From c446d1816f46a4b6d2337102dfc001f55fc18211 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Wed, 5 May 2010 20:15:55 +0000
Subject: [PATCH] When we emit a non-constant initializer for a global variable
 of reference type, make sure that the initializer we build is the of the
 appropriate type for the *reference*, not for the thing that it refers to.
 Fixes PR7050.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103115 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CodeGenModule.cpp     |  6 ++++--
 test/CodeGenCXX/static-init-3.cpp | 28 ++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)
 create mode 100644 test/CodeGenCXX/static-init-3.cpp

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index cc90a2855d..9c84bcec05 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1101,10 +1101,12 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
     assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
     Init = EmitNullConstant(D->getType());
   } else {
-    Init = EmitConstantExpr(InitExpr, D->getType());
-
+    Init = EmitConstantExpr(InitExpr, D->getType());       
     if (!Init) {
       QualType T = InitExpr->getType();
+      if (D->getType()->isReferenceType())
+        T = D->getType();
+      
       if (getLangOptions().CPlusPlus) {
         EmitCXXGlobalVarDeclInitFunc(D);
         Init = EmitNullConstant(T);
diff --git a/test/CodeGenCXX/static-init-3.cpp b/test/CodeGenCXX/static-init-3.cpp
new file mode 100644
index 0000000000..5bf76a6170
--- /dev/null
+++ b/test/CodeGenCXX/static-init-3.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-apple-darwin10.0.0 -o - %s | FileCheck %s
+
+// PR7050
+template<class T> struct X0 : public T { };
+
+template <class T>
+struct X1
+{
+     static T & instance;
+    // include this to provoke instantiation at pre-execution time
+    static void use(T const &) {}
+     static T & get() {
+        static X0<T> t;
+        use(instance);
+        return static_cast<T &>(t);
+    }
+};
+
+// CHECK: @_ZN2X1I2X2I1BEE8instanceE = weak global %struct.X0* null, align 8
+// CHECJ: @_ZN2X1I2X2I1AEE8instanceE = weak global %struct.X0* null, align 8
+template<class T> T & X1<T>::instance = X1<T>::get();
+
+class A { };
+class B : public A { };
+
+template<typename T> struct X2 {};
+X2< B > bg = X1< X2< B > >::get(); 
+X2< A > ag = X1< X2< A > >::get();
-- 
2.40.0