Code

rm git-rerere.perl -- it is now a built-in.
[git.git] / grep.c
1 #include "cache.h"
2 #include "grep.h"
4 void append_grep_pattern(struct grep_opt *opt, const char *pat,
5                          const char *origin, int no, enum grep_pat_token t)
6 {
7         struct grep_pat *p = xcalloc(1, sizeof(*p));
8         p->pattern = pat;
9         p->origin = origin;
10         p->no = no;
11         p->token = t;
12         *opt->pattern_tail = p;
13         opt->pattern_tail = &p->next;
14         p->next = NULL;
15 }
17 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
18 {
19         int err = regcomp(&p->regexp, p->pattern, opt->regflags);
20         if (err) {
21                 char errbuf[1024];
22                 char where[1024];
23                 if (p->no)
24                         sprintf(where, "In '%s' at %d, ",
25                                 p->origin, p->no);
26                 else if (p->origin)
27                         sprintf(where, "%s, ", p->origin);
28                 else
29                         where[0] = 0;
30                 regerror(err, &p->regexp, errbuf, 1024);
31                 regfree(&p->regexp);
32                 die("%s'%s': %s", where, p->pattern, errbuf);
33         }
34 }
36 static struct grep_expr *compile_pattern_or(struct grep_pat **);
37 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
38 {
39         struct grep_pat *p;
40         struct grep_expr *x;
42         p = *list;
43         switch (p->token) {
44         case GREP_PATTERN: /* atom */
45         case GREP_PATTERN_HEAD:
46         case GREP_PATTERN_BODY:
47                 x = xcalloc(1, sizeof (struct grep_expr));
48                 x->node = GREP_NODE_ATOM;
49                 x->u.atom = p;
50                 *list = p->next;
51                 return x;
52         case GREP_OPEN_PAREN:
53                 *list = p->next;
54                 x = compile_pattern_or(list);
55                 if (!x)
56                         return NULL;
57                 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
58                         die("unmatched parenthesis");
59                 *list = (*list)->next;
60                 return x;
61         default:
62                 return NULL;
63         }
64 }
66 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
67 {
68         struct grep_pat *p;
69         struct grep_expr *x;
71         p = *list;
72         switch (p->token) {
73         case GREP_NOT:
74                 if (!p->next)
75                         die("--not not followed by pattern expression");
76                 *list = p->next;
77                 x = xcalloc(1, sizeof (struct grep_expr));
78                 x->node = GREP_NODE_NOT;
79                 x->u.unary = compile_pattern_not(list);
80                 if (!x->u.unary)
81                         die("--not followed by non pattern expression");
82                 return x;
83         default:
84                 return compile_pattern_atom(list);
85         }
86 }
88 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
89 {
90         struct grep_pat *p;
91         struct grep_expr *x, *y, *z;
93         x = compile_pattern_not(list);
94         p = *list;
95         if (p && p->token == GREP_AND) {
96                 if (!p->next)
97                         die("--and not followed by pattern expression");
98                 *list = p->next;
99                 y = compile_pattern_and(list);
100                 if (!y)
101                         die("--and not followed by pattern expression");
102                 z = xcalloc(1, sizeof (struct grep_expr));
103                 z->node = GREP_NODE_AND;
104                 z->u.binary.left = x;
105                 z->u.binary.right = y;
106                 return z;
107         }
108         return x;
111 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
113         struct grep_pat *p;
114         struct grep_expr *x, *y, *z;
116         x = compile_pattern_and(list);
117         p = *list;
118         if (x && p && p->token != GREP_CLOSE_PAREN) {
119                 y = compile_pattern_or(list);
120                 if (!y)
121                         die("not a pattern expression %s", p->pattern);
122                 z = xcalloc(1, sizeof (struct grep_expr));
123                 z->node = GREP_NODE_OR;
124                 z->u.binary.left = x;
125                 z->u.binary.right = y;
126                 return z;
127         }
128         return x;
131 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
133         return compile_pattern_or(list);
136 void compile_grep_patterns(struct grep_opt *opt)
138         struct grep_pat *p;
140         if (opt->all_match)
141                 opt->extended = 1;
143         for (p = opt->pattern_list; p; p = p->next) {
144                 switch (p->token) {
145                 case GREP_PATTERN: /* atom */
146                 case GREP_PATTERN_HEAD:
147                 case GREP_PATTERN_BODY:
148                         if (!opt->fixed)
149                                 compile_regexp(p, opt);
150                         break;
151                 default:
152                         opt->extended = 1;
153                         break;
154                 }
155         }
157         if (!opt->extended)
158                 return;
160         /* Then bundle them up in an expression.
161          * A classic recursive descent parser would do.
162          */
163         p = opt->pattern_list;
164         opt->pattern_expression = compile_pattern_expr(&p);
165         if (p)
166                 die("incomplete pattern expression: %s", p->pattern);
169 static void free_pattern_expr(struct grep_expr *x)
171         switch (x->node) {
172         case GREP_NODE_ATOM:
173                 break;
174         case GREP_NODE_NOT:
175                 free_pattern_expr(x->u.unary);
176                 break;
177         case GREP_NODE_AND:
178         case GREP_NODE_OR:
179                 free_pattern_expr(x->u.binary.left);
180                 free_pattern_expr(x->u.binary.right);
181                 break;
182         }
183         free(x);
186 void free_grep_patterns(struct grep_opt *opt)
188         struct grep_pat *p, *n;
190         for (p = opt->pattern_list; p; p = n) {
191                 n = p->next;
192                 switch (p->token) {
193                 case GREP_PATTERN: /* atom */
194                 case GREP_PATTERN_HEAD:
195                 case GREP_PATTERN_BODY:
196                         regfree(&p->regexp);
197                         break;
198                 default:
199                         break;
200                 }
201                 free(p);
202         }
204         if (!opt->extended)
205                 return;
206         free_pattern_expr(opt->pattern_expression);
209 static char *end_of_line(char *cp, unsigned long *left)
211         unsigned long l = *left;
212         while (l && *cp != '\n') {
213                 l--;
214                 cp++;
215         }
216         *left = l;
217         return cp;
220 static int word_char(char ch)
222         return isalnum(ch) || ch == '_';
225 static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
226                       const char *name, unsigned lno, char sign)
228         if (opt->pathname)
229                 printf("%s%c", name, sign);
230         if (opt->linenum)
231                 printf("%d%c", lno, sign);
232         printf("%.*s\n", (int)(eol-bol), bol);
235 /*
236  * NEEDSWORK: share code with diff.c
237  */
238 #define FIRST_FEW_BYTES 8000
239 static int buffer_is_binary(const char *ptr, unsigned long size)
241         if (FIRST_FEW_BYTES < size)
242                 size = FIRST_FEW_BYTES;
243         return !!memchr(ptr, 0, size);
246 static int fixmatch(const char *pattern, char *line, regmatch_t *match)
248         char *hit = strstr(line, pattern);
249         if (!hit) {
250                 match->rm_so = match->rm_eo = -1;
251                 return REG_NOMATCH;
252         }
253         else {
254                 match->rm_so = hit - line;
255                 match->rm_eo = match->rm_so + strlen(pattern);
256                 return 0;
257         }
260 static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol, enum grep_context ctx)
262         int hit = 0;
263         int at_true_bol = 1;
264         regmatch_t pmatch[10];
266         if ((p->token != GREP_PATTERN) &&
267             ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
268                 return 0;
270  again:
271         if (!opt->fixed) {
272                 regex_t *exp = &p->regexp;
273                 hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
274                                pmatch, 0);
275         }
276         else {
277                 hit = !fixmatch(p->pattern, bol, pmatch);
278         }
280         if (hit && opt->word_regexp) {
281                 if ((pmatch[0].rm_so < 0) ||
282                     (eol - bol) <= pmatch[0].rm_so ||
283                     (pmatch[0].rm_eo < 0) ||
284                     (eol - bol) < pmatch[0].rm_eo)
285                         die("regexp returned nonsense");
287                 /* Match beginning must be either beginning of the
288                  * line, or at word boundary (i.e. the last char must
289                  * not be a word char).  Similarly, match end must be
290                  * either end of the line, or at word boundary
291                  * (i.e. the next char must not be a word char).
292                  */
293                 if ( ((pmatch[0].rm_so == 0 && at_true_bol) ||
294                       !word_char(bol[pmatch[0].rm_so-1])) &&
295                      ((pmatch[0].rm_eo == (eol-bol)) ||
296                       !word_char(bol[pmatch[0].rm_eo])) )
297                         ;
298                 else
299                         hit = 0;
301                 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
302                         /* There could be more than one match on the
303                          * line, and the first match might not be
304                          * strict word match.  But later ones could be!
305                          */
306                         bol = pmatch[0].rm_so + bol + 1;
307                         at_true_bol = 0;
308                         goto again;
309                 }
310         }
311         return hit;
314 static int match_expr_eval(struct grep_opt *o,
315                            struct grep_expr *x,
316                            char *bol, char *eol,
317                            enum grep_context ctx,
318                            int collect_hits)
320         int h = 0;
322         switch (x->node) {
323         case GREP_NODE_ATOM:
324                 h = match_one_pattern(o, x->u.atom, bol, eol, ctx);
325                 break;
326         case GREP_NODE_NOT:
327                 h = !match_expr_eval(o, x->u.unary, bol, eol, ctx, 0);
328                 break;
329         case GREP_NODE_AND:
330                 if (!collect_hits)
331                         return (match_expr_eval(o, x->u.binary.left,
332                                                 bol, eol, ctx, 0) &&
333                                 match_expr_eval(o, x->u.binary.right,
334                                                 bol, eol, ctx, 0));
335                 h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0);
336                 h &= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 0);
337                 break;
338         case GREP_NODE_OR:
339                 if (!collect_hits)
340                         return (match_expr_eval(o, x->u.binary.left,
341                                                 bol, eol, ctx, 0) ||
342                                 match_expr_eval(o, x->u.binary.right,
343                                                 bol, eol, ctx, 0));
344                 h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0);
345                 x->u.binary.left->hit |= h;
346                 h |= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 1);
347                 break;
348         default:
349                 die("Unexpected node type (internal error) %d\n", x->node);
350         }
351         if (collect_hits)
352                 x->hit |= h;
353         return h;
356 static int match_expr(struct grep_opt *opt, char *bol, char *eol,
357                       enum grep_context ctx, int collect_hits)
359         struct grep_expr *x = opt->pattern_expression;
360         return match_expr_eval(opt, x, bol, eol, ctx, collect_hits);
363 static int match_line(struct grep_opt *opt, char *bol, char *eol,
364                       enum grep_context ctx, int collect_hits)
366         struct grep_pat *p;
367         if (opt->extended)
368                 return match_expr(opt, bol, eol, ctx, collect_hits);
370         /* we do not call with collect_hits without being extended */
371         for (p = opt->pattern_list; p; p = p->next) {
372                 if (match_one_pattern(opt, p, bol, eol, ctx))
373                         return 1;
374         }
375         return 0;
378 static int grep_buffer_1(struct grep_opt *opt, const char *name,
379                          char *buf, unsigned long size, int collect_hits)
381         char *bol = buf;
382         unsigned long left = size;
383         unsigned lno = 1;
384         struct pre_context_line {
385                 char *bol;
386                 char *eol;
387         } *prev = NULL, *pcl;
388         unsigned last_hit = 0;
389         unsigned last_shown = 0;
390         int binary_match_only = 0;
391         const char *hunk_mark = "";
392         unsigned count = 0;
393         enum grep_context ctx = GREP_CONTEXT_HEAD;
395         if (buffer_is_binary(buf, size)) {
396                 switch (opt->binary) {
397                 case GREP_BINARY_DEFAULT:
398                         binary_match_only = 1;
399                         break;
400                 case GREP_BINARY_NOMATCH:
401                         return 0; /* Assume unmatch */
402                         break;
403                 default:
404                         break;
405                 }
406         }
408         if (opt->pre_context)
409                 prev = xcalloc(opt->pre_context, sizeof(*prev));
410         if (opt->pre_context || opt->post_context)
411                 hunk_mark = "--\n";
413         while (left) {
414                 char *eol, ch;
415                 int hit;
417                 eol = end_of_line(bol, &left);
418                 ch = *eol;
419                 *eol = 0;
421                 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
422                         ctx = GREP_CONTEXT_BODY;
424                 hit = match_line(opt, bol, eol, ctx, collect_hits);
425                 *eol = ch;
427                 if (collect_hits)
428                         goto next_line;
430                 /* "grep -v -e foo -e bla" should list lines
431                  * that do not have either, so inversion should
432                  * be done outside.
433                  */
434                 if (opt->invert)
435                         hit = !hit;
436                 if (opt->unmatch_name_only) {
437                         if (hit)
438                                 return 0;
439                         goto next_line;
440                 }
441                 if (hit) {
442                         count++;
443                         if (opt->status_only)
444                                 return 1;
445                         if (binary_match_only) {
446                                 printf("Binary file %s matches\n", name);
447                                 return 1;
448                         }
449                         if (opt->name_only) {
450                                 printf("%s\n", name);
451                                 return 1;
452                         }
453                         /* Hit at this line.  If we haven't shown the
454                          * pre-context lines, we would need to show them.
455                          * When asked to do "count", this still show
456                          * the context which is nonsense, but the user
457                          * deserves to get that ;-).
458                          */
459                         if (opt->pre_context) {
460                                 unsigned from;
461                                 if (opt->pre_context < lno)
462                                         from = lno - opt->pre_context;
463                                 else
464                                         from = 1;
465                                 if (from <= last_shown)
466                                         from = last_shown + 1;
467                                 if (last_shown && from != last_shown + 1)
468                                         printf(hunk_mark);
469                                 while (from < lno) {
470                                         pcl = &prev[lno-from-1];
471                                         show_line(opt, pcl->bol, pcl->eol,
472                                                   name, from, '-');
473                                         from++;
474                                 }
475                                 last_shown = lno-1;
476                         }
477                         if (last_shown && lno != last_shown + 1)
478                                 printf(hunk_mark);
479                         if (!opt->count)
480                                 show_line(opt, bol, eol, name, lno, ':');
481                         last_shown = last_hit = lno;
482                 }
483                 else if (last_hit &&
484                          lno <= last_hit + opt->post_context) {
485                         /* If the last hit is within the post context,
486                          * we need to show this line.
487                          */
488                         if (last_shown && lno != last_shown + 1)
489                                 printf(hunk_mark);
490                         show_line(opt, bol, eol, name, lno, '-');
491                         last_shown = lno;
492                 }
493                 if (opt->pre_context) {
494                         memmove(prev+1, prev,
495                                 (opt->pre_context-1) * sizeof(*prev));
496                         prev->bol = bol;
497                         prev->eol = eol;
498                 }
500         next_line:
501                 bol = eol + 1;
502                 if (!left)
503                         break;
504                 left--;
505                 lno++;
506         }
508         free(prev);
509         if (collect_hits)
510                 return 0;
512         if (opt->status_only)
513                 return 0;
514         if (opt->unmatch_name_only) {
515                 /* We did not see any hit, so we want to show this */
516                 printf("%s\n", name);
517                 return 1;
518         }
520         /* NEEDSWORK:
521          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
522          * which feels mostly useless but sometimes useful.  Maybe
523          * make it another option?  For now suppress them.
524          */
525         if (opt->count && count)
526                 printf("%s:%u\n", name, count);
527         return !!last_hit;
530 static void clr_hit_marker(struct grep_expr *x)
532         /* All-hit markers are meaningful only at the very top level
533          * OR node.
534          */
535         while (1) {
536                 x->hit = 0;
537                 if (x->node != GREP_NODE_OR)
538                         return;
539                 x->u.binary.left->hit = 0;
540                 x = x->u.binary.right;
541         }
544 static int chk_hit_marker(struct grep_expr *x)
546         /* Top level nodes have hit markers.  See if they all are hits */
547         while (1) {
548                 if (x->node != GREP_NODE_OR)
549                         return x->hit;
550                 if (!x->u.binary.left->hit)
551                         return 0;
552                 x = x->u.binary.right;
553         }
556 int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
558         /*
559          * we do not have to do the two-pass grep when we do not check
560          * buffer-wide "all-match".
561          */
562         if (!opt->all_match)
563                 return grep_buffer_1(opt, name, buf, size, 0);
565         /* Otherwise the toplevel "or" terms hit a bit differently.
566          * We first clear hit markers from them.
567          */
568         clr_hit_marker(opt->pattern_expression);
569         grep_buffer_1(opt, name, buf, size, 1);
571         if (!chk_hit_marker(opt->pattern_expression))
572                 return 0;
574         return grep_buffer_1(opt, name, buf, size, 0);