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         "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                 compile_grep_patterns(o);
 213                 err = pthread_create(&threads[i], NULL, run, o);
 214
 215                 if (err)
 216                         die(_("grep: failed to create thread: %s"),
 217                             strerror(err));
 218         }
 219 }
 220
 221 static int wait_all(void)
 222 {
 223         int hit = 0;
 224         int i;
 225
 226         grep_lock();
 227         all_work_added = 1;
 228
 229         /* Wait until all work is done. */
 230         while (todo_done != todo_end)
 231                 pthread_cond_wait(&cond_result, &grep_mutex);
 232
 233         /* Wake up all the consumer threads so they can see that there
 234          * is no more work to do.
 235          */
 236         pthread_cond_broadcast(&cond_add);
 237         grep_unlock();
 238
 239         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 240                 void *h;
 241                 pthread_join(threads[i], &h);
 242                 hit |= (int) (intptr_t) h;
 243         }
 244
 245         pthread_mutex_destroy(&grep_mutex);
 246         pthread_mutex_destroy(&grep_read_mutex);
 247         pthread_mutex_destroy(&grep_attr_mutex);
 248         pthread_cond_destroy(&cond_add);
 249         pthread_cond_destroy(&cond_write);
 250         pthread_cond_destroy(&cond_result);
 251         grep_use_locks = 0;
 252
 253         return hit;
 254 }
 255 #else /* !NO_PTHREADS */
 256
 257 static int wait_all(void)
 258 {
 259         return 0;
 260 }
 261 #endif
 262
 263 static int grep_config(const char *var, const char *value, void *cb)
 264 {
 265         struct grep_opt *opt = cb;
 266         char *color = NULL;
 267
 268         switch (userdiff_config(var, value)) {
 269         case 0: break;
 270         case -1: return -1;
 271         default: return 0;
 272         }
 273
 274         if (!strcmp(var, "grep.extendedregexp")) {
 275                 if (git_config_bool(var, value))
 276                         opt->regflags |= REG_EXTENDED;
 277                 else
 278                         opt->regflags &= ~REG_EXTENDED;
 279                 return 0;
 280         }
 281
 282         if (!strcmp(var, "grep.linenumber")) {
 283                 opt->linenum = git_config_bool(var, value);
 284                 return 0;
 285         }
 286
 287         if (!strcmp(var, "color.grep"))
 288                 opt->color = git_config_colorbool(var, value);
 289         else if (!strcmp(var, "color.grep.context"))
 290                 color = opt->color_context;
 291         else if (!strcmp(var, "color.grep.filename"))
 292                 color = opt->color_filename;
 293         else if (!strcmp(var, "color.grep.function"))
 294                 color = opt->color_function;
 295         else if (!strcmp(var, "color.grep.linenumber"))
 296                 color = opt->color_lineno;
 297         else if (!strcmp(var, "color.grep.match"))
 298                 color = opt->color_match;
 299         else if (!strcmp(var, "color.grep.selected"))
 300                 color = opt->color_selected;
 301         else if (!strcmp(var, "color.grep.separator"))
 302                 color = opt->color_sep;
 303         else
 304                 return git_color_default_config(var, value, cb);
 305         if (color) {
 306                 if (!value)
 307                         return config_error_nonbool(var);
 308                 color_parse(value, var, color);
 309         }
 310         return 0;
 311 }
 312
 313 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 314 {
 315         void *data;
 316
 317         grep_read_lock();
 318         data = read_sha1_file(sha1, type, size);
 319         grep_read_unlock();
 320         return data;
 321 }
 322
 323 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 324                      const char *filename, int tree_name_len)
 325 {
 326         struct strbuf pathbuf = STRBUF_INIT;
 327
 328         if (opt->relative && opt->prefix_length) {
 329                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
 330                                     opt->prefix);
 331                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 332         } else {
 333                 strbuf_addstr(&pathbuf, filename);
 334         }
 335
 336 #ifndef NO_PTHREADS
 337         if (use_threads) {
 338                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 339                 strbuf_release(&pathbuf);
 340                 return 0;
 341         } else
 342 #endif
 343         {
 344                 struct grep_source gs;
 345                 int hit;
 346
 347                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 348                 strbuf_release(&pathbuf);
 349                 hit = grep_source(opt, &gs);
 350
 351                 grep_source_clear(&gs);
 352                 return hit;
 353         }
 354 }
 355
 356 static int grep_file(struct grep_opt *opt, const char *filename)
 357 {
 358         struct strbuf buf = STRBUF_INIT;
 359
 360         if (opt->relative && opt->prefix_length)
 361                 quote_path_relative(filename, -1, &buf, opt->prefix);
 362         else
 363                 strbuf_addstr(&buf, filename);
 364
 365 #ifndef NO_PTHREADS
 366         if (use_threads) {
 367                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename);
 368                 strbuf_release(&buf);
 369                 return 0;
 370         } else
 371 #endif
 372         {
 373                 struct grep_source gs;
 374                 int hit;
 375
 376                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename);
 377                 strbuf_release(&buf);
 378                 hit = grep_source(opt, &gs);
 379
 380                 grep_source_clear(&gs);
 381                 return hit;
 382         }
 383 }
 384
 385 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 386 {
 387         struct string_list *path_list = opt->output_priv;
 388
 389         if (len == 1 && *(const char *)data == '\0')
 390                 return;
 391         string_list_append(path_list, xstrndup(data, len));
 392 }
 393
 394 static void run_pager(struct grep_opt *opt, const char *prefix)
 395 {
 396         struct string_list *path_list = opt->output_priv;
 397         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 398         int i, status;
 399
 400         for (i = 0; i < path_list->nr; i++)
 401                 argv[i] = path_list->items[i].string;
 402         argv[path_list->nr] = NULL;
 403
 404         if (prefix && chdir(prefix))
 405                 die(_("Failed to chdir: %s"), prefix);
 406         status = run_command_v_opt(argv, RUN_USING_SHELL);
 407         if (status)
 408                 exit(status);
 409         free(argv);
 410 }
 411
 412 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 413 {
 414         int hit = 0;
 415         int nr;
 416         read_cache();
 417
 418         for (nr = 0; nr < active_nr; nr++) {
 419                 struct cache_entry *ce = active_cache[nr];
 420                 if (!S_ISREG(ce->ce_mode))
 421                         continue;
 422                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 423                         continue;
 424                 /*
 425                  * If CE_VALID is on, we assume worktree file and its cache entry
 426                  * are identical, even if worktree file has been modified, so use
 427                  * cache version instead
 428                  */
 429                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 430                         if (ce_stage(ce))
 431                                 continue;
 432                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 433                 }
 434                 else
 435                         hit |= grep_file(opt, ce->name);
 436                 if (ce_stage(ce)) {
 437                         do {
 438                                 nr++;
 439                         } while (nr < active_nr &&
 440                                  !strcmp(ce->name, active_cache[nr]->name));
 441                         nr--; /* compensate for loop control */
 442                 }
 443                 if (hit && opt->status_only)
 444                         break;
 445         }
 446         return hit;
 447 }
 448
 449 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 450                      struct tree_desc *tree, struct strbuf *base, int tn_len)
 451 {
 452         int hit = 0;
 453         enum interesting match = entry_not_interesting;
 454         struct name_entry entry;
 455         int old_baselen = base->len;
 456
 457         while (tree_entry(tree, &entry)) {
 458                 int te_len = tree_entry_len(&entry);
 459
 460                 if (match != all_entries_interesting) {
 461                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 462                         if (match == all_entries_not_interesting)
 463                                 break;
 464                         if (match == entry_not_interesting)
 465                                 continue;
 466                 }
 467
 468                 strbuf_add(base, entry.path, te_len);
 469
 470                 if (S_ISREG(entry.mode)) {
 471                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
 472                 }
 473                 else if (S_ISDIR(entry.mode)) {
 474                         enum object_type type;
 475                         struct tree_desc sub;
 476                         void *data;
 477                         unsigned long size;
 478
 479                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 480                         if (!data)
 481                                 die(_("unable to read tree (%s)"),
 482                                     sha1_to_hex(entry.sha1));
 483
 484                         strbuf_addch(base, '/');
 485                         init_tree_desc(&sub, data, size);
 486                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
 487                         free(data);
 488                 }
 489                 strbuf_setlen(base, old_baselen);
 490
 491                 if (hit && opt->status_only)
 492                         break;
 493         }
 494         return hit;
 495 }
 496
 497 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 498                        struct object *obj, const char *name)
 499 {
 500         if (obj->type == OBJ_BLOB)
 501                 return grep_sha1(opt, obj->sha1, name, 0);
 502         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 503                 struct tree_desc tree;
 504                 void *data;
 505                 unsigned long size;
 506                 struct strbuf base;
 507                 int hit, len;
 508
 509                 grep_read_lock();
 510                 data = read_object_with_reference(obj->sha1, tree_type,
 511                                                   &size, NULL);
 512                 grep_read_unlock();
 513
 514                 if (!data)
 515                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 516
 517                 len = name ? strlen(name) : 0;
 518                 strbuf_init(&base, PATH_MAX + len + 1);
 519                 if (len) {
 520                         strbuf_add(&base, name, len);
 521                         strbuf_addch(&base, ':');
 522                 }
 523                 init_tree_desc(&tree, data, size);
 524                 hit = grep_tree(opt, pathspec, &tree, &base, base.len);
 525                 strbuf_release(&base);
 526                 free(data);
 527                 return hit;
 528         }
 529         die(_("unable to grep from object of type %s"), typename(obj->type));
 530 }
 531
 532 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 533                         const struct object_array *list)
 534 {
 535         unsigned int i;
 536         int hit = 0;
 537         const unsigned int nr = list->nr;
 538
 539         for (i = 0; i < nr; i++) {
 540                 struct object *real_obj;
 541                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
 542                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 543                         hit = 1;
 544                         if (opt->status_only)
 545                                 break;
 546                 }
 547         }
 548         return hit;
 549 }
 550
 551 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 552                           int exc_std)
 553 {
 554         struct dir_struct dir;
 555         int i, hit = 0;
 556
 557         memset(&dir, 0, sizeof(dir));
 558         if (exc_std)
 559                 setup_standard_excludes(&dir);
 560
 561         fill_directory(&dir, pathspec->raw);
 562         for (i = 0; i < dir.nr; i++) {
 563                 const char *name = dir.entries[i]->name;
 564                 int namelen = strlen(name);
 565                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 566                         continue;
 567                 hit |= grep_file(opt, dir.entries[i]->name);
 568                 if (hit && opt->status_only)
 569                         break;
 570         }
 571         return hit;
 572 }
 573
 574 static int context_callback(const struct option *opt, const char *arg,
 575                             int unset)
 576 {
 577         struct grep_opt *grep_opt = opt->value;
 578         int value;
 579         const char *endp;
 580
 581         if (unset) {
 582                 grep_opt->pre_context = grep_opt->post_context = 0;
 583                 return 0;
 584         }
 585         value = strtol(arg, (char **)&endp, 10);
 586         if (*endp) {
 587                 return error(_("switch `%c' expects a numerical value"),
 588                              opt->short_name);
 589         }
 590         grep_opt->pre_context = grep_opt->post_context = value;
 591         return 0;
 592 }
 593
 594 static int file_callback(const struct option *opt, const char *arg, int unset)
 595 {
 596         struct grep_opt *grep_opt = opt->value;
 597         int from_stdin = !strcmp(arg, "-");
 598         FILE *patterns;
 599         int lno = 0;
 600         struct strbuf sb = STRBUF_INIT;
 601
 602         patterns = from_stdin ? stdin : fopen(arg, "r");
 603         if (!patterns)
 604                 die_errno(_("cannot open '%s'"), arg);
 605         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 606                 char *s;
 607                 size_t len;
 608
 609                 /* ignore empty line like grep does */
 610                 if (sb.len == 0)
 611                         continue;
 612
 613                 s = strbuf_detach(&sb, &len);
 614                 append_grep_pat(grep_opt, s, len, arg, ++lno, GREP_PATTERN);
 615         }
 616         if (!from_stdin)
 617                 fclose(patterns);
 618         strbuf_release(&sb);
 619         return 0;
 620 }
 621
 622 static int not_callback(const struct option *opt, const char *arg, int unset)
 623 {
 624         struct grep_opt *grep_opt = opt->value;
 625         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 626         return 0;
 627 }
 628
 629 static int and_callback(const struct option *opt, const char *arg, int unset)
 630 {
 631         struct grep_opt *grep_opt = opt->value;
 632         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 633         return 0;
 634 }
 635
 636 static int open_callback(const struct option *opt, const char *arg, int unset)
 637 {
 638         struct grep_opt *grep_opt = opt->value;
 639         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 640         return 0;
 641 }
 642
 643 static int close_callback(const struct option *opt, const char *arg, int unset)
 644 {
 645         struct grep_opt *grep_opt = opt->value;
 646         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 647         return 0;
 648 }
 649
 650 static int pattern_callback(const struct option *opt, const char *arg,
 651                             int unset)
 652 {
 653         struct grep_opt *grep_opt = opt->value;
 654         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 655         return 0;
 656 }
 657
 658 static int help_callback(const struct option *opt, const char *arg, int unset)
 659 {
 660         return -1;
 661 }
 662
 663 int cmd_grep(int argc, const char **argv, const char *prefix)
 664 {
 665         int hit = 0;
 666         int cached = 0, untracked = 0, opt_exclude = -1;
 667         int seen_dashdash = 0;
 668         int external_grep_allowed__ignored;
 669         const char *show_in_pager = NULL, *default_pager = "dummy";
 670         struct grep_opt opt;
 671         struct object_array list = OBJECT_ARRAY_INIT;
 672         const char **paths = NULL;
 673         struct pathspec pathspec;
 674         struct string_list path_list = STRING_LIST_INIT_NODUP;
 675         int i;
 676         int dummy;
 677         int use_index = 1;
 678         enum {
 679                 pattern_type_unspecified = 0,
 680                 pattern_type_bre,
 681                 pattern_type_ere,
 682                 pattern_type_fixed,
 683                 pattern_type_pcre,
 684         };
 685         int pattern_type = pattern_type_unspecified;
 686
 687         struct option options[] = {
 688                 OPT_BOOLEAN(0, "cached", &cached,
 689                         "search in index instead of in the work tree"),
 690                 { OPTION_BOOLEAN, 0, "index", &use_index, NULL,
 691                         "finds in contents not managed by git",
 692                         PARSE_OPT_NOARG | PARSE_OPT_NEGHELP },
 693                 OPT_BOOLEAN(0, "untracked", &untracked,
 694                         "search in both tracked and untracked files"),
 695                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 696                             "search also in ignored files", 1),
 697                 OPT_GROUP(""),
 698                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 699                         "show non-matching lines"),
 700                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 701                         "case insensitive matching"),
 702                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 703                         "match patterns only at word boundaries"),
 704                 OPT_SET_INT('a', "text", &opt.binary,
 705                         "process binary files as text", GREP_BINARY_TEXT),
 706                 OPT_SET_INT('I', NULL, &opt.binary,
 707                         "don't match patterns in binary files",
 708                         GREP_BINARY_NOMATCH),
 709                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
 710                         "descend at most <depth> levels", PARSE_OPT_NONEG,
 711                         NULL, 1 },
 712                 OPT_GROUP(""),
 713                 OPT_SET_INT('E', "extended-regexp", &pattern_type,
 714                             "use extended POSIX regular expressions",
 715                             pattern_type_ere),
 716                 OPT_SET_INT('G', "basic-regexp", &pattern_type,
 717                             "use basic POSIX regular expressions (default)",
 718                             pattern_type_bre),
 719                 OPT_SET_INT('F', "fixed-strings", &pattern_type,
 720                             "interpret patterns as fixed strings",
 721                             pattern_type_fixed),
 722                 OPT_SET_INT('P', "perl-regexp", &pattern_type,
 723                             "use Perl-compatible regular expressions",
 724                             pattern_type_pcre),
 725                 OPT_GROUP(""),
 726                 OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
 727                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 728                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 729                 OPT_NEGBIT(0, "full-name", &opt.relative,
 730                         "show filenames relative to top directory", 1),
 731                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 732                         "show only filenames instead of matching lines"),
 733                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 734                         "synonym for --files-with-matches"),
 735                 OPT_BOOLEAN('L', "files-without-match",
 736                         &opt.unmatch_name_only,
 737                         "show only the names of files without match"),
 738                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 739                         "print NUL after filenames"),
 740                 OPT_BOOLEAN('c', "count", &opt.count,
 741                         "show the number of matches instead of matching lines"),
 742                 OPT__COLOR(&opt.color, "highlight matches"),
 743                 OPT_BOOLEAN(0, "break", &opt.file_break,
 744                         "print empty line between matches from different files"),
 745                 OPT_BOOLEAN(0, "heading", &opt.heading,
 746                         "show filename only once above matches from same file"),
 747                 OPT_GROUP(""),
 748                 OPT_CALLBACK('C', "context", &opt, "n",
 749                         "show <n> context lines before and after matches",
 750                         context_callback),
 751                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 752                         "show <n> context lines before matches"),
 753                 OPT_INTEGER('A', "after-context", &opt.post_context,
 754                         "show <n> context lines after matches"),
 755                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 756                         context_callback),
 757                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 758                         "show a line with the function name before matches"),
 759                 OPT_BOOLEAN('W', "function-context", &opt.funcbody,
 760                         "show the surrounding function"),
 761                 OPT_GROUP(""),
 762                 OPT_CALLBACK('f', NULL, &opt, "file",
 763                         "read patterns from file", file_callback),
 764                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 765                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 766                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 767                   "combine patterns specified with -e",
 768                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 769                 OPT_BOOLEAN(0, "or", &dummy, ""),
 770                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 771                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 772                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 773                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 774                   open_callback },
 775                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 776                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 777                   close_callback },
 778                 OPT__QUIET(&opt.status_only,
 779                            "indicate hit with exit status without output"),
 780                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 781                         "show only matches from files that match all patterns"),
 782                 OPT_GROUP(""),
 783                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 784                         "pager", "show matching files in the pager",
 785                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 786                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
 787                             "allow calling of grep(1) (ignored by this build)"),
 788                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 789                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 790                 OPT_END()
 791         };
 792
 793         /*
 794          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 795          * to show usage information and exit.
 796          */
 797         if (argc == 2 && !strcmp(argv[1], "-h"))
 798                 usage_with_options(grep_usage, options);
 799
 800         memset(&opt, 0, sizeof(opt));
 801         opt.prefix = prefix;
 802         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 803         opt.relative = 1;
 804         opt.pathname = 1;
 805         opt.pattern_tail = &opt.pattern_list;
 806         opt.header_tail = &opt.header_list;
 807         opt.regflags = REG_NEWLINE;
 808         opt.max_depth = -1;
 809
 810         strcpy(opt.color_context, "");
 811         strcpy(opt.color_filename, "");
 812         strcpy(opt.color_function, "");
 813         strcpy(opt.color_lineno, "");
 814         strcpy(opt.color_match, GIT_COLOR_BOLD_RED);
 815         strcpy(opt.color_selected, "");
 816         strcpy(opt.color_sep, GIT_COLOR_CYAN);
 817         opt.color = -1;
 818         git_config(grep_config, &opt);
 819
 820         /*
 821          * If there is no -- then the paths must exist in the working
 822          * tree.  If there is no explicit pattern specified with -e or
 823          * -f, we take the first unrecognized non option to be the
 824          * pattern, but then what follows it must be zero or more
 825          * valid refs up to the -- (if exists), and then existing
 826          * paths.  If there is an explicit pattern, then the first
 827          * unrecognized non option is the beginning of the refs list
 828          * that continues up to the -- (if exists), and then paths.
 829          */
 830         argc = parse_options(argc, argv, prefix, options, grep_usage,
 831                              PARSE_OPT_KEEP_DASHDASH |
 832                              PARSE_OPT_STOP_AT_NON_OPTION |
 833                              PARSE_OPT_NO_INTERNAL_HELP);
 834         switch (pattern_type) {
 835         case pattern_type_fixed:
 836                 opt.fixed = 1;
 837                 opt.pcre = 0;
 838                 break;
 839         case pattern_type_bre:
 840                 opt.fixed = 0;
 841                 opt.pcre = 0;
 842                 opt.regflags &= ~REG_EXTENDED;
 843                 break;
 844         case pattern_type_ere:
 845                 opt.fixed = 0;
 846                 opt.pcre = 0;
 847                 opt.regflags |= REG_EXTENDED;
 848                 break;
 849         case pattern_type_pcre:
 850                 opt.fixed = 0;
 851                 opt.pcre = 1;
 852                 break;
 853         default:
 854                 break; /* nothing */
 855         }
 856
 857         if (use_index && !startup_info->have_repository)
 858                 /* die the same way as if we did it at the beginning */
 859                 setup_git_directory();
 860
 861         /*
 862          * skip a -- separator; we know it cannot be
 863          * separating revisions from pathnames if
 864          * we haven't even had any patterns yet
 865          */
 866         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 867                 argv++;
 868                 argc--;
 869         }
 870
 871         /* First unrecognized non-option token */
 872         if (argc > 0 && !opt.pattern_list) {
 873                 append_grep_pattern(&opt, argv[0], "command line", 0,
 874                                     GREP_PATTERN);
 875                 argv++;
 876                 argc--;
 877         }
 878
 879         if (show_in_pager == default_pager)
 880                 show_in_pager = git_pager(1);
 881         if (show_in_pager) {
 882                 opt.color = 0;
 883                 opt.name_only = 1;
 884                 opt.null_following_name = 1;
 885                 opt.output_priv = &path_list;
 886                 opt.output = append_path;
 887                 string_list_append(&path_list, show_in_pager);
 888                 use_threads = 0;
 889         }
 890
 891         if (!opt.pattern_list)
 892                 die(_("no pattern given."));
 893         if (!opt.fixed && opt.ignore_case)
 894                 opt.regflags |= REG_ICASE;
 895
 896         compile_grep_patterns(&opt);
 897
 898         /* Check revs and then paths */
 899         for (i = 0; i < argc; i++) {
 900                 const char *arg = argv[i];
 901                 unsigned char sha1[20];
 902                 /* Is it a rev? */
 903                 if (!get_sha1(arg, sha1)) {
 904                         struct object *object = parse_object(sha1);
 905                         if (!object)
 906                                 die(_("bad object %s"), arg);
 907                         add_object_array(object, arg, &list);
 908                         continue;
 909                 }
 910                 if (!strcmp(arg, "--")) {
 911                         i++;
 912                         seen_dashdash = 1;
 913                 }
 914                 break;
 915         }
 916
 917 #ifndef NO_PTHREADS
 918         if (list.nr || cached || online_cpus() == 1)
 919                 use_threads = 0;
 920 #else
 921         use_threads = 0;
 922 #endif
 923
 924 #ifndef NO_PTHREADS
 925         if (use_threads) {
 926                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 927                     && (opt.pre_context || opt.post_context ||
 928                         opt.file_break || opt.funcbody))
 929                         skip_first_line = 1;
 930                 start_threads(&opt);
 931         }
 932 #endif
 933
 934         /* The rest are paths */
 935         if (!seen_dashdash) {
 936                 int j;
 937                 for (j = i; j < argc; j++)
 938                         verify_filename(prefix, argv[j]);
 939         }
 940
 941         paths = get_pathspec(prefix, argv + i);
 942         init_pathspec(&pathspec, paths);
 943         pathspec.max_depth = opt.max_depth;
 944         pathspec.recursive = 1;
 945
 946         if (show_in_pager && (cached || list.nr))
 947                 die(_("--open-files-in-pager only works on the worktree"));
 948
 949         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 950                 const char *pager = path_list.items[0].string;
 951                 int len = strlen(pager);
 952
 953                 if (len > 4 && is_dir_sep(pager[len - 5]))
 954                         pager += len - 4;
 955
 956                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 957                         struct strbuf buf = STRBUF_INIT;
 958                         strbuf_addf(&buf, "+/%s%s",
 959                                         strcmp("less", pager) ? "" : "*",
 960                                         opt.pattern_list->pattern);
 961                         string_list_append(&path_list, buf.buf);
 962                         strbuf_detach(&buf, NULL);
 963                 }
 964         }
 965
 966         if (!show_in_pager)
 967                 setup_pager();
 968
 969         if (!use_index && (untracked || cached))
 970                 die(_("--cached or --untracked cannot be used with --no-index."));
 971
 972         if (!use_index || untracked) {
 973                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 974                 if (list.nr)
 975                         die(_("--no-index or --untracked cannot be used with revs."));
 976                 hit = grep_directory(&opt, &pathspec, use_exclude);
 977         } else if (0 <= opt_exclude) {
 978                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 979         } else if (!list.nr) {
 980                 if (!cached)
 981                         setup_work_tree();
 982
 983                 hit = grep_cache(&opt, &pathspec, cached);
 984         } else {
 985                 if (cached)
 986                         die(_("both --cached and trees are given."));
 987                 hit = grep_objects(&opt, &pathspec, &list);
 988         }
 989
 990         if (use_threads)
 991                 hit |= wait_all();
 992         if (hit && show_in_pager)
 993                 run_pager(&opt, prefix);
 994         free_grep_patterns(&opt);
 995         return !hit;
 996 }