Based on a report by bd satish at http://gcc.gnu.org/ml/fortran/2010-06/msg00210.html
The following program is invalid as IMPORT is missing, but gfortran still compiles it: Expected: An error such as: Error: line 12: SELF is of undefined derived type CONNECTION or error #6457: This derived type name has not been declared. [CONNECTION] module factory_pattern implicit none type, abstract :: Connection contains procedure(generic_desc), deferred :: description end type Connection abstract interface subroutine generic_desc(self) ! import class(Connection) :: self end subroutine generic_desc end interface end module factory_pattern -- Summary: [OOP] Wrongly importing a symbol into an interface without IMPORT Product: gcc Version: 4.6.0 Status: UNCONFIRMED Keywords: accepts-invalid, diagnostic Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: burnus at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44614