[Bug other/55354] [asan] by default, the asan run-time should be linked statically, not dynamically

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55354

--- Comment #21 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-21 09:23:56 UTC ---
(In reply to comment #20)
> What I see is that it also affect code generation (register allocation). Do we
> need to file a bug on that?

If you see a code generation difference even with -ftls-model=local-exec -fPIC
vs. -fPIE, then it must mean you don't have visibility attributes on the
symbols used in the fast path.  For initial-exec, the RA effects should be
minimal, the TLS offset load from got is usually very close to the actual TLS
memory load (or lea), and thus it will just pick up some short lived scratch
register.  Generally in GCC, -fPIE sets flag_pic and not flag_shlib, while
-fPIC sets flag_pic and flag_shlib.  flag_pic is about whether position
independent code needs to be generated, flag_shlib is about whether locally
defined symbols can be interposed (plus it affects TLS model default choice).

> For dynamic libraries that are loaded into a non-instrumented executable (e.g.
> swig so preloaded into python process), we statically link the tsan runtime
> into the so.

And you don't get linker errors from that?  That must be by pure luck.