CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

project(numbuf)

list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/Modules)

# Make libnumbuf.so look for shared libraries in the folder libnumbuf.so is in.
set(CMAKE_INSTALL_RPATH "$ORIGIN/")
set(CMAKE_MACOSX_RPATH 1)

message(STATUS "Trying custom approach for finding Python.")
# Start off by figuring out which Python executable to use.
find_program(CUSTOM_PYTHON_EXECUTABLE python)
message(STATUS "Found Python program: ${CUSTOM_PYTHON_EXECUTABLE}")
execute_process(COMMAND ${CUSTOM_PYTHON_EXECUTABLE} -c "import sys; print('python' + sys.version[0:3])"
                OUTPUT_VARIABLE PYTHON_LIBRARY_NAME OUTPUT_STRIP_TRAILING_WHITESPACE)
message(STATUS "PYTHON_LIBRARY_NAME: " ${PYTHON_LIBRARY_NAME})
# Now find the Python include directories.
execute_process(COMMAND ${CUSTOM_PYTHON_EXECUTABLE} -c "from distutils.sysconfig import *; print(get_python_inc())"
                OUTPUT_VARIABLE PYTHON_INCLUDE_DIRS OUTPUT_STRIP_TRAILING_WHITESPACE)
message(STATUS "PYTHON_INCLUDE_DIRS: " ${PYTHON_INCLUDE_DIRS})
# Now find the Python libraries. We'll start by looking near the Python
# executable. If that fails, then we'll look near the Python include
# directories.
execute_process(COMMAND ${CUSTOM_PYTHON_EXECUTABLE} -c "import sys; print(sys.exec_prefix)"
                OUTPUT_VARIABLE PYTHON_PREFIX OUTPUT_STRIP_TRAILING_WHITESPACE)
message(STATUS "PYTHON_PREFIX: " ${PYTHON_PREFIX})
FIND_LIBRARY(PYTHON_LIBRARIES
             NAMES ${PYTHON_LIBRARY_NAME}
             HINTS "${PYTHON_PREFIX}"
             PATH_SUFFIXES "lib" "libs"
             NO_DEFAULT_PATH)
message(STATUS "PYTHON_LIBRARIES: " ${PYTHON_LIBRARIES})
# If that failed, perhaps because the user is in a virtualenv, search around
# the Python include directories.
if(NOT PYTHON_LIBRARIES)
  message(STATUS "Failed to find PYTHON_LIBRARIES near the Python executable, so now looking near the Python include directories.")
  FIND_LIBRARY(PYTHON_LIBRARIES
               NAMES ${PYTHON_LIBRARY_NAME}
               HINTS "${PYTHON_INCLUDE_DIRS}/../.."
               PATH_SUFFIXES "lib" "libs"
               NO_DEFAULT_PATH)
  message(STATUS "PYTHON_LIBRARIES: " ${PYTHON_LIBRARIES})
endif()
# If we found the Python libraries and the include directories, then continue
# on. If not, then try find_package as a last resort, but it probably won't
# work.
if(PYTHON_LIBRARIES AND PYTHON_INCLUDE_DIRS)
  message(STATUS "The custom approach for finding Python succeeded.")
  SET(PYTHONLIBS_FOUND TRUE)
else()
  message(WARNING "The custom approach for finding Python failed. Defaulting to find_package.")
  find_package(PythonInterp REQUIRED)
  find_package(PythonLibs ${PYTHON_VERSION_STRING} EXACT REQUIRED)
  set(CUSTOM_PYTHON_EXECUTABLE ${PYTHON_EXECUTABLE})
endif()