From 62aa19a5a529b972e6e0d92c57ff773daddd22a2 Mon Sep 17 00:00:00 2001
From: Valentin Clement <clementval@gmail.com>
Date: Tue, 24 Jan 2023 16:37:52 +0100
Subject: [PATCH] [flang] Keep a fir.box type when doing an array of derived
 type component

When referencing a single component from a polymorphic array in an expression,
the rebox operation should output a boxed array of that component type and
not a polymorphic boxed array as it was done.

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D142462
---
 flang/lib/Lower/ConvertExpr.cpp  |  2 +-
 flang/test/Lower/polymorphic.f90 | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/flang/lib/Lower/ConvertExpr.cpp b/flang/lib/Lower/ConvertExpr.cpp
index 6c49302..499d1dd 100644
--- a/flang/lib/Lower/ConvertExpr.cpp
+++ b/flang/lib/Lower/ConvertExpr.cpp
@@ -5580,7 +5580,7 @@ private:
       // value. The value of the box is forwarded in the continuation.
       mlir::Type reduceTy = reduceRank(arrTy, slice);
       mlir::Type boxTy = fir::BoxType::get(reduceTy);
-      if (memref.getType().isa<fir::ClassType>())
+      if (memref.getType().isa<fir::ClassType>() && !components.hasComponents())
         boxTy = fir::ClassType::get(reduceTy);
       if (components.substring) {
         // Adjust char length to substring size.
diff --git a/flang/test/Lower/polymorphic.f90 b/flang/test/Lower/polymorphic.f90
index fe6ae87..cded60f 100644
--- a/flang/test/Lower/polymorphic.f90
+++ b/flang/test/Lower/polymorphic.f90
@@ -839,6 +839,20 @@ module polymorphic_test
 ! CHECK: fir.store %[[EMBOX]] to %[[ALLOCA]] : !fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>>>
 ! CHECK: fir.call @_QMpolymorphic_testPpass_poly_pointer_optional(%[[ALLOCA]]) fastmath<contract> : (!fir.ref<!fir.class<!fir.ptr<!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>>>) -> ()
 
+  subroutine test_poly_array_component_output(p)
+    class(p1), pointer :: p(:)
+    print*, p(:)%a
+  end subroutine
+
+! CHECK-LABEL: func.func @_QMpolymorphic_testPtest_poly_array_component_output(
+! CHECK-SAME: %[[P]]: !fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>>>> {fir.bindc_name = "p"}) {
+! CHECK: %[[LOAD_P:.*]] = fir.load %[[P]] : !fir.ref<!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>>>>
+! CHECK: %[[FIELD_INDEX_A:.*]] = fir.field_index a, !fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>
+! CHECK: %[[SLICE:.*]] = fir.slice %{{.*}}#0, %{{.*}}, %{{.*}} path %[[FIELD_INDEX_A]] : (index, index, index, !fir.field) -> !fir.slice<1>
+! CHECK: %[[REBOX:.*]] = fir.rebox %[[LOAD_P]](%{{.*}}) [%[[SLICE]]] : (!fir.class<!fir.ptr<!fir.array<?x!fir.type<_QMpolymorphic_testTp1{a:i32,b:i32}>>>>, !fir.shift<1>, !fir.slice<1>) -> !fir.box<!fir.array<?xi32>>
+! CHECK: %[[BOX_NONE:.*]] = fir.convert %[[REBOX]] : (!fir.box<!fir.array<?xi32>>) -> !fir.box<none>
+! CHECK: %{{.*}} = fir.call @_FortranAioOutputDescriptor(%{{.*}}, %[[BOX_NONE]]) fastmath<contract> : (!fir.ref<i8>, !fir.box<none>) -> i1
+
 end module
 
 program test
-- 
2.7.4