Re: [build] Move unwinder to toplevel libgcc (v2)

[Paolo Bonzini <bonzini at gnu dot org>]

On 08/11/2011 08:24 PM, H.J. Lu wrote:
> On Thu, Aug 11, 2011 at 11:19 AM, H.J. Lu<hjl.tools@gmail.com>  wrote:
> > On Thu, Aug 11, 2011 at 8:23 AM, Rainer Orth
> > <ro@cebitec.uni-bielefeld.de>  wrote:
> > > Paolo Bonzini<bonzini@gnu.org>  writes:
> > >
> > > > On 08/10/2011 06:05 PM, Rainer Orth wrote:
> > > > > > > > >   True: it is called once per multilib.
> > > > > > >
> > > > > > >   Just to doublecheck, are we sure that unwind.h is always the same?
> > > > > Yep: it's unwind-generic.h for almost all targets, just a few arm
> > > > > targets use config/arm/unwind-arm.h for all multilibs.
> > > >
> > > > Patch doing rm -f is preapproved then.
> > >
> > > Here's what I installed, after making libgcc/unwind-generic.h read-only,
> > > reconfiguring and rebuilding first without and with the patch and
> > > observe the bug gone on i386-pc-solaris2.10.
> > >
> > >         Rainer
> > >
> > >
> > > 2011-08-11  Rainer Orth<ro@CeBiTec.Uni-Bielefeld.DE>
> > >
> > >         * Makefile.in (install-unwind_h): Remove destination file first.
> > >
> > > diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
> > > --- a/libgcc/Makefile.in
> > > +++ b/libgcc/Makefile.in
> > > @@ -994,6 +994,7 @@ gcc-extra-parts:
> > >   all: $(extra-parts)
> > >
> > >   install-unwind_h:
> > > +       rm -f $(gcc_objdir)/include/unwind.h
> > >         cp unwind.h $(gcc_objdir)/include/unwind.h
> > >         chmod a+r $(gcc_objdir)/include/unwind.h
> >
> > It breaks bootstrap with "make -j12" on a 24 core Linux/x86-64  :
> >
> > http://gcc.gnu.org/ml/gcc-regression/2011-08/msg00179.html
> >
> > rm -f ../../.././gcc/include/unwind.h
> > cp unwind.h ../../.././gcc/include/unwind.h
> > rm -f ../.././gcc/include/unwind.h
> > chmod a+r ../../.././gcc/include/unwind.h
> > cp unwind.h ../.././gcc/include/unwind.h
> > chmod: cannot access `../../.././gcc/include/unwind.h': No such file
> > or directory
> > make[8]: *** [install-unwind_h] Error 1
> > make[8]: *** Waiting for unfinished jobs....
> > chmod a+r ../.././gcc/include/unwind.h
> >
> > We may have a race condition here.
>
> I opened:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50047

Does the attached patch work?

Paolo

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