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. */
198 d_kind, t_kind, s_kind, r_kind, e_kind, c_kind,
199 id_kind, op_id_kind, perm_list_kind, temp_list_kind,
200 vec_kind, x_kind, lang_decl, lang_type, all_kinds
202 int tree_node_counts[(int)all_kinds];
203 int tree_node_sizes[(int)all_kinds];
204 int id_string_size = 0;
205 char *tree_node_kind_names[] = { "decls", "types", "stmts", "refs", "exprs", "constants",
206 "identifiers", "op_identifiers", "perm_tree_lists", "temp_tree_lists",
207 "vecs", "random kinds", "lang_decl kinds", "lang_type kinds" };
209 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
211 #define MAX_HASH_TABLE 1009
212 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
214 /* 0 while creating built-in identifiers. */
215 static int do_identifier_warnings;
217 /* Unique id for next decl created. */
218 static int next_decl_uid;
220 extern char *mode_name[];
222 void gcc_obstack_init ();
223 static tree stabilize_reference_1 ();
225 /* Init the principal obstacks. */
230 gcc_obstack_init (&obstack_stack_obstack);
231 gcc_obstack_init (&permanent_obstack);
233 gcc_obstack_init (&temporary_obstack);
234 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
235 gcc_obstack_init (&momentary_obstack);
236 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
237 gcc_obstack_init (&maybepermanent_obstack);
238 maybepermanent_firstobj
239 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
240 gcc_obstack_init (&temp_decl_obstack);
241 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
243 function_obstack = &temporary_obstack;
244 function_maybepermanent_obstack = &maybepermanent_obstack;
245 current_obstack = &permanent_obstack;
246 expression_obstack = &permanent_obstack;
247 rtl_obstack = saveable_obstack = &permanent_obstack;
249 /* Init the hash table of identifiers. */
250 bzero (hash_table, sizeof hash_table);
254 gcc_obstack_init (obstack)
255 struct obstack *obstack;
257 /* Let particular systems override the size of a chunk. */
258 #ifndef OBSTACK_CHUNK_SIZE
259 #define OBSTACK_CHUNK_SIZE 0
261 /* Let them override the alloc and free routines too. */
262 #ifndef OBSTACK_CHUNK_ALLOC
263 #define OBSTACK_CHUNK_ALLOC xmalloc
265 #ifndef OBSTACK_CHUNK_FREE
266 #define OBSTACK_CHUNK_FREE free
268 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
269 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
270 (void (*) ()) OBSTACK_CHUNK_FREE);
273 /* Save all variables describing the current status into the structure *P.
274 This is used before starting a nested function. */
280 p->all_types_permanent = all_types_permanent;
281 p->momentary_stack = momentary_stack;
282 p->maybepermanent_firstobj = maybepermanent_firstobj;
283 p->momentary_firstobj = momentary_firstobj;
284 p->function_obstack = function_obstack;
285 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
286 p->current_obstack = current_obstack;
287 p->expression_obstack = expression_obstack;
288 p->saveable_obstack = saveable_obstack;
289 p->rtl_obstack = rtl_obstack;
291 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
292 gcc_obstack_init (function_obstack);
294 function_maybepermanent_obstack
295 = (struct obstack *) xmalloc (sizeof (struct obstack));
296 gcc_obstack_init (function_maybepermanent_obstack);
298 current_obstack = &permanent_obstack;
299 expression_obstack = &permanent_obstack;
300 rtl_obstack = saveable_obstack = &permanent_obstack;
302 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
303 maybepermanent_firstobj
304 = (char *) obstack_finish (function_maybepermanent_obstack);
307 /* Restore all variables describing the current status from the structure *P.
308 This is used after a nested function. */
311 restore_tree_status (p)
314 all_types_permanent = p->all_types_permanent;
315 momentary_stack = p->momentary_stack;
317 obstack_free (&momentary_obstack, momentary_firstobj);
318 obstack_free (function_obstack, 0);
319 obstack_free (function_maybepermanent_obstack, 0);
320 free (function_obstack);
322 momentary_firstobj = p->momentary_firstobj;
323 maybepermanent_firstobj = p->maybepermanent_firstobj;
324 function_obstack = p->function_obstack;
325 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
326 current_obstack = p->current_obstack;
327 expression_obstack = p->expression_obstack;
328 saveable_obstack = p->saveable_obstack;
329 rtl_obstack = p->rtl_obstack;
332 /* Start allocating on the temporary (per function) obstack.
333 This is done in start_function before parsing the function body,
334 and before each initialization at top level, and to go back
335 to temporary allocation after doing end_temporary_allocation. */
338 temporary_allocation ()
340 /* Note that function_obstack at top level points to temporary_obstack.
341 But within a nested function context, it is a separate obstack. */
342 current_obstack = function_obstack;
343 expression_obstack = function_obstack;
344 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
348 /* Start allocating on the permanent obstack but don't
349 free the temporary data. After calling this, call
350 `permanent_allocation' to fully resume permanent allocation status. */
353 end_temporary_allocation ()
355 current_obstack = &permanent_obstack;
356 expression_obstack = &permanent_obstack;
357 rtl_obstack = saveable_obstack = &permanent_obstack;
360 /* Resume allocating on the temporary obstack, undoing
361 effects of `end_temporary_allocation'. */
364 resume_temporary_allocation ()
366 current_obstack = function_obstack;
367 expression_obstack = function_obstack;
368 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
371 /* While doing temporary allocation, switch to allocating in such a
372 way as to save all nodes if the function is inlined. Call
373 resume_temporary_allocation to go back to ordinary temporary
377 saveable_allocation ()
379 /* Note that function_obstack at top level points to temporary_obstack.
380 But within a nested function context, it is a separate obstack. */
381 expression_obstack = current_obstack = saveable_obstack;
384 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
385 recording the previously current obstacks on a stack.
386 This does not free any storage in any obstack. */
389 push_obstacks (current, saveable)
390 struct obstack *current, *saveable;
392 struct obstack_stack *p
393 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
394 (sizeof (struct obstack_stack)));
396 p->current = current_obstack;
397 p->saveable = saveable_obstack;
398 p->expression = expression_obstack;
399 p->rtl = rtl_obstack;
400 p->next = obstack_stack;
403 current_obstack = current;
404 expression_obstack = current;
405 rtl_obstack = saveable_obstack = saveable;
408 /* Save the current set of obstacks, but don't change them. */
411 push_obstacks_nochange ()
413 struct obstack_stack *p
414 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
415 (sizeof (struct obstack_stack)));
417 p->current = current_obstack;
418 p->saveable = saveable_obstack;
419 p->expression = expression_obstack;
420 p->rtl = rtl_obstack;
421 p->next = obstack_stack;
425 /* Pop the obstack selection stack. */
430 struct obstack_stack *p = obstack_stack;
431 obstack_stack = p->next;
433 current_obstack = p->current;
434 saveable_obstack = p->saveable;
435 expression_obstack = p->expression;
436 rtl_obstack = p->rtl;
438 obstack_free (&obstack_stack_obstack, p);
441 /* Nonzero if temporary allocation is currently in effect.
442 Zero if currently doing permanent allocation. */
445 allocation_temporary_p ()
447 return current_obstack != &permanent_obstack;
450 /* Go back to allocating on the permanent obstack
451 and free everything in the temporary obstack.
452 This is done in finish_function after fully compiling a function. */
455 permanent_allocation ()
457 /* Free up previous temporary obstack data */
458 obstack_free (&temporary_obstack, temporary_firstobj);
459 obstack_free (&momentary_obstack, momentary_firstobj);
460 obstack_free (&maybepermanent_obstack, maybepermanent_firstobj);
461 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
463 current_obstack = &permanent_obstack;
464 expression_obstack = &permanent_obstack;
465 rtl_obstack = saveable_obstack = &permanent_obstack;
468 /* Save permanently everything on the maybepermanent_obstack. */
473 maybepermanent_firstobj
474 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
478 preserve_initializer ()
481 = (char *) obstack_alloc (&temporary_obstack, 0);
483 = (char *) obstack_alloc (&momentary_obstack, 0);
484 maybepermanent_firstobj
485 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
488 /* Start allocating new rtl in current_obstack.
489 Use resume_temporary_allocation
490 to go back to allocating rtl in saveable_obstack. */
493 rtl_in_current_obstack ()
495 rtl_obstack = current_obstack;
498 /* Temporarily allocate rtl from saveable_obstack. Return 1 if we were
499 previously allocating it from current_obstack. */
502 rtl_in_saveable_obstack ()
504 if (rtl_obstack == current_obstack)
506 rtl_obstack = saveable_obstack;
513 /* Allocate SIZE bytes in the current obstack
514 and return a pointer to them.
515 In practice the current obstack is always the temporary one. */
521 return (char *) obstack_alloc (current_obstack, size);
524 /* Free the object PTR in the current obstack
525 as well as everything allocated since PTR.
526 In practice the current obstack is always the temporary one. */
532 obstack_free (current_obstack, ptr);
535 /* Allocate SIZE bytes in the permanent obstack
536 and return a pointer to them. */
542 return (char *) obstack_alloc (&permanent_obstack, size);
545 /* Allocate NELEM items of SIZE bytes in the permanent obstack
546 and return a pointer to them. The storage is cleared before
547 returning the value. */
550 perm_calloc (nelem, size)
554 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
555 bzero (rval, nelem * size);
559 /* Allocate SIZE bytes in the saveable obstack
560 and return a pointer to them. */
566 return (char *) obstack_alloc (saveable_obstack, size);
569 /* Print out which obstack an object is in. */
572 debug_obstack (object)
575 struct obstack *obstack = NULL;
576 char *obstack_name = NULL;
579 for (p = outer_function_chain; p; p = p->next)
581 if (_obstack_allocated_p (p->function_obstack, object))
583 obstack = p->function_obstack;
584 obstack_name = "containing function obstack";
586 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
588 obstack = p->function_maybepermanent_obstack;
589 obstack_name = "containing function maybepermanent obstack";
593 if (_obstack_allocated_p (&obstack_stack_obstack, object))
595 obstack = &obstack_stack_obstack;
596 obstack_name = "obstack_stack_obstack";
598 else if (_obstack_allocated_p (function_obstack, object))
600 obstack = function_obstack;
601 obstack_name = "function obstack";
603 else if (_obstack_allocated_p (&permanent_obstack, object))
605 obstack = &permanent_obstack;
606 obstack_name = "permanent_obstack";
608 else if (_obstack_allocated_p (&momentary_obstack, object))
610 obstack = &momentary_obstack;
611 obstack_name = "momentary_obstack";
613 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
615 obstack = function_maybepermanent_obstack;
616 obstack_name = "function maybepermanent obstack";
618 else if (_obstack_allocated_p (&temp_decl_obstack, object))
620 obstack = &temp_decl_obstack;
621 obstack_name = "temp_decl_obstack";
624 /* Check to see if the object is in the free area of the obstack. */
627 if (object >= obstack->next_free
628 && object < obstack->chunk_limit)
629 fprintf (stderr, "object in free portion of obstack %s.\n",
632 fprintf (stderr, "object allocated from %s.\n", obstack_name);
635 fprintf (stderr, "object not allocated from any obstack.\n");
638 /* Return 1 if OBJ is in the permanent obstack.
639 This is slow, and should be used only for debugging.
640 Use TREE_PERMANENT for other purposes. */
643 object_permanent_p (obj)
646 return _obstack_allocated_p (&permanent_obstack, obj);
649 /* Start a level of momentary allocation.
650 In C, each compound statement has its own level
651 and that level is freed at the end of each statement.
652 All expression nodes are allocated in the momentary allocation level. */
657 struct momentary_level *tem
658 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
659 sizeof (struct momentary_level));
660 tem->prev = momentary_stack;
661 tem->base = (char *) obstack_base (&momentary_obstack);
662 tem->obstack = expression_obstack;
663 momentary_stack = tem;
664 expression_obstack = &momentary_obstack;
667 /* Free all the storage in the current momentary-allocation level.
668 In C, this happens at the end of each statement. */
673 obstack_free (&momentary_obstack, momentary_stack->base);
676 /* Discard a level of momentary allocation.
677 In C, this happens at the end of each compound statement.
678 Restore the status of expression node allocation
679 that was in effect before this level was created. */
684 struct momentary_level *tem = momentary_stack;
685 momentary_stack = tem->prev;
686 expression_obstack = tem->obstack;
687 obstack_free (&momentary_obstack, tem);
690 /* Call when starting to parse a declaration:
691 make expressions in the declaration last the length of the function.
692 Returns an argument that should be passed to resume_momentary later. */
697 register int tem = expression_obstack == &momentary_obstack;
698 expression_obstack = saveable_obstack;
702 /* Call when finished parsing a declaration:
703 restore the treatment of node-allocation that was
704 in effect before the suspension.
705 YES should be the value previously returned by suspend_momentary. */
708 resume_momentary (yes)
712 expression_obstack = &momentary_obstack;
715 /* Init the tables indexed by tree code.
716 Note that languages can add to these tables to define their own codes. */
721 tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type));
722 tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length));
723 tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name));
724 bcopy (standard_tree_code_type, tree_code_type,
725 sizeof (standard_tree_code_type));
726 bcopy (standard_tree_code_length, tree_code_length,
727 sizeof (standard_tree_code_length));
728 bcopy (standard_tree_code_name, tree_code_name,
729 sizeof (standard_tree_code_name));
732 /* Return a newly allocated node of code CODE.
733 Initialize the node's unique id and its TREE_PERMANENT flag.
734 For decl and type nodes, some other fields are initialized.
735 The rest of the node is initialized to zero.
737 Achoo! I got a code in the node. */
744 register int type = TREE_CODE_CLASS (code);
746 register struct obstack *obstack = current_obstack;
748 register tree_node_kind kind;
752 case 'd': /* A decl node */
753 #ifdef GATHER_STATISTICS
756 length = sizeof (struct tree_decl);
757 /* All decls in an inline function need to be saved. */
758 if (obstack != &permanent_obstack)
759 obstack = saveable_obstack;
760 /* PARM_DECLs always go on saveable_obstack, not permanent,
761 even though we may make them before the function turns
762 on temporary allocation. */
763 else if (code == PARM_DECL)
764 obstack = function_maybepermanent_obstack;
767 case 't': /* a type node */
768 #ifdef GATHER_STATISTICS
771 length = sizeof (struct tree_type);
772 /* All data types are put where we can preserve them if nec. */
773 if (obstack != &permanent_obstack)
774 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
777 case 's': /* an expression with side effects */
778 #ifdef GATHER_STATISTICS
782 case 'r': /* a reference */
783 #ifdef GATHER_STATISTICS
787 case 'e': /* an expression */
788 case '<': /* a comparison expression */
789 case '1': /* a unary arithmetic expression */
790 case '2': /* a binary arithmetic expression */
791 #ifdef GATHER_STATISTICS
795 obstack = expression_obstack;
796 /* All BLOCK nodes are put where we can preserve them if nec.
797 Also their potential controllers. */
798 if ((code == BLOCK || code == BIND_EXPR)
799 && obstack != &permanent_obstack)
800 obstack = saveable_obstack;
801 length = sizeof (struct tree_exp)
802 + (tree_code_length[(int) code] - 1) * sizeof (char *);
805 case 'c': /* a constant */
806 #ifdef GATHER_STATISTICS
809 obstack = expression_obstack;
810 /* We can't use tree_code_length for this, since the number of words
811 is machine-dependent due to varying alignment of `double'. */
812 if (code == REAL_CST)
814 length = sizeof (struct tree_real_cst);
818 case 'x': /* something random, like an identifier. */
819 #ifdef GATHER_STATISTICS
820 if (code == IDENTIFIER_NODE)
822 else if (code == OP_IDENTIFIER)
824 else if (code == TREE_VEC)
829 length = sizeof (struct tree_common)
830 + tree_code_length[(int) code] * sizeof (char *);
831 /* Identifier nodes are always permanent since they are
832 unique in a compiler run. */
833 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
836 t = (tree) obstack_alloc (obstack, length);
838 #ifdef GATHER_STATISTICS
839 tree_node_counts[(int)kind]++;
840 tree_node_sizes[(int)kind] += length;
843 /* We assume here that the length of a tree node is a multiple of the
844 size of an int. Rounding up won't work because it would clobber
846 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
849 TREE_SET_CODE (t, code);
850 if (obstack == &permanent_obstack)
851 TREE_PERMANENT (t) = 1;
856 TREE_SIDE_EFFECTS (t) = 1;
857 TREE_TYPE (t) = void_type_node;
861 if (code != FUNCTION_DECL)
862 DECL_IN_SYSTEM_HEADER (t) =
863 in_system_header && (obstack == &permanent_obstack);
865 DECL_SOURCE_LINE (t) = lineno;
866 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
867 DECL_UID (t) = next_decl_uid++;
872 static unsigned next_type_uid = 1;
874 TYPE_UID (t) = next_type_uid++;
877 TYPE_MAIN_VARIANT (t) = t;
881 TREE_CONSTANT (t) = 1;
888 /* Return a new node with the same contents as NODE
889 except that its TREE_CHAIN is zero and it has a fresh uid. */
896 register enum tree_code code = TREE_CODE (node);
900 switch (TREE_CODE_CLASS (code))
902 case 'd': /* A decl node */
903 length = sizeof (struct tree_decl);
906 case 't': /* a type node */
907 length = sizeof (struct tree_type);
910 case 'r': /* a reference */
911 case 'e': /* a expression */
912 case 's': /* an expression with side effects */
913 case '<': /* a comparison expression */
914 case '1': /* a unary arithmetic expression */
915 case '2': /* a binary arithmetic expression */
916 length = sizeof (struct tree_exp)
917 + (tree_code_length[(int) code] - 1) * sizeof (char *);
920 case 'c': /* a constant */
921 /* We can't use tree_code_length for this, since the number of words
922 is machine-dependent due to varying alignment of `double'. */
923 if (code == REAL_CST)
925 length = sizeof (struct tree_real_cst);
929 case 'x': /* something random, like an identifier. */
930 length = sizeof (struct tree_common)
931 + tree_code_length[(int) code] * sizeof (char *);
932 if (code == TREE_VEC)
933 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
936 t = (tree) obstack_alloc (current_obstack, length);
938 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
939 ((int *) t)[i] = ((int *) node)[i];
943 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
948 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
949 For example, this can copy a list made of TREE_LIST nodes. */
956 register tree prev, next;
961 head = prev = copy_node (list);
962 next = TREE_CHAIN (list);
965 TREE_CHAIN (prev) = copy_node (next);
966 prev = TREE_CHAIN (prev);
967 next = TREE_CHAIN (next);
974 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
975 If an identifier with that name has previously been referred to,
976 the same node is returned this time. */
979 get_identifier (text)
985 register int len, hash_len;
987 /* Compute length of text in len. */
988 for (len = 0; text[len]; len++);
990 /* Decide how much of that length to hash on */
992 if (warn_id_clash && len > id_clash_len)
993 hash_len = id_clash_len;
995 /* Compute hash code */
996 hi = hash_len * 613 + (unsigned)text[0];
997 for (i = 1; i < hash_len; i += 2)
998 hi = ((hi * 613) + (unsigned)(text[i]));
1000 hi &= (1 << HASHBITS) - 1;
1001 hi %= MAX_HASH_TABLE;
1003 /* Search table for identifier */
1004 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1005 if (IDENTIFIER_LENGTH (idp) == len
1006 && IDENTIFIER_POINTER (idp)[0] == text[0]
1007 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1008 return idp; /* <-- return if found */
1010 /* Not found; optionally warn about a similar identifier */
1011 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1012 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1013 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1015 warning ("`%s' and `%s' identical in first %d characters",
1016 IDENTIFIER_POINTER (idp), text, id_clash_len);
1020 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1021 abort (); /* set_identifier_size hasn't been called. */
1023 /* Not found, create one, add to chain */
1024 idp = make_node (IDENTIFIER_NODE);
1025 IDENTIFIER_LENGTH (idp) = len;
1026 #ifdef GATHER_STATISTICS
1027 id_string_size += len;
1030 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1032 TREE_CHAIN (idp) = hash_table[hi];
1033 hash_table[hi] = idp;
1034 return idp; /* <-- return if created */
1037 /* Enable warnings on similar identifiers (if requested).
1038 Done after the built-in identifiers are created. */
1041 start_identifier_warnings ()
1043 do_identifier_warnings = 1;
1046 /* Record the size of an identifier node for the language in use.
1047 SIZE is the total size in bytes.
1048 This is called by the language-specific files. This must be
1049 called before allocating any identifiers. */
1052 set_identifier_size (size)
1055 tree_code_length[(int) IDENTIFIER_NODE]
1056 = (size - sizeof (struct tree_common)) / sizeof (tree);
1059 /* Return a newly constructed INTEGER_CST node whose constant value
1060 is specified by the two ints LOW and HI.
1061 The TREE_TYPE is set to `int'.
1063 This function should be used via the `build_int_2' macro. */
1066 build_int_2_wide (low, hi)
1067 HOST_WIDE_INT low, hi;
1069 register tree t = make_node (INTEGER_CST);
1070 TREE_INT_CST_LOW (t) = low;
1071 TREE_INT_CST_HIGH (t) = hi;
1072 TREE_TYPE (t) = integer_type_node;
1076 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1079 build_real (type, d)
1085 /* Check for valid float value for this type on this target machine;
1086 if not, can print error message and store a valid value in D. */
1087 #ifdef CHECK_FLOAT_VALUE
1088 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1091 v = make_node (REAL_CST);
1092 TREE_TYPE (v) = type;
1093 TREE_REAL_CST (v) = d;
1097 /* Return a new REAL_CST node whose type is TYPE
1098 and whose value is the integer value of the INTEGER_CST node I. */
1100 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1103 real_value_from_int_cst (i)
1107 #ifdef REAL_ARITHMETIC
1108 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1109 #else /* not REAL_ARITHMETIC */
1110 if (TREE_INT_CST_HIGH (i) < 0)
1112 d = (double) (~ TREE_INT_CST_HIGH (i));
1113 d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1114 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1115 d += (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1120 d = (double) TREE_INT_CST_HIGH (i);
1121 d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1122 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1123 d += (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1125 #endif /* not REAL_ARITHMETIC */
1129 /* This function can't be implemented if we can't do arithmetic
1130 on the float representation. */
1133 build_real_from_int_cst (type, i)
1140 v = make_node (REAL_CST);
1141 TREE_TYPE (v) = type;
1143 d = real_value_from_int_cst (i);
1144 /* Check for valid float value for this type on this target machine;
1145 if not, can print error message and store a valid value in D. */
1146 #ifdef CHECK_FLOAT_VALUE
1147 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1150 TREE_REAL_CST (v) = d;
1154 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1156 /* Return a newly constructed STRING_CST node whose value is
1157 the LEN characters at STR.
1158 The TREE_TYPE is not initialized. */
1161 build_string (len, str)
1165 register tree s = make_node (STRING_CST);
1166 TREE_STRING_LENGTH (s) = len;
1167 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1171 /* Return a newly constructed COMPLEX_CST node whose value is
1172 specified by the real and imaginary parts REAL and IMAG.
1173 Both REAL and IMAG should be constant nodes.
1174 The TREE_TYPE is not initialized. */
1177 build_complex (real, imag)
1180 register tree t = make_node (COMPLEX_CST);
1181 TREE_REALPART (t) = real;
1182 TREE_IMAGPART (t) = imag;
1186 /* Build a newly constructed TREE_VEC node of length LEN. */
1192 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1193 register struct obstack *obstack = current_obstack;
1196 #ifdef GATHER_STATISTICS
1197 tree_node_counts[(int)vec_kind]++;
1198 tree_node_sizes[(int)vec_kind] += length;
1201 t = (tree) obstack_alloc (obstack, length);
1203 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1206 TREE_SET_CODE (t, TREE_VEC);
1207 TREE_VEC_LENGTH (t) = len;
1208 if (obstack == &permanent_obstack)
1209 TREE_PERMANENT (t) = 1;
1214 /* Return 1 if EXPR is the integer constant zero. */
1217 integer_zerop (expr)
1220 while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1221 expr = TREE_OPERAND (expr, 0);
1223 return (TREE_CODE (expr) == INTEGER_CST
1224 && TREE_INT_CST_LOW (expr) == 0
1225 && TREE_INT_CST_HIGH (expr) == 0);
1228 /* Return 1 if EXPR is the integer constant one. */
1234 while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1235 expr = TREE_OPERAND (expr, 0);
1237 return (TREE_CODE (expr) == INTEGER_CST
1238 && TREE_INT_CST_LOW (expr) == 1
1239 && TREE_INT_CST_HIGH (expr) == 0);
1242 /* Return 1 if EXPR is an integer containing all 1's
1243 in as much precision as it contains. */
1246 integer_all_onesp (expr)
1252 while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1253 expr = TREE_OPERAND (expr, 0);
1255 if (TREE_CODE (expr) != INTEGER_CST)
1258 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1260 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1262 prec = TYPE_PRECISION (TREE_TYPE (expr));
1263 if (prec >= HOST_BITS_PER_WIDE_INT)
1265 int high_value, shift_amount;
1267 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1269 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1270 /* Can not handle precisions greater than twice the host int size. */
1272 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1273 /* Shifting by the host word size is undefined according to the ANSI
1274 standard, so we must handle this as a special case. */
1277 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1279 return TREE_INT_CST_LOW (expr) == -1
1280 && TREE_INT_CST_HIGH (expr) == high_value;
1283 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1286 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1290 integer_pow2p (expr)
1293 HOST_WIDE_INT high, low;
1295 while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1296 expr = TREE_OPERAND (expr, 0);
1298 if (TREE_CODE (expr) != INTEGER_CST)
1301 high = TREE_INT_CST_HIGH (expr);
1302 low = TREE_INT_CST_LOW (expr);
1304 if (high == 0 && low == 0)
1307 return ((high == 0 && (low & (low - 1)) == 0)
1308 || (low == 0 && (high & (high - 1)) == 0));
1311 /* Return 1 if EXPR is the real constant zero. */
1317 while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1318 expr = TREE_OPERAND (expr, 0);
1320 return (TREE_CODE (expr) == REAL_CST
1321 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0));
1324 /* Return 1 if EXPR is the real constant one. */
1330 while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1331 expr = TREE_OPERAND (expr, 0);
1333 return (TREE_CODE (expr) == REAL_CST
1334 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1));
1337 /* Return 1 if EXPR is the real constant two. */
1343 while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1344 expr = TREE_OPERAND (expr, 0);
1346 return (TREE_CODE (expr) == REAL_CST
1347 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2));
1350 /* Nonzero if EXP is a constant or a cast of a constant. */
1353 really_constant_p (exp)
1356 while (TREE_CODE (exp) == NOP_EXPR
1357 || TREE_CODE (exp) == CONVERT_EXPR
1358 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1359 exp = TREE_OPERAND (exp, 0);
1360 return TREE_CONSTANT (exp);
1363 /* Return first list element whose TREE_VALUE is ELEM.
1364 Return 0 if ELEM is not it LIST. */
1367 value_member (elem, list)
1372 if (elem == TREE_VALUE (list))
1374 list = TREE_CHAIN (list);
1379 /* Return first list element whose TREE_PURPOSE is ELEM.
1380 Return 0 if ELEM is not it LIST. */
1383 purpose_member (elem, list)
1388 if (elem == TREE_PURPOSE (list))
1390 list = TREE_CHAIN (list);
1395 /* Return first list element whose BINFO_TYPE is ELEM.
1396 Return 0 if ELEM is not it LIST. */
1399 binfo_member (elem, list)
1404 if (elem == BINFO_TYPE (list))
1406 list = TREE_CHAIN (list);
1411 /* Return nonzero if ELEM is part of the chain CHAIN. */
1414 chain_member (elem, chain)
1421 chain = TREE_CHAIN (chain);
1427 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1428 We expect a null pointer to mark the end of the chain.
1429 This is the Lisp primitive `length'. */
1436 register int len = 0;
1438 for (tail = t; tail; tail = TREE_CHAIN (tail))
1444 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1445 by modifying the last node in chain 1 to point to chain 2.
1446 This is the Lisp primitive `nconc'. */
1456 for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t))
1457 if (t == op2) abort (); /* Circularity being created */
1458 TREE_CHAIN (t) = op2;
1464 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1468 register tree chain;
1472 while (next = TREE_CHAIN (chain))
1477 /* Reverse the order of elements in the chain T,
1478 and return the new head of the chain (old last element). */
1484 register tree prev = 0, decl, next;
1485 for (decl = t; decl; decl = next)
1487 next = TREE_CHAIN (decl);
1488 TREE_CHAIN (decl) = prev;
1494 /* Given a chain CHAIN of tree nodes,
1495 construct and return a list of those nodes. */
1501 tree result = NULL_TREE;
1502 tree in_tail = chain;
1503 tree out_tail = NULL_TREE;
1507 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1509 TREE_CHAIN (out_tail) = next;
1513 in_tail = TREE_CHAIN (in_tail);
1519 /* Return a newly created TREE_LIST node whose
1520 purpose and value fields are PARM and VALUE. */
1523 build_tree_list (parm, value)
1526 register tree t = make_node (TREE_LIST);
1527 TREE_PURPOSE (t) = parm;
1528 TREE_VALUE (t) = value;
1532 /* Similar, but build on the temp_decl_obstack. */
1535 build_decl_list (parm, value)
1539 register struct obstack *ambient_obstack = current_obstack;
1540 current_obstack = &temp_decl_obstack;
1541 node = build_tree_list (parm, value);
1542 current_obstack = ambient_obstack;
1546 /* Return a newly created TREE_LIST node whose
1547 purpose and value fields are PARM and VALUE
1548 and whose TREE_CHAIN is CHAIN. */
1551 tree_cons (purpose, value, chain)
1552 tree purpose, value, chain;
1555 register tree node = make_node (TREE_LIST);
1558 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
1559 #ifdef GATHER_STATISTICS
1560 tree_node_counts[(int)x_kind]++;
1561 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
1564 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
1567 TREE_SET_CODE (node, TREE_LIST);
1568 if (current_obstack == &permanent_obstack)
1569 TREE_PERMANENT (node) = 1;
1572 TREE_CHAIN (node) = chain;
1573 TREE_PURPOSE (node) = purpose;
1574 TREE_VALUE (node) = value;
1578 /* Similar, but build on the temp_decl_obstack. */
1581 decl_tree_cons (purpose, value, chain)
1582 tree purpose, value, chain;
1585 register struct obstack *ambient_obstack = current_obstack;
1586 current_obstack = &temp_decl_obstack;
1587 node = tree_cons (purpose, value, chain);
1588 current_obstack = ambient_obstack;
1592 /* Same as `tree_cons' but make a permanent object. */
1595 perm_tree_cons (purpose, value, chain)
1596 tree purpose, value, chain;
1599 register struct obstack *ambient_obstack = current_obstack;
1600 current_obstack = &permanent_obstack;
1602 node = tree_cons (purpose, value, chain);
1603 current_obstack = ambient_obstack;
1607 /* Same as `tree_cons', but make this node temporary, regardless. */
1610 temp_tree_cons (purpose, value, chain)
1611 tree purpose, value, chain;
1614 register struct obstack *ambient_obstack = current_obstack;
1615 current_obstack = &temporary_obstack;
1617 node = tree_cons (purpose, value, chain);
1618 current_obstack = ambient_obstack;
1622 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
1625 saveable_tree_cons (purpose, value, chain)
1626 tree purpose, value, chain;
1629 register struct obstack *ambient_obstack = current_obstack;
1630 current_obstack = saveable_obstack;
1632 node = tree_cons (purpose, value, chain);
1633 current_obstack = ambient_obstack;
1637 /* Return the size nominally occupied by an object of type TYPE
1638 when it resides in memory. The value is measured in units of bytes,
1639 and its data type is that normally used for type sizes
1640 (which is the first type created by make_signed_type or
1641 make_unsigned_type). */
1644 size_in_bytes (type)
1647 if (type == error_mark_node)
1648 return integer_zero_node;
1649 type = TYPE_MAIN_VARIANT (type);
1650 if (TYPE_SIZE (type) == 0)
1652 incomplete_type_error (NULL_TREE, type);
1653 return integer_zero_node;
1655 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1656 size_int (BITS_PER_UNIT));
1659 /* Return the size of TYPE (in bytes) as an integer,
1660 or return -1 if the size can vary. */
1663 int_size_in_bytes (type)
1667 if (type == error_mark_node)
1669 type = TYPE_MAIN_VARIANT (type);
1670 if (TYPE_SIZE (type) == 0)
1672 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1674 size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1675 return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1678 /* Return, as an INTEGER_CST node, the number of elements for
1679 TYPE (which is an ARRAY_TYPE) minus one.
1680 This counts only elements of the top array. */
1683 array_type_nelts (type)
1686 tree index_type = TYPE_DOMAIN (type);
1687 return (tree_int_cst_equal (TYPE_MIN_VALUE (index_type), integer_zero_node)
1688 ? TYPE_MAX_VALUE (index_type)
1689 : fold (build (MINUS_EXPR, integer_type_node,
1690 TYPE_MAX_VALUE (index_type),
1691 TYPE_MIN_VALUE (index_type))));
1694 /* Return nonzero if arg is static -- a reference to an object in
1695 static storage. This is not the same as the C meaning of `static'. */
1701 switch (TREE_CODE (arg))
1706 return TREE_STATIC (arg) || TREE_EXTERNAL (arg);
1713 return staticp (TREE_OPERAND (arg, 0));
1716 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
1719 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1720 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1721 return staticp (TREE_OPERAND (arg, 0));
1727 /* This should be applied to any node which may be used in more than one place,
1728 but must be evaluated only once. Normally, the code generator would
1729 reevaluate the node each time; this forces it to compute it once and save
1730 the result. This is done by encapsulating the node in a SAVE_EXPR. */
1736 register tree t = fold (expr);
1738 /* We don't care about whether this can be used as an lvalue in this
1740 while (TREE_CODE (t) == NON_LVALUE_EXPR)
1741 t = TREE_OPERAND (t, 0);
1743 /* If the tree evaluates to a constant, then we don't want to hide that
1744 fact (i.e. this allows further folding, and direct checks for constants).
1745 However, a read-only object that has side effects cannot be bypassed.
1746 Since it is no problem to reevaluate literals, we just return the
1749 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
1750 || TREE_CODE (t) == SAVE_EXPR)
1753 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
1755 /* This expression might be placed ahead of a jump to ensure that the
1756 value was computed on both sides of the jump. So make sure it isn't
1757 eliminated as dead. */
1758 TREE_SIDE_EFFECTS (t) = 1;
1762 /* Stabilize a reference so that we can use it any number of times
1763 without causing its operands to be evaluated more than once.
1764 Returns the stabilized reference.
1766 Also allows conversion expressions whose operands are references.
1767 Any other kind of expression is returned unchanged. */
1770 stabilize_reference (ref)
1773 register tree result;
1774 register enum tree_code code = TREE_CODE (ref);
1781 /* No action is needed in this case. */
1787 case FIX_TRUNC_EXPR:
1788 case FIX_FLOOR_EXPR:
1789 case FIX_ROUND_EXPR:
1791 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
1795 result = build_nt (INDIRECT_REF,
1796 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
1800 result = build_nt (COMPONENT_REF,
1801 stabilize_reference (TREE_OPERAND (ref, 0)),
1802 TREE_OPERAND (ref, 1));
1806 result = build_nt (BIT_FIELD_REF,
1807 stabilize_reference (TREE_OPERAND (ref, 0)),
1808 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
1809 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
1813 result = build_nt (ARRAY_REF,
1814 stabilize_reference (TREE_OPERAND (ref, 0)),
1815 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
1818 /* If arg isn't a kind of lvalue we recognize, make no change.
1819 Caller should recognize the error for an invalid lvalue. */
1824 return error_mark_node;
1827 TREE_TYPE (result) = TREE_TYPE (ref);
1828 TREE_READONLY (result) = TREE_READONLY (ref);
1829 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
1830 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
1831 TREE_RAISES (result) = TREE_RAISES (ref);
1836 /* Subroutine of stabilize_reference; this is called for subtrees of
1837 references. Any expression with side-effects must be put in a SAVE_EXPR
1838 to ensure that it is only evaluated once.
1840 We don't put SAVE_EXPR nodes around everything, because assigning very
1841 simple expressions to temporaries causes us to miss good opportunities
1842 for optimizations. Among other things, the opportunity to fold in the
1843 addition of a constant into an addressing mode often gets lost, e.g.
1844 "y[i+1] += x;". In general, we take the approach that we should not make
1845 an assignment unless we are forced into it - i.e., that any non-side effect
1846 operator should be allowed, and that cse should take care of coalescing
1847 multiple utterances of the same expression should that prove fruitful. */
1850 stabilize_reference_1 (e)
1853 register tree result;
1854 register int length;
1855 register enum tree_code code = TREE_CODE (e);
1857 /* We cannot ignore const expressions because it might be a reference
1858 to a const array but whose index contains side-effects. But we can
1859 ignore things that are actual constant or that already have been
1860 handled by this function. */
1862 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
1865 switch (TREE_CODE_CLASS (code))
1874 /* If the expression has side-effects, then encase it in a SAVE_EXPR
1875 so that it will only be evaluated once. */
1876 /* The reference (r) and comparison (<) classes could be handled as
1877 below, but it is generally faster to only evaluate them once. */
1878 if (TREE_SIDE_EFFECTS (e))
1879 return save_expr (e);
1883 /* Constants need no processing. In fact, we should never reach
1888 /* Recursively stabilize each operand. */
1889 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
1890 stabilize_reference_1 (TREE_OPERAND (e, 1)));
1894 /* Recursively stabilize each operand. */
1895 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
1899 TREE_TYPE (result) = TREE_TYPE (e);
1900 TREE_READONLY (result) = TREE_READONLY (e);
1901 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
1902 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
1903 TREE_RAISES (result) = TREE_RAISES (e);
1908 /* Low-level constructors for expressions. */
1910 /* Build an expression of code CODE, data type TYPE,
1911 and operands as specified by the arguments ARG1 and following arguments.
1912 Expressions and reference nodes can be created this way.
1913 Constants, decls, types and misc nodes cannot be. */
1920 enum tree_code code;
1922 register int length;
1927 code = va_arg (p, enum tree_code);
1928 t = make_node (code);
1929 length = tree_code_length[(int) code];
1930 TREE_TYPE (t) = va_arg (p, tree);
1934 /* This is equivalent to the loop below, but faster. */
1935 register tree arg0 = va_arg (p, tree);
1936 register tree arg1 = va_arg (p, tree);
1937 TREE_OPERAND (t, 0) = arg0;
1938 TREE_OPERAND (t, 1) = arg1;
1939 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
1940 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
1941 TREE_SIDE_EFFECTS (t) = 1;
1943 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
1945 else if (length == 1)
1947 register tree arg0 = va_arg (p, tree);
1949 /* Call build1 for this! */
1950 if (TREE_CODE_CLASS (code) != 's')
1952 TREE_OPERAND (t, 0) = arg0;
1953 if (arg0 && TREE_SIDE_EFFECTS (arg0))
1954 TREE_SIDE_EFFECTS (t) = 1;
1955 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
1959 for (i = 0; i < length; i++)
1961 register tree operand = va_arg (p, tree);
1962 TREE_OPERAND (t, i) = operand;
1965 if (TREE_SIDE_EFFECTS (operand))
1966 TREE_SIDE_EFFECTS (t) = 1;
1967 if (TREE_RAISES (operand))
1968 TREE_RAISES (t) = 1;
1976 /* Same as above, but only builds for unary operators.
1977 Saves lions share of calls to `build'; cuts down use
1978 of varargs, which is expensive for RISC machines. */
1980 build1 (code, type, node)
1981 enum tree_code code;
1985 register struct obstack *obstack = current_obstack;
1986 register int i, length;
1987 register tree_node_kind kind;
1990 #ifdef GATHER_STATISTICS
1991 if (TREE_CODE_CLASS (code) == 'r')
1997 obstack = expression_obstack;
1998 length = sizeof (struct tree_exp);
2000 t = (tree) obstack_alloc (obstack, length);
2002 #ifdef GATHER_STATISTICS
2003 tree_node_counts[(int)kind]++;
2004 tree_node_sizes[(int)kind] += length;
2007 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
2010 TREE_TYPE (t) = type;
2011 TREE_SET_CODE (t, code);
2013 if (obstack == &permanent_obstack)
2014 TREE_PERMANENT (t) = 1;
2016 TREE_OPERAND (t, 0) = node;
2019 if (TREE_SIDE_EFFECTS (node))
2020 TREE_SIDE_EFFECTS (t) = 1;
2021 if (TREE_RAISES (node))
2022 TREE_RAISES (t) = 1;
2028 /* Similar except don't specify the TREE_TYPE
2029 and leave the TREE_SIDE_EFFECTS as 0.
2030 It is permissible for arguments to be null,
2031 or even garbage if their values do not matter. */
2038 register enum tree_code code;
2040 register int length;
2045 code = va_arg (p, enum tree_code);
2046 t = make_node (code);
2047 length = tree_code_length[(int) code];
2049 for (i = 0; i < length; i++)
2050 TREE_OPERAND (t, i) = va_arg (p, tree);
2056 /* Similar to `build_nt', except we build
2057 on the temp_decl_obstack, regardless. */
2060 build_parse_node (va_alist)
2063 register struct obstack *ambient_obstack = expression_obstack;
2065 register enum tree_code code;
2067 register int length;
2070 expression_obstack = &temp_decl_obstack;
2074 code = va_arg (p, enum tree_code);
2075 t = make_node (code);
2076 length = tree_code_length[(int) code];
2078 for (i = 0; i < length; i++)
2079 TREE_OPERAND (t, i) = va_arg (p, tree);
2082 expression_obstack = ambient_obstack;
2087 /* Commented out because this wants to be done very
2088 differently. See cp-lex.c. */
2090 build_op_identifier (op1, op2)
2093 register tree t = make_node (OP_IDENTIFIER);
2094 TREE_PURPOSE (t) = op1;
2095 TREE_VALUE (t) = op2;
2100 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
2101 We do NOT enter this node in any sort of symbol table.
2103 layout_decl is used to set up the decl's storage layout.
2104 Other slots are initialized to 0 or null pointers. */
2107 build_decl (code, name, type)
2108 enum tree_code code;
2113 t = make_node (code);
2115 /* if (type == error_mark_node)
2116 type = integer_type_node; */
2117 /* That is not done, deliberately, so that having error_mark_node
2118 as the type can suppress useless errors in the use of this variable. */
2120 DECL_NAME (t) = name;
2121 DECL_ASSEMBLER_NAME (t) = name;
2122 TREE_TYPE (t) = type;
2124 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
2126 else if (code == FUNCTION_DECL)
2127 DECL_MODE (t) = FUNCTION_MODE;
2132 /* BLOCK nodes are used to represent the structure of binding contours
2133 and declarations, once those contours have been exited and their contents
2134 compiled. This information is used for outputting debugging info.
2135 A BLOCK may have a "controller" which is a BIND_EXPR node.
2136 Then the BLOCK is ignored unless the controller has the TREE_USED flag. */
2139 build_block (vars, tags, subblocks, supercontext, chain)
2140 tree vars, tags, subblocks, supercontext, chain;
2142 register tree block = make_node (BLOCK);
2143 BLOCK_VARS (block) = vars;
2144 BLOCK_TYPE_TAGS (block) = tags;
2145 BLOCK_SUBBLOCKS (block) = subblocks;
2146 BLOCK_SUPERCONTEXT (block) = supercontext;
2147 BLOCK_CHAIN (block) = chain;
2151 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
2152 and its TYPE_VOLATILE is VOLATILEP.
2154 Such variant types already made are recorded so that duplicates
2157 A variant types should never be used as the type of an expression.
2158 Always copy the variant information into the TREE_READONLY
2159 and TREE_THIS_VOLATILE of the expression, and then give the expression
2160 as its type the "main variant", the variant whose TYPE_READONLY
2161 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
2165 build_type_variant (type, constp, volatilep)
2167 int constp, volatilep;
2169 register tree t, m = TYPE_MAIN_VARIANT (type);
2170 register struct obstack *ambient_obstack = current_obstack;
2172 /* Treat any nonzero argument as 1. */
2174 volatilep = !!volatilep;
2176 /* If not generating auxiliary info, search the chain of variants to see
2177 if there is already one there just like the one we need to have. If so,
2178 use that existing one.
2180 We don't do this in the case where we are generating aux info because
2181 in that case we want each typedef names to get it's own distinct type
2182 node, even if the type of this new typedef is the same as some other
2185 if (!flag_gen_aux_info)
2186 for (t = m; t; t = TYPE_NEXT_VARIANT (t))
2187 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t))
2190 /* We need a new one. */
2192 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2194 t = copy_node (type);
2195 TYPE_READONLY (t) = constp;
2196 TYPE_VOLATILE (t) = volatilep;
2197 TYPE_POINTER_TO (t) = 0;
2198 TYPE_REFERENCE_TO (t) = 0;
2200 /* Add this type to the chain of variants of TYPE. */
2201 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2202 TYPE_NEXT_VARIANT (m) = t;
2204 current_obstack = ambient_obstack;
2208 /* Create a new variant of TYPE, equivalent but distinct.
2209 This is so the caller can modify it. */
2212 build_type_copy (type)
2215 register tree t, m = TYPE_MAIN_VARIANT (type);
2216 register struct obstack *ambient_obstack = current_obstack;
2219 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2221 t = copy_node (type);
2222 TYPE_POINTER_TO (t) = 0;
2223 TYPE_REFERENCE_TO (t) = 0;
2225 /* Add this type to the chain of variants of TYPE. */
2226 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2227 TYPE_NEXT_VARIANT (m) = t;
2229 current_obstack = ambient_obstack;
2233 /* Hashing of types so that we don't make duplicates.
2234 The entry point is `type_hash_canon'. */
2236 /* Each hash table slot is a bucket containing a chain
2237 of these structures. */
2241 struct type_hash *next; /* Next structure in the bucket. */
2242 int hashcode; /* Hash code of this type. */
2243 tree type; /* The type recorded here. */
2246 /* Now here is the hash table. When recording a type, it is added
2247 to the slot whose index is the hash code mod the table size.
2248 Note that the hash table is used for several kinds of types
2249 (function types, array types and array index range types, for now).
2250 While all these live in the same table, they are completely independent,
2251 and the hash code is computed differently for each of these. */
2253 #define TYPE_HASH_SIZE 59
2254 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
2256 /* Here is how primitive or already-canonicalized types' hash
2258 #define TYPE_HASH(TYPE) ((int) (TYPE) & 0777777)
2260 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
2261 with types in the TREE_VALUE slots), by adding the hash codes
2262 of the individual types. */
2265 type_hash_list (list)
2268 register int hashcode;
2270 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
2271 hashcode += TYPE_HASH (TREE_VALUE (tail));
2275 /* Look in the type hash table for a type isomorphic to TYPE.
2276 If one is found, return it. Otherwise return 0. */
2279 type_hash_lookup (hashcode, type)
2283 register struct type_hash *h;
2284 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
2285 if (h->hashcode == hashcode
2286 && TREE_CODE (h->type) == TREE_CODE (type)
2287 && TREE_TYPE (h->type) == TREE_TYPE (type)
2288 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
2289 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
2290 TYPE_MAX_VALUE (type)))
2291 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
2292 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
2293 TYPE_MIN_VALUE (type)))
2294 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
2295 || (TYPE_DOMAIN (h->type)
2296 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
2297 && TYPE_DOMAIN (type)
2298 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
2299 && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
2304 /* Add an entry to the type-hash-table
2305 for a type TYPE whose hash code is HASHCODE. */
2308 type_hash_add (hashcode, type)
2312 register struct type_hash *h;
2314 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
2315 h->hashcode = hashcode;
2317 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
2318 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
2321 /* Given TYPE, and HASHCODE its hash code, return the canonical
2322 object for an identical type if one already exists.
2323 Otherwise, return TYPE, and record it as the canonical object
2324 if it is a permanent object.
2326 To use this function, first create a type of the sort you want.
2327 Then compute its hash code from the fields of the type that
2328 make it different from other similar types.
2329 Then call this function and use the value.
2330 This function frees the type you pass in if it is a duplicate. */
2332 /* Set to 1 to debug without canonicalization. Never set by program. */
2333 int debug_no_type_hash = 0;
2336 type_hash_canon (hashcode, type)
2342 if (debug_no_type_hash)
2345 t1 = type_hash_lookup (hashcode, type);
2349 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2350 obstack_free (o, type);
2351 #ifdef GATHER_STATISTICS
2352 tree_node_counts[(int)t_kind]--;
2353 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
2358 /* If this is a new type, record it for later reuse. */
2359 if (current_obstack == &permanent_obstack)
2360 type_hash_add (hashcode, type);
2365 /* Given two lists of types
2366 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
2367 return 1 if the lists contain the same types in the same order.
2368 Also, the TREE_PURPOSEs must match. */
2371 type_list_equal (l1, l2)
2374 register tree t1, t2;
2375 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
2377 if (TREE_VALUE (t1) != TREE_VALUE (t2))
2379 if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2))
2381 int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
2392 /* Nonzero if integer constants T1 and T2
2393 represent the same constant value. */
2396 tree_int_cst_equal (t1, t2)
2401 if (t1 == 0 || t2 == 0)
2403 if (TREE_CODE (t1) == INTEGER_CST
2404 && TREE_CODE (t2) == INTEGER_CST
2405 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2406 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
2411 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
2412 The precise way of comparison depends on their data type. */
2415 tree_int_cst_lt (t1, t2)
2421 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
2422 return INT_CST_LT (t1, t2);
2423 return INT_CST_LT_UNSIGNED (t1, t2);
2426 /* Compare two constructor-element-type constants. */
2428 simple_cst_list_equal (l1, l2)
2431 while (l1 != NULL_TREE && l2 != NULL_TREE)
2433 int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2));
2438 l1 = TREE_CHAIN (l1);
2439 l2 = TREE_CHAIN (l2);
2444 /* Return truthvalue of whether T1 is the same tree structure as T2.
2445 Return 1 if they are the same.
2446 Return 0 if they are understandably different.
2447 Return -1 if either contains tree structure not understood by
2451 simple_cst_equal (t1, t2)
2454 register enum tree_code code1, code2;
2459 if (t1 == 0 || t2 == 0)
2462 code1 = TREE_CODE (t1);
2463 code2 = TREE_CODE (t2);
2465 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
2466 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
2467 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2469 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
2470 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
2471 || code2 == NON_LVALUE_EXPR)
2472 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
2480 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2481 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
2484 return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2487 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2488 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2489 TREE_STRING_LENGTH (t1));
2495 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2498 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2501 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2504 /* Special case: if either target is an unallocated VAR_DECL,
2505 it means that it's going to be unified with whatever the
2506 TARGET_EXPR is really supposed to initialize, so treat it
2507 as being equivalent to anything. */
2508 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
2509 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
2510 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
2511 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
2512 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
2513 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
2516 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2519 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2521 case WITH_CLEANUP_EXPR:
2522 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2525 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
2528 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
2529 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2533 return (simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2534 && simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1))
2535 && simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t2, 2)));
2546 case TRUNC_DIV_EXPR:
2547 case TRUNC_MOD_EXPR:
2550 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2553 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2557 case REFERENCE_EXPR:
2559 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2563 return lang_simple_cst_equal (t1, t2);
2570 /* Constructors for pointer, array and function types.
2571 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
2572 constructed by language-dependent code, not here.) */
2574 /* Construct, lay out and return the type of pointers to TO_TYPE.
2575 If such a type has already been constructed, reuse it. */
2578 build_pointer_type (to_type)
2581 register tree t = TYPE_POINTER_TO (to_type);
2582 register struct obstack *ambient_obstack = current_obstack;
2583 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2585 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2590 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2591 if (TREE_PERMANENT (to_type))
2593 current_obstack = &permanent_obstack;
2594 saveable_obstack = &permanent_obstack;
2597 t = make_node (POINTER_TYPE);
2598 TREE_TYPE (t) = to_type;
2600 /* Record this type as the pointer to TO_TYPE. */
2601 TYPE_POINTER_TO (to_type) = t;
2603 /* Lay out the type. This function has many callers that are concerned
2604 with expression-construction, and this simplifies them all.
2605 Also, it guarantees the TYPE_SIZE is permanent if the type is. */
2608 current_obstack = ambient_obstack;
2609 saveable_obstack = ambient_saveable_obstack;
2613 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
2614 MAXVAL should be the maximum value in the domain
2615 (one less than the length of the array). */
2618 build_index_type (maxval)
2621 register tree itype = make_node (INTEGER_TYPE);
2622 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2623 TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
2624 TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
2625 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
2626 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2627 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2628 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2629 if (TREE_CODE (maxval) == INTEGER_CST)
2631 HOST_WIDE_INT maxint = TREE_INT_CST_LOW (maxval);
2632 return type_hash_canon (maxint > 0 ? maxint : - maxint, itype);
2638 /* Just like build_index_type, but takes lowval and highval instead
2639 of just highval (maxval). */
2642 build_index_2_type (lowval,highval)
2643 tree lowval, highval;
2645 register tree itype = make_node (INTEGER_TYPE);
2646 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2647 TYPE_MIN_VALUE (itype) = convert (sizetype, lowval);
2648 TYPE_MAX_VALUE (itype) = convert (sizetype, highval);
2649 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2650 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2651 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2652 if ((TREE_CODE (lowval) == INTEGER_CST)
2653 && (TREE_CODE (highval) == INTEGER_CST))
2655 HOST_WIDE_INT highint = TREE_INT_CST_LOW (highval);
2656 HOST_WIDE_INT lowint = TREE_INT_CST_LOW (lowval);
2657 HOST_WIDE_INT maxint = highint - lowint;
2658 return type_hash_canon (maxint > 0 ? maxint : - maxint, itype);
2664 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
2665 Needed because when index types are not hashed, equal index types
2666 built at different times appear distinct, even though structurally,
2670 index_type_equal (itype1, itype2)
2671 tree itype1, itype2;
2673 if (TREE_CODE (itype1) != TREE_CODE (itype2))
2675 if (TREE_CODE (itype1) == INTEGER_TYPE)
2677 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
2678 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
2679 || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2))
2680 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
2682 if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2))
2683 && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2)))
2689 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
2690 and number of elements specified by the range of values of INDEX_TYPE.
2691 If such a type has already been constructed, reuse it. */
2694 build_array_type (elt_type, index_type)
2695 tree elt_type, index_type;
2700 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
2702 error ("arrays of functions are not meaningful");
2703 elt_type = integer_type_node;
2706 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
2707 build_pointer_type (elt_type);
2709 /* Allocate the array after the pointer type,
2710 in case we free it in type_hash_canon. */
2711 t = make_node (ARRAY_TYPE);
2712 TREE_TYPE (t) = elt_type;
2713 TYPE_DOMAIN (t) = index_type;
2715 if (index_type == 0)
2718 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
2719 t = type_hash_canon (hashcode, t);
2721 if (TYPE_SIZE (t) == 0)
2726 /* Construct, lay out and return
2727 the type of functions returning type VALUE_TYPE
2728 given arguments of types ARG_TYPES.
2729 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
2730 are data type nodes for the arguments of the function.
2731 If such a type has already been constructed, reuse it. */
2734 build_function_type (value_type, arg_types)
2735 tree value_type, arg_types;
2740 if (TREE_CODE (value_type) == FUNCTION_TYPE
2741 || TREE_CODE (value_type) == ARRAY_TYPE)
2743 error ("function return type cannot be function or array");
2744 value_type = integer_type_node;
2747 /* Make a node of the sort we want. */
2748 t = make_node (FUNCTION_TYPE);
2749 TREE_TYPE (t) = value_type;
2750 TYPE_ARG_TYPES (t) = arg_types;
2752 /* If we already have such a type, use the old one and free this one. */
2753 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
2754 t = type_hash_canon (hashcode, t);
2756 if (TYPE_SIZE (t) == 0)
2761 /* Build the node for the type of references-to-TO_TYPE. */
2764 build_reference_type (to_type)
2767 register tree t = TYPE_REFERENCE_TO (to_type);
2768 register struct obstack *ambient_obstack = current_obstack;
2769 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2771 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2776 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2777 if (TREE_PERMANENT (to_type))
2779 current_obstack = &permanent_obstack;
2780 saveable_obstack = &permanent_obstack;
2783 t = make_node (REFERENCE_TYPE);
2784 TREE_TYPE (t) = to_type;
2786 /* Record this type as the pointer to TO_TYPE. */
2787 TYPE_REFERENCE_TO (to_type) = t;
2791 current_obstack = ambient_obstack;
2792 saveable_obstack = ambient_saveable_obstack;
2796 /* Construct, lay out and return the type of methods belonging to class
2797 BASETYPE and whose arguments and values are described by TYPE.
2798 If that type exists already, reuse it.
2799 TYPE must be a FUNCTION_TYPE node. */
2802 build_method_type (basetype, type)
2803 tree basetype, type;
2808 /* Make a node of the sort we want. */
2809 t = make_node (METHOD_TYPE);
2811 if (TREE_CODE (type) != FUNCTION_TYPE)
2814 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2815 TREE_TYPE (t) = TREE_TYPE (type);
2817 /* The actual arglist for this function includes a "hidden" argument
2818 which is "this". Put it into the list of argument types. */
2821 = tree_cons (NULL_TREE,
2822 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
2824 /* If we already have such a type, use the old one and free this one. */
2825 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2826 t = type_hash_canon (hashcode, t);
2828 if (TYPE_SIZE (t) == 0)
2834 /* Construct, lay out and return the type of methods belonging to class
2835 BASETYPE and whose arguments and values are described by TYPE.
2836 If that type exists already, reuse it.
2837 TYPE must be a FUNCTION_TYPE node. */
2840 build_offset_type (basetype, type)
2841 tree basetype, type;
2846 /* Make a node of the sort we want. */
2847 t = make_node (OFFSET_TYPE);
2849 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2850 TREE_TYPE (t) = type;
2852 /* If we already have such a type, use the old one and free this one. */
2853 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2854 t = type_hash_canon (hashcode, t);
2856 if (TYPE_SIZE (t) == 0)
2862 /* Create a complex type whose components are COMPONENT_TYPE. */
2865 build_complex_type (component_type)
2866 tree component_type;
2871 /* Make a node of the sort we want. */
2872 t = make_node (COMPLEX_TYPE);
2874 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
2875 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
2876 TYPE_READONLY (t) = TYPE_READONLY (component_type);
2878 /* If we already have such a type, use the old one and free this one. */
2879 hashcode = TYPE_HASH (component_type);
2880 t = type_hash_canon (hashcode, t);
2882 if (TYPE_SIZE (t) == 0)
2888 /* Return OP, stripped of any conversions to wider types as much as is safe.
2889 Converting the value back to OP's type makes a value equivalent to OP.
2891 If FOR_TYPE is nonzero, we return a value which, if converted to
2892 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
2894 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
2895 narrowest type that can hold the value, even if they don't exactly fit.
2896 Otherwise, bit-field references are changed to a narrower type
2897 only if they can be fetched directly from memory in that type.
2899 OP must have integer, real or enumeral type. Pointers are not allowed!
2901 There are some cases where the obvious value we could return
2902 would regenerate to OP if converted to OP's type,
2903 but would not extend like OP to wider types.
2904 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
2905 For example, if OP is (unsigned short)(signed char)-1,
2906 we avoid returning (signed char)-1 if FOR_TYPE is int,
2907 even though extending that to an unsigned short would regenerate OP,
2908 since the result of extending (signed char)-1 to (int)
2909 is different from (int) OP. */
2912 get_unwidened (op, for_type)
2916 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
2917 /* TYPE_PRECISION is safe in place of type_precision since
2918 pointer types are not allowed. */
2919 register tree type = TREE_TYPE (op);
2920 register unsigned final_prec
2921 = TYPE_PRECISION (for_type != 0 ? for_type : type);
2923 = (for_type != 0 && for_type != type
2924 && final_prec > TYPE_PRECISION (type)
2925 && TREE_UNSIGNED (type));
2926 register tree win = op;
2928 while (TREE_CODE (op) == NOP_EXPR)
2930 register int bitschange
2931 = TYPE_PRECISION (TREE_TYPE (op))
2932 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
2934 /* Truncations are many-one so cannot be removed.
2935 Unless we are later going to truncate down even farther. */
2937 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
2940 /* See what's inside this conversion. If we decide to strip it,
2942 op = TREE_OPERAND (op, 0);
2944 /* If we have not stripped any zero-extensions (uns is 0),
2945 we can strip any kind of extension.
2946 If we have previously stripped a zero-extension,
2947 only zero-extensions can safely be stripped.
2948 Any extension can be stripped if the bits it would produce
2949 are all going to be discarded later by truncating to FOR_TYPE. */
2953 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
2955 /* TREE_UNSIGNED says whether this is a zero-extension.
2956 Let's avoid computing it if it does not affect WIN
2957 and if UNS will not be needed again. */
2958 if ((uns || TREE_CODE (op) == NOP_EXPR)
2959 && TREE_UNSIGNED (TREE_TYPE (op)))
2967 if (TREE_CODE (op) == COMPONENT_REF
2968 /* Since type_for_size always gives an integer type. */
2969 && TREE_CODE (type) != REAL_TYPE)
2971 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
2972 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
2974 /* We can get this structure field in the narrowest type it fits in.
2975 If FOR_TYPE is 0, do this only for a field that matches the
2976 narrower type exactly and is aligned for it
2977 The resulting extension to its nominal type (a fullword type)
2978 must fit the same conditions as for other extensions. */
2980 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
2981 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
2982 && (! uns || final_prec <= innerprec
2983 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
2986 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
2987 TREE_OPERAND (op, 1));
2988 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
2989 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
2990 TREE_RAISES (win) = TREE_RAISES (op);
2996 /* Return OP or a simpler expression for a narrower value
2997 which can be sign-extended or zero-extended to give back OP.
2998 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
2999 or 0 if the value should be sign-extended. */
3002 get_narrower (op, unsignedp_ptr)
3006 register int uns = 0;
3008 register tree win = op;
3010 while (TREE_CODE (op) == NOP_EXPR)
3012 register int bitschange
3013 = TYPE_PRECISION (TREE_TYPE (op))
3014 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3016 /* Truncations are many-one so cannot be removed. */
3020 /* See what's inside this conversion. If we decide to strip it,
3022 op = TREE_OPERAND (op, 0);
3026 /* An extension: the outermost one can be stripped,
3027 but remember whether it is zero or sign extension. */
3029 uns = TREE_UNSIGNED (TREE_TYPE (op));
3030 /* Otherwise, if a sign extension has been stripped,
3031 only sign extensions can now be stripped;
3032 if a zero extension has been stripped, only zero-extensions. */
3033 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
3037 /* A change in nominal type can always be stripped. */
3042 if (TREE_CODE (op) == COMPONENT_REF
3043 /* Since type_for_size always gives an integer type. */
3044 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
3046 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3047 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
3049 /* We can get this structure field in a narrower type that fits it,
3050 but the resulting extension to its nominal type (a fullword type)
3051 must satisfy the same conditions as for other extensions.
3053 Do this only for fields that are aligned (not bit-fields),
3054 because when bit-field insns will be used there is no
3055 advantage in doing this. */
3057 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3058 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
3059 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3063 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
3064 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3065 TREE_OPERAND (op, 1));
3066 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3067 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3068 TREE_RAISES (win) = TREE_RAISES (op);
3071 *unsignedp_ptr = uns;
3075 /* Return the precision of a type, for arithmetic purposes.
3076 Supports all types on which arithmetic is possible
3077 (including pointer types).
3078 It's not clear yet what will be right for complex types. */
3081 type_precision (type)
3084 return ((TREE_CODE (type) == INTEGER_TYPE
3085 || TREE_CODE (type) == ENUMERAL_TYPE
3086 || TREE_CODE (type) == REAL_TYPE)
3087 ? TYPE_PRECISION (type) : POINTER_SIZE);
3090 /* Nonzero if integer constant C has a value that is permissible
3091 for type TYPE (an INTEGER_TYPE). */
3094 int_fits_type_p (c, type)
3097 if (TREE_UNSIGNED (type))
3098 return (!INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c)
3099 && !INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)));
3101 return (!INT_CST_LT (TYPE_MAX_VALUE (type), c)
3102 && !INT_CST_LT (c, TYPE_MIN_VALUE (type)));
3105 /* Return the innermost context enclosing DECL that is
3106 a FUNCTION_DECL, or zero if none. */
3109 decl_function_context (decl)
3114 if (TREE_CODE (decl) == ERROR_MARK)
3117 if (TREE_CODE (decl) == SAVE_EXPR)
3118 context = SAVE_EXPR_CONTEXT (decl);
3120 context = DECL_CONTEXT (decl);
3122 while (context && TREE_CODE (context) != FUNCTION_DECL)
3124 if (TREE_CODE (context) == RECORD_TYPE
3125 || TREE_CODE (context) == UNION_TYPE)
3126 context = TYPE_CONTEXT (context);
3127 else if (TREE_CODE (context) == TYPE_DECL)
3128 context = DECL_CONTEXT (context);
3129 else if (TREE_CODE (context) == BLOCK)
3130 context = BLOCK_SUPERCONTEXT (context);
3132 /* Unhandled CONTEXT !? */
3139 /* Return the innermost context enclosing DECL that is
3140 a RECORD_TYPE or UNION_TYPE, or zero if none.
3141 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
3144 decl_type_context (decl)
3147 tree context = DECL_CONTEXT (decl);
3151 if (TREE_CODE (context) == RECORD_TYPE
3152 || TREE_CODE (context) == UNION_TYPE)
3154 if (TREE_CODE (context) == TYPE_DECL
3155 || TREE_CODE (context) == FUNCTION_DECL)
3156 context = DECL_CONTEXT (context);
3157 else if (TREE_CODE (context) == BLOCK)
3158 context = BLOCK_SUPERCONTEXT (context);
3160 /* Unhandled CONTEXT!? */
3167 print_obstack_statistics (str, o)
3171 struct _obstack_chunk *chunk = o->chunk;
3178 n_alloc += chunk->limit - &chunk->contents[0];
3179 chunk = chunk->prev;
3181 fprintf (stderr, "obstack %s: %d bytes, %d chunks\n",
3182 str, n_alloc, n_chunks);
3185 dump_tree_statistics ()
3188 int total_nodes, total_bytes;
3190 fprintf (stderr, "\n??? tree nodes created\n\n");
3191 #ifdef GATHER_STATISTICS
3192 fprintf (stderr, "Kind Nodes Bytes\n");
3193 fprintf (stderr, "-------------------------------------\n");
3194 total_nodes = total_bytes = 0;
3195 for (i = 0; i < (int) all_kinds; i++)
3197 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
3198 tree_node_counts[i], tree_node_sizes[i]);
3199 total_nodes += tree_node_counts[i];
3200 total_bytes += tree_node_sizes[i];
3202 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
3203 fprintf (stderr, "-------------------------------------\n");
3204 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
3205 fprintf (stderr, "-------------------------------------\n");
3207 fprintf (stderr, "(No per-node statistics)\n");
3209 print_lang_statistics ();