Store class in closures to allow super super calls

src/core/core.c

@@ -1590,11 +1590,11 @@ Var getMethod(PKVM* vm, Var self, String* name, bool* is_method) {
   return varGetAttrib(vm, self, name);
 }
 
-Closure* getSuperMethod(PKVM* vm, Var self, String* name) {
-  Class* super = getClass(vm, self)->super_class;
+Closure* getSuperMethod(PKVM* vm, Class* class, String* name) {
+  Class* super = NULL == class ? NULL : class->super_class;
   if (super == NULL) {
-    VM_SET_ERROR(vm, stringFormat(vm, "'$' object has no parent class.", \
-                 varTypeName(self)));
+    VM_SET_ERROR(vm, stringFormat(vm, "'$' has no parent class.", \
+                 class->name));
     return NULL;
   };
 

src/core/core.h

@@ -89,7 +89,7 @@ Var getMethod(PKVM* vm, Var self, String* name, bool* is_method);
 
 // Returns the method (closure) from the instance's super class. If the method
 // doesn't exists, it'll set an error on the VM.
-Closure* getSuperMethod(PKVM* vm, Var self, String* name);
+Closure* getSuperMethod(PKVM* vm, Class* class, String* name);
 
 // Unlike getMethod this will not set error and will not try to get attribute
 // with the same name. It'll return true if the method exists on [self], false

src/core/public.c

@@ -306,6 +306,7 @@ void pkClassAddMethod(PKVM* vm, PkHandle* cls,
   // won't be garbage collected (class handle has reference to the module).
 
   Closure* method = newClosure(vm, fn);
+  method->class = class_;
   vmPopTempRef(vm); // fn.
   vmPushTempRef(vm, &method->_super); // method.
   {

src/core/value.h

@@ -402,6 +402,7 @@ struct Function {
 struct Closure {
   Object _super;
 
+  Class* class;
   Function* fn;
   Upvalue* upvalues[DYNAMIC_TAIL_ARRAY];
 };

src/core/vm.c

@@ -1130,6 +1130,8 @@ PkResult vmRunFiber(PKVM* vm, Fiber* fiber_) {
         cls->ctor = method;
       }
 
+      method->class = cls;
+
       pkClosureBufferWrite(&cls->methods, vm, method);
 
       DROP();
@@ -1198,7 +1200,9 @@ PkResult vmRunFiber(PKVM* vm, Fiber* fiber_) {
         fiber->self = *fiber->ret; //< Self for the next call.
         index = READ_SHORT();
         name = moduleGetStringAt(module, (int)index);
-        Closure* super_method = getSuperMethod(vm, fiber->self, name);
+        Class* class = frame->closure->class;
+        if ( NULL == class ) class = getClass( vm, fiber->self );
+        Closure* super_method = getSuperMethod(vm, class, name);
         CHECK_ERROR(); // Will return if super_method is NULL.
         callable = VAR_OBJ(super_method);
       goto L_do_call;
@@ -1253,6 +1257,7 @@ PkResult vmRunFiber(PKVM* vm, Fiber* fiber_) {
         *fiber->ret = fiber->self;
 
         closure = (const Closure*)(cls)->ctor;
+        const char* class_name = cls->name->data;
         while (closure == NULL) {
           cls = cls->super_class;
           if (cls == NULL) break;
@@ -1263,7 +1268,7 @@ PkResult vmRunFiber(PKVM* vm, Fiber* fiber_) {
         if (closure == NULL) {
           if (argc != 0) {
             String* msg = stringFormat(vm, "Expected exactly 0 argument(s) "
-                                       "for constructor $.", cls->name->data);
+                                       "for constructor $.", class_name );
             RUNTIME_ERROR(msg);
           }
 

tests/lang/class.pk

@@ -246,7 +246,20 @@ class B is A
   end
 end
 
+class C is B
+  def _init()
+    super()
+    print("C init")
+  end
+  def foo()
+    print("C foo")
+    return super.foo()
+  end
+end
+
 b = B()
 assert(b.foo() == "A.bar")
+c = C()
+assert(c.foo() == "A.bar")
 
 print('ALL TESTS PASSED')