Trying to understand nested loops

[Richard Damon]

On 8/6/22 8:12 AM, Chris Angelico wrote:
> On Sat, 6 Aug 2022 at 22:08, Richard Damon <Richard at damon-family.org> wrote:
>> On 8/6/22 12:01 AM, Chris Angelico wrote:
>>> On Sat, 6 Aug 2022 at 13:54, Dan Stromberg <drsalists at gmail.com> wrote:
>>>> On Fri, Aug 5, 2022 at 12:54 PM Grant Edwards <grant.b.edwards at gmail.com>
>>>> wrote:
>>>>
>>>>> In C, this doesn't do what it looks like it's supposed to do.
>>>>>
>>>>>      if (foo)
>>>>>        do_this();
>>>>>        and_this();
>>>>>      then_do_this();
>>>>>
>>>> It's been quite a while since I used C, but with the right compiler
>>>> flag(s), I think this may be a thing of the past when compiling with gcc:
>>>> https://developers.redhat.com/blog/2016/02/26/gcc-6-wmisleading-indentation-vs-goto-fail
>>> Ah yes, because compiler warnings are always viewed and acted upon.
>>>
>>> Have you ever watched the compilation of a large open-source project,
>>> done using the project's own build system and therefore the team's
>>> preferred warning settings? It's normal to have such a spew of
>>> warnings that you can't find anything interesting, or to have new
>>> warnings in new versions of GCC be utterly useless for the same
>>> reason.
>>>
>>> ChrisA
>> You make it so you HAVE to fix the warning by adding the option to make
>> warnings into errors.
>>
>> This does mean that you need to fix all the warnings that don't actually
>> mean anything,
>>
>> Good code shouldn't generate many warnings, either you have warnings
>> enabled that you don't care about, or your code is doing things you have
>> told the complier you shouldn't do.
>>
> I say again: have you ever watched the compilation of a large
> open-source project? You cannot turn warnings into errors, because
> there are ALWAYS warnings. Maybe, once upon a time, the policy was to
> ensure that there were no warnings on any major compiler; but times
> change, compilers add new warnings, new compilers join the club, and
> it becomes practically impossible to prevent warnings. Which, in turn,
> makes all warnings basically meaningless.
>
> Hmm. I don't think I've ever compiled gcc from source. Maybe I should
> do that, just to see whether gcc itself compiles with no warnings
> under gcc.
>
> ChrisA

And for any project, that is a choice THEY made.

For projects where code quality is actually a defined metric, there is 
normally a specified warning level (for a specified set of compilers and 
versions) that the code needs to compile at least nearly clean at.

Yes, you can get that ton of warnings when at a higher warning level, 
but that is why you specify the warning level to use, and put the 
specific mitigations/suppressions for the few cases where the code is 
correct, but generates that warning.

Yes, you can get a lot of warnings with another compiler, but that is 
because you aren't running at the correct warning level for that 
compiler, which is why the set of compilers that you are "warning free" 
on is specified. When you add a new compiler, it may first not be 
warning free until you make the effort (if you ever do) to make it 
warning free for that.

Major open source projects will have a "toll gate" on the official 
repository that checks that additions keep the code to the standard it 
has established,

-- 
Richard Damon