xsize_t: avoid implementation defined behavior when len < 0
[git] / builtin / grep.c
1 /*
2  * Builtin "git grep"
3  *
4  * Copyright (c) 2006 Junio C Hamano
5  */
6 #define USE_THE_INDEX_COMPATIBILITY_MACROS
7 #include "cache.h"
8 #include "repository.h"
9 #include "config.h"
10 #include "blob.h"
11 #include "tree.h"
12 #include "commit.h"
13 #include "tag.h"
14 #include "tree-walk.h"
15 #include "builtin.h"
16 #include "parse-options.h"
17 #include "string-list.h"
18 #include "run-command.h"
19 #include "userdiff.h"
20 #include "grep.h"
21 #include "quote.h"
22 #include "dir.h"
23 #include "pathspec.h"
24 #include "submodule.h"
25 #include "submodule-config.h"
26 #include "object-store.h"
27 #include "packfile.h"
28
29 static char const * const grep_usage[] = {
30         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
31         NULL
32 };
33
34 static int recurse_submodules;
35
36 static int num_threads;
37
38 static pthread_t *threads;
39
40 /* We use one producer thread and THREADS consumer
41  * threads. The producer adds struct work_items to 'todo' and the
42  * consumers pick work items from the same array.
43  */
44 struct work_item {
45         struct grep_source source;
46         char done;
47         struct strbuf out;
48 };
49
50 /* In the range [todo_done, todo_start) in 'todo' we have work_items
51  * that have been or are processed by a consumer thread. We haven't
52  * written the result for these to stdout yet.
53  *
54  * The work_items in [todo_start, todo_end) are waiting to be picked
55  * up by a consumer thread.
56  *
57  * The ranges are modulo TODO_SIZE.
58  */
59 #define TODO_SIZE 128
60 static struct work_item todo[TODO_SIZE];
61 static int todo_start;
62 static int todo_end;
63 static int todo_done;
64
65 /* Has all work items been added? */
66 static int all_work_added;
67
68 /* This lock protects all the variables above. */
69 static pthread_mutex_t grep_mutex;
70
71 static inline void grep_lock(void)
72 {
73         pthread_mutex_lock(&grep_mutex);
74 }
75
76 static inline void grep_unlock(void)
77 {
78         pthread_mutex_unlock(&grep_mutex);
79 }
80
81 /* Signalled when a new work_item is added to todo. */
82 static pthread_cond_t cond_add;
83
84 /* Signalled when the result from one work_item is written to
85  * stdout.
86  */
87 static pthread_cond_t cond_write;
88
89 /* Signalled when we are finished with everything. */
90 static pthread_cond_t cond_result;
91
92 static int skip_first_line;
93
94 static void add_work(struct grep_opt *opt, struct grep_source *gs)
95 {
96         if (opt->binary != GREP_BINARY_TEXT)
97                 grep_source_load_driver(gs, opt->repo->index);
98
99         grep_lock();
100
101         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
102                 pthread_cond_wait(&cond_write, &grep_mutex);
103         }
104
105         todo[todo_end].source = *gs;
106         todo[todo_end].done = 0;
107         strbuf_reset(&todo[todo_end].out);
108         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
109
110         pthread_cond_signal(&cond_add);
111         grep_unlock();
112 }
113
114 static struct work_item *get_work(void)
115 {
116         struct work_item *ret;
117
118         grep_lock();
119         while (todo_start == todo_end && !all_work_added) {
120                 pthread_cond_wait(&cond_add, &grep_mutex);
121         }
122
123         if (todo_start == todo_end && all_work_added) {
124                 ret = NULL;
125         } else {
126                 ret = &todo[todo_start];
127                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
128         }
129         grep_unlock();
130         return ret;
131 }
132
133 static void work_done(struct work_item *w)
134 {
135         int old_done;
136
137         grep_lock();
138         w->done = 1;
139         old_done = todo_done;
140         for(; todo[todo_done].done && todo_done != todo_start;
141             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
142                 w = &todo[todo_done];
143                 if (w->out.len) {
144                         const char *p = w->out.buf;
145                         size_t len = w->out.len;
146
147                         /* Skip the leading hunk mark of the first file. */
148                         if (skip_first_line) {
149                                 while (len) {
150                                         len--;
151                                         if (*p++ == '\n')
152                                                 break;
153                                 }
154                                 skip_first_line = 0;
155                         }
156
157                         write_or_die(1, p, len);
158                 }
159                 grep_source_clear(&w->source);
160         }
161
162         if (old_done != todo_done)
163                 pthread_cond_signal(&cond_write);
164
165         if (all_work_added && todo_done == todo_end)
166                 pthread_cond_signal(&cond_result);
167
168         grep_unlock();
169 }
170
171 static void *run(void *arg)
172 {
173         int hit = 0;
174         struct grep_opt *opt = arg;
175
176         while (1) {
177                 struct work_item *w = get_work();
178                 if (!w)
179                         break;
180
181                 opt->output_priv = w;
182                 hit |= grep_source(opt, &w->source);
183                 grep_source_clear_data(&w->source);
184                 work_done(w);
185         }
186         free_grep_patterns(arg);
187         free(arg);
188
189         return (void*) (intptr_t) hit;
190 }
191
192 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
193 {
194         struct work_item *w = opt->output_priv;
195         strbuf_add(&w->out, buf, size);
196 }
197
198 static void start_threads(struct grep_opt *opt)
199 {
200         int i;
201
202         pthread_mutex_init(&grep_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         enable_obj_read_lock();
209
210         for (i = 0; i < ARRAY_SIZE(todo); i++) {
211                 strbuf_init(&todo[i].out, 0);
212         }
213
214         CALLOC_ARRAY(threads, num_threads);
215         for (i = 0; i < num_threads; i++) {
216                 int err;
217                 struct grep_opt *o = grep_opt_dup(opt);
218                 o->output = strbuf_out;
219                 compile_grep_patterns(o);
220                 err = pthread_create(&threads[i], NULL, run, o);
221
222                 if (err)
223                         die(_("grep: failed to create thread: %s"),
224                             strerror(err));
225         }
226 }
227
228 static int wait_all(void)
229 {
230         int hit = 0;
231         int i;
232
233         if (!HAVE_THREADS)
234                 BUG("Never call this function unless you have started threads");
235
236         grep_lock();
237         all_work_added = 1;
238
239         /* Wait until all work is done. */
240         while (todo_done != todo_end)
241                 pthread_cond_wait(&cond_result, &grep_mutex);
242
243         /* Wake up all the consumer threads so they can see that there
244          * is no more work to do.
245          */
246         pthread_cond_broadcast(&cond_add);
247         grep_unlock();
248
249         for (i = 0; i < num_threads; i++) {
250                 void *h;
251                 pthread_join(threads[i], &h);
252                 hit |= (int) (intptr_t) h;
253         }
254
255         free(threads);
256
257         pthread_mutex_destroy(&grep_mutex);
258         pthread_mutex_destroy(&grep_attr_mutex);
259         pthread_cond_destroy(&cond_add);
260         pthread_cond_destroy(&cond_write);
261         pthread_cond_destroy(&cond_result);
262         grep_use_locks = 0;
263         disable_obj_read_lock();
264
265         return hit;
266 }
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                 else if (!HAVE_THREADS && num_threads > 1) {
280                         /*
281                          * TRANSLATORS: %s is the configuration
282                          * variable for tweaking threads, currently
283                          * grep.threads
284                          */
285                         warning(_("no threads support, ignoring %s"), var);
286                         num_threads = 1;
287                 }
288         }
289
290         if (!strcmp(var, "submodule.recurse"))
291                 recurse_submodules = git_config_bool(var, value);
292
293         return st;
294 }
295
296 static void grep_source_name(struct grep_opt *opt, const char *filename,
297                              int tree_name_len, struct strbuf *out)
298 {
299         strbuf_reset(out);
300
301         if (opt->null_following_name) {
302                 if (opt->relative && opt->prefix_length) {
303                         struct strbuf rel_buf = STRBUF_INIT;
304                         const char *rel_name =
305                                 relative_path(filename + tree_name_len,
306                                               opt->prefix, &rel_buf);
307
308                         if (tree_name_len)
309                                 strbuf_add(out, filename, tree_name_len);
310
311                         strbuf_addstr(out, rel_name);
312                         strbuf_release(&rel_buf);
313                 } else {
314                         strbuf_addstr(out, filename);
315                 }
316                 return;
317         }
318
319         if (opt->relative && opt->prefix_length)
320                 quote_path(filename + tree_name_len, opt->prefix, out, 0);
321         else
322                 quote_c_style(filename + tree_name_len, out, NULL, 0);
323
324         if (tree_name_len)
325                 strbuf_insert(out, 0, filename, tree_name_len);
326 }
327
328 static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
329                      const char *filename, int tree_name_len,
330                      const char *path)
331 {
332         struct strbuf pathbuf = STRBUF_INIT;
333         struct grep_source gs;
334
335         grep_source_name(opt, filename, tree_name_len, &pathbuf);
336         grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
337         strbuf_release(&pathbuf);
338
339         if (num_threads > 1) {
340                 /*
341                  * add_work() copies gs and thus assumes ownership of
342                  * its fields, so do not call grep_source_clear()
343                  */
344                 add_work(opt, &gs);
345                 return 0;
346         } else {
347                 int hit;
348
349                 hit = grep_source(opt, &gs);
350
351                 grep_source_clear(&gs);
352                 return hit;
353         }
354 }
355
356 static int grep_file(struct grep_opt *opt, const char *filename)
357 {
358         struct strbuf buf = STRBUF_INIT;
359         struct grep_source gs;
360
361         grep_source_name(opt, filename, 0, &buf);
362         grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
363         strbuf_release(&buf);
364
365         if (num_threads > 1) {
366                 /*
367                  * add_work() copies gs and thus assumes ownership of
368                  * its fields, so do not call grep_source_clear()
369                  */
370                 add_work(opt, &gs);
371                 return 0;
372         } else {
373                 int hit;
374
375                 hit = grep_source(opt, &gs);
376
377                 grep_source_clear(&gs);
378                 return hit;
379         }
380 }
381
382 static void append_path(struct grep_opt *opt, const void *data, size_t len)
383 {
384         struct string_list *path_list = opt->output_priv;
385
386         if (len == 1 && *(const char *)data == '\0')
387                 return;
388         string_list_append(path_list, xstrndup(data, len));
389 }
390
391 static void run_pager(struct grep_opt *opt, const char *prefix)
392 {
393         struct string_list *path_list = opt->output_priv;
394         struct child_process child = CHILD_PROCESS_INIT;
395         int i, status;
396
397         for (i = 0; i < path_list->nr; i++)
398                 strvec_push(&child.args, path_list->items[i].string);
399         child.dir = prefix;
400         child.use_shell = 1;
401
402         status = run_command(&child);
403         if (status)
404                 exit(status);
405 }
406
407 static int grep_cache(struct grep_opt *opt,
408                       const struct pathspec *pathspec, int cached);
409 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
410                      struct tree_desc *tree, struct strbuf *base, int tn_len,
411                      int check_attr);
412
413 static int grep_submodule(struct grep_opt *opt,
414                           const struct pathspec *pathspec,
415                           const struct object_id *oid,
416                           const char *filename, const char *path, int cached)
417 {
418         struct repository subrepo;
419         struct repository *superproject = opt->repo;
420         const struct submodule *sub;
421         struct grep_opt subopt;
422         int hit;
423
424         sub = submodule_from_path(superproject, &null_oid, path);
425
426         if (!is_submodule_active(superproject, path))
427                 return 0;
428
429         if (repo_submodule_init(&subrepo, superproject, sub))
430                 return 0;
431
432         /*
433          * NEEDSWORK: repo_read_gitmodules() might call
434          * add_to_alternates_memory() via config_from_gitmodules(). This
435          * operation causes a race condition with concurrent object readings
436          * performed by the worker threads. That's why we need obj_read_lock()
437          * here. It should be removed once it's no longer necessary to add the
438          * subrepo's odbs to the in-memory alternates list.
439          */
440         obj_read_lock();
441         repo_read_gitmodules(&subrepo, 0);
442
443         /*
444          * NEEDSWORK: This adds the submodule's object directory to the list of
445          * alternates for the single in-memory object store.  This has some bad
446          * consequences for memory (processed objects will never be freed) and
447          * performance (this increases the number of pack files git has to pay
448          * attention to, to the sum of the number of pack files in all the
449          * repositories processed so far).  This can be removed once the object
450          * store is no longer global and instead is a member of the repository
451          * object.
452          */
453         add_to_alternates_memory(subrepo.objects->odb->path);
454         obj_read_unlock();
455
456         memcpy(&subopt, opt, sizeof(subopt));
457         subopt.repo = &subrepo;
458
459         if (oid) {
460                 struct object *object;
461                 struct tree_desc tree;
462                 void *data;
463                 unsigned long size;
464                 struct strbuf base = STRBUF_INIT;
465
466                 obj_read_lock();
467                 object = parse_object_or_die(oid, NULL);
468                 obj_read_unlock();
469                 data = read_object_with_reference(&subrepo,
470                                                   &object->oid, tree_type,
471                                                   &size, NULL);
472                 if (!data)
473                         die(_("unable to read tree (%s)"), oid_to_hex(&object->oid));
474
475                 strbuf_addstr(&base, filename);
476                 strbuf_addch(&base, '/');
477
478                 init_tree_desc(&tree, data, size);
479                 hit = grep_tree(&subopt, pathspec, &tree, &base, base.len,
480                                 object->type == OBJ_COMMIT);
481                 strbuf_release(&base);
482                 free(data);
483         } else {
484                 hit = grep_cache(&subopt, pathspec, cached);
485         }
486
487         repo_clear(&subrepo);
488         return hit;
489 }
490
491 static int grep_cache(struct grep_opt *opt,
492                       const struct pathspec *pathspec, int cached)
493 {
494         struct repository *repo = opt->repo;
495         int hit = 0;
496         int nr;
497         struct strbuf name = STRBUF_INIT;
498         int name_base_len = 0;
499         if (repo->submodule_prefix) {
500                 name_base_len = strlen(repo->submodule_prefix);
501                 strbuf_addstr(&name, repo->submodule_prefix);
502         }
503
504         if (repo_read_index(repo) < 0)
505                 die(_("index file corrupt"));
506
507         for (nr = 0; nr < repo->index->cache_nr; nr++) {
508                 const struct cache_entry *ce = repo->index->cache[nr];
509
510                 if (!cached && ce_skip_worktree(ce))
511                         continue;
512
513                 strbuf_setlen(&name, name_base_len);
514                 strbuf_addstr(&name, ce->name);
515
516                 if (S_ISREG(ce->ce_mode) &&
517                     match_pathspec(repo->index, pathspec, name.buf, name.len, 0, NULL,
518                                    S_ISDIR(ce->ce_mode) ||
519                                    S_ISGITLINK(ce->ce_mode))) {
520                         /*
521                          * If CE_VALID is on, we assume worktree file and its
522                          * cache entry are identical, even if worktree file has
523                          * been modified, so use cache version instead
524                          */
525                         if (cached || (ce->ce_flags & CE_VALID)) {
526                                 if (ce_stage(ce) || ce_intent_to_add(ce))
527                                         continue;
528                                 hit |= grep_oid(opt, &ce->oid, name.buf,
529                                                  0, name.buf);
530                         } else {
531                                 hit |= grep_file(opt, name.buf);
532                         }
533                 } else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
534                            submodule_path_match(repo->index, pathspec, name.buf, NULL)) {
535                         hit |= grep_submodule(opt, pathspec, NULL, ce->name,
536                                               ce->name, cached);
537                 } else {
538                         continue;
539                 }
540
541                 if (ce_stage(ce)) {
542                         do {
543                                 nr++;
544                         } while (nr < repo->index->cache_nr &&
545                                  !strcmp(ce->name, repo->index->cache[nr]->name));
546                         nr--; /* compensate for loop control */
547                 }
548                 if (hit && opt->status_only)
549                         break;
550         }
551
552         strbuf_release(&name);
553         return hit;
554 }
555
556 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
557                      struct tree_desc *tree, struct strbuf *base, int tn_len,
558                      int check_attr)
559 {
560         struct repository *repo = opt->repo;
561         int hit = 0;
562         enum interesting match = entry_not_interesting;
563         struct name_entry entry;
564         int old_baselen = base->len;
565         struct strbuf name = STRBUF_INIT;
566         int name_base_len = 0;
567         if (repo->submodule_prefix) {
568                 strbuf_addstr(&name, repo->submodule_prefix);
569                 name_base_len = name.len;
570         }
571
572         while (tree_entry(tree, &entry)) {
573                 int te_len = tree_entry_len(&entry);
574
575                 if (match != all_entries_interesting) {
576                         strbuf_addstr(&name, base->buf + tn_len);
577                         match = tree_entry_interesting(repo->index,
578                                                        &entry, &name,
579                                                        0, pathspec);
580                         strbuf_setlen(&name, name_base_len);
581
582                         if (match == all_entries_not_interesting)
583                                 break;
584                         if (match == entry_not_interesting)
585                                 continue;
586                 }
587
588                 strbuf_add(base, entry.path, te_len);
589
590                 if (S_ISREG(entry.mode)) {
591                         hit |= grep_oid(opt, &entry.oid, base->buf, tn_len,
592                                          check_attr ? base->buf + tn_len : NULL);
593                 } else if (S_ISDIR(entry.mode)) {
594                         enum object_type type;
595                         struct tree_desc sub;
596                         void *data;
597                         unsigned long size;
598
599                         data = read_object_file(&entry.oid, &type, &size);
600                         if (!data)
601                                 die(_("unable to read tree (%s)"),
602                                     oid_to_hex(&entry.oid));
603
604                         strbuf_addch(base, '/');
605                         init_tree_desc(&sub, data, size);
606                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
607                                          check_attr);
608                         free(data);
609                 } else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
610                         hit |= grep_submodule(opt, pathspec, &entry.oid,
611                                               base->buf, base->buf + tn_len,
612                                               1); /* ignored */
613                 }
614
615                 strbuf_setlen(base, old_baselen);
616
617                 if (hit && opt->status_only)
618                         break;
619         }
620
621         strbuf_release(&name);
622         return hit;
623 }
624
625 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
626                        struct object *obj, const char *name, const char *path)
627 {
628         if (obj->type == OBJ_BLOB)
629                 return grep_oid(opt, &obj->oid, name, 0, path);
630         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
631                 struct tree_desc tree;
632                 void *data;
633                 unsigned long size;
634                 struct strbuf base;
635                 int hit, len;
636
637                 data = read_object_with_reference(opt->repo,
638                                                   &obj->oid, tree_type,
639                                                   &size, NULL);
640                 if (!data)
641                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
642
643                 len = name ? strlen(name) : 0;
644                 strbuf_init(&base, PATH_MAX + len + 1);
645                 if (len) {
646                         strbuf_add(&base, name, len);
647                         strbuf_addch(&base, ':');
648                 }
649                 init_tree_desc(&tree, data, size);
650                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
651                                 obj->type == OBJ_COMMIT);
652                 strbuf_release(&base);
653                 free(data);
654                 return hit;
655         }
656         die(_("unable to grep from object of type %s"), type_name(obj->type));
657 }
658
659 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
660                         const struct object_array *list)
661 {
662         unsigned int i;
663         int hit = 0;
664         const unsigned int nr = list->nr;
665
666         for (i = 0; i < nr; i++) {
667                 struct object *real_obj;
668
669                 obj_read_lock();
670                 real_obj = deref_tag(opt->repo, list->objects[i].item,
671                                      NULL, 0);
672                 obj_read_unlock();
673
674                 if (!real_obj) {
675                         char hex[GIT_MAX_HEXSZ + 1];
676                         const char *name = list->objects[i].name;
677
678                         if (!name) {
679                                 oid_to_hex_r(hex, &list->objects[i].item->oid);
680                                 name = hex;
681                         }
682                         die(_("invalid object '%s' given."), name);
683                 }
684
685                 /* load the gitmodules file for this rev */
686                 if (recurse_submodules) {
687                         submodule_free(opt->repo);
688                         obj_read_lock();
689                         gitmodules_config_oid(&real_obj->oid);
690                         obj_read_unlock();
691                 }
692                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
693                                 list->objects[i].path)) {
694                         hit = 1;
695                         if (opt->status_only)
696                                 break;
697                 }
698         }
699         return hit;
700 }
701
702 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
703                           int exc_std, int use_index)
704 {
705         struct dir_struct dir;
706         int i, hit = 0;
707
708         dir_init(&dir);
709         if (!use_index)
710                 dir.flags |= DIR_NO_GITLINKS;
711         if (exc_std)
712                 setup_standard_excludes(&dir);
713
714         fill_directory(&dir, opt->repo->index, pathspec);
715         for (i = 0; i < dir.nr; i++) {
716                 hit |= grep_file(opt, dir.entries[i]->name);
717                 if (hit && opt->status_only)
718                         break;
719         }
720         dir_clear(&dir);
721         return hit;
722 }
723
724 static int context_callback(const struct option *opt, const char *arg,
725                             int unset)
726 {
727         struct grep_opt *grep_opt = opt->value;
728         int value;
729         const char *endp;
730
731         if (unset) {
732                 grep_opt->pre_context = grep_opt->post_context = 0;
733                 return 0;
734         }
735         value = strtol(arg, (char **)&endp, 10);
736         if (*endp) {
737                 return error(_("switch `%c' expects a numerical value"),
738                              opt->short_name);
739         }
740         grep_opt->pre_context = grep_opt->post_context = value;
741         return 0;
742 }
743
744 static int file_callback(const struct option *opt, const char *arg, int unset)
745 {
746         struct grep_opt *grep_opt = opt->value;
747         int from_stdin;
748         FILE *patterns;
749         int lno = 0;
750         struct strbuf sb = STRBUF_INIT;
751
752         BUG_ON_OPT_NEG(unset);
753
754         from_stdin = !strcmp(arg, "-");
755         patterns = from_stdin ? stdin : fopen(arg, "r");
756         if (!patterns)
757                 die_errno(_("cannot open '%s'"), arg);
758         while (strbuf_getline(&sb, patterns) == 0) {
759                 /* ignore empty line like grep does */
760                 if (sb.len == 0)
761                         continue;
762
763                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
764                                 GREP_PATTERN);
765         }
766         if (!from_stdin)
767                 fclose(patterns);
768         strbuf_release(&sb);
769         return 0;
770 }
771
772 static int not_callback(const struct option *opt, const char *arg, int unset)
773 {
774         struct grep_opt *grep_opt = opt->value;
775         BUG_ON_OPT_NEG(unset);
776         BUG_ON_OPT_ARG(arg);
777         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
778         return 0;
779 }
780
781 static int and_callback(const struct option *opt, const char *arg, int unset)
782 {
783         struct grep_opt *grep_opt = opt->value;
784         BUG_ON_OPT_NEG(unset);
785         BUG_ON_OPT_ARG(arg);
786         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
787         return 0;
788 }
789
790 static int open_callback(const struct option *opt, const char *arg, int unset)
791 {
792         struct grep_opt *grep_opt = opt->value;
793         BUG_ON_OPT_NEG(unset);
794         BUG_ON_OPT_ARG(arg);
795         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
796         return 0;
797 }
798
799 static int close_callback(const struct option *opt, const char *arg, int unset)
800 {
801         struct grep_opt *grep_opt = opt->value;
802         BUG_ON_OPT_NEG(unset);
803         BUG_ON_OPT_ARG(arg);
804         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
805         return 0;
806 }
807
808 static int pattern_callback(const struct option *opt, const char *arg,
809                             int unset)
810 {
811         struct grep_opt *grep_opt = opt->value;
812         BUG_ON_OPT_NEG(unset);
813         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
814         return 0;
815 }
816
817 int cmd_grep(int argc, const char **argv, const char *prefix)
818 {
819         int hit = 0;
820         int cached = 0, untracked = 0, opt_exclude = -1;
821         int seen_dashdash = 0;
822         int external_grep_allowed__ignored;
823         const char *show_in_pager = NULL, *default_pager = "dummy";
824         struct grep_opt opt;
825         struct object_array list = OBJECT_ARRAY_INIT;
826         struct pathspec pathspec;
827         struct string_list path_list = STRING_LIST_INIT_NODUP;
828         int i;
829         int dummy;
830         int use_index = 1;
831         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
832         int allow_revs;
833
834         struct option options[] = {
835                 OPT_BOOL(0, "cached", &cached,
836                         N_("search in index instead of in the work tree")),
837                 OPT_NEGBIT(0, "no-index", &use_index,
838                          N_("find in contents not managed by git"), 1),
839                 OPT_BOOL(0, "untracked", &untracked,
840                         N_("search in both tracked and untracked files")),
841                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
842                             N_("ignore files specified via '.gitignore'"), 1),
843                 OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
844                          N_("recursively search in each submodule")),
845                 OPT_GROUP(""),
846                 OPT_BOOL('v', "invert-match", &opt.invert,
847                         N_("show non-matching lines")),
848                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
849                         N_("case insensitive matching")),
850                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
851                         N_("match patterns only at word boundaries")),
852                 OPT_SET_INT('a', "text", &opt.binary,
853                         N_("process binary files as text"), GREP_BINARY_TEXT),
854                 OPT_SET_INT('I', NULL, &opt.binary,
855                         N_("don't match patterns in binary files"),
856                         GREP_BINARY_NOMATCH),
857                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
858                          N_("process binary files with textconv filters")),
859                 OPT_SET_INT('r', "recursive", &opt.max_depth,
860                             N_("search in subdirectories (default)"), -1),
861                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
862                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
863                         NULL, 1 },
864                 OPT_GROUP(""),
865                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
866                             N_("use extended POSIX regular expressions"),
867                             GREP_PATTERN_TYPE_ERE),
868                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
869                             N_("use basic POSIX regular expressions (default)"),
870                             GREP_PATTERN_TYPE_BRE),
871                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
872                             N_("interpret patterns as fixed strings"),
873                             GREP_PATTERN_TYPE_FIXED),
874                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
875                             N_("use Perl-compatible regular expressions"),
876                             GREP_PATTERN_TYPE_PCRE),
877                 OPT_GROUP(""),
878                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
879                 OPT_BOOL(0, "column", &opt.columnnum, N_("show column number of first match")),
880                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
881                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
882                 OPT_NEGBIT(0, "full-name", &opt.relative,
883                         N_("show filenames relative to top directory"), 1),
884                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
885                         N_("show only filenames instead of matching lines")),
886                 OPT_BOOL(0, "name-only", &opt.name_only,
887                         N_("synonym for --files-with-matches")),
888                 OPT_BOOL('L', "files-without-match",
889                         &opt.unmatch_name_only,
890                         N_("show only the names of files without match")),
891                 OPT_BOOL_F('z', "null", &opt.null_following_name,
892                            N_("print NUL after filenames"),
893                            PARSE_OPT_NOCOMPLETE),
894                 OPT_BOOL('o', "only-matching", &opt.only_matching,
895                         N_("show only matching parts of a line")),
896                 OPT_BOOL('c', "count", &opt.count,
897                         N_("show the number of matches instead of matching lines")),
898                 OPT__COLOR(&opt.color, N_("highlight matches")),
899                 OPT_BOOL(0, "break", &opt.file_break,
900                         N_("print empty line between matches from different files")),
901                 OPT_BOOL(0, "heading", &opt.heading,
902                         N_("show filename only once above matches from same file")),
903                 OPT_GROUP(""),
904                 OPT_CALLBACK('C', "context", &opt, N_("n"),
905                         N_("show <n> context lines before and after matches"),
906                         context_callback),
907                 OPT_INTEGER('B', "before-context", &opt.pre_context,
908                         N_("show <n> context lines before matches")),
909                 OPT_INTEGER('A', "after-context", &opt.post_context,
910                         N_("show <n> context lines after matches")),
911                 OPT_INTEGER(0, "threads", &num_threads,
912                         N_("use <n> worker threads")),
913                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
914                         context_callback),
915                 OPT_BOOL('p', "show-function", &opt.funcname,
916                         N_("show a line with the function name before matches")),
917                 OPT_BOOL('W', "function-context", &opt.funcbody,
918                         N_("show the surrounding function")),
919                 OPT_GROUP(""),
920                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
921                         N_("read patterns from file"), file_callback),
922                 OPT_CALLBACK_F('e', NULL, &opt, N_("pattern"),
923                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback),
924                 OPT_CALLBACK_F(0, "and", &opt, NULL,
925                         N_("combine patterns specified with -e"),
926                         PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback),
927                 OPT_BOOL(0, "or", &dummy, ""),
928                 OPT_CALLBACK_F(0, "not", &opt, NULL, "",
929                         PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback),
930                 OPT_CALLBACK_F('(', NULL, &opt, NULL, "",
931                         PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
932                         open_callback),
933                 OPT_CALLBACK_F(')', NULL, &opt, NULL, "",
934                         PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
935                         close_callback),
936                 OPT__QUIET(&opt.status_only,
937                            N_("indicate hit with exit status without output")),
938                 OPT_BOOL(0, "all-match", &opt.all_match,
939                         N_("show only matches from files that match all patterns")),
940                 OPT_GROUP(""),
941                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
942                         N_("pager"), N_("show matching files in the pager"),
943                         PARSE_OPT_OPTARG | PARSE_OPT_NOCOMPLETE,
944                         NULL, (intptr_t)default_pager },
945                 OPT_BOOL_F(0, "ext-grep", &external_grep_allowed__ignored,
946                            N_("allow calling of grep(1) (ignored by this build)"),
947                            PARSE_OPT_NOCOMPLETE),
948                 OPT_END()
949         };
950
951         git_config(grep_cmd_config, NULL);
952         grep_init(&opt, the_repository, prefix);
953
954         /*
955          * If there is no -- then the paths must exist in the working
956          * tree.  If there is no explicit pattern specified with -e or
957          * -f, we take the first unrecognized non option to be the
958          * pattern, but then what follows it must be zero or more
959          * valid refs up to the -- (if exists), and then existing
960          * paths.  If there is an explicit pattern, then the first
961          * unrecognized non option is the beginning of the refs list
962          * that continues up to the -- (if exists), and then paths.
963          */
964         argc = parse_options(argc, argv, prefix, options, grep_usage,
965                              PARSE_OPT_KEEP_DASHDASH |
966                              PARSE_OPT_STOP_AT_NON_OPTION);
967         grep_commit_pattern_type(pattern_type_arg, &opt);
968
969         if (use_index && !startup_info->have_repository) {
970                 int fallback = 0;
971                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
972                 if (fallback)
973                         use_index = 0;
974                 else
975                         /* die the same way as if we did it at the beginning */
976                         setup_git_directory();
977         }
978         /* Ignore --recurse-submodules if --no-index is given or implied */
979         if (!use_index)
980                 recurse_submodules = 0;
981
982         /*
983          * skip a -- separator; we know it cannot be
984          * separating revisions from pathnames if
985          * we haven't even had any patterns yet
986          */
987         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
988                 argv++;
989                 argc--;
990         }
991
992         /* First unrecognized non-option token */
993         if (argc > 0 && !opt.pattern_list) {
994                 append_grep_pattern(&opt, argv[0], "command line", 0,
995                                     GREP_PATTERN);
996                 argv++;
997                 argc--;
998         }
999
1000         if (show_in_pager == default_pager)
1001                 show_in_pager = git_pager(1);
1002         if (show_in_pager) {
1003                 opt.color = 0;
1004                 opt.name_only = 1;
1005                 opt.null_following_name = 1;
1006                 opt.output_priv = &path_list;
1007                 opt.output = append_path;
1008                 string_list_append(&path_list, show_in_pager);
1009         }
1010
1011         if (!opt.pattern_list)
1012                 die(_("no pattern given"));
1013
1014         /* --only-matching has no effect with --invert. */
1015         if (opt.invert)
1016                 opt.only_matching = 0;
1017
1018         /*
1019          * We have to find "--" in a separate pass, because its presence
1020          * influences how we will parse arguments that come before it.
1021          */
1022         for (i = 0; i < argc; i++) {
1023                 if (!strcmp(argv[i], "--")) {
1024                         seen_dashdash = 1;
1025                         break;
1026                 }
1027         }
1028
1029         /*
1030          * Resolve any rev arguments. If we have a dashdash, then everything up
1031          * to it must resolve as a rev. If not, then we stop at the first
1032          * non-rev and assume everything else is a path.
1033          */
1034         allow_revs = use_index && !untracked;
1035         for (i = 0; i < argc; i++) {
1036                 const char *arg = argv[i];
1037                 struct object_id oid;
1038                 struct object_context oc;
1039                 struct object *object;
1040
1041                 if (!strcmp(arg, "--")) {
1042                         i++;
1043                         break;
1044                 }
1045
1046                 if (!allow_revs) {
1047                         if (seen_dashdash)
1048                                 die(_("--no-index or --untracked cannot be used with revs"));
1049                         break;
1050                 }
1051
1052                 if (get_oid_with_context(the_repository, arg,
1053                                          GET_OID_RECORD_PATH,
1054                                          &oid, &oc)) {
1055                         if (seen_dashdash)
1056                                 die(_("unable to resolve revision: %s"), arg);
1057                         break;
1058                 }
1059
1060                 object = parse_object_or_die(&oid, arg);
1061                 if (!seen_dashdash)
1062                         verify_non_filename(prefix, arg);
1063                 add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
1064                 free(oc.path);
1065         }
1066
1067         /*
1068          * Anything left over is presumed to be a path. But in the non-dashdash
1069          * "do what I mean" case, we verify and complain when that isn't true.
1070          */
1071         if (!seen_dashdash) {
1072                 int j;
1073                 for (j = i; j < argc; j++)
1074                         verify_filename(prefix, argv[j], j == i && allow_revs);
1075         }
1076
1077         parse_pathspec(&pathspec, 0,
1078                        PATHSPEC_PREFER_CWD |
1079                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
1080                        prefix, argv + i);
1081         pathspec.max_depth = opt.max_depth;
1082         pathspec.recursive = 1;
1083         pathspec.recurse_submodules = !!recurse_submodules;
1084
1085         if (recurse_submodules && untracked)
1086                 die(_("--untracked not supported with --recurse-submodules"));
1087
1088         if (show_in_pager) {
1089                 if (num_threads > 1)
1090                         warning(_("invalid option combination, ignoring --threads"));
1091                 num_threads = 1;
1092         } else if (!HAVE_THREADS && num_threads > 1) {
1093                 warning(_("no threads support, ignoring --threads"));
1094                 num_threads = 1;
1095         } else if (num_threads < 0)
1096                 die(_("invalid number of threads specified (%d)"), num_threads);
1097         else if (num_threads == 0)
1098                 num_threads = HAVE_THREADS ? online_cpus() : 1;
1099
1100         if (num_threads > 1) {
1101                 if (!HAVE_THREADS)
1102                         BUG("Somebody got num_threads calculation wrong!");
1103                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
1104                     && (opt.pre_context || opt.post_context ||
1105                         opt.file_break || opt.funcbody))
1106                         skip_first_line = 1;
1107
1108                 /*
1109                  * Pre-read gitmodules (if not read already) and force eager
1110                  * initialization of packed_git to prevent racy lazy
1111                  * reading/initialization once worker threads are started.
1112                  */
1113                 if (recurse_submodules)
1114                         repo_read_gitmodules(the_repository, 1);
1115                 if (startup_info->have_repository)
1116                         (void)get_packed_git(the_repository);
1117
1118                 start_threads(&opt);
1119         } else {
1120                 /*
1121                  * The compiled patterns on the main path are only
1122                  * used when not using threading. Otherwise
1123                  * start_threads() above calls compile_grep_patterns()
1124                  * for each thread.
1125                  */
1126                 compile_grep_patterns(&opt);
1127         }
1128
1129         if (show_in_pager && (cached || list.nr))
1130                 die(_("--open-files-in-pager only works on the worktree"));
1131
1132         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
1133                 const char *pager = path_list.items[0].string;
1134                 int len = strlen(pager);
1135
1136                 if (len > 4 && is_dir_sep(pager[len - 5]))
1137                         pager += len - 4;
1138
1139                 if (opt.ignore_case && !strcmp("less", pager))
1140                         string_list_append(&path_list, "-I");
1141
1142                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
1143                         struct strbuf buf = STRBUF_INIT;
1144                         strbuf_addf(&buf, "+/%s%s",
1145                                         strcmp("less", pager) ? "" : "*",
1146                                         opt.pattern_list->pattern);
1147                         string_list_append(&path_list,
1148                                            strbuf_detach(&buf, NULL));
1149                 }
1150         }
1151
1152         if (!show_in_pager && !opt.status_only)
1153                 setup_pager();
1154
1155         if (!use_index && (untracked || cached))
1156                 die(_("--cached or --untracked cannot be used with --no-index"));
1157
1158         if (untracked && cached)
1159                 die(_("--untracked cannot be used with --cached"));
1160
1161         if (!use_index || untracked) {
1162                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
1163                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
1164         } else if (0 <= opt_exclude) {
1165                 die(_("--[no-]exclude-standard cannot be used for tracked contents"));
1166         } else if (!list.nr) {
1167                 if (!cached)
1168                         setup_work_tree();
1169
1170                 hit = grep_cache(&opt, &pathspec, cached);
1171         } else {
1172                 if (cached)
1173                         die(_("both --cached and trees are given"));
1174
1175                 hit = grep_objects(&opt, &pathspec, &list);
1176         }
1177
1178         if (num_threads > 1)
1179                 hit |= wait_all();
1180         if (hit && show_in_pager)
1181                 run_pager(&opt, prefix);
1182         clear_pathspec(&pathspec);
1183         free_grep_patterns(&opt);
1184         grep_destroy();
1185         return !hit;
1186 }