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