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# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#.rst:
# FindMPI
# -------
#
# Find a Message Passing Interface (MPI) implementation
#
# The Message Passing Interface (MPI) is a library used to write
# high-performance distributed-memory parallel applications, and is
# typically deployed on a cluster. MPI is a standard interface (defined
# by the MPI forum) for which many implementations are available. All
# of them have somewhat different include paths, libraries to link
# against, etc., and this module tries to smooth out those differences.
#
# Variables
# ^^^^^^^^^
#
# This module will set the following variables per language in your
# project, where <lang> is one of C, CXX, or Fortran:
#
# ::
#
# 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
#
# Additionally, FindMPI sets the following variables for running MPI
# programs from the command line:
#
# ::
#
# MPIEXEC Executable for running MPI programs
# MPIEXEC_NUMPROC_FLAG Flag to pass to MPIEXEC before giving
# it the number of processors to run on
# MPIEXEC_PREFLAGS Flags to pass to MPIEXEC directly
# before the executable to run.
# MPIEXEC_POSTFLAGS Flags to pass to MPIEXEC after other flags
#
# Usage
# ^^^^^
#
# To use this module, simply call FindMPI from a CMakeLists.txt file, or
# run ``find_package(MPI)``, then run CMake. If you are happy with the
# auto-detected configuration for your language, then you're done. If
# not, you have two options:
#
# ::
#
# 1. Set MPI_<lang>_COMPILER to the MPI wrapper (mpicc, etc.) of your
# choice and reconfigure. FindMPI will attempt to determine all the
# necessary variables using THAT compiler's compile and link flags.
# 2. If this fails, or if your MPI implementation does not come with
# 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.
#
# 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 ${MPIEXEC_POSTFLAGS} ARGS
#
# where ``PROCS`` is the number of processors on which to execute the
# program, ``EXECUTABLE`` is the MPI program, and ``ARGS`` are the arguments to
# pass to the MPI program.
#
# Backward Compatibility
# ^^^^^^^^^^^^^^^^^^^^^^
#
# For backward compatibility with older versions of FindMPI, these
# variables are set, but deprecated:
#
# ::
#
# MPI_FOUND MPI_COMPILER MPI_LIBRARY
# MPI_COMPILE_FLAGS MPI_INCLUDE_PATH MPI_EXTRA_LIBRARY
# MPI_LINK_FLAGS MPI_LIBRARIES
#
# In new projects, please use the ``MPI_<lang>_XXX`` equivalents.
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
#
# This part detects MPI compilers, attempting to wade through the mess of compiler names in
# a sensible way.
#
# The compilers are detected in this order:
#
# 1. Try to find the most generic available 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.
#
# Start out with the generic MPI compiler names, as these are most commonly used.
set(_MPI_C_COMPILER_NAMES mpicc mpcc mpicc_r mpcc_r mpicc.bat)
set(_MPI_CXX_COMPILER_NAMES mpicxx mpiCC mpcxx mpCC mpic++ mpc++
mpicxx_r mpiCC_r mpcxx_r mpCC_r mpic++_r mpc++_r
mpicxx.bat)
set(_MPI_Fortran_COMPILER_NAMES mpif95 mpif95_r mpf95 mpf95_r
mpif90 mpif90_r mpf90 mpf90_r
mpif77 mpif77_r mpf77 mpf77_r)
# 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 mpiicc.bat)
set(_MPI_Intel_CXX_COMPILER_NAMES mpiicpc mpiicxx mpiic++ mpiiCC mpiicpc.bat)
set(_MPI_Intel_Fortran_COMPILER_NAMES mpiifort mpiif95 mpiif90 mpiif77 mpiifort.bat)
# 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}_${lang}_COMPILER_NAMES) # clean up the namespace here
endforeach()
endforeach()
# Names to try for MPI exec
set(_MPI_EXEC_NAMES mpiexec mpirun lamexec srun)
# Grab the path to MPI from the registry if we're on windows.
set(_MPI_PREFIX_PATH)
if(WIN32)
# MSMPI
file(TO_CMAKE_PATH "$ENV{MSMPI_BIN}" msmpi_bin_path) # The default path ends with a '\' and doesn't mix with ';' when appending.
list(APPEND _MPI_PREFIX_PATH "${msmpi_bin_path}")
unset(msmpi_bin_path)
list(APPEND _MPI_PREFIX_PATH "[HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\MPI;InstallRoot]/Bin")
list(APPEND _MPI_PREFIX_PATH "$ENV{MSMPI_INC}/..") # The SDK is installed separately from the runtime
# MPICH
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 "$ENV{ProgramW6432}/MPICH2/")
endif()
# Build a list of prefixes to search for MPI.
foreach(SystemPrefixDir ${CMAKE_SYSTEM_PREFIX_PATH})
foreach(MpiPackageDir ${_MPI_PREFIX_PATH})
if(EXISTS ${SystemPrefixDir}/${MpiPackageDir})
list(APPEND _MPI_PREFIX_PATH "${SystemPrefixDir}/${MpiPackageDir}")
endif()
endforeach()
endforeach()
function (_mpi_check_compiler compiler options cmdvar resvar)
execute_process(
COMMAND "${compiler}" ${options}
OUTPUT_VARIABLE cmdline OUTPUT_STRIP_TRAILING_WHITESPACE
ERROR_VARIABLE cmdline ERROR_STRIP_TRAILING_WHITESPACE
RESULT_VARIABLE success)
# Intel MPI 5.0.1 will return a zero return code even when the
# argument to the MPI compiler wrapper is unknown. Attempt to
# catch this case.
if(cmdline MATCHES "undefined reference" OR cmdline MATCHES "unrecognized")
set(success 255 )
endif()
set(${cmdvar} "${cmdline}" PARENT_SCOPE)
set(${resvar} "${success}" PARENT_SCOPE)
endfunction()
#
# interrogate_mpi_compiler(lang try_libs)
#
# Attempts to extract compiler and linker args from an MPI compiler. The arguments set
# by this function are:
#
# MPI_<lang>_INCLUDE_PATH MPI_<lang>_LINK_FLAGS MPI_<lang>_FOUND
# MPI_<lang>_COMPILE_FLAGS MPI_<lang>_LIBRARIES
#
# MPI_<lang>_COMPILER must be set beforehand to the absolute path to an MPI compiler for
# <lang>. Additionally, MPI_<lang>_INCLUDE_PATH and MPI_<lang>_LIBRARIES may be set
# to skip autodetection.
#
# If try_libs is TRUE, this will also attempt to find plain MPI libraries in the usual
# way. In general, this is not as effective as interrogating the compilers, as it
# ignores language-specific flags and libraries. However, some MPI implementations
# (Windows implementations) do not have compiler wrappers, so this approach must be used.
#
function (interrogate_mpi_compiler lang try_libs)
# MPI_${lang}_NO_INTERROGATE will be set to a compiler name when the *regular* compiler was
# discovered to be the MPI compiler. This happens on machines like the Cray XE6 that use
# modules to set cc, CC, and ftn to the MPI compilers. If the user force-sets another MPI
# compiler, MPI_${lang}_COMPILER won't be equal to MPI_${lang}_NO_INTERROGATE, and we'll
# inspect that compiler anew. This allows users to set new compilers w/o rm'ing cache.
string(COMPARE NOTEQUAL "${MPI_${lang}_NO_INTERROGATE}" "${MPI_${lang}_COMPILER}" interrogate)
# If MPI is set already in the cache, don't bother with interrogating the compiler.
if (interrogate AND ((NOT MPI_${lang}_INCLUDE_PATH) OR (NOT MPI_${lang}_LIBRARIES)))
if (MPI_${lang}_COMPILER)
# Check whether the -showme:compile option works. This indicates that we have either OpenMPI
# or a newer version of LAM-MPI, and implies that -showme:link will also work.
_mpi_check_compiler("${MPI_${lang}_COMPILER}" "-showme:compile" MPI_COMPILE_CMDLINE 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)
_mpi_check_compiler("${MPI_${lang}_COMPILER}" "-showme" MPI_COMPILE_CMDLINE MPI_COMPILER_RETURN)
endif()
# MVAPICH uses -compile-info and -link-info. Try them.
if (NOT MPI_COMPILER_RETURN EQUAL 0)
_mpi_check_compiler("${MPI_${lang}_COMPILER}" "-compile-info" MPI_COMPILE_CMDLINE 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)
_mpi_check_compiler("${MPI_${lang}_COMPILER}" "-show" MPI_COMPILE_CMDLINE 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})
string(REGEX REPLACE "^ " "" FLAG ${FLAG})
if (MPI_COMPILE_FLAGS_WORK)
string(APPEND 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}")
set(MPI_INCLUDE_PATH_WORK)
foreach(IPATH ${MPI_ALL_INCLUDE_PATHS})
string(REGEX REPLACE "^ ?-I" "" IPATH ${IPATH})
string(REPLACE "//" "/" IPATH ${IPATH})
string(REPLACE "\"" "" IPATH ${IPATH})
file(TO_CMAKE_PATH "${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 ${MPI_HEADER_PATH})
endif()
# Extract linker paths from the link command line
string(REGEX MATCHALL "(^| |-Wl,)(-L|/LIBPATH:)([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_PATHS "${MPI_LINK_CMDLINE}")
set(MPI_LINK_PATH)
foreach(LPATH ${MPI_ALL_LINK_PATHS})
string(REGEX REPLACE "^(| |-Wl,)(-L|/LIBPATH:)" "" LPATH ${LPATH})
string(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 ${MPI_LIBDIRS})
separate_arguments(MPI_LINK_PATH)
endif()
# Extract linker flags from the link command line
string(REGEX MATCHALL "(^| )(-Wl,|-Xlinker )([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_FLAGS "${MPI_LINK_CMDLINE}")
set(MPI_LINK_FLAGS_WORK)
foreach(FLAG ${MPI_ALL_LINK_FLAGS})
string(REGEX REPLACE "^ " "" FLAG ${FLAG})
if (MPI_LINK_FLAGS_WORK)
string(APPEND 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}")
if(WIN32)
# The intel wrappers on windows link against static versions of the MPI libraries.
# The static libraries are simply listed on the command line without -l.
# For instance: " icl ... impi.lib "
string(REGEX MATCHALL "(^| )([^\" ]+)\\.lib" tmp "${MPI_LINK_CMDLINE}")
list(APPEND MPI_LIBNAMES ${tmp})
endif()
# add the compiler implicit directories because some compilers
# such as the intel compiler have libraries that show up
# in the showme list that can only be found in the implicit
# link directories of the compiler.
if (DEFINED CMAKE_${lang}_IMPLICIT_LINK_DIRECTORIES)
string(APPEND MPI_LINK_PATH
";${CMAKE_${lang}_IMPLICIT_LINK_DIRECTORIES}")
endif ()
# 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 ${LIB})
if(WIN32)
string(REGEX REPLACE "\\.lib$" "" LIB ${LIB})
endif()
string(STRIP ${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 x64)
set(MS_MPI_ARCH_DIR2 amd64)
else()
set(MS_MPI_ARCH_DIR x86)
set(MS_MPI_ARCH_DIR2 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/${MS_MPI_ARCH_DIR} Lib/${MS_MPI_ARCH_DIR2})
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)
list(APPEND 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()
# This function attempts to compile with the regular compiler, to see if MPI programs
# work with it. This is a last ditch attempt after we've tried interrogating mpicc and
# friends, and after we've tried to find generic libraries. Works on machines like
# Cray XE6, where the modules environment changes what MPI version cc, CC, and ftn use.
function(try_regular_compiler lang success)
set(scratch_directory ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY})
if (${lang} STREQUAL Fortran)
set(test_file ${scratch_directory}/cmake_mpi_test.f90)
file(WRITE ${test_file}
"program hello\n"
"include 'mpif.h'\n"
"integer ierror\n"
"call MPI_INIT(ierror)\n"
"call MPI_FINALIZE(ierror)\n"
"end\n")
else()
if (${lang} STREQUAL CXX)
set(test_file ${scratch_directory}/cmake_mpi_test.cpp)
else()
set(test_file ${scratch_directory}/cmake_mpi_test.c)
endif()
file(WRITE ${test_file}
"#include <mpi.h>\n"
"int main(int argc, char **argv) {\n"
" MPI_Init(&argc, &argv);\n"
" MPI_Finalize();\n"
"}\n")
endif()
try_compile(compiler_has_mpi ${scratch_directory} ${test_file})
if (compiler_has_mpi)
set(MPI_${lang}_NO_INTERROGATE ${CMAKE_${lang}_COMPILER} CACHE STRING "Whether to interrogate MPI ${lang} compiler" FORCE)
set(MPI_${lang}_COMPILER ${CMAKE_${lang}_COMPILER} CACHE STRING "MPI ${lang} compiler" FORCE)
set(MPI_${lang}_COMPILE_FLAGS "" CACHE STRING "MPI ${lang} compilation flags" FORCE)
set(MPI_${lang}_INCLUDE_PATH "" CACHE STRING "MPI ${lang} include path" FORCE)
set(MPI_${lang}_LINK_FLAGS "" CACHE STRING "MPI ${lang} linking flags" FORCE)
set(MPI_${lang}_LIBRARIES "" CACHE STRING "MPI ${lang} libraries to link against" FORCE)
endif()
set(${success} ${compiler_has_mpi} PARENT_SCOPE)
unset(compiler_has_mpi CACHE)
endfunction()
# End definitions, commence real work here.
# Most mpi distros have some form of mpiexec which gives us something we can reliably look for.
find_program(MPIEXEC
NAMES ${_MPI_EXEC_NAMES}
HINTS ${MPI_HOME} $ENV{MPI_HOME}
PATHS ${_MPI_PREFIX_PATH}
PATH_SUFFIXES bin
DOC "Executable for running MPI programs.")
# call get_filename_component twice to remove mpiexec and the directory it exists in (typically bin).
# This gives us a fairly reliable base directory to search for /bin /lib and /include from.
get_filename_component(_MPI_BASE_DIR "${MPIEXEC}" PATH)
get_filename_component(_MPI_BASE_DIR "${_MPI_BASE_DIR}" PATH)
set(MPIEXEC_NUMPROC_FLAG "-np" CACHE STRING "Flag used by MPI to specify the number of processes for MPIEXEC; the next option will be the number of processes.")
set(MPIEXEC_PREFLAGS "" CACHE STRING "These flags will be directly before the executable that is being run by MPIEXEC.")
set(MPIEXEC_POSTFLAGS "" CACHE STRING "These flags will come after all flags given to MPIEXEC.")
set(MPIEXEC_MAX_NUMPROCS "2" CACHE STRING "Maximum number of processors available to run MPI applications.")
mark_as_advanced(MPIEXEC MPIEXEC_NUMPROC_FLAG MPIEXEC_PREFLAGS MPIEXEC_POSTFLAGS MPIEXEC_MAX_NUMPROCS)
#=============================================================================
# Backward compatibility input hacks. Propagate the FindMPI hints to C and
# CXX if the respective new versions are not defined. Translate the old
# MPI_LIBRARY and MPI_EXTRA_LIBRARY to respective MPI_${lang}_LIBRARIES.
#
# Once we find the new variables, we translate them back into their old
# equivalents below.
foreach (lang C CXX)
# Old input variables.
set(_MPI_OLD_INPUT_VARS COMPILER COMPILE_FLAGS INCLUDE_PATH LINK_FLAGS)
# Set new vars based on their old equivalents, if the new versions are not already set.
foreach (var ${_MPI_OLD_INPUT_VARS})
if (NOT MPI_${lang}_${var} AND MPI_${var})
set(MPI_${lang}_${var} "${MPI_${var}}")
endif()
endforeach()
# Special handling for MPI_LIBRARY and MPI_EXTRA_LIBRARY, which we nixed in the
# new FindMPI. These need to be merged into MPI_<lang>_LIBRARIES
if (NOT MPI_${lang}_LIBRARIES AND (MPI_LIBRARY OR MPI_EXTRA_LIBRARY))
set(MPI_${lang}_LIBRARIES ${MPI_LIBRARY} ${MPI_EXTRA_LIBRARY})
endif()
endforeach()
#=============================================================================
# This loop finds the compilers and sends them off for interrogation.
foreach (lang C CXX Fortran)
if (CMAKE_${lang}_COMPILER_WORKS)
# If the user supplies a compiler *name* instead of an absolute path, assume that we need to find THAT compiler.
if (MPI_${lang}_COMPILER)
if (NOT IS_ABSOLUTE "${MPI_${lang}_COMPILER}")
# Get rid of our default list of names and just search for the name the user wants.
set(_MPI_${lang}_COMPILER_NAMES ${MPI_${lang}_COMPILER})
set(MPI_${lang}_COMPILER "MPI_${lang}_COMPILER-NOTFOUND" CACHE FILEPATH "Cleared" FORCE)
endif()
# If the user specifies a compiler, we don't want to try to search libraries either.
set(try_libs FALSE)
else()
set(try_libs TRUE)
endif()
find_program(MPI_${lang}_COMPILER
NAMES ${_MPI_${lang}_COMPILER_NAMES}
HINTS ${_MPI_BASE_DIR}/bin
PATHS ${_MPI_PREFIX_PATH}
)
interrogate_mpi_compiler(${lang} ${try_libs})
mark_as_advanced(MPI_${lang}_COMPILER)
# last ditch try -- if nothing works so far, just try running the regular compiler and
# see if we can create an MPI executable.
set(regular_compiler_worked 0)
if (NOT MPI_${lang}_LIBRARIES OR NOT MPI_${lang}_INCLUDE_PATH)
try_regular_compiler(${lang} regular_compiler_worked)
endif()
set(MPI_${lang}_FIND_QUIETLY ${MPI_FIND_QUIETLY})
set(MPI_${lang}_FIND_REQUIRED ${MPI_FIND_REQUIRED})
set(MPI_${lang}_FIND_VERSION ${MPI_FIND_VERSION})
set(MPI_${lang}_FIND_VERSION_EXACT ${MPI_FIND_VERSION_EXACT})
if (regular_compiler_worked)
find_package_handle_standard_args(MPI_${lang} DEFAULT_MSG MPI_${lang}_COMPILER)
else()
find_package_handle_standard_args(MPI_${lang} DEFAULT_MSG MPI_${lang}_LIBRARIES MPI_${lang}_INCLUDE_PATH)
endif()
endif()
endforeach()
#=============================================================================
# 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)
endif()
# Chop MPI_LIBRARIES into the old-style MPI_LIBRARY and MPI_EXTRA_LIBRARY, and set them in cache.
if (MPI_LIBRARIES)
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()
list(LENGTH MPI_LIBRARIES MPI_NUMLIBS)
if (MPI_NUMLIBS GREATER 1)
set(MPI_EXTRA_LIBRARY_WORK ${MPI_LIBRARIES})
list(REMOVE_AT MPI_EXTRA_LIBRARY_WORK 0)
set(MPI_EXTRA_LIBRARY ${MPI_EXTRA_LIBRARY_WORK} CACHE STRING "Extra MPI libraries to link against" FORCE)
else()
set(MPI_EXTRA_LIBRARY "MPI_EXTRA_LIBRARY-NOTFOUND" CACHE STRING "Extra MPI libraries to link against" FORCE)
endif()
#=============================================================================
# unset these vars to cleanup namespace
unset(_MPI_OLD_VARS)
unset(_MPI_PREFIX_PATH)
unset(_MPI_BASE_DIR)
foreach (lang C CXX Fortran)
unset(_MPI_${lang}_COMPILER_NAMES)
endforeach()