Re: [RFA] deleting breakpoints inside of 'commands' (again)

[Fernando Nasser <fnasser at redhat dot com>]

Don Howard wrote:
> 
> This implementation makes a copy of commands list that contain 'delete'
> or 'clear' commands.  It also attempts to clean up when an error in
> encountered.  Comments?
> 

This is much nicer.  Thanks!

The cli part is approved.

Fernando

P.S.: An extra blank line slipped in at the end of your breakpoint.c
patch.



> 2001-10-31  Don Howard  <dhoward@redhat.com>
> 
>         * breakpoint.c (bpstat_do_actions): Avoid deleting a 'commands'
>         list while executing that list.  Thanks to Pierre Muller
>         <muller@ics.u-strasbg.fr> for suggesting this implementation.
>         (cleanup_dup_command_lines): New function.
>         * cli/cli-script.c (dup_command_lines): New function.
>         * defs.h: Added declaration of new function.
> 
> Index: breakpoint.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/breakpoint.c,v
> retrieving revision 1.55
> diff -p -u -w -r1.55 breakpoint.c
> --- breakpoint.c        2001/10/20 23:54:29     1.55
> +++ breakpoint.c        2001/10/31 21:48:28
> @@ -1790,6 +1790,12 @@ cleanup_executing_breakpoints (PTR ignor
>    executing_breakpoint_commands = 0;
>  }
> 
> +static void
> +cleanup_dup_command_lines (PTR cmds)
> +{
> +  free_command_lines (cmds);
> +}
> +
>  /* Execute all the commands associated with all the breakpoints at this
>     location.  Any of these commands could cause the process to proceed
>     beyond this point, etc.  We look out for such changes by checking
> @@ -1800,7 +1806,6 @@ bpstat_do_actions (bpstat *bsp)
>  {
>    bpstat bs;
>    struct cleanup *old_chain;
> -  struct command_line *cmd;
> 
>    /* Avoid endless recursion if a `source' command is contained
>       in bs->commands.  */
> @@ -1824,17 +1829,40 @@ top:
> 
>    breakpoint_proceeded = 0;
>    for (; bs != NULL; bs = bs->next)
> +    {
> +      struct command_line *cmd;
> +      struct cleanup *new_old_chain;
> +
> +      cmd = 0;
> +      new_old_chain = 0;
> +
> +      /* If the command list for this breakpoint includes a statement
> +        that deletes breakpoints, we assume that the target may be
> +        this breakpoint, so we make a copy of the command list to
> +        avoid walking a list that has been deleted. */
> +
> +      for (cmd = bs->commands; cmd; cmd = cmd->next)
>      {
> -      cmd = bs->commands;
> -      while (cmd != NULL)
> +         if (!new_old_chain &&
> +             (strncmp (cmd->line, "dele", 4) == 0 ||
> +              strncmp (cmd->line, "clea", 4) == 0))
>         {
> +             cmd = dup_command_lines (cmd);
> +             new_old_chain = make_cleanup (cleanup_dup_command_lines, cmd);
> +           }
> +
>           execute_control_command (cmd);
> 
>           if (breakpoint_proceeded)
>             break;
> -         else
> -           cmd = cmd->next;
>         }
> +
> +      if (new_old_chain)
> +       {
> +         free_command_lines (&cmd);
> +         discard_cleanups (new_old_chain);
> +       }
> +
>        if (breakpoint_proceeded)
>         /* The inferior is proceeded by the command; bomb out now.
>            The bpstat chain has been blown away by wait_for_inferior.
> @@ -1844,6 +1872,7 @@ top:
>        else
>         bs->commands = NULL;
>      }
> +
> 
>    executing_breakpoint_commands = 0;
>    discard_cleanups (old_chain);
> Index: defs.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/defs.h,v
> retrieving revision 1.64
> diff -p -u -w -r1.64 defs.h
> --- defs.h      2001/10/17 20:35:31     1.64
> +++ defs.h      2001/10/31 21:48:28
> @@ -843,6 +843,7 @@ struct command_line
>  extern struct command_line *read_command_lines (char *, int);
> 
>  extern void free_command_lines (struct command_line **);
> +extern struct command_line * dup_command_lines (struct command_line *);
> 
>  /* To continue the execution commands when running gdb asynchronously.
>     A continuation structure contains a pointer to a function to be called
> Index: cli/cli-script.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/cli/cli-script.c,v
> retrieving revision 1.7
> diff -p -u -w -r1.7 cli-script.c
> --- cli-script.c        2001/06/17 15:16:12     1.7
> +++ cli-script.c        2001/10/31 21:48:29
> @@ -1005,6 +1005,59 @@ read_command_lines (char *prompt_arg, in
>    return (head);
>  }
> 
> +/* Duplicate a chain of struct command_line's */
> +
> +struct command_line *
> +dup_command_lines (struct command_line *l)
> +{
> +  struct command_line *dup = NULL;
> +  register struct command_line *next = NULL;
> +
> +
> +  for (; l ; l = l->next)
> +    {
> +      if (next == NULL)
> +       {
> +         dup = next = (struct command_line *)
> +           xmalloc (sizeof (struct command_line));
> +       }
> +      else
> +       {
> +         next->next = (struct command_line *)
> +           xmalloc (sizeof (struct command_line));
> +
> +         next = next->next;
> +       }
> +
> +
> +      if (next == NULL)
> +       return NULL;
> +
> +
> +      next->next = NULL;
> +      next->line = xstrdup (l->line);
> +      next->control_type = l->control_type;
> +      next->body_count = l->body_count;
> +
> +
> +      if (l->body_count > 0)
> +       {
> +         int i;
> +         struct command_line **blist = l->body_list;
> +
> +         next->body_list =
> +           (struct command_line **) xmalloc (sizeof (struct command_line *)
> +                                             * l->body_count);
> +
> +         for (i = 0; i < l->body_count; i++, blist++)
> +           next->body_list[i] = dup_command_lines (*blist);
> +       }
> +    }
> +
> +  return dup;
> +}
> +
> +
>  /* Free a chain of struct command_line's.  */
> 
>  void
> 
> --
> -Don
> dhoward@redhat.com
> gdb engineering

-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9