https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98704
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Iain D Sandoe <ia...@gcc.gnu.org>: https://gcc.gnu.org/g:020b286c769f4dc8a6b45491351f6bc2e69d7a7f commit r11-7676-g020b286c769f4dc8a6b45491351f6bc2e69d7a7f Author: Iain Sandoe <i...@sandoe.co.uk> Date: Thu Mar 11 17:04:14 2021 +0000 coroutines : Handle rethrow from unhandled_exception [PR98704]. Although there is still some discussion in CWG 2451 on this, the implementors are agreed on the intent. When promise.unhandled_exception () is entered, the coroutine is considered to be still running - returning from the method will cause the final await expression to be evaluated. If the method throws, that action is considered to make the coroutine suspend (since, otherwise, it would be impossible to reclaim its resources, since one cannot destroy a running coro). The wording issue is to do with how to represent the place at which the coroutine should be considered suspended. For the implementation here, that place is immediately before the promise life-time ends. A handler for the rethrown exception, can thus call xxxx.destroy() which will run DTORs for the promise and any parameter copies [as needed] then the coroutine frame will be deallocated. At present, we also set "done=true" in this case (for compatibility with other current implementations). One might consider 'done()' to be misleading in the case of an abnormal termination - that is also part of the CWG 2451 discussion. gcc/cp/ChangeLog: PR c++/98704 * coroutines.cc (build_actor_fn): Make destroy index 1 correspond to the abnormal unhandled_exception() exit. Substitute the proxy for the resume index. (coro_rewrite_function_body): Arrange to reset the resume index and make done = true for a rethrown exception from unhandled_exception (). (morph_fn_to_coro): Adjust calls to build_actor_fn and coro_rewrite_function_body. gcc/testsuite/ChangeLog: PR c++/98704 * g++.dg/coroutines/torture/pr98704.C: New test.
