[flang][hlfir] Fixed lowering for optional dummy.

We have to keep it as a box, since taking box_addr of the optional
box may be invalid.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D149505

1 files changed, 5 insertions, 0 deletions

diff --git a/flang/include/flang/Optimizer/Builder/HLFIRTools.h b/flang/include/flang/Optimizer/Builder/HLFIRTools.h
index 8f4eb713ae5d..5d64903eeb87 100644
--- a/flang/include/flang/Optimizer/Builder/HLFIRTools.h
+++ b/flang/include/flang/Optimizer/Builder/HLFIRTools.h
@@ -181,6 +181,11 @@ public:
     return base.getDefiningOp<fir::FortranVariableOpInterface>();
   }
 
+  bool isOptional() const {
+    auto varIface = getIfVariableInterface();
+    return varIface ? varIface.isOptional() : false;
+  }
+
   // Get the entity as an mlir SSA value containing all the shape, type
   // parameters and dynamic shape information.
   mlir::Value getBase() const { return *this; }