Merge pull request #26 from steve-s/master

AvoidUnusedPrivateFieldsRule scans nested types for private fields usage.

2 files changed, 71 insertions, 12 deletions

diff --git a/gendarme/rules/Gendarme.Rules.Performance/AvoidUnusedPrivateFieldsRule.cs b/gendarme/rules/Gendarme.Rules.Performance/AvoidUnusedPrivateFieldsRule.cs
index bc8c0e52..c7d74a5c 100644
--- a/gendarme/rules/Gendarme.Rules.Performance/AvoidUnusedPrivateFieldsRule.cs
+++ b/gendarme/rules/Gendarme.Rules.Performance/AvoidUnusedPrivateFieldsRule.cs
@@ -105,36 +105,54 @@ namespace Gendarme.Rules.Performance {
 			// copy all fields into an hashset
 			fields.Clear ();
 			foreach (FieldDefinition field in type.Fields) {
-				if (!field.IsPrivate || field.IsLiteral)
+				if (!field.IsPrivate || field.IsLiteral || field.IsGeneratedCode ())
 					continue;
 
 				fields.Add (field);
 			}
 
 			// scan all methods, including constructors, to find if the field is used
+			if (fields.Count > 0) {
+				CheckFieldsUsageInType (type);
+			}
+
+			// scan nested types becuase they also have access to private fields of their parent
+			if (type.HasNestedTypes && fields.Count > 0) {
+				foreach (TypeDefinition nested in type.NestedTypes) {
+					CheckFieldsUsageInType (nested);
+				}
+			}
+
+			// check remaining (private) fields in the set
+			foreach (FieldDefinition field in fields) {
+				Runner.Report (field, Severity.Medium, Confidence.Normal);
+			}
+			return Runner.CurrentRuleResult;
+		}
+
+		private void CheckFieldsUsageInType (TypeDefinition type)
+		{
 			foreach (MethodDefinition method in type.Methods) {
 				if (!method.HasBody)
 					continue;
 
 				// don't check the method if it does not access any field
 				if (!OpCodeEngine.GetBitmask (method).Intersect (LoadStoreFields))
-					continue;
+						continue;
 
 				foreach (Instruction ins in method.Body.Instructions) {
-					FieldDefinition fd = ins.GetField ();
-					if (fd == null)
-						continue;
+						FieldDefinition fd = ins.GetField ();
+						if (fd == null)
+								continue;
 
-					fields.Remove (fd);
+						fields.Remove (fd);
 				}
+				
+				if (fields.Count == 0)
+					break;				
 			}
-
-			// check remaining (private) fields in the set
-			foreach (FieldDefinition field in fields) {
-				Runner.Report (field, Severity.Medium, Confidence.Normal);
-			}
-			return Runner.CurrentRuleResult;
 		}
+
 #if false
 		public void Bitmask ()
 		{
diff --git a/gendarme/rules/Gendarme.Rules.Performance/Test/AvoidUnusedPrivateFieldsTest.cs b/gendarme/rules/Gendarme.Rules.Performance/Test/AvoidUnusedPrivateFieldsTest.cs
index 212bebfb..dbb9f153 100644
--- a/gendarme/rules/Gendarme.Rules.Performance/Test/AvoidUnusedPrivateFieldsTest.cs
+++ b/gendarme/rules/Gendarme.Rules.Performance/Test/AvoidUnusedPrivateFieldsTest.cs
@@ -162,5 +162,46 @@ namespace Test.Rules.Performance {
 			AssertRuleFailure<GenericUnused<int>> (1);
 			AssertRuleSuccess<GenericUsed<int>> ();
 		}
+
+		class FieldsUsedInNested {
+				private bool field;
+
+				private static string staticField;
+
+				class Nested {
+						public void Foo (FieldsUsedInNested parent)
+						{
+								FieldsUsedInNested.staticField = "bar";
+								parent.field = true;
+						}
+				}
+		}
+
+		[Test]
+		public void FieldsUsedInNestedType ()
+		{
+				AssertRuleSuccess<FieldsUsedInNested> ();
+		}
+		
+		class CompilerGenerated {
+			public string Name { get; set; }
+		}
+		
+		[Test]
+		public void ClassWithCompilerGeneratedFields ()
+		{
+			AssertRuleSuccess<CompilerGenerated> ();
+		}
+		
+		class CompilerGeneratedAndUnused {
+			private int number;
+			public string Name { get; set; }
+		}
+		
+		[Test]
+		public void ClassWithCompilerGeneratedFieldsAndUnusedPrivate ()
+		{
+			AssertRuleFailure<CompilerGeneratedAndUnused> (1);
+		}
 	}
 }