merge

6 files changed, 70 insertions, 8 deletions

diff --git a/docs/index.rst b/docs/index.rst
index 5b1b157..f1dbce6 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -111,9 +111,21 @@ used to specify the Python version tag to use more precisely::
                        equates to the tag "py2.py3".
     --python-tag XXX   Specifies the precise python version tag to use for
                        a pure-python wheel.
-
-Neither of these two flags have any effect when used on a project that includes
-C extension code.
+    --py-limited-api {cp32|cp33|cp34|...}
+                       Specifies Python Py_LIMITED_API compatibility with
+                       the version of CPython passed and later versions.
+                       The wheel will be tagged cpNN.abi3.{arch} on CPython 3.
+                       This flag does not affect Python 2 builds or alternate
+                       Python implementations.
+
+                       To conform to the limited API, all your C
+                       extensions must use only functions from the limited
+                       API, pass Extension(py_limited_api=True) and e.g.
+                       #define Py_LIMITED_API=0x03020000 depending on
+                       the exact minimun Python you wish to support.
+
+The --universal and --python-tag flags have no effect when used on a
+project that includes C extension code.
 
 The default for a pure Python project (if no explicit flags are given) is "pyN"
 where N is the major version of the Python interpreter used to build the wheel.
diff --git a/wheel/bdist_wheel.py b/wheel/bdist_wheel.py
index d716163..edbba05 100644
--- a/wheel/bdist_wheel.py
+++ b/wheel/bdist_wheel.py
@@ -12,6 +12,7 @@ import warnings
 import shutil
 import json
 import sys
+import re
 
 try:
     import sysconfig
@@ -40,6 +41,8 @@ from .metadata import pkginfo_to_dict
 from . import pep425tags, metadata
 from . import __version__ as wheel_version
 
+PY_LIMITED_API_PATTERN = r'cp3\d'
+
 def safer_name(name):
     return safe_name(name).replace('-', '_')
 
@@ -77,6 +80,9 @@ class bdist_wheel(Command):
                     ('python-tag=', None,
                      "Python implementation compatibility tag"
                      " (default: py%s)" % get_impl_ver()[0]),
+                    ('py-limited-api=', None,
+                     "Python tag (cp32|cp33|cpNN) for abi3 wheel tag"
+                     " (default: false)"),
                     ]
 
     boolean_options = ['keep-temp', 'skip-build', 'relative', 'universal']
@@ -98,6 +104,7 @@ class bdist_wheel(Command):
         self.group = None
         self.universal = False
         self.python_tag = 'py' + get_impl_ver()[0]
+        self.py_limited_api = False
         self.plat_name_supplied = False
 
     def finalize_options(self):
@@ -116,6 +123,9 @@ class bdist_wheel(Command):
         self.root_is_pure = not (self.distribution.has_ext_modules()
                                  or self.distribution.has_c_libraries())
 
+        if self.py_limited_api and not re.match(PY_LIMITED_API_PATTERN, self.py_limited_api):
+            raise ValueError("py-limited-api must match '%s'" % PY_LIMITED_API_PATTERN)
+
         # Support legacy [wheel] section for setting universal
         wheel = self.distribution.get_option_dict('wheel')
         if 'universal' in wheel:
@@ -153,13 +163,20 @@ class bdist_wheel(Command):
         else:
             impl_name = get_abbr_impl()
             impl_ver = get_impl_ver()
-            # PEP 3149
-            abi_tag = str(get_abi_tag()).lower()
-            tag = (impl_name + impl_ver, abi_tag, plat_name)
+            impl = impl_name + impl_ver
+            # We don't work on CPython 3.1, 3.0.
+            if self.py_limited_api and (impl_name + impl_ver).startswith('cp3'):
+                impl = self.py_limited_api
+                abi_tag = 'abi3'
+            else:
+                abi_tag = str(get_abi_tag()).lower()
+            tag = (impl, abi_tag, plat_name)
             supported_tags = pep425tags.get_supported(
                 supplied_platform=plat_name if self.plat_name_supplied else None)
             # XXX switch to this alternate implementation for non-pure:
-            assert tag == supported_tags[0], "%s != %s" % (tag, supported_tags[0])
+            if not self.py_limited_api:
+                assert tag == supported_tags[0], "%s != %s" % (tag, supported_tags[0])
+            assert tag in supported_tags, "would build wheel with unsupported tag %s" % tag
         return tag
 
     def get_archive_basename(self):
diff --git a/wheel/pep425tags.py b/wheel/pep425tags.py
index 5ac5d0d..49a1367 100644
--- a/wheel/pep425tags.py
+++ b/wheel/pep425tags.py
@@ -152,7 +152,16 @@ def get_supported(versions=None, supplied_platform=None):
     for abi in abis:
         for arch in platforms:
             supported.append(('%s%s' % (impl, versions[0]), abi, arch))
-            
+
+    # abi3 modules compatible with older version of Python
+    for version in versions[1:]:
+        # abi3 was introduced in Python 3.2
+        if version in ('31', '30'):
+            break
+        for abi in abi3s:   # empty set if not Python 3
+            for arch in platforms:
+                supported.append(("%s%s" % (impl, version), abi, arch))
+
     # No abi / arch, but requires our implementation:
     for i, version in enumerate(versions):
         supported.append(('%s%s' % (impl, version), 'none', 'any'))
diff --git a/wheel/test/extension.dist/extension.c b/wheel/test/extension.dist/extension.c
new file mode 100644
index 0000000..a37c3fa
--- /dev/null
+++ b/wheel/test/extension.dist/extension.c
@@ -0,0 +1,2 @@
+#define Py_LIMITED_API 0x03020000
+#include <Python.h>
diff --git a/wheel/test/extension.dist/setup.cfg b/wheel/test/extension.dist/setup.cfg
new file mode 100644
index 0000000..9f6ff39
--- /dev/null
+++ b/wheel/test/extension.dist/setup.cfg
@@ -0,0 +1,2 @@
+[bdist_wheel]
+py_limited_api=cp32
diff --git a/wheel/test/extension.dist/setup.py b/wheel/test/extension.dist/setup.py
new file mode 100644
index 0000000..7a66845
--- /dev/null
+++ b/wheel/test/extension.dist/setup.py
@@ -0,0 +1,20 @@
+from setuptools import setup, Extension
+
+try:
+    unicode
+    def u8(s):
+        return s.decode('unicode-escape').encode('utf-8')
+except NameError:
+    def u8(s):
+        return s.encode('utf-8')
+
+setup(name='extension.dist',
+      version='0.1',
+      description=u8('A testing distribution \N{SNOWMAN}'),
+      ext_modules=[
+          Extension(name='extension', 
+          sources=['extension.c'], 
+          py_limited_api=True)
+          ],
+      )
+