Merge branch 'jc/upload-corrupt' into next
[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 <regex.h>
14 #include <fnmatch.h>
15 #include <sys/wait.h>
16
17 /*
18  * git grep pathspecs are somewhat different from diff-tree pathspecs;
19  * pathname wildcards are allowed.
20  */
21 static int pathspec_matches(const char **paths, const char *name)
22 {
23         int namelen, i;
24         if (!paths || !*paths)
25                 return 1;
26         namelen = strlen(name);
27         for (i = 0; paths[i]; i++) {
28                 const char *match = paths[i];
29                 int matchlen = strlen(match);
30                 const char *cp, *meta;
31
32                 if (!matchlen ||
33                     ((matchlen <= namelen) &&
34                      !strncmp(name, match, matchlen) &&
35                      (match[matchlen-1] == '/' ||
36                       name[matchlen] == '\0' || name[matchlen] == '/')))
37                         return 1;
38                 if (!fnmatch(match, name, 0))
39                         return 1;
40                 if (name[namelen-1] != '/')
41                         continue;
42
43                 /* We are being asked if the directory ("name") is worth
44                  * descending into.
45                  *
46                  * Find the longest leading directory name that does
47                  * not have metacharacter in the pathspec; the name
48                  * we are looking at must overlap with that directory.
49                  */
50                 for (cp = match, meta = NULL; cp - match < matchlen; cp++) {
51                         char ch = *cp;
52                         if (ch == '*' || ch == '[' || ch == '?') {
53                                 meta = cp;
54                                 break;
55                         }
56                 }
57                 if (!meta)
58                         meta = cp; /* fully literal */
59
60                 if (namelen <= meta - match) {
61                         /* Looking at "Documentation/" and
62                          * the pattern says "Documentation/howto/", or
63                          * "Documentation/diff*.txt".  The name we
64                          * have should match prefix.
65                          */
66                         if (!memcmp(match, name, namelen))
67                                 return 1;
68                         continue;
69                 }
70
71                 if (meta - match < namelen) {
72                         /* Looking at "Documentation/howto/" and
73                          * the pattern says "Documentation/h*";
74                          * match up to "Do.../h"; this avoids descending
75                          * into "Documentation/technical/".
76                          */
77                         if (!memcmp(match, name, meta - match))
78                                 return 1;
79                         continue;
80                 }
81         }
82         return 0;
83 }
84
85 struct grep_pat {
86         struct grep_pat *next;
87         const char *origin;
88         int no;
89         const char *pattern;
90         regex_t regexp;
91 };
92
93 struct grep_opt {
94         struct grep_pat *pattern_list;
95         struct grep_pat **pattern_tail;
96         regex_t regexp;
97         unsigned linenum:1;
98         unsigned invert:1;
99         unsigned name_only:1;
100         unsigned unmatch_name_only:1;
101         unsigned count:1;
102         unsigned word_regexp:1;
103         unsigned fixed:1;
104 #define GREP_BINARY_DEFAULT     0
105 #define GREP_BINARY_NOMATCH     1
106 #define GREP_BINARY_TEXT        2
107         unsigned binary:2;
108         int regflags;
109         unsigned pre_context;
110         unsigned post_context;
111 };
112
113 static void add_pattern(struct grep_opt *opt, const char *pat,
114                         const char *origin, int no)
115 {
116         struct grep_pat *p = xcalloc(1, sizeof(*p));
117         p->pattern = pat;
118         p->origin = origin;
119         p->no = no;
120         *opt->pattern_tail = p;
121         opt->pattern_tail = &p->next;
122         p->next = NULL;
123 }
124
125 static void compile_patterns(struct grep_opt *opt)
126 {
127         struct grep_pat *p;
128         for (p = opt->pattern_list; p; p = p->next) {
129                 int err = regcomp(&p->regexp, p->pattern, opt->regflags);
130                 if (err) {
131                         char errbuf[1024];
132                         char where[1024];
133                         if (p->no)
134                                 sprintf(where, "In '%s' at %d, ",
135                                         p->origin, p->no);
136                         else if (p->origin)
137                                 sprintf(where, "%s, ", p->origin);
138                         else
139                                 where[0] = 0;
140                         regerror(err, &p->regexp, errbuf, 1024);
141                         regfree(&p->regexp);
142                         die("%s'%s': %s", where, p->pattern, errbuf);
143                 }
144         }
145 }
146
147 static char *end_of_line(char *cp, unsigned long *left)
148 {
149         unsigned long l = *left;
150         while (l && *cp != '\n') {
151                 l--;
152                 cp++;
153         }
154         *left = l;
155         return cp;
156 }
157
158 static int word_char(char ch)
159 {
160         return isalnum(ch) || ch == '_';
161 }
162
163 static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
164                       const char *name, unsigned lno, char sign)
165 {
166         printf("%s%c", name, sign);
167         if (opt->linenum)
168                 printf("%d%c", lno, sign);
169         printf("%.*s\n", (int)(eol-bol), bol);
170 }
171
172 /*
173  * NEEDSWORK: share code with diff.c
174  */
175 #define FIRST_FEW_BYTES 8000
176 static int buffer_is_binary(const char *ptr, unsigned long size)
177 {
178         if (FIRST_FEW_BYTES < size)
179                 size = FIRST_FEW_BYTES;
180         if (memchr(ptr, 0, size))
181                 return 1;
182         return 0;
183 }
184
185 static int fixmatch(const char *pattern, char *line, regmatch_t *match)
186 {
187         char *hit = strstr(line, pattern);
188         if (!hit) {
189                 match->rm_so = match->rm_eo = -1;
190                 return REG_NOMATCH;
191         }
192         else {
193                 match->rm_so = hit - line;
194                 match->rm_eo = match->rm_so + strlen(pattern);
195                 return 0;
196         }
197 }
198
199 static int grep_buffer(struct grep_opt *opt, const char *name,
200                        char *buf, unsigned long size)
201 {
202         char *bol = buf;
203         unsigned long left = size;
204         unsigned lno = 1;
205         struct pre_context_line {
206                 char *bol;
207                 char *eol;
208         } *prev = NULL, *pcl;
209         unsigned last_hit = 0;
210         unsigned last_shown = 0;
211         int binary_match_only = 0;
212         const char *hunk_mark = "";
213         unsigned count = 0;
214
215         if (buffer_is_binary(buf, size)) {
216                 switch (opt->binary) {
217                 case GREP_BINARY_DEFAULT:
218                         binary_match_only = 1;
219                         break;
220                 case GREP_BINARY_NOMATCH:
221                         return 0; /* Assume unmatch */
222                         break;
223                 default:
224                         break;
225                 }
226         }
227
228         if (opt->pre_context)
229                 prev = xcalloc(opt->pre_context, sizeof(*prev));
230         if (opt->pre_context || opt->post_context)
231                 hunk_mark = "--\n";
232
233         while (left) {
234                 regmatch_t pmatch[10];
235                 char *eol, ch;
236                 int hit = 0;
237                 struct grep_pat *p;
238
239                 eol = end_of_line(bol, &left);
240                 ch = *eol;
241                 *eol = 0;
242
243                 for (p = opt->pattern_list; p; p = p->next) {
244                         if (!opt->fixed) {
245                                 regex_t *exp = &p->regexp;
246                                 hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
247                                                pmatch, 0);
248                         }
249                         else {
250                                 hit = !fixmatch(p->pattern, bol, pmatch);
251                         }
252
253                         if (hit && opt->word_regexp) {
254                                 /* Match beginning must be either
255                                  * beginning of the line, or at word
256                                  * boundary (i.e. the last char must
257                                  * not be alnum or underscore).
258                                  */
259                                 if ((pmatch[0].rm_so < 0) ||
260                                     (eol - bol) <= pmatch[0].rm_so ||
261                                     (pmatch[0].rm_eo < 0) ||
262                                     (eol - bol) < pmatch[0].rm_eo)
263                                         die("regexp returned nonsense");
264                                 if (pmatch[0].rm_so != 0 &&
265                                     word_char(bol[pmatch[0].rm_so-1]))
266                                         hit = 0;
267                                 if (pmatch[0].rm_eo != (eol-bol) &&
268                                     word_char(bol[pmatch[0].rm_eo]))
269                                         hit = 0;
270                         }
271                         if (hit)
272                                 break;
273                 }
274                 /* "grep -v -e foo -e bla" should list lines
275                  * that do not have either, so inversion should
276                  * be done outside.
277                  */
278                 if (opt->invert)
279                         hit = !hit;
280                 if (opt->unmatch_name_only) {
281                         if (hit)
282                                 return 0;
283                         goto next_line;
284                 }
285                 if (hit) {
286                         count++;
287                         if (binary_match_only) {
288                                 printf("Binary file %s matches\n", name);
289                                 return 1;
290                         }
291                         if (opt->name_only) {
292                                 printf("%s\n", name);
293                                 return 1;
294                         }
295                         /* Hit at this line.  If we haven't shown the
296                          * pre-context lines, we would need to show them.
297                          * When asked to do "count", this still show
298                          * the context which is nonsense, but the user
299                          * deserves to get that ;-).
300                          */
301                         if (opt->pre_context) {
302                                 unsigned from;
303                                 if (opt->pre_context < lno)
304                                         from = lno - opt->pre_context;
305                                 else
306                                         from = 1;
307                                 if (from <= last_shown)
308                                         from = last_shown + 1;
309                                 if (last_shown && from != last_shown + 1)
310                                         printf(hunk_mark);
311                                 while (from < lno) {
312                                         pcl = &prev[lno-from-1];
313                                         show_line(opt, pcl->bol, pcl->eol,
314                                                   name, from, '-');
315                                         from++;
316                                 }
317                                 last_shown = lno-1;
318                         }
319                         if (last_shown && lno != last_shown + 1)
320                                 printf(hunk_mark);
321                         if (!opt->count)
322                                 show_line(opt, bol, eol, name, lno, ':');
323                         last_shown = last_hit = lno;
324                 }
325                 else if (last_hit &&
326                          lno <= last_hit + opt->post_context) {
327                         /* If the last hit is within the post context,
328                          * we need to show this line.
329                          */
330                         if (last_shown && lno != last_shown + 1)
331                                 printf(hunk_mark);
332                         show_line(opt, bol, eol, name, lno, '-');
333                         last_shown = lno;
334                 }
335                 if (opt->pre_context) {
336                         memmove(prev+1, prev,
337                                 (opt->pre_context-1) * sizeof(*prev));
338                         prev->bol = bol;
339                         prev->eol = eol;
340                 }
341
342         next_line:
343                 *eol = ch;
344                 bol = eol + 1;
345                 if (!left)
346                         break;
347                 left--;
348                 lno++;
349         }
350
351         if (opt->unmatch_name_only) {
352                 /* We did not see any hit, so we want to show this */
353                 printf("%s\n", name);
354                 return 1;
355         }
356
357         /* NEEDSWORK:
358          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
359          * which feels mostly useless but sometimes useful.  Maybe
360          * make it another option?  For now suppress them.
361          */
362         if (opt->count && count)
363                 printf("%s:%u\n", name, count);
364         return !!last_hit;
365 }
366
367 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name)
368 {
369         unsigned long size;
370         char *data;
371         char type[20];
372         int hit;
373         data = read_sha1_file(sha1, type, &size);
374         if (!data) {
375                 error("'%s': unable to read %s", name, sha1_to_hex(sha1));
376                 return 0;
377         }
378         hit = grep_buffer(opt, name, data, size);
379         free(data);
380         return hit;
381 }
382
383 static int grep_file(struct grep_opt *opt, const char *filename)
384 {
385         struct stat st;
386         int i;
387         char *data;
388         if (lstat(filename, &st) < 0) {
389         err_ret:
390                 if (errno != ENOENT)
391                         error("'%s': %s", filename, strerror(errno));
392                 return 0;
393         }
394         if (!st.st_size)
395                 return 0; /* empty file -- no grep hit */
396         if (!S_ISREG(st.st_mode))
397                 return 0;
398         i = open(filename, O_RDONLY);
399         if (i < 0)
400                 goto err_ret;
401         data = xmalloc(st.st_size + 1);
402         if (st.st_size != xread(i, data, st.st_size)) {
403                 error("'%s': short read %s", filename, strerror(errno));
404                 close(i);
405                 free(data);
406                 return 0;
407         }
408         close(i);
409         i = grep_buffer(opt, filename, data, st.st_size);
410         free(data);
411         return i;
412 }
413
414 static int exec_grep(int argc, const char **argv)
415 {
416         pid_t pid;
417         int status;
418
419         argv[argc] = NULL;
420         pid = fork();
421         if (pid < 0)
422                 return pid;
423         if (!pid) {
424                 execvp("grep", (char **) argv);
425                 exit(255);
426         }
427         while (waitpid(pid, &status, 0) < 0) {
428                 if (errno == EINTR)
429                         continue;
430                 return -1;
431         }
432         if (WIFEXITED(status)) {
433                 if (!WEXITSTATUS(status))
434                         return 1;
435                 return 0;
436         }
437         return -1;
438 }
439
440 #define MAXARGS 1000
441 #define ARGBUF 4096
442 #define push_arg(a) do { \
443         if (nr < MAXARGS) argv[nr++] = (a); \
444         else die("maximum number of args exceeded"); \
445         } while (0)
446
447 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
448 {
449         int i, nr, argc, hit, len;
450         const char *argv[MAXARGS+1];
451         char randarg[ARGBUF];
452         char *argptr = randarg;
453         struct grep_pat *p;
454
455         len = nr = 0;
456         push_arg("grep");
457         if (opt->fixed)
458                 push_arg("-F");
459         if (opt->linenum)
460                 push_arg("-n");
461         if (opt->regflags & REG_EXTENDED)
462                 push_arg("-E");
463         if (opt->regflags & REG_ICASE)
464                 push_arg("-i");
465         if (opt->word_regexp)
466                 push_arg("-w");
467         if (opt->name_only)
468                 push_arg("-l");
469         if (opt->unmatch_name_only)
470                 push_arg("-L");
471         if (opt->count)
472                 push_arg("-c");
473         if (opt->post_context || opt->pre_context) {
474                 if (opt->post_context != opt->pre_context) {
475                         if (opt->pre_context) {
476                                 push_arg("-B");
477                                 len += snprintf(argptr, sizeof(randarg)-len,
478                                                 "%u", opt->pre_context);
479                                 if (sizeof(randarg) <= len)
480                                         die("maximum length of args exceeded");
481                                 push_arg(argptr);
482                                 argptr += len;
483                         }
484                         if (opt->post_context) {
485                                 push_arg("-A");
486                                 len += snprintf(argptr, sizeof(randarg)-len,
487                                                 "%u", opt->post_context);
488                                 if (sizeof(randarg) <= len)
489                                         die("maximum length of args exceeded");
490                                 push_arg(argptr);
491                                 argptr += len;
492                         }
493                 }
494                 else {
495                         push_arg("-C");
496                         len += snprintf(argptr, sizeof(randarg)-len,
497                                         "%u", opt->post_context);
498                         if (sizeof(randarg) <= len)
499                                 die("maximum length of args exceeded");
500                         push_arg(argptr);
501                         argptr += len;
502                 }
503         }
504         for (p = opt->pattern_list; p; p = p->next) {
505                 push_arg("-e");
506                 push_arg(p->pattern);
507         }
508
509         /*
510          * To make sure we get the header printed out when we want it,
511          * add /dev/null to the paths to grep.  This is unnecessary
512          * (and wrong) with "-l" or "-L", which always print out the
513          * name anyway.
514          *
515          * GNU grep has "-H", but this is portable.
516          */
517         if (!opt->name_only && !opt->unmatch_name_only)
518                 push_arg("/dev/null");
519
520         hit = 0;
521         argc = nr;
522         for (i = 0; i < active_nr; i++) {
523                 struct cache_entry *ce = active_cache[i];
524                 char *name;
525                 if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
526                         continue;
527                 if (!pathspec_matches(paths, ce->name))
528                         continue;
529                 name = ce->name;
530                 if (name[0] == '-') {
531                         int len = ce_namelen(ce);
532                         name = xmalloc(len + 3);
533                         memcpy(name, "./", 2);
534                         memcpy(name + 2, ce->name, len + 1);
535                 }
536                 argv[argc++] = name;
537                 if (argc < MAXARGS)
538                         continue;
539                 hit += exec_grep(argc, argv);
540                 argc = nr;
541         }
542         if (argc > nr)
543                 hit += exec_grep(argc, argv);
544         return 0;
545 }
546
547 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
548 {
549         int hit = 0;
550         int nr;
551         read_cache();
552
553 #ifdef __unix__
554         /*
555          * Use the external "grep" command for the case where
556          * we grep through the checked-out files. It tends to
557          * be a lot more optimized
558          */
559         if (!cached) {
560                 hit = external_grep(opt, paths, cached);
561                 if (hit >= 0)
562                         return hit;
563         }
564 #endif
565
566         for (nr = 0; nr < active_nr; nr++) {
567                 struct cache_entry *ce = active_cache[nr];
568                 if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
569                         continue;
570                 if (!pathspec_matches(paths, ce->name))
571                         continue;
572                 if (cached)
573                         hit |= grep_sha1(opt, ce->sha1, ce->name);
574                 else
575                         hit |= grep_file(opt, ce->name);
576         }
577         return hit;
578 }
579
580 static int grep_tree(struct grep_opt *opt, const char **paths,
581                      struct tree_desc *tree,
582                      const char *tree_name, const char *base)
583 {
584         int len;
585         int hit = 0;
586         struct name_entry entry;
587         char *down;
588         char *path_buf = xmalloc(PATH_MAX + strlen(tree_name) + 100);
589
590         if (tree_name[0]) {
591                 int offset = sprintf(path_buf, "%s:", tree_name);
592                 down = path_buf + offset;
593                 strcat(down, base);
594         }
595         else {
596                 down = path_buf;
597                 strcpy(down, base);
598         }
599         len = strlen(path_buf);
600
601         while (tree_entry(tree, &entry)) {
602                 strcpy(path_buf + len, entry.path);
603
604                 if (S_ISDIR(entry.mode))
605                         /* Match "abc/" against pathspec to
606                          * decide if we want to descend into "abc"
607                          * directory.
608                          */
609                         strcpy(path_buf + len + entry.pathlen, "/");
610
611                 if (!pathspec_matches(paths, down))
612                         ;
613                 else if (S_ISREG(entry.mode))
614                         hit |= grep_sha1(opt, entry.sha1, path_buf);
615                 else if (S_ISDIR(entry.mode)) {
616                         char type[20];
617                         struct tree_desc sub;
618                         void *data;
619                         data = read_sha1_file(entry.sha1, type, &sub.size);
620                         if (!data)
621                                 die("unable to read tree (%s)",
622                                     sha1_to_hex(entry.sha1));
623                         sub.buf = data;
624                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
625                         free(data);
626                 }
627         }
628         return hit;
629 }
630
631 static int grep_object(struct grep_opt *opt, const char **paths,
632                        struct object *obj, const char *name)
633 {
634         if (obj->type == TYPE_BLOB)
635                 return grep_sha1(opt, obj->sha1, name);
636         if (obj->type == TYPE_COMMIT || obj->type == TYPE_TREE) {
637                 struct tree_desc tree;
638                 void *data;
639                 int hit;
640                 data = read_object_with_reference(obj->sha1, tree_type,
641                                                   &tree.size, NULL);
642                 if (!data)
643                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
644                 tree.buf = data;
645                 hit = grep_tree(opt, paths, &tree, name, "");
646                 free(data);
647                 return hit;
648         }
649         die("unable to grep from object of type %s", typename(obj->type));
650 }
651
652 static const char builtin_grep_usage[] =
653 "git-grep <option>* <rev>* [-e] <pattern> [<path>...]";
654
655 int cmd_grep(int argc, const char **argv, char **envp)
656 {
657         int hit = 0;
658         int cached = 0;
659         int seen_dashdash = 0;
660         struct grep_opt opt;
661         struct object_array list = { 0, 0, NULL };
662         const char *prefix = setup_git_directory();
663         const char **paths = NULL;
664         int i;
665
666         memset(&opt, 0, sizeof(opt));
667         opt.pattern_tail = &opt.pattern_list;
668         opt.regflags = REG_NEWLINE;
669
670         /*
671          * If there is no -- then the paths must exist in the working
672          * tree.  If there is no explicit pattern specified with -e or
673          * -f, we take the first unrecognized non option to be the
674          * pattern, but then what follows it must be zero or more
675          * valid refs up to the -- (if exists), and then existing
676          * paths.  If there is an explicit pattern, then the first
677          * unrecocnized non option is the beginning of the refs list
678          * that continues up to the -- (if exists), and then paths.
679          */
680
681         while (1 < argc) {
682                 const char *arg = argv[1];
683                 argc--; argv++;
684                 if (!strcmp("--cached", arg)) {
685                         cached = 1;
686                         continue;
687                 }
688                 if (!strcmp("-a", arg) ||
689                     !strcmp("--text", arg)) {
690                         opt.binary = GREP_BINARY_TEXT;
691                         continue;
692                 }
693                 if (!strcmp("-i", arg) ||
694                     !strcmp("--ignore-case", arg)) {
695                         opt.regflags |= REG_ICASE;
696                         continue;
697                 }
698                 if (!strcmp("-I", arg)) {
699                         opt.binary = GREP_BINARY_NOMATCH;
700                         continue;
701                 }
702                 if (!strcmp("-v", arg) ||
703                     !strcmp("--invert-match", arg)) {
704                         opt.invert = 1;
705                         continue;
706                 }
707                 if (!strcmp("-E", arg) ||
708                     !strcmp("--extended-regexp", arg)) {
709                         opt.regflags |= REG_EXTENDED;
710                         continue;
711                 }
712                 if (!strcmp("-F", arg) ||
713                     !strcmp("--fixed-strings", arg)) {
714                         opt.fixed = 1;
715                         continue;
716                 }
717                 if (!strcmp("-G", arg) ||
718                     !strcmp("--basic-regexp", arg)) {
719                         opt.regflags &= ~REG_EXTENDED;
720                         continue;
721                 }
722                 if (!strcmp("-n", arg)) {
723                         opt.linenum = 1;
724                         continue;
725                 }
726                 if (!strcmp("-H", arg)) {
727                         /* We always show the pathname, so this
728                          * is a noop.
729                          */
730                         continue;
731                 }
732                 if (!strcmp("-l", arg) ||
733                     !strcmp("--files-with-matches", arg)) {
734                         opt.name_only = 1;
735                         continue;
736                 }
737                 if (!strcmp("-L", arg) ||
738                     !strcmp("--files-without-match", arg)) {
739                         opt.unmatch_name_only = 1;
740                         continue;
741                 }
742                 if (!strcmp("-c", arg) ||
743                     !strcmp("--count", arg)) {
744                         opt.count = 1;
745                         continue;
746                 }
747                 if (!strcmp("-w", arg) ||
748                     !strcmp("--word-regexp", arg)) {
749                         opt.word_regexp = 1;
750                         continue;
751                 }
752                 if (!strncmp("-A", arg, 2) ||
753                     !strncmp("-B", arg, 2) ||
754                     !strncmp("-C", arg, 2) ||
755                     (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
756                         unsigned num;
757                         const char *scan;
758                         switch (arg[1]) {
759                         case 'A': case 'B': case 'C':
760                                 if (!arg[2]) {
761                                         if (argc <= 1)
762                                                 usage(builtin_grep_usage);
763                                         scan = *++argv;
764                                         argc--;
765                                 }
766                                 else
767                                         scan = arg + 2;
768                                 break;
769                         default:
770                                 scan = arg + 1;
771                                 break;
772                         }
773                         if (sscanf(scan, "%u", &num) != 1)
774                                 usage(builtin_grep_usage);
775                         switch (arg[1]) {
776                         case 'A':
777                                 opt.post_context = num;
778                                 break;
779                         default:
780                         case 'C':
781                                 opt.post_context = num;
782                         case 'B':
783                                 opt.pre_context = num;
784                                 break;
785                         }
786                         continue;
787                 }
788                 if (!strcmp("-f", arg)) {
789                         FILE *patterns;
790                         int lno = 0;
791                         char buf[1024];
792                         if (argc <= 1)
793                                 usage(builtin_grep_usage);
794                         patterns = fopen(argv[1], "r");
795                         if (!patterns)
796                                 die("'%s': %s", argv[1], strerror(errno));
797                         while (fgets(buf, sizeof(buf), patterns)) {
798                                 int len = strlen(buf);
799                                 if (buf[len-1] == '\n')
800                                         buf[len-1] = 0;
801                                 /* ignore empty line like grep does */
802                                 if (!buf[0])
803                                         continue;
804                                 add_pattern(&opt, strdup(buf), argv[1], ++lno);
805                         }
806                         fclose(patterns);
807                         argv++;
808                         argc--;
809                         continue;
810                 }
811                 if (!strcmp("-e", arg)) {
812                         if (1 < argc) {
813                                 add_pattern(&opt, argv[1], "-e option", 0);
814                                 argv++;
815                                 argc--;
816                                 continue;
817                         }
818                         usage(builtin_grep_usage);
819                 }
820                 if (!strcmp("--", arg))
821                         break;
822                 if (*arg == '-')
823                         usage(builtin_grep_usage);
824
825                 /* First unrecognized non-option token */
826                 if (!opt.pattern_list) {
827                         add_pattern(&opt, arg, "command line", 0);
828                         break;
829                 }
830                 else {
831                         /* We are looking at the first path or rev;
832                          * it is found at argv[1] after leaving the
833                          * loop.
834                          */
835                         argc++; argv--;
836                         break;
837                 }
838         }
839
840         if (!opt.pattern_list)
841                 die("no pattern given.");
842         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
843                 die("cannot mix --fixed-strings and regexp");
844         if (!opt.fixed)
845                 compile_patterns(&opt);
846
847         /* Check revs and then paths */
848         for (i = 1; i < argc; i++) {
849                 const char *arg = argv[i];
850                 unsigned char sha1[20];
851                 /* Is it a rev? */
852                 if (!get_sha1(arg, sha1)) {
853                         struct object *object = parse_object(sha1);
854                         if (!object)
855                                 die("bad object %s", arg);
856                         add_object_array(object, arg, &list);
857                         continue;
858                 }
859                 if (!strcmp(arg, "--")) {
860                         i++;
861                         seen_dashdash = 1;
862                 }
863                 break;
864         }
865
866         /* The rest are paths */
867         if (!seen_dashdash) {
868                 int j;
869                 for (j = i; j < argc; j++)
870                         verify_filename(prefix, argv[j]);
871         }
872
873         if (i < argc)
874                 paths = get_pathspec(prefix, argv + i);
875         else if (prefix) {
876                 paths = xcalloc(2, sizeof(const char *));
877                 paths[0] = prefix;
878                 paths[1] = NULL;
879         }
880
881         if (!list.nr)
882                 return !grep_cache(&opt, paths, cached);
883
884         if (cached)
885                 die("both --cached and trees are given.");
886
887         for (i = 0; i < list.nr; i++) {
888                 struct object *real_obj;
889                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
890                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
891                         hit = 1;
892         }
893         return !hit;
894 }