/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1987, 1993, 1994, 1995
 *      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 <sys/stat.h>
#include <sys/wait.h>

#include <err.h>
#include <errno.h>
#include <limits.h>
#include <locale.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "ctags.h"

/*
 * ctags: create a tags file
 */

NODE    *head;                  /* head of the sorted binary tree */

                                /* boolean "func" (see init()) */
bool    _wht[256], _etk[256], _itk[256], _btk[256], _gd[256];

FILE    *inf;                   /* ioptr for current input file */
FILE    *outf;                  /* ioptr for tags file */

long    lineftell;              /* ftell after getc( inf ) == '\n' */

int     lineno;                 /* line number of current line */
int     dflag;                  /* -d: non-macro defines */
int     tflag;                  /* -t: create tags for typedefs */
int     vflag;                  /* -v: vgrind style index output */
int     wflag;                  /* -w: suppress warnings */
int     xflag;                  /* -x: cxref style output */

char    *curfile;               /* current input file name */
char    searchar = '/';         /* use /.../ searches by default */
char    lbuf[LINE_MAX];

void    init(void);
void    find_entries(char *);
static void usage(void) __dead2;

int
main(int argc, char **argv)
{
        static const char       *outfile = "tags";      /* output file */
        int     aflag;                          /* -a: append to tags */
        int     uflag;                          /* -u: update tags */
        int     exit_val;                       /* exit value */
        int     step;                           /* step through args */
        int     ch;                             /* getopts char */

        setlocale(LC_ALL, "");

        aflag = uflag = false;
        tflag = true;
        while ((ch = getopt(argc, argv, "BFTadf:tuwvx")) != -1)
                switch(ch) {
                case 'B':
                        searchar = '?';
                        break;
                case 'F':
                        searchar = '/';
                        break;
                case 'T':
                        tflag = false;
                        break;
                case 'a':
                        aflag++;
                        break;
                case 'd':
                        dflag++;
                        break;
                case 'f':
                        outfile = optarg;
                        break;
                case 't':
                        tflag = true;
                        break;
                case 'u':
                        uflag++;
                        break;
                case 'w':
                        wflag++;
                        break;
                case 'v':
                        vflag++;
                case 'x':
                        xflag++;
                        break;
                case '?':
                default:
                        usage();
                }
        argv += optind;
        argc -= optind;
        if (!argc)
                usage();

        if (strcmp(outfile, "-") == 0)
                outfile = "/dev/stdout";

        if (!xflag)
                setlocale(LC_COLLATE, "C");

        init();

        for (exit_val = step = 0; step < argc; ++step)
                if (!(inf = fopen(argv[step], "r"))) {
                        warn("%s", argv[step]);
                        exit_val = 1;
                }
                else {
                        curfile = argv[step];
                        find_entries(argv[step]);
                        (void)fclose(inf);
                }

        if (head) {
                if (xflag)
                        put_entries(head);
                else {
                        if (uflag) {
                                struct stat sb;
                                FILE *oldf;
                                regex_t *regx;

                                if ((oldf = fopen(outfile, "r")) == NULL) {
                                        if (errno == ENOENT) {
                                                uflag = 0;
                                                goto udone;
                                        }
                                        err(1, "opening %s", outfile);
                                }
                                if (fstat(fileno(oldf), &sb) != 0 ||
                                    !S_ISREG(sb.st_mode)) {
                                        fclose(oldf);
                                        uflag = 0;
                                        goto udone;
                                }
                                if (unlink(outfile))
                                        err(1, "unlinking %s", outfile);
                                if ((outf = fopen(outfile, "w")) == NULL)
                                        err(1, "recreating %s", outfile);
                                if ((regx = calloc(argc, sizeof(regex_t))) == NULL)
                                        err(1, "RE alloc");
                                for (step = 0; step < argc; step++) {
                                        (void)strcpy(lbuf, "\t");
                                        (void)strlcat(lbuf, argv[step], LINE_MAX);
                                        (void)strlcat(lbuf, "\t", LINE_MAX);
                                        if (regcomp(regx + step, lbuf,
                                            REG_NOSPEC))
                                                warn("RE compilation failed");
                                }
nextline:
                                while (fgets(lbuf, LINE_MAX, oldf)) {
                                        for (step = 0; step < argc; step++)
                                                if (regexec(regx + step,
                                                    lbuf, 0, NULL, 0) == 0)
                                                        goto nextline;
                                        fputs(lbuf, outf);
                                }
                                for (step = 0; step < argc; step++)
                                        regfree(regx + step);
                                free(regx);
                                fclose(oldf);
                                fclose(outf);
                                ++aflag;
                        }
udone:
                        if (!(outf = fopen(outfile, aflag ? "a" : "w")))
                                err(1, "%s", outfile);
                        put_entries(head);
                        (void)fclose(outf);
                        if (uflag) {
                                pid_t pid;

                                if ((pid = fork()) == -1)
                                        err(1, "fork failed");
                                else if (pid == 0) {
                                        execlp("sort", "sort", "-o", outfile,
                                            outfile, NULL);
                                        err(1, "exec of sort failed");
                                }
                                /* Just assume the sort went OK. The old code
                                   did not do any checks either. */
                                (void)wait(NULL);
                        }
                }
        }
        if (ferror(stdout) != 0 || fflush(stdout) != 0)
                err(1, "stdout");
        exit(exit_val);
}

static void
usage(void)
{
        (void)fprintf(stderr, "usage: ctags [-BFTaduwvx] [-f tagsfile] file ...\n");
        exit(1);
}

/*
 * init --
 *      this routine sets up the boolean pseudo-functions which work by
 *      setting boolean flags dependent upon the corresponding character.
 *      Every char which is NOT in that string is false with respect to
 *      the pseudo-function.  Therefore, all of the array "_wht" is NO
 *      by default and then the elements subscripted by the chars in
 *      CWHITE are set to YES.  Thus, "_wht" of a char is YES if it is in
 *      the string CWHITE, else NO.
 */
void
init(void)
{
        int             i;
        const unsigned char     *sp;

        for (i = 0; i < 256; i++) {
                _wht[i] = _etk[i] = _itk[i] = _btk[i] = false;
                _gd[i] = true;
        }
#define CWHITE  " \f\t\n"
        for (sp = CWHITE; *sp; sp++)    /* white space chars */
                _wht[*sp] = true;
#define CTOKEN  " \t\n\"'#()[]{}=-+%*/&|^~!<>;,.:?"
        for (sp = CTOKEN; *sp; sp++)    /* token ending chars */
                _etk[*sp] = true;
#define CINTOK  "ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz0123456789"
        for (sp = CINTOK; *sp; sp++)    /* valid in-token chars */
                _itk[*sp] = true;
#define CBEGIN  "ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz"
        for (sp = CBEGIN; *sp; sp++)    /* token starting chars */
                _btk[*sp] = true;
#define CNOTGD  ",;"
        for (sp = CNOTGD; *sp; sp++)    /* invalid after-function chars */
                _gd[*sp] = false;
}

/*
 * find_entries --
 *      this routine opens the specified file and calls the function
 *      which searches the file.
 */
void
find_entries(char *file)
{
        char    *cp;

        lineno = 0;                             /* should be 1 ?? KB */
        if ((cp = strrchr(file, '.'))) {
                if (cp[1] == 'l' && !cp[2]) {
                        int     c;

                        for (;;) {
                                if (GETC(==, EOF))
                                        return;
                                if (!iswhite(c)) {
                                        rewind(inf);
                                        break;
                                }
                        }
#define LISPCHR ";(["
/* lisp */              if (strchr(LISPCHR, c)) {
                                l_entries();
                                return;
                        }
/* lex */               else {
                                /*
                                 * we search all 3 parts of a lex file
                                 * for C references.  This may be wrong.
                                 */
                                toss_yysec();
                                (void)strcpy(lbuf, "%%$");
                                pfnote("yylex", lineno);
                                rewind(inf);
                        }
                }
/* yacc */      else if (cp[1] == 'y' && !cp[2]) {
                        /*
                         * we search only the 3rd part of a yacc file
                         * for C references.  This may be wrong.
                         */
                        toss_yysec();
                        (void)strcpy(lbuf, "%%$");
                        pfnote("yyparse", lineno);
                        y_entries();
                }
/* fortran */   else if ((cp[1] != 'c' && cp[1] != 'h') && !cp[2]) {
                        if (PF_funcs())
                                return;
                        rewind(inf);
                }
        }
/* C */ c_entries();
}