https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85777
--- Comment #7 from Eric Gallager <egallager at gcc dot gnu.org> --- (In reply to Vincent Lefèvre from comment #6) > But this cannot apply to projects that use GNU Automake, which does not > generate such rules. And with Automake, things are more complex in practice, > because in the rules, there are additional options for dependency tracking. you can still add handwritten rules in Automake Makefiles to be used alongside the Automake-generated rules.