set prompt-escape-character

set prompt-escape-character

[Andrew Cagney]

More -Wformat-nonliteral suprizes.  In trying to understand the "top.c" 
warnings from:

      /* FIXME: how to protect GDB from crashing
         from bad user-supplied format string? */
      sprintf (outp, fmt[0] == 0 ? default_fmt : fmt,
               tmp);

I discovered a new feature:

(top-gdb) set prompt-escape-char 0x25
(top-gdb) set prompt PC=0x%0x%$pc
PC=0x1802f68

Perhaps it could be change do use the printf code vis:
	set prompt "0x%x ", $pc

Anyway, Michael, was there any doco on this?  I can't find anything.

Andrew

Re: set prompt-escape-character

[Michael Snyder]

Andrew Cagney wrote:

> More -Wformat-nonliteral suprizes.  In trying to understand the 
> "top.c" warnings from:
>
>      /* FIXME: how to protect GDB from crashing
>         from bad user-supplied format string? */
>      sprintf (outp, fmt[0] == 0 ? default_fmt : fmt,
>               tmp);
>
> I discovered a new feature:
>
> (top-gdb) set prompt-escape-char 0x25
> (top-gdb) set prompt PC=0x%0x%$pc
> PC=0x1802f68
>
> Perhaps it could be change do use the printf code vis:
>     set prompt "0x%x ", $pc
>
> Anyway, Michael, was there any doco on this?  I can't find anything. 


No, I think I was hoping no one would use it.   ;-)
This was something that a customer forced us to add, back in the
"bad old days" when there wasn't much review over gdb. 
I really really tried to talk them out of it, honest.

Here's the change log entry:
1999-06-14  Michael Snyder  <msnyder@cleaver.cygnus.com>

        Add parameters to the gdb prompt.
        * top.c (prompt): Rename to gdb_prompt_string for clarity.
        (command_line_input): rename "prrompt" to prompt_arg for clarity.
        (gdb_readline): rename "prrompt" to prompt_arg for clarity.
        (read_command_lines): rename "prompt" to prompt_arg for clarity.
        (stop_sig): call get_prompt instead of reading prompt string 
directly.
        (command_loop): ditto.
        (simplified_command_loop): ditto.
        (gdb_prompt_escape): New variable.  Esc char for prompt parameters.
        (get_prompt_1): New function, workhorse for get_prompt.
        (get_prompt): Completely rewrite.  Add functionality for a
        parameterized prompt, ie. the displayed prompt can change according
        to the value of one or more expressions given as parameters in the
        prompt string.
        (init_main): use renamed variable gdb_prompt_string.  Add new
        command "set prompt-escape-char" to set gdb_prompt_escape.

Re: set prompt-escape-character

[Andrew Cagney]

> Andrew Cagney wrote:
> 
> More -Wformat-nonliteral suprizes.  In trying to understand the "top.c" warnings from:
> 
>      /* FIXME: how to protect GDB from crashing
>         from bad user-supplied format string? */
>      sprintf (outp, fmt[0] == 0 ? default_fmt : fmt,
>               tmp);
> 
> I discovered a new feature:
> 
> (top-gdb) set prompt-escape-char 0x25
> (top-gdb) set prompt PC=0x%0x%$pc
> PC=0x1802f68
> 
> Perhaps it could be change do use the printf code vis:
>     set prompt "0x%x ", $pc
> 
> Anyway, Michael, was there any doco on this?  I can't find anything.
> 
> No, I think I was hoping no one would use it.   ;-)
> This was something that a customer forced us to add, back in the
> "bad old days" when there wasn't much review over gdb. I really really tried to talk them out of it, honest.

Stan Shebs was always threatening to delete the undocumented commands 
;-)  Perhaps this should be silently dropped.

Andrew