builtin/grep.c

   1 /*
   2  * Builtin "git grep"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "blob.h"
   8 #include "tree.h"
   9 #include "commit.h"
  10 #include "tag.h"
  11 #include "tree-walk.h"
  12 #include "builtin.h"
  13 #include "parse-options.h"
  14 #include "string-list.h"
  15 #include "run-command.h"
  16 #include "userdiff.h"
  17 #include "grep.h"
  18 #include "quote.h"
  19 #include "dir.h"
  20
  21 static char const * const grep_usage[] = {
  22         N_("git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]"),
  23         NULL
  24 };
  25
  26 static int use_threads = 1;
  27
  28 #ifndef NO_PTHREADS
  29 #define THREADS 8
  30 static pthread_t threads[THREADS];
  31
  32 /* We use one producer thread and THREADS consumer
  33  * threads. The producer adds struct work_items to 'todo' and the
  34  * consumers pick work items from the same array.
  35  */
  36 struct work_item {
  37         struct grep_source source;
  38         char done;
  39         struct strbuf out;
  40 };
  41
  42 /* In the range [todo_done, todo_start) in 'todo' we have work_items
  43  * that have been or are processed by a consumer thread. We haven't
  44  * written the result for these to stdout yet.
  45  *
  46  * The work_items in [todo_start, todo_end) are waiting to be picked
  47  * up by a consumer thread.
  48  *
  49  * The ranges are modulo TODO_SIZE.
  50  */
  51 #define TODO_SIZE 128
  52 static struct work_item todo[TODO_SIZE];
  53 static int todo_start;
  54 static int todo_end;
  55 static int todo_done;
  56
  57 /* Has all work items been added? */
  58 static int all_work_added;
  59
  60 /* This lock protects all the variables above. */
  61 static pthread_mutex_t grep_mutex;
  62
  63 static inline void grep_lock(void)
  64 {
  65         if (use_threads)
  66                 pthread_mutex_lock(&grep_mutex);
  67 }
  68
  69 static inline void grep_unlock(void)
  70 {
  71         if (use_threads)
  72                 pthread_mutex_unlock(&grep_mutex);
  73 }
  74
  75 /* Signalled when a new work_item is added to todo. */
  76 static pthread_cond_t cond_add;
  77
  78 /* Signalled when the result from one work_item is written to
  79  * stdout.
  80  */
  81 static pthread_cond_t cond_write;
  82
  83 /* Signalled when we are finished with everything. */
  84 static pthread_cond_t cond_result;
  85
  86 static int skip_first_line;
  87
  88 static void add_work(struct grep_opt *opt, enum grep_source_type type,
  89                      const char *name, const void *id)
  90 {
  91         grep_lock();
  92
  93         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
  94                 pthread_cond_wait(&cond_write, &grep_mutex);
  95         }
  96
  97         grep_source_init(&todo[todo_end].source, type, name, id);
  98         if (opt->binary != GREP_BINARY_TEXT)
  99                 grep_source_load_driver(&todo[todo_end].source);
 100         todo[todo_end].done = 0;
 101         strbuf_reset(&todo[todo_end].out);
 102         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 103
 104         pthread_cond_signal(&cond_add);
 105         grep_unlock();
 106 }
 107
 108 static struct work_item *get_work(void)
 109 {
 110         struct work_item *ret;
 111
 112         grep_lock();
 113         while (todo_start == todo_end && !all_work_added) {
 114                 pthread_cond_wait(&cond_add, &grep_mutex);
 115         }
 116
 117         if (todo_start == todo_end && all_work_added) {
 118                 ret = NULL;
 119         } else {
 120                 ret = &todo[todo_start];
 121                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 122         }
 123         grep_unlock();
 124         return ret;
 125 }
 126
 127 static void work_done(struct work_item *w)
 128 {
 129         int old_done;
 130
 131         grep_lock();
 132         w->done = 1;
 133         old_done = todo_done;
 134         for(; todo[todo_done].done && todo_done != todo_start;
 135             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 136                 w = &todo[todo_done];
 137                 if (w->out.len) {
 138                         const char *p = w->out.buf;
 139                         size_t len = w->out.len;
 140
 141                         /* Skip the leading hunk mark of the first file. */
 142                         if (skip_first_line) {
 143                                 while (len) {
 144                                         len--;
 145                                         if (*p++ == '\n')
 146                                                 break;
 147                                 }
 148                                 skip_first_line = 0;
 149                         }
 150
 151                         write_or_die(1, p, len);
 152                 }
 153                 grep_source_clear(&w->source);
 154         }
 155
 156         if (old_done != todo_done)
 157                 pthread_cond_signal(&cond_write);
 158
 159         if (all_work_added && todo_done == todo_end)
 160                 pthread_cond_signal(&cond_result);
 161
 162         grep_unlock();
 163 }
 164
 165 static void *run(void *arg)
 166 {
 167         int hit = 0;
 168         struct grep_opt *opt = arg;
 169
 170         while (1) {
 171                 struct work_item *w = get_work();
 172                 if (!w)
 173                         break;
 174
 175                 opt->output_priv = w;
 176                 hit |= grep_source(opt, &w->source);
 177                 grep_source_clear_data(&w->source);
 178                 work_done(w);
 179         }
 180         free_grep_patterns(arg);
 181         free(arg);
 182
 183         return (void*) (intptr_t) hit;
 184 }
 185
 186 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 187 {
 188         struct work_item *w = opt->output_priv;
 189         strbuf_add(&w->out, buf, size);
 190 }
 191
 192 static void start_threads(struct grep_opt *opt)
 193 {
 194         int i;
 195
 196         pthread_mutex_init(&grep_mutex, NULL);
 197         pthread_mutex_init(&grep_read_mutex, NULL);
 198         pthread_mutex_init(&grep_attr_mutex, NULL);
 199         pthread_cond_init(&cond_add, NULL);
 200         pthread_cond_init(&cond_write, NULL);
 201         pthread_cond_init(&cond_result, NULL);
 202         grep_use_locks = 1;
 203
 204         for (i = 0; i < ARRAY_SIZE(todo); i++) {
 205                 strbuf_init(&todo[i].out, 0);
 206         }
 207
 208         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 209                 int err;
 210                 struct grep_opt *o = grep_opt_dup(opt);
 211                 o->output = strbuf_out;
 212                 o->debug = 0;
 213                 compile_grep_patterns(o);
 214                 err = pthread_create(&threads[i], NULL, run, o);
 215
 216                 if (err)
 217                         die(_("grep: failed to create thread: %s"),
 218                             strerror(err));
 219         }
 220 }
 221
 222 static int wait_all(void)
 223 {
 224         int hit = 0;
 225         int i;
 226
 227         grep_lock();
 228         all_work_added = 1;
 229
 230         /* Wait until all work is done. */
 231         while (todo_done != todo_end)
 232                 pthread_cond_wait(&cond_result, &grep_mutex);
 233
 234         /* Wake up all the consumer threads so they can see that there
 235          * is no more work to do.
 236          */
 237         pthread_cond_broadcast(&cond_add);
 238         grep_unlock();
 239
 240         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 241                 void *h;
 242                 pthread_join(threads[i], &h);
 243                 hit |= (int) (intptr_t) h;
 244         }
 245
 246         pthread_mutex_destroy(&grep_mutex);
 247         pthread_mutex_destroy(&grep_read_mutex);
 248         pthread_mutex_destroy(&grep_attr_mutex);
 249         pthread_cond_destroy(&cond_add);
 250         pthread_cond_destroy(&cond_write);
 251         pthread_cond_destroy(&cond_result);
 252         grep_use_locks = 0;
 253
 254         return hit;
 255 }
 256 #else /* !NO_PTHREADS */
 257
 258 static int wait_all(void)
 259 {
 260         return 0;
 261 }
 262 #endif
 263
 264 static void grep_pattern_type_options(const int pattern_type, struct grep_opt *opt)
 265 {
 266         switch (pattern_type) {
 267         case GREP_PATTERN_TYPE_UNSPECIFIED:
 268                 /* fall through */
 269
 270         case GREP_PATTERN_TYPE_BRE:
 271                 opt->fixed = 0;
 272                 opt->pcre = 0;
 273                 opt->regflags &= ~REG_EXTENDED;
 274                 break;
 275
 276         case GREP_PATTERN_TYPE_ERE:
 277                 opt->fixed = 0;
 278                 opt->pcre = 0;
 279                 opt->regflags |= REG_EXTENDED;
 280                 break;
 281
 282         case GREP_PATTERN_TYPE_FIXED:
 283                 opt->fixed = 1;
 284                 opt->pcre = 0;
 285                 opt->regflags &= ~REG_EXTENDED;
 286                 break;
 287
 288         case GREP_PATTERN_TYPE_PCRE:
 289                 opt->fixed = 0;
 290                 opt->pcre = 1;
 291                 opt->regflags &= ~REG_EXTENDED;
 292                 break;
 293         }
 294 }
 295
 296 static int grep_cmd_config(const char *var, const char *value, void *cb)
 297 {
 298         int st = grep_config(var, value, cb);
 299         if (git_color_default_config(var, value, cb) < 0)
 300                 st = -1;
 301         return st;
 302 }
 303
 304 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 305 {
 306         void *data;
 307
 308         grep_read_lock();
 309         data = read_sha1_file(sha1, type, size);
 310         grep_read_unlock();
 311         return data;
 312 }
 313
 314 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 315                      const char *filename, int tree_name_len)
 316 {
 317         struct strbuf pathbuf = STRBUF_INIT;
 318
 319         if (opt->relative && opt->prefix_length) {
 320                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
 321                                     opt->prefix);
 322                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 323         } else {
 324                 strbuf_addstr(&pathbuf, filename);
 325         }
 326
 327 #ifndef NO_PTHREADS
 328         if (use_threads) {
 329                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 330                 strbuf_release(&pathbuf);
 331                 return 0;
 332         } else
 333 #endif
 334         {
 335                 struct grep_source gs;
 336                 int hit;
 337
 338                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 339                 strbuf_release(&pathbuf);
 340                 hit = grep_source(opt, &gs);
 341
 342                 grep_source_clear(&gs);
 343                 return hit;
 344         }
 345 }
 346
 347 static int grep_file(struct grep_opt *opt, const char *filename)
 348 {
 349         struct strbuf buf = STRBUF_INIT;
 350
 351         if (opt->relative && opt->prefix_length)
 352                 quote_path_relative(filename, -1, &buf, opt->prefix);
 353         else
 354                 strbuf_addstr(&buf, filename);
 355
 356 #ifndef NO_PTHREADS
 357         if (use_threads) {
 358                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename);
 359                 strbuf_release(&buf);
 360                 return 0;
 361         } else
 362 #endif
 363         {
 364                 struct grep_source gs;
 365                 int hit;
 366
 367                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename);
 368                 strbuf_release(&buf);
 369                 hit = grep_source(opt, &gs);
 370
 371                 grep_source_clear(&gs);
 372                 return hit;
 373         }
 374 }
 375
 376 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 377 {
 378         struct string_list *path_list = opt->output_priv;
 379
 380         if (len == 1 && *(const char *)data == '\0')
 381                 return;
 382         string_list_append(path_list, xstrndup(data, len));
 383 }
 384
 385 static void run_pager(struct grep_opt *opt, const char *prefix)
 386 {
 387         struct string_list *path_list = opt->output_priv;
 388         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 389         int i, status;
 390
 391         for (i = 0; i < path_list->nr; i++)
 392                 argv[i] = path_list->items[i].string;
 393         argv[path_list->nr] = NULL;
 394
 395         if (prefix && chdir(prefix))
 396                 die(_("Failed to chdir: %s"), prefix);
 397         status = run_command_v_opt(argv, RUN_USING_SHELL);
 398         if (status)
 399                 exit(status);
 400         free(argv);
 401 }
 402
 403 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 404 {
 405         int hit = 0;
 406         int nr;
 407         read_cache();
 408
 409         for (nr = 0; nr < active_nr; nr++) {
 410                 struct cache_entry *ce = active_cache[nr];
 411                 if (!S_ISREG(ce->ce_mode))
 412                         continue;
 413                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 414                         continue;
 415                 /*
 416                  * If CE_VALID is on, we assume worktree file and its cache entry
 417                  * are identical, even if worktree file has been modified, so use
 418                  * cache version instead
 419                  */
 420                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 421                         if (ce_stage(ce))
 422                                 continue;
 423                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 424                 }
 425                 else
 426                         hit |= grep_file(opt, ce->name);
 427                 if (ce_stage(ce)) {
 428                         do {
 429                                 nr++;
 430                         } while (nr < active_nr &&
 431                                  !strcmp(ce->name, active_cache[nr]->name));
 432                         nr--; /* compensate for loop control */
 433                 }
 434                 if (hit && opt->status_only)
 435                         break;
 436         }
 437         return hit;
 438 }
 439
 440 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 441                      struct tree_desc *tree, struct strbuf *base, int tn_len)
 442 {
 443         int hit = 0;
 444         enum interesting match = entry_not_interesting;
 445         struct name_entry entry;
 446         int old_baselen = base->len;
 447
 448         while (tree_entry(tree, &entry)) {
 449                 int te_len = tree_entry_len(&entry);
 450
 451                 if (match != all_entries_interesting) {
 452                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 453                         if (match == all_entries_not_interesting)
 454                                 break;
 455                         if (match == entry_not_interesting)
 456                                 continue;
 457                 }
 458
 459                 strbuf_add(base, entry.path, te_len);
 460
 461                 if (S_ISREG(entry.mode)) {
 462                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
 463                 }
 464                 else if (S_ISDIR(entry.mode)) {
 465                         enum object_type type;
 466                         struct tree_desc sub;
 467                         void *data;
 468                         unsigned long size;
 469
 470                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 471                         if (!data)
 472                                 die(_("unable to read tree (%s)"),
 473                                     sha1_to_hex(entry.sha1));
 474
 475                         strbuf_addch(base, '/');
 476                         init_tree_desc(&sub, data, size);
 477                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
 478                         free(data);
 479                 }
 480                 strbuf_setlen(base, old_baselen);
 481
 482                 if (hit && opt->status_only)
 483                         break;
 484         }
 485         return hit;
 486 }
 487
 488 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 489                        struct object *obj, const char *name)
 490 {
 491         if (obj->type == OBJ_BLOB)
 492                 return grep_sha1(opt, obj->sha1, name, 0);
 493         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 494                 struct tree_desc tree;
 495                 void *data;
 496                 unsigned long size;
 497                 struct strbuf base;
 498                 int hit, len;
 499
 500                 grep_read_lock();
 501                 data = read_object_with_reference(obj->sha1, tree_type,
 502                                                   &size, NULL);
 503                 grep_read_unlock();
 504
 505                 if (!data)
 506                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 507
 508                 len = name ? strlen(name) : 0;
 509                 strbuf_init(&base, PATH_MAX + len + 1);
 510                 if (len) {
 511                         strbuf_add(&base, name, len);
 512                         strbuf_addch(&base, ':');
 513                 }
 514                 init_tree_desc(&tree, data, size);
 515                 hit = grep_tree(opt, pathspec, &tree, &base, base.len);
 516                 strbuf_release(&base);
 517                 free(data);
 518                 return hit;
 519         }
 520         die(_("unable to grep from object of type %s"), typename(obj->type));
 521 }
 522
 523 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 524                         const struct object_array *list)
 525 {
 526         unsigned int i;
 527         int hit = 0;
 528         const unsigned int nr = list->nr;
 529
 530         for (i = 0; i < nr; i++) {
 531                 struct object *real_obj;
 532                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
 533                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 534                         hit = 1;
 535                         if (opt->status_only)
 536                                 break;
 537                 }
 538         }
 539         return hit;
 540 }
 541
 542 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 543                           int exc_std)
 544 {
 545         struct dir_struct dir;
 546         int i, hit = 0;
 547
 548         memset(&dir, 0, sizeof(dir));
 549         if (exc_std)
 550                 setup_standard_excludes(&dir);
 551
 552         fill_directory(&dir, pathspec->raw);
 553         for (i = 0; i < dir.nr; i++) {
 554                 const char *name = dir.entries[i]->name;
 555                 int namelen = strlen(name);
 556                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 557                         continue;
 558                 hit |= grep_file(opt, dir.entries[i]->name);
 559                 if (hit && opt->status_only)
 560                         break;
 561         }
 562         return hit;
 563 }
 564
 565 static int context_callback(const struct option *opt, const char *arg,
 566                             int unset)
 567 {
 568         struct grep_opt *grep_opt = opt->value;
 569         int value;
 570         const char *endp;
 571
 572         if (unset) {
 573                 grep_opt->pre_context = grep_opt->post_context = 0;
 574                 return 0;
 575         }
 576         value = strtol(arg, (char **)&endp, 10);
 577         if (*endp) {
 578                 return error(_("switch `%c' expects a numerical value"),
 579                              opt->short_name);
 580         }
 581         grep_opt->pre_context = grep_opt->post_context = value;
 582         return 0;
 583 }
 584
 585 static int file_callback(const struct option *opt, const char *arg, int unset)
 586 {
 587         struct grep_opt *grep_opt = opt->value;
 588         int from_stdin = !strcmp(arg, "-");
 589         FILE *patterns;
 590         int lno = 0;
 591         struct strbuf sb = STRBUF_INIT;
 592
 593         patterns = from_stdin ? stdin : fopen(arg, "r");
 594         if (!patterns)
 595                 die_errno(_("cannot open '%s'"), arg);
 596         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 597                 /* ignore empty line like grep does */
 598                 if (sb.len == 0)
 599                         continue;
 600
 601                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 602                                 GREP_PATTERN);
 603         }
 604         if (!from_stdin)
 605                 fclose(patterns);
 606         strbuf_release(&sb);
 607         return 0;
 608 }
 609
 610 static int not_callback(const struct option *opt, const char *arg, int unset)
 611 {
 612         struct grep_opt *grep_opt = opt->value;
 613         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 614         return 0;
 615 }
 616
 617 static int and_callback(const struct option *opt, const char *arg, int unset)
 618 {
 619         struct grep_opt *grep_opt = opt->value;
 620         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 621         return 0;
 622 }
 623
 624 static int open_callback(const struct option *opt, const char *arg, int unset)
 625 {
 626         struct grep_opt *grep_opt = opt->value;
 627         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 628         return 0;
 629 }
 630
 631 static int close_callback(const struct option *opt, const char *arg, int unset)
 632 {
 633         struct grep_opt *grep_opt = opt->value;
 634         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 635         return 0;
 636 }
 637
 638 static int pattern_callback(const struct option *opt, const char *arg,
 639                             int unset)
 640 {
 641         struct grep_opt *grep_opt = opt->value;
 642         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 643         return 0;
 644 }
 645
 646 static int help_callback(const struct option *opt, const char *arg, int unset)
 647 {
 648         return -1;
 649 }
 650
 651 int cmd_grep(int argc, const char **argv, const char *prefix)
 652 {
 653         int hit = 0;
 654         int cached = 0, untracked = 0, opt_exclude = -1;
 655         int seen_dashdash = 0;
 656         int external_grep_allowed__ignored;
 657         const char *show_in_pager = NULL, *default_pager = "dummy";
 658         struct grep_opt opt;
 659         struct object_array list = OBJECT_ARRAY_INIT;
 660         const char **paths = NULL;
 661         struct pathspec pathspec;
 662         struct string_list path_list = STRING_LIST_INIT_NODUP;
 663         int i;
 664         int dummy;
 665         int use_index = 1;
 666         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 667
 668         struct option options[] = {
 669                 OPT_BOOLEAN(0, "cached", &cached,
 670                         N_("search in index instead of in the work tree")),
 671                 OPT_NEGBIT(0, "no-index", &use_index,
 672                          N_("find in contents not managed by git"), 1),
 673                 OPT_BOOLEAN(0, "untracked", &untracked,
 674                         N_("search in both tracked and untracked files")),
 675                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 676                             N_("search also in ignored files"), 1),
 677                 OPT_GROUP(""),
 678                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 679                         N_("show non-matching lines")),
 680                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 681                         N_("case insensitive matching")),
 682                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 683                         N_("match patterns only at word boundaries")),
 684                 OPT_SET_INT('a', "text", &opt.binary,
 685                         N_("process binary files as text"), GREP_BINARY_TEXT),
 686                 OPT_SET_INT('I', NULL, &opt.binary,
 687                         N_("don't match patterns in binary files"),
 688                         GREP_BINARY_NOMATCH),
 689                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 690                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 691                         NULL, 1 },
 692                 OPT_GROUP(""),
 693                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 694                             N_("use extended POSIX regular expressions"),
 695                             GREP_PATTERN_TYPE_ERE),
 696                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 697                             N_("use basic POSIX regular expressions (default)"),
 698                             GREP_PATTERN_TYPE_BRE),
 699                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 700                             N_("interpret patterns as fixed strings"),
 701                             GREP_PATTERN_TYPE_FIXED),
 702                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 703                             N_("use Perl-compatible regular expressions"),
 704                             GREP_PATTERN_TYPE_PCRE),
 705                 OPT_GROUP(""),
 706                 OPT_BOOLEAN('n', "line-number", &opt.linenum, N_("show line numbers")),
 707                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 708                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 709                 OPT_NEGBIT(0, "full-name", &opt.relative,
 710                         N_("show filenames relative to top directory"), 1),
 711                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 712                         N_("show only filenames instead of matching lines")),
 713                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 714                         N_("synonym for --files-with-matches")),
 715                 OPT_BOOLEAN('L', "files-without-match",
 716                         &opt.unmatch_name_only,
 717                         N_("show only the names of files without match")),
 718                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 719                         N_("print NUL after filenames")),
 720                 OPT_BOOLEAN('c', "count", &opt.count,
 721                         N_("show the number of matches instead of matching lines")),
 722                 OPT__COLOR(&opt.color, N_("highlight matches")),
 723                 OPT_BOOLEAN(0, "break", &opt.file_break,
 724                         N_("print empty line between matches from different files")),
 725                 OPT_BOOLEAN(0, "heading", &opt.heading,
 726                         N_("show filename only once above matches from same file")),
 727                 OPT_GROUP(""),
 728                 OPT_CALLBACK('C', "context", &opt, N_("n"),
 729                         N_("show <n> context lines before and after matches"),
 730                         context_callback),
 731                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 732                         N_("show <n> context lines before matches")),
 733                 OPT_INTEGER('A', "after-context", &opt.post_context,
 734                         N_("show <n> context lines after matches")),
 735                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 736                         context_callback),
 737                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 738                         N_("show a line with the function name before matches")),
 739                 OPT_BOOLEAN('W', "function-context", &opt.funcbody,
 740                         N_("show the surrounding function")),
 741                 OPT_GROUP(""),
 742                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
 743                         N_("read patterns from file"), file_callback),
 744                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 745                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 746                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 747                   N_("combine patterns specified with -e"),
 748                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 749                 OPT_BOOLEAN(0, "or", &dummy, ""),
 750                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 751                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 752                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 753                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 754                   open_callback },
 755                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 756                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 757                   close_callback },
 758                 OPT__QUIET(&opt.status_only,
 759                            N_("indicate hit with exit status without output")),
 760                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 761                         N_("show only matches from files that match all patterns")),
 762                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 763                   N_("show parse tree for grep expression"),
 764                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 765                 OPT_GROUP(""),
 766                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 767                         N_("pager"), N_("show matching files in the pager"),
 768                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 769                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
 770                             N_("allow calling of grep(1) (ignored by this build)")),
 771                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, N_("show usage"),
 772                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 773                 OPT_END()
 774         };
 775
 776         /*
 777          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 778          * to show usage information and exit.
 779          */
 780         if (argc == 2 && !strcmp(argv[1], "-h"))
 781                 usage_with_options(grep_usage, options);
 782
 783         init_grep_defaults();
 784         git_config(grep_cmd_config, NULL);
 785         grep_init(&opt, prefix);
 786
 787         /*
 788          * If there is no -- then the paths must exist in the working
 789          * tree.  If there is no explicit pattern specified with -e or
 790          * -f, we take the first unrecognized non option to be the
 791          * pattern, but then what follows it must be zero or more
 792          * valid refs up to the -- (if exists), and then existing
 793          * paths.  If there is an explicit pattern, then the first
 794          * unrecognized non option is the beginning of the refs list
 795          * that continues up to the -- (if exists), and then paths.
 796          */
 797         argc = parse_options(argc, argv, prefix, options, grep_usage,
 798                              PARSE_OPT_KEEP_DASHDASH |
 799                              PARSE_OPT_STOP_AT_NON_OPTION |
 800                              PARSE_OPT_NO_INTERNAL_HELP);
 801
 802         if (pattern_type_arg != GREP_PATTERN_TYPE_UNSPECIFIED)
 803                 grep_pattern_type_options(pattern_type_arg, &opt);
 804         else if (opt.pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 805                 grep_pattern_type_options(opt.pattern_type_option, &opt);
 806         else if (opt.extended_regexp_option)
 807                 grep_pattern_type_options(GREP_PATTERN_TYPE_ERE, &opt);
 808
 809         if (use_index && !startup_info->have_repository)
 810                 /* die the same way as if we did it at the beginning */
 811                 setup_git_directory();
 812
 813         /*
 814          * skip a -- separator; we know it cannot be
 815          * separating revisions from pathnames if
 816          * we haven't even had any patterns yet
 817          */
 818         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 819                 argv++;
 820                 argc--;
 821         }
 822
 823         /* First unrecognized non-option token */
 824         if (argc > 0 && !opt.pattern_list) {
 825                 append_grep_pattern(&opt, argv[0], "command line", 0,
 826                                     GREP_PATTERN);
 827                 argv++;
 828                 argc--;
 829         }
 830
 831         if (show_in_pager == default_pager)
 832                 show_in_pager = git_pager(1);
 833         if (show_in_pager) {
 834                 opt.color = 0;
 835                 opt.name_only = 1;
 836                 opt.null_following_name = 1;
 837                 opt.output_priv = &path_list;
 838                 opt.output = append_path;
 839                 string_list_append(&path_list, show_in_pager);
 840                 use_threads = 0;
 841         }
 842
 843         if (!opt.pattern_list)
 844                 die(_("no pattern given."));
 845         if (!opt.fixed && opt.ignore_case)
 846                 opt.regflags |= REG_ICASE;
 847
 848         compile_grep_patterns(&opt);
 849
 850         /* Check revs and then paths */
 851         for (i = 0; i < argc; i++) {
 852                 const char *arg = argv[i];
 853                 unsigned char sha1[20];
 854                 /* Is it a rev? */
 855                 if (!get_sha1(arg, sha1)) {
 856                         struct object *object = parse_object(sha1);
 857                         if (!object)
 858                                 die(_("bad object %s"), arg);
 859                         add_object_array(object, arg, &list);
 860                         continue;
 861                 }
 862                 if (!strcmp(arg, "--")) {
 863                         i++;
 864                         seen_dashdash = 1;
 865                 }
 866                 break;
 867         }
 868
 869 #ifndef NO_PTHREADS
 870         if (list.nr || cached || online_cpus() == 1)
 871                 use_threads = 0;
 872 #else
 873         use_threads = 0;
 874 #endif
 875
 876 #ifndef NO_PTHREADS
 877         if (use_threads) {
 878                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 879                     && (opt.pre_context || opt.post_context ||
 880                         opt.file_break || opt.funcbody))
 881                         skip_first_line = 1;
 882                 start_threads(&opt);
 883         }
 884 #endif
 885
 886         /* The rest are paths */
 887         if (!seen_dashdash) {
 888                 int j;
 889                 for (j = i; j < argc; j++)
 890                         verify_filename(prefix, argv[j], j == i);
 891         }
 892
 893         paths = get_pathspec(prefix, argv + i);
 894         init_pathspec(&pathspec, paths);
 895         pathspec.max_depth = opt.max_depth;
 896         pathspec.recursive = 1;
 897
 898         if (show_in_pager && (cached || list.nr))
 899                 die(_("--open-files-in-pager only works on the worktree"));
 900
 901         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 902                 const char *pager = path_list.items[0].string;
 903                 int len = strlen(pager);
 904
 905                 if (len > 4 && is_dir_sep(pager[len - 5]))
 906                         pager += len - 4;
 907
 908                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 909                         struct strbuf buf = STRBUF_INIT;
 910                         strbuf_addf(&buf, "+/%s%s",
 911                                         strcmp("less", pager) ? "" : "*",
 912                                         opt.pattern_list->pattern);
 913                         string_list_append(&path_list, buf.buf);
 914                         strbuf_detach(&buf, NULL);
 915                 }
 916         }
 917
 918         if (!show_in_pager)
 919                 setup_pager();
 920
 921         if (!use_index && (untracked || cached))
 922                 die(_("--cached or --untracked cannot be used with --no-index."));
 923
 924         if (!use_index || untracked) {
 925                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 926                 if (list.nr)
 927                         die(_("--no-index or --untracked cannot be used with revs."));
 928                 hit = grep_directory(&opt, &pathspec, use_exclude);
 929         } else if (0 <= opt_exclude) {
 930                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 931         } else if (!list.nr) {
 932                 if (!cached)
 933                         setup_work_tree();
 934
 935                 hit = grep_cache(&opt, &pathspec, cached);
 936         } else {
 937                 if (cached)
 938                         die(_("both --cached and trees are given."));
 939                 hit = grep_objects(&opt, &pathspec, &list);
 940         }
 941
 942         if (use_threads)
 943                 hit |= wait_all();
 944         if (hit && show_in_pager)
 945                 run_pager(&opt, prefix);
 946         free_grep_patterns(&opt);
 947         return !hit;
 948 }