Re: [PATCH 2/2] configure: Check -falign-jumps=1 -falign-functions=1 beside -falign-loops=1

[Fangrui Song]

On 2021-08-25, Daniel Kiper wrote:
> On Mon, Aug 23, 2021 at 11:18:38PM -0700, Fangrui Song wrote:
> > Clang does not support -falign-jumps and only recently gained support
> > for -falign-loops. Test all the alignment options to avoid passing
> > unrecognized options to Clang:
> >
> >     clang-14: error: optimization flag '-falign-jumps=1' is not supported 
> > [-Werror,-Wignored-optimization-argument]
> >
> > When compiled with older Clang, the alignment options are not added, so
> > just avoid the complexity for each option.
> >
> > Signed-off-by: Fangrui Song <maskray@google.com>
> > ---
> >  configure.ac | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/configure.ac b/configure.ac
> > index 9a12151bd..8625e6776 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -798,8 +798,9 @@ fi
> >
> >  # Force no alignment to save space on i386.
> >  if test "x$target_cpu" = xi386; then
> > -  AC_CACHE_CHECK([whether -falign-loops works], [grub_cv_cc_falign_loop], [
> > -    CFLAGS="$TARGET_CFLAGS -falign-loops=1 -Werror"
> > +  AC_CACHE_CHECK([whether -falign-jumps=1 -falign-loops=1 -falign-functions=1 
> > works],
> > +    [grub_cv_cc_falign_loop], [
> > +    CFLAGS="$TARGET_CFLAGS -falign-jumps=1 -falign-loops=1 -falign-functions=1 
> > -Werror"
>
> I would prefer if you add a separate check for every -falign-* option.
>
> Daniel

The attached patch checks both -falign-jumps=1 and -falign-loops=1

0001-configure-Check-falign-jumps-1-beside-falign-loops-1.patch
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