Introduction of CastedClassReceiver and its handling in codegen #KT-6744 Fixed

ClassReceiver converted to Kotlin
Also #KT-7617 Fixed

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

@@ -359,7 +359,7 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
 
     @Override
     public StackValue visitSuperExpression(@NotNull KtSuperExpression expression, StackValue data) {
-        return StackValue.thisOrOuter(this, getSuperCallLabelTarget(context, expression), true, true);
+        return StackValue.thisOrOuter(this, getSuperCallLabelTarget(context, expression), true, false);
     }
 
     @NotNull
@@ -2572,7 +2572,8 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
                 }
             }
             else {
-                return StackValue.thisOrOuter(this, receiverDescriptor, isSuper, isEnumEntry(receiverDescriptor));
+                return StackValue.thisOrOuter(this, receiverDescriptor, isSuper,
+                                              receiverValue instanceof CastClassReceiver || isEnumEntry(receiverDescriptor));
             }
         }
         else if (receiverValue instanceof ScriptReceiver) {

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

@@ -460,11 +460,11 @@ public abstract class StackValue {
             @NotNull ExpressionCodegen codegen,
             @NotNull ClassDescriptor descriptor,
             boolean isSuper,
-            boolean isExplicit
+            boolean castReceiver
     ) {
-        // Coerce explicit 'this' for the case when it is smart cast.
+        // Coerce 'this' for the case when it is smart cast.
         // Do not coerce for other cases due to the 'protected' access issues (JVMS 7, 4.9.2 Structural Constraints).
-        boolean coerceType = descriptor.getKind() == ClassKind.INTERFACE || (isExplicit && !isSuper);
+        boolean coerceType = descriptor.getKind() == ClassKind.INTERFACE || (castReceiver && !isSuper);
         return new ThisOuter(codegen, descriptor, isSuper, coerceType);
     }
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tasks/TaskPrioritizer.kt

@@ -37,6 +37,8 @@ import org.jetbrains.kotlin.resolve.calls.util.FakeCallableDescriptorForObject
 import org.jetbrains.kotlin.resolve.descriptorUtil.hasLowPriorityInOverloadResolution
 import org.jetbrains.kotlin.resolve.scopes.ImportingScope
 import org.jetbrains.kotlin.resolve.scopes.LexicalScope
+import org.jetbrains.kotlin.resolve.scopes.receivers.CastClassReceiver
+import org.jetbrains.kotlin.resolve.scopes.receivers.ClassReceiver
 import org.jetbrains.kotlin.resolve.scopes.receivers.QualifierReceiver
 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue
 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue.NO_RECEIVER
@@ -234,9 +236,16 @@ public class TaskPrioritizer(
                     }
                     val filteredMembers = if (filter == null) membersForThisVariant else membersForThisVariant.filter(filter)
 
+                    val dispatchReceiver =
+                            if (explicitReceiver.value is ClassReceiver && type != explicitReceiver.value.type) {
+                                CastClassReceiver(explicitReceiver.value.declarationDescriptor, type)
+                            }
+                            else {
+                                explicitReceiver.value
+                            }
                     convertWithReceivers(
                             filteredMembers,
-                            explicitReceiver.value,
+                            dispatchReceiver,
                             NO_RECEIVER,
                             members,
                             createKind(DISPATCH_RECEIVER, isExplicit),

compiler/testData/codegen/box/smartCasts/falseSmartCast.kt

@@ -0,0 +1,17 @@
+open class SuperFoo {
+    public fun bar(): String {
+        if (this is Foo) {
+            superFoo() // Smart cast
+            return baz() // Cannot be cast
+        }
+        return baz()
+    }
+
+    public fun baz() = "OK"
+}
+
+class Foo : SuperFoo() {
+    public fun superFoo() {}
+}
+
+fun box(): String = Foo().bar()

compiler/testData/codegen/box/smartCasts/implicitExtensionReceiver.kt

@@ -0,0 +1,7 @@
+class A {
+    fun foo() = "OK"
+}
+
+fun A?.bar() = if (this != null) foo() else "FAIL"
+
+fun box() = A().bar()

compiler/testData/codegen/box/smartCasts/implicitMemberReceiver.kt

@@ -0,0 +1,20 @@
+open class A {
+    open val a = "OK"
+}
+
+class B : A() {
+    override val a = "FAIL"
+    fun foo() = "CRUSH"
+}
+
+class C {
+    fun A?.complex(): String {
+        if (this is B) return foo()
+        else if (this != null) return a
+        else return "???"
+    }
+
+    fun bar() = A().complex()
+}
+
+fun box() = C().bar()

compiler/testData/codegen/box/smartCasts/implicitReceiver.kt

@@ -0,0 +1,13 @@
+open class A {
+    class B : A() {
+        val a = "FAIL"
+    }
+
+    fun foo(): String {
+        if (this is B) return a
+        return "OK"
+    }
+}
+
+
+fun box(): String = A().foo()

compiler/testData/codegen/box/smartCasts/implicitReceiverInWhen.kt

@@ -0,0 +1,11 @@
+open class A {
+    fun f(): String =
+            when (this) {
+                is B -> x
+                else -> "FAIL"
+            }
+}
+
+class B(val x: String) : A()
+
+fun box() = B("OK").f()

compiler/testData/codegen/box/smartCasts/implicitToGrandSon.kt

@@ -0,0 +1,13 @@
+open class A {
+    open fun foo() = "FAIL"
+
+    fun bar() = if (this is C) foo() else foo()
+}
+
+open class B : A()
+
+open class C : B() {
+    override fun foo() = "OK"
+}
+
+fun box() = C().bar()

compiler/testData/codegen/bytecodeText/falseSmartCast.kt

@@ -0,0 +1,15 @@
+open class SuperFoo {
+    public fun bar() {
+        if (this is Foo) {
+            baz()
+        }
+    }
+
+    public fun baz() {}
+}
+
+class Foo : SuperFoo() 
+
+// 0 INVOKEVIRTUAL SuperFoo.baz
+// 1 CHECKCAST Foo
+// 1 INVOKEVIRTUAL Foo.baz

compiler/tests/org/jetbrains/kotlin/codegen/BytecodeTextTestGenerated.java

@@ -107,6 +107,12 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
         doTest(fileName);
     }
 
+    @TestMetadata("falseSmartCast.kt")
+    public void testFalseSmartCast() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/falseSmartCast.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("inlineFromOtherModule.kt")
     public void testInlineFromOtherModule() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/inlineFromOtherModule.kt");

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java

@@ -7274,6 +7274,51 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
         }
     }
 
+    @TestMetadata("compiler/testData/codegen/box/smartCasts")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class SmartCasts extends AbstractBlackBoxCodegenTest {
+        public void testAllFilesPresentInSmartCasts() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/smartCasts"), Pattern.compile("^(.+)\\.kt$"), true);
+        }
+
+        @TestMetadata("falseSmartCast.kt")
+        public void testFalseSmartCast() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/smartCasts/falseSmartCast.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("implicitExtensionReceiver.kt")
+        public void testImplicitExtensionReceiver() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/smartCasts/implicitExtensionReceiver.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("implicitMemberReceiver.kt")
+        public void testImplicitMemberReceiver() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/smartCasts/implicitMemberReceiver.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("implicitReceiver.kt")
+        public void testImplicitReceiver() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/smartCasts/implicitReceiver.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("implicitReceiverInWhen.kt")
+        public void testImplicitReceiverInWhen() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/smartCasts/implicitReceiverInWhen.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("implicitToGrandSon.kt")
+        public void testImplicitToGrandSon() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/smartCasts/implicitToGrandSon.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("compiler/testData/codegen/box/staticFields")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/receivers/CastClassReceiver.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.resolve.scopes.receivers
+
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.types.KotlinType
+
+class CastClassReceiver(originalDescriptor: ClassDescriptor, val targetType: KotlinType) : ClassReceiver(originalDescriptor)

core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/receivers/ClassReceiver.java

@@ -1,52 +0,0 @@
-/*
- * Copyright 2010-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.kotlin.resolve.scopes.receivers;
-
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.kotlin.descriptors.ClassDescriptor;
-import org.jetbrains.kotlin.types.KotlinType;
-
-public class ClassReceiver implements ThisReceiver {
-
-    private final ClassDescriptor classDescriptor;
-
-    public ClassReceiver(@NotNull ClassDescriptor classDescriptor) {
-        this.classDescriptor = classDescriptor;
-    }
-
-    @Override
-    public boolean exists() {
-        return true;
-    }
-
-    @NotNull
-    @Override
-    public KotlinType getType() {
-        return classDescriptor.getDefaultType();
-    }
-
-    @NotNull
-    @Override
-    public ClassDescriptor getDeclarationDescriptor() {
-        return classDescriptor;
-    }
-
-    @Override
-    public String toString() {
-        return "Class{" + getType() + "}";
-    }
-}

core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/receivers/ClassReceiver.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.resolve.scopes.receivers
+
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+
+open class ClassReceiver(private val classDescriptor: ClassDescriptor) : ThisReceiver {
+
+    override fun exists() = true
+
+    override fun getType() = classDescriptor.defaultType
+
+    override fun getDeclarationDescriptor() = classDescriptor
+
+    override fun equals(other: Any?) = classDescriptor == (other as? ClassReceiver)?.classDescriptor
+
+    override fun hashCode() = classDescriptor.hashCode()
+
+    override fun toString() = "Class{$type}"
+}