xref: /netbsd-src/usr.bin/xlint/lint1/init.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: init.c,v 1.17 2002/12/06 03:27:39 thorpej 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 #include <sys/cdefs.h>
35 #if defined(__RCSID) && !defined(lint)
36 __RCSID("$NetBSD: init.c,v 1.17 2002/12/06 03:27:39 thorpej Exp $");
37 #endif
38 
39 #include <stdlib.h>
40 #include <string.h>
41 #include <ctype.h>
42 
43 #include "lint1.h"
44 
45 /*
46  * initerr is set as soon as a fatal error occurred in an initialisation.
47  * The effect is that the rest of the initialisation is ignored (parsed
48  * by yacc, expression trees built, but no initialisation takes place).
49  */
50 int	initerr;
51 
52 /* Pointer to the symbol which is to be initialized. */
53 sym_t	*initsym;
54 
55 /* Points to the top element of the initialisation stack. */
56 istk_t	*initstk;
57 
58 typedef struct namlist {
59 	const char *n_name;
60 	struct namlist *n_prev;
61 	struct namlist *n_next;
62 } namlist_t;
63 
64 /* Points to a c9x named member; */
65 namlist_t	*namedmem = NULL;
66 
67 
68 static	void	popi2(void);
69 static	void	popinit(int);
70 static	void	pushinit(void);
71 static	void	testinit(void);
72 static	void	nextinit(int);
73 static	int	strginit(tnode_t *);
74 static	void	memberpop(void);
75 
76 #ifndef DEBUG
77 #define DPRINTF(a)
78 #else
79 #define DPRINTF(a) printf a
80 #endif
81 
82 void
83 memberpush(sb)
84 	sbuf_t *sb;
85 {
86 	namlist_t *nam = xcalloc(1, sizeof (namlist_t));
87 	nam->n_name = sb->sb_name;
88 	DPRINTF(("memberpush = %s\n", nam->n_name));
89 	if (namedmem == NULL) {
90 		nam->n_prev = nam->n_next = nam;
91 		namedmem = nam;
92 	} else {
93 		namedmem->n_prev->n_next = nam;
94 		nam->n_prev = namedmem->n_prev;
95 		nam->n_next = namedmem;
96 		namedmem->n_prev = nam;
97 	}
98 #if 0
99 	nam->n_next = namedmem;
100 	namedmem = nam;
101 #endif
102 }
103 
104 static void
105 memberpop()
106 {
107 	DPRINTF(("memberpop = %s\n", namedmem->n_name));
108 	if (namedmem->n_next == namedmem) {
109 		free(namedmem);
110 		namedmem = NULL;
111 	} else {
112 		namlist_t *nam = namedmem;
113 		namedmem = namedmem->n_next;
114 		free(nam);
115 	}
116 #if 0
117 	namedmem = namedmem->n_next;
118 	free(nam);
119 #endif
120 }
121 
122 
123 /*
124  * Initialize the initialisation stack by putting an entry for the variable
125  * which is to be initialized on it.
126  */
127 void
128 prepinit(void)
129 {
130 	istk_t	*istk;
131 
132 	if (initerr)
133 		return;
134 
135 	/* free memory used in last initialisation */
136 	while ((istk = initstk) != NULL) {
137 		initstk = istk->i_nxt;
138 		free(istk);
139 	}
140 
141 	/*
142 	 * If the type which is to be initialized is an incomplete type,
143 	 * it must be duplicated.
144 	 */
145 	if (initsym->s_type->t_tspec == ARRAY && incompl(initsym->s_type))
146 		initsym->s_type = duptyp(initsym->s_type);
147 
148 	istk = initstk = xcalloc(1, sizeof (istk_t));
149 	istk->i_subt = initsym->s_type;
150 	istk->i_cnt = 1;
151 
152 }
153 
154 static void
155 popi2(void)
156 {
157 #ifdef DEBUG
158 	char	buf[64];
159 #endif
160 	istk_t	*istk;
161 	sym_t	*m;
162 
163 	initstk = (istk = initstk)->i_nxt;
164 	if (initstk == NULL)
165 		LERROR("popi2()");
166 	free(istk);
167 
168 	istk = initstk;
169 
170 	istk->i_cnt--;
171 	if (istk->i_cnt < 0)
172 		LERROR("popi2()");
173 
174 	DPRINTF(("popi2(): %d %s\n", istk->i_cnt,
175 	    namedmem ? namedmem->n_name : "*null*"));
176 	if (istk->i_cnt >= 0 && namedmem != NULL) {
177 		DPRINTF(("popi2(): %d %s %s\n", istk->i_cnt,
178 		    tyname(buf, sizeof(buf), istk->i_type), namedmem->n_name));
179 		for (m = istk->i_type->t_str->memb; m != NULL; m = m->s_nxt) {
180 			if (m->s_field && m->s_name == unnamed)
181 				continue;
182 			if (strcmp(m->s_name, namedmem->n_name) == 0) {
183 				istk->i_subt = m->s_type;
184 				istk->i_cnt++;
185 				memberpop();
186 				return;
187 			}
188 		}
189 		error(101, namedmem->n_name);
190 		memberpop();
191 		istk->i_namedmem = 1;
192 		return;
193 	}
194 	/*
195 	 * If the removed element was a structure member, we must go
196 	 * to the next structure member.
197 	 */
198 	if (istk->i_cnt > 0 && istk->i_type->t_tspec == STRUCT &&
199 	    !istk->i_namedmem) {
200 		do {
201 			m = istk->i_mem = istk->i_mem->s_nxt;
202 			if (m == NULL)
203 				LERROR("popi2()");
204 		} while (m->s_field && m->s_name == unnamed);
205 		istk->i_subt = m->s_type;
206 	}
207 }
208 
209 static void
210 popinit(int brace)
211 {
212 	DPRINTF(("popinit(%d)\n", brace));
213 
214 	if (brace) {
215 		/*
216 		 * Take all entries, including the first which requires
217 		 * a closing brace, from the stack.
218 		 */
219 		do {
220 			brace = initstk->i_brace;
221 			popi2();
222 		} while (!brace);
223 	} else {
224 		/*
225 		 * Take all entries which cannot be used for further
226 		 * initializers from the stack, but do this only if
227 		 * they do not require a closing brace.
228 		 */
229 		while (!initstk->i_brace &&
230 		       initstk->i_cnt == 0 && !initstk->i_nolimit) {
231 			popi2();
232 		}
233 	}
234 }
235 
236 static void
237 pushinit(void)
238 {
239 #ifdef DEBUG
240 	char	buf[64];
241 #endif
242 	istk_t	*istk;
243 	int	cnt;
244 	sym_t	*m;
245 
246 	istk = initstk;
247 
248 	/* Extend an incomplete array type by one element */
249 	if (istk->i_cnt == 0) {
250 		DPRINTF(("pushinit(extend) %s\n", tyname(buf, sizeof(buf),
251 		    istk->i_type)));
252 		/*
253 		 * Inside of other aggregate types must not be an incomplete
254 		 * type.
255 		 */
256 		if (istk->i_nxt->i_nxt != NULL)
257 			LERROR("pushinit()");
258 		istk->i_cnt = 1;
259 		if (istk->i_type->t_tspec != ARRAY)
260 			LERROR("pushinit()");
261 		istk->i_type->t_dim++;
262 		/* from now its an complete type */
263 		setcompl(istk->i_type, 0);
264 	}
265 
266 	if (istk->i_cnt <= 0)
267 		LERROR("pushinit()");
268 	if (istk->i_type != NULL && issclt(istk->i_type->t_tspec))
269 		LERROR("pushinit()");
270 
271 	initstk = xcalloc(1, sizeof (istk_t));
272 	initstk->i_nxt = istk;
273 	initstk->i_type = istk->i_subt;
274 	if (initstk->i_type->t_tspec == FUNC)
275 		LERROR("pushinit()");
276 
277 again:
278 	istk = initstk;
279 
280 	DPRINTF(("pushinit(%s)\n", tyname(buf, sizeof(buf), istk->i_type)));
281 	switch (istk->i_type->t_tspec) {
282 	case ARRAY:
283 		if (namedmem) {
284 			DPRINTF(("pushinit ARRAY %s\n", namedmem->n_name));
285 			free(istk);
286 			initstk = initstk->i_nxt;
287 			goto again;
288 		}
289 		if (incompl(istk->i_type) && istk->i_nxt->i_nxt != NULL) {
290 			/* initialisation of an incomplete type */
291 			error(175);
292 			initerr = 1;
293 			return;
294 		}
295 		istk->i_subt = istk->i_type->t_subt;
296 		istk->i_nolimit = incompl(istk->i_type);
297 		istk->i_cnt = istk->i_type->t_dim;
298 		DPRINTF(("elements array %s[%d] %s\n",
299 		    tyname(buf, sizeof(buf), istk->i_subt), istk->i_cnt,
300 		    namedmem ? namedmem->n_name : "*none*"));
301 		break;
302 	case UNION:
303 		if (tflag)
304 			/* initialisation of union is illegal in trad. C */
305 			warning(238);
306 		/* FALLTHROUGH */
307 	case STRUCT:
308 		if (incompl(istk->i_type)) {
309 			/* initialisation of an incomplete type */
310 			error(175);
311 			initerr = 1;
312 			return;
313 		}
314 		cnt = 0;
315 		DPRINTF(("2. member lookup %s %s\n",
316 		    tyname(buf, sizeof(buf), istk->i_type),
317 		    namedmem ? namedmem->n_name : "*none*"));
318 		for (m = istk->i_type->t_str->memb; m != NULL; m = m->s_nxt) {
319 			if (m->s_field && m->s_name == unnamed)
320 				continue;
321 			if (namedmem != NULL) {
322 				DPRINTF(("pushinit():[member:%s, looking:%s]\n",
323 				    m->s_name, namedmem->n_name));
324 				if (strcmp(m->s_name, namedmem->n_name) == 0) {
325 					cnt++;
326 					break;
327 				} else
328 					continue;
329 			}
330 			if (++cnt == 1) {
331 				istk->i_mem = m;
332 				istk->i_subt = m->s_type;
333 			}
334 		}
335 		if (namedmem != NULL) {
336 			istk->i_namedmem = 1;
337 			if (m == NULL) {
338 				error(101, namedmem->n_name);
339 				initerr = 1;
340 			} else {
341 				istk->i_mem = m;
342 				istk->i_subt = m->s_type;
343 			}
344 			memberpop();
345 			cnt = istk->i_type->t_tspec == STRUCT ? 2 : 1;
346 		}
347 		if (cnt == 0) {
348 			/* cannot init. struct/union with no named member */
349 			error(179);
350 			initerr = 1;
351 			return;
352 		}
353 		istk->i_cnt = istk->i_type->t_tspec == STRUCT ? cnt : 1;
354 		break;
355 	default:
356 		if (namedmem) {
357 			DPRINTF(("pushinit(): pop\n"));
358 			free(istk);
359 			initstk = initstk->i_nxt;
360 			goto again;
361 		}
362 		istk->i_cnt = 1;
363 		break;
364 	}
365 }
366 
367 static void
368 testinit(void)
369 {
370 	istk_t	*istk;
371 
372 	istk = initstk;
373 
374 	/*
375 	 * If a closing brace is expected we have at least one initializer
376 	 * too much.
377 	 */
378 	if (istk->i_cnt == 0 && !istk->i_nolimit && !istk->i_namedmem) {
379 		switch (istk->i_type->t_tspec) {
380 		case ARRAY:
381 			/* too many array initializers */
382 			error(173);
383 			break;
384 		case STRUCT:
385 		case UNION:
386 			/* too many struct/union initializers */
387 			error(172);
388 			break;
389 		default:
390 			/* too many initializers */
391 			error(174);
392 			break;
393 		}
394 		initerr = 1;
395 	}
396 }
397 
398 static void
399 nextinit(int brace)
400 {
401 	char buf[64];
402 
403 	DPRINTF(("nextinit(%d)\n", brace));
404 	if (!brace) {
405 		if (initstk->i_type == NULL &&
406 		    !issclt(initstk->i_subt->t_tspec)) {
407 			/* {}-enclosed initializer required */
408 			error(181);
409 		}
410 		/*
411 		 * Make sure an entry with a scalar type is at the top
412 		 * of the stack.
413 		 */
414 		if (!initerr)
415 			testinit();
416 		while (!initerr && (initstk->i_type == NULL ||
417 				    !issclt(initstk->i_type->t_tspec))) {
418 			if (!initerr)
419 				pushinit();
420 		}
421 	} else {
422 		if (initstk->i_type != NULL &&
423 		    issclt(initstk->i_type->t_tspec)) {
424 			/* invalid initializer */
425 			error(176, tyname(buf, sizeof(buf), initstk->i_type));
426 			initerr = 1;
427 		}
428 		if (!initerr)
429 			testinit();
430 		if (!initerr)
431 			pushinit();
432 		if (!initerr)
433 			initstk->i_brace = 1;
434 	}
435 }
436 
437 void
438 initlbr(void)
439 {
440 
441 	if (initerr)
442 		return;
443 
444 	if ((initsym->s_scl == AUTO || initsym->s_scl == REG) &&
445 	    initstk->i_nxt == NULL) {
446 		if (tflag && !issclt(initstk->i_subt->t_tspec))
447 			/* no automatic aggregate initialization in trad. C*/
448 			warning(188);
449 	}
450 
451 	/*
452 	 * Remove all entries which cannot be used for further initializers
453 	 * and do not expect a closing brace.
454 	 */
455 	popinit(0);
456 
457 	nextinit(1);
458 }
459 
460 void
461 initrbr(void)
462 {
463 
464 	if (initerr)
465 		return;
466 
467 	popinit(1);
468 }
469 
470 void
471 mkinit(tnode_t *tn)
472 {
473 	ptrdiff_t offs;
474 	sym_t	*sym;
475 	tspec_t	lt, rt;
476 	tnode_t	*ln;
477 	struct	mbl *tmem;
478 	scl_t	sc;
479 #ifdef DEBUG
480 	char	buf[64];
481 #endif
482 
483 	DPRINTF(("mkinit(%s)\n", tyname(buf, sizeof(buf), tn->tn_type)));
484 	if (initerr || tn == NULL)
485 		goto end;
486 
487 	sc = initsym->s_scl;
488 
489 	/*
490 	 * Do not test for automatic aggregate initialisation. If the
491 	 * initializer starts with a brace we have the warning already.
492 	 * If not, an error will be printed that the initializer must
493 	 * be enclosed by braces.
494 	 */
495 
496 	/*
497 	 * Local initialisation of non-array-types with only one expression
498 	 * without braces is done by ASSIGN
499 	 */
500 	if ((sc == AUTO || sc == REG) &&
501 	    initsym->s_type->t_tspec != ARRAY && initstk->i_nxt == NULL) {
502 		ln = getnnode(initsym, 0);
503 		ln->tn_type = tduptyp(ln->tn_type);
504 		ln->tn_type->t_const = 0;
505 		tn = build(ASSIGN, ln, tn);
506 		expr(tn, 0, 0, 1);
507 		goto end;
508 	}
509 
510 	/*
511 	 * Remove all entries which cannot be used for further initializers
512 	 * and do not require a closing brace.
513 	 */
514 	popinit(0);
515 
516 	/* Initialisations by strings are done in strginit(). */
517 	if (strginit(tn))
518 		goto end;
519 
520 	nextinit(0);
521 	if (initerr || tn == NULL)
522 		goto end;
523 
524 	initstk->i_cnt--;
525 	DPRINTF(("mkinit() cnt=%d tn=%p\n", initstk->i_cnt, tn));
526 	/* Create a temporary node for the left side. */
527 	ln = tgetblk(sizeof (tnode_t));
528 	ln->tn_op = NAME;
529 	ln->tn_type = tduptyp(initstk->i_type);
530 	ln->tn_type->t_const = 0;
531 	ln->tn_lvalue = 1;
532 	ln->tn_sym = initsym;		/* better than nothing */
533 
534 	tn = cconv(tn);
535 
536 	lt = ln->tn_type->t_tspec;
537 	rt = tn->tn_type->t_tspec;
538 
539 	if (!issclt(lt))
540 		LERROR("mkinit()");
541 
542 	if (!typeok(INIT, 0, ln, tn))
543 		goto end;
544 
545 	/*
546 	 * Store the tree memory. This is nessesary because otherwise
547 	 * expr() would free it.
548 	 */
549 	tmem = tsave();
550 	expr(tn, 1, 0, 1);
551 	trestor(tmem);
552 
553 	if (isityp(lt) && ln->tn_type->t_isfield && !isityp(rt)) {
554 		/*
555 		 * Bit-fields can be initialized in trad. C only by integer
556 		 * constants.
557 		 */
558 		if (tflag)
559 			/* bit-field initialisation is illegal in trad. C */
560 			warning(186);
561 	}
562 
563 	if (lt != rt || (initstk->i_type->t_isfield && tn->tn_op == CON))
564 		tn = convert(INIT, 0, initstk->i_type, tn);
565 
566 	if (tn != NULL && tn->tn_op != CON) {
567 		sym = NULL;
568 		offs = 0;
569 		if (conaddr(tn, &sym, &offs) == -1) {
570 			if (sc == AUTO || sc == REG) {
571 				/* non-constant initializer */
572 				(void)gnuism(177);
573 			} else {
574 				/* non-constant initializer */
575 				error(177);
576 			}
577 		}
578 	}
579 
580  end:
581 	/*
582 	 * We only free the block, if we are not a compound declaration
583 	 * We know that the only symbols that start with a digit are the
584 	 * ones we allocate with mktempsym() for compound declarations
585 	 */
586 	if (!isdigit((unsigned char)initsym->s_name[0]))
587 		tfreeblk();
588 }
589 
590 
591 static int
592 strginit(tnode_t *tn)
593 {
594 	tspec_t	t;
595 	istk_t	*istk;
596 	int	len;
597 	strg_t	*strg;
598 
599 	if (tn->tn_op != STRING)
600 		return (0);
601 
602 	istk = initstk;
603 	strg = tn->tn_strg;
604 
605 	/*
606 	 * Check if we have an array type which can be initialized by
607 	 * the string.
608 	 */
609 	if (istk->i_subt != NULL && istk->i_subt->t_tspec == ARRAY) {
610 		t = istk->i_subt->t_subt->t_tspec;
611 		if (!((strg->st_tspec == CHAR &&
612 		       (t == CHAR || t == UCHAR || t == SCHAR)) ||
613 		      (strg->st_tspec == WCHAR && t == WCHAR))) {
614 			return (0);
615 		}
616 		/* Put the array at top of stack */
617 		pushinit();
618 		istk = initstk;
619 	} else if (istk->i_type != NULL && istk->i_type->t_tspec == ARRAY) {
620 		t = istk->i_type->t_subt->t_tspec;
621 		if (!((strg->st_tspec == CHAR &&
622 		       (t == CHAR || t == UCHAR || t == SCHAR)) ||
623 		      (strg->st_tspec == WCHAR && t == WCHAR))) {
624 			return (0);
625 		}
626 		/*
627 		 * If the array is already partly initialized, we are
628 		 * wrong here.
629 		 */
630 		if (istk->i_cnt != istk->i_type->t_dim)
631 			return (0);
632 	} else {
633 		return (0);
634 	}
635 
636 	/* Get length without trailing NUL character. */
637 	len = strg->st_len;
638 
639 	if (istk->i_nolimit) {
640 		istk->i_nolimit = 0;
641 		istk->i_type->t_dim = len + 1;
642 		/* from now complete type */
643 		setcompl(istk->i_type, 0);
644 	} else {
645 		if (istk->i_type->t_dim < len) {
646 			/* non-null byte ignored in string initializer */
647 			warning(187);
648 		}
649 	}
650 
651 	/* In every case the array is initialized completely. */
652 	istk->i_cnt = 0;
653 
654 	return (1);
655 }
656