[IR] [JVM_IR] Commonized SAM conversions lowering

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/SingleAbstractMethodLowering.kt

@@ -1,25 +1,19 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2020 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.backend.jvm.lower
+package org.jetbrains.kotlin.backend.common.lower
 
+import org.jetbrains.kotlin.backend.common.CommonBackendContext
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext
 import org.jetbrains.kotlin.backend.common.ir.copyTo
 import org.jetbrains.kotlin.backend.common.ir.createImplicitParameterDeclarationWithWrappedDescriptor
-import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
-import org.jetbrains.kotlin.backend.common.lower.irBlock
-import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
-import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
-import org.jetbrains.kotlin.backend.jvm.JvmLoweredDeclarationOrigin
-import org.jetbrains.kotlin.backend.jvm.ir.erasedUpperBound
-import org.jetbrains.kotlin.codegen.SamWrapperCodegen.FUNCTION_FIELD_NAME
-import org.jetbrains.kotlin.codegen.SamWrapperCodegen.SAM_WRAPPER_SUFFIX
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
+import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.builders.*
 import org.jetbrains.kotlin.ir.builders.declarations.*
@@ -37,17 +31,10 @@ import org.jetbrains.kotlin.ir.types.classifierOrFail
 import org.jetbrains.kotlin.ir.types.isNullable
 import org.jetbrains.kotlin.ir.types.makeNullable
 import org.jetbrains.kotlin.ir.util.*
-import org.jetbrains.kotlin.load.java.JavaVisibilities
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.util.OperatorNameConventions
 
-internal val singleAbstractMethodPhase = makeIrFilePhase(
+abstract class SingleAbstractMethodLowering(val context: CommonBackendContext) : FileLoweringPass, IrElementTransformerVoidWithContext() {
-    ::SingleAbstractMethodLowering,
-    name = "SingleAbstractMethod",
-    description = "Replace SAM conversions with instances of interface-implementing classes"
-)
-
-class SingleAbstractMethodLowering(val context: JvmBackendContext) : FileLoweringPass, IrElementTransformerVoidWithContext() {
     // SAM wrappers are cached, either in the file class (if it exists), or in a top-level enclosing class.
     // In the latter case, the names of SAM wrappers depend on the order of classes in the file. For example:
     //
@@ -75,6 +62,11 @@ class SingleAbstractMethodLowering(val context: JvmBackendContext) : FileLowerin
     private val inlineCachedImplementations = mutableMapOf<IrType, IrClass>()
     private var enclosingClass: IrClass? = null
 
+    open val privateGeneratedWrapperVisibility: Visibility
+        get() = Visibilities.PRIVATE
+
+    abstract fun getSuperTypeForWrapper(typeOperand: IrType): IrType
+
     override fun lower(irFile: IrFile) {
         enclosingClass = irFile.declarations.filterIsInstance<IrClass>().find { it.origin == IrDeclarationOrigin.FILE_CLASS }
         irFile.transformChildrenVoid()
@@ -99,7 +91,7 @@ class SingleAbstractMethodLowering(val context: JvmBackendContext) : FileLowerin
         // TODO: there must be exactly one wrapper per Java interface; ideally, if the interface has generic
         //       parameters, so should the wrapper. Currently, we just erase them and generate something that
         //       erases to the same result at codegen time.
-        val erasedSuperType = expression.typeOperand.erasedUpperBound.defaultType
+        val erasedSuperType = getSuperTypeForWrapper(expression.typeOperand)
         val superType = if (expression.typeOperand.isNullable()) erasedSuperType.makeNullable() else erasedSuperType
         val invokable = expression.argument.transform(this, null)
         context.createIrBuilder(currentScope!!.scope.scopeOwnerSymbol).apply {
@@ -136,6 +128,9 @@ class SingleAbstractMethodLowering(val context: JvmBackendContext) : FileLowerin
         }
     }
 
+    private val SAM_WRAPPER_SUFFIX = "$0"
+    private val FUNCTION_FIELD_NAME = "function"
+
     // Construct a class that wraps an invokable object into an implementation of an interface:
     //     class sam$n(private val invokable: F) : Interface { override fun method(...) = invokable(...) }
     private fun createObjectProxy(superType: IrType, generatePublicWrapper: Boolean): IrClass {
@@ -153,10 +148,10 @@ class SingleAbstractMethodLowering(val context: JvmBackendContext) : FileLowerin
         val wrappedFunctionClass = context.ir.symbols.functionN(superMethod.valueParameters.size).owner
         val wrappedFunctionType = wrappedFunctionClass.defaultType
 
-        val wrapperVisibility = if (generatePublicWrapper) Visibilities.PUBLIC else JavaVisibilities.PACKAGE_VISIBILITY
+        val wrapperVisibility = if (generatePublicWrapper) Visibilities.PUBLIC else privateGeneratedWrapperVisibility
         val subclass = buildClass {
             name = wrapperName
-            origin = JvmLoweredDeclarationOrigin.GENERATED_SAM_IMPLEMENTATION
+            origin = IrDeclarationOrigin.GENERATED_SAM_IMPLEMENTATION
             visibility = wrapperVisibility
         }.apply {
             createImplicitParameterDeclarationWithWrappedDescriptor()

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/DeclarationOrigins.kt

@@ -27,7 +27,6 @@ interface JvmLoweredDeclarationOrigin : IrDeclarationOrigin {
     object SYNTHETIC_METHOD_FOR_TYPEALIAS_ANNOTATIONS :
         IrDeclarationOriginImpl("SYNTHETIC_METHOD_FOR_TYPEALIAS_ANNOTATIONS", isSynthetic = true)
     object GENERATED_PROPERTY_REFERENCE : IrDeclarationOriginImpl("GENERATED_PROPERTY_REFERENCE", isSynthetic = true)
-    object GENERATED_SAM_IMPLEMENTATION : IrDeclarationOriginImpl("GENERATED_SAM_IMPLEMENTATION", isSynthetic = true)
     object GENERATED_MEMBER_IN_CALLABLE_REFERENCE : IrDeclarationOriginImpl("GENERATED_MEMBER_IN_CALLABLE_REFERENCE", isSynthetic = false)
     object ENUM_MAPPINGS_FOR_WHEN : IrDeclarationOriginImpl("ENUM_MAPPINGS_FOR_WHEN", isSynthetic = true)
     object SYNTHETIC_INLINE_CLASS_MEMBER : IrDeclarationOriginImpl("SYNTHETIC_INLINE_CLASS_MEMBER", isSynthetic = true)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/JvmSingleAbstractMethodLowering.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2010-2020 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.backend.jvm.lower
+
+import org.jetbrains.kotlin.backend.common.lower.SingleAbstractMethodLowering
+import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
+import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
+import org.jetbrains.kotlin.backend.jvm.ir.erasedUpperBound
+import org.jetbrains.kotlin.descriptors.Visibility
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.util.defaultType
+import org.jetbrains.kotlin.load.java.JavaVisibilities
+
+internal val singleAbstractMethodPhase = makeIrFilePhase(
+    ::JvmSingleAbstractMethodLowering,
+    name = "SingleAbstractMethod",
+    description = "Replace SAM conversions with instances of interface-implementing classes"
+)
+
+private class JvmSingleAbstractMethodLowering(context: JvmBackendContext) : SingleAbstractMethodLowering(context) {
+    override val privateGeneratedWrapperVisibility: Visibility
+        get() = JavaVisibilities.PACKAGE_VISIBILITY
+
+    override fun getSuperTypeForWrapper(typeOperand: IrType) = typeOperand.erasedUpperBound.defaultType
+}

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrDeclarationOrigin.kt

@@ -57,6 +57,8 @@ interface IrDeclarationOrigin {
     object ADAPTER_FOR_CALLABLE_REFERENCE : IrDeclarationOriginImpl("ADAPTER_FOR_CALLABLE_REFERENCE")
     object ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE : IrDeclarationOriginImpl("ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE")
 
+    object GENERATED_SAM_IMPLEMENTATION : IrDeclarationOriginImpl("GENERATED_SAM_IMPLEMENTATION", isSynthetic = true)
+
     val isSynthetic: Boolean get() = false
 }