Pileus Git - ~andy/git/blob - builtin/grep.c

   1 /*
   2  * Builtin "git grep"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "blob.h"
   8 #include "tree.h"
   9 #include "commit.h"
  10 #include "tag.h"
  11 #include "tree-walk.h"
  12 #include "builtin.h"
  13 #include "parse-options.h"
  14 #include "string-list.h"
  15 #include "run-command.h"
  16 #include "userdiff.h"
  17 #include "grep.h"
  18 #include "quote.h"
  19 #include "dir.h"
  20
  21 static char const * const grep_usage[] = {
  22         "git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]",
  23         NULL
  24 };
  25
  26 static int use_threads = 1;
  27
  28 #ifndef NO_PTHREADS
  29 #define THREADS 8
  30 static pthread_t threads[THREADS];
  31
  32 /* We use one producer thread and THREADS consumer
  33  * threads. The producer adds struct work_items to 'todo' and the
  34  * consumers pick work items from the same array.
  35  */
  36 struct work_item {
  37         struct grep_source source;
  38         char done;
  39         struct strbuf out;
  40 };
  41
  42 /* In the range [todo_done, todo_start) in 'todo' we have work_items
  43  * that have been or are processed by a consumer thread. We haven't
  44  * written the result for these to stdout yet.
  45  *
  46  * The work_items in [todo_start, todo_end) are waiting to be picked
  47  * up by a consumer thread.
  48  *
  49  * The ranges are modulo TODO_SIZE.
  50  */
  51 #define TODO_SIZE 128
  52 static struct work_item todo[TODO_SIZE];
  53 static int todo_start;
  54 static int todo_end;
  55 static int todo_done;
  56
  57 /* Has all work items been added? */
  58 static int all_work_added;
  59
  60 /* This lock protects all the variables above. */
  61 static pthread_mutex_t grep_mutex;
  62
  63 static inline void grep_lock(void)
  64 {
  65         if (use_threads)
  66                 pthread_mutex_lock(&grep_mutex);
  67 }
  68
  69 static inline void grep_unlock(void)
  70 {
  71         if (use_threads)
  72                 pthread_mutex_unlock(&grep_mutex);
  73 }
  74
  75 /* Signalled when a new work_item is added to todo. */
  76 static pthread_cond_t cond_add;
  77
  78 /* Signalled when the result from one work_item is written to
  79  * stdout.
  80  */
  81 static pthread_cond_t cond_write;
  82
  83 /* Signalled when we are finished with everything. */
  84 static pthread_cond_t cond_result;
  85
  86 static int skip_first_line;
  87
  88 static void add_work(struct grep_opt *opt, enum grep_source_type type,
  89                      const char *name, const void *id)
  90 {
  91         grep_lock();
  92
  93         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
  94                 pthread_cond_wait(&cond_write, &grep_mutex);
  95         }
  96
  97         grep_source_init(&todo[todo_end].source, type, name, id);
  98         if (opt->binary != GREP_BINARY_TEXT)
  99                 grep_source_load_driver(&todo[todo_end].source);
 100         todo[todo_end].done = 0;
 101         strbuf_reset(&todo[todo_end].out);
 102         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 103
 104         pthread_cond_signal(&cond_add);
 105         grep_unlock();
 106 }
 107
 108 static struct work_item *get_work(void)
 109 {
 110         struct work_item *ret;
 111
 112         grep_lock();
 113         while (todo_start == todo_end && !all_work_added) {
 114                 pthread_cond_wait(&cond_add, &grep_mutex);
 115         }
 116
 117         if (todo_start == todo_end && all_work_added) {
 118                 ret = NULL;
 119         } else {
 120                 ret = &todo[todo_start];
 121                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 122         }
 123         grep_unlock();
 124         return ret;
 125 }
 126
 127 static void work_done(struct work_item *w)
 128 {
 129         int old_done;
 130
 131         grep_lock();
 132         w->done = 1;
 133         old_done = todo_done;
 134         for(; todo[todo_done].done && todo_done != todo_start;
 135             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 136                 w = &todo[todo_done];
 137                 if (w->out.len) {
 138                         const char *p = w->out.buf;
 139                         size_t len = w->out.len;
 140
 141                         /* Skip the leading hunk mark of the first file. */
 142                         if (skip_first_line) {
 143                                 while (len) {
 144                                         len--;
 145                                         if (*p++ == '\n')
 146                                                 break;
 147                                 }
 148                                 skip_first_line = 0;
 149                         }
 150
 151                         write_or_die(1, p, len);
 152                 }
 153                 grep_source_clear(&w->source);
 154         }
 155
 156         if (old_done != todo_done)
 157                 pthread_cond_signal(&cond_write);
 158
 159         if (all_work_added && todo_done == todo_end)
 160                 pthread_cond_signal(&cond_result);
 161
 162         grep_unlock();
 163 }
 164
 165 static void *run(void *arg)
 166 {
 167         int hit = 0;
 168         struct grep_opt *opt = arg;
 169
 170         while (1) {
 171                 struct work_item *w = get_work();
 172                 if (!w)
 173                         break;
 174
 175                 opt->output_priv = w;
 176                 hit |= grep_source(opt, &w->source);
 177                 grep_source_clear_data(&w->source);
 178                 work_done(w);
 179         }
 180         free_grep_patterns(arg);
 181         free(arg);
 182
 183         return (void*) (intptr_t) hit;
 184 }
 185
 186 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 187 {
 188         struct work_item *w = opt->output_priv;
 189         strbuf_add(&w->out, buf, size);
 190 }
 191
 192 static void start_threads(struct grep_opt *opt)
 193 {
 194         int i;
 195
 196         pthread_mutex_init(&grep_mutex, NULL);
 197         pthread_mutex_init(&grep_read_mutex, NULL);
 198         pthread_mutex_init(&grep_attr_mutex, NULL);
 199         pthread_cond_init(&cond_add, NULL);
 200         pthread_cond_init(&cond_write, NULL);
 201         pthread_cond_init(&cond_result, NULL);
 202         grep_use_locks = 1;
 203
 204         for (i = 0; i < ARRAY_SIZE(todo); i++) {
 205                 strbuf_init(&todo[i].out, 0);
 206         }
 207
 208         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 209                 int err;
 210                 struct grep_opt *o = grep_opt_dup(opt);
 211                 o->output = strbuf_out;
 212                 o->debug = 0;
 213                 compile_grep_patterns(o);
 214                 err = pthread_create(&threads[i], NULL, run, o);
 215
 216                 if (err)
 217                         die(_("grep: failed to create thread: %s"),
 218                             strerror(err));
 219         }
 220 }
 221
 222 static int wait_all(void)
 223 {
 224         int hit = 0;
 225         int i;
 226
 227         grep_lock();
 228         all_work_added = 1;
 229
 230         /* Wait until all work is done. */
 231         while (todo_done != todo_end)
 232                 pthread_cond_wait(&cond_result, &grep_mutex);
 233
 234         /* Wake up all the consumer threads so they can see that there
 235          * is no more work to do.
 236          */
 237         pthread_cond_broadcast(&cond_add);
 238         grep_unlock();
 239
 240         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 241                 void *h;
 242                 pthread_join(threads[i], &h);
 243                 hit |= (int) (intptr_t) h;
 244         }
 245
 246         pthread_mutex_destroy(&grep_mutex);
 247         pthread_mutex_destroy(&grep_read_mutex);
 248         pthread_mutex_destroy(&grep_attr_mutex);
 249         pthread_cond_destroy(&cond_add);
 250         pthread_cond_destroy(&cond_write);
 251         pthread_cond_destroy(&cond_result);
 252         grep_use_locks = 0;
 253
 254         return hit;
 255 }
 256 #else /* !NO_PTHREADS */
 257
 258 static int wait_all(void)
 259 {
 260         return 0;
 261 }
 262 #endif
 263
 264 static int grep_config(const char *var, const char *value, void *cb)
 265 {
 266         struct grep_opt *opt = cb;
 267         char *color = NULL;
 268
 269         if (userdiff_config(var, value) < 0)
 270                 return -1;
 271
 272         if (!strcmp(var, "grep.extendedregexp")) {
 273                 if (git_config_bool(var, value))
 274                         opt->regflags |= REG_EXTENDED;
 275                 else
 276                         opt->regflags &= ~REG_EXTENDED;
 277                 return 0;
 278         }
 279
 280         if (!strcmp(var, "grep.linenumber")) {
 281                 opt->linenum = git_config_bool(var, value);
 282                 return 0;
 283         }
 284
 285         if (!strcmp(var, "color.grep"))
 286                 opt->color = git_config_colorbool(var, value);
 287         else if (!strcmp(var, "color.grep.context"))
 288                 color = opt->color_context;
 289         else if (!strcmp(var, "color.grep.filename"))
 290                 color = opt->color_filename;
 291         else if (!strcmp(var, "color.grep.function"))
 292                 color = opt->color_function;
 293         else if (!strcmp(var, "color.grep.linenumber"))
 294                 color = opt->color_lineno;
 295         else if (!strcmp(var, "color.grep.match"))
 296                 color = opt->color_match;
 297         else if (!strcmp(var, "color.grep.selected"))
 298                 color = opt->color_selected;
 299         else if (!strcmp(var, "color.grep.separator"))
 300                 color = opt->color_sep;
 301         else
 302                 return git_color_default_config(var, value, cb);
 303         if (color) {
 304                 if (!value)
 305                         return config_error_nonbool(var);
 306                 color_parse(value, var, color);
 307         }
 308         return 0;
 309 }
 310
 311 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 312 {
 313         void *data;
 314
 315         grep_read_lock();
 316         data = read_sha1_file(sha1, type, size);
 317         grep_read_unlock();
 318         return data;
 319 }
 320
 321 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 322                      const char *filename, int tree_name_len)
 323 {
 324         struct strbuf pathbuf = STRBUF_INIT;
 325
 326         if (opt->relative && opt->prefix_length) {
 327                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
 328                                     opt->prefix);
 329                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 330         } else {
 331                 strbuf_addstr(&pathbuf, filename);
 332         }
 333
 334 #ifndef NO_PTHREADS
 335         if (use_threads) {
 336                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 337                 strbuf_release(&pathbuf);
 338                 return 0;
 339         } else
 340 #endif
 341         {
 342                 struct grep_source gs;
 343                 int hit;
 344
 345                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 346                 strbuf_release(&pathbuf);
 347                 hit = grep_source(opt, &gs);
 348
 349                 grep_source_clear(&gs);
 350                 return hit;
 351         }
 352 }
 353
 354 static int grep_file(struct grep_opt *opt, const char *filename)
 355 {
 356         struct strbuf buf = STRBUF_INIT;
 357
 358         if (opt->relative && opt->prefix_length)
 359                 quote_path_relative(filename, -1, &buf, opt->prefix);
 360         else
 361                 strbuf_addstr(&buf, filename);
 362
 363 #ifndef NO_PTHREADS
 364         if (use_threads) {
 365                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename);
 366                 strbuf_release(&buf);
 367                 return 0;
 368         } else
 369 #endif
 370         {
 371                 struct grep_source gs;
 372                 int hit;
 373
 374                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename);
 375                 strbuf_release(&buf);
 376                 hit = grep_source(opt, &gs);
 377
 378                 grep_source_clear(&gs);
 379                 return hit;
 380         }
 381 }
 382
 383 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 384 {
 385         struct string_list *path_list = opt->output_priv;
 386
 387         if (len == 1 && *(const char *)data == '\0')
 388                 return;
 389         string_list_append(path_list, xstrndup(data, len));
 390 }
 391
 392 static void run_pager(struct grep_opt *opt, const char *prefix)
 393 {
 394         struct string_list *path_list = opt->output_priv;
 395         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 396         int i, status;
 397
 398         for (i = 0; i < path_list->nr; i++)
 399                 argv[i] = path_list->items[i].string;
 400         argv[path_list->nr] = NULL;
 401
 402         if (prefix && chdir(prefix))
 403                 die(_("Failed to chdir: %s"), prefix);
 404         status = run_command_v_opt(argv, RUN_USING_SHELL);
 405         if (status)
 406                 exit(status);
 407         free(argv);
 408 }
 409
 410 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 411 {
 412         int hit = 0;
 413         int nr;
 414         read_cache();
 415
 416         for (nr = 0; nr < active_nr; nr++) {
 417                 struct cache_entry *ce = active_cache[nr];
 418                 if (!S_ISREG(ce->ce_mode))
 419                         continue;
 420                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 421                         continue;
 422                 /*
 423                  * If CE_VALID is on, we assume worktree file and its cache entry
 424                  * are identical, even if worktree file has been modified, so use
 425                  * cache version instead
 426                  */
 427                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 428                         if (ce_stage(ce))
 429                                 continue;
 430                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 431                 }
 432                 else
 433                         hit |= grep_file(opt, ce->name);
 434                 if (ce_stage(ce)) {
 435                         do {
 436                                 nr++;
 437                         } while (nr < active_nr &&
 438                                  !strcmp(ce->name, active_cache[nr]->name));
 439                         nr--; /* compensate for loop control */
 440                 }
 441                 if (hit && opt->status_only)
 442                         break;
 443         }
 444         return hit;
 445 }
 446
 447 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 448                      struct tree_desc *tree, struct strbuf *base, int tn_len)
 449 {
 450         int hit = 0;
 451         enum interesting match = entry_not_interesting;
 452         struct name_entry entry;
 453         int old_baselen = base->len;
 454
 455         while (tree_entry(tree, &entry)) {
 456                 int te_len = tree_entry_len(&entry);
 457
 458                 if (match != all_entries_interesting) {
 459                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 460                         if (match == all_entries_not_interesting)
 461                                 break;
 462                         if (match == entry_not_interesting)
 463                                 continue;
 464                 }
 465
 466                 strbuf_add(base, entry.path, te_len);
 467
 468                 if (S_ISREG(entry.mode)) {
 469                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
 470                 }
 471                 else if (S_ISDIR(entry.mode)) {
 472                         enum object_type type;
 473                         struct tree_desc sub;
 474                         void *data;
 475                         unsigned long size;
 476
 477                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 478                         if (!data)
 479                                 die(_("unable to read tree (%s)"),
 480                                     sha1_to_hex(entry.sha1));
 481
 482                         strbuf_addch(base, '/');
 483                         init_tree_desc(&sub, data, size);
 484                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
 485                         free(data);
 486                 }
 487                 strbuf_setlen(base, old_baselen);
 488
 489                 if (hit && opt->status_only)
 490                         break;
 491         }
 492         return hit;
 493 }
 494
 495 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 496                        struct object *obj, const char *name)
 497 {
 498         if (obj->type == OBJ_BLOB)
 499                 return grep_sha1(opt, obj->sha1, name, 0);
 500         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 501                 struct tree_desc tree;
 502                 void *data;
 503                 unsigned long size;
 504                 struct strbuf base;
 505                 int hit, len;
 506
 507                 grep_read_lock();
 508                 data = read_object_with_reference(obj->sha1, tree_type,
 509                                                   &size, NULL);
 510                 grep_read_unlock();
 511
 512                 if (!data)
 513                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 514
 515                 len = name ? strlen(name) : 0;
 516                 strbuf_init(&base, PATH_MAX + len + 1);
 517                 if (len) {
 518                         strbuf_add(&base, name, len);
 519                         strbuf_addch(&base, ':');
 520                 }
 521                 init_tree_desc(&tree, data, size);
 522                 hit = grep_tree(opt, pathspec, &tree, &base, base.len);
 523                 strbuf_release(&base);
 524                 free(data);
 525                 return hit;
 526         }
 527         die(_("unable to grep from object of type %s"), typename(obj->type));
 528 }
 529
 530 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 531                         const struct object_array *list)
 532 {
 533         unsigned int i;
 534         int hit = 0;
 535         const unsigned int nr = list->nr;
 536
 537         for (i = 0; i < nr; i++) {
 538                 struct object *real_obj;
 539                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
 540                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 541                         hit = 1;
 542                         if (opt->status_only)
 543                                 break;
 544                 }
 545         }
 546         return hit;
 547 }
 548
 549 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 550                           int exc_std)
 551 {
 552         struct dir_struct dir;
 553         int i, hit = 0;
 554
 555         memset(&dir, 0, sizeof(dir));
 556         if (exc_std)
 557                 setup_standard_excludes(&dir);
 558
 559         fill_directory(&dir, pathspec->raw);
 560         for (i = 0; i < dir.nr; i++) {
 561                 const char *name = dir.entries[i]->name;
 562                 int namelen = strlen(name);
 563                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 564                         continue;
 565                 hit |= grep_file(opt, dir.entries[i]->name);
 566                 if (hit && opt->status_only)
 567                         break;
 568         }
 569         return hit;
 570 }
 571
 572 static int context_callback(const struct option *opt, const char *arg,
 573                             int unset)
 574 {
 575         struct grep_opt *grep_opt = opt->value;
 576         int value;
 577         const char *endp;
 578
 579         if (unset) {
 580                 grep_opt->pre_context = grep_opt->post_context = 0;
 581                 return 0;
 582         }
 583         value = strtol(arg, (char **)&endp, 10);
 584         if (*endp) {
 585                 return error(_("switch `%c' expects a numerical value"),
 586                              opt->short_name);
 587         }
 588         grep_opt->pre_context = grep_opt->post_context = value;
 589         return 0;
 590 }
 591
 592 static int file_callback(const struct option *opt, const char *arg, int unset)
 593 {
 594         struct grep_opt *grep_opt = opt->value;
 595         int from_stdin = !strcmp(arg, "-");
 596         FILE *patterns;
 597         int lno = 0;
 598         struct strbuf sb = STRBUF_INIT;
 599
 600         patterns = from_stdin ? stdin : fopen(arg, "r");
 601         if (!patterns)
 602                 die_errno(_("cannot open '%s'"), arg);
 603         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 604                 /* ignore empty line like grep does */
 605                 if (sb.len == 0)
 606                         continue;
 607
 608                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 609                                 GREP_PATTERN);
 610         }
 611         if (!from_stdin)
 612                 fclose(patterns);
 613         strbuf_release(&sb);
 614         return 0;
 615 }
 616
 617 static int not_callback(const struct option *opt, const char *arg, int unset)
 618 {
 619         struct grep_opt *grep_opt = opt->value;
 620         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 621         return 0;
 622 }
 623
 624 static int and_callback(const struct option *opt, const char *arg, int unset)
 625 {
 626         struct grep_opt *grep_opt = opt->value;
 627         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 628         return 0;
 629 }
 630
 631 static int open_callback(const struct option *opt, const char *arg, int unset)
 632 {
 633         struct grep_opt *grep_opt = opt->value;
 634         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 635         return 0;
 636 }
 637
 638 static int close_callback(const struct option *opt, const char *arg, int unset)
 639 {
 640         struct grep_opt *grep_opt = opt->value;
 641         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 642         return 0;
 643 }
 644
 645 static int pattern_callback(const struct option *opt, const char *arg,
 646                             int unset)
 647 {
 648         struct grep_opt *grep_opt = opt->value;
 649         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 650         return 0;
 651 }
 652
 653 static int help_callback(const struct option *opt, const char *arg, int unset)
 654 {
 655         return -1;
 656 }
 657
 658 int cmd_grep(int argc, const char **argv, const char *prefix)
 659 {
 660         int hit = 0;
 661         int cached = 0, untracked = 0, opt_exclude = -1;
 662         int seen_dashdash = 0;
 663         int external_grep_allowed__ignored;
 664         const char *show_in_pager = NULL, *default_pager = "dummy";
 665         struct grep_opt opt;
 666         struct object_array list = OBJECT_ARRAY_INIT;
 667         const char **paths = NULL;
 668         struct pathspec pathspec;
 669         struct string_list path_list = STRING_LIST_INIT_NODUP;
 670         int i;
 671         int dummy;
 672         int use_index = 1;
 673         enum {
 674                 pattern_type_unspecified = 0,
 675                 pattern_type_bre,
 676                 pattern_type_ere,
 677                 pattern_type_fixed,
 678                 pattern_type_pcre,
 679         };
 680         int pattern_type = pattern_type_unspecified;
 681
 682         struct option options[] = {
 683                 OPT_BOOLEAN(0, "cached", &cached,
 684                         "search in index instead of in the work tree"),
 685                 OPT_NEGBIT(0, "no-index", &use_index,
 686                          "finds in contents not managed by git", 1),
 687                 OPT_BOOLEAN(0, "untracked", &untracked,
 688                         "search in both tracked and untracked files"),
 689                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 690                             "search also in ignored files", 1),
 691                 OPT_GROUP(""),
 692                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 693                         "show non-matching lines"),
 694                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 695                         "case insensitive matching"),
 696                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 697                         "match patterns only at word boundaries"),
 698                 OPT_SET_INT('a', "text", &opt.binary,
 699                         "process binary files as text", GREP_BINARY_TEXT),
 700                 OPT_SET_INT('I', NULL, &opt.binary,
 701                         "don't match patterns in binary files",
 702                         GREP_BINARY_NOMATCH),
 703                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
 704                         "descend at most <depth> levels", PARSE_OPT_NONEG,
 705                         NULL, 1 },
 706                 OPT_GROUP(""),
 707                 OPT_SET_INT('E', "extended-regexp", &pattern_type,
 708                             "use extended POSIX regular expressions",
 709                             pattern_type_ere),
 710                 OPT_SET_INT('G', "basic-regexp", &pattern_type,
 711                             "use basic POSIX regular expressions (default)",
 712                             pattern_type_bre),
 713                 OPT_SET_INT('F', "fixed-strings", &pattern_type,
 714                             "interpret patterns as fixed strings",
 715                             pattern_type_fixed),
 716                 OPT_SET_INT('P', "perl-regexp", &pattern_type,
 717                             "use Perl-compatible regular expressions",
 718                             pattern_type_pcre),
 719                 OPT_GROUP(""),
 720                 OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
 721                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 722                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 723                 OPT_NEGBIT(0, "full-name", &opt.relative,
 724                         "show filenames relative to top directory", 1),
 725                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 726                         "show only filenames instead of matching lines"),
 727                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 728                         "synonym for --files-with-matches"),
 729                 OPT_BOOLEAN('L', "files-without-match",
 730                         &opt.unmatch_name_only,
 731                         "show only the names of files without match"),
 732                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 733                         "print NUL after filenames"),
 734                 OPT_BOOLEAN('c', "count", &opt.count,
 735                         "show the number of matches instead of matching lines"),
 736                 OPT__COLOR(&opt.color, "highlight matches"),
 737                 OPT_BOOLEAN(0, "break", &opt.file_break,
 738                         "print empty line between matches from different files"),
 739                 OPT_BOOLEAN(0, "heading", &opt.heading,
 740                         "show filename only once above matches from same file"),
 741                 OPT_GROUP(""),
 742                 OPT_CALLBACK('C', "context", &opt, "n",
 743                         "show <n> context lines before and after matches",
 744                         context_callback),
 745                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 746                         "show <n> context lines before matches"),
 747                 OPT_INTEGER('A', "after-context", &opt.post_context,
 748                         "show <n> context lines after matches"),
 749                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 750                         context_callback),
 751                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 752                         "show a line with the function name before matches"),
 753                 OPT_BOOLEAN('W', "function-context", &opt.funcbody,
 754                         "show the surrounding function"),
 755                 OPT_GROUP(""),
 756                 OPT_CALLBACK('f', NULL, &opt, "file",
 757                         "read patterns from file", file_callback),
 758                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 759                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 760                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 761                   "combine patterns specified with -e",
 762                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 763                 OPT_BOOLEAN(0, "or", &dummy, ""),
 764                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 765                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 766                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 767                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 768                   open_callback },
 769                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 770                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 771                   close_callback },
 772                 OPT__QUIET(&opt.status_only,
 773                            "indicate hit with exit status without output"),
 774                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 775                         "show only matches from files that match all patterns"),
 776                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 777                   "show parse tree for grep expression",
 778                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 779                 OPT_GROUP(""),
 780                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 781                         "pager", "show matching files in the pager",
 782                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 783                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
 784                             "allow calling of grep(1) (ignored by this build)"),
 785                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 786                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 787                 OPT_END()
 788         };
 789
 790         /*
 791          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 792          * to show usage information and exit.
 793          */
 794         if (argc == 2 && !strcmp(argv[1], "-h"))
 795                 usage_with_options(grep_usage, options);
 796
 797         memset(&opt, 0, sizeof(opt));
 798         opt.prefix = prefix;
 799         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 800         opt.relative = 1;
 801         opt.pathname = 1;
 802         opt.pattern_tail = &opt.pattern_list;
 803         opt.header_tail = &opt.header_list;
 804         opt.regflags = REG_NEWLINE;
 805         opt.max_depth = -1;
 806
 807         strcpy(opt.color_context, "");
 808         strcpy(opt.color_filename, "");
 809         strcpy(opt.color_function, "");
 810         strcpy(opt.color_lineno, "");
 811         strcpy(opt.color_match, GIT_COLOR_BOLD_RED);
 812         strcpy(opt.color_selected, "");
 813         strcpy(opt.color_sep, GIT_COLOR_CYAN);
 814         opt.color = -1;
 815         git_config(grep_config, &opt);
 816
 817         /*
 818          * If there is no -- then the paths must exist in the working
 819          * tree.  If there is no explicit pattern specified with -e or
 820          * -f, we take the first unrecognized non option to be the
 821          * pattern, but then what follows it must be zero or more
 822          * valid refs up to the -- (if exists), and then existing
 823          * paths.  If there is an explicit pattern, then the first
 824          * unrecognized non option is the beginning of the refs list
 825          * that continues up to the -- (if exists), and then paths.
 826          */
 827         argc = parse_options(argc, argv, prefix, options, grep_usage,
 828                              PARSE_OPT_KEEP_DASHDASH |
 829                              PARSE_OPT_STOP_AT_NON_OPTION |
 830                              PARSE_OPT_NO_INTERNAL_HELP);
 831         switch (pattern_type) {
 832         case pattern_type_fixed:
 833                 opt.fixed = 1;
 834                 opt.pcre = 0;
 835                 break;
 836         case pattern_type_bre:
 837                 opt.fixed = 0;
 838                 opt.pcre = 0;
 839                 opt.regflags &= ~REG_EXTENDED;
 840                 break;
 841         case pattern_type_ere:
 842                 opt.fixed = 0;
 843                 opt.pcre = 0;
 844                 opt.regflags |= REG_EXTENDED;
 845                 break;
 846         case pattern_type_pcre:
 847                 opt.fixed = 0;
 848                 opt.pcre = 1;
 849                 break;
 850         default:
 851                 break; /* nothing */
 852         }
 853
 854         if (use_index && !startup_info->have_repository)
 855                 /* die the same way as if we did it at the beginning */
 856                 setup_git_directory();
 857
 858         /*
 859          * skip a -- separator; we know it cannot be
 860          * separating revisions from pathnames if
 861          * we haven't even had any patterns yet
 862          */
 863         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 864                 argv++;
 865                 argc--;
 866         }
 867
 868         /* First unrecognized non-option token */
 869         if (argc > 0 && !opt.pattern_list) {
 870                 append_grep_pattern(&opt, argv[0], "command line", 0,
 871                                     GREP_PATTERN);
 872                 argv++;
 873                 argc--;
 874         }
 875
 876         if (show_in_pager == default_pager)
 877                 show_in_pager = git_pager(1);
 878         if (show_in_pager) {
 879                 opt.color = 0;
 880                 opt.name_only = 1;
 881                 opt.null_following_name = 1;
 882                 opt.output_priv = &path_list;
 883                 opt.output = append_path;
 884                 string_list_append(&path_list, show_in_pager);
 885                 use_threads = 0;
 886         }
 887
 888         if (!opt.pattern_list)
 889                 die(_("no pattern given."));
 890         if (!opt.fixed && opt.ignore_case)
 891                 opt.regflags |= REG_ICASE;
 892
 893         compile_grep_patterns(&opt);
 894
 895         /* Check revs and then paths */
 896         for (i = 0; i < argc; i++) {
 897                 const char *arg = argv[i];
 898                 unsigned char sha1[20];
 899                 /* Is it a rev? */
 900                 if (!get_sha1(arg, sha1)) {
 901                         struct object *object = parse_object(sha1);
 902                         if (!object)
 903                                 die(_("bad object %s"), arg);
 904                         add_object_array(object, arg, &list);
 905                         continue;
 906                 }
 907                 if (!strcmp(arg, "--")) {
 908                         i++;
 909                         seen_dashdash = 1;
 910                 }
 911                 break;
 912         }
 913
 914 #ifndef NO_PTHREADS
 915         if (list.nr || cached || online_cpus() == 1)
 916                 use_threads = 0;
 917 #else
 918         use_threads = 0;
 919 #endif
 920
 921 #ifndef NO_PTHREADS
 922         if (use_threads) {
 923                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 924                     && (opt.pre_context || opt.post_context ||
 925                         opt.file_break || opt.funcbody))
 926                         skip_first_line = 1;
 927                 start_threads(&opt);
 928         }
 929 #endif
 930
 931         /* The rest are paths */
 932         if (!seen_dashdash) {
 933                 int j;
 934                 for (j = i; j < argc; j++)
 935                         verify_filename(prefix, argv[j], j == i);
 936         }
 937
 938         paths = get_pathspec(prefix, argv + i);
 939         init_pathspec(&pathspec, paths);
 940         pathspec.max_depth = opt.max_depth;
 941         pathspec.recursive = 1;
 942
 943         if (show_in_pager && (cached || list.nr))
 944                 die(_("--open-files-in-pager only works on the worktree"));
 945
 946         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 947                 const char *pager = path_list.items[0].string;
 948                 int len = strlen(pager);
 949
 950                 if (len > 4 && is_dir_sep(pager[len - 5]))
 951                         pager += len - 4;
 952
 953                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 954                         struct strbuf buf = STRBUF_INIT;
 955                         strbuf_addf(&buf, "+/%s%s",
 956                                         strcmp("less", pager) ? "" : "*",
 957                                         opt.pattern_list->pattern);
 958                         string_list_append(&path_list, buf.buf);
 959                         strbuf_detach(&buf, NULL);
 960                 }
 961         }
 962
 963         if (!show_in_pager)
 964                 setup_pager();
 965
 966         if (!use_index && (untracked || cached))
 967                 die(_("--cached or --untracked cannot be used with --no-index."));
 968
 969         if (!use_index || untracked) {
 970                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 971                 if (list.nr)
 972                         die(_("--no-index or --untracked cannot be used with revs."));
 973                 hit = grep_directory(&opt, &pathspec, use_exclude);
 974         } else if (0 <= opt_exclude) {
 975                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 976         } else if (!list.nr) {
 977                 if (!cached)
 978                         setup_work_tree();
 979
 980                 hit = grep_cache(&opt, &pathspec, cached);
 981         } else {
 982                 if (cached)
 983                         die(_("both --cached and trees are given."));
 984                 hit = grep_objects(&opt, &pathspec, &list);
 985         }
 986
 987         if (use_threads)
 988                 hit |= wait_all();
 989         if (hit && show_in_pager)
 990                 run_pager(&opt, prefix);
 991         free_grep_patterns(&opt);
 992         return !hit;
 993 }