Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!nosc!ucsd!ucsdhub!hp-sdd!hplabs!hpda!hpcuhb!hpcllla!hpclisp!hpclscu!shankar
From: shankar@hpclscu.HP.COM (Shankar Unni)
Newsgroups: comp.lang.c
Subject: Re: lint on malloc calls
Message-ID: <660017@hpclscu.HP.COM>
Date: 9 Sep 88 17:33:26 GMT
References: <39617@linus.UUCP>
Organization: HP NSG/ISD California Language Lab
Lines: 34

>
>	nextentry = (entry *) malloc(sizeof(entry));
>
>Running lint -bach yields:
>
>	phone.c(61): warning: illegal pointer combination
>	phone.c(61): warning: possible pointer alignment problem

Well, one can sort of understand lint's point of view (assuming a low-IQ
lint):

   Malloc returns a "char *" (presumably that's how you declared it)
   a "char *" can *THEORETICALLY* point to the middle of a word
	(even though we know that malloc always returns appropriately
	 aligned pointers)
   
   ergo, casting it to a struct pointer could *THEORETICALLY* cause
   an alignment problem (if the struct has an alignment >= 1 word)

   (The illegal combination message is just plain dumb...)

A possible workaround to pacify your lint:

Declare malloc as

   double *malloc();

--
Shankar.

P.S. I don't know what this would do on machines in which char *'s and
double *'s have different representations and in which malloc actually
returns a char * aligned to a double boundary (believe me, I know such a
machine). But if your machine doesn't have a terminal case of pointer-
representation-itis, the above should work...