Merge branch 'jc/format-patch'
[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 enum grep_pat_token {
86         GREP_PATTERN,
87         GREP_AND,
88         GREP_OPEN_PAREN,
89         GREP_CLOSE_PAREN,
90         GREP_NOT,
91         GREP_OR,
92 };
93
94 struct grep_pat {
95         struct grep_pat *next;
96         const char *origin;
97         int no;
98         enum grep_pat_token token;
99         const char *pattern;
100         regex_t regexp;
101 };
102
103 enum grep_expr_node {
104         GREP_NODE_ATOM,
105         GREP_NODE_NOT,
106         GREP_NODE_AND,
107         GREP_NODE_OR,
108 };
109
110 struct grep_expr {
111         enum grep_expr_node node;
112         union {
113                 struct grep_pat *atom;
114                 struct grep_expr *unary;
115                 struct {
116                         struct grep_expr *left;
117                         struct grep_expr *right;
118                 } binary;
119         } u;
120 };
121
122 struct grep_opt {
123         struct grep_pat *pattern_list;
124         struct grep_pat **pattern_tail;
125         struct grep_expr *pattern_expression;
126         int prefix_length;
127         regex_t regexp;
128         unsigned linenum:1;
129         unsigned invert:1;
130         unsigned name_only:1;
131         unsigned unmatch_name_only:1;
132         unsigned count:1;
133         unsigned word_regexp:1;
134         unsigned fixed:1;
135 #define GREP_BINARY_DEFAULT     0
136 #define GREP_BINARY_NOMATCH     1
137 #define GREP_BINARY_TEXT        2
138         unsigned binary:2;
139         unsigned extended:1;
140         unsigned relative:1;
141         int regflags;
142         unsigned pre_context;
143         unsigned post_context;
144 };
145
146 static void add_pattern(struct grep_opt *opt, const char *pat,
147                         const char *origin, int no, enum grep_pat_token t)
148 {
149         struct grep_pat *p = xcalloc(1, sizeof(*p));
150         p->pattern = pat;
151         p->origin = origin;
152         p->no = no;
153         p->token = t;
154         *opt->pattern_tail = p;
155         opt->pattern_tail = &p->next;
156         p->next = NULL;
157 }
158
159 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
160 {
161         int err = regcomp(&p->regexp, p->pattern, opt->regflags);
162         if (err) {
163                 char errbuf[1024];
164                 char where[1024];
165                 if (p->no)
166                         sprintf(where, "In '%s' at %d, ",
167                                 p->origin, p->no);
168                 else if (p->origin)
169                         sprintf(where, "%s, ", p->origin);
170                 else
171                         where[0] = 0;
172                 regerror(err, &p->regexp, errbuf, 1024);
173                 regfree(&p->regexp);
174                 die("%s'%s': %s", where, p->pattern, errbuf);
175         }
176 }
177
178 static struct grep_expr *compile_pattern_expr(struct grep_pat **);
179 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
180 {
181         struct grep_pat *p;
182         struct grep_expr *x;
183
184         p = *list;
185         switch (p->token) {
186         case GREP_PATTERN: /* atom */
187                 x = xcalloc(1, sizeof (struct grep_expr));
188                 x->node = GREP_NODE_ATOM;
189                 x->u.atom = p;
190                 *list = p->next;
191                 return x;
192         case GREP_OPEN_PAREN:
193                 *list = p->next;
194                 x = compile_pattern_expr(list);
195                 if (!x)
196                         return NULL;
197                 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
198                         die("unmatched parenthesis");
199                 *list = (*list)->next;
200                 return x;
201         default:
202                 return NULL;
203         }
204 }
205
206 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
207 {
208         struct grep_pat *p;
209         struct grep_expr *x;
210
211         p = *list;
212         switch (p->token) {
213         case GREP_NOT:
214                 if (!p->next)
215                         die("--not not followed by pattern expression");
216                 *list = p->next;
217                 x = xcalloc(1, sizeof (struct grep_expr));
218                 x->node = GREP_NODE_NOT;
219                 x->u.unary = compile_pattern_not(list);
220                 if (!x->u.unary)
221                         die("--not followed by non pattern expression");
222                 return x;
223         default:
224                 return compile_pattern_atom(list);
225         }
226 }
227
228 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
229 {
230         struct grep_pat *p;
231         struct grep_expr *x, *y, *z;
232
233         x = compile_pattern_not(list);
234         p = *list;
235         if (p && p->token == GREP_AND) {
236                 if (!p->next)
237                         die("--and not followed by pattern expression");
238                 *list = p->next;
239                 y = compile_pattern_and(list);
240                 if (!y)
241                         die("--and not followed by pattern expression");
242                 z = xcalloc(1, sizeof (struct grep_expr));
243                 z->node = GREP_NODE_AND;
244                 z->u.binary.left = x;
245                 z->u.binary.right = y;
246                 return z;
247         }
248         return x;
249 }
250
251 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
252 {
253         struct grep_pat *p;
254         struct grep_expr *x, *y, *z;
255
256         x = compile_pattern_and(list);
257         p = *list;
258         if (x && p && p->token != GREP_CLOSE_PAREN) {
259                 y = compile_pattern_or(list);
260                 if (!y)
261                         die("not a pattern expression %s", p->pattern);
262                 z = xcalloc(1, sizeof (struct grep_expr));
263                 z->node = GREP_NODE_OR;
264                 z->u.binary.left = x;
265                 z->u.binary.right = y;
266                 return z;
267         }
268         return x;
269 }
270
271 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
272 {
273         return compile_pattern_or(list);
274 }
275
276 static void compile_patterns(struct grep_opt *opt)
277 {
278         struct grep_pat *p;
279
280         /* First compile regexps */
281         for (p = opt->pattern_list; p; p = p->next) {
282                 if (p->token == GREP_PATTERN)
283                         compile_regexp(p, opt);
284                 else
285                         opt->extended = 1;
286         }
287
288         if (!opt->extended)
289                 return;
290
291         /* Then bundle them up in an expression.
292          * A classic recursive descent parser would do.
293          */
294         p = opt->pattern_list;
295         opt->pattern_expression = compile_pattern_expr(&p);
296 #if DEBUG
297         dump_pattern_exp(opt->pattern_expression, 0);
298 #endif
299         if (p)
300                 die("incomplete pattern expression: %s", p->pattern);
301 }
302
303 static char *end_of_line(char *cp, unsigned long *left)
304 {
305         unsigned long l = *left;
306         while (l && *cp != '\n') {
307                 l--;
308                 cp++;
309         }
310         *left = l;
311         return cp;
312 }
313
314 static int word_char(char ch)
315 {
316         return isalnum(ch) || ch == '_';
317 }
318
319 static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
320                       const char *name, unsigned lno, char sign)
321 {
322         printf("%s%c", name, sign);
323         if (opt->linenum)
324                 printf("%d%c", lno, sign);
325         printf("%.*s\n", (int)(eol-bol), bol);
326 }
327
328 /*
329  * NEEDSWORK: share code with diff.c
330  */
331 #define FIRST_FEW_BYTES 8000
332 static int buffer_is_binary(const char *ptr, unsigned long size)
333 {
334         if (FIRST_FEW_BYTES < size)
335                 size = FIRST_FEW_BYTES;
336         return !!memchr(ptr, 0, size);
337 }
338
339 static int fixmatch(const char *pattern, char *line, regmatch_t *match)
340 {
341         char *hit = strstr(line, pattern);
342         if (!hit) {
343                 match->rm_so = match->rm_eo = -1;
344                 return REG_NOMATCH;
345         }
346         else {
347                 match->rm_so = hit - line;
348                 match->rm_eo = match->rm_so + strlen(pattern);
349                 return 0;
350         }
351 }
352
353 static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol)
354 {
355         int hit = 0;
356         int at_true_bol = 1;
357         regmatch_t pmatch[10];
358
359  again:
360         if (!opt->fixed) {
361                 regex_t *exp = &p->regexp;
362                 hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
363                                pmatch, 0);
364         }
365         else {
366                 hit = !fixmatch(p->pattern, bol, pmatch);
367         }
368
369         if (hit && opt->word_regexp) {
370                 if ((pmatch[0].rm_so < 0) ||
371                     (eol - bol) <= pmatch[0].rm_so ||
372                     (pmatch[0].rm_eo < 0) ||
373                     (eol - bol) < pmatch[0].rm_eo)
374                         die("regexp returned nonsense");
375
376                 /* Match beginning must be either beginning of the
377                  * line, or at word boundary (i.e. the last char must
378                  * not be a word char).  Similarly, match end must be
379                  * either end of the line, or at word boundary
380                  * (i.e. the next char must not be a word char).
381                  */
382                 if ( ((pmatch[0].rm_so == 0 && at_true_bol) ||
383                       !word_char(bol[pmatch[0].rm_so-1])) &&
384                      ((pmatch[0].rm_eo == (eol-bol)) ||
385                       !word_char(bol[pmatch[0].rm_eo])) )
386                         ;
387                 else
388                         hit = 0;
389
390                 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
391                         /* There could be more than one match on the
392                          * line, and the first match might not be
393                          * strict word match.  But later ones could be!
394                          */
395                         bol = pmatch[0].rm_so + bol + 1;
396                         at_true_bol = 0;
397                         goto again;
398                 }
399         }
400         return hit;
401 }
402
403 static int match_expr_eval(struct grep_opt *opt,
404                            struct grep_expr *x,
405                            char *bol, char *eol)
406 {
407         switch (x->node) {
408         case GREP_NODE_ATOM:
409                 return match_one_pattern(opt, x->u.atom, bol, eol);
410                 break;
411         case GREP_NODE_NOT:
412                 return !match_expr_eval(opt, x->u.unary, bol, eol);
413         case GREP_NODE_AND:
414                 return (match_expr_eval(opt, x->u.binary.left, bol, eol) &&
415                         match_expr_eval(opt, x->u.binary.right, bol, eol));
416         case GREP_NODE_OR:
417                 return (match_expr_eval(opt, x->u.binary.left, bol, eol) ||
418                         match_expr_eval(opt, x->u.binary.right, bol, eol));
419         }
420         die("Unexpected node type (internal error) %d\n", x->node);
421 }
422
423 static int match_expr(struct grep_opt *opt, char *bol, char *eol)
424 {
425         struct grep_expr *x = opt->pattern_expression;
426         return match_expr_eval(opt, x, bol, eol);
427 }
428
429 static int match_line(struct grep_opt *opt, char *bol, char *eol)
430 {
431         struct grep_pat *p;
432         if (opt->extended)
433                 return match_expr(opt, bol, eol);
434         for (p = opt->pattern_list; p; p = p->next) {
435                 if (match_one_pattern(opt, p, bol, eol))
436                         return 1;
437         }
438         return 0;
439 }
440
441 static int grep_buffer(struct grep_opt *opt, const char *name,
442                        char *buf, unsigned long size)
443 {
444         char *bol = buf;
445         unsigned long left = size;
446         unsigned lno = 1;
447         struct pre_context_line {
448                 char *bol;
449                 char *eol;
450         } *prev = NULL, *pcl;
451         unsigned last_hit = 0;
452         unsigned last_shown = 0;
453         int binary_match_only = 0;
454         const char *hunk_mark = "";
455         unsigned count = 0;
456
457         if (buffer_is_binary(buf, size)) {
458                 switch (opt->binary) {
459                 case GREP_BINARY_DEFAULT:
460                         binary_match_only = 1;
461                         break;
462                 case GREP_BINARY_NOMATCH:
463                         return 0; /* Assume unmatch */
464                         break;
465                 default:
466                         break;
467                 }
468         }
469
470         if (opt->pre_context)
471                 prev = xcalloc(opt->pre_context, sizeof(*prev));
472         if (opt->pre_context || opt->post_context)
473                 hunk_mark = "--\n";
474
475         while (left) {
476                 char *eol, ch;
477                 int hit = 0;
478
479                 eol = end_of_line(bol, &left);
480                 ch = *eol;
481                 *eol = 0;
482
483                 hit = match_line(opt, bol, eol);
484
485                 /* "grep -v -e foo -e bla" should list lines
486                  * that do not have either, so inversion should
487                  * be done outside.
488                  */
489                 if (opt->invert)
490                         hit = !hit;
491                 if (opt->unmatch_name_only) {
492                         if (hit)
493                                 return 0;
494                         goto next_line;
495                 }
496                 if (hit) {
497                         count++;
498                         if (binary_match_only) {
499                                 printf("Binary file %s matches\n", name);
500                                 return 1;
501                         }
502                         if (opt->name_only) {
503                                 printf("%s\n", name);
504                                 return 1;
505                         }
506                         /* Hit at this line.  If we haven't shown the
507                          * pre-context lines, we would need to show them.
508                          * When asked to do "count", this still show
509                          * the context which is nonsense, but the user
510                          * deserves to get that ;-).
511                          */
512                         if (opt->pre_context) {
513                                 unsigned from;
514                                 if (opt->pre_context < lno)
515                                         from = lno - opt->pre_context;
516                                 else
517                                         from = 1;
518                                 if (from <= last_shown)
519                                         from = last_shown + 1;
520                                 if (last_shown && from != last_shown + 1)
521                                         printf(hunk_mark);
522                                 while (from < lno) {
523                                         pcl = &prev[lno-from-1];
524                                         show_line(opt, pcl->bol, pcl->eol,
525                                                   name, from, '-');
526                                         from++;
527                                 }
528                                 last_shown = lno-1;
529                         }
530                         if (last_shown && lno != last_shown + 1)
531                                 printf(hunk_mark);
532                         if (!opt->count)
533                                 show_line(opt, bol, eol, name, lno, ':');
534                         last_shown = last_hit = lno;
535                 }
536                 else if (last_hit &&
537                          lno <= last_hit + opt->post_context) {
538                         /* If the last hit is within the post context,
539                          * we need to show this line.
540                          */
541                         if (last_shown && lno != last_shown + 1)
542                                 printf(hunk_mark);
543                         show_line(opt, bol, eol, name, lno, '-');
544                         last_shown = lno;
545                 }
546                 if (opt->pre_context) {
547                         memmove(prev+1, prev,
548                                 (opt->pre_context-1) * sizeof(*prev));
549                         prev->bol = bol;
550                         prev->eol = eol;
551                 }
552
553         next_line:
554                 *eol = ch;
555                 bol = eol + 1;
556                 if (!left)
557                         break;
558                 left--;
559                 lno++;
560         }
561
562         if (opt->unmatch_name_only) {
563                 /* We did not see any hit, so we want to show this */
564                 printf("%s\n", name);
565                 return 1;
566         }
567
568         /* NEEDSWORK:
569          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
570          * which feels mostly useless but sometimes useful.  Maybe
571          * make it another option?  For now suppress them.
572          */
573         if (opt->count && count)
574                 printf("%s:%u\n", name, count);
575         return !!last_hit;
576 }
577
578 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
579 {
580         unsigned long size;
581         char *data;
582         char type[20];
583         char *to_free = NULL;
584         int hit;
585
586         data = read_sha1_file(sha1, type, &size);
587         if (!data) {
588                 error("'%s': unable to read %s", name, sha1_to_hex(sha1));
589                 return 0;
590         }
591         if (opt->relative && opt->prefix_length) {
592                 static char name_buf[PATH_MAX];
593                 char *cp;
594                 int name_len = strlen(name) - opt->prefix_length + 1;
595
596                 if (!tree_name_len)
597                         name += opt->prefix_length;
598                 else {
599                         if (ARRAY_SIZE(name_buf) <= name_len)
600                                 cp = to_free = xmalloc(name_len);
601                         else
602                                 cp = name_buf;
603                         memcpy(cp, name, tree_name_len);
604                         strcpy(cp + tree_name_len,
605                                name + tree_name_len + opt->prefix_length);
606                         name = cp;
607                 }
608         }
609         hit = grep_buffer(opt, name, data, size);
610         free(data);
611         free(to_free);
612         return hit;
613 }
614
615 static int grep_file(struct grep_opt *opt, const char *filename)
616 {
617         struct stat st;
618         int i;
619         char *data;
620         if (lstat(filename, &st) < 0) {
621         err_ret:
622                 if (errno != ENOENT)
623                         error("'%s': %s", filename, strerror(errno));
624                 return 0;
625         }
626         if (!st.st_size)
627                 return 0; /* empty file -- no grep hit */
628         if (!S_ISREG(st.st_mode))
629                 return 0;
630         i = open(filename, O_RDONLY);
631         if (i < 0)
632                 goto err_ret;
633         data = xmalloc(st.st_size + 1);
634         if (st.st_size != xread(i, data, st.st_size)) {
635                 error("'%s': short read %s", filename, strerror(errno));
636                 close(i);
637                 free(data);
638                 return 0;
639         }
640         close(i);
641         if (opt->relative && opt->prefix_length)
642                 filename += opt->prefix_length;
643         i = grep_buffer(opt, filename, data, st.st_size);
644         free(data);
645         return i;
646 }
647
648 static int exec_grep(int argc, const char **argv)
649 {
650         pid_t pid;
651         int status;
652
653         argv[argc] = NULL;
654         pid = fork();
655         if (pid < 0)
656                 return pid;
657         if (!pid) {
658                 execvp("grep", (char **) argv);
659                 exit(255);
660         }
661         while (waitpid(pid, &status, 0) < 0) {
662                 if (errno == EINTR)
663                         continue;
664                 return -1;
665         }
666         if (WIFEXITED(status)) {
667                 if (!WEXITSTATUS(status))
668                         return 1;
669                 return 0;
670         }
671         return -1;
672 }
673
674 #define MAXARGS 1000
675 #define ARGBUF 4096
676 #define push_arg(a) do { \
677         if (nr < MAXARGS) argv[nr++] = (a); \
678         else die("maximum number of args exceeded"); \
679         } while (0)
680
681 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
682 {
683         int i, nr, argc, hit, len, status;
684         const char *argv[MAXARGS+1];
685         char randarg[ARGBUF];
686         char *argptr = randarg;
687         struct grep_pat *p;
688
689         if (opt->extended || (opt->relative && opt->prefix_length))
690                 return -1;
691         len = nr = 0;
692         push_arg("grep");
693         if (opt->fixed)
694                 push_arg("-F");
695         if (opt->linenum)
696                 push_arg("-n");
697         if (opt->regflags & REG_EXTENDED)
698                 push_arg("-E");
699         if (opt->regflags & REG_ICASE)
700                 push_arg("-i");
701         if (opt->word_regexp)
702                 push_arg("-w");
703         if (opt->name_only)
704                 push_arg("-l");
705         if (opt->unmatch_name_only)
706                 push_arg("-L");
707         if (opt->count)
708                 push_arg("-c");
709         if (opt->post_context || opt->pre_context) {
710                 if (opt->post_context != opt->pre_context) {
711                         if (opt->pre_context) {
712                                 push_arg("-B");
713                                 len += snprintf(argptr, sizeof(randarg)-len,
714                                                 "%u", opt->pre_context);
715                                 if (sizeof(randarg) <= len)
716                                         die("maximum length of args exceeded");
717                                 push_arg(argptr);
718                                 argptr += len;
719                         }
720                         if (opt->post_context) {
721                                 push_arg("-A");
722                                 len += snprintf(argptr, sizeof(randarg)-len,
723                                                 "%u", opt->post_context);
724                                 if (sizeof(randarg) <= len)
725                                         die("maximum length of args exceeded");
726                                 push_arg(argptr);
727                                 argptr += len;
728                         }
729                 }
730                 else {
731                         push_arg("-C");
732                         len += snprintf(argptr, sizeof(randarg)-len,
733                                         "%u", opt->post_context);
734                         if (sizeof(randarg) <= len)
735                                 die("maximum length of args exceeded");
736                         push_arg(argptr);
737                         argptr += len;
738                 }
739         }
740         for (p = opt->pattern_list; p; p = p->next) {
741                 push_arg("-e");
742                 push_arg(p->pattern);
743         }
744
745         /*
746          * To make sure we get the header printed out when we want it,
747          * add /dev/null to the paths to grep.  This is unnecessary
748          * (and wrong) with "-l" or "-L", which always print out the
749          * name anyway.
750          *
751          * GNU grep has "-H", but this is portable.
752          */
753         if (!opt->name_only && !opt->unmatch_name_only)
754                 push_arg("/dev/null");
755
756         hit = 0;
757         argc = nr;
758         for (i = 0; i < active_nr; i++) {
759                 struct cache_entry *ce = active_cache[i];
760                 char *name;
761                 if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
762                         continue;
763                 if (!pathspec_matches(paths, ce->name))
764                         continue;
765                 name = ce->name;
766                 if (name[0] == '-') {
767                         int len = ce_namelen(ce);
768                         name = xmalloc(len + 3);
769                         memcpy(name, "./", 2);
770                         memcpy(name + 2, ce->name, len + 1);
771                 }
772                 argv[argc++] = name;
773                 if (argc < MAXARGS)
774                         continue;
775                 status = exec_grep(argc, argv);
776                 if (0 < status)
777                         hit = 1;
778                 argc = nr;
779         }
780         if (argc > nr) {
781                 status = exec_grep(argc, argv);
782                 if (0 < status)
783                         hit = 1;
784         }
785         return hit;
786 }
787
788 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
789 {
790         int hit = 0;
791         int nr;
792         read_cache();
793
794 #ifdef __unix__
795         /*
796          * Use the external "grep" command for the case where
797          * we grep through the checked-out files. It tends to
798          * be a lot more optimized
799          */
800         if (!cached) {
801                 hit = external_grep(opt, paths, cached);
802                 if (hit >= 0)
803                         return hit;
804         }
805 #endif
806
807         for (nr = 0; nr < active_nr; nr++) {
808                 struct cache_entry *ce = active_cache[nr];
809                 if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
810                         continue;
811                 if (!pathspec_matches(paths, ce->name))
812                         continue;
813                 if (cached)
814                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
815                 else
816                         hit |= grep_file(opt, ce->name);
817         }
818         return hit;
819 }
820
821 static int grep_tree(struct grep_opt *opt, const char **paths,
822                      struct tree_desc *tree,
823                      const char *tree_name, const char *base)
824 {
825         int len;
826         int hit = 0;
827         struct name_entry entry;
828         char *down;
829         int tn_len = strlen(tree_name);
830         char *path_buf = xmalloc(PATH_MAX + tn_len + 100);
831
832         if (tn_len) {
833                 tn_len = sprintf(path_buf, "%s:", tree_name);
834                 down = path_buf + tn_len;
835                 strcat(down, base);
836         }
837         else {
838                 down = path_buf;
839                 strcpy(down, base);
840         }
841         len = strlen(path_buf);
842
843         while (tree_entry(tree, &entry)) {
844                 strcpy(path_buf + len, entry.path);
845
846                 if (S_ISDIR(entry.mode))
847                         /* Match "abc/" against pathspec to
848                          * decide if we want to descend into "abc"
849                          * directory.
850                          */
851                         strcpy(path_buf + len + entry.pathlen, "/");
852
853                 if (!pathspec_matches(paths, down))
854                         ;
855                 else if (S_ISREG(entry.mode))
856                         hit |= grep_sha1(opt, entry.sha1, path_buf, tn_len);
857                 else if (S_ISDIR(entry.mode)) {
858                         char type[20];
859                         struct tree_desc sub;
860                         void *data;
861                         data = read_sha1_file(entry.sha1, type, &sub.size);
862                         if (!data)
863                                 die("unable to read tree (%s)",
864                                     sha1_to_hex(entry.sha1));
865                         sub.buf = data;
866                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
867                         free(data);
868                 }
869         }
870         return hit;
871 }
872
873 static int grep_object(struct grep_opt *opt, const char **paths,
874                        struct object *obj, const char *name)
875 {
876         if (obj->type == OBJ_BLOB)
877                 return grep_sha1(opt, obj->sha1, name, 0);
878         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
879                 struct tree_desc tree;
880                 void *data;
881                 int hit;
882                 data = read_object_with_reference(obj->sha1, tree_type,
883                                                   &tree.size, NULL);
884                 if (!data)
885                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
886                 tree.buf = data;
887                 hit = grep_tree(opt, paths, &tree, name, "");
888                 free(data);
889                 return hit;
890         }
891         die("unable to grep from object of type %s", typename(obj->type));
892 }
893
894 static const char builtin_grep_usage[] =
895 "git-grep <option>* <rev>* [-e] <pattern> [<path>...]";
896
897 static const char emsg_invalid_context_len[] =
898 "%s: invalid context length argument";
899 static const char emsg_missing_context_len[] =
900 "missing context length argument";
901 static const char emsg_missing_argument[] =
902 "option requires an argument -%s";
903
904 int cmd_grep(int argc, const char **argv, const char *prefix)
905 {
906         int hit = 0;
907         int cached = 0;
908         int seen_dashdash = 0;
909         struct grep_opt opt;
910         struct object_array list = { 0, 0, NULL };
911         const char **paths = NULL;
912         int i;
913
914         memset(&opt, 0, sizeof(opt));
915         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
916         opt.relative = 1;
917         opt.pattern_tail = &opt.pattern_list;
918         opt.regflags = REG_NEWLINE;
919
920         /*
921          * If there is no -- then the paths must exist in the working
922          * tree.  If there is no explicit pattern specified with -e or
923          * -f, we take the first unrecognized non option to be the
924          * pattern, but then what follows it must be zero or more
925          * valid refs up to the -- (if exists), and then existing
926          * paths.  If there is an explicit pattern, then the first
927          * unrecognized non option is the beginning of the refs list
928          * that continues up to the -- (if exists), and then paths.
929          */
930
931         while (1 < argc) {
932                 const char *arg = argv[1];
933                 argc--; argv++;
934                 if (!strcmp("--cached", arg)) {
935                         cached = 1;
936                         continue;
937                 }
938                 if (!strcmp("-a", arg) ||
939                     !strcmp("--text", arg)) {
940                         opt.binary = GREP_BINARY_TEXT;
941                         continue;
942                 }
943                 if (!strcmp("-i", arg) ||
944                     !strcmp("--ignore-case", arg)) {
945                         opt.regflags |= REG_ICASE;
946                         continue;
947                 }
948                 if (!strcmp("-I", arg)) {
949                         opt.binary = GREP_BINARY_NOMATCH;
950                         continue;
951                 }
952                 if (!strcmp("-v", arg) ||
953                     !strcmp("--invert-match", arg)) {
954                         opt.invert = 1;
955                         continue;
956                 }
957                 if (!strcmp("-E", arg) ||
958                     !strcmp("--extended-regexp", arg)) {
959                         opt.regflags |= REG_EXTENDED;
960                         continue;
961                 }
962                 if (!strcmp("-F", arg) ||
963                     !strcmp("--fixed-strings", arg)) {
964                         opt.fixed = 1;
965                         continue;
966                 }
967                 if (!strcmp("-G", arg) ||
968                     !strcmp("--basic-regexp", arg)) {
969                         opt.regflags &= ~REG_EXTENDED;
970                         continue;
971                 }
972                 if (!strcmp("-n", arg)) {
973                         opt.linenum = 1;
974                         continue;
975                 }
976                 if (!strcmp("-H", arg)) {
977                         /* We always show the pathname, so this
978                          * is a noop.
979                          */
980                         continue;
981                 }
982                 if (!strcmp("-l", arg) ||
983                     !strcmp("--files-with-matches", arg)) {
984                         opt.name_only = 1;
985                         continue;
986                 }
987                 if (!strcmp("-L", arg) ||
988                     !strcmp("--files-without-match", arg)) {
989                         opt.unmatch_name_only = 1;
990                         continue;
991                 }
992                 if (!strcmp("-c", arg) ||
993                     !strcmp("--count", arg)) {
994                         opt.count = 1;
995                         continue;
996                 }
997                 if (!strcmp("-w", arg) ||
998                     !strcmp("--word-regexp", arg)) {
999                         opt.word_regexp = 1;
1000                         continue;
1001                 }
1002                 if (!strncmp("-A", arg, 2) ||
1003                     !strncmp("-B", arg, 2) ||
1004                     !strncmp("-C", arg, 2) ||
1005                     (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
1006                         unsigned num;
1007                         const char *scan;
1008                         switch (arg[1]) {
1009                         case 'A': case 'B': case 'C':
1010                                 if (!arg[2]) {
1011                                         if (argc <= 1)
1012                                                 die(emsg_missing_context_len);
1013                                         scan = *++argv;
1014                                         argc--;
1015                                 }
1016                                 else
1017                                         scan = arg + 2;
1018                                 break;
1019                         default:
1020                                 scan = arg + 1;
1021                                 break;
1022                         }
1023                         if (sscanf(scan, "%u", &num) != 1)
1024                                 die(emsg_invalid_context_len, scan);
1025                         switch (arg[1]) {
1026                         case 'A':
1027                                 opt.post_context = num;
1028                                 break;
1029                         default:
1030                         case 'C':
1031                                 opt.post_context = num;
1032                         case 'B':
1033                                 opt.pre_context = num;
1034                                 break;
1035                         }
1036                         continue;
1037                 }
1038                 if (!strcmp("-f", arg)) {
1039                         FILE *patterns;
1040                         int lno = 0;
1041                         char buf[1024];
1042                         if (argc <= 1)
1043                                 die(emsg_missing_argument, arg);
1044                         patterns = fopen(argv[1], "r");
1045                         if (!patterns)
1046                                 die("'%s': %s", argv[1], strerror(errno));
1047                         while (fgets(buf, sizeof(buf), patterns)) {
1048                                 int len = strlen(buf);
1049                                 if (buf[len-1] == '\n')
1050                                         buf[len-1] = 0;
1051                                 /* ignore empty line like grep does */
1052                                 if (!buf[0])
1053                                         continue;
1054                                 add_pattern(&opt, strdup(buf), argv[1], ++lno,
1055                                             GREP_PATTERN);
1056                         }
1057                         fclose(patterns);
1058                         argv++;
1059                         argc--;
1060                         continue;
1061                 }
1062                 if (!strcmp("--not", arg)) {
1063                         add_pattern(&opt, arg, "command line", 0, GREP_NOT);
1064                         continue;
1065                 }
1066                 if (!strcmp("--and", arg)) {
1067                         add_pattern(&opt, arg, "command line", 0, GREP_AND);
1068                         continue;
1069                 }
1070                 if (!strcmp("--or", arg))
1071                         continue; /* no-op */
1072                 if (!strcmp("(", arg)) {
1073                         add_pattern(&opt, arg, "command line", 0, GREP_OPEN_PAREN);
1074                         continue;
1075                 }
1076                 if (!strcmp(")", arg)) {
1077                         add_pattern(&opt, arg, "command line", 0, GREP_CLOSE_PAREN);
1078                         continue;
1079                 }
1080                 if (!strcmp("-e", arg)) {
1081                         if (1 < argc) {
1082                                 add_pattern(&opt, argv[1], "-e option", 0,
1083                                             GREP_PATTERN);
1084                                 argv++;
1085                                 argc--;
1086                                 continue;
1087                         }
1088                         die(emsg_missing_argument, arg);
1089                 }
1090                 if (!strcmp("--full-name", arg)) {
1091                         opt.relative = 0;
1092                         continue;
1093                 }
1094                 if (!strcmp("--", arg)) {
1095                         /* later processing wants to have this at argv[1] */
1096                         argv--;
1097                         argc++;
1098                         break;
1099                 }
1100                 if (*arg == '-')
1101                         usage(builtin_grep_usage);
1102
1103                 /* First unrecognized non-option token */
1104                 if (!opt.pattern_list) {
1105                         add_pattern(&opt, arg, "command line", 0,
1106                                     GREP_PATTERN);
1107                         break;
1108                 }
1109                 else {
1110                         /* We are looking at the first path or rev;
1111                          * it is found at argv[1] after leaving the
1112                          * loop.
1113                          */
1114                         argc++; argv--;
1115                         break;
1116                 }
1117         }
1118
1119         if (!opt.pattern_list)
1120                 die("no pattern given.");
1121         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
1122                 die("cannot mix --fixed-strings and regexp");
1123         if (!opt.fixed)
1124                 compile_patterns(&opt);
1125
1126         /* Check revs and then paths */
1127         for (i = 1; i < argc; i++) {
1128                 const char *arg = argv[i];
1129                 unsigned char sha1[20];
1130                 /* Is it a rev? */
1131                 if (!get_sha1(arg, sha1)) {
1132                         struct object *object = parse_object(sha1);
1133                         if (!object)
1134                                 die("bad object %s", arg);
1135                         add_object_array(object, arg, &list);
1136                         continue;
1137                 }
1138                 if (!strcmp(arg, "--")) {
1139                         i++;
1140                         seen_dashdash = 1;
1141                 }
1142                 break;
1143         }
1144
1145         /* The rest are paths */
1146         if (!seen_dashdash) {
1147                 int j;
1148                 for (j = i; j < argc; j++)
1149                         verify_filename(prefix, argv[j]);
1150         }
1151
1152         if (i < argc) {
1153                 paths = get_pathspec(prefix, argv + i);
1154                 if (opt.prefix_length && opt.relative) {
1155                         /* Make sure we do not get outside of paths */
1156                         for (i = 0; paths[i]; i++)
1157                                 if (strncmp(prefix, paths[i], opt.prefix_length))
1158                                         die("git-grep: cannot generate relative filenames containing '..'");
1159                 }
1160         }
1161         else if (prefix) {
1162                 paths = xcalloc(2, sizeof(const char *));
1163                 paths[0] = prefix;
1164                 paths[1] = NULL;
1165         }
1166
1167         if (!list.nr)
1168                 return !grep_cache(&opt, paths, cached);
1169
1170         if (cached)
1171                 die("both --cached and trees are given.");
1172
1173         for (i = 0; i < list.nr; i++) {
1174                 struct object *real_obj;
1175                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
1176                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
1177                         hit = 1;
1178         }
1179         return !hit;
1180 }