Documentation/git-show-branch: work around "single quote" typesetting glitch
[alt-git.git] / grep.c
blob600f69f2fe2a0271f4bdf736f95f70c8f7381aa4
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 void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
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);
50 static struct grep_expr *compile_pattern_or(struct grep_pat **);
51 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
53 struct grep_pat *p;
54 struct grep_expr *x;
56 p = *list;
57 switch (p->token) {
58 case GREP_PATTERN: /* atom */
59 case GREP_PATTERN_HEAD:
60 case GREP_PATTERN_BODY:
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;
68 x = compile_pattern_or(list);
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;
80 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
82 struct grep_pat *p;
83 struct grep_expr *x;
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);
102 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
104 struct grep_pat *p;
105 struct grep_expr *x, *y, *z;
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;
122 return x;
125 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
127 struct grep_pat *p;
128 struct grep_expr *x, *y, *z;
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;
142 return x;
145 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
147 return compile_pattern_or(list);
150 void compile_grep_patterns(struct grep_opt *opt)
152 struct grep_pat *p;
154 if (opt->all_match)
155 opt->extended = 1;
157 for (p = opt->pattern_list; p; p = p->next) {
158 switch (p->token) {
159 case GREP_PATTERN: /* atom */
160 case GREP_PATTERN_HEAD:
161 case GREP_PATTERN_BODY:
162 if (!opt->fixed)
163 compile_regexp(p, opt);
164 break;
165 default:
166 opt->extended = 1;
167 break;
171 if (!opt->extended)
172 return;
174 /* Then bundle them up in an expression.
175 * A classic recursive descent parser would do.
177 p = opt->pattern_list;
178 opt->pattern_expression = compile_pattern_expr(&p);
179 if (p)
180 die("incomplete pattern expression: %s", p->pattern);
183 static void free_pattern_expr(struct grep_expr *x)
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;
197 free(x);
200 void free_grep_patterns(struct grep_opt *opt)
202 struct grep_pat *p, *n;
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;
215 free(p);
218 if (!opt->extended)
219 return;
220 free_pattern_expr(opt->pattern_expression);
223 static char *end_of_line(char *cp, unsigned long *left)
225 unsigned long l = *left;
226 while (l && *cp != '\n') {
227 l--;
228 cp++;
230 *left = l;
231 return cp;
234 static int word_char(char ch)
236 return isalnum(ch) || ch == '_';
239 static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
240 const char *name, unsigned lno, char sign)
242 if (opt->null_following_name)
243 sign = '\0';
244 if (opt->pathname)
245 printf("%s%c", name, sign);
246 if (opt->linenum)
247 printf("%d%c", lno, sign);
248 printf("%.*s\n", (int)(eol-bol), bol);
251 static void show_name(struct grep_opt *opt, const char *name)
253 printf("%s%c", name, opt->null_following_name ? '\0' : '\n');
256 static int fixmatch(const char *pattern, char *line, regmatch_t *match)
258 char *hit = strstr(line, pattern);
259 if (!hit) {
260 match->rm_so = match->rm_eo = -1;
261 return REG_NOMATCH;
263 else {
264 match->rm_so = hit - line;
265 match->rm_eo = match->rm_so + strlen(pattern);
266 return 0;
270 static int strip_timestamp(char *bol, char **eol_p)
272 char *eol = *eol_p;
273 int ch;
275 while (bol < --eol) {
276 if (*eol != '>')
277 continue;
278 *eol_p = ++eol;
279 ch = *eol;
280 *eol = '\0';
281 return ch;
283 return 0;
286 static struct {
287 const char *field;
288 size_t len;
289 } header_field[] = {
290 { "author ", 7 },
291 { "committer ", 10 },
294 static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol, enum grep_context ctx)
296 int hit = 0;
297 int at_true_bol = 1;
298 int saved_ch = 0;
299 regmatch_t pmatch[10];
301 if ((p->token != GREP_PATTERN) &&
302 ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
303 return 0;
305 if (p->token == GREP_PATTERN_HEAD) {
306 const char *field;
307 size_t len;
308 assert(p->field < ARRAY_SIZE(header_field));
309 field = header_field[p->field].field;
310 len = header_field[p->field].len;
311 if (strncmp(bol, field, len))
312 return 0;
313 bol += len;
314 saved_ch = strip_timestamp(bol, &eol);
317 again:
318 if (!opt->fixed) {
319 regex_t *exp = &p->regexp;
320 hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
321 pmatch, 0);
323 else {
324 hit = !fixmatch(p->pattern, bol, pmatch);
327 if (hit && opt->word_regexp) {
328 if ((pmatch[0].rm_so < 0) ||
329 (eol - bol) <= pmatch[0].rm_so ||
330 (pmatch[0].rm_eo < 0) ||
331 (eol - bol) < pmatch[0].rm_eo)
332 die("regexp returned nonsense");
334 /* Match beginning must be either beginning of the
335 * line, or at word boundary (i.e. the last char must
336 * not be a word char). Similarly, match end must be
337 * either end of the line, or at word boundary
338 * (i.e. the next char must not be a word char).
340 if ( ((pmatch[0].rm_so == 0 && at_true_bol) ||
341 !word_char(bol[pmatch[0].rm_so-1])) &&
342 ((pmatch[0].rm_eo == (eol-bol)) ||
343 !word_char(bol[pmatch[0].rm_eo])) )
345 else
346 hit = 0;
348 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
349 /* There could be more than one match on the
350 * line, and the first match might not be
351 * strict word match. But later ones could be!
353 bol = pmatch[0].rm_so + bol + 1;
354 at_true_bol = 0;
355 goto again;
358 if (p->token == GREP_PATTERN_HEAD && saved_ch)
359 *eol = saved_ch;
360 return hit;
363 static int match_expr_eval(struct grep_opt *o,
364 struct grep_expr *x,
365 char *bol, char *eol,
366 enum grep_context ctx,
367 int collect_hits)
369 int h = 0;
371 switch (x->node) {
372 case GREP_NODE_ATOM:
373 h = match_one_pattern(o, x->u.atom, bol, eol, ctx);
374 break;
375 case GREP_NODE_NOT:
376 h = !match_expr_eval(o, x->u.unary, bol, eol, ctx, 0);
377 break;
378 case GREP_NODE_AND:
379 if (!collect_hits)
380 return (match_expr_eval(o, x->u.binary.left,
381 bol, eol, ctx, 0) &&
382 match_expr_eval(o, x->u.binary.right,
383 bol, eol, ctx, 0));
384 h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0);
385 h &= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 0);
386 break;
387 case GREP_NODE_OR:
388 if (!collect_hits)
389 return (match_expr_eval(o, x->u.binary.left,
390 bol, eol, ctx, 0) ||
391 match_expr_eval(o, x->u.binary.right,
392 bol, eol, ctx, 0));
393 h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0);
394 x->u.binary.left->hit |= h;
395 h |= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 1);
396 break;
397 default:
398 die("Unexpected node type (internal error) %d\n", 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(opt, 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 if (opt->extended)
417 return match_expr(opt, bol, eol, ctx, collect_hits);
419 /* we do not call with collect_hits without being extended */
420 for (p = opt->pattern_list; p; p = p->next) {
421 if (match_one_pattern(opt, p, bol, eol, ctx))
422 return 1;
424 return 0;
427 static int grep_buffer_1(struct grep_opt *opt, const char *name,
428 char *buf, unsigned long size, int collect_hits)
430 char *bol = buf;
431 unsigned long left = size;
432 unsigned lno = 1;
433 struct pre_context_line {
434 char *bol;
435 char *eol;
436 } *prev = NULL, *pcl;
437 unsigned last_hit = 0;
438 unsigned last_shown = 0;
439 int binary_match_only = 0;
440 const char *hunk_mark = "";
441 unsigned count = 0;
442 enum grep_context ctx = GREP_CONTEXT_HEAD;
444 if (buffer_is_binary(buf, size)) {
445 switch (opt->binary) {
446 case GREP_BINARY_DEFAULT:
447 binary_match_only = 1;
448 break;
449 case GREP_BINARY_NOMATCH:
450 return 0; /* Assume unmatch */
451 break;
452 default:
453 break;
457 if (opt->pre_context)
458 prev = xcalloc(opt->pre_context, sizeof(*prev));
459 if (opt->pre_context || opt->post_context)
460 hunk_mark = "--\n";
462 while (left) {
463 char *eol, ch;
464 int hit;
466 eol = end_of_line(bol, &left);
467 ch = *eol;
468 *eol = 0;
470 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
471 ctx = GREP_CONTEXT_BODY;
473 hit = match_line(opt, bol, eol, ctx, collect_hits);
474 *eol = ch;
476 if (collect_hits)
477 goto next_line;
479 /* "grep -v -e foo -e bla" should list lines
480 * that do not have either, so inversion should
481 * be done outside.
483 if (opt->invert)
484 hit = !hit;
485 if (opt->unmatch_name_only) {
486 if (hit)
487 return 0;
488 goto next_line;
490 if (hit) {
491 count++;
492 if (opt->status_only)
493 return 1;
494 if (binary_match_only) {
495 printf("Binary file %s matches\n", name);
496 return 1;
498 if (opt->name_only) {
499 show_name(opt, name);
500 return 1;
502 /* Hit at this line. If we haven't shown the
503 * pre-context lines, we would need to show them.
504 * When asked to do "count", this still show
505 * the context which is nonsense, but the user
506 * deserves to get that ;-).
508 if (opt->pre_context) {
509 unsigned from;
510 if (opt->pre_context < lno)
511 from = lno - opt->pre_context;
512 else
513 from = 1;
514 if (from <= last_shown)
515 from = last_shown + 1;
516 if (last_shown && from != last_shown + 1)
517 fputs(hunk_mark, stdout);
518 while (from < lno) {
519 pcl = &prev[lno-from-1];
520 show_line(opt, pcl->bol, pcl->eol,
521 name, from, '-');
522 from++;
524 last_shown = lno-1;
526 if (last_shown && lno != last_shown + 1)
527 fputs(hunk_mark, stdout);
528 if (!opt->count)
529 show_line(opt, bol, eol, name, lno, ':');
530 last_shown = last_hit = lno;
532 else if (last_hit &&
533 lno <= last_hit + opt->post_context) {
534 /* If the last hit is within the post context,
535 * we need to show this line.
537 if (last_shown && lno != last_shown + 1)
538 fputs(hunk_mark, stdout);
539 show_line(opt, bol, eol, name, lno, '-');
540 last_shown = lno;
542 if (opt->pre_context) {
543 memmove(prev+1, prev,
544 (opt->pre_context-1) * sizeof(*prev));
545 prev->bol = bol;
546 prev->eol = eol;
549 next_line:
550 bol = eol + 1;
551 if (!left)
552 break;
553 left--;
554 lno++;
557 free(prev);
558 if (collect_hits)
559 return 0;
561 if (opt->status_only)
562 return 0;
563 if (opt->unmatch_name_only) {
564 /* We did not see any hit, so we want to show this */
565 show_name(opt, name);
566 return 1;
569 /* NEEDSWORK:
570 * The real "grep -c foo *.c" gives many "bar.c:0" lines,
571 * which feels mostly useless but sometimes useful. Maybe
572 * make it another option? For now suppress them.
574 if (opt->count && count)
575 printf("%s%c%u\n", name,
576 opt->null_following_name ? '\0' : ':', count);
577 return !!last_hit;
580 static void clr_hit_marker(struct grep_expr *x)
582 /* All-hit markers are meaningful only at the very top level
583 * OR node.
585 while (1) {
586 x->hit = 0;
587 if (x->node != GREP_NODE_OR)
588 return;
589 x->u.binary.left->hit = 0;
590 x = x->u.binary.right;
594 static int chk_hit_marker(struct grep_expr *x)
596 /* Top level nodes have hit markers. See if they all are hits */
597 while (1) {
598 if (x->node != GREP_NODE_OR)
599 return x->hit;
600 if (!x->u.binary.left->hit)
601 return 0;
602 x = x->u.binary.right;
606 int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
609 * we do not have to do the two-pass grep when we do not check
610 * buffer-wide "all-match".
612 if (!opt->all_match)
613 return grep_buffer_1(opt, name, buf, size, 0);
615 /* Otherwise the toplevel "or" terms hit a bit differently.
616 * We first clear hit markers from them.
618 clr_hit_marker(opt->pattern_expression);
619 grep_buffer_1(opt, name, buf, size, 1);
621 if (!chk_hit_marker(opt->pattern_expression))
622 return 0;
624 return grep_buffer_1(opt, name, buf, size, 0);