On Windows, we still can't use Py_LIMITED_API for bad reasons.

2 files changed, 19 insertions, 36 deletions

diff --git a/cffi/_cffi_include.h b/cffi/_cffi_include.h
index 6711428..37ea74f 100644
--- a/cffi/_cffi_include.h
+++ b/cffi/_cffi_include.h
@@ -8,43 +8,20 @@
    the same works for the other two macros.  Py_DEBUG implies them,
    but not the other way around.
 
-   The implementation is messy (issue #350): on Windows, with _MSC_VER,
-   we have to define Py_LIMITED_API even before including pyconfig.h.
-   In that case, we guess what pyconfig.h will do to the macros above,
-   and check our guess after the #include.
-
-   Note that on Windows, with CPython 3.x, you need virtualenv version
-   >= 16.0.0.  Older versions don't copy PYTHON3.DLL.  As a workaround
-   you can remove the definition of Py_LIMITED_API here.
-
-   See also 'py_limited_api' in cffi/setuptools_ext.py.
+   Issue #350 is still open: on Windows, the code here causes it to link
+   with PYTHON36.DLL (for example) instead of PYTHON3.DLL.  A fix was
+   attempted in 164e526a5515 and 14ce6985e1c3, but reverted: virtualenv
+   does not make PYTHON3.DLL available, and so the "correctly" compiled
+   version would not run inside a virtualenv.  We will re-apply the fix
+   after virtualenv has been fixed for some time.  For explanation, see
+   issue #355.  For a workaround if you want PYTHON3.DLL and don't worry
+   about virtualenv, see issue #350.  See also 'py_limited_api' in
+   setuptools_ext.py.
 */
 #if !defined(_CFFI_USE_EMBEDDING) && !defined(Py_LIMITED_API)
-#  ifdef _MSC_VER
-#    if !defined(_DEBUG) && !defined(Py_DEBUG) && !defined(Py_TRACE_REFS) && !defined(Py_REF_DEBUG)
-#      define Py_LIMITED_API
-#    endif
-#    include <pyconfig.h>
-     /* sanity-check: Py_LIMITED_API will cause crashes if any of these
-        are also defined.  Normally, the Python file PC/pyconfig.h does not
-        cause any of these to be defined, with the exception that _DEBUG
-        causes Py_DEBUG.  Double-check that. */
-#    ifdef Py_LIMITED_API
-#      if defined(Py_DEBUG)
-#        error "pyconfig.h unexpectedly defines Py_DEBUG, but Py_LIMITED_API is set"
-#      endif
-#      if defined(Py_TRACE_REFS)
-#        error "pyconfig.h unexpectedly defines Py_TRACE_REFS, but Py_LIMITED_API is set"
-#      endif
-#      if defined(Py_REF_DEBUG)
-#        error "pyconfig.h unexpectedly defines Py_REF_DEBUG, but Py_LIMITED_API is set"
-#      endif
-#    endif
-#  else
-#    include <pyconfig.h>
-#    if !defined(Py_DEBUG) && !defined(Py_TRACE_REFS) && !defined(Py_REF_DEBUG)
-#      define Py_LIMITED_API
-#    endif
+#  include <pyconfig.h>
+#  if !defined(Py_DEBUG) && !defined(Py_TRACE_REFS) && !defined(Py_REF_DEBUG)
+#    define Py_LIMITED_API
 #  endif
 #endif
 
diff --git a/cffi/setuptools_ext.py b/cffi/setuptools_ext.py
index a6eb8b8..df5a518 100644
--- a/cffi/setuptools_ext.py
+++ b/cffi/setuptools_ext.py
@@ -81,8 +81,14 @@ def _set_py_limited_api(Extension, kwds):
     it doesn't so far, creating troubles.  That's why we check
     for "not hasattr(sys, 'gettotalrefcount')" (the 2.7 compatible equivalent
     of 'd' not in sys.abiflags). (http://bugs.python.org/issue28401)
+
+    On Windows, with CPython <= 3.4, it's better not to use py_limited_api
+    because virtualenv *still* doesn't copy PYTHON3.DLL on these versions.
+    For now we'll skip py_limited_api on all Windows versions to avoid an
+    inconsistent mess.
     """
-    if 'py_limited_api' not in kwds and not hasattr(sys, 'gettotalrefcount'):
+    if ('py_limited_api' not in kwds and not hasattr(sys, 'gettotalrefcount')
+            and sys.platform != 'win32'):
         import setuptools
         try:
             setuptools_major_version = int(setuptools.__version__.partition('.')[0])