On Thu, Aug 03, 2023 at 13:33:27 +0000, Rin Okuyama wrote:
> -Wuse-after-free for GCC 12 is premature. It fires on a common idiom:
>
> newbuf = realloc(buf, size);
> p = newbuf + (p - buf);
>
> Let shut this up for GCC 12 (with hoping it gets improved for 13!).
C99 says
J.2 Undefined behavior
[#1] The behavior is undefined in the following
circumstances:
[...]
-- The value of a pointer to an object whose lifetime has
ended is used (6.2.4).
Yes, for the "obvious" implementation of pointers as addresses the
above idiom happens to work, but it doesn't make that idiom any less
UB.
-uwe
