Update to Cython 0.29

And stop the warnings about missing language_level.

.gitignore

@@ -25,6 +25,11 @@ src/gevent/libev/_corecffi.c
 src/gevent/libev/_corecffi.o
 src/gevent/resolver/cares.c
 
+# Cython annotations
+src/gevent/*.html
+src/gevent/libev/*.html
+src/gevent/resolver/*.html
+
 Makefile.ext
 MANIFEST
 *_flymake.py

CHANGES.rst

@@ -10,9 +10,13 @@
 - Add support for application-wide callbacks when ``Greenlet`` objects
   are started. See :pr:`1289`, provided by Yury Selivanov.
 
-- It is now possible to consume ready objects using next(gevent.iwait(objs)).
+- It is now possible to consume ready objects using `next(gevent.iwait(objs))`.
   Previously such a construction would hang. See :pr:`1288`, provided by Josh
-  Snyder.
+  Snyder. This is not recommended, though, as unwaited objects will
+  have dangling links.
+
+- Build with Cython 0.29 in '3str' mode.
+
 
 1.3.7 (2018-10-12)
 ==================

_setuputils.py

@@ -154,26 +154,49 @@ def system(cmd, cwd=None, env=None, **kwargs):
 
 # Cython
 
+# Based on code from
+# http://cython.readthedocs.io/en/latest/src/reference/compilation.html#distributing-cython-modules
+def _dummy_cythonize(extensions, **_kwargs):
+    for extension in extensions:
+        sources = []
+        for sfile in extension.sources:
+            path, ext = os.path.splitext(sfile)
+            if ext in ('.pyx', '.py'):
+                ext = '.c'
+                sfile = path + ext
+            sources.append(sfile)
+        extension.sources[:] = sources
+    return extensions
 
 try:
     from Cython.Build import cythonize
 except ImportError:
-    # The .c files had better already exist. Based on code from
-    # http://cython.readthedocs.io/en/latest/src/reference/compilation.html#distributing-cython-modules
-    def cythonize(extensions, **_kwargs):
-        for extension in extensions:
-            sources = []
-            for sfile in extension.sources:
-                path, ext = os.path.splitext(sfile)
-                if ext in ('.pyx', '.py'):
-                    ext = '.c'
-                    sfile = path + ext
-                sources.append(sfile)
-            extension.sources[:] = sources
-        return extensions
+    # The .c files had better already exist.
+    cythonize = _dummy_cythonize
 
 def cythonize1(ext):
-    new_ext = cythonize([ext], include_path=['src/gevent', 'src/gevent/libev', 'src/gevent/resolver'])[0]
+    try:
+        new_ext = cythonize(
+            [ext],
+            include_path=['src/gevent', 'src/gevent/libev', 'src/gevent/resolver'],
+            annotate=True,
+            compiler_directives={
+                'language_level': '3str',
+                'always_allow_keywords': False,
+                'infer_types': True,
+                'nonecheck': False,
+            }
+        )[0]
+    except ValueError:
+        # 'invalid literal for int() with base 10: '3str'
+        # This is seen when an older version of Cython is installed.
+        # It's a bit of a chicken-and-egg, though, because installing
+        # from dev-requirements first scans this egg for its requirements
+        # before doing any updates.
+        import traceback
+        traceback.print_exc()
+        new_ext = _dummy_cythonize([ext])[0]
+
     for optional_attr in ('configure', 'optional'):
         if hasattr(ext, optional_attr):
             setattr(new_ext, optional_attr,

ci-requirements.txt

@@ -4,8 +4,9 @@ wheel
 # Python 3.7 requires at least Cython 0.27.3.
 # 0.28 is faster, and (important!) lets us specify the target module
 # name to be created so that we can have both foo.py and _foo.so
-# at the same time.
-Cython >= 0.28.5
+# at the same time. 0.29 fixes some issues with Python 3.7,
+# and adds the 3str mode for transition to Python 3.
+Cython >= 0.29
 
 # Python 3.7 requires at least 0.4.14, which is ABI incompatible with earlier
 greenlet>=0.4.14 ; platform_python_implementation == "CPython"

src/gevent/_greenlet.pxd

@@ -173,5 +173,5 @@ cdef _killall(list greenlets, object exception)
 @cython.locals(done=list)
 cpdef joinall(greenlets, timeout=*, raise_error=*, count=*)
 
-cdef set _spawn_callbacks = None
-cdef _call_spawn_callbacks(gr)
+cdef set _spawn_callbacks
+cdef void _call_spawn_callbacks(Greenlet gr) except *