[Python-Dev] PEP 3146: Merge Unladen Swallow into CPython

[Collin Winter]

To follow up on some of the open issues:

On Wed, Jan 20, 2010 at 2:27 PM, Collin Winter <collinwinter at google.com> wrote:
[snip]
> Open Issues
> ===========
>
> - *Code review policy for the ``py3k-jit`` branch.* How does the CPython
>  community want us to procede with respect to checkins on the ``py3k-jit``
>  branch? Pre-commit reviews? Post-commit reviews?
>
>  Unladen Swallow has enforced pre-commit reviews in our trunk, but we realize
>  this may lead to long review/checkin cycles in a purely-volunteer
>  organization. We would like a non-Google-affiliated member of the CPython
>  development team to review our work for correctness and compatibility, but we
>  realize this may not be possible for every commit.

The feedback we've gotten so far is that at most, only larger, more
critical commits should be sent for review, while most commits can
just go into the branch. Is that broadly agreeable to python-dev?

> - *How to link LLVM.* Should we change LLVM to better support shared linking,
>  and then use shared linking to link the parts of it we need into CPython?

The consensus has been that we should link shared against LLVM.
Jeffrey Yasskin is now working on this in upstream LLVM. We are
tracking this at
http://code.google.com/p/unladen-swallow/issues/detail?id=130 and
http://llvm.org/PR3201.

> - *Prioritization of remaining issues.* We would like input from the CPython
>  development team on how to prioritize the remaining issues in the Unladen
>  Swallow codebase. Some issues like memory usage are obviously critical before
>  merger with ``py3k``, but others may fall into a "nice to have" category that
>  could be kept for resolution into a future CPython 3.x release.

The big-ticket items here are what we expected: reducing memory usage
and startup time. We also need to improve profiling options, both for
oProfile and cProfile.

> - *Create a C++ style guide.* Should PEP 7 be extended to include C++, or
>  should a separate C++ style PEP be created? Unladen Swallow maintains its own
>  style guide [#us-styleguide]_, which may serve as a starting point; the
>  Unladen Swallow style guide is based on both LLVM's [#llvm-styleguide]_ and
>  Google's [#google-styleguide]_ C++ style guides.

Any thoughts on a CPython C++ style guide? My personal preference
would be to extend PEP 7 to cover C++ by taking elements from
http://code.google.com/p/unladen-swallow/wiki/StyleGuide and the LLVM
and Google style guides (which is how we've been developing Unladen
Swallow). If that's broadly agreeable, Jeffrey and I will work on a
patch to PEP 7.

Thanks,
Collin Winter