Merge branch 'dt/disable-bitmap-in-auto-gc' 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 #include "pathspec.h"
21
22 static char const * const grep_usage[] = {
23         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
24         NULL
25 };
26
27 #define GREP_NUM_THREADS_DEFAULT 8
28 static int num_threads;
29
30 #ifndef NO_PTHREADS
31 static pthread_t *threads;
32
33 /* We use one producer thread and THREADS consumer
34  * threads. The producer adds struct work_items to 'todo' and the
35  * consumers pick work items from the same array.
36  */
37 struct work_item {
38         struct grep_source source;
39         char done;
40         struct strbuf out;
41 };
42
43 /* In the range [todo_done, todo_start) in 'todo' we have work_items
44  * that have been or are processed by a consumer thread. We haven't
45  * written the result for these to stdout yet.
46  *
47  * The work_items in [todo_start, todo_end) are waiting to be picked
48  * up by a consumer thread.
49  *
50  * The ranges are modulo TODO_SIZE.
51  */
52 #define TODO_SIZE 128
53 static struct work_item todo[TODO_SIZE];
54 static int todo_start;
55 static int todo_end;
56 static int todo_done;
57
58 /* Has all work items been added? */
59 static int all_work_added;
60
61 /* This lock protects all the variables above. */
62 static pthread_mutex_t grep_mutex;
63
64 static inline void grep_lock(void)
65 {
66         if (num_threads)
67                 pthread_mutex_lock(&grep_mutex);
68 }
69
70 static inline void grep_unlock(void)
71 {
72         if (num_threads)
73                 pthread_mutex_unlock(&grep_mutex);
74 }
75
76 /* Signalled when a new work_item is added to todo. */
77 static pthread_cond_t cond_add;
78
79 /* Signalled when the result from one work_item is written to
80  * stdout.
81  */
82 static pthread_cond_t cond_write;
83
84 /* Signalled when we are finished with everything. */
85 static pthread_cond_t cond_result;
86
87 static int skip_first_line;
88
89 static void add_work(struct grep_opt *opt, enum grep_source_type type,
90                      const char *name, const char *path, const void *id)
91 {
92         grep_lock();
93
94         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
95                 pthread_cond_wait(&cond_write, &grep_mutex);
96         }
97
98         grep_source_init(&todo[todo_end].source, type, name, path, id);
99         if (opt->binary != GREP_BINARY_TEXT)
100                 grep_source_load_driver(&todo[todo_end].source);
101         todo[todo_end].done = 0;
102         strbuf_reset(&todo[todo_end].out);
103         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
104
105         pthread_cond_signal(&cond_add);
106         grep_unlock();
107 }
108
109 static struct work_item *get_work(void)
110 {
111         struct work_item *ret;
112
113         grep_lock();
114         while (todo_start == todo_end && !all_work_added) {
115                 pthread_cond_wait(&cond_add, &grep_mutex);
116         }
117
118         if (todo_start == todo_end && all_work_added) {
119                 ret = NULL;
120         } else {
121                 ret = &todo[todo_start];
122                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
123         }
124         grep_unlock();
125         return ret;
126 }
127
128 static void work_done(struct work_item *w)
129 {
130         int old_done;
131
132         grep_lock();
133         w->done = 1;
134         old_done = todo_done;
135         for(; todo[todo_done].done && todo_done != todo_start;
136             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
137                 w = &todo[todo_done];
138                 if (w->out.len) {
139                         const char *p = w->out.buf;
140                         size_t len = w->out.len;
141
142                         /* Skip the leading hunk mark of the first file. */
143                         if (skip_first_line) {
144                                 while (len) {
145                                         len--;
146                                         if (*p++ == '\n')
147                                                 break;
148                                 }
149                                 skip_first_line = 0;
150                         }
151
152                         write_or_die(1, p, len);
153                 }
154                 grep_source_clear(&w->source);
155         }
156
157         if (old_done != todo_done)
158                 pthread_cond_signal(&cond_write);
159
160         if (all_work_added && todo_done == todo_end)
161                 pthread_cond_signal(&cond_result);
162
163         grep_unlock();
164 }
165
166 static void *run(void *arg)
167 {
168         int hit = 0;
169         struct grep_opt *opt = arg;
170
171         while (1) {
172                 struct work_item *w = get_work();
173                 if (!w)
174                         break;
175
176                 opt->output_priv = w;
177                 hit |= grep_source(opt, &w->source);
178                 grep_source_clear_data(&w->source);
179                 work_done(w);
180         }
181         free_grep_patterns(arg);
182         free(arg);
183
184         return (void*) (intptr_t) hit;
185 }
186
187 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
188 {
189         struct work_item *w = opt->output_priv;
190         strbuf_add(&w->out, buf, size);
191 }
192
193 static void start_threads(struct grep_opt *opt)
194 {
195         int i;
196
197         pthread_mutex_init(&grep_mutex, NULL);
198         pthread_mutex_init(&grep_read_mutex, NULL);
199         pthread_mutex_init(&grep_attr_mutex, NULL);
200         pthread_cond_init(&cond_add, NULL);
201         pthread_cond_init(&cond_write, NULL);
202         pthread_cond_init(&cond_result, NULL);
203         grep_use_locks = 1;
204
205         for (i = 0; i < ARRAY_SIZE(todo); i++) {
206                 strbuf_init(&todo[i].out, 0);
207         }
208
209         threads = xcalloc(num_threads, sizeof(*threads));
210         for (i = 0; i < num_threads; i++) {
211                 int err;
212                 struct grep_opt *o = grep_opt_dup(opt);
213                 o->output = strbuf_out;
214                 o->debug = 0;
215                 compile_grep_patterns(o);
216                 err = pthread_create(&threads[i], NULL, run, o);
217
218                 if (err)
219                         die(_("grep: failed to create thread: %s"),
220                             strerror(err));
221         }
222 }
223
224 static int wait_all(void)
225 {
226         int hit = 0;
227         int i;
228
229         grep_lock();
230         all_work_added = 1;
231
232         /* Wait until all work is done. */
233         while (todo_done != todo_end)
234                 pthread_cond_wait(&cond_result, &grep_mutex);
235
236         /* Wake up all the consumer threads so they can see that there
237          * is no more work to do.
238          */
239         pthread_cond_broadcast(&cond_add);
240         grep_unlock();
241
242         for (i = 0; i < num_threads; i++) {
243                 void *h;
244                 pthread_join(threads[i], &h);
245                 hit |= (int) (intptr_t) h;
246         }
247
248         free(threads);
249
250         pthread_mutex_destroy(&grep_mutex);
251         pthread_mutex_destroy(&grep_read_mutex);
252         pthread_mutex_destroy(&grep_attr_mutex);
253         pthread_cond_destroy(&cond_add);
254         pthread_cond_destroy(&cond_write);
255         pthread_cond_destroy(&cond_result);
256         grep_use_locks = 0;
257
258         return hit;
259 }
260 #else /* !NO_PTHREADS */
261
262 static int wait_all(void)
263 {
264         return 0;
265 }
266 #endif
267
268 static int grep_cmd_config(const char *var, const char *value, void *cb)
269 {
270         int st = grep_config(var, value, cb);
271         if (git_color_default_config(var, value, cb) < 0)
272                 st = -1;
273
274         if (!strcmp(var, "grep.threads")) {
275                 num_threads = git_config_int(var, value);
276                 if (num_threads < 0)
277                         die(_("invalid number of threads specified (%d) for %s"),
278                             num_threads, var);
279         }
280
281         return st;
282 }
283
284 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
285 {
286         void *data;
287
288         grep_read_lock();
289         data = read_sha1_file(sha1, type, size);
290         grep_read_unlock();
291         return data;
292 }
293
294 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
295                      const char *filename, int tree_name_len,
296                      const char *path)
297 {
298         struct strbuf pathbuf = STRBUF_INIT;
299
300         if (opt->relative && opt->prefix_length) {
301                 quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
302                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
303         } else {
304                 strbuf_addstr(&pathbuf, filename);
305         }
306
307 #ifndef NO_PTHREADS
308         if (num_threads) {
309                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
310                 strbuf_release(&pathbuf);
311                 return 0;
312         } else
313 #endif
314         {
315                 struct grep_source gs;
316                 int hit;
317
318                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
319                 strbuf_release(&pathbuf);
320                 hit = grep_source(opt, &gs);
321
322                 grep_source_clear(&gs);
323                 return hit;
324         }
325 }
326
327 static int grep_file(struct grep_opt *opt, const char *filename)
328 {
329         struct strbuf buf = STRBUF_INIT;
330
331         if (opt->relative && opt->prefix_length)
332                 quote_path_relative(filename, opt->prefix, &buf);
333         else
334                 strbuf_addstr(&buf, filename);
335
336 #ifndef NO_PTHREADS
337         if (num_threads) {
338                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename, filename);
339                 strbuf_release(&buf);
340                 return 0;
341         } else
342 #endif
343         {
344                 struct grep_source gs;
345                 int hit;
346
347                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
348                 strbuf_release(&buf);
349                 hit = grep_source(opt, &gs);
350
351                 grep_source_clear(&gs);
352                 return hit;
353         }
354 }
355
356 static void append_path(struct grep_opt *opt, const void *data, size_t len)
357 {
358         struct string_list *path_list = opt->output_priv;
359
360         if (len == 1 && *(const char *)data == '\0')
361                 return;
362         string_list_append(path_list, xstrndup(data, len));
363 }
364
365 static void run_pager(struct grep_opt *opt, const char *prefix)
366 {
367         struct string_list *path_list = opt->output_priv;
368         struct child_process child = CHILD_PROCESS_INIT;
369         int i, status;
370
371         for (i = 0; i < path_list->nr; i++)
372                 argv_array_push(&child.args, path_list->items[i].string);
373         child.dir = prefix;
374         child.use_shell = 1;
375
376         status = run_command(&child);
377         if (status)
378                 exit(status);
379 }
380
381 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
382 {
383         int hit = 0;
384         int nr;
385         read_cache();
386
387         for (nr = 0; nr < active_nr; nr++) {
388                 const struct cache_entry *ce = active_cache[nr];
389                 if (!S_ISREG(ce->ce_mode))
390                         continue;
391                 if (!ce_path_match(ce, pathspec, NULL))
392                         continue;
393                 /*
394                  * If CE_VALID is on, we assume worktree file and its cache entry
395                  * are identical, even if worktree file has been modified, so use
396                  * cache version instead
397                  */
398                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
399                         if (ce_stage(ce) || ce_intent_to_add(ce))
400                                 continue;
401                         hit |= grep_sha1(opt, ce->oid.hash, ce->name, 0,
402                                          ce->name);
403                 }
404                 else
405                         hit |= grep_file(opt, ce->name);
406                 if (ce_stage(ce)) {
407                         do {
408                                 nr++;
409                         } while (nr < active_nr &&
410                                  !strcmp(ce->name, active_cache[nr]->name));
411                         nr--; /* compensate for loop control */
412                 }
413                 if (hit && opt->status_only)
414                         break;
415         }
416         return hit;
417 }
418
419 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
420                      struct tree_desc *tree, struct strbuf *base, int tn_len,
421                      int check_attr)
422 {
423         int hit = 0;
424         enum interesting match = entry_not_interesting;
425         struct name_entry entry;
426         int old_baselen = base->len;
427
428         while (tree_entry(tree, &entry)) {
429                 int te_len = tree_entry_len(&entry);
430
431                 if (match != all_entries_interesting) {
432                         match = tree_entry_interesting(&entry, base, tn_len, pathspec);
433                         if (match == all_entries_not_interesting)
434                                 break;
435                         if (match == entry_not_interesting)
436                                 continue;
437                 }
438
439                 strbuf_add(base, entry.path, te_len);
440
441                 if (S_ISREG(entry.mode)) {
442                         hit |= grep_sha1(opt, entry.oid->hash, base->buf, tn_len,
443                                          check_attr ? base->buf + tn_len : NULL);
444                 }
445                 else if (S_ISDIR(entry.mode)) {
446                         enum object_type type;
447                         struct tree_desc sub;
448                         void *data;
449                         unsigned long size;
450
451                         data = lock_and_read_sha1_file(entry.oid->hash, &type, &size);
452                         if (!data)
453                                 die(_("unable to read tree (%s)"),
454                                     oid_to_hex(entry.oid));
455
456                         strbuf_addch(base, '/');
457                         init_tree_desc(&sub, data, size);
458                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
459                                          check_attr);
460                         free(data);
461                 }
462                 strbuf_setlen(base, old_baselen);
463
464                 if (hit && opt->status_only)
465                         break;
466         }
467         return hit;
468 }
469
470 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
471                        struct object *obj, const char *name, const char *path)
472 {
473         if (obj->type == OBJ_BLOB)
474                 return grep_sha1(opt, obj->oid.hash, name, 0, path);
475         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
476                 struct tree_desc tree;
477                 void *data;
478                 unsigned long size;
479                 struct strbuf base;
480                 int hit, len;
481
482                 grep_read_lock();
483                 data = read_object_with_reference(obj->oid.hash, tree_type,
484                                                   &size, NULL);
485                 grep_read_unlock();
486
487                 if (!data)
488                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
489
490                 len = name ? strlen(name) : 0;
491                 strbuf_init(&base, PATH_MAX + len + 1);
492                 if (len) {
493                         strbuf_add(&base, name, len);
494                         strbuf_addch(&base, ':');
495                 }
496                 init_tree_desc(&tree, data, size);
497                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
498                                 obj->type == OBJ_COMMIT);
499                 strbuf_release(&base);
500                 free(data);
501                 return hit;
502         }
503         die(_("unable to grep from object of type %s"), typename(obj->type));
504 }
505
506 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
507                         const struct object_array *list)
508 {
509         unsigned int i;
510         int hit = 0;
511         const unsigned int nr = list->nr;
512
513         for (i = 0; i < nr; i++) {
514                 struct object *real_obj;
515                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
516                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name, list->objects[i].path)) {
517                         hit = 1;
518                         if (opt->status_only)
519                                 break;
520                 }
521         }
522         return hit;
523 }
524
525 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
526                           int exc_std, int use_index)
527 {
528         struct dir_struct dir;
529         int i, hit = 0;
530
531         memset(&dir, 0, sizeof(dir));
532         if (!use_index)
533                 dir.flags |= DIR_NO_GITLINKS;
534         if (exc_std)
535                 setup_standard_excludes(&dir);
536
537         fill_directory(&dir, pathspec);
538         for (i = 0; i < dir.nr; i++) {
539                 if (!dir_path_match(dir.entries[i], pathspec, 0, NULL))
540                         continue;
541                 hit |= grep_file(opt, dir.entries[i]->name);
542                 if (hit && opt->status_only)
543                         break;
544         }
545         return hit;
546 }
547
548 static int context_callback(const struct option *opt, const char *arg,
549                             int unset)
550 {
551         struct grep_opt *grep_opt = opt->value;
552         int value;
553         const char *endp;
554
555         if (unset) {
556                 grep_opt->pre_context = grep_opt->post_context = 0;
557                 return 0;
558         }
559         value = strtol(arg, (char **)&endp, 10);
560         if (*endp) {
561                 return error(_("switch `%c' expects a numerical value"),
562                              opt->short_name);
563         }
564         grep_opt->pre_context = grep_opt->post_context = value;
565         return 0;
566 }
567
568 static int file_callback(const struct option *opt, const char *arg, int unset)
569 {
570         struct grep_opt *grep_opt = opt->value;
571         int from_stdin = !strcmp(arg, "-");
572         FILE *patterns;
573         int lno = 0;
574         struct strbuf sb = STRBUF_INIT;
575
576         patterns = from_stdin ? stdin : fopen(arg, "r");
577         if (!patterns)
578                 die_errno(_("cannot open '%s'"), arg);
579         while (strbuf_getline(&sb, patterns) == 0) {
580                 /* ignore empty line like grep does */
581                 if (sb.len == 0)
582                         continue;
583
584                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
585                                 GREP_PATTERN);
586         }
587         if (!from_stdin)
588                 fclose(patterns);
589         strbuf_release(&sb);
590         return 0;
591 }
592
593 static int not_callback(const struct option *opt, const char *arg, int unset)
594 {
595         struct grep_opt *grep_opt = opt->value;
596         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
597         return 0;
598 }
599
600 static int and_callback(const struct option *opt, const char *arg, int unset)
601 {
602         struct grep_opt *grep_opt = opt->value;
603         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
604         return 0;
605 }
606
607 static int open_callback(const struct option *opt, const char *arg, int unset)
608 {
609         struct grep_opt *grep_opt = opt->value;
610         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
611         return 0;
612 }
613
614 static int close_callback(const struct option *opt, const char *arg, int unset)
615 {
616         struct grep_opt *grep_opt = opt->value;
617         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
618         return 0;
619 }
620
621 static int pattern_callback(const struct option *opt, const char *arg,
622                             int unset)
623 {
624         struct grep_opt *grep_opt = opt->value;
625         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
626         return 0;
627 }
628
629 int cmd_grep(int argc, const char **argv, const char *prefix)
630 {
631         int hit = 0;
632         int cached = 0, untracked = 0, opt_exclude = -1;
633         int seen_dashdash = 0;
634         int external_grep_allowed__ignored;
635         const char *show_in_pager = NULL, *default_pager = "dummy";
636         struct grep_opt opt;
637         struct object_array list = OBJECT_ARRAY_INIT;
638         struct pathspec pathspec;
639         struct string_list path_list = STRING_LIST_INIT_NODUP;
640         int i;
641         int dummy;
642         int use_index = 1;
643         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
644
645         struct option options[] = {
646                 OPT_BOOL(0, "cached", &cached,
647                         N_("search in index instead of in the work tree")),
648                 OPT_NEGBIT(0, "no-index", &use_index,
649                          N_("find in contents not managed by git"), 1),
650                 OPT_BOOL(0, "untracked", &untracked,
651                         N_("search in both tracked and untracked files")),
652                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
653                             N_("ignore files specified via '.gitignore'"), 1),
654                 OPT_GROUP(""),
655                 OPT_BOOL('v', "invert-match", &opt.invert,
656                         N_("show non-matching lines")),
657                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
658                         N_("case insensitive matching")),
659                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
660                         N_("match patterns only at word boundaries")),
661                 OPT_SET_INT('a', "text", &opt.binary,
662                         N_("process binary files as text"), GREP_BINARY_TEXT),
663                 OPT_SET_INT('I', NULL, &opt.binary,
664                         N_("don't match patterns in binary files"),
665                         GREP_BINARY_NOMATCH),
666                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
667                          N_("process binary files with textconv filters")),
668                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
669                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
670                         NULL, 1 },
671                 OPT_GROUP(""),
672                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
673                             N_("use extended POSIX regular expressions"),
674                             GREP_PATTERN_TYPE_ERE),
675                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
676                             N_("use basic POSIX regular expressions (default)"),
677                             GREP_PATTERN_TYPE_BRE),
678                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
679                             N_("interpret patterns as fixed strings"),
680                             GREP_PATTERN_TYPE_FIXED),
681                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
682                             N_("use Perl-compatible regular expressions"),
683                             GREP_PATTERN_TYPE_PCRE),
684                 OPT_GROUP(""),
685                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
686                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
687                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
688                 OPT_NEGBIT(0, "full-name", &opt.relative,
689                         N_("show filenames relative to top directory"), 1),
690                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
691                         N_("show only filenames instead of matching lines")),
692                 OPT_BOOL(0, "name-only", &opt.name_only,
693                         N_("synonym for --files-with-matches")),
694                 OPT_BOOL('L', "files-without-match",
695                         &opt.unmatch_name_only,
696                         N_("show only the names of files without match")),
697                 OPT_BOOL('z', "null", &opt.null_following_name,
698                         N_("print NUL after filenames")),
699                 OPT_BOOL('c', "count", &opt.count,
700                         N_("show the number of matches instead of matching lines")),
701                 OPT__COLOR(&opt.color, N_("highlight matches")),
702                 OPT_BOOL(0, "break", &opt.file_break,
703                         N_("print empty line between matches from different files")),
704                 OPT_BOOL(0, "heading", &opt.heading,
705                         N_("show filename only once above matches from same file")),
706                 OPT_GROUP(""),
707                 OPT_CALLBACK('C', "context", &opt, N_("n"),
708                         N_("show <n> context lines before and after matches"),
709                         context_callback),
710                 OPT_INTEGER('B', "before-context", &opt.pre_context,
711                         N_("show <n> context lines before matches")),
712                 OPT_INTEGER('A', "after-context", &opt.post_context,
713                         N_("show <n> context lines after matches")),
714                 OPT_INTEGER(0, "threads", &num_threads,
715                         N_("use <n> worker threads")),
716                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
717                         context_callback),
718                 OPT_BOOL('p', "show-function", &opt.funcname,
719                         N_("show a line with the function name before matches")),
720                 OPT_BOOL('W', "function-context", &opt.funcbody,
721                         N_("show the surrounding function")),
722                 OPT_GROUP(""),
723                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
724                         N_("read patterns from file"), file_callback),
725                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
726                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
727                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
728                   N_("combine patterns specified with -e"),
729                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
730                 OPT_BOOL(0, "or", &dummy, ""),
731                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
732                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
733                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
734                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
735                   open_callback },
736                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
737                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
738                   close_callback },
739                 OPT__QUIET(&opt.status_only,
740                            N_("indicate hit with exit status without output")),
741                 OPT_BOOL(0, "all-match", &opt.all_match,
742                         N_("show only matches from files that match all patterns")),
743                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
744                   N_("show parse tree for grep expression"),
745                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
746                 OPT_GROUP(""),
747                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
748                         N_("pager"), N_("show matching files in the pager"),
749                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
750                 OPT_BOOL(0, "ext-grep", &external_grep_allowed__ignored,
751                          N_("allow calling of grep(1) (ignored by this build)")),
752                 OPT_END()
753         };
754
755         init_grep_defaults();
756         git_config(grep_cmd_config, NULL);
757         grep_init(&opt, prefix);
758
759         /*
760          * If there is no -- then the paths must exist in the working
761          * tree.  If there is no explicit pattern specified with -e or
762          * -f, we take the first unrecognized non option to be the
763          * pattern, but then what follows it must be zero or more
764          * valid refs up to the -- (if exists), and then existing
765          * paths.  If there is an explicit pattern, then the first
766          * unrecognized non option is the beginning of the refs list
767          * that continues up to the -- (if exists), and then paths.
768          */
769         argc = parse_options(argc, argv, prefix, options, grep_usage,
770                              PARSE_OPT_KEEP_DASHDASH |
771                              PARSE_OPT_STOP_AT_NON_OPTION);
772         grep_commit_pattern_type(pattern_type_arg, &opt);
773
774         if (use_index && !startup_info->have_repository) {
775                 int fallback = 0;
776                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
777                 if (fallback)
778                         use_index = 0;
779                 else
780                         /* die the same way as if we did it at the beginning */
781                         setup_git_directory();
782         }
783
784         /*
785          * skip a -- separator; we know it cannot be
786          * separating revisions from pathnames if
787          * we haven't even had any patterns yet
788          */
789         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
790                 argv++;
791                 argc--;
792         }
793
794         /* First unrecognized non-option token */
795         if (argc > 0 && !opt.pattern_list) {
796                 append_grep_pattern(&opt, argv[0], "command line", 0,
797                                     GREP_PATTERN);
798                 argv++;
799                 argc--;
800         }
801
802         if (show_in_pager == default_pager)
803                 show_in_pager = git_pager(1);
804         if (show_in_pager) {
805                 opt.color = 0;
806                 opt.name_only = 1;
807                 opt.null_following_name = 1;
808                 opt.output_priv = &path_list;
809                 opt.output = append_path;
810                 string_list_append(&path_list, show_in_pager);
811         }
812
813         if (!opt.pattern_list)
814                 die(_("no pattern given."));
815         if (!opt.fixed && opt.ignore_case)
816                 opt.regflags |= REG_ICASE;
817
818         compile_grep_patterns(&opt);
819
820         /* Check revs and then paths */
821         for (i = 0; i < argc; i++) {
822                 const char *arg = argv[i];
823                 unsigned char sha1[20];
824                 struct object_context oc;
825                 /* Is it a rev? */
826                 if (!get_sha1_with_context(arg, 0, sha1, &oc)) {
827                         struct object *object = parse_object_or_die(sha1, arg);
828                         if (!seen_dashdash)
829                                 verify_non_filename(prefix, arg);
830                         add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
831                         continue;
832                 }
833                 if (!strcmp(arg, "--")) {
834                         i++;
835                         seen_dashdash = 1;
836                 }
837                 break;
838         }
839
840 #ifndef NO_PTHREADS
841         if (list.nr || cached || show_in_pager)
842                 num_threads = 0;
843         else if (num_threads == 0)
844                 num_threads = GREP_NUM_THREADS_DEFAULT;
845         else if (num_threads < 0)
846                 die(_("invalid number of threads specified (%d)"), num_threads);
847 #else
848         num_threads = 0;
849 #endif
850
851 #ifndef NO_PTHREADS
852         if (num_threads) {
853                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
854                     && (opt.pre_context || opt.post_context ||
855                         opt.file_break || opt.funcbody))
856                         skip_first_line = 1;
857                 start_threads(&opt);
858         }
859 #endif
860
861         /* The rest are paths */
862         if (!seen_dashdash) {
863                 int j;
864                 for (j = i; j < argc; j++)
865                         verify_filename(prefix, argv[j], j == i);
866         }
867
868         parse_pathspec(&pathspec, 0,
869                        PATHSPEC_PREFER_CWD |
870                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
871                        prefix, argv + i);
872         pathspec.max_depth = opt.max_depth;
873         pathspec.recursive = 1;
874
875         if (show_in_pager && (cached || list.nr))
876                 die(_("--open-files-in-pager only works on the worktree"));
877
878         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
879                 const char *pager = path_list.items[0].string;
880                 int len = strlen(pager);
881
882                 if (len > 4 && is_dir_sep(pager[len - 5]))
883                         pager += len - 4;
884
885                 if (opt.ignore_case && !strcmp("less", pager))
886                         string_list_append(&path_list, "-I");
887
888                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
889                         struct strbuf buf = STRBUF_INIT;
890                         strbuf_addf(&buf, "+/%s%s",
891                                         strcmp("less", pager) ? "" : "*",
892                                         opt.pattern_list->pattern);
893                         string_list_append(&path_list, buf.buf);
894                         strbuf_detach(&buf, NULL);
895                 }
896         }
897
898         if (!show_in_pager && !opt.status_only)
899                 setup_pager();
900
901         if (!use_index && (untracked || cached))
902                 die(_("--cached or --untracked cannot be used with --no-index."));
903
904         if (!use_index || untracked) {
905                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
906                 if (list.nr)
907                         die(_("--no-index or --untracked cannot be used with revs."));
908                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
909         } else if (0 <= opt_exclude) {
910                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
911         } else if (!list.nr) {
912                 if (!cached)
913                         setup_work_tree();
914
915                 hit = grep_cache(&opt, &pathspec, cached);
916         } else {
917                 if (cached)
918                         die(_("both --cached and trees are given."));
919                 hit = grep_objects(&opt, &pathspec, &list);
920         }
921
922         if (num_threads)
923                 hit |= wait_all();
924         if (hit && show_in_pager)
925                 run_pager(&opt, prefix);
926         free_grep_patterns(&opt);
927         return !hit;
928 }