'hasSyntaxErrors' check moved from Diagnostic to PositioningStrategy

This makes possible to mark diagnostic errors when syntax error are present (by overriding isValid in PositioningStrategy subclasses).

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

@@ -71,20 +71,7 @@ public abstract class AbstractDiagnostic<E extends PsiElement> implements Parame
     @Override
     public boolean isValid() {
         if (!getFactory().isValid(this)) return false;
-        if (hasSyntaxErrors(psiElement)) return false;
         if (psiElement.getNode().findChildByType(JetNodeTypes.IDE_TEMPLATE_EXPRESSION) != null) return false;
         return true;
     }
-
-    private static boolean hasSyntaxErrors(@NotNull PsiElement psiElement) {
-        if (psiElement instanceof PsiErrorElement) return true;
-
-        PsiElement lastChild = psiElement.getLastChild();
-        if (lastChild != null && hasSyntaxErrors(lastChild)) return true;
-
-        PsiElement[] children = psiElement.getChildren();
-        if (children.length > 0 && hasSyntaxErrors(children[children.length - 1])) return true;
-
-        return false;
-    }
 }

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

@@ -139,7 +139,7 @@ public class PositioningStrategies {
         }
         @Override
         public boolean isValid(@NotNull PsiNameIdentifierOwner element) {
-            return element.getNameIdentifier() != null;
+            return element.getNameIdentifier() != null && super.isValid(element);
         }
     };
 
@@ -299,6 +299,8 @@ public class PositioningStrategies {
 
         @Override
         public boolean isValid(@NotNull JetDeclarationWithBody element) {
+            if (!super.isValid(element)) return false;
+
             JetExpression bodyExpression = element.getBodyExpression();
             if (!(bodyExpression instanceof JetBlockExpression)) return false;
             if (((JetBlockExpression) bodyExpression).getLastBracketRange() == null) return false;

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

@@ -32,7 +32,7 @@ public class PositioningStrategy<E extends PsiElement> {
     }
 
     public boolean isValid(@NotNull E element) {
-        return true;
+        return !hasSyntaxErrors(element);
     }
 
     @NotNull
@@ -49,4 +49,16 @@ public class PositioningStrategy<E extends PsiElement> {
     protected static List<TextRange> markRange(@NotNull TextRange range) {
         return Collections.singletonList(range);
     }
+
+    protected static boolean hasSyntaxErrors(@NotNull PsiElement psiElement) {
+        if (psiElement instanceof PsiErrorElement) return true;
+
+        PsiElement lastChild = psiElement.getLastChild();
+        if (lastChild != null && hasSyntaxErrors(lastChild)) return true;
+
+        PsiElement[] children = psiElement.getChildren();
+        if (children.length > 0 && hasSyntaxErrors(children[children.length - 1])) return true;
+
+        return false;
+    }
 }