Re: Lists and aliasing (Re: Freeze on 27 February)

[Lennart Sorensen]

On Wed, Feb 22, 2012 at 01:28:06PM -0500, Lennart Sorensen wrote:
> Oh the feature for doing multiple #pragma statements throughout the code
> is new in gcc 4.6.  It can't be done in earlier versions.  In older
> versions whatever you say last applies to the whole file.
> 
> Perhaps a slightly ugly solution could solve it by having a #if that
> checks that gcc is 4.6 or higher around the #pragma that reenables
> the warning.
> 
> ie:
> 
> #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
> #pragma GCC diagnostic error "-Wunsafe-loop-optimizations"
> #endif
> 
> At least this way you get to have the warning for most of the code on
> newer gcc versions, but don't break older gcc versions that are still
> in common use.

Well it compiles when I do that at least with gcc 4.4, although obviously
it does mean -Wunsafe-loop-optimizations is disabled entirely for those
4 files rather than just for the one function that causes a problem.

-- 
Len Sorensen