new macro 'cast_func' adds '__extension__' (in gnu compilers) when

converting void* to function, to avoid warnings
This commit is contained in:
Roberto Ierusalimschy 2015-01-05 11:51:39 -02:00
parent 3317f5c6d9
commit 0adfa773b9

View File

@ -1,5 +1,5 @@
/*
** $Id: loadlib.c,v 1.122 2014/11/10 14:28:31 roberto Exp roberto $
** $Id: loadlib.c,v 1.123 2014/11/12 13:31:51 roberto Exp roberto $
** Dynamic library loader for Lua
** See Copyright Notice in lua.h
**
@ -135,6 +135,18 @@ static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym);
#include <dlfcn.h>
/*
** Macro to covert pointer to void* to pointer to function. This cast
** is undefined according to ISO C, but POSIX assumes that it must work.
** (The '__extension__' in gnu compilers is only to avoid warnings.)
*/
#if defined(__GNUC__)
#define cast_func(p) (__extension__ (lua_CFunction)(p))
#else
#define cast_func(p) ((lua_CFunction)(p))
#endif
static void lsys_unloadlib (void *lib) {
dlclose(lib);
}
@ -148,7 +160,7 @@ static void *lsys_load (lua_State *L, const char *path, int seeglb) {
static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
lua_CFunction f = (lua_CFunction)dlsym(lib, sym);
lua_CFunction f = cast_func(dlsym(lib, sym));
if (f == NULL) lua_pushstring(L, dlerror());
return f;
}