Re: [PATCH] unnamed union structure members are dangerous to expose in public headers

[Samuel Thibault <samuel.thibault@eu.citrix.com>]

Keir Fraser, le Tue 25 Mar 2008 17:33:53 +0000, a écrit :
> On 25/3/08 17:25, "Samuel Thibault" <samuel.thibault@eu.citrix.com> wrote:
> 
> > will return 0x13e0 when compiled without gcc -std=c99, while the
> > expected value is 0x1430, resulting to seg faults and all kinds of
> > tricks.  Compiling with
> > 
> > #include "/usr/include/xen/foreign/x86_64.h"
> > 
> > shows why:
> > 
> > /usr/include/xen/foreign/x86_64.h:88: warning: declaration does not
> > declare anything
> 
> This raises two obvious questions:
>  1. Why building with -std=c99?

Because in the wild public world, people may want to.

>  2. Why building without -Werror?

That wouldn't produce an error: the warning only appears when including
with "" instead of <>, so that gcc spits warnings of the header itself.

Samuel