From 5b3e62c7bc11eab36548f9c61717a05a02655979 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <doug.gregor@gmail.com>
Date: Mon, 31 Mar 2008 10:55:32 -0400
Subject: ENH: Enhance FindMPI module by properly handling backward
compatibility with the older module, adding documentation, and coping with
multiple include and linker paths
---
Modules/FindMPI.cmake | 228 +++++++++++++++++++++++++++++---------------------
1 file changed, 132 insertions(+), 96 deletions(-)
diff --git a/Modules/FindMPI.cmake b/Modules/FindMPI.cmake
index 627effc..5e218e7 100644
--- a/Modules/FindMPI.cmake
+++ b/Modules/FindMPI.cmake
@@ -1,95 +1,132 @@
-# This module looks for the Message Passing Interface (MPI).
+# - Message Passing Interface (MPI) module.
+#
+# The Message Passing Interface (MPI) is a library used to write
+# high-performance parallel applications that use message passing, 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 these implementations have somewhat different
+# compilation approaches (different include paths, libraries to link
+# against, etc.), and this module tries to smooth out those differences.
#
# This module will set the following variables:
# MPI_FOUND TRUE if we have found MPI
# MPI_COMPILE_FLAGS Compilation flags for MPI programs
-# MPI_INCLUDE_PATH Include path for MPI header
+# MPI_INCLUDE_PATH Include path(s) for MPI header
# MPI_LINK_FLAGS Linking flags for MPI programs
-# MPI_LIBRARIES Libraries to link MPI programs against
-# MPI_LIBRARY Deprecated; first MPI library to link against
-# MPI_EXTRA_LIBRARY Deprecated; second MPI library to link against
+# MPI_LIBRARY First MPI library to link against (cached)
+# MPI_EXTRA_LIBRARY Extra MPI libraries to link against (cached)
+# MPI_LIBRARIES All libraries to link MPI programs against
# 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 all other flags.
#
# This module will attempt to auto-detect these settings, first by
-# looking for a C++ MPI driver (e.g., mpic++, mpiCC, or mpicxx; set by
-# MPICXX) and later by checking common MPI paths and library names.
+# looking for a MPI compiler, which many MPI implementations provide
+# as a pass-through to the native compiler to simplify the compilation
+# of MPI programs. The MPI compiler is stored in the cache variable
+# MPI_COMPILER, and will attempt to look for commonly-named drivers
+# mpic++, mpicxx, mpiCC, or mpicc. If the compiler driver is found and
+# recognized, it will be used to set all of the module variables. To
+# skip this auto-detection, set MPI_LIBRARY and MPI_INCLUDE_PATH in
+# the CMake cache.
+#
+# If no compiler driver is found or the compiler driver is not
+# recognized, this module will then search for common include paths
+# and library names to try to detect MPI.
+#
+# 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,
+# EXECUTABLE is the MPI program, and ARGS are the arguments to pass to the
+# MPI program.
# Try to find the MPI driver program
-find_program(MPICXX
- NAMES mpic++ mpicxx mpiCC
- DOC "MPI C++ compiler. Used only to detect MPI compilation flags.")
-mark_as_advanced(MPICXX)
+find_program(MPI_COMPILER
+ NAMES mpic++ mpicxx mpiCC mpicc
+ DOC "MPI compiler. Used only to detect MPI compilation flags.")
+mark_as_advanced(MPI_COMPILER)
find_program(MPIEXEC
- NAMES mpiexec mpirun
+ NAMES mpiexec mpirun lamexec
DOC "Executable for running MPI programs.")
-mark_as_advanced(MPIEXEC)
-if (NOT OLD_MPICXX STREQUAL MPICXX)
- set(MPI_FORCE_RECONFIGURE TRUE)
- set(OLD_MPICXX ${MPICXX} CACHE INTERNAL "Previous value of MPICXX" FORCE)
-endif (NOT OLD_MPICXX STREQUAL MPICXX)
-
-if (NOT MPICXX)
- # If there is no MPI C++ compiler, we force ourselves to configure
- # MPI the old way.
- set(MPI_FORCE_RECONFIGURE TRUE)
-endif (NOT MPICXX)
+set(MPIEXEC_NUMPROC_FLAG "-np" CACHE STRING "Flag used by MPI to specify the number of processes for MPIEXEC; the next option will be the number of processes.")
+set(MPIEXEC_PREFLAGS "" CACHE STRING "These flags will be directly before the executable that is being run by MPIEXEC.")
+set(MPIEXEC_POSTFLAGS "" CACHE STRING "These flags will come after all flags given to MPIEXEC.")
+set(MPIEXEC_MAX_NUMPROCS "2" CACHE STRING "Maximum number of processors available to run MPI applications.")
+mark_as_advanced(MPIEXEC MPIEXEC_NUMPROC_FLAG MPIEXEC_PREFLAGS
+ MPIEXEC_POSTFLAGS MPIEXEC_MAX_NUMPROCS)
-if (MPICXX)
+if (MPI_INCLUDE_PATH AND MPI_LIBRARY)
+ # Do nothing: we already have MPI_INCLUDE_PATH and MPI_LIBRARY in
+ # the cache, and we don't want to override those settings.
+elseif (MPI_COMPILER)
# Check whether the -showme:compile option works. This indicates
# that we have either Open MPI or a newer version of LAM-MPI, and
# implies that -showme:link will also work.
- exec_program(${MPICXX}
+ exec_program(${MPI_COMPILER}
ARGS -showme:compile
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE
- RETURN_VALUE MPICXX_RETURN)
+ RETURN_VALUE MPI_COMPILER_RETURN)
- if (MPICXX_RETURN EQUAL 0)
+ if (MPI_COMPILER_RETURN EQUAL 0)
# If we appear to have -showme:compile, then we should also have
# -showme:link. Try it.
- exec_program(${MPICXX}
+ exec_program(${MPI_COMPILER}
ARGS -showme:link
OUTPUT_VARIABLE MPI_LINK_CMDLINE
- RETURN_VALUE MPICXX_RETURN)
- endif (MPICXX_RETURN EQUAL 0)
+ RETURN_VALUE MPI_COMPILER_RETURN)
+ endif (MPI_COMPILER_RETURN EQUAL 0)
- if (MPICXX_RETURN EQUAL 0)
+ if (MPI_COMPILER_RETURN EQUAL 0)
# Do nothing: we have our command lines now
- else (MPICXX_RETURN EQUAL 0)
+ else (MPI_COMPILER_RETURN EQUAL 0)
# Older versions of LAM-MPI have "-showme". Try it.
- exec_program(${MPICXX}
+ exec_program(${MPI_COMPILER}
ARGS -showme
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE
- RETURN_VALUE MPICXX_RETURN)
- endif (MPICXX_RETURN EQUAL 0)
+ RETURN_VALUE MPI_COMPILER_RETURN)
+ endif (MPI_COMPILER_RETURN EQUAL 0)
- if (MPICXX_RETURN EQUAL 0)
+ if (MPI_COMPILER_RETURN EQUAL 0)
# Do nothing: we have our command lines now
- else (MPICXX_RETURN EQUAL 0)
+ else (MPI_COMPILER_RETURN EQUAL 0)
# MPICH uses "-show". Try it.
- exec_program(${MPICXX}
+ exec_program(${MPI_COMPILER}
ARGS -show
OUTPUT_VARIABLE MPI_COMPILE_CMDLINE
- RETURN_VALUE MPICXX_RETURN)
- endif (MPICXX_RETURN EQUAL 0)
+ RETURN_VALUE MPI_COMPILER_RETURN)
+ endif (MPI_COMPILER_RETURN EQUAL 0)
- if (MPICXX_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 (MPICXX_RETURN EQUAL 0)
- message(STATUS "Unable to determine MPI from MPI driver ${MPICXX}")
- endif (MPICXX_RETURN EQUAL 0)
-endif (MPICXX)
+ 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 (NOT MPI_FORCE_RECONFIGURE)
- # We don't actually have to reconfigure anything
+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 "-D([^\" ]+|\"[^\"]+\")" MPI_ALL_COMPILE_FLAGS ${MPI_COMPILE_CMDLINE})
+ string(REGEX MATCHALL "-D([^\" ]+|\"[^\"]+\")" MPI_ALL_COMPILE_FLAGS "${MPI_COMPILE_CMDLINE}")
set(MPI_COMPILE_FLAGS_WORK)
foreach(FLAG ${MPI_ALL_COMPILE_FLAGS})
if (MPI_COMPILE_FLAGS_WORK)
@@ -100,17 +137,25 @@ elseif (MPI_COMPILE_CMDLINE)
endforeach(FLAG)
# Extract include paths from compile command line
- string(REGEX MATCH "-I([^\" ]+|\"[^\"]+\")" MPI_INCLUDE_PATH ${MPI_COMPILE_CMDLINE})
- string(REGEX REPLACE "^-I" "" MPI_INCLUDE_PATH ${MPI_INCLUDE_PATH})
- string(REGEX REPLACE "//" "/" MPI_INCLUDE_PATH ${MPI_INCLUDE_PATH})
-
+ string(REGEX MATCHALL "-I([^\" ]+|\"[^\"]+\")" MPI_ALL_INCLUDE_PATHS "${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)
+
# Extract linker paths from the link command line
- string(REGEX MATCH "-L([^\" ]+|\"[^\"]+\")" MPI_LINK_PATH ${MPI_LINK_CMDLINE})
- string(REGEX REPLACE "^-L" "" MPI_LINK_PATH ${MPI_LINK_PATH})
- string(REGEX REPLACE "//" "/" MPI_LINK_PATH ${MPI_LINK_PATH})
+ string(REGEX MATCHALL "-L([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_PATHS "${MPI_LINK_CMDLINE}")
+ set(MPI_LINK_PATH)
+ foreach(LPATH ${MPI_ALL_LINK_PATHS})
+ string(REGEX REPLACE "^-L" "" LPATH ${LPATH})
+ string(REGEX REPLACE "//" "/" LPATH ${LPATH})
+ list(APPEND MPI_LINK_PATH ${LPATH})
+ endforeach(LPATH)
# Extract linker flags from the link command line
- string(REGEX MATCHALL "-Wl,([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_FLAGS ${MPI_LINK_CMDLINE})
+ string(REGEX MATCHALL "-Wl,([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_FLAGS "${MPI_LINK_CMDLINE}")
set(MPI_LINK_FLAGS_WORK)
foreach(FLAG ${MPI_ALL_LINK_FLAGS})
if (MPI_LINK_FLAGS_WORK)
@@ -122,7 +167,7 @@ elseif (MPI_COMPILE_CMDLINE)
# Extract the set of libraries to link against from the link command
# line
- string(REGEX MATCHALL "-l([^\" ]+|\"[^\"]+\")" MPI_LIBNAMES ${MPI_LINK_CMDLINE})
+ string(REGEX MATCHALL "-l([^\" ]+|\"[^\"]+\")" MPI_LIBNAMES "${MPI_LINK_CMDLINE}")
# Determine full path names for all of the libraries that one needs
# to link against in an MPI program
@@ -143,31 +188,23 @@ elseif (MPI_COMPILE_CMDLINE)
# MPI_EXTRA_LIBRARY.
list(LENGTH MPI_LIBRARIES MPI_NUMLIBS)
if (MPI_NUMLIBS GREATER 0)
- list(GET MPI_LIBRARIES 0 MPI_LIBRARY)
+ 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 GREATER 0)
- set(MPI_LIBRARY "MPI_LIBRARY-NOTFOUND")
+ set(MPI_LIBRARY "MPI_LIBRARY-NOTFOUND" CACHE STRING "MPI library to link against" FORCE)
endif (MPI_NUMLIBS GREATER 0)
if (MPI_NUMLIBS GREATER 1)
- set(MPI_EXTRA_LIBRARY ${MPI_LIBRARIES})
- list(REMOVE_AT MPI_EXTRA_LIBRARY 0)
+ 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")
+ 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_FOUND TRUE CACHE INTERNAL "Whether MPI was found" FORCE)
-
- if (NOT MPI_FORCE_RECONFIGURE)
- set(MPI_COMPILE_FLAGS ${MPI_COMPILE_FLAGS_WORK} CACHE STRING "MPI compilation flags")
- set(MPI_INCLUDE_PATH ${MPI_INCLUDE_PATH} CACHE STRING "MPI include path")
- set(MPI_LINK_FLAGS ${MPI_LINK_FLAGS_WORK} CACHE STRING "MPI linking flags")
- set(MPI_LIBRARIES ${MPI_LIBRARIES} CACHE STRING "MPI libraries to link against, separated by semicolons")
- else (NOT MPI_FORCE_RECONFIGURE)
- set(MPI_COMPILE_FLAGS ${MPI_COMPILE_FLAGS_WORK} CACHE STRING "MPI compilation flags" FORCE)
- set(MPI_INCLUDE_PATH ${MPI_INCLUDE_PATH} CACHE STRING "MPI include path" FORCE)
- set(MPI_LINK_FLAGS ${MPI_LINK_FLAGS_WORK} CACHE STRING "MPI linking flags" FORCE)
- set(MPI_LIBRARIES ${MPI_LIBRARIES} CACHE STRING "MPI libraries to link against, separated by semicolons" FORCE)
- endif (NOT MPI_FORCE_RECONFIGURE)
+ 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 ${MPI_LINK_FLAGS_WORK} CACHE STRING "MPI linking flags" FORCE)
else (MPI_COMPILE_CMDLINE)
find_path(MPI_INCLUDE_PATH mpi.h
/usr/local/include
@@ -176,16 +213,16 @@ else (MPI_COMPILE_CMDLINE)
/usr/local/mpi/include
"C:/Program Files/MPICH/SDK/Include"
"$ENV{SystemDrive}/Program Files/MPICH2/include"
- "C:/Program Files/Microsoft Compute Cluster Pack/Include"
+ "$ENV{SystemDrive}/Program Files/Microsoft Compute Cluster Pack/Include"
)
- # TODO: How do we know whether we're building 32-bit vs. 64-bit?
+ # TODO: How do we know whether we're building 32-bit vs. 64-bit for MS-MPI?
find_library(MPI_LIBRARY
NAMES mpi mpich
PATHS /usr/lib /usr/local/lib /usr/local/mpi/lib
"C:/Program Files/MPICH/SDK/Lib"
"$ENV{SystemDrive}/Program Files/MPICH/SDK/Lib"
- "C:/Program Files/Microsoft Compute Cluster Pack/Lib/i386"
+ "$ENV{SystemDrive}/Program Files/Microsoft Compute Cluster Pack/Lib/i386"
)
find_library(MPI_LIBRARY
NAMES mpich2
@@ -196,24 +233,11 @@ else (MPI_COMPILE_CMDLINE)
NAMES mpi++
PATHS /usr/lib /usr/local/lib /usr/local/mpi/lib
"C:/Program Files/MPICH/SDK/Lib"
- "C:/Program Files/Microsoft Compute Cluster Pack/Lib/i386"
- DOC "If a second MPI library is necessary, specify it here.")
+ DOC "Extra MPI libraries to link against.")
set(MPI_COMPILE_FLAGS "" CACHE STRING "MPI compilation flags")
set(MPI_LINK_FLAGS "" CACHE STRING "MPI linking flags")
-
- if (MPI_EXTRA_LIBRARY)
- set(MPI_LIBRARIES "${MPI_LIBRARY};${MPI_EXTRA_LIBRARY}" CACHE STRING "MPI libraries to link against, separated by semicolons")
- else (MPI_EXTRA_LIBRARY)
- set(MPI_LIBRARIES ${MPI_LIBRARY} CACHE STRING "MPI libraries to link against, separated by semicolons")
- endif (MPI_EXTRA_LIBRARY)
-
- if (MPI_LIBRARY)
- set(MPI_FOUND TRUE CACHE INTERNAL "Whether MPI was found" FORCE)
- else (MPI_LIBRARY)
- set(MPI_FOUND FALSE CACHE INTERNAL "Whether MPI was found" FORCE)
- endif (MPI_LIBRARY)
-endif (NOT MPI_FORCE_RECONFIGURE)
+endif (MPI_INCLUDE_PATH AND MPI_LIBRARY)
# on BlueGene/L the MPI lib is named libmpich.rts.a, there also these additional libs are required
if("${MPI_LIBRARY}" MATCHES "mpich.rts")
@@ -221,10 +245,22 @@ if("${MPI_LIBRARY}" MATCHES "mpich.rts")
set(MPI_LIBRARY ${MPI_LIBRARY} msglayer.rts devices.rts rts.rts devices.rts)
endif("${MPI_LIBRARY}" MATCHES "mpich.rts")
-set(MPI_LIBRARY ${MPI_LIBRARY} CACHE INTERNAL "MPI library to link against. Deprecated: use MPI_LIBRARIES instead")
-set(MPI_EXTRA_LIBRARY ${MPI_EXTRA_LIBRARY} CACHE INTERNAL "Second MPI library to link against. Deprecated: use MPI_LIBRARIES instead")
+# Set up extra variables to conform to
+if (MPI_EXTRA_LIBRARY)
+ set(MPI_LIBRARIES ${MPI_LIBRARY} ${MPI_EXTRA_LIBRARY})
+else (MPI_EXTRA_LIBRARY)
+ 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)
+ set(MPI_FOUND FALSE)
+endif (MPI_INCLUDE_PATH AND MPI_LIBRARY)
include(FindPackageHandleStandardArgs)
# handle the QUIETLY and REQUIRED arguments
find_package_handle_standard_args(MPI DEFAULT_MSG MPI_LIBRARY MPI_INCLUDE_PATH)
-mark_as_advanced(MPI_INCLUDE_PATH MPI_COMPILE_FLAGS MPI_LINK_FLAGS MPI_LIBRARIES)
+
+mark_as_advanced(MPI_INCLUDE_PATH MPI_COMPILE_FLAGS MPI_LINK_FLAGS MPI_LIBRARY
+ MPI_EXTRA_LIBRARY)
--
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