1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 88, 92-97, 1998 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file contains the low level primitives for operating on tree nodes,
23 including allocation, list operations, interning of identifiers,
24 construction of data type nodes and statement nodes,
25 and construction of type conversion nodes. It also contains
26 tables index by tree code that describe how to take apart
29 It is intended to be language-independent, but occasionally
30 calls language-dependent routines defined (for C) in typecheck.c.
32 The low-level allocation routines oballoc and permalloc
33 are used also for allocating many other kinds of objects
34 by all passes of the compiler. */
51 #define obstack_chunk_alloc xmalloc
52 #define obstack_chunk_free free
53 /* obstack.[ch] explicitly declined to prototype this. */
54 extern int _obstack_allocated_p PROTO ((struct obstack *h, GENERIC_PTR obj));
56 /* Tree nodes of permanent duration are allocated in this obstack.
57 They are the identifier nodes, and everything outside of
58 the bodies and parameters of function definitions. */
60 struct obstack permanent_obstack;
62 /* The initial RTL, and all ..._TYPE nodes, in a function
63 are allocated in this obstack. Usually they are freed at the
64 end of the function, but if the function is inline they are saved.
65 For top-level functions, this is maybepermanent_obstack.
66 Separate obstacks are made for nested functions. */
68 struct obstack *function_maybepermanent_obstack;
70 /* This is the function_maybepermanent_obstack for top-level functions. */
72 struct obstack maybepermanent_obstack;
74 /* This is a list of function_maybepermanent_obstacks for top-level inline
75 functions that are compiled in the middle of compiling other functions. */
77 struct simple_obstack_stack *toplev_inline_obstacks;
79 /* Former elements of toplev_inline_obstacks that have been recycled. */
81 struct simple_obstack_stack *extra_inline_obstacks;
83 /* This is a list of function_maybepermanent_obstacks for inline functions
84 nested in the current function that were compiled in the middle of
85 compiling other functions. */
87 struct simple_obstack_stack *inline_obstacks;
89 /* The contents of the current function definition are allocated
90 in this obstack, and all are freed at the end of the function.
91 For top-level functions, this is temporary_obstack.
92 Separate obstacks are made for nested functions. */
94 struct obstack *function_obstack;
96 /* This is used for reading initializers of global variables. */
98 struct obstack temporary_obstack;
100 /* The tree nodes of an expression are allocated
101 in this obstack, and all are freed at the end of the expression. */
103 struct obstack momentary_obstack;
105 /* The tree nodes of a declarator are allocated
106 in this obstack, and all are freed when the declarator
109 static struct obstack temp_decl_obstack;
111 /* This points at either permanent_obstack
112 or the current function_maybepermanent_obstack. */
114 struct obstack *saveable_obstack;
116 /* This is same as saveable_obstack during parse and expansion phase;
117 it points to the current function's obstack during optimization.
118 This is the obstack to be used for creating rtl objects. */
120 struct obstack *rtl_obstack;
122 /* This points at either permanent_obstack or the current function_obstack. */
124 struct obstack *current_obstack;
126 /* This points at either permanent_obstack or the current function_obstack
127 or momentary_obstack. */
129 struct obstack *expression_obstack;
131 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
135 struct obstack_stack *next;
136 struct obstack *current;
137 struct obstack *saveable;
138 struct obstack *expression;
142 struct obstack_stack *obstack_stack;
144 /* Obstack for allocating struct obstack_stack entries. */
146 static struct obstack obstack_stack_obstack;
148 /* Addresses of first objects in some obstacks.
149 This is for freeing their entire contents. */
150 char *maybepermanent_firstobj;
151 char *temporary_firstobj;
152 char *momentary_firstobj;
153 char *temp_decl_firstobj;
155 /* This is used to preserve objects (mainly array initializers) that need to
156 live until the end of the current function, but no further. */
157 char *momentary_function_firstobj;
159 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
161 int all_types_permanent;
163 /* Stack of places to restore the momentary obstack back to. */
165 struct momentary_level
167 /* Pointer back to previous such level. */
168 struct momentary_level *prev;
169 /* First object allocated within this level. */
171 /* Value of expression_obstack saved at entry to this level. */
172 struct obstack *obstack;
175 struct momentary_level *momentary_stack;
177 /* Table indexed by tree code giving a string containing a character
178 classifying the tree code. Possibilities are
179 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
181 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
183 char tree_code_type[MAX_TREE_CODES] = {
188 /* Table indexed by tree code giving number of expression
189 operands beyond the fixed part of the node structure.
190 Not used for types or decls. */
192 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
194 int tree_code_length[MAX_TREE_CODES] = {
199 /* Names of tree components.
200 Used for printing out the tree and error messages. */
201 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
203 char *tree_code_name[MAX_TREE_CODES] = {
208 /* Statistics-gathering stuff. */
229 int tree_node_counts[(int)all_kinds];
230 int tree_node_sizes[(int)all_kinds];
231 int id_string_size = 0;
233 char *tree_node_kind_names[] = {
251 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
253 #define MAX_HASH_TABLE 1009
254 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
256 /* 0 while creating built-in identifiers. */
257 static int do_identifier_warnings;
259 /* Unique id for next decl created. */
260 static int next_decl_uid;
261 /* Unique id for next type created. */
262 static int next_type_uid = 1;
264 /* The language-specific function for alias analysis. If NULL, the
265 language does not do any special alias analysis. */
266 int (*lang_get_alias_set) PROTO((tree));
268 /* Here is how primitive or already-canonicalized types' hash
270 #define TYPE_HASH(TYPE) ((unsigned long) (TYPE) & 0777777)
272 extern char *mode_name[];
274 void gcc_obstack_init ();
276 /* Init the principal obstacks. */
281 gcc_obstack_init (&obstack_stack_obstack);
282 gcc_obstack_init (&permanent_obstack);
284 gcc_obstack_init (&temporary_obstack);
285 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
286 gcc_obstack_init (&momentary_obstack);
287 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
288 momentary_function_firstobj = momentary_firstobj;
289 gcc_obstack_init (&maybepermanent_obstack);
290 maybepermanent_firstobj
291 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
292 gcc_obstack_init (&temp_decl_obstack);
293 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
295 function_obstack = &temporary_obstack;
296 function_maybepermanent_obstack = &maybepermanent_obstack;
297 current_obstack = &permanent_obstack;
298 expression_obstack = &permanent_obstack;
299 rtl_obstack = saveable_obstack = &permanent_obstack;
301 /* Init the hash table of identifiers. */
302 bzero ((char *) hash_table, sizeof hash_table);
306 gcc_obstack_init (obstack)
307 struct obstack *obstack;
309 /* Let particular systems override the size of a chunk. */
310 #ifndef OBSTACK_CHUNK_SIZE
311 #define OBSTACK_CHUNK_SIZE 0
313 /* Let them override the alloc and free routines too. */
314 #ifndef OBSTACK_CHUNK_ALLOC
315 #define OBSTACK_CHUNK_ALLOC xmalloc
317 #ifndef OBSTACK_CHUNK_FREE
318 #define OBSTACK_CHUNK_FREE free
320 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
321 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
322 (void (*) ()) OBSTACK_CHUNK_FREE);
325 /* Save all variables describing the current status into the structure *P.
326 This is used before starting a nested function.
328 CONTEXT is the decl_function_context for the function we're about to
329 compile; if it isn't current_function_decl, we have to play some games. */
332 save_tree_status (p, context)
336 p->all_types_permanent = all_types_permanent;
337 p->momentary_stack = momentary_stack;
338 p->maybepermanent_firstobj = maybepermanent_firstobj;
339 p->temporary_firstobj = temporary_firstobj;
340 p->momentary_firstobj = momentary_firstobj;
341 p->momentary_function_firstobj = momentary_function_firstobj;
342 p->function_obstack = function_obstack;
343 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
344 p->current_obstack = current_obstack;
345 p->expression_obstack = expression_obstack;
346 p->saveable_obstack = saveable_obstack;
347 p->rtl_obstack = rtl_obstack;
348 p->inline_obstacks = inline_obstacks;
350 if (context == current_function_decl)
351 /* Objects that need to be saved in this function can be in the nonsaved
352 obstack of the enclosing function since they can't possibly be needed
353 once it has returned. */
354 function_maybepermanent_obstack = function_obstack;
357 /* We're compiling a function which isn't nested in the current
358 function. We need to create a new maybepermanent_obstack for this
359 function, since it can't go onto any of the existing obstacks. */
360 struct simple_obstack_stack **head;
361 struct simple_obstack_stack *current;
363 if (context == NULL_TREE)
364 head = &toplev_inline_obstacks;
367 struct function *f = find_function_data (context);
368 head = &f->inline_obstacks;
371 if (context == NULL_TREE && extra_inline_obstacks)
373 current = extra_inline_obstacks;
374 extra_inline_obstacks = current->next;
378 current = ((struct simple_obstack_stack *)
379 xmalloc (sizeof (struct simple_obstack_stack)));
382 = (struct obstack *) xmalloc (sizeof (struct obstack));
383 gcc_obstack_init (current->obstack);
386 function_maybepermanent_obstack = current->obstack;
388 current->next = *head;
392 maybepermanent_firstobj
393 = (char *) obstack_finish (function_maybepermanent_obstack);
395 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
396 gcc_obstack_init (function_obstack);
398 current_obstack = &permanent_obstack;
399 expression_obstack = &permanent_obstack;
400 rtl_obstack = saveable_obstack = &permanent_obstack;
402 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
403 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
404 momentary_function_firstobj = momentary_firstobj;
407 /* Restore all variables describing the current status from the structure *P.
408 This is used after a nested function. */
411 restore_tree_status (p, context)
415 all_types_permanent = p->all_types_permanent;
416 momentary_stack = p->momentary_stack;
418 obstack_free (&momentary_obstack, momentary_function_firstobj);
420 /* Free saveable storage used by the function just compiled and not
423 CAUTION: This is in function_obstack of the containing function.
424 So we must be sure that we never allocate from that obstack during
425 the compilation of a nested function if we expect it to survive
426 past the nested function's end. */
427 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
429 /* If we were compiling a toplevel function, we can free this space now. */
430 if (context == NULL_TREE)
432 obstack_free (&temporary_obstack, temporary_firstobj);
433 obstack_free (&momentary_obstack, momentary_function_firstobj);
436 /* If we were compiling a toplevel function that we don't actually want
437 to save anything from, return the obstack to the pool. */
438 if (context == NULL_TREE
439 && obstack_empty_p (function_maybepermanent_obstack))
441 struct simple_obstack_stack *current, **p = &toplev_inline_obstacks;
445 while ((*p)->obstack != function_maybepermanent_obstack)
450 current->next = extra_inline_obstacks;
451 extra_inline_obstacks = current;
455 obstack_free (function_obstack, 0);
456 free (function_obstack);
458 temporary_firstobj = p->temporary_firstobj;
459 momentary_firstobj = p->momentary_firstobj;
460 momentary_function_firstobj = p->momentary_function_firstobj;
461 maybepermanent_firstobj = p->maybepermanent_firstobj;
462 function_obstack = p->function_obstack;
463 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
464 current_obstack = p->current_obstack;
465 expression_obstack = p->expression_obstack;
466 saveable_obstack = p->saveable_obstack;
467 rtl_obstack = p->rtl_obstack;
468 inline_obstacks = p->inline_obstacks;
471 /* Start allocating on the temporary (per function) obstack.
472 This is done in start_function before parsing the function body,
473 and before each initialization at top level, and to go back
474 to temporary allocation after doing permanent_allocation. */
477 temporary_allocation ()
479 /* Note that function_obstack at top level points to temporary_obstack.
480 But within a nested function context, it is a separate obstack. */
481 current_obstack = function_obstack;
482 expression_obstack = function_obstack;
483 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
488 /* Start allocating on the permanent obstack but don't
489 free the temporary data. After calling this, call
490 `permanent_allocation' to fully resume permanent allocation status. */
493 end_temporary_allocation ()
495 current_obstack = &permanent_obstack;
496 expression_obstack = &permanent_obstack;
497 rtl_obstack = saveable_obstack = &permanent_obstack;
500 /* Resume allocating on the temporary obstack, undoing
501 effects of `end_temporary_allocation'. */
504 resume_temporary_allocation ()
506 current_obstack = function_obstack;
507 expression_obstack = function_obstack;
508 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
511 /* While doing temporary allocation, switch to allocating in such a
512 way as to save all nodes if the function is inlined. Call
513 resume_temporary_allocation to go back to ordinary temporary
517 saveable_allocation ()
519 /* Note that function_obstack at top level points to temporary_obstack.
520 But within a nested function context, it is a separate obstack. */
521 expression_obstack = current_obstack = saveable_obstack;
524 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
525 recording the previously current obstacks on a stack.
526 This does not free any storage in any obstack. */
529 push_obstacks (current, saveable)
530 struct obstack *current, *saveable;
532 struct obstack_stack *p
533 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
534 (sizeof (struct obstack_stack)));
536 p->current = current_obstack;
537 p->saveable = saveable_obstack;
538 p->expression = expression_obstack;
539 p->rtl = rtl_obstack;
540 p->next = obstack_stack;
543 current_obstack = current;
544 expression_obstack = current;
545 rtl_obstack = saveable_obstack = saveable;
548 /* Save the current set of obstacks, but don't change them. */
551 push_obstacks_nochange ()
553 struct obstack_stack *p
554 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
555 (sizeof (struct obstack_stack)));
557 p->current = current_obstack;
558 p->saveable = saveable_obstack;
559 p->expression = expression_obstack;
560 p->rtl = rtl_obstack;
561 p->next = obstack_stack;
565 /* Pop the obstack selection stack. */
570 struct obstack_stack *p = obstack_stack;
571 obstack_stack = p->next;
573 current_obstack = p->current;
574 saveable_obstack = p->saveable;
575 expression_obstack = p->expression;
576 rtl_obstack = p->rtl;
578 obstack_free (&obstack_stack_obstack, p);
581 /* Nonzero if temporary allocation is currently in effect.
582 Zero if currently doing permanent allocation. */
585 allocation_temporary_p ()
587 return current_obstack != &permanent_obstack;
590 /* Go back to allocating on the permanent obstack
591 and free everything in the temporary obstack.
593 FUNCTION_END is true only if we have just finished compiling a function.
594 In that case, we also free preserved initial values on the momentary
598 permanent_allocation (function_end)
601 /* Free up previous temporary obstack data */
602 obstack_free (&temporary_obstack, temporary_firstobj);
605 obstack_free (&momentary_obstack, momentary_function_firstobj);
606 momentary_firstobj = momentary_function_firstobj;
609 obstack_free (&momentary_obstack, momentary_firstobj);
610 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
611 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
613 /* Free up the maybepermanent_obstacks for any of our nested functions
614 which were compiled at a lower level. */
615 while (inline_obstacks)
617 struct simple_obstack_stack *current = inline_obstacks;
618 inline_obstacks = current->next;
619 obstack_free (current->obstack, 0);
620 free (current->obstack);
624 current_obstack = &permanent_obstack;
625 expression_obstack = &permanent_obstack;
626 rtl_obstack = saveable_obstack = &permanent_obstack;
629 /* Save permanently everything on the maybepermanent_obstack. */
634 maybepermanent_firstobj
635 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
639 preserve_initializer ()
641 struct momentary_level *tem;
645 = (char *) obstack_alloc (&temporary_obstack, 0);
646 maybepermanent_firstobj
647 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
649 old_momentary = momentary_firstobj;
651 = (char *) obstack_alloc (&momentary_obstack, 0);
652 if (momentary_firstobj != old_momentary)
653 for (tem = momentary_stack; tem; tem = tem->prev)
654 tem->base = momentary_firstobj;
657 /* Start allocating new rtl in current_obstack.
658 Use resume_temporary_allocation
659 to go back to allocating rtl in saveable_obstack. */
662 rtl_in_current_obstack ()
664 rtl_obstack = current_obstack;
667 /* Start allocating rtl from saveable_obstack. Intended to be used after
668 a call to push_obstacks_nochange. */
671 rtl_in_saveable_obstack ()
673 rtl_obstack = saveable_obstack;
676 /* Allocate SIZE bytes in the current obstack
677 and return a pointer to them.
678 In practice the current obstack is always the temporary one. */
684 return (char *) obstack_alloc (current_obstack, size);
687 /* Free the object PTR in the current obstack
688 as well as everything allocated since PTR.
689 In practice the current obstack is always the temporary one. */
695 obstack_free (current_obstack, ptr);
698 /* Allocate SIZE bytes in the permanent obstack
699 and return a pointer to them. */
705 return (char *) obstack_alloc (&permanent_obstack, size);
708 /* Allocate NELEM items of SIZE bytes in the permanent obstack
709 and return a pointer to them. The storage is cleared before
710 returning the value. */
713 perm_calloc (nelem, size)
717 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
718 bzero (rval, nelem * size);
722 /* Allocate SIZE bytes in the saveable obstack
723 and return a pointer to them. */
729 return (char *) obstack_alloc (saveable_obstack, size);
732 /* Allocate SIZE bytes in the expression obstack
733 and return a pointer to them. */
739 return (char *) obstack_alloc (expression_obstack, size);
742 /* Print out which obstack an object is in. */
745 print_obstack_name (object, file, prefix)
750 struct obstack *obstack = NULL;
751 char *obstack_name = NULL;
754 for (p = outer_function_chain; p; p = p->next)
756 if (_obstack_allocated_p (p->function_obstack, object))
758 obstack = p->function_obstack;
759 obstack_name = "containing function obstack";
761 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
763 obstack = p->function_maybepermanent_obstack;
764 obstack_name = "containing function maybepermanent obstack";
768 if (_obstack_allocated_p (&obstack_stack_obstack, object))
770 obstack = &obstack_stack_obstack;
771 obstack_name = "obstack_stack_obstack";
773 else if (_obstack_allocated_p (function_obstack, object))
775 obstack = function_obstack;
776 obstack_name = "function obstack";
778 else if (_obstack_allocated_p (&permanent_obstack, object))
780 obstack = &permanent_obstack;
781 obstack_name = "permanent_obstack";
783 else if (_obstack_allocated_p (&momentary_obstack, object))
785 obstack = &momentary_obstack;
786 obstack_name = "momentary_obstack";
788 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
790 obstack = function_maybepermanent_obstack;
791 obstack_name = "function maybepermanent obstack";
793 else if (_obstack_allocated_p (&temp_decl_obstack, object))
795 obstack = &temp_decl_obstack;
796 obstack_name = "temp_decl_obstack";
799 /* Check to see if the object is in the free area of the obstack. */
802 if (object >= obstack->next_free
803 && object < obstack->chunk_limit)
804 fprintf (file, "%s in free portion of obstack %s",
805 prefix, obstack_name);
807 fprintf (file, "%s allocated from %s", prefix, obstack_name);
810 fprintf (file, "%s not allocated from any obstack", prefix);
814 debug_obstack (object)
817 print_obstack_name (object, stderr, "object");
818 fprintf (stderr, ".\n");
821 /* Return 1 if OBJ is in the permanent obstack.
822 This is slow, and should be used only for debugging.
823 Use TREE_PERMANENT for other purposes. */
826 object_permanent_p (obj)
829 return _obstack_allocated_p (&permanent_obstack, obj);
832 /* Start a level of momentary allocation.
833 In C, each compound statement has its own level
834 and that level is freed at the end of each statement.
835 All expression nodes are allocated in the momentary allocation level. */
840 struct momentary_level *tem
841 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
842 sizeof (struct momentary_level));
843 tem->prev = momentary_stack;
844 tem->base = (char *) obstack_base (&momentary_obstack);
845 tem->obstack = expression_obstack;
846 momentary_stack = tem;
847 expression_obstack = &momentary_obstack;
850 /* Set things up so the next clear_momentary will only clear memory
851 past our present position in momentary_obstack. */
854 preserve_momentary ()
856 momentary_stack->base = (char *) obstack_base (&momentary_obstack);
859 /* Free all the storage in the current momentary-allocation level.
860 In C, this happens at the end of each statement. */
865 obstack_free (&momentary_obstack, momentary_stack->base);
868 /* Discard a level of momentary allocation.
869 In C, this happens at the end of each compound statement.
870 Restore the status of expression node allocation
871 that was in effect before this level was created. */
876 struct momentary_level *tem = momentary_stack;
877 momentary_stack = tem->prev;
878 expression_obstack = tem->obstack;
879 /* We can't free TEM from the momentary_obstack, because there might
880 be objects above it which have been saved. We can free back to the
881 stack of the level we are popping off though. */
882 obstack_free (&momentary_obstack, tem->base);
885 /* Pop back to the previous level of momentary allocation,
886 but don't free any momentary data just yet. */
889 pop_momentary_nofree ()
891 struct momentary_level *tem = momentary_stack;
892 momentary_stack = tem->prev;
893 expression_obstack = tem->obstack;
896 /* Call when starting to parse a declaration:
897 make expressions in the declaration last the length of the function.
898 Returns an argument that should be passed to resume_momentary later. */
903 register int tem = expression_obstack == &momentary_obstack;
904 expression_obstack = saveable_obstack;
908 /* Call when finished parsing a declaration:
909 restore the treatment of node-allocation that was
910 in effect before the suspension.
911 YES should be the value previously returned by suspend_momentary. */
914 resume_momentary (yes)
918 expression_obstack = &momentary_obstack;
921 /* Init the tables indexed by tree code.
922 Note that languages can add to these tables to define their own codes. */
930 /* Return a newly allocated node of code CODE.
931 Initialize the node's unique id and its TREE_PERMANENT flag.
932 For decl and type nodes, some other fields are initialized.
933 The rest of the node is initialized to zero.
935 Achoo! I got a code in the node. */
942 register int type = TREE_CODE_CLASS (code);
943 register int length = 0;
944 register struct obstack *obstack = current_obstack;
946 #ifdef GATHER_STATISTICS
947 register tree_node_kind kind;
952 case 'd': /* A decl node */
953 #ifdef GATHER_STATISTICS
956 length = sizeof (struct tree_decl);
957 /* All decls in an inline function need to be saved. */
958 if (obstack != &permanent_obstack)
959 obstack = saveable_obstack;
961 /* PARM_DECLs go on the context of the parent. If this is a nested
962 function, then we must allocate the PARM_DECL on the parent's
963 obstack, so that they will live to the end of the parent's
964 closing brace. This is necessary in case we try to inline the
965 function into its parent.
967 PARM_DECLs of top-level functions do not have this problem. However,
968 we allocate them where we put the FUNCTION_DECL for languages such as
969 Ada that need to consult some flags in the PARM_DECLs of the function
972 See comment in restore_tree_status for why we can't put this
973 in function_obstack. */
974 if (code == PARM_DECL && obstack != &permanent_obstack)
977 if (current_function_decl)
978 context = decl_function_context (current_function_decl);
982 = find_function_data (context)->function_maybepermanent_obstack;
986 case 't': /* a type node */
987 #ifdef GATHER_STATISTICS
990 length = sizeof (struct tree_type);
991 /* All data types are put where we can preserve them if nec. */
992 if (obstack != &permanent_obstack)
993 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
996 case 'b': /* a lexical block */
997 #ifdef GATHER_STATISTICS
1000 length = sizeof (struct tree_block);
1001 /* All BLOCK nodes are put where we can preserve them if nec. */
1002 if (obstack != &permanent_obstack)
1003 obstack = saveable_obstack;
1006 case 's': /* an expression with side effects */
1007 #ifdef GATHER_STATISTICS
1011 case 'r': /* a reference */
1012 #ifdef GATHER_STATISTICS
1016 case 'e': /* an expression */
1017 case '<': /* a comparison expression */
1018 case '1': /* a unary arithmetic expression */
1019 case '2': /* a binary arithmetic expression */
1020 #ifdef GATHER_STATISTICS
1024 obstack = expression_obstack;
1025 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
1026 if (code == BIND_EXPR && obstack != &permanent_obstack)
1027 obstack = saveable_obstack;
1028 length = sizeof (struct tree_exp)
1029 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1032 case 'c': /* a constant */
1033 #ifdef GATHER_STATISTICS
1036 obstack = expression_obstack;
1038 /* We can't use tree_code_length for INTEGER_CST, since the number of
1039 words is machine-dependent due to varying length of HOST_WIDE_INT,
1040 which might be wider than a pointer (e.g., long long). Similarly
1041 for REAL_CST, since the number of words is machine-dependent due
1042 to varying size and alignment of `double'. */
1044 if (code == INTEGER_CST)
1045 length = sizeof (struct tree_int_cst);
1046 else if (code == REAL_CST)
1047 length = sizeof (struct tree_real_cst);
1049 length = sizeof (struct tree_common)
1050 + tree_code_length[(int) code] * sizeof (char *);
1053 case 'x': /* something random, like an identifier. */
1054 #ifdef GATHER_STATISTICS
1055 if (code == IDENTIFIER_NODE)
1057 else if (code == OP_IDENTIFIER)
1059 else if (code == TREE_VEC)
1064 length = sizeof (struct tree_common)
1065 + tree_code_length[(int) code] * sizeof (char *);
1066 /* Identifier nodes are always permanent since they are
1067 unique in a compiler run. */
1068 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1075 t = (tree) obstack_alloc (obstack, length);
1077 #ifdef GATHER_STATISTICS
1078 tree_node_counts[(int)kind]++;
1079 tree_node_sizes[(int)kind] += length;
1082 /* Clear a word at a time. */
1083 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1085 /* Clear any extra bytes. */
1086 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1087 ((char *) t)[i] = 0;
1089 TREE_SET_CODE (t, code);
1090 if (obstack == &permanent_obstack)
1091 TREE_PERMANENT (t) = 1;
1096 TREE_SIDE_EFFECTS (t) = 1;
1097 TREE_TYPE (t) = void_type_node;
1101 if (code != FUNCTION_DECL)
1103 DECL_IN_SYSTEM_HEADER (t)
1104 = in_system_header && (obstack == &permanent_obstack);
1105 DECL_SOURCE_LINE (t) = lineno;
1106 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
1107 DECL_UID (t) = next_decl_uid++;
1111 TYPE_UID (t) = next_type_uid++;
1113 TYPE_MAIN_VARIANT (t) = t;
1114 TYPE_OBSTACK (t) = obstack;
1115 TYPE_ATTRIBUTES (t) = NULL_TREE;
1116 #ifdef SET_DEFAULT_TYPE_ATTRIBUTES
1117 SET_DEFAULT_TYPE_ATTRIBUTES (t);
1119 /* Note that we have not yet computed the alias set for this
1121 TYPE_ALIAS_SET (t) = -1;
1125 TREE_CONSTANT (t) = 1;
1132 /* Return a new node with the same contents as NODE
1133 except that its TREE_CHAIN is zero and it has a fresh uid. */
1140 register enum tree_code code = TREE_CODE (node);
1141 register int length = 0;
1144 switch (TREE_CODE_CLASS (code))
1146 case 'd': /* A decl node */
1147 length = sizeof (struct tree_decl);
1150 case 't': /* a type node */
1151 length = sizeof (struct tree_type);
1154 case 'b': /* a lexical block node */
1155 length = sizeof (struct tree_block);
1158 case 'r': /* a reference */
1159 case 'e': /* an expression */
1160 case 's': /* an expression with side effects */
1161 case '<': /* a comparison expression */
1162 case '1': /* a unary arithmetic expression */
1163 case '2': /* a binary arithmetic expression */
1164 length = sizeof (struct tree_exp)
1165 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1168 case 'c': /* a constant */
1169 /* We can't use tree_code_length for INTEGER_CST, since the number of
1170 words is machine-dependent due to varying length of HOST_WIDE_INT,
1171 which might be wider than a pointer (e.g., long long). Similarly
1172 for REAL_CST, since the number of words is machine-dependent due
1173 to varying size and alignment of `double'. */
1174 if (code == INTEGER_CST)
1175 length = sizeof (struct tree_int_cst);
1176 else if (code == REAL_CST)
1177 length = sizeof (struct tree_real_cst);
1179 length = (sizeof (struct tree_common)
1180 + tree_code_length[(int) code] * sizeof (char *));
1183 case 'x': /* something random, like an identifier. */
1184 length = sizeof (struct tree_common)
1185 + tree_code_length[(int) code] * sizeof (char *);
1186 if (code == TREE_VEC)
1187 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1190 t = (tree) obstack_alloc (current_obstack, length);
1192 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1193 ((int *) t)[i] = ((int *) node)[i];
1194 /* Clear any extra bytes. */
1195 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1196 ((char *) t)[i] = ((char *) node)[i];
1198 /* EXPR_WITH_FILE_LOCATION must keep filename info stored in TREE_CHAIN */
1199 if (TREE_CODE (node) != EXPR_WITH_FILE_LOCATION)
1201 TREE_ASM_WRITTEN (t) = 0;
1203 if (TREE_CODE_CLASS (code) == 'd')
1204 DECL_UID (t) = next_decl_uid++;
1205 else if (TREE_CODE_CLASS (code) == 't')
1207 TYPE_UID (t) = next_type_uid++;
1208 TYPE_OBSTACK (t) = current_obstack;
1210 /* The following is so that the debug code for
1211 the copy is different from the original type.
1212 The two statements usually duplicate each other
1213 (because they clear fields of the same union),
1214 but the optimizer should catch that. */
1215 TYPE_SYMTAB_POINTER (t) = 0;
1216 TYPE_SYMTAB_ADDRESS (t) = 0;
1219 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1224 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1225 For example, this can copy a list made of TREE_LIST nodes. */
1232 register tree prev, next;
1237 head = prev = copy_node (list);
1238 next = TREE_CHAIN (list);
1241 TREE_CHAIN (prev) = copy_node (next);
1242 prev = TREE_CHAIN (prev);
1243 next = TREE_CHAIN (next);
1250 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1251 If an identifier with that name has previously been referred to,
1252 the same node is returned this time. */
1255 get_identifier (text)
1256 register char *text;
1261 register int len, hash_len;
1263 /* Compute length of text in len. */
1264 for (len = 0; text[len]; len++);
1266 /* Decide how much of that length to hash on */
1268 if (warn_id_clash && len > id_clash_len)
1269 hash_len = id_clash_len;
1271 /* Compute hash code */
1272 hi = hash_len * 613 + (unsigned) text[0];
1273 for (i = 1; i < hash_len; i += 2)
1274 hi = ((hi * 613) + (unsigned) (text[i]));
1276 hi &= (1 << HASHBITS) - 1;
1277 hi %= MAX_HASH_TABLE;
1279 /* Search table for identifier */
1280 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1281 if (IDENTIFIER_LENGTH (idp) == len
1282 && IDENTIFIER_POINTER (idp)[0] == text[0]
1283 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1284 return idp; /* <-- return if found */
1286 /* Not found; optionally warn about a similar identifier */
1287 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1288 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1289 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1291 warning ("`%s' and `%s' identical in first %d characters",
1292 IDENTIFIER_POINTER (idp), text, id_clash_len);
1296 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1297 abort (); /* set_identifier_size hasn't been called. */
1299 /* Not found, create one, add to chain */
1300 idp = make_node (IDENTIFIER_NODE);
1301 IDENTIFIER_LENGTH (idp) = len;
1302 #ifdef GATHER_STATISTICS
1303 id_string_size += len;
1306 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1308 TREE_CHAIN (idp) = hash_table[hi];
1309 hash_table[hi] = idp;
1310 return idp; /* <-- return if created */
1313 /* If an identifier with the name TEXT (a null-terminated string) has
1314 previously been referred to, return that node; otherwise return
1318 maybe_get_identifier (text)
1319 register char *text;
1324 register int len, hash_len;
1326 /* Compute length of text in len. */
1327 for (len = 0; text[len]; len++);
1329 /* Decide how much of that length to hash on */
1331 if (warn_id_clash && len > id_clash_len)
1332 hash_len = id_clash_len;
1334 /* Compute hash code */
1335 hi = hash_len * 613 + (unsigned) text[0];
1336 for (i = 1; i < hash_len; i += 2)
1337 hi = ((hi * 613) + (unsigned) (text[i]));
1339 hi &= (1 << HASHBITS) - 1;
1340 hi %= MAX_HASH_TABLE;
1342 /* Search table for identifier */
1343 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1344 if (IDENTIFIER_LENGTH (idp) == len
1345 && IDENTIFIER_POINTER (idp)[0] == text[0]
1346 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1347 return idp; /* <-- return if found */
1352 /* Enable warnings on similar identifiers (if requested).
1353 Done after the built-in identifiers are created. */
1356 start_identifier_warnings ()
1358 do_identifier_warnings = 1;
1361 /* Record the size of an identifier node for the language in use.
1362 SIZE is the total size in bytes.
1363 This is called by the language-specific files. This must be
1364 called before allocating any identifiers. */
1367 set_identifier_size (size)
1370 tree_code_length[(int) IDENTIFIER_NODE]
1371 = (size - sizeof (struct tree_common)) / sizeof (tree);
1374 /* Return a newly constructed INTEGER_CST node whose constant value
1375 is specified by the two ints LOW and HI.
1376 The TREE_TYPE is set to `int'.
1378 This function should be used via the `build_int_2' macro. */
1381 build_int_2_wide (low, hi)
1382 HOST_WIDE_INT low, hi;
1384 register tree t = make_node (INTEGER_CST);
1385 TREE_INT_CST_LOW (t) = low;
1386 TREE_INT_CST_HIGH (t) = hi;
1387 TREE_TYPE (t) = integer_type_node;
1391 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1394 build_real (type, d)
1401 /* Check for valid float value for this type on this target machine;
1402 if not, can print error message and store a valid value in D. */
1403 #ifdef CHECK_FLOAT_VALUE
1404 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1407 v = make_node (REAL_CST);
1408 TREE_TYPE (v) = type;
1409 TREE_REAL_CST (v) = d;
1410 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1414 /* Return a new REAL_CST node whose type is TYPE
1415 and whose value is the integer value of the INTEGER_CST node I. */
1417 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1420 real_value_from_int_cst (type, i)
1425 #ifdef REAL_ARITHMETIC
1426 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1427 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1430 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i),
1431 TREE_INT_CST_HIGH (i), TYPE_MODE (type));
1432 #else /* not REAL_ARITHMETIC */
1433 /* Some 386 compilers mishandle unsigned int to float conversions,
1434 so introduce a temporary variable E to avoid those bugs. */
1435 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1439 d = (double) (~ TREE_INT_CST_HIGH (i));
1440 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1441 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1443 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1451 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1452 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1453 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1455 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1458 #endif /* not REAL_ARITHMETIC */
1462 /* This function can't be implemented if we can't do arithmetic
1463 on the float representation. */
1466 build_real_from_int_cst (type, i)
1471 int overflow = TREE_OVERFLOW (i);
1473 jmp_buf float_error;
1475 v = make_node (REAL_CST);
1476 TREE_TYPE (v) = type;
1478 if (setjmp (float_error))
1485 set_float_handler (float_error);
1487 #ifdef REAL_ARITHMETIC
1488 d = real_value_from_int_cst (type, i);
1490 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type),
1491 real_value_from_int_cst (type, i));
1494 /* Check for valid float value for this type on this target machine. */
1497 set_float_handler (NULL_PTR);
1499 #ifdef CHECK_FLOAT_VALUE
1500 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1503 TREE_REAL_CST (v) = d;
1504 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1508 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1510 /* Return a newly constructed STRING_CST node whose value is
1511 the LEN characters at STR.
1512 The TREE_TYPE is not initialized. */
1515 build_string (len, str)
1519 /* Put the string in saveable_obstack since it will be placed in the RTL
1520 for an "asm" statement and will also be kept around a while if
1521 deferring constant output in varasm.c. */
1523 register tree s = make_node (STRING_CST);
1524 TREE_STRING_LENGTH (s) = len;
1525 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1529 /* Return a newly constructed COMPLEX_CST node whose value is
1530 specified by the real and imaginary parts REAL and IMAG.
1531 Both REAL and IMAG should be constant nodes. TYPE, if specified,
1532 will be the type of the COMPLEX_CST; otherwise a new type will be made. */
1535 build_complex (type, real, imag)
1539 register tree t = make_node (COMPLEX_CST);
1541 TREE_REALPART (t) = real;
1542 TREE_IMAGPART (t) = imag;
1543 TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1544 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1545 TREE_CONSTANT_OVERFLOW (t)
1546 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1550 /* Build a newly constructed TREE_VEC node of length LEN. */
1557 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1558 register struct obstack *obstack = current_obstack;
1561 #ifdef GATHER_STATISTICS
1562 tree_node_counts[(int)vec_kind]++;
1563 tree_node_sizes[(int)vec_kind] += length;
1566 t = (tree) obstack_alloc (obstack, length);
1568 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1571 TREE_SET_CODE (t, TREE_VEC);
1572 TREE_VEC_LENGTH (t) = len;
1573 if (obstack == &permanent_obstack)
1574 TREE_PERMANENT (t) = 1;
1579 /* Return 1 if EXPR is the integer constant zero or a complex constant
1583 integer_zerop (expr)
1588 return ((TREE_CODE (expr) == INTEGER_CST
1589 && ! TREE_CONSTANT_OVERFLOW (expr)
1590 && TREE_INT_CST_LOW (expr) == 0
1591 && TREE_INT_CST_HIGH (expr) == 0)
1592 || (TREE_CODE (expr) == COMPLEX_CST
1593 && integer_zerop (TREE_REALPART (expr))
1594 && integer_zerop (TREE_IMAGPART (expr))));
1597 /* Return 1 if EXPR is the integer constant one or the corresponding
1598 complex constant. */
1606 return ((TREE_CODE (expr) == INTEGER_CST
1607 && ! TREE_CONSTANT_OVERFLOW (expr)
1608 && TREE_INT_CST_LOW (expr) == 1
1609 && TREE_INT_CST_HIGH (expr) == 0)
1610 || (TREE_CODE (expr) == COMPLEX_CST
1611 && integer_onep (TREE_REALPART (expr))
1612 && integer_zerop (TREE_IMAGPART (expr))));
1615 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1616 it contains. Likewise for the corresponding complex constant. */
1619 integer_all_onesp (expr)
1627 if (TREE_CODE (expr) == COMPLEX_CST
1628 && integer_all_onesp (TREE_REALPART (expr))
1629 && integer_zerop (TREE_IMAGPART (expr)))
1632 else if (TREE_CODE (expr) != INTEGER_CST
1633 || TREE_CONSTANT_OVERFLOW (expr))
1636 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1638 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1640 /* Note that using TYPE_PRECISION here is wrong. We care about the
1641 actual bits, not the (arbitrary) range of the type. */
1642 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1643 if (prec >= HOST_BITS_PER_WIDE_INT)
1645 int high_value, shift_amount;
1647 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1649 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1650 /* Can not handle precisions greater than twice the host int size. */
1652 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1653 /* Shifting by the host word size is undefined according to the ANSI
1654 standard, so we must handle this as a special case. */
1657 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1659 return TREE_INT_CST_LOW (expr) == -1
1660 && TREE_INT_CST_HIGH (expr) == high_value;
1663 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1666 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1670 integer_pow2p (expr)
1674 HOST_WIDE_INT high, low;
1678 if (TREE_CODE (expr) == COMPLEX_CST
1679 && integer_pow2p (TREE_REALPART (expr))
1680 && integer_zerop (TREE_IMAGPART (expr)))
1683 if (TREE_CODE (expr) != INTEGER_CST || TREE_CONSTANT_OVERFLOW (expr))
1686 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1687 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1688 high = TREE_INT_CST_HIGH (expr);
1689 low = TREE_INT_CST_LOW (expr);
1691 /* First clear all bits that are beyond the type's precision in case
1692 we've been sign extended. */
1694 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1696 else if (prec > HOST_BITS_PER_WIDE_INT)
1697 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1701 if (prec < HOST_BITS_PER_WIDE_INT)
1702 low &= ~((HOST_WIDE_INT) (-1) << prec);
1705 if (high == 0 && low == 0)
1708 return ((high == 0 && (low & (low - 1)) == 0)
1709 || (low == 0 && (high & (high - 1)) == 0));
1712 /* Return the power of two represented by a tree node known to be a
1720 HOST_WIDE_INT high, low;
1724 if (TREE_CODE (expr) == COMPLEX_CST)
1725 return tree_log2 (TREE_REALPART (expr));
1727 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1728 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1730 high = TREE_INT_CST_HIGH (expr);
1731 low = TREE_INT_CST_LOW (expr);
1733 /* First clear all bits that are beyond the type's precision in case
1734 we've been sign extended. */
1736 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1738 else if (prec > HOST_BITS_PER_WIDE_INT)
1739 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1743 if (prec < HOST_BITS_PER_WIDE_INT)
1744 low &= ~((HOST_WIDE_INT) (-1) << prec);
1747 return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1748 : exact_log2 (low));
1751 /* Return 1 if EXPR is the real constant zero. */
1759 return ((TREE_CODE (expr) == REAL_CST
1760 && ! TREE_CONSTANT_OVERFLOW (expr)
1761 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1762 || (TREE_CODE (expr) == COMPLEX_CST
1763 && real_zerop (TREE_REALPART (expr))
1764 && real_zerop (TREE_IMAGPART (expr))));
1767 /* Return 1 if EXPR is the real constant one in real or complex form. */
1775 return ((TREE_CODE (expr) == REAL_CST
1776 && ! TREE_CONSTANT_OVERFLOW (expr)
1777 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1778 || (TREE_CODE (expr) == COMPLEX_CST
1779 && real_onep (TREE_REALPART (expr))
1780 && real_zerop (TREE_IMAGPART (expr))));
1783 /* Return 1 if EXPR is the real constant two. */
1791 return ((TREE_CODE (expr) == REAL_CST
1792 && ! TREE_CONSTANT_OVERFLOW (expr)
1793 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1794 || (TREE_CODE (expr) == COMPLEX_CST
1795 && real_twop (TREE_REALPART (expr))
1796 && real_zerop (TREE_IMAGPART (expr))));
1799 /* Nonzero if EXP is a constant or a cast of a constant. */
1802 really_constant_p (exp)
1805 /* This is not quite the same as STRIP_NOPS. It does more. */
1806 while (TREE_CODE (exp) == NOP_EXPR
1807 || TREE_CODE (exp) == CONVERT_EXPR
1808 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1809 exp = TREE_OPERAND (exp, 0);
1810 return TREE_CONSTANT (exp);
1813 /* Return first list element whose TREE_VALUE is ELEM.
1814 Return 0 if ELEM is not in LIST. */
1817 value_member (elem, list)
1822 if (elem == TREE_VALUE (list))
1824 list = TREE_CHAIN (list);
1829 /* Return first list element whose TREE_PURPOSE is ELEM.
1830 Return 0 if ELEM is not in LIST. */
1833 purpose_member (elem, list)
1838 if (elem == TREE_PURPOSE (list))
1840 list = TREE_CHAIN (list);
1845 /* Return first list element whose BINFO_TYPE is ELEM.
1846 Return 0 if ELEM is not in LIST. */
1849 binfo_member (elem, list)
1854 if (elem == BINFO_TYPE (list))
1856 list = TREE_CHAIN (list);
1861 /* Return nonzero if ELEM is part of the chain CHAIN. */
1864 chain_member (elem, chain)
1871 chain = TREE_CHAIN (chain);
1877 /* Return nonzero if ELEM is equal to TREE_VALUE (CHAIN) for any piece of
1879 /* ??? This function was added for machine specific attributes but is no
1880 longer used. It could be deleted if we could confirm all front ends
1884 chain_member_value (elem, chain)
1889 if (elem == TREE_VALUE (chain))
1891 chain = TREE_CHAIN (chain);
1897 /* Return nonzero if ELEM is equal to TREE_PURPOSE (CHAIN)
1898 for any piece of chain CHAIN. */
1899 /* ??? This function was added for machine specific attributes but is no
1900 longer used. It could be deleted if we could confirm all front ends
1904 chain_member_purpose (elem, chain)
1909 if (elem == TREE_PURPOSE (chain))
1911 chain = TREE_CHAIN (chain);
1917 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1918 We expect a null pointer to mark the end of the chain.
1919 This is the Lisp primitive `length'. */
1926 register int len = 0;
1928 for (tail = t; tail; tail = TREE_CHAIN (tail))
1934 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1935 by modifying the last node in chain 1 to point to chain 2.
1936 This is the Lisp primitive `nconc'. */
1948 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1950 TREE_CHAIN (t1) = op2;
1951 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1953 abort (); /* Circularity created. */
1959 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1963 register tree chain;
1967 while ((next = TREE_CHAIN (chain)))
1972 /* Reverse the order of elements in the chain T,
1973 and return the new head of the chain (old last element). */
1979 register tree prev = 0, decl, next;
1980 for (decl = t; decl; decl = next)
1982 next = TREE_CHAIN (decl);
1983 TREE_CHAIN (decl) = prev;
1989 /* Given a chain CHAIN of tree nodes,
1990 construct and return a list of those nodes. */
1996 tree result = NULL_TREE;
1997 tree in_tail = chain;
1998 tree out_tail = NULL_TREE;
2002 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
2004 TREE_CHAIN (out_tail) = next;
2008 in_tail = TREE_CHAIN (in_tail);
2014 /* Return a newly created TREE_LIST node whose
2015 purpose and value fields are PARM and VALUE. */
2018 build_tree_list (parm, value)
2021 register tree t = make_node (TREE_LIST);
2022 TREE_PURPOSE (t) = parm;
2023 TREE_VALUE (t) = value;
2027 /* Similar, but build on the temp_decl_obstack. */
2030 build_decl_list (parm, value)
2034 register struct obstack *ambient_obstack = current_obstack;
2035 current_obstack = &temp_decl_obstack;
2036 node = build_tree_list (parm, value);
2037 current_obstack = ambient_obstack;
2041 /* Similar, but build on the expression_obstack. */
2044 build_expr_list (parm, value)
2048 register struct obstack *ambient_obstack = current_obstack;
2049 current_obstack = expression_obstack;
2050 node = build_tree_list (parm, value);
2051 current_obstack = ambient_obstack;
2055 /* Return a newly created TREE_LIST node whose
2056 purpose and value fields are PARM and VALUE
2057 and whose TREE_CHAIN is CHAIN. */
2060 tree_cons (purpose, value, chain)
2061 tree purpose, value, chain;
2064 register tree node = make_node (TREE_LIST);
2067 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
2068 #ifdef GATHER_STATISTICS
2069 tree_node_counts[(int)x_kind]++;
2070 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
2073 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
2074 ((int *) node)[i] = 0;
2076 TREE_SET_CODE (node, TREE_LIST);
2077 if (current_obstack == &permanent_obstack)
2078 TREE_PERMANENT (node) = 1;
2081 TREE_CHAIN (node) = chain;
2082 TREE_PURPOSE (node) = purpose;
2083 TREE_VALUE (node) = value;
2087 /* Similar, but build on the temp_decl_obstack. */
2090 decl_tree_cons (purpose, value, chain)
2091 tree purpose, value, chain;
2094 register struct obstack *ambient_obstack = current_obstack;
2095 current_obstack = &temp_decl_obstack;
2096 node = tree_cons (purpose, value, chain);
2097 current_obstack = ambient_obstack;
2101 /* Similar, but build on the expression_obstack. */
2104 expr_tree_cons (purpose, value, chain)
2105 tree purpose, value, chain;
2108 register struct obstack *ambient_obstack = current_obstack;
2109 current_obstack = expression_obstack;
2110 node = tree_cons (purpose, value, chain);
2111 current_obstack = ambient_obstack;
2115 /* Same as `tree_cons' but make a permanent object. */
2118 perm_tree_cons (purpose, value, chain)
2119 tree purpose, value, chain;
2122 register struct obstack *ambient_obstack = current_obstack;
2123 current_obstack = &permanent_obstack;
2125 node = tree_cons (purpose, value, chain);
2126 current_obstack = ambient_obstack;
2130 /* Same as `tree_cons', but make this node temporary, regardless. */
2133 temp_tree_cons (purpose, value, chain)
2134 tree purpose, value, chain;
2137 register struct obstack *ambient_obstack = current_obstack;
2138 current_obstack = &temporary_obstack;
2140 node = tree_cons (purpose, value, chain);
2141 current_obstack = ambient_obstack;
2145 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
2148 saveable_tree_cons (purpose, value, chain)
2149 tree purpose, value, chain;
2152 register struct obstack *ambient_obstack = current_obstack;
2153 current_obstack = saveable_obstack;
2155 node = tree_cons (purpose, value, chain);
2156 current_obstack = ambient_obstack;
2160 /* Return the size nominally occupied by an object of type TYPE
2161 when it resides in memory. The value is measured in units of bytes,
2162 and its data type is that normally used for type sizes
2163 (which is the first type created by make_signed_type or
2164 make_unsigned_type). */
2167 size_in_bytes (type)
2172 if (type == error_mark_node)
2173 return integer_zero_node;
2175 type = TYPE_MAIN_VARIANT (type);
2176 t = TYPE_SIZE_UNIT (type);
2179 incomplete_type_error (NULL_TREE, type);
2180 return integer_zero_node;
2182 if (TREE_CODE (t) == INTEGER_CST)
2183 force_fit_type (t, 0);
2188 /* Return the size of TYPE (in bytes) as a wide integer
2189 or return -1 if the size can vary or is larger than an integer. */
2192 int_size_in_bytes (type)
2197 if (type == error_mark_node)
2200 type = TYPE_MAIN_VARIANT (type);
2201 t = TYPE_SIZE_UNIT (type);
2203 || TREE_CODE (t) != INTEGER_CST
2204 || TREE_INT_CST_HIGH (t) != 0)
2207 return TREE_INT_CST_LOW (t);
2210 /* Return, as a tree node, the number of elements for TYPE (which is an
2211 ARRAY_TYPE) minus one. This counts only elements of the top array.
2213 Don't let any SAVE_EXPRs escape; if we are called as part of a cleanup
2214 action, they would get unsaved. */
2217 array_type_nelts (type)
2220 tree index_type, min, max;
2222 /* If they did it with unspecified bounds, then we should have already
2223 given an error about it before we got here. */
2224 if (! TYPE_DOMAIN (type))
2225 return error_mark_node;
2227 index_type = TYPE_DOMAIN (type);
2228 min = TYPE_MIN_VALUE (index_type);
2229 max = TYPE_MAX_VALUE (index_type);
2231 if (! TREE_CONSTANT (min))
2234 if (TREE_CODE (min) == SAVE_EXPR)
2235 min = build (RTL_EXPR, TREE_TYPE (TYPE_MIN_VALUE (index_type)), 0,
2236 SAVE_EXPR_RTL (min));
2238 min = TYPE_MIN_VALUE (index_type);
2241 if (! TREE_CONSTANT (max))
2244 if (TREE_CODE (max) == SAVE_EXPR)
2245 max = build (RTL_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)), 0,
2246 SAVE_EXPR_RTL (max));
2248 max = TYPE_MAX_VALUE (index_type);
2251 return (integer_zerop (min)
2253 : fold (build (MINUS_EXPR, TREE_TYPE (max), max, min)));
2256 /* Return nonzero if arg is static -- a reference to an object in
2257 static storage. This is not the same as the C meaning of `static'. */
2263 switch (TREE_CODE (arg))
2266 /* Nested functions aren't static, since taking their address
2267 involves a trampoline. */
2268 return (decl_function_context (arg) == 0 || DECL_NO_STATIC_CHAIN (arg))
2269 && ! DECL_NON_ADDR_CONST_P (arg);
2272 return (TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2273 && ! DECL_NON_ADDR_CONST_P (arg);
2276 return TREE_STATIC (arg);
2281 /* If we are referencing a bitfield, we can't evaluate an
2282 ADDR_EXPR at compile time and so it isn't a constant. */
2284 return (! DECL_BIT_FIELD (TREE_OPERAND (arg, 1))
2285 && staticp (TREE_OPERAND (arg, 0)));
2291 /* This case is technically correct, but results in setting
2292 TREE_CONSTANT on ADDR_EXPRs that cannot be evaluated at
2295 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
2299 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2300 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2301 return staticp (TREE_OPERAND (arg, 0));
2308 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2309 Do this to any expression which may be used in more than one place,
2310 but must be evaluated only once.
2312 Normally, expand_expr would reevaluate the expression each time.
2313 Calling save_expr produces something that is evaluated and recorded
2314 the first time expand_expr is called on it. Subsequent calls to
2315 expand_expr just reuse the recorded value.
2317 The call to expand_expr that generates code that actually computes
2318 the value is the first call *at compile time*. Subsequent calls
2319 *at compile time* generate code to use the saved value.
2320 This produces correct result provided that *at run time* control
2321 always flows through the insns made by the first expand_expr
2322 before reaching the other places where the save_expr was evaluated.
2323 You, the caller of save_expr, must make sure this is so.
2325 Constants, and certain read-only nodes, are returned with no
2326 SAVE_EXPR because that is safe. Expressions containing placeholders
2327 are not touched; see tree.def for an explanation of what these
2334 register tree t = fold (expr);
2336 /* We don't care about whether this can be used as an lvalue in this
2338 while (TREE_CODE (t) == NON_LVALUE_EXPR)
2339 t = TREE_OPERAND (t, 0);
2341 /* If the tree evaluates to a constant, then we don't want to hide that
2342 fact (i.e. this allows further folding, and direct checks for constants).
2343 However, a read-only object that has side effects cannot be bypassed.
2344 Since it is no problem to reevaluate literals, we just return the
2347 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
2348 || TREE_CODE (t) == SAVE_EXPR || TREE_CODE (t) == ERROR_MARK)
2351 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2352 it means that the size or offset of some field of an object depends on
2353 the value within another field.
2355 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2356 and some variable since it would then need to be both evaluated once and
2357 evaluated more than once. Front-ends must assure this case cannot
2358 happen by surrounding any such subexpressions in their own SAVE_EXPR
2359 and forcing evaluation at the proper time. */
2360 if (contains_placeholder_p (t))
2363 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
2365 /* This expression might be placed ahead of a jump to ensure that the
2366 value was computed on both sides of the jump. So make sure it isn't
2367 eliminated as dead. */
2368 TREE_SIDE_EFFECTS (t) = 1;
2372 /* Arrange for an expression to be expanded multiple independent
2373 times. This is useful for cleanup actions, as the backend can
2374 expand them multiple times in different places. */
2382 /* If this is already protected, no sense in protecting it again. */
2383 if (TREE_CODE (expr) == UNSAVE_EXPR)
2386 t = build1 (UNSAVE_EXPR, TREE_TYPE (expr), expr);
2387 TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
2391 /* Returns the index of the first non-tree operand for CODE, or the number
2392 of operands if all are trees. */
2396 enum tree_code code;
2406 case WITH_CLEANUP_EXPR:
2407 /* Should be defined to be 2. */
2409 case METHOD_CALL_EXPR:
2412 return tree_code_length [(int) code];
2416 /* Modify a tree in place so that all the evaluate only once things
2417 are cleared out. Return the EXPR given. */
2420 unsave_expr_now (expr)
2423 enum tree_code code;
2427 if (expr == NULL_TREE)
2430 code = TREE_CODE (expr);
2431 first_rtl = first_rtl_op (code);
2435 SAVE_EXPR_RTL (expr) = 0;
2439 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 3);
2440 TREE_OPERAND (expr, 3) = NULL_TREE;
2444 /* I don't yet know how to emit a sequence multiple times. */
2445 if (RTL_EXPR_SEQUENCE (expr) != 0)
2450 CALL_EXPR_RTL (expr) = 0;
2451 if (TREE_OPERAND (expr, 1)
2452 && TREE_CODE (TREE_OPERAND (expr, 1)) == TREE_LIST)
2454 tree exp = TREE_OPERAND (expr, 1);
2457 unsave_expr_now (TREE_VALUE (exp));
2458 exp = TREE_CHAIN (exp);
2467 switch (TREE_CODE_CLASS (code))
2469 case 'c': /* a constant */
2470 case 't': /* a type node */
2471 case 'x': /* something random, like an identifier or an ERROR_MARK. */
2472 case 'd': /* A decl node */
2473 case 'b': /* A block node */
2476 case 'e': /* an expression */
2477 case 'r': /* a reference */
2478 case 's': /* an expression with side effects */
2479 case '<': /* a comparison expression */
2480 case '2': /* a binary arithmetic expression */
2481 case '1': /* a unary arithmetic expression */
2482 for (i = first_rtl - 1; i >= 0; i--)
2483 unsave_expr_now (TREE_OPERAND (expr, i));
2491 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2492 or offset that depends on a field within a record. */
2495 contains_placeholder_p (exp)
2498 register enum tree_code code = TREE_CODE (exp);
2501 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2502 in it since it is supplying a value for it. */
2503 if (code == WITH_RECORD_EXPR)
2505 else if (code == PLACEHOLDER_EXPR)
2508 switch (TREE_CODE_CLASS (code))
2511 /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2512 position computations since they will be converted into a
2513 WITH_RECORD_EXPR involving the reference, which will assume
2514 here will be valid. */
2515 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2518 if (code == TREE_LIST)
2519 return (contains_placeholder_p (TREE_VALUE (exp))
2520 || (TREE_CHAIN (exp) != 0
2521 && contains_placeholder_p (TREE_CHAIN (exp))));
2530 /* Ignoring the first operand isn't quite right, but works best. */
2531 return contains_placeholder_p (TREE_OPERAND (exp, 1));
2538 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2539 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2540 || contains_placeholder_p (TREE_OPERAND (exp, 2)));
2543 /* If we already know this doesn't have a placeholder, don't
2545 if (SAVE_EXPR_NOPLACEHOLDER (exp) || SAVE_EXPR_RTL (exp) != 0)
2548 SAVE_EXPR_NOPLACEHOLDER (exp) = 1;
2549 result = contains_placeholder_p (TREE_OPERAND (exp, 0));
2551 SAVE_EXPR_NOPLACEHOLDER (exp) = 0;
2556 return (TREE_OPERAND (exp, 1) != 0
2557 && contains_placeholder_p (TREE_OPERAND (exp, 1)));
2563 switch (tree_code_length[(int) code])
2566 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2568 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2569 || contains_placeholder_p (TREE_OPERAND (exp, 1)));
2580 /* Return 1 if EXP contains any expressions that produce cleanups for an
2581 outer scope to deal with. Used by fold. */
2589 if (! TREE_SIDE_EFFECTS (exp))
2592 switch (TREE_CODE (exp))
2595 case WITH_CLEANUP_EXPR:
2598 case CLEANUP_POINT_EXPR:
2602 for (exp = TREE_OPERAND (exp, 1); exp; exp = TREE_CHAIN (exp))
2604 cmp = has_cleanups (TREE_VALUE (exp));
2614 /* This general rule works for most tree codes. All exceptions should be
2615 handled above. If this is a language-specific tree code, we can't
2616 trust what might be in the operand, so say we don't know
2618 if ((int) TREE_CODE (exp) >= (int) LAST_AND_UNUSED_TREE_CODE)
2621 nops = first_rtl_op (TREE_CODE (exp));
2622 for (i = 0; i < nops; i++)
2623 if (TREE_OPERAND (exp, i) != 0)
2625 int type = TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, i)));
2626 if (type == 'e' || type == '<' || type == '1' || type == '2'
2627 || type == 'r' || type == 's')
2629 cmp = has_cleanups (TREE_OPERAND (exp, i));
2638 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2639 return a tree with all occurrences of references to F in a
2640 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2641 contains only arithmetic expressions or a CALL_EXPR with a
2642 PLACEHOLDER_EXPR occurring only in its arglist. */
2645 substitute_in_expr (exp, f, r)
2650 enum tree_code code = TREE_CODE (exp);
2655 switch (TREE_CODE_CLASS (code))
2662 if (code == PLACEHOLDER_EXPR)
2664 else if (code == TREE_LIST)
2666 op0 = (TREE_CHAIN (exp) == 0
2667 ? 0 : substitute_in_expr (TREE_CHAIN (exp), f, r));
2668 op1 = substitute_in_expr (TREE_VALUE (exp), f, r);
2669 if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2672 return tree_cons (TREE_PURPOSE (exp), op1, op0);
2681 switch (tree_code_length[(int) code])
2684 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2685 if (op0 == TREE_OPERAND (exp, 0))
2688 new = fold (build1 (code, TREE_TYPE (exp), op0));
2692 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2693 could, but we don't support it. */
2694 if (code == RTL_EXPR)
2696 else if (code == CONSTRUCTOR)
2699 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2700 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2701 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2704 new = fold (build (code, TREE_TYPE (exp), op0, op1));
2708 /* It cannot be that anything inside a SAVE_EXPR contains a
2709 PLACEHOLDER_EXPR. */
2710 if (code == SAVE_EXPR)
2713 else if (code == CALL_EXPR)
2715 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2716 if (op1 == TREE_OPERAND (exp, 1))
2719 return build (code, TREE_TYPE (exp),
2720 TREE_OPERAND (exp, 0), op1, NULL_TREE);
2723 else if (code != COND_EXPR)
2726 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2727 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2728 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2729 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2730 && op2 == TREE_OPERAND (exp, 2))
2733 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2746 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2747 and it is the right field, replace it with R. */
2748 for (inner = TREE_OPERAND (exp, 0);
2749 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2750 inner = TREE_OPERAND (inner, 0))
2752 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2753 && TREE_OPERAND (exp, 1) == f)
2756 /* If this expression hasn't been completed let, leave it
2758 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2759 && TREE_TYPE (inner) == 0)
2762 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2763 if (op0 == TREE_OPERAND (exp, 0))
2766 new = fold (build (code, TREE_TYPE (exp), op0,
2767 TREE_OPERAND (exp, 1)));
2771 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2772 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2773 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2774 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2775 && op2 == TREE_OPERAND (exp, 2))
2778 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2783 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2784 if (op0 == TREE_OPERAND (exp, 0))
2787 new = fold (build1 (code, TREE_TYPE (exp), op0));
2799 TREE_READONLY (new) = TREE_READONLY (exp);
2803 /* Stabilize a reference so that we can use it any number of times
2804 without causing its operands to be evaluated more than once.
2805 Returns the stabilized reference. This works by means of save_expr,
2806 so see the caveats in the comments about save_expr.
2808 Also allows conversion expressions whose operands are references.
2809 Any other kind of expression is returned unchanged. */
2812 stabilize_reference (ref)
2815 register tree result;
2816 register enum tree_code code = TREE_CODE (ref);
2823 /* No action is needed in this case. */
2829 case FIX_TRUNC_EXPR:
2830 case FIX_FLOOR_EXPR:
2831 case FIX_ROUND_EXPR:
2833 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2837 result = build_nt (INDIRECT_REF,
2838 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2842 result = build_nt (COMPONENT_REF,
2843 stabilize_reference (TREE_OPERAND (ref, 0)),
2844 TREE_OPERAND (ref, 1));
2848 result = build_nt (BIT_FIELD_REF,
2849 stabilize_reference (TREE_OPERAND (ref, 0)),
2850 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2851 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2855 result = build_nt (ARRAY_REF,
2856 stabilize_reference (TREE_OPERAND (ref, 0)),
2857 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2861 /* We cannot wrap the first expression in a SAVE_EXPR, as then
2862 it wouldn't be ignored. This matters when dealing with
2864 return stabilize_reference_1 (ref);
2867 result = build1 (INDIRECT_REF, TREE_TYPE (ref),
2868 save_expr (build1 (ADDR_EXPR,
2869 build_pointer_type (TREE_TYPE (ref)),
2874 /* If arg isn't a kind of lvalue we recognize, make no change.
2875 Caller should recognize the error for an invalid lvalue. */
2880 return error_mark_node;
2883 TREE_TYPE (result) = TREE_TYPE (ref);
2884 TREE_READONLY (result) = TREE_READONLY (ref);
2885 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2886 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2887 TREE_RAISES (result) = TREE_RAISES (ref);
2892 /* Subroutine of stabilize_reference; this is called for subtrees of
2893 references. Any expression with side-effects must be put in a SAVE_EXPR
2894 to ensure that it is only evaluated once.
2896 We don't put SAVE_EXPR nodes around everything, because assigning very
2897 simple expressions to temporaries causes us to miss good opportunities
2898 for optimizations. Among other things, the opportunity to fold in the
2899 addition of a constant into an addressing mode often gets lost, e.g.
2900 "y[i+1] += x;". In general, we take the approach that we should not make
2901 an assignment unless we are forced into it - i.e., that any non-side effect
2902 operator should be allowed, and that cse should take care of coalescing
2903 multiple utterances of the same expression should that prove fruitful. */
2906 stabilize_reference_1 (e)
2909 register tree result;
2910 register enum tree_code code = TREE_CODE (e);
2912 /* We cannot ignore const expressions because it might be a reference
2913 to a const array but whose index contains side-effects. But we can
2914 ignore things that are actual constant or that already have been
2915 handled by this function. */
2917 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2920 switch (TREE_CODE_CLASS (code))
2930 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2931 so that it will only be evaluated once. */
2932 /* The reference (r) and comparison (<) classes could be handled as
2933 below, but it is generally faster to only evaluate them once. */
2934 if (TREE_SIDE_EFFECTS (e))
2935 return save_expr (e);
2939 /* Constants need no processing. In fact, we should never reach
2944 /* Division is slow and tends to be compiled with jumps,
2945 especially the division by powers of 2 that is often
2946 found inside of an array reference. So do it just once. */
2947 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2948 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2949 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2950 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2951 return save_expr (e);
2952 /* Recursively stabilize each operand. */
2953 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2954 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2958 /* Recursively stabilize each operand. */
2959 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2966 TREE_TYPE (result) = TREE_TYPE (e);
2967 TREE_READONLY (result) = TREE_READONLY (e);
2968 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2969 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2970 TREE_RAISES (result) = TREE_RAISES (e);
2975 /* Low-level constructors for expressions. */
2977 /* Build an expression of code CODE, data type TYPE,
2978 and operands as specified by the arguments ARG1 and following arguments.
2979 Expressions and reference nodes can be created this way.
2980 Constants, decls, types and misc nodes cannot be. */
2983 build VPROTO((enum tree_code code, tree tt, ...))
2986 enum tree_code code;
2991 register int length;
2997 code = va_arg (p, enum tree_code);
2998 tt = va_arg (p, tree);
3001 t = make_node (code);
3002 length = tree_code_length[(int) code];
3007 /* This is equivalent to the loop below, but faster. */
3008 register tree arg0 = va_arg (p, tree);
3009 register tree arg1 = va_arg (p, tree);
3010 TREE_OPERAND (t, 0) = arg0;
3011 TREE_OPERAND (t, 1) = arg1;
3012 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
3013 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
3014 TREE_SIDE_EFFECTS (t) = 1;
3016 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
3018 else if (length == 1)
3020 register tree arg0 = va_arg (p, tree);
3022 /* Call build1 for this! */
3023 if (TREE_CODE_CLASS (code) != 's')
3025 TREE_OPERAND (t, 0) = arg0;
3026 if (arg0 && TREE_SIDE_EFFECTS (arg0))
3027 TREE_SIDE_EFFECTS (t) = 1;
3028 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
3032 for (i = 0; i < length; i++)
3034 register tree operand = va_arg (p, tree);
3035 TREE_OPERAND (t, i) = operand;
3038 if (TREE_SIDE_EFFECTS (operand))
3039 TREE_SIDE_EFFECTS (t) = 1;
3040 if (TREE_RAISES (operand))
3041 TREE_RAISES (t) = 1;
3049 /* Same as above, but only builds for unary operators.
3050 Saves lions share of calls to `build'; cuts down use
3051 of varargs, which is expensive for RISC machines. */
3054 build1 (code, type, node)
3055 enum tree_code code;
3059 register struct obstack *obstack = expression_obstack;
3060 register int i, length;
3061 #ifdef GATHER_STATISTICS
3062 register tree_node_kind kind;
3066 #ifdef GATHER_STATISTICS
3067 if (TREE_CODE_CLASS (code) == 'r')
3073 length = sizeof (struct tree_exp);
3075 t = (tree) obstack_alloc (obstack, length);
3077 #ifdef GATHER_STATISTICS
3078 tree_node_counts[(int)kind]++;
3079 tree_node_sizes[(int)kind] += length;
3082 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
3085 TREE_TYPE (t) = type;
3086 TREE_SET_CODE (t, code);
3088 if (obstack == &permanent_obstack)
3089 TREE_PERMANENT (t) = 1;
3091 TREE_OPERAND (t, 0) = node;
3094 if (TREE_SIDE_EFFECTS (node))
3095 TREE_SIDE_EFFECTS (t) = 1;
3096 if (TREE_RAISES (node))
3097 TREE_RAISES (t) = 1;
3103 /* Similar except don't specify the TREE_TYPE
3104 and leave the TREE_SIDE_EFFECTS as 0.
3105 It is permissible for arguments to be null,
3106 or even garbage if their values do not matter. */
3109 build_nt VPROTO((enum tree_code code, ...))
3112 enum tree_code code;
3116 register int length;
3122 code = va_arg (p, enum tree_code);
3125 t = make_node (code);
3126 length = tree_code_length[(int) code];
3128 for (i = 0; i < length; i++)
3129 TREE_OPERAND (t, i) = va_arg (p, tree);
3135 /* Similar to `build_nt', except we build
3136 on the temp_decl_obstack, regardless. */
3139 build_parse_node VPROTO((enum tree_code code, ...))
3142 enum tree_code code;
3144 register struct obstack *ambient_obstack = expression_obstack;
3147 register int length;
3153 code = va_arg (p, enum tree_code);
3156 expression_obstack = &temp_decl_obstack;
3158 t = make_node (code);
3159 length = tree_code_length[(int) code];
3161 for (i = 0; i < length; i++)
3162 TREE_OPERAND (t, i) = va_arg (p, tree);
3165 expression_obstack = ambient_obstack;
3170 /* Commented out because this wants to be done very
3171 differently. See cp-lex.c. */
3173 build_op_identifier (op1, op2)
3176 register tree t = make_node (OP_IDENTIFIER);
3177 TREE_PURPOSE (t) = op1;
3178 TREE_VALUE (t) = op2;
3183 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3184 We do NOT enter this node in any sort of symbol table.
3186 layout_decl is used to set up the decl's storage layout.
3187 Other slots are initialized to 0 or null pointers. */
3190 build_decl (code, name, type)
3191 enum tree_code code;
3196 t = make_node (code);
3198 /* if (type == error_mark_node)
3199 type = integer_type_node; */
3200 /* That is not done, deliberately, so that having error_mark_node
3201 as the type can suppress useless errors in the use of this variable. */
3203 DECL_NAME (t) = name;
3204 DECL_ASSEMBLER_NAME (t) = name;
3205 TREE_TYPE (t) = type;
3207 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3209 else if (code == FUNCTION_DECL)
3210 DECL_MODE (t) = FUNCTION_MODE;
3215 /* BLOCK nodes are used to represent the structure of binding contours
3216 and declarations, once those contours have been exited and their contents
3217 compiled. This information is used for outputting debugging info. */
3220 build_block (vars, tags, subblocks, supercontext, chain)
3221 tree vars, tags, subblocks, supercontext, chain;
3223 register tree block = make_node (BLOCK);
3224 BLOCK_VARS (block) = vars;
3225 BLOCK_TYPE_TAGS (block) = tags;
3226 BLOCK_SUBBLOCKS (block) = subblocks;
3227 BLOCK_SUPERCONTEXT (block) = supercontext;
3228 BLOCK_CHAIN (block) = chain;
3232 /* EXPR_WITH_FILE_LOCATION are used to keep track of the exact
3233 location where an expression or an identifier were encountered. It
3234 is necessary for languages where the frontend parser will handle
3235 recursively more than one file (Java is one of them). */
3238 build_expr_wfl (node, file, line, col)
3243 static char *last_file = 0;
3244 static tree last_filenode = NULL_TREE;
3245 register tree wfl = make_node (EXPR_WITH_FILE_LOCATION);
3247 EXPR_WFL_NODE (wfl) = node;
3248 EXPR_WFL_SET_LINECOL (wfl, line, col);
3249 if (file != last_file)
3252 last_filenode = file ? get_identifier (file) : NULL_TREE;
3254 EXPR_WFL_FILENAME_NODE (wfl) = last_filenode;
3257 TREE_SIDE_EFFECTS (wfl) = TREE_SIDE_EFFECTS (node);
3258 TREE_TYPE (wfl) = TREE_TYPE (node);
3263 /* Return a declaration like DDECL except that its DECL_MACHINE_ATTRIBUTE
3267 build_decl_attribute_variant (ddecl, attribute)
3268 tree ddecl, attribute;
3270 DECL_MACHINE_ATTRIBUTES (ddecl) = attribute;
3274 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3277 Record such modified types already made so we don't make duplicates. */
3280 build_type_attribute_variant (ttype, attribute)
3281 tree ttype, attribute;
3283 if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3285 register int hashcode;
3286 register struct obstack *ambient_obstack = current_obstack;
3289 if (ambient_obstack != &permanent_obstack)
3290 current_obstack = TYPE_OBSTACK (ttype);
3292 ntype = copy_node (ttype);
3293 current_obstack = ambient_obstack;
3295 TYPE_POINTER_TO (ntype) = 0;
3296 TYPE_REFERENCE_TO (ntype) = 0;
3297 TYPE_ATTRIBUTES (ntype) = attribute;
3299 /* Create a new main variant of TYPE. */
3300 TYPE_MAIN_VARIANT (ntype) = ntype;
3301 TYPE_NEXT_VARIANT (ntype) = 0;
3302 TYPE_READONLY (ntype) = TYPE_VOLATILE (ntype) = 0;
3304 hashcode = TYPE_HASH (TREE_CODE (ntype))
3305 + TYPE_HASH (TREE_TYPE (ntype))
3306 + attribute_hash_list (attribute);
3308 switch (TREE_CODE (ntype))
3311 hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype));
3314 hashcode += TYPE_HASH (TYPE_DOMAIN (ntype));
3317 hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype));
3320 hashcode += TYPE_HASH (TYPE_PRECISION (ntype));
3326 ntype = type_hash_canon (hashcode, ntype);
3327 ttype = build_type_variant (ntype, TYPE_READONLY (ttype),
3328 TYPE_VOLATILE (ttype));
3334 /* Return a 1 if ATTR_NAME and ATTR_ARGS is valid for either declaration DECL
3335 or type TYPE and 0 otherwise. Validity is determined the configuration
3336 macros VALID_MACHINE_DECL_ATTRIBUTE and VALID_MACHINE_TYPE_ATTRIBUTE. */
3339 valid_machine_attribute (attr_name, attr_args, decl, type)
3340 tree attr_name, attr_args;
3345 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3346 tree decl_attr_list = decl != 0 ? DECL_MACHINE_ATTRIBUTES (decl) : 0;
3348 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3349 tree type_attr_list = TYPE_ATTRIBUTES (type);
3352 if (TREE_CODE (attr_name) != IDENTIFIER_NODE)
3355 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3357 && VALID_MACHINE_DECL_ATTRIBUTE (decl, decl_attr_list, attr_name, attr_args))
3359 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3362 if (attr != NULL_TREE)
3364 /* Override existing arguments. Declarations are unique so we can
3365 modify this in place. */
3366 TREE_VALUE (attr) = attr_args;
3370 decl_attr_list = tree_cons (attr_name, attr_args, decl_attr_list);
3371 decl = build_decl_attribute_variant (decl, decl_attr_list);
3378 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3380 /* Don't apply the attribute to both the decl and the type. */;
3381 else if (VALID_MACHINE_TYPE_ATTRIBUTE (type, type_attr_list, attr_name,
3384 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3387 if (attr != NULL_TREE)
3389 /* Override existing arguments.
3390 ??? This currently works since attribute arguments are not
3391 included in `attribute_hash_list'. Something more complicated
3392 may be needed in the future. */
3393 TREE_VALUE (attr) = attr_args;
3397 /* If this is part of a declaration, create a type variant,
3398 otherwise, this is part of a type definition, so add it
3399 to the base type. */
3400 type_attr_list = tree_cons (attr_name, attr_args, type_attr_list);
3402 type = build_type_attribute_variant (type, type_attr_list);
3404 TYPE_ATTRIBUTES (type) = type_attr_list;
3407 TREE_TYPE (decl) = type;
3411 /* Handle putting a type attribute on pointer-to-function-type by putting
3412 the attribute on the function type. */
3413 else if (POINTER_TYPE_P (type)
3414 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3415 && VALID_MACHINE_TYPE_ATTRIBUTE (TREE_TYPE (type), type_attr_list,
3416 attr_name, attr_args))
3418 tree inner_type = TREE_TYPE (type);
3419 tree inner_attr_list = TYPE_ATTRIBUTES (inner_type);
3420 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3423 if (attr != NULL_TREE)
3424 TREE_VALUE (attr) = attr_args;
3427 inner_attr_list = tree_cons (attr_name, attr_args, inner_attr_list);
3428 inner_type = build_type_attribute_variant (inner_type,
3433 TREE_TYPE (decl) = build_pointer_type (inner_type);
3442 /* Return non-zero if IDENT is a valid name for attribute ATTR,
3445 We try both `text' and `__text__', ATTR may be either one. */
3446 /* ??? It might be a reasonable simplification to require ATTR to be only
3447 `text'. One might then also require attribute lists to be stored in
3448 their canonicalized form. */
3451 is_attribute_p (attr, ident)
3455 int ident_len, attr_len;
3458 if (TREE_CODE (ident) != IDENTIFIER_NODE)
3461 if (strcmp (attr, IDENTIFIER_POINTER (ident)) == 0)
3464 p = IDENTIFIER_POINTER (ident);
3465 ident_len = strlen (p);
3466 attr_len = strlen (attr);
3468 /* If ATTR is `__text__', IDENT must be `text'; and vice versa. */
3472 || attr[attr_len - 2] != '_'
3473 || attr[attr_len - 1] != '_')
3475 if (ident_len == attr_len - 4
3476 && strncmp (attr + 2, p, attr_len - 4) == 0)
3481 if (ident_len == attr_len + 4
3482 && p[0] == '_' && p[1] == '_'
3483 && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3484 && strncmp (attr, p + 2, attr_len) == 0)
3491 /* Given an attribute name and a list of attributes, return a pointer to the
3492 attribute's list element if the attribute is part of the list, or NULL_TREE
3496 lookup_attribute (attr_name, list)
3502 for (l = list; l; l = TREE_CHAIN (l))
3504 if (TREE_CODE (TREE_PURPOSE (l)) != IDENTIFIER_NODE)
3506 if (is_attribute_p (attr_name, TREE_PURPOSE (l)))
3513 /* Return an attribute list that is the union of a1 and a2. */
3516 merge_attributes (a1, a2)
3517 register tree a1, a2;
3521 /* Either one unset? Take the set one. */
3523 if (! (attributes = a1))
3526 /* One that completely contains the other? Take it. */
3528 else if (a2 && ! attribute_list_contained (a1, a2))
3530 if (attribute_list_contained (a2, a1))
3534 /* Pick the longest list, and hang on the other list. */
3535 /* ??? For the moment we punt on the issue of attrs with args. */
3537 if (list_length (a1) < list_length (a2))
3538 attributes = a2, a2 = a1;
3540 for (; a2; a2 = TREE_CHAIN (a2))
3541 if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3542 attributes) == NULL_TREE)
3544 a1 = copy_node (a2);
3545 TREE_CHAIN (a1) = attributes;
3553 /* Given types T1 and T2, merge their attributes and return
3557 merge_machine_type_attributes (t1, t2)
3560 #ifdef MERGE_MACHINE_TYPE_ATTRIBUTES
3561 return MERGE_MACHINE_TYPE_ATTRIBUTES (t1, t2);
3563 return merge_attributes (TYPE_ATTRIBUTES (t1),
3564 TYPE_ATTRIBUTES (t2));
3568 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3572 merge_machine_decl_attributes (olddecl, newdecl)
3573 tree olddecl, newdecl;
3575 #ifdef MERGE_MACHINE_DECL_ATTRIBUTES
3576 return MERGE_MACHINE_DECL_ATTRIBUTES (olddecl, newdecl);
3578 return merge_attributes (DECL_MACHINE_ATTRIBUTES (olddecl),
3579 DECL_MACHINE_ATTRIBUTES (newdecl));
3583 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
3584 and its TYPE_VOLATILE is VOLATILEP.
3586 Such variant types already made are recorded so that duplicates
3589 A variant types should never be used as the type of an expression.
3590 Always copy the variant information into the TREE_READONLY
3591 and TREE_THIS_VOLATILE of the expression, and then give the expression
3592 as its type the "main variant", the variant whose TYPE_READONLY
3593 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
3597 build_type_variant (type, constp, volatilep)
3599 int constp, volatilep;
3603 /* Treat any nonzero argument as 1. */
3605 volatilep = !!volatilep;
3607 /* Search the chain of variants to see if there is already one there just
3608 like the one we need to have. If so, use that existing one. We must
3609 preserve the TYPE_NAME, since there is code that depends on this. */
3611 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3612 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t)
3613 && TYPE_NAME (t) == TYPE_NAME (type))
3616 /* We need a new one. */
3618 t = build_type_copy (type);
3619 TYPE_READONLY (t) = constp;
3620 TYPE_VOLATILE (t) = volatilep;
3625 /* Create a new variant of TYPE, equivalent but distinct.
3626 This is so the caller can modify it. */
3629 build_type_copy (type)
3632 register tree t, m = TYPE_MAIN_VARIANT (type);
3633 register struct obstack *ambient_obstack = current_obstack;
3635 current_obstack = TYPE_OBSTACK (type);
3636 t = copy_node (type);
3637 current_obstack = ambient_obstack;
3639 TYPE_POINTER_TO (t) = 0;
3640 TYPE_REFERENCE_TO (t) = 0;
3642 /* Add this type to the chain of variants of TYPE. */
3643 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
3644 TYPE_NEXT_VARIANT (m) = t;
3649 /* Hashing of types so that we don't make duplicates.
3650 The entry point is `type_hash_canon'. */
3652 /* Each hash table slot is a bucket containing a chain
3653 of these structures. */
3657 struct type_hash *next; /* Next structure in the bucket. */
3658 int hashcode; /* Hash code of this type. */
3659 tree type; /* The type recorded here. */
3662 /* Now here is the hash table. When recording a type, it is added
3663 to the slot whose index is the hash code mod the table size.
3664 Note that the hash table is used for several kinds of types
3665 (function types, array types and array index range types, for now).
3666 While all these live in the same table, they are completely independent,
3667 and the hash code is computed differently for each of these. */
3669 #define TYPE_HASH_SIZE 59
3670 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
3672 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
3673 with types in the TREE_VALUE slots), by adding the hash codes
3674 of the individual types. */
3677 type_hash_list (list)
3680 register int hashcode;
3682 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3683 hashcode += TYPE_HASH (TREE_VALUE (tail));
3687 /* Look in the type hash table for a type isomorphic to TYPE.
3688 If one is found, return it. Otherwise return 0. */
3691 type_hash_lookup (hashcode, type)
3695 register struct type_hash *h;
3696 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
3697 if (h->hashcode == hashcode
3698 && TREE_CODE (h->type) == TREE_CODE (type)
3699 && TREE_TYPE (h->type) == TREE_TYPE (type)
3700 && attribute_list_equal (TYPE_ATTRIBUTES (h->type),
3701 TYPE_ATTRIBUTES (type))
3702 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
3703 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
3704 TYPE_MAX_VALUE (type)))
3705 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
3706 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
3707 TYPE_MIN_VALUE (type)))
3708 /* Note that TYPE_DOMAIN is TYPE_ARG_TYPES for FUNCTION_TYPE. */
3709 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
3710 || (TYPE_DOMAIN (h->type)
3711 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
3712 && TYPE_DOMAIN (type)
3713 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
3714 && type_list_equal (TYPE_DOMAIN (h->type),
3715 TYPE_DOMAIN (type)))))
3720 /* Add an entry to the type-hash-table
3721 for a type TYPE whose hash code is HASHCODE. */
3724 type_hash_add (hashcode, type)
3728 register struct type_hash *h;
3730 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
3731 h->hashcode = hashcode;
3733 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
3734 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
3737 /* Given TYPE, and HASHCODE its hash code, return the canonical
3738 object for an identical type if one already exists.
3739 Otherwise, return TYPE, and record it as the canonical object
3740 if it is a permanent object.
3742 To use this function, first create a type of the sort you want.
3743 Then compute its hash code from the fields of the type that
3744 make it different from other similar types.
3745 Then call this function and use the value.
3746 This function frees the type you pass in if it is a duplicate. */
3748 /* Set to 1 to debug without canonicalization. Never set by program. */
3749 int debug_no_type_hash = 0;
3752 type_hash_canon (hashcode, type)
3758 if (debug_no_type_hash)
3761 t1 = type_hash_lookup (hashcode, type);
3764 obstack_free (TYPE_OBSTACK (type), type);
3765 #ifdef GATHER_STATISTICS
3766 tree_node_counts[(int)t_kind]--;
3767 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
3772 /* If this is a permanent type, record it for later reuse. */
3773 if (TREE_PERMANENT (type))
3774 type_hash_add (hashcode, type);
3779 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
3780 with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
3781 by adding the hash codes of the individual attributes. */
3784 attribute_hash_list (list)
3787 register int hashcode;
3789 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3790 /* ??? Do we want to add in TREE_VALUE too? */
3791 hashcode += TYPE_HASH (TREE_PURPOSE (tail));
3795 /* Given two lists of attributes, return true if list l2 is
3796 equivalent to l1. */
3799 attribute_list_equal (l1, l2)
3802 return attribute_list_contained (l1, l2)
3803 && attribute_list_contained (l2, l1);
3806 /* Given two lists of attributes, return true if list L2 is
3807 completely contained within L1. */
3808 /* ??? This would be faster if attribute names were stored in a canonicalized
3809 form. Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
3810 must be used to show these elements are equivalent (which they are). */
3811 /* ??? It's not clear that attributes with arguments will always be handled
3815 attribute_list_contained (l1, l2)
3818 register tree t1, t2;
3820 /* First check the obvious, maybe the lists are identical. */
3824 /* Maybe the lists are similar. */
3825 for (t1 = l1, t2 = l2;
3827 && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
3828 && TREE_VALUE (t1) == TREE_VALUE (t2);
3829 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
3831 /* Maybe the lists are equal. */
3832 if (t1 == 0 && t2 == 0)
3835 for (; t2; t2 = TREE_CHAIN (t2))
3838 = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)), l1);
3840 if (attr == NULL_TREE)
3842 if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) != 1)
3849 /* Given two lists of types
3850 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
3851 return 1 if the lists contain the same types in the same order.
3852 Also, the TREE_PURPOSEs must match. */
3855 type_list_equal (l1, l2)
3858 register tree t1, t2;
3860 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
3861 if (TREE_VALUE (t1) != TREE_VALUE (t2)
3862 || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
3863 && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
3864 && (TREE_TYPE (TREE_PURPOSE (t1))
3865 == TREE_TYPE (TREE_PURPOSE (t2))))))
3871 /* Nonzero if integer constants T1 and T2
3872 represent the same constant value. */
3875 tree_int_cst_equal (t1, t2)
3880 if (t1 == 0 || t2 == 0)
3882 if (TREE_CODE (t1) == INTEGER_CST
3883 && TREE_CODE (t2) == INTEGER_CST
3884 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3885 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
3890 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
3891 The precise way of comparison depends on their data type. */
3894 tree_int_cst_lt (t1, t2)
3900 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
3901 return INT_CST_LT (t1, t2);
3902 return INT_CST_LT_UNSIGNED (t1, t2);
3905 /* Return an indication of the sign of the integer constant T.
3906 The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
3907 Note that -1 will never be returned it T's type is unsigned. */
3910 tree_int_cst_sgn (t)
3913 if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
3915 else if (TREE_UNSIGNED (TREE_TYPE (t)))
3917 else if (TREE_INT_CST_HIGH (t) < 0)
3923 /* Compare two constructor-element-type constants. Return 1 if the lists
3924 are known to be equal; otherwise return 0. */
3927 simple_cst_list_equal (l1, l2)
3930 while (l1 != NULL_TREE && l2 != NULL_TREE)
3932 if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
3935 l1 = TREE_CHAIN (l1);
3936 l2 = TREE_CHAIN (l2);
3942 /* Return truthvalue of whether T1 is the same tree structure as T2.
3943 Return 1 if they are the same.
3944 Return 0 if they are understandably different.
3945 Return -1 if either contains tree structure not understood by
3949 simple_cst_equal (t1, t2)
3952 register enum tree_code code1, code2;
3957 if (t1 == 0 || t2 == 0)
3960 code1 = TREE_CODE (t1);
3961 code2 = TREE_CODE (t2);
3963 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
3965 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3966 || code2 == NON_LVALUE_EXPR)
3967 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3969 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
3971 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3972 || code2 == NON_LVALUE_EXPR)
3973 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
3981 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3982 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
3985 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
3988 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
3989 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
3990 TREE_STRING_LENGTH (t1));
3993 if (CONSTRUCTOR_ELTS (t1) == CONSTRUCTOR_ELTS (t2))
3999 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4002 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4005 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
4008 /* Special case: if either target is an unallocated VAR_DECL,
4009 it means that it's going to be unified with whatever the
4010 TARGET_EXPR is really supposed to initialize, so treat it
4011 as being equivalent to anything. */
4012 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
4013 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
4014 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
4015 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
4016 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
4017 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
4020 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4023 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
4025 case WITH_CLEANUP_EXPR:
4026 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4029 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
4032 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
4033 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4046 /* This general rule works for most tree codes. All exceptions should be
4047 handled above. If this is a language-specific tree code, we can't
4048 trust what might be in the operand, so say we don't know
4050 if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
4053 switch (TREE_CODE_CLASS (code1))
4063 for (i=0; i<tree_code_length[(int) code1]; ++i)
4065 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
4076 /* Constructors for pointer, array and function types.
4077 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
4078 constructed by language-dependent code, not here.) */
4080 /* Construct, lay out and return the type of pointers to TO_TYPE.
4081 If such a type has already been constructed, reuse it. */
4084 build_pointer_type (to_type)
4087 register tree t = TYPE_POINTER_TO (to_type);
4089 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4094 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4095 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4096 t = make_node (POINTER_TYPE);
4099 TREE_TYPE (t) = to_type;
4101 /* Record this type as the pointer to TO_TYPE. */
4102 TYPE_POINTER_TO (to_type) = t;
4104 /* Lay out the type. This function has many callers that are concerned
4105 with expression-construction, and this simplifies them all.
4106 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
4112 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
4113 MAXVAL should be the maximum value in the domain
4114 (one less than the length of the array).
4116 The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
4117 We don't enforce this limit, that is up to caller (e.g. language front end).
4118 The limit exists because the result is a signed type and we don't handle
4119 sizes that use more than one HOST_WIDE_INT. */
4122 build_index_type (maxval)
4125 register tree itype = make_node (INTEGER_TYPE);
4127 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
4128 TYPE_MIN_VALUE (itype) = size_zero_node;
4130 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4131 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
4134 TYPE_MODE (itype) = TYPE_MODE (sizetype);
4135 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
4136 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
4137 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
4138 if (TREE_CODE (maxval) == INTEGER_CST)
4140 int maxint = (int) TREE_INT_CST_LOW (maxval);
4141 /* If the domain should be empty, make sure the maxval
4142 remains -1 and is not spoiled by truncation. */
4143 if (INT_CST_LT (maxval, integer_zero_node))
4145 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
4146 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
4148 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4154 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
4155 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
4156 low bound LOWVAL and high bound HIGHVAL.
4157 if TYPE==NULL_TREE, sizetype is used. */
4160 build_range_type (type, lowval, highval)
4161 tree type, lowval, highval;
4163 register tree itype = make_node (INTEGER_TYPE);
4165 TREE_TYPE (itype) = type;
4166 if (type == NULL_TREE)
4169 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4170 TYPE_MIN_VALUE (itype) = convert (type, lowval);
4171 TYPE_MAX_VALUE (itype) = highval ? convert (type, highval) : NULL;
4174 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
4175 TYPE_MODE (itype) = TYPE_MODE (type);
4176 TYPE_SIZE (itype) = TYPE_SIZE (type);
4177 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
4178 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
4179 if (TREE_CODE (lowval) == INTEGER_CST)
4181 HOST_WIDE_INT lowint, highint;
4184 lowint = TREE_INT_CST_LOW (lowval);
4185 if (highval && TREE_CODE (highval) == INTEGER_CST)
4186 highint = TREE_INT_CST_LOW (highval);
4188 highint = (~(unsigned HOST_WIDE_INT)0) >> 1;
4190 maxint = (int) (highint - lowint);
4191 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4197 /* Just like build_index_type, but takes lowval and highval instead
4198 of just highval (maxval). */
4201 build_index_2_type (lowval,highval)
4202 tree lowval, highval;
4204 return build_range_type (NULL_TREE, lowval, highval);
4207 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
4208 Needed because when index types are not hashed, equal index types
4209 built at different times appear distinct, even though structurally,
4213 index_type_equal (itype1, itype2)
4214 tree itype1, itype2;
4216 if (TREE_CODE (itype1) != TREE_CODE (itype2))
4218 if (TREE_CODE (itype1) == INTEGER_TYPE)
4220 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
4221 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
4222 || simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2)) != 1
4223 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
4225 if (1 == simple_cst_equal (TYPE_MIN_VALUE (itype1),
4226 TYPE_MIN_VALUE (itype2))
4227 && 1 == simple_cst_equal (TYPE_MAX_VALUE (itype1),
4228 TYPE_MAX_VALUE (itype2)))
4235 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
4236 and number of elements specified by the range of values of INDEX_TYPE.
4237 If such a type has already been constructed, reuse it. */
4240 build_array_type (elt_type, index_type)
4241 tree elt_type, index_type;
4246 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
4248 error ("arrays of functions are not meaningful");
4249 elt_type = integer_type_node;
4252 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
4253 build_pointer_type (elt_type);
4255 /* Allocate the array after the pointer type,
4256 in case we free it in type_hash_canon. */
4257 t = make_node (ARRAY_TYPE);
4258 TREE_TYPE (t) = elt_type;
4259 TYPE_DOMAIN (t) = index_type;
4261 if (index_type == 0)
4266 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
4267 t = type_hash_canon (hashcode, t);
4269 if (TYPE_SIZE (t) == 0)
4274 /* Return the TYPE of the elements comprising
4275 the innermost dimension of ARRAY. */
4278 get_inner_array_type (array)
4281 tree type = TREE_TYPE (array);
4283 while (TREE_CODE (type) == ARRAY_TYPE)
4284 type = TREE_TYPE (type);
4289 /* Construct, lay out and return
4290 the type of functions returning type VALUE_TYPE
4291 given arguments of types ARG_TYPES.
4292 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
4293 are data type nodes for the arguments of the function.
4294 If such a type has already been constructed, reuse it. */
4297 build_function_type (value_type, arg_types)
4298 tree value_type, arg_types;
4303 if (TREE_CODE (value_type) == FUNCTION_TYPE)
4305 error ("function return type cannot be function");
4306 value_type = integer_type_node;
4309 /* Make a node of the sort we want. */
4310 t = make_node (FUNCTION_TYPE);
4311 TREE_TYPE (t) = value_type;
4312 TYPE_ARG_TYPES (t) = arg_types;
4314 /* If we already have such a type, use the old one and free this one. */
4315 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
4316 t = type_hash_canon (hashcode, t);
4318 if (TYPE_SIZE (t) == 0)
4323 /* Build the node for the type of references-to-TO_TYPE. */
4326 build_reference_type (to_type)
4329 register tree t = TYPE_REFERENCE_TO (to_type);
4331 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4336 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4337 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4338 t = make_node (REFERENCE_TYPE);
4341 TREE_TYPE (t) = to_type;
4343 /* Record this type as the pointer to TO_TYPE. */
4344 TYPE_REFERENCE_TO (to_type) = t;
4351 /* Construct, lay out and return the type of methods belonging to class
4352 BASETYPE and whose arguments and values are described by TYPE.
4353 If that type exists already, reuse it.
4354 TYPE must be a FUNCTION_TYPE node. */
4357 build_method_type (basetype, type)
4358 tree basetype, type;
4363 /* Make a node of the sort we want. */
4364 t = make_node (METHOD_TYPE);
4366 if (TREE_CODE (type) != FUNCTION_TYPE)
4369 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4370 TREE_TYPE (t) = TREE_TYPE (type);
4372 /* The actual arglist for this function includes a "hidden" argument
4373 which is "this". Put it into the list of argument types. */
4376 = tree_cons (NULL_TREE,
4377 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
4379 /* If we already have such a type, use the old one and free this one. */
4380 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4381 t = type_hash_canon (hashcode, t);
4383 if (TYPE_SIZE (t) == 0)
4389 /* Construct, lay out and return the type of offsets to a value
4390 of type TYPE, within an object of type BASETYPE.
4391 If a suitable offset type exists already, reuse it. */
4394 build_offset_type (basetype, type)
4395 tree basetype, type;
4400 /* Make a node of the sort we want. */
4401 t = make_node (OFFSET_TYPE);
4403 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4404 TREE_TYPE (t) = type;
4406 /* If we already have such a type, use the old one and free this one. */
4407 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4408 t = type_hash_canon (hashcode, t);
4410 if (TYPE_SIZE (t) == 0)
4416 /* Create a complex type whose components are COMPONENT_TYPE. */
4419 build_complex_type (component_type)
4420 tree component_type;
4425 /* Make a node of the sort we want. */
4426 t = make_node (COMPLEX_TYPE);
4428 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
4429 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
4430 TYPE_READONLY (t) = TYPE_READONLY (component_type);
4432 /* If we already have such a type, use the old one and free this one. */
4433 hashcode = TYPE_HASH (component_type);
4434 t = type_hash_canon (hashcode, t);
4436 if (TYPE_SIZE (t) == 0)
4442 /* Return OP, stripped of any conversions to wider types as much as is safe.
4443 Converting the value back to OP's type makes a value equivalent to OP.
4445 If FOR_TYPE is nonzero, we return a value which, if converted to
4446 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
4448 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
4449 narrowest type that can hold the value, even if they don't exactly fit.
4450 Otherwise, bit-field references are changed to a narrower type
4451 only if they can be fetched directly from memory in that type.
4453 OP must have integer, real or enumeral type. Pointers are not allowed!
4455 There are some cases where the obvious value we could return
4456 would regenerate to OP if converted to OP's type,
4457 but would not extend like OP to wider types.
4458 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
4459 For example, if OP is (unsigned short)(signed char)-1,
4460 we avoid returning (signed char)-1 if FOR_TYPE is int,
4461 even though extending that to an unsigned short would regenerate OP,
4462 since the result of extending (signed char)-1 to (int)
4463 is different from (int) OP. */
4466 get_unwidened (op, for_type)
4470 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
4471 register tree type = TREE_TYPE (op);
4472 register unsigned final_prec
4473 = TYPE_PRECISION (for_type != 0 ? for_type : type);
4475 = (for_type != 0 && for_type != type
4476 && final_prec > TYPE_PRECISION (type)
4477 && TREE_UNSIGNED (type));
4478 register tree win = op;
4480 while (TREE_CODE (op) == NOP_EXPR)
4482 register int bitschange
4483 = TYPE_PRECISION (TREE_TYPE (op))
4484 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4486 /* Truncations are many-one so cannot be removed.
4487 Unless we are later going to truncate down even farther. */
4489 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
4492 /* See what's inside this conversion. If we decide to strip it,
4494 op = TREE_OPERAND (op, 0);
4496 /* If we have not stripped any zero-extensions (uns is 0),
4497 we can strip any kind of extension.
4498 If we have previously stripped a zero-extension,
4499 only zero-extensions can safely be stripped.
4500 Any extension can be stripped if the bits it would produce
4501 are all going to be discarded later by truncating to FOR_TYPE. */
4505 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
4507 /* TREE_UNSIGNED says whether this is a zero-extension.
4508 Let's avoid computing it if it does not affect WIN
4509 and if UNS will not be needed again. */
4510 if ((uns || TREE_CODE (op) == NOP_EXPR)
4511 && TREE_UNSIGNED (TREE_TYPE (op)))
4519 if (TREE_CODE (op) == COMPONENT_REF
4520 /* Since type_for_size always gives an integer type. */
4521 && TREE_CODE (type) != REAL_TYPE
4522 /* Don't crash if field not laid out yet. */
4523 && DECL_SIZE (TREE_OPERAND (op, 1)) != 0)
4525 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4526 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
4528 /* We can get this structure field in the narrowest type it fits in.
4529 If FOR_TYPE is 0, do this only for a field that matches the
4530 narrower type exactly and is aligned for it
4531 The resulting extension to its nominal type (a fullword type)
4532 must fit the same conditions as for other extensions. */
4534 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4535 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
4536 && (! uns || final_prec <= innerprec
4537 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4540 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4541 TREE_OPERAND (op, 1));
4542 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4543 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4544 TREE_RAISES (win) = TREE_RAISES (op);
4550 /* Return OP or a simpler expression for a narrower value
4551 which can be sign-extended or zero-extended to give back OP.
4552 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
4553 or 0 if the value should be sign-extended. */
4556 get_narrower (op, unsignedp_ptr)
4560 register int uns = 0;
4562 register tree win = op;
4564 while (TREE_CODE (op) == NOP_EXPR)
4566 register int bitschange
4567 = TYPE_PRECISION (TREE_TYPE (op))
4568 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4570 /* Truncations are many-one so cannot be removed. */
4574 /* See what's inside this conversion. If we decide to strip it,
4576 op = TREE_OPERAND (op, 0);
4580 /* An extension: the outermost one can be stripped,
4581 but remember whether it is zero or sign extension. */
4583 uns = TREE_UNSIGNED (TREE_TYPE (op));
4584 /* Otherwise, if a sign extension has been stripped,
4585 only sign extensions can now be stripped;
4586 if a zero extension has been stripped, only zero-extensions. */
4587 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
4591 else /* bitschange == 0 */
4593 /* A change in nominal type can always be stripped, but we must
4594 preserve the unsignedness. */
4596 uns = TREE_UNSIGNED (TREE_TYPE (op));
4603 if (TREE_CODE (op) == COMPONENT_REF
4604 /* Since type_for_size always gives an integer type. */
4605 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
4607 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4608 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
4610 /* We can get this structure field in a narrower type that fits it,
4611 but the resulting extension to its nominal type (a fullword type)
4612 must satisfy the same conditions as for other extensions.
4614 Do this only for fields that are aligned (not bit-fields),
4615 because when bit-field insns will be used there is no
4616 advantage in doing this. */
4618 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4619 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
4620 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4624 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
4625 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4626 TREE_OPERAND (op, 1));
4627 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4628 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4629 TREE_RAISES (win) = TREE_RAISES (op);
4632 *unsignedp_ptr = uns;
4636 /* Nonzero if integer constant C has a value that is permissible
4637 for type TYPE (an INTEGER_TYPE). */
4640 int_fits_type_p (c, type)
4643 if (TREE_UNSIGNED (type))
4644 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4645 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
4646 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4647 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
4648 /* Negative ints never fit unsigned types. */
4649 && ! (TREE_INT_CST_HIGH (c) < 0
4650 && ! TREE_UNSIGNED (TREE_TYPE (c))));
4652 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4653 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
4654 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4655 && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
4656 /* Unsigned ints with top bit set never fit signed types. */
4657 && ! (TREE_INT_CST_HIGH (c) < 0
4658 && TREE_UNSIGNED (TREE_TYPE (c))));
4661 /* Return the innermost context enclosing DECL that is
4662 a FUNCTION_DECL, or zero if none. */
4665 decl_function_context (decl)
4670 if (TREE_CODE (decl) == ERROR_MARK)
4673 if (TREE_CODE (decl) == SAVE_EXPR)
4674 context = SAVE_EXPR_CONTEXT (decl);
4676 context = DECL_CONTEXT (decl);
4678 while (context && TREE_CODE (context) != FUNCTION_DECL)
4680 if (TREE_CODE_CLASS (TREE_CODE (context)) == 't')
4681 context = TYPE_CONTEXT (context);
4682 else if (TREE_CODE_CLASS (TREE_CODE (context)) == 'd')
4683 context = DECL_CONTEXT (context);
4684 else if (TREE_CODE (context) == BLOCK)
4685 context = BLOCK_SUPERCONTEXT (context);
4687 /* Unhandled CONTEXT !? */
4694 /* Return the innermost context enclosing DECL that is
4695 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
4696 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
4699 decl_type_context (decl)
4702 tree context = DECL_CONTEXT (decl);
4706 if (TREE_CODE (context) == RECORD_TYPE
4707 || TREE_CODE (context) == UNION_TYPE
4708 || TREE_CODE (context) == QUAL_UNION_TYPE)
4710 if (TREE_CODE (context) == TYPE_DECL
4711 || TREE_CODE (context) == FUNCTION_DECL)
4712 context = DECL_CONTEXT (context);
4713 else if (TREE_CODE (context) == BLOCK)
4714 context = BLOCK_SUPERCONTEXT (context);
4716 /* Unhandled CONTEXT!? */
4722 /* Print debugging information about the size of the
4723 toplev_inline_obstacks. */
4726 print_inline_obstack_statistics ()
4728 struct simple_obstack_stack *current = toplev_inline_obstacks;
4733 for (; current; current = current->next, ++n_obstacks)
4735 struct obstack *o = current->obstack;
4736 struct _obstack_chunk *chunk = o->chunk;
4738 n_alloc += o->next_free - chunk->contents;
4739 chunk = chunk->prev;
4741 for (; chunk; chunk = chunk->prev, ++n_chunks)
4742 n_alloc += chunk->limit - &chunk->contents[0];
4744 fprintf (stderr, "inline obstacks: %d obstacks, %d bytes, %d chunks\n",
4745 n_obstacks, n_alloc, n_chunks);
4748 /* Print debugging information about the obstack O, named STR. */
4751 print_obstack_statistics (str, o)
4755 struct _obstack_chunk *chunk = o->chunk;
4759 n_alloc += o->next_free - chunk->contents;
4760 chunk = chunk->prev;
4764 n_alloc += chunk->limit - &chunk->contents[0];
4765 chunk = chunk->prev;
4767 fprintf (stderr, "obstack %s: %u bytes, %d chunks\n",
4768 str, n_alloc, n_chunks);
4771 /* Print debugging information about tree nodes generated during the compile,
4772 and any language-specific information. */
4775 dump_tree_statistics ()
4777 #ifdef GATHER_STATISTICS
4779 int total_nodes, total_bytes;
4782 fprintf (stderr, "\n??? tree nodes created\n\n");
4783 #ifdef GATHER_STATISTICS
4784 fprintf (stderr, "Kind Nodes Bytes\n");
4785 fprintf (stderr, "-------------------------------------\n");
4786 total_nodes = total_bytes = 0;
4787 for (i = 0; i < (int) all_kinds; i++)
4789 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
4790 tree_node_counts[i], tree_node_sizes[i]);
4791 total_nodes += tree_node_counts[i];
4792 total_bytes += tree_node_sizes[i];
4794 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
4795 fprintf (stderr, "-------------------------------------\n");
4796 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
4797 fprintf (stderr, "-------------------------------------\n");
4799 fprintf (stderr, "(No per-node statistics)\n");
4801 print_obstack_statistics ("permanent_obstack", &permanent_obstack);
4802 print_obstack_statistics ("maybepermanent_obstack", &maybepermanent_obstack);
4803 print_obstack_statistics ("temporary_obstack", &temporary_obstack);
4804 print_obstack_statistics ("momentary_obstack", &momentary_obstack);
4805 print_obstack_statistics ("temp_decl_obstack", &temp_decl_obstack);
4806 print_inline_obstack_statistics ();
4807 print_lang_statistics ();
4810 #define FILE_FUNCTION_PREFIX_LEN 9
4812 #ifndef NO_DOLLAR_IN_LABEL
4813 #define FILE_FUNCTION_FORMAT "_GLOBAL_$%s$%s"
4814 #else /* NO_DOLLAR_IN_LABEL */
4815 #ifndef NO_DOT_IN_LABEL
4816 #define FILE_FUNCTION_FORMAT "_GLOBAL_.%s.%s"
4817 #else /* NO_DOT_IN_LABEL */
4818 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
4819 #endif /* NO_DOT_IN_LABEL */
4820 #endif /* NO_DOLLAR_IN_LABEL */
4822 extern char * first_global_object_name;
4823 extern char * weak_global_object_name;
4825 /* TYPE is some string to identify this function to the linker or
4829 get_file_function_name_long (type)
4835 if (first_global_object_name)
4836 p = first_global_object_name;
4837 else if (weak_global_object_name)
4838 p = weak_global_object_name;
4839 else if (main_input_filename)
4840 p = main_input_filename;
4844 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)
4847 /* Set up the name of the file-level functions we may need. */
4848 /* Use a global object (which is already required to be unique over
4849 the program) rather than the file name (which imposes extra
4850 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
4851 sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
4853 /* Don't need to pull weird characters out of global names. */
4854 if (p != first_global_object_name)
4856 for (p = buf+11; *p; p++)
4857 if (! ((*p >= '0' && *p <= '9')
4858 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
4859 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
4863 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
4866 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
4869 || (*p >= 'A' && *p <= 'Z')
4870 || (*p >= 'a' && *p <= 'z')))
4874 return get_identifier (buf);
4877 /* If KIND=='I', return a suitable global initializer (constructor) name.
4878 If KIND=='D', return a suitable global clean-up (destructor) name. */
4881 get_file_function_name (kind)
4888 return get_file_function_name_long (p);
4892 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4893 The result is placed in BUFFER (which has length BIT_SIZE),
4894 with one bit in each char ('\000' or '\001').
4896 If the constructor is constant, NULL_TREE is returned.
4897 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4900 get_set_constructor_bits (init, buffer, bit_size)
4907 HOST_WIDE_INT domain_min
4908 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (init))));
4909 tree non_const_bits = NULL_TREE;
4910 for (i = 0; i < bit_size; i++)
4913 for (vals = TREE_OPERAND (init, 1);
4914 vals != NULL_TREE; vals = TREE_CHAIN (vals))
4916 if (TREE_CODE (TREE_VALUE (vals)) != INTEGER_CST
4917 || (TREE_PURPOSE (vals) != NULL_TREE
4918 && TREE_CODE (TREE_PURPOSE (vals)) != INTEGER_CST))
4920 = tree_cons (TREE_PURPOSE (vals), TREE_VALUE (vals), non_const_bits);
4921 else if (TREE_PURPOSE (vals) != NULL_TREE)
4923 /* Set a range of bits to ones. */
4924 HOST_WIDE_INT lo_index
4925 = TREE_INT_CST_LOW (TREE_PURPOSE (vals)) - domain_min;
4926 HOST_WIDE_INT hi_index
4927 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4928 if (lo_index < 0 || lo_index >= bit_size
4929 || hi_index < 0 || hi_index >= bit_size)
4931 for ( ; lo_index <= hi_index; lo_index++)
4932 buffer[lo_index] = 1;
4936 /* Set a single bit to one. */
4938 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4939 if (index < 0 || index >= bit_size)
4941 error ("invalid initializer for bit string");
4947 return non_const_bits;
4950 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4951 The result is placed in BUFFER (which is an array of bytes).
4952 If the constructor is constant, NULL_TREE is returned.
4953 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4956 get_set_constructor_bytes (init, buffer, wd_size)
4958 unsigned char *buffer;
4962 int set_word_size = BITS_PER_UNIT;
4963 int bit_size = wd_size * set_word_size;
4965 unsigned char *bytep = buffer;
4966 char *bit_buffer = (char *) alloca(bit_size);
4967 tree non_const_bits = get_set_constructor_bits (init, bit_buffer, bit_size);
4969 for (i = 0; i < wd_size; i++)
4972 for (i = 0; i < bit_size; i++)
4976 if (BYTES_BIG_ENDIAN)
4977 *bytep |= (1 << (set_word_size - 1 - bit_pos));
4979 *bytep |= 1 << bit_pos;
4982 if (bit_pos >= set_word_size)
4983 bit_pos = 0, bytep++;
4985 return non_const_bits;
4988 #ifdef ENABLE_CHECKING
4990 /* Complain if the tree code does not match the expected one.
4991 NODE is the tree node in question, CODE is the expected tree code,
4992 and FILE and LINE are the filename and line number, respectively,
4993 of the line on which the check was done. If NONFATAL is nonzero,
4994 don't abort if the reference is invalid; instead, return 0.
4995 If the reference is valid, return NODE. */
4998 tree_check (node, code, file, line, nofatal)
5000 enum tree_code code;
5005 if (TREE_CODE (node) == code)
5010 fatal ("%s:%d: Expect %s, have %s\n", file, line,
5011 tree_code_name[code], tree_code_name[TREE_CODE (node)]);
5014 /* Similar to above, except that we check for a class of tree
5015 code, given in CL. */
5018 tree_class_check (node, cl, file, line, nofatal)
5025 if (TREE_CODE_CLASS (TREE_CODE (node)) == cl)
5030 fatal ("%s:%d: Expect '%c', have '%s'\n", file, line,
5031 cl, tree_code_name[TREE_CODE (node)]);
5034 /* Likewise, but complain if the tree node is not an expression. */
5037 expr_check (node, ignored, file, line, nofatal)
5044 switch (TREE_CODE_CLASS (TREE_CODE (node)))
5058 fatal ("%s:%d: Expect expression, have '%s'\n", file, line,
5059 tree_code_name[TREE_CODE (node)]);
5066 /* Return the alias set for T, which may be either a type or an
5069 int get_alias_set (t)
5072 if (!flag_strict_aliasing || !lang_get_alias_set)
5073 /* If we're not doing any lanaguage-specific alias analysis, just
5074 assume everything aliases everything else. */
5077 return (*lang_get_alias_set) (t);