Use new tail-calling mechanism on ARM.
[official-gcc.git] / gcc / tree.c
blob9f68e60122ac8f4dec15ddb04b124a185b1a1a46
1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
10 any later version.
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
23 /* This file contains the low level primitives for operating on tree nodes,
24 including allocation, list operations, interning of identifiers,
25 construction of data type nodes and statement nodes,
26 and construction of type conversion nodes. It also contains
27 tables index by tree code that describe how to take apart
28 nodes of that code.
30 It is intended to be language-independent, but occasionally
31 calls language-dependent routines defined (for C) in typecheck.c.
33 The low-level allocation routines oballoc and permalloc
34 are used also for allocating many other kinds of objects
35 by all passes of the compiler. */
37 #include "config.h"
38 #include "system.h"
39 #include "flags.h"
40 #include "tree.h"
41 #include "tm_p.h"
42 #include "function.h"
43 #include "obstack.h"
44 #include "toplev.h"
45 #include "ggc.h"
46 #include "hashtab.h"
48 #define obstack_chunk_alloc xmalloc
49 #define obstack_chunk_free free
50 /* obstack.[ch] explicitly declined to prototype this. */
51 extern int _obstack_allocated_p PARAMS ((struct obstack *h, PTR obj));
53 static void unsave_expr_now_r PARAMS ((tree));
55 /* Tree nodes of permanent duration are allocated in this obstack.
56 They are the identifier nodes, and everything outside of
57 the bodies and parameters of function definitions. */
59 struct obstack permanent_obstack;
61 /* The initial RTL, and all ..._TYPE nodes, in a function
62 are allocated in this obstack. Usually they are freed at the
63 end of the function, but if the function is inline they are saved.
64 For top-level functions, this is maybepermanent_obstack.
65 Separate obstacks are made for nested functions. */
67 struct obstack *function_maybepermanent_obstack;
69 /* This is the function_maybepermanent_obstack for top-level functions. */
71 struct obstack maybepermanent_obstack;
73 /* The contents of the current function definition are allocated
74 in this obstack, and all are freed at the end of the function.
75 For top-level functions, this is temporary_obstack.
76 Separate obstacks are made for nested functions. */
78 struct obstack *function_obstack;
80 /* This is used for reading initializers of global variables. */
82 struct obstack temporary_obstack;
84 /* The tree nodes of an expression are allocated
85 in this obstack, and all are freed at the end of the expression. */
87 struct obstack momentary_obstack;
89 /* The tree nodes of a declarator are allocated
90 in this obstack, and all are freed when the declarator
91 has been parsed. */
93 static struct obstack temp_decl_obstack;
95 /* This points at either permanent_obstack
96 or the current function_maybepermanent_obstack. */
98 struct obstack *saveable_obstack;
100 /* This is same as saveable_obstack during parse and expansion phase;
101 it points to the current function's obstack during optimization.
102 This is the obstack to be used for creating rtl objects. */
104 struct obstack *rtl_obstack;
106 /* This points at either permanent_obstack or the current function_obstack. */
108 struct obstack *current_obstack;
110 /* This points at either permanent_obstack or the current function_obstack
111 or momentary_obstack. */
113 struct obstack *expression_obstack;
115 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
117 struct obstack_stack
119 struct obstack_stack *next;
120 struct obstack *current;
121 struct obstack *saveable;
122 struct obstack *expression;
123 struct obstack *rtl;
126 struct obstack_stack *obstack_stack;
128 /* Obstack for allocating struct obstack_stack entries. */
130 static struct obstack obstack_stack_obstack;
132 /* Addresses of first objects in some obstacks.
133 This is for freeing their entire contents. */
134 char *maybepermanent_firstobj;
135 char *temporary_firstobj;
136 char *momentary_firstobj;
137 char *temp_decl_firstobj;
139 /* This is used to preserve objects (mainly array initializers) that need to
140 live until the end of the current function, but no further. */
141 char *momentary_function_firstobj;
143 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
145 int all_types_permanent;
147 /* Stack of places to restore the momentary obstack back to. */
149 struct momentary_level
151 /* Pointer back to previous such level. */
152 struct momentary_level *prev;
153 /* First object allocated within this level. */
154 char *base;
155 /* Value of expression_obstack saved at entry to this level. */
156 struct obstack *obstack;
159 struct momentary_level *momentary_stack;
161 /* Table indexed by tree code giving a string containing a character
162 classifying the tree code. Possibilities are
163 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
165 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
167 char tree_code_type[MAX_TREE_CODES] = {
168 #include "tree.def"
170 #undef DEFTREECODE
172 /* Table indexed by tree code giving number of expression
173 operands beyond the fixed part of the node structure.
174 Not used for types or decls. */
176 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
178 int tree_code_length[MAX_TREE_CODES] = {
179 #include "tree.def"
181 #undef DEFTREECODE
183 /* Names of tree components.
184 Used for printing out the tree and error messages. */
185 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
187 const char *tree_code_name[MAX_TREE_CODES] = {
188 #include "tree.def"
190 #undef DEFTREECODE
192 /* Statistics-gathering stuff. */
193 typedef enum
195 d_kind,
196 t_kind,
197 b_kind,
198 s_kind,
199 r_kind,
200 e_kind,
201 c_kind,
202 id_kind,
203 op_id_kind,
204 perm_list_kind,
205 temp_list_kind,
206 vec_kind,
207 x_kind,
208 lang_decl,
209 lang_type,
210 all_kinds
211 } tree_node_kind;
213 int tree_node_counts[(int)all_kinds];
214 int tree_node_sizes[(int)all_kinds];
215 int id_string_size = 0;
217 static const char * const tree_node_kind_names[] = {
218 "decls",
219 "types",
220 "blocks",
221 "stmts",
222 "refs",
223 "exprs",
224 "constants",
225 "identifiers",
226 "op_identifiers",
227 "perm_tree_lists",
228 "temp_tree_lists",
229 "vecs",
230 "random kinds",
231 "lang_decl kinds",
232 "lang_type kinds"
235 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
237 #define MAX_HASH_TABLE 1009
238 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
240 /* 0 while creating built-in identifiers. */
241 static int do_identifier_warnings;
243 /* Unique id for next decl created. */
244 static int next_decl_uid;
245 /* Unique id for next type created. */
246 static int next_type_uid = 1;
248 /* The language-specific function for alias analysis. If NULL, the
249 language does not do any special alias analysis. */
250 int (*lang_get_alias_set) PARAMS ((tree));
252 /* Here is how primitive or already-canonicalized types' hash
253 codes are made. */
254 #define TYPE_HASH(TYPE) ((unsigned long) (TYPE) & 0777777)
256 /* Since we cannot rehash a type after it is in the table, we have to
257 keep the hash code. */
259 struct type_hash
261 unsigned long hash;
262 tree type;
265 /* Initial size of the hash table (rounded to next prime). */
266 #define TYPE_HASH_INITIAL_SIZE 1000
268 /* Now here is the hash table. When recording a type, it is added to
269 the slot whose index is the hash code. Note that the hash table is
270 used for several kinds of types (function types, array types and
271 array index range types, for now). While all these live in the
272 same table, they are completely independent, and the hash code is
273 computed differently for each of these. */
275 htab_t type_hash_table;
277 static void build_real_from_int_cst_1 PARAMS ((PTR));
278 static void set_type_quals PARAMS ((tree, int));
279 static void append_random_chars PARAMS ((char *));
280 static void mark_type_hash PARAMS ((void *));
281 static int type_hash_eq PARAMS ((const void*, const void*));
282 static unsigned int type_hash_hash PARAMS ((const void*));
283 static void print_type_hash_statistics PARAMS((void));
284 static int mark_hash_entry PARAMS((void **, void *));
286 /* If non-null, these are language-specific helper functions for
287 unsave_expr_now. If present, LANG_UNSAVE is called before its
288 argument (an UNSAVE_EXPR) is to be unsaved, and all other
289 processing in unsave_expr_now is aborted. LANG_UNSAVE_EXPR_NOW is
290 called from unsave_expr_1 for language-specific tree codes. */
291 void (*lang_unsave) PARAMS ((tree *));
292 void (*lang_unsave_expr_now) PARAMS ((tree));
294 /* The string used as a placeholder instead of a source file name for
295 built-in tree nodes. The variable, which is dynamically allocated,
296 should be used; the macro is only used to initialize it. */
298 static char *built_in_filename;
299 #define BUILT_IN_FILENAME ("<built-in>")
301 tree global_trees[TI_MAX];
302 tree integer_types[itk_none];
304 /* Init the principal obstacks. */
306 void
307 init_obstacks ()
309 gcc_obstack_init (&obstack_stack_obstack);
310 gcc_obstack_init (&permanent_obstack);
312 gcc_obstack_init (&temporary_obstack);
313 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
314 gcc_obstack_init (&momentary_obstack);
315 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
316 momentary_function_firstobj = momentary_firstobj;
317 gcc_obstack_init (&maybepermanent_obstack);
318 maybepermanent_firstobj
319 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
320 gcc_obstack_init (&temp_decl_obstack);
321 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
323 function_obstack = &temporary_obstack;
324 function_maybepermanent_obstack = &maybepermanent_obstack;
325 current_obstack = &permanent_obstack;
326 expression_obstack = &permanent_obstack;
327 rtl_obstack = saveable_obstack = &permanent_obstack;
329 /* Init the hash table of identifiers. */
330 bzero ((char *) hash_table, sizeof hash_table);
331 ggc_add_tree_root (hash_table, sizeof hash_table / sizeof (tree));
333 /* Initialize the hash table of types. */
334 type_hash_table = htab_create (TYPE_HASH_INITIAL_SIZE, type_hash_hash,
335 type_hash_eq, 0);
336 ggc_add_root (&type_hash_table, 1, sizeof type_hash_table, mark_type_hash);
337 ggc_add_tree_root (global_trees, TI_MAX);
338 ggc_add_tree_root (integer_types, itk_none);
341 void
342 gcc_obstack_init (obstack)
343 struct obstack *obstack;
345 /* Let particular systems override the size of a chunk. */
346 #ifndef OBSTACK_CHUNK_SIZE
347 #define OBSTACK_CHUNK_SIZE 0
348 #endif
349 /* Let them override the alloc and free routines too. */
350 #ifndef OBSTACK_CHUNK_ALLOC
351 #define OBSTACK_CHUNK_ALLOC xmalloc
352 #endif
353 #ifndef OBSTACK_CHUNK_FREE
354 #define OBSTACK_CHUNK_FREE free
355 #endif
356 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
357 (void *(*) PARAMS ((long))) OBSTACK_CHUNK_ALLOC,
358 (void (*) PARAMS ((void *))) OBSTACK_CHUNK_FREE);
361 /* Save all variables describing the current status into the structure
362 *P. This function is called whenever we start compiling one
363 function in the midst of compiling another. For example, when
364 compiling a nested function, or, in C++, a template instantiation
365 that is required by the function we are currently compiling.
367 CONTEXT is the decl_function_context for the function we're about to
368 compile; if it isn't current_function_decl, we have to play some games. */
370 void
371 save_tree_status (p)
372 struct function *p;
374 p->all_types_permanent = all_types_permanent;
375 p->momentary_stack = momentary_stack;
376 p->maybepermanent_firstobj = maybepermanent_firstobj;
377 p->temporary_firstobj = temporary_firstobj;
378 p->momentary_firstobj = momentary_firstobj;
379 p->momentary_function_firstobj = momentary_function_firstobj;
380 p->function_obstack = function_obstack;
381 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
382 p->current_obstack = current_obstack;
383 p->expression_obstack = expression_obstack;
384 p->saveable_obstack = saveable_obstack;
385 p->rtl_obstack = rtl_obstack;
387 function_maybepermanent_obstack
388 = (struct obstack *) xmalloc (sizeof (struct obstack));
389 gcc_obstack_init (function_maybepermanent_obstack);
390 maybepermanent_firstobj
391 = (char *) obstack_finish (function_maybepermanent_obstack);
393 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
394 gcc_obstack_init (function_obstack);
396 current_obstack = &permanent_obstack;
397 expression_obstack = &permanent_obstack;
398 rtl_obstack = saveable_obstack = &permanent_obstack;
400 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
401 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
402 momentary_function_firstobj = momentary_firstobj;
405 /* Restore all variables describing the current status from the structure *P.
406 This is used after a nested function. */
408 void
409 restore_tree_status (p)
410 struct function *p;
412 all_types_permanent = p->all_types_permanent;
413 momentary_stack = p->momentary_stack;
415 obstack_free (&momentary_obstack, momentary_function_firstobj);
417 /* Free saveable storage used by the function just compiled and not
418 saved. */
419 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
420 if (obstack_empty_p (function_maybepermanent_obstack))
422 obstack_free (function_maybepermanent_obstack, NULL);
423 free (function_maybepermanent_obstack);
426 obstack_free (&temporary_obstack, temporary_firstobj);
427 obstack_free (&momentary_obstack, momentary_function_firstobj);
429 obstack_free (function_obstack, NULL);
430 free (function_obstack);
432 temporary_firstobj = p->temporary_firstobj;
433 momentary_firstobj = p->momentary_firstobj;
434 momentary_function_firstobj = p->momentary_function_firstobj;
435 maybepermanent_firstobj = p->maybepermanent_firstobj;
436 function_obstack = p->function_obstack;
437 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
438 current_obstack = p->current_obstack;
439 expression_obstack = p->expression_obstack;
440 saveable_obstack = p->saveable_obstack;
441 rtl_obstack = p->rtl_obstack;
444 /* Start allocating on the temporary (per function) obstack.
445 This is done in start_function before parsing the function body,
446 and before each initialization at top level, and to go back
447 to temporary allocation after doing permanent_allocation. */
449 void
450 temporary_allocation ()
452 /* Note that function_obstack at top level points to temporary_obstack.
453 But within a nested function context, it is a separate obstack. */
454 current_obstack = function_obstack;
455 expression_obstack = function_obstack;
456 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
457 momentary_stack = 0;
460 /* Start allocating on the permanent obstack but don't
461 free the temporary data. After calling this, call
462 `permanent_allocation' to fully resume permanent allocation status. */
464 void
465 end_temporary_allocation ()
467 current_obstack = &permanent_obstack;
468 expression_obstack = &permanent_obstack;
469 rtl_obstack = saveable_obstack = &permanent_obstack;
472 /* Resume allocating on the temporary obstack, undoing
473 effects of `end_temporary_allocation'. */
475 void
476 resume_temporary_allocation ()
478 current_obstack = function_obstack;
479 expression_obstack = function_obstack;
480 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
483 /* While doing temporary allocation, switch to allocating in such a
484 way as to save all nodes if the function is inlined. Call
485 resume_temporary_allocation to go back to ordinary temporary
486 allocation. */
488 void
489 saveable_allocation ()
491 /* Note that function_obstack at top level points to temporary_obstack.
492 But within a nested function context, it is a separate obstack. */
493 expression_obstack = current_obstack = saveable_obstack;
496 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
497 recording the previously current obstacks on a stack.
498 This does not free any storage in any obstack. */
500 void
501 push_obstacks (current, saveable)
502 struct obstack *current, *saveable;
504 struct obstack_stack *p;
506 p = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
507 (sizeof (struct obstack_stack)));
509 p->current = current_obstack;
510 p->saveable = saveable_obstack;
511 p->expression = expression_obstack;
512 p->rtl = rtl_obstack;
513 p->next = obstack_stack;
514 obstack_stack = p;
516 current_obstack = current;
517 expression_obstack = current;
518 rtl_obstack = saveable_obstack = saveable;
521 /* Save the current set of obstacks, but don't change them. */
523 void
524 push_obstacks_nochange ()
526 struct obstack_stack *p;
528 p = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
529 (sizeof (struct obstack_stack)));
531 p->current = current_obstack;
532 p->saveable = saveable_obstack;
533 p->expression = expression_obstack;
534 p->rtl = rtl_obstack;
535 p->next = obstack_stack;
536 obstack_stack = p;
539 /* Pop the obstack selection stack. */
541 void
542 pop_obstacks ()
544 struct obstack_stack *p;
546 p = obstack_stack;
547 obstack_stack = p->next;
549 current_obstack = p->current;
550 saveable_obstack = p->saveable;
551 expression_obstack = p->expression;
552 rtl_obstack = p->rtl;
554 obstack_free (&obstack_stack_obstack, p);
557 /* Nonzero if temporary allocation is currently in effect.
558 Zero if currently doing permanent allocation. */
561 allocation_temporary_p ()
563 return current_obstack != &permanent_obstack;
566 /* Go back to allocating on the permanent obstack
567 and free everything in the temporary obstack.
569 FUNCTION_END is true only if we have just finished compiling a function.
570 In that case, we also free preserved initial values on the momentary
571 obstack. */
573 void
574 permanent_allocation (function_end)
575 int function_end;
577 /* Free up previous temporary obstack data */
578 obstack_free (&temporary_obstack, temporary_firstobj);
579 if (function_end)
581 obstack_free (&momentary_obstack, momentary_function_firstobj);
582 momentary_firstobj = momentary_function_firstobj;
584 else
585 obstack_free (&momentary_obstack, momentary_firstobj);
587 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
588 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
590 current_obstack = &permanent_obstack;
591 expression_obstack = &permanent_obstack;
592 rtl_obstack = saveable_obstack = &permanent_obstack;
595 /* Save permanently everything on the maybepermanent_obstack. */
597 void
598 preserve_data ()
600 maybepermanent_firstobj
601 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
604 void
605 preserve_initializer ()
607 struct momentary_level *tem;
608 char *old_momentary;
610 temporary_firstobj
611 = (char *) obstack_alloc (&temporary_obstack, 0);
612 maybepermanent_firstobj
613 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
615 old_momentary = momentary_firstobj;
616 momentary_firstobj
617 = (char *) obstack_alloc (&momentary_obstack, 0);
618 if (momentary_firstobj != old_momentary)
619 for (tem = momentary_stack; tem; tem = tem->prev)
620 tem->base = momentary_firstobj;
623 /* Start allocating new rtl in current_obstack.
624 Use resume_temporary_allocation
625 to go back to allocating rtl in saveable_obstack. */
627 void
628 rtl_in_current_obstack ()
630 rtl_obstack = current_obstack;
633 /* Start allocating rtl from saveable_obstack. Intended to be used after
634 a call to push_obstacks_nochange. */
636 void
637 rtl_in_saveable_obstack ()
639 rtl_obstack = saveable_obstack;
642 /* Allocate SIZE bytes in the current obstack
643 and return a pointer to them.
644 In practice the current obstack is always the temporary one. */
646 char *
647 oballoc (size)
648 int size;
650 return (char *) obstack_alloc (current_obstack, size);
653 /* Free the object PTR in the current obstack
654 as well as everything allocated since PTR.
655 In practice the current obstack is always the temporary one. */
657 void
658 obfree (ptr)
659 char *ptr;
661 obstack_free (current_obstack, ptr);
664 /* Allocate SIZE bytes in the permanent obstack
665 and return a pointer to them. */
667 char *
668 permalloc (size)
669 int size;
671 return (char *) obstack_alloc (&permanent_obstack, size);
674 /* Allocate NELEM items of SIZE bytes in the permanent obstack
675 and return a pointer to them. The storage is cleared before
676 returning the value. */
678 char *
679 perm_calloc (nelem, size)
680 int nelem;
681 long size;
683 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
684 bzero (rval, nelem * size);
685 return rval;
688 /* Allocate SIZE bytes in the saveable obstack
689 and return a pointer to them. */
691 char *
692 savealloc (size)
693 int size;
695 return (char *) obstack_alloc (saveable_obstack, size);
698 /* Allocate SIZE bytes in the expression obstack
699 and return a pointer to them. */
701 char *
702 expralloc (size)
703 int size;
705 return (char *) obstack_alloc (expression_obstack, size);
708 /* Print out which obstack an object is in. */
710 void
711 print_obstack_name (object, file, prefix)
712 char *object;
713 FILE *file;
714 const char *prefix;
716 struct obstack *obstack = NULL;
717 const char *obstack_name = NULL;
718 struct function *p;
720 for (p = outer_function_chain; p; p = p->next)
722 if (_obstack_allocated_p (p->function_obstack, object))
724 obstack = p->function_obstack;
725 obstack_name = "containing function obstack";
727 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
729 obstack = p->function_maybepermanent_obstack;
730 obstack_name = "containing function maybepermanent obstack";
734 if (_obstack_allocated_p (&obstack_stack_obstack, object))
736 obstack = &obstack_stack_obstack;
737 obstack_name = "obstack_stack_obstack";
739 else if (_obstack_allocated_p (function_obstack, object))
741 obstack = function_obstack;
742 obstack_name = "function obstack";
744 else if (_obstack_allocated_p (&permanent_obstack, object))
746 obstack = &permanent_obstack;
747 obstack_name = "permanent_obstack";
749 else if (_obstack_allocated_p (&momentary_obstack, object))
751 obstack = &momentary_obstack;
752 obstack_name = "momentary_obstack";
754 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
756 obstack = function_maybepermanent_obstack;
757 obstack_name = "function maybepermanent obstack";
759 else if (_obstack_allocated_p (&temp_decl_obstack, object))
761 obstack = &temp_decl_obstack;
762 obstack_name = "temp_decl_obstack";
765 /* Check to see if the object is in the free area of the obstack. */
766 if (obstack != NULL)
768 if (object >= obstack->next_free
769 && object < obstack->chunk_limit)
770 fprintf (file, "%s in free portion of obstack %s",
771 prefix, obstack_name);
772 else
773 fprintf (file, "%s allocated from %s", prefix, obstack_name);
775 else
776 fprintf (file, "%s not allocated from any obstack", prefix);
779 void
780 debug_obstack (object)
781 char *object;
783 print_obstack_name (object, stderr, "object");
784 fprintf (stderr, ".\n");
787 /* Return 1 if OBJ is in the permanent obstack.
788 This is slow, and should be used only for debugging.
789 Use TREE_PERMANENT for other purposes. */
792 object_permanent_p (obj)
793 tree obj;
795 return _obstack_allocated_p (&permanent_obstack, obj);
798 /* Start a level of momentary allocation.
799 In C, each compound statement has its own level
800 and that level is freed at the end of each statement.
801 All expression nodes are allocated in the momentary allocation level. */
803 void
804 push_momentary ()
806 struct momentary_level *tem
807 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
808 sizeof (struct momentary_level));
809 tem->prev = momentary_stack;
810 tem->base = (char *) obstack_base (&momentary_obstack);
811 tem->obstack = expression_obstack;
812 momentary_stack = tem;
813 expression_obstack = &momentary_obstack;
816 /* Set things up so the next clear_momentary will only clear memory
817 past our present position in momentary_obstack. */
819 void
820 preserve_momentary ()
822 momentary_stack->base = (char *) obstack_base (&momentary_obstack);
825 /* Free all the storage in the current momentary-allocation level.
826 In C, this happens at the end of each statement. */
828 void
829 clear_momentary ()
831 obstack_free (&momentary_obstack, momentary_stack->base);
834 /* Discard a level of momentary allocation.
835 In C, this happens at the end of each compound statement.
836 Restore the status of expression node allocation
837 that was in effect before this level was created. */
839 void
840 pop_momentary ()
842 struct momentary_level *tem = momentary_stack;
843 momentary_stack = tem->prev;
844 expression_obstack = tem->obstack;
845 /* We can't free TEM from the momentary_obstack, because there might
846 be objects above it which have been saved. We can free back to the
847 stack of the level we are popping off though. */
848 obstack_free (&momentary_obstack, tem->base);
851 /* Pop back to the previous level of momentary allocation,
852 but don't free any momentary data just yet. */
854 void
855 pop_momentary_nofree ()
857 struct momentary_level *tem = momentary_stack;
858 momentary_stack = tem->prev;
859 expression_obstack = tem->obstack;
862 /* Call when starting to parse a declaration:
863 make expressions in the declaration last the length of the function.
864 Returns an argument that should be passed to resume_momentary later. */
867 suspend_momentary ()
869 register int tem = expression_obstack == &momentary_obstack;
870 expression_obstack = saveable_obstack;
871 return tem;
874 /* Call when finished parsing a declaration:
875 restore the treatment of node-allocation that was
876 in effect before the suspension.
877 YES should be the value previously returned by suspend_momentary. */
879 void
880 resume_momentary (yes)
881 int yes;
883 if (yes)
884 expression_obstack = &momentary_obstack;
887 /* Init the tables indexed by tree code.
888 Note that languages can add to these tables to define their own codes. */
890 void
891 init_tree_codes ()
893 built_in_filename
894 = ggc_alloc_string (BUILT_IN_FILENAME, sizeof (BUILT_IN_FILENAME));
895 ggc_add_string_root (&built_in_filename, 1);
898 /* Return a newly allocated node of code CODE.
899 Initialize the node's unique id and its TREE_PERMANENT flag.
900 Note that if garbage collection is in use, TREE_PERMANENT will
901 always be zero - we want to eliminate use of TREE_PERMANENT.
902 For decl and type nodes, some other fields are initialized.
903 The rest of the node is initialized to zero.
905 Achoo! I got a code in the node. */
907 tree
908 make_node (code)
909 enum tree_code code;
911 register tree t;
912 register int type = TREE_CODE_CLASS (code);
913 register int length = 0;
914 register struct obstack *obstack = current_obstack;
915 #ifdef GATHER_STATISTICS
916 register tree_node_kind kind;
917 #endif
919 switch (type)
921 case 'd': /* A decl node */
922 #ifdef GATHER_STATISTICS
923 kind = d_kind;
924 #endif
925 length = sizeof (struct tree_decl);
926 /* All decls in an inline function need to be saved. */
927 if (obstack != &permanent_obstack)
928 obstack = saveable_obstack;
930 /* PARM_DECLs go on the context of the parent. If this is a nested
931 function, then we must allocate the PARM_DECL on the parent's
932 obstack, so that they will live to the end of the parent's
933 closing brace. This is necessary in case we try to inline the
934 function into its parent.
936 PARM_DECLs of top-level functions do not have this problem. However,
937 we allocate them where we put the FUNCTION_DECL for languages such as
938 Ada that need to consult some flags in the PARM_DECLs of the function
939 when calling it.
941 See comment in restore_tree_status for why we can't put this
942 in function_obstack. */
943 if (code == PARM_DECL && obstack != &permanent_obstack)
945 tree context = 0;
946 if (current_function_decl)
947 context = decl_function_context (current_function_decl);
949 if (context)
950 obstack
951 = find_function_data (context)->function_maybepermanent_obstack;
953 break;
955 case 't': /* a type node */
956 #ifdef GATHER_STATISTICS
957 kind = t_kind;
958 #endif
959 length = sizeof (struct tree_type);
960 /* All data types are put where we can preserve them if nec. */
961 if (obstack != &permanent_obstack)
962 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
963 break;
965 case 'b': /* a lexical block */
966 #ifdef GATHER_STATISTICS
967 kind = b_kind;
968 #endif
969 length = sizeof (struct tree_block);
970 /* All BLOCK nodes are put where we can preserve them if nec. */
971 if (obstack != &permanent_obstack)
972 obstack = saveable_obstack;
973 break;
975 case 's': /* an expression with side effects */
976 #ifdef GATHER_STATISTICS
977 kind = s_kind;
978 goto usual_kind;
979 #endif
980 case 'r': /* a reference */
981 #ifdef GATHER_STATISTICS
982 kind = r_kind;
983 goto usual_kind;
984 #endif
985 case 'e': /* an expression */
986 case '<': /* a comparison expression */
987 case '1': /* a unary arithmetic expression */
988 case '2': /* a binary arithmetic expression */
989 #ifdef GATHER_STATISTICS
990 kind = e_kind;
991 usual_kind:
992 #endif
993 obstack = expression_obstack;
994 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
995 if (code == BIND_EXPR && obstack != &permanent_obstack)
996 obstack = saveable_obstack;
997 length = sizeof (struct tree_exp)
998 + (tree_code_length[(int) code] - 1) * sizeof (char *);
999 break;
1001 case 'c': /* a constant */
1002 #ifdef GATHER_STATISTICS
1003 kind = c_kind;
1004 #endif
1005 obstack = expression_obstack;
1007 /* We can't use tree_code_length for INTEGER_CST, since the number of
1008 words is machine-dependent due to varying length of HOST_WIDE_INT,
1009 which might be wider than a pointer (e.g., long long). Similarly
1010 for REAL_CST, since the number of words is machine-dependent due
1011 to varying size and alignment of `double'. */
1013 if (code == INTEGER_CST)
1014 length = sizeof (struct tree_int_cst);
1015 else if (code == REAL_CST)
1016 length = sizeof (struct tree_real_cst);
1017 else
1018 length = sizeof (struct tree_common)
1019 + tree_code_length[(int) code] * sizeof (char *);
1020 break;
1022 case 'x': /* something random, like an identifier. */
1023 #ifdef GATHER_STATISTICS
1024 if (code == IDENTIFIER_NODE)
1025 kind = id_kind;
1026 else if (code == OP_IDENTIFIER)
1027 kind = op_id_kind;
1028 else if (code == TREE_VEC)
1029 kind = vec_kind;
1030 else
1031 kind = x_kind;
1032 #endif
1033 length = sizeof (struct tree_common)
1034 + tree_code_length[(int) code] * sizeof (char *);
1035 /* Identifier nodes are always permanent since they are
1036 unique in a compiler run. */
1037 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1038 break;
1040 default:
1041 abort ();
1044 if (ggc_p)
1045 t = ggc_alloc_tree (length);
1046 else
1048 t = (tree) obstack_alloc (obstack, length);
1049 memset ((PTR) t, 0, length);
1052 #ifdef GATHER_STATISTICS
1053 tree_node_counts[(int)kind]++;
1054 tree_node_sizes[(int)kind] += length;
1055 #endif
1057 TREE_SET_CODE (t, code);
1058 TREE_SET_PERMANENT (t);
1060 switch (type)
1062 case 's':
1063 TREE_SIDE_EFFECTS (t) = 1;
1064 TREE_TYPE (t) = void_type_node;
1065 break;
1067 case 'd':
1068 if (code != FUNCTION_DECL)
1069 DECL_ALIGN (t) = 1;
1070 DECL_IN_SYSTEM_HEADER (t) = in_system_header;
1071 DECL_SOURCE_LINE (t) = lineno;
1072 DECL_SOURCE_FILE (t) =
1073 (input_filename) ? input_filename : built_in_filename;
1074 DECL_UID (t) = next_decl_uid++;
1075 /* Note that we have not yet computed the alias set for this
1076 declaration. */
1077 DECL_POINTER_ALIAS_SET (t) = -1;
1078 break;
1080 case 't':
1081 TYPE_UID (t) = next_type_uid++;
1082 TYPE_ALIGN (t) = 1;
1083 TYPE_MAIN_VARIANT (t) = t;
1084 TYPE_OBSTACK (t) = obstack;
1085 TYPE_ATTRIBUTES (t) = NULL_TREE;
1086 #ifdef SET_DEFAULT_TYPE_ATTRIBUTES
1087 SET_DEFAULT_TYPE_ATTRIBUTES (t);
1088 #endif
1089 /* Note that we have not yet computed the alias set for this
1090 type. */
1091 TYPE_ALIAS_SET (t) = -1;
1092 break;
1094 case 'c':
1095 TREE_CONSTANT (t) = 1;
1096 break;
1098 case 'e':
1099 switch (code)
1101 case INIT_EXPR:
1102 case MODIFY_EXPR:
1103 case VA_ARG_EXPR:
1104 case RTL_EXPR:
1105 case PREDECREMENT_EXPR:
1106 case PREINCREMENT_EXPR:
1107 case POSTDECREMENT_EXPR:
1108 case POSTINCREMENT_EXPR:
1109 /* All of these have side-effects, no matter what their
1110 operands are. */
1111 TREE_SIDE_EFFECTS (t) = 1;
1112 break;
1114 default:
1115 break;
1117 break;
1120 return t;
1123 /* A front-end can reset this to an appropriate function if types need
1124 special handling. */
1126 tree (*make_lang_type_fn) PARAMS ((enum tree_code)) = make_node;
1128 /* Return a new type (with the indicated CODE), doing whatever
1129 language-specific processing is required. */
1131 tree
1132 make_lang_type (code)
1133 enum tree_code code;
1135 return (*make_lang_type_fn) (code);
1138 /* Return a new node with the same contents as NODE except that its
1139 TREE_CHAIN is zero and it has a fresh uid. Unlike make_node, this
1140 function always performs the allocation on the CURRENT_OBSTACK;
1141 it's up to the caller to pick the right obstack before calling this
1142 function. */
1144 tree
1145 copy_node (node)
1146 tree node;
1148 register tree t;
1149 register enum tree_code code = TREE_CODE (node);
1150 register int length = 0;
1152 switch (TREE_CODE_CLASS (code))
1154 case 'd': /* A decl node */
1155 length = sizeof (struct tree_decl);
1156 break;
1158 case 't': /* a type node */
1159 length = sizeof (struct tree_type);
1160 break;
1162 case 'b': /* a lexical block node */
1163 length = sizeof (struct tree_block);
1164 break;
1166 case 'r': /* a reference */
1167 case 'e': /* an expression */
1168 case 's': /* an expression with side effects */
1169 case '<': /* a comparison expression */
1170 case '1': /* a unary arithmetic expression */
1171 case '2': /* a binary arithmetic expression */
1172 length = sizeof (struct tree_exp)
1173 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1174 break;
1176 case 'c': /* a constant */
1177 /* We can't use tree_code_length for INTEGER_CST, since the number of
1178 words is machine-dependent due to varying length of HOST_WIDE_INT,
1179 which might be wider than a pointer (e.g., long long). Similarly
1180 for REAL_CST, since the number of words is machine-dependent due
1181 to varying size and alignment of `double'. */
1182 if (code == INTEGER_CST)
1183 length = sizeof (struct tree_int_cst);
1184 else if (code == REAL_CST)
1185 length = sizeof (struct tree_real_cst);
1186 else
1187 length = (sizeof (struct tree_common)
1188 + tree_code_length[(int) code] * sizeof (char *));
1189 break;
1191 case 'x': /* something random, like an identifier. */
1192 length = sizeof (struct tree_common)
1193 + tree_code_length[(int) code] * sizeof (char *);
1194 if (code == TREE_VEC)
1195 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1198 if (ggc_p)
1199 t = ggc_alloc_tree (length);
1200 else
1201 t = (tree) obstack_alloc (current_obstack, length);
1202 memcpy (t, node, length);
1204 TREE_CHAIN (t) = 0;
1205 TREE_ASM_WRITTEN (t) = 0;
1207 if (TREE_CODE_CLASS (code) == 'd')
1208 DECL_UID (t) = next_decl_uid++;
1209 else if (TREE_CODE_CLASS (code) == 't')
1211 TYPE_UID (t) = next_type_uid++;
1212 TYPE_OBSTACK (t) = current_obstack;
1214 /* The following is so that the debug code for
1215 the copy is different from the original type.
1216 The two statements usually duplicate each other
1217 (because they clear fields of the same union),
1218 but the optimizer should catch that. */
1219 TYPE_SYMTAB_POINTER (t) = 0;
1220 TYPE_SYMTAB_ADDRESS (t) = 0;
1223 TREE_SET_PERMANENT (t);
1225 return t;
1228 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1229 For example, this can copy a list made of TREE_LIST nodes. */
1231 tree
1232 copy_list (list)
1233 tree list;
1235 tree head;
1236 register tree prev, next;
1238 if (list == 0)
1239 return 0;
1241 head = prev = copy_node (list);
1242 next = TREE_CHAIN (list);
1243 while (next)
1245 TREE_CHAIN (prev) = copy_node (next);
1246 prev = TREE_CHAIN (prev);
1247 next = TREE_CHAIN (next);
1249 return head;
1252 #define HASHBITS 30
1254 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1255 If an identifier with that name has previously been referred to,
1256 the same node is returned this time. */
1258 tree
1259 get_identifier (text)
1260 register const char *text;
1262 register int hi;
1263 register int i;
1264 register tree idp;
1265 register int len, hash_len;
1267 /* Compute length of text in len. */
1268 len = strlen (text);
1270 /* Decide how much of that length to hash on */
1271 hash_len = len;
1272 if (warn_id_clash && len > id_clash_len)
1273 hash_len = id_clash_len;
1275 /* Compute hash code */
1276 hi = hash_len * 613 + (unsigned) text[0];
1277 for (i = 1; i < hash_len; i += 2)
1278 hi = ((hi * 613) + (unsigned) (text[i]));
1280 hi &= (1 << HASHBITS) - 1;
1281 hi %= MAX_HASH_TABLE;
1283 /* Search table for identifier */
1284 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1285 if (IDENTIFIER_LENGTH (idp) == len
1286 && IDENTIFIER_POINTER (idp)[0] == text[0]
1287 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1288 return idp; /* <-- return if found */
1290 /* Not found; optionally warn about a similar identifier */
1291 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1292 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1293 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1295 warning ("`%s' and `%s' identical in first %d characters",
1296 IDENTIFIER_POINTER (idp), text, id_clash_len);
1297 break;
1300 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1301 abort (); /* set_identifier_size hasn't been called. */
1303 /* Not found, create one, add to chain */
1304 idp = make_node (IDENTIFIER_NODE);
1305 IDENTIFIER_LENGTH (idp) = len;
1306 #ifdef GATHER_STATISTICS
1307 id_string_size += len;
1308 #endif
1310 if (ggc_p)
1311 IDENTIFIER_POINTER (idp) = ggc_alloc_string (text, len);
1312 else
1313 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1315 TREE_CHAIN (idp) = hash_table[hi];
1316 hash_table[hi] = idp;
1317 return idp; /* <-- return if created */
1320 /* If an identifier with the name TEXT (a null-terminated string) has
1321 previously been referred to, return that node; otherwise return
1322 NULL_TREE. */
1324 tree
1325 maybe_get_identifier (text)
1326 register const char *text;
1328 register int hi;
1329 register int i;
1330 register tree idp;
1331 register int len, hash_len;
1333 /* Compute length of text in len. */
1334 len = strlen (text);
1336 /* Decide how much of that length to hash on */
1337 hash_len = len;
1338 if (warn_id_clash && len > id_clash_len)
1339 hash_len = id_clash_len;
1341 /* Compute hash code */
1342 hi = hash_len * 613 + (unsigned) text[0];
1343 for (i = 1; i < hash_len; i += 2)
1344 hi = ((hi * 613) + (unsigned) (text[i]));
1346 hi &= (1 << HASHBITS) - 1;
1347 hi %= MAX_HASH_TABLE;
1349 /* Search table for identifier */
1350 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1351 if (IDENTIFIER_LENGTH (idp) == len
1352 && IDENTIFIER_POINTER (idp)[0] == text[0]
1353 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1354 return idp; /* <-- return if found */
1356 return NULL_TREE;
1359 /* Enable warnings on similar identifiers (if requested).
1360 Done after the built-in identifiers are created. */
1362 void
1363 start_identifier_warnings ()
1365 do_identifier_warnings = 1;
1368 /* Record the size of an identifier node for the language in use.
1369 SIZE is the total size in bytes.
1370 This is called by the language-specific files. This must be
1371 called before allocating any identifiers. */
1373 void
1374 set_identifier_size (size)
1375 int size;
1377 tree_code_length[(int) IDENTIFIER_NODE]
1378 = (size - sizeof (struct tree_common)) / sizeof (tree);
1381 /* Return a newly constructed INTEGER_CST node whose constant value
1382 is specified by the two ints LOW and HI.
1383 The TREE_TYPE is set to `int'.
1385 This function should be used via the `build_int_2' macro. */
1387 tree
1388 build_int_2_wide (low, hi)
1389 unsigned HOST_WIDE_INT low;
1390 HOST_WIDE_INT hi;
1392 register tree t = make_node (INTEGER_CST);
1394 TREE_INT_CST_LOW (t) = low;
1395 TREE_INT_CST_HIGH (t) = hi;
1396 TREE_TYPE (t) = integer_type_node;
1397 return t;
1400 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1402 tree
1403 build_real (type, d)
1404 tree type;
1405 REAL_VALUE_TYPE d;
1407 tree v;
1408 int overflow = 0;
1410 /* Check for valid float value for this type on this target machine;
1411 if not, can print error message and store a valid value in D. */
1412 #ifdef CHECK_FLOAT_VALUE
1413 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1414 #endif
1416 v = make_node (REAL_CST);
1417 TREE_TYPE (v) = type;
1418 TREE_REAL_CST (v) = d;
1419 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1420 return v;
1423 /* Return a new REAL_CST node whose type is TYPE
1424 and whose value is the integer value of the INTEGER_CST node I. */
1426 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1428 REAL_VALUE_TYPE
1429 real_value_from_int_cst (type, i)
1430 tree type ATTRIBUTE_UNUSED, i;
1432 REAL_VALUE_TYPE d;
1434 #ifdef REAL_ARITHMETIC
1435 /* Clear all bits of the real value type so that we can later do
1436 bitwise comparisons to see if two values are the same. */
1437 bzero ((char *) &d, sizeof d);
1439 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1440 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1441 TYPE_MODE (type));
1442 else
1443 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i),
1444 TREE_INT_CST_HIGH (i), TYPE_MODE (type));
1445 #else /* not REAL_ARITHMETIC */
1446 /* Some 386 compilers mishandle unsigned int to float conversions,
1447 so introduce a temporary variable E to avoid those bugs. */
1448 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1450 REAL_VALUE_TYPE e;
1452 d = (double) (~ TREE_INT_CST_HIGH (i));
1453 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1454 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1455 d *= e;
1456 e = (double) (~ TREE_INT_CST_LOW (i));
1457 d += e;
1458 d = (- d - 1.0);
1460 else
1462 REAL_VALUE_TYPE e;
1464 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1465 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1466 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1467 d *= e;
1468 e = (double) TREE_INT_CST_LOW (i);
1469 d += e;
1471 #endif /* not REAL_ARITHMETIC */
1472 return d;
1475 /* Args to pass to and from build_real_from_int_cst_1. */
1477 struct brfic_args
1479 tree type; /* Input: type to conver to. */
1480 tree i; /* Input: operand to convert */
1481 REAL_VALUE_TYPE d; /* Output: floating point value. */
1484 /* Convert an integer to a floating point value while protected by a floating
1485 point exception handler. */
1487 static void
1488 build_real_from_int_cst_1 (data)
1489 PTR data;
1491 struct brfic_args *args = (struct brfic_args *) data;
1493 #ifdef REAL_ARITHMETIC
1494 args->d = real_value_from_int_cst (args->type, args->i);
1495 #else
1496 args->d
1497 = REAL_VALUE_TRUNCATE (TYPE_MODE (args->type),
1498 real_value_from_int_cst (args->type, args->i));
1499 #endif
1502 /* Given a tree representing an integer constant I, return a tree
1503 representing the same value as a floating-point constant of type TYPE.
1504 We cannot perform this operation if there is no way of doing arithmetic
1505 on floating-point values. */
1507 tree
1508 build_real_from_int_cst (type, i)
1509 tree type;
1510 tree i;
1512 tree v;
1513 int overflow = TREE_OVERFLOW (i);
1514 REAL_VALUE_TYPE d;
1515 struct brfic_args args;
1517 v = make_node (REAL_CST);
1518 TREE_TYPE (v) = type;
1520 /* Setup input for build_real_from_int_cst_1() */
1521 args.type = type;
1522 args.i = i;
1524 if (do_float_handler (build_real_from_int_cst_1, (PTR) &args))
1525 /* Receive output from build_real_from_int_cst_1() */
1526 d = args.d;
1527 else
1529 /* We got an exception from build_real_from_int_cst_1() */
1530 d = dconst0;
1531 overflow = 1;
1534 /* Check for valid float value for this type on this target machine. */
1536 #ifdef CHECK_FLOAT_VALUE
1537 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1538 #endif
1540 TREE_REAL_CST (v) = d;
1541 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1542 return v;
1545 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1547 /* Return a newly constructed STRING_CST node whose value is
1548 the LEN characters at STR.
1549 The TREE_TYPE is not initialized. */
1551 tree
1552 build_string (len, str)
1553 int len;
1554 const char *str;
1556 /* Put the string in saveable_obstack since it will be placed in the RTL
1557 for an "asm" statement and will also be kept around a while if
1558 deferring constant output in varasm.c. */
1560 register tree s = make_node (STRING_CST);
1562 TREE_STRING_LENGTH (s) = len;
1563 if (ggc_p)
1564 TREE_STRING_POINTER (s) = ggc_alloc_string (str, len);
1565 else
1566 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1568 return s;
1571 /* Return a newly constructed COMPLEX_CST node whose value is
1572 specified by the real and imaginary parts REAL and IMAG.
1573 Both REAL and IMAG should be constant nodes. TYPE, if specified,
1574 will be the type of the COMPLEX_CST; otherwise a new type will be made. */
1576 tree
1577 build_complex (type, real, imag)
1578 tree type;
1579 tree real, imag;
1581 register tree t = make_node (COMPLEX_CST);
1583 TREE_REALPART (t) = real;
1584 TREE_IMAGPART (t) = imag;
1585 TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1586 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1587 TREE_CONSTANT_OVERFLOW (t)
1588 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1589 return t;
1592 /* Build a newly constructed TREE_VEC node of length LEN. */
1594 tree
1595 make_tree_vec (len)
1596 int len;
1598 register tree t;
1599 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1600 register struct obstack *obstack = current_obstack;
1602 #ifdef GATHER_STATISTICS
1603 tree_node_counts[(int)vec_kind]++;
1604 tree_node_sizes[(int)vec_kind] += length;
1605 #endif
1607 if (ggc_p)
1608 t = ggc_alloc_tree (length);
1609 else
1611 t = (tree) obstack_alloc (obstack, length);
1612 bzero ((PTR) t, length);
1615 TREE_SET_CODE (t, TREE_VEC);
1616 TREE_VEC_LENGTH (t) = len;
1617 TREE_SET_PERMANENT (t);
1619 return t;
1622 /* Return 1 if EXPR is the integer constant zero or a complex constant
1623 of zero. */
1626 integer_zerop (expr)
1627 tree expr;
1629 STRIP_NOPS (expr);
1631 return ((TREE_CODE (expr) == INTEGER_CST
1632 && ! TREE_CONSTANT_OVERFLOW (expr)
1633 && TREE_INT_CST_LOW (expr) == 0
1634 && TREE_INT_CST_HIGH (expr) == 0)
1635 || (TREE_CODE (expr) == COMPLEX_CST
1636 && integer_zerop (TREE_REALPART (expr))
1637 && integer_zerop (TREE_IMAGPART (expr))));
1640 /* Return 1 if EXPR is the integer constant one or the corresponding
1641 complex constant. */
1644 integer_onep (expr)
1645 tree expr;
1647 STRIP_NOPS (expr);
1649 return ((TREE_CODE (expr) == INTEGER_CST
1650 && ! TREE_CONSTANT_OVERFLOW (expr)
1651 && TREE_INT_CST_LOW (expr) == 1
1652 && TREE_INT_CST_HIGH (expr) == 0)
1653 || (TREE_CODE (expr) == COMPLEX_CST
1654 && integer_onep (TREE_REALPART (expr))
1655 && integer_zerop (TREE_IMAGPART (expr))));
1658 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1659 it contains. Likewise for the corresponding complex constant. */
1662 integer_all_onesp (expr)
1663 tree expr;
1665 register int prec;
1666 register int uns;
1668 STRIP_NOPS (expr);
1670 if (TREE_CODE (expr) == COMPLEX_CST
1671 && integer_all_onesp (TREE_REALPART (expr))
1672 && integer_zerop (TREE_IMAGPART (expr)))
1673 return 1;
1675 else if (TREE_CODE (expr) != INTEGER_CST
1676 || TREE_CONSTANT_OVERFLOW (expr))
1677 return 0;
1679 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1680 if (!uns)
1681 return (TREE_INT_CST_LOW (expr) == ~ (unsigned HOST_WIDE_INT) 0
1682 && TREE_INT_CST_HIGH (expr) == -1);
1684 /* Note that using TYPE_PRECISION here is wrong. We care about the
1685 actual bits, not the (arbitrary) range of the type. */
1686 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1687 if (prec >= HOST_BITS_PER_WIDE_INT)
1689 HOST_WIDE_INT high_value;
1690 int shift_amount;
1692 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1694 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1695 /* Can not handle precisions greater than twice the host int size. */
1696 abort ();
1697 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1698 /* Shifting by the host word size is undefined according to the ANSI
1699 standard, so we must handle this as a special case. */
1700 high_value = -1;
1701 else
1702 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1704 return (TREE_INT_CST_LOW (expr) == ~ (unsigned HOST_WIDE_INT) 0
1705 && TREE_INT_CST_HIGH (expr) == high_value);
1707 else
1708 return TREE_INT_CST_LOW (expr) == ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1711 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1712 one bit on). */
1715 integer_pow2p (expr)
1716 tree expr;
1718 int prec;
1719 HOST_WIDE_INT high, low;
1721 STRIP_NOPS (expr);
1723 if (TREE_CODE (expr) == COMPLEX_CST
1724 && integer_pow2p (TREE_REALPART (expr))
1725 && integer_zerop (TREE_IMAGPART (expr)))
1726 return 1;
1728 if (TREE_CODE (expr) != INTEGER_CST || TREE_CONSTANT_OVERFLOW (expr))
1729 return 0;
1731 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1732 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1733 high = TREE_INT_CST_HIGH (expr);
1734 low = TREE_INT_CST_LOW (expr);
1736 /* First clear all bits that are beyond the type's precision in case
1737 we've been sign extended. */
1739 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1741 else if (prec > HOST_BITS_PER_WIDE_INT)
1742 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1743 else
1745 high = 0;
1746 if (prec < HOST_BITS_PER_WIDE_INT)
1747 low &= ~((HOST_WIDE_INT) (-1) << prec);
1750 if (high == 0 && low == 0)
1751 return 0;
1753 return ((high == 0 && (low & (low - 1)) == 0)
1754 || (low == 0 && (high & (high - 1)) == 0));
1757 /* Return the power of two represented by a tree node known to be a
1758 power of two. */
1761 tree_log2 (expr)
1762 tree expr;
1764 int prec;
1765 HOST_WIDE_INT high, low;
1767 STRIP_NOPS (expr);
1769 if (TREE_CODE (expr) == COMPLEX_CST)
1770 return tree_log2 (TREE_REALPART (expr));
1772 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1773 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1775 high = TREE_INT_CST_HIGH (expr);
1776 low = TREE_INT_CST_LOW (expr);
1778 /* First clear all bits that are beyond the type's precision in case
1779 we've been sign extended. */
1781 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1783 else if (prec > HOST_BITS_PER_WIDE_INT)
1784 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1785 else
1787 high = 0;
1788 if (prec < HOST_BITS_PER_WIDE_INT)
1789 low &= ~((HOST_WIDE_INT) (-1) << prec);
1792 return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1793 : exact_log2 (low));
1796 /* Similar, but return the largest integer Y such that 2 ** Y is less
1797 than or equal to EXPR. */
1800 tree_floor_log2 (expr)
1801 tree expr;
1803 int prec;
1804 HOST_WIDE_INT high, low;
1806 STRIP_NOPS (expr);
1808 if (TREE_CODE (expr) == COMPLEX_CST)
1809 return tree_log2 (TREE_REALPART (expr));
1811 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1812 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1814 high = TREE_INT_CST_HIGH (expr);
1815 low = TREE_INT_CST_LOW (expr);
1817 /* First clear all bits that are beyond the type's precision in case
1818 we've been sign extended. Ignore if type's precision hasn't been set
1819 since what we are doing is setting it. */
1821 if (prec == 2 * HOST_BITS_PER_WIDE_INT || prec == 0)
1823 else if (prec > HOST_BITS_PER_WIDE_INT)
1824 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1825 else
1827 high = 0;
1828 if (prec < HOST_BITS_PER_WIDE_INT)
1829 low &= ~((HOST_WIDE_INT) (-1) << prec);
1832 return (high != 0 ? HOST_BITS_PER_WIDE_INT + floor_log2 (high)
1833 : floor_log2 (low));
1836 /* Return 1 if EXPR is the real constant zero. */
1839 real_zerop (expr)
1840 tree expr;
1842 STRIP_NOPS (expr);
1844 return ((TREE_CODE (expr) == REAL_CST
1845 && ! TREE_CONSTANT_OVERFLOW (expr)
1846 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1847 || (TREE_CODE (expr) == COMPLEX_CST
1848 && real_zerop (TREE_REALPART (expr))
1849 && real_zerop (TREE_IMAGPART (expr))));
1852 /* Return 1 if EXPR is the real constant one in real or complex form. */
1855 real_onep (expr)
1856 tree expr;
1858 STRIP_NOPS (expr);
1860 return ((TREE_CODE (expr) == REAL_CST
1861 && ! TREE_CONSTANT_OVERFLOW (expr)
1862 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1863 || (TREE_CODE (expr) == COMPLEX_CST
1864 && real_onep (TREE_REALPART (expr))
1865 && real_zerop (TREE_IMAGPART (expr))));
1868 /* Return 1 if EXPR is the real constant two. */
1871 real_twop (expr)
1872 tree expr;
1874 STRIP_NOPS (expr);
1876 return ((TREE_CODE (expr) == REAL_CST
1877 && ! TREE_CONSTANT_OVERFLOW (expr)
1878 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1879 || (TREE_CODE (expr) == COMPLEX_CST
1880 && real_twop (TREE_REALPART (expr))
1881 && real_zerop (TREE_IMAGPART (expr))));
1884 /* Nonzero if EXP is a constant or a cast of a constant. */
1887 really_constant_p (exp)
1888 tree exp;
1890 /* This is not quite the same as STRIP_NOPS. It does more. */
1891 while (TREE_CODE (exp) == NOP_EXPR
1892 || TREE_CODE (exp) == CONVERT_EXPR
1893 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1894 exp = TREE_OPERAND (exp, 0);
1895 return TREE_CONSTANT (exp);
1898 /* Return first list element whose TREE_VALUE is ELEM.
1899 Return 0 if ELEM is not in LIST. */
1901 tree
1902 value_member (elem, list)
1903 tree elem, list;
1905 while (list)
1907 if (elem == TREE_VALUE (list))
1908 return list;
1909 list = TREE_CHAIN (list);
1911 return NULL_TREE;
1914 /* Return first list element whose TREE_PURPOSE is ELEM.
1915 Return 0 if ELEM is not in LIST. */
1917 tree
1918 purpose_member (elem, list)
1919 tree elem, list;
1921 while (list)
1923 if (elem == TREE_PURPOSE (list))
1924 return list;
1925 list = TREE_CHAIN (list);
1927 return NULL_TREE;
1930 /* Return first list element whose BINFO_TYPE is ELEM.
1931 Return 0 if ELEM is not in LIST. */
1933 tree
1934 binfo_member (elem, list)
1935 tree elem, list;
1937 while (list)
1939 if (elem == BINFO_TYPE (list))
1940 return list;
1941 list = TREE_CHAIN (list);
1943 return NULL_TREE;
1946 /* Return nonzero if ELEM is part of the chain CHAIN. */
1949 chain_member (elem, chain)
1950 tree elem, chain;
1952 while (chain)
1954 if (elem == chain)
1955 return 1;
1956 chain = TREE_CHAIN (chain);
1959 return 0;
1962 /* Return nonzero if ELEM is equal to TREE_VALUE (CHAIN) for any piece of
1963 chain CHAIN. This and the next function are currently unused, but
1964 are retained for completeness. */
1967 chain_member_value (elem, chain)
1968 tree elem, chain;
1970 while (chain)
1972 if (elem == TREE_VALUE (chain))
1973 return 1;
1974 chain = TREE_CHAIN (chain);
1977 return 0;
1980 /* Return nonzero if ELEM is equal to TREE_PURPOSE (CHAIN)
1981 for any piece of chain CHAIN. */
1984 chain_member_purpose (elem, chain)
1985 tree elem, chain;
1987 while (chain)
1989 if (elem == TREE_PURPOSE (chain))
1990 return 1;
1991 chain = TREE_CHAIN (chain);
1994 return 0;
1997 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1998 We expect a null pointer to mark the end of the chain.
1999 This is the Lisp primitive `length'. */
2002 list_length (t)
2003 tree t;
2005 register tree tail;
2006 register int len = 0;
2008 for (tail = t; tail; tail = TREE_CHAIN (tail))
2009 len++;
2011 return len;
2014 /* Returns the number of FIELD_DECLs in TYPE. */
2017 fields_length (type)
2018 tree type;
2020 tree t = TYPE_FIELDS (type);
2021 int count = 0;
2023 for (; t; t = TREE_CHAIN (t))
2024 if (TREE_CODE (t) == FIELD_DECL)
2025 ++count;
2027 return count;
2030 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
2031 by modifying the last node in chain 1 to point to chain 2.
2032 This is the Lisp primitive `nconc'. */
2034 tree
2035 chainon (op1, op2)
2036 tree op1, op2;
2039 if (op1)
2041 register tree t1;
2042 #ifdef ENABLE_TREE_CHECKING
2043 register tree t2;
2044 #endif
2046 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
2048 TREE_CHAIN (t1) = op2;
2049 #ifdef ENABLE_TREE_CHECKING
2050 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
2051 if (t2 == t1)
2052 abort (); /* Circularity created. */
2053 #endif
2054 return op1;
2056 else return op2;
2059 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
2061 tree
2062 tree_last (chain)
2063 register tree chain;
2065 register tree next;
2066 if (chain)
2067 while ((next = TREE_CHAIN (chain)))
2068 chain = next;
2069 return chain;
2072 /* Reverse the order of elements in the chain T,
2073 and return the new head of the chain (old last element). */
2075 tree
2076 nreverse (t)
2077 tree t;
2079 register tree prev = 0, decl, next;
2080 for (decl = t; decl; decl = next)
2082 next = TREE_CHAIN (decl);
2083 TREE_CHAIN (decl) = prev;
2084 prev = decl;
2086 return prev;
2089 /* Given a chain CHAIN of tree nodes,
2090 construct and return a list of those nodes. */
2092 tree
2093 listify (chain)
2094 tree chain;
2096 tree result = NULL_TREE;
2097 tree in_tail = chain;
2098 tree out_tail = NULL_TREE;
2100 while (in_tail)
2102 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
2103 if (out_tail)
2104 TREE_CHAIN (out_tail) = next;
2105 else
2106 result = next;
2107 out_tail = next;
2108 in_tail = TREE_CHAIN (in_tail);
2111 return result;
2114 /* Return a newly created TREE_LIST node whose
2115 purpose and value fields are PARM and VALUE. */
2117 tree
2118 build_tree_list (parm, value)
2119 tree parm, value;
2121 register tree t = make_node (TREE_LIST);
2122 TREE_PURPOSE (t) = parm;
2123 TREE_VALUE (t) = value;
2124 return t;
2127 /* Similar, but build on the temp_decl_obstack. */
2129 tree
2130 build_decl_list (parm, value)
2131 tree parm, value;
2133 register tree node;
2134 register struct obstack *ambient_obstack = current_obstack;
2136 current_obstack = &temp_decl_obstack;
2137 node = build_tree_list (parm, value);
2138 current_obstack = ambient_obstack;
2139 return node;
2142 /* Similar, but build on the expression_obstack. */
2144 tree
2145 build_expr_list (parm, value)
2146 tree parm, value;
2148 register tree node;
2149 register struct obstack *ambient_obstack = current_obstack;
2151 current_obstack = expression_obstack;
2152 node = build_tree_list (parm, value);
2153 current_obstack = ambient_obstack;
2154 return node;
2157 /* Return a newly created TREE_LIST node whose
2158 purpose and value fields are PARM and VALUE
2159 and whose TREE_CHAIN is CHAIN. */
2161 tree
2162 tree_cons (purpose, value, chain)
2163 tree purpose, value, chain;
2165 register tree node;
2167 if (ggc_p)
2168 node = ggc_alloc_tree (sizeof (struct tree_list));
2169 else
2171 node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
2172 memset (node, 0, sizeof (struct tree_common));
2175 #ifdef GATHER_STATISTICS
2176 tree_node_counts[(int) x_kind]++;
2177 tree_node_sizes[(int) x_kind] += sizeof (struct tree_list);
2178 #endif
2180 TREE_SET_CODE (node, TREE_LIST);
2181 TREE_SET_PERMANENT (node);
2183 TREE_CHAIN (node) = chain;
2184 TREE_PURPOSE (node) = purpose;
2185 TREE_VALUE (node) = value;
2186 return node;
2189 /* Similar, but build on the temp_decl_obstack. */
2191 tree
2192 decl_tree_cons (purpose, value, chain)
2193 tree purpose, value, chain;
2195 register tree node;
2196 register struct obstack *ambient_obstack = current_obstack;
2198 current_obstack = &temp_decl_obstack;
2199 node = tree_cons (purpose, value, chain);
2200 current_obstack = ambient_obstack;
2201 return node;
2204 /* Similar, but build on the expression_obstack. */
2206 tree
2207 expr_tree_cons (purpose, value, chain)
2208 tree purpose, value, chain;
2210 register tree node;
2211 register struct obstack *ambient_obstack = current_obstack;
2213 current_obstack = expression_obstack;
2214 node = tree_cons (purpose, value, chain);
2215 current_obstack = ambient_obstack;
2216 return node;
2219 /* Same as `tree_cons' but make a permanent object. */
2221 tree
2222 perm_tree_cons (purpose, value, chain)
2223 tree purpose, value, chain;
2225 register tree node;
2226 register struct obstack *ambient_obstack = current_obstack;
2228 current_obstack = &permanent_obstack;
2229 node = tree_cons (purpose, value, chain);
2230 current_obstack = ambient_obstack;
2231 return node;
2234 /* Same as `tree_cons', but make this node temporary, regardless. */
2236 tree
2237 temp_tree_cons (purpose, value, chain)
2238 tree purpose, value, chain;
2240 register tree node;
2241 register struct obstack *ambient_obstack = current_obstack;
2243 current_obstack = &temporary_obstack;
2244 node = tree_cons (purpose, value, chain);
2245 current_obstack = ambient_obstack;
2246 return node;
2249 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
2251 tree
2252 saveable_tree_cons (purpose, value, chain)
2253 tree purpose, value, chain;
2255 register tree node;
2256 register struct obstack *ambient_obstack = current_obstack;
2258 current_obstack = saveable_obstack;
2259 node = tree_cons (purpose, value, chain);
2260 current_obstack = ambient_obstack;
2261 return node;
2264 /* Return the size nominally occupied by an object of type TYPE
2265 when it resides in memory. The value is measured in units of bytes,
2266 and its data type is that normally used for type sizes
2267 (which is the first type created by make_signed_type or
2268 make_unsigned_type). */
2270 tree
2271 size_in_bytes (type)
2272 tree type;
2274 tree t;
2276 if (type == error_mark_node)
2277 return integer_zero_node;
2279 type = TYPE_MAIN_VARIANT (type);
2280 t = TYPE_SIZE_UNIT (type);
2282 if (t == 0)
2284 incomplete_type_error (NULL_TREE, type);
2285 return size_zero_node;
2288 if (TREE_CODE (t) == INTEGER_CST)
2289 force_fit_type (t, 0);
2291 return t;
2294 /* Return the size of TYPE (in bytes) as a wide integer
2295 or return -1 if the size can vary or is larger than an integer. */
2297 HOST_WIDE_INT
2298 int_size_in_bytes (type)
2299 tree type;
2301 tree t;
2303 if (type == error_mark_node)
2304 return 0;
2306 type = TYPE_MAIN_VARIANT (type);
2307 t = TYPE_SIZE_UNIT (type);
2308 if (t == 0
2309 || TREE_CODE (t) != INTEGER_CST
2310 || TREE_OVERFLOW (t)
2311 || TREE_INT_CST_HIGH (t) != 0
2312 /* If the result would appear negative, it's too big to represent. */
2313 || (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0)
2314 return -1;
2316 return TREE_INT_CST_LOW (t);
2319 /* Return the bit position of FIELD, in bits from the start of the record.
2320 This is a tree of type bitsizetype. */
2322 tree
2323 bit_position (field)
2324 tree field;
2327 return bit_from_pos (DECL_FIELD_OFFSET (field),
2328 DECL_FIELD_BIT_OFFSET (field));
2331 /* Likewise, but return as an integer. Abort if it cannot be represented
2332 in that way (since it could be a signed value, we don't have the option
2333 of returning -1 like int_size_in_byte can. */
2335 HOST_WIDE_INT
2336 int_bit_position (field)
2337 tree field;
2339 return tree_low_cst (bit_position (field), 0);
2342 /* Return the byte position of FIELD, in bytes from the start of the record.
2343 This is a tree of type sizetype. */
2345 tree
2346 byte_position (field)
2347 tree field;
2349 return byte_from_pos (DECL_FIELD_OFFSET (field),
2350 DECL_FIELD_BIT_OFFSET (field));
2353 /* Likewise, but return as an integer. Abort if it cannot be represented
2354 in that way (since it could be a signed value, we don't have the option
2355 of returning -1 like int_size_in_byte can. */
2357 HOST_WIDE_INT
2358 int_byte_position (field)
2359 tree field;
2361 return tree_low_cst (byte_position (field), 0);
2364 /* Return the strictest alignment, in bits, that T is known to have. */
2366 unsigned int
2367 expr_align (t)
2368 tree t;
2370 unsigned int align0, align1;
2372 switch (TREE_CODE (t))
2374 case NOP_EXPR: case CONVERT_EXPR: case NON_LVALUE_EXPR:
2375 /* If we have conversions, we know that the alignment of the
2376 object must meet each of the alignments of the types. */
2377 align0 = expr_align (TREE_OPERAND (t, 0));
2378 align1 = TYPE_ALIGN (TREE_TYPE (t));
2379 return MAX (align0, align1);
2381 case SAVE_EXPR: case COMPOUND_EXPR: case MODIFY_EXPR:
2382 case INIT_EXPR: case TARGET_EXPR: case WITH_CLEANUP_EXPR:
2383 case WITH_RECORD_EXPR: case CLEANUP_POINT_EXPR: case UNSAVE_EXPR:
2384 /* These don't change the alignment of an object. */
2385 return expr_align (TREE_OPERAND (t, 0));
2387 case COND_EXPR:
2388 /* The best we can do is say that the alignment is the least aligned
2389 of the two arms. */
2390 align0 = expr_align (TREE_OPERAND (t, 1));
2391 align1 = expr_align (TREE_OPERAND (t, 2));
2392 return MIN (align0, align1);
2394 case LABEL_DECL: case CONST_DECL:
2395 case VAR_DECL: case PARM_DECL: case RESULT_DECL:
2396 if (DECL_ALIGN (t) != 0)
2397 return DECL_ALIGN (t);
2398 break;
2400 case FUNCTION_DECL:
2401 return FUNCTION_BOUNDARY;
2403 default:
2404 break;
2407 /* Otherwise take the alignment from that of the type. */
2408 return TYPE_ALIGN (TREE_TYPE (t));
2411 /* Return, as a tree node, the number of elements for TYPE (which is an
2412 ARRAY_TYPE) minus one. This counts only elements of the top array. */
2414 tree
2415 array_type_nelts (type)
2416 tree type;
2418 tree index_type, min, max;
2420 /* If they did it with unspecified bounds, then we should have already
2421 given an error about it before we got here. */
2422 if (! TYPE_DOMAIN (type))
2423 return error_mark_node;
2425 index_type = TYPE_DOMAIN (type);
2426 min = TYPE_MIN_VALUE (index_type);
2427 max = TYPE_MAX_VALUE (index_type);
2429 return (integer_zerop (min)
2430 ? max
2431 : fold (build (MINUS_EXPR, TREE_TYPE (max), max, min)));
2434 /* Return nonzero if arg is static -- a reference to an object in
2435 static storage. This is not the same as the C meaning of `static'. */
2438 staticp (arg)
2439 tree arg;
2441 switch (TREE_CODE (arg))
2443 case FUNCTION_DECL:
2444 /* Nested functions aren't static, since taking their address
2445 involves a trampoline. */
2446 return (decl_function_context (arg) == 0 || DECL_NO_STATIC_CHAIN (arg))
2447 && ! DECL_NON_ADDR_CONST_P (arg);
2449 case VAR_DECL:
2450 return (TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2451 && ! DECL_NON_ADDR_CONST_P (arg);
2453 case CONSTRUCTOR:
2454 return TREE_STATIC (arg);
2456 case LABEL_DECL:
2457 case STRING_CST:
2458 return 1;
2460 /* If we are referencing a bitfield, we can't evaluate an
2461 ADDR_EXPR at compile time and so it isn't a constant. */
2462 case COMPONENT_REF:
2463 return (! DECL_BIT_FIELD (TREE_OPERAND (arg, 1))
2464 && staticp (TREE_OPERAND (arg, 0)));
2466 case BIT_FIELD_REF:
2467 return 0;
2469 #if 0
2470 /* This case is technically correct, but results in setting
2471 TREE_CONSTANT on ADDR_EXPRs that cannot be evaluated at
2472 compile time. */
2473 case INDIRECT_REF:
2474 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
2475 #endif
2477 case ARRAY_REF:
2478 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2479 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2480 return staticp (TREE_OPERAND (arg, 0));
2482 default:
2483 return 0;
2487 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2488 Do this to any expression which may be used in more than one place,
2489 but must be evaluated only once.
2491 Normally, expand_expr would reevaluate the expression each time.
2492 Calling save_expr produces something that is evaluated and recorded
2493 the first time expand_expr is called on it. Subsequent calls to
2494 expand_expr just reuse the recorded value.
2496 The call to expand_expr that generates code that actually computes
2497 the value is the first call *at compile time*. Subsequent calls
2498 *at compile time* generate code to use the saved value.
2499 This produces correct result provided that *at run time* control
2500 always flows through the insns made by the first expand_expr
2501 before reaching the other places where the save_expr was evaluated.
2502 You, the caller of save_expr, must make sure this is so.
2504 Constants, and certain read-only nodes, are returned with no
2505 SAVE_EXPR because that is safe. Expressions containing placeholders
2506 are not touched; see tree.def for an explanation of what these
2507 are used for. */
2509 tree
2510 save_expr (expr)
2511 tree expr;
2513 register tree t = fold (expr);
2515 /* We don't care about whether this can be used as an lvalue in this
2516 context. */
2517 while (TREE_CODE (t) == NON_LVALUE_EXPR)
2518 t = TREE_OPERAND (t, 0);
2520 /* If the tree evaluates to a constant, then we don't want to hide that
2521 fact (i.e. this allows further folding, and direct checks for constants).
2522 However, a read-only object that has side effects cannot be bypassed.
2523 Since it is no problem to reevaluate literals, we just return the
2524 literal node. */
2526 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
2527 || TREE_CODE (t) == SAVE_EXPR || TREE_CODE (t) == ERROR_MARK)
2528 return t;
2530 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2531 it means that the size or offset of some field of an object depends on
2532 the value within another field.
2534 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2535 and some variable since it would then need to be both evaluated once and
2536 evaluated more than once. Front-ends must assure this case cannot
2537 happen by surrounding any such subexpressions in their own SAVE_EXPR
2538 and forcing evaluation at the proper time. */
2539 if (contains_placeholder_p (t))
2540 return t;
2542 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
2544 /* This expression might be placed ahead of a jump to ensure that the
2545 value was computed on both sides of the jump. So make sure it isn't
2546 eliminated as dead. */
2547 TREE_SIDE_EFFECTS (t) = 1;
2548 return t;
2551 /* Arrange for an expression to be expanded multiple independent
2552 times. This is useful for cleanup actions, as the backend can
2553 expand them multiple times in different places. */
2555 tree
2556 unsave_expr (expr)
2557 tree expr;
2559 tree t;
2561 /* If this is already protected, no sense in protecting it again. */
2562 if (TREE_CODE (expr) == UNSAVE_EXPR)
2563 return expr;
2565 t = build1 (UNSAVE_EXPR, TREE_TYPE (expr), expr);
2566 TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
2567 return t;
2570 /* Returns the index of the first non-tree operand for CODE, or the number
2571 of operands if all are trees. */
2574 first_rtl_op (code)
2575 enum tree_code code;
2577 switch (code)
2579 case SAVE_EXPR:
2580 return 2;
2581 case GOTO_SUBROUTINE_EXPR:
2582 case RTL_EXPR:
2583 return 0;
2584 case CALL_EXPR:
2585 return 2;
2586 case WITH_CLEANUP_EXPR:
2587 /* Should be defined to be 2. */
2588 return 1;
2589 case METHOD_CALL_EXPR:
2590 return 3;
2591 default:
2592 return tree_code_length [(int) code];
2596 /* Perform any modifications to EXPR required when it is unsaved. Does
2597 not recurse into EXPR's subtrees. */
2599 void
2600 unsave_expr_1 (expr)
2601 tree expr;
2603 switch (TREE_CODE (expr))
2605 case SAVE_EXPR:
2606 if (! SAVE_EXPR_PERSISTENT_P (expr))
2607 SAVE_EXPR_RTL (expr) = 0;
2608 break;
2610 case TARGET_EXPR:
2611 /* Don't mess with a TARGET_EXPR that hasn't been expanded.
2612 It's OK for this to happen if it was part of a subtree that
2613 isn't immediately expanded, such as operand 2 of another
2614 TARGET_EXPR. */
2615 if (TREE_OPERAND (expr, 1))
2616 break;
2618 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 3);
2619 TREE_OPERAND (expr, 3) = NULL_TREE;
2620 break;
2622 case RTL_EXPR:
2623 /* I don't yet know how to emit a sequence multiple times. */
2624 if (RTL_EXPR_SEQUENCE (expr) != 0)
2625 abort ();
2626 break;
2628 case CALL_EXPR:
2629 CALL_EXPR_RTL (expr) = 0;
2630 break;
2632 default:
2633 if (lang_unsave_expr_now != 0)
2634 (*lang_unsave_expr_now) (expr);
2635 break;
2639 /* Helper function for unsave_expr_now. */
2641 static void
2642 unsave_expr_now_r (expr)
2643 tree expr;
2645 enum tree_code code;
2647 /* There's nothing to do for NULL_TREE. */
2648 if (expr == 0)
2649 return;
2651 unsave_expr_1 (expr);
2653 code = TREE_CODE (expr);
2654 switch (TREE_CODE_CLASS (code))
2656 case 'c': /* a constant */
2657 case 't': /* a type node */
2658 case 'd': /* A decl node */
2659 case 'b': /* A block node */
2660 break;
2662 case 'x': /* miscellaneous: e.g., identifier, TREE_LIST or ERROR_MARK. */
2663 if (code == TREE_LIST)
2665 unsave_expr_now_r (TREE_VALUE (expr));
2666 unsave_expr_now_r (TREE_CHAIN (expr));
2668 break;
2670 case 'e': /* an expression */
2671 case 'r': /* a reference */
2672 case 's': /* an expression with side effects */
2673 case '<': /* a comparison expression */
2674 case '2': /* a binary arithmetic expression */
2675 case '1': /* a unary arithmetic expression */
2677 int i;
2679 for (i = first_rtl_op (code) - 1; i >= 0; i--)
2680 unsave_expr_now_r (TREE_OPERAND (expr, i));
2682 break;
2684 default:
2685 abort ();
2689 /* Modify a tree in place so that all the evaluate only once things
2690 are cleared out. Return the EXPR given. */
2692 tree
2693 unsave_expr_now (expr)
2694 tree expr;
2696 if (lang_unsave!= 0)
2697 (*lang_unsave) (&expr);
2698 else
2699 unsave_expr_now_r (expr);
2701 return expr;
2704 /* Return 0 if it is safe to evaluate EXPR multiple times,
2705 return 1 if it is safe if EXPR is unsaved afterward, or
2706 return 2 if it is completely unsafe.
2708 This assumes that CALL_EXPRs and TARGET_EXPRs are never replicated in
2709 an expression tree, so that it safe to unsave them and the surrounding
2710 context will be correct.
2712 SAVE_EXPRs basically *only* appear replicated in an expression tree,
2713 occasionally across the whole of a function. It is therefore only
2714 safe to unsave a SAVE_EXPR if you know that all occurrences appear
2715 below the UNSAVE_EXPR.
2717 RTL_EXPRs consume their rtl during evaluation. It is therefore
2718 never possible to unsave them. */
2721 unsafe_for_reeval (expr)
2722 tree expr;
2724 int unsafeness = 0;
2725 enum tree_code code;
2726 int i, tmp;
2727 tree exp;
2728 int first_rtl;
2730 if (expr == NULL_TREE)
2731 return 1;
2733 code = TREE_CODE (expr);
2734 first_rtl = first_rtl_op (code);
2736 switch (code)
2738 case SAVE_EXPR:
2739 case RTL_EXPR:
2740 return 2;
2742 case TREE_LIST:
2743 for (exp = expr; exp != 0; exp = TREE_CHAIN (exp))
2745 tmp = unsafe_for_reeval (TREE_VALUE (exp));
2746 unsafeness = MAX (tmp, unsafeness);
2749 return unsafeness;
2751 case CALL_EXPR:
2752 tmp = unsafe_for_reeval (TREE_OPERAND (expr, 1));
2753 return MAX (tmp, 1);
2755 case TARGET_EXPR:
2756 unsafeness = 1;
2757 break;
2759 default:
2760 /* ??? Add a lang hook if it becomes necessary. */
2761 break;
2764 switch (TREE_CODE_CLASS (code))
2766 case 'c': /* a constant */
2767 case 't': /* a type node */
2768 case 'x': /* something random, like an identifier or an ERROR_MARK. */
2769 case 'd': /* A decl node */
2770 case 'b': /* A block node */
2771 return 0;
2773 case 'e': /* an expression */
2774 case 'r': /* a reference */
2775 case 's': /* an expression with side effects */
2776 case '<': /* a comparison expression */
2777 case '2': /* a binary arithmetic expression */
2778 case '1': /* a unary arithmetic expression */
2779 for (i = first_rtl - 1; i >= 0; i--)
2781 tmp = unsafe_for_reeval (TREE_OPERAND (expr, i));
2782 unsafeness = MAX (tmp, unsafeness);
2785 return unsafeness;
2787 default:
2788 return 2;
2792 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2793 or offset that depends on a field within a record. */
2796 contains_placeholder_p (exp)
2797 tree exp;
2799 register enum tree_code code = TREE_CODE (exp);
2800 int result;
2802 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2803 in it since it is supplying a value for it. */
2804 if (code == WITH_RECORD_EXPR)
2805 return 0;
2806 else if (code == PLACEHOLDER_EXPR)
2807 return 1;
2809 switch (TREE_CODE_CLASS (code))
2811 case 'r':
2812 /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2813 position computations since they will be converted into a
2814 WITH_RECORD_EXPR involving the reference, which will assume
2815 here will be valid. */
2816 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2818 case 'x':
2819 if (code == TREE_LIST)
2820 return (contains_placeholder_p (TREE_VALUE (exp))
2821 || (TREE_CHAIN (exp) != 0
2822 && contains_placeholder_p (TREE_CHAIN (exp))));
2823 break;
2825 case '1':
2826 case '2': case '<':
2827 case 'e':
2828 switch (code)
2830 case COMPOUND_EXPR:
2831 /* Ignoring the first operand isn't quite right, but works best. */
2832 return contains_placeholder_p (TREE_OPERAND (exp, 1));
2834 case RTL_EXPR:
2835 case CONSTRUCTOR:
2836 return 0;
2838 case COND_EXPR:
2839 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2840 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2841 || contains_placeholder_p (TREE_OPERAND (exp, 2)));
2843 case SAVE_EXPR:
2844 /* If we already know this doesn't have a placeholder, don't
2845 check again. */
2846 if (SAVE_EXPR_NOPLACEHOLDER (exp) || SAVE_EXPR_RTL (exp) != 0)
2847 return 0;
2849 SAVE_EXPR_NOPLACEHOLDER (exp) = 1;
2850 result = contains_placeholder_p (TREE_OPERAND (exp, 0));
2851 if (result)
2852 SAVE_EXPR_NOPLACEHOLDER (exp) = 0;
2854 return result;
2856 case CALL_EXPR:
2857 return (TREE_OPERAND (exp, 1) != 0
2858 && contains_placeholder_p (TREE_OPERAND (exp, 1)));
2860 default:
2861 break;
2864 switch (tree_code_length[(int) code])
2866 case 1:
2867 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2868 case 2:
2869 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2870 || contains_placeholder_p (TREE_OPERAND (exp, 1)));
2871 default:
2872 return 0;
2875 default:
2876 return 0;
2878 return 0;
2881 /* Return 1 if EXP contains any expressions that produce cleanups for an
2882 outer scope to deal with. Used by fold. */
2885 has_cleanups (exp)
2886 tree exp;
2888 int i, nops, cmp;
2890 if (! TREE_SIDE_EFFECTS (exp))
2891 return 0;
2893 switch (TREE_CODE (exp))
2895 case TARGET_EXPR:
2896 case GOTO_SUBROUTINE_EXPR:
2897 case WITH_CLEANUP_EXPR:
2898 return 1;
2900 case CLEANUP_POINT_EXPR:
2901 return 0;
2903 case CALL_EXPR:
2904 for (exp = TREE_OPERAND (exp, 1); exp; exp = TREE_CHAIN (exp))
2906 cmp = has_cleanups (TREE_VALUE (exp));
2907 if (cmp)
2908 return cmp;
2910 return 0;
2912 default:
2913 break;
2916 /* This general rule works for most tree codes. All exceptions should be
2917 handled above. If this is a language-specific tree code, we can't
2918 trust what might be in the operand, so say we don't know
2919 the situation. */
2920 if ((int) TREE_CODE (exp) >= (int) LAST_AND_UNUSED_TREE_CODE)
2921 return -1;
2923 nops = first_rtl_op (TREE_CODE (exp));
2924 for (i = 0; i < nops; i++)
2925 if (TREE_OPERAND (exp, i) != 0)
2927 int type = TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, i)));
2928 if (type == 'e' || type == '<' || type == '1' || type == '2'
2929 || type == 'r' || type == 's')
2931 cmp = has_cleanups (TREE_OPERAND (exp, i));
2932 if (cmp)
2933 return cmp;
2937 return 0;
2940 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2941 return a tree with all occurrences of references to F in a
2942 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2943 contains only arithmetic expressions or a CALL_EXPR with a
2944 PLACEHOLDER_EXPR occurring only in its arglist. */
2946 tree
2947 substitute_in_expr (exp, f, r)
2948 tree exp;
2949 tree f;
2950 tree r;
2952 enum tree_code code = TREE_CODE (exp);
2953 tree op0, op1, op2;
2954 tree new;
2955 tree inner;
2957 switch (TREE_CODE_CLASS (code))
2959 case 'c':
2960 case 'd':
2961 return exp;
2963 case 'x':
2964 if (code == PLACEHOLDER_EXPR)
2965 return exp;
2966 else if (code == TREE_LIST)
2968 op0 = (TREE_CHAIN (exp) == 0
2969 ? 0 : substitute_in_expr (TREE_CHAIN (exp), f, r));
2970 op1 = substitute_in_expr (TREE_VALUE (exp), f, r);
2971 if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2972 return exp;
2974 return tree_cons (TREE_PURPOSE (exp), op1, op0);
2977 abort ();
2979 case '1':
2980 case '2':
2981 case '<':
2982 case 'e':
2983 switch (tree_code_length[(int) code])
2985 case 1:
2986 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2987 if (op0 == TREE_OPERAND (exp, 0))
2988 return exp;
2990 new = fold (build1 (code, TREE_TYPE (exp), op0));
2991 break;
2993 case 2:
2994 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2995 could, but we don't support it. */
2996 if (code == RTL_EXPR)
2997 return exp;
2998 else if (code == CONSTRUCTOR)
2999 abort ();
3001 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
3002 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
3003 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
3004 return exp;
3006 new = fold (build (code, TREE_TYPE (exp), op0, op1));
3007 break;
3009 case 3:
3010 /* It cannot be that anything inside a SAVE_EXPR contains a
3011 PLACEHOLDER_EXPR. */
3012 if (code == SAVE_EXPR)
3013 return exp;
3015 else if (code == CALL_EXPR)
3017 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
3018 if (op1 == TREE_OPERAND (exp, 1))
3019 return exp;
3021 return build (code, TREE_TYPE (exp),
3022 TREE_OPERAND (exp, 0), op1, NULL_TREE);
3025 else if (code != COND_EXPR)
3026 abort ();
3028 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
3029 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
3030 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
3031 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3032 && op2 == TREE_OPERAND (exp, 2))
3033 return exp;
3035 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
3036 break;
3038 default:
3039 abort ();
3042 break;
3044 case 'r':
3045 switch (code)
3047 case COMPONENT_REF:
3048 /* If this expression is getting a value from a PLACEHOLDER_EXPR
3049 and it is the right field, replace it with R. */
3050 for (inner = TREE_OPERAND (exp, 0);
3051 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
3052 inner = TREE_OPERAND (inner, 0))
3054 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
3055 && TREE_OPERAND (exp, 1) == f)
3056 return r;
3058 /* If this expression hasn't been completed let, leave it
3059 alone. */
3060 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
3061 && TREE_TYPE (inner) == 0)
3062 return exp;
3064 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
3065 if (op0 == TREE_OPERAND (exp, 0))
3066 return exp;
3068 new = fold (build (code, TREE_TYPE (exp), op0,
3069 TREE_OPERAND (exp, 1)));
3070 break;
3072 case BIT_FIELD_REF:
3073 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
3074 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
3075 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
3076 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3077 && op2 == TREE_OPERAND (exp, 2))
3078 return exp;
3080 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
3081 break;
3083 case INDIRECT_REF:
3084 case BUFFER_REF:
3085 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
3086 if (op0 == TREE_OPERAND (exp, 0))
3087 return exp;
3089 new = fold (build1 (code, TREE_TYPE (exp), op0));
3090 break;
3092 default:
3093 abort ();
3095 break;
3097 default:
3098 abort ();
3101 TREE_READONLY (new) = TREE_READONLY (exp);
3102 return new;
3105 /* Stabilize a reference so that we can use it any number of times
3106 without causing its operands to be evaluated more than once.
3107 Returns the stabilized reference. This works by means of save_expr,
3108 so see the caveats in the comments about save_expr.
3110 Also allows conversion expressions whose operands are references.
3111 Any other kind of expression is returned unchanged. */
3113 tree
3114 stabilize_reference (ref)
3115 tree ref;
3117 register tree result;
3118 register enum tree_code code = TREE_CODE (ref);
3120 switch (code)
3122 case VAR_DECL:
3123 case PARM_DECL:
3124 case RESULT_DECL:
3125 /* No action is needed in this case. */
3126 return ref;
3128 case NOP_EXPR:
3129 case CONVERT_EXPR:
3130 case FLOAT_EXPR:
3131 case FIX_TRUNC_EXPR:
3132 case FIX_FLOOR_EXPR:
3133 case FIX_ROUND_EXPR:
3134 case FIX_CEIL_EXPR:
3135 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
3136 break;
3138 case INDIRECT_REF:
3139 result = build_nt (INDIRECT_REF,
3140 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
3141 break;
3143 case COMPONENT_REF:
3144 result = build_nt (COMPONENT_REF,
3145 stabilize_reference (TREE_OPERAND (ref, 0)),
3146 TREE_OPERAND (ref, 1));
3147 break;
3149 case BIT_FIELD_REF:
3150 result = build_nt (BIT_FIELD_REF,
3151 stabilize_reference (TREE_OPERAND (ref, 0)),
3152 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
3153 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
3154 break;
3156 case ARRAY_REF:
3157 result = build_nt (ARRAY_REF,
3158 stabilize_reference (TREE_OPERAND (ref, 0)),
3159 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
3160 break;
3162 case COMPOUND_EXPR:
3163 /* We cannot wrap the first expression in a SAVE_EXPR, as then
3164 it wouldn't be ignored. This matters when dealing with
3165 volatiles. */
3166 return stabilize_reference_1 (ref);
3168 case RTL_EXPR:
3169 result = build1 (INDIRECT_REF, TREE_TYPE (ref),
3170 save_expr (build1 (ADDR_EXPR,
3171 build_pointer_type (TREE_TYPE (ref)),
3172 ref)));
3173 break;
3176 /* If arg isn't a kind of lvalue we recognize, make no change.
3177 Caller should recognize the error for an invalid lvalue. */
3178 default:
3179 return ref;
3181 case ERROR_MARK:
3182 return error_mark_node;
3185 TREE_TYPE (result) = TREE_TYPE (ref);
3186 TREE_READONLY (result) = TREE_READONLY (ref);
3187 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
3188 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
3190 return result;
3193 /* Subroutine of stabilize_reference; this is called for subtrees of
3194 references. Any expression with side-effects must be put in a SAVE_EXPR
3195 to ensure that it is only evaluated once.
3197 We don't put SAVE_EXPR nodes around everything, because assigning very
3198 simple expressions to temporaries causes us to miss good opportunities
3199 for optimizations. Among other things, the opportunity to fold in the
3200 addition of a constant into an addressing mode often gets lost, e.g.
3201 "y[i+1] += x;". In general, we take the approach that we should not make
3202 an assignment unless we are forced into it - i.e., that any non-side effect
3203 operator should be allowed, and that cse should take care of coalescing
3204 multiple utterances of the same expression should that prove fruitful. */
3206 tree
3207 stabilize_reference_1 (e)
3208 tree e;
3210 register tree result;
3211 register enum tree_code code = TREE_CODE (e);
3213 /* We cannot ignore const expressions because it might be a reference
3214 to a const array but whose index contains side-effects. But we can
3215 ignore things that are actual constant or that already have been
3216 handled by this function. */
3218 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
3219 return e;
3221 switch (TREE_CODE_CLASS (code))
3223 case 'x':
3224 case 't':
3225 case 'd':
3226 case 'b':
3227 case '<':
3228 case 's':
3229 case 'e':
3230 case 'r':
3231 /* If the expression has side-effects, then encase it in a SAVE_EXPR
3232 so that it will only be evaluated once. */
3233 /* The reference (r) and comparison (<) classes could be handled as
3234 below, but it is generally faster to only evaluate them once. */
3235 if (TREE_SIDE_EFFECTS (e))
3236 return save_expr (e);
3237 return e;
3239 case 'c':
3240 /* Constants need no processing. In fact, we should never reach
3241 here. */
3242 return e;
3244 case '2':
3245 /* Division is slow and tends to be compiled with jumps,
3246 especially the division by powers of 2 that is often
3247 found inside of an array reference. So do it just once. */
3248 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
3249 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
3250 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
3251 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
3252 return save_expr (e);
3253 /* Recursively stabilize each operand. */
3254 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
3255 stabilize_reference_1 (TREE_OPERAND (e, 1)));
3256 break;
3258 case '1':
3259 /* Recursively stabilize each operand. */
3260 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
3261 break;
3263 default:
3264 abort ();
3267 TREE_TYPE (result) = TREE_TYPE (e);
3268 TREE_READONLY (result) = TREE_READONLY (e);
3269 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
3270 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
3272 return result;
3275 /* Low-level constructors for expressions. */
3277 /* Build an expression of code CODE, data type TYPE,
3278 and operands as specified by the arguments ARG1 and following arguments.
3279 Expressions and reference nodes can be created this way.
3280 Constants, decls, types and misc nodes cannot be. */
3282 tree
3283 build VPARAMS ((enum tree_code code, tree tt, ...))
3285 #ifndef ANSI_PROTOTYPES
3286 enum tree_code code;
3287 tree tt;
3288 #endif
3289 va_list p;
3290 register tree t;
3291 register int length;
3292 register int i;
3293 int fro;
3295 VA_START (p, tt);
3297 #ifndef ANSI_PROTOTYPES
3298 code = va_arg (p, enum tree_code);
3299 tt = va_arg (p, tree);
3300 #endif
3302 t = make_node (code);
3303 length = tree_code_length[(int) code];
3304 TREE_TYPE (t) = tt;
3306 /* Below, we automatically set TREE_SIDE_EFFECTS and TREE_RAISED for
3307 the result based on those same flags for the arguments. But, if
3308 the arguments aren't really even `tree' expressions, we shouldn't
3309 be trying to do this. */
3310 fro = first_rtl_op (code);
3312 if (length == 2)
3314 /* This is equivalent to the loop below, but faster. */
3315 register tree arg0 = va_arg (p, tree);
3316 register tree arg1 = va_arg (p, tree);
3317 TREE_OPERAND (t, 0) = arg0;
3318 TREE_OPERAND (t, 1) = arg1;
3319 if (arg0 && fro > 0)
3321 if (TREE_SIDE_EFFECTS (arg0))
3322 TREE_SIDE_EFFECTS (t) = 1;
3324 if (arg1 && fro > 1)
3326 if (TREE_SIDE_EFFECTS (arg1))
3327 TREE_SIDE_EFFECTS (t) = 1;
3330 else if (length == 1)
3332 register tree arg0 = va_arg (p, tree);
3334 /* Call build1 for this! */
3335 if (TREE_CODE_CLASS (code) != 's')
3336 abort ();
3337 TREE_OPERAND (t, 0) = arg0;
3338 if (fro > 0)
3340 if (arg0 && TREE_SIDE_EFFECTS (arg0))
3341 TREE_SIDE_EFFECTS (t) = 1;
3344 else
3346 for (i = 0; i < length; i++)
3348 register tree operand = va_arg (p, tree);
3349 TREE_OPERAND (t, i) = operand;
3350 if (operand && fro > i)
3352 if (TREE_SIDE_EFFECTS (operand))
3353 TREE_SIDE_EFFECTS (t) = 1;
3357 va_end (p);
3358 return t;
3361 /* Same as above, but only builds for unary operators.
3362 Saves lions share of calls to `build'; cuts down use
3363 of varargs, which is expensive for RISC machines. */
3365 tree
3366 build1 (code, type, node)
3367 enum tree_code code;
3368 tree type;
3369 tree node;
3371 register struct obstack *obstack = expression_obstack;
3372 register int length;
3373 #ifdef GATHER_STATISTICS
3374 register tree_node_kind kind;
3375 #endif
3376 register tree t;
3378 #ifdef GATHER_STATISTICS
3379 if (TREE_CODE_CLASS (code) == 'r')
3380 kind = r_kind;
3381 else
3382 kind = e_kind;
3383 #endif
3385 length = sizeof (struct tree_exp);
3387 if (ggc_p)
3388 t = ggc_alloc_tree (length);
3389 else
3391 t = (tree) obstack_alloc (obstack, length);
3392 memset ((PTR) t, 0, length);
3395 #ifdef GATHER_STATISTICS
3396 tree_node_counts[(int)kind]++;
3397 tree_node_sizes[(int)kind] += length;
3398 #endif
3400 TREE_TYPE (t) = type;
3401 TREE_SET_CODE (t, code);
3402 TREE_SET_PERMANENT (t);
3404 TREE_OPERAND (t, 0) = node;
3405 if (node && first_rtl_op (code) != 0 && TREE_SIDE_EFFECTS (node))
3406 TREE_SIDE_EFFECTS (t) = 1;
3408 switch (code)
3410 case INIT_EXPR:
3411 case MODIFY_EXPR:
3412 case VA_ARG_EXPR:
3413 case RTL_EXPR:
3414 case PREDECREMENT_EXPR:
3415 case PREINCREMENT_EXPR:
3416 case POSTDECREMENT_EXPR:
3417 case POSTINCREMENT_EXPR:
3418 /* All of these have side-effects, no matter what their
3419 operands are. */
3420 TREE_SIDE_EFFECTS (t) = 1;
3421 break;
3423 default:
3424 break;
3427 return t;
3430 /* Similar except don't specify the TREE_TYPE
3431 and leave the TREE_SIDE_EFFECTS as 0.
3432 It is permissible for arguments to be null,
3433 or even garbage if their values do not matter. */
3435 tree
3436 build_nt VPARAMS ((enum tree_code code, ...))
3438 #ifndef ANSI_PROTOTYPES
3439 enum tree_code code;
3440 #endif
3441 va_list p;
3442 register tree t;
3443 register int length;
3444 register int i;
3446 VA_START (p, code);
3448 #ifndef ANSI_PROTOTYPES
3449 code = va_arg (p, enum tree_code);
3450 #endif
3452 t = make_node (code);
3453 length = tree_code_length[(int) code];
3455 for (i = 0; i < length; i++)
3456 TREE_OPERAND (t, i) = va_arg (p, tree);
3458 va_end (p);
3459 return t;
3462 /* Similar to `build_nt', except we build
3463 on the temp_decl_obstack, regardless. */
3465 tree
3466 build_parse_node VPARAMS ((enum tree_code code, ...))
3468 #ifndef ANSI_PROTOTYPES
3469 enum tree_code code;
3470 #endif
3471 register struct obstack *ambient_obstack = expression_obstack;
3472 va_list p;
3473 register tree t;
3474 register int length;
3475 register int i;
3477 VA_START (p, code);
3479 #ifndef ANSI_PROTOTYPES
3480 code = va_arg (p, enum tree_code);
3481 #endif
3483 expression_obstack = &temp_decl_obstack;
3485 t = make_node (code);
3486 length = tree_code_length[(int) code];
3488 for (i = 0; i < length; i++)
3489 TREE_OPERAND (t, i) = va_arg (p, tree);
3491 va_end (p);
3492 expression_obstack = ambient_obstack;
3493 return t;
3496 #if 0
3497 /* Commented out because this wants to be done very
3498 differently. See cp-lex.c. */
3499 tree
3500 build_op_identifier (op1, op2)
3501 tree op1, op2;
3503 register tree t = make_node (OP_IDENTIFIER);
3504 TREE_PURPOSE (t) = op1;
3505 TREE_VALUE (t) = op2;
3506 return t;
3508 #endif
3510 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3511 We do NOT enter this node in any sort of symbol table.
3513 layout_decl is used to set up the decl's storage layout.
3514 Other slots are initialized to 0 or null pointers. */
3516 tree
3517 build_decl (code, name, type)
3518 enum tree_code code;
3519 tree name, type;
3521 register tree t;
3523 t = make_node (code);
3525 /* if (type == error_mark_node)
3526 type = integer_type_node; */
3527 /* That is not done, deliberately, so that having error_mark_node
3528 as the type can suppress useless errors in the use of this variable. */
3530 DECL_NAME (t) = name;
3531 DECL_ASSEMBLER_NAME (t) = name;
3532 TREE_TYPE (t) = type;
3534 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3535 layout_decl (t, 0);
3536 else if (code == FUNCTION_DECL)
3537 DECL_MODE (t) = FUNCTION_MODE;
3539 return t;
3542 /* BLOCK nodes are used to represent the structure of binding contours
3543 and declarations, once those contours have been exited and their contents
3544 compiled. This information is used for outputting debugging info. */
3546 tree
3547 build_block (vars, tags, subblocks, supercontext, chain)
3548 tree vars, tags ATTRIBUTE_UNUSED, subblocks, supercontext, chain;
3550 register tree block = make_node (BLOCK);
3552 BLOCK_VARS (block) = vars;
3553 BLOCK_SUBBLOCKS (block) = subblocks;
3554 BLOCK_SUPERCONTEXT (block) = supercontext;
3555 BLOCK_CHAIN (block) = chain;
3556 return block;
3559 /* EXPR_WITH_FILE_LOCATION are used to keep track of the exact
3560 location where an expression or an identifier were encountered. It
3561 is necessary for languages where the frontend parser will handle
3562 recursively more than one file (Java is one of them). */
3564 tree
3565 build_expr_wfl (node, file, line, col)
3566 tree node;
3567 const char *file;
3568 int line, col;
3570 static const char *last_file = 0;
3571 static tree last_filenode = NULL_TREE;
3572 register tree wfl = make_node (EXPR_WITH_FILE_LOCATION);
3574 EXPR_WFL_NODE (wfl) = node;
3575 EXPR_WFL_SET_LINECOL (wfl, line, col);
3576 if (file != last_file)
3578 last_file = file;
3579 last_filenode = file ? get_identifier (file) : NULL_TREE;
3582 EXPR_WFL_FILENAME_NODE (wfl) = last_filenode;
3583 if (node)
3585 TREE_SIDE_EFFECTS (wfl) = TREE_SIDE_EFFECTS (node);
3586 TREE_TYPE (wfl) = TREE_TYPE (node);
3589 return wfl;
3592 /* Return a declaration like DDECL except that its DECL_MACHINE_ATTRIBUTE
3593 is ATTRIBUTE. */
3595 tree
3596 build_decl_attribute_variant (ddecl, attribute)
3597 tree ddecl, attribute;
3599 DECL_MACHINE_ATTRIBUTES (ddecl) = attribute;
3600 return ddecl;
3603 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3604 is ATTRIBUTE.
3606 Record such modified types already made so we don't make duplicates. */
3608 tree
3609 build_type_attribute_variant (ttype, attribute)
3610 tree ttype, attribute;
3612 if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3614 unsigned int hashcode;
3615 tree ntype;
3617 push_obstacks (TYPE_OBSTACK (ttype), TYPE_OBSTACK (ttype));
3618 ntype = copy_node (ttype);
3620 TYPE_POINTER_TO (ntype) = 0;
3621 TYPE_REFERENCE_TO (ntype) = 0;
3622 TYPE_ATTRIBUTES (ntype) = attribute;
3624 /* Create a new main variant of TYPE. */
3625 TYPE_MAIN_VARIANT (ntype) = ntype;
3626 TYPE_NEXT_VARIANT (ntype) = 0;
3627 set_type_quals (ntype, TYPE_UNQUALIFIED);
3629 hashcode = (TYPE_HASH (TREE_CODE (ntype))
3630 + TYPE_HASH (TREE_TYPE (ntype))
3631 + attribute_hash_list (attribute));
3633 switch (TREE_CODE (ntype))
3635 case FUNCTION_TYPE:
3636 hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype));
3637 break;
3638 case ARRAY_TYPE:
3639 hashcode += TYPE_HASH (TYPE_DOMAIN (ntype));
3640 break;
3641 case INTEGER_TYPE:
3642 hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype));
3643 break;
3644 case REAL_TYPE:
3645 hashcode += TYPE_HASH (TYPE_PRECISION (ntype));
3646 break;
3647 default:
3648 break;
3651 ntype = type_hash_canon (hashcode, ntype);
3652 ttype = build_qualified_type (ntype, TYPE_QUALS (ttype));
3653 pop_obstacks ();
3656 return ttype;
3659 /* Return a 1 if ATTR_NAME and ATTR_ARGS is valid for either declaration DECL
3660 or type TYPE and 0 otherwise. Validity is determined the configuration
3661 macros VALID_MACHINE_DECL_ATTRIBUTE and VALID_MACHINE_TYPE_ATTRIBUTE. */
3664 valid_machine_attribute (attr_name, attr_args, decl, type)
3665 tree attr_name;
3666 tree attr_args ATTRIBUTE_UNUSED;
3667 tree decl ATTRIBUTE_UNUSED;
3668 tree type ATTRIBUTE_UNUSED;
3670 int validated = 0;
3671 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3672 tree decl_attr_list = decl != 0 ? DECL_MACHINE_ATTRIBUTES (decl) : 0;
3673 #endif
3674 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3675 tree type_attr_list = TYPE_ATTRIBUTES (type);
3676 #endif
3678 if (TREE_CODE (attr_name) != IDENTIFIER_NODE)
3679 abort ();
3681 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3682 if (decl != 0
3683 && VALID_MACHINE_DECL_ATTRIBUTE (decl, decl_attr_list, attr_name,
3684 attr_args))
3686 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3687 decl_attr_list);
3689 if (attr != NULL_TREE)
3691 /* Override existing arguments. Declarations are unique so we can
3692 modify this in place. */
3693 TREE_VALUE (attr) = attr_args;
3695 else
3697 decl_attr_list = tree_cons (attr_name, attr_args, decl_attr_list);
3698 decl = build_decl_attribute_variant (decl, decl_attr_list);
3701 validated = 1;
3703 #endif
3705 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3706 if (validated)
3707 /* Don't apply the attribute to both the decl and the type. */;
3708 else if (VALID_MACHINE_TYPE_ATTRIBUTE (type, type_attr_list, attr_name,
3709 attr_args))
3711 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3712 type_attr_list);
3714 if (attr != NULL_TREE)
3716 /* Override existing arguments.
3717 ??? This currently works since attribute arguments are not
3718 included in `attribute_hash_list'. Something more complicated
3719 may be needed in the future. */
3720 TREE_VALUE (attr) = attr_args;
3722 else
3724 /* If this is part of a declaration, create a type variant,
3725 otherwise, this is part of a type definition, so add it
3726 to the base type. */
3727 type_attr_list = tree_cons (attr_name, attr_args, type_attr_list);
3728 if (decl != 0)
3729 type = build_type_attribute_variant (type, type_attr_list);
3730 else
3731 TYPE_ATTRIBUTES (type) = type_attr_list;
3734 if (decl != 0)
3735 TREE_TYPE (decl) = type;
3737 validated = 1;
3740 /* Handle putting a type attribute on pointer-to-function-type by putting
3741 the attribute on the function type. */
3742 else if (POINTER_TYPE_P (type)
3743 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3744 && VALID_MACHINE_TYPE_ATTRIBUTE (TREE_TYPE (type), type_attr_list,
3745 attr_name, attr_args))
3747 tree inner_type = TREE_TYPE (type);
3748 tree inner_attr_list = TYPE_ATTRIBUTES (inner_type);
3749 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3750 type_attr_list);
3752 if (attr != NULL_TREE)
3753 TREE_VALUE (attr) = attr_args;
3754 else
3756 inner_attr_list = tree_cons (attr_name, attr_args, inner_attr_list);
3757 inner_type = build_type_attribute_variant (inner_type,
3758 inner_attr_list);
3761 if (decl != 0)
3762 TREE_TYPE (decl) = build_pointer_type (inner_type);
3763 else
3765 /* Clear TYPE_POINTER_TO for the old inner type, since
3766 `type' won't be pointing to it anymore. */
3767 TYPE_POINTER_TO (TREE_TYPE (type)) = NULL_TREE;
3768 TREE_TYPE (type) = inner_type;
3771 validated = 1;
3773 #endif
3775 return validated;
3778 /* Return non-zero if IDENT is a valid name for attribute ATTR,
3779 or zero if not.
3781 We try both `text' and `__text__', ATTR may be either one. */
3782 /* ??? It might be a reasonable simplification to require ATTR to be only
3783 `text'. One might then also require attribute lists to be stored in
3784 their canonicalized form. */
3787 is_attribute_p (attr, ident)
3788 const char *attr;
3789 tree ident;
3791 int ident_len, attr_len;
3792 char *p;
3794 if (TREE_CODE (ident) != IDENTIFIER_NODE)
3795 return 0;
3797 if (strcmp (attr, IDENTIFIER_POINTER (ident)) == 0)
3798 return 1;
3800 p = IDENTIFIER_POINTER (ident);
3801 ident_len = strlen (p);
3802 attr_len = strlen (attr);
3804 /* If ATTR is `__text__', IDENT must be `text'; and vice versa. */
3805 if (attr[0] == '_')
3807 if (attr[1] != '_'
3808 || attr[attr_len - 2] != '_'
3809 || attr[attr_len - 1] != '_')
3810 abort ();
3811 if (ident_len == attr_len - 4
3812 && strncmp (attr + 2, p, attr_len - 4) == 0)
3813 return 1;
3815 else
3817 if (ident_len == attr_len + 4
3818 && p[0] == '_' && p[1] == '_'
3819 && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3820 && strncmp (attr, p + 2, attr_len) == 0)
3821 return 1;
3824 return 0;
3827 /* Given an attribute name and a list of attributes, return a pointer to the
3828 attribute's list element if the attribute is part of the list, or NULL_TREE
3829 if not found. */
3831 tree
3832 lookup_attribute (attr_name, list)
3833 const char *attr_name;
3834 tree list;
3836 tree l;
3838 for (l = list; l; l = TREE_CHAIN (l))
3840 if (TREE_CODE (TREE_PURPOSE (l)) != IDENTIFIER_NODE)
3841 abort ();
3842 if (is_attribute_p (attr_name, TREE_PURPOSE (l)))
3843 return l;
3846 return NULL_TREE;
3849 /* Return an attribute list that is the union of a1 and a2. */
3851 tree
3852 merge_attributes (a1, a2)
3853 register tree a1, a2;
3855 tree attributes;
3857 /* Either one unset? Take the set one. */
3859 if ((attributes = a1) == 0)
3860 attributes = a2;
3862 /* One that completely contains the other? Take it. */
3864 else if (a2 != 0 && ! attribute_list_contained (a1, a2))
3866 if (attribute_list_contained (a2, a1))
3867 attributes = a2;
3868 else
3870 /* Pick the longest list, and hang on the other list. */
3871 /* ??? For the moment we punt on the issue of attrs with args. */
3873 if (list_length (a1) < list_length (a2))
3874 attributes = a2, a2 = a1;
3876 for (; a2 != 0; a2 = TREE_CHAIN (a2))
3877 if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3878 attributes) == NULL_TREE)
3880 a1 = copy_node (a2);
3881 TREE_CHAIN (a1) = attributes;
3882 attributes = a1;
3886 return attributes;
3889 /* Given types T1 and T2, merge their attributes and return
3890 the result. */
3892 tree
3893 merge_machine_type_attributes (t1, t2)
3894 tree t1, t2;
3896 #ifdef MERGE_MACHINE_TYPE_ATTRIBUTES
3897 return MERGE_MACHINE_TYPE_ATTRIBUTES (t1, t2);
3898 #else
3899 return merge_attributes (TYPE_ATTRIBUTES (t1),
3900 TYPE_ATTRIBUTES (t2));
3901 #endif
3904 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3905 the result. */
3907 tree
3908 merge_machine_decl_attributes (olddecl, newdecl)
3909 tree olddecl, newdecl;
3911 #ifdef MERGE_MACHINE_DECL_ATTRIBUTES
3912 return MERGE_MACHINE_DECL_ATTRIBUTES (olddecl, newdecl);
3913 #else
3914 return merge_attributes (DECL_MACHINE_ATTRIBUTES (olddecl),
3915 DECL_MACHINE_ATTRIBUTES (newdecl));
3916 #endif
3919 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
3920 of the various TYPE_QUAL values. */
3922 static void
3923 set_type_quals (type, type_quals)
3924 tree type;
3925 int type_quals;
3927 TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
3928 TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
3929 TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
3932 /* Given a type node TYPE and a TYPE_QUALIFIER_SET, return a type for
3933 the same kind of data as TYPE describes. Variants point to the
3934 "main variant" (which has no qualifiers set) via TYPE_MAIN_VARIANT,
3935 and it points to a chain of other variants so that duplicate
3936 variants are never made. Only main variants should ever appear as
3937 types of expressions. */
3939 tree
3940 build_qualified_type (type, type_quals)
3941 tree type;
3942 int type_quals;
3944 register tree t;
3946 /* Search the chain of variants to see if there is already one there just
3947 like the one we need to have. If so, use that existing one. We must
3948 preserve the TYPE_NAME, since there is code that depends on this. */
3950 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3951 if (TYPE_QUALS (t) == type_quals && TYPE_NAME (t) == TYPE_NAME (type))
3952 return t;
3954 /* We need a new one. */
3955 t = build_type_copy (type);
3956 set_type_quals (t, type_quals);
3957 return t;
3960 /* Create a new variant of TYPE, equivalent but distinct.
3961 This is so the caller can modify it. */
3963 tree
3964 build_type_copy (type)
3965 tree type;
3967 register tree t, m = TYPE_MAIN_VARIANT (type);
3968 register struct obstack *ambient_obstack = current_obstack;
3970 current_obstack = TYPE_OBSTACK (type);
3971 t = copy_node (type);
3972 current_obstack = ambient_obstack;
3974 TYPE_POINTER_TO (t) = 0;
3975 TYPE_REFERENCE_TO (t) = 0;
3977 /* Add this type to the chain of variants of TYPE. */
3978 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
3979 TYPE_NEXT_VARIANT (m) = t;
3981 return t;
3984 /* Hashing of types so that we don't make duplicates.
3985 The entry point is `type_hash_canon'. */
3987 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
3988 with types in the TREE_VALUE slots), by adding the hash codes
3989 of the individual types. */
3991 unsigned int
3992 type_hash_list (list)
3993 tree list;
3995 unsigned int hashcode;
3996 register tree tail;
3998 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3999 hashcode += TYPE_HASH (TREE_VALUE (tail));
4001 return hashcode;
4004 /* These are the Hashtable callback functions. */
4006 /* Returns true if the types are equal. */
4008 static int
4009 type_hash_eq (va, vb)
4010 const void *va;
4011 const void *vb;
4013 const struct type_hash *a = va, *b = vb;
4014 if (a->hash == b->hash
4015 && TREE_CODE (a->type) == TREE_CODE (b->type)
4016 && TREE_TYPE (a->type) == TREE_TYPE (b->type)
4017 && attribute_list_equal (TYPE_ATTRIBUTES (a->type),
4018 TYPE_ATTRIBUTES (b->type))
4019 && TYPE_ALIGN (a->type) == TYPE_ALIGN (b->type)
4020 && (TYPE_MAX_VALUE (a->type) == TYPE_MAX_VALUE (b->type)
4021 || tree_int_cst_equal (TYPE_MAX_VALUE (a->type),
4022 TYPE_MAX_VALUE (b->type)))
4023 && (TYPE_MIN_VALUE (a->type) == TYPE_MIN_VALUE (b->type)
4024 || tree_int_cst_equal (TYPE_MIN_VALUE (a->type),
4025 TYPE_MIN_VALUE (b->type)))
4026 /* Note that TYPE_DOMAIN is TYPE_ARG_TYPES for FUNCTION_TYPE. */
4027 && (TYPE_DOMAIN (a->type) == TYPE_DOMAIN (b->type)
4028 || (TYPE_DOMAIN (a->type)
4029 && TREE_CODE (TYPE_DOMAIN (a->type)) == TREE_LIST
4030 && TYPE_DOMAIN (b->type)
4031 && TREE_CODE (TYPE_DOMAIN (b->type)) == TREE_LIST
4032 && type_list_equal (TYPE_DOMAIN (a->type),
4033 TYPE_DOMAIN (b->type)))))
4034 return 1;
4035 return 0;
4038 /* Return the cached hash value. */
4040 static unsigned int
4041 type_hash_hash (item)
4042 const void *item;
4044 return ((const struct type_hash*)item)->hash;
4047 /* Look in the type hash table for a type isomorphic to TYPE.
4048 If one is found, return it. Otherwise return 0. */
4050 tree
4051 type_hash_lookup (hashcode, type)
4052 unsigned int hashcode;
4053 tree type;
4055 struct type_hash *h, in;
4057 /* The TYPE_ALIGN field of a type is set by layout_type(), so we
4058 must call that routine before comparing TYPE_ALIGNs. */
4059 layout_type (type);
4061 in.hash = hashcode;
4062 in.type = type;
4064 h = htab_find_with_hash (type_hash_table, &in, hashcode);
4065 if (h)
4066 return h->type;
4067 return NULL_TREE;
4070 /* Add an entry to the type-hash-table
4071 for a type TYPE whose hash code is HASHCODE. */
4073 void
4074 type_hash_add (hashcode, type)
4075 unsigned int hashcode;
4076 tree type;
4078 struct type_hash *h;
4079 void **loc;
4081 h = (struct type_hash *) permalloc (sizeof (struct type_hash));
4082 h->hash = hashcode;
4083 h->type = type;
4084 loc = htab_find_slot_with_hash (type_hash_table, h, hashcode, INSERT);
4085 *(struct type_hash**) loc = h;
4088 /* Given TYPE, and HASHCODE its hash code, return the canonical
4089 object for an identical type if one already exists.
4090 Otherwise, return TYPE, and record it as the canonical object
4091 if it is a permanent object.
4093 To use this function, first create a type of the sort you want.
4094 Then compute its hash code from the fields of the type that
4095 make it different from other similar types.
4096 Then call this function and use the value.
4097 This function frees the type you pass in if it is a duplicate. */
4099 /* Set to 1 to debug without canonicalization. Never set by program. */
4100 int debug_no_type_hash = 0;
4102 tree
4103 type_hash_canon (hashcode, type)
4104 unsigned int hashcode;
4105 tree type;
4107 tree t1;
4109 if (debug_no_type_hash)
4110 return type;
4112 t1 = type_hash_lookup (hashcode, type);
4113 if (t1 != 0)
4115 if (!ggc_p)
4116 obstack_free (TYPE_OBSTACK (type), type);
4118 #ifdef GATHER_STATISTICS
4119 tree_node_counts[(int) t_kind]--;
4120 tree_node_sizes[(int) t_kind] -= sizeof (struct tree_type);
4121 #endif
4122 return t1;
4125 /* If this is a permanent type, record it for later reuse. */
4126 if (ggc_p || TREE_PERMANENT (type))
4127 type_hash_add (hashcode, type);
4129 return type;
4132 /* Callback function for htab_traverse. */
4134 static int
4135 mark_hash_entry (entry, param)
4136 void **entry;
4137 void *param ATTRIBUTE_UNUSED;
4139 struct type_hash *p = *(struct type_hash **)entry;
4141 ggc_mark_tree (p->type);
4143 /* Continue scan. */
4144 return 1;
4147 /* Mark ARG (which is really a htab_t *) for GC. */
4149 static void
4150 mark_type_hash (arg)
4151 void *arg;
4153 htab_t t = *(htab_t *) arg;
4155 htab_traverse (t, mark_hash_entry, 0);
4158 static void
4159 print_type_hash_statistics ()
4161 fprintf (stderr, "Type hash: size %ld, %ld elements, %f collisions\n",
4162 (long) htab_size (type_hash_table),
4163 (long) htab_elements (type_hash_table),
4164 htab_collisions (type_hash_table));
4167 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
4168 with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
4169 by adding the hash codes of the individual attributes. */
4171 unsigned int
4172 attribute_hash_list (list)
4173 tree list;
4175 unsigned int hashcode;
4176 register tree tail;
4178 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
4179 /* ??? Do we want to add in TREE_VALUE too? */
4180 hashcode += TYPE_HASH (TREE_PURPOSE (tail));
4181 return hashcode;
4184 /* Given two lists of attributes, return true if list l2 is
4185 equivalent to l1. */
4188 attribute_list_equal (l1, l2)
4189 tree l1, l2;
4191 return attribute_list_contained (l1, l2)
4192 && attribute_list_contained (l2, l1);
4195 /* Given two lists of attributes, return true if list L2 is
4196 completely contained within L1. */
4197 /* ??? This would be faster if attribute names were stored in a canonicalized
4198 form. Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
4199 must be used to show these elements are equivalent (which they are). */
4200 /* ??? It's not clear that attributes with arguments will always be handled
4201 correctly. */
4204 attribute_list_contained (l1, l2)
4205 tree l1, l2;
4207 register tree t1, t2;
4209 /* First check the obvious, maybe the lists are identical. */
4210 if (l1 == l2)
4211 return 1;
4213 /* Maybe the lists are similar. */
4214 for (t1 = l1, t2 = l2;
4215 t1 != 0 && t2 != 0
4216 && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
4217 && TREE_VALUE (t1) == TREE_VALUE (t2);
4218 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
4220 /* Maybe the lists are equal. */
4221 if (t1 == 0 && t2 == 0)
4222 return 1;
4224 for (; t2 != 0; t2 = TREE_CHAIN (t2))
4226 tree attr
4227 = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)), l1);
4229 if (attr == 0)
4230 return 0;
4232 if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) != 1)
4233 return 0;
4236 return 1;
4239 /* Given two lists of types
4240 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
4241 return 1 if the lists contain the same types in the same order.
4242 Also, the TREE_PURPOSEs must match. */
4245 type_list_equal (l1, l2)
4246 tree l1, l2;
4248 register tree t1, t2;
4250 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
4251 if (TREE_VALUE (t1) != TREE_VALUE (t2)
4252 || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
4253 && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
4254 && (TREE_TYPE (TREE_PURPOSE (t1))
4255 == TREE_TYPE (TREE_PURPOSE (t2))))))
4256 return 0;
4258 return t1 == t2;
4261 /* Nonzero if integer constants T1 and T2
4262 represent the same constant value. */
4265 tree_int_cst_equal (t1, t2)
4266 tree t1, t2;
4268 if (t1 == t2)
4269 return 1;
4271 if (t1 == 0 || t2 == 0)
4272 return 0;
4274 if (TREE_CODE (t1) == INTEGER_CST
4275 && TREE_CODE (t2) == INTEGER_CST
4276 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
4277 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
4278 return 1;
4280 return 0;
4283 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
4284 The precise way of comparison depends on their data type. */
4287 tree_int_cst_lt (t1, t2)
4288 tree t1, t2;
4290 if (t1 == t2)
4291 return 0;
4293 if (! TREE_UNSIGNED (TREE_TYPE (t1)))
4294 return INT_CST_LT (t1, t2);
4296 return INT_CST_LT_UNSIGNED (t1, t2);
4299 /* Return 1 if T is an INTEGER_CST that can be represented in a single
4300 HOST_WIDE_INT value. If POS is nonzero, the result must be positive. */
4303 host_integerp (t, pos)
4304 tree t;
4305 int pos;
4307 return (TREE_CODE (t) == INTEGER_CST
4308 && ! TREE_OVERFLOW (t)
4309 && ((TREE_INT_CST_HIGH (t) == 0
4310 && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) >= 0)
4311 || (! pos && TREE_INT_CST_HIGH (t) == -1
4312 && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0)));
4315 /* Return the HOST_WIDE_INT least significant bits of T if it is an
4316 INTEGER_CST and there is no overflow. POS is nonzero if the result must
4317 be positive. Abort if we cannot satisfy the above conditions. */
4319 HOST_WIDE_INT
4320 tree_low_cst (t, pos)
4321 tree t;
4322 int pos;
4324 if (host_integerp (t, pos))
4325 return TREE_INT_CST_LOW (t);
4326 else
4327 abort ();
4330 /* Return the most significant bit of the integer constant T. */
4333 tree_int_cst_msb (t)
4334 tree t;
4336 register int prec;
4337 HOST_WIDE_INT h;
4338 unsigned HOST_WIDE_INT l;
4340 /* Note that using TYPE_PRECISION here is wrong. We care about the
4341 actual bits, not the (arbitrary) range of the type. */
4342 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (t))) - 1;
4343 rshift_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t), prec,
4344 2 * HOST_BITS_PER_WIDE_INT, &l, &h, 0);
4345 return (l & 1) == 1;
4348 /* Return an indication of the sign of the integer constant T.
4349 The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
4350 Note that -1 will never be returned it T's type is unsigned. */
4353 tree_int_cst_sgn (t)
4354 tree t;
4356 if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
4357 return 0;
4358 else if (TREE_UNSIGNED (TREE_TYPE (t)))
4359 return 1;
4360 else if (TREE_INT_CST_HIGH (t) < 0)
4361 return -1;
4362 else
4363 return 1;
4366 /* Return true if `t' is known to be non-negative. */
4369 tree_expr_nonnegative_p (t)
4370 tree t;
4372 switch (TREE_CODE (t))
4374 case INTEGER_CST:
4375 return tree_int_cst_sgn (t) >= 0;
4376 case COND_EXPR:
4377 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
4378 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
4379 default:
4380 /* We don't know sign of `t', so be safe and return false. */
4381 return 0;
4385 /* Compare two constructor-element-type constants. Return 1 if the lists
4386 are known to be equal; otherwise return 0. */
4389 simple_cst_list_equal (l1, l2)
4390 tree l1, l2;
4392 while (l1 != NULL_TREE && l2 != NULL_TREE)
4394 if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
4395 return 0;
4397 l1 = TREE_CHAIN (l1);
4398 l2 = TREE_CHAIN (l2);
4401 return l1 == l2;
4404 /* Return truthvalue of whether T1 is the same tree structure as T2.
4405 Return 1 if they are the same.
4406 Return 0 if they are understandably different.
4407 Return -1 if either contains tree structure not understood by
4408 this function. */
4411 simple_cst_equal (t1, t2)
4412 tree t1, t2;
4414 register enum tree_code code1, code2;
4415 int cmp;
4416 int i;
4418 if (t1 == t2)
4419 return 1;
4420 if (t1 == 0 || t2 == 0)
4421 return 0;
4423 code1 = TREE_CODE (t1);
4424 code2 = TREE_CODE (t2);
4426 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
4428 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
4429 || code2 == NON_LVALUE_EXPR)
4430 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4431 else
4432 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
4435 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
4436 || code2 == NON_LVALUE_EXPR)
4437 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
4439 if (code1 != code2)
4440 return 0;
4442 switch (code1)
4444 case INTEGER_CST:
4445 return (TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
4446 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2));
4448 case REAL_CST:
4449 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
4451 case STRING_CST:
4452 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
4453 && ! bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
4454 TREE_STRING_LENGTH (t1)));
4456 case CONSTRUCTOR:
4457 if (CONSTRUCTOR_ELTS (t1) == CONSTRUCTOR_ELTS (t2))
4458 return 1;
4459 else
4460 abort ();
4462 case SAVE_EXPR:
4463 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4465 case CALL_EXPR:
4466 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4467 if (cmp <= 0)
4468 return cmp;
4469 return
4470 simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
4472 case TARGET_EXPR:
4473 /* Special case: if either target is an unallocated VAR_DECL,
4474 it means that it's going to be unified with whatever the
4475 TARGET_EXPR is really supposed to initialize, so treat it
4476 as being equivalent to anything. */
4477 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
4478 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
4479 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
4480 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
4481 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
4482 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
4483 cmp = 1;
4484 else
4485 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4487 if (cmp <= 0)
4488 return cmp;
4490 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
4492 case WITH_CLEANUP_EXPR:
4493 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4494 if (cmp <= 0)
4495 return cmp;
4497 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
4499 case COMPONENT_REF:
4500 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
4501 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4503 return 0;
4505 case VAR_DECL:
4506 case PARM_DECL:
4507 case CONST_DECL:
4508 case FUNCTION_DECL:
4509 return 0;
4511 default:
4512 break;
4515 /* This general rule works for most tree codes. All exceptions should be
4516 handled above. If this is a language-specific tree code, we can't
4517 trust what might be in the operand, so say we don't know
4518 the situation. */
4519 if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
4520 return -1;
4522 switch (TREE_CODE_CLASS (code1))
4524 case '1':
4525 case '2':
4526 case '<':
4527 case 'e':
4528 case 'r':
4529 case 's':
4530 cmp = 1;
4531 for (i = 0; i < tree_code_length[(int) code1]; i++)
4533 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
4534 if (cmp <= 0)
4535 return cmp;
4538 return cmp;
4540 default:
4541 return -1;
4545 /* Compare the value of T, an INTEGER_CST, with U, an unsigned integer value.
4546 Return -1, 0, or 1 if the value of T is less than, equal to, or greater
4547 than U, respectively. */
4550 compare_tree_int (t, u)
4551 tree t;
4552 unsigned int u;
4554 if (tree_int_cst_sgn (t) < 0)
4555 return -1;
4556 else if (TREE_INT_CST_HIGH (t) != 0)
4557 return 1;
4558 else if (TREE_INT_CST_LOW (t) == u)
4559 return 0;
4560 else if (TREE_INT_CST_LOW (t) < u)
4561 return -1;
4562 else
4563 return 1;
4566 /* Constructors for pointer, array and function types.
4567 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
4568 constructed by language-dependent code, not here.) */
4570 /* Construct, lay out and return the type of pointers to TO_TYPE.
4571 If such a type has already been constructed, reuse it. */
4573 tree
4574 build_pointer_type (to_type)
4575 tree to_type;
4577 register tree t = TYPE_POINTER_TO (to_type);
4579 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4581 if (t != 0)
4582 return t;
4584 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4585 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4586 t = make_node (POINTER_TYPE);
4587 pop_obstacks ();
4589 TREE_TYPE (t) = to_type;
4591 /* Record this type as the pointer to TO_TYPE. */
4592 TYPE_POINTER_TO (to_type) = t;
4594 /* Lay out the type. This function has many callers that are concerned
4595 with expression-construction, and this simplifies them all.
4596 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
4597 layout_type (t);
4599 return t;
4602 /* Build the node for the type of references-to-TO_TYPE. */
4604 tree
4605 build_reference_type (to_type)
4606 tree to_type;
4608 register tree t = TYPE_REFERENCE_TO (to_type);
4610 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4612 if (t)
4613 return t;
4615 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4616 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4617 t = make_node (REFERENCE_TYPE);
4618 pop_obstacks ();
4620 TREE_TYPE (t) = to_type;
4622 /* Record this type as the pointer to TO_TYPE. */
4623 TYPE_REFERENCE_TO (to_type) = t;
4625 layout_type (t);
4627 return t;
4630 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
4631 MAXVAL should be the maximum value in the domain
4632 (one less than the length of the array).
4634 The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
4635 We don't enforce this limit, that is up to caller (e.g. language front end).
4636 The limit exists because the result is a signed type and we don't handle
4637 sizes that use more than one HOST_WIDE_INT. */
4639 tree
4640 build_index_type (maxval)
4641 tree maxval;
4643 register tree itype = make_node (INTEGER_TYPE);
4645 TREE_TYPE (itype) = sizetype;
4646 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
4647 TYPE_MIN_VALUE (itype) = size_zero_node;
4649 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4650 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
4651 pop_obstacks ();
4653 TYPE_MODE (itype) = TYPE_MODE (sizetype);
4654 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
4655 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
4656 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
4658 if (host_integerp (maxval, 1))
4659 return type_hash_canon (tree_low_cst (maxval, 1), itype);
4660 else
4661 return itype;
4664 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
4665 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
4666 low bound LOWVAL and high bound HIGHVAL.
4667 if TYPE==NULL_TREE, sizetype is used. */
4669 tree
4670 build_range_type (type, lowval, highval)
4671 tree type, lowval, highval;
4673 register tree itype = make_node (INTEGER_TYPE);
4675 TREE_TYPE (itype) = type;
4676 if (type == NULL_TREE)
4677 type = sizetype;
4679 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4680 TYPE_MIN_VALUE (itype) = convert (type, lowval);
4681 TYPE_MAX_VALUE (itype) = highval ? convert (type, highval) : NULL;
4682 pop_obstacks ();
4684 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
4685 TYPE_MODE (itype) = TYPE_MODE (type);
4686 TYPE_SIZE (itype) = TYPE_SIZE (type);
4687 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
4688 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
4690 if (host_integerp (lowval, 0) && highval != 0 && host_integerp (highval, 0))
4691 return type_hash_canon (tree_low_cst (highval, 0)
4692 - tree_low_cst (lowval, 0),
4693 itype);
4694 else
4695 return itype;
4698 /* Just like build_index_type, but takes lowval and highval instead
4699 of just highval (maxval). */
4701 tree
4702 build_index_2_type (lowval,highval)
4703 tree lowval, highval;
4705 return build_range_type (sizetype, lowval, highval);
4708 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
4709 Needed because when index types are not hashed, equal index types
4710 built at different times appear distinct, even though structurally,
4711 they are not. */
4714 index_type_equal (itype1, itype2)
4715 tree itype1, itype2;
4717 if (TREE_CODE (itype1) != TREE_CODE (itype2))
4718 return 0;
4720 if (TREE_CODE (itype1) == INTEGER_TYPE)
4722 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
4723 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
4724 || simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2)) != 1
4725 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
4726 return 0;
4728 if (1 == simple_cst_equal (TYPE_MIN_VALUE (itype1),
4729 TYPE_MIN_VALUE (itype2))
4730 && 1 == simple_cst_equal (TYPE_MAX_VALUE (itype1),
4731 TYPE_MAX_VALUE (itype2)))
4732 return 1;
4735 return 0;
4738 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
4739 and number of elements specified by the range of values of INDEX_TYPE.
4740 If such a type has already been constructed, reuse it. */
4742 tree
4743 build_array_type (elt_type, index_type)
4744 tree elt_type, index_type;
4746 register tree t;
4747 unsigned int hashcode;
4749 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
4751 error ("arrays of functions are not meaningful");
4752 elt_type = integer_type_node;
4755 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
4756 build_pointer_type (elt_type);
4758 /* Allocate the array after the pointer type,
4759 in case we free it in type_hash_canon. */
4760 t = make_node (ARRAY_TYPE);
4761 TREE_TYPE (t) = elt_type;
4762 TYPE_DOMAIN (t) = index_type;
4764 if (index_type == 0)
4766 return t;
4769 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
4770 t = type_hash_canon (hashcode, t);
4772 if (!COMPLETE_TYPE_P (t))
4773 layout_type (t);
4774 return t;
4777 /* Return the TYPE of the elements comprising
4778 the innermost dimension of ARRAY. */
4780 tree
4781 get_inner_array_type (array)
4782 tree array;
4784 tree type = TREE_TYPE (array);
4786 while (TREE_CODE (type) == ARRAY_TYPE)
4787 type = TREE_TYPE (type);
4789 return type;
4792 /* Construct, lay out and return
4793 the type of functions returning type VALUE_TYPE
4794 given arguments of types ARG_TYPES.
4795 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
4796 are data type nodes for the arguments of the function.
4797 If such a type has already been constructed, reuse it. */
4799 tree
4800 build_function_type (value_type, arg_types)
4801 tree value_type, arg_types;
4803 register tree t;
4804 unsigned int hashcode;
4806 if (TREE_CODE (value_type) == FUNCTION_TYPE)
4808 error ("function return type cannot be function");
4809 value_type = integer_type_node;
4812 /* Make a node of the sort we want. */
4813 t = make_node (FUNCTION_TYPE);
4814 TREE_TYPE (t) = value_type;
4815 TYPE_ARG_TYPES (t) = arg_types;
4817 /* If we already have such a type, use the old one and free this one. */
4818 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
4819 t = type_hash_canon (hashcode, t);
4821 if (!COMPLETE_TYPE_P (t))
4822 layout_type (t);
4823 return t;
4826 /* Construct, lay out and return the type of methods belonging to class
4827 BASETYPE and whose arguments and values are described by TYPE.
4828 If that type exists already, reuse it.
4829 TYPE must be a FUNCTION_TYPE node. */
4831 tree
4832 build_method_type (basetype, type)
4833 tree basetype, type;
4835 register tree t;
4836 unsigned int hashcode;
4838 /* Make a node of the sort we want. */
4839 t = make_node (METHOD_TYPE);
4841 if (TREE_CODE (type) != FUNCTION_TYPE)
4842 abort ();
4844 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4845 TREE_TYPE (t) = TREE_TYPE (type);
4847 /* The actual arglist for this function includes a "hidden" argument
4848 which is "this". Put it into the list of argument types. */
4850 TYPE_ARG_TYPES (t)
4851 = tree_cons (NULL_TREE,
4852 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
4854 /* If we already have such a type, use the old one and free this one. */
4855 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4856 t = type_hash_canon (hashcode, t);
4858 if (!COMPLETE_TYPE_P (t))
4859 layout_type (t);
4861 return t;
4864 /* Construct, lay out and return the type of offsets to a value
4865 of type TYPE, within an object of type BASETYPE.
4866 If a suitable offset type exists already, reuse it. */
4868 tree
4869 build_offset_type (basetype, type)
4870 tree basetype, type;
4872 register tree t;
4873 unsigned int hashcode;
4875 /* Make a node of the sort we want. */
4876 t = make_node (OFFSET_TYPE);
4878 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4879 TREE_TYPE (t) = type;
4881 /* If we already have such a type, use the old one and free this one. */
4882 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4883 t = type_hash_canon (hashcode, t);
4885 if (!COMPLETE_TYPE_P (t))
4886 layout_type (t);
4888 return t;
4891 /* Create a complex type whose components are COMPONENT_TYPE. */
4893 tree
4894 build_complex_type (component_type)
4895 tree component_type;
4897 register tree t;
4898 unsigned int hashcode;
4900 /* Make a node of the sort we want. */
4901 t = make_node (COMPLEX_TYPE);
4903 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
4904 set_type_quals (t, TYPE_QUALS (component_type));
4906 /* If we already have such a type, use the old one and free this one. */
4907 hashcode = TYPE_HASH (component_type);
4908 t = type_hash_canon (hashcode, t);
4910 if (!COMPLETE_TYPE_P (t))
4911 layout_type (t);
4913 /* If we are writing Dwarf2 output we need to create a name,
4914 since complex is a fundamental type. */
4915 if (write_symbols == DWARF2_DEBUG && ! TYPE_NAME (t))
4917 const char *name;
4918 if (component_type == char_type_node)
4919 name = "complex char";
4920 else if (component_type == signed_char_type_node)
4921 name = "complex signed char";
4922 else if (component_type == unsigned_char_type_node)
4923 name = "complex unsigned char";
4924 else if (component_type == short_integer_type_node)
4925 name = "complex short int";
4926 else if (component_type == short_unsigned_type_node)
4927 name = "complex short unsigned int";
4928 else if (component_type == integer_type_node)
4929 name = "complex int";
4930 else if (component_type == unsigned_type_node)
4931 name = "complex unsigned int";
4932 else if (component_type == long_integer_type_node)
4933 name = "complex long int";
4934 else if (component_type == long_unsigned_type_node)
4935 name = "complex long unsigned int";
4936 else if (component_type == long_long_integer_type_node)
4937 name = "complex long long int";
4938 else if (component_type == long_long_unsigned_type_node)
4939 name = "complex long long unsigned int";
4940 else
4941 name = 0;
4943 if (name != 0)
4944 TYPE_NAME (t) = get_identifier (name);
4947 return t;
4950 /* Return OP, stripped of any conversions to wider types as much as is safe.
4951 Converting the value back to OP's type makes a value equivalent to OP.
4953 If FOR_TYPE is nonzero, we return a value which, if converted to
4954 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
4956 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
4957 narrowest type that can hold the value, even if they don't exactly fit.
4958 Otherwise, bit-field references are changed to a narrower type
4959 only if they can be fetched directly from memory in that type.
4961 OP must have integer, real or enumeral type. Pointers are not allowed!
4963 There are some cases where the obvious value we could return
4964 would regenerate to OP if converted to OP's type,
4965 but would not extend like OP to wider types.
4966 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
4967 For example, if OP is (unsigned short)(signed char)-1,
4968 we avoid returning (signed char)-1 if FOR_TYPE is int,
4969 even though extending that to an unsigned short would regenerate OP,
4970 since the result of extending (signed char)-1 to (int)
4971 is different from (int) OP. */
4973 tree
4974 get_unwidened (op, for_type)
4975 register tree op;
4976 tree for_type;
4978 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
4979 register tree type = TREE_TYPE (op);
4980 register unsigned final_prec
4981 = TYPE_PRECISION (for_type != 0 ? for_type : type);
4982 register int uns
4983 = (for_type != 0 && for_type != type
4984 && final_prec > TYPE_PRECISION (type)
4985 && TREE_UNSIGNED (type));
4986 register tree win = op;
4988 while (TREE_CODE (op) == NOP_EXPR)
4990 register int bitschange
4991 = TYPE_PRECISION (TREE_TYPE (op))
4992 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4994 /* Truncations are many-one so cannot be removed.
4995 Unless we are later going to truncate down even farther. */
4996 if (bitschange < 0
4997 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
4998 break;
5000 /* See what's inside this conversion. If we decide to strip it,
5001 we will set WIN. */
5002 op = TREE_OPERAND (op, 0);
5004 /* If we have not stripped any zero-extensions (uns is 0),
5005 we can strip any kind of extension.
5006 If we have previously stripped a zero-extension,
5007 only zero-extensions can safely be stripped.
5008 Any extension can be stripped if the bits it would produce
5009 are all going to be discarded later by truncating to FOR_TYPE. */
5011 if (bitschange > 0)
5013 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
5014 win = op;
5015 /* TREE_UNSIGNED says whether this is a zero-extension.
5016 Let's avoid computing it if it does not affect WIN
5017 and if UNS will not be needed again. */
5018 if ((uns || TREE_CODE (op) == NOP_EXPR)
5019 && TREE_UNSIGNED (TREE_TYPE (op)))
5021 uns = 1;
5022 win = op;
5027 if (TREE_CODE (op) == COMPONENT_REF
5028 /* Since type_for_size always gives an integer type. */
5029 && TREE_CODE (type) != REAL_TYPE
5030 /* Don't crash if field not laid out yet. */
5031 && DECL_SIZE (TREE_OPERAND (op, 1)) != 0)
5033 unsigned int innerprec
5034 = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
5036 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
5038 /* We can get this structure field in the narrowest type it fits in.
5039 If FOR_TYPE is 0, do this only for a field that matches the
5040 narrower type exactly and is aligned for it
5041 The resulting extension to its nominal type (a fullword type)
5042 must fit the same conditions as for other extensions. */
5044 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
5045 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
5046 && (! uns || final_prec <= innerprec
5047 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
5048 && type != 0)
5050 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
5051 TREE_OPERAND (op, 1));
5052 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
5053 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
5056 return win;
5059 /* Return OP or a simpler expression for a narrower value
5060 which can be sign-extended or zero-extended to give back OP.
5061 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
5062 or 0 if the value should be sign-extended. */
5064 tree
5065 get_narrower (op, unsignedp_ptr)
5066 register tree op;
5067 int *unsignedp_ptr;
5069 register int uns = 0;
5070 int first = 1;
5071 register tree win = op;
5073 while (TREE_CODE (op) == NOP_EXPR)
5075 register int bitschange
5076 = (TYPE_PRECISION (TREE_TYPE (op))
5077 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))));
5079 /* Truncations are many-one so cannot be removed. */
5080 if (bitschange < 0)
5081 break;
5083 /* See what's inside this conversion. If we decide to strip it,
5084 we will set WIN. */
5085 op = TREE_OPERAND (op, 0);
5087 if (bitschange > 0)
5089 /* An extension: the outermost one can be stripped,
5090 but remember whether it is zero or sign extension. */
5091 if (first)
5092 uns = TREE_UNSIGNED (TREE_TYPE (op));
5093 /* Otherwise, if a sign extension has been stripped,
5094 only sign extensions can now be stripped;
5095 if a zero extension has been stripped, only zero-extensions. */
5096 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
5097 break;
5098 first = 0;
5100 else /* bitschange == 0 */
5102 /* A change in nominal type can always be stripped, but we must
5103 preserve the unsignedness. */
5104 if (first)
5105 uns = TREE_UNSIGNED (TREE_TYPE (op));
5106 first = 0;
5109 win = op;
5112 if (TREE_CODE (op) == COMPONENT_REF
5113 /* Since type_for_size always gives an integer type. */
5114 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
5116 unsigned int innerprec
5117 = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
5119 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
5121 /* We can get this structure field in a narrower type that fits it,
5122 but the resulting extension to its nominal type (a fullword type)
5123 must satisfy the same conditions as for other extensions.
5125 Do this only for fields that are aligned (not bit-fields),
5126 because when bit-field insns will be used there is no
5127 advantage in doing this. */
5129 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
5130 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
5131 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
5132 && type != 0)
5134 if (first)
5135 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
5136 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
5137 TREE_OPERAND (op, 1));
5138 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
5139 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
5142 *unsignedp_ptr = uns;
5143 return win;
5146 /* Nonzero if integer constant C has a value that is permissible
5147 for type TYPE (an INTEGER_TYPE). */
5150 int_fits_type_p (c, type)
5151 tree c, type;
5153 if (TREE_UNSIGNED (type))
5154 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
5155 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
5156 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
5157 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
5158 /* Negative ints never fit unsigned types. */
5159 && ! (TREE_INT_CST_HIGH (c) < 0
5160 && ! TREE_UNSIGNED (TREE_TYPE (c))));
5161 else
5162 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
5163 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
5164 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
5165 && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
5166 /* Unsigned ints with top bit set never fit signed types. */
5167 && ! (TREE_INT_CST_HIGH (c) < 0
5168 && TREE_UNSIGNED (TREE_TYPE (c))));
5171 /* Given a DECL or TYPE, return the scope in which it was declared, or
5172 NULL_TREE if there is no containing scope. */
5174 tree
5175 get_containing_scope (t)
5176 tree t;
5178 return (TYPE_P (t) ? TYPE_CONTEXT (t) : DECL_CONTEXT (t));
5181 /* Return the innermost context enclosing DECL that is
5182 a FUNCTION_DECL, or zero if none. */
5184 tree
5185 decl_function_context (decl)
5186 tree decl;
5188 tree context;
5190 if (TREE_CODE (decl) == ERROR_MARK)
5191 return 0;
5193 if (TREE_CODE (decl) == SAVE_EXPR)
5194 context = SAVE_EXPR_CONTEXT (decl);
5196 /* C++ virtual functions use DECL_CONTEXT for the class of the vtable
5197 where we look up the function at runtime. Such functions always take
5198 a first argument of type 'pointer to real context'.
5200 C++ should really be fixed to use DECL_CONTEXT for the real context,
5201 and use something else for the "virtual context". */
5202 else if (TREE_CODE (decl) == FUNCTION_DECL && DECL_VINDEX (decl))
5203 context
5204 = TYPE_MAIN_VARIANT
5205 (TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (decl)))));
5206 else
5207 context = DECL_CONTEXT (decl);
5209 while (context && TREE_CODE (context) != FUNCTION_DECL)
5211 if (TREE_CODE (context) == BLOCK)
5212 context = BLOCK_SUPERCONTEXT (context);
5213 else
5214 context = get_containing_scope (context);
5217 return context;
5220 /* Return the innermost context enclosing DECL that is
5221 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
5222 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
5224 tree
5225 decl_type_context (decl)
5226 tree decl;
5228 tree context = DECL_CONTEXT (decl);
5230 while (context)
5232 if (TREE_CODE (context) == RECORD_TYPE
5233 || TREE_CODE (context) == UNION_TYPE
5234 || TREE_CODE (context) == QUAL_UNION_TYPE)
5235 return context;
5237 if (TREE_CODE (context) == TYPE_DECL
5238 || TREE_CODE (context) == FUNCTION_DECL)
5239 context = DECL_CONTEXT (context);
5241 else if (TREE_CODE (context) == BLOCK)
5242 context = BLOCK_SUPERCONTEXT (context);
5244 else
5245 /* Unhandled CONTEXT!? */
5246 abort ();
5248 return NULL_TREE;
5251 /* CALL is a CALL_EXPR. Return the declaration for the function
5252 called, or NULL_TREE if the called function cannot be
5253 determined. */
5255 tree
5256 get_callee_fndecl (call)
5257 tree call;
5259 tree addr;
5261 /* It's invalid to call this function with anything but a
5262 CALL_EXPR. */
5263 if (TREE_CODE (call) != CALL_EXPR)
5264 abort ();
5266 /* The first operand to the CALL is the address of the function
5267 called. */
5268 addr = TREE_OPERAND (call, 0);
5270 STRIP_NOPS (addr);
5272 /* If this is a readonly function pointer, extract its initial value. */
5273 if (DECL_P (addr) && TREE_CODE (addr) != FUNCTION_DECL
5274 && TREE_READONLY (addr) && ! TREE_THIS_VOLATILE (addr)
5275 && DECL_INITIAL (addr))
5276 addr = DECL_INITIAL (addr);
5278 /* If the address is just `&f' for some function `f', then we know
5279 that `f' is being called. */
5280 if (TREE_CODE (addr) == ADDR_EXPR
5281 && TREE_CODE (TREE_OPERAND (addr, 0)) == FUNCTION_DECL)
5282 return TREE_OPERAND (addr, 0);
5284 /* We couldn't figure out what was being called. */
5285 return NULL_TREE;
5288 /* Print debugging information about the obstack O, named STR. */
5290 void
5291 print_obstack_statistics (str, o)
5292 const char *str;
5293 struct obstack *o;
5295 struct _obstack_chunk *chunk = o->chunk;
5296 int n_chunks = 1;
5297 int n_alloc = 0;
5299 n_alloc += o->next_free - chunk->contents;
5300 chunk = chunk->prev;
5301 while (chunk)
5303 n_chunks += 1;
5304 n_alloc += chunk->limit - &chunk->contents[0];
5305 chunk = chunk->prev;
5307 fprintf (stderr, "obstack %s: %u bytes, %d chunks\n",
5308 str, n_alloc, n_chunks);
5311 /* Print debugging information about tree nodes generated during the compile,
5312 and any language-specific information. */
5314 void
5315 dump_tree_statistics ()
5317 #ifdef GATHER_STATISTICS
5318 int i;
5319 int total_nodes, total_bytes;
5320 #endif
5322 fprintf (stderr, "\n??? tree nodes created\n\n");
5323 #ifdef GATHER_STATISTICS
5324 fprintf (stderr, "Kind Nodes Bytes\n");
5325 fprintf (stderr, "-------------------------------------\n");
5326 total_nodes = total_bytes = 0;
5327 for (i = 0; i < (int) all_kinds; i++)
5329 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
5330 tree_node_counts[i], tree_node_sizes[i]);
5331 total_nodes += tree_node_counts[i];
5332 total_bytes += tree_node_sizes[i];
5334 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
5335 fprintf (stderr, "-------------------------------------\n");
5336 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
5337 fprintf (stderr, "-------------------------------------\n");
5338 #else
5339 fprintf (stderr, "(No per-node statistics)\n");
5340 #endif
5341 print_obstack_statistics ("permanent_obstack", &permanent_obstack);
5342 print_obstack_statistics ("maybepermanent_obstack", &maybepermanent_obstack);
5343 print_obstack_statistics ("temporary_obstack", &temporary_obstack);
5344 print_obstack_statistics ("momentary_obstack", &momentary_obstack);
5345 print_obstack_statistics ("temp_decl_obstack", &temp_decl_obstack);
5346 print_type_hash_statistics ();
5347 print_lang_statistics ();
5350 #define FILE_FUNCTION_PREFIX_LEN 9
5352 #ifndef NO_DOLLAR_IN_LABEL
5353 #define FILE_FUNCTION_FORMAT "_GLOBAL_$%s$%s"
5354 #else /* NO_DOLLAR_IN_LABEL */
5355 #ifndef NO_DOT_IN_LABEL
5356 #define FILE_FUNCTION_FORMAT "_GLOBAL_.%s.%s"
5357 #else /* NO_DOT_IN_LABEL */
5358 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
5359 #endif /* NO_DOT_IN_LABEL */
5360 #endif /* NO_DOLLAR_IN_LABEL */
5362 extern char *first_global_object_name;
5363 extern char *weak_global_object_name;
5365 /* Appends 6 random characters to TEMPLATE to (hopefully) avoid name
5366 clashes in cases where we can't reliably choose a unique name.
5368 Derived from mkstemp.c in libiberty. */
5370 static void
5371 append_random_chars (template)
5372 char *template;
5374 static const char letters[]
5375 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
5376 static unsigned HOST_WIDE_INT value;
5377 unsigned HOST_WIDE_INT v;
5379 #ifdef HAVE_GETTIMEOFDAY
5380 struct timeval tv;
5381 #endif
5383 template += strlen (template);
5385 #ifdef HAVE_GETTIMEOFDAY
5386 /* Get some more or less random data. */
5387 gettimeofday (&tv, NULL);
5388 value += ((unsigned HOST_WIDE_INT) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();
5389 #else
5390 value += getpid ();
5391 #endif
5393 v = value;
5395 /* Fill in the random bits. */
5396 template[0] = letters[v % 62];
5397 v /= 62;
5398 template[1] = letters[v % 62];
5399 v /= 62;
5400 template[2] = letters[v % 62];
5401 v /= 62;
5402 template[3] = letters[v % 62];
5403 v /= 62;
5404 template[4] = letters[v % 62];
5405 v /= 62;
5406 template[5] = letters[v % 62];
5408 template[6] = '\0';
5411 /* Generate a name for a function unique to this translation unit.
5412 TYPE is some string to identify the purpose of this function to the
5413 linker or collect2. */
5415 tree
5416 get_file_function_name_long (type)
5417 const char *type;
5419 char *buf;
5420 register char *p;
5422 if (first_global_object_name)
5423 p = first_global_object_name;
5424 else
5426 /* We don't have anything that we know to be unique to this translation
5427 unit, so use what we do have and throw in some randomness. */
5429 const char *name = weak_global_object_name;
5430 const char *file = main_input_filename;
5432 if (! name)
5433 name = "";
5434 if (! file)
5435 file = input_filename;
5437 p = (char *) alloca (7 + strlen (name) + strlen (file));
5439 sprintf (p, "%s%s", name, file);
5440 append_random_chars (p);
5443 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)
5444 + strlen (type));
5446 /* Set up the name of the file-level functions we may need.
5447 Use a global object (which is already required to be unique over
5448 the program) rather than the file name (which imposes extra
5449 constraints). */
5450 sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
5452 /* Don't need to pull weird characters out of global names. */
5453 if (p != first_global_object_name)
5455 for (p = buf+11; *p; p++)
5456 if (! ( ISDIGIT(*p)
5457 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
5458 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
5459 || *p == '.'
5460 #endif
5461 #endif
5462 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
5463 || *p == '$'
5464 #endif
5465 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
5466 || *p == '.'
5467 #endif
5468 || ISUPPER(*p)
5469 || ISLOWER(*p)))
5470 *p = '_';
5473 return get_identifier (buf);
5476 /* If KIND=='I', return a suitable global initializer (constructor) name.
5477 If KIND=='D', return a suitable global clean-up (destructor) name. */
5479 tree
5480 get_file_function_name (kind)
5481 int kind;
5483 char p[2];
5485 p[0] = kind;
5486 p[1] = 0;
5488 return get_file_function_name_long (p);
5491 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
5492 The result is placed in BUFFER (which has length BIT_SIZE),
5493 with one bit in each char ('\000' or '\001').
5495 If the constructor is constant, NULL_TREE is returned.
5496 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
5498 tree
5499 get_set_constructor_bits (init, buffer, bit_size)
5500 tree init;
5501 char *buffer;
5502 int bit_size;
5504 int i;
5505 tree vals;
5506 HOST_WIDE_INT domain_min
5507 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (init))));
5508 tree non_const_bits = NULL_TREE;
5509 for (i = 0; i < bit_size; i++)
5510 buffer[i] = 0;
5512 for (vals = TREE_OPERAND (init, 1);
5513 vals != NULL_TREE; vals = TREE_CHAIN (vals))
5515 if (TREE_CODE (TREE_VALUE (vals)) != INTEGER_CST
5516 || (TREE_PURPOSE (vals) != NULL_TREE
5517 && TREE_CODE (TREE_PURPOSE (vals)) != INTEGER_CST))
5518 non_const_bits
5519 = tree_cons (TREE_PURPOSE (vals), TREE_VALUE (vals), non_const_bits);
5520 else if (TREE_PURPOSE (vals) != NULL_TREE)
5522 /* Set a range of bits to ones. */
5523 HOST_WIDE_INT lo_index
5524 = TREE_INT_CST_LOW (TREE_PURPOSE (vals)) - domain_min;
5525 HOST_WIDE_INT hi_index
5526 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
5528 if (lo_index < 0 || lo_index >= bit_size
5529 || hi_index < 0 || hi_index >= bit_size)
5530 abort ();
5531 for ( ; lo_index <= hi_index; lo_index++)
5532 buffer[lo_index] = 1;
5534 else
5536 /* Set a single bit to one. */
5537 HOST_WIDE_INT index
5538 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
5539 if (index < 0 || index >= bit_size)
5541 error ("invalid initializer for bit string");
5542 return NULL_TREE;
5544 buffer[index] = 1;
5547 return non_const_bits;
5550 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
5551 The result is placed in BUFFER (which is an array of bytes).
5552 If the constructor is constant, NULL_TREE is returned.
5553 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
5555 tree
5556 get_set_constructor_bytes (init, buffer, wd_size)
5557 tree init;
5558 unsigned char *buffer;
5559 int wd_size;
5561 int i;
5562 int set_word_size = BITS_PER_UNIT;
5563 int bit_size = wd_size * set_word_size;
5564 int bit_pos = 0;
5565 unsigned char *bytep = buffer;
5566 char *bit_buffer = (char *) alloca(bit_size);
5567 tree non_const_bits = get_set_constructor_bits (init, bit_buffer, bit_size);
5569 for (i = 0; i < wd_size; i++)
5570 buffer[i] = 0;
5572 for (i = 0; i < bit_size; i++)
5574 if (bit_buffer[i])
5576 if (BYTES_BIG_ENDIAN)
5577 *bytep |= (1 << (set_word_size - 1 - bit_pos));
5578 else
5579 *bytep |= 1 << bit_pos;
5581 bit_pos++;
5582 if (bit_pos >= set_word_size)
5583 bit_pos = 0, bytep++;
5585 return non_const_bits;
5588 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
5589 /* Complain that the tree code of NODE does not match the expected CODE.
5590 FILE, LINE, and FUNCTION are of the caller. */
5591 void
5592 tree_check_failed (node, code, file, line, function)
5593 const tree node;
5594 enum tree_code code;
5595 const char *file;
5596 int line;
5597 const char *function;
5599 error ("Tree check: expected %s, have %s",
5600 tree_code_name[code], tree_code_name[TREE_CODE (node)]);
5601 fancy_abort (file, line, function);
5604 /* Similar to above, except that we check for a class of tree
5605 code, given in CL. */
5606 void
5607 tree_class_check_failed (node, cl, file, line, function)
5608 const tree node;
5609 char cl;
5610 const char *file;
5611 int line;
5612 const char *function;
5614 error ("Tree check: expected class '%c', have '%c' (%s)",
5615 cl, TREE_CODE_CLASS (TREE_CODE (node)),
5616 tree_code_name[TREE_CODE (node)]);
5617 fancy_abort (file, line, function);
5620 #endif /* ENABLE_TREE_CHECKING */
5622 /* Return the alias set for T, which may be either a type or an
5623 expression. */
5626 get_alias_set (t)
5627 tree t;
5629 if (! flag_strict_aliasing || lang_get_alias_set == 0)
5630 /* If we're not doing any lanaguage-specific alias analysis, just
5631 assume everything aliases everything else. */
5632 return 0;
5633 else
5634 return (*lang_get_alias_set) (t);
5637 /* Return a brand-new alias set. */
5640 new_alias_set ()
5642 static int last_alias_set;
5644 if (flag_strict_aliasing)
5645 return ++last_alias_set;
5646 else
5647 return 0;
5650 #ifndef CHAR_TYPE_SIZE
5651 #define CHAR_TYPE_SIZE BITS_PER_UNIT
5652 #endif
5654 #ifndef SHORT_TYPE_SIZE
5655 #define SHORT_TYPE_SIZE (BITS_PER_UNIT * MIN ((UNITS_PER_WORD + 1) / 2, 2))
5656 #endif
5658 #ifndef INT_TYPE_SIZE
5659 #define INT_TYPE_SIZE BITS_PER_WORD
5660 #endif
5662 #ifndef LONG_TYPE_SIZE
5663 #define LONG_TYPE_SIZE BITS_PER_WORD
5664 #endif
5666 #ifndef LONG_LONG_TYPE_SIZE
5667 #define LONG_LONG_TYPE_SIZE (BITS_PER_WORD * 2)
5668 #endif
5670 #ifndef FLOAT_TYPE_SIZE
5671 #define FLOAT_TYPE_SIZE BITS_PER_WORD
5672 #endif
5674 #ifndef DOUBLE_TYPE_SIZE
5675 #define DOUBLE_TYPE_SIZE (BITS_PER_WORD * 2)
5676 #endif
5678 #ifndef LONG_DOUBLE_TYPE_SIZE
5679 #define LONG_DOUBLE_TYPE_SIZE (BITS_PER_WORD * 2)
5680 #endif
5682 /* Create nodes for all integer types (and error_mark_node) using the sizes
5683 of C datatypes. The caller should call set_sizetype soon after calling
5684 this function to select one of the types as sizetype. */
5686 void
5687 build_common_tree_nodes (signed_char)
5688 int signed_char;
5690 error_mark_node = make_node (ERROR_MARK);
5691 TREE_TYPE (error_mark_node) = error_mark_node;
5693 initialize_sizetypes ();
5695 /* Define both `signed char' and `unsigned char'. */
5696 signed_char_type_node = make_signed_type (CHAR_TYPE_SIZE);
5697 unsigned_char_type_node = make_unsigned_type (CHAR_TYPE_SIZE);
5699 /* Define `char', which is like either `signed char' or `unsigned char'
5700 but not the same as either. */
5701 char_type_node
5702 = (signed_char
5703 ? make_signed_type (CHAR_TYPE_SIZE)
5704 : make_unsigned_type (CHAR_TYPE_SIZE));
5706 short_integer_type_node = make_signed_type (SHORT_TYPE_SIZE);
5707 short_unsigned_type_node = make_unsigned_type (SHORT_TYPE_SIZE);
5708 integer_type_node = make_signed_type (INT_TYPE_SIZE);
5709 unsigned_type_node = make_unsigned_type (INT_TYPE_SIZE);
5710 long_integer_type_node = make_signed_type (LONG_TYPE_SIZE);
5711 long_unsigned_type_node = make_unsigned_type (LONG_TYPE_SIZE);
5712 long_long_integer_type_node = make_signed_type (LONG_LONG_TYPE_SIZE);
5713 long_long_unsigned_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
5715 intQI_type_node = make_signed_type (GET_MODE_BITSIZE (QImode));
5716 intHI_type_node = make_signed_type (GET_MODE_BITSIZE (HImode));
5717 intSI_type_node = make_signed_type (GET_MODE_BITSIZE (SImode));
5718 intDI_type_node = make_signed_type (GET_MODE_BITSIZE (DImode));
5719 intTI_type_node = make_signed_type (GET_MODE_BITSIZE (TImode));
5721 unsigned_intQI_type_node = make_unsigned_type (GET_MODE_BITSIZE (QImode));
5722 unsigned_intHI_type_node = make_unsigned_type (GET_MODE_BITSIZE (HImode));
5723 unsigned_intSI_type_node = make_unsigned_type (GET_MODE_BITSIZE (SImode));
5724 unsigned_intDI_type_node = make_unsigned_type (GET_MODE_BITSIZE (DImode));
5725 unsigned_intTI_type_node = make_unsigned_type (GET_MODE_BITSIZE (TImode));
5728 /* Call this function after calling build_common_tree_nodes and set_sizetype.
5729 It will create several other common tree nodes. */
5731 void
5732 build_common_tree_nodes_2 (short_double)
5733 int short_double;
5735 /* Define these next since types below may used them. */
5736 integer_zero_node = build_int_2 (0, 0);
5737 integer_one_node = build_int_2 (1, 0);
5739 size_zero_node = size_int (0);
5740 size_one_node = size_int (1);
5741 bitsize_zero_node = bitsize_int (0);
5742 bitsize_one_node = bitsize_int (1);
5743 bitsize_unit_node = bitsize_int (BITS_PER_UNIT);
5745 void_type_node = make_node (VOID_TYPE);
5746 layout_type (void_type_node);
5748 /* We are not going to have real types in C with less than byte alignment,
5749 so we might as well not have any types that claim to have it. */
5750 TYPE_ALIGN (void_type_node) = BITS_PER_UNIT;
5752 null_pointer_node = build_int_2 (0, 0);
5753 TREE_TYPE (null_pointer_node) = build_pointer_type (void_type_node);
5754 layout_type (TREE_TYPE (null_pointer_node));
5756 ptr_type_node = build_pointer_type (void_type_node);
5757 const_ptr_type_node
5758 = build_pointer_type (build_type_variant (void_type_node, 1, 0));
5760 float_type_node = make_node (REAL_TYPE);
5761 TYPE_PRECISION (float_type_node) = FLOAT_TYPE_SIZE;
5762 layout_type (float_type_node);
5764 double_type_node = make_node (REAL_TYPE);
5765 if (short_double)
5766 TYPE_PRECISION (double_type_node) = FLOAT_TYPE_SIZE;
5767 else
5768 TYPE_PRECISION (double_type_node) = DOUBLE_TYPE_SIZE;
5769 layout_type (double_type_node);
5771 long_double_type_node = make_node (REAL_TYPE);
5772 TYPE_PRECISION (long_double_type_node) = LONG_DOUBLE_TYPE_SIZE;
5773 layout_type (long_double_type_node);
5775 complex_integer_type_node = make_node (COMPLEX_TYPE);
5776 TREE_TYPE (complex_integer_type_node) = integer_type_node;
5777 layout_type (complex_integer_type_node);
5779 complex_float_type_node = make_node (COMPLEX_TYPE);
5780 TREE_TYPE (complex_float_type_node) = float_type_node;
5781 layout_type (complex_float_type_node);
5783 complex_double_type_node = make_node (COMPLEX_TYPE);
5784 TREE_TYPE (complex_double_type_node) = double_type_node;
5785 layout_type (complex_double_type_node);
5787 complex_long_double_type_node = make_node (COMPLEX_TYPE);
5788 TREE_TYPE (complex_long_double_type_node) = long_double_type_node;
5789 layout_type (complex_long_double_type_node);
5791 #ifdef BUILD_VA_LIST_TYPE
5792 BUILD_VA_LIST_TYPE(va_list_type_node);
5793 #else
5794 va_list_type_node = ptr_type_node;
5795 #endif