Android extensions: Do not cache ViewStub widgets, do not cast it automatically

plugins/android-compiler-plugin/src/org/jetbrains/kotlin/android/synthetic/AndroidConst.kt

@@ -16,8 +16,6 @@
 
 package org.jetbrains.kotlin.android.synthetic
 
-import org.jetbrains.kotlin.lexer.KtKeywordToken
-import org.jetbrains.kotlin.lexer.KtTokens
 
 public object AndroidConst {
     val SYNTHETIC_PACKAGE: String = "kotlinx.android.synthetic"
@@ -44,6 +42,8 @@ public object AndroidConst {
     //TODO FqName / ClassId
 
     val VIEW_FQNAME = "android.view.View"
+    val VIEWSTUB_FQNAME = "android.view.ViewStub"
+
     val ACTIVITY_FQNAME = "android.app.Activity"
     val FRAGMENT_FQNAME = "android.app.Fragment"
     val SUPPORT_V4_PACKAGE = "android.support.v4"

plugins/android-compiler-plugin/src/org/jetbrains/kotlin/android/synthetic/codegen/AndroidExpressionCodegenExtension.kt

@@ -93,7 +93,13 @@ public class AndroidExpressionCodegenExtension : ExpressionCodegenExtension {
         val CLEAR_CACHE_METHOD_NAME = "_\$_clearFindViewByIdCache"
         val ON_DESTROY_METHOD_NAME = "onDestroyView"
 
-        fun isCacheSupported(descriptor: ClassifierDescriptor) = descriptor.source is KotlinSourceElement
+        fun isCacheSupported(receiverDescriptor: ClassDescriptor, descriptor: PropertyDescriptor? = null): Boolean {
+            val receiverIsKotlinClass = receiverDescriptor.source is KotlinSourceElement
+            return receiverIsKotlinClass && when (descriptor) {
+                is AndroidSyntheticProperty -> !descriptor.alwaysCastToView
+                else -> true
+            }
+        }
     }
 
     private class SyntheticPartsGenerateContext(
@@ -123,21 +129,21 @@ public class AndroidExpressionCodegenExtension : ExpressionCodegenExtension {
             receiver: StackValue,
             resolvedCall: ResolvedCall<*>,
             c: ExpressionCodegenExtension.Context,
-            descriptor: FunctionDescriptor
+            functionDescriptor: FunctionDescriptor
     ): StackValue? {
-        if (descriptor !is AndroidSyntheticFunction) return null
+        if (functionDescriptor !is AndroidSyntheticFunction) return null
-        if (descriptor.name.asString() != AndroidConst.CLEAR_FUNCTION_NAME) return null
+        if (functionDescriptor.name.asString() != AndroidConst.CLEAR_FUNCTION_NAME) return null
 
-        val declarationDescriptor = resolvedCall.getReceiverDeclarationDescriptor() ?: return null
+        val receiverDescriptor = resolvedCall.getReceiverDeclarationDescriptor() as? ClassDescriptor ?: return null
-        if (!isCacheSupported(declarationDescriptor)) return StackValue.functionCall(Type.VOID_TYPE) {}
+        if (!isCacheSupported(receiverDescriptor)) return StackValue.functionCall(Type.VOID_TYPE) {}
 
-        val androidClassType = AndroidClassType.getClassType(declarationDescriptor)
+        val androidClassType = AndroidClassType.getClassType(receiverDescriptor)
         if (androidClassType == AndroidClassType.UNKNOWN) return null
 
         return StackValue.functionCall(Type.VOID_TYPE) {
-            val bytecodeClassName = c.typeMapper.mapType(declarationDescriptor).internalName
+            val bytecodeClassName = c.typeMapper.mapType(receiverDescriptor).internalName
 
-            receiver.put(c.typeMapper.mapType(declarationDescriptor), it)
+            receiver.put(c.typeMapper.mapType(receiverDescriptor), it)
             it.invokevirtual(bytecodeClassName, CLEAR_CACHE_METHOD_NAME, "()V", false)
         }
     }
@@ -151,31 +157,31 @@ public class AndroidExpressionCodegenExtension : ExpressionCodegenExtension {
         if (descriptor !is AndroidSyntheticProperty) return null
         val packageFragment = descriptor.containingDeclaration as? AndroidSyntheticPackageFragmentDescriptor ?: return null
         val androidPackage = packageFragment.packageData.moduleData.module.applicationPackage
-        val declarationDescriptor = resolvedCall.getReceiverDeclarationDescriptor() ?: return null
+        val receiverDescriptor = resolvedCall.getReceiverDeclarationDescriptor() as? ClassDescriptor ?: return null
-        val androidClassType = AndroidClassType.getClassType(declarationDescriptor)
+        val androidClassType = AndroidClassType.getClassType(receiverDescriptor)
 
-        return SyntheticProperty(receiver, c.typeMapper, descriptor, declarationDescriptor, androidClassType, androidPackage)
+        return SyntheticProperty(receiver, c.typeMapper, descriptor, receiverDescriptor, androidClassType, androidPackage)
     }
 
     private class SyntheticProperty(
             val receiver: StackValue,
             val typeMapper: JetTypeMapper,
-            val descriptor: PropertyDescriptor,
+            val propertyDescriptor: PropertyDescriptor,
-            val declarationDescriptor: ClassifierDescriptor,
+            val receiverDescriptor: ClassDescriptor,
             val androidClassType: AndroidClassType,
             val androidPackage: String
-    ) : StackValue(typeMapper.mapType(descriptor.returnType!!)) {
+    ) : StackValue(typeMapper.mapType(propertyDescriptor.returnType!!)) {
 
         override fun putSelector(type: Type, v: InstructionAdapter) {
-            val returnTypeString = typeMapper.mapType(descriptor.type.lowerIfFlexible()).className
+            val returnTypeString = typeMapper.mapType(propertyDescriptor.type.lowerIfFlexible()).className
             if (AndroidConst.FRAGMENT_FQNAME == returnTypeString || AndroidConst.SUPPORT_FRAGMENT_FQNAME == returnTypeString) {
                 return putSelectorForFragment(v)
             }
 
-            if (androidClassType.supportsCache && isCacheSupported(declarationDescriptor)) {
+            if (androidClassType.supportsCache && isCacheSupported(receiverDescriptor, propertyDescriptor)) {
-                val declarationDescriptorType = typeMapper.mapType(declarationDescriptor)
+                val declarationDescriptorType = typeMapper.mapType(receiverDescriptor)
                 receiver.put(declarationDescriptorType, v)
-                v.getstatic(androidPackage.replace(".", "/") + "/R\$id", descriptor.name.asString(), "I")
+                v.getstatic(androidPackage.replace(".", "/") + "/R\$id", propertyDescriptor.name.asString(), "I")
                 v.invokevirtual(declarationDescriptorType.internalName, CACHED_FIND_VIEW_BY_ID_METHOD_NAME, "(I)Landroid/view/View;", false)
             }
             else {
@@ -224,7 +230,7 @@ public class AndroidExpressionCodegenExtension : ExpressionCodegenExtension {
         }
 
         fun getResourceId(v: InstructionAdapter) {
-            v.getstatic(androidPackage.replace(".", "/") + "/R\$id", descriptor.name.asString(), "I")
+            v.getstatic(androidPackage.replace(".", "/") + "/R\$id", propertyDescriptor.name.asString(), "I")
         }
     }
 

plugins/android-compiler-plugin/src/org/jetbrains/kotlin/android/synthetic/descriptors/AndroidSyntheticPackageFragmentDescriptor.kt

@@ -66,7 +66,7 @@ class AndroidSyntheticPackageFragmentDescriptor(
                     }
                     is AndroidResource.Fragment -> if (!packageData.forView) {
                         for ((receiverType, type) in fragmentTypes) {
-                            properties += genPropertyForFragment(packageFragmentDescriptor, receiverType, type, resource)
+                            properties += genPropertyForFragment(packageFragmentDescriptor, receiverType, type, resource, context)
                         }
                     }
                 }

plugins/android-compiler-plugin/src/org/jetbrains/kotlin/android/synthetic/res/syntheticDescriptorGeneration.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.descriptors.impl.PropertyGetterDescriptorImpl
 import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameUnsafe
 import org.jetbrains.kotlin.resolve.source.PsiSourceElement
 import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.typeUtil.makeNullable
@@ -65,17 +66,18 @@ internal fun genPropertyForWidget(
                                   defaultType.constructor.parameters.map { StarProjectionImpl(it) })
     } ?: context.viewType
 
-    return genProperty(resolvedWidget.widget.id, receiverType, type, packageFragmentDescriptor, sourceEl, resolvedWidget.errorType)
+    return genProperty(resolvedWidget.widget.id, receiverType, type, packageFragmentDescriptor, sourceEl, context, resolvedWidget.errorType)
 }
 
 internal fun genPropertyForFragment(
         packageFragmentDescriptor: PackageFragmentDescriptor,
         receiverType: KotlinType,
         type: KotlinType,
-        fragment: AndroidResource.Fragment
+        fragment: AndroidResource.Fragment,
+        context: SyntheticElementResolveContext
 ): PropertyDescriptor {
     val sourceElement = fragment.sourceElement?.let { XmlSourceElement(it) } ?: SourceElement.NO_SOURCE
-    return genProperty(fragment.id, receiverType, type, packageFragmentDescriptor, sourceElement, null)
+    return genProperty(fragment.id, receiverType, type, packageFragmentDescriptor, sourceElement, context, null)
 }
 
 private fun genProperty(
@@ -84,8 +86,11 @@ private fun genProperty(
         type: KotlinType,
         containingDeclaration: DeclarationDescriptor,
         sourceElement: SourceElement,
+        context: SyntheticElementResolveContext,
         errorType: String?
 ): PropertyDescriptor {
+    val alwaysCastToView = type.constructor.declarationDescriptor?.fqNameUnsafe?.asString() == AndroidConst.VIEWSTUB_FQNAME
+
     val property = object : AndroidSyntheticProperty, PropertyDescriptorImpl(
             containingDeclaration,
             null,
@@ -99,9 +104,11 @@ private fun genProperty(
             false,
             false) {
         override val errorType = errorType
+        override val alwaysCastToView = alwaysCastToView
     }
 
-    val flexibleType = DelegatingFlexibleType.create(type, type.makeNullable(), FlexibleTypeCapabilities.NONE)
+    val actualType = if (alwaysCastToView) context.viewType else type
+    val flexibleType = DelegatingFlexibleType.create(actualType, actualType.makeNullable(), FlexibleTypeCapabilities.NONE)
     property.setType(
             flexibleType,
             emptyList<TypeParameterDescriptor>(),
@@ -131,6 +138,7 @@ interface AndroidSyntheticFunction
 
 interface AndroidSyntheticProperty {
     val errorType: String?
+    val alwaysCastToView: Boolean
 
     val isErrorType: Boolean
         get() = errorType != null

plugins/android-compiler-plugin/testData/codegen/bytecodeShape/viewStub/res/layout/layout.xml

@@ -0,0 +1,10 @@
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+             android:layout_width="match_parent"
+             android:layout_height="match_parent" >
+
+    <ViewStub
+        android:id="@+id/stub"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content" />
+
+</FrameLayout>

plugins/android-compiler-plugin/testData/codegen/bytecodeShape/viewStub/viewStub.kt

@@ -0,0 +1,18 @@
+package test
+
+import android.app.Activity
+import android.os.Bundle
+import java.io.File
+import kotlinx.android.synthetic.main.layout.*
+
+public class MyActivity : Activity() {
+    fun test() {
+        stub
+    }
+}
+
+// 1 GETSTATIC test/R\$id\.stub
+// 0 INVOKEVIRTUAL test/MyActivity\._\$_findCachedViewById
+// 1 INVOKEVIRTUAL android/app/Activity\.findViewById
+// 0 CHECKCAST android/view/ViewStub
+// 2 CHECKCAST android/view/View

plugins/android-compiler-plugin/testData/descriptors/viewStub/res/layout/test.xml

@@ -0,0 +1,11 @@
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+             xmlns:tools="http://schemas.android.com/tools"
+             android:layout_width="match_parent"
+             android:layout_height="match_parent" >
+
+    <ViewStub
+        android:id="@+id/stub"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content" />
+
+</FrameLayout>

plugins/android-compiler-plugin/testData/descriptors/viewStub/result.txt

@@ -0,0 +1,35 @@
+kotlinx
+
+
+kotlinx.android
+
+
+kotlinx.android.synthetic
+
+    public fun android.app.Activity.clearFindViewByIdCache(): kotlin.Unit
+    public fun android.app.Fragment.clearFindViewByIdCache(): kotlin.Unit
+
+
+kotlinx.android.synthetic.main
+
+
+kotlinx.android.synthetic.main.test
+
+    public val android.app.Activity.stub: android.view.View!
+    public val android.app.Fragment.stub: android.view.View!
+
+
+kotlinx.android.synthetic.main.test.view
+
+    public val android.view.View.stub: android.view.View!
+
+
+kotlinx.android.synthetic.test
+
+    public val android.app.Activity.stub: android.view.View!
+    public val android.app.Fragment.stub: android.view.View!
+
+
+kotlinx.android.synthetic.test.view
+
+    public val android.view.View.stub: android.view.View!

plugins/android-compiler-plugin/tests/org/jetbrains/kotlin/lang/resolve/android/test/AndroidBytecodeShapeTestGenerated.java

@@ -160,4 +160,10 @@ public class AndroidBytecodeShapeTestGenerated extends AbstractAndroidBytecodeSh
         String fileName = KotlinTestUtils.navigationMetadata("plugins/android-compiler-plugin/testData/codegen/bytecodeShape/supportSimpleFragmentProperty/");
         doTest(fileName);
     }
+
+    @TestMetadata("viewStub")
+    public void testViewStub() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("plugins/android-compiler-plugin/testData/codegen/bytecodeShape/viewStub/");
+        doTest(fileName);
+    }
 }

plugins/android-compiler-plugin/tests/org/jetbrains/kotlin/lang/resolve/android/test/AndroidSyntheticPropertyDescriptorTestGenerated.java

@@ -118,4 +118,10 @@ public class AndroidSyntheticPropertyDescriptorTestGenerated extends AbstractAnd
         String fileName = KotlinTestUtils.navigationMetadata("plugins/android-compiler-plugin/testData/descriptors/unresolvedWidget/");
         doTest(fileName);
     }
+
+    @TestMetadata("viewStub")
+    public void testViewStub() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("plugins/android-compiler-plugin/testData/descriptors/viewStub/");
+        doTest(fileName);
+    }
 }