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 #define GREP_NUM_THREADS_DEFAULT 8
  28 static int num_threads;
  29
  30 #ifndef NO_PTHREADS
  31 static pthread_t *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 (num_threads)
  67                 pthread_mutex_lock(&grep_mutex);
  68 }
  69
  70 static inline void grep_unlock(void)
  71 {
  72         if (num_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         threads = xcalloc(num_threads, sizeof(*threads));
 210         for (i = 0; i < num_threads; i++) {
 211                 int err;
 212                 struct grep_opt *o = grep_opt_dup(opt);
 213                 o->output = strbuf_out;
 214                 o->debug = 0;
 215                 compile_grep_patterns(o);
 216                 err = pthread_create(&threads[i], NULL, run, o);
 217
 218                 if (err)
 219                         die(_("grep: failed to create thread: %s"),
 220                             strerror(err));
 221         }
 222 }
 223
 224 static int wait_all(void)
 225 {
 226         int hit = 0;
 227         int i;
 228
 229         grep_lock();
 230         all_work_added = 1;
 231
 232         /* Wait until all work is done. */
 233         while (todo_done != todo_end)
 234                 pthread_cond_wait(&cond_result, &grep_mutex);
 235
 236         /* Wake up all the consumer threads so they can see that there
 237          * is no more work to do.
 238          */
 239         pthread_cond_broadcast(&cond_add);
 240         grep_unlock();
 241
 242         for (i = 0; i < num_threads; i++) {
 243                 void *h;
 244                 pthread_join(threads[i], &h);
 245                 hit |= (int) (intptr_t) h;
 246         }
 247
 248         free(threads);
 249
 250         pthread_mutex_destroy(&grep_mutex);
 251         pthread_mutex_destroy(&grep_read_mutex);
 252         pthread_mutex_destroy(&grep_attr_mutex);
 253         pthread_cond_destroy(&cond_add);
 254         pthread_cond_destroy(&cond_write);
 255         pthread_cond_destroy(&cond_result);
 256         grep_use_locks = 0;
 257
 258         return hit;
 259 }
 260 #else /* !NO_PTHREADS */
 261
 262 static int wait_all(void)
 263 {
 264         return 0;
 265 }
 266 #endif
 267
 268 static int grep_cmd_config(const char *var, const char *value, void *cb)
 269 {
 270         int st = grep_config(var, value, cb);
 271         if (git_color_default_config(var, value, cb) < 0)
 272                 st = -1;
 273
 274         if (!strcmp(var, "grep.threads")) {
 275                 num_threads = git_config_int(var, value);
 276                 if (num_threads < 0)
 277                         die(_("invalid number of threads specified (%d) for %s"),
 278                             num_threads, var);
 279         }
 280
 281         return st;
 282 }
 283
 284 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 285 {
 286         void *data;
 287
 288         grep_read_lock();
 289         data = read_sha1_file(sha1, type, size);
 290         grep_read_unlock();
 291         return data;
 292 }
 293
 294 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 295                      const char *filename, int tree_name_len,
 296                      const char *path)
 297 {
 298         struct strbuf pathbuf = STRBUF_INIT;
 299
 300         if (opt->relative && opt->prefix_length) {
 301                 quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
 302                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 303         } else {
 304                 strbuf_addstr(&pathbuf, filename);
 305         }
 306
 307 #ifndef NO_PTHREADS
 308         if (num_threads) {
 309                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
 310                 strbuf_release(&pathbuf);
 311                 return 0;
 312         } else
 313 #endif
 314         {
 315                 struct grep_source gs;
 316                 int hit;
 317
 318                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
 319                 strbuf_release(&pathbuf);
 320                 hit = grep_source(opt, &gs);
 321
 322                 grep_source_clear(&gs);
 323                 return hit;
 324         }
 325 }
 326
 327 static int grep_file(struct grep_opt *opt, const char *filename)
 328 {
 329         struct strbuf buf = STRBUF_INIT;
 330
 331         if (opt->relative && opt->prefix_length)
 332                 quote_path_relative(filename, opt->prefix, &buf);
 333         else
 334                 strbuf_addstr(&buf, filename);
 335
 336 #ifndef NO_PTHREADS
 337         if (num_threads) {
 338                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename, filename);
 339                 strbuf_release(&buf);
 340                 return 0;
 341         } else
 342 #endif
 343         {
 344                 struct grep_source gs;
 345                 int hit;
 346
 347                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
 348                 strbuf_release(&buf);
 349                 hit = grep_source(opt, &gs);
 350
 351                 grep_source_clear(&gs);
 352                 return hit;
 353         }
 354 }
 355
 356 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 357 {
 358         struct string_list *path_list = opt->output_priv;
 359
 360         if (len == 1 && *(const char *)data == '\0')
 361                 return;
 362         string_list_append(path_list, xstrndup(data, len));
 363 }
 364
 365 static void run_pager(struct grep_opt *opt, const char *prefix)
 366 {
 367         struct string_list *path_list = opt->output_priv;
 368         struct child_process child = CHILD_PROCESS_INIT;
 369         int i, status;
 370
 371         for (i = 0; i < path_list->nr; i++)
 372                 argv_array_push(&child.args, path_list->items[i].string);
 373         child.dir = prefix;
 374         child.use_shell = 1;
 375
 376         status = run_command(&child);
 377         if (status)
 378                 exit(status);
 379 }
 380
 381 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 382 {
 383         int hit = 0;
 384         int nr;
 385         read_cache();
 386
 387         for (nr = 0; nr < active_nr; nr++) {
 388                 const struct cache_entry *ce = active_cache[nr];
 389                 if (!S_ISREG(ce->ce_mode))
 390                         continue;
 391                 if (!ce_path_match(ce, pathspec, NULL))
 392                         continue;
 393                 /*
 394                  * If CE_VALID is on, we assume worktree file and its cache entry
 395                  * are identical, even if worktree file has been modified, so use
 396                  * cache version instead
 397                  */
 398                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 399                         if (ce_stage(ce) || ce_intent_to_add(ce))
 400                                 continue;
 401                         hit |= grep_sha1(opt, ce->oid.hash, ce->name, 0,
 402                                          ce->name);
 403                 }
 404                 else
 405                         hit |= grep_file(opt, ce->name);
 406                 if (ce_stage(ce)) {
 407                         do {
 408                                 nr++;
 409                         } while (nr < active_nr &&
 410                                  !strcmp(ce->name, active_cache[nr]->name));
 411                         nr--; /* compensate for loop control */
 412                 }
 413                 if (hit && opt->status_only)
 414                         break;
 415         }
 416         return hit;
 417 }
 418
 419 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 420                      struct tree_desc *tree, struct strbuf *base, int tn_len,
 421                      int check_attr)
 422 {
 423         int hit = 0;
 424         enum interesting match = entry_not_interesting;
 425         struct name_entry entry;
 426         int old_baselen = base->len;
 427
 428         while (tree_entry(tree, &entry)) {
 429                 int te_len = tree_entry_len(&entry);
 430
 431                 if (match != all_entries_interesting) {
 432                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 433                         if (match == all_entries_not_interesting)
 434                                 break;
 435                         if (match == entry_not_interesting)
 436                                 continue;
 437                 }
 438
 439                 strbuf_add(base, entry.path, te_len);
 440
 441                 if (S_ISREG(entry.mode)) {
 442                         hit |= grep_sha1(opt, entry.oid->hash, base->buf, tn_len,
 443                                          check_attr ? base->buf + tn_len : NULL);
 444                 }
 445                 else if (S_ISDIR(entry.mode)) {
 446                         enum object_type type;
 447                         struct tree_desc sub;
 448                         void *data;
 449                         unsigned long size;
 450
 451                         data = lock_and_read_sha1_file(entry.oid->hash, &type, &size);
 452                         if (!data)
 453                                 die(_("unable to read tree (%s)"),
 454                                     oid_to_hex(entry.oid));
 455
 456                         strbuf_addch(base, '/');
 457                         init_tree_desc(&sub, data, size);
 458                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
 459                                          check_attr);
 460                         free(data);
 461                 }
 462                 strbuf_setlen(base, old_baselen);
 463
 464                 if (hit && opt->status_only)
 465                         break;
 466         }
 467         return hit;
 468 }
 469
 470 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 471                        struct object *obj, const char *name, const char *path)
 472 {
 473         if (obj->type == OBJ_BLOB)
 474                 return grep_sha1(opt, obj->oid.hash, name, 0, path);
 475         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 476                 struct tree_desc tree;
 477                 void *data;
 478                 unsigned long size;
 479                 struct strbuf base;
 480                 int hit, len;
 481
 482                 grep_read_lock();
 483                 data = read_object_with_reference(obj->oid.hash, tree_type,
 484                                                   &size, NULL);
 485                 grep_read_unlock();
 486
 487                 if (!data)
 488                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
 489
 490                 len = name ? strlen(name) : 0;
 491                 strbuf_init(&base, PATH_MAX + len + 1);
 492                 if (len) {
 493                         strbuf_add(&base, name, len);
 494                         strbuf_addch(&base, ':');
 495                 }
 496                 init_tree_desc(&tree, data, size);
 497                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
 498                                 obj->type == OBJ_COMMIT);
 499                 strbuf_release(&base);
 500                 free(data);
 501                 return hit;
 502         }
 503         die(_("unable to grep from object of type %s"), typename(obj->type));
 504 }
 505
 506 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 507                         const struct object_array *list)
 508 {
 509         unsigned int i;
 510         int hit = 0;
 511         const unsigned int nr = list->nr;
 512
 513         for (i = 0; i < nr; i++) {
 514                 struct object *real_obj;
 515                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
 516                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name, list->objects[i].path)) {
 517                         hit = 1;
 518                         if (opt->status_only)
 519                                 break;
 520                 }
 521         }
 522         return hit;
 523 }
 524
 525 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 526                           int exc_std, int use_index)
 527 {
 528         struct dir_struct dir;
 529         int i, hit = 0;
 530
 531         memset(&dir, 0, sizeof(dir));
 532         if (!use_index)
 533                 dir.flags |= DIR_NO_GITLINKS;
 534         if (exc_std)
 535                 setup_standard_excludes(&dir);
 536
 537         fill_directory(&dir, pathspec);
 538         for (i = 0; i < dir.nr; i++) {
 539                 if (!dir_path_match(dir.entries[i], pathspec, 0, NULL))
 540                         continue;
 541                 hit |= grep_file(opt, dir.entries[i]->name);
 542                 if (hit && opt->status_only)
 543                         break;
 544         }
 545         return hit;
 546 }
 547
 548 static int context_callback(const struct option *opt, const char *arg,
 549                             int unset)
 550 {
 551         struct grep_opt *grep_opt = opt->value;
 552         int value;
 553         const char *endp;
 554
 555         if (unset) {
 556                 grep_opt->pre_context = grep_opt->post_context = 0;
 557                 return 0;
 558         }
 559         value = strtol(arg, (char **)&endp, 10);
 560         if (*endp) {
 561                 return error(_("switch `%c' expects a numerical value"),
 562                              opt->short_name);
 563         }
 564         grep_opt->pre_context = grep_opt->post_context = value;
 565         return 0;
 566 }
 567
 568 static int file_callback(const struct option *opt, const char *arg, int unset)
 569 {
 570         struct grep_opt *grep_opt = opt->value;
 571         int from_stdin = !strcmp(arg, "-");
 572         FILE *patterns;
 573         int lno = 0;
 574         struct strbuf sb = STRBUF_INIT;
 575
 576         patterns = from_stdin ? stdin : fopen(arg, "r");
 577         if (!patterns)
 578                 die_errno(_("cannot open '%s'"), arg);
 579         while (strbuf_getline(&sb, patterns) == 0) {
 580                 /* ignore empty line like grep does */
 581                 if (sb.len == 0)
 582                         continue;
 583
 584                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 585                                 GREP_PATTERN);
 586         }
 587         if (!from_stdin)
 588                 fclose(patterns);
 589         strbuf_release(&sb);
 590         return 0;
 591 }
 592
 593 static int not_callback(const struct option *opt, const char *arg, int unset)
 594 {
 595         struct grep_opt *grep_opt = opt->value;
 596         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 597         return 0;
 598 }
 599
 600 static int and_callback(const struct option *opt, const char *arg, int unset)
 601 {
 602         struct grep_opt *grep_opt = opt->value;
 603         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 604         return 0;
 605 }
 606
 607 static int open_callback(const struct option *opt, const char *arg, int unset)
 608 {
 609         struct grep_opt *grep_opt = opt->value;
 610         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 611         return 0;
 612 }
 613
 614 static int close_callback(const struct option *opt, const char *arg, int unset)
 615 {
 616         struct grep_opt *grep_opt = opt->value;
 617         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 618         return 0;
 619 }
 620
 621 static int pattern_callback(const struct option *opt, const char *arg,
 622                             int unset)
 623 {
 624         struct grep_opt *grep_opt = opt->value;
 625         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 626         return 0;
 627 }
 628
 629 int cmd_grep(int argc, const char **argv, const char *prefix)
 630 {
 631         int hit = 0;
 632         int cached = 0, untracked = 0, opt_exclude = -1;
 633         int seen_dashdash = 0;
 634         int external_grep_allowed__ignored;
 635         const char *show_in_pager = NULL, *default_pager = "dummy";
 636         struct grep_opt opt;
 637         struct object_array list = OBJECT_ARRAY_INIT;
 638         struct pathspec pathspec;
 639         struct string_list path_list = STRING_LIST_INIT_NODUP;
 640         int i;
 641         int dummy;
 642         int use_index = 1;
 643         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 644
 645         struct option options[] = {
 646                 OPT_BOOL(0, "cached", &cached,
 647                         N_("search in index instead of in the work tree")),
 648                 OPT_NEGBIT(0, "no-index", &use_index,
 649                          N_("find in contents not managed by git"), 1),
 650                 OPT_BOOL(0, "untracked", &untracked,
 651                         N_("search in both tracked and untracked files")),
 652                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 653                             N_("ignore files specified via '.gitignore'"), 1),
 654                 OPT_GROUP(""),
 655                 OPT_BOOL('v', "invert-match", &opt.invert,
 656                         N_("show non-matching lines")),
 657                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
 658                         N_("case insensitive matching")),
 659                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
 660                         N_("match patterns only at word boundaries")),
 661                 OPT_SET_INT('a', "text", &opt.binary,
 662                         N_("process binary files as text"), GREP_BINARY_TEXT),
 663                 OPT_SET_INT('I', NULL, &opt.binary,
 664                         N_("don't match patterns in binary files"),
 665                         GREP_BINARY_NOMATCH),
 666                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
 667                          N_("process binary files with textconv filters")),
 668                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 669                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 670                         NULL, 1 },
 671                 OPT_GROUP(""),
 672                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 673                             N_("use extended POSIX regular expressions"),
 674                             GREP_PATTERN_TYPE_ERE),
 675                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 676                             N_("use basic POSIX regular expressions (default)"),
 677                             GREP_PATTERN_TYPE_BRE),
 678                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 679                             N_("interpret patterns as fixed strings"),
 680                             GREP_PATTERN_TYPE_FIXED),
 681                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 682                             N_("use Perl-compatible regular expressions"),
 683                             GREP_PATTERN_TYPE_PCRE),
 684                 OPT_GROUP(""),
 685                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
 686                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 687                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 688                 OPT_NEGBIT(0, "full-name", &opt.relative,
 689                         N_("show filenames relative to top directory"), 1),
 690                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
 691                         N_("show only filenames instead of matching lines")),
 692                 OPT_BOOL(0, "name-only", &opt.name_only,
 693                         N_("synonym for --files-with-matches")),
 694                 OPT_BOOL('L', "files-without-match",
 695                         &opt.unmatch_name_only,
 696                         N_("show only the names of files without match")),
 697                 OPT_BOOL('z', "null", &opt.null_following_name,
 698                         N_("print NUL after filenames")),
 699                 OPT_BOOL('c', "count", &opt.count,
 700                         N_("show the number of matches instead of matching lines")),
 701                 OPT__COLOR(&opt.color, N_("highlight matches")),
 702                 OPT_BOOL(0, "break", &opt.file_break,
 703                         N_("print empty line between matches from different files")),
 704                 OPT_BOOL(0, "heading", &opt.heading,
 705                         N_("show filename only once above matches from same file")),
 706                 OPT_GROUP(""),
 707                 OPT_CALLBACK('C', "context", &opt, N_("n"),
 708                         N_("show <n> context lines before and after matches"),
 709                         context_callback),
 710                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 711                         N_("show <n> context lines before matches")),
 712                 OPT_INTEGER('A', "after-context", &opt.post_context,
 713                         N_("show <n> context lines after matches")),
 714                 OPT_INTEGER(0, "threads", &num_threads,
 715                         N_("use <n> worker threads")),
 716                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 717                         context_callback),
 718                 OPT_BOOL('p', "show-function", &opt.funcname,
 719                         N_("show a line with the function name before matches")),
 720                 OPT_BOOL('W', "function-context", &opt.funcbody,
 721                         N_("show the surrounding function")),
 722                 OPT_GROUP(""),
 723                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
 724                         N_("read patterns from file"), file_callback),
 725                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 726                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 727                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 728                   N_("combine patterns specified with -e"),
 729                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 730                 OPT_BOOL(0, "or", &dummy, ""),
 731                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 732                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 733                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 734                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 735                   open_callback },
 736                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 737                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 738                   close_callback },
 739                 OPT__QUIET(&opt.status_only,
 740                            N_("indicate hit with exit status without output")),
 741                 OPT_BOOL(0, "all-match", &opt.all_match,
 742                         N_("show only matches from files that match all patterns")),
 743                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 744                   N_("show parse tree for grep expression"),
 745                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 746                 OPT_GROUP(""),
 747                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 748                         N_("pager"), N_("show matching files in the pager"),
 749                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 750                 OPT_BOOL(0, "ext-grep", &external_grep_allowed__ignored,
 751                          N_("allow calling of grep(1) (ignored by this build)")),
 752                 OPT_END()
 753         };
 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         grep_commit_pattern_type(pattern_type_arg, &opt);
 773
 774         if (use_index && !startup_info->have_repository) {
 775                 int fallback = 0;
 776                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
 777                 if (fallback)
 778                         use_index = 0;
 779                 else
 780                         /* die the same way as if we did it at the beginning */
 781                         setup_git_directory();
 782         }
 783
 784         /*
 785          * skip a -- separator; we know it cannot be
 786          * separating revisions from pathnames if
 787          * we haven't even had any patterns yet
 788          */
 789         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 790                 argv++;
 791                 argc--;
 792         }
 793
 794         /* First unrecognized non-option token */
 795         if (argc > 0 && !opt.pattern_list) {
 796                 append_grep_pattern(&opt, argv[0], "command line", 0,
 797                                     GREP_PATTERN);
 798                 argv++;
 799                 argc--;
 800         }
 801
 802         if (show_in_pager == default_pager)
 803                 show_in_pager = git_pager(1);
 804         if (show_in_pager) {
 805                 opt.color = 0;
 806                 opt.name_only = 1;
 807                 opt.null_following_name = 1;
 808                 opt.output_priv = &path_list;
 809                 opt.output = append_path;
 810                 string_list_append(&path_list, show_in_pager);
 811         }
 812
 813         if (!opt.pattern_list)
 814                 die(_("no pattern given."));
 815         if (!opt.fixed && opt.ignore_case)
 816                 opt.regflags |= REG_ICASE;
 817
 818         compile_grep_patterns(&opt);
 819
 820         /* Check revs and then paths */
 821         for (i = 0; i < argc; i++) {
 822                 const char *arg = argv[i];
 823                 unsigned char sha1[20];
 824                 struct object_context oc;
 825                 /* Is it a rev? */
 826                 if (!get_sha1_with_context(arg, 0, sha1, &oc)) {
 827                         struct object *object = parse_object_or_die(sha1, arg);
 828                         if (!seen_dashdash)
 829                                 verify_non_filename(prefix, arg);
 830                         add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
 831                         continue;
 832                 }
 833                 if (!strcmp(arg, "--")) {
 834                         i++;
 835                         seen_dashdash = 1;
 836                 }
 837                 break;
 838         }
 839
 840 #ifndef NO_PTHREADS
 841         if (list.nr || cached || show_in_pager)
 842                 num_threads = 0;
 843         else if (num_threads == 0)
 844                 num_threads = GREP_NUM_THREADS_DEFAULT;
 845         else if (num_threads < 0)
 846                 die(_("invalid number of threads specified (%d)"), num_threads);
 847 #else
 848         num_threads = 0;
 849 #endif
 850
 851 #ifndef NO_PTHREADS
 852         if (num_threads) {
 853                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 854                     && (opt.pre_context || opt.post_context ||
 855                         opt.file_break || opt.funcbody))
 856                         skip_first_line = 1;
 857                 start_threads(&opt);
 858         }
 859 #endif
 860
 861         /* The rest are paths */
 862         if (!seen_dashdash) {
 863                 int j;
 864                 for (j = i; j < argc; j++)
 865                         verify_filename(prefix, argv[j], j == i);
 866         }
 867
 868         parse_pathspec(&pathspec, 0,
 869                        PATHSPEC_PREFER_CWD |
 870                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
 871                        prefix, argv + i);
 872         pathspec.max_depth = opt.max_depth;
 873         pathspec.recursive = 1;
 874
 875         if (show_in_pager && (cached || list.nr))
 876                 die(_("--open-files-in-pager only works on the worktree"));
 877
 878         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 879                 const char *pager = path_list.items[0].string;
 880                 int len = strlen(pager);
 881
 882                 if (len > 4 && is_dir_sep(pager[len - 5]))
 883                         pager += len - 4;
 884
 885                 if (opt.ignore_case && !strcmp("less", pager))
 886                         string_list_append(&path_list, "-I");
 887
 888                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 889                         struct strbuf buf = STRBUF_INIT;
 890                         strbuf_addf(&buf, "+/%s%s",
 891                                         strcmp("less", pager) ? "" : "*",
 892                                         opt.pattern_list->pattern);
 893                         string_list_append(&path_list, buf.buf);
 894                         strbuf_detach(&buf, NULL);
 895                 }
 896         }
 897
 898         if (!show_in_pager && !opt.status_only)
 899                 setup_pager();
 900
 901         if (!use_index && (untracked || cached))
 902                 die(_("--cached or --untracked cannot be used with --no-index."));
 903
 904         if (!use_index || untracked) {
 905                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 906                 if (list.nr)
 907                         die(_("--no-index or --untracked cannot be used with revs."));
 908                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
 909         } else if (0 <= opt_exclude) {
 910                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 911         } else if (!list.nr) {
 912                 if (!cached)
 913                         setup_work_tree();
 914
 915                 hit = grep_cache(&opt, &pathspec, cached);
 916         } else {
 917                 if (cached)
 918                         die(_("both --cached and trees are given."));
 919                 hit = grep_objects(&opt, &pathspec, &list);
 920         }
 921
 922         if (num_threads)
 923                 hit |= wait_all();
 924         if (hit && show_in_pager)
 925                 run_pager(&opt, prefix);
 926         free_grep_patterns(&opt);
 927         return !hit;
 928 }