Hi Paul,

In December 2023, we had a discussion [1] regarding expressions like
  NULL + integer
which are undefined behaviour in ISO C (at least since ISO C 99;
see ISO C 23 ยง 6.5.7.(9)).

Meanwhile the situation has cleared up:
  * When the integer summand is zero, the expression is now valid,
    per ISO C N3322, which has been approved by WG 14.
  * When the integer summand is non-zero, both GCC and clang
    exploit the fact that this is undefined behaviour.
    GCC:   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118779>
    clang: <https://sourceware.org/bugzilla/show_bug.cgi?id=32393#c3>

I'll continue to use the patch from [2] as long as necessary for the
clang sanitizers (in the CI); then we can drop it.

Bruno

[1] https://lists.gnu.org/archive/html/bug-gnulib/2023-12/threads.html
[2] https://lists.gnu.org/archive/html/bug-gnulib/2023-12/msg00055.html




Reply via email to