/*	$OpenBSD: misc.c,v 1.10 1999/09/09 22:18:19 espie Exp $	*/
/*	$NetBSD: misc.c,v 1.6 1995/09/28 05:37:41 tls Exp $	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ozan Yigit at York University.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * 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.
 */

#ifndef lint
#if 0
static char sccsid[] = "@(#)misc.c	8.1 (Berkeley) 6/6/93";
#else
static char rcsid[] = "$OpenBSD: misc.c,v 1.10 1999/09/09 22:18:19 espie Exp $";
#endif
#endif /* not lint */

#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <err.h>
#include "mdef.h"
#include "stdd.h"
#include "extern.h"
#include "pathnames.h"


char *ep;		/* first free char in strspace */
static char *strspace;	/* string space for evaluation */
static char *endest;	/* end of string space	       */
static size_t strsize = STRSPMAX;
static size_t bufsize = BUFSIZE;
static int low_sp = 0;

pbent *buf;			/* push-back buffer	       */
pbent *bufbase;			/* the base for current ilevel */
pbent *bbase[MAXINP];		/* the base for each ilevel    */
pbent *bp; 			/* first available character   */
static pbent *endpbb;			/* end of push-back buffer     */


static void enlarge_bufspace();
static void enlarge_strspace();
/*
 * find the index of second str in the first str.
 */
ptrdiff_t
indx(s1, s2)
const char *s1;
const char *s2;
{
	char *r;

	r = strstr(s1, s2);
	if (r)
		return (r - s1);
	else
		return (-1);
}
/*
 *  putback - push character back onto input
 */
void
putback(c)
pbent c;
{
	if (bp >= endpbb)
		enlarge_bufspace();
	*bp++ = c;
}

/*
 *  pbstr - push string back onto input
 *          putback is replicated to improve
 *          performance.
 */
void
pbstr(s)
register char *s;
{
	size_t n;

	n = strlen(s);
	while (endpbb - bp < n)
		enlarge_bufspace();
	while (n > 0)
		*bp++ = s[--n];
}

/*
 *  pbnum - convert number to string, push back on input.
 */
void
pbnum(n)
int n;
{
	register int num;

	num = (n < 0) ? -n : n;
	do {
		putback(num % 10 + '0');
	}
	while ((num /= 10) > 0);

	if (n < 0)
		putback('-');
}


void 
initspaces()
{
	int i;

	strspace = xalloc(strsize+1);
	ep = strspace;
	endest = strspace+strsize;
	buf = (pbent *)xalloc(bufsize * sizeof(pbent));
	bufbase = buf;
	bp = buf;
	endpbb = buf + bufsize;
	for (i = 0; i < MAXINP; i++)
		bbase[i] = buf;
}

/* XXX when chrsave is called, the current argument is
 * always topmost on the stack.  We make use of this to
 * duplicate it transparently, and to reclaim the correct
 * space when the stack is unwound.
 */
static
void enlarge_strspace()
{
	char *newstrspace;

	low_sp = sp;
	strsize *= 2;
	newstrspace = malloc(strsize + 1);
	if (!newstrspace)
		errx(1, "string space overflow");
	memcpy(newstrspace, strspace, strsize/2);
		/* reclaim memory in the easy, common case. */
	if (ep == strspace)
		free(strspace);
	mstack[sp].sstr = (mstack[sp].sstr-strspace) + newstrspace;
	ep = (ep-strspace) + newstrspace;
	strspace = newstrspace;
	endest = strspace + strsize;
}

static
void enlarge_bufspace()
{
	pbent *newbuf;
	int i;

	bufsize *= 2;
	newbuf = realloc(buf, bufsize*sizeof(pbent));
	if (!newbuf)
		errx(1, "too many characters pushed back");
	for (i = 0; i < MAXINP; i++)
		bbase[i] = (bbase[i]-buf)+newbuf;
	bp = (bp-buf)+newbuf;
	bufbase = (bufbase-buf)+newbuf;
	buf = newbuf;
	endpbb = buf+bufsize;
}

/*
 *  chrsave - put single char on string space
 */
void
chrsave(c)
char c;
{
	if (ep >= endest) 
		enlarge_strspace();
	*ep++ = c;
}

/* 
 * so we reclaim what string space we can
 */
char * 
compute_prevep()
{
	if (fp+3 <= low_sp)
		{
		return strspace;
		}
	else
		{
		return mstack[fp+3].sstr;
		}
}

/*
 * read in a diversion file, and dispose it.
 */
void
getdiv(n)
int n;
{
	register int c;

	if (active == outfile[n])
		errx(1, "undivert: diversion still active");
	rewind(outfile[n]);
	while ((c = getc(outfile[n])) != EOF)
		putc(c, active);
	(void) fclose(outfile[n]);
}

void
onintr(signo)
	int signo;
{
	errx(1, "interrupted.");
}

/*
 * killdiv - get rid of the diversion files
 */
void
killdiv()
{
	register int n;

	for (n = 0; n < MAXOUT; n++)
		if (outfile[n] != NULL) {
			(void) fclose(outfile[n]);
		}
}

char *
xalloc(n)
unsigned long n;
{
	register char *p = malloc(n);

	if (p == NULL)
		err(1, "malloc");
	return p;
}

char *
xstrdup(s)
const char *s;
{
	register char *p = strdup(s);
	if (p == NULL)
		err(1, "strdup");
	return p;
}

void
usage()
{
	fprintf(stderr, "usage: m4 [-Dname[=val]] [-Uname]\n");
	exit(1);
}