Create a temporary if the lvalue is a bitfield. Reported by Eli.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72155 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/AST/Expr.h

@@ -182,6 +182,10 @@ public:
   /// declaration of that bit-field.
   FieldDecl *getBitField();
 
+  const FieldDecl *getBitField() const {
+    return const_cast<Expr*>(this)->getBitField();
+  }
+  
   /// isIntegerConstantExpr - Return true if this expression is a valid integer
   /// constant expression, and, if so, return its value in Result.  If not a
   /// valid i-c-e, return false and fill in Loc (if specified) with the location

lib/CodeGen/CGExpr.cpp

@@ -72,7 +72,7 @@ RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E, llvm::Value *AggLoc,
 
 RValue CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
                                                    QualType DestType) {
-  if (E->isLvalue(getContext()) == Expr::LV_Valid) {
+  if (E->isLvalue(getContext()) == Expr::LV_Valid && !E->getBitField()) {
     // Emit the expr as an lvalue.
     LValue LV = EmitLValue(E);
     return RValue::get(LV.getAddress());

test/CodeGenCXX/references.cpp

@@ -35,6 +35,9 @@ void test_scalar() {
   int a = 10;
   f(a);
   
+  struct { int bitfield : 3; } s = { 3 };
+  f(s.bitfield)
+  
   f(10);
 }