1 files changed, 4 insertions, 0 deletions
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 3c8cbb56a0..68bce4b6f6 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -2026,6 +2026,10 @@ bool Expr::isUnusedResultAWarning(const Expr *&WarnE, SourceLocation &Loc,
   }
   case CXXFunctionalCastExprClass:
   case CStyleCastExprClass: {
+    // Ignore casts within macro expansions.
+    if (getExprLoc().isMacroID())
+      return false;
+
     // Ignore an explicit cast to void unless the operand is a non-trivial
     // volatile lvalue.
     const CastExpr *CE = cast<CastExpr>(this);