PATCH: (kind of) to improve support for libc++ with libsupc++

[Howard Hinnant]

On Sep 25, 2013, at 2:40 PM, Chandler Carruth <chandlerc at google.com> wrote:

> 
>> On Wed, Sep 25, 2013 at 2:34 PM, Howard Hinnant <howard.hinnant at gmail.com> wrote:

>> Background:  libcxx used to define these symbols.  We are in the middle of migrating them from libcxx to libcxxabi, and for now we need to support both places (while in this transition period).  I would suggest #ifdef-ing on something that only will be defined in the environment where these symbols are causing a problem (users of libsupc++).  I don't know what the #ifdef will be for that environment.  But on some of my platforms of interest _LIBCPPABI_VERSION will not be defined, and I will need the symbols inside of that #ifdef (on the front side of this transition period).
>> 
>> A couple of years from now, then we can probably get rid of this file.
>> 
> Cool. The macro is __GLIBXX__, I can make the #if here look exactly like that in src/exception.cpp:
> 45:#if !defined(LIBCXXRT) && !defined(_LIBCPPABI_VERSION) && !defined(__GLIBCXX__)

Thanks much!

Howard