Function luaD_pcall

3rd/lua-5.4.3/src/ldo.c:885–902

** Call the C function 'func' in protected mode, restoring basic ** thread information ('allowhook', etc.) and in particular ** its stack level in case of errors. */

** its stack level in case of errors.
*/
int luaD_pcall (lua_State *L, Pfunc func, void *u,
                ptrdiff_t old_top, ptrdiff_t ef) {
  int status;
  CallInfo *old_ci = L->ci;
  lu_byte old_allowhooks = L->allowhook;
  ptrdiff_t old_errfunc = L->errfunc;
  L->errfunc = ef;
  status = luaD_rawrunprotected(L, func, u);
  if (l_unlikely(status != LUA_OK)) {  /* an error occurred? */
    L->ci = old_ci;
    L->allowhook = old_allowhooks;
    status = luaD_closeprotected(L, old_top, status);
    luaD_seterrorobj(L, status, restorestack(L, old_top));
    luaD_shrinkstack(L);   /* restore stack size in case of overflow */
  }
  L->errfunc = old_errfunc;
  return status;
}