Save 314 bytes on not handling contexts in core

normal/context.c

@@ -0,0 +1,172 @@
+/* env.c - Environment variables */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2003,2005,2006,2007,2008,2009  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/env.h>
+#include <grub/env_private.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/command.h>
+
+struct menu_pointer
+{
+  grub_menu_t menu;
+  struct menu_pointer *prev;
+};
+
+struct menu_pointer initial_menu;
+struct menu_pointer *current_menu = &initial_menu;
+
+void
+grub_env_unset_menu (void)
+{
+  current_menu->menu = NULL;
+}
+
+grub_menu_t
+grub_env_get_menu (void)
+{
+  return current_menu->menu;
+}
+
+void
+grub_env_set_menu (grub_menu_t nmenu)
+{
+  current_menu->menu = nmenu;
+}
+
+grub_err_t
+grub_env_context_open (int export)
+{
+  struct grub_env_context *context;
+  int i;
+  struct menu_pointer *menu;
+
+  context = grub_zalloc (sizeof (*context));
+  if (! context)
+    return grub_errno;
+  menu = grub_zalloc (sizeof (*menu));
+  if (! menu)
+    return grub_errno;
+
+  context->prev = grub_current_context;
+  grub_current_context = context;
+
+  menu->prev = current_menu;
+  current_menu = menu;
+
+  /* Copy exported variables.  */
+  for (i = 0; i < HASHSZ; i++)
+    {
+      struct grub_env_var *var;
+
+      for (var = context->prev->vars[i]; var; var = var->next)
+	{
+	  if (export && var->global)
+	    {
+	      if (grub_env_set (var->name, var->value) != GRUB_ERR_NONE)
+		{
+		  grub_env_context_close ();
+		  return grub_errno;
+		}
+	      grub_register_variable_hook (var->name, var->read_hook, var->write_hook);
+	    }
+	}
+    }
+
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_env_context_close (void)
+{
+  struct grub_env_context *context;
+  int i;
+  struct menu_pointer *menu;
+
+  if (! grub_current_context->prev)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT,
+		       "cannot close the initial context");
+
+  /* Free the variables associated with this context.  */
+  for (i = 0; i < HASHSZ; i++)
+    {
+      struct grub_env_var *p, *q;
+
+      for (p = grub_current_context->vars[i]; p; p = q)
+	{
+	  q = p->next;
+          grub_free (p->name);
+	  grub_free (p->value);
+	  grub_free (p);
+	}
+    }
+
+  /* Restore the previous context.  */
+  context = grub_current_context->prev;
+  grub_free (grub_current_context);
+  grub_current_context = context;
+
+  menu = current_menu->prev;
+  grub_free (current_menu);
+  current_menu = menu;
+
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_env_export (const char *name)
+{
+  struct grub_env_var *var;
+
+  var = grub_env_find (name);
+  if (var)
+    var->global = 1;
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_command_t export_cmd;
+
+static grub_err_t
+grub_cmd_export (struct grub_command *cmd __attribute__ ((unused)),
+		 int argc, char **args)
+{
+  if (argc < 1)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT,
+		       "no environment variable specified");
+
+  grub_env_export (args[0]);
+  return 0;
+}
+
+void
+grub_context_init (void)
+{
+  grub_env_export ("root");
+  grub_env_export ("prefix");
+
+  export_cmd = grub_register_command ("export", grub_cmd_export,
+				      "export ENVVAR", "Export a variable.");
+}
+
+void
+grub_context_fini (void)
+{
+  grub_unregister_command (export_cmd);
+}

normal/main.c

@@ -133,7 +133,7 @@ free_menu (grub_menu_t menu)
     }
 
   grub_free (menu);
-  grub_env_unset_data_slot ("menu");
+  grub_env_unset_menu ();
 }
 
 static void
@@ -174,7 +174,7 @@ grub_normal_add_menu_entry (int argc, const char **args,
     return grub_errno;
   classes_tail = classes_head;
 
-  menu = grub_env_get_data_slot ("menu");
+  menu = grub_env_get_menu ();
   if (! menu)
     return grub_error (GRUB_ERR_MENU, "no menu context");
 
@@ -357,14 +357,14 @@ read_config_file (const char *config)
 
   grub_menu_t newmenu;
 
-  newmenu = grub_env_get_data_slot ("menu");
+  newmenu = grub_env_get_menu ();
   if (! newmenu)
     {
       newmenu = grub_zalloc (sizeof (*newmenu));
       if (! newmenu)
 	return 0;
 
-      grub_env_set_data_slot ("menu", newmenu);
+      grub_env_set_menu (newmenu);
     }
 
   /* Try to open the config file.  */
@@ -562,6 +562,8 @@ grub_env_write_pager (struct grub_env_var *var __attribute__ ((unused)),
 
 GRUB_MOD_INIT(normal)
 {
+  grub_context_init ();
+
   /* Normal mode shouldn't be unloaded.  */
   if (mod)
     grub_dl_ref (mod);
@@ -589,6 +591,8 @@ GRUB_MOD_INIT(normal)
 
 GRUB_MOD_FINI(normal)
 {
+  grub_context_fini ();
+
   grub_set_history (0);
   grub_reader_unregister (&grub_normal_reader);
   grub_register_variable_hook ("pager", 0, 0);