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/usr.bin/m4/gnum4.c

https://bitbucket.org/freebsd/freebsd-head/
C | 665 lines | 535 code | 66 blank | 64 comment | 146 complexity | a1d419ead88836bfd21ea985bdca78b0 MD5 | raw file
  1/* $OpenBSD: gnum4.c,v 1.42 2011/11/06 12:25:43 espie Exp $ */
  2
  3/*
  4 * Copyright (c) 1999 Marc Espie
  5 *
  6 * Redistribution and use in source and binary forms, with or without
  7 * modification, are permitted provided that the following conditions
  8 * are met:
  9 * 1. Redistributions of source code must retain the above copyright
 10 *    notice, this list of conditions and the following disclaimer.
 11 * 2. Redistributions in binary form must reproduce the above copyright
 12 *    notice, this list of conditions and the following disclaimer in the
 13 *    documentation and/or other materials provided with the distribution.
 14 *
 15 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 25 * SUCH DAMAGE.
 26 */
 27#include <sys/cdefs.h>
 28__FBSDID("$FreeBSD$");
 29
 30/*
 31 * functions needed to support gnu-m4 extensions, including a fake freezing
 32 */
 33
 34#include <sys/param.h>
 35#include <sys/types.h>
 36#include <sys/wait.h>
 37#include <ctype.h>
 38#include <err.h>
 39#include <paths.h>
 40#include <regex.h>
 41#include <stddef.h>
 42#include <stdlib.h>
 43#include <stdio.h>
 44#include <string.h>
 45#include <errno.h>
 46#include <unistd.h>
 47#include "mdef.h"
 48#include "stdd.h"
 49#include "extern.h"
 50
 51
 52int mimic_gnu = 0;
 53
 54/*
 55 * Support for include path search
 56 * First search in the current directory.
 57 * If not found, and the path is not absolute, include path kicks in.
 58 * First, -I options, in the order found on the command line.
 59 * Then M4PATH env variable
 60 */
 61
 62struct path_entry {
 63	char *name;
 64	struct path_entry *next;
 65} *first, *last;
 66
 67static struct path_entry *new_path_entry(const char *);
 68static void ensure_m4path(void);
 69static struct input_file *dopath(struct input_file *, const char *);
 70
 71static struct path_entry *
 72new_path_entry(const char *dirname)
 73{
 74	struct path_entry *n;
 75
 76	n = malloc(sizeof(struct path_entry));
 77	if (!n)
 78		errx(1, "out of memory");
 79	n->name = strdup(dirname);
 80	if (!n->name)
 81		errx(1, "out of memory");
 82	n->next = 0;
 83	return n;
 84}
 85
 86void
 87addtoincludepath(const char *dirname)
 88{
 89	struct path_entry *n;
 90
 91	n = new_path_entry(dirname);
 92
 93	if (last) {
 94		last->next = n;
 95		last = n;
 96	}
 97	else
 98		last = first = n;
 99}
100
101static void
102ensure_m4path(void)
103{
104	static int envpathdone = 0;
105	char *envpath;
106	char *sweep;
107	char *path;
108
109	if (envpathdone)
110		return;
111	envpathdone = TRUE;
112	envpath = getenv("M4PATH");
113	if (!envpath)
114		return;
115	/* for portability: getenv result is read-only */
116	envpath = strdup(envpath);
117	if (!envpath)
118		errx(1, "out of memory");
119	for (sweep = envpath;
120	    (path = strsep(&sweep, ":")) != NULL;)
121	    addtoincludepath(path);
122	free(envpath);
123}
124
125static
126struct input_file *
127dopath(struct input_file *i, const char *filename)
128{
129	char path[MAXPATHLEN];
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")) != 0) {
136			set_input(i, f, path);
137			return i;
138		}
139	}
140	return NULL;
141}
142
143struct input_file *
144fopen_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
161void
162doindir(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
175void
176dobuiltin(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... */
191static char *buffer;
192static size_t bufsize = 0;
193static size_t current = 0;
194
195static void addchars(const char *, size_t);
196static void addchar(int);
197static char *twiddle(const char *);
198static char *getstring(void);
199static void exit_regerror(int, regex_t *);
200static void do_subst(const char *, regex_t *, const char *, regmatch_t *);
201static void do_regexpindex(const char *, regex_t *, regmatch_t *);
202static void do_regexp(const char *, regex_t *, const char *, regmatch_t *);
203static void add_sub(int, const char *, regex_t *, regmatch_t *);
204static void add_replace(const char *, regex_t *, const char *, regmatch_t *);
205#define addconstantstring(s) addchars((s), sizeof(s)-1)
206
207static void
208addchars(const char *c, size_t n)
209{
210	if (n == 0)
211		return;
212	while (current + n > bufsize) {
213		if (bufsize == 0)
214			bufsize = 1024;
215		else
216			bufsize *= 2;
217		buffer = xrealloc(buffer, bufsize, NULL);
218	}
219	memcpy(buffer+current, c, n);
220	current += n;
221}
222
223static void
224addchar(int c)
225{
226	if (current +1 > bufsize) {
227		if (bufsize == 0)
228			bufsize = 1024;
229		else
230			bufsize *= 2;
231		buffer = xrealloc(buffer, bufsize, NULL);
232	}
233	buffer[current++] = c;
234}
235
236static char *
237getstring(void)
238{
239	addchar('\0');
240	current = 0;
241	return buffer;
242}
243
244
245static void
246exit_regerror(int er, regex_t *re)
247{
248	size_t	errlen;
249	char	*errbuf;
250
251	errlen = regerror(er, re, NULL, 0);
252	errbuf = xalloc(errlen,
253	    "malloc in regerror: %lu", (unsigned long)errlen);
254	regerror(er, re, errbuf, errlen);
255	m4errx(1, "regular expression error: %s.", errbuf);
256}
257
258static void
259add_sub(int n, const char *string, regex_t *re, regmatch_t *pm)
260{
261	if (n > (int)re->re_nsub)
262		warnx("No subexpression %d", n);
263	/* Subexpressions that did not match are
264	 * not an error.  */
265	else if (pm[n].rm_so != -1 &&
266	    pm[n].rm_eo != -1) {
267		addchars(string + pm[n].rm_so,
268			pm[n].rm_eo - pm[n].rm_so);
269	}
270}
271
272/* Add replacement string to the output buffer, recognizing special
273 * constructs and replacing them with substrings of the original string.
274 */
275static void
276add_replace(const char *string, regex_t *re, const char *replace, regmatch_t *pm)
277{
278	const char *p;
279
280	for (p = replace; *p != '\0'; p++) {
281		if (*p == '&' && !mimic_gnu) {
282			add_sub(0, string, re, pm);
283			continue;
284		}
285		if (*p == '\\') {
286			if (p[1] == '\\') {
287				addchar(p[1]);
288				p++;
289				continue;
290			}
291			if (p[1] == '&') {
292				if (mimic_gnu)
293					add_sub(0, string, re, pm);
294				else
295					addchar(p[1]);
296				p++;
297				continue;
298			}
299			if (isdigit(p[1])) {
300				add_sub(*(++p) - '0', string, re, pm);
301				continue;
302			}
303		}
304		addchar(*p);
305	}
306}
307
308static void
309do_subst(const char *string, regex_t *re, const char *replace, regmatch_t *pm)
310{
311	int error;
312	int flags = 0;
313	const char *last_match = NULL;
314
315	while ((error = regexec(re, string, re->re_nsub+1, pm, flags)) == 0) {
316		if (pm[0].rm_eo != 0) {
317			if (string[pm[0].rm_eo-1] == '\n')
318				flags = 0;
319			else
320				flags = REG_NOTBOL;
321		}
322
323		/* NULL length matches are special... We use the `vi-mode'
324		 * rule: don't allow a NULL-match at the last match
325		 * position.
326		 */
327		if (pm[0].rm_so == pm[0].rm_eo &&
328		    string + pm[0].rm_so == last_match) {
329			if (*string == '\0')
330				return;
331			addchar(*string);
332			if (*string++ == '\n')
333				flags = 0;
334			else
335				flags = REG_NOTBOL;
336			continue;
337		}
338		last_match = string + pm[0].rm_so;
339		addchars(string, pm[0].rm_so);
340		add_replace(string, re, replace, pm);
341		string += pm[0].rm_eo;
342	}
343	if (error != REG_NOMATCH)
344		exit_regerror(error, re);
345	pbstr(string);
346}
347
348static void
349do_regexp(const char *string, regex_t *re, const char *replace, regmatch_t *pm)
350{
351	int error;
352
353	switch(error = regexec(re, string, re->re_nsub+1, pm, 0)) {
354	case 0:
355		add_replace(string, re, replace, pm);
356		pbstr(getstring());
357		break;
358	case REG_NOMATCH:
359		break;
360	default:
361		exit_regerror(error, re);
362	}
363}
364
365static void
366do_regexpindex(const char *string, regex_t *re, regmatch_t *pm)
367{
368	int error;
369
370	switch(error = regexec(re, string, re->re_nsub+1, pm, 0)) {
371	case 0:
372		pbunsigned(pm[0].rm_so);
373		break;
374	case REG_NOMATCH:
375		pbnum(-1);
376		break;
377	default:
378		exit_regerror(error, re);
379	}
380}
381
382/* In Gnu m4 mode, parentheses for backmatch don't work like POSIX 1003.2
383 * says. So we twiddle with the regexp before passing it to regcomp.
384 */
385static char *
386twiddle(const char *p)
387{
388	/* + at start of regexp is a normal character for Gnu m4 */
389	if (*p == '^') {
390		addchar(*p);
391		p++;
392	}
393	if (*p == '+') {
394		addchar('\\');
395	}
396	/* This could use strcspn for speed... */
397	while (*p != '\0') {
398		if (*p == '\\') {
399			switch(p[1]) {
400			case '(':
401			case ')':
402			case '|':
403				addchar(p[1]);
404				break;
405			case 'w':
406				addconstantstring("[_a-zA-Z0-9]");
407				break;
408			case 'W':
409				addconstantstring("[^_a-zA-Z0-9]");
410				break;
411			case '<':
412				addconstantstring("[[:<:]]");
413				break;
414			case '>':
415				addconstantstring("[[:>:]]");
416				break;
417			default:
418				addchars(p, 2);
419				break;
420			}
421			p+=2;
422			continue;
423		}
424		if (*p == '(' || *p == ')' || *p == '|')
425			addchar('\\');
426
427		addchar(*p);
428		p++;
429	}
430	return getstring();
431}
432
433/* patsubst(string, regexp, opt replacement) */
434/* argv[2]: string
435 * argv[3]: regexp
436 * argv[4]: opt rep
437 */
438void
439dopatsubst(const char *argv[], int argc)
440{
441	if (argc <= 3) {
442		warnx("Too few arguments to patsubst");
443		return;
444	}
445	/* special case: empty regexp */
446	if (argv[3][0] == '\0') {
447		const char *s;
448		size_t len;
449		if (argc > 4 && argv[4])
450			len = strlen(argv[4]);
451		else
452			len = 0;
453		for (s = argv[2]; *s != '\0'; s++) {
454			addchars(argv[4], len);
455			addchar(*s);
456		}
457	} else {
458		int error;
459		regex_t re;
460		regmatch_t *pmatch;
461		int mode = REG_EXTENDED;
462		size_t l = strlen(argv[3]);
463
464		if (!mimic_gnu ||
465		    (argv[3][0] == '^') ||
466		    (l > 0 && argv[3][l-1] == '$'))
467			mode |= REG_NEWLINE;
468
469		error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3],
470		    mode);
471		if (error != 0)
472			exit_regerror(error, &re);
473
474		pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub+1), NULL);
475		do_subst(argv[2], &re,
476		    argc > 4 && argv[4] != NULL ? argv[4] : "", pmatch);
477		free(pmatch);
478		regfree(&re);
479	}
480	pbstr(getstring());
481}
482
483void
484doregexp(const char *argv[], int argc)
485{
486	int error;
487	regex_t re;
488	regmatch_t *pmatch;
489
490	if (argc <= 3) {
491		warnx("Too few arguments to regexp");
492		return;
493	}
494	/* special gnu case */
495	if (argv[3][0] == '\0' && mimic_gnu) {
496		if (argc == 4 || argv[4] == NULL)
497			return;
498		else
499			pbstr(argv[4]);
500	}
501	error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3],
502	    REG_EXTENDED|REG_NEWLINE);
503	if (error != 0)
504		exit_regerror(error, &re);
505
506	pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub+1), NULL);
507	if (argc == 4 || argv[4] == NULL)
508		do_regexpindex(argv[2], &re, pmatch);
509	else
510		do_regexp(argv[2], &re, argv[4], pmatch);
511	free(pmatch);
512	regfree(&re);
513}
514
515void
516doformat(const char *argv[], int argc)
517{
518	const char *format = argv[2];
519	int pos = 3;
520	int left_padded;
521	long width;
522	size_t l;
523	const char *thisarg = NULL;
524	char temp[2];
525	long extra;
526
527	while (*format != 0) {
528		if (*format != '%') {
529			addchar(*format++);
530			continue;
531		}
532
533		format++;
534		if (*format == '%') {
535			addchar(*format++);
536			continue;
537		}
538		if (*format == 0) {
539			addchar('%');
540			break;
541		}
542
543		if (*format == '*') {
544			format++;
545			if (pos >= argc)
546				m4errx(1,
547				    "Format with too many format specifiers.");
548			width = strtol(argv[pos++], NULL, 10);
549		} else {
550			width = strtol(format, __DECONST(char **,&format), 10);
551		}
552		if (width < 0) {
553			left_padded = 1;
554			width = -width;
555		} else {
556			left_padded = 0;
557		}
558		if (*format == '.') {
559			format++;
560			if (*format == '*') {
561				format++;
562				if (pos >= argc)
563					m4errx(1,
564					    "Format with too many format specifiers.");
565				extra = strtol(argv[pos++], NULL, 10);
566			} else {
567				extra = strtol(format, __DECONST(char **, &format), 10);
568			}
569		} else {
570			extra = LONG_MAX;
571		}
572		if (pos >= argc)
573			m4errx(1, "Format with too many format specifiers.");
574		switch(*format) {
575		case 's':
576			thisarg = argv[pos++];
577			break;
578		case 'c':
579			temp[0] = strtoul(argv[pos++], NULL, 10);
580			temp[1] = 0;
581			thisarg = temp;
582			break;
583		default:
584			m4errx(1, "Unsupported format specification: %s.",
585			    argv[2]);
586		}
587		format++;
588		l = strlen(thisarg);
589		if ((long)l > extra)
590			l = extra;
591		if (!left_padded) {
592			while ((long)l < width--)
593				addchar(' ');
594		}
595		addchars(thisarg, l);
596		if (left_padded) {
597			while ((long)l < width--)
598				addchar(' ');
599		}
600	}
601	pbstr(getstring());
602}
603
604void
605doesyscmd(const char *cmd)
606{
607	int p[2];
608	pid_t pid, cpid;
609	char *argv[4];
610	int cc;
611	int status;
612
613	/* Follow gnu m4 documentation: first flush buffers. */
614	fflush(NULL);
615
616	argv[0] = __DECONST(char *, "sh");
617	argv[1] = __DECONST(char *, "-c");
618	argv[2] = __DECONST(char *, cmd);
619	argv[3] = NULL;
620
621	/* Just set up standard output, share stderr and stdin with m4 */
622	if (pipe(p) == -1)
623		err(1, "bad pipe");
624	switch(cpid = fork()) {
625	case -1:
626		err(1, "bad fork");
627		/* NOTREACHED */
628	case 0:
629		(void) close(p[0]);
630		(void) dup2(p[1], 1);
631		(void) close(p[1]);
632		execv(_PATH_BSHELL, argv);
633		exit(1);
634	default:
635		/* Read result in two stages, since m4's buffer is
636		 * pushback-only. */
637		(void) close(p[1]);
638		do {
639			char result[BUFSIZE];
640			cc = read(p[0], result, sizeof result);
641			if (cc > 0)
642				addchars(result, cc);
643		} while (cc > 0 || (cc == -1 && errno == EINTR));
644
645		(void) close(p[0]);
646		while ((pid = wait(&status)) != cpid && pid >= 0)
647			continue;
648		pbstr(getstring());
649	}
650}
651
652void
653getdivfile(const char *name)
654{
655	FILE *f;
656	int c;
657
658	f = fopen(name, "r");
659	if (!f)
660		return;
661
662	while ((c = getc(f))!= EOF)
663		putc(c, active);
664	(void) fclose(f);
665}