Assert that reference annotation argument is always an enum value

Rename JavaReferenceAnnotationArgument on that occasion to
JavaEnumValueAnnotationArgument. Also add a test on a nested enum annotation
argument

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/structure/impl/JavaAnnotationArgumentImpl.java

@@ -39,7 +39,7 @@ public abstract class JavaAnnotationArgumentImpl<Psi extends PsiAnnotationMember
         }
 
         if (argument instanceof PsiReferenceExpression) {
-            return new JavaReferenceAnnotationArgumentImpl((PsiReferenceExpression) argument, name);
+            return new JavaEnumValueAnnotationArgumentImpl((PsiReferenceExpression) argument, name);
         }
         else if (argument instanceof PsiArrayInitializerMemberValue) {
             return new JavaArrayAnnotationArgumentImpl((PsiArrayInitializerMemberValue) argument, name);

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/structure/impl/JavaEnumValueAnnotationArgumentImpl.java

@@ -22,25 +22,24 @@ import com.intellij.psi.PsiField;
 import com.intellij.psi.PsiReferenceExpression;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.lang.resolve.java.structure.JavaElement;
-import org.jetbrains.jet.lang.resolve.java.structure.JavaReferenceAnnotationArgument;
+import org.jetbrains.jet.lang.resolve.java.structure.JavaEnumValueAnnotationArgument;
+import org.jetbrains.jet.lang.resolve.java.structure.JavaField;
 import org.jetbrains.jet.lang.resolve.name.Name;
 
-public class JavaReferenceAnnotationArgumentImpl extends JavaAnnotationArgumentImpl<PsiReferenceExpression>
-        implements JavaReferenceAnnotationArgument {
-    protected JavaReferenceAnnotationArgumentImpl(@NotNull PsiReferenceExpression psiReferenceExpression, @Nullable Name name) {
+public class JavaEnumValueAnnotationArgumentImpl extends JavaAnnotationArgumentImpl<PsiReferenceExpression>
+        implements JavaEnumValueAnnotationArgument {
+    protected JavaEnumValueAnnotationArgumentImpl(@NotNull PsiReferenceExpression psiReferenceExpression, @Nullable Name name) {
         super(psiReferenceExpression, name);
     }
 
     @Override
     @Nullable
-    public JavaElement resolve() {
-        PsiReferenceExpression expression = getPsi();
-        PsiElement element = expression.resolve();
-        if (element instanceof PsiEnumConstant) {
-            return new JavaFieldImpl((PsiField) element);
+    public JavaField resolve() {
+        PsiElement element = getPsi().resolve();
+        if (element == null) return null;
+        if (!(element instanceof PsiEnumConstant)) {
+            throw new IllegalStateException("Reference argument should be an enum value, but was " + element + ": " + element.getText());
         }
-        // TODO: other types of references
-        return null;
+        return new JavaFieldImpl((PsiField) element);
     }
 }

compiler/testData/loadJava/compiledJava/annotations/NestedEnumArgument.java

@@ -0,0 +1,14 @@
+package test;
+
+public class NestedEnumArgument {
+    public enum E {
+        FIRST
+    }
+
+    @interface Anno {
+        E value();
+    }
+
+    @Anno(E.FIRST)
+    void foo() {}
+}

compiler/testData/loadJava/compiledJava/annotations/NestedEnumArgument.txt

@@ -0,0 +1,33 @@
+package test
+
+public open class NestedEnumArgument {
+    public constructor NestedEnumArgument()
+    test.NestedEnumArgument.Anno(value = E.FIRST: test.NestedEnumArgument.E) public/*package*/ open fun foo(): kotlin.Unit
+
+    public/*package*/ final annotation class Anno : kotlin.Annotation {
+        public/*package*/ constructor Anno(/*0*/ value: test.NestedEnumArgument.E)
+        public abstract fun value(): test.NestedEnumArgument.E
+    }
+
+    public final enum class E : kotlin.Enum<test.NestedEnumArgument.E> {
+        private constructor E()
+        public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
+        public final override /*1*/ /*fake_override*/ fun ordinal(): kotlin.Int
+
+        public enum entry FIRST : test.NestedEnumArgument.E {
+            private constructor FIRST()
+            public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
+            public final override /*1*/ /*fake_override*/ fun ordinal(): kotlin.Int
+
+            public class object <class-object-for-FIRST> : test.NestedEnumArgument.E.FIRST {
+                private constructor <class-object-for-FIRST>()
+                public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
+                public final override /*1*/ /*fake_override*/ fun ordinal(): kotlin.Int
+            }
+        }
+
+        // Static members
+        public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): test.NestedEnumArgument.E
+        public final /*synthesized*/ fun values(): kotlin.Array<test.NestedEnumArgument.E>
+    }
+}

compiler/tests/org/jetbrains/jet/jvm/compiler/LoadJavaTestGenerated.java

@@ -374,6 +374,12 @@ public class LoadJavaTestGenerated extends AbstractLoadJavaTest {
                 doTestCompiledJava(fileName);
             }
             
+            @TestMetadata("NestedEnumArgument.java")
+            public void testNestedEnumArgument() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/loadJava/compiledJava/annotations/NestedEnumArgument.java");
+                doTestCompiledJava(fileName);
+            }
+            
             @TestMetadata("PrimitiveValueInParam.java")
             public void testPrimitiveValueInParam() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/loadJava/compiledJava/annotations/PrimitiveValueInParam.java");

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/lazy/descriptors/LazyJavaAnnotationDescriptor.kt

@@ -100,7 +100,7 @@ class LazyJavaAnnotationDescriptor(
     private fun resolveAnnotationArgument(argument: JavaAnnotationArgument?): CompileTimeConstant<*>? {
         return when (argument) {
             is JavaLiteralAnnotationArgument -> createCompileTimeConstant(argument.getValue(), true, false, false, null)
-            is JavaReferenceAnnotationArgument -> resolveFromReference(argument.resolve())
+            is JavaEnumValueAnnotationArgument -> resolveFromEnumValue(argument.resolve())
             is JavaArrayAnnotationArgument -> resolveFromArray(argument.getName() ?: DEFAULT_ANNOTATION_MEMBER_NAME, argument.getElements())
             is JavaAnnotationAsAnnotationArgument -> resolveFromAnnotation(argument.getAnnotation())
             is JavaClassObjectAnnotationArgument -> resolveFromJavaClassObjectType(argument.getReferencedType())
@@ -131,10 +131,8 @@ class LazyJavaAnnotationDescriptor(
         return ArrayValue(values, valueParameter.getType(), true, values.any { it.usesVariableAsConstant() })
     }
 
-    private fun resolveFromReference(element: JavaElement?): CompileTimeConstant<*>? {
-        if (element !is JavaField) return null
-
-        if (!element.isEnumEntry()) return null
+    private fun resolveFromEnumValue(element: JavaField?): CompileTimeConstant<*>? {
+        if (element == null || !element.isEnumEntry()) return null
 
         val containingJavaClass = element.getContainingClass()
 

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/structure/JavaEnumValueAnnotationArgument.java

@@ -18,7 +18,7 @@ package org.jetbrains.jet.lang.resolve.java.structure;
 
 import org.jetbrains.annotations.Nullable;
 
-public interface JavaReferenceAnnotationArgument extends JavaAnnotationArgument {
+public interface JavaEnumValueAnnotationArgument extends JavaAnnotationArgument {
     @Nullable
-    JavaElement resolve();
+    JavaField resolve();
 }