Re: [trans-mem,darwin] PR/52042 find tm_clone_table with PIE

[Patrick Marlier <patrick dot marlier at gmail dot com>]

On 02/08/2012 12:12 AM, Jack Howarth wrote:
> I believe the remaining libitm.c++/eh-1.C execution test failures are due to
> the weakref linker bug currently in Xcode 4.x (radr://10466868) which I hae been
> told will be fixed in the next Xcode release after Xcode 4.3.
>                  Jack

Humm... In fact, not completely. Of course, if the linker was working, 
the HAVE_ELF_STYLE_WEAKREF will be defined and no problem.

Otherwise in the eh-1.c, we can see that _ITM_cxa_allocation_exception 
is using the dummy function __cxa_allocation_exception defined into 
eh_cpp.cc but not the one from libstdc++. There is no dynamic symbol 
resolution since the function is defined in the file.

I do not really know why those functions are defined here, I think it 
may causes more problems than it solves for darwin.

When Rainer introduced this, he mentioned "on Tru64 UNIX. Of course it 
cannot work to provide only a single dummy function, but all weak 
definitions must be backed by dummy definitions on that platform."
http://patchwork.ozlabs.org/patch/126007/

Iain mentioned this when he introduced the dummy def for darwin:
*** FWIW, weakref actually work (at runtime) for earlier Darwin
- it's just that refs either need to be satisfied by dummies at link time -
- or the library namespace has to be flattened (which is generally 
undesirable).

I think refs (from libstdc++) should be satisfied at link time with 
-lstdc++ but probably I am missing something?

Note that removing definitions in eh_cpp.cc make the test passes.

Thanks guys!
--
Patrick.