[Bug fortran/41936] Memory leakage with allocatables and user-defined operators

["mikael at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41936

Mikael Morin <mikael at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch
                 CC|                            |mikael at gcc dot gnu.org

--- Comment #2 from Mikael Morin <mikael at gcc dot gnu.org> 2011-02-28 21:22:39 UTC ---
Fixed if one adds the code below (copied from gfc_conv_array_parameter).
I'm afraid this could change a memory leak into a double free (see PR 40850).
Also, not quite right (even if the middle-end optimizers are likely to fix it)
because it adds cleanup code to both foo and bar.

diff --git a/trans-expr.c b/trans-expr.c
index d6c1f9f..3919870 100644
--- a/trans-expr.c
+++ b/trans-expr.c
@@ -4900,6 +4900,19 @@ gfc_conv_expr_reference (gfc_se * se, gfc_expr * expr)

   /* Take the address of that value.  */
   se->expr = gfc_build_addr_expr (NULL_TREE, var);
+  if ((expr->ts.type == BT_DERIVED || expr->ts.type == BT_CLASS)
+      && expr->ts.u.derived->attr.alloc_comp
+      && expr->expr_type != EXPR_VARIABLE)
+    {
+      tree tmp;
+
+      tmp = build_fold_indirect_ref_loc (input_location, se->expr);
+      tmp = gfc_deallocate_alloc_comp (expr->ts.u.derived, tmp, expr->rank);
+      
+      /* The components shall be deallocated before
+         their containing entity.  */
+      gfc_prepend_expr_to_block (&se->post, tmp);
+    }
 }