Re: [PATCH] coroutines: Amend parameter handling to match n4849.

[Nathan Sidwell]

On 2/26/20 8:43 AM, Iain Sandoe wrote:
This is the second in the series to bring the GCC implementation into line
with the current standard.


2020-02-26  Iain Sandoe  <i...@sandoe.co.uk>

        * coroutines.cc (struct param_info): Keep track of params
        that are references, and cache the original type and whether
        the DTOR is trivial.
        (build_actor_fn): Handle param copies always, and adjust the
        handling for references.
        (register_param_uses): Only handle uses here.
        (classtype_has_non_deleted_copy_ctor): New.
        (morph_fn_to_coro): Adjust param copy handling to match n4849
        by reordering ahead of the promise CTOR and always making a
        frame copy, even if the param is unused in the coroutine body.

Ok, modulo a couple of changes:

@@ -1742,6 +1742,11 @@ struct param_info
    tree field_id;
    vec<tree *> *body_uses;
    tree frame_type;
+  tree orig_type;
+  bool by_ref;
+  bool rv_ref;
+  bool pt_ref;
+  bool trivial_dtor;
  };

Can you comment the fields here?

+bool
+classtype_has_non_deleted_copy_ctor (tree t)
+{
+  if (CLASSTYPE_LAZY_COPY_CTOR (t))
+    lazily_declare_fn (sfk_copy_constructor, t);
+  for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter)
+    if (copy_fn_p (*iter) && !DECL_DELETED_FN (*iter))
+      return true;
+  return false;
+}

Please put this in class.c next to the non deleted move ctor variant. 
Needs a comment.

Ok with those changes, no need to re-review.

nathan

--
Nathan Sidwell