Merge branch 'ab/push-cas-doc-n-test'
[git] / builtin / grep.c
1 /*
2  * Builtin "git grep"
3  *
4  * Copyright (c) 2006 Junio C Hamano
5  */
6 #include "cache.h"
7 #include "blob.h"
8 #include "tree.h"
9 #include "commit.h"
10 #include "tag.h"
11 #include "tree-walk.h"
12 #include "builtin.h"
13 #include "parse-options.h"
14 #include "string-list.h"
15 #include "run-command.h"
16 #include "userdiff.h"
17 #include "grep.h"
18 #include "quote.h"
19 #include "dir.h"
20 #include "pathspec.h"
21 #include "submodule.h"
22 #include "submodule-config.h"
23
24 static char const * const grep_usage[] = {
25         N_("git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]"),
26         NULL
27 };
28
29 static const char *super_prefix;
30 static int recurse_submodules;
31 static struct argv_array submodule_options = ARGV_ARRAY_INIT;
32 static const char *parent_basename;
33
34 static int grep_submodule_launch(struct grep_opt *opt,
35                                  const struct grep_source *gs);
36
37 #define GREP_NUM_THREADS_DEFAULT 8
38 static int num_threads;
39
40 #ifndef NO_PTHREADS
41 static pthread_t *threads;
42
43 /* We use one producer thread and THREADS consumer
44  * threads. The producer adds struct work_items to 'todo' and the
45  * consumers pick work items from the same array.
46  */
47 struct work_item {
48         struct grep_source source;
49         char done;
50         struct strbuf out;
51 };
52
53 /* In the range [todo_done, todo_start) in 'todo' we have work_items
54  * that have been or are processed by a consumer thread. We haven't
55  * written the result for these to stdout yet.
56  *
57  * The work_items in [todo_start, todo_end) are waiting to be picked
58  * up by a consumer thread.
59  *
60  * The ranges are modulo TODO_SIZE.
61  */
62 #define TODO_SIZE 128
63 static struct work_item todo[TODO_SIZE];
64 static int todo_start;
65 static int todo_end;
66 static int todo_done;
67
68 /* Has all work items been added? */
69 static int all_work_added;
70
71 /* This lock protects all the variables above. */
72 static pthread_mutex_t grep_mutex;
73
74 static inline void grep_lock(void)
75 {
76         if (num_threads)
77                 pthread_mutex_lock(&grep_mutex);
78 }
79
80 static inline void grep_unlock(void)
81 {
82         if (num_threads)
83                 pthread_mutex_unlock(&grep_mutex);
84 }
85
86 /* Signalled when a new work_item is added to todo. */
87 static pthread_cond_t cond_add;
88
89 /* Signalled when the result from one work_item is written to
90  * stdout.
91  */
92 static pthread_cond_t cond_write;
93
94 /* Signalled when we are finished with everything. */
95 static pthread_cond_t cond_result;
96
97 static int skip_first_line;
98
99 static void add_work(struct grep_opt *opt, enum grep_source_type type,
100                      const char *name, const char *path, const void *id)
101 {
102         grep_lock();
103
104         while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
105                 pthread_cond_wait(&cond_write, &grep_mutex);
106         }
107
108         grep_source_init(&todo[todo_end].source, type, name, path, id);
109         if (opt->binary != GREP_BINARY_TEXT)
110                 grep_source_load_driver(&todo[todo_end].source);
111         todo[todo_end].done = 0;
112         strbuf_reset(&todo[todo_end].out);
113         todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
114
115         pthread_cond_signal(&cond_add);
116         grep_unlock();
117 }
118
119 static struct work_item *get_work(void)
120 {
121         struct work_item *ret;
122
123         grep_lock();
124         while (todo_start == todo_end && !all_work_added) {
125                 pthread_cond_wait(&cond_add, &grep_mutex);
126         }
127
128         if (todo_start == todo_end && all_work_added) {
129                 ret = NULL;
130         } else {
131                 ret = &todo[todo_start];
132                 todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
133         }
134         grep_unlock();
135         return ret;
136 }
137
138 static void work_done(struct work_item *w)
139 {
140         int old_done;
141
142         grep_lock();
143         w->done = 1;
144         old_done = todo_done;
145         for(; todo[todo_done].done && todo_done != todo_start;
146             todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
147                 w = &todo[todo_done];
148                 if (w->out.len) {
149                         const char *p = w->out.buf;
150                         size_t len = w->out.len;
151
152                         /* Skip the leading hunk mark of the first file. */
153                         if (skip_first_line) {
154                                 while (len) {
155                                         len--;
156                                         if (*p++ == '\n')
157                                                 break;
158                                 }
159                                 skip_first_line = 0;
160                         }
161
162                         write_or_die(1, p, len);
163                 }
164                 grep_source_clear(&w->source);
165         }
166
167         if (old_done != todo_done)
168                 pthread_cond_signal(&cond_write);
169
170         if (all_work_added && todo_done == todo_end)
171                 pthread_cond_signal(&cond_result);
172
173         grep_unlock();
174 }
175
176 static void *run(void *arg)
177 {
178         int hit = 0;
179         struct grep_opt *opt = arg;
180
181         while (1) {
182                 struct work_item *w = get_work();
183                 if (!w)
184                         break;
185
186                 opt->output_priv = w;
187                 if (w->source.type == GREP_SOURCE_SUBMODULE)
188                         hit |= grep_submodule_launch(opt, &w->source);
189                 else
190                         hit |= grep_source(opt, &w->source);
191                 grep_source_clear_data(&w->source);
192                 work_done(w);
193         }
194         free_grep_patterns(arg);
195         free(arg);
196
197         return (void*) (intptr_t) hit;
198 }
199
200 static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
201 {
202         struct work_item *w = opt->output_priv;
203         strbuf_add(&w->out, buf, size);
204 }
205
206 static void start_threads(struct grep_opt *opt)
207 {
208         int i;
209
210         pthread_mutex_init(&grep_mutex, NULL);
211         pthread_mutex_init(&grep_read_mutex, NULL);
212         pthread_mutex_init(&grep_attr_mutex, NULL);
213         pthread_cond_init(&cond_add, NULL);
214         pthread_cond_init(&cond_write, NULL);
215         pthread_cond_init(&cond_result, NULL);
216         grep_use_locks = 1;
217
218         for (i = 0; i < ARRAY_SIZE(todo); i++) {
219                 strbuf_init(&todo[i].out, 0);
220         }
221
222         threads = xcalloc(num_threads, sizeof(*threads));
223         for (i = 0; i < num_threads; i++) {
224                 int err;
225                 struct grep_opt *o = grep_opt_dup(opt);
226                 o->output = strbuf_out;
227                 o->debug = 0;
228                 compile_grep_patterns(o);
229                 err = pthread_create(&threads[i], NULL, run, o);
230
231                 if (err)
232                         die(_("grep: failed to create thread: %s"),
233                             strerror(err));
234         }
235 }
236
237 static int wait_all(void)
238 {
239         int hit = 0;
240         int i;
241
242         grep_lock();
243         all_work_added = 1;
244
245         /* Wait until all work is done. */
246         while (todo_done != todo_end)
247                 pthread_cond_wait(&cond_result, &grep_mutex);
248
249         /* Wake up all the consumer threads so they can see that there
250          * is no more work to do.
251          */
252         pthread_cond_broadcast(&cond_add);
253         grep_unlock();
254
255         for (i = 0; i < num_threads; i++) {
256                 void *h;
257                 pthread_join(threads[i], &h);
258                 hit |= (int) (intptr_t) h;
259         }
260
261         free(threads);
262
263         pthread_mutex_destroy(&grep_mutex);
264         pthread_mutex_destroy(&grep_read_mutex);
265         pthread_mutex_destroy(&grep_attr_mutex);
266         pthread_cond_destroy(&cond_add);
267         pthread_cond_destroy(&cond_write);
268         pthread_cond_destroy(&cond_result);
269         grep_use_locks = 0;
270
271         return hit;
272 }
273 #else /* !NO_PTHREADS */
274
275 static int wait_all(void)
276 {
277         return 0;
278 }
279 #endif
280
281 static int grep_cmd_config(const char *var, const char *value, void *cb)
282 {
283         int st = grep_config(var, value, cb);
284         if (git_color_default_config(var, value, cb) < 0)
285                 st = -1;
286
287         if (!strcmp(var, "grep.threads")) {
288                 num_threads = git_config_int(var, value);
289                 if (num_threads < 0)
290                         die(_("invalid number of threads specified (%d) for %s"),
291                             num_threads, var);
292         }
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_sha1_file(oid->hash, 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
313         if (super_prefix) {
314                 strbuf_add(&pathbuf, filename, tree_name_len);
315                 strbuf_addstr(&pathbuf, super_prefix);
316                 strbuf_addstr(&pathbuf, filename + tree_name_len);
317         } else {
318                 strbuf_addstr(&pathbuf, filename);
319         }
320
321         if (opt->relative && opt->prefix_length) {
322                 char *name = strbuf_detach(&pathbuf, NULL);
323                 quote_path_relative(name + tree_name_len, opt->prefix, &pathbuf);
324                 strbuf_insert(&pathbuf, 0, name, tree_name_len);
325                 free(name);
326         }
327
328 #ifndef NO_PTHREADS
329         if (num_threads) {
330                 add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, oid);
331                 strbuf_release(&pathbuf);
332                 return 0;
333         } else
334 #endif
335         {
336                 struct grep_source gs;
337                 int hit;
338
339                 grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, oid);
340                 strbuf_release(&pathbuf);
341                 hit = grep_source(opt, &gs);
342
343                 grep_source_clear(&gs);
344                 return hit;
345         }
346 }
347
348 static int grep_file(struct grep_opt *opt, const char *filename)
349 {
350         struct strbuf buf = STRBUF_INIT;
351
352         if (super_prefix)
353                 strbuf_addstr(&buf, super_prefix);
354         strbuf_addstr(&buf, filename);
355
356         if (opt->relative && opt->prefix_length) {
357                 char *name = strbuf_detach(&buf, NULL);
358                 quote_path_relative(name, opt->prefix, &buf);
359                 free(name);
360         }
361
362 #ifndef NO_PTHREADS
363         if (num_threads) {
364                 add_work(opt, GREP_SOURCE_FILE, buf.buf, filename, filename);
365                 strbuf_release(&buf);
366                 return 0;
367         } else
368 #endif
369         {
370                 struct grep_source gs;
371                 int hit;
372
373                 grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
374                 strbuf_release(&buf);
375                 hit = grep_source(opt, &gs);
376
377                 grep_source_clear(&gs);
378                 return hit;
379         }
380 }
381
382 static void append_path(struct grep_opt *opt, const void *data, size_t len)
383 {
384         struct string_list *path_list = opt->output_priv;
385
386         if (len == 1 && *(const char *)data == '\0')
387                 return;
388         string_list_append(path_list, xstrndup(data, len));
389 }
390
391 static void run_pager(struct grep_opt *opt, const char *prefix)
392 {
393         struct string_list *path_list = opt->output_priv;
394         struct child_process child = CHILD_PROCESS_INIT;
395         int i, status;
396
397         for (i = 0; i < path_list->nr; i++)
398                 argv_array_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 void compile_submodule_options(const struct grep_opt *opt,
408                                       const char **argv,
409                                       int cached, int untracked,
410                                       int opt_exclude, int use_index,
411                                       int pattern_type_arg)
412 {
413         struct grep_pat *pattern;
414
415         if (recurse_submodules)
416                 argv_array_push(&submodule_options, "--recurse-submodules");
417
418         if (cached)
419                 argv_array_push(&submodule_options, "--cached");
420         if (!use_index)
421                 argv_array_push(&submodule_options, "--no-index");
422         if (untracked)
423                 argv_array_push(&submodule_options, "--untracked");
424         if (opt_exclude > 0)
425                 argv_array_push(&submodule_options, "--exclude-standard");
426
427         if (opt->invert)
428                 argv_array_push(&submodule_options, "-v");
429         if (opt->ignore_case)
430                 argv_array_push(&submodule_options, "-i");
431         if (opt->word_regexp)
432                 argv_array_push(&submodule_options, "-w");
433         switch (opt->binary) {
434         case GREP_BINARY_NOMATCH:
435                 argv_array_push(&submodule_options, "-I");
436                 break;
437         case GREP_BINARY_TEXT:
438                 argv_array_push(&submodule_options, "-a");
439                 break;
440         default:
441                 break;
442         }
443         if (opt->allow_textconv)
444                 argv_array_push(&submodule_options, "--textconv");
445         if (opt->max_depth != -1)
446                 argv_array_pushf(&submodule_options, "--max-depth=%d",
447                                  opt->max_depth);
448         if (opt->linenum)
449                 argv_array_push(&submodule_options, "-n");
450         if (!opt->pathname)
451                 argv_array_push(&submodule_options, "-h");
452         if (!opt->relative)
453                 argv_array_push(&submodule_options, "--full-name");
454         if (opt->name_only)
455                 argv_array_push(&submodule_options, "-l");
456         if (opt->unmatch_name_only)
457                 argv_array_push(&submodule_options, "-L");
458         if (opt->null_following_name)
459                 argv_array_push(&submodule_options, "-z");
460         if (opt->count)
461                 argv_array_push(&submodule_options, "-c");
462         if (opt->file_break)
463                 argv_array_push(&submodule_options, "--break");
464         if (opt->heading)
465                 argv_array_push(&submodule_options, "--heading");
466         if (opt->pre_context)
467                 argv_array_pushf(&submodule_options, "--before-context=%d",
468                                  opt->pre_context);
469         if (opt->post_context)
470                 argv_array_pushf(&submodule_options, "--after-context=%d",
471                                  opt->post_context);
472         if (opt->funcname)
473                 argv_array_push(&submodule_options, "-p");
474         if (opt->funcbody)
475                 argv_array_push(&submodule_options, "-W");
476         if (opt->all_match)
477                 argv_array_push(&submodule_options, "--all-match");
478         if (opt->debug)
479                 argv_array_push(&submodule_options, "--debug");
480         if (opt->status_only)
481                 argv_array_push(&submodule_options, "-q");
482
483         switch (pattern_type_arg) {
484         case GREP_PATTERN_TYPE_BRE:
485                 argv_array_push(&submodule_options, "-G");
486                 break;
487         case GREP_PATTERN_TYPE_ERE:
488                 argv_array_push(&submodule_options, "-E");
489                 break;
490         case GREP_PATTERN_TYPE_FIXED:
491                 argv_array_push(&submodule_options, "-F");
492                 break;
493         case GREP_PATTERN_TYPE_PCRE:
494                 argv_array_push(&submodule_options, "-P");
495                 break;
496         case GREP_PATTERN_TYPE_UNSPECIFIED:
497                 break;
498         }
499
500         for (pattern = opt->pattern_list; pattern != NULL;
501              pattern = pattern->next) {
502                 switch (pattern->token) {
503                 case GREP_PATTERN:
504                         argv_array_pushf(&submodule_options, "-e%s",
505                                          pattern->pattern);
506                         break;
507                 case GREP_AND:
508                 case GREP_OPEN_PAREN:
509                 case GREP_CLOSE_PAREN:
510                 case GREP_NOT:
511                 case GREP_OR:
512                         argv_array_push(&submodule_options, pattern->pattern);
513                         break;
514                 /* BODY and HEAD are not used by git-grep */
515                 case GREP_PATTERN_BODY:
516                 case GREP_PATTERN_HEAD:
517                         break;
518                 }
519         }
520
521         /*
522          * Limit number of threads for child process to use.
523          * This is to prevent potential fork-bomb behavior of git-grep as each
524          * submodule process has its own thread pool.
525          */
526         argv_array_pushf(&submodule_options, "--threads=%d",
527                          (num_threads + 1) / 2);
528
529         /* Add Pathspecs */
530         argv_array_push(&submodule_options, "--");
531         for (; *argv; argv++)
532                 argv_array_push(&submodule_options, *argv);
533 }
534
535 /*
536  * Launch child process to grep contents of a submodule
537  */
538 static int grep_submodule_launch(struct grep_opt *opt,
539                                  const struct grep_source *gs)
540 {
541         struct child_process cp = CHILD_PROCESS_INIT;
542         int status, i;
543         const char *end_of_base;
544         const char *name;
545         struct strbuf child_output = STRBUF_INIT;
546
547         end_of_base = strchr(gs->name, ':');
548         if (gs->identifier && end_of_base)
549                 name = end_of_base + 1;
550         else
551                 name = gs->name;
552
553         prepare_submodule_repo_env(&cp.env_array);
554         argv_array_push(&cp.env_array, GIT_DIR_ENVIRONMENT);
555
556         if (opt->relative && opt->prefix_length)
557                 argv_array_pushf(&cp.env_array, "%s=%s",
558                                  GIT_TOPLEVEL_PREFIX_ENVIRONMENT,
559                                  opt->prefix);
560
561         /* Add super prefix */
562         argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
563                          super_prefix ? super_prefix : "",
564                          name);
565         argv_array_push(&cp.args, "grep");
566
567         /*
568          * Add basename of parent project
569          * When performing grep on a tree object the filename is prefixed
570          * with the object's name: 'tree-name:filename'.  In order to
571          * provide uniformity of output we want to pass the name of the
572          * parent project's object name to the submodule so the submodule can
573          * prefix its output with the parent's name and not its own SHA1.
574          */
575         if (gs->identifier && end_of_base)
576                 argv_array_pushf(&cp.args, "--parent-basename=%.*s",
577                                  (int) (end_of_base - gs->name),
578                                  gs->name);
579
580         /* Add options */
581         for (i = 0; i < submodule_options.argc; i++) {
582                 /*
583                  * If there is a tree identifier for the submodule, add the
584                  * rev after adding the submodule options but before the
585                  * pathspecs.  To do this we listen for the '--' and insert the
586                  * sha1 before pushing the '--' onto the child process argv
587                  * array.
588                  */
589                 if (gs->identifier &&
590                     !strcmp("--", submodule_options.argv[i])) {
591                         argv_array_push(&cp.args, sha1_to_hex(gs->identifier));
592                 }
593
594                 argv_array_push(&cp.args, submodule_options.argv[i]);
595         }
596
597         cp.git_cmd = 1;
598         cp.dir = gs->path;
599
600         /*
601          * Capture output to output buffer and check the return code from the
602          * child process.  A '0' indicates a hit, a '1' indicates no hit and
603          * anything else is an error.
604          */
605         status = capture_command(&cp, &child_output, 0);
606         if (status && (status != 1)) {
607                 /* flush the buffer */
608                 write_or_die(1, child_output.buf, child_output.len);
609                 die("process for submodule '%s' failed with exit code: %d",
610                     gs->name, status);
611         }
612
613         opt->output(opt, child_output.buf, child_output.len);
614         strbuf_release(&child_output);
615         /* invert the return code to make a hit equal to 1 */
616         return !status;
617 }
618
619 /*
620  * Prep grep structures for a submodule grep
621  * sha1: the sha1 of the submodule or NULL if using the working tree
622  * filename: name of the submodule including tree name of parent
623  * path: location of the submodule
624  */
625 static int grep_submodule(struct grep_opt *opt, const unsigned char *sha1,
626                           const char *filename, const char *path)
627 {
628         if (!is_submodule_initialized(path))
629                 return 0;
630         if (!is_submodule_populated_gently(path, NULL)) {
631                 /*
632                  * If searching history, check for the presense of the
633                  * submodule's gitdir before skipping the submodule.
634                  */
635                 if (sha1) {
636                         const struct submodule *sub =
637                                         submodule_from_path(null_sha1, path);
638                         if (sub)
639                                 path = git_path("modules/%s", sub->name);
640
641                         if (!(is_directory(path) && is_git_directory(path)))
642                                 return 0;
643                 } else {
644                         return 0;
645                 }
646         }
647
648 #ifndef NO_PTHREADS
649         if (num_threads) {
650                 add_work(opt, GREP_SOURCE_SUBMODULE, filename, path, sha1);
651                 return 0;
652         } else
653 #endif
654         {
655                 struct grep_source gs;
656                 int hit;
657
658                 grep_source_init(&gs, GREP_SOURCE_SUBMODULE,
659                                  filename, path, sha1);
660                 hit = grep_submodule_launch(opt, &gs);
661
662                 grep_source_clear(&gs);
663                 return hit;
664         }
665 }
666
667 static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec,
668                       int cached)
669 {
670         int hit = 0;
671         int nr;
672         struct strbuf name = STRBUF_INIT;
673         int name_base_len = 0;
674         if (super_prefix) {
675                 name_base_len = strlen(super_prefix);
676                 strbuf_addstr(&name, super_prefix);
677         }
678
679         read_cache();
680
681         for (nr = 0; nr < active_nr; nr++) {
682                 const struct cache_entry *ce = active_cache[nr];
683                 strbuf_setlen(&name, name_base_len);
684                 strbuf_addstr(&name, ce->name);
685
686                 if (S_ISREG(ce->ce_mode) &&
687                     match_pathspec(pathspec, name.buf, name.len, 0, NULL,
688                                    S_ISDIR(ce->ce_mode) ||
689                                    S_ISGITLINK(ce->ce_mode))) {
690                         /*
691                          * If CE_VALID is on, we assume worktree file and its
692                          * cache entry are identical, even if worktree file has
693                          * been modified, so use cache version instead
694                          */
695                         if (cached || (ce->ce_flags & CE_VALID) ||
696                             ce_skip_worktree(ce)) {
697                                 if (ce_stage(ce) || ce_intent_to_add(ce))
698                                         continue;
699                                 hit |= grep_oid(opt, &ce->oid, ce->name,
700                                                  0, ce->name);
701                         } else {
702                                 hit |= grep_file(opt, ce->name);
703                         }
704                 } else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
705                            submodule_path_match(pathspec, name.buf, NULL)) {
706                         hit |= grep_submodule(opt, NULL, ce->name, ce->name);
707                 } else {
708                         continue;
709                 }
710
711                 if (ce_stage(ce)) {
712                         do {
713                                 nr++;
714                         } while (nr < active_nr &&
715                                  !strcmp(ce->name, active_cache[nr]->name));
716                         nr--; /* compensate for loop control */
717                 }
718                 if (hit && opt->status_only)
719                         break;
720         }
721
722         strbuf_release(&name);
723         return hit;
724 }
725
726 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
727                      struct tree_desc *tree, struct strbuf *base, int tn_len,
728                      int check_attr)
729 {
730         int hit = 0;
731         enum interesting match = entry_not_interesting;
732         struct name_entry entry;
733         int old_baselen = base->len;
734         struct strbuf name = STRBUF_INIT;
735         int name_base_len = 0;
736         if (super_prefix) {
737                 strbuf_addstr(&name, super_prefix);
738                 name_base_len = name.len;
739         }
740
741         while (tree_entry(tree, &entry)) {
742                 int te_len = tree_entry_len(&entry);
743
744                 if (match != all_entries_interesting) {
745                         strbuf_addstr(&name, base->buf + tn_len);
746                         match = tree_entry_interesting(&entry, &name,
747                                                        0, pathspec);
748                         strbuf_setlen(&name, name_base_len);
749
750                         if (match == all_entries_not_interesting)
751                                 break;
752                         if (match == entry_not_interesting)
753                                 continue;
754                 }
755
756                 strbuf_add(base, entry.path, te_len);
757
758                 if (S_ISREG(entry.mode)) {
759                         hit |= grep_oid(opt, entry.oid, base->buf, tn_len,
760                                          check_attr ? base->buf + tn_len : NULL);
761                 } else if (S_ISDIR(entry.mode)) {
762                         enum object_type type;
763                         struct tree_desc sub;
764                         void *data;
765                         unsigned long size;
766
767                         data = lock_and_read_oid_file(entry.oid, &type, &size);
768                         if (!data)
769                                 die(_("unable to read tree (%s)"),
770                                     oid_to_hex(entry.oid));
771
772                         strbuf_addch(base, '/');
773                         init_tree_desc(&sub, data, size);
774                         hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
775                                          check_attr);
776                         free(data);
777                 } else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
778                         hit |= grep_submodule(opt, entry.oid->hash, base->buf,
779                                               base->buf + tn_len);
780                 }
781
782                 strbuf_setlen(base, old_baselen);
783
784                 if (hit && opt->status_only)
785                         break;
786         }
787
788         strbuf_release(&name);
789         return hit;
790 }
791
792 static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
793                        struct object *obj, const char *name, const char *path)
794 {
795         if (obj->type == OBJ_BLOB)
796                 return grep_oid(opt, &obj->oid, name, 0, path);
797         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
798                 struct tree_desc tree;
799                 void *data;
800                 unsigned long size;
801                 struct strbuf base;
802                 int hit, len;
803
804                 grep_read_lock();
805                 data = read_object_with_reference(obj->oid.hash, tree_type,
806                                                   &size, NULL);
807                 grep_read_unlock();
808
809                 if (!data)
810                         die(_("unable to read tree (%s)"), oid_to_hex(&obj->oid));
811
812                 /* Use parent's name as base when recursing submodules */
813                 if (recurse_submodules && parent_basename)
814                         name = parent_basename;
815
816                 len = name ? strlen(name) : 0;
817                 strbuf_init(&base, PATH_MAX + len + 1);
818                 if (len) {
819                         strbuf_add(&base, name, len);
820                         strbuf_addch(&base, ':');
821                 }
822                 init_tree_desc(&tree, data, size);
823                 hit = grep_tree(opt, pathspec, &tree, &base, base.len,
824                                 obj->type == OBJ_COMMIT);
825                 strbuf_release(&base);
826                 free(data);
827                 return hit;
828         }
829         die(_("unable to grep from object of type %s"), typename(obj->type));
830 }
831
832 static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
833                         const struct object_array *list)
834 {
835         unsigned int i;
836         int hit = 0;
837         const unsigned int nr = list->nr;
838
839         for (i = 0; i < nr; i++) {
840                 struct object *real_obj;
841                 real_obj = deref_tag(list->objects[i].item, NULL, 0);
842
843                 /* load the gitmodules file for this rev */
844                 if (recurse_submodules) {
845                         submodule_free();
846                         gitmodules_config_sha1(real_obj->oid.hash);
847                 }
848                 if (grep_object(opt, pathspec, real_obj, list->objects[i].name, list->objects[i].path)) {
849                         hit = 1;
850                         if (opt->status_only)
851                                 break;
852                 }
853         }
854         return hit;
855 }
856
857 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
858                           int exc_std, int use_index)
859 {
860         struct dir_struct dir;
861         int i, hit = 0;
862
863         memset(&dir, 0, sizeof(dir));
864         if (!use_index)
865                 dir.flags |= DIR_NO_GITLINKS;
866         if (exc_std)
867                 setup_standard_excludes(&dir);
868
869         fill_directory(&dir, pathspec);
870         for (i = 0; i < dir.nr; i++) {
871                 if (!dir_path_match(dir.entries[i], pathspec, 0, NULL))
872                         continue;
873                 hit |= grep_file(opt, dir.entries[i]->name);
874                 if (hit && opt->status_only)
875                         break;
876         }
877         return hit;
878 }
879
880 static int context_callback(const struct option *opt, const char *arg,
881                             int unset)
882 {
883         struct grep_opt *grep_opt = opt->value;
884         int value;
885         const char *endp;
886
887         if (unset) {
888                 grep_opt->pre_context = grep_opt->post_context = 0;
889                 return 0;
890         }
891         value = strtol(arg, (char **)&endp, 10);
892         if (*endp) {
893                 return error(_("switch `%c' expects a numerical value"),
894                              opt->short_name);
895         }
896         grep_opt->pre_context = grep_opt->post_context = value;
897         return 0;
898 }
899
900 static int file_callback(const struct option *opt, const char *arg, int unset)
901 {
902         struct grep_opt *grep_opt = opt->value;
903         int from_stdin = !strcmp(arg, "-");
904         FILE *patterns;
905         int lno = 0;
906         struct strbuf sb = STRBUF_INIT;
907
908         patterns = from_stdin ? stdin : fopen(arg, "r");
909         if (!patterns)
910                 die_errno(_("cannot open '%s'"), arg);
911         while (strbuf_getline(&sb, patterns) == 0) {
912                 /* ignore empty line like grep does */
913                 if (sb.len == 0)
914                         continue;
915
916                 append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
917                                 GREP_PATTERN);
918         }
919         if (!from_stdin)
920                 fclose(patterns);
921         strbuf_release(&sb);
922         return 0;
923 }
924
925 static int not_callback(const struct option *opt, const char *arg, int unset)
926 {
927         struct grep_opt *grep_opt = opt->value;
928         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
929         return 0;
930 }
931
932 static int and_callback(const struct option *opt, const char *arg, int unset)
933 {
934         struct grep_opt *grep_opt = opt->value;
935         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
936         return 0;
937 }
938
939 static int open_callback(const struct option *opt, const char *arg, int unset)
940 {
941         struct grep_opt *grep_opt = opt->value;
942         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
943         return 0;
944 }
945
946 static int close_callback(const struct option *opt, const char *arg, int unset)
947 {
948         struct grep_opt *grep_opt = opt->value;
949         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
950         return 0;
951 }
952
953 static int pattern_callback(const struct option *opt, const char *arg,
954                             int unset)
955 {
956         struct grep_opt *grep_opt = opt->value;
957         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
958         return 0;
959 }
960
961 int cmd_grep(int argc, const char **argv, const char *prefix)
962 {
963         int hit = 0;
964         int cached = 0, untracked = 0, opt_exclude = -1;
965         int seen_dashdash = 0;
966         int external_grep_allowed__ignored;
967         const char *show_in_pager = NULL, *default_pager = "dummy";
968         struct grep_opt opt;
969         struct object_array list = OBJECT_ARRAY_INIT;
970         struct pathspec pathspec;
971         struct string_list path_list = STRING_LIST_INIT_NODUP;
972         int i;
973         int dummy;
974         int use_index = 1;
975         int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
976         int allow_revs;
977
978         struct option options[] = {
979                 OPT_BOOL(0, "cached", &cached,
980                         N_("search in index instead of in the work tree")),
981                 OPT_NEGBIT(0, "no-index", &use_index,
982                          N_("find in contents not managed by git"), 1),
983                 OPT_BOOL(0, "untracked", &untracked,
984                         N_("search in both tracked and untracked files")),
985                 OPT_SET_INT(0, "exclude-standard", &opt_exclude,
986                             N_("ignore files specified via '.gitignore'"), 1),
987                 OPT_BOOL(0, "recurse-submodules", &recurse_submodules,
988                          N_("recursively search in each submodule")),
989                 OPT_STRING(0, "parent-basename", &parent_basename,
990                            N_("basename"),
991                            N_("prepend parent project's basename to output")),
992                 OPT_GROUP(""),
993                 OPT_BOOL('v', "invert-match", &opt.invert,
994                         N_("show non-matching lines")),
995                 OPT_BOOL('i', "ignore-case", &opt.ignore_case,
996                         N_("case insensitive matching")),
997                 OPT_BOOL('w', "word-regexp", &opt.word_regexp,
998                         N_("match patterns only at word boundaries")),
999                 OPT_SET_INT('a', "text", &opt.binary,
1000                         N_("process binary files as text"), GREP_BINARY_TEXT),
1001                 OPT_SET_INT('I', NULL, &opt.binary,
1002                         N_("don't match patterns in binary files"),
1003                         GREP_BINARY_NOMATCH),
1004                 OPT_BOOL(0, "textconv", &opt.allow_textconv,
1005                          N_("process binary files with textconv filters")),
1006                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
1007                         N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
1008                         NULL, 1 },
1009                 OPT_GROUP(""),
1010                 OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
1011                             N_("use extended POSIX regular expressions"),
1012                             GREP_PATTERN_TYPE_ERE),
1013                 OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
1014                             N_("use basic POSIX regular expressions (default)"),
1015                             GREP_PATTERN_TYPE_BRE),
1016                 OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
1017                             N_("interpret patterns as fixed strings"),
1018                             GREP_PATTERN_TYPE_FIXED),
1019                 OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
1020                             N_("use Perl-compatible regular expressions"),
1021                             GREP_PATTERN_TYPE_PCRE),
1022                 OPT_GROUP(""),
1023                 OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
1024                 OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
1025                 OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
1026                 OPT_NEGBIT(0, "full-name", &opt.relative,
1027                         N_("show filenames relative to top directory"), 1),
1028                 OPT_BOOL('l', "files-with-matches", &opt.name_only,
1029                         N_("show only filenames instead of matching lines")),
1030                 OPT_BOOL(0, "name-only", &opt.name_only,
1031                         N_("synonym for --files-with-matches")),
1032                 OPT_BOOL('L', "files-without-match",
1033                         &opt.unmatch_name_only,
1034                         N_("show only the names of files without match")),
1035                 OPT_BOOL('z', "null", &opt.null_following_name,
1036                         N_("print NUL after filenames")),
1037                 OPT_BOOL('c', "count", &opt.count,
1038                         N_("show the number of matches instead of matching lines")),
1039                 OPT__COLOR(&opt.color, N_("highlight matches")),
1040                 OPT_BOOL(0, "break", &opt.file_break,
1041                         N_("print empty line between matches from different files")),
1042                 OPT_BOOL(0, "heading", &opt.heading,
1043                         N_("show filename only once above matches from same file")),
1044                 OPT_GROUP(""),
1045                 OPT_CALLBACK('C', "context", &opt, N_("n"),
1046                         N_("show <n> context lines before and after matches"),
1047                         context_callback),
1048                 OPT_INTEGER('B', "before-context", &opt.pre_context,
1049                         N_("show <n> context lines before matches")),
1050                 OPT_INTEGER('A', "after-context", &opt.post_context,
1051                         N_("show <n> context lines after matches")),
1052                 OPT_INTEGER(0, "threads", &num_threads,
1053                         N_("use <n> worker threads")),
1054                 OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
1055                         context_callback),
1056                 OPT_BOOL('p', "show-function", &opt.funcname,
1057                         N_("show a line with the function name before matches")),
1058                 OPT_BOOL('W', "function-context", &opt.funcbody,
1059                         N_("show the surrounding function")),
1060                 OPT_GROUP(""),
1061                 OPT_CALLBACK('f', NULL, &opt, N_("file"),
1062                         N_("read patterns from file"), file_callback),
1063                 { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
1064                         N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
1065                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
1066                   N_("combine patterns specified with -e"),
1067                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
1068                 OPT_BOOL(0, "or", &dummy, ""),
1069                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
1070                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
1071                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
1072                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
1073                   open_callback },
1074                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
1075                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
1076                   close_callback },
1077                 OPT__QUIET(&opt.status_only,
1078                            N_("indicate hit with exit status without output")),
1079                 OPT_BOOL(0, "all-match", &opt.all_match,
1080                         N_("show only matches from files that match all patterns")),
1081                 { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
1082                   N_("show parse tree for grep expression"),
1083                   PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
1084                 OPT_GROUP(""),
1085                 { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
1086                         N_("pager"), N_("show matching files in the pager"),
1087                         PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
1088                 OPT_BOOL(0, "ext-grep", &external_grep_allowed__ignored,
1089                          N_("allow calling of grep(1) (ignored by this build)")),
1090                 OPT_END()
1091         };
1092
1093         init_grep_defaults();
1094         git_config(grep_cmd_config, NULL);
1095         grep_init(&opt, prefix);
1096         super_prefix = get_super_prefix();
1097
1098         /*
1099          * If there is no -- then the paths must exist in the working
1100          * tree.  If there is no explicit pattern specified with -e or
1101          * -f, we take the first unrecognized non option to be the
1102          * pattern, but then what follows it must be zero or more
1103          * valid refs up to the -- (if exists), and then existing
1104          * paths.  If there is an explicit pattern, then the first
1105          * unrecognized non option is the beginning of the refs list
1106          * that continues up to the -- (if exists), and then paths.
1107          */
1108         argc = parse_options(argc, argv, prefix, options, grep_usage,
1109                              PARSE_OPT_KEEP_DASHDASH |
1110                              PARSE_OPT_STOP_AT_NON_OPTION);
1111         grep_commit_pattern_type(pattern_type_arg, &opt);
1112
1113         if (use_index && !startup_info->have_repository) {
1114                 int fallback = 0;
1115                 git_config_get_bool("grep.fallbacktonoindex", &fallback);
1116                 if (fallback)
1117                         use_index = 0;
1118                 else
1119                         /* die the same way as if we did it at the beginning */
1120                         setup_git_directory();
1121         }
1122
1123         /*
1124          * skip a -- separator; we know it cannot be
1125          * separating revisions from pathnames if
1126          * we haven't even had any patterns yet
1127          */
1128         if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
1129                 argv++;
1130                 argc--;
1131         }
1132
1133         /* First unrecognized non-option token */
1134         if (argc > 0 && !opt.pattern_list) {
1135                 append_grep_pattern(&opt, argv[0], "command line", 0,
1136                                     GREP_PATTERN);
1137                 argv++;
1138                 argc--;
1139         }
1140
1141         if (show_in_pager == default_pager)
1142                 show_in_pager = git_pager(1);
1143         if (show_in_pager) {
1144                 opt.color = 0;
1145                 opt.name_only = 1;
1146                 opt.null_following_name = 1;
1147                 opt.output_priv = &path_list;
1148                 opt.output = append_path;
1149                 string_list_append(&path_list, show_in_pager);
1150         }
1151
1152         if (!opt.pattern_list)
1153                 die(_("no pattern given."));
1154         if (!opt.fixed && opt.ignore_case)
1155                 opt.regflags |= REG_ICASE;
1156
1157         compile_grep_patterns(&opt);
1158
1159         /*
1160          * We have to find "--" in a separate pass, because its presence
1161          * influences how we will parse arguments that come before it.
1162          */
1163         for (i = 0; i < argc; i++) {
1164                 if (!strcmp(argv[i], "--")) {
1165                         seen_dashdash = 1;
1166                         break;
1167                 }
1168         }
1169
1170         /*
1171          * Resolve any rev arguments. If we have a dashdash, then everything up
1172          * to it must resolve as a rev. If not, then we stop at the first
1173          * non-rev and assume everything else is a path.
1174          */
1175         allow_revs = use_index && !untracked;
1176         for (i = 0; i < argc; i++) {
1177                 const char *arg = argv[i];
1178                 struct object_id oid;
1179                 struct object_context oc;
1180                 struct object *object;
1181
1182                 if (!strcmp(arg, "--")) {
1183                         i++;
1184                         break;
1185                 }
1186
1187                 if (!allow_revs) {
1188                         if (seen_dashdash)
1189                                 die(_("--no-index or --untracked cannot be used with revs"));
1190                         break;
1191                 }
1192
1193                 if (get_sha1_with_context(arg, 0, oid.hash, &oc)) {
1194                         if (seen_dashdash)
1195                                 die(_("unable to resolve revision: %s"), arg);
1196                         break;
1197                 }
1198
1199                 object = parse_object_or_die(oid.hash, arg);
1200                 if (!seen_dashdash)
1201                         verify_non_filename(prefix, arg);
1202                 add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
1203         }
1204
1205         /*
1206          * Anything left over is presumed to be a path. But in the non-dashdash
1207          * "do what I mean" case, we verify and complain when that isn't true.
1208          */
1209         if (!seen_dashdash) {
1210                 int j;
1211                 for (j = i; j < argc; j++)
1212                         verify_filename(prefix, argv[j], j == i && allow_revs);
1213         }
1214
1215         parse_pathspec(&pathspec, 0,
1216                        PATHSPEC_PREFER_CWD |
1217                        (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
1218                        prefix, argv + i);
1219         pathspec.max_depth = opt.max_depth;
1220         pathspec.recursive = 1;
1221
1222 #ifndef NO_PTHREADS
1223         if (list.nr || cached || show_in_pager)
1224                 num_threads = 0;
1225         else if (num_threads == 0)
1226                 num_threads = GREP_NUM_THREADS_DEFAULT;
1227         else if (num_threads < 0)
1228                 die(_("invalid number of threads specified (%d)"), num_threads);
1229 #else
1230         num_threads = 0;
1231 #endif
1232
1233 #ifndef NO_PTHREADS
1234         if (num_threads) {
1235                 if (!(opt.name_only || opt.unmatch_name_only || opt.count)
1236                     && (opt.pre_context || opt.post_context ||
1237                         opt.file_break || opt.funcbody))
1238                         skip_first_line = 1;
1239                 start_threads(&opt);
1240         }
1241 #endif
1242
1243         if (recurse_submodules) {
1244                 gitmodules_config();
1245                 compile_submodule_options(&opt, argv + i, cached, untracked,
1246                                           opt_exclude, use_index,
1247                                           pattern_type_arg);
1248         }
1249
1250         if (show_in_pager && (cached || list.nr))
1251                 die(_("--open-files-in-pager only works on the worktree"));
1252
1253         if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
1254                 const char *pager = path_list.items[0].string;
1255                 int len = strlen(pager);
1256
1257                 if (len > 4 && is_dir_sep(pager[len - 5]))
1258                         pager += len - 4;
1259
1260                 if (opt.ignore_case && !strcmp("less", pager))
1261                         string_list_append(&path_list, "-I");
1262
1263                 if (!strcmp("less", pager) || !strcmp("vi", pager)) {
1264                         struct strbuf buf = STRBUF_INIT;
1265                         strbuf_addf(&buf, "+/%s%s",
1266                                         strcmp("less", pager) ? "" : "*",
1267                                         opt.pattern_list->pattern);
1268                         string_list_append(&path_list, buf.buf);
1269                         strbuf_detach(&buf, NULL);
1270                 }
1271         }
1272
1273         if (recurse_submodules && (!use_index || untracked))
1274                 die(_("option not supported with --recurse-submodules."));
1275
1276         if (!show_in_pager && !opt.status_only)
1277                 setup_pager();
1278
1279         if (!use_index && (untracked || cached))
1280                 die(_("--cached or --untracked cannot be used with --no-index."));
1281
1282         if (!use_index || untracked) {
1283                 int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
1284                 hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
1285         } else if (0 <= opt_exclude) {
1286                 die(_("--[no-]exclude-standard cannot be used for tracked contents."));
1287         } else if (!list.nr) {
1288                 if (!cached)
1289                         setup_work_tree();
1290
1291                 hit = grep_cache(&opt, &pathspec, cached);
1292         } else {
1293                 if (cached)
1294                         die(_("both --cached and trees are given."));
1295                 hit = grep_objects(&opt, &pathspec, &list);
1296         }
1297
1298         if (num_threads)
1299                 hit |= wait_all();
1300         if (hit && show_in_pager)
1301                 run_pager(&opt, prefix);
1302         clear_pathspec(&pathspec);
1303         free_grep_patterns(&opt);
1304         return !hit;
1305 }