Index: src/pmc/managedstruct.pmc
===================================================================
--- src/pmc/managedstruct.pmc	(revision 38350)
+++ src/pmc/managedstruct.pmc	(working copy)
@@ -29,12 +29,12 @@
      * custom_free_func is called before the normal destroy() function does any
      * work.
      */
-    ATTR void *custom_free_func;
+    ATTR void (*custom_free_func)(PARROT_INTERP, void *, void *);
     ATTR void *custom_free_priv;
     /* if custom_clone_func is set, it will be called *instead* of the normal
      * clone() function logic.
      */
-    ATTR void *custom_clone_func;
+    ATTR PMC * (*custom_clone_func)(PARROT_INTERP, PMC *ptr, void *priv);
     ATTR void *custom_clone_priv;
 
 /*
@@ -86,8 +86,7 @@
     VTABLE void destroy() {
         void *ptr = PARROT_MANAGEDSTRUCT(SELF)->ptr;
         if (ptr) {
-            custom_free_func_t free_func =
-                (custom_free_func_t)PARROT_MANAGEDSTRUCT(SELF)->custom_free_func;
+            custom_free_func_t free_func = PARROT_MANAGEDSTRUCT(SELF)->custom_free_func;
             if (free_func) {
                 void *free_data = PARROT_MANAGEDSTRUCT(SELF)->custom_free_priv;
                 free_func(interp, ptr, free_data);
@@ -144,8 +143,7 @@
 */
 
     VTABLE PMC *clone() {
-        custom_clone_func_t clone_func =
-            (custom_clone_func_t)PARROT_MANAGEDSTRUCT(SELF)->custom_clone_func;
+        custom_clone_func_t clone_func = PARROT_MANAGEDSTRUCT(SELF)->custom_clone_func;
         PMC *dest;
         if (clone_func) {
             void *clone_data = PARROT_MANAGEDSTRUCT(SELF)->custom_clone_priv;
Index: lib/Parrot/Pmc2c/Parser.pm
===================================================================
--- lib/Parrot/Pmc2c/Parser.pm	(revision 38350)
+++ lib/Parrot/Pmc2c/Parser.pm	(working copy)
@@ -135,7 +135,10 @@
 
         # name
         \s*
-        (\w+)
+        (
+            \w+
+          | \(\*\w*\)\(.*?\)
+        )
 
         # modifiers
         \s*
Index: lib/Parrot/Pmc2c/Attribute.pm
===================================================================
--- lib/Parrot/Pmc2c/Attribute.pm	(revision 38350)
+++ lib/Parrot/Pmc2c/Attribute.pm	(working copy)
@@ -99,6 +99,13 @@
     my $pmcname        = $pmc->{name};
     my $attrtype       = $self->{type};
     my $attrname       = $self->{name};
+    my $isfuncptr      = 0;
+    my $origtype       = $attrtype;
+    if($attrname =~ m/\(\*(\w*)\)\((.*?)\)/) {
+        $isfuncptr = 1;
+        $origtype = $attrtype . " (*)(" . $2 . ")";
+        $attrname = $1;
+    }
 
     # Store regexes used to check some types to avoid repetitions
     my $isptrtostring = qr/STRING\s*\*$/;
@@ -113,8 +120,15 @@
         if (PObj_is_object_TEST(pmc)) { \\
 EOA
 
-    if ($attrtype eq "INTVAL") {
+    if ($isfuncptr == 1) {
         $decl .= <<"EOA";
+            Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_INVALID_OPERATION, \\
+                "Attributes of type '$origtype' cannot be " \\
+                "subclassed from a high-level PMC."); \\
+EOA
+    }
+    elsif ($attrtype eq "INTVAL") {
+        $decl .= <<"EOA";
             PMC *attr_value = VTABLE_get_attr_str(interp, \\
                               pmc, Parrot_str_new_constant(interp, "$attrname")); \\
             (dest) = (PMC_IS_NULL(attr_value) ? (INTVAL) 0: VTABLE_get_integer(interp, attr_value)); \\
@@ -161,8 +175,15 @@
         if (PObj_is_object_TEST(pmc)) { \\
 EOA
 
-    if ($attrtype eq "INTVAL") {
+    if ($isfuncptr == 1) {
         $decl .= <<"EOA";
+            Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_INVALID_OPERATION, \\
+                "Attributes of type '$origtype' cannot be " \\
+                "subclassed from a high-level PMC."); \\
+EOA
+    }
+    elsif ($attrtype eq "INTVAL") {
+        $decl .= <<"EOA";
             PMC *attr_value = pmc_new(interp, enum_class_Integer); \\
             VTABLE_set_integer_native(interp, attr_value, value); \\
             VTABLE_set_attr_str(interp, pmc, \\