Check whether the operand to a noexcept expression is valid or not. Fixes PR15842.

llvm-svn: 235931

1 files changed, 10 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index b050c933044..bb67939ad89 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -5791,6 +5791,16 @@ ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
 
 ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
                                       SourceLocation RParen) {
+  // If the operand is an unresolved lookup expression, the expression is ill-
+  // formed per [over.over]p1, because overloaded function names cannot be used
+  // without arguments except in explicit contexts.
+  ExprResult R = CheckPlaceholderExpr(Operand);
+  if (R.isInvalid())
+    return R;
+
+  // The operand may have been modified when checking the placeholder type.
+  Operand = R.get();
+
   if (ActiveTemplateInstantiations.empty() &&
       Operand->HasSideEffects(Context, false)) {
     // The expression operand for noexcept is in an unevaluated expression