If your system uses the SVr4 ABI (designed by Motorola), you will only
be able to compile my library files lib/format.c and lib/getargs.c if your
C-compiler supports the macro va_copy() or __va_copy() from stdarg.h.

Mach/Next STep/Apple Rhapsody on ppc use a 'void *' for the type va_list
so you don't need to make changes on these systems.

Solaris/ppc (made in 1992) is the first UNIX implementation for the PPC.
It includes the va_copy() macro that allows you to assign a C object of the
type va_list in a system independent way.

Linux/ppc uses exactly the same construct as Solaris for the type va_list.
You will only be able to compile lib/format.c and lib/getargs.c if your 
C-compiler includes the macro va_copy() or __va_copy(). If this is not the
case, you will need to upgrade your C-compiler first. GCC 2.8.0 and later
includes this macro.

Here is what Solaris /usr/include/sys/varargs.h looks like:

/*
 * va_copy is a Solaris extension to provide a portable way to perform
 * a variable argument list ``bookmarking'' function.
 */
#if defined(__ppc)
#defineva_copy(to, from)((to)[0] = (from)[0])
#else
#defineva_copy(to, from)((to) = (from))
#endif

To be able to compile my lib/format.c and lib/getargs.c on a OS
implementation that uses an array for va_list, you will need
this va_copy() enhancement too.

The files mentioned above already compile on a PPC Apple Rhapsody system.
But as mentioned before, Rhapsody uses a void * for va_list (maybe because
Apple includes badly designed international printf code from BSD 4.4
that requires va_list to be void * to work).

Notice:lib/format.c allows a %r format that needs additional features
in stdarg.h. You need to know whether va_list is an array.
I hope that GCC will include some definitions in future versions
that allow to propagate va_list type objects from var args
in function calls.

GCC
===

If you are not using GCC 2.8.0, you can add the following definition 
to va-ppc.h :

/usr/lib/gcc-lib/*-linux-gnulibc1/2.*/include/va-ppc.h

#defineva_copy(to, from)((to)[0] = (from)[0])

and to all other va-*.h files:

#defineva_copy(to, from)((to) = (from))

Important: Check before if you don't have a GCC that is already patched.

Joerg