[petsc-dev] OpenMPI && petsc-2.3.3-p15

[Harald Pfeiffer]

Hi,

to add another data-point to this discussion:  I found that adding 
-DMPI_SKIP_MPICXX  dramatically reduces the number of compiler warnings 
arising from OpenMPI-code.

Without doing this, the important compiler warnings about my own code 
get lost in the noise. Examples with and without -DOMPI_SKIP_MPICXX 
below (coincidentally, this example triggers a warning on Petsc code).

Cheers,
Harald




WITH -DOMPI_SKIP_MPICXX


[pfeiffer at bee EllipticSolver]$ make -s
========== compile EllipticSolverCore.cpp
In file included from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petsc.h:1796,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscis.h:7,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscvec.h:9,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscmat.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscpc.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscksp.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscsnes.h:6,
                  from 
/scratch/pfeiffer/SpEC/gccO/Elliptic/EllipticResidual/Petsc.hpp:8,
                  from 
/scratch/pfeiffer/SpEC/gccO/Elliptic/Preconditioning/Preconditioner.hpp:13,
                  from EllipticSolverCore.hpp:11,
                  from EllipticSolverCore.cpp:9:
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petsc.hh: In 
constructor ‘PETSc::Exception::Exception(const std::string&)’:
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petsc.hh:10: warning: 
declaration of ‘msg’ shadows a member of 'this'




WITHOUT -DOMPI_SKIP_MPICXX:




[pfeiffer at bee EllipticSolver]$ make -s
========== compile EllipticSolverCore.cpp
In file included from 
/usr/include/openmpi/1.2.4-gcc/openmpi/ompi/mpi/cxx/mpicxx.h:246,
                  from /usr/include/openmpi/1.2.4-gcc/mpi.h:1783,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petsc.h:137,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscis.h:7,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscvec.h:9,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscmat.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscpc.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscksp.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscsnes.h:6,
                  from 
/scratch/pfeiffer/SpEC/gccO/Elliptic/EllipticResidual/Petsc.hpp:8,
                  from 
/scratch/pfeiffer/SpEC/gccO/Elliptic/Preconditioning/Preconditioner.hpp:13,
                  from EllipticSolverCore.hpp:11,
                  from EllipticSolverCore.cpp:9:
/usr/include/openmpi/1.2.4-gcc/openmpi/ompi/mpi/cxx/request_inln.h: In 
static member function ‘static MPI::Grequest MPI::Grequest::Start(int 
(*)(void*, MPI::Status&), int (*)(void*), int (*)(void*, bool), void*)’:
/usr/include/openmpi/1.2.4-gcc/openmpi/ompi/mpi/cxx/request_inln.h:347: 
warning: declaration ‘struct MPI::Grequest_intercept_t’ does not declare 
anything
In file included from 
/usr/include/openmpi/1.2.4-gcc/openmpi/ompi/mpi/cxx/mpicxx.h:247,
                  from /usr/include/openmpi/1.2.4-gcc/mpi.h:1783,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petsc.h:137,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscis.h:7,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscvec.h:9,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscmat.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscpc.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscksp.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscsnes.h:6,
                  from 
/scratch/pfeiffer/SpEC/gccO/Elliptic/EllipticResidual/Petsc.hpp:8,
                  from 
/scratch/pfeiffer/SpEC/gccO/Elliptic/Preconditioning/Preconditioner.hpp:13,
                  from EllipticSolverCore.hpp:11,
                  from EllipticSolverCore.cpp:9:
/usr/include/openmpi/1.2.4-gcc/openmpi/ompi/mpi/cxx/comm_inln.h: In 
static member function ‘static int MPI::Comm::NULL_COPY_FN(const 
MPI::Comm&, int, void*, void*, void*, bool&)’:
/usr/include/openmpi/1.2.4-gcc/openmpi/ompi/mpi/cxx/comm_inln.h:641: 
warning: the address of ‘int 
OMPI_C_MPI_NULL_COPY_FN(ompi_communicator_t*, int, void*, void*, void*, 
int*)’ will never be NULL
/usr/include/openmpi/1.2.4-gcc/openmpi/ompi/mpi/cxx/comm_inln.h: In 
static member function ‘static int MPI::Comm::NULL_DELETE_FN(MPI::Comm&, 
int, void*, void*)’:
/usr/include/openmpi/1.2.4-gcc/openmpi/ompi/mpi/cxx/comm_inln.h:698: 
warning: the address of ‘int 
OMPI_C_MPI_NULL_DELETE_FN(ompi_communicator_t*, int, void*, void*)’ will 
never be NULL
In file included from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petsc.h:1796,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscis.h:7,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscvec.h:9,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscmat.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscpc.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscksp.h:6,
                  from 
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petscsnes.h:6,
                  from 
/scratch/pfeiffer/SpEC/gccO/Elliptic/EllipticResidual/Petsc.hpp:8,
                  from 
/scratch/pfeiffer/SpEC/gccO/Elliptic/Preconditioning/Preconditioner.hpp:13,
                  from EllipticSolverCore.hpp:11,
                  from EllipticSolverCore.cpp:9:
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petsc.hh: In 
constructor ‘PETSc::Exception::Exception(const std::string&)’:
/scratch/pfeiffer/opt/src/petsc-3.0.0-p9/include/petsc.hh:10: warning: 
declaration of ‘msg’ shadows a member of 'this'





Barry Smith wrote:
> 
>     Eric,
> 
>      Could you describe, preferably with error messages printed by 
> compilers etc, why this is necessary? I read the comment in petsc.h
> 
> 
>     PETSc does not use the C++ binding of MPI at ALL. The following flag
>     makes sure the C++ bindings are not included. The C++ bindings REQUIRE
>     putting mpi.h before ANY C++ include files, we cannot control this
>     with all PETSc users.
> */
> 
> but could not reproduce the problem (I put C++ include files before 
> mpi.h without that flag and everything compiled and ran fine for both 
> MPICH and OpenMPI on my Apple).
> 
> Do we really need the flags. I have no problem putting in the OpenMPI 
> also, but it does mean that PETSc users cannot use the C++ bindings of 
> MPI (which some may want to). So I would like to avoid both flags unless 
> they are really needed.
> 
>    Thanks
> 
>     Barry
> 
> 
> On Jan 6, 2010, at 8:21 AM, Eric Chamberland wrote:
> 
>> Hi,
>>
>> we have compile petsc-2.3.3-p15 with openMPI 1.3.4.  To have it working
>> with our C++ code, I did a "#define OMPI_SKIP_MPICXX".
>>
>> In petsc.h, this is already done but for MPICH, on line #137:
>>
>> #define MPICH_SKIP_MPICXX 1
>>
>> It would be nice to also have a:
>>
>> #define OMPI_SKIP_MPICXX" 1
>>
>> But I don't know if it would be necessery also in petsc release 3.
>>
>> Thank you!
>>
>> Eric