1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 88, 92-98, 1999 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 const 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
324 *P. This function is called whenever we start compiling one
325 function in the midst of compiling another. For example, when
326 compiling a nested function, or, in C++, a template instantiation
327 that is required by the function we are currently compiling.
329 CONTEXT is the decl_function_context for the function we're about to
330 compile; if it isn't current_function_decl, we have to play some games. */
333 save_tree_status (p, context)
337 p->all_types_permanent = all_types_permanent;
338 p->momentary_stack = momentary_stack;
339 p->maybepermanent_firstobj = maybepermanent_firstobj;
340 p->temporary_firstobj = temporary_firstobj;
341 p->momentary_firstobj = momentary_firstobj;
342 p->momentary_function_firstobj = momentary_function_firstobj;
343 p->function_obstack = function_obstack;
344 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
345 p->current_obstack = current_obstack;
346 p->expression_obstack = expression_obstack;
347 p->saveable_obstack = saveable_obstack;
348 p->rtl_obstack = rtl_obstack;
349 p->inline_obstacks = inline_obstacks;
351 if (current_function_decl && context == current_function_decl)
352 /* Objects that need to be saved in this function can be in the nonsaved
353 obstack of the enclosing function since they can't possibly be needed
354 once it has returned. */
355 function_maybepermanent_obstack = function_obstack;
358 /* We're compiling a function which isn't nested in the current
359 function. We need to create a new maybepermanent_obstack for this
360 function, since it can't go onto any of the existing obstacks. */
361 struct simple_obstack_stack **head;
362 struct simple_obstack_stack *current;
364 if (context == NULL_TREE)
365 head = &toplev_inline_obstacks;
368 struct function *f = find_function_data (context);
369 head = &f->inline_obstacks;
372 if (context == NULL_TREE && extra_inline_obstacks)
374 current = extra_inline_obstacks;
375 extra_inline_obstacks = current->next;
379 current = ((struct simple_obstack_stack *)
380 xmalloc (sizeof (struct simple_obstack_stack)));
383 = (struct obstack *) xmalloc (sizeof (struct obstack));
384 gcc_obstack_init (current->obstack);
387 function_maybepermanent_obstack = current->obstack;
389 current->next = *head;
393 maybepermanent_firstobj
394 = (char *) obstack_finish (function_maybepermanent_obstack);
396 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
397 gcc_obstack_init (function_obstack);
399 current_obstack = &permanent_obstack;
400 expression_obstack = &permanent_obstack;
401 rtl_obstack = saveable_obstack = &permanent_obstack;
403 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
404 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
405 momentary_function_firstobj = momentary_firstobj;
408 /* Restore all variables describing the current status from the structure *P.
409 This is used after a nested function. */
412 restore_tree_status (p, context)
416 all_types_permanent = p->all_types_permanent;
417 momentary_stack = p->momentary_stack;
419 obstack_free (&momentary_obstack, momentary_function_firstobj);
421 /* Free saveable storage used by the function just compiled and not
424 CAUTION: This is in function_obstack of the containing function.
425 So we must be sure that we never allocate from that obstack during
426 the compilation of a nested function if we expect it to survive
427 past the nested function's end. */
428 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
430 /* If we were compiling a toplevel function, we can free this space now. */
431 if (context == NULL_TREE)
433 obstack_free (&temporary_obstack, temporary_firstobj);
434 obstack_free (&momentary_obstack, momentary_function_firstobj);
437 /* If we were compiling a toplevel function that we don't actually want
438 to save anything from, return the obstack to the pool. */
439 if (context == NULL_TREE
440 && obstack_empty_p (function_maybepermanent_obstack))
442 struct simple_obstack_stack *current, **p = &toplev_inline_obstacks;
446 while ((*p)->obstack != function_maybepermanent_obstack)
451 current->next = extra_inline_obstacks;
452 extra_inline_obstacks = current;
456 obstack_free (function_obstack, 0);
457 free (function_obstack);
459 temporary_firstobj = p->temporary_firstobj;
460 momentary_firstobj = p->momentary_firstobj;
461 momentary_function_firstobj = p->momentary_function_firstobj;
462 maybepermanent_firstobj = p->maybepermanent_firstobj;
463 function_obstack = p->function_obstack;
464 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
465 current_obstack = p->current_obstack;
466 expression_obstack = p->expression_obstack;
467 saveable_obstack = p->saveable_obstack;
468 rtl_obstack = p->rtl_obstack;
469 inline_obstacks = p->inline_obstacks;
472 /* Start allocating on the temporary (per function) obstack.
473 This is done in start_function before parsing the function body,
474 and before each initialization at top level, and to go back
475 to temporary allocation after doing permanent_allocation. */
478 temporary_allocation ()
480 /* Note that function_obstack at top level points to temporary_obstack.
481 But within a nested function context, it is a separate obstack. */
482 current_obstack = function_obstack;
483 expression_obstack = function_obstack;
484 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
489 /* Start allocating on the permanent obstack but don't
490 free the temporary data. After calling this, call
491 `permanent_allocation' to fully resume permanent allocation status. */
494 end_temporary_allocation ()
496 current_obstack = &permanent_obstack;
497 expression_obstack = &permanent_obstack;
498 rtl_obstack = saveable_obstack = &permanent_obstack;
501 /* Resume allocating on the temporary obstack, undoing
502 effects of `end_temporary_allocation'. */
505 resume_temporary_allocation ()
507 current_obstack = function_obstack;
508 expression_obstack = function_obstack;
509 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
512 /* While doing temporary allocation, switch to allocating in such a
513 way as to save all nodes if the function is inlined. Call
514 resume_temporary_allocation to go back to ordinary temporary
518 saveable_allocation ()
520 /* Note that function_obstack at top level points to temporary_obstack.
521 But within a nested function context, it is a separate obstack. */
522 expression_obstack = current_obstack = saveable_obstack;
525 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
526 recording the previously current obstacks on a stack.
527 This does not free any storage in any obstack. */
530 push_obstacks (current, saveable)
531 struct obstack *current, *saveable;
533 struct obstack_stack *p
534 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
535 (sizeof (struct obstack_stack)));
537 p->current = current_obstack;
538 p->saveable = saveable_obstack;
539 p->expression = expression_obstack;
540 p->rtl = rtl_obstack;
541 p->next = obstack_stack;
544 current_obstack = current;
545 expression_obstack = current;
546 rtl_obstack = saveable_obstack = saveable;
549 /* Save the current set of obstacks, but don't change them. */
552 push_obstacks_nochange ()
554 struct obstack_stack *p
555 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
556 (sizeof (struct obstack_stack)));
558 p->current = current_obstack;
559 p->saveable = saveable_obstack;
560 p->expression = expression_obstack;
561 p->rtl = rtl_obstack;
562 p->next = obstack_stack;
566 /* Pop the obstack selection stack. */
571 struct obstack_stack *p = obstack_stack;
572 obstack_stack = p->next;
574 current_obstack = p->current;
575 saveable_obstack = p->saveable;
576 expression_obstack = p->expression;
577 rtl_obstack = p->rtl;
579 obstack_free (&obstack_stack_obstack, p);
582 /* Nonzero if temporary allocation is currently in effect.
583 Zero if currently doing permanent allocation. */
586 allocation_temporary_p ()
588 return current_obstack != &permanent_obstack;
591 /* Go back to allocating on the permanent obstack
592 and free everything in the temporary obstack.
594 FUNCTION_END is true only if we have just finished compiling a function.
595 In that case, we also free preserved initial values on the momentary
599 permanent_allocation (function_end)
602 /* Free up previous temporary obstack data */
603 obstack_free (&temporary_obstack, temporary_firstobj);
606 obstack_free (&momentary_obstack, momentary_function_firstobj);
607 momentary_firstobj = momentary_function_firstobj;
610 obstack_free (&momentary_obstack, momentary_firstobj);
611 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
612 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
614 /* Free up the maybepermanent_obstacks for any of our nested functions
615 which were compiled at a lower level. */
616 while (inline_obstacks)
618 struct simple_obstack_stack *current = inline_obstacks;
619 inline_obstacks = current->next;
620 obstack_free (current->obstack, 0);
621 free (current->obstack);
625 current_obstack = &permanent_obstack;
626 expression_obstack = &permanent_obstack;
627 rtl_obstack = saveable_obstack = &permanent_obstack;
630 /* Save permanently everything on the maybepermanent_obstack. */
635 maybepermanent_firstobj
636 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
640 preserve_initializer ()
642 struct momentary_level *tem;
646 = (char *) obstack_alloc (&temporary_obstack, 0);
647 maybepermanent_firstobj
648 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
650 old_momentary = momentary_firstobj;
652 = (char *) obstack_alloc (&momentary_obstack, 0);
653 if (momentary_firstobj != old_momentary)
654 for (tem = momentary_stack; tem; tem = tem->prev)
655 tem->base = momentary_firstobj;
658 /* Start allocating new rtl in current_obstack.
659 Use resume_temporary_allocation
660 to go back to allocating rtl in saveable_obstack. */
663 rtl_in_current_obstack ()
665 rtl_obstack = current_obstack;
668 /* Start allocating rtl from saveable_obstack. Intended to be used after
669 a call to push_obstacks_nochange. */
672 rtl_in_saveable_obstack ()
674 rtl_obstack = saveable_obstack;
677 /* Allocate SIZE bytes in the current obstack
678 and return a pointer to them.
679 In practice the current obstack is always the temporary one. */
685 return (char *) obstack_alloc (current_obstack, size);
688 /* Free the object PTR in the current obstack
689 as well as everything allocated since PTR.
690 In practice the current obstack is always the temporary one. */
696 obstack_free (current_obstack, ptr);
699 /* Allocate SIZE bytes in the permanent obstack
700 and return a pointer to them. */
706 return (char *) obstack_alloc (&permanent_obstack, size);
709 /* Allocate NELEM items of SIZE bytes in the permanent obstack
710 and return a pointer to them. The storage is cleared before
711 returning the value. */
714 perm_calloc (nelem, size)
718 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
719 bzero (rval, nelem * size);
723 /* Allocate SIZE bytes in the saveable obstack
724 and return a pointer to them. */
730 return (char *) obstack_alloc (saveable_obstack, size);
733 /* Allocate SIZE bytes in the expression obstack
734 and return a pointer to them. */
740 return (char *) obstack_alloc (expression_obstack, size);
743 /* Print out which obstack an object is in. */
746 print_obstack_name (object, file, prefix)
751 struct obstack *obstack = NULL;
752 const char *obstack_name = NULL;
755 for (p = outer_function_chain; p; p = p->next)
757 if (_obstack_allocated_p (p->function_obstack, object))
759 obstack = p->function_obstack;
760 obstack_name = "containing function obstack";
762 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
764 obstack = p->function_maybepermanent_obstack;
765 obstack_name = "containing function maybepermanent obstack";
769 if (_obstack_allocated_p (&obstack_stack_obstack, object))
771 obstack = &obstack_stack_obstack;
772 obstack_name = "obstack_stack_obstack";
774 else if (_obstack_allocated_p (function_obstack, object))
776 obstack = function_obstack;
777 obstack_name = "function obstack";
779 else if (_obstack_allocated_p (&permanent_obstack, object))
781 obstack = &permanent_obstack;
782 obstack_name = "permanent_obstack";
784 else if (_obstack_allocated_p (&momentary_obstack, object))
786 obstack = &momentary_obstack;
787 obstack_name = "momentary_obstack";
789 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
791 obstack = function_maybepermanent_obstack;
792 obstack_name = "function maybepermanent obstack";
794 else if (_obstack_allocated_p (&temp_decl_obstack, object))
796 obstack = &temp_decl_obstack;
797 obstack_name = "temp_decl_obstack";
800 /* Check to see if the object is in the free area of the obstack. */
803 if (object >= obstack->next_free
804 && object < obstack->chunk_limit)
805 fprintf (file, "%s in free portion of obstack %s",
806 prefix, obstack_name);
808 fprintf (file, "%s allocated from %s", prefix, obstack_name);
811 fprintf (file, "%s not allocated from any obstack", prefix);
815 debug_obstack (object)
818 print_obstack_name (object, stderr, "object");
819 fprintf (stderr, ".\n");
822 /* Return 1 if OBJ is in the permanent obstack.
823 This is slow, and should be used only for debugging.
824 Use TREE_PERMANENT for other purposes. */
827 object_permanent_p (obj)
830 return _obstack_allocated_p (&permanent_obstack, obj);
833 /* Start a level of momentary allocation.
834 In C, each compound statement has its own level
835 and that level is freed at the end of each statement.
836 All expression nodes are allocated in the momentary allocation level. */
841 struct momentary_level *tem
842 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
843 sizeof (struct momentary_level));
844 tem->prev = momentary_stack;
845 tem->base = (char *) obstack_base (&momentary_obstack);
846 tem->obstack = expression_obstack;
847 momentary_stack = tem;
848 expression_obstack = &momentary_obstack;
851 /* Set things up so the next clear_momentary will only clear memory
852 past our present position in momentary_obstack. */
855 preserve_momentary ()
857 momentary_stack->base = (char *) obstack_base (&momentary_obstack);
860 /* Free all the storage in the current momentary-allocation level.
861 In C, this happens at the end of each statement. */
866 obstack_free (&momentary_obstack, momentary_stack->base);
869 /* Discard a level of momentary allocation.
870 In C, this happens at the end of each compound statement.
871 Restore the status of expression node allocation
872 that was in effect before this level was created. */
877 struct momentary_level *tem = momentary_stack;
878 momentary_stack = tem->prev;
879 expression_obstack = tem->obstack;
880 /* We can't free TEM from the momentary_obstack, because there might
881 be objects above it which have been saved. We can free back to the
882 stack of the level we are popping off though. */
883 obstack_free (&momentary_obstack, tem->base);
886 /* Pop back to the previous level of momentary allocation,
887 but don't free any momentary data just yet. */
890 pop_momentary_nofree ()
892 struct momentary_level *tem = momentary_stack;
893 momentary_stack = tem->prev;
894 expression_obstack = tem->obstack;
897 /* Call when starting to parse a declaration:
898 make expressions in the declaration last the length of the function.
899 Returns an argument that should be passed to resume_momentary later. */
904 register int tem = expression_obstack == &momentary_obstack;
905 expression_obstack = saveable_obstack;
909 /* Call when finished parsing a declaration:
910 restore the treatment of node-allocation that was
911 in effect before the suspension.
912 YES should be the value previously returned by suspend_momentary. */
915 resume_momentary (yes)
919 expression_obstack = &momentary_obstack;
922 /* Init the tables indexed by tree code.
923 Note that languages can add to these tables to define their own codes. */
931 /* Return a newly allocated node of code CODE.
932 Initialize the node's unique id and its TREE_PERMANENT flag.
933 For decl and type nodes, some other fields are initialized.
934 The rest of the node is initialized to zero.
936 Achoo! I got a code in the node. */
943 register int type = TREE_CODE_CLASS (code);
944 register int length = 0;
945 register struct obstack *obstack = current_obstack;
946 #ifdef GATHER_STATISTICS
947 register tree_node_kind kind;
952 case 'd': /* A decl node */
953 #ifdef GATHER_STATISTICS
956 length = sizeof (struct tree_decl);
957 /* All decls in an inline function need to be saved. */
958 if (obstack != &permanent_obstack)
959 obstack = saveable_obstack;
961 /* PARM_DECLs go on the context of the parent. If this is a nested
962 function, then we must allocate the PARM_DECL on the parent's
963 obstack, so that they will live to the end of the parent's
964 closing brace. This is necessary in case we try to inline the
965 function into its parent.
967 PARM_DECLs of top-level functions do not have this problem. However,
968 we allocate them where we put the FUNCTION_DECL for languages such as
969 Ada that need to consult some flags in the PARM_DECLs of the function
972 See comment in restore_tree_status for why we can't put this
973 in function_obstack. */
974 if (code == PARM_DECL && obstack != &permanent_obstack)
977 if (current_function_decl)
978 context = decl_function_context (current_function_decl);
982 = find_function_data (context)->function_maybepermanent_obstack;
986 case 't': /* a type node */
987 #ifdef GATHER_STATISTICS
990 length = sizeof (struct tree_type);
991 /* All data types are put where we can preserve them if nec. */
992 if (obstack != &permanent_obstack)
993 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
996 case 'b': /* a lexical block */
997 #ifdef GATHER_STATISTICS
1000 length = sizeof (struct tree_block);
1001 /* All BLOCK nodes are put where we can preserve them if nec. */
1002 if (obstack != &permanent_obstack)
1003 obstack = saveable_obstack;
1006 case 's': /* an expression with side effects */
1007 #ifdef GATHER_STATISTICS
1011 case 'r': /* a reference */
1012 #ifdef GATHER_STATISTICS
1016 case 'e': /* an expression */
1017 case '<': /* a comparison expression */
1018 case '1': /* a unary arithmetic expression */
1019 case '2': /* a binary arithmetic expression */
1020 #ifdef GATHER_STATISTICS
1024 obstack = expression_obstack;
1025 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
1026 if (code == BIND_EXPR && obstack != &permanent_obstack)
1027 obstack = saveable_obstack;
1028 length = sizeof (struct tree_exp)
1029 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1032 case 'c': /* a constant */
1033 #ifdef GATHER_STATISTICS
1036 obstack = expression_obstack;
1038 /* We can't use tree_code_length for INTEGER_CST, since the number of
1039 words is machine-dependent due to varying length of HOST_WIDE_INT,
1040 which might be wider than a pointer (e.g., long long). Similarly
1041 for REAL_CST, since the number of words is machine-dependent due
1042 to varying size and alignment of `double'. */
1044 if (code == INTEGER_CST)
1045 length = sizeof (struct tree_int_cst);
1046 else if (code == REAL_CST)
1047 length = sizeof (struct tree_real_cst);
1049 length = sizeof (struct tree_common)
1050 + tree_code_length[(int) code] * sizeof (char *);
1053 case 'x': /* something random, like an identifier. */
1054 #ifdef GATHER_STATISTICS
1055 if (code == IDENTIFIER_NODE)
1057 else if (code == OP_IDENTIFIER)
1059 else if (code == TREE_VEC)
1064 length = sizeof (struct tree_common)
1065 + tree_code_length[(int) code] * sizeof (char *);
1066 /* Identifier nodes are always permanent since they are
1067 unique in a compiler run. */
1068 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1075 t = (tree) obstack_alloc (obstack, length);
1076 bzero ((PTR) t, length);
1078 #ifdef GATHER_STATISTICS
1079 tree_node_counts[(int)kind]++;
1080 tree_node_sizes[(int)kind] += length;
1083 TREE_SET_CODE (t, code);
1084 if (obstack == &permanent_obstack)
1085 TREE_PERMANENT (t) = 1;
1090 TREE_SIDE_EFFECTS (t) = 1;
1091 TREE_TYPE (t) = void_type_node;
1095 if (code != FUNCTION_DECL)
1097 DECL_IN_SYSTEM_HEADER (t)
1098 = in_system_header && (obstack == &permanent_obstack);
1099 DECL_SOURCE_LINE (t) = lineno;
1100 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
1101 DECL_UID (t) = next_decl_uid++;
1102 /* Note that we have not yet computed the alias set for this
1104 DECL_POINTER_ALIAS_SET (t) = -1;
1108 TYPE_UID (t) = next_type_uid++;
1110 TYPE_MAIN_VARIANT (t) = t;
1111 TYPE_OBSTACK (t) = obstack;
1112 TYPE_ATTRIBUTES (t) = NULL_TREE;
1113 #ifdef SET_DEFAULT_TYPE_ATTRIBUTES
1114 SET_DEFAULT_TYPE_ATTRIBUTES (t);
1116 /* Note that we have not yet computed the alias set for this
1118 TYPE_ALIAS_SET (t) = -1;
1122 TREE_CONSTANT (t) = 1;
1129 /* Return a new node with the same contents as NODE
1130 except that its TREE_CHAIN is zero and it has a fresh uid. */
1137 register enum tree_code code = TREE_CODE (node);
1138 register int length = 0;
1140 switch (TREE_CODE_CLASS (code))
1142 case 'd': /* A decl node */
1143 length = sizeof (struct tree_decl);
1146 case 't': /* a type node */
1147 length = sizeof (struct tree_type);
1150 case 'b': /* a lexical block node */
1151 length = sizeof (struct tree_block);
1154 case 'r': /* a reference */
1155 case 'e': /* an expression */
1156 case 's': /* an expression with side effects */
1157 case '<': /* a comparison expression */
1158 case '1': /* a unary arithmetic expression */
1159 case '2': /* a binary arithmetic expression */
1160 length = sizeof (struct tree_exp)
1161 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1164 case 'c': /* a constant */
1165 /* We can't use tree_code_length for INTEGER_CST, since the number of
1166 words is machine-dependent due to varying length of HOST_WIDE_INT,
1167 which might be wider than a pointer (e.g., long long). Similarly
1168 for REAL_CST, since the number of words is machine-dependent due
1169 to varying size and alignment of `double'. */
1170 if (code == INTEGER_CST)
1171 length = sizeof (struct tree_int_cst);
1172 else if (code == REAL_CST)
1173 length = sizeof (struct tree_real_cst);
1175 length = (sizeof (struct tree_common)
1176 + tree_code_length[(int) code] * sizeof (char *));
1179 case 'x': /* something random, like an identifier. */
1180 length = sizeof (struct tree_common)
1181 + tree_code_length[(int) code] * sizeof (char *);
1182 if (code == TREE_VEC)
1183 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1186 t = (tree) obstack_alloc (current_obstack, length);
1187 memcpy (t, node, length);
1189 /* EXPR_WITH_FILE_LOCATION must keep filename info stored in TREE_CHAIN */
1190 if (TREE_CODE (node) != EXPR_WITH_FILE_LOCATION)
1192 TREE_ASM_WRITTEN (t) = 0;
1194 if (TREE_CODE_CLASS (code) == 'd')
1195 DECL_UID (t) = next_decl_uid++;
1196 else if (TREE_CODE_CLASS (code) == 't')
1198 TYPE_UID (t) = next_type_uid++;
1199 TYPE_OBSTACK (t) = current_obstack;
1201 /* The following is so that the debug code for
1202 the copy is different from the original type.
1203 The two statements usually duplicate each other
1204 (because they clear fields of the same union),
1205 but the optimizer should catch that. */
1206 TYPE_SYMTAB_POINTER (t) = 0;
1207 TYPE_SYMTAB_ADDRESS (t) = 0;
1210 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1215 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1216 For example, this can copy a list made of TREE_LIST nodes. */
1223 register tree prev, next;
1228 head = prev = copy_node (list);
1229 next = TREE_CHAIN (list);
1232 TREE_CHAIN (prev) = copy_node (next);
1233 prev = TREE_CHAIN (prev);
1234 next = TREE_CHAIN (next);
1241 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1242 If an identifier with that name has previously been referred to,
1243 the same node is returned this time. */
1246 get_identifier (text)
1247 register const char *text;
1252 register int len, hash_len;
1254 /* Compute length of text in len. */
1255 len = strlen (text);
1257 /* Decide how much of that length to hash on */
1259 if (warn_id_clash && (unsigned)len > id_clash_len)
1260 hash_len = id_clash_len;
1262 /* Compute hash code */
1263 hi = hash_len * 613 + (unsigned) text[0];
1264 for (i = 1; i < hash_len; i += 2)
1265 hi = ((hi * 613) + (unsigned) (text[i]));
1267 hi &= (1 << HASHBITS) - 1;
1268 hi %= MAX_HASH_TABLE;
1270 /* Search table for identifier */
1271 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1272 if (IDENTIFIER_LENGTH (idp) == len
1273 && IDENTIFIER_POINTER (idp)[0] == text[0]
1274 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1275 return idp; /* <-- return if found */
1277 /* Not found; optionally warn about a similar identifier */
1278 if (warn_id_clash && do_identifier_warnings && (unsigned)len >= id_clash_len)
1279 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1280 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1282 warning ("`%s' and `%s' identical in first %d characters",
1283 IDENTIFIER_POINTER (idp), text, id_clash_len);
1287 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1288 abort (); /* set_identifier_size hasn't been called. */
1290 /* Not found, create one, add to chain */
1291 idp = make_node (IDENTIFIER_NODE);
1292 IDENTIFIER_LENGTH (idp) = len;
1293 #ifdef GATHER_STATISTICS
1294 id_string_size += len;
1297 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1299 TREE_CHAIN (idp) = hash_table[hi];
1300 hash_table[hi] = idp;
1301 return idp; /* <-- return if created */
1304 /* If an identifier with the name TEXT (a null-terminated string) has
1305 previously been referred to, return that node; otherwise return
1309 maybe_get_identifier (text)
1310 register const char *text;
1315 register int len, hash_len;
1317 /* Compute length of text in len. */
1318 len = strlen (text);
1320 /* Decide how much of that length to hash on */
1322 if (warn_id_clash && (unsigned)len > id_clash_len)
1323 hash_len = id_clash_len;
1325 /* Compute hash code */
1326 hi = hash_len * 613 + (unsigned) text[0];
1327 for (i = 1; i < hash_len; i += 2)
1328 hi = ((hi * 613) + (unsigned) (text[i]));
1330 hi &= (1 << HASHBITS) - 1;
1331 hi %= MAX_HASH_TABLE;
1333 /* Search table for identifier */
1334 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1335 if (IDENTIFIER_LENGTH (idp) == len
1336 && IDENTIFIER_POINTER (idp)[0] == text[0]
1337 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1338 return idp; /* <-- return if found */
1343 /* Enable warnings on similar identifiers (if requested).
1344 Done after the built-in identifiers are created. */
1347 start_identifier_warnings ()
1349 do_identifier_warnings = 1;
1352 /* Record the size of an identifier node for the language in use.
1353 SIZE is the total size in bytes.
1354 This is called by the language-specific files. This must be
1355 called before allocating any identifiers. */
1358 set_identifier_size (size)
1361 tree_code_length[(int) IDENTIFIER_NODE]
1362 = (size - sizeof (struct tree_common)) / sizeof (tree);
1365 /* Return a newly constructed INTEGER_CST node whose constant value
1366 is specified by the two ints LOW and HI.
1367 The TREE_TYPE is set to `int'.
1369 This function should be used via the `build_int_2' macro. */
1372 build_int_2_wide (low, hi)
1373 HOST_WIDE_INT low, hi;
1375 register tree t = make_node (INTEGER_CST);
1376 TREE_INT_CST_LOW (t) = low;
1377 TREE_INT_CST_HIGH (t) = hi;
1378 TREE_TYPE (t) = integer_type_node;
1382 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1385 build_real (type, d)
1392 /* Check for valid float value for this type on this target machine;
1393 if not, can print error message and store a valid value in D. */
1394 #ifdef CHECK_FLOAT_VALUE
1395 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1398 v = make_node (REAL_CST);
1399 TREE_TYPE (v) = type;
1400 TREE_REAL_CST (v) = d;
1401 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1405 /* Return a new REAL_CST node whose type is TYPE
1406 and whose value is the integer value of the INTEGER_CST node I. */
1408 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1411 real_value_from_int_cst (type, i)
1416 #ifdef REAL_ARITHMETIC
1417 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1418 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1421 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i),
1422 TREE_INT_CST_HIGH (i), TYPE_MODE (type));
1423 #else /* not REAL_ARITHMETIC */
1424 /* Some 386 compilers mishandle unsigned int to float conversions,
1425 so introduce a temporary variable E to avoid those bugs. */
1426 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1430 d = (double) (~ TREE_INT_CST_HIGH (i));
1431 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1432 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1434 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1442 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1443 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1444 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1446 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1449 #endif /* not REAL_ARITHMETIC */
1453 /* This function can't be implemented if we can't do arithmetic
1454 on the float representation. */
1457 build_real_from_int_cst (type, i)
1462 int overflow = TREE_OVERFLOW (i);
1464 jmp_buf float_error;
1466 v = make_node (REAL_CST);
1467 TREE_TYPE (v) = type;
1469 if (setjmp (float_error))
1476 set_float_handler (float_error);
1478 #ifdef REAL_ARITHMETIC
1479 d = real_value_from_int_cst (type, i);
1481 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type),
1482 real_value_from_int_cst (type, i));
1485 /* Check for valid float value for this type on this target machine. */
1488 set_float_handler (NULL_PTR);
1490 #ifdef CHECK_FLOAT_VALUE
1491 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1494 TREE_REAL_CST (v) = d;
1495 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1499 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1501 /* Return a newly constructed STRING_CST node whose value is
1502 the LEN characters at STR.
1503 The TREE_TYPE is not initialized. */
1506 build_string (len, str)
1510 /* Put the string in saveable_obstack since it will be placed in the RTL
1511 for an "asm" statement and will also be kept around a while if
1512 deferring constant output in varasm.c. */
1514 register tree s = make_node (STRING_CST);
1515 TREE_STRING_LENGTH (s) = len;
1516 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1520 /* Return a newly constructed COMPLEX_CST node whose value is
1521 specified by the real and imaginary parts REAL and IMAG.
1522 Both REAL and IMAG should be constant nodes. TYPE, if specified,
1523 will be the type of the COMPLEX_CST; otherwise a new type will be made. */
1526 build_complex (type, real, imag)
1530 register tree t = make_node (COMPLEX_CST);
1532 TREE_REALPART (t) = real;
1533 TREE_IMAGPART (t) = imag;
1534 TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1535 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1536 TREE_CONSTANT_OVERFLOW (t)
1537 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1541 /* Build a newly constructed TREE_VEC node of length LEN. */
1548 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1549 register struct obstack *obstack = current_obstack;
1551 #ifdef GATHER_STATISTICS
1552 tree_node_counts[(int)vec_kind]++;
1553 tree_node_sizes[(int)vec_kind] += length;
1556 t = (tree) obstack_alloc (obstack, length);
1557 bzero ((PTR) t, length);
1559 TREE_SET_CODE (t, TREE_VEC);
1560 TREE_VEC_LENGTH (t) = len;
1561 if (obstack == &permanent_obstack)
1562 TREE_PERMANENT (t) = 1;
1567 /* Return 1 if EXPR is the integer constant zero or a complex constant
1571 integer_zerop (expr)
1576 return ((TREE_CODE (expr) == INTEGER_CST
1577 && ! TREE_CONSTANT_OVERFLOW (expr)
1578 && TREE_INT_CST_LOW (expr) == 0
1579 && TREE_INT_CST_HIGH (expr) == 0)
1580 || (TREE_CODE (expr) == COMPLEX_CST
1581 && integer_zerop (TREE_REALPART (expr))
1582 && integer_zerop (TREE_IMAGPART (expr))));
1585 /* Return 1 if EXPR is the integer constant one or the corresponding
1586 complex constant. */
1594 return ((TREE_CODE (expr) == INTEGER_CST
1595 && ! TREE_CONSTANT_OVERFLOW (expr)
1596 && TREE_INT_CST_LOW (expr) == 1
1597 && TREE_INT_CST_HIGH (expr) == 0)
1598 || (TREE_CODE (expr) == COMPLEX_CST
1599 && integer_onep (TREE_REALPART (expr))
1600 && integer_zerop (TREE_IMAGPART (expr))));
1603 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1604 it contains. Likewise for the corresponding complex constant. */
1607 integer_all_onesp (expr)
1615 if (TREE_CODE (expr) == COMPLEX_CST
1616 && integer_all_onesp (TREE_REALPART (expr))
1617 && integer_zerop (TREE_IMAGPART (expr)))
1620 else if (TREE_CODE (expr) != INTEGER_CST
1621 || TREE_CONSTANT_OVERFLOW (expr))
1624 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1626 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1628 /* Note that using TYPE_PRECISION here is wrong. We care about the
1629 actual bits, not the (arbitrary) range of the type. */
1630 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1631 if (prec >= HOST_BITS_PER_WIDE_INT)
1633 int high_value, shift_amount;
1635 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1637 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1638 /* Can not handle precisions greater than twice the host int size. */
1640 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1641 /* Shifting by the host word size is undefined according to the ANSI
1642 standard, so we must handle this as a special case. */
1645 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1647 return TREE_INT_CST_LOW (expr) == -1
1648 && TREE_INT_CST_HIGH (expr) == high_value;
1651 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1654 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1658 integer_pow2p (expr)
1662 HOST_WIDE_INT high, low;
1666 if (TREE_CODE (expr) == COMPLEX_CST
1667 && integer_pow2p (TREE_REALPART (expr))
1668 && integer_zerop (TREE_IMAGPART (expr)))
1671 if (TREE_CODE (expr) != INTEGER_CST || TREE_CONSTANT_OVERFLOW (expr))
1674 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1675 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1676 high = TREE_INT_CST_HIGH (expr);
1677 low = TREE_INT_CST_LOW (expr);
1679 /* First clear all bits that are beyond the type's precision in case
1680 we've been sign extended. */
1682 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1684 else if (prec > HOST_BITS_PER_WIDE_INT)
1685 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1689 if (prec < HOST_BITS_PER_WIDE_INT)
1690 low &= ~((HOST_WIDE_INT) (-1) << prec);
1693 if (high == 0 && low == 0)
1696 return ((high == 0 && (low & (low - 1)) == 0)
1697 || (low == 0 && (high & (high - 1)) == 0));
1700 /* Return the power of two represented by a tree node known to be a
1708 HOST_WIDE_INT high, low;
1712 if (TREE_CODE (expr) == COMPLEX_CST)
1713 return tree_log2 (TREE_REALPART (expr));
1715 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1716 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1718 high = TREE_INT_CST_HIGH (expr);
1719 low = TREE_INT_CST_LOW (expr);
1721 /* First clear all bits that are beyond the type's precision in case
1722 we've been sign extended. */
1724 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1726 else if (prec > HOST_BITS_PER_WIDE_INT)
1727 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1731 if (prec < HOST_BITS_PER_WIDE_INT)
1732 low &= ~((HOST_WIDE_INT) (-1) << prec);
1735 return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1736 : exact_log2 (low));
1739 /* Return 1 if EXPR is the real constant zero. */
1747 return ((TREE_CODE (expr) == REAL_CST
1748 && ! TREE_CONSTANT_OVERFLOW (expr)
1749 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1750 || (TREE_CODE (expr) == COMPLEX_CST
1751 && real_zerop (TREE_REALPART (expr))
1752 && real_zerop (TREE_IMAGPART (expr))));
1755 /* Return 1 if EXPR is the real constant one in real or complex form. */
1763 return ((TREE_CODE (expr) == REAL_CST
1764 && ! TREE_CONSTANT_OVERFLOW (expr)
1765 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1766 || (TREE_CODE (expr) == COMPLEX_CST
1767 && real_onep (TREE_REALPART (expr))
1768 && real_zerop (TREE_IMAGPART (expr))));
1771 /* Return 1 if EXPR is the real constant two. */
1779 return ((TREE_CODE (expr) == REAL_CST
1780 && ! TREE_CONSTANT_OVERFLOW (expr)
1781 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1782 || (TREE_CODE (expr) == COMPLEX_CST
1783 && real_twop (TREE_REALPART (expr))
1784 && real_zerop (TREE_IMAGPART (expr))));
1787 /* Nonzero if EXP is a constant or a cast of a constant. */
1790 really_constant_p (exp)
1793 /* This is not quite the same as STRIP_NOPS. It does more. */
1794 while (TREE_CODE (exp) == NOP_EXPR
1795 || TREE_CODE (exp) == CONVERT_EXPR
1796 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1797 exp = TREE_OPERAND (exp, 0);
1798 return TREE_CONSTANT (exp);
1801 /* Return first list element whose TREE_VALUE is ELEM.
1802 Return 0 if ELEM is not in LIST. */
1805 value_member (elem, list)
1810 if (elem == TREE_VALUE (list))
1812 list = TREE_CHAIN (list);
1817 /* Return first list element whose TREE_PURPOSE is ELEM.
1818 Return 0 if ELEM is not in LIST. */
1821 purpose_member (elem, list)
1826 if (elem == TREE_PURPOSE (list))
1828 list = TREE_CHAIN (list);
1833 /* Return first list element whose BINFO_TYPE is ELEM.
1834 Return 0 if ELEM is not in LIST. */
1837 binfo_member (elem, list)
1842 if (elem == BINFO_TYPE (list))
1844 list = TREE_CHAIN (list);
1849 /* Return nonzero if ELEM is part of the chain CHAIN. */
1852 chain_member (elem, chain)
1859 chain = TREE_CHAIN (chain);
1865 /* Return nonzero if ELEM is equal to TREE_VALUE (CHAIN) for any piece of
1867 /* ??? This function was added for machine specific attributes but is no
1868 longer used. It could be deleted if we could confirm all front ends
1872 chain_member_value (elem, chain)
1877 if (elem == TREE_VALUE (chain))
1879 chain = TREE_CHAIN (chain);
1885 /* Return nonzero if ELEM is equal to TREE_PURPOSE (CHAIN)
1886 for any piece of chain CHAIN. */
1887 /* ??? This function was added for machine specific attributes but is no
1888 longer used. It could be deleted if we could confirm all front ends
1892 chain_member_purpose (elem, chain)
1897 if (elem == TREE_PURPOSE (chain))
1899 chain = TREE_CHAIN (chain);
1905 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1906 We expect a null pointer to mark the end of the chain.
1907 This is the Lisp primitive `length'. */
1914 register int len = 0;
1916 for (tail = t; tail; tail = TREE_CHAIN (tail))
1922 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1923 by modifying the last node in chain 1 to point to chain 2.
1924 This is the Lisp primitive `nconc'. */
1936 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1938 TREE_CHAIN (t1) = op2;
1939 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1941 abort (); /* Circularity created. */
1947 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1951 register tree chain;
1955 while ((next = TREE_CHAIN (chain)))
1960 /* Reverse the order of elements in the chain T,
1961 and return the new head of the chain (old last element). */
1967 register tree prev = 0, decl, next;
1968 for (decl = t; decl; decl = next)
1970 next = TREE_CHAIN (decl);
1971 TREE_CHAIN (decl) = prev;
1977 /* Given a chain CHAIN of tree nodes,
1978 construct and return a list of those nodes. */
1984 tree result = NULL_TREE;
1985 tree in_tail = chain;
1986 tree out_tail = NULL_TREE;
1990 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1992 TREE_CHAIN (out_tail) = next;
1996 in_tail = TREE_CHAIN (in_tail);
2002 /* Return a newly created TREE_LIST node whose
2003 purpose and value fields are PARM and VALUE. */
2006 build_tree_list (parm, value)
2009 register tree t = make_node (TREE_LIST);
2010 TREE_PURPOSE (t) = parm;
2011 TREE_VALUE (t) = value;
2015 /* Similar, but build on the temp_decl_obstack. */
2018 build_decl_list (parm, value)
2022 register struct obstack *ambient_obstack = current_obstack;
2023 current_obstack = &temp_decl_obstack;
2024 node = build_tree_list (parm, value);
2025 current_obstack = ambient_obstack;
2029 /* Similar, but build on the expression_obstack. */
2032 build_expr_list (parm, value)
2036 register struct obstack *ambient_obstack = current_obstack;
2037 current_obstack = expression_obstack;
2038 node = build_tree_list (parm, value);
2039 current_obstack = ambient_obstack;
2043 /* Return a newly created TREE_LIST node whose
2044 purpose and value fields are PARM and VALUE
2045 and whose TREE_CHAIN is CHAIN. */
2048 tree_cons (purpose, value, chain)
2049 tree purpose, value, chain;
2052 register tree node = make_node (TREE_LIST);
2055 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
2056 #ifdef GATHER_STATISTICS
2057 tree_node_counts[(int)x_kind]++;
2058 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
2061 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
2062 ((int *) node)[i] = 0;
2064 TREE_SET_CODE (node, TREE_LIST);
2065 if (current_obstack == &permanent_obstack)
2066 TREE_PERMANENT (node) = 1;
2069 TREE_CHAIN (node) = chain;
2070 TREE_PURPOSE (node) = purpose;
2071 TREE_VALUE (node) = value;
2075 /* Similar, but build on the temp_decl_obstack. */
2078 decl_tree_cons (purpose, value, chain)
2079 tree purpose, value, chain;
2082 register struct obstack *ambient_obstack = current_obstack;
2083 current_obstack = &temp_decl_obstack;
2084 node = tree_cons (purpose, value, chain);
2085 current_obstack = ambient_obstack;
2089 /* Similar, but build on the expression_obstack. */
2092 expr_tree_cons (purpose, value, chain)
2093 tree purpose, value, chain;
2096 register struct obstack *ambient_obstack = current_obstack;
2097 current_obstack = expression_obstack;
2098 node = tree_cons (purpose, value, chain);
2099 current_obstack = ambient_obstack;
2103 /* Same as `tree_cons' but make a permanent object. */
2106 perm_tree_cons (purpose, value, chain)
2107 tree purpose, value, chain;
2110 register struct obstack *ambient_obstack = current_obstack;
2111 current_obstack = &permanent_obstack;
2113 node = tree_cons (purpose, value, chain);
2114 current_obstack = ambient_obstack;
2118 /* Same as `tree_cons', but make this node temporary, regardless. */
2121 temp_tree_cons (purpose, value, chain)
2122 tree purpose, value, chain;
2125 register struct obstack *ambient_obstack = current_obstack;
2126 current_obstack = &temporary_obstack;
2128 node = tree_cons (purpose, value, chain);
2129 current_obstack = ambient_obstack;
2133 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
2136 saveable_tree_cons (purpose, value, chain)
2137 tree purpose, value, chain;
2140 register struct obstack *ambient_obstack = current_obstack;
2141 current_obstack = saveable_obstack;
2143 node = tree_cons (purpose, value, chain);
2144 current_obstack = ambient_obstack;
2148 /* Return the size nominally occupied by an object of type TYPE
2149 when it resides in memory. The value is measured in units of bytes,
2150 and its data type is that normally used for type sizes
2151 (which is the first type created by make_signed_type or
2152 make_unsigned_type). */
2155 size_in_bytes (type)
2160 if (type == error_mark_node)
2161 return integer_zero_node;
2163 type = TYPE_MAIN_VARIANT (type);
2164 t = TYPE_SIZE_UNIT (type);
2167 incomplete_type_error (NULL_TREE, type);
2168 return integer_zero_node;
2170 if (TREE_CODE (t) == INTEGER_CST)
2171 force_fit_type (t, 0);
2176 /* Return the size of TYPE (in bytes) as a wide integer
2177 or return -1 if the size can vary or is larger than an integer. */
2180 int_size_in_bytes (type)
2185 if (type == error_mark_node)
2188 type = TYPE_MAIN_VARIANT (type);
2189 t = TYPE_SIZE_UNIT (type);
2191 || TREE_CODE (t) != INTEGER_CST
2192 || TREE_INT_CST_HIGH (t) != 0)
2195 return TREE_INT_CST_LOW (t);
2198 /* Return, as a tree node, the number of elements for TYPE (which is an
2199 ARRAY_TYPE) minus one. This counts only elements of the top array.
2201 Don't let any SAVE_EXPRs escape; if we are called as part of a cleanup
2202 action, they would get unsaved. */
2205 array_type_nelts (type)
2208 tree index_type, min, max;
2210 /* If they did it with unspecified bounds, then we should have already
2211 given an error about it before we got here. */
2212 if (! TYPE_DOMAIN (type))
2213 return error_mark_node;
2215 index_type = TYPE_DOMAIN (type);
2216 min = TYPE_MIN_VALUE (index_type);
2217 max = TYPE_MAX_VALUE (index_type);
2219 if (! TREE_CONSTANT (min))
2222 if (TREE_CODE (min) == SAVE_EXPR)
2223 min = build (RTL_EXPR, TREE_TYPE (TYPE_MIN_VALUE (index_type)), 0,
2224 SAVE_EXPR_RTL (min));
2226 min = TYPE_MIN_VALUE (index_type);
2229 if (! TREE_CONSTANT (max))
2232 if (TREE_CODE (max) == SAVE_EXPR)
2233 max = build (RTL_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)), 0,
2234 SAVE_EXPR_RTL (max));
2236 max = TYPE_MAX_VALUE (index_type);
2239 return (integer_zerop (min)
2241 : fold (build (MINUS_EXPR, TREE_TYPE (max), max, min)));
2244 /* Return nonzero if arg is static -- a reference to an object in
2245 static storage. This is not the same as the C meaning of `static'. */
2251 switch (TREE_CODE (arg))
2254 /* Nested functions aren't static, since taking their address
2255 involves a trampoline. */
2256 return (decl_function_context (arg) == 0 || DECL_NO_STATIC_CHAIN (arg))
2257 && ! DECL_NON_ADDR_CONST_P (arg);
2260 return (TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2261 && ! DECL_NON_ADDR_CONST_P (arg);
2264 return TREE_STATIC (arg);
2269 /* If we are referencing a bitfield, we can't evaluate an
2270 ADDR_EXPR at compile time and so it isn't a constant. */
2272 return (! DECL_BIT_FIELD (TREE_OPERAND (arg, 1))
2273 && staticp (TREE_OPERAND (arg, 0)));
2279 /* This case is technically correct, but results in setting
2280 TREE_CONSTANT on ADDR_EXPRs that cannot be evaluated at
2283 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
2287 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2288 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2289 return staticp (TREE_OPERAND (arg, 0));
2296 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2297 Do this to any expression which may be used in more than one place,
2298 but must be evaluated only once.
2300 Normally, expand_expr would reevaluate the expression each time.
2301 Calling save_expr produces something that is evaluated and recorded
2302 the first time expand_expr is called on it. Subsequent calls to
2303 expand_expr just reuse the recorded value.
2305 The call to expand_expr that generates code that actually computes
2306 the value is the first call *at compile time*. Subsequent calls
2307 *at compile time* generate code to use the saved value.
2308 This produces correct result provided that *at run time* control
2309 always flows through the insns made by the first expand_expr
2310 before reaching the other places where the save_expr was evaluated.
2311 You, the caller of save_expr, must make sure this is so.
2313 Constants, and certain read-only nodes, are returned with no
2314 SAVE_EXPR because that is safe. Expressions containing placeholders
2315 are not touched; see tree.def for an explanation of what these
2322 register tree t = fold (expr);
2324 /* We don't care about whether this can be used as an lvalue in this
2326 while (TREE_CODE (t) == NON_LVALUE_EXPR)
2327 t = TREE_OPERAND (t, 0);
2329 /* If the tree evaluates to a constant, then we don't want to hide that
2330 fact (i.e. this allows further folding, and direct checks for constants).
2331 However, a read-only object that has side effects cannot be bypassed.
2332 Since it is no problem to reevaluate literals, we just return the
2335 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
2336 || TREE_CODE (t) == SAVE_EXPR || TREE_CODE (t) == ERROR_MARK)
2339 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2340 it means that the size or offset of some field of an object depends on
2341 the value within another field.
2343 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2344 and some variable since it would then need to be both evaluated once and
2345 evaluated more than once. Front-ends must assure this case cannot
2346 happen by surrounding any such subexpressions in their own SAVE_EXPR
2347 and forcing evaluation at the proper time. */
2348 if (contains_placeholder_p (t))
2351 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
2353 /* This expression might be placed ahead of a jump to ensure that the
2354 value was computed on both sides of the jump. So make sure it isn't
2355 eliminated as dead. */
2356 TREE_SIDE_EFFECTS (t) = 1;
2360 /* Arrange for an expression to be expanded multiple independent
2361 times. This is useful for cleanup actions, as the backend can
2362 expand them multiple times in different places. */
2370 /* If this is already protected, no sense in protecting it again. */
2371 if (TREE_CODE (expr) == UNSAVE_EXPR)
2374 t = build1 (UNSAVE_EXPR, TREE_TYPE (expr), expr);
2375 TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
2379 /* Returns the index of the first non-tree operand for CODE, or the number
2380 of operands if all are trees. */
2384 enum tree_code code;
2394 case WITH_CLEANUP_EXPR:
2395 /* Should be defined to be 2. */
2397 case METHOD_CALL_EXPR:
2400 return tree_code_length [(int) code];
2404 /* Modify a tree in place so that all the evaluate only once things
2405 are cleared out. Return the EXPR given. */
2408 unsave_expr_now (expr)
2411 enum tree_code code;
2415 if (expr == NULL_TREE)
2418 code = TREE_CODE (expr);
2419 first_rtl = first_rtl_op (code);
2423 SAVE_EXPR_RTL (expr) = 0;
2427 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 3);
2428 TREE_OPERAND (expr, 3) = NULL_TREE;
2432 /* I don't yet know how to emit a sequence multiple times. */
2433 if (RTL_EXPR_SEQUENCE (expr) != 0)
2438 CALL_EXPR_RTL (expr) = 0;
2439 if (TREE_OPERAND (expr, 1)
2440 && TREE_CODE (TREE_OPERAND (expr, 1)) == TREE_LIST)
2442 tree exp = TREE_OPERAND (expr, 1);
2445 unsave_expr_now (TREE_VALUE (exp));
2446 exp = TREE_CHAIN (exp);
2455 switch (TREE_CODE_CLASS (code))
2457 case 'c': /* a constant */
2458 case 't': /* a type node */
2459 case 'x': /* something random, like an identifier or an ERROR_MARK. */
2460 case 'd': /* A decl node */
2461 case 'b': /* A block node */
2464 case 'e': /* an expression */
2465 case 'r': /* a reference */
2466 case 's': /* an expression with side effects */
2467 case '<': /* a comparison expression */
2468 case '2': /* a binary arithmetic expression */
2469 case '1': /* a unary arithmetic expression */
2470 for (i = first_rtl - 1; i >= 0; i--)
2471 unsave_expr_now (TREE_OPERAND (expr, i));
2479 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2480 or offset that depends on a field within a record. */
2483 contains_placeholder_p (exp)
2486 register enum tree_code code = TREE_CODE (exp);
2489 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2490 in it since it is supplying a value for it. */
2491 if (code == WITH_RECORD_EXPR)
2493 else if (code == PLACEHOLDER_EXPR)
2496 switch (TREE_CODE_CLASS (code))
2499 /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2500 position computations since they will be converted into a
2501 WITH_RECORD_EXPR involving the reference, which will assume
2502 here will be valid. */
2503 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2506 if (code == TREE_LIST)
2507 return (contains_placeholder_p (TREE_VALUE (exp))
2508 || (TREE_CHAIN (exp) != 0
2509 && contains_placeholder_p (TREE_CHAIN (exp))));
2518 /* Ignoring the first operand isn't quite right, but works best. */
2519 return contains_placeholder_p (TREE_OPERAND (exp, 1));
2526 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2527 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2528 || contains_placeholder_p (TREE_OPERAND (exp, 2)));
2531 /* If we already know this doesn't have a placeholder, don't
2533 if (SAVE_EXPR_NOPLACEHOLDER (exp) || SAVE_EXPR_RTL (exp) != 0)
2536 SAVE_EXPR_NOPLACEHOLDER (exp) = 1;
2537 result = contains_placeholder_p (TREE_OPERAND (exp, 0));
2539 SAVE_EXPR_NOPLACEHOLDER (exp) = 0;
2544 return (TREE_OPERAND (exp, 1) != 0
2545 && contains_placeholder_p (TREE_OPERAND (exp, 1)));
2551 switch (tree_code_length[(int) code])
2554 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2556 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2557 || contains_placeholder_p (TREE_OPERAND (exp, 1)));
2568 /* Return 1 if EXP contains any expressions that produce cleanups for an
2569 outer scope to deal with. Used by fold. */
2577 if (! TREE_SIDE_EFFECTS (exp))
2580 switch (TREE_CODE (exp))
2583 case WITH_CLEANUP_EXPR:
2586 case CLEANUP_POINT_EXPR:
2590 for (exp = TREE_OPERAND (exp, 1); exp; exp = TREE_CHAIN (exp))
2592 cmp = has_cleanups (TREE_VALUE (exp));
2602 /* This general rule works for most tree codes. All exceptions should be
2603 handled above. If this is a language-specific tree code, we can't
2604 trust what might be in the operand, so say we don't know
2606 if ((int) TREE_CODE (exp) >= (int) LAST_AND_UNUSED_TREE_CODE)
2609 nops = first_rtl_op (TREE_CODE (exp));
2610 for (i = 0; i < nops; i++)
2611 if (TREE_OPERAND (exp, i) != 0)
2613 int type = TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, i)));
2614 if (type == 'e' || type == '<' || type == '1' || type == '2'
2615 || type == 'r' || type == 's')
2617 cmp = has_cleanups (TREE_OPERAND (exp, i));
2626 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2627 return a tree with all occurrences of references to F in a
2628 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2629 contains only arithmetic expressions or a CALL_EXPR with a
2630 PLACEHOLDER_EXPR occurring only in its arglist. */
2633 substitute_in_expr (exp, f, r)
2638 enum tree_code code = TREE_CODE (exp);
2643 switch (TREE_CODE_CLASS (code))
2650 if (code == PLACEHOLDER_EXPR)
2652 else if (code == TREE_LIST)
2654 op0 = (TREE_CHAIN (exp) == 0
2655 ? 0 : substitute_in_expr (TREE_CHAIN (exp), f, r));
2656 op1 = substitute_in_expr (TREE_VALUE (exp), f, r);
2657 if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2660 return tree_cons (TREE_PURPOSE (exp), op1, op0);
2669 switch (tree_code_length[(int) code])
2672 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2673 if (op0 == TREE_OPERAND (exp, 0))
2676 new = fold (build1 (code, TREE_TYPE (exp), op0));
2680 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2681 could, but we don't support it. */
2682 if (code == RTL_EXPR)
2684 else if (code == CONSTRUCTOR)
2687 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2688 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2689 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2692 new = fold (build (code, TREE_TYPE (exp), op0, op1));
2696 /* It cannot be that anything inside a SAVE_EXPR contains a
2697 PLACEHOLDER_EXPR. */
2698 if (code == SAVE_EXPR)
2701 else if (code == CALL_EXPR)
2703 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2704 if (op1 == TREE_OPERAND (exp, 1))
2707 return build (code, TREE_TYPE (exp),
2708 TREE_OPERAND (exp, 0), op1, NULL_TREE);
2711 else if (code != COND_EXPR)
2714 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2715 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2716 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2717 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2718 && op2 == TREE_OPERAND (exp, 2))
2721 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2734 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2735 and it is the right field, replace it with R. */
2736 for (inner = TREE_OPERAND (exp, 0);
2737 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2738 inner = TREE_OPERAND (inner, 0))
2740 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2741 && TREE_OPERAND (exp, 1) == f)
2744 /* If this expression hasn't been completed let, leave it
2746 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2747 && TREE_TYPE (inner) == 0)
2750 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2751 if (op0 == TREE_OPERAND (exp, 0))
2754 new = fold (build (code, TREE_TYPE (exp), op0,
2755 TREE_OPERAND (exp, 1)));
2759 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2760 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2761 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2762 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2763 && op2 == TREE_OPERAND (exp, 2))
2766 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2771 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2772 if (op0 == TREE_OPERAND (exp, 0))
2775 new = fold (build1 (code, TREE_TYPE (exp), op0));
2787 TREE_READONLY (new) = TREE_READONLY (exp);
2791 /* Stabilize a reference so that we can use it any number of times
2792 without causing its operands to be evaluated more than once.
2793 Returns the stabilized reference. This works by means of save_expr,
2794 so see the caveats in the comments about save_expr.
2796 Also allows conversion expressions whose operands are references.
2797 Any other kind of expression is returned unchanged. */
2800 stabilize_reference (ref)
2803 register tree result;
2804 register enum tree_code code = TREE_CODE (ref);
2811 /* No action is needed in this case. */
2817 case FIX_TRUNC_EXPR:
2818 case FIX_FLOOR_EXPR:
2819 case FIX_ROUND_EXPR:
2821 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2825 result = build_nt (INDIRECT_REF,
2826 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2830 result = build_nt (COMPONENT_REF,
2831 stabilize_reference (TREE_OPERAND (ref, 0)),
2832 TREE_OPERAND (ref, 1));
2836 result = build_nt (BIT_FIELD_REF,
2837 stabilize_reference (TREE_OPERAND (ref, 0)),
2838 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2839 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2843 result = build_nt (ARRAY_REF,
2844 stabilize_reference (TREE_OPERAND (ref, 0)),
2845 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2849 /* We cannot wrap the first expression in a SAVE_EXPR, as then
2850 it wouldn't be ignored. This matters when dealing with
2852 return stabilize_reference_1 (ref);
2855 result = build1 (INDIRECT_REF, TREE_TYPE (ref),
2856 save_expr (build1 (ADDR_EXPR,
2857 build_pointer_type (TREE_TYPE (ref)),
2862 /* If arg isn't a kind of lvalue we recognize, make no change.
2863 Caller should recognize the error for an invalid lvalue. */
2868 return error_mark_node;
2871 TREE_TYPE (result) = TREE_TYPE (ref);
2872 TREE_READONLY (result) = TREE_READONLY (ref);
2873 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2874 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2875 TREE_RAISES (result) = TREE_RAISES (ref);
2880 /* Subroutine of stabilize_reference; this is called for subtrees of
2881 references. Any expression with side-effects must be put in a SAVE_EXPR
2882 to ensure that it is only evaluated once.
2884 We don't put SAVE_EXPR nodes around everything, because assigning very
2885 simple expressions to temporaries causes us to miss good opportunities
2886 for optimizations. Among other things, the opportunity to fold in the
2887 addition of a constant into an addressing mode often gets lost, e.g.
2888 "y[i+1] += x;". In general, we take the approach that we should not make
2889 an assignment unless we are forced into it - i.e., that any non-side effect
2890 operator should be allowed, and that cse should take care of coalescing
2891 multiple utterances of the same expression should that prove fruitful. */
2894 stabilize_reference_1 (e)
2897 register tree result;
2898 register enum tree_code code = TREE_CODE (e);
2900 /* We cannot ignore const expressions because it might be a reference
2901 to a const array but whose index contains side-effects. But we can
2902 ignore things that are actual constant or that already have been
2903 handled by this function. */
2905 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2908 switch (TREE_CODE_CLASS (code))
2918 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2919 so that it will only be evaluated once. */
2920 /* The reference (r) and comparison (<) classes could be handled as
2921 below, but it is generally faster to only evaluate them once. */
2922 if (TREE_SIDE_EFFECTS (e))
2923 return save_expr (e);
2927 /* Constants need no processing. In fact, we should never reach
2932 /* Division is slow and tends to be compiled with jumps,
2933 especially the division by powers of 2 that is often
2934 found inside of an array reference. So do it just once. */
2935 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2936 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2937 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2938 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2939 return save_expr (e);
2940 /* Recursively stabilize each operand. */
2941 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2942 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2946 /* Recursively stabilize each operand. */
2947 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2954 TREE_TYPE (result) = TREE_TYPE (e);
2955 TREE_READONLY (result) = TREE_READONLY (e);
2956 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2957 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2958 TREE_RAISES (result) = TREE_RAISES (e);
2963 /* Low-level constructors for expressions. */
2965 /* Build an expression of code CODE, data type TYPE,
2966 and operands as specified by the arguments ARG1 and following arguments.
2967 Expressions and reference nodes can be created this way.
2968 Constants, decls, types and misc nodes cannot be. */
2971 build VPROTO((enum tree_code code, tree tt, ...))
2973 #ifndef ANSI_PROTOTYPES
2974 enum tree_code code;
2979 register int length;
2984 #ifndef ANSI_PROTOTYPES
2985 code = va_arg (p, enum tree_code);
2986 tt = va_arg (p, tree);
2989 t = make_node (code);
2990 length = tree_code_length[(int) code];
2995 /* This is equivalent to the loop below, but faster. */
2996 register tree arg0 = va_arg (p, tree);
2997 register tree arg1 = va_arg (p, tree);
2998 TREE_OPERAND (t, 0) = arg0;
2999 TREE_OPERAND (t, 1) = arg1;
3000 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
3001 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
3002 TREE_SIDE_EFFECTS (t) = 1;
3004 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
3006 else if (length == 1)
3008 register tree arg0 = va_arg (p, tree);
3010 /* Call build1 for this! */
3011 if (TREE_CODE_CLASS (code) != 's')
3013 TREE_OPERAND (t, 0) = arg0;
3014 if (arg0 && TREE_SIDE_EFFECTS (arg0))
3015 TREE_SIDE_EFFECTS (t) = 1;
3016 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
3020 for (i = 0; i < length; i++)
3022 register tree operand = va_arg (p, tree);
3023 TREE_OPERAND (t, i) = operand;
3026 if (TREE_SIDE_EFFECTS (operand))
3027 TREE_SIDE_EFFECTS (t) = 1;
3028 if (TREE_RAISES (operand))
3029 TREE_RAISES (t) = 1;
3037 /* Same as above, but only builds for unary operators.
3038 Saves lions share of calls to `build'; cuts down use
3039 of varargs, which is expensive for RISC machines. */
3042 build1 (code, type, node)
3043 enum tree_code code;
3047 register struct obstack *obstack = expression_obstack;
3048 register int length;
3049 #ifdef GATHER_STATISTICS
3050 register tree_node_kind kind;
3054 #ifdef GATHER_STATISTICS
3055 if (TREE_CODE_CLASS (code) == 'r')
3061 length = sizeof (struct tree_exp);
3063 t = (tree) obstack_alloc (obstack, length);
3064 bzero ((PTR) t, length);
3066 #ifdef GATHER_STATISTICS
3067 tree_node_counts[(int)kind]++;
3068 tree_node_sizes[(int)kind] += length;
3071 TREE_TYPE (t) = type;
3072 TREE_SET_CODE (t, code);
3074 if (obstack == &permanent_obstack)
3075 TREE_PERMANENT (t) = 1;
3077 TREE_OPERAND (t, 0) = node;
3080 if (TREE_SIDE_EFFECTS (node))
3081 TREE_SIDE_EFFECTS (t) = 1;
3082 if (TREE_RAISES (node))
3083 TREE_RAISES (t) = 1;
3089 /* Similar except don't specify the TREE_TYPE
3090 and leave the TREE_SIDE_EFFECTS as 0.
3091 It is permissible for arguments to be null,
3092 or even garbage if their values do not matter. */
3095 build_nt VPROTO((enum tree_code code, ...))
3097 #ifndef ANSI_PROTOTYPES
3098 enum tree_code code;
3102 register int length;
3107 #ifndef ANSI_PROTOTYPES
3108 code = va_arg (p, enum tree_code);
3111 t = make_node (code);
3112 length = tree_code_length[(int) code];
3114 for (i = 0; i < length; i++)
3115 TREE_OPERAND (t, i) = va_arg (p, tree);
3121 /* Similar to `build_nt', except we build
3122 on the temp_decl_obstack, regardless. */
3125 build_parse_node VPROTO((enum tree_code code, ...))
3127 #ifndef ANSI_PROTOTYPES
3128 enum tree_code code;
3130 register struct obstack *ambient_obstack = expression_obstack;
3133 register int length;
3138 #ifndef ANSI_PROTOTYPES
3139 code = va_arg (p, enum tree_code);
3142 expression_obstack = &temp_decl_obstack;
3144 t = make_node (code);
3145 length = tree_code_length[(int) code];
3147 for (i = 0; i < length; i++)
3148 TREE_OPERAND (t, i) = va_arg (p, tree);
3151 expression_obstack = ambient_obstack;
3156 /* Commented out because this wants to be done very
3157 differently. See cp-lex.c. */
3159 build_op_identifier (op1, op2)
3162 register tree t = make_node (OP_IDENTIFIER);
3163 TREE_PURPOSE (t) = op1;
3164 TREE_VALUE (t) = op2;
3169 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3170 We do NOT enter this node in any sort of symbol table.
3172 layout_decl is used to set up the decl's storage layout.
3173 Other slots are initialized to 0 or null pointers. */
3176 build_decl (code, name, type)
3177 enum tree_code code;
3182 t = make_node (code);
3184 /* if (type == error_mark_node)
3185 type = integer_type_node; */
3186 /* That is not done, deliberately, so that having error_mark_node
3187 as the type can suppress useless errors in the use of this variable. */
3189 DECL_NAME (t) = name;
3190 DECL_ASSEMBLER_NAME (t) = name;
3191 TREE_TYPE (t) = type;
3193 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3195 else if (code == FUNCTION_DECL)
3196 DECL_MODE (t) = FUNCTION_MODE;
3201 /* BLOCK nodes are used to represent the structure of binding contours
3202 and declarations, once those contours have been exited and their contents
3203 compiled. This information is used for outputting debugging info. */
3206 build_block (vars, tags, subblocks, supercontext, chain)
3207 tree vars, tags, subblocks, supercontext, chain;
3209 register tree block = make_node (BLOCK);
3210 BLOCK_VARS (block) = vars;
3211 BLOCK_TYPE_TAGS (block) = tags;
3212 BLOCK_SUBBLOCKS (block) = subblocks;
3213 BLOCK_SUPERCONTEXT (block) = supercontext;
3214 BLOCK_CHAIN (block) = chain;
3218 /* EXPR_WITH_FILE_LOCATION are used to keep track of the exact
3219 location where an expression or an identifier were encountered. It
3220 is necessary for languages where the frontend parser will handle
3221 recursively more than one file (Java is one of them). */
3224 build_expr_wfl (node, file, line, col)
3229 static const char *last_file = 0;
3230 static tree last_filenode = NULL_TREE;
3231 register tree wfl = make_node (EXPR_WITH_FILE_LOCATION);
3233 EXPR_WFL_NODE (wfl) = node;
3234 EXPR_WFL_SET_LINECOL (wfl, line, col);
3235 if (file != last_file)
3238 last_filenode = file ? get_identifier (file) : NULL_TREE;
3240 EXPR_WFL_FILENAME_NODE (wfl) = last_filenode;
3243 TREE_SIDE_EFFECTS (wfl) = TREE_SIDE_EFFECTS (node);
3244 TREE_TYPE (wfl) = TREE_TYPE (node);
3249 /* Return a declaration like DDECL except that its DECL_MACHINE_ATTRIBUTE
3253 build_decl_attribute_variant (ddecl, attribute)
3254 tree ddecl, attribute;
3256 DECL_MACHINE_ATTRIBUTES (ddecl) = attribute;
3260 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3263 Record such modified types already made so we don't make duplicates. */
3266 build_type_attribute_variant (ttype, attribute)
3267 tree ttype, attribute;
3269 if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3271 register int hashcode;
3272 register struct obstack *ambient_obstack = current_obstack;
3275 if (ambient_obstack != &permanent_obstack)
3276 current_obstack = TYPE_OBSTACK (ttype);
3278 ntype = copy_node (ttype);
3279 current_obstack = ambient_obstack;
3281 TYPE_POINTER_TO (ntype) = 0;
3282 TYPE_REFERENCE_TO (ntype) = 0;
3283 TYPE_ATTRIBUTES (ntype) = attribute;
3285 /* Create a new main variant of TYPE. */
3286 TYPE_MAIN_VARIANT (ntype) = ntype;
3287 TYPE_NEXT_VARIANT (ntype) = 0;
3288 set_type_quals (ntype, TYPE_UNQUALIFIED);
3290 hashcode = TYPE_HASH (TREE_CODE (ntype))
3291 + TYPE_HASH (TREE_TYPE (ntype))
3292 + attribute_hash_list (attribute);
3294 switch (TREE_CODE (ntype))
3297 hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype));
3300 hashcode += TYPE_HASH (TYPE_DOMAIN (ntype));
3303 hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype));
3306 hashcode += TYPE_HASH (TYPE_PRECISION (ntype));
3312 ntype = type_hash_canon (hashcode, ntype);
3313 ttype = build_qualified_type (ntype, TYPE_QUALS (ttype));
3319 /* Return a 1 if ATTR_NAME and ATTR_ARGS is valid for either declaration DECL
3320 or type TYPE and 0 otherwise. Validity is determined the configuration
3321 macros VALID_MACHINE_DECL_ATTRIBUTE and VALID_MACHINE_TYPE_ATTRIBUTE. */
3324 valid_machine_attribute (attr_name, attr_args, decl, type)
3326 tree attr_args ATTRIBUTE_UNUSED;
3327 tree decl ATTRIBUTE_UNUSED;
3328 tree type ATTRIBUTE_UNUSED;
3331 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3332 tree decl_attr_list = decl != 0 ? DECL_MACHINE_ATTRIBUTES (decl) : 0;
3334 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3335 tree type_attr_list = TYPE_ATTRIBUTES (type);
3338 if (TREE_CODE (attr_name) != IDENTIFIER_NODE)
3341 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3343 && VALID_MACHINE_DECL_ATTRIBUTE (decl, decl_attr_list, attr_name, attr_args))
3345 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3348 if (attr != NULL_TREE)
3350 /* Override existing arguments. Declarations are unique so we can
3351 modify this in place. */
3352 TREE_VALUE (attr) = attr_args;
3356 decl_attr_list = tree_cons (attr_name, attr_args, decl_attr_list);
3357 decl = build_decl_attribute_variant (decl, decl_attr_list);
3364 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3366 /* Don't apply the attribute to both the decl and the type. */;
3367 else if (VALID_MACHINE_TYPE_ATTRIBUTE (type, type_attr_list, attr_name,
3370 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3373 if (attr != NULL_TREE)
3375 /* Override existing arguments.
3376 ??? This currently works since attribute arguments are not
3377 included in `attribute_hash_list'. Something more complicated
3378 may be needed in the future. */
3379 TREE_VALUE (attr) = attr_args;
3383 /* If this is part of a declaration, create a type variant,
3384 otherwise, this is part of a type definition, so add it
3385 to the base type. */
3386 type_attr_list = tree_cons (attr_name, attr_args, type_attr_list);
3388 type = build_type_attribute_variant (type, type_attr_list);
3390 TYPE_ATTRIBUTES (type) = type_attr_list;
3393 TREE_TYPE (decl) = type;
3397 /* Handle putting a type attribute on pointer-to-function-type by putting
3398 the attribute on the function type. */
3399 else if (POINTER_TYPE_P (type)
3400 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3401 && VALID_MACHINE_TYPE_ATTRIBUTE (TREE_TYPE (type), type_attr_list,
3402 attr_name, attr_args))
3404 tree inner_type = TREE_TYPE (type);
3405 tree inner_attr_list = TYPE_ATTRIBUTES (inner_type);
3406 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3409 if (attr != NULL_TREE)
3410 TREE_VALUE (attr) = attr_args;
3413 inner_attr_list = tree_cons (attr_name, attr_args, inner_attr_list);
3414 inner_type = build_type_attribute_variant (inner_type,
3419 TREE_TYPE (decl) = build_pointer_type (inner_type);
3428 /* Return non-zero if IDENT is a valid name for attribute ATTR,
3431 We try both `text' and `__text__', ATTR may be either one. */
3432 /* ??? It might be a reasonable simplification to require ATTR to be only
3433 `text'. One might then also require attribute lists to be stored in
3434 their canonicalized form. */
3437 is_attribute_p (attr, ident)
3441 int ident_len, attr_len;
3444 if (TREE_CODE (ident) != IDENTIFIER_NODE)
3447 if (strcmp (attr, IDENTIFIER_POINTER (ident)) == 0)
3450 p = IDENTIFIER_POINTER (ident);
3451 ident_len = strlen (p);
3452 attr_len = strlen (attr);
3454 /* If ATTR is `__text__', IDENT must be `text'; and vice versa. */
3458 || attr[attr_len - 2] != '_'
3459 || attr[attr_len - 1] != '_')
3461 if (ident_len == attr_len - 4
3462 && strncmp (attr + 2, p, attr_len - 4) == 0)
3467 if (ident_len == attr_len + 4
3468 && p[0] == '_' && p[1] == '_'
3469 && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3470 && strncmp (attr, p + 2, attr_len) == 0)
3477 /* Given an attribute name and a list of attributes, return a pointer to the
3478 attribute's list element if the attribute is part of the list, or NULL_TREE
3482 lookup_attribute (attr_name, list)
3483 const char *attr_name;
3488 for (l = list; l; l = TREE_CHAIN (l))
3490 if (TREE_CODE (TREE_PURPOSE (l)) != IDENTIFIER_NODE)
3492 if (is_attribute_p (attr_name, TREE_PURPOSE (l)))
3499 /* Return an attribute list that is the union of a1 and a2. */
3502 merge_attributes (a1, a2)
3503 register tree a1, a2;
3507 /* Either one unset? Take the set one. */
3509 if (! (attributes = a1))
3512 /* One that completely contains the other? Take it. */
3514 else if (a2 && ! attribute_list_contained (a1, a2))
3516 if (attribute_list_contained (a2, a1))
3520 /* Pick the longest list, and hang on the other list. */
3521 /* ??? For the moment we punt on the issue of attrs with args. */
3523 if (list_length (a1) < list_length (a2))
3524 attributes = a2, a2 = a1;
3526 for (; a2; a2 = TREE_CHAIN (a2))
3527 if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3528 attributes) == NULL_TREE)
3530 a1 = copy_node (a2);
3531 TREE_CHAIN (a1) = attributes;
3539 /* Given types T1 and T2, merge their attributes and return
3543 merge_machine_type_attributes (t1, t2)
3546 #ifdef MERGE_MACHINE_TYPE_ATTRIBUTES
3547 return MERGE_MACHINE_TYPE_ATTRIBUTES (t1, t2);
3549 return merge_attributes (TYPE_ATTRIBUTES (t1),
3550 TYPE_ATTRIBUTES (t2));
3554 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3558 merge_machine_decl_attributes (olddecl, newdecl)
3559 tree olddecl, newdecl;
3561 #ifdef MERGE_MACHINE_DECL_ATTRIBUTES
3562 return MERGE_MACHINE_DECL_ATTRIBUTES (olddecl, newdecl);
3564 return merge_attributes (DECL_MACHINE_ATTRIBUTES (olddecl),
3565 DECL_MACHINE_ATTRIBUTES (newdecl));
3569 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
3570 of the various TYPE_QUAL values. */
3573 set_type_quals (type, type_quals)
3577 TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
3578 TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
3579 TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
3582 /* Given a type node TYPE and a TYPE_QUALIFIER_SET, return a type for
3583 the same kind of data as TYPE describes. Variants point to the
3584 "main variant" (which has no qualifiers set) via TYPE_MAIN_VARIANT,
3585 and it points to a chain of other variants so that duplicate
3586 variants are never made. Only main variants should ever appear as
3587 types of expressions. */
3590 build_qualified_type (type, type_quals)
3596 /* Search the chain of variants to see if there is already one there just
3597 like the one we need to have. If so, use that existing one. We must
3598 preserve the TYPE_NAME, since there is code that depends on this. */
3600 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3601 if (TYPE_QUALS (t) == type_quals && TYPE_NAME (t) == TYPE_NAME (type))
3604 /* We need a new one. */
3605 t = build_type_copy (type);
3606 set_type_quals (t, type_quals);
3610 /* Create a new variant of TYPE, equivalent but distinct.
3611 This is so the caller can modify it. */
3614 build_type_copy (type)
3617 register tree t, m = TYPE_MAIN_VARIANT (type);
3618 register struct obstack *ambient_obstack = current_obstack;
3620 current_obstack = TYPE_OBSTACK (type);
3621 t = copy_node (type);
3622 current_obstack = ambient_obstack;
3624 TYPE_POINTER_TO (t) = 0;
3625 TYPE_REFERENCE_TO (t) = 0;
3627 /* Add this type to the chain of variants of TYPE. */
3628 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
3629 TYPE_NEXT_VARIANT (m) = t;
3634 /* Hashing of types so that we don't make duplicates.
3635 The entry point is `type_hash_canon'. */
3637 /* Each hash table slot is a bucket containing a chain
3638 of these structures. */
3642 struct type_hash *next; /* Next structure in the bucket. */
3643 int hashcode; /* Hash code of this type. */
3644 tree type; /* The type recorded here. */
3647 /* Now here is the hash table. When recording a type, it is added
3648 to the slot whose index is the hash code mod the table size.
3649 Note that the hash table is used for several kinds of types
3650 (function types, array types and array index range types, for now).
3651 While all these live in the same table, they are completely independent,
3652 and the hash code is computed differently for each of these. */
3654 #define TYPE_HASH_SIZE 59
3655 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
3657 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
3658 with types in the TREE_VALUE slots), by adding the hash codes
3659 of the individual types. */
3662 type_hash_list (list)
3665 register int hashcode;
3667 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3668 hashcode += TYPE_HASH (TREE_VALUE (tail));
3672 /* Look in the type hash table for a type isomorphic to TYPE.
3673 If one is found, return it. Otherwise return 0. */
3676 type_hash_lookup (hashcode, type)
3680 register struct type_hash *h;
3681 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
3682 if (h->hashcode == hashcode
3683 && TREE_CODE (h->type) == TREE_CODE (type)
3684 && TREE_TYPE (h->type) == TREE_TYPE (type)
3685 && attribute_list_equal (TYPE_ATTRIBUTES (h->type),
3686 TYPE_ATTRIBUTES (type))
3687 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
3688 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
3689 TYPE_MAX_VALUE (type)))
3690 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
3691 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
3692 TYPE_MIN_VALUE (type)))
3693 /* Note that TYPE_DOMAIN is TYPE_ARG_TYPES for FUNCTION_TYPE. */
3694 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
3695 || (TYPE_DOMAIN (h->type)
3696 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
3697 && TYPE_DOMAIN (type)
3698 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
3699 && type_list_equal (TYPE_DOMAIN (h->type),
3700 TYPE_DOMAIN (type)))))
3705 /* Add an entry to the type-hash-table
3706 for a type TYPE whose hash code is HASHCODE. */
3709 type_hash_add (hashcode, type)
3713 register struct type_hash *h;
3715 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
3716 h->hashcode = hashcode;
3718 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
3719 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
3722 /* Given TYPE, and HASHCODE its hash code, return the canonical
3723 object for an identical type if one already exists.
3724 Otherwise, return TYPE, and record it as the canonical object
3725 if it is a permanent object.
3727 To use this function, first create a type of the sort you want.
3728 Then compute its hash code from the fields of the type that
3729 make it different from other similar types.
3730 Then call this function and use the value.
3731 This function frees the type you pass in if it is a duplicate. */
3733 /* Set to 1 to debug without canonicalization. Never set by program. */
3734 int debug_no_type_hash = 0;
3737 type_hash_canon (hashcode, type)
3743 if (debug_no_type_hash)
3746 t1 = type_hash_lookup (hashcode, type);
3749 obstack_free (TYPE_OBSTACK (type), type);
3750 #ifdef GATHER_STATISTICS
3751 tree_node_counts[(int)t_kind]--;
3752 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
3757 /* If this is a permanent type, record it for later reuse. */
3758 if (TREE_PERMANENT (type))
3759 type_hash_add (hashcode, type);
3764 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
3765 with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
3766 by adding the hash codes of the individual attributes. */
3769 attribute_hash_list (list)
3772 register int hashcode;
3774 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3775 /* ??? Do we want to add in TREE_VALUE too? */
3776 hashcode += TYPE_HASH (TREE_PURPOSE (tail));
3780 /* Given two lists of attributes, return true if list l2 is
3781 equivalent to l1. */
3784 attribute_list_equal (l1, l2)
3787 return attribute_list_contained (l1, l2)
3788 && attribute_list_contained (l2, l1);
3791 /* Given two lists of attributes, return true if list L2 is
3792 completely contained within L1. */
3793 /* ??? This would be faster if attribute names were stored in a canonicalized
3794 form. Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
3795 must be used to show these elements are equivalent (which they are). */
3796 /* ??? It's not clear that attributes with arguments will always be handled
3800 attribute_list_contained (l1, l2)
3803 register tree t1, t2;
3805 /* First check the obvious, maybe the lists are identical. */
3809 /* Maybe the lists are similar. */
3810 for (t1 = l1, t2 = l2;
3812 && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
3813 && TREE_VALUE (t1) == TREE_VALUE (t2);
3814 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
3816 /* Maybe the lists are equal. */
3817 if (t1 == 0 && t2 == 0)
3820 for (; t2; t2 = TREE_CHAIN (t2))
3823 = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)), l1);
3825 if (attr == NULL_TREE)
3827 if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) != 1)
3834 /* Given two lists of types
3835 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
3836 return 1 if the lists contain the same types in the same order.
3837 Also, the TREE_PURPOSEs must match. */
3840 type_list_equal (l1, l2)
3843 register tree t1, t2;
3845 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
3846 if (TREE_VALUE (t1) != TREE_VALUE (t2)
3847 || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
3848 && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
3849 && (TREE_TYPE (TREE_PURPOSE (t1))
3850 == TREE_TYPE (TREE_PURPOSE (t2))))))
3856 /* Nonzero if integer constants T1 and T2
3857 represent the same constant value. */
3860 tree_int_cst_equal (t1, t2)
3865 if (t1 == 0 || t2 == 0)
3867 if (TREE_CODE (t1) == INTEGER_CST
3868 && TREE_CODE (t2) == INTEGER_CST
3869 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3870 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
3875 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
3876 The precise way of comparison depends on their data type. */
3879 tree_int_cst_lt (t1, t2)
3885 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
3886 return INT_CST_LT (t1, t2);
3887 return INT_CST_LT_UNSIGNED (t1, t2);
3890 /* Return an indication of the sign of the integer constant T.
3891 The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
3892 Note that -1 will never be returned it T's type is unsigned. */
3895 tree_int_cst_sgn (t)
3898 if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
3900 else if (TREE_UNSIGNED (TREE_TYPE (t)))
3902 else if (TREE_INT_CST_HIGH (t) < 0)
3908 /* Compare two constructor-element-type constants. Return 1 if the lists
3909 are known to be equal; otherwise return 0. */
3912 simple_cst_list_equal (l1, l2)
3915 while (l1 != NULL_TREE && l2 != NULL_TREE)
3917 if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
3920 l1 = TREE_CHAIN (l1);
3921 l2 = TREE_CHAIN (l2);
3927 /* Return truthvalue of whether T1 is the same tree structure as T2.
3928 Return 1 if they are the same.
3929 Return 0 if they are understandably different.
3930 Return -1 if either contains tree structure not understood by
3934 simple_cst_equal (t1, t2)
3937 register enum tree_code code1, code2;
3942 if (t1 == 0 || t2 == 0)
3945 code1 = TREE_CODE (t1);
3946 code2 = TREE_CODE (t2);
3948 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
3950 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3951 || code2 == NON_LVALUE_EXPR)
3952 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3954 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
3956 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3957 || code2 == NON_LVALUE_EXPR)
3958 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
3966 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3967 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
3970 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
3973 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
3974 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
3975 TREE_STRING_LENGTH (t1));
3978 if (CONSTRUCTOR_ELTS (t1) == CONSTRUCTOR_ELTS (t2))
3984 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3987 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3990 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3993 /* Special case: if either target is an unallocated VAR_DECL,
3994 it means that it's going to be unified with whatever the
3995 TARGET_EXPR is really supposed to initialize, so treat it
3996 as being equivalent to anything. */
3997 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
3998 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
3999 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
4000 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
4001 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
4002 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
4005 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4008 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
4010 case WITH_CLEANUP_EXPR:
4011 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4014 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
4017 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
4018 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4031 /* This general rule works for most tree codes. All exceptions should be
4032 handled above. If this is a language-specific tree code, we can't
4033 trust what might be in the operand, so say we don't know
4035 if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
4038 switch (TREE_CODE_CLASS (code1))
4048 for (i=0; i<tree_code_length[(int) code1]; ++i)
4050 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
4061 /* Constructors for pointer, array and function types.
4062 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
4063 constructed by language-dependent code, not here.) */
4065 /* Construct, lay out and return the type of pointers to TO_TYPE.
4066 If such a type has already been constructed, reuse it. */
4069 build_pointer_type (to_type)
4072 register tree t = TYPE_POINTER_TO (to_type);
4074 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4079 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4080 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4081 t = make_node (POINTER_TYPE);
4084 TREE_TYPE (t) = to_type;
4086 /* Record this type as the pointer to TO_TYPE. */
4087 TYPE_POINTER_TO (to_type) = t;
4089 /* Lay out the type. This function has many callers that are concerned
4090 with expression-construction, and this simplifies them all.
4091 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
4097 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
4098 MAXVAL should be the maximum value in the domain
4099 (one less than the length of the array).
4101 The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
4102 We don't enforce this limit, that is up to caller (e.g. language front end).
4103 The limit exists because the result is a signed type and we don't handle
4104 sizes that use more than one HOST_WIDE_INT. */
4107 build_index_type (maxval)
4110 register tree itype = make_node (INTEGER_TYPE);
4112 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
4113 TYPE_MIN_VALUE (itype) = size_zero_node;
4115 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4116 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
4119 TYPE_MODE (itype) = TYPE_MODE (sizetype);
4120 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
4121 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
4122 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
4123 if (TREE_CODE (maxval) == INTEGER_CST)
4125 int maxint = (int) TREE_INT_CST_LOW (maxval);
4126 /* If the domain should be empty, make sure the maxval
4127 remains -1 and is not spoiled by truncation. */
4128 if (INT_CST_LT (maxval, integer_zero_node))
4130 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
4131 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
4133 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4139 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
4140 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
4141 low bound LOWVAL and high bound HIGHVAL.
4142 if TYPE==NULL_TREE, sizetype is used. */
4145 build_range_type (type, lowval, highval)
4146 tree type, lowval, highval;
4148 register tree itype = make_node (INTEGER_TYPE);
4150 TREE_TYPE (itype) = type;
4151 if (type == NULL_TREE)
4154 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4155 TYPE_MIN_VALUE (itype) = convert (type, lowval);
4156 TYPE_MAX_VALUE (itype) = highval ? convert (type, highval) : NULL;
4159 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
4160 TYPE_MODE (itype) = TYPE_MODE (type);
4161 TYPE_SIZE (itype) = TYPE_SIZE (type);
4162 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
4163 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
4164 if (TREE_CODE (lowval) == INTEGER_CST)
4166 HOST_WIDE_INT lowint, highint;
4169 lowint = TREE_INT_CST_LOW (lowval);
4170 if (highval && TREE_CODE (highval) == INTEGER_CST)
4171 highint = TREE_INT_CST_LOW (highval);
4173 highint = (~(unsigned HOST_WIDE_INT)0) >> 1;
4175 maxint = (int) (highint - lowint);
4176 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4182 /* Just like build_index_type, but takes lowval and highval instead
4183 of just highval (maxval). */
4186 build_index_2_type (lowval,highval)
4187 tree lowval, highval;
4189 return build_range_type (NULL_TREE, lowval, highval);
4192 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
4193 Needed because when index types are not hashed, equal index types
4194 built at different times appear distinct, even though structurally,
4198 index_type_equal (itype1, itype2)
4199 tree itype1, itype2;
4201 if (TREE_CODE (itype1) != TREE_CODE (itype2))
4203 if (TREE_CODE (itype1) == INTEGER_TYPE)
4205 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
4206 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
4207 || simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2)) != 1
4208 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
4210 if (1 == simple_cst_equal (TYPE_MIN_VALUE (itype1),
4211 TYPE_MIN_VALUE (itype2))
4212 && 1 == simple_cst_equal (TYPE_MAX_VALUE (itype1),
4213 TYPE_MAX_VALUE (itype2)))
4220 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
4221 and number of elements specified by the range of values of INDEX_TYPE.
4222 If such a type has already been constructed, reuse it. */
4225 build_array_type (elt_type, index_type)
4226 tree elt_type, index_type;
4231 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
4233 error ("arrays of functions are not meaningful");
4234 elt_type = integer_type_node;
4237 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
4238 build_pointer_type (elt_type);
4240 /* Allocate the array after the pointer type,
4241 in case we free it in type_hash_canon. */
4242 t = make_node (ARRAY_TYPE);
4243 TREE_TYPE (t) = elt_type;
4244 TYPE_DOMAIN (t) = index_type;
4246 if (index_type == 0)
4251 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
4252 t = type_hash_canon (hashcode, t);
4254 if (TYPE_SIZE (t) == 0)
4259 /* Return the TYPE of the elements comprising
4260 the innermost dimension of ARRAY. */
4263 get_inner_array_type (array)
4266 tree type = TREE_TYPE (array);
4268 while (TREE_CODE (type) == ARRAY_TYPE)
4269 type = TREE_TYPE (type);
4274 /* Construct, lay out and return
4275 the type of functions returning type VALUE_TYPE
4276 given arguments of types ARG_TYPES.
4277 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
4278 are data type nodes for the arguments of the function.
4279 If such a type has already been constructed, reuse it. */
4282 build_function_type (value_type, arg_types)
4283 tree value_type, arg_types;
4288 if (TREE_CODE (value_type) == FUNCTION_TYPE)
4290 error ("function return type cannot be function");
4291 value_type = integer_type_node;
4294 /* Make a node of the sort we want. */
4295 t = make_node (FUNCTION_TYPE);
4296 TREE_TYPE (t) = value_type;
4297 TYPE_ARG_TYPES (t) = arg_types;
4299 /* If we already have such a type, use the old one and free this one. */
4300 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
4301 t = type_hash_canon (hashcode, t);
4303 if (TYPE_SIZE (t) == 0)
4308 /* Build the node for the type of references-to-TO_TYPE. */
4311 build_reference_type (to_type)
4314 register tree t = TYPE_REFERENCE_TO (to_type);
4316 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4321 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4322 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4323 t = make_node (REFERENCE_TYPE);
4326 TREE_TYPE (t) = to_type;
4328 /* Record this type as the pointer to TO_TYPE. */
4329 TYPE_REFERENCE_TO (to_type) = t;
4336 /* Construct, lay out and return the type of methods belonging to class
4337 BASETYPE and whose arguments and values are described by TYPE.
4338 If that type exists already, reuse it.
4339 TYPE must be a FUNCTION_TYPE node. */
4342 build_method_type (basetype, type)
4343 tree basetype, type;
4348 /* Make a node of the sort we want. */
4349 t = make_node (METHOD_TYPE);
4351 if (TREE_CODE (type) != FUNCTION_TYPE)
4354 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4355 TREE_TYPE (t) = TREE_TYPE (type);
4357 /* The actual arglist for this function includes a "hidden" argument
4358 which is "this". Put it into the list of argument types. */
4361 = tree_cons (NULL_TREE,
4362 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
4364 /* If we already have such a type, use the old one and free this one. */
4365 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4366 t = type_hash_canon (hashcode, t);
4368 if (TYPE_SIZE (t) == 0)
4374 /* Construct, lay out and return the type of offsets to a value
4375 of type TYPE, within an object of type BASETYPE.
4376 If a suitable offset type exists already, reuse it. */
4379 build_offset_type (basetype, type)
4380 tree basetype, type;
4385 /* Make a node of the sort we want. */
4386 t = make_node (OFFSET_TYPE);
4388 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4389 TREE_TYPE (t) = type;
4391 /* If we already have such a type, use the old one and free this one. */
4392 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4393 t = type_hash_canon (hashcode, t);
4395 if (TYPE_SIZE (t) == 0)
4401 /* Create a complex type whose components are COMPONENT_TYPE. */
4404 build_complex_type (component_type)
4405 tree component_type;
4410 /* Make a node of the sort we want. */
4411 t = make_node (COMPLEX_TYPE);
4413 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
4414 set_type_quals (t, TYPE_QUALS (component_type));
4416 /* If we already have such a type, use the old one and free this one. */
4417 hashcode = TYPE_HASH (component_type);
4418 t = type_hash_canon (hashcode, t);
4420 if (TYPE_SIZE (t) == 0)
4426 /* Return OP, stripped of any conversions to wider types as much as is safe.
4427 Converting the value back to OP's type makes a value equivalent to OP.
4429 If FOR_TYPE is nonzero, we return a value which, if converted to
4430 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
4432 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
4433 narrowest type that can hold the value, even if they don't exactly fit.
4434 Otherwise, bit-field references are changed to a narrower type
4435 only if they can be fetched directly from memory in that type.
4437 OP must have integer, real or enumeral type. Pointers are not allowed!
4439 There are some cases where the obvious value we could return
4440 would regenerate to OP if converted to OP's type,
4441 but would not extend like OP to wider types.
4442 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
4443 For example, if OP is (unsigned short)(signed char)-1,
4444 we avoid returning (signed char)-1 if FOR_TYPE is int,
4445 even though extending that to an unsigned short would regenerate OP,
4446 since the result of extending (signed char)-1 to (int)
4447 is different from (int) OP. */
4450 get_unwidened (op, for_type)
4454 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
4455 register tree type = TREE_TYPE (op);
4456 register unsigned final_prec
4457 = TYPE_PRECISION (for_type != 0 ? for_type : type);
4459 = (for_type != 0 && for_type != type
4460 && final_prec > TYPE_PRECISION (type)
4461 && TREE_UNSIGNED (type));
4462 register tree win = op;
4464 while (TREE_CODE (op) == NOP_EXPR)
4466 register int bitschange
4467 = TYPE_PRECISION (TREE_TYPE (op))
4468 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4470 /* Truncations are many-one so cannot be removed.
4471 Unless we are later going to truncate down even farther. */
4473 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
4476 /* See what's inside this conversion. If we decide to strip it,
4478 op = TREE_OPERAND (op, 0);
4480 /* If we have not stripped any zero-extensions (uns is 0),
4481 we can strip any kind of extension.
4482 If we have previously stripped a zero-extension,
4483 only zero-extensions can safely be stripped.
4484 Any extension can be stripped if the bits it would produce
4485 are all going to be discarded later by truncating to FOR_TYPE. */
4489 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
4491 /* TREE_UNSIGNED says whether this is a zero-extension.
4492 Let's avoid computing it if it does not affect WIN
4493 and if UNS will not be needed again. */
4494 if ((uns || TREE_CODE (op) == NOP_EXPR)
4495 && TREE_UNSIGNED (TREE_TYPE (op)))
4503 if (TREE_CODE (op) == COMPONENT_REF
4504 /* Since type_for_size always gives an integer type. */
4505 && TREE_CODE (type) != REAL_TYPE
4506 /* Don't crash if field not laid out yet. */
4507 && DECL_SIZE (TREE_OPERAND (op, 1)) != 0)
4509 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4510 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
4512 /* We can get this structure field in the narrowest type it fits in.
4513 If FOR_TYPE is 0, do this only for a field that matches the
4514 narrower type exactly and is aligned for it
4515 The resulting extension to its nominal type (a fullword type)
4516 must fit the same conditions as for other extensions. */
4518 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4519 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
4520 && (! uns || final_prec <= innerprec
4521 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4524 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4525 TREE_OPERAND (op, 1));
4526 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4527 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4528 TREE_RAISES (win) = TREE_RAISES (op);
4534 /* Return OP or a simpler expression for a narrower value
4535 which can be sign-extended or zero-extended to give back OP.
4536 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
4537 or 0 if the value should be sign-extended. */
4540 get_narrower (op, unsignedp_ptr)
4544 register int uns = 0;
4546 register tree win = op;
4548 while (TREE_CODE (op) == NOP_EXPR)
4550 register int bitschange
4551 = TYPE_PRECISION (TREE_TYPE (op))
4552 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4554 /* Truncations are many-one so cannot be removed. */
4558 /* See what's inside this conversion. If we decide to strip it,
4560 op = TREE_OPERAND (op, 0);
4564 /* An extension: the outermost one can be stripped,
4565 but remember whether it is zero or sign extension. */
4567 uns = TREE_UNSIGNED (TREE_TYPE (op));
4568 /* Otherwise, if a sign extension has been stripped,
4569 only sign extensions can now be stripped;
4570 if a zero extension has been stripped, only zero-extensions. */
4571 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
4575 else /* bitschange == 0 */
4577 /* A change in nominal type can always be stripped, but we must
4578 preserve the unsignedness. */
4580 uns = TREE_UNSIGNED (TREE_TYPE (op));
4587 if (TREE_CODE (op) == COMPONENT_REF
4588 /* Since type_for_size always gives an integer type. */
4589 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
4591 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4592 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
4594 /* We can get this structure field in a narrower type that fits it,
4595 but the resulting extension to its nominal type (a fullword type)
4596 must satisfy the same conditions as for other extensions.
4598 Do this only for fields that are aligned (not bit-fields),
4599 because when bit-field insns will be used there is no
4600 advantage in doing this. */
4602 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4603 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
4604 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4608 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
4609 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4610 TREE_OPERAND (op, 1));
4611 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4612 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4613 TREE_RAISES (win) = TREE_RAISES (op);
4616 *unsignedp_ptr = uns;
4620 /* Nonzero if integer constant C has a value that is permissible
4621 for type TYPE (an INTEGER_TYPE). */
4624 int_fits_type_p (c, type)
4627 if (TREE_UNSIGNED (type))
4628 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4629 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
4630 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4631 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
4632 /* Negative ints never fit unsigned types. */
4633 && ! (TREE_INT_CST_HIGH (c) < 0
4634 && ! TREE_UNSIGNED (TREE_TYPE (c))));
4636 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4637 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
4638 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4639 && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
4640 /* Unsigned ints with top bit set never fit signed types. */
4641 && ! (TREE_INT_CST_HIGH (c) < 0
4642 && TREE_UNSIGNED (TREE_TYPE (c))));
4645 /* Return the innermost context enclosing DECL that is
4646 a FUNCTION_DECL, or zero if none. */
4649 decl_function_context (decl)
4654 if (TREE_CODE (decl) == ERROR_MARK)
4657 if (TREE_CODE (decl) == SAVE_EXPR)
4658 context = SAVE_EXPR_CONTEXT (decl);
4660 context = DECL_CONTEXT (decl);
4662 while (context && TREE_CODE (context) != FUNCTION_DECL)
4664 if (TREE_CODE_CLASS (TREE_CODE (context)) == 't')
4665 context = TYPE_CONTEXT (context);
4666 else if (TREE_CODE_CLASS (TREE_CODE (context)) == 'd')
4667 context = DECL_CONTEXT (context);
4668 else if (TREE_CODE (context) == BLOCK)
4669 context = BLOCK_SUPERCONTEXT (context);
4671 /* Unhandled CONTEXT !? */
4678 /* Return the innermost context enclosing DECL that is
4679 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
4680 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
4683 decl_type_context (decl)
4686 tree context = DECL_CONTEXT (decl);
4690 if (TREE_CODE (context) == RECORD_TYPE
4691 || TREE_CODE (context) == UNION_TYPE
4692 || TREE_CODE (context) == QUAL_UNION_TYPE)
4694 if (TREE_CODE (context) == TYPE_DECL
4695 || TREE_CODE (context) == FUNCTION_DECL)
4696 context = DECL_CONTEXT (context);
4697 else if (TREE_CODE (context) == BLOCK)
4698 context = BLOCK_SUPERCONTEXT (context);
4700 /* Unhandled CONTEXT!? */
4706 /* Print debugging information about the size of the
4707 toplev_inline_obstacks. */
4710 print_inline_obstack_statistics ()
4712 struct simple_obstack_stack *current = toplev_inline_obstacks;
4717 for (; current; current = current->next, ++n_obstacks)
4719 struct obstack *o = current->obstack;
4720 struct _obstack_chunk *chunk = o->chunk;
4722 n_alloc += o->next_free - chunk->contents;
4723 chunk = chunk->prev;
4725 for (; chunk; chunk = chunk->prev, ++n_chunks)
4726 n_alloc += chunk->limit - &chunk->contents[0];
4728 fprintf (stderr, "inline obstacks: %d obstacks, %d bytes, %d chunks\n",
4729 n_obstacks, n_alloc, n_chunks);
4732 /* Print debugging information about the obstack O, named STR. */
4735 print_obstack_statistics (str, o)
4739 struct _obstack_chunk *chunk = o->chunk;
4743 n_alloc += o->next_free - chunk->contents;
4744 chunk = chunk->prev;
4748 n_alloc += chunk->limit - &chunk->contents[0];
4749 chunk = chunk->prev;
4751 fprintf (stderr, "obstack %s: %u bytes, %d chunks\n",
4752 str, n_alloc, n_chunks);
4755 /* Print debugging information about tree nodes generated during the compile,
4756 and any language-specific information. */
4759 dump_tree_statistics ()
4761 #ifdef GATHER_STATISTICS
4763 int total_nodes, total_bytes;
4766 fprintf (stderr, "\n??? tree nodes created\n\n");
4767 #ifdef GATHER_STATISTICS
4768 fprintf (stderr, "Kind Nodes Bytes\n");
4769 fprintf (stderr, "-------------------------------------\n");
4770 total_nodes = total_bytes = 0;
4771 for (i = 0; i < (int) all_kinds; i++)
4773 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
4774 tree_node_counts[i], tree_node_sizes[i]);
4775 total_nodes += tree_node_counts[i];
4776 total_bytes += tree_node_sizes[i];
4778 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
4779 fprintf (stderr, "-------------------------------------\n");
4780 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
4781 fprintf (stderr, "-------------------------------------\n");
4783 fprintf (stderr, "(No per-node statistics)\n");
4785 print_obstack_statistics ("permanent_obstack", &permanent_obstack);
4786 print_obstack_statistics ("maybepermanent_obstack", &maybepermanent_obstack);
4787 print_obstack_statistics ("temporary_obstack", &temporary_obstack);
4788 print_obstack_statistics ("momentary_obstack", &momentary_obstack);
4789 print_obstack_statistics ("temp_decl_obstack", &temp_decl_obstack);
4790 print_inline_obstack_statistics ();
4791 print_lang_statistics ();
4794 #define FILE_FUNCTION_PREFIX_LEN 9
4796 #ifndef NO_DOLLAR_IN_LABEL
4797 #define FILE_FUNCTION_FORMAT "_GLOBAL_$%s$%s"
4798 #else /* NO_DOLLAR_IN_LABEL */
4799 #ifndef NO_DOT_IN_LABEL
4800 #define FILE_FUNCTION_FORMAT "_GLOBAL_.%s.%s"
4801 #else /* NO_DOT_IN_LABEL */
4802 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
4803 #endif /* NO_DOT_IN_LABEL */
4804 #endif /* NO_DOLLAR_IN_LABEL */
4806 extern char * first_global_object_name;
4807 extern char * weak_global_object_name;
4809 /* Appends 6 random characters to TEMPLATE to (hopefully) avoid name
4810 clashes in cases where we can't reliably choose a unique name.
4812 Derived from mkstemp.c in libiberty. */
4815 append_random_chars (template)
4818 static const char letters[]
4819 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
4820 static unsigned HOST_WIDE_INT value;
4821 unsigned HOST_WIDE_INT v;
4823 #ifdef HAVE_GETTIMEOFDAY
4827 template += strlen (template);
4829 #ifdef HAVE_GETTIMEOFDAY
4830 /* Get some more or less random data. */
4831 gettimeofday (&tv, NULL);
4832 value += ((unsigned HOST_WIDE_INT) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();
4839 /* Fill in the random bits. */
4840 template[0] = letters[v % 62];
4842 template[1] = letters[v % 62];
4844 template[2] = letters[v % 62];
4846 template[3] = letters[v % 62];
4848 template[4] = letters[v % 62];
4850 template[5] = letters[v % 62];
4855 /* Generate a name for a function unique to this translation unit.
4856 TYPE is some string to identify the purpose of this function to the
4857 linker or collect2. */
4860 get_file_function_name_long (type)
4866 if (first_global_object_name)
4867 p = first_global_object_name;
4870 /* We don't have anything that we know to be unique to this translation
4871 unit, so use what we do have and throw in some randomness. */
4873 const char *name = weak_global_object_name;
4874 const char *file = main_input_filename;
4879 file = input_filename;
4881 p = (char *) alloca (7 + strlen (name) + strlen (file));
4883 sprintf (p, "%s%s", name, file);
4884 append_random_chars (p);
4887 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)
4890 /* Set up the name of the file-level functions we may need. */
4891 /* Use a global object (which is already required to be unique over
4892 the program) rather than the file name (which imposes extra
4893 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
4894 sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
4896 /* Don't need to pull weird characters out of global names. */
4897 if (p != first_global_object_name)
4899 for (p = buf+11; *p; p++)
4900 if (! ((*p >= '0' && *p <= '9')
4901 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
4902 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
4906 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
4909 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
4912 || (*p >= 'A' && *p <= 'Z')
4913 || (*p >= 'a' && *p <= 'z')))
4917 return get_identifier (buf);
4920 /* If KIND=='I', return a suitable global initializer (constructor) name.
4921 If KIND=='D', return a suitable global clean-up (destructor) name. */
4924 get_file_function_name (kind)
4931 return get_file_function_name_long (p);
4935 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4936 The result is placed in BUFFER (which has length BIT_SIZE),
4937 with one bit in each char ('\000' or '\001').
4939 If the constructor is constant, NULL_TREE is returned.
4940 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4943 get_set_constructor_bits (init, buffer, bit_size)
4950 HOST_WIDE_INT domain_min
4951 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (init))));
4952 tree non_const_bits = NULL_TREE;
4953 for (i = 0; i < bit_size; i++)
4956 for (vals = TREE_OPERAND (init, 1);
4957 vals != NULL_TREE; vals = TREE_CHAIN (vals))
4959 if (TREE_CODE (TREE_VALUE (vals)) != INTEGER_CST
4960 || (TREE_PURPOSE (vals) != NULL_TREE
4961 && TREE_CODE (TREE_PURPOSE (vals)) != INTEGER_CST))
4963 = tree_cons (TREE_PURPOSE (vals), TREE_VALUE (vals), non_const_bits);
4964 else if (TREE_PURPOSE (vals) != NULL_TREE)
4966 /* Set a range of bits to ones. */
4967 HOST_WIDE_INT lo_index
4968 = TREE_INT_CST_LOW (TREE_PURPOSE (vals)) - domain_min;
4969 HOST_WIDE_INT hi_index
4970 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4971 if (lo_index < 0 || lo_index >= bit_size
4972 || hi_index < 0 || hi_index >= bit_size)
4974 for ( ; lo_index <= hi_index; lo_index++)
4975 buffer[lo_index] = 1;
4979 /* Set a single bit to one. */
4981 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4982 if (index < 0 || index >= bit_size)
4984 error ("invalid initializer for bit string");
4990 return non_const_bits;
4993 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4994 The result is placed in BUFFER (which is an array of bytes).
4995 If the constructor is constant, NULL_TREE is returned.
4996 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4999 get_set_constructor_bytes (init, buffer, wd_size)
5001 unsigned char *buffer;
5005 int set_word_size = BITS_PER_UNIT;
5006 int bit_size = wd_size * set_word_size;
5008 unsigned char *bytep = buffer;
5009 char *bit_buffer = (char *) alloca(bit_size);
5010 tree non_const_bits = get_set_constructor_bits (init, bit_buffer, bit_size);
5012 for (i = 0; i < wd_size; i++)
5015 for (i = 0; i < bit_size; i++)
5019 if (BYTES_BIG_ENDIAN)
5020 *bytep |= (1 << (set_word_size - 1 - bit_pos));
5022 *bytep |= 1 << bit_pos;
5025 if (bit_pos >= set_word_size)
5026 bit_pos = 0, bytep++;
5028 return non_const_bits;
5031 #ifdef ENABLE_CHECKING
5033 /* Complain if the tree code does not match the expected one.
5034 NODE is the tree node in question, CODE is the expected tree code,
5035 and FILE and LINE are the filename and line number, respectively,
5036 of the line on which the check was done. If NONFATAL is nonzero,
5037 don't abort if the reference is invalid; instead, return 0.
5038 If the reference is valid, return NODE. */
5041 tree_check (node, code, file, line, nofatal)
5043 enum tree_code code;
5048 if (TREE_CODE (node) == code)
5053 fatal ("%s:%d: Expect %s, have %s\n", file, line,
5054 tree_code_name[code], tree_code_name[TREE_CODE (node)]);
5057 /* Similar to above, except that we check for a class of tree
5058 code, given in CL. */
5061 tree_class_check (node, cl, file, line, nofatal)
5068 if (TREE_CODE_CLASS (TREE_CODE (node)) == cl)
5073 fatal ("%s:%d: Expect '%c', have '%s'\n", file, line,
5074 cl, tree_code_name[TREE_CODE (node)]);
5077 /* Likewise, but complain if the tree node is not an expression. */
5080 expr_check (node, ignored, file, line, nofatal)
5087 switch (TREE_CODE_CLASS (TREE_CODE (node)))
5101 fatal ("%s:%d: Expect expression, have '%s'\n", file, line,
5102 tree_code_name[TREE_CODE (node)]);
5109 /* Return the alias set for T, which may be either a type or an
5116 if (!flag_strict_aliasing || !lang_get_alias_set)
5117 /* If we're not doing any lanaguage-specific alias analysis, just
5118 assume everything aliases everything else. */
5121 return (*lang_get_alias_set) (t);
5124 /* Return a brand-new alias set. */
5129 static int last_alias_set;
5130 if (flag_strict_aliasing)
5131 return ++last_alias_set;