Re: [V2][PATH 0/6] Explicit_bzero improvement

[Bastien ROUCARIES]

Thank you for the clarification.

I will do it.

On Sun, Apr 12, 2020 at 1:33 PM Bruno Haible <address@hidden> wrote:
>
> Hi Bastien,
>
> > [PATCH 1/6] Use memset_s if possible for explicit_bzero
> > [PATCH 2/6] Use SecureZeroMemory on windows for explicit_bzero
> > [PATCH 3/6] Support clang for explicit_bzero
> > [PATCH 4/6] Implement fallback for explicit_bzero using jump to
> > [PATCH 5/6] Improve styling in explicit_bzero
> > [PATCH 6/6] Add test for explicit_bzero
>
> I would reorder the patch series so that adding the unit test comes first.
> This allows to check against regressions in the other patches.
>
> Then, patch 1, 2, 3 look good but would have to be tested (on FreeBSD 12,
> Solaris 11.4, native Windows, clang). On which systems can you test? I
> do have test capacities, but I don't want to waste time testing the same
> platforms that you have already tested.
>
> I would refrain from applying patch 4, because it is more complex than
> what seems needed. You cite the C standard regarding 'volatile'. It is
> 'volatile' which prevents the compiler from "looking inside the function
> pointer"; that does not require 'static' nor a runtime computation.
> I may be wrong on this, but if I'm wrong, the unit test will tell us.
> So, I would propose to
>   1. simplify patch 4 to a simple use of a volatile function pointer,
>   2. test it on the relevant platforms (a non-GCC, non-clang compiler:
>      that is MSVC, Solaris cc, HP cc, AIX xlc).
>   3. use more complex code only of one of these tests indicates that
>      it is required.
>
> Patch 5 is evidently OK.
>
> Bruno
>