[flang] Use genExprBox for the rhs when calling PointerAssociate for unlimited polymorphic pointer

[clementval]

Summary

In D139019 the assumption was made that the rhs was also the MutableBox
but this is not a constraint. Use genExprBox instead. Also the allowed
conversion in D139019 was not correct. Remoed it since it is not needed anymore.

[clementval]

clang-format

[jeanPerier]

LGTM, thanks

flang/include/flang/Optimizer/Dialect/FIRType.h

 
 /// Return true iff `ty` is the type of an ALLOCATABLE entity or value.
 bool isAllocatableType(mlir::Type ty);
 
 /// Return true iff `ty` is the type of a boxed record type.
 /// e.g. !fir.box<!fir.type<derived>>
 bool isBoxedRecordType(mlir::Type ty);
 
-/// Return true iff `ty` is a !fir.ref<!fir.box<T>> type.
-bool isRefBoxType(mlir::Type ty);
-
-/// Return true iff `ty` is !fir.box<none> type.
-bool isOpaqueDescType(mlir::Type ty);
-
 /// Return true iff `ty` is the type of an polymorphic entity or
 /// value.
 bool isPolymorphicType(mlir::Type ty);
 
 /// Return true iff `ty` is the type of an unlimited polymorphic entity or
 /// value.
 bool isUnlimitedPolymorphicType(mlir::Type ty);
 

flang/lib/Lower/Bridge.cpp

std::visit(
 
               std::optional<Fortran::evaluate::DynamicType> lhsType =
                   assign.lhs.GetType();
               // Delegate pointer association to unlimited polymorphic pointer
               // to the runtime. element size, type code, attribute and of
               // course base_addr might need to be updated.
               if (lhsType && lhsType->IsUnlimitedPolymorphic()) {
                 mlir::Value lhs = genExprMutableBox(loc, assign.lhs).getAddr();
-                mlir::Value rhs = genExprMutableBox(loc, assign.rhs).getAddr();
+                mlir::Value rhs =
+                    fir::getBase(genExprBox(loc, assign.rhs, stmtCtx));
                 Fortran::lower::genPointerAssociate(*builder, loc, lhs, rhs);
                 return;
               }
 
               llvm::SmallVector<mlir::Value> lbounds;
               for (const Fortran::evaluate::ExtentExpr &lbExpr : lbExprs)
                 lbounds.push_back(
                     fir::getBase(genExprValue(toEvExpr(lbExpr), stmtCtx)));

flang/lib/Optimizer/Dialect/FIROps.cpp

if ((isPointerCompatible(inType) && isPointerCompatible(outType)) ||
       (isFloatCompatible(inType) && isIntegerCompatible(outType)) ||
       (isFloatCompatible(inType) && isFloatCompatible(outType)) ||
       (isIntegerCompatible(inType) && isPointerCompatible(outType)) ||
       (isPointerCompatible(inType) && isIntegerCompatible(outType)) ||
       (inType.isa<fir::BoxType>() && outType.isa<fir::BoxType>()) ||
       (inType.isa<fir::BoxProcType>() && outType.isa<fir::BoxProcType>()) ||
       (fir::isa_complex(inType) && fir::isa_complex(outType)) ||
       (fir::isBoxedRecordType(inType) && fir::isPolymorphicType(outType)) ||
-      (fir::isPolymorphicType(inType) && fir::isPolymorphicType(outType)) ||
-      (fir::isRefBoxType(inType) && fir::isOpaqueDescType(outType)))
+      (fir::isPolymorphicType(inType) && fir::isPolymorphicType(outType)))
     return mlir::success();
   llvm::errs() << inType << " / " << outType << "\n";
   return emitOpError("invalid type conversion");
 }
 
 //===----------------------------------------------------------------------===//
 // CoordinateOp
 //===----------------------------------------------------------------------===//

flang/lib/Optimizer/Dialect/FIRType.cpp

if (auto boxTy = ty.dyn_cast<fir::BoxType>()) {
     if (boxTy.getEleTy().isa<fir::RecordType>())
       return true;
     mlir::Type innerType = boxTy.unwrapInnerType();
     return innerType && innerType.isa<fir::RecordType>();
   }
   return false;
 }
 
-bool isRefBoxType(mlir::Type ty) {
-  if (auto refTy = ty.dyn_cast<fir::ReferenceType>())
-    return refTy.getEleTy().isa<fir::BaseBoxType>();
-  return false;
-}
-
-bool isOpaqueDescType(mlir::Type ty) {
-  if (auto boxTy = ty.dyn_cast<fir::BoxType>())
-    if (boxTy.getEleTy().isa<mlir::NoneType>())
-      return true;
-  return false;
-}
-
 static bool isAssumedType(mlir::Type ty) {
   if (auto boxTy = ty.dyn_cast<fir::BoxType>()) {
     if (boxTy.getEleTy().isa<mlir::NoneType>())
       return true;
     if (auto seqTy = boxTy.getEleTy().dyn_cast<fir::SequenceType>())
       return seqTy.getEleTy().isa<mlir::NoneType>();
   }
   return false;

flang/test/Lower/polymorphic.f90

subroutine associate_up_pointer(r)
     p => r%rp
   end subroutine
 
 ! CHECK-LABEL: func.func @_QMpolymorphic_testPassociate_up_pointer(
 ! CHECK-SAME: %[[ARG0:.*]]: !fir.class<!fir.type<_QMpolymorphic_testTr1{rp:!fir.box<!fir.ptr<!fir.array<?xf32>>>}>> {fir.bindc_name = "r"}) {
 ! CHECK: %[[P:.*]] = fir.alloca !fir.class<!fir.ptr<!fir.array<?xnone>>> {bindc_name = "p", uniq_name = "_QMpolymorphic_testFassociate_up_pointerEp"}
 ! CHECK: %[[FIELD_RP:.*]] = fir.field_index rp, !fir.type<_QMpolymorphic_testTr1{rp:!fir.box<!fir.ptr<!fir.array<?xf32>>>}>
 ! CHECK: %[[COORD_RP:.*]] = fir.coordinate_of %[[ARG0]], %[[FIELD_RP]] : (!fir.class<!fir.type<_QMpolymorphic_testTr1{rp:!fir.box<!fir.ptr<!fir.array<?xf32>>>}>>, !fir.field) -> !fir.ref<!fir.box<!fir.ptr<!fir.array<?xf32>>>>
+! CHECK: %[[LOAD_RP:.*]] = fir.load %[[COORD_RP]] : !fir.ref<!fir.box<!fir.ptr<!fir.array<?xf32>>>>
+! CHECK: %[[REBOX_RP:.*]] = fir.rebox %[[LOAD_RP]](%{{.*}}) : (!fir.box<!fir.ptr<!fir.array<?xf32>>>, !fir.shift<1>) -> !fir.box<!fir.array<?xf32>>
 ! CHECK: %[[CONV_P:.*]] = fir.convert %[[P]] : (!fir.ref<!fir.class<!fir.ptr<!fir.array<?xnone>>>>) -> !fir.ref<!fir.box<none>>
-! CHECK: %[[CONV_RP:.*]] = fir.convert %[[COORD_RP]] : (!fir.ref<!fir.box<!fir.ptr<!fir.array<?xf32>>>>) -> !fir.box<none>
-! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[CONV_P]], %[[CONV_RP]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none
+! CHECK: %[[RP_BOX_NONE:.*]] = fir.convert %[[REBOX_RP]] : (!fir.box<!fir.array<?xf32>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAPointerAssociate(%[[CONV_P]], %[[RP_BOX_NONE]]) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>) -> none
 ! CHECK: return
 
 ! Test that the fir.dispatch operation is created with the correct pass object
 ! and the pass_arg_pos attribute is incremented correctly when character
 ! function result is added as argument.
 
   function get_tmp(this)
     class(c1) :: this