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#include "cache.h"
#include "attr.h"
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
/*
* The basic design decision here is that we are not going to have
* insanely large number of attributes.
*
* This is a randomly chosen prime.
*/
#define HASHSIZE 257
#ifndef DEBUG_ATTR
#define DEBUG_ATTR 0
#endif
struct git_attr {
struct git_attr *next;
unsigned h;
int attr_nr;
char name[FLEX_ARRAY];
};
static int attr_nr;
static struct git_attr_check *check_all_attr;
static struct git_attr *(git_attr_hash[HASHSIZE]);
static unsigned hash_name(const char *name, int namelen)
{
unsigned val = 0;
unsigned char c;
while (namelen--) {
c = *name++;
val = ((val << 7) | (val >> 22)) ^ c;
}
return val;
}
static int invalid_attr_name(const char *name, int namelen)
{
/*
* Attribute name cannot begin with '-' and from
* [-A-Za-z0-9_.]. We'd specifically exclude '=' for now,
* as we might later want to allow non-binary value for
* attributes, e.g. "*.svg merge=special-merge-program-for-svg"
*/
if (*name == '-')
return -1;
while (namelen--) {
char ch = *name++;
if (! (ch == '-' || ch == '.' || ch == '_' ||
('0' <= ch && ch <= '9') ||
('a' <= ch && ch <= 'z') ||
('A' <= ch && ch <= 'Z')) )
return -1;
}
return 0;
}
struct git_attr *git_attr(const char *name, int len)
{
unsigned hval = hash_name(name, len);
unsigned pos = hval % HASHSIZE;
struct git_attr *a;
for (a = git_attr_hash[pos]; a; a = a->next) {
if (a->h == hval &&
!memcmp(a->name, name, len) && !a->name[len])
return a;
}
if (invalid_attr_name(name, len))
return NULL;
a = xmalloc(sizeof(*a) + len + 1);
memcpy(a->name, name, len);
a->name[len] = 0;
a->h = hval;
a->next = git_attr_hash[pos];
a->attr_nr = attr_nr++;
git_attr_hash[pos] = a;
check_all_attr = xrealloc(check_all_attr,
sizeof(*check_all_attr) * attr_nr);
check_all_attr[a->attr_nr].attr = a;
check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
return a;
}
/*
* .gitattributes file is one line per record, each of which is
*
* (1) glob pattern.
* (2) whitespace
* (3) whitespace separated list of attribute names, each of which
* could be prefixed with '-' to mean "set to false", '!' to mean
* "unset".
*/
/* What does a matched pattern decide? */
struct attr_state {
struct git_attr *attr;
const char *setto;
};
struct match_attr {
union {
char *pattern;
struct git_attr *attr;
} u;
char is_macro;
unsigned num_attr;
struct attr_state state[FLEX_ARRAY];
};
static const char blank[] = " \t\r\n";
static const char *parse_attr(const char *src, int lineno, const char *cp,
int *num_attr, struct match_attr *res)
{
const char *ep, *equals;
int 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 (!res) {
if (*cp == '-' || *cp == '!') {
cp++;
len--;
}
if (invalid_attr_name(cp, len)) {
fprintf(stderr,
"%.*s is not a valid attribute name: %s:%d\n",
len, cp, src, lineno);
return NULL;
}
} else {
struct attr_state *e;
e = &(res->state[*num_attr]);
if (*cp == '-' || *cp == '!') {
e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
cp++;
len--;
}
else if (!equals)
e->setto = ATTR__TRUE;
else {
char *value;
int vallen = ep - equals;
value = xmalloc(vallen);
memcpy(value, equals+1, vallen-1);
value[vallen-1] = 0;
e->setto = value;
}
e->attr = git_attr(cp, len);
}
(*num_attr)++;
return ep + strspn(ep, blank);
}
static struct match_attr *parse_attr_line(const char *line, const char *src,
int lineno, int macro_ok)
{
int namelen;
int num_attr;
const char *cp, *name;
struct match_attr *res = NULL;
int pass;
int is_macro;
cp = line + strspn(line, blank);
if (!*cp || *cp == '#')
return NULL;
name = cp;
namelen = strcspn(name, blank);
if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
!prefixcmp(name, ATTRIBUTE_MACRO_PREFIX)) {
if (!macro_ok) {
fprintf(stderr, "%s not allowed: %s:%d\n",
name, src, lineno);
return NULL;
}
is_macro = 1;
name += strlen(ATTRIBUTE_MACRO_PREFIX);
name += strspn(name, blank);
namelen = strcspn(name, blank);
if (invalid_attr_name(name, namelen)) {
fprintf(stderr,
"%.*s is not a valid attribute name: %s:%d\n",
namelen, name, src, lineno);
return NULL;
}
}
else
is_macro = 0;
for (pass = 0; pass < 2; pass++) {
/* pass 0 counts and allocates, pass 1 fills */
num_attr = 0;
cp = name + namelen;
cp = cp + strspn(cp, blank);
while (*cp)
cp = parse_attr(src, lineno, cp, &num_attr, res);
if (pass)
break;
res = xcalloc(1,
sizeof(*res) +
sizeof(struct attr_state) * num_attr +
(is_macro ? 0 : namelen + 1));
if (is_macro)
res->u.attr = git_attr(name, namelen);
else {
res->u.pattern = (char*)&(res->state[num_attr]);
memcpy(res->u.pattern, name, namelen);
res->u.pattern[namelen] = 0;
}
res->is_macro = is_macro;
res->num_attr = num_attr;
}
return res;
}
/*
* Like info/exclude and .gitignore, the attribute information can
* come from many places.
*
* (1) .gitattribute file of the same directory;
* (2) .gitattribute 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), .gitattribute 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 excluded() does in dir.c to deal with
* .gitignore
*/
static struct attr_stack {
struct attr_stack *prev;
char *origin;
unsigned num_matches;
unsigned alloc;
struct match_attr **attrs;
} *attr_stack;
static void free_attr_elem(struct attr_stack *e)
{
int i;
free(e->origin);
for (i = 0; i < e->num_matches; i++) {
struct match_attr *a = e->attrs[i];
int 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);
}
static const char *builtin_attr[] = {
"[attr]binary -diff -crlf",
NULL,
};
static void handle_attr_line(struct attr_stack *res,
const char *line,
const char *src,
int lineno,
int macro_ok)
{
struct match_attr *a;
a = parse_attr_line(line, src, lineno, macro_ok);
if (!a)
return;
if (res->alloc <= res->num_matches) {
res->alloc = alloc_nr(res->num_matches);
res->attrs = xrealloc(res->attrs,
sizeof(struct match_attr *) *
res->alloc);
}
res->attrs[res->num_matches++] = a;
}
static struct attr_stack *read_attr_from_array(const char **list)
{
struct attr_stack *res;
const char *line;
int lineno = 0;
res = xcalloc(1, sizeof(*res));
while ((line = *(list++)) != NULL)
handle_attr_line(res, line, "[builtin]", ++lineno, 1);
return res;
}
static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
{
FILE *fp = fopen(path, "r");
struct attr_stack *res;
char buf[2048];
int lineno = 0;
if (!fp)
return NULL;
res = xcalloc(1, sizeof(*res));
while (fgets(buf, sizeof(buf), fp))
handle_attr_line(res, buf, path, ++lineno, macro_ok);
fclose(fp);
return res;
}
static void *read_index_data(const char *path)
{
int pos, len;
unsigned long sz;
enum object_type type;
void *data;
len = strlen(path);
pos = cache_name_pos(path, len);
if (pos < 0) {
/*
* We might be in the middle of a merge, in which
* case we would read stage #2 (ours).
*/
int i;
for (i = -pos - 1;
(pos < 0 && i < active_nr &&
!strcmp(active_cache[i]->name, path));
i++)
if (ce_stage(active_cache[i]) == 2)
pos = i;
}
if (pos < 0)
return NULL;
data = read_sha1_file(active_cache[pos]->sha1, &type, &sz);
if (!data || type != OBJ_BLOB) {
free(data);
return NULL;
}
return data;
}
static struct attr_stack *read_attr(const char *path, int macro_ok)
{
struct attr_stack *res;
char *buf, *sp;
int lineno = 0;
res = read_attr_from_file(path, macro_ok);
if (res)
return res;
res = xcalloc(1, sizeof(*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.
*/
buf = read_index_data(path);
if (!buf)
return res;
for (sp = buf; *sp; ) {
char *ep;
int more;
for (ep = sp; *ep && *ep != '\n'; ep++)
;
more = (*ep == '\n');
*ep = '\0';
handle_attr_line(res, sp, path, ++lineno, macro_ok);
sp = ep + more;
}
free(buf);
return res;
}
#if DEBUG_ATTR
static void debug_info(const char *what, struct attr_stack *elem)
{
fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
}
static void debug_set(const char *what, const char *match, struct git_attr *attr, void *v)
{
const char *value = v;
if (ATTR_TRUE(value))
value = "set";
else if (ATTR_FALSE(value))
value = "unset";
else if (ATTR_UNSET(value))
value = "unspecified";
fprintf(stderr, "%s: %s => %s (%s)\n",
what, attr->name, (char *) value, match);
}
#define debug_push(a) debug_info("push", (a))
#define debug_pop(a) debug_info("pop", (a))
#else
#define debug_push(a) do { ; } while (0)
#define debug_pop(a) do { ; } while (0)
#define debug_set(a,b,c,d) do { ; } while (0)
#endif
static void bootstrap_attr_stack(void)
{
if (!attr_stack) {
struct attr_stack *elem;
elem = read_attr_from_array(builtin_attr);
elem->origin = NULL;
elem->prev = attr_stack;
attr_stack = elem;
elem = read_attr(GITATTRIBUTES_FILE, 1);
elem->origin = strdup("");
elem->prev = attr_stack;
attr_stack = elem;
debug_push(elem);
elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
if (!elem)
elem = xcalloc(1, sizeof(*elem));
elem->origin = NULL;
elem->prev = attr_stack;
attr_stack = elem;
}
}
static void prepare_attr_stack(const char *path, int dirlen)
{
struct attr_stack *elem, *info;
int len;
char pathbuf[PATH_MAX];
/*
* At the bottom of the attribute stack is the built-in
* set of attribute definitions. Then, contents from
* .gitattribute 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.
*/
if (!attr_stack)
bootstrap_attr_stack();
/*
* Pop the "info" one that is always at the top of the stack.
*/
info = attr_stack;
attr_stack = info->prev;
/*
* Pop the ones from directories that are not the prefix of
* the path we are checking.
*/
while (attr_stack && attr_stack->origin) {
int namelen = strlen(attr_stack->origin);
elem = attr_stack;
if (namelen <= dirlen &&
!strncmp(elem->origin, path, namelen))
break;
debug_pop(elem);
attr_stack = elem->prev;
free_attr_elem(elem);
}
/*
* Read from parent directories and push them down
*/
while (1) {
char *cp;
len = strlen(attr_stack->origin);
if (dirlen <= len)
break;
memcpy(pathbuf, path, dirlen);
memcpy(pathbuf + dirlen, "/", 2);
cp = strchr(pathbuf + len + 1, '/');
strcpy(cp + 1, GITATTRIBUTES_FILE);
elem = read_attr(pathbuf, 0);
*cp = '\0';
elem->origin = strdup(pathbuf);
elem->prev = attr_stack;
attr_stack = elem;
debug_push(elem);
}
/*
* Finally push the "info" one at the top of the stack.
*/
info->prev = attr_stack;
attr_stack = info;
}
static int path_matches(const char *pathname, int pathlen,
const char *pattern,
const char *base, int baselen)
{
if (!strchr(pattern, '/')) {
/* match basename */
const char *basename = strrchr(pathname, '/');
basename = basename ? basename + 1 : pathname;
return (fnmatch(pattern, basename, 0) == 0);
}
/*
* match with FNM_PATHNAME; the pattern has base implicitly
* in front of it.
*/
if (*pattern == '/')
pattern++;
if (pathlen < baselen ||
(baselen && pathname[baselen - 1] != '/') ||
strncmp(pathname, base, baselen))
return 0;
return fnmatch(pattern, pathname + baselen, FNM_PATHNAME) == 0;
}
static int fill_one(const char *what, struct match_attr *a, int rem)
{
struct git_attr_check *check = check_all_attr;
int i;
for (i = 0; 0 < rem && i < a->num_attr; i++) {
struct git_attr *attr = a->state[i].attr;
const char **n = &(check[attr->attr_nr].value);
const char *v = a->state[i].setto;
if (*n == ATTR__UNKNOWN) {
debug_set(what, a->u.pattern, attr, v);
*n = v;
rem--;
}
}
return rem;
}
static int fill(const char *path, int pathlen, struct attr_stack *stk, int rem)
{
int i;
const char *base = stk->origin ? stk->origin : "";
for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
struct match_attr *a = stk->attrs[i];
if (a->is_macro)
continue;
if (path_matches(path, pathlen,
a->u.pattern, base, strlen(base)))
rem = fill_one("fill", a, rem);
}
return rem;
}
static int macroexpand(struct attr_stack *stk, int rem)
{
int i;
struct git_attr_check *check = check_all_attr;
for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
struct match_attr *a = stk->attrs[i];
if (!a->is_macro)
continue;
if (check[a->u.attr->attr_nr].value != ATTR__TRUE)
continue;
rem = fill_one("expand", a, rem);
}
return rem;
}
int git_checkattr(const char *path, int num, struct git_attr_check *check)
{
struct attr_stack *stk;
const char *cp;
int dirlen, pathlen, i, rem;
bootstrap_attr_stack();
for (i = 0; i < attr_nr; i++)
check_all_attr[i].value = ATTR__UNKNOWN;
pathlen = strlen(path);
cp = strrchr(path, '/');
if (!cp)
dirlen = 0;
else
dirlen = cp - path;
prepare_attr_stack(path, dirlen);
rem = attr_nr;
for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
rem = fill(path, pathlen, stk, rem);
for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
rem = macroexpand(stk, rem);
for (i = 0; i < num; i++) {
const char *value = check_all_attr[check[i].attr->attr_nr].value;
if (value == ATTR__UNKNOWN)
value = ATTR__UNSET;
check[i].value = value;
}
return 0;
}
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