C#: Make Nullable type a ConstructedType and VoidType a ValueType.

csharp/ql/lib/semmle/code/csharp/Generics.qll

@@ -406,17 +406,17 @@ class ConstructedType extends ValueOrRefType, ConstructedGeneric {
 
   override UnboundGenericType getUnboundGeneric() { constructed_generic(this, getTypeRef(result)) }
 
-  final override Type getChild(int n) { result = this.getTypeArgument(n) }
+  override Type getChild(int n) { result = this.getTypeArgument(n) }
 
-  final override string toStringWithTypes() {
+  override string toStringWithTypes() {
     result = this.getUndecoratedName() + "<" + getTypeArgumentsToString(this) + ">"
   }
 
-  final override string getName() {
+  override string getName() {
     result = this.getUndecoratedName() + "<" + getTypeArgumentsNames(this) + ">"
   }
 
-  final override predicate hasQualifiedName(string qualifier, string name) {
+  override predicate hasQualifiedName(string qualifier, string name) {
     exists(string name0 | name = name0 + "<" + getTypeArgumentsQualifiedNames(this) + ">" |
       exists(string enclosing |
         this.getDeclaringType().hasQualifiedName(qualifier, enclosing) and

csharp/ql/lib/semmle/code/csharp/Type.qll

@@ -401,10 +401,20 @@ class NonNestedType extends ValueOrRefType {
   NonNestedType() { exists(Namespace n | parent_namespace(this, n)) }
 }
 
+/**
+ * A value type.
+ *
+ * Either a simple type (`SimpleType`), an `enum` (`Enum`), a `struct` (`Struct`),
+ * or a nullable type (`NullableType`).
+ */
+class ValueType extends ValueOrRefType, @value_type {
+  override predicate isValueType() { any() }
+}
+
 /**
  * The `void` type.
  */
-class VoidType extends DotNet::ValueOrRefType, Type, @void_type {
+class VoidType extends ValueType, Type, @void_type {
   override predicate hasQualifiedName(string qualifier, string name) {
     qualifier = "System" and
     name = "Void"
@@ -419,16 +429,6 @@ class VoidType extends DotNet::ValueOrRefType, Type, @void_type {
   override string getAPrimaryQlClass() { result = "VoidType" }
 }
 
-/**
- * A value type.
- *
- * Either a simple type (`SimpleType`), an `enum` (`Enum`), a `struct` (`Struct`),
- * or a nullable type (`NullableType`).
- */
-class ValueType extends ValueOrRefType, @value_type {
-  override predicate isValueType() { any() }
-}
-
 /**
  * A simple type. Simple types in C# are predefined `struct` types.
  * Here, however, they are not modeled as such, and we reserve the
@@ -989,7 +989,7 @@ class NullType extends RefType, @null_type {
 /**
  * A nullable type, for example `int?`.
  */
-class NullableType extends ValueType, DotNet::ConstructedGeneric, @nullable_type {
+class NullableType extends ValueType, ConstructedType, @nullable_type {
   /**
    * Gets the underlying value type of this nullable type.
    * For example `int` in `int?`.

csharp/ql/lib/semmlecode.csharp.dbscheme

@@ -456,7 +456,7 @@ case @type.kind of
 @unsigned_integral_type = @byte_type  | @ushort_type | @uint_type | @ulong_type;
 @floating_point_type = @float_type | @double_type;
 @value_type = @simple_type | @enum_type | @struct_type | @nullable_type | @int_ptr_type
-            | @uint_ptr_type | @tuple_type;
+            | @uint_ptr_type | @tuple_type | @void_type;
 @ref_type = @class_type | @interface_type | @array_type | @delegate_type | @null_type
           | @dynamic_type;
 @value_or_ref_type = @value_type | @ref_type;
@@ -2037,7 +2037,7 @@ cil_attribute_positional_argument(
 @dotnet_type = @type | @cil_type;
 @dotnet_call = @call | @cil_call_any;
 @dotnet_throw = @throw_element | @cil_throw_any;
-@dotnet_valueorreftype = @cil_valueorreftype | @value_or_ref_type | @cil_array_type | @void_type;
+@dotnet_valueorreftype = @cil_valueorreftype | @value_or_ref_type | @cil_array_type;
 @dotnet_typeparameter = @type_parameter | @cil_typeparameter;
 @dotnet_array_type = @array_type | @cil_array_type;
 @dotnet_pointer_type = @pointer_type | @cil_pointer_type;