Function lua_checkstack

depends/lua/src/lapi.c:97–115

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) {