[PATCH] Clean CPLUSPLUS_CPP_SPEC _GNU_SOURCE for GNU STL implementation targets.

[Mark Mitchell]

Marcin Dalecki wrote:

> In my understanding according to the glibc documentation, the flag in 
> question
> is used to select the system-personality (in linux) parlance of the  glibc.
> It is a conscious decision to be made by the user. Why should linux  be
> different
> from all other systems in a very subtile and not transparent way in  first
> place at all? 

Yes, that's why I said your change would be desirable.

However, the reason that we define _GNU_SOURCE is that, at least
historically, some of libstdc++ made use of the GLIBC extensions, not
just when building libstdc++ but when *using* it; for example, there
were inline functions that made use of GLIBC extensions.  The correct
fix might be to move functions that use the GLIBC extensions
out-of-line, when _GNU_SOURCE is not defined, so that users could still
use the functions, albeit with a performance penalty.

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713