Handle volatile box types

Author: ashermancinelli

flang/include/flang/Optimizer/Dialect/FIRTypes.td

@@ -90,7 +90,7 @@ def fir_BoxType : FIR_Type<"Box", "box", [], "BaseBoxType"> {
 
   let extraClassDeclaration = [{
     mlir::Type getElementType() const { return getEleTy(); }
-    bool isVolatile() const { return (bool)getIsVolatile(); }
+    bool isVolatile() const { return getIsVolatile(); }
   }];
 
   let genVerifyDecl = 1;

flang/lib/Optimizer/Dialect/FIROps.cpp

@@ -1840,10 +1840,10 @@ llvm::LogicalResult fir::EmboxOp::verify() {
     return emitOpError("slice must not be provided for a scalar");
   if (getSourceBox() && !mlir::isa<fir::ClassType>(getResult().getType()))
     return emitOpError("source_box must be used with fir.class result type");
-  // if (fir::isa_volatile_type(getMemref().getType()) !=
-  //     fir::isa_volatile_type(getResult().getType()))
-  //   return emitOpError("input and output types must have the same
-  //   volatility");
+  if (fir::isa_volatile_type(getMemref().getType()) !=
+      fir::isa_volatile_type(getResult().getType()))
+    return emitOpError("cannot convert between volatile and non-volatile "
+                       "types, use fir.volatile_cast instead");
   return mlir::success();
 }
 

flang/lib/Optimizer/Dialect/FIRType.cpp

@@ -681,8 +681,9 @@ mlir::Type changeElementType(mlir::Type type, mlir::Type newElementType,
         mlir::Type newInnerType =
             changeElementType(t.getEleTy(), newElementType, false);
         if (turnBoxIntoClass)
-          return fir::ClassType::get(newInnerType);
-        return fir::BoxType::get(newInnerType);
+          return fir::ClassType::get(
+              newInnerType); // TODO: volatility on class types
+        return fir::BoxType::get(newInnerType, t.isVolatile());
       })
       .Default([&](mlir::Type t) -> mlir::Type {
         assert((fir::isa_trivial(t) || llvm::isa<fir::RecordType>(t) ||
@@ -1381,11 +1382,12 @@ changeTypeShape(mlir::Type type,
           return fir::SequenceType::get(*newShape, seqTy.getEleTy());
         return seqTy.getEleTy();
       })
-      .Case<fir::ReferenceType>([&](fir::ReferenceType rt) -> mlir::Type {
-        return fir::ReferenceType::get(changeTypeShape(rt.getEleTy(), newShape),
-                                       rt.isVolatile());
+      .Case<fir::ReferenceType, fir::BoxType>([&](auto t) -> mlir::Type {
+        using FIRT = decltype(t);
+        return FIRT::get(changeTypeShape(t.getEleTy(), newShape),
+                         t.isVolatile());
       })
-      .Case<fir::PointerType, fir::HeapType, fir::BoxType, fir::ClassType>(
+      .Case<fir::PointerType, fir::HeapType, fir::ClassType>(
           [&](auto t) -> mlir::Type {
             using FIRT = decltype(t);
             return FIRT::get(changeTypeShape(t.getEleTy(), newShape));