From de55f647ff07469afd22628424ffc289cdc88d94 Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Sat, 3 Oct 2009 16:30:22 +0000
Subject: [PATCH] Ignore No-op casts when evaluating lvalue expressions. Fixes
 PR5122.

llvm-svn: 83267
---
 clang/lib/AST/ExprConstant.cpp       | 10 ++++++++++
 clang/test/CodeGenCXX/references.cpp |  5 +++++
 2 files changed, 15 insertions(+)

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 2aefae6fd741..94d22998ebbe 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -180,6 +180,16 @@ public:
     { return Visit(E->getSubExpr()); }
   APValue VisitChooseExpr(const ChooseExpr *E)
     { return Visit(E->getChosenSubExpr(Info.Ctx)); }
+
+  APValue VisitCastExpr(CastExpr *E) {
+    switch (E->getCastKind()) {
+    default:
+      return APValue();
+
+    case CastExpr::CK_NoOp:
+      return Visit(E->getSubExpr());
+    }
+  }
   // FIXME: Missing: __real__, __imag__
 };
 } // end anonymous namespace
diff --git a/clang/test/CodeGenCXX/references.cpp b/clang/test/CodeGenCXX/references.cpp
index 6f4c1032efab..c235521d43b1 100644
--- a/clang/test/CodeGenCXX/references.cpp
+++ b/clang/test/CodeGenCXX/references.cpp
@@ -95,3 +95,8 @@ struct A {
 void f(A* a) {
   int b = a->b();
 }
+
+// PR5122
+void *foo = 0;
+void * const & kFoo = foo;
+