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gnum4.c revision 1.5 
      1 /*	$NetBSD: gnum4.c,v 1.5 2004/10/30 20:39:35 dsl Exp $	*/
      2 /* $OpenBSD: gnum4.c,v 1.15 2001/10/13 20:18:48 espie Exp $ */
      3 
      4 /*
      5  * Copyright (c) 1999 Marc Espie
      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  *
     16  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #if HAVE_NBTOOL_CONFIG_H
     30 #include "nbtool_config.h"
     31 #endif
     32 
     33 /*
     34  * functions needed to support gnu-m4 extensions, including a fake freezing
     35  */
     36 
     37 #include <sys/param.h>
     38 #include <sys/types.h>
     39 #include <sys/wait.h>
     40 #include <ctype.h>
     41 #include <errno.h>
     42 #include <paths.h>
     43 #include <regex.h>
     44 #include <stddef.h>
     45 #include <stdlib.h>
     46 #include <stdio.h>
     47 #include <string.h>
     48 #include "mdef.h"
     49 #include "stdd.h"
     50 #include "extern.h"
     51 
     52 
     53 int mimic_gnu = 0;
     54 
     55 /*
     56  * Support for include path search
     57  * First search in the current directory.
     58  * If not found, and the path is not absolute, include path kicks in.
     59  * First, -I options, in the order found on the command line.
     60  * Then M4PATH env variable
     61  */
     62 
     63 struct path_entry {
     64 	char *name;
     65 	struct path_entry *next;
     66 } *first, *last;
     67 
     68 static struct path_entry *new_path_entry __P((const char *));
     69 static void ensure_m4path __P((void));
     70 static struct input_file *dopath __P((struct input_file *, const char *));
     71 
     72 static struct path_entry *
     73 new_path_entry(dirname)
     74 	const char *dirname;
     75 {
     76 	struct path_entry *n;
     77 
     78 	n = malloc(sizeof(struct path_entry));
     79 	if (!n)
     80 		errx(1, "out of memory");
     81 	n->name = strdup(dirname);
     82 	if (!n->name)
     83 		errx(1, "out of memory");
     84 	n->next = 0;
     85 	return n;
     86 }
     87 
     88 void
     89 addtoincludepath(dirname)
     90 	const char *dirname;
     91 {
     92 	struct path_entry *n;
     93 
     94 	n = new_path_entry(dirname);
     95 
     96 	if (last) {
     97 		last->next = n;
     98 		last = n;
     99 	}
    100 	else
    101 		last = first = n;
    102 }
    103 
    104 static void
    105 ensure_m4path()
    106 {
    107 	static int envpathdone = 0;
    108 	char *envpath;
    109 	char *sweep;
    110 	char *path;
    111 
    112 	if (envpathdone)
    113 		return;
    114 	envpathdone = TRUE;
    115 	envpath = getenv("M4PATH");
    116 	if (!envpath)
    117 		return;
    118 	/* for portability: getenv result is read-only */
    119 	envpath = strdup(envpath);
    120 	if (!envpath)
    121 		errx(1, "out of memory");
    122 	for (sweep = envpath;
    123 	    (path = strsep(&sweep, ":")) != NULL;)
    124 	    addtoincludepath(path);
    125 	free(envpath);
    126 }
    127 
    128 static
    129 struct input_file *
    130 dopath(i, filename)
    131 	struct input_file *i;
    132 	const char *filename;
    133 {
    134 	char path[MAXPATHLEN];
    135 	struct path_entry *pe;
    136 	FILE *f;
    137 
    138 	for (pe = first; pe; pe = pe->next) {
    139 		snprintf(path, sizeof(path), "%s/%s", pe->name, filename);
    140 		if ((f = fopen(path, "r")) != 0) {
    141 			set_input(i, f, path);
    142 			return i;
    143 		}
    144 	}
    145 	return NULL;
    146 }
    147 
    148 struct input_file *
    149 fopen_trypath(i, filename)
    150 	struct input_file *i;
    151 	const char *filename;
    152 {
    153 	FILE *f;
    154 
    155 	f = fopen(filename, "r");
    156 	if (f != NULL) {
    157 		set_input(i, f, filename);
    158 		return i;
    159 	}
    160 	if (filename[0] == '/')
    161 		return NULL;
    162 
    163 	ensure_m4path();
    164 
    165 	return dopath(i, filename);
    166 }
    167 
    168 void
    169 doindir(argv, argc)
    170 	const char *argv[];
    171 	int argc;
    172 {
    173 	ndptr p;
    174 
    175 	p = lookup(argv[2]);
    176 	if (p == NULL)
    177 		errx(1, "undefined macro %s", argv[2]);
    178 	argv[1] = p->defn;
    179 	eval(argv+1, argc-1, p->type);
    180 }
    181 
    182 void
    183 dobuiltin(argv, argc)
    184 	const char *argv[];
    185 	int argc;
    186 {
    187 	int n;
    188 	argv[1] = NULL;
    189 	n = builtin_type(argv[2]);
    190 	if (n != -1)
    191 		eval(argv+1, argc-1, n);
    192 	else
    193 		errx(1, "unknown builtin %s", argv[2]);
    194 }
    195 
    196 
    197 /* We need some temporary buffer space, as pb pushes BACK and substitution
    198  * proceeds forward... */
    199 static char *buffer;
    200 static size_t bufsize = 0;
    201 static size_t current = 0;
    202 
    203 static void addchars __P((const char *, size_t));
    204 static void addchar __P((char));
    205 static char *twiddle __P((const char *));
    206 static char *getstring __P((void));
    207 static void exit_regerror __P((int, regex_t *));
    208 static void do_subst __P((const char *, regex_t *, const char *, regmatch_t *));
    209 static void do_regexpindex __P((const char *, regex_t *, regmatch_t *));
    210 static void do_regexp __P((const char *, regex_t *, const char *, regmatch_t *));
    211 static void add_sub __P((int, const char *, regex_t *, regmatch_t *));
    212 static void add_replace __P((const char *, regex_t *, const char *, regmatch_t *));
    213 #define addconstantstring(s) addchars((s), sizeof(s)-1)
    214 
    215 static void
    216 addchars(c, n)
    217 	const char *c;
    218 	size_t n;
    219 {
    220 	if (n == 0)
    221 		return;
    222 	while (current + n > bufsize) {
    223 		if (bufsize == 0)
    224 			bufsize = 1024;
    225 		else
    226 			bufsize *= 2;
    227 		buffer = realloc(buffer, bufsize);
    228 		if (buffer == NULL)
    229 			errx(1, "out of memory");
    230 	}
    231 	memcpy(buffer+current, c, n);
    232 	current += n;
    233 }
    234 
    235 static void
    236 addchar(c)
    237 	char c;
    238 {
    239 	if (current +1 > bufsize) {
    240 		if (bufsize == 0)
    241 			bufsize = 1024;
    242 		else
    243 			bufsize *= 2;
    244 		buffer = realloc(buffer, bufsize);
    245 		if (buffer == NULL)
    246 			errx(1, "out of memory");
    247 	}
    248 	buffer[current++] = c;
    249 }
    250 
    251 static char *
    252 getstring()
    253 {
    254 	addchar('\0');
    255 	current = 0;
    256 	return buffer;
    257 }
    258 
    259 
    260 static void
    261 exit_regerror(er, re)
    262 	int er;
    263 	regex_t *re;
    264 {
    265 	size_t 	errlen;
    266 	char 	*errbuf;
    267 
    268 	errlen = regerror(er, re, NULL, 0);
    269 	errbuf = xalloc(errlen);
    270 	regerror(er, re, errbuf, errlen);
    271 	errx(1, "regular expression error: %s", errbuf);
    272 }
    273 
    274 static void
    275 add_sub(n, string, re, pm)
    276 	int n;
    277 	const char *string;
    278 	regex_t *re;
    279 	regmatch_t *pm;
    280 {
    281 	if (n > re->re_nsub)
    282 		warnx("No subexpression %d", n);
    283 	/* Subexpressions that did not match are
    284 	 * not an error.  */
    285 	else if (pm[n].rm_so != -1 &&
    286 	    pm[n].rm_eo != -1) {
    287 		addchars(string + pm[n].rm_so,
    288 			pm[n].rm_eo - pm[n].rm_so);
    289 	}
    290 }
    291 
    292 /* Add replacement string to the output buffer, recognizing special
    293  * constructs and replacing them with substrings of the original string.
    294  */
    295 static void
    296 add_replace(string, re, replace, pm)
    297 	const char *string;
    298 	regex_t *re;
    299 	const char *replace;
    300 	regmatch_t *pm;
    301 {
    302 	const char *p;
    303 
    304 	for (p = replace; *p != '\0'; p++) {
    305 		if (*p == '&' && !mimic_gnu) {
    306 			add_sub(0, string, re, pm);
    307 			continue;
    308 		}
    309 		if (*p == '\\') {
    310 			if (p[1] == '\\') {
    311 				addchar(p[1]);
    312 				p++;
    313 				continue;
    314 			}
    315 			if (p[1] == '&') {
    316 				if (mimic_gnu)
    317 					add_sub(0, string, re, pm);
    318 				else
    319 					addchar(p[1]);
    320 				p++;
    321 				continue;
    322 			}
    323 			if (isdigit((unsigned char)p[1])) {
    324 				add_sub(*(++p) - '0', string, re, pm);
    325 				continue;
    326 			}
    327 		}
    328 	    	addchar(*p);
    329 	}
    330 }
    331 
    332 static void
    333 do_subst(string, re, replace, pm)
    334 	const char *string;
    335 	regex_t *re;
    336 	const char *replace;
    337 	regmatch_t *pm;
    338 {
    339 	int error;
    340 	int flags = 0;
    341 	const char *last_match = NULL;
    342 
    343 	while ((error = regexec(re, string, re->re_nsub+1, pm, flags)) == 0) {
    344 		if (pm[0].rm_eo != 0) {
    345 			if (string[pm[0].rm_eo-1] == '\n')
    346 				flags = 0;
    347 			else
    348 				flags = REG_NOTBOL;
    349 		}
    350 
    351 		/* NULL length matches are special... We use the `vi-mode'
    352 		 * rule: don't allow a NULL-match at the last match
    353 		 * position.
    354 		 */
    355 		if (pm[0].rm_so == pm[0].rm_eo &&
    356 		    string + pm[0].rm_so == last_match) {
    357 			if (*string == '\0')
    358 				return;
    359 			addchar(*string);
    360 			if (*string++ == '\n')
    361 				flags = 0;
    362 			else
    363 				flags = REG_NOTBOL;
    364 			continue;
    365 		}
    366 		last_match = string + pm[0].rm_so;
    367 		addchars(string, pm[0].rm_so);
    368 		add_replace(string, re, replace, pm);
    369 		string += pm[0].rm_eo;
    370 	}
    371 	if (error != REG_NOMATCH)
    372 		exit_regerror(error, re);
    373 	pbstr(string);
    374 }
    375 
    376 static void
    377 do_regexp(string, re, replace, pm)
    378 	const char *string;
    379 	regex_t *re;
    380 	const char *replace;
    381 	regmatch_t *pm;
    382 {
    383 	int error;
    384 
    385 	switch(error = regexec(re, string, re->re_nsub+1, pm, 0)) {
    386 	case 0:
    387 		add_replace(string, re, replace, pm);
    388 		pbstr(getstring());
    389 		break;
    390 	case REG_NOMATCH:
    391 		break;
    392 	default:
    393 		exit_regerror(error, re);
    394 	}
    395 }
    396 
    397 static void
    398 do_regexpindex(string, re, pm)
    399 	const char *string;
    400 	regex_t *re;
    401 	regmatch_t *pm;
    402 {
    403 	int error;
    404 
    405 	switch(error = regexec(re, string, re->re_nsub+1, pm, 0)) {
    406 	case 0:
    407 		pbunsigned(pm[0].rm_so);
    408 		break;
    409 	case REG_NOMATCH:
    410 		pbnum(-1);
    411 		break;
    412 	default:
    413 		exit_regerror(error, re);
    414 	}
    415 }
    416 
    417 /* In Gnu m4 mode, parentheses for backmatch don't work like POSIX 1003.2
    418  * says. So we twiddle with the regexp before passing it to regcomp.
    419  */
    420 static char *
    421 twiddle(p)
    422 	const char *p;
    423 {
    424 	/* This could use strcspn for speed... */
    425 	while (*p != '\0') {
    426 		if (*p == '\\') {
    427 			switch(p[1]) {
    428 			case '(':
    429 			case ')':
    430 			case '|':
    431 				addchar(p[1]);
    432 				break;
    433 			case 'w':
    434 				addconstantstring("[_a-zA-Z0-9]");
    435 				break;
    436 			case 'W':
    437 				addconstantstring("[^_a-zA-Z0-9]");
    438 				break;
    439 			case '<':
    440 				addconstantstring("[[:<:]]");
    441 				break;
    442 			case '>':
    443 				addconstantstring("[[:>:]]");
    444 				break;
    445 			default:
    446 				addchars(p, 2);
    447 				break;
    448 			}
    449 			p+=2;
    450 			continue;
    451 		}
    452 		if (*p == '(' || *p == ')' || *p == '|')
    453 			addchar('\\');
    454 
    455 		addchar(*p);
    456 		p++;
    457 	}
    458 	return getstring();
    459 }
    460 
    461 /* patsubst(string, regexp, opt replacement) */
    462 /* argv[2]: string
    463  * argv[3]: regexp
    464  * argv[4]: opt rep
    465  */
    466 void
    467 dopatsubst(argv, argc)
    468 	const char *argv[];
    469 	int argc;
    470 {
    471 	int error;
    472 	regex_t re;
    473 	regmatch_t *pmatch;
    474 
    475 	if (argc <= 3) {
    476 		warnx("Too few arguments to patsubst");
    477 		return;
    478 	}
    479 	error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3],
    480 	    REG_NEWLINE | REG_EXTENDED);
    481 	if (error != 0)
    482 		exit_regerror(error, &re);
    483 
    484 	pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub+1));
    485 	do_subst(argv[2], &re,
    486 	    argc != 4 && argv[4] != NULL ? argv[4] : "", pmatch);
    487 	pbstr(getstring());
    488 	free(pmatch);
    489 	regfree(&re);
    490 }
    491 
    492 void
    493 doregexp(argv, argc)
    494 	const char *argv[];
    495 	int argc;
    496 {
    497 	int error;
    498 	regex_t re;
    499 	regmatch_t *pmatch;
    500 
    501 	if (argc <= 3) {
    502 		warnx("Too few arguments to regexp");
    503 		return;
    504 	}
    505 	error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3],
    506 	    REG_EXTENDED);
    507 	if (error != 0)
    508 		exit_regerror(error, &re);
    509 
    510 	pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub+1));
    511 	if (argv[4] == NULL || argc == 4)
    512 		do_regexpindex(argv[2], &re, pmatch);
    513 	else
    514 		do_regexp(argv[2], &re, argv[4], pmatch);
    515 	free(pmatch);
    516 	regfree(&re);
    517 }
    518 
    519 void
    520 doesyscmd(cmd)
    521 	const char *cmd;
    522 {
    523 	int p[2];
    524 	pid_t pid, cpid;
    525 	char *argv[4];
    526 	int cc;
    527 	int status;
    528 
    529 	/* Follow gnu m4 documentation: first flush buffers. */
    530 	fflush(NULL);
    531 
    532 	argv[0] = "sh";
    533 	argv[1] = "-c";
    534 	argv[2] = (char *)cmd;
    535 	argv[3] = NULL;
    536 
    537 	/* Just set up standard output, share stderr and stdin with m4 */
    538 	if (pipe(p) == -1)
    539 		err(1, "bad pipe");
    540 	switch(cpid = fork()) {
    541 	case -1:
    542 		err(1, "bad fork");
    543 		/* NOTREACHED */
    544 	case 0:
    545 		(void) close(p[0]);
    546 		(void) dup2(p[1], 1);
    547 		(void) close(p[1]);
    548 		execv(_PATH_BSHELL, argv);
    549 		exit(1);
    550 	default:
    551 		/* Read result in two stages, since m4's buffer is
    552 		 * pushback-only. */
    553 		(void) close(p[1]);
    554 		do {
    555 			char result[BUFSIZE];
    556 			cc = read(p[0], result, sizeof result);
    557 			if (cc > 0)
    558 				addchars(result, cc);
    559 		} while (cc > 0 || (cc == -1 && errno == EINTR));
    560 
    561 		(void) close(p[0]);
    562 		while ((pid = wait(&status)) != cpid && pid >= 0)
    563 			continue;
    564 		pbstr(getstring());
    565 	}
    566 }
    567