PATCH RFA: Build stages 2 and 3 with C++

[Richard Guenther]

On Sun, Jul 17, 2011 at 12:57 AM, Ian Lance Taylor <iant@google.com> wrote:
> Diego Novillo <dnovillo@google.com> writes:
>
>> On Sat, Jul 16, 2011 at 02:52, Ian Lance Taylor <iant@google.com> wrote:
>>
>>> 2011-07-15  Ian Lance Taylor  <iant@google.com>
>>>
>>>        * configure.ac: Add --enable-build-poststage1-with-cxx.  If set,
>>>        make C++ a boot_language.  Set and substitute
>>>        POSTSTAGE1_CONFIGURE_FLAGS.
>>>        * Makefile.tpl (POSTSTAGE1_CONFIGURE_FLAGS): New variable.
>>>        (STAGE[+id+]_CONFIGURE_FLAGS): Add $(POSTSTAGE1_CONFIGURE_FLAGS).
>>>        * configure, Makefile.in: Rebuild.
>>
>> I agree with this change.

I agree with this change as well.  It will give us  the opportunity to
experience
debugging a C++ built cc1 ...

>>  For reference, have you measured the
>> difference in bootstrap time?  Clearly, it will be slower, but how
>> much?
>
> I have not measured the change in bootstrap time, no.

I have measured it at some point and IIRC it was about 10% slower
(comparing C bootstrap with C++ in stag1 languages with C++ bootstrap,
not sure if that included bootstrapping libstdc++ for the former).

Richard.

> Ian
>