[Bug fortran/56816] ICE in delete_root

[mikael at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56816

--- Comment #7 from Mikael Morin <mikael at gcc dot gnu.org> 2013-04-03 
20:33:59 UTC ---
The following tentative patch uses the recent multiple change set facility.
It is not sufficient though. It triggers an assertion in
enforce_single_undo_checkpoint, called from gfc_commit_symbol which doesn't
support multiple change sets.

Index: match.c
===================================================================
--- match.c    (révision 196417)
+++ match.c    (copie de travail)
@@ -5365,6 +5365,7 @@ gfc_match_select_type (void)
   bool class_array;
   gfc_symbol *sym;
   gfc_namespace *parent_ns;
+  gfc_undo_change_set chg_syms;

   m = gfc_match_label ();
   if (m == MATCH_ERROR)
@@ -5375,6 +5376,7 @@ gfc_match_select_type (void)
     return m;

   gfc_current_ns = gfc_build_block_ns (gfc_current_ns);
+  gfc_new_undo_checkpoint (chg_syms);

   m = gfc_match (" %n => %e", name, &expr2);
   if (m == MATCH_YES)
@@ -5441,9 +5443,11 @@ gfc_match_select_type (void)

   select_type_push (expr1->symtree->n.sym);

+  gfc_drop_last_undo_checkpoint ();
   return MATCH_YES;

 cleanup:
+  gfc_restore_last_undo_checkpoint ();
   parent_ns = gfc_current_ns->parent;
   gfc_free_namespace (gfc_current_ns);
   gfc_current_ns = parent_ns;