1 /* $OpenBSD: gnum4.c,v 1.52 2017/08/21 21:41:13 deraadt Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-2-Clause
5 *
6 * Copyright (c) 1999 Marc Espie
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 /*
33 * functions needed to support gnu-m4 extensions, including a fake freezing
34 */
35
36 #include <sys/types.h>
37 #include <sys/wait.h>
38 #include <ctype.h>
39 #include <err.h>
40 #include <paths.h>
41 #include <regex.h>
42 #include <stdarg.h>
43 #include <stddef.h>
44 #include <stdlib.h>
45 #include <stdint.h>
46 #include <stdio.h>
47 #include <string.h>
48 #include <errno.h>
49 #include <unistd.h>
50 #include <limits.h>
51 #include "mdef.h"
52 #include "stdd.h"
53 #include "extern.h"
54
55
56 int mimic_gnu = 0;
57
58 /*
59 * Support for include path search
60 * First search in the current directory.
61 * If not found, and the path is not absolute, include path kicks in.
62 * First, -I options, in the order found on the command line.
63 * Then M4PATH env variable
64 */
65
66 static struct path_entry {
67 char *name;
68 struct path_entry *next;
69 } *first, *last;
70
71 static struct path_entry *new_path_entry(const char *);
72 static void ensure_m4path(void);
73 static struct input_file *dopath(struct input_file *, const char *);
74
75 static struct path_entry *
new_path_entry(const char * dirname)76 new_path_entry(const char *dirname)
77 {
78 struct path_entry *n;
79
80 n = malloc(sizeof(struct path_entry));
81 if (!n)
82 errx(1, "out of memory");
83 n->name = xstrdup(dirname);
84 n->next = 0;
85 return n;
86 }
87
88 void
addtoincludepath(const char * dirname)89 addtoincludepath(const char *dirname)
90 {
91 struct path_entry *n;
92
93 n = new_path_entry(dirname);
94
95 if (last) {
96 last->next = n;
97 last = n;
98 }
99 else
100 last = first = n;
101 }
102
103 static void
ensure_m4path(void)104 ensure_m4path(void)
105 {
106 static int envpathdone = 0;
107 char *envpath;
108 char *sweep;
109 char *path;
110
111 if (envpathdone)
112 return;
113 envpathdone = TRUE;
114 envpath = getenv("M4PATH");
115 if (!envpath)
116 return;
117 /* for portability: getenv result is read-only */
118 envpath = xstrdup(envpath);
119 for (sweep = envpath;
120 (path = strsep(&sweep, ":")) != NULL;)
121 addtoincludepath(path);
122 free(envpath);
123 }
124
125 static
126 struct input_file *
dopath(struct input_file * i,const char * filename)127 dopath(struct input_file *i, const char *filename)
128 {
129 char path[PATH_MAX];
130 struct path_entry *pe;
131 FILE *f;
132
133 for (pe = first; pe; pe = pe->next) {
134 snprintf(path, sizeof(path), "%s/%s", pe->name, filename);
135 if ((f = fopen(path, "r")) != NULL) {
136 set_input(i, f, path);
137 return i;
138 }
139 }
140 return NULL;
141 }
142
143 struct input_file *
fopen_trypath(struct input_file * i,const char * filename)144 fopen_trypath(struct input_file *i, const char *filename)
145 {
146 FILE *f;
147
148 f = fopen(filename, "r");
149 if (f != NULL) {
150 set_input(i, f, filename);
151 return i;
152 }
153 if (filename[0] == '/')
154 return NULL;
155
156 ensure_m4path();
157
158 return dopath(i, filename);
159 }
160
161 void
doindir(const char * argv[],int argc)162 doindir(const char *argv[], int argc)
163 {
164 ndptr n;
165 struct macro_definition *p = NULL;
166
167 n = lookup(argv[2]);
168 if (n == NULL || (p = macro_getdef(n)) == NULL)
169 m4errx(1, "indir: undefined macro %s.", argv[2]);
170 argv[1] = p->defn;
171
172 eval(argv+1, argc-1, p->type, is_traced(n));
173 }
174
175 void
dobuiltin(const char * argv[],int argc)176 dobuiltin(const char *argv[], int argc)
177 {
178 ndptr p;
179
180 argv[1] = NULL;
181 p = macro_getbuiltin(argv[2]);
182 if (p != NULL)
183 eval(argv+1, argc-1, macro_builtin_type(p), is_traced(p));
184 else
185 m4errx(1, "unknown builtin %s.", argv[2]);
186 }
187
188
189 /* We need some temporary buffer space, as pb pushes BACK and substitution
190 * proceeds forward... */
191 static char *buffer;
192 static size_t bufsize = 0;
193 static size_t current = 0;
194
195 static void addchars(const char *, size_t);
196 static void addchar(int);
197 static char *twiddle(const char *);
198 static char *getstring(void);
199 static void exit_regerror(int, regex_t *, const char *);
200 static void do_subst(const char *, regex_t *, const char *, const char *,
201 regmatch_t *);
202 static void do_regexpindex(const char *, regex_t *, const char *, regmatch_t *);
203 static void do_regexp(const char *, regex_t *, const char *, const char *,
204 regmatch_t *);
205 static void add_sub(int, const char *, regex_t *, regmatch_t *);
206 static void add_replace(const char *, regex_t *, const char *, regmatch_t *);
207 #define addconstantstring(s) addchars((s), sizeof(s)-1)
208
209 static void
addchars(const char * c,size_t n)210 addchars(const char *c, size_t n)
211 {
212 if (n == 0)
213 return;
214 while (current + n > bufsize) {
215 if (bufsize == 0)
216 bufsize = 1024;
217 else if (bufsize <= SIZE_MAX/2) {
218 bufsize *= 2;
219 } else {
220 errx(1, "size overflow");
221 }
222 buffer = xrealloc(buffer, bufsize, NULL);
223 }
224 memcpy(buffer+current, c, n);
225 current += n;
226 }
227
228 static void
addchar(int c)229 addchar(int c)
230 {
231 if (current +1 > bufsize) {
232 if (bufsize == 0)
233 bufsize = 1024;
234 else
235 bufsize *= 2;
236 buffer = xrealloc(buffer, bufsize, NULL);
237 }
238 buffer[current++] = c;
239 }
240
241 static char *
getstring(void)242 getstring(void)
243 {
244 addchar('\0');
245 current = 0;
246 return buffer;
247 }
248
249
250 static void
exit_regerror(int er,regex_t * re,const char * source)251 exit_regerror(int er, regex_t *re, const char *source)
252 {
253 size_t errlen;
254 char *errbuf;
255
256 errlen = regerror(er, re, NULL, 0);
257 errbuf = xalloc(errlen,
258 "malloc in regerror: %lu", (unsigned long)errlen);
259 regerror(er, re, errbuf, errlen);
260 m4errx(1, "regular expression error in %s: %s.", source, errbuf);
261 }
262
263 /* warnx() plus check to see if we need to change exit code or exit .
264 * -E flag functionality.
265 */
266 void
m4_warnx(const char * fmt,...)267 m4_warnx(const char *fmt, ...)
268 {
269 va_list ap;
270
271 va_start(ap, fmt);
272 warnx(fmt, ap);
273 va_end(ap);
274
275 if (fatal_warns)
276 exit(1);
277 if (error_warns)
278 exit_code = 1;
279 }
280
281 static void
add_sub(int n,const char * string,regex_t * re,regmatch_t * pm)282 add_sub(int n, const char *string, regex_t *re, regmatch_t *pm)
283 {
284 if (n > (int)re->re_nsub)
285 m4_warnx("No subexpression %d", n);
286 /* Subexpressions that did not match are
287 * not an error. */
288 else if (pm[n].rm_so != -1 &&
289 pm[n].rm_eo != -1) {
290 addchars(string + pm[n].rm_so,
291 pm[n].rm_eo - pm[n].rm_so);
292 }
293 }
294
295 /* Add replacement string to the output buffer, recognizing special
296 * constructs and replacing them with substrings of the original string.
297 */
298 static void
add_replace(const char * string,regex_t * re,const char * replace,regmatch_t * pm)299 add_replace(const char *string, regex_t *re, const char *replace, regmatch_t *pm)
300 {
301 const char *p;
302
303 for (p = replace; *p != '\0'; p++) {
304 if (*p == '&' && !mimic_gnu) {
305 add_sub(0, string, re, pm);
306 continue;
307 }
308 if (*p == '\\') {
309 if (p[1] == '\\') {
310 addchar(p[1]);
311 p++;
312 continue;
313 }
314 if (p[1] == '&') {
315 if (mimic_gnu)
316 add_sub(0, string, re, pm);
317 else
318 addchar(p[1]);
319 p++;
320 continue;
321 }
322 if (isdigit((unsigned char)p[1])) {
323 add_sub(*(++p) - '0', string, re, pm);
324 continue;
325 }
326 }
327 addchar(*p);
328 }
329 }
330
331 static void
do_subst(const char * string,regex_t * re,const char * source,const char * replace,regmatch_t * pm)332 do_subst(const char *string, regex_t *re, const char *source,
333 const char *replace, regmatch_t *pm)
334 {
335 int error;
336 int flags = 0;
337 const char *last_match = NULL;
338
339 while ((error = regexec(re, string, re->re_nsub+1, pm, flags)) == 0) {
340 if (pm[0].rm_eo != 0) {
341 if (string[pm[0].rm_eo-1] == '\n')
342 flags = 0;
343 else
344 flags = REG_NOTBOL;
345 }
346
347 /* NULL length matches are special... We use the `vi-mode'
348 * rule: don't allow a NULL-match at the last match
349 * position.
350 */
351 if (pm[0].rm_so == pm[0].rm_eo &&
352 string + pm[0].rm_so == last_match) {
353 if (*string == '\0')
354 return;
355 addchar(*string);
356 if (*string++ == '\n')
357 flags = 0;
358 else
359 flags = REG_NOTBOL;
360 continue;
361 }
362 last_match = string + pm[0].rm_so;
363 addchars(string, pm[0].rm_so);
364 add_replace(string, re, replace, pm);
365 string += pm[0].rm_eo;
366 }
367 if (error != REG_NOMATCH)
368 exit_regerror(error, re, source);
369 pbstr(string);
370 }
371
372 static void
do_regexp(const char * string,regex_t * re,const char * source,const char * replace,regmatch_t * pm)373 do_regexp(const char *string, regex_t *re, const char *source,
374 const char *replace, regmatch_t *pm)
375 {
376 int error;
377
378 switch(error = regexec(re, string, re->re_nsub+1, pm, 0)) {
379 case 0:
380 add_replace(string, re, replace, pm);
381 pbstr(getstring());
382 break;
383 case REG_NOMATCH:
384 break;
385 default:
386 exit_regerror(error, re, source);
387 }
388 }
389
390 static void
do_regexpindex(const char * string,regex_t * re,const char * source,regmatch_t * pm)391 do_regexpindex(const char *string, regex_t *re, const char *source,
392 regmatch_t *pm)
393 {
394 int error;
395
396 switch(error = regexec(re, string, re->re_nsub+1, pm, 0)) {
397 case 0:
398 pbunsigned(pm[0].rm_so);
399 break;
400 case REG_NOMATCH:
401 pbnum(-1);
402 break;
403 default:
404 exit_regerror(error, re, source);
405 }
406 }
407
408 /* In Gnu m4 mode, parentheses for backmatch don't work like POSIX 1003.2
409 * says. So we twiddle with the regexp before passing it to regcomp.
410 */
411 static char *
twiddle(const char * p)412 twiddle(const char *p)
413 {
414 /* + at start of regexp is a normal character for Gnu m4 */
415 if (*p == '^') {
416 addchar(*p);
417 p++;
418 }
419 if (*p == '+') {
420 addchar('\\');
421 }
422 /* This could use strcspn for speed... */
423 while (*p != '\0') {
424 if (*p == '\\') {
425 switch(p[1]) {
426 case '(':
427 case ')':
428 case '|':
429 addchar(p[1]);
430 break;
431 case 'w':
432 addconstantstring("[_a-zA-Z0-9]");
433 break;
434 case 'W':
435 addconstantstring("[^_a-zA-Z0-9]");
436 break;
437 case '<':
438 addconstantstring("[[:<:]]");
439 break;
440 case '>':
441 addconstantstring("[[:>:]]");
442 break;
443 default:
444 addchars(p, 2);
445 break;
446 }
447 p+=2;
448 continue;
449 }
450 if (*p == '(' || *p == ')' || *p == '|')
451 addchar('\\');
452
453 addchar(*p);
454 p++;
455 }
456 return getstring();
457 }
458
459 /* patsubst(string, regexp, opt replacement) */
460 /* argv[2]: string
461 * argv[3]: regexp
462 * argv[4]: opt rep
463 */
464 void
dopatsubst(const char * argv[],int argc)465 dopatsubst(const char *argv[], int argc)
466 {
467 if (argc <= 3) {
468 m4_warnx("Too few arguments to patsubst");
469 return;
470 }
471 /* special case: empty regexp */
472 if (argv[3][0] == '\0') {
473 const char *s;
474 size_t len;
475 if (argc > 4 && argv[4])
476 len = strlen(argv[4]);
477 else
478 len = 0;
479 for (s = argv[2]; *s != '\0'; s++) {
480 addchars(argv[4], len);
481 addchar(*s);
482 }
483 } else {
484 int error;
485 regex_t re;
486 regmatch_t *pmatch;
487 int mode = REG_EXTENDED;
488 const char *source;
489 size_t l = strlen(argv[3]);
490
491 if (!mimic_gnu ||
492 (argv[3][0] == '^') ||
493 (l > 0 && argv[3][l-1] == '$'))
494 mode |= REG_NEWLINE;
495
496 source = mimic_gnu ? twiddle(argv[3]) : argv[3];
497 error = regcomp(&re, source, mode);
498 if (error != 0)
499 exit_regerror(error, &re, source);
500
501 pmatch = xreallocarray(NULL, re.re_nsub+1, sizeof(regmatch_t),
502 NULL);
503 do_subst(argv[2], &re, source,
504 argc > 4 && argv[4] != NULL ? argv[4] : "", pmatch);
505 free(pmatch);
506 regfree(&re);
507 }
508 pbstr(getstring());
509 }
510
511 void
doregexp(const char * argv[],int argc)512 doregexp(const char *argv[], int argc)
513 {
514 int error;
515 regex_t re;
516 regmatch_t *pmatch;
517 const char *source;
518
519 if (argc <= 3) {
520 m4_warnx("Too few arguments to regexp");
521 return;
522 }
523 /* special gnu case */
524 if (argv[3][0] == '\0' && mimic_gnu) {
525 if (argc == 4 || argv[4] == NULL)
526 return;
527 else
528 pbstr(argv[4]);
529 }
530 source = mimic_gnu ? twiddle(argv[3]) : argv[3];
531 error = regcomp(&re, source, REG_EXTENDED|REG_NEWLINE);
532 if (error != 0)
533 exit_regerror(error, &re, source);
534
535 pmatch = xreallocarray(NULL, re.re_nsub+1, sizeof(regmatch_t), NULL);
536 if (argc == 4 || argv[4] == NULL)
537 do_regexpindex(argv[2], &re, source, pmatch);
538 else
539 do_regexp(argv[2], &re, source, argv[4], pmatch);
540 free(pmatch);
541 regfree(&re);
542 }
543
544 void
doformat(const char * argv[],int argc)545 doformat(const char *argv[], int argc)
546 {
547 const char *format = argv[2];
548 int pos = 3;
549 int left_padded;
550 long width;
551 size_t l;
552 const char *thisarg = NULL;
553 char temp[2];
554 long extra;
555
556 while (*format != 0) {
557 if (*format != '%') {
558 addchar(*format++);
559 continue;
560 }
561
562 format++;
563 if (*format == '%') {
564 addchar(*format++);
565 continue;
566 }
567 if (*format == 0) {
568 addchar('%');
569 break;
570 }
571
572 if (*format == '*') {
573 format++;
574 if (pos >= argc)
575 m4errx(1,
576 "Format with too many format specifiers.");
577 width = strtol(argv[pos++], NULL, 10);
578 } else {
579 width = strtol(format, __DECONST(char **,&format), 10);
580 }
581 if (width < 0) {
582 left_padded = 1;
583 width = -width;
584 } else {
585 left_padded = 0;
586 }
587 if (*format == '.') {
588 format++;
589 if (*format == '*') {
590 format++;
591 if (pos >= argc)
592 m4errx(1,
593 "Format with too many format specifiers.");
594 extra = strtol(argv[pos++], NULL, 10);
595 } else {
596 extra = strtol(format, __DECONST(char **, &format), 10);
597 }
598 } else {
599 extra = LONG_MAX;
600 }
601 if (pos >= argc)
602 m4errx(1, "Format with too many format specifiers.");
603 switch(*format) {
604 case 's':
605 thisarg = argv[pos++];
606 break;
607 case 'c':
608 temp[0] = strtoul(argv[pos++], NULL, 10);
609 temp[1] = 0;
610 thisarg = temp;
611 break;
612 default:
613 m4errx(1, "Unsupported format specification: %s.",
614 argv[2]);
615 }
616 format++;
617 l = strlen(thisarg);
618 if ((long)l > extra)
619 l = extra;
620 if (!left_padded) {
621 while ((long)l < width--)
622 addchar(' ');
623 }
624 addchars(thisarg, l);
625 if (left_padded) {
626 while ((long)l < width--)
627 addchar(' ');
628 }
629 }
630 pbstr(getstring());
631 }
632
633 void
doesyscmd(const char * cmd)634 doesyscmd(const char *cmd)
635 {
636 int p[2];
637 pid_t cpid;
638 char *argv[4];
639 int cc;
640 int status;
641
642 /* Follow gnu m4 documentation: first flush buffers. */
643 fflush(NULL);
644
645 argv[0] = __DECONST(char *, "sh");
646 argv[1] = __DECONST(char *, "-c");
647 argv[2] = __DECONST(char *, cmd);
648 argv[3] = NULL;
649
650 /* Just set up standard output, share stderr and stdin with m4 */
651 if (pipe(p) == -1)
652 err(1, "bad pipe");
653 switch(cpid = fork()) {
654 case -1:
655 err(1, "bad fork");
656 /* NOTREACHED */
657 case 0:
658 (void) close(p[0]);
659 (void) dup2(p[1], 1);
660 (void) close(p[1]);
661 execv(_PATH_BSHELL, argv);
662 exit(1);
663 default:
664 /* Read result in two stages, since m4's buffer is
665 * pushback-only. */
666 (void) close(p[1]);
667 do {
668 char result[BUFSIZE];
669 cc = read(p[0], result, sizeof result);
670 if (cc > 0)
671 addchars(result, cc);
672 } while (cc > 0 || (cc == -1 && errno == EINTR));
673
674 (void) close(p[0]);
675 while (waitpid(cpid, &status, 0) == -1) {
676 if (errno != EINTR)
677 break;
678 }
679 pbstr(getstring());
680 }
681 }
682
683 void
getdivfile(const char * name)684 getdivfile(const char *name)
685 {
686 FILE *f;
687 int c;
688
689 f = fopen(name, "r");
690 if (!f)
691 return;
692
693 while ((c = getc(f))!= EOF)
694 putc(c, active);
695 (void) fclose(f);
696 }
697