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. */
46 #define obstack_chunk_alloc xmalloc
47 #define obstack_chunk_free free
48 /* obstack.[ch] explicitly declined to prototype this. */
49 extern int _obstack_allocated_p PROTO ((struct obstack *h, GENERIC_PTR obj));
51 /* Tree nodes of permanent duration are allocated in this obstack.
52 They are the identifier nodes, and everything outside of
53 the bodies and parameters of function definitions. */
55 struct obstack permanent_obstack;
57 /* The initial RTL, and all ..._TYPE nodes, in a function
58 are allocated in this obstack. Usually they are freed at the
59 end of the function, but if the function is inline they are saved.
60 For top-level functions, this is maybepermanent_obstack.
61 Separate obstacks are made for nested functions. */
63 struct obstack *function_maybepermanent_obstack;
65 /* This is the function_maybepermanent_obstack for top-level functions. */
67 struct obstack maybepermanent_obstack;
69 /* This is a list of function_maybepermanent_obstacks for top-level inline
70 functions that are compiled in the middle of compiling other functions. */
72 struct simple_obstack_stack *toplev_inline_obstacks;
74 /* Former elements of toplev_inline_obstacks that have been recycled. */
76 struct simple_obstack_stack *extra_inline_obstacks;
78 /* This is a list of function_maybepermanent_obstacks for inline functions
79 nested in the current function that were compiled in the middle of
80 compiling other functions. */
82 struct simple_obstack_stack *inline_obstacks;
84 /* The contents of the current function definition are allocated
85 in this obstack, and all are freed at the end of the function.
86 For top-level functions, this is temporary_obstack.
87 Separate obstacks are made for nested functions. */
89 struct obstack *function_obstack;
91 /* This is used for reading initializers of global variables. */
93 struct obstack temporary_obstack;
95 /* The tree nodes of an expression are allocated
96 in this obstack, and all are freed at the end of the expression. */
98 struct obstack momentary_obstack;
100 /* The tree nodes of a declarator are allocated
101 in this obstack, and all are freed when the declarator
104 static struct obstack temp_decl_obstack;
106 /* This points at either permanent_obstack
107 or the current function_maybepermanent_obstack. */
109 struct obstack *saveable_obstack;
111 /* This is same as saveable_obstack during parse and expansion phase;
112 it points to the current function's obstack during optimization.
113 This is the obstack to be used for creating rtl objects. */
115 struct obstack *rtl_obstack;
117 /* This points at either permanent_obstack or the current function_obstack. */
119 struct obstack *current_obstack;
121 /* This points at either permanent_obstack or the current function_obstack
122 or momentary_obstack. */
124 struct obstack *expression_obstack;
126 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
130 struct obstack_stack *next;
131 struct obstack *current;
132 struct obstack *saveable;
133 struct obstack *expression;
137 struct obstack_stack *obstack_stack;
139 /* Obstack for allocating struct obstack_stack entries. */
141 static struct obstack obstack_stack_obstack;
143 /* Addresses of first objects in some obstacks.
144 This is for freeing their entire contents. */
145 char *maybepermanent_firstobj;
146 char *temporary_firstobj;
147 char *momentary_firstobj;
148 char *temp_decl_firstobj;
150 /* This is used to preserve objects (mainly array initializers) that need to
151 live until the end of the current function, but no further. */
152 char *momentary_function_firstobj;
154 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
156 int all_types_permanent;
158 /* Stack of places to restore the momentary obstack back to. */
160 struct momentary_level
162 /* Pointer back to previous such level. */
163 struct momentary_level *prev;
164 /* First object allocated within this level. */
166 /* Value of expression_obstack saved at entry to this level. */
167 struct obstack *obstack;
170 struct momentary_level *momentary_stack;
172 /* Table indexed by tree code giving a string containing a character
173 classifying the tree code. Possibilities are
174 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
176 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
178 char tree_code_type[MAX_TREE_CODES] = {
183 /* Table indexed by tree code giving number of expression
184 operands beyond the fixed part of the node structure.
185 Not used for types or decls. */
187 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
189 int tree_code_length[MAX_TREE_CODES] = {
194 /* Names of tree components.
195 Used for printing out the tree and error messages. */
196 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
198 char *tree_code_name[MAX_TREE_CODES] = {
203 /* Statistics-gathering stuff. */
224 int tree_node_counts[(int)all_kinds];
225 int tree_node_sizes[(int)all_kinds];
226 int id_string_size = 0;
228 char *tree_node_kind_names[] = {
246 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
248 #define MAX_HASH_TABLE 1009
249 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
251 /* 0 while creating built-in identifiers. */
252 static int do_identifier_warnings;
254 /* Unique id for next decl created. */
255 static int next_decl_uid;
256 /* Unique id for next type created. */
257 static int next_type_uid = 1;
259 /* The language-specific function for alias analysis. If NULL, the
260 language does not do any special alias analysis. */
261 int (*lang_get_alias_set) PROTO((tree));
263 /* Here is how primitive or already-canonicalized types' hash
265 #define TYPE_HASH(TYPE) ((unsigned long) (TYPE) & 0777777)
267 static void set_type_quals PROTO((tree, int));
268 static void append_random_chars PROTO((char *));
270 extern char *mode_name[];
272 void gcc_obstack_init ();
274 /* Init the principal obstacks. */
279 gcc_obstack_init (&obstack_stack_obstack);
280 gcc_obstack_init (&permanent_obstack);
282 gcc_obstack_init (&temporary_obstack);
283 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
284 gcc_obstack_init (&momentary_obstack);
285 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
286 momentary_function_firstobj = momentary_firstobj;
287 gcc_obstack_init (&maybepermanent_obstack);
288 maybepermanent_firstobj
289 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
290 gcc_obstack_init (&temp_decl_obstack);
291 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
293 function_obstack = &temporary_obstack;
294 function_maybepermanent_obstack = &maybepermanent_obstack;
295 current_obstack = &permanent_obstack;
296 expression_obstack = &permanent_obstack;
297 rtl_obstack = saveable_obstack = &permanent_obstack;
299 /* Init the hash table of identifiers. */
300 bzero ((char *) hash_table, sizeof hash_table);
304 gcc_obstack_init (obstack)
305 struct obstack *obstack;
307 /* Let particular systems override the size of a chunk. */
308 #ifndef OBSTACK_CHUNK_SIZE
309 #define OBSTACK_CHUNK_SIZE 0
311 /* Let them override the alloc and free routines too. */
312 #ifndef OBSTACK_CHUNK_ALLOC
313 #define OBSTACK_CHUNK_ALLOC xmalloc
315 #ifndef OBSTACK_CHUNK_FREE
316 #define OBSTACK_CHUNK_FREE free
318 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
319 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
320 (void (*) ()) OBSTACK_CHUNK_FREE);
323 /* Save all variables describing the current status into the structure *P.
324 This is used before starting a nested function.
326 CONTEXT is the decl_function_context for the function we're about to
327 compile; if it isn't current_function_decl, we have to play some games. */
330 save_tree_status (p, context)
334 p->all_types_permanent = all_types_permanent;
335 p->momentary_stack = momentary_stack;
336 p->maybepermanent_firstobj = maybepermanent_firstobj;
337 p->temporary_firstobj = temporary_firstobj;
338 p->momentary_firstobj = momentary_firstobj;
339 p->momentary_function_firstobj = momentary_function_firstobj;
340 p->function_obstack = function_obstack;
341 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
342 p->current_obstack = current_obstack;
343 p->expression_obstack = expression_obstack;
344 p->saveable_obstack = saveable_obstack;
345 p->rtl_obstack = rtl_obstack;
346 p->inline_obstacks = inline_obstacks;
348 if (context == current_function_decl)
349 /* Objects that need to be saved in this function can be in the nonsaved
350 obstack of the enclosing function since they can't possibly be needed
351 once it has returned. */
352 function_maybepermanent_obstack = function_obstack;
355 /* We're compiling a function which isn't nested in the current
356 function. We need to create a new maybepermanent_obstack for this
357 function, since it can't go onto any of the existing obstacks. */
358 struct simple_obstack_stack **head;
359 struct simple_obstack_stack *current;
361 if (context == NULL_TREE)
362 head = &toplev_inline_obstacks;
365 struct function *f = find_function_data (context);
366 head = &f->inline_obstacks;
369 if (context == NULL_TREE && extra_inline_obstacks)
371 current = extra_inline_obstacks;
372 extra_inline_obstacks = current->next;
376 current = ((struct simple_obstack_stack *)
377 xmalloc (sizeof (struct simple_obstack_stack)));
380 = (struct obstack *) xmalloc (sizeof (struct obstack));
381 gcc_obstack_init (current->obstack);
384 function_maybepermanent_obstack = current->obstack;
386 current->next = *head;
390 maybepermanent_firstobj
391 = (char *) obstack_finish (function_maybepermanent_obstack);
393 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
394 gcc_obstack_init (function_obstack);
396 current_obstack = &permanent_obstack;
397 expression_obstack = &permanent_obstack;
398 rtl_obstack = saveable_obstack = &permanent_obstack;
400 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
401 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
402 momentary_function_firstobj = momentary_firstobj;
405 /* Restore all variables describing the current status from the structure *P.
406 This is used after a nested function. */
409 restore_tree_status (p, context)
413 all_types_permanent = p->all_types_permanent;
414 momentary_stack = p->momentary_stack;
416 obstack_free (&momentary_obstack, momentary_function_firstobj);
418 /* Free saveable storage used by the function just compiled and not
421 CAUTION: This is in function_obstack of the containing function.
422 So we must be sure that we never allocate from that obstack during
423 the compilation of a nested function if we expect it to survive
424 past the nested function's end. */
425 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
427 /* If we were compiling a toplevel function, we can free this space now. */
428 if (context == NULL_TREE)
430 obstack_free (&temporary_obstack, temporary_firstobj);
431 obstack_free (&momentary_obstack, momentary_function_firstobj);
434 /* If we were compiling a toplevel function that we don't actually want
435 to save anything from, return the obstack to the pool. */
436 if (context == NULL_TREE
437 && obstack_empty_p (function_maybepermanent_obstack))
439 struct simple_obstack_stack *current, **p = &toplev_inline_obstacks;
443 while ((*p)->obstack != function_maybepermanent_obstack)
448 current->next = extra_inline_obstacks;
449 extra_inline_obstacks = current;
453 obstack_free (function_obstack, 0);
454 free (function_obstack);
456 temporary_firstobj = p->temporary_firstobj;
457 momentary_firstobj = p->momentary_firstobj;
458 momentary_function_firstobj = p->momentary_function_firstobj;
459 maybepermanent_firstobj = p->maybepermanent_firstobj;
460 function_obstack = p->function_obstack;
461 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
462 current_obstack = p->current_obstack;
463 expression_obstack = p->expression_obstack;
464 saveable_obstack = p->saveable_obstack;
465 rtl_obstack = p->rtl_obstack;
466 inline_obstacks = p->inline_obstacks;
469 /* Start allocating on the temporary (per function) obstack.
470 This is done in start_function before parsing the function body,
471 and before each initialization at top level, and to go back
472 to temporary allocation after doing permanent_allocation. */
475 temporary_allocation ()
477 /* Note that function_obstack at top level points to temporary_obstack.
478 But within a nested function context, it is a separate obstack. */
479 current_obstack = function_obstack;
480 expression_obstack = function_obstack;
481 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
486 /* Start allocating on the permanent obstack but don't
487 free the temporary data. After calling this, call
488 `permanent_allocation' to fully resume permanent allocation status. */
491 end_temporary_allocation ()
493 current_obstack = &permanent_obstack;
494 expression_obstack = &permanent_obstack;
495 rtl_obstack = saveable_obstack = &permanent_obstack;
498 /* Resume allocating on the temporary obstack, undoing
499 effects of `end_temporary_allocation'. */
502 resume_temporary_allocation ()
504 current_obstack = function_obstack;
505 expression_obstack = function_obstack;
506 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
509 /* While doing temporary allocation, switch to allocating in such a
510 way as to save all nodes if the function is inlined. Call
511 resume_temporary_allocation to go back to ordinary temporary
515 saveable_allocation ()
517 /* Note that function_obstack at top level points to temporary_obstack.
518 But within a nested function context, it is a separate obstack. */
519 expression_obstack = current_obstack = saveable_obstack;
522 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
523 recording the previously current obstacks on a stack.
524 This does not free any storage in any obstack. */
527 push_obstacks (current, saveable)
528 struct obstack *current, *saveable;
530 struct obstack_stack *p
531 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
532 (sizeof (struct obstack_stack)));
534 p->current = current_obstack;
535 p->saveable = saveable_obstack;
536 p->expression = expression_obstack;
537 p->rtl = rtl_obstack;
538 p->next = obstack_stack;
541 current_obstack = current;
542 expression_obstack = current;
543 rtl_obstack = saveable_obstack = saveable;
546 /* Save the current set of obstacks, but don't change them. */
549 push_obstacks_nochange ()
551 struct obstack_stack *p
552 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
553 (sizeof (struct obstack_stack)));
555 p->current = current_obstack;
556 p->saveable = saveable_obstack;
557 p->expression = expression_obstack;
558 p->rtl = rtl_obstack;
559 p->next = obstack_stack;
563 /* Pop the obstack selection stack. */
568 struct obstack_stack *p = obstack_stack;
569 obstack_stack = p->next;
571 current_obstack = p->current;
572 saveable_obstack = p->saveable;
573 expression_obstack = p->expression;
574 rtl_obstack = p->rtl;
576 obstack_free (&obstack_stack_obstack, p);
579 /* Nonzero if temporary allocation is currently in effect.
580 Zero if currently doing permanent allocation. */
583 allocation_temporary_p ()
585 return current_obstack != &permanent_obstack;
588 /* Go back to allocating on the permanent obstack
589 and free everything in the temporary obstack.
591 FUNCTION_END is true only if we have just finished compiling a function.
592 In that case, we also free preserved initial values on the momentary
596 permanent_allocation (function_end)
599 /* Free up previous temporary obstack data */
600 obstack_free (&temporary_obstack, temporary_firstobj);
603 obstack_free (&momentary_obstack, momentary_function_firstobj);
604 momentary_firstobj = momentary_function_firstobj;
607 obstack_free (&momentary_obstack, momentary_firstobj);
608 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
609 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
611 /* Free up the maybepermanent_obstacks for any of our nested functions
612 which were compiled at a lower level. */
613 while (inline_obstacks)
615 struct simple_obstack_stack *current = inline_obstacks;
616 inline_obstacks = current->next;
617 obstack_free (current->obstack, 0);
618 free (current->obstack);
622 current_obstack = &permanent_obstack;
623 expression_obstack = &permanent_obstack;
624 rtl_obstack = saveable_obstack = &permanent_obstack;
627 /* Save permanently everything on the maybepermanent_obstack. */
632 maybepermanent_firstobj
633 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
637 preserve_initializer ()
639 struct momentary_level *tem;
643 = (char *) obstack_alloc (&temporary_obstack, 0);
644 maybepermanent_firstobj
645 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
647 old_momentary = momentary_firstobj;
649 = (char *) obstack_alloc (&momentary_obstack, 0);
650 if (momentary_firstobj != old_momentary)
651 for (tem = momentary_stack; tem; tem = tem->prev)
652 tem->base = momentary_firstobj;
655 /* Start allocating new rtl in current_obstack.
656 Use resume_temporary_allocation
657 to go back to allocating rtl in saveable_obstack. */
660 rtl_in_current_obstack ()
662 rtl_obstack = current_obstack;
665 /* Start allocating rtl from saveable_obstack. Intended to be used after
666 a call to push_obstacks_nochange. */
669 rtl_in_saveable_obstack ()
671 rtl_obstack = saveable_obstack;
674 /* Allocate SIZE bytes in the current obstack
675 and return a pointer to them.
676 In practice the current obstack is always the temporary one. */
682 return (char *) obstack_alloc (current_obstack, size);
685 /* Free the object PTR in the current obstack
686 as well as everything allocated since PTR.
687 In practice the current obstack is always the temporary one. */
693 obstack_free (current_obstack, ptr);
696 /* Allocate SIZE bytes in the permanent obstack
697 and return a pointer to them. */
703 return (char *) obstack_alloc (&permanent_obstack, size);
706 /* Allocate NELEM items of SIZE bytes in the permanent obstack
707 and return a pointer to them. The storage is cleared before
708 returning the value. */
711 perm_calloc (nelem, size)
715 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
716 bzero (rval, nelem * size);
720 /* Allocate SIZE bytes in the saveable obstack
721 and return a pointer to them. */
727 return (char *) obstack_alloc (saveable_obstack, size);
730 /* Allocate SIZE bytes in the expression obstack
731 and return a pointer to them. */
737 return (char *) obstack_alloc (expression_obstack, size);
740 /* Print out which obstack an object is in. */
743 print_obstack_name (object, file, prefix)
748 struct obstack *obstack = NULL;
749 char *obstack_name = NULL;
752 for (p = outer_function_chain; p; p = p->next)
754 if (_obstack_allocated_p (p->function_obstack, object))
756 obstack = p->function_obstack;
757 obstack_name = "containing function obstack";
759 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
761 obstack = p->function_maybepermanent_obstack;
762 obstack_name = "containing function maybepermanent obstack";
766 if (_obstack_allocated_p (&obstack_stack_obstack, object))
768 obstack = &obstack_stack_obstack;
769 obstack_name = "obstack_stack_obstack";
771 else if (_obstack_allocated_p (function_obstack, object))
773 obstack = function_obstack;
774 obstack_name = "function obstack";
776 else if (_obstack_allocated_p (&permanent_obstack, object))
778 obstack = &permanent_obstack;
779 obstack_name = "permanent_obstack";
781 else if (_obstack_allocated_p (&momentary_obstack, object))
783 obstack = &momentary_obstack;
784 obstack_name = "momentary_obstack";
786 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
788 obstack = function_maybepermanent_obstack;
789 obstack_name = "function maybepermanent obstack";
791 else if (_obstack_allocated_p (&temp_decl_obstack, object))
793 obstack = &temp_decl_obstack;
794 obstack_name = "temp_decl_obstack";
797 /* Check to see if the object is in the free area of the obstack. */
800 if (object >= obstack->next_free
801 && object < obstack->chunk_limit)
802 fprintf (file, "%s in free portion of obstack %s",
803 prefix, obstack_name);
805 fprintf (file, "%s allocated from %s", prefix, obstack_name);
808 fprintf (file, "%s not allocated from any obstack", prefix);
812 debug_obstack (object)
815 print_obstack_name (object, stderr, "object");
816 fprintf (stderr, ".\n");
819 /* Return 1 if OBJ is in the permanent obstack.
820 This is slow, and should be used only for debugging.
821 Use TREE_PERMANENT for other purposes. */
824 object_permanent_p (obj)
827 return _obstack_allocated_p (&permanent_obstack, obj);
830 /* Start a level of momentary allocation.
831 In C, each compound statement has its own level
832 and that level is freed at the end of each statement.
833 All expression nodes are allocated in the momentary allocation level. */
838 struct momentary_level *tem
839 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
840 sizeof (struct momentary_level));
841 tem->prev = momentary_stack;
842 tem->base = (char *) obstack_base (&momentary_obstack);
843 tem->obstack = expression_obstack;
844 momentary_stack = tem;
845 expression_obstack = &momentary_obstack;
848 /* Set things up so the next clear_momentary will only clear memory
849 past our present position in momentary_obstack. */
852 preserve_momentary ()
854 momentary_stack->base = (char *) obstack_base (&momentary_obstack);
857 /* Free all the storage in the current momentary-allocation level.
858 In C, this happens at the end of each statement. */
863 obstack_free (&momentary_obstack, momentary_stack->base);
866 /* Discard a level of momentary allocation.
867 In C, this happens at the end of each compound statement.
868 Restore the status of expression node allocation
869 that was in effect before this level was created. */
874 struct momentary_level *tem = momentary_stack;
875 momentary_stack = tem->prev;
876 expression_obstack = tem->obstack;
877 /* We can't free TEM from the momentary_obstack, because there might
878 be objects above it which have been saved. We can free back to the
879 stack of the level we are popping off though. */
880 obstack_free (&momentary_obstack, tem->base);
883 /* Pop back to the previous level of momentary allocation,
884 but don't free any momentary data just yet. */
887 pop_momentary_nofree ()
889 struct momentary_level *tem = momentary_stack;
890 momentary_stack = tem->prev;
891 expression_obstack = tem->obstack;
894 /* Call when starting to parse a declaration:
895 make expressions in the declaration last the length of the function.
896 Returns an argument that should be passed to resume_momentary later. */
901 register int tem = expression_obstack == &momentary_obstack;
902 expression_obstack = saveable_obstack;
906 /* Call when finished parsing a declaration:
907 restore the treatment of node-allocation that was
908 in effect before the suspension.
909 YES should be the value previously returned by suspend_momentary. */
912 resume_momentary (yes)
916 expression_obstack = &momentary_obstack;
919 /* Init the tables indexed by tree code.
920 Note that languages can add to these tables to define their own codes. */
928 /* Return a newly allocated node of code CODE.
929 Initialize the node's unique id and its TREE_PERMANENT flag.
930 For decl and type nodes, some other fields are initialized.
931 The rest of the node is initialized to zero.
933 Achoo! I got a code in the node. */
940 register int type = TREE_CODE_CLASS (code);
941 register int length = 0;
942 register struct obstack *obstack = current_obstack;
944 #ifdef GATHER_STATISTICS
945 register tree_node_kind kind;
950 case 'd': /* A decl node */
951 #ifdef GATHER_STATISTICS
954 length = sizeof (struct tree_decl);
955 /* All decls in an inline function need to be saved. */
956 if (obstack != &permanent_obstack)
957 obstack = saveable_obstack;
959 /* PARM_DECLs go on the context of the parent. If this is a nested
960 function, then we must allocate the PARM_DECL on the parent's
961 obstack, so that they will live to the end of the parent's
962 closing brace. This is necessary in case we try to inline the
963 function into its parent.
965 PARM_DECLs of top-level functions do not have this problem. However,
966 we allocate them where we put the FUNCTION_DECL for languages such as
967 Ada that need to consult some flags in the PARM_DECLs of the function
970 See comment in restore_tree_status for why we can't put this
971 in function_obstack. */
972 if (code == PARM_DECL && obstack != &permanent_obstack)
975 if (current_function_decl)
976 context = decl_function_context (current_function_decl);
980 = find_function_data (context)->function_maybepermanent_obstack;
984 case 't': /* a type node */
985 #ifdef GATHER_STATISTICS
988 length = sizeof (struct tree_type);
989 /* All data types are put where we can preserve them if nec. */
990 if (obstack != &permanent_obstack)
991 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
994 case 'b': /* a lexical block */
995 #ifdef GATHER_STATISTICS
998 length = sizeof (struct tree_block);
999 /* All BLOCK nodes are put where we can preserve them if nec. */
1000 if (obstack != &permanent_obstack)
1001 obstack = saveable_obstack;
1004 case 's': /* an expression with side effects */
1005 #ifdef GATHER_STATISTICS
1009 case 'r': /* a reference */
1010 #ifdef GATHER_STATISTICS
1014 case 'e': /* an expression */
1015 case '<': /* a comparison expression */
1016 case '1': /* a unary arithmetic expression */
1017 case '2': /* a binary arithmetic expression */
1018 #ifdef GATHER_STATISTICS
1022 obstack = expression_obstack;
1023 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
1024 if (code == BIND_EXPR && obstack != &permanent_obstack)
1025 obstack = saveable_obstack;
1026 length = sizeof (struct tree_exp)
1027 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1030 case 'c': /* a constant */
1031 #ifdef GATHER_STATISTICS
1034 obstack = expression_obstack;
1036 /* We can't use tree_code_length for INTEGER_CST, since the number of
1037 words is machine-dependent due to varying length of HOST_WIDE_INT,
1038 which might be wider than a pointer (e.g., long long). Similarly
1039 for REAL_CST, since the number of words is machine-dependent due
1040 to varying size and alignment of `double'. */
1042 if (code == INTEGER_CST)
1043 length = sizeof (struct tree_int_cst);
1044 else if (code == REAL_CST)
1045 length = sizeof (struct tree_real_cst);
1047 length = sizeof (struct tree_common)
1048 + tree_code_length[(int) code] * sizeof (char *);
1051 case 'x': /* something random, like an identifier. */
1052 #ifdef GATHER_STATISTICS
1053 if (code == IDENTIFIER_NODE)
1055 else if (code == OP_IDENTIFIER)
1057 else if (code == TREE_VEC)
1062 length = sizeof (struct tree_common)
1063 + tree_code_length[(int) code] * sizeof (char *);
1064 /* Identifier nodes are always permanent since they are
1065 unique in a compiler run. */
1066 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1073 t = (tree) obstack_alloc (obstack, length);
1075 #ifdef GATHER_STATISTICS
1076 tree_node_counts[(int)kind]++;
1077 tree_node_sizes[(int)kind] += length;
1080 /* Clear a word at a time. */
1081 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1083 /* Clear any extra bytes. */
1084 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1085 ((char *) t)[i] = 0;
1087 TREE_SET_CODE (t, code);
1088 if (obstack == &permanent_obstack)
1089 TREE_PERMANENT (t) = 1;
1094 TREE_SIDE_EFFECTS (t) = 1;
1095 TREE_TYPE (t) = void_type_node;
1099 if (code != FUNCTION_DECL)
1101 DECL_IN_SYSTEM_HEADER (t)
1102 = in_system_header && (obstack == &permanent_obstack);
1103 DECL_SOURCE_LINE (t) = lineno;
1104 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
1105 DECL_UID (t) = next_decl_uid++;
1106 /* Note that we have not yet computed the alias set for this
1108 DECL_POINTER_ALIAS_SET (t) = -1;
1112 TYPE_UID (t) = next_type_uid++;
1114 TYPE_MAIN_VARIANT (t) = t;
1115 TYPE_OBSTACK (t) = obstack;
1116 TYPE_ATTRIBUTES (t) = NULL_TREE;
1117 #ifdef SET_DEFAULT_TYPE_ATTRIBUTES
1118 SET_DEFAULT_TYPE_ATTRIBUTES (t);
1120 /* Note that we have not yet computed the alias set for this
1122 TYPE_ALIAS_SET (t) = -1;
1126 TREE_CONSTANT (t) = 1;
1133 /* Return a new node with the same contents as NODE
1134 except that its TREE_CHAIN is zero and it has a fresh uid. */
1141 register enum tree_code code = TREE_CODE (node);
1142 register int length = 0;
1145 switch (TREE_CODE_CLASS (code))
1147 case 'd': /* A decl node */
1148 length = sizeof (struct tree_decl);
1151 case 't': /* a type node */
1152 length = sizeof (struct tree_type);
1155 case 'b': /* a lexical block node */
1156 length = sizeof (struct tree_block);
1159 case 'r': /* a reference */
1160 case 'e': /* an expression */
1161 case 's': /* an expression with side effects */
1162 case '<': /* a comparison expression */
1163 case '1': /* a unary arithmetic expression */
1164 case '2': /* a binary arithmetic expression */
1165 length = sizeof (struct tree_exp)
1166 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1169 case 'c': /* a constant */
1170 /* We can't use tree_code_length for INTEGER_CST, since the number of
1171 words is machine-dependent due to varying length of HOST_WIDE_INT,
1172 which might be wider than a pointer (e.g., long long). Similarly
1173 for REAL_CST, since the number of words is machine-dependent due
1174 to varying size and alignment of `double'. */
1175 if (code == INTEGER_CST)
1176 length = sizeof (struct tree_int_cst);
1177 else if (code == REAL_CST)
1178 length = sizeof (struct tree_real_cst);
1180 length = (sizeof (struct tree_common)
1181 + tree_code_length[(int) code] * sizeof (char *));
1184 case 'x': /* something random, like an identifier. */
1185 length = sizeof (struct tree_common)
1186 + tree_code_length[(int) code] * sizeof (char *);
1187 if (code == TREE_VEC)
1188 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1191 t = (tree) obstack_alloc (current_obstack, length);
1193 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1194 ((int *) t)[i] = ((int *) node)[i];
1195 /* Clear any extra bytes. */
1196 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1197 ((char *) t)[i] = ((char *) node)[i];
1199 /* EXPR_WITH_FILE_LOCATION must keep filename info stored in TREE_CHAIN */
1200 if (TREE_CODE (node) != EXPR_WITH_FILE_LOCATION)
1202 TREE_ASM_WRITTEN (t) = 0;
1204 if (TREE_CODE_CLASS (code) == 'd')
1205 DECL_UID (t) = next_decl_uid++;
1206 else if (TREE_CODE_CLASS (code) == 't')
1208 TYPE_UID (t) = next_type_uid++;
1209 TYPE_OBSTACK (t) = current_obstack;
1211 /* The following is so that the debug code for
1212 the copy is different from the original type.
1213 The two statements usually duplicate each other
1214 (because they clear fields of the same union),
1215 but the optimizer should catch that. */
1216 TYPE_SYMTAB_POINTER (t) = 0;
1217 TYPE_SYMTAB_ADDRESS (t) = 0;
1220 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1225 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1226 For example, this can copy a list made of TREE_LIST nodes. */
1233 register tree prev, next;
1238 head = prev = copy_node (list);
1239 next = TREE_CHAIN (list);
1242 TREE_CHAIN (prev) = copy_node (next);
1243 prev = TREE_CHAIN (prev);
1244 next = TREE_CHAIN (next);
1251 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1252 If an identifier with that name has previously been referred to,
1253 the same node is returned this time. */
1256 get_identifier (text)
1257 register char *text;
1262 register int len, hash_len;
1264 /* Compute length of text in len. */
1265 for (len = 0; text[len]; len++);
1267 /* Decide how much of that length to hash on */
1269 if (warn_id_clash && len > id_clash_len)
1270 hash_len = id_clash_len;
1272 /* Compute hash code */
1273 hi = hash_len * 613 + (unsigned) text[0];
1274 for (i = 1; i < hash_len; i += 2)
1275 hi = ((hi * 613) + (unsigned) (text[i]));
1277 hi &= (1 << HASHBITS) - 1;
1278 hi %= MAX_HASH_TABLE;
1280 /* Search table for identifier */
1281 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1282 if (IDENTIFIER_LENGTH (idp) == len
1283 && IDENTIFIER_POINTER (idp)[0] == text[0]
1284 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1285 return idp; /* <-- return if found */
1287 /* Not found; optionally warn about a similar identifier */
1288 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1289 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1290 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1292 warning ("`%s' and `%s' identical in first %d characters",
1293 IDENTIFIER_POINTER (idp), text, id_clash_len);
1297 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1298 abort (); /* set_identifier_size hasn't been called. */
1300 /* Not found, create one, add to chain */
1301 idp = make_node (IDENTIFIER_NODE);
1302 IDENTIFIER_LENGTH (idp) = len;
1303 #ifdef GATHER_STATISTICS
1304 id_string_size += len;
1307 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1309 TREE_CHAIN (idp) = hash_table[hi];
1310 hash_table[hi] = idp;
1311 return idp; /* <-- return if created */
1314 /* If an identifier with the name TEXT (a null-terminated string) has
1315 previously been referred to, return that node; otherwise return
1319 maybe_get_identifier (text)
1320 register char *text;
1325 register int len, hash_len;
1327 /* Compute length of text in len. */
1328 for (len = 0; text[len]; len++);
1330 /* Decide how much of that length to hash on */
1332 if (warn_id_clash && len > id_clash_len)
1333 hash_len = id_clash_len;
1335 /* Compute hash code */
1336 hi = hash_len * 613 + (unsigned) text[0];
1337 for (i = 1; i < hash_len; i += 2)
1338 hi = ((hi * 613) + (unsigned) (text[i]));
1340 hi &= (1 << HASHBITS) - 1;
1341 hi %= MAX_HASH_TABLE;
1343 /* Search table for identifier */
1344 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1345 if (IDENTIFIER_LENGTH (idp) == len
1346 && IDENTIFIER_POINTER (idp)[0] == text[0]
1347 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1348 return idp; /* <-- return if found */
1353 /* Enable warnings on similar identifiers (if requested).
1354 Done after the built-in identifiers are created. */
1357 start_identifier_warnings ()
1359 do_identifier_warnings = 1;
1362 /* Record the size of an identifier node for the language in use.
1363 SIZE is the total size in bytes.
1364 This is called by the language-specific files. This must be
1365 called before allocating any identifiers. */
1368 set_identifier_size (size)
1371 tree_code_length[(int) IDENTIFIER_NODE]
1372 = (size - sizeof (struct tree_common)) / sizeof (tree);
1375 /* Return a newly constructed INTEGER_CST node whose constant value
1376 is specified by the two ints LOW and HI.
1377 The TREE_TYPE is set to `int'.
1379 This function should be used via the `build_int_2' macro. */
1382 build_int_2_wide (low, hi)
1383 HOST_WIDE_INT low, hi;
1385 register tree t = make_node (INTEGER_CST);
1386 TREE_INT_CST_LOW (t) = low;
1387 TREE_INT_CST_HIGH (t) = hi;
1388 TREE_TYPE (t) = integer_type_node;
1392 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1395 build_real (type, d)
1402 /* Check for valid float value for this type on this target machine;
1403 if not, can print error message and store a valid value in D. */
1404 #ifdef CHECK_FLOAT_VALUE
1405 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1408 v = make_node (REAL_CST);
1409 TREE_TYPE (v) = type;
1410 TREE_REAL_CST (v) = d;
1411 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1415 /* Return a new REAL_CST node whose type is TYPE
1416 and whose value is the integer value of the INTEGER_CST node I. */
1418 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1421 real_value_from_int_cst (type, i)
1426 #ifdef REAL_ARITHMETIC
1427 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1428 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1431 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i),
1432 TREE_INT_CST_HIGH (i), TYPE_MODE (type));
1433 #else /* not REAL_ARITHMETIC */
1434 /* Some 386 compilers mishandle unsigned int to float conversions,
1435 so introduce a temporary variable E to avoid those bugs. */
1436 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1440 d = (double) (~ TREE_INT_CST_HIGH (i));
1441 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1442 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1444 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1452 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1453 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1454 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1456 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1459 #endif /* not REAL_ARITHMETIC */
1463 /* This function can't be implemented if we can't do arithmetic
1464 on the float representation. */
1467 build_real_from_int_cst (type, i)
1472 int overflow = TREE_OVERFLOW (i);
1474 jmp_buf float_error;
1476 v = make_node (REAL_CST);
1477 TREE_TYPE (v) = type;
1479 if (setjmp (float_error))
1486 set_float_handler (float_error);
1488 #ifdef REAL_ARITHMETIC
1489 d = real_value_from_int_cst (type, i);
1491 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type),
1492 real_value_from_int_cst (type, i));
1495 /* Check for valid float value for this type on this target machine. */
1498 set_float_handler (NULL_PTR);
1500 #ifdef CHECK_FLOAT_VALUE
1501 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1504 TREE_REAL_CST (v) = d;
1505 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1509 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1511 /* Return a newly constructed STRING_CST node whose value is
1512 the LEN characters at STR.
1513 The TREE_TYPE is not initialized. */
1516 build_string (len, str)
1520 /* Put the string in saveable_obstack since it will be placed in the RTL
1521 for an "asm" statement and will also be kept around a while if
1522 deferring constant output in varasm.c. */
1524 register tree s = make_node (STRING_CST);
1525 TREE_STRING_LENGTH (s) = len;
1526 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1530 /* Return a newly constructed COMPLEX_CST node whose value is
1531 specified by the real and imaginary parts REAL and IMAG.
1532 Both REAL and IMAG should be constant nodes. TYPE, if specified,
1533 will be the type of the COMPLEX_CST; otherwise a new type will be made. */
1536 build_complex (type, real, imag)
1540 register tree t = make_node (COMPLEX_CST);
1542 TREE_REALPART (t) = real;
1543 TREE_IMAGPART (t) = imag;
1544 TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1545 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1546 TREE_CONSTANT_OVERFLOW (t)
1547 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1551 /* Build a newly constructed TREE_VEC node of length LEN. */
1558 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1559 register struct obstack *obstack = current_obstack;
1562 #ifdef GATHER_STATISTICS
1563 tree_node_counts[(int)vec_kind]++;
1564 tree_node_sizes[(int)vec_kind] += length;
1567 t = (tree) obstack_alloc (obstack, length);
1569 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1572 TREE_SET_CODE (t, TREE_VEC);
1573 TREE_VEC_LENGTH (t) = len;
1574 if (obstack == &permanent_obstack)
1575 TREE_PERMANENT (t) = 1;
1580 /* Return 1 if EXPR is the integer constant zero or a complex constant
1584 integer_zerop (expr)
1589 return ((TREE_CODE (expr) == INTEGER_CST
1590 && ! TREE_CONSTANT_OVERFLOW (expr)
1591 && TREE_INT_CST_LOW (expr) == 0
1592 && TREE_INT_CST_HIGH (expr) == 0)
1593 || (TREE_CODE (expr) == COMPLEX_CST
1594 && integer_zerop (TREE_REALPART (expr))
1595 && integer_zerop (TREE_IMAGPART (expr))));
1598 /* Return 1 if EXPR is the integer constant one or the corresponding
1599 complex constant. */
1607 return ((TREE_CODE (expr) == INTEGER_CST
1608 && ! TREE_CONSTANT_OVERFLOW (expr)
1609 && TREE_INT_CST_LOW (expr) == 1
1610 && TREE_INT_CST_HIGH (expr) == 0)
1611 || (TREE_CODE (expr) == COMPLEX_CST
1612 && integer_onep (TREE_REALPART (expr))
1613 && integer_zerop (TREE_IMAGPART (expr))));
1616 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1617 it contains. Likewise for the corresponding complex constant. */
1620 integer_all_onesp (expr)
1628 if (TREE_CODE (expr) == COMPLEX_CST
1629 && integer_all_onesp (TREE_REALPART (expr))
1630 && integer_zerop (TREE_IMAGPART (expr)))
1633 else if (TREE_CODE (expr) != INTEGER_CST
1634 || TREE_CONSTANT_OVERFLOW (expr))
1637 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1639 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1641 /* Note that using TYPE_PRECISION here is wrong. We care about the
1642 actual bits, not the (arbitrary) range of the type. */
1643 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1644 if (prec >= HOST_BITS_PER_WIDE_INT)
1646 int high_value, shift_amount;
1648 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1650 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1651 /* Can not handle precisions greater than twice the host int size. */
1653 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1654 /* Shifting by the host word size is undefined according to the ANSI
1655 standard, so we must handle this as a special case. */
1658 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1660 return TREE_INT_CST_LOW (expr) == -1
1661 && TREE_INT_CST_HIGH (expr) == high_value;
1664 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1667 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1671 integer_pow2p (expr)
1675 HOST_WIDE_INT high, low;
1679 if (TREE_CODE (expr) == COMPLEX_CST
1680 && integer_pow2p (TREE_REALPART (expr))
1681 && integer_zerop (TREE_IMAGPART (expr)))
1684 if (TREE_CODE (expr) != INTEGER_CST || TREE_CONSTANT_OVERFLOW (expr))
1687 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1688 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1689 high = TREE_INT_CST_HIGH (expr);
1690 low = TREE_INT_CST_LOW (expr);
1692 /* First clear all bits that are beyond the type's precision in case
1693 we've been sign extended. */
1695 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1697 else if (prec > HOST_BITS_PER_WIDE_INT)
1698 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1702 if (prec < HOST_BITS_PER_WIDE_INT)
1703 low &= ~((HOST_WIDE_INT) (-1) << prec);
1706 if (high == 0 && low == 0)
1709 return ((high == 0 && (low & (low - 1)) == 0)
1710 || (low == 0 && (high & (high - 1)) == 0));
1713 /* Return the power of two represented by a tree node known to be a
1721 HOST_WIDE_INT high, low;
1725 if (TREE_CODE (expr) == COMPLEX_CST)
1726 return tree_log2 (TREE_REALPART (expr));
1728 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1729 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1731 high = TREE_INT_CST_HIGH (expr);
1732 low = TREE_INT_CST_LOW (expr);
1734 /* First clear all bits that are beyond the type's precision in case
1735 we've been sign extended. */
1737 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1739 else if (prec > HOST_BITS_PER_WIDE_INT)
1740 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1744 if (prec < HOST_BITS_PER_WIDE_INT)
1745 low &= ~((HOST_WIDE_INT) (-1) << prec);
1748 return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1749 : exact_log2 (low));
1752 /* Return 1 if EXPR is the real constant zero. */
1760 return ((TREE_CODE (expr) == REAL_CST
1761 && ! TREE_CONSTANT_OVERFLOW (expr)
1762 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1763 || (TREE_CODE (expr) == COMPLEX_CST
1764 && real_zerop (TREE_REALPART (expr))
1765 && real_zerop (TREE_IMAGPART (expr))));
1768 /* Return 1 if EXPR is the real constant one in real or complex form. */
1776 return ((TREE_CODE (expr) == REAL_CST
1777 && ! TREE_CONSTANT_OVERFLOW (expr)
1778 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1779 || (TREE_CODE (expr) == COMPLEX_CST
1780 && real_onep (TREE_REALPART (expr))
1781 && real_zerop (TREE_IMAGPART (expr))));
1784 /* Return 1 if EXPR is the real constant two. */
1792 return ((TREE_CODE (expr) == REAL_CST
1793 && ! TREE_CONSTANT_OVERFLOW (expr)
1794 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1795 || (TREE_CODE (expr) == COMPLEX_CST
1796 && real_twop (TREE_REALPART (expr))
1797 && real_zerop (TREE_IMAGPART (expr))));
1800 /* Nonzero if EXP is a constant or a cast of a constant. */
1803 really_constant_p (exp)
1806 /* This is not quite the same as STRIP_NOPS. It does more. */
1807 while (TREE_CODE (exp) == NOP_EXPR
1808 || TREE_CODE (exp) == CONVERT_EXPR
1809 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1810 exp = TREE_OPERAND (exp, 0);
1811 return TREE_CONSTANT (exp);
1814 /* Return first list element whose TREE_VALUE is ELEM.
1815 Return 0 if ELEM is not in LIST. */
1818 value_member (elem, list)
1823 if (elem == TREE_VALUE (list))
1825 list = TREE_CHAIN (list);
1830 /* Return first list element whose TREE_PURPOSE is ELEM.
1831 Return 0 if ELEM is not in LIST. */
1834 purpose_member (elem, list)
1839 if (elem == TREE_PURPOSE (list))
1841 list = TREE_CHAIN (list);
1846 /* Return first list element whose BINFO_TYPE is ELEM.
1847 Return 0 if ELEM is not in LIST. */
1850 binfo_member (elem, list)
1855 if (elem == BINFO_TYPE (list))
1857 list = TREE_CHAIN (list);
1862 /* Return nonzero if ELEM is part of the chain CHAIN. */
1865 chain_member (elem, chain)
1872 chain = TREE_CHAIN (chain);
1878 /* Return nonzero if ELEM is equal to TREE_VALUE (CHAIN) for any piece of
1880 /* ??? This function was added for machine specific attributes but is no
1881 longer used. It could be deleted if we could confirm all front ends
1885 chain_member_value (elem, chain)
1890 if (elem == TREE_VALUE (chain))
1892 chain = TREE_CHAIN (chain);
1898 /* Return nonzero if ELEM is equal to TREE_PURPOSE (CHAIN)
1899 for any piece of chain CHAIN. */
1900 /* ??? This function was added for machine specific attributes but is no
1901 longer used. It could be deleted if we could confirm all front ends
1905 chain_member_purpose (elem, chain)
1910 if (elem == TREE_PURPOSE (chain))
1912 chain = TREE_CHAIN (chain);
1918 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1919 We expect a null pointer to mark the end of the chain.
1920 This is the Lisp primitive `length'. */
1927 register int len = 0;
1929 for (tail = t; tail; tail = TREE_CHAIN (tail))
1935 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1936 by modifying the last node in chain 1 to point to chain 2.
1937 This is the Lisp primitive `nconc'. */
1949 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1951 TREE_CHAIN (t1) = op2;
1952 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1954 abort (); /* Circularity created. */
1960 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1964 register tree chain;
1968 while ((next = TREE_CHAIN (chain)))
1973 /* Reverse the order of elements in the chain T,
1974 and return the new head of the chain (old last element). */
1980 register tree prev = 0, decl, next;
1981 for (decl = t; decl; decl = next)
1983 next = TREE_CHAIN (decl);
1984 TREE_CHAIN (decl) = prev;
1990 /* Given a chain CHAIN of tree nodes,
1991 construct and return a list of those nodes. */
1997 tree result = NULL_TREE;
1998 tree in_tail = chain;
1999 tree out_tail = NULL_TREE;
2003 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
2005 TREE_CHAIN (out_tail) = next;
2009 in_tail = TREE_CHAIN (in_tail);
2015 /* Return a newly created TREE_LIST node whose
2016 purpose and value fields are PARM and VALUE. */
2019 build_tree_list (parm, value)
2022 register tree t = make_node (TREE_LIST);
2023 TREE_PURPOSE (t) = parm;
2024 TREE_VALUE (t) = value;
2028 /* Similar, but build on the temp_decl_obstack. */
2031 build_decl_list (parm, value)
2035 register struct obstack *ambient_obstack = current_obstack;
2036 current_obstack = &temp_decl_obstack;
2037 node = build_tree_list (parm, value);
2038 current_obstack = ambient_obstack;
2042 /* Similar, but build on the expression_obstack. */
2045 build_expr_list (parm, value)
2049 register struct obstack *ambient_obstack = current_obstack;
2050 current_obstack = expression_obstack;
2051 node = build_tree_list (parm, value);
2052 current_obstack = ambient_obstack;
2056 /* Return a newly created TREE_LIST node whose
2057 purpose and value fields are PARM and VALUE
2058 and whose TREE_CHAIN is CHAIN. */
2061 tree_cons (purpose, value, chain)
2062 tree purpose, value, chain;
2065 register tree node = make_node (TREE_LIST);
2068 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
2069 #ifdef GATHER_STATISTICS
2070 tree_node_counts[(int)x_kind]++;
2071 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
2074 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
2075 ((int *) node)[i] = 0;
2077 TREE_SET_CODE (node, TREE_LIST);
2078 if (current_obstack == &permanent_obstack)
2079 TREE_PERMANENT (node) = 1;
2082 TREE_CHAIN (node) = chain;
2083 TREE_PURPOSE (node) = purpose;
2084 TREE_VALUE (node) = value;
2088 /* Similar, but build on the temp_decl_obstack. */
2091 decl_tree_cons (purpose, value, chain)
2092 tree purpose, value, chain;
2095 register struct obstack *ambient_obstack = current_obstack;
2096 current_obstack = &temp_decl_obstack;
2097 node = tree_cons (purpose, value, chain);
2098 current_obstack = ambient_obstack;
2102 /* Similar, but build on the expression_obstack. */
2105 expr_tree_cons (purpose, value, chain)
2106 tree purpose, value, chain;
2109 register struct obstack *ambient_obstack = current_obstack;
2110 current_obstack = expression_obstack;
2111 node = tree_cons (purpose, value, chain);
2112 current_obstack = ambient_obstack;
2116 /* Same as `tree_cons' but make a permanent object. */
2119 perm_tree_cons (purpose, value, chain)
2120 tree purpose, value, chain;
2123 register struct obstack *ambient_obstack = current_obstack;
2124 current_obstack = &permanent_obstack;
2126 node = tree_cons (purpose, value, chain);
2127 current_obstack = ambient_obstack;
2131 /* Same as `tree_cons', but make this node temporary, regardless. */
2134 temp_tree_cons (purpose, value, chain)
2135 tree purpose, value, chain;
2138 register struct obstack *ambient_obstack = current_obstack;
2139 current_obstack = &temporary_obstack;
2141 node = tree_cons (purpose, value, chain);
2142 current_obstack = ambient_obstack;
2146 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
2149 saveable_tree_cons (purpose, value, chain)
2150 tree purpose, value, chain;
2153 register struct obstack *ambient_obstack = current_obstack;
2154 current_obstack = saveable_obstack;
2156 node = tree_cons (purpose, value, chain);
2157 current_obstack = ambient_obstack;
2161 /* Return the size nominally occupied by an object of type TYPE
2162 when it resides in memory. The value is measured in units of bytes,
2163 and its data type is that normally used for type sizes
2164 (which is the first type created by make_signed_type or
2165 make_unsigned_type). */
2168 size_in_bytes (type)
2173 if (type == error_mark_node)
2174 return integer_zero_node;
2176 type = TYPE_MAIN_VARIANT (type);
2177 t = TYPE_SIZE_UNIT (type);
2180 incomplete_type_error (NULL_TREE, type);
2181 return integer_zero_node;
2183 if (TREE_CODE (t) == INTEGER_CST)
2184 force_fit_type (t, 0);
2189 /* Return the size of TYPE (in bytes) as a wide integer
2190 or return -1 if the size can vary or is larger than an integer. */
2193 int_size_in_bytes (type)
2198 if (type == error_mark_node)
2201 type = TYPE_MAIN_VARIANT (type);
2202 t = TYPE_SIZE_UNIT (type);
2204 || TREE_CODE (t) != INTEGER_CST
2205 || TREE_INT_CST_HIGH (t) != 0)
2208 return TREE_INT_CST_LOW (t);
2211 /* Return, as a tree node, the number of elements for TYPE (which is an
2212 ARRAY_TYPE) minus one. This counts only elements of the top array.
2214 Don't let any SAVE_EXPRs escape; if we are called as part of a cleanup
2215 action, they would get unsaved. */
2218 array_type_nelts (type)
2221 tree index_type, min, max;
2223 /* If they did it with unspecified bounds, then we should have already
2224 given an error about it before we got here. */
2225 if (! TYPE_DOMAIN (type))
2226 return error_mark_node;
2228 index_type = TYPE_DOMAIN (type);
2229 min = TYPE_MIN_VALUE (index_type);
2230 max = TYPE_MAX_VALUE (index_type);
2232 if (! TREE_CONSTANT (min))
2235 if (TREE_CODE (min) == SAVE_EXPR)
2236 min = build (RTL_EXPR, TREE_TYPE (TYPE_MIN_VALUE (index_type)), 0,
2237 SAVE_EXPR_RTL (min));
2239 min = TYPE_MIN_VALUE (index_type);
2242 if (! TREE_CONSTANT (max))
2245 if (TREE_CODE (max) == SAVE_EXPR)
2246 max = build (RTL_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)), 0,
2247 SAVE_EXPR_RTL (max));
2249 max = TYPE_MAX_VALUE (index_type);
2252 return (integer_zerop (min)
2254 : fold (build (MINUS_EXPR, TREE_TYPE (max), max, min)));
2257 /* Return nonzero if arg is static -- a reference to an object in
2258 static storage. This is not the same as the C meaning of `static'. */
2264 switch (TREE_CODE (arg))
2267 /* Nested functions aren't static, since taking their address
2268 involves a trampoline. */
2269 return (decl_function_context (arg) == 0 || DECL_NO_STATIC_CHAIN (arg))
2270 && ! DECL_NON_ADDR_CONST_P (arg);
2273 return (TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2274 && ! DECL_NON_ADDR_CONST_P (arg);
2277 return TREE_STATIC (arg);
2282 /* If we are referencing a bitfield, we can't evaluate an
2283 ADDR_EXPR at compile time and so it isn't a constant. */
2285 return (! DECL_BIT_FIELD (TREE_OPERAND (arg, 1))
2286 && staticp (TREE_OPERAND (arg, 0)));
2292 /* This case is technically correct, but results in setting
2293 TREE_CONSTANT on ADDR_EXPRs that cannot be evaluated at
2296 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
2300 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2301 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2302 return staticp (TREE_OPERAND (arg, 0));
2309 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2310 Do this to any expression which may be used in more than one place,
2311 but must be evaluated only once.
2313 Normally, expand_expr would reevaluate the expression each time.
2314 Calling save_expr produces something that is evaluated and recorded
2315 the first time expand_expr is called on it. Subsequent calls to
2316 expand_expr just reuse the recorded value.
2318 The call to expand_expr that generates code that actually computes
2319 the value is the first call *at compile time*. Subsequent calls
2320 *at compile time* generate code to use the saved value.
2321 This produces correct result provided that *at run time* control
2322 always flows through the insns made by the first expand_expr
2323 before reaching the other places where the save_expr was evaluated.
2324 You, the caller of save_expr, must make sure this is so.
2326 Constants, and certain read-only nodes, are returned with no
2327 SAVE_EXPR because that is safe. Expressions containing placeholders
2328 are not touched; see tree.def for an explanation of what these
2335 register tree t = fold (expr);
2337 /* We don't care about whether this can be used as an lvalue in this
2339 while (TREE_CODE (t) == NON_LVALUE_EXPR)
2340 t = TREE_OPERAND (t, 0);
2342 /* If the tree evaluates to a constant, then we don't want to hide that
2343 fact (i.e. this allows further folding, and direct checks for constants).
2344 However, a read-only object that has side effects cannot be bypassed.
2345 Since it is no problem to reevaluate literals, we just return the
2348 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
2349 || TREE_CODE (t) == SAVE_EXPR || TREE_CODE (t) == ERROR_MARK)
2352 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2353 it means that the size or offset of some field of an object depends on
2354 the value within another field.
2356 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2357 and some variable since it would then need to be both evaluated once and
2358 evaluated more than once. Front-ends must assure this case cannot
2359 happen by surrounding any such subexpressions in their own SAVE_EXPR
2360 and forcing evaluation at the proper time. */
2361 if (contains_placeholder_p (t))
2364 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
2366 /* This expression might be placed ahead of a jump to ensure that the
2367 value was computed on both sides of the jump. So make sure it isn't
2368 eliminated as dead. */
2369 TREE_SIDE_EFFECTS (t) = 1;
2373 /* Arrange for an expression to be expanded multiple independent
2374 times. This is useful for cleanup actions, as the backend can
2375 expand them multiple times in different places. */
2383 /* If this is already protected, no sense in protecting it again. */
2384 if (TREE_CODE (expr) == UNSAVE_EXPR)
2387 t = build1 (UNSAVE_EXPR, TREE_TYPE (expr), expr);
2388 TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
2392 /* Returns the index of the first non-tree operand for CODE, or the number
2393 of operands if all are trees. */
2397 enum tree_code code;
2407 case WITH_CLEANUP_EXPR:
2408 /* Should be defined to be 2. */
2410 case METHOD_CALL_EXPR:
2413 return tree_code_length [(int) code];
2417 /* Modify a tree in place so that all the evaluate only once things
2418 are cleared out. Return the EXPR given. */
2421 unsave_expr_now (expr)
2424 enum tree_code code;
2428 if (expr == NULL_TREE)
2431 code = TREE_CODE (expr);
2432 first_rtl = first_rtl_op (code);
2436 SAVE_EXPR_RTL (expr) = 0;
2440 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 3);
2441 TREE_OPERAND (expr, 3) = NULL_TREE;
2445 /* I don't yet know how to emit a sequence multiple times. */
2446 if (RTL_EXPR_SEQUENCE (expr) != 0)
2451 CALL_EXPR_RTL (expr) = 0;
2452 if (TREE_OPERAND (expr, 1)
2453 && TREE_CODE (TREE_OPERAND (expr, 1)) == TREE_LIST)
2455 tree exp = TREE_OPERAND (expr, 1);
2458 unsave_expr_now (TREE_VALUE (exp));
2459 exp = TREE_CHAIN (exp);
2468 switch (TREE_CODE_CLASS (code))
2470 case 'c': /* a constant */
2471 case 't': /* a type node */
2472 case 'x': /* something random, like an identifier or an ERROR_MARK. */
2473 case 'd': /* A decl node */
2474 case 'b': /* A block node */
2477 case 'e': /* an expression */
2478 case 'r': /* a reference */
2479 case 's': /* an expression with side effects */
2480 case '<': /* a comparison expression */
2481 case '2': /* a binary arithmetic expression */
2482 case '1': /* a unary arithmetic expression */
2483 for (i = first_rtl - 1; i >= 0; i--)
2484 unsave_expr_now (TREE_OPERAND (expr, i));
2492 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2493 or offset that depends on a field within a record. */
2496 contains_placeholder_p (exp)
2499 register enum tree_code code = TREE_CODE (exp);
2502 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2503 in it since it is supplying a value for it. */
2504 if (code == WITH_RECORD_EXPR)
2506 else if (code == PLACEHOLDER_EXPR)
2509 switch (TREE_CODE_CLASS (code))
2512 /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2513 position computations since they will be converted into a
2514 WITH_RECORD_EXPR involving the reference, which will assume
2515 here will be valid. */
2516 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2519 if (code == TREE_LIST)
2520 return (contains_placeholder_p (TREE_VALUE (exp))
2521 || (TREE_CHAIN (exp) != 0
2522 && contains_placeholder_p (TREE_CHAIN (exp))));
2531 /* Ignoring the first operand isn't quite right, but works best. */
2532 return contains_placeholder_p (TREE_OPERAND (exp, 1));
2539 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2540 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2541 || contains_placeholder_p (TREE_OPERAND (exp, 2)));
2544 /* If we already know this doesn't have a placeholder, don't
2546 if (SAVE_EXPR_NOPLACEHOLDER (exp) || SAVE_EXPR_RTL (exp) != 0)
2549 SAVE_EXPR_NOPLACEHOLDER (exp) = 1;
2550 result = contains_placeholder_p (TREE_OPERAND (exp, 0));
2552 SAVE_EXPR_NOPLACEHOLDER (exp) = 0;
2557 return (TREE_OPERAND (exp, 1) != 0
2558 && contains_placeholder_p (TREE_OPERAND (exp, 1)));
2564 switch (tree_code_length[(int) code])
2567 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2569 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2570 || contains_placeholder_p (TREE_OPERAND (exp, 1)));
2581 /* Return 1 if EXP contains any expressions that produce cleanups for an
2582 outer scope to deal with. Used by fold. */
2590 if (! TREE_SIDE_EFFECTS (exp))
2593 switch (TREE_CODE (exp))
2596 case WITH_CLEANUP_EXPR:
2599 case CLEANUP_POINT_EXPR:
2603 for (exp = TREE_OPERAND (exp, 1); exp; exp = TREE_CHAIN (exp))
2605 cmp = has_cleanups (TREE_VALUE (exp));
2615 /* This general rule works for most tree codes. All exceptions should be
2616 handled above. If this is a language-specific tree code, we can't
2617 trust what might be in the operand, so say we don't know
2619 if ((int) TREE_CODE (exp) >= (int) LAST_AND_UNUSED_TREE_CODE)
2622 nops = first_rtl_op (TREE_CODE (exp));
2623 for (i = 0; i < nops; i++)
2624 if (TREE_OPERAND (exp, i) != 0)
2626 int type = TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, i)));
2627 if (type == 'e' || type == '<' || type == '1' || type == '2'
2628 || type == 'r' || type == 's')
2630 cmp = has_cleanups (TREE_OPERAND (exp, i));
2639 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2640 return a tree with all occurrences of references to F in a
2641 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2642 contains only arithmetic expressions or a CALL_EXPR with a
2643 PLACEHOLDER_EXPR occurring only in its arglist. */
2646 substitute_in_expr (exp, f, r)
2651 enum tree_code code = TREE_CODE (exp);
2656 switch (TREE_CODE_CLASS (code))
2663 if (code == PLACEHOLDER_EXPR)
2665 else if (code == TREE_LIST)
2667 op0 = (TREE_CHAIN (exp) == 0
2668 ? 0 : substitute_in_expr (TREE_CHAIN (exp), f, r));
2669 op1 = substitute_in_expr (TREE_VALUE (exp), f, r);
2670 if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2673 return tree_cons (TREE_PURPOSE (exp), op1, op0);
2682 switch (tree_code_length[(int) code])
2685 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2686 if (op0 == TREE_OPERAND (exp, 0))
2689 new = fold (build1 (code, TREE_TYPE (exp), op0));
2693 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2694 could, but we don't support it. */
2695 if (code == RTL_EXPR)
2697 else if (code == CONSTRUCTOR)
2700 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2701 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2702 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2705 new = fold (build (code, TREE_TYPE (exp), op0, op1));
2709 /* It cannot be that anything inside a SAVE_EXPR contains a
2710 PLACEHOLDER_EXPR. */
2711 if (code == SAVE_EXPR)
2714 else if (code == CALL_EXPR)
2716 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2717 if (op1 == TREE_OPERAND (exp, 1))
2720 return build (code, TREE_TYPE (exp),
2721 TREE_OPERAND (exp, 0), op1, NULL_TREE);
2724 else if (code != COND_EXPR)
2727 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2728 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2729 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2730 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2731 && op2 == TREE_OPERAND (exp, 2))
2734 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2747 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2748 and it is the right field, replace it with R. */
2749 for (inner = TREE_OPERAND (exp, 0);
2750 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2751 inner = TREE_OPERAND (inner, 0))
2753 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2754 && TREE_OPERAND (exp, 1) == f)
2757 /* If this expression hasn't been completed let, leave it
2759 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2760 && TREE_TYPE (inner) == 0)
2763 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2764 if (op0 == TREE_OPERAND (exp, 0))
2767 new = fold (build (code, TREE_TYPE (exp), op0,
2768 TREE_OPERAND (exp, 1)));
2772 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2773 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2774 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2775 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2776 && op2 == TREE_OPERAND (exp, 2))
2779 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2784 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2785 if (op0 == TREE_OPERAND (exp, 0))
2788 new = fold (build1 (code, TREE_TYPE (exp), op0));
2800 TREE_READONLY (new) = TREE_READONLY (exp);
2804 /* Stabilize a reference so that we can use it any number of times
2805 without causing its operands to be evaluated more than once.
2806 Returns the stabilized reference. This works by means of save_expr,
2807 so see the caveats in the comments about save_expr.
2809 Also allows conversion expressions whose operands are references.
2810 Any other kind of expression is returned unchanged. */
2813 stabilize_reference (ref)
2816 register tree result;
2817 register enum tree_code code = TREE_CODE (ref);
2824 /* No action is needed in this case. */
2830 case FIX_TRUNC_EXPR:
2831 case FIX_FLOOR_EXPR:
2832 case FIX_ROUND_EXPR:
2834 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2838 result = build_nt (INDIRECT_REF,
2839 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2843 result = build_nt (COMPONENT_REF,
2844 stabilize_reference (TREE_OPERAND (ref, 0)),
2845 TREE_OPERAND (ref, 1));
2849 result = build_nt (BIT_FIELD_REF,
2850 stabilize_reference (TREE_OPERAND (ref, 0)),
2851 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2852 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2856 result = build_nt (ARRAY_REF,
2857 stabilize_reference (TREE_OPERAND (ref, 0)),
2858 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2862 /* We cannot wrap the first expression in a SAVE_EXPR, as then
2863 it wouldn't be ignored. This matters when dealing with
2865 return stabilize_reference_1 (ref);
2868 result = build1 (INDIRECT_REF, TREE_TYPE (ref),
2869 save_expr (build1 (ADDR_EXPR,
2870 build_pointer_type (TREE_TYPE (ref)),
2875 /* If arg isn't a kind of lvalue we recognize, make no change.
2876 Caller should recognize the error for an invalid lvalue. */
2881 return error_mark_node;
2884 TREE_TYPE (result) = TREE_TYPE (ref);
2885 TREE_READONLY (result) = TREE_READONLY (ref);
2886 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2887 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2888 TREE_RAISES (result) = TREE_RAISES (ref);
2893 /* Subroutine of stabilize_reference; this is called for subtrees of
2894 references. Any expression with side-effects must be put in a SAVE_EXPR
2895 to ensure that it is only evaluated once.
2897 We don't put SAVE_EXPR nodes around everything, because assigning very
2898 simple expressions to temporaries causes us to miss good opportunities
2899 for optimizations. Among other things, the opportunity to fold in the
2900 addition of a constant into an addressing mode often gets lost, e.g.
2901 "y[i+1] += x;". In general, we take the approach that we should not make
2902 an assignment unless we are forced into it - i.e., that any non-side effect
2903 operator should be allowed, and that cse should take care of coalescing
2904 multiple utterances of the same expression should that prove fruitful. */
2907 stabilize_reference_1 (e)
2910 register tree result;
2911 register enum tree_code code = TREE_CODE (e);
2913 /* We cannot ignore const expressions because it might be a reference
2914 to a const array but whose index contains side-effects. But we can
2915 ignore things that are actual constant or that already have been
2916 handled by this function. */
2918 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2921 switch (TREE_CODE_CLASS (code))
2931 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2932 so that it will only be evaluated once. */
2933 /* The reference (r) and comparison (<) classes could be handled as
2934 below, but it is generally faster to only evaluate them once. */
2935 if (TREE_SIDE_EFFECTS (e))
2936 return save_expr (e);
2940 /* Constants need no processing. In fact, we should never reach
2945 /* Division is slow and tends to be compiled with jumps,
2946 especially the division by powers of 2 that is often
2947 found inside of an array reference. So do it just once. */
2948 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2949 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2950 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2951 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2952 return save_expr (e);
2953 /* Recursively stabilize each operand. */
2954 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2955 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2959 /* Recursively stabilize each operand. */
2960 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2967 TREE_TYPE (result) = TREE_TYPE (e);
2968 TREE_READONLY (result) = TREE_READONLY (e);
2969 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2970 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2971 TREE_RAISES (result) = TREE_RAISES (e);
2976 /* Low-level constructors for expressions. */
2978 /* Build an expression of code CODE, data type TYPE,
2979 and operands as specified by the arguments ARG1 and following arguments.
2980 Expressions and reference nodes can be created this way.
2981 Constants, decls, types and misc nodes cannot be. */
2984 build VPROTO((enum tree_code code, tree tt, ...))
2986 #ifndef ANSI_PROTOTYPES
2987 enum tree_code code;
2992 register int length;
2997 #ifndef ANSI_PROTOTYPES
2998 code = va_arg (p, enum tree_code);
2999 tt = va_arg (p, tree);
3002 t = make_node (code);
3003 length = tree_code_length[(int) code];
3008 /* This is equivalent to the loop below, but faster. */
3009 register tree arg0 = va_arg (p, tree);
3010 register tree arg1 = va_arg (p, tree);
3011 TREE_OPERAND (t, 0) = arg0;
3012 TREE_OPERAND (t, 1) = arg1;
3013 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
3014 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
3015 TREE_SIDE_EFFECTS (t) = 1;
3017 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
3019 else if (length == 1)
3021 register tree arg0 = va_arg (p, tree);
3023 /* Call build1 for this! */
3024 if (TREE_CODE_CLASS (code) != 's')
3026 TREE_OPERAND (t, 0) = arg0;
3027 if (arg0 && TREE_SIDE_EFFECTS (arg0))
3028 TREE_SIDE_EFFECTS (t) = 1;
3029 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
3033 for (i = 0; i < length; i++)
3035 register tree operand = va_arg (p, tree);
3036 TREE_OPERAND (t, i) = operand;
3039 if (TREE_SIDE_EFFECTS (operand))
3040 TREE_SIDE_EFFECTS (t) = 1;
3041 if (TREE_RAISES (operand))
3042 TREE_RAISES (t) = 1;
3050 /* Same as above, but only builds for unary operators.
3051 Saves lions share of calls to `build'; cuts down use
3052 of varargs, which is expensive for RISC machines. */
3055 build1 (code, type, node)
3056 enum tree_code code;
3060 register struct obstack *obstack = expression_obstack;
3061 register int i, length;
3062 #ifdef GATHER_STATISTICS
3063 register tree_node_kind kind;
3067 #ifdef GATHER_STATISTICS
3068 if (TREE_CODE_CLASS (code) == 'r')
3074 length = sizeof (struct tree_exp);
3076 t = (tree) obstack_alloc (obstack, length);
3078 #ifdef GATHER_STATISTICS
3079 tree_node_counts[(int)kind]++;
3080 tree_node_sizes[(int)kind] += length;
3083 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
3086 TREE_TYPE (t) = type;
3087 TREE_SET_CODE (t, code);
3089 if (obstack == &permanent_obstack)
3090 TREE_PERMANENT (t) = 1;
3092 TREE_OPERAND (t, 0) = node;
3095 if (TREE_SIDE_EFFECTS (node))
3096 TREE_SIDE_EFFECTS (t) = 1;
3097 if (TREE_RAISES (node))
3098 TREE_RAISES (t) = 1;
3104 /* Similar except don't specify the TREE_TYPE
3105 and leave the TREE_SIDE_EFFECTS as 0.
3106 It is permissible for arguments to be null,
3107 or even garbage if their values do not matter. */
3110 build_nt VPROTO((enum tree_code code, ...))
3112 #ifndef ANSI_PROTOTYPES
3113 enum tree_code code;
3117 register int length;
3122 #ifndef ANSI_PROTOTYPES
3123 code = va_arg (p, enum tree_code);
3126 t = make_node (code);
3127 length = tree_code_length[(int) code];
3129 for (i = 0; i < length; i++)
3130 TREE_OPERAND (t, i) = va_arg (p, tree);
3136 /* Similar to `build_nt', except we build
3137 on the temp_decl_obstack, regardless. */
3140 build_parse_node VPROTO((enum tree_code code, ...))
3142 #ifndef ANSI_PROTOTYPES
3143 enum tree_code code;
3145 register struct obstack *ambient_obstack = expression_obstack;
3148 register int length;
3153 #ifndef ANSI_PROTOTYPES
3154 code = va_arg (p, enum tree_code);
3157 expression_obstack = &temp_decl_obstack;
3159 t = make_node (code);
3160 length = tree_code_length[(int) code];
3162 for (i = 0; i < length; i++)
3163 TREE_OPERAND (t, i) = va_arg (p, tree);
3166 expression_obstack = ambient_obstack;
3171 /* Commented out because this wants to be done very
3172 differently. See cp-lex.c. */
3174 build_op_identifier (op1, op2)
3177 register tree t = make_node (OP_IDENTIFIER);
3178 TREE_PURPOSE (t) = op1;
3179 TREE_VALUE (t) = op2;
3184 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3185 We do NOT enter this node in any sort of symbol table.
3187 layout_decl is used to set up the decl's storage layout.
3188 Other slots are initialized to 0 or null pointers. */
3191 build_decl (code, name, type)
3192 enum tree_code code;
3197 t = make_node (code);
3199 /* if (type == error_mark_node)
3200 type = integer_type_node; */
3201 /* That is not done, deliberately, so that having error_mark_node
3202 as the type can suppress useless errors in the use of this variable. */
3204 DECL_NAME (t) = name;
3205 DECL_ASSEMBLER_NAME (t) = name;
3206 TREE_TYPE (t) = type;
3208 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3210 else if (code == FUNCTION_DECL)
3211 DECL_MODE (t) = FUNCTION_MODE;
3216 /* BLOCK nodes are used to represent the structure of binding contours
3217 and declarations, once those contours have been exited and their contents
3218 compiled. This information is used for outputting debugging info. */
3221 build_block (vars, tags, subblocks, supercontext, chain)
3222 tree vars, tags, subblocks, supercontext, chain;
3224 register tree block = make_node (BLOCK);
3225 BLOCK_VARS (block) = vars;
3226 BLOCK_TYPE_TAGS (block) = tags;
3227 BLOCK_SUBBLOCKS (block) = subblocks;
3228 BLOCK_SUPERCONTEXT (block) = supercontext;
3229 BLOCK_CHAIN (block) = chain;
3233 /* EXPR_WITH_FILE_LOCATION are used to keep track of the exact
3234 location where an expression or an identifier were encountered. It
3235 is necessary for languages where the frontend parser will handle
3236 recursively more than one file (Java is one of them). */
3239 build_expr_wfl (node, file, line, col)
3244 static char *last_file = 0;
3245 static tree last_filenode = NULL_TREE;
3246 register tree wfl = make_node (EXPR_WITH_FILE_LOCATION);
3248 EXPR_WFL_NODE (wfl) = node;
3249 EXPR_WFL_SET_LINECOL (wfl, line, col);
3250 if (file != last_file)
3253 last_filenode = file ? get_identifier (file) : NULL_TREE;
3255 EXPR_WFL_FILENAME_NODE (wfl) = last_filenode;
3258 TREE_SIDE_EFFECTS (wfl) = TREE_SIDE_EFFECTS (node);
3259 TREE_TYPE (wfl) = TREE_TYPE (node);
3264 /* Return a declaration like DDECL except that its DECL_MACHINE_ATTRIBUTE
3268 build_decl_attribute_variant (ddecl, attribute)
3269 tree ddecl, attribute;
3271 DECL_MACHINE_ATTRIBUTES (ddecl) = attribute;
3275 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3278 Record such modified types already made so we don't make duplicates. */
3281 build_type_attribute_variant (ttype, attribute)
3282 tree ttype, attribute;
3284 if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3286 register int hashcode;
3287 register struct obstack *ambient_obstack = current_obstack;
3290 if (ambient_obstack != &permanent_obstack)
3291 current_obstack = TYPE_OBSTACK (ttype);
3293 ntype = copy_node (ttype);
3294 current_obstack = ambient_obstack;
3296 TYPE_POINTER_TO (ntype) = 0;
3297 TYPE_REFERENCE_TO (ntype) = 0;
3298 TYPE_ATTRIBUTES (ntype) = attribute;
3300 /* Create a new main variant of TYPE. */
3301 TYPE_MAIN_VARIANT (ntype) = ntype;
3302 TYPE_NEXT_VARIANT (ntype) = 0;
3303 set_type_quals (ntype, TYPE_UNQUALIFIED);
3305 hashcode = TYPE_HASH (TREE_CODE (ntype))
3306 + TYPE_HASH (TREE_TYPE (ntype))
3307 + attribute_hash_list (attribute);
3309 switch (TREE_CODE (ntype))
3312 hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype));
3315 hashcode += TYPE_HASH (TYPE_DOMAIN (ntype));
3318 hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype));
3321 hashcode += TYPE_HASH (TYPE_PRECISION (ntype));
3327 ntype = type_hash_canon (hashcode, ntype);
3328 ttype = build_qualified_type (ntype, TYPE_QUALS (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)
3341 tree attr_args ATTRIBUTE_UNUSED;
3342 tree decl ATTRIBUTE_UNUSED;
3343 tree type ATTRIBUTE_UNUSED;
3346 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3347 tree decl_attr_list = decl != 0 ? DECL_MACHINE_ATTRIBUTES (decl) : 0;
3349 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3350 tree type_attr_list = TYPE_ATTRIBUTES (type);
3353 if (TREE_CODE (attr_name) != IDENTIFIER_NODE)
3356 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3358 && VALID_MACHINE_DECL_ATTRIBUTE (decl, decl_attr_list, attr_name, attr_args))
3360 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3363 if (attr != NULL_TREE)
3365 /* Override existing arguments. Declarations are unique so we can
3366 modify this in place. */
3367 TREE_VALUE (attr) = attr_args;
3371 decl_attr_list = tree_cons (attr_name, attr_args, decl_attr_list);
3372 decl = build_decl_attribute_variant (decl, decl_attr_list);
3379 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3381 /* Don't apply the attribute to both the decl and the type. */;
3382 else if (VALID_MACHINE_TYPE_ATTRIBUTE (type, type_attr_list, attr_name,
3385 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3388 if (attr != NULL_TREE)
3390 /* Override existing arguments.
3391 ??? This currently works since attribute arguments are not
3392 included in `attribute_hash_list'. Something more complicated
3393 may be needed in the future. */
3394 TREE_VALUE (attr) = attr_args;
3398 /* If this is part of a declaration, create a type variant,
3399 otherwise, this is part of a type definition, so add it
3400 to the base type. */
3401 type_attr_list = tree_cons (attr_name, attr_args, type_attr_list);
3403 type = build_type_attribute_variant (type, type_attr_list);
3405 TYPE_ATTRIBUTES (type) = type_attr_list;
3408 TREE_TYPE (decl) = type;
3412 /* Handle putting a type attribute on pointer-to-function-type by putting
3413 the attribute on the function type. */
3414 else if (POINTER_TYPE_P (type)
3415 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3416 && VALID_MACHINE_TYPE_ATTRIBUTE (TREE_TYPE (type), type_attr_list,
3417 attr_name, attr_args))
3419 tree inner_type = TREE_TYPE (type);
3420 tree inner_attr_list = TYPE_ATTRIBUTES (inner_type);
3421 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3424 if (attr != NULL_TREE)
3425 TREE_VALUE (attr) = attr_args;
3428 inner_attr_list = tree_cons (attr_name, attr_args, inner_attr_list);
3429 inner_type = build_type_attribute_variant (inner_type,
3434 TREE_TYPE (decl) = build_pointer_type (inner_type);
3443 /* Return non-zero if IDENT is a valid name for attribute ATTR,
3446 We try both `text' and `__text__', ATTR may be either one. */
3447 /* ??? It might be a reasonable simplification to require ATTR to be only
3448 `text'. One might then also require attribute lists to be stored in
3449 their canonicalized form. */
3452 is_attribute_p (attr, ident)
3456 int ident_len, attr_len;
3459 if (TREE_CODE (ident) != IDENTIFIER_NODE)
3462 if (strcmp (attr, IDENTIFIER_POINTER (ident)) == 0)
3465 p = IDENTIFIER_POINTER (ident);
3466 ident_len = strlen (p);
3467 attr_len = strlen (attr);
3469 /* If ATTR is `__text__', IDENT must be `text'; and vice versa. */
3473 || attr[attr_len - 2] != '_'
3474 || attr[attr_len - 1] != '_')
3476 if (ident_len == attr_len - 4
3477 && strncmp (attr + 2, p, attr_len - 4) == 0)
3482 if (ident_len == attr_len + 4
3483 && p[0] == '_' && p[1] == '_'
3484 && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3485 && strncmp (attr, p + 2, attr_len) == 0)
3492 /* Given an attribute name and a list of attributes, return a pointer to the
3493 attribute's list element if the attribute is part of the list, or NULL_TREE
3497 lookup_attribute (attr_name, list)
3503 for (l = list; l; l = TREE_CHAIN (l))
3505 if (TREE_CODE (TREE_PURPOSE (l)) != IDENTIFIER_NODE)
3507 if (is_attribute_p (attr_name, TREE_PURPOSE (l)))
3514 /* Return an attribute list that is the union of a1 and a2. */
3517 merge_attributes (a1, a2)
3518 register tree a1, a2;
3522 /* Either one unset? Take the set one. */
3524 if (! (attributes = a1))
3527 /* One that completely contains the other? Take it. */
3529 else if (a2 && ! attribute_list_contained (a1, a2))
3531 if (attribute_list_contained (a2, a1))
3535 /* Pick the longest list, and hang on the other list. */
3536 /* ??? For the moment we punt on the issue of attrs with args. */
3538 if (list_length (a1) < list_length (a2))
3539 attributes = a2, a2 = a1;
3541 for (; a2; a2 = TREE_CHAIN (a2))
3542 if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3543 attributes) == NULL_TREE)
3545 a1 = copy_node (a2);
3546 TREE_CHAIN (a1) = attributes;
3554 /* Given types T1 and T2, merge their attributes and return
3558 merge_machine_type_attributes (t1, t2)
3561 #ifdef MERGE_MACHINE_TYPE_ATTRIBUTES
3562 return MERGE_MACHINE_TYPE_ATTRIBUTES (t1, t2);
3564 return merge_attributes (TYPE_ATTRIBUTES (t1),
3565 TYPE_ATTRIBUTES (t2));
3569 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3573 merge_machine_decl_attributes (olddecl, newdecl)
3574 tree olddecl, newdecl;
3576 #ifdef MERGE_MACHINE_DECL_ATTRIBUTES
3577 return MERGE_MACHINE_DECL_ATTRIBUTES (olddecl, newdecl);
3579 return merge_attributes (DECL_MACHINE_ATTRIBUTES (olddecl),
3580 DECL_MACHINE_ATTRIBUTES (newdecl));
3584 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
3585 of the various TYPE_QUAL values. */
3588 set_type_quals (type, type_quals)
3592 TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
3593 TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
3594 TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
3597 /* Given a type node TYPE and a TYPE_QUALIFIER_SET, return a type for
3598 the same kind of data as TYPE describes. Variants point to the
3599 "main variant" (which has no qualifiers set) via TYPE_MAIN_VARIANT,
3600 and it points to a chain of other variants so that duplicate
3601 variants are never made. Only main variants should ever appear as
3602 types of expressions. */
3605 build_qualified_type (type, type_quals)
3611 /* Search the chain of variants to see if there is already one there just
3612 like the one we need to have. If so, use that existing one. We must
3613 preserve the TYPE_NAME, since there is code that depends on this. */
3615 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3616 if (TYPE_QUALS (t) == type_quals && TYPE_NAME (t) == TYPE_NAME (type))
3619 /* We need a new one. */
3620 t = build_type_copy (type);
3621 set_type_quals (t, type_quals);
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 set_type_quals (t, TYPE_QUALS (component_type));
4431 /* If we already have such a type, use the old one and free this one. */
4432 hashcode = TYPE_HASH (component_type);
4433 t = type_hash_canon (hashcode, t);
4435 if (TYPE_SIZE (t) == 0)
4441 /* Return OP, stripped of any conversions to wider types as much as is safe.
4442 Converting the value back to OP's type makes a value equivalent to OP.
4444 If FOR_TYPE is nonzero, we return a value which, if converted to
4445 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
4447 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
4448 narrowest type that can hold the value, even if they don't exactly fit.
4449 Otherwise, bit-field references are changed to a narrower type
4450 only if they can be fetched directly from memory in that type.
4452 OP must have integer, real or enumeral type. Pointers are not allowed!
4454 There are some cases where the obvious value we could return
4455 would regenerate to OP if converted to OP's type,
4456 but would not extend like OP to wider types.
4457 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
4458 For example, if OP is (unsigned short)(signed char)-1,
4459 we avoid returning (signed char)-1 if FOR_TYPE is int,
4460 even though extending that to an unsigned short would regenerate OP,
4461 since the result of extending (signed char)-1 to (int)
4462 is different from (int) OP. */
4465 get_unwidened (op, for_type)
4469 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
4470 register tree type = TREE_TYPE (op);
4471 register unsigned final_prec
4472 = TYPE_PRECISION (for_type != 0 ? for_type : type);
4474 = (for_type != 0 && for_type != type
4475 && final_prec > TYPE_PRECISION (type)
4476 && TREE_UNSIGNED (type));
4477 register tree win = op;
4479 while (TREE_CODE (op) == NOP_EXPR)
4481 register int bitschange
4482 = TYPE_PRECISION (TREE_TYPE (op))
4483 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4485 /* Truncations are many-one so cannot be removed.
4486 Unless we are later going to truncate down even farther. */
4488 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
4491 /* See what's inside this conversion. If we decide to strip it,
4493 op = TREE_OPERAND (op, 0);
4495 /* If we have not stripped any zero-extensions (uns is 0),
4496 we can strip any kind of extension.
4497 If we have previously stripped a zero-extension,
4498 only zero-extensions can safely be stripped.
4499 Any extension can be stripped if the bits it would produce
4500 are all going to be discarded later by truncating to FOR_TYPE. */
4504 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
4506 /* TREE_UNSIGNED says whether this is a zero-extension.
4507 Let's avoid computing it if it does not affect WIN
4508 and if UNS will not be needed again. */
4509 if ((uns || TREE_CODE (op) == NOP_EXPR)
4510 && TREE_UNSIGNED (TREE_TYPE (op)))
4518 if (TREE_CODE (op) == COMPONENT_REF
4519 /* Since type_for_size always gives an integer type. */
4520 && TREE_CODE (type) != REAL_TYPE
4521 /* Don't crash if field not laid out yet. */
4522 && DECL_SIZE (TREE_OPERAND (op, 1)) != 0)
4524 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4525 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
4527 /* We can get this structure field in the narrowest type it fits in.
4528 If FOR_TYPE is 0, do this only for a field that matches the
4529 narrower type exactly and is aligned for it
4530 The resulting extension to its nominal type (a fullword type)
4531 must fit the same conditions as for other extensions. */
4533 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4534 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
4535 && (! uns || final_prec <= innerprec
4536 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4539 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4540 TREE_OPERAND (op, 1));
4541 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4542 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4543 TREE_RAISES (win) = TREE_RAISES (op);
4549 /* Return OP or a simpler expression for a narrower value
4550 which can be sign-extended or zero-extended to give back OP.
4551 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
4552 or 0 if the value should be sign-extended. */
4555 get_narrower (op, unsignedp_ptr)
4559 register int uns = 0;
4561 register tree win = op;
4563 while (TREE_CODE (op) == NOP_EXPR)
4565 register int bitschange
4566 = TYPE_PRECISION (TREE_TYPE (op))
4567 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4569 /* Truncations are many-one so cannot be removed. */
4573 /* See what's inside this conversion. If we decide to strip it,
4575 op = TREE_OPERAND (op, 0);
4579 /* An extension: the outermost one can be stripped,
4580 but remember whether it is zero or sign extension. */
4582 uns = TREE_UNSIGNED (TREE_TYPE (op));
4583 /* Otherwise, if a sign extension has been stripped,
4584 only sign extensions can now be stripped;
4585 if a zero extension has been stripped, only zero-extensions. */
4586 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
4590 else /* bitschange == 0 */
4592 /* A change in nominal type can always be stripped, but we must
4593 preserve the unsignedness. */
4595 uns = TREE_UNSIGNED (TREE_TYPE (op));
4602 if (TREE_CODE (op) == COMPONENT_REF
4603 /* Since type_for_size always gives an integer type. */
4604 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
4606 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4607 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
4609 /* We can get this structure field in a narrower type that fits it,
4610 but the resulting extension to its nominal type (a fullword type)
4611 must satisfy the same conditions as for other extensions.
4613 Do this only for fields that are aligned (not bit-fields),
4614 because when bit-field insns will be used there is no
4615 advantage in doing this. */
4617 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4618 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
4619 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4623 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
4624 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4625 TREE_OPERAND (op, 1));
4626 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4627 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4628 TREE_RAISES (win) = TREE_RAISES (op);
4631 *unsignedp_ptr = uns;
4635 /* Nonzero if integer constant C has a value that is permissible
4636 for type TYPE (an INTEGER_TYPE). */
4639 int_fits_type_p (c, type)
4642 if (TREE_UNSIGNED (type))
4643 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4644 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
4645 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4646 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
4647 /* Negative ints never fit unsigned types. */
4648 && ! (TREE_INT_CST_HIGH (c) < 0
4649 && ! TREE_UNSIGNED (TREE_TYPE (c))));
4651 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4652 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
4653 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4654 && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
4655 /* Unsigned ints with top bit set never fit signed types. */
4656 && ! (TREE_INT_CST_HIGH (c) < 0
4657 && TREE_UNSIGNED (TREE_TYPE (c))));
4660 /* Return the innermost context enclosing DECL that is
4661 a FUNCTION_DECL, or zero if none. */
4664 decl_function_context (decl)
4669 if (TREE_CODE (decl) == ERROR_MARK)
4672 if (TREE_CODE (decl) == SAVE_EXPR)
4673 context = SAVE_EXPR_CONTEXT (decl);
4675 context = DECL_CONTEXT (decl);
4677 while (context && TREE_CODE (context) != FUNCTION_DECL)
4679 if (TREE_CODE_CLASS (TREE_CODE (context)) == 't')
4680 context = TYPE_CONTEXT (context);
4681 else if (TREE_CODE_CLASS (TREE_CODE (context)) == 'd')
4682 context = DECL_CONTEXT (context);
4683 else if (TREE_CODE (context) == BLOCK)
4684 context = BLOCK_SUPERCONTEXT (context);
4686 /* Unhandled CONTEXT !? */
4693 /* Return the innermost context enclosing DECL that is
4694 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
4695 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
4698 decl_type_context (decl)
4701 tree context = DECL_CONTEXT (decl);
4705 if (TREE_CODE (context) == RECORD_TYPE
4706 || TREE_CODE (context) == UNION_TYPE
4707 || TREE_CODE (context) == QUAL_UNION_TYPE)
4709 if (TREE_CODE (context) == TYPE_DECL
4710 || TREE_CODE (context) == FUNCTION_DECL)
4711 context = DECL_CONTEXT (context);
4712 else if (TREE_CODE (context) == BLOCK)
4713 context = BLOCK_SUPERCONTEXT (context);
4715 /* Unhandled CONTEXT!? */
4721 /* Print debugging information about the size of the
4722 toplev_inline_obstacks. */
4725 print_inline_obstack_statistics ()
4727 struct simple_obstack_stack *current = toplev_inline_obstacks;
4732 for (; current; current = current->next, ++n_obstacks)
4734 struct obstack *o = current->obstack;
4735 struct _obstack_chunk *chunk = o->chunk;
4737 n_alloc += o->next_free - chunk->contents;
4738 chunk = chunk->prev;
4740 for (; chunk; chunk = chunk->prev, ++n_chunks)
4741 n_alloc += chunk->limit - &chunk->contents[0];
4743 fprintf (stderr, "inline obstacks: %d obstacks, %d bytes, %d chunks\n",
4744 n_obstacks, n_alloc, n_chunks);
4747 /* Print debugging information about the obstack O, named STR. */
4750 print_obstack_statistics (str, o)
4754 struct _obstack_chunk *chunk = o->chunk;
4758 n_alloc += o->next_free - chunk->contents;
4759 chunk = chunk->prev;
4763 n_alloc += chunk->limit - &chunk->contents[0];
4764 chunk = chunk->prev;
4766 fprintf (stderr, "obstack %s: %u bytes, %d chunks\n",
4767 str, n_alloc, n_chunks);
4770 /* Print debugging information about tree nodes generated during the compile,
4771 and any language-specific information. */
4774 dump_tree_statistics ()
4776 #ifdef GATHER_STATISTICS
4778 int total_nodes, total_bytes;
4781 fprintf (stderr, "\n??? tree nodes created\n\n");
4782 #ifdef GATHER_STATISTICS
4783 fprintf (stderr, "Kind Nodes Bytes\n");
4784 fprintf (stderr, "-------------------------------------\n");
4785 total_nodes = total_bytes = 0;
4786 for (i = 0; i < (int) all_kinds; i++)
4788 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
4789 tree_node_counts[i], tree_node_sizes[i]);
4790 total_nodes += tree_node_counts[i];
4791 total_bytes += tree_node_sizes[i];
4793 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
4794 fprintf (stderr, "-------------------------------------\n");
4795 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
4796 fprintf (stderr, "-------------------------------------\n");
4798 fprintf (stderr, "(No per-node statistics)\n");
4800 print_obstack_statistics ("permanent_obstack", &permanent_obstack);
4801 print_obstack_statistics ("maybepermanent_obstack", &maybepermanent_obstack);
4802 print_obstack_statistics ("temporary_obstack", &temporary_obstack);
4803 print_obstack_statistics ("momentary_obstack", &momentary_obstack);
4804 print_obstack_statistics ("temp_decl_obstack", &temp_decl_obstack);
4805 print_inline_obstack_statistics ();
4806 print_lang_statistics ();
4809 #define FILE_FUNCTION_PREFIX_LEN 9
4811 #ifndef NO_DOLLAR_IN_LABEL
4812 #define FILE_FUNCTION_FORMAT "_GLOBAL_$%s$%s"
4813 #else /* NO_DOLLAR_IN_LABEL */
4814 #ifndef NO_DOT_IN_LABEL
4815 #define FILE_FUNCTION_FORMAT "_GLOBAL_.%s.%s"
4816 #else /* NO_DOT_IN_LABEL */
4817 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
4818 #endif /* NO_DOT_IN_LABEL */
4819 #endif /* NO_DOLLAR_IN_LABEL */
4821 extern char * first_global_object_name;
4822 extern char * weak_global_object_name;
4824 /* Appends 6 random characters to TEMPLATE to (hopefully) avoid name
4825 clashes in cases where we can't reliably choose a unique name.
4827 Derived from mkstemp.c in libiberty. */
4830 append_random_chars (template)
4833 static const char letters[]
4834 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
4835 static unsigned HOST_WIDE_INT value;
4836 unsigned HOST_WIDE_INT v;
4838 #ifdef HAVE_GETTIMEOFDAY
4842 template += strlen (template);
4844 #ifdef HAVE_GETTIMEOFDAY
4845 /* Get some more or less random data. */
4846 gettimeofday (&tv, NULL);
4847 value += ((unsigned HOST_WIDE_INT) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();
4854 /* Fill in the random bits. */
4855 template[0] = letters[v % 62];
4857 template[1] = letters[v % 62];
4859 template[2] = letters[v % 62];
4861 template[3] = letters[v % 62];
4863 template[4] = letters[v % 62];
4865 template[5] = letters[v % 62];
4870 /* Generate a name for a function unique to this translation unit.
4871 TYPE is some string to identify the purpose of this function to the
4872 linker or collect2. */
4875 get_file_function_name_long (type)
4881 if (first_global_object_name)
4882 p = first_global_object_name;
4885 /* We don't have anything that we know to be unique to this translation
4886 unit, so use what we do have and throw in some randomness. */
4888 char *name = weak_global_object_name;
4889 char *file = main_input_filename;
4894 file = input_filename;
4896 p = (char *) alloca (7 + strlen (name) + strlen (file));
4898 sprintf (p, "%s%s", name, file);
4899 append_random_chars (p);
4902 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)
4905 /* Set up the name of the file-level functions we may need. */
4906 /* Use a global object (which is already required to be unique over
4907 the program) rather than the file name (which imposes extra
4908 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
4909 sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
4911 /* Don't need to pull weird characters out of global names. */
4912 if (p != first_global_object_name)
4914 for (p = buf+11; *p; p++)
4915 if (! ((*p >= '0' && *p <= '9')
4916 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
4917 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
4921 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
4924 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
4927 || (*p >= 'A' && *p <= 'Z')
4928 || (*p >= 'a' && *p <= 'z')))
4932 return get_identifier (buf);
4935 /* If KIND=='I', return a suitable global initializer (constructor) name.
4936 If KIND=='D', return a suitable global clean-up (destructor) name. */
4939 get_file_function_name (kind)
4946 return get_file_function_name_long (p);
4950 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4951 The result is placed in BUFFER (which has length BIT_SIZE),
4952 with one bit in each char ('\000' or '\001').
4954 If the constructor is constant, NULL_TREE is returned.
4955 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4958 get_set_constructor_bits (init, buffer, bit_size)
4965 HOST_WIDE_INT domain_min
4966 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (init))));
4967 tree non_const_bits = NULL_TREE;
4968 for (i = 0; i < bit_size; i++)
4971 for (vals = TREE_OPERAND (init, 1);
4972 vals != NULL_TREE; vals = TREE_CHAIN (vals))
4974 if (TREE_CODE (TREE_VALUE (vals)) != INTEGER_CST
4975 || (TREE_PURPOSE (vals) != NULL_TREE
4976 && TREE_CODE (TREE_PURPOSE (vals)) != INTEGER_CST))
4978 = tree_cons (TREE_PURPOSE (vals), TREE_VALUE (vals), non_const_bits);
4979 else if (TREE_PURPOSE (vals) != NULL_TREE)
4981 /* Set a range of bits to ones. */
4982 HOST_WIDE_INT lo_index
4983 = TREE_INT_CST_LOW (TREE_PURPOSE (vals)) - domain_min;
4984 HOST_WIDE_INT hi_index
4985 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4986 if (lo_index < 0 || lo_index >= bit_size
4987 || hi_index < 0 || hi_index >= bit_size)
4989 for ( ; lo_index <= hi_index; lo_index++)
4990 buffer[lo_index] = 1;
4994 /* Set a single bit to one. */
4996 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4997 if (index < 0 || index >= bit_size)
4999 error ("invalid initializer for bit string");
5005 return non_const_bits;
5008 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
5009 The result is placed in BUFFER (which is an array of bytes).
5010 If the constructor is constant, NULL_TREE is returned.
5011 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
5014 get_set_constructor_bytes (init, buffer, wd_size)
5016 unsigned char *buffer;
5020 int set_word_size = BITS_PER_UNIT;
5021 int bit_size = wd_size * set_word_size;
5023 unsigned char *bytep = buffer;
5024 char *bit_buffer = (char *) alloca(bit_size);
5025 tree non_const_bits = get_set_constructor_bits (init, bit_buffer, bit_size);
5027 for (i = 0; i < wd_size; i++)
5030 for (i = 0; i < bit_size; i++)
5034 if (BYTES_BIG_ENDIAN)
5035 *bytep |= (1 << (set_word_size - 1 - bit_pos));
5037 *bytep |= 1 << bit_pos;
5040 if (bit_pos >= set_word_size)
5041 bit_pos = 0, bytep++;
5043 return non_const_bits;
5046 #ifdef ENABLE_CHECKING
5048 /* Complain if the tree code does not match the expected one.
5049 NODE is the tree node in question, CODE is the expected tree code,
5050 and FILE and LINE are the filename and line number, respectively,
5051 of the line on which the check was done. If NONFATAL is nonzero,
5052 don't abort if the reference is invalid; instead, return 0.
5053 If the reference is valid, return NODE. */
5056 tree_check (node, code, file, line, nofatal)
5058 enum tree_code code;
5063 if (TREE_CODE (node) == code)
5068 fatal ("%s:%d: Expect %s, have %s\n", file, line,
5069 tree_code_name[code], tree_code_name[TREE_CODE (node)]);
5072 /* Similar to above, except that we check for a class of tree
5073 code, given in CL. */
5076 tree_class_check (node, cl, file, line, nofatal)
5083 if (TREE_CODE_CLASS (TREE_CODE (node)) == cl)
5088 fatal ("%s:%d: Expect '%c', have '%s'\n", file, line,
5089 cl, tree_code_name[TREE_CODE (node)]);
5092 /* Likewise, but complain if the tree node is not an expression. */
5095 expr_check (node, ignored, file, line, nofatal)
5102 switch (TREE_CODE_CLASS (TREE_CODE (node)))
5116 fatal ("%s:%d: Expect expression, have '%s'\n", file, line,
5117 tree_code_name[TREE_CODE (node)]);
5124 /* Return the alias set for T, which may be either a type or an
5131 if (!flag_strict_aliasing || !lang_get_alias_set)
5132 /* If we're not doing any lanaguage-specific alias analysis, just
5133 assume everything aliases everything else. */
5136 return (*lang_get_alias_set) (t);
5139 /* Return a brand-new alias set. */
5144 static int last_alias_set;
5145 return ++last_alias_set;