| //===--- JSONRPCDispatcher.cpp - Main JSON parser entry point -------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "JSONRPCDispatcher.h" |
| #include "JSONExpr.h" |
| #include "ProtocolHandlers.h" |
| #include "Trace.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/Support/Chrono.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include <istream> |
| |
| using namespace clang; |
| using namespace clangd; |
| |
| namespace { |
| static Key<json::Expr> RequestID; |
| static Key<JSONOutput *> RequestOut; |
| |
| // When tracing, we trace a request and attach the repsonse in reply(). |
| // Because the Span isn't available, we find the current request using Context. |
| class RequestSpan { |
| RequestSpan(json::obj *Args) : Args(Args) {} |
| std::mutex Mu; |
| json::obj *Args; |
| static Key<std::unique_ptr<RequestSpan>> RSKey; |
| |
| public: |
| // Return a context that's aware of the enclosing request, identified by Span. |
| static Context stash(const trace::Span &Span) { |
| return Context::current().derive( |
| RSKey, std::unique_ptr<RequestSpan>(new RequestSpan(Span.Args))); |
| } |
| |
| // If there's an enclosing request and the tracer is interested, calls \p F |
| // with a json::obj where request info can be added. |
| template <typename Func> static void attach(Func &&F) { |
| auto *RequestArgs = Context::current().get(RSKey); |
| if (!RequestArgs || !*RequestArgs || !(*RequestArgs)->Args) |
| return; |
| std::lock_guard<std::mutex> Lock((*RequestArgs)->Mu); |
| F(*(*RequestArgs)->Args); |
| } |
| }; |
| Key<std::unique_ptr<RequestSpan>> RequestSpan::RSKey; |
| } // namespace |
| |
| void JSONOutput::writeMessage(const json::Expr &Message) { |
| std::string S; |
| llvm::raw_string_ostream OS(S); |
| if (Pretty) |
| OS << llvm::formatv("{0:2}", Message); |
| else |
| OS << Message; |
| OS.flush(); |
| |
| { |
| std::lock_guard<std::mutex> Guard(StreamMutex); |
| Outs << "Content-Length: " << S.size() << "\r\n\r\n" << S; |
| Outs.flush(); |
| } |
| log(llvm::Twine("--> ") + S); |
| } |
| |
| void JSONOutput::log(const Twine &Message) { |
| llvm::sys::TimePoint<> Timestamp = std::chrono::system_clock::now(); |
| trace::log(Message); |
| std::lock_guard<std::mutex> Guard(StreamMutex); |
| Logs << llvm::formatv("[{0:%H:%M:%S.%L}] {1}\n", Timestamp, Message); |
| Logs.flush(); |
| } |
| |
| void JSONOutput::mirrorInput(const Twine &Message) { |
| if (!InputMirror) |
| return; |
| |
| *InputMirror << Message; |
| InputMirror->flush(); |
| } |
| |
| void clangd::reply(json::Expr &&Result) { |
| auto ID = Context::current().get(RequestID); |
| if (!ID) { |
| log("Attempted to reply to a notification!"); |
| return; |
| } |
| RequestSpan::attach([&](json::obj &Args) { Args["Reply"] = Result; }); |
| Context::current() |
| .getExisting(RequestOut) |
| ->writeMessage(json::obj{ |
| {"jsonrpc", "2.0"}, |
| {"id", *ID}, |
| {"result", std::move(Result)}, |
| }); |
| } |
| |
| void clangd::replyError(ErrorCode code, const llvm::StringRef &Message) { |
| log("Error " + Twine(static_cast<int>(code)) + ": " + Message); |
| RequestSpan::attach([&](json::obj &Args) { |
| Args["Error"] = |
| json::obj{{"code", static_cast<int>(code)}, {"message", Message.str()}}; |
| }); |
| |
| if (auto ID = Context::current().get(RequestID)) { |
| Context::current() |
| .getExisting(RequestOut) |
| ->writeMessage(json::obj{ |
| {"jsonrpc", "2.0"}, |
| {"id", *ID}, |
| {"error", |
| json::obj{{"code", static_cast<int>(code)}, {"message", Message}}}, |
| }); |
| } |
| } |
| |
| void clangd::call(StringRef Method, json::Expr &&Params) { |
| // FIXME: Generate/Increment IDs for every request so that we can get proper |
| // replies once we need to. |
| RequestSpan::attach([&](json::obj &Args) { |
| Args["Call"] = json::obj{{"method", Method.str()}, {"params", Params}}; |
| }); |
| Context::current() |
| .getExisting(RequestOut) |
| ->writeMessage(json::obj{ |
| {"jsonrpc", "2.0"}, |
| {"id", 1}, |
| {"method", Method}, |
| {"params", std::move(Params)}, |
| }); |
| } |
| |
| void JSONRPCDispatcher::registerHandler(StringRef Method, Handler H) { |
| assert(!Handlers.count(Method) && "Handler already registered!"); |
| Handlers[Method] = std::move(H); |
| } |
| |
| bool JSONRPCDispatcher::call(const json::Expr &Message, JSONOutput &Out) const { |
| // Message must be an object with "jsonrpc":"2.0". |
| auto *Object = Message.asObject(); |
| if (!Object || Object->getString("jsonrpc") != Optional<StringRef>("2.0")) |
| return false; |
| // ID may be any JSON value. If absent, this is a notification. |
| llvm::Optional<json::Expr> ID; |
| if (auto *I = Object->get("id")) |
| ID = std::move(*I); |
| // Method must be given. |
| auto Method = Object->getString("method"); |
| if (!Method) |
| return false; |
| // Params should be given, use null if not. |
| json::Expr Params = nullptr; |
| if (auto *P = Object->get("params")) |
| Params = std::move(*P); |
| |
| auto I = Handlers.find(*Method); |
| auto &Handler = I != Handlers.end() ? I->second : UnknownHandler; |
| |
| // Create a Context that contains request information. |
| WithContextValue WithRequestOut(RequestOut, &Out); |
| llvm::Optional<WithContextValue> WithID; |
| if (ID) |
| WithID.emplace(RequestID, *ID); |
| |
| // Create a tracing Span covering the whole request lifetime. |
| trace::Span Tracer(*Method); |
| if (ID) |
| SPAN_ATTACH(Tracer, "ID", *ID); |
| SPAN_ATTACH(Tracer, "Params", Params); |
| |
| // Stash a reference to the span args, so later calls can add metadata. |
| WithContext WithRequestSpan(RequestSpan::stash(Tracer)); |
| Handler(std::move(Params)); |
| return true; |
| } |
| |
| static llvm::Optional<std::string> readStandardMessage(std::istream &In, |
| JSONOutput &Out) { |
| // A Language Server Protocol message starts with a set of HTTP headers, |
| // delimited by \r\n, and terminated by an empty line (\r\n). |
| unsigned long long ContentLength = 0; |
| while (In.good()) { |
| std::string Line; |
| std::getline(In, Line); |
| if (!In.good() && errno == EINTR) { |
| In.clear(); |
| continue; |
| } |
| |
| Out.mirrorInput(Line); |
| // Mirror '\n' that gets consumed by std::getline, but is not included in |
| // the resulting Line. |
| // Note that '\r' is part of Line, so we don't need to mirror it |
| // separately. |
| if (!In.eof()) |
| Out.mirrorInput("\n"); |
| |
| llvm::StringRef LineRef(Line); |
| |
| // We allow comments in headers. Technically this isn't part |
| // of the LSP specification, but makes writing tests easier. |
| if (LineRef.startswith("#")) |
| continue; |
| |
| // Content-Type is a specified header, but does nothing. |
| // Content-Length is a mandatory header. It specifies the length of the |
| // following JSON. |
| // It is unspecified what sequence headers must be supplied in, so we |
| // allow any sequence. |
| // The end of headers is signified by an empty line. |
| if (LineRef.consume_front("Content-Length: ")) { |
| if (ContentLength != 0) { |
| log("Warning: Duplicate Content-Length header received. " |
| "The previous value for this message (" + |
| llvm::Twine(ContentLength) + ") was ignored.\n"); |
| } |
| |
| llvm::getAsUnsignedInteger(LineRef.trim(), 0, ContentLength); |
| continue; |
| } else if (!LineRef.trim().empty()) { |
| // It's another header, ignore it. |
| continue; |
| } else { |
| // An empty line indicates the end of headers. |
| // Go ahead and read the JSON. |
| break; |
| } |
| } |
| |
| // Guard against large messages. This is usually a bug in the client code |
| // and we don't want to crash downstream because of it. |
| if (ContentLength > 1 << 30) { // 1024M |
| In.ignore(ContentLength); |
| log("Skipped overly large message of " + Twine(ContentLength) + |
| " bytes.\n"); |
| return llvm::None; |
| } |
| |
| if (ContentLength > 0) { |
| std::string JSON(ContentLength, '\0'); |
| In.read(&JSON[0], ContentLength); |
| Out.mirrorInput(StringRef(JSON.data(), In.gcount())); |
| |
| // If the stream is aborted before we read ContentLength bytes, In |
| // will have eofbit and failbit set. |
| if (!In) { |
| log("Input was aborted. Read only " + llvm::Twine(In.gcount()) + |
| " bytes of expected " + llvm::Twine(ContentLength) + ".\n"); |
| return llvm::None; |
| } |
| return std::move(JSON); |
| } else { |
| log("Warning: Missing Content-Length header, or message has zero " |
| "length.\n"); |
| return llvm::None; |
| } |
| } |
| |
| // For lit tests we support a simplified syntax: |
| // - messages are delimited by '---' on a line by itself |
| // - lines starting with # are ignored. |
| // This is a testing path, so favor simplicity over performance here. |
| static llvm::Optional<std::string> readDelimitedMessage(std::istream &In, |
| JSONOutput &Out) { |
| std::string JSON; |
| std::string Line; |
| while (std::getline(In, Line)) { |
| if (!In.eof()) // getline() consumed the newline. |
| Line.push_back('\n'); |
| auto LineRef = llvm::StringRef(Line).trim(); |
| if (LineRef.startswith("#")) // comment |
| continue; |
| |
| bool IsDelim = LineRef.find_first_not_of('-') == llvm::StringRef::npos; |
| if (!IsDelim) // Line is part of a JSON message. |
| JSON += Line; |
| if (IsDelim || In.eof()) { |
| Out.mirrorInput( |
| llvm::formatv("Content-Length: {0}\r\n\r\n{1}", JSON.size(), JSON)); |
| return std::move(JSON); |
| } |
| } |
| |
| if (In.bad()) { |
| log("Input error while reading message!"); |
| return llvm::None; |
| } else { |
| log("Input message terminated by EOF"); |
| return std::move(JSON); |
| } |
| } |
| |
| void clangd::runLanguageServerLoop(std::istream &In, JSONOutput &Out, |
| JSONStreamStyle InputStyle, |
| JSONRPCDispatcher &Dispatcher, |
| bool &IsDone) { |
| auto &ReadMessage = |
| (InputStyle == Delimited) ? readDelimitedMessage : readStandardMessage; |
| while (In.good()) { |
| if (auto JSON = ReadMessage(In, Out)) { |
| if (auto Doc = json::parse(*JSON)) { |
| // Log the formatted message. |
| log(llvm::formatv(Out.Pretty ? "<-- {0:2}\n" : "<-- {0}\n", *Doc)); |
| // Finally, execute the action for this JSON message. |
| if (!Dispatcher.call(*Doc, Out)) |
| log("JSON dispatch failed!\n"); |
| } else { |
| // Parse error. Log the raw message. |
| log(llvm::formatv("<-- {0}\n" , *JSON)); |
| log(llvm::Twine("JSON parse error: ") + |
| llvm::toString(Doc.takeError()) + "\n"); |
| } |
| } |
| // If we're done, exit the loop. |
| if (IsDone) |
| break; |
| } |
| } |