From 353178c7bb964f9f9ea86fb46571be393fb39245 Mon Sep 17 00:00:00 2001
From: Radovan Bast <bast@users.noreply.github.com>
Date: Sun, 13 May 2018 17:17:31 +0200
Subject: [PATCH] refactor OpenMP module; fixes #247

changes:
- append flags if either OPENMP_FOUND OR OpenMP_${_lang}_FOUND
- do not set OPENMP_FOUND
- make version dependence of workaround for CMake < 3.5 more explicit
- do not add_definitions(-DHAVE_OPENMP)
- rename to omp-flags.cmake to be more explicit and to not silently
  drop -DHAVE_OPENMP
---
 modules/omp-flags.cmake | 66 ++++++++++++++++++++++++++++++++++++++
 modules/omp.cmake       | 71 -----------------------------------------
 2 files changed, 66 insertions(+), 71 deletions(-)
 create mode 100644 modules/omp-flags.cmake
 delete mode 100644 modules/omp.cmake

diff --git a/modules/omp-flags.cmake b/modules/omp-flags.cmake
new file mode 100644
index 0000000..a387f05
--- /dev/null
+++ b/modules/omp-flags.cmake
@@ -0,0 +1,66 @@
+# (c) https://github.com/coderefinery/autocmake/blob/master/AUTHORS.md
+# licensed under BSD-3: https://github.com/coderefinery/autocmake/blob/master/LICENSE
+
+#.rst:
+#
+# Enables OpenMP support.
+#
+# Variables used::
+#
+#   ENABLE_OPENMP
+#   OPENMP_FOUND
+#
+# Variables modified (provided the corresponding language is enabled)::
+#
+#   CMAKE_Fortran_FLAGS
+#   CMAKE_C_FLAGS
+#   CMAKE_CXX_FLAGS
+#
+# autocmake.yml configuration::
+#
+#   docopt: "--omp Enable OpenMP parallelization [default: False]."
+#   define: "'-DENABLE_OPENMP={0}'.format(arguments['--omp'])"
+
+option(ENABLE_OPENMP "Enable OpenMP parallelization" OFF)
+
+if(ENABLE_OPENMP)
+
+    if(NOT OPENMP_FOUND)
+        find_package(OpenMP)
+    endif()
+
+    foreach(_lang C CXX Fortran)
+        if(DEFINED CMAKE_${_lang}_COMPILER_ID)
+            if(OPENMP_FOUND OR OpenMP_${_lang}_FOUND)
+                set(CMAKE_${_lang}_FLAGS "${CMAKE_${_lang}_FLAGS} ${OpenMP_${_lang}_FLAGS}")
+            endif()
+        endif()
+    endforeach()
+
+    if(CMAKE_VERSION VERSION_LESS "3.5")
+        if(DEFINED CMAKE_Fortran_COMPILER_ID AND NOT DEFINED OpenMP_Fortran_FLAGS)
+            # we do this in a pedestrian way because the Fortran support is relatively recent
+            if(CMAKE_Fortran_COMPILER_ID MATCHES GNU)
+                set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -fopenmp")
+            endif()
+            if(CMAKE_Fortran_COMPILER_ID MATCHES Intel)
+                if(WIN32)
+                    set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -Qopenmp")
+                elseif("${CMAKE_Fortran_COMPILER_VERSION}" VERSION_LESS "15.0.0.20140528")
+                    set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -openmp")
+                else()
+                    set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -qopenmp")
+                endif()
+            endif()
+            if(CMAKE_Fortran_COMPILER_ID MATCHES PGI)
+                set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -mp")
+            endif()
+            if(CMAKE_Fortran_COMPILER_ID MATCHES XL)
+                set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -qsmp=omp")
+            endif()
+            if(CMAKE_Fortran_COMPILER_ID MATCHES Cray)
+                # do nothing in this case
+            endif()
+        endif()
+    endif()
+endif()
diff --git a/modules/omp.cmake b/modules/omp.cmake
deleted file mode 100644
index f63d8de..0000000
--- a/modules/omp.cmake
+++ /dev/null
@@ -1,71 +0,0 @@
-# (c) https://github.com/coderefinery/autocmake/blob/master/AUTHORS.md
-# licensed under BSD-3: https://github.com/coderefinery/autocmake/blob/master/LICENSE
-
-#.rst:
-#
-# Enables OpenMP support.
-#
-# Variables used::
-#
-#   ENABLE_OPENMP
-#   OPENMP_FOUND
-#
-# Variables modified (provided the corresponding language is enabled)::
-#
-#   CMAKE_Fortran_FLAGS
-#   CMAKE_C_FLAGS
-#   CMAKE_CXX_FLAGS
-#
-# autocmake.yml configuration::
-#
-#   docopt: "--omp Enable OpenMP parallelization [default: False]."
-#   define: "'-DENABLE_OPENMP={0}'.format(arguments['--omp'])"
-
-option(ENABLE_OPENMP "Enable OpenMP parallelization" OFF)
-
-if(ENABLE_OPENMP)
-
-    if(NOT OPENMP_FOUND)
-        find_package(OpenMP)
-    endif()
-
-    if(OPENMP_FOUND)
-        add_definitions(-DHAVE_OPENMP)
-        if(DEFINED CMAKE_C_COMPILER_ID)
-            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
-        endif()
-        if(DEFINED CMAKE_CXX_COMPILER_ID)
-            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
-        endif()
-        if(DEFINED CMAKE_Fortran_COMPILER_ID)
-            set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} ${OpenMP_Fortran_FLAGS}")
-        endif()
-    endif()
-
-    # this is only needed for CMake below 3.5
-    if(DEFINED CMAKE_Fortran_COMPILER_ID AND NOT DEFINED OpenMP_Fortran_FLAGS)
-        # we do this in a pedestrian way because the Fortran support is relatively recent
-        if(CMAKE_Fortran_COMPILER_ID MATCHES GNU)
-            set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -fopenmp")
-        endif()
-        if(CMAKE_Fortran_COMPILER_ID MATCHES Intel)
-            if(WIN32)
-                set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -Qopenmp")
-            elseif("${CMAKE_Fortran_COMPILER_VERSION}" VERSION_LESS "15.0.0.20140528")
-                set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -openmp")
-            else()
-                set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -qopenmp")
-            endif()
-        endif()
-        if(CMAKE_Fortran_COMPILER_ID MATCHES PGI)
-            set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -mp")
-        endif()
-        if(CMAKE_Fortran_COMPILER_ID MATCHES XL)
-            set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -qsmp=omp")
-        endif()
-        if(CMAKE_Fortran_COMPILER_ID MATCHES Cray)
-            # do nothing in this case
-        endif()
-        set(OPENMP_FOUND TRUE)
-    endif()
-endif()