Re: [Swig-user] Bug with directors?

[William S F. <ws...@fu...>]

On 27/01/12 22:34, Bonifacio Costiniano wrote:
> Hello,
>
> I believe I'm running into a similar problem from this post, but I'm not
> sure how to reply to this message archive as I don't have the original
> email:
> http://sourceforge.net/mailarchive/message.php?msg_id=28193033
>
> I can reproduce this crash with the following example.
>
> * Reproduced on swig 1.3.40 and 2.0.4
>
> ==[Test.h]================================================
> class Director1
> {
> public:
> Director1() { base_var = 1; }
> virtual ~Director1() {}
>
> virtual void unused() {};
> protected:
> int base_var;
> };
>
> class Director2 : public Director1
> {
> public:
> Director2() { base_var = 3; }
> virtual ~Director2() {}
> };
>
> ==[test.i]=================================================
> %module(directors="1", allprotected="1") Test
>
> %{
> #include "..\swigbuild\Test.h"
> %}
>
> %feature("director") Director1;
> %feature("director") Director2;
>
> %include "Test.h"
>
> ==[Program.cs]=============================================
> class C : Director2
> {
> public C() { }
> public void test()
> {
> int a = base_var;  // exception triggered here
> Console.WriteLine(a);
> }
> }
>
> class Program
> {
> static void Main(string[] args)
> {
> C c = new C();
> c.test();
> }
> }
>
> ==[test_wrap.h (snippets)]=====================================
> class SwigDirector_Director1 : public Director1, public Swig::Director {
>
> public:
>      SwigDirector_Director1();
>      virtual ~SwigDirector_Director1();
> ...
> class SwigDirector_Director2 : public Director2, public Swig::Director {
>
> public:
>      SwigDirector_Director2();
>
> ==[test_wrap.cxx (snippet)]===================================
> SWIGEXPORT int SWIGSTDCALL CSharp_Director1_base_var_get(void * jarg1) {
>    int jresult ;
>    Director1 *arg1 = (Director1 *) 0 ;
>    SwigDirector_Director1 *darg = 0;
>    int result;
>    arg1 = (Director1 *)jarg1;
>    darg = dynamic_cast<SwigDirector_Director1 *>(arg1);  // This cast fails
>    result = (int) (darg->base_var);
>    jresult = result;
>    return jresult;
> }
>
> jarg1 is of type SwigDirector_Director2, so the above dynamic cast will
> fail.
>
> Is there another option I need to specify?

I think this is a known bug and I can't think of any workaround atm. 
Sorry :(

William