summaryrefslogtreecommitdiff
path: root/builtin/grep.c
blob: fc7a9a928302f79d26fd4d0f57c32f8efd7b9f6e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
/*
 * Builtin "git grep"
 *
 * Copyright (c) 2006 Junio C Hamano
 */
#include "cache.h"
#include "repository.h"
#include "config.h"
#include "blob.h"
#include "tree.h"
#include "commit.h"
#include "tag.h"
#include "tree-walk.h"
#include "builtin.h"
#include "parse-options.h"
#include "string-list.h"
#include "run-command.h"
#include "userdiff.h"
#include "grep.h"
#include "quote.h"
#include "dir.h"
#include "pathspec.h"
#include "submodule.h"
#include "submodule-config.h"
#include "object-store.h"
 
static char const * const grep_usage[] = {
	N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
	NULL
};
 
static int recurse_submodules;
 
#define GREP_NUM_THREADS_DEFAULT 8
static int num_threads;
 
static pthread_t *threads;
 
/* We use one producer thread and THREADS consumer
 * threads. The producer adds struct work_items to 'todo' and the
 * consumers pick work items from the same array.
 */
struct work_item {
	struct grep_source source;
	char done;
	struct strbuf out;
};
 
/* In the range [todo_done, todo_start) in 'todo' we have work_items
 * that have been or are processed by a consumer thread. We haven't
 * written the result for these to stdout yet.
 *
 * The work_items in [todo_start, todo_end) are waiting to be picked
 * up by a consumer thread.
 *
 * The ranges are modulo TODO_SIZE.
 */
#define TODO_SIZE 128
static struct work_item todo[TODO_SIZE];
static int todo_start;
static int todo_end;
static int todo_done;
 
/* Has all work items been added? */
static int all_work_added;
 
/* This lock protects all the variables above. */
static pthread_mutex_t grep_mutex;
 
static inline void grep_lock(void)
{
	pthread_mutex_lock(&grep_mutex);
}
 
static inline void grep_unlock(void)
{
	pthread_mutex_unlock(&grep_mutex);
}
 
/* Signalled when a new work_item is added to todo. */
static pthread_cond_t cond_add;
 
/* Signalled when the result from one work_item is written to
 * stdout.
 */
static pthread_cond_t cond_write;
 
/* Signalled when we are finished with everything. */
static pthread_cond_t cond_result;
 
static int skip_first_line;
 
static void add_work(struct grep_opt *opt, const struct grep_source *gs)
{
	grep_lock();
 
	while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
		pthread_cond_wait(&cond_write, &grep_mutex);
	}
 
	todo[todo_end].source = *gs;
	if (opt->binary != GREP_BINARY_TEXT)
		grep_source_load_driver(&todo[todo_end].source,
					opt->repo->index);
	todo[todo_end].done = 0;
	strbuf_reset(&todo[todo_end].out);
	todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 
	pthread_cond_signal(&cond_add);
	grep_unlock();
}
 
static struct work_item *get_work(void)
{
	struct work_item *ret;
 
	grep_lock();
	while (todo_start == todo_end && !all_work_added) {
		pthread_cond_wait(&cond_add, &grep_mutex);
	}
 
	if (todo_start == todo_end && all_work_added) {
		ret = NULL;
	} else {
		ret = &todo[todo_start];
		todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
	}
	grep_unlock();
	return ret;
}
 
static void work_done(struct work_item *w)
{
	int old_done;
 
	grep_lock();
	w->done = 1;
	old_done = todo_done;
	for(; todo[todo_done].done && todo_done != todo_start;
	    todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
		w = &todo[todo_done];
		if (w->out.len) {
			const char *p = w->out.buf;
			size_t len = w->out.len;
 
			/* Skip the leading hunk mark of the first file. */
			if (skip_first_line) {
				while (len) {
					len--;
					if (*p++ == '\n')
						break;
				}
				skip_first_line = 0;
			}
 
			write_or_die(1, p, len);
		}
		grep_source_clear(&w->source);
	}
 
	if (old_done != todo_done)
		pthread_cond_signal(&cond_write);
 
	if (all_work_added && todo_done == todo_end)
		pthread_cond_signal(&cond_result);
 
	grep_unlock();
}
 
static void *run(void *arg)
{
	int hit = 0;
	struct grep_opt *opt = arg;
 
	while (1) {
		struct work_item *w = get_work();
		if (!w)
			break;
 
		opt->output_priv = w;
		hit |= grep_source(opt, &w->source);
		grep_source_clear_data(&w->source);
		work_done(w);
	}
	free_grep_patterns(arg);
	free(arg);
 
	return (void*) (intptr_t) hit;
}
 
static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
{
	struct work_item *w = opt->output_priv;
	strbuf_add(&w->out, buf, size);
}
 
static void start_threads(struct grep_opt *opt)
{
	int i;
 
	pthread_mutex_init(&grep_mutex, NULL);
	pthread_mutex_init(&grep_read_mutex, NULL);
	pthread_mutex_init(&grep_attr_mutex, NULL);
	pthread_cond_init(&cond_add, NULL);
	pthread_cond_init(&cond_write, NULL);
	pthread_cond_init(&cond_result, NULL);
	grep_use_locks = 1;
 
	for (i = 0; i < ARRAY_SIZE(todo); i++) {
		strbuf_init(&todo[i].out, 0);
	}
 
	threads = xcalloc(num_threads, sizeof(*threads));
	for (i = 0; i < num_threads; i++) {
		int err;
		struct grep_opt *o = grep_opt_dup(opt);
		o->output = strbuf_out;
		if (i)
			o->debug = 0;
		compile_grep_patterns(o);
		err = pthread_create(&threads[i], NULL, run, o);
 
		if (err)
			die(_("grep: failed to create thread: %s"),
			    strerror(err));
	}
}
 
static int wait_all(void)
{
	int hit = 0;
	int i;
 
	if (!HAVE_THREADS)
		BUG("Never call this function unless you have started threads");
 
	grep_lock();
	all_work_added = 1;
 
	/* Wait until all work is done. */
	while (todo_done != todo_end)
		pthread_cond_wait(&cond_result, &grep_mutex);
 
	/* Wake up all the consumer threads so they can see that there
	 * is no more work to do.
	 */
	pthread_cond_broadcast(&cond_add);
	grep_unlock();
 
	for (i = 0; i < num_threads; i++) {
		void *h;
		pthread_join(threads[i], &h);
		hit |= (int) (intptr_t) h;
	}
 
	free(threads);
 
	pthread_mutex_destroy(&grep_mutex);
	pthread_mutex_destroy(&grep_read_mutex);
	pthread_mutex_destroy(&grep_attr_mutex);
	pthread_cond_destroy(&cond_add);
	pthread_cond_destroy(&cond_write);
	pthread_cond_destroy(&cond_result);
	grep_use_locks = 0;
 
	return hit;
}
 
static int grep_cmd_config(const char *var, const char *value, void *cb)
{
	int st = grep_config(var, value, cb);
	if (git_color_default_config(var, value, cb) < 0)
		st = -1;
 
	if (!strcmp(var, "grep.threads")) {
		num_threads = git_config_int(var, value);
		if (num_threads < 0)
			die(_("invalid number of threads specified (%d) for %s"),
			    num_threads, var);
		else if (!HAVE_THREADS && num_threads > 1) {
			/*
			 * TRANSLATORS: %s is the configuration
			 * variable for tweaking threads, currently
			 * grep.threads
			 */
			warning(_("no threads support, ignoring %s"), var);
			num_threads = 1;
		}
	}
 
	if (!strcmp(var, "submodule.recurse"))
		recurse_submodules = git_config_bool(var, value);
 
	return st;
}
 
static void *lock_and_read_oid_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
{
	void *data;
 
	grep_read_lock();
	data = read_object_file(oid, type, size);
	grep_read_unlock();
	return data;
}
 
static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
		     const char *filename, int tree_name_len,
		     const char *path)
{
	struct strbuf pathbuf = STRBUF_INIT;
	struct grep_source gs;
 
	if (opt->relative && opt->prefix_length) {
		quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
		strbuf_insert(&pathbuf, 0, filename, tree_name_len);
	} else {
		strbuf_addstr(&pathbuf, filename);
	}
 
	grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
	strbuf_release(&pathbuf);
 
	if (num_threads > 1) {
		/*
		 * add_work() copies gs and thus assumes ownership of
		 * its fields, so do not call grep_source_clear()
		 */
		add_work(opt, &gs);
		return 0;
	} else {
		int hit;
 
		hit = grep_source(opt, &gs);
 
		grep_source_clear(&gs);
		return hit;
	}
}
 
static int grep_file(struct grep_opt *opt, const char *filename)
{
	struct strbuf buf = STRBUF_INIT;
	struct grep_source gs;
 
	if (opt->relative && opt->prefix_length)
		quote_path_relative(filename, opt->prefix, &buf);
	else
		strbuf_addstr(&buf, filename);
 
	grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
	strbuf_release(&buf);
 
	if (num_threads > 1) {
		/*
		 * add_work() copies gs and thus assumes ownership of
		 * its fields, so do not call grep_source_clear()
		 */
		add_work(opt, &gs);
		return 0;
	} else {
		int hit;
 
		hit = grep_source(opt, &gs);
 
		grep_source_clear(&gs);
		return hit;
	}
}
 
static void append_path(struct grep_opt *opt, const void *data, size_t len)
{
	struct string_list *path_list = opt->output_priv;
 
	if (len == 1 && *(const char *)data == '\0')
		return;
	string_list_append(path_list, xstrndup(data, len));
}
 
static void run_pager(struct grep_opt *opt, const char *prefix)
{
	struct string_list *path_list = opt->output_priv;
	struct child_process child = CHILD_PROCESS_INIT;
	int i, status;
 
	for (i = 0; i < path_list->nr; i++)
		argv_array_push(&child.args, path_list->items[i].string);
	child.dir = prefix;
	child.use_shell = 1;
 
	status = run_command(&child);
	if (status)
		exit(status);
}
 
static int grep_cache(struct grep_opt *opt,
		      const struct pathspec *pathspec, int cached);
static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
		     struct tree_desc *tree, struct strbuf *base, int tn_len,
		     int check_attr);
 
static int grep_submodule(struct grep_opt *opt,
			  const struct pathspec *pathspec,
			  const struct object_id *oid,
			  const char *filename, const char *path)
{
	struct repository *superproject = opt->repo;
	struct repository submodule;
	struct grep_opt subopt;
	int hit;
 
	/*
	 * NEEDSWORK: submodules functions need to be protected because they
	 * access the object store via config_from_gitmodules(): the latter
	 * uses get_oid() which, for now, relies on the global the_repository
	 * object.
	 */
	grep_read_lock();
 
	if (!is_submodule_active(superproject, path)) {
		grep_read_unlock();
		return 0;
	}
 
	if (repo_submodule_init(&submodule, superproject, path)) {
		grep_read_unlock();
		return 0;
	}
 
	repo_read_gitmodules(&submodule);
 
	/*
	 * NEEDSWORK: This adds the submodule's object directory to the list of
	 * alternates for the single in-memory object store.  This has some bad
	 * consequences for memory (processed objects will never be freed) and
	 * performance (this increases the number of pack files git has to pay
	 * attention to, to the sum of the number of pack files in all the
	 * repositories processed so far).  This can be removed once the object
	 * store is no longer global and instead is a member of the repository
	 * object.
	 */
	add_to_alternates_memory(submodule.objects->odb->path);
	grep_read_unlock();
 
	memcpy(&subopt, opt, sizeof(subopt));
	subopt.repo = &submodule;
 
	if (oid) {
		struct object *object;
		struct tree_desc tree;
		void *data;
		unsigned long size;
		struct strbuf base = STRBUF_INIT;
 
		object = parse_object_or_die(oid, oid_to_hex(oid));
 
		grep_read_lock();
		data = read_object_with_reference(&object->oid, tree_type,
						  &size, NULL);
		grep_read_unlock();
 
		if (!data)
			die(_("unable to read tree (%s)"), oid_to_hex(&object->oid));
 
		strbuf_addstr(&base, filename);
		strbuf_addch(&base, '/');
 
		init_tree_desc(&tree, data, size);
		hit = grep_tree(&subopt, pathspec, &tree, &base, base.len,
				object->type == OBJ_COMMIT);
		strbuf_release(&base);
		free(data);
	} else {
		hit = grep_cache(&subopt, pathspec, 1);
	}
 
	repo_clear(&submodule);
	return hit;
}
 
static int grep_cache(struct grep_opt *opt,
		      const struct pathspec *pathspec, int cached)
{
	struct repository *repo = opt->repo;
	int hit = 0;
	int nr;
	struct strbuf name = STRBUF_INIT;
	int name_base_len = 0;
	if (repo->submodule_prefix) {
		name_base_len = strlen(repo->submodule_prefix);
		strbuf_addstr(&name, repo->submodule_prefix);
	}
 
	if (repo_read_index(repo) < 0)
		die(_("index file corrupt"));
 
	for (nr = 0; nr < repo->index->cache_nr; nr++) {
		const struct cache_entry *ce = repo->index->cache[nr];
		strbuf_setlen(&name, name_base_len);
		strbuf_addstr(&name, ce->name);
 
		if (S_ISREG(ce->ce_mode) &&
		    match_pathspec(repo->index, pathspec, name.buf, name.len, 0, NULL,
				   S_ISDIR(ce->ce_mode) ||
				   S_ISGITLINK(ce->ce_mode))) {
			/*
			 * If CE_VALID is on, we assume worktree file and its
			 * cache entry are identical, even if worktree file has
			 * been modified, so use cache version instead
			 */
			if (cached || (ce->ce_flags & CE_VALID) ||
			    ce_skip_worktree(ce)) {
				if (ce_stage(ce) || ce_intent_to_add(ce))
					continue;
				hit |= grep_oid(opt, &ce->oid, name.buf,
						 0, name.buf);
			} else {
				hit |= grep_file(opt, name.buf);
			}
		} else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
			   submodule_path_match(repo->index, pathspec, name.buf, NULL)) {
			hit |= grep_submodule(opt, pathspec, NULL, ce->name, ce->name);
		} else {
			continue;
		}
 
		if (ce_stage(ce)) {
			do {
				nr++;
			} while (nr < repo->index->cache_nr &&
				 !strcmp(ce->name, repo->index->cache[nr]->name));
			nr--; /* compensate for loop control */
		}
		if (hit && opt->status_only)
			break;
	}
 
	strbuf_release(&name);
	return hit;
}
 
static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
		     struct tree_desc *tree, struct strbuf *base, int tn_len,
		     int check_attr)
{
	struct repository *repo = opt->repo;
	int hit = 0;
	enum interesting match = entry_not_interesting;
	struct name_entry entry;
	int old_baselen = base->len;
	struct strbuf name = STRBUF_INIT;
	int name_base_len = 0;
	if (repo->submodule_prefix) {
		strbuf_addstr(&name, repo->submodule_prefix);
		name_base_len = name.len;
	}
 
	while (tree_entry(tree, &entry)) {
		int te_len = tree_entry_len(&entry);
 
		if (match != all_entries_interesting) {
			strbuf_addstr(&name, base->buf + tn_len);
			match = tree_entry_interesting(&entry, &name,
						       0, pathspec);
			strbuf_setlen(&name, name_base_len);
 
			if (match == all_entries_not_interesting)
				break;
			if (match == entry_not_interesting)
				continue;
		}
 
		strbuf_add(base, entry.path, te_len);
 
		if (S_ISREG(entry.mode)) {
			hit |= grep_oid(opt, entry.oid, base->buf, tn_len,
					 check_attr ? base->buf + tn_len : NULL);
		} else if (S_ISDIR(entry.mode)) {
			enum object_type type;
			struct tree_desc sub;
			void *data;
			unsigned long size;
 
			data = lock_and_read_oid_file(entry.oid, &type, &size);
			if (!data)
				die(_("unable to read tree (%s)"),
				    oid_to_hex(entry.oid));
 
			strbuf_addch(base, '/');
			init_tree_desc(&sub, data, size);
			hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
					 check_attr);
			free(data);
		} else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
			hit |= grep_submodule(opt, pathspec, entry.oid,
					      base->buf, base->buf + tn_len);
		}
 
		strbuf_setlen(base, old_baselen);
 
		if (hit && opt->status_only)
			break;
	}
 
	strbuf_release(&name);
	return hit;
}
 
static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
		       struct object *obj, const char *name, const char *path)
{
	if (obj->type == OBJ_BLOB)
		return grep_oid(opt, &obj->oid, name, 0, path);
	if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
		struct tree_desc tree;
		void *data;
		unsigned long size;
		struct strbuf base;
		int hit, len;
 
		grep_read_lock();
		data = read_object_with_reference(&obj->oid, tree_type,
						  &size, NULL);
		grep_read_unlock();
 
		if (!data)
			die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
 
		len = name ? strlen(name) : 0;
		strbuf_init(&base, PATH_MAX + len + 1);
		if (len) {
			strbuf_add(&base, name, len);
			strbuf_addch(&base, ':');
		}
		init_tree_desc(&tree, data, size);
		hit = grep_tree(opt, pathspec, &tree, &base, base.len,
				obj->type == OBJ_COMMIT);
		strbuf_release(&base);
		free(data);
		return hit;
	}
	die(_("unable to grep from object of type %s"), type_name(obj->type));
}
 
static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
			const struct object_array *list)
{
	unsigned int i;
	int hit = 0;
	const unsigned int nr = list->nr;
 
	for (i = 0; i < nr; i++) {
		struct object *real_obj;
		real_obj = deref_tag(opt->repo, list->objects[i].item,
				     NULL, 0);
 
		/* load the gitmodules file for this rev */
		if (recurse_submodules) {
			submodule_free(opt->repo);
			gitmodules_config_oid(&real_obj->oid);
		}
		if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
				list->objects[i].path)) {
			hit = 1;
			if (opt->status_only)
				break;
		}
	}
	return hit;
}
 
static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
			  int exc_std, int use_index)
{
	struct dir_struct dir;
	int i, hit = 0;
 
	memset(&dir, 0, sizeof(dir));
	if (!use_index)
		dir.flags |= DIR_NO_GITLINKS;
	if (exc_std)
		setup_standard_excludes(&dir);
 
	fill_directory(&dir, opt->repo->index, pathspec);
	for (i = 0; i < dir.nr; i++) {
		if (!dir_path_match(opt->repo->index, dir.entries[i], pathspec, 0, NULL))
			continue;
		hit |= grep_file(opt, dir.entries[i]->name);
		if (hit && opt->status_only)
			break;
	}
	return hit;
}
 
static int context_callback(const struct option *opt, const char *arg,
			    int unset)
{
	struct grep_opt *grep_opt = opt->value;
	int value;
	const char *endp;
 
	if (unset) {
		grep_opt->pre_context = grep_opt->post_context = 0;
		return 0;
	}
	value = strtol(arg, (char **)&endp, 10);
	if (*endp) {
		return error(_("switch `%c' expects a numerical value"),
			     opt->short_name);
	}
	grep_opt->pre_context = grep_opt->post_context = value;
	return 0;
}
 
static int file_callback(const struct option *opt, const char *arg, int unset)
{
	struct grep_opt *grep_opt = opt->value;
	int from_stdin;
	FILE *patterns;
	int lno = 0;
	struct strbuf sb = STRBUF_INIT;
 
	BUG_ON_OPT_NEG(unset);
 
	from_stdin = !strcmp(arg, "-");
	patterns = from_stdin ? stdin : fopen(arg, "r");
	if (!patterns)
		die_errno(_("cannot open '%s'"), arg);
	while (strbuf_getline(&sb, patterns) == 0) {
		/* ignore empty line like grep does */
		if (sb.len == 0)
			continue;
 
		append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
				GREP_PATTERN);
	}
	if (!from_stdin)
		fclose(patterns);
	strbuf_release(&sb);
	return 0;
}
 
static int not_callback(const struct option *opt, const char *arg, int unset)
{
	struct grep_opt *grep_opt = opt->value;
	BUG_ON_OPT_NEG(unset);
	BUG_ON_OPT_ARG(arg);
	append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
	return 0;
}
 
static int and_callback(const struct option *opt, const char *arg, int unset)
{
	struct grep_opt *grep_opt = opt->value;
	BUG_ON_OPT_NEG(unset);
	BUG_ON_OPT_ARG(arg);
	append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
	return 0;
}
 
static int open_callback(const struct option *opt, const char *arg, int unset)
{
	struct grep_opt *grep_opt = opt->value;
	BUG_ON_OPT_NEG(unset);
	BUG_ON_OPT_ARG(arg);
	append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
	return 0;
}
 
static int close_callback(const struct option *opt, const char *arg, int unset)
{
	struct grep_opt *grep_opt = opt->value;
	BUG_ON_OPT_NEG(unset);
	BUG_ON_OPT_ARG(arg);
	append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
	return 0;
}
 
static int pattern_callback(const struct option *opt, const char *arg,
			    int unset)
{
	struct grep_opt *grep_opt = opt->value;
	BUG_ON_OPT_NEG(unset);
	append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
	return 0;
}
 
int cmd_grep(int argc, const char **argv, const char *prefix)
{
	int hit = 0;
	int cached = 0, untracked = 0, opt_exclude = -1;
	int seen_dashdash = 0;
	int external_grep_allowed__ignored;
	const char *show_in_pager = NULL, *default_pager = "dummy";
	struct grep_opt opt;
	struct object_array list = OBJECT_ARRAY_INIT;
	struct pathspec pathspec;
	struct string_list path_list = STRING_LIST_INIT_NODUP;
	int i;
	int dummy;
	int use_index = 1;
	int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
	int allow_revs;
 
	struct option options[] = {
		OPT_BOOL(0, "cached", &cached,
			N_("search in index instead of in the work tree")),
		OPT_NEGBIT(0, "no-index", &use_index,
			 N_("find in contents not managed by git"), 1),
		OPT_BOOL(0, "untracked", &untracked,
			N_("search in both tracked and untracked files")),
		OPT_SET_INT(0, "exclude-standard", &opt_exclude,
			    N_("ignore files specified via '.gitignore'"), 1),
		OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
			 N_("recursively search in each submodule")),
		OPT_GROUP(""),
		OPT_BOOL('v', "invert-match", &opt.invert,
			N_("show non-matching lines")),
		OPT_BOOL('i', "ignore-case", &opt.ignore_case,
			N_("case insensitive matching")),
		OPT_BOOL('w', "word-regexp", &opt.word_regexp,
			N_("match patterns only at word boundaries")),
		OPT_SET_INT('a', "text", &opt.binary,
			N_("process binary files as text"), GREP_BINARY_TEXT),
		OPT_SET_INT('I', NULL, &opt.binary,
			N_("don't match patterns in binary files"),
			GREP_BINARY_NOMATCH),
		OPT_BOOL(0, "textconv", &opt.allow_textconv,
			 N_("process binary files with textconv filters")),
		OPT_SET_INT('r', "recursive", &opt.max_depth,
			    N_("search in subdirectories (default)"), -1),
		{ OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
			N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
			NULL, 1 },
		OPT_GROUP(""),
		OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
			    N_("use extended POSIX regular expressions"),
			    GREP_PATTERN_TYPE_ERE),
		OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
			    N_("use basic POSIX regular expressions (default)"),
			    GREP_PATTERN_TYPE_BRE),
		OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
			    N_("interpret patterns as fixed strings"),
			    GREP_PATTERN_TYPE_FIXED),
		OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
			    N_("use Perl-compatible regular expressions"),
			    GREP_PATTERN_TYPE_PCRE),
		OPT_GROUP(""),
		OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
		OPT_BOOL(0, "column", &opt.columnnum, N_("show column number of first match")),
		OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
		OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
		OPT_NEGBIT(0, "full-name", &opt.relative,
			N_("show filenames relative to top directory"), 1),
		OPT_BOOL('l', "files-with-matches", &opt.name_only,
			N_("show only filenames instead of matching lines")),
		OPT_BOOL(0, "name-only", &opt.name_only,
			N_("synonym for --files-with-matches")),
		OPT_BOOL('L', "files-without-match",
			&opt.unmatch_name_only,
			N_("show only the names of files without match")),
		OPT_BOOL_F('z', "null", &opt.null_following_name,
			   N_("print NUL after filenames"),
			   PARSE_OPT_NOCOMPLETE),
		OPT_BOOL('o', "only-matching", &opt.only_matching,
			N_("show only matching parts of a line")),
		OPT_BOOL('c', "count", &opt.count,
			N_("show the number of matches instead of matching lines")),
		OPT__COLOR(&opt.color, N_("highlight matches")),
		OPT_BOOL(0, "break", &opt.file_break,
			N_("print empty line between matches from different files")),
		OPT_BOOL(0, "heading", &opt.heading,
			N_("show filename only once above matches from same file")),
		OPT_GROUP(""),
		OPT_CALLBACK('C', "context", &opt, N_("n"),
			N_("show <n> context lines before and after matches"),
			context_callback),
		OPT_INTEGER('B', "before-context", &opt.pre_context,
			N_("show <n> context lines before matches")),
		OPT_INTEGER('A', "after-context", &opt.post_context,
			N_("show <n> context lines after matches")),
		OPT_INTEGER(0, "threads", &num_threads,
			N_("use <n> worker threads")),
		OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
			context_callback),
		OPT_BOOL('p', "show-function", &opt.funcname,
			N_("show a line with the function name before matches")),
		OPT_BOOL('W', "function-context", &opt.funcbody,
			N_("show the surrounding function")),
		OPT_GROUP(""),
		OPT_CALLBACK('f', NULL, &opt, N_("file"),
			N_("read patterns from file"), file_callback),
		{ OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
			N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
		{ OPTION_CALLBACK, 0, "and", &opt, NULL,
		  N_("combine patterns specified with -e"),
		  PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
		OPT_BOOL(0, "or", &dummy, ""),
		{ OPTION_CALLBACK, 0, "not", &opt, NULL, "",
		  PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
		{ OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
		  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
		  open_callback },
		{ OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
		  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
		  close_callback },
		OPT__QUIET(&opt.status_only,
			   N_("indicate hit with exit status without output")),
		OPT_BOOL(0, "all-match", &opt.all_match,
			N_("show only matches from files that match all patterns")),
		OPT_SET_INT_F(0, "debug", &opt.debug,
			      N_("show parse tree for grep expression"),
			      1, PARSE_OPT_HIDDEN),
		OPT_GROUP(""),
		{ OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
			N_("pager"), N_("show matching files in the pager"),
			PARSE_OPT_OPTARG | PARSE_OPT_NOCOMPLETE,
			NULL, (intptr_t)default_pager },
		OPT_BOOL_F(0, "ext-grep", &external_grep_allowed__ignored,
			   N_("allow calling of grep(1) (ignored by this build)"),
			   PARSE_OPT_NOCOMPLETE),
		OPT_END()
	};
 
	init_grep_defaults(the_repository);
	git_config(grep_cmd_config, NULL);
	grep_init(&opt, the_repository, prefix);
 
	/*
	 * If there is no -- then the paths must exist in the working
	 * tree.  If there is no explicit pattern specified with -e or
	 * -f, we take the first unrecognized non option to be the
	 * pattern, but then what follows it must be zero or more
	 * valid refs up to the -- (if exists), and then existing
	 * paths.  If there is an explicit pattern, then the first
	 * unrecognized non option is the beginning of the refs list
	 * that continues up to the -- (if exists), and then paths.
	 */
	argc = parse_options(argc, argv, prefix, options, grep_usage,
			     PARSE_OPT_KEEP_DASHDASH |
			     PARSE_OPT_STOP_AT_NON_OPTION);
	grep_commit_pattern_type(pattern_type_arg, &opt);
 
	if (use_index && !startup_info->have_repository) {
		int fallback = 0;
		git_config_get_bool("grep.fallbacktonoindex", &fallback);
		if (fallback)
			use_index = 0;
		else
			/* die the same way as if we did it at the beginning */
			setup_git_directory();
	}
 
	/*
	 * skip a -- separator; we know it cannot be
	 * separating revisions from pathnames if
	 * we haven't even had any patterns yet
	 */
	if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
		argv++;
		argc--;
	}
 
	/* First unrecognized non-option token */
	if (argc > 0 && !opt.pattern_list) {
		append_grep_pattern(&opt, argv[0], "command line", 0,
				    GREP_PATTERN);
		argv++;
		argc--;
	}
 
	if (show_in_pager == default_pager)
		show_in_pager = git_pager(1);
	if (show_in_pager) {
		opt.color = 0;
		opt.name_only = 1;
		opt.null_following_name = 1;
		opt.output_priv = &path_list;
		opt.output = append_path;
		string_list_append(&path_list, show_in_pager);
	}
 
	if (!opt.pattern_list)
		die(_("no pattern given"));
 
	/* --only-matching has no effect with --invert. */
	if (opt.invert)
		opt.only_matching = 0;
 
	/*
	 * We have to find "--" in a separate pass, because its presence
	 * influences how we will parse arguments that come before it.
	 */
	for (i = 0; i < argc; i++) {
		if (!strcmp(argv[i], "--")) {
			seen_dashdash = 1;
			break;
		}
	}
 
	/*
	 * Resolve any rev arguments. If we have a dashdash, then everything up
	 * to it must resolve as a rev. If not, then we stop at the first
	 * non-rev and assume everything else is a path.
	 */
	allow_revs = use_index && !untracked;
	for (i = 0; i < argc; i++) {
		const char *arg = argv[i];
		struct object_id oid;
		struct object_context oc;
		struct object *object;
 
		if (!strcmp(arg, "--")) {
			i++;
			break;
		}
 
		if (!allow_revs) {
			if (seen_dashdash)
				die(_("--no-index or --untracked cannot be used with revs"));
			break;
		}
 
		if (get_oid_with_context(the_repository, arg,
					 GET_OID_RECORD_PATH,
					 &oid, &oc)) {
			if (seen_dashdash)
				die(_("unable to resolve revision: %s"), arg);
			break;
		}
 
		object = parse_object_or_die(&oid, arg);
		if (!seen_dashdash)
			verify_non_filename(prefix, arg);
		add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
		free(oc.path);
	}
 
	/*
	 * Anything left over is presumed to be a path. But in the non-dashdash
	 * "do what I mean" case, we verify and complain when that isn't true.
	 */
	if (!seen_dashdash) {
		int j;
		for (j = i; j < argc; j++)
			verify_filename(prefix, argv[j], j == i && allow_revs);
	}
 
	parse_pathspec(&pathspec, 0,
		       PATHSPEC_PREFER_CWD |
		       (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
		       prefix, argv + i);
	pathspec.max_depth = opt.max_depth;
	pathspec.recursive = 1;
	pathspec.recurse_submodules = !!recurse_submodules;
 
	if (list.nr || cached || show_in_pager) {
		if (num_threads > 1)
			warning(_("invalid option combination, ignoring --threads"));
		num_threads = 1;
	} else if (!HAVE_THREADS && num_threads > 1) {
		warning(_("no threads support, ignoring --threads"));
		num_threads = 1;
	} else if (num_threads < 0)
		die(_("invalid number of threads specified (%d)"), num_threads);
	else if (num_threads == 0)
		num_threads = HAVE_THREADS ? GREP_NUM_THREADS_DEFAULT : 1;
 
	if (num_threads > 1) {
		if (!HAVE_THREADS)
			BUG("Somebody got num_threads calculation wrong!");
		if (!(opt.name_only || opt.unmatch_name_only || opt.count)
		    && (opt.pre_context || opt.post_context ||
			opt.file_break || opt.funcbody))
			skip_first_line = 1;
		start_threads(&opt);
	} else {
		/*
		 * The compiled patterns on the main path are only
		 * used when not using threading. Otherwise
		 * start_threads() above calls compile_grep_patterns()
		 * for each thread.
		 */
		compile_grep_patterns(&opt);
	}
 
	if (show_in_pager && (cached || list.nr))
		die(_("--open-files-in-pager only works on the worktree"));
 
	if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
		const char *pager = path_list.items[0].string;
		int len = strlen(pager);
 
		if (len > 4 && is_dir_sep(pager[len - 5]))
			pager += len - 4;
 
		if (opt.ignore_case && !strcmp("less", pager))
			string_list_append(&path_list, "-I");
 
		if (!strcmp("less", pager) || !strcmp("vi", pager)) {
			struct strbuf buf = STRBUF_INIT;
			strbuf_addf(&buf, "+/%s%s",
					strcmp("less", pager) ? "" : "*",
					opt.pattern_list->pattern);
			string_list_append(&path_list, buf.buf);
			strbuf_detach(&buf, NULL);
		}
	}
 
	if (recurse_submodules && (!use_index || untracked))
		die(_("option not supported with --recurse-submodules"));
 
	if (!show_in_pager && !opt.status_only)
		setup_pager();
 
	if (!use_index && (untracked || cached))
		die(_("--cached or --untracked cannot be used with --no-index"));
 
	if (!use_index || untracked) {
		int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
		hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
	} else if (0 <= opt_exclude) {
		die(_("--[no-]exclude-standard cannot be used for tracked contents"));
	} else if (!list.nr) {
		if (!cached)
			setup_work_tree();
 
		hit = grep_cache(&opt, &pathspec, cached);
	} else {
		if (cached)
			die(_("both --cached and trees are given"));
 
		hit = grep_objects(&opt, &pathspec, &list);
	}
 
	if (num_threads > 1)
		hit |= wait_all();
	if (hit && show_in_pager)
		run_pager(&opt, prefix);
	clear_pathspec(&pathspec);
	free_grep_patterns(&opt);
	return !hit;
}