[PATCH 6/8] x86_64: Fix mark-plt configure test

[H.J. Lu]

On Thu, Dec 18, 2025 at 1:56 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
> The configure check might ignore if compiler driver warns that the
> option is no support, so force fatal warnings.
>
> If fixes the elf/tst-plt-rewrite{1,2} regressions when ld.lld is used.
> ---
>  sysdeps/x86_64/configure    | 4 ++--
>  sysdeps/x86_64/configure.ac | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/sysdeps/x86_64/configure b/sysdeps/x86_64/configure
> index 32324f62da..b4d8bf1370 100644
> --- a/sysdeps/x86_64/configure
> +++ b/sysdeps/x86_64/configure
> @@ -67,7 +67,7 @@ cat > conftest.c <<EOF
>  int _start (void) { return 42; }
>  EOF
>  if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
> -                 -Wl,-z,mark-plt -nostdlib -nostartfiles
> +                 -Wl,-z,mark-plt -Wl,--fatal-warnings -nostdlib -nostartfiles
>                   -fPIC -shared -o conftest.so conftest.c
>                   1>&5'
>    { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> @@ -76,7 +76,7 @@ if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
>    printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
>    test $ac_status = 0; }; }
>  then
> -  if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp -Wl,-z,mark-plt -nostdlib \
> +  if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp -Wl,-z,mark-plt, -Wl,--fatal-warnings -nostdlib \
>        -nostartfiles -fPIC -shared -o conftest.so conftest.c 2>&1 \
>        | grep "warning: -z mark-plt ignored" > /dev/null 2>&1; then
>      true
> diff --git a/sysdeps/x86_64/configure.ac b/sysdeps/x86_64/configure.ac
> index a00958e219..c4ef4319e4 100644
> --- a/sysdeps/x86_64/configure.ac
> +++ b/sysdeps/x86_64/configure.ac
> @@ -13,7 +13,7 @@ LIBC_TRY_CC_AND_TEST_CC_OPTION([for -mprefer-vector-width=128],
>  LIBC_CONFIG_VAR([config-cflags-mprefer-vector-width],
>                 [$libc_cv_cc_mprefer_vector_width])
>
> -LIBC_LINKER_FEATURE([-z mark-plt], [-Wl,-z,mark-plt],
> +LIBC_LINKER_FEATURE([-z mark-plt], [-Wl,-z,mark-plt -Wl,--fatal-warnings],
>                      [libc_cv_z_mark_plt=yes], [libc_cv_z_mark_plt=no])
>  LIBC_CONFIG_VAR([have-z-mark-plt], [$libc_cv_z_mark_plt])
>
> --
> 2.43.0
>

LGTM.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

Thanks.

-- 
H.J.