Index: clang-tools-extra/trunk/clangd/ClangdLSPServer.h
===================================================================
--- clang-tools-extra/trunk/clangd/ClangdLSPServer.h
+++ clang-tools-extra/trunk/clangd/ClangdLSPServer.h
@@ -50,7 +50,7 @@
 private:
   // Implement DiagnosticsConsumer.
   virtual void
-  onDiagnosticsReady(PathRef File,
+  onDiagnosticsReady(const Context &Ctx, PathRef File,
                      Tagged<std::vector<DiagWithFixIts>> Diagnostics) override;
 
   // Implement ProtocolCallbacks.
Index: clang-tools-extra/trunk/clangd/ClangdLSPServer.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/ClangdLSPServer.cpp
+++ clang-tools-extra/trunk/clangd/ClangdLSPServer.cpp
@@ -325,7 +325,8 @@
 }
 
 void ClangdLSPServer::onDiagnosticsReady(
-    PathRef File, Tagged<std::vector<DiagWithFixIts>> Diagnostics) {
+    const Context &Ctx, PathRef File,
+    Tagged<std::vector<DiagWithFixIts>> Diagnostics) {
   json::ary DiagnosticsJSON;
 
   DiagnosticToReplacementMap LocalFixIts; // Temporary storage
Index: clang-tools-extra/trunk/clangd/ClangdServer.h
===================================================================
--- clang-tools-extra/trunk/clangd/ClangdServer.h
+++ clang-tools-extra/trunk/clangd/ClangdServer.h
@@ -72,7 +72,7 @@
 
   /// Called by ClangdServer when \p Diagnostics for \p File are ready.
   virtual void
-  onDiagnosticsReady(PathRef File,
+  onDiagnosticsReady(const Context &Ctx, PathRef File,
                      Tagged<std::vector<DiagWithFixIts>> Diagnostics) = 0;
 };
 
Index: clang-tools-extra/trunk/clangd/ClangdServer.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/ClangdServer.cpp
+++ clang-tools-extra/trunk/clangd/ClangdServer.cpp
@@ -586,7 +586,7 @@
       return;
     LastReportedDiagsVersion = Version;
 
-    DiagConsumer.onDiagnosticsReady(FileStr,
+    DiagConsumer.onDiagnosticsReady(Ctx, FileStr,
                                     make_tagged(std::move(*Diags), Tag));
   };
 
Index: clang-tools-extra/trunk/unittests/clangd/ClangdTests.cpp
===================================================================
--- clang-tools-extra/trunk/unittests/clangd/ClangdTests.cpp
+++ clang-tools-extra/trunk/unittests/clangd/ClangdTests.cpp
@@ -49,7 +49,7 @@
 class ErrorCheckingDiagConsumer : public DiagnosticsConsumer {
 public:
   void
-  onDiagnosticsReady(PathRef File,
+  onDiagnosticsReady(const Context &Ctx, PathRef File,
                      Tagged<std::vector<DiagWithFixIts>> Diagnostics) override {
     bool HadError = diagsContainErrors(Diagnostics.Value);
 
@@ -470,7 +470,7 @@
     TestDiagConsumer() : Stats(FilesCount, FileStat()) {}
 
     void onDiagnosticsReady(
-        PathRef File,
+        const Context &Ctx, PathRef File,
         Tagged<std::vector<DiagWithFixIts>> Diagnostics) override {
       StringRef FileIndexStr = llvm::sys::path::stem(File);
       ASSERT_TRUE(FileIndexStr.consume_front("Foo"));
@@ -758,7 +758,7 @@
         : StartSecondReparse(std::move(StartSecondReparse)) {}
 
     void onDiagnosticsReady(
-        PathRef File,
+        const Context &Ctx, PathRef File,
         Tagged<std::vector<DiagWithFixIts>> Diagnostics) override {
 
       std::unique_lock<std::mutex> Lock(Mutex, std::try_to_lock_t());
Index: clang-tools-extra/trunk/unittests/clangd/CodeCompleteTests.cpp
===================================================================
--- clang-tools-extra/trunk/unittests/clangd/CodeCompleteTests.cpp
+++ clang-tools-extra/trunk/unittests/clangd/CodeCompleteTests.cpp
@@ -59,8 +59,10 @@
 using ::testing::Not;
 
 class IgnoreDiagnostics : public DiagnosticsConsumer {
-  void onDiagnosticsReady(
-      PathRef File, Tagged<std::vector<DiagWithFixIts>> Diagnostics) override {}
+  void
+  onDiagnosticsReady(const Context &Ctx, PathRef File,
+                     Tagged<std::vector<DiagWithFixIts>> Diagnostics) override {
+  }
 };
 
 // GMock helpers for matching completion items.