Linking a native msvc dll library to CYGWIN g++ compiler

Linking a native msvc dll library to CYGWIN g++ compiler

[Mümin A.]

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Hi,

I'm facing a problem while linking my native dll library into the g++
compiler.

There is a name mangling problem when calling a msvc function from g++
compiler therefore linker gives an error undefined reference.

Is there any method to directly link and call a function from native dll
library from the cygwin compiler ?



For example, I've a fooCls.h header file for a windows library,  I add link
the fooCls.dll to g++ compiler then,

fooNameSpace::fooConnectionCls instance;
instance.FooTest();

gives a linker error , undefined reference.


Thank you in advance,
Mumin AYDIN

[-- Attachment #2: fooCls.h --]
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#ifndef FOOCLS_H
#define FOOCLS_H

#if defined(_WIN32)
#ifdef DLL_EXPORT
#define _WIN_DLL __declspec(dllexport)
#else
#define _WIN_DLL __declspec(dllimport)
#endif
#else
#define _WIN_DLL
#endif

namespace fooNameSpace
{

    class _WIN_DLL fooConnectionCls
    {
    public:
        void FooTest();
    };

}

#endif // FOOCLS_H

Re: Linking a native msvc dll library to CYGWIN g++ compiler

[Csaba Ráduly]

On 11/07/2023 08:47, Mümin A. via Cygwin wrote:
> Hi,
>
> I'm facing a problem while linking my native dll library into the g++
> compiler.
>
> There is a name mangling problem when calling a msvc function from g++
> compiler therefore linker gives an error undefined reference.
>
> Is there any method to directly link and call a function from native dll
> library from the cygwin compiler ?
>
>
>
> For example, I've a fooCls.h header file for a windows library,  I add link
> the fooCls.dll to g++ compiler then,
>
> fooNameSpace::fooConnectionCls instance;
> instance.FooTest();
>
> gives a linker error , undefined reference.

Hi,

GCC (and most compilers on Unix-like systems, even macOS) use the 
Itanium (IA64) ABI for C++ mangling:

https://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling

MSVC uses a different scheme, so the name of the symbol (as seen by the 
linker) expected by the object file compiled by GCC is different from 
the symbol supplied by the object file compiled with MSVC.

To link object files from GCC and MSVC together, you need to use C 
linkage (extern "C").

Csaba

-- 

Life is complex, with real and imaginary parts.

Re: Linking a native msvc dll library to CYGWIN g++ compiler

[Mümin A.]

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Hi,

reminder..

Mümin A. <muminaydin06@gmail.com>, 11 Tem 2023 Sal, 09:47 tarihinde şunu
yazdı:

>
> Hi,
>
> I'm facing a problem while linking my native dll library into the g++
> compiler.
>
> There is a name mangling problem when calling a msvc function from g++
> compiler therefore linker gives an error undefined reference.
>
> Is there any method to directly link and call a function from native dll
> library from the cygwin compiler ?
>
>
>
> For example, I've a fooCls.h header file for a windows library,  I add
> link the fooCls.dll to g++ compiler then,
>
> fooNameSpace::fooConnectionCls instance;
> instance.FooTest();
>
> gives a linker error , undefined reference.
>
>
> Thank you in advance,
> Mumin AYDIN
>
>
>
>

Re: Linking a native msvc dll library to CYGWIN g++ compiler

[Mark Geisert]

Mümin A. via Cygwin wrote:
> Hi,
> 
> reminder..
> 
> Mümin A. <muminaydin06@gmail.com>, 11 Tem 2023 Sal, 09:47 tarihinde şunu
> yazdı:
> 
>>
>> Hi,
>>
>> I'm facing a problem while linking my native dll library into the g++
>> compiler.
>>
>> There is a name mangling problem when calling a msvc function from g++
>> compiler therefore linker gives an error undefined reference.
>>
>> Is there any method to directly link and call a function from native dll
>> library from the cygwin compiler ?
>>
>>
>>
>> For example, I've a fooCls.h header file for a windows library,  I add
>> link the fooCls.dll to g++ compiler then,
>>
>> fooNameSpace::fooConnectionCls instance;
>> instance.FooTest();
>>
>> gives a linker error , undefined reference.
>>
>>
>> Thank you in advance,
>> Mumin AYDI

Did you see Csaba's reply to your initial email?  Check the mail archives.
Does FAQ 6.36 describe your situation?

See the Cygwin home page https://cygwin.com for pointers to those resources.

..mark