[Bug libgomp/92840] New: [OpenACC] Disallow 'acc_unmap_data' for everything other than 'acc_map_data'

[tschwinge at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92840

            Bug ID: 92840
           Summary: [OpenACC] Disallow 'acc_unmap_data' for everything
                    other than 'acc_map_data'
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: openacc, patch
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tschwinge at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org, jules at gcc dot gnu.org
  Target Milestone: ---

OpenACC 2.6, 3.2.27. "acc_unmap_data" states that "It is undefined behavior to
call 'acc_unmap_data' with a host address unless that host address was mapped
to device memory using 'acc_map_data'.  We're currently not checking that, but
it's easy enough to do (..., and uncovers some weirdness...).

WIP patch exists.