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From: chris@MIMSY.UMD.EDU.UUCP
Newsgroups: mod.computers.pyramid
Subject: Re:  another c bug?
Message-ID: <8608012332.AA29573@mimsy.umd.edu>
Date: Fri, 1-Aug-86 19:32:01 EDT
Article-I.D.: mimsy.8608012332.AA29573
Posted: Fri Aug  1 19:32:01 1986
Date-Received: Sat, 2-Aug-86 03:57:17 EDT
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Approved: info-pyramid@mimsy.umd.edu

This is not a compiler bug.  It is not legal to take the address
of one argument and use that to compute the address of another
argument.  It works on all pure stack machines as long as you know
the direction of stack growth.  It does not work on mixed stack/register
machines like the Pyramid.

The proper thing to do in larn's case is to use varargs and vprintf.
I am not sure if vprintf is in the `ucb universe' C library, but


	vprintf(fmt, args)
		char *fmt;
		va_list args;
	{

		_doprnt(fmt, args, stdout);
	}

should work (since I know how Pyramid did their varargs).  Given
vprintf, change

	show_int_args (args)
	int args;
	{
	    int     *pargs;
	    int     i;
	
	    pargs = &args;
	    while (*pargs != 0)
	        printf ("%d : ", *pargs++);
	    printf ("%d\n", 0);
	}

to

	#include <varargs.h>

	show_int_args(va_alist)
		va_dcl
	{
		register int i;
		va_list p;

		va_start(p);
		for (;;) {
			i = va_arg(p, int);
			if (i == 0)
				break;
			printf("%d : ", i);
		}
		printf("0\n");	/* simplified */
		va_end(p);
	}

	/* emulate a standard printf() */
	xprintf(va_alist)
		va_dcl
	{
		char *fmt;
		va_list p;

		va_start(p);
		fmt = va_arg(p, char *);
		vprintf(fmt, p);
		va_end(p);
	}

Chris