[patch] Enable lightweight checks with _GLIBCXX_ASSERTIONS.

[Florian Weimer]

On 09/10/2015 06:57 PM, Martin Sebor wrote:

>>> There is quite a bit of documentation of _FORTIFY_SOURCE that explains
>>> its effect on user code.
>>
>> I think there are only random blog articles discussing aspects of it,
>> most of them slightly incorrect or outdated.
> 
> _FORTIFY_SOURCE is a GLIBC feature test macro. It's documented
> in <features.h> and mentioned in some of its online manuals.
> For example:
> 
> http://man7.org/linux/man-pages/man7/feature_test_macros.7.html
> 
> or here:
> 
> http://manpages.ubuntu.com/manpages/hardy/man7/feature_test_macros.7.html

Oh, so there is an out-dated man-page as well. :-/

The fd_set checks added in glibc 2.15 are missing.  That caused some
backslash because some folks were actually abusing FD_SET and related
macros.  Nothing too severe, and in the end, we stood our ground.  I
expect the libstdc++ changes to be similar.

Again, my main argument is that the main users of _FORTIFY_SOURCE are
distributions, and they would inject whatever preprocessor macro enables
the new libstdc++ checks anyway, so saving them that work would be
preferable IMHO.

-- 
Florian Weimer / Red Hat Product Security