The following code should tell us we have an out-of-bounds access at runtime:
$ cat a.f90 subroutine foo(a) integer a(*), i i = 0 a(i) = 42 end subroutine foo program test integer x(42) call foo(x) end program test $ gfortran a.f90 -fbounds-check && ./a.out -- Summary: -bounds-check doesn't check lower bound of assumed-sized array Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: accepts-invalid, diagnostic Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: fxcoudert at gcc dot gnu dot org OtherBugsDependingO 27766 nThis: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31627