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From: Terry Lambert <tlambert@primenet.com>
Message-Id: <199801201933.MAA27126@usr04.primenet.com>
Subject: Nasty GCC bug?
To: current@freebsd.org
Date: Tue, 20 Jan 1998 19:33:18 +0000 (GMT)
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I have discovered what I think is a nasty bug, having to do with
passing signed smaller-than-int values to varradic functions.

#include <stdio.h>

/*
 * demonstrate bug with signed smaller-than-int arguments to
 * varradic functions...
 */
main()
{
        short           ss = 0xebeb;
        unsigned short  us = 0xebeb;
        char            sc = 0xeb;
        unsigned char   uc = 0xeb;

        printf( "Expecting 0x%04x, but getting 0x%04x\n", us, ss);
        printf( "Expecting 0x%02x, but getting 0x%02x\n", uc, sc);
}


What is happening is that the value is being sign-extended to int
when it is pushed on the stack.

I don't know how you would make "%d" and "%x" work at the same time,
without a type descriptor on the stack before the argument.

Maybe there needs to be a character type specifier for "%x"?


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.