[JVM_IR] Box primitive types in class literals of reified type arguments

Bytecode inliner boxes primitive types in class literals of reified type
arguments. This is by design, and we should backport this behaviour to
IR inliner.

^KT-60144: Fixed

compiler/ir/backend.jvm/lower/src/org/jetbrains/kotlin/backend/jvm/JvmLower.kt

@@ -326,6 +326,16 @@ private val apiVersionIsAtLeastEvaluationPhase = makeIrModulePhase(
     prerequisite = setOf(functionInliningPhase)
 )
 
+private val inlinedClassReferencesBoxingPhase = makeIrModulePhase(
+    { context ->
+        if (!context.irInlinerIsEnabled()) return@makeIrModulePhase FileLoweringPass.Empty
+        InlinedClassReferencesBoxingLowering(context)
+    },
+    name = "InlinedClassReferencesBoxingLowering",
+    description = "Replace inlined primitive types in class references with boxed versions",
+    prerequisite = setOf(functionInliningPhase, markNecessaryInlinedClassesAsRegenerated)
+)
+
 private val constEvaluationPhase = makeIrModulePhase<JvmBackendContext>(
     ::ConstEvaluationLowering,
     name = "ConstEvaluationLowering",
@@ -476,6 +486,7 @@ private fun buildJvmLoweringPhases(
                 apiVersionIsAtLeastEvaluationPhase then
                 createSeparateCallForInlinedLambdas then
                 markNecessaryInlinedClassesAsRegenerated then
+                inlinedClassReferencesBoxingPhase then
 
                 buildLoweringsPhase(phases) then
                 generateMultifileFacadesPhase then

compiler/ir/backend.jvm/lower/src/org/jetbrains/kotlin/backend/jvm/lower/InlinedClassReferencesBoxingLowering.kt

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.backend.jvm.lower
+
+import org.jetbrains.kotlin.backend.common.FileLoweringPass
+import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
+import org.jetbrains.kotlin.backend.jvm.ir.getAttributeOwnerBeforeInline
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.declarations.IrFile
+import org.jetbrains.kotlin.ir.expressions.IrClassReference
+import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
+import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.types.impl.buildSimpleType
+import org.jetbrains.kotlin.ir.util.render
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
+import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
+
+internal class InlinedClassReferencesBoxingLowering(val context: JvmBackendContext) : FileLoweringPass, IrElementVisitorVoid {
+    override fun lower(irFile: IrFile) {
+        irFile.acceptChildrenVoid(this)
+    }
+
+    override fun visitElement(element: IrElement) {
+        element.acceptChildrenVoid(this)
+    }
+
+    override fun visitClassReference(expression: IrClassReference) {
+        super.visitClassReference(expression)
+
+        val wasTypeParameterClassRefBeforeInline =
+            (expression.getAttributeOwnerBeforeInline() as? IrClassReference)?.classType?.classifierOrNull is IrTypeParameterSymbol
+
+        if (wasTypeParameterClassRefBeforeInline && expression.classType.isPrimitiveType()) {
+            // Making primitive type nullable is effectively boxing
+            val boxedPrimitive = expression.classType.makeNullable()
+            require(boxedPrimitive is IrSimpleType) {
+                "Type is expected to be ${IrSimpleType::class.simpleName}: ${boxedPrimitive.render()}"
+            }
+            expression.classType = boxedPrimitive
+            val classReferenceType = expression.type
+            require(classReferenceType is IrSimpleType && classReferenceType.isKClass()) {
+                "Type of the type reference is expected to be KClass: ${classReferenceType.render()}"
+            }
+            expression.type = classReferenceType.buildSimpleType {
+                arguments = listOf(boxedPrimitive)
+            }
+        }
+    }
+
+}

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmSymbols.kt

@@ -937,14 +937,14 @@ class JvmSymbols(
             throw AssertionError("Array type expected: ${arrayType.render()}")
     }
 
-    private val javaLangInteger: IrClassSymbol = createJavaPrimitiveClass(FqName("java.lang.Integer"), irBuiltIns.intType)
+    val javaLangInteger: IrClassSymbol = createJavaPrimitiveClass(FqName("java.lang.Integer"), irBuiltIns.intType)
 
     val compareUnsignedInt: IrSimpleFunctionSymbol = javaLangInteger.functionByName("compareUnsigned")
     val divideUnsignedInt: IrSimpleFunctionSymbol = javaLangInteger.functionByName("divideUnsigned")
     val remainderUnsignedInt: IrSimpleFunctionSymbol = javaLangInteger.functionByName("remainderUnsigned")
     val toUnsignedStringInt: IrSimpleFunctionSymbol = javaLangInteger.functionByName("toUnsignedString")
 
-    private val javaLangLong: IrClassSymbol = createJavaPrimitiveClass(FqName("java.lang.Long"), irBuiltIns.longType)
+    val javaLangLong: IrClassSymbol = createJavaPrimitiveClass(FqName("java.lang.Long"), irBuiltIns.longType)
 
     val compareUnsignedLong: IrSimpleFunctionSymbol = javaLangLong.functionByName("compareUnsigned")
     val divideUnsignedLong: IrSimpleFunctionSymbol = javaLangLong.functionByName("divideUnsigned")

compiler/testData/codegen/box/classLiteral/java/javaReified.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 inline fun <reified T : Any> check(expected: String) {

compiler/testData/codegen/box/reflection/noReflectAtRuntime/reifiedTypeJavaClass.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/DIExample.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/anonymousObjectNoPropagate.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/defaultJavaClass.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/javaClass.kt

@@ -1,5 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
 
 // WITH_STDLIB
 

compiler/testData/codegen/box/reified/nestedReified.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/nonInlineableLambdaInReifiedFunction.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/recursiveNonInlineableLambda.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/reifiedInlineFunOfObject.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/reifiedInlineFunOfObjectWithinReified.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/reified/reifiedInlineIntoNonInlineableLambda.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_INLINER: IR
-
 // WITH_STDLIB
 
 import kotlin.test.assertEquals