Merge topic 'multilingual-FindMPI'

a55da06 Added backward compatibility for input as well as output vars.
a32a633 FindMPI: Fix documentation formatting
706b73e FindMPI: Handle multiple languages
This commit is contained in:
Brad King 2011-04-26 14:25:10 -04:00 committed by CMake Topic Stage
commit aebf98b4f1
1 changed files with 494 additions and 294 deletions

View File

@ -1,59 +1,70 @@
# - Message Passing Interface (MPI) module. # - Find a Message Passing Interface (MPI) implementation
#
# The Message Passing Interface (MPI) is a library used to write # The Message Passing Interface (MPI) is a library used to write
# high-performance parallel applications that use message passing, and # high-performance distributed-memory parallel applications, and
# is typically deployed on a cluster. MPI is a standard interface # is typically deployed on a cluster. MPI is a standard interface
# (defined by the MPI forum) for which many implementations are # (defined by the MPI forum) for which many implementations are
# available. All of these implementations have somewhat different # available. All of them have somewhat different include paths,
# compilation approaches (different include paths, libraries to link # libraries to link against, etc., and this module tries to smooth
# against, etc.), and this module tries to smooth out those differences. # out those differences.
# #
# This module will set the following variables: # === Variables ===
# MPI_FOUND TRUE if we have found MPI #
# MPI_COMPILE_FLAGS Compilation flags for MPI programs # This module will set the following variables per language in your project,
# MPI_INCLUDE_PATH Include path(s) for MPI header # where <lang> is one of C, CXX, or Fortran:
# MPI_LINK_FLAGS Linking flags for MPI programs # MPI_<lang>_FOUND TRUE if FindMPI found MPI flags for <lang>
# MPI_LIBRARY First MPI library to link against (cached) # MPI_<lang>_COMPILER MPI Compiler wrapper for <lang>
# MPI_EXTRA_LIBRARY Extra MPI libraries to link against (cached) # MPI_<lang>_COMPILE_FLAGS Compilation flags for MPI programs
# MPI_LIBRARIES All libraries to link MPI programs against # 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
# Additionally, FindMPI sets the following variables for running MPI
# programs from the command line:
# MPIEXEC Executable for running MPI programs # MPIEXEC Executable for running MPI programs
# MPIEXEC_NUMPROC_FLAG Flag to pass to MPIEXEC before giving it the # MPIEXEC_NUMPROC_FLAG Flag to pass to MPIEXEC before giving
# number of processors to run on # it the number of processors to run on
# MPIEXEC_PREFLAGS Flags to pass to MPIEXEC directly before the # MPIEXEC_PREFLAGS Flags to pass to MPIEXEC directly
# executable to run. # before the executable to run.
# MPIEXEC_POSTFLAGS Flags to pass to MPIEXEC after all other flags. # MPIEXEC_POSTFLAGS Flags to pass to MPIEXEC after other flags
# === Usage ===
# #
# This module will attempt to auto-detect these settings, first by # To use this module, simply call FindMPI from a CMakeLists.txt file, or
# looking for a MPI compiler, which many MPI implementations provide # run find_package(MPI), then run CMake. If you are happy with the auto-
# as a pass-through to the native compiler to simplify the compilation # detected configuration for your language, then you're done. If not, you
# of MPI programs. The MPI compiler is stored in the cache variable # have two options:
# MPI_COMPILER, and will attempt to look for commonly-named drivers # 1. Set MPI_<lang>_COMPILER to the MPI wrapper (mpicc, etc.) of your
# mpic++, mpicxx, mpiCC, or mpicc. If the compiler driver is found and # choice and reconfigure. FindMPI will attempt to determine all the
# recognized, it will be used to set all of the module variables. To # necessary variables using THAT compiler's compile and link flags.
# skip this auto-detection, set MPI_LIBRARY and MPI_INCLUDE_PATH in # 2. If this fails, or if your MPI implementation does not come with
# the CMake cache. # a compiler wrapper, then set both MPI_<lang>_LIBRARIES and
# MPI_<lang>_INCLUDE_PATH. You may also set any other variables
# listed above, but these two are required. This will circumvent
# autodetection entirely.
# When configuration is successful, MPI_<lang>_COMPILER will be set to the
# compiler wrapper for <lang>, if it was found. MPI_<lang>_FOUND and other
# variables above will be set if any MPI implementation was found for <lang>,
# regardless of whether a compiler was found.
# #
# If no compiler driver is found or the compiler driver is not # When using MPIEXEC to execute MPI applications, you should typically use
# recognized, this module will then search for common include paths # all of the MPIEXEC flags as follows:
# and library names to try to detect MPI. # ${MPIEXEC} ${MPIEXEC_NUMPROC_FLAG} PROCS
# # ${MPIEXEC_PREFLAGS} EXECUTABLE ${MPIEXEC_POSTFLAGS} ARGS
# If CMake initially finds a different MPI than was intended, and you
# want to use the MPI compiler auto-detection for a different MPI
# implementation, set MPI_COMPILER to the MPI compiler driver you want
# to use (e.g., mpicxx) and then set MPI_LIBRARY to the string
# MPI_LIBRARY-NOTFOUND. When you re-configure, auto-detection of MPI
# will run again with the newly-specified MPI_COMPILER.
#
# When using MPIEXEC to execute MPI applications, you should typically
# use all of the MPIEXEC flags as follows:
# ${MPIEXEC} ${MPIEXEC_NUMPROC_FLAG} PROCS ${MPIEXEC_PREFLAGS} EXECUTABLE
# ${MPIEXEC_POSTFLAGS} ARGS
# where PROCS is the number of processors on which to execute the program, # where PROCS is the number of processors on which to execute the program,
# EXECUTABLE is the MPI program, and ARGS are the arguments to pass to the # EXECUTABLE is the MPI program, and ARGS are the arguments to pass to the
# MPI program. # MPI program.
#
# === Backward Compatibility ===
#
# For backward compatibility with older versions of FindMPI, these
# variables are set, but deprecated:
# MPI_FOUND MPI_COMPILER MPI_LIBRARY
# MPI_COMPILE_FLAGS MPI_INCLUDE_PATH MPI_EXTRA_LIBRARY
# MPI_LINK_FLAGS MPI_LIBRARIES
# In new projects, please use the MPI_<lang>_XXX equivalents.
#============================================================================= #=============================================================================
# Copyright 2001-2009 Kitware, Inc. # Copyright 2001-2011 Kitware, Inc.
# Copyright 2010-2011 Todd Gamblin tgamblin@llnl.gov
# Copyright 2001-2009 Dave Partyka
# #
# Distributed under the OSI-approved BSD License (the "License"); # Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details. # see accompanying file Copyright.txt for details.
@ -65,295 +76,484 @@
# (To distribute this file outside of CMake, substitute the full # (To distribute this file outside of CMake, substitute the full
# License text for the above reference.) # License text for the above reference.)
# This module is maintained by David Partyka <dave.partyka@kitware.com>. # include this to handle the QUIETLY and REQUIRED arguments
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
include(GetPrerequisites)
# A set of directories to search through in addition to the standard system paths #
# that find_program will search through. # This part detects MPI compilers, attempting to wade through the mess of compiler names in
# Microsoft HPC SDK is automatically added to the system path # a sensible way.
# Argonne National Labs MPICH2 sets a registry key that we can use. #
# The compilers are detected in this order:
#
# 1. Try to find the most generic availble MPI compiler, as this is usually set up by
# cluster admins. e.g., if plain old mpicc is available, we'll use it and assume it's
# the right compiler.
#
# 2. If a generic mpicc is NOT found, then we attempt to find one that matches
# CMAKE_<lang>_COMPILER_ID. e.g. if you are using XL compilers, we'll try to find mpixlc
# and company, but not mpiicc. This hopefully prevents toolchain mismatches.
#
# If you want to force a particular MPI compiler other than what we autodetect (e.g. if you
# want to compile regular stuff with GNU and parallel stuff with Intel), you can always set
# your favorite MPI_<lang>_COMPILER explicitly and this stuff will be ignored.
#
set(_MPI_PACKAGE_DIR # Start out with the generic MPI compiler names, as these are most commonly used.
mpi set(_MPI_C_COMPILER_NAMES mpicc mpcc mpicc_r mpcc_r)
mpich set(_MPI_CXX_COMPILER_NAMES mpicxx mpiCC mpcxx mpCC mpic++ mpc++
openmpi mpicxx_r mpiCC_r mpcxx_r mpCC_r mpic++_r mpc++_r)
lib/mpi set(_MPI_Fortran_COMPILER_NAMES mpif95 mpif95_r mpf95 mpf95_r
lib/mpich mpif90 mpif90_r mpf90 mpf90_r
lib/openmpi mpif77 mpif77_r mpf77 mpf77_r)
"MPICH/SDK"
"Microsoft Compute Cluster Pack"
"Microsoft HPC Pack 2008 R2"
)
# GNU compiler names
set(_MPI_GNU_C_COMPILER_NAMES mpigcc mpgcc mpigcc_r mpgcc_r)
set(_MPI_GNU_CXX_COMPILER_NAMES mpig++ mpg++ mpig++_r mpg++_r)
set(_MPI_GNU_Fortran_COMPILER_NAMES mpigfortran mpgfortran mpigfortran_r mpgfortran_r
mpig77 mpig77_r mpg77 mpg77_r)
# Intel MPI compiler names
set(_MPI_Intel_C_COMPILER_NAMES mpiicc)
set(_MPI_Intel_CXX_COMPILER_NAMES mpiicpc mpiicxx mpiic++ mpiiCC)
set(_MPI_Intel_Fortran_COMPILER_NAMES mpiifort mpiif95 mpiif90 mpiif77)
# PGI compiler names
set(_MPI_PGI_C_COMPILER_NAMES mpipgcc mppgcc)
set(_MPI_PGI_CXX_COMPILER_NAMES mpipgCC mppgCC)
set(_MPI_PGI_Fortran_COMPILER_NAMES mpipgf95 mpipgf90 mppgf95 mppgf90 mpipgf77 mppgf77)
# XLC MPI Compiler names
set(_MPI_XL_C_COMPILER_NAMES mpxlc mpxlc_r mpixlc mpixlc_r)
set(_MPI_XL_CXX_COMPILER_NAMES mpixlcxx mpixlC mpixlc++ mpxlcxx mpxlc++ mpixlc++ mpxlCC
mpixlcxx_r mpixlC_r mpixlc++_r mpxlcxx_r mpxlc++_r mpixlc++_r mpxlCC_r)
set(_MPI_XL_Fortran_COMPILER_NAMES mpixlf95 mpixlf95_r mpxlf95 mpxlf95_r
mpixlf90 mpixlf90_r mpxlf90 mpxlf90_r
mpixlf77 mpixlf77_r mpxlf77 mpxlf77_r
mpixlf mpixlf_r mpxlf mpxlf_r)
# append vendor-specific compilers to the list if we either don't know the compiler id,
# or if we know it matches the regular compiler.
foreach (lang C CXX Fortran)
foreach (id GNU Intel PGI XL)
if (NOT CMAKE_${lang}_COMPILER_ID OR "${CMAKE_${lang}_COMPILER_ID}" STREQUAL "${id}")
list(APPEND _MPI_${lang}_COMPILER_NAMES ${_MPI_${id}_${lang}_COMPILER_NAMES})
endif()
unset(_MPI_${id}_${lang}_COMPILER_NAMES) # clean up the namespace here
endforeach()
endforeach()
# Names to try for MPI exec
set(_MPI_EXEC_NAMES mpiexec mpirun lamexec srun)
# Grab the path to MPI from the registry if we're on windows.
set(_MPI_PREFIX_PATH) set(_MPI_PREFIX_PATH)
if(WIN32) if(WIN32)
list(APPEND _MPI_PREFIX_PATH "[HKEY_LOCAL_MACHINE\\SOFTWARE\\MPICH\\SMPD;binary]/..") list(APPEND _MPI_PREFIX_PATH "[HKEY_LOCAL_MACHINE\\SOFTWARE\\MPICH\\SMPD;binary]/..")
list(APPEND _MPI_PREFIX_PATH "[HKEY_LOCAL_MACHINE\\SOFTWARE\\MPICH2;Path]") list(APPEND _MPI_PREFIX_PATH "[HKEY_LOCAL_MACHINE\\SOFTWARE\\MPICH2;Path]")
list(APPEND _MPI_PREFIX_PATH "$ENV{ProgramW6432}/MPICH2/")
endif() endif()
# Build a list of prefixes to search for MPI.
foreach(SystemPrefixDir ${CMAKE_SYSTEM_PREFIX_PATH}) foreach(SystemPrefixDir ${CMAKE_SYSTEM_PREFIX_PATH})
foreach(MpiPackageDir ${_MPI_PREFIX_PATH}) foreach(MpiPackageDir ${_MPI_PREFIX_PATH})
if(EXISTS ${SystemPrefixDir}/${MpiPackageDir}) if(EXISTS ${SystemPrefixDir}/${MpiPackageDir})
list(APPEND _MPI_PREFIX_PATH "${SystemPrefixDir}/${MpiPackageDir}") list(APPEND _MPI_PREFIX_PATH "${SystemPrefixDir}/${MpiPackageDir}")
endif() endif()
endforeach(MpiPackageDir) endforeach()
endforeach(SystemPrefixDir) endforeach()
#
# interrogate_mpi_compiler(lang try_libs)
#
# Attempts to extract compiler and linker args from an MPI compiler. The arguments set
# by this function are:
#
# MPI_<lang>_INCLUDE_PATH MPI_<lang>_LINK_FLAGS MPI_<lang>_FOUND
# MPI_<lang>_COMPILE_FLAGS MPI_<lang>_LIBRARIES
#
# MPI_<lang>_COMPILER must be set beforehand to the absolute path to an MPI compiler for
# <lang>. Additionally, MPI_<lang>_INCLUDE_PATH and MPI_<lang>_LIBRARIES may be set
# to skip autodetection.
#
# If try_libs is TRUE, this will also attempt to find plain MPI libraries in the usual
# way. In general, this is not as effective as interrogating the compilers, as it
# ignores language-specific flags and libraries. However, some MPI implementations
# (Windows implementations) do not have compiler wrappers, so this approach must be used.
#
function (interrogate_mpi_compiler lang try_libs)
# if it's already in the cache, don't bother with any of this stuff
if ((NOT MPI_${lang}_INCLUDE_PATH) OR (NOT MPI_${lang}_LIBRARIES))
if (MPI_${lang}_COMPILER)
# Check whether the -showme:compile option works. This indicates that we have either OpenMPI
# or a newer version of LAM-MPI, and implies that -showme:link will also work.
execute_process(
COMMAND ${MPI_${lang}_COMPILER} -showme:compile
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE MPI_COMPILE_CMDLINE ERROR_STRIP_TRAILING_WHITESPACE
RESULT_VARIABLE MPI_COMPILER_RETURN)
if (MPI_COMPILER_RETURN EQUAL 0)
# If we appear to have -showme:compile, then we should
# also have -showme:link. Try it.
execute_process(
COMMAND ${MPI_${lang}_COMPILER} -showme:link
OUTPUT_VARIABLE MPI_LINK_CMDLINE OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE MPI_LINK_CMDLINE ERROR_STRIP_TRAILING_WHITESPACE
RESULT_VARIABLE MPI_COMPILER_RETURN)
if (MPI_COMPILER_RETURN EQUAL 0)
# We probably have -showme:incdirs and -showme:libdirs as well,
# so grab that while we're at it.
execute_process(
COMMAND ${MPI_${lang}_COMPILER} -showme:incdirs
OUTPUT_VARIABLE MPI_INCDIRS OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE MPI_INCDIRS ERROR_STRIP_TRAILING_WHITESPACE)
execute_process(
COMMAND ${MPI_${lang}_COMPILER} -showme:libdirs
OUTPUT_VARIABLE MPI_LIBDIRS OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE MPI_LIBDIRS ERROR_STRIP_TRAILING_WHITESPACE)
else()
# reset things here if something went wrong.
set(MPI_COMPILE_CMDLINE)
set(MPI_LINK_CMDLINE)
endif()
endif ()
# Older versions of LAM-MPI have "-showme". Try to find that.
if (NOT MPI_COMPILER_RETURN EQUAL 0)
execute_process(
COMMAND ${MPI_${lang}_COMPILER} -showme
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE MPI_COMPILE_CMDLINE ERROR_STRIP_TRAILING_WHITESPACE
RESULT_VARIABLE MPI_COMPILER_RETURN)
endif()
# MVAPICH uses -compile-info and -link-info. Try them.
if (NOT MPI_COMPILER_RETURN EQUAL 0)
execute_process(
COMMAND ${MPI_${lang}_COMPILER} -compile-info
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE MPI_COMPILE_CMDLINE ERROR_STRIP_TRAILING_WHITESPACE
RESULT_VARIABLE MPI_COMPILER_RETURN)
# If we have compile-info, also have link-info.
if (MPI_COMPILER_RETURN EQUAL 0)
execute_process(
COMMAND ${MPI_${lang}_COMPILER} -link-info
OUTPUT_VARIABLE MPI_LINK_CMDLINE OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE MPI_LINK_CMDLINE ERROR_STRIP_TRAILING_WHITESPACE
RESULT_VARIABLE MPI_COMPILER_RETURN)
endif()
# make sure we got compile and link. Reset vars if something's wrong.
if (NOT MPI_COMPILER_RETURN EQUAL 0)
set(MPI_COMPILE_CMDLINE)
set(MPI_LINK_CMDLINE)
endif()
endif()
# MPICH just uses "-show". Try it.
if (NOT MPI_COMPILER_RETURN EQUAL 0)
execute_process(
COMMAND ${MPI_${lang}_COMPILER} -show
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE MPI_COMPILE_CMDLINE ERROR_STRIP_TRAILING_WHITESPACE
RESULT_VARIABLE MPI_COMPILER_RETURN)
endif()
if (MPI_COMPILER_RETURN EQUAL 0)
# We have our command lines, but we might need to copy MPI_COMPILE_CMDLINE
# into MPI_LINK_CMDLINE, if we didn't find the link line.
if (NOT MPI_LINK_CMDLINE)
set(MPI_LINK_CMDLINE ${MPI_COMPILE_CMDLINE})
endif()
else()
message(STATUS "Unable to determine MPI from MPI driver ${MPI_${lang}_COMPILER}")
set(MPI_COMPILE_CMDLINE)
set(MPI_LINK_CMDLINE)
endif()
# Here, we're done with the interrogation part, and we'll try to extract args we care
# about from what we learned from the compiler wrapper scripts.
# If interrogation came back with something, extract our variable from the MPI command line
if (MPI_COMPILE_CMDLINE OR MPI_LINK_CMDLINE)
# Extract compile flags from the compile command line.
string(REGEX MATCHALL "(^| )-[Df]([^\" ]+|\"[^\"]+\")" MPI_ALL_COMPILE_FLAGS "${MPI_COMPILE_CMDLINE}")
set(MPI_COMPILE_FLAGS_WORK)
foreach(FLAG ${MPI_ALL_COMPILE_FLAGS})
if (MPI_COMPILE_FLAGS_WORK)
set(MPI_COMPILE_FLAGS_WORK "${MPI_COMPILE_FLAGS_WORK} ${FLAG}")
else()
set(MPI_COMPILE_FLAGS_WORK ${FLAG})
endif()
endforeach()
# Extract include paths from compile command line
string(REGEX MATCHALL "(^| )-I([^\" ]+|\"[^\"]+\")" MPI_ALL_INCLUDE_PATHS "${MPI_COMPILE_CMDLINE}")
foreach(IPATH ${MPI_ALL_INCLUDE_PATHS})
string(REGEX REPLACE "^ ?-I" "" IPATH ${IPATH})
string(REGEX REPLACE "//" "/" IPATH ${IPATH})
list(APPEND MPI_INCLUDE_PATH_WORK ${IPATH})
endforeach()
# try using showme:incdirs if extracting didn't work.
if (NOT MPI_INCLUDE_PATH_WORK)
set(MPI_INCLUDE_PATH_WORK ${MPI_INCDIRS})
separate_arguments(MPI_INCLUDE_PATH_WORK)
endif()
# If all else fails, just search for mpi.h in the normal include paths.
if (NOT MPI_INCLUDE_PATH_WORK)
set(MPI_HEADER_PATH "MPI_HEADER_PATH-NOTFOUND" CACHE FILEPATH "Cleared" FORCE)
find_path(MPI_HEADER_PATH mpi.h
HINTS ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH}
PATH_SUFFIXES include)
set(MPI_INCLUDE_PATH_WORK ${MPI_HEADER_PATH})
endif()
# Extract linker paths from the link command line
string(REGEX MATCHALL "(^| |-Wl,)-L([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_PATHS "${MPI_LINK_CMDLINE}")
set(MPI_LINK_PATH)
foreach(LPATH ${MPI_ALL_LINK_PATHS})
string(REGEX REPLACE "^(| |-Wl,)-L" "" LPATH ${LPATH})
string(REGEX REPLACE "//" "/" LPATH ${LPATH})
list(APPEND MPI_LINK_PATH ${LPATH})
endforeach()
# try using showme:libdirs if extracting didn't work.
if (NOT MPI_LINK_PATH)
set(MPI_LINK_PATH ${MPI_LIBDIRS})
separate_arguments(MPI_LINK_PATH)
endif()
# Extract linker flags from the link command line
string(REGEX MATCHALL "(^| )-Wl,([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_FLAGS "${MPI_LINK_CMDLINE}")
set(MPI_LINK_FLAGS_WORK)
foreach(FLAG ${MPI_ALL_LINK_FLAGS})
if (MPI_LINK_FLAGS_WORK)
set(MPI_LINK_FLAGS_WORK "${MPI_LINK_FLAGS_WORK} ${FLAG}")
else()
set(MPI_LINK_FLAGS_WORK ${FLAG})
endif()
endforeach()
# Extract the set of libraries to link against from the link command
# line
string(REGEX MATCHALL "(^| )-l([^\" ]+|\"[^\"]+\")" MPI_LIBNAMES "${MPI_LINK_CMDLINE}")
# Determine full path names for all of the libraries that one needs
# to link against in an MPI program
foreach(LIB ${MPI_LIBNAMES})
string(REGEX REPLACE "^ ?-l" "" LIB ${LIB})
# MPI_LIB is cached by find_library, but we don't want that. Clear it first.
set(MPI_LIB "MPI_LIB-NOTFOUND" CACHE FILEPATH "Cleared" FORCE)
find_library(MPI_LIB NAMES ${LIB} HINTS ${MPI_LINK_PATH})
if (MPI_LIB)
list(APPEND MPI_LIBRARIES_WORK ${MPI_LIB})
elseif (NOT MPI_FIND_QUIETLY)
message(WARNING "Unable to find MPI library ${LIB}")
endif()
endforeach()
# Sanity check MPI_LIBRARIES to make sure there are enough libraries
list(LENGTH MPI_LIBRARIES_WORK MPI_NUMLIBS)
list(LENGTH MPI_LIBNAMES MPI_NUMLIBS_EXPECTED)
if (NOT MPI_NUMLIBS EQUAL MPI_NUMLIBS_EXPECTED)
set(MPI_LIBRARIES_WORK "MPI_${lang}_LIBRARIES-NOTFOUND")
endif()
endif()
elseif(try_libs)
# If we didn't have an MPI compiler script to interrogate, attempt to find everything
# with plain old find functions. This is nasty because MPI implementations have LOTS of
# different library names, so this section isn't going to be very generic. We need to
# make sure it works for MS MPI, though, since there are no compiler wrappers for that.
find_path(MPI_HEADER_PATH mpi.h
HINTS ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH}
PATH_SUFFIXES include Inc)
set(MPI_INCLUDE_PATH_WORK ${MPI_HEADER_PATH})
# Decide between 32-bit and 64-bit libraries for Microsoft's MPI
if("${CMAKE_SIZEOF_VOID_P}" EQUAL 8)
set(MS_MPI_ARCH_DIR amd64)
else()
set(MS_MPI_ARCH_DIR i386)
endif()
set(MPI_LIB "MPI_LIB-NOTFOUND" CACHE FILEPATH "Cleared" FORCE)
find_library(MPI_LIB
NAMES mpi mpich mpich2 msmpi
HINTS ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH}
PATH_SUFFIXES lib lib/${MS_MPI_ARCH_DIR} Lib Lib/${MS_MPI_ARCH_DIR})
set(MPI_LIBRARIES_WORK ${MPI_LIB})
# Right now, we only know about the extra libs for C++.
# We could add Fortran here (as there is usually libfmpich, etc.), but
# this really only has to work with MS MPI on Windows.
# Assume that other MPI's are covered by the compiler wrappers.
if (${lang} STREQUAL CXX)
set(MPI_LIB "MPI_LIB-NOTFOUND" CACHE FILEPATH "Cleared" FORCE)
find_library(MPI_LIB
NAMES mpi++ mpicxx cxx mpi_cxx
HINTS ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH}
PATH_SUFFIXES lib)
if (MPI_LIBRARIES_WORK AND MPI_LIB)
set(MPI_LIBRARIES_WORK "${MPI_LIBRARIES_WORK} ${MPI_LIB}")
endif()
endif()
if (NOT MPI_LIBRARIES_WORK)
set(MPI_LIBRARIES_WORK "MPI_${lang}_LIBRARIES-NOTFOUND")
endif()
endif()
# If we found MPI, set up all of the appropriate cache entries
set(MPI_${lang}_COMPILE_FLAGS ${MPI_COMPILE_FLAGS_WORK} CACHE STRING "MPI ${lang} compilation flags" FORCE)
set(MPI_${lang}_INCLUDE_PATH ${MPI_INCLUDE_PATH_WORK} CACHE STRING "MPI ${lang} include path" FORCE)
set(MPI_${lang}_LINK_FLAGS ${MPI_LINK_FLAGS_WORK} CACHE STRING "MPI ${lang} linking flags" FORCE)
set(MPI_${lang}_LIBRARIES ${MPI_LIBRARIES_WORK} CACHE STRING "MPI ${lang} libraries to link against" FORCE)
mark_as_advanced(MPI_${lang}_COMPILE_FLAGS MPI_${lang}_INCLUDE_PATH MPI_${lang}_LINK_FLAGS MPI_${lang}_LIBRARIES)
# clear out our temporary lib/header detectionv variable here.
set(MPI_LIB "MPI_LIB-NOTFOUND" CACHE INTERNAL "Scratch variable for MPI lib detection" FORCE)
set(MPI_HEADER_PATH "MPI_HEADER_PATH-NOTFOUND" CACHE INTERNAL "Scratch variable for MPI header detection" FORCE)
endif()
# finally set a found variable for each MPI language
if (MPI_${lang}_INCLUDE_PATH AND MPI_${lang}_LIBRARIES)
set(MPI_${lang}_FOUND TRUE PARENT_SCOPE)
else()
set(MPI_${lang}_FOUND FALSE PARENT_SCOPE)
endif()
endfunction()
# End definitions, commence real work here.
# Most mpi distros have some form of mpiexec which gives us something we can reliably look for. # Most mpi distros have some form of mpiexec which gives us something we can reliably look for.
find_program(MPIEXEC find_program(MPIEXEC
NAMES mpiexec mpirun lamexec NAMES ${_MPI_EXEC_NAMES}
PATHS ${_MPI_PREFIX_PATH} PATHS ${_MPI_PREFIX_PATH}
PATH_SUFFIXES bin PATH_SUFFIXES bin
DOC "Executable for running MPI programs." DOC "Executable for running MPI programs.")
)
# call get_filename_component twice to remove mpiexec and the directory it exists in (typically bin). # call get_filename_component twice to remove mpiexec and the directory it exists in (typically bin).
# This gives us a fairly reliable base directory to search for /bin /lib and /include from. # This gives us a fairly reliable base directory to search for /bin /lib and /include from.
get_filename_component(_MPI_BASE_DIR "${MPIEXEC}" PATH) get_filename_component(_MPI_BASE_DIR "${MPIEXEC}" PATH)
get_filename_component(_MPI_BASE_DIR "${_MPI_BASE_DIR}" PATH) get_filename_component(_MPI_BASE_DIR "${_MPI_BASE_DIR}" PATH)
# If there is an mpi compiler find it and interogate (farther below) it for the include
# and lib dirs otherwise we will continue to search from ${_MPI_BASE_DIR}.
find_program(MPI_COMPILER
NAMES mpic++ mpicxx mpiCC mpicc
HINTS "${_MPI_BASE_DIR}"
PATH_SUFFIXES bin
DOC "MPI compiler. Used only to detect MPI compilation flags.")
mark_as_advanced(MPI_COMPILER)
set(MPIEXEC_NUMPROC_FLAG "-np" CACHE STRING "Flag used by MPI to specify the number of processes for MPIEXEC; the next option will be the number of processes.") set(MPIEXEC_NUMPROC_FLAG "-np" CACHE STRING "Flag used by MPI to specify the number of processes for MPIEXEC; the next option will be the number of processes.")
set(MPIEXEC_PREFLAGS "" CACHE STRING "These flags will be directly before the executable that is being run by MPIEXEC.") set(MPIEXEC_PREFLAGS "" CACHE STRING "These flags will be directly before the executable that is being run by MPIEXEC.")
set(MPIEXEC_POSTFLAGS "" CACHE STRING "These flags will come after all flags given to MPIEXEC.") set(MPIEXEC_POSTFLAGS "" CACHE STRING "These flags will come after all flags given to MPIEXEC.")
set(MPIEXEC_MAX_NUMPROCS "2" CACHE STRING "Maximum number of processors available to run MPI applications.") set(MPIEXEC_MAX_NUMPROCS "2" CACHE STRING "Maximum number of processors available to run MPI applications.")
mark_as_advanced(MPIEXEC MPIEXEC_NUMPROC_FLAG MPIEXEC_PREFLAGS mark_as_advanced(MPIEXEC MPIEXEC_NUMPROC_FLAG MPIEXEC_PREFLAGS MPIEXEC_POSTFLAGS MPIEXEC_MAX_NUMPROCS)
MPIEXEC_POSTFLAGS MPIEXEC_MAX_NUMPROCS)
if (MPI_INCLUDE_PATH AND MPI_LIBRARY)
# Do nothing: we already have MPI_INCLUDE_PATH and MPI_LIBRARY in
# the cache, and we don't want to override those settings.
elseif (MPI_COMPILER)
# Check whether the -showme:compile option works. This indicates
# that we have either Open MPI or a newer version of LAM-MPI, and
# implies that -showme:link will also work.
# Note that Windows distros do not have an mpi compiler to interogate.
exec_program(${MPI_COMPILER}
ARGS -showme:compile
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE
RETURN_VALUE MPI_COMPILER_RETURN)
if (MPI_COMPILER_RETURN EQUAL 0) #=============================================================================
# If we appear to have -showme:compile, then we should also have # Backward compatibility input hacks. Propagate the FindMPI hints to C and
# -showme:link. Try it. # CXX if the respective new versions are not defined. Translate the old
exec_program(${MPI_COMPILER} # MPI_LIBRARY and MPI_EXTRA_LIBRARY to respective MPI_${lang}_LIBRARIES.
ARGS -showme:link #
OUTPUT_VARIABLE MPI_LINK_CMDLINE # Once we find the new variables, we translate them back into their old
RETURN_VALUE MPI_COMPILER_RETURN) # equivalents below.
foreach (lang C CXX)
# Old input variables.
set(_MPI_OLD_INPUT_VARS COMPILER COMPILE_FLAGS INCLUDE_PATH LINK_FLAGS)
# Note that we probably have -showme:incdirs and -showme:libdirs # Set new vars based on their old equivalents, if the new versions are not already set.
# as well. foreach (var ${_MPI_OLD_INPUT_VARS})
set(MPI_COMPILER_MAY_HAVE_INCLIBDIRS TRUE) if (NOT MPI_${lang}_${var} AND MPI_${var})
endif (MPI_COMPILER_RETURN EQUAL 0) set(MPI_${lang}_${var} "${MPI_${var}}")
endif()
endforeach()
if (MPI_COMPILER_RETURN EQUAL 0) # Special handling for MPI_LIBRARY and MPI_EXTRA_LIBRARY, which we nixed in the
# Do nothing: we have our command lines now # new FindMPI. These need to be merged into MPI_<lang>_LIBRARIES
else (MPI_COMPILER_RETURN EQUAL 0) if (NOT MPI_${lang}_LIBRARIES AND (MPI_LIBRARY OR MPI_EXTRA_LIBRARY))
# Older versions of LAM-MPI have "-showme". Try it. set(MPI_${lang}_LIBRARIES ${MPI_LIBRARY} ${MPI_EXTRA_LIBRARY})
exec_program(${MPI_COMPILER}
ARGS -showme
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE
RETURN_VALUE MPI_COMPILER_RETURN)
endif (MPI_COMPILER_RETURN EQUAL 0)
if (MPI_COMPILER_RETURN EQUAL 0)
# Do nothing: we have our command lines now
else (MPI_COMPILER_RETURN EQUAL 0)
# MPICH uses "-show". Try it.
exec_program(${MPI_COMPILER}
ARGS -show
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE
RETURN_VALUE MPI_COMPILER_RETURN)
endif (MPI_COMPILER_RETURN EQUAL 0)
if (MPI_COMPILER_RETURN EQUAL 0)
# We have our command lines, but we might need to copy
# MPI_COMPILE_CMDLINE into MPI_LINK_CMDLINE, if the underlying
if (NOT MPI_LINK_CMDLINE)
SET(MPI_LINK_CMDLINE ${MPI_COMPILE_CMDLINE})
endif (NOT MPI_LINK_CMDLINE)
else (MPI_COMPILER_RETURN EQUAL 0)
message(STATUS "Unable to determine MPI from MPI driver ${MPI_COMPILER}")
endif (MPI_COMPILER_RETURN EQUAL 0)
endif (MPI_INCLUDE_PATH AND MPI_LIBRARY)
if (MPI_INCLUDE_PATH AND MPI_LIBRARY)
# Do nothing: we already have MPI_INCLUDE_PATH and MPI_LIBRARY in
# the cache, and we don't want to override those settings.
elseif (MPI_COMPILE_CMDLINE)
# Extract compile flags from the compile command line.
string(REGEX MATCHALL "(^| )-[Df]([^\" ]+|\"[^\"]+\")" MPI_ALL_COMPILE_FLAGS "${MPI_COMPILE_CMDLINE}")
set(MPI_COMPILE_FLAGS_WORK)
foreach(FLAG ${MPI_ALL_COMPILE_FLAGS})
if (MPI_COMPILE_FLAGS_WORK)
set(MPI_COMPILE_FLAGS_WORK "${MPI_COMPILE_FLAGS_WORK} ${FLAG}")
else(MPI_COMPILE_FLAGS_WORK)
set(MPI_COMPILE_FLAGS_WORK ${FLAG})
endif(MPI_COMPILE_FLAGS_WORK)
endforeach(FLAG)
# Extract include paths from compile command line
string(REGEX MATCHALL "(^| )-I([^\" ]+|\"[^\"]+\")" MPI_ALL_INCLUDE_PATHS "${MPI_COMPILE_CMDLINE}")
set(MPI_INCLUDE_PATH_WORK)
foreach(IPATH ${MPI_ALL_INCLUDE_PATHS})
string(REGEX REPLACE "^ ?-I" "" IPATH ${IPATH})
string(REGEX REPLACE "//" "/" IPATH ${IPATH})
list(APPEND MPI_INCLUDE_PATH_WORK ${IPATH})
endforeach(IPATH)
if (NOT MPI_INCLUDE_PATH_WORK)
if (MPI_COMPILER_MAY_HAVE_INCLIBDIRS)
# The compile command line didn't have any include paths on it,
# but we may have -showme:incdirs. Use it.
exec_program(${MPI_COMPILER}
ARGS -showme:incdirs
OUTPUT_VARIABLE MPI_INCLUDE_PATH_WORK
RETURN_VALUE MPI_COMPILER_RETURN)
separate_arguments(MPI_INCLUDE_PATH_WORK)
endif (MPI_COMPILER_MAY_HAVE_INCLIBDIRS)
endif (NOT MPI_INCLUDE_PATH_WORK)
if (NOT MPI_INCLUDE_PATH_WORK)
# If all else fails, just search for mpi.h in the normal include
# paths.
find_path(MPI_INCLUDE_PATH mpi.h
HINTS ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH}
PATH_SUFFIXES include
)
set(MPI_INCLUDE_PATH_WORK ${MPI_INCLUDE_PATH})
endif (NOT MPI_INCLUDE_PATH_WORK)
# Extract linker paths from the link command line
string(REGEX MATCHALL "(^| |-Wl,)-L([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_PATHS "${MPI_LINK_CMDLINE}")
set(MPI_LINK_PATH)
foreach(LPATH ${MPI_ALL_LINK_PATHS})
string(REGEX REPLACE "^(| |-Wl,)-L" "" LPATH ${LPATH})
string(REGEX REPLACE "//" "/" LPATH ${LPATH})
list(APPEND MPI_LINK_PATH ${LPATH})
endforeach(LPATH)
if (NOT MPI_LINK_PATH)
if (MPI_COMPILER_MAY_HAVE_INCLIBDIRS)
# The compile command line didn't have any linking paths on it,
# but we may have -showme:libdirs. Use it.
exec_program(${MPI_COMPILER}
ARGS -showme:libdirs
OUTPUT_VARIABLE MPI_LINK_PATH
RETURN_VALUE MPI_COMPILER_RETURN)
separate_arguments(MPI_LINK_PATH)
endif (MPI_COMPILER_MAY_HAVE_INCLIBDIRS)
endif (NOT MPI_LINK_PATH)
# Extract linker flags from the link command line
string(REGEX MATCHALL "(^| )-Wl,([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_FLAGS "${MPI_LINK_CMDLINE}")
set(MPI_LINK_FLAGS_WORK)
foreach(FLAG ${MPI_ALL_LINK_FLAGS})
if (MPI_LINK_FLAGS_WORK)
set(MPI_LINK_FLAGS_WORK "${MPI_LINK_FLAGS_WORK} ${FLAG}")
else(MPI_LINK_FLAGS_WORK)
set(MPI_LINK_FLAGS_WORK ${FLAG})
endif(MPI_LINK_FLAGS_WORK)
endforeach(FLAG)
# Extract the set of libraries to link against from the link command
# line
string(REGEX MATCHALL "(^| )-l([^\" ]+|\"[^\"]+\")" MPI_LIBNAMES "${MPI_LINK_CMDLINE}")
# Determine full path names for all of the libraries that one needs
# to link against in an MPI program
set(MPI_LIBRARIES)
foreach(LIB ${MPI_LIBNAMES})
string(REGEX REPLACE "^ ?-l" "" LIB ${LIB})
set(MPI_LIB "MPI_LIB-NOTFOUND" CACHE FILEPATH "Cleared" FORCE)
find_library(MPI_LIB ${LIB} HINTS ${MPI_LINK_PATH})
if (MPI_LIB)
list(APPEND MPI_LIBRARIES ${MPI_LIB})
elseif (NOT MPI_FIND_QUIETLY)
message(WARNING "Unable to find MPI library ${LIB}")
endif ()
endforeach(LIB)
set(MPI_LIB "MPI_LIB-NOTFOUND" CACHE INTERNAL "Scratch variable for MPI detection" FORCE)
# Chop MPI_LIBRARIES into the old-style MPI_LIBRARY and
# MPI_EXTRA_LIBRARY.
list(LENGTH MPI_LIBRARIES MPI_NUMLIBS)
list(LENGTH MPI_LIBNAMES MPI_NUMLIBS_EXPECTED)
if (MPI_NUMLIBS EQUAL MPI_NUMLIBS_EXPECTED)
list(GET MPI_LIBRARIES 0 MPI_LIBRARY_WORK)
set(MPI_LIBRARY ${MPI_LIBRARY_WORK} CACHE FILEPATH "MPI library to link against" FORCE)
else (MPI_NUMLIBS EQUAL MPI_NUMLIBS_EXPECTED)
set(MPI_LIBRARY "MPI_LIBRARY-NOTFOUND" CACHE FILEPATH "MPI library to link against" FORCE)
endif (MPI_NUMLIBS EQUAL MPI_NUMLIBS_EXPECTED)
if (MPI_NUMLIBS GREATER 1)
set(MPI_EXTRA_LIBRARY_WORK ${MPI_LIBRARIES})
list(REMOVE_AT MPI_EXTRA_LIBRARY_WORK 0)
set(MPI_EXTRA_LIBRARY ${MPI_EXTRA_LIBRARY_WORK} CACHE STRING "Extra MPI libraries to link against" FORCE)
else (MPI_NUMLIBS GREATER 1)
set(MPI_EXTRA_LIBRARY "MPI_EXTRA_LIBRARY-NOTFOUND" CACHE STRING "Extra MPI libraries to link against" FORCE)
endif (MPI_NUMLIBS GREATER 1)
# Set up all of the appropriate cache entries
set(MPI_COMPILE_FLAGS ${MPI_COMPILE_FLAGS_WORK} CACHE STRING "MPI compilation flags" FORCE)
set(MPI_INCLUDE_PATH ${MPI_INCLUDE_PATH_WORK} CACHE STRING "MPI include path" FORCE)
set(MPI_LINK_FLAGS ${MPI_LINK_FLAGS_WORK} CACHE STRING "MPI linking flags" FORCE)
else (MPI_COMPILE_CMDLINE)
# No MPI compiler to interogate so attempt to find everything with find functions.
find_path(MPI_INCLUDE_PATH mpi.h
HINTS ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH}
PATH_SUFFIXES include Inc
)
# Decide between 32-bit and 64-bit libraries for Microsoft's MPI
if("${CMAKE_SIZEOF_VOID_P}" EQUAL 8)
set(MS_MPI_ARCH_DIR amd64)
else()
set(MS_MPI_ARCH_DIR i386)
endif() endif()
endforeach()
#=============================================================================
find_library(MPI_LIBRARY
NAMES mpi mpich msmpi
HINTS ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH}
PATH_SUFFIXES lib lib/${MS_MPI_ARCH_DIR} Lib Lib/${MS_MPI_ARCH_DIR}
)
find_library(MPI_EXTRA_LIBRARY # This loop finds the compilers and sends them off for interrogation.
NAMES mpi++ foreach (lang C CXX Fortran)
HINTS ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH} if (CMAKE_${lang}_COMPILER_WORKS)
PATH_SUFFIXES lib # If the user supplies a compiler *name* instead of an absolute path, assume that we need to find THAT compiler.
DOC "Extra MPI libraries to link against.") if (MPI_${lang}_COMPILER)
is_file_executable(MPI_${lang}_COMPILER MPI_COMPILER_IS_EXECUTABLE)
if (NOT MPI_COMPILER_IS_EXECUTABLE)
# Get rid of our default list of names and just search for the name the user wants.
set(_MPI_${lang}_COMPILER_NAMES ${MPI_${lang}_COMPILER})
set(MPI_${lang}_COMPILER "MPI_${lang}_COMPILER-NOTFOUND" CACHE FILEPATH "Cleared" FORCE)
# If the user specifies a compiler, we don't want to try to search libraries either.
set(try_libs FALSE)
endif()
else()
set(try_libs TRUE)
endif()
set(MPI_COMPILE_FLAGS "" CACHE STRING "MPI compilation flags") find_program(MPI_${lang}_COMPILER
set(MPI_LINK_FLAGS "" CACHE STRING "MPI linking flags") NAMES ${_MPI_${lang}_COMPILER_NAMES}
endif (MPI_INCLUDE_PATH AND MPI_LIBRARY) PATHS "${MPI_HOME}/bin" "$ENV{MPI_HOME}/bin" ${_MPI_PREFIX_PATH})
interrogate_mpi_compiler(${lang} ${try_libs})
mark_as_advanced(MPI_${lang}_COMPILER)
# Set up extra variables to conform to # Treat each language separately as far as outputting whether we found support for it and setting MPI_<lang>_FOUND.
if (MPI_EXTRA_LIBRARY) find_package_handle_standard_args(MPI_${lang} DEFAULT_MSG MPI_${lang}_LIBRARIES MPI_${lang}_INCLUDE_PATH)
set(MPI_LIBRARIES ${MPI_LIBRARY} ${MPI_EXTRA_LIBRARY}) endif()
else (MPI_EXTRA_LIBRARY) endforeach()
set(MPI_LIBRARIES ${MPI_LIBRARY})
endif (MPI_EXTRA_LIBRARY)
if (MPI_INCLUDE_PATH AND MPI_LIBRARY)
set(MPI_FOUND TRUE) #=============================================================================
else (MPI_INCLUDE_PATH AND MPI_LIBRARY) # More backward compatibility stuff
#
# Bare MPI sans ${lang} vars are set to CXX then C, depending on what was found.
# This mimics the behavior of the old language-oblivious FindMPI.
set(_MPI_OLD_VARS FOUND COMPILER INCLUDE_PATH COMPILE_FLAGS LINK_FLAGS LIBRARIES)
if (MPI_CXX_FOUND)
foreach (var ${_MPI_OLD_VARS})
set(MPI_${var} ${MPI_CXX_${var}})
endforeach()
elseif (MPI_C_FOUND)
foreach (var ${_MPI_OLD_VARS})
set(MPI_${var} ${MPI_C_${var}})
endforeach()
else()
# Note that we might still have found Fortran, but you'll need to use MPI_Fortran_FOUND
set(MPI_FOUND FALSE) set(MPI_FOUND FALSE)
endif (MPI_INCLUDE_PATH AND MPI_LIBRARY) endif()
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake) # Chop MPI_LIBRARIES into the old-style MPI_LIBRARY and MPI_EXTRA_LIBRARY, and set them in cache.
# handle the QUIETLY and REQUIRED arguments if (MPI_LIBRARIES)
find_package_handle_standard_args(MPI DEFAULT_MSG MPI_LIBRARY MPI_INCLUDE_PATH) list(GET MPI_LIBRARIES 0 MPI_LIBRARY_WORK)
set(MPI_LIBRARY ${MPI_LIBRARY_WORK} CACHE FILEPATH "MPI library to link against" FORCE)
else()
set(MPI_LIBRARY "MPI_LIBRARY-NOTFOUND" CACHE FILEPATH "MPI library to link against" FORCE)
endif()
mark_as_advanced(MPI_INCLUDE_PATH MPI_COMPILE_FLAGS MPI_LINK_FLAGS MPI_LIBRARY list(LENGTH MPI_LIBRARIES MPI_NUMLIBS)
MPI_EXTRA_LIBRARY) if (MPI_NUMLIBS GREATER 1)
set(MPI_EXTRA_LIBRARY_WORK ${MPI_LIBRARIES})
list(REMOVE_AT MPI_EXTRA_LIBRARY_WORK 0)
set(MPI_EXTRA_LIBRARY ${MPI_EXTRA_LIBRARY_WORK} CACHE STRING "Extra MPI libraries to link against" FORCE)
else()
set(MPI_EXTRA_LIBRARY "MPI_EXTRA_LIBRARY-NOTFOUND" CACHE STRING "Extra MPI libraries to link against" FORCE)
endif()
#=============================================================================
# unset to cleanup namespace # unset these vars to cleanup namespace
unset(_MPI_PACKAGE_DIR) unset(_MPI_OLD_VARS)
unset(_MPI_PREFIX_PATH) unset(_MPI_PREFIX_PATH)
unset(_MPI_BASE_DIR) unset(_MPI_BASE_DIR)
foreach (lang C CXX Fortran)
unset(_MPI_${lang}_COMPILER_NAMES)
endforeach()