Support for CFLAGS_FOR_TARGET has disappeared in the GNAT run-time libraries but I don't know when. For sure, it is gone in the 4.4.x series.
This is used by the recommended RTEMS GNAT build procedure. -- Summary: GNAT run-time missing CFLAGS_FOR_TARGET Product: gcc Version: 4.4.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: ada AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: joel at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41096