[Bug fortran/49954] ICE assigning concat expression to an array deferred-length string (realloc on assignment)

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49954

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-08-03 09:26:09 UTC ---
I thought about something like:

--- a/gcc/fortran/trans-array.c
+++ b/gcc/fortran/trans-array.c
@@ -7322,8 +7322,8 @@ gfc_alloc_allocatable_for_assignment (gfc_loopinfo *loop,
   /* Get the new lhs size in bytes.  */
   if (expr1->ts.type == BT_CHARACTER && expr1->ts.deferred)
     {
-      tmp = expr2->ts.u.cl->backend_decl;
-      gcc_assert (expr1->ts.u.cl->backend_decl);
+      tmp = rss->string_length;
+      gcc_assert (expr1->ts.u.cl->backend_decl && tmp);
       tmp = fold_convert (TREE_TYPE (expr1->ts.u.cl->backend_decl), tmp);
       gfc_add_modify (&fblock, expr1->ts.u.cl->backend_decl, tmp);
     }

However, that yields ".array_length" (i.e. the LHS) even for
  array_string(:)(1:1)
which has the length 1. However, at a glance, gfc_conv_concat_op seems to
properly set "se->string_length = len". Maybe it is not properly called for
rse->string_length?