[dragonfly.git] / usr.bin / m4 / gnum4.c

/* $OpenBSD: gnum4.c,v 1.42 2011/11/06 12:25:43 espie Exp $ */

/*
 * Copyright (c) 1999 Marc Espie
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/usr.bin/m4/gnum4.c,v 1.15 2012/11/17 01:54:24 svnexp Exp $
 */

/*
 * functions needed to support gnu-m4 extensions, including a fake freezing
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <ctype.h>
#include <err.h>
#include <paths.h>
#include <regex.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "mdef.h"
#include "stdd.h"
#include "extern.h"


int mimic_gnu = 0;

/*
 * Support for include path search
 * First search in the current directory.
 * If not found, and the path is not absolute, include path kicks in.
 * First, -I options, in the order found on the command line.
 * Then M4PATH env variable
 */

static struct path_entry {
	char *name;
	struct path_entry *next;
} *first, *last;

static struct path_entry *new_path_entry(const char *);
static void ensure_m4path(void);
static struct input_file *dopath(struct input_file *, const char *);

static struct path_entry *
new_path_entry(const char *dirname)
{
	struct path_entry *n;

	n = malloc(sizeof(struct path_entry));
	if (n == NULL)
		errx(1, "out of memory");
	n->name = strdup(dirname);
	if (n->name == NULL)
		errx(1, "out of memory");
	n->next = NULL;
	return n;
}

void
addtoincludepath(const char *dirname)
{
	struct path_entry *n;

	n = new_path_entry(dirname);

	if (last) {
		last->next = n;
		last = n;
	} else {
		last = first = n;
	}
}

static void
ensure_m4path(void)
{
	static int envpathdone = 0;
	char *envpath;
	char *sweep;
	char *path;

	if (envpathdone)
		return;
	envpathdone = TRUE;
	envpath = getenv("M4PATH");
	if (!envpath)
		return;
	/* for portability: getenv result is read-only */
	envpath = strdup(envpath);
	if (envpath == NULL)
		errx(1, "out of memory");
	for (sweep = envpath;
	    (path = strsep(&sweep, ":")) != NULL;)
		addtoincludepath(path);
	free(envpath);
}

static struct input_file *
dopath(struct input_file *i, const char *filename)
{
	char path[MAXPATHLEN];
	struct path_entry *pe;
	FILE *f;

	for (pe = first; pe; pe = pe->next) {
		snprintf(path, sizeof(path), "%s/%s", pe->name, filename);
		if ((f = fopen(path, "r")) != NULL) {
			set_input(i, f, path);
			return i;
		}
	}
	return NULL;
}

struct input_file *
fopen_trypath(struct input_file *i, const char *filename)
{
	FILE *f;

	f = fopen(filename, "r");
	if (f != NULL) {
		set_input(i, f, filename);
		return i;
	}
	if (filename[0] == '/')
		return NULL;

	ensure_m4path();

	return dopath(i, filename);
}

void
doindir(const char *argv[], int argc)
{
	ndptr n;
	struct macro_definition *p = NULL;

	n = lookup(argv[2]);
	if (n == NULL || (p = macro_getdef(n)) == NULL)
		m4errx(1, "indir: undefined macro %s.", argv[2]);
	argv[1] = p->defn;

	eval(argv + 1, argc - 1, p->type, is_traced(n));
}

void
dobuiltin(const char *argv[], int argc)
{
	ndptr p;

	argv[1] = NULL;
	p = macro_getbuiltin(argv[2]);
	if (p != NULL)
		eval(argv + 1, argc - 1, macro_builtin_type(p), is_traced(p));
	else
		m4errx(1, "unknown builtin %s.", argv[2]);
}


/* We need some temporary buffer space, as pb pushes BACK and substitution
 * proceeds forward... */
static char *buffer;
static size_t bufsize = 0;
static size_t current = 0;

static void addchars(const char *, size_t);
static void addchar(int);
static char *twiddle(const char *);
static char *getstring(void);
static void exit_regerror(int, regex_t *);
static void do_subst(const char *, regex_t *, const char *, regmatch_t *);
static void do_regexpindex(const char *, regex_t *, regmatch_t *);
static void do_regexp(const char *, regex_t *, const char *, regmatch_t *);
static void add_sub(int, const char *, regex_t *, regmatch_t *);
static void add_replace(const char *, regex_t *, const char *, regmatch_t *);
#define	addconstantstring(s) addchars((s), sizeof(s)-1)

static void
addchars(const char *c, size_t n)
{
	if (n == 0)
		return;
	while (current + n > bufsize) {
		if (bufsize == 0)
			bufsize = 1024;
		else
			bufsize *= 2;
		buffer = xrealloc(buffer, bufsize, NULL);
	}
	memcpy(buffer + current, c, n);
	current += n;
}

static void
addchar(int c)
{
	if (current + 1 > bufsize) {
		if (bufsize == 0)
			bufsize = 1024;
		else
			bufsize *= 2;
		buffer = xrealloc(buffer, bufsize, NULL);
	}
	buffer[current++] = c;
}

static char *
getstring(void)
{
	addchar('\0');
	current = 0;
	return buffer;
}


static void
exit_regerror(int er, regex_t *re)
{
	size_t	errlen;
	char	*errbuf;

	errlen = regerror(er, re, NULL, 0);
	errbuf = xalloc(errlen,
	    "malloc in regerror: %lu", (unsigned long)errlen);
	regerror(er, re, errbuf, errlen);
	m4errx(1, "regular expression error: %s.", errbuf);
}

static void
add_sub(int n, const char *string, regex_t *re, regmatch_t *pm)
{
	if (n > (int)re->re_nsub)
		warnx("No subexpression %d", n);
	/* Subexpressions that did not match are
	 * not an error.  */
	else if (pm[n].rm_so != -1 && pm[n].rm_eo != -1)
		addchars(string + pm[n].rm_so, pm[n].rm_eo - pm[n].rm_so);
}

/* Add replacement string to the output buffer, recognizing special
 * constructs and replacing them with substrings of the original string.
 */
static void
add_replace(const char *string, regex_t *re, const char *replace, regmatch_t *pm)
{
	const char *p;

	for (p = replace; *p != '\0'; p++) {
		if (*p == '&' && !mimic_gnu) {
			add_sub(0, string, re, pm);
			continue;
		}
		if (*p == '\\') {
			if (p[1] == '\\') {
				addchar(p[1]);
				p++;
				continue;
			}
			if (p[1] == '&') {
				if (mimic_gnu)
					add_sub(0, string, re, pm);
				else
					addchar(p[1]);
				p++;
				continue;
			}
			if (isdigit(p[1])) {
				add_sub(*(++p) - '0', string, re, pm);
				continue;
			}
		}
		addchar(*p);
	}
}

static void
do_subst(const char *string, regex_t *re, const char *replace, regmatch_t *pm)
{
	int error;
	int flags = 0;
	const char *last_match = NULL;

	while ((error = regexec(re, string, re->re_nsub + 1, pm, flags)) == 0) {
		if (pm[0].rm_eo != 0) {
			if (string[pm[0].rm_eo - 1] == '\n')
				flags = 0;
			else
				flags = REG_NOTBOL;
		}

		/* NULL length matches are special... We use the `vi-mode'
		 * rule: don't allow a NULL-match at the last match
		 * position.
		 */
		if (pm[0].rm_so == pm[0].rm_eo &&
		    string + pm[0].rm_so == last_match) {
			if (*string == '\0')
				return;
			addchar(*string);
			if (*string++ == '\n')
				flags = 0;
			else
				flags = REG_NOTBOL;
			continue;
		}
		last_match = string + pm[0].rm_so;
		addchars(string, pm[0].rm_so);
		add_replace(string, re, replace, pm);
		string += pm[0].rm_eo;
	}
	if (error != REG_NOMATCH)
		exit_regerror(error, re);
	pbstr(string);
}

static void
do_regexp(const char *string, regex_t *re, const char *replace, regmatch_t *pm)
{
	int error;

	switch(error = regexec(re, string, re->re_nsub + 1, pm, 0)) {
	case 0:
		add_replace(string, re, replace, pm);
		pbstr(getstring());
		break;
	case REG_NOMATCH:
		break;
	default:
		exit_regerror(error, re);
	}
}

static void
do_regexpindex(const char *string, regex_t *re, regmatch_t *pm)
{
	int error;

	switch(error = regexec(re, string, re->re_nsub + 1, pm, 0)) {
	case 0:
		pbunsigned(pm[0].rm_so);
		break;
	case REG_NOMATCH:
		pbnum(-1);
		break;
	default:
		exit_regerror(error, re);
	}
}

/* In Gnu m4 mode, parentheses for backmatch don't work like POSIX 1003.2
 * says. So we twiddle with the regexp before passing it to regcomp.
 */
static char *
twiddle(const char *p)
{
	/* + at start of regexp is a normal character for Gnu m4 */
	if (*p == '^') {
		addchar(*p);
		p++;
	}
	if (*p == '+')
		addchar('\\');
	/* This could use strcspn for speed... */
	while (*p != '\0') {
		if (*p == '\\') {
			switch(p[1]) {
			case '(':
			case ')':
			case '|':
				addchar(p[1]);
				break;
			case 'w':
				addconstantstring("[_a-zA-Z0-9]");
				break;
			case 'W':
				addconstantstring("[^_a-zA-Z0-9]");
				break;
			case '<':
				addconstantstring("[[:<:]]");
				break;
			case '>':
				addconstantstring("[[:>:]]");
				break;
			default:
				addchars(p, 2);
				break;
			}
			p += 2;
			continue;
		}
		if (*p == '(' || *p == ')' || *p == '|')
			addchar('\\');

		addchar(*p);
		p++;
	}
	return getstring();
}

/* patsubst(string, regexp, opt replacement) */
/* argv[2]: string
 * argv[3]: regexp
 * argv[4]: opt rep
 */
void
dopatsubst(const char *argv[], int argc)
{
	if (argc <= 3) {
		warnx("Too few arguments to patsubst");
		return;
	}
	/* special case: empty regexp */
	if (argv[3][0] == '\0') {
		const char *s;
		size_t len;
		if (argc > 4 && argv[4])
			len = strlen(argv[4]);
		else
			len = 0;
		for (s = argv[2]; *s != '\0'; s++) {
			addchars(argv[4], len);
			addchar(*s);
		}
	} else {
		int error;
		regex_t re;
		regmatch_t *pmatch;
		int mode = REG_EXTENDED;
		size_t l = strlen(argv[3]);

		if (!mimic_gnu ||
		    (argv[3][0] == '^') ||
		    (l > 0 && argv[3][l-1] == '$'))
			mode |= REG_NEWLINE;

		error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3],
		    mode);
		if (error != 0)
			exit_regerror(error, &re);

		pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub + 1), NULL);
		do_subst(argv[2], &re,
		    argc > 4 && argv[4] != NULL ? argv[4] : "", pmatch);
		free(pmatch);
		regfree(&re);
	}
	pbstr(getstring());
}

void
doregexp(const char *argv[], int argc)
{
	int error;
	regex_t re;
	regmatch_t *pmatch;

	if (argc <= 3) {
		warnx("Too few arguments to regexp");
		return;
	}
	/* special gnu case */
	if (argv[3][0] == '\0' && mimic_gnu) {
		if (argc == 4 || argv[4] == NULL)
			return;
		else
			pbstr(argv[4]);
	}
	error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3],
	    REG_EXTENDED|REG_NEWLINE);
	if (error != 0)
		exit_regerror(error, &re);

	pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub + 1), NULL);
	if (argc == 4 || argv[4] == NULL)
		do_regexpindex(argv[2], &re, pmatch);
	else
		do_regexp(argv[2], &re, argv[4], pmatch);
	free(pmatch);
	regfree(&re);
}

void
doformat(const char *argv[], int argc)
{
	const char *format = argv[2];
	int pos = 3;
	int left_padded;
	long width;
	size_t l;
	const char *thisarg = NULL;
	char temp[2];
	long extra;

	while (*format != 0) {
		if (*format != '%') {
			addchar(*format++);
			continue;
		}

		format++;
		if (*format == '%') {
			addchar(*format++);
			continue;
		}
		if (*format == 0) {
			addchar('%');
			break;
		}

		if (*format == '*') {
			format++;
			if (pos >= argc)
				m4errx(1,
				    "Format with too many format specifiers.");
			width = strtol(argv[pos++], NULL, 10);
		} else {
			width = strtol(format, __DECONST(char **, &format), 10);
		}
		if (width < 0) {
			left_padded = 1;
			width = -width;
		} else {
			left_padded = 0;
		}
		if (*format == '.') {
			format++;
			if (*format == '*') {
				format++;
				if (pos >= argc)
					m4errx(1,
					    "Format with too many format specifiers.");
				extra = strtol(argv[pos++], NULL, 10);
			} else {
				extra = strtol(format, __DECONST(char **, &format), 10);
			}
		} else {
			extra = LONG_MAX;
		}
		if (pos >= argc)
			m4errx(1, "Format with too many format specifiers.");
		switch(*format) {
		case 's':
			thisarg = argv[pos++];
			break;
		case 'c':
			temp[0] = strtoul(argv[pos++], NULL, 10);
			temp[1] = 0;
			thisarg = temp;
			break;
		default:
			m4errx(1, "Unsupported format specification: %s.",
			    argv[2]);
		}
		format++;
		l = strlen(thisarg);
		if ((long)l > extra)
			l = extra;
		if (!left_padded) {
			while ((long)l < width--)
				addchar(' ');
		}
		addchars(thisarg, l);
		if (left_padded) {
			while ((long)l < width--)
				addchar(' ');
		}
	}
	pbstr(getstring());
}

void
doesyscmd(const char *cmd)
{
	int p[2];
	pid_t pid, cpid;
	char *argv[4];
	int cc;
	int status;

	/* Follow gnu m4 documentation: first flush buffers. */
	fflush(NULL);

	argv[0] = __DECONST(char *, "sh");
	argv[1] = __DECONST(char *, "-c");
	argv[2] = __DECONST(char *, cmd);
	argv[3] = NULL;

	/* Just set up standard output, share stderr and stdin with m4 */
	if (pipe(p) == -1)
		err(1, "bad pipe");
	switch(cpid = fork()) {
	case -1:
		err(1, "bad fork");
		/* NOTREACHED */
	case 0:
		close(p[0]);
		dup2(p[1], 1);
		close(p[1]);
		execv(_PATH_BSHELL, argv);
		exit(1);
	default:
		/* Read result in two stages, since m4's buffer is
		 * pushback-only. */
		close(p[1]);
		do {
			char result[BUFSIZE];
			cc = read(p[0], result, sizeof result);
			if (cc > 0)
				addchars(result, cc);
		} while (cc > 0 || (cc == -1 && errno == EINTR));

		close(p[0]);
		while ((pid = wait(&status)) != cpid && pid >= 0)
			continue;
		pbstr(getstring());
	}
}

void
getdivfile(const char *name)
{
	FILE *f;
	int c;

	f = fopen(name, "r");
	if (!f)
		return;

	while ((c = getc(f)) != EOF)
		putc(c, active);
	fclose(f);
}
Commit	Line	Data
4afad3d8	1	/* $OpenBSD: gnum4.c,v 1.42 2011/11/06 12:25:43 espie Exp $ */
984263bc MD	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.
1de703da	26	*
4afad3d8	27	* $FreeBSD: src/usr.bin/m4/gnum4.c,v 1.15 2012/11/17 01:54:24 svnexp Exp $
984263bc MD	28	*/
984263bc MD	29
4afad3d8	30	/*
984263bc MD	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>
4afad3d8	38	#include <err.h>
984263bc MD	39	#include <paths.h>
	40	#include <regex.h>
	41	#include <stddef.h>
	42	#include <stdlib.h>
	43	#include <stdio.h>
	44	#include <string.h>
984263bc MD	45	#include <errno.h>
	46	#include <unistd.h>
	47	#include "mdef.h"
	48	#include "stdd.h"
	49	#include "extern.h"
	50
	51
	52	int mimic_gnu = 0;
	53
	54	/*
	55	* Support for include path search
4afad3d8	56	* First search in the current directory.
984263bc MD	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
4afad3d8	62	static struct path_entry {
984263bc MD	63	char *name;
	64	struct path_entry *next;
	65	} first, last;
	66
	67	static struct path_entry new_path_entry(const char );
	68	static void ensure_m4path(void);
	69	static struct input_file dopath(struct input_file , const char *);
	70
	71	static struct path_entry *
	72	new_path_entry(const char *dirname)
	73	{
	74	struct path_entry *n;
	75
	76	n = malloc(sizeof(struct path_entry));
4afad3d8	77	if (n == NULL)
984263bc MD	78	errx(1, "out of memory");
984263bc MD	79	n->name = strdup(dirname);
4afad3d8	80	if (n->name == NULL)
984263bc	81	errx(1, "out of memory");
678e8cc6	82	n->next = NULL;
984263bc MD	83	return n;
984263bc MD	84	}
10c3f15b PA	85
10c3f15b PA	86	void
984263bc MD	87	addtoincludepath(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;
4afad3d8	96	} else {
984263bc	97	last = first = n;
4afad3d8	98	}
984263bc MD	99	}
	100
	101	static void
	102	ensure_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");
10c3f15b	113	if (!envpath)
984263bc MD	114	return;
	115	/* for portability: getenv result is read-only */
	116	envpath = strdup(envpath);
4afad3d8	117	if (envpath == NULL)
984263bc	118	errx(1, "out of memory");
10c3f15b	119	for (sweep = envpath;
984263bc	120	(path = strsep(&sweep, ":")) != NULL;)
4afad3d8	121	addtoincludepath(path);
984263bc MD	122	free(envpath);
	123	}
	124
4afad3d8	125	static struct input_file *
984263bc MD	126	dopath(struct input_file i, const char filename)
	127	{
	128	char path[MAXPATHLEN];
	129	struct path_entry *pe;
	130	FILE *f;
	131
	132	for (pe = first; pe; pe = pe->next) {
	133	snprintf(path, sizeof(path), "%s/%s", pe->name, filename);
678e8cc6	134	if ((f = fopen(path, "r")) != NULL) {
984263bc MD	135	set_input(i, f, path);
	136	return i;
	137	}
	138	}
	139	return NULL;
	140	}
	141
	142	struct input_file *
	143	fopen_trypath(struct input_file i, const char filename)
	144	{
	145	FILE *f;
	146
	147	f = fopen(filename, "r");
	148	if (f != NULL) {
	149	set_input(i, f, filename);
	150	return i;
	151	}
	152	if (filename[0] == '/')
	153	return NULL;
	154
	155	ensure_m4path();
	156
	157	return dopath(i, filename);
	158	}
	159
10c3f15b	160	void
984263bc MD	161	doindir(const char *argv[], int argc)
984263bc MD	162	{
4afad3d8 PA	163	ndptr n;
4afad3d8 PA	164	struct macro_definition *p = NULL;
984263bc	165
4afad3d8 PA	166	n = lookup(argv[2]);
	167	if (n == NULL \|\| (p = macro_getdef(n)) == NULL)
	168	m4errx(1, "indir: undefined macro %s.", argv[2]);
984263bc	169	argv[1] = p->defn;
4afad3d8 PA	170
4afad3d8 PA	171	eval(argv + 1, argc - 1, p->type, is_traced(n));
984263bc MD	172	}
984263bc MD	173
10c3f15b	174	void
984263bc MD	175	dobuiltin(const char *argv[], int argc)
984263bc MD	176	{
4afad3d8 PA	177	ndptr p;
4afad3d8 PA	178
984263bc	179	argv[1] = NULL;
4afad3d8 PA	180	p = macro_getbuiltin(argv[2]);
	181	if (p != NULL)
	182	eval(argv + 1, argc - 1, macro_builtin_type(p), is_traced(p));
984263bc	183	else
4afad3d8	184	m4errx(1, "unknown builtin %s.", argv[2]);
10c3f15b	185	}
984263bc MD	186
	187
	188	/* We need some temporary buffer space, as pb pushes BACK and substitution
	189	* proceeds forward... */
	190	static char *buffer;
	191	static size_t bufsize = 0;
	192	static size_t current = 0;
	193
	194	static void addchars(const char *, size_t);
	195	static void addchar(int);
	196	static char twiddle(const char );
	197	static char *getstring(void);
	198	static void exit_regerror(int, regex_t *);
	199	static void do_subst(const char , regex_t , const char , regmatch_t );
	200	static void do_regexpindex(const char , regex_t , regmatch_t *);
	201	static void do_regexp(const char , regex_t , const char , regmatch_t );
4afad3d8	202	static void add_sub(int, const char , regex_t , regmatch_t *);
984263bc	203	static void add_replace(const char , regex_t , const char , regmatch_t );
4afad3d8	204	#define addconstantstring(s) addchars((s), sizeof(s)-1)
984263bc	205
10c3f15b	206	static void
984263bc MD	207	addchars(const char *c, size_t n)
	208	{
	209	if (n == 0)
	210	return;
	211	while (current + n > bufsize) {
	212	if (bufsize == 0)
	213	bufsize = 1024;
	214	else
	215	bufsize *= 2;
4afad3d8	216	buffer = xrealloc(buffer, bufsize, NULL);
984263bc	217	}
4afad3d8	218	memcpy(buffer + current, c, n);
984263bc MD	219	current += n;
	220	}
	221
10c3f15b	222	static void
984263bc MD	223	addchar(int c)
984263bc MD	224	{
4afad3d8	225	if (current + 1 > bufsize) {
984263bc MD	226	if (bufsize == 0)
	227	bufsize = 1024;
	228	else
	229	bufsize *= 2;
4afad3d8	230	buffer = xrealloc(buffer, bufsize, NULL);
984263bc MD	231	}
	232	buffer[current++] = c;
	233	}
	234
	235	static char *
	236	getstring(void)
	237	{
	238	addchar('\0');
	239	current = 0;
	240	return buffer;
	241	}
	242
	243
10c3f15b	244	static void
984263bc MD	245	exit_regerror(int er, regex_t *re)
984263bc MD	246	{
4afad3d8 PA	247	size_t errlen;
4afad3d8 PA	248	char *errbuf;
984263bc MD	249
984263bc MD	250	errlen = regerror(er, re, NULL, 0);
4afad3d8 PA	251	errbuf = xalloc(errlen,
4afad3d8 PA	252	"malloc in regerror: %lu", (unsigned long)errlen);
984263bc	253	regerror(er, re, errbuf, errlen);
4afad3d8	254	m4errx(1, "regular expression error: %s.", errbuf);
984263bc MD	255	}
	256
	257	static void
4afad3d8	258	add_sub(int n, const char string, regex_t re, regmatch_t *pm)
984263bc	259	{
4afad3d8 PA	260	if (n > (int)re->re_nsub)
4afad3d8 PA	261	warnx("No subexpression %d", n);
984263bc MD	262	/* Subexpressions that did not match are
984263bc MD	263	* not an error. */
4afad3d8 PA	264	else if (pm[n].rm_so != -1 && pm[n].rm_eo != -1)
4afad3d8 PA	265	addchars(string + pm[n].rm_so, pm[n].rm_eo - pm[n].rm_so);
984263bc MD	266	}
	267
	268	/* Add replacement string to the output buffer, recognizing special
	269	* constructs and replacing them with substrings of the original string.
	270	*/
10c3f15b	271	static void
984263bc MD	272	add_replace(const char string, regex_t re, const char replace, regmatch_t pm)
	273	{
	274	const char *p;
	275
	276	for (p = replace; *p != '\0'; p++) {
	277	if (*p == '&' && !mimic_gnu) {
	278	add_sub(0, string, re, pm);
	279	continue;
	280	}
	281	if (*p == '\\') {
	282	if (p[1] == '\\') {
	283	addchar(p[1]);
	284	p++;
	285	continue;
	286	}
	287	if (p[1] == '&') {
	288	if (mimic_gnu)
	289	add_sub(0, string, re, pm);
	290	else
	291	addchar(p[1]);
	292	p++;
	293	continue;
	294	}
	295	if (isdigit(p[1])) {
	296	add_sub(*(++p) - '0', string, re, pm);
	297	continue;
	298	}
	299	}
4afad3d8	300	addchar(*p);
984263bc MD	301	}
	302	}
	303
10c3f15b	304	static void
984263bc MD	305	do_subst(const char string, regex_t re, const char replace, regmatch_t pm)
	306	{
	307	int error;
	308	int flags = 0;
	309	const char *last_match = NULL;
	310
4afad3d8	311	while ((error = regexec(re, string, re->re_nsub + 1, pm, flags)) == 0) {
984263bc	312	if (pm[0].rm_eo != 0) {
4afad3d8	313	if (string[pm[0].rm_eo - 1] == '\n')
984263bc MD	314	flags = 0;
	315	else
	316	flags = REG_NOTBOL;
	317	}
	318
10c3f15b	319	/* NULL length matches are special... We use the `vi-mode'
984263bc	320	* rule: don't allow a NULL-match at the last match
10c3f15b	321	* position.
984263bc	322	*/
10c3f15b	323	if (pm[0].rm_so == pm[0].rm_eo &&
984263bc MD	324	string + pm[0].rm_so == last_match) {
	325	if (*string == '\0')
	326	return;
	327	addchar(*string);
	328	if (*string++ == '\n')
	329	flags = 0;
	330	else
	331	flags = REG_NOTBOL;
	332	continue;
	333	}
	334	last_match = string + pm[0].rm_so;
	335	addchars(string, pm[0].rm_so);
	336	add_replace(string, re, replace, pm);
	337	string += pm[0].rm_eo;
	338	}
	339	if (error != REG_NOMATCH)
	340	exit_regerror(error, re);
	341	pbstr(string);
	342	}
	343
10c3f15b	344	static void
984263bc MD	345	do_regexp(const char string, regex_t re, const char replace, regmatch_t pm)
	346	{
	347	int error;
	348
4afad3d8	349	switch(error = regexec(re, string, re->re_nsub + 1, pm, 0)) {
10c3f15b	350	case 0:
984263bc MD	351	add_replace(string, re, replace, pm);
	352	pbstr(getstring());
	353	break;
	354	case REG_NOMATCH:
	355	break;
	356	default:
	357	exit_regerror(error, re);
	358	}
	359	}
	360
10c3f15b	361	static void
984263bc MD	362	do_regexpindex(const char string, regex_t re, regmatch_t *pm)
	363	{
	364	int error;
	365
4afad3d8	366	switch(error = regexec(re, string, re->re_nsub + 1, pm, 0)) {
984263bc MD	367	case 0:
	368	pbunsigned(pm[0].rm_so);
	369	break;
	370	case REG_NOMATCH:
	371	pbnum(-1);
	372	break;
	373	default:
	374	exit_regerror(error, re);
	375	}
	376	}
	377
	378	/* In Gnu m4 mode, parentheses for backmatch don't work like POSIX 1003.2
	379	* says. So we twiddle with the regexp before passing it to regcomp.
	380	*/
	381	static char *
	382	twiddle(const char *p)
	383	{
4afad3d8 PA	384	/* + at start of regexp is a normal character for Gnu m4 */
	385	if (*p == '^') {
	386	addchar(*p);
	387	p++;
	388	}
	389	if (*p == '+')
	390	addchar('\\');
984263bc MD	391	/* This could use strcspn for speed... */
	392	while (*p != '\0') {
	393	if (*p == '\\') {
	394	switch(p[1]) {
	395	case '(':
	396	case ')':
	397	case '\|':
	398	addchar(p[1]);
	399	break;
	400	case 'w':
	401	addconstantstring("[_a-zA-Z0-9]");
	402	break;
	403	case 'W':
	404	addconstantstring("[^_a-zA-Z0-9]");
	405	break;
	406	case '<':
	407	addconstantstring("[[:<:]]");
	408	break;
	409	case '>':
	410	addconstantstring("[[:>:]]");
	411	break;
	412	default:
	413	addchars(p, 2);
	414	break;
	415	}
4afad3d8	416	p += 2;
984263bc MD	417	continue;
	418	}
	419	if (p == '(' \|\| p == ')' \|\| *p == '\|')
	420	addchar('\\');
	421
	422	addchar(*p);
	423	p++;
	424	}
	425	return getstring();
	426	}
	427
	428	/* patsubst(string, regexp, opt replacement) */
	429	/* argv[2]: string
	430	* argv[3]: regexp
	431	* argv[4]: opt rep
	432	*/
	433	void
	434	dopatsubst(const char *argv[], int argc)
	435	{
984263bc MD	436	if (argc <= 3) {
	437	warnx("Too few arguments to patsubst");
	438	return;
	439	}
4afad3d8 PA	440	/* special case: empty regexp */
	441	if (argv[3][0] == '\0') {
	442	const char *s;
	443	size_t len;
	444	if (argc > 4 && argv[4])
	445	len = strlen(argv[4]);
	446	else
	447	len = 0;
	448	for (s = argv[2]; *s != '\0'; s++) {
	449	addchars(argv[4], len);
	450	addchar(*s);
	451	}
	452	} else {
	453	int error;
	454	regex_t re;
	455	regmatch_t *pmatch;
	456	int mode = REG_EXTENDED;
	457	size_t l = strlen(argv[3]);
	458
	459	if (!mimic_gnu \|\|
	460	(argv[3][0] == '^') \|\|
	461	(l > 0 && argv[3][l-1] == '$'))
	462	mode \|= REG_NEWLINE;
	463
	464	error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3],
	465	mode);
	466	if (error != 0)
	467	exit_regerror(error, &re);
	468
	469	pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub + 1), NULL);
	470	do_subst(argv[2], &re,
	471	argc > 4 && argv[4] != NULL ? argv[4] : "", pmatch);
	472	free(pmatch);
	473	regfree(&re);
	474	}
984263bc	475	pbstr(getstring());
984263bc MD	476	}
	477
	478	void
	479	doregexp(const char *argv[], int argc)
	480	{
	481	int error;
	482	regex_t re;
	483	regmatch_t *pmatch;
	484
	485	if (argc <= 3) {
	486	warnx("Too few arguments to regexp");
	487	return;
	488	}
4afad3d8 PA	489	/* special gnu case */
	490	if (argv[3][0] == '\0' && mimic_gnu) {
	491	if (argc == 4 \|\| argv[4] == NULL)
	492	return;
	493	else
	494	pbstr(argv[4]);
	495	}
10c3f15b	496	error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3],
4afad3d8	497	REG_EXTENDED\|REG_NEWLINE);
984263bc MD	498	if (error != 0)
984263bc MD	499	exit_regerror(error, &re);
10c3f15b	500
4afad3d8 PA	501	pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub + 1), NULL);
4afad3d8 PA	502	if (argc == 4 \|\| argv[4] == NULL)
984263bc MD	503	do_regexpindex(argv[2], &re, pmatch);
	504	else
	505	do_regexp(argv[2], &re, argv[4], pmatch);
	506	free(pmatch);
	507	regfree(&re);
	508	}
	509
	510	void
4afad3d8 PA	511	doformat(const char *argv[], int argc)
	512	{
	513	const char *format = argv[2];
	514	int pos = 3;
	515	int left_padded;
	516	long width;
	517	size_t l;
	518	const char *thisarg = NULL;
	519	char temp[2];
	520	long extra;
	521
	522	while (*format != 0) {
	523	if (*format != '%') {
	524	addchar(*format++);
	525	continue;
	526	}
	527
	528	format++;
	529	if (*format == '%') {
	530	addchar(*format++);
	531	continue;
	532	}
	533	if (*format == 0) {
	534	addchar('%');
	535	break;
	536	}
	537
	538	if (format == '') {
	539	format++;
	540	if (pos >= argc)
	541	m4errx(1,
	542	"Format with too many format specifiers.");
	543	width = strtol(argv[pos++], NULL, 10);
	544	} else {
	545	width = strtol(format, __DECONST(char **, &format), 10);
	546	}
	547	if (width < 0) {
	548	left_padded = 1;
	549	width = -width;
	550	} else {
	551	left_padded = 0;
	552	}
	553	if (*format == '.') {
	554	format++;
	555	if (format == '') {
	556	format++;
	557	if (pos >= argc)
	558	m4errx(1,
	559	"Format with too many format specifiers.");
	560	extra = strtol(argv[pos++], NULL, 10);
	561	} else {
	562	extra = strtol(format, __DECONST(char **, &format), 10);
	563	}
	564	} else {
	565	extra = LONG_MAX;
	566	}
	567	if (pos >= argc)
	568	m4errx(1, "Format with too many format specifiers.");
	569	switch(*format) {
	570	case 's':
	571	thisarg = argv[pos++];
	572	break;
	573	case 'c':
	574	temp[0] = strtoul(argv[pos++], NULL, 10);
575	temp[1] = 0;
576	thisarg = temp;
577	break;
578	default:
579	m4errx(1, "Unsupported format specification: %s.",
580	argv[2]);
581	}
582	format++;
583	l = strlen(thisarg);
584	if ((long)l > extra)
585	l = extra;
586	if (!left_padded) {
587	while ((long)l < width--)
588	addchar(' ');
589	}
590	addchars(thisarg, l);
591	if (left_padded) {
592	while ((long)l < width--)
593	addchar(' ');
594	}
595	}
596	pbstr(getstring());
597	}
598
599	void
984263bc MD	600	doesyscmd(const char *cmd)
	601	{
	602	int p[2];
	603	pid_t pid, cpid;
4afad3d8	604	char *argv[4];
984263bc MD	605	int cc;
	606	int status;
	607
	608	/* Follow gnu m4 documentation: first flush buffers. */
	609	fflush(NULL);
	610
4afad3d8 PA	611	argv[0] = __DECONST(char *, "sh");
	612	argv[1] = __DECONST(char *, "-c");
	613	argv[2] = __DECONST(char *, cmd);
	614	argv[3] = NULL;
	615
984263bc MD	616	/* Just set up standard output, share stderr and stdin with m4 */
	617	if (pipe(p) == -1)
	618	err(1, "bad pipe");
	619	switch(cpid = fork()) {
	620	case -1:
	621	err(1, "bad fork");
	622	/* NOTREACHED */
	623	case 0:
4afad3d8 PA	624	close(p[0]);
	625	dup2(p[1], 1);
	626	close(p[1]);
	627	execv(_PATH_BSHELL, argv);
984263bc MD	628	exit(1);
	629	default:
	630	/* Read result in two stages, since m4's buffer is
	631	* pushback-only. */
4afad3d8	632	close(p[1]);
984263bc MD	633	do {
	634	char result[BUFSIZE];
	635	cc = read(p[0], result, sizeof result);
	636	if (cc > 0)
	637	addchars(result, cc);
	638	} while (cc > 0 \|\| (cc == -1 && errno == EINTR));
	639
4afad3d8	640	close(p[0]);
984263bc MD	641	while ((pid = wait(&status)) != cpid && pid >= 0)
	642	continue;
	643	pbstr(getstring());
	644	}
	645	}
4afad3d8 PA	646
	647	void
	648	getdivfile(const char *name)
	649	{
	650	FILE *f;
	651	int c;
	652
	653	f = fopen(name, "r");
	654	if (!f)
	655	return;
	656
	657	while ((c = getc(f)) != EOF)
	658	putc(c, active);
	659	fclose(f);
	660	}