Re: FYI: 13-gary-remove-redundant-traced-field.patch

[Gary V. Vaughan]

On Tue, Sep 18, 2001 at 02:42:16PM +0200, Akim Demaille wrote:
> >>>>> "Gary" == Gary V Vaughan <address@hidden> writes:
> 
> >>  Well, I reversed the patch we are debating about, and nothing
> >> changes, it's coming from another one.
> 
> Gary> Indeed.  The oldest m4 I have to hand is m4-1.4o, which also has
> Gary> the bug you describe :-(
> 
> In fact something got worse recently, something that broke Autoconf.
> In between 1.4 and 1.4o, indeed, yet something had changed, but it was
> imperceptible to Autoconf.
>
> [[snip]]
>
> Gary, congratulations: CVS Autoconf is happy with CVS M4 again :)
> And vice-versa!

These two cancel out right?  So we are back to the status quo?

> Gary> This means that we store the flag against whichever
> Gary> m4_token_data is stored in the named symbol when traceon is
> Gary> invoked, and can be turned off by traceoff with the name of some
> Gary> symbol that currently holds that m4_token_data.  I think there
> Gary> is one small wrinkle in this approach, in that the command line
> Gary> trace parameters will need to be stored for application a the
> Gary> end of command line processing... 
> 
> Agreed.  That's the list I was referring too.  Maybe more is needed to
> make sure a trace bit is not forgotten even if the macro is undefined.

That won't happen now (see the tests I committed).  The only thing I
am not sure about semantically is what should happen here:

  $ m4 -m load -t builtin << EOF
  changequote([, ])dnl
  builtin([__unix__])dnl
  unload([gnu])dnl
  load([gnu])dnl
  builtin([__unix__])dnl
  EOF
  
??  My current feeling is that this purely pathological, and the
current behaviour of losing the trace bit when the builtin is unloaded
from memory doesn't matter.

Thoughts?

Cheers,
        Gary.
-- 
  ())_. Gary V. Vaughan     gary@(oranda.demon.co.uk|gnu.org)
  ( '/  Research Scientist  http://www.oranda.demon.co.uk       ,_())____
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