[flang] Support polymorphic inputs for UNPACK intrinsic

[clementval]

Summary

Result must carry the polymorphic type information
from the vector.

[jeanPerier]

LGTM

flang/lib/Optimizer/Builder/IntrinsicCall.cpp

IntrinsicLibrary::genUnpack(mlir::Type resultType,
   mlir::Value mask = fir::getBase(maskBox);
   unsigned maskRank = maskBox.rank();
 
   // Handle required field argument
   mlir::Value field = builder.createBox(loc, args[2]);
 
   // Create mutable fir.box to be passed to the runtime for the result.
   mlir::Type resultArrayType = builder.getVarLenSeqTy(resultType, maskRank);
-  fir::MutableBoxValue resultMutableBox =
-      fir::factory::createTempMutableBox(builder, loc, resultArrayType);
+  fir::MutableBoxValue resultMutableBox = fir::factory::createTempMutableBox(
+      builder, loc, resultArrayType, {},
+      fir::isPolymorphicType(vector.getType()) ? vector : mlir::Value{});
   mlir::Value resultIrBox =
       fir::factory::getMutableIRBox(builder, loc, resultMutableBox);
 
   fir::runtime::genUnpack(builder, loc, resultIrBox, vector, mask, field);
 
   return readAndAddCleanUp(resultMutableBox, resultType, "UNPACK");
 }
 

flang/test/Lower/polymorphic-temp.f90

 ! CHECK: %[[ZERO:.*]] = fir.zero_bits !fir.heap<!fir.array<?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>
 ! CHECK: %[[EMBOX_RES:.*]] = fir.embox %[[ZERO]](%{{.*}}) source_box %[[I]] : (!fir.heap<!fir.array<?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>, !fir.shape<1>, !fir.class<!fir.array<20x20x!fir.type<_QMpoly_tmpTp1{a:i32}>>>) -> !fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>>
 ! CHECK: fir.store %[[EMBOX_RES]] to %[[TMP_RES]] : !fir.ref<!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>>>
 ! CHECK: %[[RES_BOX_NONE:.*]] = fir.convert %[[TMP_RES]] : (!fir.ref<!fir.class<!fir.heap<!fir.array<?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>>>) -> !fir.ref<!fir.box<none>>
 ! CHECK: %[[I_BOX_NONE:.*]] = fir.convert %[[I]] : (!fir.class<!fir.array<20x20x!fir.type<_QMpoly_tmpTp1{a:i32}>>>) -> !fir.box<none>
 ! CHECK: %[[MASK_BOX_NONE:.*]] = fir.convert %[[EMBOXED_MASK]] : (!fir.box<!fir.array<20x20x!fir.logical<4>>>) -> !fir.box<none>
 ! CHECK: %{{.*}} = fir.call @_FortranAPack(%[[RES_BOX_NONE]], %[[I_BOX_NONE]], %[[MASK_BOX_NONE]], %{{.*}}, %{{.*}}, %{{.*}}) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>, !fir.box<none>, !fir.box<none>, !fir.ref<i8>, i32) -> none
 
+  subroutine check_unpack(r)
+    class(p1), intent(in) :: r(:,:)
+  end subroutine
+
+  subroutine test_temp_from_unpack(v, m, f)
+    class(p1), intent(in) :: v(:), f(:,:)
+    logical, intent(in) :: m(:,:)
+    call check_unpack(unpack(v,m,f))
+  end subroutine
+
+! CHECK-LABEL: func.func @_QMpoly_tmpPtest_temp_from_unpack(
+! CHECK-SAME: %[[V:.*]]: !fir.class<!fir.array<?x!fir.type<_QMpoly_tmpTp1{a:i32}>>> {fir.bindc_name = "v"}, %[[M:.*]]: !fir.box<!fir.array<?x?x!fir.logical<4>>> {fir.bindc_name = "m"}, %[[F:.*]]: !fir.class<!fir.array<?x?x!fir.type<_QMpoly_tmpTp1{a:i32}>>> {fir.bindc_name = "f"}) {
+! CHECK: %[[TMP_RES:.*]] = fir.alloca !fir.class<!fir.heap<!fir.array<?x?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>>
+! CHECK: %[[TMP_BOX_NONE:.*]] = fir.convert %[[TMP_RES]] : (!fir.ref<!fir.class<!fir.heap<!fir.array<?x?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>>>) -> !fir.ref<!fir.box<none>>
+! CHECK: %[[V_BOX_NONE:.*]] = fir.convert %[[V]] : (!fir.class<!fir.array<?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>) -> !fir.box<none>
+! CHECK: %[[M_BOX_NONE:.*]] = fir.convert %[[M]] : (!fir.box<!fir.array<?x?x!fir.logical<4>>>) -> !fir.box<none>
+! CHECK: %[[F_BOX_NONE:.*]] = fir.convert %[[F]] : (!fir.class<!fir.array<?x?x!fir.type<_QMpoly_tmpTp1{a:i32}>>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAUnpack(%[[TMP_BOX_NONE]], %[[V_BOX_NONE]], %[[M_BOX_NONE]], %[[F_BOX_NONE]], %{{.*}}, %{{.*}}) {{.*}} : (!fir.ref<!fir.box<none>>, !fir.box<none>, !fir.box<none>, !fir.box<none>, !fir.ref<i8>, i32) -> none
+
 end module