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GCC 4.5.2 Problems with linkers Problem when using Exceptions (C ++)

I am trying to write a web server. It works fine with Windows as far as I know. But I want to make it Unix compatible. And I think there is a problem with the inheritance of the exception class. For a better understanding, only the important parts:

server.cpp

#include <exception>
#include <stdexcept>

#ifdef __unix__
    #include "UnixSocket.h"
#elif __WIN32__ || _MSC_VER
    #include "WinSocket.h"
#endif

#include "HTTPParser.h"

int main(void) {
    try {
        socket->socketInit(PORT);
    }
    catch (exception &e) {
        cout << endl << "Exception: " << e.what() << endl;
        socket->cleanAll();
    }
return 0
}

NetInterface.h

class NetInterface : public exception {

private:

public:
    virtual void socketInit(const char *port) = 0;
    virtual void cleanAll(void) = 0;
    virtual void cleanPersCon(void) = 0;
    virtual char *akzeptieren(void) = 0;
    virtual void empfangen(void) = 0;
    virtual void senden(void) = 0;
    virtual void *get_in_addr(struct sockaddr *sa) = 0;
    virtual string getIncoming(void) = 0;
    virtual void setOutcoming(string s) = 0;

    virtual ~NetInterface() throw() {};

};

UnixSocket.h

class UnixSocket : virtual public NetInterface { 
private: 
    [...]
public:
    UnixSocket(void);
//kill socket connections
    void cleanAll(void);
    void cleanPersCon(void);
//SysCalls
    void socketInit(const char *port);
    char *akzeptieren(void);
    void empfangen(void);
    void senden(void);
//Getter and Setter
    string getIncoming(void);
    void setOutcoming(string s);

    virtual ~UnixSocket() throw() {};
};

HTTPParser.h

class HTTPParser : public exception {
private:
    [...]

public:
    HTTPParser(NetInterface *_socket, string _path);
    void parsePacket(void);

    virtual ~HTTPParser() throw() {};
};

You can briefly describe class declarations here. But now gcc is telling me something like this:

/tmp/cc8DNmKI.o:(.rodata._ZTV10HTTPParser[vtable for HTTPParser]+0x10): undefined reference to `std::exception::what() const'
/tmp/cc8DNmKI.o:(.rodata._ZTV10UnixSocket[vtable for UnixSocket]+0x14): undefined reference to `std::exception::what() const'
/tmp/cc8DNmKI.o:(.rodata._ZTV10UnixSocket[vtable for UnixSocket]+0x78): undefined reference to `std::exception::what() const'
/tmp/cc8DNmKI.o:(.rodata._ZTV12NetInterface[vtable for NetInterface]+0x10): undefined reference to `std::exception::what() const'
/tmp/cc8DNmKI.o:(.rodata._ZTV12NetInterface[vtable for NetInterface]+0x14): undefined reference to `__cxa_pure_virtual'
/tmp/cc8DNmKI.o:(.rodata._ZTV12NetInterface[vtable for NetInterface]+0x18): undefined reference to `__cxa_pure_virtual'
/tmp/cc8DNmKI.o:(.rodata._ZTV12NetInterface[vtable for NetInterface]+0x1c): undefined reference to `__cxa_pure_virtual'
/tmp/cc8DNmKI.o:(.rodata._ZTV12NetInterface[vtable for NetInterface]+0x20): undefined reference to `__cxa_pure_virtual'
/tmp/cc8DNmKI.o:(.rodata._ZTV12NetInterface[vtable for NetInterface]+0x24): undefined reference to `__cxa_pure_virtual'
/tmp/cc8DNmKI.o:(.rodata._ZTV12NetInterface[vtable for NetInterface]+0x28): more undefined references to `__cxa_pure_virtual' follow
/tmp/cc8DNmKI.o:(.rodata._ZTVSt16invalid_argument[vtable for std::invalid_argument]+0x10): undefined reference to `std::logic_error::what() const'
/tmp/cc8DNmKI.o:(.rodata._ZTVSt12domain_error[vtable for std::domain_error]+0x10): undefined reference to `std::logic_error::what() const'
/tmp/cc8DNmKI.o:(.rodata._ZTI10HTTPParser[typeinfo for HTTPParser]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/tmp/cc8DNmKI.o:(.rodata._ZTI10HTTPParser[typeinfo for HTTPParser]+0x8): undefined reference to `typeinfo for std::exception'
/tmp/cc8DNmKI.o:(.rodata._ZTI10UnixSocket[typeinfo for UnixSocket]+0x0): undefined reference to `vtable for __cxxabiv1::__vmi_class_type_info'
/tmp/cc8DNmKI.o:(.rodata._ZTI10UnixSocket[typeinfo for UnixSocket]+0x18): undefined reference to `typeinfo for std::exception'
/tmp/cc8DNmKI.o:(.rodata._ZTI12NetInterface[typeinfo for NetInterface]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/tmp/cc8DNmKI.o:(.rodata._ZTI12NetInterface[typeinfo for NetInterface]+0x8): undefined reference to `typeinfo for std::exception'
/tmp/cc8DNmKI.o:(.rodata._ZTISt16invalid_argument[typeinfo for std::invalid_argument]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/tmp/cc8DNmKI.o:(.rodata._ZTISt16invalid_argument[typeinfo for std::invalid_argument]+0x8): undefined reference to `typeinfo for std::logic_error'
/tmp/cc8DNmKI.o:(.rodata._ZTISt12domain_error[typeinfo for std::domain_error]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/tmp/cc8DNmKI.o:(.rodata._ZTISt12domain_error[typeinfo for std::domain_error]+0x8): undefined reference to `typeinfo for std::logic_error'
/tmp/cc8DNmKI.o:(.eh_frame+0xeb): undefined reference to `__gxx_personality_v0'
collect2: ld returned 1 exit status

and even more....

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2 answers


undefined reference to __gxx_personality_v0

From the linker post , it looks like you are linking with gcc

. You need to link your C ++ apps with g++

. Or link from gcc

and add -lstdc++

to linker command line.



+6


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You don't show the relevant code and compiler call, but you know you std::exception

have an unimplemented virtual member function what()

that you expect to override, so don't cast naked std::exception

if you want to call what()

.



Any of the derived, special exceptions in <stdexcept>

will implement what()

and allow you to persist the message when the exception object is created.

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