Excerpts from H.J. Lu's message of November 27, 2020 8:28 pm:
> On Fri, Nov 27, 2020 at 11:02 AM Matthias Klose <d...@ubuntu.com> wrote:
>>
>> On 11/27/20 3:54 PM, H.J. Lu via Gcc-patches wrote:
>> > On Fri, Nov 27, 2020 at 6:24 AM Richard Biener <rguent...@suse.de> wrote:
>> >>
>> >> OK.
>> >>
>> >> On Fri, 27 Nov 2020, H.J. Lu wrote:
>> >>
>> >>> PR other/98027
>> >>> * doc/install: Default to --enable-cet=auto.
>> >>> ---
>> >>> gcc/doc/install.texi | 9 ++++-----
>> >>> 1 file changed, 4 insertions(+), 5 deletions(-)
>> >>>
>> >>> diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
>> >>> index 5f879ca4cea..021c347cc09 100644
>> >>> --- a/gcc/doc/install.texi
>> >>> +++ b/gcc/doc/install.texi
>> >>> @@ -2259,11 +2259,10 @@ instrumentation, see @option{-fcf-protection}
>> >>> option. When
>> >>> to add @option{-fcf-protection} and, if needed, other target
>> >>> specific options to a set of building options.
>> >>>
>> >>> -The option is disabled by default. When @code{--enable-cet=auto}
>> >>> -is used, it is enabled on Linux/x86 if target binutils
>> >>> -supports @code{Intel CET} instructions and disabled otherwise.
>> >>> -In this case the target libraries are configured to get additional
>> >>> -@option{-fcf-protection} option.
>> >>> +@code{--enable-cet=auto} is default. CET is enabled on Linux/x86 if
>> >>> +target binutils supports @code{Intel CET} instructions and disabled
>> >>> +otherwise. In this case, the target libraries are configured to get
>> >>> +additional @option{-fcf-protection} option.
>> >>>
>> >>> @item --with-riscv-attribute=@samp{yes}, @samp{no} or @samp{default}
>> >>> Generate RISC-V attribute by default, in order to record extra build
>> >>>
>> >>
>> >
>> > OK for backport to GCC 10?
>>
>> I only found that because of failing package builds in a test rebuild. See
>> PR98025. Is it safe to backport that, if it breaks the ABI of a runtime
>> library
>
> libphobos has some CET issues which have been fixed in GCC 11.
>
There's still a remaining issue (see PR 98025) that I'm about to push a
fix for.
>> shipped with GCC 10?
>>
>
> It is just a documentation change.
>
I don't think the backport is necessary, as it is default disabled in
GCC 10. It was only at the beginning of the GCC 11 development cycle
that it got changed to default auto.
Iain.
