Re: loslib.c warning

[David Jones <drj@...>]

Le 25 Sep 2006 à 06:23, Glenn Maynard a écrit :

> 55I just had to point this out, for irony; VC7 gives:
>
>    warning C4702: unreachable code
>
> for this bit of code:
>
>    exit(luaL_optint(L, 1, EXIT_SUCCESS));
>    return 0;  /* to avoid warnings */
>
> I'd recommend removing this; it's introducing a legitimate warning in
> order to fix a buggy one.

It entirely depends on what compiler one is using and what warnings  
you have enabled.

I happen to think there are entirely legitimate reasons for having  
unreachable code.  For example you might have an ASSERT macro:

ASSERT(spong);

In fast reckless builds you might want to disable the macro, but it's  
nice if the condition argument to the macro still gets fed through  
the compiler so that the compiler can report any syntax violations or  
semantic checks.  That means that a typo introduced into an ASSERT  
still gets caught when you do fast reckless builds.  Define your  
macro something like this:

#define ASSERT(x) if(1) {} else do { sizeof(x); } while(0)

This way the compiler still checks the condition for syntax, etc, but  
no code gets generated.  There's lots of unreachable and dead code.

I like the unreachable code warning, but it often annoys too.

drj