On 3/4/21 2:54 PM, Iain Sandoe wrote:
Hi,
From the PR:
The wording of [dcl.fct.def.coroutine]/15 states:
* The expression co_await promise.final_suspend() shall not be
potentially-throwing ([except.spec]).
See http://eel.is/c++draft/dcl.fct.def.coroutine#15
and http://eel.is/c++draft/except.spec#6
ie. all of the following must be declared noexcept (if they form part of the
await-expression):
- promise_type::final_suspend()
- finalSuspendObj.operator co_await()
- finalSuspendAwaiter.await_ready()
- finalSuspendAwaiter.await_suspend()
- finalSuspendAwaiter.await_resume()
- finalSuspedObj destructor
- finalSuspendAwaiter destructor
This implements the checks for these cases and rejects such code with
a diagnostic.
[ accepts invalid ]
tested on x86_64-darwin, x86_64-linux-gnu,
OK for master / 10.x?
thanks
Iain
gcc/cp/ChangeLog:
PR c++/95616
* coroutines.cc (coro_diagnose_throwing_fn): New helper.
(coro_diagnose_throwing_final_aw_expr): New helper.
(build_co_await): Diagnose throwing final await expression
components.
(build_init_or_final_await): Diagnose a throwing promise
final_suspend() call.
ok. Does this DTRT in the presence of -fno-exceptions? (i.e. use of
that flag means you don't have to decorate everything with noexcept)
nathan
--
Nathan Sidwell