git-svn: fix log with single revision against a non-HEAD branch
[git/dscho.git] / grep.c
blobf67d6716ea5f42c3384a7a4cb2eb973b02785fba
1 #include "cache.h"
2 #include "grep.h"
3 #include "xdiff-interface.h"
5 void append_grep_pattern(struct grep_opt *opt, const char *pat,
6                          const char *origin, int no, enum grep_pat_token t)
8         struct grep_pat *p = xcalloc(1, sizeof(*p));
9         p->pattern = pat;
10         p->origin = origin;
11         p->no = no;
12         p->token = t;
13         *opt->pattern_tail = p;
14         opt->pattern_tail = &p->next;
15         p->next = NULL;
18 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
20         int err = regcomp(&p->regexp, p->pattern, opt->regflags);
21         if (err) {
22                 char errbuf[1024];
23                 char where[1024];
24                 if (p->no)
25                         sprintf(where, "In '%s' at %d, ",
26                                 p->origin, p->no);
27                 else if (p->origin)
28                         sprintf(where, "%s, ", p->origin);
29                 else
30                         where[0] = 0;
31                 regerror(err, &p->regexp, errbuf, 1024);
32                 regfree(&p->regexp);
33                 die("%s'%s': %s", where, p->pattern, errbuf);
34         }
37 static struct grep_expr *compile_pattern_or(struct grep_pat **);
38 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
40         struct grep_pat *p;
41         struct grep_expr *x;
43         p = *list;
44         switch (p->token) {
45         case GREP_PATTERN: /* atom */
46         case GREP_PATTERN_HEAD:
47         case GREP_PATTERN_BODY:
48                 x = xcalloc(1, sizeof (struct grep_expr));
49                 x->node = GREP_NODE_ATOM;
50                 x->u.atom = p;
51                 *list = p->next;
52                 return x;
53         case GREP_OPEN_PAREN:
54                 *list = p->next;
55                 x = compile_pattern_or(list);
56                 if (!x)
57                         return NULL;
58                 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
59                         die("unmatched parenthesis");
60                 *list = (*list)->next;
61                 return x;
62         default:
63                 return NULL;
64         }
67 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
69         struct grep_pat *p;
70         struct grep_expr *x;
72         p = *list;
73         switch (p->token) {
74         case GREP_NOT:
75                 if (!p->next)
76                         die("--not not followed by pattern expression");
77                 *list = p->next;
78                 x = xcalloc(1, sizeof (struct grep_expr));
79                 x->node = GREP_NODE_NOT;
80                 x->u.unary = compile_pattern_not(list);
81                 if (!x->u.unary)
82                         die("--not followed by non pattern expression");
83                 return x;
84         default:
85                 return compile_pattern_atom(list);
86         }
89 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
91         struct grep_pat *p;
92         struct grep_expr *x, *y, *z;
94         x = compile_pattern_not(list);
95         p = *list;
96         if (p && p->token == GREP_AND) {
97                 if (!p->next)
98                         die("--and not followed by pattern expression");
99                 *list = p->next;
100                 y = compile_pattern_and(list);
101                 if (!y)
102                         die("--and not followed by pattern expression");
103                 z = xcalloc(1, sizeof (struct grep_expr));
104                 z->node = GREP_NODE_AND;
105                 z->u.binary.left = x;
106                 z->u.binary.right = y;
107                 return z;
108         }
109         return x;
112 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
114         struct grep_pat *p;
115         struct grep_expr *x, *y, *z;
117         x = compile_pattern_and(list);
118         p = *list;
119         if (x && p && p->token != GREP_CLOSE_PAREN) {
120                 y = compile_pattern_or(list);
121                 if (!y)
122                         die("not a pattern expression %s", p->pattern);
123                 z = xcalloc(1, sizeof (struct grep_expr));
124                 z->node = GREP_NODE_OR;
125                 z->u.binary.left = x;
126                 z->u.binary.right = y;
127                 return z;
128         }
129         return x;
132 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
134         return compile_pattern_or(list);
137 void compile_grep_patterns(struct grep_opt *opt)
139         struct grep_pat *p;
141         if (opt->all_match)
142                 opt->extended = 1;
144         for (p = opt->pattern_list; p; p = p->next) {
145                 switch (p->token) {
146                 case GREP_PATTERN: /* atom */
147                 case GREP_PATTERN_HEAD:
148                 case GREP_PATTERN_BODY:
149                         if (!opt->fixed)
150                                 compile_regexp(p, opt);
151                         break;
152                 default:
153                         opt->extended = 1;
154                         break;
155                 }
156         }
158         if (!opt->extended)
159                 return;
161         /* Then bundle them up in an expression.
162          * A classic recursive descent parser would do.
163          */
164         p = opt->pattern_list;
165         opt->pattern_expression = compile_pattern_expr(&p);
166         if (p)
167                 die("incomplete pattern expression: %s", p->pattern);
170 static void free_pattern_expr(struct grep_expr *x)
172         switch (x->node) {
173         case GREP_NODE_ATOM:
174                 break;
175         case GREP_NODE_NOT:
176                 free_pattern_expr(x->u.unary);
177                 break;
178         case GREP_NODE_AND:
179         case GREP_NODE_OR:
180                 free_pattern_expr(x->u.binary.left);
181                 free_pattern_expr(x->u.binary.right);
182                 break;
183         }
184         free(x);
187 void free_grep_patterns(struct grep_opt *opt)
189         struct grep_pat *p, *n;
191         for (p = opt->pattern_list; p; p = n) {
192                 n = p->next;
193                 switch (p->token) {
194                 case GREP_PATTERN: /* atom */
195                 case GREP_PATTERN_HEAD:
196                 case GREP_PATTERN_BODY:
197                         regfree(&p->regexp);
198                         break;
199                 default:
200                         break;
201                 }
202                 free(p);
203         }
205         if (!opt->extended)
206                 return;
207         free_pattern_expr(opt->pattern_expression);
210 static char *end_of_line(char *cp, unsigned long *left)
212         unsigned long l = *left;
213         while (l && *cp != '\n') {
214                 l--;
215                 cp++;
216         }
217         *left = l;
218         return cp;
221 static int word_char(char ch)
223         return isalnum(ch) || ch == '_';
226 static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
227                       const char *name, unsigned lno, char sign)
229         if (opt->pathname)
230                 printf("%s%c", name, sign);
231         if (opt->linenum)
232                 printf("%d%c", lno, sign);
233         printf("%.*s\n", (int)(eol-bol), bol);
236 static int fixmatch(const char *pattern, char *line, regmatch_t *match)
238         char *hit = strstr(line, pattern);
239         if (!hit) {
240                 match->rm_so = match->rm_eo = -1;
241                 return REG_NOMATCH;
242         }
243         else {
244                 match->rm_so = hit - line;
245                 match->rm_eo = match->rm_so + strlen(pattern);
246                 return 0;
247         }
250 static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol, enum grep_context ctx)
252         int hit = 0;
253         int at_true_bol = 1;
254         regmatch_t pmatch[10];
256         if ((p->token != GREP_PATTERN) &&
257             ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
258                 return 0;
260  again:
261         if (!opt->fixed) {
262                 regex_t *exp = &p->regexp;
263                 hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
264                                pmatch, 0);
265         }
266         else {
267                 hit = !fixmatch(p->pattern, bol, pmatch);
268         }
270         if (hit && opt->word_regexp) {
271                 if ((pmatch[0].rm_so < 0) ||
272                     (eol - bol) <= pmatch[0].rm_so ||
273                     (pmatch[0].rm_eo < 0) ||
274                     (eol - bol) < pmatch[0].rm_eo)
275                         die("regexp returned nonsense");
277                 /* Match beginning must be either beginning of the
278                  * line, or at word boundary (i.e. the last char must
279                  * not be a word char).  Similarly, match end must be
280                  * either end of the line, or at word boundary
281                  * (i.e. the next char must not be a word char).
282                  */
283                 if ( ((pmatch[0].rm_so == 0 && at_true_bol) ||
284                       !word_char(bol[pmatch[0].rm_so-1])) &&
285                      ((pmatch[0].rm_eo == (eol-bol)) ||
286                       !word_char(bol[pmatch[0].rm_eo])) )
287                         ;
288                 else
289                         hit = 0;
291                 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
292                         /* There could be more than one match on the
293                          * line, and the first match might not be
294                          * strict word match.  But later ones could be!
295                          */
296                         bol = pmatch[0].rm_so + bol + 1;
297                         at_true_bol = 0;
298                         goto again;
299                 }
300         }
301         return hit;
304 static int match_expr_eval(struct grep_opt *o,
305                            struct grep_expr *x,
306                            char *bol, char *eol,
307                            enum grep_context ctx,
308                            int collect_hits)
310         int h = 0;
312         switch (x->node) {
313         case GREP_NODE_ATOM:
314                 h = match_one_pattern(o, x->u.atom, bol, eol, ctx);
315                 break;
316         case GREP_NODE_NOT:
317                 h = !match_expr_eval(o, x->u.unary, bol, eol, ctx, 0);
318                 break;
319         case GREP_NODE_AND:
320                 if (!collect_hits)
321                         return (match_expr_eval(o, x->u.binary.left,
322                                                 bol, eol, ctx, 0) &&
323                                 match_expr_eval(o, x->u.binary.right,
324                                                 bol, eol, ctx, 0));
325                 h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0);
326                 h &= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 0);
327                 break;
328         case GREP_NODE_OR:
329                 if (!collect_hits)
330                         return (match_expr_eval(o, x->u.binary.left,
331                                                 bol, eol, ctx, 0) ||
332                                 match_expr_eval(o, x->u.binary.right,
333                                                 bol, eol, ctx, 0));
334                 h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0);
335                 x->u.binary.left->hit |= h;
336                 h |= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 1);
337                 break;
338         default:
339                 die("Unexpected node type (internal error) %d\n", x->node);
340         }
341         if (collect_hits)
342                 x->hit |= h;
343         return h;
346 static int match_expr(struct grep_opt *opt, char *bol, char *eol,
347                       enum grep_context ctx, int collect_hits)
349         struct grep_expr *x = opt->pattern_expression;
350         return match_expr_eval(opt, x, bol, eol, ctx, collect_hits);
353 static int match_line(struct grep_opt *opt, char *bol, char *eol,
354                       enum grep_context ctx, int collect_hits)
356         struct grep_pat *p;
357         if (opt->extended)
358                 return match_expr(opt, bol, eol, ctx, collect_hits);
360         /* we do not call with collect_hits without being extended */
361         for (p = opt->pattern_list; p; p = p->next) {
362                 if (match_one_pattern(opt, p, bol, eol, ctx))
363                         return 1;
364         }
365         return 0;
368 static int grep_buffer_1(struct grep_opt *opt, const char *name,
369                          char *buf, unsigned long size, int collect_hits)
371         char *bol = buf;
372         unsigned long left = size;
373         unsigned lno = 1;
374         struct pre_context_line {
375                 char *bol;
376                 char *eol;
377         } *prev = NULL, *pcl;
378         unsigned last_hit = 0;
379         unsigned last_shown = 0;
380         int binary_match_only = 0;
381         const char *hunk_mark = "";
382         unsigned count = 0;
383         enum grep_context ctx = GREP_CONTEXT_HEAD;
385         if (buffer_is_binary(buf, size)) {
386                 switch (opt->binary) {
387                 case GREP_BINARY_DEFAULT:
388                         binary_match_only = 1;
389                         break;
390                 case GREP_BINARY_NOMATCH:
391                         return 0; /* Assume unmatch */
392                         break;
393                 default:
394                         break;
395                 }
396         }
398         if (opt->pre_context)
399                 prev = xcalloc(opt->pre_context, sizeof(*prev));
400         if (opt->pre_context || opt->post_context)
401                 hunk_mark = "--\n";
403         while (left) {
404                 char *eol, ch;
405                 int hit;
407                 eol = end_of_line(bol, &left);
408                 ch = *eol;
409                 *eol = 0;
411                 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
412                         ctx = GREP_CONTEXT_BODY;
414                 hit = match_line(opt, bol, eol, ctx, collect_hits);
415                 *eol = ch;
417                 if (collect_hits)
418                         goto next_line;
420                 /* "grep -v -e foo -e bla" should list lines
421                  * that do not have either, so inversion should
422                  * be done outside.
423                  */
424                 if (opt->invert)
425                         hit = !hit;
426                 if (opt->unmatch_name_only) {
427                         if (hit)
428                                 return 0;
429                         goto next_line;
430                 }
431                 if (hit) {
432                         count++;
433                         if (opt->status_only)
434                                 return 1;
435                         if (binary_match_only) {
436                                 printf("Binary file %s matches\n", name);
437                                 return 1;
438                         }
439                         if (opt->name_only) {
440                                 printf("%s\n", name);
441                                 return 1;
442                         }
443                         /* Hit at this line.  If we haven't shown the
444                          * pre-context lines, we would need to show them.
445                          * When asked to do "count", this still show
446                          * the context which is nonsense, but the user
447                          * deserves to get that ;-).
448                          */
449                         if (opt->pre_context) {
450                                 unsigned from;
451                                 if (opt->pre_context < lno)
452                                         from = lno - opt->pre_context;
453                                 else
454                                         from = 1;
455                                 if (from <= last_shown)
456                                         from = last_shown + 1;
457                                 if (last_shown && from != last_shown + 1)
458                                         printf(hunk_mark);
459                                 while (from < lno) {
460                                         pcl = &prev[lno-from-1];
461                                         show_line(opt, pcl->bol, pcl->eol,
462                                                   name, from, '-');
463                                         from++;
464                                 }
465                                 last_shown = lno-1;
466                         }
467                         if (last_shown && lno != last_shown + 1)
468                                 printf(hunk_mark);
469                         if (!opt->count)
470                                 show_line(opt, bol, eol, name, lno, ':');
471                         last_shown = last_hit = lno;
472                 }
473                 else if (last_hit &&
474                          lno <= last_hit + opt->post_context) {
475                         /* If the last hit is within the post context,
476                          * we need to show this line.
477                          */
478                         if (last_shown && lno != last_shown + 1)
479                                 printf(hunk_mark);
480                         show_line(opt, bol, eol, name, lno, '-');
481                         last_shown = lno;
482                 }
483                 if (opt->pre_context) {
484                         memmove(prev+1, prev,
485                                 (opt->pre_context-1) * sizeof(*prev));
486                         prev->bol = bol;
487                         prev->eol = eol;
488                 }
490         next_line:
491                 bol = eol + 1;
492                 if (!left)
493                         break;
494                 left--;
495                 lno++;
496         }
498         free(prev);
499         if (collect_hits)
500                 return 0;
502         if (opt->status_only)
503                 return 0;
504         if (opt->unmatch_name_only) {
505                 /* We did not see any hit, so we want to show this */
506                 printf("%s\n", name);
507                 return 1;
508         }
510         /* NEEDSWORK:
511          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
512          * which feels mostly useless but sometimes useful.  Maybe
513          * make it another option?  For now suppress them.
514          */
515         if (opt->count && count)
516                 printf("%s:%u\n", name, count);
517         return !!last_hit;
520 static void clr_hit_marker(struct grep_expr *x)
522         /* All-hit markers are meaningful only at the very top level
523          * OR node.
524          */
525         while (1) {
526                 x->hit = 0;
527                 if (x->node != GREP_NODE_OR)
528                         return;
529                 x->u.binary.left->hit = 0;
530                 x = x->u.binary.right;
531         }
534 static int chk_hit_marker(struct grep_expr *x)
536         /* Top level nodes have hit markers.  See if they all are hits */
537         while (1) {
538                 if (x->node != GREP_NODE_OR)
539                         return x->hit;
540                 if (!x->u.binary.left->hit)
541                         return 0;
542                 x = x->u.binary.right;
543         }
546 int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
548         /*
549          * we do not have to do the two-pass grep when we do not check
550          * buffer-wide "all-match".
551          */
552         if (!opt->all_match)
553                 return grep_buffer_1(opt, name, buf, size, 0);
555         /* Otherwise the toplevel "or" terms hit a bit differently.
556          * We first clear hit markers from them.
557          */
558         clr_hit_marker(opt->pattern_expression);
559         grep_buffer_1(opt, name, buf, size, 1);
561         if (!chk_hit_marker(opt->pattern_expression))
562                 return 0;
564         return grep_buffer_1(opt, name, buf, size, 0);