Add warning when 'val' keyword on annotation parameter is missing

#KT-1900

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

@@ -111,6 +111,7 @@ public interface Errors {
 
     // Annotations
 
+    DiagnosticFactory0<JetParameter> MISSING_VAL_ON_ANNOTATION_PARAMETER = DiagnosticFactory0.create(WARNING);
     DiagnosticFactory0<JetCallExpression> ANNOTATION_CLASS_CONSTRUCTOR_CALL = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory1<JetAnnotationEntry, String> NOT_AN_ANNOTATION_CLASS = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory0<PsiElement> ANNOTATION_CLASS_WITH_BODY = DiagnosticFactory0.create(ERROR);

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

@@ -451,6 +451,7 @@ public class DefaultErrorMessages {
 
         MAP.put(TYPE_PARAMETER_AS_REIFIED, "Cannot use ''{0}'' as reified type parameter. Use a class instead.", NAME);
 
+        MAP.put(MISSING_VAL_ON_ANNOTATION_PARAMETER, "'val' keyword is missing on annotation parameter");
         MAP.put(ANNOTATION_CLASS_CONSTRUCTOR_CALL, "Annotation class cannot be instantiated");
         MAP.put(NOT_AN_ANNOTATION_CLASS, "''{0}'' is not an annotation class", TO_STRING);
         MAP.put(ANNOTATION_CLASS_WITH_BODY, "Body is not allowed for annotation class");

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

@@ -277,6 +277,8 @@ public class DeclarationResolver {
             }
         }
 
+        boolean isAnnotationClass = DescriptorUtils.isAnnotationClass(classDescriptor);
+
         // TODO : not all the parameters are real properties
         JetScope memberScope = classDescriptor.getScopeForSupertypeResolution();
         ConstructorDescriptor constructorDescriptor = descriptorResolver.resolvePrimaryConstructorDescriptor(memberScope, classDescriptor, klass, trace);
@@ -298,6 +300,9 @@ public class DeclarationResolver {
                     context.getPrimaryConstructorParameterProperties().put(parameter, propertyDescriptor);
                 }
                 else {
+                    if (isAnnotationClass) {
+                        trace.report(MISSING_VAL_ON_ANNOTATION_PARAMETER.on(parameter));
+                    }
                     notProperties.add(valueParameterDescriptor);
                 }
             }

compiler/testData/diagnostics/tests/annotations/BasicAnnotations.kt

@@ -1,6 +1,6 @@
 annotation class my
-annotation class my1(i : Int)
+annotation class my1(val i : Int)
-annotation class my2(i : Int = 0)
+annotation class my2(val i : Int = 0)
 
 my fun foo() {}
 <!NO_VALUE_FOR_PARAMETER!>my1<!> fun foo2() {}

compiler/testData/diagnostics/tests/annotations/kt1886annotationBody.kt

@@ -24,6 +24,6 @@ annotation class Annotation7(val name: String) <!ANNOTATION_CLASS_WITH_BODY!>{}<
 
 annotation class Annotation8(var name: String = "") <!ANNOTATION_CLASS_WITH_BODY!>{}<!>
 
-annotation class Annotation9(name: String)
+annotation class Annotation9(val name: String)
 
 annotation class Annotation10

compiler/testData/diagnostics/tests/annotations/missingValOnParameter.kt

@@ -0,0 +1,5 @@
+annotation class Ann(
+        val a: Int,
+        var b: Int,
+        <!MISSING_VAL_ON_ANNOTATION_PARAMETER!>c: String<!>
+        )

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

@@ -610,6 +610,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest("compiler/testData/diagnostics/tests/annotations/kt1886annotationBody.kt");
             }
             
+            @TestMetadata("missingValOnParameter.kt")
+            public void testMissingValOnParameter() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/annotations/missingValOnParameter.kt");
+            }
+            
             @TestMetadata("NonAnnotationClass.kt")
             public void testNonAnnotationClass() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/annotations/NonAnnotationClass.kt");