Document the underlying protocol used by shallow repositories and --depth commands.
[git] / builtin / grep.c
1 /*
2  * Builtin "git grep"
3  *
4  * Copyright (c) 2006 Junio C Hamano
5  */
6 #include "cache.h"
7 #include "blob.h"
8 #include "tree.h"
9 #include "commit.h"
10 #include "tag.h"
11 #include "tree-walk.h"
12 #include "builtin.h"
13 #include "parse-options.h"
14 #include "string-list.h"
15 #include "run-command.h"
16 #include "userdiff.h"
17 #include "grep.h"
18 #include "quote.h"
19 #include "dir.h"
20 #include "thread-utils.h"
21
22 static char const * const grep_usage[] = {
23         "git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]",
24         NULL
25 };
26
27 static int use_threads = 1;
28
29 #ifndef NO_PTHREADS
30 #define THREADS 8
31 static pthread_t threads[THREADS];
32
33 static void *load_sha1(const unsigned char *sha1, unsigned long *size,
34                        const char *name);
35 static void *load_file(const char *filename, size_t *sz);
36
37 enum work_type {WORK_SHA1, WORK_FILE};
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         enum work_type type;
45         char *name;
46
47         /* if type == WORK_SHA1, then 'identifier' is a SHA1,
48          * otherwise type == WORK_FILE, and 'identifier' is a NUL
49          * terminated filename.
50          */
51         void *identifier;
52         char done;
53         struct strbuf out;
54 };
55
56 /* In the range [todo_done, todo_start) in 'todo' we have work_items
57  * that have been or are processed by a consumer thread. We haven't
58  * written the result for these to stdout yet.
59  *
60  * The work_items in [todo_start, todo_end) are waiting to be picked
61  * up by a consumer thread.
62  *
63  * The ranges are modulo TODO_SIZE.
64  */
65 #define TODO_SIZE 128
66 static struct work_item todo[TODO_SIZE];
67 static int todo_start;
68 static int todo_end;
69 static int todo_done;
70
71 /* Has all work items been added? */
72 static int all_work_added;
73
74 /* This lock protects all the variables above. */
75 static pthread_mutex_t grep_mutex;
76
77 /* Used to serialize calls to read_sha1_file. */
78 static pthread_mutex_t read_sha1_mutex;
79
80 #define grep_lock() pthread_mutex_lock(&grep_mutex)
81 #define grep_unlock() pthread_mutex_unlock(&grep_mutex)
82 #define read_sha1_lock() pthread_mutex_lock(&read_sha1_mutex)
83 #define read_sha1_unlock() pthread_mutex_unlock(&read_sha1_mutex)
84
85 /* Signalled when a new work_item is added to todo. */
86 static pthread_cond_t cond_add;
87
88 /* Signalled when the result from one work_item is written to
89  * stdout.
90  */
91 static pthread_cond_t cond_write;
92
93 /* Signalled when we are finished with everything. */
94 static pthread_cond_t cond_result;
95
96 static int print_hunk_marks_between_files;
97 static int printed_something;
98
99 static void add_work(enum work_type type, char *name, void *id)
100 {
101         grep_lock();
102
103         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
104                 pthread_cond_wait(&cond_write, &grep_mutex);
105         }
106
107         todo[todo_end].type = type;
108         todo[todo_end].name = name;
109         todo[todo_end].identifier = id;
110         todo[todo_end].done = 0;
111         strbuf_reset(&todo[todo_end].out);
112         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
113
114         pthread_cond_signal(&cond_add);
115         grep_unlock();
116 }
117
118 static struct work_item *get_work(void)
119 {
120         struct work_item *ret;
121
122         grep_lock();
123         while (todo_start == todo_end && !all_work_added) {
124                 pthread_cond_wait(&cond_add, &grep_mutex);
125         }
126
127         if (todo_start == todo_end && all_work_added) {
128                 ret = NULL;
129         } else {
130                 ret = &todo[todo_start];
131                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
132         }
133         grep_unlock();
134         return ret;
135 }
136
137 static void grep_sha1_async(struct grep_opt *opt, char *name,
138                             const unsigned char *sha1)
139 {
140         unsigned char *s;
141         s = xmalloc(20);
142         memcpy(s, sha1, 20);
143         add_work(WORK_SHA1, name, s);
144 }
145
146 static void grep_file_async(struct grep_opt *opt, char *name,
147                             const char *filename)
148 {
149         add_work(WORK_FILE, name, xstrdup(filename));
150 }
151
152 static void work_done(struct work_item *w)
153 {
154         int old_done;
155
156         grep_lock();
157         w->done = 1;
158         old_done = todo_done;
159         for(; todo[todo_done].done && todo_done != todo_start;
160             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
161                 w = &todo[todo_done];
162                 if (w->out.len) {
163                         if (print_hunk_marks_between_files && printed_something)
164                                 write_or_die(1, "--\n", 3);
165                         write_or_die(1, w->out.buf, w->out.len);
166                         printed_something = 1;
167                 }
168                 free(w->name);
169                 free(w->identifier);
170         }
171
172         if (old_done != todo_done)
173                 pthread_cond_signal(&cond_write);
174
175         if (all_work_added && todo_done == todo_end)
176                 pthread_cond_signal(&cond_result);
177
178         grep_unlock();
179 }
180
181 static void *run(void *arg)
182 {
183         int hit = 0;
184         struct grep_opt *opt = arg;
185
186         while (1) {
187                 struct work_item *w = get_work();
188                 if (!w)
189                         break;
190
191                 opt->output_priv = w;
192                 if (w->type == WORK_SHA1) {
193                         unsigned long sz;
194                         void* data = load_sha1(w->identifier, &sz, w->name);
195
196                         if (data) {
197                                 hit |= grep_buffer(opt, w->name, data, sz);
198                                 free(data);
199                         }
200                 } else if (w->type == WORK_FILE) {
201                         size_t sz;
202                         void* data = load_file(w->identifier, &sz);
203                         if (data) {
204                                 hit |= grep_buffer(opt, w->name, data, sz);
205                                 free(data);
206                         }
207                 } else {
208                         assert(0);
209                 }
210
211                 work_done(w);
212         }
213         free_grep_patterns(arg);
214         free(arg);
215
216         return (void*) (intptr_t) hit;
217 }
218
219 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
220 {
221         struct work_item *w = opt->output_priv;
222         strbuf_add(&w->out, buf, size);
223 }
224
225 static void start_threads(struct grep_opt *opt)
226 {
227         int i;
228
229         pthread_mutex_init(&grep_mutex, NULL);
230         pthread_mutex_init(&read_sha1_mutex, NULL);
231         pthread_cond_init(&cond_add, NULL);
232         pthread_cond_init(&cond_write, NULL);
233         pthread_cond_init(&cond_result, NULL);
234
235         for (i = 0; i < ARRAY_SIZE(todo); i++) {
236                 strbuf_init(&todo[i].out, 0);
237         }
238
239         for (i = 0; i < ARRAY_SIZE(threads); i++) {
240                 int err;
241                 struct grep_opt *o = grep_opt_dup(opt);
242                 o->output = strbuf_out;
243                 compile_grep_patterns(o);
244                 err = pthread_create(&threads[i], NULL, run, o);
245
246                 if (err)
247                         die(_("grep: failed to create thread: %s"),
248                             strerror(err));
249         }
250 }
251
252 static int wait_all(void)
253 {
254         int hit = 0;
255         int i;
256
257         grep_lock();
258         all_work_added = 1;
259
260         /* Wait until all work is done. */
261         while (todo_done != todo_end)
262                 pthread_cond_wait(&cond_result, &grep_mutex);
263
264         /* Wake up all the consumer threads so they can see that there
265          * is no more work to do.
266          */
267         pthread_cond_broadcast(&cond_add);
268         grep_unlock();
269
270         for (i = 0; i < ARRAY_SIZE(threads); i++) {
271                 void *h;
272                 pthread_join(threads[i], &h);
273                 hit |= (int) (intptr_t) h;
274         }
275
276         pthread_mutex_destroy(&grep_mutex);
277         pthread_mutex_destroy(&read_sha1_mutex);
278         pthread_cond_destroy(&cond_add);
279         pthread_cond_destroy(&cond_write);
280         pthread_cond_destroy(&cond_result);
281
282         return hit;
283 }
284 #else /* !NO_PTHREADS */
285 #define read_sha1_lock()
286 #define read_sha1_unlock()
287
288 static int wait_all(void)
289 {
290         return 0;
291 }
292 #endif
293
294 static int grep_config(const char *var, const char *value, void *cb)
295 {
296         struct grep_opt *opt = cb;
297         char *color = NULL;
298
299         switch (userdiff_config(var, value)) {
300         case 0: break;
301         case -1: return -1;
302         default: return 0;
303         }
304
305         if (!strcmp(var, "grep.extendedregexp")) {
306                 if (git_config_bool(var, value))
307                         opt->regflags |= REG_EXTENDED;
308                 else
309                         opt->regflags &= ~REG_EXTENDED;
310                 return 0;
311         }
312
313         if (!strcmp(var, "grep.linenumber")) {
314                 opt->linenum = git_config_bool(var, value);
315                 return 0;
316         }
317
318         if (!strcmp(var, "color.grep"))
319                 opt->color = git_config_colorbool(var, value, -1);
320         else if (!strcmp(var, "color.grep.context"))
321                 color = opt->color_context;
322         else if (!strcmp(var, "color.grep.filename"))
323                 color = opt->color_filename;
324         else if (!strcmp(var, "color.grep.function"))
325                 color = opt->color_function;
326         else if (!strcmp(var, "color.grep.linenumber"))
327                 color = opt->color_lineno;
328         else if (!strcmp(var, "color.grep.match"))
329                 color = opt->color_match;
330         else if (!strcmp(var, "color.grep.selected"))
331                 color = opt->color_selected;
332         else if (!strcmp(var, "color.grep.separator"))
333                 color = opt->color_sep;
334         else
335                 return git_color_default_config(var, value, cb);
336         if (color) {
337                 if (!value)
338                         return config_error_nonbool(var);
339                 color_parse(value, var, color);
340         }
341         return 0;
342 }
343
344 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
345 {
346         void *data;
347
348         if (use_threads) {
349                 read_sha1_lock();
350                 data = read_sha1_file(sha1, type, size);
351                 read_sha1_unlock();
352         } else {
353                 data = read_sha1_file(sha1, type, size);
354         }
355         return data;
356 }
357
358 static void *load_sha1(const unsigned char *sha1, unsigned long *size,
359                        const char *name)
360 {
361         enum object_type type;
362         void *data = lock_and_read_sha1_file(sha1, &type, size);
363
364         if (!data)
365                 error(_("'%s': unable to read %s"), name, sha1_to_hex(sha1));
366
367         return data;
368 }
369
370 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
371                      const char *filename, int tree_name_len)
372 {
373         struct strbuf pathbuf = STRBUF_INIT;
374         char *name;
375
376         if (opt->relative && opt->prefix_length) {
377                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
378                                     opt->prefix);
379                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
380         } else {
381                 strbuf_addstr(&pathbuf, filename);
382         }
383
384         name = strbuf_detach(&pathbuf, NULL);
385
386 #ifndef NO_PTHREADS
387         if (use_threads) {
388                 grep_sha1_async(opt, name, sha1);
389                 return 0;
390         } else
391 #endif
392         {
393                 int hit;
394                 unsigned long sz;
395                 void *data = load_sha1(sha1, &sz, name);
396                 if (!data)
397                         hit = 0;
398                 else
399                         hit = grep_buffer(opt, name, data, sz);
400
401                 free(data);
402                 free(name);
403                 return hit;
404         }
405 }
406
407 static void *load_file(const char *filename, size_t *sz)
408 {
409         struct stat st;
410         char *data;
411         int i;
412
413         if (lstat(filename, &st) < 0) {
414         err_ret:
415                 if (errno != ENOENT)
416                         error(_("'%s': %s"), filename, strerror(errno));
417                 return NULL;
418         }
419         if (!S_ISREG(st.st_mode))
420                 return NULL;
421         *sz = xsize_t(st.st_size);
422         i = open(filename, O_RDONLY);
423         if (i < 0)
424                 goto err_ret;
425         data = xmalloc(*sz + 1);
426         if (st.st_size != read_in_full(i, data, *sz)) {
427                 error(_("'%s': short read %s"), filename, strerror(errno));
428                 close(i);
429                 free(data);
430                 return NULL;
431         }
432         close(i);
433         data[*sz] = 0;
434         return data;
435 }
436
437 static int grep_file(struct grep_opt *opt, const char *filename)
438 {
439         struct strbuf buf = STRBUF_INIT;
440         char *name;
441
442         if (opt->relative && opt->prefix_length)
443                 quote_path_relative(filename, -1, &buf, opt->prefix);
444         else
445                 strbuf_addstr(&buf, filename);
446         name = strbuf_detach(&buf, NULL);
447
448 #ifndef NO_PTHREADS
449         if (use_threads) {
450                 grep_file_async(opt, name, filename);
451                 return 0;
452         } else
453 #endif
454         {
455                 int hit;
456                 size_t sz;
457                 void *data = load_file(filename, &sz);
458                 if (!data)
459                         hit = 0;
460                 else
461                         hit = grep_buffer(opt, name, data, sz);
462
463                 free(data);
464                 free(name);
465                 return hit;
466         }
467 }
468
469 static void append_path(struct grep_opt *opt, const void *data, size_t len)
470 {
471         struct string_list *path_list = opt->output_priv;
472
473         if (len == 1 && *(const char *)data == '\0')
474                 return;
475         string_list_append(path_list, xstrndup(data, len));
476 }
477
478 static void run_pager(struct grep_opt *opt, const char *prefix)
479 {
480         struct string_list *path_list = opt->output_priv;
481         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
482         int i, status;
483
484         for (i = 0; i < path_list->nr; i++)
485                 argv[i] = path_list->items[i].string;
486         argv[path_list->nr] = NULL;
487
488         if (prefix && chdir(prefix))
489                 die(_("Failed to chdir: %s"), prefix);
490         status = run_command_v_opt(argv, RUN_USING_SHELL);
491         if (status)
492                 exit(status);
493         free(argv);
494 }
495
496 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
497 {
498         int hit = 0;
499         int nr;
500         read_cache();
501
502         for (nr = 0; nr < active_nr; nr++) {
503                 struct cache_entry *ce = active_cache[nr];
504                 if (!S_ISREG(ce->ce_mode))
505                         continue;
506                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
507                         continue;
508                 /*
509                  * If CE_VALID is on, we assume worktree file and its cache entry
510                  * are identical, even if worktree file has been modified, so use
511                  * cache version instead
512                  */
513                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
514                         if (ce_stage(ce))
515                                 continue;
516                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
517                 }
518                 else
519                         hit |= grep_file(opt, ce->name);
520                 if (ce_stage(ce)) {
521                         do {
522                                 nr++;
523                         } while (nr < active_nr &&
524                                  !strcmp(ce->name, active_cache[nr]->name));
525                         nr--; /* compensate for loop control */
526                 }
527                 if (hit && opt->status_only)
528                         break;
529         }
530         return hit;
531 }
532
533 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
534                      struct tree_desc *tree, struct strbuf *base, int tn_len)
535 {
536         int hit = 0, matched = 0;
537         struct name_entry entry;
538         int old_baselen = base->len;
539
540         while (tree_entry(tree, &entry)) {
541                 int te_len = tree_entry_len(entry.path, entry.sha1);
542
543                 if (matched != 2) {
544                         matched = tree_entry_interesting(&entry, base, tn_len, pathspec);
545                         if (matched == -1)
546                                 break; /* no more matches */
547                         if (!matched)
548                                 continue;
549                 }
550
551                 strbuf_add(base, entry.path, te_len);
552
553                 if (S_ISREG(entry.mode)) {
554                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
555                 }
556                 else if (S_ISDIR(entry.mode)) {
557                         enum object_type type;
558                         struct tree_desc sub;
559                         void *data;
560                         unsigned long size;
561
562                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
563                         if (!data)
564                                 die(_("unable to read tree (%s)"),
565                                     sha1_to_hex(entry.sha1));
566
567                         strbuf_addch(base, '/');
568                         init_tree_desc(&sub, data, size);
569                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
570                         free(data);
571                 }
572                 strbuf_setlen(base, old_baselen);
573
574                 if (hit && opt->status_only)
575                         break;
576         }
577         return hit;
578 }
579
580 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
581                        struct object *obj, const char *name)
582 {
583         if (obj->type == OBJ_BLOB)
584                 return grep_sha1(opt, obj->sha1, name, 0);
585         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
586                 struct tree_desc tree;
587                 void *data;
588                 unsigned long size;
589                 struct strbuf base;
590                 int hit, len;
591
592                 data = read_object_with_reference(obj->sha1, tree_type,
593                                                   &size, NULL);
594                 if (!data)
595                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
596
597                 len = name ? strlen(name) : 0;
598                 strbuf_init(&base, PATH_MAX + len + 1);
599                 if (len) {
600                         strbuf_add(&base, name, len);
601                         strbuf_addch(&base, ':');
602                 }
603                 init_tree_desc(&tree, data, size);
604                 hit = grep_tree(opt, pathspec, &tree, &base, base.len);
605                 strbuf_release(&base);
606                 free(data);
607                 return hit;
608         }
609         die(_("unable to grep from object of type %s"), typename(obj->type));
610 }
611
612 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
613                         const struct object_array *list)
614 {
615         unsigned int i;
616         int hit = 0;
617         const unsigned int nr = list->nr;
618
619         for (i = 0; i < nr; i++) {
620                 struct object *real_obj;
621                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
622                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
623                         hit = 1;
624                         if (opt->status_only)
625                                 break;
626                 }
627         }
628         return hit;
629 }
630
631 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec)
632 {
633         struct dir_struct dir;
634         int i, hit = 0;
635
636         memset(&dir, 0, sizeof(dir));
637         setup_standard_excludes(&dir);
638
639         fill_directory(&dir, pathspec->raw);
640         for (i = 0; i < dir.nr; i++) {
641                 const char *name = dir.entries[i]->name;
642                 int namelen = strlen(name);
643                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
644                         continue;
645                 hit |= grep_file(opt, dir.entries[i]->name);
646                 if (hit && opt->status_only)
647                         break;
648         }
649         return hit;
650 }
651
652 static int context_callback(const struct option *opt, const char *arg,
653                             int unset)
654 {
655         struct grep_opt *grep_opt = opt->value;
656         int value;
657         const char *endp;
658
659         if (unset) {
660                 grep_opt->pre_context = grep_opt->post_context = 0;
661                 return 0;
662         }
663         value = strtol(arg, (char **)&endp, 10);
664         if (*endp) {
665                 return error(_("switch `%c' expects a numerical value"),
666                              opt->short_name);
667         }
668         grep_opt->pre_context = grep_opt->post_context = value;
669         return 0;
670 }
671
672 static int file_callback(const struct option *opt, const char *arg, int unset)
673 {
674         struct grep_opt *grep_opt = opt->value;
675         int from_stdin = !strcmp(arg, "-");
676         FILE *patterns;
677         int lno = 0;
678         struct strbuf sb = STRBUF_INIT;
679
680         patterns = from_stdin ? stdin : fopen(arg, "r");
681         if (!patterns)
682                 die_errno(_("cannot open '%s'"), arg);
683         while (strbuf_getline(&sb, patterns, '\n') == 0) {
684                 char *s;
685                 size_t len;
686
687                 /* ignore empty line like grep does */
688                 if (sb.len == 0)
689                         continue;
690
691                 s = strbuf_detach(&sb, &len);
692                 append_grep_pat(grep_opt, s, len, arg, ++lno, GREP_PATTERN);
693         }
694         if (!from_stdin)
695                 fclose(patterns);
696         strbuf_release(&sb);
697         return 0;
698 }
699
700 static int not_callback(const struct option *opt, const char *arg, int unset)
701 {
702         struct grep_opt *grep_opt = opt->value;
703         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
704         return 0;
705 }
706
707 static int and_callback(const struct option *opt, const char *arg, int unset)
708 {
709         struct grep_opt *grep_opt = opt->value;
710         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
711         return 0;
712 }
713
714 static int open_callback(const struct option *opt, const char *arg, int unset)
715 {
716         struct grep_opt *grep_opt = opt->value;
717         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
718         return 0;
719 }
720
721 static int close_callback(const struct option *opt, const char *arg, int unset)
722 {
723         struct grep_opt *grep_opt = opt->value;
724         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
725         return 0;
726 }
727
728 static int pattern_callback(const struct option *opt, const char *arg,
729                             int unset)
730 {
731         struct grep_opt *grep_opt = opt->value;
732         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
733         return 0;
734 }
735
736 static int help_callback(const struct option *opt, const char *arg, int unset)
737 {
738         return -1;
739 }
740
741 int cmd_grep(int argc, const char **argv, const char *prefix)
742 {
743         int hit = 0;
744         int cached = 0;
745         int seen_dashdash = 0;
746         int external_grep_allowed__ignored;
747         const char *show_in_pager = NULL, *default_pager = "dummy";
748         struct grep_opt opt;
749         struct object_array list = OBJECT_ARRAY_INIT;
750         const char **paths = NULL;
751         struct pathspec pathspec;
752         struct string_list path_list = STRING_LIST_INIT_NODUP;
753         int i;
754         int dummy;
755         int use_index = 1;
756         struct option options[] = {
757                 OPT_BOOLEAN(0, "cached", &cached,
758                         "search in index instead of in the work tree"),
759                 OPT_BOOLEAN(0, "index", &use_index,
760                         "--no-index finds in contents not managed by git"),
761                 OPT_GROUP(""),
762                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
763                         "show non-matching lines"),
764                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
765                         "case insensitive matching"),
766                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
767                         "match patterns only at word boundaries"),
768                 OPT_SET_INT('a', "text", &opt.binary,
769                         "process binary files as text", GREP_BINARY_TEXT),
770                 OPT_SET_INT('I', NULL, &opt.binary,
771                         "don't match patterns in binary files",
772                         GREP_BINARY_NOMATCH),
773                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
774                         "descend at most <depth> levels", PARSE_OPT_NONEG,
775                         NULL, 1 },
776                 OPT_GROUP(""),
777                 OPT_BIT('E', "extended-regexp", &opt.regflags,
778                         "use extended POSIX regular expressions", REG_EXTENDED),
779                 OPT_NEGBIT('G', "basic-regexp", &opt.regflags,
780                         "use basic POSIX regular expressions (default)",
781                         REG_EXTENDED),
782                 OPT_BOOLEAN('F', "fixed-strings", &opt.fixed,
783                         "interpret patterns as fixed strings"),
784                 OPT_GROUP(""),
785                 OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
786                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
787                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
788                 OPT_NEGBIT(0, "full-name", &opt.relative,
789                         "show filenames relative to top directory", 1),
790                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
791                         "show only filenames instead of matching lines"),
792                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
793                         "synonym for --files-with-matches"),
794                 OPT_BOOLEAN('L', "files-without-match",
795                         &opt.unmatch_name_only,
796                         "show only the names of files without match"),
797                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
798                         "print NUL after filenames"),
799                 OPT_BOOLEAN('c', "count", &opt.count,
800                         "show the number of matches instead of matching lines"),
801                 OPT__COLOR(&opt.color, "highlight matches"),
802                 OPT_GROUP(""),
803                 OPT_CALLBACK('C', NULL, &opt, "n",
804                         "show <n> context lines before and after matches",
805                         context_callback),
806                 OPT_INTEGER('B', NULL, &opt.pre_context,
807                         "show <n> context lines before matches"),
808                 OPT_INTEGER('A', NULL, &opt.post_context,
809                         "show <n> context lines after matches"),
810                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
811                         context_callback),
812                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
813                         "show a line with the function name before matches"),
814                 OPT_GROUP(""),
815                 OPT_CALLBACK('f', NULL, &opt, "file",
816                         "read patterns from file", file_callback),
817                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
818                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
819                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
820                   "combine patterns specified with -e",
821                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
822                 OPT_BOOLEAN(0, "or", &dummy, ""),
823                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
824                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
825                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
826                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
827                   open_callback },
828                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
829                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
830                   close_callback },
831                 OPT__QUIET(&opt.status_only,
832                            "indicate hit with exit status without output"),
833                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
834                         "show only matches from files that match all patterns"),
835                 OPT_GROUP(""),
836                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
837                         "pager", "show matching files in the pager",
838                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
839                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
840                             "allow calling of grep(1) (ignored by this build)"),
841                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
842                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
843                 OPT_END()
844         };
845
846         /*
847          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
848          * to show usage information and exit.
849          */
850         if (argc == 2 && !strcmp(argv[1], "-h"))
851                 usage_with_options(grep_usage, options);
852
853         memset(&opt, 0, sizeof(opt));
854         opt.prefix = prefix;
855         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
856         opt.relative = 1;
857         opt.pathname = 1;
858         opt.pattern_tail = &opt.pattern_list;
859         opt.header_tail = &opt.header_list;
860         opt.regflags = REG_NEWLINE;
861         opt.max_depth = -1;
862
863         strcpy(opt.color_context, "");
864         strcpy(opt.color_filename, "");
865         strcpy(opt.color_function, "");
866         strcpy(opt.color_lineno, "");
867         strcpy(opt.color_match, GIT_COLOR_BOLD_RED);
868         strcpy(opt.color_selected, "");
869         strcpy(opt.color_sep, GIT_COLOR_CYAN);
870         opt.color = -1;
871         git_config(grep_config, &opt);
872         if (opt.color == -1)
873                 opt.color = git_use_color_default;
874
875         /*
876          * If there is no -- then the paths must exist in the working
877          * tree.  If there is no explicit pattern specified with -e or
878          * -f, we take the first unrecognized non option to be the
879          * pattern, but then what follows it must be zero or more
880          * valid refs up to the -- (if exists), and then existing
881          * paths.  If there is an explicit pattern, then the first
882          * unrecognized non option is the beginning of the refs list
883          * that continues up to the -- (if exists), and then paths.
884          */
885         argc = parse_options(argc, argv, prefix, options, grep_usage,
886                              PARSE_OPT_KEEP_DASHDASH |
887                              PARSE_OPT_STOP_AT_NON_OPTION |
888                              PARSE_OPT_NO_INTERNAL_HELP);
889
890         if (use_index && !startup_info->have_repository)
891                 /* die the same way as if we did it at the beginning */
892                 setup_git_directory();
893
894         /*
895          * skip a -- separator; we know it cannot be
896          * separating revisions from pathnames if
897          * we haven't even had any patterns yet
898          */
899         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
900                 argv++;
901                 argc--;
902         }
903
904         /* First unrecognized non-option token */
905         if (argc > 0 && !opt.pattern_list) {
906                 append_grep_pattern(&opt, argv[0], "command line", 0,
907                                     GREP_PATTERN);
908                 argv++;
909                 argc--;
910         }
911
912         if (show_in_pager == default_pager)
913                 show_in_pager = git_pager(1);
914         if (show_in_pager) {
915                 opt.color = 0;
916                 opt.name_only = 1;
917                 opt.null_following_name = 1;
918                 opt.output_priv = &path_list;
919                 opt.output = append_path;
920                 string_list_append(&path_list, show_in_pager);
921                 use_threads = 0;
922         }
923
924         if (!opt.pattern_list)
925                 die(_("no pattern given."));
926         if (!opt.fixed && opt.ignore_case)
927                 opt.regflags |= REG_ICASE;
928         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
929                 die(_("cannot mix --fixed-strings and regexp"));
930
931 #ifndef NO_PTHREADS
932         if (online_cpus() == 1 || !grep_threads_ok(&opt))
933                 use_threads = 0;
934
935         if (use_threads) {
936                 if (opt.pre_context || opt.post_context)
937                         print_hunk_marks_between_files = 1;
938                 start_threads(&opt);
939         }
940 #else
941         use_threads = 0;
942 #endif
943
944         compile_grep_patterns(&opt);
945
946         /* Check revs and then paths */
947         for (i = 0; i < argc; i++) {
948                 const char *arg = argv[i];
949                 unsigned char sha1[20];
950                 /* Is it a rev? */
951                 if (!get_sha1(arg, sha1)) {
952                         struct object *object = parse_object(sha1);
953                         if (!object)
954                                 die(_("bad object %s"), arg);
955                         add_object_array(object, arg, &list);
956                         continue;
957                 }
958                 if (!strcmp(arg, "--")) {
959                         i++;
960                         seen_dashdash = 1;
961                 }
962                 break;
963         }
964
965         /* The rest are paths */
966         if (!seen_dashdash) {
967                 int j;
968                 for (j = i; j < argc; j++)
969                         verify_filename(prefix, argv[j]);
970         }
971
972         if (i < argc)
973                 paths = get_pathspec(prefix, argv + i);
974         else if (prefix) {
975                 paths = xcalloc(2, sizeof(const char *));
976                 paths[0] = prefix;
977                 paths[1] = NULL;
978         }
979         init_pathspec(&pathspec, paths);
980         pathspec.max_depth = opt.max_depth;
981         pathspec.recursive = 1;
982
983         if (show_in_pager && (cached || list.nr))
984                 die(_("--open-files-in-pager only works on the worktree"));
985
986         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
987                 const char *pager = path_list.items[0].string;
988                 int len = strlen(pager);
989
990                 if (len > 4 && is_dir_sep(pager[len - 5]))
991                         pager += len - 4;
992
993                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
994                         struct strbuf buf = STRBUF_INIT;
995                         strbuf_addf(&buf, "+/%s%s",
996                                         strcmp("less", pager) ? "" : "*",
997                                         opt.pattern_list->pattern);
998                         string_list_append(&path_list, buf.buf);
999                         strbuf_detach(&buf, NULL);
1000                 }
1001         }
1002
1003         if (!show_in_pager)
1004                 setup_pager();
1005
1006
1007         if (!use_index) {
1008                 if (cached)
1009                         die(_("--cached cannot be used with --no-index."));
1010                 if (list.nr)
1011                         die(_("--no-index cannot be used with revs."));
1012                 hit = grep_directory(&opt, &pathspec);
1013         } else if (!list.nr) {
1014                 if (!cached)
1015                         setup_work_tree();
1016
1017                 hit = grep_cache(&opt, &pathspec, cached);
1018         } else {
1019                 if (cached)
1020                         die(_("both --cached and trees are given."));
1021                 hit = grep_objects(&opt, &pathspec, &list);
1022         }
1023
1024         if (use_threads)
1025                 hit |= wait_all();
1026         if (hit && show_in_pager)
1027                 run_pager(&opt, prefix);
1028         free_grep_patterns(&opt);
1029         return !hit;
1030 }