On Mon, Jun 18, 2012 at 7:12 AM, Joseph S. Myers
<jos...@codesourcery.com> wrote:
> On Mon, 18 Jun 2012, Steven Bosscher wrote:
>
>> For targets that do not define NO_IMPLICIT_EXTERN_C, GCC assumes that
>> included system headers are implicitly wrapped in 'extern "C" {...}'.
>> I could not find where this target macro was introduced, but it is
>> very old (it is already mentioned in FSFChangeLog.10 for a change in
>> 1995). AFAICT, today all supported targets have C++-compatible headers
>
> May have been introduced by:
>
> Fri Nov 5 05:48:04 1993 Richard Stallman (r...@mole.gnu.ai.mit.edu)
>
> * cccp.c (main): Handle NO_IMPLICIT_EXTERN_C.
>
>> (according to one comment, even hpux8 had C++-compatible system
>> headers :-), so NO_IMPLICIT_EXTERN_C shouldn't be necessary anymore.
>
> It was previously said that AIX headers needed it
> <http://gcc.gnu.org/ml/gcc/2005-05/msg00381.html>. That of course was AIX
> headers as of 2005; I don't know whether seven years later any version of
> AIX supported by GCC trunk still needs this.
Users continue to build recent versions of GCC on AIX 4.3, 5.1 and 5.2.
Recent versions of AIX may be C++-safe, but I do not know how to
verify that. Some headers have
extern "C" { } wrappers and other do not.
Thanks, David
