rev-list: move bisect related code into its own file
[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 "grep.h"
14
15 #ifndef NO_EXTERNAL_GREP
16 #ifdef __unix__
17 #define NO_EXTERNAL_GREP 0
18 #else
19 #define NO_EXTERNAL_GREP 1
20 #endif
21 #endif
22
23 static int builtin_grep;
24
25 static int grep_config(const char *var, const char *value, void *cb)
26 {
27         struct grep_opt *opt = cb;
28
29         if (!strcmp(var, "grep.color") || !strcmp(var, "color.grep")) {
30                 opt->color = git_config_colorbool(var, value, -1);
31                 return 0;
32         }
33         if (!strcmp(var, "grep.color.external") ||
34             !strcmp(var, "color.grep.external")) {
35                 return git_config_string(&(opt->color_external), var, value);
36         }
37         if (!strcmp(var, "grep.color.match") ||
38             !strcmp(var, "color.grep.match")) {
39                 if (!value)
40                         return config_error_nonbool(var);
41                 color_parse(value, var, opt->color_match);
42                 return 0;
43         }
44         return git_color_default_config(var, value, cb);
45 }
46
47 /*
48  * git grep pathspecs are somewhat different from diff-tree pathspecs;
49  * pathname wildcards are allowed.
50  */
51 static int pathspec_matches(const char **paths, const char *name)
52 {
53         int namelen, i;
54         if (!paths || !*paths)
55                 return 1;
56         namelen = strlen(name);
57         for (i = 0; paths[i]; i++) {
58                 const char *match = paths[i];
59                 int matchlen = strlen(match);
60                 const char *cp, *meta;
61
62                 if (!matchlen ||
63                     ((matchlen <= namelen) &&
64                      !strncmp(name, match, matchlen) &&
65                      (match[matchlen-1] == '/' ||
66                       name[matchlen] == '\0' || name[matchlen] == '/')))
67                         return 1;
68                 if (!fnmatch(match, name, 0))
69                         return 1;
70                 if (name[namelen-1] != '/')
71                         continue;
72
73                 /* We are being asked if the directory ("name") is worth
74                  * descending into.
75                  *
76                  * Find the longest leading directory name that does
77                  * not have metacharacter in the pathspec; the name
78                  * we are looking at must overlap with that directory.
79                  */
80                 for (cp = match, meta = NULL; cp - match < matchlen; cp++) {
81                         char ch = *cp;
82                         if (ch == '*' || ch == '[' || ch == '?') {
83                                 meta = cp;
84                                 break;
85                         }
86                 }
87                 if (!meta)
88                         meta = cp; /* fully literal */
89
90                 if (namelen <= meta - match) {
91                         /* Looking at "Documentation/" and
92                          * the pattern says "Documentation/howto/", or
93                          * "Documentation/diff*.txt".  The name we
94                          * have should match prefix.
95                          */
96                         if (!memcmp(match, name, namelen))
97                                 return 1;
98                         continue;
99                 }
100
101                 if (meta - match < namelen) {
102                         /* Looking at "Documentation/howto/" and
103                          * the pattern says "Documentation/h*";
104                          * match up to "Do.../h"; this avoids descending
105                          * into "Documentation/technical/".
106                          */
107                         if (!memcmp(match, name, meta - match))
108                                 return 1;
109                         continue;
110                 }
111         }
112         return 0;
113 }
114
115 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
116 {
117         unsigned long size;
118         char *data;
119         enum object_type type;
120         char *to_free = NULL;
121         int hit;
122
123         data = read_sha1_file(sha1, &type, &size);
124         if (!data) {
125                 error("'%s': unable to read %s", name, sha1_to_hex(sha1));
126                 return 0;
127         }
128         if (opt->relative && opt->prefix_length) {
129                 static char name_buf[PATH_MAX];
130                 char *cp;
131                 int name_len = strlen(name) - opt->prefix_length + 1;
132
133                 if (!tree_name_len)
134                         name += opt->prefix_length;
135                 else {
136                         if (ARRAY_SIZE(name_buf) <= name_len)
137                                 cp = to_free = xmalloc(name_len);
138                         else
139                                 cp = name_buf;
140                         memcpy(cp, name, tree_name_len);
141                         strcpy(cp + tree_name_len,
142                                name + tree_name_len + opt->prefix_length);
143                         name = cp;
144                 }
145         }
146         hit = grep_buffer(opt, name, data, size);
147         free(data);
148         free(to_free);
149         return hit;
150 }
151
152 static int grep_file(struct grep_opt *opt, const char *filename)
153 {
154         struct stat st;
155         int i;
156         char *data;
157         size_t sz;
158
159         if (lstat(filename, &st) < 0) {
160         err_ret:
161                 if (errno != ENOENT)
162                         error("'%s': %s", filename, strerror(errno));
163                 return 0;
164         }
165         if (!st.st_size)
166                 return 0; /* empty file -- no grep hit */
167         if (!S_ISREG(st.st_mode))
168                 return 0;
169         sz = xsize_t(st.st_size);
170         i = open(filename, O_RDONLY);
171         if (i < 0)
172                 goto err_ret;
173         data = xmalloc(sz + 1);
174         if (st.st_size != read_in_full(i, data, sz)) {
175                 error("'%s': short read %s", filename, strerror(errno));
176                 close(i);
177                 free(data);
178                 return 0;
179         }
180         close(i);
181         if (opt->relative && opt->prefix_length)
182                 filename += opt->prefix_length;
183         i = grep_buffer(opt, filename, data, sz);
184         free(data);
185         return i;
186 }
187
188 #if !NO_EXTERNAL_GREP
189 static int exec_grep(int argc, const char **argv)
190 {
191         pid_t pid;
192         int status;
193
194         argv[argc] = NULL;
195         pid = fork();
196         if (pid < 0)
197                 return pid;
198         if (!pid) {
199                 execvp("grep", (char **) argv);
200                 exit(255);
201         }
202         while (waitpid(pid, &status, 0) < 0) {
203                 if (errno == EINTR)
204                         continue;
205                 return -1;
206         }
207         if (WIFEXITED(status)) {
208                 if (!WEXITSTATUS(status))
209                         return 1;
210                 return 0;
211         }
212         return -1;
213 }
214
215 #define MAXARGS 1000
216 #define ARGBUF 4096
217 #define push_arg(a) do { \
218         if (nr < MAXARGS) argv[nr++] = (a); \
219         else die("maximum number of args exceeded"); \
220         } while (0)
221
222 /*
223  * If you send a singleton filename to grep, it does not give
224  * the name of the file.  GNU grep has "-H" but we would want
225  * that behaviour in a portable way.
226  *
227  * So we keep two pathnames in argv buffer unsent to grep in
228  * the main loop if we need to do more than one grep.
229  */
230 static int flush_grep(struct grep_opt *opt,
231                       int argc, int arg0, const char **argv, int *kept)
232 {
233         int status;
234         int count = argc - arg0;
235         const char *kept_0 = NULL;
236
237         if (count <= 2) {
238                 /*
239                  * Because we keep at least 2 paths in the call from
240                  * the main loop (i.e. kept != NULL), and MAXARGS is
241                  * far greater than 2, this usually is a call to
242                  * conclude the grep.  However, the user could attempt
243                  * to overflow the argv buffer by giving too many
244                  * options to leave very small number of real
245                  * arguments even for the call in the main loop.
246                  */
247                 if (kept)
248                         die("insanely many options to grep");
249
250                 /*
251                  * If we have two or more paths, we do not have to do
252                  * anything special, but we need to push /dev/null to
253                  * get "-H" behaviour of GNU grep portably but when we
254                  * are not doing "-l" nor "-L" nor "-c".
255                  */
256                 if (count == 1 &&
257                     !opt->name_only &&
258                     !opt->unmatch_name_only &&
259                     !opt->count) {
260                         argv[argc++] = "/dev/null";
261                         argv[argc] = NULL;
262                 }
263         }
264
265         else if (kept) {
266                 /*
267                  * Called because we found many paths and haven't finished
268                  * iterating over the cache yet.  We keep two paths
269                  * for the concluding call.  argv[argc-2] and argv[argc-1]
270                  * has the last two paths, so save the first one away,
271                  * replace it with NULL while sending the list to grep,
272                  * and recover them after we are done.
273                  */
274                 *kept = 2;
275                 kept_0 = argv[argc-2];
276                 argv[argc-2] = NULL;
277                 argc -= 2;
278         }
279
280         status = exec_grep(argc, argv);
281
282         if (kept_0) {
283                 /*
284                  * Then recover them.  Now the last arg is beyond the
285                  * terminating NULL which is at argc, and the second
286                  * from the last is what we saved away in kept_0
287                  */
288                 argv[arg0++] = kept_0;
289                 argv[arg0] = argv[argc+1];
290         }
291         return status;
292 }
293
294 static void grep_add_color(struct strbuf *sb, const char *escape_seq)
295 {
296         size_t orig_len = sb->len;
297
298         while (*escape_seq) {
299                 if (*escape_seq == 'm')
300                         strbuf_addch(sb, ';');
301                 else if (*escape_seq != '\033' && *escape_seq  != '[')
302                         strbuf_addch(sb, *escape_seq);
303                 escape_seq++;
304         }
305         if (sb->len > orig_len && sb->buf[sb->len - 1] == ';')
306                 strbuf_setlen(sb, sb->len - 1);
307 }
308
309 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
310 {
311         int i, nr, argc, hit, len, status;
312         const char *argv[MAXARGS+1];
313         char randarg[ARGBUF];
314         char *argptr = randarg;
315         struct grep_pat *p;
316
317         if (opt->extended || (opt->relative && opt->prefix_length))
318                 return -1;
319         len = nr = 0;
320         push_arg("grep");
321         if (opt->fixed)
322                 push_arg("-F");
323         if (opt->linenum)
324                 push_arg("-n");
325         if (!opt->pathname)
326                 push_arg("-h");
327         if (opt->regflags & REG_EXTENDED)
328                 push_arg("-E");
329         if (opt->regflags & REG_ICASE)
330                 push_arg("-i");
331         if (opt->binary == GREP_BINARY_NOMATCH)
332                 push_arg("-I");
333         if (opt->word_regexp)
334                 push_arg("-w");
335         if (opt->name_only)
336                 push_arg("-l");
337         if (opt->unmatch_name_only)
338                 push_arg("-L");
339         if (opt->null_following_name)
340                 /* in GNU grep git's "-z" translates to "-Z" */
341                 push_arg("-Z");
342         if (opt->count)
343                 push_arg("-c");
344         if (opt->post_context || opt->pre_context) {
345                 if (opt->post_context != opt->pre_context) {
346                         if (opt->pre_context) {
347                                 push_arg("-B");
348                                 len += snprintf(argptr, sizeof(randarg)-len,
349                                                 "%u", opt->pre_context) + 1;
350                                 if (sizeof(randarg) <= len)
351                                         die("maximum length of args exceeded");
352                                 push_arg(argptr);
353                                 argptr += len;
354                         }
355                         if (opt->post_context) {
356                                 push_arg("-A");
357                                 len += snprintf(argptr, sizeof(randarg)-len,
358                                                 "%u", opt->post_context) + 1;
359                                 if (sizeof(randarg) <= len)
360                                         die("maximum length of args exceeded");
361                                 push_arg(argptr);
362                                 argptr += len;
363                         }
364                 }
365                 else {
366                         push_arg("-C");
367                         len += snprintf(argptr, sizeof(randarg)-len,
368                                         "%u", opt->post_context) + 1;
369                         if (sizeof(randarg) <= len)
370                                 die("maximum length of args exceeded");
371                         push_arg(argptr);
372                         argptr += len;
373                 }
374         }
375         for (p = opt->pattern_list; p; p = p->next) {
376                 push_arg("-e");
377                 push_arg(p->pattern);
378         }
379         if (opt->color) {
380                 struct strbuf sb = STRBUF_INIT;
381
382                 grep_add_color(&sb, opt->color_match);
383                 setenv("GREP_COLOR", sb.buf, 1);
384
385                 strbuf_reset(&sb);
386                 strbuf_addstr(&sb, "mt=");
387                 grep_add_color(&sb, opt->color_match);
388                 strbuf_addstr(&sb, ":sl=:cx=:fn=:ln=:bn=:se=");
389                 setenv("GREP_COLORS", sb.buf, 1);
390
391                 strbuf_release(&sb);
392
393                 if (opt->color_external && strlen(opt->color_external) > 0)
394                         push_arg(opt->color_external);
395         }
396
397         hit = 0;
398         argc = nr;
399         for (i = 0; i < active_nr; i++) {
400                 struct cache_entry *ce = active_cache[i];
401                 char *name;
402                 int kept;
403                 if (!S_ISREG(ce->ce_mode))
404                         continue;
405                 if (!pathspec_matches(paths, ce->name))
406                         continue;
407                 name = ce->name;
408                 if (name[0] == '-') {
409                         int len = ce_namelen(ce);
410                         name = xmalloc(len + 3);
411                         memcpy(name, "./", 2);
412                         memcpy(name + 2, ce->name, len + 1);
413                 }
414                 argv[argc++] = name;
415                 if (MAXARGS <= argc) {
416                         status = flush_grep(opt, argc, nr, argv, &kept);
417                         if (0 < status)
418                                 hit = 1;
419                         argc = nr + kept;
420                 }
421                 if (ce_stage(ce)) {
422                         do {
423                                 i++;
424                         } while (i < active_nr &&
425                                  !strcmp(ce->name, active_cache[i]->name));
426                         i--; /* compensate for loop control */
427                 }
428         }
429         if (argc > nr) {
430                 status = flush_grep(opt, argc, nr, argv, NULL);
431                 if (0 < status)
432                         hit = 1;
433         }
434         return hit;
435 }
436 #endif
437
438 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
439 {
440         int hit = 0;
441         int nr;
442         read_cache();
443
444 #if !NO_EXTERNAL_GREP
445         /*
446          * Use the external "grep" command for the case where
447          * we grep through the checked-out files. It tends to
448          * be a lot more optimized
449          */
450         if (!cached && !builtin_grep) {
451                 hit = external_grep(opt, paths, cached);
452                 if (hit >= 0)
453                         return hit;
454         }
455 #endif
456
457         for (nr = 0; nr < active_nr; nr++) {
458                 struct cache_entry *ce = active_cache[nr];
459                 if (!S_ISREG(ce->ce_mode))
460                         continue;
461                 if (!pathspec_matches(paths, ce->name))
462                         continue;
463                 /*
464                  * If CE_VALID is on, we assume worktree file and its cache entry
465                  * are identical, even if worktree file has been modified, so use
466                  * cache version instead
467                  */
468                 if (cached || (ce->ce_flags & CE_VALID)) {
469                         if (ce_stage(ce))
470                                 continue;
471                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
472                 }
473                 else
474                         hit |= grep_file(opt, ce->name);
475                 if (ce_stage(ce)) {
476                         do {
477                                 nr++;
478                         } while (nr < active_nr &&
479                                  !strcmp(ce->name, active_cache[nr]->name));
480                         nr--; /* compensate for loop control */
481                 }
482         }
483         free_grep_patterns(opt);
484         return hit;
485 }
486
487 static int grep_tree(struct grep_opt *opt, const char **paths,
488                      struct tree_desc *tree,
489                      const char *tree_name, const char *base)
490 {
491         int len;
492         int hit = 0;
493         struct name_entry entry;
494         char *down;
495         int tn_len = strlen(tree_name);
496         struct strbuf pathbuf;
497
498         strbuf_init(&pathbuf, PATH_MAX + tn_len);
499
500         if (tn_len) {
501                 strbuf_add(&pathbuf, tree_name, tn_len);
502                 strbuf_addch(&pathbuf, ':');
503                 tn_len = pathbuf.len;
504         }
505         strbuf_addstr(&pathbuf, base);
506         len = pathbuf.len;
507
508         while (tree_entry(tree, &entry)) {
509                 int te_len = tree_entry_len(entry.path, entry.sha1);
510                 pathbuf.len = len;
511                 strbuf_add(&pathbuf, entry.path, te_len);
512
513                 if (S_ISDIR(entry.mode))
514                         /* Match "abc/" against pathspec to
515                          * decide if we want to descend into "abc"
516                          * directory.
517                          */
518                         strbuf_addch(&pathbuf, '/');
519
520                 down = pathbuf.buf + tn_len;
521                 if (!pathspec_matches(paths, down))
522                         ;
523                 else if (S_ISREG(entry.mode))
524                         hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
525                 else if (S_ISDIR(entry.mode)) {
526                         enum object_type type;
527                         struct tree_desc sub;
528                         void *data;
529                         unsigned long size;
530
531                         data = read_sha1_file(entry.sha1, &type, &size);
532                         if (!data)
533                                 die("unable to read tree (%s)",
534                                     sha1_to_hex(entry.sha1));
535                         init_tree_desc(&sub, data, size);
536                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
537                         free(data);
538                 }
539         }
540         strbuf_release(&pathbuf);
541         return hit;
542 }
543
544 static int grep_object(struct grep_opt *opt, const char **paths,
545                        struct object *obj, const char *name)
546 {
547         if (obj->type == OBJ_BLOB)
548                 return grep_sha1(opt, obj->sha1, name, 0);
549         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
550                 struct tree_desc tree;
551                 void *data;
552                 unsigned long size;
553                 int hit;
554                 data = read_object_with_reference(obj->sha1, tree_type,
555                                                   &size, NULL);
556                 if (!data)
557                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
558                 init_tree_desc(&tree, data, size);
559                 hit = grep_tree(opt, paths, &tree, name, "");
560                 free(data);
561                 return hit;
562         }
563         die("unable to grep from object of type %s", typename(obj->type));
564 }
565
566 static const char builtin_grep_usage[] =
567 "git grep <option>* [-e] <pattern> <rev>* [[--] <path>...]";
568
569 static const char emsg_invalid_context_len[] =
570 "%s: invalid context length argument";
571 static const char emsg_missing_context_len[] =
572 "missing context length argument";
573 static const char emsg_missing_argument[] =
574 "option requires an argument -%s";
575
576 int cmd_grep(int argc, const char **argv, const char *prefix)
577 {
578         int hit = 0;
579         int cached = 0;
580         int seen_dashdash = 0;
581         struct grep_opt opt;
582         struct object_array list = { 0, 0, NULL };
583         const char **paths = NULL;
584         int i;
585
586         memset(&opt, 0, sizeof(opt));
587         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
588         opt.relative = 1;
589         opt.pathname = 1;
590         opt.pattern_tail = &opt.pattern_list;
591         opt.regflags = REG_NEWLINE;
592
593         strcpy(opt.color_match, GIT_COLOR_RED GIT_COLOR_BOLD);
594         opt.color = -1;
595         git_config(grep_config, &opt);
596         if (opt.color == -1)
597                 opt.color = git_use_color_default;
598
599         /*
600          * If there is no -- then the paths must exist in the working
601          * tree.  If there is no explicit pattern specified with -e or
602          * -f, we take the first unrecognized non option to be the
603          * pattern, but then what follows it must be zero or more
604          * valid refs up to the -- (if exists), and then existing
605          * paths.  If there is an explicit pattern, then the first
606          * unrecognized non option is the beginning of the refs list
607          * that continues up to the -- (if exists), and then paths.
608          */
609
610         while (1 < argc) {
611                 const char *arg = argv[1];
612                 argc--; argv++;
613                 if (!strcmp("--cached", arg)) {
614                         cached = 1;
615                         continue;
616                 }
617                 if (!strcmp("--no-ext-grep", arg)) {
618                         builtin_grep = 1;
619                         continue;
620                 }
621                 if (!strcmp("-a", arg) ||
622                     !strcmp("--text", arg)) {
623                         opt.binary = GREP_BINARY_TEXT;
624                         continue;
625                 }
626                 if (!strcmp("-i", arg) ||
627                     !strcmp("--ignore-case", arg)) {
628                         opt.regflags |= REG_ICASE;
629                         continue;
630                 }
631                 if (!strcmp("-I", arg)) {
632                         opt.binary = GREP_BINARY_NOMATCH;
633                         continue;
634                 }
635                 if (!strcmp("-v", arg) ||
636                     !strcmp("--invert-match", arg)) {
637                         opt.invert = 1;
638                         continue;
639                 }
640                 if (!strcmp("-E", arg) ||
641                     !strcmp("--extended-regexp", arg)) {
642                         opt.regflags |= REG_EXTENDED;
643                         continue;
644                 }
645                 if (!strcmp("-F", arg) ||
646                     !strcmp("--fixed-strings", arg)) {
647                         opt.fixed = 1;
648                         continue;
649                 }
650                 if (!strcmp("-G", arg) ||
651                     !strcmp("--basic-regexp", arg)) {
652                         opt.regflags &= ~REG_EXTENDED;
653                         continue;
654                 }
655                 if (!strcmp("-n", arg)) {
656                         opt.linenum = 1;
657                         continue;
658                 }
659                 if (!strcmp("-h", arg)) {
660                         opt.pathname = 0;
661                         continue;
662                 }
663                 if (!strcmp("-H", arg)) {
664                         opt.pathname = 1;
665                         continue;
666                 }
667                 if (!strcmp("-l", arg) ||
668                     !strcmp("--name-only", arg) ||
669                     !strcmp("--files-with-matches", arg)) {
670                         opt.name_only = 1;
671                         continue;
672                 }
673                 if (!strcmp("-L", arg) ||
674                     !strcmp("--files-without-match", arg)) {
675                         opt.unmatch_name_only = 1;
676                         continue;
677                 }
678                 if (!strcmp("-z", arg) ||
679                     !strcmp("--null", arg)) {
680                         opt.null_following_name = 1;
681                         continue;
682                 }
683                 if (!strcmp("-c", arg) ||
684                     !strcmp("--count", arg)) {
685                         opt.count = 1;
686                         continue;
687                 }
688                 if (!strcmp("-w", arg) ||
689                     !strcmp("--word-regexp", arg)) {
690                         opt.word_regexp = 1;
691                         continue;
692                 }
693                 if (!prefixcmp(arg, "-A") ||
694                     !prefixcmp(arg, "-B") ||
695                     !prefixcmp(arg, "-C") ||
696                     (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
697                         unsigned num;
698                         const char *scan;
699                         switch (arg[1]) {
700                         case 'A': case 'B': case 'C':
701                                 if (!arg[2]) {
702                                         if (argc <= 1)
703                                                 die(emsg_missing_context_len);
704                                         scan = *++argv;
705                                         argc--;
706                                 }
707                                 else
708                                         scan = arg + 2;
709                                 break;
710                         default:
711                                 scan = arg + 1;
712                                 break;
713                         }
714                         if (strtoul_ui(scan, 10, &num))
715                                 die(emsg_invalid_context_len, scan);
716                         switch (arg[1]) {
717                         case 'A':
718                                 opt.post_context = num;
719                                 break;
720                         default:
721                         case 'C':
722                                 opt.post_context = num;
723                         case 'B':
724                                 opt.pre_context = num;
725                                 break;
726                         }
727                         continue;
728                 }
729                 if (!strcmp("-f", arg)) {
730                         FILE *patterns;
731                         int lno = 0;
732                         char buf[1024];
733                         if (argc <= 1)
734                                 die(emsg_missing_argument, arg);
735                         patterns = fopen(argv[1], "r");
736                         if (!patterns)
737                                 die("'%s': %s", argv[1], strerror(errno));
738                         while (fgets(buf, sizeof(buf), patterns)) {
739                                 int len = strlen(buf);
740                                 if (len && buf[len-1] == '\n')
741                                         buf[len-1] = 0;
742                                 /* ignore empty line like grep does */
743                                 if (!buf[0])
744                                         continue;
745                                 append_grep_pattern(&opt, xstrdup(buf),
746                                                     argv[1], ++lno,
747                                                     GREP_PATTERN);
748                         }
749                         fclose(patterns);
750                         argv++;
751                         argc--;
752                         continue;
753                 }
754                 if (!strcmp("--not", arg)) {
755                         append_grep_pattern(&opt, arg, "command line", 0,
756                                             GREP_NOT);
757                         continue;
758                 }
759                 if (!strcmp("--and", arg)) {
760                         append_grep_pattern(&opt, arg, "command line", 0,
761                                             GREP_AND);
762                         continue;
763                 }
764                 if (!strcmp("--or", arg))
765                         continue; /* no-op */
766                 if (!strcmp("(", arg)) {
767                         append_grep_pattern(&opt, arg, "command line", 0,
768                                             GREP_OPEN_PAREN);
769                         continue;
770                 }
771                 if (!strcmp(")", arg)) {
772                         append_grep_pattern(&opt, arg, "command line", 0,
773                                             GREP_CLOSE_PAREN);
774                         continue;
775                 }
776                 if (!strcmp("--all-match", arg)) {
777                         opt.all_match = 1;
778                         continue;
779                 }
780                 if (!strcmp("-e", arg)) {
781                         if (1 < argc) {
782                                 append_grep_pattern(&opt, argv[1],
783                                                     "-e option", 0,
784                                                     GREP_PATTERN);
785                                 argv++;
786                                 argc--;
787                                 continue;
788                         }
789                         die(emsg_missing_argument, arg);
790                 }
791                 if (!strcmp("--full-name", arg)) {
792                         opt.relative = 0;
793                         continue;
794                 }
795                 if (!strcmp("--color", arg)) {
796                         opt.color = 1;
797                         continue;
798                 }
799                 if (!strcmp("--no-color", arg)) {
800                         opt.color = 0;
801                         continue;
802                 }
803                 if (!strcmp("--", arg)) {
804                         /* later processing wants to have this at argv[1] */
805                         argv--;
806                         argc++;
807                         break;
808                 }
809                 if (*arg == '-')
810                         usage(builtin_grep_usage);
811
812                 /* First unrecognized non-option token */
813                 if (!opt.pattern_list) {
814                         append_grep_pattern(&opt, arg, "command line", 0,
815                                             GREP_PATTERN);
816                         break;
817                 }
818                 else {
819                         /* We are looking at the first path or rev;
820                          * it is found at argv[1] after leaving the
821                          * loop.
822                          */
823                         argc++; argv--;
824                         break;
825                 }
826         }
827
828         if (opt.color && !opt.color_external)
829                 builtin_grep = 1;
830         if (!opt.pattern_list)
831                 die("no pattern given.");
832         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
833                 die("cannot mix --fixed-strings and regexp");
834         compile_grep_patterns(&opt);
835
836         /* Check revs and then paths */
837         for (i = 1; i < argc; i++) {
838                 const char *arg = argv[i];
839                 unsigned char sha1[20];
840                 /* Is it a rev? */
841                 if (!get_sha1(arg, sha1)) {
842                         struct object *object = parse_object(sha1);
843                         if (!object)
844                                 die("bad object %s", arg);
845                         add_object_array(object, arg, &list);
846                         continue;
847                 }
848                 if (!strcmp(arg, "--")) {
849                         i++;
850                         seen_dashdash = 1;
851                 }
852                 break;
853         }
854
855         /* The rest are paths */
856         if (!seen_dashdash) {
857                 int j;
858                 for (j = i; j < argc; j++)
859                         verify_filename(prefix, argv[j]);
860         }
861
862         if (i < argc) {
863                 paths = get_pathspec(prefix, argv + i);
864                 if (opt.prefix_length && opt.relative) {
865                         /* Make sure we do not get outside of paths */
866                         for (i = 0; paths[i]; i++)
867                                 if (strncmp(prefix, paths[i], opt.prefix_length))
868                                         die("git grep: cannot generate relative filenames containing '..'");
869                 }
870         }
871         else if (prefix) {
872                 paths = xcalloc(2, sizeof(const char *));
873                 paths[0] = prefix;
874                 paths[1] = NULL;
875         }
876
877         if (!list.nr) {
878                 if (!cached)
879                         setup_work_tree();
880                 return !grep_cache(&opt, paths, cached);
881         }
882
883         if (cached)
884                 die("both --cached and trees are given.");
885
886         for (i = 0; i < list.nr; i++) {
887                 struct object *real_obj;
888                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
889                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
890                         hit = 1;
891         }
892         free_grep_patterns(&opt);
893         return !hit;
894 }