[Bug fortran/53320] New: -fcheck=pointer should diagnose pointer-assignment of a noncontiguous tgt to a CONTIGUOUS ptr

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53320

             Bug #: 53320
           Summary: -fcheck=pointer should diagnose pointer-assignment of
                    a noncontiguous tgt to a CONTIGUOUS ptr
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org
        Depends on: 45424


Related to PR 49232 (compile-time check) and PR 45424 (is_contiguous intrinsic,
of interest is the trans-intrinsic.c part).

For:
  integer, pointer, CONTIGUOUS :: ptr
  ptr => target

-fcheck=pointer should check whether the RHS is contiguous.

The standard demands: "If the pointer object has the CONTIGUOUS attribute, the
pointer target shall be contiguous." (Cf. "7.2.2.3 Data pointer assignment" in
the Fortran 2008 standard.) But that's not a constraint and thus needs to be
checked at run time.