Add generator expressions for macOS bundle targets
TARGET_FILE
currently for macOS bundles goes to the /Contents/MacOS/XXX file, and TARGET_FILE_DIR
goes to the /Contents/MacOS/ directory. It would be nice if there were generator expressions that mapped to the bundle and bundle parent directory, for example TARGET_BUNDLE
and TARGET_BUNDLE_DIR
. Currently we have to use relative paths, like $<TARGET_FILE_DIR:${TARGET}>/../../
which is more difficult to read.