<div dir="ltr">Hm... wait a second...<br><br>Which clang-version is <a href="https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/">https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/</a> using? Is it using an older version of clang? Does that version already contain the patch <a href="https://reviews.llvm.org/D132580">https://reviews.llvm.org/D132580</a>?<br><br>If not, that might explain things...</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Nov 25, 2022 at 11:18 PM Adrian Vogelsgesang <<a href="mailto:avogelsgesang@salesforce.com">avogelsgesang@salesforce.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi Jason,<br><br>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: <br><br>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 <a href="https://reviews.llvm.org/D132815" target="_blank">https://reviews.llvm.org/D132815</a> accidentally regressed this.<br><br>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 <a href="https://github.com/llvm/llvm-project/commit/2b2f2f66141d52dc0d3082ddd12805d36872a189" target="_blank">https://github.com/llvm/llvm-project/commit/2b2f2f66141d52dc0d3082ddd12805d36872a189</a>: For some reason, the debugger cannot find debug info for the function pointed to by the `destroy` function.<br><br>However, I still don't quite understand what's wrong with the debug info on Mac.<br><br>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:<br>if (!promise_type.isVoid()) { // <---- additional check<br> lldb::ValueObjectSP promise = CreateValueObjectFromAddress(<br> "promise", frame_ptr_addr + 2 * ptr_size, exe_ctx, promise_type);<br> Status error;<br> lldb::ValueObjectSP promisePtr = promise->AddressOf(error);<br> if (error.Success())<br> m_promise_ptr_sp = promisePtr->Clone(ConstString("promise"));<br>}<br><br>Meta question: I am a bit confused about <a href="https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/" rel="noreferrer" target="_blank">https://green.lab.llvm.org/green/view/<span>LLDB</span>/job/<span>lldb</span>-cmake/</a>. 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 <a href="https://lab.llvm.org/buildbot/#/builders" target="_blank">https://lab.llvm.org/buildbot/#/builders</a> 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 <a href="http://green.lab.llvm.org" target="_blank">green.lab.llvm.org</a> also sends me an email if I break it?<br><br>Cheers,<br>Adrian</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Nov 24, 2022 at 10:50 PM Jason Molenda <<a href="mailto:jason@molenda.com" target="_blank">jason@molenda.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">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.<br>
<br>
> On Nov 24, 2022, at 1:20 PM, Jason Molenda <<a href="mailto:jason@molenda.com" target="_blank">jason@molenda.com</a>> wrote:<br>
> <br>
> 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 <a href="https://reviews.llvm.org/D132815" rel="noreferrer" target="_blank">https://reviews.llvm.org/D132815</a> landed - TestCoroutineHandle.py results in a segfault on Darwin systems (both on the CI and on my mac desktop) consistently. <a href="https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/" rel="noreferrer" target="_blank">https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/</a><br>
> <br>
> It's crashing in formatters::StdlibCoroutineHandleSyntheticFrontEnd where you're doing<br>
> <br>
> ```<br>
> // Add the `promise` member. We intentionally add `promise` as a pointer type<br>
> // instead of a value type, and don't automatically dereference this pointer.<br>
> // We do so to avoid potential very deep recursion in case there is a cycle in<br>
> // formed between `std::coroutine_handle`s and their promises.<br>
> lldb::ValueObjectSP promise = CreateValueObjectFromAddress(<br>
> "promise", frame_ptr_addr + 2 * ptr_size, exe_ctx, promise_type);<br>
> Status error;<br>
> lldb::ValueObjectSP promisePtr = promise->AddressOf(error);<br>
> ```<br>
> <br>
> 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.<br>
> <br>
> 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. <br>
> <br>
> Thanks!<br>
<br>
<br>
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</blockquote></div>