KT-36972 Don't create proxies for companion @JvmStatic $default in host

When creating proxy functions in a host class for @JvmStatic members of
companion object, skip functions for default parameters handling.

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

@@ -8272,6 +8272,16 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/defaultArguments/inheritedFromInterfaceViaAbstractSuperclass.kt");
         }
 
+        @TestMetadata("kt36972_companion.kt")
+        public void testKt36972_companion() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36972_companion.kt");
+        }
+
+        @TestMetadata("kt36972_object.kt")
+        public void testKt36972_object() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36972_object.kt");
+        }
+
         @TestMetadata("kt6382.kt")
         public void testKt6382() throws Exception {
             runTest("compiler/testData/codegen/box/defaultArguments/kt6382.kt");

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

@@ -59,29 +59,33 @@ private class CompanionObjectJvmStaticLowering(val context: JvmBackendContext) :
     override fun lower(irClass: IrClass) {
         val companion = irClass.declarations.find {
             it is IrClass && it.isCompanion
-        } as IrClass?
+        } as? IrClass ?: return
 
-        companion?.declarations?.filter(::isJvmStaticFunction)?.forEach { declaration ->
+        companion.declarations
-            val jvmStaticFunction = declaration as IrSimpleFunction
+            // In case of companion objects, proxy functions for '$default' methods for @JvmStatic functions with default parameters
-            if (jvmStaticFunction.isExternal) {
+            // are not created in the host class.
-                // We move external functions to the enclosing class and potentially add accessors there.
+            .filter { isJvmStaticFunction(it) && it.origin != IrDeclarationOrigin.FUNCTION_FOR_DEFAULT_PARAMETER }
-                // The JVM backend also adds accessors in the companion object, but these are superfluous.
+            .forEach { declaration ->
-                val staticExternal = irClass.addFunction {
+                val jvmStaticFunction = declaration as IrSimpleFunction
-                    updateFrom(jvmStaticFunction)
+                if (jvmStaticFunction.isExternal) {
-                    name = jvmStaticFunction.name
+                    // We move external functions to the enclosing class and potentially add accessors there.
-                    returnType = jvmStaticFunction.returnType
+                    // The JVM backend also adds accessors in the companion object, but these are superfluous.
-                }.apply {
+                    val staticExternal = irClass.addFunction {
-                    copyTypeParametersFrom(jvmStaticFunction)
+                        updateFrom(jvmStaticFunction)
-                    extensionReceiverParameter = jvmStaticFunction.extensionReceiverParameter?.copyTo(this)
+                        name = jvmStaticFunction.name
-                    valueParameters = jvmStaticFunction.valueParameters.map { it.copyTo(this) }
+                        returnType = jvmStaticFunction.returnType
-                    annotations = jvmStaticFunction.annotations.map { it.deepCopyWithSymbols() }
+                    }.apply {
+                        copyTypeParametersFrom(jvmStaticFunction)
+                        extensionReceiverParameter = jvmStaticFunction.extensionReceiverParameter?.copyTo(this)
+                        valueParameters = jvmStaticFunction.valueParameters.map { it.copyTo(this) }
+                        annotations = jvmStaticFunction.annotations.map { it.deepCopyWithSymbols() }
+                    }
+                    companion.declarations.remove(jvmStaticFunction)
+                    companion.addProxy(staticExternal, companion, isStatic = false)
+                } else {
+                    irClass.addProxy(jvmStaticFunction, companion)
                 }
-                companion.declarations.remove(jvmStaticFunction)
-                companion.addProxy(staticExternal, companion, isStatic = false)
-            } else {
-                irClass.addProxy(jvmStaticFunction, companion)
             }
-        }
     }
 
     private fun IrClass.addProxy(target: IrSimpleFunction, companion: IrClass, isStatic: Boolean = true) =

compiler/testData/codegen/box/defaultArguments/kt36972_companion.kt

@@ -0,0 +1,11 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+class Host {
+    companion object {
+        @JvmStatic
+        fun foo(s: String = "OK") = s
+    }
+}
+
+fun box(): String = Host.foo()

compiler/testData/codegen/box/defaultArguments/kt36972_object.kt

@@ -0,0 +1,9 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+object Host {
+    @JvmStatic
+    fun foo(s: String = "OK") = s
+}
+
+fun box(): String = Host.foo()

compiler/testData/codegen/bytecodeListing/jvmStaticWithDefaultParameters.kt

@@ -0,0 +1,13 @@
+// WITH_RUNTIME
+
+class WithCompanion {
+    companion object {
+        @JvmStatic
+        fun foo(x: Int = 1) {}
+    }
+}
+
+object AnObject {
+    @JvmStatic
+    fun foo(x: Int = 1) {}
+}

compiler/testData/codegen/bytecodeListing/jvmStaticWithDefaultParameters.txt

@@ -0,0 +1,26 @@
+@kotlin.Metadata
+public final class AnObject {
+    public final static field INSTANCE: AnObject
+    static method <clinit>(): void
+    private method <init>(): void
+    public synthetic static method foo$default(p0: int, p1: int, p2: java.lang.Object): void
+    public final static @kotlin.jvm.JvmStatic method foo(p0: int): void
+}
+
+@kotlin.Metadata
+public final class WithCompanion$Companion {
+    inner class WithCompanion$Companion
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+    public synthetic static method foo$default(p0: WithCompanion$Companion, p1: int, p2: int, p3: java.lang.Object): void
+    public final @kotlin.jvm.JvmStatic method foo(p0: int): void
+}
+
+@kotlin.Metadata
+public final class WithCompanion {
+    public final static field Companion: WithCompanion$Companion
+    inner class WithCompanion$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+    public final static @kotlin.jvm.JvmStatic method foo(p0: int): void
+}

compiler/testData/codegen/bytecodeListing/jvmStaticWithDefaultParameters_ir.txt

@@ -0,0 +1,26 @@
+@kotlin.Metadata
+public final class AnObject {
+    public final static @org.jetbrains.annotations.NotNull field INSTANCE: AnObject
+    static method <clinit>(): void
+    private method <init>(): void
+    public synthetic static method foo$default(p0: int, p1: int, p2: java.lang.Object): void
+    public final static @kotlin.jvm.JvmStatic method foo(p0: int): void
+}
+
+@kotlin.Metadata
+public final class WithCompanion$Companion {
+    inner class WithCompanion$Companion
+    private method <init>(): void
+    public synthetic method <init>(@org.jetbrains.annotations.NotNull p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+    public synthetic static method foo$default(p0: WithCompanion$Companion, p1: int, p2: int, p3: java.lang.Object): void
+    public final @kotlin.jvm.JvmStatic method foo(p0: int): void
+}
+
+@kotlin.Metadata
+public final class WithCompanion {
+    public final static @org.jetbrains.annotations.NotNull field Companion: WithCompanion$Companion
+    inner class WithCompanion$Companion
+    static method <clinit>(): void
+    public method <init>(): void
+    public final static @kotlin.jvm.JvmStatic method foo(p0: int): void
+}

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

@@ -9417,6 +9417,16 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/defaultArguments/inheritedFromInterfaceViaAbstractSuperclass.kt");
         }
 
+        @TestMetadata("kt36972_companion.kt")
+        public void testKt36972_companion() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36972_companion.kt");
+        }
+
+        @TestMetadata("kt36972_object.kt")
+        public void testKt36972_object() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36972_object.kt");
+        }
+
         @TestMetadata("kt6382.kt")
         public void testKt6382() throws Exception {
             runTest("compiler/testData/codegen/box/defaultArguments/kt6382.kt");

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

@@ -69,6 +69,11 @@ public class BytecodeListingTestGenerated extends AbstractBytecodeListingTest {
         runTest("compiler/testData/codegen/bytecodeListing/jvmOverloadsAndParametersAnnotations.kt");
     }
 
+    @TestMetadata("jvmStaticWithDefaultParameters.kt")
+    public void testJvmStaticWithDefaultParameters() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/jvmStaticWithDefaultParameters.kt");
+    }
+
     @TestMetadata("noCollectionStubMethodsInInterface.kt")
     public void testNoCollectionStubMethodsInInterface() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/noCollectionStubMethodsInInterface.kt");

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

@@ -9417,6 +9417,16 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/defaultArguments/inheritedFromInterfaceViaAbstractSuperclass.kt");
         }
 
+        @TestMetadata("kt36972_companion.kt")
+        public void testKt36972_companion() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36972_companion.kt");
+        }
+
+        @TestMetadata("kt36972_object.kt")
+        public void testKt36972_object() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36972_object.kt");
+        }
+
         @TestMetadata("kt6382.kt")
         public void testKt6382() throws Exception {
             runTest("compiler/testData/codegen/box/defaultArguments/kt6382.kt");

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

@@ -8272,6 +8272,16 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/defaultArguments/inheritedFromInterfaceViaAbstractSuperclass.kt");
         }
 
+        @TestMetadata("kt36972_companion.kt")
+        public void testKt36972_companion() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36972_companion.kt");
+        }
+
+        @TestMetadata("kt36972_object.kt")
+        public void testKt36972_object() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36972_object.kt");
+        }
+
         @TestMetadata("kt6382.kt")
         public void testKt6382() throws Exception {
             runTest("compiler/testData/codegen/box/defaultArguments/kt6382.kt");

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

@@ -69,6 +69,11 @@ public class IrBytecodeListingTestGenerated extends AbstractIrBytecodeListingTes
         runTest("compiler/testData/codegen/bytecodeListing/jvmOverloadsAndParametersAnnotations.kt");
     }
 
+    @TestMetadata("jvmStaticWithDefaultParameters.kt")
+    public void testJvmStaticWithDefaultParameters() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/jvmStaticWithDefaultParameters.kt");
+    }
+
     @TestMetadata("noCollectionStubMethodsInInterface.kt")
     public void testNoCollectionStubMethodsInInterface() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/noCollectionStubMethodsInInterface.kt");