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   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 #include "packfile.h"
  28
  29 static char const * const grep_usage[] = {
  30         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
  31         NULL
  32 };
  33
  34 static int recurse_submodules;
  35
  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, struct grep_source *gs)
  95 {
  96         if (opt->binary != GREP_BINARY_TEXT)
  97                 grep_source_load_driver(gs, opt->repo->index);
  98
  99         grep_lock();
 100
 101         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
 102                 pthread_cond_wait(&cond_write, &grep_mutex);
 103         }
 104
 105         todo[todo_end].source = *gs;
 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_attr_mutex, NULL);
 204         pthread_cond_init(&cond_add, NULL);
 205         pthread_cond_init(&cond_write, NULL);
 206         pthread_cond_init(&cond_result, NULL);
 207         grep_use_locks = 1;
 208         enable_obj_read_lock();
 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_attr_mutex);
 261         pthread_cond_destroy(&cond_add);
 262         pthread_cond_destroy(&cond_write);
 263         pthread_cond_destroy(&cond_result);
 264         grep_use_locks = 0;
 265         disable_obj_read_lock();
 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 grep_source_name(struct grep_opt *opt, const char *filename,
 299                              int tree_name_len, struct strbuf *out)
 300 {
 301         strbuf_reset(out);
 302
 303         if (opt->null_following_name) {
 304                 if (opt->relative && opt->prefix_length) {
 305                         struct strbuf rel_buf = STRBUF_INIT;
 306                         const char *rel_name =
 307                                 relative_path(filename + tree_name_len,
 308                                               opt->prefix, &rel_buf);
 309
 310                         if (tree_name_len)
 311                                 strbuf_add(out, filename, tree_name_len);
 312
 313                         strbuf_addstr(out, rel_name);
 314                         strbuf_release(&rel_buf);
 315                 } else {
 316                         strbuf_addstr(out, filename);
 317                 }
 318                 return;
 319         }
 320
 321         if (opt->relative && opt->prefix_length)
 322                 quote_path_relative(filename + tree_name_len, opt->prefix, out);
 323         else
 324                 quote_c_style(filename + tree_name_len, out, NULL, 0);
 325
 326         if (tree_name_len)
 327                 strbuf_insert(out, 0, filename, tree_name_len);
 328 }
 329
 330 static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 331                      const char *filename, int tree_name_len,
 332                      const char *path)
 333 {
 334         struct strbuf pathbuf = STRBUF_INIT;
 335         struct grep_source gs;
 336
 337         grep_source_name(opt, filename, tree_name_len, &pathbuf);
 338         grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
 339         strbuf_release(&pathbuf);
 340
 341         if (num_threads > 1) {
 342                 /*
 343                  * add_work() copies gs and thus assumes ownership of
 344                  * its fields, so do not call grep_source_clear()
 345                  */
 346                 add_work(opt, &gs);
 347                 return 0;
 348         } else {
 349                 int hit;
 350
 351                 hit = grep_source(opt, &gs);
 352
 353                 grep_source_clear(&gs);
 354                 return hit;
 355         }
 356 }
 357
 358 static int grep_file(struct grep_opt *opt, const char *filename)
 359 {
 360         struct strbuf buf = STRBUF_INIT;
 361         struct grep_source gs;
 362
 363         grep_source_name(opt, filename, 0, &buf);
 364         grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
 365         strbuf_release(&buf);
 366
 367         if (num_threads > 1) {
 368                 /*
 369                  * add_work() copies gs and thus assumes ownership of
 370                  * its fields, so do not call grep_source_clear()
 371                  */
 372                 add_work(opt, &gs);
 373                 return 0;
 374         } else {
 375                 int hit;
 376
 377                 hit = grep_source(opt, &gs);
 378
 379                 grep_source_clear(&gs);
 380                 return hit;
 381         }
 382 }
 383
 384 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 385 {
 386         struct string_list *path_list = opt->output_priv;
 387
 388         if (len == 1 && *(const char *)data == '\0')
 389                 return;
 390         string_list_append(path_list, xstrndup(data, len));
 391 }
 392
 393 static void run_pager(struct grep_opt *opt, const char *prefix)
 394 {
 395         struct string_list *path_list = opt->output_priv;
 396         struct child_process child = CHILD_PROCESS_INIT;
 397         int i, status;
 398
 399         for (i = 0; i < path_list->nr; i++)
 400                 argv_array_push(&child.args, path_list->items[i].string);
 401         child.dir = prefix;
 402         child.use_shell = 1;
 403
 404         status = run_command(&child);
 405         if (status)
 406                 exit(status);
 407 }
 408
 409 static int grep_cache(struct grep_opt *opt,
 410                       const struct pathspec *pathspec, int cached);
 411 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 412                      struct tree_desc *tree, struct strbuf *base, int tn_len,
 413                      int check_attr);
 414
 415 static int grep_submodule(struct grep_opt *opt,
 416                           const struct pathspec *pathspec,
 417                           const struct object_id *oid,
 418                           const char *filename, const char *path, int cached)
 419 {
 420         struct repository subrepo;
 421         struct repository *superproject = opt->repo;
 422         const struct submodule *sub;
 423         struct grep_opt subopt;
 424         int hit;
 425
 426         sub = submodule_from_path(superproject, &null_oid, path);
 427
 428         if (!is_submodule_active(superproject, path))
 429                 return 0;
 430
 431         if (repo_submodule_init(&subrepo, superproject, sub))
 432                 return 0;
 433
 434         /*
 435          * NEEDSWORK: repo_read_gitmodules() might call
 436          * add_to_alternates_memory() via config_from_gitmodules(). This
 437          * operation causes a race condition with concurrent object readings
 438          * performed by the worker threads. That's why we need obj_read_lock()
 439          * here. It should be removed once it's no longer necessary to add the
 440          * subrepo's odbs to the in-memory alternates list.
 441          */
 442         obj_read_lock();
 443         repo_read_gitmodules(&subrepo, 0);
 444
 445         /*
 446          * NEEDSWORK: This adds the submodule's object directory to the list of
 447          * alternates for the single in-memory object store.  This has some bad
 448          * consequences for memory (processed objects will never be freed) and
 449          * performance (this increases the number of pack files git has to pay
 450          * attention to, to the sum of the number of pack files in all the
 451          * repositories processed so far).  This can be removed once the object
 452          * store is no longer global and instead is a member of the repository
 453          * object.
 454          */
 455         add_to_alternates_memory(subrepo.objects->odb->path);
 456         obj_read_unlock();
 457
 458         memcpy(&subopt, opt, sizeof(subopt));
 459         subopt.repo = &subrepo;
 460
 461         if (oid) {
 462                 struct object *object;
 463                 struct tree_desc tree;
 464                 void *data;
 465                 unsigned long size;
 466                 struct strbuf base = STRBUF_INIT;
 467
 468                 obj_read_lock();
 469                 object = parse_object_or_die(oid, oid_to_hex(oid));
 470                 obj_read_unlock();
 471                 data = read_object_with_reference(&subrepo,
 472                                                   &object->oid, tree_type,
 473                                                   &size, NULL);
 474                 if (!data)
 475                         die(_("unable to read tree (%s)"), oid_to_hex(&object->oid));
 476
 477                 strbuf_addstr(&base, filename);
 478                 strbuf_addch(&base, '/');
 479
 480                 init_tree_desc(&tree, data, size);
 481                 hit = grep_tree(&subopt, pathspec, &tree, &base, base.len,
 482                                 object->type == OBJ_COMMIT);
 483                 strbuf_release(&base);
 484                 free(data);
 485         } else {
 486                 hit = grep_cache(&subopt, pathspec, cached);
 487         }
 488
 489         repo_clear(&subrepo);
 490         return hit;
 491 }
 492
 493 static int grep_cache(struct grep_opt *opt,
 494                       const struct pathspec *pathspec, int cached)
 495 {
 496         struct repository *repo = opt->repo;
 497         int hit = 0;
 498         int nr;
 499         struct strbuf name = STRBUF_INIT;
 500         int name_base_len = 0;
 501         if (repo->submodule_prefix) {
 502                 name_base_len = strlen(repo->submodule_prefix);
 503                 strbuf_addstr(&name, repo->submodule_prefix);
 504         }
 505
 506         if (repo_read_index(repo) < 0)
 507                 die(_("index file corrupt"));
 508
 509         for (nr = 0; nr < repo->index->cache_nr; nr++) {
 510                 const struct cache_entry *ce = repo->index->cache[nr];
 511                 strbuf_setlen(&name, name_base_len);
 512                 strbuf_addstr(&name, ce->name);
 513
 514                 if (S_ISREG(ce->ce_mode) &&
 515                     match_pathspec(repo->index, pathspec, name.buf, name.len, 0, NULL,
 516                                    S_ISDIR(ce->ce_mode) ||
 517                                    S_ISGITLINK(ce->ce_mode))) {
 518                         /*
 519                          * If CE_VALID is on, we assume worktree file and its
 520                          * cache entry are identical, even if worktree file has
 521                          * been modified, so use cache version instead
 522                          */
 523                         if (cached || (ce->ce_flags & CE_VALID) ||
 524                             ce_skip_worktree(ce)) {
 525                                 if (ce_stage(ce) || ce_intent_to_add(ce))
 526                                         continue;
 527                                 hit |= grep_oid(opt, &ce->oid, name.buf,
 528                                                  0, name.buf);
 529                         } else {
 530                                 hit |= grep_file(opt, name.buf);
 531                         }
 532                 } else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
 533                            submodule_path_match(repo->index, pathspec, name.buf, NULL)) {
 534                         hit |= grep_submodule(opt, pathspec, NULL, ce->name,
 535                                               ce->name, cached);
 536                 } else {
 537                         continue;
 538                 }
 539
 540                 if (ce_stage(ce)) {
 541                         do {
 542                                 nr++;
 543                         } while (nr < repo->index->cache_nr &&
 544                                  !strcmp(ce->name, repo->index->cache[nr]->name));
 545                         nr--; /* compensate for loop control */
 546                 }
 547                 if (hit && opt->status_only)
 548                         break;
 549         }
 550
 551         strbuf_release(&name);
 552         return hit;
 553 }
 554
 555 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 556                      struct tree_desc *tree, struct strbuf *base, int tn_len,
 557                      int check_attr)
 558 {
 559         struct repository *repo = opt->repo;
 560         int hit = 0;
 561         enum interesting match = entry_not_interesting;
 562         struct name_entry entry;
 563         int old_baselen = base->len;
 564         struct strbuf name = STRBUF_INIT;
 565         int name_base_len = 0;
 566         if (repo->submodule_prefix) {
 567                 strbuf_addstr(&name, repo->submodule_prefix);
 568                 name_base_len = name.len;
 569         }
 570
 571         while (tree_entry(tree, &entry)) {
 572                 int te_len = tree_entry_len(&entry);
 573
 574                 if (match != all_entries_interesting) {
 575                         strbuf_addstr(&name, base->buf + tn_len);
 576                         match = tree_entry_interesting(repo->index,
 577                                                        &entry, &name,
 578                                                        0, pathspec);
 579                         strbuf_setlen(&name, name_base_len);
 580
 581                         if (match == all_entries_not_interesting)
 582                                 break;
 583                         if (match == entry_not_interesting)
 584                                 continue;
 585                 }
 586
 587                 strbuf_add(base, entry.path, te_len);
 588
 589                 if (S_ISREG(entry.mode)) {
 590                         hit |= grep_oid(opt, &entry.oid, base->buf, tn_len,
 591                                          check_attr ? base->buf + tn_len : NULL);
 592                 } else if (S_ISDIR(entry.mode)) {
 593                         enum object_type type;
 594                         struct tree_desc sub;
 595                         void *data;
 596                         unsigned long size;
 597
 598                         data = read_object_file(&entry.oid, &type, &size);
 599                         if (!data)
 600                                 die(_("unable to read tree (%s)"),
 601                                     oid_to_hex(&entry.oid));
 602
 603                         strbuf_addch(base, '/');
 604                         init_tree_desc(&sub, data, size);
 605                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
 606                                          check_attr);
 607                         free(data);
 608                 } else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
 609                         hit |= grep_submodule(opt, pathspec, &entry.oid,
 610                                               base->buf, base->buf + tn_len,
 611                                               1); /* ignored */
 612                 }
 613
 614                 strbuf_setlen(base, old_baselen);
 615
 616                 if (hit && opt->status_only)
 617                         break;
 618         }
 619
 620         strbuf_release(&name);
 621         return hit;
 622 }
 623
 624 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 625                        struct object *obj, const char *name, const char *path)
 626 {
 627         if (obj->type == OBJ_BLOB)
 628                 return grep_oid(opt, &obj->oid, name, 0, path);
 629         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 630                 struct tree_desc tree;
 631                 void *data;
 632                 unsigned long size;
 633                 struct strbuf base;
 634                 int hit, len;
 635
 636                 data = read_object_with_reference(opt->repo,
 637                                                   &obj->oid, tree_type,
 638                                                   &size, NULL);
 639                 if (!data)
 640                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
 641
 642                 len = name ? strlen(name) : 0;
 643                 strbuf_init(&base, PATH_MAX + len + 1);
 644                 if (len) {
 645                         strbuf_add(&base, name, len);
 646                         strbuf_addch(&base, ':');
 647                 }
 648                 init_tree_desc(&tree, data, size);
 649                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
 650                                 obj->type == OBJ_COMMIT);
 651                 strbuf_release(&base);
 652                 free(data);
 653                 return hit;
 654         }
 655         die(_("unable to grep from object of type %s"), type_name(obj->type));
 656 }
 657
 658 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 659                         const struct object_array *list)
 660 {
 661         unsigned int i;
 662         int hit = 0;
 663         const unsigned int nr = list->nr;
 664
 665         for (i = 0; i < nr; i++) {
 666                 struct object *real_obj;
 667
 668                 obj_read_lock();
 669                 real_obj = deref_tag(opt->repo, list->objects[i].item,
 670                                      NULL, 0);
 671                 obj_read_unlock();
 672
 673                 /* load the gitmodules file for this rev */
 674                 if (recurse_submodules) {
 675                         submodule_free(opt->repo);
 676                         obj_read_lock();
 677                         gitmodules_config_oid(&real_obj->oid);
 678                         obj_read_unlock();
 679                 }
 680                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
 681                                 list->objects[i].path)) {
 682                         hit = 1;
 683                         if (opt->status_only)
 684                                 break;
 685                 }
 686         }
 687         return hit;
 688 }
 689
 690 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 691                           int exc_std, int use_index)
 692 {
 693         struct dir_struct dir;
 694         int i, hit = 0;
 695
 696         memset(&dir, 0, sizeof(dir));
 697         if (!use_index)
 698                 dir.flags |= DIR_NO_GITLINKS;
 699         if (exc_std)
 700                 setup_standard_excludes(&dir);
 701
 702         fill_directory(&dir, opt->repo->index, pathspec);
 703         for (i = 0; i < dir.nr; i++) {
 704                 hit |= grep_file(opt, dir.entries[i]->name);
 705                 if (hit && opt->status_only)
 706                         break;
 707         }
 708         return hit;
 709 }
 710
 711 static int context_callback(const struct option *opt, const char *arg,
 712                             int unset)
 713 {
 714         struct grep_opt *grep_opt = opt->value;
 715         int value;
 716         const char *endp;
 717
 718         if (unset) {
 719                 grep_opt->pre_context = grep_opt->post_context = 0;
 720                 return 0;
 721         }
 722         value = strtol(arg, (char **)&endp, 10);
 723         if (*endp) {
 724                 return error(_("switch `%c' expects a numerical value"),
 725                              opt->short_name);
 726         }
 727         grep_opt->pre_context = grep_opt->post_context = value;
 728         return 0;
 729 }
 730
 731 static int file_callback(const struct option *opt, const char *arg, int unset)
 732 {
 733         struct grep_opt *grep_opt = opt->value;
 734         int from_stdin;
 735         FILE *patterns;
 736         int lno = 0;
 737         struct strbuf sb = STRBUF_INIT;
 738
 739         BUG_ON_OPT_NEG(unset);
 740
 741         from_stdin = !strcmp(arg, "-");
 742         patterns = from_stdin ? stdin : fopen(arg, "r");
 743         if (!patterns)
 744                 die_errno(_("cannot open '%s'"), arg);
 745         while (strbuf_getline(&sb, patterns) == 0) {
 746                 /* ignore empty line like grep does */
 747                 if (sb.len == 0)
 748                         continue;
 749
 750                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 751                                 GREP_PATTERN);
 752         }
 753         if (!from_stdin)
 754                 fclose(patterns);
 755         strbuf_release(&sb);
 756         return 0;
 757 }
 758
 759 static int not_callback(const struct option *opt, const char *arg, int unset)
 760 {
 761         struct grep_opt *grep_opt = opt->value;
 762         BUG_ON_OPT_NEG(unset);
 763         BUG_ON_OPT_ARG(arg);
 764         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 765         return 0;
 766 }
 767
 768 static int and_callback(const struct option *opt, const char *arg, int unset)
 769 {
 770         struct grep_opt *grep_opt = opt->value;
 771         BUG_ON_OPT_NEG(unset);
 772         BUG_ON_OPT_ARG(arg);
 773         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 774         return 0;
 775 }
 776
 777 static int open_callback(const struct option *opt, const char *arg, int unset)
 778 {
 779         struct grep_opt *grep_opt = opt->value;
 780         BUG_ON_OPT_NEG(unset);
 781         BUG_ON_OPT_ARG(arg);
 782         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 783         return 0;
 784 }
 785
 786 static int close_callback(const struct option *opt, const char *arg, int unset)
 787 {
 788         struct grep_opt *grep_opt = opt->value;
 789         BUG_ON_OPT_NEG(unset);
 790         BUG_ON_OPT_ARG(arg);
 791         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 792         return 0;
 793 }
 794
 795 static int pattern_callback(const struct option *opt, const char *arg,
 796                             int unset)
 797 {
 798         struct grep_opt *grep_opt = opt->value;
 799         BUG_ON_OPT_NEG(unset);
 800         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 801         return 0;
 802 }
 803
 804 int cmd_grep(int argc, const char **argv, const char *prefix)
 805 {
 806         int hit = 0;
 807         int cached = 0, untracked = 0, opt_exclude = -1;
 808         int seen_dashdash = 0;
 809         int external_grep_allowed__ignored;
 810         const char *show_in_pager = NULL, *default_pager = "dummy";
 811         struct grep_opt opt;
 812         struct object_array list = OBJECT_ARRAY_INIT;
 813         struct pathspec pathspec;
 814         struct string_list path_list = STRING_LIST_INIT_NODUP;
 815         int i;
 816         int dummy;
 817         int use_index = 1;
 818         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 819         int allow_revs;
 820
 821         struct option options[] = {
 822                 OPT_BOOL(0, "cached", &cached,
 823                         N_("search in index instead of in the work tree")),
 824                 OPT_NEGBIT(0, "no-index", &use_index,
 825                          N_("find in contents not managed by git"), 1),
 826                 OPT_BOOL(0, "untracked", &untracked,
 827                         N_("search in both tracked and untracked files")),
 828                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 829                             N_("ignore files specified via '.gitignore'"), 1),
 830                 OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
 831                          N_("recursively search in each submodule")),
 832                 OPT_GROUP(""),
 833                 OPT_BOOL('v', "invert-match", &opt.invert,
 834                         N_("show non-matching lines")),
 835                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
 836                         N_("case insensitive matching")),
 837                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
 838                         N_("match patterns only at word boundaries")),
 839                 OPT_SET_INT('a', "text", &opt.binary,
 840                         N_("process binary files as text"), GREP_BINARY_TEXT),
 841                 OPT_SET_INT('I', NULL, &opt.binary,
 842                         N_("don't match patterns in binary files"),
 843                         GREP_BINARY_NOMATCH),
 844                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
 845                          N_("process binary files with textconv filters")),
 846                 OPT_SET_INT('r', "recursive", &opt.max_depth,
 847                             N_("search in subdirectories (default)"), -1),
 848                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 849                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 850                         NULL, 1 },
 851                 OPT_GROUP(""),
 852                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 853                             N_("use extended POSIX regular expressions"),
 854                             GREP_PATTERN_TYPE_ERE),
 855                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 856                             N_("use basic POSIX regular expressions (default)"),
 857                             GREP_PATTERN_TYPE_BRE),
 858                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 859                             N_("interpret patterns as fixed strings"),
 860                             GREP_PATTERN_TYPE_FIXED),
 861                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 862                             N_("use Perl-compatible regular expressions"),
 863                             GREP_PATTERN_TYPE_PCRE),
 864                 OPT_GROUP(""),
 865                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
 866                 OPT_BOOL(0, "column", &opt.columnnum, N_("show column number of first match")),
 867                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 868                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 869                 OPT_NEGBIT(0, "full-name", &opt.relative,
 870                         N_("show filenames relative to top directory"), 1),
 871                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
 872                         N_("show only filenames instead of matching lines")),
 873                 OPT_BOOL(0, "name-only", &opt.name_only,
 874                         N_("synonym for --files-with-matches")),
 875                 OPT_BOOL('L', "files-without-match",
 876                         &opt.unmatch_name_only,
 877                         N_("show only the names of files without match")),
 878                 OPT_BOOL_F('z', "null", &opt.null_following_name,
 879                            N_("print NUL after filenames"),
 880                            PARSE_OPT_NOCOMPLETE),
 881                 OPT_BOOL('o', "only-matching", &opt.only_matching,
 882                         N_("show only matching parts of a line")),
 883                 OPT_BOOL('c', "count", &opt.count,
 884                         N_("show the number of matches instead of matching lines")),
 885                 OPT__COLOR(&opt.color, N_("highlight matches")),
 886                 OPT_BOOL(0, "break", &opt.file_break,
 887                         N_("print empty line between matches from different files")),
 888                 OPT_BOOL(0, "heading", &opt.heading,
 889                         N_("show filename only once above matches from same file")),
 890                 OPT_GROUP(""),
 891                 OPT_CALLBACK('C', "context", &opt, N_("n"),
 892                         N_("show <n> context lines before and after matches"),
 893                         context_callback),
 894                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 895                         N_("show <n> context lines before matches")),
 896                 OPT_INTEGER('A', "after-context", &opt.post_context,
 897                         N_("show <n> context lines after matches")),
 898                 OPT_INTEGER(0, "threads", &num_threads,
 899                         N_("use <n> worker threads")),
 900                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 901                         context_callback),
 902                 OPT_BOOL('p', "show-function", &opt.funcname,
 903                         N_("show a line with the function name before matches")),
 904                 OPT_BOOL('W', "function-context", &opt.funcbody,
 905                         N_("show the surrounding function")),
 906                 OPT_GROUP(""),
 907                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
 908                         N_("read patterns from file"), file_callback),
 909                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 910                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 911                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 912                   N_("combine patterns specified with -e"),
 913                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 914                 OPT_BOOL(0, "or", &dummy, ""),
 915                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 916                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 917                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 918                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 919                   open_callback },
 920                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 921                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 922                   close_callback },
 923                 OPT__QUIET(&opt.status_only,
 924                            N_("indicate hit with exit status without output")),
 925                 OPT_BOOL(0, "all-match", &opt.all_match,
 926                         N_("show only matches from files that match all patterns")),
 927                 OPT_SET_INT_F(0, "debug", &opt.debug,
 928                               N_("show parse tree for grep expression"),
 929                               1, PARSE_OPT_HIDDEN),
 930                 OPT_GROUP(""),
 931                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 932                         N_("pager"), N_("show matching files in the pager"),
 933                         PARSE_OPT_OPTARG | PARSE_OPT_NOCOMPLETE,
 934                         NULL, (intptr_t)default_pager },
 935                 OPT_BOOL_F(0, "ext-grep", &external_grep_allowed__ignored,
 936                            N_("allow calling of grep(1) (ignored by this build)"),
 937                            PARSE_OPT_NOCOMPLETE),
 938                 OPT_END()
 939         };
 940
 941         init_grep_defaults(the_repository);
 942         git_config(grep_cmd_config, NULL);
 943         grep_init(&opt, the_repository, prefix);
 944
 945         /*
 946          * If there is no -- then the paths must exist in the working
 947          * tree.  If there is no explicit pattern specified with -e or
 948          * -f, we take the first unrecognized non option to be the
 949          * pattern, but then what follows it must be zero or more
 950          * valid refs up to the -- (if exists), and then existing
 951          * paths.  If there is an explicit pattern, then the first
 952          * unrecognized non option is the beginning of the refs list
 953          * that continues up to the -- (if exists), and then paths.
 954          */
 955         argc = parse_options(argc, argv, prefix, options, grep_usage,
 956                              PARSE_OPT_KEEP_DASHDASH |
 957                              PARSE_OPT_STOP_AT_NON_OPTION);
 958         grep_commit_pattern_type(pattern_type_arg, &opt);
 959
 960         if (use_index && !startup_info->have_repository) {
 961                 int fallback = 0;
 962                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
 963                 if (fallback)
 964                         use_index = 0;
 965                 else
 966                         /* die the same way as if we did it at the beginning */
 967                         setup_git_directory();
 968         }
 969         /* Ignore --recurse-submodules if --no-index is given or implied */
 970         if (!use_index)
 971                 recurse_submodules = 0;
 972
 973         /*
 974          * skip a -- separator; we know it cannot be
 975          * separating revisions from pathnames if
 976          * we haven't even had any patterns yet
 977          */
 978         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 979                 argv++;
 980                 argc--;
 981         }
 982
 983         /* First unrecognized non-option token */
 984         if (argc > 0 && !opt.pattern_list) {
 985                 append_grep_pattern(&opt, argv[0], "command line", 0,
 986                                     GREP_PATTERN);
 987                 argv++;
 988                 argc--;
 989         }
 990
 991         if (show_in_pager == default_pager)
 992                 show_in_pager = git_pager(1);
 993         if (show_in_pager) {
 994                 opt.color = 0;
 995                 opt.name_only = 1;
 996                 opt.null_following_name = 1;
 997                 opt.output_priv = &path_list;
 998                 opt.output = append_path;
 999                 string_list_append(&path_list, show_in_pager);
1000         }
1001
1002         if (!opt.pattern_list)
1003                 die(_("no pattern given"));
1004
1005         /* --only-matching has no effect with --invert. */
1006         if (opt.invert)
1007                 opt.only_matching = 0;
1008
1009         /*
1010          * We have to find "--" in a separate pass, because its presence
1011          * influences how we will parse arguments that come before it.
1012          */
1013         for (i = 0; i < argc; i++) {
1014                 if (!strcmp(argv[i], "--")) {
1015                         seen_dashdash = 1;
1016                         break;
1017                 }
1018         }
1019
1020         /*
1021          * Resolve any rev arguments. If we have a dashdash, then everything up
1022          * to it must resolve as a rev. If not, then we stop at the first
1023          * non-rev and assume everything else is a path.
1024          */
1025         allow_revs = use_index && !untracked;
1026         for (i = 0; i < argc; i++) {
1027                 const char *arg = argv[i];
1028                 struct object_id oid;
1029                 struct object_context oc;
1030                 struct object *object;
1031
1032                 if (!strcmp(arg, "--")) {
1033                         i++;
1034                         break;
1035                 }
1036
1037                 if (!allow_revs) {
1038                         if (seen_dashdash)
1039                                 die(_("--no-index or --untracked cannot be used with revs"));
1040                         break;
1041                 }
1042
1043                 if (get_oid_with_context(the_repository, arg,
1044                                          GET_OID_RECORD_PATH,
1045                                          &oid, &oc)) {
1046                         if (seen_dashdash)
1047                                 die(_("unable to resolve revision: %s"), arg);
1048                         break;
1049                 }
1050
1051                 object = parse_object_or_die(&oid, arg);
1052                 if (!seen_dashdash)
1053                         verify_non_filename(prefix, arg);
1054                 add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
1055                 free(oc.path);
1056         }
1057
1058         /*
1059          * Anything left over is presumed to be a path. But in the non-dashdash
1060          * "do what I mean" case, we verify and complain when that isn't true.
1061          */
1062         if (!seen_dashdash) {
1063                 int j;
1064                 for (j = i; j < argc; j++)
1065                         verify_filename(prefix, argv[j], j == i && allow_revs);
1066         }
1067
1068         parse_pathspec(&pathspec, 0,
1069                        PATHSPEC_PREFER_CWD |
1070                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
1071                        prefix, argv + i);
1072         pathspec.max_depth = opt.max_depth;
1073         pathspec.recursive = 1;
1074         pathspec.recurse_submodules = !!recurse_submodules;
1075
1076         if (recurse_submodules && untracked)
1077                 die(_("--untracked not supported with --recurse-submodules"));
1078
1079         if (show_in_pager) {
1080                 if (num_threads > 1)
1081                         warning(_("invalid option combination, ignoring --threads"));
1082                 num_threads = 1;
1083         } else if (!HAVE_THREADS && num_threads > 1) {
1084                 warning(_("no threads support, ignoring --threads"));
1085                 num_threads = 1;
1086         } else if (num_threads < 0)
1087                 die(_("invalid number of threads specified (%d)"), num_threads);
1088         else if (num_threads == 0)
1089                 num_threads = HAVE_THREADS ? online_cpus() : 1;
1090
1091         if (num_threads > 1) {
1092                 if (!HAVE_THREADS)
1093                         BUG("Somebody got num_threads calculation wrong!");
1094                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
1095                     && (opt.pre_context || opt.post_context ||
1096                         opt.file_break || opt.funcbody))
1097                         skip_first_line = 1;
1098
1099                 /*
1100                  * Pre-read gitmodules (if not read already) and force eager
1101                  * initialization of packed_git to prevent racy lazy
1102                  * reading/initialization once worker threads are started.
1103                  */
1104                 if (recurse_submodules)
1105                         repo_read_gitmodules(the_repository, 1);
1106                 if (startup_info->have_repository)
1107                         (void)get_packed_git(the_repository);
1108
1109                 start_threads(&opt);
1110         } else {
1111                 /*
1112                  * The compiled patterns on the main path are only
1113                  * used when not using threading. Otherwise
1114                  * start_threads() above calls compile_grep_patterns()
1115                  * for each thread.
1116                  */
1117                 compile_grep_patterns(&opt);
1118         }
1119
1120         if (show_in_pager && (cached || list.nr))
1121                 die(_("--open-files-in-pager only works on the worktree"));
1122
1123         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
1124                 const char *pager = path_list.items[0].string;
1125                 int len = strlen(pager);
1126
1127                 if (len > 4 && is_dir_sep(pager[len - 5]))
1128                         pager += len - 4;
1129
1130                 if (opt.ignore_case && !strcmp("less", pager))
1131                         string_list_append(&path_list, "-I");
1132
1133                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
1134                         struct strbuf buf = STRBUF_INIT;
1135                         strbuf_addf(&buf, "+/%s%s",
1136                                         strcmp("less", pager) ? "" : "*",
1137                                         opt.pattern_list->pattern);
1138                         string_list_append(&path_list,
1139                                            strbuf_detach(&buf, NULL));
1140                 }
1141         }
1142
1143         if (!show_in_pager && !opt.status_only)
1144                 setup_pager();
1145
1146         if (!use_index && (untracked || cached))
1147                 die(_("--cached or --untracked cannot be used with --no-index"));
1148
1149         if (!use_index || untracked) {
1150                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
1151                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
1152         } else if (0 <= opt_exclude) {
1153                 die(_("--[no-]exclude-standard cannot be used for tracked contents"));
1154         } else if (!list.nr) {
1155                 if (!cached)
1156                         setup_work_tree();
1157
1158                 hit = grep_cache(&opt, &pathspec, cached);
1159         } else {
1160                 if (cached)
1161                         die(_("both --cached and trees are given"));
1162
1163                 hit = grep_objects(&opt, &pathspec, &list);
1164         }
1165
1166         if (num_threads > 1)
1167                 hit |= wait_all();
1168         if (hit && show_in_pager)
1169                 run_pager(&opt, prefix);
1170         clear_pathspec(&pathspec);
1171         free_grep_patterns(&opt);
1172         grep_destroy();
1173         return !hit;
1174 }