init.c revision 1.90 1 /* $NetBSD: init.c,v 1.90 2021/03/17 15:37:42 rillig Exp $ */
2
3 /*
4 * Copyright (c) 1994, 1995 Jochen Pohl
5 * All Rights Reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Jochen Pohl for
18 * The NetBSD Project.
19 * 4. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #if HAVE_NBTOOL_CONFIG_H
35 #include "nbtool_config.h"
36 #endif
37
38 #include <sys/cdefs.h>
39 #if defined(__RCSID) && !defined(lint)
40 __RCSID("$NetBSD: init.c,v 1.90 2021/03/17 15:37:42 rillig Exp $");
41 #endif
42
43 #include <stdlib.h>
44 #include <string.h>
45
46 #include "lint1.h"
47
48
49 /*
50 * Type of stack which is used for initialization of aggregate types.
51 *
52 * XXX: Since C99, a stack is an inappropriate data structure for modelling
53 * an initialization, since the designators don't have to be listed in a
54 * particular order and can designate parts of sub-objects. The member names
55 * of non-leaf structs may thus appear repeatedly, as demonstrated in
56 * d_init_pop_member.c.
57 *
58 * XXX: During initialization, there may be members of the top-level struct
59 * that are partially initialized. The simple i_remaining cannot model this
60 * appropriately.
61 *
62 * See C99 6.7.8, which spans 6 pages full of tricky details and carefully
63 * selected examples.
64 */
65 typedef struct initstack_element {
66
67 /* XXX: Why is i_type often null? */
68 type_t *i_type; /* type of initialization */
69 type_t *i_subt; /* type of next level */
70
71 /*
72 * This level of the initializer requires a '}' to be completed.
73 *
74 * Multidimensional arrays do not need a closing brace to complete
75 * an inner array; for example, { 1, 2, 3, 4 } is a valid initializer
76 * for int arr[2][2].
77 *
78 * TODO: Do structs containing structs need a closing brace?
79 * TODO: Do arrays of structs need a closing brace after each struct?
80 */
81 bool i_brace: 1;
82
83 bool i_array_of_unknown_size: 1;
84 bool i_seen_named_member: 1;
85
86 /*
87 * For structs, the next member to be initialized by an initializer
88 * without an optional designator.
89 */
90 sym_t *i_current_object;
91
92 /*
93 * The number of remaining elements.
94 *
95 * XXX: for scalars?
96 * XXX: for structs?
97 * XXX: for unions?
98 * XXX: for arrays?
99 */
100 int i_remaining;
101
102 /*
103 * The initialization state of the enclosing data structure
104 * (struct, union, array).
105 */
106 struct initstack_element *i_enclosing;
107 } initstack_element;
108
109 /*
110 * The names for a nested C99 initialization designator, in a circular list.
111 *
112 * Example:
113 * struct stat st = {
114 * .st_size = 123,
115 * .st_mtim.tv_sec = 45,
116 * .st_mtim.tv_nsec
117 * };
118 *
119 * During initialization, this list first contains ["st_size"], then
120 * ["st_mtim", "tv_sec"], then ["st_mtim", "tv_nsec"].
121 */
122 typedef struct namlist {
123 const char *n_name;
124 struct namlist *n_prev;
125 struct namlist *n_next;
126 } namlist_t;
127
128
129 /*
130 * initerr is set as soon as a fatal error occurred in an initialization.
131 * The effect is that the rest of the initialization is ignored (parsed
132 * by yacc, expression trees built, but no initialization takes place).
133 */
134 bool initerr;
135
136 /* Pointer to the symbol which is to be initialized. */
137 sym_t *initsym;
138
139 /* Points to the top element of the initialization stack. */
140 initstack_element *initstk;
141
142 /* Points to a c9x named member; */
143 namlist_t *namedmem = NULL;
144
145
146 static bool init_array_using_string(tnode_t *);
147
148 #ifndef DEBUG
149
150 #define debug_printf(fmt, ...) do { } while (false)
151 #define debug_indent() do { } while (false)
152 #define debug_enter(a) do { } while (false)
153 #define debug_step(fmt, ...) do { } while (false)
154 #define debug_leave(a) do { } while (false)
155 #define debug_named_member() do { } while (false)
156 #define debug_initstack_element(elem) do { } while (false)
157 #define debug_initstack() do { } while (false)
158
159 #else
160
161 static int debug_ind = 0;
162
163 static void __printflike(1, 2)
164 debug_printf(const char *fmt, ...)
165 {
166 va_list va;
167
168 va_start(va, fmt);
169 vfprintf(stdout, fmt, va);
170 va_end(va);
171 }
172
173 static void
174 debug_indent(void)
175 {
176 debug_printf("%*s", 2 * debug_ind, "");
177 }
178
179 static void
180 debug_enter(const char *func)
181 {
182 printf("%*s+ %s\n", 2 * debug_ind++, "", func);
183 }
184
185 static void __printflike(1, 2)
186 debug_step(const char *fmt, ...)
187 {
188 va_list va;
189
190 printf("%*s", 2 * debug_ind, "");
191 va_start(va, fmt);
192 vfprintf(stdout, fmt, va);
193 va_end(va);
194 printf("\n");
195 }
196
197 static void
198 debug_leave(const char *func)
199 {
200 printf("%*s- %s\n", 2 * --debug_ind, "", func);
201 }
202
203 static void
204 debug_named_member(void)
205 {
206 namlist_t *name;
207
208 if (namedmem == NULL)
209 return;
210 name = namedmem;
211 debug_indent();
212 debug_printf("named member:");
213 do {
214 debug_printf(" %s", name->n_name);
215 name = name->n_next;
216 } while (name != namedmem);
217 debug_printf("\n");
218 }
219
220 static void
221 debug_initstack_element(const initstack_element *elem)
222 {
223 if (elem->i_type != NULL)
224 debug_step(" i_type = %s", type_name(elem->i_type));
225 if (elem->i_subt != NULL)
226 debug_step(" i_subt = %s", type_name(elem->i_subt));
227
228 if (elem->i_brace)
229 debug_step(" i_brace");
230 if (elem->i_array_of_unknown_size)
231 debug_step(" i_array_of_unknown_size");
232 if (elem->i_seen_named_member)
233 debug_step(" i_seen_named_member");
234
235 const type_t *eff_type = elem->i_type != NULL
236 ? elem->i_type : elem->i_subt;
237 if (eff_type->t_tspec == STRUCT && elem->i_current_object != NULL)
238 debug_step(" i_current_object = %s",
239 elem->i_current_object->s_name);
240
241 debug_step(" i_remaining = %d", elem->i_remaining);
242 }
243
244 static void
245 debug_initstack(void)
246 {
247 if (initstk == NULL) {
248 debug_step("initstk is empty");
249 return;
250 }
251
252 size_t i = 0;
253 for (const initstack_element *elem = initstk;
254 elem != NULL; elem = elem->i_enclosing) {
255 debug_step("initstk[%zu]:", i);
256 debug_initstack_element(elem);
257 i++;
258 }
259 }
260
261 #define debug_enter() debug_enter(__func__)
262 #define debug_leave() debug_leave(__func__)
263
264 #endif
265
266 void
267 push_member(sbuf_t *sb)
268 {
269 namlist_t *nam = xcalloc(1, sizeof (namlist_t));
270 nam->n_name = sb->sb_name;
271
272 debug_step("%s: '%s' %p", __func__, nam->n_name, nam);
273
274 if (namedmem == NULL) {
275 /*
276 * XXX: Why is this a circular list?
277 * XXX: Why is this a doubly-linked list?
278 * A simple stack should suffice.
279 */
280 nam->n_prev = nam->n_next = nam;
281 namedmem = nam;
282 } else {
283 namedmem->n_prev->n_next = nam;
284 nam->n_prev = namedmem->n_prev;
285 nam->n_next = namedmem;
286 namedmem->n_prev = nam;
287 }
288 }
289
290 static void
291 pop_member(void)
292 {
293 debug_step("%s: %s %p", __func__, namedmem->n_name, namedmem);
294 if (namedmem->n_next == namedmem) {
295 free(namedmem);
296 namedmem = NULL;
297 } else {
298 namlist_t *nam = namedmem;
299 namedmem = namedmem->n_next;
300 nam->n_prev->n_next = nam->n_next;
301 nam->n_next->n_prev = nam->n_prev;
302 free(nam);
303 }
304 }
305
306 /*
307 * Initialize the initialization stack by putting an entry for the object
308 * which is to be initialized on it.
309 */
310 void
311 initstack_init(void)
312 {
313 initstack_element *istk;
314
315 if (initerr)
316 return;
317
318 /* free memory used in last initialization */
319 while ((istk = initstk) != NULL) {
320 initstk = istk->i_enclosing;
321 free(istk);
322 }
323
324 debug_enter();
325
326 /*
327 * If the type which is to be initialized is an incomplete array,
328 * it must be duplicated.
329 */
330 if (initsym->s_type->t_tspec == ARRAY && is_incomplete(initsym->s_type))
331 initsym->s_type = duptyp(initsym->s_type);
332
333 istk = initstk = xcalloc(1, sizeof (initstack_element));
334 istk->i_subt = initsym->s_type;
335 istk->i_remaining = 1;
336
337 debug_initstack();
338 debug_leave();
339 }
340
341 static void
342 initstack_pop_item(void)
343 {
344 initstack_element *istk;
345 sym_t *m;
346
347 debug_enter();
348
349 istk = initstk;
350 debug_step("popping:");
351 debug_initstack_element(istk);
352
353 initstk = istk->i_enclosing;
354 free(istk);
355 istk = initstk;
356 lint_assert(istk != NULL);
357
358 istk->i_remaining--;
359 lint_assert(istk->i_remaining >= 0);
360
361 debug_step("new top element with updated remaining:");
362 debug_initstack_element(istk);
363
364 if (namedmem != NULL) {
365 debug_step("initializing named member '%s'", namedmem->n_name);
366
367 /* XXX: undefined behavior if this is reached with an array? */
368 for (m = istk->i_type->t_str->sou_first_member;
369 m != NULL; m = m->s_next) {
370
371 if (m->s_bitfield && m->s_name == unnamed)
372 continue;
373
374 if (strcmp(m->s_name, namedmem->n_name) == 0) {
375 debug_step("found matching member");
376 istk->i_subt = m->s_type;
377 /* XXX: why ++? */
378 istk->i_remaining++;
379 /* XXX: why is i_seen_named_member not set? */
380 pop_member();
381 debug_initstack();
382 debug_leave();
383 return;
384 }
385 }
386
387 /* undefined struct/union member: %s */
388 error(101, namedmem->n_name);
389
390 pop_member();
391 istk->i_seen_named_member = true;
392 debug_initstack();
393 debug_leave();
394 return;
395 }
396
397 /*
398 * If the removed element was a structure member, we must go
399 * to the next structure member.
400 */
401 if (istk->i_remaining > 0 && istk->i_type->t_tspec == STRUCT &&
402 !istk->i_seen_named_member) {
403 do {
404 m = istk->i_current_object =
405 istk->i_current_object->s_next;
406 /* XXX: can this assertion be made to fail? */
407 lint_assert(m != NULL);
408 debug_step("pop %s", m->s_name);
409 } while (m->s_bitfield && m->s_name == unnamed);
410 /* XXX: duplicate code for skipping unnamed bit-fields */
411 istk->i_subt = m->s_type;
412 }
413 debug_initstack();
414 debug_leave();
415 }
416
417 /*
418 * Take all entries, including the first which requires a closing brace,
419 * from the stack.
420 */
421 static void
422 initstack_pop_brace(void)
423 {
424 bool brace;
425
426 debug_enter();
427 debug_initstack();
428 do {
429 brace = initstk->i_brace;
430 debug_step("loop brace=%d", brace);
431 initstack_pop_item();
432 } while (!brace);
433 debug_initstack();
434 debug_leave();
435 }
436
437 /*
438 * Take all entries which cannot be used for further initializers from the
439 * stack, but do this only if they do not require a closing brace.
440 */
441 static void
442 initstack_pop_nobrace(void)
443 {
444
445 debug_enter();
446 while (!initstk->i_brace && initstk->i_remaining == 0 &&
447 !initstk->i_array_of_unknown_size)
448 initstack_pop_item();
449 debug_leave();
450 }
451
452 static void
453 initstack_push(void)
454 {
455 initstack_element *istk, *inxt;
456 int cnt;
457 sym_t *m;
458
459 debug_enter();
460 debug_initstack();
461
462 istk = initstk;
463
464 /* Extend an incomplete array type by one element */
465 if (istk->i_remaining == 0) {
466 /*
467 * Inside of other aggregate types must not be an incomplete
468 * type.
469 */
470 lint_assert(istk->i_enclosing->i_enclosing == NULL);
471 lint_assert(istk->i_type->t_tspec == ARRAY);
472 debug_step("extending array of unknown size '%s'",
473 type_name(istk->i_type));
474 istk->i_remaining = 1;
475 istk->i_type->t_dim++;
476 setcomplete(istk->i_type, true);
477 debug_step("extended type is '%s'", type_name(istk->i_type));
478 }
479
480 lint_assert(istk->i_remaining > 0);
481 lint_assert(istk->i_type == NULL || !is_scalar(istk->i_type->t_tspec));
482
483 initstk = xcalloc(1, sizeof (initstack_element));
484 initstk->i_enclosing = istk;
485 initstk->i_type = istk->i_subt;
486 lint_assert(initstk->i_type->t_tspec != FUNC);
487
488 again:
489 istk = initstk;
490
491 debug_step("expecting type '%s'", type_name(istk->i_type));
492 switch (istk->i_type->t_tspec) {
493 case ARRAY:
494 if (namedmem != NULL) {
495 debug_step("ARRAY %s brace=%d",
496 namedmem->n_name, istk->i_brace);
497 goto pop;
498 } else if (istk->i_enclosing->i_seen_named_member) {
499 istk->i_brace = true;
500 debug_step("ARRAY brace=%d, namedmem=%d",
501 istk->i_brace,
502 istk->i_enclosing->i_seen_named_member);
503 }
504
505 if (is_incomplete(istk->i_type) &&
506 istk->i_enclosing->i_enclosing != NULL) {
507 /* initialization of an incomplete type */
508 error(175);
509 initerr = true;
510 debug_initstack();
511 debug_leave();
512 return;
513 }
514 istk->i_subt = istk->i_type->t_subt;
515 istk->i_array_of_unknown_size = is_incomplete(istk->i_type);
516 istk->i_remaining = istk->i_type->t_dim;
517 debug_step("elements array %s[%d] %s",
518 type_name(istk->i_subt), istk->i_remaining,
519 namedmem != NULL ? namedmem->n_name : "*none*");
520 break;
521 case UNION:
522 if (tflag)
523 /* initialization of union is illegal in trad. C */
524 warning(238);
525 /* FALLTHROUGH */
526 case STRUCT:
527 if (is_incomplete(istk->i_type)) {
528 /* initialization of an incomplete type */
529 error(175);
530 initerr = true;
531 debug_initstack();
532 debug_leave();
533 return;
534 }
535 cnt = 0;
536 debug_step("lookup type=%s, name=%s named=%d",
537 type_name(istk->i_type),
538 namedmem != NULL ? namedmem->n_name : "*none*",
539 istk->i_seen_named_member);
540 for (m = istk->i_type->t_str->sou_first_member;
541 m != NULL; m = m->s_next) {
542 if (m->s_bitfield && m->s_name == unnamed)
543 continue;
544 if (namedmem != NULL) {
545 debug_step("named lhs.member=%s, rhs.member=%s",
546 m->s_name, namedmem->n_name);
547 if (strcmp(m->s_name, namedmem->n_name) == 0) {
548 cnt++;
549 break;
550 } else
551 continue;
552 }
553 if (++cnt == 1) {
554 istk->i_current_object = m;
555 istk->i_subt = m->s_type;
556 }
557 }
558 if (namedmem != NULL) {
559 if (m == NULL) {
560 debug_step("pop struct");
561 goto pop;
562 }
563 istk->i_current_object = m;
564 istk->i_subt = m->s_type;
565 istk->i_seen_named_member = true;
566 debug_step("named name=%s", namedmem->n_name);
567 pop_member();
568 cnt = istk->i_type->t_tspec == STRUCT ? 2 : 1;
569 }
570 istk->i_brace = true;
571 debug_step("unnamed type=%s, brace=%d",
572 type_name(
573 istk->i_type != NULL ? istk->i_type : istk->i_subt),
574 istk->i_brace);
575 if (cnt == 0) {
576 /* cannot init. struct/union with no named member */
577 error(179);
578 initerr = true;
579 debug_initstack();
580 debug_leave();
581 return;
582 }
583 istk->i_remaining = istk->i_type->t_tspec == STRUCT ? cnt : 1;
584 break;
585 default:
586 if (namedmem != NULL) {
587 debug_step("pop");
588 pop:
589 inxt = initstk->i_enclosing;
590 free(istk);
591 initstk = inxt;
592 goto again;
593 }
594 istk->i_remaining = 1;
595 break;
596 }
597
598 debug_initstack();
599 debug_leave();
600 }
601
602 static void
603 check_too_many_initializers(void)
604 {
605
606 const initstack_element *istk = initstk;
607 if (istk->i_remaining > 0)
608 return;
609 if (istk->i_array_of_unknown_size || istk->i_seen_named_member)
610 return;
611
612 tspec_t t = istk->i_type->t_tspec;
613 if (t == ARRAY) {
614 /* too many array initializers, expected %d */
615 error(173, istk->i_type->t_dim);
616 } else if (t == STRUCT || t == UNION) {
617 /* too many struct/union initializers */
618 error(172);
619 } else {
620 /* too many initializers */
621 error(174);
622 }
623 initerr = true;
624 }
625
626 static void
627 initstack_next_brace(void)
628 {
629
630 debug_enter();
631 debug_initstack();
632
633 if (initstk->i_type != NULL && is_scalar(initstk->i_type->t_tspec)) {
634 /* invalid initializer type %s */
635 error(176, type_name(initstk->i_type));
636 initerr = true;
637 }
638 if (!initerr)
639 check_too_many_initializers();
640 if (!initerr)
641 initstack_push();
642 if (!initerr) {
643 initstk->i_brace = true;
644 debug_step("%p %s", namedmem, type_name(
645 initstk->i_type != NULL ? initstk->i_type
646 : initstk->i_subt));
647 }
648
649 debug_initstack();
650 debug_leave();
651 }
652
653 static void
654 initstack_next_nobrace(void)
655 {
656 debug_enter();
657 debug_initstack();
658
659 if (initstk->i_type == NULL && !is_scalar(initstk->i_subt->t_tspec)) {
660 /* {}-enclosed initializer required */
661 error(181);
662 }
663
664 if (!initerr)
665 check_too_many_initializers();
666
667 /*
668 * Make sure an entry with a scalar type is at the top of the stack.
669 *
670 * FIXME: Since C99 an initializer for an object with automatic
671 * storage need not be a constant expression anymore. It is
672 * perfectly fine to initialize a struct with a struct expression,
673 * see d_struct_init_nested.c for a demonstration.
674 */
675 while (!initerr) {
676 if ((initstk->i_type != NULL &&
677 is_scalar(initstk->i_type->t_tspec)))
678 break;
679 initstack_push();
680 }
681
682 debug_initstack();
683 debug_leave();
684 }
685
686 void
687 init_lbrace(void)
688 {
689 if (initerr)
690 return;
691
692 debug_enter();
693 debug_initstack();
694
695 if ((initsym->s_scl == AUTO || initsym->s_scl == REG) &&
696 initstk->i_enclosing == NULL) {
697 if (tflag && !is_scalar(initstk->i_subt->t_tspec))
698 /* no automatic aggregate initialization in trad. C */
699 warning(188);
700 }
701
702 /*
703 * Remove all entries which cannot be used for further initializers
704 * and do not expect a closing brace.
705 */
706 initstack_pop_nobrace();
707
708 initstack_next_brace();
709
710 debug_initstack();
711 debug_leave();
712 }
713
714 void
715 init_rbrace(void)
716 {
717 if (initerr)
718 return;
719
720 debug_enter();
721 debug_initstack();
722
723 initstack_pop_brace();
724
725 debug_initstack();
726 debug_leave();
727 }
728
729 /* In traditional C, bit-fields can be initialized only by integer constants. */
730 static void
731 check_bit_field_init(const tnode_t *ln, tspec_t lt, tspec_t rt)
732 {
733 if (tflag &&
734 is_integer(lt) &&
735 ln->tn_type->t_bitfield &&
736 !is_integer(rt)) {
737 /* bit-field initialization is illegal in traditional C */
738 warning(186);
739 }
740 }
741
742 static void
743 check_non_constant_initializer(const tnode_t *tn, scl_t sclass)
744 {
745 if (tn == NULL || tn->tn_op == CON)
746 return;
747
748 sym_t *sym;
749 ptrdiff_t offs;
750 if (constant_addr(tn, &sym, &offs))
751 return;
752
753 if (sclass == AUTO || sclass == REG) {
754 /* non-constant initializer */
755 c99ism(177);
756 } else {
757 /* non-constant initializer */
758 error(177);
759 }
760 }
761
762 void
763 init_using_expr(tnode_t *tn)
764 {
765 tspec_t lt, rt;
766 tnode_t *ln;
767 struct mbl *tmem;
768 scl_t sclass;
769
770 debug_enter();
771 debug_named_member();
772 debug_node(tn, debug_ind);
773 debug_initstack();
774
775 if (initerr || tn == NULL) {
776 debug_leave();
777 return;
778 }
779
780 sclass = initsym->s_scl;
781
782 /*
783 * Do not test for automatic aggregate initialization. If the
784 * initializer starts with a brace we have the warning already.
785 * If not, an error will be printed that the initializer must
786 * be enclosed by braces.
787 */
788
789 /*
790 * Local initialization of non-array-types with only one expression
791 * without braces is done by ASSIGN
792 */
793 if ((sclass == AUTO || sclass == REG) &&
794 initsym->s_type->t_tspec != ARRAY && initstk->i_enclosing == NULL) {
795 debug_step("handing over to ASSIGN");
796 ln = new_name_node(initsym, 0);
797 ln->tn_type = tduptyp(ln->tn_type);
798 ln->tn_type->t_const = false;
799 tn = build(ASSIGN, ln, tn);
800 expr(tn, false, false, false, false);
801 /* XXX: why not clean up the initstack here already? */
802 debug_leave();
803 return;
804 }
805
806 initstack_pop_nobrace();
807
808 if (init_array_using_string(tn)) {
809 debug_step("after initializing the string:");
810 /* XXX: why not clean up the initstack here already? */
811 debug_initstack();
812 debug_leave();
813 return;
814 }
815
816 initstack_next_nobrace();
817 if (initerr || tn == NULL) {
818 debug_initstack();
819 debug_leave();
820 return;
821 }
822
823 initstk->i_remaining--;
824 debug_step("%d elements remaining", initstk->i_remaining);
825
826 /* Create a temporary node for the left side. */
827 ln = tgetblk(sizeof (tnode_t));
828 ln->tn_op = NAME;
829 ln->tn_type = tduptyp(initstk->i_type);
830 ln->tn_type->t_const = false;
831 ln->tn_lvalue = true;
832 ln->tn_sym = initsym; /* better than nothing */
833
834 tn = cconv(tn);
835
836 lt = ln->tn_type->t_tspec;
837 rt = tn->tn_type->t_tspec;
838
839 lint_assert(is_scalar(lt));
840
841 if (!typeok(INIT, 0, ln, tn)) {
842 debug_initstack();
843 debug_leave();
844 return;
845 }
846
847 /*
848 * Store the tree memory. This is necessary because otherwise
849 * expr() would free it.
850 */
851 tmem = tsave();
852 expr(tn, true, false, true, false);
853 trestor(tmem);
854
855 check_bit_field_init(ln, lt, rt);
856
857 if (lt != rt || (initstk->i_type->t_bitfield && tn->tn_op == CON))
858 tn = convert(INIT, 0, initstk->i_type, tn);
859
860 check_non_constant_initializer(tn, sclass);
861
862 debug_initstack();
863 debug_leave();
864 }
865
866
867 /* Initialize a character array or wchar_t array with a string literal. */
868 static bool
869 init_array_using_string(tnode_t *tn)
870 {
871 tspec_t t;
872 initstack_element *istk;
873 int len;
874 strg_t *strg;
875
876 if (tn->tn_op != STRING)
877 return false;
878
879 debug_enter();
880 debug_initstack();
881
882 istk = initstk;
883 strg = tn->tn_string;
884
885 /*
886 * Check if we have an array type which can be initialized by
887 * the string.
888 */
889 if (istk->i_subt != NULL && istk->i_subt->t_tspec == ARRAY) {
890 debug_step("subt array");
891 t = istk->i_subt->t_subt->t_tspec;
892 if (!((strg->st_tspec == CHAR &&
893 (t == CHAR || t == UCHAR || t == SCHAR)) ||
894 (strg->st_tspec == WCHAR && t == WCHAR))) {
895 debug_leave();
896 return false;
897 }
898 /* XXX: duplicate code, see below */
899 /* Put the array at top of stack */
900 initstack_push();
901 istk = initstk;
902 } else if (istk->i_type != NULL && istk->i_type->t_tspec == ARRAY) {
903 debug_step("type array");
904 t = istk->i_type->t_subt->t_tspec;
905 if (!((strg->st_tspec == CHAR &&
906 (t == CHAR || t == UCHAR || t == SCHAR)) ||
907 (strg->st_tspec == WCHAR && t == WCHAR))) {
908 debug_leave();
909 return false;
910 }
911 /* XXX: duplicate code, see above */
912 /*
913 * If the array is already partly initialized, we are
914 * wrong here.
915 */
916 if (istk->i_remaining != istk->i_type->t_dim)
917 debug_leave();
918 return false;
919 } else {
920 debug_leave();
921 return false;
922 }
923
924 /* Get length without trailing NUL character. */
925 len = strg->st_len;
926
927 if (istk->i_array_of_unknown_size) {
928 istk->i_array_of_unknown_size = false;
929 istk->i_type->t_dim = len + 1;
930 setcomplete(istk->i_type, true);
931 } else {
932 if (istk->i_type->t_dim < len) {
933 /* non-null byte ignored in string initializer */
934 warning(187);
935 }
936 }
937
938 /* In every case the array is initialized completely. */
939 istk->i_remaining = 0;
940
941 debug_initstack();
942 debug_leave();
943 return true;
944 }
945