seeking deeper (language theory) reason behind Python design choice

[Chris Angelico]

On Sun, May 13, 2018 at 9:05 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> On Sat, 12 May 2018 21:42:13 -0500, Python wrote:
>
>> Responding to this further would essentially just require me to
>> reiterate what I already wrote--I won't do that.  I'll simply maintain
>> that in my rather lenghty experience, this mistake has actually been
>> rather rare and has to my knowledge *never* caused a support issue
>> requiring a bug fix to production code in projects I've been associated
>> with.  It's a useful construction whose detriment has, IMO, been
>> completely overblown.
>
> I already linked to the attempt to install a backdoor in the Linux kernel
> with this, but even for accidental errors, thirty seconds on the CVE
> database finds at least one real-world example:
>
> https://www.cvedetails.com/cve/CVE-2009-4633/
>
>
> I expect that these days it will be rare, since most C compilers would
> default to warning about it if you run with warnings enabled.
>

That assumes that you regularly run with warnings enabled. While that
might seem like a no-brainer, unfortunately it isn't. With the number
of C compilers out there, it's hard to make sure your code compiles
cleanly with -Wall on every one of them; and if there's a spew of
warnings, one more isn't going to be noticed. So for a large codebase,
it's entirely possible that it WON'T regularly be compiled with
warnings enabled.

Warnings certainly help, but they're not a complete solution.

ChrisA