Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups: comp.lang.c
Subject: Re: Concatenated if and preprocessor
Date: Fri, 14 Mar 2025 14:10:28 -0700
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Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
> Richard Harnden <richard.nospam@gmail.invalid> writes:
>> On 14/03/2025 16:44, Tim Rentsch wrote:
>>>    for(  int just_once = 1;  just_once;  just_once = 0  ){
>>
>> Any reason not to say ...
>>
>> do {
>>     ...
>> } while (0);
>>
>> ... ?
>
> In fact using do/while(0) is what I first wrote.  But then
> I thought, oh wait, what if an overzealous compiler gives
> a warning because the while() expression is always false? :-/
>
> It's because of examples like this that I am wary of rules
> like "enable all warnings" and "treat any warning condition
> as an error."  I recently ran across a set of coding standard
> rules that included these rules:  not just /some/ warning
> conditions, but ALL warning conditions.  I still don't know
> if they were literally serious.  (And my understanding is
> clang has a -Weverything option, which enables all warning
> conditions that clang is able to test for, no matter how
> silly.)

I've worked under such coding standards.  Perhaps surprisingly, I
haven't found them to be terribly inconvenient.  I rarely ran into
a warning that was inordinately difficult to avoid.   I can see that
"clang -Weverything" would cause problems.

The most common inconvenience was that if I experimentally commented
out some code, and it caused some variable not to be referenced,
the build would fail.  (I could just add `(void)foo;` to avoid that.)
To be clear, this was not code that I intended to commit.

I can imagine that there could be problems if a newer version of the
compiler produced new warnings, but we didn't often change compilers.

(In one obscure case, I wrote a wrapper script that could be
installed in $PATH as "gcc" that would invoke the real gcc and
filter out a particular warning.  The wrapper was necessary due to
the behavior of a build script, not to an explicit coding standard.)

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */