Re: Lua 5.3w2 Test Suite Issues

[Doug Currie <doug.currie@...>]

On Sun, Mar 30, 2014 at 11:54 AM, Doug Currie <doug.currie@gmail.com> wrote:

On Sun, Mar 30, 2014 at 8:55 AM, Paige DePol <lual@serfnet.org> wrote:

sort.lua fails the assertion at line 31:

assert(not pcall(unpack, {}, 0, 2^31-1))

-- also on OSX 10.9.2...

$ lua

Lua 5.2.3  Copyright (C) 1994-2013 Lua.org, PUC-Rio

> unpack {}

> unpack ({}, 0, 2^31-1)

Segmentation fault: 11 

unpack may be fixed in Clang with

//  if (n <= 0 || !lua_checkstack(L, n))  /* n <= 0 means arith. overflow */

  if (__builtin_sadd_overflow(e - i, 1, &n) || !lua_checkstack(L, n))

Too bad there is no portable simple way to do this. In this case, this would also work:

//  n = e - i + 1;  /* number of elements */

//  if (n <= 0 || !lua_checkstack(L, n))  /* n <= 0 means arith. overflow */

  n = e - i;  /* number of elements minus one */

  if (n > (INT_MAX - 1) || !lua_checkstack(L, n+1))  /* n > (INT_MAX - 1) means arith. overflow */

e