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

From: [email-masked] (Jason Baron)
Date: Tue, 7 Feb 2012 13:04:23 -0500

On Tue, Feb 07, 2012 at 09:48:24PM +0530, Rabin Vincent wrote:
> Jason,
> 
> On Sat, Jan 28, 2012 at 19:05, Rabin Vincent <[email-masked]> 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 <[email-masked]>
> > Cc: linux-kernel at vger.kernel.org
> > Signed-off-by: Rabin Vincent <[email-masked]>
> 
> 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 <[email-masked]>
> >
> > -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 <[email-masked]>