"shift" command support to GRUB script.

* include/grub/script_sh.h (grub_script_shift): New prototype.
	* script/execute.c (grub_script_shift): New function.
	* script/main.c (grub_script_init): Register shift command.
	(grub_script_fini): Unregister shift command.
	* util/grub-script-check.c (grub_script_cmd_shift): New function.

	* tests/grub_script_shift.in: New testcase.
	* conf/tests.rmk: Rules for new testcase.

ChangeLog

@@ -1,3 +1,16 @@
+2010-08-12  BVK Chaitanya  <bvk.groups@gmail.com>
+
+	"shift" command support to GRUB script.
+
+	* include/grub/script_sh.h (grub_script_shift): New prototype.
+	* script/execute.c (grub_script_shift): New function.
+	* script/main.c (grub_script_init): Register shift command.
+	(grub_script_fini): Unregister shift command.
+	* util/grub-script-check.c (grub_script_cmd_shift): New function.
+
+	* tests/grub_script_shift.in: New testcase.
+	* conf/tests.rmk: Rules for new testcase.
+
 2010-08-12  BVK Chaitanya  <bvk.groups@gmail.com>
 
 	"continue" command support to GRUB script.

conf/tests.rmk

@@ -80,6 +80,9 @@ grub_script_break_SOURCES = tests/grub_script_break.in
 check_SCRIPTS += grub_script_continue
 grub_script_continue_SOURCES = tests/grub_script_continue.in
 
+check_SCRIPTS += grub_script_shift
+grub_script_shift_SOURCES = tests/grub_script_shift.in
+
 # List of tests to execute on "make check"
 # SCRIPTED_TESTS    = example_scripted_test
 # SCRIPTED_TESTS   += example_grub_script_test
@@ -99,6 +102,7 @@ SCRIPTED_TESTS += grub_script_comments
 SCRIPTED_TESTS += grub_script_functions
 SCRIPTED_TESTS += grub_script_break
 SCRIPTED_TESTS += grub_script_continue
+SCRIPTED_TESTS += grub_script_shift
 
 # dependencies between tests and testing-tools
 $(SCRIPTED_TESTS): grub-shell grub-shell-tester

include/grub/script_sh.h

@@ -318,6 +318,9 @@ grub_err_t grub_script_execute (struct grub_script *script);
 /* Break command for loops.  */
 grub_err_t grub_script_break (grub_command_t cmd, int argc, char *argv[]);
 
+/* SHIFT command for GRUB script.  */
+grub_err_t grub_script_shift (grub_command_t cmd, int argc, char *argv[]);
+
 /* This variable points to the parsed command.  This is used to
    communicate with the bison code.  */
 extern struct grub_script_cmd *grub_script_parsed;

script/execute.c

@@ -59,6 +59,37 @@ grub_script_break (grub_command_t cmd, int argc, char *argv[])
   return GRUB_ERR_NONE;
 }
 
+grub_err_t
+grub_script_shift (grub_command_t cmd __attribute__((unused)),
+		   int argc, char *argv[])
+{
+  char *p = 0;
+  unsigned long n = 0;
+
+  if (! scope)
+    return GRUB_ERR_NONE;
+
+  if (argc == 0)
+    n = 1;
+
+  else if (argc > 1)
+    return GRUB_ERR_BAD_ARGUMENT;
+
+  else
+    {
+      n = grub_strtoul (argv[0], &p, 10);
+      if (*p != '\0')
+	return GRUB_ERR_BAD_ARGUMENT;
+    }
+
+  if (n > scope->argv.argc)
+    return GRUB_ERR_BAD_ARGUMENT;
+
+  scope->argv.argc -= n;
+  scope->argv.args += n;
+  return GRUB_ERR_NONE;
+}
+
 static int
 grub_env_special (const char *name)
 {
@@ -327,7 +358,7 @@ grub_script_execute_cmdline (struct grub_script_cmd *cmd)
 	  grub_free (assign);
 
 	  grub_snprintf (errnobuf, sizeof (errnobuf), "%d", grub_errno);
-	  grub_env_set ("?", errnobuf);
+	  grub_script_env_set ("?", errnobuf);
 
 	  grub_script_argv_free (&argv);
 	  grub_print_error ();

script/main.c

@@ -43,6 +43,7 @@ grub_normal_parse_line (char *line, grub_reader_getline_t getline)
 
 static grub_command_t cmd_break;
 static grub_command_t cmd_continue;
+static grub_command_t cmd_shift;
 
 void
 grub_script_init (void)
@@ -50,7 +51,9 @@ grub_script_init (void)
   cmd_break = grub_register_command ("break", grub_script_break,
 				     N_("[n]"), N_("Exit from loops"));
   cmd_continue = grub_register_command ("continue", grub_script_break,
-					N_("[n]"), N_("Coninue loops"));
+					N_("[n]"), N_("Continue loops"));
+  cmd_shift = grub_register_command ("shift", grub_script_shift,
+				     N_("[n]"), N_("Shift positional parameters."));
 }
 
 void
@@ -64,4 +67,7 @@ grub_script_fini (void)
     grub_unregister_command (cmd_continue);
   cmd_continue = 0;
 
+  if (cmd_shift)
+    grub_unregister_command (cmd_shift);
+  cmd_shift = 0;
 }

tests/grub_script_shift.in

@@ -0,0 +1,85 @@
+#! @builddir@/grub-shell-tester
+
+# Run GRUB script in a Qemu instance
+# Copyright (C) 2010  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/>.
+
+function f1 {
+  echo f1 '$@' $@
+  echo f1 '$*' $*
+  echo f1 $# $1 $2 $3
+  shift
+  echo f1 '$@' $@
+  echo f1 '$*' $*
+  echo f1 $# $1 $2 $3
+}
+
+f1
+f1 a
+f1 a b
+f1 a b c
+f1 a b c d
+f1 a b c d e
+
+function f2 {
+  echo f1 '$@' $@
+  echo f1 '$*' $*
+  echo f2 $# $1 $2 $3
+  shift 1
+  echo f1 '$@' $@
+  echo f1 '$*' $*
+  echo f2 $# $1 $2 $3
+}
+
+f2
+f2 a
+f2 a b
+f2 a b c
+f2 a b c d
+f2 a b c d e
+
+function f3 {
+  echo f1 '$@' $@
+  echo f1 '$*' $*
+  echo f3 $# $1 $2 $3
+  shift 3
+  echo f1 '$@' $@
+  echo f1 '$*' $*
+  echo f3 $# $1 $2 $3
+}
+
+f3
+f3 a
+f3 a b
+f3 a b c
+f3 a b c d
+f3 a b c d e
+
+function f4 {
+  echo f1 '$@' $@
+  echo f1 '$*' $*
+  echo f4 $# $1 $2 $3
+  shift 100
+  echo f1 '$@' $@
+  echo f1 '$*' $*
+  echo f4 $# $1 $2 $3
+}
+
+f4
+f4 a
+f4 a b
+f4 a b c
+f4 a b c d
+f4 a b c d e

util/grub-script-check.c

@@ -65,6 +65,14 @@ grub_script_break (grub_command_t cmd __attribute__((unused)),
   return 0;
 }
 
+grub_err_t
+grub_script_shift (grub_command_t cmd __attribute__((unused)),
+		   int argc __attribute__((unused)),
+		   char *argv[] __attribute__((unused)))
+{
+  return 0;
+}
+
 char *
 grub_script_execute_argument_to_string (struct grub_script_arg *arg __attribute__ ((unused)))
 {