Prohibit varargs on parameters of inline class types

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -318,7 +318,6 @@ public interface Errors {
     DiagnosticFactory0<KtParameter> INLINE_CLASS_CONSTRUCTOR_NOT_FINAL_READ_ONLY_PARAMETER = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<PsiElement> INLINE_CLASS_WITH_INITIALIZER = DiagnosticFactory0.create(ERROR);
 
-
     // Secondary constructors
 
     DiagnosticFactory0<KtConstructorDelegationReferenceExpression> CYCLIC_CONSTRUCTOR_DELEGATION_CALL = DiagnosticFactory0.create(ERROR);

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -630,7 +630,7 @@ public class DefaultErrorMessages {
         MAP.put(NON_PUBLIC_PRIMARY_CONSTRUCTOR_OF_INLINE_CLASS, "Primary constructor of inline class must be public");
         MAP.put(INLINE_CLASS_CONSTRUCTOR_WRONG_PARAMETERS_SIZE, "Inline class must have exactly one primary constructor parameter");
         MAP.put(INLINE_CLASS_CONSTRUCTOR_NOT_FINAL_READ_ONLY_PARAMETER, "Inline class primary constructor must have only final read-only (val) property parameter");
-        MAP.put(INLINE_CLASS_WITH_INITIALIZER, "Inline class cannot have initializer block");
+        MAP.put(INLINE_CLASS_WITH_INITIALIZER, "Inline class cannot have an initializer block");
 
         MAP.put(VARIANCE_ON_TYPE_PARAMETER_NOT_ALLOWED, "Variance annotations are only allowed for type parameters of classes and interfaces");
         MAP.put(BOUND_ON_TYPE_ALIAS_PARAMETER_NOT_ALLOWED, "Bounds are not allowed on type alias parameters");

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

@@ -918,7 +918,7 @@ class DeclarationsChecker(
         val nullableNothing = callableDescriptor.builtIns.nullableNothingType
         for (parameter in varargParameters) {
             val varargElementType = parameter.varargElementType!!.upperIfFlexible()
-            if (KotlinTypeChecker.DEFAULT.isSubtypeOf(varargElementType, nullableNothing)) {
+            if (KotlinTypeChecker.DEFAULT.isSubtypeOf(varargElementType, nullableNothing) || varargElementType.isInlineClassType()) {
                 val parameterDeclaration = DescriptorToSourceUtils.descriptorToDeclaration(parameter) as? KtParameter ?: continue
                 trace.report(FORBIDDEN_VARARG_PARAMETER_TYPE.on(parameterDeclaration, varargElementType))
             }

compiler/testData/diagnostics/tests/inlineClasses/varargsOnParametersOfInlineClassType.kt

@@ -0,0 +1,21 @@
+// !LANGUAGE: +InlineClasses
+// !DIAGNOSTICS: -UNUSED_PARAMETER, -UNUSED_VARIABLE, -UNUSED_ANONYMOUS_PARAMETER
+
+inline class Foo(val x: Int)
+
+fun f1(<!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> a: Foo) {}
+fun f2(<!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> a: Foo?) {}
+
+class A {
+    fun f3(a0: Int, <!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> a1: Foo) {
+        fun f4(<!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> a: Foo) {}
+
+        val g = fun (<!USELESS_VARARG_ON_PARAMETER!><!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> v: Foo<!>) {}
+    }
+}
+
+class B(<!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> val s: Foo) {
+    constructor(a: Int, <!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> s: Foo) : this(*s)
+}
+
+annotation class Ann(<!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> val f: <!INVALID_TYPE_OF_ANNOTATION_MEMBER!>Foo<!>)

compiler/testData/diagnostics/tests/inlineClasses/varargsOnParametersOfInlineClassType.txt

@@ -0,0 +1,37 @@
+package
+
+public fun f1(/*0*/ vararg a: Foo /*kotlin.Array<out Foo>*/): kotlin.Unit
+public fun f2(/*0*/ vararg a: Foo? /*kotlin.Array<out Foo?>*/): kotlin.Unit
+
+public final class A {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun f3(/*0*/ a0: kotlin.Int, /*1*/ vararg a1: Foo /*kotlin.Array<out Foo>*/): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final annotation class Ann : kotlin.Annotation {
+    public constructor Ann(/*0*/ vararg f: Foo /*kotlin.Array<out Foo>*/)
+    public final val f: kotlin.Array<out Foo>
+    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 B {
+    public constructor B(/*0*/ vararg s: Foo /*kotlin.Array<out Foo>*/)
+    public constructor B(/*0*/ a: kotlin.Int, /*1*/ vararg s: Foo /*kotlin.Array<out Foo>*/)
+    public final val s: kotlin.Array<out Foo>
+    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 inline class Foo {
+    public constructor Foo(/*0*/ x: kotlin.Int)
+    public final val x: kotlin.Int
+    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/DiagnosticsTestGenerated.java

@@ -10692,6 +10692,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
             public void testPresenceOfPublicPrimaryConstructorForInlineClass() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/inlineClasses/presenceOfPublicPrimaryConstructorForInlineClass.kt");
             }
+
+            @TestMetadata("varargsOnParametersOfInlineClassType.kt")
+            public void testVarargsOnParametersOfInlineClassType() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inlineClasses/varargsOnParametersOfInlineClassType.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/diagnostics/tests/inner")

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -10692,6 +10692,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
             public void testPresenceOfPublicPrimaryConstructorForInlineClass() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/inlineClasses/presenceOfPublicPrimaryConstructorForInlineClass.kt");
             }
+
+            @TestMetadata("varargsOnParametersOfInlineClassType.kt")
+            public void testVarargsOnParametersOfInlineClassType() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inlineClasses/varargsOnParametersOfInlineClassType.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/diagnostics/tests/inner")