git/attr.c
Junio C Hamano 26dd307cfa Merge branch 'jc/attr-tree-config'
The attribute subsystem learned to honor `attr.tree` configuration
that specifies which tree to read the .gitattributes files from.

* jc/attr-tree-config:
  attr: add attr.tree for setting the treeish to read attributes from
  attr: read attributes from HEAD when bare repo
2023-10-30 07:09:55 +09:00

1286 lines
32 KiB
C

/*
* Handle git attributes. See gitattributes(5) for a description of
* the file syntax, and attr.h for a description of the API.
*
* One basic design decision here is that we are not going to support
* an insanely large number of attributes.
*/
#include "git-compat-util.h"
#include "config.h"
#include "environment.h"
#include "exec-cmd.h"
#include "attr.h"
#include "dir.h"
#include "gettext.h"
#include "path.h"
#include "utf8.h"
#include "quote.h"
#include "read-cache-ll.h"
#include "revision.h"
#include "object-store-ll.h"
#include "setup.h"
#include "thread-utils.h"
#include "tree-walk.h"
#include "object-name.h"
const char *git_attr_tree;
const char git_attr__true[] = "(builtin)true";
const char git_attr__false[] = "\0(builtin)false";
static const char git_attr__unknown[] = "(builtin)unknown";
#define ATTR__TRUE git_attr__true
#define ATTR__FALSE git_attr__false
#define ATTR__UNSET NULL
#define ATTR__UNKNOWN git_attr__unknown
struct git_attr {
unsigned int attr_nr; /* unique attribute number */
char name[FLEX_ARRAY]; /* attribute name */
};
const char *git_attr_name(const struct git_attr *attr)
{
return attr->name;
}
struct attr_hashmap {
struct hashmap map;
pthread_mutex_t mutex;
};
static inline void hashmap_lock(struct attr_hashmap *map)
{
pthread_mutex_lock(&map->mutex);
}
static inline void hashmap_unlock(struct attr_hashmap *map)
{
pthread_mutex_unlock(&map->mutex);
}
/* The container for objects stored in "struct attr_hashmap" */
struct attr_hash_entry {
struct hashmap_entry ent;
const char *key; /* the key; memory should be owned by value */
size_t keylen; /* length of the key */
void *value; /* the stored value */
};
/* attr_hashmap comparison function */
static int attr_hash_entry_cmp(const void *cmp_data UNUSED,
const struct hashmap_entry *eptr,
const struct hashmap_entry *entry_or_key,
const void *keydata UNUSED)
{
const struct attr_hash_entry *a, *b;
a = container_of(eptr, const struct attr_hash_entry, ent);
b = container_of(entry_or_key, const struct attr_hash_entry, ent);
return (a->keylen != b->keylen) || strncmp(a->key, b->key, a->keylen);
}
/*
* The global dictionary of all interned attributes. This
* is a singleton object which is shared between threads.
* Access to this dictionary must be surrounded with a mutex.
*/
static struct attr_hashmap g_attr_hashmap = {
.map = HASHMAP_INIT(attr_hash_entry_cmp, NULL),
};
/*
* Retrieve the 'value' stored in a hashmap given the provided 'key'.
* If there is no matching entry, return NULL.
*/
static void *attr_hashmap_get(struct attr_hashmap *map,
const char *key, size_t keylen)
{
struct attr_hash_entry k;
struct attr_hash_entry *e;
hashmap_entry_init(&k.ent, memhash(key, keylen));
k.key = key;
k.keylen = keylen;
e = hashmap_get_entry(&map->map, &k, ent, NULL);
return e ? e->value : NULL;
}
/* Add 'value' to a hashmap based on the provided 'key'. */
static void attr_hashmap_add(struct attr_hashmap *map,
const char *key, size_t keylen,
void *value)
{
struct attr_hash_entry *e;
e = xmalloc(sizeof(struct attr_hash_entry));
hashmap_entry_init(&e->ent, memhash(key, keylen));
e->key = key;
e->keylen = keylen;
e->value = value;
hashmap_add(&map->map, &e->ent);
}
struct all_attrs_item {
const struct git_attr *attr;
const char *value;
/*
* If 'macro' is non-NULL, indicates that 'attr' is a macro based on
* the current attribute stack and contains a pointer to the match_attr
* definition of the macro
*/
const struct match_attr *macro;
};
/*
* Reallocate and reinitialize the array of all attributes (which is used in
* the attribute collection process) in 'check' based on the global dictionary
* of attributes.
*/
static void all_attrs_init(struct attr_hashmap *map, struct attr_check *check)
{
int i;
unsigned int size;
hashmap_lock(map);
size = hashmap_get_size(&map->map);
if (size < check->all_attrs_nr)
BUG("interned attributes shouldn't be deleted");
/*
* If the number of attributes in the global dictionary has increased
* (or this attr_check instance doesn't have an initialized all_attrs
* field), reallocate the provided attr_check instance's all_attrs
* field and fill each entry with its corresponding git_attr.
*/
if (size != check->all_attrs_nr) {
struct attr_hash_entry *e;
struct hashmap_iter iter;
REALLOC_ARRAY(check->all_attrs, size);
check->all_attrs_nr = size;
hashmap_for_each_entry(&map->map, &iter, e,
ent /* member name */) {
const struct git_attr *a = e->value;
check->all_attrs[a->attr_nr].attr = a;
}
}
hashmap_unlock(map);
/*
* Re-initialize every entry in check->all_attrs.
* This re-initialization can live outside of the locked region since
* the attribute dictionary is no longer being accessed.
*/
for (i = 0; i < check->all_attrs_nr; i++) {
check->all_attrs[i].value = ATTR__UNKNOWN;
check->all_attrs[i].macro = NULL;
}
}
static int attr_name_valid(const char *name, size_t namelen)
{
/*
* Attribute name cannot begin with '-' and must consist of
* characters from [-A-Za-z0-9_.].
*/
if (namelen <= 0 || *name == '-')
return 0;
while (namelen--) {
char ch = *name++;
if (! (ch == '-' || ch == '.' || ch == '_' ||
('0' <= ch && ch <= '9') ||
('a' <= ch && ch <= 'z') ||
('A' <= ch && ch <= 'Z')) )
return 0;
}
return 1;
}
static void report_invalid_attr(const char *name, size_t len,
const char *src, int lineno)
{
struct strbuf err = STRBUF_INIT;
strbuf_addf(&err, _("%.*s is not a valid attribute name"),
(int) len, name);
fprintf(stderr, "%s: %s:%d\n", err.buf, src, lineno);
strbuf_release(&err);
}
/*
* Given a 'name', lookup and return the corresponding attribute in the global
* dictionary. If no entry is found, create a new attribute and store it in
* the dictionary.
*/
static const struct git_attr *git_attr_internal(const char *name, size_t namelen)
{
struct git_attr *a;
if (!attr_name_valid(name, namelen))
return NULL;
hashmap_lock(&g_attr_hashmap);
a = attr_hashmap_get(&g_attr_hashmap, name, namelen);
if (!a) {
FLEX_ALLOC_MEM(a, name, name, namelen);
a->attr_nr = hashmap_get_size(&g_attr_hashmap.map);
attr_hashmap_add(&g_attr_hashmap, a->name, namelen, a);
if (a->attr_nr != hashmap_get_size(&g_attr_hashmap.map) - 1)
die(_("unable to add additional attribute"));
}
hashmap_unlock(&g_attr_hashmap);
return a;
}
const struct git_attr *git_attr(const char *name)
{
return git_attr_internal(name, strlen(name));
}
/* What does a matched pattern decide? */
struct attr_state {
const struct git_attr *attr;
const char *setto;
};
struct pattern {
const char *pattern;
int patternlen;
int nowildcardlen;
unsigned flags; /* PATTERN_FLAG_* */
};
/*
* One rule, as from a .gitattributes file.
*
* If is_macro is true, then u.attr is a pointer to the git_attr being
* defined.
*
* If is_macro is false, then u.pat is the filename pattern to which the
* rule applies.
*
* In either case, num_attr is the number of attributes affected by
* this rule, and state is an array listing them. The attributes are
* listed as they appear in the file (macros unexpanded).
*/
struct match_attr {
union {
struct pattern pat;
const struct git_attr *attr;
} u;
char is_macro;
size_t num_attr;
struct attr_state state[FLEX_ARRAY];
};
static const char blank[] = " \t\r\n";
/* Flags usable in read_attr() and parse_attr_line() family of functions. */
#define READ_ATTR_MACRO_OK (1<<0)
#define READ_ATTR_NOFOLLOW (1<<1)
/*
* Parse a whitespace-delimited attribute state (i.e., "attr",
* "-attr", "!attr", or "attr=value") from the string starting at src.
* If e is not NULL, write the results to *e. Return a pointer to the
* remainder of the string (with leading whitespace removed), or NULL
* if there was an error.
*/
static const char *parse_attr(const char *src, int lineno, const char *cp,
struct attr_state *e)
{
const char *ep, *equals;
size_t len;
ep = cp + strcspn(cp, blank);
equals = strchr(cp, '=');
if (equals && ep < equals)
equals = NULL;
if (equals)
len = equals - cp;
else
len = ep - cp;
if (!e) {
if (*cp == '-' || *cp == '!') {
cp++;
len--;
}
if (!attr_name_valid(cp, len)) {
report_invalid_attr(cp, len, src, lineno);
return NULL;
}
} else {
/*
* As this function is always called twice, once with
* e == NULL in the first pass and then e != NULL in
* the second pass, no need for attr_name_valid()
* check here.
*/
if (*cp == '-' || *cp == '!') {
e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
cp++;
len--;
}
else if (!equals)
e->setto = ATTR__TRUE;
else {
e->setto = xmemdupz(equals + 1, ep - equals - 1);
}
e->attr = git_attr_internal(cp, len);
}
return ep + strspn(ep, blank);
}
static struct match_attr *parse_attr_line(const char *line, const char *src,
int lineno, unsigned flags)
{
size_t namelen, num_attr, i;
const char *cp, *name, *states;
struct match_attr *res = NULL;
int is_macro;
struct strbuf pattern = STRBUF_INIT;
cp = line + strspn(line, blank);
if (!*cp || *cp == '#')
return NULL;
name = cp;
if (strlen(line) >= ATTR_MAX_LINE_LENGTH) {
warning(_("ignoring overly long attributes line %d"), lineno);
return NULL;
}
if (*cp == '"' && !unquote_c_style(&pattern, name, &states)) {
name = pattern.buf;
namelen = pattern.len;
} else {
namelen = strcspn(name, blank);
states = name + namelen;
}
if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
starts_with(name, ATTRIBUTE_MACRO_PREFIX)) {
if (!(flags & READ_ATTR_MACRO_OK)) {
fprintf_ln(stderr, _("%s not allowed: %s:%d"),
name, src, lineno);
goto fail_return;
}
is_macro = 1;
name += strlen(ATTRIBUTE_MACRO_PREFIX);
name += strspn(name, blank);
namelen = strcspn(name, blank);
if (!attr_name_valid(name, namelen)) {
report_invalid_attr(name, namelen, src, lineno);
goto fail_return;
}
}
else
is_macro = 0;
states += strspn(states, blank);
/* First pass to count the attr_states */
for (cp = states, num_attr = 0; *cp; num_attr++) {
cp = parse_attr(src, lineno, cp, NULL);
if (!cp)
goto fail_return;
}
res = xcalloc(1, st_add3(sizeof(*res),
st_mult(sizeof(struct attr_state), num_attr),
is_macro ? 0 : namelen + 1));
if (is_macro) {
res->u.attr = git_attr_internal(name, namelen);
} else {
char *p = (char *)&(res->state[num_attr]);
memcpy(p, name, namelen);
res->u.pat.pattern = p;
parse_path_pattern(&res->u.pat.pattern,
&res->u.pat.patternlen,
&res->u.pat.flags,
&res->u.pat.nowildcardlen);
if (res->u.pat.flags & PATTERN_FLAG_NEGATIVE) {
warning(_("Negative patterns are ignored in git attributes\n"
"Use '\\!' for literal leading exclamation."));
goto fail_return;
}
}
res->is_macro = is_macro;
res->num_attr = num_attr;
/* Second pass to fill the attr_states */
for (cp = states, i = 0; *cp; i++) {
cp = parse_attr(src, lineno, cp, &(res->state[i]));
}
strbuf_release(&pattern);
return res;
fail_return:
strbuf_release(&pattern);
free(res);
return NULL;
}
/*
* Like info/exclude and .gitignore, the attribute information can
* come from many places.
*
* (1) .gitattributes file of the same directory;
* (2) .gitattributes file of the parent directory if (1) does not have
* any match; this goes recursively upwards, just like .gitignore.
* (3) $GIT_DIR/info/attributes, which overrides both of the above.
*
* In the same file, later entries override the earlier match, so in the
* global list, we would have entries from info/attributes the earliest
* (reading the file from top to bottom), .gitattributes of the root
* directory (again, reading the file from top to bottom) down to the
* current directory, and then scan the list backwards to find the first match.
* This is exactly the same as what is_excluded() does in dir.c to deal with
* .gitignore file and info/excludes file as a fallback.
*/
struct attr_stack {
struct attr_stack *prev;
char *origin;
size_t originlen;
unsigned num_matches;
unsigned alloc;
struct match_attr **attrs;
};
static void attr_stack_free(struct attr_stack *e)
{
unsigned i;
free(e->origin);
for (i = 0; i < e->num_matches; i++) {
struct match_attr *a = e->attrs[i];
size_t j;
for (j = 0; j < a->num_attr; j++) {
const char *setto = a->state[j].setto;
if (setto == ATTR__TRUE ||
setto == ATTR__FALSE ||
setto == ATTR__UNSET ||
setto == ATTR__UNKNOWN)
;
else
free((char *) setto);
}
free(a);
}
free(e->attrs);
free(e);
}
static void drop_attr_stack(struct attr_stack **stack)
{
while (*stack) {
struct attr_stack *elem = *stack;
*stack = elem->prev;
attr_stack_free(elem);
}
}
/* List of all attr_check structs; access should be surrounded by mutex */
static struct check_vector {
size_t nr;
size_t alloc;
struct attr_check **checks;
pthread_mutex_t mutex;
} check_vector;
static inline void vector_lock(void)
{
pthread_mutex_lock(&check_vector.mutex);
}
static inline void vector_unlock(void)
{
pthread_mutex_unlock(&check_vector.mutex);
}
static void check_vector_add(struct attr_check *c)
{
vector_lock();
ALLOC_GROW(check_vector.checks,
check_vector.nr + 1,
check_vector.alloc);
check_vector.checks[check_vector.nr++] = c;
vector_unlock();
}
static void check_vector_remove(struct attr_check *check)
{
int i;
vector_lock();
/* Find entry */
for (i = 0; i < check_vector.nr; i++)
if (check_vector.checks[i] == check)
break;
if (i >= check_vector.nr)
BUG("no entry found");
/* shift entries over */
for (; i < check_vector.nr - 1; i++)
check_vector.checks[i] = check_vector.checks[i + 1];
check_vector.nr--;
vector_unlock();
}
/* Iterate through all attr_check instances and drop their stacks */
static void drop_all_attr_stacks(void)
{
int i;
vector_lock();
for (i = 0; i < check_vector.nr; i++) {
drop_attr_stack(&check_vector.checks[i]->stack);
}
vector_unlock();
}
struct attr_check *attr_check_alloc(void)
{
struct attr_check *c = xcalloc(1, sizeof(struct attr_check));
/* save pointer to the check struct */
check_vector_add(c);
return c;
}
struct attr_check *attr_check_initl(const char *one, ...)
{
struct attr_check *check;
int cnt;
va_list params;
const char *param;
va_start(params, one);
for (cnt = 1; (param = va_arg(params, const char *)) != NULL; cnt++)
;
va_end(params);
check = attr_check_alloc();
check->nr = cnt;
check->alloc = cnt;
CALLOC_ARRAY(check->items, cnt);
check->items[0].attr = git_attr(one);
va_start(params, one);
for (cnt = 1; cnt < check->nr; cnt++) {
const struct git_attr *attr;
param = va_arg(params, const char *);
if (!param)
BUG("counted %d != ended at %d",
check->nr, cnt);
attr = git_attr(param);
if (!attr)
BUG("%s: not a valid attribute name", param);
check->items[cnt].attr = attr;
}
va_end(params);
return check;
}
struct attr_check *attr_check_dup(const struct attr_check *check)
{
struct attr_check *ret;
if (!check)
return NULL;
ret = attr_check_alloc();
ret->nr = check->nr;
ret->alloc = check->alloc;
DUP_ARRAY(ret->items, check->items, ret->nr);
return ret;
}
struct attr_check_item *attr_check_append(struct attr_check *check,
const struct git_attr *attr)
{
struct attr_check_item *item;
ALLOC_GROW(check->items, check->nr + 1, check->alloc);
item = &check->items[check->nr++];
item->attr = attr;
return item;
}
void attr_check_reset(struct attr_check *check)
{
check->nr = 0;
}
void attr_check_clear(struct attr_check *check)
{
FREE_AND_NULL(check->items);
check->alloc = 0;
check->nr = 0;
FREE_AND_NULL(check->all_attrs);
check->all_attrs_nr = 0;
drop_attr_stack(&check->stack);
}
void attr_check_free(struct attr_check *check)
{
if (check) {
/* Remove check from the check vector */
check_vector_remove(check);
attr_check_clear(check);
free(check);
}
}
static const char *builtin_attr[] = {
"[attr]binary -diff -merge -text",
NULL,
};
static void handle_attr_line(struct attr_stack *res,
const char *line,
const char *src,
int lineno,
unsigned flags)
{
struct match_attr *a;
a = parse_attr_line(line, src, lineno, flags);
if (!a)
return;
ALLOC_GROW_BY(res->attrs, res->num_matches, 1, res->alloc);
res->attrs[res->num_matches - 1] = a;
}
static struct attr_stack *read_attr_from_array(const char **list)
{
struct attr_stack *res;
const char *line;
int lineno = 0;
CALLOC_ARRAY(res, 1);
while ((line = *(list++)) != NULL)
handle_attr_line(res, line, "[builtin]", ++lineno,
READ_ATTR_MACRO_OK);
return res;
}
/*
* Callers into the attribute system assume there is a single, system-wide
* global state where attributes are read from and when the state is flipped by
* calling git_attr_set_direction(), the stack frames that have been
* constructed need to be discarded so that subsequent calls into the
* attribute system will lazily read from the right place. Since changing
* direction causes a global paradigm shift, it should not ever be called while
* another thread could potentially be calling into the attribute system.
*/
static enum git_attr_direction direction;
void git_attr_set_direction(enum git_attr_direction new_direction)
{
if (is_bare_repository() && new_direction != GIT_ATTR_INDEX)
BUG("non-INDEX attr direction in a bare repo");
if (new_direction != direction)
drop_all_attr_stacks();
direction = new_direction;
}
static struct attr_stack *read_attr_from_file(const char *path, unsigned flags)
{
struct strbuf buf = STRBUF_INIT;
int fd;
FILE *fp;
struct attr_stack *res;
int lineno = 0;
struct stat st;
if (flags & READ_ATTR_NOFOLLOW)
fd = open_nofollow(path, O_RDONLY);
else
fd = open(path, O_RDONLY);
if (fd < 0) {
warn_on_fopen_errors(path);
return NULL;
}
fp = xfdopen(fd, "r");
if (fstat(fd, &st)) {
warning_errno(_("cannot fstat gitattributes file '%s'"), path);
fclose(fp);
return NULL;
}
if (st.st_size >= ATTR_MAX_FILE_SIZE) {
warning(_("ignoring overly large gitattributes file '%s'"), path);
fclose(fp);
return NULL;
}
CALLOC_ARRAY(res, 1);
while (strbuf_getline(&buf, fp) != EOF) {
if (!lineno && starts_with(buf.buf, utf8_bom))
strbuf_remove(&buf, 0, strlen(utf8_bom));
handle_attr_line(res, buf.buf, path, ++lineno, flags);
}
fclose(fp);
strbuf_release(&buf);
return res;
}
static struct attr_stack *read_attr_from_buf(char *buf, const char *path,
unsigned flags)
{
struct attr_stack *res;
char *sp;
int lineno = 0;
if (!buf)
return NULL;
CALLOC_ARRAY(res, 1);
for (sp = buf; *sp;) {
char *ep;
int more;
ep = strchrnul(sp, '\n');
more = (*ep == '\n');
*ep = '\0';
handle_attr_line(res, sp, path, ++lineno, flags);
sp = ep + more;
}
free(buf);
return res;
}
static struct attr_stack *read_attr_from_blob(struct index_state *istate,
const struct object_id *tree_oid,
const char *path, unsigned flags)
{
struct object_id oid;
unsigned long sz;
enum object_type type;
void *buf;
unsigned short mode;
if (!tree_oid)
return NULL;
if (get_tree_entry(istate->repo, tree_oid, path, &oid, &mode))
return NULL;
buf = repo_read_object_file(istate->repo, &oid, &type, &sz);
if (!buf || type != OBJ_BLOB) {
free(buf);
return NULL;
}
return read_attr_from_buf(buf, path, flags);
}
static struct attr_stack *read_attr_from_index(struct index_state *istate,
const char *path, unsigned flags)
{
struct attr_stack *stack = NULL;
char *buf;
unsigned long size;
int sparse_dir_pos = -1;
if (!istate)
return NULL;
/*
* When handling sparse-checkouts, .gitattributes files
* may reside within a sparse directory. We distinguish
* whether a path exists directly in the index or not by
* evaluating if 'pos' is negative.
* If 'pos' is negative, the path is not directly present
* in the index and is likely within a sparse directory.
* For paths not in the index, The absolute value of 'pos'
* minus 1 gives us the position where the path would be
* inserted in lexicographic order within the index.
* We then subtract another 1 from this value
* (sparse_dir_pos = -pos - 2) to find the position of the
* last index entry which is lexicographically smaller than
* the path. This would be the sparse directory containing
* the path. By identifying the sparse directory containing
* the path, we can correctly read the attributes specified
* in the .gitattributes file from the tree object of the
* sparse directory.
*/
if (!path_in_cone_mode_sparse_checkout(path, istate)) {
int pos = index_name_pos_sparse(istate, path, strlen(path));
if (pos < 0)
sparse_dir_pos = -pos - 2;
}
if (sparse_dir_pos >= 0 &&
S_ISSPARSEDIR(istate->cache[sparse_dir_pos]->ce_mode) &&
!strncmp(istate->cache[sparse_dir_pos]->name, path, ce_namelen(istate->cache[sparse_dir_pos]))) {
const char *relative_path = path + ce_namelen(istate->cache[sparse_dir_pos]);
stack = read_attr_from_blob(istate, &istate->cache[sparse_dir_pos]->oid, relative_path, flags);
} else {
buf = read_blob_data_from_index(istate, path, &size);
if (!buf)
return NULL;
if (size >= ATTR_MAX_FILE_SIZE) {
warning(_("ignoring overly large gitattributes blob '%s'"), path);
return NULL;
}
stack = read_attr_from_buf(buf, path, flags);
}
return stack;
}
static struct attr_stack *read_attr(struct index_state *istate,
const struct object_id *tree_oid,
const char *path, unsigned flags)
{
struct attr_stack *res = NULL;
if (direction == GIT_ATTR_INDEX) {
res = read_attr_from_index(istate, path, flags);
} else if (tree_oid) {
res = read_attr_from_blob(istate, tree_oid, path, flags);
} else if (!is_bare_repository()) {
if (direction == GIT_ATTR_CHECKOUT) {
res = read_attr_from_index(istate, path, flags);
if (!res)
res = read_attr_from_file(path, flags);
} else if (direction == GIT_ATTR_CHECKIN) {
res = read_attr_from_file(path, flags);
if (!res)
/*
* There is no checked out .gitattributes file
* there, but we might have it in the index.
* We allow operation in a sparsely checked out
* work tree, so read from it.
*/
res = read_attr_from_index(istate, path, flags);
}
}
if (!res)
CALLOC_ARRAY(res, 1);
return res;
}
const char *git_attr_system_file(void)
{
static const char *system_wide;
if (!system_wide)
system_wide = system_path(ETC_GITATTRIBUTES);
return system_wide;
}
const char *git_attr_global_file(void)
{
if (!git_attributes_file)
git_attributes_file = xdg_config_home("attributes");
return git_attributes_file;
}
int git_attr_system_is_enabled(void)
{
return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
}
static GIT_PATH_FUNC(git_path_info_attributes, INFOATTRIBUTES_FILE)
static void push_stack(struct attr_stack **attr_stack_p,
struct attr_stack *elem, char *origin, size_t originlen)
{
if (elem) {
elem->origin = origin;
if (origin)
elem->originlen = originlen;
elem->prev = *attr_stack_p;
*attr_stack_p = elem;
}
}
static void bootstrap_attr_stack(struct index_state *istate,
const struct object_id *tree_oid,
struct attr_stack **stack)
{
struct attr_stack *e;
unsigned flags = READ_ATTR_MACRO_OK;
if (*stack)
return;
/* builtin frame */
e = read_attr_from_array(builtin_attr);
push_stack(stack, e, NULL, 0);
/* system-wide frame */
if (git_attr_system_is_enabled()) {
e = read_attr_from_file(git_attr_system_file(), flags);
push_stack(stack, e, NULL, 0);
}
/* home directory */
if (git_attr_global_file()) {
e = read_attr_from_file(git_attr_global_file(), flags);
push_stack(stack, e, NULL, 0);
}
/* root directory */
e = read_attr(istate, tree_oid, GITATTRIBUTES_FILE, flags | READ_ATTR_NOFOLLOW);
push_stack(stack, e, xstrdup(""), 0);
/* info frame */
if (startup_info->have_repository)
e = read_attr_from_file(git_path_info_attributes(), flags);
else
e = NULL;
if (!e)
CALLOC_ARRAY(e, 1);
push_stack(stack, e, NULL, 0);
}
static void prepare_attr_stack(struct index_state *istate,
const struct object_id *tree_oid,
const char *path, int dirlen,
struct attr_stack **stack)
{
struct attr_stack *info;
struct strbuf pathbuf = STRBUF_INIT;
/*
* At the bottom of the attribute stack is the built-in
* set of attribute definitions, followed by the contents
* of $(prefix)/etc/gitattributes and a file specified by
* core.attributesfile. Then, contents from
* .gitattributes files from directories closer to the
* root to the ones in deeper directories are pushed
* to the stack. Finally, at the very top of the stack
* we always keep the contents of $GIT_DIR/info/attributes.
*
* When checking, we use entries from near the top of the
* stack, preferring $GIT_DIR/info/attributes, then
* .gitattributes in deeper directories to shallower ones,
* and finally use the built-in set as the default.
*/
bootstrap_attr_stack(istate, tree_oid, stack);
/*
* Pop the "info" one that is always at the top of the stack.
*/
info = *stack;
*stack = info->prev;
/*
* Pop the ones from directories that are not the prefix of
* the path we are checking. Break out of the loop when we see
* the root one (whose origin is an empty string "") or the builtin
* one (whose origin is NULL) without popping it.
*/
while ((*stack)->origin) {
int namelen = (*stack)->originlen;
struct attr_stack *elem;
elem = *stack;
if (namelen <= dirlen &&
!strncmp(elem->origin, path, namelen) &&
(!namelen || path[namelen] == '/'))
break;
*stack = elem->prev;
attr_stack_free(elem);
}
/*
* bootstrap_attr_stack() should have added, and the
* above loop should have stopped before popping, the
* root element whose attr_stack->origin is set to an
* empty string.
*/
assert((*stack)->origin);
strbuf_addstr(&pathbuf, (*stack)->origin);
/* Build up to the directory 'path' is in */
while (pathbuf.len < dirlen) {
size_t len = pathbuf.len;
struct attr_stack *next;
char *origin;
/* Skip path-separator */
if (len < dirlen && is_dir_sep(path[len]))
len++;
/* Find the end of the next component */
while (len < dirlen && !is_dir_sep(path[len]))
len++;
if (pathbuf.len > 0)
strbuf_addch(&pathbuf, '/');
strbuf_add(&pathbuf, path + pathbuf.len, (len - pathbuf.len));
strbuf_addf(&pathbuf, "/%s", GITATTRIBUTES_FILE);
next = read_attr(istate, tree_oid, pathbuf.buf, READ_ATTR_NOFOLLOW);
/* reset the pathbuf to not include "/.gitattributes" */
strbuf_setlen(&pathbuf, len);
origin = xstrdup(pathbuf.buf);
push_stack(stack, next, origin, len);
}
/*
* Finally push the "info" one at the top of the stack.
*/
push_stack(stack, info, NULL, 0);
strbuf_release(&pathbuf);
}
static int path_matches(const char *pathname, int pathlen,
int basename_offset,
const struct pattern *pat,
const char *base, int baselen)
{
const char *pattern = pat->pattern;
int prefix = pat->nowildcardlen;
int isdir = (pathlen && pathname[pathlen - 1] == '/');
if ((pat->flags & PATTERN_FLAG_MUSTBEDIR) && !isdir)
return 0;
if (pat->flags & PATTERN_FLAG_NODIR) {
return match_basename(pathname + basename_offset,
pathlen - basename_offset - isdir,
pattern, prefix,
pat->patternlen, pat->flags);
}
return match_pathname(pathname, pathlen - isdir,
base, baselen,
pattern, prefix, pat->patternlen);
}
static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem);
static int fill_one(struct all_attrs_item *all_attrs,
const struct match_attr *a, int rem)
{
size_t i;
for (i = a->num_attr; rem > 0 && i > 0; i--) {
const struct git_attr *attr = a->state[i - 1].attr;
const char **n = &(all_attrs[attr->attr_nr].value);
const char *v = a->state[i - 1].setto;
if (*n == ATTR__UNKNOWN) {
*n = v;
rem--;
rem = macroexpand_one(all_attrs, attr->attr_nr, rem);
}
}
return rem;
}
static int fill(const char *path, int pathlen, int basename_offset,
const struct attr_stack *stack,
struct all_attrs_item *all_attrs, int rem)
{
for (; rem > 0 && stack; stack = stack->prev) {
unsigned i;
const char *base = stack->origin ? stack->origin : "";
for (i = stack->num_matches; 0 < rem && 0 < i; i--) {
const struct match_attr *a = stack->attrs[i - 1];
if (a->is_macro)
continue;
if (path_matches(path, pathlen, basename_offset,
&a->u.pat, base, stack->originlen))
rem = fill_one(all_attrs, a, rem);
}
}
return rem;
}
static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem)
{
const struct all_attrs_item *item = &all_attrs[nr];
if (item->macro && item->value == ATTR__TRUE)
return fill_one(all_attrs, item->macro, rem);
else
return rem;
}
/*
* Marks the attributes which are macros based on the attribute stack.
* This prevents having to search through the attribute stack each time
* a macro needs to be expanded during the fill stage.
*/
static void determine_macros(struct all_attrs_item *all_attrs,
const struct attr_stack *stack)
{
for (; stack; stack = stack->prev) {
unsigned i;
for (i = stack->num_matches; i > 0; i--) {
const struct match_attr *ma = stack->attrs[i - 1];
if (ma->is_macro) {
unsigned int n = ma->u.attr->attr_nr;
if (!all_attrs[n].macro) {
all_attrs[n].macro = ma;
}
}
}
}
}
/*
* Collect attributes for path into the array pointed to by check->all_attrs.
* If check->check_nr is non-zero, only attributes in check[] are collected.
* Otherwise all attributes are collected.
*/
static void collect_some_attrs(struct index_state *istate,
const struct object_id *tree_oid,
const char *path, struct attr_check *check)
{
int pathlen, rem, dirlen;
const char *cp, *last_slash = NULL;
int basename_offset;
for (cp = path; *cp; cp++) {
if (*cp == '/' && cp[1])
last_slash = cp;
}
pathlen = cp - path;
if (last_slash) {
basename_offset = last_slash + 1 - path;
dirlen = last_slash - path;
} else {
basename_offset = 0;
dirlen = 0;
}
prepare_attr_stack(istate, tree_oid, path, dirlen, &check->stack);
all_attrs_init(&g_attr_hashmap, check);
determine_macros(check->all_attrs, check->stack);
rem = check->all_attrs_nr;
fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
}
static const char *default_attr_source_tree_object_name;
static int ignore_bad_attr_tree;
void set_git_attr_source(const char *tree_object_name)
{
default_attr_source_tree_object_name = xstrdup(tree_object_name);
}
static void compute_default_attr_source(struct object_id *attr_source)
{
if (!default_attr_source_tree_object_name)
default_attr_source_tree_object_name = getenv(GIT_ATTR_SOURCE_ENVIRONMENT);
if (!default_attr_source_tree_object_name && git_attr_tree) {
default_attr_source_tree_object_name = git_attr_tree;
ignore_bad_attr_tree = 1;
}
if (!default_attr_source_tree_object_name &&
startup_info->have_repository &&
is_bare_repository()) {
default_attr_source_tree_object_name = "HEAD";
ignore_bad_attr_tree = 1;
}
if (!default_attr_source_tree_object_name || !is_null_oid(attr_source))
return;
if (repo_get_oid_treeish(the_repository,
default_attr_source_tree_object_name,
attr_source) && !ignore_bad_attr_tree)
die(_("bad --attr-source or GIT_ATTR_SOURCE"));
}
static struct object_id *default_attr_source(void)
{
static struct object_id attr_source;
if (is_null_oid(&attr_source))
compute_default_attr_source(&attr_source);
if (is_null_oid(&attr_source))
return NULL;
return &attr_source;
}
void git_check_attr(struct index_state *istate,
const char *path,
struct attr_check *check)
{
int i;
const struct object_id *tree_oid = default_attr_source();
collect_some_attrs(istate, tree_oid, path, check);
for (i = 0; i < check->nr; i++) {
unsigned int n = check->items[i].attr->attr_nr;
const char *value = check->all_attrs[n].value;
if (value == ATTR__UNKNOWN)
value = ATTR__UNSET;
check->items[i].value = value;
}
}
void git_all_attrs(struct index_state *istate,
const char *path, struct attr_check *check)
{
int i;
const struct object_id *tree_oid = default_attr_source();
attr_check_reset(check);
collect_some_attrs(istate, tree_oid, path, check);
for (i = 0; i < check->all_attrs_nr; i++) {
const char *name = check->all_attrs[i].attr->name;
const char *value = check->all_attrs[i].value;
struct attr_check_item *item;
if (value == ATTR__UNSET || value == ATTR__UNKNOWN)
continue;
item = attr_check_append(check, git_attr(name));
item->value = value;
}
}
void attr_start(void)
{
pthread_mutex_init(&g_attr_hashmap.mutex, NULL);
pthread_mutex_init(&check_vector.mutex, NULL);
}