Add CodegenApplicabilityCheckerExtension and use it to fallback to Heavy LigthClasses

+ Fixed #KT-33584

compiler/frontend/src/org/jetbrains/kotlin/extensions/AnnotationBasedExtension.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.annotationClass
 import org.jetbrains.kotlin.types.TypeUtils
 
 interface AnnotationBasedExtension {
+
     fun getAnnotationFqNames(modifierListOwner: KtModifierListOwner?): List<String>
 
     fun DeclarationDescriptor.hasSpecialAnnotation(modifierListOwner: KtModifierListOwner?): Boolean {

compiler/frontend/src/org/jetbrains/kotlin/extensions/LightClassApplicabilityCheckExtension.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2010-2019 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.extensions
+
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.psi.KtDeclaration
+
+enum class LightClassApplicabilityType {
+    LightClass,
+    UltraLightClass
+}
+
+/**
+ * This extension point needs to be implemented by the Kotlin compiler plugins in case they change the requested declaration (i.e. producing synthetic parts)
+ * with backend extension points. The light class provider will request this EP to check either to create LightClass or UltraLight class implementations.
+ * @see org.jetbrains.kotlin.extensions.DeclarationAttributeAltererExtension
+ * @see org.jetbrains.kotlin.codegen.extensions.ExpressionCodegenExtension
+ */
+interface LightClassApplicabilityCheckExtension {
+    companion object : ProjectExtensionDescriptor<LightClassApplicabilityCheckExtension>(
+        "org.jetbrains.kotlin.lightClassApplicabilityCheckExtension",
+        LightClassApplicabilityCheckExtension::class.java
+    )
+
+    /**
+     * This method should return LightClass if any changes in Kotlin declarations is going to be produced during JVM-backend code generation.
+     * This method ought to be as fast as possible but never return UltraLightClass when not sure.
+     * Next advice could be given to make best:
+     * 1) Try to cover as much cases as possible without forcing descriptor evaluation
+     * 2) After you've forced descriptor evaluation, ideally, you should never return LightClass while in fact no synthetic parts going to be generated
+     * 3) So, you should force descriptor evaluation only if you're sure that you will be able to return UltraLightClass significantly more often
+     * @see org.jetbrains.kotlin.noarg.ide.IdeNoArgApplicabilityExtension
+     * @see org.jetbrains.kotlin.android.parcel.IDEParcelableApplicabilityExtension
+     */
+    fun checkApplicabilityType(declaration: KtDeclaration, descriptor: Lazy<DeclarationDescriptor?>): LightClassApplicabilityType
+}