# 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.
#
# 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``
# Variable indicating the MPI settings for ``<lang>`` were found.
# ``MPI_<lang>_COMPILER``
# MPI Compiler wrapper for ``<lang>``.
# ``MPI_<lang>_COMPILE_FLAGS``
# Compilation flags for MPI programs, separated by spaces.
# This is *not* a :ref:`;-list <CMake Language Lists>`.
# ``MPI_<lang>_INCLUDE_PATH``
# Include path(s) for MPI header.
# ``MPI_<lang>_LINK_FLAGS``
# Linker flags for MPI programs.
# ``MPI_<lang>_LIBRARIES``
# All libraries to link MPI programs against.
#
# Additionally, the following :prop_tgt:`IMPORTED` targets are defined:
#
# ``MPI::MPI_<lang>``
# Target for using MPI from ``<lang>``.
#
# Additionally, FindMPI sets the following variables for running MPI
# programs from the command line:
#
# ``MPIEXEC``
# Executable for running MPI programs, if provided.
# ``MPIEXEC_NUMPROC_FLAG``
# Flag to pass to ``MPIEXEC`` before giving it the number of processors to run on.
# ``MPIEXEC_MAX_NUMPROCS``
# Number of MPI processors to utilize. Defaults to the number
# of processors detected on the host system.
# ``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, call ``find_package(MPI)``. 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 (e.g. ``mpicc``) 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} ${MPIEXEC_MAX_NUMPROCS}
# ${MPIEXEC_PREFLAGS} EXECUTABLE ${MPIEXEC_POSTFLAGS} ARGS
#
# where ``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++
m p i c x x _ r m p i C C _ r m p c x x _ r m p C C _ r m p i c + + _ r m p c + + _ r
m p i c x x . b a t )
set ( _MPI_Fortran_COMPILER_NAMES mpif95 mpif95_r mpf95 mpf95_r
m p i f 9 0 m p i f 9 0 _ r m p f 9 0 m p f 9 0 _ r
m p i f 7 7 m p i f 7 7 _ r m p f 7 7 m p f 7 7 _ 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
m p i g 7 7 m p i g 7 7 _ r m p g 7 7 m p g 7 7 _ 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
m p i x l c x x _ r m p i x l C _ r m p i x l c + + _ r m p x l c x x _ r m p x l c + + _ r m p i x l c + + _ r m p x l C C _ r )
set ( _MPI_XL_Fortran_COMPILER_NAMES mpixlf95 mpixlf95_r mpxlf95 mpxlf95_r
m p i x l f 9 0 m p i x l f 9 0 _ r m p x l f 9 0 m p x l f 9 0 _ r
m p i x l f 7 7 m p i x l f 7 7 _ r m p x l f 7 7 m p x l f 7 7 _ r
m p i x l f m p i x l f _ r m p x l f m p x l f _ 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 (
C O M M A N D " $ { c o m p i l e r } " $ { o p t i o n s }
O U T P U T _ V A R I A B L E c m d l i n e O U T P U T _ S T R I P _ T R A I L I N G _ W H I T E S P A C E
E R R O R _ V A R I A B L E c m d l i n e E R R O R _ S T R I P _ T R A I L I N G _ W H I T E S P A C E
R E S U L T _ V A R I A B L E s u c c e s s )
# 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 (
C O M M A N D $ { M P I _ $ { l a n g } _ C O M P I L E R } - s h o w m e : l i n k
O U T P U T _ V A R I A B L E M P I _ L I N K _ C M D L I N E O U T P U T _ S T R I P _ T R A I L I N G _ W H I T E S P A C E
E R R O R _ V A R I A B L E M P I _ L I N K _ C M D L I N E E R R O R _ S T R I P _ T R A I L I N G _ W H I T E S P A C E
R E S U L T _ V A R I A B L E M P I _ C O M P I L E R _ R E T U R N )
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 (
C O M M A N D $ { M P I _ $ { l a n g } _ C O M P I L E R } - s h o w m e : i n c d i r s
O U T P U T _ V A R I A B L E M P I _ I N C D I R S O U T P U T _ S T R I P _ T R A I L I N G _ W H I T E S P A C E
E R R O R _ V A R I A B L E M P I _ I N C D I R S E R R O R _ S T R I P _ T R A I L I N G _ W H I T E S P A C E )
execute_process (
C O M M A N D $ { M P I _ $ { l a n g } _ C O M P I L E R } - s h o w m e : l i b d i r s
O U T P U T _ V A R I A B L E M P I _ L I B D I R S O U T P U T _ S T R I P _ T R A I L I N G _ W H I T E S P A C E
E R R O R _ V A R I A B L E M P I _ L I B D I R S E R R O R _ S T R I P _ T R A I L I N G _ W H I T E S P A C E )
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 (
C O M M A N D $ { M P I _ $ { l a n g } _ C O M P I L E R } - l i n k - i n f o
O U T P U T _ V A R I A B L E M P I _ L I N K _ C M D L I N E O U T P U T _ S T R I P _ T R A I L I N G _ W H I T E S P A C E
E R R O R _ V A R I A B L E M P I _ L I N K _ C M D L I N E E R R O R _ S T R I P _ T R A I L I N G _ W H I T E S P A C E
R E S U L T _ V A R I A B L E M P I _ C O M P I L E R _ R E T U R N )
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
H I N T S $ { _ M P I _ B A S E _ D I R } $ { _ M P I _ P R E F I X _ P A T H }
P A T H _ S U F F I X E S i n c l u d e )
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 "(^| )([^\" ]+ ) \ \ . l i b " t m p " $ { M P I _ L I N K _ C M D L I N E } " )
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
" ; $ { C M A K E _ $ { l a n g } _ I M P L I C I T _ L I N K _ D I R E C T O R I E S } " )
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
H I N T S $ { _ M P I _ B A S E _ D I R } $ { _ M P I _ P R E F I X _ P A T H }
P A T H _ S U F F I X E S i n c l u d e I n c )
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
N A M E S m p i m p i c h m p i c h 2 m s m p i
H I N T S $ { _ M P I _ B A S E _ D I R } $ { _ M P I _ P R E F I X _ P A T H }
P A T H _ S U F F I X E S l i b l i b / $ { M S _ M P I _ A R C H _ D I R } L i b L i b / $ { M S _ M P I _ A R C H _ D I R } L i b / $ { M S _ M P I _ A R C H _ D I R 2 } )
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
N A M E S m p i + + m p i c x x c x x m p i _ c x x
H I N T S $ { _ M P I _ B A S E _ D I R } $ { _ M P I _ P R E F I X _ P A T H }
P A T H _ S U F F I X E S l i b )
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 detection 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 }
" p r o g r a m h e l l o \ n "
" i n c l u d e ' m p i f . h ' \ n "
" i n t e g e r i e r r o r \ n "
" c a l l MPI_INIT ( ierror ) \ n "
" c a l l MPI_FINALIZE ( ierror ) \ n "
" e n d \ 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"
" i n t 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
N A M E S $ { _ M P I _ E X E C _ N A M E S }
H I N T S $ { M P I _ H O M E } $ E N V { M P I _ H O M E }
P A T H S $ { _ M P I _ P R E F I X _ P A T H }
P A T H _ S U F F I X E S b i n
D O C " E x e c u t a b l e f o r r u n n i n g M P I p r o g r a m s . " )
# 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 )
# According to the MPI standard, section 8.8 -n is a guaranteed, and the only guaranteed way to
# launch an MPI process using mpiexec if such a program exists.
set ( MPIEXEC_NUMPROC_FLAG "-n" 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 the number of processes to the processor count and the previous default
# of 2 if that couldn't be determined.
include ( ${ CMAKE_CURRENT_LIST_DIR } /ProcessorCount.cmake )
ProcessorCount ( _MPIEXEC_NUMPROCS )
if ( "${_MPIEXEC_NUMPROCS}" EQUAL "0" )
set ( _MPIEXEC_NUMPROCS 2 )
endif ( )
set ( MPIEXEC_MAX_NUMPROCS "${_MPIEXEC_NUMPROCS}" CACHE STRING "Maximum number of processors available to run MPI applications." )
unset ( _MPIEXEC_NUMPROCS )
mark_as_advanced ( MPIEXEC MPIEXEC_NUMPROC_FLAG MPIEXEC_PREFLAGS MPIEXEC_POSTFLAGS MPIEXEC_MAX_NUMPROCS )
#=============================================================================
# Backward compatibility input hacks. Propagate the FindMPI hints to C and
# CXX if the respective new versions are not defined. Translate the old
# MPI_LIBRARY and MPI_EXTRA_LIBRARY to respective MPI_${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
N A M E S $ { _ M P I _ $ { l a n g } _ C O M P I L E R _ N A M E S }
H I N T S $ { _ M P I _ B A S E _ D I R } / b i n
P A T H S $ { _ M P I _ P R E F I X _ P A T H }
)
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 ( )
if ( MPI_ ${ lang } _FOUND )
if ( NOT TARGET MPI::MPI_ ${ lang } )
add_library ( MPI::MPI_ ${ lang } INTERFACE IMPORTED )
endif ( )
if ( MPI_ ${ lang } _COMPILE_FLAGS )
separate_arguments ( _MPI_ ${ lang } _COMPILE_OPTIONS NATIVE_COMMAND "${MPI_${lang}_COMPILE_FLAGS}" )
set_property ( TARGET MPI::MPI_ ${ lang } PROPERTY
I N T E R F A C E _ C O M P I L E _ O P T I O N S " $ { _ M P I _ $ { l a n g } _ C O M P I L E _ O P T I O N S } " )
endif ( )
unset ( _MPI_ ${ lang } _LINK_LINE )
if ( MPI_ ${ lang } _LINK_FLAGS )
list ( APPEND _MPI_ ${ lang } _LINK_LINE "${MPI_${lang}_LINK_FLAGS}" )
endif ( )
list ( APPEND _MPI_ ${ lang } _LINK_LINE "${MPI_${lang}_LIBRARIES}" )
set_property ( TARGET MPI::MPI_ ${ lang } PROPERTY
I N T E R F A C E _ L I N K _ L I B R A R I E S " $ { _ M P I _ $ { l a n g } _ L I N K _ L I N E } " )
set_property ( TARGET MPI::MPI_ ${ lang } PROPERTY
I N T E R F A C E _ I N C L U D E _ D I R E C T O R I E S " $ { M P I _ $ { l a n g } _ I N C L U D E _ P A T H } " )
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 ( )
mark_as_advanced ( MPI_LIBRARY MPI_EXTRA_LIBRARY )
#=============================================================================
# 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 ( )
