Use upper bound aware type approximator for intersection types inside sam types in contravariant positions to build proper types in terms of subtyping

compiler/backend-common/src/org/jetbrains/kotlin/backend/common/SamType.kt

@@ -6,14 +6,17 @@
 package org.jetbrains.kotlin.backend.common
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
 import org.jetbrains.kotlin.resolve.sam.getAbstractMembers
 import org.jetbrains.kotlin.types.*
+import org.jetbrains.kotlin.types.checker.intersectWrappedTypes
+import org.jetbrains.kotlin.types.typeUtil.builtIns
 import org.jetbrains.kotlin.types.typeUtil.replaceArgumentsWithNothing
 
-class SamType constructor(val type: KotlinType) {
+class SamType constructor(val type: KotlinType, val hasUnapproximatableArguments: Boolean = false) {
 
     val classDescriptor: ClassDescriptor
         get() = type.constructor.declarationDescriptor as? ClassDescriptor ?: error("Sam/Fun interface not a class descriptor: $type")
@@ -38,7 +41,9 @@ class SamType constructor(val type: KotlinType) {
 }
 
 open class SamTypeFactory {
-    fun createByValueParameter(valueParameter: ValueParameterDescriptor): SamType? {
+    private lateinit var typeApproximator: TypeApproximator
+
+    fun createByValueParameter(valueParameter: ValueParameterDescriptor, languageVersionSettings: LanguageVersionSettings): SamType? {
         val singleArgumentType: KotlinType
         val originalSingleArgumentType: KotlinType?
         val varargElementType = valueParameter.varargElementType
@@ -56,6 +61,11 @@ open class SamTypeFactory {
         if (singleArgumentType.isError || originalSingleArgumentType!!.isError) {
             return null
         }
+
+        if (!::typeApproximator.isInitialized) {
+            typeApproximator = TypeApproximator(singleArgumentType.builtIns, languageVersionSettings)
+        }
+
         // This can be true in case when the value parameter is in the method of a generic type with out-projection.
         // We approximate Inv<Captured#1> to Nothing, while Inv itself can be a SAM interface safe to call here
         // (see testData genericSamProjectedOut.kt for details)
@@ -63,20 +73,41 @@ open class SamTypeFactory {
         // so we use Nothing arguments instead that leads to a raw type used for a SAM wrapper.
         // See org.jetbrains.kotlin.codegen.state.KotlinTypeMapper#writeGenericType to understand how
         // raw types and Nothing arguments relate.
-        val originalTypeToUse =
-            if (KotlinBuiltIns.isNothing(singleArgumentType))
-                originalSingleArgumentType.replaceArgumentsWithNothing()
-            else singleArgumentType
-        return create(originalTypeToUse.removeExternalProjections())
+        val originalTypeToUse = if (KotlinBuiltIns.isNothing(singleArgumentType))
+            originalSingleArgumentType.replaceArgumentsWithNothing()
+        else singleArgumentType
+        val approximatedOriginalTypeToUse = typeApproximator.approximateToSubType(
+            originalTypeToUse,
+            TypeApproximatorConfiguration.UpperBoundAwareIntersectionTypeApproximator
+        ) ?: originalTypeToUse
+        approximatedOriginalTypeToUse as KotlinType
+        val hasUnapproximatableArguments = hasUnapproximatableArguments(approximatedOriginalTypeToUse)
+
+        return create((approximatedOriginalTypeToUse).removeExternalProjections(), hasUnapproximatableArguments)
     }
 
+    /*
+     * declaration site: `class Foo<T> where T: X, T: Y {}`, X and Y aren't related by subtyping
+     * use site: Foo<in {X & Y}>
+     * => `in {X & Y}` is unapproximatable type argument
+     */
+    fun hasUnapproximatableArguments(type: KotlinType) =
+        type.arguments.isNotEmpty() && type.arguments.withIndex().any { (i, argument) ->
+            if (argument.projectionKind != Variance.IN_VARIANCE) return@any false
+            if (argument.type.constructor !is IntersectionTypeConstructor) return@any false
+            val typeParameter = type.constructor.parameters.getOrNull(i) ?: return@any false
+            // we have really intersection type as the result => at least there are two upper bounds which aren't related by subtyping
+            intersectWrappedTypes(typeParameter.upperBounds).constructor is IntersectionTypeConstructor
+        }
+
     open fun isSamType(type: KotlinType): Boolean {
         val descriptor = type.constructor.declarationDescriptor
         return descriptor is ClassDescriptor && descriptor.isFun
     }
 
-    fun create(originalType: KotlinType): SamType? {
-        return if (isSamType(originalType)) SamType(originalType) else null
+    @JvmOverloads
+    fun create(originalType: KotlinType, hasUnapproximatableArguments: Boolean = false): SamType? {
+        return if (isSamType(originalType)) SamType(originalType, hasUnapproximatableArguments) else null
     }
 
     private fun KotlinType.removeExternalProjections(): KotlinType {

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

@@ -862,7 +862,7 @@ class CodegenAnnotatingVisitor extends KtVisitorVoid {
         if (valueArguments == null) return;
 
         for (ValueParameterDescriptor valueParameter : valueParametersWithSAMConversion) {
-            SamType samType = JvmSamTypeFactory.INSTANCE.createByValueParameter(valueParameter);
+            SamType samType = JvmSamTypeFactory.INSTANCE.createByValueParameter(valueParameter, this.languageVersionSettings);
             if (samType == null) continue;
 
             ResolvedValueArgument resolvedValueArgument = valueArguments.get(valueParameter.getIndex());
@@ -874,7 +874,7 @@ class CodegenAnnotatingVisitor extends KtVisitorVoid {
     }
 
     private void recordSamTypeOnArgumentExpression(ValueParameterDescriptor valueParameter, ValueArgument valueArgument) {
-        SamType samType = JvmSamTypeFactory.INSTANCE.createByValueParameter(valueParameter);
+        SamType samType = JvmSamTypeFactory.INSTANCE.createByValueParameter(valueParameter, this.languageVersionSettings);
         if (samType == null) return;
 
         recordSamTypeOnArgumentExpression(samType, valueArgument);
@@ -973,7 +973,7 @@ class CodegenAnnotatingVisitor extends KtVisitorVoid {
         FunctionDescriptor original = SamCodegenUtil.getOriginalIfSamAdapter((FunctionDescriptor) operationDescriptor);
         if (original == null) return;
 
-        SamType samType = JvmSamTypeFactory.INSTANCE.createByValueParameter(original.getValueParameters().get(0));
+        SamType samType = JvmSamTypeFactory.INSTANCE.createByValueParameter(original.getValueParameters().get(0), this.languageVersionSettings);
         if (samType == null) return;
 
         IElementType token = expression.getOperationToken();
@@ -1002,7 +1002,7 @@ class CodegenAnnotatingVisitor extends KtVisitorVoid {
         List<KtExpression> indexExpressions = expression.getIndexExpressions();
         List<ValueParameterDescriptor> parameters = original.getValueParameters();
         for (ValueParameterDescriptor valueParameter : parameters) {
-            SamType samType = JvmSamTypeFactory.INSTANCE.createByValueParameter(valueParameter);
+            SamType samType = JvmSamTypeFactory.INSTANCE.createByValueParameter(valueParameter, this.languageVersionSettings);
             if (samType == null) continue;
 
             if (isSetter && valueParameter.getIndex() == parameters.size() - 1) {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -39182,6 +39182,40 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/sam/approximation")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Approximation {
+            @Test
+            public void testAllFilesPresentInApproximation() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sam/approximation"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+
+            @Test
+            @TestMetadata("approxToIntermediateType.kt")
+            public void testApproxToIntermediateType() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt");
+            }
+
+            @Test
+            @TestMetadata("approxToSingleUpperBound.kt")
+            public void testApproxToSingleUpperBound() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt");
+            }
+
+            @Test
+            @TestMetadata("impossibleToApproxToRepresentable.kt")
+            public void testImpossibleToApproxToRepresentable() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt");
+            }
+
+            @Test
+            @TestMetadata("impossibleToApproxToRepresentable2.kt")
+            public void testImpossibleToApproxToRepresentable2() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt");
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/testData/codegen/box/sam/constructors")
         @TestDataPath("$PROJECT_ROOT")

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/types/ConeTypeContext.kt

@@ -284,6 +284,11 @@ interface ConeTypeContext : TypeSystemContext, TypeSystemOptimizationContext, Ty
         return this.symbol.fir.bounds[index].coneType
     }
 
+    override fun TypeParameterMarker.getUpperBounds(): List<KotlinTypeMarker> {
+        require(this is ConeTypeParameterLookupTag)
+        return this.symbol.fir.bounds.map { it.coneType }
+    }
+
     override fun TypeParameterMarker.getTypeConstructor(): TypeConstructorMarker {
         require(this is ConeTypeParameterLookupTag)
         return this

compiler/ir/backend.jvm/entrypoint/src/org/jetbrains/kotlin/backend/jvm/JvmGeneratorExtensionsImpl.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.backend.jvm
 import org.jetbrains.kotlin.backend.common.ir.createImplicitParameterDeclarationWithWrappedDescriptor
 import org.jetbrains.kotlin.backend.common.ir.createParameterDeclarations
 import org.jetbrains.kotlin.codegen.JvmSamTypeFactory
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.FilteredAnnotations
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
@@ -59,8 +60,10 @@ open class JvmGeneratorExtensionsImpl(private val generateFacades: Boolean = tru
         override fun isPlatformSamType(type: KotlinType): Boolean =
             JavaSingleAbstractMethodUtils.isSamType(type)
 
-        override fun getSamTypeForValueParameter(valueParameter: ValueParameterDescriptor): KotlinType? =
-            JvmSamTypeFactory.createByValueParameter(valueParameter)?.type
+        override fun getSamTypeForValueParameter(
+            valueParameter: ValueParameterDescriptor,
+            languageVersionSettings: LanguageVersionSettings
+        ): KotlinType? = JvmSamTypeFactory.createByValueParameter(valueParameter, languageVersionSettings)?.type
 
         companion object Instance : JvmSamConversion()
     }

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

@@ -585,7 +585,7 @@ fun StatementGenerator.generateSamConversionForValueArgumentsIfRequired(call: Ca
             if (!originalValueParameters[i].type.isFunctionTypeOrSubtype) continue
         }
 
-        val samKotlinType = samConversion.getSamTypeForValueParameter(underlyingValueParameter)
+        val samKotlinType = samConversion.getSamTypeForValueParameter(underlyingValueParameter, context.languageVersionSettings)
             ?: underlyingValueParameter.varargElementType // If we have a vararg, vararg element type will be taken
             ?: underlyingValueParameter.type
 

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

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.psi.KtPureClassOrObject
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.backend.common.SamTypeFactory
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 
 open class GeneratorExtensions : StubGeneratorExtensions() {
     open val samConversion: SamConversion
@@ -24,8 +25,10 @@ open class GeneratorExtensions : StubGeneratorExtensions() {
     open class SamConversion {
         open fun isPlatformSamType(type: KotlinType): Boolean = false
 
-        open fun getSamTypeForValueParameter(valueParameter: ValueParameterDescriptor): KotlinType? =
-            SamTypeFactory.INSTANCE.createByValueParameter(valueParameter)?.type
+        open fun getSamTypeForValueParameter(
+            valueParameter: ValueParameterDescriptor,
+            languageVersionSettings: LanguageVersionSettings
+        ): KotlinType? = SamTypeFactory.INSTANCE.createByValueParameter(valueParameter, languageVersionSettings)?.type
 
         companion object Instance : SamConversion()
     }

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/IrTypeSystemContext.kt

@@ -176,6 +176,8 @@ interface IrTypeSystemContext : TypeSystemContext, TypeSystemCommonSuperTypesCon
 
     override fun TypeParameterMarker.getUpperBound(index: Int) = getSuperTypes(this)[index] as KotlinTypeMarker
 
+    override fun TypeParameterMarker.getUpperBounds() = getSuperTypes(this) as List<KotlinTypeMarker>
+
     override fun TypeParameterMarker.getTypeConstructor() = this as IrTypeParameterSymbol
 
     private fun KotlinTypeMarker.containsTypeConstructor(constructor: TypeConstructorMarker): Boolean {

compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt

@@ -0,0 +1,23 @@
+interface X
+interface Z
+
+interface W : X, Z
+
+interface A : W
+interface B : W
+
+fun interface IFoo<T> where T : X, T : Z {
+    fun accept(t: T)
+}
+
+fun <T> sel(x: T, y: T) = x
+
+class G<T> where T: X, T: Z {
+    fun check(x: IFoo<in T>) {}
+}
+
+fun box(): String {
+    val g = sel(G<A>(), G<B>()) // g: G<out { X & Z }>
+    g.check {} // target SAM type: IFoo<W>
+    return "OK"
+}

compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt

@@ -0,0 +1,21 @@
+interface X
+interface Z
+
+interface A : X, Z
+interface B : X, Z
+
+fun interface IFoo<T: X> {
+    fun accept(t: T)
+}
+
+fun <T> sel(x: T, y: T) = x
+
+class G<T: X> {
+    fun check(x: IFoo<in T>) {}
+}
+
+fun box(): String {
+    val g = sel(G<A>(), G<B>()) // g: G<out { X & Z }>
+    g.check {} // (*) target SAM type: IFoo<X>
+    return "OK"
+}

compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt

@@ -0,0 +1,21 @@
+interface X
+interface Z
+
+interface A : X, Z
+interface B : X, Z
+
+fun interface IFoo<T> where T : X, T : Z {
+    fun accept(t: T)
+}
+
+fun <T> sel(x: T, y: T) = x
+
+class G<T> where T: X, T: Z {
+    fun check(x: IFoo<in T>) {}
+}
+
+fun box(): String {
+    val g = sel(G<A>(), G<B>()) // g: G<out { X & Z }>
+    g.check {} // (*) target SAM type: IFoo<{ X & Z }> (TODO: report a compile time error for this case)
+    return "OK"
+}

compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt

@@ -0,0 +1,24 @@
+interface X: U, W
+interface Z: U, W
+
+interface U
+interface W
+
+interface A : X, Z
+interface B : X, Z
+
+fun interface IFoo<T> where T : U, T : W {
+    fun accept(t: T)
+}
+
+fun <T> sel(x: T, y: T) = x
+
+class G<T> where T: U, T: W {
+    fun check(x: IFoo<in T>) {}
+}
+
+fun box(): String {
+    val g = sel(G<A>(), G<B>())
+    g.check {} // TODO: report a compile time error for this case
+    return "OK"
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -39140,6 +39140,40 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/sam/approximation")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Approximation {
+            @Test
+            public void testAllFilesPresentInApproximation() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sam/approximation"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
+            }
+
+            @Test
+            @TestMetadata("approxToIntermediateType.kt")
+            public void testApproxToIntermediateType() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt");
+            }
+
+            @Test
+            @TestMetadata("approxToSingleUpperBound.kt")
+            public void testApproxToSingleUpperBound() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt");
+            }
+
+            @Test
+            @TestMetadata("impossibleToApproxToRepresentable.kt")
+            public void testImpossibleToApproxToRepresentable() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt");
+            }
+
+            @Test
+            @TestMetadata("impossibleToApproxToRepresentable2.kt")
+            public void testImpossibleToApproxToRepresentable2() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt");
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/testData/codegen/box/sam/constructors")
         @TestDataPath("$PROJECT_ROOT")

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -39182,6 +39182,40 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/sam/approximation")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Approximation {
+            @Test
+            public void testAllFilesPresentInApproximation() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sam/approximation"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+
+            @Test
+            @TestMetadata("approxToIntermediateType.kt")
+            public void testApproxToIntermediateType() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt");
+            }
+
+            @Test
+            @TestMetadata("approxToSingleUpperBound.kt")
+            public void testApproxToSingleUpperBound() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt");
+            }
+
+            @Test
+            @TestMetadata("impossibleToApproxToRepresentable.kt")
+            public void testImpossibleToApproxToRepresentable() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt");
+            }
+
+            @Test
+            @TestMetadata("impossibleToApproxToRepresentable2.kt")
+            public void testImpossibleToApproxToRepresentable2() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt");
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/testData/codegen/box/sam/constructors")
         @TestDataPath("$PROJECT_ROOT")

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

@@ -31285,6 +31285,39 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/box/sam/approximation")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Approximation extends AbstractLightAnalysisModeTest {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest(this::doTest, TargetBackend.JVM, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInApproximation() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sam/approximation"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
+            }
+
+            @TestMetadata("approxToIntermediateType.kt")
+            public void testApproxToIntermediateType() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt");
+            }
+
+            @TestMetadata("approxToSingleUpperBound.kt")
+            public void testApproxToSingleUpperBound() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable.kt")
+            public void testImpossibleToApproxToRepresentable() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable2.kt")
+            public void testImpossibleToApproxToRepresentable2() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt");
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/box/sam/constructors")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)

core/compiler.common/src/org/jetbrains/kotlin/types/model/TypeSystemContext.kt

@@ -325,6 +325,7 @@ interface TypeSystemContext : TypeSystemOptimizationContext {
     fun TypeParameterMarker.getVariance(): TypeVariance
     fun TypeParameterMarker.upperBoundCount(): Int
     fun TypeParameterMarker.getUpperBound(index: Int): KotlinTypeMarker
+    fun TypeParameterMarker.getUpperBounds(): List<KotlinTypeMarker>
     fun TypeParameterMarker.getTypeConstructor(): TypeConstructorMarker
     fun TypeParameterMarker.hasRecursiveBounds(selfConstructor: TypeConstructorMarker): Boolean
 

core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt

@@ -230,6 +230,11 @@ interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSy
         return this.upperBounds[index]
     }
 
+    override fun TypeParameterMarker.getUpperBounds(): List<KotlinTypeMarker> {
+        require(this is TypeParameterDescriptor, this::errorMessage)
+        return this.upperBounds
+    }
+
     override fun TypeParameterMarker.getTypeConstructor(): TypeConstructorMarker {
         require(this is TypeParameterDescriptor, this::errorMessage)
         return this.typeConstructor

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/es6/semantics/IrJsCodegenBoxES6TestGenerated.java

@@ -26285,6 +26285,39 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/box/sam/approximation")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Approximation extends AbstractIrJsCodegenBoxES6Test {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest0(this::doTest, TargetBackend.JS_IR_ES6, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInApproximation() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sam/approximation"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR_ES6, true);
+            }
+
+            @TestMetadata("approxToIntermediateType.kt")
+            public void testApproxToIntermediateType() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt");
+            }
+
+            @TestMetadata("approxToSingleUpperBound.kt")
+            public void testApproxToSingleUpperBound() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable.kt")
+            public void testImpossibleToApproxToRepresentable() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable2.kt")
+            public void testImpossibleToApproxToRepresentable2() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt");
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/box/sam/constructors")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -25691,6 +25691,39 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/box/sam/approximation")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Approximation extends AbstractIrJsCodegenBoxTest {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest0(this::doTest, TargetBackend.JS_IR, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInApproximation() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sam/approximation"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
+            }
+
+            @TestMetadata("approxToIntermediateType.kt")
+            public void testApproxToIntermediateType() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt");
+            }
+
+            @TestMetadata("approxToSingleUpperBound.kt")
+            public void testApproxToSingleUpperBound() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable.kt")
+            public void testImpossibleToApproxToRepresentable() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable2.kt")
+            public void testImpossibleToApproxToRepresentable2() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt");
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/box/sam/constructors")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -25651,6 +25651,39 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/box/sam/approximation")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Approximation extends AbstractJsCodegenBoxTest {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest0(this::doTest, TargetBackend.JS, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInApproximation() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sam/approximation"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS, true);
+            }
+
+            @TestMetadata("approxToIntermediateType.kt")
+            public void testApproxToIntermediateType() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt");
+            }
+
+            @TestMetadata("approxToSingleUpperBound.kt")
+            public void testApproxToSingleUpperBound() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable.kt")
+            public void testImpossibleToApproxToRepresentable() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable2.kt")
+            public void testImpossibleToApproxToRepresentable2() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt");
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/box/sam/constructors")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/wasm/semantics/IrCodegenBoxWasmTestGenerated.java

@@ -14022,6 +14022,39 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/box/sam/approximation")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Approximation extends AbstractIrCodegenBoxWasmTest {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest0(this::doTest, TargetBackend.WASM, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInApproximation() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/sam/approximation"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
+            }
+
+            @TestMetadata("approxToIntermediateType.kt")
+            public void testApproxToIntermediateType() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToIntermediateType.kt");
+            }
+
+            @TestMetadata("approxToSingleUpperBound.kt")
+            public void testApproxToSingleUpperBound() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/approxToSingleUpperBound.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable.kt")
+            public void testImpossibleToApproxToRepresentable() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable.kt");
+            }
+
+            @TestMetadata("impossibleToApproxToRepresentable2.kt")
+            public void testImpossibleToApproxToRepresentable2() throws Exception {
+                runTest("compiler/testData/codegen/box/sam/approximation/impossibleToApproxToRepresentable2.kt");
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/box/sam/constructors")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)