CMake hacks to create a Bundle for macOS

CMakeLists.txt

if (BUILD_APPLE_BUNDLE)
    set(EXEC_NAME "MyUI")
else ()
    get_filename_component(EXEC_NAME "${CMAKE_CURRENT_SOURCE_DIR}" NAME)
    string(APPEND EXEC_NAME "-${PROJECT_VERSION}")
endif ()

set(Source_Files "main.c")
source_group("Source Files" FILES "${Source_Files}")

add_executable("${EXEC_NAME}" "${Source_Files}")

if (MSVC)
  set_property(TARGET "${EXEC_NAME}" APPEND_STRING PROPERTY LINK_FLAGS " /NODEFAULTLIB:MSVCRTD")
endif (MSVC)

target_link_libraries(
        "${EXEC_NAME}"
        PRIVATE
        "${PROJECT_NAME}_compiler_flags"
        "${PROJECT_NAME}_lib"
)

set_target_properties(
        "${EXEC_NAME}"
        PROPERTIES
        LINKER_LANGUAGE
        C
)

# install rules
include(GNUInstallDirs)

set(RESOURCE_FILES "")
foreach (_dir "icons" "images")
    file(GLOB ls LIST_DIRECTORIES false "${CMAKE_SOURCE_DIR}/${PROJECT_NAME}/${_dir}/*")
    if (BUILD_APPLE_BUNDLE)
        foreach (filename ${ls})
            list(APPEND RESOURCE_FILES "${filename}")
            set_source_files_properties("${filename}" PROPERTIES MACOSX_PACKAGE_LOCATION "Resources")
        endforeach (filename ${ls})
        # For debugging before `cmake --install` | `cpack`
        file(COPY "${CMAKE_SOURCE_DIR}/${PROJECT_NAME}/${_dir}"
             DESTINATION "${CMAKE_BINARY_DIR}/${EXEC_NAME}.app/Contents/Resources")
        # For `cmake --install` | `cpack`
        install(DIRECTORY "${CMAKE_SOURCE_DIR}/${PROJECT_NAME}/${_dir}"
                DESTINATION "${EXEC_NAME}.app")
    else ()
        # For debugging before `cmake --install` | `cpack`
        file(COPY "${CMAKE_SOURCE_DIR}/${PROJECT_NAME}/${_dir}"
                DESTINATION "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}")
        # For `cmake --install` | `cpack`
        install(DIRECTORY "${CMAKE_SOURCE_DIR}/${PROJECT_NAME}/${_dir}"
                DESTINATION "${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}/${_dir}")
    endif (BUILD_APPLE_BUNDLE)
endforeach (_dir "icons" "images")

if (BUILD_APPLE_BUNDLE)
    target_compile_options("${EXEC_NAME}" PRIVATE -fPIC -Wpartial-availability -Wno-inconsistent-missing-override -rdynamic)
    set_property(TARGET "${EXEC_NAME}" APPEND_STRING PROPERTY LINK_FLAGS "-fPIC -rdynamic")

    list(APPEND RESOURCE_FILES "${BUNDLE_ICON}")
    # set_target_properties("${EXEC_NAME}" PROPERTIES MACOSX_BUNDLE_ICON_FILE "${BUNDLE_ICON}")
    file(COPY "${BUNDLE_ICON}" #${RESOURCE_FILES}
         DESTINATION "${CMAKE_BINARY_DIR}/${EXEC_NAME}.app/Contents/Resources")
    install(DIRECTORY "${CMAKE_SOURCE_DIR}/${PROJECT_NAME}/${_dir}"
            DESTINATION "${EXEC_NAME}.app")
    set_source_files_properties("${BUNDLE_ICON}" PROPERTIES MACOSX_PACKAGE_LOCATION "Resources")
    foreach (res ${RESOURCE_FILES})
        set_source_files_properties("${res}" PROPERTIES MACOSX_PACKAGE_LOCATION "Resources")
    endforeach (res ${RESOURCE_FILES})
    target_sources("${EXEC_NAME}" PRIVATE ${MAC_RESOURCE_FILES})

    set_target_properties(
            "${EXEC_NAME}"
            PROPERTIES
            MACOSX_BUNDLE_NAME                             "${EXEC_NAME}"
            MACOSX_BUNDLE_VERSION                          "${PROJECT_VERSION}"
            MACOSX_BUNDLE_GUI_IDENTIFIER                   "org.${EXEC_NAME}.gui"
            MACOSX_BUNDLE_ICON_FILE                        "Icon.icns"
            MACOSX_BUNDLE_INFO_PLIST                       "${CMAKE_SOURCE_DIR}/cmake/Info.plist.in"
            MACOSX_BUNDLE                                  "TRUE"
            # MACHO_COMPATIBILITY_VERSION                  "12.0.0"
            RESOURCE                                       "${RESOURCE_FILES}"
            XCODE_ATTRIBUTE_CODE_SIGN_IDENTITY             ""
            XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED          NO
            XCODE_ATTRIBUTE_DEBUG_INFORMATION_FORMAT       dwarf
            XCODE_ATTRIBUTE_GCC_INLINES_ARE_PRIVATE_EXTERN YES
            XCODE_ATTRIBUTE_CLANG_LINK_OBJC_RUNTIME        NO
    )


#    install(TARGETS "${EXEC_NAME}"# "${PROJECT_NAME}_lib"
#            # TYPE "RUNTIME"
#            RUNTIME DESTINATION "${EXEC_NAME}.app"
#            LIBRARY DESTINATION "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}"
#            ARCHIVE DESTINATION "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}"
#            BUNDLE DESTINATION  "${EXEC_NAME}.app"
#            COMPONENT           "${PROJECT_NAME}")
    install(DIRECTORY "${CMAKE_BINARY_DIR}/${EXEC_NAME}.app" DESTINATION .)

#    install(CODE "include(BundleUtilities)"
#                 "fixup_bundle(\"${EXEC_NAME}\"   \"\"   \"${RESOURCE_FILES}\")"
#                 "include(CopyDependencies)"
#                 "copy_dependencies(\"\${EXEC_NAME}\")"
#            COMPONENT "Runtime")

add_custom_command(
        TARGET "${EXEC_NAME}" POST_BUILD
        COMMAND install_name_tool
                -rpath "${CMAKE_BINARY_DIR}/${EXEC_NAME}.app/Contents/PlugIns" '@executable_path/../PlugIns'
                "${CMAKE_BINARY_DIR}/${EXEC_NAME}.app/Contents/MacOS/${EXEC_NAME}"
        WORKING_DIRECTORY "${CMAKE_BINARY_DIR}"
        COMMENT "Replace library search path from absolute to relative"
)
else ()
    install(TARGETS "${EXEC_NAME}" "${PROJECT_NAME}_lib"
            # TYPE "RUNTIME"
            RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}"
            LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}"
            ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}/static"
            BUNDLE DESTINATION  "${CMAKE_INSTALL_BINDIR}/${EXEC_NAME}.app"
            COMPONENT           "${PROJECT_NAME}")
endif (BUILD_APPLE_BUNDLE)

Info.plist.in

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist>
  <dict>
    <key>CFBundleExecutable</key>
    <string>myui</string>
    <key>CFBundleIconFile</key>
    <string>@MACOSX_BUNDLE_ICON_FILE@</string>
    <key>CFBundleIdentifier</key>
    <string>org.my-ui.gui</string>
    <key>CFBundleName</key>
    <string>my-ui</string>
    <key>CFBundleDisplayName</key>
    <string>Archimedes</string>
    <key>CFBundlePackageType</key>
    <string>APPL</string>
    <key>CFBundleSignature</key>
    <string>????</string>
    <key>CFBundleShortVersionString</key>
    <string>@GUI_VERSION@</string>
    <key>CFBundleVersion</key>
    <string>@GUI_VERSION@</string>
    <key>NSHumanReadableCopyright</key>
    <string>Open MyUI</string>
    <key>NSHighResolutionCapable</key>
    <true/>
  </dict>
</plist>