It would probably be pretty easy for you as a human (and thus being much smarter than the h2ph script) to clean up stdarg.ph to make it not emit any warnings. Avoiding new uses of h2ph and *.ph files would also be a good idea, BTW (though I'm not implying any judgement on what you are currently doing).

I've done a little more investigating and have found that the warning is being generated by my use of this line -
use Sys::Syslog qw(:DEFAULT setlogsock);

The relevant line in the stdarg.ph file is -
 undef(&__need___va_list) if defined(&__need___va_list);

And in /usr/lib/gcc-lib/i386-redhat-linux/egcs-2.91.66/include/stdarg.h there are the two lines that you suggested would be there.

a's post is interesting too, seeing as the eventual target platform for the program is Solaris... I'll get in touch with the client on Monday and find out if they get the same problem, or whether they've resolved it in the way you suggest (tidying up the stdarg.ph).

Thanks very much for the responses :0)

Pete