On 8/22/24 3:43 PM, Iain Sandoe wrote:
On 22 Aug 2024, at 17:47, Jason Merrill <ja...@redhat.com> wrote:
On 8/22/24 12:35 PM, Iain Sandoe wrote:
+build_coroutine_frame_delete_expr (tree coro_fp, tree orig, tree frame_size,
+ tree promise_type, location_t loc)
+{
Here it seems like you could already use build_op_delete_call for all of this,
just by converting coro_fp to pointer-to-promise_type instead of to
ptr_type_node?
I am missing something - the frame pointer is not a pointer to a promise object
it is a pointer to the whole coroutine state?
Yes, but you could lie about that; build_op_delete_call only uses the type for
lookup (which we want to do in the promise type), then converts to void*.
hmm I’m having trouble with this, but not sure what I’m doing wrong - this is
what I have now:
...
tree pptr_type = build_pointer_type (promise_type);
tree frame_arg = build1_loc (loc, CONVERT_EXPR, pptr_type, coro_fp);
…
del_coro_fr = build_op_delete_call (DELETE_EXPR, frame_arg, frame_size,
/*global_p=*/false,
/*placement=*/NULL,
/*alloc_fn=*/NULL,
tf_warning_or_error);
http://eel.is/c++draft/dcl.fct.def.coroutine#12 (sentence 2) says " If both a
usual deallocation function with only a pointer parameter and a usual deallocation
function with both a pointer parameter and a size parameter are found, then the
selected deallocation function shall be the one with two parameters.”
however, if my promise provides both - the one with a single param is always
chosen.
It is not that the other overload is invalid - if I do not include the single
param version, the two param one is happily selected.
(I’m stumped at the moment)
Ah, that's backwards from https://eel.is/c++draft/expr.delete#9.4 "If
the deallocation functions belong to a class scope, the one without a
parameter of type std::size_t is selected."
This is implemented as
/* -- If the deallocation functions have class scope, the one
without a parameter of type std::size_t is selected. */
bool want_size;
if (DECL_CLASS_SCOPE_P (fn))
want_size = false;
I guess we need some way for build_op_delete_call to know that we want
the other preference in this case.
Jason
