No compile-time error when overriding a static field or method

compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java

Index: compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
diff --git a/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java b/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
index 05a662ff741349eb11f8672adb5b89d2a5383cc3..2d367b89840ade2eade806945e3d0305d7e66012 100644
--- a/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
+++ b/compiler/java/com/google/dart/compiler/type/TypeAnalyzer.java
@@ -1705,7 +1705,7 @@ public class TypeAnalyzer implements DartCompilationPhase {
               typeError(parameterElement, TypeErrorCode.SETTER_TYPE_MUST_BE_ASSIGNABLE,
                   setterType.getElement().getName(), getterType.getElement().getName());
             }
-            
+
             // getter and setter should have same "static" flag
             if (modifiers.isStatic() != getterElement.getModifiers().isStatic()) {
               onError(node.getName(), ResolverErrorCode.FIELD_GETTER_SETTER_SAME_STATIC);
@@ -2659,20 +2659,23 @@ public class TypeAnalyzer implements DartCompilationPhase {
           FieldElement field = node.getElement();
           String name = field.getName();
           Collection<Element> overridden = superMembers.removeAll(name);
-          for (Element element : overridden) {
-            if (canOverride(node.getName(), field.getModifiers(), element)) {
-              switch (element.getKind()) {
-                case FIELD:
-                  checkOverride(node.getName(), field, element);
-                  break;
-                case METHOD:
-                  typeError(node.getName(), TypeErrorCode.SUPERTYPE_HAS_METHOD, name,
-                            element.getEnclosingElement().getName());
-                  break;
-
-                default:
-                  typeError(node, TypeErrorCode.INTERNAL_ERROR, element);
-                  break;
+          for (Element superElement : overridden) {
+            if (!(field.isStatic() && superElement.getModifiers().isStatic())) {
+              if (canOverride(node.getName(), field.getModifiers(), superElement)
+                  && !superElement.getModifiers().isStatic()) {

[zundel, 2012/06/27 21:30:58]

A static member in the superclass isn't in the way, but needs a warning.

These two if stmts are pretty tricky.  The 'canOverride()' method has a side
effect, so it needs to be tested first before
!superElement.getModifiers.isStatic() 
I'm open to ideas for simplification?

+                switch (superElement.getKind()) {
+                  case FIELD:
+                    checkOverride(node.getName(), field, superElement);
+                    break;
+                  case METHOD:
+                    typeError(node.getName(), TypeErrorCode.SUPERTYPE_HAS_METHOD, name,
+                        superElement.getEnclosingElement().getName());
+                    break;
+
+                  default:
+                    typeError(node, TypeErrorCode.INTERNAL_ERROR, superElement);
+                    break;
+                }
               }
             }
           }
@@ -2692,21 +2695,25 @@ public class TypeAnalyzer implements DartCompilationPhase {
             typeError(node.getName(), ResolverErrorCode.INVALID_OVERRIDE_METADATA);
           }
           // Check that override is valid.
-          for (Element element : overridden) {
-            if (canOverride(node.getName(), method.getModifiers(), element)) {
-              switch (element.getKind()) {
-                case METHOD:
-                  checkOverride(node.getName(), method, element);
-                  break;
-
-                case FIELD:
-                  typeError(node.getName(), TypeErrorCode.SUPERTYPE_HAS_FIELD, element.getName(),
-                            element.getEnclosingElement().getName());
-                  break;
-
-                default:
-                  typeError(node, TypeErrorCode.INTERNAL_ERROR, element);
-                  break;
+          for (Element superElement : overridden) {
+            if (!(method.isStatic() && superElement.getModifiers().isStatic())) {
+              if (canOverride(node.getName(), method.getModifiers(), superElement)
+                  && !superElement.getModifiers().isStatic()) {
+                switch (superElement.getKind()) {
+                  case METHOD:
+                    checkOverride(node.getName(), method, superElement);
+                    break;
+
+                  case FIELD:
+                    typeError(node.getName(), TypeErrorCode.SUPERTYPE_HAS_FIELD, superElement.getName(),
+                        superElement.getEnclosingElement().getName());
+
+                    break;
+
+                  default:
+                    typeError(node, TypeErrorCode.INTERNAL_ERROR, superElement);
+                    break;
+                }
               }
             }
           }
@@ -2715,18 +2722,20 @@ public class TypeAnalyzer implements DartCompilationPhase {
       }
 
       /**
-       * Report a compile-time error if either modifiers or elements.getModifiers() is static.
+       * Report a compile-time error if a static member tries to override an instance member
        * @returns true if no compile-time error was reported
        */
-      private boolean canOverride(HasSourceInfo errorTarget, Modifiers modifiers, Element element) {
-        if (element.getModifiers().isStatic()) {
-          onError(errorTarget, TypeErrorCode.OVERRIDING_INHERITED_STATIC_MEMBER,
-                          element.getName(), element.getEnclosingElement().getName());
-          return false;
-        } else if (modifiers.isStatic()) {
+      private boolean canOverride(HasSourceInfo errorTarget, Modifiers modifiers,
+          Element superElement) {
+        if (!superElement.getModifiers().isStatic() && modifiers.isStatic()) {
           onError(errorTarget, ResolverErrorCode.CANNOT_OVERRIDE_INSTANCE_MEMBER,
-                          element.getName(), element.getEnclosingElement().getName());
+                          superElement.getName(), superElement.getEnclosingElement().getName());
           return false;
+        } else if (superElement.getModifiers().isStatic() && !modifiers.isStatic()) {
+            onError(errorTarget, TypeErrorCode.OVERRIDING_INHERITED_STATIC_MEMBER,
+                superElement.getName(), superElement.getEnclosingElement().getName());
+          // Although a warning, override is allowed anyway
+          return true;
         }
         return true;
       }