Function lua_checkstack

libraries/lua-gph/lib/src/lapi.cpp:105–125

}

LUA_API int lua_checkstack(lua_State *L, int n)
{
  int res;
  CallInfo *ci = L->ci;
  lua_lock(L);
  api_check(L, n >= 0, "negative 'n'");
  if (L->stack_last - L->top > n) /* stack large enough? */
    res = 1;                      /* yes; check is OK */
  else
  { /* no; need to grow stack */
    int inuse = cast_int(L->top - L->stack) + EXTRA_STACK;
    if (inuse > LUAI_MAXSTACK - n) /* can grow without overflow? */
      res = 0;                     /* no */
    else                           /* try to grow stack */
      res = (luaD_rawrunprotected(L, &growstack, &n) == LUA_OK);
  }
  if (res && ci->top < L->top + n)
    ci->top = L->top + n; /* adjust frame top */
  lua_unlock(L);
  return res;
}

LUA_API void lua_xmove(lua_State *from, lua_State *to, int n)
{