/*-
 * 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 <sys/types.h>

#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>

#include "pathnames.h"

/*
 * xstr - extract and hash strings in a C program
 *
 * Bill Joy UCB
 * November, 1978
 */

#define ignore(a)       ((void) a)

static off_t    tellpt;

static off_t    mesgpt;
static char     cstrings[] =    "strings";
static char     *strings =      cstrings;

static int      cflg;
static int      vflg;
static int      readstd;

static char lastchr(char *);

static int fgetNUL(char *, int, FILE *);
static int istail(char *, char *);
static int octdigit(char);
static int xgetc(FILE *);

static off_t hashit(char *, int);
static off_t yankstr(char **);

static void usage(void) __dead2;

static void flushsh(void);
static void found(int, off_t, char *);
static void inithash(void);
static void onintr(int);
static void process(const char *);
static void prstr(char *);
static void xsdotc(void);

int
main(int argc, char *argv[])
{
        int c;
        int fdesc;

        while ((c = getopt(argc, argv, "-cv")) != -1)
                switch (c) {
                case '-':
                        readstd++;
                        break;
                case 'c':
                        cflg++;
                        break;
                case 'v':
                        vflg++;
                        break;
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;
                
        if (signal(SIGINT, SIG_IGN) == SIG_DFL)
                signal(SIGINT, onintr);
        if (cflg || (argc == 0 && !readstd))
                inithash();
        else {
                strings = strdup(_PATH_TMP);
                if (strings == NULL)
                        err(1, "strdup() failed");
                fdesc = mkstemp(strings);
                if (fdesc == -1)
                        err(1, "Unable to create temporary file");
                close(fdesc);
        }

        while (readstd || argc > 0) {
                if (freopen("x.c", "w", stdout) == NULL)
                        err(1, "x.c");
                if (!readstd && freopen(argv[0], "r", stdin) == NULL)
                        err(2, "%s", argv[0]);
                process("x.c");
                if (readstd == 0)
                        argc--, argv++;
                else
                        readstd = 0;
        }
        flushsh();
        if (cflg == 0)
                xsdotc();
        if (strings[0] == '/')
                ignore(unlink(strings));
        exit(0);
}

static void
usage(void)
{
        fprintf(stderr, "usage: xstr [-cv] [-] [file ...]\n");
        exit (1);
}

static char linebuf[BUFSIZ];

static void
process(const char *name)
{
        char *cp;
        int c;
        int incomm = 0;
        int ret;

        printf("extern char\txstr[];\n");
        for (;;) {
                if (fgets(linebuf, sizeof linebuf, stdin) == NULL) {
                        if (ferror(stdin))
                                err(3, "%s", name);
                        break;
                }
                if (linebuf[0] == '#') {
                        if (linebuf[1] == ' ' && isdigit(linebuf[2]))
                                printf("#line%s", &linebuf[1]);
                        else
                                printf("%s", linebuf);
                        continue;
                }
                for (cp = linebuf; (c = *cp++);) switch (c) {

                case '"':
                        if (incomm)
                                goto def;
                        if ((ret = (int) yankstr(&cp)) == -1)
                                goto out;
                        printf("(&xstr[%d])", ret);
                        break;

                case '\'':
                        if (incomm)
                                goto def;
                        putchar(c);
                        if (*cp)
                                putchar(*cp++);
                        break;

                case '/':
                        if (incomm || *cp != '*')
                                goto def;
                        incomm = 1;
                        cp++;
                        printf("/*");
                        continue;

                case '*':
                        if (incomm && *cp == '/') {
                                incomm = 0;
                                cp++;
                                printf("*/");
                                continue;
                        }
                        goto def;

def:
                default:
                        putchar(c);
                        break;
                }
        }
out:
        if (ferror(stdout))
                warn("x.c"), onintr(0);
}

static off_t
yankstr(char **cpp)
{
        char *cp = *cpp;
        int c, ch;
        char dbuf[BUFSIZ];
        char *dp = dbuf;
        char *tp;
        static char tmp[] = "b\bt\tr\rn\nf\f\\\\\"\"";

        while ((c = *cp++)) {
                if (dp == dbuf + sizeof(dbuf) - 3)
                        errx(1, "message too long");
                switch (c) {

                case '"':
                        cp++;
                        goto out;

                case '\\':
                        c = *cp++;
                        if (c == 0)
                                break;
                        if (c == '\n') {
                                if (fgets(linebuf, sizeof linebuf, stdin)
                                    == NULL) {
                                        if (ferror(stdin))
                                                err(3, "x.c");
                                        return(-1);
                                }
                                cp = linebuf;
                                continue;
                        }
                        for (tp = tmp; (ch = *tp++); tp++)
                                if (c == ch) {
                                        c = *tp;
                                        goto gotc;
                                }
                        if (!octdigit(c)) {
                                *dp++ = '\\';
                                break;
                        }
                        c -= '0';
                        if (!octdigit(*cp))
                                break;
                        c <<= 3, c += *cp++ - '0';
                        if (!octdigit(*cp))
                                break;
                        c <<= 3, c += *cp++ - '0';
                        break;
                }
gotc:
                *dp++ = c;
        }
out:
        *cpp = --cp;
        *dp = 0;
        return (hashit(dbuf, 1));
}

static int
octdigit(char c)
{
        return (isdigit(c) && c != '8' && c != '9');
}

static void
inithash(void)
{
        char buf[BUFSIZ];
        FILE *mesgread = fopen(strings, "r");

        if (mesgread == NULL)
                return;
        for (;;) {
                mesgpt = tellpt;
                if (fgetNUL(buf, sizeof buf, mesgread) == 0)
                        break;
                ignore(hashit(buf, 0));
        }
        ignore(fclose(mesgread));
}

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

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

static int
xgetc(FILE *file)
{

        tellpt++;
        return (getc(file));
}

#define BUCKETS 128

static struct hash {
        off_t   hpt;
        char    *hstr;
        struct  hash *hnext;
        short   hnew;
} bucket[BUCKETS];

static off_t
hashit(char *str, int new)
{
        int i;
        struct hash *hp, *hp0;

        hp = hp0 = &bucket[lastchr(str) & 0177];
        while (hp->hnext) {
                hp = hp->hnext;
                i = istail(str, hp->hstr);
                if (i >= 0)
                        return (hp->hpt + i);
        }
        if ((hp = (struct hash *) calloc(1, sizeof (*hp))) == NULL)
                errx(8, "calloc");
        hp->hpt = mesgpt;
        if (!(hp->hstr = strdup(str)))
                err(1, NULL);
        mesgpt += strlen(hp->hstr) + 1;
        hp->hnext = hp0->hnext;
        hp->hnew = new;
        hp0->hnext = hp;
        return (hp->hpt);
}

static void
flushsh(void)
{
        int i;
        struct hash *hp;
        FILE *mesgwrit;
        int old = 0, new = 0;

        for (i = 0; i < BUCKETS; i++)
                for (hp = bucket[i].hnext; hp != NULL; hp = hp->hnext)
                        if (hp->hnew)
                                new++;
                        else
                                old++;
        if (new == 0 && old != 0)
                return;
        mesgwrit = fopen(strings, old ? "r+" : "w");
        if (mesgwrit == NULL)
                err(4, "%s", strings);
        for (i = 0; i < BUCKETS; i++)
                for (hp = bucket[i].hnext; hp != NULL; hp = hp->hnext) {
                        found(hp->hnew, hp->hpt, hp->hstr);
                        if (hp->hnew) {
                                fseek(mesgwrit, hp->hpt, 0);
                                ignore(fwrite(hp->hstr, strlen(hp->hstr) + 1, 1, mesgwrit));
                                if (ferror(mesgwrit))
                                        err(4, "%s", strings);
                        }
                }
        if (fclose(mesgwrit) == EOF)
                err(4, "%s", strings);
}

static void
found(int new, off_t off, char *str)
{
        if (vflg == 0)
                return;
        if (!new)
                fprintf(stderr, "found at %d:", (int) off);
        else
                fprintf(stderr, "new at %d:", (int) off);
        prstr(str);
        fprintf(stderr, "\n");
}

static void
prstr(char *cp)
{
        int c;

        while ((c = (*cp++ & 0377)))
                if (c < ' ')
                        fprintf(stderr, "^%c", c + '`');
                else if (c == 0177)
                        fprintf(stderr, "^?");
                else if (c > 0200)
                        fprintf(stderr, "\\%03o", c);
                else
                        fprintf(stderr, "%c", c);
}

static void
xsdotc(void)
{
        FILE *strf = fopen(strings, "r");
        FILE *xdotcf;

        if (strf == NULL)
                err(5, "%s", strings);
        xdotcf = fopen("xs.c", "w");
        if (xdotcf == NULL)
                err(6, "xs.c");
        fprintf(xdotcf, "char\txstr[] = {\n");
        for (;;) {
                int i, c;

                for (i = 0; i < 8; i++) {
                        c = getc(strf);
                        if (ferror(strf)) {
                                warn("%s", strings);
                                onintr(0);
                        }
                        if (feof(strf)) {
                                fprintf(xdotcf, "\n");
                                goto out;
                        }
                        fprintf(xdotcf, "0x%02x,", c);
                }
                fprintf(xdotcf, "\n");
        }
out:
        fprintf(xdotcf, "};\n");
        ignore(fclose(xdotcf));
        ignore(fclose(strf));
}

static char
lastchr(char *cp)
{

        while (cp[0] && cp[1])
                cp++;
        return (*cp);
}

static int
istail(char *str, char *of)
{
        int d = strlen(of) - strlen(str);

        if (d < 0 || strcmp(&of[d], str) != 0)
                return (-1);
        return (d);
}

static void
onintr(int dummy __unused)
{

        ignore(signal(SIGINT, SIG_IGN));
        if (strings[0] == '/')
                ignore(unlink(strings));
        ignore(unlink("x.c"));
        ignore(unlink("xs.c"));
        exit(7);
}