Re: [Quantlib-dev] potentially uninitialized local variables in Analytic GJR-GARCH(1, 1) Engine

[Luigi B. <lui...@gm...>]

On Fri, 2009-11-27 at 12:15 +0100, Ferdinando Ametrano wrote:
> warning C4701: potentially uninitialized local variable 'ex'
> used	c:\projects\quantlib\trunk\quantlib\ql\pricingengines\vanilla\analyticgjrgarchengine.cpp	268
> warning C4701: potentially uninitialized local variable 'k3'
> used	c:\projects\quantlib\trunk\quantlib\ql\pricingengines\vanilla\analyticgjrgarchengine.cpp	279
> warning C4701: potentially uninitialized local variable 'k4'
> used	c:\projects\quantlib\trunk\quantlib\ql\pricingengines\vanilla\analyticgjrgarchengine.cpp	279
> warning C4701: potentially uninitialized local variable 'sigma'
> used	c:\projects\quantlib\trunk\quantlib\ql\pricingengines\vanilla\analyticgjrgarchengine.cpp	267
> 
> using potentially uninitialized local variables smells like a genuine bug to me

Yes--in your compiler's branch detection algorithm :)

The variables above are all initialized one way or the other in a
section of code that reads:

if (init_ != true || constants_match != true || ...) {
    ... the variables are initialized to some values ...
}
else if (init_ == true && constants_match == true) {
    ... the variables are initialized to some other values ...
}

My guess is that since a final "else" is missing, the compiler doesn't
realize that between them the two conditions cover all possible cases.

Of course the if could be rewritten so that the warning disappears,
though---the "else if" could just be an "else" (and of course, the
"init_ != true" and "init_ == true" should be just "!init_" and
"init_"...)

Luigi


-- 

Though this be madness, yet there is method in't. 
-- Hamlet, Act II, scene II