https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103328
--- Comment #25 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:a77c9efdeb9ecad14ecca73db0e45fcd9d884382 commit r11-9789-ga77c9efdeb9ecad14ecca73db0e45fcd9d884382 Author: Benno Evers <benno.ev...@tenzir.com> Date: Sat Apr 2 17:22:33 2022 +0100 c++: Fix ICE due to shared BLOCK node in coroutine generation [PR103328] When finishing a function that is a coroutine, the function is transformed into a "ramp" function, and the original user-provided function body gets moved into a newly created "actor" function. In this case `current_function_decl` points to the ramp function, but `current_binding_level->blocks` would still point to the scope block of the user-provided function body in the actor function, so when the ramp function was finished during `poplevel()` in decl.cc, we could end up with that block being reused as the `DECL_INITIAL()` of the ramp function: subblocks = functionbody >= 0 ? current_binding_level->blocks : 0; // [...] DECL_INITIAL (current_function_decl) = block ? block : subblocks; This block would then be independently modified by subsequent passes touching either the ramp or the actor function, potentially causing an ICE depending on the order and function of these passes. gcc/cp/ChangeLog: PR c++/103328 * coroutines.cc (morph_fn_to_coro): Reset current_binding_level->blocks. gcc/testsuite/ChangeLog: PR c++/103328 * g++.dg/coroutines/pr103328.C: New test. Co-Authored-By: Iain Sandoe <i...@sandoe.co.uk> (cherry picked from commit 0847ad33b908af88bca1e6980d0b977316d05e18)