Index: clang-tidy/ClangTidy.cpp
===================================================================
--- clang-tidy/ClangTidy.cpp
+++ clang-tidy/ClangTidy.cpp
@@ -210,6 +210,7 @@
   // modify Compiler.
   Context.setSourceManager(&Compiler.getSourceManager());
   Context.setCurrentFile(File);
+  Context.setASTContext(&Compiler.getASTContext());
 
   std::vector<std::unique_ptr<ClangTidyCheck>> Checks;
   ChecksFilter &Filter = Context.getChecksFilter();
Index: clang-tidy/ClangTidyDiagnosticConsumer.h
===================================================================
--- clang-tidy/ClangTidyDiagnosticConsumer.h
+++ clang-tidy/ClangTidyDiagnosticConsumer.h
@@ -19,6 +19,7 @@
 
 namespace clang {
 
+class ASTContext;
 class CompilerInstance;
 namespace ast_matchers {
 class MatchFinder;
@@ -136,6 +137,9 @@
   /// \brief Should be called when starting to process new translation unit.
   void setCurrentFile(StringRef File);
 
+  /// \brief Sets ASTContext for the current translation unit.
+  void setASTContext(ASTContext *Context);
+
   /// \brief Returns the name of the clang-tidy check which produced this
   /// diagnostic ID.
   StringRef getCheckName(unsigned DiagnosticID) const;
Index: clang-tidy/ClangTidyDiagnosticConsumer.cpp
===================================================================
--- clang-tidy/ClangTidyDiagnosticConsumer.cpp
+++ clang-tidy/ClangTidyDiagnosticConsumer.cpp
@@ -18,6 +18,7 @@
 
 #include "ClangTidyDiagnosticConsumer.h"
 #include "ClangTidyOptions.h"
+#include "clang/AST/ASTDiagnostic.h"
 #include "clang/Basic/DiagnosticOptions.h"
 #include "clang/Frontend/DiagnosticRenderer.h"
 #include "llvm/ADT/SmallString.h"
@@ -204,6 +205,10 @@
   CheckFilter.reset(new ChecksFilter(getOptions().Checks));
 }
 
+void ClangTidyContext::setASTContext(ASTContext *Context) {
+  DiagEngine->SetArgToStringFn(&FormatASTNodeDiagnosticArgument, Context);
+}
+
 const ClangTidyGlobalOptions &ClangTidyContext::getGlobalOptions() const {
   return OptionsProvider->getGlobalOptions();
 }