Remove outdated Python pre-3.9 code

These are manual fixes of src/cffi/

Co-Authored-By: mattip <matti.picus@gmail.com>

Author: DimitriPapadopoulos

src/cffi/api.py

@@ -3,12 +3,6 @@
 from .error import CDefError
 from . import model
 
-try:
-    basestring
-except NameError:
-    # Python 3.x
-    basestring = str
-
 _unspecified = object()
 
 
@@ -36,8 +30,7 @@ def __init__(self, backend=None):
         select a non-default backend, mostly for tests.
         """
         if backend is None:
-            # You need PyPy (>= 2.0 beta), or a CPython (>= 2.6) with
-            # _cffi_backend.so compiled.
+            # You need PyPy or a CPython with _cffi_backend.so compiled.
             import _cffi_backend as backend
             from . import __version__
             if backend.__version__ != __version__:
@@ -108,7 +101,7 @@ def embedding_api(self, csource, packed=False, pack=None):
 
     def _cdef(self, csource, override=False, **options):
         if not isinstance(csource, str):    # unicode, on Python 2
-            if not isinstance(csource, basestring):
+            if not isinstance(csource, str):
                 raise TypeError("cdef() argument must be a string")
             csource = csource.encode('ascii')
         with self._lock:
@@ -131,7 +124,7 @@ def dlopen(self, name, flags=0):
         linked to a particular library, just like C headers; in the
         library we only look for the actual (untyped) symbols.
         """
-        if not (isinstance(name, basestring) or
+        if not (isinstance(name, str) or
                 name is None or
                 isinstance(name, self.CData)):
             raise TypeError("dlopen(name): name must be a file name, None, "
@@ -186,7 +179,7 @@ def typeof(self, cdecl):
         corresponding <ctype> object.
         It can also be used on 'cdata' instance to get its C type.
         """
-        if isinstance(cdecl, basestring):
+        if isinstance(cdecl, str):
             return self._typeof(cdecl)
         if isinstance(cdecl, self.CData):
             return self._backend.typeof(cdecl)
@@ -204,7 +197,7 @@ def sizeof(self, cdecl):
         """Return the size in bytes of the argument.  It can be a
         string naming a C type, or a 'cdata' instance.
         """
-        if isinstance(cdecl, basestring):
+        if isinstance(cdecl, str):
             BType = self._typeof(cdecl)
             return self._backend.sizeof(BType)
         else:
@@ -214,7 +207,7 @@ def alignof(self, cdecl):
         """Return the natural alignment size in bytes of the C type
         given as a string.
         """
-        if isinstance(cdecl, basestring):
+        if isinstance(cdecl, str):
             cdecl = self._typeof(cdecl)
         return self._backend.alignof(cdecl)
 
@@ -225,7 +218,7 @@ def offsetof(self, cdecl, *fields_or_indexes):
         You can also give numeric values which correspond to array
         items, in case of an array type.
         """
-        if isinstance(cdecl, basestring):
+        if isinstance(cdecl, str):
             cdecl = self._typeof(cdecl)
         return self._typeoffsetof(cdecl, *fields_or_indexes)[1]
 
@@ -252,7 +245,7 @@ def new(self, cdecl, init=None):
         about that when copying the pointer to the memory somewhere
         else, e.g. into another structure.
         """
-        if isinstance(cdecl, basestring):
+        if isinstance(cdecl, str):
             cdecl = self._typeof(cdecl)
         return self._backend.newp(cdecl, init)
 
@@ -275,7 +268,7 @@ def new_allocator(self, alloc=None, free=None,
         allocator = compiled_ffi.new_allocator(alloc, free,
                                                should_clear_after_alloc)
         def allocate(cdecl, init=None):
-            if isinstance(cdecl, basestring):
+            if isinstance(cdecl, str):
                 cdecl = self._typeof(cdecl)
             return allocator(cdecl, init)
         return allocate
@@ -285,7 +278,7 @@ def cast(self, cdecl, source):
         type initialized with the given 'source'.  The source is
         casted between integers or pointers of any type.
         """
-        if isinstance(cdecl, basestring):
+        if isinstance(cdecl, str):
             cdecl = self._typeof(cdecl)
         return self._backend.cast(cdecl, source)
 
@@ -350,7 +343,7 @@ def from_buffer(self, cdecl, python_buffer=_unspecified,
         """
         if python_buffer is _unspecified:
             cdecl, python_buffer = self.BCharA, cdecl
-        elif isinstance(cdecl, basestring):
+        elif isinstance(cdecl, str):
             cdecl = self._typeof(cdecl)
         return self._backend.from_buffer(cdecl, python_buffer,
                                          require_writable)
@@ -385,7 +378,7 @@ def callback_decorator_wrap(python_callable):
                                 "is not callable")
             return self._backend.callback(cdecl, python_callable,
                                           error, onerror)
-        if isinstance(cdecl, basestring):
+        if isinstance(cdecl, str):
             cdecl = self._typeof(cdecl, consider_function_as_funcptr=True)
         if python_callable is None:
             return callback_decorator_wrap                # decorator mode
@@ -398,7 +391,7 @@ def getctype(self, cdecl, replace_with=''):
         extra text to append (or insert for more complicated C types), like
         a variable name, or '*' to get actually the C type 'pointer-to-cdecl'.
         """
-        if isinstance(cdecl, basestring):
+        if isinstance(cdecl, str):
             cdecl = self._typeof(cdecl)
         replace_with = replace_with.strip()
         if (replace_with.startswith('*')
@@ -605,10 +598,7 @@ def ensure(key, value):
                 if hasattr(sys, 'gettotalrefcount'):
                     template += '_d'
             else:
-                try:
-                    import sysconfig
-                except ImportError:    # 2.6
-                    from cffi._shimmed_dist_utils import sysconfig
+                import sysconfig
                 template = "python%d.%d"
                 if sysconfig.get_config_var('DEBUG_EXT'):
                     template += sysconfig.get_config_var('DEBUG_EXT')
@@ -625,7 +615,7 @@ def set_source(self, module_name, source, source_extension='.c', **kwds):
         if hasattr(self, '_assigned_source'):
             raise ValueError("set_source() cannot be called several times "
                              "per ffi object")
-        if not isinstance(module_name, basestring):
+        if not isinstance(module_name, str):
             raise TypeError("'module_name' must be a string")
         if os.sep in module_name or (os.altsep and os.altsep in module_name):
             raise ValueError("'module_name' must not contain '/': use a dotted "
@@ -791,7 +781,7 @@ def list_types(self):
 
 def _load_backend_lib(backend, name, flags):
     import os
-    if not isinstance(name, basestring):
+    if not isinstance(name, str):
         if sys.platform != "win32" or name is not None:
             return backend.load_library(name, flags)
         name = "c"    # Windows: load_library(None) fails, but this works
@@ -805,8 +795,8 @@ def _load_backend_lib(backend, name, flags):
     import ctypes.util
     path = ctypes.util.find_library(name)
     if path is None:
-        if name == "c" and sys.platform == "win32" and sys.version_info >= (3,):
-            raise OSError("dlopen(None) cannot work on Windows for Python 3 "
+        if name == "c" and sys.platform == "win32":
+            raise OSError("dlopen(None) cannot work on Windows "
                           "(see http://bugs.python.org/issue23606)")
         msg = ("ctypes.util.find_library() did not manage "
                f"to locate a library called {name!r}")
@@ -927,7 +917,7 @@ def __cffi_close__(self):
             backendlib.close_lib()
             self.__dict__.clear()
     #
-    if isinstance(libname, basestring):
+    if isinstance(libname, str):
         try:
             if not isinstance(libname, str):    # unicode, on Python 2
                 libname = libname.encode('utf-8')

src/cffi/backend_ctypes.py

@@ -1,11 +1,6 @@
 import ctypes, ctypes.util, operator, sys
 from . import model
 
-unicode = str
-long = int
-xrange = range
-bytechr = lambda num: bytes([num])
-
 class CTypesType(type):
     pass
 
@@ -154,7 +149,7 @@ def _newp(cls, init):
         return cls(init)
 
     def __iter__(self):
-        for i in xrange(len(self)):
+        for i in range(len(self)):
             yield self[i]
 
     def _get_own_repr(self):
@@ -176,7 +171,7 @@ def _cast_from(cls, source):
             address = 0
         elif isinstance(source, CTypesData):
             address = source._cast_to_integer()
-        elif isinstance(source, (int, long)):
+        elif isinstance(source, int):
             address = source
         else:
             raise TypeError(f"bad type for cast to {cls!r}: {type(source).__name__!r}")
@@ -348,7 +343,7 @@ def new_primitive_type(self, name):
             is_signed = (ctype(-1).value == -1)
         #
         def _cast_source_to_int(source):
-            if isinstance(source, (int, long, float)):
+            if isinstance(source, (int, float)):
                 source = int(source)
             elif isinstance(source, CTypesData):
                 source = source._cast_to_integer()
@@ -388,7 +383,7 @@ def __int__(self):
             if kind == 'bool':
                 @classmethod
                 def _cast_from(cls, source):
-                    if not isinstance(source, (int, long, float)):
+                    if not isinstance(source, (int, float)):
                         source = _cast_source_to_int(source)
                     return cls(bool(source))
                 def __int__(self):
@@ -398,7 +393,7 @@ def __int__(self):
                 @classmethod
                 def _cast_from(cls, source):
                     source = _cast_source_to_int(source)
-                    source = bytechr(source & 0xFF)
+                    source = bytes([source & 0xFF])
                     return cls(source)
                 def __int__(self):
                     return ord(self._value)
@@ -427,7 +422,7 @@ def __float__(self):
             if kind in {'int', 'byte', 'bool'}:
                 @staticmethod
                 def _to_ctypes(x):
-                    if not isinstance(x, (int, long)):
+                    if not isinstance(x, int):
                         if isinstance(x, CTypesData):
                             x = int(x)
                         else:
@@ -457,7 +452,7 @@ def __nonzero__(self):
             if kind == 'float':
                 @staticmethod
                 def _to_ctypes(x):
-                    if not isinstance(x, (int, long, float, CTypesData)):
+                    if not isinstance(x, (int, float, CTypesData)):
                         raise TypeError(f"float expected, got {type(x).__name__}")
                     return ctype(x).value
 
@@ -520,14 +515,14 @@ def __init__(self, init):
                 self._own = True
 
             def __add__(self, other):
-                if isinstance(other, (int, long)):
+                if isinstance(other, int):
                     return self._new_pointer_at(self._address +
                                                 other * self._bitem_size)
                 else:
                     return NotImplemented
 
             def __sub__(self, other):
-                if isinstance(other, (int, long)):
+                if isinstance(other, int):
                     return self._new_pointer_at(self._address -
                                                 other * self._bitem_size)
                 elif type(self) is type(other):
@@ -602,7 +597,7 @@ class CTypesArray(CTypesGenericArray):
 
             def __init__(self, init):
                 if length is None:
-                    if isinstance(init, (int, long)):
+                    if isinstance(init, int):
                         len1 = init
                         init = None
                     elif kind == 'char' and isinstance(init, bytes):
@@ -681,7 +676,7 @@ def _arg_to_ctypes(value):
                 return CTypesPtr._arg_to_ctypes(value)
 
             def __add__(self, other):
-                if isinstance(other, (int, long)):
+                if isinstance(other, int):
                     return CTypesPtr._new_pointer_at(
                         ctypes.addressof(self._blob) +
                         other * ctypes.sizeof(BItem._ctype))
@@ -760,7 +755,7 @@ def initialize(blob, init):
                                     "only one supported (use a dict if needed)"
                                      % (len(init),))
             if not isinstance(init, dict):
-                if isinstance(init, (bytes, unicode)):
+                if isinstance(init, (bytes, str)):
                     raise TypeError("union initializer: got a str")
                 init = tuple(init)
                 if len(init) > len(fnames):
@@ -1044,7 +1039,7 @@ def typeoffsetof(self, BType, fieldname, num=0):
             if BField is Ellipsis:
                 raise TypeError("not supported for bitfields")
             return (BField, BType._offsetof(fieldname))
-        elif isinstance(fieldname, (int, long)):
+        elif isinstance(fieldname, int):
             if issubclass(BType, CTypesGenericArray):
                 BType = BType._CTPtr
             if not issubclass(BType, CTypesGenericPtr):

src/cffi/ffiplatform.py

@@ -1,4 +1,4 @@
-import sys, os
+import sys, os, io
 from .error import VerificationError
 
 
@@ -81,13 +81,6 @@ def maybe_relative_path(path):
 
 # ____________________________________________________________
 
-try:
-    int_or_long = (int, long)
-    import cStringIO
-except NameError:
-    int_or_long = int      # Python 3
-    import io as cStringIO
-
 def _flatten(x, f):
     if isinstance(x, str):
         f.write('%ds%s' % (len(x), x))
@@ -101,13 +94,13 @@ def _flatten(x, f):
         f.write('%dl' % len(x))
         for value in x:
             _flatten(value, f)
-    elif isinstance(x, int_or_long):
+    elif isinstance(x, int):
         f.write('%di' % (x,))
     else:
         raise TypeError(
             f"the keywords to verify() contains unsupported object {x!r}")
 
 def flatten(x):
-    f = cStringIO.StringIO()
+    f = io.StringIO()
     _flatten(x, f)
     return f.getvalue()

src/cffi/lock.py

@@ -1,9 +1,6 @@
 import sys
 
-try:
-    from _thread import allocate_lock
-except ImportError:
-    from _dummy_thread import allocate_lock
+from _thread import allocate_lock
 
 
 ##import sys

src/cffi/pkgconfig.py

@@ -42,12 +42,11 @@ def call(libname, flag, encoding=sys.getfilesystemencoding()):
             pass
         raise PkgConfigError(berr.strip())
 
-    if sys.version_info >= (3,) and not isinstance(bout, str):   # Python 3.x
-        try:
-            bout = bout.decode(encoding)
-        except UnicodeDecodeError:
-            raise PkgConfigError(f"pkg-config {flag} {libname} returned bytes that cannot "
-                                 f"be decoded with encoding {encoding!r}:\n{bout!r}")
+    try:
+        bout = bout.decode(encoding)
+    except UnicodeDecodeError:
+        raise PkgConfigError(f"pkg-config {flag} {libname} returned bytes that cannot "
+                             f"be decoded with encoding {encoding!r}:\n{bout!r}")
 
     if os.altsep != '\\' and '\\' in bout:
         raise PkgConfigError(f"pkg-config {flag} {libname} returned an unsupported "