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