builtin/grep.c

   1 /*
   2  * Builtin "git grep"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   7 #include "cache.h"
   8 #include "repository.h"
   9 #include "config.h"
  10 #include "blob.h"
  11 #include "tree.h"
  12 #include "commit.h"
  13 #include "tag.h"
  14 #include "tree-walk.h"
  15 #include "builtin.h"
  16 #include "parse-options.h"
  17 #include "string-list.h"
  18 #include "run-command.h"
  19 #include "userdiff.h"
  20 #include "grep.h"
  21 #include "quote.h"
  22 #include "dir.h"
  23 #include "pathspec.h"
  24 #include "submodule.h"
  25 #include "submodule-config.h"
  26 #include "object-store.h"
  27
  28 static char const * const grep_usage[] = {
  29         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
  30         NULL
  31 };
  32
  33 static int recurse_submodules;
  34
  35 #define GREP_NUM_THREADS_DEFAULT 8
  36 static int num_threads;
  37
  38 static pthread_t *threads;
  39
  40 /* We use one producer thread and THREADS consumer
  41  * threads. The producer adds struct work_items to 'todo' and the
  42  * consumers pick work items from the same array.
  43  */
  44 struct work_item {
  45         struct grep_source source;
  46         char done;
  47         struct strbuf out;
  48 };
  49
  50 /* In the range [todo_done, todo_start) in 'todo' we have work_items
  51  * that have been or are processed by a consumer thread. We haven't
  52  * written the result for these to stdout yet.
  53  *
  54  * The work_items in [todo_start, todo_end) are waiting to be picked
  55  * up by a consumer thread.
  56  *
  57  * The ranges are modulo TODO_SIZE.
  58  */
  59 #define TODO_SIZE 128
  60 static struct work_item todo[TODO_SIZE];
  61 static int todo_start;
  62 static int todo_end;
  63 static int todo_done;
  64
  65 /* Has all work items been added? */
  66 static int all_work_added;
  67
  68 /* This lock protects all the variables above. */
  69 static pthread_mutex_t grep_mutex;
  70
  71 static inline void grep_lock(void)
  72 {
  73         pthread_mutex_lock(&grep_mutex);
  74 }
  75
  76 static inline void grep_unlock(void)
  77 {
  78         pthread_mutex_unlock(&grep_mutex);
  79 }
  80
  81 /* Signalled when a new work_item is added to todo. */
  82 static pthread_cond_t cond_add;
  83
  84 /* Signalled when the result from one work_item is written to
  85  * stdout.
  86  */
  87 static pthread_cond_t cond_write;
  88
  89 /* Signalled when we are finished with everything. */
  90 static pthread_cond_t cond_result;
  91
  92 static int skip_first_line;
  93
  94 static void add_work(struct grep_opt *opt, const struct grep_source *gs)
  95 {
  96         grep_lock();
  97
  98         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
  99                 pthread_cond_wait(&cond_write, &grep_mutex);
 100         }
 101
 102         todo[todo_end].source = *gs;
 103         if (opt->binary != GREP_BINARY_TEXT)
 104                 grep_source_load_driver(&todo[todo_end].source,
 105                                         opt->repo->index);
 106         todo[todo_end].done = 0;
 107         strbuf_reset(&todo[todo_end].out);
 108         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 109
 110         pthread_cond_signal(&cond_add);
 111         grep_unlock();
 112 }
 113
 114 static struct work_item *get_work(void)
 115 {
 116         struct work_item *ret;
 117
 118         grep_lock();
 119         while (todo_start == todo_end && !all_work_added) {
 120                 pthread_cond_wait(&cond_add, &grep_mutex);
 121         }
 122
 123         if (todo_start == todo_end && all_work_added) {
 124                 ret = NULL;
 125         } else {
 126                 ret = &todo[todo_start];
 127                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 128         }
 129         grep_unlock();
 130         return ret;
 131 }
 132
 133 static void work_done(struct work_item *w)
 134 {
 135         int old_done;
 136
 137         grep_lock();
 138         w->done = 1;
 139         old_done = todo_done;
 140         for(; todo[todo_done].done && todo_done != todo_start;
 141             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 142                 w = &todo[todo_done];
 143                 if (w->out.len) {
 144                         const char *p = w->out.buf;
 145                         size_t len = w->out.len;
 146
 147                         /* Skip the leading hunk mark of the first file. */
 148                         if (skip_first_line) {
 149                                 while (len) {
 150                                         len--;
 151                                         if (*p++ == '\n')
 152                                                 break;
 153                                 }
 154                                 skip_first_line = 0;
 155                         }
 156
 157                         write_or_die(1, p, len);
 158                 }
 159                 grep_source_clear(&w->source);
 160         }
 161
 162         if (old_done != todo_done)
 163                 pthread_cond_signal(&cond_write);
 164
 165         if (all_work_added && todo_done == todo_end)
 166                 pthread_cond_signal(&cond_result);
 167
 168         grep_unlock();
 169 }
 170
 171 static void *run(void *arg)
 172 {
 173         int hit = 0;
 174         struct grep_opt *opt = arg;
 175
 176         while (1) {
 177                 struct work_item *w = get_work();
 178                 if (!w)
 179                         break;
 180
 181                 opt->output_priv = w;
 182                 hit |= grep_source(opt, &w->source);
 183                 grep_source_clear_data(&w->source);
 184                 work_done(w);
 185         }
 186         free_grep_patterns(arg);
 187         free(arg);
 188
 189         return (void*) (intptr_t) hit;
 190 }
 191
 192 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 193 {
 194         struct work_item *w = opt->output_priv;
 195         strbuf_add(&w->out, buf, size);
 196 }
 197
 198 static void start_threads(struct grep_opt *opt)
 199 {
 200         int i;
 201
 202         pthread_mutex_init(&grep_mutex, NULL);
 203         pthread_mutex_init(&grep_read_mutex, NULL);
 204         pthread_mutex_init(&grep_attr_mutex, NULL);
 205         pthread_cond_init(&cond_add, NULL);
 206         pthread_cond_init(&cond_write, NULL);
 207         pthread_cond_init(&cond_result, NULL);
 208         grep_use_locks = 1;
 209
 210         for (i = 0; i < ARRAY_SIZE(todo); i++) {
 211                 strbuf_init(&todo[i].out, 0);
 212         }
 213
 214         threads = xcalloc(num_threads, sizeof(*threads));
 215         for (i = 0; i < num_threads; i++) {
 216                 int err;
 217                 struct grep_opt *o = grep_opt_dup(opt);
 218                 o->output = strbuf_out;
 219                 if (i)
 220                         o->debug = 0;
 221                 compile_grep_patterns(o);
 222                 err = pthread_create(&threads[i], NULL, run, o);
 223
 224                 if (err)
 225                         die(_("grep: failed to create thread: %s"),
 226                             strerror(err));
 227         }
 228 }
 229
 230 static int wait_all(void)
 231 {
 232         int hit = 0;
 233         int i;
 234
 235         if (!HAVE_THREADS)
 236                 BUG("Never call this function unless you have started threads");
 237
 238         grep_lock();
 239         all_work_added = 1;
 240
 241         /* Wait until all work is done. */
 242         while (todo_done != todo_end)
 243                 pthread_cond_wait(&cond_result, &grep_mutex);
 244
 245         /* Wake up all the consumer threads so they can see that there
 246          * is no more work to do.
 247          */
 248         pthread_cond_broadcast(&cond_add);
 249         grep_unlock();
 250
 251         for (i = 0; i < num_threads; i++) {
 252                 void *h;
 253                 pthread_join(threads[i], &h);
 254                 hit |= (int) (intptr_t) h;
 255         }
 256
 257         free(threads);
 258
 259         pthread_mutex_destroy(&grep_mutex);
 260         pthread_mutex_destroy(&grep_read_mutex);
 261         pthread_mutex_destroy(&grep_attr_mutex);
 262         pthread_cond_destroy(&cond_add);
 263         pthread_cond_destroy(&cond_write);
 264         pthread_cond_destroy(&cond_result);
 265         grep_use_locks = 0;
 266
 267         return hit;
 268 }
 269
 270 static int grep_cmd_config(const char *var, const char *value, void *cb)
 271 {
 272         int st = grep_config(var, value, cb);
 273         if (git_color_default_config(var, value, cb) < 0)
 274                 st = -1;
 275
 276         if (!strcmp(var, "grep.threads")) {
 277                 num_threads = git_config_int(var, value);
 278                 if (num_threads < 0)
 279                         die(_("invalid number of threads specified (%d) for %s"),
 280                             num_threads, var);
 281                 else if (!HAVE_THREADS && num_threads > 1) {
 282                         /*
 283                          * TRANSLATORS: %s is the configuration
 284                          * variable for tweaking threads, currently
 285                          * grep.threads
 286                          */
 287                         warning(_("no threads support, ignoring %s"), var);
 288                         num_threads = 1;
 289                 }
 290         }
 291
 292         if (!strcmp(var, "submodule.recurse"))
 293                 recurse_submodules = git_config_bool(var, value);
 294
 295         return st;
 296 }
 297
 298 static void *lock_and_read_oid_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
 299 {
 300         void *data;
 301
 302         grep_read_lock();
 303         data = read_object_file(oid, type, size);
 304         grep_read_unlock();
 305         return data;
 306 }
 307
 308 static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 309                      const char *filename, int tree_name_len,
 310                      const char *path)
 311 {
 312         struct strbuf pathbuf = STRBUF_INIT;
 313         struct grep_source gs;
 314
 315         if (opt->relative && opt->prefix_length) {
 316                 quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
 317                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 318         } else {
 319                 strbuf_addstr(&pathbuf, filename);
 320         }
 321
 322         grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
 323         strbuf_release(&pathbuf);
 324
 325         if (num_threads > 1) {
 326                 /*
 327                  * add_work() copies gs and thus assumes ownership of
 328                  * its fields, so do not call grep_source_clear()
 329                  */
 330                 add_work(opt, &gs);
 331                 return 0;
 332         } else {
 333                 int hit;
 334
 335                 hit = grep_source(opt, &gs);
 336
 337                 grep_source_clear(&gs);
 338                 return hit;
 339         }
 340 }
 341
 342 static int grep_file(struct grep_opt *opt, const char *filename)
 343 {
 344         struct strbuf buf = STRBUF_INIT;
 345         struct grep_source gs;
 346
 347         if (opt->relative && opt->prefix_length)
 348                 quote_path_relative(filename, opt->prefix, &buf);
 349         else
 350                 strbuf_addstr(&buf, filename);
 351
 352         grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
 353         strbuf_release(&buf);
 354
 355         if (num_threads > 1) {
 356                 /*
 357                  * add_work() copies gs and thus assumes ownership of
 358                  * its fields, so do not call grep_source_clear()
 359                  */
 360                 add_work(opt, &gs);
 361                 return 0;
 362         } else {
 363                 int hit;
 364
 365                 hit = grep_source(opt, &gs);
 366
 367                 grep_source_clear(&gs);
 368                 return hit;
 369         }
 370 }
 371
 372 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 373 {
 374         struct string_list *path_list = opt->output_priv;
 375
 376         if (len == 1 && *(const char *)data == '\0')
 377                 return;
 378         string_list_append(path_list, xstrndup(data, len));
 379 }
 380
 381 static void run_pager(struct grep_opt *opt, const char *prefix)
 382 {
 383         struct string_list *path_list = opt->output_priv;
 384         struct child_process child = CHILD_PROCESS_INIT;
 385         int i, status;
 386
 387         for (i = 0; i < path_list->nr; i++)
 388                 argv_array_push(&child.args, path_list->items[i].string);
 389         child.dir = prefix;
 390         child.use_shell = 1;
 391
 392         status = run_command(&child);
 393         if (status)
 394                 exit(status);
 395 }
 396
 397 static int grep_cache(struct grep_opt *opt,
 398                       const struct pathspec *pathspec, int cached);
 399 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 400                      struct tree_desc *tree, struct strbuf *base, int tn_len,
 401                      int check_attr);
 402
 403 static int grep_submodule(struct grep_opt *opt,
 404                           const struct pathspec *pathspec,
 405                           const struct object_id *oid,
 406                           const char *filename, const char *path)
 407 {
 408         struct repository subrepo;
 409         struct repository *superproject = opt->repo;
 410         const struct submodule *sub = submodule_from_path(superproject,
 411                                                           &null_oid, path);
 412         struct grep_opt subopt;
 413         int hit;
 414
 415         /*
 416          * NEEDSWORK: submodules functions need to be protected because they
 417          * access the object store via config_from_gitmodules(): the latter
 418          * uses get_oid() which, for now, relies on the global the_repository
 419          * object.
 420          */
 421         grep_read_lock();
 422
 423         if (!is_submodule_active(superproject, path)) {
 424                 grep_read_unlock();
 425                 return 0;
 426         }
 427
 428         if (repo_submodule_init(&subrepo, superproject, sub)) {
 429                 grep_read_unlock();
 430                 return 0;
 431         }
 432
 433         repo_read_gitmodules(&subrepo);
 434
 435         /*
 436          * NEEDSWORK: This adds the submodule's object directory to the list of
 437          * alternates for the single in-memory object store.  This has some bad
 438          * consequences for memory (processed objects will never be freed) and
 439          * performance (this increases the number of pack files git has to pay
 440          * attention to, to the sum of the number of pack files in all the
 441          * repositories processed so far).  This can be removed once the object
 442          * store is no longer global and instead is a member of the repository
 443          * object.
 444          */
 445         add_to_alternates_memory(subrepo.objects->odb->path);
 446         grep_read_unlock();
 447
 448         memcpy(&subopt, opt, sizeof(subopt));
 449         subopt.repo = &subrepo;
 450
 451         if (oid) {
 452                 struct object *object;
 453                 struct tree_desc tree;
 454                 void *data;
 455                 unsigned long size;
 456                 struct strbuf base = STRBUF_INIT;
 457
 458                 object = parse_object_or_die(oid, oid_to_hex(oid));
 459
 460                 grep_read_lock();
 461                 data = read_object_with_reference(&subrepo,
 462                                                   &object->oid, tree_type,
 463                                                   &size, NULL);
 464                 grep_read_unlock();
 465
 466                 if (!data)
 467                         die(_("unable to read tree (%s)"), oid_to_hex(&object->oid));
 468
 469                 strbuf_addstr(&base, filename);
 470                 strbuf_addch(&base, '/');
 471
 472                 init_tree_desc(&tree, data, size);
 473                 hit = grep_tree(&subopt, pathspec, &tree, &base, base.len,
 474                                 object->type == OBJ_COMMIT);
 475                 strbuf_release(&base);
 476                 free(data);
 477         } else {
 478                 hit = grep_cache(&subopt, pathspec, 1);
 479         }
 480
 481         repo_clear(&subrepo);
 482         return hit;
 483 }
 484
 485 static int grep_cache(struct grep_opt *opt,
 486                       const struct pathspec *pathspec, int cached)
 487 {
 488         struct repository *repo = opt->repo;
 489         int hit = 0;
 490         int nr;
 491         struct strbuf name = STRBUF_INIT;
 492         int name_base_len = 0;
 493         if (repo->submodule_prefix) {
 494                 name_base_len = strlen(repo->submodule_prefix);
 495                 strbuf_addstr(&name, repo->submodule_prefix);
 496         }
 497
 498         if (repo_read_index(repo) < 0)
 499                 die(_("index file corrupt"));
 500
 501         for (nr = 0; nr < repo->index->cache_nr; nr++) {
 502                 const struct cache_entry *ce = repo->index->cache[nr];
 503                 strbuf_setlen(&name, name_base_len);
 504                 strbuf_addstr(&name, ce->name);
 505
 506                 if (S_ISREG(ce->ce_mode) &&
 507                     match_pathspec(repo->index, pathspec, name.buf, name.len, 0, NULL,
 508                                    S_ISDIR(ce->ce_mode) ||
 509                                    S_ISGITLINK(ce->ce_mode))) {
 510                         /*
 511                          * If CE_VALID is on, we assume worktree file and its
 512                          * cache entry are identical, even if worktree file has
 513                          * been modified, so use cache version instead
 514                          */
 515                         if (cached || (ce->ce_flags & CE_VALID) ||
 516                             ce_skip_worktree(ce)) {
 517                                 if (ce_stage(ce) || ce_intent_to_add(ce))
 518                                         continue;
 519                                 hit |= grep_oid(opt, &ce->oid, name.buf,
 520                                                  0, name.buf);
 521                         } else {
 522                                 hit |= grep_file(opt, name.buf);
 523                         }
 524                 } else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
 525                            submodule_path_match(repo->index, pathspec, name.buf, NULL)) {
 526                         hit |= grep_submodule(opt, pathspec, NULL, ce->name, ce->name);
 527                 } else {
 528                         continue;
 529                 }
 530
 531                 if (ce_stage(ce)) {
 532                         do {
 533                                 nr++;
 534                         } while (nr < repo->index->cache_nr &&
 535                                  !strcmp(ce->name, repo->index->cache[nr]->name));
 536                         nr--; /* compensate for loop control */
 537                 }
 538                 if (hit && opt->status_only)
 539                         break;
 540         }
 541
 542         strbuf_release(&name);
 543         return hit;
 544 }
 545
 546 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 547                      struct tree_desc *tree, struct strbuf *base, int tn_len,
 548                      int check_attr)
 549 {
 550         struct repository *repo = opt->repo;
 551         int hit = 0;
 552         enum interesting match = entry_not_interesting;
 553         struct name_entry entry;
 554         int old_baselen = base->len;
 555         struct strbuf name = STRBUF_INIT;
 556         int name_base_len = 0;
 557         if (repo->submodule_prefix) {
 558                 strbuf_addstr(&name, repo->submodule_prefix);
 559                 name_base_len = name.len;
 560         }
 561
 562         while (tree_entry(tree, &entry)) {
 563                 int te_len = tree_entry_len(&entry);
 564
 565                 if (match != all_entries_interesting) {
 566                         strbuf_addstr(&name, base->buf + tn_len);
 567                         match = tree_entry_interesting(repo->index,
 568                                                        &entry, &name,
 569                                                        0, pathspec);
 570                         strbuf_setlen(&name, name_base_len);
 571
 572                         if (match == all_entries_not_interesting)
 573                                 break;
 574                         if (match == entry_not_interesting)
 575                                 continue;
 576                 }
 577
 578                 strbuf_add(base, entry.path, te_len);
 579
 580                 if (S_ISREG(entry.mode)) {
 581                         hit |= grep_oid(opt, &entry.oid, base->buf, tn_len,
 582                                          check_attr ? base->buf + tn_len : NULL);
 583                 } else if (S_ISDIR(entry.mode)) {
 584                         enum object_type type;
 585                         struct tree_desc sub;
 586                         void *data;
 587                         unsigned long size;
 588
 589                         data = lock_and_read_oid_file(&entry.oid, &type, &size);
 590                         if (!data)
 591                                 die(_("unable to read tree (%s)"),
 592                                     oid_to_hex(&entry.oid));
 593
 594                         strbuf_addch(base, '/');
 595                         init_tree_desc(&sub, data, size);
 596                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
 597                                          check_attr);
 598                         free(data);
 599                 } else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
 600                         hit |= grep_submodule(opt, pathspec, &entry.oid,
 601                                               base->buf, base->buf + tn_len);
 602                 }
 603
 604                 strbuf_setlen(base, old_baselen);
 605
 606                 if (hit && opt->status_only)
 607                         break;
 608         }
 609
 610         strbuf_release(&name);
 611         return hit;
 612 }
 613
 614 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 615                        struct object *obj, const char *name, const char *path)
 616 {
 617         if (obj->type == OBJ_BLOB)
 618                 return grep_oid(opt, &obj->oid, name, 0, path);
 619         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 620                 struct tree_desc tree;
 621                 void *data;
 622                 unsigned long size;
 623                 struct strbuf base;
 624                 int hit, len;
 625
 626                 grep_read_lock();
 627                 data = read_object_with_reference(opt->repo,
 628                                                   &obj->oid, tree_type,
 629                                                   &size, NULL);
 630                 grep_read_unlock();
 631
 632                 if (!data)
 633                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
 634
 635                 len = name ? strlen(name) : 0;
 636                 strbuf_init(&base, PATH_MAX + len + 1);
 637                 if (len) {
 638                         strbuf_add(&base, name, len);
 639                         strbuf_addch(&base, ':');
 640                 }
 641                 init_tree_desc(&tree, data, size);
 642                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
 643                                 obj->type == OBJ_COMMIT);
 644                 strbuf_release(&base);
 645                 free(data);
 646                 return hit;
 647         }
 648         die(_("unable to grep from object of type %s"), type_name(obj->type));
 649 }
 650
 651 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 652                         const struct object_array *list)
 653 {
 654         unsigned int i;
 655         int hit = 0;
 656         const unsigned int nr = list->nr;
 657
 658         for (i = 0; i < nr; i++) {
 659                 struct object *real_obj;
 660                 real_obj = deref_tag(opt->repo, list->objects[i].item,
 661                                      NULL, 0);
 662
 663                 /* load the gitmodules file for this rev */
 664                 if (recurse_submodules) {
 665                         submodule_free(opt->repo);
 666                         gitmodules_config_oid(&real_obj->oid);
 667                 }
 668                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
 669                                 list->objects[i].path)) {
 670                         hit = 1;
 671                         if (opt->status_only)
 672                                 break;
 673                 }
 674         }
 675         return hit;
 676 }
 677
 678 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 679                           int exc_std, int use_index)
 680 {
 681         struct dir_struct dir;
 682         int i, hit = 0;
 683
 684         memset(&dir, 0, sizeof(dir));
 685         if (!use_index)
 686                 dir.flags |= DIR_NO_GITLINKS;
 687         if (exc_std)
 688                 setup_standard_excludes(&dir);
 689
 690         fill_directory(&dir, opt->repo->index, pathspec);
 691         for (i = 0; i < dir.nr; i++) {
 692                 if (!dir_path_match(opt->repo->index, dir.entries[i], pathspec, 0, NULL))
 693                         continue;
 694                 hit |= grep_file(opt, dir.entries[i]->name);
 695                 if (hit && opt->status_only)
 696                         break;
 697         }
 698         return hit;
 699 }
 700
 701 static int context_callback(const struct option *opt, const char *arg,
 702                             int unset)
 703 {
 704         struct grep_opt *grep_opt = opt->value;
 705         int value;
 706         const char *endp;
 707
 708         if (unset) {
 709                 grep_opt->pre_context = grep_opt->post_context = 0;
 710                 return 0;
 711         }
 712         value = strtol(arg, (char **)&endp, 10);
 713         if (*endp) {
 714                 return error(_("switch `%c' expects a numerical value"),
 715                              opt->short_name);
 716         }
 717         grep_opt->pre_context = grep_opt->post_context = value;
 718         return 0;
 719 }
 720
 721 static int file_callback(const struct option *opt, const char *arg, int unset)
 722 {
 723         struct grep_opt *grep_opt = opt->value;
 724         int from_stdin;
 725         FILE *patterns;
 726         int lno = 0;
 727         struct strbuf sb = STRBUF_INIT;
 728
 729         BUG_ON_OPT_NEG(unset);
 730
 731         from_stdin = !strcmp(arg, "-");
 732         patterns = from_stdin ? stdin : fopen(arg, "r");
 733         if (!patterns)
 734                 die_errno(_("cannot open '%s'"), arg);
 735         while (strbuf_getline(&sb, patterns) == 0) {
 736                 /* ignore empty line like grep does */
 737                 if (sb.len == 0)
 738                         continue;
 739
 740                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 741                                 GREP_PATTERN);
 742         }
 743         if (!from_stdin)
 744                 fclose(patterns);
 745         strbuf_release(&sb);
 746         return 0;
 747 }
 748
 749 static int not_callback(const struct option *opt, const char *arg, int unset)
 750 {
 751         struct grep_opt *grep_opt = opt->value;
 752         BUG_ON_OPT_NEG(unset);
 753         BUG_ON_OPT_ARG(arg);
 754         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 755         return 0;
 756 }
 757
 758 static int and_callback(const struct option *opt, const char *arg, int unset)
 759 {
 760         struct grep_opt *grep_opt = opt->value;
 761         BUG_ON_OPT_NEG(unset);
 762         BUG_ON_OPT_ARG(arg);
 763         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 764         return 0;
 765 }
 766
 767 static int open_callback(const struct option *opt, const char *arg, int unset)
 768 {
 769         struct grep_opt *grep_opt = opt->value;
 770         BUG_ON_OPT_NEG(unset);
 771         BUG_ON_OPT_ARG(arg);
 772         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 773         return 0;
 774 }
 775
 776 static int close_callback(const struct option *opt, const char *arg, int unset)
 777 {
 778         struct grep_opt *grep_opt = opt->value;
 779         BUG_ON_OPT_NEG(unset);
 780         BUG_ON_OPT_ARG(arg);
 781         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 782         return 0;
 783 }
 784
 785 static int pattern_callback(const struct option *opt, const char *arg,
 786                             int unset)
 787 {
 788         struct grep_opt *grep_opt = opt->value;
 789         BUG_ON_OPT_NEG(unset);
 790         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 791         return 0;
 792 }
 793
 794 int cmd_grep(int argc, const char **argv, const char *prefix)
 795 {
 796         int hit = 0;
 797         int cached = 0, untracked = 0, opt_exclude = -1;
 798         int seen_dashdash = 0;
 799         int external_grep_allowed__ignored;
 800         const char *show_in_pager = NULL, *default_pager = "dummy";
 801         struct grep_opt opt;
 802         struct object_array list = OBJECT_ARRAY_INIT;
 803         struct pathspec pathspec;
 804         struct string_list path_list = STRING_LIST_INIT_NODUP;
 805         int i;
 806         int dummy;
 807         int use_index = 1;
 808         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 809         int allow_revs;
 810
 811         struct option options[] = {
 812                 OPT_BOOL(0, "cached", &cached,
 813                         N_("search in index instead of in the work tree")),
 814                 OPT_NEGBIT(0, "no-index", &use_index,
 815                          N_("find in contents not managed by git"), 1),
 816                 OPT_BOOL(0, "untracked", &untracked,
 817                         N_("search in both tracked and untracked files")),
 818                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 819                             N_("ignore files specified via '.gitignore'"), 1),
 820                 OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
 821                          N_("recursively search in each submodule")),
 822                 OPT_GROUP(""),
 823                 OPT_BOOL('v', "invert-match", &opt.invert,
 824                         N_("show non-matching lines")),
 825                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
 826                         N_("case insensitive matching")),
 827                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
 828                         N_("match patterns only at word boundaries")),
 829                 OPT_SET_INT('a', "text", &opt.binary,
 830                         N_("process binary files as text"), GREP_BINARY_TEXT),
 831                 OPT_SET_INT('I', NULL, &opt.binary,
 832                         N_("don't match patterns in binary files"),
 833                         GREP_BINARY_NOMATCH),
 834                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
 835                          N_("process binary files with textconv filters")),
 836                 OPT_SET_INT('r', "recursive", &opt.max_depth,
 837                             N_("search in subdirectories (default)"), -1),
 838                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 839                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 840                         NULL, 1 },
 841                 OPT_GROUP(""),
 842                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 843                             N_("use extended POSIX regular expressions"),
 844                             GREP_PATTERN_TYPE_ERE),
 845                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 846                             N_("use basic POSIX regular expressions (default)"),
 847                             GREP_PATTERN_TYPE_BRE),
 848                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 849                             N_("interpret patterns as fixed strings"),
 850                             GREP_PATTERN_TYPE_FIXED),
 851                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 852                             N_("use Perl-compatible regular expressions"),
 853                             GREP_PATTERN_TYPE_PCRE),
 854                 OPT_GROUP(""),
 855                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
 856                 OPT_BOOL(0, "column", &opt.columnnum, N_("show column number of first match")),
 857                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 858                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 859                 OPT_NEGBIT(0, "full-name", &opt.relative,
 860                         N_("show filenames relative to top directory"), 1),
 861                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
 862                         N_("show only filenames instead of matching lines")),
 863                 OPT_BOOL(0, "name-only", &opt.name_only,
 864                         N_("synonym for --files-with-matches")),
 865                 OPT_BOOL('L', "files-without-match",
 866                         &opt.unmatch_name_only,
 867                         N_("show only the names of files without match")),
 868                 OPT_BOOL_F('z', "null", &opt.null_following_name,
 869                            N_("print NUL after filenames"),
 870                            PARSE_OPT_NOCOMPLETE),
 871                 OPT_BOOL('o', "only-matching", &opt.only_matching,
 872                         N_("show only matching parts of a line")),
 873                 OPT_BOOL('c', "count", &opt.count,
 874                         N_("show the number of matches instead of matching lines")),
 875                 OPT__COLOR(&opt.color, N_("highlight matches")),
 876                 OPT_BOOL(0, "break", &opt.file_break,
 877                         N_("print empty line between matches from different files")),
 878                 OPT_BOOL(0, "heading", &opt.heading,
 879                         N_("show filename only once above matches from same file")),
 880                 OPT_GROUP(""),
 881                 OPT_CALLBACK('C', "context", &opt, N_("n"),
 882                         N_("show <n> context lines before and after matches"),
 883                         context_callback),
 884                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 885                         N_("show <n> context lines before matches")),
 886                 OPT_INTEGER('A', "after-context", &opt.post_context,
 887                         N_("show <n> context lines after matches")),
 888                 OPT_INTEGER(0, "threads", &num_threads,
 889                         N_("use <n> worker threads")),
 890                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 891                         context_callback),
 892                 OPT_BOOL('p', "show-function", &opt.funcname,
 893                         N_("show a line with the function name before matches")),
 894                 OPT_BOOL('W', "function-context", &opt.funcbody,
 895                         N_("show the surrounding function")),
 896                 OPT_GROUP(""),
 897                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
 898                         N_("read patterns from file"), file_callback),
 899                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 900                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 901                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 902                   N_("combine patterns specified with -e"),
 903                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 904                 OPT_BOOL(0, "or", &dummy, ""),
 905                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 906                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 907                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 908                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 909                   open_callback },
 910                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 911                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 912                   close_callback },
 913                 OPT__QUIET(&opt.status_only,
 914                            N_("indicate hit with exit status without output")),
 915                 OPT_BOOL(0, "all-match", &opt.all_match,
 916                         N_("show only matches from files that match all patterns")),
 917                 OPT_SET_INT_F(0, "debug", &opt.debug,
 918                               N_("show parse tree for grep expression"),
 919                               1, PARSE_OPT_HIDDEN),
 920                 OPT_GROUP(""),
 921                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 922                         N_("pager"), N_("show matching files in the pager"),
 923                         PARSE_OPT_OPTARG | PARSE_OPT_NOCOMPLETE,
 924                         NULL, (intptr_t)default_pager },
 925                 OPT_BOOL_F(0, "ext-grep", &external_grep_allowed__ignored,
 926                            N_("allow calling of grep(1) (ignored by this build)"),
 927                            PARSE_OPT_NOCOMPLETE),
 928                 OPT_END()
 929         };
 930
 931         init_grep_defaults(the_repository);
 932         git_config(grep_cmd_config, NULL);
 933         grep_init(&opt, the_repository, prefix);
 934
 935         /*
 936          * If there is no -- then the paths must exist in the working
 937          * tree.  If there is no explicit pattern specified with -e or
 938          * -f, we take the first unrecognized non option to be the
 939          * pattern, but then what follows it must be zero or more
 940          * valid refs up to the -- (if exists), and then existing
 941          * paths.  If there is an explicit pattern, then the first
 942          * unrecognized non option is the beginning of the refs list
 943          * that continues up to the -- (if exists), and then paths.
 944          */
 945         argc = parse_options(argc, argv, prefix, options, grep_usage,
 946                              PARSE_OPT_KEEP_DASHDASH |
 947                              PARSE_OPT_STOP_AT_NON_OPTION);
 948         grep_commit_pattern_type(pattern_type_arg, &opt);
 949
 950         if (use_index && !startup_info->have_repository) {
 951                 int fallback = 0;
 952                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
 953                 if (fallback)
 954                         use_index = 0;
 955                 else
 956                         /* die the same way as if we did it at the beginning */
 957                         setup_git_directory();
 958         }
 959
 960         /*
 961          * skip a -- separator; we know it cannot be
 962          * separating revisions from pathnames if
 963          * we haven't even had any patterns yet
 964          */
 965         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 966                 argv++;
 967                 argc--;
 968         }
 969
 970         /* First unrecognized non-option token */
 971         if (argc > 0 && !opt.pattern_list) {
 972                 append_grep_pattern(&opt, argv[0], "command line", 0,
 973                                     GREP_PATTERN);
 974                 argv++;
 975                 argc--;
 976         }
 977
 978         if (show_in_pager == default_pager)
 979                 show_in_pager = git_pager(1);
 980         if (show_in_pager) {
 981                 opt.color = 0;
 982                 opt.name_only = 1;
 983                 opt.null_following_name = 1;
 984                 opt.output_priv = &path_list;
 985                 opt.output = append_path;
 986                 string_list_append(&path_list, show_in_pager);
 987         }
 988
 989         if (!opt.pattern_list)
 990                 die(_("no pattern given"));
 991
 992         /* --only-matching has no effect with --invert. */
 993         if (opt.invert)
 994                 opt.only_matching = 0;
 995
 996         /*
 997          * We have to find "--" in a separate pass, because its presence
 998          * influences how we will parse arguments that come before it.
 999          */
1000         for (i = 0; i < argc; i++) {
1001                 if (!strcmp(argv[i], "--")) {
1002                         seen_dashdash = 1;
1003                         break;
1004                 }
1005         }
1006
1007         /*
1008          * Resolve any rev arguments. If we have a dashdash, then everything up
1009          * to it must resolve as a rev. If not, then we stop at the first
1010          * non-rev and assume everything else is a path.
1011          */
1012         allow_revs = use_index && !untracked;
1013         for (i = 0; i < argc; i++) {
1014                 const char *arg = argv[i];
1015                 struct object_id oid;
1016                 struct object_context oc;
1017                 struct object *object;
1018
1019                 if (!strcmp(arg, "--")) {
1020                         i++;
1021                         break;
1022                 }
1023
1024                 if (!allow_revs) {
1025                         if (seen_dashdash)
1026                                 die(_("--no-index or --untracked cannot be used with revs"));
1027                         break;
1028                 }
1029
1030                 if (get_oid_with_context(the_repository, arg,
1031                                          GET_OID_RECORD_PATH,
1032                                          &oid, &oc)) {
1033                         if (seen_dashdash)
1034                                 die(_("unable to resolve revision: %s"), arg);
1035                         break;
1036                 }
1037
1038                 object = parse_object_or_die(&oid, arg);
1039                 if (!seen_dashdash)
1040                         verify_non_filename(prefix, arg);
1041                 add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
1042                 free(oc.path);
1043         }
1044
1045         /*
1046          * Anything left over is presumed to be a path. But in the non-dashdash
1047          * "do what I mean" case, we verify and complain when that isn't true.
1048          */
1049         if (!seen_dashdash) {
1050                 int j;
1051                 for (j = i; j < argc; j++)
1052                         verify_filename(prefix, argv[j], j == i && allow_revs);
1053         }
1054
1055         parse_pathspec(&pathspec, 0,
1056                        PATHSPEC_PREFER_CWD |
1057                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
1058                        prefix, argv + i);
1059         pathspec.max_depth = opt.max_depth;
1060         pathspec.recursive = 1;
1061         pathspec.recurse_submodules = !!recurse_submodules;
1062
1063         if (list.nr || cached || show_in_pager) {
1064                 if (num_threads > 1)
1065                         warning(_("invalid option combination, ignoring --threads"));
1066                 num_threads = 1;
1067         } else if (!HAVE_THREADS && num_threads > 1) {
1068                 warning(_("no threads support, ignoring --threads"));
1069                 num_threads = 1;
1070         } else if (num_threads < 0)
1071                 die(_("invalid number of threads specified (%d)"), num_threads);
1072         else if (num_threads == 0)
1073                 num_threads = HAVE_THREADS ? GREP_NUM_THREADS_DEFAULT : 1;
1074
1075         if (num_threads > 1) {
1076                 if (!HAVE_THREADS)
1077                         BUG("Somebody got num_threads calculation wrong!");
1078                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
1079                     && (opt.pre_context || opt.post_context ||
1080                         opt.file_break || opt.funcbody))
1081                         skip_first_line = 1;
1082                 start_threads(&opt);
1083         } else {
1084                 /*
1085                  * The compiled patterns on the main path are only
1086                  * used when not using threading. Otherwise
1087                  * start_threads() above calls compile_grep_patterns()
1088                  * for each thread.
1089                  */
1090                 compile_grep_patterns(&opt);
1091         }
1092
1093         if (show_in_pager && (cached || list.nr))
1094                 die(_("--open-files-in-pager only works on the worktree"));
1095
1096         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
1097                 const char *pager = path_list.items[0].string;
1098                 int len = strlen(pager);
1099
1100                 if (len > 4 && is_dir_sep(pager[len - 5]))
1101                         pager += len - 4;
1102
1103                 if (opt.ignore_case && !strcmp("less", pager))
1104                         string_list_append(&path_list, "-I");
1105
1106                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
1107                         struct strbuf buf = STRBUF_INIT;
1108                         strbuf_addf(&buf, "+/%s%s",
1109                                         strcmp("less", pager) ? "" : "*",
1110                                         opt.pattern_list->pattern);
1111                         string_list_append(&path_list, buf.buf);
1112                         strbuf_detach(&buf, NULL);
1113                 }
1114         }
1115
1116         if (recurse_submodules && (!use_index || untracked))
1117                 die(_("option not supported with --recurse-submodules"));
1118
1119         if (!show_in_pager && !opt.status_only)
1120                 setup_pager();
1121
1122         if (!use_index && (untracked || cached))
1123                 die(_("--cached or --untracked cannot be used with --no-index"));
1124
1125         if (!use_index || untracked) {
1126                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
1127                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
1128         } else if (0 <= opt_exclude) {
1129                 die(_("--[no-]exclude-standard cannot be used for tracked contents"));
1130         } else if (!list.nr) {
1131                 if (!cached)
1132                         setup_work_tree();
1133
1134                 hit = grep_cache(&opt, &pathspec, cached);
1135         } else {
1136                 if (cached)
1137                         die(_("both --cached and trees are given"));
1138
1139                 hit = grep_objects(&opt, &pathspec, &list);
1140         }
1141
1142         if (num_threads > 1)
1143                 hit |= wait_all();
1144         if (hit && show_in_pager)
1145                 run_pager(&opt, prefix);
1146         clear_pathspec(&pathspec);
1147         free_grep_patterns(&opt);
1148         return !hit;
1149 }