Hi Adrian, thanks for digging in. I am not sure about the policies of the builders, I think we had failing test cases for a bunch of days & it may have already been red when your change went in, so it wasn't detected as a change in status. That might have something to do with it. I thought the behavior was like you described, too.
I don't know what tools are installed on the builder but I'll ask around the office on Monday, I know there are people who are more familiar with how these bots are set up. J > On Nov 25, 2022, at 2:22 PM, Adrian Vogelsgesang > <avogelsges...@salesforce.com> wrote: > > Hm... wait a second... > > Which clang-version is > https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/ using? Is it using > an older version of clang? Does that version already contain the patch > https://reviews.llvm.org/D132580? > > If not, that might explain things... > > On Fri, Nov 25, 2022 at 11:18 PM Adrian Vogelsgesang > <avogelsges...@salesforce.com> wrote: > Hi Jason, > > Sorry for the late reply - your mail got caught in my spam filter, and I just > realized about the build breakage now after you reverted the commits. Just to > confirm: > > I looked at the original change again, and I think I know what's going wrong > here: Devirtualization fails, and `promise_type` stays `void`. Obviously, > `CreateValueObjectFromAddress` cannot create an object of type `void` and > fails. The previous version was robust against that scenario, but > https://reviews.llvm.org/D132815 accidentally regressed this. > > If a program has all the expected debug info, devirtualization should never > fail and `promise_type` never stays `void`. It seems something is > wrong/unexpected with the debug info on Darwin. Devirtualization relies on > being able to identify the function pointer of the `destroy` function and > inspects that function. So the root cause seems to be the same as for the > revert > https://github.com/llvm/llvm-project/commit/2b2f2f66141d52dc0d3082ddd12805d36872a189: > For some reason, the debugger cannot find debug info for the function > pointed to by the `destroy` function. > > However, I still don't quite understand what's wrong with the debug info on > Mac. > > Either way, the pretty printer should of course be robust against such > unexpected debug info. I think a simple additional check should be enough to > make this robust so we no longer crash: > if (!promise_type.isVoid()) { // <---- additional check > lldb::ValueObjectSP promise = CreateValueObjectFromAddress( > "promise", frame_ptr_addr + 2 * ptr_size, exe_ctx, promise_type); > Status error; > lldb::ValueObjectSP promisePtr = promise->AddressOf(error); > if (error.Success()) > m_promise_ptr_sp = promisePtr->Clone(ConstString("promise")); > } > > Meta question: I am a bit confused about > https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/. I thought LLVM's > buildbots were set up to send an email in case somebody breaks the build. > Also, I made sure that all builds in https://lab.llvm.org/buildbot/#/builders > stayed green after my commit. So what are the expectations around which CIs > need to stay green after a commit? Do I need to setup anything such that > green.lab.llvm.org also sends me an email if I break it? > > Cheers, > Adrian > > On Thu, Nov 24, 2022 at 10:50 PM Jason Molenda <ja...@molenda.com> wrote: > Ah, little misstatement below. My first thought was that promise_type was > null, but when I stepped through here with a debugger, it was not. I didn't > know how to dig in to a CompilerType object but there was some reason why > this CreateValueObjectFromAddress failed to return an actual ValueObject, and > I assumed it's something to do with that CompilerType. But I didn't dig in > far enough to understand what the issue in the type was. > > > On Nov 24, 2022, at 1:20 PM, Jason Molenda <ja...@molenda.com> wrote: > > > > Hi Adrian, the green dragon Incremental CI bot has been failing the past > > couple of days after the changes for the coroutines formatter, most > > directly https://reviews.llvm.org/D132815 landed - TestCoroutineHandle.py > > results in a segfault on Darwin systems (both on the CI and on my mac > > desktop) consistently. > > https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/ > > > > It's crashing in formatters::StdlibCoroutineHandleSyntheticFrontEnd where > > you're doing > > > > ``` > > // Add the `promise` member. We intentionally add `promise` as a pointer > > type > > // instead of a value type, and don't automatically dereference this > > pointer. > > // We do so to avoid potential very deep recursion in case there is a > > cycle in > > // formed between `std::coroutine_handle`s and their promises. > > lldb::ValueObjectSP promise = CreateValueObjectFromAddress( > > "promise", frame_ptr_addr + 2 * ptr_size, exe_ctx, promise_type); > > Status error; > > lldb::ValueObjectSP promisePtr = promise->AddressOf(error); > > ``` > > > > and the promise_type dose not have a CompilerType so promisePtr is nullptr > > and we crash on the method call to AddressOf. I looked briefly, but this > > isn't a part of lldb I know well and I'm not sure the nature of the problem. > > > > It's a long weekend in the US, so if you have a suggestion for addressing > > this that'd be great, or I can roll back the changes necessary to get the > > bot clean later today and we can look at this next week. > > > > Thanks! > > _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
