Generate valid C# for default args: typedefed refs to enums assigned empty ctors

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

Author: ddobrev

src/Generator/Passes/ExpressionHelper.cs

@@ -19,7 +19,8 @@ internal class ExpressionHelper
         private static readonly Regex regexDoubleColon = new Regex(@"\w+::", RegexOptions.Compiled);
         private static readonly Regex regexName = new Regex(@"(\w+)", RegexOptions.Compiled);
 
-        public static bool? PrintExpression(BindingContext context, Function function, Type type, ExpressionObsolete expression, bool allowDefaultLiteral, ref string result)
+        public static bool? PrintExpression(BindingContext context, Function function, Type type,
+            ExpressionObsolete expression, bool allowDefaultLiteral, ref string result)
         {
             var desugared = type.Desugar();
 
@@ -226,7 +227,7 @@ private static bool CheckForDefaultPointer(BindingContext context, Type desugare
         private static bool? CheckForDefaultConstruct(BindingContext context, Type desugared, ExpressionObsolete expression,
             ref string result)
         {
-            var type = desugared.GetFinalPointee() ?? desugared;
+            var type = (desugared.GetFinalPointee() ?? desugared).Desugar();
 
             Class decl;
             if (!type.TryGetClass(out decl))

tests/CSharp/CSharp.Tests.cs

@@ -318,6 +318,7 @@ public void TestDefaultArguments()
             Assert.That(methodsWithDefaultValues.DefaultMappedToEnum(), Is.EqualTo(Flags.Flag3));
             methodsWithDefaultValues.DefaultMappedToZeroEnum();
             methodsWithDefaultValues.DefaultMappedToEnumAssignedWithCtor();
+            methodsWithDefaultValues.DefaultTypedefMappedToEnumRefAssignedWithCtor();
             methodsWithDefaultValues.DefaultZeroMappedToEnumAssignedWithCtor();
             Assert.That(methodsWithDefaultValues.DefaultImplicitCtorInt().Priv, Is.EqualTo(0));
             methodsWithDefaultValues.DefaultImplicitCtorChar();

tests/CSharp/CSharp.cpp

@@ -713,6 +713,10 @@ void MethodsWithDefaultValues::defaultMappedToEnumAssignedWithCtor(QFlags<Flags>
 {
 }
 
+void MethodsWithDefaultValues::defaultTypedefMappedToEnumRefAssignedWithCtor(const TypedefedFlags& qFlags)
+{
+}
+
 void MethodsWithDefaultValues::defaultZeroMappedToEnumAssignedWithCtor(DefaultZeroMappedToEnum defaultZeroMappedToEnum)
 {
 }

tests/CSharp/CSharp.h

@@ -452,6 +452,8 @@ class DLL_API MethodsWithDefaultValues : public Quux
     QFlags<Flags> defaultMappedToEnum(const QFlags<Flags>& qFlags = Flags::Flag3);
     void defaultMappedToZeroEnum(QFlags<Flags> qFlags = 0);
     void defaultMappedToEnumAssignedWithCtor(QFlags<Flags> qFlags = QFlags<Flags>());
+    typedef QFlags<Flags> TypedefedFlags;
+    void defaultTypedefMappedToEnumRefAssignedWithCtor(const TypedefedFlags& qFlags = TypedefedFlags());
     void defaultZeroMappedToEnumAssignedWithCtor(DefaultZeroMappedToEnum defaultZeroMappedToEnum = DefaultZeroMappedToEnum());
     Quux defaultImplicitCtorInt(Quux arg = 0);
     void defaultImplicitCtorChar(Quux arg = 'a');

tests/CSharp/CSharpTemplates.h

@@ -698,10 +698,11 @@ template <typename T>
 class QFlags
 {
     typedef int Int;
-    typedef int (*Zero);
+    struct Private;
+    typedef int (Private::*Zero);
 public:
     QFlags(T t);
-    QFlags(Zero = 0);
+    QFlags(Zero = nullptr);
     operator Int();
 private:
     int flag;