volatile

[Lawrence V. Cipriani]

In article <18686 at think.UUCP> barmar at fafnir.think.com.UUCP (Barry Margolin) writes:
>In article <9176 at tut.cis.ohio-state.edu> lvc at 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 at tut.cis.ohio-state.edu
Path: ...!cbosgd!osu-cis!tut.cis.ohio-state.edu!lvc (weird but right)