On Thu, 1 Jun 2023 at 04:13, Jason Merrill via Libstdc++ <
libstd...@gcc.gnu.org> wrote:
> Tested x86_64-pc-linux-gnu, OK for trunk?
>
OK, thanks.
>
> -- 8< --
>
> In the ABI's two-phase EH model, first we walk the stack looking for a
> handler, then we walk the stack running cleanups until we reach that
> handler. In the cleanup phase, we shouldn't redundantly check the handlers
> along the way, e.g. when walking through g():
>
> void f() { throw 42; }
> void g() { try { f(); } catch (void *) { } }
> int main() { try { g(); } catch (int) { } }
>
> libstdc++-v3/ChangeLog:
>
> * libsupc++/eh_personality.cc (PERSONALITY_FUNCTION): Don't check
> handlers in the cleanup phase.
> ---
> libstdc++-v3/libsupc++/eh_personality.cc | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/libstdc++-v3/libsupc++/eh_personality.cc
> b/libstdc++-v3/libsupc++/eh_personality.cc
> index 12391e563d6..cc6bc048892 100644
> --- a/libstdc++-v3/libsupc++/eh_personality.cc
> +++ b/libstdc++-v3/libsupc++/eh_personality.cc
> @@ -592,6 +592,10 @@ PERSONALITY_FUNCTION (int version,
> // Zero filter values are cleanups.
> saw_cleanup = true;
> }
> + else if (actions == _UA_CLEANUP_PHASE)
> + // We checked the handlers in the search phase; if one of them
> + // matched, actions would also have _UA_HANDLER_FRAME set.
> + ;
> else if (ar_filter > 0)
> {
> // Positive filter values are handlers.
>
> base-commit: 68816ba245afc6d0e1482bde2d15b35b925b4195
> --
> 2.31.1
>
>
