On Tue, Apr 30, 2024 at 1:50 PM Jason Merrill <ja...@redhat.com> wrote:
>
> On 3/15/24 01:15, Ken Matsui wrote:
> > Added diagnostics for build_invoke.
> >
> > Ok for 15?
>
> Thanks, just a few tweaks needed. Will you have time to make them? Or
> Patrick?
I believe I will have time later next week. Thank you so much for your review!
>
> [...]
> > diff --git a/gcc/cp/method.cc b/gcc/cp/method.cc
> > index 98c10e6a8b5..2282ce71c06 100644
> > --- a/gcc/cp/method.cc
> > +++ b/gcc/cp/method.cc
> > @@ -1928,6 +1928,162 @@ build_trait_object (tree type)
> > return build_stub_object (type);
> > }
> >
> > +/* [func.require] Build an expression of INVOKE(FN_TYPE, ARG_TYPES...).
> > If the
> > + given is not invocable, returns error_mark_node. */
> > +
> > +tree
> > +build_invoke (tree fn_type, const_tree arg_types, tsubst_flags_t complain)
> > +{
> > + if (error_operand_p (fn_type) || error_operand_p (arg_types))
> > + return error_mark_node;
> > +
> > + gcc_assert (TYPE_P (fn_type));
> > + gcc_assert (TREE_CODE (arg_types) == TREE_VEC);
> > +
> > + /* Access check is required to determine if the given is invocable. */
> > + deferring_access_check_sentinel acs (dk_no_deferred);
> > +
> > + /* INVOKE is an unevaluated context. */
> > + cp_unevaluated cp_uneval_guard;
> > +
> > + bool is_ptrdatamem;
> > + bool is_ptrmemfunc;
> > + if (TREE_CODE (fn_type) == REFERENCE_TYPE)
> > + {
> > + tree deref_fn_type = TREE_TYPE (fn_type);
> > + is_ptrdatamem = TYPE_PTRDATAMEM_P (deref_fn_type);
> > + is_ptrmemfunc = TYPE_PTRMEMFUNC_P (deref_fn_type);
> > +
> > + /* Dereference fn_type if it is a pointer to member. */
> > + if (is_ptrdatamem || is_ptrmemfunc)
> > + fn_type = deref_fn_type;
> > + }
> > + else
> > + {
> > + is_ptrdatamem = TYPE_PTRDATAMEM_P (fn_type);
> > + is_ptrmemfunc = TYPE_PTRMEMFUNC_P (fn_type);
> > + }
> > +
> > + if (is_ptrdatamem && TREE_VEC_LENGTH (arg_types) != 1)
> > + {
> > + if (complain & tf_error)
> > + error ("pointer to data member type %qT can only be invoked with "
> > + "one argument", fn_type);
> > + return error_mark_node;
> > + }
> > +
> > + if (is_ptrmemfunc && TREE_VEC_LENGTH (arg_types) == 0)
> > + {
> > + if (complain & tf_error)
> > + error ("pointer to member function type %qT must be invoked with "
> > + "at least one argument", fn_type);
> > + return error_mark_node;
> > + }
> > +
> > + /* Construct an expression of a pointer to member. */
> > + tree ptrmem_expr;
> > + if (is_ptrdatamem || is_ptrmemfunc)
> > + {
> > + tree datum_type = TREE_VEC_ELT (arg_types, 0);
> > +
> > + /* datum must be a class type or a reference/pointer to a class
> > type. */
> > + if (TYPE_REF_P (datum_type) || POINTER_TYPE_P (datum_type))
> > + {
> > + if (!CLASS_TYPE_P (TREE_TYPE (datum_type)))
> > + {
> > + if (complain & tf_error)
> > + error ("datum type %qT of a pointer to member must be a class"
>
> I don't see the term "datum" anywhere in [func.require], let's refer to
> the "first argument" instead.
>
> > + "type or a reference/pointer to a class type",
> > + datum_type);
> > + return error_mark_node;
> > + }
> > + }
> > + else if (!CLASS_TYPE_P (datum_type))
> > + {
> > + if (complain & tf_error)
> > + error ("datum type %qT of a pointer to member must be a class"
> > + "type or a reference/pointer to a class type",
> > + datum_type);
> > + return error_mark_node;
> > + }
> > +
> > + bool is_refwrap = false;
> > + if (CLASS_TYPE_P (datum_type))
> > + {
> > + /* 1.2 & 1.5: Handle std::reference_wrapper. */
> > + tree datum_decl = TYPE_NAME (TYPE_MAIN_VARIANT (datum_type));
> > + if (decl_in_std_namespace_p (datum_decl))
> > + {
> > + const_tree name = DECL_NAME (datum_decl);
> > + if (name && (id_equal (name, "reference_wrapper")))
> > + {
> > + /* Retrieve T from std::reference_wrapper<T>,
> > + i.e., decltype(datum.get()). */
> > + datum_type = TREE_VEC_ELT (TYPE_TI_ARGS (datum_type), 0);
> > + is_refwrap = true;
> > + }
> > + }
> > + }
> > +
> > + tree datum_expr = build_trait_object (datum_type);
> > + tree fn_expr = build_trait_object (fn_type);
> > + ptrmem_expr = build_m_component_ref (datum_expr, fn_expr, complain);
>
> We should check same-or-base before trying this, not after.
>
> > + if (error_operand_p (ptrmem_expr) && !is_refwrap)
> > + {
> > + tree ptrmem_class_type = TYPE_PTRMEM_CLASS_TYPE (fn_type);
> > + const bool ptrmem_is_base_of_datum =
> > + (NON_UNION_CLASS_TYPE_P (ptrmem_class_type)
> > + && NON_UNION_CLASS_TYPE_P (datum_type)
> > + && (same_type_ignoring_top_level_qualifiers_p (ptrmem_class_type,
> > + datum_type)
> > + || DERIVED_FROM_P (ptrmem_class_type, datum_type)));
> > +
> > + if (!ptrmem_is_base_of_datum)
> > + {
> > + /* 1.3 & 1.6: Try to dereference datum_expr. */
> > + datum_expr = build_x_indirect_ref (UNKNOWN_LOCATION, datum_expr,
> > + RO_UNARY_STAR, NULL_TREE,
> > + complain);
> > + /* Rebuild ptrmem_expr. */
> > + ptrmem_expr = build_m_component_ref (datum_expr, fn_expr,
> > + complain);
> > + }
> > + }
> > + /* 1.1 & 1.4: Otherwise. */
> > +
> > + if (error_operand_p (ptrmem_expr))
> > + {
> > + if (complain & tf_error)
> > + error ("cannot form an INVOKE expression of a pointer to member");
>
> if (complain & tf_eror), we should have already given an error, this one
> seems redundant.
>
> Jason
>
> > + return error_mark_node;
> > + }
>
