[IR] Fix copying of default argument from expect to actual with type parameter

^KT-45866 fixed

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

@@ -25182,6 +25182,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             public void testTypeAlias() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/typeAlias.kt");
             }
+
+            @Test
+            @TestMetadata("withTypeParameter.kt")
+            public void testWithTypeParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt");
+            }
         }
 
         @Nested

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/ExpectDeclarationRemover.kt

@@ -26,6 +26,8 @@ import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver
 // `doRemove` means should expect-declaration be removed from IR
 @OptIn(ObsoleteDescriptorBasedAPI::class)
 class ExpectDeclarationRemover(val symbolTable: ReferenceSymbolTable, private val doRemove: Boolean) : IrElementVisitorVoid {
+    private val typeParameterSubstitutionMap = mutableMapOf<Pair<IrFunction, IrFunction>, Map<IrTypeParameter, IrTypeParameter>>()
+
     override fun visitElement(element: IrElement) {
         element.acceptChildrenVoid(this)
     }
@@ -97,13 +99,29 @@ class ExpectDeclarationRemover(val symbolTable: ReferenceSymbolTable, private va
         // the `actual fun` or `actual constructor` for this may be in a different module.
         // Nothing we can do with those.
         // TODO they may not actually have the defaults though -- may be a frontend bug.
-        val expectParameter = function.findExpectForActual()?.valueParameters?.get(index) ?: return
+        val expectFunction = function.findExpectForActual()
+        val expectParameter = expectFunction?.valueParameters?.get(index) ?: return
 
         val defaultValue = expectParameter.defaultValue ?: return
 
+        val expectToActual = expectFunction to function
+        if (expectToActual !in typeParameterSubstitutionMap) {
+            val functionTypeParameters = collectTypeParameters(function)
+            val expectFunctionTypeParameters = collectTypeParameters(expectFunction)
+
+            expectFunctionTypeParameters.zip(functionTypeParameters).let { typeParametersMapping ->
+                typeParameterSubstitutionMap[expectToActual] = typeParametersMapping.toMap()
+            }
+        }
+
         defaultValue.let { originalDefault ->
             declaration.defaultValue = declaration.factory.createExpressionBody(originalDefault.startOffset, originalDefault.endOffset) {
-                expression = originalDefault.expression.deepCopyWithSymbols(function).remapExpectValueSymbols()
+                expression = originalDefault.expression
+                    .deepCopyWithSymbols(function)
+                    .remapExpectValueSymbols()
+                    .apply {
+                        remapTypes(IrTypeParameterRemapper(typeParameterSubstitutionMap.getValue(expectToActual)))
+                    }
             }
         }
     }

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InlineClassDeclarationLowering.kt

@@ -345,19 +345,6 @@ class InlineClassLowering(val context: CommonBackendContext) {
         }
     }
 
-    private fun collectTypeParameters(declaration: IrTypeParametersContainer): List<IrTypeParameter> {
-        val result = mutableListOf<IrTypeParameter>()
-
-        fun collectImpl(declaration: IrDeclaration) {
-            if (declaration is IrTypeParametersContainer) result.addAll(declaration.typeParameters)
-            if (declaration is IrClass && declaration.isInner) collectImpl(declaration.parent as IrDeclaration)
-        }
-
-        collectImpl(declaration)
-
-        return result
-    }
-
     private fun createStaticBodilessMethod(function: IrFunction): IrSimpleFunction =
         context.irFactory.createStaticFunctionWithReceivers(
             function.parent,

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -602,4 +602,20 @@ internal fun <T> IrConst<T>.shallowCopy() = IrConstImpl(
     type,
     kind,
     value
-)
+)
+
+fun collectTypeParameters(declaration: IrTypeParametersContainer): List<IrTypeParameter> {
+    val result = mutableListOf<IrTypeParameter>()
+
+    fun collectImpl(declaration: IrDeclaration) {
+        if (declaration is IrTypeParametersContainer) {
+            result.addAll(declaration.typeParameters)
+            declaration.parentClassOrNull?.let { collectImpl(it) }
+        }
+        if (declaration is IrClass && declaration.isInner) collectImpl(declaration.parent as IrDeclaration)
+    }
+
+    collectImpl(declaration)
+
+    return result
+}

compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt

@@ -0,0 +1,59 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: lib
+// FILE: common.kt
+
+expect fun <T> topLevel(a: T, b: (T) -> Int = { 1 }): String
+
+actual fun <T> topLevel(a: T, b: (T) -> Int): String = b(a).toString()
+
+expect class Foo() {
+    fun <T> member(a: T, b: (T) -> Int = { 2 }): String
+}
+
+actual class Foo actual constructor() {
+    actual fun <T> member(a: T, b: (T) -> Int): String = b(a).toString()
+}
+
+expect class Bar<T>() {
+    fun member(a: T, b: (T) -> Int = { 3 }): String
+}
+
+actual class Bar<T> actual constructor() {
+    actual fun member(a: T, b: (T) -> Int): String = b(a).toString()
+}
+
+expect class A<T> {
+    inner class B<N> {
+        fun <H> foo(t: T, n: N, h: H, a: (T, N, H) -> Int = { _, _, _ -> 4 }): String
+    }
+}
+
+actual class A<T> {
+    actual inner class B<N> {
+        actual fun <H> foo(t: T, n: N, h: H, a: (T, N, H) -> Int) = a(t, n, h).toString()
+    }
+}
+
+// MODULE: main(lib)
+// FILE: main.kt
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    assertEquals("1", topLevel("OK"))
+    assertEquals("73", topLevel("OK") { 73 })
+
+    val foo = Foo()
+    assertEquals("2", foo.member("OK"))
+    assertEquals("42", foo.member("OK") { 42 })
+
+    val bar = Bar<String>()
+    assertEquals("3", bar.member("OK"))
+    assertEquals("37", bar.member("OK") { 37 })
+
+    val b = A<Int>().B<Double>()
+    assertEquals("4", b.foo<Int>(1, 2.0, 3))
+    assertEquals("6", b.foo<Int>(1, 2.0, 3) { t, n, h -> t + n.toInt() + h })
+
+    return "OK"
+}

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

@@ -25164,6 +25164,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             public void testTypeAlias() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/typeAlias.kt");
             }
+
+            @Test
+            @TestMetadata("withTypeParameter.kt")
+            public void testWithTypeParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt");
+            }
         }
 
         @Nested

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

@@ -25182,6 +25182,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             public void testTypeAlias() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/typeAlias.kt");
             }
+
+            @Test
+            @TestMetadata("withTypeParameter.kt")
+            public void testWithTypeParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt");
+            }
         }
 
         @Nested

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

@@ -21301,6 +21301,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             public void testTypeAlias() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/typeAlias.kt");
             }
+
+            @TestMetadata("withTypeParameter.kt")
+            public void testWithTypeParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/multiplatform/exhaustiveness")

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

@@ -16745,6 +16745,11 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
             public void testTypeAlias() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/typeAlias.kt");
             }
+
+            @TestMetadata("withTypeParameter.kt")
+            public void testWithTypeParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/multiplatform/exhaustiveness")

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

@@ -16166,6 +16166,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             public void testTypeAlias() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/typeAlias.kt");
             }
+
+            @TestMetadata("withTypeParameter.kt")
+            public void testWithTypeParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/multiplatform/exhaustiveness")

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

@@ -16231,6 +16231,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             public void testTypeAlias() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/typeAlias.kt");
             }
+
+            @TestMetadata("withTypeParameter.kt")
+            public void testWithTypeParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/multiplatform/exhaustiveness")

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

@@ -9977,6 +9977,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             public void testTypeAlias() throws Exception {
                 runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/typeAlias.kt");
             }
+
+            @TestMetadata("withTypeParameter.kt")
+            public void testWithTypeParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/multiplatform/defaultArguments/withTypeParameter.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/multiplatform/exhaustiveness")