Warning for open members in objects

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

@@ -301,6 +301,9 @@ public interface Errors {
     DiagnosticFactory0<KtNamedDeclaration> NON_FINAL_MEMBER_IN_FINAL_CLASS = DiagnosticFactory0.create(WARNING, modifierSetPosition(
             KtTokens.OPEN_KEYWORD));
 
+    DiagnosticFactory0<KtNamedDeclaration> NON_FINAL_MEMBER_IN_OBJECT = DiagnosticFactory0.create(WARNING, modifierSetPosition(
+            KtTokens.OPEN_KEYWORD));
+
     DiagnosticFactory1<KtModifierListOwner, CallableMemberDescriptor> NOTHING_TO_OVERRIDE = DiagnosticFactory1.create(ERROR, OVERRIDE_MODIFIER);
 
     DiagnosticFactory3<KtNamedDeclaration, CallableMemberDescriptor, CallableMemberDescriptor, DeclarationDescriptor> VIRTUAL_MEMBER_HIDDEN =

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

@@ -249,6 +249,7 @@ public class DefaultErrorMessages {
         MAP.put(FUNCTION_DECLARATION_WITH_NO_NAME, "Function declaration must have a name");
         MAP.put(ANONYMOUS_FUNCTION_WITH_NAME, "Anonymous functions with names are prohibited");
         MAP.put(NON_FINAL_MEMBER_IN_FINAL_CLASS, "\"open\" has no effect in a final class");
+        MAP.put(NON_FINAL_MEMBER_IN_OBJECT, "\"open\" has no effect in an object");
 
         MAP.put(ANONYMOUS_FUNCTION_PARAMETER_WITH_DEFAULT_VALUE, "An anonymous function is not allowed to specify default values for its parameters");
         MAP.put(USELESS_VARARG_ON_PARAMETER, "Vararg on this parameter is useless");

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

@@ -310,7 +310,8 @@ class DeclarationsChecker(
         }
     }
 
-    private fun checkObject(declaration: KtObjectDeclaration, classDescriptor: ClassDescriptor) {
+    private fun checkObject(declaration: KtObjectDeclaration, classDescriptor: ClassDescriptorWithResolutionScopes) {
+        checkOpenMembers(classDescriptor)
         if (declaration.isLocal() && !declaration.isCompanion() && !declaration.isObjectLiteral()) {
             trace.report(LOCAL_OBJECT_NOT_ALLOWED.on(declaration, classDescriptor))
         }
@@ -433,7 +434,12 @@ class DeclarationsChecker(
             if (memberDescriptor.kind != CallableMemberDescriptor.Kind.DECLARATION) continue
             val member = DescriptorToSourceUtils.descriptorToDeclaration(memberDescriptor) as? KtNamedDeclaration
             if (member != null && member.hasModifier(KtTokens.OPEN_KEYWORD)) {
-                trace.report(NON_FINAL_MEMBER_IN_FINAL_CLASS.on(member))
+                if (classDescriptor.kind == ClassKind.OBJECT) {
+                    trace.report(NON_FINAL_MEMBER_IN_OBJECT.on(member))
+                }
+                else {
+                    trace.report(NON_FINAL_MEMBER_IN_FINAL_CLASS.on(member))
+                }
             }
         }
     }

compiler/testData/diagnostics/tests/objects/OpenInObject.kt

@@ -0,0 +1,9 @@
+object Obj {
+    fun foo() {}
+
+    <!NON_FINAL_MEMBER_IN_OBJECT!>open<!> fun bar() {}
+
+    var x: Int = 0
+
+    <!NON_FINAL_MEMBER_IN_OBJECT!>open<!> var y: Int = 1
+}

compiler/testData/diagnostics/tests/objects/OpenInObject.txt

@@ -0,0 +1,12 @@
+package
+
+public object Obj {
+    private constructor Obj()
+    public final var x: kotlin.Int
+    public open var y: kotlin.Int
+    public open fun bar(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithStdLib/annotations/platformStatic/finalAndAbstract.kt

@@ -18,7 +18,7 @@ object B: A() {
 
     <!OVERRIDE_CANNOT_BE_STATIC!>@JvmStatic final override fun c()<!> {}
 
-    @JvmStatic open fun d() {}
+    @JvmStatic <!NON_FINAL_MEMBER_IN_OBJECT!>open<!> fun d() {}
 }
 
 class C {
@@ -30,6 +30,6 @@ class C {
 
         @JvmStatic final override fun c() {}
 
-        @JvmStatic open fun d() {}
+        @JvmStatic <!NON_FINAL_MEMBER_IN_OBJECT!>open<!> fun d() {}
     }
 }

compiler/testData/diagnostics/testsWithStdLib/annotations/platformStatic/property.kt

@@ -31,7 +31,7 @@ class A {
 
         <!OVERRIDE_CANNOT_BE_STATIC!>@JvmStatic override val base1: Int<!> = 0
 
-        @JvmStatic open fun f() {}
+        @JvmStatic <!NON_FINAL_MEMBER_IN_OBJECT!>open<!> fun f() {}
 
         override val base2: Int = 0
             <!OVERRIDE_CANNOT_BE_STATIC!>@JvmStatic get<!>

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

@@ -11349,6 +11349,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("OpenInObject.kt")
+            public void testOpenInObject() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/objects/OpenInObject.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("upperBoundViolated.kt")
             public void testUpperBoundViolated() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/objects/upperBoundViolated.kt");

idea/src/org/jetbrains/kotlin/idea/quickfix/QuickFixRegistrar.kt

@@ -111,6 +111,8 @@ class QuickFixRegistrar : QuickFixContributor {
         val removeOpenModifierFactory = RemoveModifierFix.createRemoveModifierFromListOwnerFactory(OPEN_KEYWORD)
         NON_FINAL_MEMBER_IN_FINAL_CLASS.registerFactory(AddModifierFix.createFactory(OPEN_KEYWORD, KtClass::class.java),
                                                         removeOpenModifierFactory)
+        NON_FINAL_MEMBER_IN_OBJECT.registerFactory(AddModifierFix.createFactory(OPEN_KEYWORD, KtClass::class.java),
+                                                   removeOpenModifierFactory)
 
         val removeModifierFactory = RemoveModifierFix.createRemoveModifierFactory()
         GETTER_VISIBILITY_DIFFERS_FROM_PROPERTY_VISIBILITY.registerFactory(removeModifierFactory)