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 #include "pathspec.h"
  21 #include "attr.h"
  22
  23 static char const * const grep_usage[] = {
  24         N_("git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]"),
  25         NULL
  26 };
  27
  28 static int use_threads = 1;
  29
  30 #ifndef NO_PTHREADS
  31 #define THREADS 8
  32 static pthread_t threads[THREADS];
  33
  34 /* We use one producer thread and THREADS consumer
  35  * threads. The producer adds struct work_items to 'todo' and the
  36  * consumers pick work items from the same array.
  37  */
  38 struct work_item {
  39         struct grep_source source;
  40         char done;
  41         struct strbuf out;
  42 };
  43
  44 /* In the range [todo_done, todo_start) in 'todo' we have work_items
  45  * that have been or are processed by a consumer thread. We haven't
  46  * written the result for these to stdout yet.
  47  *
  48  * The work_items in [todo_start, todo_end) are waiting to be picked
  49  * up by a consumer thread.
  50  *
  51  * The ranges are modulo TODO_SIZE.
  52  */
  53 #define TODO_SIZE 128
  54 static struct work_item todo[TODO_SIZE];
  55 static int todo_start;
  56 static int todo_end;
  57 static int todo_done;
  58
  59 /* Has all work items been added? */
  60 static int all_work_added;
  61
  62 /* This lock protects all the variables above. */
  63 static pthread_mutex_t grep_mutex;
  64
  65 static inline void grep_lock(void)
  66 {
  67         if (use_threads)
  68                 pthread_mutex_lock(&grep_mutex);
  69 }
  70
  71 static inline void grep_unlock(void)
  72 {
  73         if (use_threads)
  74                 pthread_mutex_unlock(&grep_mutex);
  75 }
  76
  77 /* Signalled when a new work_item is added to todo. */
  78 static pthread_cond_t cond_add;
  79
  80 /* Signalled when the result from one work_item is written to
  81  * stdout.
  82  */
  83 static pthread_cond_t cond_write;
  84
  85 /* Signalled when we are finished with everything. */
  86 static pthread_cond_t cond_result;
  87
  88 static int skip_first_line;
  89
  90 static void add_work(struct grep_opt *opt, enum grep_source_type type,
  91                      const char *name, const char *path, const void *id)
  92 {
  93         grep_lock();
  94
  95         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
  96                 pthread_cond_wait(&cond_write, &grep_mutex);
  97         }
  98
  99         grep_source_init(&todo[todo_end].source, type, name, path, id);
 100         if (opt->binary != GREP_BINARY_TEXT)
 101                 grep_source_load_driver(&todo[todo_end].source);
 102         todo[todo_end].done = 0;
 103         strbuf_reset(&todo[todo_end].out);
 104         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 105
 106         pthread_cond_signal(&cond_add);
 107         grep_unlock();
 108 }
 109
 110 static struct work_item *get_work(void)
 111 {
 112         struct work_item *ret;
 113
 114         grep_lock();
 115         while (todo_start == todo_end && !all_work_added) {
 116                 pthread_cond_wait(&cond_add, &grep_mutex);
 117         }
 118
 119         if (todo_start == todo_end && all_work_added) {
 120                 ret = NULL;
 121         } else {
 122                 ret = &todo[todo_start];
 123                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 124         }
 125         grep_unlock();
 126         return ret;
 127 }
 128
 129 static void work_done(struct work_item *w)
 130 {
 131         int old_done;
 132
 133         grep_lock();
 134         w->done = 1;
 135         old_done = todo_done;
 136         for(; todo[todo_done].done && todo_done != todo_start;
 137             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 138                 w = &todo[todo_done];
 139                 if (w->out.len) {
 140                         const char *p = w->out.buf;
 141                         size_t len = w->out.len;
 142
 143                         /* Skip the leading hunk mark of the first file. */
 144                         if (skip_first_line) {
 145                                 while (len) {
 146                                         len--;
 147                                         if (*p++ == '\n')
 148                                                 break;
 149                                 }
 150                                 skip_first_line = 0;
 151                         }
 152
 153                         write_or_die(1, p, len);
 154                 }
 155                 grep_source_clear(&w->source);
 156         }
 157
 158         if (old_done != todo_done)
 159                 pthread_cond_signal(&cond_write);
 160
 161         if (all_work_added && todo_done == todo_end)
 162                 pthread_cond_signal(&cond_result);
 163
 164         grep_unlock();
 165 }
 166
 167 static int skip_binary(struct grep_opt *opt, const char *filename)
 168 {
 169         if ((opt->binary & GREP_BINARY_NOMATCH)) {
 170                 static struct git_attr *attr_text;
 171                 struct git_attr_check check;
 172
 173                 if (!attr_text)
 174                         attr_text = git_attr("text");
 175                 memset(&check, 0, sizeof(check));
 176                 check.attr = attr_text;
 177                 return !git_check_attr(filename, 1, &check) &&
 178                                 ATTR_FALSE(check.value);
 179         }
 180         return 0;
 181 }
 182
 183 static void *run(void *arg)
 184 {
 185         int hit = 0;
 186         struct grep_opt *opt = arg;
 187
 188         while (1) {
 189                 struct work_item *w = get_work();
 190                 if (!w)
 191                         break;
 192
 193                 if (skip_binary(opt, (const char *)w->source.identifier))
 194                         continue;
 195
 196                 opt->output_priv = w;
 197                 hit |= grep_source(opt, &w->source);
 198                 grep_source_clear_data(&w->source);
 199                 work_done(w);
 200         }
 201         free_grep_patterns(arg);
 202         free(arg);
 203
 204         return (void*) (intptr_t) hit;
 205 }
 206
 207 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 208 {
 209         struct work_item *w = opt->output_priv;
 210         strbuf_add(&w->out, buf, size);
 211 }
 212
 213 static void start_threads(struct grep_opt *opt)
 214 {
 215         int i;
 216
 217         pthread_mutex_init(&grep_mutex, NULL);
 218         pthread_mutex_init(&grep_read_mutex, NULL);
 219         pthread_mutex_init(&grep_attr_mutex, NULL);
 220         pthread_cond_init(&cond_add, NULL);
 221         pthread_cond_init(&cond_write, NULL);
 222         pthread_cond_init(&cond_result, NULL);
 223         grep_use_locks = 1;
 224
 225         for (i = 0; i < ARRAY_SIZE(todo); i++) {
 226                 strbuf_init(&todo[i].out, 0);
 227         }
 228
 229         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 230                 int err;
 231                 struct grep_opt *o = grep_opt_dup(opt);
 232                 o->output = strbuf_out;
 233                 o->debug = 0;
 234                 compile_grep_patterns(o);
 235                 err = pthread_create(&threads[i], NULL, run, o);
 236
 237                 if (err)
 238                         die(_("grep: failed to create thread: %s"),
 239                             strerror(err));
 240         }
 241 }
 242
 243 static int wait_all(void)
 244 {
 245         int hit = 0;
 246         int i;
 247
 248         grep_lock();
 249         all_work_added = 1;
 250
 251         /* Wait until all work is done. */
 252         while (todo_done != todo_end)
 253                 pthread_cond_wait(&cond_result, &grep_mutex);
 254
 255         /* Wake up all the consumer threads so they can see that there
 256          * is no more work to do.
 257          */
 258         pthread_cond_broadcast(&cond_add);
 259         grep_unlock();
 260
 261         for (i = 0; i < ARRAY_SIZE(threads); i++) {
 262                 void *h;
 263                 pthread_join(threads[i], &h);
 264                 hit |= (int) (intptr_t) h;
 265         }
 266
 267         pthread_mutex_destroy(&grep_mutex);
 268         pthread_mutex_destroy(&grep_read_mutex);
 269         pthread_mutex_destroy(&grep_attr_mutex);
 270         pthread_cond_destroy(&cond_add);
 271         pthread_cond_destroy(&cond_write);
 272         pthread_cond_destroy(&cond_result);
 273         grep_use_locks = 0;
 274
 275         return hit;
 276 }
 277 #else /* !NO_PTHREADS */
 278
 279 static int wait_all(void)
 280 {
 281         return 0;
 282 }
 283 #endif
 284
 285 static int grep_cmd_config(const char *var, const char *value, void *cb)
 286 {
 287         int st = grep_config(var, value, cb);
 288         if (git_color_default_config(var, value, cb) < 0)
 289                 st = -1;
 290         return st;
 291 }
 292
 293 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 294 {
 295         void *data;
 296
 297         grep_read_lock();
 298         data = read_sha1_file(sha1, type, size);
 299         grep_read_unlock();
 300         return data;
 301 }
 302
 303 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 304                      const char *filename, int tree_name_len,
 305                      const char *path)
 306 {
 307         struct strbuf pathbuf = STRBUF_INIT;
 308
 309         if (opt->relative && opt->prefix_length) {
 310                 quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
 311                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 312         } else {
 313                 strbuf_addstr(&pathbuf, filename);
 314         }
 315
 316 #ifndef NO_PTHREADS
 317         if (use_threads) {
 318                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
 319                 strbuf_release(&pathbuf);
 320                 return 0;
 321         } else
 322 #endif
 323         {
 324                 struct grep_source gs;
 325                 int hit;
 326
 327                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
 328                 strbuf_release(&pathbuf);
 329                 hit = grep_source(opt, &gs);
 330
 331                 grep_source_clear(&gs);
 332                 return hit;
 333         }
 334 }
 335
 336 static int grep_file(struct grep_opt *opt, const char *filename)
 337 {
 338         struct strbuf buf = STRBUF_INIT;
 339
 340         if (opt->relative && opt->prefix_length)
 341                 quote_path_relative(filename, opt->prefix, &buf);
 342         else
 343                 strbuf_addstr(&buf, filename);
 344
 345 #ifndef NO_PTHREADS
 346         if (use_threads) {
 347                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename, filename);
 348                 strbuf_release(&buf);
 349                 return 0;
 350         } else
 351 #endif
 352         {
 353                 struct grep_source gs;
 354                 int hit;
 355
 356                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
 357                 strbuf_release(&buf);
 358                 hit = grep_source(opt, &gs);
 359
 360                 grep_source_clear(&gs);
 361                 return hit;
 362         }
 363 }
 364
 365 static void append_path(struct grep_opt *opt, const void *data, size_t len)
 366 {
 367         struct string_list *path_list = opt->output_priv;
 368
 369         if (len == 1 && *(const char *)data == '\0')
 370                 return;
 371         string_list_append(path_list, xstrndup(data, len));
 372 }
 373
 374 static void run_pager(struct grep_opt *opt, const char *prefix)
 375 {
 376         struct string_list *path_list = opt->output_priv;
 377         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 378         int i, status;
 379
 380         for (i = 0; i < path_list->nr; i++)
 381                 argv[i] = path_list->items[i].string;
 382         argv[path_list->nr] = NULL;
 383
 384         if (prefix && chdir(prefix))
 385                 die(_("Failed to chdir: %s"), prefix);
 386         status = run_command_v_opt(argv, RUN_USING_SHELL);
 387         if (status)
 388                 exit(status);
 389         free(argv);
 390 }
 391
 392 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 393 {
 394         int hit = 0;
 395         int nr;
 396         read_cache();
 397
 398         for (nr = 0; nr < active_nr; nr++) {
 399                 const struct cache_entry *ce = active_cache[nr];
 400                 if (!S_ISREG(ce->ce_mode))
 401                         continue;
 402                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 403                         continue;
 404                 if (skip_binary(opt, ce->name))
 405                         continue;
 406
 407                 /*
 408                  * If CE_VALID is on, we assume worktree file and its cache entry
 409                  * are identical, even if worktree file has been modified, so use
 410                  * cache version instead
 411                  */
 412                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 413                         if (ce_stage(ce))
 414                                 continue;
 415                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0, ce->name);
 416                 }
 417                 else
 418                         hit |= grep_file(opt, ce->name);
 419                 if (ce_stage(ce)) {
 420                         do {
 421                                 nr++;
 422                         } while (nr < active_nr &&
 423                                  !strcmp(ce->name, active_cache[nr]->name));
 424                         nr--; /* compensate for loop control */
 425                 }
 426                 if (hit && opt->status_only)
 427                         break;
 428         }
 429         return hit;
 430 }
 431
 432 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 433                      struct tree_desc *tree, struct strbuf *base, int tn_len,
 434                      int check_attr)
 435 {
 436         int hit = 0;
 437         enum interesting match = entry_not_interesting;
 438         struct name_entry entry;
 439         int old_baselen = base->len;
 440
 441         while (tree_entry(tree, &entry)) {
 442                 int te_len = tree_entry_len(&entry);
 443
 444                 if (match != all_entries_interesting) {
 445                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 446                         if (match == all_entries_not_interesting)
 447                                 break;
 448                         if (match == entry_not_interesting)
 449                                 continue;
 450                 }
 451
 452                 strbuf_add(base, entry.path, te_len);
 453
 454                 if (S_ISREG(entry.mode)) {
 455                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len,
 456                                          check_attr ? base->buf + tn_len : NULL);
 457                 }
 458                 else if (S_ISDIR(entry.mode)) {
 459                         enum object_type type;
 460                         struct tree_desc sub;
 461                         void *data;
 462                         unsigned long size;
 463
 464                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 465                         if (!data)
 466                                 die(_("unable to read tree (%s)"),
 467                                     sha1_to_hex(entry.sha1));
 468
 469                         strbuf_addch(base, '/');
 470                         init_tree_desc(&sub, data, size);
 471                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
 472                                          check_attr);
 473                         free(data);
 474                 }
 475                 strbuf_setlen(base, old_baselen);
 476
 477                 if (hit && opt->status_only)
 478                         break;
 479         }
 480         return hit;
 481 }
 482
 483 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 484                        struct object *obj, const char *name, struct object_context *oc)
 485 {
 486         if (obj->type == OBJ_BLOB)
 487                 return grep_sha1(opt, obj->sha1, name, 0, oc ? oc->path : NULL);
 488         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 489                 struct tree_desc tree;
 490                 void *data;
 491                 unsigned long size;
 492                 struct strbuf base;
 493                 int hit, len;
 494
 495                 grep_read_lock();
 496                 data = read_object_with_reference(obj->sha1, tree_type,
 497                                                   &size, NULL);
 498                 grep_read_unlock();
 499
 500                 if (!data)
 501                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 502
 503                 len = name ? strlen(name) : 0;
 504                 strbuf_init(&base, PATH_MAX + len + 1);
 505                 if (len) {
 506                         strbuf_add(&base, name, len);
 507                         strbuf_addch(&base, ':');
 508                 }
 509                 init_tree_desc(&tree, data, size);
 510                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
 511                                 obj->type == OBJ_COMMIT);
 512                 strbuf_release(&base);
 513                 free(data);
 514                 return hit;
 515         }
 516         die(_("unable to grep from object of type %s"), typename(obj->type));
 517 }
 518
 519 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 520                         const struct object_array *list)
 521 {
 522         unsigned int i;
 523         int hit = 0;
 524         const unsigned int nr = list->nr;
 525
 526         for (i = 0; i < nr; i++) {
 527                 struct object *real_obj;
 528                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
 529                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name, list->objects[i].context)) {
 530                         hit = 1;
 531                         if (opt->status_only)
 532                                 break;
 533                 }
 534         }
 535         return hit;
 536 }
 537
 538 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 539                           int exc_std)
 540 {
 541         struct dir_struct dir;
 542         int i, hit = 0;
 543
 544         memset(&dir, 0, sizeof(dir));
 545         if (exc_std)
 546                 setup_standard_excludes(&dir);
 547
 548         fill_directory(&dir, pathspec);
 549         for (i = 0; i < dir.nr; i++) {
 550                 const char *name = dir.entries[i]->name;
 551                 int namelen = strlen(name);
 552                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 553                         continue;
 554                 hit |= grep_file(opt, dir.entries[i]->name);
 555                 if (hit && opt->status_only)
 556                         break;
 557         }
 558         return hit;
 559 }
 560
 561 static int context_callback(const struct option *opt, const char *arg,
 562                             int unset)
 563 {
 564         struct grep_opt *grep_opt = opt->value;
 565         int value;
 566         const char *endp;
 567
 568         if (unset) {
 569                 grep_opt->pre_context = grep_opt->post_context = 0;
 570                 return 0;
 571         }
 572         value = strtol(arg, (char **)&endp, 10);
 573         if (*endp) {
 574                 return error(_("switch `%c' expects a numerical value"),
 575                              opt->short_name);
 576         }
 577         grep_opt->pre_context = grep_opt->post_context = value;
 578         return 0;
 579 }
 580
 581 static int file_callback(const struct option *opt, const char *arg, int unset)
 582 {
 583         struct grep_opt *grep_opt = opt->value;
 584         int from_stdin = !strcmp(arg, "-");
 585         FILE *patterns;
 586         int lno = 0;
 587         struct strbuf sb = STRBUF_INIT;
 588
 589         patterns = from_stdin ? stdin : fopen(arg, "r");
 590         if (!patterns)
 591                 die_errno(_("cannot open '%s'"), arg);
 592         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 593                 /* ignore empty line like grep does */
 594                 if (sb.len == 0)
 595                         continue;
 596
 597                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 598                                 GREP_PATTERN);
 599         }
 600         if (!from_stdin)
 601                 fclose(patterns);
 602         strbuf_release(&sb);
 603         return 0;
 604 }
 605
 606 static int not_callback(const struct option *opt, const char *arg, int unset)
 607 {
 608         struct grep_opt *grep_opt = opt->value;
 609         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 610         return 0;
 611 }
 612
 613 static int and_callback(const struct option *opt, const char *arg, int unset)
 614 {
 615         struct grep_opt *grep_opt = opt->value;
 616         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 617         return 0;
 618 }
 619
 620 static int open_callback(const struct option *opt, const char *arg, int unset)
 621 {
 622         struct grep_opt *grep_opt = opt->value;
 623         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 624         return 0;
 625 }
 626
 627 static int close_callback(const struct option *opt, const char *arg, int unset)
 628 {
 629         struct grep_opt *grep_opt = opt->value;
 630         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 631         return 0;
 632 }
 633
 634 static int pattern_callback(const struct option *opt, const char *arg,
 635                             int unset)
 636 {
 637         struct grep_opt *grep_opt = opt->value;
 638         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 639         return 0;
 640 }
 641
 642 static int help_callback(const struct option *opt, const char *arg, int unset)
 643 {
 644         return -1;
 645 }
 646
 647 int cmd_grep(int argc, const char **argv, const char *prefix)
 648 {
 649         int hit = 0;
 650         int cached = 0, untracked = 0, opt_exclude = -1;
 651         int seen_dashdash = 0;
 652         int external_grep_allowed__ignored;
 653         const char *show_in_pager = NULL, *default_pager = "dummy";
 654         struct grep_opt opt;
 655         struct object_array list = OBJECT_ARRAY_INIT;
 656         struct pathspec pathspec;
 657         struct string_list path_list = STRING_LIST_INIT_NODUP;
 658         int i;
 659         int dummy;
 660         int use_index = 1;
 661         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 662
 663         struct option options[] = {
 664                 OPT_BOOL(0, "cached", &cached,
 665                         N_("search in index instead of in the work tree")),
 666                 OPT_NEGBIT(0, "no-index", &use_index,
 667                          N_("find in contents not managed by git"), 1),
 668                 OPT_BOOL(0, "untracked", &untracked,
 669                         N_("search in both tracked and untracked files")),
 670                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 671                             N_("search also in ignored files"), 1),
 672                 OPT_GROUP(""),
 673                 OPT_BOOL('v', "invert-match", &opt.invert,
 674                         N_("show non-matching lines")),
 675                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
 676                         N_("case insensitive matching")),
 677                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
 678                         N_("match patterns only at word boundaries")),
 679                 OPT_SET_INT('a', "text", &opt.binary,
 680                         N_("process binary files as text"), GREP_BINARY_TEXT),
 681                 OPT_SET_INT('I', NULL, &opt.binary,
 682                         N_("don't match patterns in binary files"),
 683                         GREP_BINARY_NOMATCH),
 684                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
 685                          N_("process binary files with textconv filters")),
 686                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 687                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 688                         NULL, 1 },
 689                 OPT_GROUP(""),
 690                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 691                             N_("use extended POSIX regular expressions"),
 692                             GREP_PATTERN_TYPE_ERE),
 693                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 694                             N_("use basic POSIX regular expressions (default)"),
 695                             GREP_PATTERN_TYPE_BRE),
 696                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 697                             N_("interpret patterns as fixed strings"),
 698                             GREP_PATTERN_TYPE_FIXED),
 699                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 700                             N_("use Perl-compatible regular expressions"),
 701                             GREP_PATTERN_TYPE_PCRE),
 702                 OPT_GROUP(""),
 703                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
 704                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 705                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 706                 OPT_NEGBIT(0, "full-name", &opt.relative,
 707                         N_("show filenames relative to top directory"), 1),
 708                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
 709                         N_("show only filenames instead of matching lines")),
 710                 OPT_BOOL(0, "name-only", &opt.name_only,
 711                         N_("synonym for --files-with-matches")),
 712                 OPT_BOOL('L', "files-without-match",
 713                         &opt.unmatch_name_only,
 714                         N_("show only the names of files without match")),
 715                 OPT_BOOL('z', "null", &opt.null_following_name,
 716                         N_("print NUL after filenames")),
 717                 OPT_BOOL('c', "count", &opt.count,
 718                         N_("show the number of matches instead of matching lines")),
 719                 OPT__COLOR(&opt.color, N_("highlight matches")),
 720                 OPT_BOOL(0, "break", &opt.file_break,
 721                         N_("print empty line between matches from different files")),
 722                 OPT_BOOL(0, "heading", &opt.heading,
 723                         N_("show filename only once above matches from same file")),
 724                 OPT_GROUP(""),
 725                 OPT_CALLBACK('C', "context", &opt, N_("n"),
 726                         N_("show <n> context lines before and after matches"),
 727                         context_callback),
 728                 OPT_INTEGER('B', "before-context", &opt.pre_context,
 729                         N_("show <n> context lines before matches")),
 730                 OPT_INTEGER('A', "after-context", &opt.post_context,
 731                         N_("show <n> context lines after matches")),
 732                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 733                         context_callback),
 734                 OPT_BOOL('p', "show-function", &opt.funcname,
 735                         N_("show a line with the function name before matches")),
 736                 OPT_BOOL('W', "function-context", &opt.funcbody,
 737                         N_("show the surrounding function")),
 738                 OPT_GROUP(""),
 739                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
 740                         N_("read patterns from file"), file_callback),
 741                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 742                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 743                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 744                   N_("combine patterns specified with -e"),
 745                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 746                 OPT_BOOL(0, "or", &dummy, ""),
 747                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 748                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 749                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 750                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 751                   open_callback },
 752                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 753                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 754                   close_callback },
 755                 OPT__QUIET(&opt.status_only,
 756                            N_("indicate hit with exit status without output")),
 757                 OPT_BOOL(0, "all-match", &opt.all_match,
 758                         N_("show only matches from files that match all patterns")),
 759                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 760                   N_("show parse tree for grep expression"),
 761                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 762                 OPT_GROUP(""),
 763                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 764                         N_("pager"), N_("show matching files in the pager"),
 765                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 766                 OPT_BOOL(0, "ext-grep", &external_grep_allowed__ignored,
 767                          N_("allow calling of grep(1) (ignored by this build)")),
 768                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, N_("show usage"),
 769                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 770                 OPT_END()
 771         };
 772
 773         /*
 774          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 775          * to show usage information and exit.
 776          */
 777         if (argc == 2 && !strcmp(argv[1], "-h"))
 778                 usage_with_options(grep_usage, options);
 779
 780         init_grep_defaults();
 781         git_config(grep_cmd_config, NULL);
 782         grep_init(&opt, prefix);
 783
 784         /*
 785          * If there is no -- then the paths must exist in the working
 786          * tree.  If there is no explicit pattern specified with -e or
 787          * -f, we take the first unrecognized non option to be the
 788          * pattern, but then what follows it must be zero or more
 789          * valid refs up to the -- (if exists), and then existing
 790          * paths.  If there is an explicit pattern, then the first
 791          * unrecognized non option is the beginning of the refs list
 792          * that continues up to the -- (if exists), and then paths.
 793          */
 794         argc = parse_options(argc, argv, prefix, options, grep_usage,
 795                              PARSE_OPT_KEEP_DASHDASH |
 796                              PARSE_OPT_STOP_AT_NON_OPTION |
 797                              PARSE_OPT_NO_INTERNAL_HELP);
 798         grep_commit_pattern_type(pattern_type_arg, &opt);
 799
 800         if (use_index && !startup_info->have_repository)
 801                 /* die the same way as if we did it at the beginning */
 802                 setup_git_directory();
 803
 804         /*
 805          * skip a -- separator; we know it cannot be
 806          * separating revisions from pathnames if
 807          * we haven't even had any patterns yet
 808          */
 809         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 810                 argv++;
 811                 argc--;
 812         }
 813
 814         /* First unrecognized non-option token */
 815         if (argc > 0 && !opt.pattern_list) {
 816                 append_grep_pattern(&opt, argv[0], "command line", 0,
 817                                     GREP_PATTERN);
 818                 argv++;
 819                 argc--;
 820         }
 821
 822         if (show_in_pager == default_pager)
 823                 show_in_pager = git_pager(1);
 824         if (show_in_pager) {
 825                 opt.color = 0;
 826                 opt.name_only = 1;
 827                 opt.null_following_name = 1;
 828                 opt.output_priv = &path_list;
 829                 opt.output = append_path;
 830                 string_list_append(&path_list, show_in_pager);
 831                 use_threads = 0;
 832         }
 833         if ((opt.binary & GREP_BINARY_NOMATCH))
 834                 use_threads = 0;
 835
 836         if (!opt.pattern_list)
 837                 die(_("no pattern given."));
 838         if (!opt.fixed && opt.ignore_case)
 839                 opt.regflags |= REG_ICASE;
 840
 841         compile_grep_patterns(&opt);
 842
 843         /* Check revs and then paths */
 844         for (i = 0; i < argc; i++) {
 845                 const char *arg = argv[i];
 846                 unsigned char sha1[20];
 847                 struct object_context oc;
 848                 /* Is it a rev? */
 849                 if (!get_sha1_with_context(arg, 0, sha1, &oc)) {
 850                         struct object *object = parse_object_or_die(sha1, arg);
 851                         if (!seen_dashdash)
 852                                 verify_non_filename(prefix, arg);
 853                         add_object_array_with_context(object, arg, &list, xmemdupz(&oc, sizeof(struct object_context)));
 854                         continue;
 855                 }
 856                 if (!strcmp(arg, "--")) {
 857                         i++;
 858                         seen_dashdash = 1;
 859                 }
 860                 break;
 861         }
 862
 863 #ifndef NO_PTHREADS
 864         if (list.nr || cached || online_cpus() == 1)
 865                 use_threads = 0;
 866 #else
 867         use_threads = 0;
 868 #endif
 869
 870 #ifndef NO_PTHREADS
 871         if (use_threads) {
 872                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 873                     && (opt.pre_context || opt.post_context ||
 874                         opt.file_break || opt.funcbody))
 875                         skip_first_line = 1;
 876                 start_threads(&opt);
 877         }
 878 #endif
 879
 880         /* The rest are paths */
 881         if (!seen_dashdash) {
 882                 int j;
 883                 for (j = i; j < argc; j++)
 884                         verify_filename(prefix, argv[j], j == i);
 885         }
 886
 887         parse_pathspec(&pathspec, 0,
 888                        PATHSPEC_PREFER_CWD |
 889                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
 890                        prefix, argv + i);
 891         pathspec.max_depth = opt.max_depth;
 892         pathspec.recursive = 1;
 893
 894         if (show_in_pager && (cached || list.nr))
 895                 die(_("--open-files-in-pager only works on the worktree"));
 896
 897         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 898                 const char *pager = path_list.items[0].string;
 899                 int len = strlen(pager);
 900
 901                 if (len > 4 && is_dir_sep(pager[len - 5]))
 902                         pager += len - 4;
 903
 904                 if (opt.ignore_case && !strcmp("less", pager))
 905                         string_list_append(&path_list, "-i");
 906
 907                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 908                         struct strbuf buf = STRBUF_INIT;
 909                         strbuf_addf(&buf, "+/%s%s",
 910                                         strcmp("less", pager) ? "" : "*",
 911                                         opt.pattern_list->pattern);
 912                         string_list_append(&path_list, buf.buf);
 913                         strbuf_detach(&buf, NULL);
 914                 }
 915         }
 916
 917         if (!show_in_pager)
 918                 setup_pager();
 919
 920         if (!use_index && (untracked || cached))
 921                 die(_("--cached or --untracked cannot be used with --no-index."));
 922
 923         if (!use_index || untracked) {
 924                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 925                 if (list.nr)
 926                         die(_("--no-index or --untracked cannot be used with revs."));
 927                 hit = grep_directory(&opt, &pathspec, use_exclude);
 928         } else if (0 <= opt_exclude) {
 929                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 930         } else if (!list.nr) {
 931                 if (!cached)
 932                         setup_work_tree();
 933
 934                 hit = grep_cache(&opt, &pathspec, cached);
 935         } else {
 936                 if (cached)
 937                         die(_("both --cached and trees are given."));
 938                 hit = grep_objects(&opt, &pathspec, &list);
 939         }
 940
 941         if (use_threads)
 942                 hit |= wait_all();
 943         if (hit && show_in_pager)
 944                 run_pager(&opt, prefix);
 945         free_grep_patterns(&opt);
 946         return !hit;
 947 }