Article View: comp.arch
Article #12916Re: Aliasing, etc. in C
From: Chris Torek
Date: Wed, 28 Jan 1987 15:15
Date: Wed, 28 Jan 1987 15:15
29 lines
1594 bytes
1594 bytes
Guy hardly needs defending, but it may sound better coming from two people: /* this code is not portable */ int a,b, *ptr; ptr = &a; ptr++; /* ptr now points to b */ >[ From sun!gorodish!guy ] >>No program that relies on that is correct C, so no compiler is >>obliged to make them work. In article <7803@decwrl.DEC.COM> brandenberg@star.dec.com (bleakness...desolation...plastic forks...) writes: >Oh? If this is aberrant coding, you might want to look at your >varargs.h file whose operation relies on these assumptions; and this is >in the ANSI proposal. Wrong. *Varargs* is in the ANSI proposal. Neither the *Vax* *implementation* nor the *Sun* *implementation* (each of which works by peeking at stack addresses) is the ANSI proposal. Nor is Pyramid's implementation, which is considerably more complex and does *not* rely upon `ptr = &a; ptr++;' pointing to `b' (which is only sometimes the case). -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690) UUCP: seismo!mimsy!chris ARPA/CSNet: chris@mimsy.umd.edu
Technical Details
Message-ID:
<5230@mimsy.UUCP>Path:
arc1-ca.pugleaf.net!utzoo!mnetor!seismo!mimsy!chrisReferences:
<7803@decwrl.DEC.COM>Show Full Headers
Complete Article Headers
Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!seismo!mimsy!chris From: chris@mimsy.UUCP (Chris Torek) Newsgroups: comp.arch Subject: Re: Aliasing, etc. in C Message-ID: <5230@mimsy.UUCP> Date: Wed, 28-Jan-87 10:15:41 EST Article-I.D.: mimsy.5230 Posted: Wed Jan 28 10:15:41 1987 Date-Received: Sun, 1-Feb-87 02:49:41 EST References: <7803@decwrl.DEC.COM> Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742 Lines: 29 Summary: Guy is right (as usual)