Support overloading of the subscript operator[], including support for

built-in operator candidates. Test overloading of '&' and ','.

In C++, a comma expression is an lvalue if its right-hand
subexpression is an lvalue. Update Expr::isLvalue accordingly.

llvm-svn: 59643

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index a179af8b145..061402076e5 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -412,6 +412,11 @@ Expr::isLvalueResult Expr::isLvalue(ASTContext &Ctx) const {
   case BinaryOperatorClass:
   case CompoundAssignOperatorClass: {
     const BinaryOperator *BinOp = cast<BinaryOperator>(this);
+
+    if (Ctx.getLangOptions().CPlusPlus && // C++ [expr.comma]p1
+        BinOp->getOpcode() == BinaryOperator::Comma)
+      return BinOp->getRHS()->isLvalue(Ctx);
+
     if (!BinOp->isAssignmentOp())
       return LV_InvalidExpression;