Re: [Patch] OpenMP/Fortran: Handle polymorphic scalars in data-sharing FIRSTPRIVATE (PR86470)

[Andre Vehreschild <vehre@gmx.de>]

Hi Tobias,

in (look for ^^^):

diff --git a/gcc/fortran/trans-openmp.c b/gcc/fortran/trans-openmp.c
index 063d4c145e2..705cdc7749f 100644
--- a/gcc/fortran/trans-openmp.c
+++ b/gcc/fortran/trans-openmp.c
@@ -355,6 +355,51 @@ gfc_has_alloc_comps (tree type, tree decl)
   return false;
 }

+/* Return true if TYPE is polymorphic but not with pointer attribute.  */
+
+static bool
+gfc_is_polymorphic_nonptr (tree type)
+{
+  if (POINTER_TYPE_P (type))
+    type = TREE_TYPE (type);
+  if (TREE_CODE (type) != RECORD_TYPE)
+    return false;
+
+  tree field = TYPE_FIELDS (type);
+  if (!field || 0 != strcmp ("_data", IDENTIFIER_POINTER (DECL_NAME (field))))

^^^ here you are comparing the field - name

+    return false;
+  field = DECL_CHAIN (field);
+  if (!field || 0 != strcmp ("_vptr", IDENTIFIER_POINTER (DECL_NAME (field))))
+    return false;
+
+  return true;
+}
+
+/* Return true if TYPE is unlimited polymorphic but not with pointer attribute;
+   unlimited means also intrinsic types are handled and _len is used.  */
+
+static bool
+gfc_is_unlimited_polymorphic_nonptr (tree type)
+{
+  if (POINTER_TYPE_P (type))
+    type = TREE_TYPE (type);
+  if (TREE_CODE (type) != RECORD_TYPE)
+    return false;
+
+  tree field = TYPE_FIELDS (type); /* _data */
+  if (!field)

^^^ here you don't . So theoretically this routine could match a type which
has a _len as its third field, but that is not a unlim-poly class. Maybe factor
out the test from the above routine and unify with this one to reuse the test
for a BT_CLASS?!

+    return false;
+  field = DECL_CHAIN (field); /* _vptr */
+  if (!field)
+    return false;
+  field = DECL_CHAIN (field);
+  if (!field || 0 != strcmp ("_len", IDENTIFIER_POINTER (DECL_NAME (field))))
+    return false;
+
+  return true;
+}
+
+

---------------------------------------------------------------------------------------------------------------

Btw, I believe the first routine can be better replaced by:

static bool
gfc_is_polymorphic_nonptr (tree type)
{
  if (POINTER_TYPE_P (type))
    type = TREE_TYPE (type);
  return GFC_CLASS_TYPE_P (type);
}

I have no better solution for learning whether a tree's type is unlimited poly
yet.


@@ -740,6 +785,87 @@ gfc_omp_clause_copy_ctor (tree clause, tree dest, tree src)
   gcc_assert (OMP_CLAUSE_CODE (clause) == OMP_CLAUSE_FIRSTPRIVATE
 	      || OMP_CLAUSE_CODE (clause) == OMP_CLAUSE_LINEAR);

+  /* TODO: implement support for polymorphic arrays; reject for now.  */
+  /* Void arrays appear as var.0 = var._data.data. A bit hackish to
+     distinguish from 'type(c_ptr) :: var(5)' by scanning for '.';
+     this assumes that ASM_FORMAT_PRIVATE_NAME uses a '.', which most
+     systems do. */
+  if (TREE_CODE (type) == ARRAY_TYPE
+      && TREE_TYPE (type) == pvoid_type_node
+      && TREE_CODE (dest) == MEM_REF
+      && strchr (IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (dest, 0))), '.'))
+    fatal_error (input_location,
+		 "Sorry, polymorphic arrays not yet supported for "
+		 "firstprivate");

I totally agree that this is hackish and I don't like for that. But I can't
come up with a better solution at the moment.

The remainder looks ok to me.

Regards,
	Andre
--
Andre Vehreschild * Email: vehre ad gmx dot de