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# This CMakeLists.txt allows source distributions of the gmxapi Python package
# to rely on scikit-build for support of various Python packaging systems. The
# simplest use case is to allow the `setup.py` file to invoke skbuild to
# configure and run CMake. CMake could be invoked directly by the user or a
# parent package, but the Python distribution would not be packaged automatically.
# Reference https://redmine.gromacs.org/issues/2896 for additional discussion.
cmake_minimum_required(VERSION 3.9.6)

# This needs to be set before project() in order to pick up toolchain files
#list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../../cmake)

# OS X deployment target should be >=10.9 for modern C++ compatibility.
# Reference https://scikit-build.readthedocs.io/en/latest/generators.html#macosx
# and https://github.com/MacPython/wiki/wiki/Spinning-wheels
set(CMAKE_OSX_DEPLOYMENT_TARGET 10.9 CACHE STRING
    "OS X deployment target below 10.9 does not use modern standard library"
    FORCE)
set(CMAKE_OSX_ARCHITECTURES x86_64 CACHE STRING
    "OS X should build Python package for 64-bit architecture"
    FORCE)

project(gmxapi VERSION 0.1.0)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# Only interpret if() arguments as variables or keywords when unquoted.
cmake_policy(SET CMP0054 NEW)
# honor the language standard settings for try_compile()
cmake_policy(SET CMP0067 NEW)

# TODO: Account for externally-provided pybind headers where recommended by packaging system.
# Reference https://redmine.gromacs.org/issues/2896
add_subdirectory(external/pybind)

set(GMXAPI_PYTHON_EXTENSION_SOURCES
    gmxapi/module.cpp
    )

pybind11_add_module(_gmxapi
                    ${GMXAPI_PYTHON_EXTENSION_SOURCES}
                    )

target_include_directories(_gmxapi PRIVATE
                           ${CMAKE_CURRENT_SOURCE_DIR}/gmxapi
                           ${CMAKE_CURRENT_BINARY_DIR}/gmxapi
                           )

install(TARGETS _gmxapi LIBRARY DESTINATION gmxapi)

if(NOT SKBUILD)
    # TODO: Determine packaging and installation cases and implementation.
    # Reference https://redmine.gromacs.org/issues/2896 for additional discussion.
    message(WARNING "CMake should be run by scikit-build through setup.py for proper Python packaging.")
    # Try to do something sensible. Collect Python sources as setup.py would.
    file(GLOB_RECURSE _py_sources CONFIGURE_DEPENDS $CMAKE_CURRENT_SOURCE_DIR/gmxapi/*.py)
    install(FILES ${_py_sources} DESTINATION gmxapi)
endif()