at least seen on the redhat/gcc-4_1-branch-java-merge-20070117 branch; not yet validated on the trunk:
$ touch IIFoo.java $ gcj -C IIFoo.java gcj: no input files -- Summary: [regression] gcj driver doesn't recognize files starting with II Product: gcc Version: unknown Status: UNCONFIRMED Severity: major Priority: P3 Component: driver AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: doko at ubuntu dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30714