Fix PR ada/63310

[Eric Botcazou]

This fixes the -fcompare-debug bootstrap failure reported by Jakub.

Tested on x86_64-suse-linux, applied on the mainline.


2015-06-29  Eric Botcazou  <ebotca...@adacore.com>

        PR ada/63310
        * gcc-interface/utils.c (gnat_write_global_declarations): Always
        build the dummy global variable if code was generated.

-- 
Eric Botcazou
Index: gcc-interface/utils.c
===================================================================
--- gcc-interface/utils.c	(revision 225111)
+++ gcc-interface/utils.c	(working copy)
@@ -5202,8 +5202,9 @@ gnat_write_global_declarations (void)
   tree iter;
 
   /* If we have declared types as used at the global level, insert them in
-     the global hash table.  We use a dummy variable for this purpose.  */
-  if (types_used_by_cur_var_decl && !types_used_by_cur_var_decl->is_empty ())
+     the global hash table.  We use a dummy variable for this purpose, but
+     we need to build it unconditionally to avoid -fcompare-debug issues.  */
+  if (first_global_object_name)
     {
       struct varpool_node *node;
       char *label;
@@ -5218,11 +5219,12 @@ gnat_write_global_declarations (void)
       node->definition = 1;
       node->force_output = 1;
 
-      while (!types_used_by_cur_var_decl->is_empty ())
-	{
-	  tree t = types_used_by_cur_var_decl->pop ();
-	  types_used_by_var_decl_insert (t, dummy_global);
-	}
+      if (types_used_by_cur_var_decl)
+	while (!types_used_by_cur_var_decl->is_empty ())
+	  {
+	    tree t = types_used_by_cur_var_decl->pop ();
+	    types_used_by_var_decl_insert (t, dummy_global);
+	  }
     }
 
   /* Output debug information for all global type declarations first.  This