On Tue, May 09, 2023 at 08:24:16PM +0200, Harald Anlauf wrote:
> Hi Paul,
>
> On 5/9/23 17:51, Paul Richard Thomas via Gcc-patches wrote:
> > Hi All,
> >
> > Thanks to Steve Kargl for the fix. It caused finalize_8.f03 to fail because
> > this testcase checked that finalizable derived types could not be specified
> > in a submodule. I have replaced the original test with a test of the patch.
> >
> > Thanks also to Malcolm Cohen for guidance on this.
> >
> > OK for trunk?
>
> the patch looks good to me. However:
>
> @@ -11637,8 +11637,9 @@ gfc_match_final_decl (void)
> block = gfc_state_stack->previous->sym;
^^^^^^^^^^^^^^^^^^^^^^^^^
See below.
> gcc_assert (block);
>
> - if (!gfc_state_stack->previous || !gfc_state_stack->previous->previous
> - || gfc_state_stack->previous->previous->state != COMP_MODULE)
> + if (gfc_state_stack->previous->previous
> + && gfc_state_stack->previous->previous->state != COMP_MODULE
> + && gfc_state_stack->previous->previous->state != COMP_SUBMODULE)
> {
> gfc_error ("Derived type declaration with FINAL at %C must be in
> the"
> " specification part of a MODULE");
>
> I am wondering if we should keep the protection against a potential
> NULL pointer dereference (i.e. gfc_state_stack->previous == NULL) for
> possibly invalid code. I have failed to produce a simple testcase,
> but others may have "better" ideas.
It's not needed. See above. gfc_state_stack->previous is referenced
a few lines above the if-stmt. The reference will segfault if the
pointer is NULL.
--
Steve
