builtin-grep.con commit rebase: Support preserving merges in non-interactive mode (f8cca01)
   1/*
   2 * Builtin "git grep"
   3 *
   4 * Copyright (c) 2006 Junio C Hamano
   5 */
   6#include "cache.h"
   7#include "blob.h"
   8#include "tree.h"
   9#include "commit.h"
  10#include "tag.h"
  11#include "tree-walk.h"
  12#include "builtin.h"
  13#include "grep.h"
  14
  15#ifndef NO_EXTERNAL_GREP
  16#ifdef __unix__
  17#define NO_EXTERNAL_GREP 0
  18#else
  19#define NO_EXTERNAL_GREP 1
  20#endif
  21#endif
  22
  23/*
  24 * git grep pathspecs are somewhat different from diff-tree pathspecs;
  25 * pathname wildcards are allowed.
  26 */
  27static int pathspec_matches(const char **paths, const char *name)
  28{
  29        int namelen, i;
  30        if (!paths || !*paths)
  31                return 1;
  32        namelen = strlen(name);
  33        for (i = 0; paths[i]; i++) {
  34                const char *match = paths[i];
  35                int matchlen = strlen(match);
  36                const char *cp, *meta;
  37
  38                if (!matchlen ||
  39                    ((matchlen <= namelen) &&
  40                     !strncmp(name, match, matchlen) &&
  41                     (match[matchlen-1] == '/' ||
  42                      name[matchlen] == '\0' || name[matchlen] == '/')))
  43                        return 1;
  44                if (!fnmatch(match, name, 0))
  45                        return 1;
  46                if (name[namelen-1] != '/')
  47                        continue;
  48
  49                /* We are being asked if the directory ("name") is worth
  50                 * descending into.
  51                 *
  52                 * Find the longest leading directory name that does
  53                 * not have metacharacter in the pathspec; the name
  54                 * we are looking at must overlap with that directory.
  55                 */
  56                for (cp = match, meta = NULL; cp - match < matchlen; cp++) {
  57                        char ch = *cp;
  58                        if (ch == '*' || ch == '[' || ch == '?') {
  59                                meta = cp;
  60                                break;
  61                        }
  62                }
  63                if (!meta)
  64                        meta = cp; /* fully literal */
  65
  66                if (namelen <= meta - match) {
  67                        /* Looking at "Documentation/" and
  68                         * the pattern says "Documentation/howto/", or
  69                         * "Documentation/diff*.txt".  The name we
  70                         * have should match prefix.
  71                         */
  72                        if (!memcmp(match, name, namelen))
  73                                return 1;
  74                        continue;
  75                }
  76
  77                if (meta - match < namelen) {
  78                        /* Looking at "Documentation/howto/" and
  79                         * the pattern says "Documentation/h*";
  80                         * match up to "Do.../h"; this avoids descending
  81                         * into "Documentation/technical/".
  82                         */
  83                        if (!memcmp(match, name, meta - match))
  84                                return 1;
  85                        continue;
  86                }
  87        }
  88        return 0;
  89}
  90
  91static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
  92{
  93        unsigned long size;
  94        char *data;
  95        enum object_type type;
  96        char *to_free = NULL;
  97        int hit;
  98
  99        data = read_sha1_file(sha1, &type, &size);
 100        if (!data) {
 101                error("'%s': unable to read %s", name, sha1_to_hex(sha1));
 102                return 0;
 103        }
 104        if (opt->relative && opt->prefix_length) {
 105                static char name_buf[PATH_MAX];
 106                char *cp;
 107                int name_len = strlen(name) - opt->prefix_length + 1;
 108
 109                if (!tree_name_len)
 110                        name += opt->prefix_length;
 111                else {
 112                        if (ARRAY_SIZE(name_buf) <= name_len)
 113                                cp = to_free = xmalloc(name_len);
 114                        else
 115                                cp = name_buf;
 116                        memcpy(cp, name, tree_name_len);
 117                        strcpy(cp + tree_name_len,
 118                               name + tree_name_len + opt->prefix_length);
 119                        name = cp;
 120                }
 121        }
 122        hit = grep_buffer(opt, name, data, size);
 123        free(data);
 124        free(to_free);
 125        return hit;
 126}
 127
 128static int grep_file(struct grep_opt *opt, const char *filename)
 129{
 130        struct stat st;
 131        int i;
 132        char *data;
 133        size_t sz;
 134
 135        if (lstat(filename, &st) < 0) {
 136        err_ret:
 137                if (errno != ENOENT)
 138                        error("'%s': %s", filename, strerror(errno));
 139                return 0;
 140        }
 141        if (!st.st_size)
 142                return 0; /* empty file -- no grep hit */
 143        if (!S_ISREG(st.st_mode))
 144                return 0;
 145        sz = xsize_t(st.st_size);
 146        i = open(filename, O_RDONLY);
 147        if (i < 0)
 148                goto err_ret;
 149        data = xmalloc(sz + 1);
 150        if (st.st_size != read_in_full(i, data, sz)) {
 151                error("'%s': short read %s", filename, strerror(errno));
 152                close(i);
 153                free(data);
 154                return 0;
 155        }
 156        close(i);
 157        if (opt->relative && opt->prefix_length)
 158                filename += opt->prefix_length;
 159        i = grep_buffer(opt, filename, data, sz);
 160        free(data);
 161        return i;
 162}
 163
 164#if !NO_EXTERNAL_GREP
 165static int exec_grep(int argc, const char **argv)
 166{
 167        pid_t pid;
 168        int status;
 169
 170        argv[argc] = NULL;
 171        pid = fork();
 172        if (pid < 0)
 173                return pid;
 174        if (!pid) {
 175                execvp("grep", (char **) argv);
 176                exit(255);
 177        }
 178        while (waitpid(pid, &status, 0) < 0) {
 179                if (errno == EINTR)
 180                        continue;
 181                return -1;
 182        }
 183        if (WIFEXITED(status)) {
 184                if (!WEXITSTATUS(status))
 185                        return 1;
 186                return 0;
 187        }
 188        return -1;
 189}
 190
 191#define MAXARGS 1000
 192#define ARGBUF 4096
 193#define push_arg(a) do { \
 194        if (nr < MAXARGS) argv[nr++] = (a); \
 195        else die("maximum number of args exceeded"); \
 196        } while (0)
 197
 198/*
 199 * If you send a singleton filename to grep, it does not give
 200 * the name of the file.  GNU grep has "-H" but we would want
 201 * that behaviour in a portable way.
 202 *
 203 * So we keep two pathnames in argv buffer unsent to grep in
 204 * the main loop if we need to do more than one grep.
 205 */
 206static int flush_grep(struct grep_opt *opt,
 207                      int argc, int arg0, const char **argv, int *kept)
 208{
 209        int status;
 210        int count = argc - arg0;
 211        const char *kept_0 = NULL;
 212
 213        if (count <= 2) {
 214                /*
 215                 * Because we keep at least 2 paths in the call from
 216                 * the main loop (i.e. kept != NULL), and MAXARGS is
 217                 * far greater than 2, this usually is a call to
 218                 * conclude the grep.  However, the user could attempt
 219                 * to overflow the argv buffer by giving too many
 220                 * options to leave very small number of real
 221                 * arguments even for the call in the main loop.
 222                 */
 223                if (kept)
 224                        die("insanely many options to grep");
 225
 226                /*
 227                 * If we have two or more paths, we do not have to do
 228                 * anything special, but we need to push /dev/null to
 229                 * get "-H" behaviour of GNU grep portably but when we
 230                 * are not doing "-l" nor "-L" nor "-c".
 231                 */
 232                if (count == 1 &&
 233                    !opt->name_only &&
 234                    !opt->unmatch_name_only &&
 235                    !opt->count) {
 236                        argv[argc++] = "/dev/null";
 237                        argv[argc] = NULL;
 238                }
 239        }
 240
 241        else if (kept) {
 242                /*
 243                 * Called because we found many paths and haven't finished
 244                 * iterating over the cache yet.  We keep two paths
 245                 * for the concluding call.  argv[argc-2] and argv[argc-1]
 246                 * has the last two paths, so save the first one away,
 247                 * replace it with NULL while sending the list to grep,
 248                 * and recover them after we are done.
 249                 */
 250                *kept = 2;
 251                kept_0 = argv[argc-2];
 252                argv[argc-2] = NULL;
 253                argc -= 2;
 254        }
 255
 256        status = exec_grep(argc, argv);
 257
 258        if (kept_0) {
 259                /*
 260                 * Then recover them.  Now the last arg is beyond the
 261                 * terminating NULL which is at argc, and the second
 262                 * from the last is what we saved away in kept_0
 263                 */
 264                argv[arg0++] = kept_0;
 265                argv[arg0] = argv[argc+1];
 266        }
 267        return status;
 268}
 269
 270static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 271{
 272        int i, nr, argc, hit, len, status;
 273        const char *argv[MAXARGS+1];
 274        char randarg[ARGBUF];
 275        char *argptr = randarg;
 276        struct grep_pat *p;
 277
 278        if (opt->extended || (opt->relative && opt->prefix_length))
 279                return -1;
 280        len = nr = 0;
 281        push_arg("grep");
 282        if (opt->fixed)
 283                push_arg("-F");
 284        if (opt->linenum)
 285                push_arg("-n");
 286        if (!opt->pathname)
 287                push_arg("-h");
 288        if (opt->regflags & REG_EXTENDED)
 289                push_arg("-E");
 290        if (opt->regflags & REG_ICASE)
 291                push_arg("-i");
 292        if (opt->word_regexp)
 293                push_arg("-w");
 294        if (opt->name_only)
 295                push_arg("-l");
 296        if (opt->unmatch_name_only)
 297                push_arg("-L");
 298        if (opt->count)
 299                push_arg("-c");
 300        if (opt->post_context || opt->pre_context) {
 301                if (opt->post_context != opt->pre_context) {
 302                        if (opt->pre_context) {
 303                                push_arg("-B");
 304                                len += snprintf(argptr, sizeof(randarg)-len,
 305                                                "%u", opt->pre_context) + 1;
 306                                if (sizeof(randarg) <= len)
 307                                        die("maximum length of args exceeded");
 308                                push_arg(argptr);
 309                                argptr += len;
 310                        }
 311                        if (opt->post_context) {
 312                                push_arg("-A");
 313                                len += snprintf(argptr, sizeof(randarg)-len,
 314                                                "%u", opt->post_context) + 1;
 315                                if (sizeof(randarg) <= len)
 316                                        die("maximum length of args exceeded");
 317                                push_arg(argptr);
 318                                argptr += len;
 319                        }
 320                }
 321                else {
 322                        push_arg("-C");
 323                        len += snprintf(argptr, sizeof(randarg)-len,
 324                                        "%u", opt->post_context) + 1;
 325                        if (sizeof(randarg) <= len)
 326                                die("maximum length of args exceeded");
 327                        push_arg(argptr);
 328                        argptr += len;
 329                }
 330        }
 331        for (p = opt->pattern_list; p; p = p->next) {
 332                push_arg("-e");
 333                push_arg(p->pattern);
 334        }
 335
 336        hit = 0;
 337        argc = nr;
 338        for (i = 0; i < active_nr; i++) {
 339                struct cache_entry *ce = active_cache[i];
 340                char *name;
 341                int kept;
 342                if (!S_ISREG(ce->ce_mode))
 343                        continue;
 344                if (!pathspec_matches(paths, ce->name))
 345                        continue;
 346                name = ce->name;
 347                if (name[0] == '-') {
 348                        int len = ce_namelen(ce);
 349                        name = xmalloc(len + 3);
 350                        memcpy(name, "./", 2);
 351                        memcpy(name + 2, ce->name, len + 1);
 352                }
 353                argv[argc++] = name;
 354                if (MAXARGS <= argc) {
 355                        status = flush_grep(opt, argc, nr, argv, &kept);
 356                        if (0 < status)
 357                                hit = 1;
 358                        argc = nr + kept;
 359                }
 360                if (ce_stage(ce)) {
 361                        do {
 362                                i++;
 363                        } while (i < active_nr &&
 364                                 !strcmp(ce->name, active_cache[i]->name));
 365                        i--; /* compensate for loop control */
 366                }
 367        }
 368        if (argc > nr) {
 369                status = flush_grep(opt, argc, nr, argv, NULL);
 370                if (0 < status)
 371                        hit = 1;
 372        }
 373        return hit;
 374}
 375#endif
 376
 377static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 378{
 379        int hit = 0;
 380        int nr;
 381        read_cache();
 382
 383#if !NO_EXTERNAL_GREP
 384        /*
 385         * Use the external "grep" command for the case where
 386         * we grep through the checked-out files. It tends to
 387         * be a lot more optimized
 388         */
 389        if (!cached) {
 390                hit = external_grep(opt, paths, cached);
 391                if (hit >= 0)
 392                        return hit;
 393        }
 394#endif
 395
 396        for (nr = 0; nr < active_nr; nr++) {
 397                struct cache_entry *ce = active_cache[nr];
 398                if (!S_ISREG(ce->ce_mode))
 399                        continue;
 400                if (!pathspec_matches(paths, ce->name))
 401                        continue;
 402                if (cached) {
 403                        if (ce_stage(ce))
 404                                continue;
 405                        hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 406                }
 407                else
 408                        hit |= grep_file(opt, ce->name);
 409                if (ce_stage(ce)) {
 410                        do {
 411                                nr++;
 412                        } while (nr < active_nr &&
 413                                 !strcmp(ce->name, active_cache[nr]->name));
 414                        nr--; /* compensate for loop control */
 415                }
 416        }
 417        free_grep_patterns(opt);
 418        return hit;
 419}
 420
 421static int grep_tree(struct grep_opt *opt, const char **paths,
 422                     struct tree_desc *tree,
 423                     const char *tree_name, const char *base)
 424{
 425        int len;
 426        int hit = 0;
 427        struct name_entry entry;
 428        char *down;
 429        int tn_len = strlen(tree_name);
 430        struct strbuf pathbuf;
 431
 432        strbuf_init(&pathbuf, PATH_MAX + tn_len);
 433
 434        if (tn_len) {
 435                strbuf_add(&pathbuf, tree_name, tn_len);
 436                strbuf_addch(&pathbuf, ':');
 437                tn_len = pathbuf.len;
 438        }
 439        strbuf_addstr(&pathbuf, base);
 440        len = pathbuf.len;
 441
 442        while (tree_entry(tree, &entry)) {
 443                int te_len = tree_entry_len(entry.path, entry.sha1);
 444                pathbuf.len = len;
 445                strbuf_add(&pathbuf, entry.path, te_len);
 446
 447                if (S_ISDIR(entry.mode))
 448                        /* Match "abc/" against pathspec to
 449                         * decide if we want to descend into "abc"
 450                         * directory.
 451                         */
 452                        strbuf_addch(&pathbuf, '/');
 453
 454                down = pathbuf.buf + tn_len;
 455                if (!pathspec_matches(paths, down))
 456                        ;
 457                else if (S_ISREG(entry.mode))
 458                        hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
 459                else if (S_ISDIR(entry.mode)) {
 460                        enum object_type type;
 461                        struct tree_desc sub;
 462                        void *data;
 463                        unsigned long size;
 464
 465                        data = read_sha1_file(entry.sha1, &type, &size);
 466                        if (!data)
 467                                die("unable to read tree (%s)",
 468                                    sha1_to_hex(entry.sha1));
 469                        init_tree_desc(&sub, data, size);
 470                        hit |= grep_tree(opt, paths, &sub, tree_name, down);
 471                        free(data);
 472                }
 473        }
 474        strbuf_release(&pathbuf);
 475        return hit;
 476}
 477
 478static int grep_object(struct grep_opt *opt, const char **paths,
 479                       struct object *obj, const char *name)
 480{
 481        if (obj->type == OBJ_BLOB)
 482                return grep_sha1(opt, obj->sha1, name, 0);
 483        if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 484                struct tree_desc tree;
 485                void *data;
 486                unsigned long size;
 487                int hit;
 488                data = read_object_with_reference(obj->sha1, tree_type,
 489                                                  &size, NULL);
 490                if (!data)
 491                        die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 492                init_tree_desc(&tree, data, size);
 493                hit = grep_tree(opt, paths, &tree, name, "");
 494                free(data);
 495                return hit;
 496        }
 497        die("unable to grep from object of type %s", typename(obj->type));
 498}
 499
 500static const char builtin_grep_usage[] =
 501"git grep <option>* [-e] <pattern> <rev>* [[--] <path>...]";
 502
 503static const char emsg_invalid_context_len[] =
 504"%s: invalid context length argument";
 505static const char emsg_missing_context_len[] =
 506"missing context length argument";
 507static const char emsg_missing_argument[] =
 508"option requires an argument -%s";
 509
 510int cmd_grep(int argc, const char **argv, const char *prefix)
 511{
 512        int hit = 0;
 513        int cached = 0;
 514        int seen_dashdash = 0;
 515        struct grep_opt opt;
 516        struct object_array list = { 0, 0, NULL };
 517        const char **paths = NULL;
 518        int i;
 519
 520        memset(&opt, 0, sizeof(opt));
 521        opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 522        opt.relative = 1;
 523        opt.pathname = 1;
 524        opt.pattern_tail = &opt.pattern_list;
 525        opt.regflags = REG_NEWLINE;
 526
 527        /*
 528         * If there is no -- then the paths must exist in the working
 529         * tree.  If there is no explicit pattern specified with -e or
 530         * -f, we take the first unrecognized non option to be the
 531         * pattern, but then what follows it must be zero or more
 532         * valid refs up to the -- (if exists), and then existing
 533         * paths.  If there is an explicit pattern, then the first
 534         * unrecognized non option is the beginning of the refs list
 535         * that continues up to the -- (if exists), and then paths.
 536         */
 537
 538        while (1 < argc) {
 539                const char *arg = argv[1];
 540                argc--; argv++;
 541                if (!strcmp("--cached", arg)) {
 542                        cached = 1;
 543                        continue;
 544                }
 545                if (!strcmp("-a", arg) ||
 546                    !strcmp("--text", arg)) {
 547                        opt.binary = GREP_BINARY_TEXT;
 548                        continue;
 549                }
 550                if (!strcmp("-i", arg) ||
 551                    !strcmp("--ignore-case", arg)) {
 552                        opt.regflags |= REG_ICASE;
 553                        continue;
 554                }
 555                if (!strcmp("-I", arg)) {
 556                        opt.binary = GREP_BINARY_NOMATCH;
 557                        continue;
 558                }
 559                if (!strcmp("-v", arg) ||
 560                    !strcmp("--invert-match", arg)) {
 561                        opt.invert = 1;
 562                        continue;
 563                }
 564                if (!strcmp("-E", arg) ||
 565                    !strcmp("--extended-regexp", arg)) {
 566                        opt.regflags |= REG_EXTENDED;
 567                        continue;
 568                }
 569                if (!strcmp("-F", arg) ||
 570                    !strcmp("--fixed-strings", arg)) {
 571                        opt.fixed = 1;
 572                        continue;
 573                }
 574                if (!strcmp("-G", arg) ||
 575                    !strcmp("--basic-regexp", arg)) {
 576                        opt.regflags &= ~REG_EXTENDED;
 577                        continue;
 578                }
 579                if (!strcmp("-n", arg)) {
 580                        opt.linenum = 1;
 581                        continue;
 582                }
 583                if (!strcmp("-h", arg)) {
 584                        opt.pathname = 0;
 585                        continue;
 586                }
 587                if (!strcmp("-H", arg)) {
 588                        opt.pathname = 1;
 589                        continue;
 590                }
 591                if (!strcmp("-l", arg) ||
 592                    !strcmp("--name-only", arg) ||
 593                    !strcmp("--files-with-matches", arg)) {
 594                        opt.name_only = 1;
 595                        continue;
 596                }
 597                if (!strcmp("-L", arg) ||
 598                    !strcmp("--files-without-match", arg)) {
 599                        opt.unmatch_name_only = 1;
 600                        continue;
 601                }
 602                if (!strcmp("-c", arg) ||
 603                    !strcmp("--count", arg)) {
 604                        opt.count = 1;
 605                        continue;
 606                }
 607                if (!strcmp("-w", arg) ||
 608                    !strcmp("--word-regexp", arg)) {
 609                        opt.word_regexp = 1;
 610                        continue;
 611                }
 612                if (!prefixcmp(arg, "-A") ||
 613                    !prefixcmp(arg, "-B") ||
 614                    !prefixcmp(arg, "-C") ||
 615                    (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
 616                        unsigned num;
 617                        const char *scan;
 618                        switch (arg[1]) {
 619                        case 'A': case 'B': case 'C':
 620                                if (!arg[2]) {
 621                                        if (argc <= 1)
 622                                                die(emsg_missing_context_len);
 623                                        scan = *++argv;
 624                                        argc--;
 625                                }
 626                                else
 627                                        scan = arg + 2;
 628                                break;
 629                        default:
 630                                scan = arg + 1;
 631                                break;
 632                        }
 633                        if (strtoul_ui(scan, 10, &num))
 634                                die(emsg_invalid_context_len, scan);
 635                        switch (arg[1]) {
 636                        case 'A':
 637                                opt.post_context = num;
 638                                break;
 639                        default:
 640                        case 'C':
 641                                opt.post_context = num;
 642                        case 'B':
 643                                opt.pre_context = num;
 644                                break;
 645                        }
 646                        continue;
 647                }
 648                if (!strcmp("-f", arg)) {
 649                        FILE *patterns;
 650                        int lno = 0;
 651                        char buf[1024];
 652                        if (argc <= 1)
 653                                die(emsg_missing_argument, arg);
 654                        patterns = fopen(argv[1], "r");
 655                        if (!patterns)
 656                                die("'%s': %s", argv[1], strerror(errno));
 657                        while (fgets(buf, sizeof(buf), patterns)) {
 658                                int len = strlen(buf);
 659                                if (len && buf[len-1] == '\n')
 660                                        buf[len-1] = 0;
 661                                /* ignore empty line like grep does */
 662                                if (!buf[0])
 663                                        continue;
 664                                append_grep_pattern(&opt, xstrdup(buf),
 665                                                    argv[1], ++lno,
 666                                                    GREP_PATTERN);
 667                        }
 668                        fclose(patterns);
 669                        argv++;
 670                        argc--;
 671                        continue;
 672                }
 673                if (!strcmp("--not", arg)) {
 674                        append_grep_pattern(&opt, arg, "command line", 0,
 675                                            GREP_NOT);
 676                        continue;
 677                }
 678                if (!strcmp("--and", arg)) {
 679                        append_grep_pattern(&opt, arg, "command line", 0,
 680                                            GREP_AND);
 681                        continue;
 682                }
 683                if (!strcmp("--or", arg))
 684                        continue; /* no-op */
 685                if (!strcmp("(", arg)) {
 686                        append_grep_pattern(&opt, arg, "command line", 0,
 687                                            GREP_OPEN_PAREN);
 688                        continue;
 689                }
 690                if (!strcmp(")", arg)) {
 691                        append_grep_pattern(&opt, arg, "command line", 0,
 692                                            GREP_CLOSE_PAREN);
 693                        continue;
 694                }
 695                if (!strcmp("--all-match", arg)) {
 696                        opt.all_match = 1;
 697                        continue;
 698                }
 699                if (!strcmp("-e", arg)) {
 700                        if (1 < argc) {
 701                                append_grep_pattern(&opt, argv[1],
 702                                                    "-e option", 0,
 703                                                    GREP_PATTERN);
 704                                argv++;
 705                                argc--;
 706                                continue;
 707                        }
 708                        die(emsg_missing_argument, arg);
 709                }
 710                if (!strcmp("--full-name", arg)) {
 711                        opt.relative = 0;
 712                        continue;
 713                }
 714                if (!strcmp("--", arg)) {
 715                        /* later processing wants to have this at argv[1] */
 716                        argv--;
 717                        argc++;
 718                        break;
 719                }
 720                if (*arg == '-')
 721                        usage(builtin_grep_usage);
 722
 723                /* First unrecognized non-option token */
 724                if (!opt.pattern_list) {
 725                        append_grep_pattern(&opt, arg, "command line", 0,
 726                                            GREP_PATTERN);
 727                        break;
 728                }
 729                else {
 730                        /* We are looking at the first path or rev;
 731                         * it is found at argv[1] after leaving the
 732                         * loop.
 733                         */
 734                        argc++; argv--;
 735                        break;
 736                }
 737        }
 738
 739        if (!opt.pattern_list)
 740                die("no pattern given.");
 741        if ((opt.regflags != REG_NEWLINE) && opt.fixed)
 742                die("cannot mix --fixed-strings and regexp");
 743        compile_grep_patterns(&opt);
 744
 745        /* Check revs and then paths */
 746        for (i = 1; i < argc; i++) {
 747                const char *arg = argv[i];
 748                unsigned char sha1[20];
 749                /* Is it a rev? */
 750                if (!get_sha1(arg, sha1)) {
 751                        struct object *object = parse_object(sha1);
 752                        if (!object)
 753                                die("bad object %s", arg);
 754                        add_object_array(object, arg, &list);
 755                        continue;
 756                }
 757                if (!strcmp(arg, "--")) {
 758                        i++;
 759                        seen_dashdash = 1;
 760                }
 761                break;
 762        }
 763
 764        /* The rest are paths */
 765        if (!seen_dashdash) {
 766                int j;
 767                for (j = i; j < argc; j++)
 768                        verify_filename(prefix, argv[j]);
 769        }
 770
 771        if (i < argc) {
 772                paths = get_pathspec(prefix, argv + i);
 773                if (opt.prefix_length && opt.relative) {
 774                        /* Make sure we do not get outside of paths */
 775                        for (i = 0; paths[i]; i++)
 776                                if (strncmp(prefix, paths[i], opt.prefix_length))
 777                                        die("git grep: cannot generate relative filenames containing '..'");
 778                }
 779        }
 780        else if (prefix) {
 781                paths = xcalloc(2, sizeof(const char *));
 782                paths[0] = prefix;
 783                paths[1] = NULL;
 784        }
 785
 786        if (!list.nr) {
 787                if (!cached)
 788                        setup_work_tree();
 789                return !grep_cache(&opt, paths, cached);
 790        }
 791
 792        if (cached)
 793                die("both --cached and trees are given.");
 794
 795        for (i = 0; i < list.nr; i++) {
 796                struct object *real_obj;
 797                real_obj = deref_tag(list.objects[i].item, NULL, 0);
 798                if (grep_object(&opt, paths, real_obj, list.objects[i].name))
 799                        hit = 1;
 800        }
 801        free_grep_patterns(&opt);
 802        return !hit;
 803}