Support class literals (A::class)

compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java

@@ -30,11 +30,11 @@ import kotlin.KotlinPackage;
 import kotlin.Unit;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.kotlin.codegen.extensions.ExpressionCodegenExtension;
 import org.jetbrains.kotlin.backend.common.CodegenUtil;
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
 import org.jetbrains.kotlin.codegen.binding.CalculatedClosure;
 import org.jetbrains.kotlin.codegen.context.*;
+import org.jetbrains.kotlin.codegen.extensions.ExpressionCodegenExtension;
 import org.jetbrains.kotlin.codegen.inline.*;
 import org.jetbrains.kotlin.codegen.intrinsics.IntrinsicMethod;
 import org.jetbrains.kotlin.codegen.intrinsics.IntrinsicMethods;
@@ -2610,6 +2610,20 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
         return lookupLocalIndex(declarationDescriptor);
     }
 
+    @Override
+    public StackValue visitClassLiteralExpression(@NotNull JetClassLiteralExpression expression, StackValue data) {
+        JetType type = bindingContext.get(EXPRESSION_TYPE, expression);
+        assert type != null;
+
+        assert state.getReflectionTypes().getkClass().getTypeConstructor().equals(type.getConstructor())
+                : "::class expression should be type checked to a KClass: " + type;
+
+        ClassifierDescriptor typeArgument = KotlinPackage.single(type.getArguments()).getType().getConstructor().getDeclarationDescriptor();
+        assert typeArgument instanceof ClassDescriptor : "KClass argument should be a class: " + typeArgument;
+
+        return generateClassLiteralReference((ClassDescriptor) typeArgument);
+    }
+
     @Override
     public StackValue visitCallableReferenceExpression(@NotNull JetCallableReferenceExpression expression, StackValue data) {
         ResolvedCall<?> resolvedCall = getResolvedCallWithAssert(expression.getCallableReference(), bindingContext);
@@ -2690,10 +2704,22 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
             @Override
             public Unit invoke(InstructionAdapter v) {
                 v.visitLdcInsn(descriptor.getName().asString());
+                StackValue receiverClass = generateClassLiteralReference(containingClass);
+                receiverClass.put(receiverClass.type, v);
+                v.invokestatic(REFLECTION, factoryMethod.getName(), factoryMethod.getDescriptor(), false);
 
-                Type classAsmType = typeMapper.mapClass(containingClass);
+                return Unit.INSTANCE$;
+            }
+        });
+    }
 
-                if (containingClass instanceof JavaClassDescriptor) {
+    @NotNull
+    private StackValue generateClassLiteralReference(@NotNull final ClassDescriptor descriptor) {
+        return StackValue.operation(K_CLASS_TYPE, new Function1<InstructionAdapter, Unit>() {
+            @Override
+            public Unit invoke(InstructionAdapter v) {
+                Type classAsmType = typeMapper.mapClass(descriptor);
+                if (descriptor instanceof JavaClassDescriptor) {
                     v.aconst(classAsmType);
                     v.invokestatic(REFLECTION, "foreignKotlinClass", Type.getMethodDescriptor(K_CLASS_TYPE, getType(Class.class)), false);
                 }
@@ -2701,8 +2727,6 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
                     v.getstatic(classAsmType.getInternalName(), JvmAbi.KOTLIN_CLASS_FIELD_NAME, K_CLASS_TYPE.getDescriptor());
                 }
 
-                v.invokestatic(REFLECTION, factoryMethod.getName(), factoryMethod.getDescriptor(), false);
-
                 return Unit.INSTANCE$;
             }
         });

compiler/backend/src/org/jetbrains/kotlin/codegen/state/GenerationState.java

@@ -117,6 +117,8 @@ public class GenerationState {
     @Nullable
     private List<ScriptDescriptor> earlierScriptsForReplInterpreter;
 
+    private final ReflectionTypes reflectionTypes;
+
     private final JvmRuntimeTypes runtimeTypes;
 
     @NotNull
@@ -187,7 +189,7 @@ public class GenerationState {
         this.disableParamAssertions = disableParamAssertions;
         this.generateClassFilter = generateClassFilter;
 
-        ReflectionTypes reflectionTypes = new ReflectionTypes(module);
+        this.reflectionTypes = new ReflectionTypes(module);
         this.runtimeTypes = new JvmRuntimeTypes(reflectionTypes);
     }
 
@@ -259,6 +261,11 @@ public class GenerationState {
         return generateClassFilter;
     }
 
+    @NotNull
+    public ReflectionTypes getReflectionTypes() {
+        return reflectionTypes;
+    }
+
     @NotNull
     public JvmRuntimeTypes getJvmRuntimeTypes() {
         return runtimeTypes;