KT-2697 Prohibit enum inheritance

#KT-2697 Fixed

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java

@@ -253,6 +253,7 @@ public interface Errors {
     SimpleDiagnosticFactory<JetTypeReference> MANY_CLASSES_IN_SUPERTYPE_LIST = SimpleDiagnosticFactory.create(ERROR);
     SimpleDiagnosticFactory<JetTypeReference> SUPERTYPE_NOT_A_CLASS_OR_TRAIT = SimpleDiagnosticFactory.create(ERROR);
     SimpleDiagnosticFactory<PsiElement> SUPERTYPE_INITIALIZED_IN_TRAIT = SimpleDiagnosticFactory.create(ERROR);
+    SimpleDiagnosticFactory<PsiElement> CLASS_IN_SUPERTYPE_FOR_ENUM = SimpleDiagnosticFactory.create(ERROR);
     SimpleDiagnosticFactory<PsiElement> CONSTRUCTOR_IN_TRAIT = SimpleDiagnosticFactory.create(ERROR);
     SimpleDiagnosticFactory<JetTypeReference> SUPERTYPE_APPEARS_TWICE = SimpleDiagnosticFactory.create(ERROR);
     SimpleDiagnosticFactory<JetTypeReference> FINAL_SUPERTYPE = SimpleDiagnosticFactory.create(ERROR);

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/DefaultErrorMessages.java

@@ -281,6 +281,7 @@ public class DefaultErrorMessages {
         MAP.put(MANY_CLASSES_IN_SUPERTYPE_LIST, "Only one class may appear in a supertype list");
         MAP.put(SUPERTYPE_NOT_A_CLASS_OR_TRAIT, "Only classes and traits may serve as supertypes");
         MAP.put(SUPERTYPE_INITIALIZED_IN_TRAIT, "Traits cannot initialize supertypes");
+        MAP.put(CLASS_IN_SUPERTYPE_FOR_ENUM, "Enum class cannot inherit from classes");
         MAP.put(CONSTRUCTOR_IN_TRAIT, "A trait may not have a constructor");
         MAP.put(SUPERTYPE_APPEARS_TWICE, "A supertype appears twice");
         MAP.put(FINAL_SUPERTYPE, "This type is final, so it cannot be inherited from");

compiler/frontend/src/org/jetbrains/jet/lang/resolve/BodyResolver.java

@@ -287,6 +287,9 @@ public class BodyResolver {
             ClassDescriptor classDescriptor = TypeUtils.getClassDescriptor(supertype);
             if (classDescriptor != null) {
                 if (classDescriptor.getKind() != ClassKind.TRAIT) {
+                    if (supertypeOwner.getKind() == ClassKind.ENUM_CLASS) {
+                        trace.report(CLASS_IN_SUPERTYPE_FOR_ENUM.on(typeReference));
+                    }
                     if (classAppeared) {
                         trace.report(MANY_CLASSES_IN_SUPERTYPE_LIST.on(typeReference));
                     }

compiler/testData/diagnostics/tests/enum/enumInheritance.kt

@@ -0,0 +1,11 @@
+// FILE: test.kt
+enum class MyEnum(): <!CLASS_IN_SUPERTYPE_FOR_ENUM!>MyClass<!>() {}
+enum class MyEnum2(): MyTrait {}
+enum class MyEnum3(): <!INVISIBLE_MEMBER, CLASS_IN_SUPERTYPE_FOR_ENUM, FINAL_SUPERTYPE!>MyEnumBase<!>() {}
+
+open class MyClass() {}
+
+enum class MyEnumBase() {}
+
+trait MyTrait {}
+

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -1229,6 +1229,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.checkers.AbstractDiagnosticsTestWithEagerResolve", new File("compiler/testData/diagnostics/tests/enum"), "kt", true);
             }
             
+            @TestMetadata("enumInheritance.kt")
+            public void testEnumInheritance() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/enum/enumInheritance.kt");
+            }
+            
             @TestMetadata("enumStarImport.kt")
             public void testEnumStarImport() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/enum/enumStarImport.kt");