C++ programs do not compile with libfabric 1.9.0

[joerns]

Upgrading from libfabric 1.7 to 1.9 I notice that C++ programs including libfabric headers do not compile anymore. Consider this test program:

$ cat test.c
#include "rdma/fabric.h"
#include "rdma/fi_atomic.h"
#include "rdma/fi_cm.h"
#include "rdma/fi_collective.h"
#include "rdma/fi_domain.h"
#include "rdma/fi_endpoint.h"
#include "rdma/fi_eq.h"
#include "rdma/fi_errno.h"
#include "rdma/fi_rma.h"
#include "rdma/fi_tagged.h"
#include "rdma/fi_trigger.h"

int main()
{}

This will compile with gcc:

$ gcc test.c -o out-c -I /path/to/libfabric-1.9.0/include
$

But not with g++:

$ g++ test.c -o out-cpp -I /path/to/libfabric-1.9.0/include
In file included from /afs/cern.ch/work/j/joschuma/git/felix/external/libfabric/1.9.0/x86_64-centos7-gcc8-opt/include/rdma/fi_endpoint.h:37,
                 from /afs/cern.ch/work/j/joschuma/git/felix/external/libfabric/1.9.0/x86_64-centos7-gcc8-opt/include/rdma/fi_atomic.h:37,
                 from test.c:2:
/afs/cern.ch/work/j/joschuma/git/felix/external/libfabric/1.9.0/x86_64-centos7-gcc8-opt/include/rdma/fi_domain.h:206:8: error: use of enum ‘fi_collective_op’ without previous declaration
 enum   fi_collective_op;
        ^~~~~~~~~~~~~~~~
/afs/cern.ch/work/j/joschuma/git/felix/external/libfabric/1.9.0/x86_64-centos7-gcc8-opt/include/rdma/fi_domain.h:231:58: error: use of enum ‘fi_collective_op’ without previous declaration
  int (*query_collective)(struct fid_domain *domain, enum fi_collective_op coll,
                                                          ^~~~~~~~~~~~~~~~     

I think you can't forward-declare an enum and need to put the full declaration there.

I am using gcc 8.3.

Thanks, Jörn

[shefty]

This should be fixed in the upstream master. I'll check that the fix was picked into the 1.9.x branch.

[shefty]

The fix was cherry-picked. It won't be available until we release 1.10 or 1.9.1, however.

[joerns]

Thanks Sean, I'll wait for the new release then 👍