[AST] Fixed extraneous warnings for binary conditional operator

Summary:
Binary conditional operator gave warnings where ternary operators
did not. They have been fixed to warn similarly to ternary operators.

Link: https://bugs.llvm.org/show_bug.cgi?id=42239

Reviewers: rsmith, aaron.ballman, nickdesaulniers

Reviewed By: rsmith, nickdesaulniers

Subscribers: srhines, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D63369

llvm-svn: 363857

1 files changed, 7 insertions, 6 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index f5714d93787..cc92689cb92 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -2453,12 +2453,13 @@ bool Expr::isUnusedResultAWarning(const Expr *&WarnE, SourceLocation &Loc,
     // If only one of the LHS or RHS is a warning, the operator might
     // be being used for control flow. Only warn if both the LHS and
     // RHS are warnings.
-    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
-    if (!Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx))
-      return false;
-    if (!Exp->getLHS())
-      return true;
-    return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
+    const auto *Exp = cast<ConditionalOperator>(this);
+    return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx) &&
+           Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
+  }
+  case BinaryConditionalOperatorClass: {
+    const auto *Exp = cast<BinaryConditionalOperator>(this);
+    return Exp->getFalseExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
   }
 
   case MemberExprClass: