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