refactor: remove scikit-build classic back-compat function add_cython_target

Co-authored-by: Jean-Christophe Fillion-Robin <[email protected]>

Author: henryiii

src/cython_cmake/cmake/UseCython.cmake

@@ -57,76 +57,6 @@
 #   )
 #
 #
-# .. cmake:command:: add_cython_target
-#
-# Create a custom rule to generate the source code for a Python extension module
-# using cython.
-#
-#   add_cython_target(<Name> [<CythonInput>]
-#                     [C | CXX]
-#                     [PY2 | PY3]
-#                     [OUTPUT_VAR <OutputVar>])
-#
-# ``<Name>`` is the name of the new target, and ``<CythonInput>``
-# is the path to a cython source file.  Note that, despite the name, no new
-# targets are created by this function.  Instead, see ``OUTPUT_VAR`` for
-# retrieving the path to the generated source for subsequent targets.
-#
-# If only ``<Name>`` is provided, and it ends in the ".pyx" extension, then it
-# is assumed to be the ``<CythonInput>``.  The name of the input without the
-# extension is used as the target name.  If only ``<Name>`` is provided, and it
-# does not end in the ".pyx" extension, then the ``<CythonInput>`` is assumed to
-# be ``<Name>.pyx``.
-#
-# The Cython include search path is amended with any entries found in the
-# ``INCLUDE_DIRECTORIES`` property of the directory containing the
-# ``<CythonInput>`` file.  Use ``include_directories`` to add to the Cython
-# include search path.
-#
-# Options:
-#
-# ``C | CXX``
-#   Force the generation of either a C or C++ file.  By default, a C file is
-#   generated, unless the C language is not enabled for the project; in this
-#   case, a C++ file is generated by default.
-#
-# ``PY2 | PY3``
-#   Force compilation using either Python-2 or Python-3 syntax and code
-#   semantics.  By default, Python-2 syntax and semantics are used if the major
-#   version of Python found is 2.  Otherwise, Python-3 syntax and semantics are
-#   used.
-#
-# ``OUTPUT_VAR <OutputVar>``
-#   Set the variable ``<OutputVar>`` in the parent scope to the path to the
-#   generated source file.  By default, ``<Name>`` is used as the output
-#   variable name.
-#
-# Defined variables:
-#
-# ``<OutputVar>``
-#   The path of the generated source file.
-#
-# Cache variables that affect the behavior include:
-#
-# ``CYTHON_ANNOTATE``
-#   Whether to create an annotated .html file when compiling.
-#
-# ``CYTHON_FLAGS``
-#   Additional flags to pass to the Cython compiler.
-#
-# Usage example:
-#
-# .. code-block:: cmake
-#
-#   find_package(Cython)
-#
-#   # Note: In this case, either one of these arguments may be omitted; their
-#   # value would have been inferred from that of the other.
-#   add_cython_target(cy_code cy_code.pyx)
-#
-#   add_library(cy_code MODULE ${cy_code})
-#   target_link_libraries(cy_code ...)
-#
 #=============================================================================
 # Copyright 2011 Kitware, Inc.
 #
@@ -144,92 +74,6 @@
 #=============================================================================
 
 
-function(add_cython_target _name)
-  set(_options C CXX PY2 PY3)
-  set(_one_value OUTPUT_VAR)
-  set(_multi_value )
-
-  cmake_parse_arguments(_args
-    "${_options}"
-    "${_one_value}"
-    "${_multi_value}"
-    ${ARGN}
-    )
-
-  # Configuration options.
-  set(CYTHON_ANNOTATE OFF
-      CACHE BOOL "Create an annotated .html file when compiling *.pyx.")
-
-  set(CYTHON_FLAGS "" CACHE STRING
-      "Extra flags to the cython compiler.")
-  mark_as_advanced(CYTHON_ANNOTATE CYTHON_FLAGS)
-
-  if(_args_C)
-    set(_language "C")
-  endif()
-  if(_args_CXX)
-    set(_language "CXX")
-  endif()
-
-  if(_args_PY2)
-    set(_language_level "2")
-  endif()
-  if(_args_PY3)
-    set(_language_level "3")
-  endif()
-
-  list(GET _args_UNPARSED_ARGUMENTS 0 _arg0)
-
-  # if provided, use _arg0 as the input file path
-  if(_arg0)
-    set(_source_file ${_arg0})
-
-  # otherwise, must determine source file from name, or vice versa
-  else()
-    get_filename_component(_name_ext "${_name}" EXT)
-
-    # if extension provided, _name is the source file
-    if(_name_ext)
-      set(_source_file ${_name})
-      get_filename_component(_name "${_source_file}" NAME_WE)
-
-    # otherwise, assume the source file is ${_name}.pyx
-    else()
-      set(_source_file ${_name}.pyx)
-    endif()
-  endif()
-
-  # Set additional flags.
-  set(_cython_args)
-  if(CYTHON_ANNOTATE)
-    list(APPEND _cython_args "--annotate")
-  endif()
-  if(CMAKE_BUILD_TYPE STREQUAL "Debug" OR
-      CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
-    list(APPEND _cython_args
-      "--gdb"
-      "--line-directives"
-    )
-  endif()
-  string(STRIP "${CYTHON_FLAGS}" _stripped_cython_flags)
-  if(_stripped_cython_flags)
-    string(REGEX REPLACE " " ";" CYTHON_FLAGS_LIST "${_stripped_cython_flags}")
-    list(APPEND _cython_args ${CYTHON_FLAGS_LIST})
-  endif()
-
-  Cython_compile_pyx(
-    LANGUAGE ${_language}
-    LANGUAGE_LEVEL ${_language_level}
-    CYTHON_ARGS ${_cython_args}
-    OUTPUT_VARIABLE ${_args_OUTPUT_VAR}
-    ${_source_file}
-    )
-
-  if(_args_OUTPUT_VAR)
-    set(${_args_OUTPUT_VAR} ${${_args_OUTPUT_VAR}} PARENT_SCOPE)
-  endif()
-endfunction()
-
 function(Cython_compile_pyx)
   set(_options )
   set(_one_value LANGUAGE_LEVEL LANGUAGE OUTPUT_VARIABLE)