Re: [PATCH] ubsan: don't mark __ubsan_handle_builtin_unreachable as noreturn

[Olof Johansson]

On Mon, Feb 5, 2018 at 2:31 AM Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> wrote:
>
> On 02/05/2018 01:15 PM, Arnd Bergmann wrote:
> > On Mon, Feb 5, 2018 at 10:02 AM, Andrey Ryabinin
> > <aryabinin@xxxxxxxxxxxxx> wrote:
> >>
> >>
> >> On 02/02/2018 06:47 PM, Arnd Bergmann wrote:
> >>> gcc-8 complains about the prototype for this function:
> >>>
> >>> lib/ubsan.c:432:1: error: ignoring attribute 'noreturn' in declaration of a built-in function '__ubsan_handle_builtin_unreachable' because it conflicts with attribute 'const' [-Werror=attributes]
> >>>
> >>
> >> That's actually a bug in GCC. In GCC __ubsan_handle_builtin_unreachable declared
> >> with 'noreturn' and 'const' attributes:
> >>
> >> DEF_SANITIZER_BUILTIN(BUILT_IN_UBSAN_HANDLE_BUILTIN_UNREACHABLE,
> >>                       "__ubsan_handle_builtin_unreachable",
> >>                       BT_FN_VOID_PTR,
> >>                       ATTR_COLD_CONST_NORETURN_NOTHROW_LEAF_LIST)
> >>
> >>
> >> But const attribute doesn't make any sense for function that returns void or doesn't return at all.
> >> Given that gcc-8 has not released yet, it would be better to fix this bug there.
> >
> > Ok. Should I open a gcc bug, or will you take care of it?
> >
>
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84210

8.2.0 still shows this, and there's been no movement on that bug. How
about we pick up this patch until it's been resolved?


-Olof