Re: [PATCH, DARWIN] fix emutls exports in libgcc_s10.{4,5}.dylib

[IainS <developer at sandoe-acoustics dot co dot uk>]

On 11 Dec 2008, at 13:51, Jack Howarth wrote:

> On Thu, Dec 11, 2008 at 12:38:11PM +0000, IainS wrote:
> ...
> > I have a hunch that this is, at least partially, the origin of  
> > sporadic
> > failures in crayptr2 (which has been one of the very few tests  
> > using tls
> > so far - because all the rest have been UNSUPPORTED by the fails  
> > in dg
> > target supports).
> ...
>
> No. The random failures in crayptr2 are due to multiple threads  
> reading
> an offset value of 0 and is fixed by the proposed patch...
>
> http://gcc.gnu.org/bugzilla/attachment.cgi?id=16879

actually, the deeper one digs ...

it seems that libgomp is not being built with tls emulation.

(for exactly the same reasons - the configure test fails with the  
unresolved __emutls...  symbol)

from libgomp/config.h
/* Define to 1 if the target assembler supports thread-local storage. */
/* #undef HAVE_CC_TLS */

....

/* Define to 1 if the target supports thread-local storage. */
/* #undef HAVE_TLS */

and libgomp/config.log

tchCS/gcc-440-install/powerpc-apple-darwin8.11.0/sys-include -o  
conftest -g -O2   -pthread   conftest.c  >&5
/usr/libexec/gcc/powerpc-apple-darwin8/4.0.1/ld: Undefined symbols:
___emutls_get_address
collect2: ld returned 1 exit status
configure:17892: $? = 1
configure: program exited with status 1
configure: failed program was:
| __thread int a; int b; int main() { return a = b; }
configure:18104: result: no


----

So, I guess,  the libgomp tests should not be built with TLS  
emulation ; and any test requiring TLS should be hidden behind a
{ dg-require-effective-target tls_runtime }

which was a proposal anyway ( http://gcc.gnu.org/ml/fortran/2008-12/ 
msg00155.html).

----

at least this will be consistent until such time as a general  
solution to making the emulation available is agreed.

(and that means addressing the general issues I raised earlier).

Iain