From 391ca9f2c9e9b93fe7196b56f20701cbb6dc0dd7 Mon Sep 17 00:00:00 2001
From: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date: Tue, 9 Apr 2013 01:17:02 +0000
Subject: [PATCH] Mark as referenced the functions from instantiated
 UserDefinedLiterals.

Fixes rdar://13589856

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179078 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/TreeTransform.h                            |  2 ++
 test/SemaCXX/cxx11-user-defined-literals-unused.cpp | 13 +++++++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 test/SemaCXX/cxx11-user-defined-literals-unused.cpp

diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index f68de26cde..835609585e 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -6173,6 +6173,8 @@ TreeTransform<Derived>::TransformCharacterLiteral(CharacterLiteral *E) {
 template<typename Derived>
 ExprResult
 TreeTransform<Derived>::TransformUserDefinedLiteral(UserDefinedLiteral *E) {
+  if (FunctionDecl *FD = E->getDirectCallee())
+    SemaRef.MarkFunctionReferenced(E->getLocStart(), FD);
   return SemaRef.MaybeBindToTemporary(E);
 }
 
diff --git a/test/SemaCXX/cxx11-user-defined-literals-unused.cpp b/test/SemaCXX/cxx11-user-defined-literals-unused.cpp
new file mode 100644
index 0000000000..cd93ffbf21
--- /dev/null
+++ b/test/SemaCXX/cxx11-user-defined-literals-unused.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -std=c++11 -verify %s -Wunused
+
+namespace {
+double operator"" _x(long double value) { return double(value); }
+int operator"" _ii(long double value) { return int(value); } // expected-warning {{not needed and will not be emitted}}
+}
+
+namespace rdar13589856 {
+  template<class T> double value() { return 3.2_x; }
+  template<class T> int valuei() { return 3.2_ii; }
+
+  double get_value() { return value<double>(); }
+}
-- 
2.40.0