Re: [Xen-devel] stdbool.h -nostdinc XSA-55 trouble

[Patrick Welche <prlw1@xxxxxxxxx>]

On Thu, Aug 08, 2013 at 04:23:57PM +0100, Ian Campbell wrote:
> On Thu, 2013-08-08 at 16:18 +0100, Patrick Welche wrote:
> > On Thu, Aug 08, 2013 at 02:11:16PM +0100, Jan Beulich wrote:
> > > >>> On 08.08.13 at 13:49, Patrick Welche <prlw1@xxxxxxxxx> wrote:
> > > > I hope that this is the right list for compilation issues.
> > > > 
> > > > When building libelf-tools.c with gcc 4.5.4 on NetBSD-current/amd64:
> > > > 
> > > > In file included from libelf-private.h:25:0,
> > > >                  from libelf-tools.c:19:
> > > >                  /usr/src/local/xen/xen/include/xen/libelf.h:32:21: 
> > > > fatal error: stdbool.h: 
> > > > No such file or directory
[...]
> > > No mystery, but also not immediately obvious: -iwithprefix adds
> > > the compiler's include directory to the end of the include search
> > > paths, thus allowing stdbool.h and stdarg.h to be found. For
> > > stdarg.h (which you ought to have the same problem with in
> > > libelf/) xen/stdarg.h already has special treatment for
> > > __OpenBSD__ and __NetBSD__ (i.e. avoiding similar problems
> > > for all the cases where xen/stdarg.h is used instead of plain
> > > stdarg.h).
> > > 
> > > Whether that's not the case on NetBSD, or whether that directory
> > > simply doesn't exist or is empty you'd need to find out on your
> > > installation.
> > 
> > So, in xen/arch/x86/Rules.mk, there is "-iwithprefix include",
> > which means add "include" to the end of the directory defined
> > by the "-iprefix DIR" option. I just looked on an ubuntu 10 box,
> > and gcc -v lists "--prefix=/usr" which seems to be used as the
> > default value of -iprefix. The gcc compiler on the NetBSD box
> > doesn't list --prefix as one of its configure options, so
> > I don't know what directory is used as the default prefix. ""?

After Ian's comment below - that bit of "--prefix=/usr" theory is
wrong as on the ubuntu box stdbool.h is indeed under /usr/lib/gcc...
and the default prefix is where gcc "staging files" are kept.

[...]
> > (/usr/include/stdbool.h is what we are aiming for.)
> 
> At least on Debian we are actually aiming
> for /usr/lib/gcc/x86_64-linux-gnu/X.Y/include/stdbool.h
> 
> I don't have /usr/include/stdbool.h. This makes sense since stdbool is,
> AIUI, a compiler provided interface, not a libc one.
> 
> Perhaps this is a difference between Linux and BSD?

So it seems. According to stdbool(3) on the NetBSD box

STANDARDS
     The <stdbool.h> header conforms to ISO/IEC 9899:1999 (``ISO C99'') and
     IEEE Std 1003.1-2001 (``POSIX.1'').

HISTORY
     The <stdbool.h> header was first introduced in NetBSD 1.6.

and ominously

     The ability to undefine and redefine the macros bool, true, and false is
     an obsolescent feature that may be withdrawn in a future version of a
     standard.

Does this have implications for the orginal XSA-55?

Cheers,

Patrick

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