Remove cleanups from execute_gdb_command

This replaces a cleanup in execute_gdb_command with an instance of
std::string.

Testing showed that this originally missed a cleanup that was returned
by prevent_dont_repeat.  This version of the patch changes
prevent_dont_repeat to return a scoped_restore rather than a cleanup.

2017-01-10  Tom Tromey  <tom@tromey.com>

	* top.c (prevent_dont_repeat): Change return type.
	* python/python.c (execute_gdb_command): Use std::string.
	Update.
	* guile/guile.c (gdbscm_execute_gdb_command): Update.
	* command.h (prevent_dont_repeat): Change return type.
	* breakpoint.c (bpstat_do_actions_1): Update.

gdb/ChangeLog

@@ -1,3 +1,12 @@
+2017-01-10  Tom Tromey  <tom@tromey.com>
+
+	* top.c (prevent_dont_repeat): Change return type.
+	* python/python.c (execute_gdb_command): Use std::string.
+	Update.
+	* guile/guile.c (gdbscm_execute_gdb_command): Update.
+	* command.h (prevent_dont_repeat): Change return type.
+	* breakpoint.c (bpstat_do_actions_1): Update.
+
 2017-01-10  Tom Tromey  <tom@tromey.com>
 
 	* value.h (scoped_value_mark::~scoped_value_mark): Call

gdb/breakpoint.c

@@ -4685,7 +4685,7 @@ bpstat_do_actions_1 (bpstat *bsp)
   executing_breakpoint_commands = 1;
   old_chain = make_cleanup (cleanup_executing_breakpoints, 0);
 
-  prevent_dont_repeat ();
+  scoped_restore preventer = prevent_dont_repeat ();
 
   /* This pointer will iterate over the list of bpstat's.  */
   bs = *bsp;

gdb/command.h

@@ -408,7 +408,7 @@ extern void error_no_arg (const char *) ATTRIBUTE_NORETURN;
 
 extern void dont_repeat (void);
 
-extern struct cleanup *prevent_dont_repeat (void);
+extern scoped_restore_tmpl<int> prevent_dont_repeat (void);
 
 /* Used to mark commands that don't do anything.  If we just leave the
    function field NULL, the command is interpreted as a help topic, or

gdb/guile/guile.c

@@ -332,7 +332,7 @@ gdbscm_execute_gdb_command (SCM command_scm, SCM rest)
       inner_cleanups = make_cleanup_restore_integer (&current_ui->async);
       current_ui->async = 0;
 
-      prevent_dont_repeat ();
+      scoped_restore preventer = prevent_dont_repeat ();
       if (to_string)
 	to_string_res = execute_command_to_string (command, from_tty);
       else

gdb/python/python.c

@@ -601,8 +601,7 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
   TRY
     {
       /* Copy the argument text in case the command modifies it.  */
-      char *copy = xstrdup (arg);
-      struct cleanup *cleanup = make_cleanup (xfree, copy);
+      std::string copy (arg);
       struct interp *interp;
 
       scoped_restore save_async = make_scoped_restore (&current_ui->async, 0);
@@ -614,12 +613,11 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
       interp = interp_lookup (current_ui, "console");
       current_uiout = interp_ui_out (interp);
 
-      prevent_dont_repeat ();
+      scoped_restore preventer = prevent_dont_repeat ();
       if (to_string)
-	to_string_res = execute_command_to_string (copy, from_tty);
+	to_string_res = execute_command_to_string (&copy[0], from_tty);
       else
-	execute_command (copy, from_tty);
-      do_cleanups (cleanup);
+	execute_command (&copy[0], from_tty);
     }
   CATCH (except, RETURN_MASK_ALL)
     {

gdb/top.c

@@ -755,13 +755,10 @@ dont_repeat (void)
 /* Prevent dont_repeat from working, and return a cleanup that
    restores the previous state.  */
 
-struct cleanup *
+scoped_restore_tmpl<int>
 prevent_dont_repeat (void)
 {
-  struct cleanup *result = make_cleanup_restore_integer (&suppress_dont_repeat);
-
-  suppress_dont_repeat = 1;
-  return result;
+  return make_scoped_restore (&suppress_dont_repeat, 1);
 }