1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2004, 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, 59 Temple Place - Suite 330, Boston, *
20 * MA 02111-1307, 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"
55 #ifndef MAX_FIXED_MODE_SIZE
56 #define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode)
59 #ifndef MAX_BITS_PER_WORD
60 #define MAX_BITS_PER_WORD BITS_PER_WORD
63 /* If nonzero, pretend we are allocating at global level. */
66 /* Tree nodes for the various types and decls we create. */
67 tree gnat_std_decls[(int) ADT_LAST];
69 /* Functions to call for each of the possible raise reasons. */
70 tree gnat_raise_decls[(int) LAST_REASON_CODE + 1];
72 /* Associates a GNAT tree node to a GCC tree node. It is used in
73 `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation
74 of `save_gnu_tree' for more info. */
75 static GTY((length ("max_gnat_nodes"))) tree *associate_gnat_to_gnu;
77 /* This listhead is used to record any global objects that need elaboration.
78 TREE_PURPOSE is the variable to be elaborated and TREE_VALUE is the
79 initial value to assign. */
81 static GTY(()) tree pending_elaborations;
83 /* This stack allows us to momentarily switch to generating elaboration
84 lists for an inner context. */
86 struct e_stack GTY(()) {
90 static GTY(()) struct e_stack *elist_stack;
92 /* This variable keeps a table for types for each precision so that we only
93 allocate each of them once. Signed and unsigned types are kept separate.
95 Note that these types are only used when fold-const requests something
96 special. Perhaps we should NOT share these types; we'll see how it
98 static GTY(()) tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2];
100 /* Likewise for float types, but record these by mode. */
101 static GTY(()) tree float_types[NUM_MACHINE_MODES];
103 /* For each binding contour we allocate a binding_level structure which records
104 the entities defined or declared in that contour. Contours include:
107 one for each subprogram definition
108 one for each compound statement (declare block)
110 Binding contours are used to create GCC tree BLOCK nodes. */
112 struct binding_level GTY(())
114 /* A chain of ..._DECL nodes for all variables, constants, functions,
115 parameters and type declarations. These ..._DECL nodes are chained
116 through the TREE_CHAIN field. Note that these ..._DECL nodes are stored
117 in the reverse of the order supplied to be compatible with the
120 /* For each level (except the global one), a chain of BLOCK nodes for all
121 the levels that were entered and exited one level down from this one. */
123 /* The BLOCK node for this level, if one has been preallocated.
124 If 0, the BLOCK is allocated (if needed) when the level is popped. */
126 /* The binding level containing this one (the enclosing binding level). */
127 struct binding_level *level_chain;
130 /* The binding level currently in effect. */
131 static GTY(()) struct binding_level *current_binding_level;
133 /* A chain of binding_level structures awaiting reuse. */
134 static GTY((deletable (""))) struct binding_level *free_binding_level;
136 /* The outermost binding level. This binding level is created when the
137 compiler is started and it will exist through the entire compilation. */
138 static struct binding_level *global_binding_level;
140 /* Binding level structures are initialized by copying this one. */
141 static struct binding_level clear_binding_level = {NULL, NULL, NULL, NULL};
143 struct language_function GTY(())
148 static tree merge_sizes (tree, tree, tree, int, int);
149 static tree compute_related_constant (tree, tree);
150 static tree split_plus (tree, tree *);
151 static int value_zerop (tree);
152 static tree float_type_for_precision (int, enum machine_mode);
153 static tree convert_to_fat_pointer (tree, tree);
154 static tree convert_to_thin_pointer (tree, tree);
155 static tree make_descriptor_field (const char *,tree, tree, tree);
156 static int value_factor_p (tree, int);
157 static int potential_alignment_gap (tree, tree, tree);
159 /* Initialize the association of GNAT nodes to GCC trees. */
162 init_gnat_to_gnu (void)
164 associate_gnat_to_gnu
165 = (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree));
167 pending_elaborations = build_tree_list (NULL_TREE, NULL_TREE);
170 /* GNAT_ENTITY is a GNAT tree node for an entity. GNU_DECL is the GCC tree
171 which is to be associated with GNAT_ENTITY. Such GCC tree node is always
172 a ..._DECL node. If NO_CHECK is nonzero, the latter check is suppressed.
174 If GNU_DECL is zero, a previous association is to be reset. */
177 save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl, int no_check)
179 /* Check that GNAT_ENTITY is not already defined and that it is being set
180 to something which is a decl. Raise gigi 401 if not. Usually, this
181 means GNAT_ENTITY is defined twice, but occasionally is due to some
184 && (associate_gnat_to_gnu[gnat_entity - First_Node_Id]
185 || (! no_check && ! DECL_P (gnu_decl))))
188 associate_gnat_to_gnu[gnat_entity - First_Node_Id] = gnu_decl;
191 /* GNAT_ENTITY is a GNAT tree node for a defining identifier.
192 Return the ..._DECL node that was associated with it. If there is no tree
193 node associated with GNAT_ENTITY, abort.
195 In some cases, such as delayed elaboration or expressions that need to
196 be elaborated only once, GNAT_ENTITY is really not an entity. */
199 get_gnu_tree (Entity_Id gnat_entity)
201 if (! associate_gnat_to_gnu[gnat_entity - First_Node_Id])
204 return associate_gnat_to_gnu[gnat_entity - First_Node_Id];
207 /* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */
210 present_gnu_tree (Entity_Id gnat_entity)
212 return (associate_gnat_to_gnu[gnat_entity - First_Node_Id] != NULL_TREE);
216 /* Return non-zero if we are currently in the global binding level. */
219 global_bindings_p (void)
221 return (force_global != 0 || current_binding_level == global_binding_level
225 /* Return the list of declarations in the current level. Note that this list
226 is in reverse order (it has to be so for back-end compatibility). */
231 return current_binding_level->names;
234 /* Nonzero if the current level needs to have a BLOCK made. */
239 return (current_binding_level->names != 0);
242 /* Enter a new binding level. The input parameter is ignored, but has to be
243 specified for back-end compatibility. */
246 pushlevel (int ignore ATTRIBUTE_UNUSED)
248 struct binding_level *newlevel = NULL;
250 /* Reuse a struct for this binding level, if there is one. */
251 if (free_binding_level)
253 newlevel = free_binding_level;
254 free_binding_level = free_binding_level->level_chain;
258 = (struct binding_level *) ggc_alloc (sizeof (struct binding_level));
260 *newlevel = clear_binding_level;
262 /* Add this level to the front of the chain (stack) of levels that are
264 newlevel->level_chain = current_binding_level;
265 current_binding_level = newlevel;
268 /* Exit a binding level.
269 Pop the level off, and restore the state of the identifier-decl mappings
270 that were in effect when this level was entered.
272 If KEEP is nonzero, this level had explicit declarations, so
273 and create a "block" (a BLOCK node) for the level
274 to record its declarations and subblocks for symbol table output.
276 If FUNCTIONBODY is nonzero, this level is the body of a function,
277 so create a block as if KEEP were set and also clear out all
280 If REVERSE is nonzero, reverse the order of decls before putting
281 them into the BLOCK. */
284 poplevel (int keep, int reverse, int functionbody)
286 /* Points to a GCC BLOCK tree node. This is the BLOCK node construted for the
287 binding level that we are about to exit and which is returned by this
289 tree block = NULL_TREE;
292 tree subblock_chain = current_binding_level->blocks;
294 int block_previously_created;
296 /* Reverse the list of XXXX_DECL nodes if desired. Note that the ..._DECL
297 nodes chained through the `names' field of current_binding_level are in
298 reverse order except for PARM_DECL node, which are explicitly stored in
300 current_binding_level->names
301 = decl_chain = (reverse) ? nreverse (current_binding_level->names)
302 : current_binding_level->names;
304 /* Output any nested inline functions within this block which must be
305 compiled because their address is needed. */
306 for (decl_node = decl_chain; decl_node; decl_node = TREE_CHAIN (decl_node))
307 if (TREE_CODE (decl_node) == FUNCTION_DECL
308 && ! TREE_ASM_WRITTEN (decl_node) && TREE_ADDRESSABLE (decl_node)
309 && DECL_INITIAL (decl_node) != 0)
311 push_function_context ();
312 output_inline_function (decl_node);
313 pop_function_context ();
317 block_previously_created = (current_binding_level->this_block != 0);
318 if (block_previously_created)
319 block = current_binding_level->this_block;
320 else if (keep || functionbody)
321 block = make_node (BLOCK);
324 BLOCK_VARS (block) = keep ? decl_chain : 0;
325 BLOCK_SUBBLOCKS (block) = subblock_chain;
328 /* Record the BLOCK node just built as the subblock its enclosing scope. */
329 for (subblock_node = subblock_chain; subblock_node;
330 subblock_node = TREE_CHAIN (subblock_node))
331 BLOCK_SUPERCONTEXT (subblock_node) = block;
333 /* Clear out the meanings of the local variables of this level. */
335 for (subblock_node = decl_chain; subblock_node;
336 subblock_node = TREE_CHAIN (subblock_node))
337 if (DECL_NAME (subblock_node) != 0)
338 /* If the identifier was used or addressed via a local extern decl,
339 don't forget that fact. */
340 if (DECL_EXTERNAL (subblock_node))
342 if (TREE_USED (subblock_node))
343 TREE_USED (DECL_NAME (subblock_node)) = 1;
344 if (TREE_ADDRESSABLE (subblock_node))
345 TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (subblock_node)) = 1;
349 /* Pop the current level, and free the structure for reuse. */
350 struct binding_level *level = current_binding_level;
351 current_binding_level = current_binding_level->level_chain;
352 level->level_chain = free_binding_level;
353 free_binding_level = level;
358 /* This is the top level block of a function. The ..._DECL chain stored
359 in BLOCK_VARS are the function's parameters (PARM_DECL nodes). Don't
360 leave them in the BLOCK because they are found in the FUNCTION_DECL
362 DECL_INITIAL (current_function_decl) = block;
363 BLOCK_VARS (block) = 0;
367 if (!block_previously_created)
368 current_binding_level->blocks
369 = chainon (current_binding_level->blocks, block);
372 /* If we did not make a block for the level just exited, any blocks made for
373 inner levels (since they cannot be recorded as subblocks in that level)
374 must be carried forward so they will later become subblocks of something
376 else if (subblock_chain)
377 current_binding_level->blocks
378 = chainon (current_binding_level->blocks, subblock_chain);
380 TREE_USED (block) = 1;
385 /* Insert BLOCK at the end of the list of subblocks of the
386 current binding level. This is used when a BIND_EXPR is expanded,
387 to handle the BLOCK node inside the BIND_EXPR. */
390 insert_block (tree block)
392 TREE_USED (block) = 1;
393 current_binding_level->blocks
394 = chainon (current_binding_level->blocks, block);
397 /* Set the BLOCK node for the innermost scope
398 (the one we are currently in). */
401 set_block (tree block)
403 current_binding_level->this_block = block;
404 current_binding_level->names = chainon (current_binding_level->names,
406 current_binding_level->blocks = chainon (current_binding_level->blocks,
407 BLOCK_SUBBLOCKS (block));
410 /* Records a ..._DECL node DECL as belonging to the current lexical scope.
411 Returns the ..._DECL node. */
416 struct binding_level *b;
418 /* If at top level, there is no context. But PARM_DECLs always go in the
419 level of its function. */
420 if (global_bindings_p () && TREE_CODE (decl) != PARM_DECL)
422 b = global_binding_level;
423 DECL_CONTEXT (decl) = 0;
427 b = current_binding_level;
428 DECL_CONTEXT (decl) = current_function_decl;
431 /* Put the declaration on the list. The list of declarations is in reverse
432 order. The list will be reversed later if necessary. This needs to be
433 this way for compatibility with the back-end.
435 Don't put TYPE_DECLs for UNCONSTRAINED_ARRAY_TYPE into the list. They
436 will cause trouble with the debugger and aren't needed anyway. */
437 if (TREE_CODE (decl) != TYPE_DECL
438 || TREE_CODE (TREE_TYPE (decl)) != UNCONSTRAINED_ARRAY_TYPE)
440 TREE_CHAIN (decl) = b->names;
444 /* For the declaration of a type, set its name if it either is not already
445 set, was set to an IDENTIFIER_NODE, indicating an internal name,
446 or if the previous type name was not derived from a source name.
447 We'd rather have the type named with a real name and all the pointer
448 types to the same object have the same POINTER_TYPE node. Code in this
449 function in c-decl.c makes a copy of the type node here, but that may
450 cause us trouble with incomplete types, so let's not try it (at least
453 if (TREE_CODE (decl) == TYPE_DECL
454 && DECL_NAME (decl) != 0
455 && (TYPE_NAME (TREE_TYPE (decl)) == 0
456 || TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == IDENTIFIER_NODE
457 || (TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == TYPE_DECL
458 && DECL_ARTIFICIAL (TYPE_NAME (TREE_TYPE (decl)))
459 && ! DECL_ARTIFICIAL (decl))))
460 TYPE_NAME (TREE_TYPE (decl)) = decl;
465 /* Do little here. Set up the standard declarations later after the
466 front end has been run. */
469 gnat_init_decl_processing (void)
473 /* Make the binding_level structure for global names. */
474 current_function_decl = 0;
475 current_binding_level = 0;
476 free_binding_level = 0;
478 global_binding_level = current_binding_level;
480 build_common_tree_nodes (0);
482 /* In Ada, we use a signed type for SIZETYPE. Use the signed type
483 corresponding to the size of Pmode. In most cases when ptr_mode and
484 Pmode differ, C will use the width of ptr_mode as sizetype. But we get
485 far better code using the width of Pmode. Make this here since we need
486 this before we can expand the GNAT types. */
487 set_sizetype (gnat_type_for_size (GET_MODE_BITSIZE (Pmode), 0));
488 build_common_tree_nodes_2 (0);
490 pushdecl (build_decl (TYPE_DECL, get_identifier (SIZE_TYPE), sizetype));
492 /* We need to make the integer type before doing anything else.
493 We stitch this in to the appropriate GNAT type later. */
494 pushdecl (build_decl (TYPE_DECL, get_identifier ("integer"),
496 pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned char"),
499 ptr_void_type_node = build_pointer_type (void_type_node);
503 /* Create the predefined scalar types such as `integer_type_node' needed
504 in the gcc back-end and initialize the global binding level. */
507 init_gigi_decls (tree long_long_float_type, tree exception_type)
512 /* Set the types that GCC and Gigi use from the front end. We would like
513 to do this for char_type_node, but it needs to correspond to the C
515 if (TREE_CODE (TREE_TYPE (long_long_float_type)) == INTEGER_TYPE)
517 /* In this case, the builtin floating point types are VAX float,
518 so make up a type for use. */
519 longest_float_type_node = make_node (REAL_TYPE);
520 TYPE_PRECISION (longest_float_type_node) = LONG_DOUBLE_TYPE_SIZE;
521 layout_type (longest_float_type_node);
522 pushdecl (build_decl (TYPE_DECL, get_identifier ("longest float type"),
523 longest_float_type_node));
526 longest_float_type_node = TREE_TYPE (long_long_float_type);
528 except_type_node = TREE_TYPE (exception_type);
530 unsigned_type_node = gnat_type_for_size (INT_TYPE_SIZE, 1);
531 pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned int"),
532 unsigned_type_node));
535 = pushdecl (build_decl (TYPE_DECL, get_identifier ("void"),
538 void_ftype = build_function_type (void_type_node, NULL_TREE);
539 ptr_void_ftype = build_pointer_type (void_ftype);
541 /* Now declare runtime functions. */
542 endlink = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
544 /* malloc is a function declaration tree for a function to allocate
546 malloc_decl = create_subprog_decl (get_identifier ("__gnat_malloc"),
548 build_function_type (ptr_void_type_node,
549 tree_cons (NULL_TREE,
552 NULL_TREE, 0, 1, 1, 0);
554 /* free is a function declaration tree for a function to free memory. */
556 = create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE,
557 build_function_type (void_type_node,
558 tree_cons (NULL_TREE,
561 NULL_TREE, 0, 1, 1, 0);
563 /* Make the types and functions used for exception processing. */
565 = build_array_type (gnat_type_for_mode (Pmode, 0),
566 build_index_type (build_int_2 (5, 0)));
567 pushdecl (build_decl (TYPE_DECL, get_identifier ("JMPBUF_T"), jmpbuf_type));
568 jmpbuf_ptr_type = build_pointer_type (jmpbuf_type);
570 /* Functions to get and set the jumpbuf pointer for the current thread. */
572 = create_subprog_decl
573 (get_identifier ("system__soft_links__get_jmpbuf_address_soft"),
574 NULL_TREE, build_function_type (jmpbuf_ptr_type, NULL_TREE),
575 NULL_TREE, 0, 1, 1, 0);
578 = create_subprog_decl
579 (get_identifier ("system__soft_links__set_jmpbuf_address_soft"),
581 build_function_type (void_type_node,
582 tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
583 NULL_TREE, 0, 1, 1, 0);
585 /* Function to get the current exception. */
587 = create_subprog_decl
588 (get_identifier ("system__soft_links__get_gnat_exception"),
590 build_function_type (build_pointer_type (except_type_node), NULL_TREE),
591 NULL_TREE, 0, 1, 1, 0);
593 /* Functions that raise exceptions. */
595 = create_subprog_decl
596 (get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE,
597 build_function_type (void_type_node,
598 tree_cons (NULL_TREE,
599 build_pointer_type (except_type_node),
601 NULL_TREE, 0, 1, 1, 0);
603 /* Hooks to call when entering/leaving an exception handler. */
605 = create_subprog_decl (get_identifier ("__gnat_begin_handler"), NULL_TREE,
606 build_function_type (void_type_node,
607 tree_cons (NULL_TREE,
610 NULL_TREE, 0, 1, 1, 0);
613 = create_subprog_decl (get_identifier ("__gnat_end_handler"), NULL_TREE,
614 build_function_type (void_type_node,
615 tree_cons (NULL_TREE,
618 NULL_TREE, 0, 1, 1, 0);
620 /* If in no exception handlers mode, all raise statements are redirected to
621 __gnat_last_chance_handler. No need to redefine raise_nodefer_decl, since
622 this procedure will never be called in this mode. */
623 if (No_Exception_Handlers_Set ())
626 = create_subprog_decl
627 (get_identifier ("__gnat_last_chance_handler"), NULL_TREE,
628 build_function_type (void_type_node,
629 tree_cons (NULL_TREE,
630 build_pointer_type (char_type_node),
631 tree_cons (NULL_TREE,
634 NULL_TREE, 0, 1, 1, 0);
636 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
637 gnat_raise_decls[i] = decl;
640 /* Otherwise, make one decl for each exception reason. */
641 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
645 sprintf (name, "__gnat_rcheck_%.2d", i);
647 = create_subprog_decl
648 (get_identifier (name), NULL_TREE,
649 build_function_type (void_type_node,
650 tree_cons (NULL_TREE,
653 tree_cons (NULL_TREE,
656 NULL_TREE, 0, 1, 1, 0);
659 /* Indicate that these never return. */
660 TREE_THIS_VOLATILE (raise_nodefer_decl) = 1;
661 TREE_SIDE_EFFECTS (raise_nodefer_decl) = 1;
662 TREE_TYPE (raise_nodefer_decl)
663 = build_qualified_type (TREE_TYPE (raise_nodefer_decl),
666 for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++)
668 TREE_THIS_VOLATILE (gnat_raise_decls[i]) = 1;
669 TREE_SIDE_EFFECTS (gnat_raise_decls[i]) = 1;
670 TREE_TYPE (gnat_raise_decls[i])
671 = build_qualified_type (TREE_TYPE (gnat_raise_decls[i]),
675 /* setjmp returns an integer and has one operand, which is a pointer to
678 = create_subprog_decl
679 (get_identifier ("__builtin_setjmp"), NULL_TREE,
680 build_function_type (integer_type_node,
681 tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)),
682 NULL_TREE, 0, 1, 1, 0);
684 DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL;
685 DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP;
687 main_identifier_node = get_identifier ("main");
690 /* Given a record type (RECORD_TYPE) and a chain of FIELD_DECL
691 nodes (FIELDLIST), finish constructing the record or union type.
692 If HAS_REP is nonzero, this record has a rep clause; don't call
693 layout_type but merely set the size and alignment ourselves.
694 If DEFER_DEBUG is nonzero, do not call the debugging routines
695 on this type; it will be done later. */
698 finish_record_type (tree record_type,
703 enum tree_code code = TREE_CODE (record_type);
704 tree ada_size = bitsize_zero_node;
705 tree size = bitsize_zero_node;
706 tree size_unit = size_zero_node;
710 TYPE_FIELDS (record_type) = fieldlist;
712 if (TYPE_NAME (record_type) != 0
713 && TREE_CODE (TYPE_NAME (record_type)) == TYPE_DECL)
714 TYPE_STUB_DECL (record_type) = TYPE_NAME (record_type);
716 TYPE_STUB_DECL (record_type)
717 = pushdecl (build_decl (TYPE_DECL, TYPE_NAME (record_type),
720 /* We don't need both the typedef name and the record name output in
721 the debugging information, since they are the same. */
722 DECL_ARTIFICIAL (TYPE_STUB_DECL (record_type)) = 1;
724 /* Globally initialize the record first. If this is a rep'ed record,
725 that just means some initializations; otherwise, layout the record. */
729 TYPE_ALIGN (record_type) = MAX (BITS_PER_UNIT, TYPE_ALIGN (record_type));
730 TYPE_MODE (record_type) = BLKmode;
731 if (TYPE_SIZE (record_type) == 0)
733 TYPE_SIZE (record_type) = bitsize_zero_node;
734 TYPE_SIZE_UNIT (record_type) = size_zero_node;
736 /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE
737 out just like a UNION_TYPE, since the size will be fixed. */
738 else if (code == QUAL_UNION_TYPE)
743 /* Ensure there isn't a size already set. There can be in an error
744 case where there is a rep clause but all fields have errors and
745 no longer have a position. */
746 TYPE_SIZE (record_type) = 0;
747 layout_type (record_type);
750 /* At this point, the position and size of each field is known. It was
751 either set before entry by a rep clause, or by laying out the type above.
753 We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs)
754 to compute the Ada size; the GCC size and alignment (for rep'ed records
755 that are not padding types); and the mode (for rep'ed records). We also
756 clear the DECL_BIT_FIELD indication for the cases we know have not been
757 handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */
759 if (code == QUAL_UNION_TYPE)
760 fieldlist = nreverse (fieldlist);
762 for (field = fieldlist; field; field = TREE_CHAIN (field))
764 tree pos = bit_position (field);
766 tree type = TREE_TYPE (field);
767 tree this_size = DECL_SIZE (field);
768 tree this_size_unit = DECL_SIZE_UNIT (field);
769 tree this_ada_size = DECL_SIZE (field);
771 /* We need to make an XVE/XVU record if any field has variable size,
772 whether or not the record does. For example, if we have an union,
773 it may be that all fields, rounded up to the alignment, have the
774 same size, in which case we'll use that size. But the debug
775 output routines (except Dwarf2) won't be able to output the fields,
776 so we need to make the special record. */
777 if (TREE_CODE (this_size) != INTEGER_CST)
780 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
781 || TREE_CODE (type) == QUAL_UNION_TYPE)
782 && ! TYPE_IS_FAT_POINTER_P (type)
783 && ! TYPE_CONTAINS_TEMPLATE_P (type)
784 && TYPE_ADA_SIZE (type) != 0)
785 this_ada_size = TYPE_ADA_SIZE (type);
787 /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */
788 if (DECL_BIT_FIELD (field) && !STRICT_ALIGNMENT
789 && value_factor_p (pos, BITS_PER_UNIT)
790 && operand_equal_p (this_size, TYPE_SIZE (type), 0))
791 DECL_BIT_FIELD (field) = 0;
793 /* If we still have DECL_BIT_FIELD set at this point, we know the field
794 is technically not addressable. Except that it can actually be
795 addressed if the field is BLKmode and happens to be properly
797 DECL_NONADDRESSABLE_P (field)
798 |= DECL_BIT_FIELD (field) && DECL_MODE (field) != BLKmode;
800 if (has_rep && ! DECL_BIT_FIELD (field))
801 TYPE_ALIGN (record_type)
802 = MAX (TYPE_ALIGN (record_type), DECL_ALIGN (field));
807 ada_size = size_binop (MAX_EXPR, ada_size, this_ada_size);
808 size = size_binop (MAX_EXPR, size, this_size);
809 size_unit = size_binop (MAX_EXPR, size_unit, this_size_unit);
812 case QUAL_UNION_TYPE:
814 = fold (build (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
815 this_ada_size, ada_size));
816 size = fold (build (COND_EXPR, bitsizetype, DECL_QUALIFIER (field),
818 size_unit = fold (build (COND_EXPR, sizetype, DECL_QUALIFIER (field),
819 this_size_unit, size_unit));
823 /* Since we know here that all fields are sorted in order of
824 increasing bit position, the size of the record is one
825 higher than the ending bit of the last field processed
826 unless we have a rep clause, since in that case we might
827 have a field outside a QUAL_UNION_TYPE that has a higher ending
828 position. So use a MAX in that case. Also, if this field is a
829 QUAL_UNION_TYPE, we need to take into account the previous size in
830 the case of empty variants. */
832 = merge_sizes (ada_size, pos, this_ada_size,
833 TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
834 size = merge_sizes (size, pos, this_size,
835 TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
837 = merge_sizes (size_unit, byte_position (field), this_size_unit,
838 TREE_CODE (type) == QUAL_UNION_TYPE, has_rep);
846 if (code == QUAL_UNION_TYPE)
847 nreverse (fieldlist);
849 /* If this is a padding record, we never want to make the size smaller than
850 what was specified in it, if any. */
851 if (TREE_CODE (record_type) == RECORD_TYPE
852 && TYPE_IS_PADDING_P (record_type) && TYPE_SIZE (record_type) != 0)
854 size = TYPE_SIZE (record_type);
855 size_unit = TYPE_SIZE_UNIT (record_type);
858 /* Now set any of the values we've just computed that apply. */
859 if (! TYPE_IS_FAT_POINTER_P (record_type)
860 && ! TYPE_CONTAINS_TEMPLATE_P (record_type))
861 SET_TYPE_ADA_SIZE (record_type, ada_size);
865 if (! (TREE_CODE (record_type) == RECORD_TYPE
866 && TYPE_IS_PADDING_P (record_type)
867 && CONTAINS_PLACEHOLDER_P (size)))
869 TYPE_SIZE (record_type) = round_up (size, TYPE_ALIGN (record_type));
870 TYPE_SIZE_UNIT (record_type)
871 = round_up (size_unit,
872 TYPE_ALIGN (record_type) / BITS_PER_UNIT);
875 compute_record_mode (record_type);
880 /* If this record is of variable size, rename it so that the
881 debugger knows it is and make a new, parallel, record
882 that tells the debugger how the record is laid out. See
883 exp_dbug.ads. But don't do this for records that are padding
884 since they confuse GDB. */
886 && ! (TREE_CODE (record_type) == RECORD_TYPE
887 && TYPE_IS_PADDING_P (record_type)))
890 = make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE
891 ? UNION_TYPE : TREE_CODE (record_type));
892 tree orig_id = DECL_NAME (TYPE_STUB_DECL (record_type));
894 = concat_id_with_name (orig_id,
895 TREE_CODE (record_type) == QUAL_UNION_TYPE
897 tree last_pos = bitsize_zero_node;
899 tree prev_old_field = 0;
901 TYPE_NAME (new_record_type) = new_id;
902 TYPE_ALIGN (new_record_type) = BIGGEST_ALIGNMENT;
903 TYPE_STUB_DECL (new_record_type)
904 = pushdecl (build_decl (TYPE_DECL, new_id, new_record_type));
905 DECL_ARTIFICIAL (TYPE_STUB_DECL (new_record_type)) = 1;
906 DECL_IGNORED_P (TYPE_STUB_DECL (new_record_type))
907 = DECL_IGNORED_P (TYPE_STUB_DECL (record_type));
908 TYPE_SIZE (new_record_type) = size_int (TYPE_ALIGN (record_type));
910 /* Now scan all the fields, replacing each field with a new
911 field corresponding to the new encoding. */
912 for (old_field = TYPE_FIELDS (record_type); old_field != 0;
913 old_field = TREE_CHAIN (old_field))
915 tree field_type = TREE_TYPE (old_field);
916 tree field_name = DECL_NAME (old_field);
918 tree curpos = bit_position (old_field);
920 unsigned int align = 0;
923 /* See how the position was modified from the last position.
925 There are two basic cases we support: a value was added
926 to the last position or the last position was rounded to
927 a boundary and they something was added. Check for the
928 first case first. If not, see if there is any evidence
929 of rounding. If so, round the last position and try
932 If this is a union, the position can be taken as zero. */
934 if (TREE_CODE (new_record_type) == UNION_TYPE)
935 pos = bitsize_zero_node, align = 0;
937 pos = compute_related_constant (curpos, last_pos);
939 if (pos == 0 && TREE_CODE (curpos) == MULT_EXPR
940 && TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST)
942 align = TREE_INT_CST_LOW (TREE_OPERAND (curpos, 1));
943 pos = compute_related_constant (curpos,
944 round_up (last_pos, align));
946 else if (pos == 0 && TREE_CODE (curpos) == PLUS_EXPR
947 && TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST
948 && TREE_CODE (TREE_OPERAND (curpos, 0)) == MULT_EXPR
949 && host_integerp (TREE_OPERAND
950 (TREE_OPERAND (curpos, 0), 1),
955 (TREE_OPERAND (TREE_OPERAND (curpos, 0), 1), 1);
956 pos = compute_related_constant (curpos,
957 round_up (last_pos, align));
959 else if (potential_alignment_gap (prev_old_field, old_field,
962 align = TYPE_ALIGN (field_type);
963 pos = compute_related_constant (curpos,
964 round_up (last_pos, align));
967 /* If we can't compute a position, set it to zero.
969 ??? We really should abort here, but it's too much work
970 to get this correct for all cases. */
973 pos = bitsize_zero_node;
975 /* See if this type is variable-size and make a new type
976 and indicate the indirection if so. */
977 if (TREE_CODE (DECL_SIZE (old_field)) != INTEGER_CST)
979 field_type = build_pointer_type (field_type);
983 /* Make a new field name, if necessary. */
984 if (var || align != 0)
989 sprintf (suffix, "XV%c%u", var ? 'L' : 'A',
990 align / BITS_PER_UNIT);
992 strcpy (suffix, "XVL");
994 field_name = concat_id_with_name (field_name, suffix);
997 new_field = create_field_decl (field_name, field_type,
999 DECL_SIZE (old_field), pos, 0);
1000 TREE_CHAIN (new_field) = TYPE_FIELDS (new_record_type);
1001 TYPE_FIELDS (new_record_type) = new_field;
1003 /* If old_field is a QUAL_UNION_TYPE, take its size as being
1004 zero. The only time it's not the last field of the record
1005 is when there are other components at fixed positions after
1006 it (meaning there was a rep clause for every field) and we
1007 want to be able to encode them. */
1008 last_pos = size_binop (PLUS_EXPR, bit_position (old_field),
1009 (TREE_CODE (TREE_TYPE (old_field))
1012 : DECL_SIZE (old_field));
1013 prev_old_field = old_field;
1016 TYPE_FIELDS (new_record_type)
1017 = nreverse (TYPE_FIELDS (new_record_type));
1019 rest_of_type_compilation (new_record_type, global_bindings_p ());
1022 rest_of_type_compilation (record_type, global_bindings_p ());
1026 /* Utility function of above to merge LAST_SIZE, the previous size of a record
1027 with FIRST_BIT and SIZE that describe a field. SPECIAL is nonzero
1028 if this represents a QUAL_UNION_TYPE in which case we must look for
1029 COND_EXPRs and replace a value of zero with the old size. If HAS_REP
1030 is nonzero, we must take the MAX of the end position of this field
1031 with LAST_SIZE. In all other cases, we use FIRST_BIT plus SIZE.
1033 We return an expression for the size. */
1036 merge_sizes (tree last_size,
1042 tree type = TREE_TYPE (last_size);
1045 if (! special || TREE_CODE (size) != COND_EXPR)
1047 new = size_binop (PLUS_EXPR, first_bit, size);
1049 new = size_binop (MAX_EXPR, last_size, new);
1053 new = fold (build (COND_EXPR, type, TREE_OPERAND (size, 0),
1054 integer_zerop (TREE_OPERAND (size, 1))
1055 ? last_size : merge_sizes (last_size, first_bit,
1056 TREE_OPERAND (size, 1),
1058 integer_zerop (TREE_OPERAND (size, 2))
1059 ? last_size : merge_sizes (last_size, first_bit,
1060 TREE_OPERAND (size, 2),
1063 /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially
1064 when fed through substitute_in_expr) into thinking that a constant
1065 size is not constant. */
1066 while (TREE_CODE (new) == NON_LVALUE_EXPR)
1067 new = TREE_OPERAND (new, 0);
1072 /* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are
1073 related by the addition of a constant. Return that constant if so. */
1076 compute_related_constant (tree op0, tree op1)
1078 tree op0_var, op1_var;
1079 tree op0_con = split_plus (op0, &op0_var);
1080 tree op1_con = split_plus (op1, &op1_var);
1081 tree result = size_binop (MINUS_EXPR, op0_con, op1_con);
1083 if (operand_equal_p (op0_var, op1_var, 0))
1085 else if (operand_equal_p (op0, size_binop (PLUS_EXPR, op1_var, result), 0))
1091 /* Utility function of above to split a tree OP which may be a sum, into a
1092 constant part, which is returned, and a variable part, which is stored
1093 in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of
1097 split_plus (tree in, tree *pvar)
1099 /* Strip NOPS in order to ease the tree traversal and maximize the
1100 potential for constant or plus/minus discovery. We need to be careful
1101 to always return and set *pvar to bitsizetype trees, but it's worth
1105 *pvar = convert (bitsizetype, in);
1107 if (TREE_CODE (in) == INTEGER_CST)
1109 *pvar = bitsize_zero_node;
1110 return convert (bitsizetype, in);
1112 else if (TREE_CODE (in) == PLUS_EXPR || TREE_CODE (in) == MINUS_EXPR)
1114 tree lhs_var, rhs_var;
1115 tree lhs_con = split_plus (TREE_OPERAND (in, 0), &lhs_var);
1116 tree rhs_con = split_plus (TREE_OPERAND (in, 1), &rhs_var);
1118 if (lhs_var == TREE_OPERAND (in, 0)
1119 && rhs_var == TREE_OPERAND (in, 1))
1120 return bitsize_zero_node;
1122 *pvar = size_binop (TREE_CODE (in), lhs_var, rhs_var);
1123 return size_binop (TREE_CODE (in), lhs_con, rhs_con);
1126 return bitsize_zero_node;
1129 /* Return a FUNCTION_TYPE node. RETURN_TYPE is the type returned by the
1130 subprogram. If it is void_type_node, then we are dealing with a procedure,
1131 otherwise we are dealing with a function. PARAM_DECL_LIST is a list of
1132 PARM_DECL nodes that are the subprogram arguments. CICO_LIST is the
1133 copy-in/copy-out list to be stored into TYPE_CICO_LIST.
1134 RETURNS_UNCONSTRAINED is nonzero if the function returns an unconstrained
1135 object. RETURNS_BY_REF is nonzero if the function returns by reference.
1136 RETURNS_WITH_DSP is nonzero if the function is to return with a
1137 depressed stack pointer. */
1140 create_subprog_type (tree return_type,
1141 tree param_decl_list,
1143 int returns_unconstrained,
1145 int returns_with_dsp)
1147 /* A chain of TREE_LIST nodes whose TREE_VALUEs are the data type nodes of
1148 the subprogram formal parameters. This list is generated by traversing the
1149 input list of PARM_DECL nodes. */
1150 tree param_type_list = NULL;
1154 for (param_decl = param_decl_list; param_decl;
1155 param_decl = TREE_CHAIN (param_decl))
1156 param_type_list = tree_cons (NULL_TREE, TREE_TYPE (param_decl),
1159 /* The list of the function parameter types has to be terminated by the void
1160 type to signal to the back-end that we are not dealing with a variable
1161 parameter subprogram, but that the subprogram has a fixed number of
1163 param_type_list = tree_cons (NULL_TREE, void_type_node, param_type_list);
1165 /* The list of argument types has been created in reverse
1167 param_type_list = nreverse (param_type_list);
1169 type = build_function_type (return_type, param_type_list);
1171 /* TYPE may have been shared since GCC hashes types. If it has a CICO_LIST
1172 or the new type should, make a copy of TYPE. Likewise for
1173 RETURNS_UNCONSTRAINED and RETURNS_BY_REF. */
1174 if (TYPE_CI_CO_LIST (type) != 0 || cico_list != 0
1175 || TYPE_RETURNS_UNCONSTRAINED_P (type) != returns_unconstrained
1176 || TYPE_RETURNS_BY_REF_P (type) != returns_by_ref)
1177 type = copy_type (type);
1179 SET_TYPE_CI_CO_LIST (type, cico_list);
1180 TYPE_RETURNS_UNCONSTRAINED_P (type) = returns_unconstrained;
1181 TYPE_RETURNS_STACK_DEPRESSED (type) = returns_with_dsp;
1182 TYPE_RETURNS_BY_REF_P (type) = returns_by_ref;
1186 /* Return a copy of TYPE but safe to modify in any way. */
1189 copy_type (tree type)
1191 tree new = copy_node (type);
1193 /* copy_node clears this field instead of copying it, because it is
1194 aliased with TREE_CHAIN. */
1195 TYPE_STUB_DECL (new) = TYPE_STUB_DECL (type);
1197 TYPE_POINTER_TO (new) = 0;
1198 TYPE_REFERENCE_TO (new) = 0;
1199 TYPE_MAIN_VARIANT (new) = new;
1200 TYPE_NEXT_VARIANT (new) = 0;
1205 /* Return an INTEGER_TYPE of SIZETYPE with range MIN to MAX and whose
1206 TYPE_INDEX_TYPE is INDEX. */
1209 create_index_type (tree min, tree max, tree index)
1211 /* First build a type for the desired range. */
1212 tree type = build_index_2_type (min, max);
1214 /* If this type has the TYPE_INDEX_TYPE we want, return it. Otherwise, if it
1215 doesn't have TYPE_INDEX_TYPE set, set it to INDEX. If TYPE_INDEX_TYPE
1216 is set, but not to INDEX, make a copy of this type with the requested
1217 index type. Note that we have no way of sharing these types, but that's
1218 only a small hole. */
1219 if (TYPE_INDEX_TYPE (type) == index)
1221 else if (TYPE_INDEX_TYPE (type) != 0)
1222 type = copy_type (type);
1224 SET_TYPE_INDEX_TYPE (type, index);
1228 /* Return a TYPE_DECL node. TYPE_NAME gives the name of the type (a character
1229 string) and TYPE is a ..._TYPE node giving its data type.
1230 ARTIFICIAL_P is nonzero if this is a declaration that was generated
1231 by the compiler. DEBUG_INFO_P is nonzero if we need to write debugging
1232 information about this type. */
1235 create_type_decl (tree type_name,
1237 struct attrib *attr_list,
1241 tree type_decl = build_decl (TYPE_DECL, type_name, type);
1242 enum tree_code code = TREE_CODE (type);
1244 DECL_ARTIFICIAL (type_decl) = artificial_p;
1245 pushdecl (type_decl);
1246 process_attributes (type_decl, attr_list);
1248 /* Pass type declaration information to the debugger unless this is an
1249 UNCONSTRAINED_ARRAY_TYPE, which the debugger does not support,
1250 and ENUMERAL_TYPE or RECORD_TYPE which is handled separately,
1251 a dummy type, which will be completed later, or a type for which
1252 debugging information was not requested. */
1253 if (code == UNCONSTRAINED_ARRAY_TYPE || TYPE_IS_DUMMY_P (type)
1255 DECL_IGNORED_P (type_decl) = 1;
1256 else if (code != ENUMERAL_TYPE && code != RECORD_TYPE
1257 && ! ((code == POINTER_TYPE || code == REFERENCE_TYPE)
1258 && TYPE_IS_DUMMY_P (TREE_TYPE (type))))
1259 rest_of_decl_compilation (type_decl, NULL, global_bindings_p (), 0);
1264 /* Returns a GCC VAR_DECL node. VAR_NAME gives the name of the variable.
1265 ASM_NAME is its assembler name (if provided). TYPE is its data type
1266 (a GCC ..._TYPE node). VAR_INIT is the GCC tree for an optional initial
1267 expression; NULL_TREE if none.
1269 CONST_FLAG is nonzero if this variable is constant.
1271 PUBLIC_FLAG is nonzero if this definition is to be made visible outside of
1272 the current compilation unit. This flag should be set when processing the
1273 variable definitions in a package specification. EXTERN_FLAG is nonzero
1274 when processing an external variable declaration (as opposed to a
1275 definition: no storage is to be allocated for the variable here).
1277 STATIC_FLAG is only relevant when not at top level. In that case
1278 it indicates whether to always allocate storage to the variable. */
1281 create_var_decl (tree var_name,
1289 struct attrib *attr_list)
1294 : (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (var_init))
1295 && (global_bindings_p () || static_flag
1296 ? 0 != initializer_constant_valid_p (var_init,
1297 TREE_TYPE (var_init))
1298 : TREE_CONSTANT (var_init))));
1300 = build_decl ((const_flag && init_const
1301 /* Only make a CONST_DECL for sufficiently-small objects.
1302 We consider complex double "sufficiently-small" */
1303 && TYPE_SIZE (type) != 0
1304 && host_integerp (TYPE_SIZE_UNIT (type), 1)
1305 && 0 >= compare_tree_int (TYPE_SIZE_UNIT (type),
1306 GET_MODE_SIZE (DCmode)))
1307 ? CONST_DECL : VAR_DECL, var_name, type);
1308 tree assign_init = 0;
1310 /* If this is external, throw away any initializations unless this is a
1311 CONST_DECL (meaning we have a constant); they will be done elsewhere. If
1312 we are defining a global here, leave a constant initialization and save
1313 any variable elaborations for the elaboration routine. Otherwise, if
1314 the initializing expression is not the same as TYPE, generate the
1315 initialization with an assignment statement, since it knows how
1316 to do the required adjustents. If we are just annotating types,
1317 throw away the initialization if it isn't a constant. */
1319 if ((extern_flag && TREE_CODE (var_decl) != CONST_DECL)
1320 || (type_annotate_only && var_init != 0 && ! TREE_CONSTANT (var_init)))
1323 if (global_bindings_p () && var_init != 0 && ! init_const)
1325 add_pending_elaborations (var_decl, var_init);
1329 else if (var_init != 0
1330 && ((TYPE_MAIN_VARIANT (TREE_TYPE (var_init))
1331 != TYPE_MAIN_VARIANT (type))
1332 || (static_flag && ! init_const)))
1333 assign_init = var_init, var_init = 0;
1335 DECL_COMMON (var_decl) = !flag_no_common;
1336 DECL_INITIAL (var_decl) = var_init;
1337 TREE_READONLY (var_decl) = const_flag;
1338 DECL_EXTERNAL (var_decl) = extern_flag;
1339 TREE_PUBLIC (var_decl) = public_flag || extern_flag;
1340 TREE_CONSTANT (var_decl) = TREE_CODE (var_decl) == CONST_DECL;
1341 TREE_THIS_VOLATILE (var_decl) = TREE_SIDE_EFFECTS (var_decl)
1342 = TYPE_VOLATILE (type);
1344 /* At the global binding level we need to allocate static storage for the
1345 variable if and only if its not external. If we are not at the top level
1346 we allocate automatic storage unless requested not to. */
1347 TREE_STATIC (var_decl) = global_bindings_p () ? !extern_flag : static_flag;
1350 SET_DECL_ASSEMBLER_NAME (var_decl, asm_name);
1352 process_attributes (var_decl, attr_list);
1354 /* Add this decl to the current binding level and generate any
1355 needed code and RTL. */
1356 var_decl = pushdecl (var_decl);
1357 expand_decl (var_decl);
1359 if (DECL_CONTEXT (var_decl) != 0)
1360 expand_decl_init (var_decl);
1362 /* If this is volatile, force it into memory. */
1363 if (TREE_SIDE_EFFECTS (var_decl))
1364 gnat_mark_addressable (var_decl);
1366 if (TREE_CODE (var_decl) != CONST_DECL)
1367 rest_of_decl_compilation (var_decl, 0, global_bindings_p (), 0);
1369 if (assign_init != 0)
1371 /* If VAR_DECL has a padded type, convert it to the unpadded
1372 type so the assignment is done properly. */
1373 tree lhs = var_decl;
1375 if (TREE_CODE (TREE_TYPE (lhs)) == RECORD_TYPE
1376 && TYPE_IS_PADDING_P (TREE_TYPE (lhs)))
1377 lhs = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (lhs))), lhs);
1379 expand_expr_stmt (build_binary_op (MODIFY_EXPR, NULL_TREE, lhs,
1386 /* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its
1387 type, and RECORD_TYPE is the type of the parent. PACKED is nonzero if
1388 this field is in a record type with a "pragma pack". If SIZE is nonzero
1389 it is the specified size for this field. If POS is nonzero, it is the bit
1390 position. If ADDRESSABLE is nonzero, it means we are allowed to take
1391 the address of this field for aliasing purposes. */
1394 create_field_decl (tree field_name,
1402 tree field_decl = build_decl (FIELD_DECL, field_name, field_type);
1404 DECL_CONTEXT (field_decl) = record_type;
1405 TREE_READONLY (field_decl) = TREE_READONLY (field_type);
1407 /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a
1408 byte boundary since GCC cannot handle less-aligned BLKmode bitfields. */
1409 if (packed && TYPE_MODE (field_type) == BLKmode)
1410 DECL_ALIGN (field_decl) = BITS_PER_UNIT;
1412 /* If a size is specified, use it. Otherwise, if the record type is packed
1413 compute a size to use, which may differ from the object's natural size.
1414 We always set a size in this case to trigger the checks for bitfield
1415 creation below, which is typically required when no position has been
1418 size = convert (bitsizetype, size);
1419 else if (packed == 1)
1421 size = rm_size (field_type);
1423 /* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to
1425 if (TREE_CODE (size) == INTEGER_CST
1426 && compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0)
1427 size = round_up (size, BITS_PER_UNIT);
1430 /* Make a bitfield if a size is specified for two reasons: first if the size
1431 differs from the natural size. Second, if the alignment is insufficient.
1432 There are a number of ways the latter can be true.
1434 We never make a bitfield if the type of the field has a nonconstant size,
1435 or if it is claimed to be addressable, because no such entity requiring
1436 bitfield operations should reach here.
1438 We do *preventively* make a bitfield when there might be the need for it
1439 but we don't have all the necessary information to decide, as is the case
1440 of a field with no specified position in a packed record.
1442 We also don't look at STRICT_ALIGNMENT here, and rely on later processing
1443 in layout_decl or finish_record_type to clear the bit_field indication if
1444 it is in fact not needed. */
1445 if (size != 0 && TREE_CODE (size) == INTEGER_CST
1446 && TREE_CODE (TYPE_SIZE (field_type)) == INTEGER_CST
1448 && (! operand_equal_p (TYPE_SIZE (field_type), size, 0)
1450 && ! value_zerop (size_binop (TRUNC_MOD_EXPR, pos,
1451 bitsize_int (TYPE_ALIGN
1454 || (TYPE_ALIGN (record_type) != 0
1455 && TYPE_ALIGN (record_type) < TYPE_ALIGN (field_type))))
1457 DECL_BIT_FIELD (field_decl) = 1;
1458 DECL_SIZE (field_decl) = size;
1459 if (! packed && pos == 0)
1460 DECL_ALIGN (field_decl)
1461 = (TYPE_ALIGN (record_type) != 0
1462 ? MIN (TYPE_ALIGN (record_type), TYPE_ALIGN (field_type))
1463 : TYPE_ALIGN (field_type));
1466 DECL_PACKED (field_decl) = pos != 0 ? DECL_BIT_FIELD (field_decl) : packed;
1467 DECL_ALIGN (field_decl)
1468 = MAX (DECL_ALIGN (field_decl),
1469 DECL_BIT_FIELD (field_decl) ? 1
1470 : packed && TYPE_MODE (field_type) != BLKmode ? BITS_PER_UNIT
1471 : TYPE_ALIGN (field_type));
1475 /* We need to pass in the alignment the DECL is known to have.
1476 This is the lowest-order bit set in POS, but no more than
1477 the alignment of the record, if one is specified. Note
1478 that an alignment of 0 is taken as infinite. */
1479 unsigned int known_align;
1481 if (host_integerp (pos, 1))
1482 known_align = tree_low_cst (pos, 1) & - tree_low_cst (pos, 1);
1484 known_align = BITS_PER_UNIT;
1486 if (TYPE_ALIGN (record_type)
1487 && (known_align == 0 || known_align > TYPE_ALIGN (record_type)))
1488 known_align = TYPE_ALIGN (record_type);
1490 layout_decl (field_decl, known_align);
1491 SET_DECL_OFFSET_ALIGN (field_decl,
1492 host_integerp (pos, 1) ? BIGGEST_ALIGNMENT
1494 pos_from_bit (&DECL_FIELD_OFFSET (field_decl),
1495 &DECL_FIELD_BIT_OFFSET (field_decl),
1496 DECL_OFFSET_ALIGN (field_decl), pos);
1498 DECL_HAS_REP_P (field_decl) = 1;
1501 /* If the field type is passed by reference, we will have pointers to the
1502 field, so it is addressable. */
1503 if (must_pass_by_ref (field_type) || default_pass_by_ref (field_type))
1506 /* ??? For now, we say that any field of aggregate type is addressable
1507 because the front end may take 'Reference of it. */
1508 if (AGGREGATE_TYPE_P (field_type))
1511 /* Mark the decl as nonaddressable if it is indicated so semantically,
1512 meaning we won't ever attempt to take the address of the field.
1514 It may also be "technically" nonaddressable, meaning that even if we
1515 attempt to take the field's address we will actually get the address of a
1516 copy. This is the case for true bitfields, but the DECL_BIT_FIELD value
1517 we have at this point is not accurate enough, so we don't account for
1518 this here and let finish_record_type decide. */
1519 DECL_NONADDRESSABLE_P (field_decl) = ! addressable;
1524 /* Subroutine of previous function: return nonzero if EXP, ignoring any side
1525 effects, has the value of zero. */
1528 value_zerop (tree exp)
1530 if (TREE_CODE (exp) == COMPOUND_EXPR)
1531 return value_zerop (TREE_OPERAND (exp, 1));
1533 return integer_zerop (exp);
1536 /* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter,
1537 PARAM_TYPE is its type. READONLY is nonzero if the parameter is
1538 readonly (either an IN parameter or an address of a pass-by-ref
1542 create_param_decl (tree param_name, tree param_type, int readonly)
1544 tree param_decl = build_decl (PARM_DECL, param_name, param_type);
1546 /* Honor targetm.calls.promote_prototypes(), as not doing so can
1547 lead to various ABI violations. */
1548 if (targetm.calls.promote_prototypes (param_type)
1549 && (TREE_CODE (param_type) == INTEGER_TYPE
1550 || TREE_CODE (param_type) == ENUMERAL_TYPE)
1551 && TYPE_PRECISION (param_type) < TYPE_PRECISION (integer_type_node))
1553 /* We have to be careful about biased types here. Make a subtype
1554 of integer_type_node with the proper biasing. */
1555 if (TREE_CODE (param_type) == INTEGER_TYPE
1556 && TYPE_BIASED_REPRESENTATION_P (param_type))
1559 = copy_type (build_range_type (integer_type_node,
1560 TYPE_MIN_VALUE (param_type),
1561 TYPE_MAX_VALUE (param_type)));
1563 TYPE_BIASED_REPRESENTATION_P (param_type) = 1;
1566 param_type = integer_type_node;
1569 DECL_ARG_TYPE (param_decl) = param_type;
1570 DECL_ARG_TYPE_AS_WRITTEN (param_decl) = param_type;
1571 TREE_READONLY (param_decl) = readonly;
1575 /* Given a DECL and ATTR_LIST, process the listed attributes. */
1578 process_attributes (tree decl, struct attrib *attr_list)
1580 for (; attr_list; attr_list = attr_list->next)
1581 switch (attr_list->type)
1583 case ATTR_MACHINE_ATTRIBUTE:
1584 decl_attributes (&decl, tree_cons (attr_list->name, attr_list->arg,
1586 ATTR_FLAG_TYPE_IN_PLACE);
1589 case ATTR_LINK_ALIAS:
1590 TREE_STATIC (decl) = 1;
1591 assemble_alias (decl, attr_list->name);
1594 case ATTR_WEAK_EXTERNAL:
1596 declare_weak (decl);
1598 post_error ("?weak declarations not supported on this target",
1599 attr_list->error_point);
1602 case ATTR_LINK_SECTION:
1603 if (targetm.have_named_sections)
1605 DECL_SECTION_NAME (decl)
1606 = build_string (IDENTIFIER_LENGTH (attr_list->name),
1607 IDENTIFIER_POINTER (attr_list->name));
1608 DECL_COMMON (decl) = 0;
1611 post_error ("?section attributes are not supported for this target",
1612 attr_list->error_point);
1617 /* Add some pending elaborations on the list. */
1620 add_pending_elaborations (tree var_decl, tree var_init)
1623 Check_Elaboration_Code_Allowed (error_gnat_node);
1625 pending_elaborations
1626 = chainon (pending_elaborations, build_tree_list (var_decl, var_init));
1629 /* Obtain any pending elaborations and clear the old list. */
1632 get_pending_elaborations (void)
1634 /* Each thing added to the list went on the end; we want it on the
1636 tree result = TREE_CHAIN (pending_elaborations);
1638 TREE_CHAIN (pending_elaborations) = 0;
1642 /* Return true if VALUE is a multiple of FACTOR. FACTOR must be a power
1646 value_factor_p (tree value, int factor)
1648 if (host_integerp (value, 1))
1649 return tree_low_cst (value, 1) % factor == 0;
1651 if (TREE_CODE (value) == MULT_EXPR)
1652 return (value_factor_p (TREE_OPERAND (value, 0), factor)
1653 || value_factor_p (TREE_OPERAND (value, 1), factor));
1658 /* Given 2 consecutive field decls PREV_FIELD and CURR_FIELD, return true
1659 unless we can prove these 2 fields are laid out in such a way that no gap
1660 exist between the end of PREV_FIELD and the begining of CURR_FIELD. OFFSET
1661 is the distance in bits between the end of PREV_FIELD and the starting
1662 position of CURR_FIELD. It is ignored if null. */
1665 potential_alignment_gap (tree prev_field, tree curr_field, tree offset)
1667 /* If this is the first field of the record, there cannot be any gap */
1671 /* If the previous field is a union type, then return False: The only
1672 time when such a field is not the last field of the record is when
1673 there are other components at fixed positions after it (meaning there
1674 was a rep clause for every field), in which case we don't want the
1675 alignment constraint to override them. */
1676 if (TREE_CODE (TREE_TYPE (prev_field)) == QUAL_UNION_TYPE)
1679 /* If the distance between the end of prev_field and the begining of
1680 curr_field is constant, then there is a gap if the value of this
1681 constant is not null. */
1682 if (offset && host_integerp (offset, 1))
1683 return (!integer_zerop (offset));
1685 /* If the size and position of the previous field are constant,
1686 then check the sum of this size and position. There will be a gap
1687 iff it is not multiple of the current field alignment. */
1688 if (host_integerp (DECL_SIZE (prev_field), 1)
1689 && host_integerp (bit_position (prev_field), 1))
1690 return ((tree_low_cst (bit_position (prev_field), 1)
1691 + tree_low_cst (DECL_SIZE (prev_field), 1))
1692 % DECL_ALIGN (curr_field) != 0);
1694 /* If both the position and size of the previous field are multiples
1695 of the current field alignment, there can not be any gap. */
1696 if (value_factor_p (bit_position (prev_field), DECL_ALIGN (curr_field))
1697 && value_factor_p (DECL_SIZE (prev_field), DECL_ALIGN (curr_field)))
1700 /* Fallback, return that there may be a potential gap */
1704 /* Return nonzero if there are pending elaborations. */
1707 pending_elaborations_p (void)
1709 return TREE_CHAIN (pending_elaborations) != 0;
1712 /* Save a copy of the current pending elaboration list and make a new
1716 push_pending_elaborations (void)
1718 struct e_stack *p = (struct e_stack *) ggc_alloc (sizeof (struct e_stack));
1720 p->next = elist_stack;
1721 p->elab_list = pending_elaborations;
1723 pending_elaborations = build_tree_list (NULL_TREE, NULL_TREE);
1726 /* Pop the stack of pending elaborations. */
1729 pop_pending_elaborations (void)
1731 struct e_stack *p = elist_stack;
1733 pending_elaborations = p->elab_list;
1734 elist_stack = p->next;
1737 /* Return the current position in pending_elaborations so we can insert
1738 elaborations after that point. */
1741 get_elaboration_location (void)
1743 return tree_last (pending_elaborations);
1746 /* Insert the current elaborations after ELAB, which is in some elaboration
1750 insert_elaboration_list (tree elab)
1752 tree next = TREE_CHAIN (elab);
1754 if (TREE_CHAIN (pending_elaborations))
1756 TREE_CHAIN (elab) = TREE_CHAIN (pending_elaborations);
1757 TREE_CHAIN (tree_last (pending_elaborations)) = next;
1758 TREE_CHAIN (pending_elaborations) = 0;
1762 /* Returns a LABEL_DECL node for LABEL_NAME. */
1765 create_label_decl (tree label_name)
1767 tree label_decl = build_decl (LABEL_DECL, label_name, void_type_node);
1769 DECL_CONTEXT (label_decl) = current_function_decl;
1770 DECL_MODE (label_decl) = VOIDmode;
1771 DECL_SOURCE_LOCATION (label_decl) = input_location;
1776 /* Returns a FUNCTION_DECL node. SUBPROG_NAME is the name of the subprogram,
1777 ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE
1778 node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of
1779 PARM_DECL nodes chained through the TREE_CHAIN field).
1781 INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, and ATTR_LIST are used to set the
1782 appropriate fields in the FUNCTION_DECL. */
1785 create_subprog_decl (tree subprog_name,
1788 tree param_decl_list,
1792 struct attrib *attr_list)
1794 tree return_type = TREE_TYPE (subprog_type);
1795 tree subprog_decl = build_decl (FUNCTION_DECL, subprog_name, subprog_type);
1797 /* If this is a function nested inside an inlined external function, it
1798 means we aren't going to compile the outer function unless it is
1799 actually inlined, so do the same for us. */
1800 if (current_function_decl != 0 && DECL_INLINE (current_function_decl)
1801 && DECL_EXTERNAL (current_function_decl))
1804 DECL_EXTERNAL (subprog_decl) = extern_flag;
1805 TREE_PUBLIC (subprog_decl) = public_flag;
1806 DECL_INLINE (subprog_decl) = inline_flag;
1807 TREE_READONLY (subprog_decl) = TYPE_READONLY (subprog_type);
1808 TREE_THIS_VOLATILE (subprog_decl) = TYPE_VOLATILE (subprog_type);
1809 TREE_SIDE_EFFECTS (subprog_decl) = TYPE_VOLATILE (subprog_type);
1810 DECL_ARGUMENTS (subprog_decl) = param_decl_list;
1811 DECL_RESULT (subprog_decl) = build_decl (RESULT_DECL, 0, return_type);
1814 SET_DECL_ASSEMBLER_NAME (subprog_decl, asm_name);
1816 process_attributes (subprog_decl, attr_list);
1818 /* Add this decl to the current binding level. */
1819 subprog_decl = pushdecl (subprog_decl);
1821 /* Output the assembler code and/or RTL for the declaration. */
1822 rest_of_decl_compilation (subprog_decl, 0, global_bindings_p (), 0);
1824 return subprog_decl;
1827 /* Count how deep we are into nested functions. This is because
1828 we shouldn't call the backend function context routines unless we
1829 are in a nested function. */
1831 static int function_nesting_depth;
1833 /* Set up the framework for generating code for SUBPROG_DECL, a subprogram
1834 body. This routine needs to be invoked before processing the declarations
1835 appearing in the subprogram. */
1838 begin_subprog_body (tree subprog_decl)
1840 tree param_decl_list;
1844 if (function_nesting_depth++ != 0)
1845 push_function_context ();
1847 announce_function (subprog_decl);
1849 /* Make this field nonzero so further routines know that this is not
1850 tentative. error_mark_node is replaced below (in poplevel) with the
1852 DECL_INITIAL (subprog_decl) = error_mark_node;
1854 /* This function exists in static storage. This does not mean `static' in
1856 TREE_STATIC (subprog_decl) = 1;
1858 /* Enter a new binding level. */
1859 current_function_decl = subprog_decl;
1862 /* Push all the PARM_DECL nodes onto the current scope (i.e. the scope of the
1863 subprogram body) so that they can be recognized as local variables in the
1866 The list of PARM_DECL nodes is stored in the right order in
1867 DECL_ARGUMENTS. Since ..._DECL nodes get stored in the reverse order in
1868 which they are transmitted to `pushdecl' we need to reverse the list of
1869 PARM_DECLs if we want it to be stored in the right order. The reason why
1870 we want to make sure the PARM_DECLs are stored in the correct order is
1871 that this list will be retrieved in a few lines with a call to `getdecl'
1872 to store it back into the DECL_ARGUMENTS field. */
1873 param_decl_list = nreverse (DECL_ARGUMENTS (subprog_decl));
1875 for (param_decl = param_decl_list; param_decl; param_decl = next_param)
1877 next_param = TREE_CHAIN (param_decl);
1878 TREE_CHAIN (param_decl) = NULL;
1879 pushdecl (param_decl);
1882 /* Store back the PARM_DECL nodes. They appear in the right order. */
1883 DECL_ARGUMENTS (subprog_decl) = getdecls ();
1885 init_function_start (subprog_decl);
1886 expand_function_start (subprog_decl, 0);
1888 /* If this function is `main', emit a call to `__main'
1889 to run global initializers, etc. */
1890 if (DECL_ASSEMBLER_NAME (subprog_decl) != 0
1891 && MAIN_NAME_P (DECL_ASSEMBLER_NAME (subprog_decl))
1892 && DECL_CONTEXT (subprog_decl) == NULL_TREE)
1893 expand_main_function ();
1896 /* Finish the definition of the current subprogram and compile it all the way
1897 to assembler language output. */
1900 end_subprog_body (void)
1906 BLOCK_SUPERCONTEXT (DECL_INITIAL (current_function_decl))
1907 = current_function_decl;
1909 /* Mark the RESULT_DECL as being in this subprogram. */
1910 DECL_CONTEXT (DECL_RESULT (current_function_decl)) = current_function_decl;
1912 expand_function_end ();
1914 /* If this is a nested function, push a new GC context. That will keep
1915 local variables on the stack from being collected while we're doing
1916 the compilation of this function. */
1917 if (function_nesting_depth > 1)
1918 ggc_push_context ();
1920 /* If we're only annotating types, don't actually compile this
1922 if (!type_annotate_only)
1923 rest_of_compilation (current_function_decl);
1925 if (function_nesting_depth > 1)
1928 /* Throw away any VAR_DECLs we made for OUT parameters; they must
1929 not be seen when we call this function and will be in
1930 unallocated memory anyway. */
1931 for (cico_list = TYPE_CI_CO_LIST (TREE_TYPE (current_function_decl));
1932 cico_list != 0; cico_list = TREE_CHAIN (cico_list))
1933 TREE_VALUE (cico_list) = 0;
1935 if (DECL_STRUCT_FUNCTION (current_function_decl) == 0)
1937 /* Throw away DECL_RTL in any PARM_DECLs unless this function
1938 was saved for inline, in which case the DECL_RTLs are in
1939 preserved memory. */
1940 for (decl = DECL_ARGUMENTS (current_function_decl);
1941 decl != 0; decl = TREE_CHAIN (decl))
1943 SET_DECL_RTL (decl, 0);
1944 DECL_INCOMING_RTL (decl) = 0;
1947 /* Similarly, discard DECL_RTL of the return value. */
1948 SET_DECL_RTL (DECL_RESULT (current_function_decl), 0);
1950 /* But DECL_INITIAL must remain nonzero so we know this
1951 was an actual function definition unless toplev.c decided not
1953 if (DECL_INITIAL (current_function_decl) != 0)
1954 DECL_INITIAL (current_function_decl) = error_mark_node;
1956 DECL_ARGUMENTS (current_function_decl) = 0;
1959 /* If we are not at the bottom of the function nesting stack, pop up to
1960 the containing function. Otherwise show we aren't in any function. */
1961 if (--function_nesting_depth != 0)
1962 pop_function_context ();
1964 current_function_decl = 0;
1967 /* Return a definition for a builtin function named NAME and whose data type
1968 is TYPE. TYPE should be a function type with argument types.
1969 FUNCTION_CODE tells later passes how to compile calls to this function.
1970 See tree.h for its possible values.
1972 If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME,
1973 the name to be called if we can't opencode the function. If
1974 ATTRS is nonzero, use that for the function attribute list. */
1977 builtin_function (const char *name,
1980 enum built_in_class class,
1981 const char *library_name,
1984 tree decl = build_decl (FUNCTION_DECL, get_identifier (name), type);
1986 DECL_EXTERNAL (decl) = 1;
1987 TREE_PUBLIC (decl) = 1;
1989 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name));
1992 DECL_BUILT_IN_CLASS (decl) = class;
1993 DECL_FUNCTION_CODE (decl) = function_code;
1995 decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
1999 /* Return an integer type with the number of bits of precision given by
2000 PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise
2001 it is a signed type. */
2004 gnat_type_for_size (unsigned precision, int unsignedp)
2009 if (precision <= 2 * MAX_BITS_PER_WORD
2010 && signed_and_unsigned_types[precision][unsignedp] != 0)
2011 return signed_and_unsigned_types[precision][unsignedp];
2014 t = make_unsigned_type (precision);
2016 t = make_signed_type (precision);
2018 if (precision <= 2 * MAX_BITS_PER_WORD)
2019 signed_and_unsigned_types[precision][unsignedp] = t;
2021 if (TYPE_NAME (t) == 0)
2023 sprintf (type_name, "%sSIGNED_%d", unsignedp ? "UN" : "", precision);
2024 TYPE_NAME (t) = get_identifier (type_name);
2030 /* Likewise for floating-point types. */
2033 float_type_for_precision (int precision, enum machine_mode mode)
2038 if (float_types[(int) mode] != 0)
2039 return float_types[(int) mode];
2041 float_types[(int) mode] = t = make_node (REAL_TYPE);
2042 TYPE_PRECISION (t) = precision;
2045 if (TYPE_MODE (t) != mode)
2048 if (TYPE_NAME (t) == 0)
2050 sprintf (type_name, "FLOAT_%d", precision);
2051 TYPE_NAME (t) = get_identifier (type_name);
2057 /* Return a data type that has machine mode MODE. UNSIGNEDP selects
2058 an unsigned type; otherwise a signed type is returned. */
2061 gnat_type_for_mode (enum machine_mode mode, int unsignedp)
2063 if (GET_MODE_CLASS (mode) == MODE_FLOAT)
2064 return float_type_for_precision (GET_MODE_PRECISION (mode), mode);
2066 return gnat_type_for_size (GET_MODE_BITSIZE (mode), unsignedp);
2069 /* Return the unsigned version of a TYPE_NODE, a scalar type. */
2072 gnat_unsigned_type (tree type_node)
2074 tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 1);
2076 if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
2078 type = copy_node (type);
2079 TREE_TYPE (type) = type_node;
2081 else if (TREE_TYPE (type_node) != 0
2082 && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
2083 && TYPE_MODULAR_P (TREE_TYPE (type_node)))
2085 type = copy_node (type);
2086 TREE_TYPE (type) = TREE_TYPE (type_node);
2092 /* Return the signed version of a TYPE_NODE, a scalar type. */
2095 gnat_signed_type (tree type_node)
2097 tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 0);
2099 if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node))
2101 type = copy_node (type);
2102 TREE_TYPE (type) = type_node;
2104 else if (TREE_TYPE (type_node) != 0
2105 && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE
2106 && TYPE_MODULAR_P (TREE_TYPE (type_node)))
2108 type = copy_node (type);
2109 TREE_TYPE (type) = TREE_TYPE (type_node);
2115 /* Return a type the same as TYPE except unsigned or signed according to
2119 gnat_signed_or_unsigned_type (int unsignedp, tree type)
2121 if (! INTEGRAL_TYPE_P (type) || TYPE_UNSIGNED (type) == unsignedp)
2124 return gnat_type_for_size (TYPE_PRECISION (type), unsignedp);
2127 /* EXP is an expression for the size of an object. If this size contains
2128 discriminant references, replace them with the maximum (if MAX_P) or
2129 minimum (if ! MAX_P) possible value of the discriminant. */
2132 max_size (tree exp, int max_p)
2134 enum tree_code code = TREE_CODE (exp);
2135 tree type = TREE_TYPE (exp);
2137 switch (TREE_CODE_CLASS (code))
2144 if (code == TREE_LIST)
2145 return tree_cons (TREE_PURPOSE (exp),
2146 max_size (TREE_VALUE (exp), max_p),
2147 TREE_CHAIN (exp) != 0
2148 ? max_size (TREE_CHAIN (exp), max_p) : 0);
2152 /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to
2153 modify. Otherwise, we treat it like a variable. */
2154 if (! CONTAINS_PLACEHOLDER_P (exp))
2157 type = TREE_TYPE (TREE_OPERAND (exp, 1));
2159 max_size (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type), 1);
2162 return max_p ? size_one_node : size_zero_node;
2167 switch (TREE_CODE_LENGTH (code))
2170 if (code == NON_LVALUE_EXPR)
2171 return max_size (TREE_OPERAND (exp, 0), max_p);
2174 fold (build1 (code, type,
2175 max_size (TREE_OPERAND (exp, 0),
2176 code == NEGATE_EXPR ? ! max_p : max_p)));
2179 if (code == RTL_EXPR)
2181 else if (code == COMPOUND_EXPR)
2182 return max_size (TREE_OPERAND (exp, 1), max_p);
2185 tree lhs = max_size (TREE_OPERAND (exp, 0), max_p);
2186 tree rhs = max_size (TREE_OPERAND (exp, 1),
2187 code == MINUS_EXPR ? ! max_p : max_p);
2189 /* Special-case wanting the maximum value of a MIN_EXPR.
2190 In that case, if one side overflows, return the other.
2191 sizetype is signed, but we know sizes are non-negative.
2192 Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS
2193 overflowing or the maximum possible value and the RHS
2195 if (max_p && code == MIN_EXPR && TREE_OVERFLOW (rhs))
2197 else if (max_p && code == MIN_EXPR && TREE_OVERFLOW (lhs))
2199 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
2200 && ((TREE_CONSTANT (lhs) && TREE_OVERFLOW (lhs))
2201 || operand_equal_p (lhs, TYPE_MAX_VALUE (type), 0))
2202 && ! TREE_CONSTANT (rhs))
2205 return fold (build (code, type, lhs, rhs));
2209 if (code == SAVE_EXPR)
2211 else if (code == COND_EXPR)
2212 return fold (build (MAX_EXPR, type,
2213 max_size (TREE_OPERAND (exp, 1), max_p),
2214 max_size (TREE_OPERAND (exp, 2), max_p)));
2215 else if (code == CALL_EXPR && TREE_OPERAND (exp, 1) != 0)
2216 return build (CALL_EXPR, type, TREE_OPERAND (exp, 0),
2217 max_size (TREE_OPERAND (exp, 1), max_p));
2224 /* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE.
2225 EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs.
2226 Return a constructor for the template. */
2229 build_template (tree template_type, tree array_type, tree expr)
2231 tree template_elts = NULL_TREE;
2232 tree bound_list = NULL_TREE;
2235 if (TREE_CODE (array_type) == RECORD_TYPE
2236 && (TYPE_IS_PADDING_P (array_type)
2237 || TYPE_LEFT_JUSTIFIED_MODULAR_P (array_type)))
2238 array_type = TREE_TYPE (TYPE_FIELDS (array_type));
2240 if (TREE_CODE (array_type) == ARRAY_TYPE
2241 || (TREE_CODE (array_type) == INTEGER_TYPE
2242 && TYPE_HAS_ACTUAL_BOUNDS_P (array_type)))
2243 bound_list = TYPE_ACTUAL_BOUNDS (array_type);
2245 /* First make the list for a CONSTRUCTOR for the template. Go down the
2246 field list of the template instead of the type chain because this
2247 array might be an Ada array of arrays and we can't tell where the
2248 nested arrays stop being the underlying object. */
2250 for (field = TYPE_FIELDS (template_type); field;
2252 ? (bound_list = TREE_CHAIN (bound_list))
2253 : (array_type = TREE_TYPE (array_type))),
2254 field = TREE_CHAIN (TREE_CHAIN (field)))
2256 tree bounds, min, max;
2258 /* If we have a bound list, get the bounds from there. Likewise
2259 for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with
2260 DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template.
2261 This will give us a maximum range. */
2262 if (bound_list != 0)
2263 bounds = TREE_VALUE (bound_list);
2264 else if (TREE_CODE (array_type) == ARRAY_TYPE)
2265 bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type));
2266 else if (expr != 0 && TREE_CODE (expr) == PARM_DECL
2267 && DECL_BY_COMPONENT_PTR_P (expr))
2268 bounds = TREE_TYPE (field);
2272 min = convert (TREE_TYPE (TREE_CHAIN (field)), TYPE_MIN_VALUE (bounds));
2273 max = convert (TREE_TYPE (field), TYPE_MAX_VALUE (bounds));
2275 /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must
2276 substitute it from OBJECT. */
2277 min = SUBSTITUTE_PLACEHOLDER_IN_EXPR (min, expr);
2278 max = SUBSTITUTE_PLACEHOLDER_IN_EXPR (max, expr);
2280 template_elts = tree_cons (TREE_CHAIN (field), max,
2281 tree_cons (field, min, template_elts));
2284 return gnat_build_constructor (template_type, nreverse (template_elts));
2287 /* Build a VMS descriptor from a Mechanism_Type, which must specify
2288 a descriptor type, and the GCC type of an object. Each FIELD_DECL
2289 in the type contains in its DECL_INITIAL the expression to use when
2290 a constructor is made for the type. GNAT_ENTITY is a gnat node used
2291 to print out an error message if the mechanism cannot be applied to
2292 an object of that type and also for the name. */
2295 build_vms_descriptor (tree type, Mechanism_Type mech, Entity_Id gnat_entity)
2297 tree record_type = make_node (RECORD_TYPE);
2298 tree field_list = 0;
2307 /* If TYPE is an unconstrained array, use the underlying array type. */
2308 if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
2309 type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type))));
2311 /* If this is an array, compute the number of dimensions in the array,
2312 get the index types, and point to the inner type. */
2313 if (TREE_CODE (type) != ARRAY_TYPE)
2316 for (ndim = 1, inner_type = type;
2317 TREE_CODE (TREE_TYPE (inner_type)) == ARRAY_TYPE
2318 && TYPE_MULTI_ARRAY_P (TREE_TYPE (inner_type));
2319 ndim++, inner_type = TREE_TYPE (inner_type))
2322 idx_arr = (tree *) alloca (ndim * sizeof (tree));
2324 if (mech != By_Descriptor_NCA
2325 && TREE_CODE (type) == ARRAY_TYPE && TYPE_CONVENTION_FORTRAN_P (type))
2326 for (i = ndim - 1, inner_type = type;
2328 i--, inner_type = TREE_TYPE (inner_type))
2329 idx_arr[i] = TYPE_DOMAIN (inner_type);
2331 for (i = 0, inner_type = type;
2333 i++, inner_type = TREE_TYPE (inner_type))
2334 idx_arr[i] = TYPE_DOMAIN (inner_type);
2336 /* Now get the DTYPE value. */
2337 switch (TREE_CODE (type))
2341 if (TYPE_VAX_FLOATING_POINT_P (type))
2342 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2355 switch (GET_MODE_BITSIZE (TYPE_MODE (type)))
2358 dtype = TYPE_UNSIGNED (type) ? 2 : 6;
2361 dtype = TYPE_UNSIGNED (type) ? 3 : 7;
2364 dtype = TYPE_UNSIGNED (type) ? 4 : 8;
2367 dtype = TYPE_UNSIGNED (type) ? 5 : 9;
2370 dtype = TYPE_UNSIGNED (type) ? 25 : 26;
2376 dtype = GET_MODE_BITSIZE (TYPE_MODE (type)) == 32 ? 52 : 53;
2380 if (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE
2381 && TYPE_VAX_FLOATING_POINT_P (type))
2382 switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1))
2394 dtype = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) == 32 ? 54: 55;
2405 /* Get the CLASS value. */
2408 case By_Descriptor_A:
2411 case By_Descriptor_NCA:
2414 case By_Descriptor_SB:
2421 /* Make the type for a descriptor for VMS. The first four fields
2422 are the same for all types. */
2425 = chainon (field_list,
2426 make_descriptor_field
2427 ("LENGTH", gnat_type_for_size (16, 1), record_type,
2428 size_in_bytes (mech == By_Descriptor_A ? inner_type : type)));
2430 field_list = chainon (field_list,
2431 make_descriptor_field ("DTYPE",
2432 gnat_type_for_size (8, 1),
2433 record_type, size_int (dtype)));
2434 field_list = chainon (field_list,
2435 make_descriptor_field ("CLASS",
2436 gnat_type_for_size (8, 1),
2437 record_type, size_int (class)));
2440 = chainon (field_list,
2441 make_descriptor_field ("POINTER",
2442 build_pointer_type (type),
2445 build_pointer_type (type),
2446 build (PLACEHOLDER_EXPR,
2452 case By_Descriptor_S:
2455 case By_Descriptor_SB:
2457 = chainon (field_list,
2458 make_descriptor_field
2459 ("SB_L1", gnat_type_for_size (32, 1), record_type,
2460 TREE_CODE (type) == ARRAY_TYPE
2461 ? TYPE_MIN_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2463 = chainon (field_list,
2464 make_descriptor_field
2465 ("SB_L2", gnat_type_for_size (32, 1), record_type,
2466 TREE_CODE (type) == ARRAY_TYPE
2467 ? TYPE_MAX_VALUE (TYPE_DOMAIN (type)) : size_zero_node));
2470 case By_Descriptor_A:
2471 case By_Descriptor_NCA:
2472 field_list = chainon (field_list,
2473 make_descriptor_field ("SCALE",
2474 gnat_type_for_size (8, 1),
2478 field_list = chainon (field_list,
2479 make_descriptor_field ("DIGITS",
2480 gnat_type_for_size (8, 1),
2485 = chainon (field_list,
2486 make_descriptor_field
2487 ("AFLAGS", gnat_type_for_size (8, 1), record_type,
2488 size_int (mech == By_Descriptor_NCA
2490 /* Set FL_COLUMN, FL_COEFF, and FL_BOUNDS. */
2491 : (TREE_CODE (type) == ARRAY_TYPE
2492 && TYPE_CONVENTION_FORTRAN_P (type)
2495 field_list = chainon (field_list,
2496 make_descriptor_field ("DIMCT",
2497 gnat_type_for_size (8, 1),
2501 field_list = chainon (field_list,
2502 make_descriptor_field ("ARSIZE",
2503 gnat_type_for_size (32, 1),
2505 size_in_bytes (type)));
2507 /* Now build a pointer to the 0,0,0... element. */
2508 tem = build (PLACEHOLDER_EXPR, type);
2509 for (i = 0, inner_type = type; i < ndim;
2510 i++, inner_type = TREE_TYPE (inner_type))
2511 tem = build (ARRAY_REF, TREE_TYPE (inner_type), tem,
2512 convert (TYPE_DOMAIN (inner_type), size_zero_node));
2515 = chainon (field_list,
2516 make_descriptor_field
2517 ("A0", build_pointer_type (inner_type), record_type,
2518 build1 (ADDR_EXPR, build_pointer_type (inner_type), tem)));
2520 /* Next come the addressing coefficients. */
2522 for (i = 0; i < ndim; i++)
2526 = size_binop (MULT_EXPR, tem,
2527 size_binop (PLUS_EXPR,
2528 size_binop (MINUS_EXPR,
2529 TYPE_MAX_VALUE (idx_arr[i]),
2530 TYPE_MIN_VALUE (idx_arr[i])),
2533 fname[0] = (mech == By_Descriptor_NCA ? 'S' : 'M');
2534 fname[1] = '0' + i, fname[2] = 0;
2536 = chainon (field_list,
2537 make_descriptor_field (fname,
2538 gnat_type_for_size (32, 1),
2539 record_type, idx_length));
2541 if (mech == By_Descriptor_NCA)
2545 /* Finally here are the bounds. */
2546 for (i = 0; i < ndim; i++)
2550 fname[0] = 'L', fname[1] = '0' + i, fname[2] = 0;
2552 = chainon (field_list,
2553 make_descriptor_field
2554 (fname, gnat_type_for_size (32, 1), record_type,
2555 TYPE_MIN_VALUE (idx_arr[i])));
2559 = chainon (field_list,
2560 make_descriptor_field
2561 (fname, gnat_type_for_size (32, 1), record_type,
2562 TYPE_MAX_VALUE (idx_arr[i])));
2567 post_error ("unsupported descriptor type for &", gnat_entity);
2570 finish_record_type (record_type, field_list, 0, 1);
2571 pushdecl (build_decl (TYPE_DECL, create_concat_name (gnat_entity, "DESC"),
2577 /* Utility routine for above code to make a field. */
2580 make_descriptor_field (const char *name, tree type,
2581 tree rec_type, tree initial)
2584 = create_field_decl (get_identifier (name), type, rec_type, 0, 0, 0, 0);
2586 DECL_INITIAL (field) = initial;
2590 /* Build a type to be used to represent an aliased object whose nominal
2591 type is an unconstrained array. This consists of a RECORD_TYPE containing
2592 a field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an
2593 ARRAY_TYPE. If ARRAY_TYPE is that of the unconstrained array, this
2594 is used to represent an arbitrary unconstrained object. Use NAME
2595 as the name of the record. */
2598 build_unc_object_type (tree template_type, tree object_type, tree name)
2600 tree type = make_node (RECORD_TYPE);
2601 tree template_field = create_field_decl (get_identifier ("BOUNDS"),
2602 template_type, type, 0, 0, 0, 1);
2603 tree array_field = create_field_decl (get_identifier ("ARRAY"), object_type,
2606 TYPE_NAME (type) = name;
2607 TYPE_CONTAINS_TEMPLATE_P (type) = 1;
2608 finish_record_type (type,
2609 chainon (chainon (NULL_TREE, template_field),
2616 /* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE. In
2617 the normal case this is just two adjustments, but we have more to do
2618 if NEW is an UNCONSTRAINED_ARRAY_TYPE. */
2621 update_pointer_to (tree old_type, tree new_type)
2623 tree ptr = TYPE_POINTER_TO (old_type);
2624 tree ref = TYPE_REFERENCE_TO (old_type);
2627 /* If this is the main variant, process all the other variants first. */
2628 if (TYPE_MAIN_VARIANT (old_type) == old_type)
2629 for (type = TYPE_NEXT_VARIANT (old_type); type != 0;
2630 type = TYPE_NEXT_VARIANT (type))
2631 update_pointer_to (type, new_type);
2633 /* If no pointer or reference, we are done. */
2634 if (ptr == 0 && ref == 0)
2637 /* Merge the old type qualifiers in the new type.
2639 Each old variant has qualifiers for specific reasons, and the new
2640 designated type as well. Each set of qualifiers represents useful
2641 information grabbed at some point, and merging the two simply unifies
2642 these inputs into the final type description.
2644 Consider for instance a volatile type frozen after an access to constant
2645 type designating it. After the designated type freeze, we get here with a
2646 volatile new_type and a dummy old_type with a readonly variant, created
2647 when the access type was processed. We shall make a volatile and readonly
2648 designated type, because that's what it really is.
2650 We might also get here for a non-dummy old_type variant with different
2651 qualifiers than the new_type ones, for instance in some cases of pointers
2652 to private record type elaboration (see the comments around the call to
2653 this routine from gnat_to_gnu_entity/E_Access_Type). We have to merge the
2654 qualifiers in thoses cases too, to avoid accidentally discarding the
2655 initial set, and will often end up with old_type == new_type then. */
2656 new_type = build_qualified_type (new_type,
2657 TYPE_QUALS (old_type)
2658 | TYPE_QUALS (new_type));
2660 /* If the new type and the old one are identical, there is nothing to
2662 if (old_type == new_type)
2665 /* Otherwise, first handle the simple case. */
2666 if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE)
2668 TYPE_POINTER_TO (new_type) = ptr;
2669 TYPE_REFERENCE_TO (new_type) = ref;
2671 for (; ptr; ptr = TYPE_NEXT_PTR_TO (ptr))
2673 TREE_TYPE (ptr) = new_type;
2675 if (TYPE_NAME (ptr) != 0
2676 && TREE_CODE (TYPE_NAME (ptr)) == TYPE_DECL
2677 && TREE_CODE (new_type) != ENUMERAL_TYPE)
2678 rest_of_decl_compilation (TYPE_NAME (ptr), NULL,
2679 global_bindings_p (), 0);
2682 for (; ref; ref = TYPE_NEXT_PTR_TO (ref))
2684 TREE_TYPE (ref) = new_type;
2686 if (TYPE_NAME (ref) != 0
2687 && TREE_CODE (TYPE_NAME (ref)) == TYPE_DECL
2688 && TREE_CODE (new_type) != ENUMERAL_TYPE)
2689 rest_of_decl_compilation (TYPE_NAME (ref), NULL,
2690 global_bindings_p (), 0);
2694 /* Now deal with the unconstrained array case. In this case the "pointer"
2695 is actually a RECORD_TYPE where the types of both fields are
2696 pointers to void. In that case, copy the field list from the
2697 old type to the new one and update the fields' context. */
2698 else if (TREE_CODE (ptr) != RECORD_TYPE || ! TYPE_IS_FAT_POINTER_P (ptr))
2703 tree new_obj_rec = TYPE_OBJECT_RECORD_TYPE (new_type);
2708 TYPE_FIELDS (ptr) = TYPE_FIELDS (TYPE_POINTER_TO (new_type));
2709 DECL_CONTEXT (TYPE_FIELDS (ptr)) = ptr;
2710 DECL_CONTEXT (TREE_CHAIN (TYPE_FIELDS (ptr))) = ptr;
2712 /* Rework the PLACEHOLDER_EXPR inside the reference to the
2715 ??? This is now the only use of gnat_substitute_in_type, which
2716 is now a very "heavy" routine to do this, so it should be replaced
2718 ptr_temp_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (ptr)));
2719 new_ref = build (COMPONENT_REF, ptr_temp_type,
2720 build (PLACEHOLDER_EXPR, ptr),
2721 TREE_CHAIN (TYPE_FIELDS (ptr)));
2724 (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))),
2725 gnat_substitute_in_type (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))),
2726 TREE_CHAIN (TYPE_FIELDS (ptr)), new_ref));
2728 for (var = TYPE_MAIN_VARIANT (ptr); var; var = TYPE_NEXT_VARIANT (var))
2729 SET_TYPE_UNCONSTRAINED_ARRAY (var, new_type);
2731 TYPE_POINTER_TO (new_type) = TYPE_REFERENCE_TO (new_type)
2732 = TREE_TYPE (new_type) = ptr;
2734 /* Now handle updating the allocation record, what the thin pointer
2735 points to. Update all pointers from the old record into the new
2736 one, update the types of the fields, and recompute the size. */
2738 update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), new_obj_rec);
2740 TREE_TYPE (TYPE_FIELDS (new_obj_rec)) = TREE_TYPE (ptr_temp_type);
2741 TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
2742 = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr)));
2743 DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
2744 = TYPE_SIZE (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))));
2745 DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))
2746 = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))));
2748 TYPE_SIZE (new_obj_rec)
2749 = size_binop (PLUS_EXPR,
2750 DECL_SIZE (TYPE_FIELDS (new_obj_rec)),
2751 DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))));
2752 TYPE_SIZE_UNIT (new_obj_rec)
2753 = size_binop (PLUS_EXPR,
2754 DECL_SIZE_UNIT (TYPE_FIELDS (new_obj_rec)),
2755 DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))));
2756 rest_of_type_compilation (ptr, global_bindings_p ());
2760 /* Convert a pointer to a constrained array into a pointer to a fat
2761 pointer. This involves making or finding a template. */
2764 convert_to_fat_pointer (tree type, tree expr)
2766 tree template_type = TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type))));
2767 tree template, template_addr;
2768 tree etype = TREE_TYPE (expr);
2770 /* If EXPR is a constant of zero, we make a fat pointer that has a null
2771 pointer to the template and array. */
2772 if (integer_zerop (expr))
2774 gnat_build_constructor
2776 tree_cons (TYPE_FIELDS (type),
2777 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
2778 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
2779 convert (build_pointer_type (template_type),
2783 /* If EXPR is a thin pointer, make the template and data from the record. */
2785 else if (TYPE_THIN_POINTER_P (etype))
2787 tree fields = TYPE_FIELDS (TREE_TYPE (etype));
2789 expr = save_expr (expr);
2790 if (TREE_CODE (expr) == ADDR_EXPR)
2791 expr = TREE_OPERAND (expr, 0);
2793 expr = build1 (INDIRECT_REF, TREE_TYPE (etype), expr);
2795 template = build_component_ref (expr, NULL_TREE, fields, 0);
2796 expr = build_unary_op (ADDR_EXPR, NULL_TREE,
2797 build_component_ref (expr, NULL_TREE,
2798 TREE_CHAIN (fields), 0));
2801 /* Otherwise, build the constructor for the template. */
2802 template = build_template (template_type, TREE_TYPE (etype), expr);
2804 template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template);
2806 /* The result is a CONSTRUCTOR for the fat pointer.
2808 If expr is an argument of a foreign convention subprogram, the type it
2809 points to is directly the component type. In this case, the expression
2810 type may not match the corresponding FIELD_DECL type at this point, so we
2811 call "convert" here to fix that up if necessary. This type consistency is
2812 required, for instance because it ensures that possible later folding of
2813 component_refs against this constructor always yields something of the
2814 same type as the initial reference.
2816 Note that the call to "build_template" above is still fine, because it
2817 will only refer to the provided template_type in this case. */
2819 gnat_build_constructor
2820 (type, tree_cons (TYPE_FIELDS (type),
2821 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
2822 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
2823 template_addr, NULL_TREE)));
2826 /* Convert to a thin pointer type, TYPE. The only thing we know how to convert
2827 is something that is a fat pointer, so convert to it first if it EXPR
2828 is not already a fat pointer. */
2831 convert_to_thin_pointer (tree type, tree expr)
2833 if (! TYPE_FAT_POINTER_P (TREE_TYPE (expr)))
2835 = convert_to_fat_pointer
2836 (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))), expr);
2838 /* We get the pointer to the data and use a NOP_EXPR to make it the
2841 = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (TREE_TYPE (expr)), 0);
2842 expr = build1 (NOP_EXPR, type, expr);
2847 /* Create an expression whose value is that of EXPR,
2848 converted to type TYPE. The TREE_TYPE of the value
2849 is always TYPE. This function implements all reasonable
2850 conversions; callers should filter out those that are
2851 not permitted by the language being compiled. */
2854 convert (tree type, tree expr)
2856 enum tree_code code = TREE_CODE (type);
2857 tree etype = TREE_TYPE (expr);
2858 enum tree_code ecode = TREE_CODE (etype);
2861 /* If EXPR is already the right type, we are done. */
2864 /* If we're converting between two aggregate types that have the same main
2865 variant, just make a NOP_EXPR. */
2866 else if (AGGREGATE_TYPE_P (type)
2867 && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype))
2868 return build1 (NOP_EXPR, type, expr);
2870 /* If the input type has padding, remove it by doing a component reference
2871 to the field. If the output type has padding, make a constructor
2872 to build the record. If both input and output have padding and are
2873 of variable size, do this as an unchecked conversion. */
2874 else if (ecode == RECORD_TYPE && code == RECORD_TYPE
2875 && TYPE_IS_PADDING_P (type) && TYPE_IS_PADDING_P (etype)
2876 && (! TREE_CONSTANT (TYPE_SIZE (type))
2877 || ! TREE_CONSTANT (TYPE_SIZE (etype))))
2879 else if (ecode == RECORD_TYPE && TYPE_IS_PADDING_P (etype))
2881 /* If we have just converted to this padded type, just get
2882 the inner expression. */
2883 if (TREE_CODE (expr) == CONSTRUCTOR
2884 && CONSTRUCTOR_ELTS (expr) != 0
2885 && TREE_PURPOSE (CONSTRUCTOR_ELTS (expr)) == TYPE_FIELDS (etype))
2886 return TREE_VALUE (CONSTRUCTOR_ELTS (expr));
2888 return convert (type, build_component_ref (expr, NULL_TREE,
2889 TYPE_FIELDS (etype), 0));
2891 else if (code == RECORD_TYPE && TYPE_IS_PADDING_P (type))
2893 /* If we previously converted from another type and our type is
2894 of variable size, remove the conversion to avoid the need for
2895 variable-size temporaries. */
2896 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
2897 && ! TREE_CONSTANT (TYPE_SIZE (type)))
2898 expr = TREE_OPERAND (expr, 0);
2900 /* If we are just removing the padding from expr, convert the original
2901 object if we have variable size. That will avoid the need
2902 for some variable-size temporaries. */
2903 if (TREE_CODE (expr) == COMPONENT_REF
2904 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE
2905 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (expr, 0)))
2906 && ! TREE_CONSTANT (TYPE_SIZE (type)))
2907 return convert (type, TREE_OPERAND (expr, 0));
2909 /* If the result type is a padded type with a self-referentially-sized
2910 field and the expression type is a record, do this as an
2911 unchecked converstion. */
2912 else if (TREE_CODE (etype) == RECORD_TYPE
2913 && CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type))))
2914 return unchecked_convert (type, expr, 0);
2918 gnat_build_constructor (type,
2919 tree_cons (TYPE_FIELDS (type),
2921 (TYPE_FIELDS (type)),
2926 /* If the input is a biased type, adjust first. */
2927 if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype))
2928 return convert (type, fold (build (PLUS_EXPR, TREE_TYPE (etype),
2929 fold (build1 (GNAT_NOP_EXPR,
2930 TREE_TYPE (etype), expr)),
2931 TYPE_MIN_VALUE (etype))));
2933 /* If the input is a left-justified modular type, we need to extract
2934 the actual object before converting it to any other type with the
2935 exception of an unconstrained array. */
2936 if (ecode == RECORD_TYPE && TYPE_LEFT_JUSTIFIED_MODULAR_P (etype)
2937 && code != UNCONSTRAINED_ARRAY_TYPE)
2938 return convert (type, build_component_ref (expr, NULL_TREE,
2939 TYPE_FIELDS (etype), 0));
2941 /* If converting to a type that contains a template, convert to the data
2942 type and then build the template. */
2943 if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type))
2945 tree obj_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type)));
2947 /* If the source already has a template, get a reference to the
2948 associated array only, as we are going to rebuild a template
2949 for the target type anyway. */
2950 expr = maybe_unconstrained_array (expr);
2953 gnat_build_constructor
2955 tree_cons (TYPE_FIELDS (type),
2956 build_template (TREE_TYPE (TYPE_FIELDS (type)),
2957 obj_type, NULL_TREE),
2958 tree_cons (TREE_CHAIN (TYPE_FIELDS (type)),
2959 convert (obj_type, expr), NULL_TREE)));
2962 /* There are some special cases of expressions that we process
2964 switch (TREE_CODE (expr))
2969 case TRANSFORM_EXPR:
2971 /* Just set its type here. For TRANSFORM_EXPR, we will do the actual
2972 conversion in gnat_expand_expr. NULL_EXPR does not represent
2973 and actual value, so no conversion is needed. */
2974 expr = copy_node (expr);
2975 TREE_TYPE (expr) = type;
2980 /* If we are converting a STRING_CST to another constrained array type,
2981 just make a new one in the proper type. Likewise for a
2983 if (code == ecode && AGGREGATE_TYPE_P (etype)
2984 && ! (TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST
2985 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
2987 expr = copy_node (expr);
2988 TREE_TYPE (expr) = type;
2994 /* If we are converting between two aggregate types of the same
2995 kind, size, mode, and alignment, just make a new COMPONENT_REF.
2996 This avoid unneeded conversions which makes reference computations
2998 if (code == ecode && TYPE_MODE (type) == TYPE_MODE (etype)
2999 && AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype)
3000 && TYPE_ALIGN (type) == TYPE_ALIGN (etype)
3001 && operand_equal_p (TYPE_SIZE (type), TYPE_SIZE (etype), 0))
3002 return build (COMPONENT_REF, type, TREE_OPERAND (expr, 0),
3003 TREE_OPERAND (expr, 1));
3007 case UNCONSTRAINED_ARRAY_REF:
3008 /* Convert this to the type of the inner array by getting the address of
3009 the array from the template. */
3010 expr = build_unary_op (INDIRECT_REF, NULL_TREE,
3011 build_component_ref (TREE_OPERAND (expr, 0),
3012 get_identifier ("P_ARRAY"),
3014 etype = TREE_TYPE (expr);
3015 ecode = TREE_CODE (etype);
3018 case VIEW_CONVERT_EXPR:
3019 if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype)
3020 && ! TYPE_FAT_POINTER_P (type) && ! TYPE_FAT_POINTER_P (etype))
3021 return convert (type, TREE_OPERAND (expr, 0));
3025 /* If both types are record types, just convert the pointer and
3026 make a new INDIRECT_REF.
3028 ??? Disable this for now since it causes problems with the
3029 code in build_binary_op for MODIFY_EXPR which wants to
3030 strip off conversions. But that code really is a mess and
3031 we need to do this a much better way some time. */
3033 && (TREE_CODE (type) == RECORD_TYPE
3034 || TREE_CODE (type) == UNION_TYPE)
3035 && (TREE_CODE (etype) == RECORD_TYPE
3036 || TREE_CODE (etype) == UNION_TYPE)
3037 && ! TYPE_FAT_POINTER_P (type) && ! TYPE_FAT_POINTER_P (etype))
3038 return build_unary_op (INDIRECT_REF, NULL_TREE,
3039 convert (build_pointer_type (type),
3040 TREE_OPERAND (expr, 0)));
3047 /* Check for converting to a pointer to an unconstrained array. */
3048 if (TYPE_FAT_POINTER_P (type) && ! TYPE_FAT_POINTER_P (etype))
3049 return convert_to_fat_pointer (type, expr);
3051 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype)
3052 || (code == INTEGER_CST && ecode == INTEGER_CST
3053 && (type == TREE_TYPE (etype) || etype == TREE_TYPE (type))))
3054 return fold (build1 (NOP_EXPR, type, expr));
3059 return build1 (CONVERT_EXPR, type, expr);
3062 if (TYPE_HAS_ACTUAL_BOUNDS_P (type)
3063 && (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE
3064 || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))))
3065 return unchecked_convert (type, expr, 0);
3066 else if (TYPE_BIASED_REPRESENTATION_P (type))
3067 return fold (build1 (CONVERT_EXPR, type,
3068 fold (build (MINUS_EXPR, TREE_TYPE (type),
3069 convert (TREE_TYPE (type), expr),
3070 TYPE_MIN_VALUE (type)))));
3072 /* ... fall through ... */
3075 return fold (convert_to_integer (type, expr));
3078 case REFERENCE_TYPE:
3079 /* If converting between two pointers to records denoting
3080 both a template and type, adjust if needed to account
3081 for any differing offsets, since one might be negative. */
3082 if (TYPE_THIN_POINTER_P (etype) && TYPE_THIN_POINTER_P (type))
3085 = size_diffop (bit_position (TYPE_FIELDS (TREE_TYPE (etype))),
3086 bit_position (TYPE_FIELDS (TREE_TYPE (type))));
3087 tree byte_diff = size_binop (CEIL_DIV_EXPR, bit_diff,
3088 sbitsize_int (BITS_PER_UNIT));
3090 expr = build1 (NOP_EXPR, type, expr);
3091 TREE_CONSTANT (expr) = TREE_CONSTANT (TREE_OPERAND (expr, 0));
3092 if (integer_zerop (byte_diff))
3095 return build_binary_op (PLUS_EXPR, type, expr,
3096 fold (convert_to_pointer (type, byte_diff)));
3099 /* If converting to a thin pointer, handle specially. */
3100 if (TYPE_THIN_POINTER_P (type)
3101 && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)) != 0)
3102 return convert_to_thin_pointer (type, expr);
3104 /* If converting fat pointer to normal pointer, get the pointer to the
3105 array and then convert it. */
3106 else if (TYPE_FAT_POINTER_P (etype))
3107 expr = build_component_ref (expr, get_identifier ("P_ARRAY"),
3110 return fold (convert_to_pointer (type, expr));
3113 return fold (convert_to_real (type, expr));
3116 if (TYPE_LEFT_JUSTIFIED_MODULAR_P (type) && ! AGGREGATE_TYPE_P (etype))
3118 gnat_build_constructor
3119 (type, tree_cons (TYPE_FIELDS (type),
3120 convert (TREE_TYPE (TYPE_FIELDS (type)), expr),
3123 /* ... fall through ... */
3126 /* In these cases, assume the front-end has validated the conversion.
3127 If the conversion is valid, it will be a bit-wise conversion, so
3128 it can be viewed as an unchecked conversion. */
3129 return unchecked_convert (type, expr, 0);
3132 /* Just validate that the type is indeed that of a field
3133 of the type. Then make the simple conversion. */
3134 for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem))
3136 if (TREE_TYPE (tem) == etype)
3137 return build1 (CONVERT_EXPR, type, expr);
3138 else if (TREE_CODE (TREE_TYPE (tem)) == RECORD_TYPE
3139 && (TYPE_LEFT_JUSTIFIED_MODULAR_P (TREE_TYPE (tem))
3140 || TYPE_IS_PADDING_P (TREE_TYPE (tem)))
3141 && TREE_TYPE (TYPE_FIELDS (TREE_TYPE (tem))) == etype)
3142 return build1 (CONVERT_EXPR, type,
3143 convert (TREE_TYPE (tem), expr));
3148 case UNCONSTRAINED_ARRAY_TYPE:
3149 /* If EXPR is a constrained array, take its address, convert it to a
3150 fat pointer, and then dereference it. Likewise if EXPR is a
3151 record containing both a template and a constrained array.
3152 Note that a record representing a left justified modular type
3153 always represents a packed constrained array. */
3154 if (ecode == ARRAY_TYPE
3155 || (ecode == INTEGER_TYPE && TYPE_HAS_ACTUAL_BOUNDS_P (etype))
3156 || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))
3157 || (ecode == RECORD_TYPE && TYPE_LEFT_JUSTIFIED_MODULAR_P (etype)))
3160 (INDIRECT_REF, NULL_TREE,
3161 convert_to_fat_pointer (TREE_TYPE (type),
3162 build_unary_op (ADDR_EXPR,
3165 /* Do something very similar for converting one unconstrained
3166 array to another. */
3167 else if (ecode == UNCONSTRAINED_ARRAY_TYPE)
3169 build_unary_op (INDIRECT_REF, NULL_TREE,
3170 convert (TREE_TYPE (type),
3171 build_unary_op (ADDR_EXPR,
3177 return fold (convert_to_complex (type, expr));
3184 /* Remove all conversions that are done in EXP. This includes converting
3185 from a padded type or to a left-justified modular type. If TRUE_ADDRESS
3186 is nonzero, always return the address of the containing object even if
3187 the address is not bit-aligned. */
3190 remove_conversions (tree exp, int true_address)
3192 switch (TREE_CODE (exp))
3196 && TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
3197 && TYPE_LEFT_JUSTIFIED_MODULAR_P (TREE_TYPE (exp)))
3198 return remove_conversions (TREE_VALUE (CONSTRUCTOR_ELTS (exp)), 1);
3202 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == RECORD_TYPE
3203 && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
3204 return remove_conversions (TREE_OPERAND (exp, 0), true_address);
3207 case VIEW_CONVERT_EXPR: case NON_LVALUE_EXPR:
3208 case NOP_EXPR: case CONVERT_EXPR: case GNAT_NOP_EXPR:
3209 return remove_conversions (TREE_OPERAND (exp, 0), true_address);
3218 /* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that
3219 refers to the underlying array. If its type has TYPE_CONTAINS_TEMPLATE_P,
3220 likewise return an expression pointing to the underlying array. */
3223 maybe_unconstrained_array (tree exp)
3225 enum tree_code code = TREE_CODE (exp);
3228 switch (TREE_CODE (TREE_TYPE (exp)))
3230 case UNCONSTRAINED_ARRAY_TYPE:
3231 if (code == UNCONSTRAINED_ARRAY_REF)
3234 = build_unary_op (INDIRECT_REF, NULL_TREE,
3235 build_component_ref (TREE_OPERAND (exp, 0),
3236 get_identifier ("P_ARRAY"),
3238 TREE_READONLY (new) = TREE_STATIC (new) = TREE_READONLY (exp);
3242 else if (code == NULL_EXPR)
3243 return build1 (NULL_EXPR,
3244 TREE_TYPE (TREE_TYPE (TYPE_FIELDS
3245 (TREE_TYPE (TREE_TYPE (exp))))),
3246 TREE_OPERAND (exp, 0));
3249 /* If this is a padded type, convert to the unpadded type and see if
3250 it contains a template. */
3251 if (TYPE_IS_PADDING_P (TREE_TYPE (exp)))
3253 new = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (exp))), exp);
3254 if (TREE_CODE (TREE_TYPE (new)) == RECORD_TYPE
3255 && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (new)))
3257 build_component_ref (new, NULL_TREE,
3258 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new))),
3261 else if (TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (exp)))
3263 build_component_ref (exp, NULL_TREE,
3264 TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (exp))), 0);
3274 /* Return an expression that does an unchecked converstion of EXPR to TYPE.
3275 If NOTRUNC_P is set, truncation operations should be suppressed. */
3278 unchecked_convert (tree type, tree expr, int notrunc_p)
3280 tree etype = TREE_TYPE (expr);
3282 /* If the expression is already the right type, we are done. */
3286 /* If both types types are integral just do a normal conversion.
3287 Likewise for a conversion to an unconstrained array. */
3288 if ((((INTEGRAL_TYPE_P (type)
3289 && ! (TREE_CODE (type) == INTEGER_TYPE
3290 && TYPE_VAX_FLOATING_POINT_P (type)))
3291 || (POINTER_TYPE_P (type) && ! TYPE_THIN_POINTER_P (type))
3292 || (TREE_CODE (type) == RECORD_TYPE
3293 && TYPE_LEFT_JUSTIFIED_MODULAR_P (type)))
3294 && ((INTEGRAL_TYPE_P (etype)
3295 && ! (TREE_CODE (etype) == INTEGER_TYPE
3296 && TYPE_VAX_FLOATING_POINT_P (etype)))
3297 || (POINTER_TYPE_P (etype) && ! TYPE_THIN_POINTER_P (etype))
3298 || (TREE_CODE (etype) == RECORD_TYPE
3299 && TYPE_LEFT_JUSTIFIED_MODULAR_P (etype))))
3300 || TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
3304 if (TREE_CODE (etype) == INTEGER_TYPE
3305 && TYPE_BIASED_REPRESENTATION_P (etype))
3307 tree ntype = copy_type (etype);
3309 TYPE_BIASED_REPRESENTATION_P (ntype) = 0;
3310 TYPE_MAIN_VARIANT (ntype) = ntype;
3311 expr = build1 (GNAT_NOP_EXPR, ntype, expr);
3314 if (TREE_CODE (type) == INTEGER_TYPE
3315 && TYPE_BIASED_REPRESENTATION_P (type))
3317 rtype = copy_type (type);
3318 TYPE_BIASED_REPRESENTATION_P (rtype) = 0;
3319 TYPE_MAIN_VARIANT (rtype) = rtype;
3322 expr = convert (rtype, expr);
3324 expr = build1 (GNAT_NOP_EXPR, type, expr);
3327 /* If we are converting TO an integral type whose precision is not the
3328 same as its size, first unchecked convert to a record that contains
3329 an object of the output type. Then extract the field. */
3330 else if (INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type) != 0
3331 && 0 != compare_tree_int (TYPE_RM_SIZE (type),
3332 GET_MODE_BITSIZE (TYPE_MODE (type))))
3334 tree rec_type = make_node (RECORD_TYPE);
3335 tree field = create_field_decl (get_identifier ("OBJ"), type,
3336 rec_type, 1, 0, 0, 0);
3338 TYPE_FIELDS (rec_type) = field;
3339 layout_type (rec_type);
3341 expr = unchecked_convert (rec_type, expr, notrunc_p);
3342 expr = build_component_ref (expr, NULL_TREE, field, 0);
3345 /* Similarly for integral input type whose precision is not equal to its
3347 else if (INTEGRAL_TYPE_P (etype) && TYPE_RM_SIZE (etype) != 0
3348 && 0 != compare_tree_int (TYPE_RM_SIZE (etype),
3349 GET_MODE_BITSIZE (TYPE_MODE (etype))))
3351 tree rec_type = make_node (RECORD_TYPE);
3353 = create_field_decl (get_identifier ("OBJ"), etype, rec_type,
3356 TYPE_FIELDS (rec_type) = field;
3357 layout_type (rec_type);
3359 expr = gnat_build_constructor (rec_type, build_tree_list (field, expr));
3360 expr = unchecked_convert (type, expr, notrunc_p);
3363 /* We have a special case when we are converting between two
3364 unconstrained array types. In that case, take the address,
3365 convert the fat pointer types, and dereference. */
3366 else if (TREE_CODE (etype) == UNCONSTRAINED_ARRAY_TYPE
3367 && TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
3368 expr = build_unary_op (INDIRECT_REF, NULL_TREE,
3369 build1 (VIEW_CONVERT_EXPR, TREE_TYPE (type),
3370 build_unary_op (ADDR_EXPR, NULL_TREE,
3374 expr = maybe_unconstrained_array (expr);
3375 etype = TREE_TYPE (expr);
3376 expr = build1 (VIEW_CONVERT_EXPR, type, expr);
3379 /* If the result is an integral type whose size is not equal to
3380 the size of the underlying machine type, sign- or zero-extend
3381 the result. We need not do this in the case where the input is
3382 an integral type of the same precision and signedness or if the output
3383 is a biased type or if both the input and output are unsigned. */
3385 && INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type) != 0
3386 && ! (TREE_CODE (type) == INTEGER_TYPE
3387 && TYPE_BIASED_REPRESENTATION_P (type))
3388 && 0 != compare_tree_int (TYPE_RM_SIZE (type),
3389 GET_MODE_BITSIZE (TYPE_MODE (type)))
3390 && ! (INTEGRAL_TYPE_P (etype)
3391 && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (etype)
3392 && operand_equal_p (TYPE_RM_SIZE (type),
3393 (TYPE_RM_SIZE (etype) != 0
3394 ? TYPE_RM_SIZE (etype) : TYPE_SIZE (etype)),
3396 && ! (TYPE_UNSIGNED (type) && TYPE_UNSIGNED (etype)))
3398 tree base_type = gnat_type_for_mode (TYPE_MODE (type),
3399 TYPE_UNSIGNED (type));
3401 = convert (base_type,
3402 size_binop (MINUS_EXPR,
3404 (GET_MODE_BITSIZE (TYPE_MODE (type))),
3405 TYPE_RM_SIZE (type)));
3408 build_binary_op (RSHIFT_EXPR, base_type,
3409 build_binary_op (LSHIFT_EXPR, base_type,
3410 convert (base_type, expr),
3415 /* An unchecked conversion should never raise Constraint_Error. The code
3416 below assumes that GCC's conversion routines overflow the same way that
3417 the underlying hardware does. This is probably true. In the rare case
3418 when it is false, we can rely on the fact that such conversions are
3419 erroneous anyway. */
3420 if (TREE_CODE (expr) == INTEGER_CST)
3421 TREE_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (expr) = 0;
3423 /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR,
3424 show no longer constant. */
3425 if (TREE_CODE (expr) == VIEW_CONVERT_EXPR
3426 && ! operand_equal_p (TYPE_SIZE_UNIT (type), TYPE_SIZE_UNIT (etype), 1))
3427 TREE_CONSTANT (expr) = 0;
3432 #include "gt-ada-utils.h"
3433 #include "gtype-ada.h"