Re: [PATCH 04/10] configure: create native file with contents of $host_cc

[Daniel P . Berrangé]

On Tue, Aug 29, 2023 at 10:29:25AM +0200, Paolo Bonzini wrote:
> The argument of --host-cc is not obeyed when cross compiling.  To avoid
> this issue, place it in a configuration file and pass it to meson
> with --native-file.
> 
> While at it, clarify that --host-cc is not obeyed anyway when _not_
> cross compiling.

I presume that's refering to this piece of code

if test -z "${CC}${cross_prefix}"; then
  cc="$host_cc"
else
  cc="${CC-${cross_prefix}gcc}"
fi

which is using $host_cc *before* --host-cc is processed, thus
meaning it is always at its default value of 'cc'.

Perhaps the above code snippet should just be changed to

  if test -z "${CC}${cross_prefix}"; then
    cc="cc"
  else
    cc="${CC-${cross_prefix}gcc}"
  fi

to make it clear that we were not intending to honour the
--host-cc value for this code.

> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  configure | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)

None the less, this patch is correct, so with or without
that above change:

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

> 
> diff --git a/configure b/configure
> index 3423f008d5c..b2bc1ff5f7b 100755
> --- a/configure
> +++ b/configure
> @@ -922,7 +922,7 @@ Advanced options (experts only):
>    --cross-prefix=PREFIX    use PREFIX for compile tools, PREFIX can be blank 
> [$cross_prefix]
>    --cc=CC                  use C compiler CC [$cc]
>    --host-cc=CC             use C compiler CC [$host_cc] for code run at
> -                           build time
> +                           build time when cross compiling
>    --cxx=CXX                use C++ compiler CXX [$cxx]
>    --objcc=OBJCC            use Objective-C compiler OBJCC [$objcc]
>    --extra-cflags=CFLAGS    append extra C compiler flags CFLAGS
> @@ -1886,7 +1886,6 @@ if test "$skip_meson" = no; then
>    echo "windres = [$(meson_quote $windres)]" >> $cross
>    echo "windmc = [$(meson_quote $windmc)]" >> $cross
>    if test "$cross_compile" = "yes"; then
> -    cross_arg="--cross-file config-meson.cross"
>      echo "[host_machine]" >> $cross
>      echo "system = '$targetos'" >> $cross
>      case "$cpu" in
> @@ -1903,6 +1902,14 @@ if test "$skip_meson" = no; then
>      else
>          echo "endian = 'little'" >> $cross
>      fi
> +    cross_arg="--cross-file config-meson.cross"
> +
> +    native="config-meson.native.new"
> +    echo "# Automatically generated by configure - do not modify" > $native
> +    echo "[binaries]" >> $native
> +    echo "c = [$(meson_quote $host_cc)]" >> $native
> +    mv $native config-meson.native
> +    cross_arg="$cross_arg --native-file config-meson.native"
>    else
>      cross_arg="--native-file config-meson.cross"
>    fi
> -- 
> 2.41.0
> 
> 

With regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|