builtin-grep.con commit add tests for git diff --submodule (86140d5)
   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 "parse-options.h"
  14#include "userdiff.h"
  15#include "grep.h"
  16#include "quote.h"
  17
  18#ifndef NO_EXTERNAL_GREP
  19#ifdef __unix__
  20#define NO_EXTERNAL_GREP 0
  21#else
  22#define NO_EXTERNAL_GREP 1
  23#endif
  24#endif
  25
  26static char const * const grep_usage[] = {
  27        "git grep [options] [-e] <pattern> [<rev>...] [[--] path...]",
  28        NULL
  29};
  30
  31static int grep_config(const char *var, const char *value, void *cb)
  32{
  33        struct grep_opt *opt = cb;
  34
  35        switch (userdiff_config(var, value)) {
  36        case 0: break;
  37        case -1: return -1;
  38        default: return 0;
  39        }
  40
  41        if (!strcmp(var, "color.grep")) {
  42                opt->color = git_config_colorbool(var, value, -1);
  43                return 0;
  44        }
  45        if (!strcmp(var, "color.grep.external"))
  46                return git_config_string(&(opt->color_external), var, value);
  47        if (!strcmp(var, "color.grep.match")) {
  48                if (!value)
  49                        return config_error_nonbool(var);
  50                color_parse(value, var, opt->color_match);
  51                return 0;
  52        }
  53        return git_color_default_config(var, value, cb);
  54}
  55
  56/*
  57 * Return non-zero if max_depth is negative or path has no more then max_depth
  58 * slashes.
  59 */
  60static int accept_subdir(const char *path, int max_depth)
  61{
  62        if (max_depth < 0)
  63                return 1;
  64
  65        while ((path = strchr(path, '/')) != NULL) {
  66                max_depth--;
  67                if (max_depth < 0)
  68                        return 0;
  69                path++;
  70        }
  71        return 1;
  72}
  73
  74/*
  75 * Return non-zero if name is a subdirectory of match and is not too deep.
  76 */
  77static int is_subdir(const char *name, int namelen,
  78                const char *match, int matchlen, int max_depth)
  79{
  80        if (matchlen > namelen || strncmp(name, match, matchlen))
  81                return 0;
  82
  83        if (name[matchlen] == '\0') /* exact match */
  84                return 1;
  85
  86        if (!matchlen || match[matchlen-1] == '/' || name[matchlen] == '/')
  87                return accept_subdir(name + matchlen + 1, max_depth);
  88
  89        return 0;
  90}
  91
  92/*
  93 * git grep pathspecs are somewhat different from diff-tree pathspecs;
  94 * pathname wildcards are allowed.
  95 */
  96static int pathspec_matches(const char **paths, const char *name, int max_depth)
  97{
  98        int namelen, i;
  99        if (!paths || !*paths)
 100                return accept_subdir(name, max_depth);
 101        namelen = strlen(name);
 102        for (i = 0; paths[i]; i++) {
 103                const char *match = paths[i];
 104                int matchlen = strlen(match);
 105                const char *cp, *meta;
 106
 107                if (is_subdir(name, namelen, match, matchlen, max_depth))
 108                        return 1;
 109                if (!fnmatch(match, name, 0))
 110                        return 1;
 111                if (name[namelen-1] != '/')
 112                        continue;
 113
 114                /* We are being asked if the directory ("name") is worth
 115                 * descending into.
 116                 *
 117                 * Find the longest leading directory name that does
 118                 * not have metacharacter in the pathspec; the name
 119                 * we are looking at must overlap with that directory.
 120                 */
 121                for (cp = match, meta = NULL; cp - match < matchlen; cp++) {
 122                        char ch = *cp;
 123                        if (ch == '*' || ch == '[' || ch == '?') {
 124                                meta = cp;
 125                                break;
 126                        }
 127                }
 128                if (!meta)
 129                        meta = cp; /* fully literal */
 130
 131                if (namelen <= meta - match) {
 132                        /* Looking at "Documentation/" and
 133                         * the pattern says "Documentation/howto/", or
 134                         * "Documentation/diff*.txt".  The name we
 135                         * have should match prefix.
 136                         */
 137                        if (!memcmp(match, name, namelen))
 138                                return 1;
 139                        continue;
 140                }
 141
 142                if (meta - match < namelen) {
 143                        /* Looking at "Documentation/howto/" and
 144                         * the pattern says "Documentation/h*";
 145                         * match up to "Do.../h"; this avoids descending
 146                         * into "Documentation/technical/".
 147                         */
 148                        if (!memcmp(match, name, meta - match))
 149                                return 1;
 150                        continue;
 151                }
 152        }
 153        return 0;
 154}
 155
 156static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
 157{
 158        unsigned long size;
 159        char *data;
 160        enum object_type type;
 161        int hit;
 162        struct strbuf pathbuf = STRBUF_INIT;
 163
 164        data = read_sha1_file(sha1, &type, &size);
 165        if (!data) {
 166                error("'%s': unable to read %s", name, sha1_to_hex(sha1));
 167                return 0;
 168        }
 169        if (opt->relative && opt->prefix_length) {
 170                quote_path_relative(name + tree_name_len, -1, &pathbuf, opt->prefix);
 171                strbuf_insert(&pathbuf, 0, name, tree_name_len);
 172                name = pathbuf.buf;
 173        }
 174        hit = grep_buffer(opt, name, data, size);
 175        strbuf_release(&pathbuf);
 176        free(data);
 177        return hit;
 178}
 179
 180static int grep_file(struct grep_opt *opt, const char *filename)
 181{
 182        struct stat st;
 183        int i;
 184        char *data;
 185        size_t sz;
 186        struct strbuf buf = STRBUF_INIT;
 187
 188        if (lstat(filename, &st) < 0) {
 189        err_ret:
 190                if (errno != ENOENT)
 191                        error("'%s': %s", filename, strerror(errno));
 192                return 0;
 193        }
 194        if (!st.st_size)
 195                return 0; /* empty file -- no grep hit */
 196        if (!S_ISREG(st.st_mode))
 197                return 0;
 198        sz = xsize_t(st.st_size);
 199        i = open(filename, O_RDONLY);
 200        if (i < 0)
 201                goto err_ret;
 202        data = xmalloc(sz + 1);
 203        if (st.st_size != read_in_full(i, data, sz)) {
 204                error("'%s': short read %s", filename, strerror(errno));
 205                close(i);
 206                free(data);
 207                return 0;
 208        }
 209        close(i);
 210        if (opt->relative && opt->prefix_length)
 211                filename = quote_path_relative(filename, -1, &buf, opt->prefix);
 212        i = grep_buffer(opt, filename, data, sz);
 213        strbuf_release(&buf);
 214        free(data);
 215        return i;
 216}
 217
 218#if !NO_EXTERNAL_GREP
 219static int exec_grep(int argc, const char **argv)
 220{
 221        pid_t pid;
 222        int status;
 223
 224        argv[argc] = NULL;
 225        pid = fork();
 226        if (pid < 0)
 227                return pid;
 228        if (!pid) {
 229                execvp("grep", (char **) argv);
 230                exit(255);
 231        }
 232        while (waitpid(pid, &status, 0) < 0) {
 233                if (errno == EINTR)
 234                        continue;
 235                return -1;
 236        }
 237        if (WIFEXITED(status)) {
 238                if (!WEXITSTATUS(status))
 239                        return 1;
 240                return 0;
 241        }
 242        return -1;
 243}
 244
 245#define MAXARGS 1000
 246#define ARGBUF 4096
 247#define push_arg(a) do { \
 248        if (nr < MAXARGS) argv[nr++] = (a); \
 249        else die("maximum number of args exceeded"); \
 250        } while (0)
 251
 252/*
 253 * If you send a singleton filename to grep, it does not give
 254 * the name of the file.  GNU grep has "-H" but we would want
 255 * that behaviour in a portable way.
 256 *
 257 * So we keep two pathnames in argv buffer unsent to grep in
 258 * the main loop if we need to do more than one grep.
 259 */
 260static int flush_grep(struct grep_opt *opt,
 261                      int argc, int arg0, const char **argv, int *kept)
 262{
 263        int status;
 264        int count = argc - arg0;
 265        const char *kept_0 = NULL;
 266
 267        if (count <= 2) {
 268                /*
 269                 * Because we keep at least 2 paths in the call from
 270                 * the main loop (i.e. kept != NULL), and MAXARGS is
 271                 * far greater than 2, this usually is a call to
 272                 * conclude the grep.  However, the user could attempt
 273                 * to overflow the argv buffer by giving too many
 274                 * options to leave very small number of real
 275                 * arguments even for the call in the main loop.
 276                 */
 277                if (kept)
 278                        die("insanely many options to grep");
 279
 280                /*
 281                 * If we have two or more paths, we do not have to do
 282                 * anything special, but we need to push /dev/null to
 283                 * get "-H" behaviour of GNU grep portably but when we
 284                 * are not doing "-l" nor "-L" nor "-c".
 285                 */
 286                if (count == 1 &&
 287                    !opt->name_only &&
 288                    !opt->unmatch_name_only &&
 289                    !opt->count) {
 290                        argv[argc++] = "/dev/null";
 291                        argv[argc] = NULL;
 292                }
 293        }
 294
 295        else if (kept) {
 296                /*
 297                 * Called because we found many paths and haven't finished
 298                 * iterating over the cache yet.  We keep two paths
 299                 * for the concluding call.  argv[argc-2] and argv[argc-1]
 300                 * has the last two paths, so save the first one away,
 301                 * replace it with NULL while sending the list to grep,
 302                 * and recover them after we are done.
 303                 */
 304                *kept = 2;
 305                kept_0 = argv[argc-2];
 306                argv[argc-2] = NULL;
 307                argc -= 2;
 308        }
 309
 310        if (opt->pre_context || opt->post_context) {
 311                /*
 312                 * grep handles hunk marks between files, but we need to
 313                 * do that ourselves between multiple calls.
 314                 */
 315                if (opt->show_hunk_mark)
 316                        write_or_die(1, "--\n", 3);
 317                else
 318                        opt->show_hunk_mark = 1;
 319        }
 320
 321        status = exec_grep(argc, argv);
 322
 323        if (kept_0) {
 324                /*
 325                 * Then recover them.  Now the last arg is beyond the
 326                 * terminating NULL which is at argc, and the second
 327                 * from the last is what we saved away in kept_0
 328                 */
 329                argv[arg0++] = kept_0;
 330                argv[arg0] = argv[argc+1];
 331        }
 332        return status;
 333}
 334
 335static void grep_add_color(struct strbuf *sb, const char *escape_seq)
 336{
 337        size_t orig_len = sb->len;
 338
 339        while (*escape_seq) {
 340                if (*escape_seq == 'm')
 341                        strbuf_addch(sb, ';');
 342                else if (*escape_seq != '\033' && *escape_seq  != '[')
 343                        strbuf_addch(sb, *escape_seq);
 344                escape_seq++;
 345        }
 346        if (sb->len > orig_len && sb->buf[sb->len - 1] == ';')
 347                strbuf_setlen(sb, sb->len - 1);
 348}
 349
 350static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 351{
 352        int i, nr, argc, hit, len, status;
 353        const char *argv[MAXARGS+1];
 354        char randarg[ARGBUF];
 355        char *argptr = randarg;
 356        struct grep_pat *p;
 357
 358        if (opt->extended || (opt->relative && opt->prefix_length))
 359                return -1;
 360        len = nr = 0;
 361        push_arg("grep");
 362        if (opt->fixed)
 363                push_arg("-F");
 364        if (opt->linenum)
 365                push_arg("-n");
 366        if (!opt->pathname)
 367                push_arg("-h");
 368        if (opt->regflags & REG_EXTENDED)
 369                push_arg("-E");
 370        if (opt->regflags & REG_ICASE)
 371                push_arg("-i");
 372        if (opt->binary == GREP_BINARY_NOMATCH)
 373                push_arg("-I");
 374        if (opt->word_regexp)
 375                push_arg("-w");
 376        if (opt->name_only)
 377                push_arg("-l");
 378        if (opt->unmatch_name_only)
 379                push_arg("-L");
 380        if (opt->null_following_name)
 381                /* in GNU grep git's "-z" translates to "-Z" */
 382                push_arg("-Z");
 383        if (opt->count)
 384                push_arg("-c");
 385        if (opt->post_context || opt->pre_context) {
 386                if (opt->post_context != opt->pre_context) {
 387                        if (opt->pre_context) {
 388                                push_arg("-B");
 389                                len += snprintf(argptr, sizeof(randarg)-len,
 390                                                "%u", opt->pre_context) + 1;
 391                                if (sizeof(randarg) <= len)
 392                                        die("maximum length of args exceeded");
 393                                push_arg(argptr);
 394                                argptr += len;
 395                        }
 396                        if (opt->post_context) {
 397                                push_arg("-A");
 398                                len += snprintf(argptr, sizeof(randarg)-len,
 399                                                "%u", opt->post_context) + 1;
 400                                if (sizeof(randarg) <= len)
 401                                        die("maximum length of args exceeded");
 402                                push_arg(argptr);
 403                                argptr += len;
 404                        }
 405                }
 406                else {
 407                        push_arg("-C");
 408                        len += snprintf(argptr, sizeof(randarg)-len,
 409                                        "%u", opt->post_context) + 1;
 410                        if (sizeof(randarg) <= len)
 411                                die("maximum length of args exceeded");
 412                        push_arg(argptr);
 413                        argptr += len;
 414                }
 415        }
 416        for (p = opt->pattern_list; p; p = p->next) {
 417                push_arg("-e");
 418                push_arg(p->pattern);
 419        }
 420        if (opt->color) {
 421                struct strbuf sb = STRBUF_INIT;
 422
 423                grep_add_color(&sb, opt->color_match);
 424                setenv("GREP_COLOR", sb.buf, 1);
 425
 426                strbuf_reset(&sb);
 427                strbuf_addstr(&sb, "mt=");
 428                grep_add_color(&sb, opt->color_match);
 429                strbuf_addstr(&sb, ":sl=:cx=:fn=:ln=:bn=:se=");
 430                setenv("GREP_COLORS", sb.buf, 1);
 431
 432                strbuf_release(&sb);
 433
 434                if (opt->color_external && strlen(opt->color_external) > 0)
 435                        push_arg(opt->color_external);
 436        }
 437
 438        hit = 0;
 439        argc = nr;
 440        for (i = 0; i < active_nr; i++) {
 441                struct cache_entry *ce = active_cache[i];
 442                char *name;
 443                int kept;
 444                if (!S_ISREG(ce->ce_mode))
 445                        continue;
 446                if (!pathspec_matches(paths, ce->name, opt->max_depth))
 447                        continue;
 448                name = ce->name;
 449                if (name[0] == '-') {
 450                        int len = ce_namelen(ce);
 451                        name = xmalloc(len + 3);
 452                        memcpy(name, "./", 2);
 453                        memcpy(name + 2, ce->name, len + 1);
 454                }
 455                argv[argc++] = name;
 456                if (MAXARGS <= argc) {
 457                        status = flush_grep(opt, argc, nr, argv, &kept);
 458                        if (0 < status)
 459                                hit = 1;
 460                        argc = nr + kept;
 461                }
 462                if (ce_stage(ce)) {
 463                        do {
 464                                i++;
 465                        } while (i < active_nr &&
 466                                 !strcmp(ce->name, active_cache[i]->name));
 467                        i--; /* compensate for loop control */
 468                }
 469        }
 470        if (argc > nr) {
 471                status = flush_grep(opt, argc, nr, argv, NULL);
 472                if (0 < status)
 473                        hit = 1;
 474        }
 475        return hit;
 476}
 477#endif
 478
 479static int grep_cache(struct grep_opt *opt, const char **paths, int cached,
 480                      int external_grep_allowed)
 481{
 482        int hit = 0;
 483        int nr;
 484        read_cache();
 485
 486#if !NO_EXTERNAL_GREP
 487        /*
 488         * Use the external "grep" command for the case where
 489         * we grep through the checked-out files. It tends to
 490         * be a lot more optimized
 491         */
 492        if (!cached && external_grep_allowed) {
 493                hit = external_grep(opt, paths, cached);
 494                if (hit >= 0)
 495                        return hit;
 496                hit = 0;
 497        }
 498#endif
 499
 500        for (nr = 0; nr < active_nr; nr++) {
 501                struct cache_entry *ce = active_cache[nr];
 502                if (!S_ISREG(ce->ce_mode))
 503                        continue;
 504                if (!pathspec_matches(paths, ce->name, opt->max_depth))
 505                        continue;
 506                /*
 507                 * If CE_VALID is on, we assume worktree file and its cache entry
 508                 * are identical, even if worktree file has been modified, so use
 509                 * cache version instead
 510                 */
 511                if (cached || (ce->ce_flags & CE_VALID)) {
 512                        if (ce_stage(ce))
 513                                continue;
 514                        hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 515                }
 516                else
 517                        hit |= grep_file(opt, ce->name);
 518                if (ce_stage(ce)) {
 519                        do {
 520                                nr++;
 521                        } while (nr < active_nr &&
 522                                 !strcmp(ce->name, active_cache[nr]->name));
 523                        nr--; /* compensate for loop control */
 524                }
 525        }
 526        free_grep_patterns(opt);
 527        return hit;
 528}
 529
 530static int grep_tree(struct grep_opt *opt, const char **paths,
 531                     struct tree_desc *tree,
 532                     const char *tree_name, const char *base)
 533{
 534        int len;
 535        int hit = 0;
 536        struct name_entry entry;
 537        char *down;
 538        int tn_len = strlen(tree_name);
 539        struct strbuf pathbuf;
 540
 541        strbuf_init(&pathbuf, PATH_MAX + tn_len);
 542
 543        if (tn_len) {
 544                strbuf_add(&pathbuf, tree_name, tn_len);
 545                strbuf_addch(&pathbuf, ':');
 546                tn_len = pathbuf.len;
 547        }
 548        strbuf_addstr(&pathbuf, base);
 549        len = pathbuf.len;
 550
 551        while (tree_entry(tree, &entry)) {
 552                int te_len = tree_entry_len(entry.path, entry.sha1);
 553                pathbuf.len = len;
 554                strbuf_add(&pathbuf, entry.path, te_len);
 555
 556                if (S_ISDIR(entry.mode))
 557                        /* Match "abc/" against pathspec to
 558                         * decide if we want to descend into "abc"
 559                         * directory.
 560                         */
 561                        strbuf_addch(&pathbuf, '/');
 562
 563                down = pathbuf.buf + tn_len;
 564                if (!pathspec_matches(paths, down, opt->max_depth))
 565                        ;
 566                else if (S_ISREG(entry.mode))
 567                        hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
 568                else if (S_ISDIR(entry.mode)) {
 569                        enum object_type type;
 570                        struct tree_desc sub;
 571                        void *data;
 572                        unsigned long size;
 573
 574                        data = read_sha1_file(entry.sha1, &type, &size);
 575                        if (!data)
 576                                die("unable to read tree (%s)",
 577                                    sha1_to_hex(entry.sha1));
 578                        init_tree_desc(&sub, data, size);
 579                        hit |= grep_tree(opt, paths, &sub, tree_name, down);
 580                        free(data);
 581                }
 582        }
 583        strbuf_release(&pathbuf);
 584        return hit;
 585}
 586
 587static int grep_object(struct grep_opt *opt, const char **paths,
 588                       struct object *obj, const char *name)
 589{
 590        if (obj->type == OBJ_BLOB)
 591                return grep_sha1(opt, obj->sha1, name, 0);
 592        if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 593                struct tree_desc tree;
 594                void *data;
 595                unsigned long size;
 596                int hit;
 597                data = read_object_with_reference(obj->sha1, tree_type,
 598                                                  &size, NULL);
 599                if (!data)
 600                        die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 601                init_tree_desc(&tree, data, size);
 602                hit = grep_tree(opt, paths, &tree, name, "");
 603                free(data);
 604                return hit;
 605        }
 606        die("unable to grep from object of type %s", typename(obj->type));
 607}
 608
 609static int context_callback(const struct option *opt, const char *arg,
 610                            int unset)
 611{
 612        struct grep_opt *grep_opt = opt->value;
 613        int value;
 614        const char *endp;
 615
 616        if (unset) {
 617                grep_opt->pre_context = grep_opt->post_context = 0;
 618                return 0;
 619        }
 620        value = strtol(arg, (char **)&endp, 10);
 621        if (*endp) {
 622                return error("switch `%c' expects a numerical value",
 623                             opt->short_name);
 624        }
 625        grep_opt->pre_context = grep_opt->post_context = value;
 626        return 0;
 627}
 628
 629static int file_callback(const struct option *opt, const char *arg, int unset)
 630{
 631        struct grep_opt *grep_opt = opt->value;
 632        FILE *patterns;
 633        int lno = 0;
 634        struct strbuf sb;
 635
 636        patterns = fopen(arg, "r");
 637        if (!patterns)
 638                die_errno("cannot open '%s'", arg);
 639        while (strbuf_getline(&sb, patterns, '\n') == 0) {
 640                /* ignore empty line like grep does */
 641                if (sb.len == 0)
 642                        continue;
 643                append_grep_pattern(grep_opt, strbuf_detach(&sb, NULL), arg,
 644                                    ++lno, GREP_PATTERN);
 645        }
 646        fclose(patterns);
 647        strbuf_release(&sb);
 648        return 0;
 649}
 650
 651static int not_callback(const struct option *opt, const char *arg, int unset)
 652{
 653        struct grep_opt *grep_opt = opt->value;
 654        append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 655        return 0;
 656}
 657
 658static int and_callback(const struct option *opt, const char *arg, int unset)
 659{
 660        struct grep_opt *grep_opt = opt->value;
 661        append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 662        return 0;
 663}
 664
 665static int open_callback(const struct option *opt, const char *arg, int unset)
 666{
 667        struct grep_opt *grep_opt = opt->value;
 668        append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 669        return 0;
 670}
 671
 672static int close_callback(const struct option *opt, const char *arg, int unset)
 673{
 674        struct grep_opt *grep_opt = opt->value;
 675        append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 676        return 0;
 677}
 678
 679static int pattern_callback(const struct option *opt, const char *arg,
 680                            int unset)
 681{
 682        struct grep_opt *grep_opt = opt->value;
 683        append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 684        return 0;
 685}
 686
 687static int help_callback(const struct option *opt, const char *arg, int unset)
 688{
 689        return -1;
 690}
 691
 692int cmd_grep(int argc, const char **argv, const char *prefix)
 693{
 694        int hit = 0;
 695        int cached = 0;
 696        int external_grep_allowed = 1;
 697        int seen_dashdash = 0;
 698        struct grep_opt opt;
 699        struct object_array list = { 0, 0, NULL };
 700        const char **paths = NULL;
 701        int i;
 702        int dummy;
 703        struct option options[] = {
 704                OPT_BOOLEAN(0, "cached", &cached,
 705                        "search in index instead of in the work tree"),
 706                OPT_GROUP(""),
 707                OPT_BOOLEAN('v', "invert-match", &opt.invert,
 708                        "show non-matching lines"),
 709                OPT_BIT('i', "ignore-case", &opt.regflags,
 710                        "case insensitive matching", REG_ICASE),
 711                OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 712                        "match patterns only at word boundaries"),
 713                OPT_SET_INT('a', "text", &opt.binary,
 714                        "process binary files as text", GREP_BINARY_TEXT),
 715                OPT_SET_INT('I', NULL, &opt.binary,
 716                        "don't match patterns in binary files",
 717                        GREP_BINARY_NOMATCH),
 718                { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
 719                        "descend at most <depth> levels", PARSE_OPT_NONEG,
 720                        NULL, 1 },
 721                OPT_GROUP(""),
 722                OPT_BIT('E', "extended-regexp", &opt.regflags,
 723                        "use extended POSIX regular expressions", REG_EXTENDED),
 724                OPT_NEGBIT('G', "basic-regexp", &opt.regflags,
 725                        "use basic POSIX regular expressions (default)",
 726                        REG_EXTENDED),
 727                OPT_BOOLEAN('F', "fixed-strings", &opt.fixed,
 728                        "interpret patterns as fixed strings"),
 729                OPT_GROUP(""),
 730                OPT_BOOLEAN('n', NULL, &opt.linenum, "show line numbers"),
 731                OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 732                OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 733                OPT_NEGBIT(0, "full-name", &opt.relative,
 734                        "show filenames relative to top directory", 1),
 735                OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 736                        "show only filenames instead of matching lines"),
 737                OPT_BOOLEAN(0, "name-only", &opt.name_only,
 738                        "synonym for --files-with-matches"),
 739                OPT_BOOLEAN('L', "files-without-match",
 740                        &opt.unmatch_name_only,
 741                        "show only the names of files without match"),
 742                OPT_BOOLEAN('z', "null", &opt.null_following_name,
 743                        "print NUL after filenames"),
 744                OPT_BOOLEAN('c', "count", &opt.count,
 745                        "show the number of matches instead of matching lines"),
 746                OPT_SET_INT(0, "color", &opt.color, "highlight matches", 1),
 747                OPT_GROUP(""),
 748                OPT_CALLBACK('C', NULL, &opt, "n",
 749                        "show <n> context lines before and after matches",
 750                        context_callback),
 751                OPT_INTEGER('B', NULL, &opt.pre_context,
 752                        "show <n> context lines before matches"),
 753                OPT_INTEGER('A', NULL, &opt.post_context,
 754                        "show <n> context lines after matches"),
 755                OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 756                        context_callback),
 757                OPT_BOOLEAN('p', "show-function", &opt.funcname,
 758                        "show a line with the function name before matches"),
 759                OPT_GROUP(""),
 760                OPT_CALLBACK('f', NULL, &opt, "file",
 761                        "read patterns from file", file_callback),
 762                { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 763                        "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 764                { OPTION_CALLBACK, 0, "and", &opt, NULL,
 765                  "combine patterns specified with -e",
 766                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 767                OPT_BOOLEAN(0, "or", &dummy, ""),
 768                { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 769                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 770                { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 771                  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 772                  open_callback },
 773                { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 774                  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 775                  close_callback },
 776                OPT_BOOLEAN(0, "all-match", &opt.all_match,
 777                        "show only matches from files that match all patterns"),
 778                OPT_GROUP(""),
 779#if NO_EXTERNAL_GREP
 780                OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
 781                        "allow calling of grep(1) (ignored by this build)"),
 782#else
 783                OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
 784                        "allow calling of grep(1) (default)"),
 785#endif
 786                { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 787                  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 788                OPT_END()
 789        };
 790
 791        memset(&opt, 0, sizeof(opt));
 792        opt.prefix = prefix;
 793        opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 794        opt.relative = 1;
 795        opt.pathname = 1;
 796        opt.pattern_tail = &opt.pattern_list;
 797        opt.regflags = REG_NEWLINE;
 798        opt.max_depth = -1;
 799
 800        strcpy(opt.color_match, GIT_COLOR_RED GIT_COLOR_BOLD);
 801        opt.color = -1;
 802        git_config(grep_config, &opt);
 803        if (opt.color == -1)
 804                opt.color = git_use_color_default;
 805
 806        /*
 807         * If there is no -- then the paths must exist in the working
 808         * tree.  If there is no explicit pattern specified with -e or
 809         * -f, we take the first unrecognized non option to be the
 810         * pattern, but then what follows it must be zero or more
 811         * valid refs up to the -- (if exists), and then existing
 812         * paths.  If there is an explicit pattern, then the first
 813         * unrecognized non option is the beginning of the refs list
 814         * that continues up to the -- (if exists), and then paths.
 815         */
 816        argc = parse_options(argc, argv, prefix, options, grep_usage,
 817                             PARSE_OPT_KEEP_DASHDASH |
 818                             PARSE_OPT_STOP_AT_NON_OPTION |
 819                             PARSE_OPT_NO_INTERNAL_HELP);
 820
 821        /* First unrecognized non-option token */
 822        if (argc > 0 && !opt.pattern_list) {
 823                append_grep_pattern(&opt, argv[0], "command line", 0,
 824                                    GREP_PATTERN);
 825                argv++;
 826                argc--;
 827        }
 828
 829        if ((opt.color && !opt.color_external) || opt.funcname)
 830                external_grep_allowed = 0;
 831        if (!opt.pattern_list)
 832                die("no pattern given.");
 833        if ((opt.regflags != REG_NEWLINE) && opt.fixed)
 834                die("cannot mix --fixed-strings and regexp");
 835        compile_grep_patterns(&opt);
 836
 837        /* Check revs and then paths */
 838        for (i = 0; i < argc; i++) {
 839                const char *arg = argv[i];
 840                unsigned char sha1[20];
 841                /* Is it a rev? */
 842                if (!get_sha1(arg, sha1)) {
 843                        struct object *object = parse_object(sha1);
 844                        if (!object)
 845                                die("bad object %s", arg);
 846                        add_object_array(object, arg, &list);
 847                        continue;
 848                }
 849                if (!strcmp(arg, "--")) {
 850                        i++;
 851                        seen_dashdash = 1;
 852                }
 853                break;
 854        }
 855
 856        /* The rest are paths */
 857        if (!seen_dashdash) {
 858                int j;
 859                for (j = i; j < argc; j++)
 860                        verify_filename(prefix, argv[j]);
 861        }
 862
 863        if (i < argc)
 864                paths = get_pathspec(prefix, argv + i);
 865        else if (prefix) {
 866                paths = xcalloc(2, sizeof(const char *));
 867                paths[0] = prefix;
 868                paths[1] = NULL;
 869        }
 870
 871        if (!list.nr) {
 872                if (!cached)
 873                        setup_work_tree();
 874                return !grep_cache(&opt, paths, cached, external_grep_allowed);
 875        }
 876
 877        if (cached)
 878                die("both --cached and trees are given.");
 879
 880        for (i = 0; i < list.nr; i++) {
 881                struct object *real_obj;
 882                real_obj = deref_tag(list.objects[i].item, NULL, 0);
 883                if (grep_object(&opt, paths, real_obj, list.objects[i].name))
 884                        hit = 1;
 885        }
 886        free_grep_patterns(&opt);
 887        return !hit;
 888}