I think I might be a little lost. I built a lldb in debug mode and I am running lldb in an lldb debugger (very meta). Earlier in the thread you said "we need a better error message when vAttachWait returns unsupported" I have found where the error message, e.g., "error: attach failed: lost connection" is constructed. The "attach failed: " comes from here [1] and the "lost connection" comes from here [2]. What do you mean by "vAttachWait"? Am I missing something obvious?
It seems like you are expecting lldb-server to be the place where the fix will be implemented. Though in the debugger I'm seeing the method Target::Attach() [3] as the place where the connection attempt is made and fails. [1] https://github.com/apple/swift-lldb/blob/a8c149f75a8cba674bead048cd9c80ddc8166a8a/source/Commands/CommandObjectProcess.cpp#L518[2] https://github.com/apple/swift-lldb/blob/a8c149f75a8cba674bead048cd9c80ddc8166a8a/source/Target/Target.cpp#L3444-L3445[3] https://github.com/apple/swift-lldb/blob/a8c149f75a8cba674bead048cd9c80ddc8166a8a/source/Target/Target.cpp#L3374 On Mon, Jun 4, 2018, at 7:04 PM, Greg Clayton wrote: > I will be too busy this week to get to this, so please do have a > stab at it.> > Basically the flow that debug server does is: > 1 - get a list of all processes whose basename matches and remember > those pids so we don't try to attach to them since we are waiting for > a new process to show up> 2 - poll the OS for the process list and wait for a > new pid to show up > with the basename and attach to the first one that matches whose pid > isn't i the list from step #1> > On MacOSX we don't have a way to be notified of new processes are > spawned, not sure on other unix variants. If it is possible, we would > want change to:> 1 - sign up to be notified about new processes > 2 - as each process gets launched, check for a match and attach as > quickly as possible> > Hope this helps and I look forward to seeing your patch! > > Greg > >> On Jun 4, 2018, at 5:56 AM, Ryan Lovelett <r...@lovelett.me> wrote: >> >> Greg, >> >> Is there anything I can do to help you implement or test this >> feature? Obviously I'm willing to roll-up my sleeves and work on this >> myself too if you've become more busy than you expected. That happens >> to us all and I completely understand.>> >> Not being able to debug in this manner is blocking me from adding >> Linux support to a Swift program. As you might imagine, I'm a little >> antsy to get past this so I can start writing some code.>> >> On Thu, May 31, 2018, at 5:08 PM, Greg Clayton wrote: >>> >>> >>>> On May 31, 2018, at 12:40 PM, Ryan Lovelett <r...@lovelett.me> >>>> wrote:>>>> >>>> Well at least there is a little good news. I understood way more of >>>> those logs than I thought I did.>>>> >>>>> So two issues here: >>>>> 1 - we need a better error message when vAttachWait returns >>>>> unsupported>>>>> 2 - fix lldb-server to support vAttachWait >>>> >>>> A few questions. >>>> >>>> What is the protocol here? Can/should I report the issues at >>>> https://bugs.llvm.org/ ? Or is that something that a project member >>>> needs to do? Assuming that I can, would this be two seperate issues >>>> or one "large" issue?>>>> >>>> Barring that this is not something someone else might implement >>>> better/faster than me. Considering I have zero LLDB development >>>> experience is this something that I could tackle?>>> >>> I didn't realize this functionality was missing in lldb-server. I >>> can take a stab at implementing it and see what I can do. Stay >>> tuned.>>> >>>> >>>> On Thu, May 31, 2018, at 3:02 PM, Greg Clayton wrote: >>>>> lldb-server claims it doesn't support it: >>>>> >>>>> lldb < 48> send packet: >>>>> $vAttachWait;6c616e677365727665722d7377696674#d6>>>>> lldb < >>>>> 4> read packet: $#00 >>>>> >>>>> >>>>> Returning the empty packet ("$#00") means it is not supported, but >>>>> we really should give a better error message than this.>>>>> >>>>> It isn't that hard to implement. It would be easy to copy the code >>>>> that is in debugserver in DNB.cpp in the DNBProcessAttachWait >>>>> function. Most of it is probably posix style stuff.>>>>> >>>>> So two issues here: >>>>> 1 - we need a better error message when vAttachWait returns >>>>> unsupported>>>>> 2 - fix lldb-server to support vAttachWait >>>>> >>>>> Greg >>>>> >>>>> >>>>>> On May 31, 2018, at 11:04 AM, Ryan Lovelett <r...@lovelett.me> >>>>>> wrote:>>>>>> >>>>>>> It might be a lldb-server issue? >>>>>> >>>>>> How would one go about determining this? >>>>>> >>>>>> (lldb) log enable -f /tmp/packates.txt gdb-remote packets >>>>>> (lldb) process attach --name "<name>" --waitfor >>>>>> error: attach failed: lost connection >>>>>> >>>>>> Attached the log output. Maybe it'll make more sense to you than >>>>>> me.>>>>>> >>>>>> That escalated quickly. So I've read through that log. I found >>>>>> something that says $qVAttachOrWaitSupported#38 with the >>>>>> following response being $#00. Perhaps I'm reading too much but >>>>>> is it that it's reporting that it is not supported?>>>>>> >>>>>> Does lldb-server need to be compiled in a certain way to add >>>>>> support for attach wait?>>>>>> >>>>>> On Thu, May 31, 2018, at 1:49 PM, Greg Clayton wrote: >>>>>>> Try enabling logging with: >>>>>>> >>>>>>> (lldb) log enable -f /tmp/packets.txt gdb-remote packets >>>>>>> >>>>>>> And the try the attach. It might be a lldb-server issue? >>>>>>> >>>>>>>> On May 31, 2018, at 9:02 AM, Ryan Lovelett via lldb-dev <lldb- >>>>>>>> d...@lists.llvm.org> wrote:>>>>>>>> >>>>>>>> I am attempting to use: process attach --name "<name>" -- >>>>>>>> waitfor>>>>>>>> >>>>>>>> The problem is that it immediately returns error: attach >>>>>>>> failed: lost connection.>>>>>>>> >>>>>>>> Is this something I can troubleshoot further? Or is this not >>>>>>>> supported on Linux?>>>>>>>> >>>>>>>> -- >>>>>>>> Ryan Lovelett >>>>>>>> _______________________________________________ >>>>>>>> lldb-dev mailing list >>>>>>>> lldb-dev@lists.llvm.org >>>>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev >>>>>> <packates.txt>
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