Documentation: fix a grammatical error in api-builtin.txt
[git/git.git] / grep.c
CommitLineData
83b5d2f5 1#include "cache.h"
83b5d2f5 2#include "grep.h"
6bfce93e 3#include "xdiff-interface.h"
83b5d2f5 4
a4d7d2c6
JH
5void append_header_grep_pattern(struct grep_opt *opt, enum grep_header_field field, const char *pat)
6{
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;
16}
17
83b5d2f5
JH
18void append_grep_pattern(struct grep_opt *opt, const char *pat,
19 const char *origin, int no, enum grep_pat_token t)
20{
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;
29}
30
31static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
32{
33 int err = regcomp(&p->regexp, p->pattern, opt->regflags);
34 if (err) {
35 char errbuf[1024];
36 char where[1024];
37 if (p->no)
38 sprintf(where, "In '%s' at %d, ",
39 p->origin, p->no);
40 else if (p->origin)
41 sprintf(where, "%s, ", p->origin);
42 else
43 where[0] = 0;
44 regerror(err, &p->regexp, errbuf, 1024);
45 regfree(&p->regexp);
46 die("%s'%s': %s", where, p->pattern, errbuf);
47 }
48}
49
0ab7befa 50static struct grep_expr *compile_pattern_or(struct grep_pat **);
83b5d2f5
JH
51static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
52{
53 struct grep_pat *p;
54 struct grep_expr *x;
55
56 p = *list;
57 switch (p->token) {
58 case GREP_PATTERN: /* atom */
480c1ca6
JH
59 case GREP_PATTERN_HEAD:
60 case GREP_PATTERN_BODY:
83b5d2f5
JH
61 x = xcalloc(1, sizeof (struct grep_expr));
62 x->node = GREP_NODE_ATOM;
63 x->u.atom = p;
64 *list = p->next;
65 return x;
66 case GREP_OPEN_PAREN:
67 *list = p->next;
0ab7befa 68 x = compile_pattern_or(list);
83b5d2f5
JH
69 if (!x)
70 return NULL;
71 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
72 die("unmatched parenthesis");
73 *list = (*list)->next;
74 return x;
75 default:
76 return NULL;
77 }
78}
79
80static struct grep_expr *compile_pattern_not(struct grep_pat **list)
81{
82 struct grep_pat *p;
83 struct grep_expr *x;
84
85 p = *list;
86 switch (p->token) {
87 case GREP_NOT:
88 if (!p->next)
89 die("--not not followed by pattern expression");
90 *list = p->next;
91 x = xcalloc(1, sizeof (struct grep_expr));
92 x->node = GREP_NODE_NOT;
93 x->u.unary = compile_pattern_not(list);
94 if (!x->u.unary)
95 die("--not followed by non pattern expression");
96 return x;
97 default:
98 return compile_pattern_atom(list);
99 }
100}
101
102static struct grep_expr *compile_pattern_and(struct grep_pat **list)
103{
104 struct grep_pat *p;
105 struct grep_expr *x, *y, *z;
106
107 x = compile_pattern_not(list);
108 p = *list;
109 if (p && p->token == GREP_AND) {
110 if (!p->next)
111 die("--and not followed by pattern expression");
112 *list = p->next;
113 y = compile_pattern_and(list);
114 if (!y)
115 die("--and not followed by pattern expression");
116 z = xcalloc(1, sizeof (struct grep_expr));
117 z->node = GREP_NODE_AND;
118 z->u.binary.left = x;
119 z->u.binary.right = y;
120 return z;
121 }
122 return x;
123}
124
125static struct grep_expr *compile_pattern_or(struct grep_pat **list)
126{
127 struct grep_pat *p;
128 struct grep_expr *x, *y, *z;
129
130 x = compile_pattern_and(list);
131 p = *list;
132 if (x && p && p->token != GREP_CLOSE_PAREN) {
133 y = compile_pattern_or(list);
134 if (!y)
135 die("not a pattern expression %s", p->pattern);
136 z = xcalloc(1, sizeof (struct grep_expr));
137 z->node = GREP_NODE_OR;
138 z->u.binary.left = x;
139 z->u.binary.right = y;
140 return z;
141 }
142 return x;
143}
144
145static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
146{
147 return compile_pattern_or(list);
148}
149
150void compile_grep_patterns(struct grep_opt *opt)
151{
152 struct grep_pat *p;
153
0ab7befa
JH
154 if (opt->all_match)
155 opt->extended = 1;
156
83b5d2f5 157 for (p = opt->pattern_list; p; p = p->next) {
480c1ca6
JH
158 switch (p->token) {
159 case GREP_PATTERN: /* atom */
160 case GREP_PATTERN_HEAD:
161 case GREP_PATTERN_BODY:
a3f5d02e
JH
162 if (!opt->fixed)
163 compile_regexp(p, opt);
480c1ca6
JH
164 break;
165 default:
83b5d2f5 166 opt->extended = 1;
480c1ca6
JH
167 break;
168 }
83b5d2f5
JH
169 }
170
171 if (!opt->extended)
172 return;
173
174 /* Then bundle them up in an expression.
175 * A classic recursive descent parser would do.
176 */
177 p = opt->pattern_list;
178 opt->pattern_expression = compile_pattern_expr(&p);
179 if (p)
180 die("incomplete pattern expression: %s", p->pattern);
181}
182
b48fb5b6
JH
183static void free_pattern_expr(struct grep_expr *x)
184{
185 switch (x->node) {
186 case GREP_NODE_ATOM:
187 break;
188 case GREP_NODE_NOT:
189 free_pattern_expr(x->u.unary);
190 break;
191 case GREP_NODE_AND:
192 case GREP_NODE_OR:
193 free_pattern_expr(x->u.binary.left);
194 free_pattern_expr(x->u.binary.right);
195 break;
196 }
197 free(x);
198}
199
200void free_grep_patterns(struct grep_opt *opt)
201{
202 struct grep_pat *p, *n;
203
204 for (p = opt->pattern_list; p; p = n) {
205 n = p->next;
206 switch (p->token) {
207 case GREP_PATTERN: /* atom */
208 case GREP_PATTERN_HEAD:
209 case GREP_PATTERN_BODY:
210 regfree(&p->regexp);
211 break;
212 default:
213 break;
214 }
215 free(p);
216 }
217
218 if (!opt->extended)
219 return;
220 free_pattern_expr(opt->pattern_expression);
221}
222
83b5d2f5
JH
223static char *end_of_line(char *cp, unsigned long *left)
224{
225 unsigned long l = *left;
226 while (l && *cp != '\n') {
227 l--;
228 cp++;
229 }
230 *left = l;
231 return cp;
232}
233
234static int word_char(char ch)
235{
236 return isalnum(ch) || ch == '_';
237}
238
239static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
240 const char *name, unsigned lno, char sign)
241{
242 if (opt->pathname)
243 printf("%s%c", name, sign);
244 if (opt->linenum)
245 printf("%d%c", lno, sign);
246 printf("%.*s\n", (int)(eol-bol), bol);
247}
248
83b5d2f5
JH
249static int fixmatch(const char *pattern, char *line, regmatch_t *match)
250{
251 char *hit = strstr(line, pattern);
252 if (!hit) {
253 match->rm_so = match->rm_eo = -1;
254 return REG_NOMATCH;
255 }
256 else {
257 match->rm_so = hit - line;
258 match->rm_eo = match->rm_so + strlen(pattern);
259 return 0;
260 }
261}
262
a4d7d2c6
JH
263static int strip_timestamp(char *bol, char **eol_p)
264{
265 char *eol = *eol_p;
266 int ch;
267
268 while (bol < --eol) {
269 if (*eol != '>')
270 continue;
271 *eol_p = ++eol;
272 ch = *eol;
273 *eol = '\0';
274 return ch;
275 }
276 return 0;
277}
278
279static struct {
280 const char *field;
281 size_t len;
282} header_field[] = {
283 { "author ", 7 },
284 { "committer ", 10 },
285};
286
480c1ca6 287static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol, enum grep_context ctx)
83b5d2f5
JH
288{
289 int hit = 0;
290 int at_true_bol = 1;
a4d7d2c6 291 int saved_ch = 0;
83b5d2f5
JH
292 regmatch_t pmatch[10];
293
480c1ca6
JH
294 if ((p->token != GREP_PATTERN) &&
295 ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
296 return 0;
297
a4d7d2c6
JH
298 if (p->token == GREP_PATTERN_HEAD) {
299 const char *field;
300 size_t len;
301 assert(p->field < ARRAY_SIZE(header_field));
302 field = header_field[p->field].field;
303 len = header_field[p->field].len;
304 if (strncmp(bol, field, len))
305 return 0;
306 bol += len;
307 saved_ch = strip_timestamp(bol, &eol);
308 }
309
83b5d2f5
JH
310 again:
311 if (!opt->fixed) {
312 regex_t *exp = &p->regexp;
313 hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
314 pmatch, 0);
315 }
316 else {
317 hit = !fixmatch(p->pattern, bol, pmatch);
318 }
319
320 if (hit && opt->word_regexp) {
321 if ((pmatch[0].rm_so < 0) ||
322 (eol - bol) <= pmatch[0].rm_so ||
323 (pmatch[0].rm_eo < 0) ||
324 (eol - bol) < pmatch[0].rm_eo)
325 die("regexp returned nonsense");
326
327 /* Match beginning must be either beginning of the
328 * line, or at word boundary (i.e. the last char must
329 * not be a word char). Similarly, match end must be
330 * either end of the line, or at word boundary
331 * (i.e. the next char must not be a word char).
332 */
333 if ( ((pmatch[0].rm_so == 0 && at_true_bol) ||
334 !word_char(bol[pmatch[0].rm_so-1])) &&
335 ((pmatch[0].rm_eo == (eol-bol)) ||
336 !word_char(bol[pmatch[0].rm_eo])) )
337 ;
338 else
339 hit = 0;
340
341 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
342 /* There could be more than one match on the
343 * line, and the first match might not be
344 * strict word match. But later ones could be!
345 */
346 bol = pmatch[0].rm_so + bol + 1;
347 at_true_bol = 0;
348 goto again;
349 }
350 }
a4d7d2c6
JH
351 if (p->token == GREP_PATTERN_HEAD && saved_ch)
352 *eol = saved_ch;
83b5d2f5
JH
353 return hit;
354}
355
0ab7befa 356static int match_expr_eval(struct grep_opt *o,
83b5d2f5 357 struct grep_expr *x,
480c1ca6 358 char *bol, char *eol,
0ab7befa
JH
359 enum grep_context ctx,
360 int collect_hits)
83b5d2f5 361{
0ab7befa
JH
362 int h = 0;
363
83b5d2f5
JH
364 switch (x->node) {
365 case GREP_NODE_ATOM:
0ab7befa 366 h = match_one_pattern(o, x->u.atom, bol, eol, ctx);
83b5d2f5
JH
367 break;
368 case GREP_NODE_NOT:
0ab7befa
JH
369 h = !match_expr_eval(o, x->u.unary, bol, eol, ctx, 0);
370 break;
83b5d2f5 371 case GREP_NODE_AND:
0ab7befa
JH
372 if (!collect_hits)
373 return (match_expr_eval(o, x->u.binary.left,
374 bol, eol, ctx, 0) &&
375 match_expr_eval(o, x->u.binary.right,
376 bol, eol, ctx, 0));
377 h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0);
378 h &= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 0);
379 break;
83b5d2f5 380 case GREP_NODE_OR:
0ab7befa
JH
381 if (!collect_hits)
382 return (match_expr_eval(o, x->u.binary.left,
383 bol, eol, ctx, 0) ||
384 match_expr_eval(o, x->u.binary.right,
385 bol, eol, ctx, 0));
386 h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0);
387 x->u.binary.left->hit |= h;
388 h |= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 1);
389 break;
390 default:
391 die("Unexpected node type (internal error) %d\n", x->node);
83b5d2f5 392 }
0ab7befa
JH
393 if (collect_hits)
394 x->hit |= h;
395 return h;
83b5d2f5
JH
396}
397
480c1ca6 398static int match_expr(struct grep_opt *opt, char *bol, char *eol,
0ab7befa 399 enum grep_context ctx, int collect_hits)
83b5d2f5
JH
400{
401 struct grep_expr *x = opt->pattern_expression;
0ab7befa 402 return match_expr_eval(opt, x, bol, eol, ctx, collect_hits);
83b5d2f5
JH
403}
404
480c1ca6 405static int match_line(struct grep_opt *opt, char *bol, char *eol,
0ab7befa 406 enum grep_context ctx, int collect_hits)
83b5d2f5
JH
407{
408 struct grep_pat *p;
409 if (opt->extended)
0ab7befa
JH
410 return match_expr(opt, bol, eol, ctx, collect_hits);
411
412 /* we do not call with collect_hits without being extended */
83b5d2f5 413 for (p = opt->pattern_list; p; p = p->next) {
480c1ca6 414 if (match_one_pattern(opt, p, bol, eol, ctx))
83b5d2f5
JH
415 return 1;
416 }
417 return 0;
418}
419
0ab7befa
JH
420static int grep_buffer_1(struct grep_opt *opt, const char *name,
421 char *buf, unsigned long size, int collect_hits)
83b5d2f5
JH
422{
423 char *bol = buf;
424 unsigned long left = size;
425 unsigned lno = 1;
426 struct pre_context_line {
427 char *bol;
428 char *eol;
429 } *prev = NULL, *pcl;
430 unsigned last_hit = 0;
431 unsigned last_shown = 0;
432 int binary_match_only = 0;
433 const char *hunk_mark = "";
434 unsigned count = 0;
480c1ca6 435 enum grep_context ctx = GREP_CONTEXT_HEAD;
83b5d2f5
JH
436
437 if (buffer_is_binary(buf, size)) {
438 switch (opt->binary) {
439 case GREP_BINARY_DEFAULT:
440 binary_match_only = 1;
441 break;
442 case GREP_BINARY_NOMATCH:
443 return 0; /* Assume unmatch */
444 break;
445 default:
446 break;
447 }
448 }
449
450 if (opt->pre_context)
451 prev = xcalloc(opt->pre_context, sizeof(*prev));
452 if (opt->pre_context || opt->post_context)
453 hunk_mark = "--\n";
454
455 while (left) {
456 char *eol, ch;
0ab7befa 457 int hit;
83b5d2f5
JH
458
459 eol = end_of_line(bol, &left);
460 ch = *eol;
461 *eol = 0;
462
480c1ca6
JH
463 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
464 ctx = GREP_CONTEXT_BODY;
465
0ab7befa 466 hit = match_line(opt, bol, eol, ctx, collect_hits);
83b5d2f5
JH
467 *eol = ch;
468
0ab7befa
JH
469 if (collect_hits)
470 goto next_line;
471
83b5d2f5
JH
472 /* "grep -v -e foo -e bla" should list lines
473 * that do not have either, so inversion should
474 * be done outside.
475 */
476 if (opt->invert)
477 hit = !hit;
478 if (opt->unmatch_name_only) {
479 if (hit)
480 return 0;
481 goto next_line;
482 }
483 if (hit) {
484 count++;
485 if (opt->status_only)
486 return 1;
487 if (binary_match_only) {
488 printf("Binary file %s matches\n", name);
489 return 1;
490 }
491 if (opt->name_only) {
492 printf("%s\n", name);
493 return 1;
494 }
495 /* Hit at this line. If we haven't shown the
496 * pre-context lines, we would need to show them.
497 * When asked to do "count", this still show
498 * the context which is nonsense, but the user
499 * deserves to get that ;-).
500 */
501 if (opt->pre_context) {
502 unsigned from;
503 if (opt->pre_context < lno)
504 from = lno - opt->pre_context;
505 else
506 from = 1;
507 if (from <= last_shown)
508 from = last_shown + 1;
509 if (last_shown && from != last_shown + 1)
9db56f71 510 fputs(hunk_mark, stdout);
83b5d2f5
JH
511 while (from < lno) {
512 pcl = &prev[lno-from-1];
513 show_line(opt, pcl->bol, pcl->eol,
514 name, from, '-');
515 from++;
516 }
517 last_shown = lno-1;
518 }
519 if (last_shown && lno != last_shown + 1)
9db56f71 520 fputs(hunk_mark, stdout);
83b5d2f5
JH
521 if (!opt->count)
522 show_line(opt, bol, eol, name, lno, ':');
523 last_shown = last_hit = lno;
524 }
525 else if (last_hit &&
526 lno <= last_hit + opt->post_context) {
527 /* If the last hit is within the post context,
528 * we need to show this line.
529 */
530 if (last_shown && lno != last_shown + 1)
9db56f71 531 fputs(hunk_mark, stdout);
83b5d2f5
JH
532 show_line(opt, bol, eol, name, lno, '-');
533 last_shown = lno;
534 }
535 if (opt->pre_context) {
536 memmove(prev+1, prev,
537 (opt->pre_context-1) * sizeof(*prev));
538 prev->bol = bol;
539 prev->eol = eol;
540 }
541
542 next_line:
543 bol = eol + 1;
544 if (!left)
545 break;
546 left--;
547 lno++;
548 }
549
b48fb5b6 550 free(prev);
0ab7befa
JH
551 if (collect_hits)
552 return 0;
b48fb5b6 553
83b5d2f5
JH
554 if (opt->status_only)
555 return 0;
556 if (opt->unmatch_name_only) {
557 /* We did not see any hit, so we want to show this */
558 printf("%s\n", name);
559 return 1;
560 }
561
562 /* NEEDSWORK:
563 * The real "grep -c foo *.c" gives many "bar.c:0" lines,
564 * which feels mostly useless but sometimes useful. Maybe
565 * make it another option? For now suppress them.
566 */
567 if (opt->count && count)
568 printf("%s:%u\n", name, count);
569 return !!last_hit;
570}
571
0ab7befa
JH
572static void clr_hit_marker(struct grep_expr *x)
573{
574 /* All-hit markers are meaningful only at the very top level
575 * OR node.
576 */
577 while (1) {
578 x->hit = 0;
579 if (x->node != GREP_NODE_OR)
580 return;
581 x->u.binary.left->hit = 0;
582 x = x->u.binary.right;
583 }
584}
585
586static int chk_hit_marker(struct grep_expr *x)
587{
588 /* Top level nodes have hit markers. See if they all are hits */
589 while (1) {
590 if (x->node != GREP_NODE_OR)
591 return x->hit;
592 if (!x->u.binary.left->hit)
593 return 0;
594 x = x->u.binary.right;
595 }
596}
597
598int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
599{
600 /*
601 * we do not have to do the two-pass grep when we do not check
602 * buffer-wide "all-match".
603 */
604 if (!opt->all_match)
605 return grep_buffer_1(opt, name, buf, size, 0);
606
607 /* Otherwise the toplevel "or" terms hit a bit differently.
608 * We first clear hit markers from them.
609 */
610 clr_hit_marker(opt->pattern_expression);
611 grep_buffer_1(opt, name, buf, size, 1);
612
613 if (!chk_hit_marker(opt->pattern_expression))
614 return 0;
615
616 return grep_buffer_1(opt, name, buf, size, 0);
617}