Add initial support for Python 3.14a7.

- Header files have moved around.
- Reference counting has changed. It appears to be python/cpython#130708 that's eliding some reference counting within functions and caused us to need to lower our expected reference count in a few places. NOTE: I'm not 100% sure this is the case; dis.dis is broken and won't show the function bodies so I can't confirm the new opcodes are being used.

Author: jamadden

.github/workflows/tests.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [3.9, "3.10", "3.11", "3.12", "3.13"]
+        python-version: [3.9, "3.10", "3.11", "3.12", "3.13", "3.14.0-alpha.7"]
         os: [ubuntu-latest]
         include:
           # Needs to be all supported Python versions, they upload the built
@@ -40,6 +40,8 @@ jobs:
             python-version: "3.12"
           - os: macos-latest
             python-version: "3.13"
+          - os: macos-latest
+            python-version: "3.14.0-alpha.7"
     steps:
     - uses: actions/checkout@v4
     - name: Set up Python

src/greenlet/TGreenlet.hpp

@@ -27,6 +27,11 @@ using greenlet::refs::BorrowedGreenlet;
 #  include "internal/pycore_frame.h"
 #endif
 
+#if GREENLET_PY314
+#  include "internal/pycore_interpframe_structs.h"
+#  include "internal/pycore_interpframe.h"
+#endif
+
 // XXX: TODO: Work to remove all virtual functions
 // for speed of calling and size of objects (no vtable).
 // One pattern is the Curiously Recurring Template

src/greenlet/greenlet_cpython_compat.hpp

@@ -61,6 +61,12 @@ Greenlet won't compile on anything older than Python 3.11 alpha 4 (see
 #    define GREENLET_PY313 0
 #endif
 
+#if PY_VERSION_HEX >= 0x30E0000
+#    define GREENLET_PY314 1
+#else
+#    define GREENLET_PY314 0
+#endif
+
 #ifndef Py_SET_REFCNT
 /* Py_REFCNT and Py_SIZE macros are converted to functions
 https://bugs.python.org/issue39573 */

src/greenlet/tests/__init__.py

@@ -25,6 +25,9 @@
 
 PY312 = sys.version_info[:2] >= (3, 12)
 PY313 = sys.version_info[:2] >= (3, 13)
+# XXX: First tested on 3.14a7. Revisit all uses of this on later versions to ensure they
+# are still valid.
+PY314 = sys.version_info[:2] >= (3, 14)
 
 WIN = sys.platform.startswith("win")
 RUNNING_ON_GITHUB_ACTIONS = os.environ.get('GITHUB_ACTIONS')

src/greenlet/tests/test_contextvars.py

@@ -11,7 +11,7 @@
 from greenlet import greenlet
 from greenlet import getcurrent
 from . import TestCase
-
+from . import PY314
 
 try:
     from contextvars import Context
@@ -208,8 +208,10 @@ def target():
         # Make sure there are no reference leaks
         gr = None
         gc.collect()
-        self.assertEqual(sys.getrefcount(old_context), 2)
-        self.assertEqual(sys.getrefcount(new_context), 2)
+        # Python 3.14 elides reference counting operations
+        # in some cases. See https://github.com/python/cpython/pull/130708
+        self.assertEqual(sys.getrefcount(old_context), 2 if not PY314 else 1)
+        self.assertEqual(sys.getrefcount(new_context), 2 if not PY314 else 1)
 
     def test_context_assignment_different_thread(self):
         import threading

src/greenlet/tests/test_greenlet.py

@@ -12,6 +12,7 @@
 from . import TestCase
 from . import RUNNING_ON_MANYLINUX
 from . import PY313
+from . import PY314
 from .leakcheck import fails_leakcheck
 
 
@@ -123,13 +124,15 @@ def g():
             g = RawGreenlet(f)
             g.switch()
             lst.append('c')
-
+        self.assertEqual(sys.getrefcount(g), 1)
         g = RawGreenlet(g)
-        self.assertEqual(sys.getrefcount(g), 2)
+        # Python 3.14 elides reference counting operations
+        # in some cases. See https://github.com/python/cpython/pull/130708
+        self.assertEqual(sys.getrefcount(g), 2 if not PY314 else 1)
         g.switch()
         self.assertEqual(lst, ['a', 'b', 'c'])
         # Just the one in this frame, plus the one on the stack we pass to the function
-        self.assertEqual(sys.getrefcount(g), 2)
+        self.assertEqual(sys.getrefcount(g), 2 if not PY314 else 1)
 
     def test_threads(self):
         success = []

src/greenlet/tests/test_leaks.py

@@ -14,6 +14,7 @@
 
 import greenlet
 from . import TestCase
+from . import PY314
 from .leakcheck import fails_leakcheck
 from .leakcheck import ignores_leakcheck
 from .leakcheck import RUNNING_ON_MANYLINUX
@@ -52,12 +53,15 @@ def test_arg_refs(self):
 
     def test_kwarg_refs(self):
         kwargs = {}
+        self.assertEqual(sys.getrefcount(kwargs), 1)
         # pylint:disable=unnecessary-lambda
         g = greenlet.greenlet(
-            lambda **kwargs: greenlet.getcurrent().parent.switch(**kwargs))
+            lambda **gkwargs: greenlet.getcurrent().parent.switch(**gkwargs))
         for _ in range(100):
             g.switch(**kwargs)
-        self.assertEqual(sys.getrefcount(kwargs), 2)
+        # Python 3.14 elides reference counting operations
+        # in some cases. See https://github.com/python/cpython/pull/130708
+        self.assertEqual(sys.getrefcount(kwargs), 2 if not PY314 else 1)
 
 
     @staticmethod