Check for function parameters in mixins (#484)

* Check for function parameters in mixins

* Don't trigger errors on uncertain mesages

src/dscanner/analysis/unused.d

@@ -234,12 +234,17 @@ class UnusedVariableCheck : BaseAnalyzer
 			{
 				foreach (part; matchAll(primary.primary.text, re))
 				{
-					immutable size_t treeIndex = tree.length - 1;
+					void checkTree(in size_t treeIndex)
+					{
 						auto uu = UnUsed(part.hit);
 						auto r = tree[treeIndex].equalRange(&uu);
 						if (!r.empty)
 							r.front.uncertain = true;
 					}
+					checkTree(tree.length - 1);
+					if (tree.length >= 2)
+						checkTree(tree.length - 2);
+				}
 			}
 		}
 		primary.accept(this);
@@ -407,6 +412,8 @@ private:
 		{
 			if (!uu.isRef && tree.length > 1)
 			{
+			    if (uu.uncertain)
+			        continue;
 				immutable string certainty = uu.uncertain ? " might not be used."
 					: " is never used.";
 				immutable string errorMessage = (uu.isParameter ? "Parameter " : "Variable ")
@@ -527,6 +534,11 @@ private:
 		cb2(3);
 	}
 	
+	bool hasDittos(int decl)
+	{
+		mixin("decl++;");
+	}
+
 	}c, sac);
 	stderr.writeln("Unittest for UnusedVariableCheck passed.");
 }