1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2009, 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 ****************************************************************************/
26 /* We have attribute handlers using C specific format specifiers in warning
27 messages. Make sure they are properly recognized. */
28 #define GCC_DIAG_STYLE __gcc_cdiag__
32 #include "coretypes.h"
45 #include "tree-inline.h"
46 #include "tree-iterator.h"
48 #include "tree-dump.h"
49 #include "pointer-set.h"
50 #include "langhooks.h"
66 #ifndef MAX_FIXED_MODE_SIZE
67 #define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
70 #ifndef MAX_BITS_PER_WORD
71 #define MAX_BITS_PER_WORD BITS_PER_WORD
74 /* If nonzero, pretend we are allocating at global level. */
77 /* Tree nodes for the various types and decls we create. */
78 tree gnat_std_decls[(int) ADT_LAST];
80 /* Functions to call for each of the possible raise reasons. */
81 tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
83 /* Forward declarations for handlers of attributes. */
84 static tree handle_const_attribute (tree *, tree, tree, int, bool *);
85 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
86 static tree handle_pure_attribute (tree *, tree, tree, int, bool *);
87 static tree handle_novops_attribute (tree *, tree, tree, int, bool *);
88 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
89 static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *);
90 static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
91 static tree handle_malloc_attribute (tree *, tree, tree, int, bool *);
92 static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *);
94 /* Fake handler for attributes we don't properly support, typically because
95 they'd require dragging a lot of the common-c front-end circuitry. */
96 static tree fake_attribute_handler (tree *, tree, tree, int, bool *);
98 /* Table of machine-independent internal attributes for Ada. We support
99 this minimal set of attributes to accommodate the needs of builtins. */
100 const struct attribute_spec gnat_internal_attribute_table[] =
102 /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
103 { "const", 0, 0, true, false, false, handle_const_attribute },
104 { "nothrow", 0, 0, true, false, false, handle_nothrow_attribute },
105 { "pure", 0, 0, true, false, false, handle_pure_attribute },
106 { "no vops", 0, 0, true, false, false, handle_novops_attribute },
107 { "nonnull", 0, -1, false, true, true, handle_nonnull_attribute },
108 { "sentinel", 0, 1, false, true, true, handle_sentinel_attribute },
109 { "noreturn", 0, 0, true, false, false, handle_noreturn_attribute },
110 { "malloc", 0, 0, true, false, false, handle_malloc_attribute },
111 { "type generic", 0, 0, false, true, true, handle_type_generic_attribute },
113 /* ??? format and format_arg are heavy and not supported, which actually
114 prevents support for stdio builtins, which we however declare as part
115 of the common builtins.def contents. */
116 { "format", 3, 3, false, true, true, fake_attribute_handler },
117 { "format_arg", 1, 1, false, true, true, fake_attribute_handler },
119 { NULL, 0, 0, false, false, false, NULL }
122 /* Associates a GNAT tree node to a GCC tree node. It is used in
123 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
124 of `save_gnu_tree' for more info. */
125 static GTY((length ("max_gnat_nodes"))) tree *associate_gnat_to_gnu;
127 #define GET_GNU_TREE(GNAT_ENTITY) \
128 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id]
130 #define SET_GNU_TREE(GNAT_ENTITY,VAL) \
131 associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL)
133 #define PRESENT_GNU_TREE(GNAT_ENTITY) \
134 (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
136 /* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */
137 static GTY((length ("max_gnat_nodes"))) tree *dummy_node_table;
139 #define GET_DUMMY_NODE(GNAT_ENTITY) \
140 dummy_node_table[(GNAT_ENTITY) - First_Node_Id]
142 #define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \
143 dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL)
145 #define PRESENT_DUMMY_NODE(GNAT_ENTITY) \
146 (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE)
148 /* This variable keeps a table for types for each precision so that we only
149 allocate each of them once. Signed and unsigned types are kept separate.
151 Note that these types are only used when fold-const requests something
152 special. Perhaps we should NOT share these types; we'll see how it
154 static GTY(()) tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2];
156 /* Likewise for float types, but record these by mode. */
157 static GTY(()) tree float_types[NUM_MACHINE_MODES];
159 /* For each binding contour we allocate a binding_level structure to indicate
160 the binding depth. */
162 struct gnat_binding_level GTY((chain_next ("%h.chain")))
164 /* The binding level containing this one (the enclosing binding level). */
165 struct gnat_binding_level *chain;
166 /* The BLOCK node for this level. */
168 /* If nonzero, the setjmp buffer that needs to be updated for any
169 variable-sized definition within this context. */
173 /* The binding level currently in effect. */
174 static GTY(()) struct gnat_binding_level *current_binding_level;
176 /* A chain of gnat_binding_level structures awaiting reuse. */
177 static GTY((deletable)) struct gnat_binding_level *free_binding_level;
179 /* An array of global declarations. */
180 static GTY(()) VEC(tree,gc) *global_decls;
182 /* An array of builtin function declarations. */
183 static GTY(()) VEC(tree,gc) *builtin_decls;
185 /* An array of global renaming pointers. */
186 static GTY(()) VEC(tree,gc) *global_renaming_pointers;
188 /* A chain of unused BLOCK nodes. */
189 static GTY((deletable)) tree free_block_chain;
191 static tree merge_sizes (tree, tree, tree, bool, bool);
192 static tree compute_related_constant (tree, tree);
193 static tree split_plus (tree, tree *);
194 static void gnat_gimplify_function (tree);
195 static tree float_type_for_precision (int, enum machine_mode);
196 static tree convert_to_fat_pointer (tree, tree);
197 static tree convert_to_thin_pointer (tree, tree);
198 static tree make_descriptor_field (const char *,tree, tree, tree);
199 static bool potential_alignment_gap (tree, tree, tree);
201 /* Initialize the association of GNAT nodes to GCC trees. */
204 init_gnat_to_gnu (void)
206 associate_gnat_to_gnu
207 = (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
210 /* GNAT_ENTITY is a GNAT tree node for an entity. GNU_DECL is the GCC tree
211 which is to be associated with GNAT_ENTITY. Such GCC tree node is always
212 a ..._DECL node. If NO_CHECK is true, the latter check is suppressed.
214 If GNU_DECL is zero, a previous association is to be reset. */
217 save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl, bool no_check)
219 /* Check that GNAT_ENTITY is not already defined and that it is being set
220 to something which is a decl. Raise gigi 401 if not. Usually, this
221 means GNAT_ENTITY is defined twice, but occasionally is due to some
223 gcc_assert (!(gnu_decl
224 && (PRESENT_GNU_TREE (gnat_entity)
225 || (!no_check && !DECL_P (gnu_decl)))));
227 SET_GNU_TREE (gnat_entity, gnu_decl);
230 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
231 Return the ..._DECL node that was associated with it. If there is no tree
232 node associated with GNAT_ENTITY, abort.
234 In some cases, such as delayed elaboration or expressions that need to
235 be elaborated only once, GNAT_ENTITY is really not an entity. */
238 get_gnu_tree (Entity_Id gnat_entity)
240 gcc_assert (PRESENT_GNU_TREE (gnat_entity));
241 return GET_GNU_TREE (gnat_entity);
244 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
247 present_gnu_tree (Entity_Id gnat_entity)
249 return PRESENT_GNU_TREE (gnat_entity);
252 /* Initialize the association of GNAT nodes to GCC trees as dummies. */
255 init_dummy_type (void)
258 = (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
261 /* Make a dummy type corresponding to GNAT_TYPE. */
264 make_dummy_type (Entity_Id gnat_type)
266 Entity_Id gnat_underlying = Gigi_Equivalent_Type (gnat_type);
269 /* If there is an equivalent type, get its underlying type. */
270 if (Present (gnat_underlying))
271 gnat_underlying = Underlying_Type (gnat_underlying);
273 /* If there was no equivalent type (can only happen when just annotating
274 types) or underlying type, go back to the original type. */
275 if (No (gnat_underlying))
276 gnat_underlying = gnat_type;
278 /* If it there already a dummy type, use that one. Else make one. */
279 if (PRESENT_DUMMY_NODE (gnat_underlying))
280 return GET_DUMMY_NODE (gnat_underlying);
282 /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make
284 gnu_type = make_node (Is_Record_Type (gnat_underlying)
285 ? tree_code_for_record_type (gnat_underlying)
287 TYPE_NAME (gnu_type) = get_entity_name (gnat_type);
288 TYPE_DUMMY_P (gnu_type) = 1;
289 TYPE_STUB_DECL (gnu_type)
290 = create_type_stub_decl (TYPE_NAME (gnu_type), gnu_type);
291 if (AGGREGATE_TYPE_P (gnu_type))
292 TYPE_BY_REFERENCE_P (gnu_type) = Is_By_Reference_Type (gnat_type);
294 SET_DUMMY_NODE (gnat_underlying, gnu_type);
299 /* Return nonzero if we are currently in the global binding level. */
302 global_bindings_p (void)
304 return ((force_global || !current_function_decl) ? -1 : 0);
307 /* Enter a new binding level. */
312 struct gnat_binding_level *newlevel = NULL;
314 /* Reuse a struct for this binding level, if there is one. */
315 if (free_binding_level)
317 newlevel = free_binding_level;
318 free_binding_level = free_binding_level->chain;
322 = (struct gnat_binding_level *)
323 ggc_alloc (sizeof (struct gnat_binding_level));
325 /* Use a free BLOCK, if any; otherwise, allocate one. */
326 if (free_block_chain)
328 newlevel->block = free_block_chain;
329 free_block_chain = BLOCK_CHAIN (free_block_chain);
330 BLOCK_CHAIN (newlevel->block) = NULL_TREE;
333 newlevel->block = make_node (BLOCK);
335 /* Point the BLOCK we just made to its parent. */
336 if (current_binding_level)
337 BLOCK_SUPERCONTEXT (newlevel->block) = current_binding_level->block;
339 BLOCK_VARS (newlevel->block) = BLOCK_SUBBLOCKS (newlevel->block) = NULL_TREE;
340 TREE_USED (newlevel->block) = 1;
342 /* Add this level to the front of the chain (stack) of levels that are
344 newlevel->chain = current_binding_level;
345 newlevel->jmpbuf_decl = NULL_TREE;
346 current_binding_level = newlevel;
349 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
350 and point FNDECL to this BLOCK. */
353 set_current_block_context (tree fndecl)
355 BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl;
356 DECL_INITIAL (fndecl) = current_binding_level->block;
359 /* Set the jmpbuf_decl for the current binding level to DECL. */
362 set_block_jmpbuf_decl (tree decl)
364 current_binding_level->jmpbuf_decl = decl;
367 /* Get the jmpbuf_decl, if any, for the current binding level. */
370 get_block_jmpbuf_decl ()
372 return current_binding_level->jmpbuf_decl;
375 /* Exit a binding level. Set any BLOCK into the current code group. */
380 struct gnat_binding_level *level = current_binding_level;
381 tree block = level->block;
383 BLOCK_VARS (block) = nreverse (BLOCK_VARS (block));
384 BLOCK_SUBBLOCKS (block) = nreverse (BLOCK_SUBBLOCKS (block));
386 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
387 are no variables free the block and merge its subblocks into those of its
388 parent block. Otherwise, add it to the list of its parent. */
389 if (TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)
391 else if (BLOCK_VARS (block) == NULL_TREE)
393 BLOCK_SUBBLOCKS (level->chain->block)
394 = chainon (BLOCK_SUBBLOCKS (block),
395 BLOCK_SUBBLOCKS (level->chain->block));
396 BLOCK_CHAIN (block) = free_block_chain;
397 free_block_chain = block;
401 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (level->chain->block);
402 BLOCK_SUBBLOCKS (level->chain->block) = block;
403 TREE_USED (block) = 1;
404 set_block_for_group (block);
407 /* Free this binding structure. */
408 current_binding_level = level->chain;
409 level->chain = free_binding_level;
410 free_binding_level = level;
414 /* Records a ..._DECL node DECL as belonging to the current lexical scope
415 and uses GNAT_NODE for location information and propagating flags. */
418 gnat_pushdecl (tree decl, Node_Id gnat_node)
420 /* If this decl is public external or at toplevel, there is no context.
421 But PARM_DECLs always go in the level of its function. */
422 if (TREE_CODE (decl) != PARM_DECL
423 && ((DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
424 || global_bindings_p ()))
425 DECL_CONTEXT (decl) = 0;
428 DECL_CONTEXT (decl) = current_function_decl;
430 /* Functions imported in another function are not really nested. */
431 if (TREE_CODE (decl) == FUNCTION_DECL && TREE_PUBLIC (decl))
432 DECL_NO_STATIC_CHAIN (decl) = 1;
435 TREE_NO_WARNING (decl) = (gnat_node == Empty || Warnings_Off (gnat_node));
437 /* Set the location of DECL and emit a declaration for it. */
438 if (Present (gnat_node))
439 Sloc_to_locus (Sloc (gnat_node), &DECL_SOURCE_LOCATION (decl));
440 add_decl_expr (decl, gnat_node);
442 /* Put the declaration on the list. The list of declarations is in reverse
443 order. The list will be reversed later. Put global variables in the
444 globals list and builtin functions in a dedicated list to speed up
445 further lookups. Don't put TYPE_DECLs for UNCONSTRAINED_ARRAY_TYPE into
446 the list, as they will cause trouble with the debugger and aren't needed
448 if (TREE_CODE (decl) != TYPE_DECL
449 || TREE_CODE (TREE_TYPE (decl)) != UNCONSTRAINED_ARRAY_TYPE)
451 if (global_bindings_p ())
453 VEC_safe_push (tree, gc, global_decls, decl);
455 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
456 VEC_safe_push (tree, gc, builtin_decls, decl);
460 TREE_CHAIN (decl) = BLOCK_VARS (current_binding_level->block);
461 BLOCK_VARS (current_binding_level->block) = decl;
465 /* For the declaration of a type, set its name if it either is not already
466 set or if the previous type name was not derived from a source name.
467 We'd rather have the type named with a real name and all the pointer
468 types to the same object have the same POINTER_TYPE node. Code in the
469 equivalent function of c-decl.c makes a copy of the type node here, but
470 that may cause us trouble with incomplete types. We make an exception
471 for fat pointer types because the compiler automatically builds them
472 for unconstrained array types and the debugger uses them to represent
473 both these and pointers to these. */
474 if (TREE_CODE (decl) == TYPE_DECL && DECL_NAME (decl))
476 tree t = TREE_TYPE (decl);
478 if (!(TYPE_NAME (t) && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL))
480 else if (TYPE_FAT_POINTER_P (t))
482 tree tt = build_variant_type_copy (t);
483 TYPE_NAME (tt) = decl;
484 TREE_USED (tt) = TREE_USED (t);
485 TREE_TYPE (decl) = tt;
486 DECL_ORIGINAL_TYPE (decl) = t;
489 else if (DECL_ARTIFICIAL (TYPE_NAME (t)) && !DECL_ARTIFICIAL (decl))
494 /* Propagate the name to all the variants. This is needed for
495 the type qualifiers machinery to work properly. */
497 for (t = TYPE_MAIN_VARIANT (t); t; t = TYPE_NEXT_VARIANT (t))
498 TYPE_NAME (t) = decl;
502 /* Do little here. Set up the standard declarations later after the
503 front end has been run. */
506 gnat_init_decl_processing (void)
508 /* Make the binding_level structure for global names. */
509 current_function_decl = 0;
510 current_binding_level = 0;
511 free_binding_level = 0;
514 build_common_tree_nodes (true, true);
516 /* In Ada, we use a signed type for SIZETYPE. Use the signed type
517 corresponding to the size of Pmode. In most cases when ptr_mode and
518 Pmode differ, C will use the width of ptr_mode as sizetype. But we get
519 far better code using the width of Pmode. Make this here since we need
520 this before we can expand the GNAT types. */
521 size_type_node = gnat_type_for_size (GET_MODE_BITSIZE (Pmode), 0);
522 set_sizetype (size_type_node);
524 /* In Ada, we use an unsigned 8-bit type for the default boolean type. */
525 boolean_type_node = make_node (BOOLEAN_TYPE);
526 TYPE_PRECISION (boolean_type_node) = 1;
527 fixup_unsigned_type (boolean_type_node);
528 TYPE_RM_SIZE_NUM (boolean_type_node) = bitsize_int (1);
530 build_common_tree_nodes_2 (0);
532 ptr_void_type_node = build_pointer_type (void_type_node);
535 /* Record TYPE as a builtin type for Ada. NAME is the name of the type. */
538 record_builtin_type (const char *name, tree type)
540 tree type_decl = build_decl (TYPE_DECL, get_identifier (name), type);
542 gnat_pushdecl (type_decl, Empty);
544 if (debug_hooks->type_decl)
545 debug_hooks->type_decl (type_decl, false);
548 /* Given a record type RECORD_TYPE and a chain of FIELD_DECL nodes FIELDLIST,
549 finish constructing the record or union type. If REP_LEVEL is zero, this
550 record has no representation clause and so will be entirely laid out here.
551 If REP_LEVEL is one, this record has a representation clause and has been
552 laid out already; only set the sizes and alignment. If REP_LEVEL is two,
553 this record is derived from a parent record and thus inherits its layout;
554 only make a pass on the fields to finalize them. If DO_NOT_FINALIZE is
555 true, the record type is expected to be modified afterwards so it will
556 not be sent to the back-end for finalization. */
559 finish_record_type (tree record_type, tree fieldlist, int rep_level,
560 bool do_not_finalize)
562 enum tree_code code = TREE_CODE (record_type);
563 tree name = TYPE_NAME (record_type);
564 tree ada_size = bitsize_zero_node;
565 tree size = bitsize_zero_node;
566 bool had_size = TYPE_SIZE (record_type) != 0;
567 bool had_size_unit = TYPE_SIZE_UNIT (record_type) != 0;
568 bool had_align = TYPE_ALIGN (record_type) != 0;
571 TYPE_FIELDS (record_type) = fieldlist;
573 /* Always attach the TYPE_STUB_DECL for a record type. It is required to
574 generate debug info and have a parallel type. */
575 if (name && TREE_CODE (name) == TYPE_DECL)
576 name = DECL_NAME (name);
577 TYPE_STUB_DECL (record_type) = create_type_stub_decl (name, record_type);
579 /* Globally initialize the record first. If this is a rep'ed record,
580 that just means some initializations; otherwise, layout the record. */
583 TYPE_ALIGN (record_type) = MAX (BITS_PER_UNIT, TYPE_ALIGN (record_type));
584 SET_TYPE_MODE (record_type, BLKmode);
587 TYPE_SIZE_UNIT (record_type) = size_zero_node;
589 TYPE_SIZE (record_type) = bitsize_zero_node;
591 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
592 out just like a UNION_TYPE, since the size will be fixed. */
593 else if (code == QUAL_UNION_TYPE)
598 /* Ensure there isn't a size already set. There can be in an error
599 case where there is a rep clause but all fields have errors and
600 no longer have a position. */
601 TYPE_SIZE (record_type) = 0;
602 layout_type (record_type);
605 /* At this point, the position and size of each field is known. It was
606 either set before entry by a rep clause, or by laying out the type above.
608 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
609 to compute the Ada size; the GCC size and alignment (for rep'ed records
610 that are not padding types); and the mode (for rep'ed records). We also
611 clear the DECL_BIT_FIELD indication for the cases we know have not been
612 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
614 if (code == QUAL_UNION_TYPE)
615 fieldlist = nreverse (fieldlist);
617 for (field = fieldlist; field; field = TREE_CHAIN (field))
619 tree type = TREE_TYPE (field);
620 tree pos = bit_position (field);
621 tree this_size = DECL_SIZE (field);
624 if ((TREE_CODE (type) == RECORD_TYPE
625 || TREE_CODE (type) == UNION_TYPE
626 || TREE_CODE (type) == QUAL_UNION_TYPE)
627 && !TYPE_IS_FAT_POINTER_P (type)
628 && !TYPE_CONTAINS_TEMPLATE_P (type)
629 && TYPE_ADA_SIZE (type))
630 this_ada_size = TYPE_ADA_SIZE (type);
632 this_ada_size = this_size;
634 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
635 if (DECL_BIT_FIELD (field)
636 && operand_equal_p (this_size, TYPE_SIZE (type), 0))
638 unsigned int align = TYPE_ALIGN (type);
640 /* In the general case, type alignment is required. */
641 if (value_factor_p (pos, align))
643 /* The enclosing record type must be sufficiently aligned.
644 Otherwise, if no alignment was specified for it and it
645 has been laid out already, bump its alignment to the
646 desired one if this is compatible with its size. */
647 if (TYPE_ALIGN (record_type) >= align)
649 DECL_ALIGN (field) = MAX (DECL_ALIGN (field), align);
650 DECL_BIT_FIELD (field) = 0;
654 && value_factor_p (TYPE_SIZE (record_type), align))
656 TYPE_ALIGN (record_type) = align;
657 DECL_ALIGN (field) = MAX (DECL_ALIGN (field), align);
658 DECL_BIT_FIELD (field) = 0;
662 /* In the non-strict alignment case, only byte alignment is. */
663 if (!STRICT_ALIGNMENT
664 && DECL_BIT_FIELD (field)
665 && value_factor_p (pos, BITS_PER_UNIT))
666 DECL_BIT_FIELD (field) = 0;
669 /* If we still have DECL_BIT_FIELD set at this point, we know the field
670 is technically not addressable. Except that it can actually be
671 addressed if the field is BLKmode and happens to be properly
673 DECL_NONADDRESSABLE_P (field)
674 |= DECL_BIT_FIELD (field) && DECL_MODE (field) != BLKmode;
676 /* A type must be as aligned as its most aligned field that is not
677 a bit-field. But this is already enforced by layout_type. */
678 if (rep_level > 0 && !DECL_BIT_FIELD (field))
679 TYPE_ALIGN (record_type)
680 = MAX (TYPE_ALIGN (record_type), DECL_ALIGN (field));
685 ada_size = size_binop (MAX_EXPR, ada_size, this_ada_size);
686 size = size_binop (MAX_EXPR, size, this_size);
689 case QUAL_UNION_TYPE:
691 = fold_build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
692 this_ada_size, ada_size);
693 size = fold_build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
698 /* Since we know here that all fields are sorted in order of
699 increasing bit position, the size of the record is one
700 higher than the ending bit of the last field processed
701 unless we have a rep clause, since in that case we might
702 have a field outside a QUAL_UNION_TYPE that has a higher ending
703 position. So use a MAX in that case. Also, if this field is a
704 QUAL_UNION_TYPE, we need to take into account the previous size in
705 the case of empty variants. */
707 = merge_sizes (ada_size, pos, this_ada_size,
708 TREE_CODE (type) == QUAL_UNION_TYPE, rep_level > 0);
710 = merge_sizes (size, pos, this_size,
711 TREE_CODE (type) == QUAL_UNION_TYPE, rep_level > 0);
719 if (code == QUAL_UNION_TYPE)
720 nreverse (fieldlist);
722 /* If the type is discriminated, it can be used to access all its
723 constrained subtypes, so force structural equality checks. */
724 if (CONTAINS_PLACEHOLDER_P (size))
725 SET_TYPE_STRUCTURAL_EQUALITY (record_type);
729 /* If this is a padding record, we never want to make the size smaller
730 than what was specified in it, if any. */
731 if (TREE_CODE (record_type) == RECORD_TYPE
732 && TYPE_IS_PADDING_P (record_type) && TYPE_SIZE (record_type))
733 size = TYPE_SIZE (record_type);
735 /* Now set any of the values we've just computed that apply. */
736 if (!TYPE_IS_FAT_POINTER_P (record_type)
737 && !TYPE_CONTAINS_TEMPLATE_P (record_type))
738 SET_TYPE_ADA_SIZE (record_type, ada_size);
742 tree size_unit = had_size_unit
743 ? TYPE_SIZE_UNIT (record_type)
745 size_binop (CEIL_DIV_EXPR, size,
747 unsigned int align = TYPE_ALIGN (record_type);
749 TYPE_SIZE (record_type) = variable_size (round_up (size, align));
750 TYPE_SIZE_UNIT (record_type)
751 = variable_size (round_up (size_unit, align / BITS_PER_UNIT));
753 compute_record_mode (record_type);
757 if (!do_not_finalize)
758 rest_of_record_type_compilation (record_type);
761 /* Wrap up compilation of RECORD_TYPE, i.e. most notably output all
762 the debug information associated with it. It need not be invoked
763 directly in most cases since finish_record_type takes care of doing
764 so, unless explicitly requested not to through DO_NOT_FINALIZE. */
767 rest_of_record_type_compilation (tree record_type)
769 tree fieldlist = TYPE_FIELDS (record_type);
771 enum tree_code code = TREE_CODE (record_type);
772 bool var_size = false;
774 for (field = fieldlist; field; field = TREE_CHAIN (field))
776 /* We need to make an XVE/XVU record if any field has variable size,
777 whether or not the record does. For example, if we have a union,
778 it may be that all fields, rounded up to the alignment, have the
779 same size, in which case we'll use that size. But the debug
780 output routines (except Dwarf2) won't be able to output the fields,
781 so we need to make the special record. */
782 if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST
783 /* If a field has a non-constant qualifier, the record will have
784 variable size too. */
785 || (code == QUAL_UNION_TYPE
786 && TREE_CODE (DECL_QUALIFIER (field)) != INTEGER_CST))
793 /* If this record is of variable size, rename it so that the
794 debugger knows it is and make a new, parallel, record
795 that tells the debugger how the record is laid out. See
796 exp_dbug.ads. But don't do this for records that are padding
797 since they confuse GDB. */
799 && !(TREE_CODE (record_type) == RECORD_TYPE
800 && TYPE_IS_PADDING_P (record_type)))
803 = make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE
804 ? UNION_TYPE : TREE_CODE (record_type));
805 tree orig_name = TYPE_NAME (record_type);
807 = (TREE_CODE (orig_name) == TYPE_DECL ? DECL_NAME (orig_name)
810 = concat_id_with_name (orig_id,
811 TREE_CODE (record_type) == QUAL_UNION_TYPE
813 tree last_pos = bitsize_zero_node;
815 tree prev_old_field = 0;
817 TYPE_NAME (new_record_type) = new_id;
818 TYPE_ALIGN (new_record_type) = BIGGEST_ALIGNMENT;
819 TYPE_STUB_DECL (new_record_type)
820 = create_type_stub_decl (new_id, new_record_type);
821 DECL_IGNORED_P (TYPE_STUB_DECL (new_record_type))
822 = DECL_IGNORED_P (TYPE_STUB_DECL (record_type));
823 TYPE_SIZE (new_record_type) = size_int (TYPE_ALIGN (record_type));
824 TYPE_SIZE_UNIT (new_record_type)
825 = size_int (TYPE_ALIGN (record_type) / BITS_PER_UNIT);
827 add_parallel_type (TYPE_STUB_DECL (record_type), new_record_type);
829 /* Now scan all the fields, replacing each field with a new
830 field corresponding to the new encoding. */
831 for (old_field = TYPE_FIELDS (record_type); old_field;
832 old_field = TREE_CHAIN (old_field))
834 tree field_type = TREE_TYPE (old_field);
835 tree field_name = DECL_NAME (old_field);
837 tree curpos = bit_position (old_field);
839 unsigned int align = 0;
842 /* See how the position was modified from the last position.
844 There are two basic cases we support: a value was added
845 to the last position or the last position was rounded to
846 a boundary and they something was added. Check for the
847 first case first. If not, see if there is any evidence
848 of rounding. If so, round the last position and try
851 If this is a union, the position can be taken as zero. */
853 /* Some computations depend on the shape of the position expression,
854 so strip conversions to make sure it's exposed. */
855 curpos = remove_conversions (curpos, true);
857 if (TREE_CODE (new_record_type) == UNION_TYPE)
858 pos = bitsize_zero_node, align = 0;
860 pos = compute_related_constant (curpos, last_pos);
862 if (!pos && TREE_CODE (curpos) == MULT_EXPR
863 && host_integerp (TREE_OPERAND (curpos, 1), 1))
865 tree offset = TREE_OPERAND (curpos, 0);
866 align = tree_low_cst (TREE_OPERAND (curpos, 1), 1);
868 /* An offset which is a bitwise AND with a negative power of 2
869 means an alignment corresponding to this power of 2. */
870 offset = remove_conversions (offset, true);
871 if (TREE_CODE (offset) == BIT_AND_EXPR
872 && host_integerp (TREE_OPERAND (offset, 1), 0)
873 && tree_int_cst_sgn (TREE_OPERAND (offset, 1)) < 0)
876 = - tree_low_cst (TREE_OPERAND (offset, 1), 0);
877 if (exact_log2 (pow) > 0)
881 pos = compute_related_constant (curpos,
882 round_up (last_pos, align));
884 else if (!pos && TREE_CODE (curpos) == PLUS_EXPR
885 && TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST
886 && TREE_CODE (TREE_OPERAND (curpos, 0)) == MULT_EXPR
887 && host_integerp (TREE_OPERAND
888 (TREE_OPERAND (curpos, 0), 1),
893 (TREE_OPERAND (TREE_OPERAND (curpos, 0), 1), 1);
894 pos = compute_related_constant (curpos,
895 round_up (last_pos, align));
897 else if (potential_alignment_gap (prev_old_field, old_field,
900 align = TYPE_ALIGN (field_type);
901 pos = compute_related_constant (curpos,
902 round_up (last_pos, align));
905 /* If we can't compute a position, set it to zero.
907 ??? We really should abort here, but it's too much work
908 to get this correct for all cases. */
911 pos = bitsize_zero_node;
913 /* See if this type is variable-sized and make a pointer type
914 and indicate the indirection if so. Beware that the debug
915 back-end may adjust the position computed above according
916 to the alignment of the field type, i.e. the pointer type
917 in this case, if we don't preventively counter that. */
918 if (TREE_CODE (DECL_SIZE (old_field)) != INTEGER_CST)
920 field_type = build_pointer_type (field_type);
921 if (align != 0 && TYPE_ALIGN (field_type) > align)
923 field_type = copy_node (field_type);
924 TYPE_ALIGN (field_type) = align;
929 /* Make a new field name, if necessary. */
930 if (var || align != 0)
935 sprintf (suffix, "XV%c%u", var ? 'L' : 'A',
936 align / BITS_PER_UNIT);
938 strcpy (suffix, "XVL");
940 field_name = concat_id_with_name (field_name, suffix);
943 new_field = create_field_decl (field_name, field_type,
945 DECL_SIZE (old_field), pos, 0);
946 TREE_CHAIN (new_field) = TYPE_FIELDS (new_record_type);
947 TYPE_FIELDS (new_record_type) = new_field;
949 /* If old_field is a QUAL_UNION_TYPE, take its size as being
950 zero. The only time it's not the last field of the record
951 is when there are other components at fixed positions after
952 it (meaning there was a rep clause for every field) and we
953 want to be able to encode them. */
954 last_pos = size_binop (PLUS_EXPR, bit_position (old_field),
955 (TREE_CODE (TREE_TYPE (old_field))
958 : DECL_SIZE (old_field));
959 prev_old_field = old_field;
962 TYPE_FIELDS (new_record_type)
963 = nreverse (TYPE_FIELDS (new_record_type));
965 rest_of_type_decl_compilation (TYPE_STUB_DECL (new_record_type));
968 rest_of_type_decl_compilation (TYPE_STUB_DECL (record_type));
971 /* Append PARALLEL_TYPE on the chain of parallel types for decl. */
974 add_parallel_type (tree decl, tree parallel_type)
978 while (DECL_PARALLEL_TYPE (d))
979 d = TYPE_STUB_DECL (DECL_PARALLEL_TYPE (d));
981 SET_DECL_PARALLEL_TYPE (d, parallel_type);
984 /* Return the parallel type associated to a type, if any. */
987 get_parallel_type (tree type)
989 if (TYPE_STUB_DECL (type))
990 return DECL_PARALLEL_TYPE (TYPE_STUB_DECL (type));
995 /* Utility function of above to merge LAST_SIZE, the previous size of a record
996 with FIRST_BIT and SIZE that describe a field. SPECIAL is true if this
997 represents a QUAL_UNION_TYPE in which case we must look for COND_EXPRs and
998 replace a value of zero with the old size. If HAS_REP is true, we take the
999 MAX of the end position of this field with LAST_SIZE. In all other cases,
1000 we use FIRST_BIT plus SIZE. Return an expression for the size. */
1003 merge_sizes (tree last_size, tree first_bit, tree size, bool special,
1006 tree type = TREE_TYPE (last_size);
1009 if (!special || TREE_CODE (size) != COND_EXPR)
1011 new = size_binop (PLUS_EXPR, first_bit, size);
1013 new = size_binop (MAX_EXPR, last_size, new);
1017 new = fold_build3 (COND_EXPR, type, TREE_OPERAND (size, 0),
1018 integer_zerop (TREE_OPERAND (size, 1))
1019 ? last_size : merge_sizes (last_size, first_bit,
1020 TREE_OPERAND (size, 1),
1022 integer_zerop (TREE_OPERAND (size, 2))
1023 ? last_size : merge_sizes (last_size, first_bit,
1024 TREE_OPERAND (size, 2),
1027 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
1028 when fed through substitute_in_expr) into thinking that a constant
1029 size is not constant. */
1030 while (TREE_CODE (new) == NON_LVALUE_EXPR)
1031 new = TREE_OPERAND (new, 0);
1036 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
1037 related by the addition of a constant. Return that constant if so. */
1040 compute_related_constant (tree op0, tree op1)
1042 tree op0_var, op1_var;
1043 tree op0_con = split_plus (op0, &op0_var);
1044 tree op1_con = split_plus (op1, &op1_var);
1045 tree result = size_binop (MINUS_EXPR, op0_con, op1_con);
1047 if (operand_equal_p (op0_var, op1_var, 0))
1049 else if (operand_equal_p (op0, size_binop (PLUS_EXPR, op1_var, result), 0))
1055 /* Utility function of above to split a tree OP which may be a sum, into a
1056 constant part, which is returned, and a variable part, which is stored
1057 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
1061 split_plus (tree in, tree *pvar)
1063 /* Strip NOPS in order to ease the tree traversal and maximize the
1064 potential for constant or plus/minus discovery. We need to be careful
1065 to always return and set *pvar to bitsizetype trees, but it's worth
1069 *pvar = convert (bitsizetype, in);
1071 if (TREE_CODE (in) == INTEGER_CST)
1073 *pvar = bitsize_zero_node;
1074 return convert (bitsizetype, in);
1076 else if (TREE_CODE (in) == PLUS_EXPR || TREE_CODE (in) == MINUS_EXPR)
1078 tree lhs_var, rhs_var;
1079 tree lhs_con = split_plus (TREE_OPERAND (in, 0), &lhs_var);
1080 tree rhs_con = split_plus (TREE_OPERAND (in, 1), &rhs_var);
1082 if (lhs_var == TREE_OPERAND (in, 0)
1083 && rhs_var == TREE_OPERAND (in, 1))
1084 return bitsize_zero_node;
1086 *pvar = size_binop (TREE_CODE (in), lhs_var, rhs_var);
1087 return size_binop (TREE_CODE (in), lhs_con, rhs_con);
1090 return bitsize_zero_node;
1093 /* Return a FUNCTION_TYPE node. RETURN_TYPE is the type returned by the
1094 subprogram. If it is void_type_node, then we are dealing with a procedure,
1095 otherwise we are dealing with a function. PARAM_DECL_LIST is a list of
1096 PARM_DECL nodes that are the subprogram arguments. CICO_LIST is the
1097 copy-in/copy-out list to be stored into TYPE_CICO_LIST.
1098 RETURNS_UNCONSTRAINED is true if the function returns an unconstrained
1099 object. RETURNS_BY_REF is true if the function returns by reference.
1100 RETURNS_BY_TARGET_PTR is true if the function is to be passed (as its
1101 first parameter) the address of the place to copy its result. */
1104 create_subprog_type (tree return_type, tree param_decl_list, tree cico_list,
1105 bool returns_unconstrained, bool returns_by_ref,
1106 bool returns_by_target_ptr)
1108 /* A chain of TREE_LIST nodes whose TREE_VALUEs are the data type nodes of
1109 the subprogram formal parameters. This list is generated by traversing the
1110 input list of PARM_DECL nodes. */
1111 tree param_type_list = NULL;
1115 for (param_decl = param_decl_list; param_decl;
1116 param_decl = TREE_CHAIN (param_decl))
1117 param_type_list = tree_cons (NULL_TREE, TREE_TYPE (param_decl),
1120 /* The list of the function parameter types has to be terminated by the void
1121 type to signal to the back-end that we are not dealing with a variable
1122 parameter subprogram, but that the subprogram has a fixed number of
1124 param_type_list = tree_cons (NULL_TREE, void_type_node, param_type_list);
1126 /* The list of argument types has been created in reverse
1128 param_type_list = nreverse (param_type_list);
1130 type = build_function_type (return_type, param_type_list);
1132 /* TYPE may have been shared since GCC hashes types. If it has a CICO_LIST
1133 or the new type should, make a copy of TYPE. Likewise for
1134 RETURNS_UNCONSTRAINED and RETURNS_BY_REF. */
1135 if (TYPE_CI_CO_LIST (type) || cico_list
1136 || TYPE_RETURNS_UNCONSTRAINED_P (type) != returns_unconstrained
1137 || TYPE_RETURNS_BY_REF_P (type) != returns_by_ref
1138 || TYPE_RETURNS_BY_TARGET_PTR_P (type) != returns_by_target_ptr)
1139 type = copy_type (type);
1141 TYPE_CI_CO_LIST (type) = cico_list;
1142 TYPE_RETURNS_UNCONSTRAINED_P (type) = returns_unconstrained;
1143 TYPE_RETURNS_BY_REF_P (type) = returns_by_ref;
1144 TYPE_RETURNS_BY_TARGET_PTR_P (type) = returns_by_target_ptr;
1148 /* Return a copy of TYPE but safe to modify in any way. */
1151 copy_type (tree type)
1153 tree new = copy_node (type);
1155 /* copy_node clears this field instead of copying it, because it is
1156 aliased with TREE_CHAIN. */
1157 TYPE_STUB_DECL (new) = TYPE_STUB_DECL (type);
1159 TYPE_POINTER_TO (new) = 0;
1160 TYPE_REFERENCE_TO (new) = 0;
1161 TYPE_MAIN_VARIANT (new) = new;
1162 TYPE_NEXT_VARIANT (new) = 0;
1167 /* Return an INTEGER_TYPE of SIZETYPE with range MIN to MAX and whose
1168 TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position of
1172 create_index_type (tree min, tree max, tree index, Node_Id gnat_node)
1174 /* First build a type for the desired range. */
1175 tree type = build_index_2_type (min, max);
1177 /* If this type has the TYPE_INDEX_TYPE we want, return it. Otherwise, if it
1178 doesn't have TYPE_INDEX_TYPE set, set it to INDEX. If TYPE_INDEX_TYPE
1179 is set, but not to INDEX, make a copy of this type with the requested
1180 index type. Note that we have no way of sharing these types, but that's
1181 only a small hole. */
1182 if (TYPE_INDEX_TYPE (type) == index)
1184 else if (TYPE_INDEX_TYPE (type))
1185 type = copy_type (type);
1187 SET_TYPE_INDEX_TYPE (type, index);
1188 create_type_decl (NULL_TREE, type, NULL, true, false, gnat_node);
1192 /* Return a TYPE_DECL node suitable for the TYPE_STUB_DECL field of a type.
1193 TYPE_NAME gives the name of the type and TYPE is a ..._TYPE node giving
1197 create_type_stub_decl (tree type_name, tree type)
1199 /* Using a named TYPE_DECL ensures that a type name marker is emitted in
1200 STABS while setting DECL_ARTIFICIAL ensures that no DW_TAG_typedef is
1201 emitted in DWARF. */
1202 tree type_decl = build_decl (TYPE_DECL, type_name, type);
1203 DECL_ARTIFICIAL (type_decl) = 1;
1207 /* Return a TYPE_DECL node. TYPE_NAME gives the name of the type and TYPE
1208 is a ..._TYPE node giving its data type. ARTIFICIAL_P is true if this
1209 is a declaration that was generated by the compiler. DEBUG_INFO_P is
1210 true if we need to write debug information about this type. GNAT_NODE
1211 is used for the position of the decl. */
1214 create_type_decl (tree type_name, tree type, struct attrib *attr_list,
1215 bool artificial_p, bool debug_info_p, Node_Id gnat_node)
1217 enum tree_code code = TREE_CODE (type);
1218 bool named = TYPE_NAME (type) && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL;
1221 /* Only the builtin TYPE_STUB_DECL should be used for dummy types. */
1222 gcc_assert (!TYPE_IS_DUMMY_P (type));
1224 /* If the type hasn't been named yet, we're naming it; preserve an existing
1225 TYPE_STUB_DECL that has been attached to it for some purpose. */
1226 if (!named && TYPE_STUB_DECL (type))
1228 type_decl = TYPE_STUB_DECL (type);
1229 DECL_NAME (type_decl) = type_name;
1232 type_decl = build_decl (TYPE_DECL, type_name, type);
1234 DECL_ARTIFICIAL (type_decl) = artificial_p;
1235 gnat_pushdecl (type_decl, gnat_node);
1236 process_attributes (type_decl, attr_list);
1238 /* If we're naming the type, equate the TYPE_STUB_DECL to the name.
1239 This causes the name to be also viewed as a "tag" by the debug
1240 back-end, with the advantage that no DW_TAG_typedef is emitted
1241 for artificial "tagged" types in DWARF. */
1243 TYPE_STUB_DECL (type) = type_decl;
1245 /* Pass the type declaration to the debug back-end unless this is an
1246 UNCONSTRAINED_ARRAY_TYPE that the back-end does not support, an
1247 ENUMERAL_TYPE or RECORD_TYPE which are handled separately, or a
1248 type for which debugging information was not requested. */
1249 if (code == UNCONSTRAINED_ARRAY_TYPE || !debug_info_p)
1250 DECL_IGNORED_P (type_decl) = 1;
1251 else if (code != ENUMERAL_TYPE
1252 && (code != RECORD_TYPE || TYPE_IS_FAT_POINTER_P (type))
1253 && !((code == POINTER_TYPE || code == REFERENCE_TYPE)
1254 && TYPE_IS_DUMMY_P (TREE_TYPE (type))))
1255 rest_of_type_decl_compilation (type_decl);
1260 /* Return a VAR_DECL or CONST_DECL node.
1262 VAR_NAME gives the name of the variable. ASM_NAME is its assembler name
1263 (if provided). TYPE is its data type (a GCC ..._TYPE node). VAR_INIT is
1264 the GCC tree for an optional initial expression; NULL_TREE if none.
1266 CONST_FLAG is true if this variable is constant, in which case we might
1267 return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false.
1269 PUBLIC_FLAG is true if this is for a reference to a public entity or for a
1270 definition to be made visible outside of the current compilation unit, for
1271 instance variable definitions in a package specification.
1273 EXTERN_FLAG is true when processing an external variable declaration (as
1274 opposed to a definition: no storage is to be allocated for the variable).
1276 STATIC_FLAG is only relevant when not at top level. In that case
1277 it indicates whether to always allocate storage to the variable.
1279 GNAT_NODE is used for the position of the decl. */
1282 create_var_decl_1 (tree var_name, tree asm_name, tree type, tree var_init,
1283 bool const_flag, bool public_flag, bool extern_flag,
1284 bool static_flag, bool const_decl_allowed_p,
1285 struct attrib *attr_list, Node_Id gnat_node)
1289 && gnat_types_compatible_p (type, TREE_TYPE (var_init))
1290 && (global_bindings_p () || static_flag
1291 ? initializer_constant_valid_p (var_init, TREE_TYPE (var_init)) != 0
1292 : TREE_CONSTANT (var_init)));
1294 /* Whether we will make TREE_CONSTANT the DECL we produce here, in which
1295 case the initializer may be used in-lieu of the DECL node (as done in
1296 Identifier_to_gnu). This is useful to prevent the need of elaboration
1297 code when an identifier for which such a decl is made is in turn used as
1298 an initializer. We used to rely on CONST vs VAR_DECL for this purpose,
1299 but extra constraints apply to this choice (see below) and are not
1300 relevant to the distinction we wish to make. */
1301 bool constant_p = const_flag && init_const;
1303 /* The actual DECL node. CONST_DECL was initially intended for enumerals
1304 and may be used for scalars in general but not for aggregates. */
1306 = build_decl ((constant_p && const_decl_allowed_p
1307 && !AGGREGATE_TYPE_P (type)) ? CONST_DECL : VAR_DECL,
1310 /* If this is external, throw away any initializations (they will be done
1311 elsewhere) unless this is a constant for which we would like to remain
1312 able to get the initializer. If we are defining a global here, leave a
1313 constant initialization and save any variable elaborations for the
1314 elaboration routine. If we are just annotating types, throw away the
1315 initialization if it isn't a constant. */
1316 if ((extern_flag && !constant_p)
1317 || (type_annotate_only && var_init && !TREE_CONSTANT (var_init)))
1318 var_init = NULL_TREE;
1320 /* At the global level, an initializer requiring code to be generated
1321 produces elaboration statements. Check that such statements are allowed,
1322 that is, not violating a No_Elaboration_Code restriction. */
1323 if (global_bindings_p () && var_init != 0 && ! init_const)
1324 Check_Elaboration_Code_Allowed (gnat_node);
1326 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
1327 try to fiddle with DECL_COMMON. However, on platforms that don't
1328 support global BSS sections, uninitialized global variables would
1329 go in DATA instead, thus increasing the size of the executable. */
1331 && TREE_CODE (var_decl) == VAR_DECL
1332 && !have_global_bss_p ())
1333 DECL_COMMON (var_decl) = 1;
1334 DECL_INITIAL (var_decl) = var_init;
1335 TREE_READONLY (var_decl) = const_flag;
1336 DECL_EXTERNAL (var_decl) = extern_flag;
1337 TREE_PUBLIC (var_decl) = public_flag || extern_flag;
1338 TREE_CONSTANT (var_decl) = constant_p;
1339 TREE_THIS_VOLATILE (var_decl) = TREE_SIDE_EFFECTS (var_decl)
1340 = TYPE_VOLATILE (type);
1342 /* If it's public and not external, always allocate storage for it.
1343 At the global binding level we need to allocate static storage for the
1344 variable if and only if it's not external. If we are not at the top level
1345 we allocate automatic storage unless requested not to. */
1346 TREE_STATIC (var_decl)
1347 = !extern_flag && (public_flag || static_flag || global_bindings_p ());
1349 if (asm_name && VAR_OR_FUNCTION_DECL_P (var_decl))
1350 SET_DECL_ASSEMBLER_NAME (var_decl, asm_name);
1352 process_attributes (var_decl, attr_list);
1354 /* Add this decl to the current binding level. */
1355 gnat_pushdecl (var_decl, gnat_node);
1357 if (TREE_SIDE_EFFECTS (var_decl))
1358 TREE_ADDRESSABLE (var_decl) = 1;
1360 if (TREE_CODE (var_decl) != CONST_DECL)
1362 if (global_bindings_p ())
1363 rest_of_decl_compilation (var_decl, true, 0);
1366 expand_decl (var_decl);
1371 /* Return true if TYPE, an aggregate type, contains (or is) an array. */
1374 aggregate_type_contains_array_p (tree type)
1376 switch (TREE_CODE (type))
1380 case QUAL_UNION_TYPE:
1383 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1384 if (AGGREGATE_TYPE_P (TREE_TYPE (field))
1385 && aggregate_type_contains_array_p (TREE_TYPE (field)))
1398 /* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its
1399 type, and RECORD_TYPE is the type of the parent. PACKED is nonzero if
1400 this field is in a record type with a "pragma pack". If SIZE is nonzero
1401 it is the specified size for this field. If POS is nonzero, it is the bit
1402 position. If ADDRESSABLE is nonzero, it means we are allowed to take
1403 the address of this field for aliasing purposes. If it is negative, we
1404 should not make a bitfield, which is used by make_aligning_type. */
1407 create_field_decl (tree field_name, tree field_type, tree record_type,
1408 int packed, tree size, tree pos, int addressable)
1410 tree field_decl = build_decl (FIELD_DECL, field_name, field_type);
1412 DECL_CONTEXT (field_decl) = record_type;
1413 TREE_READONLY (field_decl) = TYPE_READONLY (field_type);
1415 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
1416 byte boundary since GCC cannot handle less-aligned BLKmode bitfields.
1417 Likewise for an aggregate without specified position that contains an
1418 array, because in this case slices of variable length of this array
1419 must be handled by GCC and variable-sized objects need to be aligned
1420 to at least a byte boundary. */
1421 if (packed && (TYPE_MODE (field_type) == BLKmode
1423 && AGGREGATE_TYPE_P (field_type)
1424 && aggregate_type_contains_array_p (field_type))))
1425 DECL_ALIGN (field_decl) = BITS_PER_UNIT;
1427 /* If a size is specified, use it. Otherwise, if the record type is packed
1428 compute a size to use, which may differ from the object's natural size.
1429 We always set a size in this case to trigger the checks for bitfield
1430 creation below, which is typically required when no position has been
1433 size = convert (bitsizetype, size);
1434 else if (packed == 1)
1436 size = rm_size (field_type);
1438 /* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to
1440 if (TREE_CODE (size) == INTEGER_CST
1441 && compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0)
1442 size = round_up (size, BITS_PER_UNIT);
1445 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
1446 specified for two reasons: first if the size differs from the natural
1447 size. Second, if the alignment is insufficient. There are a number of
1448 ways the latter can be true.
1450 We never make a bitfield if the type of the field has a nonconstant size,
1451 because no such entity requiring bitfield operations should reach here.
1453 We do *preventively* make a bitfield when there might be the need for it
1454 but we don't have all the necessary information to decide, as is the case
1455 of a field with no specified position in a packed record.
1457 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
1458 in layout_decl or finish_record_type to clear the bit_field indication if
1459 it is in fact not needed. */
1460 if (addressable >= 0
1462 && TREE_CODE (size) == INTEGER_CST
1463 && TREE_CODE (TYPE_SIZE (field_type)) == INTEGER_CST
1464 && (!tree_int_cst_equal (size, TYPE_SIZE (field_type))
1465 || (pos && !value_factor_p (pos, TYPE_ALIGN (field_type)))
1467 || (TYPE_ALIGN (record_type) != 0
1468 && TYPE_ALIGN (record_type) < TYPE_ALIGN (field_type))))
1470 DECL_BIT_FIELD (field_decl) = 1;
1471 DECL_SIZE (field_decl) = size;
1472 if (!packed && !pos)
1473 DECL_ALIGN (field_decl)
1474 = (TYPE_ALIGN (record_type) != 0
1475 ? MIN (TYPE_ALIGN (record_type), TYPE_ALIGN (field_type))
1476 : TYPE_ALIGN (field_type));
1479 DECL_PACKED (field_decl) = pos ? DECL_BIT_FIELD (field_decl) : packed;
1481 /* Bump the alignment if need be, either for bitfield/packing purposes or
1482 to satisfy the type requirements if no such consideration applies. When
1483 we get the alignment from the type, indicate if this is from an explicit
1484 user request, which prevents stor-layout from lowering it later on. */
1486 unsigned int bit_align
1487 = (DECL_BIT_FIELD (field_decl) ? 1
1488 : packed && TYPE_MODE (field_type) != BLKmode ? BITS_PER_UNIT : 0);
1490 if (bit_align > DECL_ALIGN (field_decl))
1491 DECL_ALIGN (field_decl) = bit_align;
1492 else if (!bit_align && TYPE_ALIGN (field_type) > DECL_ALIGN (field_decl))
1494 DECL_ALIGN (field_decl) = TYPE_ALIGN (field_type);
1495 DECL_USER_ALIGN (field_decl) = TYPE_USER_ALIGN (field_type);
1501 /* We need to pass in the alignment the DECL is known to have.
1502 This is the lowest-order bit set in POS, but no more than
1503 the alignment of the record, if one is specified. Note
1504 that an alignment of 0 is taken as infinite. */
1505 unsigned int known_align;
1507 if (host_integerp (pos, 1))
1508 known_align = tree_low_cst (pos, 1) & - tree_low_cst (pos, 1);
1510 known_align = BITS_PER_UNIT;
1512 if (TYPE_ALIGN (record_type)
1513 && (known_align == 0 || known_align > TYPE_ALIGN (record_type)))
1514 known_align = TYPE_ALIGN (record_type);
1516 layout_decl (field_decl, known_align);
1517 SET_DECL_OFFSET_ALIGN (field_decl,
1518 host_integerp (pos, 1) ? BIGGEST_ALIGNMENT
1520 pos_from_bit (&DECL_FIELD_OFFSET (field_decl),
1521 &DECL_FIELD_BIT_OFFSET (field_decl),
1522 DECL_OFFSET_ALIGN (field_decl), pos);
1524 DECL_HAS_REP_P (field_decl) = 1;
1527 /* In addition to what our caller says, claim the field is addressable if we
1528 know that its type is not suitable.
1530 The field may also be "technically" nonaddressable, meaning that even if
1531 we attempt to take the field's address we will actually get the address
1532 of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD
1533 value we have at this point is not accurate enough, so we don't account
1534 for this here and let finish_record_type decide. */
1535 if (!addressable && !type_for_nonaliased_component_p (field_type))
1538 DECL_NONADDRESSABLE_P (field_decl) = !addressable;
1543 /* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter,
1544 PARAM_TYPE is its type. READONLY is true if the parameter is
1545 readonly (either an In parameter or an address of a pass-by-ref
1549 create_param_decl (tree param_name, tree param_type, bool readonly)
1551 tree param_decl = build_decl (PARM_DECL, param_name, param_type);
1553 /* Honor targetm.calls.promote_prototypes(), as not doing so can
1554 lead to various ABI violations. */
1555 if (targetm.calls.promote_prototypes (param_type)
1556 && (TREE_CODE (param_type) == INTEGER_TYPE
1557 || TREE_CODE (param_type) == ENUMERAL_TYPE
1558 || TREE_CODE (param_type) == BOOLEAN_TYPE)
1559 && TYPE_PRECISION (param_type) < TYPE_PRECISION (integer_type_node))
1561 /* We have to be careful about biased types here. Make a subtype
1562 of integer_type_node with the proper biasing. */
1563 if (TREE_CODE (param_type) == INTEGER_TYPE
1564 && TYPE_BIASED_REPRESENTATION_P (param_type))
1567 = copy_type (build_range_type (integer_type_node,
1568 TYPE_MIN_VALUE (param_type),
1569 TYPE_MAX_VALUE (param_type)));
1571 TYPE_BIASED_REPRESENTATION_P (param_type) = 1;
1574 param_type = integer_type_node;
1577 DECL_ARG_TYPE (param_decl) = param_type;
1578 TREE_READONLY (param_decl) = readonly;
1582 /* Given a DECL and ATTR_LIST, process the listed attributes. */
1585 process_attributes (tree decl, struct attrib *attr_list)
1587 for (; attr_list; attr_list = attr_list->next)
1588 switch (attr_list->type)
1590 case ATTR_MACHINE_ATTRIBUTE:
1591 decl_attributes (&decl, tree_cons (attr_list->name, attr_list->args,
1593 ATTR_FLAG_TYPE_IN_PLACE);
1596 case ATTR_LINK_ALIAS:
1597 if (! DECL_EXTERNAL (decl))
1599 TREE_STATIC (decl) = 1;
1600 assemble_alias (decl, attr_list->name);
1604 case ATTR_WEAK_EXTERNAL:
1606 declare_weak (decl);
1608 post_error ("?weak declarations not supported on this target",
1609 attr_list->error_point);
1612 case ATTR_LINK_SECTION:
1613 if (targetm.have_named_sections)
1615 DECL_SECTION_NAME (decl)
1616 = build_string (IDENTIFIER_LENGTH (attr_list->name),
1617 IDENTIFIER_POINTER (attr_list->name));
1618 DECL_COMMON (decl) = 0;
1621 post_error ("?section attributes are not supported for this target",
1622 attr_list->error_point);
1625 case ATTR_LINK_CONSTRUCTOR:
1626 DECL_STATIC_CONSTRUCTOR (decl) = 1;
1627 TREE_USED (decl) = 1;
1630 case ATTR_LINK_DESTRUCTOR:
1631 DECL_STATIC_DESTRUCTOR (decl) = 1;
1632 TREE_USED (decl) = 1;
1635 case ATTR_THREAD_LOCAL_STORAGE:
1636 if (targetm.have_tls)
1637 DECL_TLS_MODEL (decl) = decl_default_tls_model (decl);
1639 post_error ("thread-local storage not supported for this target",
1640 attr_list->error_point);
1645 /* Record a global renaming pointer. */
1648 record_global_renaming_pointer (tree decl)
1650 gcc_assert (DECL_RENAMED_OBJECT (decl));
1651 VEC_safe_push (tree, gc, global_renaming_pointers, decl);
1654 /* Invalidate the global renaming pointers. */
1657 invalidate_global_renaming_pointers (void)
1662 for (i = 0; VEC_iterate(tree, global_renaming_pointers, i, iter); i++)
1663 SET_DECL_RENAMED_OBJECT (iter, NULL_TREE);
1665 VEC_free (tree, gc, global_renaming_pointers);
1668 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
1672 value_factor_p (tree value, HOST_WIDE_INT factor)
1674 if (host_integerp (value, 1))
1675 return tree_low_cst (value, 1) % factor == 0;
1677 if (TREE_CODE (value) == MULT_EXPR)
1678 return (value_factor_p (TREE_OPERAND (value, 0), factor)
1679 || value_factor_p (TREE_OPERAND (value, 1), factor));
1684 /* Given 2 consecutive field decls PREV_FIELD and CURR_FIELD, return true
1685 unless we can prove these 2 fields are laid out in such a way that no gap
1686 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
1687 is the distance in bits between the end of PREV_FIELD and the starting
1688 position of CURR_FIELD. It is ignored if null. */
1691 potential_alignment_gap (tree prev_field, tree curr_field, tree offset)
1693 /* If this is the first field of the record, there cannot be any gap */
1697 /* If the previous field is a union type, then return False: The only
1698 time when such a field is not the last field of the record is when
1699 there are other components at fixed positions after it (meaning there
1700 was a rep clause for every field), in which case we don't want the
1701 alignment constraint to override them. */
1702 if (TREE_CODE (TREE_TYPE (prev_field)) == QUAL_UNION_TYPE)
1705 /* If the distance between the end of prev_field and the beginning of
1706 curr_field is constant, then there is a gap if the value of this
1707 constant is not null. */
1708 if (offset && host_integerp (offset, 1))
1709 return !integer_zerop (offset);
1711 /* If the size and position of the previous field are constant,
1712 then check the sum of this size and position. There will be a gap
1713 iff it is not multiple of the current field alignment. */
1714 if (host_integerp (DECL_SIZE (prev_field), 1)
1715 && host_integerp (bit_position (prev_field), 1))
1716 return ((tree_low_cst (bit_position (prev_field), 1)
1717 + tree_low_cst (DECL_SIZE (prev_field), 1))
1718 % DECL_ALIGN (curr_field) != 0);
1720 /* If both the position and size of the previous field are multiples
1721 of the current field alignment, there cannot be any gap. */
1722 if (value_factor_p (bit_position (prev_field), DECL_ALIGN (curr_field))
1723 && value_factor_p (DECL_SIZE (prev_field), DECL_ALIGN (curr_field)))
1726 /* Fallback, return that there may be a potential gap */
1730 /* Returns a LABEL_DECL node for LABEL_NAME. */
1733 create_label_decl (tree label_name)
1735 tree label_decl = build_decl (LABEL_DECL, label_name, void_type_node);
1737 DECL_CONTEXT (label_decl) = current_function_decl;
1738 DECL_MODE (label_decl) = VOIDmode;
1739 DECL_SOURCE_LOCATION (label_decl) = input_location;
1744 /* Returns a FUNCTION_DECL node. SUBPROG_NAME is the name of the subprogram,
1745 ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE
1746 node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of
1747 PARM_DECL nodes chained through the TREE_CHAIN field).
1749 INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, and ATTR_LIST are used to set the
1750 appropriate fields in the FUNCTION_DECL. GNAT_NODE gives the location. */
1753 create_subprog_decl (tree subprog_name, tree asm_name,
1754 tree subprog_type, tree param_decl_list, bool inline_flag,
1755 bool public_flag, bool extern_flag,
1756 struct attrib *attr_list, Node_Id gnat_node)
1758 tree return_type = TREE_TYPE (subprog_type);
1759 tree subprog_decl = build_decl (FUNCTION_DECL, subprog_name, subprog_type);
1761 /* If this is a non-inline function nested inside an inlined external
1762 function, we cannot honor both requests without cloning the nested
1763 function in the current unit since it is private to the other unit.
1764 We could inline the nested function as well but it's probably better
1765 to err on the side of too little inlining. */
1767 && current_function_decl
1768 && DECL_DECLARED_INLINE_P (current_function_decl)
1769 && DECL_EXTERNAL (current_function_decl))
1770 DECL_DECLARED_INLINE_P (current_function_decl) = 0;
1772 DECL_EXTERNAL (subprog_decl) = extern_flag;
1773 TREE_PUBLIC (subprog_decl) = public_flag;
1774 TREE_STATIC (subprog_decl) = 1;
1775 TREE_READONLY (subprog_decl) = TYPE_READONLY (subprog_type);
1776 TREE_THIS_VOLATILE (subprog_decl) = TYPE_VOLATILE (subprog_type);
1777 TREE_SIDE_EFFECTS (subprog_decl) = TYPE_VOLATILE (subprog_type);
1778 DECL_DECLARED_INLINE_P (subprog_decl) = inline_flag;
1779 DECL_ARGUMENTS (subprog_decl) = param_decl_list;
1780 DECL_RESULT (subprog_decl) = build_decl (RESULT_DECL, 0, return_type);
1781 DECL_ARTIFICIAL (DECL_RESULT (subprog_decl)) = 1;
1782 DECL_IGNORED_P (DECL_RESULT (subprog_decl)) = 1;
1784 /* TREE_ADDRESSABLE is set on the result type to request the use of the
1785 target by-reference return mechanism. This is not supported all the
1786 way down to RTL expansion with GCC 4, which ICEs on temporary creation
1787 attempts with such a type and expects DECL_BY_REFERENCE to be set on
1788 the RESULT_DECL instead - see gnat_genericize for more details. */
1789 if (TREE_ADDRESSABLE (TREE_TYPE (DECL_RESULT (subprog_decl))))
1791 tree result_decl = DECL_RESULT (subprog_decl);
1793 TREE_ADDRESSABLE (TREE_TYPE (result_decl)) = 0;
1794 DECL_BY_REFERENCE (result_decl) = 1;
1799 SET_DECL_ASSEMBLER_NAME (subprog_decl, asm_name);
1801 /* The expand_main_function circuitry expects "main_identifier_node" to
1802 designate the DECL_NAME of the 'main' entry point, in turn expected
1803 to be declared as the "main" function literally by default. Ada
1804 program entry points are typically declared with a different name
1805 within the binder generated file, exported as 'main' to satisfy the
1806 system expectations. Redirect main_identifier_node in this case. */
1807 if (asm_name == main_identifier_node)
1808 main_identifier_node = DECL_NAME (subprog_decl);
1811 process_attributes (subprog_decl, attr_list);
1813 /* Add this decl to the current binding level. */
1814 gnat_pushdecl (subprog_decl, gnat_node);
1816 /* Output the assembler code and/or RTL for the declaration. */
1817 rest_of_decl_compilation (subprog_decl, global_bindings_p (), 0);
1819 return subprog_decl;
1822 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
1823 body. This routine needs to be invoked before processing the declarations
1824 appearing in the subprogram. */
1827 begin_subprog_body (tree subprog_decl)
1831 current_function_decl = subprog_decl;
1832 announce_function (subprog_decl);
1834 /* Enter a new binding level and show that all the parameters belong to
1837 for (param_decl = DECL_ARGUMENTS (subprog_decl); param_decl;
1838 param_decl = TREE_CHAIN (param_decl))
1839 DECL_CONTEXT (param_decl) = subprog_decl;
1841 make_decl_rtl (subprog_decl);
1843 /* We handle pending sizes via the elaboration of types, so we don't need to
1844 save them. This causes them to be marked as part of the outer function
1845 and then discarded. */
1846 get_pending_sizes ();
1850 /* Helper for the genericization callback. Return a dereference of VAL
1851 if it is of a reference type. */
1854 convert_from_reference (tree val)
1856 tree value_type, ref;
1858 if (TREE_CODE (TREE_TYPE (val)) != REFERENCE_TYPE)
1861 value_type = TREE_TYPE (TREE_TYPE (val));
1862 ref = build1 (INDIRECT_REF, value_type, val);
1864 /* See if what we reference is CONST or VOLATILE, which requires
1865 looking into array types to get to the component type. */
1867 while (TREE_CODE (value_type) == ARRAY_TYPE)
1868 value_type = TREE_TYPE (value_type);
1871 = (TYPE_QUALS (value_type) & TYPE_QUAL_CONST);
1872 TREE_THIS_VOLATILE (ref)
1873 = (TYPE_QUALS (value_type) & TYPE_QUAL_VOLATILE);
1875 TREE_SIDE_EFFECTS (ref)
1876 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (val));
1881 /* Helper for the genericization callback. Returns true if T denotes
1882 a RESULT_DECL with DECL_BY_REFERENCE set. */
1885 is_byref_result (tree t)
1887 return (TREE_CODE (t) == RESULT_DECL && DECL_BY_REFERENCE (t));
1891 /* Tree walking callback for gnat_genericize. Currently ...
1893 o Adjust references to the function's DECL_RESULT if it is marked
1894 DECL_BY_REFERENCE and so has had its type turned into a reference
1895 type at the end of the function compilation. */
1898 gnat_genericize_r (tree *stmt_p, int *walk_subtrees, void *data)
1900 /* This implementation is modeled after what the C++ front-end is
1901 doing, basis of the downstream passes behavior. */
1903 tree stmt = *stmt_p;
1904 struct pointer_set_t *p_set = (struct pointer_set_t*) data;
1906 /* If we have a direct mention of the result decl, dereference. */
1907 if (is_byref_result (stmt))
1909 *stmt_p = convert_from_reference (stmt);
1914 /* Otherwise, no need to walk the same tree twice. */
1915 if (pointer_set_contains (p_set, stmt))
1921 /* If we are taking the address of what now is a reference, just get the
1923 if (TREE_CODE (stmt) == ADDR_EXPR
1924 && is_byref_result (TREE_OPERAND (stmt, 0)))
1926 *stmt_p = convert (TREE_TYPE (stmt), TREE_OPERAND (stmt, 0));
1930 /* Don't dereference an by-reference RESULT_DECL inside a RETURN_EXPR. */
1931 else if (TREE_CODE (stmt) == RETURN_EXPR
1932 && TREE_OPERAND (stmt, 0)
1933 && is_byref_result (TREE_OPERAND (stmt, 0)))
1936 /* Don't look inside trees that cannot embed references of interest. */
1937 else if (IS_TYPE_OR_DECL_P (stmt))
1940 pointer_set_insert (p_set, *stmt_p);
1945 /* Perform lowering of Ada trees to GENERIC. In particular:
1947 o Turn a DECL_BY_REFERENCE RESULT_DECL into a real by-reference decl
1948 and adjust all the references to this decl accordingly. */
1951 gnat_genericize (tree fndecl)
1953 /* Prior to GCC 4, an explicit By_Reference result mechanism for a function
1954 was handled by simply setting TREE_ADDRESSABLE on the result type.
1955 Everything required to actually pass by invisible ref using the target
1956 mechanism (e.g. extra parameter) was handled at RTL expansion time.
1958 This doesn't work with GCC 4 any more for several reasons. First, the
1959 gimplification process might need the creation of temporaries of this
1960 type, and the gimplifier ICEs on such attempts. Second, the middle-end
1961 now relies on a different attribute for such cases (DECL_BY_REFERENCE on
1962 RESULT/PARM_DECLs), and expects the user invisible by-reference-ness to
1963 be explicitly accounted for by the front-end in the function body.
1965 We achieve the complete transformation in two steps:
1967 1/ create_subprog_decl performs early attribute tweaks: it clears
1968 TREE_ADDRESSABLE from the result type and sets DECL_BY_REFERENCE on
1969 the result decl. The former ensures that the bit isn't set in the GCC
1970 tree saved for the function, so prevents ICEs on temporary creation.
1971 The latter we use here to trigger the rest of the processing.
1973 2/ This function performs the type transformation on the result decl
1974 and adjusts all the references to this decl from the function body
1977 Clearing TREE_ADDRESSABLE from the type differs from the C++ front-end
1978 strategy, which escapes the gimplifier temporary creation issues by
1979 creating it's own temporaries using TARGET_EXPR nodes. Our way relies
1980 on simple specific support code in aggregate_value_p to look at the
1981 target function result decl explicitly. */
1983 struct pointer_set_t *p_set;
1984 tree decl_result = DECL_RESULT (fndecl);
1986 if (!DECL_BY_REFERENCE (decl_result))
1989 /* Make the DECL_RESULT explicitly by-reference and adjust all the
1990 occurrences in the function body using the common tree-walking facility.
1991 We want to see every occurrence of the result decl to adjust the
1992 referencing tree, so need to use our own pointer set to control which
1993 trees should be visited again or not. */
1995 p_set = pointer_set_create ();
1997 TREE_TYPE (decl_result) = build_reference_type (TREE_TYPE (decl_result));
1998 TREE_ADDRESSABLE (decl_result) = 0;
1999 relayout_decl (decl_result);
2001 walk_tree (&DECL_SAVED_TREE (fndecl), gnat_genericize_r, p_set, NULL);
2003 pointer_set_destroy (p_set);
2006 /* Finish the definition of the current subprogram BODY and compile it all the
2007 way to assembler language output. ELAB_P tells if this is called for an
2008 elaboration routine, to be entirely discarded if empty. */
2011 end_subprog_body (tree body, bool elab_p)
2013 tree fndecl = current_function_decl;
2015 /* Mark the BLOCK for this level as being for this function and pop the
2016 level. Since the vars in it are the parameters, clear them. */
2017 BLOCK_VARS (current_binding_level->block) = 0;
2018 BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl;
2019 DECL_INITIAL (fndecl) = current_binding_level->block;
2022 /* We handle pending sizes via the elaboration of types, so we don't
2023 need to save them. */
2024 get_pending_sizes ();
2026 /* Mark the RESULT_DECL as being in this subprogram. */
2027 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl;
2029 DECL_SAVED_TREE (fndecl) = body;
2031 current_function_decl = DECL_CONTEXT (fndecl);
2034 /* We cannot track the location of errors past this point. */
2035 error_gnat_node = Empty;
2037 /* If we're only annotating types, don't actually compile this function. */
2038 if (type_annotate_only)
2041 /* Perform the required pre-gimplification transformations on the tree. */
2042 gnat_genericize (fndecl);
2044 /* We do different things for nested and non-nested functions.
2045 ??? This should be in cgraph. */
2046 if (!DECL_CONTEXT (fndecl))
2048 gnat_gimplify_function (fndecl);
2050 /* If this is an empty elaboration proc, just discard the node.
2051 Otherwise, compile further. */
2052 if (elab_p && empty_body_p (gimple_body (fndecl)))
2053 cgraph_remove_node (cgraph_node (fndecl));
2055 cgraph_finalize_function (fndecl, false);
2058 /* Register this function with cgraph just far enough to get it
2059 added to our parent's nested function list. */
2060 (void) cgraph_node (fndecl);
2063 /* Convert FNDECL's code to GIMPLE and handle any nested functions. */
2066 gnat_gimplify_function (tree fndecl)
2068 struct cgraph_node *cgn;
2070 dump_function (TDI_original, fndecl);
2071 gimplify_function_tree (fndecl);
2072 dump_function (TDI_generic, fndecl);
2074 /* Convert all nested functions to GIMPLE now. We do things in this order
2075 so that items like VLA sizes are expanded properly in the context of the
2076 correct function. */
2077 cgn = cgraph_node (fndecl);
2078 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
2079 gnat_gimplify_function (cgn->decl);
2083 gnat_builtin_function (tree decl)
2085 gnat_pushdecl (decl, Empty);
2089 /* Return an integer type with the number of bits of precision given by
2090 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
2091 it is a signed type. */
2094 gnat_type_for_size (unsigned precision, int unsignedp)
2099 if (precision <= 2 * MAX_BITS_PER_WORD
2100 && signed_and_unsigned_types[precision][unsignedp])
2101 return signed_and_unsigned_types[precision][unsignedp];
2104 t = make_unsigned_type (precision);
2106 t = make_signed_type (precision);
2108 if (precision <= 2 * MAX_BITS_PER_WORD)
2109 signed_and_unsigned_types[precision][unsignedp] = t;
2113 sprintf (type_name, "%sSIGNED_%d", unsignedp ? "UN" : "", precision);
2114 TYPE_NAME (t) = get_identifier (type_name);
2120 /* Likewise for floating-point types. */
2123 float_type_for_precision (int precision, enum machine_mode mode)
2128 if (float_types[(int) mode])
2129 return float_types[(int) mode];
2131 float_types[(int) mode] = t = make_node (REAL_TYPE);
2132 TYPE_PRECISION (t) = precision;
2135 gcc_assert (TYPE_MODE (t) == mode);
2138 sprintf (type_name, "FLOAT_%d", precision);
2139 TYPE_NAME (t) = get_identifier (type_name);
2145 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
2146 an unsigned type; otherwise a signed type is returned. */
2149 gnat_type_for_mode (enum machine_mode mode, int unsignedp)
2151 if (mode == BLKmode)
2153 else if (mode == VOIDmode)
2154 return void_type_node;
2155 else if (COMPLEX_MODE_P (mode))
2157 else if (SCALAR_FLOAT_MODE_P (mode))
2158 return float_type_for_precision (GET_MODE_PRECISION (mode), mode);
2159 else if (SCALAR_INT_MODE_P (mode))
2160 return gnat_type_for_size (GET_MODE_BITSIZE (mode), unsignedp);
2165 /* Return the unsigned version of a TYPE_NODE, a scalar type. */
2168 gnat_unsigned_type (tree type_node)
2170 tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 1);
2172 if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
2174 type = copy_node (type);
2175 TREE_TYPE (type) = type_node;
2177 else if (TREE_TYPE (type_node)
2178 && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
2179 && TYPE_MODULAR_P (TREE_TYPE (type_node)))
2181 type = copy_node (type);
2182 TREE_TYPE (type) = TREE_TYPE (type_node);
2188 /* Return the signed version of a TYPE_NODE, a scalar type. */
2191 gnat_signed_type (tree type_node)
2193 tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 0);
2195 if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
2197 type = copy_node (type);
2198 TREE_TYPE (type) = type_node;
2200 else if (TREE_TYPE (type_node)
2201 && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
2202 && TYPE_MODULAR_P (TREE_TYPE (type_node)))
2204 type = copy_node (type);
2205 TREE_TYPE (type) = TREE_TYPE (type_node);
2211 /* Return 1 if the types T1 and T2 are compatible, i.e. if they can be
2212 transparently converted to each other. */
2215 gnat_types_compatible_p (tree t1, tree t2)
2217 enum tree_code code;
2219 /* This is the default criterion. */
2220 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
2223 /* We only check structural equivalence here. */
2224 if ((code = TREE_CODE (t1)) != TREE_CODE (t2))
2227 /* Array types are also compatible if they are constrained and have
2228 the same component type and the same domain. */
2229 if (code == ARRAY_TYPE
2230 && TREE_TYPE (t1) == TREE_TYPE (t2)
2231 && (TYPE_DOMAIN (t1) == TYPE_DOMAIN (t2)
2232 || (TYPE_DOMAIN (t1)
2234 && tree_int_cst_equal (TYPE_MIN_VALUE (TYPE_DOMAIN (t1)),
2235 TYPE_MIN_VALUE (TYPE_DOMAIN (t2)))
2236 && tree_int_cst_equal (TYPE_MAX_VALUE (TYPE_DOMAIN (t1)),
2237 TYPE_MAX_VALUE (TYPE_DOMAIN (t2))))))
2240 /* Padding record types are also compatible if they pad the same
2241 type and have the same constant size. */
2242 if (code == RECORD_TYPE
2243 && TYPE_IS_PADDING_P (t1) && TYPE_IS_PADDING_P (t2)
2244 && TREE_TYPE (TYPE_FIELDS (t1)) == TREE_TYPE (TYPE_FIELDS (t2))
2245 && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)))
2251 /* EXP is an expression for the size of an object. If this size contains
2252 discriminant references, replace them with the maximum (if MAX_P) or
2253 minimum (if !MAX_P) possible value of the discriminant. */
2256 max_size (tree exp, bool max_p)
2258 enum tree_code code = TREE_CODE (exp);
2259 tree type = TREE_TYPE (exp);
2261 switch (TREE_CODE_CLASS (code))
2263 case tcc_declaration:
2268 if (code == CALL_EXPR)
2271 int i, n = call_expr_nargs (exp);
2274 argarray = (tree *) alloca (n * sizeof (tree));
2275 for (i = 0; i < n; i++)
2276 argarray[i] = max_size (CALL_EXPR_ARG (exp, i), max_p);
2277 return build_call_array (type, CALL_EXPR_FN (exp), n, argarray);
2282 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
2283 modify. Otherwise, we treat it like a variable. */
2284 if (!CONTAINS_PLACEHOLDER_P (exp))
2287 type = TREE_TYPE (TREE_OPERAND (exp, 1));
2289 max_size (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type), true);
2291 case tcc_comparison:
2292 return max_p ? size_one_node : size_zero_node;
2296 case tcc_expression:
2297 switch (TREE_CODE_LENGTH (code))
2300 if (code == NON_LVALUE_EXPR)
2301 return max_size (TREE_OPERAND (exp, 0), max_p);
2304 fold_build1 (code, type,
2305 max_size (TREE_OPERAND (exp, 0),
2306 code == NEGATE_EXPR ? !max_p : max_p));
2309 if (code == COMPOUND_EXPR)
2310 return max_size (TREE_OPERAND (exp, 1), max_p);
2312 /* Calculate "(A ? B : C) - D" as "A ? B - D : C - D" which
2313 may provide a tighter bound on max_size. */
2314 if (code == MINUS_EXPR
2315 && TREE_CODE (TREE_OPERAND (exp, 0)) == COND_EXPR)
2317 tree lhs = fold_build2 (MINUS_EXPR, type,
2318 TREE_OPERAND (TREE_OPERAND (exp, 0), 1),
2319 TREE_OPERAND (exp, 1));
2320 tree rhs = fold_build2 (MINUS_EXPR, type,
2321 TREE_OPERAND (TREE_OPERAND (exp, 0), 2),
2322 TREE_OPERAND (exp, 1));
2323 return fold_build2 (max_p ? MAX_EXPR : MIN_EXPR, type,
2324 max_size (lhs, max_p),
2325 max_size (rhs, max_p));
2329 tree lhs = max_size (TREE_OPERAND (exp, 0), max_p);
2330 tree rhs = max_size (TREE_OPERAND (exp, 1),
2331 code == MINUS_EXPR ? !max_p : max_p);
2333 /* Special-case wanting the maximum value of a MIN_EXPR.
2334 In that case, if one side overflows, return the other.
2335 sizetype is signed, but we know sizes are non-negative.
2336 Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
2337 overflowing or the maximum possible value and the RHS
2341 && TREE_CODE (rhs) == INTEGER_CST
2342 && TREE_OVERFLOW (rhs))
2346 && TREE_CODE (lhs) == INTEGER_CST
2347 && TREE_OVERFLOW (lhs))
2349 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
2350 && ((TREE_CODE (lhs) == INTEGER_CST
2351 && TREE_OVERFLOW (lhs))
2352 || operand_equal_p (lhs, TYPE_MAX_VALUE (type), 0))
2353 && !TREE_CONSTANT (rhs))
2356 return fold_build2 (code, type, lhs, rhs);
2360 if (code == SAVE_EXPR)
2362 else if (code == COND_EXPR)
2363 return fold_build2 (max_p ? MAX_EXPR : MIN_EXPR, type,
2364 max_size (TREE_OPERAND (exp, 1), max_p),
2365 max_size (TREE_OPERAND (exp, 2), max_p));
2368 /* Other tree classes cannot happen. */
2376 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
2377 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
2378 Return a constructor for the template. */
2381 build_template (tree template_type, tree array_type, tree expr)
2383 tree template_elts = NULL_TREE;
2384 tree bound_list = NULL_TREE;
2387 while (TREE_CODE (array_type) == RECORD_TYPE
2388 && (TYPE_IS_PADDING_P (array_type)
2389 || TYPE_JUSTIFIED_MODULAR_P (array_type)))
2390 array_type = TREE_TYPE (TYPE_FIELDS (array_type));
2392 if (TREE_CODE (array_type) == ARRAY_TYPE
2393 || (TREE_CODE (array_type) == INTEGER_TYPE
2394 && TYPE_HAS_ACTUAL_BOUNDS_P (array_type)))
2395 bound_list = TYPE_ACTUAL_BOUNDS (array_type);
2397 /* First make the list for a CONSTRUCTOR for the template. Go down the
2398 field list of the template instead of the type chain because this
2399 array might be an Ada array of arrays and we can't tell where the
2400 nested arrays stop being the underlying object. */
2402 for (field = TYPE_FIELDS (template_type); field;
2404 ? (bound_list = TREE_CHAIN (bound_list))
2405 : (array_type = TREE_TYPE (array_type))),
2406 field = TREE_CHAIN (TREE_CHAIN (field)))
2408 tree bounds, min, max;
2410 /* If we have a bound list, get the bounds from there. Likewise
2411 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
2412 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
2413 This will give us a maximum range. */
2415 bounds = TREE_VALUE (bound_list);
2416 else if (TREE_CODE (array_type) == ARRAY_TYPE)
2417 bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type));
2418 else if (expr && TREE_CODE (expr) == PARM_DECL
2419 && DECL_BY_COMPONENT_PTR_P (expr))
2420 bounds = TREE_TYPE (field);
2424 min = convert (TREE_TYPE (field), TYPE_MIN_VALUE (bounds));
2425 max = convert (TREE_TYPE (TREE_CHAIN (field)), TYPE_MAX_VALUE (bounds));
2427 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
2428 substitute it from OBJECT. */
2429 min = SUBSTITUTE_PLACEHOLDER_IN_EXPR (min, expr);
2430 max = SUBSTITUTE_PLACEHOLDER_IN_EXPR (max, expr);
2432 template_elts = tree_cons (TREE_CHAIN (field), max,
2433 tree_cons (field, min, template_elts));
2436 return gnat_build_constructor (template_type, nreverse (template_elts));
2439 /* Build a 32bit VMS descriptor from a Mechanism_Type, which must specify
2440 a descriptor type, and the GCC type of an object. Each FIELD_DECL
2441 in the type contains in its DECL_INITIAL the expression to use when
2442 a constructor is made for the type. GNAT_ENTITY is an entity used
2443 to print out an error message if the mechanism cannot be applied to
2444 an object of that type and also for the name. */
2447 build_vms_descriptor32 (tree type, Mechanism_Type mech, Entity_Id gnat_entity)
2449 tree record_type = make_node (RECORD_TYPE);
2450 tree pointer32_type;
2451 tree field_list = 0;
2460 /* If TYPE is an unconstrained array, use the underlying array type. */
2461 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
2462 type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type))));
2464 /* If this is an array, compute the number of dimensions in the array,
2465 get the index types, and point to the inner type. */
2466 if (TREE_CODE (type) != ARRAY_TYPE)
2469 for (ndim = 1, inner_type = type;
2470 TREE_CODE (TREE_TYPE (inner_type)) == ARRAY_TYPE
2471 && TYPE_MULTI_ARRAY_P (TREE_TYPE (inner_type));
2472 ndim++, inner_type = TREE_TYPE (inner_type))
2475 idx_arr = (tree *) alloca (ndim * sizeof (tree));
2477 if (mech != By_Descriptor_NCA && mech != By_Short_Descriptor_NCA
2478 && TREE_CODE (type) == ARRAY_TYPE && TYPE_CONVENTION_FORTRAN_P (type))
2479 for (i = ndim - 1, inner_type = type;
2481 i--, inner_type = TREE_TYPE (inner_type))
2482 idx_arr[i] = TYPE_DOMAIN (inner_type);
2484 for (i = 0, inner_type = type;
2486 i++, inner_type = TREE_TYPE (inner_type))
2487 idx_arr[i] = TYPE_DOMAIN (inner_type);
2489 /* Now get the DTYPE value. */
2490 switch (TREE_CODE (type))
2495 if (TYPE_VAX_FLOATING_POINT_P (type))
2496 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2509 switch (GET_MODE_BITSIZE (TYPE_MODE (type)))
2512 dtype = TYPE_UNSIGNED (type) ? 2 : 6;
2515 dtype = TYPE_UNSIGNED (type) ? 3 : 7;
2518 dtype = TYPE_UNSIGNED (type) ? 4 : 8;
2521 dtype = TYPE_UNSIGNED (type) ? 5 : 9;
2524 dtype = TYPE_UNSIGNED (type) ? 25 : 26;
2530 dtype = GET_MODE_BITSIZE (TYPE_MODE (type)) == 32 ? 52 : 53;
2534 if (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE
2535 && TYPE_VAX_FLOATING_POINT_P (type))
2536 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2548 dtype = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) == 32 ? 54: 55;
2559 /* Get the CLASS value. */
2562 case By_Descriptor_A:
2563 case By_Short_Descriptor_A:
2566 case By_Descriptor_NCA:
2567 case By_Short_Descriptor_NCA:
2570 case By_Descriptor_SB:
2571 case By_Short_Descriptor_SB:
2575 case By_Short_Descriptor:
2576 case By_Descriptor_S:
2577 case By_Short_Descriptor_S:
2583 /* Make the type for a descriptor for VMS. The first four fields
2584 are the same for all types. */
2587 = chainon (field_list,
2588 make_descriptor_field
2589 ("LENGTH", gnat_type_for_size (16, 1), record_type,
2590 size_in_bytes ((mech == By_Descriptor_A ||
2591 mech == By_Short_Descriptor_A)
2592 ? inner_type : type)));
2594 field_list = chainon (field_list,
2595 make_descriptor_field ("DTYPE",
2596 gnat_type_for_size (8, 1),
2597 record_type, size_int (dtype)));
2598 field_list = chainon (field_list,
2599 make_descriptor_field ("CLASS",
2600 gnat_type_for_size (8, 1),
2601 record_type, size_int (class)));
2603 /* Of course this will crash at run-time if the address space is not
2604 within the low 32 bits, but there is nothing else we can do. */
2605 pointer32_type = build_pointer_type_for_mode (type, SImode, false);
2608 = chainon (field_list,
2609 make_descriptor_field
2610 ("POINTER", pointer32_type, record_type,
2611 build_unary_op (ADDR_EXPR,
2613 build0 (PLACEHOLDER_EXPR, type))));
2618 case By_Short_Descriptor:
2619 case By_Descriptor_S:
2620 case By_Short_Descriptor_S:
2623 case By_Descriptor_SB:
2624 case By_Short_Descriptor_SB:
2626 = chainon (field_list,
2627 make_descriptor_field
2628 ("SB_L1", gnat_type_for_size (32, 1), record_type,
2629 TREE_CODE (type) == ARRAY_TYPE
2630 ? TYPE_MIN_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2632 = chainon (field_list,
2633 make_descriptor_field
2634 ("SB_U1", gnat_type_for_size (32, 1), record_type,
2635 TREE_CODE (type) == ARRAY_TYPE
2636 ? TYPE_MAX_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2639 case By_Descriptor_A:
2640 case By_Short_Descriptor_A:
2641 case By_Descriptor_NCA:
2642 case By_Short_Descriptor_NCA:
2643 field_list = chainon (field_list,
2644 make_descriptor_field ("SCALE",
2645 gnat_type_for_size (8, 1),
2649 field_list = chainon (field_list,
2650 make_descriptor_field ("DIGITS",
2651 gnat_type_for_size (8, 1),
2656 = chainon (field_list,
2657 make_descriptor_field
2658 ("AFLAGS", gnat_type_for_size (8, 1), record_type,
2659 size_int ((mech == By_Descriptor_NCA ||
2660 mech == By_Short_Descriptor_NCA)
2662 /* Set FL_COLUMN, FL_COEFF, and FL_BOUNDS. */
2663 : (TREE_CODE (type) == ARRAY_TYPE
2664 && TYPE_CONVENTION_FORTRAN_P (type)
2667 field_list = chainon (field_list,
2668 make_descriptor_field ("DIMCT",
2669 gnat_type_for_size (8, 1),
2673 field_list = chainon (field_list,
2674 make_descriptor_field ("ARSIZE",
2675 gnat_type_for_size (32, 1),
2677 size_in_bytes (type)));
2679 /* Now build a pointer to the 0,0,0... element. */
2680 tem = build0 (PLACEHOLDER_EXPR, type);
2681 for (i = 0, inner_type = type; i < ndim;
2682 i++, inner_type = TREE_TYPE (inner_type))
2683 tem = build4 (ARRAY_REF, TREE_TYPE (inner_type), tem,
2684 convert (TYPE_DOMAIN (inner_type), size_zero_node),
2685 NULL_TREE, NULL_TREE);
2688 = chainon (field_list,
2689 make_descriptor_field
2691 build_pointer_type_for_mode (inner_type, SImode, false),
2694 build_pointer_type_for_mode (inner_type, SImode,
2698 /* Next come the addressing coefficients. */
2699 tem = size_one_node;
2700 for (i = 0; i < ndim; i++)
2704 = size_binop (MULT_EXPR, tem,
2705 size_binop (PLUS_EXPR,
2706 size_binop (MINUS_EXPR,
2707 TYPE_MAX_VALUE (idx_arr[i]),
2708 TYPE_MIN_VALUE (idx_arr[i])),
2711 fname[0] = ((mech == By_Descriptor_NCA ||
2712 mech == By_Short_Descriptor_NCA) ? 'S' : 'M');
2713 fname[1] = '0' + i, fname[2] = 0;
2715 = chainon (field_list,
2716 make_descriptor_field (fname,
2717 gnat_type_for_size (32, 1),
2718 record_type, idx_length));
2720 if (mech == By_Descriptor_NCA || mech == By_Short_Descriptor_NCA)
2724 /* Finally here are the bounds. */
2725 for (i = 0; i < ndim; i++)
2729 fname[0] = 'L', fname[1] = '0' + i, fname[2] = 0;
2731 = chainon (field_list,
2732 make_descriptor_field
2733 (fname, gnat_type_for_size (32, 1), record_type,
2734 TYPE_MIN_VALUE (idx_arr[i])));
2738 = chainon (field_list,
2739 make_descriptor_field
2740 (fname, gnat_type_for_size (32, 1), record_type,
2741 TYPE_MAX_VALUE (idx_arr[i])));
2746 post_error ("unsupported descriptor type for &", gnat_entity);
2749 TYPE_NAME (record_type) = create_concat_name (gnat_entity, "DESC");
2750 finish_record_type (record_type, field_list, 0, true);
2754 /* Build a 64bit VMS descriptor from a Mechanism_Type, which must specify
2755 a descriptor type, and the GCC type of an object. Each FIELD_DECL
2756 in the type contains in its DECL_INITIAL the expression to use when
2757 a constructor is made for the type. GNAT_ENTITY is an entity used
2758 to print out an error message if the mechanism cannot be applied to
2759 an object of that type and also for the name. */
2762 build_vms_descriptor (tree type, Mechanism_Type mech, Entity_Id gnat_entity)
2764 tree record64_type = make_node (RECORD_TYPE);
2765 tree pointer64_type;
2766 tree field_list64 = 0;
2775 /* If TYPE is an unconstrained array, use the underlying array type. */
2776 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
2777 type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type))));
2779 /* If this is an array, compute the number of dimensions in the array,
2780 get the index types, and point to the inner type. */
2781 if (TREE_CODE (type) != ARRAY_TYPE)
2784 for (ndim = 1, inner_type = type;
2785 TREE_CODE (TREE_TYPE (inner_type)) == ARRAY_TYPE
2786 && TYPE_MULTI_ARRAY_P (TREE_TYPE (inner_type));
2787 ndim++, inner_type = TREE_TYPE (inner_type))
2790 idx_arr = (tree *) alloca (ndim * sizeof (tree));
2792 if (mech != By_Descriptor_NCA
2793 && TREE_CODE (type) == ARRAY_TYPE && TYPE_CONVENTION_FORTRAN_P (type))
2794 for (i = ndim - 1, inner_type = type;
2796 i--, inner_type = TREE_TYPE (inner_type))
2797 idx_arr[i] = TYPE_DOMAIN (inner_type);
2799 for (i = 0, inner_type = type;
2801 i++, inner_type = TREE_TYPE (inner_type))
2802 idx_arr[i] = TYPE_DOMAIN (inner_type);
2804 /* Now get the DTYPE value. */
2805 switch (TREE_CODE (type))
2810 if (TYPE_VAX_FLOATING_POINT_P (type))
2811 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2824 switch (GET_MODE_BITSIZE (TYPE_MODE (type)))
2827 dtype = TYPE_UNSIGNED (type) ? 2 : 6;
2830 dtype = TYPE_UNSIGNED (type) ? 3 : 7;
2833 dtype = TYPE_UNSIGNED (type) ? 4 : 8;
2836 dtype = TYPE_UNSIGNED (type) ? 5 : 9;
2839 dtype = TYPE_UNSIGNED (type) ? 25 : 26;
2845 dtype = GET_MODE_BITSIZE (TYPE_MODE (type)) == 32 ? 52 : 53;
2849 if (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE
2850 && TYPE_VAX_FLOATING_POINT_P (type))
2851 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2863 dtype = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) == 32 ? 54: 55;
2874 /* Get the CLASS value. */
2877 case By_Descriptor_A:
2880 case By_Descriptor_NCA:
2883 case By_Descriptor_SB:
2887 case By_Descriptor_S:
2893 /* Make the type for a 64bit descriptor for VMS. The first six fields
2894 are the same for all types. */
2896 field_list64 = chainon (field_list64,
2897 make_descriptor_field ("MBO",
2898 gnat_type_for_size (16, 1),
2899 record64_type, size_int (1)));
2901 field_list64 = chainon (field_list64,
2902 make_descriptor_field ("DTYPE",
2903 gnat_type_for_size (8, 1),
2904 record64_type, size_int (dtype)));
2905 field_list64 = chainon (field_list64,
2906 make_descriptor_field ("CLASS",
2907 gnat_type_for_size (8, 1),
2908 record64_type, size_int (class)));
2910 field_list64 = chainon (field_list64,
2911 make_descriptor_field ("MBMO",
2912 gnat_type_for_size (32, 1),
2913 record64_type, ssize_int (-1)));
2916 = chainon (field_list64,
2917 make_descriptor_field
2918 ("LENGTH", gnat_type_for_size (64, 1), record64_type,
2919 size_in_bytes (mech == By_Descriptor_A ? inner_type : type)));
2921 pointer64_type = build_pointer_type_for_mode (type, DImode, false);
2924 = chainon (field_list64,
2925 make_descriptor_field
2926 ("POINTER", pointer64_type, record64_type,
2927 build_unary_op (ADDR_EXPR,
2929 build0 (PLACEHOLDER_EXPR, type))));
2934 case By_Descriptor_S:
2937 case By_Descriptor_SB:
2939 = chainon (field_list64,
2940 make_descriptor_field
2941 ("SB_L1", gnat_type_for_size (64, 1), record64_type,
2942 TREE_CODE (type) == ARRAY_TYPE
2943 ? TYPE_MIN_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2945 = chainon (field_list64,
2946 make_descriptor_field
2947 ("SB_U1", gnat_type_for_size (64, 1), record64_type,
2948 TREE_CODE (type) == ARRAY_TYPE
2949 ? TYPE_MAX_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2952 case By_Descriptor_A:
2953 case By_Descriptor_NCA:
2954 field_list64 = chainon (field_list64,
2955 make_descriptor_field ("SCALE",
2956 gnat_type_for_size (8, 1),
2960 field_list64 = chainon (field_list64,
2961 make_descriptor_field ("DIGITS",
2962 gnat_type_for_size (8, 1),
2967 = chainon (field_list64,
2968 make_descriptor_field
2969 ("AFLAGS", gnat_type_for_size (8, 1), record64_type,
2970 size_int (mech == By_Descriptor_NCA
2972 /* Set FL_COLUMN, FL_COEFF, and FL_BOUNDS. */
2973 : (TREE_CODE (type) == ARRAY_TYPE
2974 && TYPE_CONVENTION_FORTRAN_P (type)
2977 field_list64 = chainon (field_list64,
2978 make_descriptor_field ("DIMCT",
2979 gnat_type_for_size (8, 1),
2983 field_list64 = chainon (field_list64,
2984 make_descriptor_field ("MBZ",
2985 gnat_type_for_size (32, 1),
2988 field_list64 = chainon (field_list64,
2989 make_descriptor_field ("ARSIZE",
2990 gnat_type_for_size (64, 1),
2992 size_in_bytes (type)));
2994 /* Now build a pointer to the 0,0,0... element. */
2995 tem = build0 (PLACEHOLDER_EXPR, type);
2996 for (i = 0, inner_type = type; i < ndim;
2997 i++, inner_type = TREE_TYPE (inner_type))
2998 tem = build4 (ARRAY_REF, TREE_TYPE (inner_type), tem,
2999 convert (TYPE_DOMAIN (inner_type), size_zero_node),
3000 NULL_TREE, NULL_TREE);
3003 = chainon (field_list64,
3004 make_descriptor_field
3006 build_pointer_type_for_mode (inner_type, DImode, false),
3009 build_pointer_type_for_mode (inner_type, DImode,
3013 /* Next come the addressing coefficients. */
3014 tem = size_one_node;
3015 for (i = 0; i < ndim; i++)
3019 = size_binop (MULT_EXPR, tem,
3020 size_binop (PLUS_EXPR,
3021 size_binop (MINUS_EXPR,
3022 TYPE_MAX_VALUE (idx_arr[i]),
3023 TYPE_MIN_VALUE (idx_arr[i])),
3026 fname[0] = (mech == By_Descriptor_NCA ? 'S' : 'M');
3027 fname[1] = '0' + i, fname[2] = 0;
3029 = chainon (field_list64,
3030 make_descriptor_field (fname,
3031 gnat_type_for_size (64, 1),
3032 record64_type, idx_length));
3034 if (mech == By_Descriptor_NCA)
3038 /* Finally here are the bounds. */
3039 for (i = 0; i < ndim; i++)
3043 fname[0] = 'L', fname[1] = '0' + i, fname[2] = 0;
3045 = chainon (field_list64,
3046 make_descriptor_field
3047 (fname, gnat_type_for_size (64, 1), record64_type,
3048 TYPE_MIN_VALUE (idx_arr[i])));
3052 = chainon (field_list64,
3053 make_descriptor_field
3054 (fname, gnat_type_for_size (64, 1), record64_type,
3055 TYPE_MAX_VALUE (idx_arr[i])));
3060 post_error ("unsupported descriptor type for &", gnat_entity);
3063 TYPE_NAME (record64_type) = create_concat_name (gnat_entity, "DESC64");
3064 finish_record_type (record64_type, field_list64, 0, true);
3065 return record64_type;
3068 /* Utility routine for above code to make a field. */
3071 make_descriptor_field (const char *name, tree type,
3072 tree rec_type, tree initial)
3075 = create_field_decl (get_identifier (name), type, rec_type, 0, 0, 0, 0);
3077 DECL_INITIAL (field) = initial;
3081 /* Convert GNU_EXPR, a pointer to a 64bit VMS descriptor, to GNU_TYPE, a
3082 regular pointer or fat pointer type. GNAT_SUBPROG is the subprogram to
3083 which the VMS descriptor is passed. */
3086 convert_vms_descriptor64 (tree gnu_type, tree gnu_expr, Entity_Id gnat_subprog)
3088 tree desc_type = TREE_TYPE (TREE_TYPE (gnu_expr));
3089 tree desc = build1 (INDIRECT_REF, desc_type, gnu_expr);
3090 /* The CLASS field is the 3rd field in the descriptor. */
3091 tree class = TREE_CHAIN (TREE_CHAIN (TYPE_FIELDS (desc_type)));
3092 /* The POINTER field is the 6th field in the descriptor. */
3093 tree pointer64 = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (class)));
3095 /* Retrieve the value of the POINTER field. */
3097 = build3 (COMPONENT_REF, TREE_TYPE (pointer64), desc, pointer64, NULL_TREE);
3099 if (POINTER_TYPE_P (gnu_type))
3100 return convert (gnu_type, gnu_expr64);
3102 else if (TYPE_FAT_POINTER_P (gnu_type))
3104 tree p_array_type = TREE_TYPE (TYPE_FIELDS (gnu_type));
3105 tree p_bounds_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_type)));
3106 tree template_type = TREE_TYPE (p_bounds_type);
3107 tree min_field = TYPE_FIELDS (template_type);
3108 tree max_field = TREE_CHAIN (TYPE_FIELDS (template_type));
3109 tree template, template_addr, aflags, dimct, t, u;
3110 /* See the head comment of build_vms_descriptor. */
3111 int iclass = TREE_INT_CST_LOW (DECL_INITIAL (class));
3112 tree lfield, ufield;
3114 /* Convert POINTER to the type of the P_ARRAY field. */
3115 gnu_expr64 = convert (p_array_type, gnu_expr64);
3119 case 1: /* Class S */
3120 case 15: /* Class SB */
3121 /* Build {1, LENGTH} template; LENGTH64 is the 5th field. */
3122 t = TREE_CHAIN (TREE_CHAIN (class));
3123 t = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3124 t = tree_cons (min_field,
3125 convert (TREE_TYPE (min_field), integer_one_node),
3126 tree_cons (max_field,
3127 convert (TREE_TYPE (max_field), t),
3129 template = gnat_build_constructor (template_type, t);
3130 template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template);
3132 /* For class S, we are done. */
3136 /* Test that we really have a SB descriptor, like DEC Ada. */
3137 t = build3 (COMPONENT_REF, TREE_TYPE (class), desc, class, NULL);
3138 u = convert (TREE_TYPE (class), DECL_INITIAL (class));
3139 u = build_binary_op (EQ_EXPR, integer_type_node, t, u);
3140 /* If so, there is already a template in the descriptor and
3141 it is located right after the POINTER field. The fields are
3142 64bits so they must be repacked. */
3143 t = TREE_CHAIN (pointer64);
3144 lfield = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3145 lfield = convert (TREE_TYPE (TYPE_FIELDS (template_type)), lfield);
3148 ufield = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3150 (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (template_type))), ufield);
3152 /* Build the template in the form of a constructor. */
3153 t = tree_cons (TYPE_FIELDS (template_type), lfield,
3154 tree_cons (TREE_CHAIN (TYPE_FIELDS (template_type)),
3155 ufield, NULL_TREE));
3156 template = gnat_build_constructor (template_type, t);
3158 /* Otherwise use the {1, LENGTH} template we build above. */
3159 template_addr = build3 (COND_EXPR, p_bounds_type, u,
3160 build_unary_op (ADDR_EXPR, p_bounds_type,
3165 case 4: /* Class A */
3166 /* The AFLAGS field is the 3rd field after the pointer in the
3168 t = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (pointer64)));
3169 aflags = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3170 /* The DIMCT field is the next field in the descriptor after
3173 dimct = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3174 /* Raise CONSTRAINT_ERROR if either more than 1 dimension
3175 or FL_COEFF or FL_BOUNDS not set. */
3176 u = build_int_cst (TREE_TYPE (aflags), 192);
3177 u = build_binary_op (TRUTH_OR_EXPR, integer_type_node,
3178 build_binary_op (NE_EXPR, integer_type_node,
3180 convert (TREE_TYPE (dimct),
3182 build_binary_op (NE_EXPR, integer_type_node,
3183 build2 (BIT_AND_EXPR,
3187 /* There is already a template in the descriptor and it is located
3188 in block 3. The fields are 64bits so they must be repacked. */
3189 t = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (TREE_CHAIN
3191 lfield = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3192 lfield = convert (TREE_TYPE (TYPE_FIELDS (template_type)), lfield);
3195 ufield = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3197 (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (template_type))), ufield);
3199 /* Build the template in the form of a constructor. */
3200 t = tree_cons (TYPE_FIELDS (template_type), lfield,
3201 tree_cons (TREE_CHAIN (TYPE_FIELDS (template_type)),
3202 ufield, NULL_TREE));
3203 template = gnat_build_constructor (template_type, t);
3204 template = build3 (COND_EXPR, p_bounds_type, u,
3205 build_call_raise (CE_Length_Check_Failed, Empty,
3206 N_Raise_Constraint_Error),
3208 template_addr = build_unary_op (ADDR_EXPR, p_bounds_type, template);
3211 case 10: /* Class NCA */
3213 post_error ("unsupported descriptor type for &", gnat_subprog);
3214 template_addr = integer_zero_node;
3218 /* Build the fat pointer in the form of a constructor. */
3219 t = tree_cons (TYPE_FIELDS (gnu_type), gnu_expr64,
3220 tree_cons (TREE_CHAIN (TYPE_FIELDS (gnu_type)),
3221 template_addr, NULL_TREE));
3222 return gnat_build_constructor (gnu_type, t);
3229 /* Convert GNU_EXPR, a pointer to a 32bit VMS descriptor, to GNU_TYPE, a
3230 regular pointer or fat pointer type. GNAT_SUBPROG is the subprogram to
3231 which the VMS descriptor is passed. */
3234 convert_vms_descriptor32 (tree gnu_type, tree gnu_expr, Entity_Id gnat_subprog)
3236 tree desc_type = TREE_TYPE (TREE_TYPE (gnu_expr));
3237 tree desc = build1 (INDIRECT_REF, desc_type, gnu_expr);
3238 /* The CLASS field is the 3rd field in the descriptor. */
3239 tree class = TREE_CHAIN (TREE_CHAIN (TYPE_FIELDS (desc_type)));
3240 /* The POINTER field is the 4th field in the descriptor. */
3241 tree pointer = TREE_CHAIN (class);
3243 /* Retrieve the value of the POINTER field. */
3245 = build3 (COMPONENT_REF, TREE_TYPE (pointer), desc, pointer, NULL_TREE);
3247 if (POINTER_TYPE_P (gnu_type))
3248 return convert (gnu_type, gnu_expr32);
3250 else if (TYPE_FAT_POINTER_P (gnu_type))
3252 tree p_array_type = TREE_TYPE (TYPE_FIELDS (gnu_type));
3253 tree p_bounds_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_type)));
3254 tree template_type = TREE_TYPE (p_bounds_type);
3255 tree min_field = TYPE_FIELDS (template_type);
3256 tree max_field = TREE_CHAIN (TYPE_FIELDS (template_type));
3257 tree template, template_addr, aflags, dimct, t, u;
3258 /* See the head comment of build_vms_descriptor. */
3259 int iclass = TREE_INT_CST_LOW (DECL_INITIAL (class));
3261 /* Convert POINTER to the type of the P_ARRAY field. */
3262 gnu_expr32 = convert (p_array_type, gnu_expr32);
3266 case 1: /* Class S */
3267 case 15: /* Class SB */
3268 /* Build {1, LENGTH} template; LENGTH is the 1st field. */
3269 t = TYPE_FIELDS (desc_type);
3270 t = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3271 t = tree_cons (min_field,
3272 convert (TREE_TYPE (min_field), integer_one_node),
3273 tree_cons (max_field,
3274 convert (TREE_TYPE (max_field), t),
3276 template = gnat_build_constructor (template_type, t);
3277 template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template);
3279 /* For class S, we are done. */
3283 /* Test that we really have a SB descriptor, like DEC Ada. */
3284 t = build3 (COMPONENT_REF, TREE_TYPE (class), desc, class, NULL);
3285 u = convert (TREE_TYPE (class), DECL_INITIAL (class));
3286 u = build_binary_op (EQ_EXPR, integer_type_node, t, u);
3287 /* If so, there is already a template in the descriptor and
3288 it is located right after the POINTER field. */
3289 t = TREE_CHAIN (pointer);
3290 template = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3291 /* Otherwise use the {1, LENGTH} template we build above. */
3292 template_addr = build3 (COND_EXPR, p_bounds_type, u,
3293 build_unary_op (ADDR_EXPR, p_bounds_type,
3298 case 4: /* Class A */
3299 /* The AFLAGS field is the 7th field in the descriptor. */
3300 t = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (pointer)));
3301 aflags = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3302 /* The DIMCT field is the 8th field in the descriptor. */
3304 dimct = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3305 /* Raise CONSTRAINT_ERROR if either more than 1 dimension
3306 or FL_COEFF or FL_BOUNDS not set. */
3307 u = build_int_cst (TREE_TYPE (aflags), 192);
3308 u = build_binary_op (TRUTH_OR_EXPR, integer_type_node,
3309 build_binary_op (NE_EXPR, integer_type_node,
3311 convert (TREE_TYPE (dimct),
3313 build_binary_op (NE_EXPR, integer_type_node,
3314 build2 (BIT_AND_EXPR,
3318 /* There is already a template in the descriptor and it is
3319 located at the start of block 3 (12th field). */
3320 t = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (t))));
3321 template = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE);
3322 template = build3 (COND_EXPR, p_bounds_type, u,
3323 build_call_raise (CE_Length_Check_Failed, Empty,
3324 N_Raise_Constraint_Error),
3326 template_addr = build_unary_op (ADDR_EXPR, p_bounds_type, template);
3329 case 10: /* Class NCA */
3331 post_error ("unsupported descriptor type for &", gnat_subprog);
3332 template_addr = integer_zero_node;
3336 /* Build the fat pointer in the form of a constructor. */
3337 t = tree_cons (TYPE_FIELDS (gnu_type), gnu_expr32,
3338 tree_cons (TREE_CHAIN (TYPE_FIELDS (gnu_type)),
3339 template_addr, NULL_TREE));
3341 return gnat_build_constructor (gnu_type, t);
3348 /* Convert GNU_EXPR, a pointer to a VMS descriptor, to GNU_TYPE, a regular
3349 pointer or fat pointer type. GNU_EXPR_ALT_TYPE is the alternate (32-bit)
3350 pointer type of GNU_EXPR. GNAT_SUBPROG is the subprogram to which the
3351 VMS descriptor is passed. */
3354 convert_vms_descriptor (tree gnu_type, tree gnu_expr, tree gnu_expr_alt_type,
3355 Entity_Id gnat_subprog)
3357 tree desc_type = TREE_TYPE (TREE_TYPE (gnu_expr));
3358 tree desc = build1 (INDIRECT_REF, desc_type, gnu_expr);
3359 tree mbo = TYPE_FIELDS (desc_type);
3360 const char *mbostr = IDENTIFIER_POINTER (DECL_NAME (mbo));
3361 tree mbmo = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (mbo)));
3362 tree is64bit, gnu_expr32, gnu_expr64;
3364 /* If the field name is not MBO, it must be 32-bit and no alternate.
3365 Otherwise primary must be 64-bit and alternate 32-bit. */
3366 if (strcmp (mbostr, "MBO") != 0)
3367 return convert_vms_descriptor32 (gnu_type, gnu_expr, gnat_subprog);
3369 /* Build the test for 64-bit descriptor. */
3370 mbo = build3 (COMPONENT_REF, TREE_TYPE (mbo), desc, mbo, NULL_TREE);
3371 mbmo = build3 (COMPONENT_REF, TREE_TYPE (mbmo), desc, mbmo, NULL_TREE);
3373 = build_binary_op (TRUTH_ANDIF_EXPR, integer_type_node,
3374 build_binary_op (EQ_EXPR, integer_type_node,
3375 convert (integer_type_node, mbo),
3377 build_binary_op (EQ_EXPR, integer_type_node,
3378 convert (integer_type_node, mbmo),
3379 integer_minus_one_node));
3381 /* Build the 2 possible end results. */
3382 gnu_expr64 = convert_vms_descriptor64 (gnu_type, gnu_expr, gnat_subprog);
3383 gnu_expr = fold_convert (gnu_expr_alt_type, gnu_expr);
3384 gnu_expr32 = convert_vms_descriptor32 (gnu_type, gnu_expr, gnat_subprog);
3386 return build3 (COND_EXPR, gnu_type, is64bit, gnu_expr64, gnu_expr32);
3389 /* Build a stub for the subprogram specified by the GCC tree GNU_SUBPROG
3390 and the GNAT node GNAT_SUBPROG. */
3393 build_function_stub (tree gnu_subprog, Entity_Id gnat_subprog)
3395 tree gnu_subprog_type, gnu_subprog_addr, gnu_subprog_call;
3396 tree gnu_stub_param, gnu_param_list, gnu_arg_types, gnu_param;
3397 tree gnu_stub_decl = DECL_FUNCTION_STUB (gnu_subprog);
3400 gnu_subprog_type = TREE_TYPE (gnu_subprog);
3401 gnu_param_list = NULL_TREE;
3403 begin_subprog_body (gnu_stub_decl);
3406 start_stmt_group ();
3408 /* Loop over the parameters of the stub and translate any of them
3409 passed by descriptor into a by reference one. */
3410 for (gnu_stub_param = DECL_ARGUMENTS (gnu_stub_decl),
3411 gnu_arg_types = TYPE_ARG_TYPES (gnu_subprog_type);
3413 gnu_stub_param = TREE_CHAIN (gnu_stub_param),
3414 gnu_arg_types = TREE_CHAIN (gnu_arg_types))
3416 if (DECL_BY_DESCRIPTOR_P (gnu_stub_param))
3418 = convert_vms_descriptor (TREE_VALUE (gnu_arg_types),
3420 DECL_PARM_ALT_TYPE (gnu_stub_param),
3423 gnu_param = gnu_stub_param;
3425 gnu_param_list = tree_cons (NULL_TREE, gnu_param, gnu_param_list);
3428 gnu_body = end_stmt_group ();
3430 /* Invoke the internal subprogram. */
3431 gnu_subprog_addr = build1 (ADDR_EXPR, build_pointer_type (gnu_subprog_type),
3433 gnu_subprog_call = build_call_list (TREE_TYPE (gnu_subprog_type),
3435 nreverse (gnu_param_list));
3437 /* Propagate the return value, if any. */
3438 if (VOID_TYPE_P (TREE_TYPE (gnu_subprog_type)))
3439 append_to_statement_list (gnu_subprog_call, &gnu_body);
3441 append_to_statement_list (build_return_expr (DECL_RESULT (gnu_stub_decl),
3447 allocate_struct_function (gnu_stub_decl, false);
3448 end_subprog_body (gnu_body, false);
3451 /* Build a type to be used to represent an aliased object whose nominal
3452 type is an unconstrained array. This consists of a RECORD_TYPE containing
3453 a field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an
3454 ARRAY_TYPE. If ARRAY_TYPE is that of the unconstrained array, this
3455 is used to represent an arbitrary unconstrained object. Use NAME
3456 as the name of the record. */
3459 build_unc_object_type (tree template_type, tree object_type, tree name)
3461 tree type = make_node (RECORD_TYPE);
3462 tree template_field = create_field_decl (get_identifier ("BOUNDS"),
3463 template_type, type, 0, 0, 0, 1);
3464 tree array_field = create_field_decl (get_identifier ("ARRAY"), object_type,
3467 TYPE_NAME (type) = name;
3468 TYPE_CONTAINS_TEMPLATE_P (type) = 1;
3469 finish_record_type (type,
3470 chainon (chainon (NULL_TREE, template_field),
3477 /* Same, taking a thin or fat pointer type instead of a template type. */
3480 build_unc_object_type_from_ptr (tree thin_fat_ptr_type, tree object_type,
3485 gcc_assert (TYPE_FAT_OR_THIN_POINTER_P (thin_fat_ptr_type));
3488 = (TYPE_FAT_POINTER_P (thin_fat_ptr_type)
3489 ? TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (thin_fat_ptr_type))))
3490 : TREE_TYPE (TYPE_FIELDS (TREE_TYPE (thin_fat_ptr_type))));
3491 return build_unc_object_type (template_type, object_type, name);
3494 /* Shift the component offsets within an unconstrained object TYPE to make it
3495 suitable for use as a designated type for thin pointers. */
3498 shift_unc_components_for_thin_pointers (tree type)
3500 /* Thin pointer values designate the ARRAY data of an unconstrained object,
3501 allocated past the BOUNDS template. The designated type is adjusted to
3502 have ARRAY at position zero and the template at a negative offset, so
3503 that COMPONENT_REFs on (*thin_ptr) designate the proper location. */
3505 tree bounds_field = TYPE_FIELDS (type);
3506 tree array_field = TREE_CHAIN (TYPE_FIELDS (type));
3508 DECL_FIELD_OFFSET (bounds_field)
3509 = size_binop (MINUS_EXPR, size_zero_node, byte_position (array_field));
3511 DECL_FIELD_OFFSET (array_field) = size_zero_node;
3512 DECL_FIELD_BIT_OFFSET (array_field) = bitsize_zero_node;
3515 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE.
3516 In the normal case this is just two adjustments, but we have more to
3517 do if NEW_TYPE is an UNCONSTRAINED_ARRAY_TYPE. */
3520 update_pointer_to (tree old_type, tree new_type)
3522 tree ptr = TYPE_POINTER_TO (old_type);
3523 tree ref = TYPE_REFERENCE_TO (old_type);
3527 /* If this is the main variant, process all the other variants first. */
3528 if (TYPE_MAIN_VARIANT (old_type) == old_type)
3529 for (type = TYPE_NEXT_VARIANT (old_type); type;
3530 type = TYPE_NEXT_VARIANT (type))
3531 update_pointer_to (type, new_type);
3533 /* If no pointers and no references, we are done. */
3537 /* Merge the old type qualifiers in the new type.
3539 Each old variant has qualifiers for specific reasons, and the new
3540 designated type as well. Each set of qualifiers represents useful
3541 information grabbed at some point, and merging the two simply unifies
3542 these inputs into the final type description.
3544 Consider for instance a volatile type frozen after an access to constant
3545 type designating it; after the designated type's freeze, we get here with
3546 a volatile NEW_TYPE and a dummy OLD_TYPE with a readonly variant, created
3547 when the access type was processed. We will make a volatile and readonly
3548 designated type, because that's what it really is.
3550 We might also get here for a non-dummy OLD_TYPE variant with different
3551 qualifiers than those of NEW_TYPE, for instance in some cases of pointers
3552 to private record type elaboration (see the comments around the call to
3553 this routine in gnat_to_gnu_entity <E_Access_Type>). We have to merge
3554 the qualifiers in those cases too, to avoid accidentally discarding the
3555 initial set, and will often end up with OLD_TYPE == NEW_TYPE then. */
3557 = build_qualified_type (new_type,
3558 TYPE_QUALS (old_type) | TYPE_QUALS (new_type));
3560 /* If old type and new type are identical, there is nothing to do. */
3561 if (old_type == new_type)
3564 /* Otherwise, first handle the simple case. */
3565 if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE)
3567 TYPE_POINTER_TO (new_type) = ptr;
3568 TYPE_REFERENCE_TO (new_type) = ref;
3570 for (; ptr; ptr = TYPE_NEXT_PTR_TO (ptr))
3571 for (ptr1 = TYPE_MAIN_VARIANT (ptr); ptr1;
3572 ptr1 = TYPE_NEXT_VARIANT (ptr1))
3573 TREE_TYPE (ptr1) = new_type;
3575 for (; ref; ref = TYPE_NEXT_REF_TO (ref))
3576 for (ref1 = TYPE_MAIN_VARIANT (ref); ref1;
3577 ref1 = TYPE_NEXT_VARIANT (ref1))
3578 TREE_TYPE (ref1) = new_type;
3581 /* Now deal with the unconstrained array case. In this case the "pointer"
3582 is actually a RECORD_TYPE where both fields are pointers to dummy nodes.
3583 Turn them into pointers to the correct types using update_pointer_to. */
3584 else if (!TYPE_FAT_POINTER_P (ptr))
3589 tree new_obj_rec = TYPE_OBJECT_RECORD_TYPE (new_type);
3590 tree array_field = TYPE_FIELDS (ptr);
3591 tree bounds_field = TREE_CHAIN (TYPE_FIELDS (ptr));
3592 tree new_ptr = TYPE_POINTER_TO (new_type);
3596 /* Make pointers to the dummy template point to the real template. */
3598 (TREE_TYPE (TREE_TYPE (bounds_field)),
3599 TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_ptr)))));
3601 /* The references to the template bounds present in the array type
3602 are made through a PLACEHOLDER_EXPR of type NEW_PTR. Since we
3603 are updating PTR to make it a full replacement for NEW_PTR as
3604 pointer to NEW_TYPE, we must rework the PLACEHOLDER_EXPR so as
3605 to make it of type PTR. */
3606 new_ref = build3 (COMPONENT_REF, TREE_TYPE (bounds_field),
3607 build0 (PLACEHOLDER_EXPR, ptr),
3608 bounds_field, NULL_TREE);
3610 /* Create the new array for the new PLACEHOLDER_EXPR and make pointers
3611 to the dummy array point to it.
3613 ??? This is now the only use of substitute_in_type, which is a very
3614 "heavy" routine to do this, it should be replaced at some point. */
3616 (TREE_TYPE (TREE_TYPE (array_field)),
3617 substitute_in_type (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (new_ptr))),
3618 TREE_CHAIN (TYPE_FIELDS (new_ptr)), new_ref));
3620 /* Make PTR the pointer to NEW_TYPE. */
3621 TYPE_POINTER_TO (new_type) = TYPE_REFERENCE_TO (new_type)
3622 = TREE_TYPE (new_type) = ptr;
3624 for (var = TYPE_MAIN_VARIANT (ptr); var; var = TYPE_NEXT_VARIANT (var))
3625 SET_TYPE_UNCONSTRAINED_ARRAY (var, new_type);
3627 /* Now handle updating the allocation record, what the thin pointer
3628 points to. Update all pointers from the old record into the new
3629 one, update the type of the array field, and recompute the size. */
3630 update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), new_obj_rec);
3632 TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
3633 = TREE_TYPE (TREE_TYPE (array_field));
3635 /* The size recomputation needs to account for alignment constraints, so
3636 we let layout_type work it out. This will reset the field offsets to
3637 what they would be in a regular record, so we shift them back to what
3638 we want them to be for a thin pointer designated type afterwards. */
3639 DECL_SIZE (TYPE_FIELDS (new_obj_rec)) = 0;
3640 DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))) = 0;
3641 TYPE_SIZE (new_obj_rec) = 0;
3642 layout_type (new_obj_rec);
3644 shift_unc_components_for_thin_pointers (new_obj_rec);
3646 /* We are done, at last. */
3647 rest_of_record_type_compilation (ptr);
3651 /* Convert EXPR, a pointer to a constrained array, into a pointer to an
3652 unconstrained one. This involves making or finding a template. */
3655 convert_to_fat_pointer (tree type, tree expr)
3657 tree template_type = TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type))));
3658 tree p_array_type = TREE_TYPE (TYPE_FIELDS (type));
3659 tree etype = TREE_TYPE (expr);
3662 /* If EXPR is null, make a fat pointer that contains null pointers to the
3663 template and array. */
3664 if (integer_zerop (expr))
3666 gnat_build_constructor
3668 tree_cons (TYPE_FIELDS (type),
3669 convert (p_array_type, expr),
3670 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
3671 convert (build_pointer_type (template_type),
3675 /* If EXPR is a thin pointer, make template and data from the record.. */
3676 else if (TYPE_THIN_POINTER_P (etype))
3678 tree fields = TYPE_FIELDS (TREE_TYPE (etype));
3680 expr = save_expr (expr);
3681 if (TREE_CODE (expr) == ADDR_EXPR)
3682 expr = TREE_OPERAND (expr, 0);
3684 expr = build1 (INDIRECT_REF, TREE_TYPE (etype), expr);
3686 template = build_component_ref (expr, NULL_TREE, fields, false);
3687 expr = build_unary_op (ADDR_EXPR, NULL_TREE,
3688 build_component_ref (expr, NULL_TREE,
3689 TREE_CHAIN (fields), false));
3692 /* Otherwise, build the constructor for the template. */
3694 template = build_template (template_type, TREE_TYPE (etype), expr);
3696 /* The final result is a constructor for the fat pointer.
3698 If EXPR is an argument of a foreign convention subprogram, the type it
3699 points to is directly the component type. In this case, the expression
3700 type may not match the corresponding FIELD_DECL type at this point, so we
3701 call "convert" here to fix that up if necessary. This type consistency is
3702 required, for instance because it ensures that possible later folding of
3703 COMPONENT_REFs against this constructor always yields something of the
3704 same type as the initial reference.
3706 Note that the call to "build_template" above is still fine because it
3707 will only refer to the provided TEMPLATE_TYPE in this case. */
3709 gnat_build_constructor
3711 tree_cons (TYPE_FIELDS (type),
3712 convert (p_array_type, expr),
3713 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
3714 build_unary_op (ADDR_EXPR, NULL_TREE, template),
3718 /* Convert to a thin pointer type, TYPE. The only thing we know how to convert
3719 is something that is a fat pointer, so convert to it first if it EXPR
3720 is not already a fat pointer. */
3723 convert_to_thin_pointer (tree type, tree expr)
3725 if (!TYPE_FAT_POINTER_P (TREE_TYPE (expr)))
3727 = convert_to_fat_pointer
3728 (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))), expr);
3730 /* We get the pointer to the data and use a NOP_EXPR to make it the
3732 expr = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (TREE_TYPE (expr)),
3734 expr = build1 (NOP_EXPR, type, expr);
3739 /* Create an expression whose value is that of EXPR,
3740 converted to type TYPE. The TREE_TYPE of the value
3741 is always TYPE. This function implements all reasonable
3742 conversions; callers should filter out those that are
3743 not permitted by the language being compiled. */
3746 convert (tree type, tree expr)
3748 enum tree_code code = TREE_CODE (type);
3749 tree etype = TREE_TYPE (expr);
3750 enum tree_code ecode = TREE_CODE (etype);
3752 /* If EXPR is already the right type, we are done. */
3756 /* If both input and output have padding and are of variable size, do this
3757 as an unchecked conversion. Likewise if one is a mere variant of the
3758 other, so we avoid a pointless unpad/repad sequence. */
3759 else if (code == RECORD_TYPE && ecode == RECORD_TYPE
3760 && TYPE_IS_PADDING_P (type) && TYPE_IS_PADDING_P (etype)
3761 && (!TREE_CONSTANT (TYPE_SIZE (type))
3762 || !TREE_CONSTANT (TYPE_SIZE (etype))
3763 || gnat_types_compatible_p (type, etype)
3764 || TYPE_NAME (TREE_TYPE (TYPE_FIELDS (type)))
3765 == TYPE_NAME (TREE_TYPE (TYPE_FIELDS (etype)))))
3768 /* If the output type has padding, convert to the inner type and
3769 make a constructor to build the record. */
3770 else if (code == RECORD_TYPE && TYPE_IS_PADDING_P (type))
3772 /* If we previously converted from another type and our type is
3773 of variable size, remove the conversion to avoid the need for
3774 variable-size temporaries. Likewise for a conversion between
3775 original and packable version. */
3776 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
3777 && (!TREE_CONSTANT (TYPE_SIZE (type))
3778 || (ecode == RECORD_TYPE
3779 && TYPE_NAME (etype)
3780 == TYPE_NAME (TREE_TYPE (TREE_OPERAND (expr, 0))))))
3781 expr = TREE_OPERAND (expr, 0);
3783 /* If we are just removing the padding from expr, convert the original
3784 object if we have variable size in order to avoid the need for some
3785 variable-size temporaries. Likewise if the padding is a mere variant
3786 of the other, so we avoid a pointless unpad/repad sequence. */
3787 if (TREE_CODE (expr) == COMPONENT_REF
3788 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE
3789 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (expr, 0)))
3790 && (!TREE_CONSTANT (TYPE_SIZE (type))
3791 || gnat_types_compatible_p (type,
3792 TREE_TYPE (TREE_OPERAND (expr, 0)))
3793 || (ecode == RECORD_TYPE
3794 && TYPE_NAME (etype)
3795 == TYPE_NAME (TREE_TYPE (TYPE_FIELDS (type))))))
3796 return convert (type, TREE_OPERAND (expr, 0));
3798 /* If the result type is a padded type with a self-referentially-sized
3799 field and the expression type is a record, do this as an
3800 unchecked conversion. */
3801 else if (TREE_CODE (etype) == RECORD_TYPE
3802 && CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type))))
3803 return unchecked_convert (type, expr, false);
3807 gnat_build_constructor (type,
3808 tree_cons (TYPE_FIELDS (type),
3810 (TYPE_FIELDS (type)),
3815 /* If the input type has padding, remove it and convert to the output type.
3816 The conditions ordering is arranged to ensure that the output type is not
3817 a padding type here, as it is not clear whether the conversion would
3818 always be correct if this was to happen. */
3819 else if (ecode == RECORD_TYPE && TYPE_IS_PADDING_P (etype))
3823 /* If we have just converted to this padded type, just get the
3824 inner expression. */
3825 if (TREE_CODE (expr) == CONSTRUCTOR
3826 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (expr))
3827 && VEC_index (constructor_elt, CONSTRUCTOR_ELTS (expr), 0)->index
3828 == TYPE_FIELDS (etype))
3830 = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (expr), 0)->value;
3832 /* Otherwise, build an explicit component reference. */
3835 = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (etype), false);
3837 return convert (type, unpadded);
3840 /* If the input is a biased type, adjust first. */
3841 if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype))
3842 return convert (type, fold_build2 (PLUS_EXPR, TREE_TYPE (etype),
3843 fold_convert (TREE_TYPE (etype),
3845 TYPE_MIN_VALUE (etype)));
3847 /* If the input is a justified modular type, we need to extract the actual
3848 object before converting it to any other type with the exceptions of an
3849 unconstrained array or of a mere type variant. It is useful to avoid the
3850 extraction and conversion in the type variant case because it could end
3851 up replacing a VAR_DECL expr by a constructor and we might be about the
3852 take the address of the result. */
3853 if (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)
3854 && code != UNCONSTRAINED_ARRAY_TYPE
3855 && TYPE_MAIN_VARIANT (type) != TYPE_MAIN_VARIANT (etype))
3856 return convert (type, build_component_ref (expr, NULL_TREE,
3857 TYPE_FIELDS (etype), false));
3859 /* If converting to a type that contains a template, convert to the data
3860 type and then build the template. */
3861 if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type))
3863 tree obj_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type)));
3865 /* If the source already has a template, get a reference to the
3866 associated array only, as we are going to rebuild a template
3867 for the target type anyway. */
3868 expr = maybe_unconstrained_array (expr);
3871 gnat_build_constructor
3873 tree_cons (TYPE_FIELDS (type),
3874 build_template (TREE_TYPE (TYPE_FIELDS (type)),
3875 obj_type, NULL_TREE),
3876 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
3877 convert (obj_type, expr), NULL_TREE)));
3880 /* There are some special cases of expressions that we process
3882 switch (TREE_CODE (expr))
3888 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
3889 conversion in gnat_expand_expr. NULL_EXPR does not represent
3890 and actual value, so no conversion is needed. */
3891 expr = copy_node (expr);
3892 TREE_TYPE (expr) = type;
3896 /* If we are converting a STRING_CST to another constrained array type,
3897 just make a new one in the proper type. */
3898 if (code == ecode && AGGREGATE_TYPE_P (etype)
3899 && !(TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST
3900 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
3902 expr = copy_node (expr);
3903 TREE_TYPE (expr) = type;
3909 /* If we are converting a CONSTRUCTOR to a mere variant type, just make
3910 a new one in the proper type. */
3911 if (code == ecode && gnat_types_compatible_p (type, etype))
3913 expr = copy_node (expr);
3914 TREE_TYPE (expr) = type;
3918 /* Likewise for a conversion between original and packable version, but
3919 we have to work harder in order to preserve type consistency. */
3921 && code == RECORD_TYPE
3922 && TYPE_NAME (type) == TYPE_NAME (etype))
3924 VEC(constructor_elt,gc) *e = CONSTRUCTOR_ELTS (expr);
3925 unsigned HOST_WIDE_INT len = VEC_length (constructor_elt, e);
3926 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, len);
3927 tree efield = TYPE_FIELDS (etype), field = TYPE_FIELDS (type);
3928 unsigned HOST_WIDE_INT idx;
3931 FOR_EACH_CONSTRUCTOR_ELT(e, idx, index, value)
3933 constructor_elt *elt = VEC_quick_push (constructor_elt, v, NULL);
3934 /* We expect only simple constructors. Otherwise, punt. */
3935 if (!(index == efield || index == DECL_ORIGINAL_FIELD (efield)))
3938 elt->value = convert (TREE_TYPE (field), value);
3939 efield = TREE_CHAIN (efield);
3940 field = TREE_CHAIN (field);
3945 expr = copy_node (expr);
3946 TREE_TYPE (expr) = type;
3947 CONSTRUCTOR_ELTS (expr) = v;
3953 case UNCONSTRAINED_ARRAY_REF:
3954 /* Convert this to the type of the inner array by getting the address of
3955 the array from the template. */
3956 expr = build_unary_op (INDIRECT_REF, NULL_TREE,
3957 build_component_ref (TREE_OPERAND (expr, 0),
3958 get_identifier ("P_ARRAY"),
3960 etype = TREE_TYPE (expr);
3961 ecode = TREE_CODE (etype);
3964 case VIEW_CONVERT_EXPR:
3966 /* GCC 4.x is very sensitive to type consistency overall, and view
3967 conversions thus are very frequent. Even though just "convert"ing
3968 the inner operand to the output type is fine in most cases, it
3969 might expose unexpected input/output type mismatches in special
3970 circumstances so we avoid such recursive calls when we can. */
3971 tree op0 = TREE_OPERAND (expr, 0);
3973 /* If we are converting back to the original type, we can just
3974 lift the input conversion. This is a common occurrence with
3975 switches back-and-forth amongst type variants. */
3976 if (type == TREE_TYPE (op0))
3979 /* Otherwise, if we're converting between two aggregate types, we
3980 might be allowed to substitute the VIEW_CONVERT_EXPR target type
3981 in place or to just convert the inner expression. */
3982 if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype))
3984 /* If we are converting between mere variants, we can just
3985 substitute the VIEW_CONVERT_EXPR in place. */
3986 if (gnat_types_compatible_p (type, etype))
3987 return build1 (VIEW_CONVERT_EXPR, type, op0);
3989 /* Otherwise, we may just bypass the input view conversion unless
3990 one of the types is a fat pointer, which is handled by
3991 specialized code below which relies on exact type matching. */
3992 else if (!TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
3993 return convert (type, op0);
3999 /* If both types are record types, just convert the pointer and
4000 make a new INDIRECT_REF.
4002 ??? Disable this for now since it causes problems with the
4003 code in build_binary_op for MODIFY_EXPR which wants to
4004 strip off conversions. But that code really is a mess and
4005 we need to do this a much better way some time. */
4007 && (TREE_CODE (type) == RECORD_TYPE
4008 || TREE_CODE (type) == UNION_TYPE)
4009 && (TREE_CODE (etype) == RECORD_TYPE
4010 || TREE_CODE (etype) == UNION_TYPE)
4011 && !TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
4012 return build_unary_op (INDIRECT_REF, NULL_TREE,
4013 convert (build_pointer_type (type),
4014 TREE_OPERAND (expr, 0)));
4021 /* Check for converting to a pointer to an unconstrained array. */
4022 if (TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
4023 return convert_to_fat_pointer (type, expr);
4025 /* If we are converting between two aggregate types that are mere
4026 variants, just make a VIEW_CONVERT_EXPR. */
4027 else if (code == ecode
4028 && AGGREGATE_TYPE_P (type)
4029 && gnat_types_compatible_p (type, etype))
4030 return build1 (VIEW_CONVERT_EXPR, type, expr);
4032 /* In all other cases of related types, make a NOP_EXPR. */
4033 else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype)
4034 || (code == INTEGER_CST && ecode == INTEGER_CST
4035 && (type == TREE_TYPE (etype) || etype == TREE_TYPE (type))))
4036 return fold_convert (type, expr);
4041 return fold_build1 (CONVERT_EXPR, type, expr);
4044 if (TYPE_HAS_ACTUAL_BOUNDS_P (type)
4045 && (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE
4046 || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))))
4047 return unchecked_convert (type, expr, false);
4048 else if (TYPE_BIASED_REPRESENTATION_P (type))
4049 return fold_convert (type,
4050 fold_build2 (MINUS_EXPR, TREE_TYPE (type),
4051 convert (TREE_TYPE (type), expr),
4052 TYPE_MIN_VALUE (type)));
4054 /* ... fall through ... */
4058 /* If we are converting an additive expression to an integer type
4059 with lower precision, be wary of the optimization that can be
4060 applied by convert_to_integer. There are 2 problematic cases:
4061 - if the first operand was originally of a biased type,
4062 because we could be recursively called to convert it
4063 to an intermediate type and thus rematerialize the
4064 additive operator endlessly,
4065 - if the expression contains a placeholder, because an
4066 intermediate conversion that changes the sign could
4067 be inserted and thus introduce an artificial overflow
4068 at compile time when the placeholder is substituted. */
4069 if (code == INTEGER_TYPE
4070 && ecode == INTEGER_TYPE
4071 && TYPE_PRECISION (type) < TYPE_PRECISION (etype)
4072 && (TREE_CODE (expr) == PLUS_EXPR || TREE_CODE (expr) == MINUS_EXPR))
4074 tree op0 = get_unwidened (TREE_OPERAND (expr, 0), type);
4076 if ((TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4077 && TYPE_BIASED_REPRESENTATION_P (TREE_TYPE (op0)))
4078 || CONTAINS_PLACEHOLDER_P (expr))
4079 return build1 (NOP_EXPR, type, expr);
4082 return fold (convert_to_integer (type, expr));
4085 case REFERENCE_TYPE:
4086 /* If converting between two pointers to records denoting
4087 both a template and type, adjust if needed to account
4088 for any differing offsets, since one might be negative. */
4089 if (TYPE_THIN_POINTER_P (etype) && TYPE_THIN_POINTER_P (type))
4092 = size_diffop (bit_position (TYPE_FIELDS (TREE_TYPE (etype))),
4093 bit_position (TYPE_FIELDS (TREE_TYPE (type))));
4094 tree byte_diff = size_binop (CEIL_DIV_EXPR, bit_diff,
4095 sbitsize_int (BITS_PER_UNIT));
4097 expr = build1 (NOP_EXPR, type, expr);
4098 TREE_CONSTANT (expr) = TREE_CONSTANT (TREE_OPERAND (expr, 0));
4099 if (integer_zerop (byte_diff))
4102 return build_binary_op (POINTER_PLUS_EXPR, type, expr,
4103 fold (convert (sizetype, byte_diff)));
4106 /* If converting to a thin pointer, handle specially. */
4107 if (TYPE_THIN_POINTER_P (type)
4108 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
4109 return convert_to_thin_pointer (type, expr);
4111 /* If converting fat pointer to normal pointer, get the pointer to the
4112 array and then convert it. */
4113 else if (TYPE_FAT_POINTER_P (etype))
4114 expr = build_component_ref (expr, get_identifier ("P_ARRAY"),
4117 return fold (convert_to_pointer (type, expr));
4120 return fold (convert_to_real (type, expr));
4123 if (TYPE_JUSTIFIED_MODULAR_P (type) && !AGGREGATE_TYPE_P (etype))
4125 gnat_build_constructor
4126 (type, tree_cons (TYPE_FIELDS (type),
4127 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
4130 /* ... fall through ... */
4133 /* In these cases, assume the front-end has validated the conversion.
4134 If the conversion is valid, it will be a bit-wise conversion, so
4135 it can be viewed as an unchecked conversion. */
4136 return unchecked_convert (type, expr, false);
4139 /* This is a either a conversion between a tagged type and some
4140 subtype, which we have to mark as a UNION_TYPE because of
4141 overlapping fields or a conversion of an Unchecked_Union. */
4142 return unchecked_convert (type, expr, false);
4144 case UNCONSTRAINED_ARRAY_TYPE:
4145 /* If EXPR is a constrained array, take its address, convert it to a
4146 fat pointer, and then dereference it. Likewise if EXPR is a
4147 record containing both a template and a constrained array.
4148 Note that a record representing a justified modular type
4149 always represents a packed constrained array. */
4150 if (ecode == ARRAY_TYPE
4151 || (ecode == INTEGER_TYPE && TYPE_HAS_ACTUAL_BOUNDS_P (etype))
4152 || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))
4153 || (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)))
4156 (INDIRECT_REF, NULL_TREE,
4157 convert_to_fat_pointer (TREE_TYPE (type),
4158 build_unary_op (ADDR_EXPR,
4161 /* Do something very similar for converting one unconstrained
4162 array to another. */
4163 else if (ecode == UNCONSTRAINED_ARRAY_TYPE)
4165 build_unary_op (INDIRECT_REF, NULL_TREE,
4166 convert (TREE_TYPE (type),
4167 build_unary_op (ADDR_EXPR,
4173 return fold (convert_to_complex (type, expr));
4180 /* Remove all conversions that are done in EXP. This includes converting
4181 from a padded type or to a justified modular type. If TRUE_ADDRESS
4182 is true, always return the address of the containing object even if
4183 the address is not bit-aligned. */
4186 remove_conversions (tree exp, bool true_address)
4188 switch (TREE_CODE (exp))
4192 && TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
4193 && TYPE_JUSTIFIED_MODULAR_P (TREE_TYPE (exp)))
4195 remove_conversions (VEC_index (constructor_elt,
4196 CONSTRUCTOR_ELTS (exp), 0)->value,
4201 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == RECORD_TYPE
4202 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
4203 return remove_conversions (TREE_OPERAND (exp, 0), true_address);
4206 case VIEW_CONVERT_EXPR: case NON_LVALUE_EXPR:
4208 return remove_conversions (TREE_OPERAND (exp, 0), true_address);
4217 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
4218 refers to the underlying array. If its type has TYPE_CONTAINS_TEMPLATE_P,
4219 likewise return an expression pointing to the underlying array. */
4222 maybe_unconstrained_array (tree exp)
4224 enum tree_code code = TREE_CODE (exp);
4227 switch (TREE_CODE (TREE_TYPE (exp)))
4229 case UNCONSTRAINED_ARRAY_TYPE:
4230 if (code == UNCONSTRAINED_ARRAY_REF)
4233 = build_unary_op (INDIRECT_REF, NULL_TREE,
4234 build_component_ref (TREE_OPERAND (exp, 0),
4235 get_identifier ("P_ARRAY"),
4237 TREE_READONLY (new) = TREE_STATIC (new) = TREE_READONLY (exp);
4241 else if (code == NULL_EXPR)
4242 return build1 (NULL_EXPR,
4243 TREE_TYPE (TREE_TYPE (TYPE_FIELDS
4244 (TREE_TYPE (TREE_TYPE (exp))))),
4245 TREE_OPERAND (exp, 0));
4248 /* If this is a padded type, convert to the unpadded type and see if
4249 it contains a template. */
4250 if (TYPE_IS_PADDING_P (TREE_TYPE (exp)))
4252 new = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (exp))), exp);
4253 if (TREE_CODE (TREE_TYPE (new)) == RECORD_TYPE
4254 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (new)))
4256 build_component_ref (new, NULL_TREE,
4257 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new))),
4260 else if (TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (exp)))
4262 build_component_ref (exp, NULL_TREE,
4263 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (exp))), 0);
4273 /* Return true if EXPR is an expression that can be folded as an operand
4274 of a VIEW_CONVERT_EXPR. See the head comment of unchecked_convert for
4278 can_fold_for_view_convert_p (tree expr)
4282 /* The folder will fold NOP_EXPRs between integral types with the same
4283 precision (in the middle-end's sense). We cannot allow it if the
4284 types don't have the same precision in the Ada sense as well. */
4285 if (TREE_CODE (expr) != NOP_EXPR)
4288 t1 = TREE_TYPE (expr);
4289 t2 = TREE_TYPE (TREE_OPERAND (expr, 0));
4291 /* Defer to the folder for non-integral conversions. */
4292 if (!(INTEGRAL_TYPE_P (t1) && INTEGRAL_TYPE_P (t2)))
4295 /* Only fold conversions that preserve both precisions. */
4296 if (TYPE_PRECISION (t1) == TYPE_PRECISION (t2)
4297 && operand_equal_p (rm_size (t1), rm_size (t2), 0))
4303 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
4304 If NOTRUNC_P is true, truncation operations should be suppressed.
4306 Special care is required with (source or target) integral types whose
4307 precision is not equal to their size, to make sure we fetch or assign
4308 the value bits whose location might depend on the endianness, e.g.
4310 Rmsize : constant := 8;
4311 subtype Int is Integer range 0 .. 2 ** Rmsize - 1;
4313 type Bit_Array is array (1 .. Rmsize) of Boolean;
4314 pragma Pack (Bit_Array);
4316 function To_Bit_Array is new Unchecked_Conversion (Int, Bit_Array);
4318 Value : Int := 2#1000_0001#;
4319 Vbits : Bit_Array := To_Bit_Array (Value);
4321 we expect the 8 bits at Vbits'Address to always contain Value, while
4322 their original location depends on the endianness, at Value'Address
4323 on a little-endian architecture but not on a big-endian one.
4325 ??? There is a problematic discrepancy between what is called precision
4326 here (and more generally throughout gigi) for integral types and what is
4327 called precision in the middle-end. In the former case it's the RM size
4328 as given by TYPE_RM_SIZE (or rm_size) whereas it's TYPE_PRECISION in the
4329 latter case, the hitch being that they are not equal when they matter,
4330 that is when the number of value bits is not equal to the type's size:
4331 TYPE_RM_SIZE does give the number of value bits but TYPE_PRECISION is set
4332 to the size. The sole exception are BOOLEAN_TYPEs for which both are 1.
4334 The consequence is that gigi must duplicate code bridging the gap between
4335 the type's size and its precision that exists for TYPE_PRECISION in the
4336 middle-end, because the latter knows nothing about TYPE_RM_SIZE, and be
4337 wary of transformations applied in the middle-end based on TYPE_PRECISION
4338 because this value doesn't reflect the actual precision for Ada. */
4341 unchecked_convert (tree type, tree expr, bool notrunc_p)
4343 tree etype = TREE_TYPE (expr);
4345 /* If the expression is already the right type, we are done. */
4349 /* If both types types are integral just do a normal conversion.
4350 Likewise for a conversion to an unconstrained array. */
4351 if ((((INTEGRAL_TYPE_P (type)
4352 && !(TREE_CODE (type) == INTEGER_TYPE
4353 && TYPE_VAX_FLOATING_POINT_P (type)))
4354 || (POINTER_TYPE_P (type) && ! TYPE_THIN_POINTER_P (type))
4355 || (TREE_CODE (type) == RECORD_TYPE
4356 && TYPE_JUSTIFIED_MODULAR_P (type)))
4357 && ((INTEGRAL_TYPE_P (etype)
4358 && !(TREE_CODE (etype) == INTEGER_TYPE
4359 && TYPE_VAX_FLOATING_POINT_P (etype)))
4360 || (POINTER_TYPE_P (etype) && !TYPE_THIN_POINTER_P (etype))
4361 || (TREE_CODE (etype) == RECORD_TYPE
4362 && TYPE_JUSTIFIED_MODULAR_P (etype))))
4363 || TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
4365 if (TREE_CODE (etype) == INTEGER_TYPE
4366 && TYPE_BIASED_REPRESENTATION_P (etype))
4368 tree ntype = copy_type (etype);
4369 TYPE_BIASED_REPRESENTATION_P (ntype) = 0;
4370 TYPE_MAIN_VARIANT (ntype) = ntype;
4371 expr = build1 (NOP_EXPR, ntype, expr);
4374 if (TREE_CODE (type) == INTEGER_TYPE
4375 && TYPE_BIASED_REPRESENTATION_P (type))
4377 tree rtype = copy_type (type);
4378 TYPE_BIASED_REPRESENTATION_P (rtype) = 0;
4379 TYPE_MAIN_VARIANT (rtype) = rtype;
4380 expr = convert (rtype, expr);
4381 expr = build1 (NOP_EXPR, type, expr);
4384 /* We have another special case: if we are unchecked converting either
4385 a subtype or a type with limited range into a base type, we need to
4386 ensure that VRP doesn't propagate range information because this
4387 conversion may be done precisely to validate that the object is
4388 within the range it is supposed to have. */
4389 else if (TREE_CODE (expr) != INTEGER_CST
4390 && TREE_CODE (type) == INTEGER_TYPE && !TREE_TYPE (type)
4391 && ((TREE_CODE (etype) == INTEGER_TYPE && TREE_TYPE (etype))
4392 || TREE_CODE (etype) == ENUMERAL_TYPE
4393 || TREE_CODE (etype) == BOOLEAN_TYPE))
4395 /* The optimization barrier is a VIEW_CONVERT_EXPR node; moreover,
4396 in order not to be deemed an useless type conversion, it must
4397 be from subtype to base type.
4399 Therefore we first do the bulk of the conversion to a subtype of
4400 the final type. And this conversion must itself not be deemed
4401 useless if the source type is not a subtype because, otherwise,
4402 the final VIEW_CONVERT_EXPR will be deemed so as well. That's
4403 why we toggle the unsigned flag in this conversion, which is
4404 harmless since the final conversion is only a reinterpretation
4407 ??? This may raise addressability and/or aliasing issues because
4408 VIEW_CONVERT_EXPR gets gimplified as an lvalue, thus causing the
4409 address of its operand to be taken if it is deemed addressable
4410 and not already in GIMPLE form. */
4412 = gnat_type_for_mode (TYPE_MODE (type), !TYPE_UNSIGNED (etype));
4413 rtype = copy_type (rtype);
4414 TYPE_MAIN_VARIANT (rtype) = rtype;
4415 TREE_TYPE (rtype) = type;
4416 expr = convert (rtype, expr);
4417 expr = build1 (VIEW_CONVERT_EXPR, type, expr);
4421 expr = convert (type, expr);
4424 /* If we are converting to an integral type whose precision is not equal
4425 to its size, first unchecked convert to a record that contains an
4426 object of the output type. Then extract the field. */
4427 else if (INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type)
4428 && 0 != compare_tree_int (TYPE_RM_SIZE (type),
4429 GET_MODE_BITSIZE (TYPE_MODE (type))))
4431 tree rec_type = make_node (RECORD_TYPE);
4432 tree field = create_field_decl (get_identifier ("OBJ"), type,
4433 rec_type, 1, 0, 0, 0);
4435 TYPE_FIELDS (rec_type) = field;
4436 layout_type (rec_type);
4438 expr = unchecked_convert (rec_type, expr, notrunc_p);
4439 expr = build_component_ref (expr, NULL_TREE, field, 0);
4442 /* Similarly if we are converting from an integral type whose precision
4443 is not equal to its size. */
4444 else if (INTEGRAL_TYPE_P (etype) && TYPE_RM_SIZE (etype)
4445 && 0 != compare_tree_int (TYPE_RM_SIZE (etype),
4446 GET_MODE_BITSIZE (TYPE_MODE (etype))))
4448 tree rec_type = make_node (RECORD_TYPE);
4450 = create_field_decl (get_identifier ("OBJ"), etype, rec_type,
4453 TYPE_FIELDS (rec_type) = field;
4454 layout_type (rec_type);
4456 expr = gnat_build_constructor (rec_type, build_tree_list (field, expr));
4457 expr = unchecked_convert (type, expr, notrunc_p);
4460 /* We have a special case when we are converting between two
4461 unconstrained array types. In that case, take the address,
4462 convert the fat pointer types, and dereference. */
4463 else if (TREE_CODE (etype) == UNCONSTRAINED_ARRAY_TYPE
4464 && TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
4465 expr = build_unary_op (INDIRECT_REF, NULL_TREE,
4466 build1 (VIEW_CONVERT_EXPR, TREE_TYPE (type),
4467 build_unary_op (ADDR_EXPR, NULL_TREE,
4471 expr = maybe_unconstrained_array (expr);
4472 etype = TREE_TYPE (expr);
4473 if (can_fold_for_view_convert_p (expr))
4474 expr = fold_build1 (VIEW_CONVERT_EXPR, type, expr);
4476 expr = build1 (VIEW_CONVERT_EXPR, type, expr);
4479 /* If the result is an integral type whose precision is not equal to its
4480 size, sign- or zero-extend the result. We need not do this if the input
4481 is an integral type of the same precision and signedness or if the output
4482 is a biased type or if both the input and output are unsigned. */
4484 && INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type)
4485 && !(TREE_CODE (type) == INTEGER_TYPE
4486 && TYPE_BIASED_REPRESENTATION_P (type))
4487 && 0 != compare_tree_int (TYPE_RM_SIZE (type),
4488 GET_MODE_BITSIZE (TYPE_MODE (type)))
4489 && !(INTEGRAL_TYPE_P (etype)
4490 && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (etype)
4491 && operand_equal_p (TYPE_RM_SIZE (type),
4492 (TYPE_RM_SIZE (etype) != 0
4493 ? TYPE_RM_SIZE (etype) : TYPE_SIZE (etype)),
4495 && !(TYPE_UNSIGNED (type) && TYPE_UNSIGNED (etype)))
4497 tree base_type = gnat_type_for_mode (TYPE_MODE (type),
4498 TYPE_UNSIGNED (type));
4500 = convert (base_type,
4501 size_binop (MINUS_EXPR,
4503 (GET_MODE_BITSIZE (TYPE_MODE (type))),
4504 TYPE_RM_SIZE (type)));
4507 build_binary_op (RSHIFT_EXPR, base_type,
4508 build_binary_op (LSHIFT_EXPR, base_type,
4509 convert (base_type, expr),
4514 /* An unchecked conversion should never raise Constraint_Error. The code
4515 below assumes that GCC's conversion routines overflow the same way that
4516 the underlying hardware does. This is probably true. In the rare case
4517 when it is false, we can rely on the fact that such conversions are
4518 erroneous anyway. */
4519 if (TREE_CODE (expr) == INTEGER_CST)
4520 TREE_OVERFLOW (expr) = 0;
4522 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
4523 show no longer constant. */
4524 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
4525 && !operand_equal_p (TYPE_SIZE_UNIT (type), TYPE_SIZE_UNIT (etype),
4527 TREE_CONSTANT (expr) = 0;
4532 /* Return the appropriate GCC tree code for the specified GNAT type,
4533 the latter being a record type as predicated by Is_Record_Type. */
4536 tree_code_for_record_type (Entity_Id gnat_type)
4538 Node_Id component_list
4539 = Component_List (Type_Definition
4541 (Implementation_Base_Type (gnat_type))));
4544 /* Make this a UNION_TYPE unless it's either not an Unchecked_Union or
4545 we have a non-discriminant field outside a variant. In either case,
4546 it's a RECORD_TYPE. */
4548 if (!Is_Unchecked_Union (gnat_type))
4551 for (component = First_Non_Pragma (Component_Items (component_list));
4552 Present (component);
4553 component = Next_Non_Pragma (component))
4554 if (Ekind (Defining_Entity (component)) == E_Component)
4560 /* Return true if GNU_TYPE is suitable as the type of a non-aliased
4561 component of an aggregate type. */
4564 type_for_nonaliased_component_p (tree gnu_type)
4566 /* If the type is passed by reference, we may have pointers to the
4567 component so it cannot be made non-aliased. */
4568 if (must_pass_by_ref (gnu_type) || default_pass_by_ref (gnu_type))
4571 /* We used to say that any component of aggregate type is aliased
4572 because the front-end may take 'Reference of it. The front-end
4573 has been enhanced in the meantime so as to use a renaming instead
4574 in most cases, but the back-end can probably take the address of
4575 such a component too so we go for the conservative stance.
4577 For instance, we might need the address of any array type, even
4578 if normally passed by copy, to construct a fat pointer if the
4579 component is used as an actual for an unconstrained formal.
4581 Likewise for record types: even if a specific record subtype is
4582 passed by copy, the parent type might be passed by ref (e.g. if
4583 it's of variable size) and we might take the address of a child
4584 component to pass to a parent formal. We have no way to check
4585 for such conditions here. */
4586 if (AGGREGATE_TYPE_P (gnu_type))
4592 /* Perform final processing on global variables. */
4595 gnat_write_global_declarations (void)
4597 /* Proceed to optimize and emit assembly.
4598 FIXME: shouldn't be the front end's responsibility to call this. */
4601 /* Emit debug info for all global declarations. */
4602 emit_debug_global_declarations (VEC_address (tree, global_decls),
4603 VEC_length (tree, global_decls));
4606 /* ************************************************************************
4607 * * GCC builtins support *
4608 * ************************************************************************ */
4610 /* The general scheme is fairly simple:
4612 For each builtin function/type to be declared, gnat_install_builtins calls
4613 internal facilities which eventually get to gnat_push_decl, which in turn
4614 tracks the so declared builtin function decls in the 'builtin_decls' global
4615 datastructure. When an Intrinsic subprogram declaration is processed, we
4616 search this global datastructure to retrieve the associated BUILT_IN DECL
4619 /* Search the chain of currently available builtin declarations for a node
4620 corresponding to function NAME (an IDENTIFIER_NODE). Return the first node
4621 found, if any, or NULL_TREE otherwise. */
4623 builtin_decl_for (tree name)
4628 for (i = 0; VEC_iterate(tree, builtin_decls, i, decl); i++)
4629 if (DECL_NAME (decl) == name)
4635 /* The code below eventually exposes gnat_install_builtins, which declares
4636 the builtin types and functions we might need, either internally or as
4637 user accessible facilities.
4639 ??? This is a first implementation shot, still in rough shape. It is
4640 heavily inspired from the "C" family implementation, with chunks copied
4641 verbatim from there.
4643 Two obvious TODO candidates are
4644 o Use a more efficient name/decl mapping scheme
4645 o Devise a middle-end infrastructure to avoid having to copy
4646 pieces between front-ends. */
4648 /* ----------------------------------------------------------------------- *
4649 * BUILTIN ELEMENTARY TYPES *
4650 * ----------------------------------------------------------------------- */
4652 /* Standard data types to be used in builtin argument declarations. */
4656 CTI_SIGNED_SIZE_TYPE, /* For format checking only. */
4658 CTI_CONST_STRING_TYPE,
4663 static tree c_global_trees[CTI_MAX];
4665 #define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE]
4666 #define string_type_node c_global_trees[CTI_STRING_TYPE]
4667 #define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE]
4669 /* ??? In addition some attribute handlers, we currently don't support a
4670 (small) number of builtin-types, which in turns inhibits support for a
4671 number of builtin functions. */
4672 #define wint_type_node void_type_node
4673 #define intmax_type_node void_type_node
4674 #define uintmax_type_node void_type_node
4676 /* Build the void_list_node (void_type_node having been created). */
4679 build_void_list_node (void)
4681 tree t = build_tree_list (NULL_TREE, void_type_node);
4685 /* Used to help initialize the builtin-types.def table. When a type of
4686 the correct size doesn't exist, use error_mark_node instead of NULL.
4687 The later results in segfaults even when a decl using the type doesn't
4691 builtin_type_for_size (int size, bool unsignedp)
4693 tree type = lang_hooks.types.type_for_size (size, unsignedp);
4694 return type ? type : error_mark_node;
4697 /* Build/push the elementary type decls that builtin functions/types
4701 install_builtin_elementary_types (void)
4703 signed_size_type_node = size_type_node;
4704 pid_type_node = integer_type_node;
4705 void_list_node = build_void_list_node ();
4707 string_type_node = build_pointer_type (char_type_node);
4708 const_string_type_node
4709 = build_pointer_type (build_qualified_type
4710 (char_type_node, TYPE_QUAL_CONST));
4713 /* ----------------------------------------------------------------------- *
4714 * BUILTIN FUNCTION TYPES *
4715 * ----------------------------------------------------------------------- */
4717 /* Now, builtin function types per se. */
4721 #define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME,
4722 #define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME,
4723 #define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME,
4724 #define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME,
4725 #define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4726 #define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4727 #define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME,
4728 #define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME,
4729 #define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME,
4730 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
4731 #define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME,
4732 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
4733 #define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME,
4734 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
4735 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
4737 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
4738 #include "builtin-types.def"
4739 #undef DEF_PRIMITIVE_TYPE
4740 #undef DEF_FUNCTION_TYPE_0
4741 #undef DEF_FUNCTION_TYPE_1
4742 #undef DEF_FUNCTION_TYPE_2
4743 #undef DEF_FUNCTION_TYPE_3
4744 #undef DEF_FUNCTION_TYPE_4
4745 #undef DEF_FUNCTION_TYPE_5
4746 #undef DEF_FUNCTION_TYPE_6
4747 #undef DEF_FUNCTION_TYPE_7
4748 #undef DEF_FUNCTION_TYPE_VAR_0
4749 #undef DEF_FUNCTION_TYPE_VAR_1
4750 #undef DEF_FUNCTION_TYPE_VAR_2
4751 #undef DEF_FUNCTION_TYPE_VAR_3
4752 #undef DEF_FUNCTION_TYPE_VAR_4
4753 #undef DEF_FUNCTION_TYPE_VAR_5
4754 #undef DEF_POINTER_TYPE
4758 typedef enum c_builtin_type builtin_type;
4760 /* A temporary array used in communication with def_fn_type. */
4761 static GTY(()) tree builtin_types[(int) BT_LAST + 1];
4763 /* A helper function for install_builtin_types. Build function type
4764 for DEF with return type RET and N arguments. If VAR is true, then the
4765 function should be variadic after those N arguments.
4767 Takes special care not to ICE if any of the types involved are
4768 error_mark_node, which indicates that said type is not in fact available
4769 (see builtin_type_for_size). In which case the function type as a whole
4770 should be error_mark_node. */
4773 def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...)
4775 tree args = NULL, t;
4780 for (i = 0; i < n; ++i)
4782 builtin_type a = va_arg (list, builtin_type);
4783 t = builtin_types[a];
4784 if (t == error_mark_node)
4786 args = tree_cons (NULL_TREE, t, args);
4790 args = nreverse (args);
4792 args = chainon (args, void_list_node);
4794 t = builtin_types[ret];
4795 if (t == error_mark_node)
4797 t = build_function_type (t, args);
4800 builtin_types[def] = t;
4803 /* Build the builtin function types and install them in the builtin_types
4804 array for later use in builtin function decls. */
4807 install_builtin_function_types (void)
4809 tree va_list_ref_type_node;
4810 tree va_list_arg_type_node;
4812 if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
4814 va_list_arg_type_node = va_list_ref_type_node =
4815 build_pointer_type (TREE_TYPE (va_list_type_node));
4819 va_list_arg_type_node = va_list_type_node;
4820 va_list_ref_type_node = build_reference_type (va_list_type_node);
4823 #define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \
4824 builtin_types[ENUM] = VALUE;
4825 #define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \
4826 def_fn_type (ENUM, RETURN, 0, 0);
4827 #define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \
4828 def_fn_type (ENUM, RETURN, 0, 1, ARG1);
4829 #define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \
4830 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2);
4831 #define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4832 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3);
4833 #define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4834 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4);
4835 #define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4836 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4837 #define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4839 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
4840 #define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
4842 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
4843 #define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \
4844 def_fn_type (ENUM, RETURN, 1, 0);
4845 #define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \
4846 def_fn_type (ENUM, RETURN, 1, 1, ARG1);
4847 #define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \
4848 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2);
4849 #define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \
4850 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3);
4851 #define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \
4852 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
4853 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
4854 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
4855 #define DEF_POINTER_TYPE(ENUM, TYPE) \
4856 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
4858 #include "builtin-types.def"
4860 #undef DEF_PRIMITIVE_TYPE
4861 #undef DEF_FUNCTION_TYPE_1
4862 #undef DEF_FUNCTION_TYPE_2
4863 #undef DEF_FUNCTION_TYPE_3
4864 #undef DEF_FUNCTION_TYPE_4
4865 #undef DEF_FUNCTION_TYPE_5
4866 #undef DEF_FUNCTION_TYPE_6
4867 #undef DEF_FUNCTION_TYPE_VAR_0
4868 #undef DEF_FUNCTION_TYPE_VAR_1
4869 #undef DEF_FUNCTION_TYPE_VAR_2
4870 #undef DEF_FUNCTION_TYPE_VAR_3
4871 #undef DEF_FUNCTION_TYPE_VAR_4
4872 #undef DEF_FUNCTION_TYPE_VAR_5
4873 #undef DEF_POINTER_TYPE
4874 builtin_types[(int) BT_LAST] = NULL_TREE;
4877 /* ----------------------------------------------------------------------- *
4878 * BUILTIN ATTRIBUTES *
4879 * ----------------------------------------------------------------------- */
4881 enum built_in_attribute
4883 #define DEF_ATTR_NULL_TREE(ENUM) ENUM,
4884 #define DEF_ATTR_INT(ENUM, VALUE) ENUM,
4885 #define DEF_ATTR_IDENT(ENUM, STRING) ENUM,
4886 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM,
4887 #include "builtin-attrs.def"
4888 #undef DEF_ATTR_NULL_TREE
4890 #undef DEF_ATTR_IDENT
4891 #undef DEF_ATTR_TREE_LIST
4895 static GTY(()) tree built_in_attributes[(int) ATTR_LAST];
4898 install_builtin_attributes (void)
4900 /* Fill in the built_in_attributes array. */
4901 #define DEF_ATTR_NULL_TREE(ENUM) \
4902 built_in_attributes[(int) ENUM] = NULL_TREE;
4903 #define DEF_ATTR_INT(ENUM, VALUE) \
4904 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE);
4905 #define DEF_ATTR_IDENT(ENUM, STRING) \
4906 built_in_attributes[(int) ENUM] = get_identifier (STRING);
4907 #define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \
4908 built_in_attributes[(int) ENUM] \
4909 = tree_cons (built_in_attributes[(int) PURPOSE], \
4910 built_in_attributes[(int) VALUE], \
4911 built_in_attributes[(int) CHAIN]);
4912 #include "builtin-attrs.def"
4913 #undef DEF_ATTR_NULL_TREE
4915 #undef DEF_ATTR_IDENT
4916 #undef DEF_ATTR_TREE_LIST
4919 /* Handle a "const" attribute; arguments as in
4920 struct attribute_spec.handler. */
4923 handle_const_attribute (tree *node, tree ARG_UNUSED (name),
4924 tree ARG_UNUSED (args), int ARG_UNUSED (flags),
4927 if (TREE_CODE (*node) == FUNCTION_DECL)
4928 TREE_READONLY (*node) = 1;
4930 *no_add_attrs = true;
4935 /* Handle a "nothrow" attribute; arguments as in
4936 struct attribute_spec.handler. */
4939 handle_nothrow_attribute (tree *node, tree ARG_UNUSED (name),
4940 tree ARG_UNUSED (args), int ARG_UNUSED (flags),
4943 if (TREE_CODE (*node) == FUNCTION_DECL)
4944 TREE_NOTHROW (*node) = 1;
4946 *no_add_attrs = true;
4951 /* Handle a "pure" attribute; arguments as in
4952 struct attribute_spec.handler. */
4955 handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args),
4956 int ARG_UNUSED (flags), bool *no_add_attrs)
4958 if (TREE_CODE (*node) == FUNCTION_DECL)
4959 DECL_PURE_P (*node) = 1;
4960 /* ??? TODO: Support types. */
4963 warning (OPT_Wattributes, "%qE attribute ignored", name);
4964 *no_add_attrs = true;
4970 /* Handle a "no vops" attribute; arguments as in
4971 struct attribute_spec.handler. */
4974 handle_novops_attribute (tree *node, tree ARG_UNUSED (name),
4975 tree ARG_UNUSED (args), int ARG_UNUSED (flags),
4976 bool *ARG_UNUSED (no_add_attrs))
4978 gcc_assert (TREE_CODE (*node) == FUNCTION_DECL);
4979 DECL_IS_NOVOPS (*node) = 1;
4983 /* Helper for nonnull attribute handling; fetch the operand number
4984 from the attribute argument list. */
4987 get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp)
4989 /* Verify the arg number is a constant. */
4990 if (TREE_CODE (arg_num_expr) != INTEGER_CST
4991 || TREE_INT_CST_HIGH (arg_num_expr) != 0)
4994 *valp = TREE_INT_CST_LOW (arg_num_expr);
4998 /* Handle the "nonnull" attribute. */
5000 handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name),
5001 tree args, int ARG_UNUSED (flags),
5005 unsigned HOST_WIDE_INT attr_arg_num;
5007 /* If no arguments are specified, all pointer arguments should be
5008 non-null. Verify a full prototype is given so that the arguments
5009 will have the correct types when we actually check them later. */
5012 if (!TYPE_ARG_TYPES (type))
5014 error ("nonnull attribute without arguments on a non-prototype");
5015 *no_add_attrs = true;
5020 /* Argument list specified. Verify that each argument number references
5021 a pointer argument. */
5022 for (attr_arg_num = 1; args; args = TREE_CHAIN (args))
5025 unsigned HOST_WIDE_INT arg_num = 0, ck_num;
5027 if (!get_nonnull_operand (TREE_VALUE (args), &arg_num))
5029 error ("nonnull argument has invalid operand number (argument %lu)",
5030 (unsigned long) attr_arg_num);
5031 *no_add_attrs = true;
5035 argument = TYPE_ARG_TYPES (type);
5038 for (ck_num = 1; ; ck_num++)
5040 if (!argument || ck_num == arg_num)
5042 argument = TREE_CHAIN (argument);
5046 || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE)
5048 error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)",
5049 (unsigned long) attr_arg_num, (unsigned long) arg_num);
5050 *no_add_attrs = true;
5054 if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE)
5056 error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)",
5057 (unsigned long) attr_arg_num, (unsigned long) arg_num);
5058 *no_add_attrs = true;
5067 /* Handle a "sentinel" attribute. */
5070 handle_sentinel_attribute (tree *node, tree name, tree args,
5071 int ARG_UNUSED (flags), bool *no_add_attrs)
5073 tree params = TYPE_ARG_TYPES (*node);
5077 warning (OPT_Wattributes,
5078 "%qE attribute requires prototypes with named arguments", name);
5079 *no_add_attrs = true;
5083 while (TREE_CHAIN (params))
5084 params = TREE_CHAIN (params);
5086 if (VOID_TYPE_P (TREE_VALUE (params)))
5088 warning (OPT_Wattributes,
5089 "%qE attribute only applies to variadic functions", name);
5090 *no_add_attrs = true;
5096 tree position = TREE_VALUE (args);
5098 if (TREE_CODE (position) != INTEGER_CST)
5100 warning (0, "requested position is not an integer constant");
5101 *no_add_attrs = true;
5105 if (tree_int_cst_lt (position, integer_zero_node))
5107 warning (0, "requested position is less than zero");
5108 *no_add_attrs = true;
5116 /* Handle a "noreturn" attribute; arguments as in
5117 struct attribute_spec.handler. */
5120 handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5121 int ARG_UNUSED (flags), bool *no_add_attrs)
5123 tree type = TREE_TYPE (*node);
5125 /* See FIXME comment in c_common_attribute_table. */
5126 if (TREE_CODE (*node) == FUNCTION_DECL)
5127 TREE_THIS_VOLATILE (*node) = 1;
5128 else if (TREE_CODE (type) == POINTER_TYPE
5129 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
5131 = build_pointer_type
5132 (build_type_variant (TREE_TYPE (type),
5133 TYPE_READONLY (TREE_TYPE (type)), 1));
5136 warning (OPT_Wattributes, "%qE attribute ignored", name);
5137 *no_add_attrs = true;
5143 /* Handle a "malloc" attribute; arguments as in
5144 struct attribute_spec.handler. */
5147 handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args),
5148 int ARG_UNUSED (flags), bool *no_add_attrs)
5150 if (TREE_CODE (*node) == FUNCTION_DECL
5151 && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node))))
5152 DECL_IS_MALLOC (*node) = 1;
5155 warning (OPT_Wattributes, "%qE attribute ignored", name);
5156 *no_add_attrs = true;
5162 /* Fake handler for attributes we don't properly support. */
5165 fake_attribute_handler (tree * ARG_UNUSED (node),
5166 tree ARG_UNUSED (name),
5167 tree ARG_UNUSED (args),
5168 int ARG_UNUSED (flags),
5169 bool * ARG_UNUSED (no_add_attrs))
5174 /* Handle a "type_generic" attribute. */
5177 handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name),
5178 tree ARG_UNUSED (args), int ARG_UNUSED (flags),
5179 bool * ARG_UNUSED (no_add_attrs))
5183 /* Ensure we have a function type. */
5184 gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE);
5186 params = TYPE_ARG_TYPES (*node);
5187 while (params && ! VOID_TYPE_P (TREE_VALUE (params)))
5188 params = TREE_CHAIN (params);
5190 /* Ensure we have a variadic function. */
5191 gcc_assert (!params);
5196 /* ----------------------------------------------------------------------- *
5197 * BUILTIN FUNCTIONS *
5198 * ----------------------------------------------------------------------- */
5200 /* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two
5201 names. Does not declare a non-__builtin_ function if flag_no_builtin, or
5202 if nonansi_p and flag_no_nonansi_builtin. */
5205 def_builtin_1 (enum built_in_function fncode,
5207 enum built_in_class fnclass,
5208 tree fntype, tree libtype,
5209 bool both_p, bool fallback_p,
5210 bool nonansi_p ATTRIBUTE_UNUSED,
5211 tree fnattrs, bool implicit_p)
5214 const char *libname;
5216 /* Preserve an already installed decl. It most likely was setup in advance
5217 (e.g. as part of the internal builtins) for specific reasons. */
5218 if (built_in_decls[(int) fncode] != NULL_TREE)
5221 gcc_assert ((!both_p && !fallback_p)
5222 || !strncmp (name, "__builtin_",
5223 strlen ("__builtin_")));
5225 libname = name + strlen ("__builtin_");
5226 decl = add_builtin_function (name, fntype, fncode, fnclass,
5227 (fallback_p ? libname : NULL),
5230 /* ??? This is normally further controlled by command-line options
5231 like -fno-builtin, but we don't have them for Ada. */
5232 add_builtin_function (libname, libtype, fncode, fnclass,
5235 built_in_decls[(int) fncode] = decl;
5237 implicit_built_in_decls[(int) fncode] = decl;
5240 static int flag_isoc94 = 0;
5241 static int flag_isoc99 = 0;
5243 /* Install what the common builtins.def offers. */
5246 install_builtin_functions (void)
5248 #define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \
5249 NONANSI_P, ATTRS, IMPLICIT, COND) \
5251 def_builtin_1 (ENUM, NAME, CLASS, \
5252 builtin_types[(int) TYPE], \
5253 builtin_types[(int) LIBTYPE], \
5254 BOTH_P, FALLBACK_P, NONANSI_P, \
5255 built_in_attributes[(int) ATTRS], IMPLICIT);
5256 #include "builtins.def"
5260 /* ----------------------------------------------------------------------- *
5261 * BUILTIN FUNCTIONS *
5262 * ----------------------------------------------------------------------- */
5264 /* Install the builtin functions we might need. */
5267 gnat_install_builtins (void)
5269 install_builtin_elementary_types ();
5270 install_builtin_function_types ();
5271 install_builtin_attributes ();
5273 /* Install builtins used by generic middle-end pieces first. Some of these
5274 know about internal specificities and control attributes accordingly, for
5275 instance __builtin_alloca vs no-throw and -fstack-check. We will ignore
5276 the generic definition from builtins.def. */
5277 build_common_builtin_nodes ();
5279 /* Now, install the target specific builtins, such as the AltiVec family on
5280 ppc, and the common set as exposed by builtins.def. */
5281 targetm.init_builtins ();
5282 install_builtin_functions ();
5285 #include "gt-ada-utils.h"
5286 #include "gtype-ada.h"
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