refactored OvershadowingSubclassFields so you can now suppress the ch…

…eck on

individual fields

Fixes #668

MOE_MIGRATED_REVID=161142216

core/src/main/java/com/google/errorprone/bugpatterns/OvershadowingSubclassFields.java

@@ -66,7 +66,11 @@ public Description matchClass(ClassTree classTree, VisitorState visitorState) {
             .stream()
             .filter(mem -> mem instanceof VariableTree)
             .map(mem -> (VariableTree) mem)
-            .filter(mem -> !isIgnoredType(mem) && !isStatic(mem))
+            .filter(
+                mem ->
+                    !isSuppressed(ASTHelpers.getSymbol(mem))
+                        && !isIgnoredType(mem)
+                        && !isStatic(mem))
             .collect(toCollection(ArrayList::new));
 
     ClassSymbol classSymbol = ASTHelpers.getSymbol(classTree);

core/src/test/java/com/google/errorprone/bugpatterns/testdata/OvershadowingSubclassFieldsNegativeCases.java

@@ -22,19 +22,28 @@
 public class OvershadowingSubclassFieldsNegativeCases {
   // base class
   static class ClassA {
-    private int varOne;
+    public int varOne;
   }
 
   // subclass with member variables of different names
   static class ClassB extends ClassA {
     private String varTwo;
     private int varThree;
     public static int varFour;
+    public int varFive;
   }
 
   // subclass with initialized member variable of different name
   static class ClassC extends ClassB {
     private String varFour = "Test";
+
+    // warning suppressed when overshadowing variable in parent
+    @SuppressWarnings("OvershadowingSubclassFields")
+    public int varFive;
+
+    // warning suppressed when overshadowing variable in grandparent
+    @SuppressWarnings("OvershadowingSubclassFields")
+    public int varOne;
   }
 
   // subclass with member *methods* with the same name as superclass member variable -- this is ok

core/src/test/java/com/google/errorprone/bugpatterns/testdata/OvershadowingSubclassFieldsPositiveCases1.java

@@ -55,10 +55,21 @@ public static class ClassD extends ClassB {
     String randTwo;
   }
 
-  /** ClassF has same variable name as grandparent */
-  public static class ClassF extends ClassC {
+  /** ClassE has same variable name as grandparent */
+  public static class ClassE extends ClassC {
     // BUG: Diagnostic contains: Overshadowing variables of superclass causes confusion and errors.
     // This variable is overshadowing a variable in superclass:  ClassC
     public String varTwo;
   }
+
+  public static class ClassF extends ClassA {
+    @SuppressWarnings("OvershadowingSubclassFields") // no warning because it's suppressed
+    public String varThree;
+  }
+
+  public static class ClassG extends ClassF {
+    // BUG: Diagnostic contains: Overshadowing variables of superclass causes confusion and errors.
+    // This variable is overshadowing a variable in superclass:  ClassF
+    String varThree;
+  }
 }