Merge branch 'master' into release

CHANGES.rst

@@ -34,6 +34,11 @@ Features added
 * ``cython.inline()`` supports a direct ``language_level`` keyword argument that
   was previously only available via a directive.
 
+* A new directive ``str_is_str=True`` was added that keeps unprefixed string
+  literals as type 'str' in both Py2 and Py3, and the builtin 'str' type unchanged
+  even when ``language_level=3``  is enabled.  This is meant to help user code to
+  migrate to Python 3 semantics without making support for Python 2.x difficult.
+
 * In CPython 3.6 and later, looking up globals in the module dict is almost
   as fast as looking up C globals.
   (Github issue #2313)
@@ -143,6 +148,10 @@ Bugs fixed
   the return value was non-null.
   Original patch by Matt Wozniski (Github Issue #2603)
 
+* The source file encoding detection could get confused if the
+  ``c_string_encoding`` directive appeared within the first two lines.
+  (Github issue #2632)
+
 Other changes
 -------------
 

Cython/Compiler/Main.py

@@ -94,9 +94,18 @@ class Context(object):
 
         if language_level is not None:
             self.set_language_level(language_level)
+        if self.compiler_directives.get('str_is_str') is not None:
+            self.set_str_is_str(self.compiler_directives['str_is_str'])
 
         self.gdb_debug_outputwriter = None
 
+    def set_str_is_str(self, str_is_str):
+        from .Future import unicode_literals
+        if str_is_str:
+            self.future_directives.discard(unicode_literals)
+        else:
+            self.future_directives.add(unicode_literals)
+
     def set_language_level(self, level):
         self.language_level = level
         if level >= 3:

Cython/Compiler/Options.py

@@ -198,6 +198,7 @@ _directive_defaults = {
     'iterable_coroutine': False,  # Make async coroutines backwards compatible with the old asyncio yield-from syntax.
     'c_string_type': 'bytes',
     'c_string_encoding': '',
+    'str_is_str': None,  # fall back to 'language_level == 2'
     'type_version_tag': True,  # enables Py_TPFLAGS_HAVE_VERSION_TAG on extension types
     'unraisable_tracebacks': True,
     'old_style_globals': False,
@@ -313,6 +314,7 @@ directive_types = {
     'freelist': int,
     'c_string_type': one_of('bytes', 'bytearray', 'str', 'unicode'),
     'c_string_encoding': normalise_encoding_name,
+    'str_is_str': bool,
 }
 
 for key, val in _directive_defaults.items():
@@ -347,6 +349,7 @@ directive_scopes = {  # defaults to available everywhere
     # Avoid scope-specific to/from_py_functions for c_string.
     'c_string_type': ('module',),
     'c_string_encoding': ('module',),
+    'str_is_str': ('module',),
     'type_version_tag': ('module', 'cclass'),
     'language_level': ('module',),
     # globals() could conceivably be controlled at a finer granularity,

Cython/Compiler/Parsing.py

@@ -3652,6 +3652,9 @@ def p_compiler_directive_comments(s):
             if 'language_level' in new_directives:
                 # Make sure we apply the language level already to the first token that follows the comments.
                 s.context.set_language_level(new_directives['language_level'])
+            if 'str_is_str' in new_directives:
+                # Make sure we apply 'str_is_str' directive already to the first token that follows the comments.
+                s.context.set_str_is_str(new_directives['str_is_str'])
 
             result.update(new_directives)
 

Cython/Compiler/Symtab.py

@@ -21,6 +21,7 @@ from .PyrexTypes import py_object_type, unspecified_type
 from .TypeSlots import (
     pyfunction_signature, pymethod_signature, richcmp_special_methods,
     get_special_method_signature, get_property_accessor_signature)
+from . import Future
 
 from . import Code
 
@@ -1002,10 +1003,12 @@ class BuiltinScope(Scope):
             cname, type = definition
             self.declare_var(name, type, None, cname)
 
-    def lookup(self, name, language_level=None):
-        # 'language_level' is passed by ModuleScope
-        if language_level == 3:
-            if name == 'str':
+    def lookup(self, name, language_level=None, str_is_str=None):
+        # 'language_level' and 'str_is_str' are passed by ModuleScope
+        if name == 'str':
+            if str_is_str is None:
+                str_is_str = language_level in (None, 2)
+            if not str_is_str:
                 name = 'unicode'
         return Scope.lookup(self, name)
 
@@ -1174,15 +1177,18 @@ class ModuleScope(Scope):
     def global_scope(self):
         return self
 
-    def lookup(self, name, language_level=None):
+    def lookup(self, name, language_level=None, str_is_str=None):
         entry = self.lookup_here(name)
         if entry is not None:
             return entry
 
         if language_level is None:
             language_level = self.context.language_level if self.context is not None else 3
+        if str_is_str is None:
+            str_is_str = language_level == 2 or (
+                self.context is not None and Future.unicode_literals not in self.context.future_directives)
 
-        return self.outer_scope.lookup(name, language_level=language_level)
+        return self.outer_scope.lookup(name, language_level=language_level, str_is_str=str_is_str)
 
     def declare_tuple_type(self, pos, components):
         components = tuple(components)

Cython/Utils.py

@@ -238,7 +238,7 @@ def decode_filename(filename):
 
 # support for source file encoding detection
 
-_match_file_encoding = re.compile(b"coding[:=]\s*([-\w.]+)").search
+_match_file_encoding = re.compile(br"(\w*coding)[:=]\s*([-\w.]+)").search
 
 
 def detect_opened_file_encoding(f):
@@ -254,8 +254,8 @@ def detect_opened_file_encoding(f):
         if not data:
             break
     m = _match_file_encoding(lines[0])
-    if m:
-        return m.group(1).decode('iso8859-1')
+    if m and m.group(1) != b'c_string_encoding':
+        return m.group(2).decode('iso8859-1')
     elif len(lines) > 1:
         m = _match_file_encoding(lines[1])
         if m:

docs/src/userguide/extension_types.rst

@@ -771,6 +771,81 @@ For public extension types, the object and type clauses are both required,
 because Cython must be able to generate code that is compatible with external C
 code.
 
+Attribute name matching and aliasing
+------------------------------------
+
+Sometimes the type's C struct as specified in ``object_struct_name`` may use
+different labels for the fields than those in the ``PyTypeObject``. This can
+easily happen in hand-coded C extensions where the ``PyTypeObject_Foo`` has a
+getter method, but the name does not match the name in the ``PyFooObject``. In
+NumPy, for instance, python-level ``dtype.itemsize`` is a getter for the C
+struct field ``elsize``. Cython supports aliasing field names so that one can
+write ``dtype.itemsize`` in Cython code which will be compiled into direct
+access of the C struct field, without going through a C-API equivalent of
+``dtype.__getattr__('itemsize')``.
+
+For example we may have an extension
+module ``foo_extension``::
+
+    cdef class Foo:
+        cdef public int field0, field1, field2;
+
+        def __init__(self, f0, f1, f2):
+            self.field0 = f0
+            self.field1 = f1
+            self.field2 = f2
+
+but a C struct in a file ``foo_nominal.h``::
+
+   typedef struct {
+        PyObject_HEAD
+        int f0;
+        int f1;
+        int f2;
+    } FooStructNominal;
+
+Note that the struct uses ``f0``, ``f1``, ``f2`` but they are ``field0``,
+``field1``, and ``field2`` in ``Foo``. We are given this situation, including
+a header file with that struct, and we wish to write a function to sum the
+values. If we write an extension module ``wrapper``::
+
+    cdef extern from "foo_nominal.h":
+
+        ctypedef class foo_extension.Foo [object FooStructNominal]:
+            cdef:
+                int field0
+                int field1
+                int feild2
+
+    def sum(Foo f):
+        return f.field0 + f.field1 + f.field2
+
+then ``wrapper.sum(f)`` (where ``f = foo_extension.Foo(1, 2, 3)``) will still
+use the C-API equivalent of::
+
+    return f.__getattr__('field0') +
+           f.__getattr__('field1') +
+           f.__getattr__('field1')
+
+instead of the desired C equivalent of ``return f->f0 + f->f1 + f->f2``. We can
+alias the fields by using::
+    cdef extern from "foo_nominal.h":
+
+        ctypedef class foo_extension.Foo [object FooStructNominal]:
+            cdef:
+                int field0 "f0"
+                int field1 "f1"
+                int field2 "f2"
+
+    def sum(Foo f) except -1:
+        return f.field0 + f.field1 + f.field2
+
+and now Cython will replace the slow ``__getattr__`` with direct C access to
+the FooStructNominal fields. This is useful when directly processing Python
+code. No changes to Python need be made to achieve significant speedups, even
+though the field names in Python and C are different. Of course, one should
+make sure the fields are equivalent.
+
 Implicit importing
 ------------------
 

docs/src/userguide/external_C_code.rst

@@ -219,6 +219,7 @@ same applies equally to union and enum declarations.
 |   } Foo;                |                                             |                                                                       |
 +-------------------------+---------------------------------------------+-----------------------------------------------------------------------+
 
+See also use of :ref:`external_extension_types`.
 Note that in all the cases below, you refer to the type in Cython code simply
 as :c:type:`Foo`, not ``struct Foo``.
 

runtests.py

@@ -1735,6 +1735,9 @@ class EndToEndTest(unittest.TestCase):
         old_path = os.environ.get('PYTHONPATH')
         env = dict(os.environ)
         env['PYTHONPATH'] = self.cython_syspath + os.pathsep + (old_path or '')
+        cmd = []
+        out = []
+        err = []
         for command_no, command in enumerate(filter(None, commands.splitlines()), 1):
             with self.stats.time('%s(%d)' % (self.name, command_no), 'c',
                                  'etoe-build' if ' setup.py ' in command else 'etoe-run'):
@@ -1743,11 +1746,15 @@ class EndToEndTest(unittest.TestCase):
                                      stdout=subprocess.PIPE,
                                      shell=True,
                                      env=env)
-                out, err = p.communicate()
+                _out, _err = p.communicate()
+                cmd.append(command)
+                out.append(_out)
+                err.append(_err)
             res = p.returncode
             if res != 0:
-                sys.stderr.write("%s\n%s\n%s\n" % (
-                    command, self._try_decode(out), self._try_decode(err)))
+                for c, o, e in zip(cmd, out, err):
+                    sys.stderr.write("%s\n%s\n%s\n\n" % (
+                        c, self._try_decode(o), self._try_decode(e)))
             self.assertEqual(0, res, "non-zero exit status")
         self.success = True
 

tests/run/cython3_no_unicode_literals.pyx

+# cython: language_level=3, binding=True, str_is_str=True
+# mode: run
+# tag: python3, str_is_str
+
+print(end='')  # test that language_level 3 applies immediately at the module start, for the first token.
+
+__doc__ = """
+>>> items = sorted(locals_function(1).items())
+>>> for item in items:
+...     print('%s = %r' % item)
+a = 1
+b = 2
+x = 'abc'
+"""
+
+def locals_function(a, b=2):
+    x = 'abc'
+    return locals()
+
+
+### true division
+
+def truediv(x):
+    """
+    >>> truediv(4)
+    2.0
+    >>> truediv(3)
+    1.5
+    """
+    return x / 2
+
+
+def truediv_int(int x):
+    """
+    >>> truediv_int(4)
+    2.0
+    >>> truediv_int(3)
+    1.5
+    """
+    return x / 2
+
+
+### Py3 feature tests
+
+def print_function(*args):
+    """
+    >>> print_function(1,2,3)
+    1 2 3
+    """
+    print(*args) # this isn't valid Py2 syntax
+
+
+str_string = "abcdefg"
+
+def no_unicode_literals():
+    """
+    >>> print( no_unicode_literals() )
+    True
+    abcdefg
+    """
+    print(isinstance(str_string, str) or type(str_string))
+    return str_string
+
+
+def str_type_is_str():
+    """
+    >>> str_type, s = str_type_is_str()
+    >>> isinstance(s, type(str_string)) or (s, str_type)
+    True
+    >>> isinstance(s, str_type) or (s, str_type)
+    True
+    >>> isinstance(str_string, str_type) or str_type
+    True
+    """
+    cdef str s = 'abc'
+    return str, s
+
+
+def annotation_syntax(a: "test new test", b : "other" = 2, *args: "ARGS", **kwargs: "KWARGS") -> "ret":
+    """
+    >>> annotation_syntax(1)
+    3
+    >>> annotation_syntax(1,3)
+    4
+
+    >>> len(annotation_syntax.__annotations__)
+    5
+    >>> annotation_syntax.__annotations__['a']
+    'test new test'
+    >>> annotation_syntax.__annotations__['b']
+    'other'
+    >>> annotation_syntax.__annotations__['args']
+    'ARGS'
+    >>> annotation_syntax.__annotations__['kwargs']
+    'KWARGS'
+    >>> annotation_syntax.__annotations__['return']
+    'ret'
+    """
+    result : int = a + b
+
+    return result

tests/run/ext_attr_getter.srctree

+PYTHON setup.py build_ext --inplace
+PYTHON -c "import runner"
+
+######## setup.py ########
+
+from Cython.Build.Dependencies import cythonize
+from distutils.core import setup
+
+# force the build order
+setup(ext_modules= cythonize("foo_extension.pyx"))
+
+setup(ext_modules = cythonize("getter*.pyx"))
+
+######## foo_nominal.h ########
+
+#include <Python.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    PyObject_HEAD
+    int f0;
+    int f1;
+    int f2;
+} FooStructNominal;
+
+#ifdef __cplusplus
+}
+#endif
+
+######## foo_extension.pyx ########
+
+cdef class Foo:
+    cdef public int field0, field1, field2;
+
+    def __init__(self, f0, f1, f2):
+        self.field0 = f0
+        self.field1 = f1
+        self.field2 = f2
+
+cdef get_field0(Foo f):
+    return f.field0
+
+cdef get_field1(Foo f):
+    return f.field1
+
+cdef get_field2(Foo f):
+    return f.field2
+
+# A pure-python class that disallows direct access to fields
+class OpaqueFoo(Foo):
+
+    @property
+    def field0(self):
+        raise AttributeError('no direct access to field0')
+
+    @property
+    def field1(self):
+        raise AttributeError('no direct access to field1')
+
+    @property
+    def field2(self):
+        raise AttributeError('no direct access to field2')
+
+
+######## getter0.pyx ########
+
+# Access base Foo fields from C via aliased field names
+
+cdef extern from "foo_nominal.h":
+
+    ctypedef class foo_extension.Foo [object FooStructNominal]:
+        cdef:
+            int field0 "f0"
+            int field1 "f1"
+            int field2 "f2"
+
+def sum(Foo f):
+    # the f.__getattr__('field0') is replaced in c by f->f0
+    return f.field0 + f.field1 + f.field2
+
+######## runner.py ########
+
+import foo_extension, getter0
+
+foo = foo_extension.Foo(23, 123, 1023)
+
+assert foo.field0 == 23
+assert foo.field1 == 123
+assert foo.field2 == 1023
+
+ret =  getter0.sum(foo)
+assert ret == foo.field0 + foo.field1 + foo.field2
+
+opaque_foo = foo_extension.OpaqueFoo(23, 123, 1023)
+
+# C can access the fields through the aliases
+opaque_ret = getter0.sum(opaque_foo)
+assert opaque_ret == ret
+try:
+    # Python cannot access the fields
+    f0 = opaque_ret.field0
+    assert False
+except AttributeError as e:
+    pass
+
+

tests/run/str_default_auto_encoding.pyx

-# cython: c_string_type = str
-# cython: c_string_encoding = default
+# cython: c_string_encoding=default
+# cython: c_string_type=str
+
+# NOTE: the directive order above is specifically meant to trigger (and confuse) the
+# source encoding detector with "coding=default".
 
 import sys
 if sys.version_info[0] >= 3: