[Bug fortran/60255] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |janus at gcc dot gnu.org

--- Comment #2 from janus at gcc dot gnu.org ---
The error message comes from find_intrinsic_vtab, to which we'd have to pass a
locus in order to show a proper line number. Currently we use
gfc_current_locus, which is no good since the error happens during resolution.

Also I think the 'TODO' is not suitable here: It is meant for the developer and
not the user, and as such belongs in the source code and not into an error
message.

What does it actually take to make this feature work? Simply removing the error
and using internally charlen=0 to identify deferred length makes the test
module compile:


Index: class.c
===================================================================
--- class.c    (revision 207836)
+++ class.c    (working copy)
@@ -2404,18 +2404,9 @@ find_intrinsic_vtab (gfc_typespec *ts)
   gfc_symbol *copy = NULL, *src = NULL, *dst = NULL;
   int charlen = 0;

-  if (ts->type == BT_CHARACTER)
-    {
-      if (ts->deferred)
-    {
-      gfc_error ("TODO: Deferred character length variable at %C cannot "
-             "yet be associated with unlimited polymorphic entities");
-      return NULL;
-    }
-      else if (ts->u.cl && ts->u.cl->length
-           && ts->u.cl->length->expr_type == EXPR_CONSTANT)
-    charlen = mpz_get_si (ts->u.cl->length->value.integer);
-    }
+  if (ts->type == BT_CHARACTER && !ts->deferred && ts->u.cl &&
ts->u.cl->length
+      && ts->u.cl->length->expr_type == EXPR_CONSTANT)
+    charlen = mpz_get_si (ts->u.cl->length->value.integer);

   /* Find the top-level namespace.  */
   for (ns = gfc_current_ns; ns; ns = ns->parent)



Apparently we do not handle any non-constant string lengths currently. I guess
all of those should either be rejected (like deferred lengths) or we should
just make them work.