[flang] Component references are volatile if their parent is (#138339)

Component references inherit volatility from their base derived types.
Moved the base type volatility check before the box type is built, and
merge it (instead of overwrite it) with the volatility of the base type.

Author: ashermancinelli

flang/lib/Lower/ConvertExprToHLFIR.cpp

@@ -236,6 +236,12 @@ class HlfirDesignatorBuilder {
         isVolatile = true;
     }
 
+    // Check if the base type is volatile
+    if (partInfo.base.has_value()) {
+      mlir::Type baseType = partInfo.base.value().getType();
+      isVolatile = isVolatile || fir::isa_volatile_type(baseType);
+    }
+
     // Arrays with non default lower bounds or dynamic length or dynamic extent
     // need a fir.box to hold the dynamic or lower bound information.
     if (fir::hasDynamicSize(resultValueType) ||
@@ -249,12 +255,6 @@ class HlfirDesignatorBuilder {
             /*namedConstantSectionsAreAlwaysContiguous=*/false))
       return fir::BoxType::get(resultValueType, isVolatile);
 
-    // Check if the base type is volatile
-    if (partInfo.base.has_value()) {
-      mlir::Type baseType = partInfo.base.value().getType();
-      isVolatile = fir::isa_volatile_type(baseType);
-    }
-
     // Other designators can be handled as raw addresses.
     return fir::ReferenceType::get(resultValueType, isVolatile);
   }

flang/test/Lower/volatile-derived-type.f90

@@ -0,0 +1,48 @@
+! RUN: bbc --strict-fir-volatile-verifier %s -o - | FileCheck %s
+! Ensure member access of a volatile derived type is volatile.
+  type t
+    integer :: e(4)=2
+  end type t
+  type(t), volatile :: f
+  call test (f%e(::2))
+contains
+  subroutine test(v)
+    integer, asynchronous :: v(:)
+  end subroutine
+end
+! CHECK-LABEL:   func.func @_QQmain() {
+! CHECK:           %[[VAL_0:.*]] = arith.constant 4 : index
+! CHECK:           %[[VAL_1:.*]] = arith.constant 1 : index
+! CHECK:           %[[VAL_2:.*]] = arith.constant 2 : index
+! CHECK:           %[[VAL_3:.*]] = arith.constant 0 : index
+! CHECK:           %[[VAL_4:.*]] = fir.dummy_scope : !fir.dscope
+! CHECK:           %[[VAL_5:.*]] = fir.address_of(@_QFE.b.t.e) : !fir.ref<!fir.array<2x1x!fir.type<_QM__fortran_type_infoTvalue{genre:i8,__padding0:!fir.array<7xi8>,value:i64}>>>
+! CHECK:           %[[VAL_6:.*]] = fir.shape_shift %[[VAL_3]], %[[VAL_2]], %[[VAL_3]], %[[VAL_1]] : (index, index, index, index) -> !fir.shapeshift<2>
+! CHECK:           %[[VAL_7:.*]]:2 = hlfir.declare %[[VAL_5]](%[[VAL_6]]) {fortran_attrs = #fir.var_attrs<target>, uniq_name = "_QFE.b.t.e"} :
+! CHECK:           %[[VAL_8:.*]] = fir.address_of(@_QFE.n.e) : !fir.ref<!fir.char<1>>
+! CHECK:           %[[VAL_9:.*]]:2 = hlfir.declare %[[VAL_8]] typeparams %[[VAL_1]] {fortran_attrs = #fir.var_attrs<target>, uniq_name = "_QFE.n.e"} : (!fir.ref<!fir.char<1>>, index) -> (!fir.ref<!fir.char<1>>, !fir.ref<!fir.char<1>>)
+! CHECK:           %[[VAL_10:.*]] = fir.address_of(@_QFE.di.t.e) : !fir.ref<!fir.array<4xi32>>
+! CHECK:           %[[VAL_11:.*]] = fir.shape %[[VAL_0]] : (index) -> !fir.shape<1>
+! CHECK:           %[[VAL_12:.*]]:2 = hlfir.declare %[[VAL_10]](%[[VAL_11]]) {fortran_attrs = #fir.var_attrs<target>, uniq_name = "_QFE.di.t.e"} : (!fir.ref<!fir.array<4xi32>>, !fir.shape<1>) -> (!fir.ref<!fir.array<4xi32>>, !fir.ref<!fir.array<4xi32>>)
+! CHECK:           %[[VAL_13:.*]] = fir.address_of(@_QFE.n.t) : !fir.ref<!fir.char<1>>
+! CHECK:           %[[VAL_14:.*]]:2 = hlfir.declare %[[VAL_13]] typeparams %[[VAL_1]] {fortran_attrs = #fir.var_attrs<target>, uniq_name = "_QFE.n.t"} : (!fir.ref<!fir.char<1>>, index) -> (!fir.ref<!fir.char<1>>, !fir.ref<!fir.char<1>>)
+! CHECK:           %[[VAL_15:.*]] = fir.alloca !fir.type<_QFTt{e:!fir.array<4xi32>}> {bindc_name = "f", uniq_name = "_QFEf"}
+! CHECK:           %[[VAL_16:.*]] = fir.volatile_cast %[[VAL_15]] : (!fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>>) -> !fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>, volatile>
+! CHECK:           %[[VAL_17:.*]]:2 = hlfir.declare %[[VAL_16]] {fortran_attrs = #fir.var_attrs<volatile>, uniq_name = "_QFEf"} : (!fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>, volatile>) -> (!fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>, volatile>, !fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>, volatile>)
+! CHECK:           %[[VAL_18:.*]] = fir.address_of(@_QQ_QFTt.DerivedInit) : !fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>>
+! CHECK:           fir.copy %[[VAL_18]] to %[[VAL_17]]#0 no_overlap : !fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>>, !fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>, volatile>
+! CHECK:           %[[VAL_20:.*]] = fir.shape_shift %[[VAL_3]], %[[VAL_1]] : (index, index) -> !fir.shapeshift<1>
+! CHECK:           %[[VAL_21:.*]]:2 = hlfir.declare %{{.+}}(%[[VAL_20]]) {fortran_attrs = #fir.var_attrs<target>, uniq_name = "_QFE.c.t"} :
+! CHECK:           %[[VAL_24:.*]] = fir.shape %[[VAL_2]] : (index) -> !fir.shape<1>
+! CHECK:           %[[VAL_25:.*]] = hlfir.designate %[[VAL_17]]#0{"e"} <%[[VAL_11]]> (%[[VAL_1]]:%[[VAL_0]]:%[[VAL_2]])  shape %[[VAL_24]] : (!fir.ref<!fir.type<_QFTt{e:!fir.array<4xi32>}>, volatile>, !fir.shape<1>, index, index, index, !fir.shape<1>) -> !fir.box<!fir.array<2xi32>, volatile>
+! CHECK:           %[[VAL_26:.*]] = fir.volatile_cast %[[VAL_25]] : (!fir.box<!fir.array<2xi32>, volatile>) -> !fir.box<!fir.array<2xi32>>
+! CHECK:           %[[VAL_27:.*]] = fir.convert %[[VAL_26]] : (!fir.box<!fir.array<2xi32>>) -> !fir.box<!fir.array<?xi32>>
+! CHECK:           fir.call @_QFPtest(%[[VAL_27]]) fastmath<contract> : (!fir.box<!fir.array<?xi32>>) -> ()
+! CHECK:           return
+! CHECK:         }
+! CHECK-LABEL:   func.func private @_QFPtest(
+! CHECK-SAME:                                %[[VAL_0:[0-9]+|[a-zA-Z$._-][a-zA-Z0-9$._-]*]]: !fir.box<!fir.array<?xi32>> {fir.asynchronous, fir.bindc_name = "v"}) attributes {fir.host_symbol = @_QQmain, llvm.linkage = #llvm.linkage<internal>} {
+! CHECK:           %[[VAL_1:.*]] = fir.dummy_scope : !fir.dscope
+! CHECK:           %[[VAL_2:.*]]:2 = hlfir.declare %[[VAL_0]] dummy_scope %[[VAL_1]] {fortran_attrs = #fir.var_attrs<asynchronous>, uniq_name = "_QFFtestEv"} : (!fir.box<!fir.array<?xi32>>, !fir.dscope) -> (!fir.box<!fir.array<?xi32>>, !fir.box<!fir.array<?xi32>>)
+! CHECK:           return
+! CHECK:         }