On Mon, Jun 15, 2020 at 5:30 PM Matthias Klose <d...@ubuntu.com> wrote:
>
> PR lto/95604 was seen when checking for binaries without having CET support
> in a
> distro archive, for binaries built with LTO optimization. The hardening flag
> -fcf-protection=full is passed in CFLAGS, and maybe should be passed in
> LDFLAGS
> as well. However to make it work when not passed to the link step, it should
> be
> extracted from the options found in the lto opts section.
>
> Richard suggested two solutions offline. I checked that both fix the test
> case.
> Which one to install? Also ok for the 9 and 10 branches?
I guess even though variant two is simpler it doesn't make much sense to
have differing settings of -fcf-protection between different functions? HJ?
So looking at variant one,
@@ -287,6 +287,18 @@
foption->orig_option_with_args_text);
break;
+ case OPT_fcf_protection_:
+ /* Append or check identical. */
+ for (j = 0; j < *decoded_options_count; ++j)
+ if ((*decoded_options)[j].opt_index == foption->opt_index)
+ break;
+ if (j == *decoded_options_count)
+ append_option (decoded_options, decoded_options_count, foption);
+ else if (strcmp ((*decoded_options)[j].arg, foption->arg))
+ warning (input_location, "option %s with different values",
+ foption->orig_option_with_args_text);
+ break;
you are always streaming a -fcf-protection option so the if (j ==
*decoded_options_count)
case shouldn't ever happen but I guess it's safe to leave the code
as-is. Can you
amend the warning with the option that prevails? Maybe
+ else if (strcmp ((*decoded_options)[j].arg, foption->arg))
{
static bool noted;
+ warning (input_location, "option %s with different values",
+ foption->orig_option_with_args_text);
if (!noted)
{
inform ("%s will be used instead",
(*decoded_options)[j].orig_option_with_args_text);
noted = true;
}
I guess input_location is simply zero so the diagnostic doesn't
contain the actual file we're
looking at. Something to improve I guess (also applyign to other
diagnostics we emit).
Otherwise looks OK.
Please wait for HJ in case he'd like to go with option two.
Thanks,
Richard.
> Thanks, Matthias
>
>
