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1.1 root 1: /* Language-independent node constructors for parse phase of GNU compiler.
2: Copyright (C) 1987, 1988, 1992 Free Software Foundation, Inc.
3:
4: This file is part of GNU CC.
5:
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)
9: any later version.
10:
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.
15:
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. */
19:
20:
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
26: nodes of that code.
27:
28: It is intended to be language-independent, but occasionally
29: calls language-dependent routines defined (for C) in typecheck.c.
30:
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. */
34:
35: #include "config.h"
36: #include <stdio.h>
37: #include "flags.h"
38: #include "function.h"
39: #include "tree.h"
40: #include "obstack.h"
41: #include "gvarargs.h"
42:
43: #define obstack_chunk_alloc xmalloc
44: #define obstack_chunk_free free
45:
46: extern int xmalloc ();
47: extern void free ();
48:
49: /* Tree nodes of permanent duration are allocated in this obstack.
50: They are the identifier nodes, and everything outside of
51: the bodies and parameters of function definitions. */
52:
53: struct obstack permanent_obstack;
54:
55: /* The initial RTL, and all ..._TYPE nodes, in a function
56: are allocated in this obstack. Usually they are freed at the
57: end of the function, but if the function is inline they are saved.
58: For top-level functions, this is maybepermanent_obstack.
59: Separate obstacks are made for nested functions. */
60:
61: struct obstack *function_maybepermanent_obstack;
62:
63: /* This is the function_maybepermanent_obstack for top-level functions. */
64:
65: struct obstack maybepermanent_obstack;
66:
67: /* The contents of the current function definition are allocated
68: in this obstack, and all are freed at the end of the function.
69: For top-level functions, this is temporary_obstack.
70: Separate obstacks are made for nested functions. */
71:
72: struct obstack *function_obstack;
73:
74: /* This is used for reading initializers of global variables. */
75:
76: struct obstack temporary_obstack;
77:
78: /* The tree nodes of an expression are allocated
79: in this obstack, and all are freed at the end of the expression. */
80:
81: struct obstack momentary_obstack;
82:
83: /* The tree nodes of a declarator are allocated
84: in this obstack, and all are freed when the declarator
85: has been parsed. */
86:
87: static struct obstack temp_decl_obstack;
88:
89: /* This points at either permanent_obstack
90: or the current function_maybepermanent_obstack. */
91:
92: struct obstack *saveable_obstack;
93:
94: /* This is same as saveable_obstack during parse and expansion phase;
95: it points to the current function's obstack during optimization.
96: This is the obstack to be used for creating rtl objects. */
97:
98: struct obstack *rtl_obstack;
99:
100: /* This points at either permanent_obstack or the current function_obstack. */
101:
102: struct obstack *current_obstack;
103:
104: /* This points at either permanent_obstack or the current function_obstack
105: or momentary_obstack. */
106:
107: struct obstack *expression_obstack;
108:
109: /* Stack of obstack selections for push_obstacks and pop_obstacks. */
110:
111: struct obstack_stack
112: {
113: struct obstack_stack *next;
114: struct obstack *current;
115: struct obstack *saveable;
116: struct obstack *expression;
117: struct obstack *rtl;
118: };
119:
120: struct obstack_stack *obstack_stack;
121:
122: /* Obstack for allocating struct obstack_stack entries. */
123:
124: static struct obstack obstack_stack_obstack;
125:
126: /* Addresses of first objects in some obstacks.
127: This is for freeing their entire contents. */
128: char *maybepermanent_firstobj;
129: char *temporary_firstobj;
130: char *momentary_firstobj;
131: char *temp_decl_firstobj;
132:
133: /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
134:
135: int all_types_permanent;
136:
137: /* Stack of places to restore the momentary obstack back to. */
138:
139: struct momentary_level
140: {
141: /* Pointer back to previous such level. */
142: struct momentary_level *prev;
143: /* First object allocated within this level. */
144: char *base;
145: /* Value of expression_obstack saved at entry to this level. */
146: struct obstack *obstack;
147: };
148:
149: struct momentary_level *momentary_stack;
150:
151: /* Table indexed by tree code giving a string containing a character
152: classifying the tree code. Possibilities are
153: t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
154:
155: #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
156:
157: char *standard_tree_code_type[] = {
158: #include "tree.def"
159: };
160: #undef DEFTREECODE
161:
162: /* Table indexed by tree code giving number of expression
163: operands beyond the fixed part of the node structure.
164: Not used for types or decls. */
165:
166: #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
167:
168: int standard_tree_code_length[] = {
169: #include "tree.def"
170: };
171: #undef DEFTREECODE
172:
173: /* Names of tree components.
174: Used for printing out the tree and error messages. */
175: #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
176:
177: char *standard_tree_code_name[] = {
178: #include "tree.def"
179: };
180: #undef DEFTREECODE
181:
182: /* Table indexed by tree code giving a string containing a character
183: classifying the tree code. Possibilities are
184: t, d, s, c, r, e, <, 1 and 2. See tree.def for details. */
185:
186: char **tree_code_type;
187:
188: /* Table indexed by tree code giving number of expression
189: operands beyond the fixed part of the node structure.
190: Not used for types or decls. */
191:
192: int *tree_code_length;
193:
194: /* Table indexed by tree code giving name of tree code, as a string. */
195:
196: char **tree_code_name;
197:
198: /* Statistics-gathering stuff. */
199: typedef enum
200: {
201: d_kind, t_kind, s_kind, r_kind, e_kind, c_kind,
202: id_kind, op_id_kind, perm_list_kind, temp_list_kind,
203: vec_kind, x_kind, lang_decl, lang_type, all_kinds
204: } tree_node_kind;
205: int tree_node_counts[(int)all_kinds];
206: int tree_node_sizes[(int)all_kinds];
207: int id_string_size = 0;
208: char *tree_node_kind_names[] = { "decls", "types", "stmts", "refs", "exprs", "constants",
209: "identifiers", "op_identifiers", "perm_tree_lists", "temp_tree_lists",
210: "vecs", "random kinds", "lang_decl kinds", "lang_type kinds" };
211:
212: /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
213:
214: #define MAX_HASH_TABLE 1009
215: static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
216:
217: /* 0 while creating built-in identifiers. */
218: static int do_identifier_warnings;
219:
220: extern char *mode_name[];
221:
222: void gcc_obstack_init ();
223: static tree stabilize_reference_1 ();
224:
225: /* Init the principal obstacks. */
226:
227: void
228: init_obstacks ()
229: {
230: gcc_obstack_init (&obstack_stack_obstack);
231: gcc_obstack_init (&permanent_obstack);
232:
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);
242:
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;
248:
249: /* Init the hash table of identifiers. */
250: bzero (hash_table, sizeof hash_table);
251: }
252:
253: void
254: gcc_obstack_init (obstack)
255: struct obstack *obstack;
256: {
257: /* Let particular systems override the size of a chunk. */
258: #ifndef OBSTACK_CHUNK_SIZE
259: #define OBSTACK_CHUNK_SIZE 0
260: #endif
261: /* Let them override the alloc and free routines too. */
262: #ifndef OBSTACK_CHUNK_ALLOC
263: #define OBSTACK_CHUNK_ALLOC xmalloc
264: #endif
265: #ifndef OBSTACK_CHUNK_FREE
266: #define OBSTACK_CHUNK_FREE free
267: #endif
268: _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
269: (void *(*) ()) OBSTACK_CHUNK_ALLOC,
270: (void (*) ()) OBSTACK_CHUNK_FREE);
271: }
272:
273: /* Save all variables describing the current status into the structure *P.
274: This is used before starting a nested function. */
275:
276: void
277: save_tree_status (p)
278: struct function *p;
279: {
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;
290:
291: function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
292: gcc_obstack_init (function_obstack);
293:
294: function_maybepermanent_obstack
295: = (struct obstack *) xmalloc (sizeof (struct obstack));
296: gcc_obstack_init (function_maybepermanent_obstack);
297:
298: current_obstack = &permanent_obstack;
299: expression_obstack = &permanent_obstack;
300: rtl_obstack = saveable_obstack = &permanent_obstack;
301:
302: momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
303: maybepermanent_firstobj
304: = (char *) obstack_finish (function_maybepermanent_obstack);
305: }
306:
307: /* Restore all variables describing the current status from the structure *P.
308: This is used after a nested function. */
309:
310: void
311: restore_tree_status (p)
312: struct function *p;
313: {
314: all_types_permanent = p->all_types_permanent;
315: momentary_stack = p->momentary_stack;
316:
317: obstack_free (&momentary_obstack, momentary_firstobj);
318: obstack_free (function_obstack, 0);
319: obstack_free (function_maybepermanent_obstack, 0);
320: free (function_obstack);
321:
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;
330: }
331:
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. */
336:
337: void
338: temporary_allocation ()
339: {
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;
345: momentary_stack = 0;
346: }
347:
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. */
351:
352: void
353: end_temporary_allocation ()
354: {
355: current_obstack = &permanent_obstack;
356: expression_obstack = &permanent_obstack;
357: rtl_obstack = saveable_obstack = &permanent_obstack;
358: }
359:
360: /* Resume allocating on the temporary obstack, undoing
361: effects of `end_temporary_allocation'. */
362:
363: void
364: resume_temporary_allocation ()
365: {
366: current_obstack = function_obstack;
367: expression_obstack = function_obstack;
368: rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
369: }
370:
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
374: allocation. */
375:
376: void
377: saveable_allocation ()
378: {
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;
382: }
383:
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. */
387:
388: void
389: push_obstacks (current, saveable)
390: struct obstack *current, *saveable;
391: {
392: struct obstack_stack *p
393: = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
394: (sizeof (struct obstack_stack)));
395:
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;
401: obstack_stack = p;
402:
403: current_obstack = current;
404: expression_obstack = current;
405: rtl_obstack = saveable_obstack = saveable;
406: }
407:
408: /* Save the current set of obstacks, but don't change them. */
409:
410: void
411: push_obstacks_nochange ()
412: {
413: struct obstack_stack *p
414: = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
415: (sizeof (struct obstack_stack)));
416:
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;
422: obstack_stack = p;
423: }
424:
425: /* Pop the obstack selection stack. */
426:
427: void
428: pop_obstacks ()
429: {
430: struct obstack_stack *p = obstack_stack;
431: obstack_stack = p->next;
432:
433: current_obstack = p->current;
434: saveable_obstack = p->saveable;
435: expression_obstack = p->expression;
436: rtl_obstack = p->rtl;
437:
438: obstack_free (&obstack_stack_obstack, p);
439: }
440:
441: /* Nonzero if temporary allocation is currently in effect.
442: Zero if currently doing permanent allocation. */
443:
444: int
445: allocation_temporary_p ()
446: {
447: return current_obstack != &permanent_obstack;
448: }
449:
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. */
453:
454: void
455: permanent_allocation ()
456: {
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);
462:
463: current_obstack = &permanent_obstack;
464: expression_obstack = &permanent_obstack;
465: rtl_obstack = saveable_obstack = &permanent_obstack;
466: }
467:
468: /* Save permanently everything on the maybepermanent_obstack. */
469:
470: void
471: preserve_data ()
472: {
473: maybepermanent_firstobj
474: = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
475: }
476:
477: void
478: preserve_initializer ()
479: {
480: temporary_firstobj
481: = (char *) obstack_alloc (&temporary_obstack, 0);
482: momentary_firstobj
483: = (char *) obstack_alloc (&momentary_obstack, 0);
484: maybepermanent_firstobj
485: = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
486: }
487:
488: /* Start allocating new rtl in current_obstack.
489: Use resume_temporary_allocation
490: to go back to allocating rtl in saveable_obstack. */
491:
492: void
493: rtl_in_current_obstack ()
494: {
495: rtl_obstack = current_obstack;
496: }
497:
498: /* Temporarily allocate rtl from saveable_obstack. Return 1 if we were
499: previously allocating it from current_obstack. */
500:
501: int
502: rtl_in_saveable_obstack ()
503: {
504: if (rtl_obstack == current_obstack)
505: {
506: rtl_obstack = saveable_obstack;
507: return 1;
508: }
509: else
510: return 0;
511: }
512:
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. */
516:
517: char *
518: oballoc (size)
519: int size;
520: {
521: return (char *) obstack_alloc (current_obstack, size);
522: }
523:
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. */
527:
528: void
529: obfree (ptr)
530: char *ptr;
531: {
532: obstack_free (current_obstack, ptr);
533: }
534:
535: /* Allocate SIZE bytes in the permanent obstack
536: and return a pointer to them. */
537:
538: char *
539: permalloc (size)
540: long size;
541: {
542: return (char *) obstack_alloc (&permanent_obstack, size);
543: }
544:
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. */
548:
549: char *
550: perm_calloc (nelem, size)
551: int nelem;
552: long size;
553: {
554: char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
555: bzero (rval, nelem * size);
556: return rval;
557: }
558:
559: /* Allocate SIZE bytes in the saveable obstack
560: and return a pointer to them. */
561:
562: char *
563: savealloc (size)
564: int size;
565: {
566: return (char *) obstack_alloc (saveable_obstack, size);
567: }
568:
569: /* Print out which obstack an object is in. */
570:
571: void
572: debug_obstack (object)
573: char *object;
574: {
575: struct obstack *obstack = NULL;
576: char *obstack_name = NULL;
577: struct function *p;
578:
579: for (p = outer_function_chain; p; p = p->next)
580: {
581: if (_obstack_allocated_p (p->function_obstack, object))
582: {
583: obstack = p->function_obstack;
584: obstack_name = "containing function obstack";
585: }
586: if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
587: {
588: obstack = p->function_maybepermanent_obstack;
589: obstack_name = "containing function maybepermanent obstack";
590: }
591: }
592:
593: if (_obstack_allocated_p (&obstack_stack_obstack, object))
594: {
595: obstack = &obstack_stack_obstack;
596: obstack_name = "obstack_stack_obstack";
597: }
598: else if (_obstack_allocated_p (function_obstack, object))
599: {
600: obstack = function_obstack;
601: obstack_name = "function obstack";
602: }
603: else if (_obstack_allocated_p (&permanent_obstack, object))
604: {
605: obstack = &permanent_obstack;
606: obstack_name = "permanent_obstack";
607: }
608: else if (_obstack_allocated_p (&momentary_obstack, object))
609: {
610: obstack = &momentary_obstack;
611: obstack_name = "momentary_obstack";
612: }
613: else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
614: {
615: obstack = function_maybepermanent_obstack;
616: obstack_name = "function maybepermanent obstack";
617: }
618: else if (_obstack_allocated_p (&temp_decl_obstack, object))
619: {
620: obstack = &temp_decl_obstack;
621: obstack_name = "temp_decl_obstack";
622: }
623:
624: /* Check to see if the object is in the free area of the obstack. */
625: if (obstack != NULL)
626: {
627: if (object >= obstack->next_free
628: && object < obstack->chunk_limit)
629: fprintf (stderr, "object in free portion of obstack %s.\n",
630: obstack_name);
631: else
632: fprintf (stderr, "object allocated from %s.\n", obstack_name);
633: }
634: else
635: fprintf (stderr, "object not allocated from any obstack.\n");
636: }
637:
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. */
641:
642: int
643: object_permanent_p (obj)
644: tree obj;
645: {
646: return _obstack_allocated_p (&permanent_obstack, obj);
647: }
648:
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. */
653:
654: void
655: push_momentary ()
656: {
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;
665: }
666:
667: /* Free all the storage in the current momentary-allocation level.
668: In C, this happens at the end of each statement. */
669:
670: void
671: clear_momentary ()
672: {
673: obstack_free (&momentary_obstack, momentary_stack->base);
674: }
675:
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. */
680:
681: void
682: pop_momentary ()
683: {
684: struct momentary_level *tem = momentary_stack;
685: momentary_stack = tem->prev;
686: expression_obstack = tem->obstack;
687: obstack_free (&momentary_obstack, tem);
688: }
689:
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. */
693:
694: int
695: suspend_momentary ()
696: {
697: register int tem = expression_obstack == &momentary_obstack;
698: expression_obstack = saveable_obstack;
699: return tem;
700: }
701:
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. */
706:
707: void
708: resume_momentary (yes)
709: int yes;
710: {
711: if (yes)
712: expression_obstack = &momentary_obstack;
713: }
714:
715: /* Init the tables indexed by tree code.
716: Note that languages can add to these tables to define their own codes. */
717:
718: void
719: init_tree_codes ()
720: {
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));
730: }
731:
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.
736:
737: Achoo! I got a code in the node. */
738:
739: tree
740: make_node (code)
741: enum tree_code code;
742: {
743: register tree t;
744: register int type = TREE_CODE_CLASS (code);
745: register int length;
746: register struct obstack *obstack = current_obstack;
747: register int i;
748: register tree_node_kind kind;
749:
750: switch (type)
751: {
752: case 'd': /* A decl node */
753: #ifdef GATHER_STATISTICS
754: kind = d_kind;
755: #endif
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;
765: break;
766:
767: case 't': /* a type node */
768: #ifdef GATHER_STATISTICS
769: kind = t_kind;
770: #endif
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;
775: break;
776:
777: case 's': /* an expression with side effects */
778: #ifdef GATHER_STATISTICS
779: kind = s_kind;
780: goto usual_kind;
781: #endif
782: case 'r': /* a reference */
783: #ifdef GATHER_STATISTICS
784: kind = r_kind;
785: goto usual_kind;
786: #endif
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
792: kind = e_kind;
793: usual_kind:
794: #endif
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 *);
803: break;
804:
805: case 'c': /* a constant */
806: #ifdef GATHER_STATISTICS
807: kind = c_kind;
808: #endif
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)
813: {
814: length = sizeof (struct tree_real_cst);
815: break;
816: }
817:
818: case 'x': /* something random, like an identifier. */
819: #ifdef GATHER_STATISTICS
820: if (code == IDENTIFIER_NODE)
821: kind = id_kind;
822: else if (code == OP_IDENTIFIER)
823: kind = op_id_kind;
824: else if (code == TREE_VEC)
825: kind = vec_kind;
826: else
827: kind = x_kind;
828: #endif
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;
834: }
835:
836: t = (tree) obstack_alloc (obstack, length);
837:
838: #ifdef GATHER_STATISTICS
839: tree_node_counts[(int)kind]++;
840: tree_node_sizes[(int)kind] += length;
841: #endif
842:
843: TREE_TYPE (t) = 0;
844: TREE_CHAIN (t) = 0;
845: for (i = (length / sizeof (int)) - 1;
846: i >= sizeof (struct tree_common) / sizeof (int) - 1;
847: i--)
848: ((int *) t)[i] = 0;
849:
850: TREE_SET_CODE (t, code);
851: if (obstack == &permanent_obstack)
852: TREE_PERMANENT (t) = 1;
853:
854: switch (type)
855: {
856: case 's':
857: TREE_SIDE_EFFECTS (t) = 1;
858: TREE_TYPE (t) = void_type_node;
859: break;
860:
861: case 'd':
862: DECL_ALIGN (t) = 1;
863: DECL_SOURCE_LINE (t) = lineno;
864: DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
865: break;
866:
867: case 't':
868: {
869: static unsigned next_type_uid = 1;
870:
871: TYPE_UID (t) = next_type_uid++;
872: }
873: TYPE_ALIGN (t) = 1;
874: TYPE_MAIN_VARIANT (t) = t;
875: break;
876:
877: case 'c':
878: TREE_CONSTANT (t) = 1;
879: break;
880: }
881:
882: return t;
883: }
884:
885: /* Return a new node with the same contents as NODE
886: except that its TREE_CHAIN is zero and it has a fresh uid. */
887:
888: tree
889: copy_node (node)
890: tree node;
891: {
892: register tree t;
893: register enum tree_code code = TREE_CODE (node);
894: register int length;
895: register int i;
896:
897: switch (TREE_CODE_CLASS (code))
898: {
899: case 'd': /* A decl node */
900: length = sizeof (struct tree_decl);
901: break;
902:
903: case 't': /* a type node */
904: length = sizeof (struct tree_type);
905: break;
906:
907: case 'r': /* a reference */
908: case 'e': /* a expression */
909: case 's': /* an expression with side effects */
910: case '<': /* a comparison expression */
911: case '1': /* a unary arithmetic expression */
912: case '2': /* a binary arithmetic expression */
913: length = sizeof (struct tree_exp)
914: + (tree_code_length[(int) code] - 1) * sizeof (char *);
915: break;
916:
917: case 'c': /* a constant */
918: /* We can't use tree_code_length for this, since the number of words
919: is machine-dependent due to varying alignment of `double'. */
920: if (code == REAL_CST)
921: {
922: length = sizeof (struct tree_real_cst);
923: break;
924: }
925:
926: case 'x': /* something random, like an identifier. */
927: length = sizeof (struct tree_common)
928: + tree_code_length[(int) code] * sizeof (char *);
929: if (code == TREE_VEC)
930: length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
931: }
932:
933: t = (tree) obstack_alloc (current_obstack, length);
934:
935: for (i = ((length + sizeof (int) - 1) / sizeof (int)) - 1;
936: i >= 0;
937: i--)
938: ((int *) t)[i] = ((int *) node)[i];
939:
940: TREE_CHAIN (t) = 0;
941:
942: TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
943:
944: return t;
945: }
946:
947: /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
948: For example, this can copy a list made of TREE_LIST nodes. */
949:
950: tree
951: copy_list (list)
952: tree list;
953: {
954: tree head;
955: register tree prev, next;
956:
957: if (list == 0)
958: return 0;
959:
960: head = prev = copy_node (list);
961: next = TREE_CHAIN (list);
962: while (next)
963: {
964: TREE_CHAIN (prev) = copy_node (next);
965: prev = TREE_CHAIN (prev);
966: next = TREE_CHAIN (next);
967: }
968: return head;
969: }
970:
971: #define HASHBITS 30
972:
973: /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
974: If an identifier with that name has previously been referred to,
975: the same node is returned this time. */
976:
977: tree
978: get_identifier (text)
979: register char *text;
980: {
981: register int hi;
982: register int i;
983: register tree idp;
984: register int len, hash_len;
985:
986: /* Compute length of text in len. */
987: for (len = 0; text[len]; len++);
988:
989: /* Decide how much of that length to hash on */
990: hash_len = len;
991: if (warn_id_clash && len > id_clash_len)
992: hash_len = id_clash_len;
993:
994: /* Compute hash code */
995: hi = hash_len * 613 + (unsigned)text[0];
996: for (i = 1; i < hash_len; i += 2)
997: hi = ((hi * 613) + (unsigned)(text[i]));
998:
999: hi &= (1 << HASHBITS) - 1;
1000: hi %= MAX_HASH_TABLE;
1001:
1002: /* Search table for identifier */
1003: for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1004: if (IDENTIFIER_LENGTH (idp) == len
1005: && IDENTIFIER_POINTER (idp)[0] == text[0]
1006: && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1007: return idp; /* <-- return if found */
1008:
1009: /* Not found; optionally warn about a similar identifier */
1010: if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1011: for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1012: if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1013: {
1014: warning ("`%s' and `%s' identical in first %d characters",
1015: IDENTIFIER_POINTER (idp), text, id_clash_len);
1016: break;
1017: }
1018:
1019: if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1020: abort (); /* set_identifier_size hasn't been called. */
1021:
1022: /* Not found, create one, add to chain */
1023: idp = make_node (IDENTIFIER_NODE);
1024: IDENTIFIER_LENGTH (idp) = len;
1025: #ifdef GATHER_STATISTICS
1026: id_string_size += len;
1027: #endif
1028:
1029: IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1030:
1031: TREE_CHAIN (idp) = hash_table[hi];
1032: hash_table[hi] = idp;
1033: return idp; /* <-- return if created */
1034: }
1035:
1036: /* Enable warnings on similar identifiers (if requested).
1037: Done after the built-in identifiers are created. */
1038:
1039: void
1040: start_identifier_warnings ()
1041: {
1042: do_identifier_warnings = 1;
1043: }
1044:
1045: /* Record the size of an identifier node for the language in use.
1046: SIZE is the total size in bytes.
1047: This is called by the language-specific files. This must be
1048: called before allocating any identifiers. */
1049:
1050: void
1051: set_identifier_size (size)
1052: int size;
1053: {
1054: tree_code_length[(int) IDENTIFIER_NODE]
1055: = (size - sizeof (struct tree_common)) / sizeof (tree);
1056: }
1057:
1058: /* Return a newly constructed INTEGER_CST node whose constant value
1059: is specified by the two ints LOW and HI.
1060: The TREE_TYPE is set to `int'. */
1061:
1062: tree
1063: build_int_2 (low, hi)
1064: int low, hi;
1065: {
1066: register tree t = make_node (INTEGER_CST);
1067: TREE_INT_CST_LOW (t) = low;
1068: TREE_INT_CST_HIGH (t) = hi;
1069: TREE_TYPE (t) = integer_type_node;
1070: return t;
1071: }
1072:
1073: /* Return a new REAL_CST node whose type is TYPE and value is D. */
1074:
1075: tree
1076: build_real (type, d)
1077: tree type;
1078: REAL_VALUE_TYPE d;
1079: {
1080: tree v;
1081:
1082: /* Check for valid float value for this type on this target machine;
1083: if not, can print error message and store a valid value in D. */
1084: #ifdef CHECK_FLOAT_VALUE
1085: CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1086: #endif
1087:
1088: v = make_node (REAL_CST);
1089: TREE_TYPE (v) = type;
1090: TREE_REAL_CST (v) = d;
1091: return v;
1092: }
1093:
1094: /* Return a new REAL_CST node whose type is TYPE
1095: and whose value is the integer value of the INTEGER_CST node I. */
1096:
1097: #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1098:
1099: REAL_VALUE_TYPE
1100: real_value_from_int_cst (i)
1101: tree i;
1102: {
1103: REAL_VALUE_TYPE d;
1104: #ifdef REAL_ARITHMETIC
1105: REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1106: #else /* not REAL_ARITHMETIC */
1107: if (TREE_INT_CST_HIGH (i) < 0)
1108: {
1109: d = (double) (~ TREE_INT_CST_HIGH (i));
1110: d *= ((double) (1 << (HOST_BITS_PER_INT / 2))
1111: * (double) (1 << (HOST_BITS_PER_INT / 2)));
1112: d += (double) (unsigned) (~ TREE_INT_CST_LOW (i));
1113: d = (- d - 1.0);
1114: }
1115: else
1116: {
1117: d = (double) TREE_INT_CST_HIGH (i);
1118: d *= ((double) (1 << (HOST_BITS_PER_INT / 2))
1119: * (double) (1 << (HOST_BITS_PER_INT / 2)));
1120: d += (double) (unsigned) TREE_INT_CST_LOW (i);
1121: }
1122: #endif /* not REAL_ARITHMETIC */
1123: return d;
1124: }
1125:
1126: /* This function can't be implemented if we can't do arithmetic
1127: on the float representation. */
1128:
1129: tree
1130: build_real_from_int_cst (type, i)
1131: tree type;
1132: tree i;
1133: {
1134: tree v;
1135: REAL_VALUE_TYPE d;
1136:
1137: v = make_node (REAL_CST);
1138: TREE_TYPE (v) = type;
1139:
1140: d = real_value_from_int_cst (i);
1141: /* Check for valid float value for this type on this target machine;
1142: if not, can print error message and store a valid value in D. */
1143: #ifdef CHECK_FLOAT_VALUE
1144: CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1145: #endif
1146:
1147: TREE_REAL_CST (v) = d;
1148: return v;
1149: }
1150:
1151: #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1152:
1153: /* Return a newly constructed STRING_CST node whose value is
1154: the LEN characters at STR.
1155: The TREE_TYPE is not initialized. */
1156:
1157: tree
1158: build_string (len, str)
1159: int len;
1160: char *str;
1161: {
1162: register tree s = make_node (STRING_CST);
1163: TREE_STRING_LENGTH (s) = len;
1164: TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1165: return s;
1166: }
1167:
1168: /* Return a newly constructed COMPLEX_CST node whose value is
1169: specified by the real and imaginary parts REAL and IMAG.
1170: Both REAL and IMAG should be constant nodes.
1171: The TREE_TYPE is not initialized. */
1172:
1173: tree
1174: build_complex (real, imag)
1175: tree real, imag;
1176: {
1177: register tree t = make_node (COMPLEX_CST);
1178: TREE_REALPART (t) = real;
1179: TREE_IMAGPART (t) = imag;
1180: return t;
1181: }
1182:
1183: /* Build a newly constructed TREE_VEC node of length LEN. */
1184: tree
1185: make_tree_vec (len)
1186: int len;
1187: {
1188: register tree t;
1189: register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1190: register struct obstack *obstack = current_obstack;
1191: register int i;
1192:
1193: #ifdef GATHER_STATISTICS
1194: tree_node_counts[(int)vec_kind]++;
1195: tree_node_sizes[(int)vec_kind] += length;
1196: #endif
1197:
1198: t = (tree) obstack_alloc (obstack, length);
1199:
1200: TREE_TYPE (t) = 0;
1201: TREE_CHAIN (t) = 0;
1202: for (i = (length / sizeof (int)) - 1;
1203: i >= sizeof (struct tree_common) / sizeof (int) - 1;
1204: i--)
1205: ((int *) t)[i] = 0;
1206: TREE_SET_CODE (t, TREE_VEC);
1207: TREE_VEC_LENGTH (t) = len;
1208: if (obstack == &permanent_obstack)
1209: TREE_PERMANENT (t) = 1;
1210:
1211: return t;
1212: }
1213:
1214: /* Return 1 if EXPR is the integer constant zero. */
1215:
1216: int
1217: integer_zerop (expr)
1218: tree expr;
1219: {
1220: while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1221: expr = TREE_OPERAND (expr, 0);
1222:
1223: return (TREE_CODE (expr) == INTEGER_CST
1224: && TREE_INT_CST_LOW (expr) == 0
1225: && TREE_INT_CST_HIGH (expr) == 0);
1226: }
1227:
1228: /* Return 1 if EXPR is the integer constant one. */
1229:
1230: int
1231: integer_onep (expr)
1232: tree expr;
1233: {
1234: while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1235: expr = TREE_OPERAND (expr, 0);
1236:
1237: return (TREE_CODE (expr) == INTEGER_CST
1238: && TREE_INT_CST_LOW (expr) == 1
1239: && TREE_INT_CST_HIGH (expr) == 0);
1240: }
1241:
1242: /* Return 1 if EXPR is an integer containing all 1's
1243: in as much precision as it contains. */
1244:
1245: int
1246: integer_all_onesp (expr)
1247: tree expr;
1248: {
1249: register int prec;
1250: register int uns;
1251:
1252: while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1253: expr = TREE_OPERAND (expr, 0);
1254:
1255: if (TREE_CODE (expr) != INTEGER_CST)
1256: return 0;
1257:
1258: uns = TREE_UNSIGNED (TREE_TYPE (expr));
1259: if (!uns)
1260: return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1261:
1262: prec = TYPE_PRECISION (TREE_TYPE (expr));
1263: if (prec >= HOST_BITS_PER_INT)
1264: {
1265: int high_value, shift_amount;
1266:
1267: shift_amount = prec - HOST_BITS_PER_INT;
1268:
1269: if (shift_amount > HOST_BITS_PER_INT)
1270: /* Can not handle precisions greater than twice the host int size. */
1271: abort ();
1272: else if (shift_amount == HOST_BITS_PER_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. */
1275: high_value = -1;
1276: else
1277: high_value = (1 << shift_amount) - 1;
1278:
1279: return TREE_INT_CST_LOW (expr) == -1
1280: && TREE_INT_CST_HIGH (expr) == high_value;
1281: }
1282: else
1283: return TREE_INT_CST_LOW (expr) == (1 << prec) - 1;
1284: }
1285:
1286: /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1287: one bit on). */
1288:
1289: int
1290: integer_pow2p (expr)
1291: tree expr;
1292: {
1293: int high, low;
1294:
1295: while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1296: expr = TREE_OPERAND (expr, 0);
1297:
1298: if (TREE_CODE (expr) != INTEGER_CST)
1299: return 0;
1300:
1301: high = TREE_INT_CST_HIGH (expr);
1302: low = TREE_INT_CST_LOW (expr);
1303:
1304: if (high == 0 && low == 0)
1305: return 0;
1306:
1307: return ((high == 0 && (low & (low - 1)) == 0)
1308: || (low == 0 && (high & (high - 1)) == 0));
1309: }
1310:
1311: /* Return 1 if EXPR is the real constant zero. */
1312:
1313: int
1314: real_zerop (expr)
1315: tree expr;
1316: {
1317: while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1318: expr = TREE_OPERAND (expr, 0);
1319:
1320: return (TREE_CODE (expr) == REAL_CST
1321: && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0));
1322: }
1323:
1324: /* Return 1 if EXPR is the real constant one. */
1325:
1326: int
1327: real_onep (expr)
1328: tree expr;
1329: {
1330: while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1331: expr = TREE_OPERAND (expr, 0);
1332:
1333: return (TREE_CODE (expr) == REAL_CST
1334: && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1));
1335: }
1336:
1337: /* Return 1 if EXPR is the real constant two. */
1338:
1339: int
1340: real_twop (expr)
1341: tree expr;
1342: {
1343: while (TREE_CODE (expr) == NON_LVALUE_EXPR)
1344: expr = TREE_OPERAND (expr, 0);
1345:
1346: return (TREE_CODE (expr) == REAL_CST
1347: && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2));
1348: }
1349:
1350: /* Nonzero if EXP is a constant or a cast of a constant. */
1351:
1352: int
1353: really_constant_p (exp)
1354: tree exp;
1355: {
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);
1361: }
1362:
1363: /* Return first list element whose TREE_VALUE is ELEM.
1364: Return 0 if ELEM is not it LIST. */
1365:
1366: tree
1367: value_member (elem, list)
1368: tree elem, list;
1369: {
1370: while (list)
1371: {
1372: if (elem == TREE_VALUE (list))
1373: return list;
1374: list = TREE_CHAIN (list);
1375: }
1376: return NULL_TREE;
1377: }
1378:
1379: /* Return first list element whose TREE_PURPOSE is ELEM.
1380: Return 0 if ELEM is not it LIST. */
1381:
1382: tree
1383: purpose_member (elem, list)
1384: tree elem, list;
1385: {
1386: while (list)
1387: {
1388: if (elem == TREE_PURPOSE (list))
1389: return list;
1390: list = TREE_CHAIN (list);
1391: }
1392: return NULL_TREE;
1393: }
1394:
1395: /* Return first list element whose BINFO_TYPE is ELEM.
1396: Return 0 if ELEM is not it LIST. */
1397:
1398: tree
1399: binfo_member (elem, list)
1400: tree elem, list;
1401: {
1402: while (list)
1403: {
1404: if (elem == BINFO_TYPE (list))
1405: return list;
1406: list = TREE_CHAIN (list);
1407: }
1408: return NULL_TREE;
1409: }
1410:
1411: /* Return nonzero if ELEM is part of the chain CHAIN. */
1412:
1413: int
1414: chain_member (elem, chain)
1415: tree elem, chain;
1416: {
1417: while (chain)
1418: {
1419: if (elem == chain)
1420: return 1;
1421: chain = TREE_CHAIN (chain);
1422: }
1423:
1424: return 0;
1425: }
1426:
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'. */
1430:
1431: int
1432: list_length (t)
1433: tree t;
1434: {
1435: register tree tail;
1436: register int len = 0;
1437:
1438: for (tail = t; tail; tail = TREE_CHAIN (tail))
1439: len++;
1440:
1441: return len;
1442: }
1443:
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'. */
1447:
1448: tree
1449: chainon (op1, op2)
1450: tree op1, op2;
1451: {
1452: tree t;
1453:
1454: if (op1)
1455: {
1456: for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t))
1457: if (t == op2) abort (); /* Circularity being created */
1458: TREE_CHAIN (t) = op2;
1459: return op1;
1460: }
1461: else return op2;
1462: }
1463:
1464: /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1465:
1466: tree
1467: tree_last (chain)
1468: register tree chain;
1469: {
1470: register tree next;
1471: if (chain)
1472: while (next = TREE_CHAIN (chain))
1473: chain = next;
1474: return chain;
1475: }
1476:
1477: /* Reverse the order of elements in the chain T,
1478: and return the new head of the chain (old last element). */
1479:
1480: tree
1481: nreverse (t)
1482: tree t;
1483: {
1484: register tree prev = 0, decl, next;
1485: for (decl = t; decl; decl = next)
1486: {
1487: next = TREE_CHAIN (decl);
1488: TREE_CHAIN (decl) = prev;
1489: prev = decl;
1490: }
1491: return prev;
1492: }
1493:
1494: /* Given a chain CHAIN of tree nodes,
1495: construct and return a list of those nodes. */
1496:
1497: tree
1498: listify (chain)
1499: tree chain;
1500: {
1501: tree result = NULL_TREE;
1502: tree in_tail = chain;
1503: tree out_tail = NULL_TREE;
1504:
1505: while (in_tail)
1506: {
1507: tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1508: if (out_tail)
1509: TREE_CHAIN (out_tail) = next;
1510: else
1511: result = next;
1512: out_tail = next;
1513: in_tail = TREE_CHAIN (in_tail);
1514: }
1515:
1516: return result;
1517: }
1518:
1519: /* Return a newly created TREE_LIST node whose
1520: purpose and value fields are PARM and VALUE. */
1521:
1522: tree
1523: build_tree_list (parm, value)
1524: tree parm, value;
1525: {
1526: register tree t = make_node (TREE_LIST);
1527: TREE_PURPOSE (t) = parm;
1528: TREE_VALUE (t) = value;
1529: return t;
1530: }
1531:
1532: /* Similar, but build on the temp_decl_obstack. */
1533:
1534: tree
1535: build_decl_list (parm, value)
1536: tree parm, value;
1537: {
1538: register tree node;
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;
1543: return node;
1544: }
1545:
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. */
1549:
1550: tree
1551: tree_cons (purpose, value, chain)
1552: tree purpose, value, chain;
1553: {
1554: #if 0
1555: register tree node = make_node (TREE_LIST);
1556: #else
1557: register int i;
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);
1562: #endif
1563:
1564: ((int *)node)[(sizeof (struct tree_common)/sizeof (int)) - 1] = 0;
1565: TREE_SET_CODE (node, TREE_LIST);
1566: if (current_obstack == &permanent_obstack)
1567: TREE_PERMANENT (node) = 1;
1568: TREE_TYPE (node) = 0;
1569: #endif
1570:
1571: TREE_CHAIN (node) = chain;
1572: TREE_PURPOSE (node) = purpose;
1573: TREE_VALUE (node) = value;
1574: return node;
1575: }
1576:
1577: /* Similar, but build on the temp_decl_obstack. */
1578:
1579: tree
1580: decl_tree_cons (purpose, value, chain)
1581: tree purpose, value, chain;
1582: {
1583: register tree node;
1584: register struct obstack *ambient_obstack = current_obstack;
1585: current_obstack = &temp_decl_obstack;
1586: node = tree_cons (purpose, value, chain);
1587: current_obstack = ambient_obstack;
1588: return node;
1589: }
1590:
1591: /* Same as `tree_cons' but make a permanent object. */
1592:
1593: tree
1594: perm_tree_cons (purpose, value, chain)
1595: tree purpose, value, chain;
1596: {
1597: register tree node;
1598: register struct obstack *ambient_obstack = current_obstack;
1599: current_obstack = &permanent_obstack;
1600:
1601: node = tree_cons (purpose, value, chain);
1602: current_obstack = ambient_obstack;
1603: return node;
1604: }
1605:
1606: /* Same as `tree_cons', but make this node temporary, regardless. */
1607:
1608: tree
1609: temp_tree_cons (purpose, value, chain)
1610: tree purpose, value, chain;
1611: {
1612: register tree node;
1613: register struct obstack *ambient_obstack = current_obstack;
1614: current_obstack = &temporary_obstack;
1615:
1616: node = tree_cons (purpose, value, chain);
1617: current_obstack = ambient_obstack;
1618: return node;
1619: }
1620:
1621: /* Same as `tree_cons', but save this node if the function's RTL is saved. */
1622:
1623: tree
1624: saveable_tree_cons (purpose, value, chain)
1625: tree purpose, value, chain;
1626: {
1627: register tree node;
1628: register struct obstack *ambient_obstack = current_obstack;
1629: current_obstack = saveable_obstack;
1630:
1631: node = tree_cons (purpose, value, chain);
1632: current_obstack = ambient_obstack;
1633: return node;
1634: }
1635:
1636: /* Return the size nominally occupied by an object of type TYPE
1637: when it resides in memory. The value is measured in units of bytes,
1638: and its data type is that normally used for type sizes
1639: (which is the first type created by make_signed_type or
1640: make_unsigned_type). */
1641:
1642: tree
1643: size_in_bytes (type)
1644: tree type;
1645: {
1646: if (type == error_mark_node)
1647: return integer_zero_node;
1648: type = TYPE_MAIN_VARIANT (type);
1649: if (TYPE_SIZE (type) == 0)
1650: {
1651: incomplete_type_error (0, type);
1652: return integer_zero_node;
1653: }
1654: return size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1655: size_int (BITS_PER_UNIT));
1656: }
1657:
1658: /* Return the size of TYPE (in bytes) as an integer,
1659: or return -1 if the size can vary. */
1660:
1661: int
1662: int_size_in_bytes (type)
1663: tree type;
1664: {
1665: int size;
1666: if (type == error_mark_node)
1667: return 0;
1668: type = TYPE_MAIN_VARIANT (type);
1669: if (TYPE_SIZE (type) == 0)
1670: return -1;
1671: if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1672: return -1;
1673: size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1674: return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1675: }
1676:
1677: /* Return, as an INTEGER_CST node, the number of elements for
1678: TYPE (which is an ARRAY_TYPE). */
1679:
1680: tree
1681: array_type_nelts (type)
1682: tree type;
1683: {
1684: tree index_type = TYPE_DOMAIN (type);
1685: return (tree_int_cst_equal (TYPE_MIN_VALUE (index_type), integer_zero_node)
1686: ? TYPE_MAX_VALUE (index_type)
1687: : fold (build (MINUS_EXPR, integer_type_node,
1688: TYPE_MAX_VALUE (index_type),
1689: TYPE_MIN_VALUE (index_type))));
1690: }
1691:
1692: /* Return nonzero if arg is static -- a reference to an object in
1693: static storage. This is not the same as the C meaning of `static'. */
1694:
1695: int
1696: staticp (arg)
1697: tree arg;
1698: {
1699: switch (TREE_CODE (arg))
1700: {
1701: case VAR_DECL:
1702: case FUNCTION_DECL:
1703: case CONSTRUCTOR:
1704: return TREE_STATIC (arg) || TREE_EXTERNAL (arg);
1705:
1706: case STRING_CST:
1707: return 1;
1708:
1709: case COMPONENT_REF:
1710: case BIT_FIELD_REF:
1711: return staticp (TREE_OPERAND (arg, 0));
1712:
1713: case INDIRECT_REF:
1714: return TREE_CONSTANT (TREE_OPERAND (arg, 0));
1715:
1716: case ARRAY_REF:
1717: if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1718: && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1719: return staticp (TREE_OPERAND (arg, 0));
1720: }
1721:
1722: return 0;
1723: }
1724:
1725: /* This should be applied to any node which may be used in more than one place,
1726: but must be evaluated only once. Normally, the code generator would
1727: reevaluate the node each time; this forces it to compute it once and save
1728: the result. This is done by encapsulating the node in a SAVE_EXPR. */
1729:
1730: tree
1731: save_expr (expr)
1732: tree expr;
1733: {
1734: register tree t = fold (expr);
1735:
1736: /* We don't care about whether this can be used as an lvalue in this
1737: context. */
1738: while (TREE_CODE (t) == NON_LVALUE_EXPR)
1739: t = TREE_OPERAND (t, 0);
1740:
1741: /* If the tree evaluates to a constant, then we don't want to hide that
1742: fact (i.e. this allows further folding, and direct checks for constants).
1743: Since it is no problem to reevaluate literals, we just return the
1744: literal node. */
1745:
1746: if (TREE_CONSTANT (t) || TREE_READONLY (t) || TREE_CODE (t) == SAVE_EXPR)
1747: return t;
1748:
1749: t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL);
1750:
1751: /* This expression might be placed ahead of a jump to ensure that the
1752: value was computed on both sides of the jump. So make sure it isn't
1753: eliminated as dead. */
1754: TREE_SIDE_EFFECTS (t) = 1;
1755: return t;
1756: }
1757:
1758: /* Stabilize a reference so that we can use it any number of times
1759: without causing its operands to be evaluated more than once.
1760: Returns the stabilized reference.
1761:
1762: Also allows conversion expressions whose operands are references.
1763: Any other kind of expression is returned unchanged. */
1764:
1765: tree
1766: stabilize_reference (ref)
1767: tree ref;
1768: {
1769: register tree result;
1770: register enum tree_code code = TREE_CODE (ref);
1771:
1772: switch (code)
1773: {
1774: case VAR_DECL:
1775: case PARM_DECL:
1776: case RESULT_DECL:
1777: /* No action is needed in this case. */
1778: return ref;
1779:
1780: case NOP_EXPR:
1781: case CONVERT_EXPR:
1782: case FLOAT_EXPR:
1783: case FIX_TRUNC_EXPR:
1784: case FIX_FLOOR_EXPR:
1785: case FIX_ROUND_EXPR:
1786: case FIX_CEIL_EXPR:
1787: result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
1788: break;
1789:
1790: case INDIRECT_REF:
1791: result = build_nt (INDIRECT_REF,
1792: stabilize_reference_1 (TREE_OPERAND (ref, 0)));
1793: break;
1794:
1795: case COMPONENT_REF:
1796: result = build_nt (COMPONENT_REF,
1797: stabilize_reference (TREE_OPERAND (ref, 0)),
1798: TREE_OPERAND (ref, 1));
1799: break;
1800:
1801: case BIT_FIELD_REF:
1802: result = build_nt (BIT_FIELD_REF,
1803: stabilize_reference (TREE_OPERAND (ref, 0)),
1804: stabilize_reference_1 (TREE_OPERAND (ref, 1)),
1805: stabilize_reference_1 (TREE_OPERAND (ref, 2)));
1806: break;
1807:
1808: case ARRAY_REF:
1809: result = build_nt (ARRAY_REF,
1810: stabilize_reference (TREE_OPERAND (ref, 0)),
1811: stabilize_reference_1 (TREE_OPERAND (ref, 1)));
1812: break;
1813:
1814: /* If arg isn't a kind of lvalue we recognize, make no change.
1815: Caller should recognize the error for an invalid lvalue. */
1816: default:
1817: return ref;
1818:
1819: case ERROR_MARK:
1820: return error_mark_node;
1821: }
1822:
1823: TREE_TYPE (result) = TREE_TYPE (ref);
1824: TREE_READONLY (result) = TREE_READONLY (ref);
1825: TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
1826: TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
1827: TREE_RAISES (result) = TREE_RAISES (ref);
1828:
1829: return result;
1830: }
1831:
1832: /* Subroutine of stabilize_reference; this is called for subtrees of
1833: references. Any expression with side-effects must be put in a SAVE_EXPR
1834: to ensure that it is only evaluated once.
1835:
1836: We don't put SAVE_EXPR nodes around everything, because assigning very
1837: simple expressions to temporaries causes us to miss good opportunities
1838: for optimizations. Among other things, the opportunity to fold in the
1839: addition of a constant into an addressing mode often gets lost, e.g.
1840: "y[i+1] += x;". In general, we take the approach that we should not make
1841: an assignment unless we are forced into it - i.e., that any non-side effect
1842: operator should be allowed, and that cse should take care of coalescing
1843: multiple utterances of the same expression should that prove fruitful. */
1844:
1845: static tree
1846: stabilize_reference_1 (e)
1847: tree e;
1848: {
1849: register tree result;
1850: register int length;
1851: register enum tree_code code = TREE_CODE (e);
1852:
1853: if (TREE_CONSTANT (e) || TREE_READONLY (e) || code == SAVE_EXPR)
1854: return e;
1855:
1856: switch (TREE_CODE_CLASS (code))
1857: {
1858: case 'x':
1859: case 't':
1860: case 'd':
1861: case '<':
1862: case 's':
1863: case 'e':
1864: case 'r':
1865: /* If the expression has side-effects, then encase it in a SAVE_EXPR
1866: so that it will only be evaluated once. */
1867: /* The reference (r) and comparison (<) classes could be handled as
1868: below, but it is generally faster to only evaluate them once. */
1869: if (TREE_SIDE_EFFECTS (e))
1870: return save_expr (e);
1871: return e;
1872:
1873: case 'c':
1874: /* Constants need no processing. In fact, we should never reach
1875: here. */
1876: return e;
1877:
1878: case '2':
1879: /* Recursively stabilize each operand. */
1880: result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
1881: stabilize_reference_1 (TREE_OPERAND (e, 1)));
1882: break;
1883:
1884: case '1':
1885: /* Recursively stabilize each operand. */
1886: result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
1887: break;
1888: }
1889:
1890: TREE_TYPE (result) = TREE_TYPE (e);
1891: TREE_READONLY (result) = TREE_READONLY (e);
1892: TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
1893: TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
1894: TREE_RAISES (result) = TREE_RAISES (e);
1895:
1896: return result;
1897: }
1898:
1899: /* Low-level constructors for expressions. */
1900:
1901: /* Build an expression of code CODE, data type TYPE,
1902: and operands as specified by the arguments ARG1 and following arguments.
1903: Expressions and reference nodes can be created this way.
1904: Constants, decls, types and misc nodes cannot be. */
1905:
1906: tree
1907: build (va_alist)
1908: va_dcl
1909: {
1910: va_list p;
1911: enum tree_code code;
1912: register tree t;
1913: register int length;
1914: register int i;
1915:
1916: va_start (p);
1917:
1918: code = va_arg (p, enum tree_code);
1919: t = make_node (code);
1920: length = tree_code_length[(int) code];
1921: TREE_TYPE (t) = va_arg (p, tree);
1922:
1923: if (length == 2)
1924: {
1925: /* This is equivalent to the loop below, but faster. */
1926: register tree arg0 = va_arg (p, tree);
1927: register tree arg1 = va_arg (p, tree);
1928: TREE_OPERAND (t, 0) = arg0;
1929: TREE_OPERAND (t, 1) = arg1;
1930: if ((arg0 && TREE_SIDE_EFFECTS (arg0))
1931: || (arg1 && TREE_SIDE_EFFECTS (arg1)))
1932: TREE_SIDE_EFFECTS (t) = 1;
1933: TREE_RAISES (t)
1934: = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
1935: }
1936: else if (length == 1)
1937: {
1938: register tree arg0 = va_arg (p, tree);
1939:
1940: /* Call build1 for this! */
1941: if (TREE_CODE_CLASS (code) != 's')
1942: abort ();
1943: TREE_OPERAND (t, 0) = arg0;
1944: if (arg0 && TREE_SIDE_EFFECTS (arg0))
1945: TREE_SIDE_EFFECTS (t) = 1;
1946: TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
1947: }
1948: else
1949: {
1950: for (i = 0; i < length; i++)
1951: {
1952: register tree operand = va_arg (p, tree);
1953: TREE_OPERAND (t, i) = operand;
1954: if (operand)
1955: {
1956: if (TREE_SIDE_EFFECTS (operand))
1957: TREE_SIDE_EFFECTS (t) = 1;
1958: if (TREE_RAISES (operand))
1959: TREE_RAISES (t) = 1;
1960: }
1961: }
1962: }
1963: va_end (p);
1964: return t;
1965: }
1966:
1967: /* Same as above, but only builds for unary operators.
1968: Saves lions share of calls to `build'; cuts down use
1969: of varargs, which is expensive for RISC machines. */
1970: tree
1971: build1 (code, type, node)
1972: enum tree_code code;
1973: tree type;
1974: tree node;
1975: {
1976: register struct obstack *obstack = current_obstack;
1977: register int i, length;
1978: register tree_node_kind kind;
1979: register tree t;
1980:
1981: #ifdef GATHER_STATISTICS
1982: if (TREE_CODE_CLASS (code) == 'r')
1983: kind = r_kind;
1984: else
1985: kind = e_kind;
1986: #endif
1987:
1988: obstack = expression_obstack;
1989: length = sizeof (struct tree_exp);
1990:
1991: t = (tree) obstack_alloc (obstack, length);
1992:
1993: #ifdef GATHER_STATISTICS
1994: tree_node_counts[(int)kind]++;
1995: tree_node_sizes[(int)kind] += length;
1996: #endif
1997:
1998: TREE_TYPE (t) = type;
1999: TREE_CHAIN (t) = 0;
2000:
2001: for (i = (length / sizeof (int)) - 2;
2002: i >= sizeof (struct tree_common) / sizeof (int) - 1;
2003: i--)
2004: ((int *) t)[i] = 0;
2005: TREE_SET_CODE (t, code);
2006:
2007: if (obstack == &permanent_obstack)
2008: TREE_PERMANENT (t) = 1;
2009:
2010: TREE_OPERAND (t, 0) = node;
2011: if (node)
2012: {
2013: if (TREE_SIDE_EFFECTS (node))
2014: TREE_SIDE_EFFECTS (t) = 1;
2015: if (TREE_RAISES (node))
2016: TREE_RAISES (t) = 1;
2017: }
2018:
2019: return t;
2020: }
2021:
2022: /* Similar except don't specify the TREE_TYPE
2023: and leave the TREE_SIDE_EFFECTS as 0.
2024: It is permissible for arguments to be null,
2025: or even garbage if their values do not matter. */
2026:
2027: tree
2028: build_nt (va_alist)
2029: va_dcl
2030: {
2031: va_list p;
2032: register enum tree_code code;
2033: register tree t;
2034: register int length;
2035: register int i;
2036:
2037: va_start (p);
2038:
2039: code = va_arg (p, enum tree_code);
2040: t = make_node (code);
2041: length = tree_code_length[(int) code];
2042:
2043: for (i = 0; i < length; i++)
2044: TREE_OPERAND (t, i) = va_arg (p, tree);
2045:
2046: va_end (p);
2047: return t;
2048: }
2049:
2050: /* Similar to `build_nt', except we build
2051: on the temp_decl_obstack, regardless. */
2052:
2053: tree
2054: build_parse_node (va_alist)
2055: va_dcl
2056: {
2057: register struct obstack *ambient_obstack = expression_obstack;
2058: va_list p;
2059: register enum tree_code code;
2060: register tree t;
2061: register int length;
2062: register int i;
2063:
2064: expression_obstack = &temp_decl_obstack;
2065:
2066: va_start (p);
2067:
2068: code = va_arg (p, enum tree_code);
2069: t = make_node (code);
2070: length = tree_code_length[(int) code];
2071:
2072: for (i = 0; i < length; i++)
2073: TREE_OPERAND (t, i) = va_arg (p, tree);
2074:
2075: va_end (p);
2076: expression_obstack = ambient_obstack;
2077: return t;
2078: }
2079:
2080: #if 0
2081: /* Commented out because this wants to be done very
2082: differently. See cp-lex.c. */
2083: tree
2084: build_op_identifier (op1, op2)
2085: tree op1, op2;
2086: {
2087: register tree t = make_node (OP_IDENTIFIER);
2088: TREE_PURPOSE (t) = op1;
2089: TREE_VALUE (t) = op2;
2090: return t;
2091: }
2092: #endif
2093:
2094: /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
2095: We do NOT enter this node in any sort of symbol table.
2096:
2097: layout_decl is used to set up the decl's storage layout.
2098: Other slots are initialized to 0 or null pointers. */
2099:
2100: tree
2101: build_decl (code, name, type)
2102: enum tree_code code;
2103: tree name, type;
2104: {
2105: register tree t;
2106:
2107: t = make_node (code);
2108:
2109: /* if (type == error_mark_node)
2110: type = integer_type_node; */
2111: /* That is not done, deliberately, so that having error_mark_node
2112: as the type can suppress useless errors in the use of this variable. */
2113:
2114: DECL_NAME (t) = name;
2115: DECL_ASSEMBLER_NAME (t) = name;
2116: TREE_TYPE (t) = type;
2117:
2118: if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
2119: layout_decl (t, 0);
2120: else if (code == FUNCTION_DECL)
2121: DECL_MODE (t) = FUNCTION_MODE;
2122:
2123: return t;
2124: }
2125:
2126: /* BLOCK nodes are used to represent the structure of binding contours
2127: and declarations, once those contours have been exited and their contents
2128: compiled. This information is used for outputting debugging info.
2129: A BLOCK may have a "controller" which is a BIND_EXPR node.
2130: Then the BLOCK is ignored unless the controller has the TREE_USED flag. */
2131:
2132: tree
2133: build_block (vars, tags, subblocks, supercontext, chain)
2134: tree vars, tags, subblocks, supercontext, chain;
2135: {
2136: register tree block = make_node (BLOCK);
2137: BLOCK_VARS (block) = vars;
2138: BLOCK_TYPE_TAGS (block) = tags;
2139: BLOCK_SUBBLOCKS (block) = subblocks;
2140: BLOCK_SUPERCONTEXT (block) = supercontext;
2141: BLOCK_CHAIN (block) = chain;
2142: return block;
2143: }
2144:
2145: /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
2146: and its TYPE_VOLATILE is VOLATILEP.
2147:
2148: Such variant types already made are recorded so that duplicates
2149: are not made.
2150:
2151: A variant types should never be used as the type of an expression.
2152: Always copy the variant information into the TREE_READONLY
2153: and TREE_THIS_VOLATILE of the expression, and then give the expression
2154: as its type the "main variant", the variant whose TYPE_READONLY
2155: and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
2156: main variant. */
2157:
2158: tree
2159: build_type_variant (type, constp, volatilep)
2160: tree type;
2161: int constp, volatilep;
2162: {
2163: register tree t, m = TYPE_MAIN_VARIANT (type);
2164: register struct obstack *ambient_obstack = current_obstack;
2165:
2166: /* Treat any nonzero argument as 1. */
2167: constp = !!constp;
2168: volatilep = !!volatilep;
2169:
2170: /* If not generating auxilliary info, search the chain of variants to see
2171: if there is already one there just like the one we need to have. If so,
2172: use that existing one.
2173:
2174: We don't do this in the case where we are generating aux info because
2175: in that case we want each typedef names to get it's own distinct type
2176: node, even if the type of this new typedef is the same as some other
2177: (existing) type. */
2178:
2179: if (!flag_gen_aux_info)
2180: for (t = m; t; t = TYPE_NEXT_VARIANT (t))
2181: if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t))
2182: return t;
2183:
2184: /* We need a new one. */
2185: current_obstack
2186: = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2187:
2188: t = copy_node (type);
2189: TYPE_READONLY (t) = constp;
2190: TYPE_VOLATILE (t) = volatilep;
2191: TYPE_POINTER_TO (t) = 0;
2192: TYPE_REFERENCE_TO (t) = 0;
2193:
2194: /* Add this type to the chain of variants of TYPE. */
2195: TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2196: TYPE_NEXT_VARIANT (m) = t;
2197:
2198: current_obstack = ambient_obstack;
2199: return t;
2200: }
2201:
2202: /* Hashing of types so that we don't make duplicates.
2203: The entry point is `type_hash_canon'. */
2204:
2205: /* Each hash table slot is a bucket containing a chain
2206: of these structures. */
2207:
2208: struct type_hash
2209: {
2210: struct type_hash *next; /* Next structure in the bucket. */
2211: int hashcode; /* Hash code of this type. */
2212: tree type; /* The type recorded here. */
2213: };
2214:
2215: /* Now here is the hash table. When recording a type, it is added
2216: to the slot whose index is the hash code mod the table size.
2217: Note that the hash table is used for several kinds of types
2218: (function types, array types and array index range types, for now).
2219: While all these live in the same table, they are completely independent,
2220: and the hash code is computed differently for each of these. */
2221:
2222: #define TYPE_HASH_SIZE 59
2223: struct type_hash *type_hash_table[TYPE_HASH_SIZE];
2224:
2225: /* Here is how primitive or already-canonicalized types' hash
2226: codes are made. */
2227: #define TYPE_HASH(TYPE) ((int) (TYPE) & 0777777)
2228:
2229: /* Compute a hash code for a list of types (chain of TREE_LIST nodes
2230: with types in the TREE_VALUE slots), by adding the hash codes
2231: of the individual types. */
2232:
2233: int
2234: type_hash_list (list)
2235: tree list;
2236: {
2237: register int hashcode;
2238: register tree tail;
2239: for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
2240: hashcode += TYPE_HASH (TREE_VALUE (tail));
2241: return hashcode;
2242: }
2243:
2244: /* Look in the type hash table for a type isomorphic to TYPE.
2245: If one is found, return it. Otherwise return 0. */
2246:
2247: tree
2248: type_hash_lookup (hashcode, type)
2249: int hashcode;
2250: tree type;
2251: {
2252: register struct type_hash *h;
2253: for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
2254: if (h->hashcode == hashcode
2255: && TREE_CODE (h->type) == TREE_CODE (type)
2256: && TREE_TYPE (h->type) == TREE_TYPE (type)
2257: && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
2258: || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
2259: TYPE_MAX_VALUE (type)))
2260: && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
2261: || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
2262: TYPE_MIN_VALUE (type)))
2263: && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
2264: || (TYPE_DOMAIN (h->type)
2265: && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
2266: && TYPE_DOMAIN (type)
2267: && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
2268: && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
2269: return h->type;
2270: return 0;
2271: }
2272:
2273: /* Add an entry to the type-hash-table
2274: for a type TYPE whose hash code is HASHCODE. */
2275:
2276: void
2277: type_hash_add (hashcode, type)
2278: int hashcode;
2279: tree type;
2280: {
2281: register struct type_hash *h;
2282:
2283: h = (struct type_hash *) oballoc (sizeof (struct type_hash));
2284: h->hashcode = hashcode;
2285: h->type = type;
2286: h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
2287: type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
2288: }
2289:
2290: /* Given TYPE, and HASHCODE its hash code, return the canonical
2291: object for an identical type if one already exists.
2292: Otherwise, return TYPE, and record it as the canonical object
2293: if it is a permanent object.
2294:
2295: To use this function, first create a type of the sort you want.
2296: Then compute its hash code from the fields of the type that
2297: make it different from other similar types.
2298: Then call this function and use the value.
2299: This function frees the type you pass in if it is a duplicate. */
2300:
2301: /* Set to 1 to debug without canonicalization. Never set by program. */
2302: int debug_no_type_hash = 0;
2303:
2304: tree
2305: type_hash_canon (hashcode, type)
2306: int hashcode;
2307: tree type;
2308: {
2309: tree t1;
2310:
2311: if (debug_no_type_hash)
2312: return type;
2313:
2314: t1 = type_hash_lookup (hashcode, type);
2315: if (t1 != 0)
2316: {
2317: struct obstack *o
2318: = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2319: obstack_free (o, type);
2320: #ifdef GATHER_STATISTICS
2321: tree_node_counts[(int)t_kind]--;
2322: tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
2323: #endif
2324: return t1;
2325: }
2326:
2327: /* If this is a new type, record it for later reuse. */
2328: if (current_obstack == &permanent_obstack)
2329: type_hash_add (hashcode, type);
2330:
2331: return type;
2332: }
2333:
2334: /* Given two lists of types
2335: (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
2336: return 1 if the lists contain the same types in the same order.
2337: Also, the TREE_PURPOSEs must match. */
2338:
2339: int
2340: type_list_equal (l1, l2)
2341: tree l1, l2;
2342: {
2343: register tree t1, t2;
2344: for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
2345: {
2346: if (TREE_VALUE (t1) != TREE_VALUE (t2))
2347: return 0;
2348: if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2))
2349: {
2350: int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
2351: if (cmp < 0)
2352: abort ();
2353: if (cmp == 0)
2354: return 0;
2355: }
2356: }
2357:
2358: return t1 == t2;
2359: }
2360:
2361: /* Nonzero if integer constants T1 and T2
2362: represent the same constant value. */
2363:
2364: int
2365: tree_int_cst_equal (t1, t2)
2366: tree t1, t2;
2367: {
2368: if (t1 == t2)
2369: return 1;
2370: if (t1 == 0 || t2 == 0)
2371: return 0;
2372: if (TREE_CODE (t1) == INTEGER_CST
2373: && TREE_CODE (t2) == INTEGER_CST
2374: && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2375: && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
2376: return 1;
2377: return 0;
2378: }
2379:
2380: /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
2381: The precise way of comparison depends on their data type. */
2382:
2383: int
2384: tree_int_cst_lt (t1, t2)
2385: tree t1, t2;
2386: {
2387: if (t1 == t2)
2388: return 0;
2389:
2390: if (!TREE_UNSIGNED (TREE_TYPE (t1)))
2391: return INT_CST_LT (t1, t2);
2392: return INT_CST_LT_UNSIGNED (t1, t2);
2393: }
2394:
2395: /* Compare two constructor-element-type constants. */
2396: int
2397: simple_cst_list_equal (l1, l2)
2398: tree l1, l2;
2399: {
2400: while (l1 != NULL_TREE && l2 != NULL_TREE)
2401: {
2402: int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2));
2403: if (cmp < 0)
2404: abort ();
2405: if (cmp == 0)
2406: return 0;
2407: l1 = TREE_CHAIN (l1);
2408: l2 = TREE_CHAIN (l2);
2409: }
2410: return (l1 == l2);
2411: }
2412:
2413: /* Return truthvalue of whether T1 is the same tree structure as T2.
2414: Return 1 if they are the same.
2415: Return 0 if they are understandably different.
2416: Return -1 if either contains tree structure not understood by
2417: this function. */
2418:
2419: int
2420: simple_cst_equal (t1, t2)
2421: tree t1, t2;
2422: {
2423: register enum tree_code code1, code2;
2424: int cmp;
2425:
2426: if (t1 == t2)
2427: return 1;
2428: if (t1 == 0 || t2 == 0)
2429: return 0;
2430:
2431: code1 = TREE_CODE (t1);
2432: code2 = TREE_CODE (t2);
2433:
2434: if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
2435: if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
2436: return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2437: else
2438: return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
2439: else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
2440: || code2 == NON_LVALUE_EXPR)
2441: return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
2442:
2443: if (code1 != code2)
2444: return 0;
2445:
2446: switch (code1)
2447: {
2448: case INTEGER_CST:
2449: return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2450: && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
2451:
2452: case REAL_CST:
2453: return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2454:
2455: case STRING_CST:
2456: return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2457: && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2458: TREE_STRING_LENGTH (t1));
2459:
2460: case CONSTRUCTOR:
2461: abort ();
2462:
2463: case SAVE_EXPR:
2464: return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2465:
2466: case CALL_EXPR:
2467: cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2468: if (cmp <= 0)
2469: return cmp;
2470: return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2471:
2472: case TARGET_EXPR:
2473: /* Special case: if either target is an unallocated VAR_DECL,
2474: it means that it's going to be unified with whatever the
2475: TARGET_EXPR is really supposed to initialize, so treat it
2476: as being equivalent to anything. */
2477: if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
2478: && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
2479: && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
2480: || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
2481: && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
2482: && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
2483: cmp = 1;
2484: else
2485: cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2486: if (cmp <= 0)
2487: return cmp;
2488: return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2489:
2490: case WITH_CLEANUP_EXPR:
2491: cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2492: if (cmp <= 0)
2493: return cmp;
2494: return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
2495:
2496: case COMPONENT_REF:
2497: if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
2498: return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2499: return 0;
2500:
2501: case BIT_FIELD_REF:
2502: return (simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2503: && simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1))
2504: && simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t2, 2)));
2505:
2506: case VAR_DECL:
2507: case PARM_DECL:
2508: case CONST_DECL:
2509: case FUNCTION_DECL:
2510: return 0;
2511:
2512: case PLUS_EXPR:
2513: case MINUS_EXPR:
2514: case MULT_EXPR:
2515: case TRUNC_DIV_EXPR:
2516: case TRUNC_MOD_EXPR:
2517: case LSHIFT_EXPR:
2518: case RSHIFT_EXPR:
2519: cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2520: if (cmp <= 0)
2521: return cmp;
2522: return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2523:
2524: case NEGATE_EXPR:
2525: case ADDR_EXPR:
2526: case REFERENCE_EXPR:
2527: case INDIRECT_REF:
2528: return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2529:
2530: default:
2531: #if 0
2532: return lang_simple_cst_equal (t1, t2);
2533: #else
2534: return -1;
2535: #endif
2536: }
2537: }
2538:
2539: /* Constructors for pointer, array and function types.
2540: (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
2541: constructed by language-dependent code, not here.) */
2542:
2543: /* Construct, lay out and return the type of pointers to TO_TYPE.
2544: If such a type has already been constructed, reuse it. */
2545:
2546: tree
2547: build_pointer_type (to_type)
2548: tree to_type;
2549: {
2550: register tree t = TYPE_POINTER_TO (to_type);
2551: register struct obstack *ambient_obstack = current_obstack;
2552: register struct obstack *ambient_saveable_obstack = saveable_obstack;
2553:
2554: /* First, if we already have a type for pointers to TO_TYPE, use it. */
2555:
2556: if (t)
2557: return t;
2558:
2559: /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2560: if (TREE_PERMANENT (to_type))
2561: {
2562: current_obstack = &permanent_obstack;
2563: saveable_obstack = &permanent_obstack;
2564: }
2565:
2566: t = make_node (POINTER_TYPE);
2567: TREE_TYPE (t) = to_type;
2568:
2569: /* Record this type as the pointer to TO_TYPE. */
2570: TYPE_POINTER_TO (to_type) = t;
2571:
2572: /* Lay out the type. This function has many callers that are concerned
2573: with expression-construction, and this simplifies them all.
2574: Also, it guarantees the TYPE_SIZE is permanent if the type is. */
2575: layout_type (t);
2576:
2577: current_obstack = ambient_obstack;
2578: saveable_obstack = ambient_saveable_obstack;
2579: return t;
2580: }
2581:
2582: /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
2583: MAXVAL should be the maximum value in the domain
2584: (one less than the length of the array). */
2585:
2586: tree
2587: build_index_type (maxval)
2588: tree maxval;
2589: {
2590: register tree itype = make_node (INTEGER_TYPE);
2591: TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2592: TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
2593: TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
2594: TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
2595: TYPE_MODE (itype) = TYPE_MODE (sizetype);
2596: TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2597: TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2598: if (TREE_CODE (maxval) == INTEGER_CST)
2599: {
2600: int maxint = TREE_INT_CST_LOW (maxval);
2601: return type_hash_canon (maxint > 0 ? maxint : - maxint, itype);
2602: }
2603: else
2604: return itype;
2605: }
2606:
2607: /* Just like build_index_type, but takes lowval and highval instead
2608: of just highval (maxval). */
2609:
2610: tree
2611: build_index_2_type (lowval,highval)
2612: tree lowval, highval;
2613: {
2614: register tree itype = make_node (INTEGER_TYPE);
2615: TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2616: TYPE_MIN_VALUE (itype) = convert (sizetype, lowval);
2617: TYPE_MAX_VALUE (itype) = convert (sizetype, highval);
2618: TYPE_MODE (itype) = TYPE_MODE (sizetype);
2619: TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2620: TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2621: if ((TREE_CODE (lowval) == INTEGER_CST)
2622: && (TREE_CODE (highval) == INTEGER_CST))
2623: {
2624: int highint = TREE_INT_CST_LOW (highval);
2625: int lowint = TREE_INT_CST_LOW (lowval);
2626: int maxint = highint - lowint;
2627: return type_hash_canon (maxint > 0 ? maxint : - maxint, itype);
2628: }
2629: else
2630: return itype;
2631: }
2632:
2633: /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
2634: Needed because when index types are not hashed, equal index types
2635: built at different times appear distinct, even though structurally,
2636: they are not. */
2637:
2638: int
2639: index_type_equal (itype1, itype2)
2640: tree itype1, itype2;
2641: {
2642: if (TREE_CODE (itype1) != TREE_CODE (itype2))
2643: return 0;
2644: if (TREE_CODE (itype1) == INTEGER_TYPE)
2645: {
2646: if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
2647: || TYPE_MODE (itype1) != TYPE_MODE (itype2)
2648: || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2))
2649: || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
2650: return 0;
2651: if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2))
2652: && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2)))
2653: return 1;
2654: }
2655: return 0;
2656: }
2657:
2658: /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
2659: and number of elements specified by the range of values of INDEX_TYPE.
2660: If such a type has already been constructed, reuse it. */
2661:
2662: tree
2663: build_array_type (elt_type, index_type)
2664: tree elt_type, index_type;
2665: {
2666: register tree t;
2667: int hashcode;
2668:
2669: if (TREE_CODE (elt_type) == FUNCTION_TYPE)
2670: {
2671: error ("arrays of functions are not meaningful");
2672: elt_type = integer_type_node;
2673: }
2674:
2675: /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
2676: build_pointer_type (elt_type);
2677:
2678: /* Allocate the array after the pointer type,
2679: in case we free it in type_hash_canon. */
2680: t = make_node (ARRAY_TYPE);
2681: TREE_TYPE (t) = elt_type;
2682: TYPE_DOMAIN (t) = index_type;
2683:
2684: if (index_type == 0)
2685: return t;
2686:
2687: hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
2688: t = type_hash_canon (hashcode, t);
2689:
2690: if (TYPE_SIZE (t) == 0)
2691: layout_type (t);
2692: return t;
2693: }
2694:
2695: /* Construct, lay out and return
2696: the type of functions returning type VALUE_TYPE
2697: given arguments of types ARG_TYPES.
2698: ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
2699: are data type nodes for the arguments of the function.
2700: If such a type has already been constructed, reuse it. */
2701:
2702: tree
2703: build_function_type (value_type, arg_types)
2704: tree value_type, arg_types;
2705: {
2706: register tree t;
2707: int hashcode;
2708:
2709: if (TREE_CODE (value_type) == FUNCTION_TYPE
2710: || TREE_CODE (value_type) == ARRAY_TYPE)
2711: {
2712: error ("function return type cannot be function or array");
2713: value_type = integer_type_node;
2714: }
2715:
2716: /* Make a node of the sort we want. */
2717: t = make_node (FUNCTION_TYPE);
2718: TREE_TYPE (t) = value_type;
2719: TYPE_ARG_TYPES (t) = arg_types;
2720:
2721: /* If we already have such a type, use the old one and free this one. */
2722: hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
2723: t = type_hash_canon (hashcode, t);
2724:
2725: if (TYPE_SIZE (t) == 0)
2726: layout_type (t);
2727: return t;
2728: }
2729:
2730: /* Build the node for the type of references-to-TO_TYPE. */
2731:
2732: tree
2733: build_reference_type (to_type)
2734: tree to_type;
2735: {
2736: register tree t = TYPE_REFERENCE_TO (to_type);
2737: register struct obstack *ambient_obstack = current_obstack;
2738: register struct obstack *ambient_saveable_obstack = saveable_obstack;
2739:
2740: /* First, if we already have a type for pointers to TO_TYPE, use it. */
2741:
2742: if (t)
2743: return t;
2744:
2745: /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2746: if (TREE_PERMANENT (to_type))
2747: {
2748: current_obstack = &permanent_obstack;
2749: saveable_obstack = &permanent_obstack;
2750: }
2751:
2752: t = make_node (REFERENCE_TYPE);
2753: TREE_TYPE (t) = to_type;
2754:
2755: /* Record this type as the pointer to TO_TYPE. */
2756: TYPE_REFERENCE_TO (to_type) = t;
2757:
2758: layout_type (t);
2759:
2760: current_obstack = ambient_obstack;
2761: saveable_obstack = ambient_saveable_obstack;
2762: return t;
2763: }
2764:
2765: /* Construct, lay out and return the type of methods belonging to class
2766: BASETYPE and whose arguments and values are described by TYPE.
2767: If that type exists already, reuse it.
2768: TYPE must be a FUNCTION_TYPE node. */
2769:
2770: tree
2771: build_method_type (basetype, type)
2772: tree basetype, type;
2773: {
2774: register tree t;
2775: int hashcode;
2776:
2777: /* Make a node of the sort we want. */
2778: t = make_node (METHOD_TYPE);
2779:
2780: if (TREE_CODE (type) != FUNCTION_TYPE)
2781: abort ();
2782:
2783: TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2784: TREE_TYPE (t) = TREE_TYPE (type);
2785:
2786: /* The actual arglist for this function includes a "hidden" argument
2787: which is "this". Put it into the list of argument types. */
2788:
2789: TYPE_ARG_TYPES (t)
2790: = tree_cons (NULL, build_pointer_type (basetype), TYPE_ARG_TYPES (type));
2791:
2792: /* If we already have such a type, use the old one and free this one. */
2793: hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2794: t = type_hash_canon (hashcode, t);
2795:
2796: if (TYPE_SIZE (t) == 0)
2797: layout_type (t);
2798:
2799: return t;
2800: }
2801:
2802: /* Construct, lay out and return the type of methods belonging to class
2803: BASETYPE and whose arguments and values are described by TYPE.
2804: If that type exists already, reuse it.
2805: TYPE must be a FUNCTION_TYPE node. */
2806:
2807: tree
2808: build_offset_type (basetype, type)
2809: tree basetype, type;
2810: {
2811: register tree t;
2812: int hashcode;
2813:
2814: /* Make a node of the sort we want. */
2815: t = make_node (OFFSET_TYPE);
2816:
2817: TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2818: TREE_TYPE (t) = type;
2819:
2820: /* If we already have such a type, use the old one and free this one. */
2821: hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2822: t = type_hash_canon (hashcode, t);
2823:
2824: if (TYPE_SIZE (t) == 0)
2825: layout_type (t);
2826:
2827: return t;
2828: }
2829:
2830: /* Create a complex type whose components are COMPONENT_TYPE. */
2831:
2832: tree
2833: build_complex_type (component_type)
2834: tree component_type;
2835: {
2836: register tree t;
2837: int hashcode;
2838:
2839: /* Make a node of the sort we want. */
2840: t = make_node (COMPLEX_TYPE);
2841:
2842: TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
2843: TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
2844: TYPE_READONLY (t) = TYPE_READONLY (component_type);
2845:
2846: /* If we already have such a type, use the old one and free this one. */
2847: hashcode = TYPE_HASH (component_type);
2848: t = type_hash_canon (hashcode, t);
2849:
2850: if (TYPE_SIZE (t) == 0)
2851: layout_type (t);
2852:
2853: return t;
2854: }
2855:
2856: /* Return OP, stripped of any conversions to wider types as much as is safe.
2857: Converting the value back to OP's type makes a value equivalent to OP.
2858:
2859: If FOR_TYPE is nonzero, we return a value which, if converted to
2860: type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
2861:
2862: If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
2863: narrowest type that can hold the value, even if they don't exactly fit.
2864: Otherwise, bit-field references are changed to a narrower type
2865: only if they can be fetched directly from memory in that type.
2866:
2867: OP must have integer, real or enumeral type. Pointers are not allowed!
2868:
2869: There are some cases where the obvious value we could return
2870: would regenerate to OP if converted to OP's type,
2871: but would not extend like OP to wider types.
2872: If FOR_TYPE indicates such extension is contemplated, we eschew such values.
2873: For example, if OP is (unsigned short)(signed char)-1,
2874: we avoid returning (signed char)-1 if FOR_TYPE is int,
2875: even though extending that to an unsigned short would regenerate OP,
2876: since the result of extending (signed char)-1 to (int)
2877: is different from (int) OP. */
2878:
2879: tree
2880: get_unwidened (op, for_type)
2881: register tree op;
2882: tree for_type;
2883: {
2884: /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
2885: /* TYPE_PRECISION is safe in place of type_precision since
2886: pointer types are not allowed. */
2887: register tree type = TREE_TYPE (op);
2888: register unsigned final_prec
2889: = TYPE_PRECISION (for_type != 0 ? for_type : type);
2890: register int uns
2891: = (for_type != 0 && for_type != type
2892: && final_prec > TYPE_PRECISION (type)
2893: && TREE_UNSIGNED (type));
2894: register tree win = op;
2895:
2896: while (TREE_CODE (op) == NOP_EXPR)
2897: {
2898: register int bitschange
2899: = TYPE_PRECISION (TREE_TYPE (op))
2900: - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
2901:
2902: /* Truncations are many-one so cannot be removed.
2903: Unless we are later going to truncate down even farther. */
2904: if (bitschange < 0
2905: && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
2906: break;
2907:
2908: /* See what's inside this conversion. If we decide to strip it,
2909: we will set WIN. */
2910: op = TREE_OPERAND (op, 0);
2911:
2912: /* If we have not stripped any zero-extensions (uns is 0),
2913: we can strip any kind of extension.
2914: If we have previously stripped a zero-extension,
2915: only zero-extensions can safely be stripped.
2916: Any extension can be stripped if the bits it would produce
2917: are all going to be discarded later by truncating to FOR_TYPE. */
2918:
2919: if (bitschange > 0)
2920: {
2921: if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
2922: win = op;
2923: /* TREE_UNSIGNED says whether this is a zero-extension.
2924: Let's avoid computing it if it does not affect WIN
2925: and if UNS will not be needed again. */
2926: if ((uns || TREE_CODE (op) == NOP_EXPR)
2927: && TREE_UNSIGNED (TREE_TYPE (op)))
2928: {
2929: uns = 1;
2930: win = op;
2931: }
2932: }
2933: }
2934:
2935: if (TREE_CODE (op) == COMPONENT_REF
2936: /* Since type_for_size always gives an integer type. */
2937: && TREE_CODE (type) != REAL_TYPE)
2938: {
2939: unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
2940: type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
2941:
2942: /* We can get this structure field in the narrowest type it fits in.
2943: If FOR_TYPE is 0, do this only for a field that matches the
2944: narrower type exactly and is aligned for it
2945: The resulting extension to its nominal type (a fullword type)
2946: must fit the same conditions as for other extensions. */
2947:
2948: if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
2949: && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
2950: && (! uns || final_prec <= innerprec
2951: || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
2952: && type != 0)
2953: {
2954: win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
2955: TREE_OPERAND (op, 1));
2956: TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
2957: TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
2958: TREE_RAISES (win) = TREE_RAISES (op);
2959: }
2960: }
2961: return win;
2962: }
2963:
2964: /* Return OP or a simpler expression for a narrower value
2965: which can be sign-extended or zero-extended to give back OP.
2966: Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
2967: or 0 if the value should be sign-extended. */
2968:
2969: tree
2970: get_narrower (op, unsignedp_ptr)
2971: register tree op;
2972: int *unsignedp_ptr;
2973: {
2974: register int uns = 0;
2975: int first = 1;
2976: register tree win = op;
2977:
2978: while (TREE_CODE (op) == NOP_EXPR)
2979: {
2980: register int bitschange
2981: = TYPE_PRECISION (TREE_TYPE (op))
2982: - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
2983:
2984: /* Truncations are many-one so cannot be removed. */
2985: if (bitschange < 0)
2986: break;
2987:
2988: /* See what's inside this conversion. If we decide to strip it,
2989: we will set WIN. */
2990: op = TREE_OPERAND (op, 0);
2991:
2992: if (bitschange > 0)
2993: {
2994: /* An extension: the outermost one can be stripped,
2995: but remember whether it is zero or sign extension. */
2996: if (first)
2997: uns = TREE_UNSIGNED (TREE_TYPE (op));
2998: /* Otherwise, if a sign extension has been stripped,
2999: only sign extensions can now be stripped;
3000: if a zero extension has been stripped, only zero-extensions. */
3001: else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
3002: break;
3003: first = 0;
3004: }
3005: /* A change in nominal type can always be stripped. */
3006:
3007: win = op;
3008: }
3009:
3010: if (TREE_CODE (op) == COMPONENT_REF
3011: /* Since type_for_size always gives an integer type. */
3012: && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
3013: {
3014: unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3015: tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
3016:
3017: /* We can get this structure field in a narrower type that fits it,
3018: but the resulting extension to its nominal type (a fullword type)
3019: must satisfy the same conditions as for other extensions.
3020:
3021: Do this only for fields that are aligned (not bit-fields),
3022: because when bit-field insns will be used there is no
3023: advantage in doing this. */
3024:
3025: if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3026: && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
3027: && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3028: && type != 0)
3029: {
3030: if (first)
3031: uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
3032: win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3033: TREE_OPERAND (op, 1));
3034: TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3035: TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3036: TREE_RAISES (win) = TREE_RAISES (op);
3037: }
3038: }
3039: *unsignedp_ptr = uns;
3040: return win;
3041: }
3042:
3043: /* Return the precision of a type, for arithmetic purposes.
3044: Supports all types on which arithmetic is possible
3045: (including pointer types).
3046: It's not clear yet what will be right for complex types. */
3047:
3048: int
3049: type_precision (type)
3050: register tree type;
3051: {
3052: return ((TREE_CODE (type) == INTEGER_TYPE
3053: || TREE_CODE (type) == ENUMERAL_TYPE
3054: || TREE_CODE (type) == REAL_TYPE)
3055: ? TYPE_PRECISION (type) : POINTER_SIZE);
3056: }
3057:
3058: /* Nonzero if integer constant C has a value that is permissible
3059: for type TYPE (an INTEGER_TYPE). */
3060:
3061: int
3062: int_fits_type_p (c, type)
3063: tree c, type;
3064: {
3065: if (TREE_UNSIGNED (type))
3066: return (!INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c)
3067: && !INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)));
3068: else
3069: return (!INT_CST_LT (TYPE_MAX_VALUE (type), c)
3070: && !INT_CST_LT (c, TYPE_MIN_VALUE (type)));
3071: }
3072:
3073: /* Return the innermost context enclosing FNDECL that is
3074: a FUNCTION_DECL, or zero if none. */
3075:
3076: tree
3077: decl_function_context (fndecl)
3078: tree fndecl;
3079: {
3080: tree context;
3081:
3082: if (TREE_CODE (fndecl) == ERROR_MARK)
3083: return 0;
3084:
3085: if (TREE_CODE (fndecl) == SAVE_EXPR)
3086: context = SAVE_EXPR_CONTEXT (fndecl);
3087: else
3088: context = DECL_CONTEXT (fndecl);
3089:
3090: while (context && TREE_CODE (context) != FUNCTION_DECL)
3091: {
3092: if (TREE_CODE (context) == RECORD_TYPE
3093: || TREE_CODE (context) == UNION_TYPE)
3094: context = TYPE_CONTEXT (context);
3095: else if (TREE_CODE (context) == TYPE_DECL)
3096: context = DECL_CONTEXT (context);
3097: else if (TREE_CODE (context) == BLOCK)
3098: context = BLOCK_SUPERCONTEXT (context);
3099: else
3100: /* Unhandled CONTEXT !? */
3101: abort ();
3102: }
3103:
3104: return context;
3105: }
3106:
3107: /* Return the innermost context enclosing FNDECL that is
3108: a RECORD_TYPE or UNION_TYPE, or zero if none.
3109: TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
3110:
3111: tree
3112: decl_type_context (fndecl)
3113: tree fndecl;
3114: {
3115: tree context = DECL_CONTEXT (fndecl);
3116:
3117: while (context)
3118: {
3119: if (TREE_CODE (context) == RECORD_TYPE
3120: || TREE_CODE (context) == UNION_TYPE)
3121: return context;
3122: if (TREE_CODE (context) == TYPE_DECL
3123: || TREE_CODE (context) == FUNCTION_DECL)
3124: context = DECL_CONTEXT (context);
3125: else if (TREE_CODE (context) == BLOCK)
3126: context = BLOCK_SUPERCONTEXT (context);
3127: else
3128: /* Unhandled CONTEXT!? */
3129: abort ();
3130: }
3131: return NULL_TREE;
3132: }
3133:
3134: void
3135: print_obstack_statistics (str, o)
3136: char *str;
3137: struct obstack *o;
3138: {
3139: struct _obstack_chunk *chunk = o->chunk;
3140: int n_chunks = 0;
3141: int n_alloc = 0;
3142:
3143: while (chunk)
3144: {
3145: n_chunks += 1;
3146: n_alloc += chunk->limit - &chunk->contents[0];
3147: chunk = chunk->prev;
3148: }
3149: fprintf (stderr, "obstack %s: %d bytes, %d chunks\n",
3150: str, n_alloc, n_chunks);
3151: }
3152: void
3153: dump_tree_statistics ()
3154: {
3155: int i;
3156: int total_nodes, total_bytes;
3157:
3158: fprintf (stderr, "\n??? tree nodes created\n\n");
3159: #ifdef GATHER_STATISTICS
3160: fprintf (stderr, "Kind Nodes Bytes\n");
3161: fprintf (stderr, "-------------------------------------\n");
3162: total_nodes = total_bytes = 0;
3163: for (i = 0; i < (int) all_kinds; i++)
3164: {
3165: fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
3166: tree_node_counts[i], tree_node_sizes[i]);
3167: total_nodes += tree_node_counts[i];
3168: total_bytes += tree_node_sizes[i];
3169: }
3170: fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
3171: fprintf (stderr, "-------------------------------------\n");
3172: fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
3173: fprintf (stderr, "-------------------------------------\n");
3174: #else
3175: fprintf (stderr, "(No per-node statistics)\n");
3176: #endif
3177: print_lang_statistics ();
3178: }
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