[cmake-developers] [CMake 0013843]: FindMPI doesn't set MPI_C_LINK_FLAGS or MPI_C_COMPILE_FLAGS (and same for CXX)

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
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http://public.kitware.com/Bug/view.php?id=13843 
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Reported By:                jgu
Assigned To:                
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Project:                    CMake
Issue ID:                   13843
Category:                   Modules
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
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Date Submitted:             2013-01-10 07:01 EST
Last Modified:              2013-01-10 07:01 EST
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Summary:                    FindMPI doesn't set MPI_C_LINK_FLAGS or
MPI_C_COMPILE_FLAGS (and same for CXX)
Description: 
I have a project which does a find_package(MPI). I use the following snippet to
print out all variables:

get_cmake_property(_variableNames VARIABLES)
foreach (_variableName ${_variableNames})
   message(STATUS "${_variableName}=${${_variableName}}")
endforeach()

which produces for the MPI relevant variables:

-- MPIEXEC=/usr/lib64/openmpi/bin/mpiexec
-- MPIEXEC_MAX_NUMPROCS=2
-- MPIEXEC_NUMPROC_FLAG=-np
-- MPIEXEC_POSTFLAGS=
-- MPIEXEC_PREFLAGS=
-- MPI_COMPILER=/usr/lib64/openmpi/bin/mpicxx
-- MPI_COMPILER_IS_EXECUTABLE=0
-- MPI_CXX_COMPILER=/usr/lib64/openmpi/bin/mpicxx
-- MPI_CXX_COMPILE_FLAGS=
-- MPI_CXX_FOUND=TRUE
-- MPI_CXX_INCLUDE_PATH=/usr/include/openmpi-x86_64
--
MPI_CXX_LIBRARIES=/usr/lib64/openmpi/lib/libmpi_cxx.so;/usr/lib64/openmpi/lib/libmpi.so;/usr/lib64/libdl.so
-- MPI_CXX_LINK_FLAGS=
-- MPI_C_COMPILER=/usr/lib64/openmpi/bin/mpicc
-- MPI_C_COMPILE_FLAGS=
-- MPI_C_FOUND=TRUE
-- MPI_C_INCLUDE_PATH=/usr/include/openmpi-x86_64
-- MPI_C_LIBRARIES=/usr/lib64/openmpi/lib/libmpi.so;/usr/lib64/libdl.so
-- MPI_C_LINK_FLAGS=
-- MPI_EXTRA_LIBRARY=/usr/lib64/openmpi/lib/libmpi.so;/usr/lib64/libdl.so
-- MPI_EXTRA_LIBRARY_WORK=/usr/lib64/openmpi/lib/libmpi.so;/usr/lib64/libdl.so
-- MPI_FOUND=TRUE
-- MPI_HEADER_PATH=MPI_HEADER_PATH-NOTFOUND
-- MPI_INCLUDE_PATH=/usr/include/openmpi-x86_64
-- MPI_LIB=MPI_LIB-NOTFOUND
--
MPI_LIBRARIES=/usr/lib64/openmpi/lib/libmpi_cxx.so;/usr/lib64/openmpi/lib/libmpi.so;/usr/lib64/libdl.so
-- MPI_LIBRARY=/usr/lib64/openmpi/lib/libmpi_cxx.so
-- MPI_LIBRARY_WORK=/usr/lib64/openmpi/lib/libmpi_cxx.so
-- MPI_NUMLIBS=3
-- MpiPackageDir=

which shows empty MPI_C_LINK_FLAGS and MPI_C_COMPILE_FLAGS and the same for the
equivalent CXX variables. As a result, even though my project has this:

set_target_properties(myexec PROPERTIES
  COMPILE_FLAGS "${MPI_C_COMPILE_FLAGS}"
  COMPILE_DEFINITIONS "BUILD_WITH_MPI"
  LINK_FLAGS "${MPI_C_LINK_FLAGS}"
)

it fails to link against mpi (-lmpi is missing, for a start).

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Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2013-01-10 07:01 jgu            New Issue                                    
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