Specify metaclass and create class with correct type.

Author: cthulahoops

vm/src/builtins.rs

@@ -644,14 +644,10 @@ pub fn make_module(ctx: &PyContext) -> PyObjectRef {
 pub fn builtin_build_class_(vm: &mut VirtualMachine, mut args: PyFuncArgs) -> PyResult {
     let function = args.shift();
     let name_arg = args.shift();
-    let name_arg_ref = name_arg.borrow();
-    let name = match name_arg_ref.kind {
-        PyObjectKind::String { ref value } => value,
-        _ => panic!("Class name must by a string!"),
-    };
     let mut bases = args.args.clone();
+    let metaclass = args.get_kwarg("metaclass", vm.get_type());
+
     bases.push(vm.context().object());
-    let metaclass = vm.get_type();
     let namespace = vm.new_dict();
     &vm.invoke(
         function,
@@ -660,5 +656,8 @@ pub fn builtin_build_class_(vm: &mut VirtualMachine, mut args: PyFuncArgs) -> Py
             kwargs: vec![],
         },
     );
-    objtype::new(metaclass, name, bases, namespace)
+
+    let bases = vm.context().new_tuple(bases);
+
+    vm.call_method(&metaclass, "__new__", vec![name_arg, bases, namespace])
 }

vm/src/compile.rs

@@ -436,7 +436,7 @@ impl Compiler {
                 name,
                 body,
                 bases,
-                keywords: _,
+                keywords,
                 decorator_list,
             } => {
                 self.prepare_decorators(decorator_list)?;
@@ -483,9 +483,34 @@ impl Compiler {
                 for base in bases {
                     self.compile_expression(base)?;
                 }
-                self.emit(Instruction::CallFunction {
-                    typ: CallType::Positional(2 + bases.len()),
-                });
+
+                if keywords.len() > 0 {
+                    let mut kwarg_names = vec![];
+                    for keyword in keywords {
+                        if let Some(name) = &keyword.name {
+                            kwarg_names.push(bytecode::Constant::String {
+                                value: name.to_string(),
+                            });
+                        } else {
+                            // This means **kwargs!
+                            panic!("name must be set");
+                        }
+                        self.compile_expression(&keyword.value)?;
+                    }
+
+                    self.emit(Instruction::LoadConst {
+                        value: bytecode::Constant::Tuple {
+                            elements: kwarg_names,
+                        },
+                    });
+                    self.emit(Instruction::CallFunction {
+                        typ: CallType::Keyword(2 + keywords.len() + bases.len()),
+                    });
+                } else {
+                    self.emit(Instruction::CallFunction {
+                        typ: CallType::Positional(2 + bases.len()),
+                    });
+                }
 
                 self.apply_decorators(decorator_list);
 

vm/src/pyobject.rs

@@ -634,6 +634,15 @@ impl PyFuncArgs {
     pub fn shift(&mut self) -> PyObjectRef {
         self.args.remove(0)
     }
+
+    pub fn get_kwarg(&self, key: &str, default: PyObjectRef) -> PyObjectRef {
+        for (arg_name, arg_value) in self.kwargs.iter() {
+            if arg_name == key {
+                return arg_value.clone();
+            }
+        }
+        default.clone()
+    }
 }
 
 type RustPyFunc = fn(vm: &mut VirtualMachine, PyFuncArgs) -> PyResult;