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. */
48 #define obstack_chunk_alloc xmalloc
49 #define obstack_chunk_free free
51 /* Tree nodes of permanent duration are allocated in this obstack.
52 They are the identifier nodes, and everything outside of
53 the bodies and parameters of function definitions. */
55 struct obstack permanent_obstack;
57 /* The initial RTL, and all ..._TYPE nodes, in a function
58 are allocated in this obstack. Usually they are freed at the
59 end of the function, but if the function is inline they are saved.
60 For top-level functions, this is maybepermanent_obstack.
61 Separate obstacks are made for nested functions. */
63 struct obstack *function_maybepermanent_obstack;
65 /* This is the function_maybepermanent_obstack for top-level functions. */
67 struct obstack maybepermanent_obstack;
69 /* The contents of the current function definition are allocated
70 in this obstack, and all are freed at the end of the function.
71 For top-level functions, this is temporary_obstack.
72 Separate obstacks are made for nested functions. */
74 struct obstack *function_obstack;
76 /* This is used for reading initializers of global variables. */
78 struct obstack temporary_obstack;
80 /* The tree nodes of an expression are allocated
81 in this obstack, and all are freed at the end of the expression. */
83 struct obstack momentary_obstack;
85 /* The tree nodes of a declarator are allocated
86 in this obstack, and all are freed when the declarator
89 static struct obstack temp_decl_obstack;
91 /* This points at either permanent_obstack
92 or the current function_maybepermanent_obstack. */
94 struct obstack *saveable_obstack;
96 /* This is same as saveable_obstack during parse and expansion phase;
97 it points to the current function's obstack during optimization.
98 This is the obstack to be used for creating rtl objects. */
100 struct obstack *rtl_obstack;
102 /* This points at either permanent_obstack or the current function_obstack. */
104 struct obstack *current_obstack;
106 /* This points at either permanent_obstack or the current function_obstack
107 or momentary_obstack. */
109 struct obstack *expression_obstack;
111 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
115 struct obstack_stack *next;
116 struct obstack *current;
117 struct obstack *saveable;
118 struct obstack *expression;
122 struct obstack_stack *obstack_stack;
124 /* Obstack for allocating struct obstack_stack entries. */
126 static struct obstack obstack_stack_obstack;
128 /* Addresses of first objects in some obstacks.
129 This is for freeing their entire contents. */
130 char *maybepermanent_firstobj;
131 char *temporary_firstobj;
132 char *momentary_firstobj;
133 char *temp_decl_firstobj;
135 /* This is used to preserve objects (mainly array initializers) that need to
136 live until the end of the current function, but no further. */
137 char *momentary_function_firstobj;
139 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
141 int all_types_permanent;
143 /* Stack of places to restore the momentary obstack back to. */
145 struct momentary_level
147 /* Pointer back to previous such level. */
148 struct momentary_level *prev;
149 /* First object allocated within this level. */
151 /* Value of expression_obstack saved at entry to this level. */
152 struct obstack *obstack;
155 struct momentary_level *momentary_stack;
157 /* Table indexed by tree code giving a string containing a character
158 classifying the tree code. Possibilities are
159 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
161 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
163 char *standard_tree_code_type[] = {
168 /* Table indexed by tree code giving number of expression
169 operands beyond the fixed part of the node structure.
170 Not used for types or decls. */
172 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
174 int standard_tree_code_length[] = {
179 /* Names of tree components.
180 Used for printing out the tree and error messages. */
181 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
183 char *standard_tree_code_name[] = {
188 /* Table indexed by tree code giving a string containing a character
189 classifying the tree code. Possibilities are
190 t, d, s, c, r, e, <, 1 and 2. See tree.def for details. */
192 char **tree_code_type;
194 /* Table indexed by tree code giving number of expression
195 operands beyond the fixed part of the node structure.
196 Not used for types or decls. */
198 int *tree_code_length;
200 /* Table indexed by tree code giving name of tree code, as a string. */
202 char **tree_code_name;
204 /* Statistics-gathering stuff. */
225 int tree_node_counts[(int)all_kinds];
226 int tree_node_sizes[(int)all_kinds];
227 int id_string_size = 0;
229 char *tree_node_kind_names[] = {
247 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
249 #define MAX_HASH_TABLE 1009
250 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
252 /* 0 while creating built-in identifiers. */
253 static int do_identifier_warnings;
255 /* Unique id for next decl created. */
256 static int next_decl_uid;
257 /* Unique id for next type created. */
258 static int next_type_uid = 1;
260 extern char *mode_name[];
262 void gcc_obstack_init ();
263 static tree stabilize_reference_1 ();
265 /* Init the principal obstacks. */
270 gcc_obstack_init (&obstack_stack_obstack);
271 gcc_obstack_init (&permanent_obstack);
273 gcc_obstack_init (&temporary_obstack);
274 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
275 gcc_obstack_init (&momentary_obstack);
276 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
277 momentary_function_firstobj = momentary_firstobj;
278 gcc_obstack_init (&maybepermanent_obstack);
279 maybepermanent_firstobj
280 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
281 gcc_obstack_init (&temp_decl_obstack);
282 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
284 function_obstack = &temporary_obstack;
285 function_maybepermanent_obstack = &maybepermanent_obstack;
286 current_obstack = &permanent_obstack;
287 expression_obstack = &permanent_obstack;
288 rtl_obstack = saveable_obstack = &permanent_obstack;
290 /* Init the hash table of identifiers. */
291 bzero (hash_table, sizeof hash_table);
295 gcc_obstack_init (obstack)
296 struct obstack *obstack;
298 /* Let particular systems override the size of a chunk. */
299 #ifndef OBSTACK_CHUNK_SIZE
300 #define OBSTACK_CHUNK_SIZE 0
302 /* Let them override the alloc and free routines too. */
303 #ifndef OBSTACK_CHUNK_ALLOC
304 #define OBSTACK_CHUNK_ALLOC xmalloc
306 #ifndef OBSTACK_CHUNK_FREE
307 #define OBSTACK_CHUNK_FREE free
309 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
310 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
311 (void (*) ()) OBSTACK_CHUNK_FREE);
314 /* Save all variables describing the current status into the structure *P.
315 This is used before starting a nested function. */
321 p->all_types_permanent = all_types_permanent;
322 p->momentary_stack = momentary_stack;
323 p->maybepermanent_firstobj = maybepermanent_firstobj;
324 p->momentary_firstobj = momentary_firstobj;
325 p->momentary_function_firstobj = momentary_function_firstobj;
326 p->function_obstack = function_obstack;
327 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
328 p->current_obstack = current_obstack;
329 p->expression_obstack = expression_obstack;
330 p->saveable_obstack = saveable_obstack;
331 p->rtl_obstack = rtl_obstack;
333 /* Objects that need to be saved in this function can be in the nonsaved
334 obstack of the enclosing function since they can't possibly be needed
335 once it has returned. */
336 function_maybepermanent_obstack = function_obstack;
338 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
339 gcc_obstack_init (function_obstack);
341 current_obstack = &permanent_obstack;
342 expression_obstack = &permanent_obstack;
343 rtl_obstack = saveable_obstack = &permanent_obstack;
345 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
346 momentary_function_firstobj = momentary_firstobj;
347 maybepermanent_firstobj
348 = (char *) obstack_finish (function_maybepermanent_obstack);
351 /* Restore all variables describing the current status from the structure *P.
352 This is used after a nested function. */
355 restore_tree_status (p)
358 all_types_permanent = p->all_types_permanent;
359 momentary_stack = p->momentary_stack;
361 obstack_free (&momentary_obstack, momentary_function_firstobj);
363 /* Free saveable storage used by the function just compiled and not
366 CAUTION: This is in function_obstack of the containing function. So
367 we must be sure that we never allocate from that obstack during
368 the compilation of a nested function if we expect it to survive past the
369 nested function's end. */
370 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
372 obstack_free (function_obstack, 0);
373 free (function_obstack);
375 momentary_firstobj = p->momentary_firstobj;
376 momentary_function_firstobj = p->momentary_function_firstobj;
377 maybepermanent_firstobj = p->maybepermanent_firstobj;
378 function_obstack = p->function_obstack;
379 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
380 current_obstack = p->current_obstack;
381 expression_obstack = p->expression_obstack;
382 saveable_obstack = p->saveable_obstack;
383 rtl_obstack = p->rtl_obstack;
386 /* Start allocating on the temporary (per function) obstack.
387 This is done in start_function before parsing the function body,
388 and before each initialization at top level, and to go back
389 to temporary allocation after doing permanent_allocation. */
392 temporary_allocation ()
394 /* Note that function_obstack at top level points to temporary_obstack.
395 But within a nested function context, it is a separate obstack. */
396 current_obstack = function_obstack;
397 expression_obstack = function_obstack;
398 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
402 /* Start allocating on the permanent obstack but don't
403 free the temporary data. After calling this, call
404 `permanent_allocation' to fully resume permanent allocation status. */
407 end_temporary_allocation ()
409 current_obstack = &permanent_obstack;
410 expression_obstack = &permanent_obstack;
411 rtl_obstack = saveable_obstack = &permanent_obstack;
414 /* Resume allocating on the temporary obstack, undoing
415 effects of `end_temporary_allocation'. */
418 resume_temporary_allocation ()
420 current_obstack = function_obstack;
421 expression_obstack = function_obstack;
422 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
425 /* While doing temporary allocation, switch to allocating in such a
426 way as to save all nodes if the function is inlined. Call
427 resume_temporary_allocation to go back to ordinary temporary
431 saveable_allocation ()
433 /* Note that function_obstack at top level points to temporary_obstack.
434 But within a nested function context, it is a separate obstack. */
435 expression_obstack = current_obstack = saveable_obstack;
438 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
439 recording the previously current obstacks on a stack.
440 This does not free any storage in any obstack. */
443 push_obstacks (current, saveable)
444 struct obstack *current, *saveable;
446 struct obstack_stack *p
447 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
448 (sizeof (struct obstack_stack)));
450 p->current = current_obstack;
451 p->saveable = saveable_obstack;
452 p->expression = expression_obstack;
453 p->rtl = rtl_obstack;
454 p->next = obstack_stack;
457 current_obstack = current;
458 expression_obstack = current;
459 rtl_obstack = saveable_obstack = saveable;
462 /* Save the current set of obstacks, but don't change them. */
465 push_obstacks_nochange ()
467 struct obstack_stack *p
468 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
469 (sizeof (struct obstack_stack)));
471 p->current = current_obstack;
472 p->saveable = saveable_obstack;
473 p->expression = expression_obstack;
474 p->rtl = rtl_obstack;
475 p->next = obstack_stack;
479 /* Pop the obstack selection stack. */
484 struct obstack_stack *p = obstack_stack;
485 obstack_stack = p->next;
487 current_obstack = p->current;
488 saveable_obstack = p->saveable;
489 expression_obstack = p->expression;
490 rtl_obstack = p->rtl;
492 obstack_free (&obstack_stack_obstack, p);
495 /* Nonzero if temporary allocation is currently in effect.
496 Zero if currently doing permanent allocation. */
499 allocation_temporary_p ()
501 return current_obstack != &permanent_obstack;
504 /* Go back to allocating on the permanent obstack
505 and free everything in the temporary obstack.
507 FUNCTION_END is true only if we have just finished compiling a function.
508 In that case, we also free preserved initial values on the momentary
512 permanent_allocation (function_end)
515 /* Free up previous temporary obstack data */
516 obstack_free (&temporary_obstack, temporary_firstobj);
518 obstack_free (&momentary_obstack, momentary_function_firstobj);
520 obstack_free (&momentary_obstack, momentary_firstobj);
521 obstack_free (&maybepermanent_obstack, maybepermanent_firstobj);
522 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
524 current_obstack = &permanent_obstack;
525 expression_obstack = &permanent_obstack;
526 rtl_obstack = saveable_obstack = &permanent_obstack;
529 /* Save permanently everything on the maybepermanent_obstack. */
534 maybepermanent_firstobj
535 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
539 preserve_initializer ()
541 struct momentary_level *tem;
545 = (char *) obstack_alloc (&temporary_obstack, 0);
546 maybepermanent_firstobj
547 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
549 old_momentary = momentary_firstobj;
551 = (char *) obstack_alloc (&momentary_obstack, 0);
552 if (momentary_firstobj != old_momentary)
553 for (tem = momentary_stack; tem; tem = tem->prev)
554 tem->base = momentary_firstobj;
557 /* Start allocating new rtl in current_obstack.
558 Use resume_temporary_allocation
559 to go back to allocating rtl in saveable_obstack. */
562 rtl_in_current_obstack ()
564 rtl_obstack = current_obstack;
567 /* Start allocating rtl from saveable_obstack. Intended to be used after
568 a call to push_obstacks_nochange. */
571 rtl_in_saveable_obstack ()
573 rtl_obstack = saveable_obstack;
576 /* Allocate SIZE bytes in the current obstack
577 and return a pointer to them.
578 In practice the current obstack is always the temporary one. */
584 return (char *) obstack_alloc (current_obstack, size);
587 /* Free the object PTR in the current obstack
588 as well as everything allocated since PTR.
589 In practice the current obstack is always the temporary one. */
595 obstack_free (current_obstack, ptr);
598 /* Allocate SIZE bytes in the permanent obstack
599 and return a pointer to them. */
605 return (char *) obstack_alloc (&permanent_obstack, size);
608 /* Allocate NELEM items of SIZE bytes in the permanent obstack
609 and return a pointer to them. The storage is cleared before
610 returning the value. */
613 perm_calloc (nelem, size)
617 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
618 bzero (rval, nelem * size);
622 /* Allocate SIZE bytes in the saveable obstack
623 and return a pointer to them. */
629 return (char *) obstack_alloc (saveable_obstack, size);
632 /* Print out which obstack an object is in. */
635 print_obstack_name (object, file, prefix)
640 struct obstack *obstack = NULL;
641 char *obstack_name = NULL;
644 for (p = outer_function_chain; p; p = p->next)
646 if (_obstack_allocated_p (p->function_obstack, object))
648 obstack = p->function_obstack;
649 obstack_name = "containing function obstack";
651 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
653 obstack = p->function_maybepermanent_obstack;
654 obstack_name = "containing function maybepermanent obstack";
658 if (_obstack_allocated_p (&obstack_stack_obstack, object))
660 obstack = &obstack_stack_obstack;
661 obstack_name = "obstack_stack_obstack";
663 else if (_obstack_allocated_p (function_obstack, object))
665 obstack = function_obstack;
666 obstack_name = "function obstack";
668 else if (_obstack_allocated_p (&permanent_obstack, object))
670 obstack = &permanent_obstack;
671 obstack_name = "permanent_obstack";
673 else if (_obstack_allocated_p (&momentary_obstack, object))
675 obstack = &momentary_obstack;
676 obstack_name = "momentary_obstack";
678 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
680 obstack = function_maybepermanent_obstack;
681 obstack_name = "function maybepermanent obstack";
683 else if (_obstack_allocated_p (&temp_decl_obstack, object))
685 obstack = &temp_decl_obstack;
686 obstack_name = "temp_decl_obstack";
689 /* Check to see if the object is in the free area of the obstack. */
692 if (object >= obstack->next_free
693 && object < obstack->chunk_limit)
694 fprintf (file, "%s in free portion of obstack %s",
695 prefix, obstack_name);
697 fprintf (file, "%s allocated from %s", prefix, obstack_name);
700 fprintf (file, "%s not allocated from any obstack", prefix);
704 debug_obstack (object)
707 print_obstack_name (object, stderr, "object");
708 fprintf (stderr, ".\n");
711 /* Return 1 if OBJ is in the permanent obstack.
712 This is slow, and should be used only for debugging.
713 Use TREE_PERMANENT for other purposes. */
716 object_permanent_p (obj)
719 return _obstack_allocated_p (&permanent_obstack, obj);
722 /* Start a level of momentary allocation.
723 In C, each compound statement has its own level
724 and that level is freed at the end of each statement.
725 All expression nodes are allocated in the momentary allocation level. */
730 struct momentary_level *tem
731 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
732 sizeof (struct momentary_level));
733 tem->prev = momentary_stack;
734 tem->base = (char *) obstack_base (&momentary_obstack);
735 tem->obstack = expression_obstack;
736 momentary_stack = tem;
737 expression_obstack = &momentary_obstack;
740 /* Free all the storage in the current momentary-allocation level.
741 In C, this happens at the end of each statement. */
746 obstack_free (&momentary_obstack, momentary_stack->base);
749 /* Discard a level of momentary allocation.
750 In C, this happens at the end of each compound statement.
751 Restore the status of expression node allocation
752 that was in effect before this level was created. */
757 struct momentary_level *tem = momentary_stack;
758 momentary_stack = tem->prev;
759 expression_obstack = tem->obstack;
760 /* We can't free TEM from the momentary_obstack, because there might
761 be objects above it which have been saved. We can free back to the
762 stack of the level we are popping off though. */
763 obstack_free (&momentary_obstack, tem->base);
766 /* Pop back to the previous level of momentary allocation,
767 but don't free any momentary data just yet. */
770 pop_momentary_nofree ()
772 struct momentary_level *tem = momentary_stack;
773 momentary_stack = tem->prev;
774 expression_obstack = tem->obstack;
777 /* Call when starting to parse a declaration:
778 make expressions in the declaration last the length of the function.
779 Returns an argument that should be passed to resume_momentary later. */
784 register int tem = expression_obstack == &momentary_obstack;
785 expression_obstack = saveable_obstack;
789 /* Call when finished parsing a declaration:
790 restore the treatment of node-allocation that was
791 in effect before the suspension.
792 YES should be the value previously returned by suspend_momentary. */
795 resume_momentary (yes)
799 expression_obstack = &momentary_obstack;
802 /* Init the tables indexed by tree code.
803 Note that languages can add to these tables to define their own codes. */
808 tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type));
809 tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length));
810 tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name));
811 bcopy (standard_tree_code_type, tree_code_type,
812 sizeof (standard_tree_code_type));
813 bcopy (standard_tree_code_length, tree_code_length,
814 sizeof (standard_tree_code_length));
815 bcopy (standard_tree_code_name, tree_code_name,
816 sizeof (standard_tree_code_name));
819 /* Return a newly allocated node of code CODE.
820 Initialize the node's unique id and its TREE_PERMANENT flag.
821 For decl and type nodes, some other fields are initialized.
822 The rest of the node is initialized to zero.
824 Achoo! I got a code in the node. */
831 register int type = TREE_CODE_CLASS (code);
833 register struct obstack *obstack = current_obstack;
835 register tree_node_kind kind;
839 case 'd': /* A decl node */
840 #ifdef GATHER_STATISTICS
843 length = sizeof (struct tree_decl);
844 /* All decls in an inline function need to be saved. */
845 if (obstack != &permanent_obstack)
846 obstack = saveable_obstack;
848 /* PARM_DECLs go on the context of the parent. If this is a nested
849 function, then we must allocate the PARM_DECL on the parent's
850 obstack, so that they will live to the end of the parent's
851 closing brace. This is neccesary in case we try to inline the
852 function into its parent.
854 PARM_DECLs of top-level functions do not have this problem. However,
855 we allocate them where we put the FUNCTION_DECL for languauges such as
856 Ada that need to consult some flags in the PARM_DECLs of the function
859 See comment in restore_tree_status for why we can't put this
860 in function_obstack. */
861 if (code == PARM_DECL && obstack != &permanent_obstack)
864 if (current_function_decl)
865 context = decl_function_context (current_function_decl);
869 = find_function_data (context)->function_maybepermanent_obstack;
873 case 't': /* a type node */
874 #ifdef GATHER_STATISTICS
877 length = sizeof (struct tree_type);
878 /* All data types are put where we can preserve them if nec. */
879 if (obstack != &permanent_obstack)
880 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
883 case 'b': /* a lexical block */
884 #ifdef GATHER_STATISTICS
887 length = sizeof (struct tree_block);
888 /* All BLOCK nodes are put where we can preserve them if nec. */
889 if (obstack != &permanent_obstack)
890 obstack = saveable_obstack;
893 case 's': /* an expression with side effects */
894 #ifdef GATHER_STATISTICS
898 case 'r': /* a reference */
899 #ifdef GATHER_STATISTICS
903 case 'e': /* an expression */
904 case '<': /* a comparison expression */
905 case '1': /* a unary arithmetic expression */
906 case '2': /* a binary arithmetic expression */
907 #ifdef GATHER_STATISTICS
911 obstack = expression_obstack;
912 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
913 if (code == BIND_EXPR && obstack != &permanent_obstack)
914 obstack = saveable_obstack;
915 length = sizeof (struct tree_exp)
916 + (tree_code_length[(int) code] - 1) * sizeof (char *);
919 case 'c': /* a constant */
920 #ifdef GATHER_STATISTICS
923 obstack = expression_obstack;
925 /* We can't use tree_code_length for INTEGER_CST, since the number of
926 words is machine-dependent due to varying length of HOST_WIDE_INT,
927 which might be wider than a pointer (e.g., long long). Similarly
928 for REAL_CST, since the number of words is machine-dependent due
929 to varying size and alignment of `double'. */
931 if (code == INTEGER_CST)
932 length = sizeof (struct tree_int_cst);
933 else if (code == REAL_CST)
934 length = sizeof (struct tree_real_cst);
936 length = sizeof (struct tree_common)
937 + tree_code_length[(int) code] * sizeof (char *);
940 case 'x': /* something random, like an identifier. */
941 #ifdef GATHER_STATISTICS
942 if (code == IDENTIFIER_NODE)
944 else if (code == OP_IDENTIFIER)
946 else if (code == TREE_VEC)
951 length = sizeof (struct tree_common)
952 + tree_code_length[(int) code] * sizeof (char *);
953 /* Identifier nodes are always permanent since they are
954 unique in a compiler run. */
955 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
962 t = (tree) obstack_alloc (obstack, length);
964 #ifdef GATHER_STATISTICS
965 tree_node_counts[(int)kind]++;
966 tree_node_sizes[(int)kind] += length;
969 /* Clear a word at a time. */
970 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
972 /* Clear any extra bytes. */
973 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
976 TREE_SET_CODE (t, code);
977 if (obstack == &permanent_obstack)
978 TREE_PERMANENT (t) = 1;
983 TREE_SIDE_EFFECTS (t) = 1;
984 TREE_TYPE (t) = void_type_node;
988 if (code != FUNCTION_DECL)
990 DECL_IN_SYSTEM_HEADER (t)
991 = in_system_header && (obstack == &permanent_obstack);
992 DECL_SOURCE_LINE (t) = lineno;
993 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
994 DECL_UID (t) = next_decl_uid++;
998 TYPE_UID (t) = next_type_uid++;
1000 TYPE_MAIN_VARIANT (t) = t;
1001 TYPE_OBSTACK (t) = obstack;
1005 TREE_CONSTANT (t) = 1;
1012 /* Return a new node with the same contents as NODE
1013 except that its TREE_CHAIN is zero and it has a fresh uid. */
1020 register enum tree_code code = TREE_CODE (node);
1021 register int length;
1024 switch (TREE_CODE_CLASS (code))
1026 case 'd': /* A decl node */
1027 length = sizeof (struct tree_decl);
1030 case 't': /* a type node */
1031 length = sizeof (struct tree_type);
1034 case 'b': /* a lexical block node */
1035 length = sizeof (struct tree_block);
1038 case 'r': /* a reference */
1039 case 'e': /* an expression */
1040 case 's': /* an expression with side effects */
1041 case '<': /* a comparison expression */
1042 case '1': /* a unary arithmetic expression */
1043 case '2': /* a binary arithmetic expression */
1044 length = sizeof (struct tree_exp)
1045 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1048 case 'c': /* a constant */
1049 /* We can't use tree_code_length for INTEGER_CST, since the number of
1050 words is machine-dependent due to varying length of HOST_WIDE_INT,
1051 which might be wider than a pointer (e.g., long long). Similarly
1052 for REAL_CST, since the number of words is machine-dependent due
1053 to varying size and alignment of `double'. */
1054 if (code == INTEGER_CST)
1056 length = sizeof (struct tree_int_cst);
1059 else if (code == REAL_CST)
1061 length = sizeof (struct tree_real_cst);
1065 case 'x': /* something random, like an identifier. */
1066 length = sizeof (struct tree_common)
1067 + tree_code_length[(int) code] * sizeof (char *);
1068 if (code == TREE_VEC)
1069 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1072 t = (tree) obstack_alloc (current_obstack, length);
1074 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1075 ((int *) t)[i] = ((int *) node)[i];
1076 /* Clear any extra bytes. */
1077 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1078 ((char *) t)[i] = ((char *) node)[i];
1082 if (TREE_CODE_CLASS (code) == 'd')
1083 DECL_UID (t) = next_decl_uid++;
1084 else if (TREE_CODE_CLASS (code) == 't')
1086 TYPE_UID (t) = next_type_uid++;
1087 TYPE_OBSTACK (t) = current_obstack;
1090 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1095 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1096 For example, this can copy a list made of TREE_LIST nodes. */
1103 register tree prev, next;
1108 head = prev = copy_node (list);
1109 next = TREE_CHAIN (list);
1112 TREE_CHAIN (prev) = copy_node (next);
1113 prev = TREE_CHAIN (prev);
1114 next = TREE_CHAIN (next);
1121 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1122 If an identifier with that name has previously been referred to,
1123 the same node is returned this time. */
1126 get_identifier (text)
1127 register char *text;
1132 register int len, hash_len;
1134 /* Compute length of text in len. */
1135 for (len = 0; text[len]; len++);
1137 /* Decide how much of that length to hash on */
1139 if (warn_id_clash && len > id_clash_len)
1140 hash_len = id_clash_len;
1142 /* Compute hash code */
1143 hi = hash_len * 613 + (unsigned)text[0];
1144 for (i = 1; i < hash_len; i += 2)
1145 hi = ((hi * 613) + (unsigned)(text[i]));
1147 hi &= (1 << HASHBITS) - 1;
1148 hi %= MAX_HASH_TABLE;
1150 /* Search table for identifier */
1151 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1152 if (IDENTIFIER_LENGTH (idp) == len
1153 && IDENTIFIER_POINTER (idp)[0] == text[0]
1154 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1155 return idp; /* <-- return if found */
1157 /* Not found; optionally warn about a similar identifier */
1158 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1159 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1160 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1162 warning ("`%s' and `%s' identical in first %d characters",
1163 IDENTIFIER_POINTER (idp), text, id_clash_len);
1167 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1168 abort (); /* set_identifier_size hasn't been called. */
1170 /* Not found, create one, add to chain */
1171 idp = make_node (IDENTIFIER_NODE);
1172 IDENTIFIER_LENGTH (idp) = len;
1173 #ifdef GATHER_STATISTICS
1174 id_string_size += len;
1177 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1179 TREE_CHAIN (idp) = hash_table[hi];
1180 hash_table[hi] = idp;
1181 return idp; /* <-- return if created */
1184 /* Enable warnings on similar identifiers (if requested).
1185 Done after the built-in identifiers are created. */
1188 start_identifier_warnings ()
1190 do_identifier_warnings = 1;
1193 /* Record the size of an identifier node for the language in use.
1194 SIZE is the total size in bytes.
1195 This is called by the language-specific files. This must be
1196 called before allocating any identifiers. */
1199 set_identifier_size (size)
1202 tree_code_length[(int) IDENTIFIER_NODE]
1203 = (size - sizeof (struct tree_common)) / sizeof (tree);
1206 /* Return a newly constructed INTEGER_CST node whose constant value
1207 is specified by the two ints LOW and HI.
1208 The TREE_TYPE is set to `int'.
1210 This function should be used via the `build_int_2' macro. */
1213 build_int_2_wide (low, hi)
1214 HOST_WIDE_INT low, hi;
1216 register tree t = make_node (INTEGER_CST);
1217 TREE_INT_CST_LOW (t) = low;
1218 TREE_INT_CST_HIGH (t) = hi;
1219 TREE_TYPE (t) = integer_type_node;
1223 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1226 build_real (type, d)
1233 /* Check for valid float value for this type on this target machine;
1234 if not, can print error message and store a valid value in D. */
1235 #ifdef CHECK_FLOAT_VALUE
1236 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1239 v = make_node (REAL_CST);
1240 TREE_TYPE (v) = type;
1241 TREE_REAL_CST (v) = d;
1242 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1246 /* Return a new REAL_CST node whose type is TYPE
1247 and whose value is the integer value of the INTEGER_CST node I. */
1249 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1252 real_value_from_int_cst (i)
1257 /* Some 386 compilers mishandle unsigned int to float conversions,
1258 so introduce a temporary variable E to avoid those bugs. */
1260 #ifdef REAL_ARITHMETIC
1261 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1262 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1264 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1265 #else /* not REAL_ARITHMETIC */
1266 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1268 d = (double) (~ TREE_INT_CST_HIGH (i));
1269 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1270 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1272 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1278 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1279 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1280 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1282 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1285 #endif /* not REAL_ARITHMETIC */
1289 /* This function can't be implemented if we can't do arithmetic
1290 on the float representation. */
1293 build_real_from_int_cst (type, i)
1298 int overflow = TREE_OVERFLOW (i);
1300 jmp_buf float_error;
1302 v = make_node (REAL_CST);
1303 TREE_TYPE (v) = type;
1305 if (setjmp (float_error))
1312 set_float_handler (float_error);
1314 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type), real_value_from_int_cst (i));
1316 /* Check for valid float value for this type on this target machine. */
1319 set_float_handler (NULL_PTR);
1321 #ifdef CHECK_FLOAT_VALUE
1322 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1325 TREE_REAL_CST (v) = d;
1326 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1330 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1332 /* Return a newly constructed STRING_CST node whose value is
1333 the LEN characters at STR.
1334 The TREE_TYPE is not initialized. */
1337 build_string (len, str)
1341 /* Put the string in saveable_obstack since it will be placed in the RTL
1342 for an "asm" statement and will also be kept around a while if
1343 deferring constant output in varasm.c. */
1345 register tree s = make_node (STRING_CST);
1346 TREE_STRING_LENGTH (s) = len;
1347 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1351 /* Return a newly constructed COMPLEX_CST node whose value is
1352 specified by the real and imaginary parts REAL and IMAG.
1353 Both REAL and IMAG should be constant nodes.
1354 The TREE_TYPE is not initialized. */
1357 build_complex (real, imag)
1360 register tree t = make_node (COMPLEX_CST);
1362 TREE_REALPART (t) = real;
1363 TREE_IMAGPART (t) = imag;
1364 TREE_TYPE (t) = build_complex_type (TREE_TYPE (real));
1365 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1366 TREE_CONSTANT_OVERFLOW (t)
1367 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1371 /* Build a newly constructed TREE_VEC node of length LEN. */
1377 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1378 register struct obstack *obstack = current_obstack;
1381 #ifdef GATHER_STATISTICS
1382 tree_node_counts[(int)vec_kind]++;
1383 tree_node_sizes[(int)vec_kind] += length;
1386 t = (tree) obstack_alloc (obstack, length);
1388 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1391 TREE_SET_CODE (t, TREE_VEC);
1392 TREE_VEC_LENGTH (t) = len;
1393 if (obstack == &permanent_obstack)
1394 TREE_PERMANENT (t) = 1;
1399 /* Return 1 if EXPR is the integer constant zero. */
1402 integer_zerop (expr)
1407 return (TREE_CODE (expr) == INTEGER_CST
1408 && TREE_INT_CST_LOW (expr) == 0
1409 && TREE_INT_CST_HIGH (expr) == 0);
1412 /* Return 1 if EXPR is the integer constant one. */
1420 return (TREE_CODE (expr) == INTEGER_CST
1421 && TREE_INT_CST_LOW (expr) == 1
1422 && TREE_INT_CST_HIGH (expr) == 0);
1425 /* Return 1 if EXPR is an integer containing all 1's
1426 in as much precision as it contains. */
1429 integer_all_onesp (expr)
1437 if (TREE_CODE (expr) != INTEGER_CST)
1440 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1442 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1444 prec = TYPE_PRECISION (TREE_TYPE (expr));
1445 if (prec >= HOST_BITS_PER_WIDE_INT)
1447 int high_value, shift_amount;
1449 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1451 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1452 /* Can not handle precisions greater than twice the host int size. */
1454 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1455 /* Shifting by the host word size is undefined according to the ANSI
1456 standard, so we must handle this as a special case. */
1459 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1461 return TREE_INT_CST_LOW (expr) == -1
1462 && TREE_INT_CST_HIGH (expr) == high_value;
1465 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1468 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1472 integer_pow2p (expr)
1475 HOST_WIDE_INT high, low;
1479 if (TREE_CODE (expr) != INTEGER_CST)
1482 high = TREE_INT_CST_HIGH (expr);
1483 low = TREE_INT_CST_LOW (expr);
1485 if (high == 0 && low == 0)
1488 return ((high == 0 && (low & (low - 1)) == 0)
1489 || (low == 0 && (high & (high - 1)) == 0));
1492 /* Return 1 if EXPR is the real constant zero. */
1500 return (TREE_CODE (expr) == REAL_CST
1501 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0));
1504 /* Return 1 if EXPR is the real constant one. */
1512 return (TREE_CODE (expr) == REAL_CST
1513 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1));
1516 /* Return 1 if EXPR is the real constant two. */
1524 return (TREE_CODE (expr) == REAL_CST
1525 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2));
1528 /* Nonzero if EXP is a constant or a cast of a constant. */
1531 really_constant_p (exp)
1534 /* This is not quite the same as STRIP_NOPS. It does more. */
1535 while (TREE_CODE (exp) == NOP_EXPR
1536 || TREE_CODE (exp) == CONVERT_EXPR
1537 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1538 exp = TREE_OPERAND (exp, 0);
1539 return TREE_CONSTANT (exp);
1542 /* Return first list element whose TREE_VALUE is ELEM.
1543 Return 0 if ELEM is not it LIST. */
1546 value_member (elem, list)
1551 if (elem == TREE_VALUE (list))
1553 list = TREE_CHAIN (list);
1558 /* Return first list element whose TREE_PURPOSE is ELEM.
1559 Return 0 if ELEM is not it LIST. */
1562 purpose_member (elem, list)
1567 if (elem == TREE_PURPOSE (list))
1569 list = TREE_CHAIN (list);
1574 /* Return first list element whose BINFO_TYPE is ELEM.
1575 Return 0 if ELEM is not it LIST. */
1578 binfo_member (elem, list)
1583 if (elem == BINFO_TYPE (list))
1585 list = TREE_CHAIN (list);
1590 /* Return nonzero if ELEM is part of the chain CHAIN. */
1593 chain_member (elem, chain)
1600 chain = TREE_CHAIN (chain);
1606 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1607 We expect a null pointer to mark the end of the chain.
1608 This is the Lisp primitive `length'. */
1615 register int len = 0;
1617 for (tail = t; tail; tail = TREE_CHAIN (tail))
1623 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1624 by modifying the last node in chain 1 to point to chain 2.
1625 This is the Lisp primitive `nconc'. */
1637 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1639 TREE_CHAIN (t1) = op2;
1640 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1642 abort (); /* Circularity created. */
1648 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1652 register tree chain;
1656 while (next = TREE_CHAIN (chain))
1661 /* Reverse the order of elements in the chain T,
1662 and return the new head of the chain (old last element). */
1668 register tree prev = 0, decl, next;
1669 for (decl = t; decl; decl = next)
1671 next = TREE_CHAIN (decl);
1672 TREE_CHAIN (decl) = prev;
1678 /* Given a chain CHAIN of tree nodes,
1679 construct and return a list of those nodes. */
1685 tree result = NULL_TREE;
1686 tree in_tail = chain;
1687 tree out_tail = NULL_TREE;
1691 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1693 TREE_CHAIN (out_tail) = next;
1697 in_tail = TREE_CHAIN (in_tail);
1703 /* Return a newly created TREE_LIST node whose
1704 purpose and value fields are PARM and VALUE. */
1707 build_tree_list (parm, value)
1710 register tree t = make_node (TREE_LIST);
1711 TREE_PURPOSE (t) = parm;
1712 TREE_VALUE (t) = value;
1716 /* Similar, but build on the temp_decl_obstack. */
1719 build_decl_list (parm, value)
1723 register struct obstack *ambient_obstack = current_obstack;
1724 current_obstack = &temp_decl_obstack;
1725 node = build_tree_list (parm, value);
1726 current_obstack = ambient_obstack;
1730 /* Return a newly created TREE_LIST node whose
1731 purpose and value fields are PARM and VALUE
1732 and whose TREE_CHAIN is CHAIN. */
1735 tree_cons (purpose, value, chain)
1736 tree purpose, value, chain;
1739 register tree node = make_node (TREE_LIST);
1742 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
1743 #ifdef GATHER_STATISTICS
1744 tree_node_counts[(int)x_kind]++;
1745 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
1748 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
1749 ((int *) node)[i] = 0;
1751 TREE_SET_CODE (node, TREE_LIST);
1752 if (current_obstack == &permanent_obstack)
1753 TREE_PERMANENT (node) = 1;
1756 TREE_CHAIN (node) = chain;
1757 TREE_PURPOSE (node) = purpose;
1758 TREE_VALUE (node) = value;
1762 /* Similar, but build on the temp_decl_obstack. */
1765 decl_tree_cons (purpose, value, chain)
1766 tree purpose, value, chain;
1769 register struct obstack *ambient_obstack = current_obstack;
1770 current_obstack = &temp_decl_obstack;
1771 node = tree_cons (purpose, value, chain);
1772 current_obstack = ambient_obstack;
1776 /* Same as `tree_cons' but make a permanent object. */
1779 perm_tree_cons (purpose, value, chain)
1780 tree purpose, value, chain;
1783 register struct obstack *ambient_obstack = current_obstack;
1784 current_obstack = &permanent_obstack;
1786 node = tree_cons (purpose, value, chain);
1787 current_obstack = ambient_obstack;
1791 /* Same as `tree_cons', but make this node temporary, regardless. */
1794 temp_tree_cons (purpose, value, chain)
1795 tree purpose, value, chain;
1798 register struct obstack *ambient_obstack = current_obstack;
1799 current_obstack = &temporary_obstack;
1801 node = tree_cons (purpose, value, chain);
1802 current_obstack = ambient_obstack;
1806 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
1809 saveable_tree_cons (purpose, value, chain)
1810 tree purpose, value, chain;
1813 register struct obstack *ambient_obstack = current_obstack;
1814 current_obstack = saveable_obstack;
1816 node = tree_cons (purpose, value, chain);
1817 current_obstack = ambient_obstack;
1821 /* Return the size nominally occupied by an object of type TYPE
1822 when it resides in memory. The value is measured in units of bytes,
1823 and its data type is that normally used for type sizes
1824 (which is the first type created by make_signed_type or
1825 make_unsigned_type). */
1828 size_in_bytes (type)
1833 if (type == error_mark_node)
1834 return integer_zero_node;
1835 type = TYPE_MAIN_VARIANT (type);
1836 if (TYPE_SIZE (type) == 0)
1838 incomplete_type_error (NULL_TREE, type);
1839 return integer_zero_node;
1841 t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1842 size_int (BITS_PER_UNIT));
1843 if (TREE_CODE (t) == INTEGER_CST)
1844 force_fit_type (t, 0);
1848 /* Return the size of TYPE (in bytes) as an integer,
1849 or return -1 if the size can vary. */
1852 int_size_in_bytes (type)
1856 if (type == error_mark_node)
1858 type = TYPE_MAIN_VARIANT (type);
1859 if (TYPE_SIZE (type) == 0)
1861 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1863 if (TREE_INT_CST_HIGH (TYPE_SIZE (type)) != 0)
1865 tree t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1866 size_int (BITS_PER_UNIT));
1867 return TREE_INT_CST_LOW (t);
1869 size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1870 return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1873 /* Return, as a tree node, the number of elements for TYPE (which is an
1874 ARRAY_TYPE) minus one. This counts only elements of the top array. */
1877 array_type_nelts (type)
1880 tree index_type = TYPE_DOMAIN (type);
1882 return (integer_zerop (TYPE_MIN_VALUE (index_type))
1883 ? TYPE_MAX_VALUE (index_type)
1884 : fold (build (MINUS_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)),
1885 TYPE_MAX_VALUE (index_type),
1886 TYPE_MIN_VALUE (index_type))));
1889 /* Return nonzero if arg is static -- a reference to an object in
1890 static storage. This is not the same as the C meaning of `static'. */
1896 switch (TREE_CODE (arg))
1900 return TREE_STATIC (arg) || DECL_EXTERNAL (arg);
1903 return TREE_STATIC (arg);
1910 return staticp (TREE_OPERAND (arg, 0));
1913 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
1916 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1917 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1918 return staticp (TREE_OPERAND (arg, 0));
1924 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
1925 Do this to any expression which may be used in more than one place,
1926 but must be evaluated only once.
1928 Normally, expand_expr would reevaluate the expression each time.
1929 Calling save_expr produces something that is evaluated and recorded
1930 the first time expand_expr is called on it. Subsequent calls to
1931 expand_expr just reuse the recorded value.
1933 The call to expand_expr that generates code that actually computes
1934 the value is the first call *at compile time*. Subsequent calls
1935 *at compile time* generate code to use the saved value.
1936 This produces correct result provided that *at run time* control
1937 always flows through the insns made by the first expand_expr
1938 before reaching the other places where the save_expr was evaluated.
1939 You, the caller of save_expr, must make sure this is so.
1941 Constants, and certain read-only nodes, are returned with no
1942 SAVE_EXPR because that is safe. Expressions containing placeholders
1943 are not touched; see tree.def for an explanation of what these
1950 register tree t = fold (expr);
1952 /* We don't care about whether this can be used as an lvalue in this
1954 while (TREE_CODE (t) == NON_LVALUE_EXPR)
1955 t = TREE_OPERAND (t, 0);
1957 /* If the tree evaluates to a constant, then we don't want to hide that
1958 fact (i.e. this allows further folding, and direct checks for constants).
1959 However, a read-only object that has side effects cannot be bypassed.
1960 Since it is no problem to reevaluate literals, we just return the
1963 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
1964 || TREE_CODE (t) == SAVE_EXPR)
1967 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
1968 it means that the size or offset of some field of an object depends on
1969 the value within another field.
1971 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
1972 and some variable since it would then need to be both evaluated once and
1973 evaluated more than once. Front-ends must assure this case cannot
1974 happen by surrounding any such subexpressions in their own SAVE_EXPR
1975 and forcing evaluation at the proper time. */
1976 if (contains_placeholder_p (t))
1979 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
1981 /* This expression might be placed ahead of a jump to ensure that the
1982 value was computed on both sides of the jump. So make sure it isn't
1983 eliminated as dead. */
1984 TREE_SIDE_EFFECTS (t) = 1;
1988 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
1989 or offset that depends on a field within a record.
1991 Note that we only allow such expressions within simple arithmetic
1995 contains_placeholder_p (exp)
1998 register enum tree_code code = TREE_CODE (exp);
2001 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2002 in it since it is supplying a value for it. */
2003 if (code == WITH_RECORD_EXPR)
2006 switch (TREE_CODE_CLASS (code))
2009 for (inner = TREE_OPERAND (exp, 0);
2010 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2011 inner = TREE_OPERAND (inner, 0))
2013 return TREE_CODE (inner) == PLACEHOLDER_EXPR;
2018 switch (tree_code_length[(int) code])
2021 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2023 return (code != RTL_EXPR
2024 && code != CONSTRUCTOR
2025 && ! (code == SAVE_EXPR && SAVE_EXPR_RTL (exp) != 0)
2026 && code != WITH_RECORD_EXPR
2027 && (contains_placeholder_p (TREE_OPERAND (exp, 0))
2028 || contains_placeholder_p (TREE_OPERAND (exp, 1))));
2030 return (code == COND_EXPR
2031 && (contains_placeholder_p (TREE_OPERAND (exp, 0))
2032 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2033 || contains_placeholder_p (TREE_OPERAND (exp, 2))));
2040 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2041 return a tree with all occurrences of references to F in a
2042 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2043 contains only arithmetic expressions. */
2046 substitute_in_expr (exp, f, r)
2051 enum tree_code code = TREE_CODE (exp);
2054 switch (TREE_CODE_CLASS (code))
2061 if (code == PLACEHOLDER_EXPR)
2069 switch (tree_code_length[(int) code])
2072 return fold (build1 (code, TREE_TYPE (exp),
2073 substitute_in_expr (TREE_OPERAND (exp, 0),
2077 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2078 could, but we don't support it. */
2079 if (code == RTL_EXPR)
2081 else if (code == CONSTRUCTOR)
2084 return fold (build (code, TREE_TYPE (exp),
2085 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2086 substitute_in_expr (TREE_OPERAND (exp, 1),
2090 /* It cannot be that anything inside a SAVE_EXPR contains a
2091 PLACEHOLDER_EXPR. */
2092 if (code == SAVE_EXPR)
2095 if (code != COND_EXPR)
2098 return fold (build (code, TREE_TYPE (exp),
2099 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2100 substitute_in_expr (TREE_OPERAND (exp, 1), f, r),
2101 substitute_in_expr (TREE_OPERAND (exp, 2),
2111 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2112 and it is the right field, replace it with R. */
2113 for (inner = TREE_OPERAND (exp, 0);
2114 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2115 inner = TREE_OPERAND (inner, 0))
2117 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2118 && TREE_OPERAND (exp, 1) == f)
2121 return fold (build (code, TREE_TYPE (exp),
2122 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2123 TREE_OPERAND (exp, 1)));
2125 return fold (build (code, TREE_TYPE (exp),
2126 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2127 substitute_in_expr (TREE_OPERAND (exp, 1), f, r),
2128 substitute_in_expr (TREE_OPERAND (exp, 2), f, r)));
2131 return fold (build1 (code, TREE_TYPE (exp),
2132 substitute_in_expr (TREE_OPERAND (exp, 0),
2135 return fold (build (code, TREE_TYPE (exp),
2136 substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
2137 substitute_in_expr (TREE_OPERAND (exp, 1), f, r)));
2141 /* If it wasn't one of the cases we handle, give up. */
2146 /* Given a type T, a FIELD_DECL F, and a replacement value R,
2147 return a new type with all size expressions that contain F
2148 updated by replacing F with R. */
2151 substitute_in_type (t, f, r)
2154 switch (TREE_CODE (t))
2163 if ((TREE_CODE (TYPE_MIN_VALUE (t)) != INTEGER_CST
2164 && contains_placeholder_p (TYPE_MIN_VALUE (t)))
2165 || (TREE_CODE (TYPE_MAX_VALUE (t)) != INTEGER_CST
2166 && contains_placeholder_p (TYPE_MAX_VALUE (t))))
2167 return build_range_type (t,
2168 substitute_in_expr (TYPE_MIN_VALUE (t), f, r),
2169 substitute_in_expr (TYPE_MAX_VALUE (t), f, r));
2173 if ((TYPE_MIN_VALUE (t) != 0
2174 && TREE_CODE (TYPE_MIN_VALUE (t)) != REAL_CST
2175 && contains_placeholder_p (TYPE_MIN_VALUE (t)))
2176 || (TYPE_MAX_VALUE (t) != 0
2177 && TREE_CODE (TYPE_MAX_VALUE (t)) != REAL_CST
2178 && contains_placeholder_p (TYPE_MAX_VALUE (t))))
2180 t = build_type_copy (t);
2182 if (TYPE_MIN_VALUE (t))
2183 TYPE_MIN_VALUE (t) = substitute_in_expr (TYPE_MIN_VALUE (t), f, r);
2184 if (TYPE_MAX_VALUE (t))
2185 TYPE_MAX_VALUE (t) = substitute_in_expr (TYPE_MAX_VALUE (t), f, r);
2190 return build_complex_type (substitute_in_type (TREE_TYPE (t), f, r));
2194 case REFERENCE_TYPE:
2199 /* Don't know how to do these yet. */
2203 t = build_array_type (substitute_in_type (TREE_TYPE (t), f, r),
2204 substitute_in_type (TYPE_DOMAIN (t), f, r));
2211 case QUAL_UNION_TYPE:
2213 tree new = copy_node (t);
2215 tree last_field = 0;
2217 /* Start out with no fields, make new fields, and chain them
2220 TYPE_FIELDS (new) = 0;
2221 TYPE_SIZE (new) = 0;
2223 for (field = TYPE_FIELDS (t); field;
2224 field = TREE_CHAIN (field))
2226 tree new_field = copy_node (field);
2228 TREE_TYPE (new_field)
2229 = substitute_in_type (TREE_TYPE (new_field), f, r);
2231 /* If this is an anonymous field and the type of this field is
2232 a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If
2233 the type just has one element, treat that as the field.
2234 But don't do this if we are processing a QUAL_UNION_TYPE. */
2235 if (TREE_CODE (t) != QUAL_UNION_TYPE && DECL_NAME (new_field) == 0
2236 && (TREE_CODE (TREE_TYPE (new_field)) == UNION_TYPE
2237 || TREE_CODE (TREE_TYPE (new_field)) == RECORD_TYPE))
2239 if (TYPE_FIELDS (TREE_TYPE (new_field)) == 0)
2242 if (TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new_field))) == 0)
2243 new_field = TYPE_FIELDS (TREE_TYPE (new_field));
2246 DECL_CONTEXT (new_field) = new;
2247 DECL_SIZE (new_field) = 0;
2249 if (TREE_CODE (t) == QUAL_UNION_TYPE)
2251 /* Do the substitution inside the qualifier and if we find
2252 that this field will not be present, omit it. */
2253 DECL_QUALIFIER (new_field)
2254 = substitute_in_expr (DECL_QUALIFIER (field), f, r);
2255 if (integer_zerop (DECL_QUALIFIER (new_field)))
2259 if (last_field == 0)
2260 TYPE_FIELDS (new) = new_field;
2262 TREE_CHAIN (last_field) = new_field;
2264 last_field = new_field;
2266 /* If this is a qualified type and this field will always be
2267 present, we are done. */
2268 if (TREE_CODE (t) == QUAL_UNION_TYPE
2269 && integer_onep (DECL_QUALIFIER (new_field)))
2273 /* If this used to be a qualified union type, but we now know what
2274 field will be present, make this a normal union. */
2275 if (TREE_CODE (new) == QUAL_UNION_TYPE
2276 && (TYPE_FIELDS (new) == 0
2277 || integer_onep (DECL_QUALIFIER (TYPE_FIELDS (new)))))
2278 TREE_SET_CODE (new, UNION_TYPE);
2286 /* Stabilize a reference so that we can use it any number of times
2287 without causing its operands to be evaluated more than once.
2288 Returns the stabilized reference. This works by means of save_expr,
2289 so see the caveats in the comments about save_expr.
2291 Also allows conversion expressions whose operands are references.
2292 Any other kind of expression is returned unchanged. */
2295 stabilize_reference (ref)
2298 register tree result;
2299 register enum tree_code code = TREE_CODE (ref);
2306 /* No action is needed in this case. */
2312 case FIX_TRUNC_EXPR:
2313 case FIX_FLOOR_EXPR:
2314 case FIX_ROUND_EXPR:
2316 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2320 result = build_nt (INDIRECT_REF,
2321 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2325 result = build_nt (COMPONENT_REF,
2326 stabilize_reference (TREE_OPERAND (ref, 0)),
2327 TREE_OPERAND (ref, 1));
2331 result = build_nt (BIT_FIELD_REF,
2332 stabilize_reference (TREE_OPERAND (ref, 0)),
2333 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2334 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2338 result = build_nt (ARRAY_REF,
2339 stabilize_reference (TREE_OPERAND (ref, 0)),
2340 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2343 /* If arg isn't a kind of lvalue we recognize, make no change.
2344 Caller should recognize the error for an invalid lvalue. */
2349 return error_mark_node;
2352 TREE_TYPE (result) = TREE_TYPE (ref);
2353 TREE_READONLY (result) = TREE_READONLY (ref);
2354 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2355 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2356 TREE_RAISES (result) = TREE_RAISES (ref);
2361 /* Subroutine of stabilize_reference; this is called for subtrees of
2362 references. Any expression with side-effects must be put in a SAVE_EXPR
2363 to ensure that it is only evaluated once.
2365 We don't put SAVE_EXPR nodes around everything, because assigning very
2366 simple expressions to temporaries causes us to miss good opportunities
2367 for optimizations. Among other things, the opportunity to fold in the
2368 addition of a constant into an addressing mode often gets lost, e.g.
2369 "y[i+1] += x;". In general, we take the approach that we should not make
2370 an assignment unless we are forced into it - i.e., that any non-side effect
2371 operator should be allowed, and that cse should take care of coalescing
2372 multiple utterances of the same expression should that prove fruitful. */
2375 stabilize_reference_1 (e)
2378 register tree result;
2379 register enum tree_code code = TREE_CODE (e);
2381 /* We cannot ignore const expressions because it might be a reference
2382 to a const array but whose index contains side-effects. But we can
2383 ignore things that are actual constant or that already have been
2384 handled by this function. */
2386 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2389 switch (TREE_CODE_CLASS (code))
2399 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2400 so that it will only be evaluated once. */
2401 /* The reference (r) and comparison (<) classes could be handled as
2402 below, but it is generally faster to only evaluate them once. */
2403 if (TREE_SIDE_EFFECTS (e))
2404 return save_expr (e);
2408 /* Constants need no processing. In fact, we should never reach
2413 /* Division is slow and tends to be compiled with jumps,
2414 especially the division by powers of 2 that is often
2415 found inside of an array reference. So do it just once. */
2416 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2417 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2418 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2419 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2420 return save_expr (e);
2421 /* Recursively stabilize each operand. */
2422 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2423 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2427 /* Recursively stabilize each operand. */
2428 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2435 TREE_TYPE (result) = TREE_TYPE (e);
2436 TREE_READONLY (result) = TREE_READONLY (e);
2437 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2438 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2439 TREE_RAISES (result) = TREE_RAISES (e);
2444 /* Low-level constructors for expressions. */
2446 /* Build an expression of code CODE, data type TYPE,
2447 and operands as specified by the arguments ARG1 and following arguments.
2448 Expressions and reference nodes can be created this way.
2449 Constants, decls, types and misc nodes cannot be. */
2452 build VPROTO((enum tree_code code, tree tt, ...))
2455 enum tree_code code;
2460 register int length;
2466 code = va_arg (p, enum tree_code);
2467 tt = va_arg (p, tree);
2470 t = make_node (code);
2471 length = tree_code_length[(int) code];
2476 /* This is equivalent to the loop below, but faster. */
2477 register tree arg0 = va_arg (p, tree);
2478 register tree arg1 = va_arg (p, tree);
2479 TREE_OPERAND (t, 0) = arg0;
2480 TREE_OPERAND (t, 1) = arg1;
2481 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
2482 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
2483 TREE_SIDE_EFFECTS (t) = 1;
2485 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
2487 else if (length == 1)
2489 register tree arg0 = va_arg (p, tree);
2491 /* Call build1 for this! */
2492 if (TREE_CODE_CLASS (code) != 's')
2494 TREE_OPERAND (t, 0) = arg0;
2495 if (arg0 && TREE_SIDE_EFFECTS (arg0))
2496 TREE_SIDE_EFFECTS (t) = 1;
2497 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
2501 for (i = 0; i < length; i++)
2503 register tree operand = va_arg (p, tree);
2504 TREE_OPERAND (t, i) = operand;
2507 if (TREE_SIDE_EFFECTS (operand))
2508 TREE_SIDE_EFFECTS (t) = 1;
2509 if (TREE_RAISES (operand))
2510 TREE_RAISES (t) = 1;
2518 /* Same as above, but only builds for unary operators.
2519 Saves lions share of calls to `build'; cuts down use
2520 of varargs, which is expensive for RISC machines. */
2522 build1 (code, type, node)
2523 enum tree_code code;
2527 register struct obstack *obstack = current_obstack;
2528 register int i, length;
2529 register tree_node_kind kind;
2532 #ifdef GATHER_STATISTICS
2533 if (TREE_CODE_CLASS (code) == 'r')
2539 obstack = expression_obstack;
2540 length = sizeof (struct tree_exp);
2542 t = (tree) obstack_alloc (obstack, length);
2544 #ifdef GATHER_STATISTICS
2545 tree_node_counts[(int)kind]++;
2546 tree_node_sizes[(int)kind] += length;
2549 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
2552 TREE_TYPE (t) = type;
2553 TREE_SET_CODE (t, code);
2555 if (obstack == &permanent_obstack)
2556 TREE_PERMANENT (t) = 1;
2558 TREE_OPERAND (t, 0) = node;
2561 if (TREE_SIDE_EFFECTS (node))
2562 TREE_SIDE_EFFECTS (t) = 1;
2563 if (TREE_RAISES (node))
2564 TREE_RAISES (t) = 1;
2570 /* Similar except don't specify the TREE_TYPE
2571 and leave the TREE_SIDE_EFFECTS as 0.
2572 It is permissible for arguments to be null,
2573 or even garbage if their values do not matter. */
2576 build_nt VPROTO((enum tree_code code, ...))
2579 enum tree_code code;
2583 register int length;
2589 code = va_arg (p, enum tree_code);
2592 t = make_node (code);
2593 length = tree_code_length[(int) code];
2595 for (i = 0; i < length; i++)
2596 TREE_OPERAND (t, i) = va_arg (p, tree);
2602 /* Similar to `build_nt', except we build
2603 on the temp_decl_obstack, regardless. */
2606 build_parse_node VPROTO((enum tree_code code, ...))
2609 enum tree_code code;
2611 register struct obstack *ambient_obstack = expression_obstack;
2614 register int length;
2620 code = va_arg (p, enum tree_code);
2623 expression_obstack = &temp_decl_obstack;
2625 t = make_node (code);
2626 length = tree_code_length[(int) code];
2628 for (i = 0; i < length; i++)
2629 TREE_OPERAND (t, i) = va_arg (p, tree);
2632 expression_obstack = ambient_obstack;
2637 /* Commented out because this wants to be done very
2638 differently. See cp-lex.c. */
2640 build_op_identifier (op1, op2)
2643 register tree t = make_node (OP_IDENTIFIER);
2644 TREE_PURPOSE (t) = op1;
2645 TREE_VALUE (t) = op2;
2650 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
2651 We do NOT enter this node in any sort of symbol table.
2653 layout_decl is used to set up the decl's storage layout.
2654 Other slots are initialized to 0 or null pointers. */
2657 build_decl (code, name, type)
2658 enum tree_code code;
2663 t = make_node (code);
2665 /* if (type == error_mark_node)
2666 type = integer_type_node; */
2667 /* That is not done, deliberately, so that having error_mark_node
2668 as the type can suppress useless errors in the use of this variable. */
2670 DECL_NAME (t) = name;
2671 DECL_ASSEMBLER_NAME (t) = name;
2672 TREE_TYPE (t) = type;
2674 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
2676 else if (code == FUNCTION_DECL)
2677 DECL_MODE (t) = FUNCTION_MODE;
2682 /* BLOCK nodes are used to represent the structure of binding contours
2683 and declarations, once those contours have been exited and their contents
2684 compiled. This information is used for outputting debugging info. */
2687 build_block (vars, tags, subblocks, supercontext, chain)
2688 tree vars, tags, subblocks, supercontext, chain;
2690 register tree block = make_node (BLOCK);
2691 BLOCK_VARS (block) = vars;
2692 BLOCK_TYPE_TAGS (block) = tags;
2693 BLOCK_SUBBLOCKS (block) = subblocks;
2694 BLOCK_SUPERCONTEXT (block) = supercontext;
2695 BLOCK_CHAIN (block) = chain;
2699 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
2700 and its TYPE_VOLATILE is VOLATILEP.
2702 Such variant types already made are recorded so that duplicates
2705 A variant types should never be used as the type of an expression.
2706 Always copy the variant information into the TREE_READONLY
2707 and TREE_THIS_VOLATILE of the expression, and then give the expression
2708 as its type the "main variant", the variant whose TYPE_READONLY
2709 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
2713 build_type_variant (type, constp, volatilep)
2715 int constp, volatilep;
2719 /* Treat any nonzero argument as 1. */
2721 volatilep = !!volatilep;
2723 /* If not generating auxiliary info, search the chain of variants to see
2724 if there is already one there just like the one we need to have. If so,
2725 use that existing one.
2727 We don't do this in the case where we are generating aux info because
2728 in that case we want each typedef names to get it's own distinct type
2729 node, even if the type of this new typedef is the same as some other
2732 if (!flag_gen_aux_info)
2733 for (t = TYPE_MAIN_VARIANT(type); t; t = TYPE_NEXT_VARIANT (t))
2734 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t))
2737 /* We need a new one. */
2739 t = build_type_copy (type);
2740 TYPE_READONLY (t) = constp;
2741 TYPE_VOLATILE (t) = volatilep;
2746 /* Give TYPE a new main variant: NEW_MAIN.
2747 This is the right thing to do only when something else
2748 about TYPE is modified in place. */
2751 change_main_variant (type, new_main)
2752 tree type, new_main;
2755 tree omain = TYPE_MAIN_VARIANT (type);
2757 /* Remove TYPE from the TYPE_NEXT_VARIANT chain of its main variant. */
2758 if (TYPE_NEXT_VARIANT (omain) == type)
2759 TYPE_NEXT_VARIANT (omain) = TYPE_NEXT_VARIANT (type);
2761 for (t = TYPE_NEXT_VARIANT (omain); t && TYPE_NEXT_VARIANT (t);
2762 t = TYPE_NEXT_VARIANT (t))
2763 if (TYPE_NEXT_VARIANT (t) == type)
2765 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (type);
2769 TYPE_MAIN_VARIANT (type) = new_main;
2770 TYPE_NEXT_VARIANT (type) = TYPE_NEXT_VARIANT (new_main);
2771 TYPE_NEXT_VARIANT (new_main) = type;
2774 /* Create a new variant of TYPE, equivalent but distinct.
2775 This is so the caller can modify it. */
2778 build_type_copy (type)
2781 register tree t, m = TYPE_MAIN_VARIANT (type);
2782 register struct obstack *ambient_obstack = current_obstack;
2784 current_obstack = TYPE_OBSTACK (type);
2785 t = copy_node (type);
2786 current_obstack = ambient_obstack;
2788 TYPE_POINTER_TO (t) = 0;
2789 TYPE_REFERENCE_TO (t) = 0;
2791 /* Add this type to the chain of variants of TYPE. */
2792 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2793 TYPE_NEXT_VARIANT (m) = t;
2798 /* Hashing of types so that we don't make duplicates.
2799 The entry point is `type_hash_canon'. */
2801 /* Each hash table slot is a bucket containing a chain
2802 of these structures. */
2806 struct type_hash *next; /* Next structure in the bucket. */
2807 int hashcode; /* Hash code of this type. */
2808 tree type; /* The type recorded here. */
2811 /* Now here is the hash table. When recording a type, it is added
2812 to the slot whose index is the hash code mod the table size.
2813 Note that the hash table is used for several kinds of types
2814 (function types, array types and array index range types, for now).
2815 While all these live in the same table, they are completely independent,
2816 and the hash code is computed differently for each of these. */
2818 #define TYPE_HASH_SIZE 59
2819 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
2821 /* Here is how primitive or already-canonicalized types' hash
2823 #define TYPE_HASH(TYPE) ((HOST_WIDE_INT) (TYPE) & 0777777)
2825 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
2826 with types in the TREE_VALUE slots), by adding the hash codes
2827 of the individual types. */
2830 type_hash_list (list)
2833 register int hashcode;
2835 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
2836 hashcode += TYPE_HASH (TREE_VALUE (tail));
2840 /* Look in the type hash table for a type isomorphic to TYPE.
2841 If one is found, return it. Otherwise return 0. */
2844 type_hash_lookup (hashcode, type)
2848 register struct type_hash *h;
2849 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
2850 if (h->hashcode == hashcode
2851 && TREE_CODE (h->type) == TREE_CODE (type)
2852 && TREE_TYPE (h->type) == TREE_TYPE (type)
2853 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
2854 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
2855 TYPE_MAX_VALUE (type)))
2856 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
2857 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
2858 TYPE_MIN_VALUE (type)))
2859 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
2860 || (TYPE_DOMAIN (h->type)
2861 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
2862 && TYPE_DOMAIN (type)
2863 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
2864 && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
2869 /* Add an entry to the type-hash-table
2870 for a type TYPE whose hash code is HASHCODE. */
2873 type_hash_add (hashcode, type)
2877 register struct type_hash *h;
2879 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
2880 h->hashcode = hashcode;
2882 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
2883 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
2886 /* Given TYPE, and HASHCODE its hash code, return the canonical
2887 object for an identical type if one already exists.
2888 Otherwise, return TYPE, and record it as the canonical object
2889 if it is a permanent object.
2891 To use this function, first create a type of the sort you want.
2892 Then compute its hash code from the fields of the type that
2893 make it different from other similar types.
2894 Then call this function and use the value.
2895 This function frees the type you pass in if it is a duplicate. */
2897 /* Set to 1 to debug without canonicalization. Never set by program. */
2898 int debug_no_type_hash = 0;
2901 type_hash_canon (hashcode, type)
2907 if (debug_no_type_hash)
2910 t1 = type_hash_lookup (hashcode, type);
2913 obstack_free (TYPE_OBSTACK (type), type);
2914 #ifdef GATHER_STATISTICS
2915 tree_node_counts[(int)t_kind]--;
2916 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
2921 /* If this is a permanent type, record it for later reuse. */
2922 if (TREE_PERMANENT (type))
2923 type_hash_add (hashcode, type);
2928 /* Given two lists of types
2929 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
2930 return 1 if the lists contain the same types in the same order.
2931 Also, the TREE_PURPOSEs must match. */
2934 type_list_equal (l1, l2)
2937 register tree t1, t2;
2938 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
2940 if (TREE_VALUE (t1) != TREE_VALUE (t2))
2942 if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2))
2944 int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
2955 /* Nonzero if integer constants T1 and T2
2956 represent the same constant value. */
2959 tree_int_cst_equal (t1, t2)
2964 if (t1 == 0 || t2 == 0)
2966 if (TREE_CODE (t1) == INTEGER_CST
2967 && TREE_CODE (t2) == INTEGER_CST
2968 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2969 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
2974 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
2975 The precise way of comparison depends on their data type. */
2978 tree_int_cst_lt (t1, t2)
2984 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
2985 return INT_CST_LT (t1, t2);
2986 return INT_CST_LT_UNSIGNED (t1, t2);
2989 /* Return an indication of the sign of the integer constant T.
2990 The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
2991 Note that -1 will never be returned it T's type is unsigned. */
2994 tree_int_cst_sgn (t)
2997 if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
2999 else if (TREE_UNSIGNED (TREE_TYPE (t)))
3001 else if (TREE_INT_CST_HIGH (t) < 0)
3007 /* Compare two constructor-element-type constants. */
3009 simple_cst_list_equal (l1, l2)
3012 while (l1 != NULL_TREE && l2 != NULL_TREE)
3014 int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2));
3019 l1 = TREE_CHAIN (l1);
3020 l2 = TREE_CHAIN (l2);
3025 /* Return truthvalue of whether T1 is the same tree structure as T2.
3026 Return 1 if they are the same.
3027 Return 0 if they are understandably different.
3028 Return -1 if either contains tree structure not understood by
3032 simple_cst_equal (t1, t2)
3035 register enum tree_code code1, code2;
3040 if (t1 == 0 || t2 == 0)
3043 code1 = TREE_CODE (t1);
3044 code2 = TREE_CODE (t2);
3046 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
3047 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
3048 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3050 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
3051 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3052 || code2 == NON_LVALUE_EXPR)
3053 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
3061 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3062 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
3065 return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
3068 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
3069 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
3070 TREE_STRING_LENGTH (t1));
3076 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3079 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3082 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3085 /* Special case: if either target is an unallocated VAR_DECL,
3086 it means that it's going to be unified with whatever the
3087 TARGET_EXPR is really supposed to initialize, so treat it
3088 as being equivalent to anything. */
3089 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
3090 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
3091 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
3092 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
3093 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
3094 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
3097 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3100 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3102 case WITH_CLEANUP_EXPR:
3103 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3106 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
3109 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
3110 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3120 /* This general rule works for most tree codes.
3121 All exceptions should be handled above. */
3123 switch (TREE_CODE_CLASS (code1))
3133 for (i=0; i<tree_code_length[(int) code1]; ++i)
3135 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
3145 /* Constructors for pointer, array and function types.
3146 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
3147 constructed by language-dependent code, not here.) */
3149 /* Construct, lay out and return the type of pointers to TO_TYPE.
3150 If such a type has already been constructed, reuse it. */
3153 build_pointer_type (to_type)
3156 register tree t = TYPE_POINTER_TO (to_type);
3158 /* First, if we already have a type for pointers to TO_TYPE, use it. */
3163 /* We need a new one. Put this in the same obstack as TO_TYPE. */
3164 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
3165 t = make_node (POINTER_TYPE);
3168 TREE_TYPE (t) = to_type;
3170 /* Record this type as the pointer to TO_TYPE. */
3171 TYPE_POINTER_TO (to_type) = t;
3173 /* Lay out the type. This function has many callers that are concerned
3174 with expression-construction, and this simplifies them all.
3175 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
3181 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
3182 MAXVAL should be the maximum value in the domain
3183 (one less than the length of the array). */
3186 build_index_type (maxval)
3189 register tree itype = make_node (INTEGER_TYPE);
3190 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
3191 TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
3192 TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
3193 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
3194 TYPE_MODE (itype) = TYPE_MODE (sizetype);
3195 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
3196 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
3197 if (TREE_CODE (maxval) == INTEGER_CST)
3199 int maxint = (int) TREE_INT_CST_LOW (maxval);
3200 /* If the domain should be empty, make sure the maxval
3201 remains -1 and is not spoiled by truncation. */
3202 if (INT_CST_LT (maxval, integer_zero_node))
3204 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
3205 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
3207 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
3213 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
3214 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
3215 low bound LOWVAL and high bound HIGHVAL.
3216 if TYPE==NULL_TREE, sizetype is used. */
3219 build_range_type (type, lowval, highval)
3220 tree type, lowval, highval;
3222 register tree itype = make_node (INTEGER_TYPE);
3223 TREE_TYPE (itype) = type;
3224 if (type == NULL_TREE)
3226 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
3227 TYPE_MIN_VALUE (itype) = convert (type, lowval);
3228 TYPE_MAX_VALUE (itype) = convert (type, highval);
3229 TYPE_MODE (itype) = TYPE_MODE (type);
3230 TYPE_SIZE (itype) = TYPE_SIZE (type);
3231 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
3232 if ((TREE_CODE (lowval) == INTEGER_CST)
3233 && (TREE_CODE (highval) == INTEGER_CST))
3235 HOST_WIDE_INT highint = TREE_INT_CST_LOW (highval);
3236 HOST_WIDE_INT lowint = TREE_INT_CST_LOW (lowval);
3237 int maxint = (int) (highint - lowint);
3238 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
3244 /* Just like build_index_type, but takes lowval and highval instead
3245 of just highval (maxval). */
3248 build_index_2_type (lowval,highval)
3249 tree lowval, highval;
3251 return build_range_type (NULL_TREE, lowval, highval);
3254 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
3255 Needed because when index types are not hashed, equal index types
3256 built at different times appear distinct, even though structurally,
3260 index_type_equal (itype1, itype2)
3261 tree itype1, itype2;
3263 if (TREE_CODE (itype1) != TREE_CODE (itype2))
3265 if (TREE_CODE (itype1) == INTEGER_TYPE)
3267 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
3268 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
3269 || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2))
3270 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
3272 if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2))
3273 && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2)))
3279 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
3280 and number of elements specified by the range of values of INDEX_TYPE.
3281 If such a type has already been constructed, reuse it. */
3284 build_array_type (elt_type, index_type)
3285 tree elt_type, index_type;
3290 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
3292 error ("arrays of functions are not meaningful");
3293 elt_type = integer_type_node;
3296 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
3297 build_pointer_type (elt_type);
3299 /* Allocate the array after the pointer type,
3300 in case we free it in type_hash_canon. */
3301 t = make_node (ARRAY_TYPE);
3302 TREE_TYPE (t) = elt_type;
3303 TYPE_DOMAIN (t) = index_type;
3305 if (index_type == 0)
3310 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
3311 t = type_hash_canon (hashcode, t);
3313 #if 0 /* This led to crashes, because it could put a temporary node
3314 on the TYPE_NEXT_VARIANT chain of a permanent one. */
3315 /* The main variant of an array type should always
3316 be an array whose element type is the main variant. */
3317 if (elt_type != TYPE_MAIN_VARIANT (elt_type))
3318 change_main_variant (t, build_array_type (TYPE_MAIN_VARIANT (elt_type),
3322 if (TYPE_SIZE (t) == 0)
3327 /* Construct, lay out and return
3328 the type of functions returning type VALUE_TYPE
3329 given arguments of types ARG_TYPES.
3330 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
3331 are data type nodes for the arguments of the function.
3332 If such a type has already been constructed, reuse it. */
3335 build_function_type (value_type, arg_types)
3336 tree value_type, arg_types;
3341 if (TREE_CODE (value_type) == FUNCTION_TYPE)
3343 error ("function return type cannot be function");
3344 value_type = integer_type_node;
3347 /* Make a node of the sort we want. */
3348 t = make_node (FUNCTION_TYPE);
3349 TREE_TYPE (t) = value_type;
3350 TYPE_ARG_TYPES (t) = arg_types;
3352 /* If we already have such a type, use the old one and free this one. */
3353 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
3354 t = type_hash_canon (hashcode, t);
3356 if (TYPE_SIZE (t) == 0)
3361 /* Build the node for the type of references-to-TO_TYPE. */
3364 build_reference_type (to_type)
3367 register tree t = TYPE_REFERENCE_TO (to_type);
3368 register struct obstack *ambient_obstack = current_obstack;
3369 register struct obstack *ambient_saveable_obstack = saveable_obstack;
3371 /* First, if we already have a type for pointers to TO_TYPE, use it. */
3376 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
3377 if (TREE_PERMANENT (to_type))
3379 current_obstack = &permanent_obstack;
3380 saveable_obstack = &permanent_obstack;
3383 t = make_node (REFERENCE_TYPE);
3384 TREE_TYPE (t) = to_type;
3386 /* Record this type as the pointer to TO_TYPE. */
3387 TYPE_REFERENCE_TO (to_type) = t;
3391 current_obstack = ambient_obstack;
3392 saveable_obstack = ambient_saveable_obstack;
3396 /* Construct, lay out and return the type of methods belonging to class
3397 BASETYPE and whose arguments and values are described by TYPE.
3398 If that type exists already, reuse it.
3399 TYPE must be a FUNCTION_TYPE node. */
3402 build_method_type (basetype, type)
3403 tree basetype, type;
3408 /* Make a node of the sort we want. */
3409 t = make_node (METHOD_TYPE);
3411 if (TREE_CODE (type) != FUNCTION_TYPE)
3414 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
3415 TREE_TYPE (t) = TREE_TYPE (type);
3417 /* The actual arglist for this function includes a "hidden" argument
3418 which is "this". Put it into the list of argument types. */
3421 = tree_cons (NULL_TREE,
3422 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
3424 /* If we already have such a type, use the old one and free this one. */
3425 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
3426 t = type_hash_canon (hashcode, t);
3428 if (TYPE_SIZE (t) == 0)
3434 /* Construct, lay out and return the type of offsets to a value
3435 of type TYPE, within an object of type BASETYPE.
3436 If a suitable offset type exists already, reuse it. */
3439 build_offset_type (basetype, type)
3440 tree basetype, type;
3445 /* Make a node of the sort we want. */
3446 t = make_node (OFFSET_TYPE);
3448 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
3449 TREE_TYPE (t) = type;
3451 /* If we already have such a type, use the old one and free this one. */
3452 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
3453 t = type_hash_canon (hashcode, t);
3455 if (TYPE_SIZE (t) == 0)
3461 /* Create a complex type whose components are COMPONENT_TYPE. */
3464 build_complex_type (component_type)
3465 tree component_type;
3470 /* Make a node of the sort we want. */
3471 t = make_node (COMPLEX_TYPE);
3473 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
3474 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
3475 TYPE_READONLY (t) = TYPE_READONLY (component_type);
3477 /* If we already have such a type, use the old one and free this one. */
3478 hashcode = TYPE_HASH (component_type);
3479 t = type_hash_canon (hashcode, t);
3481 if (TYPE_SIZE (t) == 0)
3487 /* Return OP, stripped of any conversions to wider types as much as is safe.
3488 Converting the value back to OP's type makes a value equivalent to OP.
3490 If FOR_TYPE is nonzero, we return a value which, if converted to
3491 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
3493 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
3494 narrowest type that can hold the value, even if they don't exactly fit.
3495 Otherwise, bit-field references are changed to a narrower type
3496 only if they can be fetched directly from memory in that type.
3498 OP must have integer, real or enumeral type. Pointers are not allowed!
3500 There are some cases where the obvious value we could return
3501 would regenerate to OP if converted to OP's type,
3502 but would not extend like OP to wider types.
3503 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
3504 For example, if OP is (unsigned short)(signed char)-1,
3505 we avoid returning (signed char)-1 if FOR_TYPE is int,
3506 even though extending that to an unsigned short would regenerate OP,
3507 since the result of extending (signed char)-1 to (int)
3508 is different from (int) OP. */
3511 get_unwidened (op, for_type)
3515 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
3516 /* TYPE_PRECISION is safe in place of type_precision since
3517 pointer types are not allowed. */
3518 register tree type = TREE_TYPE (op);
3519 register unsigned final_prec
3520 = TYPE_PRECISION (for_type != 0 ? for_type : type);
3522 = (for_type != 0 && for_type != type
3523 && final_prec > TYPE_PRECISION (type)
3524 && TREE_UNSIGNED (type));
3525 register tree win = op;
3527 while (TREE_CODE (op) == NOP_EXPR)
3529 register int bitschange
3530 = TYPE_PRECISION (TREE_TYPE (op))
3531 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3533 /* Truncations are many-one so cannot be removed.
3534 Unless we are later going to truncate down even farther. */
3536 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
3539 /* See what's inside this conversion. If we decide to strip it,
3541 op = TREE_OPERAND (op, 0);
3543 /* If we have not stripped any zero-extensions (uns is 0),
3544 we can strip any kind of extension.
3545 If we have previously stripped a zero-extension,
3546 only zero-extensions can safely be stripped.
3547 Any extension can be stripped if the bits it would produce
3548 are all going to be discarded later by truncating to FOR_TYPE. */
3552 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
3554 /* TREE_UNSIGNED says whether this is a zero-extension.
3555 Let's avoid computing it if it does not affect WIN
3556 and if UNS will not be needed again. */
3557 if ((uns || TREE_CODE (op) == NOP_EXPR)
3558 && TREE_UNSIGNED (TREE_TYPE (op)))
3566 if (TREE_CODE (op) == COMPONENT_REF
3567 /* Since type_for_size always gives an integer type. */
3568 && TREE_CODE (type) != REAL_TYPE)
3570 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3571 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
3573 /* We can get this structure field in the narrowest type it fits in.
3574 If FOR_TYPE is 0, do this only for a field that matches the
3575 narrower type exactly and is aligned for it
3576 The resulting extension to its nominal type (a fullword type)
3577 must fit the same conditions as for other extensions. */
3579 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3580 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
3581 && (! uns || final_prec <= innerprec
3582 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3585 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3586 TREE_OPERAND (op, 1));
3587 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3588 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3589 TREE_RAISES (win) = TREE_RAISES (op);
3595 /* Return OP or a simpler expression for a narrower value
3596 which can be sign-extended or zero-extended to give back OP.
3597 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
3598 or 0 if the value should be sign-extended. */
3601 get_narrower (op, unsignedp_ptr)
3605 register int uns = 0;
3607 register tree win = op;
3609 while (TREE_CODE (op) == NOP_EXPR)
3611 register int bitschange
3612 = TYPE_PRECISION (TREE_TYPE (op))
3613 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3615 /* Truncations are many-one so cannot be removed. */
3619 /* See what's inside this conversion. If we decide to strip it,
3621 op = TREE_OPERAND (op, 0);
3625 /* An extension: the outermost one can be stripped,
3626 but remember whether it is zero or sign extension. */
3628 uns = TREE_UNSIGNED (TREE_TYPE (op));
3629 /* Otherwise, if a sign extension has been stripped,
3630 only sign extensions can now be stripped;
3631 if a zero extension has been stripped, only zero-extensions. */
3632 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
3636 else /* bitschange == 0 */
3638 /* A change in nominal type can always be stripped, but we must
3639 preserve the unsignedness. */
3641 uns = TREE_UNSIGNED (TREE_TYPE (op));
3648 if (TREE_CODE (op) == COMPONENT_REF
3649 /* Since type_for_size always gives an integer type. */
3650 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
3652 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3653 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
3655 /* We can get this structure field in a narrower type that fits it,
3656 but the resulting extension to its nominal type (a fullword type)
3657 must satisfy the same conditions as for other extensions.
3659 Do this only for fields that are aligned (not bit-fields),
3660 because when bit-field insns will be used there is no
3661 advantage in doing this. */
3663 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3664 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
3665 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3669 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
3670 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3671 TREE_OPERAND (op, 1));
3672 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3673 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3674 TREE_RAISES (win) = TREE_RAISES (op);
3677 *unsignedp_ptr = uns;
3681 /* Return the precision of a type, for arithmetic purposes.
3682 Supports all types on which arithmetic is possible
3683 (including pointer types).
3684 It's not clear yet what will be right for complex types. */
3687 type_precision (type)
3690 return ((TREE_CODE (type) == INTEGER_TYPE
3691 || TREE_CODE (type) == ENUMERAL_TYPE
3692 || TREE_CODE (type) == REAL_TYPE)
3693 ? TYPE_PRECISION (type) : POINTER_SIZE);
3696 /* Nonzero if integer constant C has a value that is permissible
3697 for type TYPE (an INTEGER_TYPE). */
3700 int_fits_type_p (c, type)
3703 if (TREE_UNSIGNED (type))
3704 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
3705 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
3706 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
3707 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type))));
3709 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
3710 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
3711 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
3712 && INT_CST_LT (c, TYPE_MIN_VALUE (type))));
3715 /* Return the innermost context enclosing DECL that is
3716 a FUNCTION_DECL, or zero if none. */
3719 decl_function_context (decl)
3724 if (TREE_CODE (decl) == ERROR_MARK)
3727 if (TREE_CODE (decl) == SAVE_EXPR)
3728 context = SAVE_EXPR_CONTEXT (decl);
3730 context = DECL_CONTEXT (decl);
3732 while (context && TREE_CODE (context) != FUNCTION_DECL)
3734 if (TREE_CODE (context) == RECORD_TYPE
3735 || TREE_CODE (context) == UNION_TYPE)
3736 context = TYPE_CONTEXT (context);
3737 else if (TREE_CODE (context) == TYPE_DECL)
3738 context = DECL_CONTEXT (context);
3739 else if (TREE_CODE (context) == BLOCK)
3740 context = BLOCK_SUPERCONTEXT (context);
3742 /* Unhandled CONTEXT !? */
3749 /* Return the innermost context enclosing DECL that is
3750 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
3751 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
3754 decl_type_context (decl)
3757 tree context = DECL_CONTEXT (decl);
3761 if (TREE_CODE (context) == RECORD_TYPE
3762 || TREE_CODE (context) == UNION_TYPE
3763 || TREE_CODE (context) == QUAL_UNION_TYPE)
3765 if (TREE_CODE (context) == TYPE_DECL
3766 || TREE_CODE (context) == FUNCTION_DECL)
3767 context = DECL_CONTEXT (context);
3768 else if (TREE_CODE (context) == BLOCK)
3769 context = BLOCK_SUPERCONTEXT (context);
3771 /* Unhandled CONTEXT!? */
3778 print_obstack_statistics (str, o)
3782 struct _obstack_chunk *chunk = o->chunk;
3789 n_alloc += chunk->limit - &chunk->contents[0];
3790 chunk = chunk->prev;
3792 fprintf (stderr, "obstack %s: %d bytes, %d chunks\n",
3793 str, n_alloc, n_chunks);
3796 dump_tree_statistics ()
3799 int total_nodes, total_bytes;
3801 fprintf (stderr, "\n??? tree nodes created\n\n");
3802 #ifdef GATHER_STATISTICS
3803 fprintf (stderr, "Kind Nodes Bytes\n");
3804 fprintf (stderr, "-------------------------------------\n");
3805 total_nodes = total_bytes = 0;
3806 for (i = 0; i < (int) all_kinds; i++)
3808 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
3809 tree_node_counts[i], tree_node_sizes[i]);
3810 total_nodes += tree_node_counts[i];
3811 total_bytes += tree_node_sizes[i];
3813 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
3814 fprintf (stderr, "-------------------------------------\n");
3815 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
3816 fprintf (stderr, "-------------------------------------\n");
3818 fprintf (stderr, "(No per-node statistics)\n");
3820 print_lang_statistics ();
3823 #define FILE_FUNCTION_PREFIX_LEN 9
3825 #ifndef NO_DOLLAR_IN_LABEL
3826 #define FILE_FUNCTION_FORMAT "_GLOBAL_$D$%s"
3827 #else /* NO_DOLLAR_IN_LABEL */
3828 #ifndef NO_DOT_IN_LABEL
3829 #define FILE_FUNCTION_FORMAT "_GLOBAL_.D.%s"
3830 #else /* NO_DOT_IN_LABEL */
3831 #define FILE_FUNCTION_FORMAT "_GLOBAL__D_%s"
3832 #endif /* NO_DOT_IN_LABEL */
3833 #endif /* NO_DOLLAR_IN_LABEL */
3835 extern char * first_global_object_name;
3837 /* If KIND=='I', return a suitable global initializer (constructor) name.
3838 If KIND=='D', return a suitable global clean-up (destructor) name. */
3841 get_file_function_name (kind)
3847 if (first_global_object_name)
3848 p = first_global_object_name;
3849 else if (main_input_filename)
3850 p = main_input_filename;
3854 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p));
3856 /* Set up the name of the file-level functions we may need. */
3857 /* Use a global object (which is already required to be unique over
3858 the program) rather than the file name (which imposes extra
3859 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
3860 sprintf (buf, FILE_FUNCTION_FORMAT, p);
3862 /* Don't need to pull wierd characters out of global names. */
3863 if (p != first_global_object_name)
3865 for (p = buf+11; *p; p++)
3866 if (! ((*p >= '0' && *p <= '9')
3867 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
3868 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
3872 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
3875 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
3878 || (*p >= 'A' && *p <= 'Z')
3879 || (*p >= 'a' && *p <= 'z')))
3883 buf[FILE_FUNCTION_PREFIX_LEN] = kind;
3885 return get_identifier (buf);