cygwin-devel vs libbsd-devel: arc4random_stir() macro in stdlib.h breaks bsd/stdlib.h

[Corinna Vinschen]

On Mar 14 13:48, Christian Franke via Cygwin wrote:
> Corinna Vinschen via Cygwin wrote:
> > On Mar 13 08:59, Christian Franke via Cygwin wrote:
> > > Problem introduced in a8891c93:
> > > 
> > > $ cygcheck -f /usr/include/stdlib.h
> > > cygwin-devel-3.6.0-0.430.ga942476236b5
> > > 
> > > $ cygcheck -f /usr/include/bsd/stdlib.h
> > > libbsd-devel-0.12.2-2
> > > 
> > > $ gcc -c -xc - <<<'#include <bsd/stdlib.h>'
> > > In file included from <stdin>:1:
> > > /usr/include/bsd/stdlib.h:62:26: error: macro "arc4random_stir" passed 1
> > > arguments, but takes just 0
> > >     62 | void arc4random_stir(void);
> > >        |                          ^
> > > In file included from /usr/include/stdlib.h:26,
> > >                   from /usr/include/bsd/stdlib.h:32:
> > > /usr/include/cygwin/stdlib.h:26: note: macro "arc4random_stir" defined here
> > >     26 | #define arc4random_stir()
> > Should work again with cygwin-3.6.0-0.431.gad29c33229e5
> > 
> 
> This fixes the problem, thanks.
> 
> There are possibly still inconsistencies:
> 
> $ gcc -E -xc - <<<'#include <stdlib.h>' | grep arc4random_stir
> void arc4random_stir(void);
> 
> $ gcc -E -xc - <<<'#include <bsd/stdlib.h>' | grep arc4random_stir
> void arc4random_stir(void); // from cygwin/stdlib.h
> void arc4random_stir(void); // from bsd/stdlib.h

Yes, that's ok.  We could drop the declarations in bsd/stdlib.h,
but they are equivalent, so they don't hurt.

> $ gcc -E -xc - <<<'#include <stdlib.h>' | grep arc4random_addrandom
> 
> $ gcc -E -xc - <<<'#include <bsd/stdlib.h>' | grep arc4random_addrandom
> void arc4random_addrandom(unsigned char *dat, int datlen);

Yes, that's deliberate. arc4random_addrandom() shouldn't be used.
Well, arc4random_stir() shouldn't be used either, but there's the
autoconf problem with OpenSSH.

> $ gcc -E -xc - <<<'#include <bsd/stdlib.h>' | grep arc4random_buf
> void arc4random_buf (void *, size_t); // from stdlib.h
> void arc4random_buf(void *_buf, size_t n); // from bsd/stdlib.h

Equivalent, no worries.

> $ nm /usr/lib/libcygwin.a | grep ' arc4random'
> 0000000000000000 T arc4random
> 0000000000000000 T arc4random_addrandom
> 0000000000000000 T arc4random_buf
> 0000000000000000 T arc4random_stir
> 0000000000000000 T arc4random_uniform
> 
> $ nm /usr/lib/libbsd.dll.a | grep ' arc4random' || echo not found
> not found
> 
> I guess:
> - arc4random_addrandom() should be removed from libcygwin.a or added to
> cygwin/stdlib.h.

No, we can't do that (OpenSSH)

> - all arc4random*() should be hidden for __CYGWIN__ in bsd/stdlib.h.

This, we can do.  Let me check.


Corinna