weeding out c++ keywords from sys/sys
avg at icyb.net.ua
Sun Feb 15 10:53:41 PST 2009
on 15/02/2009 19:50 Marcel Moolenaar said the following:
> On Feb 15, 2009, at 7:33 AM, Christoph Mallon wrote:
>> More robust error handling and less tedious resouce management
>> directly come to mind:
>> Just look at normal C functions which allocate resources and have
>> multiple points which can fail. They are the usual mess of if()s, goto
>> error and lots of cleanup code. Further all this code looks pretty
>> much the same in several modules. In C++ you write the resource
>> handling code once (constructors/destructors) and then you cannot
>> forget to clean up, because thanks to scoping and defined life ranges
>> it happens automatically.
> While on the surface this looks better, under the hood
> it's just the same. Worse in most likelihood, because
> with C the programmer writes the logic that is known to
> be needed (assuming no bugs). With C++ it's the compiler
> that generates code that handles all possible scenarios,
> and goes beyond what is strictly needed -- as such the
> cost tends to be higher, even when there are no errors
> or exceptions.
Then maybe we should stick to assembly? Just thinking about how I have
two use two operators "/", "%" where I can do with only one x86 assembly
instruction makes me mad - not.
I.e. this is not to say that I am against assembly - there are many
places in our kernel that would be plain impossible to code with C.
And not to say that I am against C. This is only to say that there are
certain things that are much easier, and safer too, to code in C++ that
in C. And that might be in kernel too.
> I'm not saying this is a problem. All I'm saying is that
> you move responsibility from the programmer to the compiler
> and in general this comes at a (runtime_ cost. One we may
> very well accept, mind you...
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