ilya-biryukov added inline comments.
================ Comment at: clangd/ClangdLSPServer.cpp:412 + llvm::raw_string_ostream OS(Message); + OS << "method not found (" << Method << ")"; + replyError(ErrorCode::MethodNotFound, OS.str()); ---------------- simark wrote: > simark wrote: > > ilya-biryukov wrote: > > > malaperle wrote: > > > > simark wrote: > > > > > ilya-biryukov wrote: > > > > > > Could we also `log` (i.e. not `vlog`) names of the methods that > > > > > > were handled successfully? To have some context when something > > > > > > crashes and we only have non-verbose logs. > > > > > That would be against the purpose of this patch, which is to output > > > > > nothing if everything goes right (so it's easier to notice when > > > > > something goes wrong). Just outputting the names of the methods that > > > > > are handled successfully would still be very verbose I think. > > > > Wouldn't that mean pretty much logging everything coming in? The idea > > > > of this patch it to make it that by default Clangd is not talkative > > > > unless there is an error and optionally make it verbose, for > > > > troubleshooting. > > > Logs are also useful to diagnose problems in case something crashes or > > > works incorrectly. > > > Clang will probably log something when processing any request anyway, > > > logging the method name first will merely give some more context on which > > > request other log messages correspond to. > > > > > > > The idea of this patch it to make it that by default Clangd is not > > > > talkative unless there is an error. > > > I don't think we use logging this way in clangd. Logs give us a way to > > > make sense of what's happening inside clangd even when there's no error. > > > `vlog` lets us turn off some extremely noisy output that is not useful > > > most of the time. > > > We have a whole bunch of log statements that don't correspond to errors > > > (e.g. "reusing preamble", "building file with compile command"). > > > Logs are also useful to diagnose problems in case something crashes or > > > works incorrectly. > > Clang will probably log something when processing any request anyway, > > logging the method name first will merely give some more context on which > > request other log messages correspond to. > > > > I think it's fine if clangd logs warning/errors by default, that a user > > might want to look at and address. But logging things that happen > > recurrently and are part of clangd's normal operation just flood the > > terminal (and makes it harder to spot actual errors). > > > > I agree that having some context helps to make sense of an error. A > > reasonnable way would be to include the method name only when printing an > > error. For example, `While handling method 'workspace/symbol': Could not > > open file foo.`. That would require us to carry around some more context > > information, but I think it would be better than printing all the handled > > methods. > > > > > I don't think we use logging this way in clangd. Logs give us a way to > > > make sense of what's happening inside clangd even when there's no error. > > > > In that case you turn on a more verbose log level. > > > > > vlog lets us turn off some extremely noisy output that is not useful most > > > of the time. We have a whole bunch of log statements that don't > > > correspond to errors (e.g. "reusing preamble", "building file with > > > compile command"). > > > > I would consider everything that happens at each json-rpc request to be > > "noisy". When using clangd from an IDE, there's quite a lot of requests > > being done. I was also thinking of modyfing the patch to also use vlog for > > the "reusing preamble" and "building file with compile command" messages. > One more thing: when using multiple workers and the asynchronous model, the > error may not be related to the last printed method name: > > ``` > Handling json-rpc method A > Handling json-rpc method B > Some error related to the handling of request A > ``` > > If you just see the error like this, you would think it's cause by request B, > even though it's when handling request A. Passing some context to the > callback would allow us to print the request which is really at the origin of > the error, avoiding any confusion. And it would allow us to not print it if > everything goes fine. clangd logs were never designed to fire only on errors. I probably misread the patch initially, are you trying to change `log` into something used only for logging errors? Could you give a bit more context for your use-case in order to understand it better? - How do you use the log output? Is it shown to the end user? - What information do you want to extract from the logs apart from the fact that an error happened? - Why are JSON RPC error responses not enough to indicate errors? What benefits do logs provide over them? Repository: rCTE Clang Tools Extra https://reviews.llvm.org/D44226 _______________________________________________ cfe-commits mailing list firstname.lastname@example.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits