[PATCH] D96717: [clangd] Bind outgoing calls through LSPBinder too. NFC

[Kadir Cetinkaya via Phabricator via cfe-commits]

kadircet accepted this revision.
kadircet added a comment.
This revision is now accepted and ready to land.

thanks! can't wait for the unique_function sfinae fix :)



================
Comment at: clang-tools-extra/clangd/LSPBinder.h:185
+
+LSPBinder::UntypedOutgoingNotification inline LSPBinder::outgoingNotification(
+    llvm::StringLiteral Method) {
----------------
maybe put `inline` at the start of the declaration ? :D


================
Comment at: clang-tools-extra/clangd/LSPBinder.h:88
+  template <typename Request, typename Response>
+  void outgoingMethod(llvm::StringLiteral Method,
+                      OutgoingMethod<Request, Response> &Handler) {
----------------
sammccall wrote:
> kadircet wrote:
> > well this one filling an out-parameter definitely tripped me over while reading the code a couple times, and once more on the tests.
> > 
> > what about making this return the handler instead? E.g. `Edit = Bind.outgoingMethod<EditParams, EditResult>("edit")`, I know it is ugly that we duplicate template params on declaration + here now. Maybe we can get away by making `OutgoingMethod` a class with a call operator and a `RawOutgoing *Out` member that can be bound later on ? e.g:
> > 
> > ```
> > template <StringLiteral Method, typename P, typename R>
> > class OutgoingMethod {
> >   RawOutgoing *Out = nullptr;
> > public:
> >   void operator()(const P& Params, Callback<R> CB) {
> >     assert(Out && "Method haven't bound");
> >     Out->callMethod(Method, JSON(Params), ....);
> >   }
> > };
> > ```
> > 
> > then we either make LSPBinder a friend of OutgoingMethod and set Out through it, or the other way around and have a `OutgoingMethod::bindOut(LSPBinder&)` ?
> > 
> > not sure if it is any better though, as we still construct a somewhat invalid object :/
> > well this one filling an out-parameter definitely tripped me over while reading the code a couple times, and once more on the tests.
> 
> Yup. My feeling is the wins are:
>  - avoid writing the types over and over (we can't really avoid it on the instance variable)
>  - resembles syntax for binding incoming things
> 
> And the main loss is definitely that we're not using assignment syntax for assignment.
> 
> > what about making this return the handler instead? E.g. Edit = Bind.outgoingMethod<EditParams, EditResult>("edit")
> 
> This is a reasonable alternative, as you say the duplication is the downside.
> 
> > Maybe we can get away by making OutgoingMethod a class with a call operator
> 
> Yeah, I don't really understand what this achieves - the usage looks the same, just now the logical assignment doesn't use assignment syntax *or* assignment semantics :-)
> 
> Other ideas I had:
>  - the object is untyped, and the call operator is templated/typed - no type-safety at callsite, yuck
>  - `outgoingMethod` returns an untyped proxy object with a template conversion operator to unique_function<Req, Rsp>. This gives us assignment syntax... and horrible compiler errors on mismatch.
> 
> I'm going to try the latter out to see how bad it is.
thanks! this looks a whole lot better!


================
Comment at: clang-tools-extra/clangd/unittests/ClangdLSPServerTests.cpp:237
+      Value += X;
+      Changed(Value);
+    }
----------------
sammccall wrote:
> whoops, after rebasing against 40cc63ea6eec7874d3a358f9fa549ef2f6543512 this uncovered a bug - we're testing the public API from the wrong thread (server thread != main thread).
> 
> So I've had to remove that test in this patch. We can test public APIs again in D96755.
yikes, i see what you mean now.. (i was searching for the failure in the previous commit you mentioned)


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D96717/new/

https://reviews.llvm.org/D96717