From 86aa0cdfd5aa7b099efbcd612a014d1b5f0ff799 Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Mon, 19 Oct 2009 18:28:22 +0000
Subject: [PATCH] Handle emitting the assignment operator when the lhs is a
 reference. Fixes PR5227.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@84518 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGExpr.cpp         | 10 ++++++++++
 test/CodeGenCXX/references.cpp |  6 ++++++
 2 files changed, 16 insertions(+)

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 6542aa50d2..29ca900ed3 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1367,6 +1367,16 @@ LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
   if (E->getOpcode() != BinaryOperator::Assign)
     return EmitUnsupportedLValue(E, "binary l-value expression");
 
+  if (!hasAggregateLLVMType(E->getType())) {
+    // Emit the LHS as an l-value.
+    LValue LV = EmitLValue(E->getLHS());
+    
+    llvm::Value *RHS = EmitScalarExpr(E->getRHS());
+    EmitStoreOfScalar(RHS, LV.getAddress(), LV.isVolatileQualified(), 
+                      E->getType());
+    return LV;
+  }
+  
   llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
   EmitAggExpr(E, Temp, false);
   // FIXME: Are these qualifiers correct?
diff --git a/test/CodeGenCXX/references.cpp b/test/CodeGenCXX/references.cpp
index 682aab310d..8e0e1cbe84 100644
--- a/test/CodeGenCXX/references.cpp
+++ b/test/CodeGenCXX/references.cpp
@@ -130,3 +130,9 @@ namespace T {
   }
 }
 
+// PR5227.
+namespace PR5227 {
+void f(int &a) {
+  (a = 10) = 20;
+}
+}
-- 
2.50.1