Ralf Wildenhues wrote:
Hello everybody,
This topic starts here:
http://www.lam-mpi.org/MailArchives/lam/2005/11/11516.php
http://www.lam-mpi.org/MailArchives/lam/2005/11/11519.php
* Jack Howarth wrote on Fri, Nov 18, 2005 at 05:28:07AM CET:
I found a description of the problem I was seeing with the
mpi enabled gromacs 3.3 build on MacOS X 10.4 in the following
message...
http://gcc.gnu.org/ml/gcc/2005-06/msg00186.html
Using their suggestion, I patched gromacs as follows...
+LIBS = @LIBS@ -Wl,-single_module
which causes the linkage of libgmx_mpi.4.dylib to avoid the -multi-module
default. However the lam developers may want to look carefully at the
to see if the problem can be avoided in future releases of gromacs without
resorting to this hack.
Libtool currently adds -single_module for C++ code only. I guess we
should do that for Fortran as well. What do you think?
A test for this in CVS HEAD would be cool, too..
Hi Ralf, Jack.
When libtool is used to build shared libraries on darwin it pases the
-fno-common flag to gcc. It is possible that Jack is trying to link a static
library into a shared one, and the static library has common symbols. The
solution is to rebuild the static library with -fno-common. Another solution
is to initialize all variables in the static library before they are used,
the rebuild it. e.g. write int foo=0; instead of int foo;
-single_module is only there for c++ because on Mac OS X 10.3 and earlier
the dynamic linker would not call static initializers in tranlation units
which did not have any other symbols referenced. It is not the default
because nobody has persuaded me that making your shared library much more
difficult to debug is worth whatever gain the -single_module flag gives.
Peter
