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

[Akim Demaille]

>>>>> "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.


>> Today, I am more and more convinced that what would be really clean
>> is simply a list of macros to be traced, and each time a macro is
>> defined, we look at this list.

Gary> Ugh.  That sounds like a lot of unnecessary duplication in the
Gary> internal data, not to metion moving back towards keeping
Gary> multiple structures in synch.

I was just throwing ideas :)  MY main point was that attaching the
trace bit to the names is not enough if when we undefine names, then
we forget that bit.

>> I.e., if I `m4 -t foo', then, what ever the number of define and
>> undefine of foo, all invocation of the macro should be traced.
>> 
>> Up to now, only the invocations before the first undefine are
>> traced.  This is really what I'm looking for, and it is also what I
>> consider as the sanest semantics for traces.

Gary> You are saying that you are looking for the behaviour in the
Gary> `I.e., if I...' paragraph, right?  

Correct, sorry for the confusing words.

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.


Gary, congratulations: CVS Autoconf is happy with CVS M4 again :)
And vice-versa!