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 "parse-options.h"
  14 #include "string-list.h"
  15 #include "run-command.h"
  16 #include "userdiff.h"
  17 #include "grep.h"
  18 #include "quote.h"
  19 #include "dir.h"
  20
  21 static char const * const grep_usage[] = {
  22         N_("git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]"),
  23         NULL
  24 };
  25
  26 static int use_threads = 1;
  27
  28 #ifndef NO_PTHREADS
  29 #define THREADS 8
  30 static pthread_t threads[THREADS];
  31
  32 /* We use one producer thread and THREADS consumer
  33  * threads. The producer adds struct work_items to 'todo' and the
  34  * consumers pick work items from the same array.
  35  */
  36 struct work_item {
  37         struct grep_source source;
  38         char done;
  39         struct strbuf out;
  40 };
  41
  42 /* In the range [todo_done, todo_start) in 'todo' we have work_items
  43  * that have been or are processed by a consumer thread. We haven't
  44  * written the result for these to stdout yet.
  45  *
  46  * The work_items in [todo_start, todo_end) are waiting to be picked
  47  * up by a consumer thread.
  48  *
  49  * The ranges are modulo TODO_SIZE.
  50  */
  51 #define TODO_SIZE 128
  52 static struct work_item todo[TODO_SIZE];
  53 static int todo_start;
  54 static int todo_end;
  55 static int todo_done;
  56
  57 /* Has all work items been added? */
  58 static int all_work_added;
  59
  60 /* This lock protects all the variables above. */
  61 static pthread_mutex_t grep_mutex;
  62
  63 static inline void grep_lock(void)
  64 {
  65         if (use_threads)
  66                 pthread_mutex_lock(&grep_mutex);
  67 }
  68
  69 static inline void grep_unlock(void)
  70 {
  71         if (use_threads)
  72                 pthread_mutex_unlock(&grep_mutex);
  73 }
  74
  75 /* Signalled when a new work_item is added to todo. */
  76 static pthread_cond_t cond_add;
  77
  78 /* Signalled when the result from one work_item is written to
  79  * stdout.
  80  */
  81 static pthread_cond_t cond_write;
  82
  83 /* Signalled when we are finished with everything. */
  84 static pthread_cond_t cond_result;
  85
  86 static int skip_first_line;
  87
  88 static void add_work(struct grep_opt *opt, enum grep_source_type type,
  89                      const char *name, const void *id)
  90 {
  91         grep_lock();
  92
  93         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
  94                 pthread_cond_wait(&cond_write, &grep_mutex);
  95         }
  96
  97         grep_source_init(&todo[todo_end].source, type, name, id);
  98         if (opt->binary != GREP_BINARY_TEXT)
  99                 grep_source_load_driver(&todo[todo_end].source);
 100         todo[todo_end].done = 0;
 101         strbuf_reset(&todo[todo_end].out);
 102         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 103
 104         pthread_cond_signal(&cond_add);
 105         grep_unlock();
 106 }
 107
 108 static struct work_item *get_work(void)
 109 {
 110         struct work_item *ret;
 111
 112         grep_lock();
 113         while (todo_start == todo_end && !all_work_added) {
 114                 pthread_cond_wait(&cond_add, &grep_mutex);
 115         }
 116
 117         if (todo_start == todo_end && all_work_added) {
 118                 ret = NULL;
 119         } else {
 120                 ret = &todo[todo_start];
 121                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 122         }
 123         grep_unlock();
 124         return ret;
 125 }
 126
 127 static void work_done(struct work_item *w)
 128 {
 129         int old_done;
 130
 131         grep_lock();
 132         w->done = 1;
 133         old_done = todo_done;
 134         for(; todo[todo_done].done && todo_done != todo_start;
 135             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 136                 w = &todo[todo_done];
 137                 if (w->out.len) {
 138                         const char *p = w->out.buf;
 139                         size_t len = w->out.len;
 140
 141                         /* Skip the leading hunk mark of the first file. */
 142                         if (skip_first_line) {
 143                                 while (len) {
 144                                         len--;
 145                                         if (*p++ == '\n')
 146                                                 break;
 147                                 }
 148                                 skip_first_line = 0;
 149                         }
 150
 151                         write_or_die(1, p, len);
 152                 }
 153                 grep_source_clear(&w->source);
 154         }
 155
 156         if (old_done != todo_done)
 157                 pthread_cond_signal(&cond_write);
 158
 159         if (all_work_added && todo_done == todo_end)
 160                 pthread_cond_signal(&cond_result);
 161
 162         grep_unlock();
 163 }
 164
 165 static void *run(void *arg)
 166 {
 167         int hit = 0;
 168         struct grep_opt *opt = arg;
 169
 170         while (1) {
 171                 struct work_item *w = get_work();
 172                 if (!w)
 173                         break;
 174
 175                 opt->output_priv = w;
 176                 hit |= grep_source(opt, &w->source);
 177                 grep_source_clear_data(&w->source);
 178                 work_done(w);
 179         }
 180         free_grep_patterns(arg);
 181         free(arg);
 182
 183         return (void*) (intptr_t) hit;
 184 }
 185
 186 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 187 {
 188         struct work_item *w = opt->output_priv;
 189         strbuf_add(&w->out, buf, size);
 190 }
 191
 192 static void start_threads(struct grep_opt *opt)
 193 {
 194         int i;
 195
 196         pthread_mutex_init(&grep_mutex, NULL);
 197         pthread_mutex_init(&grep_read_mutex, NULL);
 198         pthread_mutex_init(&grep_attr_mutex, NULL);
 199         pthread_cond_init(&cond_add, NULL);
 200         pthread_cond_init(&cond_write, NULL);
 201         pthread_cond_init(&cond_result, NULL);
 202         grep_use_locks = 1;
 203
 204         for (i = 0; i < ARRAY_SIZE(todo); i++) {
 205                 strbuf_init(&todo[i].out, 0);
 206         }
 207
 208         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 209                 int err;
 210                 struct grep_opt *o = grep_opt_dup(opt);
 211                 o->output = strbuf_out;
 212                 o->debug = 0;
 213                 compile_grep_patterns(o);
 214                 err = pthread_create(&threads[i], NULL, run, o);
 215
 216                 if (err)
 217                         die(_("grep: failed to create thread: %s"),
 218                             strerror(err));
 219         }
 220 }
 221
 222 static int wait_all(void)
 223 {
 224         int hit = 0;
 225         int i;
 226
 227         grep_lock();
 228         all_work_added = 1;
 229
 230         /* Wait until all work is done. */
 231         while (todo_done != todo_end)
 232                 pthread_cond_wait(&cond_result, &grep_mutex);
 233
 234         /* Wake up all the consumer threads so they can see that there
 235          * is no more work to do.
 236          */
 237         pthread_cond_broadcast(&cond_add);
 238         grep_unlock();
 239
 240         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 241                 void *h;
 242                 pthread_join(threads[i], &h);
 243                 hit |= (int) (intptr_t) h;
 244         }
 245
 246         pthread_mutex_destroy(&grep_mutex);
 247         pthread_mutex_destroy(&grep_read_mutex);
 248         pthread_mutex_destroy(&grep_attr_mutex);
 249         pthread_cond_destroy(&cond_add);
 250         pthread_cond_destroy(&cond_write);
 251         pthread_cond_destroy(&cond_result);
 252         grep_use_locks = 0;
 253
 254         return hit;
 255 }
 256 #else /* !NO_PTHREADS */
 257
 258 static int wait_all(void)
 259 {
 260         return 0;
 261 }
 262 #endif
 263
 264 static int grep_cmd_config(const char *var, const char *value, void *cb)
 265 {
 266         int st = grep_config(var, value, cb);
 267         if (git_color_default_config(var, value, cb) < 0)
 268                 st = -1;
 269         return st;
 270 }
 271
 272 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 273 {
 274         void *data;
 275
 276         grep_read_lock();
 277         data = read_sha1_file(sha1, type, size);
 278         grep_read_unlock();
 279         return data;
 280 }
 281
 282 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 283                      const char *filename, int tree_name_len)
 284 {
 285         struct strbuf pathbuf = STRBUF_INIT;
 286
 287         if (opt->relative && opt->prefix_length) {
 288                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
 289                                     opt->prefix);
 290                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 291         } else {
 292                 strbuf_addstr(&pathbuf, filename);
 293         }
 294
 295 #ifndef NO_PTHREADS
 296         if (use_threads) {
 297                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 298                 strbuf_release(&pathbuf);
 299                 return 0;
 300         } else
 301 #endif
 302         {
 303                 struct grep_source gs;
 304                 int hit;
 305
 306                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 307                 strbuf_release(&pathbuf);
 308                 hit = grep_source(opt, &gs);
 309
 310                 grep_source_clear(&gs);
 311                 return hit;
 312         }
 313 }
 314
 315 static int grep_file(struct grep_opt *opt, const char *filename)
 316 {
 317         struct strbuf buf = STRBUF_INIT;
 318
 319         if (opt->relative && opt->prefix_length)
 320                 quote_path_relative(filename, -1, &buf, opt->prefix);
 321         else
 322                 strbuf_addstr(&buf, filename);
 323
 324 #ifndef NO_PTHREADS
 325         if (use_threads) {
 326                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename);
 327                 strbuf_release(&buf);
 328                 return 0;
 329         } else
 330 #endif
 331         {
 332                 struct grep_source gs;
 333                 int hit;
 334
 335                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename);
 336                 strbuf_release(&buf);
 337                 hit = grep_source(opt, &gs);
 338
 339                 grep_source_clear(&gs);
 340                 return hit;
 341         }
 342 }
 343
 344 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 345 {
 346         struct string_list *path_list = opt->output_priv;
 347
 348         if (len == 1 && *(const char *)data == '\0')
 349                 return;
 350         string_list_append(path_list, xstrndup(data, len));
 351 }
 352
 353 static void run_pager(struct grep_opt *opt, const char *prefix)
 354 {
 355         struct string_list *path_list = opt->output_priv;
 356         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 357         int i, status;
 358
 359         for (i = 0; i < path_list->nr; i++)
 360                 argv[i] = path_list->items[i].string;
 361         argv[path_list->nr] = NULL;
 362
 363         if (prefix && chdir(prefix))
 364                 die(_("Failed to chdir: %s"), prefix);
 365         status = run_command_v_opt(argv, RUN_USING_SHELL);
 366         if (status)
 367                 exit(status);
 368         free(argv);
 369 }
 370
 371 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 372 {
 373         int hit = 0;
 374         int nr;
 375         read_cache();
 376
 377         for (nr = 0; nr < active_nr; nr++) {
 378                 struct cache_entry *ce = active_cache[nr];
 379                 if (!S_ISREG(ce->ce_mode))
 380                         continue;
 381                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 382                         continue;
 383                 /*
 384                  * If CE_VALID is on, we assume worktree file and its cache entry
 385                  * are identical, even if worktree file has been modified, so use
 386                  * cache version instead
 387                  */
 388                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 389                         if (ce_stage(ce))
 390                                 continue;
 391                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 392                 }
 393                 else
 394                         hit |= grep_file(opt, ce->name);
 395                 if (ce_stage(ce)) {
 396                         do {
 397                                 nr++;
 398                         } while (nr < active_nr &&
 399                                  !strcmp(ce->name, active_cache[nr]->name));
 400                         nr--; /* compensate for loop control */
 401                 }
 402                 if (hit && opt->status_only)
 403                         break;
 404         }
 405         return hit;
 406 }
 407
 408 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 409                      struct tree_desc *tree, struct strbuf *base, int tn_len)
 410 {
 411         int hit = 0;
 412         enum interesting match = entry_not_interesting;
 413         struct name_entry entry;
 414         int old_baselen = base->len;
 415
 416         while (tree_entry(tree, &entry)) {
 417                 int te_len = tree_entry_len(&entry);
 418
 419                 if (match != all_entries_interesting) {
 420                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 421                         if (match == all_entries_not_interesting)
 422                                 break;
 423                         if (match == entry_not_interesting)
 424                                 continue;
 425                 }
 426
 427                 strbuf_add(base, entry.path, te_len);
 428
 429                 if (S_ISREG(entry.mode)) {
 430                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
 431                 }
 432                 else if (S_ISDIR(entry.mode)) {
 433                         enum object_type type;
 434                         struct tree_desc sub;
 435                         void *data;
 436                         unsigned long size;
 437
 438                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 439                         if (!data)
 440                                 die(_("unable to read tree (%s)"),
 441                                     sha1_to_hex(entry.sha1));
 442
 443                         strbuf_addch(base, '/');
 444                         init_tree_desc(&sub, data, size);
 445                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
 446                         free(data);
 447                 }
 448                 strbuf_setlen(base, old_baselen);
 449
 450                 if (hit && opt->status_only)
 451                         break;
 452         }
 453         return hit;
 454 }
 455
 456 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 457                        struct object *obj, const char *name)
 458 {
 459         if (obj->type == OBJ_BLOB)
 460                 return grep_sha1(opt, obj->sha1, name, 0);
 461         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 462                 struct tree_desc tree;
 463                 void *data;
 464                 unsigned long size;
 465                 struct strbuf base;
 466                 int hit, len;
 467
 468                 grep_read_lock();
 469                 data = read_object_with_reference(obj->sha1, tree_type,
 470                                                   &size, NULL);
 471                 grep_read_unlock();
 472
 473                 if (!data)
 474                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 475
 476                 len = name ? strlen(name) : 0;
 477                 strbuf_init(&base, PATH_MAX + len + 1);
 478                 if (len) {
 479                         strbuf_add(&base, name, len);
 480                         strbuf_addch(&base, ':');
 481                 }
 482                 init_tree_desc(&tree, data, size);
 483                 hit = grep_tree(opt, pathspec, &tree, &base, base.len);
 484                 strbuf_release(&base);
 485                 free(data);
 486                 return hit;
 487         }
 488         die(_("unable to grep from object of type %s"), typename(obj->type));
 489 }
 490
 491 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 492                         const struct object_array *list)
 493 {
 494         unsigned int i;
 495         int hit = 0;
 496         const unsigned int nr = list->nr;
 497
 498         for (i = 0; i < nr; i++) {
 499                 struct object *real_obj;
 500                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
 501                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 502                         hit = 1;
 503                         if (opt->status_only)
 504                                 break;
 505                 }
 506         }
 507         return hit;
 508 }
 509
 510 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 511                           int exc_std)
 512 {
 513         struct dir_struct dir;
 514         int i, hit = 0;
 515
 516         memset(&dir, 0, sizeof(dir));
 517         if (exc_std)
 518                 setup_standard_excludes(&dir);
 519
 520         fill_directory(&dir, pathspec->raw);
 521         for (i = 0; i < dir.nr; i++) {
 522                 const char *name = dir.entries[i]->name;
 523                 int namelen = strlen(name);
 524                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 525                         continue;
 526                 hit |= grep_file(opt, dir.entries[i]->name);
 527                 if (hit && opt->status_only)
 528                         break;
 529         }
 530         return hit;
 531 }
 532
 533 static int context_callback(const struct option *opt, const char *arg,
 534                             int unset)
 535 {
 536         struct grep_opt *grep_opt = opt->value;
 537         int value;
 538         const char *endp;
 539
 540         if (unset) {
 541                 grep_opt->pre_context = grep_opt->post_context = 0;
 542                 return 0;
 543         }
 544         value = strtol(arg, (char **)&endp, 10);
 545         if (*endp) {
 546                 return error(_("switch `%c' expects a numerical value"),
 547                              opt->short_name);
 548         }
 549         grep_opt->pre_context = grep_opt->post_context = value;
 550         return 0;
 551 }
 552
 553 static int file_callback(const struct option *opt, const char *arg, int unset)
 554 {
 555         struct grep_opt *grep_opt = opt->value;
 556         int from_stdin = !strcmp(arg, "-");
 557         FILE *patterns;
 558         int lno = 0;
 559         struct strbuf sb = STRBUF_INIT;
 560
 561         patterns = from_stdin ? stdin : fopen(arg, "r");
 562         if (!patterns)
 563                 die_errno(_("cannot open '%s'"), arg);
 564         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 565                 /* ignore empty line like grep does */
 566                 if (sb.len == 0)
 567                         continue;
 568
 569                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 570                                 GREP_PATTERN);
 571         }
 572         if (!from_stdin)
 573                 fclose(patterns);
 574         strbuf_release(&sb);
 575         return 0;
 576 }
 577
 578 static int not_callback(const struct option *opt, const char *arg, int unset)
 579 {
 580         struct grep_opt *grep_opt = opt->value;
 581         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 582         return 0;
 583 }
 584
 585 static int and_callback(const struct option *opt, const char *arg, int unset)
 586 {
 587         struct grep_opt *grep_opt = opt->value;
 588         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 589         return 0;
 590 }
 591
 592 static int open_callback(const struct option *opt, const char *arg, int unset)
 593 {
 594         struct grep_opt *grep_opt = opt->value;
 595         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 596         return 0;
 597 }
 598
 599 static int close_callback(const struct option *opt, const char *arg, int unset)
 600 {
 601         struct grep_opt *grep_opt = opt->value;
 602         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 603         return 0;
 604 }
 605
 606 static int pattern_callback(const struct option *opt, const char *arg,
 607                             int unset)
 608 {
 609         struct grep_opt *grep_opt = opt->value;
 610         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 611         return 0;
 612 }
 613
 614 static int help_callback(const struct option *opt, const char *arg, int unset)
 615 {
 616         return -1;
 617 }
 618
 619 int cmd_grep(int argc, const char **argv, const char *prefix)
 620 {
 621         int hit = 0;
 622         int cached = 0, untracked = 0, opt_exclude = -1;
 623         int seen_dashdash = 0;
 624         int external_grep_allowed__ignored;
 625         const char *show_in_pager = NULL, *default_pager = "dummy";
 626         struct grep_opt opt;
 627         struct object_array list = OBJECT_ARRAY_INIT;
 628         const char **paths = NULL;
 629         struct pathspec pathspec;
 630         struct string_list path_list = STRING_LIST_INIT_NODUP;
 631         int i;
 632         int dummy;
 633         int use_index = 1;
 634         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 635
 636         struct option options[] = {
 637                 OPT_BOOLEAN(0, "cached", &cached,
 638                         N_("search in index instead of in the work tree")),
 639                 OPT_NEGBIT(0, "no-index", &use_index,
 640                          N_("find in contents not managed by git"), 1),
 641                 OPT_BOOLEAN(0, "untracked", &untracked,
 642                         N_("search in both tracked and untracked files")),
 643                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 644                             N_("search also in ignored files"), 1),
 645                 OPT_GROUP(""),
 646                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 647                         N_("show non-matching lines")),
 648                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 649                         N_("case insensitive matching")),
 650                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 651                         N_("match patterns only at word boundaries")),
 652                 OPT_SET_INT('a', "text", &opt.binary,
 653                         N_("process binary files as text"), GREP_BINARY_TEXT),
 654                 OPT_SET_INT('I', NULL, &opt.binary,
 655                         N_("don't match patterns in binary files"),
 656                         GREP_BINARY_NOMATCH),
 657                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 658                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 659                         NULL, 1 },
 660                 OPT_GROUP(""),
 661                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 662                             N_("use extended POSIX regular expressions"),
 663                             GREP_PATTERN_TYPE_ERE),
 664                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 665                             N_("use basic POSIX regular expressions (default)"),
 666                             GREP_PATTERN_TYPE_BRE),
 667                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 668                             N_("interpret patterns as fixed strings"),
 669                             GREP_PATTERN_TYPE_FIXED),
 670                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 671                             N_("use Perl-compatible regular expressions"),
 672                             GREP_PATTERN_TYPE_PCRE),
 673                 OPT_GROUP(""),
 674                 OPT_BOOLEAN('n', "line-number", &opt.linenum, N_("show line numbers")),
 675                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 676                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 677                 OPT_NEGBIT(0, "full-name", &opt.relative,
 678                         N_("show filenames relative to top directory"), 1),
 679                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 680                         N_("show only filenames instead of matching lines")),
 681                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 682                         N_("synonym for --files-with-matches")),
 683                 OPT_BOOLEAN('L', "files-without-match",
 684                         &opt.unmatch_name_only,
 685                         N_("show only the names of files without match")),
 686                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 687                         N_("print NUL after filenames")),
 688                 OPT_BOOLEAN('c', "count", &opt.count,
 689                         N_("show the number of matches instead of matching lines")),
 690                 OPT__COLOR(&opt.color, N_("highlight matches")),
 691                 OPT_BOOLEAN(0, "break", &opt.file_break,
 692                         N_("print empty line between matches from different files")),
 693                 OPT_BOOLEAN(0, "heading", &opt.heading,
 694                         N_("show filename only once above matches from same file")),
 695                 OPT_GROUP(""),
 696                 OPT_CALLBACK('C', "context", &opt, N_("n"),
 697                         N_("show <n> context lines before and after matches"),
 698                         context_callback),
 699                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 700                         N_("show <n> context lines before matches")),
 701                 OPT_INTEGER('A', "after-context", &opt.post_context,
 702                         N_("show <n> context lines after matches")),
 703                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 704                         context_callback),
 705                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 706                         N_("show a line with the function name before matches")),
 707                 OPT_BOOLEAN('W', "function-context", &opt.funcbody,
 708                         N_("show the surrounding function")),
 709                 OPT_GROUP(""),
 710                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
 711                         N_("read patterns from file"), file_callback),
 712                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 713                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 714                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 715                   N_("combine patterns specified with -e"),
 716                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 717                 OPT_BOOLEAN(0, "or", &dummy, ""),
 718                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 719                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 720                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 721                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 722                   open_callback },
 723                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 724                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 725                   close_callback },
 726                 OPT__QUIET(&opt.status_only,
 727                            N_("indicate hit with exit status without output")),
 728                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 729                         N_("show only matches from files that match all patterns")),
 730                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 731                   N_("show parse tree for grep expression"),
 732                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 733                 OPT_GROUP(""),
 734                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 735                         N_("pager"), N_("show matching files in the pager"),
 736                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 737                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
 738                             N_("allow calling of grep(1) (ignored by this build)")),
 739                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, N_("show usage"),
 740                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 741                 OPT_END()
 742         };
 743
 744         /*
 745          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 746          * to show usage information and exit.
 747          */
 748         if (argc == 2 && !strcmp(argv[1], "-h"))
 749                 usage_with_options(grep_usage, options);
 750
 751         init_grep_defaults();
 752         git_config(grep_cmd_config, NULL);
 753         grep_init(&opt, prefix);
 754
 755         /*
 756          * If there is no -- then the paths must exist in the working
 757          * tree.  If there is no explicit pattern specified with -e or
 758          * -f, we take the first unrecognized non option to be the
 759          * pattern, but then what follows it must be zero or more
 760          * valid refs up to the -- (if exists), and then existing
 761          * paths.  If there is an explicit pattern, then the first
 762          * unrecognized non option is the beginning of the refs list
 763          * that continues up to the -- (if exists), and then paths.
 764          */
 765         argc = parse_options(argc, argv, prefix, options, grep_usage,
 766                              PARSE_OPT_KEEP_DASHDASH |
 767                              PARSE_OPT_STOP_AT_NON_OPTION |
 768                              PARSE_OPT_NO_INTERNAL_HELP);
 769         grep_commit_pattern_type(pattern_type_arg, &opt);
 770
 771         if (use_index && !startup_info->have_repository)
 772                 /* die the same way as if we did it at the beginning */
 773                 setup_git_directory();
 774
 775         /*
 776          * skip a -- separator; we know it cannot be
 777          * separating revisions from pathnames if
 778          * we haven't even had any patterns yet
 779          */
 780         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 781                 argv++;
 782                 argc--;
 783         }
 784
 785         /* First unrecognized non-option token */
 786         if (argc > 0 && !opt.pattern_list) {
 787                 append_grep_pattern(&opt, argv[0], "command line", 0,
 788                                     GREP_PATTERN);
 789                 argv++;
 790                 argc--;
 791         }
 792
 793         if (show_in_pager == default_pager)
 794                 show_in_pager = git_pager(1);
 795         if (show_in_pager) {
 796                 opt.color = 0;
 797                 opt.name_only = 1;
 798                 opt.null_following_name = 1;
 799                 opt.output_priv = &path_list;
 800                 opt.output = append_path;
 801                 string_list_append(&path_list, show_in_pager);
 802                 use_threads = 0;
 803         }
 804
 805         if (!opt.pattern_list)
 806                 die(_("no pattern given."));
 807         if (!opt.fixed && opt.ignore_case)
 808                 opt.regflags |= REG_ICASE;
 809
 810         compile_grep_patterns(&opt);
 811
 812         /* Check revs and then paths */
 813         for (i = 0; i < argc; i++) {
 814                 const char *arg = argv[i];
 815                 unsigned char sha1[20];
 816                 /* Is it a rev? */
 817                 if (!get_sha1(arg, sha1)) {
 818                         struct object *object = parse_object(sha1);
 819                         if (!object)
 820                                 die(_("bad object %s"), arg);
 821                         add_object_array(object, arg, &list);
 822                         continue;
 823                 }
 824                 if (!strcmp(arg, "--")) {
 825                         i++;
 826                         seen_dashdash = 1;
 827                 }
 828                 break;
 829         }
 830
 831 #ifndef NO_PTHREADS
 832         if (list.nr || cached || online_cpus() == 1)
 833                 use_threads = 0;
 834 #else
 835         use_threads = 0;
 836 #endif
 837
 838 #ifndef NO_PTHREADS
 839         if (use_threads) {
 840                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 841                     && (opt.pre_context || opt.post_context ||
 842                         opt.file_break || opt.funcbody))
 843                         skip_first_line = 1;
 844                 start_threads(&opt);
 845         }
 846 #endif
 847
 848         /* The rest are paths */
 849         if (!seen_dashdash) {
 850                 int j;
 851                 for (j = i; j < argc; j++)
 852                         verify_filename(prefix, argv[j], j == i);
 853         }
 854
 855         paths = get_pathspec(prefix, argv + i);
 856         init_pathspec(&pathspec, paths);
 857         pathspec.max_depth = opt.max_depth;
 858         pathspec.recursive = 1;
 859
 860         if (show_in_pager && (cached || list.nr))
 861                 die(_("--open-files-in-pager only works on the worktree"));
 862
 863         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 864                 const char *pager = path_list.items[0].string;
 865                 int len = strlen(pager);
 866
 867                 if (len > 4 && is_dir_sep(pager[len - 5]))
 868                         pager += len - 4;
 869
 870                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 871                         struct strbuf buf = STRBUF_INIT;
 872                         strbuf_addf(&buf, "+/%s%s",
 873                                         strcmp("less", pager) ? "" : "*",
 874                                         opt.pattern_list->pattern);
 875                         string_list_append(&path_list, buf.buf);
 876                         strbuf_detach(&buf, NULL);
 877                 }
 878         }
 879
 880         if (!show_in_pager)
 881                 setup_pager();
 882
 883         if (!use_index && (untracked || cached))
 884                 die(_("--cached or --untracked cannot be used with --no-index."));
 885
 886         if (!use_index || untracked) {
 887                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 888                 if (list.nr)
 889                         die(_("--no-index or --untracked cannot be used with revs."));
 890                 hit = grep_directory(&opt, &pathspec, use_exclude);
 891         } else if (0 <= opt_exclude) {
 892                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 893         } else if (!list.nr) {
 894                 if (!cached)
 895                         setup_work_tree();
 896
 897                 hit = grep_cache(&opt, &pathspec, cached);
 898         } else {
 899                 if (cached)
 900                         die(_("both --cached and trees are given."));
 901                 hit = grep_objects(&opt, &pathspec, &list);
 902         }
 903
 904         if (use_threads)
 905                 hit |= wait_all();
 906         if (hit && show_in_pager)
 907                 run_pager(&opt, prefix);
 908         free_grep_patterns(&opt);
 909         return !hit;
 910 }