Re: [Qemu-devel] [PATCH] configure: make it possible to disable IASL

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Nov 24, 2013 at 02:54:51PM +0100, Stefan Weil wrote:
> Am 24.11.2013 14:42, schrieb Michael S. Tsirkin:
> > On Sun, Nov 24, 2013 at 03:04:04PM +0200, Marcel Apfelbaum wrote:
> >> On Sun, 2013-11-24 at 11:52 +0200, Michael S. Tsirkin wrote:
> >>> Useful for platforms with a broken IASL.
> >>>
> >>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> >>> ---
> >>>  configure | 3 ++-
> >>>  1 file changed, 2 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/configure b/configure
> >>> index 0592ba7..d0a0abe 100755
> >>> --- a/configure
> >>> +++ b/configure
> >>> @@ -1080,6 +1080,7 @@ echo "  --source-path=PATH       path of source code [$source_path]"
> >>>  echo "  --cross-prefix=PREFIX    use PREFIX for compile tools [$cross_prefix]"
> >>>  echo "  --cc=CC                  use C compiler CC [$cc]"
> >>>  echo "  --iasl=IASL              use ACPI compiler IASL [$iasl]"
> >>> +echo "                           iasl='' (empty string) disables ACPI compiler"
> >>>  echo "  --host-cc=CC             use C compiler CC [$host_cc] for code run at"
> >>>  echo "                           build time"
> >>>  echo "  --cxx=CXX                use C++ compiler CXX [$cxx]"
> >>> @@ -4269,7 +4270,7 @@ else
> >>>  fi
> >>>  echo "PYTHON=$python" >> $config_host_mak
> >>>  echo "CC=$cc" >> $config_host_mak
> >>> -if $iasl -h > /dev/null 2>&1; then
> >>> +if test "$iasl" && $iasl -h > /dev/null 2>&1; then
> >>>    echo "IASL=$iasl" >> $config_host_mak
> >>>  fi
> >>>  echo "CC_I386=$cc_i386" >> $config_host_mak
> >> I tried to disable iasl without this patch and it worked for me...
> >> I used:
> >>     - [Qemu-devel] [PATCH] configure: make --iasl option actually work
> >>     - ./configure --iasl="" (or --iasl=)
> >> and it worked (no sign of IASL in config-host.mak)
> >>
> >> I think this is because the prev test "$iasl -h > /dev/null 2>&1"
> >> fails of course.
> > By luck, yes.
> >
> > So this is just a documentation patch: cleaner to document the
> > interface explicitly.
> > I'll make this clearer in the commit log.
> >
> 
> --iasl=false works without further modifications (because test "false
> -h" works and returns false). It also looks more natural than --iasl=.
> 
> Cheers, Stefan

It seems that some people try --iasl= as the more natural way
to do this. It's not documented that a failing iasl will
cause a fall-back and I'd rather document an explicit option
than making it fail.