myx-cmake/MyxCMake/functions/MyxCMakeDocBreathe.cmake

function(myx_cmake_doc_breathe)
  set(BREATHE_FOUND AUTO CACHE STRING "Enable Breathe documentation generator")
  set_property(CACHE BREATHE_FOUND PROPERTY STRINGS ON OFF AUTO)

  find_package(Doxygen)
  find_package(Perl)
  set(Python_ADDITIONAL_VERSIONS 3.11;3.10;3.9;3.8;3.7;3.6;3.5;3.4;3.3;3.2)
  find_package(PythonInterp)
  if(PYTHONINTERP_FOUND)
    find_package(Sphinx)
    include(FindPythonModule)
    find_python_module(breathe)
    find_python_module(recommonmark)
    if(DOXYGEN_FOUND
       AND PERL_FOUND
       AND PYTHONINTERP_FOUND
       AND SPHINX_EXECUTABLE
       AND breathe
       AND recommonmark)
      set(BREATHE_FOUND ON CACHE STRING "Breathe documentation generator enabled" FORCE)
    else()
      set(BREATHE_FOUND OFF CACHE STRING "Breathe documentation generator disabled" FORCE)
    endif()
  else()
    set(BREATHE_FOUND OFF CACHE STRING "Breathe documentation generator disabled" FORCE)
  endif()

  set(_target "myx-cmake-doc-breathe-${CMAKE_PROJECT_NAME}")
  if(NOT BREATHE_FOUND)
    message(STATUS "MyxCMake:")
    add_custom_target(${_target} VERBATIM COMMENT "  Breathe is not found. Skipping target ${_target} build")
    return()
  endif()

  if(NOT TARGET ${_target})
    set(options)
    set(oneValueArgs COMMENT)
    set(multiValueArgs)
    cmake_parse_arguments(_arg "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})

    set(BREATHE_DIR ${CMAKE_BINARY_DIR}/doc/breathe)
    set(BREATHE_CONF_DIR    ${BREATHE_DIR}/conf)
    set(BREATHE_DOXYGEN_DIR ${BREATHE_DIR}/doxygen)
    set(GENERATE_XML YES)
    set(GENERATE_HTML NO)
    set(GENERATE_LATEX NO)
    set(CONF_FILE ${MYX_CMAKE_FUNCTIONS_DIR}/doc/breathe-conf.py.in)
    set(DOXY_FILE ${MYX_CMAKE_FUNCTIONS_DIR}/doc/Doxyfile.in)

    configure_file(${CONF_FILE} ${BREATHE_CONF_DIR}/conf.py @ONLY)
    configure_file(${DOXY_FILE} ${BREATHE_DOXYGEN_DIR}/Doxyfile @ONLY)

    add_custom_target(${_target}
      VERBATIM
      DEPENDS ${DOXY_FILE}
      DEPENDS ${CONF_FILE}
      COMMAND "${CMAKE_COMMAND}" -E make_directory ${BREATHE_CONF_DIR}
      COMMAND ${SPHINX_EXECUTABLE} -q -b html -c ${BREATHE_CONF_DIR}
      -d ${BREATHE_DIR}/cache ${BREATHE_DOXYGEN_DIR} ${BREATHE_DIR}/html
      COMMENT "Building ${CMAKE_PROJECT_NAME} documentation with Breathe")

    set(INDEX_MD_FILE ${CMAKE_HOME_DIRECTORY}/doc/breathe/index.md.in)
    if(EXISTS ${INDEX_MD_FILE})
      configure_file(${INDEX_MD_FILE} ${BREATHE_DOXYGEN_DIR}/index.md @ONLY)
      file(GLOB MD_FILES ${CMAKE_HOME_DIRECTORY}/doc/breathe/*.md)
      if(MD_FILES)
        add_custom_command(TARGET ${_target} PRE_BUILD COMMAND ${CMAKE_COMMAND} -E copy_if_different
          ${MD_FILES} ${BREATHE_DOXYGEN_DIR})
      endif()
    endif()

    set(INDEX_RST_FILE ${CMAKE_HOME_DIRECTORY}/doc/breathe/index.rst.in)
    if(EXISTS ${INDEX_RST_FILE})
      configure_file(${INDEX_RST_FILE} ${BREATHE_DOXYGEN_DIR}/index.rst @ONLY)
      file(GLOB RST_FILES ${CMAKE_SOURCE_DIR}/doc/breathe/*.rst)
      if(RST_FILES)
        add_custom_command(TARGET ${target} PRE_BUILD COMMAND ${CMAKE_COMMAND} -E copy_if_different
          ${RST_FILES} ${BREATHE_DOXYGEN_DIR})
      endif()
    endif()

    if(NOT TARGET myx-cmake-doc-breathe)
      add_custom_target(myx-cmake-doc-breathe)
    endif()
    add_dependencies(myx-cmake-doc-breathe ${_target})

    install(DIRECTORY ${CMAKE_BINARY_DIR}/doc/breathe/html
            COMPONENT doc OPTIONAL
            DESTINATION ${CMAKE_INSTALL_DATADIR}/doc/breathe)
  else()
    message(STATUS "MyxCMake:")
    add_custom_target(${target} VERBATIM COMMENT "  Breathe is not found. Skipping target ${target} build")
  endif()
endfunction()