Path: utzoo!attcan!uunet!husc6!ukma!rutgers!mit-eddie!uw-beaver!microsoft!tonyw
From: tonyw@microsoft.UUCP (Tony Williams)
Newsgroups: comp.lang.c
Subject: Re: lint warning messages with malloc()
Message-ID: <1169@microsoft.UUCP>
Date: 5 Nov 88 01:42:18 GMT
References: <142@cjsa.WA.COM> <355@marob.MASA.COM>
Reply-To: tonyw@microsoft.UUCP (Tony Williams)
Organization: Microsoft Corp., Redmond WA
Lines: 26

In article <355@marob.MASA.COM> daveh@marob.masa.com (Dave Hammond) writes:
|In article <142@cjsa.WA.COM> jeff@cjsa.WA.COM (Jeffery Small) writes:
|>When compiling a program on an AT&T 3B1 (running SystemV.2 +/-), I am
|>getting the following warning message from lint when I use malloc(3):
|>
|>	warning: possible pointer alignment problem
|>[...sample code deleted...]
|
|The program code is not at fault.  The problem is that lint does not
|know about malloc returning a suitably aligned pointer, therefore
|it complains.  You could do some fancy declaration footwork and declare
|
|X *malloc();

DO NOT DO THIS.  Since you are using lint, I assume you care somewhat
about portability :-).  There are machines out there for which
struct X * and char * have different representations.
On these machines, malloc will return the char* representation and you
must have the cast to convert it.

For the same reason, you must have a declaration
extern char* malloc();
in your programs, so that the compiler does not assume it is int.

I am afraid that we just have to live with some features of lint.
  Tony Williams