Documentation/git-parse-remote.txt: we deal with config vars as well
[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         char type[20];
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         if (lstat(filename, &st) < 0) {
126         err_ret:
127                 if (errno != ENOENT)
128                         error("'%s': %s", filename, strerror(errno));
129                 return 0;
130         }
131         if (!st.st_size)
132                 return 0; /* empty file -- no grep hit */
133         if (!S_ISREG(st.st_mode))
134                 return 0;
135         i = open(filename, O_RDONLY);
136         if (i < 0)
137                 goto err_ret;
138         data = xmalloc(st.st_size + 1);
139         if (st.st_size != read_in_full(i, data, st.st_size)) {
140                 error("'%s': short read %s", filename, strerror(errno));
141                 close(i);
142                 free(data);
143                 return 0;
144         }
145         close(i);
146         if (opt->relative && opt->prefix_length)
147                 filename += opt->prefix_length;
148         i = grep_buffer(opt, filename, data, st.st_size);
149         free(data);
150         return i;
151 }
152
153 static int exec_grep(int argc, const char **argv)
154 {
155         pid_t pid;
156         int status;
157
158         argv[argc] = NULL;
159         pid = fork();
160         if (pid < 0)
161                 return pid;
162         if (!pid) {
163                 execvp("grep", (char **) argv);
164                 exit(255);
165         }
166         while (waitpid(pid, &status, 0) < 0) {
167                 if (errno == EINTR)
168                         continue;
169                 return -1;
170         }
171         if (WIFEXITED(status)) {
172                 if (!WEXITSTATUS(status))
173                         return 1;
174                 return 0;
175         }
176         return -1;
177 }
178
179 #define MAXARGS 1000
180 #define ARGBUF 4096
181 #define push_arg(a) do { \
182         if (nr < MAXARGS) argv[nr++] = (a); \
183         else die("maximum number of args exceeded"); \
184         } while (0)
185
186 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
187 {
188         int i, nr, argc, hit, len, status;
189         const char *argv[MAXARGS+1];
190         char randarg[ARGBUF];
191         char *argptr = randarg;
192         struct grep_pat *p;
193
194         if (opt->extended || (opt->relative && opt->prefix_length))
195                 return -1;
196         len = nr = 0;
197         push_arg("grep");
198         if (opt->fixed)
199                 push_arg("-F");
200         if (opt->linenum)
201                 push_arg("-n");
202         if (!opt->pathname)
203                 push_arg("-h");
204         if (opt->regflags & REG_EXTENDED)
205                 push_arg("-E");
206         if (opt->regflags & REG_ICASE)
207                 push_arg("-i");
208         if (opt->word_regexp)
209                 push_arg("-w");
210         if (opt->name_only)
211                 push_arg("-l");
212         if (opt->unmatch_name_only)
213                 push_arg("-L");
214         if (opt->count)
215                 push_arg("-c");
216         if (opt->post_context || opt->pre_context) {
217                 if (opt->post_context != opt->pre_context) {
218                         if (opt->pre_context) {
219                                 push_arg("-B");
220                                 len += snprintf(argptr, sizeof(randarg)-len,
221                                                 "%u", opt->pre_context);
222                                 if (sizeof(randarg) <= len)
223                                         die("maximum length of args exceeded");
224                                 push_arg(argptr);
225                                 argptr += len;
226                         }
227                         if (opt->post_context) {
228                                 push_arg("-A");
229                                 len += snprintf(argptr, sizeof(randarg)-len,
230                                                 "%u", opt->post_context);
231                                 if (sizeof(randarg) <= len)
232                                         die("maximum length of args exceeded");
233                                 push_arg(argptr);
234                                 argptr += len;
235                         }
236                 }
237                 else {
238                         push_arg("-C");
239                         len += snprintf(argptr, sizeof(randarg)-len,
240                                         "%u", opt->post_context);
241                         if (sizeof(randarg) <= len)
242                                 die("maximum length of args exceeded");
243                         push_arg(argptr);
244                         argptr += len;
245                 }
246         }
247         for (p = opt->pattern_list; p; p = p->next) {
248                 push_arg("-e");
249                 push_arg(p->pattern);
250         }
251
252         /*
253          * To make sure we get the header printed out when we want it,
254          * add /dev/null to the paths to grep.  This is unnecessary
255          * (and wrong) with "-l" or "-L", which always print out the
256          * name anyway.
257          *
258          * GNU grep has "-H", but this is portable.
259          */
260         if (!opt->name_only && !opt->unmatch_name_only)
261                 push_arg("/dev/null");
262
263         hit = 0;
264         argc = nr;
265         for (i = 0; i < active_nr; i++) {
266                 struct cache_entry *ce = active_cache[i];
267                 char *name;
268                 if (!S_ISREG(ntohl(ce->ce_mode)))
269                         continue;
270                 if (!pathspec_matches(paths, ce->name))
271                         continue;
272                 name = ce->name;
273                 if (name[0] == '-') {
274                         int len = ce_namelen(ce);
275                         name = xmalloc(len + 3);
276                         memcpy(name, "./", 2);
277                         memcpy(name + 2, ce->name, len + 1);
278                 }
279                 argv[argc++] = name;
280                 if (argc < MAXARGS && !ce_stage(ce))
281                         continue;
282                 status = exec_grep(argc, argv);
283                 if (0 < status)
284                         hit = 1;
285                 argc = nr;
286                 if (ce_stage(ce)) {
287                         do {
288                                 i++;
289                         } while (i < active_nr &&
290                                  !strcmp(ce->name, active_cache[i]->name));
291                         i--; /* compensate for loop control */
292                 }
293         }
294         if (argc > nr) {
295                 status = exec_grep(argc, argv);
296                 if (0 < status)
297                         hit = 1;
298         }
299         return hit;
300 }
301
302 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
303 {
304         int hit = 0;
305         int nr;
306         read_cache();
307
308 #ifdef __unix__
309         /*
310          * Use the external "grep" command for the case where
311          * we grep through the checked-out files. It tends to
312          * be a lot more optimized
313          */
314         if (!cached) {
315                 hit = external_grep(opt, paths, cached);
316                 if (hit >= 0)
317                         return hit;
318         }
319 #endif
320
321         for (nr = 0; nr < active_nr; nr++) {
322                 struct cache_entry *ce = active_cache[nr];
323                 if (!S_ISREG(ntohl(ce->ce_mode)))
324                         continue;
325                 if (!pathspec_matches(paths, ce->name))
326                         continue;
327                 if (cached) {
328                         if (ce_stage(ce))
329                                 continue;
330                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
331                 }
332                 else
333                         hit |= grep_file(opt, ce->name);
334                 if (ce_stage(ce)) {
335                         do {
336                                 nr++;
337                         } while (nr < active_nr &&
338                                  !strcmp(ce->name, active_cache[nr]->name));
339                         nr--; /* compensate for loop control */
340                 }
341         }
342         free_grep_patterns(opt);
343         return hit;
344 }
345
346 static int grep_tree(struct grep_opt *opt, const char **paths,
347                      struct tree_desc *tree,
348                      const char *tree_name, const char *base)
349 {
350         int len;
351         int hit = 0;
352         struct name_entry entry;
353         char *down;
354         int tn_len = strlen(tree_name);
355         char *path_buf = xmalloc(PATH_MAX + tn_len + 100);
356
357         if (tn_len) {
358                 tn_len = sprintf(path_buf, "%s:", tree_name);
359                 down = path_buf + tn_len;
360                 strcat(down, base);
361         }
362         else {
363                 down = path_buf;
364                 strcpy(down, base);
365         }
366         len = strlen(path_buf);
367
368         while (tree_entry(tree, &entry)) {
369                 strcpy(path_buf + len, entry.path);
370
371                 if (S_ISDIR(entry.mode))
372                         /* Match "abc/" against pathspec to
373                          * decide if we want to descend into "abc"
374                          * directory.
375                          */
376                         strcpy(path_buf + len + entry.pathlen, "/");
377
378                 if (!pathspec_matches(paths, down))
379                         ;
380                 else if (S_ISREG(entry.mode))
381                         hit |= grep_sha1(opt, entry.sha1, path_buf, tn_len);
382                 else if (S_ISDIR(entry.mode)) {
383                         char type[20];
384                         struct tree_desc sub;
385                         void *data;
386                         data = read_sha1_file(entry.sha1, type, &sub.size);
387                         if (!data)
388                                 die("unable to read tree (%s)",
389                                     sha1_to_hex(entry.sha1));
390                         sub.buf = data;
391                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
392                         free(data);
393                 }
394         }
395         return hit;
396 }
397
398 static int grep_object(struct grep_opt *opt, const char **paths,
399                        struct object *obj, const char *name)
400 {
401         if (obj->type == OBJ_BLOB)
402                 return grep_sha1(opt, obj->sha1, name, 0);
403         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
404                 struct tree_desc tree;
405                 void *data;
406                 int hit;
407                 data = read_object_with_reference(obj->sha1, tree_type,
408                                                   &tree.size, NULL);
409                 if (!data)
410                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
411                 tree.buf = data;
412                 hit = grep_tree(opt, paths, &tree, name, "");
413                 free(data);
414                 return hit;
415         }
416         die("unable to grep from object of type %s", typename(obj->type));
417 }
418
419 static const char builtin_grep_usage[] =
420 "git-grep <option>* <rev>* [-e] <pattern> [<path>...]";
421
422 static const char emsg_invalid_context_len[] =
423 "%s: invalid context length argument";
424 static const char emsg_missing_context_len[] =
425 "missing context length argument";
426 static const char emsg_missing_argument[] =
427 "option requires an argument -%s";
428
429 int cmd_grep(int argc, const char **argv, const char *prefix)
430 {
431         int hit = 0;
432         int cached = 0;
433         int seen_dashdash = 0;
434         struct grep_opt opt;
435         struct object_array list = { 0, 0, NULL };
436         const char **paths = NULL;
437         int i;
438
439         memset(&opt, 0, sizeof(opt));
440         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
441         opt.relative = 1;
442         opt.pathname = 1;
443         opt.pattern_tail = &opt.pattern_list;
444         opt.regflags = REG_NEWLINE;
445
446         /*
447          * If there is no -- then the paths must exist in the working
448          * tree.  If there is no explicit pattern specified with -e or
449          * -f, we take the first unrecognized non option to be the
450          * pattern, but then what follows it must be zero or more
451          * valid refs up to the -- (if exists), and then existing
452          * paths.  If there is an explicit pattern, then the first
453          * unrecognized non option is the beginning of the refs list
454          * that continues up to the -- (if exists), and then paths.
455          */
456
457         while (1 < argc) {
458                 const char *arg = argv[1];
459                 argc--; argv++;
460                 if (!strcmp("--cached", arg)) {
461                         cached = 1;
462                         continue;
463                 }
464                 if (!strcmp("-a", arg) ||
465                     !strcmp("--text", arg)) {
466                         opt.binary = GREP_BINARY_TEXT;
467                         continue;
468                 }
469                 if (!strcmp("-i", arg) ||
470                     !strcmp("--ignore-case", arg)) {
471                         opt.regflags |= REG_ICASE;
472                         continue;
473                 }
474                 if (!strcmp("-I", arg)) {
475                         opt.binary = GREP_BINARY_NOMATCH;
476                         continue;
477                 }
478                 if (!strcmp("-v", arg) ||
479                     !strcmp("--invert-match", arg)) {
480                         opt.invert = 1;
481                         continue;
482                 }
483                 if (!strcmp("-E", arg) ||
484                     !strcmp("--extended-regexp", arg)) {
485                         opt.regflags |= REG_EXTENDED;
486                         continue;
487                 }
488                 if (!strcmp("-F", arg) ||
489                     !strcmp("--fixed-strings", arg)) {
490                         opt.fixed = 1;
491                         continue;
492                 }
493                 if (!strcmp("-G", arg) ||
494                     !strcmp("--basic-regexp", arg)) {
495                         opt.regflags &= ~REG_EXTENDED;
496                         continue;
497                 }
498                 if (!strcmp("-n", arg)) {
499                         opt.linenum = 1;
500                         continue;
501                 }
502                 if (!strcmp("-h", arg)) {
503                         opt.pathname = 0;
504                         continue;
505                 }
506                 if (!strcmp("-H", arg)) {
507                         opt.pathname = 1;
508                         continue;
509                 }
510                 if (!strcmp("-l", arg) ||
511                     !strcmp("--files-with-matches", arg)) {
512                         opt.name_only = 1;
513                         continue;
514                 }
515                 if (!strcmp("-L", arg) ||
516                     !strcmp("--files-without-match", arg)) {
517                         opt.unmatch_name_only = 1;
518                         continue;
519                 }
520                 if (!strcmp("-c", arg) ||
521                     !strcmp("--count", arg)) {
522                         opt.count = 1;
523                         continue;
524                 }
525                 if (!strcmp("-w", arg) ||
526                     !strcmp("--word-regexp", arg)) {
527                         opt.word_regexp = 1;
528                         continue;
529                 }
530                 if (!strncmp("-A", arg, 2) ||
531                     !strncmp("-B", arg, 2) ||
532                     !strncmp("-C", arg, 2) ||
533                     (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
534                         unsigned num;
535                         const char *scan;
536                         switch (arg[1]) {
537                         case 'A': case 'B': case 'C':
538                                 if (!arg[2]) {
539                                         if (argc <= 1)
540                                                 die(emsg_missing_context_len);
541                                         scan = *++argv;
542                                         argc--;
543                                 }
544                                 else
545                                         scan = arg + 2;
546                                 break;
547                         default:
548                                 scan = arg + 1;
549                                 break;
550                         }
551                         if (sscanf(scan, "%u", &num) != 1)
552                                 die(emsg_invalid_context_len, scan);
553                         switch (arg[1]) {
554                         case 'A':
555                                 opt.post_context = num;
556                                 break;
557                         default:
558                         case 'C':
559                                 opt.post_context = num;
560                         case 'B':
561                                 opt.pre_context = num;
562                                 break;
563                         }
564                         continue;
565                 }
566                 if (!strcmp("-f", arg)) {
567                         FILE *patterns;
568                         int lno = 0;
569                         char buf[1024];
570                         if (argc <= 1)
571                                 die(emsg_missing_argument, arg);
572                         patterns = fopen(argv[1], "r");
573                         if (!patterns)
574                                 die("'%s': %s", argv[1], strerror(errno));
575                         while (fgets(buf, sizeof(buf), patterns)) {
576                                 int len = strlen(buf);
577                                 if (buf[len-1] == '\n')
578                                         buf[len-1] = 0;
579                                 /* ignore empty line like grep does */
580                                 if (!buf[0])
581                                         continue;
582                                 append_grep_pattern(&opt, xstrdup(buf),
583                                                     argv[1], ++lno,
584                                                     GREP_PATTERN);
585                         }
586                         fclose(patterns);
587                         argv++;
588                         argc--;
589                         continue;
590                 }
591                 if (!strcmp("--not", arg)) {
592                         append_grep_pattern(&opt, arg, "command line", 0,
593                                             GREP_NOT);
594                         continue;
595                 }
596                 if (!strcmp("--and", arg)) {
597                         append_grep_pattern(&opt, arg, "command line", 0,
598                                             GREP_AND);
599                         continue;
600                 }
601                 if (!strcmp("--or", arg))
602                         continue; /* no-op */
603                 if (!strcmp("(", arg)) {
604                         append_grep_pattern(&opt, arg, "command line", 0,
605                                             GREP_OPEN_PAREN);
606                         continue;
607                 }
608                 if (!strcmp(")", arg)) {
609                         append_grep_pattern(&opt, arg, "command line", 0,
610                                             GREP_CLOSE_PAREN);
611                         continue;
612                 }
613                 if (!strcmp("--all-match", arg)) {
614                         opt.all_match = 1;
615                         continue;
616                 }
617                 if (!strcmp("-e", arg)) {
618                         if (1 < argc) {
619                                 append_grep_pattern(&opt, argv[1],
620                                                     "-e option", 0,
621                                                     GREP_PATTERN);
622                                 argv++;
623                                 argc--;
624                                 continue;
625                         }
626                         die(emsg_missing_argument, arg);
627                 }
628                 if (!strcmp("--full-name", arg)) {
629                         opt.relative = 0;
630                         continue;
631                 }
632                 if (!strcmp("--", arg)) {
633                         /* later processing wants to have this at argv[1] */
634                         argv--;
635                         argc++;
636                         break;
637                 }
638                 if (*arg == '-')
639                         usage(builtin_grep_usage);
640
641                 /* First unrecognized non-option token */
642                 if (!opt.pattern_list) {
643                         append_grep_pattern(&opt, arg, "command line", 0,
644                                             GREP_PATTERN);
645                         break;
646                 }
647                 else {
648                         /* We are looking at the first path or rev;
649                          * it is found at argv[1] after leaving the
650                          * loop.
651                          */
652                         argc++; argv--;
653                         break;
654                 }
655         }
656
657         if (!opt.pattern_list)
658                 die("no pattern given.");
659         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
660                 die("cannot mix --fixed-strings and regexp");
661         compile_grep_patterns(&opt);
662
663         /* Check revs and then paths */
664         for (i = 1; i < argc; i++) {
665                 const char *arg = argv[i];
666                 unsigned char sha1[20];
667                 /* Is it a rev? */
668                 if (!get_sha1(arg, sha1)) {
669                         struct object *object = parse_object(sha1);
670                         if (!object)
671                                 die("bad object %s", arg);
672                         add_object_array(object, arg, &list);
673                         continue;
674                 }
675                 if (!strcmp(arg, "--")) {
676                         i++;
677                         seen_dashdash = 1;
678                 }
679                 break;
680         }
681
682         /* The rest are paths */
683         if (!seen_dashdash) {
684                 int j;
685                 for (j = i; j < argc; j++)
686                         verify_filename(prefix, argv[j]);
687         }
688
689         if (i < argc) {
690                 paths = get_pathspec(prefix, argv + i);
691                 if (opt.prefix_length && opt.relative) {
692                         /* Make sure we do not get outside of paths */
693                         for (i = 0; paths[i]; i++)
694                                 if (strncmp(prefix, paths[i], opt.prefix_length))
695                                         die("git-grep: cannot generate relative filenames containing '..'");
696                 }
697         }
698         else if (prefix) {
699                 paths = xcalloc(2, sizeof(const char *));
700                 paths[0] = prefix;
701                 paths[1] = NULL;
702         }
703
704         if (!list.nr)
705                 return !grep_cache(&opt, paths, cached);
706
707         if (cached)
708                 die("both --cached and trees are given.");
709
710         for (i = 0; i < list.nr; i++) {
711                 struct object *real_obj;
712                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
713                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
714                         hit = 1;
715         }
716         free_grep_patterns(&opt);
717         return !hit;
718 }