[CMake] MPI: Undefined symbol

[Florian Lindner]

Hello,

Am 20.08.18 um 17:49 schrieb Rafael Sadowski:
> On Mon Aug 20, 2018 at 04:24:07PM +0200, Florian Lindner wrote:
>> Hello,
>>
>> copied from a working MPI CMakeLists.txt:
>>
>> find_package(MPI REQUIRED)
> 
> https://cmake.org/cmake/help/v3.0/module/FindMPI.html
> 
> MPI_<lang>_FOUND           TRUE if FindMPI found MPI flags for <lang>
> MPI_<lang>_COMPILER        MPI Compiler wrapper for <lang>
> MPI_<lang>_COMPILE_FLAGS   Compilation flags for MPI programs
> MPI_<lang>_INCLUDE_PATH    Include path(s) for MPI header
> MPI_<lang>_LINK_FLAGS      Linking flags for MPI programs
> MPI_<lang>_LIBRARIES       All libraries to link MPI programs against
> 
> Looks like you forgot <lang>.

Should also work, versions without LANG are deprecated, but still supported.

But still, I didn't know about the new version and updated my cmake file, but still getting the same error.

find_package(MPI REQUIRED
  COMPONENTS CXX)
include_directories(${MPI_CXX_INCLUDE_DIRS})
set(COMPILE_OPTIONS  ${COMPILE_FLAGS} ${MPI_CXX_COMPILE_OPTIONS})
set(LINK_FLAGS ${LINK_FLAGS} ${MPI_CXX_LINK_FLAGS})
add_definitions(${MPI_CXX_COMPILE_DEFINTIONS})

add_executable(StructureSolverParallel
  "StructureSolver_Parallel/structureDataDisplay.cpp"
  "StructureSolver_Parallel/StructureSolver.cpp"
  "StructureSolver_Parallel/structureComputeSolution.cpp")

target_link_libraries(StructureSolverParallel PUBLIC ${MPI_CXX_LBRARIES})


[ 61%] Building CXX object CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/structureComputeSolution.cpp.o
/usr/bin/c++   -I/home/lindnefn/precice/src -I/opt/mpich/include  -Wall -Wextra -Wno-unused-parameter -g   -std=gnu++11 -o CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/structureComputeSolution.cpp.o -c /home/lindnefn/devel/elastictube1d/StructureSolver_Parallel/structureComputeSolution.cpp

[ 69%] Linking CXX executable StructureSolverParallel
/usr/bin/cmake -E cmake_link_script CMakeFiles/StructureSolverParallel.dir/link.txt --verbose=1
/usr/bin/c++   -Wall -Wextra -Wno-unused-parameter -g   CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/structureDataDisplay.cpp.o CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/StructureSolver.cpp.o CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/structureComputeSolution.cpp.o  -o StructureSolverParallel /home/lindnefn/precice/build/last/libprecice.so

/usr/bin/ld: CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/StructureSolver.cpp.o: undefined reference to symbol 'MPI_Init'
/usr/bin/ld: /opt/mpich/lib/libmpi.so.12: error adding symbols: DSO missing from command line

It doesn't seem to put the MPI_CXX_LIBRARIES at the end. Again, just adding -lmpi to the final command does the trick.

Putting message(${MPI_CXX_LIBRARIES}) after the MPI block returns:

/opt/mpich/lib/libmpicxx.so/opt/mpich/lib/libmpi.so

Any more ideas?

Thanks,
Florian


> 
>> include_directories(${MPI_INCLUDE_PATH})
>> set(COMPILE_FLAGS  ${COMPILE_FLAGS} ${MPI_COMPILE_FLAGS})
>> set(LINK_FLAGS ${LINK_FLAGS} ${MPI_LINK_FLAGS})
>>
>>
>> add_executable(StructureSolverParallel
>>   "StructureSolver_Parallel/structureDataDisplay.cpp"
>>   "StructureSolver_Parallel/StructureSolver.cpp"
>>   "StructureSolver_Parallel/structureComputeSolution.cpp")
>>
>> target_link_libraries(StructureSolverParallel PUBLIC ${PRECICE_LIBRARY})
>> target_link_libraries(StructureSolverParallel PUBLIC ${MPI_LBRARIES})
>>
>> configuration runs smooth:
>>
>> % cmake -DMPI_CXX_COMPILER=/opt/mpich/bin/mpicxx -DMPI_C_COMPILER=/opt/mpich/bin/mpicc . && make               
>> -- The CXX compiler identification is GNU 8.2.0
>> [...]
>> -- Found MPI_CXX: /opt/mpich/lib/libmpicxx.so (found version "3.1") 
>> -- Found MPI: TRUE (found version "3.1")  
>>
>> make however:
>>
>> [ 69%] Linking CXX executable StructureSolverParallel
>> /usr/bin/cmake -E cmake_link_script CMakeFiles/StructureSolverParallel.dir/link.txt --verbose=1
>> /usr/bin/c++   -Wall -Wextra -Wno-unused-parameter -g   CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/structureDataDisplay.cpp.o CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/StructureSolver.cpp.o CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/structureComputeSolution.cpp.o  -o StructureSolverParallel /home/lindnefn/precice/build/last/libprecice.so 
>> /usr/bin/ld: CMakeFiles/StructureSolverParallel.dir/StructureSolver_Parallel/StructureSolver.cpp.o: undefined reference to symbol 'MPI_Init'
>> /usr/bin/ld: /opt/mpich/lib/libmpi.so.12: error adding symbols: DSO missing from command line
>>
>> when I just take the last command line and -lmpi to it, it works.
>>
>> What could be missing there in CMakeLists?
>>
>> Thanks,
>> Florian
>>
>> -- 
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