Re: [RFA 7/8] Use unique_xmalloc_ptr in execute_gdb_command

[Tom Tromey <tom@tromey.com>]

>>>>> "Tom" == Tom Tromey <tom@tromey.com> writes:

Tom> To my surprise, this patch is broken.
Tom> I must not have re-run the python tests locally after writing it :(

Tom> The problem is that prevent_dont_repeat returns a cleanup, which is then
Tom> left dangling after this patch.

Here's the updated patch.
I ran this one through the buildbot.

Tom

commit 1a638a680bae42954d4ebc896cb5828a9e27709b
Author: Tom Tromey <tom@tromey.com>
Date:   Mon Nov 28 21:11:53 2016 -0700

    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 be a class, avoiding a cleanup.
    
    2016-12-14  Tom Tromey  <tom@tromey.com>
    
    	* top.c (prevent_dont_repeat): Now a constructor.
    	* python/python.c (execute_gdb_command): Use std::string.
    	Update.
    	* guile/guile.c (gdbscm_execute_gdb_command): Update.
    	* command.h (prevent_dont_repeat): Now a class, not a function.
    	* breakpoint.c (bpstat_do_actions_1): Update.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 023c112..576270d 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2016-12-14  Tom Tromey  <tom@tromey.com>
+
+	* top.c (prevent_dont_repeat): Now a constructor.
+	* python/python.c (execute_gdb_command): Use std::string.
+	Update.
+	* guile/guile.c (gdbscm_execute_gdb_command): Update.
+	* command.h (prevent_dont_repeat): Now a class, not a function.
+	* breakpoint.c (bpstat_do_actions_1): Update.
+
 2016-12-13  Tom Tromey  <tom@tromey.com>
 
 	* value.h (value_freer::~value_freer): Call reset.
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 92aac3a..5af1dfa 100644
--- a/gdb/breakpoint.c
+++ b/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 ();
+  prevent_dont_repeat preventer ();
 
   /* This pointer will iterate over the list of bpstat's.  */
   bs = *bsp;
diff --git a/gdb/command.h b/gdb/command.h
index 965d91f..38ff38a 100644
--- a/gdb/command.h
+++ b/gdb/command.h
@@ -408,7 +408,17 @@ extern void error_no_arg (const char *) ATTRIBUTE_NORETURN;
 
 extern void dont_repeat (void);
 
-extern struct cleanup *prevent_dont_repeat (void);
+/* Prevent dont_repeat from doing anything.  */
+class prevent_dont_repeat
+{
+ public:
+
+  prevent_dont_repeat ();
+
+ private:
+
+  scoped_restore_tmpl<int> m_save_suppress;
+};
 
 /* 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
diff --git a/gdb/guile/guile.c b/gdb/guile/guile.c
index 9a126a1..599896b 100644
--- a/gdb/guile/guile.c
+++ b/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 ();
+      prevent_dont_repeat preventer ();
       if (to_string)
 	to_string_res = execute_command_to_string (command, from_tty);
       else
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 83b9805..cf9502d 100644
--- a/gdb/python/python.c
+++ b/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 ();
+      prevent_dont_repeat preventer ();
       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)
     {
diff --git a/gdb/top.c b/gdb/top.c
index 7d8b6e8..1aa926b 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -757,13 +757,9 @@ dont_repeat (void)
 /* Prevent dont_repeat from working, and return a cleanup that
    restores the previous state.  */
 
-struct cleanup *
-prevent_dont_repeat (void)
+prevent_dont_repeat::prevent_dont_repeat ()
+: m_save_suppress (&suppress_dont_repeat, 1)
 {
-  struct cleanup *result = make_cleanup_restore_integer (&suppress_dont_repeat);
-
-  suppress_dont_repeat = 1;
-  return result;
 }
 
 \f