Re: Introductory Presentations, especially aimed at C++ programmers!

["Randy Brukardt" <randy@rrsoftware.com>]

"Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org> wrote in message 
news:o29kmm$mt7$1@dont-email.me...
> On 12/07/2016 10:44 AM, Luke A. Guest wrote:
>>
>> And shoot down the bullshit argument if "any good Programmer wouldn't 
>> make
>> that mistake" because it can happen to anyone.
>
> Examine the change logs of long-lived, open-source, C++ projects, 
> especially those that communicate over the internet, like Firefox, and 
> you'll find lots of fixes for buffer overflows and signed integer 
> overflows, same as with C: things that are impossible in a well designed 
> language. The proportion of such errors doesn't seem to decrease with 
> time, either, so they are continuing to create new errors even as they 
> patch the old ones. We have decades of experience with these languages 
> that show beyond the shadow of a doubt that it is impossible for humans to 
> write code in them without making such errors.

To be fair, though, such things can happen in Ada, too. Case in point: 
something that happened to me today.

A customer had what appears to be a permissions problem installing 
Janus/Ada, so before contacting us, they tried an uninstall. The uninstaller 
crashed. I asked them to send me the exact message, and it proved to be 
overflow error in Claw.Registry. Tracking that down showed that the buffer 
for reading a registry variable (so stuff could be removed from it) wasn't 
big enough. Of course, Ada detected the error and crashed, but that's only 
an iota better than what would have happened in C (the uninstaller didn't do 
its job either way).

The problem seemed familar, and it turns out that I had a similar problem in 
the installer a few years back. And I had increased the buffer size in the 
installer program back then. But I failed to increase the buffer size in the 
separate uninstaller program. A rookie mistake. After 35 years of Ada 
programming. (You may argue precisely what the rookie mistake was, but 
surely there is one here.)

Yet another data point that no one is immune from making silly errors, in 
any language. It at least helps to have a language where the culture is to 
detect rather than ignore errors (and especially when customers think the 
same way, allowing a more rapid squashing of bugs).

                                           Randy.