Using more than one 'yacc' in a sing - (nf)

[johnl at haddock.UUCP]

#R:sri-arpa:-1629500:haddock:16700009:000:1361
haddock!johnl    Feb  6 16:53:00 1984

I also had the same problem of using yacc in more than one place in a
program, but came up with a more overimplemented way of dealing with it.
I wrote a program called "entry" which you would call as:

 $ entry aoutfile name1 name2 ...

and it would fiddle bits in the aoutfile so that only the names you
specified (and any undefined externals) were global.  It basically
retroactively declared everything else in that object file to be
static.

The idea was that you compiled one yacc piece, linked it with a few
related modules, used "entry" on that so that only useful entries, not
including yy*, were global and linked that with other stuff.  You could
do this recursively depending on how much symbol hiding you want to do.
There were disadvantages, notably that the makefiles got ugly and the
debuggers got confused in the presence of many symbols with the same
name.

What you really want in such a case (and what I've never seen implemented
very well) is block structured link time symbol tables.  At compile time
if I have local variables named "i" in several routines, or even in
several blocks in the same routine, it doesn't cause any trouble.  It
would be nice to have link time be as nice.  As it is now, link time
symbols are sort of like variables in early Fortran II programs -- either
they're in common or they aren't.

John Levine, ima!johnl