break command support

script/execute.c

@@ -30,8 +30,29 @@
    is sizeof (int) * 3, and one extra for a possible -ve sign.  */
 #define ERRNO_DIGITS_MAX  (sizeof (int) * 3 + 1)
 
+static unsigned long active_loops;
+static unsigned long active_breaks;
 static struct grub_script_scope *scope = 0;
 
+grub_err_t
+grub_script_break (grub_command_t cmd __attribute__((unused)),
+		   int argc, char *argv[])
+{
+  char *p = 0;
+  unsigned long count;
+
+  if (argc == 0)
+    count = 1;
+
+  else if ((argc > 1) ||
+	   (count = grub_strtoul (argv[0], &p, 10)) > active_loops ||
+	   (*p != '\0'))
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, "bad break");
+
+  active_breaks = count;
+  return GRUB_ERR_NONE;
+}
+
 static char *
 grub_script_env_get (const char *name)
 {
@@ -242,8 +263,10 @@ grub_err_t
 grub_script_function_call (grub_script_function_t func, int argc, char **args)
 {
   grub_err_t ret = 0;
+  unsigned long loops = active_loops;
   struct grub_script_scope new_scope;
 
+  active_loops = 0;
   new_scope.argc = argc;
   new_scope.args = args;
   grub_list_push (GRUB_AS_LIST_P (&scope), GRUB_AS_LIST (&new_scope));
@@ -251,6 +274,7 @@ grub_script_function_call (grub_script_function_t func, int argc, char **args)
   ret = grub_script_execute (func->func);
 
   grub_list_pop (GRUB_AS_LIST_P (&scope));
+  active_loops = loops;
   return ret;
 }
 
@@ -338,7 +362,7 @@ grub_script_execute_cmdlist (struct grub_script_cmd *list)
   struct grub_script_cmd *cmd;
 
   /* Loop over every command and execute it.  */
-  for (cmd = list->next; cmd; cmd = cmd->next)
+  for (cmd = list->next; cmd && ! active_breaks; cmd = cmd->next)
     ret = grub_script_execute_cmd (cmd);
 
   return ret;
@@ -380,14 +404,22 @@ grub_script_execute_cmdfor (struct grub_script_cmd *cmd)
   if (!args)
     return grub_errno;
 
+  active_loops++;
   result = 0;
   for (i = 0; i < argcount; i++)
     {
-      grub_script_env_set (cmdfor->name->str, args[i]);
-      result = grub_script_execute_cmd (cmdfor->list);
+      if (! active_breaks)
+	{
+	  grub_script_env_set (cmdfor->name->str, args[i]);
+	  result = grub_script_execute_cmd (cmdfor->list);
+	}
       grub_free (args[i]);
     }
 
+  if (active_breaks)
+    active_breaks--;
+
+  active_loops--;
   grub_free (args);
   return result;
 }
@@ -400,6 +432,7 @@ grub_script_execute_cmdwhile (struct grub_script_cmd *cmd)
   int result;
   struct grub_script_cmdwhile *cmdwhile = (struct grub_script_cmdwhile *) cmd;
 
+  active_loops++;
   result = 0;
   do {
     cond = grub_script_execute_cmd (cmdwhile->cond);
@@ -407,8 +440,16 @@ grub_script_execute_cmdwhile (struct grub_script_cmd *cmd)
       break;
 
     result = grub_script_execute_cmd (cmdwhile->list);
+
+    if (active_breaks)
+      {
+	active_breaks--;
+	break;
+      }
+
   } while (1); /* XXX Put a check for ^C here */
 
+  active_loops--;
   return result;
 }
 

script/main.c

@@ -17,6 +17,7 @@
  */
 
 #include <grub/dl.h>
+#include <grub/i18n.h>
 #include <grub/parser.h>
 #include <grub/script_sh.h>
 
@@ -49,6 +50,8 @@ static struct grub_parser grub_sh_parser =
 GRUB_MOD_INIT(sh)
 {
   grub_parser_register ("grub", &grub_sh_parser);
+  grub_register_command ("break", grub_script_break,
+			 N_("[n]"), N_("Exit from loops"));
 }
 
 GRUB_MOD_FINI(sh)