Re: New command eval.

[Andrey Borzenkov <arvidjaar@gmail.com>]

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В Sat, 11 May 2013 19:02:58 +0200
Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com> пишет:

> On 11.05.2013 18:35, Andrey Borzenkov wrote:
> 
> > +  grub_size_t size = argc; /* +1 for final zero */
> > +  char *str, *p;
> > +  grub_err_t ret;
> > +
> > +  if (argc == 0)
> > +    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("missing arguments"));
> > +
> 
> eval with no arguments returns success in bash, to match this behaviour,
> it should be GRUB_ERR_NONE and no use of grub_error
> 
> > +  for (i = 0; i < argc; i++)
> > +    size += grub_strlen (argv[i]);
> > +
> > +  str = p = grub_malloc (size);
> > +  if (!str)
> > +    return grub_errno;
> > +
> > +  for (i = 0; i < argc; i++)
> > +    {
> > +      grub_strcpy (p, argv[i]);
> > +      p += grub_strlen (argv[i]);
> 
> These 2 operations should be condensed by using grub_stpcpy
> 
> > +      *p++ = ' ';
> 
> 
> >-  grub_script_execute_sourcecode (script, 0, dummy);
> >+  grub_script_execute_sourcecode (script);
> (in menu_entry.c) here you need a new scope for consistency.
> 

diff --git a/ChangeLog b/ChangeLog
index cd8213a..60c64ee 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2013-05-11  Andrey Borzenkov <arvidjaar@gmail.com>
+
+	* grub-core/script/execute.c (grub_script_execute_sourcecode): Split
+	off new function grub_script_execute_new_scope. Change callers to use
+	either of them as appropriate.
+	* grub-core/commands/eval.c: New command eval.
+	* docs/grub.texi (Commands): Document it.
+
 2013-05-11  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	* util/grub-install.in: Gettextize "Not found" message.
diff --git a/docs/grub.texi b/docs/grub.texi
index 75a5ea4..9dcfa2d 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -3435,6 +3435,7 @@ you forget a command, you can run the command @command{help}
 * date::                        Display or set current date and time
 * drivemap::                    Map a drive to another
 * echo::                        Display a line of text
+* eval::                        Evaluate agruments as GRUB commands
 * export::                      Export an environment variable
 * false::                       Do nothing, unsuccessfully
 * gettext::                     Translate a string
@@ -3812,6 +3813,15 @@ character will print that character.
 @end deffn
 
 
+@node eval
+@subsection eval
+
+@deffn Command eval string ...
+Concatenate arguments together using single space as separator and evaluate
+result as sequence of GRUB commands.
+@end deffn
+
+
 @node export
 @subsection export
 
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 602b497..0fcc4e7 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -699,6 +699,11 @@ module = {
 };
 
 module = {
+  name = eval;
+  common = commands/eval.c;
+};
+
+module = {
   name = extcmd;
   common = commands/extcmd.c;
   common = lib/arg.c;
diff --git a/grub-core/commands/eval.c b/grub-core/commands/eval.c
new file mode 100644
index 0000000..f826a4f
--- /dev/null
+++ b/grub-core/commands/eval.c
@@ -0,0 +1,71 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 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/dl.h>
+#include <grub/misc.h>
+#include <grub/script_sh.h>
+#include <grub/command.h>
+#include <grub/i18n.h>
+#include <grub/term.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static grub_err_t
+grub_cmd_eval (grub_command_t cmd __attribute__((__unused__)),
+	       int argc, char *argv[])
+{
+  int i;
+  grub_size_t size = argc; /* +1 for final zero */
+  char *str, *p;
+  grub_err_t ret;
+
+  if (argc == 0)
+    return GRUB_ERR_NONE;
+
+  for (i = 0; i < argc; i++)
+    size += grub_strlen (argv[i]);
+
+  str = p = grub_malloc (size);
+  if (!str)
+    return grub_errno;
+
+  for (i = 0; i < argc; i++)
+    {
+      p = grub_stpcpy (p, argv[i]);
+      *p++ = ' ';
+    }
+  *--p = '\0';
+
+  ret = grub_script_execute_sourcecode (str);
+  grub_free (str);
+  return ret;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(eval)
+{
+  cmd = grub_register_command ("eval", grub_cmd_eval, N_("STRING ..."),
+				N_("Evaluate arguments as GRUB commands"));
+}
+
+GRUB_MOD_FINI(eval)
+{
+  grub_unregister_command (cmd);
+}
+
diff --git a/grub-core/normal/menu.c b/grub-core/normal/menu.c
index fba19db..9b88290 100644
--- a/grub-core/normal/menu.c
+++ b/grub-core/normal/menu.c
@@ -245,7 +245,7 @@ grub_menu_execute_entry(grub_menu_entry_t entry, int auto_boot)
   else
     grub_env_unset ("default");
 
-  grub_script_execute_sourcecode (entry->sourcecode, entry->argc, entry->args);
+  grub_script_execute_new_scope (entry->sourcecode, entry->argc, entry->args);
 
   if (errs_before != grub_err_printed_errors)
     grub_wait_after_message ();
diff --git a/grub-core/normal/menu_entry.c b/grub-core/normal/menu_entry.c
index fae258a..506715c 100644
--- a/grub-core/normal/menu_entry.c
+++ b/grub-core/normal/menu_entry.c
@@ -1160,7 +1160,7 @@ run (struct screen *screen)
       }
     script[size] = '\0';
   }
-  grub_script_execute_sourcecode (script, 0, dummy);
+  grub_script_execute_new_scope (script, 0, dummy);
   grub_free (script);
 
   if (errs_before != grub_err_printed_errors)
diff --git a/grub-core/script/execute.c b/grub-core/script/execute.c
index 9babbee..afd5513 100644
--- a/grub-core/script/execute.c
+++ b/grub-core/script/execute.c
@@ -856,19 +856,10 @@ grub_script_execute_sourcecode_getline (char **line,
 
 /* Execute a source script.  */
 grub_err_t
-grub_script_execute_sourcecode (const char *source, int argc, char **args)
+grub_script_execute_sourcecode (const char *source)
 {
   grub_err_t ret = 0;
   struct grub_script *parsed_script;
-  struct grub_script_scope new_scope;
-  struct grub_script_scope *old_scope;
-
-  new_scope.argv.argc = argc;
-  new_scope.argv.args = args;
-  new_scope.flags = 0;
-
-  old_scope = scope;
-  scope = &new_scope;
 
   while (source)
     {
@@ -880,13 +871,35 @@ grub_script_execute_sourcecode (const char *source, int argc, char **args)
       if (! parsed_script)
 	{
 	  ret = grub_errno;
+	  grub_free (line);
 	  break;
 	}
 
       ret = grub_script_execute (parsed_script);
+      grub_script_free (parsed_script);
       grub_free (line);
     }
 
+  return ret;
+}
+
+/* Execute a source script in new scope.  */
+grub_err_t
+grub_script_execute_new_scope (const char *source, int argc, char **args)
+{
+  grub_err_t ret = 0;
+  struct grub_script_scope new_scope;
+  struct grub_script_scope *old_scope;
+
+  new_scope.argv.argc = argc;
+  new_scope.argv.args = args;
+  new_scope.flags = 0;
+
+  old_scope = scope;
+  scope = &new_scope;
+
+  ret = grub_script_execute_sourcecode (source);
+
   scope = old_scope;
   return ret;
 }
diff --git a/include/grub/script_sh.h b/include/grub/script_sh.h
index 78602e4..57bdd4d 100644
--- a/include/grub/script_sh.h
+++ b/include/grub/script_sh.h
@@ -329,7 +329,8 @@ grub_err_t grub_script_execute_cmdwhile (struct grub_script_cmd *cmd);
 
 /* Execute any GRUB pre-parsed command or script.  */
 grub_err_t grub_script_execute (struct grub_script *script);
-grub_err_t grub_script_execute_sourcecode (const char *source, int argc, char **args);
+grub_err_t grub_script_execute_sourcecode (const char *source);
+grub_err_t grub_script_execute_new_scope (const char *source, int argc, char **args);
 
 /* Break command for loops.  */
 grub_err_t grub_script_break (grub_command_t cmd, int argc, char *argv[]);

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