[KAPT] Fix stub generation for anonymous delegates

Replace anonymous classes with superclass in delegate properties
#KT-34838 Fixed

plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/KaptAnonymousTypeTransformer.kt

@@ -5,17 +5,12 @@
 
 package org.jetbrains.kotlin.kapt3
 
-import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptorWithVisibility
+import org.jetbrains.kotlin.kapt3.util.replaceAnonymousTypeWithSuperType
 import org.jetbrains.kotlin.resolve.DeclarationSignatureAnonymousTypeTransformer
-import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.resolve.DescriptorUtils.isLocal
-import org.jetbrains.kotlin.resolve.DescriptorUtils.*
 import org.jetbrains.kotlin.resolve.jvm.extensions.PartialAnalysisHandlerExtension
 import org.jetbrains.kotlin.types.KotlinType
-import org.jetbrains.kotlin.types.TypeProjectionImpl
-import org.jetbrains.kotlin.types.replace
-import org.jetbrains.kotlin.types.typeUtil.builtIns
 
 class KaptAnonymousTypeTransformer(
     private val analysisExtension: PartialAnalysisHandlerExtension
@@ -29,46 +24,6 @@ class KaptAnonymousTypeTransformer(
             return type
         }
 
-        return convertPossiblyAnonymousType(type)
+        return replaceAnonymousTypeWithSuperType(type)
     }
-}
-
-internal fun convertPossiblyAnonymousType(type: KotlinType): KotlinType {
-    val declaration = type.constructor.declarationDescriptor as? ClassDescriptor ?: return type
-
-    if (KotlinBuiltIns.isArray(type)) {
-        val elementTypeProjection = type.arguments.singleOrNull()
-        if (elementTypeProjection != null && !elementTypeProjection.isStarProjection) {
-            return type.builtIns.getArrayType(
-                elementTypeProjection.projectionKind,
-                convertPossiblyAnonymousType(elementTypeProjection.type)
-            )
-        }
-    }
-
-    val actualType = when {
-        isAnonymousObject(declaration) || DescriptorUtils.isLocal(declaration) -> {
-            if (type.constructor.supertypes.size == 1) {
-                convertPossiblyAnonymousType(type.constructor.supertypes.iterator().next())
-            } else {
-                /*
-                    Frontend reports an error on public properties in this case,
-                    but we ignore errors when making stubs, so there should be a reasonable fallback.
-                 */
-                type.builtIns.anyType
-            }
-        }
-        else -> type
-    }
-
-    if (actualType.arguments.isEmpty()) return actualType
-
-    val arguments = actualType.arguments.map { typeArg ->
-        if (typeArg.isStarProjection)
-            return@map typeArg
-
-        TypeProjectionImpl(typeArg.projectionKind, convertPossiblyAnonymousType(typeArg.type))
-    }
-
-    return actualType.replace(newArguments = arguments)
 }

plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/stubs/ClassFileToSourceStubConverter.kt

@@ -49,6 +49,7 @@ import org.jetbrains.kotlin.kapt3.stubs.ErrorTypeCorrector.TypeKind.METHOD_PARAM
 import org.jetbrains.kotlin.kapt3.stubs.ErrorTypeCorrector.TypeKind.RETURN_TYPE
 import org.jetbrains.kotlin.kapt3.util.*
 import org.jetbrains.kotlin.load.java.sources.JavaSourceElement
+import org.jetbrains.kotlin.load.kotlin.TypeMappingMode
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
@@ -62,6 +63,7 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameOrNull
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperClassOrAny
 import org.jetbrains.kotlin.resolve.descriptorUtil.isCompanionObject
+import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOrigin
 import org.jetbrains.kotlin.resolve.source.PsiSourceElement
 import org.jetbrains.kotlin.types.ErrorUtils
 import org.jetbrains.kotlin.types.KotlinType
@@ -690,7 +692,8 @@ class ClassFileToSourceStubConverter(val kaptContext: KaptContextForStubGenerati
         val name = field.name
         if (!isValidIdentifier(name)) return null
 
-        val type = Type.getType(field.desc)
+        val type = getFieldType(field, origin)
+
         if (!checkIfValidTypeName(containingClass, type)) {
             return null
         }
@@ -1420,6 +1423,25 @@ class ClassFileToSourceStubConverter(val kaptContext: KaptContextForStubGenerati
         lineMappings.registerSignature(this, node)
         return this
     }
+
+    private fun getFieldType(field: FieldNode, origin: JvmDeclarationOrigin?): Type {
+        val fieldType = Type.getType(field.desc)
+        return when (val declaration = origin?.element) {
+            is KtProperty -> {
+                //replace anonymous type in delegate (if any)
+                val delegateType = kaptContext.bindingContext[BindingContext.EXPRESSION_TYPE_INFO, declaration.delegateExpression]?.type
+                delegateType?.let {
+                    val replaced = replaceAnonymousTypeWithSuperType(it)
+                    //not changed => not anonymous type => use type from field
+                    if (replaced != it) replaced else null
+                }?.let(::convertKotlinType) ?: fieldType
+            }
+            else -> fieldType
+        }
+    }
+
+    private fun convertKotlinType(type: KotlinType): Type = typeMapper.mapType(type, null, TypeMappingMode.GENERIC_ARGUMENT)
+
 }
 
 private fun Any?.isOfPrimitiveType(): Boolean = when (this) {

plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/util/typeUtils.kt

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.kapt3.util
+
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeProjectionImpl
+import org.jetbrains.kotlin.types.replace
+import org.jetbrains.kotlin.types.typeUtil.builtIns
+
+fun replaceAnonymousTypeWithSuperType(type: KotlinType): KotlinType {
+    val declaration = type.constructor.declarationDescriptor as? ClassDescriptor ?: return type
+
+    if (KotlinBuiltIns.isArray(type)) {
+        val elementTypeProjection = type.arguments.singleOrNull()
+        if (elementTypeProjection != null && !elementTypeProjection.isStarProjection) {
+            return type.builtIns.getArrayType(
+                elementTypeProjection.projectionKind,
+                replaceAnonymousTypeWithSuperType(elementTypeProjection.type)
+            )
+        }
+    }
+
+    val actualType = when {
+        DescriptorUtils.isAnonymousObject(declaration) || DescriptorUtils.isLocal(declaration) -> {
+            if (type.constructor.supertypes.size == 1) {
+                replaceAnonymousTypeWithSuperType(type.constructor.supertypes.iterator().next())
+            } else {
+                /*
+                    Frontend reports an error on public properties in this case,
+                    but we ignore errors when making stubs, so there should be a reasonable fallback.
+                 */
+                type.builtIns.anyType
+            }
+        }
+        else -> type
+    }
+
+    if (actualType.arguments.isEmpty()) return actualType
+
+    val arguments = actualType.arguments.map { typeArg ->
+        if (typeArg.isStarProjection)
+            return@map typeArg
+
+        TypeProjectionImpl(typeArg.projectionKind, replaceAnonymousTypeWithSuperType(typeArg.type))
+    }
+
+    return actualType.replace(newArguments = arguments)
+}

plugins/kapt3/kapt3-compiler/test/org/jetbrains/kotlin/kapt3/test/ClassFileToSourceStubConverterTestGenerated.java

@@ -69,6 +69,11 @@ public class ClassFileToSourceStubConverterTestGenerated extends AbstractClassFi
         runTest("plugins/kapt3/kapt3-compiler/testData/converter/annotationsWithTargets.kt");
     }
 
+    @TestMetadata("anonymousDelegate.kt")
+    public void testAnonymousDelegate() throws Exception {
+        runTest("plugins/kapt3/kapt3-compiler/testData/converter/anonymousDelegate.kt");
+    }
+
     @TestMetadata("comments.kt")
     public void testComments() throws Exception {
         runTest("plugins/kapt3/kapt3-compiler/testData/converter/comments.kt");

plugins/kapt3/kapt3-compiler/test/org/jetbrains/kotlin/kapt3/test/IrClassFileToSourceStubConverterTestGenerated.java

@@ -70,6 +70,11 @@ public class IrClassFileToSourceStubConverterTestGenerated extends AbstractIrCla
         runTest("plugins/kapt3/kapt3-compiler/testData/converter/annotationsWithTargets.kt");
     }
 
+    @TestMetadata("anonymousDelegate.kt")
+    public void testAnonymousDelegate() throws Exception {
+        runTest("plugins/kapt3/kapt3-compiler/testData/converter/anonymousDelegate.kt");
+    }
+
     @TestMetadata("comments.kt")
     public void testComments() throws Exception {
         runTest("plugins/kapt3/kapt3-compiler/testData/converter/comments.kt");

plugins/kapt3/kapt3-compiler/testData/converter/anonymousDelegate.kt

@@ -0,0 +1,34 @@
+import kotlin.reflect.KProperty
+
+class Test {
+
+    var broken by object {
+        operator fun getValue(obj: Test, property: KProperty<*>) = Any()
+
+        operator fun setValue(obj: Test, property: KProperty<*>, any: Any) {
+
+        }
+    }
+
+    var overridden by object : java.io.Serializable {
+        operator fun getValue(obj: Test, property: KProperty<*>) = Any()
+
+        operator fun setValue(obj: Test, property: KProperty<*>, any: Any) {
+
+        }
+    }
+
+    private val lazyProp by lazy {
+        object : Runnable {
+            override fun run() {}
+        }
+    }
+
+}
+
+var delegate by object {
+    operator fun getValue(nothing: Nothing?, property: KProperty<*>) = Any()
+    operator fun setValue(nothing: Nothing?, property: KProperty<*>, any: Any) {
+        //empty
+    }
+}

plugins/kapt3/kapt3-compiler/testData/converter/anonymousDelegate.txt

@@ -0,0 +1,60 @@
+import java.lang.System;
+
+@kotlin.Metadata()
+public final class AnonymousDelegateKt {
+
+    public AnonymousDelegateKt() {
+        super();
+    }
+    @org.jetbrains.annotations.NotNull()
+    private static final java.lang.Object delegate$delegate = null;
+
+    @org.jetbrains.annotations.NotNull()
+    public static final java.lang.Object getDelegate() {
+        return null;
+    }
+
+    public static final void setDelegate(@org.jetbrains.annotations.NotNull()
+    java.lang.Object p0) {
+    }
+}
+
+////////////////////
+
+
+import java.lang.System;
+
+@kotlin.Metadata()
+public final class Test {
+    @org.jetbrains.annotations.NotNull()
+    private final java.lang.Object broken$delegate = null;
+    @org.jetbrains.annotations.NotNull()
+    private final java.io.Serializable overridden$delegate = null;
+    private final kotlin.Lazy lazyProp$delegate = null;
+
+    public Test() {
+        super();
+    }
+
+    @org.jetbrains.annotations.NotNull()
+    public final java.lang.Object getBroken() {
+        return null;
+    }
+
+    public final void setBroken(@org.jetbrains.annotations.NotNull()
+    java.lang.Object p0) {
+    }
+
+    @org.jetbrains.annotations.NotNull()
+    public final java.lang.Object getOverridden() {
+        return null;
+    }
+
+    public final void setOverridden(@org.jetbrains.annotations.NotNull()
+    java.lang.Object p0) {
+    }
+
+    private final java.lang.Runnable getLazyProp() {
+        return null;
+    }
+}