1 files changed, 115 insertions, 1 deletions
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 411d779be6b..7701fc5ac07 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -5105,7 +5105,7 @@ select_best_grantor(Oid roleId, AclMode privileges,
 /*
  * get_role_oid - Given a role name, look up the role's OID.
  *
- * If missing_ok is false, throw an error if tablespace name not found.  If
+ * If missing_ok is false, throw an error if role name not found.  If
  * true, just return InvalidOid.
  */
 Oid
@@ -5133,3 +5133,117 @@ get_role_oid_or_public(const char *rolname)
 
 	return get_role_oid(rolname, false);
 }
+
+/*
+ * Given a RoleSpec node, return the OID it corresponds to.  If missing_ok is
+ * true, return InvalidOid if the role does not exist.
+ *
+ * PUBLIC is always disallowed here.  Routines wanting to handle the PUBLIC
+ * case must check the case separately.
+ */
+Oid
+get_rolespec_oid(const Node *node, bool missing_ok)
+{
+	RoleSpec   *role;
+	Oid			oid;
+
+	if (!IsA(node, RoleSpec))
+		elog(ERROR, "invalid node type %d", node->type);
+
+	role = (RoleSpec *) node;
+	switch (role->roletype)
+	{
+		case ROLESPEC_CSTRING:
+			Assert(role->rolename);
+			oid = get_role_oid(role->rolename, missing_ok);
+			break;
+
+		case ROLESPEC_CURRENT_USER:
+			oid = GetUserId();
+			break;
+
+		case ROLESPEC_SESSION_USER:
+			oid = GetSessionUserId();
+			break;
+
+		case ROLESPEC_PUBLIC:
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("role \"%s\" does not exist", "public")));
+			oid = InvalidOid;	/* make compiler happy */
+			break;
+
+		default:
+			elog(ERROR, "unexpected role type %d", role->roletype);
+	}
+
+	return oid;
+}
+
+/*
+ * Given a RoleSpec node, return the pg_authid HeapTuple it corresponds to.
+ * Caller must ReleaseSysCache when done with the result tuple.
+ */
+HeapTuple
+get_rolespec_tuple(const Node *node)
+{
+	RoleSpec   *role;
+	HeapTuple	tuple;
+
+	role = (RoleSpec *) node;
+	if (!IsA(node, RoleSpec))
+		elog(ERROR, "invalid node type %d", node->type);
+
+	switch (role->roletype)
+	{
+		case ROLESPEC_CSTRING:
+			Assert(role->rolename);
+			tuple = SearchSysCache1(AUTHNAME, CStringGetDatum(role->rolename));
+			if (!HeapTupleIsValid(tuple))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("role \"%s\" does not exist", role->rolename)));
+			break;
+
+		case ROLESPEC_CURRENT_USER:
+			tuple = SearchSysCache1(AUTHOID, GetUserId());
+			if (!HeapTupleIsValid(tuple))
+				elog(ERROR, "cache lookup failed for role %u", GetUserId());
+			break;
+
+		case ROLESPEC_SESSION_USER:
+			tuple = SearchSysCache1(AUTHOID, GetSessionUserId());
+			if (!HeapTupleIsValid(tuple))
+				elog(ERROR, "cache lookup failed for role %u", GetSessionUserId());
+			break;
+
+		case ROLESPEC_PUBLIC:
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("role \"%s\" does not exist", "public")));
+			tuple = NULL;	/* make compiler happy */
+
+		default:
+			elog(ERROR, "unexpected role type %d", role->roletype);
+	}
+
+	return tuple;
+}
+
+/*
+ * Given a RoleSpec, returns a palloc'ed copy of the corresponding role's name.
+ */
+char *
+get_rolespec_name(const Node *node)
+{
+	HeapTuple	tp;
+	Form_pg_authid authForm;
+	char	   *rolename;
+
+	tp = get_rolespec_tuple(node);
+	authForm = (Form_pg_authid) GETSTRUCT(tp);
+	rolename = pstrdup(NameStr(authForm->rolname));
+	ReleaseSysCache(tp);
+
+	return rolename;
+}