worktree: introduce is_shared_symref()
[alt-git.git] / attr.c
blob7783b87d8a965fd7ec80ec8745289978ae2d1753
1 /*
2 * Handle git attributes. See gitattributes(5) for a description of
3 * the file syntax, and attr.h for a description of the API.
5 * One basic design decision here is that we are not going to support
6 * an insanely large number of attributes.
7 */
9 #include "cache.h"
10 #include "config.h"
11 #include "exec-cmd.h"
12 #include "attr.h"
13 #include "dir.h"
14 #include "utf8.h"
15 #include "quote.h"
16 #include "thread-utils.h"
18 const char git_attr__true[] = "(builtin)true";
19 const char git_attr__false[] = "\0(builtin)false";
20 static const char git_attr__unknown[] = "(builtin)unknown";
21 #define ATTR__TRUE git_attr__true
22 #define ATTR__FALSE git_attr__false
23 #define ATTR__UNSET NULL
24 #define ATTR__UNKNOWN git_attr__unknown
26 struct git_attr {
27 unsigned int attr_nr; /* unique attribute number */
28 char name[FLEX_ARRAY]; /* attribute name */
31 const char *git_attr_name(const struct git_attr *attr)
33 return attr->name;
36 struct attr_hashmap {
37 struct hashmap map;
38 pthread_mutex_t mutex;
41 static inline void hashmap_lock(struct attr_hashmap *map)
43 pthread_mutex_lock(&map->mutex);
46 static inline void hashmap_unlock(struct attr_hashmap *map)
48 pthread_mutex_unlock(&map->mutex);
51 /* The container for objects stored in "struct attr_hashmap" */
52 struct attr_hash_entry {
53 struct hashmap_entry ent;
54 const char *key; /* the key; memory should be owned by value */
55 size_t keylen; /* length of the key */
56 void *value; /* the stored value */
59 /* attr_hashmap comparison function */
60 static int attr_hash_entry_cmp(const void *cmp_data UNUSED,
61 const struct hashmap_entry *eptr,
62 const struct hashmap_entry *entry_or_key,
63 const void *keydata UNUSED)
65 const struct attr_hash_entry *a, *b;
67 a = container_of(eptr, const struct attr_hash_entry, ent);
68 b = container_of(entry_or_key, const struct attr_hash_entry, ent);
69 return (a->keylen != b->keylen) || strncmp(a->key, b->key, a->keylen);
73 * The global dictionary of all interned attributes. This
74 * is a singleton object which is shared between threads.
75 * Access to this dictionary must be surrounded with a mutex.
77 static struct attr_hashmap g_attr_hashmap = {
78 .map = HASHMAP_INIT(attr_hash_entry_cmp, NULL),
82 * Retrieve the 'value' stored in a hashmap given the provided 'key'.
83 * If there is no matching entry, return NULL.
85 static void *attr_hashmap_get(struct attr_hashmap *map,
86 const char *key, size_t keylen)
88 struct attr_hash_entry k;
89 struct attr_hash_entry *e;
91 hashmap_entry_init(&k.ent, memhash(key, keylen));
92 k.key = key;
93 k.keylen = keylen;
94 e = hashmap_get_entry(&map->map, &k, ent, NULL);
96 return e ? e->value : NULL;
99 /* Add 'value' to a hashmap based on the provided 'key'. */
100 static void attr_hashmap_add(struct attr_hashmap *map,
101 const char *key, size_t keylen,
102 void *value)
104 struct attr_hash_entry *e;
106 e = xmalloc(sizeof(struct attr_hash_entry));
107 hashmap_entry_init(&e->ent, memhash(key, keylen));
108 e->key = key;
109 e->keylen = keylen;
110 e->value = value;
112 hashmap_add(&map->map, &e->ent);
115 struct all_attrs_item {
116 const struct git_attr *attr;
117 const char *value;
119 * If 'macro' is non-NULL, indicates that 'attr' is a macro based on
120 * the current attribute stack and contains a pointer to the match_attr
121 * definition of the macro
123 const struct match_attr *macro;
127 * Reallocate and reinitialize the array of all attributes (which is used in
128 * the attribute collection process) in 'check' based on the global dictionary
129 * of attributes.
131 static void all_attrs_init(struct attr_hashmap *map, struct attr_check *check)
133 int i;
134 unsigned int size;
136 hashmap_lock(map);
138 size = hashmap_get_size(&map->map);
139 if (size < check->all_attrs_nr)
140 BUG("interned attributes shouldn't be deleted");
143 * If the number of attributes in the global dictionary has increased
144 * (or this attr_check instance doesn't have an initialized all_attrs
145 * field), reallocate the provided attr_check instance's all_attrs
146 * field and fill each entry with its corresponding git_attr.
148 if (size != check->all_attrs_nr) {
149 struct attr_hash_entry *e;
150 struct hashmap_iter iter;
152 REALLOC_ARRAY(check->all_attrs, size);
153 check->all_attrs_nr = size;
155 hashmap_for_each_entry(&map->map, &iter, e,
156 ent /* member name */) {
157 const struct git_attr *a = e->value;
158 check->all_attrs[a->attr_nr].attr = a;
162 hashmap_unlock(map);
165 * Re-initialize every entry in check->all_attrs.
166 * This re-initialization can live outside of the locked region since
167 * the attribute dictionary is no longer being accessed.
169 for (i = 0; i < check->all_attrs_nr; i++) {
170 check->all_attrs[i].value = ATTR__UNKNOWN;
171 check->all_attrs[i].macro = NULL;
175 static int attr_name_valid(const char *name, size_t namelen)
178 * Attribute name cannot begin with '-' and must consist of
179 * characters from [-A-Za-z0-9_.].
181 if (namelen <= 0 || *name == '-')
182 return 0;
183 while (namelen--) {
184 char ch = *name++;
185 if (! (ch == '-' || ch == '.' || ch == '_' ||
186 ('0' <= ch && ch <= '9') ||
187 ('a' <= ch && ch <= 'z') ||
188 ('A' <= ch && ch <= 'Z')) )
189 return 0;
191 return 1;
194 static void report_invalid_attr(const char *name, size_t len,
195 const char *src, int lineno)
197 struct strbuf err = STRBUF_INIT;
198 strbuf_addf(&err, _("%.*s is not a valid attribute name"),
199 (int) len, name);
200 fprintf(stderr, "%s: %s:%d\n", err.buf, src, lineno);
201 strbuf_release(&err);
205 * Given a 'name', lookup and return the corresponding attribute in the global
206 * dictionary. If no entry is found, create a new attribute and store it in
207 * the dictionary.
209 static const struct git_attr *git_attr_internal(const char *name, size_t namelen)
211 struct git_attr *a;
213 if (!attr_name_valid(name, namelen))
214 return NULL;
216 hashmap_lock(&g_attr_hashmap);
218 a = attr_hashmap_get(&g_attr_hashmap, name, namelen);
220 if (!a) {
221 FLEX_ALLOC_MEM(a, name, name, namelen);
222 a->attr_nr = hashmap_get_size(&g_attr_hashmap.map);
224 attr_hashmap_add(&g_attr_hashmap, a->name, namelen, a);
225 if (a->attr_nr != hashmap_get_size(&g_attr_hashmap.map) - 1)
226 die(_("unable to add additional attribute"));
229 hashmap_unlock(&g_attr_hashmap);
231 return a;
234 const struct git_attr *git_attr(const char *name)
236 return git_attr_internal(name, strlen(name));
239 /* What does a matched pattern decide? */
240 struct attr_state {
241 const struct git_attr *attr;
242 const char *setto;
245 struct pattern {
246 const char *pattern;
247 int patternlen;
248 int nowildcardlen;
249 unsigned flags; /* PATTERN_FLAG_* */
253 * One rule, as from a .gitattributes file.
255 * If is_macro is true, then u.attr is a pointer to the git_attr being
256 * defined.
258 * If is_macro is false, then u.pat is the filename pattern to which the
259 * rule applies.
261 * In either case, num_attr is the number of attributes affected by
262 * this rule, and state is an array listing them. The attributes are
263 * listed as they appear in the file (macros unexpanded).
265 struct match_attr {
266 union {
267 struct pattern pat;
268 const struct git_attr *attr;
269 } u;
270 char is_macro;
271 size_t num_attr;
272 struct attr_state state[FLEX_ARRAY];
275 static const char blank[] = " \t\r\n";
277 /* Flags usable in read_attr() and parse_attr_line() family of functions. */
278 #define READ_ATTR_MACRO_OK (1<<0)
279 #define READ_ATTR_NOFOLLOW (1<<1)
282 * Parse a whitespace-delimited attribute state (i.e., "attr",
283 * "-attr", "!attr", or "attr=value") from the string starting at src.
284 * If e is not NULL, write the results to *e. Return a pointer to the
285 * remainder of the string (with leading whitespace removed), or NULL
286 * if there was an error.
288 static const char *parse_attr(const char *src, int lineno, const char *cp,
289 struct attr_state *e)
291 const char *ep, *equals;
292 size_t len;
294 ep = cp + strcspn(cp, blank);
295 equals = strchr(cp, '=');
296 if (equals && ep < equals)
297 equals = NULL;
298 if (equals)
299 len = equals - cp;
300 else
301 len = ep - cp;
302 if (!e) {
303 if (*cp == '-' || *cp == '!') {
304 cp++;
305 len--;
307 if (!attr_name_valid(cp, len)) {
308 report_invalid_attr(cp, len, src, lineno);
309 return NULL;
311 } else {
313 * As this function is always called twice, once with
314 * e == NULL in the first pass and then e != NULL in
315 * the second pass, no need for attr_name_valid()
316 * check here.
318 if (*cp == '-' || *cp == '!') {
319 e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
320 cp++;
321 len--;
323 else if (!equals)
324 e->setto = ATTR__TRUE;
325 else {
326 e->setto = xmemdupz(equals + 1, ep - equals - 1);
328 e->attr = git_attr_internal(cp, len);
330 return ep + strspn(ep, blank);
333 static struct match_attr *parse_attr_line(const char *line, const char *src,
334 int lineno, unsigned flags)
336 size_t namelen, num_attr, i;
337 const char *cp, *name, *states;
338 struct match_attr *res = NULL;
339 int is_macro;
340 struct strbuf pattern = STRBUF_INIT;
342 cp = line + strspn(line, blank);
343 if (!*cp || *cp == '#')
344 return NULL;
345 name = cp;
347 if (strlen(line) >= ATTR_MAX_LINE_LENGTH) {
348 warning(_("ignoring overly long attributes line %d"), lineno);
349 return NULL;
352 if (*cp == '"' && !unquote_c_style(&pattern, name, &states)) {
353 name = pattern.buf;
354 namelen = pattern.len;
355 } else {
356 namelen = strcspn(name, blank);
357 states = name + namelen;
360 if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
361 starts_with(name, ATTRIBUTE_MACRO_PREFIX)) {
362 if (!(flags & READ_ATTR_MACRO_OK)) {
363 fprintf_ln(stderr, _("%s not allowed: %s:%d"),
364 name, src, lineno);
365 goto fail_return;
367 is_macro = 1;
368 name += strlen(ATTRIBUTE_MACRO_PREFIX);
369 name += strspn(name, blank);
370 namelen = strcspn(name, blank);
371 if (!attr_name_valid(name, namelen)) {
372 report_invalid_attr(name, namelen, src, lineno);
373 goto fail_return;
376 else
377 is_macro = 0;
379 states += strspn(states, blank);
381 /* First pass to count the attr_states */
382 for (cp = states, num_attr = 0; *cp; num_attr++) {
383 cp = parse_attr(src, lineno, cp, NULL);
384 if (!cp)
385 goto fail_return;
388 res = xcalloc(1, st_add3(sizeof(*res),
389 st_mult(sizeof(struct attr_state), num_attr),
390 is_macro ? 0 : namelen + 1));
391 if (is_macro) {
392 res->u.attr = git_attr_internal(name, namelen);
393 } else {
394 char *p = (char *)&(res->state[num_attr]);
395 memcpy(p, name, namelen);
396 res->u.pat.pattern = p;
397 parse_path_pattern(&res->u.pat.pattern,
398 &res->u.pat.patternlen,
399 &res->u.pat.flags,
400 &res->u.pat.nowildcardlen);
401 if (res->u.pat.flags & PATTERN_FLAG_NEGATIVE) {
402 warning(_("Negative patterns are ignored in git attributes\n"
403 "Use '\\!' for literal leading exclamation."));
404 goto fail_return;
407 res->is_macro = is_macro;
408 res->num_attr = num_attr;
410 /* Second pass to fill the attr_states */
411 for (cp = states, i = 0; *cp; i++) {
412 cp = parse_attr(src, lineno, cp, &(res->state[i]));
415 strbuf_release(&pattern);
416 return res;
418 fail_return:
419 strbuf_release(&pattern);
420 free(res);
421 return NULL;
425 * Like info/exclude and .gitignore, the attribute information can
426 * come from many places.
428 * (1) .gitattributes file of the same directory;
429 * (2) .gitattributes file of the parent directory if (1) does not have
430 * any match; this goes recursively upwards, just like .gitignore.
431 * (3) $GIT_DIR/info/attributes, which overrides both of the above.
433 * In the same file, later entries override the earlier match, so in the
434 * global list, we would have entries from info/attributes the earliest
435 * (reading the file from top to bottom), .gitattributes of the root
436 * directory (again, reading the file from top to bottom) down to the
437 * current directory, and then scan the list backwards to find the first match.
438 * This is exactly the same as what is_excluded() does in dir.c to deal with
439 * .gitignore file and info/excludes file as a fallback.
442 struct attr_stack {
443 struct attr_stack *prev;
444 char *origin;
445 size_t originlen;
446 unsigned num_matches;
447 unsigned alloc;
448 struct match_attr **attrs;
451 static void attr_stack_free(struct attr_stack *e)
453 unsigned i;
454 free(e->origin);
455 for (i = 0; i < e->num_matches; i++) {
456 struct match_attr *a = e->attrs[i];
457 size_t j;
459 for (j = 0; j < a->num_attr; j++) {
460 const char *setto = a->state[j].setto;
461 if (setto == ATTR__TRUE ||
462 setto == ATTR__FALSE ||
463 setto == ATTR__UNSET ||
464 setto == ATTR__UNKNOWN)
466 else
467 free((char *) setto);
469 free(a);
471 free(e->attrs);
472 free(e);
475 static void drop_attr_stack(struct attr_stack **stack)
477 while (*stack) {
478 struct attr_stack *elem = *stack;
479 *stack = elem->prev;
480 attr_stack_free(elem);
484 /* List of all attr_check structs; access should be surrounded by mutex */
485 static struct check_vector {
486 size_t nr;
487 size_t alloc;
488 struct attr_check **checks;
489 pthread_mutex_t mutex;
490 } check_vector;
492 static inline void vector_lock(void)
494 pthread_mutex_lock(&check_vector.mutex);
497 static inline void vector_unlock(void)
499 pthread_mutex_unlock(&check_vector.mutex);
502 static void check_vector_add(struct attr_check *c)
504 vector_lock();
506 ALLOC_GROW(check_vector.checks,
507 check_vector.nr + 1,
508 check_vector.alloc);
509 check_vector.checks[check_vector.nr++] = c;
511 vector_unlock();
514 static void check_vector_remove(struct attr_check *check)
516 int i;
518 vector_lock();
520 /* Find entry */
521 for (i = 0; i < check_vector.nr; i++)
522 if (check_vector.checks[i] == check)
523 break;
525 if (i >= check_vector.nr)
526 BUG("no entry found");
528 /* shift entries over */
529 for (; i < check_vector.nr - 1; i++)
530 check_vector.checks[i] = check_vector.checks[i + 1];
532 check_vector.nr--;
534 vector_unlock();
537 /* Iterate through all attr_check instances and drop their stacks */
538 static void drop_all_attr_stacks(void)
540 int i;
542 vector_lock();
544 for (i = 0; i < check_vector.nr; i++) {
545 drop_attr_stack(&check_vector.checks[i]->stack);
548 vector_unlock();
551 struct attr_check *attr_check_alloc(void)
553 struct attr_check *c = xcalloc(1, sizeof(struct attr_check));
555 /* save pointer to the check struct */
556 check_vector_add(c);
558 return c;
561 struct attr_check *attr_check_initl(const char *one, ...)
563 struct attr_check *check;
564 int cnt;
565 va_list params;
566 const char *param;
568 va_start(params, one);
569 for (cnt = 1; (param = va_arg(params, const char *)) != NULL; cnt++)
571 va_end(params);
573 check = attr_check_alloc();
574 check->nr = cnt;
575 check->alloc = cnt;
576 CALLOC_ARRAY(check->items, cnt);
578 check->items[0].attr = git_attr(one);
579 va_start(params, one);
580 for (cnt = 1; cnt < check->nr; cnt++) {
581 const struct git_attr *attr;
582 param = va_arg(params, const char *);
583 if (!param)
584 BUG("counted %d != ended at %d",
585 check->nr, cnt);
586 attr = git_attr(param);
587 if (!attr)
588 BUG("%s: not a valid attribute name", param);
589 check->items[cnt].attr = attr;
591 va_end(params);
592 return check;
595 struct attr_check *attr_check_dup(const struct attr_check *check)
597 struct attr_check *ret;
599 if (!check)
600 return NULL;
602 ret = attr_check_alloc();
604 ret->nr = check->nr;
605 ret->alloc = check->alloc;
606 DUP_ARRAY(ret->items, check->items, ret->nr);
608 return ret;
611 struct attr_check_item *attr_check_append(struct attr_check *check,
612 const struct git_attr *attr)
614 struct attr_check_item *item;
616 ALLOC_GROW(check->items, check->nr + 1, check->alloc);
617 item = &check->items[check->nr++];
618 item->attr = attr;
619 return item;
622 void attr_check_reset(struct attr_check *check)
624 check->nr = 0;
627 void attr_check_clear(struct attr_check *check)
629 FREE_AND_NULL(check->items);
630 check->alloc = 0;
631 check->nr = 0;
633 FREE_AND_NULL(check->all_attrs);
634 check->all_attrs_nr = 0;
636 drop_attr_stack(&check->stack);
639 void attr_check_free(struct attr_check *check)
641 if (check) {
642 /* Remove check from the check vector */
643 check_vector_remove(check);
645 attr_check_clear(check);
646 free(check);
650 static const char *builtin_attr[] = {
651 "[attr]binary -diff -merge -text",
652 NULL,
655 static void handle_attr_line(struct attr_stack *res,
656 const char *line,
657 const char *src,
658 int lineno,
659 unsigned flags)
661 struct match_attr *a;
663 a = parse_attr_line(line, src, lineno, flags);
664 if (!a)
665 return;
666 ALLOC_GROW_BY(res->attrs, res->num_matches, 1, res->alloc);
667 res->attrs[res->num_matches - 1] = a;
670 static struct attr_stack *read_attr_from_array(const char **list)
672 struct attr_stack *res;
673 const char *line;
674 int lineno = 0;
676 CALLOC_ARRAY(res, 1);
677 while ((line = *(list++)) != NULL)
678 handle_attr_line(res, line, "[builtin]", ++lineno,
679 READ_ATTR_MACRO_OK);
680 return res;
684 * Callers into the attribute system assume there is a single, system-wide
685 * global state where attributes are read from and when the state is flipped by
686 * calling git_attr_set_direction(), the stack frames that have been
687 * constructed need to be discarded so that subsequent calls into the
688 * attribute system will lazily read from the right place. Since changing
689 * direction causes a global paradigm shift, it should not ever be called while
690 * another thread could potentially be calling into the attribute system.
692 static enum git_attr_direction direction;
694 void git_attr_set_direction(enum git_attr_direction new_direction)
696 if (is_bare_repository() && new_direction != GIT_ATTR_INDEX)
697 BUG("non-INDEX attr direction in a bare repo");
699 if (new_direction != direction)
700 drop_all_attr_stacks();
702 direction = new_direction;
705 static struct attr_stack *read_attr_from_file(const char *path, unsigned flags)
707 struct strbuf buf = STRBUF_INIT;
708 int fd;
709 FILE *fp;
710 struct attr_stack *res;
711 int lineno = 0;
712 struct stat st;
714 if (flags & READ_ATTR_NOFOLLOW)
715 fd = open_nofollow(path, O_RDONLY);
716 else
717 fd = open(path, O_RDONLY);
719 if (fd < 0) {
720 warn_on_fopen_errors(path);
721 return NULL;
723 fp = xfdopen(fd, "r");
724 if (fstat(fd, &st)) {
725 warning_errno(_("cannot fstat gitattributes file '%s'"), path);
726 fclose(fp);
727 return NULL;
729 if (st.st_size >= ATTR_MAX_FILE_SIZE) {
730 warning(_("ignoring overly large gitattributes file '%s'"), path);
731 fclose(fp);
732 return NULL;
735 CALLOC_ARRAY(res, 1);
736 while (strbuf_getline(&buf, fp) != EOF) {
737 if (!lineno && starts_with(buf.buf, utf8_bom))
738 strbuf_remove(&buf, 0, strlen(utf8_bom));
739 handle_attr_line(res, buf.buf, path, ++lineno, flags);
742 fclose(fp);
743 strbuf_release(&buf);
744 return res;
747 static struct attr_stack *read_attr_from_index(struct index_state *istate,
748 const char *path,
749 unsigned flags)
751 struct attr_stack *res;
752 char *buf, *sp;
753 int lineno = 0;
754 unsigned long size;
756 if (!istate)
757 return NULL;
760 * The .gitattributes file only applies to files within its
761 * parent directory. In the case of cone-mode sparse-checkout,
762 * the .gitattributes file is sparse if and only if all paths
763 * within that directory are also sparse. Thus, don't load the
764 * .gitattributes file since it will not matter.
766 * In the case of a sparse index, it is critical that we don't go
767 * looking for a .gitattributes file, as doing so would cause the
768 * index to expand.
770 if (!path_in_cone_mode_sparse_checkout(path, istate))
771 return NULL;
773 buf = read_blob_data_from_index(istate, path, &size);
774 if (!buf)
775 return NULL;
776 if (size >= ATTR_MAX_FILE_SIZE) {
777 warning(_("ignoring overly large gitattributes blob '%s'"), path);
778 return NULL;
781 CALLOC_ARRAY(res, 1);
782 for (sp = buf; *sp; ) {
783 char *ep;
784 int more;
786 ep = strchrnul(sp, '\n');
787 more = (*ep == '\n');
788 *ep = '\0';
789 handle_attr_line(res, sp, path, ++lineno, flags);
790 sp = ep + more;
792 free(buf);
793 return res;
796 static struct attr_stack *read_attr(struct index_state *istate,
797 const char *path, unsigned flags)
799 struct attr_stack *res = NULL;
801 if (direction == GIT_ATTR_INDEX) {
802 res = read_attr_from_index(istate, path, flags);
803 } else if (!is_bare_repository()) {
804 if (direction == GIT_ATTR_CHECKOUT) {
805 res = read_attr_from_index(istate, path, flags);
806 if (!res)
807 res = read_attr_from_file(path, flags);
808 } else if (direction == GIT_ATTR_CHECKIN) {
809 res = read_attr_from_file(path, flags);
810 if (!res)
812 * There is no checked out .gitattributes file
813 * there, but we might have it in the index.
814 * We allow operation in a sparsely checked out
815 * work tree, so read from it.
817 res = read_attr_from_index(istate, path, flags);
821 if (!res)
822 CALLOC_ARRAY(res, 1);
823 return res;
826 static const char *git_etc_gitattributes(void)
828 static const char *system_wide;
829 if (!system_wide)
830 system_wide = system_path(ETC_GITATTRIBUTES);
831 return system_wide;
834 static const char *get_home_gitattributes(void)
836 if (!git_attributes_file)
837 git_attributes_file = xdg_config_home("attributes");
839 return git_attributes_file;
842 static int git_attr_system(void)
844 return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
847 static GIT_PATH_FUNC(git_path_info_attributes, INFOATTRIBUTES_FILE)
849 static void push_stack(struct attr_stack **attr_stack_p,
850 struct attr_stack *elem, char *origin, size_t originlen)
852 if (elem) {
853 elem->origin = origin;
854 if (origin)
855 elem->originlen = originlen;
856 elem->prev = *attr_stack_p;
857 *attr_stack_p = elem;
861 static void bootstrap_attr_stack(struct index_state *istate,
862 struct attr_stack **stack)
864 struct attr_stack *e;
865 unsigned flags = READ_ATTR_MACRO_OK;
867 if (*stack)
868 return;
870 /* builtin frame */
871 e = read_attr_from_array(builtin_attr);
872 push_stack(stack, e, NULL, 0);
874 /* system-wide frame */
875 if (git_attr_system()) {
876 e = read_attr_from_file(git_etc_gitattributes(), flags);
877 push_stack(stack, e, NULL, 0);
880 /* home directory */
881 if (get_home_gitattributes()) {
882 e = read_attr_from_file(get_home_gitattributes(), flags);
883 push_stack(stack, e, NULL, 0);
886 /* root directory */
887 e = read_attr(istate, GITATTRIBUTES_FILE, flags | READ_ATTR_NOFOLLOW);
888 push_stack(stack, e, xstrdup(""), 0);
890 /* info frame */
891 if (startup_info->have_repository)
892 e = read_attr_from_file(git_path_info_attributes(), flags);
893 else
894 e = NULL;
895 if (!e)
896 CALLOC_ARRAY(e, 1);
897 push_stack(stack, e, NULL, 0);
900 static void prepare_attr_stack(struct index_state *istate,
901 const char *path, int dirlen,
902 struct attr_stack **stack)
904 struct attr_stack *info;
905 struct strbuf pathbuf = STRBUF_INIT;
908 * At the bottom of the attribute stack is the built-in
909 * set of attribute definitions, followed by the contents
910 * of $(prefix)/etc/gitattributes and a file specified by
911 * core.attributesfile. Then, contents from
912 * .gitattributes files from directories closer to the
913 * root to the ones in deeper directories are pushed
914 * to the stack. Finally, at the very top of the stack
915 * we always keep the contents of $GIT_DIR/info/attributes.
917 * When checking, we use entries from near the top of the
918 * stack, preferring $GIT_DIR/info/attributes, then
919 * .gitattributes in deeper directories to shallower ones,
920 * and finally use the built-in set as the default.
922 bootstrap_attr_stack(istate, stack);
925 * Pop the "info" one that is always at the top of the stack.
927 info = *stack;
928 *stack = info->prev;
931 * Pop the ones from directories that are not the prefix of
932 * the path we are checking. Break out of the loop when we see
933 * the root one (whose origin is an empty string "") or the builtin
934 * one (whose origin is NULL) without popping it.
936 while ((*stack)->origin) {
937 int namelen = (*stack)->originlen;
938 struct attr_stack *elem;
940 elem = *stack;
941 if (namelen <= dirlen &&
942 !strncmp(elem->origin, path, namelen) &&
943 (!namelen || path[namelen] == '/'))
944 break;
946 *stack = elem->prev;
947 attr_stack_free(elem);
951 * bootstrap_attr_stack() should have added, and the
952 * above loop should have stopped before popping, the
953 * root element whose attr_stack->origin is set to an
954 * empty string.
956 assert((*stack)->origin);
958 strbuf_addstr(&pathbuf, (*stack)->origin);
959 /* Build up to the directory 'path' is in */
960 while (pathbuf.len < dirlen) {
961 size_t len = pathbuf.len;
962 struct attr_stack *next;
963 char *origin;
965 /* Skip path-separator */
966 if (len < dirlen && is_dir_sep(path[len]))
967 len++;
968 /* Find the end of the next component */
969 while (len < dirlen && !is_dir_sep(path[len]))
970 len++;
972 if (pathbuf.len > 0)
973 strbuf_addch(&pathbuf, '/');
974 strbuf_add(&pathbuf, path + pathbuf.len, (len - pathbuf.len));
975 strbuf_addf(&pathbuf, "/%s", GITATTRIBUTES_FILE);
977 next = read_attr(istate, pathbuf.buf, READ_ATTR_NOFOLLOW);
979 /* reset the pathbuf to not include "/.gitattributes" */
980 strbuf_setlen(&pathbuf, len);
982 origin = xstrdup(pathbuf.buf);
983 push_stack(stack, next, origin, len);
987 * Finally push the "info" one at the top of the stack.
989 push_stack(stack, info, NULL, 0);
991 strbuf_release(&pathbuf);
994 static int path_matches(const char *pathname, int pathlen,
995 int basename_offset,
996 const struct pattern *pat,
997 const char *base, int baselen)
999 const char *pattern = pat->pattern;
1000 int prefix = pat->nowildcardlen;
1001 int isdir = (pathlen && pathname[pathlen - 1] == '/');
1003 if ((pat->flags & PATTERN_FLAG_MUSTBEDIR) && !isdir)
1004 return 0;
1006 if (pat->flags & PATTERN_FLAG_NODIR) {
1007 return match_basename(pathname + basename_offset,
1008 pathlen - basename_offset - isdir,
1009 pattern, prefix,
1010 pat->patternlen, pat->flags);
1012 return match_pathname(pathname, pathlen - isdir,
1013 base, baselen,
1014 pattern, prefix, pat->patternlen);
1017 static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem);
1019 static int fill_one(struct all_attrs_item *all_attrs,
1020 const struct match_attr *a, int rem)
1022 size_t i;
1024 for (i = a->num_attr; rem > 0 && i > 0; i--) {
1025 const struct git_attr *attr = a->state[i - 1].attr;
1026 const char **n = &(all_attrs[attr->attr_nr].value);
1027 const char *v = a->state[i - 1].setto;
1029 if (*n == ATTR__UNKNOWN) {
1030 *n = v;
1031 rem--;
1032 rem = macroexpand_one(all_attrs, attr->attr_nr, rem);
1035 return rem;
1038 static int fill(const char *path, int pathlen, int basename_offset,
1039 const struct attr_stack *stack,
1040 struct all_attrs_item *all_attrs, int rem)
1042 for (; rem > 0 && stack; stack = stack->prev) {
1043 unsigned i;
1044 const char *base = stack->origin ? stack->origin : "";
1046 for (i = stack->num_matches; 0 < rem && 0 < i; i--) {
1047 const struct match_attr *a = stack->attrs[i - 1];
1048 if (a->is_macro)
1049 continue;
1050 if (path_matches(path, pathlen, basename_offset,
1051 &a->u.pat, base, stack->originlen))
1052 rem = fill_one(all_attrs, a, rem);
1056 return rem;
1059 static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem)
1061 const struct all_attrs_item *item = &all_attrs[nr];
1063 if (item->macro && item->value == ATTR__TRUE)
1064 return fill_one(all_attrs, item->macro, rem);
1065 else
1066 return rem;
1070 * Marks the attributes which are macros based on the attribute stack.
1071 * This prevents having to search through the attribute stack each time
1072 * a macro needs to be expanded during the fill stage.
1074 static void determine_macros(struct all_attrs_item *all_attrs,
1075 const struct attr_stack *stack)
1077 for (; stack; stack = stack->prev) {
1078 unsigned i;
1079 for (i = stack->num_matches; i > 0; i--) {
1080 const struct match_attr *ma = stack->attrs[i - 1];
1081 if (ma->is_macro) {
1082 unsigned int n = ma->u.attr->attr_nr;
1083 if (!all_attrs[n].macro) {
1084 all_attrs[n].macro = ma;
1092 * Collect attributes for path into the array pointed to by check->all_attrs.
1093 * If check->check_nr is non-zero, only attributes in check[] are collected.
1094 * Otherwise all attributes are collected.
1096 static void collect_some_attrs(struct index_state *istate,
1097 const char *path,
1098 struct attr_check *check)
1100 int pathlen, rem, dirlen;
1101 const char *cp, *last_slash = NULL;
1102 int basename_offset;
1104 for (cp = path; *cp; cp++) {
1105 if (*cp == '/' && cp[1])
1106 last_slash = cp;
1108 pathlen = cp - path;
1109 if (last_slash) {
1110 basename_offset = last_slash + 1 - path;
1111 dirlen = last_slash - path;
1112 } else {
1113 basename_offset = 0;
1114 dirlen = 0;
1117 prepare_attr_stack(istate, path, dirlen, &check->stack);
1118 all_attrs_init(&g_attr_hashmap, check);
1119 determine_macros(check->all_attrs, check->stack);
1121 rem = check->all_attrs_nr;
1122 fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
1125 void git_check_attr(struct index_state *istate,
1126 const char *path,
1127 struct attr_check *check)
1129 int i;
1131 collect_some_attrs(istate, path, check);
1133 for (i = 0; i < check->nr; i++) {
1134 unsigned int n = check->items[i].attr->attr_nr;
1135 const char *value = check->all_attrs[n].value;
1136 if (value == ATTR__UNKNOWN)
1137 value = ATTR__UNSET;
1138 check->items[i].value = value;
1142 void git_all_attrs(struct index_state *istate,
1143 const char *path, struct attr_check *check)
1145 int i;
1147 attr_check_reset(check);
1148 collect_some_attrs(istate, path, check);
1150 for (i = 0; i < check->all_attrs_nr; i++) {
1151 const char *name = check->all_attrs[i].attr->name;
1152 const char *value = check->all_attrs[i].value;
1153 struct attr_check_item *item;
1154 if (value == ATTR__UNSET || value == ATTR__UNKNOWN)
1155 continue;
1156 item = attr_check_append(check, git_attr(name));
1157 item->value = value;
1161 void attr_start(void)
1163 pthread_mutex_init(&g_attr_hashmap.mutex, NULL);
1164 pthread_mutex_init(&check_vector.mutex, NULL);