Re: [PATCH] basic perf support for sparc

[Ingo Molnar <mingo@elte.hu>]

* Arnaldo Carvalho de Melo <acme@redhat.com> wrote:

> Em Sat, Aug 01, 2009 at 10:20:48AM +0200, Jens Axboe escreveu:
> > On Sat, Aug 01 2009, Anton Blanchard wrote:
> > > 
> > > Hi,
> > > 
> > > > > Building the perf tool is somewhat involved on sparc64
> > > > > though, since 64-bit versions of zlib/libelf/bfd aren't
> > > > > directly available (at least on debian 5.x). But once you
> > > > > get there, it runs :-). Would it be easier/functional
> > > > > to build 32-bit userland perf instead?
> > > > 
> > > > Same is true on ppc64, btw. How are others handling this?
> > > 
> > > The requirement for libz was removed, so up until recently we only needed
> > > a 64bit version of elfutils which is easy to build.
> > > 
> > > It looks like we now have a requirement on binutils which is considerably
> > > more painful to build. One option is to make the bfd requirement optional, all
> > > you lose would be the ability to see c++ demangled names I think.
> > 
> > Right, binutils is the ugly one. I got a libbfd.so built for 
> > both ppc and sparc, but it wasn't just a make && make install 
> > job. Personally I could not care less about losing c++ demangled 
> > name support, so that approach sounds fine to me :-)
> 
> Exactly, for a huge number of developers not being able to see 
> demangled C++ is okay, so I agree on adding smarts to not demangle 
> when binutils-devel is not available.
> 
> I thought about extracting the demangling bits out of binutils, 
> ran away screaming. I also hoped elfutils would have that by now, 
> but it doesn't.

Could we somehow define a weak symbol for those library functions 
ourselves and thus just fall back to that (which does nothing) 
instead of failing the link?

	Ingo