Re: [PATCH v2 4/7] configure: Always detect -no-pie toolchain support

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> The CFLAGS_NOPIE and LDFLAGS_NOPIE variables are used
> in pc-bios/optionrom/Makefile, which has nothing to do
> with the PIE setting of the main qemu executables.
>
> This overrides any operating system default to build
> all executables as PIE, which is important for ROMs.

But if the compiler doesn't support no-pie it just keeps going on.
Should the sub-build be bailing if _NOPIE is empty?

>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  configure | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/configure b/configure
> index 99faf64a74..7a646ec007 100755
> --- a/configure
> +++ b/configure
> @@ -2018,26 +2018,24 @@ if ! compile_prog "-Werror" "" ; then
>  	"Thread-Local Storage (TLS). Please upgrade to a version that does."
>  fi
>  
> -if test "$pie" != "no" ; then
> -  cat > $TMPC << EOF
> +cat > $TMPC << EOF
>  
>  #ifdef __linux__
>  #  define THREAD __thread
>  #else
>  #  define THREAD
>  #endif
> -
>  static THREAD int tls_var;
> -
>  int main(void) { return tls_var; }
> -
>  EOF
> -  # check we support --no-pie first...
> -  if compile_prog "-Werror -fno-pie" "-no-pie"; then
> -    CFLAGS_NOPIE="-fno-pie"
> -    LDFLAGS_NOPIE="-nopie"
> -  fi
>  
> +# Check we support --no-pie first; we will need this for building ROMs.
> +if compile_prog "-Werror -fno-pie" "-no-pie"; then
> +  CFLAGS_NOPIE="-fno-pie"
> +  LDFLAGS_NOPIE="-no-pie"
> +fi
> +
> +if test "$pie" != "no" ; then
>    if compile_prog "-fPIE -DPIE" "-pie"; then
>      QEMU_CFLAGS="-fPIE -DPIE $QEMU_CFLAGS"
>      LDFLAGS="-pie $LDFLAGS"


-- 
Alex Bennée