Return to gnum4.c CVS log

Up to [local] / src / usr.bin / m4

add more gnum4 support: regexps do weird things with empty patterns (this
is required for newer autoconf).
fix the tokenizer for gnu extensions, allowing digits out of range is
ridiculous.
add POSIX2008 mkstemp and document it (also documenting that mktemp is
safe, not posix...)
tidy the manpage, do extra .Nm m4 -> .Nm.
okay otto@, miod@, jmc@

/* $OpenBSD: gnum4.c,v 1.40 2010/03/22 20:40:43 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.
 */

/* 
 * 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
 */

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)
		errx(1, "out of memory");
	n->name = strdup(dirname);
	if (!n->name)
		errx(1, "out of memory");
	n->next = 0;
	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()
{
	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)
		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")) != 0) {
			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;

	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()
{
	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 > 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);
	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;
	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, (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, (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 (l > extra)
			l = extra;
		if (!left_padded) {
			while (l < width--)
				addchar(' ');
		}
		addchars(thisarg, l);
		if (left_padded) {
			while (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] = "sh";
	argv[1] = "-c";
	argv[2] = (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:
		(void) close(p[0]);
		(void) dup2(p[1], 1);
		(void) close(p[1]);
		execv(_PATH_BSHELL, argv);
		exit(1);
	default:
		/* Read result in two stages, since m4's buffer is
		 * pushback-only. */
		(void) 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));

		(void) 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);
	(void) fclose(f);
}