On Fri, May 27, 2022 at 11:52:12AM -0400, Jason Merrill wrote:
> On 5/26/22 20:33, Marek Polacek wrote:
> > As discussed here:
> > <https://gcc.gnu.org/pipermail/gcc-patches/2021-February/564629.html>,
> > type_dependent_expression_p should not be called with a type argument.
> >
> > I promised I'd add an assert so here it is. One place needed adjusting,
> > the comment explains why.
> >
> > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
> >
> > PR c++/99080
> >
> > gcc/cp/ChangeLog:
> >
> > * pt.cc (type_dependent_expression_p): Assert !TYPE_P.
> > * semantics.cc (finish_id_expression_1): Don't call
> > type_dependent_expression_p for a type.
> > ---
> > gcc/cp/pt.cc | 2 ++
> > gcc/cp/semantics.cc | 4 +++-
> > 2 files changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> > index 24bbe2f4060..89156cb88b4 100644
> > --- a/gcc/cp/pt.cc
> > +++ b/gcc/cp/pt.cc
> > @@ -27727,6 +27727,8 @@ type_dependent_expression_p (tree expression)
> > if (expression == NULL_TREE || expression == error_mark_node)
> > return false;
> > + gcc_checking_assert (!TYPE_P (expression));
> > +
> > STRIP_ANY_LOCATION_WRAPPER (expression);
> > /* An unresolved name is always dependent. */
> > diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
> > index cd7a2818feb..7f8502f49b0 100644
> > --- a/gcc/cp/semantics.cc
> > +++ b/gcc/cp/semantics.cc
> > @@ -4141,7 +4141,9 @@ finish_id_expression_1 (tree id_expression,
> > }
> > else
> > {
> > - bool dependent_p = type_dependent_expression_p (decl);
> > + /* DECL could be e.g. UNBOUND_CLASS_TEMPLATE which is a type which
> > + t_d_e_p doesn't accept. */
> > + bool dependent_p = !TYPE_P (decl) && type_dependent_expression_p
> > (decl);
>
> Maybe instead we could handle UNBOUND_CLASS_TEMPLATE at a higher level in
> the function, like with an 'else if' before this 'else'?
Maybe, but I think I'd have to duplicate (parts of) this block:
4227 else if (scope)
4228 {
4229 if (TREE_CODE (decl) == SCOPE_REF)
4230 {
4231 gcc_assert (same_type_p (scope, TREE_OPERAND (decl, 0)));
4232 decl = TREE_OPERAND (decl, 1);
4233 }
4234
4235 decl = (adjust_result_of_qualified_name_lookup
4236 (decl, scope, current_nonlambda_class_type()));
4237
4238 cp_warn_deprecated_use_scopes (scope);
4239
4240 if (TYPE_P (scope))
4241 decl = finish_qualified_id_expr (scope,
4242 decl,
4243 done,
4244 address_p,
4245 template_p,
4246 template_arg_p,
4247 tf_warning_or_error);
4248 else
4249 decl = convert_from_reference (decl);
4250 }
Would that be acceptable? Can't do
else if (TREE_CODE (decl) == UNBOUND_CLASS_TEMPLATE)
{
gcc_checking_assert (scope);
*idk = CP_ID_KIND_QUALIFIED;
goto do_scope;
}
because that will complain about skipping the initialization of dependent_p.
Here's a patch with the partial duplication, which passes dg.exp:
-- >8 --
As discussed here:
<https://gcc.gnu.org/pipermail/gcc-patches/2021-February/564629.html>,
type_dependent_expression_p should not be called with a type argument.
I promised I'd add an assert so here it is. One place needed adjusting.
PR c++/99080
gcc/cp/ChangeLog:
* pt.cc (type_dependent_expression_p): Assert !TYPE_P.
* semantics.cc (finish_id_expression_1): Handle UNBOUND_CLASS_TEMPLATE
specifically.
---
gcc/cp/pt.cc | 2 ++
gcc/cp/semantics.cc | 11 +++++++++++
2 files changed, 13 insertions(+)
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 24bbe2f4060..89156cb88b4 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -27727,6 +27727,8 @@ type_dependent_expression_p (tree expression)
if (expression == NULL_TREE || expression == error_mark_node)
return false;
+ gcc_checking_assert (!TYPE_P (expression));
+
STRIP_ANY_LOCATION_WRAPPER (expression);
/* An unresolved name is always dependent. */
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index cdc91a38e25..f62b0a4a736 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -4139,6 +4139,17 @@ finish_id_expression_1 (tree id_expression,
}
return r;
}
+ else if (TREE_CODE (decl) == UNBOUND_CLASS_TEMPLATE)
+ {
+ gcc_checking_assert (scope);
+ *idk = CP_ID_KIND_QUALIFIED;
+ decl = (adjust_result_of_qualified_name_lookup
+ (decl, scope, current_nonlambda_class_type()));
+ cp_warn_deprecated_use_scopes (scope);
+ decl = finish_qualified_id_expr (scope, decl, done, address_p,
+ template_p, template_arg_p,
+ tf_warning_or_error);
+ }
else
{
bool dependent_p = type_dependent_expression_p (decl);
base-commit: d822f4bbd714c6595f70cc68888dcebecfb6662d
--
2.36.1
