[Bug bootstrap/56128] [4.8 Regression] libsanitizer doesn't build with broken kernel headers

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56128

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-11 12:08:11 UTC ---
(In reply to comment #9)
> (In reply to comment #8)
> > Requires a merge as far as I can see.  Important enough build issue.
> 
> I am reluctant to do another full merge so close to 4.8 -- we have too many
> intrusive changes in upstream trunk. 
> 
> Jakub, WDYT? 
> Maybe we just apply http://llvm.org/viewvc/llvm-project?rev=173933&view=rev
> once 4.8 branches out? 
> (Not sure if the gcc development process works this way...)

We need more than that.  E.g. ppc64 asan is very much broken in the gcc tree,
that is fixed in upstream libasan already, right?

I'd think we should just do one more llvm -> libsanitizer merge soon (after the
scanf stuff is resolved?).  A slight complication is that asan_test.cc got
split into smaller tests, but even for GCC it will be worthwhile to have fewer
smaller tests I guess, we'll just need to add the wrappers.

BTW, any progress with the 0x7fff8000 shadow offset for x86_64?  If it looks
good benchmark-wise, I think it would be better if we switched the ASAN x86_64
ABI for GCC sooner (read, before 4.8) than have one asan ABI for 4.8 built
objects and another one for 4.9 built objects (which is still possible that it
will happen, but it wouldn't hurt to avoid that).