IR: deal with conflicting variances in computeSubstitutedSyntheticAccessor

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

@@ -14387,6 +14387,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             public void testJavaNestedSamInterface() throws Exception {
                 runTest("compiler/testData/codegen/box/javaInterop/generics/javaNestedSamInterface.kt");
             }
+
+            @TestMetadata("propertyVarianceConflict.kt")
+            public void testPropertyVarianceConflict() throws Exception {
+                runTest("compiler/testData/codegen/box/javaInterop/generics/propertyVarianceConflict.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/javaInterop/notNullAssertions")

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

@@ -330,9 +330,13 @@ class AssignmentGenerator(statementGenerator: StatementGenerator) : StatementGen
                 ktExpression.startOffsetSkippingComments, ktExpression.endOffset, origin,
                 propertyIrType,
                 getterSymbol,
-                getterDescriptor?.let { computeSubstitutedSyntheticAccessor(unwrappedPropertyDescriptor, it) },
+                getterDescriptor?.let {
+                    computeSubstitutedSyntheticAccessor(unwrappedPropertyDescriptor, it, unwrappedPropertyDescriptor.getter!!)
+                },
                 setterSymbol,
-                setterDescriptor?.let { computeSubstitutedSyntheticAccessor(unwrappedPropertyDescriptor, it) },
+                setterDescriptor?.let {
+                    computeSubstitutedSyntheticAccessor(unwrappedPropertyDescriptor, it, unwrappedPropertyDescriptor.setter!!)
+                },
                 typeArgumentsList,
                 propertyReceiver,
                 superQualifierSymbol

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

@@ -211,7 +211,9 @@ class CallGenerator(statementGenerator: StatementGenerator) : StatementGenerator
                         IrStatementOrigin.GET_PROPERTY,
                         superQualifierSymbol
                     ).apply {
-                        context.callToSubstitutedDescriptorMap[this] = computeSubstitutedSyntheticAccessor(descriptor, getMethodDescriptor)
+                        context.callToSubstitutedDescriptorMap[this] = computeSubstitutedSyntheticAccessor(
+                            descriptor, getMethodDescriptor, descriptor.getter!!
+                        )
                         putTypeArguments(call.typeArguments) { it.toIrType() }
                         dispatchReceiver = dispatchReceiverValue?.load()
                         extensionReceiver = extensionReceiverValue?.load()

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/IrUtils.kt

@@ -17,12 +17,10 @@
 package org.jetbrains.kotlin.psi2ir.intermediate
 
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl
 import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
-import org.jetbrains.kotlin.ir.expressions.typeParametersCount
-import org.jetbrains.kotlin.types.TypeConstructor
-import org.jetbrains.kotlin.types.TypeSubstitutor
 
 fun IrVariable.defaultLoad(): IrExpression =
     IrGetValueImpl(startOffset, endOffset, type, symbol)
@@ -53,7 +51,11 @@ fun CallReceiver.adjustForCallee(callee: CallableMemberDescriptor): CallReceiver
     }
 
 
-fun computeSubstitutedSyntheticAccessor(propertyDescriptor: PropertyDescriptor, accessorFunctionDescriptor: FunctionDescriptor): FunctionDescriptor {
+fun computeSubstitutedSyntheticAccessor(
+    propertyDescriptor: PropertyDescriptor,
+    accessorFunctionDescriptor: FunctionDescriptor,
+    substitutedExtensionAccessorDescriptor: PropertyAccessorDescriptor
+): FunctionDescriptor {
     if (propertyDescriptor.original == propertyDescriptor) return accessorFunctionDescriptor
 
     // Compute substituted accessor descriptor in case of Synthetic Java property `Java: getFoo() -> Kotlin: foo`
@@ -65,38 +67,30 @@ fun computeSubstitutedSyntheticAccessor(propertyDescriptor: PropertyDescriptor,
 
     if (accessorFunctionDescriptor !is SimpleFunctionDescriptor) return accessorFunctionDescriptor
 
-    /**
-     * Consider java class like
-     * O.java
-     * class O<T1> {
-     *   class I<T2> {
-     *     public String getFoo() { ... }
-     *   }
-     * }
-     *
-     * k.kt
-     * fun f(i: O<String>.I<Int>) = i.foo
-     *
-     *
-     * for that case front end creates synthetic property foo
-     * private val <T1', T2'> O<T1'>.I<T2'>.foo get() = this.getFoo()
-     *
-     * So to get substituted descriptor for getFoo() we need to extract substitution from extension receiver type.
-     * To do so map Tx parameters onto Tx' arguments like
-     * T1' -> String
-     * T2' -> Int
-     * into
-     * T1 -> String
-     * T2 -> Int
-     */
+    return copyTypesFromExtensionAccessor(accessorFunctionDescriptor, substitutedExtensionAccessorDescriptor)
+}
 
-    val classDescriptor = accessorFunctionDescriptor.containingDeclaration as ClassDescriptor
-    val collectedTypeParameters = classDescriptor.typeConstructor.parameters.map { it.typeConstructor }
-    assert(collectedTypeParameters.size == propertyDescriptor.typeParametersCount)
-
-    val typeArguments = propertyDescriptor.extensionReceiverParameter!!.type.arguments
-    assert(typeArguments.size == collectedTypeParameters.size)
-
-    val typeSubstitutor = TypeSubstitutor.create(collectedTypeParameters.zip(typeArguments).toMap())
-    return accessorFunctionDescriptor.substitute(typeSubstitutor) ?: error("Cannot substitute descriptor for $accessorFunctionDescriptor")
-}
+// When computing substituted descriptor for a synthetic accessor of a synthesized property,
+// the property descriptor's accessor field almost has the right type,
+// except with extension receiver instead of dispatch receiver. Need to patch it up.
+private fun copyTypesFromExtensionAccessor(
+    accessorFunctionDescriptor: SimpleFunctionDescriptor,
+    extensionAccessorDescriptor: PropertyAccessorDescriptor
+): FunctionDescriptor =
+    SimpleFunctionDescriptorImpl.create(
+        accessorFunctionDescriptor.containingDeclaration,
+        accessorFunctionDescriptor.annotations,
+        accessorFunctionDescriptor.name,
+        accessorFunctionDescriptor.kind,
+        accessorFunctionDescriptor.source
+    ).apply {
+        initialize(
+            null,
+            extensionAccessorDescriptor.extensionReceiverParameter?.copy(this),
+            emptyList(),
+            extensionAccessorDescriptor.valueParameters.map { it.copy(this, it.name, it.index) },
+            extensionAccessorDescriptor.returnType,
+            accessorFunctionDescriptor.modality,
+            accessorFunctionDescriptor.visibility
+        )
+    }

compiler/testData/codegen/box/javaInterop/generics/propertyVarianceConflict.kt

@@ -0,0 +1,16 @@
+// TARGET_BACKEND: JVM
+
+// FILE: C.java
+
+class C<T> {
+    public C<? super T> getXx() { return this; }
+}
+
+// FILE: test.kt
+
+fun test() {
+    var c: C<out Any?> = C()
+    c = c.xx
+}
+
+fun box() = "OK"

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

@@ -15602,6 +15602,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             public void testJavaNestedSamInterface() throws Exception {
                 runTest("compiler/testData/codegen/box/javaInterop/generics/javaNestedSamInterface.kt");
             }
+
+            @TestMetadata("propertyVarianceConflict.kt")
+            public void testPropertyVarianceConflict() throws Exception {
+                runTest("compiler/testData/codegen/box/javaInterop/generics/propertyVarianceConflict.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/javaInterop/notNullAssertions")

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

@@ -15602,6 +15602,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             public void testJavaNestedSamInterface() throws Exception {
                 runTest("compiler/testData/codegen/box/javaInterop/generics/javaNestedSamInterface.kt");
             }
+
+            @TestMetadata("propertyVarianceConflict.kt")
+            public void testPropertyVarianceConflict() throws Exception {
+                runTest("compiler/testData/codegen/box/javaInterop/generics/propertyVarianceConflict.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/javaInterop/notNullAssertions")

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

@@ -14387,6 +14387,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             public void testJavaNestedSamInterface() throws Exception {
                 runTest("compiler/testData/codegen/box/javaInterop/generics/javaNestedSamInterface.kt");
             }
+
+            @TestMetadata("propertyVarianceConflict.kt")
+            public void testPropertyVarianceConflict() throws Exception {
+                runTest("compiler/testData/codegen/box/javaInterop/generics/propertyVarianceConflict.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/javaInterop/notNullAssertions")