JVM IR: Fixes in SAM lowering

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

@@ -10,7 +10,6 @@ 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
@@ -20,6 +19,7 @@ import org.jetbrains.kotlin.backend.jvm.ir.createJvmIrBuilder
 import org.jetbrains.kotlin.backend.jvm.ir.irArray
 import org.jetbrains.kotlin.backend.jvm.ir.isInlineParameter
 import org.jetbrains.kotlin.codegen.PropertyReferenceCodegen
+import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.builders.*
@@ -32,10 +32,7 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrClassReferenceImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrInstanceInitializerCallImpl
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
-import org.jetbrains.kotlin.ir.types.IrSimpleType
-import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.types.IrTypeProjection
-import org.jetbrains.kotlin.ir.types.typeWith
+import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
@@ -51,9 +48,7 @@ internal val callableReferencePhase = makeIrFilePhase(
 
 // Originally copied from K/Native
 internal class CallableReferenceLowering(private val context: JvmBackendContext) : FileLoweringPass, IrElementTransformerVoidWithContext() {
-    // This pass ignores function references used in inline arguments to inline functions references or in SAM conversions.
-    // We also implicitly ignore all suspend function references by only dealing with subclasses of (K)Function and not
-    // (K)SuspendFunction.
+    // This pass ignores suspend function references and function references used in inline arguments to inline functions.
     private val ignoredFunctionReferences = mutableSetOf<IrFunctionReference>()
 
     private val IrFunctionReference.isIgnored: Boolean
@@ -83,19 +78,6 @@ internal class CallableReferenceLowering(private val context: JvmBackendContext)
         return super.visitFunctionAccess(expression)
     }
 
-    // Ignore function references handled in SAM conversion
-    override fun visitTypeOperator(expression: IrTypeOperatorCall): IrExpression {
-        if (expression.operator == IrTypeOperator.SAM_CONVERSION) {
-            val invokable = expression.argument
-            if (invokable is IrFunctionReference) {
-                ignoredFunctionReferences += invokable
-            } else if (invokable is IrBlock && invokable.statements.last() is IrFunctionReference) {
-                ignoredFunctionReferences += invokable.statements.last() as IrFunctionReference
-            }
-        }
-        return super.visitTypeOperator(expression)
-    }
-
     override fun visitBlock(expression: IrBlock): IrExpression {
         if (!expression.origin.isLambda)
             return super.visitBlock(expression)
@@ -114,10 +96,31 @@ internal class CallableReferenceLowering(private val context: JvmBackendContext)
         return if (expression.isIgnored) expression else FunctionReferenceBuilder(expression).build()
     }
 
-    private inner class FunctionReferenceBuilder(val irFunctionReference: IrFunctionReference) {
-        private val isLambda = irFunctionReference.origin.isLambda
+    // Handle SAM conversions which wrap a function reference:
+    //     class sam$n(private val receiver: R) : Interface { override fun method(...) = receiver.target(...) }
+    //
+    // This avoids materializing an invokable KFunction representing, thus producing one less class.
+    // This is actually very common, as `Interface { something }` is a local function + a SAM-conversion
+    // of a reference to it into an implementation.
+    override fun visitTypeOperator(expression: IrTypeOperatorCall): IrExpression {
+        if (expression.operator == IrTypeOperator.SAM_CONVERSION) {
+            val invokable = expression.argument
+            val reference = if (invokable is IrFunctionReference) {
+                invokable
+            } else if (invokable is IrBlock && invokable.origin.isLambda && invokable.statements.last() is IrFunctionReference) {
+                invokable.statements.dropLast(1).forEach { it.transform(this, null) }
+                invokable.statements.last() as IrFunctionReference
+            } else {
+                return super.visitTypeOperator(expression)
+            }
+            reference.transformChildrenVoid()
+            return FunctionReferenceBuilder(reference, expression.typeOperand).build()
+        }
+        return super.visitTypeOperator(expression)
+    }
 
-        private val functionReferenceOrLambda = if (isLambda) context.ir.symbols.lambdaClass else context.ir.symbols.functionReference
+    private inner class FunctionReferenceBuilder(val irFunctionReference: IrFunctionReference, val samSuperType: IrType? = null) {
+        private val isLambda = irFunctionReference.origin.isLambda
 
         private val callee = irFunctionReference.symbol.owner
 
@@ -133,38 +136,46 @@ internal class CallableReferenceLowering(private val context: JvmBackendContext)
 
         private val typeArgumentsMap = irFunctionReference.typeSubstitutionMap
 
+        private val functionSuperClass =
+            samSuperType?.classOrNull ?: context.ir.symbols.getJvmFunctionClass(argumentTypes.size)
+        private val superMethod =
+            functionSuperClass.functions.single { it.owner.modality == Modality.ABSTRACT }
+        private val superType =
+            samSuperType ?: (if (isLambda) context.ir.symbols.lambdaClass else context.ir.symbols.functionReference).owner.typeWith()
+
         private val functionReferenceClass = buildClass {
             setSourceRange(irFunctionReference)
             visibility = Visibilities.LOCAL
             // A callable reference results in a synthetic class, while a lambda is not synthetic.
+            // We don't produce GENERATED_SAM_IMPLEMENTATION, which is always synthetic.
             origin = if (isLambda) JvmLoweredDeclarationOrigin.LAMBDA_IMPL else JvmLoweredDeclarationOrigin.FUNCTION_REFERENCE_IMPL
             name = Name.special("<function reference to ${callee.fqNameWhenAvailable}>")
         }.apply {
             parent = currentDeclarationParent
-            superTypes += functionReferenceOrLambda.owner.defaultType
+            superTypes += superType
+            if (samSuperType == null)
+                superTypes += functionSuperClass.typeWith(parameterTypes)
             createImplicitParameterDeclarationWithWrappedDescriptor()
             copyAttributes(irFunctionReference)
         }
 
-        fun build(): IrExpression {
+        fun build(): IrExpression = context.createIrBuilder(currentScope!!.scope.scopeOwnerSymbol).irBlock {
             val constructor = createConstructor()
-            val invokeMethod = createInvokeMethod()
+            createInvokeMethod(
+                if (samSuperType != null && boundReceiver != null) {
+                    irTemporary(boundReceiver.second)
+                } else null
+            )
 
-            val functionClass = context.ir.symbols.getJvmFunctionClass(argumentTypes.size)
-            functionReferenceClass.superTypes += functionClass.typeWith(parameterTypes)
-            invokeMethod.overriddenSymbols += functionClass.functions.single { it.owner.name.asString() == "invoke" }
-
-            if (!isLambda) {
+            if (!isLambda && samSuperType == null) {
                 createGetSignatureMethod(functionGetSignature)
                 createGetNameMethod(functionGetName)
                 createGetOwnerMethod(functionGetOwner)
             }
 
-            return context.createIrBuilder(currentScope!!.scope.scopeOwnerSymbol).irBlock(irFunctionReference) {
-                +functionReferenceClass
-                +irCall(constructor.symbol).apply {
-                    boundReceiver?.second?.let { putValueArgument(0, it) }
-                }
+            +functionReferenceClass
+            +irCall(constructor.symbol).apply {
+                if (valueArgumentsCount > 0) putValueArgument(0, boundReceiver!!.second)
             }
         }
 
@@ -176,39 +187,49 @@ internal class CallableReferenceLowering(private val context: JvmBackendContext)
                 isPrimary = true
             }.apply {
                 // Add receiver parameter for bound function references
-                boundReceiver?.first?.let { param ->
-                    valueParameters += param.copyTo(
-                        irFunction = this,
-                        index = valueParameters.size,
-                        type = param.type.substitute(typeArgumentsMap)
-                    )
+                if (samSuperType == null) {
+                    boundReceiver?.first?.let { param ->
+                        valueParameters += param.copyTo(
+                            irFunction = this,
+                            index = 0,
+                            type = param.type.substitute(typeArgumentsMap)
+                        )
+                    }
                 }
 
                 // Super constructor:
+                // - For SAM references, the super class is Any
                 // - For function references with bound receivers, accepts arity and receiver
                 // - For lambdas and function references without bound receivers, accepts arity
-                val kFunctionRefConstructor = functionReferenceOrLambda.owner.constructors.single {
-                    it.valueParameters.size == if (boundReceiver != null) 2 else 1
+                val constructor = if (samSuperType != null) {
+                    context.irBuiltIns.anyClass.owner.constructors.single()
+                } else {
+                    superType.getClass()!!.constructors.single {
+                        it.valueParameters.size == if (boundReceiver != null) 2 else 1
+                    }
                 }
 
                 body = context.createIrBuilder(symbol).irBlockBody(startOffset, endOffset) {
-                    +irDelegatingConstructorCall(kFunctionRefConstructor).apply {
-                        putValueArgument(0, irInt(argumentTypes.size))
-                        if (boundReceiver != null)
-                            putValueArgument(1, irGet(valueParameters.first()))
+                    +irDelegatingConstructorCall(constructor).apply {
+                        if (samSuperType == null) {
+                            putValueArgument(0, irInt(argumentTypes.size))
+                            if (boundReceiver != null)
+                                putValueArgument(1, irGet(valueParameters.first()))
+                        }
                     }
                     +IrInstanceInitializerCallImpl(startOffset, endOffset, functionReferenceClass.symbol, context.irBuiltIns.unitType)
                 }
             }
 
-        private fun createInvokeMethod(): IrSimpleFunction =
+        private fun createInvokeMethod(receiverVar: IrValueDeclaration?): IrSimpleFunction =
             functionReferenceClass.addFunction {
-                name = Name.identifier("invoke")
+                name = superMethod.owner.name
                 returnType = callee.returnType
                 isSuspend = callee.isSuspend
             }.apply {
+                overriddenSymbols += superMethod
                 dispatchReceiverParameter = parentAsClass.thisReceiver!!.copyTo(this)
-                if (isLambda) createLambdaInvokeMethod() else createFunctionReferenceInvokeMethod()
+                if (isLambda) createLambdaInvokeMethod() else createFunctionReferenceInvokeMethod(receiverVar)
             }
 
         // Inline the body of an anonymous function into the generated lambda subclass.
@@ -248,7 +269,7 @@ internal class CallableReferenceLowering(private val context: JvmBackendContext)
             }
         }
 
-        private fun IrSimpleFunction.createFunctionReferenceInvokeMethod() {
+        private fun IrSimpleFunction.createFunctionReferenceInvokeMethod(receiver: IrValueDeclaration?) {
             for ((index, argumentType) in argumentTypes.withIndex()) {
                 addValueParameter {
                     name = Name.identifier("p$index")
@@ -266,22 +287,31 @@ internal class CallableReferenceLowering(private val context: JvmBackendContext)
                     for (parameter in callee.explicitParameters) {
                         when {
                             boundReceiver?.first == parameter ->
-                                // Bound receiver parameter
-                                irImplicitCast(
-                                    irGetField(irGet(dispatchReceiverParameter!!), functionReferenceReceiverField),
-                                    boundReceiver.second.type
-                                )
+                                // Bound receiver parameter. For function references, this is stored in a field of the superclass.
+                                // For sam references, we just capture the value in a local variable and LocalDeclarationsLowering
+                                // will put it into a field.
+                                if (samSuperType == null)
+                                    irImplicitCast(
+                                        irGetField(irGet(dispatchReceiverParameter!!), functionReferenceReceiverField),
+                                        boundReceiver.second.type
+                                    )
+                                else
+                                    irGet(receiver!!)
 
                             // If a vararg parameter corresponds to exactly one KFunction argument, which is an array, that array
-                            // is forwarded as is. In all other cases, excess arguments are packed into a new array.
+                            // is forwarded as is.
                             //
                             //     fun f(x: (Int, Array<String>) -> String) = x(0, arrayOf("OK", "FAIL"))
-                            //     fun g(x: (Int, String, String) -> String) = x(0, "OK", "FAIL")
                             //     fun h(i: Int, vararg xs: String) = xs[i]
-                            //     f(::h) == g(::h)
+                            //     f(::h)
                             //
                             parameter.isVararg && unboundIndex < argumentTypes.size && parameter.type == valueParameters[unboundIndex].type ->
-                                irArray(parameter.type) { addSpread(irGet(valueParameters[unboundIndex++])) }
+                                irGet(valueParameters[unboundIndex++])
+                            // In all other cases, excess arguments are packed into a new array.
+                            //
+                            //     fun g(x: (Int, String, String) -> String) = x(0, "OK", "FAIL")
+                            //     f(::h) == g(::h)
+                            //
                             parameter.isVararg && (unboundIndex < argumentTypes.size || !parameter.hasDefaultValue()) ->
                                 irArray(parameter.type) {
                                     (unboundIndex until argumentTypes.size).forEach { +irGet(valueParameters[unboundIndex++]) }
@@ -341,11 +371,7 @@ internal class CallableReferenceLowering(private val context: JvmBackendContext)
     companion object {
         private fun IrBuilderWithScope.kClassReference(classType: IrType) =
             IrClassReferenceImpl(
-                startOffset,
-                endOffset,
-                context.irBuiltIns.kClassClass.typeWith(),
-                context.irBuiltIns.kClassClass,
-                classType
+                startOffset, endOffset, context.irBuiltIns.kClassClass.typeWith(), context.irBuiltIns.kClassClass, classType
             )
 
         private fun IrBuilderWithScope.kClassToJavaClass(kClassReference: IrExpression, context: JvmBackendContext) =

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

@@ -20,8 +20,12 @@ import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.ir.builders.*
 import org.jetbrains.kotlin.ir.builders.declarations.*
-import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.declarations.IrAttributeContainer
+import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.copyAttributes
+import org.jetbrains.kotlin.ir.expressions.IrExpression
+import org.jetbrains.kotlin.ir.expressions.IrTypeOperator
+import org.jetbrains.kotlin.ir.expressions.IrTypeOperatorCall
 import org.jetbrains.kotlin.ir.expressions.impl.IrInstanceInitializerCallImpl
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.classifierOrFail
@@ -44,7 +48,6 @@ internal val singleAbstractMethodPhase = makeIrFilePhase(
 class SingleAbstractMethodLowering(val context: CommonBackendContext) : ClassLoweringPass {
     override fun lower(irClass: IrClass) {
         val cachedImplementations = mutableMapOf<Pair<IrType, IrType>, IrClass>()
-        val localImplementations = mutableListOf<IrClass>()
         irClass.transformChildrenVoid(object : IrElementTransformerVoidWithContext() {
             override fun visitTypeOperator(expression: IrTypeOperatorCall): IrExpression {
                 if (expression.operator != IrTypeOperator.SAM_CONVERSION)
@@ -53,32 +56,32 @@ class SingleAbstractMethodLowering(val context: CommonBackendContext) : ClassLow
                 val invokable = expression.argument.transform(this, null)
                 // Running in the class context, so empty scope means this is a field/anonymous initializer.
                 val scopeOwnerSymbol = currentScope?.scope?.scopeOwnerSymbol ?: irClass.symbol
-                return context.createIrBuilder(scopeOwnerSymbol).irBlock(invokable, null, superType) {
-                    // Not an exhaustive check, but enough to cover the most common cases.
-                    if (invokable is IrFunctionReference) {
-                        // Runnable(::function)
-                        +createFunctionProxyInstance(superType, invokable)
-                    } else if (invokable is IrBlock && invokable.statements.last() is IrFunctionReference) {
-                        // Runnable { lambda }
-                        for (statement in invokable.statements.dropLast(1))
-                            +statement
-                        +createFunctionProxyInstance(superType, invokable.statements.last() as IrFunctionReference)
+                context.createIrBuilder(scopeOwnerSymbol).apply {
+                    // Do not generate a wrapper class for null, it has no invoke() anyway.
+                    if (invokable.isNullConst())
+                        return invokable
+
+                    val implementation = cachedImplementations.getOrPut(superType to invokable.type) {
+                        createObjectProxy(superType, invokable.type, expression)
+                    }
+
+                    return if (superType.isNullable() && invokable.type.isNullable()) {
+                        irBlock(invokable, null, superType) {
+                            val invokableVariable = irTemporary(invokable)
+                            val instance = irCall(implementation.constructors.single()).apply {
+                                putValueArgument(0, irGet(invokableVariable))
+                            }
+                            irIfNull(superType, irGet(invokableVariable), irNull(), instance)
+                        }
                     } else {
-                        // Fall back to materializing an invokable object.
-                        +createObjectProxyInstance(superType, invokable, expression)
+                        irCall(implementation.constructors.single()).apply { putValueArgument(0, invokable) }
                     }
                 }
             }
 
-            // Construct a class that implements the specified SAM interface and contains a bunch of fields
-            // in which the arguments to the constructor are stored:
-            //     class sam$n(private val arg0: T0, ...) { override fun method(...) = <whatever buildOverride returns> }
-            private fun implement(
-                superType: IrType,
-                parameters: List<IrType>,
-                attributeOwner: IrAttributeContainer,
-                buildOverride: IrSimpleFunction.(List<IrField>) -> IrBody
-            ): IrClass {
+            // Construct a class that wraps an invokable object into an implementation of an interface:
+            //     class sam$n(private val invokable: F) : Interface { override fun method(...) = invokable(...) }
+            private fun createObjectProxy(superType: IrType, invokableType: IrType, attributeOwner: IrAttributeContainer): IrClass {
                 val superClass = superType.classifierOrFail.owner as IrClass
                 // The language documentation prohibits casting lambdas to classes, but if it was allowed,
                 // the `irDelegatingConstructorCall` in the constructor below would need to be modified.
@@ -94,30 +97,26 @@ class SingleAbstractMethodLowering(val context: CommonBackendContext) : ClassLow
                     superTypes += superType
                 }.copyAttributes(attributeOwner)
 
-                val fields = parameters.mapIndexed { i, fieldType ->
-                    subclass.addField {
-                        name = Name.identifier("arg$i")
-                        type = fieldType
-                        origin = subclass.origin
-                        visibility = Visibilities.PRIVATE
-                    }
+                val field = subclass.addField {
+                    name = Name.identifier("arg0")
+                    type = invokableType
+                    origin = subclass.origin
+                    visibility = Visibilities.PRIVATE
                 }
 
                 subclass.addConstructor {
                     origin = subclass.origin
                     isPrimary = true
                 }.apply {
-                    for (field in fields) {
-                        addValueParameter {
-                            name = field.name
-                            type = field.type
-                            origin = subclass.origin
-                        }
+                    val parameter = addValueParameter {
+                        name = field.name
+                        type = field.type
+                        origin = subclass.origin
                     }
+
                     body = context.createIrBuilder(symbol).irBlockBody(startOffset, endOffset) {
                         +irDelegatingConstructorCall(context.irBuiltIns.anyClass.owner.constructors.single())
-                        for ((field, parameter) in fields.zip(valueParameters))
-                            +irSetField(irGet(subclass.thisReceiver!!), field, irGet(parameter))
+                        +irSetField(irGet(subclass.thisReceiver!!), field, irGet(parameter))
                         +IrInstanceInitializerCallImpl(startOffset, endOffset, subclass.symbol, context.irBuiltIns.unitType)
                     }
                 }
@@ -129,102 +128,21 @@ class SingleAbstractMethodLowering(val context: CommonBackendContext) : ClassLow
                     visibility = superMethod.visibility
                     origin = subclass.origin
                 }.apply {
-                    overriddenSymbols.add(superMethod.symbol)
+                    overriddenSymbols += superMethod.symbol
                     dispatchReceiverParameter = subclass.thisReceiver!!.copyTo(this)
                     superMethod.valueParameters.mapTo(valueParameters) { it.copyTo(this) }
-                    body = buildOverride(fields)
-                }
-
-                return subclass
-            }
-
-            // 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, invokableType: IrType, attributeOwner: IrAttributeContainer): IrClass =
-                implement(superType, listOf(invokableType), attributeOwner) { fields ->
-                    context.createIrBuilder(symbol).irBlockBody(startOffset, endOffset) {
-                        val invokableClass = invokableType.classifierOrFail.owner as IrClass
-                        +irReturn(irCall(invokableClass.functions.single { it.name == OperatorNameConventions.INVOKE }).apply {
-                            dispatchReceiver = irGetField(irGet(dispatchReceiverParameter!!), fields[0])
+                    val invokableClass = invokableType.classifierOrFail.owner as IrClass
+                    body = context.createIrBuilder(symbol).run {
+                        irExprBody(irCall(invokableClass.functions.single { it.name == OperatorNameConventions.INVOKE }).apply {
+                            dispatchReceiver = irGetField(irGet(dispatchReceiverParameter!!), field)
                             valueParameters.forEachIndexed { i, parameter -> putValueArgument(i, irGet(parameter)) }
                         })
                     }
                 }
 
-            private fun IrBlockBuilder.createObjectProxyInstance(
-                superType: IrType, invokable: IrExpression, attributeOwner: IrAttributeContainer
-            ): IrExpression {
-                // Do not generate a wrapper class for null, it has no invoke() anyway.
-                if (invokable.isNullConst())
-                    return invokable
-                val implementation = cachedImplementations.getOrPut(superType to invokable.type) {
-                    createObjectProxy(superType, invokable.type, attributeOwner)
-                }
-                return if (superType.isNullable() && invokable.type.isNullable()) {
-                    val invokableVariable = irTemporary(invokable)
-                    val instance = irCall(implementation.constructors.single()).apply { putValueArgument(0, irGet(invokableVariable)) }
-                    irIfNull(superType, irGet(invokableVariable), irNull(), instance)
-                } else {
-                    irCall(implementation.constructors.single()).apply { putValueArgument(0, invokable) }
-                }
-            }
-
-            // This lowering is located after LocalDeclarationsLowering. On the one hand, this allows us to cache
-            // object-wrapping classes without checking if the types are local declarations or not. On the other hand,
-            // this means we need to manually create fields for all bound arguments when wrapping callable references.
-            private val IrFunctionReference.arguments: List<IrExpression?>
-                get() = listOf(dispatchReceiver).filter { symbol.owner.dispatchReceiverParameter != null } +
-                        listOf(extensionReceiver).filter { symbol.owner.extensionReceiverParameter != null } +
-                        (0 until valueArgumentsCount).map(::getValueArgument)
-
-            // Construct a class that forwards method calls to an existing function/method:
-            //     class sam$n(private val receiver: R) : Interface { override fun method(...) = receiver.target(...) }
-            //
-            // Unlike the above variant, this avoids materializing an invokable KFunction representing
-            // the target in CallableReferenceLowering, thus producing one less class. This is actually very
-            // common, as `Interface { something }` is a local function + a SAM-conversion of a reference
-            // to it into an implementation.
-            private fun createFunctionProxy(superType: IrType, reference: IrFunctionReference): IrClass =
-                implement(superType, reference.arguments.mapNotNull { it?.type }, reference) { fields ->
-                    context.createIrBuilder(symbol).irBlockBody(startOffset, endOffset) {
-                        +irReturn(irCall(reference.symbol).apply {
-                            var boundOffset = 0
-                            var offset = 0
-                            val arguments = reference.arguments.map {
-                                if (it != null)
-                                    irGetField(irGet(dispatchReceiverParameter!!), fields[boundOffset++])
-                                else
-                                    irGet(valueParameters[offset++])
-                            }.toMutableList()
-                            if (reference.symbol.owner.dispatchReceiverParameter != null) {
-                                dispatchReceiver = arguments.removeAt(0)
-                            }
-                            if (reference.symbol.owner.extensionReceiverParameter != null) {
-                                extensionReceiver = arguments.removeAt(0)
-                            }
-                            arguments.forEachIndexed(::putValueArgument)
-                        })
-                    }
-                }
-
-            private fun IrBlockBuilder.createFunctionProxyInstance(superType: IrType, reference: IrFunctionReference): IrExpression {
-                val implementation = createFunctionProxy(superType, reference)
-                if (reference.origin == IrStatementOrigin.ANONYMOUS_FUNCTION || reference.origin == IrStatementOrigin.LAMBDA) {
-                    val target = reference.symbol.owner
-                    implementation.functions.single().apply {
-                        annotations.addAll(target.annotations)
-                        valueParameters.forEachIndexed { i, p ->
-                            p.annotations.addAll(target.valueParameters[i].annotations)
-                        }
-                    }
-                }
-                localImplementations += implementation
-                return irCall(implementation.constructors.single()).apply {
-                    reference.arguments.filterNotNull().forEachIndexed(::putValueArgument)
-                }
+                return subclass
             }
         })
         irClass.declarations += cachedImplementations.values
-        irClass.declarations += localImplementations
     }
 }

compiler/testData/codegen/box/reflection/enclosing/kt6691_lambdaInSamConstructor.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 // TARGET_BACKEND: JVM
 
 // WITH_REFLECT