1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 1988, 1992, 1993 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;
248 /* Unique id for next type created. */
249 static int next_type_uid = 1;
251 extern char *mode_name[];
253 void gcc_obstack_init ();
254 static tree stabilize_reference_1 ();
256 /* Init the principal obstacks. */
261 gcc_obstack_init (&obstack_stack_obstack);
262 gcc_obstack_init (&permanent_obstack);
264 gcc_obstack_init (&temporary_obstack);
265 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
266 gcc_obstack_init (&momentary_obstack);
267 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
268 gcc_obstack_init (&maybepermanent_obstack);
269 maybepermanent_firstobj
270 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
271 gcc_obstack_init (&temp_decl_obstack);
272 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
274 function_obstack = &temporary_obstack;
275 function_maybepermanent_obstack = &maybepermanent_obstack;
276 current_obstack = &permanent_obstack;
277 expression_obstack = &permanent_obstack;
278 rtl_obstack = saveable_obstack = &permanent_obstack;
280 /* Init the hash table of identifiers. */
281 bzero (hash_table, sizeof hash_table);
285 gcc_obstack_init (obstack)
286 struct obstack *obstack;
288 /* Let particular systems override the size of a chunk. */
289 #ifndef OBSTACK_CHUNK_SIZE
290 #define OBSTACK_CHUNK_SIZE 0
292 /* Let them override the alloc and free routines too. */
293 #ifndef OBSTACK_CHUNK_ALLOC
294 #define OBSTACK_CHUNK_ALLOC xmalloc
296 #ifndef OBSTACK_CHUNK_FREE
297 #define OBSTACK_CHUNK_FREE free
299 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
300 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
301 (void (*) ()) OBSTACK_CHUNK_FREE);
304 /* Save all variables describing the current status into the structure *P.
305 This is used before starting a nested function. */
311 p->all_types_permanent = all_types_permanent;
312 p->momentary_stack = momentary_stack;
313 p->maybepermanent_firstobj = maybepermanent_firstobj;
314 p->momentary_firstobj = momentary_firstobj;
315 p->function_obstack = function_obstack;
316 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
317 p->current_obstack = current_obstack;
318 p->expression_obstack = expression_obstack;
319 p->saveable_obstack = saveable_obstack;
320 p->rtl_obstack = rtl_obstack;
322 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
323 gcc_obstack_init (function_obstack);
325 function_maybepermanent_obstack
326 = (struct obstack *) xmalloc (sizeof (struct obstack));
327 gcc_obstack_init (function_maybepermanent_obstack);
329 current_obstack = &permanent_obstack;
330 expression_obstack = &permanent_obstack;
331 rtl_obstack = saveable_obstack = &permanent_obstack;
333 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
334 maybepermanent_firstobj
335 = (char *) obstack_finish (function_maybepermanent_obstack);
338 /* Restore all variables describing the current status from the structure *P.
339 This is used after a nested function. */
342 restore_tree_status (p)
345 all_types_permanent = p->all_types_permanent;
346 momentary_stack = p->momentary_stack;
348 obstack_free (&momentary_obstack, momentary_firstobj);
349 obstack_free (function_obstack, 0);
350 obstack_free (function_maybepermanent_obstack, 0);
351 free (function_obstack);
353 momentary_firstobj = p->momentary_firstobj;
354 maybepermanent_firstobj = p->maybepermanent_firstobj;
355 function_obstack = p->function_obstack;
356 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
357 current_obstack = p->current_obstack;
358 expression_obstack = p->expression_obstack;
359 saveable_obstack = p->saveable_obstack;
360 rtl_obstack = p->rtl_obstack;
363 /* Start allocating on the temporary (per function) obstack.
364 This is done in start_function before parsing the function body,
365 and before each initialization at top level, and to go back
366 to temporary allocation after doing end_temporary_allocation. */
369 temporary_allocation ()
371 /* Note that function_obstack at top level points to temporary_obstack.
372 But within a nested function context, it is a separate obstack. */
373 current_obstack = function_obstack;
374 expression_obstack = function_obstack;
375 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
379 /* Start allocating on the permanent obstack but don't
380 free the temporary data. After calling this, call
381 `permanent_allocation' to fully resume permanent allocation status. */
384 end_temporary_allocation ()
386 current_obstack = &permanent_obstack;
387 expression_obstack = &permanent_obstack;
388 rtl_obstack = saveable_obstack = &permanent_obstack;
391 /* Resume allocating on the temporary obstack, undoing
392 effects of `end_temporary_allocation'. */
395 resume_temporary_allocation ()
397 current_obstack = function_obstack;
398 expression_obstack = function_obstack;
399 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
402 /* While doing temporary allocation, switch to allocating in such a
403 way as to save all nodes if the function is inlined. Call
404 resume_temporary_allocation to go back to ordinary temporary
408 saveable_allocation ()
410 /* Note that function_obstack at top level points to temporary_obstack.
411 But within a nested function context, it is a separate obstack. */
412 expression_obstack = current_obstack = saveable_obstack;
415 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
416 recording the previously current obstacks on a stack.
417 This does not free any storage in any obstack. */
420 push_obstacks (current, saveable)
421 struct obstack *current, *saveable;
423 struct obstack_stack *p
424 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
425 (sizeof (struct obstack_stack)));
427 p->current = current_obstack;
428 p->saveable = saveable_obstack;
429 p->expression = expression_obstack;
430 p->rtl = rtl_obstack;
431 p->next = obstack_stack;
434 current_obstack = current;
435 expression_obstack = current;
436 rtl_obstack = saveable_obstack = saveable;
439 /* Save the current set of obstacks, but don't change them. */
442 push_obstacks_nochange ()
444 struct obstack_stack *p
445 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
446 (sizeof (struct obstack_stack)));
448 p->current = current_obstack;
449 p->saveable = saveable_obstack;
450 p->expression = expression_obstack;
451 p->rtl = rtl_obstack;
452 p->next = obstack_stack;
456 /* Pop the obstack selection stack. */
461 struct obstack_stack *p = obstack_stack;
462 obstack_stack = p->next;
464 current_obstack = p->current;
465 saveable_obstack = p->saveable;
466 expression_obstack = p->expression;
467 rtl_obstack = p->rtl;
469 obstack_free (&obstack_stack_obstack, p);
472 /* Nonzero if temporary allocation is currently in effect.
473 Zero if currently doing permanent allocation. */
476 allocation_temporary_p ()
478 return current_obstack != &permanent_obstack;
481 /* Go back to allocating on the permanent obstack
482 and free everything in the temporary obstack.
483 This is done in finish_function after fully compiling a function. */
486 permanent_allocation ()
488 /* Free up previous temporary obstack data */
489 obstack_free (&temporary_obstack, temporary_firstobj);
490 obstack_free (&momentary_obstack, momentary_firstobj);
491 obstack_free (&maybepermanent_obstack, maybepermanent_firstobj);
492 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
494 current_obstack = &permanent_obstack;
495 expression_obstack = &permanent_obstack;
496 rtl_obstack = saveable_obstack = &permanent_obstack;
499 /* Save permanently everything on the maybepermanent_obstack. */
504 maybepermanent_firstobj
505 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
509 preserve_initializer ()
512 = (char *) obstack_alloc (&temporary_obstack, 0);
514 = (char *) obstack_alloc (&momentary_obstack, 0);
515 maybepermanent_firstobj
516 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
519 /* Start allocating new rtl in current_obstack.
520 Use resume_temporary_allocation
521 to go back to allocating rtl in saveable_obstack. */
524 rtl_in_current_obstack ()
526 rtl_obstack = current_obstack;
529 /* Start allocating rtl from saveable_obstack. Intended to be used after
530 a call to push_obstacks_nochange. */
533 rtl_in_saveable_obstack ()
535 rtl_obstack = saveable_obstack;
538 /* Allocate SIZE bytes in the current obstack
539 and return a pointer to them.
540 In practice the current obstack is always the temporary one. */
546 return (char *) obstack_alloc (current_obstack, size);
549 /* Free the object PTR in the current obstack
550 as well as everything allocated since PTR.
551 In practice the current obstack is always the temporary one. */
557 obstack_free (current_obstack, ptr);
560 /* Allocate SIZE bytes in the permanent obstack
561 and return a pointer to them. */
567 return (char *) obstack_alloc (&permanent_obstack, size);
570 /* Allocate NELEM items of SIZE bytes in the permanent obstack
571 and return a pointer to them. The storage is cleared before
572 returning the value. */
575 perm_calloc (nelem, size)
579 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
580 bzero (rval, nelem * size);
584 /* Allocate SIZE bytes in the saveable obstack
585 and return a pointer to them. */
591 return (char *) obstack_alloc (saveable_obstack, size);
594 /* Print out which obstack an object is in. */
597 debug_obstack (object)
600 struct obstack *obstack = NULL;
601 char *obstack_name = NULL;
604 for (p = outer_function_chain; p; p = p->next)
606 if (_obstack_allocated_p (p->function_obstack, object))
608 obstack = p->function_obstack;
609 obstack_name = "containing function obstack";
611 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
613 obstack = p->function_maybepermanent_obstack;
614 obstack_name = "containing function maybepermanent obstack";
618 if (_obstack_allocated_p (&obstack_stack_obstack, object))
620 obstack = &obstack_stack_obstack;
621 obstack_name = "obstack_stack_obstack";
623 else if (_obstack_allocated_p (function_obstack, object))
625 obstack = function_obstack;
626 obstack_name = "function obstack";
628 else if (_obstack_allocated_p (&permanent_obstack, object))
630 obstack = &permanent_obstack;
631 obstack_name = "permanent_obstack";
633 else if (_obstack_allocated_p (&momentary_obstack, object))
635 obstack = &momentary_obstack;
636 obstack_name = "momentary_obstack";
638 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
640 obstack = function_maybepermanent_obstack;
641 obstack_name = "function maybepermanent obstack";
643 else if (_obstack_allocated_p (&temp_decl_obstack, object))
645 obstack = &temp_decl_obstack;
646 obstack_name = "temp_decl_obstack";
649 /* Check to see if the object is in the free area of the obstack. */
652 if (object >= obstack->next_free
653 && object < obstack->chunk_limit)
654 fprintf (stderr, "object in free portion of obstack %s.\n",
657 fprintf (stderr, "object allocated from %s.\n", obstack_name);
660 fprintf (stderr, "object not allocated from any obstack.\n");
663 /* Return 1 if OBJ is in the permanent obstack.
664 This is slow, and should be used only for debugging.
665 Use TREE_PERMANENT for other purposes. */
668 object_permanent_p (obj)
671 return _obstack_allocated_p (&permanent_obstack, obj);
674 /* Start a level of momentary allocation.
675 In C, each compound statement has its own level
676 and that level is freed at the end of each statement.
677 All expression nodes are allocated in the momentary allocation level. */
682 struct momentary_level *tem
683 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
684 sizeof (struct momentary_level));
685 tem->prev = momentary_stack;
686 tem->base = (char *) obstack_base (&momentary_obstack);
687 tem->obstack = expression_obstack;
688 momentary_stack = tem;
689 expression_obstack = &momentary_obstack;
692 /* Free all the storage in the current momentary-allocation level.
693 In C, this happens at the end of each statement. */
698 obstack_free (&momentary_obstack, momentary_stack->base);
701 /* Discard a level of momentary allocation.
702 In C, this happens at the end of each compound statement.
703 Restore the status of expression node allocation
704 that was in effect before this level was created. */
709 struct momentary_level *tem = momentary_stack;
710 momentary_stack = tem->prev;
711 expression_obstack = tem->obstack;
712 obstack_free (&momentary_obstack, tem);
715 /* Call when starting to parse a declaration:
716 make expressions in the declaration last the length of the function.
717 Returns an argument that should be passed to resume_momentary later. */
722 register int tem = expression_obstack == &momentary_obstack;
723 expression_obstack = saveable_obstack;
727 /* Call when finished parsing a declaration:
728 restore the treatment of node-allocation that was
729 in effect before the suspension.
730 YES should be the value previously returned by suspend_momentary. */
733 resume_momentary (yes)
737 expression_obstack = &momentary_obstack;
740 /* Init the tables indexed by tree code.
741 Note that languages can add to these tables to define their own codes. */
746 tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type));
747 tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length));
748 tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name));
749 bcopy (standard_tree_code_type, tree_code_type,
750 sizeof (standard_tree_code_type));
751 bcopy (standard_tree_code_length, tree_code_length,
752 sizeof (standard_tree_code_length));
753 bcopy (standard_tree_code_name, tree_code_name,
754 sizeof (standard_tree_code_name));
757 /* Return a newly allocated node of code CODE.
758 Initialize the node's unique id and its TREE_PERMANENT flag.
759 For decl and type nodes, some other fields are initialized.
760 The rest of the node is initialized to zero.
762 Achoo! I got a code in the node. */
769 register int type = TREE_CODE_CLASS (code);
771 register struct obstack *obstack = current_obstack;
773 register tree_node_kind kind;
777 case 'd': /* A decl node */
778 #ifdef GATHER_STATISTICS
781 length = sizeof (struct tree_decl);
782 /* All decls in an inline function need to be saved. */
783 if (obstack != &permanent_obstack)
784 obstack = saveable_obstack;
785 /* PARM_DECLs always go on saveable_obstack, not permanent,
786 even though we may make them before the function turns
787 on temporary allocation. */
788 else if (code == PARM_DECL)
789 obstack = function_maybepermanent_obstack;
792 case 't': /* a type node */
793 #ifdef GATHER_STATISTICS
796 length = sizeof (struct tree_type);
797 /* All data types are put where we can preserve them if nec. */
798 if (obstack != &permanent_obstack)
799 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
802 case 'b': /* a lexical block */
803 #ifdef GATHER_STATISTICS
806 length = sizeof (struct tree_block);
807 /* All BLOCK nodes are put where we can preserve them if nec. */
808 if (obstack != &permanent_obstack)
809 obstack = saveable_obstack;
812 case 's': /* an expression with side effects */
813 #ifdef GATHER_STATISTICS
817 case 'r': /* a reference */
818 #ifdef GATHER_STATISTICS
822 case 'e': /* an expression */
823 case '<': /* a comparison expression */
824 case '1': /* a unary arithmetic expression */
825 case '2': /* a binary arithmetic expression */
826 #ifdef GATHER_STATISTICS
830 obstack = expression_obstack;
831 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
832 if (code == BIND_EXPR && obstack != &permanent_obstack)
833 obstack = saveable_obstack;
834 length = sizeof (struct tree_exp)
835 + (tree_code_length[(int) code] - 1) * sizeof (char *);
838 case 'c': /* a constant */
839 #ifdef GATHER_STATISTICS
842 obstack = expression_obstack;
844 /* We can't use tree_code_length for INTEGER_CST, since the number of
845 words is machine-dependent due to varying length of HOST_WIDE_INT,
846 which might be wider than a pointer (e.g., long long). Similarly
847 for REAL_CST, since the number of words is machine-dependent due
848 to varying size and alignment of `double'. */
850 if (code == INTEGER_CST)
851 length = sizeof (struct tree_int_cst);
852 else if (code == REAL_CST)
853 length = sizeof (struct tree_real_cst);
855 length = sizeof (struct tree_common)
856 + tree_code_length[(int) code] * sizeof (char *);
859 case 'x': /* something random, like an identifier. */
860 #ifdef GATHER_STATISTICS
861 if (code == IDENTIFIER_NODE)
863 else if (code == OP_IDENTIFIER)
865 else if (code == TREE_VEC)
870 length = sizeof (struct tree_common)
871 + tree_code_length[(int) code] * sizeof (char *);
872 /* Identifier nodes are always permanent since they are
873 unique in a compiler run. */
874 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
877 t = (tree) obstack_alloc (obstack, length);
879 #ifdef GATHER_STATISTICS
880 tree_node_counts[(int)kind]++;
881 tree_node_sizes[(int)kind] += length;
884 /* Clear a word at a time. */
885 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
887 /* Clear any extra bytes. */
888 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
891 TREE_SET_CODE (t, code);
892 if (obstack == &permanent_obstack)
893 TREE_PERMANENT (t) = 1;
898 TREE_SIDE_EFFECTS (t) = 1;
899 TREE_TYPE (t) = void_type_node;
903 if (code != FUNCTION_DECL)
905 DECL_IN_SYSTEM_HEADER (t)
906 = in_system_header && (obstack == &permanent_obstack);
907 DECL_SOURCE_LINE (t) = lineno;
908 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
909 DECL_UID (t) = next_decl_uid++;
913 TYPE_UID (t) = next_type_uid++;
915 TYPE_MAIN_VARIANT (t) = t;
919 TREE_CONSTANT (t) = 1;
926 /* Return a new node with the same contents as NODE
927 except that its TREE_CHAIN is zero and it has a fresh uid. */
934 register enum tree_code code = TREE_CODE (node);
938 switch (TREE_CODE_CLASS (code))
940 case 'd': /* A decl node */
941 length = sizeof (struct tree_decl);
944 case 't': /* a type node */
945 length = sizeof (struct tree_type);
948 case 'b': /* a lexical block node */
949 length = sizeof (struct tree_block);
952 case 'r': /* a reference */
953 case 'e': /* an expression */
954 case 's': /* an expression with side effects */
955 case '<': /* a comparison expression */
956 case '1': /* a unary arithmetic expression */
957 case '2': /* a binary arithmetic expression */
958 length = sizeof (struct tree_exp)
959 + (tree_code_length[(int) code] - 1) * sizeof (char *);
962 case 'c': /* a constant */
963 /* We can't use tree_code_length for this, since the number of words
964 is machine-dependent due to varying alignment of `double'. */
965 if (code == REAL_CST)
967 length = sizeof (struct tree_real_cst);
971 case 'x': /* something random, like an identifier. */
972 length = sizeof (struct tree_common)
973 + tree_code_length[(int) code] * sizeof (char *);
974 if (code == TREE_VEC)
975 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
978 t = (tree) obstack_alloc (current_obstack, length);
980 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
981 ((int *) t)[i] = ((int *) node)[i];
982 /* Clear any extra bytes. */
983 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
984 ((char *) t)[i] = ((char *) node)[i];
988 if (TREE_CODE_CLASS (code) == 'd')
989 DECL_UID (t) = next_decl_uid++;
990 else if (TREE_CODE_CLASS (code) == 't')
991 TYPE_UID (t) = next_type_uid++;
993 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
998 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
999 For example, this can copy a list made of TREE_LIST nodes. */
1006 register tree prev, next;
1011 head = prev = copy_node (list);
1012 next = TREE_CHAIN (list);
1015 TREE_CHAIN (prev) = copy_node (next);
1016 prev = TREE_CHAIN (prev);
1017 next = TREE_CHAIN (next);
1024 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1025 If an identifier with that name has previously been referred to,
1026 the same node is returned this time. */
1029 get_identifier (text)
1030 register char *text;
1035 register int len, hash_len;
1037 /* Compute length of text in len. */
1038 for (len = 0; text[len]; len++);
1040 /* Decide how much of that length to hash on */
1042 if (warn_id_clash && len > id_clash_len)
1043 hash_len = id_clash_len;
1045 /* Compute hash code */
1046 hi = hash_len * 613 + (unsigned)text[0];
1047 for (i = 1; i < hash_len; i += 2)
1048 hi = ((hi * 613) + (unsigned)(text[i]));
1050 hi &= (1 << HASHBITS) - 1;
1051 hi %= MAX_HASH_TABLE;
1053 /* Search table for identifier */
1054 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1055 if (IDENTIFIER_LENGTH (idp) == len
1056 && IDENTIFIER_POINTER (idp)[0] == text[0]
1057 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1058 return idp; /* <-- return if found */
1060 /* Not found; optionally warn about a similar identifier */
1061 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1062 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1063 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1065 warning ("`%s' and `%s' identical in first %d characters",
1066 IDENTIFIER_POINTER (idp), text, id_clash_len);
1070 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1071 abort (); /* set_identifier_size hasn't been called. */
1073 /* Not found, create one, add to chain */
1074 idp = make_node (IDENTIFIER_NODE);
1075 IDENTIFIER_LENGTH (idp) = len;
1076 #ifdef GATHER_STATISTICS
1077 id_string_size += len;
1080 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1082 TREE_CHAIN (idp) = hash_table[hi];
1083 hash_table[hi] = idp;
1084 return idp; /* <-- return if created */
1087 /* Enable warnings on similar identifiers (if requested).
1088 Done after the built-in identifiers are created. */
1091 start_identifier_warnings ()
1093 do_identifier_warnings = 1;
1096 /* Record the size of an identifier node for the language in use.
1097 SIZE is the total size in bytes.
1098 This is called by the language-specific files. This must be
1099 called before allocating any identifiers. */
1102 set_identifier_size (size)
1105 tree_code_length[(int) IDENTIFIER_NODE]
1106 = (size - sizeof (struct tree_common)) / sizeof (tree);
1109 /* Return a newly constructed INTEGER_CST node whose constant value
1110 is specified by the two ints LOW and HI.
1111 The TREE_TYPE is set to `int'.
1113 This function should be used via the `build_int_2' macro. */
1116 build_int_2_wide (low, hi)
1117 HOST_WIDE_INT low, hi;
1119 register tree t = make_node (INTEGER_CST);
1120 TREE_INT_CST_LOW (t) = low;
1121 TREE_INT_CST_HIGH (t) = hi;
1122 TREE_TYPE (t) = integer_type_node;
1126 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1129 build_real (type, d)
1135 /* Check for valid float value for this type on this target machine;
1136 if not, can print error message and store a valid value in D. */
1137 #ifdef CHECK_FLOAT_VALUE
1138 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1141 v = make_node (REAL_CST);
1142 TREE_TYPE (v) = type;
1143 TREE_REAL_CST (v) = d;
1147 /* Return a new REAL_CST node whose type is TYPE
1148 and whose value is the integer value of the INTEGER_CST node I. */
1150 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1153 real_value_from_int_cst (i)
1158 /* Some 386 compilers mishandle unsigned int to float conversions,
1159 so introduce a temporary variable E to avoid those bugs. */
1161 #ifdef REAL_ARITHMETIC
1162 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1163 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1165 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1166 #else /* not REAL_ARITHMETIC */
1167 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1169 d = (double) (~ TREE_INT_CST_HIGH (i));
1170 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1171 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1173 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1179 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1180 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1181 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1183 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1186 #endif /* not REAL_ARITHMETIC */
1190 /* This function can't be implemented if we can't do arithmetic
1191 on the float representation. */
1194 build_real_from_int_cst (type, i)
1201 v = make_node (REAL_CST);
1202 TREE_TYPE (v) = type;
1204 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type), real_value_from_int_cst (i));
1205 /* Check for valid float value for this type on this target machine;
1206 if not, can print error message and store a valid value in D. */
1207 #ifdef CHECK_FLOAT_VALUE
1208 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1211 TREE_REAL_CST (v) = d;
1215 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1217 /* Return a newly constructed STRING_CST node whose value is
1218 the LEN characters at STR.
1219 The TREE_TYPE is not initialized. */
1222 build_string (len, str)
1226 register tree s = make_node (STRING_CST);
1227 TREE_STRING_LENGTH (s) = len;
1228 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1232 /* Return a newly constructed COMPLEX_CST node whose value is
1233 specified by the real and imaginary parts REAL and IMAG.
1234 Both REAL and IMAG should be constant nodes.
1235 The TREE_TYPE is not initialized. */
1238 build_complex (real, imag)
1241 register tree t = make_node (COMPLEX_CST);
1242 TREE_REALPART (t) = real;
1243 TREE_IMAGPART (t) = imag;
1244 TREE_TYPE (t) = build_complex_type (TREE_TYPE (real));
1248 /* Build a newly constructed TREE_VEC node of length LEN. */
1254 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1255 register struct obstack *obstack = current_obstack;
1258 #ifdef GATHER_STATISTICS
1259 tree_node_counts[(int)vec_kind]++;
1260 tree_node_sizes[(int)vec_kind] += length;
1263 t = (tree) obstack_alloc (obstack, length);
1265 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1268 TREE_SET_CODE (t, TREE_VEC);
1269 TREE_VEC_LENGTH (t) = len;
1270 if (obstack == &permanent_obstack)
1271 TREE_PERMANENT (t) = 1;
1276 /* Return 1 if EXPR is the integer constant zero. */
1279 integer_zerop (expr)
1284 return (TREE_CODE (expr) == INTEGER_CST
1285 && TREE_INT_CST_LOW (expr) == 0
1286 && TREE_INT_CST_HIGH (expr) == 0);
1289 /* Return 1 if EXPR is the integer constant one. */
1297 return (TREE_CODE (expr) == INTEGER_CST
1298 && TREE_INT_CST_LOW (expr) == 1
1299 && TREE_INT_CST_HIGH (expr) == 0);
1302 /* Return 1 if EXPR is an integer containing all 1's
1303 in as much precision as it contains. */
1306 integer_all_onesp (expr)
1314 if (TREE_CODE (expr) != INTEGER_CST)
1317 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1319 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1321 prec = TYPE_PRECISION (TREE_TYPE (expr));
1322 if (prec >= HOST_BITS_PER_WIDE_INT)
1324 int high_value, shift_amount;
1326 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1328 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1329 /* Can not handle precisions greater than twice the host int size. */
1331 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1332 /* Shifting by the host word size is undefined according to the ANSI
1333 standard, so we must handle this as a special case. */
1336 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1338 return TREE_INT_CST_LOW (expr) == -1
1339 && TREE_INT_CST_HIGH (expr) == high_value;
1342 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1345 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1349 integer_pow2p (expr)
1352 HOST_WIDE_INT high, low;
1356 if (TREE_CODE (expr) != INTEGER_CST)
1359 high = TREE_INT_CST_HIGH (expr);
1360 low = TREE_INT_CST_LOW (expr);
1362 if (high == 0 && low == 0)
1365 return ((high == 0 && (low & (low - 1)) == 0)
1366 || (low == 0 && (high & (high - 1)) == 0));
1369 /* Return 1 if EXPR is the real constant zero. */
1377 return (TREE_CODE (expr) == REAL_CST
1378 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0));
1381 /* Return 1 if EXPR is the real constant one. */
1389 return (TREE_CODE (expr) == REAL_CST
1390 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1));
1393 /* Return 1 if EXPR is the real constant two. */
1401 return (TREE_CODE (expr) == REAL_CST
1402 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2));
1405 /* Nonzero if EXP is a constant or a cast of a constant. */
1408 really_constant_p (exp)
1411 /* This is not quite the same as STRIP_NOPS. It does more. */
1412 while (TREE_CODE (exp) == NOP_EXPR
1413 || TREE_CODE (exp) == CONVERT_EXPR
1414 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1415 exp = TREE_OPERAND (exp, 0);
1416 return TREE_CONSTANT (exp);
1419 /* Return first list element whose TREE_VALUE is ELEM.
1420 Return 0 if ELEM is not it LIST. */
1423 value_member (elem, list)
1428 if (elem == TREE_VALUE (list))
1430 list = TREE_CHAIN (list);
1435 /* Return first list element whose TREE_PURPOSE is ELEM.
1436 Return 0 if ELEM is not it LIST. */
1439 purpose_member (elem, list)
1444 if (elem == TREE_PURPOSE (list))
1446 list = TREE_CHAIN (list);
1451 /* Return first list element whose BINFO_TYPE is ELEM.
1452 Return 0 if ELEM is not it LIST. */
1455 binfo_member (elem, list)
1460 if (elem == BINFO_TYPE (list))
1462 list = TREE_CHAIN (list);
1467 /* Return nonzero if ELEM is part of the chain CHAIN. */
1470 chain_member (elem, chain)
1477 chain = TREE_CHAIN (chain);
1483 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1484 We expect a null pointer to mark the end of the chain.
1485 This is the Lisp primitive `length'. */
1492 register int len = 0;
1494 for (tail = t; tail; tail = TREE_CHAIN (tail))
1500 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1501 by modifying the last node in chain 1 to point to chain 2.
1502 This is the Lisp primitive `nconc'. */
1512 for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t))
1513 if (t == op2) abort (); /* Circularity being created */
1514 if (t == op2) abort (); /* Circularity being created */
1515 TREE_CHAIN (t) = op2;
1521 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1525 register tree chain;
1529 while (next = TREE_CHAIN (chain))
1534 /* Reverse the order of elements in the chain T,
1535 and return the new head of the chain (old last element). */
1541 register tree prev = 0, decl, next;
1542 for (decl = t; decl; decl = next)
1544 next = TREE_CHAIN (decl);
1545 TREE_CHAIN (decl) = prev;
1551 /* Given a chain CHAIN of tree nodes,
1552 construct and return a list of those nodes. */
1558 tree result = NULL_TREE;
1559 tree in_tail = chain;
1560 tree out_tail = NULL_TREE;
1564 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1566 TREE_CHAIN (out_tail) = next;
1570 in_tail = TREE_CHAIN (in_tail);
1576 /* Return a newly created TREE_LIST node whose
1577 purpose and value fields are PARM and VALUE. */
1580 build_tree_list (parm, value)
1583 register tree t = make_node (TREE_LIST);
1584 TREE_PURPOSE (t) = parm;
1585 TREE_VALUE (t) = value;
1589 /* Similar, but build on the temp_decl_obstack. */
1592 build_decl_list (parm, value)
1596 register struct obstack *ambient_obstack = current_obstack;
1597 current_obstack = &temp_decl_obstack;
1598 node = build_tree_list (parm, value);
1599 current_obstack = ambient_obstack;
1603 /* Return a newly created TREE_LIST node whose
1604 purpose and value fields are PARM and VALUE
1605 and whose TREE_CHAIN is CHAIN. */
1608 tree_cons (purpose, value, chain)
1609 tree purpose, value, chain;
1612 register tree node = make_node (TREE_LIST);
1615 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
1616 #ifdef GATHER_STATISTICS
1617 tree_node_counts[(int)x_kind]++;
1618 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
1621 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
1622 ((int *) node)[i] = 0;
1624 TREE_SET_CODE (node, TREE_LIST);
1625 if (current_obstack == &permanent_obstack)
1626 TREE_PERMANENT (node) = 1;
1629 TREE_CHAIN (node) = chain;
1630 TREE_PURPOSE (node) = purpose;
1631 TREE_VALUE (node) = value;
1635 /* Similar, but build on the temp_decl_obstack. */
1638 decl_tree_cons (purpose, value, chain)
1639 tree purpose, value, chain;
1642 register struct obstack *ambient_obstack = current_obstack;
1643 current_obstack = &temp_decl_obstack;
1644 node = tree_cons (purpose, value, chain);
1645 current_obstack = ambient_obstack;
1649 /* Same as `tree_cons' but make a permanent object. */
1652 perm_tree_cons (purpose, value, chain)
1653 tree purpose, value, chain;
1656 register struct obstack *ambient_obstack = current_obstack;
1657 current_obstack = &permanent_obstack;
1659 node = tree_cons (purpose, value, chain);
1660 current_obstack = ambient_obstack;
1664 /* Same as `tree_cons', but make this node temporary, regardless. */
1667 temp_tree_cons (purpose, value, chain)
1668 tree purpose, value, chain;
1671 register struct obstack *ambient_obstack = current_obstack;
1672 current_obstack = &temporary_obstack;
1674 node = tree_cons (purpose, value, chain);
1675 current_obstack = ambient_obstack;
1679 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
1682 saveable_tree_cons (purpose, value, chain)
1683 tree purpose, value, chain;
1686 register struct obstack *ambient_obstack = current_obstack;
1687 current_obstack = saveable_obstack;
1689 node = tree_cons (purpose, value, chain);
1690 current_obstack = ambient_obstack;
1694 /* Return the size nominally occupied by an object of type TYPE
1695 when it resides in memory. The value is measured in units of bytes,
1696 and its data type is that normally used for type sizes
1697 (which is the first type created by make_signed_type or
1698 make_unsigned_type). */
1701 size_in_bytes (type)
1706 if (type == error_mark_node)
1707 return integer_zero_node;
1708 type = TYPE_MAIN_VARIANT (type);
1709 if (TYPE_SIZE (type) == 0)
1711 incomplete_type_error (NULL_TREE, type);
1712 return integer_zero_node;
1714 t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1715 size_int (BITS_PER_UNIT));
1716 if (TREE_CODE (t) == INTEGER_CST)
1717 force_fit_type (t, 0);
1721 /* Return the size of TYPE (in bytes) as an integer,
1722 or return -1 if the size can vary. */
1725 int_size_in_bytes (type)
1729 if (type == error_mark_node)
1731 type = TYPE_MAIN_VARIANT (type);
1732 if (TYPE_SIZE (type) == 0)
1734 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1736 if (TREE_INT_CST_HIGH (TYPE_SIZE (type)) != 0)
1738 tree t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1739 size_int (BITS_PER_UNIT));
1740 return TREE_INT_CST_LOW (t);
1742 size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1743 return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1746 /* Return, as a tree node, the number of elements for TYPE (which is an
1747 ARRAY_TYPE) minus one. This counts only elements of the top array. */
1750 array_type_nelts (type)
1753 tree index_type = TYPE_DOMAIN (type);
1755 return (integer_zerop (TYPE_MIN_VALUE (index_type))
1756 ? TYPE_MAX_VALUE (index_type)
1757 : fold (build (MINUS_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)),
1758 TYPE_MAX_VALUE (index_type),
1759 TYPE_MIN_VALUE (index_type))));
1762 /* Return nonzero if arg is static -- a reference to an object in
1763 static storage. This is not the same as the C meaning of `static'. */
1769 switch (TREE_CODE (arg))
1774 return TREE_STATIC (arg) || DECL_EXTERNAL (arg);
1781 return staticp (TREE_OPERAND (arg, 0));
1784 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
1787 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1788 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1789 return staticp (TREE_OPERAND (arg, 0));
1795 /* This should be applied to any node which may be used in more than one place,
1796 but must be evaluated only once. Normally, the code generator would
1797 reevaluate the node each time; this forces it to compute it once and save
1798 the result. This is done by encapsulating the node in a SAVE_EXPR. */
1804 register tree t = fold (expr);
1806 /* We don't care about whether this can be used as an lvalue in this
1808 while (TREE_CODE (t) == NON_LVALUE_EXPR)
1809 t = TREE_OPERAND (t, 0);
1811 /* If the tree evaluates to a constant, then we don't want to hide that
1812 fact (i.e. this allows further folding, and direct checks for constants).
1813 However, a read-only object that has side effects cannot be bypassed.
1814 Since it is no problem to reevaluate literals, we just return the
1817 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
1818 || TREE_CODE (t) == SAVE_EXPR)
1821 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
1823 /* This expression might be placed ahead of a jump to ensure that the
1824 value was computed on both sides of the jump. So make sure it isn't
1825 eliminated as dead. */
1826 TREE_SIDE_EFFECTS (t) = 1;
1830 /* Stabilize a reference so that we can use it any number of times
1831 without causing its operands to be evaluated more than once.
1832 Returns the stabilized reference.
1834 Also allows conversion expressions whose operands are references.
1835 Any other kind of expression is returned unchanged. */
1838 stabilize_reference (ref)
1841 register tree result;
1842 register enum tree_code code = TREE_CODE (ref);
1849 /* No action is needed in this case. */
1855 case FIX_TRUNC_EXPR:
1856 case FIX_FLOOR_EXPR:
1857 case FIX_ROUND_EXPR:
1859 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
1863 result = build_nt (INDIRECT_REF,
1864 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
1868 result = build_nt (COMPONENT_REF,
1869 stabilize_reference (TREE_OPERAND (ref, 0)),
1870 TREE_OPERAND (ref, 1));
1874 result = build_nt (BIT_FIELD_REF,
1875 stabilize_reference (TREE_OPERAND (ref, 0)),
1876 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
1877 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
1881 result = build_nt (ARRAY_REF,
1882 stabilize_reference (TREE_OPERAND (ref, 0)),
1883 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
1886 /* If arg isn't a kind of lvalue we recognize, make no change.
1887 Caller should recognize the error for an invalid lvalue. */
1892 return error_mark_node;
1895 TREE_TYPE (result) = TREE_TYPE (ref);
1896 TREE_READONLY (result) = TREE_READONLY (ref);
1897 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
1898 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
1899 TREE_RAISES (result) = TREE_RAISES (ref);
1904 /* Subroutine of stabilize_reference; this is called for subtrees of
1905 references. Any expression with side-effects must be put in a SAVE_EXPR
1906 to ensure that it is only evaluated once.
1908 We don't put SAVE_EXPR nodes around everything, because assigning very
1909 simple expressions to temporaries causes us to miss good opportunities
1910 for optimizations. Among other things, the opportunity to fold in the
1911 addition of a constant into an addressing mode often gets lost, e.g.
1912 "y[i+1] += x;". In general, we take the approach that we should not make
1913 an assignment unless we are forced into it - i.e., that any non-side effect
1914 operator should be allowed, and that cse should take care of coalescing
1915 multiple utterances of the same expression should that prove fruitful. */
1918 stabilize_reference_1 (e)
1921 register tree result;
1922 register int length;
1923 register enum tree_code code = TREE_CODE (e);
1925 /* We cannot ignore const expressions because it might be a reference
1926 to a const array but whose index contains side-effects. But we can
1927 ignore things that are actual constant or that already have been
1928 handled by this function. */
1930 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
1933 switch (TREE_CODE_CLASS (code))
1943 /* If the expression has side-effects, then encase it in a SAVE_EXPR
1944 so that it will only be evaluated once. */
1945 /* The reference (r) and comparison (<) classes could be handled as
1946 below, but it is generally faster to only evaluate them once. */
1947 if (TREE_SIDE_EFFECTS (e))
1948 return save_expr (e);
1952 /* Constants need no processing. In fact, we should never reach
1957 /* Division is slow and tends to be compiled with jumps,
1958 especially the division by powers of 2 that is often
1959 found inside of an array reference. So do it just once. */
1960 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
1961 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
1962 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
1963 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
1964 return save_expr (e);
1965 /* Recursively stabilize each operand. */
1966 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
1967 stabilize_reference_1 (TREE_OPERAND (e, 1)));
1971 /* Recursively stabilize each operand. */
1972 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
1976 TREE_TYPE (result) = TREE_TYPE (e);
1977 TREE_READONLY (result) = TREE_READONLY (e);
1978 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
1979 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
1980 TREE_RAISES (result) = TREE_RAISES (e);
1985 /* Low-level constructors for expressions. */
1987 /* Build an expression of code CODE, data type TYPE,
1988 and operands as specified by the arguments ARG1 and following arguments.
1989 Expressions and reference nodes can be created this way.
1990 Constants, decls, types and misc nodes cannot be. */
1997 enum tree_code code;
1999 register int length;
2004 code = va_arg (p, enum tree_code);
2005 t = make_node (code);
2006 length = tree_code_length[(int) code];
2007 TREE_TYPE (t) = va_arg (p, tree);
2011 /* This is equivalent to the loop below, but faster. */
2012 register tree arg0 = va_arg (p, tree);
2013 register tree arg1 = va_arg (p, tree);
2014 TREE_OPERAND (t, 0) = arg0;
2015 TREE_OPERAND (t, 1) = arg1;
2016 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
2017 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
2018 TREE_SIDE_EFFECTS (t) = 1;
2020 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
2022 else if (length == 1)
2024 register tree arg0 = va_arg (p, tree);
2026 /* Call build1 for this! */
2027 if (TREE_CODE_CLASS (code) != 's')
2029 TREE_OPERAND (t, 0) = arg0;
2030 if (arg0 && TREE_SIDE_EFFECTS (arg0))
2031 TREE_SIDE_EFFECTS (t) = 1;
2032 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
2036 for (i = 0; i < length; i++)
2038 register tree operand = va_arg (p, tree);
2039 TREE_OPERAND (t, i) = operand;
2042 if (TREE_SIDE_EFFECTS (operand))
2043 TREE_SIDE_EFFECTS (t) = 1;
2044 if (TREE_RAISES (operand))
2045 TREE_RAISES (t) = 1;
2053 /* Same as above, but only builds for unary operators.
2054 Saves lions share of calls to `build'; cuts down use
2055 of varargs, which is expensive for RISC machines. */
2057 build1 (code, type, node)
2058 enum tree_code code;
2062 register struct obstack *obstack = current_obstack;
2063 register int i, length;
2064 register tree_node_kind kind;
2067 #ifdef GATHER_STATISTICS
2068 if (TREE_CODE_CLASS (code) == 'r')
2074 obstack = expression_obstack;
2075 length = sizeof (struct tree_exp);
2077 t = (tree) obstack_alloc (obstack, length);
2079 #ifdef GATHER_STATISTICS
2080 tree_node_counts[(int)kind]++;
2081 tree_node_sizes[(int)kind] += length;
2084 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
2087 TREE_TYPE (t) = type;
2088 TREE_SET_CODE (t, code);
2090 if (obstack == &permanent_obstack)
2091 TREE_PERMANENT (t) = 1;
2093 TREE_OPERAND (t, 0) = node;
2096 if (TREE_SIDE_EFFECTS (node))
2097 TREE_SIDE_EFFECTS (t) = 1;
2098 if (TREE_RAISES (node))
2099 TREE_RAISES (t) = 1;
2105 /* Similar except don't specify the TREE_TYPE
2106 and leave the TREE_SIDE_EFFECTS as 0.
2107 It is permissible for arguments to be null,
2108 or even garbage if their values do not matter. */
2115 register enum tree_code code;
2117 register int length;
2122 code = va_arg (p, enum tree_code);
2123 t = make_node (code);
2124 length = tree_code_length[(int) code];
2126 for (i = 0; i < length; i++)
2127 TREE_OPERAND (t, i) = va_arg (p, tree);
2133 /* Similar to `build_nt', except we build
2134 on the temp_decl_obstack, regardless. */
2137 build_parse_node (va_alist)
2140 register struct obstack *ambient_obstack = expression_obstack;
2142 register enum tree_code code;
2144 register int length;
2147 expression_obstack = &temp_decl_obstack;
2151 code = va_arg (p, enum tree_code);
2152 t = make_node (code);
2153 length = tree_code_length[(int) code];
2155 for (i = 0; i < length; i++)
2156 TREE_OPERAND (t, i) = va_arg (p, tree);
2159 expression_obstack = ambient_obstack;
2164 /* Commented out because this wants to be done very
2165 differently. See cp-lex.c. */
2167 build_op_identifier (op1, op2)
2170 register tree t = make_node (OP_IDENTIFIER);
2171 TREE_PURPOSE (t) = op1;
2172 TREE_VALUE (t) = op2;
2177 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
2178 We do NOT enter this node in any sort of symbol table.
2180 layout_decl is used to set up the decl's storage layout.
2181 Other slots are initialized to 0 or null pointers. */
2184 build_decl (code, name, type)
2185 enum tree_code code;
2190 t = make_node (code);
2192 /* if (type == error_mark_node)
2193 type = integer_type_node; */
2194 /* That is not done, deliberately, so that having error_mark_node
2195 as the type can suppress useless errors in the use of this variable. */
2197 DECL_NAME (t) = name;
2198 DECL_ASSEMBLER_NAME (t) = name;
2199 TREE_TYPE (t) = type;
2201 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
2203 else if (code == FUNCTION_DECL)
2204 DECL_MODE (t) = FUNCTION_MODE;
2209 /* BLOCK nodes are used to represent the structure of binding contours
2210 and declarations, once those contours have been exited and their contents
2211 compiled. This information is used for outputting debugging info. */
2214 build_block (vars, tags, subblocks, supercontext, chain)
2215 tree vars, tags, subblocks, supercontext, chain;
2217 register tree block = make_node (BLOCK);
2218 BLOCK_VARS (block) = vars;
2219 BLOCK_TYPE_TAGS (block) = tags;
2220 BLOCK_SUBBLOCKS (block) = subblocks;
2221 BLOCK_SUPERCONTEXT (block) = supercontext;
2222 BLOCK_CHAIN (block) = chain;
2226 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
2227 and its TYPE_VOLATILE is VOLATILEP.
2229 Such variant types already made are recorded so that duplicates
2232 A variant types should never be used as the type of an expression.
2233 Always copy the variant information into the TREE_READONLY
2234 and TREE_THIS_VOLATILE of the expression, and then give the expression
2235 as its type the "main variant", the variant whose TYPE_READONLY
2236 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
2240 build_type_variant (type, constp, volatilep)
2242 int constp, volatilep;
2244 register tree t, m = TYPE_MAIN_VARIANT (type);
2245 register struct obstack *ambient_obstack = current_obstack;
2247 /* Treat any nonzero argument as 1. */
2249 volatilep = !!volatilep;
2251 /* If not generating auxiliary info, search the chain of variants to see
2252 if there is already one there just like the one we need to have. If so,
2253 use that existing one.
2255 We don't do this in the case where we are generating aux info because
2256 in that case we want each typedef names to get it's own distinct type
2257 node, even if the type of this new typedef is the same as some other
2260 if (!flag_gen_aux_info)
2261 for (t = m; t; t = TYPE_NEXT_VARIANT (t))
2262 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t))
2265 /* We need a new one. */
2267 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2269 t = copy_node (type);
2270 TYPE_READONLY (t) = constp;
2271 TYPE_VOLATILE (t) = volatilep;
2272 TYPE_POINTER_TO (t) = 0;
2273 TYPE_REFERENCE_TO (t) = 0;
2275 /* Add this type to the chain of variants of TYPE. */
2276 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2277 TYPE_NEXT_VARIANT (m) = t;
2279 current_obstack = ambient_obstack;
2283 /* Give TYPE a new main variant: NEW_MAIN.
2284 This is the right thing to do only when something else
2285 about TYPE is modified in place. */
2288 change_main_variant (type, new_main)
2289 tree type, new_main;
2292 tree omain = TYPE_MAIN_VARIANT (type);
2294 /* Remove TYPE from the TYPE_NEXT_VARIANT chain of its main variant. */
2295 if (TYPE_NEXT_VARIANT (omain) == type)
2296 TYPE_NEXT_VARIANT (omain) = TYPE_NEXT_VARIANT (type);
2298 for (t = TYPE_NEXT_VARIANT (omain); t && TYPE_NEXT_VARIANT (t);
2299 t = TYPE_NEXT_VARIANT (t))
2300 if (TYPE_NEXT_VARIANT (t) == type)
2302 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (type);
2306 TYPE_MAIN_VARIANT (type) = new_main;
2307 TYPE_NEXT_VARIANT (type) = TYPE_NEXT_VARIANT (new_main);
2308 TYPE_NEXT_VARIANT (new_main) = type;
2311 /* Create a new variant of TYPE, equivalent but distinct.
2312 This is so the caller can modify it. */
2315 build_type_copy (type)
2318 register tree t, m = TYPE_MAIN_VARIANT (type);
2319 register struct obstack *ambient_obstack = current_obstack;
2322 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2324 t = copy_node (type);
2325 TYPE_POINTER_TO (t) = 0;
2326 TYPE_REFERENCE_TO (t) = 0;
2328 /* Add this type to the chain of variants of TYPE. */
2329 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2330 TYPE_NEXT_VARIANT (m) = t;
2332 current_obstack = ambient_obstack;
2336 /* Hashing of types so that we don't make duplicates.
2337 The entry point is `type_hash_canon'. */
2339 /* Each hash table slot is a bucket containing a chain
2340 of these structures. */
2344 struct type_hash *next; /* Next structure in the bucket. */
2345 int hashcode; /* Hash code of this type. */
2346 tree type; /* The type recorded here. */
2349 /* Now here is the hash table. When recording a type, it is added
2350 to the slot whose index is the hash code mod the table size.
2351 Note that the hash table is used for several kinds of types
2352 (function types, array types and array index range types, for now).
2353 While all these live in the same table, they are completely independent,
2354 and the hash code is computed differently for each of these. */
2356 #define TYPE_HASH_SIZE 59
2357 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
2359 /* Here is how primitive or already-canonicalized types' hash
2361 #define TYPE_HASH(TYPE) ((HOST_WIDE_INT) (TYPE) & 0777777)
2363 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
2364 with types in the TREE_VALUE slots), by adding the hash codes
2365 of the individual types. */
2368 type_hash_list (list)
2371 register int hashcode;
2373 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
2374 hashcode += TYPE_HASH (TREE_VALUE (tail));
2378 /* Look in the type hash table for a type isomorphic to TYPE.
2379 If one is found, return it. Otherwise return 0. */
2382 type_hash_lookup (hashcode, type)
2386 register struct type_hash *h;
2387 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
2388 if (h->hashcode == hashcode
2389 && TREE_CODE (h->type) == TREE_CODE (type)
2390 && TREE_TYPE (h->type) == TREE_TYPE (type)
2391 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
2392 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
2393 TYPE_MAX_VALUE (type)))
2394 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
2395 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
2396 TYPE_MIN_VALUE (type)))
2397 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
2398 || (TYPE_DOMAIN (h->type)
2399 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
2400 && TYPE_DOMAIN (type)
2401 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
2402 && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
2407 /* Add an entry to the type-hash-table
2408 for a type TYPE whose hash code is HASHCODE. */
2411 type_hash_add (hashcode, type)
2415 register struct type_hash *h;
2417 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
2418 h->hashcode = hashcode;
2420 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
2421 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
2424 /* Given TYPE, and HASHCODE its hash code, return the canonical
2425 object for an identical type if one already exists.
2426 Otherwise, return TYPE, and record it as the canonical object
2427 if it is a permanent object.
2429 To use this function, first create a type of the sort you want.
2430 Then compute its hash code from the fields of the type that
2431 make it different from other similar types.
2432 Then call this function and use the value.
2433 This function frees the type you pass in if it is a duplicate. */
2435 /* Set to 1 to debug without canonicalization. Never set by program. */
2436 int debug_no_type_hash = 0;
2439 type_hash_canon (hashcode, type)
2445 if (debug_no_type_hash)
2448 t1 = type_hash_lookup (hashcode, type);
2452 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2453 obstack_free (o, type);
2454 #ifdef GATHER_STATISTICS
2455 tree_node_counts[(int)t_kind]--;
2456 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
2461 /* If this is a new type, record it for later reuse. */
2462 if (current_obstack == &permanent_obstack)
2463 type_hash_add (hashcode, type);
2468 /* Given two lists of types
2469 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
2470 return 1 if the lists contain the same types in the same order.
2471 Also, the TREE_PURPOSEs must match. */
2474 type_list_equal (l1, l2)
2477 register tree t1, t2;
2478 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
2480 if (TREE_VALUE (t1) != TREE_VALUE (t2))
2482 if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2))
2484 int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
2495 /* Nonzero if integer constants T1 and T2
2496 represent the same constant value. */
2499 tree_int_cst_equal (t1, t2)
2504 if (t1 == 0 || t2 == 0)
2506 if (TREE_CODE (t1) == INTEGER_CST
2507 && TREE_CODE (t2) == INTEGER_CST
2508 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2509 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
2514 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
2515 The precise way of comparison depends on their data type. */
2518 tree_int_cst_lt (t1, t2)
2524 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
2525 return INT_CST_LT (t1, t2);
2526 return INT_CST_LT_UNSIGNED (t1, t2);
2529 /* Compare two constructor-element-type constants. */
2531 simple_cst_list_equal (l1, l2)
2534 while (l1 != NULL_TREE && l2 != NULL_TREE)
2536 int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2));
2541 l1 = TREE_CHAIN (l1);
2542 l2 = TREE_CHAIN (l2);
2547 /* Return truthvalue of whether T1 is the same tree structure as T2.
2548 Return 1 if they are the same.
2549 Return 0 if they are understandably different.
2550 Return -1 if either contains tree structure not understood by
2554 simple_cst_equal (t1, t2)
2557 register enum tree_code code1, code2;
2562 if (t1 == 0 || t2 == 0)
2565 code1 = TREE_CODE (t1);
2566 code2 = TREE_CODE (t2);
2568 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
2569 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
2570 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2572 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
2573 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
2574 || code2 == NON_LVALUE_EXPR)
2575 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
2583 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2584 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
2587 return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2590 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2591 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2592 TREE_STRING_LENGTH (t1));
2598 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2601 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2604 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2607 /* Special case: if either target is an unallocated VAR_DECL,
2608 it means that it's going to be unified with whatever the
2609 TARGET_EXPR is really supposed to initialize, so treat it
2610 as being equivalent to anything. */
2611 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
2612 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
2613 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
2614 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
2615 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
2616 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
2619 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2622 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2624 case WITH_CLEANUP_EXPR:
2625 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2628 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
2631 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
2632 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2642 /* This general rule works for most tree codes.
2643 All exceptions should be handled above. */
2645 switch (TREE_CODE_CLASS (code1))
2655 for (i=0; i<tree_code_length[(int) code1]; ++i)
2657 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
2667 /* Constructors for pointer, array and function types.
2668 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
2669 constructed by language-dependent code, not here.) */
2671 /* Construct, lay out and return the type of pointers to TO_TYPE.
2672 If such a type has already been constructed, reuse it. */
2675 build_pointer_type (to_type)
2678 register tree t = TYPE_POINTER_TO (to_type);
2679 register struct obstack *ambient_obstack = current_obstack;
2680 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2682 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2687 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2688 if (TREE_PERMANENT (to_type))
2690 current_obstack = &permanent_obstack;
2691 saveable_obstack = &permanent_obstack;
2694 t = make_node (POINTER_TYPE);
2695 TREE_TYPE (t) = to_type;
2697 /* Record this type as the pointer to TO_TYPE. */
2698 TYPE_POINTER_TO (to_type) = t;
2700 /* Lay out the type. This function has many callers that are concerned
2701 with expression-construction, and this simplifies them all.
2702 Also, it guarantees the TYPE_SIZE is permanent if the type is. */
2705 current_obstack = ambient_obstack;
2706 saveable_obstack = ambient_saveable_obstack;
2710 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
2711 MAXVAL should be the maximum value in the domain
2712 (one less than the length of the array). */
2715 build_index_type (maxval)
2718 register tree itype = make_node (INTEGER_TYPE);
2719 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2720 TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
2721 TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
2722 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
2723 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2724 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2725 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2726 if (TREE_CODE (maxval) == INTEGER_CST)
2728 int maxint = (int) TREE_INT_CST_LOW (maxval);
2729 /* If the domain should be empty, make sure the maxval
2730 remains -1 and is not spoiled by truncation. */
2731 if (INT_CST_LT (maxval, integer_zero_node))
2733 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
2734 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
2736 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
2742 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
2743 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
2744 low bound LOWVAL and high bound HIGHVAL.
2745 if TYPE==NULL_TREE, sizetype is used. */
2748 build_range_type (type, lowval, highval)
2749 tree type, lowval, highval;
2751 register tree itype = make_node (INTEGER_TYPE);
2752 TREE_TYPE (itype) = type;
2753 if (type == NULL_TREE)
2755 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
2756 TYPE_MIN_VALUE (itype) = convert (type, lowval);
2757 TYPE_MAX_VALUE (itype) = convert (type, highval);
2758 TYPE_MODE (itype) = TYPE_MODE (type);
2759 TYPE_SIZE (itype) = TYPE_SIZE (type);
2760 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
2761 if ((TREE_CODE (lowval) == INTEGER_CST)
2762 && (TREE_CODE (highval) == INTEGER_CST))
2764 HOST_WIDE_INT highint = TREE_INT_CST_LOW (highval);
2765 HOST_WIDE_INT lowint = TREE_INT_CST_LOW (lowval);
2766 int maxint = (int) (highint - lowint);
2767 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
2773 /* Just like build_index_type, but takes lowval and highval instead
2774 of just highval (maxval). */
2777 build_index_2_type (lowval,highval)
2778 tree lowval, highval;
2780 return build_range_type (NULL_TREE, lowval, highval);
2783 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
2784 Needed because when index types are not hashed, equal index types
2785 built at different times appear distinct, even though structurally,
2789 index_type_equal (itype1, itype2)
2790 tree itype1, itype2;
2792 if (TREE_CODE (itype1) != TREE_CODE (itype2))
2794 if (TREE_CODE (itype1) == INTEGER_TYPE)
2796 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
2797 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
2798 || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2))
2799 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
2801 if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2))
2802 && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2)))
2808 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
2809 and number of elements specified by the range of values of INDEX_TYPE.
2810 If such a type has already been constructed, reuse it. */
2813 build_array_type (elt_type, index_type)
2814 tree elt_type, index_type;
2819 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
2821 error ("arrays of functions are not meaningful");
2822 elt_type = integer_type_node;
2825 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
2826 build_pointer_type (elt_type);
2828 /* Allocate the array after the pointer type,
2829 in case we free it in type_hash_canon. */
2830 t = make_node (ARRAY_TYPE);
2831 TREE_TYPE (t) = elt_type;
2832 TYPE_DOMAIN (t) = index_type;
2834 if (index_type == 0)
2839 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
2840 t = type_hash_canon (hashcode, t);
2842 #if 0 /* This led to crashes, because it could put a temporary node
2843 on the TYPE_NEXT_VARIANT chain of a permanent one. */
2844 /* The main variant of an array type should always
2845 be an array whose element type is the main variant. */
2846 if (elt_type != TYPE_MAIN_VARIANT (elt_type))
2847 change_main_variant (t, build_array_type (TYPE_MAIN_VARIANT (elt_type),
2851 if (TYPE_SIZE (t) == 0)
2856 /* Construct, lay out and return
2857 the type of functions returning type VALUE_TYPE
2858 given arguments of types ARG_TYPES.
2859 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
2860 are data type nodes for the arguments of the function.
2861 If such a type has already been constructed, reuse it. */
2864 build_function_type (value_type, arg_types)
2865 tree value_type, arg_types;
2870 if (TREE_CODE (value_type) == FUNCTION_TYPE)
2872 error ("function return type cannot be function");
2873 value_type = integer_type_node;
2876 /* Make a node of the sort we want. */
2877 t = make_node (FUNCTION_TYPE);
2878 TREE_TYPE (t) = value_type;
2879 TYPE_ARG_TYPES (t) = arg_types;
2881 /* If we already have such a type, use the old one and free this one. */
2882 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
2883 t = type_hash_canon (hashcode, t);
2885 if (TYPE_SIZE (t) == 0)
2890 /* Build the node for the type of references-to-TO_TYPE. */
2893 build_reference_type (to_type)
2896 register tree t = TYPE_REFERENCE_TO (to_type);
2897 register struct obstack *ambient_obstack = current_obstack;
2898 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2900 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2905 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2906 if (TREE_PERMANENT (to_type))
2908 current_obstack = &permanent_obstack;
2909 saveable_obstack = &permanent_obstack;
2912 t = make_node (REFERENCE_TYPE);
2913 TREE_TYPE (t) = to_type;
2915 /* Record this type as the pointer to TO_TYPE. */
2916 TYPE_REFERENCE_TO (to_type) = t;
2920 current_obstack = ambient_obstack;
2921 saveable_obstack = ambient_saveable_obstack;
2925 /* Construct, lay out and return the type of methods belonging to class
2926 BASETYPE and whose arguments and values are described by TYPE.
2927 If that type exists already, reuse it.
2928 TYPE must be a FUNCTION_TYPE node. */
2931 build_method_type (basetype, type)
2932 tree basetype, type;
2937 /* Make a node of the sort we want. */
2938 t = make_node (METHOD_TYPE);
2940 if (TREE_CODE (type) != FUNCTION_TYPE)
2943 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2944 TREE_TYPE (t) = TREE_TYPE (type);
2946 /* The actual arglist for this function includes a "hidden" argument
2947 which is "this". Put it into the list of argument types. */
2950 = tree_cons (NULL_TREE,
2951 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
2953 /* If we already have such a type, use the old one and free this one. */
2954 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2955 t = type_hash_canon (hashcode, t);
2957 if (TYPE_SIZE (t) == 0)
2963 /* Construct, lay out and return the type of offsets to a value
2964 of type TYPE, within an object of type BASETYPE.
2965 If a suitable offset type exists already, reuse it. */
2968 build_offset_type (basetype, type)
2969 tree basetype, type;
2974 /* Make a node of the sort we want. */
2975 t = make_node (OFFSET_TYPE);
2977 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2978 TREE_TYPE (t) = type;
2980 /* If we already have such a type, use the old one and free this one. */
2981 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2982 t = type_hash_canon (hashcode, t);
2984 if (TYPE_SIZE (t) == 0)
2990 /* Create a complex type whose components are COMPONENT_TYPE. */
2993 build_complex_type (component_type)
2994 tree component_type;
2999 /* Make a node of the sort we want. */
3000 t = make_node (COMPLEX_TYPE);
3002 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
3003 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
3004 TYPE_READONLY (t) = TYPE_READONLY (component_type);
3006 /* If we already have such a type, use the old one and free this one. */
3007 hashcode = TYPE_HASH (component_type);
3008 t = type_hash_canon (hashcode, t);
3010 if (TYPE_SIZE (t) == 0)
3016 /* Return OP, stripped of any conversions to wider types as much as is safe.
3017 Converting the value back to OP's type makes a value equivalent to OP.
3019 If FOR_TYPE is nonzero, we return a value which, if converted to
3020 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
3022 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
3023 narrowest type that can hold the value, even if they don't exactly fit.
3024 Otherwise, bit-field references are changed to a narrower type
3025 only if they can be fetched directly from memory in that type.
3027 OP must have integer, real or enumeral type. Pointers are not allowed!
3029 There are some cases where the obvious value we could return
3030 would regenerate to OP if converted to OP's type,
3031 but would not extend like OP to wider types.
3032 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
3033 For example, if OP is (unsigned short)(signed char)-1,
3034 we avoid returning (signed char)-1 if FOR_TYPE is int,
3035 even though extending that to an unsigned short would regenerate OP,
3036 since the result of extending (signed char)-1 to (int)
3037 is different from (int) OP. */
3040 get_unwidened (op, for_type)
3044 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
3045 /* TYPE_PRECISION is safe in place of type_precision since
3046 pointer types are not allowed. */
3047 register tree type = TREE_TYPE (op);
3048 register unsigned final_prec
3049 = TYPE_PRECISION (for_type != 0 ? for_type : type);
3051 = (for_type != 0 && for_type != type
3052 && final_prec > TYPE_PRECISION (type)
3053 && TREE_UNSIGNED (type));
3054 register tree win = op;
3056 while (TREE_CODE (op) == NOP_EXPR)
3058 register int bitschange
3059 = TYPE_PRECISION (TREE_TYPE (op))
3060 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3062 /* Truncations are many-one so cannot be removed.
3063 Unless we are later going to truncate down even farther. */
3065 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
3068 /* See what's inside this conversion. If we decide to strip it,
3070 op = TREE_OPERAND (op, 0);
3072 /* If we have not stripped any zero-extensions (uns is 0),
3073 we can strip any kind of extension.
3074 If we have previously stripped a zero-extension,
3075 only zero-extensions can safely be stripped.
3076 Any extension can be stripped if the bits it would produce
3077 are all going to be discarded later by truncating to FOR_TYPE. */
3081 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
3083 /* TREE_UNSIGNED says whether this is a zero-extension.
3084 Let's avoid computing it if it does not affect WIN
3085 and if UNS will not be needed again. */
3086 if ((uns || TREE_CODE (op) == NOP_EXPR)
3087 && TREE_UNSIGNED (TREE_TYPE (op)))
3095 if (TREE_CODE (op) == COMPONENT_REF
3096 /* Since type_for_size always gives an integer type. */
3097 && TREE_CODE (type) != REAL_TYPE)
3099 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3100 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
3102 /* We can get this structure field in the narrowest type it fits in.
3103 If FOR_TYPE is 0, do this only for a field that matches the
3104 narrower type exactly and is aligned for it
3105 The resulting extension to its nominal type (a fullword type)
3106 must fit the same conditions as for other extensions. */
3108 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3109 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
3110 && (! uns || final_prec <= innerprec
3111 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3114 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3115 TREE_OPERAND (op, 1));
3116 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3117 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3118 TREE_RAISES (win) = TREE_RAISES (op);
3124 /* Return OP or a simpler expression for a narrower value
3125 which can be sign-extended or zero-extended to give back OP.
3126 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
3127 or 0 if the value should be sign-extended. */
3130 get_narrower (op, unsignedp_ptr)
3134 register int uns = 0;
3136 register tree win = op;
3138 while (TREE_CODE (op) == NOP_EXPR)
3140 register int bitschange
3141 = TYPE_PRECISION (TREE_TYPE (op))
3142 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3144 /* Truncations are many-one so cannot be removed. */
3148 /* See what's inside this conversion. If we decide to strip it,
3150 op = TREE_OPERAND (op, 0);
3154 /* An extension: the outermost one can be stripped,
3155 but remember whether it is zero or sign extension. */
3157 uns = TREE_UNSIGNED (TREE_TYPE (op));
3158 /* Otherwise, if a sign extension has been stripped,
3159 only sign extensions can now be stripped;
3160 if a zero extension has been stripped, only zero-extensions. */
3161 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
3165 /* A change in nominal type can always be stripped. */
3170 if (TREE_CODE (op) == COMPONENT_REF
3171 /* Since type_for_size always gives an integer type. */
3172 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
3174 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3175 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
3177 /* We can get this structure field in a narrower type that fits it,
3178 but the resulting extension to its nominal type (a fullword type)
3179 must satisfy the same conditions as for other extensions.
3181 Do this only for fields that are aligned (not bit-fields),
3182 because when bit-field insns will be used there is no
3183 advantage in doing this. */
3185 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3186 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
3187 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3191 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
3192 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3193 TREE_OPERAND (op, 1));
3194 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3195 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3196 TREE_RAISES (win) = TREE_RAISES (op);
3199 *unsignedp_ptr = uns;
3203 /* Return the precision of a type, for arithmetic purposes.
3204 Supports all types on which arithmetic is possible
3205 (including pointer types).
3206 It's not clear yet what will be right for complex types. */
3209 type_precision (type)
3212 return ((TREE_CODE (type) == INTEGER_TYPE
3213 || TREE_CODE (type) == ENUMERAL_TYPE
3214 || TREE_CODE (type) == REAL_TYPE)
3215 ? TYPE_PRECISION (type) : POINTER_SIZE);
3218 /* Nonzero if integer constant C has a value that is permissible
3219 for type TYPE (an INTEGER_TYPE). */
3222 int_fits_type_p (c, type)
3225 if (TREE_UNSIGNED (type))
3226 return (!INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c)
3227 && !INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type))
3228 && (TREE_INT_CST_HIGH (c) >= 0 || TREE_UNSIGNED (TREE_TYPE (c))));
3230 return (!INT_CST_LT (TYPE_MAX_VALUE (type), c)
3231 && !INT_CST_LT (c, TYPE_MIN_VALUE (type))
3232 && (TREE_INT_CST_HIGH (c) >= 0 || !TREE_UNSIGNED (TREE_TYPE (c))));
3235 /* Return the innermost context enclosing DECL that is
3236 a FUNCTION_DECL, or zero if none. */
3239 decl_function_context (decl)
3244 if (TREE_CODE (decl) == ERROR_MARK)
3247 if (TREE_CODE (decl) == SAVE_EXPR)
3248 context = SAVE_EXPR_CONTEXT (decl);
3250 context = DECL_CONTEXT (decl);
3252 while (context && TREE_CODE (context) != FUNCTION_DECL)
3254 if (TREE_CODE (context) == RECORD_TYPE
3255 || TREE_CODE (context) == UNION_TYPE)
3256 context = TYPE_CONTEXT (context);
3257 else if (TREE_CODE (context) == TYPE_DECL)
3258 context = DECL_CONTEXT (context);
3259 else if (TREE_CODE (context) == BLOCK)
3260 context = BLOCK_SUPERCONTEXT (context);
3262 /* Unhandled CONTEXT !? */
3269 /* Return the innermost context enclosing DECL that is
3270 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
3271 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
3274 decl_type_context (decl)
3277 tree context = DECL_CONTEXT (decl);
3281 if (TREE_CODE (context) == RECORD_TYPE
3282 || TREE_CODE (context) == UNION_TYPE
3283 || TREE_CODE (context) == QUAL_UNION_TYPE)
3285 if (TREE_CODE (context) == TYPE_DECL
3286 || TREE_CODE (context) == FUNCTION_DECL)
3287 context = DECL_CONTEXT (context);
3288 else if (TREE_CODE (context) == BLOCK)
3289 context = BLOCK_SUPERCONTEXT (context);
3291 /* Unhandled CONTEXT!? */
3298 print_obstack_statistics (str, o)
3302 struct _obstack_chunk *chunk = o->chunk;
3309 n_alloc += chunk->limit - &chunk->contents[0];
3310 chunk = chunk->prev;
3312 fprintf (stderr, "obstack %s: %d bytes, %d chunks\n",
3313 str, n_alloc, n_chunks);
3316 dump_tree_statistics ()
3319 int total_nodes, total_bytes;
3321 fprintf (stderr, "\n??? tree nodes created\n\n");
3322 #ifdef GATHER_STATISTICS
3323 fprintf (stderr, "Kind Nodes Bytes\n");
3324 fprintf (stderr, "-------------------------------------\n");
3325 total_nodes = total_bytes = 0;
3326 for (i = 0; i < (int) all_kinds; i++)
3328 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
3329 tree_node_counts[i], tree_node_sizes[i]);
3330 total_nodes += tree_node_counts[i];
3331 total_bytes += tree_node_sizes[i];
3333 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
3334 fprintf (stderr, "-------------------------------------\n");
3335 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
3336 fprintf (stderr, "-------------------------------------\n");
3338 fprintf (stderr, "(No per-node statistics)\n");
3340 print_lang_statistics ();