Merge branch 'maint'
[debian-git.git] / grep.c
blobf3a27d7d6e141bd8813b978edbe33d16aa764fb4
1 #include "cache.h"
2 #include "grep.h"
3 #include "xdiff-interface.h"
5 void append_header_grep_pattern(struct grep_opt *opt, enum grep_header_field field, const char *pat)
7 struct grep_pat *p = xcalloc(1, sizeof(*p));
8 p->pattern = pat;
9 p->origin = "header";
10 p->no = 0;
11 p->token = GREP_PATTERN_HEAD;
12 p->field = field;
13 *opt->pattern_tail = p;
14 opt->pattern_tail = &p->next;
15 p->next = NULL;
18 void append_grep_pattern(struct grep_opt *opt, const char *pat,
19 const char *origin, int no, enum grep_pat_token t)
21 struct grep_pat *p = xcalloc(1, sizeof(*p));
22 p->pattern = pat;
23 p->origin = origin;
24 p->no = no;
25 p->token = t;
26 *opt->pattern_tail = p;
27 opt->pattern_tail = &p->next;
28 p->next = NULL;
31 static int is_fixed(const char *s)
33 while (*s && !is_regex_special(*s))
34 s++;
35 return !*s;
38 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
40 int err;
42 p->word_regexp = opt->word_regexp;
44 if (opt->fixed || is_fixed(p->pattern))
45 p->fixed = 1;
46 if (opt->regflags & REG_ICASE)
47 p->fixed = 0;
48 if (p->fixed)
49 return;
51 err = regcomp(&p->regexp, p->pattern, opt->regflags);
52 if (err) {
53 char errbuf[1024];
54 char where[1024];
55 if (p->no)
56 sprintf(where, "In '%s' at %d, ",
57 p->origin, p->no);
58 else if (p->origin)
59 sprintf(where, "%s, ", p->origin);
60 else
61 where[0] = 0;
62 regerror(err, &p->regexp, errbuf, 1024);
63 regfree(&p->regexp);
64 die("%s'%s': %s", where, p->pattern, errbuf);
68 static struct grep_expr *compile_pattern_or(struct grep_pat **);
69 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
71 struct grep_pat *p;
72 struct grep_expr *x;
74 p = *list;
75 switch (p->token) {
76 case GREP_PATTERN: /* atom */
77 case GREP_PATTERN_HEAD:
78 case GREP_PATTERN_BODY:
79 x = xcalloc(1, sizeof (struct grep_expr));
80 x->node = GREP_NODE_ATOM;
81 x->u.atom = p;
82 *list = p->next;
83 return x;
84 case GREP_OPEN_PAREN:
85 *list = p->next;
86 x = compile_pattern_or(list);
87 if (!x)
88 return NULL;
89 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
90 die("unmatched parenthesis");
91 *list = (*list)->next;
92 return x;
93 default:
94 return NULL;
98 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
100 struct grep_pat *p;
101 struct grep_expr *x;
103 p = *list;
104 switch (p->token) {
105 case GREP_NOT:
106 if (!p->next)
107 die("--not not followed by pattern expression");
108 *list = p->next;
109 x = xcalloc(1, sizeof (struct grep_expr));
110 x->node = GREP_NODE_NOT;
111 x->u.unary = compile_pattern_not(list);
112 if (!x->u.unary)
113 die("--not followed by non pattern expression");
114 return x;
115 default:
116 return compile_pattern_atom(list);
120 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
122 struct grep_pat *p;
123 struct grep_expr *x, *y, *z;
125 x = compile_pattern_not(list);
126 p = *list;
127 if (p && p->token == GREP_AND) {
128 if (!p->next)
129 die("--and not followed by pattern expression");
130 *list = p->next;
131 y = compile_pattern_and(list);
132 if (!y)
133 die("--and not followed by pattern expression");
134 z = xcalloc(1, sizeof (struct grep_expr));
135 z->node = GREP_NODE_AND;
136 z->u.binary.left = x;
137 z->u.binary.right = y;
138 return z;
140 return x;
143 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
145 struct grep_pat *p;
146 struct grep_expr *x, *y, *z;
148 x = compile_pattern_and(list);
149 p = *list;
150 if (x && p && p->token != GREP_CLOSE_PAREN) {
151 y = compile_pattern_or(list);
152 if (!y)
153 die("not a pattern expression %s", p->pattern);
154 z = xcalloc(1, sizeof (struct grep_expr));
155 z->node = GREP_NODE_OR;
156 z->u.binary.left = x;
157 z->u.binary.right = y;
158 return z;
160 return x;
163 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
165 return compile_pattern_or(list);
168 void compile_grep_patterns(struct grep_opt *opt)
170 struct grep_pat *p;
172 if (opt->all_match)
173 opt->extended = 1;
175 for (p = opt->pattern_list; p; p = p->next) {
176 switch (p->token) {
177 case GREP_PATTERN: /* atom */
178 case GREP_PATTERN_HEAD:
179 case GREP_PATTERN_BODY:
180 compile_regexp(p, opt);
181 break;
182 default:
183 opt->extended = 1;
184 break;
188 if (!opt->extended)
189 return;
191 /* Then bundle them up in an expression.
192 * A classic recursive descent parser would do.
194 p = opt->pattern_list;
195 if (p)
196 opt->pattern_expression = compile_pattern_expr(&p);
197 if (p)
198 die("incomplete pattern expression: %s", p->pattern);
201 static void free_pattern_expr(struct grep_expr *x)
203 switch (x->node) {
204 case GREP_NODE_ATOM:
205 break;
206 case GREP_NODE_NOT:
207 free_pattern_expr(x->u.unary);
208 break;
209 case GREP_NODE_AND:
210 case GREP_NODE_OR:
211 free_pattern_expr(x->u.binary.left);
212 free_pattern_expr(x->u.binary.right);
213 break;
215 free(x);
218 void free_grep_patterns(struct grep_opt *opt)
220 struct grep_pat *p, *n;
222 for (p = opt->pattern_list; p; p = n) {
223 n = p->next;
224 switch (p->token) {
225 case GREP_PATTERN: /* atom */
226 case GREP_PATTERN_HEAD:
227 case GREP_PATTERN_BODY:
228 regfree(&p->regexp);
229 break;
230 default:
231 break;
233 free(p);
236 if (!opt->extended)
237 return;
238 free_pattern_expr(opt->pattern_expression);
241 static char *end_of_line(char *cp, unsigned long *left)
243 unsigned long l = *left;
244 while (l && *cp != '\n') {
245 l--;
246 cp++;
248 *left = l;
249 return cp;
252 static int word_char(char ch)
254 return isalnum(ch) || ch == '_';
257 static void show_name(struct grep_opt *opt, const char *name)
259 printf("%s%c", name, opt->null_following_name ? '\0' : '\n');
262 static int fixmatch(const char *pattern, char *line, regmatch_t *match)
264 char *hit = strstr(line, pattern);
265 if (!hit) {
266 match->rm_so = match->rm_eo = -1;
267 return REG_NOMATCH;
269 else {
270 match->rm_so = hit - line;
271 match->rm_eo = match->rm_so + strlen(pattern);
272 return 0;
276 static int strip_timestamp(char *bol, char **eol_p)
278 char *eol = *eol_p;
279 int ch;
281 while (bol < --eol) {
282 if (*eol != '>')
283 continue;
284 *eol_p = ++eol;
285 ch = *eol;
286 *eol = '\0';
287 return ch;
289 return 0;
292 static struct {
293 const char *field;
294 size_t len;
295 } header_field[] = {
296 { "author ", 7 },
297 { "committer ", 10 },
300 static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
301 enum grep_context ctx,
302 regmatch_t *pmatch, int eflags)
304 int hit = 0;
305 int saved_ch = 0;
307 if ((p->token != GREP_PATTERN) &&
308 ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
309 return 0;
311 if (p->token == GREP_PATTERN_HEAD) {
312 const char *field;
313 size_t len;
314 assert(p->field < ARRAY_SIZE(header_field));
315 field = header_field[p->field].field;
316 len = header_field[p->field].len;
317 if (strncmp(bol, field, len))
318 return 0;
319 bol += len;
320 saved_ch = strip_timestamp(bol, &eol);
323 again:
324 if (p->fixed)
325 hit = !fixmatch(p->pattern, bol, pmatch);
326 else
327 hit = !regexec(&p->regexp, bol, 1, pmatch, eflags);
329 if (hit && p->word_regexp) {
330 if ((pmatch[0].rm_so < 0) ||
331 (eol - bol) <= pmatch[0].rm_so ||
332 (pmatch[0].rm_eo < 0) ||
333 (eol - bol) < pmatch[0].rm_eo)
334 die("regexp returned nonsense");
336 /* Match beginning must be either beginning of the
337 * line, or at word boundary (i.e. the last char must
338 * not be a word char). Similarly, match end must be
339 * either end of the line, or at word boundary
340 * (i.e. the next char must not be a word char).
342 if ( ((pmatch[0].rm_so == 0) ||
343 !word_char(bol[pmatch[0].rm_so-1])) &&
344 ((pmatch[0].rm_eo == (eol-bol)) ||
345 !word_char(bol[pmatch[0].rm_eo])) )
347 else
348 hit = 0;
350 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
351 /* There could be more than one match on the
352 * line, and the first match might not be
353 * strict word match. But later ones could be!
354 * Forward to the next possible start, i.e. the
355 * next position following a non-word char.
357 bol = pmatch[0].rm_so + bol + 1;
358 while (word_char(bol[-1]) && bol < eol)
359 bol++;
360 if (bol < eol)
361 goto again;
364 if (p->token == GREP_PATTERN_HEAD && saved_ch)
365 *eol = saved_ch;
366 return hit;
369 static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
370 enum grep_context ctx, int collect_hits)
372 int h = 0;
373 regmatch_t match;
375 switch (x->node) {
376 case GREP_NODE_ATOM:
377 h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
378 break;
379 case GREP_NODE_NOT:
380 h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
381 break;
382 case GREP_NODE_AND:
383 if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
384 return 0;
385 h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
386 break;
387 case GREP_NODE_OR:
388 if (!collect_hits)
389 return (match_expr_eval(x->u.binary.left,
390 bol, eol, ctx, 0) ||
391 match_expr_eval(x->u.binary.right,
392 bol, eol, ctx, 0));
393 h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
394 x->u.binary.left->hit |= h;
395 h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
396 break;
397 default:
398 die("Unexpected node type (internal error) %d", x->node);
400 if (collect_hits)
401 x->hit |= h;
402 return h;
405 static int match_expr(struct grep_opt *opt, char *bol, char *eol,
406 enum grep_context ctx, int collect_hits)
408 struct grep_expr *x = opt->pattern_expression;
409 return match_expr_eval(x, bol, eol, ctx, collect_hits);
412 static int match_line(struct grep_opt *opt, char *bol, char *eol,
413 enum grep_context ctx, int collect_hits)
415 struct grep_pat *p;
416 regmatch_t match;
418 if (opt->extended)
419 return match_expr(opt, bol, eol, ctx, collect_hits);
421 /* we do not call with collect_hits without being extended */
422 for (p = opt->pattern_list; p; p = p->next) {
423 if (match_one_pattern(p, bol, eol, ctx, &match, 0))
424 return 1;
426 return 0;
429 static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
430 enum grep_context ctx,
431 regmatch_t *pmatch, int eflags)
433 regmatch_t match;
435 if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
436 return 0;
437 if (match.rm_so < 0 || match.rm_eo < 0)
438 return 0;
439 if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
440 if (match.rm_so > pmatch->rm_so)
441 return 1;
442 if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
443 return 1;
445 pmatch->rm_so = match.rm_so;
446 pmatch->rm_eo = match.rm_eo;
447 return 1;
450 static int next_match(struct grep_opt *opt, char *bol, char *eol,
451 enum grep_context ctx, regmatch_t *pmatch, int eflags)
453 struct grep_pat *p;
454 int hit = 0;
456 pmatch->rm_so = pmatch->rm_eo = -1;
457 if (bol < eol) {
458 for (p = opt->pattern_list; p; p = p->next) {
459 switch (p->token) {
460 case GREP_PATTERN: /* atom */
461 case GREP_PATTERN_HEAD:
462 case GREP_PATTERN_BODY:
463 hit |= match_next_pattern(p, bol, eol, ctx,
464 pmatch, eflags);
465 break;
466 default:
467 break;
471 return hit;
474 static void show_line(struct grep_opt *opt, char *bol, char *eol,
475 const char *name, unsigned lno, char sign)
477 int rest = eol - bol;
479 if (opt->null_following_name)
480 sign = '\0';
481 if (opt->pathname)
482 printf("%s%c", name, sign);
483 if (opt->linenum)
484 printf("%d%c", lno, sign);
485 if (opt->color) {
486 regmatch_t match;
487 enum grep_context ctx = GREP_CONTEXT_BODY;
488 int ch = *eol;
489 int eflags = 0;
491 *eol = '\0';
492 while (next_match(opt, bol, eol, ctx, &match, eflags)) {
493 printf("%.*s%s%.*s%s",
494 (int)match.rm_so, bol,
495 opt->color_match,
496 (int)(match.rm_eo - match.rm_so), bol + match.rm_so,
497 GIT_COLOR_RESET);
498 bol += match.rm_eo;
499 rest -= match.rm_eo;
500 eflags = REG_NOTBOL;
502 *eol = ch;
504 printf("%.*s\n", rest, bol);
507 static int grep_buffer_1(struct grep_opt *opt, const char *name,
508 char *buf, unsigned long size, int collect_hits)
510 char *bol = buf;
511 unsigned long left = size;
512 unsigned lno = 1;
513 struct pre_context_line {
514 char *bol;
515 char *eol;
516 } *prev = NULL, *pcl;
517 unsigned last_hit = 0;
518 unsigned last_shown = 0;
519 int binary_match_only = 0;
520 const char *hunk_mark = "";
521 unsigned count = 0;
522 enum grep_context ctx = GREP_CONTEXT_HEAD;
524 if (buffer_is_binary(buf, size)) {
525 switch (opt->binary) {
526 case GREP_BINARY_DEFAULT:
527 binary_match_only = 1;
528 break;
529 case GREP_BINARY_NOMATCH:
530 return 0; /* Assume unmatch */
531 break;
532 default:
533 break;
537 if (opt->pre_context)
538 prev = xcalloc(opt->pre_context, sizeof(*prev));
539 if (opt->pre_context || opt->post_context)
540 hunk_mark = "--\n";
542 while (left) {
543 char *eol, ch;
544 int hit;
546 eol = end_of_line(bol, &left);
547 ch = *eol;
548 *eol = 0;
550 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
551 ctx = GREP_CONTEXT_BODY;
553 hit = match_line(opt, bol, eol, ctx, collect_hits);
554 *eol = ch;
556 if (collect_hits)
557 goto next_line;
559 /* "grep -v -e foo -e bla" should list lines
560 * that do not have either, so inversion should
561 * be done outside.
563 if (opt->invert)
564 hit = !hit;
565 if (opt->unmatch_name_only) {
566 if (hit)
567 return 0;
568 goto next_line;
570 if (hit) {
571 count++;
572 if (opt->status_only)
573 return 1;
574 if (binary_match_only) {
575 printf("Binary file %s matches\n", name);
576 return 1;
578 if (opt->name_only) {
579 show_name(opt, name);
580 return 1;
582 /* Hit at this line. If we haven't shown the
583 * pre-context lines, we would need to show them.
584 * When asked to do "count", this still show
585 * the context which is nonsense, but the user
586 * deserves to get that ;-).
588 if (opt->pre_context) {
589 unsigned from;
590 if (opt->pre_context < lno)
591 from = lno - opt->pre_context;
592 else
593 from = 1;
594 if (from <= last_shown)
595 from = last_shown + 1;
596 if (last_shown && from != last_shown + 1)
597 fputs(hunk_mark, stdout);
598 while (from < lno) {
599 pcl = &prev[lno-from-1];
600 show_line(opt, pcl->bol, pcl->eol,
601 name, from, '-');
602 from++;
604 last_shown = lno-1;
606 if (last_shown && lno != last_shown + 1)
607 fputs(hunk_mark, stdout);
608 if (!opt->count)
609 show_line(opt, bol, eol, name, lno, ':');
610 last_shown = last_hit = lno;
612 else if (last_hit &&
613 lno <= last_hit + opt->post_context) {
614 /* If the last hit is within the post context,
615 * we need to show this line.
617 if (last_shown && lno != last_shown + 1)
618 fputs(hunk_mark, stdout);
619 show_line(opt, bol, eol, name, lno, '-');
620 last_shown = lno;
622 if (opt->pre_context) {
623 memmove(prev+1, prev,
624 (opt->pre_context-1) * sizeof(*prev));
625 prev->bol = bol;
626 prev->eol = eol;
629 next_line:
630 bol = eol + 1;
631 if (!left)
632 break;
633 left--;
634 lno++;
637 free(prev);
638 if (collect_hits)
639 return 0;
641 if (opt->status_only)
642 return 0;
643 if (opt->unmatch_name_only) {
644 /* We did not see any hit, so we want to show this */
645 show_name(opt, name);
646 return 1;
649 /* NEEDSWORK:
650 * The real "grep -c foo *.c" gives many "bar.c:0" lines,
651 * which feels mostly useless but sometimes useful. Maybe
652 * make it another option? For now suppress them.
654 if (opt->count && count)
655 printf("%s%c%u\n", name,
656 opt->null_following_name ? '\0' : ':', count);
657 return !!last_hit;
660 static void clr_hit_marker(struct grep_expr *x)
662 /* All-hit markers are meaningful only at the very top level
663 * OR node.
665 while (1) {
666 x->hit = 0;
667 if (x->node != GREP_NODE_OR)
668 return;
669 x->u.binary.left->hit = 0;
670 x = x->u.binary.right;
674 static int chk_hit_marker(struct grep_expr *x)
676 /* Top level nodes have hit markers. See if they all are hits */
677 while (1) {
678 if (x->node != GREP_NODE_OR)
679 return x->hit;
680 if (!x->u.binary.left->hit)
681 return 0;
682 x = x->u.binary.right;
686 int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
689 * we do not have to do the two-pass grep when we do not check
690 * buffer-wide "all-match".
692 if (!opt->all_match)
693 return grep_buffer_1(opt, name, buf, size, 0);
695 /* Otherwise the toplevel "or" terms hit a bit differently.
696 * We first clear hit markers from them.
698 clr_hit_marker(opt->pattern_expression);
699 grep_buffer_1(opt, name, buf, size, 1);
701 if (!chk_hit_marker(opt->pattern_expression))
702 return 0;
704 return grep_buffer_1(opt, name, buf, size, 0);