Generate Python bindings with CFFI in API mode

.gitignore

@@ -3,3 +3,5 @@ build*/
 __pycache__/
 venv/
 .cache/
+.direnv/
+.ccls-cache/

.travis.yml

@@ -1,69 +1,79 @@
-language: python
-
 sudo: false
 
+dist: bionic
+
+env:
+  global:
+    - PIPENV_IGNORE_VIRTUALENVS=1
+    - PATH=$HOME/Deps/cmake/bin${PATH:+:$PATH}
+
 matrix:
   include:
-    - os: linux
-      compiler: gcc
-      addons: &gcc49
+    - name: "Context API example on Linux"
+      os: linux
+      language: python
+      python: 3.7
+      addons:
         apt:
-          sources: ['ubuntu-toolchain-r-test']
-          packages: ['g++-4.9', 'gcc-4.9', 'gfortran-4.9']
+          packages: ['gfortran']
       env:
-        - CXX='g++-4.9'
-        - CC='gcc-4.9'
-        - FC='gfortran-4.9'
-      python: 2.7
-    - os: linux
-      compiler: gcc
-      addons: &gcc49
-        apt:
-          sources: ['ubuntu-toolchain-r-test']
-          packages: ['g++-4.9', 'gcc-4.9', 'gfortran-4.9']
+        - CXX_COMPILER='g++'
+        - C_COMPILER='gcc'
+        - FC_COMPILER='gfortran'
+    - name: "Context API example on macOS"
+      os: osx
+      osx_image: xcode11.2  # Python 3.7.4 running on macOS 10.14.4
+      language: shell       # 'language: python' is an error on Travis CI macOS
+      addons:
+        homebrew:
+          packages:
+            - gcc
+            - cmake
       env:
-        - CXX='g++-4.9'
-        - CC='gcc-4.9'
-        - FC='gfortran-4.9'
-      python: 3.6
-    - os: osx
-      osx_image: xcode7.3
-      compiler: gcc
-      sudo: required
-      language: generic
+        - CXX_COMPILER='g++'
+        - C_COMPILER='gcc'
+        - FC_COMPILER='gfortran'
+
+before_install:
+  - mkdir -p $HOME/Downloads $HOME/Deps
 
 install:
   - |
-    if [[ "${TRAVIS_OS_NAME}" == "osx" ]]; then
-        # manually install python on osx
-        brew update &> /dev/null
-        brew install python3
-        brew reinstall gcc
-        virtualenv venv
-        source venv/bin/activate
-        pip install -r requirements.txt --upgrade
+    if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
+      CMAKE_VERSION="3.14.7"
+      echo "-- Installing CMake ${CMAKE_VERSION}"
+      target_path=$HOME/Deps/cmake
+      cmake_url="https://cmake.org/files/v${CMAKE_VERSION%.*}/cmake-${CMAKE_VERSION}-Linux-x86_64.tar.gz"
+      mkdir -p "$target_path"
+      curl -Ls "$cmake_url" | tar -xz -C "$target_path" --strip-components=1
+      echo "-- Done with CMake ${CMAKE_VERSION}"
     fi
-  - pip install -r requirements.txt --upgrade
-  - python --version
+  - pip install --upgrade pip
+  - pip install -U pipenv
+  - pipenv install --dev 
 
 before_script:
-  - pycodestyle account/
-  - pycodestyle test/test.py
+  - test -n $CXX && unset CXX
+  - test -n $CC && unset CC
+  - test -n $FC && unset FC
 
 script:
-  - mkdir build
+  - pipenv run pycodestyle account/
+  - pipenv run pycodestyle test/test_account.py
+  - pipenv run cmake -H. -Bbuild -DCMAKE_CXX_COMPILER=${CXX_COMPILER} -DCMAKE_C_COMPILER=${C_COMPILER} -DCMAKE_Fortran_COMPILER=${FC_COMPILER}
+  - pipenv run cmake --build build -- VERBOSE=1
   - cd build
-  - cmake ..
-  - make
-  - make test
+  - ctest
+  - pipenv run python -m pytest -rws -vv lib/python3.7
   - cd ..
-  - ACCOUNT_LIBRARY_DIR=$PWD/build/lib ACCOUNT_INCLUDE_DIR=$PWD/account PYTHONPATH=$PWD pytest -vv test/test.py
+# in the remaining part test that we can pip install the code
   - mkdir test-setup-script
   - cd test-setup-script
   - virtualenv venv
   - source venv/bin/activate
-  - pip install git+https://github.com/bast/context-api-example.git
+  - pip install /home/travis/build/dev-cafe/context-api-example/
   - python -c 'import account'
+  - deactivate
 
 notifications:
   email: false

CMakeLists.txt

@@ -1,14 +1,28 @@
 # define minimum cmake version
-cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.14)
 
 # project name and supported languages
-project(example CXX Fortran)
+project(example LANGUAGES CXX Fortran C)
+
+include(GNUInstallDirs)
 
 # require C++11
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+# require C99
+set(CMAKE_C_STANDARD 99)
+set(CMAKE_C_EXTENSIONS OFF)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+
+# specify where to place libraries
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
+
+# Python is required to get the Python interface working
+find_package(Python 3.7 REQUIRED COMPONENTS Development Interpreter)
+file(TO_NATIVE_PATH "lib/python${Python_VERSION_MAJOR}.${Python_VERSION_MINOR}/account" PYMOD_INSTALL_FULLDIR)
+
 # interface and sources
 add_subdirectory(account)
 

Pipfile

@@ -0,0 +1,11 @@
+[[source]]
+name = "pypi"
+url = "https://pypi.org/simple"
+verify_ssl = true
+
+[dev-packages]
+pytest = "*"
+cffi = "*"
+pycodestyle = "*"
+
+[packages]

account/CMakeLists.txt

@@ -1,16 +1,121 @@
-# specify where to place libraries
-set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
+# Get file extension for Python module
+execute_process(
+  COMMAND
+    "${Python_EXECUTABLE}" "-c" "from distutils import sysconfig as s;print(s.get_config_var('EXT_SUFFIX'))"
+  RESULT_VARIABLE _PYTHON_SUCCESS
+  OUTPUT_VARIABLE Python_MODULE_EXTENSION
+  ERROR_VARIABLE _PYTHON_ERROR_VALUE
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+
+# Call CFFI to generate bindings source file _account.cc
+file(MAKE_DIRECTORY ${PROJECT_BINARY_DIR}/generated)
+add_custom_command(
+  OUTPUT
+    ${PROJECT_BINARY_DIR}/generated/_account.c
+  COMMAND
+    ${Python_EXECUTABLE} ${CMAKE_CURRENT_LIST_DIR}/builder.py
+  MAIN_DEPENDENCY
+    ${CMAKE_CURRENT_LIST_DIR}/builder.py
+  DEPENDS
+    ${CMAKE_CURRENT_LIST_DIR}/account.f90
+    ${CMAKE_CURRENT_LIST_DIR}/account.h
+  WORKING_DIRECTORY
+    ${PROJECT_BINARY_DIR}/generated
+  )
+
+add_custom_target(
+  cffi-builder
+  ALL
+  DEPENDS
+    ${PROJECT_BINARY_DIR}/generated/_account.c
+  )
+
+Python_add_library(_account
+  MODULE
+    account.f90
+    ${PROJECT_BINARY_DIR}/generated/_account.c
+  )
+
+add_dependencies(_account cffi-builder)
+
+# generate account_export.h
+include(GenerateExportHeader)
+generate_export_header(_account
+  BASE_NAME account
+  )
+
+target_include_directories(_account
+  PRIVATE
+    ${CMAKE_CURRENT_LIST_DIR}  # where account.h lives
+    ${CMAKE_CURRENT_BINARY_DIR}  # where lsdalton_py_export.h lives
+  )
 
 # implementation sources
 add_subdirectory(implementation)
 
+target_link_libraries(_account
+  PUBLIC
+    account_fortran_implementation
+  )
+
 # fortran interface
 add_library(fortran_c_interface account.f90)
 
-install(
-    FILES
-        account.h
-        account.f90
-    DESTINATION
-        include
+# RPATH fixing
+file(RELATIVE_PATH _rel ${CMAKE_INSTALL_PREFIX}/${PYMOD_INSTALL_FULLDIR} ${CMAKE_INSTALL_PREFIX})
+if(APPLE)
+  set(_RPATH "@loader_path/${_rel}")
+else()
+  set(_RPATH "\$ORIGIN/${_rel}")
+endif()
+
+# List of Python files around the compiled extension
+list(APPEND _pys
+  ${CMAKE_CURRENT_SOURCE_DIR}/__init__.py
+  ${CMAKE_CURRENT_SOURCE_DIR}/shim.py
+  )
+
+set_target_properties(_account
+  PROPERTIES
+    SUFFIX "${Python_MODULE_EXTENSION}"
+    MACOSX_RPATH ON
+    SKIP_BUILD_RPATH OFF
+    BUILD_WITH_INSTALL_RPATH OFF
+    INSTALL_RPATH "${_RPATH}${CMAKE_INSTALL_LIBDIR}"
+    INSTALL_RPATH_USE_LINK_PATH ON
+    LIBRARY_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/${PYMOD_INSTALL_FULLDIR}
+    RESOURCE "${_pys}"
+  )
+
+# Create symlinks into build tree
+file(MAKE_DIRECTORY ${PROJECT_BINARY_DIR}/${PYMOD_INSTALL_FULLDIR})
+foreach(_py IN LISTS _pys)
+  get_filename_component(__py ${_py} NAME)
+  file(
+    CREATE_LINK
+      ${_py}
+      ${PROJECT_BINARY_DIR}/${PYMOD_INSTALL_FULLDIR}/${__py}
+    SYMBOLIC
     )
+endforeach()
+
+install(
+  FILES
+    account.h
+    account.f90
+    ${CMAKE_CURRENT_BINARY_DIR}/account_export.h
+  DESTINATION
+    ${CMAKE_INSTALL_INCLUDEDIR}
+  )
+
+install(
+  TARGETS
+    _account
+  LIBRARY
+    DESTINATION ${PYMOD_INSTALL_FULLDIR}/lib
+  RUNTIME
+    DESTINATION ${PYMOD_INSTALL_FULLDIR}/lib
+  RESOURCE
+    DESTINATION ${PYMOD_INSTALL_FULLDIR}
+  )

account/__init__.py

@@ -1,34 +1,5 @@
-from .cffi_helpers import get_lib_handle
-import os
-import sys
+from .shim import *
 
-
-def get_env(v):
-    _v = os.getenv(v)
-    if _v is None:
-        sys.stderr.write('ERROR: variable {0} is undefined\n'.format(v))
-        sys.exit(1)
-    return _v
-
-
-_this_path = os.path.dirname(os.path.realpath(__file__))
-
-_library_dir = os.getenv('ACCOUNT_LIBRARY_DIR')
-if _library_dir is None:
-    _library_dir = os.path.join(_this_path, 'lib')
-
-_include_dir = os.getenv('ACCOUNT_INCLUDE_DIR')
-if _include_dir is None:
-    _include_dir = os.path.join(_this_path, 'include')
-
-c_lib = get_lib_handle(['-DACCOUNT_API=', '-DACCOUNT_NOINCLUDE'],
-                       'account.h',
-                       'account_cpp_implementation',
-                       _library_dir,
-                       _include_dir)
-
-f_lib = get_lib_handle(['-DACCOUNT_API=', '-DACCOUNT_NOINCLUDE'],
-                       'account.h',
-                       'account_fortran_implementation',
-                       _library_dir,
-                       _include_dir)
+__all__ = [
+    "Account",
+]

account/account.h

@@ -1,12 +1,15 @@
-#pragma once
+/* CFFI would issue warning with pragma once */
+#ifndef ACCOUNT_H_INCLUDED
+#define ACCOUNT_H_INCLUDED
 
 #ifndef ACCOUNT_API
 #include "account_export.h"
 #define ACCOUNT_API ACCOUNT_EXPORT
 #endif
 
 #ifdef __cplusplus
-extern "C" {
+extern "C"
+{
 #endif
 
 struct account_context;
@@ -30,3 +33,5 @@ double account_get_balance(const account_context_t *context);
 #ifdef __cplusplus
 }
 #endif
+
+#endif /* ACCOUNT_H_INCLUDED */