Re: NDEBUG when building packages?

[Mathieu Malaterre <malat@debian.org>]

On Fri, Feb 22, 2013 at 9:52 PM, Russ Allbery <rra@debian.org> wrote:
> Ian Jackson <ijackson@chiark.greenend.org.uk> writes:
>> Mathieu Malaterre writes ("Re: NDEBUG when building packages?"):
>
>>> In that case, this should really be clarified. A lot of debian/cmake
>>> packages are actually doing:
>
>>> -DCMAKE_BUILD_TYPE:STRING=Release
>
>>> within there debian/rules files. This settings by default compiles
>>> with: `-O3 -DNDEBUG`
>
>> OMG WTF BBQ
>
>> Certainly -DNDEBUG should never be used unless upstream explicitly say
>> that it's intended to be supported, and usually not even then.
>
> Also, -O3 is generally considered rather iffy.  It's not very well-tested
> and in various versions of GCC it tended to make the code slower, not
> faster (usually because it unrolled loops too far and blew the CPU cache).
> It's also had various code generation bugs from time to time.
>
> I wouldn't use -O3 without benchmarking of that specific code to confirm
> that it really improves matters.

Seems like everyone agreed. I'll report a bug to lintian package to
have it check for this string in d/rules:

http://codesearch.debian.net/search?q=DCMAKE_BUILD_TYPE:STRING%3DRelease

Thanks,