On 10 Dec 2008, at 19:05, Jack Howarth wrote:
On Wed, Dec 10, 2008 at 06:23:18PM +0000, IainS wrote:
On 10 Dec 2008, at 18:10, Mike Stump wrote:
On Dec 10, 2008, at 9:43 AM, Jack Howarth wrote:
If I now understand correctly, the symbols present in updated
versions of
libgcc that are not in the "stock" system libgcc on darwin - need
to be
mentioned in the stub libraries (ligcc_s.10.{4,5,...} ). The
emutls ones
were not present causing linkage failures that were silently
UNSUPPORTING
a lot of tests.
No, those files are meant to describe what was shipped in the
past on
darwin as part of darwin. So, changing them isn't quite the
right way
to do this. Best to put them in the libgcc.a file and let them
link in
statically. Is there some reason why this doesn't work? I can
answer
questions and offer advice, feel free to cc me.
thanks MIke,
the basic issue is that TLS (as used extensively within gomp) is
implemented, at present, as an emulation (emutls).
This is present in libgcc_s.1.dylib and libgcc_eh.a
However, as Jack says, it seems currently very difficult to
persuade gcc
to extract symbols from this un-versioned lib (without mentioning it
specifically on the CL)
Whilst this is a possible work-around for getting the test suite to
work, it concerns me that it's quite obscure and prone to being
missed
out, forgotten, and/or fragile.
There is an added inconvenience in that darwin8's ld command behaves
differently from darwin9's
the only work-around I've found that gives equal results on d8 and
d9 is
to specify -lgcc_eh
these approaches seem like temporary hacks .. and I wonder what a
good
long-term solution would be?
cheers,
Iain
Iain,
I know we have...
if [istarget *-*-darwin*] {
lappend ALWAYS_CFLAGS "additional_flags=-shared-libgcc"
}
in libgomp/testsuite/lib/libgomp.exp. So you have to make sure
that gets overridden if you wan to use --static-libgcc.
This change was discussed here...
http://gcc.gnu.org/ml/gcc-patches/2007-03/msg01497.html
Jack
Yes, that's understood. However:
--static-libgcc does not work (any more, if it used to) with D8
(unless you install the compiler before make check).
libgomp.1.dylib => libgcc_s.1.dylib and D8's ld command objects.
I already commented that if you do --static-libgcc with D9 then
libgomp -> libgcc_s.1
mainline -> statically linked with libgcc.a
this doesn't seem a good idea.
using libgcc_eh.a minimises this (in the case of the libgomp tests)
because the only symbols that happen to be sourced are the __emutls
ones.
However, that's not a general case.
=-----
I suppose I'd expected the current *compiler* symbols to take
precedence over the system ones (unless I specifically demand that
the linked binary is usable w/out delivering the updated runtimes).
For any of this to be useful to an end-user we must accept that the
libgfortran/libgomp .. etc etc. runtimes would have to be installed
on the end-user's system (since they are not currently part of any D8/
D9 system).
`pologies, if I'm being slow... there is a large learning curve here...
cheers,
Iain
