[NI] Don't use only platform specific checks for FIC in inference

compiler/frontend.java/src/org/jetbrains/kotlin/load/java/sam/JvmSamConversionTransformer.kt

@@ -8,12 +8,15 @@ package org.jetbrains.kotlin.load.java.sam
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.impl.TypeAliasConstructorDescriptor
 import org.jetbrains.kotlin.resolve.sam.SamConversionResolver
 import org.jetbrains.kotlin.load.java.descriptors.JavaClassConstructorDescriptor
+import org.jetbrains.kotlin.load.java.descriptors.JavaClassDescriptor
 import org.jetbrains.kotlin.resolve.calls.components.SamConversionTransformer
 import org.jetbrains.kotlin.synthetic.hasJavaOriginInHierarchy
+import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.UnwrappedType
 
 class JvmSamConversionTransformer(
@@ -33,4 +36,9 @@ class JvmSamConversionTransformer(
 
         return functionDescriptor.hasJavaOriginInHierarchy()
     }
+
+    override fun isPossibleSamType(samType: KotlinType): Boolean {
+        val descriptor = samType.constructor.declarationDescriptor
+        return descriptor is ClassDescriptor && (descriptor.isFun || descriptor is JavaClassDescriptor)
+    }
 }

compiler/frontend.java/src/org/jetbrains/kotlin/load/java/sam/SingleAbstractMethodUtils.java

@@ -38,6 +38,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
+import static org.jetbrains.kotlin.resolve.sam.SamConversionResolverImplKt.nonProjectionParametrization;
 import static org.jetbrains.kotlin.types.Variance.IN_VARIANCE;
 
 public class SingleAbstractMethodUtils {
@@ -73,7 +74,7 @@ public class SingleAbstractMethodUtils {
             SimpleType functionTypeDefault = samResolver.resolveFunctionTypeIfSamInterface(descriptor);
 
             if (functionTypeDefault != null) {
-                SimpleType noProjectionsSamType = SingleAbstractMethodUtilsKt.nonProjectionParametrization(samType);
+                SimpleType noProjectionsSamType = nonProjectionParametrization(samType);
                 if (noProjectionsSamType == null) return null;
 
                 // Function2<String, String, Int>?

compiler/frontend.java/src/org/jetbrains/kotlin/load/java/sam/SingleAbstractMethodUtils.kt

@@ -1,52 +0,0 @@
-/*
- * Copyright 2010-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.kotlin.load.java.sam
-
-import org.jetbrains.kotlin.types.SimpleType
-import org.jetbrains.kotlin.types.Variance
-import org.jetbrains.kotlin.types.replace
-import org.jetbrains.kotlin.types.typeUtil.asTypeProjection
-import org.jetbrains.kotlin.types.typeUtil.contains
-
-// If type 'samType' contains no projection, then it's non-projection parametrization is 'samType' itself
-// Else each projection type argument 'out/in A_i' (but star projections) is replaced with it's bound 'A_i'
-// Star projections are treated specially:
-// - If first upper bound of corresponding type parameter does not contain any type parameter of 'samType' class,
-//   then use this upper bound instead of star projection
-// - Otherwise no non-projection parametrization exists for such 'samType'
-//
-// See Non-wildcard parametrization in JLS 8 p.9.9 for clarification
-internal fun nonProjectionParametrization(samType: SimpleType): SimpleType? {
-    if (samType.arguments.none { it.projectionKind != Variance.INVARIANT }) return samType
-    val parameters = samType.constructor.parameters
-    val parametersSet = parameters.toSet()
-
-    return samType.replace(
-            newArguments = samType.arguments.zip(parameters).map {
-                val (projection, parameter) = it
-                when {
-                    projection.projectionKind == Variance.INVARIANT -> projection
-
-                    projection.isStarProjection ->
-                        parameter.upperBounds.first().takeUnless {
-                            t -> t.contains { it.constructor.declarationDescriptor in parametersSet }
-                        }?.asTypeProjection() ?: return@nonProjectionParametrization null
-
-                    else -> projection.type.asTypeProjection()
-                }
-            })
-}

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

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.container.DefaultImplementation
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
@@ -17,6 +18,7 @@ import org.jetbrains.kotlin.resolve.calls.inference.model.NewTypeVariable
 import org.jetbrains.kotlin.resolve.calls.model.*
 import org.jetbrains.kotlin.resolve.calls.results.SimpleConstraintSystem
 import org.jetbrains.kotlin.resolve.calls.tower.ImplicitScopeTower
+import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.StubType
 import org.jetbrains.kotlin.types.UnwrappedType
 
@@ -80,8 +82,14 @@ interface SamConversionTransformer {
 
     fun shouldRunSamConversionForFunction(candidate: CallableDescriptor): Boolean
 
+    fun isPossibleSamType(samType: KotlinType): Boolean
+
     object Empty : SamConversionTransformer {
         override fun getFunctionTypeForPossibleSamType(possibleSamType: UnwrappedType): UnwrappedType? = null
         override fun shouldRunSamConversionForFunction(candidate: CallableDescriptor): Boolean = false
+        override fun isPossibleSamType(samType: KotlinType): Boolean {
+            val descriptor = samType.constructor.declarationDescriptor
+            return descriptor is ClassDescriptor && descriptor.isFun
+        }
     }
 }

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

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind.*
 import org.jetbrains.kotlin.resolve.calls.tower.InfixCallNoInfixModifier
 import org.jetbrains.kotlin.resolve.calls.tower.InvokeConventionCallNoOperatorModifier
 import org.jetbrains.kotlin.resolve.calls.tower.VisibilityError
+import org.jetbrains.kotlin.resolve.sam.getFunctionTypeForPossibleSamType
 import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.typeUtil.contains
 import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
@@ -311,7 +312,9 @@ private fun KotlinResolutionCandidate.getExpectedTypeWithSAMConversion(
                 !callComponents.languageVersionSettings.supportsFeature(LanguageFeature.ProhibitVarargAsArrayAfterSamArgument)
 
     if (generatingAdditionalSamCandidateIsEnabled) return null
-    if (!callComponents.samConversionTransformer.shouldRunSamConversionForFunction(resolvedCall.candidateDescriptor)) return null
+    if (!callComponents.languageVersionSettings.supportsFeature(LanguageFeature.SamConversionForKotlinFunctions)) {
+        if (!callComponents.samConversionTransformer.shouldRunSamConversionForFunction(resolvedCall.candidateDescriptor)) return null
+    }
 
     val argumentIsFunctional = when (argument) {
         is SimpleKotlinCallArgument -> argument.receiver.stableType.isFunctionType
@@ -321,11 +324,14 @@ private fun KotlinResolutionCandidate.getExpectedTypeWithSAMConversion(
     if (!argumentIsFunctional) return null
 
     val originalExpectedType = argument.getExpectedType(candidateParameter.original, callComponents.languageVersionSettings)
+
+    if (!callComponents.samConversionTransformer.isPossibleSamType(originalExpectedType)) return null
+
     val convertedTypeByOriginal =
-        callComponents.samConversionTransformer.getFunctionTypeForPossibleSamType(originalExpectedType) ?: return null
+        callComponents.samConversionResolver.getFunctionTypeForPossibleSamType(originalExpectedType) ?: return null
 
     val candidateExpectedType = argument.getExpectedType(candidateParameter, callComponents.languageVersionSettings)
-    val convertedTypeByCandidate = callComponents.samConversionTransformer.getFunctionTypeForPossibleSamType(candidateExpectedType)
+    val convertedTypeByCandidate = callComponents.samConversionResolver.getFunctionTypeForPossibleSamType(candidateExpectedType)
 
     assert(candidateExpectedType.constructor == originalExpectedType.constructor && convertedTypeByCandidate != null) {
         "If original type is SAM type, then candidate should have same type constructor and corresponding function type\n" +

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/model/KotlinResolverContext.kt

@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.resolve.calls.inference.model.ConstraintStorage
 import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind
 import org.jetbrains.kotlin.resolve.calls.tower.*
 import org.jetbrains.kotlin.resolve.descriptorUtil.hasDynamicExtensionAnnotation
+import org.jetbrains.kotlin.resolve.sam.SamConversionResolver
 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValueWithSmartCastInfo
 import org.jetbrains.kotlin.types.ErrorUtils
 import org.jetbrains.kotlin.types.TypeSubstitutor
@@ -44,6 +45,7 @@ class KotlinCallComponents(
     val builtIns: KotlinBuiltIns,
     val languageVersionSettings: LanguageVersionSettings,
     val samConversionTransformer: SamConversionTransformer,
+    val samConversionResolver: SamConversionResolver,
     val kotlinTypeChecker: NewKotlinTypeChecker
 )
 

compiler/testData/multiplatform/funInterfaces/common.kt

@@ -0,0 +1,15 @@
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+NewInference
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+SamConversionForKotlinFunctions
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+SamConversionPerArgument
+
+package common
+
+fun interface KRunnable {
+    fun invoke(): String
+}
+
+fun foo(k: KRunnable) = k.invoke()
+
+fun test() {
+    foo { "OK" }
+}

compiler/testData/multiplatform/funInterfaces/js.kt

@@ -0,0 +1,15 @@
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+NewInference
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+SamConversionForKotlinFunctions
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+SamConversionPerArgument
+
+package js
+
+fun interface KRunnable {
+    fun invoke(): String
+}
+
+fun foo(k: KRunnable) = k.invoke()
+
+fun test() {
+    foo { "OK" }
+}

compiler/testData/multiplatform/funInterfaces/jvm.kt

@@ -0,0 +1,15 @@
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+NewInference
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+SamConversionForKotlinFunctions
+// ADDITIONAL_COMPILER_ARGUMENTS: -XXLanguage:+SamConversionPerArgument
+
+package jvm
+
+fun interface KRunnable {
+    fun invoke(): String
+}
+
+fun foo(k: KRunnable) = k.invoke()
+
+fun test() {
+    foo { "OK" }
+}

compiler/testData/multiplatform/funInterfaces/output.txt

@@ -0,0 +1,41 @@
+-- Common --
+Exit code: OK
+Output:
+warning: ATTENTION!
+This build uses unsafe internal compiler arguments:
+
+-XXLanguage:+NewInference
+-XXLanguage:+SamConversionForKotlinFunctions
+-XXLanguage:+SamConversionPerArgument
+
+This mode is not recommended for production use,
+as no stability/compatibility guarantees are given on
+compiler or generated code. Use it at your own risk!
+
+-- JVM --
+Exit code: OK
+Output:
+warning: ATTENTION!
+This build uses unsafe internal compiler arguments:
+
+-XXLanguage:+NewInference
+-XXLanguage:+SamConversionForKotlinFunctions
+-XXLanguage:+SamConversionPerArgument
+
+This mode is not recommended for production use,
+as no stability/compatibility guarantees are given on
+compiler or generated code. Use it at your own risk!
+
+-- JS --
+Exit code: OK
+Output:
+warning: ATTENTION!
+This build uses unsafe internal compiler arguments:
+
+-XXLanguage:+NewInference
+-XXLanguage:+SamConversionForKotlinFunctions
+-XXLanguage:+SamConversionPerArgument
+
+This mode is not recommended for production use,
+as no stability/compatibility guarantees are given on
+compiler or generated code. Use it at your own risk!

compiler/tests/org/jetbrains/kotlin/multiplatform/MultiPlatformIntegrationTestGenerated.java

@@ -53,6 +53,11 @@ public class MultiPlatformIntegrationTestGenerated extends AbstractMultiPlatform
         runTest("compiler/testData/multiplatform/explicitActualOnOverrideOfAbstractMethod/");
     }
 
+    @TestMetadata("funInterfaces")
+    public void testFunInterfaces() throws Exception {
+        runTest("compiler/testData/multiplatform/funInterfaces/");
+    }
+
     @TestMetadata("genericDeclarations")
     public void testGenericDeclarations() throws Exception {
         runTest("compiler/testData/multiplatform/genericDeclarations/");
@@ -409,6 +414,19 @@ public class MultiPlatformIntegrationTestGenerated extends AbstractMultiPlatform
         }
     }
 
+    @TestMetadata("compiler/testData/multiplatform/funInterfaces")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class FunInterfaces extends AbstractMultiPlatformIntegrationTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInFunInterfaces() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/multiplatform/funInterfaces"), Pattern.compile("^([^\\.]+)$"), null, true);
+        }
+    }
+
     @TestMetadata("compiler/testData/multiplatform/genericDeclarations")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

core/descriptors/src/org/jetbrains/kotlin/resolve/sam/SamConversionResolver.kt

@@ -10,7 +10,7 @@ import org.jetbrains.kotlin.container.PlatformSpecificExtension
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.types.SimpleType
 
-@DefaultImplementation(impl = SamConversionResolver.Empty::class)
+@DefaultImplementation(impl = SamConversionResolverImpl.SamConversionResolverWithoutReceiverConversion::class)
 interface SamConversionResolver : PlatformSpecificExtension<SamConversionResolver> {
     object Empty : SamConversionResolver {
         override fun resolveFunctionTypeIfSamInterface(classDescriptor: ClassDescriptor): SimpleType? = null

core/descriptors/src/org/jetbrains/kotlin/resolve/sam/SamConversionResolverImpl.kt

@@ -11,19 +11,26 @@ import org.jetbrains.kotlin.descriptors.annotations.Annotations.Companion.EMPTY
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.name.SpecialNames
 import org.jetbrains.kotlin.resolve.DescriptorUtils
-import org.jetbrains.kotlin.resolve.sam.SamConversionResolver
 import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
-import org.jetbrains.kotlin.resolve.sam.SamWithReceiverResolver
 import org.jetbrains.kotlin.storage.StorageManager
-import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.*
-import org.jetbrains.kotlin.types.SimpleType
+import org.jetbrains.kotlin.types.typeUtil.asTypeProjection
+import org.jetbrains.kotlin.types.typeUtil.contains
 import java.util.*
 
 class SamConversionResolverImpl(
-        storageManager: StorageManager,
+    storageManager: StorageManager,
-        private val samWithReceiverResolvers: Iterable<SamWithReceiverResolver>
+    private val samWithReceiverResolvers: Iterable<SamWithReceiverResolver>
-): SamConversionResolver {
+) : SamConversionResolver {
+    class SamConversionResolverWithoutReceiverConversion(storageManager: StorageManager) : SamConversionResolver {
+        val resolver = SamConversionResolverImpl(storageManager, emptyList())
+
+        override fun resolveFunctionTypeIfSamInterface(classDescriptor: ClassDescriptor): SimpleType? {
+            return resolver.resolveFunctionTypeIfSamInterface(classDescriptor)
+        }
+    }
+
     private val functionTypesForSamInterfaces = storageManager.createCacheWithNullableValues<ClassDescriptor, SimpleType>()
 
     override fun resolveFunctionTypeIfSamInterface(classDescriptor: ClassDescriptor): SimpleType? {
@@ -86,4 +93,71 @@ fun getFunctionTypeForAbstractMethod(
         function.builtIns, EMPTY, receiverType, parameterTypes,
         parameterNames, returnType, function.isSuspend
     )
-}
+}
+
+fun SamConversionResolver.getFunctionTypeForPossibleSamType(possibleSamType: UnwrappedType): UnwrappedType? =
+    getFunctionTypeForSamType(possibleSamType, this)?.unwrap()
+
+fun getFunctionTypeForSamType(samType: KotlinType, samResolver: SamConversionResolver): KotlinType? {
+    val unwrappedType = samType.unwrap()
+    if (unwrappedType is FlexibleType) {
+        val lower = getFunctionTypeForSamType(unwrappedType.lowerBound, samResolver)
+        val upper = getFunctionTypeForSamType(unwrappedType.upperBound, samResolver)
+
+        assert((lower == null) == (upper == null)) { "Illegal flexible type: $unwrappedType" }
+
+        if (lower == null || upper == null) return null
+
+        return KotlinTypeFactory.flexibleType(lower, upper)
+    } else {
+        return getFunctionTypeForSamType(unwrappedType as SimpleType, samResolver)
+    }
+}
+
+private fun getFunctionTypeForSamType(samType: SimpleType, samResolver: SamConversionResolver): SimpleType? {
+    // e.g. samType == Comparator<String>?
+    val classifier = samType.constructor.declarationDescriptor
+    if (classifier !is ClassDescriptor) return null
+
+    // Function2<T, T, Int>
+    val functionTypeDefault = samResolver.resolveFunctionTypeIfSamInterface(classifier) ?: return null
+    val noProjectionsSamType = nonProjectionParametrization(samType) ?: return null
+
+    // Function2<String, String, Int>?
+    val type = TypeSubstitutor.create(noProjectionsSamType).substitute(functionTypeDefault, Variance.IN_VARIANCE)
+    assert(type != null) {
+        "Substitution based on type with no projections '$noProjectionsSamType' should not end with conflict"
+    }
+
+    val simpleType = type!!.asSimpleType()
+    return simpleType.makeNullableAsSpecified(samType.isMarkedNullable)
+}
+
+// If type 'samType' contains no projection, then it's non-projection parametrization is 'samType' itself
+// Else each projection type argument 'out/in A_i' (but star projections) is replaced with it's bound 'A_i'
+// Star projections are treated specially:
+// - If first upper bound of corresponding type parameter does not contain any type parameter of 'samType' class,
+//   then use this upper bound instead of star projection
+// - Otherwise no non-projection parametrization exists for such 'samType'
+//
+// See Non-wildcard parametrization in JLS 8 p.9.9 for clarification
+fun nonProjectionParametrization(samType: SimpleType): SimpleType? {
+    if (samType.arguments.none { it.projectionKind != Variance.INVARIANT }) return samType
+    val parameters = samType.constructor.parameters
+    val parametersSet = parameters.toSet()
+
+    return samType.replace(
+        newArguments = samType.arguments.zip(parameters).map {
+            val (projection, parameter) = it
+            when {
+                projection.projectionKind == Variance.INVARIANT -> projection
+
+                projection.isStarProjection ->
+                    parameter.upperBounds.first().takeUnless { t ->
+                        t.contains { it.constructor.declarationDescriptor in parametersSet }
+                    }?.asTypeProjection() ?: return@nonProjectionParametrization null
+
+                else -> projection.type.asTypeProjection()
+            }
+        })
+}

idea/idea-core/src/org/jetbrains/kotlin/idea/core/psiModificationUtils.kt

@@ -37,6 +37,8 @@ import org.jetbrains.kotlin.resolve.calls.callUtil.getValueArgumentsInParenthese
 import org.jetbrains.kotlin.resolve.calls.components.SamConversionTransformer
 import org.jetbrains.kotlin.resolve.calls.model.ArgumentMatch
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.resolve.sam.SamConversionResolver
+import org.jetbrains.kotlin.resolve.sam.getFunctionTypeForPossibleSamType
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.isError
 import org.jetbrains.kotlin.types.typeUtil.isTypeParameter
@@ -127,7 +129,7 @@ fun KtCallExpression.canMoveLambdaOutsideParentheses(): Boolean {
         val referenceArgumentCount = valueArguments.count { it.getArgumentExpression() is KtCallableReferenceExpression }
 
         val resolutionFacade = getResolutionFacade()
-        val samConversionTransformer = resolutionFacade.frontendService<SamConversionTransformer>()
+        val samConversionTransformer = resolutionFacade.frontendService<SamConversionResolver>()
         val languageVersionSettings = resolutionFacade.frontendService<LanguageVersionSettings>()
 
         val bindingContext = analyze(resolutionFacade, BodyResolveMode.PARTIAL)
@@ -154,7 +156,7 @@ fun KtCallExpression.canMoveLambdaOutsideParentheses(): Boolean {
 
 private fun FunctionDescriptor.allowsMoveOfLastParameterOutsideParentheses(
     lambdaAndCallableReferencesInOriginalCallCount: Int,
-    samConversionTransformer: SamConversionTransformer,
+    samConversionTransformer: SamConversionResolver,
     newInferenceEnabled: Boolean
 ): Boolean {
     fun KotlinType.allowsMoveOutsideParentheses(): Boolean {