xref: /netbsd-src/usr.bin/xlint/lint1/init.c (revision f89f6560d453f5e37386cc7938c072d2f528b9fa)
1 /*	$NetBSD: init.c,v 1.26 2014/11/20 20:49:06 christos 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 1.26 2014/11/20 20:49:06 christos 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(("%s: %s\n", __func__, 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(("%s: %s\n", __func__, 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 	DPRINTF(("%s+(%s): brace=%d count=%d namedmem %d\n", __func__,
168 	    tyname(buf, sizeof(buf),
169 	    initstk->i_type ? initstk->i_type : initstk->i_subt),
170 	    initstk->i_brace, initstk->i_cnt, initstk->i_namedmem));
171 	initstk = (istk = initstk)->i_nxt;
172 	free(istk);
173 
174 	istk = initstk;
175 	if (istk == NULL)
176 		LERROR("popi2()");
177 
178 	DPRINTF(("%s-(%s): brace=%d count=%d namedmem %d\n", __func__,
179 	    tyname(buf, sizeof(buf),
180 	    initstk->i_type ? initstk->i_type : initstk->i_subt),
181 	    initstk->i_brace, initstk->i_cnt, initstk->i_namedmem));
182 
183 	istk->i_cnt--;
184 	if (istk->i_cnt < 0)
185 		LERROR("popi2()");
186 
187 	DPRINTF(("%s(): %d %s\n", __func__, istk->i_cnt,
188 	    namedmem ? namedmem->n_name : "*null*"));
189 	if (istk->i_cnt >= 0 && namedmem != NULL) {
190 		DPRINTF(("%s(): %d %s %s\n", __func__, istk->i_cnt,
191 		    tyname(buf, sizeof(buf), istk->i_type), namedmem->n_name));
192 		for (m = istk->i_type->t_str->memb; m != NULL; m = m->s_nxt) {
193 			DPRINTF(("%s(): pop [%s %s]\n", __func__,
194 			    namedmem->n_name, m->s_name));
195 			if (m->s_field && m->s_name == unnamed)
196 				continue;
197 			if (strcmp(m->s_name, namedmem->n_name) == 0) {
198 				istk->i_subt = m->s_type;
199 				istk->i_cnt++;
200 				memberpop();
201 				return;
202 			}
203 		}
204 		error(101, namedmem->n_name);
205 		DPRINTF(("%s(): namedmem %s\n", __func__, namedmem->n_name));
206 		memberpop();
207 		istk->i_namedmem = 1;
208 		return;
209 	}
210 	/*
211 	 * If the removed element was a structure member, we must go
212 	 * to the next structure member.
213 	 */
214 	if (istk->i_cnt > 0 && istk->i_type->t_tspec == STRUCT &&
215 	    !istk->i_namedmem) {
216 		do {
217 			m = istk->i_mem = istk->i_mem->s_nxt;
218 			if (m == NULL)
219 				LERROR("popi2()");
220 			DPRINTF(("%s(): pop %s\n", __func__, m->s_name));
221 		} while (m->s_field && m->s_name == unnamed);
222 		istk->i_subt = m->s_type;
223 	}
224 }
225 
226 static void
227 popinit(int brace)
228 {
229 	DPRINTF(("%s(%d)\n", __func__, brace));
230 
231 	if (brace) {
232 		/*
233 		 * Take all entries, including the first which requires
234 		 * a closing brace, from the stack.
235 		 */
236 		DPRINTF(("%s: brace\n", __func__));
237 		do {
238 			brace = initstk->i_brace;
239 			DPRINTF(("%s: loop brace %d\n", __func__, brace));
240 			popi2();
241 		} while (!brace);
242 		DPRINTF(("%s: brace done\n", __func__));
243 	} else {
244 		/*
245 		 * Take all entries which cannot be used for further
246 		 * initializers from the stack, but do this only if
247 		 * they do not require a closing brace.
248 		 */
249 		DPRINTF(("%s: no brace\n", __func__));
250 		while (!initstk->i_brace &&
251 		       initstk->i_cnt == 0 && !initstk->i_nolimit) {
252 			popi2();
253 		}
254 		DPRINTF(("%s: no brace done\n", __func__));
255 	}
256 }
257 
258 static void
259 pushinit(void)
260 {
261 #ifdef DEBUG
262 	char	buf[64];
263 #endif
264 	istk_t	*istk, *inxt;
265 	int	cnt;
266 	sym_t	*m;
267 
268 	istk = initstk;
269 
270 	/* Extend an incomplete array type by one element */
271 	if (istk->i_cnt == 0) {
272 		DPRINTF(("%s(extend) %s\n", __func__, tyname(buf, sizeof(buf),
273 		    istk->i_type)));
274 		/*
275 		 * Inside of other aggregate types must not be an incomplete
276 		 * type.
277 		 */
278 		if (istk->i_nxt->i_nxt != NULL)
279 			LERROR("pushinit()");
280 		istk->i_cnt = 1;
281 		if (istk->i_type->t_tspec != ARRAY)
282 			LERROR("pushinit()");
283 		istk->i_type->t_dim++;
284 		/* from now its an complete type */
285 		setcompl(istk->i_type, 0);
286 	}
287 
288 	if (istk->i_cnt <= 0)
289 		LERROR("pushinit()");
290 	if (istk->i_type != NULL && issclt(istk->i_type->t_tspec))
291 		LERROR("pushinit()");
292 
293 	initstk = xcalloc(1, sizeof (istk_t));
294 	initstk->i_nxt = istk;
295 	initstk->i_type = istk->i_subt;
296 	if (initstk->i_type->t_tspec == FUNC)
297 		LERROR("pushinit()");
298 
299 again:
300 	istk = initstk;
301 
302 	DPRINTF(("%s(%s)\n", __func__, tyname(buf, sizeof(buf), istk->i_type)));
303 	switch (istk->i_type->t_tspec) {
304 	case ARRAY:
305 		if (namedmem) {
306 			DPRINTF(("%s: ARRAY %s brace=%d\n", __func__,
307 			    namedmem->n_name, istk->i_brace));
308 			goto pop;
309 		} else if (istk->i_nxt->i_namedmem) {
310 			istk->i_brace = 1;
311 			DPRINTF(("%s ARRAY brace=%d, namedmem=%d\n", __func__,
312 			    istk->i_brace, istk->i_nxt->i_namedmem));
313 		}
314 
315 		if (incompl(istk->i_type) && istk->i_nxt->i_nxt != NULL) {
316 			/* initialisation of an incomplete type */
317 			error(175);
318 			initerr = 1;
319 			return;
320 		}
321 		istk->i_subt = istk->i_type->t_subt;
322 		istk->i_nolimit = incompl(istk->i_type);
323 		istk->i_cnt = istk->i_type->t_dim;
324 		DPRINTF(("%s: elements array %s[%d] %s\n", __func__,
325 		    tyname(buf, sizeof(buf), istk->i_subt), istk->i_cnt,
326 		    namedmem ? namedmem->n_name : "*none*"));
327 		break;
328 	case UNION:
329 		if (tflag)
330 			/* initialisation of union is illegal in trad. C */
331 			warning(238);
332 		/* FALLTHROUGH */
333 	case STRUCT:
334 		if (incompl(istk->i_type)) {
335 			/* initialisation of an incomplete type */
336 			error(175);
337 			initerr = 1;
338 			return;
339 		}
340 		cnt = 0;
341 		DPRINTF(("%s: 2. member lookup %s %s i_namedmem=%d\n", __func__,
342 		    tyname(buf, sizeof(buf), istk->i_type),
343 		    namedmem ? namedmem->n_name : "*none*", istk->i_namedmem));
344 		for (m = istk->i_type->t_str->memb; m != NULL; m = m->s_nxt) {
345 			if (m->s_field && m->s_name == unnamed)
346 				continue;
347 			if (namedmem != NULL) {
348 				DPRINTF(("%s():[member:%s, looking:%s]\n",
349 				    __func__, m->s_name, namedmem->n_name));
350 				if (strcmp(m->s_name, namedmem->n_name) == 0) {
351 					cnt++;
352 					break;
353 				} else
354 					continue;
355 			}
356 			if (++cnt == 1) {
357 				istk->i_mem = m;
358 				istk->i_subt = m->s_type;
359 			}
360 		}
361 		if (namedmem != NULL) {
362 			if (m == NULL) {
363 				DPRINTF(("%s(): struct pop\n", __func__));
364 				goto pop;
365 			}
366 			istk->i_mem = m;
367 			istk->i_subt = m->s_type;
368 			istk->i_namedmem = 1;
369 			DPRINTF(("%s(): namedmem %s\n", __func__,
370 			    namedmem->n_name));
371 			memberpop();
372 			cnt = istk->i_type->t_tspec == STRUCT ? 2 : 1;
373 		}
374 		istk->i_brace = 1;
375 		DPRINTF(("%s(): %s brace=%d\n", __func__,
376 		    tyname(buf, sizeof(buf),
377 		    istk->i_type ? istk->i_type : istk->i_subt),
378 		    istk->i_brace));
379 		if (cnt == 0) {
380 			/* cannot init. struct/union with no named member */
381 			error(179);
382 			initerr = 1;
383 			return;
384 		}
385 		istk->i_cnt = istk->i_type->t_tspec == STRUCT ? cnt : 1;
386 		break;
387 	default:
388 		if (namedmem) {
389 			DPRINTF(("%s(): pop\n", __func__));
390 	pop:
391 			inxt = initstk->i_nxt;
392 			free(istk);
393 			initstk = inxt;
394 			goto again;
395 		}
396 		istk->i_cnt = 1;
397 		break;
398 	}
399 }
400 
401 static void
402 testinit(void)
403 {
404 	istk_t	*istk;
405 
406 	istk = initstk;
407 
408 	/*
409 	 * If a closing brace is expected we have at least one initializer
410 	 * too much.
411 	 */
412 	if (istk->i_cnt == 0 && !istk->i_nolimit && !istk->i_namedmem) {
413 		switch (istk->i_type->t_tspec) {
414 		case ARRAY:
415 			/* too many array initializers */
416 			error(173, istk->i_type->t_dim);
417 			break;
418 		case STRUCT:
419 		case UNION:
420 			/* too many struct/union initializers */
421 			error(172);
422 			break;
423 		default:
424 			/* too many initializers */
425 			error(174);
426 			break;
427 		}
428 		initerr = 1;
429 	}
430 }
431 
432 static void
433 nextinit(int brace)
434 {
435 	char buf[64];
436 
437 	DPRINTF(("%s(%d)\n", __func__, brace));
438 	if (!brace) {
439 		if (initstk->i_type == NULL &&
440 		    !issclt(initstk->i_subt->t_tspec)) {
441 			/* {}-enclosed initializer required */
442 			error(181);
443 		}
444 		/*
445 		 * Make sure an entry with a scalar type is at the top
446 		 * of the stack.
447 		 */
448 		if (!initerr)
449 			testinit();
450 		while (!initerr && (initstk->i_type == NULL ||
451 				    !issclt(initstk->i_type->t_tspec))) {
452 			if (!initerr)
453 				pushinit();
454 		}
455 	} else {
456 		if (initstk->i_type != NULL &&
457 		    issclt(initstk->i_type->t_tspec)) {
458 			/* invalid initializer */
459 			error(176, tyname(buf, sizeof(buf), initstk->i_type));
460 			initerr = 1;
461 		}
462 		if (!initerr)
463 			testinit();
464 		if (!initerr)
465 			pushinit();
466 		if (!initerr) {
467 			initstk->i_brace = 1;
468 			DPRINTF(("%s(): %p %s brace=%d\n", __func__,
469 			    namedmem, tyname(buf, sizeof(buf),
470 			    initstk->i_type ? initstk->i_type :
471 			    initstk->i_subt), initstk->i_brace));
472 		}
473 	}
474 }
475 
476 void
477 initlbr(void)
478 {
479 	DPRINTF(("%s\n", __func__));
480 
481 	if (initerr)
482 		return;
483 
484 	if ((initsym->s_scl == AUTO || initsym->s_scl == REG) &&
485 	    initstk->i_nxt == NULL) {
486 		if (tflag && !issclt(initstk->i_subt->t_tspec))
487 			/* no automatic aggregate initialization in trad. C*/
488 			warning(188);
489 	}
490 
491 	/*
492 	 * Remove all entries which cannot be used for further initializers
493 	 * and do not expect a closing brace.
494 	 */
495 	popinit(0);
496 
497 	nextinit(1);
498 }
499 
500 void
501 initrbr(void)
502 {
503 	DPRINTF(("%s\n", __func__));
504 
505 	if (initerr)
506 		return;
507 
508 	popinit(1);
509 }
510 
511 void
512 mkinit(tnode_t *tn)
513 {
514 	ptrdiff_t offs;
515 	sym_t	*sym;
516 	tspec_t	lt, rt;
517 	tnode_t	*ln;
518 	struct	mbl *tmem;
519 	scl_t	sc;
520 #ifdef DEBUG
521 	char	buf[64], sbuf[64];
522 #endif
523 
524 	DPRINTF(("%s(%s %s)\n", __func__, tyname(buf, sizeof(buf), tn->tn_type),
525 	    prtnode(sbuf, sizeof(sbuf), tn)));
526 	if (initerr || tn == NULL)
527 		return;
528 
529 	sc = initsym->s_scl;
530 
531 	/*
532 	 * Do not test for automatic aggregate initialisation. If the
533 	 * initializer starts with a brace we have the warning already.
534 	 * If not, an error will be printed that the initializer must
535 	 * be enclosed by braces.
536 	 */
537 
538 	/*
539 	 * Local initialisation of non-array-types with only one expression
540 	 * without braces is done by ASSIGN
541 	 */
542 	if ((sc == AUTO || sc == REG) &&
543 	    initsym->s_type->t_tspec != ARRAY && initstk->i_nxt == NULL) {
544 		ln = getnnode(initsym, 0);
545 		ln->tn_type = tduptyp(ln->tn_type);
546 		ln->tn_type->t_const = 0;
547 		tn = build(ASSIGN, ln, tn);
548 		expr(tn, 0, 0, 0);
549 		return;
550 	}
551 
552 	/*
553 	 * Remove all entries which cannot be used for further initializers
554 	 * and do not require a closing brace.
555 	 */
556 	popinit(0);
557 
558 	/* Initialisations by strings are done in strginit(). */
559 	if (strginit(tn))
560 		return;
561 
562 	nextinit(0);
563 	if (initerr || tn == NULL)
564 		return;
565 
566 	initstk->i_cnt--;
567 	DPRINTF(("%s() cnt=%d tn=%p\n", __func__, initstk->i_cnt, tn));
568 	/* Create a temporary node for the left side. */
569 	ln = tgetblk(sizeof (tnode_t));
570 	ln->tn_op = NAME;
571 	ln->tn_type = tduptyp(initstk->i_type);
572 	ln->tn_type->t_const = 0;
573 	ln->tn_lvalue = 1;
574 	ln->tn_sym = initsym;		/* better than nothing */
575 
576 	tn = cconv(tn);
577 
578 	lt = ln->tn_type->t_tspec;
579 	rt = tn->tn_type->t_tspec;
580 
581 	if (!issclt(lt))
582 		LERROR("mkinit()");
583 
584 	if (!typeok(INIT, 0, ln, tn))
585 		return;
586 
587 	/*
588 	 * Store the tree memory. This is nessesary because otherwise
589 	 * expr() would free it.
590 	 */
591 	tmem = tsave();
592 	expr(tn, 1, 0, 1);
593 	trestor(tmem);
594 
595 	if (isityp(lt) && ln->tn_type->t_isfield && !isityp(rt)) {
596 		/*
597 		 * Bit-fields can be initialized in trad. C only by integer
598 		 * constants.
599 		 */
600 		if (tflag)
601 			/* bit-field initialisation is illegal in trad. C */
602 			warning(186);
603 	}
604 
605 	if (lt != rt || (initstk->i_type->t_isfield && tn->tn_op == CON))
606 		tn = convert(INIT, 0, initstk->i_type, tn);
607 
608 	if (tn != NULL && tn->tn_op != CON) {
609 		sym = NULL;
610 		offs = 0;
611 		if (conaddr(tn, &sym, &offs) == -1) {
612 			if (sc == AUTO || sc == REG) {
613 				/* non-constant initializer */
614 				(void)c99ism(177);
615 			} else {
616 				/* non-constant initializer */
617 				error(177);
618 			}
619 		}
620 	}
621 }
622 
623 
624 static int
625 strginit(tnode_t *tn)
626 {
627 	tspec_t	t;
628 	istk_t	*istk;
629 	int	len;
630 	strg_t	*strg;
631 
632 	if (tn->tn_op != STRING)
633 		return (0);
634 
635 	istk = initstk;
636 	strg = tn->tn_strg;
637 
638 	/*
639 	 * Check if we have an array type which can be initialized by
640 	 * the string.
641 	 */
642 	if (istk->i_subt != NULL && istk->i_subt->t_tspec == ARRAY) {
643 		DPRINTF(("%s: subt array\n", __func__));
644 		t = istk->i_subt->t_subt->t_tspec;
645 		if (!((strg->st_tspec == CHAR &&
646 		       (t == CHAR || t == UCHAR || t == SCHAR)) ||
647 		      (strg->st_tspec == WCHAR && t == WCHAR))) {
648 			return (0);
649 		}
650 		/* Put the array at top of stack */
651 		pushinit();
652 		istk = initstk;
653 	} else if (istk->i_type != NULL && istk->i_type->t_tspec == ARRAY) {
654 		DPRINTF(("%s: type array\n", __func__));
655 		t = istk->i_type->t_subt->t_tspec;
656 		if (!((strg->st_tspec == CHAR &&
657 		       (t == CHAR || t == UCHAR || t == SCHAR)) ||
658 		      (strg->st_tspec == WCHAR && t == WCHAR))) {
659 			return (0);
660 		}
661 		/*
662 		 * If the array is already partly initialized, we are
663 		 * wrong here.
664 		 */
665 		if (istk->i_cnt != istk->i_type->t_dim)
666 			return (0);
667 	} else {
668 		return (0);
669 	}
670 
671 	/* Get length without trailing NUL character. */
672 	len = strg->st_len;
673 
674 	if (istk->i_nolimit) {
675 		istk->i_nolimit = 0;
676 		istk->i_type->t_dim = len + 1;
677 		/* from now complete type */
678 		setcompl(istk->i_type, 0);
679 	} else {
680 		if (istk->i_type->t_dim < len) {
681 			/* non-null byte ignored in string initializer */
682 			warning(187);
683 		}
684 	}
685 
686 	/* In every case the array is initialized completely. */
687 	istk->i_cnt = 0;
688 
689 	return (1);
690 }
691