },
89 { NULL, 0, 0, false, false, false, NULL }
92 /* Associates a GNAT tree node to a GCC tree node. It is used in
93 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
94 of `save_gnu_tree' for more info. */
95 static GTY((length ("max_gnat_nodes"))) tree *associate_gnat_to_gnu;
97 #define GET_GNU_TREE(GNAT_ENTITY) \
98 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id]
100 #define SET_GNU_TREE(GNAT_ENTITY,VAL) \
101 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL)
103 #define PRESENT_GNU_TREE(GNAT_ENTITY) \
104 (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
106 /* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */
107 static GTY((length ("max_gnat_nodes"))) tree *dummy_node_table;
109 #define GET_DUMMY_NODE(GNAT_ENTITY) \
110 dummy_node_table[(GNAT_ENTITY) - First_Node_Id]
112 #define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \
113 dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL)
115 #define PRESENT_DUMMY_NODE(GNAT_ENTITY) \
116 (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
118 /* This variable keeps a table for types for each precision so that we only
119 allocate each of them once. Signed and unsigned types are kept separate.
121 Note that these types are only used when fold-const requests something
122 special. Perhaps we should NOT share these types; we'll see how it
124 static GTY(()) tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2];
126 /* Likewise for float types, but record these by mode. */
127 static GTY(()) tree float_types[NUM_MACHINE_MODES];
129 /* For each binding contour we allocate a binding_level structure to indicate
130 the binding depth. */
132 struct gnat_binding_level GTY((chain_next ("%h.chain")))
134 /* The binding level containing this one (the enclosing binding level). */
135 struct gnat_binding_level *chain;
136 /* The BLOCK node for this level. */
138 /* If nonzero, the setjmp buffer that needs to be updated for any
139 variable-sized definition within this context. */
143 /* The binding level currently in effect. */
144 static GTY(()) struct gnat_binding_level *current_binding_level;
146 /* A chain of gnat_binding_level structures awaiting reuse. */
147 static GTY((deletable)) struct gnat_binding_level *free_binding_level;
149 /* An array of global declarations. */
150 static GTY(()) VEC(tree,gc) *global_decls;
152 /* An array of builtin declarations. */
153 static GTY(()) VEC(tree,gc) *builtin_decls;
155 /* An array of global renaming pointers. */
156 static GTY(()) VEC(tree,gc) *global_renaming_pointers;
158 /* A chain of unused BLOCK nodes. */
159 static GTY((deletable)) tree free_block_chain;
161 static void gnat_install_builtins (void);
162 static tree merge_sizes (tree, tree, tree, bool, bool);
163 static tree compute_related_constant (tree, tree);
164 static tree split_plus (tree, tree *);
165 static void gnat_gimplify_function (tree);
166 static tree float_type_for_precision (int, enum machine_mode);
167 static tree convert_to_fat_pointer (tree, tree);
168 static tree convert_to_thin_pointer (tree, tree);
169 static tree make_descriptor_field (const char *,tree, tree, tree);
170 static bool potential_alignment_gap (tree, tree, tree);
172 /* Initialize the association of GNAT nodes to GCC trees. */
175 init_gnat_to_gnu (void)
177 associate_gnat_to_gnu
178 = (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
181 /* GNAT_ENTITY is a GNAT tree node for an entity. GNU_DECL is the GCC tree
182 which is to be associated with GNAT_ENTITY. Such GCC tree node is always
183 a ..._DECL node. If NO_CHECK is nonzero, the latter check is suppressed.
185 If GNU_DECL is zero, a previous association is to be reset. */
188 save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl, bool no_check)
190 /* Check that GNAT_ENTITY is not already defined and that it is being set
191 to something which is a decl. Raise gigi 401 if not. Usually, this
192 means GNAT_ENTITY is defined twice, but occasionally is due to some
194 gcc_assert (!(gnu_decl
195 && (PRESENT_GNU_TREE (gnat_entity)
196 || (!no_check && !DECL_P (gnu_decl)))));
198 SET_GNU_TREE (gnat_entity, gnu_decl);
201 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
202 Return the ..._DECL node that was associated with it. If there is no tree
203 node associated with GNAT_ENTITY, abort.
205 In some cases, such as delayed elaboration or expressions that need to
206 be elaborated only once, GNAT_ENTITY is really not an entity. */
209 get_gnu_tree (Entity_Id gnat_entity)
211 gcc_assert (PRESENT_GNU_TREE (gnat_entity));
212 return GET_GNU_TREE (gnat_entity);
215 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
218 present_gnu_tree (Entity_Id gnat_entity)
220 return PRESENT_GNU_TREE (gnat_entity);
223 /* Initialize the association of GNAT nodes to GCC trees as dummies. */
226 init_dummy_type (void)
229 = (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
232 /* Make a dummy type corresponding to GNAT_TYPE. */
235 make_dummy_type (Entity_Id gnat_type)
237 Entity_Id gnat_underlying = Gigi_Equivalent_Type (gnat_type);
240 /* If there is an equivalent type, get its underlying type. */
241 if (Present (gnat_underlying))
242 gnat_underlying = Underlying_Type (gnat_underlying);
244 /* If there was no equivalent type (can only happen when just annotating
245 types) or underlying type, go back to the original type. */
246 if (No (gnat_underlying))
247 gnat_underlying = gnat_type;
249 /* If it there already a dummy type, use that one. Else make one. */
250 if (PRESENT_DUMMY_NODE (gnat_underlying))
251 return GET_DUMMY_NODE (gnat_underlying);
253 /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make
255 gnu_type = make_node (Is_Record_Type (gnat_underlying)
256 ? tree_code_for_record_type (gnat_underlying)
258 TYPE_NAME (gnu_type) = get_entity_name (gnat_type);
259 TYPE_DUMMY_P (gnu_type) = 1;
260 if (AGGREGATE_TYPE_P (gnu_type))
262 TYPE_STUB_DECL (gnu_type) = build_decl (TYPE_DECL, NULL_TREE, gnu_type);
263 TYPE_BY_REFERENCE_P (gnu_type) = Is_By_Reference_Type (gnat_type);
266 SET_DUMMY_NODE (gnat_underlying, gnu_type);
271 /* Return nonzero if we are currently in the global binding level. */
274 global_bindings_p (void)
276 return ((force_global || !current_function_decl) ? -1 : 0);
279 /* Enter a new binding level. */
284 struct gnat_binding_level *newlevel = NULL;
286 /* Reuse a struct for this binding level, if there is one. */
287 if (free_binding_level)
289 newlevel = free_binding_level;
290 free_binding_level = free_binding_level->chain;
294 = (struct gnat_binding_level *)
295 ggc_alloc (sizeof (struct gnat_binding_level));
297 /* Use a free BLOCK, if any; otherwise, allocate one. */
298 if (free_block_chain)
300 newlevel->block = free_block_chain;
301 free_block_chain = BLOCK_CHAIN (free_block_chain);
302 BLOCK_CHAIN (newlevel->block) = NULL_TREE;
305 newlevel->block = make_node (BLOCK);
307 /* Point the BLOCK we just made to its parent. */
308 if (current_binding_level)
309 BLOCK_SUPERCONTEXT (newlevel->block) = current_binding_level->block;
311 BLOCK_VARS (newlevel->block) = BLOCK_SUBBLOCKS (newlevel->block) = NULL_TREE;
312 TREE_USED (newlevel->block) = 1;
314 /* Add this level to the front of the chain (stack) of levels that are
316 newlevel->chain = current_binding_level;
317 newlevel->jmpbuf_decl = NULL_TREE;
318 current_binding_level = newlevel;
321 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
322 and point FNDECL to this BLOCK. */
325 set_current_block_context (tree fndecl)
327 BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl;
328 DECL_INITIAL (fndecl) = current_binding_level->block;
331 /* Set the jmpbuf_decl for the current binding level to DECL. */
334 set_block_jmpbuf_decl (tree decl)
336 current_binding_level->jmpbuf_decl = decl;
339 /* Get the jmpbuf_decl, if any, for the current binding level. */
342 get_block_jmpbuf_decl ()
344 return current_binding_level->jmpbuf_decl;
347 /* Exit a binding level. Set any BLOCK into the current code group. */
352 struct gnat_binding_level *level = current_binding_level;
353 tree block = level->block;
355 BLOCK_VARS (block) = nreverse (BLOCK_VARS (block));
356 BLOCK_SUBBLOCKS (block) = nreverse (BLOCK_SUBBLOCKS (block));
358 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
359 are no variables free the block and merge its subblocks into those of its
360 parent block. Otherwise, add it to the list of its parent. */
361 if (TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)
363 else if (BLOCK_VARS (block) == NULL_TREE)
365 BLOCK_SUBBLOCKS (level->chain->block)
366 = chainon (BLOCK_SUBBLOCKS (block),
367 BLOCK_SUBBLOCKS (level->chain->block));
368 BLOCK_CHAIN (block) = free_block_chain;
369 free_block_chain = block;
373 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (level->chain->block);
374 BLOCK_SUBBLOCKS (level->chain->block) = block;
375 TREE_USED (block) = 1;
376 set_block_for_group (block);
379 /* Free this binding structure. */
380 current_binding_level = level->chain;
381 level->chain = free_binding_level;
382 free_binding_level = level;
385 /* Insert BLOCK at the end of the list of subblocks of the
386 current binding level. This is used when a BIND_EXPR is expanded,
387 to handle the BLOCK node inside the BIND_EXPR. */
390 insert_block (tree block)
392 TREE_USED (block) = 1;
393 TREE_CHAIN (block) = BLOCK_SUBBLOCKS (current_binding_level->block);
394 BLOCK_SUBBLOCKS (current_binding_level->block) = block;
397 /* Records a ..._DECL node DECL as belonging to the current lexical scope
398 and uses GNAT_NODE for location information and propagating flags. */
401 gnat_pushdecl (tree decl, Node_Id gnat_node)
403 /* If at top level, there is no context. But PARM_DECLs always go in the
404 level of its function. */
405 if (global_bindings_p () && TREE_CODE (decl) != PARM_DECL)
406 DECL_CONTEXT (decl) = 0;
409 DECL_CONTEXT (decl) = current_function_decl;
411 /* Functions imported in another function are not really nested. */
412 if (TREE_CODE (decl) == FUNCTION_DECL && TREE_PUBLIC (decl))
413 DECL_NO_STATIC_CHAIN (decl) = 1;
416 TREE_NO_WARNING (decl) = (gnat_node == Empty || Warnings_Off (gnat_node));
418 /* Set the location of DECL and emit a declaration for it. */
419 if (Present (gnat_node))
420 Sloc_to_locus (Sloc (gnat_node), &DECL_SOURCE_LOCATION (decl));
421 add_decl_expr (decl, gnat_node);
423 /* Put the declaration on the list. The list of declarations is in reverse
424 order. The list will be reversed later. Put global variables in the
425 globals list and builtin functions in a dedicated list to speed up
426 further lookups. Don't put TYPE_DECLs for UNCONSTRAINED_ARRAY_TYPE into
427 the list, as they will cause trouble with the debugger and aren't needed
429 if (TREE_CODE (decl) != TYPE_DECL
430 || TREE_CODE (TREE_TYPE (decl)) != UNCONSTRAINED_ARRAY_TYPE)
432 if (global_bindings_p ())
434 VEC_safe_push (tree, gc, global_decls, decl);
436 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
437 VEC_safe_push (tree, gc, builtin_decls, decl);
441 TREE_CHAIN (decl) = BLOCK_VARS (current_binding_level->block);
442 BLOCK_VARS (current_binding_level->block) = decl;
446 /* For the declaration of a type, set its name if it either is not already
447 set, was set to an IDENTIFIER_NODE, indicating an internal name,
448 or if the previous type name was not derived from a source name.
449 We'd rather have the type named with a real name and all the pointer
450 types to the same object have the same POINTER_TYPE node. Code in the
451 equivalent function of c-decl.c makes a copy of the type node here, but
452 that may cause us trouble with incomplete types. We make an exception
453 for fat pointer types because the compiler automatically builds them
454 for unconstrained array types and the debugger uses them to represent
455 both these and pointers to these. */
456 if (TREE_CODE (decl) == TYPE_DECL && DECL_NAME (decl))
458 tree t = TREE_TYPE (decl);
460 if (!TYPE_NAME (t) || TREE_CODE (TYPE_NAME (t)) == IDENTIFIER_NODE)
461 TYPE_NAME (t) = decl;
462 else if (TYPE_FAT_POINTER_P (t))
464 tree tt = build_variant_type_copy (t);
465 TYPE_NAME (tt) = decl;
466 TREE_USED (tt) = TREE_USED (t);
467 TREE_TYPE (decl) = tt;
468 DECL_ORIGINAL_TYPE (decl) = t;
470 else if (DECL_ARTIFICIAL (TYPE_NAME (t)) && !DECL_ARTIFICIAL (decl))
471 TYPE_NAME (t) = decl;
475 /* Do little here. Set up the standard declarations later after the
476 front end has been run. */
479 gnat_init_decl_processing (void)
481 /* Make the binding_level structure for global names. */
482 current_function_decl = 0;
483 current_binding_level = 0;
484 free_binding_level = 0;
487 build_common_tree_nodes (true, true);
489 /* In Ada, we use a signed type for SIZETYPE. Use the signed type
490 corresponding to the size of Pmode. In most cases when ptr_mode and
491 Pmode differ, C will use the width of ptr_mode as sizetype. But we get
492 far better code using the width of Pmode. Make this here since we need
493 this before we can expand the GNAT types. */
494 size_type_node = gnat_type_for_size (GET_MODE_BITSIZE (Pmode), 0);
495 set_sizetype (size_type_node);
496 build_common_tree_nodes_2 (0);
498 ptr_void_type_node = build_pointer_type (void_type_node);
500 gnat_install_builtins ();
503 /* Install the builtin functions we might need. */
506 gnat_install_builtins ()
508 /* Builtins used by generic middle-end optimizers. */
509 build_common_builtin_nodes ();
511 /* Target specific builtins, such as the AltiVec family on ppc. */
512 targetm.init_builtins ();
515 /* Create the predefined scalar types such as `integer_type_node' needed
516 in the gcc back-end and initialize the global binding level. */
519 init_gigi_decls (tree long_long_float_type, tree exception_type)
524 /* Set the types that GCC and Gigi use from the front end. We would like
525 to do this for char_type_node, but it needs to correspond to the C
527 if (TREE_CODE (TREE_TYPE (long_long_float_type)) == INTEGER_TYPE)
529 /* In this case, the builtin floating point types are VAX float,
530 so make up a type for use. */
531 longest_float_type_node = make_node (REAL_TYPE);
532 TYPE_PRECISION (longest_float_type_node) = LONG_DOUBLE_TYPE_SIZE;
533 layout_type (longest_float_type_node);
534 create_type_decl (get_identifier ("longest float type"),
535 longest_float_type_node, NULL, false, true, Empty);
538 longest_float_type_node = TREE_TYPE (long_long_float_type);
540 except_type_node = TREE_TYPE (exception_type);
542 unsigned_type_node = gnat_type_for_size (INT_TYPE_SIZE, 1);
543 create_type_decl (get_identifier ("unsigned int"), unsigned_type_node,
544 NULL, false, true, Empty);
546 void_type_decl_node = create_type_decl (get_identifier ("void"),
547 void_type_node, NULL, false, true,
550 void_ftype = build_function_type (void_type_node, NULL_TREE);
551 ptr_void_ftype = build_pointer_type (void_ftype);
553 /* Now declare runtime functions. */
554 endlink = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
556 /* malloc is a function declaration tree for a function to allocate
558 malloc_decl = create_subprog_decl (get_identifier ("__gnat_malloc"),
560 build_function_type (ptr_void_type_node,
561 tree_cons (NULL_TREE,
564 NULL_TREE, false, true, true, NULL,
566 DECL_IS_MALLOC (malloc_decl) = 1;
568 /* free is a function declaration tree for a function to free memory. */
570 = create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE,
571 build_function_type (void_type_node,
572 tree_cons (NULL_TREE,
575 NULL_TREE, false, true, true, NULL, Empty);
577 /* Make the types and functions used for exception processing. */
579 = build_array_type (gnat_type_for_mode (Pmode, 0),
580 build_index_type (build_int_cst (NULL_TREE, 5)));
581 create_type_decl (get_identifier ("JMPBUF_T"), jmpbuf_type, NULL,
583 jmpbuf_ptr_type = build_pointer_type (jmpbuf_type);
585 /* Functions to get and set the jumpbuf pointer for the current thread. */
587 = create_subprog_decl
588 (get_identifier ("system__soft_links__get_jmpbuf_address_soft"),
589 NULL_TREE, build_function_type (jmpbuf_ptr_type, NULL_TREE),
590 NULL_TREE, false, true, true, NULL, Empty);
591 /* Avoid creating superfluous edges to __builtin_setjmp receivers. */
592 DECL_IS_PURE (get_jmpbuf_decl) = 1;
595 = create_subprog_decl
596 (get_identifier ("system__soft_links__set_jmpbuf_address_soft"),
598 build_function_type (void_type_node,
599 tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
600 NULL_TREE, false, true, true, NULL, Empty);
602 /* Function to get the current exception. */
604 = create_subprog_decl
605 (get_identifier ("system__soft_links__get_gnat_exception"),
607 build_function_type (build_pointer_type (except_type_node), NULL_TREE),
608 NULL_TREE, false, true, true, NULL, Empty);
609 /* Avoid creating superfluous edges to __builtin_setjmp receivers. */
610 DECL_IS_PURE (get_excptr_decl) = 1;
612 /* Functions that raise exceptions. */
614 = create_subprog_decl
615 (get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE,
616 build_function_type (void_type_node,
617 tree_cons (NULL_TREE,
618 build_pointer_type (except_type_node),
620 NULL_TREE, false, true, true, NULL, Empty);
622 /* Dummy objects to materialize "others" and "all others" in the exception
623 tables. These are exported by a-exexpr.adb, so see this unit for the
627 = create_var_decl (get_identifier ("OTHERS"),
628 get_identifier ("__gnat_others_value"),
629 integer_type_node, 0, 1, 0, 1, 1, 0, Empty);
632 = create_var_decl (get_identifier ("ALL_OTHERS"),
633 get_identifier ("__gnat_all_others_value"),
634 integer_type_node, 0, 1, 0, 1, 1, 0, Empty);
636 /* Hooks to call when entering/leaving an exception handler. */
638 = create_subprog_decl (get_identifier ("__gnat_begin_handler"), NULL_TREE,
639 build_function_type (void_type_node,
640 tree_cons (NULL_TREE,
643 NULL_TREE, false, true, true, NULL, Empty);
646 = create_subprog_decl (get_identifier ("__gnat_end_handler"), NULL_TREE,
647 build_function_type (void_type_node,
648 tree_cons (NULL_TREE,
651 NULL_TREE, false, true, true, NULL, Empty);
653 /* If in no exception handlers mode, all raise statements are redirected to
654 __gnat_last_chance_handler. No need to redefine raise_nodefer_decl, since
655 this procedure will never be called in this mode. */
656 if (No_Exception_Handlers_Set ())
659 = create_subprog_decl
660 (get_identifier ("__gnat_last_chance_handler"), NULL_TREE,
661 build_function_type (void_type_node,
662 tree_cons (NULL_TREE,
663 build_pointer_type (char_type_node),
664 tree_cons (NULL_TREE,
667 NULL_TREE, false, true, true, NULL, Empty);
669 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
670 gnat_raise_decls[i] = decl;
673 /* Otherwise, make one decl for each exception reason. */
674 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
678 sprintf (name, "__gnat_rcheck_%.2d", i);
680 = create_subprog_decl
681 (get_identifier (name), NULL_TREE,
682 build_function_type (void_type_node,
683 tree_cons (NULL_TREE,
686 tree_cons (NULL_TREE,
689 NULL_TREE, false, true, true, NULL, Empty);
692 /* Indicate that these never return. */
693 TREE_THIS_VOLATILE (raise_nodefer_decl) = 1;
694 TREE_SIDE_EFFECTS (raise_nodefer_decl) = 1;
695 TREE_TYPE (raise_nodefer_decl)
696 = build_qualified_type (TREE_TYPE (raise_nodefer_decl),
699 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
701 TREE_THIS_VOLATILE (gnat_raise_decls[i]) = 1;
702 TREE_SIDE_EFFECTS (gnat_raise_decls[i]) = 1;
703 TREE_TYPE (gnat_raise_decls[i])
704 = build_qualified_type (TREE_TYPE (gnat_raise_decls[i]),
708 /* setjmp returns an integer and has one operand, which is a pointer to
711 = create_subprog_decl
712 (get_identifier ("__builtin_setjmp"), NULL_TREE,
713 build_function_type (integer_type_node,
714 tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
715 NULL_TREE, false, true, true, NULL, Empty);
717 DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL;
718 DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP;
720 /* update_setjmp_buf updates a setjmp buffer from the current stack pointer
722 update_setjmp_buf_decl
723 = create_subprog_decl
724 (get_identifier ("__builtin_update_setjmp_buf"), NULL_TREE,
725 build_function_type (void_type_node,
726 tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
727 NULL_TREE, false, true, true, NULL, Empty);
729 DECL_BUILT_IN_CLASS (update_setjmp_buf_decl) = BUILT_IN_NORMAL;
730 DECL_FUNCTION_CODE (update_setjmp_buf_decl) = BUILT_IN_UPDATE_SETJMP_BUF;
732 main_identifier_node = get_identifier ("main");
735 /* Given a record type RECORD_TYPE and a chain of FIELD_DECL nodes FIELDLIST,
736 finish constructing the record or union type. If REP_LEVEL is zero, this
737 record has no representation clause and so will be entirely laid out here.
738 If REP_LEVEL is one, this record has a representation clause and has been
739 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
740 this record is derived from a parent record and thus inherits its layout;
741 only make a pass on the fields to finalize them. If DO_NOT_FINALIZE is
742 true, the record type is expected to be modified afterwards so it will
743 not be sent to the back-end for finalization. */
746 finish_record_type (tree record_type, tree fieldlist, int rep_level,
747 bool do_not_finalize)
749 enum tree_code code = TREE_CODE (record_type);
750 tree name = TYPE_NAME (record_type);
751 tree ada_size = bitsize_zero_node;
752 tree size = bitsize_zero_node;
753 bool var_size = false;
754 bool had_size = TYPE_SIZE (record_type) != 0;
755 bool had_size_unit = TYPE_SIZE_UNIT (record_type) != 0;
758 if (name && TREE_CODE (name) == TYPE_DECL)
759 name = DECL_NAME (name);
761 TYPE_FIELDS (record_type) = fieldlist;
762 TYPE_STUB_DECL (record_type) = build_decl (TYPE_DECL, name, record_type);
764 /* We don't need both the typedef name and the record name output in
765 the debugging information, since they are the same. */
766 DECL_ARTIFICIAL (TYPE_STUB_DECL (record_type)) = 1;
768 /* Globally initialize the record first. If this is a rep'ed record,
769 that just means some initializations; otherwise, layout the record. */
772 TYPE_ALIGN (record_type) = MAX (BITS_PER_UNIT, TYPE_ALIGN (record_type));
773 TYPE_MODE (record_type) = BLKmode;
776 TYPE_SIZE_UNIT (record_type) = size_zero_node;
778 TYPE_SIZE (record_type) = bitsize_zero_node;
780 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
781 out just like a UNION_TYPE, since the size will be fixed. */
782 else if (code == QUAL_UNION_TYPE)
787 /* Ensure there isn't a size already set. There can be in an error
788 case where there is a rep clause but all fields have errors and
789 no longer have a position. */
790 TYPE_SIZE (record_type) = 0;
791 layout_type (record_type);
794 /* At this point, the position and size of each field is known. It was
795 either set before entry by a rep clause, or by laying out the type above.
797 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
798 to compute the Ada size; the GCC size and alignment (for rep'ed records
799 that are not padding types); and the mode (for rep'ed records). We also
800 clear the DECL_BIT_FIELD indication for the cases we know have not been
801 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
803 if (code == QUAL_UNION_TYPE)
804 fieldlist = nreverse (fieldlist);
806 for (field = fieldlist; field; field = TREE_CHAIN (field))
808 tree pos = bit_position (field);
810 tree type = TREE_TYPE (field);
811 tree this_size = DECL_SIZE (field);
812 tree this_ada_size = DECL_SIZE (field);
814 /* We need to make an XVE/XVU record if any field has variable size,
815 whether or not the record does. For example, if we have a union,
816 it may be that all fields, rounded up to the alignment, have the
817 same size, in which case we'll use that size. But the debug
818 output routines (except Dwarf2) won't be able to output the fields,
819 so we need to make the special record. */
820 if (TREE_CODE (this_size) != INTEGER_CST)
823 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
824 || TREE_CODE (type) == QUAL_UNION_TYPE)
825 && !TYPE_IS_FAT_POINTER_P (type)
826 && !TYPE_CONTAINS_TEMPLATE_P (type)
827 && TYPE_ADA_SIZE (type))
828 this_ada_size = TYPE_ADA_SIZE (type);
830 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
831 if (DECL_BIT_FIELD (field) && !STRICT_ALIGNMENT
832 && value_factor_p (pos, BITS_PER_UNIT)
833 && operand_equal_p (this_size, TYPE_SIZE (type), 0))
834 DECL_BIT_FIELD (field) = 0;
836 /* If we still have DECL_BIT_FIELD set at this point, we know the field
837 is technically not addressable. Except that it can actually be
838 addressed if the field is BLKmode and happens to be properly
840 DECL_NONADDRESSABLE_P (field)
841 |= DECL_BIT_FIELD (field) && DECL_MODE (field) != BLKmode;
843 if ((rep_level > 0) && !DECL_BIT_FIELD (field))
844 TYPE_ALIGN (record_type)
845 = MAX (TYPE_ALIGN (record_type), DECL_ALIGN (field));
850 ada_size = size_binop (MAX_EXPR, ada_size, this_ada_size);
851 size = size_binop (MAX_EXPR, size, this_size);
854 case QUAL_UNION_TYPE:
856 = fold_build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
857 this_ada_size, ada_size);
858 size = fold_build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
863 /* Since we know here that all fields are sorted in order of
864 increasing bit position, the size of the record is one
865 higher than the ending bit of the last field processed
866 unless we have a rep clause, since in that case we might
867 have a field outside a QUAL_UNION_TYPE that has a higher ending
868 position. So use a MAX in that case. Also, if this field is a
869 QUAL_UNION_TYPE, we need to take into account the previous size in
870 the case of empty variants. */
872 = merge_sizes (ada_size, pos, this_ada_size,
873 TREE_CODE (type) == QUAL_UNION_TYPE, rep_level > 0);
875 = merge_sizes (size, pos, this_size,
876 TREE_CODE (type) == QUAL_UNION_TYPE, rep_level > 0);
884 if (code == QUAL_UNION_TYPE)
885 nreverse (fieldlist);
889 /* If this is a padding record, we never want to make the size smaller
890 than what was specified in it, if any. */
891 if (TREE_CODE (record_type) == RECORD_TYPE
892 && TYPE_IS_PADDING_P (record_type) && TYPE_SIZE (record_type))
893 size = TYPE_SIZE (record_type);
895 /* Now set any of the values we've just computed that apply. */
896 if (!TYPE_IS_FAT_POINTER_P (record_type)
897 && !TYPE_CONTAINS_TEMPLATE_P (record_type))
898 SET_TYPE_ADA_SIZE (record_type, ada_size);
902 tree size_unit = had_size_unit
903 ? TYPE_SIZE_UNIT (record_type)
905 size_binop (CEIL_DIV_EXPR, size,
907 unsigned int align = TYPE_ALIGN (record_type);
909 TYPE_SIZE (record_type) = variable_size (round_up (size, align));
910 TYPE_SIZE_UNIT (record_type)
911 = variable_size (round_up (size_unit, align / BITS_PER_UNIT));
913 compute_record_mode (record_type);
917 if (!do_not_finalize)
918 rest_of_record_type_compilation (record_type);
921 /* Wrap up compilation of RECORD_TYPE, i.e. most notably output all
922 the debug information associated with it. It need not be invoked
923 directly in most cases since finish_record_type takes care of doing
924 so, unless explicitly requested not to through DO_NOT_FINALIZE. */
927 rest_of_record_type_compilation (tree record_type)
929 tree fieldlist = TYPE_FIELDS (record_type);
931 enum tree_code code = TREE_CODE (record_type);
932 bool var_size = false;
934 for (field = fieldlist; field; field = TREE_CHAIN (field))
936 /* We need to make an XVE/XVU record if any field has variable size,
937 whether or not the record does. For example, if we have a union,
938 it may be that all fields, rounded up to the alignment, have the
939 same size, in which case we'll use that size. But the debug
940 output routines (except Dwarf2) won't be able to output the fields,
941 so we need to make the special record. */
942 if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST
943 /* If a field has a non-constant qualifier, the record will have
944 variable size too. */
945 || (code == QUAL_UNION_TYPE
946 && TREE_CODE (DECL_QUALIFIER (field)) != INTEGER_CST))
953 /* If this record is of variable size, rename it so that the
954 debugger knows it is and make a new, parallel, record
955 that tells the debugger how the record is laid out. See
956 exp_dbug.ads. But don't do this for records that are padding
957 since they confuse GDB. */
959 && !(TREE_CODE (record_type) == RECORD_TYPE
960 && TYPE_IS_PADDING_P (record_type)))
963 = make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE
964 ? UNION_TYPE : TREE_CODE (record_type));
965 tree orig_name = TYPE_NAME (record_type);
967 = (TREE_CODE (orig_name) == TYPE_DECL ? DECL_NAME (orig_name)
970 = concat_id_with_name (orig_id,
971 TREE_CODE (record_type) == QUAL_UNION_TYPE
973 tree last_pos = bitsize_zero_node;
975 tree prev_old_field = 0;
977 TYPE_NAME (new_record_type) = new_id;
978 TYPE_ALIGN (new_record_type) = BIGGEST_ALIGNMENT;
979 TYPE_STUB_DECL (new_record_type)
980 = build_decl (TYPE_DECL, new_id, new_record_type);
981 DECL_ARTIFICIAL (TYPE_STUB_DECL (new_record_type)) = 1;
982 DECL_IGNORED_P (TYPE_STUB_DECL (new_record_type))
983 = DECL_IGNORED_P (TYPE_STUB_DECL (record_type));
984 TYPE_SIZE (new_record_type) = size_int (TYPE_ALIGN (record_type));
985 TYPE_SIZE_UNIT (new_record_type)
986 = size_int (TYPE_ALIGN (record_type) / BITS_PER_UNIT);
988 /* Now scan all the fields, replacing each field with a new
989 field corresponding to the new encoding. */
990 for (old_field = TYPE_FIELDS (record_type); old_field;
991 old_field = TREE_CHAIN (old_field))
993 tree field_type = TREE_TYPE (old_field);
994 tree field_name = DECL_NAME (old_field);
996 tree curpos = bit_position (old_field);
998 unsigned int align = 0;
1001 /* See how the position was modified from the last position.
1003 There are two basic cases we support: a value was added
1004 to the last position or the last position was rounded to
1005 a boundary and they something was added. Check for the
1006 first case first. If not, see if there is any evidence
1007 of rounding. If so, round the last position and try
1010 If this is a union, the position can be taken as zero. */
1012 if (TREE_CODE (new_record_type) == UNION_TYPE)
1013 pos = bitsize_zero_node, align = 0;
1015 pos = compute_related_constant (curpos, last_pos);
1017 if (!pos && TREE_CODE (curpos) == MULT_EXPR
1018 && host_integerp (TREE_OPERAND (curpos, 1), 1))
1020 tree offset = TREE_OPERAND (curpos, 0);
1021 align = tree_low_cst (TREE_OPERAND (curpos, 1), 1);
1023 /* Strip off any conversions. */
1024 while (TREE_CODE (offset) == NON_LVALUE_EXPR
1025 || TREE_CODE (offset) == NOP_EXPR
1026 || TREE_CODE (offset) == CONVERT_EXPR)
1027 offset = TREE_OPERAND (offset, 0);
1029 /* An offset which is a bitwise AND with a negative power of 2
1030 means an alignment corresponding to this power of 2. */
1031 if (TREE_CODE (offset) == BIT_AND_EXPR
1032 && host_integerp (TREE_OPERAND (offset, 1), 0)
1033 && tree_int_cst_sgn (TREE_OPERAND (offset, 1)) < 0)
1036 = - tree_low_cst (TREE_OPERAND (offset, 1), 0);
1037 if (exact_log2 (pow) > 0)
1041 pos = compute_related_constant (curpos,
1042 round_up (last_pos, align));
1044 else if (!pos && TREE_CODE (curpos) == PLUS_EXPR
1045 && TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST
1046 && TREE_CODE (TREE_OPERAND (curpos, 0)) == MULT_EXPR
1047 && host_integerp (TREE_OPERAND
1048 (TREE_OPERAND (curpos, 0), 1),
1053 (TREE_OPERAND (TREE_OPERAND (curpos, 0), 1), 1);
1054 pos = compute_related_constant (curpos,
1055 round_up (last_pos, align));
1057 else if (potential_alignment_gap (prev_old_field, old_field,
1060 align = TYPE_ALIGN (field_type);
1061 pos = compute_related_constant (curpos,
1062 round_up (last_pos, align));
1065 /* If we can't compute a position, set it to zero.
1067 ??? We really should abort here, but it's too much work
1068 to get this correct for all cases. */
1071 pos = bitsize_zero_node;
1073 /* See if this type is variable-sized and make a pointer type
1074 and indicate the indirection if so. Beware that the debug
1075 back-end may adjust the position computed above according
1076 to the alignment of the field type, i.e. the pointer type
1077 in this case, if we don't preventively counter that. */
1078 if (TREE_CODE (DECL_SIZE (old_field)) != INTEGER_CST)
1080 field_type = build_pointer_type (field_type);
1081 if (align != 0 && TYPE_ALIGN (field_type) > align)
1083 field_type = copy_node (field_type);
1084 TYPE_ALIGN (field_type) = align;
1089 /* Make a new field name, if necessary. */
1090 if (var || align != 0)
1095 sprintf (suffix, "XV%c%u", var ? 'L' : 'A',
1096 align / BITS_PER_UNIT);
1098 strcpy (suffix, "XVL");
1100 field_name = concat_id_with_name (field_name, suffix);
1103 new_field = create_field_decl (field_name, field_type,
1105 DECL_SIZE (old_field), pos, 0);
1106 TREE_CHAIN (new_field) = TYPE_FIELDS (new_record_type);
1107 TYPE_FIELDS (new_record_type) = new_field;
1109 /* If old_field is a QUAL_UNION_TYPE, take its size as being
1110 zero. The only time it's not the last field of the record
1111 is when there are other components at fixed positions after
1112 it (meaning there was a rep clause for every field) and we
1113 want to be able to encode them. */
1114 last_pos = size_binop (PLUS_EXPR, bit_position (old_field),
1115 (TREE_CODE (TREE_TYPE (old_field))
1118 : DECL_SIZE (old_field));
1119 prev_old_field = old_field;
1122 TYPE_FIELDS (new_record_type)
1123 = nreverse (TYPE_FIELDS (new_record_type));
1125 rest_of_type_decl_compilation (TYPE_STUB_DECL (new_record_type));
1128 rest_of_type_decl_compilation (TYPE_STUB_DECL (record_type));
1131 /* Utility function of above to merge LAST_SIZE, the previous size of a record
1132 with FIRST_BIT and SIZE that describe a field. SPECIAL is nonzero
1133 if this represents a QUAL_UNION_TYPE in which case we must look for
1134 COND_EXPRs and replace a value of zero with the old size. If HAS_REP
1135 is nonzero, we must take the MAX of the end position of this field
1136 with LAST_SIZE. In all other cases, we use FIRST_BIT plus SIZE.
1138 We return an expression for the size. */
1141 merge_sizes (tree last_size, tree first_bit, tree size, bool special,
1144 tree type = TREE_TYPE (last_size);
1147 if (!special || TREE_CODE (size) != COND_EXPR)
1149 new = size_binop (PLUS_EXPR, first_bit, size);
1151 new = size_binop (MAX_EXPR, last_size, new);
1155 new = fold_build3 (COND_EXPR, type, TREE_OPERAND (size, 0),
1156 integer_zerop (TREE_OPERAND (size, 1))
1157 ? last_size : merge_sizes (last_size, first_bit,
1158 TREE_OPERAND (size, 1),
1160 integer_zerop (TREE_OPERAND (size, 2))
1161 ? last_size : merge_sizes (last_size, first_bit,
1162 TREE_OPERAND (size, 2),
1165 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
1166 when fed through substitute_in_expr) into thinking that a constant
1167 size is not constant. */
1168 while (TREE_CODE (new) == NON_LVALUE_EXPR)
1169 new = TREE_OPERAND (new, 0);
1174 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
1175 related by the addition of a constant. Return that constant if so. */
1178 compute_related_constant (tree op0, tree op1)
1180 tree op0_var, op1_var;
1181 tree op0_con = split_plus (op0, &op0_var);
1182 tree op1_con = split_plus (op1, &op1_var);
1183 tree result = size_binop (MINUS_EXPR, op0_con, op1_con);
1185 if (operand_equal_p (op0_var, op1_var, 0))
1187 else if (operand_equal_p (op0, size_binop (PLUS_EXPR, op1_var, result), 0))
1193 /* Utility function of above to split a tree OP which may be a sum, into a
1194 constant part, which is returned, and a variable part, which is stored
1195 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
1199 split_plus (tree in, tree *pvar)
1201 /* Strip NOPS in order to ease the tree traversal and maximize the
1202 potential for constant or plus/minus discovery. We need to be careful
1203 to always return and set *pvar to bitsizetype trees, but it's worth
1207 *pvar = convert (bitsizetype, in);
1209 if (TREE_CODE (in) == INTEGER_CST)
1211 *pvar = bitsize_zero_node;
1212 return convert (bitsizetype, in);
1214 else if (TREE_CODE (in) == PLUS_EXPR || TREE_CODE (in) == MINUS_EXPR)
1216 tree lhs_var, rhs_var;
1217 tree lhs_con = split_plus (TREE_OPERAND (in, 0), &lhs_var);
1218 tree rhs_con = split_plus (TREE_OPERAND (in, 1), &rhs_var);
1220 if (lhs_var == TREE_OPERAND (in, 0)
1221 && rhs_var == TREE_OPERAND (in, 1))
1222 return bitsize_zero_node;
1224 *pvar = size_binop (TREE_CODE (in), lhs_var, rhs_var);
1225 return size_binop (TREE_CODE (in), lhs_con, rhs_con);
1228 return bitsize_zero_node;
1231 /* Return a FUNCTION_TYPE node. RETURN_TYPE is the type returned by the
1232 subprogram. If it is void_type_node, then we are dealing with a procedure,
1233 otherwise we are dealing with a function. PARAM_DECL_LIST is a list of
1234 PARM_DECL nodes that are the subprogram arguments. CICO_LIST is the
1235 copy-in/copy-out list to be stored into TYPE_CICO_LIST.
1236 RETURNS_UNCONSTRAINED is nonzero if the function returns an unconstrained
1237 object. RETURNS_BY_REF is nonzero if the function returns by reference.
1238 RETURNS_WITH_DSP is nonzero if the function is to return with a
1239 depressed stack pointer. RETURNS_BY_TARGET_PTR is true if the function
1240 is to be passed (as its first parameter) the address of the place to copy
1244 create_subprog_type (tree return_type, tree param_decl_list, tree cico_list,
1245 bool returns_unconstrained, bool returns_by_ref,
1246 bool returns_with_dsp, bool returns_by_target_ptr)
1248 /* A chain of TREE_LIST nodes whose TREE_VALUEs are the data type nodes of
1249 the subprogram formal parameters. This list is generated by traversing the
1250 input list of PARM_DECL nodes. */
1251 tree param_type_list = NULL;
1255 for (param_decl = param_decl_list; param_decl;
1256 param_decl = TREE_CHAIN (param_decl))
1257 param_type_list = tree_cons (NULL_TREE, TREE_TYPE (param_decl),
1260 /* The list of the function parameter types has to be terminated by the void
1261 type to signal to the back-end that we are not dealing with a variable
1262 parameter subprogram, but that the subprogram has a fixed number of
1264 param_type_list = tree_cons (NULL_TREE, void_type_node, param_type_list);
1266 /* The list of argument types has been created in reverse
1268 param_type_list = nreverse (param_type_list);
1270 type = build_function_type (return_type, param_type_list);
1272 /* TYPE may have been shared since GCC hashes types. If it has a CICO_LIST
1273 or the new type should, make a copy of TYPE. Likewise for
1274 RETURNS_UNCONSTRAINED and RETURNS_BY_REF. */
1275 if (TYPE_CI_CO_LIST (type) || cico_list
1276 || TYPE_RETURNS_UNCONSTRAINED_P (type) != returns_unconstrained
1277 || TYPE_RETURNS_BY_REF_P (type) != returns_by_ref
1278 || TYPE_RETURNS_BY_TARGET_PTR_P (type) != returns_by_target_ptr)
1279 type = copy_type (type);
1281 TYPE_CI_CO_LIST (type) = cico_list;
1282 TYPE_RETURNS_UNCONSTRAINED_P (type) = returns_unconstrained;
1283 TYPE_RETURNS_STACK_DEPRESSED (type) = returns_with_dsp;
1284 TYPE_RETURNS_BY_REF_P (type) = returns_by_ref;
1285 TYPE_RETURNS_BY_TARGET_PTR_P (type) = returns_by_target_ptr;
1289 /* Return a copy of TYPE but safe to modify in any way. */
1292 copy_type (tree type)
1294 tree new = copy_node (type);
1296 /* copy_node clears this field instead of copying it, because it is
1297 aliased with TREE_CHAIN. */
1298 TYPE_STUB_DECL (new) = TYPE_STUB_DECL (type);
1300 TYPE_POINTER_TO (new) = 0;
1301 TYPE_REFERENCE_TO (new) = 0;
1302 TYPE_MAIN_VARIANT (new) = new;
1303 TYPE_NEXT_VARIANT (new) = 0;
1308 /* Return an INTEGER_TYPE of SIZETYPE with range MIN to MAX and whose
1309 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position of
1313 create_index_type (tree min, tree max, tree index, Node_Id gnat_node)
1315 /* First build a type for the desired range. */
1316 tree type = build_index_2_type (min, max);
1318 /* If this type has the TYPE_INDEX_TYPE we want, return it. Otherwise, if it
1319 doesn't have TYPE_INDEX_TYPE set, set it to INDEX. If TYPE_INDEX_TYPE
1320 is set, but not to INDEX, make a copy of this type with the requested
1321 index type. Note that we have no way of sharing these types, but that's
1322 only a small hole. */
1323 if (TYPE_INDEX_TYPE (type) == index)
1325 else if (TYPE_INDEX_TYPE (type))
1326 type = copy_type (type);
1328 SET_TYPE_INDEX_TYPE (type, index);
1329 create_type_decl (NULL_TREE, type, NULL, true, false, gnat_node);
1333 /* Return a TYPE_DECL node. TYPE_NAME gives the name of the type (a character
1334 string) and TYPE is a ..._TYPE node giving its data type.
1335 ARTIFICIAL_P is true if this is a declaration that was generated
1336 by the compiler. DEBUG_INFO_P is true if we need to write debugging
1337 information about this type. GNAT_NODE is used for the position of
1341 create_type_decl (tree type_name, tree type, struct attrib *attr_list,
1342 bool artificial_p, bool debug_info_p, Node_Id gnat_node)
1344 tree type_decl = build_decl (TYPE_DECL, type_name, type);
1345 enum tree_code code = TREE_CODE (type);
1347 DECL_ARTIFICIAL (type_decl) = artificial_p;
1349 if (!TYPE_IS_DUMMY_P (type))
1350 gnat_pushdecl (type_decl, gnat_node);
1352 process_attributes (type_decl, attr_list);
1354 /* Pass type declaration information to the debugger unless this is an
1355 UNCONSTRAINED_ARRAY_TYPE, which the debugger does not support,
1356 and ENUMERAL_TYPE or RECORD_TYPE which is handled separately, or
1357 type for which debugging information was not requested. */
1358 if (code == UNCONSTRAINED_ARRAY_TYPE || !debug_info_p)
1359 DECL_IGNORED_P (type_decl) = 1;
1360 else if (code != ENUMERAL_TYPE
1361 && (code != RECORD_TYPE || TYPE_IS_FAT_POINTER_P (type))
1362 && !((code == POINTER_TYPE || code == REFERENCE_TYPE)
1363 && TYPE_IS_DUMMY_P (TREE_TYPE (type))))
1364 rest_of_type_decl_compilation (type_decl);
1369 /* Helper for create_var_decl and create_true_var_decl. Returns a GCC VAR_DECL
1372 VAR_NAME gives the name of the variable. ASM_NAME is its assembler name
1373 (if provided). TYPE is its data type (a GCC ..._TYPE node). VAR_INIT is
1374 the GCC tree for an optional initial expression; NULL_TREE if none.
1376 CONST_FLAG is true if this variable is constant, in which case we might
1377 return a CONST_DECL node unless CONST_DECL_ALLOWED_FLAG is false.
1379 PUBLIC_FLAG is true if this definition is to be made visible outside of
1380 the current compilation unit. This flag should be set when processing the
1381 variable definitions in a package specification. EXTERN_FLAG is nonzero
1382 when processing an external variable declaration (as opposed to a
1383 definition: no storage is to be allocated for the variable here).
1385 STATIC_FLAG is only relevant when not at top level. In that case
1386 it indicates whether to always allocate storage to the variable.
1388 GNAT_NODE is used for the position of the decl. */
1391 create_var_decl_1 (tree var_name, tree asm_name, tree type, tree var_init,
1392 bool const_flag, bool const_decl_allowed_flag,
1393 bool public_flag, bool extern_flag, bool static_flag,
1394 struct attrib *attr_list, Node_Id gnat_node)
1398 && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (var_init))
1399 && (global_bindings_p () || static_flag
1400 ? initializer_constant_valid_p (var_init, TREE_TYPE (var_init)) != 0
1401 : TREE_CONSTANT (var_init)));
1403 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
1404 case the initializer may be used in-lieu of the DECL node (as done in
1405 Identifier_to_gnu). This is useful to prevent the need of elaboration
1406 code when an identifier for which such a decl is made is in turn used as
1407 an initializer. We used to rely on CONST vs VAR_DECL for this purpose,
1408 but extra constraints apply to this choice (see below) and are not
1409 relevant to the distinction we wish to make. */
1410 bool constant_p = const_flag && init_const;
1412 /* The actual DECL node. CONST_DECL was initially intended for enumerals
1413 and may be used for scalars in general but not for aggregates. */
1415 = build_decl ((constant_p && const_decl_allowed_flag
1416 && !AGGREGATE_TYPE_P (type)) ? CONST_DECL : VAR_DECL,
1419 /* If this is external, throw away any initializations (they will be done
1420 elsewhere) unless this is a a constant for which we would like to remain
1421 able to get the initializer. If we are defining a global here, leave a
1422 constant initialization and save any variable elaborations for the
1423 elaboration routine. If we are just annotating types, throw away the
1424 initialization if it isn't a constant. */
1425 if ((extern_flag && !constant_p)
1426 || (type_annotate_only && var_init && !TREE_CONSTANT (var_init)))
1427 var_init = NULL_TREE;
1429 /* At the global level, an initializer requiring code to be generated
1430 produces elaboration statements. Check that such statements are allowed,
1431 that is, not violating a No_Elaboration_Code restriction. */
1432 if (global_bindings_p () && var_init != 0 && ! init_const)
1433 Check_Elaboration_Code_Allowed (gnat_node);
1435 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
1436 try to fiddle with DECL_COMMON. However, on platforms that don't
1437 support global BSS sections, uninitialized global variables would
1438 go in DATA instead, thus increasing the size of the executable. */
1440 && TREE_CODE (var_decl) == VAR_DECL
1441 && !have_global_bss_p ())
1442 DECL_COMMON (var_decl) = 1;
1443 DECL_INITIAL (var_decl) = var_init;
1444 TREE_READONLY (var_decl) = const_flag;
1445 DECL_EXTERNAL (var_decl) = extern_flag;
1446 TREE_PUBLIC (var_decl) = public_flag || extern_flag;
1447 TREE_CONSTANT (var_decl) = constant_p;
1448 TREE_THIS_VOLATILE (var_decl) = TREE_SIDE_EFFECTS (var_decl)
1449 = TYPE_VOLATILE (type);
1451 /* If it's public and not external, always allocate storage for it.
1452 At the global binding level we need to allocate static storage for the
1453 variable if and only if it's not external. If we are not at the top level
1454 we allocate automatic storage unless requested not to. */
1455 TREE_STATIC (var_decl)
1456 = public_flag || (global_bindings_p () ? !extern_flag : static_flag);
1458 if (asm_name && VAR_OR_FUNCTION_DECL_P (var_decl))
1459 SET_DECL_ASSEMBLER_NAME (var_decl, asm_name);
1461 process_attributes (var_decl, attr_list);
1463 /* Add this decl to the current binding level. */
1464 gnat_pushdecl (var_decl, gnat_node);
1466 if (TREE_SIDE_EFFECTS (var_decl))
1467 TREE_ADDRESSABLE (var_decl) = 1;
1469 if (TREE_CODE (var_decl) != CONST_DECL)
1471 if (global_bindings_p ())
1472 rest_of_decl_compilation (var_decl, true, 0);
1475 expand_decl (var_decl);
1480 /* Wrapper around create_var_decl_1 for cases where we don't care whether
1481 a VAR or a CONST decl node is created. */
1484 create_var_decl (tree var_name, tree asm_name, tree type, tree var_init,
1485 bool const_flag, bool public_flag, bool extern_flag,
1486 bool static_flag, struct attrib *attr_list,
1489 return create_var_decl_1 (var_name, asm_name, type, var_init,
1491 public_flag, extern_flag, static_flag,
1492 attr_list, gnat_node);
1495 /* Wrapper around create_var_decl_1 for cases where a VAR_DECL node is
1496 required. The primary intent is for DECL_CONST_CORRESPONDING_VARs, which
1497 must be VAR_DECLs and on which we want TREE_READONLY set to have them
1498 possibly assigned to a readonly data section. */
1501 create_true_var_decl (tree var_name, tree asm_name, tree type, tree var_init,
1502 bool const_flag, bool public_flag, bool extern_flag,
1503 bool static_flag, struct attrib *attr_list,
1506 return create_var_decl_1 (var_name, asm_name, type, var_init,
1508 public_flag, extern_flag, static_flag,
1509 attr_list, gnat_node);
1512 /* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its
1513 type, and RECORD_TYPE is the type of the parent. PACKED is nonzero if
1514 this field is in a record type with a "pragma pack". If SIZE is nonzero
1515 it is the specified size for this field. If POS is nonzero, it is the bit
1516 position. If ADDRESSABLE is nonzero, it means we are allowed to take
1517 the address of this field for aliasing purposes. If it is negative, we
1518 should not make a bitfield, which is used by make_aligning_type. */
1521 create_field_decl (tree field_name, tree field_type, tree record_type,
1522 int packed, tree size, tree pos, int addressable)
1524 tree field_decl = build_decl (FIELD_DECL, field_name, field_type);
1526 DECL_CONTEXT (field_decl) = record_type;
1527 TREE_READONLY (field_decl) = TYPE_READONLY (field_type);
1529 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
1530 byte boundary since GCC cannot handle less-aligned BLKmode bitfields. */
1531 if (packed && TYPE_MODE (field_type) == BLKmode)
1532 DECL_ALIGN (field_decl) = BITS_PER_UNIT;
1534 /* If a size is specified, use it. Otherwise, if the record type is packed
1535 compute a size to use, which may differ from the object's natural size.
1536 We always set a size in this case to trigger the checks for bitfield
1537 creation below, which is typically required when no position has been
1540 size = convert (bitsizetype, size);
1541 else if (packed == 1)
1543 size = rm_size (field_type);
1545 /* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to
1547 if (TREE_CODE (size) == INTEGER_CST
1548 && compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0)
1549 size = round_up (size, BITS_PER_UNIT);
1552 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
1553 specified for two reasons: first if the size differs from the natural
1554 size. Second, if the alignment is insufficient. There are a number of
1555 ways the latter can be true.
1557 We never make a bitfield if the type of the field has a nonconstant size,
1558 because no such entity requiring bitfield operations should reach here.
1560 We do *preventively* make a bitfield when there might be the need for it
1561 but we don't have all the necessary information to decide, as is the case
1562 of a field with no specified position in a packed record.
1564 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
1565 in layout_decl or finish_record_type to clear the bit_field indication if
1566 it is in fact not needed. */
1567 if (addressable >= 0
1569 && TREE_CODE (size) == INTEGER_CST
1570 && TREE_CODE (TYPE_SIZE (field_type)) == INTEGER_CST
1571 && (!tree_int_cst_equal (size, TYPE_SIZE (field_type))
1572 || (pos && !value_factor_p (pos, TYPE_ALIGN (field_type)))
1574 || (TYPE_ALIGN (record_type) != 0
1575 && TYPE_ALIGN (record_type) < TYPE_ALIGN (field_type))))
1577 DECL_BIT_FIELD (field_decl) = 1;
1578 DECL_SIZE (field_decl) = size;
1579 if (!packed && !pos)
1580 DECL_ALIGN (field_decl)
1581 = (TYPE_ALIGN (record_type) != 0
1582 ? MIN (TYPE_ALIGN (record_type), TYPE_ALIGN (field_type))
1583 : TYPE_ALIGN (field_type));
1586 DECL_PACKED (field_decl) = pos ? DECL_BIT_FIELD (field_decl) : packed;
1588 /* Bump the alignment if need be, either for bitfield/packing purposes or
1589 to satisfy the type requirements if no such consideration applies. When
1590 we get the alignment from the type, indicate if this is from an explicit
1591 user request, which prevents stor-layout from lowering it later on. */
1594 = (DECL_BIT_FIELD (field_decl) ? 1
1595 : packed && TYPE_MODE (field_type) != BLKmode ? BITS_PER_UNIT : 0);
1597 if (bit_align > DECL_ALIGN (field_decl))
1598 DECL_ALIGN (field_decl) = bit_align;
1599 else if (!bit_align && TYPE_ALIGN (field_type) > DECL_ALIGN (field_decl))
1601 DECL_ALIGN (field_decl) = TYPE_ALIGN (field_type);
1602 DECL_USER_ALIGN (field_decl) = TYPE_USER_ALIGN (field_type);
1608 /* We need to pass in the alignment the DECL is known to have.
1609 This is the lowest-order bit set in POS, but no more than
1610 the alignment of the record, if one is specified. Note
1611 that an alignment of 0 is taken as infinite. */
1612 unsigned int known_align;
1614 if (host_integerp (pos, 1))
1615 known_align = tree_low_cst (pos, 1) & - tree_low_cst (pos, 1);
1617 known_align = BITS_PER_UNIT;
1619 if (TYPE_ALIGN (record_type)
1620 && (known_align == 0 || known_align > TYPE_ALIGN (record_type)))
1621 known_align = TYPE_ALIGN (record_type);
1623 layout_decl (field_decl, known_align);
1624 SET_DECL_OFFSET_ALIGN (field_decl,
1625 host_integerp (pos, 1) ? BIGGEST_ALIGNMENT
1627 pos_from_bit (&DECL_FIELD_OFFSET (field_decl),
1628 &DECL_FIELD_BIT_OFFSET (field_decl),
1629 DECL_OFFSET_ALIGN (field_decl), pos);
1631 DECL_HAS_REP_P (field_decl) = 1;
1634 /* In addition to what our caller says, claim the field is addressable if we
1635 know that its type is not suitable.
1637 The field may also be "technically" nonaddressable, meaning that even if
1638 we attempt to take the field's address we will actually get the address
1639 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
1640 value we have at this point is not accurate enough, so we don't account
1641 for this here and let finish_record_type decide. */
1642 if (!type_for_nonaliased_component_p (field_type))
1645 DECL_NONADDRESSABLE_P (field_decl) = !addressable;
1650 /* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter,
1651 PARAM_TYPE is its type. READONLY is true if the parameter is
1652 readonly (either an IN parameter or an address of a pass-by-ref
1656 create_param_decl (tree param_name, tree param_type, bool readonly)
1658 tree param_decl = build_decl (PARM_DECL, param_name, param_type);
1660 /* Honor targetm.calls.promote_prototypes(), as not doing so can
1661 lead to various ABI violations. */
1662 if (targetm.calls.promote_prototypes (param_type)
1663 && (TREE_CODE (param_type) == INTEGER_TYPE
1664 || TREE_CODE (param_type) == ENUMERAL_TYPE)
1665 && TYPE_PRECISION (param_type) < TYPE_PRECISION (integer_type_node))
1667 /* We have to be careful about biased types here. Make a subtype
1668 of integer_type_node with the proper biasing. */
1669 if (TREE_CODE (param_type) == INTEGER_TYPE
1670 && TYPE_BIASED_REPRESENTATION_P (param_type))
1673 = copy_type (build_range_type (integer_type_node,
1674 TYPE_MIN_VALUE (param_type),
1675 TYPE_MAX_VALUE (param_type)));
1677 TYPE_BIASED_REPRESENTATION_P (param_type) = 1;
1680 param_type = integer_type_node;
1683 DECL_ARG_TYPE (param_decl) = param_type;
1684 TREE_READONLY (param_decl) = readonly;
1688 /* Given a DECL and ATTR_LIST, process the listed attributes. */
1691 process_attributes (tree decl, struct attrib *attr_list)
1693 for (; attr_list; attr_list = attr_list->next)
1694 switch (attr_list->type)
1696 case ATTR_MACHINE_ATTRIBUTE:
1697 decl_attributes (&decl, tree_cons (attr_list->name, attr_list->args,
1699 ATTR_FLAG_TYPE_IN_PLACE);
1702 case ATTR_LINK_ALIAS:
1703 if (! DECL_EXTERNAL (decl))
1705 TREE_STATIC (decl) = 1;
1706 assemble_alias (decl, attr_list->name);
1710 case ATTR_WEAK_EXTERNAL:
1712 declare_weak (decl);
1714 post_error ("?weak declarations not supported on this target",
1715 attr_list->error_point);
1718 case ATTR_LINK_SECTION:
1719 if (targetm.have_named_sections)
1721 DECL_SECTION_NAME (decl)
1722 = build_string (IDENTIFIER_LENGTH (attr_list->name),
1723 IDENTIFIER_POINTER (attr_list->name));
1724 DECL_COMMON (decl) = 0;
1727 post_error ("?section attributes are not supported for this target",
1728 attr_list->error_point);
1731 case ATTR_LINK_CONSTRUCTOR:
1732 DECL_STATIC_CONSTRUCTOR (decl) = 1;
1733 TREE_USED (decl) = 1;
1736 case ATTR_LINK_DESTRUCTOR:
1737 DECL_STATIC_DESTRUCTOR (decl) = 1;
1738 TREE_USED (decl) = 1;
1743 /* Record a global renaming pointer. */
1746 record_global_renaming_pointer (tree decl)
1748 gcc_assert (DECL_RENAMED_OBJECT (decl));
1749 VEC_safe_push (tree, gc, global_renaming_pointers, decl);
1752 /* Invalidate the global renaming pointers. */
1755 invalidate_global_renaming_pointers (void)
1760 for (i = 0; VEC_iterate(tree, global_renaming_pointers, i, iter); i++)
1761 SET_DECL_RENAMED_OBJECT (iter, NULL_TREE);
1763 VEC_free (tree, gc, global_renaming_pointers);
1766 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
1770 value_factor_p (tree value, HOST_WIDE_INT factor)
1772 if (host_integerp (value, 1))
1773 return tree_low_cst (value, 1) % factor == 0;
1775 if (TREE_CODE (value) == MULT_EXPR)
1776 return (value_factor_p (TREE_OPERAND (value, 0), factor)
1777 || value_factor_p (TREE_OPERAND (value, 1), factor));
1782 /* Given 2 consecutive field decls PREV_FIELD and CURR_FIELD, return true
1783 unless we can prove these 2 fields are laid out in such a way that no gap
1784 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
1785 is the distance in bits between the end of PREV_FIELD and the starting
1786 position of CURR_FIELD. It is ignored if null. */
1789 potential_alignment_gap (tree prev_field, tree curr_field, tree offset)
1791 /* If this is the first field of the record, there cannot be any gap */
1795 /* If the previous field is a union type, then return False: The only
1796 time when such a field is not the last field of the record is when
1797 there are other components at fixed positions after it (meaning there
1798 was a rep clause for every field), in which case we don't want the
1799 alignment constraint to override them. */
1800 if (TREE_CODE (TREE_TYPE (prev_field)) == QUAL_UNION_TYPE)
1803 /* If the distance between the end of prev_field and the beginning of
1804 curr_field is constant, then there is a gap if the value of this
1805 constant is not null. */
1806 if (offset && host_integerp (offset, 1))
1807 return !integer_zerop (offset);
1809 /* If the size and position of the previous field are constant,
1810 then check the sum of this size and position. There will be a gap
1811 iff it is not multiple of the current field alignment. */
1812 if (host_integerp (DECL_SIZE (prev_field), 1)
1813 && host_integerp (bit_position (prev_field), 1))
1814 return ((tree_low_cst (bit_position (prev_field), 1)
1815 + tree_low_cst (DECL_SIZE (prev_field), 1))
1816 % DECL_ALIGN (curr_field) != 0);
1818 /* If both the position and size of the previous field are multiples
1819 of the current field alignment, there cannot be any gap. */
1820 if (value_factor_p (bit_position (prev_field), DECL_ALIGN (curr_field))
1821 && value_factor_p (DECL_SIZE (prev_field), DECL_ALIGN (curr_field)))
1824 /* Fallback, return that there may be a potential gap */
1828 /* Returns a LABEL_DECL node for LABEL_NAME. */
1831 create_label_decl (tree label_name)
1833 tree label_decl = build_decl (LABEL_DECL, label_name, void_type_node);
1835 DECL_CONTEXT (label_decl) = current_function_decl;
1836 DECL_MODE (label_decl) = VOIDmode;
1837 DECL_SOURCE_LOCATION (label_decl) = input_location;
1842 /* Returns a FUNCTION_DECL node. SUBPROG_NAME is the name of the subprogram,
1843 ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE
1844 node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of
1845 PARM_DECL nodes chained through the TREE_CHAIN field).
1847 INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, and ATTR_LIST are used to set the
1848 appropriate fields in the FUNCTION_DECL. GNAT_NODE gives the location. */
1851 create_subprog_decl (tree subprog_name, tree asm_name,
1852 tree subprog_type, tree param_decl_list, bool inline_flag,
1853 bool public_flag, bool extern_flag,
1854 struct attrib *attr_list, Node_Id gnat_node)
1856 tree return_type = TREE_TYPE (subprog_type);
1857 tree subprog_decl = build_decl (FUNCTION_DECL, subprog_name, subprog_type);
1859 /* If this is a function nested inside an inlined external function, it
1860 means we aren't going to compile the outer function unless it is
1861 actually inlined, so do the same for us. */
1862 if (current_function_decl && DECL_INLINE (current_function_decl)
1863 && DECL_EXTERNAL (current_function_decl))
1866 DECL_EXTERNAL (subprog_decl) = extern_flag;
1867 TREE_PUBLIC (subprog_decl) = public_flag;
1868 TREE_STATIC (subprog_decl) = 1;
1869 TREE_READONLY (subprog_decl) = TYPE_READONLY (subprog_type);
1870 TREE_THIS_VOLATILE (subprog_decl) = TYPE_VOLATILE (subprog_type);
1871 TREE_SIDE_EFFECTS (subprog_decl) = TYPE_VOLATILE (subprog_type);
1872 DECL_ARGUMENTS (subprog_decl) = param_decl_list;
1873 DECL_RESULT (subprog_decl) = build_decl (RESULT_DECL, 0, return_type);
1874 DECL_ARTIFICIAL (DECL_RESULT (subprog_decl)) = 1;
1875 DECL_IGNORED_P (DECL_RESULT (subprog_decl)) = 1;
1877 /* TREE_ADDRESSABLE is set on the result type to request the use of the
1878 target by-reference return mechanism. This is not supported all the
1879 way down to RTL expansion with GCC 4, which ICEs on temporary creation
1880 attempts with such a type and expects DECL_BY_REFERENCE to be set on
1881 the RESULT_DECL instead - see gnat_genericize for more details. */
1882 if (TREE_ADDRESSABLE (TREE_TYPE (DECL_RESULT (subprog_decl))))
1884 tree result_decl = DECL_RESULT (subprog_decl);
1886 TREE_ADDRESSABLE (TREE_TYPE (result_decl)) = 0;
1887 DECL_BY_REFERENCE (result_decl) = 1;
1891 DECL_DECLARED_INLINE_P (subprog_decl) = 1;
1894 SET_DECL_ASSEMBLER_NAME (subprog_decl, asm_name);
1896 process_attributes (subprog_decl, attr_list);
1898 /* Add this decl to the current binding level. */
1899 gnat_pushdecl (subprog_decl, gnat_node);
1901 /* Output the assembler code and/or RTL for the declaration. */
1902 rest_of_decl_compilation (subprog_decl, global_bindings_p (), 0);
1904 return subprog_decl;
1907 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
1908 body. This routine needs to be invoked before processing the declarations
1909 appearing in the subprogram. */
1912 begin_subprog_body (tree subprog_decl)
1916 current_function_decl = subprog_decl;
1917 announce_function (subprog_decl);
1919 /* Enter a new binding level and show that all the parameters belong to
1922 for (param_decl = DECL_ARGUMENTS (subprog_decl); param_decl;
1923 param_decl = TREE_CHAIN (param_decl))
1924 DECL_CONTEXT (param_decl) = subprog_decl;
1926 make_decl_rtl (subprog_decl);
1928 /* We handle pending sizes via the elaboration of types, so we don't need to
1929 save them. This causes them to be marked as part of the outer function
1930 and then discarded. */
1931 get_pending_sizes ();
1935 /* Helper for the genericization callback. Return a dereference of VAL
1936 if it is of a reference type. */
1939 convert_from_reference (tree val)
1941 tree value_type, ref;
1943 if (TREE_CODE (TREE_TYPE (val)) != REFERENCE_TYPE)
1946 value_type = TREE_TYPE (TREE_TYPE (val));
1947 ref = build1 (INDIRECT_REF, value_type, val);
1949 /* See if what we reference is CONST or VOLATILE, which requires
1950 looking into array types to get to the component type. */
1952 while (TREE_CODE (value_type) == ARRAY_TYPE)
1953 value_type = TREE_TYPE (value_type);
1956 = (TYPE_QUALS (value_type) & TYPE_QUAL_CONST);
1957 TREE_THIS_VOLATILE (ref)
1958 = (TYPE_QUALS (value_type) & TYPE_QUAL_VOLATILE);
1960 TREE_SIDE_EFFECTS (ref)
1961 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (val));
1966 /* Helper for the genericization callback. Returns true if T denotes
1967 a RESULT_DECL with DECL_BY_REFERENCE set. */
1970 is_byref_result (tree t)
1972 return (TREE_CODE (t) == RESULT_DECL && DECL_BY_REFERENCE (t));
1976 /* Tree walking callback for gnat_genericize. Currently ...
1978 o Adjust references to the function's DECL_RESULT if it is marked
1979 DECL_BY_REFERENCE and so has had its type turned into a reference
1980 type at the end of the function compilation. */
1983 gnat_genericize_r (tree *stmt_p, int *walk_subtrees, void *data)
1985 /* This implementation is modeled after what the C++ front-end is
1986 doing, basis of the downstream passes behavior. */
1988 tree stmt = *stmt_p;
1989 struct pointer_set_t *p_set = (struct pointer_set_t*) data;
1991 /* If we have a direct mention of the result decl, dereference. */
1992 if (is_byref_result (stmt))
1994 *stmt_p = convert_from_reference (stmt);
1999 /* Otherwise, no need to walk the the same tree twice. */
2000 if (pointer_set_contains (p_set, stmt))
2006 /* If we are taking the address of what now is a reference, just get the
2008 if (TREE_CODE (stmt) == ADDR_EXPR
2009 && is_byref_result (TREE_OPERAND (stmt, 0)))
2011 *stmt_p = convert (TREE_TYPE (stmt), TREE_OPERAND (stmt, 0));
2015 /* Don't dereference an by-reference RESULT_DECL inside a RETURN_EXPR. */
2016 else if (TREE_CODE (stmt) == RETURN_EXPR
2017 && TREE_OPERAND (stmt, 0)
2018 && is_byref_result (TREE_OPERAND (stmt, 0)))
2021 /* Don't look inside trees that cannot embed references of interest. */
2022 else if (IS_TYPE_OR_DECL_P (stmt))
2025 pointer_set_insert (p_set, *stmt_p);
2030 /* Perform lowering of Ada trees to GENERIC. In particular:
2032 o Turn a DECL_BY_REFERENCE RESULT_DECL into a real by-reference decl
2033 and adjust all the references to this decl accordingly. */
2036 gnat_genericize (tree fndecl)
2038 /* Prior to GCC 4, an explicit By_Reference result mechanism for a function
2039 was handled by simply setting TREE_ADDRESSABLE on the result type.
2040 Everything required to actually pass by invisible ref using the target
2041 mechanism (e.g. extra parameter) was handled at RTL expansion time.
2043 This doesn't work with GCC 4 any more for several reasons. First, the
2044 gimplification process might need the creation of temporaries of this
2045 type, and the gimplifier ICEs on such attempts. Second, the middle-end
2046 now relies on a different attribute for such cases (DECL_BY_REFERENCE on
2047 RESULT/PARM_DECLs), and expects the user invisible by-reference-ness to
2048 be explicitely accounted for by the front-end in the function body.
2050 We achieve the complete transformation in two steps:
2052 1/ create_subprog_decl performs early attribute tweaks: it clears
2053 TREE_ADDRESSABLE from the result type and sets DECL_BY_REFERENCE on
2054 the result decl. The former ensures that the bit isn't set in the GCC
2055 tree saved for the function, so prevents ICEs on temporary creation.
2056 The latter we use here to trigger the rest of the processing.
2058 2/ This function performs the type transformation on the result decl
2059 and adjusts all the references to this decl from the function body
2062 Clearing TREE_ADDRESSABLE from the type differs from the C++ front-end
2063 strategy, which escapes the gimplifier temporary creation issues by
2064 creating it's own temporaries using TARGET_EXPR nodes. Our way relies
2065 on simple specific support code in aggregate_value_p to look at the
2066 target function result decl explicitely. */
2068 struct pointer_set_t *p_set;
2069 tree decl_result = DECL_RESULT (fndecl);
2071 if (!DECL_BY_REFERENCE (decl_result))
2074 /* Make the DECL_RESULT explicitely by-reference and adjust all the
2075 occurrences in the function body using the common tree-walking facility.
2076 We want to see every occurrence of the result decl to adjust the
2077 referencing tree, so need to use our own pointer set to control which
2078 trees should be visited again or not. */
2080 p_set = pointer_set_create ();
2082 TREE_TYPE (decl_result) = build_reference_type (TREE_TYPE (decl_result));
2083 TREE_ADDRESSABLE (decl_result) = 0;
2084 relayout_decl (decl_result);
2086 walk_tree (&DECL_SAVED_TREE (fndecl), gnat_genericize_r, p_set, NULL);
2088 pointer_set_destroy (p_set);
2091 /* Finish the definition of the current subprogram and compile it all the way
2092 to assembler language output. BODY is the tree corresponding to
2096 end_subprog_body (tree body)
2098 tree fndecl = current_function_decl;
2100 /* Mark the BLOCK for this level as being for this function and pop the
2101 level. Since the vars in it are the parameters, clear them. */
2102 BLOCK_VARS (current_binding_level->block) = 0;
2103 BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl;
2104 DECL_INITIAL (fndecl) = current_binding_level->block;
2107 /* Deal with inline. If declared inline or we should default to inline,
2108 set the flag in the decl. */
2109 DECL_INLINE (fndecl)
2110 = DECL_DECLARED_INLINE_P (fndecl) || flag_inline_trees == 2;
2112 /* We handle pending sizes via the elaboration of types, so we don't
2113 need to save them. */
2114 get_pending_sizes ();
2116 /* Mark the RESULT_DECL as being in this subprogram. */
2117 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl;
2119 DECL_SAVED_TREE (fndecl) = body;
2121 current_function_decl = DECL_CONTEXT (fndecl);
2124 /* We cannot track the location of errors past this point. */
2125 error_gnat_node = Empty;
2127 /* If we're only annotating types, don't actually compile this function. */
2128 if (type_annotate_only)
2131 /* Perform the required pre-gimplfication transformations on the tree. */
2132 gnat_genericize (fndecl);
2134 /* We do different things for nested and non-nested functions.
2135 ??? This should be in cgraph. */
2136 if (!DECL_CONTEXT (fndecl))
2138 gnat_gimplify_function (fndecl);
2139 cgraph_finalize_function (fndecl, false);
2142 /* Register this function with cgraph just far enough to get it
2143 added to our parent's nested function list. */
2144 (void) cgraph_node (fndecl);
2147 /* Convert FNDECL's code to GIMPLE and handle any nested functions. */
2150 gnat_gimplify_function (tree fndecl)
2152 struct cgraph_node *cgn;
2154 dump_function (TDI_original, fndecl);
2155 gimplify_function_tree (fndecl);
2156 dump_function (TDI_generic, fndecl);
2158 /* Convert all nested functions to GIMPLE now. We do things in this order
2159 so that items like VLA sizes are expanded properly in the context of the
2160 correct function. */
2161 cgn = cgraph_node (fndecl);
2162 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
2163 gnat_gimplify_function (cgn->decl);
2168 gnat_builtin_function (tree decl)
2170 gnat_pushdecl (decl, Empty);
2174 /* Handle a "const" attribute; arguments as in
2175 struct attribute_spec.handler. */
2178 handle_const_attribute (tree *node, tree ARG_UNUSED (name),
2179 tree ARG_UNUSED (args), int ARG_UNUSED (flags),
2182 if (TREE_CODE (*node) == FUNCTION_DECL)
2183 TREE_READONLY (*node) = 1;
2185 *no_add_attrs = true;
2190 /* Handle a "nothrow" attribute; arguments as in
2191 struct attribute_spec.handler. */
2194 handle_nothrow_attribute (tree *node, tree ARG_UNUSED (name),
2195 tree ARG_UNUSED (args), int ARG_UNUSED (flags),
2198 if (TREE_CODE (*node) == FUNCTION_DECL)
2199 TREE_NOTHROW (*node) = 1;
2201 *no_add_attrs = true;
2206 /* Return an integer type with the number of bits of precision given by
2207 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
2208 it is a signed type. */
2211 gnat_type_for_size (unsigned precision, int unsignedp)
2216 if (precision <= 2 * MAX_BITS_PER_WORD
2217 && signed_and_unsigned_types[precision][unsignedp])
2218 return signed_and_unsigned_types[precision][unsignedp];
2221 t = make_unsigned_type (precision);
2223 t = make_signed_type (precision);
2225 if (precision <= 2 * MAX_BITS_PER_WORD)
2226 signed_and_unsigned_types[precision][unsignedp] = t;
2230 sprintf (type_name, "%sSIGNED_%d", unsignedp ? "UN" : "", precision);
2231 TYPE_NAME (t) = get_identifier (type_name);
2237 /* Likewise for floating-point types. */
2240 float_type_for_precision (int precision, enum machine_mode mode)
2245 if (float_types[(int) mode])
2246 return float_types[(int) mode];
2248 float_types[(int) mode] = t = make_node (REAL_TYPE);
2249 TYPE_PRECISION (t) = precision;
2252 gcc_assert (TYPE_MODE (t) == mode);
2255 sprintf (type_name, "FLOAT_%d", precision);
2256 TYPE_NAME (t) = get_identifier (type_name);
2262 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
2263 an unsigned type; otherwise a signed type is returned. */
2266 gnat_type_for_mode (enum machine_mode mode, int unsignedp)
2268 if (mode == BLKmode)
2270 else if (mode == VOIDmode)
2271 return void_type_node;
2272 else if (COMPLEX_MODE_P (mode))
2274 else if (SCALAR_FLOAT_MODE_P (mode))
2275 return float_type_for_precision (GET_MODE_PRECISION (mode), mode);
2276 else if (SCALAR_INT_MODE_P (mode))
2277 return gnat_type_for_size (GET_MODE_BITSIZE (mode), unsignedp);
2282 /* Return the unsigned version of a TYPE_NODE, a scalar type. */
2285 gnat_unsigned_type (tree type_node)
2287 tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 1);
2289 if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
2291 type = copy_node (type);
2292 TREE_TYPE (type) = type_node;
2294 else if (TREE_TYPE (type_node)
2295 && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
2296 && TYPE_MODULAR_P (TREE_TYPE (type_node)))
2298 type = copy_node (type);
2299 TREE_TYPE (type) = TREE_TYPE (type_node);
2305 /* Return the signed version of a TYPE_NODE, a scalar type. */
2308 gnat_signed_type (tree type_node)
2310 tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 0);
2312 if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
2314 type = copy_node (type);
2315 TREE_TYPE (type) = type_node;
2317 else if (TREE_TYPE (type_node)
2318 && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
2319 && TYPE_MODULAR_P (TREE_TYPE (type_node)))
2321 type = copy_node (type);
2322 TREE_TYPE (type) = TREE_TYPE (type_node);
2329 /* EXP is an expression for the size of an object. If this size contains
2330 discriminant references, replace them with the maximum (if MAX_P) or
2331 minimum (if !MAX_P) possible value of the discriminant. */
2334 max_size (tree exp, bool max_p)
2336 enum tree_code code = TREE_CODE (exp);
2337 tree type = TREE_TYPE (exp);
2339 switch (TREE_CODE_CLASS (code))
2341 case tcc_declaration:
2346 if (code == CALL_EXPR)
2349 int i, n = call_expr_nargs (exp);
2352 argarray = (tree *) alloca (n * sizeof (tree));
2353 for (i = 0; i < n; i++)
2354 argarray[i] = max_size (CALL_EXPR_ARG (exp, i), max_p);
2355 return build_call_array (type, CALL_EXPR_FN (exp), n, argarray);
2360 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
2361 modify. Otherwise, we treat it like a variable. */
2362 if (!CONTAINS_PLACEHOLDER_P (exp))
2365 type = TREE_TYPE (TREE_OPERAND (exp, 1));
2367 max_size (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type), true);
2369 case tcc_comparison:
2370 return max_p ? size_one_node : size_zero_node;
2374 case tcc_expression:
2375 switch (TREE_CODE_LENGTH (code))
2378 if (code == NON_LVALUE_EXPR)
2379 return max_size (TREE_OPERAND (exp, 0), max_p);
2382 fold_build1 (code, type,
2383 max_size (TREE_OPERAND (exp, 0),
2384 code == NEGATE_EXPR ? !max_p : max_p));
2387 if (code == COMPOUND_EXPR)
2388 return max_size (TREE_OPERAND (exp, 1), max_p);
2390 /* Calculate "(A ? B : C) - D" as "A ? B - D : C - D" which
2391 may provide a tighter bound on max_size. */
2392 if (code == MINUS_EXPR
2393 && TREE_CODE (TREE_OPERAND (exp, 0)) == COND_EXPR)
2395 tree lhs = fold_build2 (MINUS_EXPR, type,
2396 TREE_OPERAND (TREE_OPERAND (exp, 0), 1),
2397 TREE_OPERAND (exp, 1));
2398 tree rhs = fold_build2 (MINUS_EXPR, type,
2399 TREE_OPERAND (TREE_OPERAND (exp, 0), 2),
2400 TREE_OPERAND (exp, 1));
2401 return fold_build2 (max_p ? MAX_EXPR : MIN_EXPR, type,
2402 max_size (lhs, max_p),
2403 max_size (rhs, max_p));
2407 tree lhs = max_size (TREE_OPERAND (exp, 0), max_p);
2408 tree rhs = max_size (TREE_OPERAND (exp, 1),
2409 code == MINUS_EXPR ? !max_p : max_p);
2411 /* Special-case wanting the maximum value of a MIN_EXPR.
2412 In that case, if one side overflows, return the other.
2413 sizetype is signed, but we know sizes are non-negative.
2414 Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
2415 overflowing or the maximum possible value and the RHS
2419 && TREE_CODE (rhs) == INTEGER_CST
2420 && TREE_OVERFLOW (rhs))
2424 && TREE_CODE (lhs) == INTEGER_CST
2425 && TREE_OVERFLOW (lhs))
2427 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
2428 && ((TREE_CODE (lhs) == INTEGER_CST
2429 && TREE_OVERFLOW (lhs))
2430 || operand_equal_p (lhs, TYPE_MAX_VALUE (type), 0))
2431 && !TREE_CONSTANT (rhs))
2434 return fold_build2 (code, type, lhs, rhs);
2438 if (code == SAVE_EXPR)
2440 else if (code == COND_EXPR)
2441 return fold_build2 (max_p ? MAX_EXPR : MIN_EXPR, type,
2442 max_size (TREE_OPERAND (exp, 1), max_p),
2443 max_size (TREE_OPERAND (exp, 2), max_p));
2446 /* Other tree classes cannot happen. */
2454 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
2455 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
2456 Return a constructor for the template. */
2459 build_template (tree template_type, tree array_type, tree expr)
2461 tree template_elts = NULL_TREE;
2462 tree bound_list = NULL_TREE;
2465 if (TREE_CODE (array_type) == RECORD_TYPE
2466 && (TYPE_IS_PADDING_P (array_type)
2467 || TYPE_JUSTIFIED_MODULAR_P (array_type)))
2468 array_type = TREE_TYPE (TYPE_FIELDS (array_type));
2470 if (TREE_CODE (array_type) == ARRAY_TYPE
2471 || (TREE_CODE (array_type) == INTEGER_TYPE
2472 && TYPE_HAS_ACTUAL_BOUNDS_P (array_type)))
2473 bound_list = TYPE_ACTUAL_BOUNDS (array_type);
2475 /* First make the list for a CONSTRUCTOR for the template. Go down the
2476 field list of the template instead of the type chain because this
2477 array might be an Ada array of arrays and we can't tell where the
2478 nested arrays stop being the underlying object. */
2480 for (field = TYPE_FIELDS (template_type); field;
2482 ? (bound_list = TREE_CHAIN (bound_list))
2483 : (array_type = TREE_TYPE (array_type))),
2484 field = TREE_CHAIN (TREE_CHAIN (field)))
2486 tree bounds, min, max;
2488 /* If we have a bound list, get the bounds from there. Likewise
2489 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
2490 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
2491 This will give us a maximum range. */
2493 bounds = TREE_VALUE (bound_list);
2494 else if (TREE_CODE (array_type) == ARRAY_TYPE)
2495 bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type));
2496 else if (expr && TREE_CODE (expr) == PARM_DECL
2497 && DECL_BY_COMPONENT_PTR_P (expr))
2498 bounds = TREE_TYPE (field);
2502 min = convert (TREE_TYPE (field), TYPE_MIN_VALUE (bounds));
2503 max = convert (TREE_TYPE (TREE_CHAIN (field)), TYPE_MAX_VALUE (bounds));
2505 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
2506 substitute it from OBJECT. */
2507 min = SUBSTITUTE_PLACEHOLDER_IN_EXPR (min, expr);
2508 max = SUBSTITUTE_PLACEHOLDER_IN_EXPR (max, expr);
2510 template_elts = tree_cons (TREE_CHAIN (field), max,
2511 tree_cons (field, min, template_elts));
2514 return gnat_build_constructor (template_type, nreverse (template_elts));
2517 /* Build a VMS descriptor from a Mechanism_Type, which must specify
2518 a descriptor type, and the GCC type of an object. Each FIELD_DECL
2519 in the type contains in its DECL_INITIAL the expression to use when
2520 a constructor is made for the type. GNAT_ENTITY is an entity used
2521 to print out an error message if the mechanism cannot be applied to
2522 an object of that type and also for the name. */
2525 build_vms_descriptor (tree type, Mechanism_Type mech, Entity_Id gnat_entity)
2527 tree record_type = make_node (RECORD_TYPE);
2528 tree pointer32_type;
2529 tree field_list = 0;
2538 /* If TYPE is an unconstrained array, use the underlying array type. */
2539 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
2540 type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type))));
2542 /* If this is an array, compute the number of dimensions in the array,
2543 get the index types, and point to the inner type. */
2544 if (TREE_CODE (type) != ARRAY_TYPE)
2547 for (ndim = 1, inner_type = type;
2548 TREE_CODE (TREE_TYPE (inner_type)) == ARRAY_TYPE
2549 && TYPE_MULTI_ARRAY_P (TREE_TYPE (inner_type));
2550 ndim++, inner_type = TREE_TYPE (inner_type))
2553 idx_arr = (tree *) alloca (ndim * sizeof (tree));
2555 if (mech != By_Descriptor_NCA
2556 && TREE_CODE (type) == ARRAY_TYPE && TYPE_CONVENTION_FORTRAN_P (type))
2557 for (i = ndim - 1, inner_type = type;
2559 i--, inner_type = TREE_TYPE (inner_type))
2560 idx_arr[i] = TYPE_DOMAIN (inner_type);
2562 for (i = 0, inner_type = type;
2564 i++, inner_type = TREE_TYPE (inner_type))
2565 idx_arr[i] = TYPE_DOMAIN (inner_type);
2567 /* Now get the DTYPE value. */
2568 switch (TREE_CODE (type))
2572 if (TYPE_VAX_FLOATING_POINT_P (type))
2573 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2586 switch (GET_MODE_BITSIZE (TYPE_MODE (type)))
2589 dtype = TYPE_UNSIGNED (type) ? 2 : 6;
2592 dtype = TYPE_UNSIGNED (type) ? 3 : 7;
2595 dtype = TYPE_UNSIGNED (type) ? 4 : 8;
2598 dtype = TYPE_UNSIGNED (type) ? 5 : 9;
2601 dtype = TYPE_UNSIGNED (type) ? 25 : 26;
2607 dtype = GET_MODE_BITSIZE (TYPE_MODE (type)) == 32 ? 52 : 53;
2611 if (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE
2612 && TYPE_VAX_FLOATING_POINT_P (type))
2613 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2625 dtype = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) == 32 ? 54: 55;
2636 /* Get the CLASS value. */
2639 case By_Descriptor_A:
2642 case By_Descriptor_NCA:
2645 case By_Descriptor_SB:
2649 case By_Descriptor_S:
2655 /* Make the type for a descriptor for VMS. The first four fields
2656 are the same for all types. */
2659 = chainon (field_list,
2660 make_descriptor_field
2661 ("LENGTH", gnat_type_for_size (16, 1), record_type,
2662 size_in_bytes (mech == By_Descriptor_A ? inner_type : type)));
2664 field_list = chainon (field_list,
2665 make_descriptor_field ("DTYPE",
2666 gnat_type_for_size (8, 1),
2667 record_type, size_int (dtype)));
2668 field_list = chainon (field_list,
2669 make_descriptor_field ("CLASS",
2670 gnat_type_for_size (8, 1),
2671 record_type, size_int (class)));
2673 /* Of course this will crash at run-time if the address space is not
2674 within the low 32 bits, but there is nothing else we can do. */
2675 pointer32_type = build_pointer_type_for_mode (type, SImode, false);
2678 = chainon (field_list,
2679 make_descriptor_field
2680 ("POINTER", pointer32_type, record_type,
2681 build_unary_op (ADDR_EXPR,
2683 build0 (PLACEHOLDER_EXPR, type))));
2688 case By_Descriptor_S:
2691 case By_Descriptor_SB:
2693 = chainon (field_list,
2694 make_descriptor_field
2695 ("SB_L1", gnat_type_for_size (32, 1), record_type,
2696 TREE_CODE (type) == ARRAY_TYPE
2697 ? TYPE_MIN_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2699 = chainon (field_list,
2700 make_descriptor_field
2701 ("SB_U1", gnat_type_for_size (32, 1), record_type,
2702 TREE_CODE (type) == ARRAY_TYPE
2703 ? TYPE_MAX_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2706 case By_Descriptor_A:
2707 case By_Descriptor_NCA:
2708 field_list = chainon (field_list,
2709 make_descriptor_field ("SCALE",
2710 gnat_type_for_size (8, 1),
2714 field_list = chainon (field_list,
2715 make_descriptor_field ("DIGITS",
2716 gnat_type_for_size (8, 1),
2721 = chainon (field_list,
2722 make_descriptor_field
2723 ("AFLAGS", gnat_type_for_size (8, 1), record_type,
2724 size_int (mech == By_Descriptor_NCA
2726 /* Set FL_COLUMN, FL_COEFF, and FL_BOUNDS. */
2727 : (TREE_CODE (type) == ARRAY_TYPE
2728 && TYPE_CONVENTION_FORTRAN_P (type)
2731 field_list = chainon (field_list,
2732 make_descriptor_field ("DIMCT",
2733 gnat_type_for_size (8, 1),
2737 field_list = chainon (field_list,
2738 make_descriptor_field ("ARSIZE",
2739 gnat_type_for_size (32, 1),
2741 size_in_bytes (type)));
2743 /* Now build a pointer to the 0,0,0... element. */
2744 tem = build0 (PLACEHOLDER_EXPR, type);
2745 for (i = 0, inner_type = type; i < ndim;
2746 i++, inner_type = TREE_TYPE (inner_type))
2747 tem = build4 (ARRAY_REF, TREE_TYPE (inner_type), tem,
2748 convert (TYPE_DOMAIN (inner_type), size_zero_node),
2749 NULL_TREE, NULL_TREE);
2752 = chainon (field_list,
2753 make_descriptor_field
2755 build_pointer_type_for_mode (inner_type, SImode, false),
2758 build_pointer_type_for_mode (inner_type, SImode,
2762 /* Next come the addressing coefficients. */
2763 tem = size_one_node;
2764 for (i = 0; i < ndim; i++)
2768 = size_binop (MULT_EXPR, tem,
2769 size_binop (PLUS_EXPR,
2770 size_binop (MINUS_EXPR,
2771 TYPE_MAX_VALUE (idx_arr[i]),
2772 TYPE_MIN_VALUE (idx_arr[i])),
2775 fname[0] = (mech == By_Descriptor_NCA ? 'S' : 'M');
2776 fname[1] = '0' + i, fname[2] = 0;
2778 = chainon (field_list,
2779 make_descriptor_field (fname,
2780 gnat_type_for_size (32, 1),
2781 record_type, idx_length));
2783 if (mech == By_Descriptor_NCA)
2787 /* Finally here are the bounds. */
2788 for (i = 0; i < ndim; i++)
2792 fname[0] = 'L', fname[1] = '0' + i, fname[2] = 0;
2794 = chainon (field_list,
2795 make_descriptor_field
2796 (fname, gnat_type_for_size (32, 1), record_type,
2797 TYPE_MIN_VALUE (idx_arr[i])));
2801 = chainon (field_list,
2802 make_descriptor_field
2803 (fname, gnat_type_for_size (32, 1), record_type,
2804 TYPE_MAX_VALUE (idx_arr[i])));
2809 post_error ("unsupported descriptor type for &", gnat_entity);
2812 finish_record_type (record_type, field_list, 0, true);
2813 create_type_decl (create_concat_name (gnat_entity, "DESC"), record_type,
2814 NULL, true, false, gnat_entity);
2819 /* Utility routine for above code to make a field. */
2822 make_descriptor_field (const char *name, tree type,
2823 tree rec_type, tree initial)
2826 = create_field_decl (get_identifier (name), type, rec_type, 0, 0, 0, 0);
2828 DECL_INITIAL (field) = initial;
2832 /* Convert GNU_EXPR, a pointer to a VMS descriptor, to GNU_TYPE, a regular
2833 pointer or fat pointer type. GNAT_SUBPROG is the subprogram to which
2834 the VMS descriptor is passed. */
2837 convert_vms_descriptor (tree gnu_type, tree gnu_expr, Entity_Id gnat_subprog)
2839 tree desc_type = TREE_TYPE (TREE_TYPE (gnu_expr));
2840 tree desc = build1 (INDIRECT_REF, desc_type, gnu_expr);
2841 /* The CLASS field is the 3rd field in the descriptor. */
2842 tree class = TREE_CHAIN (TREE_CHAIN (TYPE_FIELDS (desc_type)));
2843 /* The POINTER field is the 4th field in the descriptor. */
2844 tree pointer = TREE_CHAIN (class);
2846 /* Retrieve the value of the POINTER field. */
2848 = build3 (COMPONENT_REF, TREE_TYPE (pointer), desc, pointer, NULL_TREE);
2850 if (POINTER_TYPE_P (gnu_type))
2851 return convert (gnu_type, gnu_expr);
2853 else if (TYPE_FAT_POINTER_P (gnu_type))
2855 tree p_array_type = TREE_TYPE (TYPE_FIELDS (gnu_type));
2856 tree p_bounds_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_type)));
2857 tree template_type = TREE_TYPE (p_bounds_type);
2858 tree min_field = TYPE_FIELDS (template_type);
2859 tree max_field = TREE_CHAIN (TYPE_FIELDS (template_type));
2860 tree template, template_addr, aflags, dimct, t, u;
2861 /* See the head comment of build_vms_descriptor. */
2862 int iclass = TREE_INT_CST_LOW (DECL_INITIAL (class));
2864 /* Convert POINTER to the type of the P_ARRAY field. */
2865 gnu_expr = convert (p_array_type, gnu_expr);
2869 case 1: /* Class S */
2870 case 15: /* Class SB */
2871 /* Build {1, LENGTH} template; LENGTH is the 1st field. */
2872 t = TYPE_FIELDS (desc_type);
2873 t = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
2874 t = tree_cons (min_field,
2875 convert (TREE_TYPE (min_field), integer_one_node),
2876 tree_cons (max_field,
2877 convert (TREE_TYPE (max_field), t),
2879 template = gnat_build_constructor (template_type, t);
2880 template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template);
2882 /* For class S, we are done. */
2886 /* Test that we really have a SB descriptor, like DEC Ada. */
2887 t = build3 (COMPONENT_REF, TREE_TYPE (class), desc, class, NULL);
2888 u = convert (TREE_TYPE (class), DECL_INITIAL (class));
2889 u = build_binary_op (EQ_EXPR, integer_type_node, t, u);
2890 /* If so, there is already a template in the descriptor and
2891 it is located right after the POINTER field. */
2892 t = TREE_CHAIN (pointer);
2893 template = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
2894 /* Otherwise use the {1, LENGTH} template we build above. */
2895 template_addr = build3 (COND_EXPR, p_bounds_type, u,
2896 build_unary_op (ADDR_EXPR, p_bounds_type,
2901 case 4: /* Class A */
2902 /* The AFLAGS field is the 7th field in the descriptor. */
2903 t = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (pointer)));
2904 aflags = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
2905 /* The DIMCT field is the 8th field in the descriptor. */
2907 dimct = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
2908 /* Raise CONSTRAINT_ERROR if either more than 1 dimension
2909 or FL_COEFF or FL_BOUNDS not set. */
2910 u = build_int_cst (TREE_TYPE (aflags), 192);
2911 u = build_binary_op (TRUTH_OR_EXPR, integer_type_node,
2912 build_binary_op (NE_EXPR, integer_type_node,
2914 convert (TREE_TYPE (dimct),
2916 build_binary_op (NE_EXPR, integer_type_node,
2917 build2 (BIT_AND_EXPR,
2921 add_stmt (build3 (COND_EXPR, void_type_node, u,
2922 build_call_raise (CE_Length_Check_Failed, Empty,
2923 N_Raise_Constraint_Error),
2925 /* There is already a template in the descriptor and it is
2926 located at the start of block 3 (12th field). */
2927 t = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (t))));
2928 template = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
2929 template_addr = build_unary_op (ADDR_EXPR, p_bounds_type, template);
2932 case 10: /* Class NCA */
2934 post_error ("unsupported descriptor type for &", gnat_subprog);
2935 template_addr = integer_zero_node;
2939 /* Build the fat pointer in the form of a constructor. */
2940 t = tree_cons (TYPE_FIELDS (gnu_type), gnu_expr,
2941 tree_cons (TREE_CHAIN (TYPE_FIELDS (gnu_type)),
2942 template_addr, NULL_TREE));
2943 return gnat_build_constructor (gnu_type, t);
2950 /* Build a stub for the subprogram specified by the GCC tree GNU_SUBPROG
2951 and the GNAT node GNAT_SUBPROG. */
2954 build_function_stub (tree gnu_subprog, Entity_Id gnat_subprog)
2956 tree gnu_subprog_type, gnu_subprog_addr, gnu_subprog_call;
2957 tree gnu_stub_param, gnu_param_list, gnu_arg_types, gnu_param;
2958 tree gnu_stub_decl = DECL_FUNCTION_STUB (gnu_subprog);
2961 gnu_subprog_type = TREE_TYPE (gnu_subprog);
2962 gnu_param_list = NULL_TREE;
2964 begin_subprog_body (gnu_stub_decl);
2967 start_stmt_group ();
2969 /* Loop over the parameters of the stub and translate any of them
2970 passed by descriptor into a by reference one. */
2971 for (gnu_stub_param = DECL_ARGUMENTS (gnu_stub_decl),
2972 gnu_arg_types = TYPE_ARG_TYPES (gnu_subprog_type);
2974 gnu_stub_param = TREE_CHAIN (gnu_stub_param),
2975 gnu_arg_types = TREE_CHAIN (gnu_arg_types))
2977 if (DECL_BY_DESCRIPTOR_P (gnu_stub_param))
2978 gnu_param = convert_vms_descriptor (TREE_VALUE (gnu_arg_types),
2979 gnu_stub_param, gnat_subprog);
2981 gnu_param = gnu_stub_param;
2983 gnu_param_list = tree_cons (NULL_TREE, gnu_param, gnu_param_list);
2986 gnu_body = end_stmt_group ();
2988 /* Invoke the internal subprogram. */
2989 gnu_subprog_addr = build1 (ADDR_EXPR, build_pointer_type (gnu_subprog_type),
2991 gnu_subprog_call = build3 (CALL_EXPR, TREE_TYPE (gnu_subprog_type),
2992 gnu_subprog_addr, nreverse (gnu_param_list),
2995 /* Propagate the return value, if any. */
2996 if (VOID_TYPE_P (TREE_TYPE (gnu_subprog_type)))
2997 append_to_statement_list (gnu_subprog_call, &gnu_body);
2999 append_to_statement_list (build_return_expr (DECL_RESULT (gnu_stub_decl),
3005 allocate_struct_function (gnu_stub_decl, false);
3006 end_subprog_body (gnu_body);
3009 /* Build a type to be used to represent an aliased object whose nominal
3010 type is an unconstrained array. This consists of a RECORD_TYPE containing
3011 a field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an
3012 ARRAY_TYPE. If ARRAY_TYPE is that of the unconstrained array, this
3013 is used to represent an arbitrary unconstrained object. Use NAME
3014 as the name of the record. */
3017 build_unc_object_type (tree template_type, tree object_type, tree name)
3019 tree type = make_node (RECORD_TYPE);
3020 tree template_field = create_field_decl (get_identifier ("BOUNDS"),
3021 template_type, type, 0, 0, 0, 1);
3022 tree array_field = create_field_decl (get_identifier ("ARRAY"), object_type,
3025 TYPE_NAME (type) = name;
3026 TYPE_CONTAINS_TEMPLATE_P (type) = 1;
3027 finish_record_type (type,
3028 chainon (chainon (NULL_TREE, template_field),
3035 /* Same, taking a thin or fat pointer type instead of a template type. */
3038 build_unc_object_type_from_ptr (tree thin_fat_ptr_type, tree object_type,
3043 gcc_assert (TYPE_FAT_OR_THIN_POINTER_P (thin_fat_ptr_type));
3046 = (TYPE_FAT_POINTER_P (thin_fat_ptr_type)
3047 ? TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (thin_fat_ptr_type))))
3048 : TREE_TYPE (TYPE_FIELDS (TREE_TYPE (thin_fat_ptr_type))));
3049 return build_unc_object_type (template_type, object_type, name);
3052 /* Shift the component offsets within an unconstrained object TYPE to make it
3053 suitable for use as a designated type for thin pointers. */
3056 shift_unc_components_for_thin_pointers (tree type)
3058 /* Thin pointer values designate the ARRAY data of an unconstrained object,
3059 allocated past the BOUNDS template. The designated type is adjusted to
3060 have ARRAY at position zero and the template at a negative offset, so
3061 that COMPONENT_REFs on (*thin_ptr) designate the proper location. */
3063 tree bounds_field = TYPE_FIELDS (type);
3064 tree array_field = TREE_CHAIN (TYPE_FIELDS (type));
3066 DECL_FIELD_OFFSET (bounds_field)
3067 = size_binop (MINUS_EXPR, size_zero_node, byte_position (array_field));
3069 DECL_FIELD_OFFSET (array_field) = size_zero_node;
3070 DECL_FIELD_BIT_OFFSET (array_field) = bitsize_zero_node;
3073 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE. In
3074 the normal case this is just two adjustments, but we have more to do
3075 if NEW is an UNCONSTRAINED_ARRAY_TYPE. */
3078 update_pointer_to (tree old_type, tree new_type)
3080 tree ptr = TYPE_POINTER_TO (old_type);
3081 tree ref = TYPE_REFERENCE_TO (old_type);
3085 /* If this is the main variant, process all the other variants first. */
3086 if (TYPE_MAIN_VARIANT (old_type) == old_type)
3087 for (type = TYPE_NEXT_VARIANT (old_type); type;
3088 type = TYPE_NEXT_VARIANT (type))
3089 update_pointer_to (type, new_type);
3091 /* If no pointer or reference, we are done. */
3095 /* Merge the old type qualifiers in the new type.
3097 Each old variant has qualifiers for specific reasons, and the new
3098 designated type as well. Each set of qualifiers represents useful
3099 information grabbed at some point, and merging the two simply unifies
3100 these inputs into the final type description.
3102 Consider for instance a volatile type frozen after an access to constant
3103 type designating it. After the designated type freeze, we get here with a
3104 volatile new_type and a dummy old_type with a readonly variant, created
3105 when the access type was processed. We shall make a volatile and readonly
3106 designated type, because that's what it really is.
3108 We might also get here for a non-dummy old_type variant with different
3109 qualifiers than the new_type ones, for instance in some cases of pointers
3110 to private record type elaboration (see the comments around the call to
3111 this routine from gnat_to_gnu_entity/E_Access_Type). We have to merge the
3112 qualifiers in thoses cases too, to avoid accidentally discarding the
3113 initial set, and will often end up with old_type == new_type then. */
3114 new_type = build_qualified_type (new_type,
3115 TYPE_QUALS (old_type)
3116 | TYPE_QUALS (new_type));
3118 /* If the new type and the old one are identical, there is nothing to
3120 if (old_type == new_type)
3123 /* Otherwise, first handle the simple case. */
3124 if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE)
3126 TYPE_POINTER_TO (new_type) = ptr;
3127 TYPE_REFERENCE_TO (new_type) = ref;
3129 for (; ptr; ptr = TYPE_NEXT_PTR_TO (ptr))
3130 for (ptr1 = TYPE_MAIN_VARIANT (ptr); ptr1;
3131 ptr1 = TYPE_NEXT_VARIANT (ptr1))
3132 TREE_TYPE (ptr1) = new_type;
3134 for (; ref; ref = TYPE_NEXT_REF_TO (ref))
3135 for (ref1 = TYPE_MAIN_VARIANT (ref); ref1;
3136 ref1 = TYPE_NEXT_VARIANT (ref1))
3137 TREE_TYPE (ref1) = new_type;
3140 /* Now deal with the unconstrained array case. In this case the "pointer"
3141 is actually a RECORD_TYPE where both fields are pointers to dummy nodes.
3142 Turn them into pointers to the correct types using update_pointer_to. */
3143 else if (TREE_CODE (ptr) != RECORD_TYPE || !TYPE_IS_FAT_POINTER_P (ptr))
3148 tree new_obj_rec = TYPE_OBJECT_RECORD_TYPE (new_type);
3149 tree array_field = TYPE_FIELDS (ptr);
3150 tree bounds_field = TREE_CHAIN (TYPE_FIELDS (ptr));
3151 tree new_ptr = TYPE_POINTER_TO (new_type);
3155 /* Make pointers to the dummy template point to the real template. */
3157 (TREE_TYPE (TREE_TYPE (bounds_field)),
3158 TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_ptr)))));
3160 /* The references to the template bounds present in the array type
3161 are made through a PLACEHOLDER_EXPR of type new_ptr. Since we
3162 are updating ptr to make it a full replacement for new_ptr as
3163 pointer to new_type, we must rework the PLACEHOLDER_EXPR so as
3164 to make it of type ptr. */
3165 new_ref = build3 (COMPONENT_REF, TREE_TYPE (bounds_field),
3166 build0 (PLACEHOLDER_EXPR, ptr),
3167 bounds_field, NULL_TREE);
3169 /* Create the new array for the new PLACEHOLDER_EXPR and make
3170 pointers to the dummy array point to it.
3172 ??? This is now the only use of substitute_in_type,
3173 which is a very "heavy" routine to do this, so it
3174 should be replaced at some point. */
3176 (TREE_TYPE (TREE_TYPE (array_field)),
3177 substitute_in_type (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (new_ptr))),
3178 TREE_CHAIN (TYPE_FIELDS (new_ptr)), new_ref));
3180 /* Make ptr the pointer to new_type. */
3181 TYPE_POINTER_TO (new_type) = TYPE_REFERENCE_TO (new_type)
3182 = TREE_TYPE (new_type) = ptr;
3184 for (var = TYPE_MAIN_VARIANT (ptr); var; var = TYPE_NEXT_VARIANT (var))
3185 SET_TYPE_UNCONSTRAINED_ARRAY (var, new_type);
3187 /* Now handle updating the allocation record, what the thin pointer
3188 points to. Update all pointers from the old record into the new
3189 one, update the type of the array field, and recompute the size. */
3190 update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), new_obj_rec);
3192 TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
3193 = TREE_TYPE (TREE_TYPE (array_field));
3195 /* The size recomputation needs to account for alignment constraints, so
3196 we let layout_type work it out. This will reset the field offsets to
3197 what they would be in a regular record, so we shift them back to what
3198 we want them to be for a thin pointer designated type afterwards. */
3199 DECL_SIZE (TYPE_FIELDS (new_obj_rec)) = 0;
3200 DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))) = 0;
3201 TYPE_SIZE (new_obj_rec) = 0;
3202 layout_type (new_obj_rec);
3204 shift_unc_components_for_thin_pointers (new_obj_rec);
3206 /* We are done, at last. */
3207 rest_of_record_type_compilation (ptr);
3211 /* Convert a pointer to a constrained array into a pointer to a fat
3212 pointer. This involves making or finding a template. */
3215 convert_to_fat_pointer (tree type, tree expr)
3217 tree template_type = TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type))));
3218 tree template, template_addr;
3219 tree etype = TREE_TYPE (expr);
3221 /* If EXPR is a constant of zero, we make a fat pointer that has a null
3222 pointer to the template and array. */
3223 if (integer_zerop (expr))
3225 gnat_build_constructor
3227 tree_cons (TYPE_FIELDS (type),
3228 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
3229 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
3230 convert (build_pointer_type (template_type),
3234 /* If EXPR is a thin pointer, make the template and data from the record. */
3236 else if (TYPE_THIN_POINTER_P (etype))
3238 tree fields = TYPE_FIELDS (TREE_TYPE (etype));
3240 expr = save_expr (expr);
3241 if (TREE_CODE (expr) == ADDR_EXPR)
3242 expr = TREE_OPERAND (expr, 0);
3244 expr = build1 (INDIRECT_REF, TREE_TYPE (etype), expr);
3246 template = build_component_ref (expr, NULL_TREE, fields, false);
3247 expr = build_unary_op (ADDR_EXPR, NULL_TREE,
3248 build_component_ref (expr, NULL_TREE,
3249 TREE_CHAIN (fields), false));
3252 /* Otherwise, build the constructor for the template. */
3253 template = build_template (template_type, TREE_TYPE (etype), expr);
3255 template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template);
3257 /* The result is a CONSTRUCTOR for the fat pointer.
3259 If expr is an argument of a foreign convention subprogram, the type it
3260 points to is directly the component type. In this case, the expression
3261 type may not match the corresponding FIELD_DECL type at this point, so we
3262 call "convert" here to fix that up if necessary. This type consistency is
3263 required, for instance because it ensures that possible later folding of
3264 component_refs against this constructor always yields something of the
3265 same type as the initial reference.
3267 Note that the call to "build_template" above is still fine, because it
3268 will only refer to the provided template_type in this case. */
3270 gnat_build_constructor
3271 (type, tree_cons (TYPE_FIELDS (type),
3272 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
3273 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
3274 template_addr, NULL_TREE)));
3277 /* Convert to a thin pointer type, TYPE. The only thing we know how to convert
3278 is something that is a fat pointer, so convert to it first if it EXPR
3279 is not already a fat pointer. */
3282 convert_to_thin_pointer (tree type, tree expr)
3284 if (!TYPE_FAT_POINTER_P (TREE_TYPE (expr)))
3286 = convert_to_fat_pointer
3287 (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))), expr);
3289 /* We get the pointer to the data and use a NOP_EXPR to make it the
3291 expr = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (TREE_TYPE (expr)),
3293 expr = build1 (NOP_EXPR, type, expr);
3298 /* Create an expression whose value is that of EXPR,
3299 converted to type TYPE. The TREE_TYPE of the value
3300 is always TYPE. This function implements all reasonable
3301 conversions; callers should filter out those that are
3302 not permitted by the language being compiled. */
3305 convert (tree type, tree expr)
3307 enum tree_code code = TREE_CODE (type);
3308 tree etype = TREE_TYPE (expr);
3309 enum tree_code ecode = TREE_CODE (etype);
3311 /* If EXPR is already the right type, we are done. */
3315 /* If both input and output have padding and are of variable size, do this
3316 as an unchecked conversion. Likewise if one is a mere variant of the
3317 other, so we avoid a pointless unpad/repad sequence. */
3318 else if (ecode == RECORD_TYPE && code == RECORD_TYPE
3319 && TYPE_IS_PADDING_P (type) && TYPE_IS_PADDING_P (etype)
3320 && (!TREE_CONSTANT (TYPE_SIZE (type))
3321 || !TREE_CONSTANT (TYPE_SIZE (etype))
3322 || TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype)))
3325 /* If the output type has padding, make a constructor to build the
3327 else if (code == RECORD_TYPE && TYPE_IS_PADDING_P (type))
3329 /* If we previously converted from another type and our type is
3330 of variable size, remove the conversion to avoid the need for
3331 variable-size temporaries. */
3332 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
3333 && !TREE_CONSTANT (TYPE_SIZE (type)))
3334 expr = TREE_OPERAND (expr, 0);
3336 /* If we are just removing the padding from expr, convert the original
3337 object if we have variable size. That will avoid the need
3338 for some variable-size temporaries. */
3339 if (TREE_CODE (expr) == COMPONENT_REF
3340 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE
3341 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (expr, 0)))
3342 && !TREE_CONSTANT (TYPE_SIZE (type)))
3343 return convert (type, TREE_OPERAND (expr, 0));
3345 /* If the result type is a padded type with a self-referentially-sized
3346 field and the expression type is a record, do this as an
3347 unchecked conversion. */
3348 else if (TREE_CODE (etype) == RECORD_TYPE
3349 && CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type))))
3350 return unchecked_convert (type, expr, false);
3354 gnat_build_constructor (type,
3355 tree_cons (TYPE_FIELDS (type),
3357 (TYPE_FIELDS (type)),
3362 /* If the input type has padding, remove it and convert to the output type.
3363 The conditions ordering is arranged to ensure that the output type is not
3364 a padding type here, as it is not clear whether the conversion would
3365 always be correct if this was to happen. */
3366 else if (ecode == RECORD_TYPE && TYPE_IS_PADDING_P (etype))
3370 /* If we have just converted to this padded type, just get the
3371 inner expression. */
3372 if (TREE_CODE (expr) == CONSTRUCTOR
3373 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (expr))
3374 && VEC_index (constructor_elt, CONSTRUCTOR_ELTS (expr), 0)->index
3375 == TYPE_FIELDS (etype))
3377 = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (expr), 0)->value;
3379 /* Otherwise, build an explicit component reference. */
3382 = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (etype), false);
3384 return convert (type, unpadded);
3387 /* If the input is a biased type, adjust first. */
3388 if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype))
3389 return convert (type, fold_build2 (PLUS_EXPR, TREE_TYPE (etype),
3390 fold_convert (TREE_TYPE (etype),
3392 TYPE_MIN_VALUE (etype)));
3394 /* If the input is a justified modular type, we need to extract the actual
3395 object before converting it to any other type with the exceptions of an
3396 unconstrained array or of a mere type variant. It is useful to avoid the
3397 extraction and conversion in the type variant case because it could end
3398 up replacing a VAR_DECL expr by a constructor and we might be about the
3399 take the address of the result. */
3400 if (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)
3401 && code != UNCONSTRAINED_ARRAY_TYPE
3402 && TYPE_MAIN_VARIANT (type) != TYPE_MAIN_VARIANT (etype))
3403 return convert (type, build_component_ref (expr, NULL_TREE,
3404 TYPE_FIELDS (etype), false));
3406 /* If converting to a type that contains a template, convert to the data
3407 type and then build the template. */
3408 if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type))
3410 tree obj_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type)));
3412 /* If the source already has a template, get a reference to the
3413 associated array only, as we are going to rebuild a template
3414 for the target type anyway. */
3415 expr = maybe_unconstrained_array (expr);
3418 gnat_build_constructor
3420 tree_cons (TYPE_FIELDS (type),
3421 build_template (TREE_TYPE (TYPE_FIELDS (type)),
3422 obj_type, NULL_TREE),
3423 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
3424 convert (obj_type, expr), NULL_TREE)));
3427 /* There are some special cases of expressions that we process
3429 switch (TREE_CODE (expr))
3435 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
3436 conversion in gnat_expand_expr. NULL_EXPR does not represent
3437 and actual value, so no conversion is needed. */
3438 expr = copy_node (expr);
3439 TREE_TYPE (expr) = type;
3443 /* If we are converting a STRING_CST to another constrained array type,
3444 just make a new one in the proper type. */
3445 if (code == ecode && AGGREGATE_TYPE_P (etype)
3446 && !(TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST
3447 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
3449 expr = copy_node (expr);
3450 TREE_TYPE (expr) = type;
3456 /* If we are converting a CONSTRUCTOR to another constrained array type
3457 with the same domain, just make a new one in the proper type. */
3458 if (code == ecode && code == ARRAY_TYPE
3459 && TREE_TYPE (type) == TREE_TYPE (etype)
3460 && tree_int_cst_equal (TYPE_MIN_VALUE (TYPE_DOMAIN (type)),
3461 TYPE_MIN_VALUE (TYPE_DOMAIN (etype)))
3462 && tree_int_cst_equal (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3463 TYPE_MAX_VALUE (TYPE_DOMAIN (etype))))
3465 expr = copy_node (expr);
3466 TREE_TYPE (expr) = type;
3471 case UNCONSTRAINED_ARRAY_REF:
3472 /* Convert this to the type of the inner array by getting the address of
3473 the array from the template. */
3474 expr = build_unary_op (INDIRECT_REF, NULL_TREE,
3475 build_component_ref (TREE_OPERAND (expr, 0),
3476 get_identifier ("P_ARRAY"),
3478 etype = TREE_TYPE (expr);
3479 ecode = TREE_CODE (etype);
3482 case VIEW_CONVERT_EXPR:
3484 /* GCC 4.x is very sensitive to type consistency overall, and view
3485 conversions thus are very frequent. Even though just "convert"ing
3486 the inner operand to the output type is fine in most cases, it
3487 might expose unexpected input/output type mismatches in special
3488 circumstances so we avoid such recursive calls when we can. */
3490 tree op0 = TREE_OPERAND (expr, 0);
3492 /* If we are converting back to the original type, we can just
3493 lift the input conversion. This is a common occurrence with
3494 switches back-and-forth amongst type variants. */
3495 if (type == TREE_TYPE (op0))
3498 /* Otherwise, if we're converting between two aggregate types, we
3499 might be allowed to substitute the VIEW_CONVERT target type in
3500 place or to just convert the inner expression. */
3501 if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype))
3503 /* If we are converting between type variants, we can just
3504 substitute the VIEW_CONVERT in place. */
3505 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype))
3506 return build1 (VIEW_CONVERT_EXPR, type, op0);
3508 /* Otherwise, we may just bypass the input view conversion unless
3509 one of the types is a fat pointer, which is handled by
3510 specialized code below which relies on exact type matching. */
3511 else if (!TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
3512 return convert (type, op0);
3518 /* If both types are record types, just convert the pointer and
3519 make a new INDIRECT_REF.
3521 ??? Disable this for now since it causes problems with the
3522 code in build_binary_op for MODIFY_EXPR which wants to
3523 strip off conversions. But that code really is a mess and
3524 we need to do this a much better way some time. */
3526 && (TREE_CODE (type) == RECORD_TYPE
3527 || TREE_CODE (type) == UNION_TYPE)
3528 && (TREE_CODE (etype) == RECORD_TYPE
3529 || TREE_CODE (etype) == UNION_TYPE)
3530 && !TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
3531 return build_unary_op (INDIRECT_REF, NULL_TREE,
3532 convert (build_pointer_type (type),
3533 TREE_OPERAND (expr, 0)));
3540 /* Check for converting to a pointer to an unconstrained array. */
3541 if (TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
3542 return convert_to_fat_pointer (type, expr);
3544 /* If we're converting between two aggregate types that have the same main
3545 variant, just make a VIEW_CONVER_EXPR. */
3546 else if (AGGREGATE_TYPE_P (type)
3547 && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype))
3548 return build1 (VIEW_CONVERT_EXPR, type, expr);
3550 /* In all other cases of related types, make a NOP_EXPR. */
3551 else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype)
3552 || (code == INTEGER_CST && ecode == INTEGER_CST
3553 && (type == TREE_TYPE (etype) || etype == TREE_TYPE (type))))
3554 return fold_convert (type, expr);
3559 return fold_build1 (CONVERT_EXPR, type, expr);
3562 return fold_convert (type, gnat_truthvalue_conversion (expr));
3565 if (TYPE_HAS_ACTUAL_BOUNDS_P (type)
3566 && (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE
3567 || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))))
3568 return unchecked_convert (type, expr, false);
3569 else if (TYPE_BIASED_REPRESENTATION_P (type))
3570 return fold_convert (type,
3571 fold_build2 (MINUS_EXPR, TREE_TYPE (type),
3572 convert (TREE_TYPE (type), expr),
3573 TYPE_MIN_VALUE (type)));
3575 /* ... fall through ... */
3578 return fold (convert_to_integer (type, expr));
3581 case REFERENCE_TYPE:
3582 /* If converting between two pointers to records denoting
3583 both a template and type, adjust if needed to account
3584 for any differing offsets, since one might be negative. */
3585 if (TYPE_THIN_POINTER_P (etype) && TYPE_THIN_POINTER_P (type))
3588 = size_diffop (bit_position (TYPE_FIELDS (TREE_TYPE (etype))),
3589 bit_position (TYPE_FIELDS (TREE_TYPE (type))));
3590 tree byte_diff = size_binop (CEIL_DIV_EXPR, bit_diff,
3591 sbitsize_int (BITS_PER_UNIT));
3593 expr = build1 (NOP_EXPR, type, expr);
3594 TREE_CONSTANT (expr) = TREE_CONSTANT (TREE_OPERAND (expr, 0));
3595 if (integer_zerop (byte_diff))
3598 return build_binary_op (POINTER_PLUS_EXPR, type, expr,
3599 fold (convert (sizetype, byte_diff)));
3602 /* If converting to a thin pointer, handle specially. */
3603 if (TYPE_THIN_POINTER_P (type)
3604 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
3605 return convert_to_thin_pointer (type, expr);
3607 /* If converting fat pointer to normal pointer, get the pointer to the
3608 array and then convert it. */
3609 else if (TYPE_FAT_POINTER_P (etype))
3610 expr = build_component_ref (expr, get_identifier ("P_ARRAY"),
3613 return fold (convert_to_pointer (type, expr));
3616 return fold (convert_to_real (type, expr));
3619 if (TYPE_JUSTIFIED_MODULAR_P (type) && !AGGREGATE_TYPE_P (etype))
3621 gnat_build_constructor
3622 (type, tree_cons (TYPE_FIELDS (type),
3623 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
3626 /* ... fall through ... */
3629 /* In these cases, assume the front-end has validated the conversion.
3630 If the conversion is valid, it will be a bit-wise conversion, so
3631 it can be viewed as an unchecked conversion. */
3632 return unchecked_convert (type, expr, false);
3635 /* This is a either a conversion between a tagged type and some
3636 subtype, which we have to mark as a UNION_TYPE because of
3637 overlapping fields or a conversion of an Unchecked_Union. */
3638 return unchecked_convert (type, expr, false);
3640 case UNCONSTRAINED_ARRAY_TYPE:
3641 /* If EXPR is a constrained array, take its address, convert it to a
3642 fat pointer, and then dereference it. Likewise if EXPR is a
3643 record containing both a template and a constrained array.
3644 Note that a record representing a justified modular type
3645 always represents a packed constrained array. */
3646 if (ecode == ARRAY_TYPE
3647 || (ecode == INTEGER_TYPE && TYPE_HAS_ACTUAL_BOUNDS_P (etype))
3648 || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))
3649 || (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)))
3652 (INDIRECT_REF, NULL_TREE,
3653 convert_to_fat_pointer (TREE_TYPE (type),
3654 build_unary_op (ADDR_EXPR,
3657 /* Do something very similar for converting one unconstrained
3658 array to another. */
3659 else if (ecode == UNCONSTRAINED_ARRAY_TYPE)
3661 build_unary_op (INDIRECT_REF, NULL_TREE,
3662 convert (TREE_TYPE (type),
3663 build_unary_op (ADDR_EXPR,
3669 return fold (convert_to_complex (type, expr));
3676 /* Remove all conversions that are done in EXP. This includes converting
3677 from a padded type or to a justified modular type. If TRUE_ADDRESS
3678 is true, always return the address of the containing object even if
3679 the address is not bit-aligned. */
3682 remove_conversions (tree exp, bool true_address)
3684 switch (TREE_CODE (exp))
3688 && TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
3689 && TYPE_JUSTIFIED_MODULAR_P (TREE_TYPE (exp)))
3691 remove_conversions (VEC_index (constructor_elt,
3692 CONSTRUCTOR_ELTS (exp), 0)->value,
3697 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == RECORD_TYPE
3698 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
3699 return remove_conversions (TREE_OPERAND (exp, 0), true_address);
3702 case VIEW_CONVERT_EXPR: case NON_LVALUE_EXPR:
3703 case NOP_EXPR: case CONVERT_EXPR:
3704 return remove_conversions (TREE_OPERAND (exp, 0), true_address);
3713 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
3714 refers to the underlying array. If its type has TYPE_CONTAINS_TEMPLATE_P,
3715 likewise return an expression pointing to the underlying array. */
3718 maybe_unconstrained_array (tree exp)
3720 enum tree_code code = TREE_CODE (exp);
3723 switch (TREE_CODE (TREE_TYPE (exp)))
3725 case UNCONSTRAINED_ARRAY_TYPE:
3726 if (code == UNCONSTRAINED_ARRAY_REF)
3729 = build_unary_op (INDIRECT_REF, NULL_TREE,
3730 build_component_ref (TREE_OPERAND (exp, 0),
3731 get_identifier ("P_ARRAY"),
3733 TREE_READONLY (new) = TREE_STATIC (new) = TREE_READONLY (exp);
3737 else if (code == NULL_EXPR)
3738 return build1 (NULL_EXPR,
3739 TREE_TYPE (TREE_TYPE (TYPE_FIELDS
3740 (TREE_TYPE (TREE_TYPE (exp))))),
3741 TREE_OPERAND (exp, 0));
3744 /* If this is a padded type, convert to the unpadded type and see if
3745 it contains a template. */
3746 if (TYPE_IS_PADDING_P (TREE_TYPE (exp)))
3748 new = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (exp))), exp);
3749 if (TREE_CODE (TREE_TYPE (new)) == RECORD_TYPE
3750 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (new)))
3752 build_component_ref (new, NULL_TREE,
3753 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new))),
3756 else if (TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (exp)))
3758 build_component_ref (exp, NULL_TREE,
3759 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (exp))), 0);
3769 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
3770 If NOTRUNC_P is true, truncation operations should be suppressed. */
3773 unchecked_convert (tree type, tree expr, bool notrunc_p)
3775 tree etype = TREE_TYPE (expr);
3777 /* If the expression is already the right type, we are done. */
3781 /* If both types types are integral just do a normal conversion.
3782 Likewise for a conversion to an unconstrained array. */
3783 if ((((INTEGRAL_TYPE_P (type)
3784 && !(TREE_CODE (type) == INTEGER_TYPE
3785 && TYPE_VAX_FLOATING_POINT_P (type)))
3786 || (POINTER_TYPE_P (type) && ! TYPE_THIN_POINTER_P (type))
3787 || (TREE_CODE (type) == RECORD_TYPE
3788 && TYPE_JUSTIFIED_MODULAR_P (type)))
3789 && ((INTEGRAL_TYPE_P (etype)
3790 && !(TREE_CODE (etype) == INTEGER_TYPE
3791 && TYPE_VAX_FLOATING_POINT_P (etype)))
3792 || (POINTER_TYPE_P (etype) && !TYPE_THIN_POINTER_P (etype))
3793 || (TREE_CODE (etype) == RECORD_TYPE
3794 && TYPE_JUSTIFIED_MODULAR_P (etype))))
3795 || TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
3798 bool final_unchecked = false;
3800 if (TREE_CODE (etype) == INTEGER_TYPE
3801 && TYPE_BIASED_REPRESENTATION_P (etype))
3803 tree ntype = copy_type (etype);
3805 TYPE_BIASED_REPRESENTATION_P (ntype) = 0;
3806 TYPE_MAIN_VARIANT (ntype) = ntype;
3807 expr = build1 (NOP_EXPR, ntype, expr);
3810 if (TREE_CODE (type) == INTEGER_TYPE
3811 && TYPE_BIASED_REPRESENTATION_P (type))
3813 rtype = copy_type (type);
3814 TYPE_BIASED_REPRESENTATION_P (rtype) = 0;
3815 TYPE_MAIN_VARIANT (rtype) = rtype;
3818 /* We have another special case: if we are unchecked converting subtype
3819 into a base type, we need to ensure that VRP doesn't propagate range
3820 information since this conversion may be done precisely to validate
3821 that the object is within the range it is supposed to have. */
3822 else if (TREE_CODE (expr) != INTEGER_CST
3823 && TREE_CODE (type) == INTEGER_TYPE && !TREE_TYPE (type)
3824 && ((TREE_CODE (etype) == INTEGER_TYPE && TREE_TYPE (etype))
3825 || TREE_CODE (etype) == ENUMERAL_TYPE
3826 || TREE_CODE (etype) == BOOLEAN_TYPE))
3828 /* The optimization barrier is a VIEW_CONVERT_EXPR node; moreover,
3829 in order not to be deemed an useless type conversion, it must
3830 be from subtype to base type.
3832 ??? This may raise addressability and/or aliasing issues because
3833 VIEW_CONVERT_EXPR gets gimplified as an lvalue, thus causing the
3834 address of its operand to be taken if it is deemed addressable
3835 and not already in GIMPLE form. */
3836 rtype = gnat_type_for_mode (TYPE_MODE (type), TYPE_UNSIGNED (type));
3837 rtype = copy_type (rtype);
3838 TYPE_MAIN_VARIANT (rtype) = rtype;
3839 TREE_TYPE (rtype) = type;
3840 final_unchecked = true;
3843 expr = convert (rtype, expr);
3845 expr = build1 (final_unchecked ? VIEW_CONVERT_EXPR : NOP_EXPR,
3849 /* If we are converting TO an integral type whose precision is not the
3850 same as its size, first unchecked convert to a record that contains
3851 an object of the output type. Then extract the field. */
3852 else if (INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type)
3853 && 0 != compare_tree_int (TYPE_RM_SIZE (type),
3854 GET_MODE_BITSIZE (TYPE_MODE (type))))
3856 tree rec_type = make_node (RECORD_TYPE);
3857 tree field = create_field_decl (get_identifier ("OBJ"), type,
3858 rec_type, 1, 0, 0, 0);
3860 TYPE_FIELDS (rec_type) = field;
3861 layout_type (rec_type);
3863 expr = unchecked_convert (rec_type, expr, notrunc_p);
3864 expr = build_component_ref (expr, NULL_TREE, field, 0);
3867 /* Similarly for integral input type whose precision is not equal to its
3869 else if (INTEGRAL_TYPE_P (etype) && TYPE_RM_SIZE (etype)
3870 && 0 != compare_tree_int (TYPE_RM_SIZE (etype),
3871 GET_MODE_BITSIZE (TYPE_MODE (etype))))
3873 tree rec_type = make_node (RECORD_TYPE);
3875 = create_field_decl (get_identifier ("OBJ"), etype, rec_type,
3878 TYPE_FIELDS (rec_type) = field;
3879 layout_type (rec_type);
3881 expr = gnat_build_constructor (rec_type, build_tree_list (field, expr));
3882 expr = unchecked_convert (type, expr, notrunc_p);
3885 /* We have a special case when we are converting between two
3886 unconstrained array types. In that case, take the address,
3887 convert the fat pointer types, and dereference. */
3888 else if (TREE_CODE (etype) == UNCONSTRAINED_ARRAY_TYPE
3889 && TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
3890 expr = build_unary_op (INDIRECT_REF, NULL_TREE,
3891 build1 (VIEW_CONVERT_EXPR, TREE_TYPE (type),
3892 build_unary_op (ADDR_EXPR, NULL_TREE,
3896 expr = maybe_unconstrained_array (expr);
3898 /* There's no point in doing two unchecked conversions in a row. */
3899 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
3900 expr = TREE_OPERAND (expr, 0);
3902 etype = TREE_TYPE (expr);
3903 expr = build1 (VIEW_CONVERT_EXPR, type, expr);
3906 /* If the result is an integral type whose size is not equal to
3907 the size of the underlying machine type, sign- or zero-extend
3908 the result. We need not do this in the case where the input is
3909 an integral type of the same precision and signedness or if the output
3910 is a biased type or if both the input and output are unsigned. */
3912 && INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type)
3913 && !(TREE_CODE (type) == INTEGER_TYPE
3914 && TYPE_BIASED_REPRESENTATION_P (type))
3915 && 0 != compare_tree_int (TYPE_RM_SIZE (type),
3916 GET_MODE_BITSIZE (TYPE_MODE (type)))
3917 && !(INTEGRAL_TYPE_P (etype)
3918 && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (etype)
3919 && operand_equal_p (TYPE_RM_SIZE (type),
3920 (TYPE_RM_SIZE (etype) != 0
3921 ? TYPE_RM_SIZE (etype) : TYPE_SIZE (etype)),
3923 && !(TYPE_UNSIGNED (type) && TYPE_UNSIGNED (etype)))
3925 tree base_type = gnat_type_for_mode (TYPE_MODE (type),
3926 TYPE_UNSIGNED (type));
3928 = convert (base_type,
3929 size_binop (MINUS_EXPR,
3931 (GET_MODE_BITSIZE (TYPE_MODE (type))),
3932 TYPE_RM_SIZE (type)));
3935 build_binary_op (RSHIFT_EXPR, base_type,
3936 build_binary_op (LSHIFT_EXPR, base_type,
3937 convert (base_type, expr),
3942 /* An unchecked conversion should never raise Constraint_Error. The code
3943 below assumes that GCC's conversion routines overflow the same way that
3944 the underlying hardware does. This is probably true. In the rare case
3945 when it is false, we can rely on the fact that such conversions are
3946 erroneous anyway. */
3947 if (TREE_CODE (expr) == INTEGER_CST)
3948 TREE_OVERFLOW (expr) = 0;
3950 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
3951 show no longer constant. */
3952 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
3953 && !operand_equal_p (TYPE_SIZE_UNIT (type), TYPE_SIZE_UNIT (etype),
3955 TREE_CONSTANT (expr) = 0;
3960 /* Search the chain of currently available builtin declarations for a node
3961 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
3962 found, if any, or NULL_TREE otherwise. */
3964 builtin_decl_for (tree name)
3969 for (i = 0; VEC_iterate(tree, builtin_decls, i, decl); i++)
3970 if (DECL_NAME (decl) == name)
3976 /* Return the appropriate GCC tree code for the specified GNAT type,
3977 the latter being a record type as predicated by Is_Record_Type. */
3980 tree_code_for_record_type (Entity_Id gnat_type)
3982 Node_Id component_list
3983 = Component_List (Type_Definition
3985 (Implementation_Base_Type (gnat_type))));
3988 /* Make this a UNION_TYPE unless it's either not an Unchecked_Union or
3989 we have a non-discriminant field outside a variant. In either case,
3990 it's a RECORD_TYPE. */
3992 if (!Is_Unchecked_Union (gnat_type))
3995 for (component = First_Non_Pragma (Component_Items (component_list));
3996 Present (component);
3997 component = Next_Non_Pragma (component))
3998 if (Ekind (Defining_Entity (component)) == E_Component)
4004 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
4005 component of an aggregate type. */
4008 type_for_nonaliased_component_p (tree gnu_type)
4010 /* If the type is passed by reference, we may have pointers to the
4011 component so it cannot be made non-aliased. */
4012 if (must_pass_by_ref (gnu_type) || default_pass_by_ref (gnu_type))
4015 /* We used to say that any component of aggregate type is aliased
4016 because the front-end may take 'Reference of it. The front-end
4017 has been enhanced in the meantime so as to use a renaming instead
4018 in most cases, but the back-end can probably take the address of
4019 such a component too so we go for the conservative stance.
4021 For instance, we might need the address of any array type, even
4022 if normally passed by copy, to construct a fat pointer if the
4023 component is used as an actual for an unconstrained formal.
4025 Likewise for record types: even if a specific record subtype is
4026 passed by copy, the parent type might be passed by ref (e.g. if
4027 it's of variable size) and we might take the address of a child
4028 component to pass to a parent formal. We have no way to check
4029 for such conditions here. */
4030 if (AGGREGATE_TYPE_P (gnu_type))
4036 /* Perform final processing on global variables. */
4039 gnat_write_global_declarations (void)
4041 /* Proceed to optimize and emit assembly.
4042 FIXME: shouldn't be the front end's responsibility to call this. */
4045 /* Emit debug info for all global declarations. */
4046 emit_debug_global_declarations (VEC_address (tree, global_decls),
4047 VEC_length (tree, global_decls));
4050 #include "gt-ada-utils.h"
4051 #include "gtype-ada.h"
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