Wish: Variable Not Used Warning

[Koroskin Denis]

On Sun, 27 Jul 2008 17:56:01 +0400, Bruno Medeiros  
<brunodomedeiros+spam at com.gmail> wrote:

> Walter Bright wrote:
>> Nick Sabalausky wrote:
>>> I don't suppose there's any chance of DMD getting a warning for  
>>> variables/arguments that are declared but never accessed? Just today  
>>> alone there's been two bugs I spent 10-30 minutes going nuts trying to  
>>> track down that turned out to be variables I had intended to use but  
>>> forgot to.
>>  The problem with unused variable warnings is they are annoying when  
>> you're developing code in an iterative manner. They get in the way when  
>> you're commenting out sections of code to try and isolate a problem.  
>> They can be a problem when using "version" and "static if" statements.
>>  So, why not just turn off the warnings?
>>  The problem with warnings is that if there are n warnings, there are  
>> essentially n factorial different versions of the language. If you're  
>> faced with compiling someone else's code (like you downloaded it off  
>> the internet and have to compile it because it only is distributed as  
>> source) and warnings go off, is that a bug in the code or not? What do  
>> you do?
>>
>
> You have a distorted notion of warnings. Warnings are not errors (and by  
> corollary are not "optional errors" also). They are simply messages  
> which indicate some "strange" situations in code, which suggest some  
> attention from the developer (now or in the future).
> That's why other compilers have an *option* such as  
> "treat-warnings-as-errors". If they were errors, they wouldn't need that  
> option, cause they would already be treated as errors (cause they would  
> *be* errors...), lol. :(
>
> You (Walter) and other people, may be inclined to disagree, especially  
> if you are heavily biased torwards C++, where warnings, like you said,  
> have been used for *things that should have been errors*, and have  
> created this whole messed up and confused situations, and scenarios  
> where people think C++ code should compile without errors, etc., etc..  
> But that is just a scenario arising from C++ fucked-up-ness.
>
> If you (and others) still don't agree, which you probably won't, then  
> let's not argue semantics, and just call this notion of warnings that I  
> defined before as "cautions".
> _ With this in mind, what's wrong with the compiler generating messages  
> (and just messages, not errors) for certain suspicious code situations,  
> such as unused variables? Just that, what do you say? _
>
>

Now I agree with Walter on that matter. Compiler's job is to compile an  
executable. As a gentoo user when I compile something (and I do it alot :p  
) I expect two messages: "build finished" *or* "build failed for the  
following reason: ...". All those warning are *not for me*, they are for  
developers and needed during development time only. Imagine you are  
updating a web-browser or some other application and get all those  
"comparison between signed and unsigned types" messages. Do you want to  
read them?

OTOH, I want for my code to be constantly analyzed for suspicious  
situation but _only during development time_. That's why I use IDE. And my  
IDE should help me as I type: syntax highlighting, code autocomplete,  
refactoring *and* warnings. It's almost free for IDE to analyze my code  
for possible errors. But compiler's job is to compile *or* reject the  
code, and it should do it as fast as possible without spending time for  
looking into suspicious situations.

Compiler and IDE tasks do often overlap, of course, but it doesn't mean  
that they should be merged into single solution.

Just my $0.02...