https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95616
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Iain D Sandoe <ia...@gcc.gnu.org>: https://gcc.gnu.org/g:00f703000fea2e8384f643413b53baa66ec4ddc2 commit r10-9513-g00f703000fea2e8384f643413b53baa66ec4ddc2 Author: Iain Sandoe <i...@sandoe.co.uk> Date: Mon Feb 15 17:11:31 2021 +0000 coroutines : Do not accept throwing final await expressions [PR95616]. 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 if exceptions are enabled. Backported from 9ee91079fd5879cba046e452ab5593372166b2ab and 4e252e23d34932f13f39cc6544bf5c9379fa2a87 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. Look through NOP_EXPRs inbuild_special_member_call return value to find the CALL_EXPR. Simplify. (build_init_or_final_await): Diagnose a throwing promise final_suspend() call. gcc/testsuite/ChangeLog: PR c++/95616 * g++.dg/coroutines/pr95616-0-no-exceptions.C: New test. * g++.dg/coroutines/pr95616-0.C: New test. * g++.dg/coroutines/pr95616-1-no-exceptions.C: New test. * g++.dg/coroutines/pr95616-1.C: New test. * g++.dg/coroutines/pr95616-2.C: New test. * g++.dg/coroutines/pr95616-3-no-exceptions.C: New test. * g++.dg/coroutines/pr95616-3.C: New test. * g++.dg/coroutines/pr95616-4.C: New test. * g++.dg/coroutines/pr95616-5.C: New test. * g++.dg/coroutines/pr95616-6.C: New test. Co-authored-by: Jakub Jelinek <ja...@redhat.com>