llvm dev - Nov 2014 - [LLVMdev] Issue with std::call_once in PPC64 platform

Hi Bill,

You can find the same issue in the buildbot:

http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/16444/steps/compile.llvm.stage2/logs/stdio

It is failing for me both in BE (gcc 4.8.2) and LE(4.9.1). I am compiling
with clang 3.5, but those are the gcc toolchains I am using.

What do you think is the best way to fix this?

Thanks!
Samuel

Bill Schmidt <wschmidt at linux.vnet.ibm.com> wrote on 11/04/2014 11:45:06
AM:
> From: Bill Schmidt <wschmidt at linux.vnet.ibm.com>
> To: Samuel F Antao/Watson/IBM at IBMUS
> Cc: LLVM Dev <llvmdev at cs.uiuc.edu>, beanz at apple.com, Hal Finkel
> <hfinkel at anl.gov>, azanella at linux.vnet.ibm.com
> Date: 11/04/2014 11:45 AM
> Subject: Re: Issue with std::call_once in PPC64 platform
>
> Hi Samuel,
>
> I haven't encountered this problem.  What gcc/libstdc++ are you using?
> BE or LE?
>
> 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
> >
> >
>
>
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On Tue, 2014-11-04 at 11:59 -0500, Samuel F Antao wrote:
> Hi Bill,
> 
> You can find the same issue in the buildbot:
> 
>
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/16444/steps/compile.llvm.stage2/logs/stdio
> 
> It is failing for me both in BE (gcc 4.8.2) and LE(4.9.1). I am
> compiling with clang 3.5, but those are the gcc toolchains I am using.
> 
> What do you think is the best way to fix this?
I don't know what the best fix is, but clearly a fix or revert is needed
since the patch is breaking some platforms.

Thanks,
Bill
> 
> Thanks!
> Samuel 
> 
> Bill Schmidt <wschmidt at linux.vnet.ibm.com> wrote on 11/04/2014
> 11:45:06 AM:
> 
> > From: Bill Schmidt <wschmidt at linux.vnet.ibm.com>
> > To: Samuel F Antao/Watson/IBM at IBMUS
> > Cc: LLVM Dev <llvmdev at cs.uiuc.edu>, beanz at apple.com, Hal
Finkel
> > <hfinkel at anl.gov>, azanella at linux.vnet.ibm.com
> > Date: 11/04/2014 11:45 AM
> > Subject: Re: Issue with std::call_once in PPC64 platform
> > 
> > Hi Samuel,
> > 
> > I haven't encountered this problem.  What gcc/libstdc++ are you
> using?
> > BE or LE?
> > 
> > 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
> > > 
> > > 
> > 
> > 
> 
>

Ok, I'll put a patch together to fix this later today. I'll probably do
what Reid was suggesting and use what is already in there for Windows.

Thanks,
Samuel

Bill Schmidt <wschmidt at linux.vnet.ibm.com> wrote on 11/04/2014 12:11:08
PM:
> From: Bill Schmidt <wschmidt at linux.vnet.ibm.com>
> To: Samuel F Antao/Watson/IBM at IBMUS
> Cc: azanella at linux.vnet.ibm.com, beanz at apple.com, Hal Finkel
> <hfinkel at anl.gov>, LLVM Dev <llvmdev at cs.uiuc.edu>
> Date: 11/04/2014 12:11 PM
> Subject: Re: Issue with std::call_once in PPC64 platform
>
> On Tue, 2014-11-04 at 11:59 -0500, Samuel F Antao wrote:
> > Hi Bill,
> >
> > You can find the same issue in the buildbot:
> >
> > http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/
> 16444/steps/compile.llvm.stage2/logs/stdio
> >
> > It is failing for me both in BE (gcc 4.8.2) and LE(4.9.1). I am
> > compiling with clang 3.5, but those are the gcc toolchains I am using.
> >
> > What do you think is the best way to fix this?
>
> I don't know what the best fix is, but clearly a fix or revert is
needed
> since the patch is breaking some platforms.
>
> Thanks,
> Bill
>
> >
> > Thanks!
> > Samuel
> >
> > Bill Schmidt <wschmidt at linux.vnet.ibm.com> wrote on
11/04/2014
> > 11:45:06 AM:
> >
> > > From: Bill Schmidt <wschmidt at linux.vnet.ibm.com>
> > > To: Samuel F Antao/Watson/IBM at IBMUS
> > > Cc: LLVM Dev <llvmdev at cs.uiuc.edu>, beanz at apple.com,
Hal Finkel
> > > <hfinkel at anl.gov>, azanella at linux.vnet.ibm.com
> > > Date: 11/04/2014 11:45 AM
> > > Subject: Re: Issue with std::call_once in PPC64 platform
> > >
> > > Hi Samuel,
> > >
> > > I haven't encountered this problem.  What gcc/libstdc++ are
you
> > using?
> > > BE or LE?
> > >
> > > 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
> > > >
> > > >
> > >
> > >
> >
> >
>
>
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