Re: Lisp-friendly backtraces [was: Lispy backtraces]

[Stefan Monnier]

> +  if (!NILP (nskip))
> +    {
> +      CHECK_NUMBER(nskip);
                    ^^
Please put a space before every open paren.

> +      EMACS_INT to_skip = XINT(nskip);
> +      while (to_skip > 0 && backtrace_p (pdl)) {
> +        to_skip--;
> +        pdl = backtrace_next (pdl);
> +      }
> +    }

Why not use the same `base` arg as `backtrace-frame` instead of `nskip`?

> -  defsubr (&Sbacktrace);
> +  DEFSYM (QCdebug_on_exit, ":debug-on-exit");
> +  defsubr (&Smapbacktrace);

You remove the defsubr of Sbacktrace, but you don't remove the
corresponding DEFUN.

> (defun backtrace ()
>   "Print a trace of Lisp function calls currently active.
> Output stream used is value of `standard-output'."
>   (mapbacktrace #'~/backtrace-1 1))

Have you tried it both byte-compiled and interpreted?  Maybe this
function is just simple enough that the result is the same in both
cases, but in my experience, the stack is sufficiently different in the
two cases that a constant nskip doesn't cut it (hence the use of `base`
in backtrace-frame).


        Stefan