Remove support for Py2.6 and various quirks that special-cased it.gh2692_remove_py26_support

Closes #2692.

14 files changed, 35 insertions, 142 deletions

diff --git a/Cython/Build/Dependencies.py b/Cython/Build/Dependencies.py
index ae98fd74b..d0d83c41a 100644
--- a/Cython/Build/Dependencies.py
+++ b/Cython/Build/Dependencies.py
@@ -1056,31 +1056,25 @@ def cythonize(module_list, exclude=None, nthreads=0, aliases=None, quiet=False,
     if N <= 1:
         nthreads = 0
     if nthreads:
-        # Requires multiprocessing (or Python >= 2.6)
+        import multiprocessing
+        pool = multiprocessing.Pool(
+            nthreads, initializer=_init_multiprocessing_helper)
+        # This is a bit more involved than it should be, because KeyboardInterrupts
+        # break the multiprocessing workers when using a normal pool.map().
+        # See, for example:
+        # http://noswap.com/blog/python-multiprocessing-keyboardinterrupt
         try:
-            import multiprocessing
-            pool = multiprocessing.Pool(
-                nthreads, initializer=_init_multiprocessing_helper)
-        except (ImportError, OSError):
-            print("multiprocessing required for parallel cythonization")
-            nthreads = 0
-        else:
-            # This is a bit more involved than it should be, because KeyboardInterrupts
-            # break the multiprocessing workers when using a normal pool.map().
-            # See, for example:
-            # http://noswap.com/blog/python-multiprocessing-keyboardinterrupt
-            try:
-                result = pool.map_async(cythonize_one_helper, to_compile, chunksize=1)
-                pool.close()
-                while not result.ready():
-                    try:
-                        result.get(99999)  # seconds
-                    except multiprocessing.TimeoutError:
-                        pass
-            except KeyboardInterrupt:
-                pool.terminate()
-                raise
-            pool.join()
+            result = pool.map_async(cythonize_one_helper, to_compile, chunksize=1)
+            pool.close()
+            while not result.ready():
+                try:
+                    result.get(99999)  # seconds
+                except multiprocessing.TimeoutError:
+                    pass
+        except KeyboardInterrupt:
+            pool.terminate()
+            raise
+        pool.join()
     if not nthreads:
         for args in to_compile:
             cythonize_one(*args)
diff --git a/Cython/Compiler/Code.py b/Cython/Compiler/Code.py
index 232b0406e..e7ccdc5ae 100644
--- a/Cython/Compiler/Code.py
+++ b/Cython/Compiler/Code.py
@@ -43,8 +43,6 @@ try:
 except ImportError:
     from builtins import str as basestring
 
-KEYWORDS_MUST_BE_BYTES = sys.version_info < (2, 7)
-
 
 non_portable_builtins_map = {
     # builtins that have different names in different Python versions
@@ -259,15 +257,11 @@ class UtilityCodeBase(object):
             utility[1] = code
         else:
             all_tags = utility[2]
-            if KEYWORDS_MUST_BE_BYTES:
-                type = type.encode('ASCII')
             all_tags[type] = code
 
         if tags:
             all_tags = utility[2]
             for name, values in tags.items():
-                if KEYWORDS_MUST_BE_BYTES:
-                    name = name.encode('ASCII')
                 all_tags.setdefault(name, set()).update(values)
 
     @classmethod
diff --git a/Cython/Compiler/Errors.py b/Cython/Compiler/Errors.py
index 9761b52c3..4aa0e903c 100644
--- a/Cython/Compiler/Errors.py
+++ b/Cython/Compiler/Errors.py
@@ -60,8 +60,6 @@ class CompileError(PyrexError):
         self.message_only = message
         self.formatted_message = format_error(message, position)
         self.reported = False
-    # Deprecated and withdrawn in 2.6:
-    #   self.message = message
         Exception.__init__(self, self.formatted_message)
         # Python Exception subclass pickling is broken,
         # see http://bugs.python.org/issue1692335
@@ -74,8 +72,6 @@ class CompileWarning(PyrexWarning):
 
     def __init__(self, position = None, message = ""):
         self.position = position
-    # Deprecated and withdrawn in 2.6:
-    #   self.message = message
         Exception.__init__(self, format_position(position) + message)
 
 class InternalError(Exception):
diff --git a/Cython/Compiler/Main.py b/Cython/Compiler/Main.py
index 0f1ff4d33..9465edab3 100644
--- a/Cython/Compiler/Main.py
+++ b/Cython/Compiler/Main.py
@@ -9,8 +9,8 @@ import re
 import sys
 import io
 
-if sys.version_info[:2] < (2, 6) or (3, 0) <= sys.version_info[:2] < (3, 3):
-    sys.stderr.write("Sorry, Cython requires Python 2.6+ or 3.3+, found %d.%d\n" % tuple(sys.version_info[:2]))
+if sys.version_info[:2] < (2, 7) or (3, 0) <= sys.version_info[:2] < (3, 3):
+    sys.stderr.write("Sorry, Cython requires Python 2.7 or 3.3+, found %d.%d\n" % tuple(sys.version_info[:2]))
     sys.exit(1)
 
 try:
diff --git a/Cython/Compiler/ModuleNode.py b/Cython/Compiler/ModuleNode.py
index ce1a94289..c256ef883 100644
--- a/Cython/Compiler/ModuleNode.py
+++ b/Cython/Compiler/ModuleNode.py
@@ -635,9 +635,9 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         code.putln("#ifndef Py_PYTHON_H")
         code.putln("    #error Python headers needed to compile C extensions, "
                    "please install development version of Python.")
-        code.putln("#elif PY_VERSION_HEX < 0x02060000 || "
+        code.putln("#elif PY_VERSION_HEX < 0x02070000 || "
                    "(0x03000000 <= PY_VERSION_HEX && PY_VERSION_HEX < 0x03030000)")
-        code.putln("    #error Cython requires Python 2.6+ or Python 3.3+.")
+        code.putln("    #error Cython requires Python 2.7+ or Python 3.3+.")
         code.putln("#else")
         code.globalstate["end"].putln("#endif /* Py_PYTHON_H */")
 
diff --git a/Cython/Debugger/Tests/TestLibCython.py b/Cython/Debugger/Tests/TestLibCython.py
index b789b1062..2e2891039 100644
--- a/Cython/Debugger/Tests/TestLibCython.py
+++ b/Cython/Debugger/Tests/TestLibCython.py
@@ -56,13 +56,13 @@ def test_gdb():
                 stdout, _ = p.communicate()
                 try:
                     internal_python_version = list(map(int, stdout.decode('ascii', 'ignore').split()))
-                    if internal_python_version < [2, 6]:
+                    if internal_python_version < [2, 7]:
                         have_gdb = False
                 except ValueError:
                     have_gdb = False
 
     if not have_gdb:
-        warnings.warn('Skipping gdb tests, need gdb >= 7.2 with Python >= 2.6')
+        warnings.warn('Skipping gdb tests, need gdb >= 7.2 with Python >= 2.7')
 
     return have_gdb
 
diff --git a/Cython/Debugger/libpython.py b/Cython/Debugger/libpython.py
index fea626dd7..66d121040 100644
--- a/Cython/Debugger/libpython.py
+++ b/Cython/Debugger/libpython.py
@@ -48,7 +48,7 @@ The module also extends gdb with some python-specific commands.
 '''
 
 # NOTE: some gdbs are linked with Python 3, so this file should be dual-syntax
-# compatible (2.6+ and 3.0+).  See #19308.
+# compatible (2.7+ and 3.3+).  See #19308.
 
 from __future__ import print_function
 import gdb
@@ -1435,8 +1435,8 @@ The following code should ensure that the prettyprinter is registered
 if the code is autoloaded by gdb when visiting libpython.so, provided
 that this python file is installed to the same path as the library (or its
 .debug file) plus a "-gdb.py" suffix, e.g:
-  /usr/lib/libpython2.6.so.1.0-gdb.py
-  /usr/lib/debug/usr/lib/libpython2.6.so.1.0.debug-gdb.py
+  /usr/lib/libpython3.7.so.1.0-gdb.py
+  /usr/lib/debug/usr/lib/libpython3.7.so.1.0.debug-gdb.py
 """
 def register (obj):
     if obj is None:
diff --git a/Cython/Utility/Builtins.c b/Cython/Utility/Builtins.c
index 27a551213..df5c41fbc 100644
--- a/Cython/Utility/Builtins.c
+++ b/Cython/Utility/Builtins.c
@@ -418,9 +418,6 @@ static CYTHON_INLINE PyObject* __Pyx_PyDict_IterItems(PyObject* d) {
 
 //////////////////// py_dict_viewkeys.proto ////////////////////
 
-#if PY_VERSION_HEX < 0x02070000
-#error This module uses dict views, which require Python 2.7 or later
-#endif
 static CYTHON_INLINE PyObject* __Pyx_PyDict_ViewKeys(PyObject* d); /*proto*/
 
 //////////////////// py_dict_viewkeys ////////////////////
@@ -434,9 +431,6 @@ static CYTHON_INLINE PyObject* __Pyx_PyDict_ViewKeys(PyObject* d) {
 
 //////////////////// py_dict_viewvalues.proto ////////////////////
 
-#if PY_VERSION_HEX < 0x02070000
-#error This module uses dict views, which require Python 2.7 or later
-#endif
 static CYTHON_INLINE PyObject* __Pyx_PyDict_ViewValues(PyObject* d); /*proto*/
 
 //////////////////// py_dict_viewvalues ////////////////////
@@ -450,9 +444,6 @@ static CYTHON_INLINE PyObject* __Pyx_PyDict_ViewValues(PyObject* d) {
 
 //////////////////// py_dict_viewitems.proto ////////////////////
 
-#if PY_VERSION_HEX < 0x02070000
-#error This module uses dict views, which require Python 2.7 or later
-#endif
 static CYTHON_INLINE PyObject* __Pyx_PyDict_ViewItems(PyObject* d); /*proto*/
 
 //////////////////// py_dict_viewitems ////////////////////
diff --git a/Cython/Utility/Capsule.c b/Cython/Utility/Capsule.c
index cc4fe0d88..14c744cdf 100644
--- a/Cython/Utility/Capsule.c
+++ b/Cython/Utility/Capsule.c
@@ -6,15 +6,7 @@ static CYTHON_INLINE PyObject *__pyx_capsule_create(void *p, const char *sig);
 //////////////// Capsule ////////////////
 
 static CYTHON_INLINE PyObject *
-__pyx_capsule_create(void *p, CYTHON_UNUSED const char *sig)
+__pyx_capsule_create(void *p, const char *sig)
 {
-    PyObject *cobj;
-
-#if PY_VERSION_HEX >= 0x02070000
-    cobj = PyCapsule_New(p, sig, NULL);
-#else
-    cobj = PyCObject_FromVoidPtr(p, NULL);
-#endif
-
-    return cobj;
+    return PyCapsule_New(p, sig, NULL);
 }
diff --git a/Cython/Utility/CommonStructures.c b/Cython/Utility/CommonStructures.c
index c7945feb4..dfbacb2ab 100644
--- a/Cython/Utility/CommonStructures.c
+++ b/Cython/Utility/CommonStructures.c
@@ -56,7 +56,6 @@ static void* __Pyx_FetchCommonPointer(void* pointer, const char* name);
 
 
 static void* __Pyx_FetchCommonPointer(void* pointer, const char* name) {
-#if PY_VERSION_HEX >= 0x02070000
     PyObject* fake_module = NULL;
     PyObject* capsule = NULL;
     void* value = NULL;
@@ -80,7 +79,4 @@ bad:
     Py_XDECREF(capsule);
     Py_DECREF(fake_module);
     return value;
-#else
-    return pointer;
-#endif
 }
diff --git a/Cython/Utility/CpdefEnums.pyx b/Cython/Utility/CpdefEnums.pyx
index 148d776c2..546551f14 100644
--- a/Cython/Utility/CpdefEnums.pyx
+++ b/Cython/Utility/CpdefEnums.pyx
@@ -6,10 +6,7 @@ cdef extern from *:
     int PY_VERSION_HEX
 
 cdef object __Pyx_OrderedDict
-if PY_VERSION_HEX >= 0x02070000:
-    from collections import OrderedDict as __Pyx_OrderedDict
-else:
-    __Pyx_OrderedDict = dict
+from collections import OrderedDict as __Pyx_OrderedDict
 
 @cython.internal
 cdef class __Pyx_EnumMeta(type):
diff --git a/Cython/Utility/ImportExport.c b/Cython/Utility/ImportExport.c
index 670346723..bd18c7640 100644
--- a/Cython/Utility/ImportExport.c
+++ b/Cython/Utility/ImportExport.c
@@ -412,7 +412,6 @@ static int __Pyx_ImportFunction(PyObject *module, const char *funcname, void (**
                 PyModule_GetName(module), funcname);
         goto bad;
     }
-#if PY_VERSION_HEX >= 0x02070000
     if (!PyCapsule_IsValid(cobj, sig)) {
         PyErr_Format(PyExc_TypeError,
             "C function %.200s.%.200s has wrong signature (expected %.500s, got %.500s)",
@@ -420,21 +419,6 @@ static int __Pyx_ImportFunction(PyObject *module, const char *funcname, void (**
         goto bad;
     }
     tmp.p = PyCapsule_GetPointer(cobj, sig);
-#else
-    {const char *desc, *s1, *s2;
-    desc = (const char *)PyCObject_GetDesc(cobj);
-    if (!desc)
-        goto bad;
-    s1 = desc; s2 = sig;
-    while (*s1 != '\0' && *s1 == *s2) { s1++; s2++; }
-    if (*s1 != *s2) {
-        PyErr_Format(PyExc_TypeError,
-            "C function %.200s.%.200s has wrong signature (expected %.500s, got %.500s)",
-             PyModule_GetName(module), funcname, sig, desc);
-        goto bad;
-    }
-    tmp.p = PyCObject_AsVoidPtr(cobj);}
-#endif
     *f = tmp.fp;
     if (!(*f))
         goto bad;
@@ -472,11 +456,7 @@ static int __Pyx_ExportFunction(const char *name, void (*f)(void), const char *s
             goto bad;
     }
     tmp.fp = f;
-#if PY_VERSION_HEX >= 0x02070000
     cobj = PyCapsule_New(tmp.p, sig, 0);
-#else
-    cobj = PyCObject_FromVoidPtrAndDesc(tmp.p, (void *)sig, 0);
-#endif
     if (!cobj)
         goto bad;
     if (PyDict_SetItemString(d, name, cobj) < 0)
@@ -513,7 +493,6 @@ static int __Pyx_ImportVoidPtr(PyObject *module, const char *name, void **p, con
                 PyModule_GetName(module), name);
         goto bad;
     }
-#if PY_VERSION_HEX >= 0x02070000
     if (!PyCapsule_IsValid(cobj, sig)) {
         PyErr_Format(PyExc_TypeError,
             "C variable %.200s.%.200s has wrong signature (expected %.500s, got %.500s)",
@@ -521,21 +500,6 @@ static int __Pyx_ImportVoidPtr(PyObject *module, const char *name, void **p, con
         goto bad;
     }
     *p = PyCapsule_GetPointer(cobj, sig);
-#else
-    {const char *desc, *s1, *s2;
-    desc = (const char *)PyCObject_GetDesc(cobj);
-    if (!desc)
-        goto bad;
-    s1 = desc; s2 = sig;
-    while (*s1 != '\0' && *s1 == *s2) { s1++; s2++; }
-    if (*s1 != *s2) {
-        PyErr_Format(PyExc_TypeError,
-            "C variable %.200s.%.200s has wrong signature (expected %.500s, got %.500s)",
-             PyModule_GetName(module), name, sig, desc);
-        goto bad;
-    }
-    *p = PyCObject_AsVoidPtr(cobj);}
-#endif
     if (!(*p))
         goto bad;
     Py_DECREF(d);
@@ -567,11 +531,7 @@ static int __Pyx_ExportVoidPtr(PyObject *name, void *p, const char *sig) {
         if (__Pyx_PyObject_SetAttrStr($module_cname, PYIDENT("$api_name"), d) < 0)
             goto bad;
     }
-#if PY_VERSION_HEX >= 0x02070000
     cobj = PyCapsule_New(p, sig, 0);
-#else
-    cobj = PyCObject_FromVoidPtrAndDesc(p, (void *)sig, 0);
-#endif
     if (!cobj)
         goto bad;
     if (PyDict_SetItem(d, name, cobj) < 0)
@@ -593,11 +553,7 @@ static int __Pyx_SetVtable(PyObject *dict, void *vtable); /*proto*/
 /////////////// SetVTable ///////////////
 
 static int __Pyx_SetVtable(PyObject *dict, void *vtable) {
-#if PY_VERSION_HEX >= 0x02070000
     PyObject *ob = PyCapsule_New(vtable, 0, 0);
-#else
-    PyObject *ob = PyCObject_FromVoidPtr(vtable, 0);
-#endif
     if (!ob)
         goto bad;
     if (PyDict_SetItem(dict, PYIDENT("__pyx_vtable__"), ob) < 0)
@@ -621,11 +577,7 @@ static void* __Pyx_GetVtable(PyObject *dict) {
     PyObject *ob = PyObject_GetItem(dict, PYIDENT("__pyx_vtable__"));
     if (!ob)
         goto bad;
-#if PY_VERSION_HEX >= 0x02070000
     ptr = PyCapsule_GetPointer(ob, 0);
-#else
-    ptr = PyCObject_AsVoidPtr(ob);
-#endif
     if (!ptr && !PyErr_Occurred())
         PyErr_SetString(PyExc_RuntimeError, "invalid vtable found for imported type");
     Py_DECREF(ob);
diff --git a/Cython/Utility/ModuleSetupCode.c b/Cython/Utility/ModuleSetupCode.c
index 15422902e..6a9f75b20 100644
--- a/Cython/Utility/ModuleSetupCode.c
+++ b/Cython/Utility/ModuleSetupCode.c
@@ -29,9 +29,7 @@
 
 #ifndef HAVE_LONG_LONG
   // CPython has required PY_LONG_LONG support for years, even if HAVE_LONG_LONG is not defined for us
-  #if PY_VERSION_HEX >= 0x02070000
-    #define HAVE_LONG_LONG
-  #endif
+  #define HAVE_LONG_LONG
 #endif
 
 #ifndef PY_LONG_LONG
@@ -135,11 +133,7 @@
   #ifndef CYTHON_USE_TYPE_SLOTS
     #define CYTHON_USE_TYPE_SLOTS 1
   #endif
-  #if PY_VERSION_HEX < 0x02070000
-    // looks like calling _PyType_Lookup() isn't safe in Py<=2.6/3.1
-    #undef CYTHON_USE_PYTYPE_LOOKUP
-    #define CYTHON_USE_PYTYPE_LOOKUP 0
-  #elif !defined(CYTHON_USE_PYTYPE_LOOKUP)
+  #ifndef CYTHON_USE_PYTYPE_LOOKUP
     #define CYTHON_USE_PYTYPE_LOOKUP 1
   #endif
   #if PY_MAJOR_VERSION < 3
@@ -148,10 +142,7 @@
   #elif !defined(CYTHON_USE_ASYNC_SLOTS)
     #define CYTHON_USE_ASYNC_SLOTS 1
   #endif
-  #if PY_VERSION_HEX < 0x02070000
-    #undef CYTHON_USE_PYLONG_INTERNALS
-    #define CYTHON_USE_PYLONG_INTERNALS 0
-  #elif !defined(CYTHON_USE_PYLONG_INTERNALS)
+  #ifndef CYTHON_USE_PYLONG_INTERNALS
     #define CYTHON_USE_PYLONG_INTERNALS 1
   #endif
   #ifndef CYTHON_USE_PYLIST_INTERNALS
@@ -470,7 +461,7 @@ class __Pyx_FakeReference {
   #define __Pyx_PyFrame_SetLineNumber(frame, lineno)  (frame)->f_lineno = (lineno)
 #endif
 
-#if !CYTHON_FAST_THREAD_STATE || PY_VERSION_HEX < 0x02070000
+#if !CYTHON_FAST_THREAD_STATE
   #define __Pyx_PyThreadState_Current PyThreadState_GET()
 #elif PY_VERSION_HEX >= 0x03060000
   //#elif PY_VERSION_HEX >= 0x03050200
@@ -1396,10 +1387,6 @@ static void __Pyx_FastGilFuncInit(void);
 #define __Pyx_FastGIL_PyCapsule \
     __Pyx_FastGIL_ABI_module "." __Pyx_FastGIL_PyCapsuleName
 
-#if PY_VERSION_HEX < 0x02070000
-  #undef CYTHON_THREAD_LOCAL
-#endif
-
 #ifdef CYTHON_THREAD_LOCAL
 
 #include "pythread.h"
@@ -1492,11 +1479,7 @@ static void __Pyx_FastGilFuncInit0(void) {
 #endif
 
 static void __Pyx_FastGilFuncInit(void) {
-#if PY_VERSION_HEX >= 0x02070000
   struct __Pyx_FastGilVtab* shared = (struct __Pyx_FastGilVtab*)PyCapsule_Import(__Pyx_FastGIL_PyCapsule, 1);
-#else
-  struct __Pyx_FastGilVtab* shared = NULL;
-#endif
   if (shared) {
     __Pyx_FastGilFuncs = *shared;
   } else {
diff --git a/Cython/Utility/ObjectHandling.c b/Cython/Utility/ObjectHandling.c
index b147cb33e..75088f431 100644
--- a/Cython/Utility/ObjectHandling.c
+++ b/Cython/Utility/ObjectHandling.c
@@ -199,10 +199,8 @@ static CYTHON_INLINE PyObject *__Pyx_PyIter_Next2(PyObject* iterator, PyObject*
         next = iternext(iterator);
         if (likely(next))
             return next;
-        #if PY_VERSION_HEX >= 0x02070000
         if (unlikely(iternext == &_PyObject_NextNotImplemented))
             return NULL;
-        #endif
 #else
         // Since the slot was set, assume that PyIter_Next() will likely succeed, and properly fail otherwise.
         // Note: PyIter_Next() crashes in CPython if "tp_iternext" is NULL.
@@ -1303,7 +1301,7 @@ static PyObject *__Pyx_RaiseGenericGetAttributeError(PyTypeObject *tp, PyObject
 }
 
 static CYTHON_INLINE PyObject* __Pyx_PyObject_GenericGetAttrNoDict(PyObject* obj, PyObject* attr_name) {
-    // Copied and adapted from _PyObject_GenericGetAttrWithDict() in CPython 2.6/3.7.
+    // Copied and adapted from _PyObject_GenericGetAttrWithDict() in CPython 3.6/3.7.
     // To be used in the "tp_getattro" slot of extension types that have no instance dict and cannot be subclassed.
     PyObject *descr;
     PyTypeObject *tp = Py_TYPE(obj);