Merge branch 'jc/maint-rev-list-topo-doc'
[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         "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 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, 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                 compile_grep_patterns(o);
213                 err = pthread_create(&threads[i], NULL, run, o);
214
215                 if (err)
216                         die(_("grep: failed to create thread: %s"),
217                             strerror(err));
218         }
219 }
220
221 static int wait_all(void)
222 {
223         int hit = 0;
224         int i;
225
226         grep_lock();
227         all_work_added = 1;
228
229         /* Wait until all work is done. */
230         while (todo_done != todo_end)
231                 pthread_cond_wait(&cond_result, &grep_mutex);
232
233         /* Wake up all the consumer threads so they can see that there
234          * is no more work to do.
235          */
236         pthread_cond_broadcast(&cond_add);
237         grep_unlock();
238
239         for (i = 0; i < ARRAY_SIZE(threads); i++) {
240                 void *h;
241                 pthread_join(threads[i], &h);
242                 hit |= (int) (intptr_t) h;
243         }
244
245         pthread_mutex_destroy(&grep_mutex);
246         pthread_mutex_destroy(&grep_read_mutex);
247         pthread_mutex_destroy(&grep_attr_mutex);
248         pthread_cond_destroy(&cond_add);
249         pthread_cond_destroy(&cond_write);
250         pthread_cond_destroy(&cond_result);
251         grep_use_locks = 0;
252
253         return hit;
254 }
255 #else /* !NO_PTHREADS */
256
257 static int wait_all(void)
258 {
259         return 0;
260 }
261 #endif
262
263 static int grep_config(const char *var, const char *value, void *cb)
264 {
265         struct grep_opt *opt = cb;
266         char *color = NULL;
267
268         if (userdiff_config(var, value) < 0)
269                 return -1;
270
271         if (!strcmp(var, "grep.extendedregexp")) {
272                 if (git_config_bool(var, value))
273                         opt->regflags |= REG_EXTENDED;
274                 else
275                         opt->regflags &= ~REG_EXTENDED;
276                 return 0;
277         }
278
279         if (!strcmp(var, "grep.linenumber")) {
280                 opt->linenum = git_config_bool(var, value);
281                 return 0;
282         }
283
284         if (!strcmp(var, "color.grep"))
285                 opt->color = git_config_colorbool(var, value);
286         else if (!strcmp(var, "color.grep.context"))
287                 color = opt->color_context;
288         else if (!strcmp(var, "color.grep.filename"))
289                 color = opt->color_filename;
290         else if (!strcmp(var, "color.grep.function"))
291                 color = opt->color_function;
292         else if (!strcmp(var, "color.grep.linenumber"))
293                 color = opt->color_lineno;
294         else if (!strcmp(var, "color.grep.match"))
295                 color = opt->color_match;
296         else if (!strcmp(var, "color.grep.selected"))
297                 color = opt->color_selected;
298         else if (!strcmp(var, "color.grep.separator"))
299                 color = opt->color_sep;
300         else
301                 return git_color_default_config(var, value, cb);
302         if (color) {
303                 if (!value)
304                         return config_error_nonbool(var);
305                 color_parse(value, var, color);
306         }
307         return 0;
308 }
309
310 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
311 {
312         void *data;
313
314         grep_read_lock();
315         data = read_sha1_file(sha1, type, size);
316         grep_read_unlock();
317         return data;
318 }
319
320 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
321                      const char *filename, int tree_name_len)
322 {
323         struct strbuf pathbuf = STRBUF_INIT;
324
325         if (opt->relative && opt->prefix_length) {
326                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
327                                     opt->prefix);
328                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
329         } else {
330                 strbuf_addstr(&pathbuf, filename);
331         }
332
333 #ifndef NO_PTHREADS
334         if (use_threads) {
335                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
336                 strbuf_release(&pathbuf);
337                 return 0;
338         } else
339 #endif
340         {
341                 struct grep_source gs;
342                 int hit;
343
344                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
345                 strbuf_release(&pathbuf);
346                 hit = grep_source(opt, &gs);
347
348                 grep_source_clear(&gs);
349                 return hit;
350         }
351 }
352
353 static int grep_file(struct grep_opt *opt, const char *filename)
354 {
355         struct strbuf buf = STRBUF_INIT;
356
357         if (opt->relative && opt->prefix_length)
358                 quote_path_relative(filename, -1, &buf, opt->prefix);
359         else
360                 strbuf_addstr(&buf, filename);
361
362 #ifndef NO_PTHREADS
363         if (use_threads) {
364                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename);
365                 strbuf_release(&buf);
366                 return 0;
367         } else
368 #endif
369         {
370                 struct grep_source gs;
371                 int hit;
372
373                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename);
374                 strbuf_release(&buf);
375                 hit = grep_source(opt, &gs);
376
377                 grep_source_clear(&gs);
378                 return hit;
379         }
380 }
381
382 static void append_path(struct grep_opt *opt, const void *data, size_t len)
383 {
384         struct string_list *path_list = opt->output_priv;
385
386         if (len == 1 && *(const char *)data == '\0')
387                 return;
388         string_list_append(path_list, xstrndup(data, len));
389 }
390
391 static void run_pager(struct grep_opt *opt, const char *prefix)
392 {
393         struct string_list *path_list = opt->output_priv;
394         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
395         int i, status;
396
397         for (i = 0; i < path_list->nr; i++)
398                 argv[i] = path_list->items[i].string;
399         argv[path_list->nr] = NULL;
400
401         if (prefix && chdir(prefix))
402                 die(_("Failed to chdir: %s"), prefix);
403         status = run_command_v_opt(argv, RUN_USING_SHELL);
404         if (status)
405                 exit(status);
406         free(argv);
407 }
408
409 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
410 {
411         int hit = 0;
412         int nr;
413         read_cache();
414
415         for (nr = 0; nr < active_nr; nr++) {
416                 struct cache_entry *ce = active_cache[nr];
417                 if (!S_ISREG(ce->ce_mode))
418                         continue;
419                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
420                         continue;
421                 /*
422                  * If CE_VALID is on, we assume worktree file and its cache entry
423                  * are identical, even if worktree file has been modified, so use
424                  * cache version instead
425                  */
426                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
427                         if (ce_stage(ce))
428                                 continue;
429                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
430                 }
431                 else
432                         hit |= grep_file(opt, ce->name);
433                 if (ce_stage(ce)) {
434                         do {
435                                 nr++;
436                         } while (nr < active_nr &&
437                                  !strcmp(ce->name, active_cache[nr]->name));
438                         nr--; /* compensate for loop control */
439                 }
440                 if (hit && opt->status_only)
441                         break;
442         }
443         return hit;
444 }
445
446 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
447                      struct tree_desc *tree, struct strbuf *base, int tn_len)
448 {
449         int hit = 0;
450         enum interesting match = entry_not_interesting;
451         struct name_entry entry;
452         int old_baselen = base->len;
453
454         while (tree_entry(tree, &entry)) {
455                 int te_len = tree_entry_len(&entry);
456
457                 if (match != all_entries_interesting) {
458                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
459                         if (match == all_entries_not_interesting)
460                                 break;
461                         if (match == entry_not_interesting)
462                                 continue;
463                 }
464
465                 strbuf_add(base, entry.path, te_len);
466
467                 if (S_ISREG(entry.mode)) {
468                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
469                 }
470                 else if (S_ISDIR(entry.mode)) {
471                         enum object_type type;
472                         struct tree_desc sub;
473                         void *data;
474                         unsigned long size;
475
476                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
477                         if (!data)
478                                 die(_("unable to read tree (%s)"),
479                                     sha1_to_hex(entry.sha1));
480
481                         strbuf_addch(base, '/');
482                         init_tree_desc(&sub, data, size);
483                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
484                         free(data);
485                 }
486                 strbuf_setlen(base, old_baselen);
487
488                 if (hit && opt->status_only)
489                         break;
490         }
491         return hit;
492 }
493
494 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
495                        struct object *obj, const char *name)
496 {
497         if (obj->type == OBJ_BLOB)
498                 return grep_sha1(opt, obj->sha1, name, 0);
499         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
500                 struct tree_desc tree;
501                 void *data;
502                 unsigned long size;
503                 struct strbuf base;
504                 int hit, len;
505
506                 grep_read_lock();
507                 data = read_object_with_reference(obj->sha1, tree_type,
508                                                   &size, NULL);
509                 grep_read_unlock();
510
511                 if (!data)
512                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
513
514                 len = name ? strlen(name) : 0;
515                 strbuf_init(&base, PATH_MAX + len + 1);
516                 if (len) {
517                         strbuf_add(&base, name, len);
518                         strbuf_addch(&base, ':');
519                 }
520                 init_tree_desc(&tree, data, size);
521                 hit = grep_tree(opt, pathspec, &tree, &base, base.len);
522                 strbuf_release(&base);
523                 free(data);
524                 return hit;
525         }
526         die(_("unable to grep from object of type %s"), typename(obj->type));
527 }
528
529 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
530                         const struct object_array *list)
531 {
532         unsigned int i;
533         int hit = 0;
534         const unsigned int nr = list->nr;
535
536         for (i = 0; i < nr; i++) {
537                 struct object *real_obj;
538                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
539                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
540                         hit = 1;
541                         if (opt->status_only)
542                                 break;
543                 }
544         }
545         return hit;
546 }
547
548 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
549                           int exc_std)
550 {
551         struct dir_struct dir;
552         int i, hit = 0;
553
554         memset(&dir, 0, sizeof(dir));
555         if (exc_std)
556                 setup_standard_excludes(&dir);
557
558         fill_directory(&dir, pathspec->raw);
559         for (i = 0; i < dir.nr; i++) {
560                 const char *name = dir.entries[i]->name;
561                 int namelen = strlen(name);
562                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
563                         continue;
564                 hit |= grep_file(opt, dir.entries[i]->name);
565                 if (hit && opt->status_only)
566                         break;
567         }
568         return hit;
569 }
570
571 static int context_callback(const struct option *opt, const char *arg,
572                             int unset)
573 {
574         struct grep_opt *grep_opt = opt->value;
575         int value;
576         const char *endp;
577
578         if (unset) {
579                 grep_opt->pre_context = grep_opt->post_context = 0;
580                 return 0;
581         }
582         value = strtol(arg, (char **)&endp, 10);
583         if (*endp) {
584                 return error(_("switch `%c' expects a numerical value"),
585                              opt->short_name);
586         }
587         grep_opt->pre_context = grep_opt->post_context = value;
588         return 0;
589 }
590
591 static int file_callback(const struct option *opt, const char *arg, int unset)
592 {
593         struct grep_opt *grep_opt = opt->value;
594         int from_stdin = !strcmp(arg, "-");
595         FILE *patterns;
596         int lno = 0;
597         struct strbuf sb = STRBUF_INIT;
598
599         patterns = from_stdin ? stdin : fopen(arg, "r");
600         if (!patterns)
601                 die_errno(_("cannot open '%s'"), arg);
602         while (strbuf_getline(&sb, patterns, '\n') == 0) {
603                 /* ignore empty line like grep does */
604                 if (sb.len == 0)
605                         continue;
606
607                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
608                                 GREP_PATTERN);
609         }
610         if (!from_stdin)
611                 fclose(patterns);
612         strbuf_release(&sb);
613         return 0;
614 }
615
616 static int not_callback(const struct option *opt, const char *arg, int unset)
617 {
618         struct grep_opt *grep_opt = opt->value;
619         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
620         return 0;
621 }
622
623 static int and_callback(const struct option *opt, const char *arg, int unset)
624 {
625         struct grep_opt *grep_opt = opt->value;
626         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
627         return 0;
628 }
629
630 static int open_callback(const struct option *opt, const char *arg, int unset)
631 {
632         struct grep_opt *grep_opt = opt->value;
633         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
634         return 0;
635 }
636
637 static int close_callback(const struct option *opt, const char *arg, int unset)
638 {
639         struct grep_opt *grep_opt = opt->value;
640         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
641         return 0;
642 }
643
644 static int pattern_callback(const struct option *opt, const char *arg,
645                             int unset)
646 {
647         struct grep_opt *grep_opt = opt->value;
648         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
649         return 0;
650 }
651
652 static int help_callback(const struct option *opt, const char *arg, int unset)
653 {
654         return -1;
655 }
656
657 int cmd_grep(int argc, const char **argv, const char *prefix)
658 {
659         int hit = 0;
660         int cached = 0, untracked = 0, opt_exclude = -1;
661         int seen_dashdash = 0;
662         int external_grep_allowed__ignored;
663         const char *show_in_pager = NULL, *default_pager = "dummy";
664         struct grep_opt opt;
665         struct object_array list = OBJECT_ARRAY_INIT;
666         const char **paths = NULL;
667         struct pathspec pathspec;
668         struct string_list path_list = STRING_LIST_INIT_NODUP;
669         int i;
670         int dummy;
671         int use_index = 1;
672         enum {
673                 pattern_type_unspecified = 0,
674                 pattern_type_bre,
675                 pattern_type_ere,
676                 pattern_type_fixed,
677                 pattern_type_pcre,
678         };
679         int pattern_type = pattern_type_unspecified;
680
681         struct option options[] = {
682                 OPT_BOOLEAN(0, "cached", &cached,
683                         "search in index instead of in the work tree"),
684                 OPT_NEGBIT(0, "no-index", &use_index,
685                          "finds in contents not managed by git", 1),
686                 OPT_BOOLEAN(0, "untracked", &untracked,
687                         "search in both tracked and untracked files"),
688                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
689                             "search also in ignored files", 1),
690                 OPT_GROUP(""),
691                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
692                         "show non-matching lines"),
693                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
694                         "case insensitive matching"),
695                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
696                         "match patterns only at word boundaries"),
697                 OPT_SET_INT('a', "text", &opt.binary,
698                         "process binary files as text", GREP_BINARY_TEXT),
699                 OPT_SET_INT('I', NULL, &opt.binary,
700                         "don't match patterns in binary files",
701                         GREP_BINARY_NOMATCH),
702                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
703                         "descend at most <depth> levels", PARSE_OPT_NONEG,
704                         NULL, 1 },
705                 OPT_GROUP(""),
706                 OPT_SET_INT('E', "extended-regexp", &pattern_type,
707                             "use extended POSIX regular expressions",
708                             pattern_type_ere),
709                 OPT_SET_INT('G', "basic-regexp", &pattern_type,
710                             "use basic POSIX regular expressions (default)",
711                             pattern_type_bre),
712                 OPT_SET_INT('F', "fixed-strings", &pattern_type,
713                             "interpret patterns as fixed strings",
714                             pattern_type_fixed),
715                 OPT_SET_INT('P', "perl-regexp", &pattern_type,
716                             "use Perl-compatible regular expressions",
717                             pattern_type_pcre),
718                 OPT_GROUP(""),
719                 OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
720                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
721                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
722                 OPT_NEGBIT(0, "full-name", &opt.relative,
723                         "show filenames relative to top directory", 1),
724                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
725                         "show only filenames instead of matching lines"),
726                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
727                         "synonym for --files-with-matches"),
728                 OPT_BOOLEAN('L', "files-without-match",
729                         &opt.unmatch_name_only,
730                         "show only the names of files without match"),
731                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
732                         "print NUL after filenames"),
733                 OPT_BOOLEAN('c', "count", &opt.count,
734                         "show the number of matches instead of matching lines"),
735                 OPT__COLOR(&opt.color, "highlight matches"),
736                 OPT_BOOLEAN(0, "break", &opt.file_break,
737                         "print empty line between matches from different files"),
738                 OPT_BOOLEAN(0, "heading", &opt.heading,
739                         "show filename only once above matches from same file"),
740                 OPT_GROUP(""),
741                 OPT_CALLBACK('C', "context", &opt, "n",
742                         "show <n> context lines before and after matches",
743                         context_callback),
744                 OPT_INTEGER('B', "before-context", &opt.pre_context,
745                         "show <n> context lines before matches"),
746                 OPT_INTEGER('A', "after-context", &opt.post_context,
747                         "show <n> context lines after matches"),
748                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
749                         context_callback),
750                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
751                         "show a line with the function name before matches"),
752                 OPT_BOOLEAN('W', "function-context", &opt.funcbody,
753                         "show the surrounding function"),
754                 OPT_GROUP(""),
755                 OPT_CALLBACK('f', NULL, &opt, "file",
756                         "read patterns from file", file_callback),
757                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
758                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
759                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
760                   "combine patterns specified with -e",
761                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
762                 OPT_BOOLEAN(0, "or", &dummy, ""),
763                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
764                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
765                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
766                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
767                   open_callback },
768                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
769                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
770                   close_callback },
771                 OPT__QUIET(&opt.status_only,
772                            "indicate hit with exit status without output"),
773                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
774                         "show only matches from files that match all patterns"),
775                 OPT_GROUP(""),
776                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
777                         "pager", "show matching files in the pager",
778                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
779                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
780                             "allow calling of grep(1) (ignored by this build)"),
781                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
782                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
783                 OPT_END()
784         };
785
786         /*
787          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
788          * to show usage information and exit.
789          */
790         if (argc == 2 && !strcmp(argv[1], "-h"))
791                 usage_with_options(grep_usage, options);
792
793         memset(&opt, 0, sizeof(opt));
794         opt.prefix = prefix;
795         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
796         opt.relative = 1;
797         opt.pathname = 1;
798         opt.pattern_tail = &opt.pattern_list;
799         opt.header_tail = &opt.header_list;
800         opt.regflags = REG_NEWLINE;
801         opt.max_depth = -1;
802
803         strcpy(opt.color_context, "");
804         strcpy(opt.color_filename, "");
805         strcpy(opt.color_function, "");
806         strcpy(opt.color_lineno, "");
807         strcpy(opt.color_match, GIT_COLOR_BOLD_RED);
808         strcpy(opt.color_selected, "");
809         strcpy(opt.color_sep, GIT_COLOR_CYAN);
810         opt.color = -1;
811         git_config(grep_config, &opt);
812
813         /*
814          * If there is no -- then the paths must exist in the working
815          * tree.  If there is no explicit pattern specified with -e or
816          * -f, we take the first unrecognized non option to be the
817          * pattern, but then what follows it must be zero or more
818          * valid refs up to the -- (if exists), and then existing
819          * paths.  If there is an explicit pattern, then the first
820          * unrecognized non option is the beginning of the refs list
821          * that continues up to the -- (if exists), and then paths.
822          */
823         argc = parse_options(argc, argv, prefix, options, grep_usage,
824                              PARSE_OPT_KEEP_DASHDASH |
825                              PARSE_OPT_STOP_AT_NON_OPTION |
826                              PARSE_OPT_NO_INTERNAL_HELP);
827         switch (pattern_type) {
828         case pattern_type_fixed:
829                 opt.fixed = 1;
830                 opt.pcre = 0;
831                 break;
832         case pattern_type_bre:
833                 opt.fixed = 0;
834                 opt.pcre = 0;
835                 opt.regflags &= ~REG_EXTENDED;
836                 break;
837         case pattern_type_ere:
838                 opt.fixed = 0;
839                 opt.pcre = 0;
840                 opt.regflags |= REG_EXTENDED;
841                 break;
842         case pattern_type_pcre:
843                 opt.fixed = 0;
844                 opt.pcre = 1;
845                 break;
846         default:
847                 break; /* nothing */
848         }
849
850         if (use_index && !startup_info->have_repository)
851                 /* die the same way as if we did it at the beginning */
852                 setup_git_directory();
853
854         /*
855          * skip a -- separator; we know it cannot be
856          * separating revisions from pathnames if
857          * we haven't even had any patterns yet
858          */
859         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
860                 argv++;
861                 argc--;
862         }
863
864         /* First unrecognized non-option token */
865         if (argc > 0 && !opt.pattern_list) {
866                 append_grep_pattern(&opt, argv[0], "command line", 0,
867                                     GREP_PATTERN);
868                 argv++;
869                 argc--;
870         }
871
872         if (show_in_pager == default_pager)
873                 show_in_pager = git_pager(1);
874         if (show_in_pager) {
875                 opt.color = 0;
876                 opt.name_only = 1;
877                 opt.null_following_name = 1;
878                 opt.output_priv = &path_list;
879                 opt.output = append_path;
880                 string_list_append(&path_list, show_in_pager);
881                 use_threads = 0;
882         }
883
884         if (!opt.pattern_list)
885                 die(_("no pattern given."));
886         if (!opt.fixed && opt.ignore_case)
887                 opt.regflags |= REG_ICASE;
888
889         compile_grep_patterns(&opt);
890
891         /* Check revs and then paths */
892         for (i = 0; i < argc; i++) {
893                 const char *arg = argv[i];
894                 unsigned char sha1[20];
895                 /* Is it a rev? */
896                 if (!get_sha1(arg, sha1)) {
897                         struct object *object = parse_object(sha1);
898                         if (!object)
899                                 die(_("bad object %s"), arg);
900                         add_object_array(object, arg, &list);
901                         continue;
902                 }
903                 if (!strcmp(arg, "--")) {
904                         i++;
905                         seen_dashdash = 1;
906                 }
907                 break;
908         }
909
910 #ifndef NO_PTHREADS
911         if (list.nr || cached || online_cpus() == 1)
912                 use_threads = 0;
913 #else
914         use_threads = 0;
915 #endif
916
917 #ifndef NO_PTHREADS
918         if (use_threads) {
919                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
920                     && (opt.pre_context || opt.post_context ||
921                         opt.file_break || opt.funcbody))
922                         skip_first_line = 1;
923                 start_threads(&opt);
924         }
925 #endif
926
927         /* The rest are paths */
928         if (!seen_dashdash) {
929                 int j;
930                 for (j = i; j < argc; j++)
931                         verify_filename(prefix, argv[j], j == i);
932         }
933
934         paths = get_pathspec(prefix, argv + i);
935         init_pathspec(&pathspec, paths);
936         pathspec.max_depth = opt.max_depth;
937         pathspec.recursive = 1;
938
939         if (show_in_pager && (cached || list.nr))
940                 die(_("--open-files-in-pager only works on the worktree"));
941
942         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
943                 const char *pager = path_list.items[0].string;
944                 int len = strlen(pager);
945
946                 if (len > 4 && is_dir_sep(pager[len - 5]))
947                         pager += len - 4;
948
949                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
950                         struct strbuf buf = STRBUF_INIT;
951                         strbuf_addf(&buf, "+/%s%s",
952                                         strcmp("less", pager) ? "" : "*",
953                                         opt.pattern_list->pattern);
954                         string_list_append(&path_list, buf.buf);
955                         strbuf_detach(&buf, NULL);
956                 }
957         }
958
959         if (!show_in_pager)
960                 setup_pager();
961
962         if (!use_index && (untracked || cached))
963                 die(_("--cached or --untracked cannot be used with --no-index."));
964
965         if (!use_index || untracked) {
966                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
967                 if (list.nr)
968                         die(_("--no-index or --untracked cannot be used with revs."));
969                 hit = grep_directory(&opt, &pathspec, use_exclude);
970         } else if (0 <= opt_exclude) {
971                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
972         } else if (!list.nr) {
973                 if (!cached)
974                         setup_work_tree();
975
976                 hit = grep_cache(&opt, &pathspec, cached);
977         } else {
978                 if (cached)
979                         die(_("both --cached and trees are given."));
980                 hit = grep_objects(&opt, &pathspec, &list);
981         }
982
983         if (use_threads)
984                 hit |= wait_all();
985         if (hit && show_in_pager)
986                 run_pager(&opt, prefix);
987         free_grep_patterns(&opt);
988         return !hit;
989 }