[Bug fortran/56218] [OOP] Segfault with allocatable intent(out) derived type argument having allocatable component

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56218



--- Comment #2 from janus at gcc dot gnu.org 2013-02-06 10:08:59 UTC ---

Here is a draft patch, which seems to fix the test case:



Index: gcc/fortran/trans-decl.c

===================================================================

--- gcc/fortran/trans-decl.c    (revision 195644)

+++ gcc/fortran/trans-decl.c    (working copy)

@@ -3505,6 +3505,15 @@ init_intent_out_dt (gfc_symbol * proc_sym, gfc_wra

                   present, tmp,

                   build_empty_stmt (input_location));

       }

+    else if (CLASS_DATA (f->sym)->attr.allocatable)

+      {

+        present = gfc_class_data_get (f->sym->backend_decl);

+        present = fold_build2_loc (input_location, NE_EXPR,

+            boolean_type_node, present,

+            fold_convert (TREE_TYPE (present), null_pointer_node));

+        tmp = build3_loc (input_location, COND_EXPR, TREE_TYPE (tmp),

+                  present, tmp, build_empty_stmt (input_location));

+      }



     gfc_add_expr_to_block (&init, tmp);

       }







I think the same problem exists with TYPE(foo_t) instead of CLASS(foo_t), which

is not yet handled by the patch. However I do not get a valgrind failure for

the TYPE version for some reason.



In fact, I'm not sure if we correctly pass the argument to 'do_stuff' for the

TYPE version:



  struct foo_t * f;

      [...]

      f = 0B;

      do_stuff (&f);



If I'm not missing anything, I think we should pass 'f' directly instead of

'&f':



do_stuff (struct foo_t * & restrict f)

{

  if (f->a.data != 0B)

    {

      __builtin_free ((void *) f->a.data);

    }

  f->a.data = 0B;

}