Function lua_getmetatable

third-party/lua-5.3.5/src/lapi.c:697–721

LUA_API int lua_getmetatable (lua_State *L, int objindex) {
  const TValue *obj;
  Table *mt;
  int res = 0;
  lua_lock(L);
  obj = index2addr(L, objindex);
  switch (ttnov(obj)) {
    case LUA_TTABLE:
      mt = hvalue(obj)->metatable;
      break;
    case LUA_TUSERDATA:
      mt = uvalue(obj)->metatable;
      break;
    default:
      mt = G(L)->mt[ttnov(obj)];
      break;
  }
  if (mt != NULL) {
    sethvalue(L, L->top, mt);
    api_incr_top(L);
    res = 1;
  }
  lua_unlock(L);
  return res;
}


LUA_API int lua_getuservalue (lua_State *L, int idx) {