Index: cfe/trunk/include/clang/Tooling/Refactoring/Transformer.h
===================================================================
--- cfe/trunk/include/clang/Tooling/Refactoring/Transformer.h
+++ cfe/trunk/include/clang/Tooling/Refactoring/Transformer.h
@@ -125,14 +125,16 @@
 
 /// Convenience function for constructing a simple \c RewriteRule.
 RewriteRule makeRule(ast_matchers::internal::DynTypedMatcher M,
-                     SmallVector<ASTEdit, 1> Edits);
+                     SmallVector<ASTEdit, 1> Edits,
+                     TextGenerator Explanation = nullptr);
 
 /// Convenience overload of \c makeRule for common case of only one edit.
 inline RewriteRule makeRule(ast_matchers::internal::DynTypedMatcher M,
-                            ASTEdit Edit) {
+                            ASTEdit Edit,
+                            TextGenerator Explanation = nullptr) {
   SmallVector<ASTEdit, 1> Edits;
   Edits.emplace_back(std::move(Edit));
-  return makeRule(std::move(M), std::move(Edits));
+  return makeRule(std::move(M), std::move(Edits), std::move(Explanation));
 }
 
 /// Applies the first rule whose pattern matches; other rules are ignored.
Index: cfe/trunk/lib/Tooling/Refactoring/Transformer.cpp
===================================================================
--- cfe/trunk/lib/Tooling/Refactoring/Transformer.cpp
+++ cfe/trunk/lib/Tooling/Refactoring/Transformer.cpp
@@ -96,10 +96,10 @@
   return E;
 }
 
-RewriteRule tooling::makeRule(DynTypedMatcher M,
-                              SmallVector<ASTEdit, 1> Edits) {
-  return RewriteRule{
-      {RewriteRule::Case{std::move(M), std::move(Edits), nullptr}}};
+RewriteRule tooling::makeRule(DynTypedMatcher M, SmallVector<ASTEdit, 1> Edits,
+                              TextGenerator Explanation) {
+  return RewriteRule{{RewriteRule::Case{std::move(M), std::move(Edits),
+                                        std::move(Explanation)}}};
 }
 
 // Determines whether A is a base type of B in the class hierarchy, including
Index: cfe/trunk/unittests/Tooling/TransformerTest.cpp
===================================================================
--- cfe/trunk/unittests/Tooling/TransformerTest.cpp
+++ cfe/trunk/unittests/Tooling/TransformerTest.cpp
@@ -147,8 +147,7 @@
                                   on(expr(hasType(isOrPointsTo(StringType)))
                                          .bind(StringExpr)),
                                   callee(cxxMethodDecl(hasName("c_str")))))),
-      change(text("REPLACED")));
-  R.Cases[0].Explanation = text("Use size() method directly on string.");
+      change(text("REPLACED")), text("Use size() method directly on string."));
   return R;
 }