xref: /netbsd-src/usr.bin/xlint/lint1/init.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: init.c,v 1.18 2004/06/20 22:20:17 jmc 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 1.18 2004/06/20 22:20:17 jmc Exp $");
41 #endif
42 
43 #include <stdlib.h>
44 #include <string.h>
45 #include <ctype.h>
46 
47 #include "lint1.h"
48 
49 /*
50  * initerr is set as soon as a fatal error occurred in an initialisation.
51  * The effect is that the rest of the initialisation is ignored (parsed
52  * by yacc, expression trees built, but no initialisation takes place).
53  */
54 int	initerr;
55 
56 /* Pointer to the symbol which is to be initialized. */
57 sym_t	*initsym;
58 
59 /* Points to the top element of the initialisation stack. */
60 istk_t	*initstk;
61 
62 typedef struct namlist {
63 	const char *n_name;
64 	struct namlist *n_prev;
65 	struct namlist *n_next;
66 } namlist_t;
67 
68 /* Points to a c9x named member; */
69 namlist_t	*namedmem = NULL;
70 
71 
72 static	void	popi2(void);
73 static	void	popinit(int);
74 static	void	pushinit(void);
75 static	void	testinit(void);
76 static	void	nextinit(int);
77 static	int	strginit(tnode_t *);
78 static	void	memberpop(void);
79 
80 #ifndef DEBUG
81 #define DPRINTF(a)
82 #else
83 #define DPRINTF(a) printf a
84 #endif
85 
86 void
87 memberpush(sb)
88 	sbuf_t *sb;
89 {
90 	namlist_t *nam = xcalloc(1, sizeof (namlist_t));
91 	nam->n_name = sb->sb_name;
92 	DPRINTF(("memberpush = %s\n", nam->n_name));
93 	if (namedmem == NULL) {
94 		nam->n_prev = nam->n_next = nam;
95 		namedmem = nam;
96 	} else {
97 		namedmem->n_prev->n_next = nam;
98 		nam->n_prev = namedmem->n_prev;
99 		nam->n_next = namedmem;
100 		namedmem->n_prev = nam;
101 	}
102 #if 0
103 	nam->n_next = namedmem;
104 	namedmem = nam;
105 #endif
106 }
107 
108 static void
109 memberpop()
110 {
111 	DPRINTF(("memberpop = %s\n", namedmem->n_name));
112 	if (namedmem->n_next == namedmem) {
113 		free(namedmem);
114 		namedmem = NULL;
115 	} else {
116 		namlist_t *nam = namedmem;
117 		namedmem = namedmem->n_next;
118 		free(nam);
119 	}
120 #if 0
121 	namedmem = namedmem->n_next;
122 	free(nam);
123 #endif
124 }
125 
126 
127 /*
128  * Initialize the initialisation stack by putting an entry for the variable
129  * which is to be initialized on it.
130  */
131 void
132 prepinit(void)
133 {
134 	istk_t	*istk;
135 
136 	if (initerr)
137 		return;
138 
139 	/* free memory used in last initialisation */
140 	while ((istk = initstk) != NULL) {
141 		initstk = istk->i_nxt;
142 		free(istk);
143 	}
144 
145 	/*
146 	 * If the type which is to be initialized is an incomplete type,
147 	 * it must be duplicated.
148 	 */
149 	if (initsym->s_type->t_tspec == ARRAY && incompl(initsym->s_type))
150 		initsym->s_type = duptyp(initsym->s_type);
151 
152 	istk = initstk = xcalloc(1, sizeof (istk_t));
153 	istk->i_subt = initsym->s_type;
154 	istk->i_cnt = 1;
155 
156 }
157 
158 static void
159 popi2(void)
160 {
161 #ifdef DEBUG
162 	char	buf[64];
163 #endif
164 	istk_t	*istk;
165 	sym_t	*m;
166 
167 	initstk = (istk = initstk)->i_nxt;
168 	if (initstk == NULL)
169 		LERROR("popi2()");
170 	free(istk);
171 
172 	istk = initstk;
173 
174 	istk->i_cnt--;
175 	if (istk->i_cnt < 0)
176 		LERROR("popi2()");
177 
178 	DPRINTF(("popi2(): %d %s\n", istk->i_cnt,
179 	    namedmem ? namedmem->n_name : "*null*"));
180 	if (istk->i_cnt >= 0 && namedmem != NULL) {
181 		DPRINTF(("popi2(): %d %s %s\n", istk->i_cnt,
182 		    tyname(buf, sizeof(buf), istk->i_type), namedmem->n_name));
183 		for (m = istk->i_type->t_str->memb; m != NULL; m = m->s_nxt) {
184 			if (m->s_field && m->s_name == unnamed)
185 				continue;
186 			if (strcmp(m->s_name, namedmem->n_name) == 0) {
187 				istk->i_subt = m->s_type;
188 				istk->i_cnt++;
189 				memberpop();
190 				return;
191 			}
192 		}
193 		error(101, namedmem->n_name);
194 		memberpop();
195 		istk->i_namedmem = 1;
196 		return;
197 	}
198 	/*
199 	 * If the removed element was a structure member, we must go
200 	 * to the next structure member.
201 	 */
202 	if (istk->i_cnt > 0 && istk->i_type->t_tspec == STRUCT &&
203 	    !istk->i_namedmem) {
204 		do {
205 			m = istk->i_mem = istk->i_mem->s_nxt;
206 			if (m == NULL)
207 				LERROR("popi2()");
208 		} while (m->s_field && m->s_name == unnamed);
209 		istk->i_subt = m->s_type;
210 	}
211 }
212 
213 static void
214 popinit(int brace)
215 {
216 	DPRINTF(("popinit(%d)\n", brace));
217 
218 	if (brace) {
219 		/*
220 		 * Take all entries, including the first which requires
221 		 * a closing brace, from the stack.
222 		 */
223 		do {
224 			brace = initstk->i_brace;
225 			popi2();
226 		} while (!brace);
227 	} else {
228 		/*
229 		 * Take all entries which cannot be used for further
230 		 * initializers from the stack, but do this only if
231 		 * they do not require a closing brace.
232 		 */
233 		while (!initstk->i_brace &&
234 		       initstk->i_cnt == 0 && !initstk->i_nolimit) {
235 			popi2();
236 		}
237 	}
238 }
239 
240 static void
241 pushinit(void)
242 {
243 #ifdef DEBUG
244 	char	buf[64];
245 #endif
246 	istk_t	*istk;
247 	int	cnt;
248 	sym_t	*m;
249 
250 	istk = initstk;
251 
252 	/* Extend an incomplete array type by one element */
253 	if (istk->i_cnt == 0) {
254 		DPRINTF(("pushinit(extend) %s\n", tyname(buf, sizeof(buf),
255 		    istk->i_type)));
256 		/*
257 		 * Inside of other aggregate types must not be an incomplete
258 		 * type.
259 		 */
260 		if (istk->i_nxt->i_nxt != NULL)
261 			LERROR("pushinit()");
262 		istk->i_cnt = 1;
263 		if (istk->i_type->t_tspec != ARRAY)
264 			LERROR("pushinit()");
265 		istk->i_type->t_dim++;
266 		/* from now its an complete type */
267 		setcompl(istk->i_type, 0);
268 	}
269 
270 	if (istk->i_cnt <= 0)
271 		LERROR("pushinit()");
272 	if (istk->i_type != NULL && issclt(istk->i_type->t_tspec))
273 		LERROR("pushinit()");
274 
275 	initstk = xcalloc(1, sizeof (istk_t));
276 	initstk->i_nxt = istk;
277 	initstk->i_type = istk->i_subt;
278 	if (initstk->i_type->t_tspec == FUNC)
279 		LERROR("pushinit()");
280 
281 again:
282 	istk = initstk;
283 
284 	DPRINTF(("pushinit(%s)\n", tyname(buf, sizeof(buf), istk->i_type)));
285 	switch (istk->i_type->t_tspec) {
286 	case ARRAY:
287 		if (namedmem) {
288 			DPRINTF(("pushinit ARRAY %s\n", namedmem->n_name));
289 			free(istk);
290 			initstk = initstk->i_nxt;
291 			goto again;
292 		}
293 		if (incompl(istk->i_type) && istk->i_nxt->i_nxt != NULL) {
294 			/* initialisation of an incomplete type */
295 			error(175);
296 			initerr = 1;
297 			return;
298 		}
299 		istk->i_subt = istk->i_type->t_subt;
300 		istk->i_nolimit = incompl(istk->i_type);
301 		istk->i_cnt = istk->i_type->t_dim;
302 		DPRINTF(("elements array %s[%d] %s\n",
303 		    tyname(buf, sizeof(buf), istk->i_subt), istk->i_cnt,
304 		    namedmem ? namedmem->n_name : "*none*"));
305 		break;
306 	case UNION:
307 		if (tflag)
308 			/* initialisation of union is illegal in trad. C */
309 			warning(238);
310 		/* FALLTHROUGH */
311 	case STRUCT:
312 		if (incompl(istk->i_type)) {
313 			/* initialisation of an incomplete type */
314 			error(175);
315 			initerr = 1;
316 			return;
317 		}
318 		cnt = 0;
319 		DPRINTF(("2. member lookup %s %s\n",
320 		    tyname(buf, sizeof(buf), istk->i_type),
321 		    namedmem ? namedmem->n_name : "*none*"));
322 		for (m = istk->i_type->t_str->memb; m != NULL; m = m->s_nxt) {
323 			if (m->s_field && m->s_name == unnamed)
324 				continue;
325 			if (namedmem != NULL) {
326 				DPRINTF(("pushinit():[member:%s, looking:%s]\n",
327 				    m->s_name, namedmem->n_name));
328 				if (strcmp(m->s_name, namedmem->n_name) == 0) {
329 					cnt++;
330 					break;
331 				} else
332 					continue;
333 			}
334 			if (++cnt == 1) {
335 				istk->i_mem = m;
336 				istk->i_subt = m->s_type;
337 			}
338 		}
339 		if (namedmem != NULL) {
340 			istk->i_namedmem = 1;
341 			if (m == NULL) {
342 				error(101, namedmem->n_name);
343 				initerr = 1;
344 			} else {
345 				istk->i_mem = m;
346 				istk->i_subt = m->s_type;
347 			}
348 			memberpop();
349 			cnt = istk->i_type->t_tspec == STRUCT ? 2 : 1;
350 		}
351 		if (cnt == 0) {
352 			/* cannot init. struct/union with no named member */
353 			error(179);
354 			initerr = 1;
355 			return;
356 		}
357 		istk->i_cnt = istk->i_type->t_tspec == STRUCT ? cnt : 1;
358 		break;
359 	default:
360 		if (namedmem) {
361 			DPRINTF(("pushinit(): pop\n"));
362 			free(istk);
363 			initstk = initstk->i_nxt;
364 			goto again;
365 		}
366 		istk->i_cnt = 1;
367 		break;
368 	}
369 }
370 
371 static void
372 testinit(void)
373 {
374 	istk_t	*istk;
375 
376 	istk = initstk;
377 
378 	/*
379 	 * If a closing brace is expected we have at least one initializer
380 	 * too much.
381 	 */
382 	if (istk->i_cnt == 0 && !istk->i_nolimit && !istk->i_namedmem) {
383 		switch (istk->i_type->t_tspec) {
384 		case ARRAY:
385 			/* too many array initializers */
386 			error(173);
387 			break;
388 		case STRUCT:
389 		case UNION:
390 			/* too many struct/union initializers */
391 			error(172);
392 			break;
393 		default:
394 			/* too many initializers */
395 			error(174);
396 			break;
397 		}
398 		initerr = 1;
399 	}
400 }
401 
402 static void
403 nextinit(int brace)
404 {
405 	char buf[64];
406 
407 	DPRINTF(("nextinit(%d)\n", brace));
408 	if (!brace) {
409 		if (initstk->i_type == NULL &&
410 		    !issclt(initstk->i_subt->t_tspec)) {
411 			/* {}-enclosed initializer required */
412 			error(181);
413 		}
414 		/*
415 		 * Make sure an entry with a scalar type is at the top
416 		 * of the stack.
417 		 */
418 		if (!initerr)
419 			testinit();
420 		while (!initerr && (initstk->i_type == NULL ||
421 				    !issclt(initstk->i_type->t_tspec))) {
422 			if (!initerr)
423 				pushinit();
424 		}
425 	} else {
426 		if (initstk->i_type != NULL &&
427 		    issclt(initstk->i_type->t_tspec)) {
428 			/* invalid initializer */
429 			error(176, tyname(buf, sizeof(buf), initstk->i_type));
430 			initerr = 1;
431 		}
432 		if (!initerr)
433 			testinit();
434 		if (!initerr)
435 			pushinit();
436 		if (!initerr)
437 			initstk->i_brace = 1;
438 	}
439 }
440 
441 void
442 initlbr(void)
443 {
444 
445 	if (initerr)
446 		return;
447 
448 	if ((initsym->s_scl == AUTO || initsym->s_scl == REG) &&
449 	    initstk->i_nxt == NULL) {
450 		if (tflag && !issclt(initstk->i_subt->t_tspec))
451 			/* no automatic aggregate initialization in trad. C*/
452 			warning(188);
453 	}
454 
455 	/*
456 	 * Remove all entries which cannot be used for further initializers
457 	 * and do not expect a closing brace.
458 	 */
459 	popinit(0);
460 
461 	nextinit(1);
462 }
463 
464 void
465 initrbr(void)
466 {
467 
468 	if (initerr)
469 		return;
470 
471 	popinit(1);
472 }
473 
474 void
475 mkinit(tnode_t *tn)
476 {
477 	ptrdiff_t offs;
478 	sym_t	*sym;
479 	tspec_t	lt, rt;
480 	tnode_t	*ln;
481 	struct	mbl *tmem;
482 	scl_t	sc;
483 #ifdef DEBUG
484 	char	buf[64];
485 #endif
486 
487 	DPRINTF(("mkinit(%s)\n", tyname(buf, sizeof(buf), tn->tn_type)));
488 	if (initerr || tn == NULL)
489 		goto end;
490 
491 	sc = initsym->s_scl;
492 
493 	/*
494 	 * Do not test for automatic aggregate initialisation. If the
495 	 * initializer starts with a brace we have the warning already.
496 	 * If not, an error will be printed that the initializer must
497 	 * be enclosed by braces.
498 	 */
499 
500 	/*
501 	 * Local initialisation of non-array-types with only one expression
502 	 * without braces is done by ASSIGN
503 	 */
504 	if ((sc == AUTO || sc == REG) &&
505 	    initsym->s_type->t_tspec != ARRAY && initstk->i_nxt == NULL) {
506 		ln = getnnode(initsym, 0);
507 		ln->tn_type = tduptyp(ln->tn_type);
508 		ln->tn_type->t_const = 0;
509 		tn = build(ASSIGN, ln, tn);
510 		expr(tn, 0, 0, 1);
511 		goto end;
512 	}
513 
514 	/*
515 	 * Remove all entries which cannot be used for further initializers
516 	 * and do not require a closing brace.
517 	 */
518 	popinit(0);
519 
520 	/* Initialisations by strings are done in strginit(). */
521 	if (strginit(tn))
522 		goto end;
523 
524 	nextinit(0);
525 	if (initerr || tn == NULL)
526 		goto end;
527 
528 	initstk->i_cnt--;
529 	DPRINTF(("mkinit() cnt=%d tn=%p\n", initstk->i_cnt, tn));
530 	/* Create a temporary node for the left side. */
531 	ln = tgetblk(sizeof (tnode_t));
532 	ln->tn_op = NAME;
533 	ln->tn_type = tduptyp(initstk->i_type);
534 	ln->tn_type->t_const = 0;
535 	ln->tn_lvalue = 1;
536 	ln->tn_sym = initsym;		/* better than nothing */
537 
538 	tn = cconv(tn);
539 
540 	lt = ln->tn_type->t_tspec;
541 	rt = tn->tn_type->t_tspec;
542 
543 	if (!issclt(lt))
544 		LERROR("mkinit()");
545 
546 	if (!typeok(INIT, 0, ln, tn))
547 		goto end;
548 
549 	/*
550 	 * Store the tree memory. This is nessesary because otherwise
551 	 * expr() would free it.
552 	 */
553 	tmem = tsave();
554 	expr(tn, 1, 0, 1);
555 	trestor(tmem);
556 
557 	if (isityp(lt) && ln->tn_type->t_isfield && !isityp(rt)) {
558 		/*
559 		 * Bit-fields can be initialized in trad. C only by integer
560 		 * constants.
561 		 */
562 		if (tflag)
563 			/* bit-field initialisation is illegal in trad. C */
564 			warning(186);
565 	}
566 
567 	if (lt != rt || (initstk->i_type->t_isfield && tn->tn_op == CON))
568 		tn = convert(INIT, 0, initstk->i_type, tn);
569 
570 	if (tn != NULL && tn->tn_op != CON) {
571 		sym = NULL;
572 		offs = 0;
573 		if (conaddr(tn, &sym, &offs) == -1) {
574 			if (sc == AUTO || sc == REG) {
575 				/* non-constant initializer */
576 				(void)gnuism(177);
577 			} else {
578 				/* non-constant initializer */
579 				error(177);
580 			}
581 		}
582 	}
583 
584  end:
585 	/*
586 	 * We only free the block, if we are not a compound declaration
587 	 * We know that the only symbols that start with a digit are the
588 	 * ones we allocate with mktempsym() for compound declarations
589 	 */
590 	if (!isdigit((unsigned char)initsym->s_name[0]))
591 		tfreeblk();
592 }
593 
594 
595 static int
596 strginit(tnode_t *tn)
597 {
598 	tspec_t	t;
599 	istk_t	*istk;
600 	int	len;
601 	strg_t	*strg;
602 
603 	if (tn->tn_op != STRING)
604 		return (0);
605 
606 	istk = initstk;
607 	strg = tn->tn_strg;
608 
609 	/*
610 	 * Check if we have an array type which can be initialized by
611 	 * the string.
612 	 */
613 	if (istk->i_subt != NULL && istk->i_subt->t_tspec == ARRAY) {
614 		t = istk->i_subt->t_subt->t_tspec;
615 		if (!((strg->st_tspec == CHAR &&
616 		       (t == CHAR || t == UCHAR || t == SCHAR)) ||
617 		      (strg->st_tspec == WCHAR && t == WCHAR))) {
618 			return (0);
619 		}
620 		/* Put the array at top of stack */
621 		pushinit();
622 		istk = initstk;
623 	} else if (istk->i_type != NULL && istk->i_type->t_tspec == ARRAY) {
624 		t = istk->i_type->t_subt->t_tspec;
625 		if (!((strg->st_tspec == CHAR &&
626 		       (t == CHAR || t == UCHAR || t == SCHAR)) ||
627 		      (strg->st_tspec == WCHAR && t == WCHAR))) {
628 			return (0);
629 		}
630 		/*
631 		 * If the array is already partly initialized, we are
632 		 * wrong here.
633 		 */
634 		if (istk->i_cnt != istk->i_type->t_dim)
635 			return (0);
636 	} else {
637 		return (0);
638 	}
639 
640 	/* Get length without trailing NUL character. */
641 	len = strg->st_len;
642 
643 	if (istk->i_nolimit) {
644 		istk->i_nolimit = 0;
645 		istk->i_type->t_dim = len + 1;
646 		/* from now complete type */
647 		setcompl(istk->i_type, 0);
648 	} else {
649 		if (istk->i_type->t_dim < len) {
650 			/* non-null byte ignored in string initializer */
651 			warning(187);
652 		}
653 	}
654 
655 	/* In every case the array is initialized completely. */
656 	istk->i_cnt = 0;
657 
658 	return (1);
659 }
660