[LLVMdev] Issue with std::call_once in PPC64 platform

[Bill Schmidt]

On Tue, 2014-11-04 at 10:45 -0600, Bill Schmidt wrote:
> Hi Samuel,
> 
> I haven't encountered this problem.  What gcc/libstdc++ are you using?
> BE or LE?

Never mind!  We see this, but only when building for self-host.  The
PPC64 clang self-host buildbot has been failing with problem as well.

It would be good to have a fix for this issue, however temporary.

Thanks,
Bill

> 
> Copying Adhemerval in case he has heard of any related issues.
> 
> Thanks,
> Bill
> 
> On Mon, 2014-11-03 at 20:19 -0500, Samuel F Antao wrote:
> > Hi all,
> > 
> > I observe that r220932 (Removing the static initializer in
> > ManagedStatic.cpp by using llvm_call_once to initialize the
> > ManagedStatic mutex.) is causing tablegen to segfault in PPC platforms
> > during static initialization. The crash happens while calling
> >  std::call_once introduced by this patch in the wrapper used in
> > getManagedStaticMutex. 
> > 
> > I understand this call is buggy for some platforms (or probably some
> > oldish libstdc++ versions). Is this a known issue? Should we guard
> > LLVM_DEFINE_ONCE_FLAG definition with platform specific macros to
> > avoid the crash, at least for the moment?
> > 
> > Thanks!
> > Samuel
> > 
> > 
>