[RFC] xnsprintf()

[Mark Kettenis <kettenis@gnu.org>]

The bootdisk of my workstation crashed, so I found myself replacing my
aging FreeBSD environment with a fresh OpenBSD snapshot.  The OpenBSD
toolchain complains about using dangerous functions like snprintf:

   libgdb.a(remote.o)(.text+0xb3b): In function `set_thread':
   ../../src/gdb/remote.c:1066: warning: sprintf() is often misused,
   please use snprintf()

Of course it is right, so I've started converting sprintf() into
snprintf().  While doing so, I find myself writing the following bit
of code over and over again:

   int size;
   size = snprintf (buf, sizeof buf, ...);
   gdb_assert (size < sizeof buf);

So right now I'm wondering whether we should have a function, say
xsnprintf(), that checks whether the string fits in the buffer, and
throws an internal-error if it doesn't.

Opinions?

Mark