cpp bug

[Zack Weinberg]

On Fri, Apr 07, 2000 at 12:34:32PM -0600, Tom Tromey wrote:
> Today I noticed that the current cvs gcc won't build itself on my
> Linux box.  After some investigation I traced it down to a bug in the
> preprocessor.
> 
> Consider the appended files.
> Currently I get this:
> 
>     creche. gcc -c m.c
>     m.c: In function `main':
>     m.c:6: `x' undeclared (first use in this function)
>     m.c:6: (Each undeclared identifier is reported only once
>     m.c:6: for each function it appears in.)

Thanks for reporting this.  Richard Henderson saw the same thing but I
didn't have enough context to reproduce the bug.

This is caused by overly eager multiple-include optimization.  I
didn't see it because the timebits.h (now bits/time.h) with glibc 2.1
works differently.

I'm testing a patch right now - the gist of it is to add

  pfile->only_seen_white = 0;

at the beginning of skip_if_group.

zw