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@mirkow
Created March 19, 2017 14:28
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Modified FindOpenMP to work with Clang 3.8 under Ubuntu 14.04
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#.rst:
# FindOpenMP
# ----------
#
# Finds OpenMP support
#
# This module can be used to detect OpenMP support in a compiler. If
# the compiler supports OpenMP, the flags required to compile with
# OpenMP support are returned in variables for the different languages.
# The variables may be empty if the compiler does not need a special
# flag to support OpenMP.
#
# The following variables are set:
#
# ``OpenMP_C_FLAGS``
# Flags to add to the C compiler for OpenMP support.
# ``OpenMP_CXX_FLAGS``
# Flags to add to the CXX compiler for OpenMP support.
# ``OpenMP_Fortran_FLAGS``
# Flags to add to the Fortran compiler for OpenMP support.
# ``OPENMP_FOUND``
# True if openmp is detected.
#
# The following internal variables are set, if detected:
#
# ``OpenMP_C_SPEC_DATE``
# Specification date of OpenMP version of C compiler.
# ``OpenMP_CXX_SPEC_DATE``
# Specification date of OpenMP version of CXX compiler.
# ``OpenMP_Fortran_SPEC_DATE``
# Specification date of OpenMP version of Fortran compiler.
#
# The specification dates are formatted as integers of the form
# ``CCYYMM`` where these represent the decimal digits of the century,
# year, and month.
message(STATUS "Looking for OPENMP")
set(_OPENMP_REQUIRED_VARS)
set(CMAKE_REQUIRED_QUIET_SAVE ${CMAKE_REQUIRED_QUIET})
set(CMAKE_REQUIRED_QUIET ${OpenMP_FIND_QUIETLY})
function(_OPENMP_FLAG_CANDIDATES LANG)
set(OpenMP_FLAG_CANDIDATES
#Empty, if compiler automatically accepts openmp
" "
#GNU
"-fopenmp"
#Clang
"-fopenmp=libiomp5"
"-fopenmp=libomp"
#Microsoft Visual Studio
"/openmp"
#Intel windows
"-Qopenmp"
#PathScale, Intel
"-openmp"
#Sun
"-xopenmp"
#HP
"+Oopenmp"
#IBM XL C/c++
"-qsmp"
#Portland Group, MIPSpro
"-mp"
)
set(OMP_FLAG_GNU "-fopenmp")
set(OMP_FLAG_Clang "-fopenmp=libomp")
set(OMP_FLAG_HP "+Oopenmp")
if(WIN32)
set(OMP_FLAG_Intel "-Qopenmp")
elseif(CMAKE_${LANG}_COMPILER_ID STREQUAL "Intel" AND
"${CMAKE_${LANG}_COMPILER_VERSION}" VERSION_LESS "15.0.0.20140528")
set(OMP_FLAG_Intel "-openmp")
else()
set(OMP_FLAG_Intel "-qopenmp")
endif()
set(OMP_FLAG_MIPSpro "-mp")
set(OMP_FLAG_MSVC "/openmp")
set(OMP_FLAG_PathScale "-openmp")
set(OMP_FLAG_PGI "-mp")
set(OMP_FLAG_SunPro "-xopenmp")
set(OMP_FLAG_XL "-qsmp")
set(OMP_FLAG_Cray " ")
# Move the flag that matches the compiler to the head of the list,
# this is faster and doesn't clutter the output that much. If that
# flag doesn't work we will still try all.
if(OMP_FLAG_${CMAKE_${LANG}_COMPILER_ID})
list(REMOVE_ITEM OpenMP_FLAG_CANDIDATES "${OMP_FLAG_${CMAKE_${LANG}_COMPILER_ID}}")
list(INSERT OpenMP_FLAG_CANDIDATES 0 "${OMP_FLAG_${CMAKE_${LANG}_COMPILER_ID}}")
endif()
set(OpenMP_${LANG}_FLAG_CANDIDATES "${OpenMP_FLAG_CANDIDATES}" PARENT_SCOPE)
endfunction()
# sample openmp source code to test
set(OpenMP_C_TEST_SOURCE
"
#include <omp.h>
int main() {
#ifdef _OPENMP
return 0;
#else
breaks_on_purpose
#endif
}
")
# same in Fortran
set(OpenMP_Fortran_TEST_SOURCE
"
program test
use omp_lib
integer :: n
n = omp_get_num_threads()
end program test
"
)
set(OpenMP_C_CXX_CHECK_VERSION_SOURCE
"
#include <stdio.h>
#include <omp.h>
const char ompver_str[] = { 'I', 'N', 'F', 'O', ':', 'O', 'p', 'e', 'n', 'M',
'P', '-', 'd', 'a', 't', 'e', '[',
('0' + ((_OPENMP/100000)%10)),
('0' + ((_OPENMP/10000)%10)),
('0' + ((_OPENMP/1000)%10)),
('0' + ((_OPENMP/100)%10)),
('0' + ((_OPENMP/10)%10)),
('0' + ((_OPENMP/1)%10)),
']', '\\0' };
int main(int argc, char *argv[])
{
printf(\"%s\\n\", ompver_str);
return 0;
}
")
set(OpenMP_Fortran_CHECK_VERSION_SOURCE
"
program omp_ver
use omp_lib
integer, parameter :: zero = ichar('0')
integer, parameter :: ompv = openmp_version
character, dimension(24), parameter :: ompver_str =&
(/ 'I', 'N', 'F', 'O', ':', 'O', 'p', 'e', 'n', 'M', 'P', '-',&
'd', 'a', 't', 'e', '[',&
char(zero + mod(ompv/100000, 10)),&
char(zero + mod(ompv/10000, 10)),&
char(zero + mod(ompv/1000, 10)),&
char(zero + mod(ompv/100, 10)),&
char(zero + mod(ompv/10, 10)),&
char(zero + mod(ompv/1, 10)), ']' /)
print *, ompver_str
end program omp_ver
")
function(_OPENMP_GET_SPEC_DATE LANG SPEC_DATE)
set(WORK_DIR ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/FindOpenMP)
if("${LANG}" STREQUAL "C")
set(SRC_FILE ${WORK_DIR}/ompver.c)
file(WRITE ${SRC_FILE} "${OpenMP_C_CXX_CHECK_VERSION_SOURCE}")
elseif("${LANG}" STREQUAL "CXX")
set(SRC_FILE ${WORK_DIR}/ompver.cpp)
file(WRITE ${SRC_FILE} "${OpenMP_C_CXX_CHECK_VERSION_SOURCE}")
else() # ("${LANG}" STREQUAL "Fortran")
set(SRC_FILE ${WORK_DIR}/ompver.f90)
file(WRITE ${SRC_FILE} "${OpenMP_Fortran_CHECK_VERSION_SOURCE}")
endif()
set(BIN_FILE ${WORK_DIR}/ompver_${LANG}.bin)
try_compile(OpenMP_TRY_COMPILE_RESULT ${CMAKE_BINARY_DIR} ${SRC_FILE}
CMAKE_FLAGS "-DCOMPILE_DEFINITIONS:STRING=${OpenMP_${LANG}_FLAGS}"
COPY_FILE ${BIN_FILE})
if(${OpenMP_TRY_COMPILE_RESULT})
file(STRINGS ${BIN_FILE} specstr LIMIT_COUNT 1 REGEX "INFO:OpenMP-date")
set(regex_spec_date ".*INFO:OpenMP-date\\[0*([^]]*)\\].*")
if("${specstr}" MATCHES "${regex_spec_date}")
set(${SPEC_DATE} "${CMAKE_MATCH_1}" PARENT_SCOPE)
endif()
endif()
unset(OpenMP_TRY_COMPILE_RESULT CACHE)
endfunction()
# check c compiler
if(CMAKE_C_COMPILER_LOADED)
# if these are set then do not try to find them again,
# by avoiding any try_compiles for the flags
if(OpenMP_C_FLAGS)
unset(OpenMP_C_FLAG_CANDIDATES)
else()
_OPENMP_FLAG_CANDIDATES("C")
include(CheckCSourceCompiles)
endif()
foreach(FLAG IN LISTS OpenMP_C_FLAG_CANDIDATES)
set(SAFE_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
set(CMAKE_REQUIRED_FLAGS "${FLAG}")
unset(OpenMP_FLAG_DETECTED CACHE)
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Try OpenMP C flag = [${FLAG}]")
endif()
check_c_source_compiles("${OpenMP_C_TEST_SOURCE}" OpenMP_FLAG_DETECTED)
set(CMAKE_REQUIRED_FLAGS "${SAFE_CMAKE_REQUIRED_FLAGS}")
if(OpenMP_FLAG_DETECTED)
set(OpenMP_C_FLAGS_INTERNAL "${FLAG}")
break()
endif()
endforeach()
set(OpenMP_C_FLAGS "${OpenMP_C_FLAGS_INTERNAL}"
CACHE STRING "C compiler flags for OpenMP parallization")
list(APPEND _OPENMP_REQUIRED_VARS OpenMP_C_FLAGS)
unset(OpenMP_C_FLAG_CANDIDATES)
if (NOT OpenMP_C_SPEC_DATE)
_OPENMP_GET_SPEC_DATE("C" OpenMP_C_SPEC_DATE_INTERNAL)
set(OpenMP_C_SPEC_DATE "${OpenMP_C_SPEC_DATE_INTERNAL}" CACHE
INTERNAL "C compiler's OpenMP specification date")
endif()
endif()
# check cxx compiler
if(CMAKE_CXX_COMPILER_LOADED)
# if these are set then do not try to find them again,
# by avoiding any try_compiles for the flags
if(OpenMP_CXX_FLAGS)
unset(OpenMP_CXX_FLAG_CANDIDATES)
else()
_OPENMP_FLAG_CANDIDATES("CXX")
include(CheckCXXSourceCompiles)
# use the same source for CXX as C for now
set(OpenMP_CXX_TEST_SOURCE ${OpenMP_C_TEST_SOURCE})
endif()
foreach(FLAG IN LISTS OpenMP_CXX_FLAG_CANDIDATES)
set(SAFE_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
set(CMAKE_REQUIRED_FLAGS "${FLAG}")
unset(OpenMP_FLAG_DETECTED CACHE)
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Try OpenMP CXX flag = [${FLAG}]")
endif()
check_cxx_source_compiles("${OpenMP_CXX_TEST_SOURCE}" OpenMP_FLAG_DETECTED)
set(CMAKE_REQUIRED_FLAGS "${SAFE_CMAKE_REQUIRED_FLAGS}")
if(OpenMP_FLAG_DETECTED)
set(OpenMP_CXX_FLAGS_INTERNAL "${FLAG}")
break()
endif()
endforeach()
set(OpenMP_CXX_FLAGS "${OpenMP_CXX_FLAGS_INTERNAL}"
CACHE STRING "C++ compiler flags for OpenMP parallization")
list(APPEND _OPENMP_REQUIRED_VARS OpenMP_CXX_FLAGS)
unset(OpenMP_CXX_FLAG_CANDIDATES)
if (NOT OpenMP_CXX_SPEC_DATE)
_OPENMP_GET_SPEC_DATE("CXX" OpenMP_CXX_SPEC_DATE_INTERNAL)
set(OpenMP_CXX_SPEC_DATE "${OpenMP_CXX_SPEC_DATE_INTERNAL}" CACHE
INTERNAL "C++ compiler's OpenMP specification date")
endif()
endif()
# check Fortran compiler
if(CMAKE_Fortran_COMPILER_LOADED)
# if these are set then do not try to find them again,
# by avoiding any try_compiles for the flags
if(OpenMP_Fortran_FLAGS)
unset(OpenMP_Fortran_FLAG_CANDIDATES)
else()
_OPENMP_FLAG_CANDIDATES("Fortran")
include(${CMAKE_CURRENT_LIST_DIR}/CheckFortranSourceCompiles.cmake)
endif()
foreach(FLAG IN LISTS OpenMP_Fortran_FLAG_CANDIDATES)
set(SAFE_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
set(CMAKE_REQUIRED_FLAGS "${FLAG}")
unset(OpenMP_FLAG_DETECTED CACHE)
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Try OpenMP Fortran flag = [${FLAG}]")
endif()
check_fortran_source_compiles("${OpenMP_Fortran_TEST_SOURCE}" OpenMP_FLAG_DETECTED)
set(CMAKE_REQUIRED_FLAGS "${SAFE_CMAKE_REQUIRED_FLAGS}")
if(OpenMP_FLAG_DETECTED)
set(OpenMP_Fortran_FLAGS_INTERNAL "${FLAG}")
break()
endif()
endforeach()
set(OpenMP_Fortran_FLAGS "${OpenMP_Fortran_FLAGS_INTERNAL}"
CACHE STRING "Fortran compiler flags for OpenMP parallization")
list(APPEND _OPENMP_REQUIRED_VARS OpenMP_Fortran_FLAGS)
unset(OpenMP_Fortran_FLAG_CANDIDATES)
if (NOT OpenMP_Fortran_SPEC_DATE)
_OPENMP_GET_SPEC_DATE("Fortran" OpenMP_Fortran_SPEC_DATE_INTERNAL)
set(OpenMP_Fortran_SPEC_DATE "${OpenMP_Fortran_SPEC_DATE_INTERNAL}" CACHE
INTERNAL "Fortran compiler's OpenMP specification date")
endif()
endif()
set(CMAKE_REQUIRED_QUIET ${CMAKE_REQUIRED_QUIET_SAVE})
if(_OPENMP_REQUIRED_VARS)
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(OpenMP
REQUIRED_VARS ${_OPENMP_REQUIRED_VARS})
mark_as_advanced(${_OPENMP_REQUIRED_VARS})
unset(_OPENMP_REQUIRED_VARS)
else()
message(SEND_ERROR "FindOpenMP requires C or CXX language to be enabled")
endif()
unset(OpenMP_C_TEST_SOURCE)
unset(OpenMP_CXX_TEST_SOURCE)
unset(OpenMP_Fortran_TEST_SOURCE)
unset(OpenMP_C_CXX_CHECK_VERSION_SOURCE)
unset(OpenMP_Fortran_CHECK_VERSION_SOURCE)
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