Merge branch 'rs/simplify-by-deco-with-deco-refs-exclude'
[git/git.git] / attr.c
1 /*
2 * Handle git attributes. See gitattributes(5) for a description of
3 * the file syntax, and Documentation/technical/api-gitattributes.txt
4 * for a description of the API.
5 *
6 * One basic design decision here is that we are not going to support
7 * an insanely large number of attributes.
8 */
9
10 #include "cache.h"
11 #include "config.h"
12 #include "exec-cmd.h"
13 #include "attr.h"
14 #include "dir.h"
15 #include "utf8.h"
16 #include "quote.h"
17 #include "thread-utils.h"
18
19 const char git_attr__true[] = "(builtin)true";
20 const char git_attr__false[] = "\0(builtin)false";
21 static const char git_attr__unknown[] = "(builtin)unknown";
22 #define ATTR__TRUE git_attr__true
23 #define ATTR__FALSE git_attr__false
24 #define ATTR__UNSET NULL
25 #define ATTR__UNKNOWN git_attr__unknown
26
27 #ifndef DEBUG_ATTR
28 #define DEBUG_ATTR 0
29 #endif
30
31 struct git_attr {
32 int attr_nr; /* unique attribute number */
33 char name[FLEX_ARRAY]; /* attribute name */
34 };
35
36 const char *git_attr_name(const struct git_attr *attr)
37 {
38 return attr->name;
39 }
40
41 struct attr_hashmap {
42 struct hashmap map;
43 pthread_mutex_t mutex;
44 };
45
46 static inline void hashmap_lock(struct attr_hashmap *map)
47 {
48 pthread_mutex_lock(&map->mutex);
49 }
50
51 static inline void hashmap_unlock(struct attr_hashmap *map)
52 {
53 pthread_mutex_unlock(&map->mutex);
54 }
55
56 /*
57 * The global dictionary of all interned attributes. This
58 * is a singleton object which is shared between threads.
59 * Access to this dictionary must be surrounded with a mutex.
60 */
61 static struct attr_hashmap g_attr_hashmap;
62
63 /* The container for objects stored in "struct attr_hashmap" */
64 struct attr_hash_entry {
65 struct hashmap_entry ent; /* must be the first member! */
66 const char *key; /* the key; memory should be owned by value */
67 size_t keylen; /* length of the key */
68 void *value; /* the stored value */
69 };
70
71 /* attr_hashmap comparison function */
72 static int attr_hash_entry_cmp(const void *unused_cmp_data,
73 const void *entry,
74 const void *entry_or_key,
75 const void *unused_keydata)
76 {
77 const struct attr_hash_entry *a = entry;
78 const struct attr_hash_entry *b = entry_or_key;
79 return (a->keylen != b->keylen) || strncmp(a->key, b->key, a->keylen);
80 }
81
82 /* Initialize an 'attr_hashmap' object */
83 static void attr_hashmap_init(struct attr_hashmap *map)
84 {
85 hashmap_init(&map->map, attr_hash_entry_cmp, NULL, 0);
86 }
87
88 /*
89 * Retrieve the 'value' stored in a hashmap given the provided 'key'.
90 * If there is no matching entry, return NULL.
91 */
92 static void *attr_hashmap_get(struct attr_hashmap *map,
93 const char *key, size_t keylen)
94 {
95 struct attr_hash_entry k;
96 struct attr_hash_entry *e;
97
98 if (!map->map.tablesize)
99 attr_hashmap_init(map);
100
101 hashmap_entry_init(&k, memhash(key, keylen));
102 k.key = key;
103 k.keylen = keylen;
104 e = hashmap_get(&map->map, &k, NULL);
105
106 return e ? e->value : NULL;
107 }
108
109 /* Add 'value' to a hashmap based on the provided 'key'. */
110 static void attr_hashmap_add(struct attr_hashmap *map,
111 const char *key, size_t keylen,
112 void *value)
113 {
114 struct attr_hash_entry *e;
115
116 if (!map->map.tablesize)
117 attr_hashmap_init(map);
118
119 e = xmalloc(sizeof(struct attr_hash_entry));
120 hashmap_entry_init(e, memhash(key, keylen));
121 e->key = key;
122 e->keylen = keylen;
123 e->value = value;
124
125 hashmap_add(&map->map, e);
126 }
127
128 struct all_attrs_item {
129 const struct git_attr *attr;
130 const char *value;
131 /*
132 * If 'macro' is non-NULL, indicates that 'attr' is a macro based on
133 * the current attribute stack and contains a pointer to the match_attr
134 * definition of the macro
135 */
136 const struct match_attr *macro;
137 };
138
139 /*
140 * Reallocate and reinitialize the array of all attributes (which is used in
141 * the attribute collection process) in 'check' based on the global dictionary
142 * of attributes.
143 */
144 static void all_attrs_init(struct attr_hashmap *map, struct attr_check *check)
145 {
146 int i;
147 unsigned int size;
148
149 hashmap_lock(map);
150
151 size = hashmap_get_size(&map->map);
152 if (size < check->all_attrs_nr)
153 BUG("interned attributes shouldn't be deleted");
154
155 /*
156 * If the number of attributes in the global dictionary has increased
157 * (or this attr_check instance doesn't have an initialized all_attrs
158 * field), reallocate the provided attr_check instance's all_attrs
159 * field and fill each entry with its corresponding git_attr.
160 */
161 if (size != check->all_attrs_nr) {
162 struct attr_hash_entry *e;
163 struct hashmap_iter iter;
164 hashmap_iter_init(&map->map, &iter);
165
166 REALLOC_ARRAY(check->all_attrs, size);
167 check->all_attrs_nr = size;
168
169 while ((e = hashmap_iter_next(&iter))) {
170 const struct git_attr *a = e->value;
171 check->all_attrs[a->attr_nr].attr = a;
172 }
173 }
174
175 hashmap_unlock(map);
176
177 /*
178 * Re-initialize every entry in check->all_attrs.
179 * This re-initialization can live outside of the locked region since
180 * the attribute dictionary is no longer being accessed.
181 */
182 for (i = 0; i < check->all_attrs_nr; i++) {
183 check->all_attrs[i].value = ATTR__UNKNOWN;
184 check->all_attrs[i].macro = NULL;
185 }
186 }
187
188 static int attr_name_valid(const char *name, size_t namelen)
189 {
190 /*
191 * Attribute name cannot begin with '-' and must consist of
192 * characters from [-A-Za-z0-9_.].
193 */
194 if (namelen <= 0 || *name == '-')
195 return 0;
196 while (namelen--) {
197 char ch = *name++;
198 if (! (ch == '-' || ch == '.' || ch == '_' ||
199 ('0' <= ch && ch <= '9') ||
200 ('a' <= ch && ch <= 'z') ||
201 ('A' <= ch && ch <= 'Z')) )
202 return 0;
203 }
204 return 1;
205 }
206
207 static void report_invalid_attr(const char *name, size_t len,
208 const char *src, int lineno)
209 {
210 struct strbuf err = STRBUF_INIT;
211 strbuf_addf(&err, _("%.*s is not a valid attribute name"),
212 (int) len, name);
213 fprintf(stderr, "%s: %s:%d\n", err.buf, src, lineno);
214 strbuf_release(&err);
215 }
216
217 /*
218 * Given a 'name', lookup and return the corresponding attribute in the global
219 * dictionary. If no entry is found, create a new attribute and store it in
220 * the dictionary.
221 */
222 static const struct git_attr *git_attr_internal(const char *name, int namelen)
223 {
224 struct git_attr *a;
225
226 if (!attr_name_valid(name, namelen))
227 return NULL;
228
229 hashmap_lock(&g_attr_hashmap);
230
231 a = attr_hashmap_get(&g_attr_hashmap, name, namelen);
232
233 if (!a) {
234 FLEX_ALLOC_MEM(a, name, name, namelen);
235 a->attr_nr = hashmap_get_size(&g_attr_hashmap.map);
236
237 attr_hashmap_add(&g_attr_hashmap, a->name, namelen, a);
238 assert(a->attr_nr ==
239 (hashmap_get_size(&g_attr_hashmap.map) - 1));
240 }
241
242 hashmap_unlock(&g_attr_hashmap);
243
244 return a;
245 }
246
247 const struct git_attr *git_attr(const char *name)
248 {
249 return git_attr_internal(name, strlen(name));
250 }
251
252 /* What does a matched pattern decide? */
253 struct attr_state {
254 const struct git_attr *attr;
255 const char *setto;
256 };
257
258 struct pattern {
259 const char *pattern;
260 int patternlen;
261 int nowildcardlen;
262 unsigned flags; /* PATTERN_FLAG_* */
263 };
264
265 /*
266 * One rule, as from a .gitattributes file.
267 *
268 * If is_macro is true, then u.attr is a pointer to the git_attr being
269 * defined.
270 *
271 * If is_macro is false, then u.pat is the filename pattern to which the
272 * rule applies.
273 *
274 * In either case, num_attr is the number of attributes affected by
275 * this rule, and state is an array listing them. The attributes are
276 * listed as they appear in the file (macros unexpanded).
277 */
278 struct match_attr {
279 union {
280 struct pattern pat;
281 const struct git_attr *attr;
282 } u;
283 char is_macro;
284 unsigned num_attr;
285 struct attr_state state[FLEX_ARRAY];
286 };
287
288 static const char blank[] = " \t\r\n";
289
290 /*
291 * Parse a whitespace-delimited attribute state (i.e., "attr",
292 * "-attr", "!attr", or "attr=value") from the string starting at src.
293 * If e is not NULL, write the results to *e. Return a pointer to the
294 * remainder of the string (with leading whitespace removed), or NULL
295 * if there was an error.
296 */
297 static const char *parse_attr(const char *src, int lineno, const char *cp,
298 struct attr_state *e)
299 {
300 const char *ep, *equals;
301 int len;
302
303 ep = cp + strcspn(cp, blank);
304 equals = strchr(cp, '=');
305 if (equals && ep < equals)
306 equals = NULL;
307 if (equals)
308 len = equals - cp;
309 else
310 len = ep - cp;
311 if (!e) {
312 if (*cp == '-' || *cp == '!') {
313 cp++;
314 len--;
315 }
316 if (!attr_name_valid(cp, len)) {
317 report_invalid_attr(cp, len, src, lineno);
318 return NULL;
319 }
320 } else {
321 /*
322 * As this function is always called twice, once with
323 * e == NULL in the first pass and then e != NULL in
324 * the second pass, no need for attr_name_valid()
325 * check here.
326 */
327 if (*cp == '-' || *cp == '!') {
328 e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
329 cp++;
330 len--;
331 }
332 else if (!equals)
333 e->setto = ATTR__TRUE;
334 else {
335 e->setto = xmemdupz(equals + 1, ep - equals - 1);
336 }
337 e->attr = git_attr_internal(cp, len);
338 }
339 return ep + strspn(ep, blank);
340 }
341
342 static struct match_attr *parse_attr_line(const char *line, const char *src,
343 int lineno, int macro_ok)
344 {
345 int namelen;
346 int num_attr, i;
347 const char *cp, *name, *states;
348 struct match_attr *res = NULL;
349 int is_macro;
350 struct strbuf pattern = STRBUF_INIT;
351
352 cp = line + strspn(line, blank);
353 if (!*cp || *cp == '#')
354 return NULL;
355 name = cp;
356
357 if (*cp == '"' && !unquote_c_style(&pattern, name, &states)) {
358 name = pattern.buf;
359 namelen = pattern.len;
360 } else {
361 namelen = strcspn(name, blank);
362 states = name + namelen;
363 }
364
365 if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
366 starts_with(name, ATTRIBUTE_MACRO_PREFIX)) {
367 if (!macro_ok) {
368 fprintf_ln(stderr, _("%s not allowed: %s:%d"),
369 name, src, lineno);
370 goto fail_return;
371 }
372 is_macro = 1;
373 name += strlen(ATTRIBUTE_MACRO_PREFIX);
374 name += strspn(name, blank);
375 namelen = strcspn(name, blank);
376 if (!attr_name_valid(name, namelen)) {
377 report_invalid_attr(name, namelen, src, lineno);
378 goto fail_return;
379 }
380 }
381 else
382 is_macro = 0;
383
384 states += strspn(states, blank);
385
386 /* First pass to count the attr_states */
387 for (cp = states, num_attr = 0; *cp; num_attr++) {
388 cp = parse_attr(src, lineno, cp, NULL);
389 if (!cp)
390 goto fail_return;
391 }
392
393 res = xcalloc(1,
394 sizeof(*res) +
395 sizeof(struct attr_state) * num_attr +
396 (is_macro ? 0 : namelen + 1));
397 if (is_macro) {
398 res->u.attr = git_attr_internal(name, namelen);
399 } else {
400 char *p = (char *)&(res->state[num_attr]);
401 memcpy(p, name, namelen);
402 res->u.pat.pattern = p;
403 parse_path_pattern(&res->u.pat.pattern,
404 &res->u.pat.patternlen,
405 &res->u.pat.flags,
406 &res->u.pat.nowildcardlen);
407 if (res->u.pat.flags & PATTERN_FLAG_NEGATIVE) {
408 warning(_("Negative patterns are ignored in git attributes\n"
409 "Use '\\!' for literal leading exclamation."));
410 goto fail_return;
411 }
412 }
413 res->is_macro = is_macro;
414 res->num_attr = num_attr;
415
416 /* Second pass to fill the attr_states */
417 for (cp = states, i = 0; *cp; i++) {
418 cp = parse_attr(src, lineno, cp, &(res->state[i]));
419 }
420
421 strbuf_release(&pattern);
422 return res;
423
424 fail_return:
425 strbuf_release(&pattern);
426 free(res);
427 return NULL;
428 }
429
430 /*
431 * Like info/exclude and .gitignore, the attribute information can
432 * come from many places.
433 *
434 * (1) .gitattributes file of the same directory;
435 * (2) .gitattributes file of the parent directory if (1) does not have
436 * any match; this goes recursively upwards, just like .gitignore.
437 * (3) $GIT_DIR/info/attributes, which overrides both of the above.
438 *
439 * In the same file, later entries override the earlier match, so in the
440 * global list, we would have entries from info/attributes the earliest
441 * (reading the file from top to bottom), .gitattributes of the root
442 * directory (again, reading the file from top to bottom) down to the
443 * current directory, and then scan the list backwards to find the first match.
444 * This is exactly the same as what is_excluded() does in dir.c to deal with
445 * .gitignore file and info/excludes file as a fallback.
446 */
447
448 struct attr_stack {
449 struct attr_stack *prev;
450 char *origin;
451 size_t originlen;
452 unsigned num_matches;
453 unsigned alloc;
454 struct match_attr **attrs;
455 };
456
457 static void attr_stack_free(struct attr_stack *e)
458 {
459 int i;
460 free(e->origin);
461 for (i = 0; i < e->num_matches; i++) {
462 struct match_attr *a = e->attrs[i];
463 int j;
464 for (j = 0; j < a->num_attr; j++) {
465 const char *setto = a->state[j].setto;
466 if (setto == ATTR__TRUE ||
467 setto == ATTR__FALSE ||
468 setto == ATTR__UNSET ||
469 setto == ATTR__UNKNOWN)
470 ;
471 else
472 free((char *) setto);
473 }
474 free(a);
475 }
476 free(e->attrs);
477 free(e);
478 }
479
480 static void drop_attr_stack(struct attr_stack **stack)
481 {
482 while (*stack) {
483 struct attr_stack *elem = *stack;
484 *stack = elem->prev;
485 attr_stack_free(elem);
486 }
487 }
488
489 /* List of all attr_check structs; access should be surrounded by mutex */
490 static struct check_vector {
491 size_t nr;
492 size_t alloc;
493 struct attr_check **checks;
494 pthread_mutex_t mutex;
495 } check_vector;
496
497 static inline void vector_lock(void)
498 {
499 pthread_mutex_lock(&check_vector.mutex);
500 }
501
502 static inline void vector_unlock(void)
503 {
504 pthread_mutex_unlock(&check_vector.mutex);
505 }
506
507 static void check_vector_add(struct attr_check *c)
508 {
509 vector_lock();
510
511 ALLOC_GROW(check_vector.checks,
512 check_vector.nr + 1,
513 check_vector.alloc);
514 check_vector.checks[check_vector.nr++] = c;
515
516 vector_unlock();
517 }
518
519 static void check_vector_remove(struct attr_check *check)
520 {
521 int i;
522
523 vector_lock();
524
525 /* Find entry */
526 for (i = 0; i < check_vector.nr; i++)
527 if (check_vector.checks[i] == check)
528 break;
529
530 if (i >= check_vector.nr)
531 BUG("no entry found");
532
533 /* shift entries over */
534 for (; i < check_vector.nr - 1; i++)
535 check_vector.checks[i] = check_vector.checks[i + 1];
536
537 check_vector.nr--;
538
539 vector_unlock();
540 }
541
542 /* Iterate through all attr_check instances and drop their stacks */
543 static void drop_all_attr_stacks(void)
544 {
545 int i;
546
547 vector_lock();
548
549 for (i = 0; i < check_vector.nr; i++) {
550 drop_attr_stack(&check_vector.checks[i]->stack);
551 }
552
553 vector_unlock();
554 }
555
556 struct attr_check *attr_check_alloc(void)
557 {
558 struct attr_check *c = xcalloc(1, sizeof(struct attr_check));
559
560 /* save pointer to the check struct */
561 check_vector_add(c);
562
563 return c;
564 }
565
566 struct attr_check *attr_check_initl(const char *one, ...)
567 {
568 struct attr_check *check;
569 int cnt;
570 va_list params;
571 const char *param;
572
573 va_start(params, one);
574 for (cnt = 1; (param = va_arg(params, const char *)) != NULL; cnt++)
575 ;
576 va_end(params);
577
578 check = attr_check_alloc();
579 check->nr = cnt;
580 check->alloc = cnt;
581 check->items = xcalloc(cnt, sizeof(struct attr_check_item));
582
583 check->items[0].attr = git_attr(one);
584 va_start(params, one);
585 for (cnt = 1; cnt < check->nr; cnt++) {
586 const struct git_attr *attr;
587 param = va_arg(params, const char *);
588 if (!param)
589 BUG("counted %d != ended at %d",
590 check->nr, cnt);
591 attr = git_attr(param);
592 if (!attr)
593 BUG("%s: not a valid attribute name", param);
594 check->items[cnt].attr = attr;
595 }
596 va_end(params);
597 return check;
598 }
599
600 struct attr_check *attr_check_dup(const struct attr_check *check)
601 {
602 struct attr_check *ret;
603
604 if (!check)
605 return NULL;
606
607 ret = attr_check_alloc();
608
609 ret->nr = check->nr;
610 ret->alloc = check->alloc;
611 ALLOC_ARRAY(ret->items, ret->nr);
612 COPY_ARRAY(ret->items, check->items, ret->nr);
613
614 return ret;
615 }
616
617 struct attr_check_item *attr_check_append(struct attr_check *check,
618 const struct git_attr *attr)
619 {
620 struct attr_check_item *item;
621
622 ALLOC_GROW(check->items, check->nr + 1, check->alloc);
623 item = &check->items[check->nr++];
624 item->attr = attr;
625 return item;
626 }
627
628 void attr_check_reset(struct attr_check *check)
629 {
630 check->nr = 0;
631 }
632
633 void attr_check_clear(struct attr_check *check)
634 {
635 FREE_AND_NULL(check->items);
636 check->alloc = 0;
637 check->nr = 0;
638
639 FREE_AND_NULL(check->all_attrs);
640 check->all_attrs_nr = 0;
641
642 drop_attr_stack(&check->stack);
643 }
644
645 void attr_check_free(struct attr_check *check)
646 {
647 if (check) {
648 /* Remove check from the check vector */
649 check_vector_remove(check);
650
651 attr_check_clear(check);
652 free(check);
653 }
654 }
655
656 static const char *builtin_attr[] = {
657 "[attr]binary -diff -merge -text",
658 NULL,
659 };
660
661 static void handle_attr_line(struct attr_stack *res,
662 const char *line,
663 const char *src,
664 int lineno,
665 int macro_ok)
666 {
667 struct match_attr *a;
668
669 a = parse_attr_line(line, src, lineno, macro_ok);
670 if (!a)
671 return;
672 ALLOC_GROW(res->attrs, res->num_matches + 1, res->alloc);
673 res->attrs[res->num_matches++] = a;
674 }
675
676 static struct attr_stack *read_attr_from_array(const char **list)
677 {
678 struct attr_stack *res;
679 const char *line;
680 int lineno = 0;
681
682 res = xcalloc(1, sizeof(*res));
683 while ((line = *(list++)) != NULL)
684 handle_attr_line(res, line, "[builtin]", ++lineno, 1);
685 return res;
686 }
687
688 /*
689 * Callers into the attribute system assume there is a single, system-wide
690 * global state where attributes are read from and when the state is flipped by
691 * calling git_attr_set_direction(), the stack frames that have been
692 * constructed need to be discarded so so that subsequent calls into the
693 * attribute system will lazily read from the right place. Since changing
694 * direction causes a global paradigm shift, it should not ever be called while
695 * another thread could potentially be calling into the attribute system.
696 */
697 static enum git_attr_direction direction;
698
699 void git_attr_set_direction(enum git_attr_direction new_direction)
700 {
701 if (is_bare_repository() && new_direction != GIT_ATTR_INDEX)
702 BUG("non-INDEX attr direction in a bare repo");
703
704 if (new_direction != direction)
705 drop_all_attr_stacks();
706
707 direction = new_direction;
708 }
709
710 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
711 {
712 FILE *fp = fopen_or_warn(path, "r");
713 struct attr_stack *res;
714 char buf[2048];
715 int lineno = 0;
716
717 if (!fp)
718 return NULL;
719 res = xcalloc(1, sizeof(*res));
720 while (fgets(buf, sizeof(buf), fp)) {
721 char *bufp = buf;
722 if (!lineno)
723 skip_utf8_bom(&bufp, strlen(bufp));
724 handle_attr_line(res, bufp, path, ++lineno, macro_ok);
725 }
726 fclose(fp);
727 return res;
728 }
729
730 static struct attr_stack *read_attr_from_index(const struct index_state *istate,
731 const char *path,
732 int macro_ok)
733 {
734 struct attr_stack *res;
735 char *buf, *sp;
736 int lineno = 0;
737
738 if (!istate)
739 return NULL;
740
741 buf = read_blob_data_from_index(istate, path, NULL);
742 if (!buf)
743 return NULL;
744
745 res = xcalloc(1, sizeof(*res));
746 for (sp = buf; *sp; ) {
747 char *ep;
748 int more;
749
750 ep = strchrnul(sp, '\n');
751 more = (*ep == '\n');
752 *ep = '\0';
753 handle_attr_line(res, sp, path, ++lineno, macro_ok);
754 sp = ep + more;
755 }
756 free(buf);
757 return res;
758 }
759
760 static struct attr_stack *read_attr(const struct index_state *istate,
761 const char *path, int macro_ok)
762 {
763 struct attr_stack *res = NULL;
764
765 if (direction == GIT_ATTR_INDEX) {
766 res = read_attr_from_index(istate, path, macro_ok);
767 } else if (!is_bare_repository()) {
768 if (direction == GIT_ATTR_CHECKOUT) {
769 res = read_attr_from_index(istate, path, macro_ok);
770 if (!res)
771 res = read_attr_from_file(path, macro_ok);
772 } else if (direction == GIT_ATTR_CHECKIN) {
773 res = read_attr_from_file(path, macro_ok);
774 if (!res)
775 /*
776 * There is no checked out .gitattributes file
777 * there, but we might have it in the index.
778 * We allow operation in a sparsely checked out
779 * work tree, so read from it.
780 */
781 res = read_attr_from_index(istate, path, macro_ok);
782 }
783 }
784
785 if (!res)
786 res = xcalloc(1, sizeof(*res));
787 return res;
788 }
789
790 #if DEBUG_ATTR
791 static void debug_info(const char *what, struct attr_stack *elem)
792 {
793 fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
794 }
795 static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v)
796 {
797 const char *value = v;
798
799 if (ATTR_TRUE(value))
800 value = "set";
801 else if (ATTR_FALSE(value))
802 value = "unset";
803 else if (ATTR_UNSET(value))
804 value = "unspecified";
805
806 fprintf(stderr, "%s: %s => %s (%s)\n",
807 what, attr->name, (char *) value, match);
808 }
809 #define debug_push(a) debug_info("push", (a))
810 #define debug_pop(a) debug_info("pop", (a))
811 #else
812 #define debug_push(a) do { ; } while (0)
813 #define debug_pop(a) do { ; } while (0)
814 #define debug_set(a,b,c,d) do { ; } while (0)
815 #endif /* DEBUG_ATTR */
816
817 static const char *git_etc_gitattributes(void)
818 {
819 static const char *system_wide;
820 if (!system_wide)
821 system_wide = system_path(ETC_GITATTRIBUTES);
822 return system_wide;
823 }
824
825 static const char *get_home_gitattributes(void)
826 {
827 if (!git_attributes_file)
828 git_attributes_file = xdg_config_home("attributes");
829
830 return git_attributes_file;
831 }
832
833 static int git_attr_system(void)
834 {
835 return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
836 }
837
838 static GIT_PATH_FUNC(git_path_info_attributes, INFOATTRIBUTES_FILE)
839
840 static void push_stack(struct attr_stack **attr_stack_p,
841 struct attr_stack *elem, char *origin, size_t originlen)
842 {
843 if (elem) {
844 elem->origin = origin;
845 if (origin)
846 elem->originlen = originlen;
847 elem->prev = *attr_stack_p;
848 *attr_stack_p = elem;
849 }
850 }
851
852 static void bootstrap_attr_stack(const struct index_state *istate,
853 struct attr_stack **stack)
854 {
855 struct attr_stack *e;
856
857 if (*stack)
858 return;
859
860 /* builtin frame */
861 e = read_attr_from_array(builtin_attr);
862 push_stack(stack, e, NULL, 0);
863
864 /* system-wide frame */
865 if (git_attr_system()) {
866 e = read_attr_from_file(git_etc_gitattributes(), 1);
867 push_stack(stack, e, NULL, 0);
868 }
869
870 /* home directory */
871 if (get_home_gitattributes()) {
872 e = read_attr_from_file(get_home_gitattributes(), 1);
873 push_stack(stack, e, NULL, 0);
874 }
875
876 /* root directory */
877 e = read_attr(istate, GITATTRIBUTES_FILE, 1);
878 push_stack(stack, e, xstrdup(""), 0);
879
880 /* info frame */
881 if (startup_info->have_repository)
882 e = read_attr_from_file(git_path_info_attributes(), 1);
883 else
884 e = NULL;
885 if (!e)
886 e = xcalloc(1, sizeof(struct attr_stack));
887 push_stack(stack, e, NULL, 0);
888 }
889
890 static void prepare_attr_stack(const struct index_state *istate,
891 const char *path, int dirlen,
892 struct attr_stack **stack)
893 {
894 struct attr_stack *info;
895 struct strbuf pathbuf = STRBUF_INIT;
896
897 /*
898 * At the bottom of the attribute stack is the built-in
899 * set of attribute definitions, followed by the contents
900 * of $(prefix)/etc/gitattributes and a file specified by
901 * core.attributesfile. Then, contents from
902 * .gitattributes files from directories closer to the
903 * root to the ones in deeper directories are pushed
904 * to the stack. Finally, at the very top of the stack
905 * we always keep the contents of $GIT_DIR/info/attributes.
906 *
907 * When checking, we use entries from near the top of the
908 * stack, preferring $GIT_DIR/info/attributes, then
909 * .gitattributes in deeper directories to shallower ones,
910 * and finally use the built-in set as the default.
911 */
912 bootstrap_attr_stack(istate, stack);
913
914 /*
915 * Pop the "info" one that is always at the top of the stack.
916 */
917 info = *stack;
918 *stack = info->prev;
919
920 /*
921 * Pop the ones from directories that are not the prefix of
922 * the path we are checking. Break out of the loop when we see
923 * the root one (whose origin is an empty string "") or the builtin
924 * one (whose origin is NULL) without popping it.
925 */
926 while ((*stack)->origin) {
927 int namelen = (*stack)->originlen;
928 struct attr_stack *elem;
929
930 elem = *stack;
931 if (namelen <= dirlen &&
932 !strncmp(elem->origin, path, namelen) &&
933 (!namelen || path[namelen] == '/'))
934 break;
935
936 debug_pop(elem);
937 *stack = elem->prev;
938 attr_stack_free(elem);
939 }
940
941 /*
942 * bootstrap_attr_stack() should have added, and the
943 * above loop should have stopped before popping, the
944 * root element whose attr_stack->origin is set to an
945 * empty string.
946 */
947 assert((*stack)->origin);
948
949 strbuf_addstr(&pathbuf, (*stack)->origin);
950 /* Build up to the directory 'path' is in */
951 while (pathbuf.len < dirlen) {
952 size_t len = pathbuf.len;
953 struct attr_stack *next;
954 char *origin;
955
956 /* Skip path-separator */
957 if (len < dirlen && is_dir_sep(path[len]))
958 len++;
959 /* Find the end of the next component */
960 while (len < dirlen && !is_dir_sep(path[len]))
961 len++;
962
963 if (pathbuf.len > 0)
964 strbuf_addch(&pathbuf, '/');
965 strbuf_add(&pathbuf, path + pathbuf.len, (len - pathbuf.len));
966 strbuf_addf(&pathbuf, "/%s", GITATTRIBUTES_FILE);
967
968 next = read_attr(istate, pathbuf.buf, 0);
969
970 /* reset the pathbuf to not include "/.gitattributes" */
971 strbuf_setlen(&pathbuf, len);
972
973 origin = xstrdup(pathbuf.buf);
974 push_stack(stack, next, origin, len);
975 }
976
977 /*
978 * Finally push the "info" one at the top of the stack.
979 */
980 push_stack(stack, info, NULL, 0);
981
982 strbuf_release(&pathbuf);
983 }
984
985 static int path_matches(const char *pathname, int pathlen,
986 int basename_offset,
987 const struct pattern *pat,
988 const char *base, int baselen)
989 {
990 const char *pattern = pat->pattern;
991 int prefix = pat->nowildcardlen;
992 int isdir = (pathlen && pathname[pathlen - 1] == '/');
993
994 if ((pat->flags & PATTERN_FLAG_MUSTBEDIR) && !isdir)
995 return 0;
996
997 if (pat->flags & PATTERN_FLAG_NODIR) {
998 return match_basename(pathname + basename_offset,
999 pathlen - basename_offset - isdir,
1000 pattern, prefix,
1001 pat->patternlen, pat->flags);
1002 }
1003 return match_pathname(pathname, pathlen - isdir,
1004 base, baselen,
1005 pattern, prefix, pat->patternlen, pat->flags);
1006 }
1007
1008 static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem);
1009
1010 static int fill_one(const char *what, struct all_attrs_item *all_attrs,
1011 const struct match_attr *a, int rem)
1012 {
1013 int i;
1014
1015 for (i = a->num_attr - 1; rem > 0 && i >= 0; i--) {
1016 const struct git_attr *attr = a->state[i].attr;
1017 const char **n = &(all_attrs[attr->attr_nr].value);
1018 const char *v = a->state[i].setto;
1019
1020 if (*n == ATTR__UNKNOWN) {
1021 debug_set(what,
1022 a->is_macro ? a->u.attr->name : a->u.pat.pattern,
1023 attr, v);
1024 *n = v;
1025 rem--;
1026 rem = macroexpand_one(all_attrs, attr->attr_nr, rem);
1027 }
1028 }
1029 return rem;
1030 }
1031
1032 static int fill(const char *path, int pathlen, int basename_offset,
1033 const struct attr_stack *stack,
1034 struct all_attrs_item *all_attrs, int rem)
1035 {
1036 for (; rem > 0 && stack; stack = stack->prev) {
1037 int i;
1038 const char *base = stack->origin ? stack->origin : "";
1039
1040 for (i = stack->num_matches - 1; 0 < rem && 0 <= i; i--) {
1041 const struct match_attr *a = stack->attrs[i];
1042 if (a->is_macro)
1043 continue;
1044 if (path_matches(path, pathlen, basename_offset,
1045 &a->u.pat, base, stack->originlen))
1046 rem = fill_one("fill", all_attrs, a, rem);
1047 }
1048 }
1049
1050 return rem;
1051 }
1052
1053 static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem)
1054 {
1055 const struct all_attrs_item *item = &all_attrs[nr];
1056
1057 if (item->macro && item->value == ATTR__TRUE)
1058 return fill_one("expand", all_attrs, item->macro, rem);
1059 else
1060 return rem;
1061 }
1062
1063 /*
1064 * Marks the attributes which are macros based on the attribute stack.
1065 * This prevents having to search through the attribute stack each time
1066 * a macro needs to be expanded during the fill stage.
1067 */
1068 static void determine_macros(struct all_attrs_item *all_attrs,
1069 const struct attr_stack *stack)
1070 {
1071 for (; stack; stack = stack->prev) {
1072 int i;
1073 for (i = stack->num_matches - 1; i >= 0; i--) {
1074 const struct match_attr *ma = stack->attrs[i];
1075 if (ma->is_macro) {
1076 int n = ma->u.attr->attr_nr;
1077 if (!all_attrs[n].macro) {
1078 all_attrs[n].macro = ma;
1079 }
1080 }
1081 }
1082 }
1083 }
1084
1085 /*
1086 * Collect attributes for path into the array pointed to by check->all_attrs.
1087 * If check->check_nr is non-zero, only attributes in check[] are collected.
1088 * Otherwise all attributes are collected.
1089 */
1090 static void collect_some_attrs(const struct index_state *istate,
1091 const char *path,
1092 struct attr_check *check)
1093 {
1094 int pathlen, rem, dirlen;
1095 const char *cp, *last_slash = NULL;
1096 int basename_offset;
1097
1098 for (cp = path; *cp; cp++) {
1099 if (*cp == '/' && cp[1])
1100 last_slash = cp;
1101 }
1102 pathlen = cp - path;
1103 if (last_slash) {
1104 basename_offset = last_slash + 1 - path;
1105 dirlen = last_slash - path;
1106 } else {
1107 basename_offset = 0;
1108 dirlen = 0;
1109 }
1110
1111 prepare_attr_stack(istate, path, dirlen, &check->stack);
1112 all_attrs_init(&g_attr_hashmap, check);
1113 determine_macros(check->all_attrs, check->stack);
1114
1115 rem = check->all_attrs_nr;
1116 fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
1117 }
1118
1119 void git_check_attr(const struct index_state *istate,
1120 const char *path,
1121 struct attr_check *check)
1122 {
1123 int i;
1124
1125 collect_some_attrs(istate, path, check);
1126
1127 for (i = 0; i < check->nr; i++) {
1128 size_t n = check->items[i].attr->attr_nr;
1129 const char *value = check->all_attrs[n].value;
1130 if (value == ATTR__UNKNOWN)
1131 value = ATTR__UNSET;
1132 check->items[i].value = value;
1133 }
1134 }
1135
1136 void git_all_attrs(const struct index_state *istate,
1137 const char *path, struct attr_check *check)
1138 {
1139 int i;
1140
1141 attr_check_reset(check);
1142 collect_some_attrs(istate, path, check);
1143
1144 for (i = 0; i < check->all_attrs_nr; i++) {
1145 const char *name = check->all_attrs[i].attr->name;
1146 const char *value = check->all_attrs[i].value;
1147 struct attr_check_item *item;
1148 if (value == ATTR__UNSET || value == ATTR__UNKNOWN)
1149 continue;
1150 item = attr_check_append(check, git_attr(name));
1151 item->value = value;
1152 }
1153 }
1154
1155 void attr_start(void)
1156 {
1157 pthread_mutex_init(&g_attr_hashmap.mutex, NULL);
1158 pthread_mutex_init(&check_vector.mutex, NULL);
1159 }