submodule.c: fetch in submodules git directory instead of in worktree
[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 #include "object-store.h"
26
27 static char const * const grep_usage[] = {
28         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
29         NULL
30 };
31
32 static int recurse_submodules;
33
34 #define GREP_NUM_THREADS_DEFAULT 8
35 static int num_threads;
36
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         pthread_mutex_lock(&grep_mutex);
73 }
74
75 static inline void grep_unlock(void)
76 {
77         pthread_mutex_unlock(&grep_mutex);
78 }
79
80 /* Signalled when a new work_item is added to todo. */
81 static pthread_cond_t cond_add;
82
83 /* Signalled when the result from one work_item is written to
84  * stdout.
85  */
86 static pthread_cond_t cond_write;
87
88 /* Signalled when we are finished with everything. */
89 static pthread_cond_t cond_result;
90
91 static int skip_first_line;
92
93 static void add_work(struct grep_opt *opt, const struct grep_source *gs)
94 {
95         grep_lock();
96
97         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
98                 pthread_cond_wait(&cond_write, &grep_mutex);
99         }
100
101         todo[todo_end].source = *gs;
102         if (opt->binary != GREP_BINARY_TEXT)
103                 grep_source_load_driver(&todo[todo_end].source,
104                                         opt->repo->index);
105         todo[todo_end].done = 0;
106         strbuf_reset(&todo[todo_end].out);
107         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
108
109         pthread_cond_signal(&cond_add);
110         grep_unlock();
111 }
112
113 static struct work_item *get_work(void)
114 {
115         struct work_item *ret;
116
117         grep_lock();
118         while (todo_start == todo_end && !all_work_added) {
119                 pthread_cond_wait(&cond_add, &grep_mutex);
120         }
121
122         if (todo_start == todo_end && all_work_added) {
123                 ret = NULL;
124         } else {
125                 ret = &todo[todo_start];
126                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
127         }
128         grep_unlock();
129         return ret;
130 }
131
132 static void work_done(struct work_item *w)
133 {
134         int old_done;
135
136         grep_lock();
137         w->done = 1;
138         old_done = todo_done;
139         for(; todo[todo_done].done && todo_done != todo_start;
140             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
141                 w = &todo[todo_done];
142                 if (w->out.len) {
143                         const char *p = w->out.buf;
144                         size_t len = w->out.len;
145
146                         /* Skip the leading hunk mark of the first file. */
147                         if (skip_first_line) {
148                                 while (len) {
149                                         len--;
150                                         if (*p++ == '\n')
151                                                 break;
152                                 }
153                                 skip_first_line = 0;
154                         }
155
156                         write_or_die(1, p, len);
157                 }
158                 grep_source_clear(&w->source);
159         }
160
161         if (old_done != todo_done)
162                 pthread_cond_signal(&cond_write);
163
164         if (all_work_added && todo_done == todo_end)
165                 pthread_cond_signal(&cond_result);
166
167         grep_unlock();
168 }
169
170 static void *run(void *arg)
171 {
172         int hit = 0;
173         struct grep_opt *opt = arg;
174
175         while (1) {
176                 struct work_item *w = get_work();
177                 if (!w)
178                         break;
179
180                 opt->output_priv = w;
181                 hit |= grep_source(opt, &w->source);
182                 grep_source_clear_data(&w->source);
183                 work_done(w);
184         }
185         free_grep_patterns(arg);
186         free(arg);
187
188         return (void*) (intptr_t) hit;
189 }
190
191 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
192 {
193         struct work_item *w = opt->output_priv;
194         strbuf_add(&w->out, buf, size);
195 }
196
197 static void start_threads(struct grep_opt *opt)
198 {
199         int i;
200
201         pthread_mutex_init(&grep_mutex, NULL);
202         pthread_mutex_init(&grep_read_mutex, NULL);
203         pthread_mutex_init(&grep_attr_mutex, NULL);
204         pthread_cond_init(&cond_add, NULL);
205         pthread_cond_init(&cond_write, NULL);
206         pthread_cond_init(&cond_result, NULL);
207         grep_use_locks = 1;
208
209         for (i = 0; i < ARRAY_SIZE(todo); i++) {
210                 strbuf_init(&todo[i].out, 0);
211         }
212
213         threads = xcalloc(num_threads, sizeof(*threads));
214         for (i = 0; i < num_threads; i++) {
215                 int err;
216                 struct grep_opt *o = grep_opt_dup(opt);
217                 o->output = strbuf_out;
218                 if (i)
219                         o->debug = 0;
220                 compile_grep_patterns(o);
221                 err = pthread_create(&threads[i], NULL, run, o);
222
223                 if (err)
224                         die(_("grep: failed to create thread: %s"),
225                             strerror(err));
226         }
227 }
228
229 static int wait_all(void)
230 {
231         int hit = 0;
232         int i;
233
234         if (!HAVE_THREADS)
235                 BUG("Never call this function unless you have started threads");
236
237         grep_lock();
238         all_work_added = 1;
239
240         /* Wait until all work is done. */
241         while (todo_done != todo_end)
242                 pthread_cond_wait(&cond_result, &grep_mutex);
243
244         /* Wake up all the consumer threads so they can see that there
245          * is no more work to do.
246          */
247         pthread_cond_broadcast(&cond_add);
248         grep_unlock();
249
250         for (i = 0; i < num_threads; i++) {
251                 void *h;
252                 pthread_join(threads[i], &h);
253                 hit |= (int) (intptr_t) h;
254         }
255
256         free(threads);
257
258         pthread_mutex_destroy(&grep_mutex);
259         pthread_mutex_destroy(&grep_read_mutex);
260         pthread_mutex_destroy(&grep_attr_mutex);
261         pthread_cond_destroy(&cond_add);
262         pthread_cond_destroy(&cond_write);
263         pthread_cond_destroy(&cond_result);
264         grep_use_locks = 0;
265
266         return hit;
267 }
268
269 static int grep_cmd_config(const char *var, const char *value, void *cb)
270 {
271         int st = grep_config(var, value, cb);
272         if (git_color_default_config(var, value, cb) < 0)
273                 st = -1;
274
275         if (!strcmp(var, "grep.threads")) {
276                 num_threads = git_config_int(var, value);
277                 if (num_threads < 0)
278                         die(_("invalid number of threads specified (%d) for %s"),
279                             num_threads, var);
280                 else if (!HAVE_THREADS && num_threads > 1) {
281                         /*
282                          * TRANSLATORS: %s is the configuration
283                          * variable for tweaking threads, currently
284                          * grep.threads
285                          */
286                         warning(_("no threads support, ignoring %s"), var);
287                         num_threads = 1;
288                 }
289         }
290
291         if (!strcmp(var, "submodule.recurse"))
292                 recurse_submodules = git_config_bool(var, value);
293
294         return st;
295 }
296
297 static void *lock_and_read_oid_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
298 {
299         void *data;
300
301         grep_read_lock();
302         data = read_object_file(oid, type, size);
303         grep_read_unlock();
304         return data;
305 }
306
307 static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
308                      const char *filename, int tree_name_len,
309                      const char *path)
310 {
311         struct strbuf pathbuf = STRBUF_INIT;
312         struct grep_source gs;
313
314         if (opt->relative && opt->prefix_length) {
315                 quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
316                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
317         } else {
318                 strbuf_addstr(&pathbuf, filename);
319         }
320
321         grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
322         strbuf_release(&pathbuf);
323
324         if (num_threads > 1) {
325                 /*
326                  * add_work() copies gs and thus assumes ownership of
327                  * its fields, so do not call grep_source_clear()
328                  */
329                 add_work(opt, &gs);
330                 return 0;
331         } else {
332                 int hit;
333
334                 hit = grep_source(opt, &gs);
335
336                 grep_source_clear(&gs);
337                 return hit;
338         }
339 }
340
341 static int grep_file(struct grep_opt *opt, const char *filename)
342 {
343         struct strbuf buf = STRBUF_INIT;
344         struct grep_source gs;
345
346         if (opt->relative && opt->prefix_length)
347                 quote_path_relative(filename, opt->prefix, &buf);
348         else
349                 strbuf_addstr(&buf, filename);
350
351         grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
352         strbuf_release(&buf);
353
354         if (num_threads > 1) {
355                 /*
356                  * add_work() copies gs and thus assumes ownership of
357                  * its fields, so do not call grep_source_clear()
358                  */
359                 add_work(opt, &gs);
360                 return 0;
361         } else {
362                 int hit;
363
364                 hit = grep_source(opt, &gs);
365
366                 grep_source_clear(&gs);
367                 return hit;
368         }
369 }
370
371 static void append_path(struct grep_opt *opt, const void *data, size_t len)
372 {
373         struct string_list *path_list = opt->output_priv;
374
375         if (len == 1 && *(const char *)data == '\0')
376                 return;
377         string_list_append(path_list, xstrndup(data, len));
378 }
379
380 static void run_pager(struct grep_opt *opt, const char *prefix)
381 {
382         struct string_list *path_list = opt->output_priv;
383         struct child_process child = CHILD_PROCESS_INIT;
384         int i, status;
385
386         for (i = 0; i < path_list->nr; i++)
387                 argv_array_push(&child.args, path_list->items[i].string);
388         child.dir = prefix;
389         child.use_shell = 1;
390
391         status = run_command(&child);
392         if (status)
393                 exit(status);
394 }
395
396 static int grep_cache(struct grep_opt *opt, struct repository *repo,
397                       const struct pathspec *pathspec, int cached);
398 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
399                      struct tree_desc *tree, struct strbuf *base, int tn_len,
400                      int check_attr, struct repository *repo);
401
402 static int grep_submodule(struct grep_opt *opt, struct repository *superproject,
403                           const struct pathspec *pathspec,
404                           const struct object_id *oid,
405                           const char *filename, const char *path)
406 {
407         struct repository subrepo;
408         const struct submodule *sub = submodule_from_path(superproject,
409                                                           &null_oid, path);
410
411         int hit;
412
413         /*
414          * NEEDSWORK: submodules functions need to be protected because they
415          * access the object store via config_from_gitmodules(): the latter
416          * uses get_oid() which, for now, relies on the global the_repository
417          * object.
418          */
419         grep_read_lock();
420
421         if (!is_submodule_active(superproject, path)) {
422                 grep_read_unlock();
423                 return 0;
424         }
425
426         if (repo_submodule_init(&subrepo, superproject, sub)) {
427                 grep_read_unlock();
428                 return 0;
429         }
430
431         repo_read_gitmodules(&subrepo);
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         add_to_alternates_memory(subrepo.objects->objectdir);
444         grep_read_unlock();
445
446         if (oid) {
447                 struct object *object;
448                 struct tree_desc tree;
449                 void *data;
450                 unsigned long size;
451                 struct strbuf base = STRBUF_INIT;
452
453                 object = parse_object_or_die(oid, oid_to_hex(oid));
454
455                 grep_read_lock();
456                 data = read_object_with_reference(&object->oid, tree_type,
457                                                   &size, NULL);
458                 grep_read_unlock();
459
460                 if (!data)
461                         die(_("unable to read tree (%s)"), oid_to_hex(&object->oid));
462
463                 strbuf_addstr(&base, filename);
464                 strbuf_addch(&base, '/');
465
466                 init_tree_desc(&tree, data, size);
467                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
468                                 object->type == OBJ_COMMIT, &subrepo);
469                 strbuf_release(&base);
470                 free(data);
471         } else {
472                 hit = grep_cache(opt, &subrepo, pathspec, 1);
473         }
474
475         repo_clear(&subrepo);
476         return hit;
477 }
478
479 static int grep_cache(struct grep_opt *opt, struct repository *repo,
480                       const struct pathspec *pathspec, int cached)
481 {
482         int hit = 0;
483         int nr;
484         struct strbuf name = STRBUF_INIT;
485         int name_base_len = 0;
486         if (repo->submodule_prefix) {
487                 name_base_len = strlen(repo->submodule_prefix);
488                 strbuf_addstr(&name, repo->submodule_prefix);
489         }
490
491         if (repo_read_index(repo) < 0)
492                 die(_("index file corrupt"));
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(repo->index, 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(repo->index, 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 {
608         if (obj->type == OBJ_BLOB)
609                 return grep_oid(opt, &obj->oid, name, 0, path);
610         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
611                 struct tree_desc tree;
612                 void *data;
613                 unsigned long size;
614                 struct strbuf base;
615                 int hit, len;
616
617                 grep_read_lock();
618                 data = read_object_with_reference(&obj->oid, tree_type,
619                                                   &size, NULL);
620                 grep_read_unlock();
621
622                 if (!data)
623                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
624
625                 len = name ? strlen(name) : 0;
626                 strbuf_init(&base, PATH_MAX + len + 1);
627                 if (len) {
628                         strbuf_add(&base, name, len);
629                         strbuf_addch(&base, ':');
630                 }
631                 init_tree_desc(&tree, data, size);
632                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
633                                 obj->type == OBJ_COMMIT, the_repository);
634                 strbuf_release(&base);
635                 free(data);
636                 return hit;
637         }
638         die(_("unable to grep from object of type %s"), type_name(obj->type));
639 }
640
641 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
642                         const struct object_array *list)
643 {
644         unsigned int i;
645         int hit = 0;
646         const unsigned int nr = list->nr;
647
648         for (i = 0; i < nr; i++) {
649                 struct object *real_obj;
650                 real_obj = deref_tag(the_repository, list->objects[i].item,
651                                      NULL, 0);
652
653                 /* load the gitmodules file for this rev */
654                 if (recurse_submodules) {
655                         submodule_free(the_repository);
656                         gitmodules_config_oid(&real_obj->oid);
657                 }
658                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
659                                 list->objects[i].path)) {
660                         hit = 1;
661                         if (opt->status_only)
662                                 break;
663                 }
664         }
665         return hit;
666 }
667
668 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
669                           int exc_std, int use_index)
670 {
671         struct dir_struct dir;
672         int i, hit = 0;
673
674         memset(&dir, 0, sizeof(dir));
675         if (!use_index)
676                 dir.flags |= DIR_NO_GITLINKS;
677         if (exc_std)
678                 setup_standard_excludes(&dir);
679
680         fill_directory(&dir, &the_index, pathspec);
681         for (i = 0; i < dir.nr; i++) {
682                 if (!dir_path_match(&the_index, dir.entries[i], pathspec, 0, NULL))
683                         continue;
684                 hit |= grep_file(opt, dir.entries[i]->name);
685                 if (hit && opt->status_only)
686                         break;
687         }
688         return hit;
689 }
690
691 static int context_callback(const struct option *opt, const char *arg,
692                             int unset)
693 {
694         struct grep_opt *grep_opt = opt->value;
695         int value;
696         const char *endp;
697
698         if (unset) {
699                 grep_opt->pre_context = grep_opt->post_context = 0;
700                 return 0;
701         }
702         value = strtol(arg, (char **)&endp, 10);
703         if (*endp) {
704                 return error(_("switch `%c' expects a numerical value"),
705                              opt->short_name);
706         }
707         grep_opt->pre_context = grep_opt->post_context = value;
708         return 0;
709 }
710
711 static int file_callback(const struct option *opt, const char *arg, int unset)
712 {
713         struct grep_opt *grep_opt = opt->value;
714         int from_stdin;
715         FILE *patterns;
716         int lno = 0;
717         struct strbuf sb = STRBUF_INIT;
718
719         BUG_ON_OPT_NEG(unset);
720
721         from_stdin = !strcmp(arg, "-");
722         patterns = from_stdin ? stdin : fopen(arg, "r");
723         if (!patterns)
724                 die_errno(_("cannot open '%s'"), arg);
725         while (strbuf_getline(&sb, patterns) == 0) {
726                 /* ignore empty line like grep does */
727                 if (sb.len == 0)
728                         continue;
729
730                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
731                                 GREP_PATTERN);
732         }
733         if (!from_stdin)
734                 fclose(patterns);
735         strbuf_release(&sb);
736         return 0;
737 }
738
739 static int not_callback(const struct option *opt, const char *arg, int unset)
740 {
741         struct grep_opt *grep_opt = opt->value;
742         BUG_ON_OPT_NEG(unset);
743         BUG_ON_OPT_ARG(arg);
744         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
745         return 0;
746 }
747
748 static int and_callback(const struct option *opt, const char *arg, int unset)
749 {
750         struct grep_opt *grep_opt = opt->value;
751         BUG_ON_OPT_NEG(unset);
752         BUG_ON_OPT_ARG(arg);
753         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
754         return 0;
755 }
756
757 static int open_callback(const struct option *opt, const char *arg, int unset)
758 {
759         struct grep_opt *grep_opt = opt->value;
760         BUG_ON_OPT_NEG(unset);
761         BUG_ON_OPT_ARG(arg);
762         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
763         return 0;
764 }
765
766 static int close_callback(const struct option *opt, const char *arg, int unset)
767 {
768         struct grep_opt *grep_opt = opt->value;
769         BUG_ON_OPT_NEG(unset);
770         BUG_ON_OPT_ARG(arg);
771         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
772         return 0;
773 }
774
775 static int pattern_callback(const struct option *opt, const char *arg,
776                             int unset)
777 {
778         struct grep_opt *grep_opt = opt->value;
779         BUG_ON_OPT_NEG(unset);
780         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
781         return 0;
782 }
783
784 int cmd_grep(int argc, const char **argv, const char *prefix)
785 {
786         int hit = 0;
787         int cached = 0, untracked = 0, opt_exclude = -1;
788         int seen_dashdash = 0;
789         int external_grep_allowed__ignored;
790         const char *show_in_pager = NULL, *default_pager = "dummy";
791         struct grep_opt opt;
792         struct object_array list = OBJECT_ARRAY_INIT;
793         struct pathspec pathspec;
794         struct string_list path_list = STRING_LIST_INIT_NODUP;
795         int i;
796         int dummy;
797         int use_index = 1;
798         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
799         int allow_revs;
800
801         struct option options[] = {
802                 OPT_BOOL(0, "cached", &cached,
803                         N_("search in index instead of in the work tree")),
804                 OPT_NEGBIT(0, "no-index", &use_index,
805                          N_("find in contents not managed by git"), 1),
806                 OPT_BOOL(0, "untracked", &untracked,
807                         N_("search in both tracked and untracked files")),
808                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
809                             N_("ignore files specified via '.gitignore'"), 1),
810                 OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
811                          N_("recursively search in each submodule")),
812                 OPT_GROUP(""),
813                 OPT_BOOL('v', "invert-match", &opt.invert,
814                         N_("show non-matching lines")),
815                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
816                         N_("case insensitive matching")),
817                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
818                         N_("match patterns only at word boundaries")),
819                 OPT_SET_INT('a', "text", &opt.binary,
820                         N_("process binary files as text"), GREP_BINARY_TEXT),
821                 OPT_SET_INT('I', NULL, &opt.binary,
822                         N_("don't match patterns in binary files"),
823                         GREP_BINARY_NOMATCH),
824                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
825                          N_("process binary files with textconv filters")),
826                 OPT_SET_INT('r', "recursive", &opt.max_depth,
827                             N_("search in subdirectories (default)"), -1),
828                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
829                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
830                         NULL, 1 },
831                 OPT_GROUP(""),
832                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
833                             N_("use extended POSIX regular expressions"),
834                             GREP_PATTERN_TYPE_ERE),
835                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
836                             N_("use basic POSIX regular expressions (default)"),
837                             GREP_PATTERN_TYPE_BRE),
838                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
839                             N_("interpret patterns as fixed strings"),
840                             GREP_PATTERN_TYPE_FIXED),
841                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
842                             N_("use Perl-compatible regular expressions"),
843                             GREP_PATTERN_TYPE_PCRE),
844                 OPT_GROUP(""),
845                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
846                 OPT_BOOL(0, "column", &opt.columnnum, N_("show column number of first match")),
847                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
848                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
849                 OPT_NEGBIT(0, "full-name", &opt.relative,
850                         N_("show filenames relative to top directory"), 1),
851                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
852                         N_("show only filenames instead of matching lines")),
853                 OPT_BOOL(0, "name-only", &opt.name_only,
854                         N_("synonym for --files-with-matches")),
855                 OPT_BOOL('L', "files-without-match",
856                         &opt.unmatch_name_only,
857                         N_("show only the names of files without match")),
858                 OPT_BOOL_F('z', "null", &opt.null_following_name,
859                            N_("print NUL after filenames"),
860                            PARSE_OPT_NOCOMPLETE),
861                 OPT_BOOL('o', "only-matching", &opt.only_matching,
862                         N_("show only matching parts of a line")),
863                 OPT_BOOL('c', "count", &opt.count,
864                         N_("show the number of matches instead of matching lines")),
865                 OPT__COLOR(&opt.color, N_("highlight matches")),
866                 OPT_BOOL(0, "break", &opt.file_break,
867                         N_("print empty line between matches from different files")),
868                 OPT_BOOL(0, "heading", &opt.heading,
869                         N_("show filename only once above matches from same file")),
870                 OPT_GROUP(""),
871                 OPT_CALLBACK('C', "context", &opt, N_("n"),
872                         N_("show <n> context lines before and after matches"),
873                         context_callback),
874                 OPT_INTEGER('B', "before-context", &opt.pre_context,
875                         N_("show <n> context lines before matches")),
876                 OPT_INTEGER('A', "after-context", &opt.post_context,
877                         N_("show <n> context lines after matches")),
878                 OPT_INTEGER(0, "threads", &num_threads,
879                         N_("use <n> worker threads")),
880                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
881                         context_callback),
882                 OPT_BOOL('p', "show-function", &opt.funcname,
883                         N_("show a line with the function name before matches")),
884                 OPT_BOOL('W', "function-context", &opt.funcbody,
885                         N_("show the surrounding function")),
886                 OPT_GROUP(""),
887                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
888                         N_("read patterns from file"), file_callback),
889                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
890                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
891                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
892                   N_("combine patterns specified with -e"),
893                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
894                 OPT_BOOL(0, "or", &dummy, ""),
895                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
896                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
897                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
898                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
899                   open_callback },
900                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
901                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
902                   close_callback },
903                 OPT__QUIET(&opt.status_only,
904                            N_("indicate hit with exit status without output")),
905                 OPT_BOOL(0, "all-match", &opt.all_match,
906                         N_("show only matches from files that match all patterns")),
907                 OPT_SET_INT_F(0, "debug", &opt.debug,
908                               N_("show parse tree for grep expression"),
909                               1, PARSE_OPT_HIDDEN),
910                 OPT_GROUP(""),
911                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
912                         N_("pager"), N_("show matching files in the pager"),
913                         PARSE_OPT_OPTARG | PARSE_OPT_NOCOMPLETE,
914                         NULL, (intptr_t)default_pager },
915                 OPT_BOOL_F(0, "ext-grep", &external_grep_allowed__ignored,
916                            N_("allow calling of grep(1) (ignored by this build)"),
917                            PARSE_OPT_NOCOMPLETE),
918                 OPT_END()
919         };
920
921         init_grep_defaults(the_repository);
922         git_config(grep_cmd_config, NULL);
923         grep_init(&opt, the_repository, prefix);
924
925         /*
926          * If there is no -- then the paths must exist in the working
927          * tree.  If there is no explicit pattern specified with -e or
928          * -f, we take the first unrecognized non option to be the
929          * pattern, but then what follows it must be zero or more
930          * valid refs up to the -- (if exists), and then existing
931          * paths.  If there is an explicit pattern, then the first
932          * unrecognized non option is the beginning of the refs list
933          * that continues up to the -- (if exists), and then paths.
934          */
935         argc = parse_options(argc, argv, prefix, options, grep_usage,
936                              PARSE_OPT_KEEP_DASHDASH |
937                              PARSE_OPT_STOP_AT_NON_OPTION);
938         grep_commit_pattern_type(pattern_type_arg, &opt);
939
940         if (use_index && !startup_info->have_repository) {
941                 int fallback = 0;
942                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
943                 if (fallback)
944                         use_index = 0;
945                 else
946                         /* die the same way as if we did it at the beginning */
947                         setup_git_directory();
948         }
949
950         /*
951          * skip a -- separator; we know it cannot be
952          * separating revisions from pathnames if
953          * we haven't even had any patterns yet
954          */
955         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
956                 argv++;
957                 argc--;
958         }
959
960         /* First unrecognized non-option token */
961         if (argc > 0 && !opt.pattern_list) {
962                 append_grep_pattern(&opt, argv[0], "command line", 0,
963                                     GREP_PATTERN);
964                 argv++;
965                 argc--;
966         }
967
968         if (show_in_pager == default_pager)
969                 show_in_pager = git_pager(1);
970         if (show_in_pager) {
971                 opt.color = 0;
972                 opt.name_only = 1;
973                 opt.null_following_name = 1;
974                 opt.output_priv = &path_list;
975                 opt.output = append_path;
976                 string_list_append(&path_list, show_in_pager);
977         }
978
979         if (!opt.pattern_list)
980                 die(_("no pattern given"));
981
982         /* --only-matching has no effect with --invert. */
983         if (opt.invert)
984                 opt.only_matching = 0;
985
986         /*
987          * We have to find "--" in a separate pass, because its presence
988          * influences how we will parse arguments that come before it.
989          */
990         for (i = 0; i < argc; i++) {
991                 if (!strcmp(argv[i], "--")) {
992                         seen_dashdash = 1;
993                         break;
994                 }
995         }
996
997         /*
998          * Resolve any rev arguments. If we have a dashdash, then everything up
999          * to it must resolve as a rev. If not, then we stop at the first
1000          * non-rev and assume everything else is a path.
1001          */
1002         allow_revs = use_index && !untracked;
1003         for (i = 0; i < argc; i++) {
1004                 const char *arg = argv[i];
1005                 struct object_id oid;
1006                 struct object_context oc;
1007                 struct object *object;
1008
1009                 if (!strcmp(arg, "--")) {
1010                         i++;
1011                         break;
1012                 }
1013
1014                 if (!allow_revs) {
1015                         if (seen_dashdash)
1016                                 die(_("--no-index or --untracked cannot be used with revs"));
1017                         break;
1018                 }
1019
1020                 if (get_oid_with_context(arg, GET_OID_RECORD_PATH,
1021                                          &oid, &oc)) {
1022                         if (seen_dashdash)
1023                                 die(_("unable to resolve revision: %s"), arg);
1024                         break;
1025                 }
1026
1027                 object = parse_object_or_die(&oid, arg);
1028                 if (!seen_dashdash)
1029                         verify_non_filename(prefix, arg);
1030                 add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
1031                 free(oc.path);
1032         }
1033
1034         /*
1035          * Anything left over is presumed to be a path. But in the non-dashdash
1036          * "do what I mean" case, we verify and complain when that isn't true.
1037          */
1038         if (!seen_dashdash) {
1039                 int j;
1040                 for (j = i; j < argc; j++)
1041                         verify_filename(prefix, argv[j], j == i && allow_revs);
1042         }
1043
1044         parse_pathspec(&pathspec, 0,
1045                        PATHSPEC_PREFER_CWD |
1046                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
1047                        prefix, argv + i);
1048         pathspec.max_depth = opt.max_depth;
1049         pathspec.recursive = 1;
1050         pathspec.recurse_submodules = !!recurse_submodules;
1051
1052         if (list.nr || cached || show_in_pager) {
1053                 if (num_threads > 1)
1054                         warning(_("invalid option combination, ignoring --threads"));
1055                 num_threads = 1;
1056         } else if (!HAVE_THREADS && num_threads > 1) {
1057                 warning(_("no threads support, ignoring --threads"));
1058                 num_threads = 1;
1059         } else if (num_threads < 0)
1060                 die(_("invalid number of threads specified (%d)"), num_threads);
1061         else if (num_threads == 0)
1062                 num_threads = HAVE_THREADS ? GREP_NUM_THREADS_DEFAULT : 1;
1063
1064         if (num_threads > 1) {
1065                 if (!HAVE_THREADS)
1066                         BUG("Somebody got num_threads calculation wrong!");
1067                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
1068                     && (opt.pre_context || opt.post_context ||
1069                         opt.file_break || opt.funcbody))
1070                         skip_first_line = 1;
1071                 start_threads(&opt);
1072         } else {
1073                 /*
1074                  * The compiled patterns on the main path are only
1075                  * used when not using threading. Otherwise
1076                  * start_threads() above calls compile_grep_patterns()
1077                  * for each thread.
1078                  */
1079                 compile_grep_patterns(&opt);
1080         }
1081
1082         if (show_in_pager && (cached || list.nr))
1083                 die(_("--open-files-in-pager only works on the worktree"));
1084
1085         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
1086                 const char *pager = path_list.items[0].string;
1087                 int len = strlen(pager);
1088
1089                 if (len > 4 && is_dir_sep(pager[len - 5]))
1090                         pager += len - 4;
1091
1092                 if (opt.ignore_case && !strcmp("less", pager))
1093                         string_list_append(&path_list, "-I");
1094
1095                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
1096                         struct strbuf buf = STRBUF_INIT;
1097                         strbuf_addf(&buf, "+/%s%s",
1098                                         strcmp("less", pager) ? "" : "*",
1099                                         opt.pattern_list->pattern);
1100                         string_list_append(&path_list, buf.buf);
1101                         strbuf_detach(&buf, NULL);
1102                 }
1103         }
1104
1105         if (recurse_submodules && (!use_index || untracked))
1106                 die(_("option not supported with --recurse-submodules"));
1107
1108         if (!show_in_pager && !opt.status_only)
1109                 setup_pager();
1110
1111         if (!use_index && (untracked || cached))
1112                 die(_("--cached or --untracked cannot be used with --no-index"));
1113
1114         if (!use_index || untracked) {
1115                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
1116                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
1117         } else if (0 <= opt_exclude) {
1118                 die(_("--[no-]exclude-standard cannot be used for tracked contents"));
1119         } else if (!list.nr) {
1120                 if (!cached)
1121                         setup_work_tree();
1122
1123                 hit = grep_cache(&opt, the_repository, &pathspec, cached);
1124         } else {
1125                 if (cached)
1126                         die(_("both --cached and trees are given"));
1127
1128                 hit = grep_objects(&opt, &pathspec, &list);
1129         }
1130
1131         if (num_threads > 1)
1132                 hit |= wait_all();
1133         if (hit && show_in_pager)
1134                 run_pager(&opt, prefix);
1135         clear_pathspec(&pathspec);
1136         free_grep_patterns(&opt);
1137         return !hit;
1138 }