/*      $OpenBSD: misc.c,v 1.47 2017/06/15 13:48:42 bcallah Exp $       */
/*      $NetBSD: misc.c,v 1.6 1995/09/28 05:37:41 tls Exp $     */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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. 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.
 */

#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdint.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 */
char *endest;           /* end of string space         */
static size_t strsize = STRSPMAX;
static size_t bufsize = BUFSIZE;

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


/*
 * find the index of second str in the first str.
 */
ptrdiff_t
doindex(const char *s1, const char *s2)
{
        char *t;

        t = strstr(s1, s2);
        if (t == NULL)
                return (-1);
        else
                return (t - s1);
}
/*
 *  pushback - push character back onto input
 */
void
pushback(int c)
{
        if (c == EOF)
                return;
        if (bp >= endpbb)
                enlarge_bufspace();
        *bp++ = c;
}

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

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

/*
 *  pbnum - convert number to string, push back on input.
 */
void
pbnum(int n)
{
        pbnumbase(n, 10, 0);
}

void
pbnumbase(int n, int base, int d)
{
        static char digits[36] __nonstring =
            "0123456789abcdefghijklmnopqrstuvwxyz";
        unsigned int num;
        int printed = 0;

        if (base > 36)
                m4errx(1, "base %d > 36: not supported.", base);

        if (base < 2)
                m4errx(1, "bad base %d for conversion.", base);

        num = (n < 0) ? -n : n;
        do {
                pushback(digits[num % base]);
                printed++;
        } while ((num /= base) > 0);

        while (printed++ < d)
                pushback('0');

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

/*
 *  pbunsigned - convert unsigned long to string, push back on input.
 */
void
pbunsigned(unsigned long n)
{
        do {
                pushback(n % 10 + '0');
        } while ((n /= 10) > 0);
}

void
initspaces(void)
{
        int i;

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

void
enlarge_strspace(void)
{
        char *newstrspace;
        int i;

        strsize *= 2;
        newstrspace = malloc(strsize + 1);
        if (!newstrspace)
                errx(1, "string space overflow");
        memcpy(newstrspace, strspace, strsize/2);
        for (i = 0; i <= sp; i++)
                if (sstack[i] == STORAGE_STRSPACE)
                        mstack[i].sstr = (mstack[i].sstr - strspace) +
                            newstrspace;
        ep = (ep - strspace) + newstrspace;
        free(strspace);
        strspace = newstrspace;
        endest = strspace + strsize;
}

void
enlarge_bufspace(void)
{
        unsigned char *newbuf;
        int i;

        bufsize += bufsize/2;
        newbuf = xrealloc(buf, bufsize, "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(int c)
{
        if (ep >= endest)
                enlarge_strspace();
        *ep++ = c;
}

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

        if (active == outfile[n])
                m4errx(1, "undivert: diversion still active.");
        rewind(outfile[n]);
        while ((c = getc(outfile[n])) != EOF)
                putc(c, active);
        (void) fclose(outfile[n]);
        outfile[n] = NULL;
}

void
onintr(int signo __unused)
{
#define intrmessage     "m4: interrupted.\n"
        write(STDERR_FILENO, intrmessage, sizeof(intrmessage)-1);
        _exit(1);
}

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

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

extern char *__progname;

void
m4errx(int eval, const char *fmt, ...)
{
        fprintf(stderr, "%s: ", __progname);
        fprintf(stderr, "%s at line %lu: ", CURRENT_NAME, CURRENT_LINE);
        if (fmt != NULL) {
                va_list ap;

                va_start(ap, fmt);
                vfprintf(stderr, fmt, ap);
                va_end(ap);
        }
        fprintf(stderr, "\n");
        exit(eval);
}

/*
 * resizedivs: allocate more diversion files */
void
resizedivs(int n)
{
        int i;

        outfile = xreallocarray(outfile, n, sizeof(FILE *),
            "too many diverts %d", n);
        for (i = maxout; i < n; i++)
                outfile[i] = NULL;
        maxout = n;
}

void *
xalloc(size_t n, const char *fmt, ...)
{
        void *p = malloc(n);

        if (p == NULL) {
                if (fmt == NULL)
                        err(1, "malloc");
                else {
                        va_list va;

                        va_start(va, fmt);
                        verr(1, fmt, va);
                        va_end(va);
                }
        }
        return p;
}

void *
xcalloc(size_t n, size_t s, const char *fmt, ...)
{
        void *p = calloc(n, s);

        if (p == NULL) {
                if (fmt == NULL)
                        err(1, "calloc");
                else {
                        va_list va;

                        va_start(va, fmt);
                        verr(1, fmt, va);
                        va_end(va);
                }
        }
        return p;
}

void *
xrealloc(void *old, size_t n, const char *fmt, ...)
{
        char *p = realloc(old, n);

        if (p == NULL) {
                free(old);
                if (fmt == NULL)
                        err(1, "realloc");
                else {
                        va_list va;

                        va_start(va, fmt);
                        verr(1, fmt, va);
                        va_end(va);
                }
        }
        return p;
}

void *
xreallocarray(void *old, size_t s1, size_t s2, const char *fmt, ...)
{
        void *p = reallocarray(old, s1, s2);

        if (p == NULL) {
                free(old);
                if (fmt == NULL)
                        err(1, "reallocarray");
                else {
                        va_list va;

                        va_start(va, fmt);
                        verr(1, fmt, va);
                        va_end(va);
                }
        }
        return p;
}

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

void
usage(void)
{
        fprintf(stderr, "usage: m4 [-EgPs] [-Dname[=value]] [-d flags] "
                        "[-I dirname] [-o filename]\n"
                        "\t[-t macro] [-Uname] [file ...]\n");
        exit(1);
}

int
obtain_char(struct input_file *f)
{
        if (f->c == EOF)
                return EOF;

        f->c = fgetc(f->file);
        if (f->c == '\n')
                f->lineno++;

        return f->c;
}

void
set_input(struct input_file *f, FILE *real, const char *name)
{
        f->file = real;
        f->lineno = 1;
        f->c = 0;
        f->name = xstrdup(name);
        emit_synchline();
}

void
do_emit_synchline(void)
{
        fprintf(active, "#line %lu \"%s\"\n",
            infile[ilevel].lineno, infile[ilevel].name);
        infile[ilevel].synch_lineno = infile[ilevel].lineno;
}

void
release_input(struct input_file *f)
{
        if (ferror(f->file))
                errx(1, "Fatal error reading from %s\n", f->name);
        if (f->file != stdin)
            fclose(f->file);
        f->c = EOF;
        /*
         * XXX can't free filename, as there might still be
         * error information pointing to it.
         */
}

void
doprintlineno(struct input_file *f)
{
        pbunsigned(f->lineno);
}

void
doprintfilename(struct input_file *f)
{
        pbstr(rquote);
        pbstr(f->name);
        pbstr(lquote);
}

/*
 * buffer_mark/dump_buffer: allows one to save a mark in a buffer,
 * and later dump everything that was added since then to a file.
 */
size_t
buffer_mark(void)
{
        return bp - buf;
}


void
dump_buffer(FILE *f, size_t m)
{
        unsigned char *s;

        for (s = bp; s-buf > (long)m;)
                fputc(*--s, f);
}