https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109183
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> --- And why would you want to preprocess it when not needed? That is the same thing. Normally the dependencies are generated when a source file is being compiled. And, that compilation happens when either the corresponding file with dependencies doesn't exist or the object file is older than at least one of its dependencies.