make the unused expression warning less noisy by not warning about comma exprs whose
LHS and RHS both have side effects.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@44486 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/AST/Expr.cpp b/AST/Expr.cpp
index 15fbb24..5871a5c 100644
--- a/AST/Expr.cpp
+++ b/AST/Expr.cpp
@@ -243,8 +243,15 @@
return UO->getSubExpr()->hasLocalSideEffect();
}
}
- case BinaryOperatorClass:
- return cast<BinaryOperator>(this)->isAssignmentOp();
+ case BinaryOperatorClass: {
+ const BinaryOperator *BinOp = cast<BinaryOperator>(this);
+ // Consider comma to have side effects if the LHS and RHS both do.
+ if (BinOp->getOpcode() == BinaryOperator::Comma)
+ return BinOp->getLHS()->hasLocalSideEffect() &&
+ BinOp->getRHS()->hasLocalSideEffect();
+
+ return BinOp->isAssignmentOp();
+ }
case CompoundAssignOperatorClass:
return true;