KT-36024 Generate adapted callable references as lambdas

Make sure both JVM and JVM_IR use the same information to determine
whether a callable reference requires argument adaptation.

compiler/backend/src/org/jetbrains/kotlin/codegen/ClosureCodegen.java

@@ -74,7 +74,9 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
     protected final Type asmType;
     protected final int visibilityFlag;
     private final boolean shouldHaveBoundReferenceReceiver;
+    private final boolean isRegularFunctionReference;
     private final boolean isOptimizedFunctionReference;
+    private final boolean isAdaptedFunctionReference;
 
     private Method constructor;
     protected Type superClassAsmType;
@@ -125,9 +127,17 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
         assert closure != null : "Closure must be calculated for class: " + classDescriptor;
 
         this.shouldHaveBoundReferenceReceiver = CallableReferenceUtilKt.isForBoundCallableReference(closure);
+
+        ClassifierDescriptor superClassDescriptor = superClassType.getConstructor().getDeclarationDescriptor();
+        this.isRegularFunctionReference =
+                functionReferenceTarget != null &&
+                superClassDescriptor == state.getJvmRuntimeTypes().getFunctionReference();
         this.isOptimizedFunctionReference =
                 functionReferenceTarget != null &&
-                superClassType.getConstructor().getDeclarationDescriptor() == state.getJvmRuntimeTypes().getFunctionReferenceImpl();
+                superClassDescriptor == state.getJvmRuntimeTypes().getFunctionReferenceImpl();
+        this.isAdaptedFunctionReference =
+                functionReferenceTarget != null &&
+                superClassDescriptor == state.getJvmRuntimeTypes().getLambda();
 
         this.asmType = typeMapper.mapClass(classDescriptor);
 
@@ -189,15 +199,29 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
     protected void generateClosureBody() {
         functionCodegen.generateMethod(JvmDeclarationOriginKt.OtherOrigin(element, funDescriptor), funDescriptor, strategy);
 
-        if (functionReferenceTarget != null && !isOptimizedFunctionReference) {
+        if (isRegularFunctionReference) {
             generateFunctionReferenceMethods(functionReferenceTarget);
         }
 
+        if (shouldHaveBoundReferenceReceiver && isAdaptedFunctionReference) {
+            generateBoundAdaptedCallableReferenceReceiverField();
+        }
+
         functionCodegen.generateDefaultIfNeeded(
                 context.intoFunction(funDescriptor), funDescriptor, context.getContextKind(), DefaultParameterValueLoader.DEFAULT, null
         );
     }
 
+    private void generateBoundAdaptedCallableReferenceReceiverField() {
+        v.newField(
+                JvmDeclarationOriginKt.OtherOrigin(element, funDescriptor),
+                ACC_PRIVATE,
+                BOUND_REFERENCE_RECEIVER,
+                OBJECT_TYPE.getDescriptor(),
+                null, null
+        );
+    }
+
     protected void generateBridges() {
         FunctionDescriptor erasedInterfaceFunction;
         if (samType == null) {
@@ -500,11 +524,12 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
             List<Type> superCtorArgTypes = new ArrayList<>();
             if (superClassAsmType.equals(LAMBDA) || superClassAsmType.equals(FUNCTION_REFERENCE) ||
                 superClassAsmType.equals(FUNCTION_REFERENCE_IMPL) ||
-                CoroutineCodegenUtilKt.isCoroutineSuperClass(state.getLanguageVersionSettings(), superClassAsmType.getInternalName())) {
+                CoroutineCodegenUtilKt.isCoroutineSuperClass(state.getLanguageVersionSettings(), superClassAsmType.getInternalName())
+            ) {
                 int arity = calculateArity();
                 iv.iconst(arity);
                 superCtorArgTypes.add(Type.INT_TYPE);
-                if (shouldHaveBoundReferenceReceiver) {
+                if (shouldHaveBoundReferenceReceiver && !isAdaptedFunctionReference) {
                     CallableReferenceUtilKt.loadBoundReferenceReceiverParameter(
                             iv, boundReceiverParameterIndex, boundReceiverType, boundReceiverKotlinType
                     );
@@ -533,6 +558,19 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
                     Type.getMethodDescriptor(Type.VOID_TYPE, superCtorArgTypes.toArray(new Type[0])), false
             );
 
+            // Bound adapted function references store receiver in a separate field.
+            if (shouldHaveBoundReferenceReceiver && isAdaptedFunctionReference) {
+                iv.load(0, superClassAsmType);
+                CallableReferenceUtilKt.loadBoundReferenceReceiverParameter(
+                        iv, boundReceiverParameterIndex, boundReceiverType, boundReceiverKotlinType
+                );
+                iv.putfield(
+                        asmType.getInternalName(),
+                        BOUND_REFERENCE_RECEIVER,
+                        OBJECT_TYPE.getDescriptor()
+                );
+            }
+
             iv.visitInsn(RETURN);
 
             FunctionCodegen.endVisit(iv, "constructor", element);

compiler/backend/src/org/jetbrains/kotlin/codegen/JvmRuntimeTypes.kt

@@ -43,9 +43,8 @@ class JvmRuntimeTypes(
     private fun propertyClasses(prefix: String, suffix: String): Lazy<List<ClassDescriptor>> =
         lazy { (0..2).map { i -> createClass(kotlinJvmInternalPackage, prefix + i + suffix) } }
 
-    private val lambda: ClassDescriptor by internal("Lambda")
-
-    private val functionReference: ClassDescriptor by internal("FunctionReference")
+    val lambda: ClassDescriptor by internal("Lambda")
+    val functionReference: ClassDescriptor by internal("FunctionReference")
     val functionReferenceImpl: ClassDescriptor by internal("FunctionReferenceImpl")
 
     private val localVariableReference: ClassDescriptor by internal("LocalVariableReference")
@@ -135,7 +134,8 @@ class JvmRuntimeTypes(
     fun getSupertypesForFunctionReference(
         referencedFunction: FunctionDescriptor,
         anonymousFunctionDescriptor: AnonymousFunctionDescriptor,
-        isBound: Boolean
+        isBound: Boolean,
+        isAdaptedCallableReference: Boolean
     ): Collection<KotlinType> {
         val receivers = computeExpectedNumberOfReceivers(referencedFunction, isBound)
 
@@ -151,7 +151,11 @@ class JvmRuntimeTypes(
         )
 
         val suspendFunctionType = if (referencedFunction.isSuspend) suspendFunctionInterface?.defaultType else null
-        val superClass = if (generateOptimizedCallableReferenceSuperClasses) functionReferenceImpl else functionReference
+        val superClass = when {
+            isAdaptedCallableReference -> lambda
+            generateOptimizedCallableReferenceSuperClasses -> functionReferenceImpl
+            else -> functionReference
+        }
         return listOfNotNull(superClass.defaultType, functionType, suspendFunctionType)
     }
 
@@ -172,4 +176,4 @@ class JvmRuntimeTypes(
 
         return classes[arity].defaultType
     }
-}
+}

compiler/backend/src/org/jetbrains/kotlin/codegen/binding/CodegenAnnotatingVisitor.java

@@ -16,6 +16,7 @@ import kotlin.collections.CollectionsKt;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.builtins.FunctionTypesKt;
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
 import org.jetbrains.kotlin.builtins.ReflectionTypes;
 import org.jetbrains.kotlin.cfg.WhenChecker;
 import org.jetbrains.kotlin.codegen.*;
@@ -357,6 +358,28 @@ class CodegenAnnotatingVisitor extends KtVisitorVoid {
         classStack.pop();
     }
 
+    private boolean isAdaptedCallableReference(
+            @NotNull KtCallableReferenceExpression expression,
+            @NotNull ResolvedCall<?> resolvedCall
+    ) {
+        CallableDescriptor resultingDescriptor = resolvedCall.getResultingDescriptor();
+        if (!(resultingDescriptor instanceof FunctionDescriptor)) return false;
+        FunctionDescriptor functionDescriptor = (FunctionDescriptor) resultingDescriptor;
+
+        // Callable reference is adapted if:
+        // - adapter arguments mapping is present in value arguments of corresponding resolved call;
+        // - return type is not Unit, and expected return type is Unit.
+
+        if (!resolvedCall.getValueArguments().isEmpty()) return true;
+
+        KotlinType callableReferenceType = bindingContext.getType(expression);
+        assert callableReferenceType != null : "No type for callable reference: " + expression.getText();
+        KotlinType callableReferenceReturnType = CollectionsKt.last(callableReferenceType.getArguments()).getType();
+        KotlinType functionReturnType = functionDescriptor.getReturnType();
+        assert functionReturnType != null : "No return type for function: " + functionDescriptor;
+        return KotlinBuiltIns.isUnit(callableReferenceReturnType) && !KotlinBuiltIns.isUnit(functionReturnType);
+    }
+
     @Override
     public void visitCallableReferenceExpression(@NotNull KtCallableReferenceExpression expression) {
         ResolvedCall<?> referencedFunction = CallUtilKt.getResolvedCall(expression.getCallableReference(), bindingContext);
@@ -380,7 +403,8 @@ class CodegenAnnotatingVisitor extends KtVisitorVoid {
             if (callableDescriptor == null) return;
 
             supertypes = runtimeTypes.getSupertypesForFunctionReference(
-                    (FunctionDescriptor) target, (AnonymousFunctionDescriptor) callableDescriptor, receiverType != null
+                    (FunctionDescriptor) target, (AnonymousFunctionDescriptor) callableDescriptor, receiverType != null,
+                    isAdaptedCallableReference(expression, referencedFunction)
             );
         }
         else if (target instanceof PropertyDescriptor) {

compiler/fir/fir2ir/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -1983,6 +1983,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/callableReference/nested.kt");
         }
 
+        @TestMetadata("noReflectionForAdaptedCallableReferences.kt")
+        public void testNoReflectionForAdaptedCallableReferences() throws Exception {
+            runTest("compiler/testData/codegen/box/callableReference/noReflectionForAdaptedCallableReferences.kt");
+        }
+
         @TestMetadata("optimizedSuperclasses_after.kt")
         public void testOptimizedSuperclasses_after() throws Exception {
             runTest("compiler/testData/codegen/box/callableReference/optimizedSuperclasses_after.kt");

compiler/fir/fir2ir/tests/org/jetbrains/kotlin/fir/Fir2IrTextTestGenerated.java

@@ -1395,6 +1395,11 @@ public class Fir2IrTextTestGenerated extends AbstractFir2IrTextTest {
                 runTest("compiler/testData/ir/irText/expressions/callableReferences/adaptedExtensionFunctions.kt");
             }
 
+            @TestMetadata("adaptedWithCoercionToUnit.kt")
+            public void testAdaptedWithCoercionToUnit() throws Exception {
+                runTest("compiler/testData/ir/irText/expressions/callableReferences/adaptedWithCoercionToUnit.kt");
+            }
+
             public void testAllFilesPresentInCallableReferences() throws Exception {
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/ir/irText/expressions/callableReferences"), Pattern.compile("^(.+)\\.kt$"), null, true);
             }

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tower/ResolvedAtomCompleter.kt

@@ -7,10 +7,7 @@ package org.jetbrains.kotlin.resolve.calls.tower
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.createFunctionType
-import org.jetbrains.kotlin.descriptors.CallableDescriptor
-import org.jetbrains.kotlin.descriptors.FunctionDescriptor
-import org.jetbrains.kotlin.descriptors.ModuleDescriptor
-import org.jetbrains.kotlin.descriptors.PropertyDescriptor
+import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.impl.FunctionDescriptorImpl
 import org.jetbrains.kotlin.descriptors.impl.ReceiverParameterDescriptorImpl
 import org.jetbrains.kotlin.psi.KtElement
@@ -41,6 +38,7 @@ import org.jetbrains.kotlin.resolve.deprecation.DeprecationResolver
 import org.jetbrains.kotlin.resolve.scopes.receivers.TransientReceiver
 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue
 import org.jetbrains.kotlin.types.*
+import org.jetbrains.kotlin.types.expressions.CoercionStrategy
 import org.jetbrains.kotlin.types.expressions.DoubleColonExpressionResolver
 import org.jetbrains.kotlin.types.expressions.ExpressionTypingServices
 import org.jetbrains.kotlin.types.expressions.typeInfoFactory.createTypeInfo
@@ -396,7 +394,6 @@ class ResolvedAtomCompleter(
         callableReferenceAdaptation: CallableReferenceAdaptation?
     ) {
         if (callableReferenceAdaptation == null) return
-
         val callElement = resolvedCall.call.callElement
         val isUnboundReference = resolvedCall.dispatchReceiver is TransientReceiver
 
@@ -409,34 +406,55 @@ class ResolvedAtomCompleter(
             )
         }
 
+        // We should record argument mapping only if callable reference requires adaptation:
+        // - argument mapping is non-trivial: any of the arguments were mapped as defaults or vararg elements;
+        // - result should be coerced.
+        var hasNonTrivialMapping = false
+        val mappedArguments = ArrayList<Pair<ValueParameterDescriptor, ResolvedValueArgument>>()
         for ((valueParameter, resolvedCallArgument) in callableReferenceAdaptation.mappedArguments) {
-            resolvedCall.recordValueArgument(
-                valueParameter,
-                when (resolvedCallArgument) {
-                    ResolvedCallArgument.DefaultArgument ->
-                        DefaultValueArgument.DEFAULT
-                    is ResolvedCallArgument.SimpleArgument -> {
-                        val valueArgument = makeFakeValueArgument(resolvedCallArgument.callArgument)
-                        if (valueParameter.isVararg)
-                            VarargValueArgument(
-                                listOf(
-                                    FakeImplicitSpreadValueArgumentForCallableReferenceImpl(callElement, valueArgument)
-                                )
-                            )
-                        else
-                            ExpressionValueArgument(valueArgument)
-                    }
-                    is ResolvedCallArgument.VarargArgument ->
-                        VarargValueArgument(
-                            resolvedCallArgument.arguments.map {
-                                makeFakeValueArgument(it)
-                            }
-                        )
+            val resolvedValueArgument = when (resolvedCallArgument) {
+                ResolvedCallArgument.DefaultArgument -> {
+                    hasNonTrivialMapping = true
+                    DefaultValueArgument.DEFAULT
                 }
-            )
+                is ResolvedCallArgument.SimpleArgument -> {
+                    val valueArgument = makeFakeValueArgument(resolvedCallArgument.callArgument)
+                    if (valueParameter.isVararg)
+                        VarargValueArgument(
+                            listOf(
+                                FakeImplicitSpreadValueArgumentForCallableReferenceImpl(callElement, valueArgument)
+                            )
+                        )
+                    else
+                        ExpressionValueArgument(valueArgument)
+                }
+                is ResolvedCallArgument.VarargArgument -> {
+                    hasNonTrivialMapping = true
+                    VarargValueArgument(
+                        resolvedCallArgument.arguments.map {
+                            makeFakeValueArgument(it)
+                        }
+                    )
+                }
+            }
+            mappedArguments.add(valueParameter to resolvedValueArgument)
+        }
+        if (hasNonTrivialMapping || isCallableReferenceWithCoercion(resolvedCall, callableReferenceAdaptation.coercionStrategy)) {
+            for ((valueParameter, resolvedValueArgument) in mappedArguments) {
+                resolvedCall.recordValueArgument(valueParameter, resolvedValueArgument)
+            }
         }
     }
 
+    private fun isCallableReferenceWithCoercion(
+        resolvedCall: ResolvedCall<CallableDescriptor>,
+        coercionStrategy: CoercionStrategy
+    ): Boolean =
+        when (coercionStrategy) {
+            CoercionStrategy.NO_COERCION -> false
+            CoercionStrategy.COERCION_TO_UNIT -> !resolvedCall.resultingDescriptor.returnType!!.isUnit()
+        }
+
     private fun completeCollectionLiteralCalls(collectionLiteralArgument: ResolvedCollectionLiteralAtom) {
         val psiCallArgument = collectionLiteralArgument.atom.psiCallArgument as CollectionLiteralKotlinCallArgumentImpl
         val context = psiCallArgument.outerCallContext

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ReflectionReferencesGenerator.kt

@@ -41,7 +41,7 @@ import org.jetbrains.kotlin.resolve.calls.model.*
 import org.jetbrains.kotlin.resolve.scopes.receivers.TransientReceiver
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.expressions.DoubleColonLHS
-import org.jetbrains.kotlin.utils.addIfNotNull
+import org.jetbrains.kotlin.utils.SmartList
 
 class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : StatementGeneratorExtension(statementGenerator) {
 
@@ -72,13 +72,10 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
 
         val callBuilder = unwrapCallableDescriptorAndTypeArguments(resolvedCall, context.extensions.samConversion)
 
-        if (resolvedCall.valueArguments.isNotEmpty()) {
-            val adaptedCallableReference = generateAdaptedCallableReference(ktCallableReference, callBuilder)
-            if (adaptedCallableReference.hasResultAdaptation ||
-                !isTrivialArgumentAdaptation(adaptedCallableReference.irAdapteeCall)
-            ) {
-                return adaptedCallableReference.irReferenceExpression
-            }
+        if (resolvedCall.valueArguments.isNotEmpty() ||
+            requiresCoercionToUnit(resolvedDescriptor, getTypeInferredByFrontendOrFail(ktCallableReference))
+        ) {
+            return generateAdaptedCallableReference(ktCallableReference, callBuilder)
         }
 
         return statementGenerator.generateCallReceiver(
@@ -99,27 +96,15 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
         }
     }
 
-    private fun isTrivialArgumentAdaptation(irAdapteeCall: IrFunctionAccessExpression): Boolean {
-        for (i in 0 until irAdapteeCall.valueArgumentsCount) {
-            val irValueArgument = irAdapteeCall.getValueArgument(i) ?: return false
-            if (irValueArgument is IrVararg) {
-                val irVarargElements = irValueArgument.elements
-                if (irVarargElements.size != 1 || irVarargElements[0] !is IrSpreadElement) return false
-            }
-        }
-        return true
+    private fun requiresCoercionToUnit(descriptor: CallableDescriptor, callableReferenceType: KotlinType): Boolean {
+        val ktExpectedReturnType = callableReferenceType.arguments.last().type
+        return KotlinBuiltIns.isUnit(ktExpectedReturnType) && !KotlinBuiltIns.isUnit(descriptor.returnType!!)
     }
 
-    private class AdaptedCallableReference(
-        val irReferenceExpression: IrExpression,
-        val irAdapteeCall: IrFunctionAccessExpression,
-        val hasResultAdaptation: Boolean
-    )
-
     private fun generateAdaptedCallableReference(
         ktCallableReference: KtCallableReferenceExpression,
         callBuilder: CallBuilder
-    ): AdaptedCallableReference {
+    ): IrExpressionBase {
         val adapteeDescriptor = callBuilder.descriptor
         if (adapteeDescriptor !is FunctionDescriptor) {
             throw AssertionError("Function descriptor expected in adapted callable reference: $adapteeDescriptor")
@@ -140,10 +125,6 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
         val irAdapterFun = createAdapterFun(startOffset, endOffset, adapteeDescriptor, ktExpectedParameterTypes, ktExpectedReturnType)
         val adapteeCall = createAdapteeCall(startOffset, endOffset, ktCallableReference, adapteeSymbol, callBuilder, irAdapterFun)
         val irCall = adapteeCall.callExpression
-        val irAdapteeCallInner = adapteeCall.innerCallExpression
-
-        val tmpDispatchReceiver = adapteeCall.tmpDispatchReceiver
-        val tmpExtensionReceiver = adapteeCall.tmpExtensionReceiver
 
         irAdapterFun.body = IrBlockBodyImpl(startOffset, endOffset).apply {
             if (KotlinBuiltIns.isUnit(ktExpectedReturnType))
@@ -152,33 +133,27 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
                 statements.add(IrReturnImpl(startOffset, endOffset, context.irBuiltIns.nothingType, irAdapterFun.symbol, irCall))
         }
 
-        val irBlock = IrBlockImpl(startOffset, endOffset, irFunctionalType).apply {
-            statements.addIfNotNull(tmpDispatchReceiver)
-            statements.addIfNotNull(tmpExtensionReceiver)
-            statements.add(irAdapterFun)
-            statements.add(
-                IrFunctionReferenceImpl(
-                    startOffset, endOffset,
-                    irFunctionalType,
-                    irAdapterFun.symbol,
-                    typeArgumentsCount = 0,
-                    valueArgumentsCount = irAdapterFun.valueParameters.size,
-                    reflectionTarget = null
-                )
+        val irFunExpr = IrFunctionExpressionImpl(
+            startOffset, endOffset,
+            irFunctionalType,
+            irAdapterFun,
+            IrStatementOrigin.LAMBDA
+        )
+
+        return if (adapteeCall.tmpReceivers.isEmpty()) {
+            irFunExpr
+        } else {
+            IrBlockImpl(
+                startOffset, endOffset, irFunctionalType,
+                origin = null,
+                statements = adapteeCall.tmpReceivers + irFunExpr
             )
         }
-
-        return AdaptedCallableReference(
-            irBlock, irAdapteeCallInner,
-            KotlinBuiltIns.isUnit(ktExpectedReturnType) && !KotlinBuiltIns.isUnit(adapteeDescriptor.returnType!!)
-        )
     }
 
     private class AdapteeCall(
         val callExpression: IrExpression,
-        val innerCallExpression: IrFunctionAccessExpression,
-        val tmpDispatchReceiver: IrVariable?,
-        val tmpExtensionReceiver: IrVariable?
+        val tmpReceivers: List<IrVariable>
     )
 
     private fun createAdapteeCall(
@@ -192,9 +167,7 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
         val resolvedCall = callBuilder.original
         val resolvedDescriptor = resolvedCall.resultingDescriptor
 
-        var irAdapteeCall: IrFunctionAccessExpression? = null
-        var tmpDispatchReceiver: IrVariable? = null
-        var tmpExtensionReceiver: IrVariable? = null
+        val tmpReceivers = SmartList<IrVariable>()
 
         val irCall = statementGenerator.generateCallReceiver(
             ktCallableReference,
@@ -228,7 +201,7 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
                 } else {
                     val irVariable = statementGenerator.scope.createTemporaryVariable(irDispatchReceiver, "this")
                     irAdapteeCallInner.dispatchReceiver = IrGetValueImpl(startOffset, endOffset, irVariable.symbol)
-                    tmpDispatchReceiver = irVariable
+                    tmpReceivers.add(irVariable)
                 }
             }
 
@@ -238,7 +211,7 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
                 } else {
                     val irVariable = statementGenerator.scope.createTemporaryVariable(irExtensionReceiver, "receiver")
                     irAdapteeCallInner.extensionReceiver = IrGetValueImpl(startOffset, endOffset, irVariable.symbol)
-                    tmpExtensionReceiver = irVariable
+                    tmpReceivers.add(irVariable)
                 }
             }
 
@@ -246,12 +219,10 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
 
             putAdaptedValueArguments(startOffset, endOffset, irAdapteeCallInner, irAdapterFun, resolvedCall)
 
-            irAdapteeCall = irAdapteeCallInner
-
             irAdapteeCallInner
         }
 
-        return AdapteeCall(irCall, irAdapteeCall!!, tmpDispatchReceiver, tmpExtensionReceiver)
+        return AdapteeCall(irCall, tmpReceivers)
     }
 
     private fun IrExpression.isSafeToUseWithoutCopying() =
@@ -271,10 +242,6 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
         resolvedCall: ResolvedCall<*>
     ) {
         val adaptedArguments = resolvedCall.valueArguments
-        if (adaptedArguments.isEmpty()) {
-            throw AssertionError("Callable reference with adapted arguments expected: ${resolvedCall.call.callElement.text}")
-        }
-
         var shift = 0
         if (resolvedCall.dispatchReceiver is TransientReceiver) {
             // Unbound callable reference 'A::foo', receiver is passed as a first parameter
@@ -309,13 +276,16 @@ class ReflectionReferencesGenerator(statementGenerator: StatementGenerator) : St
             is DefaultValueArgument ->
                 null
             is VarargValueArgument ->
-                IrVarargImpl(
-                    startOffset, endOffset,
-                    valueParameter.type.toIrType(), valueParameter.varargElementType!!.toIrType(),
-                    resolvedValueArgument.arguments.map {
-                        adaptValueArgument(startOffset, endOffset, it, irAdapterFun, shift)
-                    }
-                )
+                if (resolvedValueArgument.arguments.isEmpty())
+                    null
+                else
+                    IrVarargImpl(
+                        startOffset, endOffset,
+                        valueParameter.type.toIrType(), valueParameter.varargElementType!!.toIrType(),
+                        resolvedValueArgument.arguments.map {
+                            adaptValueArgument(startOffset, endOffset, it, irAdapterFun, shift)
+                        }
+                    )
             is ExpressionValueArgument -> {
                 val valueArgument = resolvedValueArgument.valueArgument!!
 

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/CallableReferenceResolution.kt

@@ -315,6 +315,12 @@ class CallableReferencesCandidateFactory(
             mappedArguments[valueParameter] = ResolvedCallArgument.VarargArgument(varargElements)
         }
 
+        for (valueParameter in descriptor.valueParameters) {
+            if (valueParameter.isVararg && valueParameter !in mappedArguments) {
+                mappedArguments[valueParameter] = ResolvedCallArgument.VarargArgument(emptyList())
+            }
+        }
+
         // lower(Unit!) = Unit
         val returnExpectedType = inputOutputTypes.outputType
 

compiler/testData/codegen/box/callableReference/noReflectionForAdaptedCallableReferences.kt

@@ -0,0 +1,38 @@
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_RUNTIME
+import kotlin.reflect.KCallable
+
+fun checkUnit(label: String, fn: () -> Unit) {
+    if (fn is KCallable<*>) {
+        throw AssertionError("$label is KCallable, ${fn::class.java.simpleName}")
+    }
+}
+
+fun checkAny(label: String, fn: () -> Any) {
+    if (fn is KCallable<*>) {
+        throw AssertionError("$label is KCallable, ${fn::class.java.simpleName}")
+    }
+}
+
+fun withDefaults(a: Int = 1, b: Int = 2) {}
+fun withVarargs(vararg xs: Int) {}
+fun withCoercion() = 1
+
+class CWithDefaults(x: Int = 1, y: Int = 2)
+class CWithVarargs(vararg xs: Int)
+
+fun box(): String {
+    checkUnit("::withDefaults", ::withDefaults)
+    checkUnit("::withVarargs", ::withVarargs)
+    checkUnit("::withCoercion", ::withCoercion)
+
+    checkAny("::CWithDefaults", ::CWithDefaults)
+    checkAny("::CWithVarargs", ::CWithVarargs)
+
+    // TODO KT-37604
+    // checkUnit("::CWithDefaults", ::CWithDefaults)
+    // checkUnit("::CWithVarargs", ::CWithVarargs)
+
+    return "OK"
+}

compiler/testData/ir/irText/expressions/callableReferences/adaptedExtensionFunctions.txt

@@ -44,7 +44,7 @@ FILE fqName:<root> fileName:/adaptedExtensionFunctions.kt
   FUN name:testExtensionVararg visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun use (f: @[ExtensionFunctionType] kotlin.Function2<<root>.C, kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        f: BLOCK type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=null
+        f: FUN_EXPR type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=LAMBDA
           FUN ADAPTER_FOR_CALLABLE_REFERENCE name:extensionVararg visibility:local modality:FINAL <> (p0:<root>.C, p1:kotlin.Int) returnType:kotlin.Unit
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:<root>.C
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p1 index:1 type:kotlin.Int
@@ -52,11 +52,10 @@ FILE fqName:<root> fileName:/adaptedExtensionFunctions.kt
               CALL 'public final fun extensionVararg (i: kotlin.Int, vararg s: kotlin.String): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
                 $receiver: GET_VAR 'p0: <root>.C declared in <root>.testExtensionVararg.extensionVararg' type=<root>.C origin=null
                 i: GET_VAR 'p1: kotlin.Int declared in <root>.testExtensionVararg.extensionVararg' type=kotlin.Int origin=null
-          FUNCTION_REFERENCE 'local final fun extensionVararg (p0: <root>.C, p1: kotlin.Int): kotlin.Unit declared in <root>.testExtensionVararg' type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
   FUN name:testExtensionDefault visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun use (f: @[ExtensionFunctionType] kotlin.Function2<<root>.C, kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        f: BLOCK type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=null
+        f: FUN_EXPR type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=LAMBDA
           FUN ADAPTER_FOR_CALLABLE_REFERENCE name:extensionDefault visibility:local modality:FINAL <> (p0:<root>.C, p1:kotlin.Int) returnType:kotlin.Unit
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:<root>.C
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p1 index:1 type:kotlin.Int
@@ -64,11 +63,10 @@ FILE fqName:<root> fileName:/adaptedExtensionFunctions.kt
               CALL 'public final fun extensionDefault (i: kotlin.Int, s: kotlin.String): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
                 $receiver: GET_VAR 'p0: <root>.C declared in <root>.testExtensionDefault.extensionDefault' type=<root>.C origin=null
                 i: GET_VAR 'p1: kotlin.Int declared in <root>.testExtensionDefault.extensionDefault' type=kotlin.Int origin=null
-          FUNCTION_REFERENCE 'local final fun extensionDefault (p0: <root>.C, p1: kotlin.Int): kotlin.Unit declared in <root>.testExtensionDefault' type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
   FUN name:testExtensionBoth visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun use (f: @[ExtensionFunctionType] kotlin.Function2<<root>.C, kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        f: BLOCK type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=null
+        f: FUN_EXPR type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=LAMBDA
           FUN ADAPTER_FOR_CALLABLE_REFERENCE name:extensionBoth visibility:local modality:FINAL <> (p0:<root>.C, p1:kotlin.Int) returnType:kotlin.Unit
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:<root>.C
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p1 index:1 type:kotlin.Int
@@ -76,4 +74,3 @@ FILE fqName:<root> fileName:/adaptedExtensionFunctions.kt
               CALL 'public final fun extensionBoth (i: kotlin.Int, s: kotlin.String, vararg t: kotlin.String): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
                 $receiver: GET_VAR 'p0: <root>.C declared in <root>.testExtensionBoth.extensionBoth' type=<root>.C origin=null
                 i: GET_VAR 'p1: kotlin.Int declared in <root>.testExtensionBoth.extensionBoth' type=kotlin.Int origin=null
-          FUNCTION_REFERENCE 'local final fun extensionBoth (p0: <root>.C, p1: kotlin.Int): kotlin.Unit declared in <root>.testExtensionBoth' type=kotlin.reflect.KFunction2<<root>.C, kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null

compiler/testData/ir/irText/expressions/callableReferences/adaptedWithCoercionToUnit.fir.txt

@@ -0,0 +1,41 @@
+FILE fqName:<root> fileName:/adaptedWithCoercionToUnit.kt
+  FUN name:useUnit0 visibility:public modality:FINAL <> (fn:kotlin.Function0<kotlin.Unit>) returnType:kotlin.Unit
+    VALUE_PARAMETER name:fn index:0 type:kotlin.Function0<kotlin.Unit>
+    BLOCK_BODY
+  FUN name:useUnit1 visibility:public modality:FINAL <> (fn:kotlin.Function1<kotlin.Int, kotlin.Unit>) returnType:kotlin.Unit
+    VALUE_PARAMETER name:fn index:0 type:kotlin.Function1<kotlin.Int, kotlin.Unit>
+    BLOCK_BODY
+  FUN name:fn0 visibility:public modality:FINAL <> () returnType:kotlin.Int
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun fn0 (): kotlin.Int declared in <root>'
+        CONST Int type=kotlin.Int value=1
+  FUN name:fn1 visibility:public modality:FINAL <> (x:kotlin.Int) returnType:kotlin.Int
+    VALUE_PARAMETER name:x index:0 type:kotlin.Int
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun fn1 (x: kotlin.Int): kotlin.Int declared in <root>'
+        CONST Int type=kotlin.Int value=1
+  FUN name:fnv visibility:public modality:FINAL <> (xs:kotlin.IntArray) returnType:kotlin.Int
+    VALUE_PARAMETER name:xs index:0 type:kotlin.IntArray varargElementType:kotlin.Int [vararg]
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun fnv (vararg xs: kotlin.Int): kotlin.Int declared in <root>'
+        CONST Int type=kotlin.Int value=1
+  FUN name:test0 visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun test0 (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Inapplicable(INAPPLICABLE): [/useUnit0]>#' type=IrErrorType
+          FUNCTION_REFERENCE 'public final fun fn0 (): kotlin.Int declared in <root>' type=kotlin.reflect.KFunction0<kotlin.Int> origin=null reflectionTarget=<same>
+  FUN name:test1 visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun test1 (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Inapplicable(INAPPLICABLE): [/useUnit1]>#' type=IrErrorType
+          FUNCTION_REFERENCE 'public final fun fn1 (x: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Int> origin=null reflectionTarget=<same>
+  FUN name:testV0 visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testV0 (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Inapplicable(INAPPLICABLE): [/useUnit0]>#' type=IrErrorType
+          FUNCTION_REFERENCE 'public final fun fnv (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.reflect.KFunction1<kotlin.IntArray, kotlin.Int> origin=null reflectionTarget=<same>
+  FUN name:testV1 visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testV1 (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Inapplicable(INAPPLICABLE): [/useUnit1]>#' type=IrErrorType
+          FUNCTION_REFERENCE 'public final fun fnv (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.reflect.KFunction1<kotlin.IntArray, kotlin.Int> origin=null reflectionTarget=<same>

compiler/testData/ir/irText/expressions/callableReferences/adaptedWithCoercionToUnit.kt

@@ -0,0 +1,11 @@
+fun useUnit0(fn: () -> Unit) {}
+fun useUnit1(fn: (Int) -> Unit) {}
+
+fun fn0() = 1
+fun fn1(x: Int) = 1
+fun fnv(vararg xs: Int) = 1
+
+fun test0() = useUnit0(::fn0)
+fun test1() = useUnit1(::fn1)
+fun testV0() = useUnit0(::fnv)
+fun testV1() = useUnit1(::fnv)

compiler/testData/ir/irText/expressions/callableReferences/adaptedWithCoercionToUnit.txt

@@ -0,0 +1,62 @@
+FILE fqName:<root> fileName:/adaptedWithCoercionToUnit.kt
+  FUN name:useUnit0 visibility:public modality:FINAL <> (fn:kotlin.Function0<kotlin.Unit>) returnType:kotlin.Unit
+    VALUE_PARAMETER name:fn index:0 type:kotlin.Function0<kotlin.Unit>
+    BLOCK_BODY
+  FUN name:useUnit1 visibility:public modality:FINAL <> (fn:kotlin.Function1<kotlin.Int, kotlin.Unit>) returnType:kotlin.Unit
+    VALUE_PARAMETER name:fn index:0 type:kotlin.Function1<kotlin.Int, kotlin.Unit>
+    BLOCK_BODY
+  FUN name:fn0 visibility:public modality:FINAL <> () returnType:kotlin.Int
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun fn0 (): kotlin.Int declared in <root>'
+        CONST Int type=kotlin.Int value=1
+  FUN name:fn1 visibility:public modality:FINAL <> (x:kotlin.Int) returnType:kotlin.Int
+    VALUE_PARAMETER name:x index:0 type:kotlin.Int
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun fn1 (x: kotlin.Int): kotlin.Int declared in <root>'
+        CONST Int type=kotlin.Int value=1
+  FUN name:fnv visibility:public modality:FINAL <> (xs:kotlin.IntArray) returnType:kotlin.Int
+    VALUE_PARAMETER name:xs index:0 type:kotlin.IntArray varargElementType:kotlin.Int [vararg]
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun fnv (vararg xs: kotlin.Int): kotlin.Int declared in <root>'
+        CONST Int type=kotlin.Int value=1
+  FUN name:test0 visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun test0 (): kotlin.Unit declared in <root>'
+        CALL 'public final fun useUnit0 (fn: kotlin.Function0<kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction0<kotlin.Unit> origin=LAMBDA
+            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fn0 visibility:local modality:FINAL <> () returnType:kotlin.Unit
+              BLOCK_BODY
+                TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
+                  CALL 'public final fun fn0 (): kotlin.Int declared in <root>' type=kotlin.Int origin=null
+  FUN name:test1 visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun test1 (): kotlin.Unit declared in <root>'
+        CALL 'public final fun useUnit1 (fn: kotlin.Function1<kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
+            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fn1 visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
+              VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
+              BLOCK_BODY
+                TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
+                  CALL 'public final fun fn1 (x: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.Int origin=null
+                    x: GET_VAR 'p0: kotlin.Int declared in <root>.test1.fn1' type=kotlin.Int origin=null
+  FUN name:testV0 visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testV0 (): kotlin.Unit declared in <root>'
+        CALL 'public final fun useUnit0 (fn: kotlin.Function0<kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction0<kotlin.Unit> origin=LAMBDA
+            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fnv visibility:local modality:FINAL <> () returnType:kotlin.Unit
+              BLOCK_BODY
+                TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
+                  CALL 'public final fun fnv (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.Int origin=null
+  FUN name:testV1 visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testV1 (): kotlin.Unit declared in <root>'
+        CALL 'public final fun useUnit1 (fn: kotlin.Function1<kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
+            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fnv visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
+              VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
+              BLOCK_BODY
+                TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
+                  CALL 'public final fun fnv (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.Int origin=null
+                    xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
+                      GET_VAR 'p0: kotlin.Int declared in <root>.testV1.fnv' type=kotlin.Int origin=null

compiler/testData/ir/irText/expressions/callableReferences/caoWithAdaptationForSam.txt

@@ -109,7 +109,7 @@ FILE fqName:<root> fileName:/caoWithAdaptationForSam.kt
           GET_OBJECT 'CLASS OBJECT name:A modality:FINAL visibility:public superTypes:[kotlin.Any]' type=<root>.A
         VAR IR_TEMPORARY_VARIABLE name:tmp_1 type:<root>.IFoo [val]
           TYPE_OP type=<root>.IFoo origin=SAM_CONVERSION typeOperand=<root>.IFoo
-            BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+            FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
               FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
                 VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
                 BLOCK_BODY
@@ -117,7 +117,6 @@ FILE fqName:<root> fileName:/caoWithAdaptationForSam.kt
                     CALL 'public final fun withVararg (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.Int origin=null
                       xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                         GET_VAR 'p0: kotlin.Int declared in <root>.test1.withVararg' type=kotlin.Int origin=null
-              FUNCTION_REFERENCE 'local final fun withVararg (p0: kotlin.Int): kotlin.Unit declared in <root>.test1' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
         CALL 'public final fun set (i: <root>.IFoo, newValue: kotlin.Int): kotlin.Unit [operator] declared in <root>' type=kotlin.Unit origin=PLUSEQ
           $receiver: GET_VAR 'val tmp_0: <root>.A [val] declared in <root>.test1' type=<root>.A origin=null
           i: GET_VAR 'val tmp_1: <root>.IFoo [val] declared in <root>.test1' type=<root>.IFoo origin=null
@@ -133,7 +132,7 @@ FILE fqName:<root> fileName:/caoWithAdaptationForSam.kt
           GET_OBJECT 'CLASS OBJECT name:B modality:FINAL visibility:public superTypes:[kotlin.Any]' type=<root>.B
         VAR IR_TEMPORARY_VARIABLE name:tmp_3 type:<root>.IFoo2 [val]
           TYPE_OP type=<root>.IFoo2 origin=SAM_CONVERSION typeOperand=<root>.IFoo2
-            BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+            FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
               FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
                 VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
                 BLOCK_BODY
@@ -141,7 +140,6 @@ FILE fqName:<root> fileName:/caoWithAdaptationForSam.kt
                     CALL 'public final fun withVararg (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.Int origin=null
                       xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                         GET_VAR 'p0: kotlin.Int declared in <root>.test2.withVararg' type=kotlin.Int origin=null
-              FUNCTION_REFERENCE 'local final fun withVararg (p0: kotlin.Int): kotlin.Unit declared in <root>.test2' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
         CALL 'public final fun set (i: <root>.IFoo2, newValue: kotlin.Int): kotlin.Unit [operator] declared in <root>' type=kotlin.Unit origin=PLUSEQ
           $receiver: GET_VAR 'val tmp_2: <root>.B [val] declared in <root>.test2' type=<root>.B origin=null
           i: GET_VAR 'val tmp_3: <root>.IFoo2 [val] declared in <root>.test2' type=<root>.IFoo2 origin=null

compiler/testData/ir/irText/expressions/callableReferences/constructorWithAdaptedArguments.txt

@@ -70,7 +70,7 @@ FILE fqName:<root> fileName:/constructorWithAdaptedArguments.kt
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testConstructor (): kotlin.Any declared in <root>'
         CALL 'public final fun use (fn: kotlin.Function1<kotlin.Int, kotlin.Any>): kotlin.Any declared in <root>' type=kotlin.Any origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, <root>.C> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, <root>.C> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:<init> visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:<root>.C
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
@@ -78,13 +78,12 @@ FILE fqName:<root> fileName:/constructorWithAdaptedArguments.kt
                   CONSTRUCTOR_CALL 'public constructor <init> (vararg xs: kotlin.Int) [primary] declared in <root>.C' type=<root>.C origin=null
                     xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                       GET_VAR 'p0: kotlin.Int declared in <root>.testConstructor.<init>' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun <init> (p0: kotlin.Int): <root>.C declared in <root>.testConstructor' type=kotlin.reflect.KFunction1<kotlin.Int, <root>.C> origin=null reflectionTarget=null
   FUN name:testInnerClassConstructor visibility:public modality:FINAL <> (outer:<root>.Outer) returnType:kotlin.Any
     VALUE_PARAMETER name:outer index:0 type:<root>.Outer
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testInnerClassConstructor (outer: <root>.Outer): kotlin.Any declared in <root>'
         CALL 'public final fun use (fn: kotlin.Function1<kotlin.Int, kotlin.Any>): kotlin.Any declared in <root>' type=kotlin.Any origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, <root>.Outer.Inner> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, <root>.Outer.Inner> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:<init> visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:<root>.Outer.Inner
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
@@ -93,7 +92,6 @@ FILE fqName:<root> fileName:/constructorWithAdaptedArguments.kt
                     $outer: GET_VAR 'outer: <root>.Outer declared in <root>.testInnerClassConstructor' type=<root>.Outer origin=null
                     xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                       GET_VAR 'p0: kotlin.Int declared in <root>.testInnerClassConstructor.<init>' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun <init> (p0: kotlin.Int): <root>.Outer.Inner declared in <root>.testInnerClassConstructor' type=kotlin.reflect.KFunction1<kotlin.Int, <root>.Outer.Inner> origin=null reflectionTarget=null
   FUN name:testInnerClassConstructorCapturingOuter visibility:public modality:FINAL <> () returnType:kotlin.Any
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testInnerClassConstructorCapturingOuter (): kotlin.Any declared in <root>'
@@ -101,12 +99,12 @@ FILE fqName:<root> fileName:/constructorWithAdaptedArguments.kt
           fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, <root>.Outer.Inner> origin=null
             VAR IR_TEMPORARY_VARIABLE name:tmp_0 type:<root>.Outer [val]
               CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.Outer' type=<root>.Outer origin=null
-            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:<init> visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:<root>.Outer.Inner
-              VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
-              BLOCK_BODY
-                RETURN type=kotlin.Nothing from='local final fun <init> (p0: kotlin.Int): <root>.Outer.Inner declared in <root>.testInnerClassConstructorCapturingOuter'
-                  CONSTRUCTOR_CALL 'public constructor <init> (vararg xs: kotlin.Int) [primary] declared in <root>.Outer.Inner' type=<root>.Outer.Inner origin=null
-                    $outer: GET_VAR 'val tmp_0: <root>.Outer [val] declared in <root>.testInnerClassConstructorCapturingOuter' type=<root>.Outer origin=null
-                    xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
-                      GET_VAR 'p0: kotlin.Int declared in <root>.testInnerClassConstructorCapturingOuter.<init>' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun <init> (p0: kotlin.Int): <root>.Outer.Inner declared in <root>.testInnerClassConstructorCapturingOuter' type=kotlin.reflect.KFunction1<kotlin.Int, <root>.Outer.Inner> origin=null reflectionTarget=null
+            FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, <root>.Outer.Inner> origin=LAMBDA
+              FUN ADAPTER_FOR_CALLABLE_REFERENCE name:<init> visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:<root>.Outer.Inner
+                VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
+                BLOCK_BODY
+                  RETURN type=kotlin.Nothing from='local final fun <init> (p0: kotlin.Int): <root>.Outer.Inner declared in <root>.testInnerClassConstructorCapturingOuter'
+                    CONSTRUCTOR_CALL 'public constructor <init> (vararg xs: kotlin.Int) [primary] declared in <root>.Outer.Inner' type=<root>.Outer.Inner origin=null
+                      $outer: GET_VAR 'val tmp_0: <root>.Outer [val] declared in <root>.testInnerClassConstructorCapturingOuter' type=<root>.Outer origin=null
+                      xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
+                        GET_VAR 'p0: kotlin.Int declared in <root>.testInnerClassConstructorCapturingOuter.<init>' type=kotlin.Int origin=null

compiler/testData/ir/irText/expressions/callableReferences/kt37131.txt

@@ -49,19 +49,17 @@ FILE fqName:<root> fileName:/kt37131.kt
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testFn (): kotlin.Any declared in <root>'
         CALL 'public final fun use (fn: kotlin.Function0<kotlin.Any>): kotlin.Any declared in <root>' type=kotlin.Any origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction0<kotlin.String> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction0<kotlin.String> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:foo visibility:local modality:FINAL <> () returnType:kotlin.String
               BLOCK_BODY
                 RETURN type=kotlin.Nothing from='local final fun foo (): kotlin.String declared in <root>.testFn'
                   CALL 'public final fun foo (x: kotlin.String): kotlin.String declared in <root>' type=kotlin.String origin=null
-            FUNCTION_REFERENCE 'local final fun foo (): kotlin.String declared in <root>.testFn' type=kotlin.reflect.KFunction0<kotlin.String> origin=null reflectionTarget=null
   FUN name:testCtor visibility:public modality:FINAL <> () returnType:kotlin.Any
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testCtor (): kotlin.Any declared in <root>'
         CALL 'public final fun use (fn: kotlin.Function0<kotlin.Any>): kotlin.Any declared in <root>' type=kotlin.Any origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction0<<root>.C> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction0<<root>.C> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:<init> visibility:local modality:FINAL <> () returnType:<root>.C
               BLOCK_BODY
                 RETURN type=kotlin.Nothing from='local final fun <init> (): <root>.C declared in <root>.testCtor'
                   CONSTRUCTOR_CALL 'public constructor <init> (x: kotlin.String) [primary] declared in <root>.C' type=<root>.C origin=null
-            FUNCTION_REFERENCE 'local final fun <init> (): <root>.C declared in <root>.testCtor' type=kotlin.reflect.KFunction0<<root>.C> origin=null reflectionTarget=null

compiler/testData/ir/irText/expressions/callableReferences/unboundMemberReferenceWithAdaptedArguments.txt

@@ -60,7 +60,7 @@ FILE fqName:<root> fileName:/unboundMemberReferenceWithAdaptedArguments.kt
   FUN name:testUnbound visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun use1 (fn: kotlin.Function2<<root>.A, kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        fn: BLOCK type=kotlin.reflect.KFunction2<<root>.A, kotlin.Int, kotlin.Unit> origin=null
+        fn: FUN_EXPR type=kotlin.reflect.KFunction2<<root>.A, kotlin.Int, kotlin.Unit> origin=LAMBDA
           FUN ADAPTER_FOR_CALLABLE_REFERENCE name:foo visibility:local modality:FINAL <> (p0:<root>.A, p1:kotlin.Int) returnType:kotlin.Unit
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:<root>.A
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p1 index:1 type:kotlin.Int
@@ -70,12 +70,11 @@ FILE fqName:<root> fileName:/unboundMemberReferenceWithAdaptedArguments.kt
                   $this: GET_VAR 'p0: <root>.A declared in <root>.testUnbound.foo' type=<root>.A origin=null
                   xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                     GET_VAR 'p1: kotlin.Int declared in <root>.testUnbound.foo' type=kotlin.Int origin=null
-          FUNCTION_REFERENCE 'local final fun foo (p0: <root>.A, p1: kotlin.Int): kotlin.Unit declared in <root>.testUnbound' type=kotlin.reflect.KFunction2<<root>.A, kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
   FUN name:testBound visibility:public modality:FINAL <> (a:<root>.A) returnType:kotlin.Unit
     VALUE_PARAMETER name:a index:0 type:<root>.A
     BLOCK_BODY
       CALL 'public final fun use2 (fn: kotlin.Function1<kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+        fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
           FUN ADAPTER_FOR_CALLABLE_REFERENCE name:foo visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
             BLOCK_BODY
@@ -84,11 +83,10 @@ FILE fqName:<root> fileName:/unboundMemberReferenceWithAdaptedArguments.kt
                   $this: GET_VAR 'a: <root>.A declared in <root>.testBound' type=<root>.A origin=null
                   xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                     GET_VAR 'p0: kotlin.Int declared in <root>.testBound.foo' type=kotlin.Int origin=null
-          FUNCTION_REFERENCE 'local final fun foo (p0: kotlin.Int): kotlin.Unit declared in <root>.testBound' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
   FUN name:testObject visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun use2 (fn: kotlin.Function1<kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+        fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
           FUN ADAPTER_FOR_CALLABLE_REFERENCE name:foo visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
             BLOCK_BODY
@@ -97,4 +95,3 @@ FILE fqName:<root> fileName:/unboundMemberReferenceWithAdaptedArguments.kt
                   $this: GET_OBJECT 'CLASS OBJECT name:Obj modality:FINAL visibility:public superTypes:[<root>.A]' type=<root>.Obj
                   xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                     GET_VAR 'p0: kotlin.Int declared in <root>.testObject.foo' type=kotlin.Int origin=null
-          FUNCTION_REFERENCE 'local final fun foo (p0: kotlin.Int): kotlin.Unit declared in <root>.testObject' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null

compiler/testData/ir/irText/expressions/callableReferences/withAdaptationForSam.txt

@@ -29,7 +29,7 @@ FILE fqName:<root> fileName:/withAdaptationForSam.kt
     BLOCK_BODY
       CALL 'public final fun useFoo (foo: <root>.IFoo): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
         foo: TYPE_OP type=<root>.IFoo origin=SAM_CONVERSION typeOperand=<root>.IFoo
-          BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+          FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
@@ -37,4 +37,3 @@ FILE fqName:<root> fileName:/withAdaptationForSam.kt
                   CALL 'public final fun withVararg (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.Int origin=null
                     xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                       GET_VAR 'p0: kotlin.Int declared in <root>.test.withVararg' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun withVararg (p0: kotlin.Int): kotlin.Unit declared in <root>.test' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null

compiler/testData/ir/irText/expressions/callableReferences/withAdaptedArguments.fir.txt

@@ -6,6 +6,12 @@ FILE fqName:<root> fileName:/withAdaptedArguments.kt
         CALL 'public abstract fun invoke (p1: P1 of kotlin.Function1): R of kotlin.Function1 [operator] declared in kotlin.Function1' type=kotlin.String origin=INVOKE
           $this: GET_VAR 'fn: kotlin.Function1<kotlin.Int, kotlin.String> declared in <root>.use' type=kotlin.Function1<kotlin.Int, kotlin.String> origin=null
           p1: CONST Int type=kotlin.Int value=1
+  FUN name:use0 visibility:public modality:FINAL <> (fn:kotlin.Function0<kotlin.String>) returnType:kotlin.String
+    VALUE_PARAMETER name:fn index:0 type:kotlin.Function0<kotlin.String>
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun use0 (fn: kotlin.Function0<kotlin.String>): kotlin.String declared in <root>'
+        CALL 'public abstract fun invoke (): R of kotlin.Function0 [operator] declared in kotlin.Function0' type=kotlin.String origin=INVOKE
+          $this: GET_VAR 'fn: kotlin.Function0<kotlin.String> declared in <root>.use0' type=kotlin.Function0<kotlin.String> origin=null
   FUN name:coerceToUnit visibility:public modality:FINAL <> (fn:kotlin.Function1<kotlin.Int, kotlin.Unit>) returnType:kotlin.Unit
     VALUE_PARAMETER name:fn index:0 type:kotlin.Function1<kotlin.Int, kotlin.Unit>
     BLOCK_BODY
@@ -17,6 +23,16 @@ FILE fqName:<root> fileName:/withAdaptedArguments.kt
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun fnWithDefault (a: kotlin.Int, b: kotlin.Int): kotlin.String declared in <root>'
         CONST String type=kotlin.String value="abc"
+  FUN name:fnWithDefaults visibility:public modality:FINAL <> (a:kotlin.Int, b:kotlin.Int) returnType:kotlin.String
+    VALUE_PARAMETER name:a index:0 type:kotlin.Int
+      EXPRESSION_BODY
+        CONST Int type=kotlin.Int value=1
+    VALUE_PARAMETER name:b index:1 type:kotlin.Int
+      EXPRESSION_BODY
+        CONST Int type=kotlin.Int value=2
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun fnWithDefaults (a: kotlin.Int, b: kotlin.Int): kotlin.String declared in <root>'
+        CONST String type=kotlin.String value=""
   FUN name:fnWithVarargs visibility:public modality:FINAL <> (xs:kotlin.IntArray) returnType:kotlin.String
     VALUE_PARAMETER name:xs index:0 type:kotlin.IntArray varargElementType:kotlin.Int [vararg]
     BLOCK_BODY
@@ -68,3 +84,13 @@ FILE fqName:<root> fileName:/withAdaptedArguments.kt
         ERROR_CALL 'Unresolved reference: <Inapplicable(INAPPLICABLE): [/use]>#' type=IrErrorType
           FUNCTION_REFERENCE 'public final fun importedObjectMemberWithVarargs (vararg xs: kotlin.Int): kotlin.String declared in <root>.Host' type=kotlin.reflect.KFunction1<kotlin.IntArray, kotlin.String> origin=null reflectionTarget=<same>
             $this: GET_OBJECT 'CLASS OBJECT name:Host modality:FINAL visibility:public superTypes:[kotlin.Any]' type=<root>.Host
+  FUN name:testDefault0 visibility:public modality:FINAL <> () returnType:kotlin.String
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testDefault0 (): kotlin.String declared in <root>'
+        CALL 'public final fun use0 (fn: kotlin.Function0<kotlin.String>): kotlin.String declared in <root>' type=kotlin.String origin=null
+          fn: FUNCTION_REFERENCE 'public final fun fnWithDefaults (a: kotlin.Int, b: kotlin.Int): kotlin.String declared in <root>' type=kotlin.reflect.KFunction0<kotlin.String> origin=null reflectionTarget=<same>
+  FUN name:testVararg0 visibility:public modality:FINAL <> () returnType:IrErrorType
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testVararg0 (): IrErrorType declared in <root>'
+        ERROR_CALL 'Unresolved reference: <Inapplicable(INAPPLICABLE): [/use0]>#' type=IrErrorType
+          FUNCTION_REFERENCE 'public final fun fnWithVarargs (vararg xs: kotlin.Int): kotlin.String declared in <root>' type=kotlin.reflect.KFunction1<kotlin.IntArray, kotlin.String> origin=null reflectionTarget=<same>

compiler/testData/ir/irText/expressions/callableReferences/withAdaptedArguments.kt

@@ -3,10 +3,14 @@ import Host.importedObjectMemberWithVarargs
 
 fun use(fn: (Int) -> String) = fn(1)
 
+fun use0(fn: () -> String) = fn()
+
 fun coerceToUnit(fn: (Int) -> Unit) {}
 
 fun fnWithDefault(a: Int, b: Int = 42) = "abc"
 
+fun fnWithDefaults(a: Int = 1, b: Int = 2) = ""
+
 fun fnWithVarargs(vararg xs: Int) = "abc"
 
 object Host {
@@ -19,4 +23,8 @@ fun testVararg() = use(::fnWithVarargs)
 
 fun testCoercionToUnit() = coerceToUnit(::fnWithDefault)
 
-fun testImportedObjectMember() = use(::importedObjectMemberWithVarargs)
+fun testImportedObjectMember() = use(::importedObjectMemberWithVarargs)
+
+fun testDefault0() = use0(::fnWithDefaults)
+
+fun testVararg0() = use0(::fnWithVarargs)

compiler/testData/ir/irText/expressions/callableReferences/withAdaptedArguments.txt

@@ -6,6 +6,12 @@ FILE fqName:<root> fileName:/withAdaptedArguments.kt
         CALL 'public abstract fun invoke (p1: P1 of kotlin.Function1): R of kotlin.Function1 [operator] declared in kotlin.Function1' type=kotlin.String origin=INVOKE
           $this: GET_VAR 'fn: kotlin.Function1<kotlin.Int, kotlin.String> declared in <root>.use' type=kotlin.Function1<kotlin.Int, kotlin.String> origin=VARIABLE_AS_FUNCTION
           p1: CONST Int type=kotlin.Int value=1
+  FUN name:use0 visibility:public modality:FINAL <> (fn:kotlin.Function0<kotlin.String>) returnType:kotlin.String
+    VALUE_PARAMETER name:fn index:0 type:kotlin.Function0<kotlin.String>
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun use0 (fn: kotlin.Function0<kotlin.String>): kotlin.String declared in <root>'
+        CALL 'public abstract fun invoke (): R of kotlin.Function0 [operator] declared in kotlin.Function0' type=kotlin.String origin=INVOKE
+          $this: GET_VAR 'fn: kotlin.Function0<kotlin.String> declared in <root>.use0' type=kotlin.Function0<kotlin.String> origin=VARIABLE_AS_FUNCTION
   FUN name:coerceToUnit visibility:public modality:FINAL <> (fn:kotlin.Function1<kotlin.Int, kotlin.Unit>) returnType:kotlin.Unit
     VALUE_PARAMETER name:fn index:0 type:kotlin.Function1<kotlin.Int, kotlin.Unit>
     BLOCK_BODY
@@ -17,6 +23,16 @@ FILE fqName:<root> fileName:/withAdaptedArguments.kt
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun fnWithDefault (a: kotlin.Int, b: kotlin.Int): kotlin.String declared in <root>'
         CONST String type=kotlin.String value="abc"
+  FUN name:fnWithDefaults visibility:public modality:FINAL <> (a:kotlin.Int, b:kotlin.Int) returnType:kotlin.String
+    VALUE_PARAMETER name:a index:0 type:kotlin.Int
+      EXPRESSION_BODY
+        CONST Int type=kotlin.Int value=1
+    VALUE_PARAMETER name:b index:1 type:kotlin.Int
+      EXPRESSION_BODY
+        CONST Int type=kotlin.Int value=2
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun fnWithDefaults (a: kotlin.Int, b: kotlin.Int): kotlin.String declared in <root>'
+        CONST String type=kotlin.String value=""
   FUN name:fnWithVarargs visibility:public modality:FINAL <> (xs:kotlin.IntArray) returnType:kotlin.String
     VALUE_PARAMETER name:xs index:0 type:kotlin.IntArray varargElementType:kotlin.Int [vararg]
     BLOCK_BODY
@@ -51,19 +67,18 @@ FILE fqName:<root> fileName:/withAdaptedArguments.kt
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testDefault (): kotlin.String declared in <root>'
         CALL 'public final fun use (fn: kotlin.Function1<kotlin.Int, kotlin.String>): kotlin.String declared in <root>' type=kotlin.String origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fnWithDefault visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.String
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
                 RETURN type=kotlin.Nothing from='local final fun fnWithDefault (p0: kotlin.Int): kotlin.String declared in <root>.testDefault'
                   CALL 'public final fun fnWithDefault (a: kotlin.Int, b: kotlin.Int): kotlin.String declared in <root>' type=kotlin.String origin=null
                     a: GET_VAR 'p0: kotlin.Int declared in <root>.testDefault.fnWithDefault' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun fnWithDefault (p0: kotlin.Int): kotlin.String declared in <root>.testDefault' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=null reflectionTarget=null
   FUN name:testVararg visibility:public modality:FINAL <> () returnType:kotlin.String
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testVararg (): kotlin.String declared in <root>'
         CALL 'public final fun use (fn: kotlin.Function1<kotlin.Int, kotlin.String>): kotlin.String declared in <root>' type=kotlin.String origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fnWithVarargs visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.String
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
@@ -71,24 +86,22 @@ FILE fqName:<root> fileName:/withAdaptedArguments.kt
                   CALL 'public final fun fnWithVarargs (vararg xs: kotlin.Int): kotlin.String declared in <root>' type=kotlin.String origin=null
                     xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                       GET_VAR 'p0: kotlin.Int declared in <root>.testVararg.fnWithVarargs' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun fnWithVarargs (p0: kotlin.Int): kotlin.String declared in <root>.testVararg' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=null reflectionTarget=null
   FUN name:testCoercionToUnit visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testCoercionToUnit (): kotlin.Unit declared in <root>'
         CALL 'public final fun coerceToUnit (fn: kotlin.Function1<kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fnWithDefault visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
                 TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
                   CALL 'public final fun fnWithDefault (a: kotlin.Int, b: kotlin.Int): kotlin.String declared in <root>' type=kotlin.String origin=null
                     a: GET_VAR 'p0: kotlin.Int declared in <root>.testCoercionToUnit.fnWithDefault' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun fnWithDefault (p0: kotlin.Int): kotlin.Unit declared in <root>.testCoercionToUnit' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
   FUN name:testImportedObjectMember visibility:public modality:FINAL <> () returnType:kotlin.String
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testImportedObjectMember (): kotlin.String declared in <root>'
         CALL 'public final fun use (fn: kotlin.Function1<kotlin.Int, kotlin.String>): kotlin.String declared in <root>' type=kotlin.String origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:importedObjectMemberWithVarargs visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.String
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
@@ -97,4 +110,21 @@ FILE fqName:<root> fileName:/withAdaptedArguments.kt
                     $this: GET_OBJECT 'CLASS OBJECT name:Host modality:FINAL visibility:public superTypes:[kotlin.Any]' type=<root>.Host
                     xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                       GET_VAR 'p0: kotlin.Int declared in <root>.testImportedObjectMember.importedObjectMemberWithVarargs' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun importedObjectMemberWithVarargs (p0: kotlin.Int): kotlin.String declared in <root>.testImportedObjectMember' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.String> origin=null reflectionTarget=null
+  FUN name:testDefault0 visibility:public modality:FINAL <> () returnType:kotlin.String
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testDefault0 (): kotlin.String declared in <root>'
+        CALL 'public final fun use0 (fn: kotlin.Function0<kotlin.String>): kotlin.String declared in <root>' type=kotlin.String origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction0<kotlin.String> origin=LAMBDA
+            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fnWithDefaults visibility:local modality:FINAL <> () returnType:kotlin.String
+              BLOCK_BODY
+                RETURN type=kotlin.Nothing from='local final fun fnWithDefaults (): kotlin.String declared in <root>.testDefault0'
+                  CALL 'public final fun fnWithDefaults (a: kotlin.Int, b: kotlin.Int): kotlin.String declared in <root>' type=kotlin.String origin=null
+  FUN name:testVararg0 visibility:public modality:FINAL <> () returnType:kotlin.String
+    BLOCK_BODY
+      RETURN type=kotlin.Nothing from='public final fun testVararg0 (): kotlin.String declared in <root>'
+        CALL 'public final fun use0 (fn: kotlin.Function0<kotlin.String>): kotlin.String declared in <root>' type=kotlin.String origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction0<kotlin.String> origin=LAMBDA
+            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:fnWithVarargs visibility:local modality:FINAL <> () returnType:kotlin.String
+              BLOCK_BODY
+                RETURN type=kotlin.Nothing from='local final fun fnWithVarargs (): kotlin.String declared in <root>.testVararg0'
+                  CALL 'public final fun fnWithVarargs (vararg xs: kotlin.Int): kotlin.String declared in <root>' type=kotlin.String origin=null

compiler/testData/ir/irText/expressions/callableReferences/withArgumentAdaptationAndReceiver.txt

@@ -21,7 +21,7 @@ FILE fqName:<root> fileName:/withArgumentAdaptationAndReceiver.kt
       $this: VALUE_PARAMETER name:<this> type:<root>.Host
       BLOCK_BODY
         CALL 'public final fun use (fn: kotlin.Function1<kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
@@ -30,14 +30,13 @@ FILE fqName:<root> fileName:/withArgumentAdaptationAndReceiver.kt
                     $this: GET_VAR '<this>: <root>.Host declared in <root>.Host.testImplicitThis' type=<root>.Host origin=null
                     xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                       GET_VAR 'p0: kotlin.Int declared in <root>.Host.testImplicitThis.withVararg' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun withVararg (p0: kotlin.Int): kotlin.Unit declared in <root>.Host.testImplicitThis' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
     FUN name:testBoundReceiverLocalVal visibility:public modality:FINAL <> ($this:<root>.Host) returnType:kotlin.Unit
       $this: VALUE_PARAMETER name:<this> type:<root>.Host
       BLOCK_BODY
         VAR name:h type:<root>.Host [val]
           CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.Host' type=<root>.Host origin=null
         CALL 'public final fun use (fn: kotlin.Function1<kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
@@ -46,7 +45,6 @@ FILE fqName:<root> fileName:/withArgumentAdaptationAndReceiver.kt
                     $this: GET_VAR 'val h: <root>.Host [val] declared in <root>.Host.testBoundReceiverLocalVal' type=<root>.Host origin=null
                     xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                       GET_VAR 'p0: kotlin.Int declared in <root>.Host.testBoundReceiverLocalVal.withVararg' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun withVararg (p0: kotlin.Int): kotlin.Unit declared in <root>.Host.testBoundReceiverLocalVal' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
     FUN name:testBoundReceiverLocalVar visibility:public modality:FINAL <> ($this:<root>.Host) returnType:kotlin.Unit
       $this: VALUE_PARAMETER name:<this> type:<root>.Host
       BLOCK_BODY
@@ -56,21 +54,21 @@ FILE fqName:<root> fileName:/withArgumentAdaptationAndReceiver.kt
           fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
             VAR IR_TEMPORARY_VARIABLE name:tmp_0 type:<root>.Host [val]
               GET_VAR 'var h: <root>.Host [var] declared in <root>.Host.testBoundReceiverLocalVar' type=<root>.Host origin=null
-            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
-              VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
-              BLOCK_BODY
-                TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-                  CALL 'public final fun withVararg (vararg xs: kotlin.Int): kotlin.String declared in <root>.Host' type=kotlin.String origin=null
-                    $this: GET_VAR 'val tmp_0: <root>.Host [val] declared in <root>.Host.testBoundReceiverLocalVar' type=<root>.Host origin=null
-                    xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
-                      GET_VAR 'p0: kotlin.Int declared in <root>.Host.testBoundReceiverLocalVar.withVararg' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun withVararg (p0: kotlin.Int): kotlin.Unit declared in <root>.Host.testBoundReceiverLocalVar' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
+            FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
+              FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
+                VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
+                BLOCK_BODY
+                  TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
+                    CALL 'public final fun withVararg (vararg xs: kotlin.Int): kotlin.String declared in <root>.Host' type=kotlin.String origin=null
+                      $this: GET_VAR 'val tmp_0: <root>.Host [val] declared in <root>.Host.testBoundReceiverLocalVar' type=<root>.Host origin=null
+                      xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
+                        GET_VAR 'p0: kotlin.Int declared in <root>.Host.testBoundReceiverLocalVar.withVararg' type=kotlin.Int origin=null
     FUN name:testBoundReceiverParameter visibility:public modality:FINAL <> ($this:<root>.Host, h:<root>.Host) returnType:kotlin.Unit
       $this: VALUE_PARAMETER name:<this> type:<root>.Host
       VALUE_PARAMETER name:h index:0 type:<root>.Host
       BLOCK_BODY
         CALL 'public final fun use (fn: kotlin.Function1<kotlin.Int, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-          fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+          fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
             FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
               VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
               BLOCK_BODY
@@ -79,7 +77,6 @@ FILE fqName:<root> fileName:/withArgumentAdaptationAndReceiver.kt
                     $this: GET_VAR 'h: <root>.Host declared in <root>.Host.testBoundReceiverParameter' type=<root>.Host origin=null
                     xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                       GET_VAR 'p0: kotlin.Int declared in <root>.Host.testBoundReceiverParameter.withVararg' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun withVararg (p0: kotlin.Int): kotlin.Unit declared in <root>.Host.testBoundReceiverParameter' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
     FUN name:testBoundReceiverExpression visibility:public modality:FINAL <> ($this:<root>.Host) returnType:kotlin.Unit
       $this: VALUE_PARAMETER name:<this> type:<root>.Host
       BLOCK_BODY
@@ -87,15 +84,15 @@ FILE fqName:<root> fileName:/withArgumentAdaptationAndReceiver.kt
           fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
             VAR IR_TEMPORARY_VARIABLE name:tmp_1 type:<root>.Host [val]
               CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.Host' type=<root>.Host origin=null
-            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
-              VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
-              BLOCK_BODY
-                TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-                  CALL 'public final fun withVararg (vararg xs: kotlin.Int): kotlin.String declared in <root>.Host' type=kotlin.String origin=null
-                    $this: GET_VAR 'val tmp_1: <root>.Host [val] declared in <root>.Host.testBoundReceiverExpression' type=<root>.Host origin=null
-                    xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
-                      GET_VAR 'p0: kotlin.Int declared in <root>.Host.testBoundReceiverExpression.withVararg' type=kotlin.Int origin=null
-            FUNCTION_REFERENCE 'local final fun withVararg (p0: kotlin.Int): kotlin.Unit declared in <root>.Host.testBoundReceiverExpression' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null
+            FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
+              FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVararg visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
+                VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
+                BLOCK_BODY
+                  TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
+                    CALL 'public final fun withVararg (vararg xs: kotlin.Int): kotlin.String declared in <root>.Host' type=kotlin.String origin=null
+                      $this: GET_VAR 'val tmp_1: <root>.Host [val] declared in <root>.Host.testBoundReceiverExpression' type=<root>.Host origin=null
+                      xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
+                        GET_VAR 'p0: kotlin.Int declared in <root>.Host.testBoundReceiverExpression.withVararg' type=kotlin.Int origin=null
     FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
       overridden:
         public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any

compiler/testData/ir/irText/expressions/callableReferences/withVarargViewedAsArray.txt

@@ -61,7 +61,7 @@ FILE fqName:<root> fileName:/withVarargViewedAsArray.kt
   FUN name:testPlainArgs visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun usePlainArgs (fn: kotlin.Function2<kotlin.Int, kotlin.Int, kotlin.Int>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        fn: BLOCK type=kotlin.reflect.KFunction2<kotlin.Int, kotlin.Int, kotlin.Int> origin=null
+        fn: FUN_EXPR type=kotlin.reflect.KFunction2<kotlin.Int, kotlin.Int, kotlin.Int> origin=LAMBDA
           FUN ADAPTER_FOR_CALLABLE_REFERENCE name:sum visibility:local modality:FINAL <> (p0:kotlin.Int, p1:kotlin.Int) returnType:kotlin.Int
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p1 index:1 type:kotlin.Int
@@ -71,7 +71,6 @@ FILE fqName:<root> fileName:/withVarargViewedAsArray.kt
                   args: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                     GET_VAR 'p0: kotlin.Int declared in <root>.testPlainArgs.sum' type=kotlin.Int origin=null
                     GET_VAR 'p1: kotlin.Int declared in <root>.testPlainArgs.sum' type=kotlin.Int origin=null
-          FUNCTION_REFERENCE 'local final fun sum (p0: kotlin.Int, p1: kotlin.Int): kotlin.Int declared in <root>.testPlainArgs' type=kotlin.reflect.KFunction2<kotlin.Int, kotlin.Int, kotlin.Int> origin=null reflectionTarget=null
   FUN name:testPrimitiveArrayAsVararg visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun usePrimitiveArray (fn: kotlin.Function1<kotlin.IntArray, kotlin.Int>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
@@ -83,7 +82,7 @@ FILE fqName:<root> fileName:/withVarargViewedAsArray.kt
   FUN name:testArrayAndDefaults visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun useStringArray (fn: kotlin.Function1<kotlin.Array<kotlin.String>, kotlin.Unit>): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        fn: BLOCK type=kotlin.reflect.KFunction1<kotlin.Array<out kotlin.String>, kotlin.Unit> origin=null
+        fn: FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Array<out kotlin.String>, kotlin.Unit> origin=LAMBDA
           FUN ADAPTER_FOR_CALLABLE_REFERENCE name:zap visibility:local modality:FINAL <> (p0:kotlin.Array<out kotlin.String>) returnType:kotlin.Unit
             VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Array<out kotlin.String>
             BLOCK_BODY
@@ -91,4 +90,3 @@ FILE fqName:<root> fileName:/withVarargViewedAsArray.kt
                 b: VARARG type=kotlin.Array<out kotlin.String> varargElementType=kotlin.String
                   SPREAD_ELEMENT
                     GET_VAR 'p0: kotlin.Array<out kotlin.String> declared in <root>.testArrayAndDefaults.zap' type=kotlin.Array<out kotlin.String> origin=null
-          FUNCTION_REFERENCE 'local final fun zap (p0: kotlin.Array<out kotlin.String>): kotlin.Unit declared in <root>.testArrayAndDefaults' type=kotlin.reflect.KFunction1<kotlin.Array<out kotlin.String>, kotlin.Unit> origin=null reflectionTarget=null

compiler/testData/ir/irText/expressions/funInterface/samConversionInVarargs.txt

@@ -66,7 +66,7 @@ FILE fqName:<root> fileName:/samConversionInVarargs.kt
       CALL 'public final fun useVararg (vararg foos: <root>.IFoo): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
         foos: VARARG type=kotlin.Array<out <root>.IFoo> varargElementType=<root>.IFoo
           TYPE_OP type=<root>.IFoo origin=SAM_CONVERSION typeOperand=<root>.IFoo
-            BLOCK type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
+            FUN_EXPR type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=LAMBDA
               FUN ADAPTER_FOR_CALLABLE_REFERENCE name:withVarargOfInt visibility:local modality:FINAL <> (p0:kotlin.Int) returnType:kotlin.Unit
                 VALUE_PARAMETER ADAPTER_PARAMETER_FOR_CALLABLE_REFERENCE name:p0 index:0 type:kotlin.Int
                 BLOCK_BODY
@@ -74,4 +74,3 @@ FILE fqName:<root> fileName:/samConversionInVarargs.kt
                     CALL 'public final fun withVarargOfInt (vararg xs: kotlin.Int): kotlin.String declared in <root>' type=kotlin.String origin=null
                       xs: VARARG type=kotlin.IntArray varargElementType=kotlin.Int
                         GET_VAR 'p0: kotlin.Int declared in <root>.testAdaptedCR.withVarargOfInt' type=kotlin.Int origin=null
-              FUNCTION_REFERENCE 'local final fun withVarargOfInt (p0: kotlin.Int): kotlin.Unit declared in <root>.testAdaptedCR' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null reflectionTarget=null

compiler/testData/ir/irText/expressions/funInterface/samConversionOnCallableReference.txt

@@ -35,7 +35,11 @@ FILE fqName:<root> fileName:/samConversionOnCallableReference.kt
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun testSamCosntructorOnAdapted (): <root>.KRunnable declared in <root>'
         TYPE_OP type=<root>.KRunnable origin=SAM_CONVERSION typeOperand=<root>.KRunnable
-          FUNCTION_REFERENCE 'public final fun foo1 (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.reflect.KFunction0<kotlin.Unit> origin=null reflectionTarget=<same>
+          FUN_EXPR type=kotlin.reflect.KFunction0<kotlin.Unit> origin=LAMBDA
+            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:foo1 visibility:local modality:FINAL <> () returnType:kotlin.Unit
+              BLOCK_BODY
+                TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
+                  CALL 'public final fun foo1 (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.Int origin=null
   FUN name:testSamConversion visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun use (r: <root>.KRunnable): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
@@ -45,4 +49,8 @@ FILE fqName:<root> fileName:/samConversionOnCallableReference.kt
     BLOCK_BODY
       CALL 'public final fun use (r: <root>.KRunnable): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
         r: TYPE_OP type=<root>.KRunnable origin=SAM_CONVERSION typeOperand=<root>.KRunnable
-          FUNCTION_REFERENCE 'public final fun foo1 (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.reflect.KFunction0<kotlin.Unit> origin=null reflectionTarget=<same>
+          FUN_EXPR type=kotlin.reflect.KFunction0<kotlin.Unit> origin=LAMBDA
+            FUN ADAPTER_FOR_CALLABLE_REFERENCE name:foo1 visibility:local modality:FINAL <> () returnType:kotlin.Unit
+              BLOCK_BODY
+                TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
+                  CALL 'public final fun foo1 (vararg xs: kotlin.Int): kotlin.Int declared in <root>' type=kotlin.Int origin=null

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -2003,6 +2003,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/callableReference/nested.kt");
         }
 
+        @TestMetadata("noReflectionForAdaptedCallableReferences.kt")
+        public void testNoReflectionForAdaptedCallableReferences() throws Exception {
+            runTest("compiler/testData/codegen/box/callableReference/noReflectionForAdaptedCallableReferences.kt");
+        }
+
         @TestMetadata("optimizedSuperclasses_after.kt")
         public void testOptimizedSuperclasses_after() throws Exception {
             runTest("compiler/testData/codegen/box/callableReference/optimizedSuperclasses_after.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -2003,6 +2003,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/callableReference/nested.kt");
         }
 
+        @TestMetadata("noReflectionForAdaptedCallableReferences.kt")
+        public void testNoReflectionForAdaptedCallableReferences() throws Exception {
+            runTest("compiler/testData/codegen/box/callableReference/noReflectionForAdaptedCallableReferences.kt");
+        }
+
         @TestMetadata("optimizedSuperclasses_after.kt")
         public void testOptimizedSuperclasses_after() throws Exception {
             runTest("compiler/testData/codegen/box/callableReference/optimizedSuperclasses_after.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -1983,6 +1983,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/callableReference/nested.kt");
         }
 
+        @TestMetadata("noReflectionForAdaptedCallableReferences.kt")
+        public void testNoReflectionForAdaptedCallableReferences() throws Exception {
+            runTest("compiler/testData/codegen/box/callableReference/noReflectionForAdaptedCallableReferences.kt");
+        }
+
         @TestMetadata("optimizedSuperclasses_after.kt")
         public void testOptimizedSuperclasses_after() throws Exception {
             runTest("compiler/testData/codegen/box/callableReference/optimizedSuperclasses_after.kt");

compiler/tests/org/jetbrains/kotlin/ir/IrTextTestCaseGenerated.java

@@ -1394,6 +1394,11 @@ public class IrTextTestCaseGenerated extends AbstractIrTextTestCase {
                 runTest("compiler/testData/ir/irText/expressions/callableReferences/adaptedExtensionFunctions.kt");
             }
 
+            @TestMetadata("adaptedWithCoercionToUnit.kt")
+            public void testAdaptedWithCoercionToUnit() throws Exception {
+                runTest("compiler/testData/ir/irText/expressions/callableReferences/adaptedWithCoercionToUnit.kt");
+            }
+
             public void testAllFilesPresentInCallableReferences() throws Exception {
                 KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/ir/irText/expressions/callableReferences"), Pattern.compile("^(.+)\\.kt$"), null, true);
             }