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

[Paul Menzel]

Dear Fangrui,


Am 16.08.21 um 21:06 schrieb Fangrui Song via Grub-devel:
> Clang 14.0.0 has implemented -falign-loops=1 but -falign-jumps=1 is
> still unsupported. The check should test all flags which may be added

“alignment” flags?

> into CFLAGS.
>
> Signed-off-by: Fangrui Song <maskray@google.com>
> ---
>   configure.ac | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/configure.ac b/configure.ac
> index bee28dbeb..b2fd0c3e4 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -799,14 +799,14 @@ 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"
> +    CFLAGS="$TARGET_CFLAGS -falign-jumps=1 -falign-loops=1 -falign-functions=1 
> -Werror"

I guess the `AC_CACHE_CHECK` description needs to be updated too?

Please mention in the commit message, why a separate check for each 
switch is not useful.

>       AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
>           [grub_cv_cc_falign_loop=yes],
>         [grub_cv_cc_falign_loop=no])
>     ])
>   
>     AC_CACHE_CHECK([whether -malign-loops works], [grub_cv_cc_malign_loop], [
> -    CFLAGS="$TARGET_CFLAGS -malign-loops=1 -Werror"
> +    CFLAGS="$TARGET_CFLAGS -malign-jumps=1 -malign-loops=1 -malign-functions=1 
> -Werror"
>       AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
>           [grub_cv_cc_malign_loop=yes],
>         [grub_cv_cc_malign_loop=no])

When you sent the v2, please include the maintainers listed in 
`MAINTAINERS` in the recipient list.


Kind regards,

Paul