Re: [PATCH] compiler.h: update definition of unreachable()

[Miguel Ojeda]

On Mon, Oct 15, 2018 at 7:22 PM <ndesaulniers@xxxxxxxxxx> wrote:
>
> Fixes the objtool warning seen with Clang:
> arch/x86/mm/fault.o: warning: objtool: no_context()+0x220: unreachable
> instruction
>
> Fixes commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h
> mutually exclusive")
>
> Josh noted that the fallback definition was meant to work around a
> pre-gcc-4.6 bug. GCC still needs to work around
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365, so compiler-gcc.h
> defines its own version of unreachable().  Clang and ICC can use this
> shared definition.

Could we, at the same time, update the comment on compiler-gcc.h as
well? i.e. remove the 4.5 comment, add the link to the GCC PR.

>
> Link: https://github.com/ClangBuiltLinux/linux/issues/204
> Suggested-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
> Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
> Miguel, would you mind taking this up in your new compiler attributes
> tree?

Sure, will do.

Thanks,

Cheers,
Miguel