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 #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  */
  27 static 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
  91 static 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
 128 static 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
 165 static 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  */
 206 static 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
 270 static 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
 377 static 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
 421 static 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         char *path_buf = xmalloc(PATH_MAX + tn_len + 100);
 431
 432         if (tn_len) {
 433                 tn_len = sprintf(path_buf, "%s:", tree_name);
 434                 down = path_buf + tn_len;
 435                 strcat(down, base);
 436         }
 437         else {
 438                 down = path_buf;
 439                 strcpy(down, base);
 440         }
 441         len = strlen(path_buf);
 442
 443         while (tree_entry(tree, &entry)) {
 444                 strcpy(path_buf + len, entry.path);
 445
 446                 if (S_ISDIR(entry.mode))
 447                         /* Match "abc/" against pathspec to
 448                          * decide if we want to descend into "abc"
 449                          * directory.
 450                          */
 451                         strcpy(path_buf + len + tree_entry_len(entry.path, entry.sha1), "/");
 452
 453                 if (!pathspec_matches(paths, down))
 454                         ;
 455                 else if (S_ISREG(entry.mode))
 456                         hit |= grep_sha1(opt, entry.sha1, path_buf, tn_len);
 457                 else if (S_ISDIR(entry.mode)) {
 458                         enum object_type type;
 459                         struct tree_desc sub;
 460                         void *data;
 461                         unsigned long size;
 462
 463                         data = read_sha1_file(entry.sha1, &type, &size);
 464                         if (!data)
 465                                 die("unable to read tree (%s)",
 466                                     sha1_to_hex(entry.sha1));
 467                         init_tree_desc(&sub, data, size);
 468                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
 469                         free(data);
 470                 }
 471         }
 472         return hit;
 473 }
 474
 475 static int grep_object(struct grep_opt *opt, const char **paths,
 476                        struct object *obj, const char *name)
 477 {
 478         if (obj->type == OBJ_BLOB)
 479                 return grep_sha1(opt, obj->sha1, name, 0);
 480         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 481                 struct tree_desc tree;
 482                 void *data;
 483                 unsigned long size;
 484                 int hit;
 485                 data = read_object_with_reference(obj->sha1, tree_type,
 486                                                   &size, NULL);
 487                 if (!data)
 488                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 489                 init_tree_desc(&tree, data, size);
 490                 hit = grep_tree(opt, paths, &tree, name, "");
 491                 free(data);
 492                 return hit;
 493         }
 494         die("unable to grep from object of type %s", typename(obj->type));
 495 }
 496
 497 static const char builtin_grep_usage[] =
 498 "git-grep <option>* <rev>* [-e] <pattern> [<path>...]";
 499
 500 static const char emsg_invalid_context_len[] =
 501 "%s: invalid context length argument";
 502 static const char emsg_missing_context_len[] =
 503 "missing context length argument";
 504 static const char emsg_missing_argument[] =
 505 "option requires an argument -%s";
 506
 507 int cmd_grep(int argc, const char **argv, const char *prefix)
 508 {
 509         int hit = 0;
 510         int cached = 0;
 511         int seen_dashdash = 0;
 512         struct grep_opt opt;
 513         struct object_array list = { 0, 0, NULL };
 514         const char **paths = NULL;
 515         int i;
 516
 517         memset(&opt, 0, sizeof(opt));
 518         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 519         opt.relative = 1;
 520         opt.pathname = 1;
 521         opt.pattern_tail = &opt.pattern_list;
 522         opt.regflags = REG_NEWLINE;
 523
 524         /*
 525          * If there is no -- then the paths must exist in the working
 526          * tree.  If there is no explicit pattern specified with -e or
 527          * -f, we take the first unrecognized non option to be the
 528          * pattern, but then what follows it must be zero or more
 529          * valid refs up to the -- (if exists), and then existing
 530          * paths.  If there is an explicit pattern, then the first
 531          * unrecognized non option is the beginning of the refs list
 532          * that continues up to the -- (if exists), and then paths.
 533          */
 534
 535         while (1 < argc) {
 536                 const char *arg = argv[1];
 537                 argc--; argv++;
 538                 if (!strcmp("--cached", arg)) {
 539                         cached = 1;
 540                         continue;
 541                 }
 542                 if (!strcmp("-a", arg) ||
 543                     !strcmp("--text", arg)) {
 544                         opt.binary = GREP_BINARY_TEXT;
 545                         continue;
 546                 }
 547                 if (!strcmp("-i", arg) ||
 548                     !strcmp("--ignore-case", arg)) {
 549                         opt.regflags |= REG_ICASE;
 550                         continue;
 551                 }
 552                 if (!strcmp("-I", arg)) {
 553                         opt.binary = GREP_BINARY_NOMATCH;
 554                         continue;
 555                 }
 556                 if (!strcmp("-v", arg) ||
 557                     !strcmp("--invert-match", arg)) {
 558                         opt.invert = 1;
 559                         continue;
 560                 }
 561                 if (!strcmp("-E", arg) ||
 562                     !strcmp("--extended-regexp", arg)) {
 563                         opt.regflags |= REG_EXTENDED;
 564                         continue;
 565                 }
 566                 if (!strcmp("-F", arg) ||
 567                     !strcmp("--fixed-strings", arg)) {
 568                         opt.fixed = 1;
 569                         continue;
 570                 }
 571                 if (!strcmp("-G", arg) ||
 572                     !strcmp("--basic-regexp", arg)) {
 573                         opt.regflags &= ~REG_EXTENDED;
 574                         continue;
 575                 }
 576                 if (!strcmp("-n", arg)) {
 577                         opt.linenum = 1;
 578                         continue;
 579                 }
 580                 if (!strcmp("-h", arg)) {
 581                         opt.pathname = 0;
 582                         continue;
 583                 }
 584                 if (!strcmp("-H", arg)) {
 585                         opt.pathname = 1;
 586                         continue;
 587                 }
 588                 if (!strcmp("-l", arg) ||
 589                     !strcmp("--name-only", arg) ||
 590                     !strcmp("--files-with-matches", arg)) {
 591                         opt.name_only = 1;
 592                         continue;
 593                 }
 594                 if (!strcmp("-L", arg) ||
 595                     !strcmp("--files-without-match", arg)) {
 596                         opt.unmatch_name_only = 1;
 597                         continue;
 598                 }
 599                 if (!strcmp("-c", arg) ||
 600                     !strcmp("--count", arg)) {
 601                         opt.count = 1;
 602                         continue;
 603                 }
 604                 if (!strcmp("-w", arg) ||
 605                     !strcmp("--word-regexp", arg)) {
 606                         opt.word_regexp = 1;
 607                         continue;
 608                 }
 609                 if (!prefixcmp(arg, "-A") ||
 610                     !prefixcmp(arg, "-B") ||
 611                     !prefixcmp(arg, "-C") ||
 612                     (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
 613                         unsigned num;
 614                         const char *scan;
 615                         switch (arg[1]) {
 616                         case 'A': case 'B': case 'C':
 617                                 if (!arg[2]) {
 618                                         if (argc <= 1)
 619                                                 die(emsg_missing_context_len);
 620                                         scan = *++argv;
 621                                         argc--;
 622                                 }
 623                                 else
 624                                         scan = arg + 2;
 625                                 break;
 626                         default:
 627                                 scan = arg + 1;
 628                                 break;
 629                         }
 630                         if (strtoul_ui(scan, 10, &num))
 631                                 die(emsg_invalid_context_len, scan);
 632                         switch (arg[1]) {
 633                         case 'A':
 634                                 opt.post_context = num;
 635                                 break;
 636                         default:
 637                         case 'C':
 638                                 opt.post_context = num;
 639                         case 'B':
 640                                 opt.pre_context = num;
 641                                 break;
 642                         }
 643                         continue;
 644                 }
 645                 if (!strcmp("-f", arg)) {
 646                         FILE *patterns;
 647                         int lno = 0;
 648                         char buf[1024];
 649                         if (argc <= 1)
 650                                 die(emsg_missing_argument, arg);
 651                         patterns = fopen(argv[1], "r");
 652                         if (!patterns)
 653                                 die("'%s': %s", argv[1], strerror(errno));
 654                         while (fgets(buf, sizeof(buf), patterns)) {
 655                                 int len = strlen(buf);
 656                                 if (len && buf[len-1] == '\n')
 657                                         buf[len-1] = 0;
 658                                 /* ignore empty line like grep does */
 659                                 if (!buf[0])
 660                                         continue;
 661                                 append_grep_pattern(&opt, xstrdup(buf),
 662                                                     argv[1], ++lno,
 663                                                     GREP_PATTERN);
 664                         }
 665                         fclose(patterns);
 666                         argv++;
 667                         argc--;
 668                         continue;
 669                 }
 670                 if (!strcmp("--not", arg)) {
 671                         append_grep_pattern(&opt, arg, "command line", 0,
 672                                             GREP_NOT);
 673                         continue;
 674                 }
 675                 if (!strcmp("--and", arg)) {
 676                         append_grep_pattern(&opt, arg, "command line", 0,
 677                                             GREP_AND);
 678                         continue;
 679                 }
 680                 if (!strcmp("--or", arg))
 681                         continue; /* no-op */
 682                 if (!strcmp("(", arg)) {
 683                         append_grep_pattern(&opt, arg, "command line", 0,
 684                                             GREP_OPEN_PAREN);
 685                         continue;
 686                 }
 687                 if (!strcmp(")", arg)) {
 688                         append_grep_pattern(&opt, arg, "command line", 0,
 689                                             GREP_CLOSE_PAREN);
 690                         continue;
 691                 }
 692                 if (!strcmp("--all-match", arg)) {
 693                         opt.all_match = 1;
 694                         continue;
 695                 }
 696                 if (!strcmp("-e", arg)) {
 697                         if (1 < argc) {
 698                                 append_grep_pattern(&opt, argv[1],
 699                                                     "-e option", 0,
 700                                                     GREP_PATTERN);
 701                                 argv++;
 702                                 argc--;
 703                                 continue;
 704                         }
 705                         die(emsg_missing_argument, arg);
 706                 }
 707                 if (!strcmp("--full-name", arg)) {
 708                         opt.relative = 0;
 709                         continue;
 710                 }
 711                 if (!strcmp("--", arg)) {
 712                         /* later processing wants to have this at argv[1] */
 713                         argv--;
 714                         argc++;
 715                         break;
 716                 }
 717                 if (*arg == '-')
 718                         usage(builtin_grep_usage);
 719
 720                 /* First unrecognized non-option token */
 721                 if (!opt.pattern_list) {
 722                         append_grep_pattern(&opt, arg, "command line", 0,
 723                                             GREP_PATTERN);
 724                         break;
 725                 }
 726                 else {
 727                         /* We are looking at the first path or rev;
 728                          * it is found at argv[1] after leaving the
 729                          * loop.
 730                          */
 731                         argc++; argv--;
 732                         break;
 733                 }
 734         }
 735
 736         if (!opt.pattern_list)
 737                 die("no pattern given.");
 738         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
 739                 die("cannot mix --fixed-strings and regexp");
 740         compile_grep_patterns(&opt);
 741
 742         /* Check revs and then paths */
 743         for (i = 1; i < argc; i++) {
 744                 const char *arg = argv[i];
 745                 unsigned char sha1[20];
 746                 /* Is it a rev? */
 747                 if (!get_sha1(arg, sha1)) {
 748                         struct object *object = parse_object(sha1);
 749                         if (!object)
 750                                 die("bad object %s", arg);
 751                         add_object_array(object, arg, &list);
 752                         continue;
 753                 }
 754                 if (!strcmp(arg, "--")) {
 755                         i++;
 756                         seen_dashdash = 1;
 757                 }
 758                 break;
 759         }
 760
 761         /* The rest are paths */
 762         if (!seen_dashdash) {
 763                 int j;
 764                 for (j = i; j < argc; j++)
 765                         verify_filename(prefix, argv[j]);
 766         }
 767
 768         if (i < argc) {
 769                 paths = get_pathspec(prefix, argv + i);
 770                 if (opt.prefix_length && opt.relative) {
 771                         /* Make sure we do not get outside of paths */
 772                         for (i = 0; paths[i]; i++)
 773                                 if (strncmp(prefix, paths[i], opt.prefix_length))
 774                                         die("git-grep: cannot generate relative filenames containing '..'");
 775                 }
 776         }
 777         else if (prefix) {
 778                 paths = xcalloc(2, sizeof(const char *));
 779                 paths[0] = prefix;
 780                 paths[1] = NULL;
 781         }
 782
 783         if (!list.nr)
 784                 return !grep_cache(&opt, paths, cached);
 785
 786         if (cached)
 787                 die("both --cached and trees are given.");
 788
 789         for (i = 0; i < list.nr; i++) {
 790                 struct object *real_obj;
 791                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
 792                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
 793                         hit = 1;
 794         }
 795         free_grep_patterns(&opt);
 796         return !hit;
 797 }