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 #include "pathspec.h"
  21
  22 static char const * const grep_usage[] = {
  23         N_("git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]"),
  24         NULL
  25 };
  26
  27 static int use_threads = 1;
  28
  29 #ifndef NO_PTHREADS
  30 #define THREADS 8
  31 static pthread_t threads[THREADS];
  32
  33 /* We use one producer thread and THREADS consumer
  34  * threads. The producer adds struct work_items to 'todo' and the
  35  * consumers pick work items from the same array.
  36  */
  37 struct work_item {
  38         struct grep_source source;
  39         char done;
  40         struct strbuf out;
  41 };
  42
  43 /* In the range [todo_done, todo_start) in 'todo' we have work_items
  44  * that have been or are processed by a consumer thread. We haven't
  45  * written the result for these to stdout yet.
  46  *
  47  * The work_items in [todo_start, todo_end) are waiting to be picked
  48  * up by a consumer thread.
  49  *
  50  * The ranges are modulo TODO_SIZE.
  51  */
  52 #define TODO_SIZE 128
  53 static struct work_item todo[TODO_SIZE];
  54 static int todo_start;
  55 static int todo_end;
  56 static int todo_done;
  57
  58 /* Has all work items been added? */
  59 static int all_work_added;
  60
  61 /* This lock protects all the variables above. */
  62 static pthread_mutex_t grep_mutex;
  63
  64 static inline void grep_lock(void)
  65 {
  66         if (use_threads)
  67                 pthread_mutex_lock(&grep_mutex);
  68 }
  69
  70 static inline void grep_unlock(void)
  71 {
  72         if (use_threads)
  73                 pthread_mutex_unlock(&grep_mutex);
  74 }
  75
  76 /* Signalled when a new work_item is added to todo. */
  77 static pthread_cond_t cond_add;
  78
  79 /* Signalled when the result from one work_item is written to
  80  * stdout.
  81  */
  82 static pthread_cond_t cond_write;
  83
  84 /* Signalled when we are finished with everything. */
  85 static pthread_cond_t cond_result;
  86
  87 static int skip_first_line;
  88
  89 static void add_work(struct grep_opt *opt, enum grep_source_type type,
  90                      const char *name, const char *path, const void *id)
  91 {
  92         grep_lock();
  93
  94         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
  95                 pthread_cond_wait(&cond_write, &grep_mutex);
  96         }
  97
  98         grep_source_init(&todo[todo_end].source, type, name, path, id);
  99         if (opt->binary != GREP_BINARY_TEXT)
 100                 grep_source_load_driver(&todo[todo_end].source);
 101         todo[todo_end].done = 0;
 102         strbuf_reset(&todo[todo_end].out);
 103         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 104
 105         pthread_cond_signal(&cond_add);
 106         grep_unlock();
 107 }
 108
 109 static struct work_item *get_work(void)
 110 {
 111         struct work_item *ret;
 112
 113         grep_lock();
 114         while (todo_start == todo_end && !all_work_added) {
 115                 pthread_cond_wait(&cond_add, &grep_mutex);
 116         }
 117
 118         if (todo_start == todo_end && all_work_added) {
 119                 ret = NULL;
 120         } else {
 121                 ret = &todo[todo_start];
 122                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 123         }
 124         grep_unlock();
 125         return ret;
 126 }
 127
 128 static void work_done(struct work_item *w)
 129 {
 130         int old_done;
 131
 132         grep_lock();
 133         w->done = 1;
 134         old_done = todo_done;
 135         for(; todo[todo_done].done && todo_done != todo_start;
 136             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 137                 w = &todo[todo_done];
 138                 if (w->out.len) {
 139                         const char *p = w->out.buf;
 140                         size_t len = w->out.len;
 141
 142                         /* Skip the leading hunk mark of the first file. */
 143                         if (skip_first_line) {
 144                                 while (len) {
 145                                         len--;
 146                                         if (*p++ == '\n')
 147                                                 break;
 148                                 }
 149                                 skip_first_line = 0;
 150                         }
 151
 152                         write_or_die(1, p, len);
 153                 }
 154                 grep_source_clear(&w->source);
 155         }
 156
 157         if (old_done != todo_done)
 158                 pthread_cond_signal(&cond_write);
 159
 160         if (all_work_added && todo_done == todo_end)
 161                 pthread_cond_signal(&cond_result);
 162
 163         grep_unlock();
 164 }
 165
 166 static void *run(void *arg)
 167 {
 168         int hit = 0;
 169         struct grep_opt *opt = arg;
 170
 171         while (1) {
 172                 struct work_item *w = get_work();
 173                 if (!w)
 174                         break;
 175
 176                 opt->output_priv = w;
 177                 hit |= grep_source(opt, &w->source);
 178                 grep_source_clear_data(&w->source);
 179                 work_done(w);
 180         }
 181         free_grep_patterns(arg);
 182         free(arg);
 183
 184         return (void*) (intptr_t) hit;
 185 }
 186
 187 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 188 {
 189         struct work_item *w = opt->output_priv;
 190         strbuf_add(&w->out, buf, size);
 191 }
 192
 193 static void start_threads(struct grep_opt *opt)
 194 {
 195         int i;
 196
 197         pthread_mutex_init(&grep_mutex, NULL);
 198         pthread_mutex_init(&grep_read_mutex, NULL);
 199         pthread_mutex_init(&grep_attr_mutex, NULL);
 200         pthread_cond_init(&cond_add, NULL);
 201         pthread_cond_init(&cond_write, NULL);
 202         pthread_cond_init(&cond_result, NULL);
 203         grep_use_locks = 1;
 204
 205         for (i = 0; i < ARRAY_SIZE(todo); i++) {
 206                 strbuf_init(&todo[i].out, 0);
 207         }
 208
 209         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 210                 int err;
 211                 struct grep_opt *o = grep_opt_dup(opt);
 212                 o->output = strbuf_out;
 213                 o->debug = 0;
 214                 compile_grep_patterns(o);
 215                 err = pthread_create(&threads[i], NULL, run, o);
 216
 217                 if (err)
 218                         die(_("grep: failed to create thread: %s"),
 219                             strerror(err));
 220         }
 221 }
 222
 223 static int wait_all(void)
 224 {
 225         int hit = 0;
 226         int i;
 227
 228         grep_lock();
 229         all_work_added = 1;
 230
 231         /* Wait until all work is done. */
 232         while (todo_done != todo_end)
 233                 pthread_cond_wait(&cond_result, &grep_mutex);
 234
 235         /* Wake up all the consumer threads so they can see that there
 236          * is no more work to do.
 237          */
 238         pthread_cond_broadcast(&cond_add);
 239         grep_unlock();
 240
 241         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 242                 void *h;
 243                 pthread_join(threads[i], &h);
 244                 hit |= (int) (intptr_t) h;
 245         }
 246
 247         pthread_mutex_destroy(&grep_mutex);
 248         pthread_mutex_destroy(&grep_read_mutex);
 249         pthread_mutex_destroy(&grep_attr_mutex);
 250         pthread_cond_destroy(&cond_add);
 251         pthread_cond_destroy(&cond_write);
 252         pthread_cond_destroy(&cond_result);
 253         grep_use_locks = 0;
 254
 255         return hit;
 256 }
 257 #else /* !NO_PTHREADS */
 258
 259 static int wait_all(void)
 260 {
 261         return 0;
 262 }
 263 #endif
 264
 265 static int grep_cmd_config(const char *var, const char *value, void *cb)
 266 {
 267         int st = grep_config(var, value, cb);
 268         if (git_color_default_config(var, value, cb) < 0)
 269                 st = -1;
 270         return st;
 271 }
 272
 273 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 274 {
 275         void *data;
 276
 277         grep_read_lock();
 278         data = read_sha1_file(sha1, type, size);
 279         grep_read_unlock();
 280         return data;
 281 }
 282
 283 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 284                      const char *filename, int tree_name_len,
 285                      const char *path)
 286 {
 287         struct strbuf pathbuf = STRBUF_INIT;
 288
 289         if (opt->relative && opt->prefix_length) {
 290                 quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
 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, opt->prefix, &buf);
 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                 const 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);
 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         struct pathspec pathspec;
 634         struct string_list path_list = STRING_LIST_INIT_NODUP;
 635         int i;
 636         int dummy;
 637         int use_index = 1;
 638         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 639
 640         struct option options[] = {
 641                 OPT_BOOL(0, "cached", &cached,
 642                         N_("search in index instead of in the work tree")),
 643                 OPT_NEGBIT(0, "no-index", &use_index,
 644                          N_("find in contents not managed by git"), 1),
 645                 OPT_BOOL(0, "untracked", &untracked,
 646                         N_("search in both tracked and untracked files")),
 647                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 648                             N_("search also in ignored files"), 1),
 649                 OPT_GROUP(""),
 650                 OPT_BOOL('v', "invert-match", &opt.invert,
 651                         N_("show non-matching lines")),
 652                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
 653                         N_("case insensitive matching")),
 654                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
 655                         N_("match patterns only at word boundaries")),
 656                 OPT_SET_INT('a', "text", &opt.binary,
 657                         N_("process binary files as text"), GREP_BINARY_TEXT),
 658                 OPT_SET_INT('I', NULL, &opt.binary,
 659                         N_("don't match patterns in binary files"),
 660                         GREP_BINARY_NOMATCH),
 661                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 662                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 663                         NULL, 1 },
 664                 OPT_GROUP(""),
 665                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 666                             N_("use extended POSIX regular expressions"),
 667                             GREP_PATTERN_TYPE_ERE),
 668                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 669                             N_("use basic POSIX regular expressions (default)"),
 670                             GREP_PATTERN_TYPE_BRE),
 671                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 672                             N_("interpret patterns as fixed strings"),
 673                             GREP_PATTERN_TYPE_FIXED),
 674                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 675                             N_("use Perl-compatible regular expressions"),
 676                             GREP_PATTERN_TYPE_PCRE),
 677                 OPT_GROUP(""),
 678                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
 679                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 680                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 681                 OPT_NEGBIT(0, "full-name", &opt.relative,
 682                         N_("show filenames relative to top directory"), 1),
 683                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
 684                         N_("show only filenames instead of matching lines")),
 685                 OPT_BOOL(0, "name-only", &opt.name_only,
 686                         N_("synonym for --files-with-matches")),
 687                 OPT_BOOL('L', "files-without-match",
 688                         &opt.unmatch_name_only,
 689                         N_("show only the names of files without match")),
 690                 OPT_BOOL('z', "null", &opt.null_following_name,
 691                         N_("print NUL after filenames")),
 692                 OPT_BOOL('c', "count", &opt.count,
 693                         N_("show the number of matches instead of matching lines")),
 694                 OPT__COLOR(&opt.color, N_("highlight matches")),
 695                 OPT_BOOL(0, "break", &opt.file_break,
 696                         N_("print empty line between matches from different files")),
 697                 OPT_BOOL(0, "heading", &opt.heading,
 698                         N_("show filename only once above matches from same file")),
 699                 OPT_GROUP(""),
 700                 OPT_CALLBACK('C', "context", &opt, N_("n"),
 701                         N_("show <n> context lines before and after matches"),
 702                         context_callback),
 703                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 704                         N_("show <n> context lines before matches")),
 705                 OPT_INTEGER('A', "after-context", &opt.post_context,
 706                         N_("show <n> context lines after matches")),
 707                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 708                         context_callback),
 709                 OPT_BOOL('p', "show-function", &opt.funcname,
 710                         N_("show a line with the function name before matches")),
 711                 OPT_BOOL('W', "function-context", &opt.funcbody,
 712                         N_("show the surrounding function")),
 713                 OPT_GROUP(""),
 714                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
 715                         N_("read patterns from file"), file_callback),
 716                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 717                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 718                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 719                   N_("combine patterns specified with -e"),
 720                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 721                 OPT_BOOL(0, "or", &dummy, ""),
 722                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 723                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 724                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 725                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 726                   open_callback },
 727                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 728                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 729                   close_callback },
 730                 OPT__QUIET(&opt.status_only,
 731                            N_("indicate hit with exit status without output")),
 732                 OPT_BOOL(0, "all-match", &opt.all_match,
 733                         N_("show only matches from files that match all patterns")),
 734                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 735                   N_("show parse tree for grep expression"),
 736                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 737                 OPT_GROUP(""),
 738                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 739                         N_("pager"), N_("show matching files in the pager"),
 740                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 741                 OPT_BOOL(0, "ext-grep", &external_grep_allowed__ignored,
 742                          N_("allow calling of grep(1) (ignored by this build)")),
 743                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, N_("show usage"),
 744                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 745                 OPT_END()
 746         };
 747
 748         /*
 749          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 750          * to show usage information and exit.
 751          */
 752         if (argc == 2 && !strcmp(argv[1], "-h"))
 753                 usage_with_options(grep_usage, options);
 754
 755         init_grep_defaults();
 756         git_config(grep_cmd_config, NULL);
 757         grep_init(&opt, prefix);
 758
 759         /*
 760          * If there is no -- then the paths must exist in the working
 761          * tree.  If there is no explicit pattern specified with -e or
 762          * -f, we take the first unrecognized non option to be the
 763          * pattern, but then what follows it must be zero or more
 764          * valid refs up to the -- (if exists), and then existing
 765          * paths.  If there is an explicit pattern, then the first
 766          * unrecognized non option is the beginning of the refs list
 767          * that continues up to the -- (if exists), and then paths.
 768          */
 769         argc = parse_options(argc, argv, prefix, options, grep_usage,
 770                              PARSE_OPT_KEEP_DASHDASH |
 771                              PARSE_OPT_STOP_AT_NON_OPTION |
 772                              PARSE_OPT_NO_INTERNAL_HELP);
 773         grep_commit_pattern_type(pattern_type_arg, &opt);
 774
 775         if (use_index && !startup_info->have_repository)
 776                 /* die the same way as if we did it at the beginning */
 777                 setup_git_directory();
 778
 779         /*
 780          * skip a -- separator; we know it cannot be
 781          * separating revisions from pathnames if
 782          * we haven't even had any patterns yet
 783          */
 784         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 785                 argv++;
 786                 argc--;
 787         }
 788
 789         /* First unrecognized non-option token */
 790         if (argc > 0 && !opt.pattern_list) {
 791                 append_grep_pattern(&opt, argv[0], "command line", 0,
 792                                     GREP_PATTERN);
 793                 argv++;
 794                 argc--;
 795         }
 796
 797         if (show_in_pager == default_pager)
 798                 show_in_pager = git_pager(1);
 799         if (show_in_pager) {
 800                 opt.color = 0;
 801                 opt.name_only = 1;
 802                 opt.null_following_name = 1;
 803                 opt.output_priv = &path_list;
 804                 opt.output = append_path;
 805                 string_list_append(&path_list, show_in_pager);
 806                 use_threads = 0;
 807         }
 808
 809         if (!opt.pattern_list)
 810                 die(_("no pattern given."));
 811         if (!opt.fixed && opt.ignore_case)
 812                 opt.regflags |= REG_ICASE;
 813
 814         compile_grep_patterns(&opt);
 815
 816         /* Check revs and then paths */
 817         for (i = 0; i < argc; i++) {
 818                 const char *arg = argv[i];
 819                 unsigned char sha1[20];
 820                 /* Is it a rev? */
 821                 if (!get_sha1(arg, sha1)) {
 822                         struct object *object = parse_object_or_die(sha1, arg);
 823                         if (!seen_dashdash)
 824                                 verify_non_filename(prefix, arg);
 825                         add_object_array(object, arg, &list);
 826                         continue;
 827                 }
 828                 if (!strcmp(arg, "--")) {
 829                         i++;
 830                         seen_dashdash = 1;
 831                 }
 832                 break;
 833         }
 834
 835 #ifndef NO_PTHREADS
 836         if (list.nr || cached || online_cpus() == 1)
 837                 use_threads = 0;
 838 #else
 839         use_threads = 0;
 840 #endif
 841
 842 #ifndef NO_PTHREADS
 843         if (use_threads) {
 844                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 845                     && (opt.pre_context || opt.post_context ||
 846                         opt.file_break || opt.funcbody))
 847                         skip_first_line = 1;
 848                 start_threads(&opt);
 849         }
 850 #endif
 851
 852         /* The rest are paths */
 853         if (!seen_dashdash) {
 854                 int j;
 855                 for (j = i; j < argc; j++)
 856                         verify_filename(prefix, argv[j], j == i);
 857         }
 858
 859         parse_pathspec(&pathspec, 0,
 860                        PATHSPEC_PREFER_CWD |
 861                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
 862                        prefix, argv + i);
 863         pathspec.max_depth = opt.max_depth;
 864         pathspec.recursive = 1;
 865
 866         if (show_in_pager && (cached || list.nr))
 867                 die(_("--open-files-in-pager only works on the worktree"));
 868
 869         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 870                 const char *pager = path_list.items[0].string;
 871                 int len = strlen(pager);
 872
 873                 if (len > 4 && is_dir_sep(pager[len - 5]))
 874                         pager += len - 4;
 875
 876                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 877                         struct strbuf buf = STRBUF_INIT;
 878                         strbuf_addf(&buf, "+/%s%s",
 879                                         strcmp("less", pager) ? "" : "*",
 880                                         opt.pattern_list->pattern);
 881                         string_list_append(&path_list, buf.buf);
 882                         strbuf_detach(&buf, NULL);
 883                 }
 884         }
 885
 886         if (!show_in_pager)
 887                 setup_pager();
 888
 889         if (!use_index && (untracked || cached))
 890                 die(_("--cached or --untracked cannot be used with --no-index."));
 891
 892         if (!use_index || untracked) {
 893                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 894                 if (list.nr)
 895                         die(_("--no-index or --untracked cannot be used with revs."));
 896                 hit = grep_directory(&opt, &pathspec, use_exclude);
 897         } else if (0 <= opt_exclude) {
 898                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 899         } else if (!list.nr) {
 900                 if (!cached)
 901                         setup_work_tree();
 902
 903                 hit = grep_cache(&opt, &pathspec, cached);
 904         } else {
 905                 if (cached)
 906                         die(_("both --cached and trees are given."));
 907                 hit = grep_objects(&opt, &pathspec, &list);
 908         }
 909
 910         if (use_threads)
 911                 hit |= wait_all();
 912         if (hit && show_in_pager)
 913                 run_pager(&opt, prefix);
 914         free_grep_patterns(&opt);
 915         return !hit;
 916 }