I ran the gfortran testsuite with -fbounds-check and found a few failures (on i686-linux), among which was gfortran.dg/aliasing_dummy_1.f90. Here is a reduced testcase:
program test_lex type :: dtype character*5 :: word end type dtype type :: list type(dtype) :: list(1) end type list type(list) :: table call foo1 (table%list(1)%word) contains subroutine foo1 (slist) character(*), dimension(*) :: slist write (slist(1), '(i5)') 0 end subroutine foo1 end program test_lex $ gfortran -fbounds-check bug.f90 && ./a.out Fortran runtime error: Array reference out of bounds -- Summary: -fbounds-check gives undue warning with Product: gcc Version: 4.2.0 Status: UNCONFIRMED Keywords: wrong-code Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: fxcoudert at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27765