Index: include/clang/Tooling/Core/Diagnostic.h
===================================================================
--- include/clang/Tooling/Core/Diagnostic.h
+++ include/clang/Tooling/Core/Diagnostic.h
@@ -47,6 +47,18 @@
   llvm::StringMap<Replacements> Fix;
 };
 
+/// Represents a single source ranges to be associated with a diagnostic.
+struct DiagnosticAssociatedRange {
+  DiagnosticAssociatedRange() = default;
+
+  DiagnosticAssociatedRange(const SourceManager &Sources,
+                            CharSourceRange Range);
+
+  std::string FilePath;
+  unsigned FileOffset;
+  unsigned Length;
+};
+
 /// Represents the diagnostic with the level of severity and possible
 /// fixes to be applied.
 struct Diagnostic {
@@ -62,7 +74,8 @@
 
   Diagnostic(llvm::StringRef DiagnosticName, const DiagnosticMessage &Message,
              const SmallVector<DiagnosticMessage, 1> &Notes, Level DiagLevel,
-             llvm::StringRef BuildDirectory);
+             llvm::StringRef BuildDirectory,
+             const SmallVector<DiagnosticAssociatedRange, 1> &Ranges);
 
   /// Name identifying the Diagnostic.
   std::string DiagnosticName;
@@ -84,6 +97,10 @@
   ///
   /// Note: it is empty in unittest.
   std::string BuildDirectory;
+
+  /// Extra source ranges associated with the diagnostic (in addition to the
+  /// location of the Message above).
+  SmallVector<DiagnosticAssociatedRange, 1> Ranges;
 };
 
 /// Collection of Diagnostics generated from a single translation unit.
Index: include/clang/Tooling/DiagnosticsYaml.h
===================================================================
--- include/clang/Tooling/DiagnosticsYaml.h
+++ include/clang/Tooling/DiagnosticsYaml.h
@@ -20,12 +20,21 @@
 #include "llvm/Support/YAMLTraits.h"
 #include <string>
 
+LLVM_YAML_IS_SEQUENCE_VECTOR(clang::tooling::DiagnosticAssociatedRange)
 LLVM_YAML_IS_SEQUENCE_VECTOR(clang::tooling::Diagnostic)
 LLVM_YAML_IS_SEQUENCE_VECTOR(clang::tooling::DiagnosticMessage)
 
 namespace llvm {
 namespace yaml {
 
+template <> struct MappingTraits<clang::tooling::DiagnosticAssociatedRange> {
+  static void mapping(IO &Io, clang::tooling::DiagnosticAssociatedRange &R) {
+    Io.mapRequired("FilePath", R.FilePath);
+    Io.mapRequired("FileOffset", R.FileOffset);
+    Io.mapRequired("Length", R.Length);
+  }
+};
+
 template <> struct MappingTraits<clang::tooling::DiagnosticMessage> {
   static void mapping(IO &Io, clang::tooling::DiagnosticMessage &M) {
     Io.mapRequired("Message", M.Message);
@@ -58,11 +67,12 @@
 
     NormalizedDiagnostic(const IO &, const clang::tooling::Diagnostic &D)
         : DiagnosticName(D.DiagnosticName), Message(D.Message), Notes(D.Notes),
-          DiagLevel(D.DiagLevel), BuildDirectory(D.BuildDirectory) {}
+          DiagLevel(D.DiagLevel), BuildDirectory(D.BuildDirectory),
+          Ranges(D.Ranges) {}
 
     clang::tooling::Diagnostic denormalize(const IO &) {
       return clang::tooling::Diagnostic(DiagnosticName, Message, Notes,
-                                        DiagLevel, BuildDirectory);
+                                        DiagLevel, BuildDirectory, Ranges);
     }
 
     std::string DiagnosticName;
@@ -71,6 +81,7 @@
     SmallVector<clang::tooling::DiagnosticMessage, 1> Notes;
     clang::tooling::Diagnostic::Level DiagLevel;
     std::string BuildDirectory;
+    SmallVector<clang::tooling::DiagnosticAssociatedRange, 1> Ranges;
   };
 
   static void mapping(IO &Io, clang::tooling::Diagnostic &D) {
@@ -79,6 +90,7 @@
     Io.mapRequired("DiagnosticName", Keys->DiagnosticName);
     Io.mapRequired("DiagnosticMessage", Keys->Message);
     Io.mapOptional("Notes", Keys->Notes);
+    Io.mapOptional("Ranges", Keys->Ranges);
 
     // FIXME: Export properly all the different fields.
   }
Index: lib/Tooling/Core/Diagnostic.cpp
===================================================================
--- lib/Tooling/Core/Diagnostic.cpp
+++ lib/Tooling/Core/Diagnostic.cpp
@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Tooling/Core/Diagnostic.h"
+#include "third_party/llvm/llvm-project/clang/include/clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
 #include "llvm/ADT/STLExtras.h"
 
@@ -34,6 +35,16 @@
     FileOffset = Sources.getFileOffset(Loc);
 }
 
+DiagnosticAssociatedRange::DiagnosticAssociatedRange(
+    const SourceManager &Sources, CharSourceRange Range)
+    : FileOffset(0), Length(0) {
+  FilePath = std::string(Sources.getFilename(Range.getBegin()));
+  if (!FilePath.empty()) {
+    FileOffset = Sources.getFileOffset(Range.getBegin());
+    Length = Sources.getFileOffset(Range.getEnd()) - FileOffset;
+  }
+}
+
 Diagnostic::Diagnostic(llvm::StringRef DiagnosticName,
                        Diagnostic::Level DiagLevel, StringRef BuildDirectory)
     : DiagnosticName(DiagnosticName), DiagLevel(DiagLevel),
@@ -42,9 +53,10 @@
 Diagnostic::Diagnostic(llvm::StringRef DiagnosticName,
                        const DiagnosticMessage &Message,
                        const SmallVector<DiagnosticMessage, 1> &Notes,
-                       Level DiagLevel, llvm::StringRef BuildDirectory)
+                       Level DiagLevel, llvm::StringRef BuildDirectory,
+                       const SmallVector<DiagnosticAssociatedRange, 1> &Ranges)
     : DiagnosticName(DiagnosticName), Message(Message), Notes(Notes),
-      DiagLevel(DiagLevel), BuildDirectory(BuildDirectory) {}
+      DiagLevel(DiagLevel), BuildDirectory(BuildDirectory), Ranges(Ranges) {}
 
 const llvm::StringMap<Replacements> *selectFirstFix(const Diagnostic& D) {
    if (!D.Message.Fix.empty())