gcc -E -traditional broken

[Zack Weinberg]

On Mon, Dec 11, 2000 at 10:40:40PM +0000, Neil Booth wrote:
> Zack Weinberg wrote:-
> 
> > That might do it, but I was avoiding work last night and fixed it
> > another way.  See what you think of this.  (Please pick up the test
> > cases even if you don't want the patch.)
> 
> The NUL errors just happened to show up for defined (they've only been
> there for about 3 days); they occur throughout tradcpp.c so I'd rather
> keep my patch.  I got segfaults with __INCLUDE_LEVEL__ when I was
> trying to figure out what was causing it.

As long as you're sure that that's sufficient.  The code path I saw it
going through was like this:

	rescan sees 'defined'
	rescan calls macroexpand
	macroexpand calls special_symbol
	special_symbol advances past '[(] macroname [)]'
		and inserts " 0 " or " 1 " into the output
	macroexpand returns without stacking a new buffer
	rescan assumes that if macroexpand didn't stack a new buffer,
		it didn't move ibp either, so it need not recheck
		against limit
	rescan walks past the end of the buffer.

However, rescan is a steaming pile of spaghetti, and it may well be
that taking NUL out of its is_nvspace causes it to go a different
way.

> I'll do your testcases soon.

I just discovered that tradcpp silently ignores #error, which means
that tr-defined.c can give false passes.  On the #assert argument, it
probably makes sense to add #error to tradcpp; this should be
relatively easy.

zw