Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!mailrus!tut.cis.ohio-state.edu!lvc
From: lvc@tut.cis.ohio-state.edu (Lawrence V. Cipriani)
Newsgroups: comp.lang.c
Subject: Re: volatile
Message-ID: <9337@tut.cis.ohio-state.edu>
Date: 31 Mar 88 22:08:09 GMT
References: <12578@brl-adm.ARPA> <1988Mar25.172355.348@utzoo.uucp> <588@imagine.PAWL.RPI.EDU> <1988Mar29.004454.2867@utzoo.uucp> <134@wyse.wyse.com> <9176@tut.cis.ohio-state.edu> <18686@think.UUCP>
Organization: The Ohio State University Dept of CIS
Lines: 29

In article <18686@think.UUCP> barmar@fafnir.think.com.UUCP (Barry Margolin) writes:
>In article <9176@tut.cis.ohio-state.edu> lvc@tut.cis.ohio-state.edu (Lawrence V. Cipriani) writes:
>>	... my small example of using volatile ...
>>
>>If the volatile were dropped off, the compiler would be free to
>>optimize out the "impossible" code. ...

>	... Notes on use of static ...
>Barry Margolin

You are right.  Try this instead:

	volatile static customer_changeable_var = 0;

	main()
		...blah blah blah...

	if (customer_changeable_var != 0)
	{
		...code for optional feature...
	}

This would be in a compiled program a customer could edit with adb
or sdb.  If the compiler were free to optimize out the "impossible"
code this would no longer work.  Thanks for the note.

-- 
Larry Cipriani, AT&T Network Systems and Ohio State University
Domain: lvc@tut.cis.ohio-state.edu
Path: ...!cbosgd!osu-cis!tut.cis.ohio-state.edu!lvc (weird but right)