1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 1988, 1992 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. */
43 #define obstack_chunk_alloc xmalloc
44 #define obstack_chunk_free free
46 /* Tree nodes of permanent duration are allocated in this obstack.
47 They are the identifier nodes, and everything outside of
48 the bodies and parameters of function definitions. */
50 struct obstack permanent_obstack;
52 /* The initial RTL, and all ..._TYPE nodes, in a function
53 are allocated in this obstack. Usually they are freed at the
54 end of the function, but if the function is inline they are saved.
55 For top-level functions, this is maybepermanent_obstack.
56 Separate obstacks are made for nested functions. */
58 struct obstack *function_maybepermanent_obstack;
60 /* This is the function_maybepermanent_obstack for top-level functions. */
62 struct obstack maybepermanent_obstack;
64 /* The contents of the current function definition are allocated
65 in this obstack, and all are freed at the end of the function.
66 For top-level functions, this is temporary_obstack.
67 Separate obstacks are made for nested functions. */
69 struct obstack *function_obstack;
71 /* This is used for reading initializers of global variables. */
73 struct obstack temporary_obstack;
75 /* The tree nodes of an expression are allocated
76 in this obstack, and all are freed at the end of the expression. */
78 struct obstack momentary_obstack;
80 /* The tree nodes of a declarator are allocated
81 in this obstack, and all are freed when the declarator
84 static struct obstack temp_decl_obstack;
86 /* This points at either permanent_obstack
87 or the current function_maybepermanent_obstack. */
89 struct obstack *saveable_obstack;
91 /* This is same as saveable_obstack during parse and expansion phase;
92 it points to the current function's obstack during optimization.
93 This is the obstack to be used for creating rtl objects. */
95 struct obstack *rtl_obstack;
97 /* This points at either permanent_obstack or the current function_obstack. */
99 struct obstack *current_obstack;
101 /* This points at either permanent_obstack or the current function_obstack
102 or momentary_obstack. */
104 struct obstack *expression_obstack;
106 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
110 struct obstack_stack *next;
111 struct obstack *current;
112 struct obstack *saveable;
113 struct obstack *expression;
117 struct obstack_stack *obstack_stack;
119 /* Obstack for allocating struct obstack_stack entries. */
121 static struct obstack obstack_stack_obstack;
123 /* Addresses of first objects in some obstacks.
124 This is for freeing their entire contents. */
125 char *maybepermanent_firstobj;
126 char *temporary_firstobj;
127 char *momentary_firstobj;
128 char *temp_decl_firstobj;
130 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
132 int all_types_permanent;
134 /* Stack of places to restore the momentary obstack back to. */
136 struct momentary_level
138 /* Pointer back to previous such level. */
139 struct momentary_level *prev;
140 /* First object allocated within this level. */
142 /* Value of expression_obstack saved at entry to this level. */
143 struct obstack *obstack;
146 struct momentary_level *momentary_stack;
148 /* Table indexed by tree code giving a string containing a character
149 classifying the tree code. Possibilities are
150 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
152 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
154 char *standard_tree_code_type[] = {
159 /* Table indexed by tree code giving number of expression
160 operands beyond the fixed part of the node structure.
161 Not used for types or decls. */
163 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
165 int standard_tree_code_length[] = {
170 /* Names of tree components.
171 Used for printing out the tree and error messages. */
172 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
174 char *standard_tree_code_name[] = {
179 /* Table indexed by tree code giving a string containing a character
180 classifying the tree code. Possibilities are
181 t, d, s, c, r, e, <, 1 and 2. See tree.def for details. */
183 char **tree_code_type;
185 /* Table indexed by tree code giving number of expression
186 operands beyond the fixed part of the node structure.
187 Not used for types or decls. */
189 int *tree_code_length;
191 /* Table indexed by tree code giving name of tree code, as a string. */
193 char **tree_code_name;
195 /* Statistics-gathering stuff. */
216 int tree_node_counts[(int)all_kinds];
217 int tree_node_sizes[(int)all_kinds];
218 int id_string_size = 0;
220 char *tree_node_kind_names[] = {
238 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
240 #define MAX_HASH_TABLE 1009
241 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
243 /* 0 while creating built-in identifiers. */
244 static int do_identifier_warnings;
246 /* Unique id for next decl created. */
247 static int next_decl_uid;
249 extern char *mode_name[];
251 void gcc_obstack_init ();
252 static tree stabilize_reference_1 ();
254 /* Init the principal obstacks. */
259 gcc_obstack_init (&obstack_stack_obstack);
260 gcc_obstack_init (&permanent_obstack);
262 gcc_obstack_init (&temporary_obstack);
263 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
264 gcc_obstack_init (&momentary_obstack);
265 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
266 gcc_obstack_init (&maybepermanent_obstack);
267 maybepermanent_firstobj
268 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
269 gcc_obstack_init (&temp_decl_obstack);
270 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
272 function_obstack = &temporary_obstack;
273 function_maybepermanent_obstack = &maybepermanent_obstack;
274 current_obstack = &permanent_obstack;
275 expression_obstack = &permanent_obstack;
276 rtl_obstack = saveable_obstack = &permanent_obstack;
278 /* Init the hash table of identifiers. */
279 bzero (hash_table, sizeof hash_table);
283 gcc_obstack_init (obstack)
284 struct obstack *obstack;
286 /* Let particular systems override the size of a chunk. */
287 #ifndef OBSTACK_CHUNK_SIZE
288 #define OBSTACK_CHUNK_SIZE 0
290 /* Let them override the alloc and free routines too. */
291 #ifndef OBSTACK_CHUNK_ALLOC
292 #define OBSTACK_CHUNK_ALLOC xmalloc
294 #ifndef OBSTACK_CHUNK_FREE
295 #define OBSTACK_CHUNK_FREE free
297 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
298 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
299 (void (*) ()) OBSTACK_CHUNK_FREE);
302 /* Save all variables describing the current status into the structure *P.
303 This is used before starting a nested function. */
309 p->all_types_permanent = all_types_permanent;
310 p->momentary_stack = momentary_stack;
311 p->maybepermanent_firstobj = maybepermanent_firstobj;
312 p->momentary_firstobj = momentary_firstobj;
313 p->function_obstack = function_obstack;
314 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
315 p->current_obstack = current_obstack;
316 p->expression_obstack = expression_obstack;
317 p->saveable_obstack = saveable_obstack;
318 p->rtl_obstack = rtl_obstack;
320 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
321 gcc_obstack_init (function_obstack);
323 function_maybepermanent_obstack
324 = (struct obstack *) xmalloc (sizeof (struct obstack));
325 gcc_obstack_init (function_maybepermanent_obstack);
327 current_obstack = &permanent_obstack;
328 expression_obstack = &permanent_obstack;
329 rtl_obstack = saveable_obstack = &permanent_obstack;
331 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
332 maybepermanent_firstobj
333 = (char *) obstack_finish (function_maybepermanent_obstack);
336 /* Restore all variables describing the current status from the structure *P.
337 This is used after a nested function. */
340 restore_tree_status (p)
343 all_types_permanent = p->all_types_permanent;
344 momentary_stack = p->momentary_stack;
346 obstack_free (&momentary_obstack, momentary_firstobj);
347 obstack_free (function_obstack, 0);
348 obstack_free (function_maybepermanent_obstack, 0);
349 free (function_obstack);
351 momentary_firstobj = p->momentary_firstobj;
352 maybepermanent_firstobj = p->maybepermanent_firstobj;
353 function_obstack = p->function_obstack;
354 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
355 current_obstack = p->current_obstack;
356 expression_obstack = p->expression_obstack;
357 saveable_obstack = p->saveable_obstack;
358 rtl_obstack = p->rtl_obstack;
361 /* Start allocating on the temporary (per function) obstack.
362 This is done in start_function before parsing the function body,
363 and before each initialization at top level, and to go back
364 to temporary allocation after doing end_temporary_allocation. */
367 temporary_allocation ()
369 /* Note that function_obstack at top level points to temporary_obstack.
370 But within a nested function context, it is a separate obstack. */
371 current_obstack = function_obstack;
372 expression_obstack = function_obstack;
373 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
377 /* Start allocating on the permanent obstack but don't
378 free the temporary data. After calling this, call
379 `permanent_allocation' to fully resume permanent allocation status. */
382 end_temporary_allocation ()
384 current_obstack = &permanent_obstack;
385 expression_obstack = &permanent_obstack;
386 rtl_obstack = saveable_obstack = &permanent_obstack;
389 /* Resume allocating on the temporary obstack, undoing
390 effects of `end_temporary_allocation'. */
393 resume_temporary_allocation ()
395 current_obstack = function_obstack;
396 expression_obstack = function_obstack;
397 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
400 /* While doing temporary allocation, switch to allocating in such a
401 way as to save all nodes if the function is inlined. Call
402 resume_temporary_allocation to go back to ordinary temporary
406 saveable_allocation ()
408 /* Note that function_obstack at top level points to temporary_obstack.
409 But within a nested function context, it is a separate obstack. */
410 expression_obstack = current_obstack = saveable_obstack;
413 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
414 recording the previously current obstacks on a stack.
415 This does not free any storage in any obstack. */
418 push_obstacks (current, saveable)
419 struct obstack *current, *saveable;
421 struct obstack_stack *p
422 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
423 (sizeof (struct obstack_stack)));
425 p->current = current_obstack;
426 p->saveable = saveable_obstack;
427 p->expression = expression_obstack;
428 p->rtl = rtl_obstack;
429 p->next = obstack_stack;
432 current_obstack = current;
433 expression_obstack = current;
434 rtl_obstack = saveable_obstack = saveable;
437 /* Save the current set of obstacks, but don't change them. */
440 push_obstacks_nochange ()
442 struct obstack_stack *p
443 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
444 (sizeof (struct obstack_stack)));
446 p->current = current_obstack;
447 p->saveable = saveable_obstack;
448 p->expression = expression_obstack;
449 p->rtl = rtl_obstack;
450 p->next = obstack_stack;
454 /* Pop the obstack selection stack. */
459 struct obstack_stack *p = obstack_stack;
460 obstack_stack = p->next;
462 current_obstack = p->current;
463 saveable_obstack = p->saveable;
464 expression_obstack = p->expression;
465 rtl_obstack = p->rtl;
467 obstack_free (&obstack_stack_obstack, p);
470 /* Nonzero if temporary allocation is currently in effect.
471 Zero if currently doing permanent allocation. */
474 allocation_temporary_p ()
476 return current_obstack != &permanent_obstack;
479 /* Go back to allocating on the permanent obstack
480 and free everything in the temporary obstack.
481 This is done in finish_function after fully compiling a function. */
484 permanent_allocation ()
486 /* Free up previous temporary obstack data */
487 obstack_free (&temporary_obstack, temporary_firstobj);
488 obstack_free (&momentary_obstack, momentary_firstobj);
489 obstack_free (&maybepermanent_obstack, maybepermanent_firstobj);
490 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
492 current_obstack = &permanent_obstack;
493 expression_obstack = &permanent_obstack;
494 rtl_obstack = saveable_obstack = &permanent_obstack;
497 /* Save permanently everything on the maybepermanent_obstack. */
502 maybepermanent_firstobj
503 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
507 preserve_initializer ()
510 = (char *) obstack_alloc (&temporary_obstack, 0);
512 = (char *) obstack_alloc (&momentary_obstack, 0);
513 maybepermanent_firstobj
514 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
517 /* Start allocating new rtl in current_obstack.
518 Use resume_temporary_allocation
519 to go back to allocating rtl in saveable_obstack. */
522 rtl_in_current_obstack ()
524 rtl_obstack = current_obstack;
527 /* Temporarily allocate rtl from saveable_obstack. Return 1 if we were
528 previously allocating it from current_obstack. */
531 rtl_in_saveable_obstack ()
533 if (rtl_obstack == current_obstack)
535 rtl_obstack = saveable_obstack;
542 /* Allocate SIZE bytes in the current obstack
543 and return a pointer to them.
544 In practice the current obstack is always the temporary one. */
550 return (char *) obstack_alloc (current_obstack, size);
553 /* Free the object PTR in the current obstack
554 as well as everything allocated since PTR.
555 In practice the current obstack is always the temporary one. */
561 obstack_free (current_obstack, ptr);
564 /* Allocate SIZE bytes in the permanent obstack
565 and return a pointer to them. */
571 return (char *) obstack_alloc (&permanent_obstack, size);
574 /* Allocate NELEM items of SIZE bytes in the permanent obstack
575 and return a pointer to them. The storage is cleared before
576 returning the value. */
579 perm_calloc (nelem, size)
583 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
584 bzero (rval, nelem * size);
588 /* Allocate SIZE bytes in the saveable obstack
589 and return a pointer to them. */
595 return (char *) obstack_alloc (saveable_obstack, size);
598 /* Print out which obstack an object is in. */
601 debug_obstack (object)
604 struct obstack *obstack = NULL;
605 char *obstack_name = NULL;
608 for (p = outer_function_chain; p; p = p->next)
610 if (_obstack_allocated_p (p->function_obstack, object))
612 obstack = p->function_obstack;
613 obstack_name = "containing function obstack";
615 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
617 obstack = p->function_maybepermanent_obstack;
618 obstack_name = "containing function maybepermanent obstack";
622 if (_obstack_allocated_p (&obstack_stack_obstack, object))
624 obstack = &obstack_stack_obstack;
625 obstack_name = "obstack_stack_obstack";
627 else if (_obstack_allocated_p (function_obstack, object))
629 obstack = function_obstack;
630 obstack_name = "function obstack";
632 else if (_obstack_allocated_p (&permanent_obstack, object))
634 obstack = &permanent_obstack;
635 obstack_name = "permanent_obstack";
637 else if (_obstack_allocated_p (&momentary_obstack, object))
639 obstack = &momentary_obstack;
640 obstack_name = "momentary_obstack";
642 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
644 obstack = function_maybepermanent_obstack;
645 obstack_name = "function maybepermanent obstack";
647 else if (_obstack_allocated_p (&temp_decl_obstack, object))
649 obstack = &temp_decl_obstack;
650 obstack_name = "temp_decl_obstack";
653 /* Check to see if the object is in the free area of the obstack. */
656 if (object >= obstack->next_free
657 && object < obstack->chunk_limit)
658 fprintf (stderr, "object in free portion of obstack %s.\n",
661 fprintf (stderr, "object allocated from %s.\n", obstack_name);
664 fprintf (stderr, "object not allocated from any obstack.\n");
667 /* Return 1 if OBJ is in the permanent obstack.
668 This is slow, and should be used only for debugging.
669 Use TREE_PERMANENT for other purposes. */
672 object_permanent_p (obj)
675 return _obstack_allocated_p (&permanent_obstack, obj);
678 /* Start a level of momentary allocation.
679 In C, each compound statement has its own level
680 and that level is freed at the end of each statement.
681 All expression nodes are allocated in the momentary allocation level. */
686 struct momentary_level *tem
687 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
688 sizeof (struct momentary_level));
689 tem->prev = momentary_stack;
690 tem->base = (char *) obstack_base (&momentary_obstack);
691 tem->obstack = expression_obstack;
692 momentary_stack = tem;
693 expression_obstack = &momentary_obstack;
696 /* Free all the storage in the current momentary-allocation level.
697 In C, this happens at the end of each statement. */
702 obstack_free (&momentary_obstack, momentary_stack->base);
705 /* Discard a level of momentary allocation.
706 In C, this happens at the end of each compound statement.
707 Restore the status of expression node allocation
708 that was in effect before this level was created. */
713 struct momentary_level *tem = momentary_stack;
714 momentary_stack = tem->prev;
715 expression_obstack = tem->obstack;
716 obstack_free (&momentary_obstack, tem);
719 /* Call when starting to parse a declaration:
720 make expressions in the declaration last the length of the function.
721 Returns an argument that should be passed to resume_momentary later. */
726 register int tem = expression_obstack == &momentary_obstack;
727 expression_obstack = saveable_obstack;
731 /* Call when finished parsing a declaration:
732 restore the treatment of node-allocation that was
733 in effect before the suspension.
734 YES should be the value previously returned by suspend_momentary. */
737 resume_momentary (yes)
741 expression_obstack = &momentary_obstack;
744 /* Init the tables indexed by tree code.
745 Note that languages can add to these tables to define their own codes. */
750 tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type));
751 tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length));
752 tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name));
753 bcopy (standard_tree_code_type, tree_code_type,
754 sizeof (standard_tree_code_type));
755 bcopy (standard_tree_code_length, tree_code_length,
756 sizeof (standard_tree_code_length));
757 bcopy (standard_tree_code_name, tree_code_name,
758 sizeof (standard_tree_code_name));
761 /* Return a newly allocated node of code CODE.
762 Initialize the node's unique id and its TREE_PERMANENT flag.
763 For decl and type nodes, some other fields are initialized.
764 The rest of the node is initialized to zero.
766 Achoo! I got a code in the node. */
773 register int type = TREE_CODE_CLASS (code);
775 register struct obstack *obstack = current_obstack;
777 register tree_node_kind kind;
781 case 'd': /* A decl node */
782 #ifdef GATHER_STATISTICS
785 length = sizeof (struct tree_decl);
786 /* All decls in an inline function need to be saved. */
787 if (obstack != &permanent_obstack)
788 obstack = saveable_obstack;
789 /* PARM_DECLs always go on saveable_obstack, not permanent,
790 even though we may make them before the function turns
791 on temporary allocation. */
792 else if (code == PARM_DECL)
793 obstack = function_maybepermanent_obstack;
796 case 't': /* a type node */
797 #ifdef GATHER_STATISTICS
800 length = sizeof (struct tree_type);
801 /* All data types are put where we can preserve them if nec. */
802 if (obstack != &permanent_obstack)
803 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
806 case 'b': /* a lexical block */
807 #ifdef GATHER_STATISTICS
810 length = sizeof (struct tree_block);
811 /* All BLOCK nodes are put where we can preserve them if nec. */
812 if (obstack != &permanent_obstack)
813 obstack = saveable_obstack;
816 case 's': /* an expression with side effects */
817 #ifdef GATHER_STATISTICS
821 case 'r': /* a reference */
822 #ifdef GATHER_STATISTICS
826 case 'e': /* an expression */
827 case '<': /* a comparison expression */
828 case '1': /* a unary arithmetic expression */
829 case '2': /* a binary arithmetic expression */
830 #ifdef GATHER_STATISTICS
834 obstack = expression_obstack;
835 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
836 if (code == BIND_EXPR && obstack != &permanent_obstack)
837 obstack = saveable_obstack;
838 length = sizeof (struct tree_exp)
839 + (tree_code_length[(int) code] - 1) * sizeof (char *);
842 case 'c': /* a constant */
843 #ifdef GATHER_STATISTICS
846 obstack = expression_obstack;
848 /* We can't use tree_code_length for INTEGER_CST, since the number of
849 words is machine-dependent due to varying length of HOST_WIDE_INT,
850 which might be wider than a pointer (e.g., long long). Similarly
851 for REAL_CST, since the number of words is machine-dependent due
852 to varying size and alignment of `double'. */
854 if (code == INTEGER_CST)
855 length = sizeof (struct tree_int_cst);
856 else if (code == REAL_CST)
857 length = sizeof (struct tree_real_cst);
859 length = sizeof (struct tree_common)
860 + tree_code_length[(int) code] * sizeof (char *);
863 case 'x': /* something random, like an identifier. */
864 #ifdef GATHER_STATISTICS
865 if (code == IDENTIFIER_NODE)
867 else if (code == OP_IDENTIFIER)
869 else if (code == TREE_VEC)
874 length = sizeof (struct tree_common)
875 + tree_code_length[(int) code] * sizeof (char *);
876 /* Identifier nodes are always permanent since they are
877 unique in a compiler run. */
878 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
881 t = (tree) obstack_alloc (obstack, length);
883 #ifdef GATHER_STATISTICS
884 tree_node_counts[(int)kind]++;
885 tree_node_sizes[(int)kind] += length;
888 /* Clear a word at a time. */
889 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
891 /* Clear any extra bytes. */
892 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
895 TREE_SET_CODE (t, code);
896 if (obstack == &permanent_obstack)
897 TREE_PERMANENT (t) = 1;
902 TREE_SIDE_EFFECTS (t) = 1;
903 TREE_TYPE (t) = void_type_node;
907 if (code != FUNCTION_DECL)
909 DECL_IN_SYSTEM_HEADER (t)
910 = in_system_header && (obstack == &permanent_obstack);
911 DECL_SOURCE_LINE (t) = lineno;
912 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
913 DECL_UID (t) = next_decl_uid++;
918 static unsigned next_type_uid = 1;
920 TYPE_UID (t) = next_type_uid++;
923 TYPE_MAIN_VARIANT (t) = t;
927 TREE_CONSTANT (t) = 1;
934 /* Return a new node with the same contents as NODE
935 except that its TREE_CHAIN is zero and it has a fresh uid. */
942 register enum tree_code code = TREE_CODE (node);
946 switch (TREE_CODE_CLASS (code))
948 case 'd': /* A decl node */
949 length = sizeof (struct tree_decl);
952 case 't': /* a type node */
953 length = sizeof (struct tree_type);
956 case 'b': /* a lexical block node */
957 length = sizeof (struct tree_block);
960 case 'r': /* a reference */
961 case 'e': /* an expression */
962 case 's': /* an expression with side effects */
963 case '<': /* a comparison expression */
964 case '1': /* a unary arithmetic expression */
965 case '2': /* a binary arithmetic expression */
966 length = sizeof (struct tree_exp)
967 + (tree_code_length[(int) code] - 1) * sizeof (char *);
970 case 'c': /* a constant */
971 /* We can't use tree_code_length for this, since the number of words
972 is machine-dependent due to varying alignment of `double'. */
973 if (code == REAL_CST)
975 length = sizeof (struct tree_real_cst);
979 case 'x': /* something random, like an identifier. */
980 length = sizeof (struct tree_common)
981 + tree_code_length[(int) code] * sizeof (char *);
982 if (code == TREE_VEC)
983 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
986 t = (tree) obstack_alloc (current_obstack, length);
988 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
989 ((int *) t)[i] = ((int *) node)[i];
990 /* Clear any extra bytes. */
991 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
992 ((char *) t)[i] = ((char *) node)[i];
996 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1001 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1002 For example, this can copy a list made of TREE_LIST nodes. */
1009 register tree prev, next;
1014 head = prev = copy_node (list);
1015 next = TREE_CHAIN (list);
1018 TREE_CHAIN (prev) = copy_node (next);
1019 prev = TREE_CHAIN (prev);
1020 next = TREE_CHAIN (next);
1027 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1028 If an identifier with that name has previously been referred to,
1029 the same node is returned this time. */
1032 get_identifier (text)
1033 register char *text;
1038 register int len, hash_len;
1040 /* Compute length of text in len. */
1041 for (len = 0; text[len]; len++);
1043 /* Decide how much of that length to hash on */
1045 if (warn_id_clash && len > id_clash_len)
1046 hash_len = id_clash_len;
1048 /* Compute hash code */
1049 hi = hash_len * 613 + (unsigned)text[0];
1050 for (i = 1; i < hash_len; i += 2)
1051 hi = ((hi * 613) + (unsigned)(text[i]));
1053 hi &= (1 << HASHBITS) - 1;
1054 hi %= MAX_HASH_TABLE;
1056 /* Search table for identifier */
1057 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1058 if (IDENTIFIER_LENGTH (idp) == len
1059 && IDENTIFIER_POINTER (idp)[0] == text[0]
1060 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1061 return idp; /* <-- return if found */
1063 /* Not found; optionally warn about a similar identifier */
1064 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1065 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1066 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1068 warning ("`%s' and `%s' identical in first %d characters",
1069 IDENTIFIER_POINTER (idp), text, id_clash_len);
1073 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1074 abort (); /* set_identifier_size hasn't been called. */
1076 /* Not found, create one, add to chain */
1077 idp = make_node (IDENTIFIER_NODE);
1078 IDENTIFIER_LENGTH (idp) = len;
1079 #ifdef GATHER_STATISTICS
1080 id_string_size += len;
1083 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1085 TREE_CHAIN (idp) = hash_table[hi];
1086 hash_table[hi] = idp;
1087 return idp; /* <-- return if created */
1090 /* Enable warnings on similar identifiers (if requested).
1091 Done after the built-in identifiers are created. */
1094 start_identifier_warnings ()
1096 do_identifier_warnings = 1;
1099 /* Record the size of an identifier node for the language in use.
1100 SIZE is the total size in bytes.
1101 This is called by the language-specific files. This must be
1102 called before allocating any identifiers. */
1105 set_identifier_size (size)
1108 tree_code_length[(int) IDENTIFIER_NODE]
1109 = (size - sizeof (struct tree_common)) / sizeof (tree);
1112 /* Return a newly constructed INTEGER_CST node whose constant value
1113 is specified by the two ints LOW and HI.
1114 The TREE_TYPE is set to `int'.
1116 This function should be used via the `build_int_2' macro. */
1119 build_int_2_wide (low, hi)
1120 HOST_WIDE_INT low, hi;
1122 register tree t = make_node (INTEGER_CST);
1123 TREE_INT_CST_LOW (t) = low;
1124 TREE_INT_CST_HIGH (t) = hi;
1125 TREE_TYPE (t) = integer_type_node;
1129 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1132 build_real (type, d)
1138 /* Check for valid float value for this type on this target machine;
1139 if not, can print error message and store a valid value in D. */
1140 #ifdef CHECK_FLOAT_VALUE
1141 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1144 v = make_node (REAL_CST);
1145 TREE_TYPE (v) = type;
1146 TREE_REAL_CST (v) = d;
1150 /* Return a new REAL_CST node whose type is TYPE
1151 and whose value is the integer value of the INTEGER_CST node I. */
1153 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1156 real_value_from_int_cst (i)
1160 #ifdef REAL_ARITHMETIC
1161 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1162 #else /* not REAL_ARITHMETIC */
1163 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1165 d = (double) (~ TREE_INT_CST_HIGH (i));
1166 d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1167 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1168 d += (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1173 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1174 d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1175 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1176 d += (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1178 #endif /* not REAL_ARITHMETIC */
1182 /* This function can't be implemented if we can't do arithmetic
1183 on the float representation. */
1186 build_real_from_int_cst (type, i)
1193 v = make_node (REAL_CST);
1194 TREE_TYPE (v) = type;
1196 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type), real_value_from_int_cst (i));
1197 /* Check for valid float value for this type on this target machine;
1198 if not, can print error message and store a valid value in D. */
1199 #ifdef CHECK_FLOAT_VALUE
1200 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1203 TREE_REAL_CST (v) = d;
1207 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1209 /* Return a newly constructed STRING_CST node whose value is
1210 the LEN characters at STR.
1211 The TREE_TYPE is not initialized. */
1214 build_string (len, str)
1218 register tree s = make_node (STRING_CST);
1219 TREE_STRING_LENGTH (s) = len;
1220 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1224 /* Return a newly constructed COMPLEX_CST node whose value is
1225 specified by the real and imaginary parts REAL and IMAG.
1226 Both REAL and IMAG should be constant nodes.
1227 The TREE_TYPE is not initialized. */
1230 build_complex (real, imag)
1233 register tree t = make_node (COMPLEX_CST);
1234 TREE_REALPART (t) = real;
1235 TREE_IMAGPART (t) = imag;
1239 /* Build a newly constructed TREE_VEC node of length LEN. */
1245 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1246 register struct obstack *obstack = current_obstack;
1249 #ifdef GATHER_STATISTICS
1250 tree_node_counts[(int)vec_kind]++;
1251 tree_node_sizes[(int)vec_kind] += length;
1254 t = (tree) obstack_alloc (obstack, length);
1256 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1259 TREE_SET_CODE (t, TREE_VEC);
1260 TREE_VEC_LENGTH (t) = len;
1261 if (obstack == &permanent_obstack)
1262 TREE_PERMANENT (t) = 1;
1267 /* Return 1 if EXPR is the integer constant zero. */
1270 integer_zerop (expr)
1275 return (TREE_CODE (expr) == INTEGER_CST
1276 && TREE_INT_CST_LOW (expr) == 0
1277 && TREE_INT_CST_HIGH (expr) == 0);
1280 /* Return 1 if EXPR is the integer constant one. */
1288 return (TREE_CODE (expr) == INTEGER_CST
1289 && TREE_INT_CST_LOW (expr) == 1
1290 && TREE_INT_CST_HIGH (expr) == 0);
1293 /* Return 1 if EXPR is an integer containing all 1's
1294 in as much precision as it contains. */
1297 integer_all_onesp (expr)
1305 if (TREE_CODE (expr) != INTEGER_CST)
1308 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1310 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1312 prec = TYPE_PRECISION (TREE_TYPE (expr));
1313 if (prec >= HOST_BITS_PER_WIDE_INT)
1315 int high_value, shift_amount;
1317 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1319 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1320 /* Can not handle precisions greater than twice the host int size. */
1322 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1323 /* Shifting by the host word size is undefined according to the ANSI
1324 standard, so we must handle this as a special case. */
1327 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1329 return TREE_INT_CST_LOW (expr) == -1
1330 && TREE_INT_CST_HIGH (expr) == high_value;
1333 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1336 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1340 integer_pow2p (expr)
1343 HOST_WIDE_INT high, low;
1347 if (TREE_CODE (expr) != INTEGER_CST)
1350 high = TREE_INT_CST_HIGH (expr);
1351 low = TREE_INT_CST_LOW (expr);
1353 if (high == 0 && low == 0)
1356 return ((high == 0 && (low & (low - 1)) == 0)
1357 || (low == 0 && (high & (high - 1)) == 0));
1360 /* Return 1 if EXPR is the real constant zero. */
1368 return (TREE_CODE (expr) == REAL_CST
1369 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0));
1372 /* Return 1 if EXPR is the real constant one. */
1380 return (TREE_CODE (expr) == REAL_CST
1381 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1));
1384 /* Return 1 if EXPR is the real constant two. */
1392 return (TREE_CODE (expr) == REAL_CST
1393 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2));
1396 /* Nonzero if EXP is a constant or a cast of a constant. */
1399 really_constant_p (exp)
1402 /* This is not quite the same as STRIP_NOPS. It does more. */
1403 while (TREE_CODE (exp) == NOP_EXPR
1404 || TREE_CODE (exp) == CONVERT_EXPR
1405 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1406 exp = TREE_OPERAND (exp, 0);
1407 return TREE_CONSTANT (exp);
1410 /* Return first list element whose TREE_VALUE is ELEM.
1411 Return 0 if ELEM is not it LIST. */
1414 value_member (elem, list)
1419 if (elem == TREE_VALUE (list))
1421 list = TREE_CHAIN (list);
1426 /* Return first list element whose TREE_PURPOSE is ELEM.
1427 Return 0 if ELEM is not it LIST. */
1430 purpose_member (elem, list)
1435 if (elem == TREE_PURPOSE (list))
1437 list = TREE_CHAIN (list);
1442 /* Return first list element whose BINFO_TYPE is ELEM.
1443 Return 0 if ELEM is not it LIST. */
1446 binfo_member (elem, list)
1451 if (elem == BINFO_TYPE (list))
1453 list = TREE_CHAIN (list);
1458 /* Return nonzero if ELEM is part of the chain CHAIN. */
1461 chain_member (elem, chain)
1468 chain = TREE_CHAIN (chain);
1474 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1475 We expect a null pointer to mark the end of the chain.
1476 This is the Lisp primitive `length'. */
1483 register int len = 0;
1485 for (tail = t; tail; tail = TREE_CHAIN (tail))
1491 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1492 by modifying the last node in chain 1 to point to chain 2.
1493 This is the Lisp primitive `nconc'. */
1503 for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t))
1504 if (t == op2) abort (); /* Circularity being created */
1505 if (t == op2) abort (); /* Circularity being created */
1506 TREE_CHAIN (t) = op2;
1512 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1516 register tree chain;
1520 while (next = TREE_CHAIN (chain))
1525 /* Reverse the order of elements in the chain T,
1526 and return the new head of the chain (old last element). */
1532 register tree prev = 0, decl, next;
1533 for (decl = t; decl; decl = next)
1535 next = TREE_CHAIN (decl);
1536 TREE_CHAIN (decl) = prev;
1542 /* Given a chain CHAIN of tree nodes,
1543 construct and return a list of those nodes. */
1549 tree result = NULL_TREE;
1550 tree in_tail = chain;
1551 tree out_tail = NULL_TREE;
1555 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1557 TREE_CHAIN (out_tail) = next;
1561 in_tail = TREE_CHAIN (in_tail);
1567 /* Return a newly created TREE_LIST node whose
1568 purpose and value fields are PARM and VALUE. */
1571 build_tree_list (parm, value)
1574 register tree t = make_node (TREE_LIST);
1575 TREE_PURPOSE (t) = parm;
1576 TREE_VALUE (t) = value;
1580 /* Similar, but build on the temp_decl_obstack. */
1583 build_decl_list (parm, value)
1587 register struct obstack *ambient_obstack = current_obstack;
1588 current_obstack = &temp_decl_obstack;
1589 node = build_tree_list (parm, value);
1590 current_obstack = ambient_obstack;
1594 /* Return a newly created TREE_LIST node whose
1595 purpose and value fields are PARM and VALUE
1596 and whose TREE_CHAIN is CHAIN. */
1599 tree_cons (purpose, value, chain)
1600 tree purpose, value, chain;
1603 register tree node = make_node (TREE_LIST);
1606 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
1607 #ifdef GATHER_STATISTICS
1608 tree_node_counts[(int)x_kind]++;
1609 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
1612 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
1613 ((int *) node)[i] = 0;
1615 TREE_SET_CODE (node, TREE_LIST);
1616 if (current_obstack == &permanent_obstack)
1617 TREE_PERMANENT (node) = 1;
1620 TREE_CHAIN (node) = chain;
1621 TREE_PURPOSE (node) = purpose;
1622 TREE_VALUE (node) = value;
1626 /* Similar, but build on the temp_decl_obstack. */
1629 decl_tree_cons (purpose, value, chain)
1630 tree purpose, value, chain;
1633 register struct obstack *ambient_obstack = current_obstack;
1634 current_obstack = &temp_decl_obstack;
1635 node = tree_cons (purpose, value, chain);
1636 current_obstack = ambient_obstack;
1640 /* Same as `tree_cons' but make a permanent object. */
1643 perm_tree_cons (purpose, value, chain)
1644 tree purpose, value, chain;
1647 register struct obstack *ambient_obstack = current_obstack;
1648 current_obstack = &permanent_obstack;
1650 node = tree_cons (purpose, value, chain);
1651 current_obstack = ambient_obstack;
1655 /* Same as `tree_cons', but make this node temporary, regardless. */
1658 temp_tree_cons (purpose, value, chain)
1659 tree purpose, value, chain;
1662 register struct obstack *ambient_obstack = current_obstack;
1663 current_obstack = &temporary_obstack;
1665 node = tree_cons (purpose, value, chain);
1666 current_obstack = ambient_obstack;
1670 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
1673 saveable_tree_cons (purpose, value, chain)
1674 tree purpose, value, chain;
1677 register struct obstack *ambient_obstack = current_obstack;
1678 current_obstack = saveable_obstack;
1680 node = tree_cons (purpose, value, chain);
1681 current_obstack = ambient_obstack;
1685 /* Return the size nominally occupied by an object of type TYPE
1686 when it resides in memory. The value is measured in units of bytes,
1687 and its data type is that normally used for type sizes
1688 (which is the first type created by make_signed_type or
1689 make_unsigned_type). */
1692 size_in_bytes (type)
1697 if (type == error_mark_node)
1698 return integer_zero_node;
1699 type = TYPE_MAIN_VARIANT (type);
1700 if (TYPE_SIZE (type) == 0)
1702 incomplete_type_error (NULL_TREE, type);
1703 return integer_zero_node;
1705 t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1706 size_int (BITS_PER_UNIT));
1707 if (TREE_CODE (t) == INTEGER_CST)
1708 force_fit_type (t, 0);
1712 /* Return the size of TYPE (in bytes) as an integer,
1713 or return -1 if the size can vary. */
1716 int_size_in_bytes (type)
1720 if (type == error_mark_node)
1722 type = TYPE_MAIN_VARIANT (type);
1723 if (TYPE_SIZE (type) == 0)
1725 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1727 if (TREE_INT_CST_HIGH (TYPE_SIZE (type)) != 0)
1729 tree t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1730 size_int (BITS_PER_UNIT));
1731 return TREE_INT_CST_LOW (t);
1733 size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1734 return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1737 /* Return, as an INTEGER_CST node, the number of elements for
1738 TYPE (which is an ARRAY_TYPE) minus one.
1739 This counts only elements of the top array. */
1742 array_type_nelts (type)
1745 tree index_type = TYPE_DOMAIN (type);
1746 return (tree_int_cst_equal (TYPE_MIN_VALUE (index_type), integer_zero_node)
1747 ? TYPE_MAX_VALUE (index_type)
1748 : fold (build (MINUS_EXPR, integer_type_node,
1749 TYPE_MAX_VALUE (index_type),
1750 TYPE_MIN_VALUE (index_type))));
1753 /* Return nonzero if arg is static -- a reference to an object in
1754 static storage. This is not the same as the C meaning of `static'. */
1760 switch (TREE_CODE (arg))
1765 return TREE_STATIC (arg) || DECL_EXTERNAL (arg);
1772 return staticp (TREE_OPERAND (arg, 0));
1775 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
1778 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1779 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1780 return staticp (TREE_OPERAND (arg, 0));
1786 /* This should be applied to any node which may be used in more than one place,
1787 but must be evaluated only once. Normally, the code generator would
1788 reevaluate the node each time; this forces it to compute it once and save
1789 the result. This is done by encapsulating the node in a SAVE_EXPR. */
1795 register tree t = fold (expr);
1797 /* We don't care about whether this can be used as an lvalue in this
1799 while (TREE_CODE (t) == NON_LVALUE_EXPR)
1800 t = TREE_OPERAND (t, 0);
1802 /* If the tree evaluates to a constant, then we don't want to hide that
1803 fact (i.e. this allows further folding, and direct checks for constants).
1804 However, a read-only object that has side effects cannot be bypassed.
1805 Since it is no problem to reevaluate literals, we just return the
1808 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
1809 || TREE_CODE (t) == SAVE_EXPR)
1812 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
1814 /* This expression might be placed ahead of a jump to ensure that the
1815 value was computed on both sides of the jump. So make sure it isn't
1816 eliminated as dead. */
1817 TREE_SIDE_EFFECTS (t) = 1;
1821 /* Stabilize a reference so that we can use it any number of times
1822 without causing its operands to be evaluated more than once.
1823 Returns the stabilized reference.
1825 Also allows conversion expressions whose operands are references.
1826 Any other kind of expression is returned unchanged. */
1829 stabilize_reference (ref)
1832 register tree result;
1833 register enum tree_code code = TREE_CODE (ref);
1840 /* No action is needed in this case. */
1846 case FIX_TRUNC_EXPR:
1847 case FIX_FLOOR_EXPR:
1848 case FIX_ROUND_EXPR:
1850 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
1854 result = build_nt (INDIRECT_REF,
1855 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
1859 result = build_nt (COMPONENT_REF,
1860 stabilize_reference (TREE_OPERAND (ref, 0)),
1861 TREE_OPERAND (ref, 1));
1865 result = build_nt (BIT_FIELD_REF,
1866 stabilize_reference (TREE_OPERAND (ref, 0)),
1867 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
1868 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
1872 result = build_nt (ARRAY_REF,
1873 stabilize_reference (TREE_OPERAND (ref, 0)),
1874 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
1877 /* If arg isn't a kind of lvalue we recognize, make no change.
1878 Caller should recognize the error for an invalid lvalue. */
1883 return error_mark_node;
1886 TREE_TYPE (result) = TREE_TYPE (ref);
1887 TREE_READONLY (result) = TREE_READONLY (ref);
1888 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
1889 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
1890 TREE_RAISES (result) = TREE_RAISES (ref);
1895 /* Subroutine of stabilize_reference; this is called for subtrees of
1896 references. Any expression with side-effects must be put in a SAVE_EXPR
1897 to ensure that it is only evaluated once.
1899 We don't put SAVE_EXPR nodes around everything, because assigning very
1900 simple expressions to temporaries causes us to miss good opportunities
1901 for optimizations. Among other things, the opportunity to fold in the
1902 addition of a constant into an addressing mode often gets lost, e.g.
1903 "y[i+1] += x;". In general, we take the approach that we should not make
1904 an assignment unless we are forced into it - i.e., that any non-side effect
1905 operator should be allowed, and that cse should take care of coalescing
1906 multiple utterances of the same expression should that prove fruitful. */
1909 stabilize_reference_1 (e)
1912 register tree result;
1913 register int length;
1914 register enum tree_code code = TREE_CODE (e);
1916 /* We cannot ignore const expressions because it might be a reference
1917 to a const array but whose index contains side-effects. But we can
1918 ignore things that are actual constant or that already have been
1919 handled by this function. */
1921 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
1924 switch (TREE_CODE_CLASS (code))
1934 /* If the expression has side-effects, then encase it in a SAVE_EXPR
1935 so that it will only be evaluated once. */
1936 /* The reference (r) and comparison (<) classes could be handled as
1937 below, but it is generally faster to only evaluate them once. */
1938 if (TREE_SIDE_EFFECTS (e))
1939 return save_expr (e);
1943 /* Constants need no processing. In fact, we should never reach
1948 /* Recursively stabilize each operand. */
1949 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
1950 stabilize_reference_1 (TREE_OPERAND (e, 1)));
1954 /* Recursively stabilize each operand. */
1955 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
1959 TREE_TYPE (result) = TREE_TYPE (e);
1960 TREE_READONLY (result) = TREE_READONLY (e);
1961 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
1962 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
1963 TREE_RAISES (result) = TREE_RAISES (e);
1968 /* Low-level constructors for expressions. */
1970 /* Build an expression of code CODE, data type TYPE,
1971 and operands as specified by the arguments ARG1 and following arguments.
1972 Expressions and reference nodes can be created this way.
1973 Constants, decls, types and misc nodes cannot be. */
1980 enum tree_code code;
1982 register int length;
1987 code = va_arg (p, enum tree_code);
1988 t = make_node (code);
1989 length = tree_code_length[(int) code];
1990 TREE_TYPE (t) = va_arg (p, tree);
1994 /* This is equivalent to the loop below, but faster. */
1995 register tree arg0 = va_arg (p, tree);
1996 register tree arg1 = va_arg (p, tree);
1997 TREE_OPERAND (t, 0) = arg0;
1998 TREE_OPERAND (t, 1) = arg1;
1999 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
2000 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
2001 TREE_SIDE_EFFECTS (t) = 1;
2003 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
2005 else if (length == 1)
2007 register tree arg0 = va_arg (p, tree);
2009 /* Call build1 for this! */
2010 if (TREE_CODE_CLASS (code) != 's')
2012 TREE_OPERAND (t, 0) = arg0;
2013 if (arg0 && TREE_SIDE_EFFECTS (arg0))
2014 TREE_SIDE_EFFECTS (t) = 1;
2015 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
2019 for (i = 0; i < length; i++)
2021 register tree operand = va_arg (p, tree);
2022 TREE_OPERAND (t, i) = operand;
2025 if (TREE_SIDE_EFFECTS (operand))
2026 TREE_SIDE_EFFECTS (t) = 1;
2027 if (TREE_RAISES (operand))
2028 TREE_RAISES (t) = 1;
2036 /* Same as above, but only builds for unary operators.
2037 Saves lions share of calls to `build'; cuts down use
2038 of varargs, which is expensive for RISC machines. */
2040 build1 (code, type, node)
2041 enum tree_code code;
2045 register struct obstack *obstack = current_obstack;
2046 register int i, length;
2047 register tree_node_kind kind;
2050 #ifdef GATHER_STATISTICS
2051 if (TREE_CODE_CLASS (code) == 'r')
2057 obstack = expression_obstack;
2058 length = sizeof (struct tree_exp);
2060 t = (tree) obstack_alloc (obstack, length);
2062 #ifdef GATHER_STATISTICS
2063 tree_node_counts[(int)kind]++;
2064 tree_node_sizes[(int)kind] += length;
2067 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
2070 TREE_TYPE (t) = type;
2071 TREE_SET_CODE (t, code);
2073 if (obstack == &permanent_obstack)
2074 TREE_PERMANENT (t) = 1;
2076 TREE_OPERAND (t, 0) = node;
2079 if (TREE_SIDE_EFFECTS (node))
2080 TREE_SIDE_EFFECTS (t) = 1;
2081 if (TREE_RAISES (node))
2082 TREE_RAISES (t) = 1;
2088 /* Similar except don't specify the TREE_TYPE
2089 and leave the TREE_SIDE_EFFECTS as 0.
2090 It is permissible for arguments to be null,
2091 or even garbage if their values do not matter. */
2098 register enum tree_code code;
2100 register int length;
2105 code = va_arg (p, enum tree_code);
2106 t = make_node (code);
2107 length = tree_code_length[(int) code];
2109 for (i = 0; i < length; i++)
2110 TREE_OPERAND (t, i) = va_arg (p, tree);
2116 /* Similar to `build_nt', except we build
2117 on the temp_decl_obstack, regardless. */
2120 build_parse_node (va_alist)
2123 register struct obstack *ambient_obstack = expression_obstack;
2125 register enum tree_code code;
2127 register int length;
2130 expression_obstack = &temp_decl_obstack;
2134 code = va_arg (p, enum tree_code);
2135 t = make_node (code);
2136 length = tree_code_length[(int) code];
2138 for (i = 0; i < length; i++)
2139 TREE_OPERAND (t, i) = va_arg (p, tree);
2142 expression_obstack = ambient_obstack;
2147 /* Commented out because this wants to be done very
2148 differently. See cp-lex.c. */
2150 build_op_identifier (op1, op2)
2153 register tree t = make_node (OP_IDENTIFIER);
2154 TREE_PURPOSE (t) = op1;
2155 TREE_VALUE (t) = op2;
2160 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
2161 We do NOT enter this node in any sort of symbol table.
2163 layout_decl is used to set up the decl's storage layout.
2164 Other slots are initialized to 0 or null pointers. */
2167 build_decl (code, name, type)
2168 enum tree_code code;
2173 t = make_node (code);
2175 /* if (type == error_mark_node)
2176 type = integer_type_node; */
2177 /* That is not done, deliberately, so that having error_mark_node
2178 as the type can suppress useless errors in the use of this variable. */
2180 DECL_NAME (t) = name;
2181 DECL_ASSEMBLER_NAME (t) = name;
2182 TREE_TYPE (t) = type;
2184 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
2186 else if (code == FUNCTION_DECL)
2187 DECL_MODE (t) = FUNCTION_MODE;
2192 /* BLOCK nodes are used to represent the structure of binding contours
2193 and declarations, once those contours have been exited and their contents
2194 compiled. This information is used for outputting debugging info. */
2197 build_block (vars, tags, subblocks, supercontext, chain)
2198 tree vars, tags, subblocks, supercontext, chain;
2200 register tree block = make_node (BLOCK);
2201 BLOCK_VARS (block) = vars;
2202 BLOCK_TYPE_TAGS (block) = tags;
2203 BLOCK_SUBBLOCKS (block) = subblocks;
2204 BLOCK_SUPERCONTEXT (block) = supercontext;
2205 BLOCK_CHAIN (block) = chain;
2209 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
2210 and its TYPE_VOLATILE is VOLATILEP.
2212 Such variant types already made are recorded so that duplicates
2215 A variant types should never be used as the type of an expression.
2216 Always copy the variant information into the TREE_READONLY
2217 and TREE_THIS_VOLATILE of the expression, and then give the expression
2218 as its type the "main variant", the variant whose TYPE_READONLY
2219 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
2223 build_type_variant (type, constp, volatilep)
2225 int constp, volatilep;
2227 register tree t, m = TYPE_MAIN_VARIANT (type);
2228 register struct obstack *ambient_obstack = current_obstack;
2230 /* Treat any nonzero argument as 1. */
2232 volatilep = !!volatilep;
2234 /* If not generating auxiliary info, search the chain of variants to see
2235 if there is already one there just like the one we need to have. If so,
2236 use that existing one.
2238 We don't do this in the case where we are generating aux info because
2239 in that case we want each typedef names to get it's own distinct type
2240 node, even if the type of this new typedef is the same as some other
2243 if (!flag_gen_aux_info)
2244 for (t = m; t; t = TYPE_NEXT_VARIANT (t))
2245 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t))
2248 /* We need a new one. */
2250 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2252 t = copy_node (type);
2253 TYPE_READONLY (t) = constp;
2254 TYPE_VOLATILE (t) = volatilep;
2255 TYPE_POINTER_TO (t) = 0;
2256 TYPE_REFERENCE_TO (t) = 0;
2258 /* Add this type to the chain of variants of TYPE. */
2259 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2260 TYPE_NEXT_VARIANT (m) = t;
2262 current_obstack = ambient_obstack;
2266 /* Create a new variant of TYPE, equivalent but distinct.
2267 This is so the caller can modify it. */
2270 build_type_copy (type)
2273 register tree t, m = TYPE_MAIN_VARIANT (type);
2274 register struct obstack *ambient_obstack = current_obstack;
2277 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2279 t = copy_node (type);
2280 TYPE_POINTER_TO (t) = 0;
2281 TYPE_REFERENCE_TO (t) = 0;
2283 /* Add this type to the chain of variants of TYPE. */
2284 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2285 TYPE_NEXT_VARIANT (m) = t;
2287 current_obstack = ambient_obstack;
2291 /* Hashing of types so that we don't make duplicates.
2292 The entry point is `type_hash_canon'. */
2294 /* Each hash table slot is a bucket containing a chain
2295 of these structures. */
2299 struct type_hash *next; /* Next structure in the bucket. */
2300 int hashcode; /* Hash code of this type. */
2301 tree type; /* The type recorded here. */
2304 /* Now here is the hash table. When recording a type, it is added
2305 to the slot whose index is the hash code mod the table size.
2306 Note that the hash table is used for several kinds of types
2307 (function types, array types and array index range types, for now).
2308 While all these live in the same table, they are completely independent,
2309 and the hash code is computed differently for each of these. */
2311 #define TYPE_HASH_SIZE 59
2312 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
2314 /* Here is how primitive or already-canonicalized types' hash
2316 #define TYPE_HASH(TYPE) ((HOST_WIDE_INT) (TYPE) & 0777777)
2318 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
2319 with types in the TREE_VALUE slots), by adding the hash codes
2320 of the individual types. */
2323 type_hash_list (list)
2326 register int hashcode;
2328 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
2329 hashcode += TYPE_HASH (TREE_VALUE (tail));
2333 /* Look in the type hash table for a type isomorphic to TYPE.
2334 If one is found, return it. Otherwise return 0. */
2337 type_hash_lookup (hashcode, type)
2341 register struct type_hash *h;
2342 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
2343 if (h->hashcode == hashcode
2344 && TREE_CODE (h->type) == TREE_CODE (type)
2345 && TREE_TYPE (h->type) == TREE_TYPE (type)
2346 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
2347 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
2348 TYPE_MAX_VALUE (type)))
2349 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
2350 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
2351 TYPE_MIN_VALUE (type)))
2352 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
2353 || (TYPE_DOMAIN (h->type)
2354 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
2355 && TYPE_DOMAIN (type)
2356 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
2357 && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
2362 /* Add an entry to the type-hash-table
2363 for a type TYPE whose hash code is HASHCODE. */
2366 type_hash_add (hashcode, type)
2370 register struct type_hash *h;
2372 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
2373 h->hashcode = hashcode;
2375 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
2376 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
2379 /* Given TYPE, and HASHCODE its hash code, return the canonical
2380 object for an identical type if one already exists.
2381 Otherwise, return TYPE, and record it as the canonical object
2382 if it is a permanent object.
2384 To use this function, first create a type of the sort you want.
2385 Then compute its hash code from the fields of the type that
2386 make it different from other similar types.
2387 Then call this function and use the value.
2388 This function frees the type you pass in if it is a duplicate. */
2390 /* Set to 1 to debug without canonicalization. Never set by program. */
2391 int debug_no_type_hash = 0;
2394 type_hash_canon (hashcode, type)
2400 if (debug_no_type_hash)
2403 t1 = type_hash_lookup (hashcode, type);
2407 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2408 obstack_free (o, type);
2409 #ifdef GATHER_STATISTICS
2410 tree_node_counts[(int)t_kind]--;
2411 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
2416 /* If this is a new type, record it for later reuse. */
2417 if (current_obstack == &permanent_obstack)
2418 type_hash_add (hashcode, type);
2423 /* Given two lists of types
2424 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
2425 return 1 if the lists contain the same types in the same order.
2426 Also, the TREE_PURPOSEs must match. */
2429 type_list_equal (l1, l2)
2432 register tree t1, t2;
2433 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
2435 if (TREE_VALUE (t1) != TREE_VALUE (t2))
2437 if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2))
2439 int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
2450 /* Nonzero if integer constants T1 and T2
2451 represent the same constant value. */
2454 tree_int_cst_equal (t1, t2)
2459 if (t1 == 0 || t2 == 0)
2461 if (TREE_CODE (t1) == INTEGER_CST
2462 && TREE_CODE (t2) == INTEGER_CST
2463 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2464 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
2469 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
2470 The precise way of comparison depends on their data type. */
2473 tree_int_cst_lt (t1, t2)
2479 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
2480 return INT_CST_LT (t1, t2);
2481 return INT_CST_LT_UNSIGNED (t1, t2);
2484 /* Compare two constructor-element-type constants. */
2486 simple_cst_list_equal (l1, l2)
2489 while (l1 != NULL_TREE && l2 != NULL_TREE)
2491 int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2));
2496 l1 = TREE_CHAIN (l1);
2497 l2 = TREE_CHAIN (l2);
2502 /* Return truthvalue of whether T1 is the same tree structure as T2.
2503 Return 1 if they are the same.
2504 Return 0 if they are understandably different.
2505 Return -1 if either contains tree structure not understood by
2509 simple_cst_equal (t1, t2)
2512 register enum tree_code code1, code2;
2517 if (t1 == 0 || t2 == 0)
2520 code1 = TREE_CODE (t1);
2521 code2 = TREE_CODE (t2);
2523 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
2524 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
2525 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2527 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
2528 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
2529 || code2 == NON_LVALUE_EXPR)
2530 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
2538 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2539 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
2542 return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2545 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2546 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2547 TREE_STRING_LENGTH (t1));
2553 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2556 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2559 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2562 /* Special case: if either target is an unallocated VAR_DECL,
2563 it means that it's going to be unified with whatever the
2564 TARGET_EXPR is really supposed to initialize, so treat it
2565 as being equivalent to anything. */
2566 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
2567 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
2568 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
2569 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
2570 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
2571 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
2574 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2577 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2579 case WITH_CLEANUP_EXPR:
2580 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2583 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
2586 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
2587 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2597 /* This general rule works for most tree codes.
2598 All exceptions should be handled above. */
2600 switch (TREE_CODE_CLASS (code1))
2610 for (i=0; i<tree_code_length[(int) code1]; ++i)
2612 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
2622 /* Constructors for pointer, array and function types.
2623 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
2624 constructed by language-dependent code, not here.) */
2626 /* Construct, lay out and return the type of pointers to TO_TYPE.
2627 If such a type has already been constructed, reuse it. */
2630 build_pointer_type (to_type)
2633 register tree t = TYPE_POINTER_TO (to_type);
2634 register struct obstack *ambient_obstack = current_obstack;
2635 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2637 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2642 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2643 if (TREE_PERMANENT (to_type))
2645 current_obstack = &permanent_obstack;
2646 saveable_obstack = &permanent_obstack;
2649 t = make_node (POINTER_TYPE);
2650 TREE_TYPE (t) = to_type;
2652 /* Record this type as the pointer to TO_TYPE. */
2653 TYPE_POINTER_TO (to_type) = t;
2655 /* Lay out the type. This function has many callers that are concerned
2656 with expression-construction, and this simplifies them all.
2657 Also, it guarantees the TYPE_SIZE is permanent if the type is. */
2660 current_obstack = ambient_obstack;
2661 saveable_obstack = ambient_saveable_obstack;
2665 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
2666 MAXVAL should be the maximum value in the domain
2667 (one less than the length of the array). */
2670 build_index_type (maxval)
2673 register tree itype = make_node (INTEGER_TYPE);
2674 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2675 TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
2676 TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
2677 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
2678 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2679 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2680 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2681 if (TREE_CODE (maxval) == INTEGER_CST)
2683 int maxint = (int) TREE_INT_CST_LOW (maxval);
2684 /* If the domain should be empty, make sure the maxval
2685 remains -1 and is not spoiled by truncation. */
2686 if (INT_CST_LT (maxval, integer_zero_node))
2688 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
2689 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
2691 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
2697 /* Just like build_index_type, but takes lowval and highval instead
2698 of just highval (maxval). */
2701 build_index_2_type (lowval,highval)
2702 tree lowval, highval;
2704 register tree itype = make_node (INTEGER_TYPE);
2705 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2706 TYPE_MIN_VALUE (itype) = convert (sizetype, lowval);
2707 TYPE_MAX_VALUE (itype) = convert (sizetype, highval);
2708 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2709 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2710 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2711 if ((TREE_CODE (lowval) == INTEGER_CST)
2712 && (TREE_CODE (highval) == INTEGER_CST))
2714 HOST_WIDE_INT highint = TREE_INT_CST_LOW (highval);
2715 HOST_WIDE_INT lowint = TREE_INT_CST_LOW (lowval);
2716 int maxint = (int) (highint - lowint);
2717 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
2723 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
2724 Needed because when index types are not hashed, equal index types
2725 built at different times appear distinct, even though structurally,
2729 index_type_equal (itype1, itype2)
2730 tree itype1, itype2;
2732 if (TREE_CODE (itype1) != TREE_CODE (itype2))
2734 if (TREE_CODE (itype1) == INTEGER_TYPE)
2736 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
2737 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
2738 || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2))
2739 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
2741 if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2))
2742 && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2)))
2748 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
2749 and number of elements specified by the range of values of INDEX_TYPE.
2750 If such a type has already been constructed, reuse it. */
2753 build_array_type (elt_type, index_type)
2754 tree elt_type, index_type;
2759 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
2761 error ("arrays of functions are not meaningful");
2762 elt_type = integer_type_node;
2765 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
2766 build_pointer_type (elt_type);
2768 /* Allocate the array after the pointer type,
2769 in case we free it in type_hash_canon. */
2770 t = make_node (ARRAY_TYPE);
2771 TREE_TYPE (t) = elt_type;
2772 TYPE_DOMAIN (t) = index_type;
2774 if (index_type == 0)
2777 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
2778 t = type_hash_canon (hashcode, t);
2780 if (TYPE_SIZE (t) == 0)
2785 /* Construct, lay out and return
2786 the type of functions returning type VALUE_TYPE
2787 given arguments of types ARG_TYPES.
2788 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
2789 are data type nodes for the arguments of the function.
2790 If such a type has already been constructed, reuse it. */
2793 build_function_type (value_type, arg_types)
2794 tree value_type, arg_types;
2799 if (TREE_CODE (value_type) == FUNCTION_TYPE
2800 || TREE_CODE (value_type) == ARRAY_TYPE)
2802 error ("function return type cannot be function or array");
2803 value_type = integer_type_node;
2806 /* Make a node of the sort we want. */
2807 t = make_node (FUNCTION_TYPE);
2808 TREE_TYPE (t) = value_type;
2809 TYPE_ARG_TYPES (t) = arg_types;
2811 /* If we already have such a type, use the old one and free this one. */
2812 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
2813 t = type_hash_canon (hashcode, t);
2815 if (TYPE_SIZE (t) == 0)
2820 /* Build the node for the type of references-to-TO_TYPE. */
2823 build_reference_type (to_type)
2826 register tree t = TYPE_REFERENCE_TO (to_type);
2827 register struct obstack *ambient_obstack = current_obstack;
2828 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2830 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2835 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2836 if (TREE_PERMANENT (to_type))
2838 current_obstack = &permanent_obstack;
2839 saveable_obstack = &permanent_obstack;
2842 t = make_node (REFERENCE_TYPE);
2843 TREE_TYPE (t) = to_type;
2845 /* Record this type as the pointer to TO_TYPE. */
2846 TYPE_REFERENCE_TO (to_type) = t;
2850 current_obstack = ambient_obstack;
2851 saveable_obstack = ambient_saveable_obstack;
2855 /* Construct, lay out and return the type of methods belonging to class
2856 BASETYPE and whose arguments and values are described by TYPE.
2857 If that type exists already, reuse it.
2858 TYPE must be a FUNCTION_TYPE node. */
2861 build_method_type (basetype, type)
2862 tree basetype, type;
2867 /* Make a node of the sort we want. */
2868 t = make_node (METHOD_TYPE);
2870 if (TREE_CODE (type) != FUNCTION_TYPE)
2873 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2874 TREE_TYPE (t) = TREE_TYPE (type);
2876 /* The actual arglist for this function includes a "hidden" argument
2877 which is "this". Put it into the list of argument types. */
2880 = tree_cons (NULL_TREE,
2881 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
2883 /* If we already have such a type, use the old one and free this one. */
2884 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2885 t = type_hash_canon (hashcode, t);
2887 if (TYPE_SIZE (t) == 0)
2893 /* Construct, lay out and return the type of offsets to a value
2894 of type TYPE, within an object of type BASETYPE.
2895 If a suitable offset type exists already, reuse it. */
2898 build_offset_type (basetype, type)
2899 tree basetype, type;
2904 /* Make a node of the sort we want. */
2905 t = make_node (OFFSET_TYPE);
2907 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2908 TREE_TYPE (t) = type;
2910 /* If we already have such a type, use the old one and free this one. */
2911 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2912 t = type_hash_canon (hashcode, t);
2914 if (TYPE_SIZE (t) == 0)
2920 /* Create a complex type whose components are COMPONENT_TYPE. */
2923 build_complex_type (component_type)
2924 tree component_type;
2929 /* Make a node of the sort we want. */
2930 t = make_node (COMPLEX_TYPE);
2932 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
2933 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
2934 TYPE_READONLY (t) = TYPE_READONLY (component_type);
2936 /* If we already have such a type, use the old one and free this one. */
2937 hashcode = TYPE_HASH (component_type);
2938 t = type_hash_canon (hashcode, t);
2940 if (TYPE_SIZE (t) == 0)
2946 /* Return OP, stripped of any conversions to wider types as much as is safe.
2947 Converting the value back to OP's type makes a value equivalent to OP.
2949 If FOR_TYPE is nonzero, we return a value which, if converted to
2950 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
2952 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
2953 narrowest type that can hold the value, even if they don't exactly fit.
2954 Otherwise, bit-field references are changed to a narrower type
2955 only if they can be fetched directly from memory in that type.
2957 OP must have integer, real or enumeral type. Pointers are not allowed!
2959 There are some cases where the obvious value we could return
2960 would regenerate to OP if converted to OP's type,
2961 but would not extend like OP to wider types.
2962 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
2963 For example, if OP is (unsigned short)(signed char)-1,
2964 we avoid returning (signed char)-1 if FOR_TYPE is int,
2965 even though extending that to an unsigned short would regenerate OP,
2966 since the result of extending (signed char)-1 to (int)
2967 is different from (int) OP. */
2970 get_unwidened (op, for_type)
2974 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
2975 /* TYPE_PRECISION is safe in place of type_precision since
2976 pointer types are not allowed. */
2977 register tree type = TREE_TYPE (op);
2978 register unsigned final_prec
2979 = TYPE_PRECISION (for_type != 0 ? for_type : type);
2981 = (for_type != 0 && for_type != type
2982 && final_prec > TYPE_PRECISION (type)
2983 && TREE_UNSIGNED (type));
2984 register tree win = op;
2986 while (TREE_CODE (op) == NOP_EXPR)
2988 register int bitschange
2989 = TYPE_PRECISION (TREE_TYPE (op))
2990 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
2992 /* Truncations are many-one so cannot be removed.
2993 Unless we are later going to truncate down even farther. */
2995 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
2998 /* See what's inside this conversion. If we decide to strip it,
3000 op = TREE_OPERAND (op, 0);
3002 /* If we have not stripped any zero-extensions (uns is 0),
3003 we can strip any kind of extension.
3004 If we have previously stripped a zero-extension,
3005 only zero-extensions can safely be stripped.
3006 Any extension can be stripped if the bits it would produce
3007 are all going to be discarded later by truncating to FOR_TYPE. */
3011 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
3013 /* TREE_UNSIGNED says whether this is a zero-extension.
3014 Let's avoid computing it if it does not affect WIN
3015 and if UNS will not be needed again. */
3016 if ((uns || TREE_CODE (op) == NOP_EXPR)
3017 && TREE_UNSIGNED (TREE_TYPE (op)))
3025 if (TREE_CODE (op) == COMPONENT_REF
3026 /* Since type_for_size always gives an integer type. */
3027 && TREE_CODE (type) != REAL_TYPE)
3029 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3030 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
3032 /* We can get this structure field in the narrowest type it fits in.
3033 If FOR_TYPE is 0, do this only for a field that matches the
3034 narrower type exactly and is aligned for it
3035 The resulting extension to its nominal type (a fullword type)
3036 must fit the same conditions as for other extensions. */
3038 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3039 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
3040 && (! uns || final_prec <= innerprec
3041 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3044 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3045 TREE_OPERAND (op, 1));
3046 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3047 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3048 TREE_RAISES (win) = TREE_RAISES (op);
3054 /* Return OP or a simpler expression for a narrower value
3055 which can be sign-extended or zero-extended to give back OP.
3056 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
3057 or 0 if the value should be sign-extended. */
3060 get_narrower (op, unsignedp_ptr)
3064 register int uns = 0;
3066 register tree win = op;
3068 while (TREE_CODE (op) == NOP_EXPR)
3070 register int bitschange
3071 = TYPE_PRECISION (TREE_TYPE (op))
3072 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3074 /* Truncations are many-one so cannot be removed. */
3078 /* See what's inside this conversion. If we decide to strip it,
3080 op = TREE_OPERAND (op, 0);
3084 /* An extension: the outermost one can be stripped,
3085 but remember whether it is zero or sign extension. */
3087 uns = TREE_UNSIGNED (TREE_TYPE (op));
3088 /* Otherwise, if a sign extension has been stripped,
3089 only sign extensions can now be stripped;
3090 if a zero extension has been stripped, only zero-extensions. */
3091 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
3095 /* A change in nominal type can always be stripped. */
3100 if (TREE_CODE (op) == COMPONENT_REF
3101 /* Since type_for_size always gives an integer type. */
3102 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
3104 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3105 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
3107 /* We can get this structure field in a narrower type that fits it,
3108 but the resulting extension to its nominal type (a fullword type)
3109 must satisfy the same conditions as for other extensions.
3111 Do this only for fields that are aligned (not bit-fields),
3112 because when bit-field insns will be used there is no
3113 advantage in doing this. */
3115 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3116 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
3117 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3121 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
3122 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3123 TREE_OPERAND (op, 1));
3124 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3125 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3126 TREE_RAISES (win) = TREE_RAISES (op);
3129 *unsignedp_ptr = uns;
3133 /* Return the precision of a type, for arithmetic purposes.
3134 Supports all types on which arithmetic is possible
3135 (including pointer types).
3136 It's not clear yet what will be right for complex types. */
3139 type_precision (type)
3142 return ((TREE_CODE (type) == INTEGER_TYPE
3143 || TREE_CODE (type) == ENUMERAL_TYPE
3144 || TREE_CODE (type) == REAL_TYPE)
3145 ? TYPE_PRECISION (type) : POINTER_SIZE);
3148 /* Nonzero if integer constant C has a value that is permissible
3149 for type TYPE (an INTEGER_TYPE). */
3152 int_fits_type_p (c, type)
3155 if (TREE_UNSIGNED (type))
3156 return (!INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c)
3157 && !INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type))
3158 && (TREE_INT_CST_HIGH (c) >= 0 || TREE_UNSIGNED (TREE_TYPE (c))));
3160 return (!INT_CST_LT (TYPE_MAX_VALUE (type), c)
3161 && !INT_CST_LT (c, TYPE_MIN_VALUE (type))
3162 && (TREE_INT_CST_HIGH (c) >= 0 || !TREE_UNSIGNED (TREE_TYPE (c))));
3165 /* Return the innermost context enclosing DECL that is
3166 a FUNCTION_DECL, or zero if none. */
3169 decl_function_context (decl)
3174 if (TREE_CODE (decl) == ERROR_MARK)
3177 if (TREE_CODE (decl) == SAVE_EXPR)
3178 context = SAVE_EXPR_CONTEXT (decl);
3180 context = DECL_CONTEXT (decl);
3182 while (context && TREE_CODE (context) != FUNCTION_DECL)
3184 if (TREE_CODE (context) == RECORD_TYPE
3185 || TREE_CODE (context) == UNION_TYPE)
3186 context = TYPE_CONTEXT (context);
3187 else if (TREE_CODE (context) == TYPE_DECL)
3188 context = DECL_CONTEXT (context);
3189 else if (TREE_CODE (context) == BLOCK)
3190 context = BLOCK_SUPERCONTEXT (context);
3192 /* Unhandled CONTEXT !? */
3199 /* Return the innermost context enclosing DECL that is
3200 a RECORD_TYPE or UNION_TYPE, or zero if none.
3201 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
3204 decl_type_context (decl)
3207 tree context = DECL_CONTEXT (decl);
3211 if (TREE_CODE (context) == RECORD_TYPE
3212 || TREE_CODE (context) == UNION_TYPE)
3214 if (TREE_CODE (context) == TYPE_DECL
3215 || TREE_CODE (context) == FUNCTION_DECL)
3216 context = DECL_CONTEXT (context);
3217 else if (TREE_CODE (context) == BLOCK)
3218 context = BLOCK_SUPERCONTEXT (context);
3220 /* Unhandled CONTEXT!? */
3227 print_obstack_statistics (str, o)
3231 struct _obstack_chunk *chunk = o->chunk;
3238 n_alloc += chunk->limit - &chunk->contents[0];
3239 chunk = chunk->prev;
3241 fprintf (stderr, "obstack %s: %d bytes, %d chunks\n",
3242 str, n_alloc, n_chunks);
3245 dump_tree_statistics ()
3248 int total_nodes, total_bytes;
3250 fprintf (stderr, "\n??? tree nodes created\n\n");
3251 #ifdef GATHER_STATISTICS
3252 fprintf (stderr, "Kind Nodes Bytes\n");
3253 fprintf (stderr, "-------------------------------------\n");
3254 total_nodes = total_bytes = 0;
3255 for (i = 0; i < (int) all_kinds; i++)
3257 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
3258 tree_node_counts[i], tree_node_sizes[i]);
3259 total_nodes += tree_node_counts[i];
3260 total_bytes += tree_node_sizes[i];
3262 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
3263 fprintf (stderr, "-------------------------------------\n");
3264 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
3265 fprintf (stderr, "-------------------------------------\n");
3267 fprintf (stderr, "(No per-node statistics)\n");
3269 print_lang_statistics ();