junparser added a comment. In D89066#2325358 <https://reviews.llvm.org/D89066#2325358>, @lxfind wrote:
> In D89066#2324291 <https://reviews.llvm.org/D89066#2324291>, @junparser wrote: > >> In D89066#2324151 <https://reviews.llvm.org/D89066#2324151>, @lxfind wrote: >> >>> In D89066#2324115 <https://reviews.llvm.org/D89066#2324115>, @junparser >>> wrote: >>> >>>> why we should not do this with normal await call? >>> >>> To be honest, I don't know yet. My understanding of how expression cleanup >>> and temp lifetime management is insufficient at the moment. >>> But first of all, without adding any cleanup expression here, I saw ASAN >>> failures due to heap-use-after-free, because sometimes the frame have >>> already been destroyed after the await_suspend call, and yet we are still >>> writing into the frame due to unnecessarily cross-suspend lifetime. >>> However, if I apply the cleanup to all await_suepend calls, it also causes >>> ASAN failures as it's cleaning up data that's still alive. >>> So this patch is more of a temporary walkaround to stop bleeding without >>> causing any trouble. >>> I plan to get back to this latter after I am done with the spilling/alloca >>> issues. >> >> I'm not familiar with ASAN instrumentation. Do you have any testcases to >> explain this? > > Unfortunately I don't. But this is not related to ASAN. Basically, this is > causing destructing of objects that should still be alive. I suspect that > it's because ExprWithCleanups always clean up temps that belongs to the full > expression, not just the sub-expression in it. should we also need to add ExprWithCleanups when expand co_await to await_ready & await_suspend and await_resume expression which may fix this issue？ Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D89066/new/ https://reviews.llvm.org/D89066 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
