grep: move grep_source_init outside critical section
[git] / builtin / grep.c
1 /*
2  * Builtin "git grep"
3  *
4  * Copyright (c) 2006 Junio C Hamano
5  */
6 #include "cache.h"
7 #include "repository.h"
8 #include "config.h"
9 #include "blob.h"
10 #include "tree.h"
11 #include "commit.h"
12 #include "tag.h"
13 #include "tree-walk.h"
14 #include "builtin.h"
15 #include "parse-options.h"
16 #include "string-list.h"
17 #include "run-command.h"
18 #include "userdiff.h"
19 #include "grep.h"
20 #include "quote.h"
21 #include "dir.h"
22 #include "pathspec.h"
23 #include "submodule.h"
24 #include "submodule-config.h"
25
26 static char const * const grep_usage[] = {
27         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
28         NULL
29 };
30
31 static int recurse_submodules;
32
33 #define GREP_NUM_THREADS_DEFAULT 8
34 static int num_threads;
35
36 #ifndef NO_PTHREADS
37 static pthread_t *threads;
38
39 /* We use one producer thread and THREADS consumer
40  * threads. The producer adds struct work_items to 'todo' and the
41  * consumers pick work items from the same array.
42  */
43 struct work_item {
44         struct grep_source source;
45         char done;
46         struct strbuf out;
47 };
48
49 /* In the range [todo_done, todo_start) in 'todo' we have work_items
50  * that have been or are processed by a consumer thread. We haven't
51  * written the result for these to stdout yet.
52  *
53  * The work_items in [todo_start, todo_end) are waiting to be picked
54  * up by a consumer thread.
55  *
56  * The ranges are modulo TODO_SIZE.
57  */
58 #define TODO_SIZE 128
59 static struct work_item todo[TODO_SIZE];
60 static int todo_start;
61 static int todo_end;
62 static int todo_done;
63
64 /* Has all work items been added? */
65 static int all_work_added;
66
67 /* This lock protects all the variables above. */
68 static pthread_mutex_t grep_mutex;
69
70 static inline void grep_lock(void)
71 {
72         assert(num_threads);
73         pthread_mutex_lock(&grep_mutex);
74 }
75
76 static inline void grep_unlock(void)
77 {
78         assert(num_threads);
79         pthread_mutex_unlock(&grep_mutex);
80 }
81
82 /* Signalled when a new work_item is added to todo. */
83 static pthread_cond_t cond_add;
84
85 /* Signalled when the result from one work_item is written to
86  * stdout.
87  */
88 static pthread_cond_t cond_write;
89
90 /* Signalled when we are finished with everything. */
91 static pthread_cond_t cond_result;
92
93 static int skip_first_line;
94
95 static void add_work(struct grep_opt *opt, const struct grep_source *gs)
96 {
97         grep_lock();
98
99         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
100                 pthread_cond_wait(&cond_write, &grep_mutex);
101         }
102
103         todo[todo_end].source = *gs;
104         if (opt->binary != GREP_BINARY_TEXT)
105                 grep_source_load_driver(&todo[todo_end].source);
106         todo[todo_end].done = 0;
107         strbuf_reset(&todo[todo_end].out);
108         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
109
110         pthread_cond_signal(&cond_add);
111         grep_unlock();
112 }
113
114 static struct work_item *get_work(void)
115 {
116         struct work_item *ret;
117
118         grep_lock();
119         while (todo_start == todo_end && !all_work_added) {
120                 pthread_cond_wait(&cond_add, &grep_mutex);
121         }
122
123         if (todo_start == todo_end && all_work_added) {
124                 ret = NULL;
125         } else {
126                 ret = &todo[todo_start];
127                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
128         }
129         grep_unlock();
130         return ret;
131 }
132
133 static void work_done(struct work_item *w)
134 {
135         int old_done;
136
137         grep_lock();
138         w->done = 1;
139         old_done = todo_done;
140         for(; todo[todo_done].done && todo_done != todo_start;
141             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
142                 w = &todo[todo_done];
143                 if (w->out.len) {
144                         const char *p = w->out.buf;
145                         size_t len = w->out.len;
146
147                         /* Skip the leading hunk mark of the first file. */
148                         if (skip_first_line) {
149                                 while (len) {
150                                         len--;
151                                         if (*p++ == '\n')
152                                                 break;
153                                 }
154                                 skip_first_line = 0;
155                         }
156
157                         write_or_die(1, p, len);
158                 }
159                 grep_source_clear(&w->source);
160         }
161
162         if (old_done != todo_done)
163                 pthread_cond_signal(&cond_write);
164
165         if (all_work_added && todo_done == todo_end)
166                 pthread_cond_signal(&cond_result);
167
168         grep_unlock();
169 }
170
171 static void *run(void *arg)
172 {
173         int hit = 0;
174         struct grep_opt *opt = arg;
175
176         while (1) {
177                 struct work_item *w = get_work();
178                 if (!w)
179                         break;
180
181                 opt->output_priv = w;
182                 hit |= grep_source(opt, &w->source);
183                 grep_source_clear_data(&w->source);
184                 work_done(w);
185         }
186         free_grep_patterns(arg);
187         free(arg);
188
189         return (void*) (intptr_t) hit;
190 }
191
192 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
193 {
194         struct work_item *w = opt->output_priv;
195         strbuf_add(&w->out, buf, size);
196 }
197
198 static void start_threads(struct grep_opt *opt)
199 {
200         int i;
201
202         pthread_mutex_init(&grep_mutex, NULL);
203         pthread_mutex_init(&grep_read_mutex, NULL);
204         pthread_mutex_init(&grep_attr_mutex, NULL);
205         pthread_cond_init(&cond_add, NULL);
206         pthread_cond_init(&cond_write, NULL);
207         pthread_cond_init(&cond_result, NULL);
208         grep_use_locks = 1;
209
210         for (i = 0; i < ARRAY_SIZE(todo); i++) {
211                 strbuf_init(&todo[i].out, 0);
212         }
213
214         threads = xcalloc(num_threads, sizeof(*threads));
215         for (i = 0; i < num_threads; i++) {
216                 int err;
217                 struct grep_opt *o = grep_opt_dup(opt);
218                 o->output = strbuf_out;
219                 if (i)
220                         o->debug = 0;
221                 compile_grep_patterns(o);
222                 err = pthread_create(&threads[i], NULL, run, o);
223
224                 if (err)
225                         die(_("grep: failed to create thread: %s"),
226                             strerror(err));
227         }
228 }
229
230 static int wait_all(void)
231 {
232         int hit = 0;
233         int i;
234
235         grep_lock();
236         all_work_added = 1;
237
238         /* Wait until all work is done. */
239         while (todo_done != todo_end)
240                 pthread_cond_wait(&cond_result, &grep_mutex);
241
242         /* Wake up all the consumer threads so they can see that there
243          * is no more work to do.
244          */
245         pthread_cond_broadcast(&cond_add);
246         grep_unlock();
247
248         for (i = 0; i < num_threads; i++) {
249                 void *h;
250                 pthread_join(threads[i], &h);
251                 hit |= (int) (intptr_t) h;
252         }
253
254         free(threads);
255
256         pthread_mutex_destroy(&grep_mutex);
257         pthread_mutex_destroy(&grep_read_mutex);
258         pthread_mutex_destroy(&grep_attr_mutex);
259         pthread_cond_destroy(&cond_add);
260         pthread_cond_destroy(&cond_write);
261         pthread_cond_destroy(&cond_result);
262         grep_use_locks = 0;
263
264         return hit;
265 }
266 #else /* !NO_PTHREADS */
267
268 static int wait_all(void)
269 {
270         return 0;
271 }
272 #endif
273
274 static int grep_cmd_config(const char *var, const char *value, void *cb)
275 {
276         int st = grep_config(var, value, cb);
277         if (git_color_default_config(var, value, cb) < 0)
278                 st = -1;
279
280         if (!strcmp(var, "grep.threads")) {
281                 num_threads = git_config_int(var, value);
282                 if (num_threads < 0)
283                         die(_("invalid number of threads specified (%d) for %s"),
284                             num_threads, var);
285 #ifdef NO_PTHREADS
286                 else if (num_threads && num_threads != 1) {
287                         /*
288                          * TRANSLATORS: %s is the configuration
289                          * variable for tweaking threads, currently
290                          * grep.threads
291                          */
292                         warning(_("no threads support, ignoring %s"), var);
293                         num_threads = 0;
294                 }
295 #endif
296         }
297
298         if (!strcmp(var, "submodule.recurse"))
299                 recurse_submodules = git_config_bool(var, value);
300
301         return st;
302 }
303
304 static void *lock_and_read_oid_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
305 {
306         void *data;
307
308         grep_read_lock();
309         data = read_sha1_file(oid->hash, type, size);
310         grep_read_unlock();
311         return data;
312 }
313
314 static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
315                      const char *filename, int tree_name_len,
316                      const char *path)
317 {
318         struct strbuf pathbuf = STRBUF_INIT;
319         struct grep_source gs;
320
321         if (opt->relative && opt->prefix_length) {
322                 quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
323                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
324         } else {
325                 strbuf_addstr(&pathbuf, filename);
326         }
327
328         grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
329
330 #ifndef NO_PTHREADS
331         if (num_threads) {
332                 /*
333                  * add_work() copies gs and thus assumes ownership of
334                  * its fields, so do not call grep_source_clear()
335                  */
336                 add_work(opt, &gs);
337                 strbuf_release(&pathbuf);
338                 return 0;
339         } else
340 #endif
341         {
342                 int hit;
343
344                 strbuf_release(&pathbuf);
345                 hit = grep_source(opt, &gs);
346
347                 grep_source_clear(&gs);
348                 return hit;
349         }
350 }
351
352 static int grep_file(struct grep_opt *opt, const char *filename)
353 {
354         struct strbuf buf = STRBUF_INIT;
355         struct grep_source gs;
356
357         if (opt->relative && opt->prefix_length)
358                 quote_path_relative(filename, opt->prefix, &buf);
359         else
360                 strbuf_addstr(&buf, filename);
361
362         grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
363
364 #ifndef NO_PTHREADS
365         if (num_threads) {
366                 /*
367                  * add_work() copies gs and thus assumes ownership of
368                  * its fields, so do not call grep_source_clear()
369                  */
370                 add_work(opt, &gs);
371                 strbuf_release(&buf);
372                 return 0;
373         } else
374 #endif
375         {
376                 int hit;
377
378                 strbuf_release(&buf);
379                 hit = grep_source(opt, &gs);
380
381                 grep_source_clear(&gs);
382                 return hit;
383         }
384 }
385
386 static void append_path(struct grep_opt *opt, const void *data, size_t len)
387 {
388         struct string_list *path_list = opt->output_priv;
389
390         if (len == 1 && *(const char *)data == '\0')
391                 return;
392         string_list_append(path_list, xstrndup(data, len));
393 }
394
395 static void run_pager(struct grep_opt *opt, const char *prefix)
396 {
397         struct string_list *path_list = opt->output_priv;
398         struct child_process child = CHILD_PROCESS_INIT;
399         int i, status;
400
401         for (i = 0; i < path_list->nr; i++)
402                 argv_array_push(&child.args, path_list->items[i].string);
403         child.dir = prefix;
404         child.use_shell = 1;
405
406         status = run_command(&child);
407         if (status)
408                 exit(status);
409 }
410
411 static int grep_cache(struct grep_opt *opt, struct repository *repo,
412                       const struct pathspec *pathspec, int cached);
413 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
414                      struct tree_desc *tree, struct strbuf *base, int tn_len,
415                      int check_attr, struct repository *repo);
416
417 static int grep_submodule(struct grep_opt *opt, struct repository *superproject,
418                           const struct pathspec *pathspec,
419                           const struct object_id *oid,
420                           const char *filename, const char *path)
421 {
422         struct repository submodule;
423         int hit;
424
425         if (!is_submodule_active(superproject, path))
426                 return 0;
427
428         if (repo_submodule_init(&submodule, superproject, path))
429                 return 0;
430
431         repo_read_gitmodules(&submodule);
432
433         /*
434          * NEEDSWORK: This adds the submodule's object directory to the list of
435          * alternates for the single in-memory object store.  This has some bad
436          * consequences for memory (processed objects will never be freed) and
437          * performance (this increases the number of pack files git has to pay
438          * attention to, to the sum of the number of pack files in all the
439          * repositories processed so far).  This can be removed once the object
440          * store is no longer global and instead is a member of the repository
441          * object.
442          */
443         grep_read_lock();
444         add_to_alternates_memory(submodule.objectdir);
445         grep_read_unlock();
446
447         if (oid) {
448                 struct object *object;
449                 struct tree_desc tree;
450                 void *data;
451                 unsigned long size;
452                 struct strbuf base = STRBUF_INIT;
453
454                 object = parse_object_or_die(oid, oid_to_hex(oid));
455
456                 grep_read_lock();
457                 data = read_object_with_reference(object->oid.hash, tree_type,
458                                                   &size, NULL);
459                 grep_read_unlock();
460
461                 if (!data)
462                         die(_("unable to read tree (%s)"), oid_to_hex(&object->oid));
463
464                 strbuf_addstr(&base, filename);
465                 strbuf_addch(&base, '/');
466
467                 init_tree_desc(&tree, data, size);
468                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
469                                 object->type == OBJ_COMMIT, &submodule);
470                 strbuf_release(&base);
471                 free(data);
472         } else {
473                 hit = grep_cache(opt, &submodule, pathspec, 1);
474         }
475
476         repo_clear(&submodule);
477         return hit;
478 }
479
480 static int grep_cache(struct grep_opt *opt, struct repository *repo,
481                       const struct pathspec *pathspec, int cached)
482 {
483         int hit = 0;
484         int nr;
485         struct strbuf name = STRBUF_INIT;
486         int name_base_len = 0;
487         if (repo->submodule_prefix) {
488                 name_base_len = strlen(repo->submodule_prefix);
489                 strbuf_addstr(&name, repo->submodule_prefix);
490         }
491
492         repo_read_index(repo);
493
494         for (nr = 0; nr < repo->index->cache_nr; nr++) {
495                 const struct cache_entry *ce = repo->index->cache[nr];
496                 strbuf_setlen(&name, name_base_len);
497                 strbuf_addstr(&name, ce->name);
498
499                 if (S_ISREG(ce->ce_mode) &&
500                     match_pathspec(pathspec, name.buf, name.len, 0, NULL,
501                                    S_ISDIR(ce->ce_mode) ||
502                                    S_ISGITLINK(ce->ce_mode))) {
503                         /*
504                          * If CE_VALID is on, we assume worktree file and its
505                          * cache entry are identical, even if worktree file has
506                          * been modified, so use cache version instead
507                          */
508                         if (cached || (ce->ce_flags & CE_VALID) ||
509                             ce_skip_worktree(ce)) {
510                                 if (ce_stage(ce) || ce_intent_to_add(ce))
511                                         continue;
512                                 hit |= grep_oid(opt, &ce->oid, name.buf,
513                                                  0, name.buf);
514                         } else {
515                                 hit |= grep_file(opt, name.buf);
516                         }
517                 } else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
518                            submodule_path_match(pathspec, name.buf, NULL)) {
519                         hit |= grep_submodule(opt, repo, pathspec, NULL, ce->name, ce->name);
520                 } else {
521                         continue;
522                 }
523
524                 if (ce_stage(ce)) {
525                         do {
526                                 nr++;
527                         } while (nr < repo->index->cache_nr &&
528                                  !strcmp(ce->name, repo->index->cache[nr]->name));
529                         nr--; /* compensate for loop control */
530                 }
531                 if (hit && opt->status_only)
532                         break;
533         }
534
535         strbuf_release(&name);
536         return hit;
537 }
538
539 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
540                      struct tree_desc *tree, struct strbuf *base, int tn_len,
541                      int check_attr, struct repository *repo)
542 {
543         int hit = 0;
544         enum interesting match = entry_not_interesting;
545         struct name_entry entry;
546         int old_baselen = base->len;
547         struct strbuf name = STRBUF_INIT;
548         int name_base_len = 0;
549         if (repo->submodule_prefix) {
550                 strbuf_addstr(&name, repo->submodule_prefix);
551                 name_base_len = name.len;
552         }
553
554         while (tree_entry(tree, &entry)) {
555                 int te_len = tree_entry_len(&entry);
556
557                 if (match != all_entries_interesting) {
558                         strbuf_addstr(&name, base->buf + tn_len);
559                         match = tree_entry_interesting(&entry, &name,
560                                                        0, pathspec);
561                         strbuf_setlen(&name, name_base_len);
562
563                         if (match == all_entries_not_interesting)
564                                 break;
565                         if (match == entry_not_interesting)
566                                 continue;
567                 }
568
569                 strbuf_add(base, entry.path, te_len);
570
571                 if (S_ISREG(entry.mode)) {
572                         hit |= grep_oid(opt, entry.oid, base->buf, tn_len,
573                                          check_attr ? base->buf + tn_len : NULL);
574                 } else if (S_ISDIR(entry.mode)) {
575                         enum object_type type;
576                         struct tree_desc sub;
577                         void *data;
578                         unsigned long size;
579
580                         data = lock_and_read_oid_file(entry.oid, &type, &size);
581                         if (!data)
582                                 die(_("unable to read tree (%s)"),
583                                     oid_to_hex(entry.oid));
584
585                         strbuf_addch(base, '/');
586                         init_tree_desc(&sub, data, size);
587                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
588                                          check_attr, repo);
589                         free(data);
590                 } else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
591                         hit |= grep_submodule(opt, repo, pathspec, entry.oid,
592                                               base->buf, base->buf + tn_len);
593                 }
594
595                 strbuf_setlen(base, old_baselen);
596
597                 if (hit && opt->status_only)
598                         break;
599         }
600
601         strbuf_release(&name);
602         return hit;
603 }
604
605 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
606                        struct object *obj, const char *name, const char *path,
607                        struct repository *repo)
608 {
609         if (obj->type == OBJ_BLOB)
610                 return grep_oid(opt, &obj->oid, name, 0, path);
611         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
612                 struct tree_desc tree;
613                 void *data;
614                 unsigned long size;
615                 struct strbuf base;
616                 int hit, len;
617
618                 grep_read_lock();
619                 data = read_object_with_reference(obj->oid.hash, tree_type,
620                                                   &size, NULL);
621                 grep_read_unlock();
622
623                 if (!data)
624                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
625
626                 len = name ? strlen(name) : 0;
627                 strbuf_init(&base, PATH_MAX + len + 1);
628                 if (len) {
629                         strbuf_add(&base, name, len);
630                         strbuf_addch(&base, ':');
631                 }
632                 init_tree_desc(&tree, data, size);
633                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
634                                 obj->type == OBJ_COMMIT, repo);
635                 strbuf_release(&base);
636                 free(data);
637                 return hit;
638         }
639         die(_("unable to grep from object of type %s"), typename(obj->type));
640 }
641
642 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
643                         struct repository *repo,
644                         const struct object_array *list)
645 {
646         unsigned int i;
647         int hit = 0;
648         const unsigned int nr = list->nr;
649
650         for (i = 0; i < nr; i++) {
651                 struct object *real_obj;
652                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
653
654                 /* load the gitmodules file for this rev */
655                 if (recurse_submodules) {
656                         submodule_free();
657                         gitmodules_config_oid(&real_obj->oid);
658                 }
659                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name, list->objects[i].path,
660                                 repo)) {
661                         hit = 1;
662                         if (opt->status_only)
663                                 break;
664                 }
665         }
666         return hit;
667 }
668
669 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
670                           int exc_std, int use_index)
671 {
672         struct dir_struct dir;
673         int i, hit = 0;
674
675         memset(&dir, 0, sizeof(dir));
676         if (!use_index)
677                 dir.flags |= DIR_NO_GITLINKS;
678         if (exc_std)
679                 setup_standard_excludes(&dir);
680
681         fill_directory(&dir, &the_index, pathspec);
682         for (i = 0; i < dir.nr; i++) {
683                 if (!dir_path_match(dir.entries[i], pathspec, 0, NULL))
684                         continue;
685                 hit |= grep_file(opt, dir.entries[i]->name);
686                 if (hit && opt->status_only)
687                         break;
688         }
689         return hit;
690 }
691
692 static int context_callback(const struct option *opt, const char *arg,
693                             int unset)
694 {
695         struct grep_opt *grep_opt = opt->value;
696         int value;
697         const char *endp;
698
699         if (unset) {
700                 grep_opt->pre_context = grep_opt->post_context = 0;
701                 return 0;
702         }
703         value = strtol(arg, (char **)&endp, 10);
704         if (*endp) {
705                 return error(_("switch `%c' expects a numerical value"),
706                              opt->short_name);
707         }
708         grep_opt->pre_context = grep_opt->post_context = value;
709         return 0;
710 }
711
712 static int file_callback(const struct option *opt, const char *arg, int unset)
713 {
714         struct grep_opt *grep_opt = opt->value;
715         int from_stdin = !strcmp(arg, "-");
716         FILE *patterns;
717         int lno = 0;
718         struct strbuf sb = STRBUF_INIT;
719
720         patterns = from_stdin ? stdin : fopen(arg, "r");
721         if (!patterns)
722                 die_errno(_("cannot open '%s'"), arg);
723         while (strbuf_getline(&sb, patterns) == 0) {
724                 /* ignore empty line like grep does */
725                 if (sb.len == 0)
726                         continue;
727
728                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
729                                 GREP_PATTERN);
730         }
731         if (!from_stdin)
732                 fclose(patterns);
733         strbuf_release(&sb);
734         return 0;
735 }
736
737 static int not_callback(const struct option *opt, const char *arg, int unset)
738 {
739         struct grep_opt *grep_opt = opt->value;
740         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
741         return 0;
742 }
743
744 static int and_callback(const struct option *opt, const char *arg, int unset)
745 {
746         struct grep_opt *grep_opt = opt->value;
747         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
748         return 0;
749 }
750
751 static int open_callback(const struct option *opt, const char *arg, int unset)
752 {
753         struct grep_opt *grep_opt = opt->value;
754         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
755         return 0;
756 }
757
758 static int close_callback(const struct option *opt, const char *arg, int unset)
759 {
760         struct grep_opt *grep_opt = opt->value;
761         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
762         return 0;
763 }
764
765 static int pattern_callback(const struct option *opt, const char *arg,
766                             int unset)
767 {
768         struct grep_opt *grep_opt = opt->value;
769         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
770         return 0;
771 }
772
773 int cmd_grep(int argc, const char **argv, const char *prefix)
774 {
775         int hit = 0;
776         int cached = 0, untracked = 0, opt_exclude = -1;
777         int seen_dashdash = 0;
778         int external_grep_allowed__ignored;
779         const char *show_in_pager = NULL, *default_pager = "dummy";
780         struct grep_opt opt;
781         struct object_array list = OBJECT_ARRAY_INIT;
782         struct pathspec pathspec;
783         struct string_list path_list = STRING_LIST_INIT_NODUP;
784         int i;
785         int dummy;
786         int use_index = 1;
787         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
788         int allow_revs;
789
790         struct option options[] = {
791                 OPT_BOOL(0, "cached", &cached,
792                         N_("search in index instead of in the work tree")),
793                 OPT_NEGBIT(0, "no-index", &use_index,
794                          N_("find in contents not managed by git"), 1),
795                 OPT_BOOL(0, "untracked", &untracked,
796                         N_("search in both tracked and untracked files")),
797                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
798                             N_("ignore files specified via '.gitignore'"), 1),
799                 OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
800                          N_("recursively search in each submodule")),
801                 OPT_GROUP(""),
802                 OPT_BOOL('v', "invert-match", &opt.invert,
803                         N_("show non-matching lines")),
804                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
805                         N_("case insensitive matching")),
806                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
807                         N_("match patterns only at word boundaries")),
808                 OPT_SET_INT('a', "text", &opt.binary,
809                         N_("process binary files as text"), GREP_BINARY_TEXT),
810                 OPT_SET_INT('I', NULL, &opt.binary,
811                         N_("don't match patterns in binary files"),
812                         GREP_BINARY_NOMATCH),
813                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
814                          N_("process binary files with textconv filters")),
815                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
816                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
817                         NULL, 1 },
818                 OPT_GROUP(""),
819                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
820                             N_("use extended POSIX regular expressions"),
821                             GREP_PATTERN_TYPE_ERE),
822                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
823                             N_("use basic POSIX regular expressions (default)"),
824                             GREP_PATTERN_TYPE_BRE),
825                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
826                             N_("interpret patterns as fixed strings"),
827                             GREP_PATTERN_TYPE_FIXED),
828                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
829                             N_("use Perl-compatible regular expressions"),
830                             GREP_PATTERN_TYPE_PCRE),
831                 OPT_GROUP(""),
832                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
833                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
834                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
835                 OPT_NEGBIT(0, "full-name", &opt.relative,
836                         N_("show filenames relative to top directory"), 1),
837                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
838                         N_("show only filenames instead of matching lines")),
839                 OPT_BOOL(0, "name-only", &opt.name_only,
840                         N_("synonym for --files-with-matches")),
841                 OPT_BOOL('L', "files-without-match",
842                         &opt.unmatch_name_only,
843                         N_("show only the names of files without match")),
844                 OPT_BOOL('z', "null", &opt.null_following_name,
845                         N_("print NUL after filenames")),
846                 OPT_BOOL('c', "count", &opt.count,
847                         N_("show the number of matches instead of matching lines")),
848                 OPT__COLOR(&opt.color, N_("highlight matches")),
849                 OPT_BOOL(0, "break", &opt.file_break,
850                         N_("print empty line between matches from different files")),
851                 OPT_BOOL(0, "heading", &opt.heading,
852                         N_("show filename only once above matches from same file")),
853                 OPT_GROUP(""),
854                 OPT_CALLBACK('C', "context", &opt, N_("n"),
855                         N_("show <n> context lines before and after matches"),
856                         context_callback),
857                 OPT_INTEGER('B', "before-context", &opt.pre_context,
858                         N_("show <n> context lines before matches")),
859                 OPT_INTEGER('A', "after-context", &opt.post_context,
860                         N_("show <n> context lines after matches")),
861                 OPT_INTEGER(0, "threads", &num_threads,
862                         N_("use <n> worker threads")),
863                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
864                         context_callback),
865                 OPT_BOOL('p', "show-function", &opt.funcname,
866                         N_("show a line with the function name before matches")),
867                 OPT_BOOL('W', "function-context", &opt.funcbody,
868                         N_("show the surrounding function")),
869                 OPT_GROUP(""),
870                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
871                         N_("read patterns from file"), file_callback),
872                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
873                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
874                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
875                   N_("combine patterns specified with -e"),
876                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
877                 OPT_BOOL(0, "or", &dummy, ""),
878                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
879                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
880                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
881                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
882                   open_callback },
883                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
884                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
885                   close_callback },
886                 OPT__QUIET(&opt.status_only,
887                            N_("indicate hit with exit status without output")),
888                 OPT_BOOL(0, "all-match", &opt.all_match,
889                         N_("show only matches from files that match all patterns")),
890                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
891                   N_("show parse tree for grep expression"),
892                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
893                 OPT_GROUP(""),
894                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
895                         N_("pager"), N_("show matching files in the pager"),
896                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
897                 OPT_BOOL(0, "ext-grep", &external_grep_allowed__ignored,
898                          N_("allow calling of grep(1) (ignored by this build)")),
899                 OPT_END()
900         };
901
902         init_grep_defaults();
903         git_config(grep_cmd_config, NULL);
904         grep_init(&opt, prefix);
905
906         /*
907          * If there is no -- then the paths must exist in the working
908          * tree.  If there is no explicit pattern specified with -e or
909          * -f, we take the first unrecognized non option to be the
910          * pattern, but then what follows it must be zero or more
911          * valid refs up to the -- (if exists), and then existing
912          * paths.  If there is an explicit pattern, then the first
913          * unrecognized non option is the beginning of the refs list
914          * that continues up to the -- (if exists), and then paths.
915          */
916         argc = parse_options(argc, argv, prefix, options, grep_usage,
917                              PARSE_OPT_KEEP_DASHDASH |
918                              PARSE_OPT_STOP_AT_NON_OPTION);
919         grep_commit_pattern_type(pattern_type_arg, &opt);
920
921         if (use_index && !startup_info->have_repository) {
922                 int fallback = 0;
923                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
924                 if (fallback)
925                         use_index = 0;
926                 else
927                         /* die the same way as if we did it at the beginning */
928                         setup_git_directory();
929         }
930
931         /*
932          * skip a -- separator; we know it cannot be
933          * separating revisions from pathnames if
934          * we haven't even had any patterns yet
935          */
936         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
937                 argv++;
938                 argc--;
939         }
940
941         /* First unrecognized non-option token */
942         if (argc > 0 && !opt.pattern_list) {
943                 append_grep_pattern(&opt, argv[0], "command line", 0,
944                                     GREP_PATTERN);
945                 argv++;
946                 argc--;
947         }
948
949         if (show_in_pager == default_pager)
950                 show_in_pager = git_pager(1);
951         if (show_in_pager) {
952                 opt.color = 0;
953                 opt.name_only = 1;
954                 opt.null_following_name = 1;
955                 opt.output_priv = &path_list;
956                 opt.output = append_path;
957                 string_list_append(&path_list, show_in_pager);
958         }
959
960         if (!opt.pattern_list)
961                 die(_("no pattern given."));
962
963         /*
964          * We have to find "--" in a separate pass, because its presence
965          * influences how we will parse arguments that come before it.
966          */
967         for (i = 0; i < argc; i++) {
968                 if (!strcmp(argv[i], "--")) {
969                         seen_dashdash = 1;
970                         break;
971                 }
972         }
973
974         /*
975          * Resolve any rev arguments. If we have a dashdash, then everything up
976          * to it must resolve as a rev. If not, then we stop at the first
977          * non-rev and assume everything else is a path.
978          */
979         allow_revs = use_index && !untracked;
980         for (i = 0; i < argc; i++) {
981                 const char *arg = argv[i];
982                 struct object_id oid;
983                 struct object_context oc;
984                 struct object *object;
985
986                 if (!strcmp(arg, "--")) {
987                         i++;
988                         break;
989                 }
990
991                 if (!allow_revs) {
992                         if (seen_dashdash)
993                                 die(_("--no-index or --untracked cannot be used with revs"));
994                         break;
995                 }
996
997                 if (get_oid_with_context(arg, GET_OID_RECORD_PATH,
998                                          &oid, &oc)) {
999                         if (seen_dashdash)
1000                                 die(_("unable to resolve revision: %s"), arg);
1001                         break;
1002                 }
1003
1004                 object = parse_object_or_die(&oid, arg);
1005                 if (!seen_dashdash)
1006                         verify_non_filename(prefix, arg);
1007                 add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
1008                 free(oc.path);
1009         }
1010
1011         /*
1012          * Anything left over is presumed to be a path. But in the non-dashdash
1013          * "do what I mean" case, we verify and complain when that isn't true.
1014          */
1015         if (!seen_dashdash) {
1016                 int j;
1017                 for (j = i; j < argc; j++)
1018                         verify_filename(prefix, argv[j], j == i && allow_revs);
1019         }
1020
1021         parse_pathspec(&pathspec, 0,
1022                        PATHSPEC_PREFER_CWD |
1023                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
1024                        prefix, argv + i);
1025         pathspec.max_depth = opt.max_depth;
1026         pathspec.recursive = 1;
1027         pathspec.recurse_submodules = !!recurse_submodules;
1028
1029 #ifndef NO_PTHREADS
1030         if (list.nr || cached || show_in_pager)
1031                 num_threads = 0;
1032         else if (num_threads == 0)
1033                 num_threads = GREP_NUM_THREADS_DEFAULT;
1034         else if (num_threads < 0)
1035                 die(_("invalid number of threads specified (%d)"), num_threads);
1036         if (num_threads == 1)
1037                 num_threads = 0;
1038 #else
1039         if (num_threads)
1040                 warning(_("no threads support, ignoring --threads"));
1041         num_threads = 0;
1042 #endif
1043
1044         if (!num_threads)
1045                 /*
1046                  * The compiled patterns on the main path are only
1047                  * used when not using threading. Otherwise
1048                  * start_threads() below calls compile_grep_patterns()
1049                  * for each thread.
1050                  */
1051                 compile_grep_patterns(&opt);
1052
1053 #ifndef NO_PTHREADS
1054         if (num_threads) {
1055                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
1056                     && (opt.pre_context || opt.post_context ||
1057                         opt.file_break || opt.funcbody))
1058                         skip_first_line = 1;
1059                 start_threads(&opt);
1060         }
1061 #endif
1062
1063         if (show_in_pager && (cached || list.nr))
1064                 die(_("--open-files-in-pager only works on the worktree"));
1065
1066         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
1067                 const char *pager = path_list.items[0].string;
1068                 int len = strlen(pager);
1069
1070                 if (len > 4 && is_dir_sep(pager[len - 5]))
1071                         pager += len - 4;
1072
1073                 if (opt.ignore_case && !strcmp("less", pager))
1074                         string_list_append(&path_list, "-I");
1075
1076                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
1077                         struct strbuf buf = STRBUF_INIT;
1078                         strbuf_addf(&buf, "+/%s%s",
1079                                         strcmp("less", pager) ? "" : "*",
1080                                         opt.pattern_list->pattern);
1081                         string_list_append(&path_list, buf.buf);
1082                         strbuf_detach(&buf, NULL);
1083                 }
1084         }
1085
1086         if (recurse_submodules && (!use_index || untracked))
1087                 die(_("option not supported with --recurse-submodules."));
1088
1089         if (!show_in_pager && !opt.status_only)
1090                 setup_pager();
1091
1092         if (!use_index && (untracked || cached))
1093                 die(_("--cached or --untracked cannot be used with --no-index."));
1094
1095         if (!use_index || untracked) {
1096                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
1097                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
1098         } else if (0 <= opt_exclude) {
1099                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
1100         } else if (!list.nr) {
1101                 if (!cached)
1102                         setup_work_tree();
1103
1104                 hit = grep_cache(&opt, the_repository, &pathspec, cached);
1105         } else {
1106                 if (cached)
1107                         die(_("both --cached and trees are given."));
1108
1109                 hit = grep_objects(&opt, &pathspec, the_repository, &list);
1110         }
1111
1112         if (num_threads)
1113                 hit |= wait_all();
1114         if (hit && show_in_pager)
1115                 run_pager(&opt, prefix);
1116         clear_pathspec(&pathspec);
1117         free_grep_patterns(&opt);
1118         return !hit;
1119 }