grep: clean up num_threads handling
[git] / builtin / grep.c
1 /*
2  * Builtin "git grep"
3  *
4  * Copyright (c) 2006 Junio C Hamano
5  */
6 #include "cache.h"
7 #include "repository.h"
8 #include "config.h"
9 #include "blob.h"
10 #include "tree.h"
11 #include "commit.h"
12 #include "tag.h"
13 #include "tree-walk.h"
14 #include "builtin.h"
15 #include "parse-options.h"
16 #include "string-list.h"
17 #include "run-command.h"
18 #include "userdiff.h"
19 #include "grep.h"
20 #include "quote.h"
21 #include "dir.h"
22 #include "pathspec.h"
23 #include "submodule.h"
24 #include "submodule-config.h"
25 #include "object-store.h"
26
27 static char const * const grep_usage[] = {
28         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
29         NULL
30 };
31
32 static int recurse_submodules;
33
34 #define GREP_NUM_THREADS_DEFAULT 8
35 static int num_threads;
36
37 static pthread_t *threads;
38
39 /* We use one producer thread and THREADS consumer
40  * threads. The producer adds struct work_items to 'todo' and the
41  * consumers pick work items from the same array.
42  */
43 struct work_item {
44         struct grep_source source;
45         char done;
46         struct strbuf out;
47 };
48
49 /* In the range [todo_done, todo_start) in 'todo' we have work_items
50  * that have been or are processed by a consumer thread. We haven't
51  * written the result for these to stdout yet.
52  *
53  * The work_items in [todo_start, todo_end) are waiting to be picked
54  * up by a consumer thread.
55  *
56  * The ranges are modulo TODO_SIZE.
57  */
58 #define TODO_SIZE 128
59 static struct work_item todo[TODO_SIZE];
60 static int todo_start;
61 static int todo_end;
62 static int todo_done;
63
64 /* Has all work items been added? */
65 static int all_work_added;
66
67 /* This lock protects all the variables above. */
68 static pthread_mutex_t grep_mutex;
69
70 static inline void grep_lock(void)
71 {
72         pthread_mutex_lock(&grep_mutex);
73 }
74
75 static inline void grep_unlock(void)
76 {
77         pthread_mutex_unlock(&grep_mutex);
78 }
79
80 /* Signalled when a new work_item is added to todo. */
81 static pthread_cond_t cond_add;
82
83 /* Signalled when the result from one work_item is written to
84  * stdout.
85  */
86 static pthread_cond_t cond_write;
87
88 /* Signalled when we are finished with everything. */
89 static pthread_cond_t cond_result;
90
91 static int skip_first_line;
92
93 static void add_work(struct grep_opt *opt, const struct grep_source *gs)
94 {
95         grep_lock();
96
97         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
98                 pthread_cond_wait(&cond_write, &grep_mutex);
99         }
100
101         todo[todo_end].source = *gs;
102         if (opt->binary != GREP_BINARY_TEXT)
103                 grep_source_load_driver(&todo[todo_end].source,
104                                         opt->repo->index);
105         todo[todo_end].done = 0;
106         strbuf_reset(&todo[todo_end].out);
107         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
108
109         pthread_cond_signal(&cond_add);
110         grep_unlock();
111 }
112
113 static struct work_item *get_work(void)
114 {
115         struct work_item *ret;
116
117         grep_lock();
118         while (todo_start == todo_end && !all_work_added) {
119                 pthread_cond_wait(&cond_add, &grep_mutex);
120         }
121
122         if (todo_start == todo_end && all_work_added) {
123                 ret = NULL;
124         } else {
125                 ret = &todo[todo_start];
126                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
127         }
128         grep_unlock();
129         return ret;
130 }
131
132 static void work_done(struct work_item *w)
133 {
134         int old_done;
135
136         grep_lock();
137         w->done = 1;
138         old_done = todo_done;
139         for(; todo[todo_done].done && todo_done != todo_start;
140             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
141                 w = &todo[todo_done];
142                 if (w->out.len) {
143                         const char *p = w->out.buf;
144                         size_t len = w->out.len;
145
146                         /* Skip the leading hunk mark of the first file. */
147                         if (skip_first_line) {
148                                 while (len) {
149                                         len--;
150                                         if (*p++ == '\n')
151                                                 break;
152                                 }
153                                 skip_first_line = 0;
154                         }
155
156                         write_or_die(1, p, len);
157                 }
158                 grep_source_clear(&w->source);
159         }
160
161         if (old_done != todo_done)
162                 pthread_cond_signal(&cond_write);
163
164         if (all_work_added && todo_done == todo_end)
165                 pthread_cond_signal(&cond_result);
166
167         grep_unlock();
168 }
169
170 static void *run(void *arg)
171 {
172         int hit = 0;
173         struct grep_opt *opt = arg;
174
175         while (1) {
176                 struct work_item *w = get_work();
177                 if (!w)
178                         break;
179
180                 opt->output_priv = w;
181                 hit |= grep_source(opt, &w->source);
182                 grep_source_clear_data(&w->source);
183                 work_done(w);
184         }
185         free_grep_patterns(arg);
186         free(arg);
187
188         return (void*) (intptr_t) hit;
189 }
190
191 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
192 {
193         struct work_item *w = opt->output_priv;
194         strbuf_add(&w->out, buf, size);
195 }
196
197 static void start_threads(struct grep_opt *opt)
198 {
199         int i;
200
201         pthread_mutex_init(&grep_mutex, NULL);
202         pthread_mutex_init(&grep_read_mutex, NULL);
203         pthread_mutex_init(&grep_attr_mutex, NULL);
204         pthread_cond_init(&cond_add, NULL);
205         pthread_cond_init(&cond_write, NULL);
206         pthread_cond_init(&cond_result, NULL);
207         grep_use_locks = 1;
208
209         for (i = 0; i < ARRAY_SIZE(todo); i++) {
210                 strbuf_init(&todo[i].out, 0);
211         }
212
213         threads = xcalloc(num_threads, sizeof(*threads));
214         for (i = 0; i < num_threads; i++) {
215                 int err;
216                 struct grep_opt *o = grep_opt_dup(opt);
217                 o->output = strbuf_out;
218                 if (i)
219                         o->debug = 0;
220                 compile_grep_patterns(o);
221                 err = pthread_create(&threads[i], NULL, run, o);
222
223                 if (err)
224                         die(_("grep: failed to create thread: %s"),
225                             strerror(err));
226         }
227 }
228
229 static int wait_all(void)
230 {
231         int hit = 0;
232         int i;
233
234         if (!HAVE_THREADS)
235                 BUG("Never call this function unless you have started threads");
236
237         grep_lock();
238         all_work_added = 1;
239
240         /* Wait until all work is done. */
241         while (todo_done != todo_end)
242                 pthread_cond_wait(&cond_result, &grep_mutex);
243
244         /* Wake up all the consumer threads so they can see that there
245          * is no more work to do.
246          */
247         pthread_cond_broadcast(&cond_add);
248         grep_unlock();
249
250         for (i = 0; i < num_threads; i++) {
251                 void *h;
252                 pthread_join(threads[i], &h);
253                 hit |= (int) (intptr_t) h;
254         }
255
256         free(threads);
257
258         pthread_mutex_destroy(&grep_mutex);
259         pthread_mutex_destroy(&grep_read_mutex);
260         pthread_mutex_destroy(&grep_attr_mutex);
261         pthread_cond_destroy(&cond_add);
262         pthread_cond_destroy(&cond_write);
263         pthread_cond_destroy(&cond_result);
264         grep_use_locks = 0;
265
266         return hit;
267 }
268
269 static int grep_cmd_config(const char *var, const char *value, void *cb)
270 {
271         int st = grep_config(var, value, cb);
272         if (git_color_default_config(var, value, cb) < 0)
273                 st = -1;
274
275         if (!strcmp(var, "grep.threads")) {
276                 num_threads = git_config_int(var, value);
277                 if (num_threads < 0)
278                         die(_("invalid number of threads specified (%d) for %s"),
279                             num_threads, var);
280                 else if (!HAVE_THREADS && num_threads > 1) {
281                         /*
282                          * TRANSLATORS: %s is the configuration
283                          * variable for tweaking threads, currently
284                          * grep.threads
285                          */
286                         warning(_("no threads support, ignoring %s"), var);
287                         num_threads = 1;
288                 }
289         }
290
291         if (!strcmp(var, "submodule.recurse"))
292                 recurse_submodules = git_config_bool(var, value);
293
294         return st;
295 }
296
297 static void *lock_and_read_oid_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
298 {
299         void *data;
300
301         grep_read_lock();
302         data = read_object_file(oid, type, size);
303         grep_read_unlock();
304         return data;
305 }
306
307 static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
308                      const char *filename, int tree_name_len,
309                      const char *path)
310 {
311         struct strbuf pathbuf = STRBUF_INIT;
312         struct grep_source gs;
313
314         if (opt->relative && opt->prefix_length) {
315                 quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
316                 strbuf_insert(&pathbuf, 0, filename, tree_name_len);
317         } else {
318                 strbuf_addstr(&pathbuf, filename);
319         }
320
321         grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
322         strbuf_release(&pathbuf);
323
324         if (num_threads > 1) {
325                 /*
326                  * add_work() copies gs and thus assumes ownership of
327                  * its fields, so do not call grep_source_clear()
328                  */
329                 add_work(opt, &gs);
330                 return 0;
331         } else {
332                 int hit;
333
334                 hit = grep_source(opt, &gs);
335
336                 grep_source_clear(&gs);
337                 return hit;
338         }
339 }
340
341 static int grep_file(struct grep_opt *opt, const char *filename)
342 {
343         struct strbuf buf = STRBUF_INIT;
344         struct grep_source gs;
345
346         if (opt->relative && opt->prefix_length)
347                 quote_path_relative(filename, opt->prefix, &buf);
348         else
349                 strbuf_addstr(&buf, filename);
350
351         grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
352         strbuf_release(&buf);
353
354         if (num_threads > 1) {
355                 /*
356                  * add_work() copies gs and thus assumes ownership of
357                  * its fields, so do not call grep_source_clear()
358                  */
359                 add_work(opt, &gs);
360                 return 0;
361         } else {
362                 int hit;
363
364                 hit = grep_source(opt, &gs);
365
366                 grep_source_clear(&gs);
367                 return hit;
368         }
369 }
370
371 static void append_path(struct grep_opt *opt, const void *data, size_t len)
372 {
373         struct string_list *path_list = opt->output_priv;
374
375         if (len == 1 && *(const char *)data == '\0')
376                 return;
377         string_list_append(path_list, xstrndup(data, len));
378 }
379
380 static void run_pager(struct grep_opt *opt, const char *prefix)
381 {
382         struct string_list *path_list = opt->output_priv;
383         struct child_process child = CHILD_PROCESS_INIT;
384         int i, status;
385
386         for (i = 0; i < path_list->nr; i++)
387                 argv_array_push(&child.args, path_list->items[i].string);
388         child.dir = prefix;
389         child.use_shell = 1;
390
391         status = run_command(&child);
392         if (status)
393                 exit(status);
394 }
395
396 static int grep_cache(struct grep_opt *opt, struct repository *repo,
397                       const struct pathspec *pathspec, int cached);
398 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
399                      struct tree_desc *tree, struct strbuf *base, int tn_len,
400                      int check_attr, struct repository *repo);
401
402 static int grep_submodule(struct grep_opt *opt, struct repository *superproject,
403                           const struct pathspec *pathspec,
404                           const struct object_id *oid,
405                           const char *filename, const char *path)
406 {
407         struct repository submodule;
408         int hit;
409
410         if (!is_submodule_active(superproject, path))
411                 return 0;
412
413         if (repo_submodule_init(&submodule, superproject, path))
414                 return 0;
415
416         repo_read_gitmodules(&submodule);
417
418         /*
419          * NEEDSWORK: This adds the submodule's object directory to the list of
420          * alternates for the single in-memory object store.  This has some bad
421          * consequences for memory (processed objects will never be freed) and
422          * performance (this increases the number of pack files git has to pay
423          * attention to, to the sum of the number of pack files in all the
424          * repositories processed so far).  This can be removed once the object
425          * store is no longer global and instead is a member of the repository
426          * object.
427          */
428         grep_read_lock();
429         add_to_alternates_memory(submodule.objects->objectdir);
430         grep_read_unlock();
431
432         if (oid) {
433                 struct object *object;
434                 struct tree_desc tree;
435                 void *data;
436                 unsigned long size;
437                 struct strbuf base = STRBUF_INIT;
438
439                 object = parse_object_or_die(oid, oid_to_hex(oid));
440
441                 grep_read_lock();
442                 data = read_object_with_reference(&object->oid, tree_type,
443                                                   &size, NULL);
444                 grep_read_unlock();
445
446                 if (!data)
447                         die(_("unable to read tree (%s)"), oid_to_hex(&object->oid));
448
449                 strbuf_addstr(&base, filename);
450                 strbuf_addch(&base, '/');
451
452                 init_tree_desc(&tree, data, size);
453                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
454                                 object->type == OBJ_COMMIT, &submodule);
455                 strbuf_release(&base);
456                 free(data);
457         } else {
458                 hit = grep_cache(opt, &submodule, pathspec, 1);
459         }
460
461         repo_clear(&submodule);
462         return hit;
463 }
464
465 static int grep_cache(struct grep_opt *opt, struct repository *repo,
466                       const struct pathspec *pathspec, int cached)
467 {
468         int hit = 0;
469         int nr;
470         struct strbuf name = STRBUF_INIT;
471         int name_base_len = 0;
472         if (repo->submodule_prefix) {
473                 name_base_len = strlen(repo->submodule_prefix);
474                 strbuf_addstr(&name, repo->submodule_prefix);
475         }
476
477         if (repo_read_index(repo) < 0)
478                 die(_("index file corrupt"));
479
480         for (nr = 0; nr < repo->index->cache_nr; nr++) {
481                 const struct cache_entry *ce = repo->index->cache[nr];
482                 strbuf_setlen(&name, name_base_len);
483                 strbuf_addstr(&name, ce->name);
484
485                 if (S_ISREG(ce->ce_mode) &&
486                     match_pathspec(repo->index, pathspec, name.buf, name.len, 0, NULL,
487                                    S_ISDIR(ce->ce_mode) ||
488                                    S_ISGITLINK(ce->ce_mode))) {
489                         /*
490                          * If CE_VALID is on, we assume worktree file and its
491                          * cache entry are identical, even if worktree file has
492                          * been modified, so use cache version instead
493                          */
494                         if (cached || (ce->ce_flags & CE_VALID) ||
495                             ce_skip_worktree(ce)) {
496                                 if (ce_stage(ce) || ce_intent_to_add(ce))
497                                         continue;
498                                 hit |= grep_oid(opt, &ce->oid, name.buf,
499                                                  0, name.buf);
500                         } else {
501                                 hit |= grep_file(opt, name.buf);
502                         }
503                 } else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
504                            submodule_path_match(repo->index, pathspec, name.buf, NULL)) {
505                         hit |= grep_submodule(opt, repo, pathspec, NULL, ce->name, ce->name);
506                 } else {
507                         continue;
508                 }
509
510                 if (ce_stage(ce)) {
511                         do {
512                                 nr++;
513                         } while (nr < repo->index->cache_nr &&
514                                  !strcmp(ce->name, repo->index->cache[nr]->name));
515                         nr--; /* compensate for loop control */
516                 }
517                 if (hit && opt->status_only)
518                         break;
519         }
520
521         strbuf_release(&name);
522         return hit;
523 }
524
525 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
526                      struct tree_desc *tree, struct strbuf *base, int tn_len,
527                      int check_attr, struct repository *repo)
528 {
529         int hit = 0;
530         enum interesting match = entry_not_interesting;
531         struct name_entry entry;
532         int old_baselen = base->len;
533         struct strbuf name = STRBUF_INIT;
534         int name_base_len = 0;
535         if (repo->submodule_prefix) {
536                 strbuf_addstr(&name, repo->submodule_prefix);
537                 name_base_len = name.len;
538         }
539
540         while (tree_entry(tree, &entry)) {
541                 int te_len = tree_entry_len(&entry);
542
543                 if (match != all_entries_interesting) {
544                         strbuf_addstr(&name, base->buf + tn_len);
545                         match = tree_entry_interesting(&entry, &name,
546                                                        0, pathspec);
547                         strbuf_setlen(&name, name_base_len);
548
549                         if (match == all_entries_not_interesting)
550                                 break;
551                         if (match == entry_not_interesting)
552                                 continue;
553                 }
554
555                 strbuf_add(base, entry.path, te_len);
556
557                 if (S_ISREG(entry.mode)) {
558                         hit |= grep_oid(opt, entry.oid, base->buf, tn_len,
559                                          check_attr ? base->buf + tn_len : NULL);
560                 } else if (S_ISDIR(entry.mode)) {
561                         enum object_type type;
562                         struct tree_desc sub;
563                         void *data;
564                         unsigned long size;
565
566                         data = lock_and_read_oid_file(entry.oid, &type, &size);
567                         if (!data)
568                                 die(_("unable to read tree (%s)"),
569                                     oid_to_hex(entry.oid));
570
571                         strbuf_addch(base, '/');
572                         init_tree_desc(&sub, data, size);
573                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
574                                          check_attr, repo);
575                         free(data);
576                 } else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
577                         hit |= grep_submodule(opt, repo, pathspec, entry.oid,
578                                               base->buf, base->buf + tn_len);
579                 }
580
581                 strbuf_setlen(base, old_baselen);
582
583                 if (hit && opt->status_only)
584                         break;
585         }
586
587         strbuf_release(&name);
588         return hit;
589 }
590
591 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
592                        struct object *obj, const char *name, const char *path)
593 {
594         if (obj->type == OBJ_BLOB)
595                 return grep_oid(opt, &obj->oid, name, 0, path);
596         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
597                 struct tree_desc tree;
598                 void *data;
599                 unsigned long size;
600                 struct strbuf base;
601                 int hit, len;
602
603                 grep_read_lock();
604                 data = read_object_with_reference(&obj->oid, tree_type,
605                                                   &size, NULL);
606                 grep_read_unlock();
607
608                 if (!data)
609                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
610
611                 len = name ? strlen(name) : 0;
612                 strbuf_init(&base, PATH_MAX + len + 1);
613                 if (len) {
614                         strbuf_add(&base, name, len);
615                         strbuf_addch(&base, ':');
616                 }
617                 init_tree_desc(&tree, data, size);
618                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
619                                 obj->type == OBJ_COMMIT, the_repository);
620                 strbuf_release(&base);
621                 free(data);
622                 return hit;
623         }
624         die(_("unable to grep from object of type %s"), type_name(obj->type));
625 }
626
627 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
628                         const struct object_array *list)
629 {
630         unsigned int i;
631         int hit = 0;
632         const unsigned int nr = list->nr;
633
634         for (i = 0; i < nr; i++) {
635                 struct object *real_obj;
636                 real_obj = deref_tag(the_repository, list->objects[i].item,
637                                      NULL, 0);
638
639                 /* load the gitmodules file for this rev */
640                 if (recurse_submodules) {
641                         submodule_free(the_repository);
642                         gitmodules_config_oid(&real_obj->oid);
643                 }
644                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
645                                 list->objects[i].path)) {
646                         hit = 1;
647                         if (opt->status_only)
648                                 break;
649                 }
650         }
651         return hit;
652 }
653
654 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
655                           int exc_std, int use_index)
656 {
657         struct dir_struct dir;
658         int i, hit = 0;
659
660         memset(&dir, 0, sizeof(dir));
661         if (!use_index)
662                 dir.flags |= DIR_NO_GITLINKS;
663         if (exc_std)
664                 setup_standard_excludes(&dir);
665
666         fill_directory(&dir, &the_index, pathspec);
667         for (i = 0; i < dir.nr; i++) {
668                 if (!dir_path_match(&the_index, dir.entries[i], pathspec, 0, NULL))
669                         continue;
670                 hit |= grep_file(opt, dir.entries[i]->name);
671                 if (hit && opt->status_only)
672                         break;
673         }
674         return hit;
675 }
676
677 static int context_callback(const struct option *opt, const char *arg,
678                             int unset)
679 {
680         struct grep_opt *grep_opt = opt->value;
681         int value;
682         const char *endp;
683
684         if (unset) {
685                 grep_opt->pre_context = grep_opt->post_context = 0;
686                 return 0;
687         }
688         value = strtol(arg, (char **)&endp, 10);
689         if (*endp) {
690                 return error(_("switch `%c' expects a numerical value"),
691                              opt->short_name);
692         }
693         grep_opt->pre_context = grep_opt->post_context = value;
694         return 0;
695 }
696
697 static int file_callback(const struct option *opt, const char *arg, int unset)
698 {
699         struct grep_opt *grep_opt = opt->value;
700         int from_stdin = !strcmp(arg, "-");
701         FILE *patterns;
702         int lno = 0;
703         struct strbuf sb = STRBUF_INIT;
704
705         patterns = from_stdin ? stdin : fopen(arg, "r");
706         if (!patterns)
707                 die_errno(_("cannot open '%s'"), arg);
708         while (strbuf_getline(&sb, patterns) == 0) {
709                 /* ignore empty line like grep does */
710                 if (sb.len == 0)
711                         continue;
712
713                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
714                                 GREP_PATTERN);
715         }
716         if (!from_stdin)
717                 fclose(patterns);
718         strbuf_release(&sb);
719         return 0;
720 }
721
722 static int not_callback(const struct option *opt, const char *arg, int unset)
723 {
724         struct grep_opt *grep_opt = opt->value;
725         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
726         return 0;
727 }
728
729 static int and_callback(const struct option *opt, const char *arg, int unset)
730 {
731         struct grep_opt *grep_opt = opt->value;
732         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
733         return 0;
734 }
735
736 static int open_callback(const struct option *opt, const char *arg, int unset)
737 {
738         struct grep_opt *grep_opt = opt->value;
739         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
740         return 0;
741 }
742
743 static int close_callback(const struct option *opt, const char *arg, int unset)
744 {
745         struct grep_opt *grep_opt = opt->value;
746         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
747         return 0;
748 }
749
750 static int pattern_callback(const struct option *opt, const char *arg,
751                             int unset)
752 {
753         struct grep_opt *grep_opt = opt->value;
754         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
755         return 0;
756 }
757
758 int cmd_grep(int argc, const char **argv, const char *prefix)
759 {
760         int hit = 0;
761         int cached = 0, untracked = 0, opt_exclude = -1;
762         int seen_dashdash = 0;
763         int external_grep_allowed__ignored;
764         const char *show_in_pager = NULL, *default_pager = "dummy";
765         struct grep_opt opt;
766         struct object_array list = OBJECT_ARRAY_INIT;
767         struct pathspec pathspec;
768         struct string_list path_list = STRING_LIST_INIT_NODUP;
769         int i;
770         int dummy;
771         int use_index = 1;
772         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
773         int allow_revs;
774
775         struct option options[] = {
776                 OPT_BOOL(0, "cached", &cached,
777                         N_("search in index instead of in the work tree")),
778                 OPT_NEGBIT(0, "no-index", &use_index,
779                          N_("find in contents not managed by git"), 1),
780                 OPT_BOOL(0, "untracked", &untracked,
781                         N_("search in both tracked and untracked files")),
782                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
783                             N_("ignore files specified via '.gitignore'"), 1),
784                 OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
785                          N_("recursively search in each submodule")),
786                 OPT_GROUP(""),
787                 OPT_BOOL('v', "invert-match", &opt.invert,
788                         N_("show non-matching lines")),
789                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
790                         N_("case insensitive matching")),
791                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
792                         N_("match patterns only at word boundaries")),
793                 OPT_SET_INT('a', "text", &opt.binary,
794                         N_("process binary files as text"), GREP_BINARY_TEXT),
795                 OPT_SET_INT('I', NULL, &opt.binary,
796                         N_("don't match patterns in binary files"),
797                         GREP_BINARY_NOMATCH),
798                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
799                          N_("process binary files with textconv filters")),
800                 OPT_SET_INT('r', "recursive", &opt.max_depth,
801                             N_("search in subdirectories (default)"), -1),
802                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
803                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
804                         NULL, 1 },
805                 OPT_GROUP(""),
806                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
807                             N_("use extended POSIX regular expressions"),
808                             GREP_PATTERN_TYPE_ERE),
809                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
810                             N_("use basic POSIX regular expressions (default)"),
811                             GREP_PATTERN_TYPE_BRE),
812                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
813                             N_("interpret patterns as fixed strings"),
814                             GREP_PATTERN_TYPE_FIXED),
815                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
816                             N_("use Perl-compatible regular expressions"),
817                             GREP_PATTERN_TYPE_PCRE),
818                 OPT_GROUP(""),
819                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
820                 OPT_BOOL(0, "column", &opt.columnnum, N_("show column number of first match")),
821                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
822                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
823                 OPT_NEGBIT(0, "full-name", &opt.relative,
824                         N_("show filenames relative to top directory"), 1),
825                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
826                         N_("show only filenames instead of matching lines")),
827                 OPT_BOOL(0, "name-only", &opt.name_only,
828                         N_("synonym for --files-with-matches")),
829                 OPT_BOOL('L', "files-without-match",
830                         &opt.unmatch_name_only,
831                         N_("show only the names of files without match")),
832                 OPT_BOOL_F('z', "null", &opt.null_following_name,
833                            N_("print NUL after filenames"),
834                            PARSE_OPT_NOCOMPLETE),
835                 OPT_BOOL('o', "only-matching", &opt.only_matching,
836                         N_("show only matching parts of a line")),
837                 OPT_BOOL('c', "count", &opt.count,
838                         N_("show the number of matches instead of matching lines")),
839                 OPT__COLOR(&opt.color, N_("highlight matches")),
840                 OPT_BOOL(0, "break", &opt.file_break,
841                         N_("print empty line between matches from different files")),
842                 OPT_BOOL(0, "heading", &opt.heading,
843                         N_("show filename only once above matches from same file")),
844                 OPT_GROUP(""),
845                 OPT_CALLBACK('C', "context", &opt, N_("n"),
846                         N_("show <n> context lines before and after matches"),
847                         context_callback),
848                 OPT_INTEGER('B', "before-context", &opt.pre_context,
849                         N_("show <n> context lines before matches")),
850                 OPT_INTEGER('A', "after-context", &opt.post_context,
851                         N_("show <n> context lines after matches")),
852                 OPT_INTEGER(0, "threads", &num_threads,
853                         N_("use <n> worker threads")),
854                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
855                         context_callback),
856                 OPT_BOOL('p', "show-function", &opt.funcname,
857                         N_("show a line with the function name before matches")),
858                 OPT_BOOL('W', "function-context", &opt.funcbody,
859                         N_("show the surrounding function")),
860                 OPT_GROUP(""),
861                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
862                         N_("read patterns from file"), file_callback),
863                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
864                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
865                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
866                   N_("combine patterns specified with -e"),
867                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
868                 OPT_BOOL(0, "or", &dummy, ""),
869                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
870                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
871                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
872                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
873                   open_callback },
874                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
875                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
876                   close_callback },
877                 OPT__QUIET(&opt.status_only,
878                            N_("indicate hit with exit status without output")),
879                 OPT_BOOL(0, "all-match", &opt.all_match,
880                         N_("show only matches from files that match all patterns")),
881                 OPT_SET_INT_F(0, "debug", &opt.debug,
882                               N_("show parse tree for grep expression"),
883                               1, PARSE_OPT_HIDDEN),
884                 OPT_GROUP(""),
885                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
886                         N_("pager"), N_("show matching files in the pager"),
887                         PARSE_OPT_OPTARG | PARSE_OPT_NOCOMPLETE,
888                         NULL, (intptr_t)default_pager },
889                 OPT_BOOL_F(0, "ext-grep", &external_grep_allowed__ignored,
890                            N_("allow calling of grep(1) (ignored by this build)"),
891                            PARSE_OPT_NOCOMPLETE),
892                 OPT_END()
893         };
894
895         init_grep_defaults(the_repository);
896         git_config(grep_cmd_config, NULL);
897         grep_init(&opt, the_repository, prefix);
898
899         /*
900          * If there is no -- then the paths must exist in the working
901          * tree.  If there is no explicit pattern specified with -e or
902          * -f, we take the first unrecognized non option to be the
903          * pattern, but then what follows it must be zero or more
904          * valid refs up to the -- (if exists), and then existing
905          * paths.  If there is an explicit pattern, then the first
906          * unrecognized non option is the beginning of the refs list
907          * that continues up to the -- (if exists), and then paths.
908          */
909         argc = parse_options(argc, argv, prefix, options, grep_usage,
910                              PARSE_OPT_KEEP_DASHDASH |
911                              PARSE_OPT_STOP_AT_NON_OPTION);
912         grep_commit_pattern_type(pattern_type_arg, &opt);
913
914         if (use_index && !startup_info->have_repository) {
915                 int fallback = 0;
916                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
917                 if (fallback)
918                         use_index = 0;
919                 else
920                         /* die the same way as if we did it at the beginning */
921                         setup_git_directory();
922         }
923
924         /*
925          * skip a -- separator; we know it cannot be
926          * separating revisions from pathnames if
927          * we haven't even had any patterns yet
928          */
929         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
930                 argv++;
931                 argc--;
932         }
933
934         /* First unrecognized non-option token */
935         if (argc > 0 && !opt.pattern_list) {
936                 append_grep_pattern(&opt, argv[0], "command line", 0,
937                                     GREP_PATTERN);
938                 argv++;
939                 argc--;
940         }
941
942         if (show_in_pager == default_pager)
943                 show_in_pager = git_pager(1);
944         if (show_in_pager) {
945                 opt.color = 0;
946                 opt.name_only = 1;
947                 opt.null_following_name = 1;
948                 opt.output_priv = &path_list;
949                 opt.output = append_path;
950                 string_list_append(&path_list, show_in_pager);
951         }
952
953         if (!opt.pattern_list)
954                 die(_("no pattern given"));
955
956         /* --only-matching has no effect with --invert. */
957         if (opt.invert)
958                 opt.only_matching = 0;
959
960         /*
961          * We have to find "--" in a separate pass, because its presence
962          * influences how we will parse arguments that come before it.
963          */
964         for (i = 0; i < argc; i++) {
965                 if (!strcmp(argv[i], "--")) {
966                         seen_dashdash = 1;
967                         break;
968                 }
969         }
970
971         /*
972          * Resolve any rev arguments. If we have a dashdash, then everything up
973          * to it must resolve as a rev. If not, then we stop at the first
974          * non-rev and assume everything else is a path.
975          */
976         allow_revs = use_index && !untracked;
977         for (i = 0; i < argc; i++) {
978                 const char *arg = argv[i];
979                 struct object_id oid;
980                 struct object_context oc;
981                 struct object *object;
982
983                 if (!strcmp(arg, "--")) {
984                         i++;
985                         break;
986                 }
987
988                 if (!allow_revs) {
989                         if (seen_dashdash)
990                                 die(_("--no-index or --untracked cannot be used with revs"));
991                         break;
992                 }
993
994                 if (get_oid_with_context(arg, GET_OID_RECORD_PATH,
995                                          &oid, &oc)) {
996                         if (seen_dashdash)
997                                 die(_("unable to resolve revision: %s"), arg);
998                         break;
999                 }
1000
1001                 object = parse_object_or_die(&oid, arg);
1002                 if (!seen_dashdash)
1003                         verify_non_filename(prefix, arg);
1004                 add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
1005                 free(oc.path);
1006         }
1007
1008         /*
1009          * Anything left over is presumed to be a path. But in the non-dashdash
1010          * "do what I mean" case, we verify and complain when that isn't true.
1011          */
1012         if (!seen_dashdash) {
1013                 int j;
1014                 for (j = i; j < argc; j++)
1015                         verify_filename(prefix, argv[j], j == i && allow_revs);
1016         }
1017
1018         parse_pathspec(&pathspec, 0,
1019                        PATHSPEC_PREFER_CWD |
1020                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
1021                        prefix, argv + i);
1022         pathspec.max_depth = opt.max_depth;
1023         pathspec.recursive = 1;
1024         pathspec.recurse_submodules = !!recurse_submodules;
1025
1026         if (list.nr || cached || show_in_pager) {
1027                 if (num_threads > 1)
1028                         warning(_("invalid option combination, ignoring --threads"));
1029                 num_threads = 1;
1030         } else if (!HAVE_THREADS && num_threads > 1) {
1031                 warning(_("no threads support, ignoring --threads"));
1032                 num_threads = 1;
1033         } else if (num_threads < 0)
1034                 die(_("invalid number of threads specified (%d)"), num_threads);
1035         else if (num_threads == 0)
1036                 num_threads = HAVE_THREADS ? GREP_NUM_THREADS_DEFAULT : 1;
1037
1038         if (num_threads > 1) {
1039                 if (!HAVE_THREADS)
1040                         BUG("Somebody got num_threads calculation wrong!");
1041                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
1042                     && (opt.pre_context || opt.post_context ||
1043                         opt.file_break || opt.funcbody))
1044                         skip_first_line = 1;
1045                 start_threads(&opt);
1046         } else {
1047                 /*
1048                  * The compiled patterns on the main path are only
1049                  * used when not using threading. Otherwise
1050                  * start_threads() above calls compile_grep_patterns()
1051                  * for each thread.
1052                  */
1053                 compile_grep_patterns(&opt);
1054         }
1055
1056         if (show_in_pager && (cached || list.nr))
1057                 die(_("--open-files-in-pager only works on the worktree"));
1058
1059         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
1060                 const char *pager = path_list.items[0].string;
1061                 int len = strlen(pager);
1062
1063                 if (len > 4 && is_dir_sep(pager[len - 5]))
1064                         pager += len - 4;
1065
1066                 if (opt.ignore_case && !strcmp("less", pager))
1067                         string_list_append(&path_list, "-I");
1068
1069                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
1070                         struct strbuf buf = STRBUF_INIT;
1071                         strbuf_addf(&buf, "+/%s%s",
1072                                         strcmp("less", pager) ? "" : "*",
1073                                         opt.pattern_list->pattern);
1074                         string_list_append(&path_list, buf.buf);
1075                         strbuf_detach(&buf, NULL);
1076                 }
1077         }
1078
1079         if (recurse_submodules && (!use_index || untracked))
1080                 die(_("option not supported with --recurse-submodules"));
1081
1082         if (!show_in_pager && !opt.status_only)
1083                 setup_pager();
1084
1085         if (!use_index && (untracked || cached))
1086                 die(_("--cached or --untracked cannot be used with --no-index"));
1087
1088         if (!use_index || untracked) {
1089                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
1090                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
1091         } else if (0 <= opt_exclude) {
1092                 die(_("--[no-]exclude-standard cannot be used for tracked contents"));
1093         } else if (!list.nr) {
1094                 if (!cached)
1095                         setup_work_tree();
1096
1097                 hit = grep_cache(&opt, the_repository, &pathspec, cached);
1098         } else {
1099                 if (cached)
1100                         die(_("both --cached and trees are given"));
1101
1102                 hit = grep_objects(&opt, &pathspec, &list);
1103         }
1104
1105         if (num_threads > 1)
1106                 hit |= wait_all();
1107         if (hit && show_in_pager)
1108                 run_pager(&opt, prefix);
1109         clear_pathspec(&pathspec);
1110         free_grep_patterns(&opt);
1111         return !hit;
1112 }