On Tue, 28 Sep 2021, Jakub Jelinek wrote:
> On Tue, Sep 28, 2021 at 09:49:11AM -0400, Patrick Palka via Gcc-patches wrote:
> > > --- gcc/cp/method.c.jj 2021-09-15 08:55:37.563497558 +0200
> > > +++ gcc/cp/method.c 2021-09-27 13:48:12.139271830 +0200
> > > @@ -3160,8 +3160,11 @@ defaulted_late_check (tree fn)
> > > if (kind == sfk_comparison)
> > > {
> > > /* If the function was declared constexpr, check that the
> > > definition
> > > - qualifies. Otherwise we can define the function lazily. */
> > > - if (DECL_DECLARED_CONSTEXPR_P (fn) && !DECL_INITIAL (fn))
> > > + qualifies. Otherwise we can define the function lazily.
> > > + Don't do this if the class type is still incomplete. */
> > > + if (DECL_DECLARED_CONSTEXPR_P (fn)
> > > + && !DECL_INITIAL (fn)
> > > + && COMPLETE_TYPE_P (ctx))
> > > {
> >
> > According to the function comment for defaulted_late_check, won't
> > COMPLETE_TYPE_P (ctx) always be false here?
>
> It is true in the call from the following hunk.
> The function comment at least to me doesn't imply it is always called on
> incomplete types, and defaultable_fn_check also calls it.
Ah yeah, sorry for the noise, I misunderstood the function comment.
On a related note I think 'ctx' can also be a NAMESPACE_DECL here in
the case of a defaulted non-member operator<=> (as in the below), for
which I'd expect the added COMPLETE_TYPE_P check to crash, but it looks
like in this case DECL_INITIAL is error_mark_node instead of NULL_TREE
so a crash is averted. If anyone else was wondering...
struct A {
friend constexpr bool operator==(const A&, const A&);
};
constexpr bool operator==(const A&, const A&) = default;
> >
> > > /* Prevent GC. */
> > > function_depth++;
> > > --- gcc/cp/class.c.jj 2021-09-03 09:46:28.801428380 +0200
> > > +++ gcc/cp/class.c 2021-09-27 14:07:03.465562255 +0200
> > > @@ -7467,7 +7467,14 @@ finish_struct_1 (tree t)
> > > for any static member objects of the type we're working on. */
> > > for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x))
> > > if (DECL_DECLARES_FUNCTION_P (x))
> > > - DECL_IN_AGGR_P (x) = false;
> > > + {
> > > + /* Synthetize constexpr defaulted comparisons. */
> > > + if (!DECL_ARTIFICIAL (x)
> > > + && DECL_DEFAULTED_IN_CLASS_P (x)
> > > + && special_function_p (x) == sfk_comparison)
> > > + defaulted_late_check (x);
> > > + DECL_IN_AGGR_P (x) = false;
> > > + }
> > > else if (VAR_P (x) && TREE_STATIC (x)
> > > && TREE_TYPE (x) != error_mark_node
> > > && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
>
> Jakub
>
>
