Serious error-causing change in new CPP's -traditional behavior

[Zack Weinberg]

On Thu, May 04, 2000 at 07:06:52PM -0700, Jason R Thorpe wrote:
> There is a change in new CPP's behavior when -traditional is used, which
> causes the NetBSD/i386 kernel build to fail.  Not only is the behavior
> different than the CPP in EGCS 1.1.2, but it appears to be inconsistent
> with itself .. i.e. similar input is apparently processed differently
> when it should not be.
> 
> The code that it actually chokes on is a large, complicated macro that
> generates interrupt stubs, but I have a simple test case that demonstrates
> the problem.

...
> GNU CPP version 2.96 20000504 (experimental) (cpplib)
>  (NetBSD/i386 ELF)
> 
>  .globl Xresume666; Xresume666: ; cli ;Xintr 666: ; pushl $0

> Now, note that 20000504's CPP correctly concatenated `Xresume666'.  Perhaps
> it has to do with the fact that comment characters are appearing within
> a macro argument, and thus take a different code path to comment elimination.

I agree this is a bug.  The macro expander is being overhauled right
now, and we don't test -traditional mode much.  Could you try to come
up with a test case in C, not assembly?  Then it can be put into the
test suite.

This should be fixed within the next couple of weeks.  I can't provide
an immediate patch, because the code is in flux.

zw