https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109443
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Making the reference types to return or parameter non-POD types passed by value
restrict could be
--- gcc/cp/call.cc.jj 2023-03-30 09:34:05.609725768 +0200
+++ gcc/cp/call.cc 2023-04-13 09:56:53.226908996 +0200
@@ -9223,7 +9223,11 @@ type_passed_as (tree type)
{
/* Pass classes with copy ctors by invisible reference. */
if (TREE_ADDRESSABLE (type))
- type = build_reference_type (type);
+ {
+ type = build_reference_type (type);
+ type = build_qualified_type (type,
+ TYPE_QUALS (type) | TYPE_QUAL_RESTRICT);
+ }
else if (targetm.calls.promote_prototypes (NULL_TREE)
&& INTEGRAL_TYPE_P (type)
&& COMPLETE_TYPE_P (type)
--- gcc/cp/cp-gimplify.cc.jj 2023-03-15 15:36:02.500430556 +0100
+++ gcc/cp/cp-gimplify.cc 2023-04-13 09:57:51.989059798 +0200
@@ -2000,6 +2000,9 @@ cp_genericize (tree fndecl)
{
t = DECL_RESULT (fndecl);
TREE_TYPE (t) = build_reference_type (TREE_TYPE (t));
+ TREE_TYPE (t)
+ = build_qualified_type (TREE_TYPE (t), TYPE_QUALS (TREE_TYPE (t))
+ | TYPE_QUAL_RESTRICT);
DECL_BY_REFERENCE (t) = 1;
TREE_ADDRESSABLE (t) = 0;
relayout_decl (t);
Completely untested. Does this what we want? Stage1 material anyway...
