Fix sysdeps/unix/sysv/linux/arm/libc-do-syscall.S warning

[Joseph Myers]

On Sun, 1 Mar 2015, Mike Frysinger wrote:

> On 26 Nov 2014 15:14, Joseph Myers wrote:
> > This patch fixes a warning
> > 
> > ../include/features.h:328:4: warning: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp]
> > 
> > seen when building for ARM.  This warning comes from libc-do-syscall.S
> > being built for nscd: the nscd build uses _FORTIFY_SOURCE, while .S
> > files aren't built with -O, and the combination produces a warning.
> > As _FORTIFY_SOURCE doesn't do anything for .S files, undefining it in
> > libc-do-syscall.S seems the simplest solution.
> 
> should we update features.h to avoid that define when __ASSEMBLER__ is defined ?
> seems like this warning can impact external code too.

I don't know.  To what extent do we support users including glibc header 
files from assembler code?

-- 
Joseph S. Myers
joseph@codesourcery.com