[PATCHv2 5/6] jump label: detect %c support for ARM

[Jason Baron]

On Tue, Feb 07, 2012 at 09:48:24PM +0530, Rabin Vincent wrote:
> Jason,
> 
> On Sat, Jan 28, 2012 at 19:05, Rabin Vincent <rabin at rab.in> wrote:
> > Some versions of ARM GCC which do support asm goto, have problems
> > handling the the %c specifier.  Since we need the %c to support jump
> > labels on ARM, detect that too in the asm goto detection script to avoid
> > build errors with these versions.
> >
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637
> >
> > Cc: Jason Baron <jbaron at redhat.com>
> > Cc: linux-kernel at vger.kernel.org
> > Signed-off-by: Rabin Vincent <rabin at rab.in>
> 
> Could you please ack this patch if it's OK for you?  Then I could try to
> send it via rmk's ARM patch system along with the rest of the series.
> 
> Thanks.
> 
> > ---
> >  scripts/gcc-goto.sh |   18 +++++++++++++++++-
> >  1 files changed, 17 insertions(+), 1 deletions(-)
> >
> > diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh
> > index 98cffcb..9b744de 100644
> > --- a/scripts/gcc-goto.sh
> > +++ b/scripts/gcc-goto.sh
> > @@ -2,4 +2,20 @@
> >  # Test for gcc 'asm goto' support
> >  # Copyright (C) 2010, Jason Baron <jbaron at redhat.com>
> >
> > -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y"
> > +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y"
> > +int main(void)
> > +{
> > +#ifdef __arm__
> > +       /*
> > +        * Not related to asm goto, but used by jump label
> > +        * and broken on some ARM GCC versions (see GCC Bug 48637).
> > +        */
> > +       static struct { int dummy; int state; } tp;
> > +       asm ("@ %c0" :: "i" (&tp.state));
> > +#endif
> > +
> > +entry:
> > +       asm goto ("" :::: entry);
> > +       return 0;
> > +}
> > +END
> > --
> > 1.7.8.3
> >

Sure, patch works for me.

Acked-by: Jason Baron <jbaron at redhat.com>