Index: cfe/trunk/include/clang/AST/RecursiveASTVisitor.h
===================================================================
--- cfe/trunk/include/clang/AST/RecursiveASTVisitor.h
+++ cfe/trunk/include/clang/AST/RecursiveASTVisitor.h
@@ -2308,19 +2308,30 @@
   return true;
 }
 
-// This method is called once for each pair of syntactic and semantic
-// InitListExpr, and it traverses the subtrees defined by the two forms. This
-// may cause some of the children to be visited twice, if they appear both in
-// the syntactic and the semantic form.
+// If shouldVisitImplicitCode() returns false, this method traverses only the
+// syntactic form of InitListExpr.
+// If shouldVisitImplicitCode() return true, this method is called once for
+// each pair of syntactic and semantic InitListExpr, and it traverses the
+// subtrees defined by the two forms. This may cause some of the children to be
+// visited twice, if they appear both in the syntactic and the semantic form.
 //
 // There is no guarantee about which form \p S takes when this method is called.
 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseInitListExpr(
     InitListExpr *S, DataRecursionQueue *Queue) {
+  if (S->isSemanticForm() && S->isSyntacticForm()) {
+    // `S` does not have alternative forms, traverse only once.
+    TRY_TO(TraverseSynOrSemInitListExpr(S, Queue));
+    return true;
+  }
   TRY_TO(TraverseSynOrSemInitListExpr(
       S->isSemanticForm() ? S->getSyntacticForm() : S, Queue));
-  TRY_TO(TraverseSynOrSemInitListExpr(
-      S->isSemanticForm() ? S : S->getSemanticForm(), Queue));
+  if (getDerived().shouldVisitImplicitCode()) {
+    // Only visit the semantic form if the clients are interested in implicit
+    // compiler-generated.
+    TRY_TO(TraverseSynOrSemInitListExpr(
+        S->isSemanticForm() ? S : S->getSemanticForm(), Queue));
+  }
   return true;
 }
 
Index: cfe/trunk/unittests/Tooling/RecursiveASTVisitorTests/InitListExprPreOrder.cpp
===================================================================
--- cfe/trunk/unittests/Tooling/RecursiveASTVisitorTests/InitListExprPreOrder.cpp
+++ cfe/trunk/unittests/Tooling/RecursiveASTVisitorTests/InitListExprPreOrder.cpp
@@ -17,14 +17,22 @@
 class InitListExprPreOrderVisitor
     : public ExpectedLocationVisitor<InitListExprPreOrderVisitor> {
 public:
+  InitListExprPreOrderVisitor(bool VisitImplicitCode)
+      : VisitImplicitCode(VisitImplicitCode) {}
+
+  bool shouldVisitImplicitCode() const { return VisitImplicitCode; }
+
   bool VisitInitListExpr(InitListExpr *ILE) {
     Match(ILE->isSemanticForm() ? "semantic" : "syntactic", ILE->getBeginLoc());
     return true;
   }
+
+private:
+  bool VisitImplicitCode;
 };
 
 TEST(RecursiveASTVisitor, InitListExprIsPreOrderVisitedTwice) {
-  InitListExprPreOrderVisitor Visitor;
+  InitListExprPreOrderVisitor Visitor(/*VisitImplicitCode=*/true);
   Visitor.ExpectMatch("syntactic", 2, 21);
   Visitor.ExpectMatch("semantic", 2, 21);
   EXPECT_TRUE(Visitor.runOver("struct S { int x; };\n"
@@ -32,4 +40,13 @@
                               InitListExprPreOrderVisitor::Lang_C));
 }
 
+TEST(RecursiveASTVisitor, InitListExprVisitedOnceWhenNoImplicit) {
+  InitListExprPreOrderVisitor Visitor(/*VisitImplicitCode=*/false);
+  Visitor.ExpectMatch("syntactic", 2, 21);
+  Visitor.DisallowMatch("semantic", 2, 21);
+  EXPECT_TRUE(Visitor.runOver("struct S { int x; };\n"
+                              "static struct S s = {.x = 0};\n",
+                              InitListExprPreOrderVisitor::Lang_C));
+}
+
 } // end anonymous namespace