Re: Use gen-libm-test.py to generate ulps table for manual

[Zack Weinberg <zackw at panix dot com>]

On Tue, Sep 4, 2018 at 10:30 AM Joseph Myers <joseph@codesourcery.com> wrote:
> On Tue, 4 Sep 2018, Andreas Schwab wrote:
>
> > On Sep 04 2018, Zack Weinberg <zackw@panix.com> wrote:
> >
> > > On Tue, Sep 4, 2018 at 9:34 AM Andreas Schwab <schwab@suse.de> wrote:
> > >>
> > >> I withdraw my objection, under the condition that the use of python is
> > >> restricted to the base python language.
> > >
> > > Can you define "base python language" more precisely, please?
> >
> > Basically what is part of the openSUSE python3-base package.
>
> Based on the description at
> <https://software.opensuse.org/package/python3-base> I've updated
> <https://sourceware.org/glibc/wiki/Style_and_Conventions> to say:
>
>  * Scripts used in the build of glibc (a standard {{{make}}}, possibly
> regenerating files in the source tree if timestamps are out of order and
> the dependencies are present in the normal makefiles) need to avoid
> modules outside the Python standard library, and standard library modules
> depending on external libraries (such as XML, database and UI libraries).

The Debian equivalent, (lib)python2.7-minimal, has a README with an
exact list of modules that may be used.  This appears to be a subset
of the stuff in SUSE's python3-base  I've reproduced the contents of
that file (from unstable; specifically, 2.7.15-3_amd64.deb) below.

If SUSE has already gotten to the point where Python 2 is not part of
their bootstrap, maybe we should ditch Python 2 now rather than
waiting for its EOL.  Debian currently has both python2.7-minimal and
python3.6-minimal packages.  The sets of standard library modules
available from each appear to be roughly the same, after accounting
for all the Python 3 module renames.

May I additionally suggest that it's not obvious that this stuff is
documented under "Code formatting in python sources", and the section
should be renamed to indicate it's general policy for Python usage?

zw

----

Contents of the python2.7-minimal package
-----------------------------------------

python2.7-minimal consists of a minimum set of modules which may be needed
for python scripts used during the boot process.  If other packages
are needed in these scripts, don't work around the missing module, but
file a bug report against this package. The modules in this package
are:

  __builtin__        builtin
  __future__        module
  _abcoll        module
  _bisect        extension
  _bytesio        extension
  _codecs        builtin
  _collections        extension
  _fileio        extension
  _functools        extension
  _hashlib        extensionx
  _heapq        extension
  _io            extension
  _locale        extension
  _md5            extension
  _random        extension
  _sha            extension
  _sha256        extension
  _sha512        extension
  _socket        extension
  _sre            builtin
  _ssl            extensionx
  _struct        extension
  _symtable        builtin
  _sysconfigdata    module
  _types        builtin
  _warnings        builtin
  _weakref        extension
  _weakrefset        module
  abc            module
  atexit        module
  ConfigParser        module
  StringIO        module
  UserDict        module
  cPickle        extension
  cStringIO        extension
  array            extension
  base64        module
  binascii        extension
  bisect        module
  cmath            extension
  calendar        module
  codecs        module
  collections        module
  compileall        module
  contextlib        module
  copy            module
  copy_reg        module
  datetime        extension
  dis            module
  encodings        package
  errno            builtin
  exceptions        builtin
  fcntl            extension
  fnmatch        module
  functools        module
  gc            builtin
  genericpath        module
  getopt        module
  glob            module
  grp            extension
  hashlib        module
  heapq            module
  imp            builtin
  inspect        module
  io            module
  itertools        extension
  keyword        module
  linecache        module
  locale        module
  logging        package
  marshal        builtin
  math            extension
  md5            module
  opcode        module
  operator        extension
  optparse        module
  os            module
  pickle        module
  platform        module
  popen2        module
  posix            builtin
  posixpath        module
  pkgutil        module
  pwd            builtin
  py_compile        module
  random        module
  re            module
  repr            module
  runpy            module
  select        extension
  sha            module
  shutil        module
  signal        builtin
  socket        module
  spwd            extension
  sre            module
  sre_compile        module
  sre_constants        module
  sre_parse        module
  ssl            module
  stat            module
  string        module
  strop            extension
  struct        module
  subprocess        module
  sys            builtin
  syslog        extension
  sysconfig        module
  tempfile        module
  textwrap        module
  time            extension
  token            module
  thread        builtin
  token            module
  tokenize        module
  traceback        module
  types            module
  unicodedata        extension
  weakref        module
  warnings        module
  zipimport        extension
  zlib            extension

Included are as well the codecs and stringprep modules, and the encodings
modules for all encodings except the multibyte encodings and the bz2 codec.

The following modules are excluded, their import is guarded from the
importing module:

  Used in       Excluded
  ------------  ------------------------------------
  os        nt ntpath os2 os2emxpath mac macpath
        riscos riscospath riscosenviron
  optparse    gettext
  pickle    doctest
  subprocess    threading

This list was derived by looking at the modules in the perl-base package,
then adding python specific "core modules".

TODO's
------

- time.strptime cannot be used. The required _strptime module is not
  included in the -minimal package yet. _strptime, locale, _locale and
  calendar have to be added.

- modules used very often in the testsuite: copy, cPickle, operator.