-coption which does nothing, but make ccache think that gccxml is not used to link some code, even if it makes no sense for gccxml. Without that option, ccache doesn’t cache gccxml and log it in “called for link” — visible with
-ooption which does the same thing than the usual
-fxml=, but in a more usual way for a compiler.
--gccxml-gcc-optionsoption, as ccache doesn’t like the commands with multiple input files. ccache reports it in its stats in the “multiple source files” section.
The results are quite interesting: