[Bug fortran/28006] New: Negative-sized array should be empty array, not try to allocate negative memory

[tobias dot burnus at physik dot fu-berlin dot de]

Based on
http://groups.google.com/group/comp.lang.fortran/browse_frm/thread/c46c14d9d8879bad/14517cbe22d222bc#14517cbe22d222bc

If one uses an array with a upper bound lower than the lower bound, the array
contains zero items. However, gfortran tries to allocate negative MEMORY when
one uses this.

Example:
-----
program xint_func
  print *, 'intfunc', -1, int_func(-3)
contains
  function int_func(n) result(ivec)
    integer, intent(in) :: n
    integer             :: ivec(n)
    integer             :: i
    forall (i=1:n) ivec(i) = i
  end function int_func
end program xint_func
-----
This produces in gfortran:
 Fortran runtime error: Attempt to allocate a negative amount of memory.
 intfunc          -1

Tested with 4.2.0 20060612 (experimental) and 4.1.0 (SUSE Linux).


-- 
           Summary: Negative-sized array should be empty array, not try to
                    allocate negative memory
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tobias dot burnus at physik dot fu-berlin dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28006