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<h1>Python Enhancement Proposals</h1>
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<h1 class="page-title">PEP 3149 – ABI version tagged .so files</h1>
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<dl class="rfc2822 field-list simple">
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<dt class="field-odd">Author<span class="colon">:</span></dt>
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<dd class="field-odd">Barry Warsaw <barry at python.org></dd>
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<dt class="field-even">Status<span class="colon">:</span></dt>
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<dd class="field-even"><abbr title="Accepted and implementation complete, or no longer active">Final</abbr></dd>
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<dt class="field-odd">Type<span class="colon">:</span></dt>
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<dd class="field-odd"><abbr title="Normative PEP with a new feature for Python, implementation change for CPython or interoperability standard for the ecosystem">Standards Track</abbr></dd>
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<dt class="field-even">Created<span class="colon">:</span></dt>
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<dd class="field-even">09-Jul-2010</dd>
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<dt class="field-odd">Python-Version<span class="colon">:</span></dt>
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<dd class="field-odd">3.2</dd>
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<dt class="field-even">Post-History<span class="colon">:</span></dt>
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<dd class="field-even">14-Jul-2010, 22-Jul-2010</dd>
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<dt class="field-odd">Resolution<span class="colon">:</span></dt>
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<dd class="field-odd"><a class="reference external" href="https://mail.python.org/pipermail/python-dev/2010-September/103408.html">Python-Dev message</a></dd>
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</dl>
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<hr class="docutils" />
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<section id="contents">
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<details><summary>Table of Contents</summary><ul class="simple">
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<li><a class="reference internal" href="#abstract">Abstract</a></li>
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<li><a class="reference internal" href="#background">Background</a></li>
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<li><a class="reference internal" href="#rationale">Rationale</a></li>
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<li><a class="reference internal" href="#proposal">Proposal</a></li>
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<li><a class="reference internal" href="#proven-approach">Proven approach</a></li>
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<li><a class="reference internal" href="#windows">Windows</a></li>
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<li><a class="reference internal" href="#pep-384">PEP 384</a></li>
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<li><a class="reference internal" href="#alternatives">Alternatives</a><ul>
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<li><a class="reference internal" href="#independent-directories-or-symlinks">Independent directories or symlinks</a></li>
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<li><a class="reference internal" href="#don-t-share-packages-with-extension-modules">Don’t share packages with extension modules</a></li>
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</ul>
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</li>
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<li><a class="reference internal" href="#reference-implementation">Reference implementation</a></li>
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<li><a class="reference internal" href="#references">References</a></li>
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<li><a class="reference internal" href="#copyright">Copyright</a></li>
|
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</ul>
|
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</details></section>
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<section id="abstract">
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<h2><a class="toc-backref" href="#abstract" role="doc-backlink">Abstract</a></h2>
|
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<p><a class="pep reference internal" href="../pep-3147/" title="PEP 3147 – PYC Repository Directories">PEP 3147</a> described an extension to Python’s import machinery that
|
||
improved the sharing of Python source code, by allowing more than one
|
||
byte compilation file (.pyc) to be co-located with each source file.</p>
|
||
<p>This PEP defines an adjunct feature which allows the co-location of
|
||
extension module files (.so) in a similar manner. This optional,
|
||
build-time feature will enable downstream distributions of Python to
|
||
more easily provide more than one Python major version at a time.</p>
|
||
</section>
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<section id="background">
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<h2><a class="toc-backref" href="#background" role="doc-backlink">Background</a></h2>
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<p><a class="pep reference internal" href="../pep-3147/" title="PEP 3147 – PYC Repository Directories">PEP 3147</a> defined the file system layout for a pure-Python package,
|
||
where multiple versions of Python are available on the system. For
|
||
example, where the <code class="docutils literal notranslate"><span class="pre">alpha</span></code> package containing source modules <code class="docutils literal notranslate"><span class="pre">one.py</span></code>
|
||
and <code class="docutils literal notranslate"><span class="pre">two.py</span></code> exist on a system with Python 3.2 and 3.3, the post-byte
|
||
compilation file system layout would be:</p>
|
||
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">alpha</span><span class="o">/</span>
|
||
<span class="n">__pycache__</span><span class="o">/</span>
|
||
<span class="fm">__init__</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="mf">32.</span><span class="n">pyc</span>
|
||
<span class="fm">__init__</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="mf">33.</span><span class="n">pyc</span>
|
||
<span class="n">one</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="mf">32.</span><span class="n">pyc</span>
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||
<span class="n">one</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="mf">33.</span><span class="n">pyc</span>
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||
<span class="n">two</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="mf">32.</span><span class="n">pyc</span>
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||
<span class="n">two</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="mf">33.</span><span class="n">pyc</span>
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||
<span class="fm">__init__</span><span class="o">.</span><span class="n">py</span>
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||
<span class="n">one</span><span class="o">.</span><span class="n">py</span>
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||
<span class="n">two</span><span class="o">.</span><span class="n">py</span>
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||
</pre></div>
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||
</div>
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||
<p>For packages with extension modules, a similar differentiation is
|
||
needed for the module’s .so files. Extension modules compiled for
|
||
different Python major versions are incompatible with each other due
|
||
to changes in the ABI. Different configuration/compilation options
|
||
for the same Python version can result in different ABIs
|
||
(e.g. –with-wide-unicode).</p>
|
||
<p>While <a class="pep reference internal" href="../pep-0384/" title="PEP 384 – Defining a Stable ABI">PEP 384</a> defines a stable ABI, it will minimize, but not
|
||
eliminate extension module incompatibilities between Python builds or
|
||
major versions. Thus a mechanism for discriminating extension module
|
||
file names is proposed.</p>
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||
</section>
|
||
<section id="rationale">
|
||
<h2><a class="toc-backref" href="#rationale" role="doc-backlink">Rationale</a></h2>
|
||
<p>Linux distributions such as Ubuntu <a class="footnote-reference brackets" href="#id9" id="id1">[3]</a> and Debian <a class="footnote-reference brackets" href="#id10" id="id2">[4]</a> provide more
|
||
than one Python version at the same time to their users. For example,
|
||
Ubuntu 9.10 Karmic Koala users can install Python 2.5, 2.6, and 3.1,
|
||
with Python 2.6 being the default.</p>
|
||
<p>In order to share as much as possible between the available Python
|
||
versions, these distributions install third party package modules
|
||
(<code class="docutils literal notranslate"><span class="pre">.pyc</span></code> and <code class="docutils literal notranslate"><span class="pre">.so</span></code> files) into <code class="docutils literal notranslate"><span class="pre">/usr/share/pyshared</span></code> and symlink to
|
||
them from <code class="docutils literal notranslate"><span class="pre">/usr/lib/pythonX.Y/dist-packages</span></code>. The symlinks exist
|
||
because in a pre-<a class="pep reference internal" href="../pep-3147/" title="PEP 3147 – PYC Repository Directories">PEP 3147</a> world (i.e < Python 3.2), the <code class="docutils literal notranslate"><span class="pre">.pyc</span></code> files
|
||
resulting from byte compilation by the various installed Pythons will
|
||
name collide with each other. For Python versions >= 3.2, all
|
||
pure-Python packages can be shared, because the <code class="docutils literal notranslate"><span class="pre">.pyc</span></code> files will no
|
||
longer cause file system naming conflicts. Eliminating these symlinks
|
||
makes for a simpler, more robust Python distribution.</p>
|
||
<p>A similar situation arises with shared library extensions. Because
|
||
extension modules are typically named <code class="docutils literal notranslate"><span class="pre">foo.so</span></code> for a <code class="docutils literal notranslate"><span class="pre">foo</span></code> extension
|
||
module, these would also name collide if <code class="docutils literal notranslate"><span class="pre">foo</span></code> was provided for more
|
||
than one Python version.</p>
|
||
<p>In addition, because different configuration/compilation options for
|
||
the same Python version can cause different ABIs to be presented to
|
||
extension modules. On POSIX systems for example, the configure
|
||
options <code class="docutils literal notranslate"><span class="pre">--with-pydebug</span></code>, <code class="docutils literal notranslate"><span class="pre">--with-pymalloc</span></code>, and
|
||
<code class="docutils literal notranslate"><span class="pre">--with-wide-unicode</span></code> all change the ABI. This PEP proposes to
|
||
encode build-time options in the file name of the <code class="docutils literal notranslate"><span class="pre">.so</span></code> extension
|
||
module files.</p>
|
||
<p>PyPy <a class="footnote-reference brackets" href="#id11" id="id3">[5]</a> can also benefit from this PEP, allowing it to avoid name
|
||
collisions in extension modules built for its API, but with a
|
||
different <code class="docutils literal notranslate"><span class="pre">.so</span></code> tag.</p>
|
||
</section>
|
||
<section id="proposal">
|
||
<h2><a class="toc-backref" href="#proposal" role="doc-backlink">Proposal</a></h2>
|
||
<p>The configure/compilation options chosen at Python interpreter
|
||
build-time will be encoded in the shared library file name for
|
||
extension modules. This “tag” will appear between the module base
|
||
name and the operation file system extension for shared libraries.</p>
|
||
<p>The following information <em>MUST</em> be included in the shared library
|
||
file name:</p>
|
||
<ul class="simple">
|
||
<li>The Python implementation (e.g. cpython, pypy, jython, etc.)</li>
|
||
<li>The interpreter’s major and minor version numbers</li>
|
||
</ul>
|
||
<p>These two fields are separated by a hyphen and no dots are to appear
|
||
between the major and minor version numbers. E.g. <code class="docutils literal notranslate"><span class="pre">cpython-32</span></code>.</p>
|
||
<p>Python implementations <em>MAY</em> include additional flags in the file name
|
||
tag as appropriate. For example, on POSIX systems these flags will
|
||
also contribute to the file name:</p>
|
||
<ul class="simple">
|
||
<li><code class="docutils literal notranslate"><span class="pre">--with-pydebug</span></code> (flag: <code class="docutils literal notranslate"><span class="pre">d</span></code>)</li>
|
||
<li><code class="docutils literal notranslate"><span class="pre">--with-pymalloc</span></code> (flag: <code class="docutils literal notranslate"><span class="pre">m</span></code>)</li>
|
||
<li><code class="docutils literal notranslate"><span class="pre">--with-wide-unicode</span></code> (flag: <code class="docutils literal notranslate"><span class="pre">u</span></code>)</li>
|
||
</ul>
|
||
<p>By default in Python 3.2, <code class="docutils literal notranslate"><span class="pre">configure</span></code> enables <code class="docutils literal notranslate"><span class="pre">--with-pymalloc</span></code> so
|
||
shared library file names would appear as <code class="docutils literal notranslate"><span class="pre">foo.cpython-32m.so</span></code>.
|
||
When the other two flags are also enabled, the file names would be
|
||
<code class="docutils literal notranslate"><span class="pre">foo.cpython-32dmu.so</span></code>.</p>
|
||
<p>The shared library file name tag is used unconditionally; it cannot be
|
||
changed. The tag and extension module suffix are available through
|
||
the <code class="docutils literal notranslate"><span class="pre">sysconfig</span></code> modules via the following variables:</p>
|
||
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">sysconfig</span><span class="o">.</span><span class="n">get_config_var</span><span class="p">(</span><span class="s1">'EXT_SUFFIX'</span><span class="p">)</span>
|
||
<span class="go">'.cpython-32mu.so'</span>
|
||
<span class="gp">>>> </span><span class="n">sysconfig</span><span class="o">.</span><span class="n">get_config_var</span><span class="p">(</span><span class="s1">'SOABI'</span><span class="p">)</span>
|
||
<span class="go">'cpython-32mu'</span>
|
||
</pre></div>
|
||
</div>
|
||
<p>Note that <code class="docutils literal notranslate"><span class="pre">$SOABI</span></code> contains just the tag, while <code class="docutils literal notranslate"><span class="pre">$EXT_SUFFIX</span></code> includes the
|
||
platform extension for shared library files, and is the exact suffix
|
||
added to the extension module name.</p>
|
||
<p>For an arbitrary package <code class="docutils literal notranslate"><span class="pre">foo</span></code>, you might see these files when the
|
||
distribution package was installed:</p>
|
||
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="o">/</span><span class="n">usr</span><span class="o">/</span><span class="n">lib</span><span class="o">/</span><span class="n">python</span><span class="o">/</span><span class="n">foo</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="mi">32</span><span class="n">m</span><span class="o">.</span><span class="n">so</span>
|
||
<span class="o">/</span><span class="n">usr</span><span class="o">/</span><span class="n">lib</span><span class="o">/</span><span class="n">python</span><span class="o">/</span><span class="n">foo</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="mi">33</span><span class="n">m</span><span class="o">.</span><span class="n">so</span>
|
||
</pre></div>
|
||
</div>
|
||
<p>(These paths are for example purposes only. Distributions are free to
|
||
use whatever filesystem layout they choose, and nothing in this PEP
|
||
changes the locations where from-source builds of Python are
|
||
installed.)</p>
|
||
<p>Python’s dynamic module loader will recognize and import shared
|
||
library extension modules with a tag that matches its build-time
|
||
options. For backward compatibility, Python will also continue to
|
||
import untagged extension modules, e.g. <code class="docutils literal notranslate"><span class="pre">foo.so</span></code>.</p>
|
||
<p>This shared library tag would be used globally for all distutils-based
|
||
extension modules, regardless of where on the file system they are
|
||
built. Extension modules built by means other than distutils would
|
||
either have to calculate the tag manually, or fallback to the
|
||
non-tagged <code class="docutils literal notranslate"><span class="pre">.so</span></code> file name.</p>
|
||
</section>
|
||
<section id="proven-approach">
|
||
<h2><a class="toc-backref" href="#proven-approach" role="doc-backlink">Proven approach</a></h2>
|
||
<p>The approach described here is already proven, in a sense, on Debian
|
||
and Ubuntu system where different extensions are used for debug builds
|
||
of Python and extension modules. Debug builds on Windows also already
|
||
use a different file extension for dynamic libraries, and in fact
|
||
encoded (in a different way than proposed in this PEP) the Python
|
||
major and minor version in the <code class="docutils literal notranslate"><span class="pre">.dll</span></code> file name.</p>
|
||
</section>
|
||
<section id="windows">
|
||
<h2><a class="toc-backref" href="#windows" role="doc-backlink">Windows</a></h2>
|
||
<p>This PEP only addresses build issues on POSIX systems that use the
|
||
<code class="docutils literal notranslate"><span class="pre">configure</span></code> script. While Windows or other platform support is not
|
||
explicitly disallowed under this PEP, platform expertise is needed in
|
||
order to evaluate, describe, and implement support on such platforms.
|
||
It is not currently clear that the facilities in this PEP are even
|
||
useful for Windows.</p>
|
||
</section>
|
||
<section id="pep-384">
|
||
<h2><a class="toc-backref" href="#pep-384" role="doc-backlink">PEP 384</a></h2>
|
||
<p><a class="pep reference internal" href="../pep-0384/" title="PEP 384 – Defining a Stable ABI">PEP 384</a> defines a stable ABI for extension modules. In theory,
|
||
universal adoption of <a class="pep reference internal" href="../pep-0384/" title="PEP 384 – Defining a Stable ABI">PEP 384</a> would eliminate the need for this PEP
|
||
because all extension modules could be compatible with any Python
|
||
version. In practice of course, it will be impossible to achieve
|
||
universal adoption, and as described above, different build-time flags
|
||
still affect the ABI. Thus even with a stable ABI, this PEP may still
|
||
be necessary. While a complete specification is reserved for <a class="pep reference internal" href="../pep-0384/" title="PEP 384 – Defining a Stable ABI">PEP 384</a>,
|
||
here is a discussion of the relevant issues.</p>
|
||
<p><a class="pep reference internal" href="../pep-0384/" title="PEP 384 – Defining a Stable ABI">PEP 384</a> describes a change to <code class="docutils literal notranslate"><span class="pre">PyModule_Create()</span></code> where <code class="docutils literal notranslate"><span class="pre">3</span></code> is
|
||
passed as the API version if the extension was compiled with
|
||
<code class="docutils literal notranslate"><span class="pre">Py_LIMITED_API</span></code>. This should be formalized into an official macro
|
||
called <code class="docutils literal notranslate"><span class="pre">PYTHON_ABI_VERSION</span></code> to mirror <code class="docutils literal notranslate"><span class="pre">PYTHON_API_VERSION</span></code>. If
|
||
and when the ABI changes in an incompatible way, this version number
|
||
would be bumped. To facilitate sharing, Python would be extended to
|
||
search for extension modules with the <code class="docutils literal notranslate"><span class="pre">PYTHON_ABI_VERSION</span></code> number in
|
||
its name. The prefix <code class="docutils literal notranslate"><span class="pre">abi</span></code> is reserved for Python’s use.</p>
|
||
<p>Thus, an initial implementation of <a class="pep reference internal" href="../pep-0384/" title="PEP 384 – Defining a Stable ABI">PEP 384</a>, when Python is configured
|
||
with the default set of flags, would search for the following file
|
||
names when extension module <code class="docutils literal notranslate"><span class="pre">foo</span></code> is imported (in this order):</p>
|
||
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">foo</span><span class="o">.</span><span class="n">cpython</span><span class="o">-</span><span class="n">XYm</span><span class="o">.</span><span class="n">so</span>
|
||
<span class="n">foo</span><span class="o">.</span><span class="n">abi3</span><span class="o">.</span><span class="n">so</span>
|
||
<span class="n">foo</span><span class="o">.</span><span class="n">so</span>
|
||
</pre></div>
|
||
</div>
|
||
<p>The distutils <a class="footnote-reference brackets" href="#id12" id="id4">[6]</a> <code class="docutils literal notranslate"><span class="pre">build_ext</span></code> command would also have to be
|
||
extended to compile to shared library files with the <code class="docutils literal notranslate"><span class="pre">abi3</span></code> tag,
|
||
when the module author indicates that their extension supports that
|
||
version of the ABI. This could be done in a backward compatible way
|
||
by adding a keyword argument to the <code class="docutils literal notranslate"><span class="pre">Extension</span></code> class, such as:</p>
|
||
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">Extension</span><span class="p">(</span><span class="s1">'foo'</span><span class="p">,</span> <span class="p">[</span><span class="s1">'foo.c'</span><span class="p">],</span> <span class="n">abi</span><span class="o">=</span><span class="mi">3</span><span class="p">)</span>
|
||
</pre></div>
|
||
</div>
|
||
<p>Martin v. Löwis describes his thoughts <a class="footnote-reference brackets" href="#id13" id="id5">[7]</a> about the applicability of this
|
||
PEP to <a class="pep reference internal" href="../pep-0384/" title="PEP 384 – Defining a Stable ABI">PEP 384</a>. In summary:</p>
|
||
<ul class="simple">
|
||
<li><code class="docutils literal notranslate"><span class="pre">--with-pydebug</span></code> would not be supported by the stable ABI because
|
||
this changes the layout of <code class="docutils literal notranslate"><span class="pre">PyObject</span></code>, which is an exposed
|
||
structure.</li>
|
||
<li><code class="docutils literal notranslate"><span class="pre">--with-pymalloc</span></code> has no bearing on the issue.</li>
|
||
<li><code class="docutils literal notranslate"><span class="pre">--with-wide-unicode</span></code> is trickier, though Martin’s inclination is
|
||
to force the stable ABI to use a <code class="docutils literal notranslate"><span class="pre">Py_UNICODE</span></code> that matches the
|
||
platform’s <code class="docutils literal notranslate"><span class="pre">wchar_t</span></code>.</li>
|
||
</ul>
|
||
</section>
|
||
<section id="alternatives">
|
||
<h2><a class="toc-backref" href="#alternatives" role="doc-backlink">Alternatives</a></h2>
|
||
<p>In the initial python-dev thread <a class="footnote-reference brackets" href="#id14" id="id6">[8]</a> where this idea was first
|
||
introduced, several alternatives were suggested. For completeness
|
||
they are listed here, along with the reasons for not adopting them.</p>
|
||
<section id="independent-directories-or-symlinks">
|
||
<h3><a class="toc-backref" href="#independent-directories-or-symlinks" role="doc-backlink">Independent directories or symlinks</a></h3>
|
||
<p>Debian and Ubuntu could simply add a version-specific directory to
|
||
<code class="docutils literal notranslate"><span class="pre">sys.path</span></code> that would contain just the extension modules for that
|
||
version of Python. Or the symlink trick eliminated in <a class="pep reference internal" href="../pep-3147/" title="PEP 3147 – PYC Repository Directories">PEP 3147</a> could
|
||
be retained for just shared libraries. This approach is rejected
|
||
because it propagates the essential complexity that <a class="pep reference internal" href="../pep-3147/" title="PEP 3147 – PYC Repository Directories">PEP 3147</a> tries to
|
||
avoid, and adds potentially several additional directories to search
|
||
for all modules, even when the number of extension modules is much
|
||
fewer than the total number of Python packages. For example, builds
|
||
were made available both with and without wide unicode, with and
|
||
without pydebug, and with and without pymalloc, the total number of
|
||
directories search increases substantially.</p>
|
||
</section>
|
||
<section id="don-t-share-packages-with-extension-modules">
|
||
<h3><a class="toc-backref" href="#don-t-share-packages-with-extension-modules" role="doc-backlink">Don’t share packages with extension modules</a></h3>
|
||
<p>It has been suggested that Python packages with extension modules not
|
||
be shared among all supported Python versions on a distribution. Even
|
||
with adoption of <a class="pep reference internal" href="../pep-3149/" title="PEP 3149 – ABI version tagged .so files">PEP 3149</a>, extension modules will have to be compiled
|
||
for every supported Python version, so perhaps sharing of such
|
||
packages isn’t useful anyway. Not sharing packages with extensions
|
||
though is infeasible for several reasons.</p>
|
||
<p>If a pure-Python package is shared in one version, should it suddenly
|
||
be not-shared if the next release adds an extension module for speed?
|
||
Also, even though all extension shared libraries will be compiled and
|
||
distributed once for every supported Python, there’s a big difference
|
||
between duplicating the <code class="docutils literal notranslate"><span class="pre">.so</span></code> files and duplicating all <code class="docutils literal notranslate"><span class="pre">.py</span></code> files.
|
||
The extra size increases the download time for such packages, and more
|
||
immediately, increases the space pressures on already constrained
|
||
distribution CD-ROMs.</p>
|
||
</section>
|
||
</section>
|
||
<section id="reference-implementation">
|
||
<h2><a class="toc-backref" href="#reference-implementation" role="doc-backlink">Reference implementation</a></h2>
|
||
<p>Work on this code is tracked in a Bazaar branch on Launchpad <a class="footnote-reference brackets" href="#id15" id="id7">[9]</a>
|
||
until it’s ready for merge into Python 3.2. The work-in-progress diff
|
||
can also be viewed <a class="footnote-reference brackets" href="#id16" id="id8">[10]</a> and is updated automatically as new changes
|
||
are uploaded.</p>
|
||
</section>
|
||
<section id="references">
|
||
<h2><a class="toc-backref" href="#references" role="doc-backlink">References</a></h2>
|
||
<aside class="footnote-list brackets">
|
||
<aside class="footnote brackets" id="id9" role="doc-footnote">
|
||
<dt class="label" id="id9">[<a href="#id1">3</a>]</dt>
|
||
<dd>Ubuntu: <<a class="reference external" href="http://www.ubuntu.com">http://www.ubuntu.com</a>></aside>
|
||
<aside class="footnote brackets" id="id10" role="doc-footnote">
|
||
<dt class="label" id="id10">[<a href="#id2">4</a>]</dt>
|
||
<dd>Debian: <<a class="reference external" href="http://www.debian.org">http://www.debian.org</a>></aside>
|
||
<aside class="footnote brackets" id="id11" role="doc-footnote">
|
||
<dt class="label" id="id11">[<a href="#id3">5</a>]</dt>
|
||
<dd><a class="reference external" href="http://codespeak.net/pypy/dist/pypy/doc/">http://codespeak.net/pypy/dist/pypy/doc/</a></aside>
|
||
<aside class="footnote brackets" id="id12" role="doc-footnote">
|
||
<dt class="label" id="id12">[<a href="#id4">6</a>]</dt>
|
||
<dd><a class="reference external" href="http://docs.python.org/py3k/distutils/index.html">http://docs.python.org/py3k/distutils/index.html</a></aside>
|
||
<aside class="footnote brackets" id="id13" role="doc-footnote">
|
||
<dt class="label" id="id13">[<a href="#id5">7</a>]</dt>
|
||
<dd><a class="reference external" href="https://mail.python.org/pipermail/python-dev/2010-August/103330.html">https://mail.python.org/pipermail/python-dev/2010-August/103330.html</a></aside>
|
||
<aside class="footnote brackets" id="id14" role="doc-footnote">
|
||
<dt class="label" id="id14">[<a href="#id6">8</a>]</dt>
|
||
<dd><a class="reference external" href="https://mail.python.org/pipermail/python-dev/2010-June/100998.html">https://mail.python.org/pipermail/python-dev/2010-June/100998.html</a></aside>
|
||
<aside class="footnote brackets" id="id15" role="doc-footnote">
|
||
<dt class="label" id="id15">[<a href="#id7">9</a>]</dt>
|
||
<dd><a class="reference external" href="https://code.edge.launchpad.net/~barry/python/sovers">https://code.edge.launchpad.net/~barry/python/sovers</a></aside>
|
||
<aside class="footnote brackets" id="id16" role="doc-footnote">
|
||
<dt class="label" id="id16">[<a href="#id8">10</a>]</dt>
|
||
<dd><a class="reference external" href="https://code.edge.launchpad.net/~barry/python/sovers/+merge/29411">https://code.edge.launchpad.net/~barry/python/sovers/+merge/29411</a></aside>
|
||
</aside>
|
||
</section>
|
||
<section id="copyright">
|
||
<h2><a class="toc-backref" href="#copyright" role="doc-backlink">Copyright</a></h2>
|
||
<p>This document has been placed in the public domain.</p>
|
||
</section>
|
||
</section>
|
||
<hr class="docutils" />
|
||
<p>Source: <a class="reference external" href="https://github.com/python/peps/blob/main/peps/pep-3149.rst">https://github.com/python/peps/blob/main/peps/pep-3149.rst</a></p>
|
||
<p>Last modified: <a class="reference external" href="https://github.com/python/peps/commits/main/peps/pep-3149.rst">2023-09-09 17:39:29 GMT</a></p>
|
||
|
||
</article>
|
||
<nav id="pep-sidebar">
|
||
<h2>Contents</h2>
|
||
<ul>
|
||
<li><a class="reference internal" href="#abstract">Abstract</a></li>
|
||
<li><a class="reference internal" href="#background">Background</a></li>
|
||
<li><a class="reference internal" href="#rationale">Rationale</a></li>
|
||
<li><a class="reference internal" href="#proposal">Proposal</a></li>
|
||
<li><a class="reference internal" href="#proven-approach">Proven approach</a></li>
|
||
<li><a class="reference internal" href="#windows">Windows</a></li>
|
||
<li><a class="reference internal" href="#pep-384">PEP 384</a></li>
|
||
<li><a class="reference internal" href="#alternatives">Alternatives</a><ul>
|
||
<li><a class="reference internal" href="#independent-directories-or-symlinks">Independent directories or symlinks</a></li>
|
||
<li><a class="reference internal" href="#don-t-share-packages-with-extension-modules">Don’t share packages with extension modules</a></li>
|
||
</ul>
|
||
</li>
|
||
<li><a class="reference internal" href="#reference-implementation">Reference implementation</a></li>
|
||
<li><a class="reference internal" href="#references">References</a></li>
|
||
<li><a class="reference internal" href="#copyright">Copyright</a></li>
|
||
</ul>
|
||
|
||
<br>
|
||
<a id="source" href="https://github.com/python/peps/blob/main/peps/pep-3149.rst">Page Source (GitHub)</a>
|
||
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|
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