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init.c revision 1.9 
      1 /*	$NetBSD: init.c,v 1.9 2001/09/18 18:15:54 wiz 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 #ifndef lint
     36 __RCSID("$NetBSD: init.c,v 1.9 2001/09/18 18:15:54 wiz Exp $");
     37 #endif
     38 
     39 #include <stdlib.h>
     40 
     41 #include "lint1.h"
     42 
     43 /*
     44  * initerr is set as soon as a fatal error occurred in an initialisation.
     45  * The effect is that the rest of the initialisation is ignored (parsed
     46  * by yacc, expression trees built, but no initialisation takes place).
     47  */
     48 int	initerr;
     49 
     50 /* Pointer to the symbol which is to be initialized. */
     51 sym_t	*initsym;
     52 
     53 /* Points to the top element of the initialisation stack. */
     54 istk_t	*initstk;
     55 
     56 
     57 static	void	popi2(void);
     58 static	void	popinit(int);
     59 static	void	pushinit(void);
     60 static	void	testinit(void);
     61 static	void	nextinit(int);
     62 static	int	strginit(tnode_t *);
     63 
     64 
     65 /*
     66  * Initialize the initialisation stack by putting an entry for the variable
     67  * which is to be initialized on it.
     68  */
     69 void
     70 prepinit(void)
     71 {
     72 	istk_t	*istk;
     73 
     74 	if (initerr)
     75 		return;
     76 
     77 	/* free memory used in last initialisation */
     78 	while ((istk = initstk) != NULL) {
     79 		initstk = istk->i_nxt;
     80 		free(istk);
     81 	}
     82 
     83 	/*
     84 	 * If the type which is to be initialized is an incomplete type,
     85 	 * it must be duplicated.
     86 	 */
     87 	if (initsym->s_type->t_tspec == ARRAY && incompl(initsym->s_type))
     88 		initsym->s_type = duptyp(initsym->s_type);
     89 
     90 	istk = initstk = xcalloc(1, sizeof (istk_t));
     91 	istk->i_subt = initsym->s_type;
     92 	istk->i_cnt = 1;
     93 
     94 }
     95 
     96 static void
     97 popi2(void)
     98 {
     99 	istk_t	*istk;
    100 	sym_t	*m;
    101 
    102 	initstk = (istk = initstk)->i_nxt;
    103 	if (initstk == NULL)
    104 		lerror("popi2() 1");
    105 	free(istk);
    106 
    107 	istk = initstk;
    108 
    109 	istk->i_cnt--;
    110 	if (istk->i_cnt < 0)
    111 		lerror("popi2() 3");
    112 
    113 	/*
    114 	 * If the removed element was a structure member, we must go
    115 	 * to the next structure member.
    116 	 */
    117 	if (istk->i_cnt > 0 && istk->i_type->t_tspec == STRUCT) {
    118 		do {
    119 			m = istk->i_mem = istk->i_mem->s_nxt;
    120 			if (m == NULL)
    121 				lerror("popi2() 2");
    122 		} while (m->s_field && m->s_name == unnamed);
    123 		istk->i_subt = m->s_type;
    124 	}
    125 }
    126 
    127 static void
    128 popinit(int brace)
    129 {
    130 
    131 	if (brace) {
    132 		/*
    133 		 * Take all entries, including the first which requires
    134 		 * a closing brace, from the stack.
    135 		 */
    136 		do {
    137 			brace = initstk->i_brace;
    138 			popi2();
    139 		} while (!brace);
    140 	} else {
    141 		/*
    142 		 * Take all entries which cannot be used for further
    143 		 * initializers from the stack, but do this only if
    144 		 * they do not require a closing brace.
    145 		 */
    146 		while (!initstk->i_brace &&
    147 		       initstk->i_cnt == 0 && !initstk->i_nolimit) {
    148 			popi2();
    149 		}
    150 	}
    151 }
    152 
    153 static void
    154 pushinit(void)
    155 {
    156 	istk_t	*istk;
    157 	int	cnt;
    158 	sym_t	*m;
    159 
    160 	istk = initstk;
    161 
    162 	/* Extend an incomplete array type by one element */
    163 	if (istk->i_cnt == 0) {
    164 		/*
    165 		 * Inside of other aggregate types must not be an incomplete
    166 		 * type.
    167 		 */
    168 		if (istk->i_nxt->i_nxt != NULL)
    169 			lerror("pushinit() 1");
    170 		istk->i_cnt = 1;
    171 		if (istk->i_type->t_tspec != ARRAY)
    172 			lerror("pushinit() 2");
    173 		istk->i_type->t_dim++;
    174 		/* from now its an complete type */
    175 		setcompl(istk->i_type, 0);
    176 	}
    177 
    178 	if (istk->i_cnt <= 0)
    179 		lerror("pushinit() 3");
    180 	if (istk->i_type != NULL && issclt(istk->i_type->t_tspec))
    181 		lerror("pushinit() 4");
    182 
    183 	initstk = xcalloc(1, sizeof (istk_t));
    184 	initstk->i_nxt = istk;
    185 	initstk->i_type = istk->i_subt;
    186 	if (initstk->i_type->t_tspec == FUNC)
    187 		lerror("pushinit() 5");
    188 
    189 	istk = initstk;
    190 
    191 	switch (istk->i_type->t_tspec) {
    192 	case ARRAY:
    193 		if (incompl(istk->i_type) && istk->i_nxt->i_nxt != NULL) {
    194 			/* initialisation of an incomplete type */
    195 			error(175);
    196 			initerr = 1;
    197 			return;
    198 		}
    199 		istk->i_subt = istk->i_type->t_subt;
    200 		istk->i_nolimit = incompl(istk->i_type);
    201 		istk->i_cnt = istk->i_type->t_dim;
    202 		break;
    203 	case UNION:
    204 		if (tflag)
    205 			/* initialisation of union is illegal in trad. C */
    206 			warning(238);
    207 		/* FALLTHROUGH */
    208 	case STRUCT:
    209 		if (incompl(istk->i_type)) {
    210 			/* initialisation of an incomplete type */
    211 			error(175);
    212 			initerr = 1;
    213 			return;
    214 		}
    215 		cnt = 0;
    216 		for (m = istk->i_type->t_str->memb; m != NULL; m = m->s_nxt) {
    217 			if (m->s_field && m->s_name == unnamed)
    218 				continue;
    219 			if (++cnt == 1) {
    220 				istk->i_mem = m;
    221 				istk->i_subt = m->s_type;
    222 			}
    223 		}
    224 		if (cnt == 0) {
    225 			/* cannot init. struct/union with no named member */
    226 			error(179);
    227 			initerr = 1;
    228 			return;
    229 		}
    230 		istk->i_cnt = istk->i_type->t_tspec == STRUCT ? cnt : 1;
    231 		break;
    232 	default:
    233 		istk->i_cnt = 1;
    234 		break;
    235 	}
    236 }
    237 
    238 static void
    239 testinit(void)
    240 {
    241 	istk_t	*istk;
    242 
    243 	istk = initstk;
    244 
    245 	/*
    246 	 * If a closing brace is expected we have at least one initializer
    247 	 * too much.
    248 	 */
    249 	if (istk->i_cnt == 0 && !istk->i_nolimit) {
    250 		switch (istk->i_type->t_tspec) {
    251 		case ARRAY:
    252 			/* too many array initializers */
    253 			error(173);
    254 			break;
    255 		case STRUCT:
    256 		case UNION:
    257 			/* too many struct/union initializers */
    258 			error(172);
    259 			break;
    260 		default:
    261 			/* too many initializers */
    262 			error(174);
    263 			break;
    264 		}
    265 		initerr = 1;
    266 	}
    267 }
    268 
    269 static void
    270 nextinit(int brace)
    271 {
    272 
    273 	if (!brace) {
    274 		if (initstk->i_type == NULL &&
    275 		    !issclt(initstk->i_subt->t_tspec)) {
    276 			/* {}-enclosed initializer required */
    277 			error(181);
    278 		}
    279 		/*
    280 		 * Make sure an entry with a scalar type is at the top
    281 		 * of the stack.
    282 		 */
    283 		if (!initerr)
    284 			testinit();
    285 		while (!initerr && (initstk->i_type == NULL ||
    286 				    !issclt(initstk->i_type->t_tspec))) {
    287 			if (!initerr)
    288 				pushinit();
    289 		}
    290 	} else {
    291 		if (initstk->i_type != NULL &&
    292 		    issclt(initstk->i_type->t_tspec)) {
    293 			/* invalid initializer */
    294 			error(176);
    295 			initerr = 1;
    296 		}
    297 		if (!initerr)
    298 			testinit();
    299 		if (!initerr)
    300 			pushinit();
    301 		if (!initerr)
    302 			initstk->i_brace = 1;
    303 	}
    304 }
    305 
    306 void
    307 initlbr(void)
    308 {
    309 
    310 	if (initerr)
    311 		return;
    312 
    313 	if ((initsym->s_scl == AUTO || initsym->s_scl == REG) &&
    314 	    initstk->i_nxt == NULL) {
    315 		if (tflag && !issclt(initstk->i_subt->t_tspec))
    316 			/* no automatic aggregate initialization in trad. C*/
    317 			warning(188);
    318 	}
    319 
    320 	/*
    321 	 * Remove all entries which cannot be used for further initializers
    322 	 * and do not expect a closing brace.
    323 	 */
    324 	popinit(0);
    325 
    326 	nextinit(1);
    327 }
    328 
    329 void
    330 initrbr(void)
    331 {
    332 
    333 	if (initerr)
    334 		return;
    335 
    336 	popinit(1);
    337 }
    338 
    339 void
    340 mkinit(tnode_t *tn)
    341 {
    342 	ptrdiff_t offs;
    343 	sym_t	*sym;
    344 	tspec_t	lt, rt;
    345 	tnode_t	*ln;
    346 	struct	mbl *tmem;
    347 	scl_t	sc;
    348 
    349 	if (initerr || tn == NULL)
    350 		goto end;
    351 
    352 	sc = initsym->s_scl;
    353 
    354 	/*
    355 	 * Do not test for automatic aggregat initialisation. If the
    356 	 * initializer starts with a brace we have the warning already.
    357 	 * If not, an error will be printed that the initializer must
    358 	 * be enclosed by braces.
    359 	 */
    360 
    361 	/*
    362 	 * Local initialisation of non-array-types with only one expression
    363 	 * without braces is done by ASSIGN
    364 	 */
    365 	if ((sc == AUTO || sc == REG) &&
    366 	    initsym->s_type->t_tspec != ARRAY && initstk->i_nxt == NULL) {
    367 		ln = getnnode(initsym, 0);
    368 		ln->tn_type = tduptyp(ln->tn_type);
    369 		ln->tn_type->t_const = 0;
    370 		tn = build(ASSIGN, ln, tn);
    371 		expr(tn, 0, 0);
    372 		goto end;
    373 	}
    374 
    375 	/*
    376 	 * Remove all entries which cannot be used for further initializers
    377 	 * and do not require a closing brace.
    378 	 */
    379 	popinit(0);
    380 
    381 	/* Initialisations by strings are done in strginit(). */
    382 	if (strginit(tn))
    383 		goto end;
    384 
    385 	nextinit(0);
    386 	if (initerr || tn == NULL)
    387 		goto end;
    388 
    389 	initstk->i_cnt--;
    390 
    391 	/* Create a temporary node for the left side. */
    392 	ln = tgetblk(sizeof (tnode_t));
    393 	ln->tn_op = NAME;
    394 	ln->tn_type = tduptyp(initstk->i_type);
    395 	ln->tn_type->t_const = 0;
    396 	ln->tn_lvalue = 1;
    397 	ln->tn_sym = initsym;		/* better than nothing */
    398 
    399 	tn = cconv(tn);
    400 
    401 	lt = ln->tn_type->t_tspec;
    402 	rt = tn->tn_type->t_tspec;
    403 
    404 	if (!issclt(lt))
    405 		lerror("mkinit() 1");
    406 
    407 	if (!typeok(INIT, 0, ln, tn))
    408 		goto end;
    409 
    410 	/*
    411 	 * Store the tree memory. This is nessesary because otherwise
    412 	 * expr() would free it.
    413 	 */
    414 	tmem = tsave();
    415 	expr(tn, 1, 0);
    416 	trestor(tmem);
    417 
    418 	if (isityp(lt) && ln->tn_type->t_isfield && !isityp(rt)) {
    419 		/*
    420 		 * Bit-fields can be initialized in trad. C only by integer
    421 		 * constants.
    422 		 */
    423 		if (tflag)
    424 			/* bit-field initialisation is illegal in trad. C */
    425 			warning(186);
    426 	}
    427 
    428 	if (lt != rt || (initstk->i_type->t_isfield && tn->tn_op == CON))
    429 		tn = convert(INIT, 0, initstk->i_type, tn);
    430 
    431 	if (tn != NULL && tn->tn_op != CON) {
    432 		sym = NULL;
    433 		offs = 0;
    434 		if (conaddr(tn, &sym, &offs) == -1) {
    435 			if (sc == AUTO || sc == REG) {
    436 				/* non-constant initializer */
    437 				(void)gnuism(177);
    438 			} else {
    439 				/* non-constant initializer */
    440 				error(177);
    441 			}
    442 		}
    443 	}
    444 
    445  end:
    446 	tfreeblk();
    447 }
    448 
    449 
    450 static int
    451 strginit(tnode_t *tn)
    452 {
    453 	tspec_t	t;
    454 	istk_t	*istk;
    455 	int	len;
    456 	strg_t	*strg;
    457 
    458 	if (tn->tn_op != STRING)
    459 		return (0);
    460 
    461 	istk = initstk;
    462 	strg = tn->tn_strg;
    463 
    464 	/*
    465 	 * Check if we have an array type which can be initialized by
    466 	 * the string.
    467 	 */
    468 	if (istk->i_subt->t_tspec == ARRAY) {
    469 		t = istk->i_subt->t_subt->t_tspec;
    470 		if (!((strg->st_tspec == CHAR &&
    471 		       (t == CHAR || t == UCHAR || t == SCHAR)) ||
    472 		      (strg->st_tspec == WCHAR && t == WCHAR))) {
    473 			return (0);
    474 		}
    475 		/* Put the array at top of stack */
    476 		pushinit();
    477 		istk = initstk;
    478 	} else if (istk->i_type != NULL && istk->i_type->t_tspec == ARRAY) {
    479 		t = istk->i_type->t_subt->t_tspec;
    480 		if (!((strg->st_tspec == CHAR &&
    481 		       (t == CHAR || t == UCHAR || t == SCHAR)) ||
    482 		      (strg->st_tspec == WCHAR && t == WCHAR))) {
    483 			return (0);
    484 		}
    485 		/*
    486 		 * If the array is already partly initialized, we are
    487 		 * wrong here.
    488 		 */
    489 		if (istk->i_cnt != istk->i_type->t_dim)
    490 			return (0);
    491 	} else {
    492 		return (0);
    493 	}
    494 
    495 	/* Get length without trailing NUL character. */
    496 	len = strg->st_len;
    497 
    498 	if (istk->i_nolimit) {
    499 		istk->i_nolimit = 0;
    500 		istk->i_type->t_dim = len + 1;
    501 		/* from now complete type */
    502 		setcompl(istk->i_type, 0);
    503 	} else {
    504 		if (istk->i_type->t_dim < len) {
    505 			/* non-null byte ignored in string initializer */
    506 			warning(187);
    507 		}
    508 	}
    509 
    510 	/* In every case the array is initialized completely. */
    511 	istk->i_cnt = 0;
    512 
    513 	return (1);
    514 }
    515