Index: include/clang/Format/Format.h
===================================================================
--- include/clang/Format/Format.h
+++ include/clang/Format/Format.h
@@ -1685,6 +1685,29 @@
            Standard == R.Standard && TabWidth == R.TabWidth &&
            UseTab == R.UseTab;
   }
+
+  llvm::Optional<FormatStyle> GetLanguageStyle(LanguageKind Language) const;
+  void AddLanguageStyle(const FormatStyle& Style);
+
+ private:
+   // Stores per-language styles. A FormatStyle instance inside has an empty
+   // StyleSet. A FormatStyle instance returned by the Get method has its
+   // StyleSet set to a copy of the originating StyleSet, effectively keeping
+   // the internal representation of that StyleSet alive.
+   //
+   // The memory management and ownership reminds of a birds nest: chicks
+   // leaving the nest take photos of the nest with them.
+   struct FormatStyleSet {
+     typedef std::map<FormatStyle::LanguageKind,
+                      std::unique_ptr<const FormatStyle>>
+         MapType;
+     llvm::Optional<FormatStyle> Get(FormatStyle::LanguageKind Language) const;
+     void Add(FormatStyle Style);
+   private:
+     std::shared_ptr<MapType> Styles;
+   };
+
+   FormatStyleSet StyleSet;
 };
 
 /// \brief Returns a format style complying with the LLVM coding standards:
Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -888,15 +888,24 @@
   // Look for a suitable configuration starting from the end, so we can
   // find the configuration for the specific language first, and the default
   // configuration (which can only be at slot 0) after it.
+  bool LanguageFound = false;
   for (int i = Styles.size() - 1; i >= 0; --i) {
-    if (Styles[i].Language == Language ||
-        Styles[i].Language == FormatStyle::LK_None) {
+    if (!LanguageFound && (Styles[i].Language == Language ||
+                           Styles[i].Language == FormatStyle::LK_None)) {
       *Style = Styles[i];
       Style->Language = Language;
-      return make_error_code(ParseError::Success);
+      LanguageFound = true;
+      break;
+    }
+  }
+  if (!LanguageFound)
+    return make_error_code(ParseError::Unsuitable);
+  for (int i = Styles.size() - 1; i >= 0; --i) {
+    if (Styles[i].Language != FormatStyle::LK_None) {
+      Style->AddLanguageStyle(Styles[i]);
     }
   }
-  return make_error_code(ParseError::Unsuitable);
+  return make_error_code(ParseError::Success);
 }
 
 std::string configurationAsText(const FormatStyle &Style) {
@@ -910,6 +919,34 @@
   return Stream.str();
 }
 
+llvm::Optional<FormatStyle>
+FormatStyle::FormatStyleSet::Get(FormatStyle::LanguageKind Language) const {
+  if (!Styles)
+    return None;
+  auto It = Styles->find(Language);
+  if (It == Styles->end())
+    return None;
+  FormatStyle Style = *It->second;
+  Style.StyleSet = *this;
+  return Style;
+}
+
+void FormatStyle::FormatStyleSet::Add(FormatStyle Style) {
+  Style.StyleSet.Styles.reset();
+  if (!Styles)
+    Styles = std::make_shared<MapType>();
+  (*Styles)[Style.Language].reset(new FormatStyle(Style));
+}
+
+llvm::Optional<FormatStyle>
+FormatStyle::GetLanguageStyle(FormatStyle::LanguageKind Language) const {
+  return StyleSet.Get(Language);
+}
+
+void FormatStyle::AddLanguageStyle(const FormatStyle& Style) {
+  StyleSet.Add(Style);
+}
+
 namespace {
 
 class JavaScriptRequoter : public TokenAnalyzer {