Add install function for cpp_bindgen libs (#31)

Additional change: Bump CMake version to the latest release (to avoid doing small version increments), reason is a change in CMake 3.13.0 ("The install(TARGETS) command learned to install targets created outside the current directory.")

Author: havogt

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12.4)
+cmake_minimum_required(VERSION 3.14.5)
 # when increasing the minium required version, consider updating in examples as well
 
 file(STRINGS "version.txt" __CPP_BINDGEN_VERSION)

README.md

@@ -17,19 +17,15 @@ FetchContent_Declare(
   GIT_REPOSITORY https://github.com/GridTools/cpp_bindgen.git
   GIT_TAG        master # consider replacing master by a tagged version
 )
-FetchContent_GetProperties(cpp_bindgen)
-if(NOT cpp_bindgen_POPULATED)
-  FetchContent_Populate(cpp_bindgen)
-  add_subdirectory(${cpp_bindgen_SOURCE_DIR} ${cpp_bindgen_BINARY_DIR})
-endif()
+FetchContent_MakeAvailable(cpp_bindgen)
 ```
 
 See also https://github.com/GridTools/cpp_bindgen/tree/master/example/simple_fetch_content.
 
 ##### Requirements
 
 - Boost (1.65.1 or later)
-- CMake (3.12.4 or later)
+- CMake (3.14.5 or later)
 
 ##### Known issues
 

cmake/cpp_bindgen.cmake.in

@@ -26,7 +26,7 @@
 #  - <library_name>_c the C-bindings with <library_name> linked to it
 #  - <library_name>_fortran the Fortran-bindings with <library_name> linked to it
 
-include_guard()
+include_guard(GLOBAL)
 
 option(GT_ENABLE_BINDINGS_GENERATION "If turned off, bindings will not be generated." ON)
 
@@ -35,7 +35,7 @@ set(__CPP_BINDGEN_SOURCE_DIR @__CPP_BINDGEN_SOURCE_DIR@)
 set(__CPP_BINDGEN_INCLUDE_DIR @__CPP_BINDGEN_INCLUDE_DIR@)
 
 add_library(cpp_bindgen_interface INTERFACE)
-target_include_directories(cpp_bindgen_interface INTERFACE ${__CPP_BINDGEN_INCLUDE_DIR})
+target_include_directories(cpp_bindgen_interface INTERFACE $<BUILD_INTERFACE:${__CPP_BINDGEN_INCLUDE_DIR}> $<INSTALL_INTERFACE:include>)
 target_compile_features(cpp_bindgen_interface INTERFACE cxx_std_11)
 target_compile_definitions(cpp_bindgen_interface INTERFACE BOOST_PP_VARIADICS=1)
 if(CPP_BINDGEN_GT_LEGACY)
@@ -65,18 +65,25 @@ function(bindgen_enable_fortran_library target_name)
     set(__CPP_BINDGEN_CMAKE_DIR @__CPP_BINDGEN_CMAKE_DIR@)
 
     if(CMAKE_Fortran_COMPILER_LOADED)
-        if(NOT TARGET fortran_bindings_handle)
-            add_library(fortran_bindings_handle ${__CPP_BINDGEN_SOURCE_DIR}/cpp_bindgen/array_descriptor.f90 ${__CPP_BINDGEN_SOURCE_DIR}/cpp_bindgen/handle.f90)
-            target_link_libraries(fortran_bindings_handle PUBLIC cpp_bindgen_handle)
-            target_include_directories(fortran_bindings_handle PUBLIC ${CMAKE_CURRENT_BINARY_DIR})
-            include(${__CPP_BINDGEN_CMAKE_DIR}/fortran_helpers.cmake)
-            bindgen_enable_fortran_preprocessing_on_target(fortran_bindings_handle)
+        if(NOT TARGET cpp_bindgen_fortran_handle)
+            add_library(cpp_bindgen_fortran_handle ${__CPP_BINDGEN_SOURCE_DIR}/cpp_bindgen/array_descriptor.f90 ${__CPP_BINDGEN_SOURCE_DIR}/cpp_bindgen/handle.f90)
+            # the following variable is used to install the .mod files in install_cpp_bindgen_targets() and
+            # therefore needs to be available project-wide
+            set(CPP_BINDGEN_Fortran_MODULES_DIRECTORY ${CMAKE_BINARY_DIR}/cpp_bindgen_modules
+                CACHE INTERNAL "Directory for Fortran modules of cpp_bindgen")
+            set_target_properties(cpp_bindgen_fortran_handle PROPERTIES Fortran_MODULE_DIRECTORY ${CPP_BINDGEN_Fortran_MODULES_DIRECTORY})
+            target_link_libraries(cpp_bindgen_fortran_handle PUBLIC cpp_bindgen_handle)
+            target_include_directories(cpp_bindgen_fortran_handle INTERFACE $<BUILD_INTERFACE:${CPP_BINDGEN_Fortran_MODULES_DIRECTORY}> $<INSTALL_INTERFACE:include/>)
+            include(${__CPP_BINDGEN_CMAKE_DIR}/cpp_bindgen_fortran_helpers.cmake)
+            bindgen_enable_fortran_preprocessing_on_target(cpp_bindgen_fortran_handle)
         endif()
         if(NOT TARGET ${target_name}_fortran)
             set_source_files_properties(GT_${${target_name}_fortran_bindings_path} PROPERTIES GENERATED TRUE)
-            add_library(${target_name}_fortran EXCLUDE_FROM_ALL ${GT_${target_name}_fortran_bindings_path})
+            add_library(${target_name}_fortran EXCLUDE_FROM_ALL ${CPP_BINDGEN_${target_name}_fortran_bindings_path})
             target_link_libraries(${target_name}_fortran PUBLIC ${target_name})
-            target_link_libraries(${target_name}_fortran PUBLIC fortran_bindings_handle)
+            target_link_libraries(${target_name}_fortran PUBLIC cpp_bindgen_fortran_handle)
+            # location of .mod file (we cannot know the INSTALL_INTERFACE directory here)
+            target_include_directories(${target_name}_fortran PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>)
             add_dependencies(${target_name}_fortran ${target_name}_declarations)
         endif()
     elseif(NOT ${ARGN}) # internal: the second (optional) parameter can be used to surpress this fatal error
@@ -159,7 +166,41 @@ function(bindgen_add_library target_name)
     # bindings Fortran library
     # Export the name of the generated file. The variable needs to exist in the whole cmake!
     # Reason: see description of bindgen_enable_fortran_library().
-    set(GT_${target_name}_fortran_bindings_path ${bindings_fortran_decl_filename}
+    set(CPP_BINDGEN_${target_name}_fortran_bindings_path ${bindings_fortran_decl_filename}
         CACHE INTERNAL "Path to the generated Fortran file for ${target_name}")
     bindgen_enable_fortran_library(${target_name} TRUE)
 endfunction()
+
+# install_cpp_bindgen_targets()
+#
+# cpp_bindgen contains some generic files which are being built on first use of bindgen_add_library().
+# These libraries can be installed with this function which takes the same arguments
+# as install(TARGETS targets... [other-options]), except
+# - you must not specify "TARGETS targets..." but only all [other-options].
+# - if Fortran is enabled Fortran_MODULE_DESTINATION needs to be set to the location where Fortran modules
+#   should be installed to (e.g. include)
+function(install_cpp_bindgen_targets)
+    set(options)
+    set(oneValueArgs Fortran_MODULE_DESTINATION)
+    set(multiValueArgs TARGETS)
+    cmake_parse_arguments(ARG "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+    if(ARG_TARGETS)
+        message(FATAL_ERROR "install_cpp_bindgen_targets() must not be called with TARGETS argument.")
+    endif()
+
+    if(TARGET cpp_bindgen_fortran_handle) # Fortran is enabled, we need to install a mod file
+        if(ARG_Fortran_MODULE_DESTINATION)
+            install(DIRECTORY ${CPP_BINDGEN_Fortran_MODULES_DIRECTORY}/ DESTINATION ${ARG_Fortran_MODULE_DESTINATION})
+        else()
+            message(WARNING "Fortran_MODULE_DESTINATION was NOT specified, but Fortran was enabled. Modules files for
+                             cpp_bindgen won't be installed.")
+        endif()
+        install(TARGETS cpp_bindgen_fortran_handle ${ARG_UNPARSED_ARGUMENTS})
+    else()
+        if(ARG_Fortran_MODULE_DESTINATION)
+            message(WARNING "Fortran_MODULE_DESTINATION was specified, but Fortran is disabled.")
+        endif()
+    endif()
+    install(TARGETS cpp_bindgen_generator cpp_bindgen_handle cpp_bindgen_interface ${ARG_UNPARSED_ARGUMENTS})
+endfunction()

cmake/fortran_helpers.cmake renamed to cmake/cpp_bindgen_fortran_helpers.cmake

@@ -54,7 +54,7 @@ unset(__CPP_BINDGEN_INCLUDE_DIR)
 
 set(CMAKE_SOURCES
     "${PROJECT_SOURCE_DIR}/cmake/cpp_bindgen_generate.cmake"
-    "${PROJECT_SOURCE_DIR}/cmake/fortran_helpers.cmake"
+    "${PROJECT_SOURCE_DIR}/cmake/cpp_bindgen_fortran_helpers.cmake"
     "${PROJECT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/build-install/lib/cmake/cpp_bindgen.cmake"
     )
 set(CBINDINGS_SOURCES

cmake/export.cmake

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12.4)
+cmake_minimum_required(VERSION 3.14.5)
 project(simple_example LANGUAGES CXX C Fortran)
 
 # 1) find installed cpp_bindgen version

example/simple/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12.4)
+cmake_minimum_required(VERSION 3.14.5)
 project(simple_example_with_fetch_content LANGUAGES CXX Fortran)
 
 # 1) fetch cpp_bindgen from the repository
@@ -11,16 +11,28 @@ FetchContent_Declare(
   # GIT_REPOSITORY https://github.com/GridTools/cpp_bindgen.git
   # GIT_TAG        master # consider replacing master by a tagged version
 )
-# FetchContent_MakeAvailable(cpp_bindgen) for CMake >= 3.14, otherwise:
-FetchContent_GetProperties(cpp_bindgen)
-if(NOT cpp_bindgen_POPULATED)
-  FetchContent_Populate(cpp_bindgen)
-  add_subdirectory(${cpp_bindgen_SOURCE_DIR} ${cpp_bindgen_BINARY_DIR})
-endif()
+FetchContent_MakeAvailable(cpp_bindgen)
 
 # 2) create a library with bindings. This will generate the files simple.h and simple.f90 which can be included within C and Fortran. In CMake you can use them by linking against `simple_c`or `simple_fortran`.
 bindgen_add_library(simple SOURCES simple.cpp)
 
 # 3) link the generated library to a fortran executable
 add_executable(driver driver.f90)
 target_link_libraries(driver simple_fortran)
+
+# 4) optional: demonstrates installing the library with CMake
+# installs general cpp_bindgen targets
+install_cpp_bindgen_targets(
+  EXPORT simple_fortran_targets
+  Fortran_MODULE_DESTINATION include
+  LIBRARY DESTINATION lib
+  ARCHIVE DESTINATION lib
+  )
+# install your library (simple) and the generated bindings library (simple_fortran) as usual
+install(
+  TARGETS simple simple_fortran
+  EXPORT simple_fortran_targets
+  LIBRARY DESTINATION lib
+  ARCHIVE DESTINATION lib
+  )
+install(EXPORT simple_fortran_targets DESTINATION cmake NAMESPACE SimpleFortran::)

example/simple_fetch_content/CMakeLists.txt

@@ -53,6 +53,8 @@
 #define GT_EXPORT_BINDING_8(...) BINDGEN_EXPORT_BINDING_8(__VA_ARGS__)
 #define GT_EXPORT_BINDING_9(...) BINDGEN_EXPORT_BINDING_9(__VA_ARGS__)
 
+#define GT_EXPORT_BINDING_WRAPPED(...) BINDGEN_EXPORT_BINDING_WRAPPED(__VA_ARGS__)
+
 #define GT_EXPORT_BINDING_WRAPPED_0(...) BINDGEN_EXPORT_BINDING_WRAPPED_0(__VA_ARGS__)
 #define GT_EXPORT_BINDING_WRAPPED_1(...) BINDGEN_EXPORT_BINDING_WRAPPED_1(__VA_ARGS__)
 #define GT_EXPORT_BINDING_WRAPPED_2(...) BINDGEN_EXPORT_BINDING_WRAPPED_2(__VA_ARGS__)

include/cpp_bindgen/export_gt_legacy.hpp

@@ -6,7 +6,7 @@ HOST=$(hostname)
 test -n "${CSCS_ACCOUNT}" || CSCS_ACCOUNT=d75
 
 if [[ "$HOST" == kesch* || "$HOST" == escha* ]]; then
-    module load cmake/3.13.4
+    module load /users/jenkins/easybuild/kesch/modules/all/cmake/3.14.5
     module load PE/17.06
     module load craype-haswell
     module load craype-network-infiniband
@@ -21,7 +21,7 @@ if [[ "$HOST" == kesch* || "$HOST" == escha* ]]; then
 elif [[ "$HOST" == tave* ]]; then
     module switch PrgEnv-cray PrgEnv-gnu
     module rm CMake
-    module load /users/jenkins/easybuild/tave/modules/all/CMake/3.12.4
+    module load /users/jenkins/easybuild/tave/modules/all/CMake/3.14.5
     export BOOST_ROOT=/project/c14/install/kesch/boost/boost_1_67_0
     RUN_PREFIX=""
 
@@ -30,7 +30,7 @@ elif [[ "$HOST" == daint* ]]; then
     module load cudatoolkit/9.2.148_3.19-6.0.7.1_2.1__g3d9acc8
     module switch PrgEnv-cray PrgEnv-gnu
     module rm CMake
-    module load /users/jenkins/easybuild/daint/haswell/modules/all/CMake/3.12.4
+    module load /users/jenkins/easybuild/daint/haswell/modules/all/CMake/3.14.5
     export BOOST_ROOT=/project/c14/install/daint/boost/boost_1_67_0
     export CUDA_ARCH=sm_60
     RUN_PREFIX="srun -C gpu -p cscsci --account=$CSCS_ACCOUNT --time=00:30:00"

jenkins/build.sh

@@ -7,11 +7,7 @@ FetchContent_Declare(
   GIT_REPOSITORY https://github.com/google/googletest.git
   GIT_TAG        release-1.8.1
 )
-FetchContent_GetProperties(googletest)
-if(NOT googletest_POPULATED)
-  FetchContent_Populate(googletest)
-  add_subdirectory(${googletest_SOURCE_DIR} ${googletest_BINARY_DIR})
-endif()
+FetchContent_MakeAvailable(googletest)
 
 include(${PROJECT_SOURCE_DIR}/cmake/detect_features.cmake)
 detect_cuda()