Re: [PATCH libatomic/arm] avoid warning on constant addresses (PR 101379)

[Christophe Lyon <christophe.lyon.oss@gmail.com>]

Hi,


On Sat, Jul 10, 2021 at 1:11 AM Martin Sebor via Gcc-patches <
gcc-patches@gcc.gnu.org> wrote:

> The attached tweak avoids the new -Warray-bounds instances when
> building libatomic for arm. Christophe confirms it resolves
> the problem (thank you!)
>
> As we have discussed, the main goal of this class of warnings
> is to detect accesses at addresses derived from null pointers
> (e.g., to struct members or array elements at a nonzero offset).
> Diagnosing accesses at hardcoded addresses is incidental because
> at the stage they are detected the two are not distinguishable
> from each another.
>
> I'm planning (hoping) to implement detection of invalid pointer
> arithmetic involving null for GCC 12, so this patch is a stopgap
> solution to unblock the arm libatomic build without compromising
> the warning.  Once the new detection is in place these workarounds
> can be removed or replaced with something more appropriate (e.g.,
> declaring the objects at the hardwired addresses with an attribute
> like AVR's address or io; that would enable bounds checking at
> those addresses as well).
>
>
May I ping this patch?
ARM toolchain build (cross & bootstrap) has been  broken for more
than a week, preventing regression detection.

Thanks,

Christophe

Martin
>