Add FindF2PY module

Co-authored-by: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com> Reviewed-by: Anthony Scopatz <scopatz@gmail.com>
gershnik · Feb 13, 2018 · bcce2e2 · bcce2e2
1 parent 9df5901
commit bcce2e2
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diff --git a/CHANGES.rst b/CHANGES.rst
@@ -8,6 +8,14 @@ details, see the commit logs at http://github.com/scikit-build/scikit-build
 Next Release
 ============
 
+New Features
+------------
+
+* Add CMake module :doc:`\cmake-modules/F2PY` useful to find the ``f2py`` executable for building Python
+  extensions with Fortran. Thanks to :user:`xoviat` for moving forward with the integration. Concept for the
+  module comes from the work of :user:`scopatz` done in `PyNE <https://github.com/pyne/pyne>`_ project.
+  See :issue:`273`.
+
 Bug fixes
 ---------
 

diff --git a/docs/cmake-modules.rst b/docs/cmake-modules.rst
@@ -12,6 +12,7 @@ CMake modules:
    cmake-modules/Cython
    cmake-modules/NumPy
    cmake-modules/PythonExtensions
+   cmake-modules/F2PY
 
 
 They can be included using ``find_package``:
@@ -21,6 +22,7 @@ They can be included using ``find_package``:
     find_package(Cython REQUIRED)
     find_package(NumPy REQUIRED)
     find_package(PythonExtensions REQUIRED)
+    find_package(F2PY REQUIRED)
 
 
 For more details, see the respective documentation of each modules.
diff --git a/docs/cmake-modules/F2PY.rst b/docs/cmake-modules/F2PY.rst
@@ -0,0 +1,4 @@
+F2PY
+----
+
+.. cmake-module:: ../../skbuild/resources/cmake/FindF2PY.cmake
diff --git a/skbuild/resources/cmake/FindF2PY.cmake b/skbuild/resources/cmake/FindF2PY.cmake
@@ -0,0 +1,91 @@
+#.rst:
+#
+# The purpose of the F2PY –Fortran to Python interface generator– project is to provide a
+# connection between Python and Fortran languages.
+#
+# F2PY is a Python package (with a command line tool f2py and a module f2py2e) that facilitates
+# creating/building Python C/API extension modules that make it possible to call Fortran 77/90/95
+# external subroutines and Fortran 90/95 module subroutines as well as C functions; to access Fortran
+# 77 COMMON blocks and Fortran 90/95 module data, including allocatable arrays from Python.
+#
+# For more information on the F2PY project, see http://www.f2py.com/.
+#
+# The following variables are defined:
+#
+# ::
+#
+#   F2PY_EXECUTABLE      - absolute path to the F2PY executable
+#
+# ::
+#
+#   F2PY_VERSION_STRING  - the version of F2PY found
+#   F2PY_VERSION_MAJOR   - the F2PY major version
+#   F2PY_VERSION_MINOR   - the F2PY minor version
+#   F2PY_VERSION_PATCH   - the F2PY patch version
+#
+#
+# .. note::
+#
+#   By default, the module finds the F2PY program associated with the installed NumPy package.
+#
+# Example usage
+# ^^^^^^^^^^^^^
+#
+# Assuming that a package named ``method`` is declared in ``setup.py`` and that the corresponding directory
+# containing ``__init__.py`` also exists, the following CMake code can be added to ``method/CMakeLists.txt``
+# to ensure the C sources associated with ``cylinder_methods.f90`` are generated and the corresponding module
+# is compiled:
+#
+# .. code-block:: cmake
+#
+#   find_package(F2PY REQUIRED)
+#
+#   set(f2py_module_name "_cylinder_methods")
+#   set(fortran_src_file "${CMAKE_CURRENT_SOURCE_DIR}/cylinder_methods.f90")
+#
+#   set(generated_module_file ${CMAKE_CURRENT_BINARY_DIR}/${f2py_module_name}${PYTHON_EXTENSION_MODULE_SUFFIX})
+#
+#   add_custom_target(${f2py_module_name} ALL
+#     DEPENDS ${generated_module_file}
+#     )
+#
+#   add_custom_command(
+#     OUTPUT ${generated_module_file}
+#     COMMAND ${F2PY_EXECUTABLE}
+#       -m ${f2py_module_name}
+#       -c
+#       ${fortran_src_file}
+#     WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+#     )
+#
+#   install(FILES ${generated_module_file} DESTINATION methods)
+#
+# .. warning::
+#
+#   Using ``f2py`` with ``-c`` argument means that f2py is also responsible to build the module. In that
+#   case, CMake is not used to find the compiler and configure the associated build system.
+#
+
+find_program(F2PY_EXECUTABLE NAMES f2py f2py${PYTHON_VERSION_MAJOR})
+
+if(F2PY_EXECUTABLE)
+  # extract the version string
+  execute_process(COMMAND "${F2PY_EXECUTABLE}" -v
+                  OUTPUT_VARIABLE F2PY_VERSION_STRING
+                  OUTPUT_STRIP_TRAILING_WHITESPACE)
+  if("${F2PY_VERSION_STRING}" MATCHES "^([0-9]+)(.([0-9+]))?(.([0-9+]))?$")
+    set(F2PY_VERSION_MAJOR ${CMAKE_MATCH_1})
+    set(F2PY_VERSION_MINOR "${CMAKE_MATCH_3}")
+    set(F2PY_VERSION_PATCH "${CMAKE_MATCH_5}")
+  endif()
+endif()
+
+# handle the QUIETLY and REQUIRED arguments and set F2PY_FOUND to TRUE if
+# all listed variables are TRUE
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(F2PY
+  REQUIRED_VARS F2PY_EXECUTABLE
+  VERSION_VAR F2PY_VERSION_STRING
+  )
+
+mark_as_advanced(F2PY_EXECUTABLE)