Re: [Swig-user] Swig Java compability between __declspec(dllexport) and virtual default destructor

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

On 23/06/11 13:44, Yu QIN wrote:
>
> Dear all
>
> I want to convert a program in C++ into Java via SWIG, but there is a
> problem with the virtual default destructor.
>
> //////////////////////example.h/////////////////////
> _________________________________________________________________________
> #ifdef EXAMPLE_SDK
> #define EXAMPLE_API __declspec(dllexport)
> #else
> #define EXAMPLE_API __declspec(dllimport)
> #endif
>
> class MORPHO_API EXAMPLE_Device
> {
> 	public:
> 		int OpenDevice (
> 					int number
> 					);
>
> 		int CloseDevice (void);
> 		virtual ~EXAMPLE_Device ();
> };
> _____________________________________________________________________________
> and in the file .i
> ///////////////example.i/////////////////////
> ________________________________________________________________________
> %module Example
> %include<windows.i>  //I have to add it in order to convert
> __declspec(dllimport)
>
> %{	
> 	#include "example.h";
> %}	
> %include "example.h";
> ______________________________________________________________________________
>
> When I generated the wrapper, there is an error about the virtual default
> destructor
> no resolved extern symbol "__declespec(dllimport) const EXAMPLE_Device :: "
> .........  in the function
> "public: virtual__thiscall EXAMPLE_Device::~EXAMPLE_Device(void)"
>
> If I remove virtual ~EXAMPLE_Device ();, the program will work
> or if I remove MORPHO_API and keep virtual ~EXAMPLE_Device ();, the program
> will also work
>
> Does someone have an idea how to resolve this kind of problem?
> (maybe I have to add some specified options in the file .i??)
>

The author of EXAMPLE_Device must provide a body for the destructor 
which you must link against. This is extremely basic C++ knowledge you 
need to master.

William