[Development] Fornux C++ Superset

Eric Lemanisser eric.lemanissier at gmail.com
Wed Apr 25 14:17:42 CEST 2018

Le mer. 25 avr. 2018 à 14:03, Phil Bouchard <philippeb8 at gmail.com> a écrit :

> On 04/25/2018 04:46 AM, Edward Welbourne wrote:
> > Phil Bouchard (24 April 2018 19:05)
> >> I’m not sure if you read the link I posted about static analysis but a
> >> software bug can cause billion dollar projects like space shuttles to
> fail.
> >> Maybe MS Word was a bad example but they can be very costly.
> >
> > The Columbia crash wasn't a (computer) software issue.  One can think of
> > the organisational failure that lead to it as a (human) software issue,
> > but I don't think we have static analysis software for that.  The
> > closest you'll get is an ISO 9000 compliance auditor.
> >
> > The Ariane 5 crash was a software error, but it wasn't a memory abuse;
> > it was using an under-sized integer to hold a value that overflowed.
> > With luck, static analysis would find that, but it's a pointer abuse.
> >
> > The loss of the Mars Climate Orbiter involved a software bug, but it was
> > a wrong choice of units rather than a pointer abuse.  Mixing archaic
> > silly units with sensible SI ones has caused more grief for space
> > missions than pointer abuses.
> You need to see the big picture; memory leaks are the most difficult
> problems to solve. In the labs you stress-test your software for a few
> days but in real life your software is going to run for a few months
> consecutively.
> I was working for a WebKit-based browser for TVs for a software company
> and the browser kept crashing after a day of usage because of memory
> leaks. I mean how are you supposed to watch TV if you need to reboot the
> set-top box every day at a random time?
> Also do you really want to spend time running Valgrind on iPhones or
> Androids to find these problems? First Valgrind won't fix the problem,
> second it is not giving always the same answer and third it doesn't run
> on all embedded devices.
> There is more you can read about the subject here:
> "Real Production Issue - Hard to find memory leaks"
> https://www.linkedin.com/pulse/c-hard-find-memory-leaks-vidhut-singh
> And BTW:
> "Garbage collection is out the window, because you cannot know when it
> is going to happen or how long it will take, which leads to stuttering
> frame rates."
> https://www.quora.com/How-do-game-studios-prevent-memory-leaks-in-complex-C++-games
> > So bugs can have disastrous consequences, sure; but fixing all pointer
> > abuses won't stop that from being the case.  Meanwhile, in the world of
> > most programmers, most bugs are more or less endurable and most users
> > would sooner have something that ships today with a few endurable bugs
> > than not have the software that helps them do whatever it is they do
> > until someone is sure there are no bugs in it.  Buts aren't the only
> > thing that can cause a software project to fail.
> >
> >> Also it is possible for me to support nested structures by prefixing
> class
> >> names so that their meta-data fits into the top-level namespace but for
> the
> >> moment they’re not. But those are personal preferences like not using
> >> underscores in function names, etc.
> >
> > Well, if you can support nested structures, you might have a better
> > chance of persuading folk to port to your new language; but those with
> > large code-bases aren't about to re-write them to eliminate nested
> > structures just because you regard that choice as a personal preference.
> > I note that Qt has plenty of nested structures.
> > I'm not volunteering to refactor them away.
> Support for nested structures is easy to fix and will just take a day or
> two to do so. For example:
> struct A
> {
>    struct B
>    {
>    };
> };
> Will be converted into the following so that I can have their
> specialization in a top-level namespace:
> struct A__B
> {
> };
> struct A
> {
> };
This would break existing code, as name lookup from nested class should
visit first enclosing class before visiting namespace. Also, the nested
class must have access to all names (private, protected, etc) to which the
enclosing class has access (

Since there is no hidden catch then I will tell you right now that:
> - NULL C pointers will need to be typed
> - pointer casts to their encompassing structure needs to use
> _containerof() macro
> - C-style array parameters needs to be converted to pointers
What for ? you loose the size information by doing so.

> - Types instantiated in the same statement need not be different (Ex.:
> int * i, j[4]; // needs to be 2 different statements)
> That's about it. It took me 1 week to adapt "libarchive" to follow the
> aforementioned rules:
> https://github.com/philippeb8/libarchive/commit/5858b5c047301123ffdf05f247f7d191829d5a9b
> Regards,
> -Phil
> _______________________________________________
> Development mailing list
> Development at qt-project.org
> http://lists.qt-project.org/mailman/listinfo/development
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/development/attachments/20180425/be7406c1/attachment.html>

More information about the Development mailing list