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