Some symbols exported by gcc-4.4.6 would not be exported by gcc-4.7.0.
If the visibility of struct __cook is hidden, the function "myopen" keeps "hidden" too.
[root@djt-17-109-v06 tmp]# cat tvisi.cpp
extern "C" typedef struct __cook cook_t;
extern "C" cook_t* myopen();
struct __attribute__ ((visibility ("hidden"))) __cook {
virtual ~__cook() = 0;
};
//__attribute__ ((visibility ("default")))
cook_t* myopen()
{
return 0;
}
[root@djt-17-109-v06 tmp]# g++ tvisi.cpp -o libxx.so -shared -fPIC && nm -D libxx.so | fgrep myopen
00000000000005cc T myopen
[root@djt-17-109-v06 tmp]# # I can see the symbol myopen be exported by gcc-4.4.6
[root@djt-17-109-v06 tmp]# g++47 tvisi.cpp -o libxx.so -shared -fPIC && nm -D libxx.so | fgrep myopen
[root@djt-17-109-v06 tmp]# # I can not see the symbol myopen be exported by gcc-4.7.0
