Basically I would like to look up a function in a shared object in a platform independent way: I don't want to deal with LoadLibrary/GetProcAddress or dlopen details.
Is there a library that hides the process of looking up a function pointer in shared objects on various operating systems? I would like simply to provide the shared object/dll name and the function name and obtain a C function pointer to invoke that function.
There is no library because using dlsym or GetProcAddress is so simple that it is not worth to be factored out in a separate library. But it is a part of many libraries.
Heres a quick Copy&Paste from the FOX GUI Toolkit:
void* fxdllOpen(const FXchar *dllname){
if(dllname){
#ifndef WIN32
#ifdef HAVE_SHL_LOAD // HP-UX
return shl_load(dllname,BIND_IMMEDIATE|BIND_NONFATAL|DYNAMIC_PATH,0L);
#else
#ifdef DL_LAZY // OpenBSD
return dlopen(dllname,DL_LAZY);
#else // POSIX
return dlopen(dllname,RTLD_NOW|RTLD_GLOBAL);
#endif
#endif
#else // WIN32
return LoadLibraryExA(dllname,NULL,LOAD_WITH_ALTERED_SEARCH_PATH);
#endif
}
return NULL;
}
void fxdllClose(void* dllhandle){
if(dllhandle){
#ifndef WIN32
#ifdef HAVE_SHL_LOAD // HP-UX
shl_unload((shl_t)dllhandle);
#else // POSIX
dlclose(dllhandle);
#endif
#else // WIN32
FreeLibrary((HMODULE)dllhandle);
#endif
}
}
void* fxdllSymbol(void* dllhandle,const FXchar* dllsymbol){
if(dllhandle && dllsymbol){
#ifndef WIN32
#ifdef HAVE_SHL_LOAD // HP-UX
void* address=NULL;
if(shl_findsym((shl_t*)&dllhandle,dllsymbol,TYPE_UNDEFINED,&address)==0) return address;
#else // POSIX
return dlsym(dllhandle,dllsymbol);
#endif
#else // WIN32
return (void*)GetProcAddress((HMODULE)dllhandle,dllsymbol);
#endif
}
return NULL;
}
Take a look at how it was done in boost, interprocess/detail/os_file_functions.hpp. No magic here, #ifdef is needed.
