Re: [PATCH] test-suite: new preprocessor test case

[Derek M Jones <derek@knosof.co.uk>]

Al,

> It doesn't.  6.10.3p11: "If there are sequences of preprocessing tokens
> within the list of arguments that would otherwise act as preprocessing
> directives, the behavior is undefined."
> 
> You are asking for identical nasal demons from two implementations, when
> it's not even promised that the same kind will fly on two invocations of
> the same implementation...

So what you are saying is that this is a bug in the header.
This is the approach I would favor.

> Seriously, this is undefined behaviour *and* it's extermely hard to come
> up with self-consistent semantics for it.  Standard doesn't even try and
> implementations are doing whatever's more convenient at the moment.  Try
> to think of it and you'll come up with really ugly corner cases very fast.

Unless gcc comes up with consistent behavior every time I would not
expect this usage to hang around very long in the header.

> What we probably ought to do is a warning when such stuff happens.

You mean a more easy to understand message.

-- 
Derek M. Jones                         tel: +44 (0) 1252 520 667
Knowledge Software Ltd                 mailto:derek@knosof.co.uk
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