[flang-commits] [flang] [Flang] - Handle `BoxCharType` in `fir.box_offset` op (PR #141713)

[via flang-commits]

================
@@ -4484,15 +4484,26 @@ void fir::IfOp::resultToSourceOps(llvm::SmallVectorImpl<mlir::Value> &results,
 llvm::LogicalResult fir::BoxOffsetOp::verify() {
   auto boxType = mlir::dyn_cast_or_null<fir::BaseBoxType>(
       fir::dyn_cast_ptrEleTy(getBoxRef().getType()));
-  if (!boxType)
-    return emitOpError("box_ref operand must have !fir.ref<!fir.box<T>> type");
+  mlir::Type boxCharType;
+  bool isBoxChar = false;
+  if (!boxType) {
+    boxCharType = mlir::dyn_cast_or_null<fir::BoxCharType>(
+        fir::dyn_cast_ptrEleTy(getBoxRef().getType()));
+    if (!boxCharType)
+      return emitOpError("box_ref operand must have !fir.ref<!fir.box<T>> or "
+                         "!fir.ref<!fir.boxchar<k>> type");
+    isBoxChar = true;
+  }
   if (getField() != fir::BoxFieldAttr::base_addr &&
       getField() != fir::BoxFieldAttr::derived_type)
     return emitOpError("cannot address provided field");
-  if (getField() == fir::BoxFieldAttr::derived_type)
+  if (getField() == fir::BoxFieldAttr::derived_type) {
+    if (isBoxChar)
+      return emitOpError("cannot address derived_type field of a fir.boxchar");
----------------
jeanPerier wrote:

nit: moving this checks under the `if (!boxType) {` and removing the isBoxChar would simplify the reading for me.

https://github.com/llvm/llvm-project/pull/141713