[PATCH, RFC] Enable libsanitizer on powerpc{,64}

[Peter Bergner]

On Tue, 2012-11-20 at 17:52 +0400, Konstantin Serebryany wrote:
> On Tue, Nov 20, 2012 at 5:41 PM, Peter Bergner <bergner@vnet.ibm.com> wrote:
> > Doing a quick peruse through your LLVM commit, I see you grabbed the
> > PopStackFrames() addition, but the asan_linux.cc changes do not include
> > the call to PopStackFrames() after the _Unwind_Backtrace() call.
> > Specifically, the following patch hunk:
> >
> >>      _Unwind_Backtrace(Unwind_Trace, stack);
> >> > +    // Pop off the two ASAN functions from the backtrace.
> >> > +    stack->PopStackFrames(2);
> 
> Ah, indeed, I missed that.
> Since the patch also affects ARM, I'd like to hear from Evgeniy Stepanov
> (or we may decouple powerpc from arm)

I specifically added that call for all architectures that use
_Unwind_Backtrace, since I believe they will all see the two
extra ASAN functions on the call stack since that is an artifact
of how _Unwind_Backtrace works.  That being said, it would be good
for someone to confirm that change works for ARM...or SPARC
once David gets the SPARC changes ready since he seems to me
not far behind us (ie, POWER).

Peter