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-rw-r--r--attr.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/attr.c b/attr.c
new file mode 100644
index 0000000000..a0712543b2
--- /dev/null
+++ b/attr.c
@@ -0,0 +1,565 @@
+#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;
+ 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 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) {
+ struct match_attr *a;
+
+ a = parse_attr_line(line, "[builtin]", ++lineno, 1);
+ if (!a)
+ continue;
+ res->attrs = xrealloc(res->attrs,
+ sizeof(struct match_attr *) * (res->num_matches + 1));
+ res->attrs[res->num_matches++] = a;
+ }
+ return res;
+}
+
+static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
+{
+ FILE *fp;
+ struct attr_stack *res;
+ char buf[2048];
+ int lineno = 0;
+
+ res = xcalloc(1, sizeof(*res));
+ fp = fopen(path, "r");
+ if (!fp)
+ return res;
+
+ while (fgets(buf, sizeof(buf), fp)) {
+ struct match_attr *a;
+
+ a = parse_attr_line(buf, path, ++lineno, macro_ok);
+ if (!a)
+ continue;
+ res->attrs = xrealloc(res->attrs,
+ sizeof(struct match_attr *) * (res->num_matches + 1));
+ res->attrs[res->num_matches++] = a;
+ }
+ fclose(fp);
+ 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_from_file(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);
+ 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_from_file(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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-26 11:20:13 +0000