Merge early parts of branch 'np/pack'
[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         return hit;
329 }
330
331 static int grep_tree(struct grep_opt *opt, const char **paths,
332                      struct tree_desc *tree,
333                      const char *tree_name, const char *base)
334 {
335         int len;
336         int hit = 0;
337         struct name_entry entry;
338         char *down;
339         int tn_len = strlen(tree_name);
340         char *path_buf = xmalloc(PATH_MAX + tn_len + 100);
341
342         if (tn_len) {
343                 tn_len = sprintf(path_buf, "%s:", tree_name);
344                 down = path_buf + tn_len;
345                 strcat(down, base);
346         }
347         else {
348                 down = path_buf;
349                 strcpy(down, base);
350         }
351         len = strlen(path_buf);
352
353         while (tree_entry(tree, &entry)) {
354                 strcpy(path_buf + len, entry.path);
355
356                 if (S_ISDIR(entry.mode))
357                         /* Match "abc/" against pathspec to
358                          * decide if we want to descend into "abc"
359                          * directory.
360                          */
361                         strcpy(path_buf + len + entry.pathlen, "/");
362
363                 if (!pathspec_matches(paths, down))
364                         ;
365                 else if (S_ISREG(entry.mode))
366                         hit |= grep_sha1(opt, entry.sha1, path_buf, tn_len);
367                 else if (S_ISDIR(entry.mode)) {
368                         char type[20];
369                         struct tree_desc sub;
370                         void *data;
371                         data = read_sha1_file(entry.sha1, type, &sub.size);
372                         if (!data)
373                                 die("unable to read tree (%s)",
374                                     sha1_to_hex(entry.sha1));
375                         sub.buf = data;
376                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
377                         free(data);
378                 }
379         }
380         return hit;
381 }
382
383 static int grep_object(struct grep_opt *opt, const char **paths,
384                        struct object *obj, const char *name)
385 {
386         if (obj->type == OBJ_BLOB)
387                 return grep_sha1(opt, obj->sha1, name, 0);
388         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
389                 struct tree_desc tree;
390                 void *data;
391                 int hit;
392                 data = read_object_with_reference(obj->sha1, tree_type,
393                                                   &tree.size, NULL);
394                 if (!data)
395                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
396                 tree.buf = data;
397                 hit = grep_tree(opt, paths, &tree, name, "");
398                 free(data);
399                 return hit;
400         }
401         die("unable to grep from object of type %s", typename(obj->type));
402 }
403
404 static const char builtin_grep_usage[] =
405 "git-grep <option>* <rev>* [-e] <pattern> [<path>...]";
406
407 static const char emsg_invalid_context_len[] =
408 "%s: invalid context length argument";
409 static const char emsg_missing_context_len[] =
410 "missing context length argument";
411 static const char emsg_missing_argument[] =
412 "option requires an argument -%s";
413
414 int cmd_grep(int argc, const char **argv, const char *prefix)
415 {
416         int hit = 0;
417         int cached = 0;
418         int seen_dashdash = 0;
419         struct grep_opt opt;
420         struct object_array list = { 0, 0, NULL };
421         const char **paths = NULL;
422         int i;
423
424         memset(&opt, 0, sizeof(opt));
425         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
426         opt.relative = 1;
427         opt.pathname = 1;
428         opt.pattern_tail = &opt.pattern_list;
429         opt.regflags = REG_NEWLINE;
430
431         /*
432          * If there is no -- then the paths must exist in the working
433          * tree.  If there is no explicit pattern specified with -e or
434          * -f, we take the first unrecognized non option to be the
435          * pattern, but then what follows it must be zero or more
436          * valid refs up to the -- (if exists), and then existing
437          * paths.  If there is an explicit pattern, then the first
438          * unrecognized non option is the beginning of the refs list
439          * that continues up to the -- (if exists), and then paths.
440          */
441
442         while (1 < argc) {
443                 const char *arg = argv[1];
444                 argc--; argv++;
445                 if (!strcmp("--cached", arg)) {
446                         cached = 1;
447                         continue;
448                 }
449                 if (!strcmp("-a", arg) ||
450                     !strcmp("--text", arg)) {
451                         opt.binary = GREP_BINARY_TEXT;
452                         continue;
453                 }
454                 if (!strcmp("-i", arg) ||
455                     !strcmp("--ignore-case", arg)) {
456                         opt.regflags |= REG_ICASE;
457                         continue;
458                 }
459                 if (!strcmp("-I", arg)) {
460                         opt.binary = GREP_BINARY_NOMATCH;
461                         continue;
462                 }
463                 if (!strcmp("-v", arg) ||
464                     !strcmp("--invert-match", arg)) {
465                         opt.invert = 1;
466                         continue;
467                 }
468                 if (!strcmp("-E", arg) ||
469                     !strcmp("--extended-regexp", arg)) {
470                         opt.regflags |= REG_EXTENDED;
471                         continue;
472                 }
473                 if (!strcmp("-F", arg) ||
474                     !strcmp("--fixed-strings", arg)) {
475                         opt.fixed = 1;
476                         continue;
477                 }
478                 if (!strcmp("-G", arg) ||
479                     !strcmp("--basic-regexp", arg)) {
480                         opt.regflags &= ~REG_EXTENDED;
481                         continue;
482                 }
483                 if (!strcmp("-n", arg)) {
484                         opt.linenum = 1;
485                         continue;
486                 }
487                 if (!strcmp("-h", arg)) {
488                         opt.pathname = 0;
489                         continue;
490                 }
491                 if (!strcmp("-H", arg)) {
492                         opt.pathname = 1;
493                         continue;
494                 }
495                 if (!strcmp("-l", arg) ||
496                     !strcmp("--files-with-matches", arg)) {
497                         opt.name_only = 1;
498                         continue;
499                 }
500                 if (!strcmp("-L", arg) ||
501                     !strcmp("--files-without-match", arg)) {
502                         opt.unmatch_name_only = 1;
503                         continue;
504                 }
505                 if (!strcmp("-c", arg) ||
506                     !strcmp("--count", arg)) {
507                         opt.count = 1;
508                         continue;
509                 }
510                 if (!strcmp("-w", arg) ||
511                     !strcmp("--word-regexp", arg)) {
512                         opt.word_regexp = 1;
513                         continue;
514                 }
515                 if (!strncmp("-A", arg, 2) ||
516                     !strncmp("-B", arg, 2) ||
517                     !strncmp("-C", arg, 2) ||
518                     (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
519                         unsigned num;
520                         const char *scan;
521                         switch (arg[1]) {
522                         case 'A': case 'B': case 'C':
523                                 if (!arg[2]) {
524                                         if (argc <= 1)
525                                                 die(emsg_missing_context_len);
526                                         scan = *++argv;
527                                         argc--;
528                                 }
529                                 else
530                                         scan = arg + 2;
531                                 break;
532                         default:
533                                 scan = arg + 1;
534                                 break;
535                         }
536                         if (sscanf(scan, "%u", &num) != 1)
537                                 die(emsg_invalid_context_len, scan);
538                         switch (arg[1]) {
539                         case 'A':
540                                 opt.post_context = num;
541                                 break;
542                         default:
543                         case 'C':
544                                 opt.post_context = num;
545                         case 'B':
546                                 opt.pre_context = num;
547                                 break;
548                         }
549                         continue;
550                 }
551                 if (!strcmp("-f", arg)) {
552                         FILE *patterns;
553                         int lno = 0;
554                         char buf[1024];
555                         if (argc <= 1)
556                                 die(emsg_missing_argument, arg);
557                         patterns = fopen(argv[1], "r");
558                         if (!patterns)
559                                 die("'%s': %s", argv[1], strerror(errno));
560                         while (fgets(buf, sizeof(buf), patterns)) {
561                                 int len = strlen(buf);
562                                 if (buf[len-1] == '\n')
563                                         buf[len-1] = 0;
564                                 /* ignore empty line like grep does */
565                                 if (!buf[0])
566                                         continue;
567                                 append_grep_pattern(&opt, xstrdup(buf),
568                                                     argv[1], ++lno,
569                                                     GREP_PATTERN);
570                         }
571                         fclose(patterns);
572                         argv++;
573                         argc--;
574                         continue;
575                 }
576                 if (!strcmp("--not", arg)) {
577                         append_grep_pattern(&opt, arg, "command line", 0,
578                                             GREP_NOT);
579                         continue;
580                 }
581                 if (!strcmp("--and", arg)) {
582                         append_grep_pattern(&opt, arg, "command line", 0,
583                                             GREP_AND);
584                         continue;
585                 }
586                 if (!strcmp("--or", arg))
587                         continue; /* no-op */
588                 if (!strcmp("(", arg)) {
589                         append_grep_pattern(&opt, arg, "command line", 0,
590                                             GREP_OPEN_PAREN);
591                         continue;
592                 }
593                 if (!strcmp(")", arg)) {
594                         append_grep_pattern(&opt, arg, "command line", 0,
595                                             GREP_CLOSE_PAREN);
596                         continue;
597                 }
598                 if (!strcmp("-e", arg)) {
599                         if (1 < argc) {
600                                 append_grep_pattern(&opt, argv[1],
601                                                     "-e option", 0,
602                                                     GREP_PATTERN);
603                                 argv++;
604                                 argc--;
605                                 continue;
606                         }
607                         die(emsg_missing_argument, arg);
608                 }
609                 if (!strcmp("--full-name", arg)) {
610                         opt.relative = 0;
611                         continue;
612                 }
613                 if (!strcmp("--", arg)) {
614                         /* later processing wants to have this at argv[1] */
615                         argv--;
616                         argc++;
617                         break;
618                 }
619                 if (*arg == '-')
620                         usage(builtin_grep_usage);
621
622                 /* First unrecognized non-option token */
623                 if (!opt.pattern_list) {
624                         append_grep_pattern(&opt, arg, "command line", 0,
625                                             GREP_PATTERN);
626                         break;
627                 }
628                 else {
629                         /* We are looking at the first path or rev;
630                          * it is found at argv[1] after leaving the
631                          * loop.
632                          */
633                         argc++; argv--;
634                         break;
635                 }
636         }
637
638         if (!opt.pattern_list)
639                 die("no pattern given.");
640         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
641                 die("cannot mix --fixed-strings and regexp");
642         compile_grep_patterns(&opt);
643
644         /* Check revs and then paths */
645         for (i = 1; i < argc; i++) {
646                 const char *arg = argv[i];
647                 unsigned char sha1[20];
648                 /* Is it a rev? */
649                 if (!get_sha1(arg, sha1)) {
650                         struct object *object = parse_object(sha1);
651                         if (!object)
652                                 die("bad object %s", arg);
653                         add_object_array(object, arg, &list);
654                         continue;
655                 }
656                 if (!strcmp(arg, "--")) {
657                         i++;
658                         seen_dashdash = 1;
659                 }
660                 break;
661         }
662
663         /* The rest are paths */
664         if (!seen_dashdash) {
665                 int j;
666                 for (j = i; j < argc; j++)
667                         verify_filename(prefix, argv[j]);
668         }
669
670         if (i < argc) {
671                 paths = get_pathspec(prefix, argv + i);
672                 if (opt.prefix_length && opt.relative) {
673                         /* Make sure we do not get outside of paths */
674                         for (i = 0; paths[i]; i++)
675                                 if (strncmp(prefix, paths[i], opt.prefix_length))
676                                         die("git-grep: cannot generate relative filenames containing '..'");
677                 }
678         }
679         else if (prefix) {
680                 paths = xcalloc(2, sizeof(const char *));
681                 paths[0] = prefix;
682                 paths[1] = NULL;
683         }
684
685         if (!list.nr)
686                 return !grep_cache(&opt, paths, cached);
687
688         if (cached)
689                 die("both --cached and trees are given.");
690
691         for (i = 0; i < list.nr; i++) {
692                 struct object *real_obj;
693                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
694                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
695                         hit = 1;
696         }
697         return !hit;
698 }