Singleton instantiated more than once with -fvisibility=hidden

[Filipe Sousa <filipe@xxxxxx>]

I have 3 files, the library (singleton.h/.cc) and the main program (main.cc)

-- singleton.h --
#pragma once

#include <iostream>

class singleton {
public:
    singleton() { std::cout << __PRETTY_FUNCTION__ << std::endl; }
    static singleton* instance() {
        static singleton s;
        return &s;
    }
};

-- singleton.cc --
#include "singleton.h"

void foo()
{
    singleton::instance();
}

-- main.cc --
#include "singleton.h"

int main() {
    foo();
    singleton::instance();
    return 0;
}

c++ -g -fPIC -Wall -c singleton.cc -o singleton.o
c++ -fPIC -shared -Wl,-soname,libsingleton.so -o libsingleton.so singleton.o
c++ -Wall -g -c main.cc -o main.o
c++ -g -fPIC main.o -o main -rdynamic -L${PWD} -lsingleton -Wl,-rpath,${PWD}

fsousa@neptuno ~/tmp/vis $ ./main 
singleton::singleton()

Here, the singleton is only instanciated once as expected, but if I add 
visibility support to the code

-- singleton.h --
#pragma once

#include <iostream>

class __attribute__ ((visibility("default"))) singleton {
public:
    singleton() { std::cout << __PRETTY_FUNCTION__ << std::endl; }
    static singleton* instance() {
        static singleton s;
        return &s;
    }
};

__attribute__ ((visibility("default"))) void foo();

c++ -g -fPIC -Wall -fvisibility-inlines-hidden -fvisibility=hidden -c 
singleton.cc -o singleton.o
c++ -fPIC -fvisibility-inlines-hidden -fvisibility=hidden -shared 
-Wl,-soname,libsingleton.so -o libsingleton.so singleton.o
c++ -Wall -g -c main.cc -o main.o
c++ -g -fPIC main.o -o main -rdynamic -L${PWD} -lsingleton -Wl,-rpath,${PWD}

fsousa@neptuno ~/tmp/vis $ ./main 
singleton::singleton()
singleton::singleton()

I have more than one instance. Am I doing something wrong?

gcc (GCC) 4.0.1-beta20050526 (Gentoo 4.0.1_beta20050526)

-- Filipe Sousa

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