Index: clang-tools-extra/trunk/clangd/ClangdLSPServer.h
===================================================================
--- clang-tools-extra/trunk/clangd/ClangdLSPServer.h
+++ clang-tools-extra/trunk/clangd/ClangdLSPServer.h
@@ -39,7 +39,9 @@
   /// opened in binary mode. Output will be written using Out variable passed to
   /// class constructor. This method must not be executed more than once for
   /// each instance of ClangdLSPServer.
-  void run(std::istream &In);
+  ///
+  /// \return Wether we received a 'shutdown' request before an 'exit' request
+  bool run(std::istream &In);
 
 private:
   // Implement DiagnosticsConsumer.
@@ -50,6 +52,7 @@
   // Implement ProtocolCallbacks.
   void onInitialize(Ctx C, InitializeParams &Params) override;
   void onShutdown(Ctx C, ShutdownParams &Params) override;
+  void onExit(Ctx C, ExitParams &Params) override;
   void onDocumentDidOpen(Ctx C, DidOpenTextDocumentParams &Params) override;
   void onDocumentDidChange(Ctx C, DidChangeTextDocumentParams &Params) override;
   void onDocumentDidClose(Ctx C, DidCloseTextDocumentParams &Params) override;
@@ -79,6 +82,10 @@
   JSONOutput &Out;
   /// Used to indicate that the 'shutdown' request was received from the
   /// Language Server client.
+  bool ShutdownRequestReceived = false;
+
+  /// Used to indicate that the 'exit' notification was received from the
+  /// Language Server client.
   /// It's used to break out of the LSP parsing loop.
   bool IsDone = false;
 
Index: clang-tools-extra/trunk/clangd/ClangdLSPServer.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/ClangdLSPServer.cpp
+++ clang-tools-extra/trunk/clangd/ClangdLSPServer.cpp
@@ -56,9 +56,13 @@
 }
 
 void ClangdLSPServer::onShutdown(Ctx C, ShutdownParams &Params) {
-  IsDone = true;
+  // Do essentially nothing, just say we're ready to exit.
+  ShutdownRequestReceived = true;
+  C.reply("null");
 }
 
+void ClangdLSPServer::onExit(Ctx C, ExitParams &Params) { IsDone = true; }
+
 void ClangdLSPServer::onDocumentDidOpen(Ctx C,
                                         DidOpenTextDocumentParams &Params) {
   if (Params.metadata && !Params.metadata->extraFlags.empty())
@@ -197,7 +201,7 @@
                  /*EnableSnippetsAndCodePatterns=*/SnippetCompletions),
              /*Logger=*/Out, ResourceDir) {}
 
-void ClangdLSPServer::run(std::istream &In) {
+bool ClangdLSPServer::run(std::istream &In) {
   assert(!IsDone && "Run was called before");
 
   // Set up JSONRPCDispatcher.
@@ -213,6 +217,8 @@
   // Make sure IsDone is set to true after this method exits to ensure assertion
   // at the start of the method fires if it's ever executed again.
   IsDone = true;
+
+  return ShutdownRequestReceived;
 }
 
 std::vector<clang::tooling::Replacement>
Index: clang-tools-extra/trunk/clangd/Protocol.h
===================================================================
--- clang-tools-extra/trunk/clangd/Protocol.h
+++ clang-tools-extra/trunk/clangd/Protocol.h
@@ -173,6 +173,7 @@
   }
 };
 using ShutdownParams = NoParams;
+using ExitParams = NoParams;
 
 struct InitializeParams {
   /// The process Id of the parent process that started
Index: clang-tools-extra/trunk/clangd/ProtocolHandlers.h
===================================================================
--- clang-tools-extra/trunk/clangd/ProtocolHandlers.h
+++ clang-tools-extra/trunk/clangd/ProtocolHandlers.h
@@ -34,6 +34,7 @@
 
   virtual void onInitialize(Ctx C, InitializeParams &Params) = 0;
   virtual void onShutdown(Ctx C, ShutdownParams &Params) = 0;
+  virtual void onExit(Ctx C, ExitParams &Params) = 0;
   virtual void onDocumentDidOpen(Ctx C, DidOpenTextDocumentParams &Params) = 0;
   virtual void onDocumentDidChange(Ctx C,
                                    DidChangeTextDocumentParams &Params) = 0;
Index: clang-tools-extra/trunk/clangd/ProtocolHandlers.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/ProtocolHandlers.cpp
+++ clang-tools-extra/trunk/clangd/ProtocolHandlers.cpp
@@ -52,6 +52,7 @@
 
   Register("initialize", &ProtocolCallbacks::onInitialize);
   Register("shutdown", &ProtocolCallbacks::onShutdown);
+  Register("exit", &ProtocolCallbacks::onExit);
   Register("textDocument/didOpen", &ProtocolCallbacks::onDocumentDidOpen);
   Register("textDocument/didClose", &ProtocolCallbacks::onDocumentDidClose);
   Register("textDocument/didChange", &ProtocolCallbacks::onDocumentDidChange);
Index: clang-tools-extra/trunk/clangd/tool/ClangdMain.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/tool/ClangdMain.cpp
+++ clang-tools-extra/trunk/clangd/tool/ClangdMain.cpp
@@ -114,5 +114,7 @@
   /// Initialize and run ClangdLSPServer.
   ClangdLSPServer LSPServer(Out, WorkerThreadsCount, EnableSnippets,
                             ResourceDirRef, CompileCommandsDirPath);
-  LSPServer.run(std::cin);
+
+  constexpr int NoShutdownRequestErrorCode = 1;
+  return LSPServer.run(std::cin) ? 0 : NoShutdownRequestErrorCode;
 }
Index: clang-tools-extra/trunk/test/clangd/authority-less-uri.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/authority-less-uri.test
+++ clang-tools-extra/trunk/test/clangd/authority-less-uri.test
@@ -30,3 +30,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":3,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/completion-priorities.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/completion-priorities.test
+++ clang-tools-extra/trunk/test/clangd/completion-priorities.test
@@ -34,3 +34,7 @@
 Content-Length: 58
 
 {"jsonrpc":"2.0","id":4,"method":"shutdown","params":null}
+# CHECK: {"jsonrpc":"2.0","id":4,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/completion-qualifiers.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/completion-qualifiers.test
+++ clang-tools-extra/trunk/test/clangd/completion-qualifiers.test
@@ -16,3 +16,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":4,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":4,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/completion-snippet.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/completion-snippet.test
+++ clang-tools-extra/trunk/test/clangd/completion-snippet.test
@@ -52,3 +52,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":4,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":4,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/completion.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/completion.test
+++ clang-tools-extra/trunk/test/clangd/completion.test
@@ -52,3 +52,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":4,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":4,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/definitions.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/definitions.test
+++ clang-tools-extra/trunk/test/clangd/definitions.test
@@ -166,3 +166,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":3,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/diagnostics-preamble.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/diagnostics-preamble.test
+++ clang-tools-extra/trunk/test/clangd/diagnostics-preamble.test
@@ -13,3 +13,7 @@
 Content-Length: 58
 
 {"jsonrpc":"2.0","id":2,"method":"shutdown","params":null}
+# CHECK: {"jsonrpc":"2.0","id":2,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/diagnostics.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/diagnostics.test
+++ clang-tools-extra/trunk/test/clangd/diagnostics.test
@@ -15,3 +15,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":5,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":5,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/did-change-watch-files.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/did-change-watch-files.test
+++ clang-tools-extra/trunk/test/clangd/did-change-watch-files.test
@@ -59,3 +59,6 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/extra-flags.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/extra-flags.test
+++ clang-tools-extra/trunk/test/clangd/extra-flags.test
@@ -18,5 +18,9 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":5,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":5,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
 
 
Index: clang-tools-extra/trunk/test/clangd/fixits.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/fixits.test
+++ clang-tools-extra/trunk/test/clangd/fixits.test
@@ -26,3 +26,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":3,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/formatting.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/formatting.test
+++ clang-tools-extra/trunk/test/clangd/formatting.test
@@ -65,3 +65,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":6,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":6,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/initialize-params-invalid.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/initialize-params-invalid.test
+++ clang-tools-extra/trunk/test/clangd/initialize-params-invalid.test
@@ -20,3 +20,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":3,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/initialize-params.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/initialize-params.test
+++ clang-tools-extra/trunk/test/clangd/initialize-params.test
@@ -20,3 +20,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":3,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/input-mirror.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/input-mirror.test
+++ clang-tools-extra/trunk/test/clangd/input-mirror.test
@@ -152,3 +152,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":3,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":3,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/protocol.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/protocol.test
+++ clang-tools-extra/trunk/test/clangd/protocol.test
@@ -1,8 +1,10 @@
-# RUN: clangd -run-synchronously < %s | FileCheck %s
-# RUN: clangd -run-synchronously < %s 2>&1 | FileCheck -check-prefix=STDERR %s
+# RUN: not clangd -run-synchronously < %s | FileCheck %s
+# RUN: not clangd -run-synchronously < %s 2>&1 | FileCheck -check-prefix=STDERR %s
 # vim: fileformat=dos
 # It is absolutely vital that this file has CRLF line endings.
 #
+# Note that we invert the test because we intent to let clangd exit prematurely.
+#
 # Test protocol parsing
 Content-Length: 125
 Content-Type: application/vscode-jsonrpc; charset-utf-8
Index: clang-tools-extra/trunk/test/clangd/shutdown-with-exit.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/shutdown-with-exit.test
+++ clang-tools-extra/trunk/test/clangd/shutdown-with-exit.test
@@ -0,0 +1,9 @@
+# RUN: clangd -run-synchronously < %s
+# vim: fileformat=dos
+# It is absolutely vital that this file has CRLF line endings.
+Content-Length: 44
+
+{"jsonrpc":"2.0","id":3,"method":"shutdown"}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/shutdown-without-exit.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/shutdown-without-exit.test
+++ clang-tools-extra/trunk/test/clangd/shutdown-without-exit.test
@@ -0,0 +1,6 @@
+# RUN: not clangd -run-synchronously < %s
+# vim: fileformat=dos
+# It is absolutely vital that this file has CRLF line endings.
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/signature-help.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/signature-help.test
+++ clang-tools-extra/trunk/test/clangd/signature-help.test
@@ -40,3 +40,7 @@
 Content-Length: 49
 
 {"jsonrpc":"2.0","id":100000,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":100000,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}
Index: clang-tools-extra/trunk/test/clangd/unsupported-method.test
===================================================================
--- clang-tools-extra/trunk/test/clangd/unsupported-method.test
+++ clang-tools-extra/trunk/test/clangd/unsupported-method.test
@@ -17,3 +17,7 @@
 Content-Length: 44
 
 {"jsonrpc":"2.0","id":2,"method":"shutdown"}
+# CHECK: {"jsonrpc":"2.0","id":2,"result":null}
+Content-Length: 33
+
+{"jsonrpc":"2.0":"method":"exit"}