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 char *path, 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, path, 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                      const char *path)
 285 {
 286         struct strbuf pathbuf = STRBUF_INIT;
 287
 288         if (opt->relative && opt->prefix_length) {
 289                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
 290                                     opt->prefix);
 291                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 292         } else {
 293                 strbuf_addstr(&pathbuf, filename);
 294         }
 295
 296 #ifndef NO_PTHREADS
 297         if (use_threads) {
 298                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
 299                 strbuf_release(&pathbuf);
 300                 return 0;
 301         } else
 302 #endif
 303         {
 304                 struct grep_source gs;
 305                 int hit;
 306
 307                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
 308                 strbuf_release(&pathbuf);
 309                 hit = grep_source(opt, &gs);
 310
 311                 grep_source_clear(&gs);
 312                 return hit;
 313         }
 314 }
 315
 316 static int grep_file(struct grep_opt *opt, const char *filename)
 317 {
 318         struct strbuf buf = STRBUF_INIT;
 319
 320         if (opt->relative && opt->prefix_length)
 321                 quote_path_relative(filename, -1, &buf, opt->prefix);
 322         else
 323                 strbuf_addstr(&buf, filename);
 324
 325 #ifndef NO_PTHREADS
 326         if (use_threads) {
 327                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename, filename);
 328                 strbuf_release(&buf);
 329                 return 0;
 330         } else
 331 #endif
 332         {
 333                 struct grep_source gs;
 334                 int hit;
 335
 336                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
 337                 strbuf_release(&buf);
 338                 hit = grep_source(opt, &gs);
 339
 340                 grep_source_clear(&gs);
 341                 return hit;
 342         }
 343 }
 344
 345 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 346 {
 347         struct string_list *path_list = opt->output_priv;
 348
 349         if (len == 1 && *(const char *)data == '\0')
 350                 return;
 351         string_list_append(path_list, xstrndup(data, len));
 352 }
 353
 354 static void run_pager(struct grep_opt *opt, const char *prefix)
 355 {
 356         struct string_list *path_list = opt->output_priv;
 357         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 358         int i, status;
 359
 360         for (i = 0; i < path_list->nr; i++)
 361                 argv[i] = path_list->items[i].string;
 362         argv[path_list->nr] = NULL;
 363
 364         if (prefix && chdir(prefix))
 365                 die(_("Failed to chdir: %s"), prefix);
 366         status = run_command_v_opt(argv, RUN_USING_SHELL);
 367         if (status)
 368                 exit(status);
 369         free(argv);
 370 }
 371
 372 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 373 {
 374         int hit = 0;
 375         int nr;
 376         read_cache();
 377
 378         for (nr = 0; nr < active_nr; nr++) {
 379                 struct cache_entry *ce = active_cache[nr];
 380                 if (!S_ISREG(ce->ce_mode))
 381                         continue;
 382                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 383                         continue;
 384                 /*
 385                  * If CE_VALID is on, we assume worktree file and its cache entry
 386                  * are identical, even if worktree file has been modified, so use
 387                  * cache version instead
 388                  */
 389                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 390                         if (ce_stage(ce))
 391                                 continue;
 392                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0, ce->name);
 393                 }
 394                 else
 395                         hit |= grep_file(opt, ce->name);
 396                 if (ce_stage(ce)) {
 397                         do {
 398                                 nr++;
 399                         } while (nr < active_nr &&
 400                                  !strcmp(ce->name, active_cache[nr]->name));
 401                         nr--; /* compensate for loop control */
 402                 }
 403                 if (hit && opt->status_only)
 404                         break;
 405         }
 406         return hit;
 407 }
 408
 409 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 410                      struct tree_desc *tree, struct strbuf *base, int tn_len,
 411                      int check_attr)
 412 {
 413         int hit = 0;
 414         enum interesting match = entry_not_interesting;
 415         struct name_entry entry;
 416         int old_baselen = base->len;
 417
 418         while (tree_entry(tree, &entry)) {
 419                 int te_len = tree_entry_len(&entry);
 420
 421                 if (match != all_entries_interesting) {
 422                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 423                         if (match == all_entries_not_interesting)
 424                                 break;
 425                         if (match == entry_not_interesting)
 426                                 continue;
 427                 }
 428
 429                 strbuf_add(base, entry.path, te_len);
 430
 431                 if (S_ISREG(entry.mode)) {
 432                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len,
 433                                          check_attr ? base->buf + tn_len : NULL);
 434                 }
 435                 else if (S_ISDIR(entry.mode)) {
 436                         enum object_type type;
 437                         struct tree_desc sub;
 438                         void *data;
 439                         unsigned long size;
 440
 441                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 442                         if (!data)
 443                                 die(_("unable to read tree (%s)"),
 444                                     sha1_to_hex(entry.sha1));
 445
 446                         strbuf_addch(base, '/');
 447                         init_tree_desc(&sub, data, size);
 448                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
 449                                          check_attr);
 450                         free(data);
 451                 }
 452                 strbuf_setlen(base, old_baselen);
 453
 454                 if (hit && opt->status_only)
 455                         break;
 456         }
 457         return hit;
 458 }
 459
 460 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 461                        struct object *obj, const char *name)
 462 {
 463         if (obj->type == OBJ_BLOB)
 464                 return grep_sha1(opt, obj->sha1, name, 0, NULL);
 465         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 466                 struct tree_desc tree;
 467                 void *data;
 468                 unsigned long size;
 469                 struct strbuf base;
 470                 int hit, len;
 471
 472                 grep_read_lock();
 473                 data = read_object_with_reference(obj->sha1, tree_type,
 474                                                   &size, NULL);
 475                 grep_read_unlock();
 476
 477                 if (!data)
 478                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 479
 480                 len = name ? strlen(name) : 0;
 481                 strbuf_init(&base, PATH_MAX + len + 1);
 482                 if (len) {
 483                         strbuf_add(&base, name, len);
 484                         strbuf_addch(&base, ':');
 485                 }
 486                 init_tree_desc(&tree, data, size);
 487                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
 488                                 obj->type == OBJ_COMMIT);
 489                 strbuf_release(&base);
 490                 free(data);
 491                 return hit;
 492         }
 493         die(_("unable to grep from object of type %s"), typename(obj->type));
 494 }
 495
 496 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 497                         const struct object_array *list)
 498 {
 499         unsigned int i;
 500         int hit = 0;
 501         const unsigned int nr = list->nr;
 502
 503         for (i = 0; i < nr; i++) {
 504                 struct object *real_obj;
 505                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
 506                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 507                         hit = 1;
 508                         if (opt->status_only)
 509                                 break;
 510                 }
 511         }
 512         return hit;
 513 }
 514
 515 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 516                           int exc_std)
 517 {
 518         struct dir_struct dir;
 519         int i, hit = 0;
 520
 521         memset(&dir, 0, sizeof(dir));
 522         if (exc_std)
 523                 setup_standard_excludes(&dir);
 524
 525         fill_directory(&dir, pathspec->raw);
 526         for (i = 0; i < dir.nr; i++) {
 527                 const char *name = dir.entries[i]->name;
 528                 int namelen = strlen(name);
 529                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 530                         continue;
 531                 hit |= grep_file(opt, dir.entries[i]->name);
 532                 if (hit && opt->status_only)
 533                         break;
 534         }
 535         return hit;
 536 }
 537
 538 static int context_callback(const struct option *opt, const char *arg,
 539                             int unset)
 540 {
 541         struct grep_opt *grep_opt = opt->value;
 542         int value;
 543         const char *endp;
 544
 545         if (unset) {
 546                 grep_opt->pre_context = grep_opt->post_context = 0;
 547                 return 0;
 548         }
 549         value = strtol(arg, (char **)&endp, 10);
 550         if (*endp) {
 551                 return error(_("switch `%c' expects a numerical value"),
 552                              opt->short_name);
 553         }
 554         grep_opt->pre_context = grep_opt->post_context = value;
 555         return 0;
 556 }
 557
 558 static int file_callback(const struct option *opt, const char *arg, int unset)
 559 {
 560         struct grep_opt *grep_opt = opt->value;
 561         int from_stdin = !strcmp(arg, "-");
 562         FILE *patterns;
 563         int lno = 0;
 564         struct strbuf sb = STRBUF_INIT;
 565
 566         patterns = from_stdin ? stdin : fopen(arg, "r");
 567         if (!patterns)
 568                 die_errno(_("cannot open '%s'"), arg);
 569         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 570                 /* ignore empty line like grep does */
 571                 if (sb.len == 0)
 572                         continue;
 573
 574                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 575                                 GREP_PATTERN);
 576         }
 577         if (!from_stdin)
 578                 fclose(patterns);
 579         strbuf_release(&sb);
 580         return 0;
 581 }
 582
 583 static int not_callback(const struct option *opt, const char *arg, int unset)
 584 {
 585         struct grep_opt *grep_opt = opt->value;
 586         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 587         return 0;
 588 }
 589
 590 static int and_callback(const struct option *opt, const char *arg, int unset)
 591 {
 592         struct grep_opt *grep_opt = opt->value;
 593         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 594         return 0;
 595 }
 596
 597 static int open_callback(const struct option *opt, const char *arg, int unset)
 598 {
 599         struct grep_opt *grep_opt = opt->value;
 600         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 601         return 0;
 602 }
 603
 604 static int close_callback(const struct option *opt, const char *arg, int unset)
 605 {
 606         struct grep_opt *grep_opt = opt->value;
 607         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 608         return 0;
 609 }
 610
 611 static int pattern_callback(const struct option *opt, const char *arg,
 612                             int unset)
 613 {
 614         struct grep_opt *grep_opt = opt->value;
 615         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 616         return 0;
 617 }
 618
 619 static int help_callback(const struct option *opt, const char *arg, int unset)
 620 {
 621         return -1;
 622 }
 623
 624 int cmd_grep(int argc, const char **argv, const char *prefix)
 625 {
 626         int hit = 0;
 627         int cached = 0, untracked = 0, opt_exclude = -1;
 628         int seen_dashdash = 0;
 629         int external_grep_allowed__ignored;
 630         const char *show_in_pager = NULL, *default_pager = "dummy";
 631         struct grep_opt opt;
 632         struct object_array list = OBJECT_ARRAY_INIT;
 633         const char **paths = NULL;
 634         struct pathspec pathspec;
 635         struct string_list path_list = STRING_LIST_INIT_NODUP;
 636         int i;
 637         int dummy;
 638         int use_index = 1;
 639         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 640
 641         struct option options[] = {
 642                 OPT_BOOLEAN(0, "cached", &cached,
 643                         N_("search in index instead of in the work tree")),
 644                 OPT_NEGBIT(0, "no-index", &use_index,
 645                          N_("find in contents not managed by git"), 1),
 646                 OPT_BOOLEAN(0, "untracked", &untracked,
 647                         N_("search in both tracked and untracked files")),
 648                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 649                             N_("search also in ignored files"), 1),
 650                 OPT_GROUP(""),
 651                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 652                         N_("show non-matching lines")),
 653                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 654                         N_("case insensitive matching")),
 655                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 656                         N_("match patterns only at word boundaries")),
 657                 OPT_SET_INT('a', "text", &opt.binary,
 658                         N_("process binary files as text"), GREP_BINARY_TEXT),
 659                 OPT_SET_INT('I', NULL, &opt.binary,
 660                         N_("don't match patterns in binary files"),
 661                         GREP_BINARY_NOMATCH),
 662                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 663                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 664                         NULL, 1 },
 665                 OPT_GROUP(""),
 666                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 667                             N_("use extended POSIX regular expressions"),
 668                             GREP_PATTERN_TYPE_ERE),
 669                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 670                             N_("use basic POSIX regular expressions (default)"),
 671                             GREP_PATTERN_TYPE_BRE),
 672                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 673                             N_("interpret patterns as fixed strings"),
 674                             GREP_PATTERN_TYPE_FIXED),
 675                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 676                             N_("use Perl-compatible regular expressions"),
 677                             GREP_PATTERN_TYPE_PCRE),
 678                 OPT_GROUP(""),
 679                 OPT_BOOLEAN('n', "line-number", &opt.linenum, N_("show line numbers")),
 680                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 681                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 682                 OPT_NEGBIT(0, "full-name", &opt.relative,
 683                         N_("show filenames relative to top directory"), 1),
 684                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 685                         N_("show only filenames instead of matching lines")),
 686                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 687                         N_("synonym for --files-with-matches")),
 688                 OPT_BOOLEAN('L', "files-without-match",
 689                         &opt.unmatch_name_only,
 690                         N_("show only the names of files without match")),
 691                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 692                         N_("print NUL after filenames")),
 693                 OPT_BOOLEAN('c', "count", &opt.count,
 694                         N_("show the number of matches instead of matching lines")),
 695                 OPT__COLOR(&opt.color, N_("highlight matches")),
 696                 OPT_BOOLEAN(0, "break", &opt.file_break,
 697                         N_("print empty line between matches from different files")),
 698                 OPT_BOOLEAN(0, "heading", &opt.heading,
 699                         N_("show filename only once above matches from same file")),
 700                 OPT_GROUP(""),
 701                 OPT_CALLBACK('C', "context", &opt, N_("n"),
 702                         N_("show <n> context lines before and after matches"),
 703                         context_callback),
 704                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 705                         N_("show <n> context lines before matches")),
 706                 OPT_INTEGER('A', "after-context", &opt.post_context,
 707                         N_("show <n> context lines after matches")),
 708                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 709                         context_callback),
 710                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 711                         N_("show a line with the function name before matches")),
 712                 OPT_BOOLEAN('W', "function-context", &opt.funcbody,
 713                         N_("show the surrounding function")),
 714                 OPT_GROUP(""),
 715                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
 716                         N_("read patterns from file"), file_callback),
 717                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 718                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 719                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 720                   N_("combine patterns specified with -e"),
 721                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 722                 OPT_BOOLEAN(0, "or", &dummy, ""),
 723                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 724                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 725                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 726                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 727                   open_callback },
 728                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 729                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 730                   close_callback },
 731                 OPT__QUIET(&opt.status_only,
 732                            N_("indicate hit with exit status without output")),
 733                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 734                         N_("show only matches from files that match all patterns")),
 735                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 736                   N_("show parse tree for grep expression"),
 737                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 738                 OPT_GROUP(""),
 739                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 740                         N_("pager"), N_("show matching files in the pager"),
 741                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 742                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
 743                             N_("allow calling of grep(1) (ignored by this build)")),
 744                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, N_("show usage"),
 745                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 746                 OPT_END()
 747         };
 748
 749         /*
 750          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 751          * to show usage information and exit.
 752          */
 753         if (argc == 2 && !strcmp(argv[1], "-h"))
 754                 usage_with_options(grep_usage, options);
 755
 756         init_grep_defaults();
 757         git_config(grep_cmd_config, NULL);
 758         grep_init(&opt, prefix);
 759
 760         /*
 761          * If there is no -- then the paths must exist in the working
 762          * tree.  If there is no explicit pattern specified with -e or
 763          * -f, we take the first unrecognized non option to be the
 764          * pattern, but then what follows it must be zero or more
 765          * valid refs up to the -- (if exists), and then existing
 766          * paths.  If there is an explicit pattern, then the first
 767          * unrecognized non option is the beginning of the refs list
 768          * that continues up to the -- (if exists), and then paths.
 769          */
 770         argc = parse_options(argc, argv, prefix, options, grep_usage,
 771                              PARSE_OPT_KEEP_DASHDASH |
 772                              PARSE_OPT_STOP_AT_NON_OPTION |
 773                              PARSE_OPT_NO_INTERNAL_HELP);
 774         grep_commit_pattern_type(pattern_type_arg, &opt);
 775
 776         if (use_index && !startup_info->have_repository)
 777                 /* die the same way as if we did it at the beginning */
 778                 setup_git_directory();
 779
 780         /*
 781          * skip a -- separator; we know it cannot be
 782          * separating revisions from pathnames if
 783          * we haven't even had any patterns yet
 784          */
 785         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 786                 argv++;
 787                 argc--;
 788         }
 789
 790         /* First unrecognized non-option token */
 791         if (argc > 0 && !opt.pattern_list) {
 792                 append_grep_pattern(&opt, argv[0], "command line", 0,
 793                                     GREP_PATTERN);
 794                 argv++;
 795                 argc--;
 796         }
 797
 798         if (show_in_pager == default_pager)
 799                 show_in_pager = git_pager(1);
 800         if (show_in_pager) {
 801                 opt.color = 0;
 802                 opt.name_only = 1;
 803                 opt.null_following_name = 1;
 804                 opt.output_priv = &path_list;
 805                 opt.output = append_path;
 806                 string_list_append(&path_list, show_in_pager);
 807                 use_threads = 0;
 808         }
 809
 810         if (!opt.pattern_list)
 811                 die(_("no pattern given."));
 812         if (!opt.fixed && opt.ignore_case)
 813                 opt.regflags |= REG_ICASE;
 814
 815         compile_grep_patterns(&opt);
 816
 817         /* Check revs and then paths */
 818         for (i = 0; i < argc; i++) {
 819                 const char *arg = argv[i];
 820                 unsigned char sha1[20];
 821                 /* Is it a rev? */
 822                 if (!get_sha1(arg, sha1)) {
 823                         struct object *object = parse_object(sha1);
 824                         if (!object)
 825                                 die(_("bad object %s"), arg);
 826                         add_object_array(object, arg, &list);
 827                         continue;
 828                 }
 829                 if (!strcmp(arg, "--")) {
 830                         i++;
 831                         seen_dashdash = 1;
 832                 }
 833                 break;
 834         }
 835
 836 #ifndef NO_PTHREADS
 837         if (list.nr || cached || online_cpus() == 1)
 838                 use_threads = 0;
 839 #else
 840         use_threads = 0;
 841 #endif
 842
 843 #ifndef NO_PTHREADS
 844         if (use_threads) {
 845                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 846                     && (opt.pre_context || opt.post_context ||
 847                         opt.file_break || opt.funcbody))
 848                         skip_first_line = 1;
 849                 start_threads(&opt);
 850         }
 851 #endif
 852
 853         /* The rest are paths */
 854         if (!seen_dashdash) {
 855                 int j;
 856                 for (j = i; j < argc; j++)
 857                         verify_filename(prefix, argv[j], j == i);
 858         }
 859
 860         paths = get_pathspec(prefix, argv + i);
 861         init_pathspec(&pathspec, paths);
 862         pathspec.max_depth = opt.max_depth;
 863         pathspec.recursive = 1;
 864
 865         if (show_in_pager && (cached || list.nr))
 866                 die(_("--open-files-in-pager only works on the worktree"));
 867
 868         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 869                 const char *pager = path_list.items[0].string;
 870                 int len = strlen(pager);
 871
 872                 if (len > 4 && is_dir_sep(pager[len - 5]))
 873                         pager += len - 4;
 874
 875                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 876                         struct strbuf buf = STRBUF_INIT;
 877                         strbuf_addf(&buf, "+/%s%s",
 878                                         strcmp("less", pager) ? "" : "*",
 879                                         opt.pattern_list->pattern);
 880                         string_list_append(&path_list, buf.buf);
 881                         strbuf_detach(&buf, NULL);
 882                 }
 883         }
 884
 885         if (!show_in_pager)
 886                 setup_pager();
 887
 888         if (!use_index && (untracked || cached))
 889                 die(_("--cached or --untracked cannot be used with --no-index."));
 890
 891         if (!use_index || untracked) {
 892                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 893                 if (list.nr)
 894                         die(_("--no-index or --untracked cannot be used with revs."));
 895                 hit = grep_directory(&opt, &pathspec, use_exclude);
 896         } else if (0 <= opt_exclude) {
 897                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 898         } else if (!list.nr) {
 899                 if (!cached)
 900                         setup_work_tree();
 901
 902                 hit = grep_cache(&opt, &pathspec, cached);
 903         } else {
 904                 if (cached)
 905                         die(_("both --cached and trees are given."));
 906                 hit = grep_objects(&opt, &pathspec, &list);
 907         }
 908
 909         if (use_threads)
 910                 hit |= wait_all();
 911         if (hit && show_in_pager)
 912                 run_pager(&opt, prefix);
 913         free_grep_patterns(&opt);
 914         return !hit;
 915 }