builtin-grep.c

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