Extern "C" does not disable name manipulation

I am trying to use a C ++ library in a C environment while implementing a wrapper. I noticed that you need to declare functions as extern "C" in your header file. However, when I try to link my dynamic library, the mangling name does not get cut off, which results in undefined characters when I try to use my wrapper.

Here is the current header of my shell, SbeOtfDecoder.h:

#ifndef ITF_SBEOTFDECODER_H_
#define ITF_SBEOTFDECODER_H_                                                            


// WARNING! In a C++ wrapper for C, any exception thrown by C++ code HAS TO BE CATCHED!
// Otherwise, it is "undefined behavior".

#ifdef __cplusplus                                                                      
extern "C" {
#endif                                                                                  
///Create a new SbeOtfDecoder class instance, casted as void * for C code.
void *SbeOtfDecoder_new_with_file(char *filename);

///Destroy SbeOtfDecoder class instance.
void SbeOtfDecoder_free(void *self);
#ifdef __cpluscplus
} //extern "C"
#endif

#endif /* ITF_SBEOTFDECODER_H_ */

      

        
        
        
      

    

And the corresponding functions in SbeOtfDecoder.cpp:

class SbeOtfDecoder
{
public:
    SbeOtfDecoder(char *filename);
    ~SbeOtfDecoder();
};

SbeOtfDecoder::SbeOtfDecoder(char *filename)
{
}

SbeOtfDecoder::~SbeOtfDecoder()
{
}

void *SbeOtfDecoder_new_with_file(char *filename)
{
    return new SbeOtfDecoder(filename);
}

void SbeOtfDecoder_free(void *self)
{
    delete static_cast<SbeOtfDecoder*>(self);
}

      

        
        
        
      

    

Then there is a connection (jokingly):

g++ -shared ../tmpfs/v7-flux/env/squeeze-32/DEBUG/./libs/itf_sbedecoder/src/Ir.oo ../tmpfs/v7-flux/env/squeeze-32/DEBUG/./libs/itf_sbedecoder/src/Listener.oo ../tmpfs/v7-flux/env/squeeze-32/DEBUG/./libs/itf_sbedecoder/src/SbeOtfDecoder.oo -L../tmpfs/lib   -lstdc++ -o ../tmpfs/lib/libitfsbedecoder.so

      

        
        
        
      

    

However, the symbols are still garbled in the output library:

nm ../tmpfs/lib/libitfsbedecoder.so | grep SbeOtf
0001f460 t _GLOBAL__I_SbeOtfDecoder.cpp
0001f3d8 T _Z18SbeOtfDecoder_freePv
0001f37f T _Z27SbeOtfDecoder_new_with_filePc
0001f36e T _ZN13SbeOtfDecoderC1EPc
0001f368 T _ZN13SbeOtfDecoderC2EPc
0001f37a T _ZN13SbeOtfDecoderD1Ev
0001f374 T _ZN13SbeOtfDecoderD2Ev

      

        
        
        
      

    

These symbols cannot be used by the rest of the C framework, I am currently failing on unit test with this error:

~/workspace/v7-flux/build/cunit-32: symbol lookup error: ../tmpfs/v7-flux/env/squeeze-32/DEBUG/cunit/./libs/itf_sbedecoder/cunit//libtest_SbeOtfDecoder_test.so: undefined symbol: SbeOtfDecoder_new_with_file

      

        
        
        
      

    

I have no idea what I am doing wrong. If you need to know more about some of the compilation steps, feel free to ask. I didn't invest more, as almost the entire compilation process is "hidden" in this structure.