Fixed bug in DefaultArgs lowering with vararg arguments + tests

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanPhases.kt

@@ -45,11 +45,11 @@ enum class KonanPhase(val description: String,
     /* ... ... */ LOWER_CALLABLES("Callable references Lowering", LOWER_DELEGATION),
     /* ... ... */ LOWER_LOCAL_FUNCTIONS("Local Function Lowering", LOWER_SHARED_VARIABLES, LOWER_CALLABLES),
     /* ... ... */ LOWER_INTEROP_PART2("Interop lowering, part 2", LOWER_LOCAL_FUNCTIONS),
-    /* ... ... */ LOWER_VARARG("Vararg lowering", LOWER_CALLABLES),
-    /* ... ... */ LOWER_COMPILE_TIME_EVAL("Compile time evaluation lowering", LOWER_VARARG),
     /* ... ... */ LOWER_TAILREC("tailrec lowering", LOWER_LOCAL_FUNCTIONS),
     /* ... ... */ LOWER_FINALLY("Finally blocks lowering", LOWER_INITIALIZERS, LOWER_LOCAL_FUNCTIONS, LOWER_TAILREC),
     /* ... ... */ LOWER_DEFAULT_PARAMETER_EXTENT("Default Parameter Extent Lowering", LOWER_TAILREC, LOWER_ENUMS),
+    /* ... ... */ LOWER_VARARG("Vararg lowering", LOWER_CALLABLES, LOWER_DEFAULT_PARAMETER_EXTENT),
+    /* ... ... */ LOWER_COMPILE_TIME_EVAL("Compile time evaluation lowering", LOWER_VARARG),
     /* ... ... */ LOWER_INNER_CLASSES("Inner classes lowering", LOWER_DEFAULT_PARAMETER_EXTENT),
     /* ... ... */ LOWER_BUILTIN_OPERATORS("BuiltIn Operators Lowering", LOWER_DEFAULT_PARAMETER_EXTENT),
     /* ... ... */ LOWER_COROUTINES("Coroutines lowering", LOWER_LOCAL_FUNCTIONS),

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/DefaultArgumentsStubGenerator.kt

@@ -45,9 +45,9 @@ import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
 import org.jetbrains.kotlin.resolve.calls.components.hasDefaultValue
+import org.jetbrains.kotlin.resolve.calls.components.isVararg
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.typeUtil.builtIns
 
@@ -311,8 +311,8 @@ class DefaultParameterInjector constructor(val context: CommonBackendContext): B
                         maskValues[maskIndex] = maskValues[maskIndex] or (1 shl (i % 32))
                     }
                     val valueParameterDescriptor = realDescriptor.valueParameters[i]
-                    val pair = valueParameterDescriptor to (valueArgument ?: nullConst(expression, valueParameterDescriptor.type))
-                    return@mapIndexed pair
+                    val defaultValueArgument = if (valueParameterDescriptor.isVararg) null else nullConst(expression, valueParameterDescriptor.type)
+                    valueParameterDescriptor to (valueArgument ?: defaultValueArgument)
                 })
                 maskValues.forEachIndexed { i, maskValue ->
                     params += maskParameterDescriptor(realFunction, i) to IrConstImpl.int(

backend.native/tests/build.gradle

@@ -362,6 +362,16 @@ task function_defaults_from_fake_override(type: RunKonanTest) {
     source = "codegen/function/defaultsFromFakeOverride.kt"
 }
 
+task function_defaults_with_vararg1(type: RunKonanTest) {
+    goldValue = "Hello , Correct!\nHello World, Correct!\n , Correct!\n"
+    source = "codegen/function/defaultsWithVarArg1.kt"
+}
+
+task function_defaults_with_vararg2(type: RunKonanTest) {
+    goldValue = "1\n2\n42\n"
+    source = "codegen/function/defaultsWithVarArg2.kt"
+}
+
 task sum_3const(type: RunKonanTest) {
     source = "codegen/function/sum_3const.kt"
 }

backend.native/tests/codegen/function/defaultsWithVarArg1.kt

@@ -0,0 +1,21 @@
+package codegen.function.defaultsWithVarArg1
+
+import kotlin.test.*
+
+fun foo(s: String = "", vararg args: Any) {
+    if (args == null) {
+        println("Failed!")
+    } else {
+        print("$s ")
+        args.forEach {
+            print("$it")
+        }
+        println(", Correct!")
+    }
+}
+
+@Test fun runTest() {
+    foo("Hello")
+    foo("Hello", "World")
+    foo()
+}

backend.native/tests/codegen/function/defaultsWithVarArg2.kt

@@ -0,0 +1,12 @@
+package codegen.function.defaultsWithVarArg2
+
+import kotlin.test.*
+
+fun foo(vararg arr: Int = intArrayOf(1, 2)) {
+    arr.forEach { println(it) }
+}
+
+@Test fun runTest() {
+    foo()
+    foo(42)
+}