Re: multiple definition of `__' ???

From:

mike <mike@netadv.net>

Newsgroups:

comp.lang.c++

Date:

Sat, 26 Jan 2008 12:13:42 -0800 (PST)

Message-ID:

<03551675-9418-4de9-867b-0fca914129c4@q77g2000hsh.googlegroups.com>

On Jan 26, 12:10 pm, Rolf Magnus <ramag...@t-online.de> wrote:

mike wrote:

I am writing some c++ code and have been stuck in the linking
process. I get an error of multiple definition of `__' when linking.
I would post this in the gcc usenet, but I think it is more of a c++
syntax problem than a linker problem. Here is my setup, I have a
class which is divided into a header and a source file, the source
file includes the header for the class (like it should). I then have
another source file that includes my main function. This source file
also includes the header for the class. The header file has the
proper
#ifndef SOMETHING_H
#define SOMETHING_H
............
#endif

but when I link, I get the error:
obj/something.o:(.bss+0x0): multiple definition of `__'
obj/main.o:(.bss+0x0): first defined here

if I take out the include of "something.h" in my main.cpp, and any
class instances, then it all links just fine.

Any ideas what I am missing?

Not without seeing more of your code. In the three lines you provided and in
your description, there is no error. Post a minimal, but complete program
that shows the error.

Well, I was hoping I could get it fixed without having to post too
much code, but here goes:

test0.cpp******************************
#include "rover_server.h"

#include <fcntl.h>
#include <cerrno>
#include <sys/socket.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <map>

static void init_sockaddr(const char * addr, uint16_t port, sockaddr &
sa) {
     sockaddr_in & ret = (sockaddr_in&) sa;
     ret.sin_family = AF_INET;
     ret.sin_port = htons(port);
     if (!inet_aton(addr, &ret.sin_addr))
         throw "error in init_sockaddr";

     memset(ret.sin_zero, 0, sizeof(ret.sin_zero));
}

int main(int argc, char* argv[]) {
    // Set up the map for the backbones
    std::map<int, int> backbones0;

    // Set up the two backbones.
    int backbone0 = socket(AF_INET, SOCK_DGRAM, 0);
    fcntl(backbone0, F_SETFL, O_NONBLOCK);
    sockaddr backbone1_addr;
    init_sockaddr("0.0.0.0", 5112, backbone1_addr);
    connect(backbone0, &backbone1_addr, sizeof(backbone1_addr));
    backbones0[1] = backbone0;

    // Setup the two server sockets
    int server0 = socket(AF_INET, SOCK_STREAM, 0);
    fcntl(server0, F_SETFL, O_NONBLOCK);
    sockaddr server0_addr;
    init_sockaddr("0.0.0.0", 5113, server0_addr);
    bind(server0, &server0_addr, sizeof(server0_addr));
listen(server0, 10);
    RoverServer rover0 = RoverServer(server0, backbones0, 0);
}

rover_server.h ***********************************
#ifndef ROVER_SERVER_H
#define ROVER_SERVER_H
#include "ev_cpp.h"
#include "rover_message.h"

#include <fcntl.h>
#include <unistd.h>
#include <cerrno>
#include <sys/socket.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <map>

typedef int socketfd;

class RoverServer {
private:
    std::map<int, socketfd> backbones;
    std::map<int, socketfd> clients;
    int id;

public:
    // Default constructor
    RoverServer(socketfd serverfd, std::map<int, socketfd> b, int i);

    // Callback Methods for EV
    void server_cb(ev::io& watcher, int revents);
    void client_cb(ev::io& watcher, int revents);
    void backbone_cb(ev::io& watcher, int revents);
};
#endif

rover_server.cpp (not the whole
file)***********************************
#include "rover_server.h"

// Constructor
RoverServer::RoverServer(socketfd serverfd, std::map<int, socketfd> b,
int i) : backbones(b), id(i) {
    // Setup the listening socket
    ev_default_loop(0);

    // Setup the main watcher for libev
    ev::io server_watcher;
    server_watcher.set<RoverServer, &RoverServer::server_cb>(this);
    server_watcher.set(serverfd, EV_READ);
..
..
..
..

Thanks for the help, hopefully this will make it easier to help.