1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2005, 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 2, 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 distributed with GNAT; see file COPYING. If not, write *
19 * to the Free Software Foundation, 51 Franklin Street, Fifth Floor, *
20 * Boston, MA 02110-1301, USA. *
22 * GNAT was originally developed by the GNAT team at New York University. *
23 * Extensive contributions were provided by Ada Core Technologies Inc. *
25 ****************************************************************************/
29 #include "coretypes.h"
42 #include "tree-inline.h"
43 #include "tree-gimple.h"
44 #include "tree-dump.h"
60 #ifndef MAX_FIXED_MODE_SIZE
61 #define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
64 #ifndef MAX_BITS_PER_WORD
65 #define MAX_BITS_PER_WORD BITS_PER_WORD
68 /* If nonzero, pretend we are allocating at global level. */
71 /* Tree nodes for the various types and decls we create. */
72 tree gnat_std_decls[(int) ADT_LAST];
74 /* Functions to call for each of the possible raise reasons. */
75 tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
77 /* List of functions called automatically at the beginning and
78 end of execution, on targets without .ctors/.dtors sections. */
82 /* Associates a GNAT tree node to a GCC tree node. It is used in
83 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
84 of `save_gnu_tree' for more info. */
85 static GTY((length ("max_gnat_nodes"))) tree *associate_gnat_to_gnu;
87 /* This variable keeps a table for types for each precision so that we only
88 allocate each of them once. Signed and unsigned types are kept separate.
90 Note that these types are only used when fold-const requests something
91 special. Perhaps we should NOT share these types; we'll see how it
93 static GTY(()) tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2];
95 /* Likewise for float types, but record these by mode. */
96 static GTY(()) tree float_types[NUM_MACHINE_MODES];
98 /* For each binding contour we allocate a binding_level structure to indicate
101 struct gnat_binding_level GTY((chain_next ("%h.chain")))
103 /* The binding level containing this one (the enclosing binding level). */
104 struct gnat_binding_level *chain;
105 /* The BLOCK node for this level. */
107 /* If nonzero, the setjmp buffer that needs to be updated for any
108 variable-sized definition within this context. */
112 /* The binding level currently in effect. */
113 static GTY(()) struct gnat_binding_level *current_binding_level;
115 /* A chain of gnat_binding_level structures awaiting reuse. */
116 static GTY((deletable)) struct gnat_binding_level *free_binding_level;
118 /* A chain of unused BLOCK nodes. */
119 static GTY((deletable)) tree free_block_chain;
121 struct language_function GTY(())
126 static void gnat_install_builtins (void);
127 static tree merge_sizes (tree, tree, tree, bool, bool);
128 static tree compute_related_constant (tree, tree);
129 static tree split_plus (tree, tree *);
130 static bool value_zerop (tree);
131 static void gnat_gimplify_function (tree);
132 static tree float_type_for_precision (int, enum machine_mode);
133 static tree convert_to_fat_pointer (tree, tree);
134 static tree convert_to_thin_pointer (tree, tree);
135 static tree make_descriptor_field (const char *,tree, tree, tree);
136 static bool value_factor_p (tree, HOST_WIDE_INT);
137 static bool potential_alignment_gap (tree, tree, tree);
139 /* Initialize the association of GNAT nodes to GCC trees. */
142 init_gnat_to_gnu (void)
144 associate_gnat_to_gnu
145 = (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
148 /* GNAT_ENTITY is a GNAT tree node for an entity. GNU_DECL is the GCC tree
149 which is to be associated with GNAT_ENTITY. Such GCC tree node is always
150 a ..._DECL node. If NO_CHECK is nonzero, the latter check is suppressed.
152 If GNU_DECL is zero, a previous association is to be reset. */
155 save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl, bool no_check)
157 /* Check that GNAT_ENTITY is not already defined and that it is being set
158 to something which is a decl. Raise gigi 401 if not. Usually, this
159 means GNAT_ENTITY is defined twice, but occasionally is due to some
161 gcc_assert (!gnu_decl
162 || (!associate_gnat_to_gnu[gnat_entity - First_Node_Id]
163 && (no_check || DECL_P (gnu_decl))));
164 associate_gnat_to_gnu[gnat_entity - First_Node_Id] = gnu_decl;
167 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
168 Return the ..._DECL node that was associated with it. If there is no tree
169 node associated with GNAT_ENTITY, abort.
171 In some cases, such as delayed elaboration or expressions that need to
172 be elaborated only once, GNAT_ENTITY is really not an entity. */
175 get_gnu_tree (Entity_Id gnat_entity)
177 gcc_assert (associate_gnat_to_gnu[gnat_entity - First_Node_Id]);
178 return associate_gnat_to_gnu[gnat_entity - First_Node_Id];
181 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
184 present_gnu_tree (Entity_Id gnat_entity)
186 return (associate_gnat_to_gnu[gnat_entity - First_Node_Id]) != 0;
190 /* Return non-zero if we are currently in the global binding level. */
193 global_bindings_p (void)
195 return ((force_global || !current_function_decl) ? -1 : 0);
198 /* Enter a new binding level. */
203 struct gnat_binding_level *newlevel = NULL;
205 /* Reuse a struct for this binding level, if there is one. */
206 if (free_binding_level)
208 newlevel = free_binding_level;
209 free_binding_level = free_binding_level->chain;
213 = (struct gnat_binding_level *)
214 ggc_alloc (sizeof (struct gnat_binding_level));
216 /* Use a free BLOCK, if any; otherwise, allocate one. */
217 if (free_block_chain)
219 newlevel->block = free_block_chain;
220 free_block_chain = TREE_CHAIN (free_block_chain);
221 TREE_CHAIN (newlevel->block) = NULL_TREE;
224 newlevel->block = make_node (BLOCK);
226 /* Point the BLOCK we just made to its parent. */
227 if (current_binding_level)
228 BLOCK_SUPERCONTEXT (newlevel->block) = current_binding_level->block;
230 BLOCK_VARS (newlevel->block) = BLOCK_SUBBLOCKS (newlevel->block) = NULL_TREE;
231 TREE_USED (newlevel->block) = 1;
233 /* Add this level to the front of the chain (stack) of levels that are
235 newlevel->chain = current_binding_level;
236 newlevel->jmpbuf_decl = NULL_TREE;
237 current_binding_level = newlevel;
240 /* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL
241 and point FNDECL to this BLOCK. */
244 set_current_block_context (tree fndecl)
246 BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl;
247 DECL_INITIAL (fndecl) = current_binding_level->block;
250 /* Set the jmpbuf_decl for the current binding level to DECL. */
253 set_block_jmpbuf_decl (tree decl)
255 current_binding_level->jmpbuf_decl = decl;
258 /* Get the jmpbuf_decl, if any, for the current binding level. */
261 get_block_jmpbuf_decl ()
263 return current_binding_level->jmpbuf_decl;
266 /* Exit a binding level. Set any BLOCK into the current code group. */
271 struct gnat_binding_level *level = current_binding_level;
272 tree block = level->block;
274 BLOCK_VARS (block) = nreverse (BLOCK_VARS (block));
275 BLOCK_SUBBLOCKS (block) = nreverse (BLOCK_SUBBLOCKS (block));
277 /* If this is a function-level BLOCK don't do anything. Otherwise, if there
278 are no variables free the block and merge its subblocks into those of its
279 parent block. Otherwise, add it to the list of its parent. */
280 if (TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)
282 else if (BLOCK_VARS (block) == NULL_TREE)
284 BLOCK_SUBBLOCKS (level->chain->block)
285 = chainon (BLOCK_SUBBLOCKS (block),
286 BLOCK_SUBBLOCKS (level->chain->block));
287 TREE_CHAIN (block) = free_block_chain;
288 free_block_chain = block;
292 TREE_CHAIN (block) = BLOCK_SUBBLOCKS (level->chain->block);
293 BLOCK_SUBBLOCKS (level->chain->block) = block;
294 TREE_USED (block) = 1;
295 set_block_for_group (block);
298 /* Free this binding structure. */
299 current_binding_level = level->chain;
300 level->chain = free_binding_level;
301 free_binding_level = level;
304 /* Insert BLOCK at the end of the list of subblocks of the
305 current binding level. This is used when a BIND_EXPR is expanded,
306 to handle the BLOCK node inside the BIND_EXPR. */
309 insert_block (tree block)
311 TREE_USED (block) = 1;
312 TREE_CHAIN (block) = BLOCK_SUBBLOCKS (current_binding_level->block);
313 BLOCK_SUBBLOCKS (current_binding_level->block) = block;
316 /* Records a ..._DECL node DECL as belonging to the current lexical scope
317 and uses GNAT_NODE for location information and propagating flags. */
320 gnat_pushdecl (tree decl, Node_Id gnat_node)
322 /* If at top level, there is no context. But PARM_DECLs always go in the
323 level of its function. */
324 if (global_bindings_p () && TREE_CODE (decl) != PARM_DECL)
325 DECL_CONTEXT (decl) = 0;
327 DECL_CONTEXT (decl) = current_function_decl;
329 TREE_NO_WARNING (decl) = (gnat_node == Empty || Warnings_Off (gnat_node));
331 /* Set the location of DECL and emit a declaration for it. */
332 if (Present (gnat_node))
333 Sloc_to_locus (Sloc (gnat_node), &DECL_SOURCE_LOCATION (decl));
334 add_decl_expr (decl, gnat_node);
336 /* Put the declaration on the list. The list of declarations is in reverse
337 order. The list will be reversed later. We don't do this for global
338 variables. Also, don't put TYPE_DECLs for UNCONSTRAINED_ARRAY_TYPE into
339 the list. They will cause trouble with the debugger and aren't needed
341 if (!global_bindings_p ()
342 && (TREE_CODE (decl) != TYPE_DECL
343 || TREE_CODE (TREE_TYPE (decl)) != UNCONSTRAINED_ARRAY_TYPE))
345 TREE_CHAIN (decl) = BLOCK_VARS (current_binding_level->block);
346 BLOCK_VARS (current_binding_level->block) = decl;
349 /* For the declaration of a type, set its name if it either is not already
350 set, was set to an IDENTIFIER_NODE, indicating an internal name,
351 or if the previous type name was not derived from a source name.
352 We'd rather have the type named with a real name and all the pointer
353 types to the same object have the same POINTER_TYPE node. Code in this
354 function in c-decl.c makes a copy of the type node here, but that may
355 cause us trouble with incomplete types, so let's not try it (at least
358 if (TREE_CODE (decl) == TYPE_DECL
360 && (!TYPE_NAME (TREE_TYPE (decl))
361 || TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == IDENTIFIER_NODE
362 || (TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == TYPE_DECL
363 && DECL_ARTIFICIAL (TYPE_NAME (TREE_TYPE (decl)))
364 && !DECL_ARTIFICIAL (decl))))
365 TYPE_NAME (TREE_TYPE (decl)) = decl;
367 /* if (TREE_CODE (decl) != CONST_DECL)
368 rest_of_decl_compilation (decl, global_bindings_p (), 0); */
371 /* Do little here. Set up the standard declarations later after the
372 front end has been run. */
375 gnat_init_decl_processing (void)
379 /* Make the binding_level structure for global names. */
380 current_function_decl = 0;
381 current_binding_level = 0;
382 free_binding_level = 0;
385 build_common_tree_nodes (true, true);
387 /* In Ada, we use a signed type for SIZETYPE. Use the signed type
388 corresponding to the size of Pmode. In most cases when ptr_mode and
389 Pmode differ, C will use the width of ptr_mode as sizetype. But we get
390 far better code using the width of Pmode. Make this here since we need
391 this before we can expand the GNAT types. */
392 size_type_node = gnat_type_for_size (GET_MODE_BITSIZE (Pmode), 0);
393 set_sizetype (size_type_node);
394 build_common_tree_nodes_2 (0);
396 /* Give names and make TYPE_DECLs for common types. */
397 gnat_pushdecl (build_decl (TYPE_DECL, get_identifier (SIZE_TYPE), sizetype),
399 gnat_pushdecl (build_decl (TYPE_DECL, get_identifier ("integer"),
402 gnat_pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned char"),
405 gnat_pushdecl (build_decl (TYPE_DECL, get_identifier ("long integer"),
406 long_integer_type_node),
409 ptr_void_type_node = build_pointer_type (void_type_node);
411 gnat_install_builtins ();
414 /* Install the builtin functions the middle-end needs. */
417 gnat_install_builtins ()
419 /* Builtins used by generic optimizers. */
420 build_common_builtin_nodes ();
422 /* Target specific builtins, such as the AltiVec family on ppc. */
423 targetm.init_builtins ();
426 /* Create the predefined scalar types such as `integer_type_node' needed
427 in the gcc back-end and initialize the global binding level. */
430 init_gigi_decls (tree long_long_float_type, tree exception_type)
435 /* Set the types that GCC and Gigi use from the front end. We would like
436 to do this for char_type_node, but it needs to correspond to the C
438 if (TREE_CODE (TREE_TYPE (long_long_float_type)) == INTEGER_TYPE)
440 /* In this case, the builtin floating point types are VAX float,
441 so make up a type for use. */
442 longest_float_type_node = make_node (REAL_TYPE);
443 TYPE_PRECISION (longest_float_type_node) = LONG_DOUBLE_TYPE_SIZE;
444 layout_type (longest_float_type_node);
445 create_type_decl (get_identifier ("longest float type"),
446 longest_float_type_node, NULL, false, true, Empty);
449 longest_float_type_node = TREE_TYPE (long_long_float_type);
451 except_type_node = TREE_TYPE (exception_type);
453 unsigned_type_node = gnat_type_for_size (INT_TYPE_SIZE, 1);
454 create_type_decl (get_identifier ("unsigned int"), unsigned_type_node,
455 NULL, false, true, Empty);
457 void_type_decl_node = create_type_decl (get_identifier ("void"),
458 void_type_node, NULL, false, true,
461 void_ftype = build_function_type (void_type_node, NULL_TREE);
462 ptr_void_ftype = build_pointer_type (void_ftype);
464 /* Now declare runtime functions. */
465 endlink = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
467 /* malloc is a function declaration tree for a function to allocate
469 malloc_decl = create_subprog_decl (get_identifier ("__gnat_malloc"),
471 build_function_type (ptr_void_type_node,
472 tree_cons (NULL_TREE,
475 NULL_TREE, false, true, true, NULL,
478 /* free is a function declaration tree for a function to free memory. */
480 = create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE,
481 build_function_type (void_type_node,
482 tree_cons (NULL_TREE,
485 NULL_TREE, false, true, true, NULL, Empty);
487 /* Make the types and functions used for exception processing. */
489 = build_array_type (gnat_type_for_mode (Pmode, 0),
490 build_index_type (build_int_cst (NULL_TREE, 5)));
491 create_type_decl (get_identifier ("JMPBUF_T"), jmpbuf_type, NULL,
493 jmpbuf_ptr_type = build_pointer_type (jmpbuf_type);
495 /* Functions to get and set the jumpbuf pointer for the current thread. */
497 = create_subprog_decl
498 (get_identifier ("system__soft_links__get_jmpbuf_address_soft"),
499 NULL_TREE, build_function_type (jmpbuf_ptr_type, NULL_TREE),
500 NULL_TREE, false, true, true, NULL, Empty);
503 = create_subprog_decl
504 (get_identifier ("system__soft_links__set_jmpbuf_address_soft"),
506 build_function_type (void_type_node,
507 tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
508 NULL_TREE, false, true, true, NULL, Empty);
510 /* Function to get the current exception. */
512 = create_subprog_decl
513 (get_identifier ("system__soft_links__get_gnat_exception"),
515 build_function_type (build_pointer_type (except_type_node), NULL_TREE),
516 NULL_TREE, false, true, true, NULL, Empty);
518 /* Functions that raise exceptions. */
520 = create_subprog_decl
521 (get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE,
522 build_function_type (void_type_node,
523 tree_cons (NULL_TREE,
524 build_pointer_type (except_type_node),
526 NULL_TREE, false, true, true, NULL, Empty);
528 /* Dummy objects to materialize "others" and "all others" in the exception
529 tables. These are exported by a-exexpr.adb, so see this unit for the
533 = create_var_decl (get_identifier ("OTHERS"),
534 get_identifier ("__gnat_others_value"),
535 integer_type_node, 0, 1, 0, 1, 1, 0, Empty);
538 = create_var_decl (get_identifier ("ALL_OTHERS"),
539 get_identifier ("__gnat_all_others_value"),
540 integer_type_node, 0, 1, 0, 1, 1, 0, Empty);
542 /* Hooks to call when entering/leaving an exception handler. */
544 = create_subprog_decl (get_identifier ("__gnat_begin_handler"), NULL_TREE,
545 build_function_type (void_type_node,
546 tree_cons (NULL_TREE,
549 NULL_TREE, false, true, true, NULL, Empty);
552 = create_subprog_decl (get_identifier ("__gnat_end_handler"), NULL_TREE,
553 build_function_type (void_type_node,
554 tree_cons (NULL_TREE,
557 NULL_TREE, false, true, true, NULL, Empty);
559 /* If in no exception handlers mode, all raise statements are redirected to
560 __gnat_last_chance_handler. No need to redefine raise_nodefer_decl, since
561 this procedure will never be called in this mode. */
562 if (No_Exception_Handlers_Set ())
565 = create_subprog_decl
566 (get_identifier ("__gnat_last_chance_handler"), NULL_TREE,
567 build_function_type (void_type_node,
568 tree_cons (NULL_TREE,
569 build_pointer_type (char_type_node),
570 tree_cons (NULL_TREE,
573 NULL_TREE, false, true, true, NULL, Empty);
575 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
576 gnat_raise_decls[i] = decl;
579 /* Otherwise, make one decl for each exception reason. */
580 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
584 sprintf (name, "__gnat_rcheck_%.2d", i);
586 = create_subprog_decl
587 (get_identifier (name), NULL_TREE,
588 build_function_type (void_type_node,
589 tree_cons (NULL_TREE,
592 tree_cons (NULL_TREE,
595 NULL_TREE, false, true, true, NULL, Empty);
598 /* Indicate that these never return. */
599 TREE_THIS_VOLATILE (raise_nodefer_decl) = 1;
600 TREE_SIDE_EFFECTS (raise_nodefer_decl) = 1;
601 TREE_TYPE (raise_nodefer_decl)
602 = build_qualified_type (TREE_TYPE (raise_nodefer_decl),
605 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
607 TREE_THIS_VOLATILE (gnat_raise_decls[i]) = 1;
608 TREE_SIDE_EFFECTS (gnat_raise_decls[i]) = 1;
609 TREE_TYPE (gnat_raise_decls[i])
610 = build_qualified_type (TREE_TYPE (gnat_raise_decls[i]),
614 /* setjmp returns an integer and has one operand, which is a pointer to
617 = create_subprog_decl
618 (get_identifier ("__builtin_setjmp"), NULL_TREE,
619 build_function_type (integer_type_node,
620 tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
621 NULL_TREE, false, true, true, NULL, Empty);
623 DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL;
624 DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP;
626 /* update_setjmp_buf updates a setjmp buffer from the current stack pointer
628 update_setjmp_buf_decl
629 = create_subprog_decl
630 (get_identifier ("__builtin_update_setjmp_buf"), NULL_TREE,
631 build_function_type (void_type_node,
632 tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
633 NULL_TREE, false, true, true, NULL, Empty);
635 DECL_BUILT_IN_CLASS (update_setjmp_buf_decl) = BUILT_IN_NORMAL;
636 DECL_FUNCTION_CODE (update_setjmp_buf_decl) = BUILT_IN_UPDATE_SETJMP_BUF;
638 main_identifier_node = get_identifier ("main");
641 /* Given a record type (RECORD_TYPE) and a chain of FIELD_DECL nodes
642 (FIELDLIST), finish constructing the record or union type. If HAS_REP is
643 true, this record has a rep clause; don't call layout_type but merely set
644 the size and alignment ourselves. If DEFER_DEBUG is true, do not call
645 the debugging routines on this type; it will be done later. */
648 finish_record_type (tree record_type, tree fieldlist, bool has_rep,
651 enum tree_code code = TREE_CODE (record_type);
652 tree ada_size = bitsize_zero_node;
653 tree size = bitsize_zero_node;
654 bool var_size = false;
655 bool had_size = TYPE_SIZE (record_type) != 0;
656 bool had_size_unit = TYPE_SIZE_UNIT (record_type) != 0;
659 TYPE_FIELDS (record_type) = fieldlist;
660 TYPE_STUB_DECL (record_type)
661 = build_decl (TYPE_DECL, NULL_TREE, record_type);
663 /* We don't need both the typedef name and the record name output in
664 the debugging information, since they are the same. */
665 DECL_ARTIFICIAL (TYPE_STUB_DECL (record_type)) = 1;
667 /* Globally initialize the record first. If this is a rep'ed record,
668 that just means some initializations; otherwise, layout the record. */
672 TYPE_ALIGN (record_type) = MAX (BITS_PER_UNIT, TYPE_ALIGN (record_type));
673 TYPE_MODE (record_type) = BLKmode;
676 TYPE_SIZE_UNIT (record_type) = size_zero_node;
678 TYPE_SIZE (record_type) = bitsize_zero_node;
680 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
681 out just like a UNION_TYPE, since the size will be fixed. */
682 else if (code == QUAL_UNION_TYPE)
687 /* Ensure there isn't a size already set. There can be in an error
688 case where there is a rep clause but all fields have errors and
689 no longer have a position. */
690 TYPE_SIZE (record_type) = 0;
691 layout_type (record_type);
694 /* At this point, the position and size of each field is known. It was
695 either set before entry by a rep clause, or by laying out the type above.
697 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
698 to compute the Ada size; the GCC size and alignment (for rep'ed records
699 that are not padding types); and the mode (for rep'ed records). We also
700 clear the DECL_BIT_FIELD indication for the cases we know have not been
701 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
703 if (code == QUAL_UNION_TYPE)
704 fieldlist = nreverse (fieldlist);
706 for (field = fieldlist; field; field = TREE_CHAIN (field))
708 tree pos = bit_position (field);
710 tree type = TREE_TYPE (field);
711 tree this_size = DECL_SIZE (field);
712 tree this_ada_size = DECL_SIZE (field);
714 /* We need to make an XVE/XVU record if any field has variable size,
715 whether or not the record does. For example, if we have an union,
716 it may be that all fields, rounded up to the alignment, have the
717 same size, in which case we'll use that size. But the debug
718 output routines (except Dwarf2) won't be able to output the fields,
719 so we need to make the special record. */
720 if (TREE_CODE (this_size) != INTEGER_CST)
723 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
724 || TREE_CODE (type) == QUAL_UNION_TYPE)
725 && !TYPE_IS_FAT_POINTER_P (type)
726 && !TYPE_CONTAINS_TEMPLATE_P (type)
727 && TYPE_ADA_SIZE (type))
728 this_ada_size = TYPE_ADA_SIZE (type);
730 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
731 if (DECL_BIT_FIELD (field) && !STRICT_ALIGNMENT
732 && value_factor_p (pos, BITS_PER_UNIT)
733 && operand_equal_p (this_size, TYPE_SIZE (type), 0))
734 DECL_BIT_FIELD (field) = 0;
736 /* If we still have DECL_BIT_FIELD set at this point, we know the field
737 is technically not addressable. Except that it can actually be
738 addressed if the field is BLKmode and happens to be properly
740 DECL_NONADDRESSABLE_P (field)
741 |= DECL_BIT_FIELD (field) && DECL_MODE (field) != BLKmode;
743 if (has_rep && !DECL_BIT_FIELD (field))
744 TYPE_ALIGN (record_type)
745 = MAX (TYPE_ALIGN (record_type), DECL_ALIGN (field));
750 ada_size = size_binop (MAX_EXPR, ada_size, this_ada_size);
751 size = size_binop (MAX_EXPR, size, this_size);
754 case QUAL_UNION_TYPE:
756 = fold (build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
757 this_ada_size, ada_size));
758 size = fold (build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
763 /* Since we know here that all fields are sorted in order of
764 increasing bit position, the size of the record is one
765 higher than the ending bit of the last field processed
766 unless we have a rep clause, since in that case we might
767 have a field outside a QUAL_UNION_TYPE that has a higher ending
768 position. So use a MAX in that case. Also, if this field is a
769 QUAL_UNION_TYPE, we need to take into account the previous size in
770 the case of empty variants. */
772 = merge_sizes (ada_size, pos, this_ada_size,
773 TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
774 size = merge_sizes (size, pos, this_size,
775 TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
783 if (code == QUAL_UNION_TYPE)
784 nreverse (fieldlist);
786 /* If this is a padding record, we never want to make the size smaller than
787 what was specified in it, if any. */
788 if (TREE_CODE (record_type) == RECORD_TYPE
789 && TYPE_IS_PADDING_P (record_type) && TYPE_SIZE (record_type))
790 size = TYPE_SIZE (record_type);
792 /* Now set any of the values we've just computed that apply. */
793 if (!TYPE_IS_FAT_POINTER_P (record_type)
794 && !TYPE_CONTAINS_TEMPLATE_P (record_type))
795 SET_TYPE_ADA_SIZE (record_type, ada_size);
800 = (had_size_unit ? TYPE_SIZE_UNIT (record_type)
801 : convert (sizetype, size_binop (CEIL_DIV_EXPR, size,
802 bitsize_unit_node)));
804 TYPE_SIZE (record_type)
805 = variable_size (round_up (size, TYPE_ALIGN (record_type)));
806 TYPE_SIZE_UNIT (record_type)
807 = variable_size (round_up (size_unit,
808 TYPE_ALIGN (record_type) / BITS_PER_UNIT));
810 compute_record_mode (record_type);
814 write_record_type_debug_info (record_type);
817 /* Output the debug information associated to a record type. */
820 write_record_type_debug_info (tree record_type)
822 tree fieldlist = TYPE_FIELDS (record_type);
824 bool var_size = false;
826 for (field = fieldlist; field; field = TREE_CHAIN (field))
828 /* We need to make an XVE/XVU record if any field has variable size,
829 whether or not the record does. For example, if we have an union,
830 it may be that all fields, rounded up to the alignment, have the
831 same size, in which case we'll use that size. But the debug
832 output routines (except Dwarf2) won't be able to output the fields,
833 so we need to make the special record. */
834 if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST)
841 /* If this record is of variable size, rename it so that the
842 debugger knows it is and make a new, parallel, record
843 that tells the debugger how the record is laid out. See
844 exp_dbug.ads. But don't do this for records that are padding
845 since they confuse GDB. */
847 && !(TREE_CODE (record_type) == RECORD_TYPE
848 && TYPE_IS_PADDING_P (record_type)))
851 = make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE
852 ? UNION_TYPE : TREE_CODE (record_type));
853 tree orig_name = TYPE_NAME (record_type);
855 = (TREE_CODE (orig_name) == TYPE_DECL ? DECL_NAME (orig_name)
858 = concat_id_with_name (orig_id,
859 TREE_CODE (record_type) == QUAL_UNION_TYPE
861 tree last_pos = bitsize_zero_node;
863 tree prev_old_field = 0;
865 TYPE_NAME (new_record_type) = new_id;
866 TYPE_ALIGN (new_record_type) = BIGGEST_ALIGNMENT;
867 TYPE_STUB_DECL (new_record_type)
868 = build_decl (TYPE_DECL, NULL_TREE, new_record_type);
869 DECL_ARTIFICIAL (TYPE_STUB_DECL (new_record_type)) = 1;
870 DECL_IGNORED_P (TYPE_STUB_DECL (new_record_type))
871 = DECL_IGNORED_P (TYPE_STUB_DECL (record_type));
872 TYPE_SIZE (new_record_type) = size_int (TYPE_ALIGN (record_type));
873 TYPE_SIZE_UNIT (new_record_type)
874 = size_int (TYPE_ALIGN (record_type) / BITS_PER_UNIT);
876 /* Now scan all the fields, replacing each field with a new
877 field corresponding to the new encoding. */
878 for (old_field = TYPE_FIELDS (record_type); old_field;
879 old_field = TREE_CHAIN (old_field))
881 tree field_type = TREE_TYPE (old_field);
882 tree field_name = DECL_NAME (old_field);
884 tree curpos = bit_position (old_field);
886 unsigned int align = 0;
889 /* See how the position was modified from the last position.
891 There are two basic cases we support: a value was added
892 to the last position or the last position was rounded to
893 a boundary and they something was added. Check for the
894 first case first. If not, see if there is any evidence
895 of rounding. If so, round the last position and try
898 If this is a union, the position can be taken as zero. */
900 if (TREE_CODE (new_record_type) == UNION_TYPE)
901 pos = bitsize_zero_node, align = 0;
903 pos = compute_related_constant (curpos, last_pos);
905 if (!pos && TREE_CODE (curpos) == MULT_EXPR
906 && TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST)
908 align = TREE_INT_CST_LOW (TREE_OPERAND (curpos, 1));
909 pos = compute_related_constant (curpos,
910 round_up (last_pos, align));
912 else if (!pos && TREE_CODE (curpos) == PLUS_EXPR
913 && TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST
914 && TREE_CODE (TREE_OPERAND (curpos, 0)) == MULT_EXPR
915 && host_integerp (TREE_OPERAND
916 (TREE_OPERAND (curpos, 0), 1),
921 (TREE_OPERAND (TREE_OPERAND (curpos, 0), 1), 1);
922 pos = compute_related_constant (curpos,
923 round_up (last_pos, align));
925 else if (potential_alignment_gap (prev_old_field, old_field,
928 align = TYPE_ALIGN (field_type);
929 pos = compute_related_constant (curpos,
930 round_up (last_pos, align));
933 /* If we can't compute a position, set it to zero.
935 ??? We really should abort here, but it's too much work
936 to get this correct for all cases. */
939 pos = bitsize_zero_node;
941 /* See if this type is variable-size and make a new type
942 and indicate the indirection if so. */
943 if (TREE_CODE (DECL_SIZE (old_field)) != INTEGER_CST)
945 field_type = build_pointer_type (field_type);
949 /* Make a new field name, if necessary. */
950 if (var || align != 0)
955 sprintf (suffix, "XV%c%u", var ? 'L' : 'A',
956 align / BITS_PER_UNIT);
958 strcpy (suffix, "XVL");
960 field_name = concat_id_with_name (field_name, suffix);
963 new_field = create_field_decl (field_name, field_type,
965 DECL_SIZE (old_field), pos, 0);
966 TREE_CHAIN (new_field) = TYPE_FIELDS (new_record_type);
967 TYPE_FIELDS (new_record_type) = new_field;
969 /* If old_field is a QUAL_UNION_TYPE, take its size as being
970 zero. The only time it's not the last field of the record
971 is when there are other components at fixed positions after
972 it (meaning there was a rep clause for every field) and we
973 want to be able to encode them. */
974 last_pos = size_binop (PLUS_EXPR, bit_position (old_field),
975 (TREE_CODE (TREE_TYPE (old_field))
978 : DECL_SIZE (old_field));
979 prev_old_field = old_field;
982 TYPE_FIELDS (new_record_type)
983 = nreverse (TYPE_FIELDS (new_record_type));
985 rest_of_type_compilation (new_record_type, global_bindings_p ());
988 rest_of_type_compilation (record_type, global_bindings_p ());
991 /* Utility function of above to merge LAST_SIZE, the previous size of a record
992 with FIRST_BIT and SIZE that describe a field. SPECIAL is nonzero
993 if this represents a QUAL_UNION_TYPE in which case we must look for
994 COND_EXPRs and replace a value of zero with the old size. If HAS_REP
995 is nonzero, we must take the MAX of the end position of this field
996 with LAST_SIZE. In all other cases, we use FIRST_BIT plus SIZE.
998 We return an expression for the size. */
1001 merge_sizes (tree last_size, tree first_bit, tree size, bool special,
1004 tree type = TREE_TYPE (last_size);
1007 if (!special || TREE_CODE (size) != COND_EXPR)
1009 new = size_binop (PLUS_EXPR, first_bit, size);
1011 new = size_binop (MAX_EXPR, last_size, new);
1015 new = fold (build3 (COND_EXPR, type, TREE_OPERAND (size, 0),
1016 integer_zerop (TREE_OPERAND (size, 1))
1017 ? last_size : merge_sizes (last_size, first_bit,
1018 TREE_OPERAND (size, 1),
1020 integer_zerop (TREE_OPERAND (size, 2))
1021 ? last_size : merge_sizes (last_size, first_bit,
1022 TREE_OPERAND (size, 2),
1025 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
1026 when fed through substitute_in_expr) into thinking that a constant
1027 size is not constant. */
1028 while (TREE_CODE (new) == NON_LVALUE_EXPR)
1029 new = TREE_OPERAND (new, 0);
1034 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
1035 related by the addition of a constant. Return that constant if so. */
1038 compute_related_constant (tree op0, tree op1)
1040 tree op0_var, op1_var;
1041 tree op0_con = split_plus (op0, &op0_var);
1042 tree op1_con = split_plus (op1, &op1_var);
1043 tree result = size_binop (MINUS_EXPR, op0_con, op1_con);
1045 if (operand_equal_p (op0_var, op1_var, 0))
1047 else if (operand_equal_p (op0, size_binop (PLUS_EXPR, op1_var, result), 0))
1053 /* Utility function of above to split a tree OP which may be a sum, into a
1054 constant part, which is returned, and a variable part, which is stored
1055 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
1059 split_plus (tree in, tree *pvar)
1061 /* Strip NOPS in order to ease the tree traversal and maximize the
1062 potential for constant or plus/minus discovery. We need to be careful
1063 to always return and set *pvar to bitsizetype trees, but it's worth
1067 *pvar = convert (bitsizetype, in);
1069 if (TREE_CODE (in) == INTEGER_CST)
1071 *pvar = bitsize_zero_node;
1072 return convert (bitsizetype, in);
1074 else if (TREE_CODE (in) == PLUS_EXPR || TREE_CODE (in) == MINUS_EXPR)
1076 tree lhs_var, rhs_var;
1077 tree lhs_con = split_plus (TREE_OPERAND (in, 0), &lhs_var);
1078 tree rhs_con = split_plus (TREE_OPERAND (in, 1), &rhs_var);
1080 if (lhs_var == TREE_OPERAND (in, 0)
1081 && rhs_var == TREE_OPERAND (in, 1))
1082 return bitsize_zero_node;
1084 *pvar = size_binop (TREE_CODE (in), lhs_var, rhs_var);
1085 return size_binop (TREE_CODE (in), lhs_con, rhs_con);
1088 return bitsize_zero_node;
1091 /* Return a FUNCTION_TYPE node. RETURN_TYPE is the type returned by the
1092 subprogram. If it is void_type_node, then we are dealing with a procedure,
1093 otherwise we are dealing with a function. PARAM_DECL_LIST is a list of
1094 PARM_DECL nodes that are the subprogram arguments. CICO_LIST is the
1095 copy-in/copy-out list to be stored into TYPE_CICO_LIST.
1096 RETURNS_UNCONSTRAINED is nonzero if the function returns an unconstrained
1097 object. RETURNS_BY_REF is nonzero if the function returns by reference.
1098 RETURNS_WITH_DSP is nonzero if the function is to return with a
1099 depressed stack pointer. RETURNS_BY_TARGET_PTR is true if the function
1100 is to be passed (as its first parameter) the address of the place to copy
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_with_dsp, 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_STACK_DEPRESSED (type) = returns_with_dsp;
1144 TYPE_RETURNS_BY_REF_P (type) = returns_by_ref;
1145 TYPE_RETURNS_BY_TARGET_PTR_P (type) = returns_by_target_ptr;
1149 /* Return a copy of TYPE but safe to modify in any way. */
1152 copy_type (tree type)
1154 tree new = copy_node (type);
1156 /* copy_node clears this field instead of copying it, because it is
1157 aliased with TREE_CHAIN. */
1158 TYPE_STUB_DECL (new) = TYPE_STUB_DECL (type);
1160 TYPE_POINTER_TO (new) = 0;
1161 TYPE_REFERENCE_TO (new) = 0;
1162 TYPE_MAIN_VARIANT (new) = new;
1163 TYPE_NEXT_VARIANT (new) = 0;
1168 /* Return an INTEGER_TYPE of SIZETYPE with range MIN to MAX and whose
1169 TYPE_INDEX_TYPE is INDEX. */
1172 create_index_type (tree min, tree max, tree index)
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, Empty);
1192 /* Return a TYPE_DECL node. TYPE_NAME gives the name of the type (a character
1193 string) and TYPE is a ..._TYPE node giving its data type.
1194 ARTIFICIAL_P is true if this is a declaration that was generated
1195 by the compiler. DEBUG_INFO_P is true if we need to write debugging
1196 information about this type. GNAT_NODE is used for the position of
1200 create_type_decl (tree type_name, tree type, struct attrib *attr_list,
1201 bool artificial_p, bool debug_info_p, Node_Id gnat_node)
1203 tree type_decl = build_decl (TYPE_DECL, type_name, type);
1204 enum tree_code code = TREE_CODE (type);
1206 DECL_ARTIFICIAL (type_decl) = artificial_p;
1208 process_attributes (type_decl, attr_list);
1210 /* Pass type declaration information to the debugger unless this is an
1211 UNCONSTRAINED_ARRAY_TYPE, which the debugger does not support,
1212 and ENUMERAL_TYPE or RECORD_TYPE which is handled separately,
1213 a dummy type, which will be completed later, or a type for which
1214 debugging information was not requested. */
1215 if (code == UNCONSTRAINED_ARRAY_TYPE || TYPE_IS_DUMMY_P (type)
1217 DECL_IGNORED_P (type_decl) = 1;
1218 else if (code != ENUMERAL_TYPE && code != RECORD_TYPE
1219 && !((code == POINTER_TYPE || code == REFERENCE_TYPE)
1220 && TYPE_IS_DUMMY_P (TREE_TYPE (type))))
1221 rest_of_decl_compilation (type_decl, global_bindings_p (), 0);
1223 if (!TYPE_IS_DUMMY_P (type))
1224 gnat_pushdecl (type_decl, gnat_node);
1229 /* Returns a GCC VAR_DECL node. VAR_NAME gives the name of the variable.
1230 ASM_NAME is its assembler name (if provided). TYPE is its data type
1231 (a GCC ..._TYPE node). VAR_INIT is the GCC tree for an optional initial
1232 expression; NULL_TREE if none.
1234 CONST_FLAG is true if this variable is constant.
1236 PUBLIC_FLAG is true if this definition is to be made visible outside of
1237 the current compilation unit. This flag should be set when processing the
1238 variable definitions in a package specification. EXTERN_FLAG is nonzero
1239 when processing an external variable declaration (as opposed to a
1240 definition: no storage is to be allocated for the variable here).
1242 STATIC_FLAG is only relevant when not at top level. In that case
1243 it indicates whether to always allocate storage to the variable.
1245 GNAT_NODE is used for the position of the decl. */
1248 create_var_decl (tree var_name, tree asm_name, tree type, tree var_init,
1249 bool const_flag, bool public_flag, bool extern_flag,
1250 bool static_flag, struct attrib *attr_list, Node_Id gnat_node)
1255 : (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (var_init))
1256 && (global_bindings_p () || static_flag
1257 ? 0 != initializer_constant_valid_p (var_init,
1258 TREE_TYPE (var_init))
1259 : TREE_CONSTANT (var_init))));
1261 = build_decl ((const_flag && init_const
1262 /* Only make a CONST_DECL for sufficiently-small objects.
1263 We consider complex double "sufficiently-small" */
1264 && TYPE_SIZE (type) != 0
1265 && host_integerp (TYPE_SIZE_UNIT (type), 1)
1266 && 0 >= compare_tree_int (TYPE_SIZE_UNIT (type),
1267 GET_MODE_SIZE (DCmode)))
1268 ? CONST_DECL : VAR_DECL, var_name, type);
1270 /* If this is external, throw away any initializations unless this is a
1271 CONST_DECL (meaning we have a constant); they will be done elsewhere.
1272 If we are defining a global here, leave a constant initialization and
1273 save any variable elaborations for the elaboration routine. If we are
1274 just annotating types, throw away the initialization if it isn't a
1276 if ((extern_flag && TREE_CODE (var_decl) != CONST_DECL)
1277 || (type_annotate_only && var_init && !TREE_CONSTANT (var_init)))
1278 var_init = NULL_TREE;
1280 /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't
1281 try to fiddle with DECL_COMMON. However, on platforms that don't
1282 support global BSS sections, uninitialized global variables would
1283 go in DATA instead, thus increasing the size of the executable. */
1284 #if !defined(ASM_OUTPUT_BSS) && !defined(ASM_OUTPUT_ALIGNED_BSS)
1285 DECL_COMMON (var_decl) = !flag_no_common;
1287 DECL_INITIAL (var_decl) = var_init;
1288 TREE_READONLY (var_decl) = const_flag;
1289 DECL_EXTERNAL (var_decl) = extern_flag;
1290 TREE_PUBLIC (var_decl) = public_flag || extern_flag;
1291 TREE_CONSTANT (var_decl) = TREE_CODE (var_decl) == CONST_DECL;
1292 TREE_THIS_VOLATILE (var_decl) = TREE_SIDE_EFFECTS (var_decl)
1293 = TYPE_VOLATILE (type);
1295 /* If it's public and not external, always allocate storage for it.
1296 At the global binding level we need to allocate static storage for the
1297 variable if and only if it's not external. If we are not at the top level
1298 we allocate automatic storage unless requested not to. */
1299 TREE_STATIC (var_decl)
1300 = public_flag || (global_bindings_p () ? !extern_flag : static_flag);
1303 SET_DECL_ASSEMBLER_NAME (var_decl, asm_name);
1305 process_attributes (var_decl, attr_list);
1307 /* Add this decl to the current binding level. */
1308 gnat_pushdecl (var_decl, gnat_node);
1310 if (TREE_SIDE_EFFECTS (var_decl))
1311 TREE_ADDRESSABLE (var_decl) = 1;
1313 if (TREE_CODE (var_decl) != CONST_DECL)
1314 rest_of_decl_compilation (var_decl, global_bindings_p (), 0);
1319 /* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its
1320 type, and RECORD_TYPE is the type of the parent. PACKED is nonzero if
1321 this field is in a record type with a "pragma pack". If SIZE is nonzero
1322 it is the specified size for this field. If POS is nonzero, it is the bit
1323 position. If ADDRESSABLE is nonzero, it means we are allowed to take
1324 the address of this field for aliasing purposes. If it is negative, we
1325 should not make a bitfield, which is used by make_aligning_type. */
1328 create_field_decl (tree field_name, tree field_type, tree record_type,
1329 int packed, tree size, tree pos, int addressable)
1331 tree field_decl = build_decl (FIELD_DECL, field_name, field_type);
1333 DECL_CONTEXT (field_decl) = record_type;
1334 TREE_READONLY (field_decl) = TYPE_READONLY (field_type);
1336 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
1337 byte boundary since GCC cannot handle less-aligned BLKmode bitfields. */
1338 if (packed && TYPE_MODE (field_type) == BLKmode)
1339 DECL_ALIGN (field_decl) = BITS_PER_UNIT;
1341 /* If a size is specified, use it. Otherwise, if the record type is packed
1342 compute a size to use, which may differ from the object's natural size.
1343 We always set a size in this case to trigger the checks for bitfield
1344 creation below, which is typically required when no position has been
1347 size = convert (bitsizetype, size);
1348 else if (packed == 1)
1350 size = rm_size (field_type);
1352 /* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to
1354 if (TREE_CODE (size) == INTEGER_CST
1355 && compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0)
1356 size = round_up (size, BITS_PER_UNIT);
1359 /* If we may, according to ADDRESSABLE, make a bitfield if a size is
1360 specified for two reasons: first if the size differs from the natural
1361 size. Second, if the alignment is insufficient. There are a number of
1362 ways the latter can be true.
1364 We never make a bitfield if the type of the field has a nonconstant size,
1365 because no such entity requiring bitfield operations should reach here.
1367 We do *preventively* make a bitfield when there might be the need for it
1368 but we don't have all the necessary information to decide, as is the case
1369 of a field with no specified position in a packed record.
1371 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
1372 in layout_decl or finish_record_type to clear the bit_field indication if
1373 it is in fact not needed. */
1374 if (addressable >= 0
1376 && TREE_CODE (size) == INTEGER_CST
1377 && TREE_CODE (TYPE_SIZE (field_type)) == INTEGER_CST
1378 && (!operand_equal_p (TYPE_SIZE (field_type), size, 0)
1379 || (pos && !value_factor_p (pos, TYPE_ALIGN (field_type)))
1381 || (TYPE_ALIGN (record_type) != 0
1382 && TYPE_ALIGN (record_type) < TYPE_ALIGN (field_type))))
1384 DECL_BIT_FIELD (field_decl) = 1;
1385 DECL_SIZE (field_decl) = size;
1386 if (!packed && !pos)
1387 DECL_ALIGN (field_decl)
1388 = (TYPE_ALIGN (record_type) != 0
1389 ? MIN (TYPE_ALIGN (record_type), TYPE_ALIGN (field_type))
1390 : TYPE_ALIGN (field_type));
1393 DECL_PACKED (field_decl) = pos ? DECL_BIT_FIELD (field_decl) : packed;
1394 DECL_ALIGN (field_decl)
1395 = MAX (DECL_ALIGN (field_decl),
1396 DECL_BIT_FIELD (field_decl) ? 1
1397 : packed && TYPE_MODE (field_type) != BLKmode ? BITS_PER_UNIT
1398 : TYPE_ALIGN (field_type));
1402 /* We need to pass in the alignment the DECL is known to have.
1403 This is the lowest-order bit set in POS, but no more than
1404 the alignment of the record, if one is specified. Note
1405 that an alignment of 0 is taken as infinite. */
1406 unsigned int known_align;
1408 if (host_integerp (pos, 1))
1409 known_align = tree_low_cst (pos, 1) & - tree_low_cst (pos, 1);
1411 known_align = BITS_PER_UNIT;
1413 if (TYPE_ALIGN (record_type)
1414 && (known_align == 0 || known_align > TYPE_ALIGN (record_type)))
1415 known_align = TYPE_ALIGN (record_type);
1417 layout_decl (field_decl, known_align);
1418 SET_DECL_OFFSET_ALIGN (field_decl,
1419 host_integerp (pos, 1) ? BIGGEST_ALIGNMENT
1421 pos_from_bit (&DECL_FIELD_OFFSET (field_decl),
1422 &DECL_FIELD_BIT_OFFSET (field_decl),
1423 DECL_OFFSET_ALIGN (field_decl), pos);
1425 DECL_HAS_REP_P (field_decl) = 1;
1428 /* If the field type is passed by reference, we will have pointers to the
1429 field, so it is addressable. */
1430 if (must_pass_by_ref (field_type) || default_pass_by_ref (field_type))
1433 /* ??? For now, we say that any field of aggregate type is addressable
1434 because the front end may take 'Reference of it. */
1435 if (AGGREGATE_TYPE_P (field_type))
1438 /* Mark the decl as nonaddressable if it is indicated so semantically,
1439 meaning we won't ever attempt to take the address of the field.
1441 It may also be "technically" nonaddressable, meaning that even if we
1442 attempt to take the field's address we will actually get the address of a
1443 copy. This is the case for true bitfields, but the DECL_BIT_FIELD value
1444 we have at this point is not accurate enough, so we don't account for
1445 this here and let finish_record_type decide. */
1446 DECL_NONADDRESSABLE_P (field_decl) = !addressable;
1451 /* Subroutine of previous function: return nonzero if EXP, ignoring any side
1452 effects, has the value of zero. */
1455 value_zerop (tree exp)
1457 if (TREE_CODE (exp) == COMPOUND_EXPR)
1458 return value_zerop (TREE_OPERAND (exp, 1));
1460 return integer_zerop (exp);
1463 /* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter,
1464 PARAM_TYPE is its type. READONLY is true if the parameter is
1465 readonly (either an IN parameter or an address of a pass-by-ref
1469 create_param_decl (tree param_name, tree param_type, bool readonly)
1471 tree param_decl = build_decl (PARM_DECL, param_name, param_type);
1473 /* Honor targetm.calls.promote_prototypes(), as not doing so can
1474 lead to various ABI violations. */
1475 if (targetm.calls.promote_prototypes (param_type)
1476 && (TREE_CODE (param_type) == INTEGER_TYPE
1477 || TREE_CODE (param_type) == ENUMERAL_TYPE)
1478 && TYPE_PRECISION (param_type) < TYPE_PRECISION (integer_type_node))
1480 /* We have to be careful about biased types here. Make a subtype
1481 of integer_type_node with the proper biasing. */
1482 if (TREE_CODE (param_type) == INTEGER_TYPE
1483 && TYPE_BIASED_REPRESENTATION_P (param_type))
1486 = copy_type (build_range_type (integer_type_node,
1487 TYPE_MIN_VALUE (param_type),
1488 TYPE_MAX_VALUE (param_type)));
1490 TYPE_BIASED_REPRESENTATION_P (param_type) = 1;
1493 param_type = integer_type_node;
1496 DECL_ARG_TYPE (param_decl) = param_type;
1497 TREE_READONLY (param_decl) = readonly;
1501 /* Given a DECL and ATTR_LIST, process the listed attributes. */
1504 process_attributes (tree decl, struct attrib *attr_list)
1506 for (; attr_list; attr_list = attr_list->next)
1507 switch (attr_list->type)
1509 case ATTR_MACHINE_ATTRIBUTE:
1510 decl_attributes (&decl, tree_cons (attr_list->name, attr_list->args,
1512 ATTR_FLAG_TYPE_IN_PLACE);
1515 case ATTR_LINK_ALIAS:
1516 if (! DECL_EXTERNAL (decl))
1518 TREE_STATIC (decl) = 1;
1519 assemble_alias (decl, attr_list->name);
1523 case ATTR_WEAK_EXTERNAL:
1525 declare_weak (decl);
1527 post_error ("?weak declarations not supported on this target",
1528 attr_list->error_point);
1531 case ATTR_LINK_SECTION:
1532 if (targetm.have_named_sections)
1534 DECL_SECTION_NAME (decl)
1535 = build_string (IDENTIFIER_LENGTH (attr_list->name),
1536 IDENTIFIER_POINTER (attr_list->name));
1537 DECL_COMMON (decl) = 0;
1540 post_error ("?section attributes are not supported for this target",
1541 attr_list->error_point);
1544 case ATTR_LINK_CONSTRUCTOR:
1545 DECL_STATIC_CONSTRUCTOR (decl) = 1;
1546 TREE_USED (decl) = 1;
1549 case ATTR_LINK_DESTRUCTOR:
1550 DECL_STATIC_DESTRUCTOR (decl) = 1;
1551 TREE_USED (decl) = 1;
1556 /* Return true if VALUE is a known to be a multiple of FACTOR, which must be
1560 value_factor_p (tree value, HOST_WIDE_INT factor)
1562 if (host_integerp (value, 1))
1563 return tree_low_cst (value, 1) % factor == 0;
1565 if (TREE_CODE (value) == MULT_EXPR)
1566 return (value_factor_p (TREE_OPERAND (value, 0), factor)
1567 || value_factor_p (TREE_OPERAND (value, 1), factor));
1572 /* Given 2 consecutive field decls PREV_FIELD and CURR_FIELD, return true
1573 unless we can prove these 2 fields are laid out in such a way that no gap
1574 exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET
1575 is the distance in bits between the end of PREV_FIELD and the starting
1576 position of CURR_FIELD. It is ignored if null. */
1579 potential_alignment_gap (tree prev_field, tree curr_field, tree offset)
1581 /* If this is the first field of the record, there cannot be any gap */
1585 /* If the previous field is a union type, then return False: The only
1586 time when such a field is not the last field of the record is when
1587 there are other components at fixed positions after it (meaning there
1588 was a rep clause for every field), in which case we don't want the
1589 alignment constraint to override them. */
1590 if (TREE_CODE (TREE_TYPE (prev_field)) == QUAL_UNION_TYPE)
1593 /* If the distance between the end of prev_field and the beginning of
1594 curr_field is constant, then there is a gap if the value of this
1595 constant is not null. */
1596 if (offset && host_integerp (offset, 1))
1597 return !integer_zerop (offset);
1599 /* If the size and position of the previous field are constant,
1600 then check the sum of this size and position. There will be a gap
1601 iff it is not multiple of the current field alignment. */
1602 if (host_integerp (DECL_SIZE (prev_field), 1)
1603 && host_integerp (bit_position (prev_field), 1))
1604 return ((tree_low_cst (bit_position (prev_field), 1)
1605 + tree_low_cst (DECL_SIZE (prev_field), 1))
1606 % DECL_ALIGN (curr_field) != 0);
1608 /* If both the position and size of the previous field are multiples
1609 of the current field alignment, there can not be any gap. */
1610 if (value_factor_p (bit_position (prev_field), DECL_ALIGN (curr_field))
1611 && value_factor_p (DECL_SIZE (prev_field), DECL_ALIGN (curr_field)))
1614 /* Fallback, return that there may be a potential gap */
1618 /* Returns a LABEL_DECL node for LABEL_NAME. */
1621 create_label_decl (tree label_name)
1623 tree label_decl = build_decl (LABEL_DECL, label_name, void_type_node);
1625 DECL_CONTEXT (label_decl) = current_function_decl;
1626 DECL_MODE (label_decl) = VOIDmode;
1627 DECL_SOURCE_LOCATION (label_decl) = input_location;
1632 /* Returns a FUNCTION_DECL node. SUBPROG_NAME is the name of the subprogram,
1633 ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE
1634 node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of
1635 PARM_DECL nodes chained through the TREE_CHAIN field).
1637 INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, and ATTR_LIST are used to set the
1638 appropriate fields in the FUNCTION_DECL. GNAT_NODE gives the location. */
1641 create_subprog_decl (tree subprog_name, tree asm_name,
1642 tree subprog_type, tree param_decl_list, bool inline_flag,
1643 bool public_flag, bool extern_flag,
1644 struct attrib *attr_list, Node_Id gnat_node)
1646 tree return_type = TREE_TYPE (subprog_type);
1647 tree subprog_decl = build_decl (FUNCTION_DECL, subprog_name, subprog_type);
1649 /* If this is a function nested inside an inlined external function, it
1650 means we aren't going to compile the outer function unless it is
1651 actually inlined, so do the same for us. */
1652 if (current_function_decl && DECL_INLINE (current_function_decl)
1653 && DECL_EXTERNAL (current_function_decl))
1656 DECL_EXTERNAL (subprog_decl) = extern_flag;
1657 TREE_PUBLIC (subprog_decl) = public_flag;
1658 TREE_STATIC (subprog_decl) = 1;
1659 TREE_READONLY (subprog_decl) = TYPE_READONLY (subprog_type);
1660 TREE_THIS_VOLATILE (subprog_decl) = TYPE_VOLATILE (subprog_type);
1661 TREE_SIDE_EFFECTS (subprog_decl) = TYPE_VOLATILE (subprog_type);
1662 DECL_ARGUMENTS (subprog_decl) = param_decl_list;
1663 DECL_RESULT (subprog_decl) = build_decl (RESULT_DECL, 0, return_type);
1664 DECL_ARTIFICIAL (DECL_RESULT (subprog_decl)) = 1;
1665 DECL_IGNORED_P (DECL_RESULT (subprog_decl)) = 1;
1668 DECL_DECLARED_INLINE_P (subprog_decl) = 1;
1671 SET_DECL_ASSEMBLER_NAME (subprog_decl, asm_name);
1673 process_attributes (subprog_decl, attr_list);
1675 /* Add this decl to the current binding level. */
1676 gnat_pushdecl (subprog_decl, gnat_node);
1678 /* Output the assembler code and/or RTL for the declaration. */
1679 rest_of_decl_compilation (subprog_decl, global_bindings_p (), 0);
1681 return subprog_decl;
1684 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
1685 body. This routine needs to be invoked before processing the declarations
1686 appearing in the subprogram. */
1689 begin_subprog_body (tree subprog_decl)
1693 current_function_decl = subprog_decl;
1694 announce_function (subprog_decl);
1696 /* Enter a new binding level and show that all the parameters belong to
1699 for (param_decl = DECL_ARGUMENTS (subprog_decl); param_decl;
1700 param_decl = TREE_CHAIN (param_decl))
1701 DECL_CONTEXT (param_decl) = subprog_decl;
1703 make_decl_rtl (subprog_decl);
1705 /* We handle pending sizes via the elaboration of types, so we don't need to
1706 save them. This causes them to be marked as part of the outer function
1707 and then discarded. */
1708 get_pending_sizes ();
1711 /* Finish the definition of the current subprogram and compile it all the way
1712 to assembler language output. BODY is the tree corresponding to
1716 end_subprog_body (tree body)
1718 tree fndecl = current_function_decl;
1720 /* Mark the BLOCK for this level as being for this function and pop the
1721 level. Since the vars in it are the parameters, clear them. */
1722 BLOCK_VARS (current_binding_level->block) = 0;
1723 BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl;
1724 DECL_INITIAL (fndecl) = current_binding_level->block;
1727 /* Deal with inline. If declared inline or we should default to inline,
1728 set the flag in the decl. */
1729 DECL_INLINE (fndecl)
1730 = DECL_DECLARED_INLINE_P (fndecl) || flag_inline_trees == 2;
1732 /* We handle pending sizes via the elaboration of types, so we don't
1733 need to save them. */
1734 get_pending_sizes ();
1736 /* Mark the RESULT_DECL as being in this subprogram. */
1737 DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl;
1739 DECL_SAVED_TREE (fndecl) = body;
1741 current_function_decl = DECL_CONTEXT (fndecl);
1744 /* If we're only annotating types, don't actually compile this function. */
1745 if (type_annotate_only)
1748 /* If we don't have .ctors/.dtors sections, and this is a static
1749 constructor or destructor, it must be recorded now. */
1750 if (DECL_STATIC_CONSTRUCTOR (fndecl) && !targetm.have_ctors_dtors)
1751 static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors);
1753 if (DECL_STATIC_DESTRUCTOR (fndecl) && !targetm.have_ctors_dtors)
1754 static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors);
1756 /* We do different things for nested and non-nested functions.
1757 ??? This should be in cgraph. */
1758 if (!DECL_CONTEXT (fndecl))
1760 gnat_gimplify_function (fndecl);
1761 cgraph_finalize_function (fndecl, false);
1764 /* Register this function with cgraph just far enough to get it
1765 added to our parent's nested function list. */
1766 (void) cgraph_node (fndecl);
1769 /* Convert FNDECL's code to GIMPLE and handle any nested functions. */
1772 gnat_gimplify_function (tree fndecl)
1774 struct cgraph_node *cgn;
1776 dump_function (TDI_original, fndecl);
1777 gimplify_function_tree (fndecl);
1778 dump_function (TDI_generic, fndecl);
1780 /* Convert all nested functions to GIMPLE now. We do things in this order
1781 so that items like VLA sizes are expanded properly in the context of the
1782 correct function. */
1783 cgn = cgraph_node (fndecl);
1784 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
1785 gnat_gimplify_function (cgn->decl);
1788 /* Return a definition for a builtin function named NAME and whose data type
1789 is TYPE. TYPE should be a function type with argument types.
1790 FUNCTION_CODE tells later passes how to compile calls to this function.
1791 See tree.h for its possible values.
1793 If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME,
1794 the name to be called if we can't opencode the function. If
1795 ATTRS is nonzero, use that for the function attribute list. */
1798 builtin_function (const char *name, tree type, int function_code,
1799 enum built_in_class class, const char *library_name,
1802 tree decl = build_decl (FUNCTION_DECL, get_identifier (name), type);
1804 DECL_EXTERNAL (decl) = 1;
1805 TREE_PUBLIC (decl) = 1;
1807 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name));
1809 gnat_pushdecl (decl, Empty);
1810 DECL_BUILT_IN_CLASS (decl) = class;
1811 DECL_FUNCTION_CODE (decl) = function_code;
1813 decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
1817 /* Return an integer type with the number of bits of precision given by
1818 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
1819 it is a signed type. */
1822 gnat_type_for_size (unsigned precision, int unsignedp)
1827 if (precision <= 2 * MAX_BITS_PER_WORD
1828 && signed_and_unsigned_types[precision][unsignedp])
1829 return signed_and_unsigned_types[precision][unsignedp];
1832 t = make_unsigned_type (precision);
1834 t = make_signed_type (precision);
1836 if (precision <= 2 * MAX_BITS_PER_WORD)
1837 signed_and_unsigned_types[precision][unsignedp] = t;
1841 sprintf (type_name, "%sSIGNED_%d", unsignedp ? "UN" : "", precision);
1842 TYPE_NAME (t) = get_identifier (type_name);
1848 /* Likewise for floating-point types. */
1851 float_type_for_precision (int precision, enum machine_mode mode)
1856 if (float_types[(int) mode])
1857 return float_types[(int) mode];
1859 float_types[(int) mode] = t = make_node (REAL_TYPE);
1860 TYPE_PRECISION (t) = precision;
1863 gcc_assert (TYPE_MODE (t) == mode);
1866 sprintf (type_name, "FLOAT_%d", precision);
1867 TYPE_NAME (t) = get_identifier (type_name);
1873 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
1874 an unsigned type; otherwise a signed type is returned. */
1877 gnat_type_for_mode (enum machine_mode mode, int unsignedp)
1879 if (mode == BLKmode)
1881 else if (mode == VOIDmode)
1882 return void_type_node;
1883 else if (COMPLEX_MODE_P (mode))
1885 else if (SCALAR_FLOAT_MODE_P (mode))
1886 return float_type_for_precision (GET_MODE_PRECISION (mode), mode);
1887 else if (SCALAR_INT_MODE_P (mode))
1888 return gnat_type_for_size (GET_MODE_BITSIZE (mode), unsignedp);
1893 /* Return the unsigned version of a TYPE_NODE, a scalar type. */
1896 gnat_unsigned_type (tree type_node)
1898 tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 1);
1900 if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
1902 type = copy_node (type);
1903 TREE_TYPE (type) = type_node;
1905 else if (TREE_TYPE (type_node)
1906 && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
1907 && TYPE_MODULAR_P (TREE_TYPE (type_node)))
1909 type = copy_node (type);
1910 TREE_TYPE (type) = TREE_TYPE (type_node);
1916 /* Return the signed version of a TYPE_NODE, a scalar type. */
1919 gnat_signed_type (tree type_node)
1921 tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 0);
1923 if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
1925 type = copy_node (type);
1926 TREE_TYPE (type) = type_node;
1928 else if (TREE_TYPE (type_node)
1929 && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
1930 && TYPE_MODULAR_P (TREE_TYPE (type_node)))
1932 type = copy_node (type);
1933 TREE_TYPE (type) = TREE_TYPE (type_node);
1939 /* Return a type the same as TYPE except unsigned or signed according to
1943 gnat_signed_or_unsigned_type (int unsignedp, tree type)
1945 if (!INTEGRAL_TYPE_P (type) || TYPE_UNSIGNED (type) == unsignedp)
1948 return gnat_type_for_size (TYPE_PRECISION (type), unsignedp);
1951 /* EXP is an expression for the size of an object. If this size contains
1952 discriminant references, replace them with the maximum (if MAX_P) or
1953 minimum (if !MAX_P) possible value of the discriminant. */
1956 max_size (tree exp, bool max_p)
1958 enum tree_code code = TREE_CODE (exp);
1959 tree type = TREE_TYPE (exp);
1961 switch (TREE_CODE_CLASS (code))
1963 case tcc_declaration:
1967 case tcc_exceptional:
1968 if (code == TREE_LIST)
1969 return tree_cons (TREE_PURPOSE (exp),
1970 max_size (TREE_VALUE (exp), max_p),
1972 ? max_size (TREE_CHAIN (exp), max_p) : NULL_TREE);
1976 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
1977 modify. Otherwise, we treat it like a variable. */
1978 if (!CONTAINS_PLACEHOLDER_P (exp))
1981 type = TREE_TYPE (TREE_OPERAND (exp, 1));
1983 max_size (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type), true);
1985 case tcc_comparison:
1986 return max_p ? size_one_node : size_zero_node;
1990 case tcc_expression:
1991 switch (TREE_CODE_LENGTH (code))
1994 if (code == NON_LVALUE_EXPR)
1995 return max_size (TREE_OPERAND (exp, 0), max_p);
1998 fold (build1 (code, type,
1999 max_size (TREE_OPERAND (exp, 0),
2000 code == NEGATE_EXPR ? !max_p : max_p)));
2003 if (code == COMPOUND_EXPR)
2004 return max_size (TREE_OPERAND (exp, 1), max_p);
2007 tree lhs = max_size (TREE_OPERAND (exp, 0), max_p);
2008 tree rhs = max_size (TREE_OPERAND (exp, 1),
2009 code == MINUS_EXPR ? !max_p : max_p);
2011 /* Special-case wanting the maximum value of a MIN_EXPR.
2012 In that case, if one side overflows, return the other.
2013 sizetype is signed, but we know sizes are non-negative.
2014 Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
2015 overflowing or the maximum possible value and the RHS
2017 if (max_p && code == MIN_EXPR && TREE_OVERFLOW (rhs))
2019 else if (max_p && code == MIN_EXPR && TREE_OVERFLOW (lhs))
2021 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
2022 && ((TREE_CONSTANT (lhs) && TREE_OVERFLOW (lhs))
2023 || operand_equal_p (lhs, TYPE_MAX_VALUE (type), 0))
2024 && !TREE_CONSTANT (rhs))
2027 return fold (build2 (code, type, lhs, rhs));
2031 if (code == SAVE_EXPR)
2033 else if (code == COND_EXPR)
2034 return fold (build2 (max_p ? MAX_EXPR : MIN_EXPR, type,
2035 max_size (TREE_OPERAND (exp, 1), max_p),
2036 max_size (TREE_OPERAND (exp, 2), max_p)));
2037 else if (code == CALL_EXPR && TREE_OPERAND (exp, 1))
2038 return build3 (CALL_EXPR, type, TREE_OPERAND (exp, 0),
2039 max_size (TREE_OPERAND (exp, 1), max_p), NULL);
2042 /* Other tree classes cannot happen. */
2050 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
2051 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
2052 Return a constructor for the template. */
2055 build_template (tree template_type, tree array_type, tree expr)
2057 tree template_elts = NULL_TREE;
2058 tree bound_list = NULL_TREE;
2061 if (TREE_CODE (array_type) == RECORD_TYPE
2062 && (TYPE_IS_PADDING_P (array_type)
2063 || TYPE_JUSTIFIED_MODULAR_P (array_type)))
2064 array_type = TREE_TYPE (TYPE_FIELDS (array_type));
2066 if (TREE_CODE (array_type) == ARRAY_TYPE
2067 || (TREE_CODE (array_type) == INTEGER_TYPE
2068 && TYPE_HAS_ACTUAL_BOUNDS_P (array_type)))
2069 bound_list = TYPE_ACTUAL_BOUNDS (array_type);
2071 /* First make the list for a CONSTRUCTOR for the template. Go down the
2072 field list of the template instead of the type chain because this
2073 array might be an Ada array of arrays and we can't tell where the
2074 nested arrays stop being the underlying object. */
2076 for (field = TYPE_FIELDS (template_type); field;
2078 ? (bound_list = TREE_CHAIN (bound_list))
2079 : (array_type = TREE_TYPE (array_type))),
2080 field = TREE_CHAIN (TREE_CHAIN (field)))
2082 tree bounds, min, max;
2084 /* If we have a bound list, get the bounds from there. Likewise
2085 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
2086 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
2087 This will give us a maximum range. */
2089 bounds = TREE_VALUE (bound_list);
2090 else if (TREE_CODE (array_type) == ARRAY_TYPE)
2091 bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type));
2092 else if (expr && TREE_CODE (expr) == PARM_DECL
2093 && DECL_BY_COMPONENT_PTR_P (expr))
2094 bounds = TREE_TYPE (field);
2098 min = convert (TREE_TYPE (TREE_CHAIN (field)), TYPE_MIN_VALUE (bounds));
2099 max = convert (TREE_TYPE (field), TYPE_MAX_VALUE (bounds));
2101 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
2102 substitute it from OBJECT. */
2103 min = SUBSTITUTE_PLACEHOLDER_IN_EXPR (min, expr);
2104 max = SUBSTITUTE_PLACEHOLDER_IN_EXPR (max, expr);
2106 template_elts = tree_cons (TREE_CHAIN (field), max,
2107 tree_cons (field, min, template_elts));
2110 return gnat_build_constructor (template_type, nreverse (template_elts));
2113 /* Build a VMS descriptor from a Mechanism_Type, which must specify
2114 a descriptor type, and the GCC type of an object. Each FIELD_DECL
2115 in the type contains in its DECL_INITIAL the expression to use when
2116 a constructor is made for the type. GNAT_ENTITY is an entity used
2117 to print out an error message if the mechanism cannot be applied to
2118 an object of that type and also for the name. */
2121 build_vms_descriptor (tree type, Mechanism_Type mech, Entity_Id gnat_entity)
2123 tree record_type = make_node (RECORD_TYPE);
2124 tree field_list = 0;
2133 /* If TYPE is an unconstrained array, use the underlying array type. */
2134 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
2135 type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type))));
2137 /* If this is an array, compute the number of dimensions in the array,
2138 get the index types, and point to the inner type. */
2139 if (TREE_CODE (type) != ARRAY_TYPE)
2142 for (ndim = 1, inner_type = type;
2143 TREE_CODE (TREE_TYPE (inner_type)) == ARRAY_TYPE
2144 && TYPE_MULTI_ARRAY_P (TREE_TYPE (inner_type));
2145 ndim++, inner_type = TREE_TYPE (inner_type))
2148 idx_arr = (tree *) alloca (ndim * sizeof (tree));
2150 if (mech != By_Descriptor_NCA
2151 && TREE_CODE (type) == ARRAY_TYPE && TYPE_CONVENTION_FORTRAN_P (type))
2152 for (i = ndim - 1, inner_type = type;
2154 i--, inner_type = TREE_TYPE (inner_type))
2155 idx_arr[i] = TYPE_DOMAIN (inner_type);
2157 for (i = 0, inner_type = type;
2159 i++, inner_type = TREE_TYPE (inner_type))
2160 idx_arr[i] = TYPE_DOMAIN (inner_type);
2162 /* Now get the DTYPE value. */
2163 switch (TREE_CODE (type))
2167 if (TYPE_VAX_FLOATING_POINT_P (type))
2168 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2181 switch (GET_MODE_BITSIZE (TYPE_MODE (type)))
2184 dtype = TYPE_UNSIGNED (type) ? 2 : 6;
2187 dtype = TYPE_UNSIGNED (type) ? 3 : 7;
2190 dtype = TYPE_UNSIGNED (type) ? 4 : 8;
2193 dtype = TYPE_UNSIGNED (type) ? 5 : 9;
2196 dtype = TYPE_UNSIGNED (type) ? 25 : 26;
2202 dtype = GET_MODE_BITSIZE (TYPE_MODE (type)) == 32 ? 52 : 53;
2206 if (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE
2207 && TYPE_VAX_FLOATING_POINT_P (type))
2208 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2220 dtype = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) == 32 ? 54: 55;
2231 /* Get the CLASS value. */
2234 case By_Descriptor_A:
2237 case By_Descriptor_NCA:
2240 case By_Descriptor_SB:
2247 /* Make the type for a descriptor for VMS. The first four fields
2248 are the same for all types. */
2251 = chainon (field_list,
2252 make_descriptor_field
2253 ("LENGTH", gnat_type_for_size (16, 1), record_type,
2254 size_in_bytes (mech == By_Descriptor_A ? inner_type : type)));
2256 field_list = chainon (field_list,
2257 make_descriptor_field ("DTYPE",
2258 gnat_type_for_size (8, 1),
2259 record_type, size_int (dtype)));
2260 field_list = chainon (field_list,
2261 make_descriptor_field ("CLASS",
2262 gnat_type_for_size (8, 1),
2263 record_type, size_int (class)));
2266 = chainon (field_list,
2267 make_descriptor_field
2269 build_pointer_type_for_mode (type, SImode, false), record_type,
2271 build_pointer_type_for_mode (type, SImode, false),
2272 build0 (PLACEHOLDER_EXPR, type))));
2277 case By_Descriptor_S:
2280 case By_Descriptor_SB:
2282 = chainon (field_list,
2283 make_descriptor_field
2284 ("SB_L1", gnat_type_for_size (32, 1), record_type,
2285 TREE_CODE (type) == ARRAY_TYPE
2286 ? TYPE_MIN_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2288 = chainon (field_list,
2289 make_descriptor_field
2290 ("SB_L2", gnat_type_for_size (32, 1), record_type,
2291 TREE_CODE (type) == ARRAY_TYPE
2292 ? TYPE_MAX_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2295 case By_Descriptor_A:
2296 case By_Descriptor_NCA:
2297 field_list = chainon (field_list,
2298 make_descriptor_field ("SCALE",
2299 gnat_type_for_size (8, 1),
2303 field_list = chainon (field_list,
2304 make_descriptor_field ("DIGITS",
2305 gnat_type_for_size (8, 1),
2310 = chainon (field_list,
2311 make_descriptor_field
2312 ("AFLAGS", gnat_type_for_size (8, 1), record_type,
2313 size_int (mech == By_Descriptor_NCA
2315 /* Set FL_COLUMN, FL_COEFF, and FL_BOUNDS. */
2316 : (TREE_CODE (type) == ARRAY_TYPE
2317 && TYPE_CONVENTION_FORTRAN_P (type)
2320 field_list = chainon (field_list,
2321 make_descriptor_field ("DIMCT",
2322 gnat_type_for_size (8, 1),
2326 field_list = chainon (field_list,
2327 make_descriptor_field ("ARSIZE",
2328 gnat_type_for_size (32, 1),
2330 size_in_bytes (type)));
2332 /* Now build a pointer to the 0,0,0... element. */
2333 tem = build0 (PLACEHOLDER_EXPR, type);
2334 for (i = 0, inner_type = type; i < ndim;
2335 i++, inner_type = TREE_TYPE (inner_type))
2336 tem = build4 (ARRAY_REF, TREE_TYPE (inner_type), tem,
2337 convert (TYPE_DOMAIN (inner_type), size_zero_node),
2338 NULL_TREE, NULL_TREE);
2341 = chainon (field_list,
2342 make_descriptor_field
2344 build_pointer_type_for_mode (inner_type, SImode, false),
2347 build_pointer_type_for_mode (inner_type, SImode,
2351 /* Next come the addressing coefficients. */
2353 for (i = 0; i < ndim; i++)
2357 = size_binop (MULT_EXPR, tem,
2358 size_binop (PLUS_EXPR,
2359 size_binop (MINUS_EXPR,
2360 TYPE_MAX_VALUE (idx_arr[i]),
2361 TYPE_MIN_VALUE (idx_arr[i])),
2364 fname[0] = (mech == By_Descriptor_NCA ? 'S' : 'M');
2365 fname[1] = '0' + i, fname[2] = 0;
2367 = chainon (field_list,
2368 make_descriptor_field (fname,
2369 gnat_type_for_size (32, 1),
2370 record_type, idx_length));
2372 if (mech == By_Descriptor_NCA)
2376 /* Finally here are the bounds. */
2377 for (i = 0; i < ndim; i++)
2381 fname[0] = 'L', fname[1] = '0' + i, fname[2] = 0;
2383 = chainon (field_list,
2384 make_descriptor_field
2385 (fname, gnat_type_for_size (32, 1), record_type,
2386 TYPE_MIN_VALUE (idx_arr[i])));
2390 = chainon (field_list,
2391 make_descriptor_field
2392 (fname, gnat_type_for_size (32, 1), record_type,
2393 TYPE_MAX_VALUE (idx_arr[i])));
2398 post_error ("unsupported descriptor type for &", gnat_entity);
2401 finish_record_type (record_type, field_list, false, true);
2402 create_type_decl (create_concat_name (gnat_entity, "DESC"), record_type,
2403 NULL, true, false, gnat_entity);
2408 /* Utility routine for above code to make a field. */
2411 make_descriptor_field (const char *name, tree type,
2412 tree rec_type, tree initial)
2415 = create_field_decl (get_identifier (name), type, rec_type, 0, 0, 0, 0);
2417 DECL_INITIAL (field) = initial;
2421 /* Build a type to be used to represent an aliased object whose nominal
2422 type is an unconstrained array. This consists of a RECORD_TYPE containing
2423 a field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an
2424 ARRAY_TYPE. If ARRAY_TYPE is that of the unconstrained array, this
2425 is used to represent an arbitrary unconstrained object. Use NAME
2426 as the name of the record. */
2429 build_unc_object_type (tree template_type, tree object_type, tree name)
2431 tree type = make_node (RECORD_TYPE);
2432 tree template_field = create_field_decl (get_identifier ("BOUNDS"),
2433 template_type, type, 0, 0, 0, 1);
2434 tree array_field = create_field_decl (get_identifier ("ARRAY"), object_type,
2437 TYPE_NAME (type) = name;
2438 TYPE_CONTAINS_TEMPLATE_P (type) = 1;
2439 finish_record_type (type,
2440 chainon (chainon (NULL_TREE, template_field),
2447 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE. In
2448 the normal case this is just two adjustments, but we have more to do
2449 if NEW is an UNCONSTRAINED_ARRAY_TYPE. */
2452 update_pointer_to (tree old_type, tree new_type)
2454 tree ptr = TYPE_POINTER_TO (old_type);
2455 tree ref = TYPE_REFERENCE_TO (old_type);
2459 /* If this is the main variant, process all the other variants first. */
2460 if (TYPE_MAIN_VARIANT (old_type) == old_type)
2461 for (type = TYPE_NEXT_VARIANT (old_type); type;
2462 type = TYPE_NEXT_VARIANT (type))
2463 update_pointer_to (type, new_type);
2465 /* If no pointer or reference, we are done. */
2469 /* Merge the old type qualifiers in the new type.
2471 Each old variant has qualifiers for specific reasons, and the new
2472 designated type as well. Each set of qualifiers represents useful
2473 information grabbed at some point, and merging the two simply unifies
2474 these inputs into the final type description.
2476 Consider for instance a volatile type frozen after an access to constant
2477 type designating it. After the designated type freeze, we get here with a
2478 volatile new_type and a dummy old_type with a readonly variant, created
2479 when the access type was processed. We shall make a volatile and readonly
2480 designated type, because that's what it really is.
2482 We might also get here for a non-dummy old_type variant with different
2483 qualifiers than the new_type ones, for instance in some cases of pointers
2484 to private record type elaboration (see the comments around the call to
2485 this routine from gnat_to_gnu_entity/E_Access_Type). We have to merge the
2486 qualifiers in thoses cases too, to avoid accidentally discarding the
2487 initial set, and will often end up with old_type == new_type then. */
2488 new_type = build_qualified_type (new_type,
2489 TYPE_QUALS (old_type)
2490 | TYPE_QUALS (new_type));
2492 /* If the new type and the old one are identical, there is nothing to
2494 if (old_type == new_type)
2497 /* Otherwise, first handle the simple case. */
2498 if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE)
2500 TYPE_POINTER_TO (new_type) = ptr;
2501 TYPE_REFERENCE_TO (new_type) = ref;
2503 for (; ptr; ptr = TYPE_NEXT_PTR_TO (ptr))
2504 for (ptr1 = TYPE_MAIN_VARIANT (ptr); ptr1;
2505 ptr1 = TYPE_NEXT_VARIANT (ptr1))
2506 TREE_TYPE (ptr1) = new_type;
2508 for (; ref; ref = TYPE_NEXT_REF_TO (ref))
2509 for (ref1 = TYPE_MAIN_VARIANT (ref); ref1;
2510 ref1 = TYPE_NEXT_VARIANT (ref1))
2511 TREE_TYPE (ref1) = new_type;
2514 /* Now deal with the unconstrained array case. In this case the "pointer"
2515 is actually a RECORD_TYPE where the types of both fields are
2516 pointers to void. In that case, copy the field list from the
2517 old type to the new one and update the fields' context. */
2518 else if (TREE_CODE (ptr) != RECORD_TYPE || !TYPE_IS_FAT_POINTER_P (ptr))
2523 tree new_obj_rec = TYPE_OBJECT_RECORD_TYPE (new_type);
2528 SET_DECL_ORIGINAL_FIELD (TYPE_FIELDS (ptr),
2529 TYPE_FIELDS (TYPE_POINTER_TO (new_type)));
2530 SET_DECL_ORIGINAL_FIELD (TREE_CHAIN (TYPE_FIELDS (ptr)),
2531 TREE_CHAIN (TYPE_FIELDS
2532 (TYPE_POINTER_TO (new_type))));
2534 TYPE_FIELDS (ptr) = TYPE_FIELDS (TYPE_POINTER_TO (new_type));
2535 DECL_CONTEXT (TYPE_FIELDS (ptr)) = ptr;
2536 DECL_CONTEXT (TREE_CHAIN (TYPE_FIELDS (ptr))) = ptr;
2538 /* Rework the PLACEHOLDER_EXPR inside the reference to the
2541 ??? This is now the only use of gnat_substitute_in_type, which
2542 is now a very "heavy" routine to do this, so it should be replaced
2544 ptr_temp_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (ptr)));
2545 new_ref = build3 (COMPONENT_REF, ptr_temp_type,
2546 build0 (PLACEHOLDER_EXPR, ptr),
2547 TREE_CHAIN (TYPE_FIELDS (ptr)), NULL_TREE);
2550 (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))),
2551 gnat_substitute_in_type (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))),
2552 TREE_CHAIN (TYPE_FIELDS (ptr)), new_ref));
2554 for (var = TYPE_MAIN_VARIANT (ptr); var; var = TYPE_NEXT_VARIANT (var))
2555 SET_TYPE_UNCONSTRAINED_ARRAY (var, new_type);
2557 TYPE_POINTER_TO (new_type) = TYPE_REFERENCE_TO (new_type)
2558 = TREE_TYPE (new_type) = ptr;
2560 /* Now handle updating the allocation record, what the thin pointer
2561 points to. Update all pointers from the old record into the new
2562 one, update the types of the fields, and recompute the size. */
2564 update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), new_obj_rec);
2566 TREE_TYPE (TYPE_FIELDS (new_obj_rec)) = TREE_TYPE (ptr_temp_type);
2567 TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
2568 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr)));
2569 DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
2570 = TYPE_SIZE (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))));
2571 DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
2572 = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))));
2574 TYPE_SIZE (new_obj_rec)
2575 = size_binop (PLUS_EXPR,
2576 DECL_SIZE (TYPE_FIELDS (new_obj_rec)),
2577 DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))));
2578 TYPE_SIZE_UNIT (new_obj_rec)
2579 = size_binop (PLUS_EXPR,
2580 DECL_SIZE_UNIT (TYPE_FIELDS (new_obj_rec)),
2581 DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))));
2582 rest_of_type_compilation (ptr, global_bindings_p ());
2586 /* Convert a pointer to a constrained array into a pointer to a fat
2587 pointer. This involves making or finding a template. */
2590 convert_to_fat_pointer (tree type, tree expr)
2592 tree template_type = TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type))));
2593 tree template, template_addr;
2594 tree etype = TREE_TYPE (expr);
2596 /* If EXPR is a constant of zero, we make a fat pointer that has a null
2597 pointer to the template and array. */
2598 if (integer_zerop (expr))
2600 gnat_build_constructor
2602 tree_cons (TYPE_FIELDS (type),
2603 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
2604 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
2605 convert (build_pointer_type (template_type),
2609 /* If EXPR is a thin pointer, make the template and data from the record. */
2611 else if (TYPE_THIN_POINTER_P (etype))
2613 tree fields = TYPE_FIELDS (TREE_TYPE (etype));
2615 expr = save_expr (expr);
2616 if (TREE_CODE (expr) == ADDR_EXPR)
2617 expr = TREE_OPERAND (expr, 0);
2619 expr = build1 (INDIRECT_REF, TREE_TYPE (etype), expr);
2621 template = build_component_ref (expr, NULL_TREE, fields, false);
2622 expr = build_unary_op (ADDR_EXPR, NULL_TREE,
2623 build_component_ref (expr, NULL_TREE,
2624 TREE_CHAIN (fields), false));
2627 /* Otherwise, build the constructor for the template. */
2628 template = build_template (template_type, TREE_TYPE (etype), expr);
2630 template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template);
2632 /* The result is a CONSTRUCTOR for the fat pointer.
2634 If expr is an argument of a foreign convention subprogram, the type it
2635 points to is directly the component type. In this case, the expression
2636 type may not match the corresponding FIELD_DECL type at this point, so we
2637 call "convert" here to fix that up if necessary. This type consistency is
2638 required, for instance because it ensures that possible later folding of
2639 component_refs against this constructor always yields something of the
2640 same type as the initial reference.
2642 Note that the call to "build_template" above is still fine, because it
2643 will only refer to the provided template_type in this case. */
2645 gnat_build_constructor
2646 (type, tree_cons (TYPE_FIELDS (type),
2647 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
2648 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
2649 template_addr, NULL_TREE)));
2652 /* Convert to a thin pointer type, TYPE. The only thing we know how to convert
2653 is something that is a fat pointer, so convert to it first if it EXPR
2654 is not already a fat pointer. */
2657 convert_to_thin_pointer (tree type, tree expr)
2659 if (!TYPE_FAT_POINTER_P (TREE_TYPE (expr)))
2661 = convert_to_fat_pointer
2662 (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))), expr);
2664 /* We get the pointer to the data and use a NOP_EXPR to make it the
2666 expr = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (TREE_TYPE (expr)),
2668 expr = build1 (NOP_EXPR, type, expr);
2673 /* Create an expression whose value is that of EXPR,
2674 converted to type TYPE. The TREE_TYPE of the value
2675 is always TYPE. This function implements all reasonable
2676 conversions; callers should filter out those that are
2677 not permitted by the language being compiled. */
2680 convert (tree type, tree expr)
2682 enum tree_code code = TREE_CODE (type);
2683 tree etype = TREE_TYPE (expr);
2684 enum tree_code ecode = TREE_CODE (etype);
2687 /* If EXPR is already the right type, we are done. */
2691 /* If the input type has padding, remove it by doing a component reference
2692 to the field. If the output type has padding, make a constructor
2693 to build the record. If both input and output have padding and are
2694 of variable size, do this as an unchecked conversion. */
2695 else if (ecode == RECORD_TYPE && code == RECORD_TYPE
2696 && TYPE_IS_PADDING_P (type) && TYPE_IS_PADDING_P (etype)
2697 && (!TREE_CONSTANT (TYPE_SIZE (type))
2698 || !TREE_CONSTANT (TYPE_SIZE (etype))))
2700 else if (ecode == RECORD_TYPE && TYPE_IS_PADDING_P (etype))
2702 /* If we have just converted to this padded type, just get
2703 the inner expression. */
2704 if (TREE_CODE (expr) == CONSTRUCTOR
2705 && CONSTRUCTOR_ELTS (expr)
2706 && TREE_PURPOSE (CONSTRUCTOR_ELTS (expr)) == TYPE_FIELDS (etype))
2707 return TREE_VALUE (CONSTRUCTOR_ELTS (expr));
2709 return convert (type,
2710 build_component_ref (expr, NULL_TREE,
2711 TYPE_FIELDS (etype), false));
2713 else if (code == RECORD_TYPE && TYPE_IS_PADDING_P (type))
2715 /* If we previously converted from another type and our type is
2716 of variable size, remove the conversion to avoid the need for
2717 variable-size temporaries. */
2718 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
2719 && !TREE_CONSTANT (TYPE_SIZE (type)))
2720 expr = TREE_OPERAND (expr, 0);
2722 /* If we are just removing the padding from expr, convert the original
2723 object if we have variable size. That will avoid the need
2724 for some variable-size temporaries. */
2725 if (TREE_CODE (expr) == COMPONENT_REF
2726 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE
2727 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (expr, 0)))
2728 && !TREE_CONSTANT (TYPE_SIZE (type)))
2729 return convert (type, TREE_OPERAND (expr, 0));
2731 /* If the result type is a padded type with a self-referentially-sized
2732 field and the expression type is a record, do this as an
2733 unchecked conversion. */
2734 else if (TREE_CODE (etype) == RECORD_TYPE
2735 && CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type))))
2736 return unchecked_convert (type, expr, false);
2740 gnat_build_constructor (type,
2741 tree_cons (TYPE_FIELDS (type),
2743 (TYPE_FIELDS (type)),
2748 /* If the input is a biased type, adjust first. */
2749 if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype))
2750 return convert (type, fold (build2 (PLUS_EXPR, TREE_TYPE (etype),
2751 fold (build1 (NOP_EXPR,
2754 TYPE_MIN_VALUE (etype))));
2756 /* If the input is a justified modular type, we need to extract
2757 the actual object before converting it to any other type with the
2758 exception of an unconstrained array. */
2759 if (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)
2760 && code != UNCONSTRAINED_ARRAY_TYPE)
2761 return convert (type, build_component_ref (expr, NULL_TREE,
2762 TYPE_FIELDS (etype), false));
2764 /* If converting to a type that contains a template, convert to the data
2765 type and then build the template. */
2766 if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type))
2768 tree obj_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type)));
2770 /* If the source already has a template, get a reference to the
2771 associated array only, as we are going to rebuild a template
2772 for the target type anyway. */
2773 expr = maybe_unconstrained_array (expr);
2776 gnat_build_constructor
2778 tree_cons (TYPE_FIELDS (type),
2779 build_template (TREE_TYPE (TYPE_FIELDS (type)),
2780 obj_type, NULL_TREE),
2781 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
2782 convert (obj_type, expr), NULL_TREE)));
2785 /* There are some special cases of expressions that we process
2787 switch (TREE_CODE (expr))
2793 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
2794 conversion in gnat_expand_expr. NULL_EXPR does not represent
2795 and actual value, so no conversion is needed. */
2796 expr = copy_node (expr);
2797 TREE_TYPE (expr) = type;
2801 /* If we are converting a STRING_CST to another constrained array type,
2802 just make a new one in the proper type. */
2803 if (code == ecode && AGGREGATE_TYPE_P (etype)
2804 && !(TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST
2805 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
2806 && (TREE_CODE (expr) == STRING_CST
2807 || get_alias_set (etype) == get_alias_set (type)))
2809 expr = copy_node (expr);
2810 TREE_TYPE (expr) = type;
2815 case UNCONSTRAINED_ARRAY_REF:
2816 /* Convert this to the type of the inner array by getting the address of
2817 the array from the template. */
2818 expr = build_unary_op (INDIRECT_REF, NULL_TREE,
2819 build_component_ref (TREE_OPERAND (expr, 0),
2820 get_identifier ("P_ARRAY"),
2822 etype = TREE_TYPE (expr);
2823 ecode = TREE_CODE (etype);
2826 case VIEW_CONVERT_EXPR:
2827 if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype)
2828 && !TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
2829 return convert (type, TREE_OPERAND (expr, 0));
2833 /* If both types are record types, just convert the pointer and
2834 make a new INDIRECT_REF.
2836 ??? Disable this for now since it causes problems with the
2837 code in build_binary_op for MODIFY_EXPR which wants to
2838 strip off conversions. But that code really is a mess and
2839 we need to do this a much better way some time. */
2841 && (TREE_CODE (type) == RECORD_TYPE
2842 || TREE_CODE (type) == UNION_TYPE)
2843 && (TREE_CODE (etype) == RECORD_TYPE
2844 || TREE_CODE (etype) == UNION_TYPE)
2845 && !TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
2846 return build_unary_op (INDIRECT_REF, NULL_TREE,
2847 convert (build_pointer_type (type),
2848 TREE_OPERAND (expr, 0)));
2855 /* Check for converting to a pointer to an unconstrained array. */
2856 if (TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype))
2857 return convert_to_fat_pointer (type, expr);
2859 /* If we're converting between two aggregate types that have the same main
2860 variant, just make a VIEW_CONVER_EXPR. */
2861 else if (AGGREGATE_TYPE_P (type)
2862 && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype))
2863 return build1 (VIEW_CONVERT_EXPR, type, expr);
2865 /* In all other cases of related types, make a NOP_EXPR. */
2866 else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype)
2867 || (code == INTEGER_CST && ecode == INTEGER_CST
2868 && (type == TREE_TYPE (etype) || etype == TREE_TYPE (type))))
2869 return fold (build1 (NOP_EXPR, type, expr));
2874 return build1 (CONVERT_EXPR, type, expr);
2877 return fold (build1 (NOP_EXPR, type, gnat_truthvalue_conversion (expr)));
2880 if (TYPE_HAS_ACTUAL_BOUNDS_P (type)
2881 && (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE
2882 || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))))
2883 return unchecked_convert (type, expr, false);
2884 else if (TYPE_BIASED_REPRESENTATION_P (type))
2885 return fold (build1 (CONVERT_EXPR, type,
2886 fold (build2 (MINUS_EXPR, TREE_TYPE (type),
2887 convert (TREE_TYPE (type), expr),
2888 TYPE_MIN_VALUE (type)))));
2890 /* ... fall through ... */
2893 return fold (convert_to_integer (type, expr));
2896 case REFERENCE_TYPE:
2897 /* If converting between two pointers to records denoting
2898 both a template and type, adjust if needed to account
2899 for any differing offsets, since one might be negative. */
2900 if (TYPE_THIN_POINTER_P (etype) && TYPE_THIN_POINTER_P (type))
2903 = size_diffop (bit_position (TYPE_FIELDS (TREE_TYPE (etype))),
2904 bit_position (TYPE_FIELDS (TREE_TYPE (type))));
2905 tree byte_diff = size_binop (CEIL_DIV_EXPR, bit_diff,
2906 sbitsize_int (BITS_PER_UNIT));
2908 expr = build1 (NOP_EXPR, type, expr);
2909 TREE_CONSTANT (expr) = TREE_CONSTANT (TREE_OPERAND (expr, 0));
2910 if (integer_zerop (byte_diff))
2913 return build_binary_op (PLUS_EXPR, type, expr,
2914 fold (convert_to_pointer (type, byte_diff)));
2917 /* If converting to a thin pointer, handle specially. */
2918 if (TYPE_THIN_POINTER_P (type)
2919 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)))
2920 return convert_to_thin_pointer (type, expr);
2922 /* If converting fat pointer to normal pointer, get the pointer to the
2923 array and then convert it. */
2924 else if (TYPE_FAT_POINTER_P (etype))
2925 expr = build_component_ref (expr, get_identifier ("P_ARRAY"),
2928 return fold (convert_to_pointer (type, expr));
2931 return fold (convert_to_real (type, expr));
2934 if (TYPE_JUSTIFIED_MODULAR_P (type) && !AGGREGATE_TYPE_P (etype))
2936 gnat_build_constructor
2937 (type, tree_cons (TYPE_FIELDS (type),
2938 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
2941 /* ... fall through ... */
2944 /* In these cases, assume the front-end has validated the conversion.
2945 If the conversion is valid, it will be a bit-wise conversion, so
2946 it can be viewed as an unchecked conversion. */
2947 return unchecked_convert (type, expr, false);
2950 /* For unchecked unions, just validate that the type is indeed that of
2951 a field of the type. Then make the simple conversion. */
2952 if (TYPE_UNCHECKED_UNION_P (type))
2954 for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem))
2956 if (TREE_TYPE (tem) == etype)
2957 return build1 (CONVERT_EXPR, type, expr);
2959 /* Accept slight type variations. */
2960 if (TREE_TYPE (tem) == TYPE_MAIN_VARIANT (etype)
2961 || (TREE_CODE (TREE_TYPE (tem)) == RECORD_TYPE
2962 && (TYPE_JUSTIFIED_MODULAR_P (TREE_TYPE (tem))
2963 || TYPE_IS_PADDING_P (TREE_TYPE (tem)))
2964 && TREE_TYPE (TYPE_FIELDS (TREE_TYPE (tem))) == etype))
2965 return build1 (CONVERT_EXPR, type,
2966 convert (TREE_TYPE (tem), expr));
2972 /* Otherwise, this is a conversion between a tagged type and some
2973 subtype, which we have to mark as a UNION_TYPE because of
2974 overlapping fields. */
2975 return unchecked_convert (type, expr, false);
2977 case UNCONSTRAINED_ARRAY_TYPE:
2978 /* If EXPR is a constrained array, take its address, convert it to a
2979 fat pointer, and then dereference it. Likewise if EXPR is a
2980 record containing both a template and a constrained array.
2981 Note that a record representing a justified modular type
2982 always represents a packed constrained array. */
2983 if (ecode == ARRAY_TYPE
2984 || (ecode == INTEGER_TYPE && TYPE_HAS_ACTUAL_BOUNDS_P (etype))
2985 || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))
2986 || (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype)))
2989 (INDIRECT_REF, NULL_TREE,
2990 convert_to_fat_pointer (TREE_TYPE (type),
2991 build_unary_op (ADDR_EXPR,
2994 /* Do something very similar for converting one unconstrained
2995 array to another. */
2996 else if (ecode == UNCONSTRAINED_ARRAY_TYPE)
2998 build_unary_op (INDIRECT_REF, NULL_TREE,
2999 convert (TREE_TYPE (type),
3000 build_unary_op (ADDR_EXPR,
3006 return fold (convert_to_complex (type, expr));
3013 /* Remove all conversions that are done in EXP. This includes converting
3014 from a padded type or to a justified modular type. If TRUE_ADDRESS
3015 is true, always return the address of the containing object even if
3016 the address is not bit-aligned. */
3019 remove_conversions (tree exp, bool true_address)
3021 switch (TREE_CODE (exp))
3025 && TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
3026 && TYPE_JUSTIFIED_MODULAR_P (TREE_TYPE (exp)))
3027 return remove_conversions (TREE_VALUE (CONSTRUCTOR_ELTS (exp)), true);
3031 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == RECORD_TYPE
3032 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
3033 return remove_conversions (TREE_OPERAND (exp, 0), true_address);
3036 case VIEW_CONVERT_EXPR: case NON_LVALUE_EXPR:
3037 case NOP_EXPR: case CONVERT_EXPR:
3038 return remove_conversions (TREE_OPERAND (exp, 0), true_address);
3047 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
3048 refers to the underlying array. If its type has TYPE_CONTAINS_TEMPLATE_P,
3049 likewise return an expression pointing to the underlying array. */
3052 maybe_unconstrained_array (tree exp)
3054 enum tree_code code = TREE_CODE (exp);
3057 switch (TREE_CODE (TREE_TYPE (exp)))
3059 case UNCONSTRAINED_ARRAY_TYPE:
3060 if (code == UNCONSTRAINED_ARRAY_REF)
3063 = build_unary_op (INDIRECT_REF, NULL_TREE,
3064 build_component_ref (TREE_OPERAND (exp, 0),
3065 get_identifier ("P_ARRAY"),
3067 TREE_READONLY (new) = TREE_STATIC (new) = TREE_READONLY (exp);
3071 else if (code == NULL_EXPR)
3072 return build1 (NULL_EXPR,
3073 TREE_TYPE (TREE_TYPE (TYPE_FIELDS
3074 (TREE_TYPE (TREE_TYPE (exp))))),
3075 TREE_OPERAND (exp, 0));
3078 /* If this is a padded type, convert to the unpadded type and see if
3079 it contains a template. */
3080 if (TYPE_IS_PADDING_P (TREE_TYPE (exp)))
3082 new = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (exp))), exp);
3083 if (TREE_CODE (TREE_TYPE (new)) == RECORD_TYPE
3084 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (new)))
3086 build_component_ref (new, NULL_TREE,
3087 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new))),
3090 else if (TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (exp)))
3092 build_component_ref (exp, NULL_TREE,
3093 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (exp))), 0);
3103 /* Return an expression that does an unchecked conversion of EXPR to TYPE.
3104 If NOTRUNC_P is true, truncation operations should be suppressed. */
3107 unchecked_convert (tree type, tree expr, bool notrunc_p)
3109 tree etype = TREE_TYPE (expr);
3111 /* If the expression is already the right type, we are done. */
3115 /* If both types types are integral just do a normal conversion.
3116 Likewise for a conversion to an unconstrained array. */
3117 if ((((INTEGRAL_TYPE_P (type)
3118 && !(TREE_CODE (type) == INTEGER_TYPE
3119 && TYPE_VAX_FLOATING_POINT_P (type)))
3120 || (POINTER_TYPE_P (type) && ! TYPE_THIN_POINTER_P (type))
3121 || (TREE_CODE (type) == RECORD_TYPE
3122 && TYPE_JUSTIFIED_MODULAR_P (type)))
3123 && ((INTEGRAL_TYPE_P (etype)
3124 && !(TREE_CODE (etype) == INTEGER_TYPE
3125 && TYPE_VAX_FLOATING_POINT_P (etype)))
3126 || (POINTER_TYPE_P (etype) && !TYPE_THIN_POINTER_P (etype))
3127 || (TREE_CODE (etype) == RECORD_TYPE
3128 && TYPE_JUSTIFIED_MODULAR_P (etype))))
3129 || TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
3133 if (TREE_CODE (etype) == INTEGER_TYPE
3134 && TYPE_BIASED_REPRESENTATION_P (etype))
3136 tree ntype = copy_type (etype);
3138 TYPE_BIASED_REPRESENTATION_P (ntype) = 0;
3139 TYPE_MAIN_VARIANT (ntype) = ntype;
3140 expr = build1 (NOP_EXPR, ntype, expr);
3143 if (TREE_CODE (type) == INTEGER_TYPE
3144 && TYPE_BIASED_REPRESENTATION_P (type))
3146 rtype = copy_type (type);
3147 TYPE_BIASED_REPRESENTATION_P (rtype) = 0;
3148 TYPE_MAIN_VARIANT (rtype) = rtype;
3151 expr = convert (rtype, expr);
3153 expr = build1 (NOP_EXPR, type, expr);
3156 /* If we are converting TO an integral type whose precision is not the
3157 same as its size, first unchecked convert to a record that contains
3158 an object of the output type. Then extract the field. */
3159 else if (INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type)
3160 && 0 != compare_tree_int (TYPE_RM_SIZE (type),
3161 GET_MODE_BITSIZE (TYPE_MODE (type))))
3163 tree rec_type = make_node (RECORD_TYPE);
3164 tree field = create_field_decl (get_identifier ("OBJ"), type,
3165 rec_type, 1, 0, 0, 0);
3167 TYPE_FIELDS (rec_type) = field;
3168 layout_type (rec_type);
3170 expr = unchecked_convert (rec_type, expr, notrunc_p);
3171 expr = build_component_ref (expr, NULL_TREE, field, 0);
3174 /* Similarly for integral input type whose precision is not equal to its
3176 else if (INTEGRAL_TYPE_P (etype) && TYPE_RM_SIZE (etype)
3177 && 0 != compare_tree_int (TYPE_RM_SIZE (etype),
3178 GET_MODE_BITSIZE (TYPE_MODE (etype))))
3180 tree rec_type = make_node (RECORD_TYPE);
3182 = create_field_decl (get_identifier ("OBJ"), etype, rec_type,
3185 TYPE_FIELDS (rec_type) = field;
3186 layout_type (rec_type);
3188 expr = gnat_build_constructor (rec_type, build_tree_list (field, expr));
3189 expr = unchecked_convert (type, expr, notrunc_p);
3192 /* We have a special case when we are converting between two
3193 unconstrained array types. In that case, take the address,
3194 convert the fat pointer types, and dereference. */
3195 else if (TREE_CODE (etype) == UNCONSTRAINED_ARRAY_TYPE
3196 && TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
3197 expr = build_unary_op (INDIRECT_REF, NULL_TREE,
3198 build1 (VIEW_CONVERT_EXPR, TREE_TYPE (type),
3199 build_unary_op (ADDR_EXPR, NULL_TREE,
3203 expr = maybe_unconstrained_array (expr);
3205 /* There's no point in doing two unchecked conversions in a row. */
3206 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR)
3207 expr = TREE_OPERAND (expr, 0);
3209 etype = TREE_TYPE (expr);
3210 expr = build1 (VIEW_CONVERT_EXPR, type, expr);
3213 /* If the result is an integral type whose size is not equal to
3214 the size of the underlying machine type, sign- or zero-extend
3215 the result. We need not do this in the case where the input is
3216 an integral type of the same precision and signedness or if the output
3217 is a biased type or if both the input and output are unsigned. */
3219 && INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type)
3220 && !(TREE_CODE (type) == INTEGER_TYPE
3221 && TYPE_BIASED_REPRESENTATION_P (type))
3222 && 0 != compare_tree_int (TYPE_RM_SIZE (type),
3223 GET_MODE_BITSIZE (TYPE_MODE (type)))
3224 && !(INTEGRAL_TYPE_P (etype)
3225 && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (etype)
3226 && operand_equal_p (TYPE_RM_SIZE (type),
3227 (TYPE_RM_SIZE (etype) != 0
3228 ? TYPE_RM_SIZE (etype) : TYPE_SIZE (etype)),
3230 && !(TYPE_UNSIGNED (type) && TYPE_UNSIGNED (etype)))
3232 tree base_type = gnat_type_for_mode (TYPE_MODE (type),
3233 TYPE_UNSIGNED (type));
3235 = convert (base_type,
3236 size_binop (MINUS_EXPR,
3238 (GET_MODE_BITSIZE (TYPE_MODE (type))),
3239 TYPE_RM_SIZE (type)));
3242 build_binary_op (RSHIFT_EXPR, base_type,
3243 build_binary_op (LSHIFT_EXPR, base_type,
3244 convert (base_type, expr),
3249 /* An unchecked conversion should never raise Constraint_Error. The code
3250 below assumes that GCC's conversion routines overflow the same way that
3251 the underlying hardware does. This is probably true. In the rare case
3252 when it is false, we can rely on the fact that such conversions are
3253 erroneous anyway. */
3254 if (TREE_CODE (expr) == INTEGER_CST)
3255 TREE_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (expr) = 0;
3257 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
3258 show no longer constant. */
3259 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
3260 && !operand_equal_p (TYPE_SIZE_UNIT (type), TYPE_SIZE_UNIT (etype),
3262 TREE_CONSTANT (expr) = 0;
3267 /* Search the chain of currently reachable declarations for a builtin
3268 FUNCTION_DECL node corresponding to function NAME (an IDENTIFIER_NODE).
3269 Return the first node found, if any, or NULL_TREE otherwise. */
3272 builtin_decl_for (tree name __attribute__ ((unused)))
3274 /* ??? not clear yet how to implement this function in tree-ssa, so
3275 return NULL_TREE for now */
3279 #include "gt-ada-utils.h"
3280 #include "gtype-ada.h"