1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 1988, 1992, 1993, 1994 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file contains the low level primitives for operating on tree nodes,
22 including allocation, list operations, interning of identifiers,
23 construction of data type nodes and statement nodes,
24 and construction of type conversion nodes. It also contains
25 tables index by tree code that describe how to take apart
28 It is intended to be language-independent, but occasionally
29 calls language-dependent routines defined (for C) in typecheck.c.
31 The low-level allocation routines oballoc and permalloc
32 are used also for allocating many other kinds of objects
33 by all passes of the compiler. */
47 #define obstack_chunk_alloc xmalloc
48 #define obstack_chunk_free free
50 /* Tree nodes of permanent duration are allocated in this obstack.
51 They are the identifier nodes, and everything outside of
52 the bodies and parameters of function definitions. */
54 struct obstack permanent_obstack;
56 /* The initial RTL, and all ..._TYPE nodes, in a function
57 are allocated in this obstack. Usually they are freed at the
58 end of the function, but if the function is inline they are saved.
59 For top-level functions, this is maybepermanent_obstack.
60 Separate obstacks are made for nested functions. */
62 struct obstack *function_maybepermanent_obstack;
64 /* This is the function_maybepermanent_obstack for top-level functions. */
66 struct obstack maybepermanent_obstack;
68 /* The contents of the current function definition are allocated
69 in this obstack, and all are freed at the end of the function.
70 For top-level functions, this is temporary_obstack.
71 Separate obstacks are made for nested functions. */
73 struct obstack *function_obstack;
75 /* This is used for reading initializers of global variables. */
77 struct obstack temporary_obstack;
79 /* The tree nodes of an expression are allocated
80 in this obstack, and all are freed at the end of the expression. */
82 struct obstack momentary_obstack;
84 /* The tree nodes of a declarator are allocated
85 in this obstack, and all are freed when the declarator
88 static struct obstack temp_decl_obstack;
90 /* This points at either permanent_obstack
91 or the current function_maybepermanent_obstack. */
93 struct obstack *saveable_obstack;
95 /* This is same as saveable_obstack during parse and expansion phase;
96 it points to the current function's obstack during optimization.
97 This is the obstack to be used for creating rtl objects. */
99 struct obstack *rtl_obstack;
101 /* This points at either permanent_obstack or the current function_obstack. */
103 struct obstack *current_obstack;
105 /* This points at either permanent_obstack or the current function_obstack
106 or momentary_obstack. */
108 struct obstack *expression_obstack;
110 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
114 struct obstack_stack *next;
115 struct obstack *current;
116 struct obstack *saveable;
117 struct obstack *expression;
121 struct obstack_stack *obstack_stack;
123 /* Obstack for allocating struct obstack_stack entries. */
125 static struct obstack obstack_stack_obstack;
127 /* Addresses of first objects in some obstacks.
128 This is for freeing their entire contents. */
129 char *maybepermanent_firstobj;
130 char *temporary_firstobj;
131 char *momentary_firstobj;
132 char *temp_decl_firstobj;
134 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
136 int all_types_permanent;
138 /* Stack of places to restore the momentary obstack back to. */
140 struct momentary_level
142 /* Pointer back to previous such level. */
143 struct momentary_level *prev;
144 /* First object allocated within this level. */
146 /* Value of expression_obstack saved at entry to this level. */
147 struct obstack *obstack;
150 struct momentary_level *momentary_stack;
152 /* Table indexed by tree code giving a string containing a character
153 classifying the tree code. Possibilities are
154 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
156 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
158 char *standard_tree_code_type[] = {
163 /* Table indexed by tree code giving number of expression
164 operands beyond the fixed part of the node structure.
165 Not used for types or decls. */
167 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
169 int standard_tree_code_length[] = {
174 /* Names of tree components.
175 Used for printing out the tree and error messages. */
176 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
178 char *standard_tree_code_name[] = {
183 /* Table indexed by tree code giving a string containing a character
184 classifying the tree code. Possibilities are
185 t, d, s, c, r, e, <, 1 and 2. See tree.def for details. */
187 char **tree_code_type;
189 /* Table indexed by tree code giving number of expression
190 operands beyond the fixed part of the node structure.
191 Not used for types or decls. */
193 int *tree_code_length;
195 /* Table indexed by tree code giving name of tree code, as a string. */
197 char **tree_code_name;
199 /* Statistics-gathering stuff. */
220 int tree_node_counts[(int)all_kinds];
221 int tree_node_sizes[(int)all_kinds];
222 int id_string_size = 0;
224 char *tree_node_kind_names[] = {
242 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
244 #define MAX_HASH_TABLE 1009
245 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
247 /* 0 while creating built-in identifiers. */
248 static int do_identifier_warnings;
250 /* Unique id for next decl created. */
251 static int next_decl_uid;
252 /* Unique id for next type created. */
253 static int next_type_uid = 1;
255 extern char *mode_name[];
257 void gcc_obstack_init ();
258 static tree stabilize_reference_1 ();
260 /* Init the principal obstacks. */
265 gcc_obstack_init (&obstack_stack_obstack);
266 gcc_obstack_init (&permanent_obstack);
268 gcc_obstack_init (&temporary_obstack);
269 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
270 gcc_obstack_init (&momentary_obstack);
271 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
272 gcc_obstack_init (&maybepermanent_obstack);
273 maybepermanent_firstobj
274 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
275 gcc_obstack_init (&temp_decl_obstack);
276 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
278 function_obstack = &temporary_obstack;
279 function_maybepermanent_obstack = &maybepermanent_obstack;
280 current_obstack = &permanent_obstack;
281 expression_obstack = &permanent_obstack;
282 rtl_obstack = saveable_obstack = &permanent_obstack;
284 /* Init the hash table of identifiers. */
285 bzero (hash_table, sizeof hash_table);
289 gcc_obstack_init (obstack)
290 struct obstack *obstack;
292 /* Let particular systems override the size of a chunk. */
293 #ifndef OBSTACK_CHUNK_SIZE
294 #define OBSTACK_CHUNK_SIZE 0
296 /* Let them override the alloc and free routines too. */
297 #ifndef OBSTACK_CHUNK_ALLOC
298 #define OBSTACK_CHUNK_ALLOC xmalloc
300 #ifndef OBSTACK_CHUNK_FREE
301 #define OBSTACK_CHUNK_FREE free
303 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
304 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
305 (void (*) ()) OBSTACK_CHUNK_FREE);
308 /* Save all variables describing the current status into the structure *P.
309 This is used before starting a nested function. */
315 p->all_types_permanent = all_types_permanent;
316 p->momentary_stack = momentary_stack;
317 p->maybepermanent_firstobj = maybepermanent_firstobj;
318 p->momentary_firstobj = momentary_firstobj;
319 p->function_obstack = function_obstack;
320 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
321 p->current_obstack = current_obstack;
322 p->expression_obstack = expression_obstack;
323 p->saveable_obstack = saveable_obstack;
324 p->rtl_obstack = rtl_obstack;
326 /* Objects that need to be saved in this function can be in the nonsaved
327 obstack of the enclosing function since they can't possibly be needed
328 once it has returned. */
329 function_maybepermanent_obstack = function_obstack;
331 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
332 gcc_obstack_init (function_obstack);
334 current_obstack = &permanent_obstack;
335 expression_obstack = &permanent_obstack;
336 rtl_obstack = saveable_obstack = &permanent_obstack;
338 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
339 maybepermanent_firstobj
340 = (char *) obstack_finish (function_maybepermanent_obstack);
343 /* Restore all variables describing the current status from the structure *P.
344 This is used after a nested function. */
347 restore_tree_status (p)
350 all_types_permanent = p->all_types_permanent;
351 momentary_stack = p->momentary_stack;
353 obstack_free (&momentary_obstack, momentary_firstobj);
355 /* Free saveable storage used by the function just compiled and not
358 CAUTION: This is in function_obstack of the containing function. So
359 we must be sure that we never allocate from that obstack during
360 the compilation of a nested function if we expect it to survive past the
361 nested function's end. */
362 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
364 obstack_free (function_obstack, 0);
365 free (function_obstack);
367 momentary_firstobj = p->momentary_firstobj;
368 maybepermanent_firstobj = p->maybepermanent_firstobj;
369 function_obstack = p->function_obstack;
370 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
371 current_obstack = p->current_obstack;
372 expression_obstack = p->expression_obstack;
373 saveable_obstack = p->saveable_obstack;
374 rtl_obstack = p->rtl_obstack;
377 /* Start allocating on the temporary (per function) obstack.
378 This is done in start_function before parsing the function body,
379 and before each initialization at top level, and to go back
380 to temporary allocation after doing permanent_allocation. */
383 temporary_allocation ()
385 /* Note that function_obstack at top level points to temporary_obstack.
386 But within a nested function context, it is a separate obstack. */
387 current_obstack = function_obstack;
388 expression_obstack = function_obstack;
389 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
393 /* Start allocating on the permanent obstack but don't
394 free the temporary data. After calling this, call
395 `permanent_allocation' to fully resume permanent allocation status. */
398 end_temporary_allocation ()
400 current_obstack = &permanent_obstack;
401 expression_obstack = &permanent_obstack;
402 rtl_obstack = saveable_obstack = &permanent_obstack;
405 /* Resume allocating on the temporary obstack, undoing
406 effects of `end_temporary_allocation'. */
409 resume_temporary_allocation ()
411 current_obstack = function_obstack;
412 expression_obstack = function_obstack;
413 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
416 /* While doing temporary allocation, switch to allocating in such a
417 way as to save all nodes if the function is inlined. Call
418 resume_temporary_allocation to go back to ordinary temporary
422 saveable_allocation ()
424 /* Note that function_obstack at top level points to temporary_obstack.
425 But within a nested function context, it is a separate obstack. */
426 expression_obstack = current_obstack = saveable_obstack;
429 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
430 recording the previously current obstacks on a stack.
431 This does not free any storage in any obstack. */
434 push_obstacks (current, saveable)
435 struct obstack *current, *saveable;
437 struct obstack_stack *p
438 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
439 (sizeof (struct obstack_stack)));
441 p->current = current_obstack;
442 p->saveable = saveable_obstack;
443 p->expression = expression_obstack;
444 p->rtl = rtl_obstack;
445 p->next = obstack_stack;
448 current_obstack = current;
449 expression_obstack = current;
450 rtl_obstack = saveable_obstack = saveable;
453 /* Save the current set of obstacks, but don't change them. */
456 push_obstacks_nochange ()
458 struct obstack_stack *p
459 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
460 (sizeof (struct obstack_stack)));
462 p->current = current_obstack;
463 p->saveable = saveable_obstack;
464 p->expression = expression_obstack;
465 p->rtl = rtl_obstack;
466 p->next = obstack_stack;
470 /* Pop the obstack selection stack. */
475 struct obstack_stack *p = obstack_stack;
476 obstack_stack = p->next;
478 current_obstack = p->current;
479 saveable_obstack = p->saveable;
480 expression_obstack = p->expression;
481 rtl_obstack = p->rtl;
483 obstack_free (&obstack_stack_obstack, p);
486 /* Nonzero if temporary allocation is currently in effect.
487 Zero if currently doing permanent allocation. */
490 allocation_temporary_p ()
492 return current_obstack != &permanent_obstack;
495 /* Go back to allocating on the permanent obstack
496 and free everything in the temporary obstack.
497 This is done in finish_function after fully compiling a function. */
500 permanent_allocation ()
502 /* Free up previous temporary obstack data */
503 obstack_free (&temporary_obstack, temporary_firstobj);
504 obstack_free (&momentary_obstack, momentary_firstobj);
505 obstack_free (&maybepermanent_obstack, maybepermanent_firstobj);
506 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
508 current_obstack = &permanent_obstack;
509 expression_obstack = &permanent_obstack;
510 rtl_obstack = saveable_obstack = &permanent_obstack;
513 /* Save permanently everything on the maybepermanent_obstack. */
518 maybepermanent_firstobj
519 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
523 preserve_initializer ()
526 = (char *) obstack_alloc (&temporary_obstack, 0);
528 = (char *) obstack_alloc (&momentary_obstack, 0);
529 maybepermanent_firstobj
530 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
533 /* Start allocating new rtl in current_obstack.
534 Use resume_temporary_allocation
535 to go back to allocating rtl in saveable_obstack. */
538 rtl_in_current_obstack ()
540 rtl_obstack = current_obstack;
543 /* Start allocating rtl from saveable_obstack. Intended to be used after
544 a call to push_obstacks_nochange. */
547 rtl_in_saveable_obstack ()
549 rtl_obstack = saveable_obstack;
552 /* Allocate SIZE bytes in the current obstack
553 and return a pointer to them.
554 In practice the current obstack is always the temporary one. */
560 return (char *) obstack_alloc (current_obstack, size);
563 /* Free the object PTR in the current obstack
564 as well as everything allocated since PTR.
565 In practice the current obstack is always the temporary one. */
571 obstack_free (current_obstack, ptr);
574 /* Allocate SIZE bytes in the permanent obstack
575 and return a pointer to them. */
581 return (char *) obstack_alloc (&permanent_obstack, size);
584 /* Allocate NELEM items of SIZE bytes in the permanent obstack
585 and return a pointer to them. The storage is cleared before
586 returning the value. */
589 perm_calloc (nelem, size)
593 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
594 bzero (rval, nelem * size);
598 /* Allocate SIZE bytes in the saveable obstack
599 and return a pointer to them. */
605 return (char *) obstack_alloc (saveable_obstack, size);
608 /* Print out which obstack an object is in. */
611 print_obstack_name (object, file, prefix)
616 struct obstack *obstack = NULL;
617 char *obstack_name = NULL;
620 for (p = outer_function_chain; p; p = p->next)
622 if (_obstack_allocated_p (p->function_obstack, object))
624 obstack = p->function_obstack;
625 obstack_name = "containing function obstack";
627 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
629 obstack = p->function_maybepermanent_obstack;
630 obstack_name = "containing function maybepermanent obstack";
634 if (_obstack_allocated_p (&obstack_stack_obstack, object))
636 obstack = &obstack_stack_obstack;
637 obstack_name = "obstack_stack_obstack";
639 else if (_obstack_allocated_p (function_obstack, object))
641 obstack = function_obstack;
642 obstack_name = "function obstack";
644 else if (_obstack_allocated_p (&permanent_obstack, object))
646 obstack = &permanent_obstack;
647 obstack_name = "permanent_obstack";
649 else if (_obstack_allocated_p (&momentary_obstack, object))
651 obstack = &momentary_obstack;
652 obstack_name = "momentary_obstack";
654 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
656 obstack = function_maybepermanent_obstack;
657 obstack_name = "function maybepermanent obstack";
659 else if (_obstack_allocated_p (&temp_decl_obstack, object))
661 obstack = &temp_decl_obstack;
662 obstack_name = "temp_decl_obstack";
665 /* Check to see if the object is in the free area of the obstack. */
668 if (object >= obstack->next_free
669 && object < obstack->chunk_limit)
670 fprintf (file, "%s in free portion of obstack %s",
671 prefix, obstack_name);
673 fprintf (file, "%s allocated from %s", prefix, obstack_name);
676 fprintf (file, "%s not allocated from any obstack", prefix);
680 debug_obstack (object)
683 print_obstack_name (object, stderr, "object");
684 fprintf (stderr, ".\n");
687 /* Return 1 if OBJ is in the permanent obstack.
688 This is slow, and should be used only for debugging.
689 Use TREE_PERMANENT for other purposes. */
692 object_permanent_p (obj)
695 return _obstack_allocated_p (&permanent_obstack, obj);
698 /* Start a level of momentary allocation.
699 In C, each compound statement has its own level
700 and that level is freed at the end of each statement.
701 All expression nodes are allocated in the momentary allocation level. */
706 struct momentary_level *tem
707 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
708 sizeof (struct momentary_level));
709 tem->prev = momentary_stack;
710 tem->base = (char *) obstack_base (&momentary_obstack);
711 tem->obstack = expression_obstack;
712 momentary_stack = tem;
713 expression_obstack = &momentary_obstack;
716 /* Free all the storage in the current momentary-allocation level.
717 In C, this happens at the end of each statement. */
722 obstack_free (&momentary_obstack, momentary_stack->base);
725 /* Discard a level of momentary allocation.
726 In C, this happens at the end of each compound statement.
727 Restore the status of expression node allocation
728 that was in effect before this level was created. */
733 struct momentary_level *tem = momentary_stack;
734 momentary_stack = tem->prev;
735 expression_obstack = tem->obstack;
736 obstack_free (&momentary_obstack, tem);
739 /* Pop back to the previous level of momentary allocation,
740 but don't free any momentary data just yet. */
743 pop_momentary_nofree ()
745 struct momentary_level *tem = momentary_stack;
746 momentary_stack = tem->prev;
747 expression_obstack = tem->obstack;
750 /* Call when starting to parse a declaration:
751 make expressions in the declaration last the length of the function.
752 Returns an argument that should be passed to resume_momentary later. */
757 register int tem = expression_obstack == &momentary_obstack;
758 expression_obstack = saveable_obstack;
762 /* Call when finished parsing a declaration:
763 restore the treatment of node-allocation that was
764 in effect before the suspension.
765 YES should be the value previously returned by suspend_momentary. */
768 resume_momentary (yes)
772 expression_obstack = &momentary_obstack;
775 /* Init the tables indexed by tree code.
776 Note that languages can add to these tables to define their own codes. */
781 tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type));
782 tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length));
783 tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name));
784 bcopy (standard_tree_code_type, tree_code_type,
785 sizeof (standard_tree_code_type));
786 bcopy (standard_tree_code_length, tree_code_length,
787 sizeof (standard_tree_code_length));
788 bcopy (standard_tree_code_name, tree_code_name,
789 sizeof (standard_tree_code_name));
792 /* Return a newly allocated node of code CODE.
793 Initialize the node's unique id and its TREE_PERMANENT flag.
794 For decl and type nodes, some other fields are initialized.
795 The rest of the node is initialized to zero.
797 Achoo! I got a code in the node. */
804 register int type = TREE_CODE_CLASS (code);
806 register struct obstack *obstack = current_obstack;
808 register tree_node_kind kind;
812 case 'd': /* A decl node */
813 #ifdef GATHER_STATISTICS
816 length = sizeof (struct tree_decl);
817 /* All decls in an inline function need to be saved. */
818 if (obstack != &permanent_obstack)
819 obstack = saveable_obstack;
821 /* PARM_DECLs go on the context of the parent. If this is a nested
822 function, then we must allocate the PARM_DECL on the parent's
823 obstack, so that they will live to the end of the parent's
824 closing brace. This is neccesary in case we try to inline the
825 function into its parent.
827 PARM_DECLs of top-level functions do not have this problem. However,
828 we allocate them where we put the FUNCTION_DECL for languauges such as
829 Ada that need to consult some flags in the PARM_DECLs of the function
832 See comment in restore_tree_status for why we can't put this
833 in function_obstack. */
834 if (code == PARM_DECL && obstack != &permanent_obstack)
837 if (current_function_decl)
838 context = decl_function_context (current_function_decl);
842 = find_function_data (context)->function_maybepermanent_obstack;
846 case 't': /* a type node */
847 #ifdef GATHER_STATISTICS
850 length = sizeof (struct tree_type);
851 /* All data types are put where we can preserve them if nec. */
852 if (obstack != &permanent_obstack)
853 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
856 case 'b': /* a lexical block */
857 #ifdef GATHER_STATISTICS
860 length = sizeof (struct tree_block);
861 /* All BLOCK nodes are put where we can preserve them if nec. */
862 if (obstack != &permanent_obstack)
863 obstack = saveable_obstack;
866 case 's': /* an expression with side effects */
867 #ifdef GATHER_STATISTICS
871 case 'r': /* a reference */
872 #ifdef GATHER_STATISTICS
876 case 'e': /* an expression */
877 case '<': /* a comparison expression */
878 case '1': /* a unary arithmetic expression */
879 case '2': /* a binary arithmetic expression */
880 #ifdef GATHER_STATISTICS
884 obstack = expression_obstack;
885 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
886 if (code == BIND_EXPR && obstack != &permanent_obstack)
887 obstack = saveable_obstack;
888 length = sizeof (struct tree_exp)
889 + (tree_code_length[(int) code] - 1) * sizeof (char *);
892 case 'c': /* a constant */
893 #ifdef GATHER_STATISTICS
896 obstack = expression_obstack;
898 /* We can't use tree_code_length for INTEGER_CST, since the number of
899 words is machine-dependent due to varying length of HOST_WIDE_INT,
900 which might be wider than a pointer (e.g., long long). Similarly
901 for REAL_CST, since the number of words is machine-dependent due
902 to varying size and alignment of `double'. */
904 if (code == INTEGER_CST)
905 length = sizeof (struct tree_int_cst);
906 else if (code == REAL_CST)
907 length = sizeof (struct tree_real_cst);
909 length = sizeof (struct tree_common)
910 + tree_code_length[(int) code] * sizeof (char *);
913 case 'x': /* something random, like an identifier. */
914 #ifdef GATHER_STATISTICS
915 if (code == IDENTIFIER_NODE)
917 else if (code == OP_IDENTIFIER)
919 else if (code == TREE_VEC)
924 length = sizeof (struct tree_common)
925 + tree_code_length[(int) code] * sizeof (char *);
926 /* Identifier nodes are always permanent since they are
927 unique in a compiler run. */
928 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
931 t = (tree) obstack_alloc (obstack, length);
933 #ifdef GATHER_STATISTICS
934 tree_node_counts[(int)kind]++;
935 tree_node_sizes[(int)kind] += length;
938 /* Clear a word at a time. */
939 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
941 /* Clear any extra bytes. */
942 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
945 TREE_SET_CODE (t, code);
946 if (obstack == &permanent_obstack)
947 TREE_PERMANENT (t) = 1;
952 TREE_SIDE_EFFECTS (t) = 1;
953 TREE_TYPE (t) = void_type_node;
957 if (code != FUNCTION_DECL)
959 DECL_IN_SYSTEM_HEADER (t)
960 = in_system_header && (obstack == &permanent_obstack);
961 DECL_SOURCE_LINE (t) = lineno;
962 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
963 DECL_UID (t) = next_decl_uid++;
967 TYPE_UID (t) = next_type_uid++;
969 TYPE_MAIN_VARIANT (t) = t;
970 TYPE_OBSTACK (t) = obstack;
974 TREE_CONSTANT (t) = 1;
981 /* Return a new node with the same contents as NODE
982 except that its TREE_CHAIN is zero and it has a fresh uid. */
989 register enum tree_code code = TREE_CODE (node);
993 switch (TREE_CODE_CLASS (code))
995 case 'd': /* A decl node */
996 length = sizeof (struct tree_decl);
999 case 't': /* a type node */
1000 length = sizeof (struct tree_type);
1003 case 'b': /* a lexical block node */
1004 length = sizeof (struct tree_block);
1007 case 'r': /* a reference */
1008 case 'e': /* an expression */
1009 case 's': /* an expression with side effects */
1010 case '<': /* a comparison expression */
1011 case '1': /* a unary arithmetic expression */
1012 case '2': /* a binary arithmetic expression */
1013 length = sizeof (struct tree_exp)
1014 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1017 case 'c': /* a constant */
1018 /* We can't use tree_code_length for INTEGER_CST, since the number of
1019 words is machine-dependent due to varying length of HOST_WIDE_INT,
1020 which might be wider than a pointer (e.g., long long). Similarly
1021 for REAL_CST, since the number of words is machine-dependent due
1022 to varying size and alignment of `double'. */
1023 if (code == INTEGER_CST)
1025 length = sizeof (struct tree_int_cst);
1028 else if (code == REAL_CST)
1030 length = sizeof (struct tree_real_cst);
1034 case 'x': /* something random, like an identifier. */
1035 length = sizeof (struct tree_common)
1036 + tree_code_length[(int) code] * sizeof (char *);
1037 if (code == TREE_VEC)
1038 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1041 t = (tree) obstack_alloc (current_obstack, length);
1043 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1044 ((int *) t)[i] = ((int *) node)[i];
1045 /* Clear any extra bytes. */
1046 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1047 ((char *) t)[i] = ((char *) node)[i];
1051 if (TREE_CODE_CLASS (code) == 'd')
1052 DECL_UID (t) = next_decl_uid++;
1053 else if (TREE_CODE_CLASS (code) == 't')
1055 TYPE_UID (t) = next_type_uid++;
1056 TYPE_OBSTACK (t) = current_obstack;
1059 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1064 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1065 For example, this can copy a list made of TREE_LIST nodes. */
1072 register tree prev, next;
1077 head = prev = copy_node (list);
1078 next = TREE_CHAIN (list);
1081 TREE_CHAIN (prev) = copy_node (next);
1082 prev = TREE_CHAIN (prev);
1083 next = TREE_CHAIN (next);
1090 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1091 If an identifier with that name has previously been referred to,
1092 the same node is returned this time. */
1095 get_identifier (text)
1096 register char *text;
1101 register int len, hash_len;
1103 /* Compute length of text in len. */
1104 for (len = 0; text[len]; len++);
1106 /* Decide how much of that length to hash on */
1108 if (warn_id_clash && len > id_clash_len)
1109 hash_len = id_clash_len;
1111 /* Compute hash code */
1112 hi = hash_len * 613 + (unsigned)text[0];
1113 for (i = 1; i < hash_len; i += 2)
1114 hi = ((hi * 613) + (unsigned)(text[i]));
1116 hi &= (1 << HASHBITS) - 1;
1117 hi %= MAX_HASH_TABLE;
1119 /* Search table for identifier */
1120 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1121 if (IDENTIFIER_LENGTH (idp) == len
1122 && IDENTIFIER_POINTER (idp)[0] == text[0]
1123 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1124 return idp; /* <-- return if found */
1126 /* Not found; optionally warn about a similar identifier */
1127 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1128 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1129 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1131 warning ("`%s' and `%s' identical in first %d characters",
1132 IDENTIFIER_POINTER (idp), text, id_clash_len);
1136 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1137 abort (); /* set_identifier_size hasn't been called. */
1139 /* Not found, create one, add to chain */
1140 idp = make_node (IDENTIFIER_NODE);
1141 IDENTIFIER_LENGTH (idp) = len;
1142 #ifdef GATHER_STATISTICS
1143 id_string_size += len;
1146 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1148 TREE_CHAIN (idp) = hash_table[hi];
1149 hash_table[hi] = idp;
1150 return idp; /* <-- return if created */
1153 /* Enable warnings on similar identifiers (if requested).
1154 Done after the built-in identifiers are created. */
1157 start_identifier_warnings ()
1159 do_identifier_warnings = 1;
1162 /* Record the size of an identifier node for the language in use.
1163 SIZE is the total size in bytes.
1164 This is called by the language-specific files. This must be
1165 called before allocating any identifiers. */
1168 set_identifier_size (size)
1171 tree_code_length[(int) IDENTIFIER_NODE]
1172 = (size - sizeof (struct tree_common)) / sizeof (tree);
1175 /* Return a newly constructed INTEGER_CST node whose constant value
1176 is specified by the two ints LOW and HI.
1177 The TREE_TYPE is set to `int'.
1179 This function should be used via the `build_int_2' macro. */
1182 build_int_2_wide (low, hi)
1183 HOST_WIDE_INT low, hi;
1185 register tree t = make_node (INTEGER_CST);
1186 TREE_INT_CST_LOW (t) = low;
1187 TREE_INT_CST_HIGH (t) = hi;
1188 TREE_TYPE (t) = integer_type_node;
1192 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1195 build_real (type, d)
1201 /* Check for valid float value for this type on this target machine;
1202 if not, can print error message and store a valid value in D. */
1203 #ifdef CHECK_FLOAT_VALUE
1204 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1207 v = make_node (REAL_CST);
1208 TREE_TYPE (v) = type;
1209 TREE_REAL_CST (v) = d;
1213 /* Return a new REAL_CST node whose type is TYPE
1214 and whose value is the integer value of the INTEGER_CST node I. */
1216 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1219 real_value_from_int_cst (i)
1224 /* Some 386 compilers mishandle unsigned int to float conversions,
1225 so introduce a temporary variable E to avoid those bugs. */
1227 #ifdef REAL_ARITHMETIC
1228 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1229 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1231 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1232 #else /* not REAL_ARITHMETIC */
1233 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1235 d = (double) (~ TREE_INT_CST_HIGH (i));
1236 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1237 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1239 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1245 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1246 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1247 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1249 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1252 #endif /* not REAL_ARITHMETIC */
1256 /* This function can't be implemented if we can't do arithmetic
1257 on the float representation. */
1260 build_real_from_int_cst (type, i)
1267 v = make_node (REAL_CST);
1268 TREE_TYPE (v) = type;
1270 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type), real_value_from_int_cst (i));
1271 /* Check for valid float value for this type on this target machine;
1272 if not, can print error message and store a valid value in D. */
1273 #ifdef CHECK_FLOAT_VALUE
1274 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1277 TREE_REAL_CST (v) = d;
1281 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1283 /* Return a newly constructed STRING_CST node whose value is
1284 the LEN characters at STR.
1285 The TREE_TYPE is not initialized. */
1288 build_string (len, str)
1292 /* Put the string in saveable_obstack since it will be placed in the RTL
1293 for an "asm" statement and will also be kept around a while if
1294 deferring constant output in varasm.c. */
1296 register tree s = make_node (STRING_CST);
1297 TREE_STRING_LENGTH (s) = len;
1298 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1302 /* Return a newly constructed COMPLEX_CST node whose value is
1303 specified by the real and imaginary parts REAL and IMAG.
1304 Both REAL and IMAG should be constant nodes.
1305 The TREE_TYPE is not initialized. */
1308 build_complex (real, imag)
1311 register tree t = make_node (COMPLEX_CST);
1312 TREE_REALPART (t) = real;
1313 TREE_IMAGPART (t) = imag;
1314 TREE_TYPE (t) = build_complex_type (TREE_TYPE (real));
1318 /* Build a newly constructed TREE_VEC node of length LEN. */
1324 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1325 register struct obstack *obstack = current_obstack;
1328 #ifdef GATHER_STATISTICS
1329 tree_node_counts[(int)vec_kind]++;
1330 tree_node_sizes[(int)vec_kind] += length;
1333 t = (tree) obstack_alloc (obstack, length);
1335 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1338 TREE_SET_CODE (t, TREE_VEC);
1339 TREE_VEC_LENGTH (t) = len;
1340 if (obstack == &permanent_obstack)
1341 TREE_PERMANENT (t) = 1;
1346 /* Return 1 if EXPR is the integer constant zero. */
1349 integer_zerop (expr)
1354 return (TREE_CODE (expr) == INTEGER_CST
1355 && TREE_INT_CST_LOW (expr) == 0
1356 && TREE_INT_CST_HIGH (expr) == 0);
1359 /* Return 1 if EXPR is the integer constant one. */
1367 return (TREE_CODE (expr) == INTEGER_CST
1368 && TREE_INT_CST_LOW (expr) == 1
1369 && TREE_INT_CST_HIGH (expr) == 0);
1372 /* Return 1 if EXPR is an integer containing all 1's
1373 in as much precision as it contains. */
1376 integer_all_onesp (expr)
1384 if (TREE_CODE (expr) != INTEGER_CST)
1387 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1389 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1391 prec = TYPE_PRECISION (TREE_TYPE (expr));
1392 if (prec >= HOST_BITS_PER_WIDE_INT)
1394 int high_value, shift_amount;
1396 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1398 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1399 /* Can not handle precisions greater than twice the host int size. */
1401 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1402 /* Shifting by the host word size is undefined according to the ANSI
1403 standard, so we must handle this as a special case. */
1406 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1408 return TREE_INT_CST_LOW (expr) == -1
1409 && TREE_INT_CST_HIGH (expr) == high_value;
1412 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1415 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1419 integer_pow2p (expr)
1422 HOST_WIDE_INT high, low;
1426 if (TREE_CODE (expr) != INTEGER_CST)
1429 high = TREE_INT_CST_HIGH (expr);
1430 low = TREE_INT_CST_LOW (expr);
1432 if (high == 0 && low == 0)
1435 return ((high == 0 && (low & (low - 1)) == 0)
1436 || (low == 0 && (high & (high - 1)) == 0));
1439 /* Return 1 if EXPR is the real constant zero. */
1447 return (TREE_CODE (expr) == REAL_CST
1448 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0));
1451 /* Return 1 if EXPR is the real constant one. */
1459 return (TREE_CODE (expr) == REAL_CST
1460 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1));
1463 /* Return 1 if EXPR is the real constant two. */
1471 return (TREE_CODE (expr) == REAL_CST
1472 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2));
1475 /* Nonzero if EXP is a constant or a cast of a constant. */
1478 really_constant_p (exp)
1481 /* This is not quite the same as STRIP_NOPS. It does more. */
1482 while (TREE_CODE (exp) == NOP_EXPR
1483 || TREE_CODE (exp) == CONVERT_EXPR
1484 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1485 exp = TREE_OPERAND (exp, 0);
1486 return TREE_CONSTANT (exp);
1489 /* Return first list element whose TREE_VALUE is ELEM.
1490 Return 0 if ELEM is not it LIST. */
1493 value_member (elem, list)
1498 if (elem == TREE_VALUE (list))
1500 list = TREE_CHAIN (list);
1505 /* Return first list element whose TREE_PURPOSE is ELEM.
1506 Return 0 if ELEM is not it LIST. */
1509 purpose_member (elem, list)
1514 if (elem == TREE_PURPOSE (list))
1516 list = TREE_CHAIN (list);
1521 /* Return first list element whose BINFO_TYPE is ELEM.
1522 Return 0 if ELEM is not it LIST. */
1525 binfo_member (elem, list)
1530 if (elem == BINFO_TYPE (list))
1532 list = TREE_CHAIN (list);
1537 /* Return nonzero if ELEM is part of the chain CHAIN. */
1540 chain_member (elem, chain)
1547 chain = TREE_CHAIN (chain);
1553 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1554 We expect a null pointer to mark the end of the chain.
1555 This is the Lisp primitive `length'. */
1562 register int len = 0;
1564 for (tail = t; tail; tail = TREE_CHAIN (tail))
1570 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1571 by modifying the last node in chain 1 to point to chain 2.
1572 This is the Lisp primitive `nconc'. */
1584 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1586 TREE_CHAIN (t1) = op2;
1587 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1589 abort (); /* Circularity created. */
1595 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1599 register tree chain;
1603 while (next = TREE_CHAIN (chain))
1608 /* Reverse the order of elements in the chain T,
1609 and return the new head of the chain (old last element). */
1615 register tree prev = 0, decl, next;
1616 for (decl = t; decl; decl = next)
1618 next = TREE_CHAIN (decl);
1619 TREE_CHAIN (decl) = prev;
1625 /* Given a chain CHAIN of tree nodes,
1626 construct and return a list of those nodes. */
1632 tree result = NULL_TREE;
1633 tree in_tail = chain;
1634 tree out_tail = NULL_TREE;
1638 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1640 TREE_CHAIN (out_tail) = next;
1644 in_tail = TREE_CHAIN (in_tail);
1650 /* Return a newly created TREE_LIST node whose
1651 purpose and value fields are PARM and VALUE. */
1654 build_tree_list (parm, value)
1657 register tree t = make_node (TREE_LIST);
1658 TREE_PURPOSE (t) = parm;
1659 TREE_VALUE (t) = value;
1663 /* Similar, but build on the temp_decl_obstack. */
1666 build_decl_list (parm, value)
1670 register struct obstack *ambient_obstack = current_obstack;
1671 current_obstack = &temp_decl_obstack;
1672 node = build_tree_list (parm, value);
1673 current_obstack = ambient_obstack;
1677 /* Return a newly created TREE_LIST node whose
1678 purpose and value fields are PARM and VALUE
1679 and whose TREE_CHAIN is CHAIN. */
1682 tree_cons (purpose, value, chain)
1683 tree purpose, value, chain;
1686 register tree node = make_node (TREE_LIST);
1689 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
1690 #ifdef GATHER_STATISTICS
1691 tree_node_counts[(int)x_kind]++;
1692 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
1695 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
1696 ((int *) node)[i] = 0;
1698 TREE_SET_CODE (node, TREE_LIST);
1699 if (current_obstack == &permanent_obstack)
1700 TREE_PERMANENT (node) = 1;
1703 TREE_CHAIN (node) = chain;
1704 TREE_PURPOSE (node) = purpose;
1705 TREE_VALUE (node) = value;
1709 /* Similar, but build on the temp_decl_obstack. */
1712 decl_tree_cons (purpose, value, chain)
1713 tree purpose, value, chain;
1716 register struct obstack *ambient_obstack = current_obstack;
1717 current_obstack = &temp_decl_obstack;
1718 node = tree_cons (purpose, value, chain);
1719 current_obstack = ambient_obstack;
1723 /* Same as `tree_cons' but make a permanent object. */
1726 perm_tree_cons (purpose, value, chain)
1727 tree purpose, value, chain;
1730 register struct obstack *ambient_obstack = current_obstack;
1731 current_obstack = &permanent_obstack;
1733 node = tree_cons (purpose, value, chain);
1734 current_obstack = ambient_obstack;
1738 /* Same as `tree_cons', but make this node temporary, regardless. */
1741 temp_tree_cons (purpose, value, chain)
1742 tree purpose, value, chain;
1745 register struct obstack *ambient_obstack = current_obstack;
1746 current_obstack = &temporary_obstack;
1748 node = tree_cons (purpose, value, chain);
1749 current_obstack = ambient_obstack;
1753 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
1756 saveable_tree_cons (purpose, value, chain)
1757 tree purpose, value, chain;
1760 register struct obstack *ambient_obstack = current_obstack;
1761 current_obstack = saveable_obstack;
1763 node = tree_cons (purpose, value, chain);
1764 current_obstack = ambient_obstack;
1768 /* Return the size nominally occupied by an object of type TYPE
1769 when it resides in memory. The value is measured in units of bytes,
1770 and its data type is that normally used for type sizes
1771 (which is the first type created by make_signed_type or
1772 make_unsigned_type). */
1775 size_in_bytes (type)
1780 if (type == error_mark_node)
1781 return integer_zero_node;
1782 type = TYPE_MAIN_VARIANT (type);
1783 if (TYPE_SIZE (type) == 0)
1785 incomplete_type_error (NULL_TREE, type);
1786 return integer_zero_node;
1788 t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1789 size_int (BITS_PER_UNIT));
1790 if (TREE_CODE (t) == INTEGER_CST)
1791 force_fit_type (t, 0);
1795 /* Return the size of TYPE (in bytes) as an integer,
1796 or return -1 if the size can vary. */
1799 int_size_in_bytes (type)
1803 if (type == error_mark_node)
1805 type = TYPE_MAIN_VARIANT (type);
1806 if (TYPE_SIZE (type) == 0)
1808 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1810 if (TREE_INT_CST_HIGH (TYPE_SIZE (type)) != 0)
1812 tree t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1813 size_int (BITS_PER_UNIT));
1814 return TREE_INT_CST_LOW (t);
1816 size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1817 return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1820 /* Return, as a tree node, the number of elements for TYPE (which is an
1821 ARRAY_TYPE) minus one. This counts only elements of the top array. */
1824 array_type_nelts (type)
1827 tree index_type = TYPE_DOMAIN (type);
1829 return (integer_zerop (TYPE_MIN_VALUE (index_type))
1830 ? TYPE_MAX_VALUE (index_type)
1831 : fold (build (MINUS_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)),
1832 TYPE_MAX_VALUE (index_type),
1833 TYPE_MIN_VALUE (index_type))));
1836 /* Return nonzero if arg is static -- a reference to an object in
1837 static storage. This is not the same as the C meaning of `static'. */
1843 switch (TREE_CODE (arg))
1847 return TREE_STATIC (arg) || DECL_EXTERNAL (arg);
1850 return TREE_STATIC (arg);
1857 return staticp (TREE_OPERAND (arg, 0));
1860 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
1863 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1864 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1865 return staticp (TREE_OPERAND (arg, 0));
1871 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
1872 Do this to any expression which may be used in more than one place,
1873 but must be evaluated only once.
1875 Normally, expand_expr would reevaluate the expression each time.
1876 Calling save_expr produces something that is evaluated and recorded
1877 the first time expand_expr is called on it. Subsequent calls to
1878 expand_expr just reuse the recorded value.
1880 The call to expand_expr that generates code that actually computes
1881 the value is the first call *at compile time*. Subsequent calls
1882 *at compile time* generate code to use the saved value.
1883 This produces correct result provided that *at run time* control
1884 always flows through the insns made by the first expand_expr
1885 before reaching the other places where the save_expr was evaluated.
1886 You, the caller of save_expr, must make sure this is so.
1888 Constants, and certain read-only nodes, are returned with no
1889 SAVE_EXPR because that is safe. Expressions containing placeholders
1890 are not touched; see tree.def for an explanation of what these
1897 register tree t = fold (expr);
1899 /* We don't care about whether this can be used as an lvalue in this
1901 while (TREE_CODE (t) == NON_LVALUE_EXPR)
1902 t = TREE_OPERAND (t, 0);
1904 /* If the tree evaluates to a constant, then we don't want to hide that
1905 fact (i.e. this allows further folding, and direct checks for constants).
1906 However, a read-only object that has side effects cannot be bypassed.
1907 Since it is no problem to reevaluate literals, we just return the
1910 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
1911 || TREE_CODE (t) == SAVE_EXPR)
1914 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
1915 it means that the size or offset of some field of an object depends on
1916 the value within another field.
1918 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
1919 and some variable since it would then need to be both evaluated once and
1920 evaluated more than once. Front-ends must assure this case cannot
1921 happen by surrounding any such subexpressions in their own SAVE_EXPR
1922 and forcing evaluation at the proper time. */
1923 if (contains_placeholder_p (t))
1926 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
1928 /* This expression might be placed ahead of a jump to ensure that the
1929 value was computed on both sides of the jump. So make sure it isn't
1930 eliminated as dead. */
1931 TREE_SIDE_EFFECTS (t) = 1;
1935 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
1936 or offset that depends on a field within a record.
1938 Note that we only allow such expressions within simple arithmetic
1942 contains_placeholder_p (exp)
1945 register enum tree_code code = TREE_CODE (exp);
1948 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
1949 in it since it is supplying a value for it. */
1950 if (code == WITH_RECORD_EXPR)
1953 switch (TREE_CODE_CLASS (code))
1956 for (inner = TREE_OPERAND (exp, 0);
1957 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
1958 inner = TREE_OPERAND (inner, 0))
1960 return TREE_CODE (inner) == PLACEHOLDER_EXPR;
1965 switch (tree_code_length[(int) code])
1968 return contains_placeholder_p (TREE_OPERAND (exp, 0));
1970 return (code != RTL_EXPR
1971 && code != CONSTRUCTOR
1972 && ! (code == SAVE_EXPR && SAVE_EXPR_RTL (exp) != 0)
1973 && code != WITH_RECORD_EXPR
1974 && (contains_placeholder_p (TREE_OPERAND (exp, 0))
1975 || contains_placeholder_p (TREE_OPERAND (exp, 1))));
1977 return (code == COND_EXPR
1978 && (contains_placeholder_p (TREE_OPERAND (exp, 0))
1979 || contains_placeholder_p (TREE_OPERAND (exp, 1))
1980 || contains_placeholder_p (TREE_OPERAND (exp, 2))));
1987 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
1988 return a tree with all occurrences of references to F in a
1989 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
1990 contains only arithmetic expressions. */
1993 substitute_in_expr (exp, f, r)
1998 enum tree_code code = TREE_CODE (exp);
2001 switch (TREE_CODE_CLASS (code))
2008 if (code == PLACEHOLDER_EXPR)
2016 switch (tree_code_length[(int) code])
2019 return fold (build1 (code, TREE_TYPE (exp),
2020 substitute_in_expr (TREE_OPERAND (exp, 0),
2024 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2025 could, but we don't support it. */
2026 if (code == RTL_EXPR)
2028 else if (code == CONSTRUCTOR)
2031 return fold (build (code, TREE_TYPE (exp),
2032 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2033 substitute_in_expr (TREE_OPERAND (exp, 1),
2037 /* It cannot be that anything inside a SAVE_EXPR contains a
2038 PLACEHOLDER_EXPR. */
2039 if (code == SAVE_EXPR)
2042 if (code != COND_EXPR)
2045 return fold (build (code, TREE_TYPE (exp),
2046 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2047 substitute_in_expr (TREE_OPERAND (exp, 1), f, r),
2048 substitute_in_expr (TREE_OPERAND (exp, 2),
2058 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2059 and it is the right field, replace it with R. */
2060 for (inner = TREE_OPERAND (exp, 0);
2061 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2062 inner = TREE_OPERAND (inner, 0))
2064 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2065 && TREE_OPERAND (exp, 1) == f)
2068 return fold (build (code, TREE_TYPE (exp),
2069 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2070 TREE_OPERAND (exp, 1)));
2072 return fold (build (code, TREE_TYPE (exp),
2073 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2074 substitute_in_expr (TREE_OPERAND (exp, 1), f, r),
2075 substitute_in_expr (TREE_OPERAND (exp, 2), f, r)));
2078 return fold (build1 (code, TREE_TYPE (exp),
2079 substitute_in_expr (TREE_OPERAND (exp, 0),
2082 return fold (build (code, TREE_TYPE (exp),
2083 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2084 substitute_in_expr (TREE_OPERAND (exp, 1), f, r)));
2088 /* If it wasn't one of the cases we handle, give up. */
2093 /* Given a type T, a FIELD_DECL F, and a replacement value R,
2094 return a new type with all size expressions that contain F
2095 updated by replacing F with R. */
2098 substitute_in_type (t, f, r)
2101 switch (TREE_CODE (t))
2110 if ((TREE_CODE (TYPE_MIN_VALUE (t)) != INTEGER_CST
2111 && contains_placeholder_p (TYPE_MIN_VALUE (t)))
2112 || (TREE_CODE (TYPE_MAX_VALUE (t)) != INTEGER_CST
2113 && contains_placeholder_p (TYPE_MAX_VALUE (t))))
2114 return build_range_type (t,
2115 substitute_in_expr (TYPE_MIN_VALUE (t), f, r),
2116 substitute_in_expr (TYPE_MAX_VALUE (t), f, r));
2120 if ((TYPE_MIN_VALUE (t) != 0
2121 && TREE_CODE (TYPE_MIN_VALUE (t)) != REAL_CST
2122 && contains_placeholder_p (TYPE_MIN_VALUE (t)))
2123 || (TYPE_MAX_VALUE (t) != 0
2124 && TREE_CODE (TYPE_MAX_VALUE (t)) != REAL_CST
2125 && contains_placeholder_p (TYPE_MAX_VALUE (t))))
2129 if (TYPE_MIN_VALUE (t))
2130 TYPE_MIN_VALUE (t) = substitute_in_expr (TYPE_MIN_VALUE (t), f, r);
2131 if (TYPE_MAX_VALUE (t))
2132 TYPE_MAX_VALUE (t) = substitute_in_expr (TYPE_MAX_VALUE (t), f, r);
2137 return build_complex_type (substitute_in_type (TREE_TYPE (t), f, r));
2141 case REFERENCE_TYPE:
2146 /* Don't know how to do these yet. */
2150 t = build_array_type (substitute_in_type (TREE_TYPE (t), f, r),
2151 substitute_in_type (TYPE_DOMAIN (t), f, r));
2158 case QUAL_UNION_TYPE:
2160 tree new = copy_node (t);
2162 tree last_field = 0;
2164 /* Start out with no fields, make new fields, and chain them
2167 TYPE_FIELDS (new) = 0;
2168 TYPE_SIZE (new) = 0;
2170 for (field = TYPE_FIELDS (t); field;
2171 field = TREE_CHAIN (field))
2173 tree new_field = copy_node (field);
2175 TREE_TYPE (new_field)
2176 = substitute_in_type (TREE_TYPE (new_field), f, r);
2178 /* If this is an anonymous field and the type of this field is
2179 a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If
2180 the type just has one element, treat that as the field.
2181 But don't do this if we are processing a QUAL_UNION_TYPE. */
2182 if (TREE_CODE (t) != QUAL_UNION_TYPE && DECL_NAME (new_field) == 0
2183 && (TREE_CODE (TREE_TYPE (new_field)) == UNION_TYPE
2184 || TREE_CODE (TREE_TYPE (new_field)) == RECORD_TYPE))
2186 if (TYPE_FIELDS (TREE_TYPE (new_field)) == 0)
2189 if (TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new_field))) == 0)
2190 new_field = TYPE_FIELDS (TREE_TYPE (new_field));
2193 DECL_CONTEXT (new_field) = new;
2194 DECL_SIZE (new_field) = 0;
2196 if (TREE_CODE (t) == QUAL_UNION_TYPE)
2198 /* Do the substitution inside the qualifier and if we find
2199 that this field will not be present, omit it. */
2200 DECL_QUALIFIER (new_field)
2201 = substitute_in_expr (DECL_QUALIFIER (field), f, r);
2202 if (integer_zerop (DECL_QUALIFIER (new_field)))
2206 if (last_field == 0)
2207 TYPE_FIELDS (new) = new_field;
2209 TREE_CHAIN (last_field) = new_field;
2211 last_field = new_field;
2213 /* If this is a qualified type and this field will always be
2214 present, we are done. */
2215 if (TREE_CODE (t) == QUAL_UNION_TYPE
2216 && integer_onep (DECL_QUALIFIER (new_field)))
2220 /* If this used to be a qualified union type, but we now know what
2221 field will be present, make this a normal union. */
2222 if (TREE_CODE (new) == QUAL_UNION_TYPE
2223 && (TYPE_FIELDS (new) == 0
2224 || integer_onep (DECL_QUALIFIER (TYPE_FIELDS (new)))))
2225 TREE_SET_CODE (new, UNION_TYPE);
2233 /* Stabilize a reference so that we can use it any number of times
2234 without causing its operands to be evaluated more than once.
2235 Returns the stabilized reference. This works by means of save_expr,
2236 so see the caveats in the comments about save_expr.
2238 Also allows conversion expressions whose operands are references.
2239 Any other kind of expression is returned unchanged. */
2242 stabilize_reference (ref)
2245 register tree result;
2246 register enum tree_code code = TREE_CODE (ref);
2253 /* No action is needed in this case. */
2259 case FIX_TRUNC_EXPR:
2260 case FIX_FLOOR_EXPR:
2261 case FIX_ROUND_EXPR:
2263 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2267 result = build_nt (INDIRECT_REF,
2268 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2272 result = build_nt (COMPONENT_REF,
2273 stabilize_reference (TREE_OPERAND (ref, 0)),
2274 TREE_OPERAND (ref, 1));
2278 result = build_nt (BIT_FIELD_REF,
2279 stabilize_reference (TREE_OPERAND (ref, 0)),
2280 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2281 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2285 result = build_nt (ARRAY_REF,
2286 stabilize_reference (TREE_OPERAND (ref, 0)),
2287 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2290 /* If arg isn't a kind of lvalue we recognize, make no change.
2291 Caller should recognize the error for an invalid lvalue. */
2296 return error_mark_node;
2299 TREE_TYPE (result) = TREE_TYPE (ref);
2300 TREE_READONLY (result) = TREE_READONLY (ref);
2301 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2302 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2303 TREE_RAISES (result) = TREE_RAISES (ref);
2308 /* Subroutine of stabilize_reference; this is called for subtrees of
2309 references. Any expression with side-effects must be put in a SAVE_EXPR
2310 to ensure that it is only evaluated once.
2312 We don't put SAVE_EXPR nodes around everything, because assigning very
2313 simple expressions to temporaries causes us to miss good opportunities
2314 for optimizations. Among other things, the opportunity to fold in the
2315 addition of a constant into an addressing mode often gets lost, e.g.
2316 "y[i+1] += x;". In general, we take the approach that we should not make
2317 an assignment unless we are forced into it - i.e., that any non-side effect
2318 operator should be allowed, and that cse should take care of coalescing
2319 multiple utterances of the same expression should that prove fruitful. */
2322 stabilize_reference_1 (e)
2325 register tree result;
2326 register int length;
2327 register enum tree_code code = TREE_CODE (e);
2329 /* We cannot ignore const expressions because it might be a reference
2330 to a const array but whose index contains side-effects. But we can
2331 ignore things that are actual constant or that already have been
2332 handled by this function. */
2334 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2337 switch (TREE_CODE_CLASS (code))
2347 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2348 so that it will only be evaluated once. */
2349 /* The reference (r) and comparison (<) classes could be handled as
2350 below, but it is generally faster to only evaluate them once. */
2351 if (TREE_SIDE_EFFECTS (e))
2352 return save_expr (e);
2356 /* Constants need no processing. In fact, we should never reach
2361 /* Division is slow and tends to be compiled with jumps,
2362 especially the division by powers of 2 that is often
2363 found inside of an array reference. So do it just once. */
2364 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2365 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2366 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2367 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2368 return save_expr (e);
2369 /* Recursively stabilize each operand. */
2370 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2371 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2375 /* Recursively stabilize each operand. */
2376 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2380 TREE_TYPE (result) = TREE_TYPE (e);
2381 TREE_READONLY (result) = TREE_READONLY (e);
2382 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2383 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2384 TREE_RAISES (result) = TREE_RAISES (e);
2389 /* Low-level constructors for expressions. */
2391 /* Build an expression of code CODE, data type TYPE,
2392 and operands as specified by the arguments ARG1 and following arguments.
2393 Expressions and reference nodes can be created this way.
2394 Constants, decls, types and misc nodes cannot be. */
2397 build VPROTO((enum tree_code code, tree tt, ...))
2400 enum tree_code code;
2405 register int length;
2411 code = va_arg (p, enum tree_code);
2412 tt = va_arg (p, tree);
2415 t = make_node (code);
2416 length = tree_code_length[(int) code];
2421 /* This is equivalent to the loop below, but faster. */
2422 register tree arg0 = va_arg (p, tree);
2423 register tree arg1 = va_arg (p, tree);
2424 TREE_OPERAND (t, 0) = arg0;
2425 TREE_OPERAND (t, 1) = arg1;
2426 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
2427 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
2428 TREE_SIDE_EFFECTS (t) = 1;
2430 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
2432 else if (length == 1)
2434 register tree arg0 = va_arg (p, tree);
2436 /* Call build1 for this! */
2437 if (TREE_CODE_CLASS (code) != 's')
2439 TREE_OPERAND (t, 0) = arg0;
2440 if (arg0 && TREE_SIDE_EFFECTS (arg0))
2441 TREE_SIDE_EFFECTS (t) = 1;
2442 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
2446 for (i = 0; i < length; i++)
2448 register tree operand = va_arg (p, tree);
2449 TREE_OPERAND (t, i) = operand;
2452 if (TREE_SIDE_EFFECTS (operand))
2453 TREE_SIDE_EFFECTS (t) = 1;
2454 if (TREE_RAISES (operand))
2455 TREE_RAISES (t) = 1;
2463 /* Same as above, but only builds for unary operators.
2464 Saves lions share of calls to `build'; cuts down use
2465 of varargs, which is expensive for RISC machines. */
2467 build1 (code, type, node)
2468 enum tree_code code;
2472 register struct obstack *obstack = current_obstack;
2473 register int i, length;
2474 register tree_node_kind kind;
2477 #ifdef GATHER_STATISTICS
2478 if (TREE_CODE_CLASS (code) == 'r')
2484 obstack = expression_obstack;
2485 length = sizeof (struct tree_exp);
2487 t = (tree) obstack_alloc (obstack, length);
2489 #ifdef GATHER_STATISTICS
2490 tree_node_counts[(int)kind]++;
2491 tree_node_sizes[(int)kind] += length;
2494 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
2497 TREE_TYPE (t) = type;
2498 TREE_SET_CODE (t, code);
2500 if (obstack == &permanent_obstack)
2501 TREE_PERMANENT (t) = 1;
2503 TREE_OPERAND (t, 0) = node;
2506 if (TREE_SIDE_EFFECTS (node))
2507 TREE_SIDE_EFFECTS (t) = 1;
2508 if (TREE_RAISES (node))
2509 TREE_RAISES (t) = 1;
2515 /* Similar except don't specify the TREE_TYPE
2516 and leave the TREE_SIDE_EFFECTS as 0.
2517 It is permissible for arguments to be null,
2518 or even garbage if their values do not matter. */
2521 build_nt VPROTO((register enum tree_code code, ...))
2524 register enum tree_code code;
2528 register int length;
2534 code = va_arg (p, enum tree_code);
2537 t = make_node (code);
2538 length = tree_code_length[(int) code];
2540 for (i = 0; i < length; i++)
2541 TREE_OPERAND (t, i) = va_arg (p, tree);
2547 /* Similar to `build_nt', except we build
2548 on the temp_decl_obstack, regardless. */
2551 build_parse_node VPROTO((register enum tree_code code, ...))
2554 register enum tree_code code;
2556 register struct obstack *ambient_obstack = expression_obstack;
2559 register int length;
2565 code = va_arg (p, enum tree_code);
2568 expression_obstack = &temp_decl_obstack;
2570 t = make_node (code);
2571 length = tree_code_length[(int) code];
2573 for (i = 0; i < length; i++)
2574 TREE_OPERAND (t, i) = va_arg (p, tree);
2577 expression_obstack = ambient_obstack;
2582 /* Commented out because this wants to be done very
2583 differently. See cp-lex.c. */
2585 build_op_identifier (op1, op2)
2588 register tree t = make_node (OP_IDENTIFIER);
2589 TREE_PURPOSE (t) = op1;
2590 TREE_VALUE (t) = op2;
2595 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
2596 We do NOT enter this node in any sort of symbol table.
2598 layout_decl is used to set up the decl's storage layout.
2599 Other slots are initialized to 0 or null pointers. */
2602 build_decl (code, name, type)
2603 enum tree_code code;
2608 t = make_node (code);
2610 /* if (type == error_mark_node)
2611 type = integer_type_node; */
2612 /* That is not done, deliberately, so that having error_mark_node
2613 as the type can suppress useless errors in the use of this variable. */
2615 DECL_NAME (t) = name;
2616 DECL_ASSEMBLER_NAME (t) = name;
2617 TREE_TYPE (t) = type;
2619 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
2621 else if (code == FUNCTION_DECL)
2622 DECL_MODE (t) = FUNCTION_MODE;
2627 /* BLOCK nodes are used to represent the structure of binding contours
2628 and declarations, once those contours have been exited and their contents
2629 compiled. This information is used for outputting debugging info. */
2632 build_block (vars, tags, subblocks, supercontext, chain)
2633 tree vars, tags, subblocks, supercontext, chain;
2635 register tree block = make_node (BLOCK);
2636 BLOCK_VARS (block) = vars;
2637 BLOCK_TYPE_TAGS (block) = tags;
2638 BLOCK_SUBBLOCKS (block) = subblocks;
2639 BLOCK_SUPERCONTEXT (block) = supercontext;
2640 BLOCK_CHAIN (block) = chain;
2644 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
2645 and its TYPE_VOLATILE is VOLATILEP.
2647 Such variant types already made are recorded so that duplicates
2650 A variant types should never be used as the type of an expression.
2651 Always copy the variant information into the TREE_READONLY
2652 and TREE_THIS_VOLATILE of the expression, and then give the expression
2653 as its type the "main variant", the variant whose TYPE_READONLY
2654 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
2658 build_type_variant (type, constp, volatilep)
2660 int constp, volatilep;
2664 /* Treat any nonzero argument as 1. */
2666 volatilep = !!volatilep;
2668 /* If not generating auxiliary info, search the chain of variants to see
2669 if there is already one there just like the one we need to have. If so,
2670 use that existing one.
2672 We don't do this in the case where we are generating aux info because
2673 in that case we want each typedef names to get it's own distinct type
2674 node, even if the type of this new typedef is the same as some other
2677 if (!flag_gen_aux_info)
2678 for (t = TYPE_MAIN_VARIANT(type); t; t = TYPE_NEXT_VARIANT (t))
2679 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t))
2682 /* We need a new one. */
2684 t = build_type_copy (type);
2685 TYPE_READONLY (t) = constp;
2686 TYPE_VOLATILE (t) = volatilep;
2691 /* Give TYPE a new main variant: NEW_MAIN.
2692 This is the right thing to do only when something else
2693 about TYPE is modified in place. */
2696 change_main_variant (type, new_main)
2697 tree type, new_main;
2700 tree omain = TYPE_MAIN_VARIANT (type);
2702 /* Remove TYPE from the TYPE_NEXT_VARIANT chain of its main variant. */
2703 if (TYPE_NEXT_VARIANT (omain) == type)
2704 TYPE_NEXT_VARIANT (omain) = TYPE_NEXT_VARIANT (type);
2706 for (t = TYPE_NEXT_VARIANT (omain); t && TYPE_NEXT_VARIANT (t);
2707 t = TYPE_NEXT_VARIANT (t))
2708 if (TYPE_NEXT_VARIANT (t) == type)
2710 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (type);
2714 TYPE_MAIN_VARIANT (type) = new_main;
2715 TYPE_NEXT_VARIANT (type) = TYPE_NEXT_VARIANT (new_main);
2716 TYPE_NEXT_VARIANT (new_main) = type;
2719 /* Create a new variant of TYPE, equivalent but distinct.
2720 This is so the caller can modify it. */
2723 build_type_copy (type)
2726 register tree t, m = TYPE_MAIN_VARIANT (type);
2727 register struct obstack *ambient_obstack = current_obstack;
2729 current_obstack = TYPE_OBSTACK (type);
2730 t = copy_node (type);
2731 current_obstack = ambient_obstack;
2733 TYPE_POINTER_TO (t) = 0;
2734 TYPE_REFERENCE_TO (t) = 0;
2736 /* Add this type to the chain of variants of TYPE. */
2737 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2738 TYPE_NEXT_VARIANT (m) = t;
2743 /* Hashing of types so that we don't make duplicates.
2744 The entry point is `type_hash_canon'. */
2746 /* Each hash table slot is a bucket containing a chain
2747 of these structures. */
2751 struct type_hash *next; /* Next structure in the bucket. */
2752 int hashcode; /* Hash code of this type. */
2753 tree type; /* The type recorded here. */
2756 /* Now here is the hash table. When recording a type, it is added
2757 to the slot whose index is the hash code mod the table size.
2758 Note that the hash table is used for several kinds of types
2759 (function types, array types and array index range types, for now).
2760 While all these live in the same table, they are completely independent,
2761 and the hash code is computed differently for each of these. */
2763 #define TYPE_HASH_SIZE 59
2764 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
2766 /* Here is how primitive or already-canonicalized types' hash
2768 #define TYPE_HASH(TYPE) ((HOST_WIDE_INT) (TYPE) & 0777777)
2770 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
2771 with types in the TREE_VALUE slots), by adding the hash codes
2772 of the individual types. */
2775 type_hash_list (list)
2778 register int hashcode;
2780 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
2781 hashcode += TYPE_HASH (TREE_VALUE (tail));
2785 /* Look in the type hash table for a type isomorphic to TYPE.
2786 If one is found, return it. Otherwise return 0. */
2789 type_hash_lookup (hashcode, type)
2793 register struct type_hash *h;
2794 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
2795 if (h->hashcode == hashcode
2796 && TREE_CODE (h->type) == TREE_CODE (type)
2797 && TREE_TYPE (h->type) == TREE_TYPE (type)
2798 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
2799 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
2800 TYPE_MAX_VALUE (type)))
2801 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
2802 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
2803 TYPE_MIN_VALUE (type)))
2804 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
2805 || (TYPE_DOMAIN (h->type)
2806 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
2807 && TYPE_DOMAIN (type)
2808 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
2809 && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
2814 /* Add an entry to the type-hash-table
2815 for a type TYPE whose hash code is HASHCODE. */
2818 type_hash_add (hashcode, type)
2822 register struct type_hash *h;
2824 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
2825 h->hashcode = hashcode;
2827 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
2828 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
2831 /* Given TYPE, and HASHCODE its hash code, return the canonical
2832 object for an identical type if one already exists.
2833 Otherwise, return TYPE, and record it as the canonical object
2834 if it is a permanent object.
2836 To use this function, first create a type of the sort you want.
2837 Then compute its hash code from the fields of the type that
2838 make it different from other similar types.
2839 Then call this function and use the value.
2840 This function frees the type you pass in if it is a duplicate. */
2842 /* Set to 1 to debug without canonicalization. Never set by program. */
2843 int debug_no_type_hash = 0;
2846 type_hash_canon (hashcode, type)
2852 if (debug_no_type_hash)
2855 t1 = type_hash_lookup (hashcode, type);
2858 obstack_free (TYPE_OBSTACK (type), type);
2859 #ifdef GATHER_STATISTICS
2860 tree_node_counts[(int)t_kind]--;
2861 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
2866 /* If this is a permanent type, record it for later reuse. */
2867 if (TREE_PERMANENT (type))
2868 type_hash_add (hashcode, type);
2873 /* Given two lists of types
2874 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
2875 return 1 if the lists contain the same types in the same order.
2876 Also, the TREE_PURPOSEs must match. */
2879 type_list_equal (l1, l2)
2882 register tree t1, t2;
2883 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
2885 if (TREE_VALUE (t1) != TREE_VALUE (t2))
2887 if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2))
2889 int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
2900 /* Nonzero if integer constants T1 and T2
2901 represent the same constant value. */
2904 tree_int_cst_equal (t1, t2)
2909 if (t1 == 0 || t2 == 0)
2911 if (TREE_CODE (t1) == INTEGER_CST
2912 && TREE_CODE (t2) == INTEGER_CST
2913 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2914 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
2919 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
2920 The precise way of comparison depends on their data type. */
2923 tree_int_cst_lt (t1, t2)
2929 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
2930 return INT_CST_LT (t1, t2);
2931 return INT_CST_LT_UNSIGNED (t1, t2);
2934 /* Compare two constructor-element-type constants. */
2936 simple_cst_list_equal (l1, l2)
2939 while (l1 != NULL_TREE && l2 != NULL_TREE)
2941 int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2));
2946 l1 = TREE_CHAIN (l1);
2947 l2 = TREE_CHAIN (l2);
2952 /* Return truthvalue of whether T1 is the same tree structure as T2.
2953 Return 1 if they are the same.
2954 Return 0 if they are understandably different.
2955 Return -1 if either contains tree structure not understood by
2959 simple_cst_equal (t1, t2)
2962 register enum tree_code code1, code2;
2967 if (t1 == 0 || t2 == 0)
2970 code1 = TREE_CODE (t1);
2971 code2 = TREE_CODE (t2);
2973 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
2974 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
2975 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2977 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
2978 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
2979 || code2 == NON_LVALUE_EXPR)
2980 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
2988 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2989 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
2992 return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2995 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2996 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2997 TREE_STRING_LENGTH (t1));
3003 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3006 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3009 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3012 /* Special case: if either target is an unallocated VAR_DECL,
3013 it means that it's going to be unified with whatever the
3014 TARGET_EXPR is really supposed to initialize, so treat it
3015 as being equivalent to anything. */
3016 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
3017 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
3018 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
3019 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
3020 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
3021 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
3024 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3027 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3029 case WITH_CLEANUP_EXPR:
3030 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3033 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
3036 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
3037 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3047 /* This general rule works for most tree codes.
3048 All exceptions should be handled above. */
3050 switch (TREE_CODE_CLASS (code1))
3060 for (i=0; i<tree_code_length[(int) code1]; ++i)
3062 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
3072 /* Constructors for pointer, array and function types.
3073 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
3074 constructed by language-dependent code, not here.) */
3076 /* Construct, lay out and return the type of pointers to TO_TYPE.
3077 If such a type has already been constructed, reuse it. */
3080 build_pointer_type (to_type)
3083 register tree t = TYPE_POINTER_TO (to_type);
3085 /* First, if we already have a type for pointers to TO_TYPE, use it. */
3090 /* We need a new one. Put this in the same obstack as TO_TYPE. */
3091 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
3092 t = make_node (POINTER_TYPE);
3095 TREE_TYPE (t) = to_type;
3097 /* Record this type as the pointer to TO_TYPE. */
3098 TYPE_POINTER_TO (to_type) = t;
3100 /* Lay out the type. This function has many callers that are concerned
3101 with expression-construction, and this simplifies them all.
3102 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
3108 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
3109 MAXVAL should be the maximum value in the domain
3110 (one less than the length of the array). */
3113 build_index_type (maxval)
3116 register tree itype = make_node (INTEGER_TYPE);
3117 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
3118 TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
3119 TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
3120 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
3121 TYPE_MODE (itype) = TYPE_MODE (sizetype);
3122 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
3123 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
3124 if (TREE_CODE (maxval) == INTEGER_CST)
3126 int maxint = (int) TREE_INT_CST_LOW (maxval);
3127 /* If the domain should be empty, make sure the maxval
3128 remains -1 and is not spoiled by truncation. */
3129 if (INT_CST_LT (maxval, integer_zero_node))
3131 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
3132 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
3134 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
3140 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
3141 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
3142 low bound LOWVAL and high bound HIGHVAL.
3143 if TYPE==NULL_TREE, sizetype is used. */
3146 build_range_type (type, lowval, highval)
3147 tree type, lowval, highval;
3149 register tree itype = make_node (INTEGER_TYPE);
3150 TREE_TYPE (itype) = type;
3151 if (type == NULL_TREE)
3153 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
3154 TYPE_MIN_VALUE (itype) = convert (type, lowval);
3155 TYPE_MAX_VALUE (itype) = convert (type, highval);
3156 TYPE_MODE (itype) = TYPE_MODE (type);
3157 TYPE_SIZE (itype) = TYPE_SIZE (type);
3158 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
3159 if ((TREE_CODE (lowval) == INTEGER_CST)
3160 && (TREE_CODE (highval) == INTEGER_CST))
3162 HOST_WIDE_INT highint = TREE_INT_CST_LOW (highval);
3163 HOST_WIDE_INT lowint = TREE_INT_CST_LOW (lowval);
3164 int maxint = (int) (highint - lowint);
3165 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
3171 /* Just like build_index_type, but takes lowval and highval instead
3172 of just highval (maxval). */
3175 build_index_2_type (lowval,highval)
3176 tree lowval, highval;
3178 return build_range_type (NULL_TREE, lowval, highval);
3181 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
3182 Needed because when index types are not hashed, equal index types
3183 built at different times appear distinct, even though structurally,
3187 index_type_equal (itype1, itype2)
3188 tree itype1, itype2;
3190 if (TREE_CODE (itype1) != TREE_CODE (itype2))
3192 if (TREE_CODE (itype1) == INTEGER_TYPE)
3194 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
3195 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
3196 || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2))
3197 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
3199 if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2))
3200 && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2)))
3206 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
3207 and number of elements specified by the range of values of INDEX_TYPE.
3208 If such a type has already been constructed, reuse it. */
3211 build_array_type (elt_type, index_type)
3212 tree elt_type, index_type;
3217 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
3219 error ("arrays of functions are not meaningful");
3220 elt_type = integer_type_node;
3223 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
3224 build_pointer_type (elt_type);
3226 /* Allocate the array after the pointer type,
3227 in case we free it in type_hash_canon. */
3228 t = make_node (ARRAY_TYPE);
3229 TREE_TYPE (t) = elt_type;
3230 TYPE_DOMAIN (t) = index_type;
3232 if (index_type == 0)
3237 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
3238 t = type_hash_canon (hashcode, t);
3240 #if 0 /* This led to crashes, because it could put a temporary node
3241 on the TYPE_NEXT_VARIANT chain of a permanent one. */
3242 /* The main variant of an array type should always
3243 be an array whose element type is the main variant. */
3244 if (elt_type != TYPE_MAIN_VARIANT (elt_type))
3245 change_main_variant (t, build_array_type (TYPE_MAIN_VARIANT (elt_type),
3249 if (TYPE_SIZE (t) == 0)
3254 /* Construct, lay out and return
3255 the type of functions returning type VALUE_TYPE
3256 given arguments of types ARG_TYPES.
3257 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
3258 are data type nodes for the arguments of the function.
3259 If such a type has already been constructed, reuse it. */
3262 build_function_type (value_type, arg_types)
3263 tree value_type, arg_types;
3268 if (TREE_CODE (value_type) == FUNCTION_TYPE)
3270 error ("function return type cannot be function");
3271 value_type = integer_type_node;
3274 /* Make a node of the sort we want. */
3275 t = make_node (FUNCTION_TYPE);
3276 TREE_TYPE (t) = value_type;
3277 TYPE_ARG_TYPES (t) = arg_types;
3279 /* If we already have such a type, use the old one and free this one. */
3280 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
3281 t = type_hash_canon (hashcode, t);
3283 if (TYPE_SIZE (t) == 0)
3288 /* Build the node for the type of references-to-TO_TYPE. */
3291 build_reference_type (to_type)
3294 register tree t = TYPE_REFERENCE_TO (to_type);
3295 register struct obstack *ambient_obstack = current_obstack;
3296 register struct obstack *ambient_saveable_obstack = saveable_obstack;
3298 /* First, if we already have a type for pointers to TO_TYPE, use it. */
3303 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
3304 if (TREE_PERMANENT (to_type))
3306 current_obstack = &permanent_obstack;
3307 saveable_obstack = &permanent_obstack;
3310 t = make_node (REFERENCE_TYPE);
3311 TREE_TYPE (t) = to_type;
3313 /* Record this type as the pointer to TO_TYPE. */
3314 TYPE_REFERENCE_TO (to_type) = t;
3318 current_obstack = ambient_obstack;
3319 saveable_obstack = ambient_saveable_obstack;
3323 /* Construct, lay out and return the type of methods belonging to class
3324 BASETYPE and whose arguments and values are described by TYPE.
3325 If that type exists already, reuse it.
3326 TYPE must be a FUNCTION_TYPE node. */
3329 build_method_type (basetype, type)
3330 tree basetype, type;
3335 /* Make a node of the sort we want. */
3336 t = make_node (METHOD_TYPE);
3338 if (TREE_CODE (type) != FUNCTION_TYPE)
3341 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
3342 TREE_TYPE (t) = TREE_TYPE (type);
3344 /* The actual arglist for this function includes a "hidden" argument
3345 which is "this". Put it into the list of argument types. */
3348 = tree_cons (NULL_TREE,
3349 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
3351 /* If we already have such a type, use the old one and free this one. */
3352 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
3353 t = type_hash_canon (hashcode, t);
3355 if (TYPE_SIZE (t) == 0)
3361 /* Construct, lay out and return the type of offsets to a value
3362 of type TYPE, within an object of type BASETYPE.
3363 If a suitable offset type exists already, reuse it. */
3366 build_offset_type (basetype, type)
3367 tree basetype, type;
3372 /* Make a node of the sort we want. */
3373 t = make_node (OFFSET_TYPE);
3375 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
3376 TREE_TYPE (t) = type;
3378 /* If we already have such a type, use the old one and free this one. */
3379 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
3380 t = type_hash_canon (hashcode, t);
3382 if (TYPE_SIZE (t) == 0)
3388 /* Create a complex type whose components are COMPONENT_TYPE. */
3391 build_complex_type (component_type)
3392 tree component_type;
3397 /* Make a node of the sort we want. */
3398 t = make_node (COMPLEX_TYPE);
3400 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
3401 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
3402 TYPE_READONLY (t) = TYPE_READONLY (component_type);
3404 /* If we already have such a type, use the old one and free this one. */
3405 hashcode = TYPE_HASH (component_type);
3406 t = type_hash_canon (hashcode, t);
3408 if (TYPE_SIZE (t) == 0)
3414 /* Return OP, stripped of any conversions to wider types as much as is safe.
3415 Converting the value back to OP's type makes a value equivalent to OP.
3417 If FOR_TYPE is nonzero, we return a value which, if converted to
3418 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
3420 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
3421 narrowest type that can hold the value, even if they don't exactly fit.
3422 Otherwise, bit-field references are changed to a narrower type
3423 only if they can be fetched directly from memory in that type.
3425 OP must have integer, real or enumeral type. Pointers are not allowed!
3427 There are some cases where the obvious value we could return
3428 would regenerate to OP if converted to OP's type,
3429 but would not extend like OP to wider types.
3430 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
3431 For example, if OP is (unsigned short)(signed char)-1,
3432 we avoid returning (signed char)-1 if FOR_TYPE is int,
3433 even though extending that to an unsigned short would regenerate OP,
3434 since the result of extending (signed char)-1 to (int)
3435 is different from (int) OP. */
3438 get_unwidened (op, for_type)
3442 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
3443 /* TYPE_PRECISION is safe in place of type_precision since
3444 pointer types are not allowed. */
3445 register tree type = TREE_TYPE (op);
3446 register unsigned final_prec
3447 = TYPE_PRECISION (for_type != 0 ? for_type : type);
3449 = (for_type != 0 && for_type != type
3450 && final_prec > TYPE_PRECISION (type)
3451 && TREE_UNSIGNED (type));
3452 register tree win = op;
3454 while (TREE_CODE (op) == NOP_EXPR)
3456 register int bitschange
3457 = TYPE_PRECISION (TREE_TYPE (op))
3458 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3460 /* Truncations are many-one so cannot be removed.
3461 Unless we are later going to truncate down even farther. */
3463 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
3466 /* See what's inside this conversion. If we decide to strip it,
3468 op = TREE_OPERAND (op, 0);
3470 /* If we have not stripped any zero-extensions (uns is 0),
3471 we can strip any kind of extension.
3472 If we have previously stripped a zero-extension,
3473 only zero-extensions can safely be stripped.
3474 Any extension can be stripped if the bits it would produce
3475 are all going to be discarded later by truncating to FOR_TYPE. */
3479 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
3481 /* TREE_UNSIGNED says whether this is a zero-extension.
3482 Let's avoid computing it if it does not affect WIN
3483 and if UNS will not be needed again. */
3484 if ((uns || TREE_CODE (op) == NOP_EXPR)
3485 && TREE_UNSIGNED (TREE_TYPE (op)))
3493 if (TREE_CODE (op) == COMPONENT_REF
3494 /* Since type_for_size always gives an integer type. */
3495 && TREE_CODE (type) != REAL_TYPE)
3497 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3498 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
3500 /* We can get this structure field in the narrowest type it fits in.
3501 If FOR_TYPE is 0, do this only for a field that matches the
3502 narrower type exactly and is aligned for it
3503 The resulting extension to its nominal type (a fullword type)
3504 must fit the same conditions as for other extensions. */
3506 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3507 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
3508 && (! uns || final_prec <= innerprec
3509 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3512 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3513 TREE_OPERAND (op, 1));
3514 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3515 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3516 TREE_RAISES (win) = TREE_RAISES (op);
3522 /* Return OP or a simpler expression for a narrower value
3523 which can be sign-extended or zero-extended to give back OP.
3524 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
3525 or 0 if the value should be sign-extended. */
3528 get_narrower (op, unsignedp_ptr)
3532 register int uns = 0;
3534 register tree win = op;
3536 while (TREE_CODE (op) == NOP_EXPR)
3538 register int bitschange
3539 = TYPE_PRECISION (TREE_TYPE (op))
3540 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3542 /* Truncations are many-one so cannot be removed. */
3546 /* See what's inside this conversion. If we decide to strip it,
3548 op = TREE_OPERAND (op, 0);
3552 /* An extension: the outermost one can be stripped,
3553 but remember whether it is zero or sign extension. */
3555 uns = TREE_UNSIGNED (TREE_TYPE (op));
3556 /* Otherwise, if a sign extension has been stripped,
3557 only sign extensions can now be stripped;
3558 if a zero extension has been stripped, only zero-extensions. */
3559 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
3563 else /* bitschange == 0 */
3565 /* A change in nominal type can always be stripped, but we must
3566 preserve the unsignedness. */
3568 uns = TREE_UNSIGNED (TREE_TYPE (op));
3575 if (TREE_CODE (op) == COMPONENT_REF
3576 /* Since type_for_size always gives an integer type. */
3577 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
3579 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3580 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
3582 /* We can get this structure field in a narrower type that fits it,
3583 but the resulting extension to its nominal type (a fullword type)
3584 must satisfy the same conditions as for other extensions.
3586 Do this only for fields that are aligned (not bit-fields),
3587 because when bit-field insns will be used there is no
3588 advantage in doing this. */
3590 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3591 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
3592 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3596 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
3597 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3598 TREE_OPERAND (op, 1));
3599 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3600 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3601 TREE_RAISES (win) = TREE_RAISES (op);
3604 *unsignedp_ptr = uns;
3608 /* Return the precision of a type, for arithmetic purposes.
3609 Supports all types on which arithmetic is possible
3610 (including pointer types).
3611 It's not clear yet what will be right for complex types. */
3614 type_precision (type)
3617 return ((TREE_CODE (type) == INTEGER_TYPE
3618 || TREE_CODE (type) == ENUMERAL_TYPE
3619 || TREE_CODE (type) == REAL_TYPE)
3620 ? TYPE_PRECISION (type) : POINTER_SIZE);
3623 /* Nonzero if integer constant C has a value that is permissible
3624 for type TYPE (an INTEGER_TYPE). */
3627 int_fits_type_p (c, type)
3630 if (TREE_UNSIGNED (type))
3631 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
3632 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
3633 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
3634 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type))));
3636 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
3637 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
3638 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
3639 && INT_CST_LT (c, TYPE_MIN_VALUE (type))));
3642 /* Return the innermost context enclosing DECL that is
3643 a FUNCTION_DECL, or zero if none. */
3646 decl_function_context (decl)
3651 if (TREE_CODE (decl) == ERROR_MARK)
3654 if (TREE_CODE (decl) == SAVE_EXPR)
3655 context = SAVE_EXPR_CONTEXT (decl);
3657 context = DECL_CONTEXT (decl);
3659 while (context && TREE_CODE (context) != FUNCTION_DECL)
3661 if (TREE_CODE (context) == RECORD_TYPE
3662 || TREE_CODE (context) == UNION_TYPE)
3663 context = TYPE_CONTEXT (context);
3664 else if (TREE_CODE (context) == TYPE_DECL)
3665 context = DECL_CONTEXT (context);
3666 else if (TREE_CODE (context) == BLOCK)
3667 context = BLOCK_SUPERCONTEXT (context);
3669 /* Unhandled CONTEXT !? */
3676 /* Return the innermost context enclosing DECL that is
3677 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
3678 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
3681 decl_type_context (decl)
3684 tree context = DECL_CONTEXT (decl);
3688 if (TREE_CODE (context) == RECORD_TYPE
3689 || TREE_CODE (context) == UNION_TYPE
3690 || TREE_CODE (context) == QUAL_UNION_TYPE)
3692 if (TREE_CODE (context) == TYPE_DECL
3693 || TREE_CODE (context) == FUNCTION_DECL)
3694 context = DECL_CONTEXT (context);
3695 else if (TREE_CODE (context) == BLOCK)
3696 context = BLOCK_SUPERCONTEXT (context);
3698 /* Unhandled CONTEXT!? */
3705 print_obstack_statistics (str, o)
3709 struct _obstack_chunk *chunk = o->chunk;
3716 n_alloc += chunk->limit - &chunk->contents[0];
3717 chunk = chunk->prev;
3719 fprintf (stderr, "obstack %s: %d bytes, %d chunks\n",
3720 str, n_alloc, n_chunks);
3723 dump_tree_statistics ()
3726 int total_nodes, total_bytes;
3728 fprintf (stderr, "\n??? tree nodes created\n\n");
3729 #ifdef GATHER_STATISTICS
3730 fprintf (stderr, "Kind Nodes Bytes\n");
3731 fprintf (stderr, "-------------------------------------\n");
3732 total_nodes = total_bytes = 0;
3733 for (i = 0; i < (int) all_kinds; i++)
3735 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
3736 tree_node_counts[i], tree_node_sizes[i]);
3737 total_nodes += tree_node_counts[i];
3738 total_bytes += tree_node_sizes[i];
3740 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
3741 fprintf (stderr, "-------------------------------------\n");
3742 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
3743 fprintf (stderr, "-------------------------------------\n");
3745 fprintf (stderr, "(No per-node statistics)\n");
3747 print_lang_statistics ();
3750 #define FILE_FUNCTION_PREFIX_LEN 9
3752 #ifndef NO_DOLLAR_IN_LABEL
3753 #define FILE_FUNCTION_FORMAT "_GLOBAL_$D$%s"
3754 #else /* NO_DOLLAR_IN_LABEL */
3755 #ifndef NO_DOT_IN_LABEL
3756 #define FILE_FUNCTION_FORMAT "_GLOBAL_.D.%s"
3757 #else /* NO_DOT_IN_LABEL */
3758 #define FILE_FUNCTION_FORMAT "_GLOBAL__D_%s"
3759 #endif /* NO_DOT_IN_LABEL */
3760 #endif /* NO_DOLLAR_IN_LABEL */
3762 extern char * first_global_object_name;
3764 /* If KIND=='I', return a suitable global initializer (constructor) name.
3765 If KIND=='D', return a suitable global clean-up (destructor) name. */
3768 get_file_function_name (kind)
3774 if (first_global_object_name)
3775 p = first_global_object_name;
3776 else if (main_input_filename)
3777 p = main_input_filename;
3781 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p));
3783 /* Set up the name of the file-level functions we may need. */
3784 /* Use a global object (which is already required to be unique over
3785 the program) rather than the file name (which imposes extra
3786 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
3787 sprintf (buf, FILE_FUNCTION_FORMAT, p);
3789 /* Don't need to pull wierd characters out of global names. */
3790 if (p != first_global_object_name)
3792 for (p = buf+11; *p; p++)
3793 if (! ((*p >= '0' && *p <= '9')
3794 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
3795 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
3799 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
3802 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
3805 || (*p >= 'A' && *p <= 'Z')
3806 || (*p >= 'a' && *p <= 'z')))
3810 buf[FILE_FUNCTION_PREFIX_LEN] = kind;
3812 return get_identifier (buf);