Question

I know destructor shouldn’t not throw exception.

http://www.parashift.com/c++-faq-lite/dtors.html#faq-11.13

I have the following code :

~a()
{
    cleanup();
}

// I do not expect exception being thrown in this function.
// If exception really happen, I know that it is something not recoverable.
void a::cleaup()
{
    delete p;
}

In my static source code analysis, it complains that I shall call the cleanup function in this way :

~a()
{
    try {
        cleanup();
    }
    catch(...) {
        // What to do? Print out some logging message?
    }
}

// I do not expect exception being thrown in this function.
// If exception really happen, I know that it is something not recoverable.
void a::cleaup()
{
    delete p;
}

I am not sure whether this is a good practice, to place try…catch block in destructor, whenever it calls functions. As :

(1) If cleanup function able to throw exception, I know something bad had happened. I prefer it to be fail-fast. That is, just let the whole system crash, and let the programmer debugs it.

(2) Overhead occur while entering and exiting try…catch block.

(3) The code look cumbersome, with a lot of try…catch block around classes’ destructor.

I may miss out some other points, why try…catch block should be in place.

Thanks.

Answer 1

Since delete won’t throw, neither will cleanup and as such there is no need to put the call in try-catch.

Since your static analysis tool is probably having a hard time figuring that out, perhaps you could help it out (it’s only a guess though) by declaring cleanup as no-throw.

void cleanup() throw();