On 8 Dec 2008, at 21:09, Andrew Pinski wrote:
On Mon, Dec 8, 2008 at 1:04 PM, IainS <[EMAIL PROTECTED]
acoustics.co.uk> wrote:
following on from http://gcc.gnu.org/ml/gcc/2008-05/msg00202.html
As I mentioned; it is emulated. So it works, by default, though it is
hm. At the moment it doesn't appear to work.
with configure options "--enable-threads" (or default options)
we get the situation described below.
with configure options "--enable-threads --enable-tls" we get an
assembler fault instead.
===== with "--enable-threads" (and also default options).
(see also PR32765 and http://gcc.gnu.org/ml/fortran/2008-12/
msg00118.html)
___emutls_get_address is defined in libgcc_s.1.dylib (and libgcc_eh.a)
As you suggest in the PR32765 thread, the problem is that libgcc_s.1
is not searched unless this is forced on the options line.
However, the problem is much wider than those two tests.
check_effective_target_tls_runtime in target-supports.exp also fails
with the same error - this "UNSUPPORTS" pretty much all TLS tests
across gcc on darwin8/9.
The only reason that the PR32765 issue was visible is that the two
test cases do not use { dg-require-effective-target tls_runtime }
====
The workaround used to close PR32765 no longer functions on darwin8
(unless the the compiler is installed before checking) - although it
does still work on darwin9.
The ___emutls_get_address in libgcc_s.1 also appears to have some
issues on 64bit processors, both PPC and Intel (at least when running
32 bit code).
The version in libgcc_eh does work (which is why the --static-libgcc
approach is succeeding on darwin9).
so a more closely targeted workaround is to use -lgcc_eh in any
darwin code that requires TLS (this works on darwin8 and darwin9).
However, this seems like a pretty messy solution - and prone to all
sorts of symbol conflicts when more than ___emutls_get_address is
involved.
=====
I'm afraid I'm out of my depth here.... gcc has quite a learning
curve...
... is the problem one of SPECs ?
.. or does every single TLS case need a darwin-specific addition to
reference -lgcc_eh ?
.. I guess also that target-supports.exp would need some modification
to account for this...
cheers,
Iain
