/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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 <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define ungetchar(c)    ungetc(c, stdin)

/*
 * mkstr - create a string error message file by massaging C source
 *
 * Bill Joy UCB August 1977
 *
 * Modified March 1978 to hash old messages to be able to recompile
 * without addding messages to the message file (usually)
 *
 * Based on an earlier program conceived by Bill Joy and Chuck Haley
 *
 * Program to create a string error message file
 * from a group of C programs.  Arguments are the name
 * of the file where the strings are to be placed, the
 * prefix of the new files where the processed source text
 * is to be placed, and the files to be processed.
 *
 * The program looks for 'error("' in the source stream.
 * Whenever it finds this, the following characters from the '"'
 * to a '"' are replaced by 'seekpt' where seekpt is a
 * pointer into the error message file.
 * If the '(' is not immediately followed by a '"' no change occurs.
 *
 * The optional '-' causes strings to be added at the end of the
 * existing error message file for recompilation of single routines.
 */

static FILE     *mesgread, *mesgwrite;
static char     name[100], *np;

void copystr(void);
int fgetNUL(char *, int, FILE *);
unsigned hashit(char *, int, unsigned);
void inithash(void);
int match(const char *);
int octdigit(char);
void process(void);
void usage(void);

int
main(int argc, char *argv[])
{
        char addon = 0;
        size_t namelen;

        argc--, argv++;
        if (argc > 1 && argv[0][0] == '-')
                addon++, argc--, argv++;
        if (argc < 3)
                usage();
        mesgwrite = fopen(argv[0], addon ? "a" : "w");
        if (mesgwrite == NULL)
                err(1, "%s", argv[0]);
        mesgread = fopen(argv[0], "r");
        if (mesgread == NULL)
                err(1, "%s", argv[0]);
        inithash();
        argc--, argv++;
        namelen = strlcpy(name, argv[0], sizeof(name));
        if (namelen >= sizeof(name)) {
                errno = ENAMETOOLONG;
                err(1, "%s", argv[0]);
        }
        np = name + namelen;
        argc--, argv++;
        do {
                if (strlcpy(np, argv[0], sizeof(name) - namelen) >=
                    sizeof(name) - namelen) {
                        errno = ENAMETOOLONG;
                        err(1, "%s%s", name, argv[0]);
                }
                if (freopen(name, "w", stdout) == NULL)
                        err(1, "%s", name);
                if (freopen(argv[0], "r", stdin) == NULL)
                        err(1, "%s", argv[0]);
                process();
                argc--, argv++;
        } while (argc > 0);
        exit(0);
}

void
usage(void)
{
        fprintf(stderr, "usage: mkstr [-] mesgfile prefix file ...\n");
        exit(1);
}

void
process(void)
{
        int c;

        for (;;) {
                c = getchar();
                if (c == EOF)
                        return;
                if (c != 'e') {
                        putchar(c);
                        continue;
                }
                if (match("error(")) {
                        printf("error(");
                        c = getchar();
                        if (c != '"')
                                putchar(c);
                        else
                                copystr();
                }
        }
}

int
match(const char *ocp)
{
        const char *cp;
        int c;

        for (cp = ocp + 1; *cp; cp++) {
                c = getchar();
                if (c != *cp) {
                        while (ocp < cp)
                                putchar(*ocp++);
                        ungetchar(c);
                        return (0);
                }
        }
        return (1);
}

void
copystr(void)
{
        int c, ch;
        char buf[512];
        char *cp = buf;

        for (;;) {
                if (cp == buf + sizeof(buf) - 2)
                        errx(1, "message too long");
                c = getchar();
                if (c == EOF)
                        break;
                switch (c) {

                case '"':
                        *cp++ = 0;
                        goto out;
                case '\\':
                        c = getchar();
                        switch (c) {

                        case 'b':
                                c = '\b';
                                break;
                        case 't':
                                c = '\t';
                                break;
                        case 'r':
                                c = '\r';
                                break;
                        case 'n':
                                c = '\n';
                                break;
                        case '\n':
                                continue;
                        case 'f':
                                c = '\f';
                                break;
                        case '0':
                                c = 0;
                                break;
                        case '\\':
                                break;
                        default:
                                if (!octdigit(c))
                                        break;
                                c -= '0';
                                ch = getchar();
                                if (!octdigit(ch))
                                        break;
                                c <<= 7, c += ch - '0';
                                ch = getchar();
                                if (!octdigit(ch))
                                        break;
                                c <<= 3, c+= ch - '0', ch = -1;
                                break;
                        }
                }
                *cp++ = c;
        }
out:
        *cp = 0;
        printf("%d", hashit(buf, 1, 0));
}

int
octdigit(char c)
{

        return (c >= '0' && c <= '7');
}

void
inithash(void)
{
        char buf[512];
        int mesgpt = 0;

        rewind(mesgread);
        while (fgetNUL(buf, sizeof buf, mesgread) != 0) {
                hashit(buf, 0, mesgpt);
                mesgpt += strlen(buf) + 2;
        }
}

#define NBUCKETS        511

static struct   hash {
        long    hval;
        unsigned hpt;
        struct  hash *hnext;
} *bucket[NBUCKETS];

unsigned
hashit(char *str, int really, unsigned fakept)
{
        int i;
        struct hash *hp;
        char buf[512];
        long hashval = 0;
        char *cp;

        if (really)
                fflush(mesgwrite);
        for (cp = str; *cp;)
                hashval = (hashval << 1) + *cp++;
        i = hashval % NBUCKETS;
        if (i < 0)
                i += NBUCKETS;
        if (really != 0)
                for (hp = bucket[i]; hp != 0; hp = hp->hnext)
                if (hp->hval == hashval) {
                        fseek(mesgread, (long) hp->hpt, 0);
                        fgetNUL(buf, sizeof buf, mesgread);
/*
                        fprintf(stderr, "Got (from %d) %s\n", hp->hpt, buf);
*/
                        if (strcmp(buf, str) == 0)
                                break;
                }
        if (!really || hp == 0) {
                hp = (struct hash *) calloc(1, sizeof *hp);
                if (hp == NULL)
                        err(1, NULL);
                hp->hnext = bucket[i];
                hp->hval = hashval;
                hp->hpt = really ? ftell(mesgwrite) : fakept;
                if (really) {
                        fwrite(str, sizeof (char), strlen(str) + 1, mesgwrite);
                        fwrite("\n", sizeof (char), 1, mesgwrite);
                }
                bucket[i] = hp;
        }
/*
        fprintf(stderr, "%s hashed to %ld at %d\n", str, hp->hval, hp->hpt);
*/
        return (hp->hpt);
}

int
fgetNUL(char *obuf, int rmdr, FILE *file)
{
        int c;
        char *buf = obuf;

        while (--rmdr > 0 && (c = getc(file)) != 0 && c != EOF)
                *buf++ = c;
        *buf++ = 0;
        getc(file);
        return ((feof(file) || ferror(file)) ? 0 : 1);
}