convert git-grep to use grep_source interface
[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(enum grep_source_type type, const char *name,
89                      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         todo[todo_end].done = 0;
99         strbuf_reset(&todo[todo_end].out);
100         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
101
102         pthread_cond_signal(&cond_add);
103         grep_unlock();
104 }
105
106 static struct work_item *get_work(void)
107 {
108         struct work_item *ret;
109
110         grep_lock();
111         while (todo_start == todo_end && !all_work_added) {
112                 pthread_cond_wait(&cond_add, &grep_mutex);
113         }
114
115         if (todo_start == todo_end && all_work_added) {
116                 ret = NULL;
117         } else {
118                 ret = &todo[todo_start];
119                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
120         }
121         grep_unlock();
122         return ret;
123 }
124
125 static void work_done(struct work_item *w)
126 {
127         int old_done;
128
129         grep_lock();
130         w->done = 1;
131         old_done = todo_done;
132         for(; todo[todo_done].done && todo_done != todo_start;
133             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
134                 w = &todo[todo_done];
135                 if (w->out.len) {
136                         const char *p = w->out.buf;
137                         size_t len = w->out.len;
138
139                         /* Skip the leading hunk mark of the first file. */
140                         if (skip_first_line) {
141                                 while (len) {
142                                         len--;
143                                         if (*p++ == '\n')
144                                                 break;
145                                 }
146                                 skip_first_line = 0;
147                         }
148
149                         write_or_die(1, p, len);
150                 }
151                 grep_source_clear(&w->source);
152         }
153
154         if (old_done != todo_done)
155                 pthread_cond_signal(&cond_write);
156
157         if (all_work_added && todo_done == todo_end)
158                 pthread_cond_signal(&cond_result);
159
160         grep_unlock();
161 }
162
163 static void *run(void *arg)
164 {
165         int hit = 0;
166         struct grep_opt *opt = arg;
167
168         while (1) {
169                 struct work_item *w = get_work();
170                 if (!w)
171                         break;
172
173                 opt->output_priv = w;
174                 hit |= grep_source(opt, &w->source);
175                 grep_source_clear_data(&w->source);
176                 work_done(w);
177         }
178         free_grep_patterns(arg);
179         free(arg);
180
181         return (void*) (intptr_t) hit;
182 }
183
184 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
185 {
186         struct work_item *w = opt->output_priv;
187         strbuf_add(&w->out, buf, size);
188 }
189
190 static void start_threads(struct grep_opt *opt)
191 {
192         int i;
193
194         pthread_mutex_init(&grep_mutex, NULL);
195         pthread_mutex_init(&grep_read_mutex, NULL);
196         pthread_mutex_init(&grep_attr_mutex, NULL);
197         pthread_cond_init(&cond_add, NULL);
198         pthread_cond_init(&cond_write, NULL);
199         pthread_cond_init(&cond_result, NULL);
200         grep_use_locks = 1;
201
202         for (i = 0; i < ARRAY_SIZE(todo); i++) {
203                 strbuf_init(&todo[i].out, 0);
204         }
205
206         for (i = 0; i < ARRAY_SIZE(threads); i++) {
207                 int err;
208                 struct grep_opt *o = grep_opt_dup(opt);
209                 o->output = strbuf_out;
210                 compile_grep_patterns(o);
211                 err = pthread_create(&threads[i], NULL, run, o);
212
213                 if (err)
214                         die(_("grep: failed to create thread: %s"),
215                             strerror(err));
216         }
217 }
218
219 static int wait_all(void)
220 {
221         int hit = 0;
222         int i;
223
224         grep_lock();
225         all_work_added = 1;
226
227         /* Wait until all work is done. */
228         while (todo_done != todo_end)
229                 pthread_cond_wait(&cond_result, &grep_mutex);
230
231         /* Wake up all the consumer threads so they can see that there
232          * is no more work to do.
233          */
234         pthread_cond_broadcast(&cond_add);
235         grep_unlock();
236
237         for (i = 0; i < ARRAY_SIZE(threads); i++) {
238                 void *h;
239                 pthread_join(threads[i], &h);
240                 hit |= (int) (intptr_t) h;
241         }
242
243         pthread_mutex_destroy(&grep_mutex);
244         pthread_mutex_destroy(&grep_read_mutex);
245         pthread_mutex_destroy(&grep_attr_mutex);
246         pthread_cond_destroy(&cond_add);
247         pthread_cond_destroy(&cond_write);
248         pthread_cond_destroy(&cond_result);
249         grep_use_locks = 0;
250
251         return hit;
252 }
253 #else /* !NO_PTHREADS */
254
255 static int wait_all(void)
256 {
257         return 0;
258 }
259 #endif
260
261 static int grep_config(const char *var, const char *value, void *cb)
262 {
263         struct grep_opt *opt = cb;
264         char *color = NULL;
265
266         switch (userdiff_config(var, value)) {
267         case 0: break;
268         case -1: return -1;
269         default: return 0;
270         }
271
272         if (!strcmp(var, "grep.extendedregexp")) {
273                 if (git_config_bool(var, value))
274                         opt->regflags |= REG_EXTENDED;
275                 else
276                         opt->regflags &= ~REG_EXTENDED;
277                 return 0;
278         }
279
280         if (!strcmp(var, "grep.linenumber")) {
281                 opt->linenum = git_config_bool(var, value);
282                 return 0;
283         }
284
285         if (!strcmp(var, "color.grep"))
286                 opt->color = git_config_colorbool(var, value);
287         else if (!strcmp(var, "color.grep.context"))
288                 color = opt->color_context;
289         else if (!strcmp(var, "color.grep.filename"))
290                 color = opt->color_filename;
291         else if (!strcmp(var, "color.grep.function"))
292                 color = opt->color_function;
293         else if (!strcmp(var, "color.grep.linenumber"))
294                 color = opt->color_lineno;
295         else if (!strcmp(var, "color.grep.match"))
296                 color = opt->color_match;
297         else if (!strcmp(var, "color.grep.selected"))
298                 color = opt->color_selected;
299         else if (!strcmp(var, "color.grep.separator"))
300                 color = opt->color_sep;
301         else
302                 return git_color_default_config(var, value, cb);
303         if (color) {
304                 if (!value)
305                         return config_error_nonbool(var);
306                 color_parse(value, var, color);
307         }
308         return 0;
309 }
310
311 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
312 {
313         void *data;
314
315         grep_read_lock();
316         data = read_sha1_file(sha1, type, size);
317         grep_read_unlock();
318         return data;
319 }
320
321 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
322                      const char *filename, int tree_name_len)
323 {
324         struct strbuf pathbuf = STRBUF_INIT;
325
326         if (opt->relative && opt->prefix_length) {
327                 quote_path_relative(filename + tree_name_len, -1, &pathbuf,
328                                     opt->prefix);
329                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
330         } else {
331                 strbuf_addstr(&pathbuf, filename);
332         }
333
334 #ifndef NO_PTHREADS
335         if (use_threads) {
336                 add_work(GREP_SOURCE_SHA1, pathbuf.buf, sha1);
337                 strbuf_release(&pathbuf);
338                 return 0;
339         } else
340 #endif
341         {
342                 struct grep_source gs;
343                 int hit;
344
345                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
346                 strbuf_release(&pathbuf);
347                 hit = grep_source(opt, &gs);
348
349                 grep_source_clear(&gs);
350                 return hit;
351         }
352 }
353
354 static int grep_file(struct grep_opt *opt, const char *filename)
355 {
356         struct strbuf buf = STRBUF_INIT;
357
358         if (opt->relative && opt->prefix_length)
359                 quote_path_relative(filename, -1, &buf, opt->prefix);
360         else
361                 strbuf_addstr(&buf, filename);
362
363 #ifndef NO_PTHREADS
364         if (use_threads) {
365                 add_work(GREP_SOURCE_FILE, buf.buf, filename);
366                 strbuf_release(&buf);
367                 return 0;
368         } else
369 #endif
370         {
371                 struct grep_source gs;
372                 int hit;
373
374                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename);
375                 strbuf_release(&buf);
376                 hit = grep_source(opt, &gs);
377
378                 grep_source_clear(&gs);
379                 return hit;
380         }
381 }
382
383 static void append_path(struct grep_opt *opt, const void *data, size_t len)
384 {
385         struct string_list *path_list = opt->output_priv;
386
387         if (len == 1 && *(const char *)data == '\0')
388                 return;
389         string_list_append(path_list, xstrndup(data, len));
390 }
391
392 static void run_pager(struct grep_opt *opt, const char *prefix)
393 {
394         struct string_list *path_list = opt->output_priv;
395         const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
396         int i, status;
397
398         for (i = 0; i < path_list->nr; i++)
399                 argv[i] = path_list->items[i].string;
400         argv[path_list->nr] = NULL;
401
402         if (prefix && chdir(prefix))
403                 die(_("Failed to chdir: %s"), prefix);
404         status = run_command_v_opt(argv, RUN_USING_SHELL);
405         if (status)
406                 exit(status);
407         free(argv);
408 }
409
410 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
411 {
412         int hit = 0;
413         int nr;
414         read_cache();
415
416         for (nr = 0; nr < active_nr; nr++) {
417                 struct cache_entry *ce = active_cache[nr];
418                 if (!S_ISREG(ce->ce_mode))
419                         continue;
420                 if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
421                         continue;
422                 /*
423                  * If CE_VALID is on, we assume worktree file and its cache entry
424                  * are identical, even if worktree file has been modified, so use
425                  * cache version instead
426                  */
427                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
428                         if (ce_stage(ce))
429                                 continue;
430                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
431                 }
432                 else
433                         hit |= grep_file(opt, ce->name);
434                 if (ce_stage(ce)) {
435                         do {
436                                 nr++;
437                         } while (nr < active_nr &&
438                                  !strcmp(ce->name, active_cache[nr]->name));
439                         nr--; /* compensate for loop control */
440                 }
441                 if (hit && opt->status_only)
442                         break;
443         }
444         return hit;
445 }
446
447 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
448                      struct tree_desc *tree, struct strbuf *base, int tn_len)
449 {
450         int hit = 0;
451         enum interesting match = entry_not_interesting;
452         struct name_entry entry;
453         int old_baselen = base->len;
454
455         while (tree_entry(tree, &entry)) {
456                 int te_len = tree_entry_len(&entry);
457
458                 if (match != all_entries_interesting) {
459                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
460                         if (match == all_entries_not_interesting)
461                                 break;
462                         if (match == entry_not_interesting)
463                                 continue;
464                 }
465
466                 strbuf_add(base, entry.path, te_len);
467
468                 if (S_ISREG(entry.mode)) {
469                         hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
470                 }
471                 else if (S_ISDIR(entry.mode)) {
472                         enum object_type type;
473                         struct tree_desc sub;
474                         void *data;
475                         unsigned long size;
476
477                         data = lock_and_read_sha1_file(entry.sha1, &type, &size);
478                         if (!data)
479                                 die(_("unable to read tree (%s)"),
480                                     sha1_to_hex(entry.sha1));
481
482                         strbuf_addch(base, '/');
483                         init_tree_desc(&sub, data, size);
484                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
485                         free(data);
486                 }
487                 strbuf_setlen(base, old_baselen);
488
489                 if (hit && opt->status_only)
490                         break;
491         }
492         return hit;
493 }
494
495 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
496                        struct object *obj, const char *name)
497 {
498         if (obj->type == OBJ_BLOB)
499                 return grep_sha1(opt, obj->sha1, name, 0);
500         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
501                 struct tree_desc tree;
502                 void *data;
503                 unsigned long size;
504                 struct strbuf base;
505                 int hit, len;
506
507                 grep_read_lock();
508                 data = read_object_with_reference(obj->sha1, tree_type,
509                                                   &size, NULL);
510                 grep_read_unlock();
511
512                 if (!data)
513                         die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
514
515                 len = name ? strlen(name) : 0;
516                 strbuf_init(&base, PATH_MAX + len + 1);
517                 if (len) {
518                         strbuf_add(&base, name, len);
519                         strbuf_addch(&base, ':');
520                 }
521                 init_tree_desc(&tree, data, size);
522                 hit = grep_tree(opt, pathspec, &tree, &base, base.len);
523                 strbuf_release(&base);
524                 free(data);
525                 return hit;
526         }
527         die(_("unable to grep from object of type %s"), typename(obj->type));
528 }
529
530 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
531                         const struct object_array *list)
532 {
533         unsigned int i;
534         int hit = 0;
535         const unsigned int nr = list->nr;
536
537         for (i = 0; i < nr; i++) {
538                 struct object *real_obj;
539                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
540                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
541                         hit = 1;
542                         if (opt->status_only)
543                                 break;
544                 }
545         }
546         return hit;
547 }
548
549 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
550                           int exc_std)
551 {
552         struct dir_struct dir;
553         int i, hit = 0;
554
555         memset(&dir, 0, sizeof(dir));
556         if (exc_std)
557                 setup_standard_excludes(&dir);
558
559         fill_directory(&dir, pathspec->raw);
560         for (i = 0; i < dir.nr; i++) {
561                 const char *name = dir.entries[i]->name;
562                 int namelen = strlen(name);
563                 if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
564                         continue;
565                 hit |= grep_file(opt, dir.entries[i]->name);
566                 if (hit && opt->status_only)
567                         break;
568         }
569         return hit;
570 }
571
572 static int context_callback(const struct option *opt, const char *arg,
573                             int unset)
574 {
575         struct grep_opt *grep_opt = opt->value;
576         int value;
577         const char *endp;
578
579         if (unset) {
580                 grep_opt->pre_context = grep_opt->post_context = 0;
581                 return 0;
582         }
583         value = strtol(arg, (char **)&endp, 10);
584         if (*endp) {
585                 return error(_("switch `%c' expects a numerical value"),
586                              opt->short_name);
587         }
588         grep_opt->pre_context = grep_opt->post_context = value;
589         return 0;
590 }
591
592 static int file_callback(const struct option *opt, const char *arg, int unset)
593 {
594         struct grep_opt *grep_opt = opt->value;
595         int from_stdin = !strcmp(arg, "-");
596         FILE *patterns;
597         int lno = 0;
598         struct strbuf sb = STRBUF_INIT;
599
600         patterns = from_stdin ? stdin : fopen(arg, "r");
601         if (!patterns)
602                 die_errno(_("cannot open '%s'"), arg);
603         while (strbuf_getline(&sb, patterns, '\n') == 0) {
604                 char *s;
605                 size_t len;
606
607                 /* ignore empty line like grep does */
608                 if (sb.len == 0)
609                         continue;
610
611                 s = strbuf_detach(&sb, &len);
612                 append_grep_pat(grep_opt, s, len, arg, ++lno, GREP_PATTERN);
613         }
614         if (!from_stdin)
615                 fclose(patterns);
616         strbuf_release(&sb);
617         return 0;
618 }
619
620 static int not_callback(const struct option *opt, const char *arg, int unset)
621 {
622         struct grep_opt *grep_opt = opt->value;
623         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
624         return 0;
625 }
626
627 static int and_callback(const struct option *opt, const char *arg, int unset)
628 {
629         struct grep_opt *grep_opt = opt->value;
630         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
631         return 0;
632 }
633
634 static int open_callback(const struct option *opt, const char *arg, int unset)
635 {
636         struct grep_opt *grep_opt = opt->value;
637         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
638         return 0;
639 }
640
641 static int close_callback(const struct option *opt, const char *arg, int unset)
642 {
643         struct grep_opt *grep_opt = opt->value;
644         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
645         return 0;
646 }
647
648 static int pattern_callback(const struct option *opt, const char *arg,
649                             int unset)
650 {
651         struct grep_opt *grep_opt = opt->value;
652         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
653         return 0;
654 }
655
656 static int help_callback(const struct option *opt, const char *arg, int unset)
657 {
658         return -1;
659 }
660
661 int cmd_grep(int argc, const char **argv, const char *prefix)
662 {
663         int hit = 0;
664         int cached = 0, untracked = 0, opt_exclude = -1;
665         int seen_dashdash = 0;
666         int external_grep_allowed__ignored;
667         const char *show_in_pager = NULL, *default_pager = "dummy";
668         struct grep_opt opt;
669         struct object_array list = OBJECT_ARRAY_INIT;
670         const char **paths = NULL;
671         struct pathspec pathspec;
672         struct string_list path_list = STRING_LIST_INIT_NODUP;
673         int i;
674         int dummy;
675         int use_index = 1;
676         enum {
677                 pattern_type_unspecified = 0,
678                 pattern_type_bre,
679                 pattern_type_ere,
680                 pattern_type_fixed,
681                 pattern_type_pcre,
682         };
683         int pattern_type = pattern_type_unspecified;
684
685         struct option options[] = {
686                 OPT_BOOLEAN(0, "cached", &cached,
687                         "search in index instead of in the work tree"),
688                 { OPTION_BOOLEAN, 0, "index", &use_index, NULL,
689                         "finds in contents not managed by git",
690                         PARSE_OPT_NOARG | PARSE_OPT_NEGHELP },
691                 OPT_BOOLEAN(0, "untracked", &untracked,
692                         "search in both tracked and untracked files"),
693                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
694                             "search also in ignored files", 1),
695                 OPT_GROUP(""),
696                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
697                         "show non-matching lines"),
698                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
699                         "case insensitive matching"),
700                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
701                         "match patterns only at word boundaries"),
702                 OPT_SET_INT('a', "text", &opt.binary,
703                         "process binary files as text", GREP_BINARY_TEXT),
704                 OPT_SET_INT('I', NULL, &opt.binary,
705                         "don't match patterns in binary files",
706                         GREP_BINARY_NOMATCH),
707                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
708                         "descend at most <depth> levels", PARSE_OPT_NONEG,
709                         NULL, 1 },
710                 OPT_GROUP(""),
711                 OPT_SET_INT('E', "extended-regexp", &pattern_type,
712                             "use extended POSIX regular expressions",
713                             pattern_type_ere),
714                 OPT_SET_INT('G', "basic-regexp", &pattern_type,
715                             "use basic POSIX regular expressions (default)",
716                             pattern_type_bre),
717                 OPT_SET_INT('F', "fixed-strings", &pattern_type,
718                             "interpret patterns as fixed strings",
719                             pattern_type_fixed),
720                 OPT_SET_INT('P', "perl-regexp", &pattern_type,
721                             "use Perl-compatible regular expressions",
722                             pattern_type_pcre),
723                 OPT_GROUP(""),
724                 OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
725                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
726                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
727                 OPT_NEGBIT(0, "full-name", &opt.relative,
728                         "show filenames relative to top directory", 1),
729                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
730                         "show only filenames instead of matching lines"),
731                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
732                         "synonym for --files-with-matches"),
733                 OPT_BOOLEAN('L', "files-without-match",
734                         &opt.unmatch_name_only,
735                         "show only the names of files without match"),
736                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
737                         "print NUL after filenames"),
738                 OPT_BOOLEAN('c', "count", &opt.count,
739                         "show the number of matches instead of matching lines"),
740                 OPT__COLOR(&opt.color, "highlight matches"),
741                 OPT_BOOLEAN(0, "break", &opt.file_break,
742                         "print empty line between matches from different files"),
743                 OPT_BOOLEAN(0, "heading", &opt.heading,
744                         "show filename only once above matches from same file"),
745                 OPT_GROUP(""),
746                 OPT_CALLBACK('C', "context", &opt, "n",
747                         "show <n> context lines before and after matches",
748                         context_callback),
749                 OPT_INTEGER('B', "before-context", &opt.pre_context,
750                         "show <n> context lines before matches"),
751                 OPT_INTEGER('A', "after-context", &opt.post_context,
752                         "show <n> context lines after matches"),
753                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
754                         context_callback),
755                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
756                         "show a line with the function name before matches"),
757                 OPT_BOOLEAN('W', "function-context", &opt.funcbody,
758                         "show the surrounding function"),
759                 OPT_GROUP(""),
760                 OPT_CALLBACK('f', NULL, &opt, "file",
761                         "read patterns from file", file_callback),
762                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
763                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
764                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
765                   "combine patterns specified with -e",
766                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
767                 OPT_BOOLEAN(0, "or", &dummy, ""),
768                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
769                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
770                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
771                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
772                   open_callback },
773                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
774                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
775                   close_callback },
776                 OPT__QUIET(&opt.status_only,
777                            "indicate hit with exit status without output"),
778                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
779                         "show only matches from files that match all patterns"),
780                 OPT_GROUP(""),
781                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
782                         "pager", "show matching files in the pager",
783                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
784                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
785                             "allow calling of grep(1) (ignored by this build)"),
786                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
787                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
788                 OPT_END()
789         };
790
791         /*
792          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
793          * to show usage information and exit.
794          */
795         if (argc == 2 && !strcmp(argv[1], "-h"))
796                 usage_with_options(grep_usage, options);
797
798         memset(&opt, 0, sizeof(opt));
799         opt.prefix = prefix;
800         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
801         opt.relative = 1;
802         opt.pathname = 1;
803         opt.pattern_tail = &opt.pattern_list;
804         opt.header_tail = &opt.header_list;
805         opt.regflags = REG_NEWLINE;
806         opt.max_depth = -1;
807
808         strcpy(opt.color_context, "");
809         strcpy(opt.color_filename, "");
810         strcpy(opt.color_function, "");
811         strcpy(opt.color_lineno, "");
812         strcpy(opt.color_match, GIT_COLOR_BOLD_RED);
813         strcpy(opt.color_selected, "");
814         strcpy(opt.color_sep, GIT_COLOR_CYAN);
815         opt.color = -1;
816         git_config(grep_config, &opt);
817
818         /*
819          * If there is no -- then the paths must exist in the working
820          * tree.  If there is no explicit pattern specified with -e or
821          * -f, we take the first unrecognized non option to be the
822          * pattern, but then what follows it must be zero or more
823          * valid refs up to the -- (if exists), and then existing
824          * paths.  If there is an explicit pattern, then the first
825          * unrecognized non option is the beginning of the refs list
826          * that continues up to the -- (if exists), and then paths.
827          */
828         argc = parse_options(argc, argv, prefix, options, grep_usage,
829                              PARSE_OPT_KEEP_DASHDASH |
830                              PARSE_OPT_STOP_AT_NON_OPTION |
831                              PARSE_OPT_NO_INTERNAL_HELP);
832         switch (pattern_type) {
833         case pattern_type_fixed:
834                 opt.fixed = 1;
835                 opt.pcre = 0;
836                 break;
837         case pattern_type_bre:
838                 opt.fixed = 0;
839                 opt.pcre = 0;
840                 opt.regflags &= ~REG_EXTENDED;
841                 break;
842         case pattern_type_ere:
843                 opt.fixed = 0;
844                 opt.pcre = 0;
845                 opt.regflags |= REG_EXTENDED;
846                 break;
847         case pattern_type_pcre:
848                 opt.fixed = 0;
849                 opt.pcre = 1;
850                 break;
851         default:
852                 break; /* nothing */
853         }
854
855         if (use_index && !startup_info->have_repository)
856                 /* die the same way as if we did it at the beginning */
857                 setup_git_directory();
858
859         /*
860          * skip a -- separator; we know it cannot be
861          * separating revisions from pathnames if
862          * we haven't even had any patterns yet
863          */
864         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
865                 argv++;
866                 argc--;
867         }
868
869         /* First unrecognized non-option token */
870         if (argc > 0 && !opt.pattern_list) {
871                 append_grep_pattern(&opt, argv[0], "command line", 0,
872                                     GREP_PATTERN);
873                 argv++;
874                 argc--;
875         }
876
877         if (show_in_pager == default_pager)
878                 show_in_pager = git_pager(1);
879         if (show_in_pager) {
880                 opt.color = 0;
881                 opt.name_only = 1;
882                 opt.null_following_name = 1;
883                 opt.output_priv = &path_list;
884                 opt.output = append_path;
885                 string_list_append(&path_list, show_in_pager);
886                 use_threads = 0;
887         }
888
889         if (!opt.pattern_list)
890                 die(_("no pattern given."));
891         if (!opt.fixed && opt.ignore_case)
892                 opt.regflags |= REG_ICASE;
893
894         compile_grep_patterns(&opt);
895
896         /* Check revs and then paths */
897         for (i = 0; i < argc; i++) {
898                 const char *arg = argv[i];
899                 unsigned char sha1[20];
900                 /* Is it a rev? */
901                 if (!get_sha1(arg, sha1)) {
902                         struct object *object = parse_object(sha1);
903                         if (!object)
904                                 die(_("bad object %s"), arg);
905                         add_object_array(object, arg, &list);
906                         continue;
907                 }
908                 if (!strcmp(arg, "--")) {
909                         i++;
910                         seen_dashdash = 1;
911                 }
912                 break;
913         }
914
915 #ifndef NO_PTHREADS
916         if (list.nr || cached || online_cpus() == 1)
917                 use_threads = 0;
918 #else
919         use_threads = 0;
920 #endif
921
922 #ifndef NO_PTHREADS
923         if (use_threads) {
924                 if (opt.pre_context || opt.post_context || opt.file_break ||
925                     opt.funcbody)
926                         skip_first_line = 1;
927                 start_threads(&opt);
928         }
929 #endif
930
931         /* The rest are paths */
932         if (!seen_dashdash) {
933                 int j;
934                 for (j = i; j < argc; j++)
935                         verify_filename(prefix, argv[j]);
936         }
937
938         paths = get_pathspec(prefix, argv + i);
939         init_pathspec(&pathspec, paths);
940         pathspec.max_depth = opt.max_depth;
941         pathspec.recursive = 1;
942
943         if (show_in_pager && (cached || list.nr))
944                 die(_("--open-files-in-pager only works on the worktree"));
945
946         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
947                 const char *pager = path_list.items[0].string;
948                 int len = strlen(pager);
949
950                 if (len > 4 && is_dir_sep(pager[len - 5]))
951                         pager += len - 4;
952
953                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
954                         struct strbuf buf = STRBUF_INIT;
955                         strbuf_addf(&buf, "+/%s%s",
956                                         strcmp("less", pager) ? "" : "*",
957                                         opt.pattern_list->pattern);
958                         string_list_append(&path_list, buf.buf);
959                         strbuf_detach(&buf, NULL);
960                 }
961         }
962
963         if (!show_in_pager)
964                 setup_pager();
965
966         if (!use_index && (untracked || cached))
967                 die(_("--cached or --untracked cannot be used with --no-index."));
968
969         if (!use_index || untracked) {
970                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
971                 if (list.nr)
972                         die(_("--no-index or --untracked cannot be used with revs."));
973                 hit = grep_directory(&opt, &pathspec, use_exclude);
974         } else if (0 <= opt_exclude) {
975                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
976         } else if (!list.nr) {
977                 if (!cached)
978                         setup_work_tree();
979
980                 hit = grep_cache(&opt, &pathspec, cached);
981         } else {
982                 if (cached)
983                         die(_("both --cached and trees are given."));
984                 hit = grep_objects(&opt, &pathspec, &list);
985         }
986
987         if (use_threads)
988                 hit |= wait_all();
989         if (hit && show_in_pager)
990                 run_pager(&opt, prefix);
991         free_grep_patterns(&opt);
992         return !hit;
993 }