llvm-gcc-4.2/gcc/testsuite/gfortran.dg/implicit_4.f90

! { dg-do compile }
! Verify error diagnosis for invalid combinations of IMPLICIT statements
IMPLICIT NONE
IMPLICIT NONE ! { dg-error "Duplicate" }
END

SUBROUTINE a
IMPLICIT REAL(b-j) ! { dg-error "cannot follow" }
implicit none      ! { dg-error "cannot follow" }
END SUBROUTINE a

subroutine b
implicit none
implicit real(g-k) ! { dg-error "Cannot specify" }
end subroutine b

subroutine c
implicit real(a-b)
implicit integer (b-c) ! { dg-error "already" }
implicit real(d-f), complex(f-g) ! { dg-error "already" }
end subroutine c