Allow to declare vararg parameters of unsigned types

varargs inside annotations will be supported later when
 constant evaluation of more complex expressions of unsigned types
 will be ready

 #KT-24880 In Progress

compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationsChecker.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.resolve
 import com.google.common.collect.ImmutableSet
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.builtins.UnsignedTypes
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.*
@@ -921,7 +922,9 @@ class DeclarationsChecker(
         val nullableNothing = callableDescriptor.builtIns.nullableNothingType
         for (parameter in varargParameters) {
             val varargElementType = parameter.varargElementType!!.upperIfFlexible()
-            if (KotlinTypeChecker.DEFAULT.isSubtypeOf(varargElementType, nullableNothing) || varargElementType.isInlineClassType()) {
+            if (KotlinTypeChecker.DEFAULT.isSubtypeOf(varargElementType, nullableNothing) ||
+                (varargElementType.isInlineClassType() && !UnsignedTypes.isUnsignedType(varargElementType))
+            ) {
                 val parameterDeclaration = DescriptorToSourceUtils.descriptorToDeclaration(parameter) as? KtParameter ?: continue
                 trace.report(FORBIDDEN_VARARG_PARAMETER_TYPE.on(parameterDeclaration, varargElementType))
             }

compiler/testData/diagnostics/testsWithUnsignedTypes/allowedVarargsOfUnsignedTypes.kt

@@ -0,0 +1,14 @@
+// !LANGUAGE: +InlineClasses
+// !SKIP_METADATA_VERSION_CHECK
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+fun ubyte(vararg a: UByte) {}
+fun ushort(vararg a: UShort) {}
+fun uint(vararg a: UInt) {}
+fun ulong(vararg a: ULong) {}
+
+class ValueParam(vararg val a: ULong)
+
+annotation class Ann(vararg val a: <!INVALID_TYPE_OF_ANNOTATION_MEMBER!>UInt<!>)
+
+fun array(<!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> a: UIntArray) {}

compiler/testData/diagnostics/testsWithUnsignedTypes/allowedVarargsOfUnsignedTypes.txt

@@ -0,0 +1,23 @@
+package
+
+public fun array(/*0*/ vararg a: kotlin.UIntArray /*kotlin.Array<out kotlin.UIntArray>*/): kotlin.Unit
+public fun ubyte(/*0*/ vararg a: kotlin.UByte /*kotlin.Array<out kotlin.UByte>*/): kotlin.Unit
+public fun uint(/*0*/ vararg a: kotlin.UInt /*kotlin.Array<out kotlin.UInt>*/): kotlin.Unit
+public fun ulong(/*0*/ vararg a: kotlin.ULong /*kotlin.Array<out kotlin.ULong>*/): kotlin.Unit
+public fun ushort(/*0*/ vararg a: kotlin.UShort /*kotlin.Array<out kotlin.UShort>*/): kotlin.Unit
+
+public final annotation class Ann : kotlin.Annotation {
+    public constructor Ann(/*0*/ vararg a: kotlin.UInt /*kotlin.Array<out kotlin.UInt>*/)
+    public final val a: kotlin.Array<out kotlin.UInt>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class ValueParam {
+    public constructor ValueParam(/*0*/ vararg a: kotlin.ULong /*kotlin.Array<out kotlin.ULong>*/)
+    public final val a: kotlin.Array<out kotlin.ULong>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsWithUnsignedTypesGenerated.java

@@ -29,6 +29,11 @@ public class DiagnosticsWithUnsignedTypesGenerated extends AbstractDiagnosticsWi
         KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/testsWithUnsignedTypes"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
     }
 
+    @TestMetadata("allowedVarargsOfUnsignedTypes.kt")
+    public void testAllowedVarargsOfUnsignedTypes() throws Exception {
+        runTest("compiler/testData/diagnostics/testsWithUnsignedTypes/allowedVarargsOfUnsignedTypes.kt");
+    }
+
     @TestMetadata("forbiddenEqualsOnUnsignedTypes.kt")
     public void testForbiddenEqualsOnUnsignedTypes() throws Exception {
         runTest("compiler/testData/diagnostics/testsWithUnsignedTypes/forbiddenEqualsOnUnsignedTypes.kt");