Path: utzoo!utgpu!attcan!uunet!seismo!esosun!ucsdhub!ucsd!net1!hutch
From: hutch@net1.ucsd.edu (Jim Hutchison)
Newsgroups: comp.unix.questions
Subject: Re: alloca problem?
Keywords: alloca stack 386 sysv
Message-ID: <1239@ucsd.EDU>
Date: 7 Nov 88 05:10:26 GMT
References: <17026@santra.UUCP>
Sender: nobody@ucsd.EDU
Reply-To: hutch@net1.UUCP (Jim Hutchison)
Organization: some
Lines: 41

If the code below would pass an ANSI-ized type checking, I can
see no problem.  On the other hand, it looks like a relatively
easy-to-make typing error (not typography, type).

Are integers different from pointers?  For instance, are integers
aligned?  Are pointers?  Are they the same size?  Do pointers require
extra processing due to some unusual characteristic in the
architecture?

If alloca() is not declared a (char *) in the code of the failing
example, it will/should generate a different bit of code to handle the
way its return value is placed on the stack.  Try adding an:
	extern char *alloca();

Hopefully this will make the difference you were wanting.

In article <17026@santra.UUCP> hsu@santra.UUCP (Heikki Suonsivu) writes:
>Why this fails,
>
>huu(name)
>	char *name;
>{
>	char *d;
>
>	d = strcpy(alloca(strlen(name) + 1), name);
>}
>
>but this works?
>
>huu(name)
>	char *name;
>{
>	char *d;
>
>	d = alloca(strlen(name) + 1);
>	strcpy(d, name);
>}

/*    Jim Hutchison   		UUCP:	{dcdwest,ucbvax}!cs!net1!hutch
		    		ARPA:	JHutchison@ucsd.edu
     These are my opinions, and now you have your perceptions of them. */