improve layout

Author: scivision

CMakeLists.txt

@@ -1,29 +1,8 @@
-# Demonstrate linking of
-# * C++ calling Fortran
-# * Fortran calling C++
-# * Fortran calling C
-#
-# https://stackoverflow.com/tags/fortran-iso-c-binding/info
-#
-# this also works between ABI compatible compilers
-# e.g. Clang and GCC.
-#
-# This also works for MacOS with Apple's Clang and Homebrew GCC,
-# by being sure you have in ~/.zshrc like the following:
-# (check directory / versions on your Mac)
-#
-# export LIBRARY_PATH=$LIBRARY_PATH:/Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk/usr/lib
-#
-# export CPLUS_INCLUDE_PATH=/Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk/usr/include
-# export CXXFLAGS=-I$CPLUS_INCLUDE_PATH
-# export CFLAGS=$CXXFLAGS
-#
-# in general, CMake >= 3.14 have better link resolution than CMake 3.13.
 cmake_minimum_required(VERSION 3.14...3.21)
 
 project(Fortran_C_CXX_interface
-LANGUAGES C Fortran CXX
-VERSION 1.1.1)
+LANGUAGES C CXX Fortran
+VERSION 1.2.0)
 
 include(CTest)
 
@@ -32,6 +11,4 @@ include (cmake/compilers.cmake)
 set(CMAKE_C_STANDARD 99)
 set(CMAKE_CXX_STANDARD 11)
 
-add_subdirectory(c)
-
-add_subdirectory(cxx)
+add_subdirectory(src)

CMakePresets.json

@@ -4,10 +4,7 @@
 "configurePresets": [
 {
   "name": "default",
-  "binaryDir": "${sourceDir}/build",
-  "cacheVariables": {
-    "CMAKE_BUILD_TYPE": "Release"
-  }
+  "binaryDir": "${sourceDir}/build"
 },
 {
   "name": "multi", "inherits": "default",

README.md

@@ -14,34 +14,34 @@ For example:
 * Clang and Gfortran
 * (Windows) MSVC and Intel oneAPI ifort
 
-## build
-
-```sh
-cmake -B build
+Demonstrate linking of
 
-cmake --build build
+* C++ calling Fortran
+* Fortran calling C++
+* Fortran calling C
 
-ctest --test-dir build
-```
+https://stackoverflow.com/tags/fortran-iso-c-binding/info
 
-## Example
+In general, CMake >= 3.14 has better link resolution than CMake 3.13.
+In general, strongly avoid the FortranCInterface of CMake and mangling function names--just use Fortran 2003 standard `bind(C)`
 
-```fortran
-module flibs
+## MacOS
 
-use,intrinsic:: iso_c_binding, only: c_int, c_float, c_double
+For MacOS with Apple's Clang and Homebrew GCC,
+be sure you have in ~/.zshrc like the following:
+(check directory / versions on your Mac)
 
-implicit none
+export LIBRARY_PATH=$LIBRARY_PATH:/Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk/usr/lib
+export CPLUS_INCLUDE_PATH=/Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk/usr/include
+export CXXFLAGS=-I$CPLUS_INCLUDE_PATH
+export CFLAGS=$CXXFLAGS
 
-subroutine cool(X,N) bind(c)
+## build
 
-real(c_double), intent(inout) :: X
-integer(c_int), intent(in) :: N
+```sh
+cmake -B build
 
-...
+cmake --build build
 
-end subroutine cool
+ctest --test-dir build
 ```
-
-`bind(c)` makes the name `cool` available to C/C++.
-In general, strongly avoid the FortranCInterface of CMake and mangling function names--just use Fortran 2003 standard `bind(C)`

c/CMakeLists.txt

@@ -1,11 +1,7 @@
 project('Fortran_c_cxx_interface', 'c', 'cpp', 'fortran',
-version : '1.1.1',
+version : '1.2.0',
 meson_version: '>= 0.52.0',
-default_options : ['default_library=static', 'buildtype=release', 'warning_level=3',
+default_options : ['default_library=static', 'warning_level=3',
 'cpp_std=c++11', 'c_std=c99'])
 
-fcc_src = files('f_call_c.f90')
-
-subdir('c')
-
-subdir('cxx')
+subdir('src')

c/meson.build

@@ -0,0 +1,26 @@
+add_subdirectory(c)
+
+add_subdirectory(cxx)
+
+add_subdirectory(fortran)
+
+# -- Fortran calling C++
+add_executable(fortran_call_cxx fortran/main.f90)
+target_link_libraries(fortran_call_cxx PRIVATE math_cxx)
+# LINKER_LANGUAGE option is necessary for ifort at least
+set_target_properties(fortran_call_cxx PROPERTIES LINKER_LANGUAGE Fortran)
+add_test(NAME Fortran_call_C++ COMMAND fortran_call_cxx)
+
+# -- Fortran calling C
+add_executable(fortran_call_c fortran/main.f90)
+target_link_libraries(fortran_call_c PRIVATE math_c)
+add_test(NAME Fortran_call_C COMMAND fortran_call_c)
+
+# -- C++ calling Fortran
+add_executable(cxx_call_fortran cxx/cxx_main.cxx)
+target_link_libraries(cxx_call_fortran PRIVATE math_fortran)
+add_test(NAME C++_call_Fortran COMMAND cxx_call_fortran)
+
+set_tests_properties(C++_call_Fortran Fortran_call_C Fortran_call_C++ PROPERTIES
+TIMEOUT 5
+)

cxx/CMakeLists.txt

@@ -0,0 +1 @@
+add_library(math_c OBJECT math.c)