https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116793
--- Comment #16 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-14 branch has been updated by Iain D Sandoe <ia...@gcc.gnu.org>: https://gcc.gnu.org/g:b4000f922425f7763bdab7bb8822975c0a669097 commit r14-11737-gb4000f922425f7763bdab7bb8822975c0a669097 Author: Arsen ArsenoviÄ <ar...@aarsen.me> Date: Tue Sep 24 18:16:01 2024 +0200 c++/coro: ignore cleanup_point_exprs while expanding awaits [PR116793] If we reach a CLEANUP_POINT_EXPR while trying to walk statements, we actually care about the statement or statement list contained within it. Indeed, such a construction started happening with r15-3513-g964577c31df206, after temporary promotion. In the test case presented in PR116793, the compiler generated: <<cleanup_point { struct _cleanup_task Aw0 [value-expr: frame_ptr->Aw0_2_3]; int T002 [value-expr: frame_ptr->T002_2_3]; int T002 [value-expr: frame_ptr->T002_2_3]; <<cleanup_point <<< Unknown tree: expr_stmt (void) (T002 = TARGET_EXPR <D.20994, 3>) >>>>>; struct _cleanup_task Aw0 [value-expr: frame_ptr->Aw0_2_3]; <<cleanup_point <<< Unknown tree: expr_stmt (void) (Aw0 = TARGET_EXPR <D.20995, func ((int &) &T002)>) >>>>>; <<cleanup_point <<< Unknown tree: expr_stmt (void) (D.22450 = <<< Unknown tree: co_await TARGET_EXPR <D.20995, func ((int &) &T002)> Aw0 {_cleanup_task::await_ready (&Aw0), _cleanup_task::await_suspend<_task1::promise_type> (&Aw0, TARGET_EXPR <D.21078, _Coro_self_handle>), <<< Unknown tree: aggr_init_expr 4 await_resume D.22443 &Aw0 >>>} 0 >>>) >>>>>; <<cleanup_point <<< Unknown tree: expr_stmt (void) (D.20991 = (struct tuple &) &D.22450) >>>>>; } D.22467 = 1; int & i [value-expr: frame_ptr->i_1_2]; <<cleanup_point <<< Unknown tree: expr_stmt (void) (i = std::get<0, int&> (NON_LVALUE_EXPR <D.20991>)) >>>>>;>>; ... i.e. a statement list within a cleanup point. In such a case, we don't actually care about the cleanup point, but we do care about the statement inside, so, we can just walk down into the CLEANUP_POINT_EXPR. PR c++/116793 gcc/cp/ChangeLog: * coroutines.cc (await_statement_expander): Just process subtrees if encountering a CLEANUP_POINT_EXPR. gcc/testsuite/ChangeLog: * g++.dg/coroutines/pr116793-1.C: New test. (cherry picked from commit d888a8a8dcf391197ae82e2bbf99507effc27950)
