How to get original parameter type and not an expanded typedef

[MarcelVersteeg]

Let's say I have the following code

template<class T>
class MyTemplateClass
{
    ....
};

typedef unsigned int MyInt;
typedef ::MyTemplateClass<char> MyCharClass;
typedef ::MyTemplateClass<::MyInt> MyMyIntClass;

class MyTestClass
{
    void TestMethod1(::MyInt param);
    void TestMethod2(::MyCharClass& param);
    void TestMethod3(::MyMyIntClass& param);
};

When I parse this, I get the following parameter information for the methods:
TestMethod1 -> param type is unsigned int
TestMethod2 -> param type is MyTemplateClass (wihtout the template arguments!)
TestMethod3 -> param type is MyTemplateClass (wihtout the template arguments!)

When I look at the C interface of clang, it seems that this is solved by using the canonical types, where the original (non-expanded type) is the actual type and holds a pointer to the underlying expanded type (not tested as I am writing C# code using this library).
However using this library, I am not able to get the original type as it is declared in the method signature.

I would like to know the original parameter type as it is written in the code and not the already expanded typedef. My parse configuration is as follows:

new CppParserOptions
{
    AutoSquashTypedef = false,
    ParseAsCpp = true,
    ParseAttributes = false,
    ParseComments = false,
    ParseMacros = true,
    ParseSystemIncludes = false,
    TargetCpu = CppTargetCpu.X86,
    TargetSystem = @"windows",
    TargetVendor = @"pc"
};

[xoofx]

This library was not meant to support C++ and templates, also because libclang is sometimes not exposing everything, which is bringing more complications because we need to re-parse things CppAst.
But PR welcome if you find a way to expose this properly.