[Bug fortran/50408] [4.6/4.7 regression] ICE in transfer_expr

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50408

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-11-24 22:20:55 UTC ---
Patch for this issue - note that there are more places which have to be checked
and potentially fixed. The second part is just a performance/algorithmic
optimization, which occurs in real code.

--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -1671,6 +1671,9 @@ gfc_get_extern_function_decl (gfc_symbol * sym)
       if (s && s->backend_decl)
        {
          sym->backend_decl = s->backend_decl;
+         if ((sym->ts.type == BT_DERIVED || sym->ts.type == BT_CLASS)
+             && sym->ts.u.derived->backend_decl == NULL)
+           gfc_get_derived_type (sym->ts.u.derived);
          return sym->backend_decl;
        }
     }
--- a/gcc/fortran/trans-types.c
+++ b/gcc/fortran/trans-types.c
@@ -2188,6 +2188,9 @@ gfc_copy_dt_decls_ifequal (gfc_symbol *from, gfc_symbol
*to,
   gfc_component *to_cm;
   gfc_component *from_cm;

+  if (from == to)
+    return 1;
+
   if (from->backend_decl == NULL
        || !gfc_compare_derived_types (from, to))
     return 0;