python_extension_module: Add support for module suffix

skbuild/resources/cmake/FindPythonExtensions.cmake

@@ -32,7 +32,8 @@
#
#   python_extension_module(<Target>
#                           [LINKED_MODULES_VAR <LinkedModVar>]
#                           [FORWARD_DECL_MODULES_VAR <ForwardDeclModVar>])
#                           [FORWARD_DECL_MODULES_VAR <ForwardDeclModVar>]
#                           [MODULE_SUFFIX <ModuleSuffix>])
#
# Only extension modules that are configured to be built as MODULE libraries can
# be runtime-loaded through the standard Python import mechanism.  All other
@@ -62,6 +63,15 @@
#   that use them.  By default, the global property
#   ``PY_FORWARD_DECL_MODULES_LIST`` is used.
#
# ``MODULE_SUFFIX <ModuleSuffix>``
#   Suffix appended to the python extension module file.
#   The default suffix is retrieved using ``sysconfig.get_config_var("SO")"``,
#   if not available, the default is then ``.so`` on unix and ``.pyd`` on
#   windows.
#   Setting the variable ``PYTHON_EXTENSION_MODULE_SUFFIX`` in the caller
#   scope defines the value used for all extensions not having a suffix
#   explicitly specified using ``MODULE_SUFFIX`` parameter.
#
#
# .. cmake:command:: python_standalone_executable
#
@@ -237,6 +247,7 @@ import os
import os.path
import site
import sys
import sysconfig

result = None
rel_result = None
@@ -270,6 +281,7 @@ sys.stdout.write(\";\".join((
    sys.prefix,
    result,
    rel_result,
    sysconfig.get_config_var('SO')
)))
")

@@ -297,8 +309,13 @@ list(GET _list 4 _item)
set(PYTHON_RELATIVE_SITE_PACKAGES_DIR "${_item}")
mark_as_advanced(PYTHON_RELATIVE_SITE_PACKAGES_DIR)

if(NOT DEFINED PYTHON_EXTENSION_MODULE_SUFFIX)
  list(GET _list 5 _item)
  set(PYTHON_EXTENSION_MODULE_SUFFIX "${_item}")
endif()

function(python_extension_module _target)
  set(one_ops LINKED_MODULES_VAR FORWARD_DECL_MODULES_VAR)
  set(one_ops LINKED_MODULES_VAR FORWARD_DECL_MODULES_VAR MODULE_SUFFIX)
  cmake_parse_arguments(_args "" "${one_ops}" "" ${ARGN})

  set(_lib_type "NA")
@@ -356,8 +373,20 @@ function(python_extension_module _target)
  endif()

  if(_is_module_lib OR _is_shared_lib)
    if(_is_module_lib AND WIN32 AND NOT CYGWIN)
      set_target_properties(${_target} PROPERTIES SUFFIX ".pyd")
    if(_is_module_lib)

      if(NOT _args_MODULE_SUFFIX)
        set(_args_MODULE_SUFFIX "${PYTHON_EXTENSION_MODULE_SUFFIX}")
      endif()

      if(_args_MODULE_SUFFIX STREQUAL "" AND WIN32 AND NOT CYGWIN)
        set(_args_MODULE_SUFFIX ".pyd")
      endif()

      if(NOT _args_MODULE_SUFFIX STREQUAL "")
        set_target_properties(${_target}
          PROPERTIES SUFFIX ${_args_MODULE_SUFFIX})
      endif()
    endif()

    target_link_libraries_with_dynamic_lookup(${_target} ${PYTHON_LIBRARIES})