#
#   Parse tree nodes
#


import cython

cython.declare(os=object, copy=object, chain=object,
               Builtin=object, error=object, warning=object, Naming=object, PyrexTypes=object,
               py_object_type=object, ModuleScope=object, LocalScope=object, ClosureScope=object,
               StructOrUnionScope=object, PyClassScope=object,
               CppClassScope=object, UtilityCode=object, EncodedString=object,
               error_type=object)

import copy
from itertools import chain
import enum

from . import Builtin
from .Errors import error, warning, InternalError, CompileError, CannotSpecialize
from . import Naming
from . import PyrexTypes
from . import TypeSlots
from .PyrexTypes import py_object_type, error_type
from .Symtab import (ModuleScope, LocalScope, ClosureScope, PropertyScope,
                     StructOrUnionScope, PyClassScope, CppClassScope, TemplateScope, GeneratorExpressionScope,
                     CppScopedEnumScope, punycodify_name)
from .Code import UtilityCode
from .StringEncoding import EncodedString
from . import Future
from . import Options
from . import DebugFlags
from .Pythran import has_np_pythran, pythran_type, is_pythran_buffer
from ..Utils import add_metaclass, str_to_number


IMPLICIT_CLASSMETHODS = {"__init_subclass__", "__class_getitem__"}


class NoGilState(enum.IntEnum):
    HasGil = 0
    NoGil = 1
    # For 'cdef func() nogil:' functions, as the GIL may be held while
    # calling this function (thus contained 'nogil' blocks may be valid).
    NoGilScope = 2


def relative_position(pos):
    return (pos[0].get_filenametable_entry(), pos[1])


def embed_position(pos, docstring):
    if not Options.embed_pos_in_docstring:
        return docstring
    pos_line = 'File: %s (starting at line %s)' % relative_position(pos)
    if docstring is None:
        # unicode string
        return EncodedString(pos_line)

    # make sure we can encode the filename in the docstring encoding
    # otherwise make the docstring a unicode string
    encoding = docstring.encoding
    if encoding is not None:
        try:
            pos_line.encode(encoding)
        except UnicodeEncodeError:
            encoding = None

    if not docstring:
        # reuse the string encoding of the original docstring
        doc = EncodedString(pos_line)
    else:
        doc = EncodedString(pos_line + '\n' + docstring)
    doc.encoding = encoding
    return doc


def write_func_call(func, codewriter_class):
    def f(*args, **kwds):
        if len(args) > 1 and isinstance(args[1], codewriter_class):
            # here we annotate the code with this function call
            # but only if new code is generated
            node, code = args[:2]
            marker = '                    /* %s -> %s.%s %s */' % (
                ' ' * code.call_level,
                node.__class__.__name__,
                func.__name__,
                node.pos[1:],
            )
            insertion_point = code.insertion_point()
            start = code.buffer.stream.tell()
            code.call_level += 4
            res = func(*args, **kwds)
            code.call_level -= 4
            if start != code.buffer.stream.tell():
                code.putln(marker.replace('->', '<-', 1))
                insertion_point.putln(marker)
            return res
        else:
            return func(*args, **kwds)
    return f


class VerboseCodeWriter(type):
    # Set this as a metaclass to trace function calls in code.
    # This slows down code generation and makes much larger files.
    def __new__(cls, name, bases, attrs):
        from types import FunctionType
        from .Code import CCodeWriter
        attrs = dict(attrs)
        for mname, m in attrs.items():
            if isinstance(m, FunctionType):
                attrs[mname] = write_func_call(m, CCodeWriter)
        return super().__new__(cls, name, bases, attrs)


class CheckAnalysers(type):
    """Metaclass to check that type analysis functions return a node.
    """
    methods = frozenset({
        'analyse_types',
        'analyse_expressions',
        'analyse_target_types',
    })

    def __new__(cls, name, bases, attrs):
        from types import FunctionType
        def check(name, func):
            def call(*args, **kwargs):
                retval = func(*args, **kwargs)
                if retval is None:
                    print('%s %s %s' % (name, args, kwargs))
                return retval
            return call

        attrs = dict(attrs)
        for mname, m in attrs.items():
            if isinstance(m, FunctionType) and mname in cls.methods:
                attrs[mname] = check(mname, m)
        return super().__new__(cls, name, bases, attrs)


class CopyWithUpTreeRefsMixin:
    def __deepcopy__(self, memo):
        # Any references to objects further up the tree should not be deep-copied.
        # However, if they're in memo (because they've already been deep-copied because
        # we're copying from far enough up the tree) then they should be replaced
        # with the memorised value.

        cls = self.__class__
        result = cls.__new__(cls)
        for k, v in self.__dict__.items():
            if k in self.uptree_ref_attrs:
                # Note that memo being keyed by "id" is a bit of an implementation detail;
                # the documentation says to treat it as opaque.
                v = memo.get(id(v), v)
            else:
                v = copy.deepcopy(v, memo)
            setattr(result, k, v)
        return result


def _with_metaclass(cls):
    if DebugFlags.debug_trace_code_generation:
        return add_metaclass(VerboseCodeWriter)(cls)
    #return add_metaclass(CheckAnalysers)(cls)
    return cls


@_with_metaclass
class Node:
    #  pos         (string, int, int)   Source file position
    #  is_name     boolean              Is a NameNode
    #  is_literal  boolean              Is a ConstNode

    is_name = 0
    is_none = 0
    is_nonecheck = 0
    is_literal = 0
    is_terminator = 0
    is_wrapper = False  # is a DefNode wrapper for a C function
    is_cproperty = False
    is_templated_type_node = False
    temps = None

    # All descendants should set child_attrs to a list of the attributes
    # containing nodes considered "children" in the tree. Each such attribute
    # can either contain a single node or a list of nodes. See Visitor.py.
    child_attrs = None

    # Subset of attributes that are evaluated in the outer scope (e.g. function default arguments).
    outer_attrs = None

    cf_state = None

    # This may be an additional (or 'actual') type that will be checked when
    # this node is coerced to another type. This could be useful to set when
    # the actual type to which it can coerce is known, but you want to leave
    # the type a py_object_type
    coercion_type = None

    def __init__(self, pos, **kw):
        self.pos = pos
        self.__dict__.update(kw)

    gil_message = "Operation"

    nogil_check = None
    in_nogil_context = False  # For use only during code generation.

    def gil_error(self, env=None):
        error(self.pos, "%s not allowed without gil" % self.gil_message)

    cpp_message = "Operation"

    def cpp_check(self, env):
        if not env.is_cpp():
            self.cpp_error()

    def cpp_error(self):
        error(self.pos, "%s only allowed in c++" % self.cpp_message)

    def clone_node(self):
        """Clone the node. This is defined as a shallow copy, except for member lists
           amongst the child attributes (from get_child_accessors) which are also
           copied. Lists containing child nodes are thus seen as a way for the node
           to hold multiple children directly; the list is not treated as a separate
           level in the tree."""
        result = copy.copy(self)
        for attrname in result.child_attrs:
            value = getattr(result, attrname)
            if isinstance(value, list):
                setattr(result, attrname, [x for x in value])
        return result


    #
    #  There are 3 main phases of parse tree processing, applied in order to
    #  all the statements in a given scope-block:
    #
    #  (0) analyse_declarations
    #        Make symbol table entries for all declarations at the current
    #        level, both explicit (def, cdef, etc.) and implicit (assignment
    #        to an otherwise undeclared name).
    #
    #  (1) analyse_expressions
    #         Determine the result types of expressions and fill in the
    #         'type' attribute of each ExprNode. Insert coercion nodes into the
    #         tree where needed to convert to and from Python objects.
    #         Replace tree nodes with more appropriate implementations found by
    #         the type analysis.
    #
    #  (2) generate_code
    #         Emit C code for all declarations, statements and expressions.
    #
    #  These phases are triggered by tree transformations.
    #  See the full pipeline in Pipeline.py.
    #

    def analyse_declarations(self, env):
        pass

    def analyse_expressions(self, env):
        raise InternalError("analyse_expressions not implemented for %s" %
            self.__class__.__name__)

    def generate_code(self, code):
        raise InternalError("generate_code not implemented for %s" %
            self.__class__.__name__)

    def annotate(self, code):
        # mro does the wrong thing
        if isinstance(self, BlockNode):
            self.body.annotate(code)

    def end_pos(self):
        try:
            return self._end_pos
        except AttributeError:
            pos = self.pos
            if not self.child_attrs:
                self._end_pos = pos
                return pos
            for attr in self.child_attrs:
                child = getattr(self, attr)
                # Sometimes lists, sometimes nodes
                if child is None:
                    pass
                elif isinstance(child, list):
                    for c in child:
                        pos = max(pos, c.end_pos())
                else:
                    pos = max(pos, child.end_pos())
            self._end_pos = pos
            return pos

    def dump(self, level=0, filter_out=("pos",), cutoff=100, encountered=None):
        """Debug helper method that returns a recursive string representation of this node.
        """
        if cutoff == 0:
            return "<...nesting level cutoff...>"
        if encountered is None:
            encountered = set()
        if id(self) in encountered:
            return "<%s (0x%x) -- already output>" % (self.__class__.__name__, id(self))
        encountered.add(id(self))

        def dump_child(x, level):
            if isinstance(x, Node):
                return x.dump(level, filter_out, cutoff-1, encountered)
            elif isinstance(x, list):
                return "[%s]" % ", ".join([dump_child(item, level) for item in x])
            else:
                return repr(x)

        attrs = [(key, value) for key, value in self.__dict__.items() if key not in filter_out]
        if len(attrs) == 0:
            return "<%s (0x%x)>" % (self.__class__.__name__, id(self))
        else:
            indent = "  " * level
            res = "<%s (0x%x)\n" % (self.__class__.__name__, id(self))
            for key, value in attrs:
                res += "%s  %s: %s\n" % (indent, key, dump_child(value, level + 1))
            res += "%s>" % indent
            return res

    def dump_pos(self, mark_column=False, marker='(#)'):
        """Debug helper method that returns the source code context of this node as a string.
        """
        if not self.pos:
            return ''
        source_desc, line, col = self.pos
        contents = source_desc.get_lines(encoding='ASCII', error_handling='ignore')
        # line numbers start at 1
        lines = contents[max(0, line-3):line]
        current = lines[-1]
        if mark_column:
            current = current[:col] + marker + current[col:]
        lines[-1] = current.rstrip() + '             # <<<<<<<<<<<<<<'
        lines += contents[line:line+2]

        code = '\n'.join(lines)
        return f'"{source_desc.get_escaped_description()}":{line:d}:{col:d}\n{code}\n'


class CompilerDirectivesNode(Node):
    """
    Sets compiler directives for the children nodes
    """
    #  directives     {string:value}  A dictionary holding the right value for
    #                                 *all* possible directives.
    #  body           Node
    child_attrs = ["body"]

    @classmethod
    def for_directives(cls, body, env, **directives):
        new_directives = Options.copy_inherited_directives(env.directives, **directives)
        return cls(body.pos, body=body, directives=new_directives, is_terminator=body.is_terminator)

    @classmethod
    def for_internal(cls, body, env):
        new_directives = Options.copy_for_internal(env.directives)
        return cls(body.pos, body=body, directives=new_directives, is_terminator=body.is_terminator)

    def analyse_declarations(self, env):
        old = env.directives
        env.directives = self.directives
        self.body.analyse_declarations(env)
        env.directives = old

    def analyse_expressions(self, env):
        old = env.directives
        env.directives = self.directives
        self.body = self.body.analyse_expressions(env)
        env.directives = old
        return self

    def generate_function_definitions(self, env, code):
        env_old = env.directives
        code_old = code.globalstate.directives
        code.globalstate.directives = self.directives
        self.body.generate_function_definitions(env, code)
        env.directives = env_old
        code.globalstate.directives = code_old

    def generate_execution_code(self, code):
        old = code.globalstate.directives
        code.globalstate.directives = self.directives
        self.body.generate_execution_code(code)
        code.globalstate.directives = old

    def annotate(self, code):
        old = code.globalstate.directives
        code.globalstate.directives = self.directives
        self.body.annotate(code)
        code.globalstate.directives = old


class BlockNode:
    #  Mixin class for nodes representing a declaration block.

    def generate_cached_builtins_decls(self, env, code):
        entries = env.global_scope().undeclared_cached_builtins
        for entry in entries:
            code.globalstate.add_cached_builtin_decl(entry)
        del entries[:]

    def generate_lambda_definitions(self, env, code):
        for node in env.lambda_defs:
            node.generate_function_definitions(env, code)


class StatListNode(Node):
    # stats     a list of StatNode

    child_attrs = ["stats"]

    @staticmethod
    def create_analysed(pos, env, **kw):
        node = StatListNode(pos, **kw)
        return node  # No node-specific analysis needed

    def analyse_declarations(self, env):
        #print "StatListNode.analyse_declarations" ###
        for stat in self.stats:
            stat.analyse_declarations(env)

    def analyse_expressions(self, env):
        #print "StatListNode.analyse_expressions" ###
        self.stats = [stat.analyse_expressions(env)
                      for stat in self.stats]
        return self

    def generate_function_definitions(self, env, code):
        #print "StatListNode.generate_function_definitions" ###
        for stat in self.stats:
            stat.generate_function_definitions(env, code)

    def generate_execution_code(self, code):
        #print "StatListNode.generate_execution_code" ###
        for stat in self.stats:
            code.mark_pos(stat.pos)
            stat.generate_execution_code(code)

    def annotate(self, code):
        for stat in self.stats:
            stat.annotate(code)


class StatNode(Node):
    #
    #  Code generation for statements is split into the following subphases:
    #
    #  (1) generate_function_definitions
    #        Emit C code for the definitions of any structs,
    #        unions, enums and functions defined in the current
    #        scope-block.
    #
    #  (2) generate_execution_code
    #        Emit C code for executable statements.
    #

    def generate_function_definitions(self, env, code):
        pass

    def generate_execution_code(self, code):
        raise InternalError("generate_execution_code not implemented for %s" %
            self.__class__.__name__)


class CDefExternNode(StatNode):
    #  include_file       string or None
    #  verbatim_include   string or None
    #  body               StatListNode

    child_attrs = ["body"]

    def analyse_declarations(self, env):
        old_cinclude_flag = env.in_cinclude
        env.in_cinclude = 1
        self.body.analyse_declarations(env)
        env.in_cinclude = old_cinclude_flag

        if self.include_file or self.verbatim_include:
            # Determine whether include should be late
            stats = self.body.stats
            if not env.directives['preliminary_late_includes_cy28']:
                late = False
            elif not stats:
                # Special case: empty 'cdef extern' blocks are early
                late = False
            else:
                late = all(isinstance(node, CVarDefNode) for node in stats)
            env.add_include_file(self.include_file, self.verbatim_include, late)

    def analyse_expressions(self, env):
        # Allow C properties, inline methods, etc. also in external types.
        self.body = self.body.analyse_expressions(env)
        return self

    def generate_function_definitions(self, env, code):
        self.body.generate_function_definitions(env, code)

    def generate_execution_code(self, code):
        pass

    def annotate(self, code):
        self.body.annotate(code)


class CDeclaratorNode(Node):
    # Part of a C declaration.
    #
    # Processing during analyse_declarations phase:
    #
    #   analyse
    #      Returns (name, type) pair where name is the
    #      CNameDeclaratorNode of the name being declared
    #      and type is the type it is being declared as.
    #
    #  calling_convention  string   Calling convention of CFuncDeclaratorNode
    #                               for which this is a base

    child_attrs = []

    calling_convention = ""

    def declared_name(self):
        return None

    def analyse_templates(self):
        # Only C++ functions have templates.
        return None


class CNameDeclaratorNode(CDeclaratorNode):
    #  name    string             The Cython name being declared
    #  cname   string or None     C name, if specified
    #  default ExprNode or None   the value assigned on declaration

    child_attrs = ['default']

    default = None

    def declared_name(self):
        return self.name

    def analyse(self, base_type, env, nonempty=0, visibility=None, in_pxd=False):
        if nonempty and self.name == '':
            # May have mistaken the name for the type.
            if base_type.is_ptr or base_type.is_array or base_type.is_buffer:
                error(self.pos, "Missing argument name")
            elif base_type.is_void:
                error(self.pos, "Use spam() rather than spam(void) to declare a function with no arguments.")
            else:
                self.name = base_type.declaration_code("", for_display=1, pyrex=1)
                base_type = py_object_type

        if base_type.is_fused and env.fused_to_specific:
            try:
                base_type = base_type.specialize(env.fused_to_specific)
            except CannotSpecialize:
                error(self.pos,
                      "'%s' cannot be specialized since its type is not a fused argument to this function" %
                      self.name)

        self.type = base_type
        return self, base_type


class CPtrDeclaratorNode(CDeclaratorNode):
    # base     CDeclaratorNode

    child_attrs = ["base"]

    def declared_name(self):
        return self.base.declared_name()

    def analyse_templates(self):
        return self.base.analyse_templates()

    def analyse(self, base_type, env, nonempty=0, visibility=None, in_pxd=False):
        if base_type.is_pyobject:
            error(self.pos, "Pointer base type cannot be a Python object")
        ptr_type = PyrexTypes.c_ptr_type(base_type)
        return self.base.analyse(ptr_type, env, nonempty=nonempty, visibility=visibility, in_pxd=in_pxd)


class _CReferenceDeclaratorBaseNode(CDeclaratorNode):
    child_attrs = ["base"]

    def declared_name(self):
        return self.base.declared_name()

    def analyse_templates(self):
        return self.base.analyse_templates()


class CReferenceDeclaratorNode(_CReferenceDeclaratorBaseNode):
    def analyse(self, base_type, env, nonempty=0, visibility=None, in_pxd=False):
        if base_type.is_pyobject:
            error(self.pos, "Reference base type cannot be a Python object")
        ref_type = PyrexTypes.c_ref_type(base_type)
        return self.base.analyse(ref_type, env, nonempty=nonempty, visibility=visibility, in_pxd=in_pxd)


class CppRvalueReferenceDeclaratorNode(_CReferenceDeclaratorBaseNode):
    def analyse(self, base_type, env, nonempty=0, visibility=None, in_pxd=False):
        if base_type.is_pyobject:
            error(self.pos, "Rvalue-reference base type cannot be a Python object")
        ref_type = PyrexTypes.cpp_rvalue_ref_type(base_type)
        return self.base.analyse(ref_type, env, nonempty=nonempty, visibility=visibility, in_pxd=in_pxd)


class CArrayDeclaratorNode(CDeclaratorNode):
    # base        CDeclaratorNode
    # dimension   ExprNode

    child_attrs = ["base", "dimension"]

    def analyse(self, base_type, env, nonempty=0, visibility=None, in_pxd=False):
        if ((base_type.is_cpp_class and base_type.is_template_type()) or
                base_type.is_cfunction or
                base_type.python_type_constructor_name):
            from .ExprNodes import TupleNode
            if isinstance(self.dimension, TupleNode):
                args = self.dimension.args
            else:
                args = self.dimension,
            values = [v.analyse_as_type(env) for v in args]
            if None in values:
                ix = values.index(None)
                error(args[ix].pos, "Template parameter not a type")
                base_type = error_type
            else:
                base_type = base_type.specialize_here(self.pos, env, values)
            return self.base.analyse(base_type, env, nonempty=nonempty, visibility=visibility, in_pxd=in_pxd)

        size = None
        if self.dimension:
            self.dimension = self.dimension.analyse_const_expression(env)
            if not self.dimension.type.is_int:
                error(self.dimension.pos, "Array dimension not integer")
            if self.dimension.type.is_const and self.dimension.entry.visibility != 'extern':
                # extern const variables declaring C constants are allowed
                error(self.dimension.pos, "Array dimension cannot be const variable")
            size = (self.dimension.constant_result if isinstance(self.dimension.constant_result, int)
                    else self.dimension.get_constant_c_result_code())
            try:
                size = int(size)
            except ValueError:
                # runtime constant?
                pass

        if not base_type.is_complete():
            error(self.pos, "Array element type '%s' is incomplete" % base_type)
        if base_type.is_pyobject:
            error(self.pos, "Array element cannot be a Python object")
        if base_type.is_cfunction:
            error(self.pos, "Array element cannot be a function")
        array_type = PyrexTypes.c_array_type(base_type, size)
        return self.base.analyse(array_type, env, nonempty=nonempty, visibility=visibility, in_pxd=in_pxd)


class CFuncDeclaratorNode(CDeclaratorNode):
    # base                      CDeclaratorNode
    # args                      [CArgDeclNode]
    # templates                 [TemplatePlaceholderType]
    # has_varargs               boolean
    # exception_value           ConstNode or NameNode    NameNode when the name of a c++ exception conversion function
    # exception_check           boolean or "+"    True if PyErr_Occurred check needed, "+" for a c++ check
    # has_explicit_exc_clause   boolean    True if exception clause is explicitly declared
    # nogil                     boolean    Can be called without gil
    # with_gil                  boolean    Acquire gil around function body
    # is_const_method           boolean    Whether this is a const method

    child_attrs = ["base", "args", "exception_value"]

    overridable = 0
    optional_arg_count = 0
    is_const_method = 0
    templates = None

    def declared_name(self):
        return self.base.declared_name()

    def analyse_templates(self):
        if isinstance(self.base, CArrayDeclaratorNode):
            from .ExprNodes import TupleNode, NameNode
            template_node = self.base.dimension
            if isinstance(template_node, TupleNode):
                template_nodes = template_node.args
            elif isinstance(template_node, NameNode):
                template_nodes = [template_node]
            else:
                error(template_node.pos, "Template arguments must be a list of names")
                return None
            self.templates = []
            for template in template_nodes:
                if isinstance(template, NameNode):
                    self.templates.append(PyrexTypes.TemplatePlaceholderType(template.name))
                else:
                    error(template.pos, "Template arguments must be a list of names")
            self.base = self.base.base
            return self.templates
        else:
            return None

    def analyse(self, return_type, env, nonempty=0, directive_locals=None, visibility=None, in_pxd=False):
        if directive_locals is None:
            directive_locals = {}
        if nonempty:
            nonempty -= 1
        func_type_args = []
        for i, arg_node in enumerate(self.args):
            name_declarator, type = arg_node.analyse(
                env, nonempty=nonempty,
                is_self_arg=(i == 0 and env.is_c_class_scope and 'staticmethod' not in env.directives))
            name = name_declarator.name
            if name in directive_locals:
                type_node = directive_locals[name]
                other_type = type_node.analyse_as_type(env)
                if other_type is None:
                    error(type_node.pos, "Not a type")
                elif (type is not PyrexTypes.py_object_type
                      and not type.same_as(other_type)):
                    error(self.base.pos, "Signature does not agree with previous declaration")
                    error(type_node.pos, "Previous declaration here")
                else:
                    type = other_type
            if name_declarator.cname:
                error(self.pos, "Function argument cannot have C name specification")
            if i == 0 and env.is_c_class_scope and type.is_unspecified:
                # fix the type of self
                type = env.parent_type
            # Turn *[] argument into **
            if type.is_array:
                type = PyrexTypes.c_ptr_type(type.base_type)
            # Catch attempted C-style func(void) decl
            if type.is_void:
                error(arg_node.pos, "Use spam() rather than spam(void) to declare a function with no arguments.")
            func_arg = PyrexTypes.CFuncTypeArg(name, type, arg_node.pos)
            if arg_node.not_none:
                func_arg.not_none = True
            if arg_node.or_none:
                func_arg.or_none = True
            func_type_args.append(func_arg)
            if arg_node.default:
                self.optional_arg_count += 1
            elif self.optional_arg_count:
                error(self.pos, "Non-default argument follows default argument")

        exc_val = None
        exc_check = 0

        if (env.directives["legacy_implicit_noexcept"]
                and not return_type.is_pyobject
                and not self.has_explicit_exc_clause
                and self.exception_check
                and visibility != 'extern'):
            # implicit noexcept, with a warning
            self.exception_check = False
            warning(self.pos,
                    "Implicit noexcept declaration is deprecated."
                    " Function declaration should contain 'noexcept' keyword.",
                    level=2)

        if self.exception_check == '+':
            self.cpp_check(env)
            env.add_include_file('ios')         # for std::ios_base::failure
            env.add_include_file('new')         # for std::bad_alloc
            env.add_include_file('stdexcept')
            env.add_include_file('typeinfo')    # for std::bad_cast
        elif return_type.is_pyobject and self.exception_check:
            # Functions in pure Python mode default to always check return values for exceptions
            # (equivalent to the "except*" declaration). In this case, the exception clause
            # is silently ignored for functions returning a Python object.
            self.exception_check = False

        if (return_type.is_pyobject
                and (self.exception_value or self.exception_check)
                and self.exception_check != '+'):
            error(self.pos, "Exception clause not allowed for function returning Python object")
        elif return_type.is_pyobject and not self.exception_check and visibility != 'extern' and self.has_explicit_exc_clause:
            warning(self.pos, "noexcept clause is ignored for function returning Python object", 1)
        else:
            if self.exception_value is None and self.exception_check and self.exception_check != '+':
                # Use an explicit exception return value to speed up exception checks.
                # Even if it is not declared, we can use the default exception value of the return type,
                # unless the function is some kind of external function that we do not control.
                if (return_type.exception_value is not None and (visibility != 'extern' and not in_pxd)):
                    # - We skip this optimization for extension types; they are more difficult because
                    #   the signature must match the base type signature.
                    # - Same for function pointers, as we want them to be able to match functions
                    #   with any exception value.
                    # - Ideally the function-pointer test would be better after self.base is analysed
                    #   however that is hard to do with the current implementation so it lives here
                    #   for now.
                    if not env.is_c_class_scope and not isinstance(self.base, CPtrDeclaratorNode):
                        from .ExprNodes import ConstNode
                        self.exception_value = ConstNode.for_type(
                            self.pos, value=str(return_type.exception_value), type=return_type,
                            constant_result=return_type.exception_value)
            if self.exception_value is not None:
                if self.exception_check == '+':
                    self.exception_value = self.exception_value.analyse_const_expression(env)
                    exc_val_type = self.exception_value.type
                    if (not exc_val_type.is_error
                            and not exc_val_type.is_pyobject
                            and not (exc_val_type.is_cfunction
                                     and not exc_val_type.return_type.is_pyobject
                                     and not exc_val_type.args)
                            and not (exc_val_type == PyrexTypes.c_char_type
                                     and self.exception_value.value == '*')):
                        error(self.exception_value.pos,
                              "Exception value must be a Python exception, or C++ function with no arguments, or *.")
                    exc_val = self.exception_value
                else:
                    self.exception_value = self.exception_value.analyse_types(env).coerce_to(
                        return_type, env).analyse_const_expression(env)
                    exc_val = self.exception_value.as_exception_value(env)
                    if not return_type.assignable_from(self.exception_value.type):
                        error(self.exception_value.pos,
                              "Exception value incompatible with function return type")
                    if (visibility != 'extern'
                            and (return_type.is_int or return_type.is_float)
                            and self.exception_value.has_constant_result()):
                        try:
                            type_default_value = float(return_type.default_value)
                        except ValueError:
                            pass
                        else:
                            if self.exception_value.constant_result == type_default_value:
                                warning(self.pos, "Ambiguous exception value, same as default return value: %r" %
                                        self.exception_value.constant_result)
            exc_check = self.exception_check
        if return_type.is_cfunction:
            error(self.pos, "Function cannot return a function")
        func_type = PyrexTypes.CFuncType(
            return_type, func_type_args, self.has_varargs,
            optional_arg_count=self.optional_arg_count,
            exception_value=exc_val, exception_check=exc_check,
            calling_convention=self.base.calling_convention,
            nogil=self.nogil, with_gil=self.with_gil, is_overridable=self.overridable,
            is_const_method=self.is_const_method,
            templates=self.templates)

        if self.optional_arg_count:
            if func_type.is_fused:
                # This is a bit of a hack... When we need to create specialized CFuncTypes
                # on the fly because the cdef is defined in a pxd, we need to declare the specialized optional arg
                # struct
                def declare_opt_arg_struct(func_type, fused_cname):
                    self.declare_optional_arg_struct(func_type, env, fused_cname)

                func_type.declare_opt_arg_struct = declare_opt_arg_struct
            else:
                self.declare_optional_arg_struct(func_type, env)

        callspec = env.directives['callspec']
        if callspec:
            current = func_type.calling_convention
            if current and current != callspec:
                error(self.pos, "cannot have both '%s' and '%s' "
                      "calling conventions" % (current, callspec))
            func_type.calling_convention = callspec

        if func_type.return_type.is_rvalue_reference:
            warning(self.pos, "Rvalue-reference as function return type not supported", 1)
        for arg in func_type.args:
            if arg.type.is_rvalue_reference and not arg.is_forwarding_reference():
                warning(self.pos, "Rvalue-reference as function argument not supported", 1)

        return self.base.analyse(func_type, env, visibility=visibility, in_pxd=in_pxd)

    def declare_optional_arg_struct(self, func_type, env, fused_cname=None):
        """
        Declares the optional argument struct (the struct used to hold the
        values for optional arguments). For fused cdef functions, this is
        deferred as analyse_declarations is called only once (on the fused
        cdef function).
        """
        scope = StructOrUnionScope()
        arg_count_member = '%sn' % Naming.pyrex_prefix
        scope.declare_var(arg_count_member, PyrexTypes.c_int_type, self.pos)

        for arg in func_type.args[len(func_type.args) - self.optional_arg_count:]:
            scope.declare_var(arg.name, arg.type, arg.pos, allow_pyobject=True, allow_memoryview=True)

        struct_cname = env.mangle(Naming.opt_arg_prefix, self.base.name)

        if fused_cname is not None:
            struct_cname = PyrexTypes.get_fused_cname(fused_cname, struct_cname)

        op_args_struct = env.global_scope().declare_struct_or_union(
            name=struct_cname,
            kind='struct',
            scope=scope,
            typedef_flag=0,
            pos=self.pos,
            cname=struct_cname)

        op_args_struct.defined_in_pxd = 1
        op_args_struct.used = 1

        func_type.op_arg_struct = PyrexTypes.c_ptr_type(op_args_struct.type)


class CConstDeclaratorNode(CDeclaratorNode):
    # base     CDeclaratorNode

    child_attrs = ["base"]

    def analyse(self, base_type, env, nonempty=0, visibility=None, in_pxd=False):
        if base_type.is_pyobject:
            error(self.pos,
                  "Const base type cannot be a Python object")
        const = PyrexTypes.c_const_type(base_type)
        return self.base.analyse(const, env, nonempty=nonempty, visibility=visibility, in_pxd=in_pxd)


class CArgDeclNode(Node):
    # Item in a function declaration argument list.
    #
    # base_type      CBaseTypeNode
    # declarator     CDeclaratorNode
    # not_none       boolean            Tagged with 'not None'
    # or_none        boolean            Tagged with 'or None'
    # accept_none    boolean            Resolved boolean for not_none/or_none
    # default        ExprNode or None
    # default_value  PyObjectConst      constant for default value
    # annotation     ExprNode or None   Py3 function arg annotation
    # is_self_arg    boolean            Is the "self" arg of an extension type method
    # is_type_arg    boolean            Is the "class" arg of an extension type classmethod
    # kw_only        boolean            Is a keyword-only argument
    # is_dynamic     boolean            Non-literal arg stored inside CyFunction
    # pos_only       boolean            Is a positional-only argument
    # type_from_annotation boolean      Was the type deduced from an annotation
    #
    # name_cstring                         property that converts the name to a cstring taking care of unicode
    #                                      and quoting it
    # defaults_class_key  None or string  Name used to lookup this arg in the defaults class

    child_attrs = ["base_type", "declarator", "default", "annotation"]
    outer_attrs = ["default", "annotation"]

    is_self_arg = 0
    is_type_arg = 0
    is_generic = 1
    is_special_method_optional = False
    kw_only = 0
    pos_only = 0
    not_none = 0
    or_none = 0
    type = None
    name_declarator = None
    default_value = None
    annotation = None
    is_dynamic = 0
    defaults_class_key = None
    type_from_annotation = False

    def declared_name(self):
        return self.declarator.declared_name()

    @property
    def name_cstring(self):
        return self.name.as_c_string_literal()

    @property
    def hdr_cname(self):
        # done lazily - needs self.entry to be set to get the class-mangled
        # name, which means it has to be generated relatively late
        if self.needs_conversion:
            return punycodify_name(Naming.arg_prefix + self.entry.name)
        else:
            return punycodify_name(Naming.var_prefix + self.entry.name)


    def analyse(self, env, nonempty=0, is_self_arg=False):
        if is_self_arg:
            self.base_type.is_self_arg = self.is_self_arg = is_self_arg
        if self.type is not None:
            return self.name_declarator, self.type

        # The parser may misinterpret names as types. We fix that here.
        if isinstance(self.declarator, CNameDeclaratorNode) and self.declarator.name == '':
            if nonempty:
                if self.base_type.is_basic_c_type:
                    # char, short, long called "int"
                    type = self.base_type.analyse(env, could_be_name=True)
                    arg_name = type.empty_declaration_code()
                else:
                    arg_name = self.base_type.name
                self.declarator.name = EncodedString(arg_name)
                self.base_type.name = None
                self.base_type.is_basic_c_type = False
            could_be_name = True
        else:
            could_be_name = False
        self.base_type.is_arg = True
        base_type = self.base_type.analyse(env, could_be_name=could_be_name)
        base_arg_name = getattr(self.base_type, 'arg_name', None)
        if base_arg_name:
            self.declarator.name = base_arg_name

        # The parser is unable to resolve the ambiguity of [] as part of the
        # type (e.g. in buffers) or empty declarator (as with arrays).
        # This is only arises for empty multi-dimensional arrays.
        if (base_type.is_array
                and isinstance(self.base_type, TemplatedTypeNode)
                and isinstance(self.declarator, CArrayDeclaratorNode)):
            declarator = self.declarator
            while isinstance(declarator.base, CArrayDeclaratorNode):
                declarator = declarator.base
            declarator.base = self.base_type.array_declarator
            base_type = base_type.base_type

        # inject type declaration from annotations
        # this is called without 'env' by AdjustDefByDirectives transform before declaration analysis
        if (self.annotation and env and env.directives['annotation_typing']
                # CSimpleBaseTypeNode has a name attribute; CAnalysedBaseTypeNode
                # (and maybe other options) doesn't
                and getattr(self.base_type, "name", None) is None):
            arg_type = self.inject_type_from_annotations(env)
            if arg_type is not None:
                base_type = arg_type
        return self.declarator.analyse(base_type, env, nonempty=nonempty)

    def inject_type_from_annotations(self, env):
        annotation = self.annotation
        if not annotation:
            return None

        modifiers, arg_type = annotation.analyse_type_annotation(env, assigned_value=self.default)
        if arg_type is not None:
            self.base_type = CAnalysedBaseTypeNode(
                annotation.pos, type=arg_type, is_arg=True)

        if arg_type:
            if "typing.Optional" in modifiers:
                # "x: Optional[...]"  =>  explicitly allow 'None'
                arg_type = arg_type.resolve()
                if arg_type and not arg_type.can_be_optional():
                    # We probably already reported this as "cannot be applied to non-Python type".
                    # error(annotation.pos, "Only Python type arguments can use typing.Optional[...]")
                    pass
                else:
                    self.or_none = True
            elif arg_type is py_object_type:
                # exclude ": object" from the None check - None is a generic object.
                self.or_none = True
            elif self.default and self.default.is_none and (arg_type.can_be_optional() or arg_type.equivalent_type):
                # "x: ... = None"  =>  implicitly allow 'None'
                if not arg_type.can_be_optional():
                    arg_type = arg_type.equivalent_type
                if not self.or_none:
                    warning(self.pos, "PEP-484 recommends 'typing.Optional[...]' for arguments that can be None.")
                    self.or_none = True
            elif not self.or_none and arg_type.can_be_optional():
                self.not_none = True

        if arg_type:
            self.type_from_annotation = True
        return arg_type

    def calculate_default_value_code(self, code):
        if self.default_value is None:
            if self.default:
                if self.default.is_literal:
                    # will not output any code, just assign the result_code
                    self.default.generate_evaluation_code(code)
                    return self.type.cast_code(self.default.result())
                self.default_value = code.get_argument_default_const(self.type)
        return self.default_value

    def annotate(self, code):
        if self.default:
            self.default.annotate(code)

    def generate_assignment_code(self, code, target=None, overloaded_assignment=False):
        default = self.default
        if default is None or default.is_literal:
            return
        if target is None:
            target = self.calculate_default_value_code(code)
        default.generate_evaluation_code(code)
        default.make_owned_reference(code)
        result = default.result() if overloaded_assignment else default.result_as(self.type)
        code.putln("%s = %s;" % (target, result))
        code.put_giveref(default.result(), self.type)
        default.generate_post_assignment_code(code)
        default.free_temps(code)


class CBaseTypeNode(Node):
    # Abstract base class for C base type nodes.
    #
    # Processing during analyse_declarations phase:
    #
    #   analyse
    #     Returns the type.

    def analyse_as_type(self, env):
        return self.analyse(env)


class CAnalysedBaseTypeNode(Node):
    # type            type

    child_attrs = []

    def analyse(self, env, could_be_name=False):
        return self.type


class CSimpleBaseTypeNode(CBaseTypeNode):
    # name             string
    # module_path      [string]     Qualifying name components
    # is_basic_c_type  boolean
    # signed           boolean
    # longness         integer
    # complex          boolean
    # is_self_arg      boolean      Is self argument of C method
    # ##is_type_arg      boolean      Is type argument of class method

    child_attrs = []
    arg_name = None   # in case the argument name was interpreted as a type
    module_path = []
    is_basic_c_type = False
    complex = False
    is_self_arg = False

    def analyse(self, env, could_be_name=False):
        # Return type descriptor.
        #print "CSimpleBaseTypeNode.analyse: is_self_arg =", self.is_self_arg ###
        type = None
        if self.is_basic_c_type:
            type = PyrexTypes.simple_c_type(self.signed, self.longness, self.name)
            if not type:
                error(self.pos, "Unrecognised type modifier combination")
        elif self.name == "object" and not self.module_path:
            type = py_object_type
        elif self.name is None:
            if self.is_self_arg and env.is_c_class_scope:
                #print "CSimpleBaseTypeNode.analyse: defaulting to parent type" ###
                type = env.parent_type
            ## elif self.is_type_arg and env.is_c_class_scope:
            ##     type = Builtin.type_type
            else:
                type = py_object_type
        else:
            scope = env
            if self.module_path:
                # Maybe it's a nested C++ class.
                for item in self.module_path:
                    entry = scope.lookup(item)
                    if entry is not None and (
                        entry.is_cpp_class or
                        entry.is_type and entry.type.is_cpp_class
                    ):
                        scope = entry.type.scope
                    elif entry and entry.as_module:
                        scope = entry.as_module
                    else:
                        scope = None
                        break
                if scope is None and len(self.module_path) == 1:
                    # (may be possible to handle longer module paths?)
                    # TODO: probably not the best place to declare it?
                    from .Builtin import get_known_standard_library_module_scope
                    found_entry = env.lookup(self.module_path[0])
                    if found_entry and found_entry.known_standard_library_import:
                        scope = get_known_standard_library_module_scope(found_entry.known_standard_library_import)
                if scope is None:
                    # Maybe it's a cimport.
                    scope = env.find_imported_module(self.module_path, self.pos)

            if scope:
                if scope.is_c_class_scope:
                    scope = scope.global_scope()

                type = scope.lookup_type(self.name)
                if type is not None:
                    pass
                elif could_be_name:
                    if self.is_self_arg and env.is_c_class_scope:
                        type = env.parent_type
                    ## elif self.is_type_arg and env.is_c_class_scope:
                    ##     type = Builtin.type_type
                    else:
                        type = py_object_type
                    self.arg_name = EncodedString(self.name)
                else:
                    if self.templates:
                        if self.name not in self.templates:
                            error(self.pos, "'%s' is not a type identifier" % self.name)
                        type = PyrexTypes.TemplatePlaceholderType(self.name)
                    else:
                        error(self.pos, "'%s' is not a type identifier" % self.name)
        if type and type.is_fused and env.fused_to_specific:
            type = type.specialize(env.fused_to_specific)
        if self.complex:
            if not type.is_numeric or type.is_complex:
                error(self.pos, "can only complexify c numeric types")
            type = PyrexTypes.CComplexType(type)
            type.create_declaration_utility_code(env)
        elif type is Builtin.complex_type:
            # Special case: optimise builtin complex type into C's
            # double complex.  The parser cannot do this (as for the
            # normal scalar types) as the user may have redeclared the
            # 'complex' type.  Testing for the exact type here works.
            type = PyrexTypes.c_double_complex_type
            type.create_declaration_utility_code(env)
            self.complex = True
        if not type:
            type = PyrexTypes.error_type
        return type

class MemoryViewSliceTypeNode(CBaseTypeNode):

    name = 'memoryview'
    child_attrs = ['base_type_node', 'axes']

    def analyse(self, env, could_be_name=False):

        base_type = self.base_type_node.analyse(env)
        if base_type.is_error: return base_type

        from . import MemoryView

        try:
            axes_specs = MemoryView.get_axes_specs(env, self.axes)
        except CompileError as e:
            error(e.position, e.message_only)
            self.type = PyrexTypes.ErrorType()
            return self.type

        if not MemoryView.validate_axes(self.pos, axes_specs):
            self.type = error_type
        else:
            self.type = PyrexTypes.MemoryViewSliceType(base_type, axes_specs)
            self.type.validate_memslice_dtype(self.pos)
            self.use_memview_utilities(env)

        return self.type

    def use_memview_utilities(self, env):
        from . import MemoryView
        env.use_utility_code(
            MemoryView.get_view_utility_code(
                env.context.shared_utility_qualified_name
            )
        )


class CNestedBaseTypeNode(CBaseTypeNode):
    # For C++ classes that live inside other C++ classes.

    # name             string
    # base_type        CBaseTypeNode

    child_attrs = ['base_type']

    def analyse(self, env, could_be_name=None):
        base_type = self.base_type.analyse(env)
        if base_type is PyrexTypes.error_type:
            return PyrexTypes.error_type
        if not base_type.is_cpp_class:
            error(self.pos, "'%s' is not a valid type scope" % base_type)
            return PyrexTypes.error_type
        type_entry = base_type.scope.lookup_here(self.name)
        if not type_entry or not type_entry.is_type:
            error(self.pos, "'%s.%s' is not a type identifier" % (base_type, self.name))
            return PyrexTypes.error_type
        return type_entry.type


class TemplatedTypeNode(CBaseTypeNode):
    #  After parsing:
    #  positional_args  [ExprNode]        List of positional arguments
    #  keyword_args     DictNode          Keyword arguments
    #  base_type_node   CBaseTypeNode

    #  After analysis:
    #  type             PyrexTypes.BufferType or PyrexTypes.CppClassType  ...containing the right options

    child_attrs = ["base_type_node", "positional_args",
                   "keyword_args", "dtype_node"]

    is_templated_type_node = True
    dtype_node = None
    name = None

    def _analyse_template_types(self, env, base_type):
        require_python_types = base_type.python_type_constructor_name == 'dataclasses.ClassVar'

        in_c_type_context = env.in_c_type_context and not require_python_types

        template_types = []
        for template_node in self.positional_args:
            if template_node.is_none:
                continue
            # CBaseTypeNode -> allow C type declarations in a 'cdef' context again
            with env.new_c_type_context(in_c_type_context or isinstance(template_node, CBaseTypeNode)):
                ttype = template_node.analyse_as_type(env)
            if ttype is None:
                if base_type.is_cpp_class:
                    error(template_node.pos, "unknown type in template argument")
                    ttype = error_type
                # For Python generics we can be a bit more flexible and allow None.
            template_types.append(ttype)

        if base_type.python_type_constructor_name:
            if base_type.python_type_constructor_name == 'typing.Union':
                base_type.contains_none = any(x.is_none for x in self.positional_args)
            require_optional_types = base_type.allows_none()
        else:
            require_optional_types = False

        for i, ttype in enumerate(template_types):
            if ttype is None:
                continue
            if require_python_types and not ttype.is_pyobject or require_optional_types and not ttype.can_be_optional():
                if ttype.equivalent_type and not template_node.as_cython_attribute():
                    template_types[i] = ttype.equivalent_type
                else:
                    error(template_node.pos, "%s[...] cannot be applied to type %s" % (
                        base_type.python_type_constructor_name,
                        ttype,
                    ))
                    template_types[i] = error_type


        return template_types

    def analyse(self, env, could_be_name=False, base_type=None):
        if base_type is None:
            base_type = self.base_type_node.analyse(env)
        if base_type.is_error: return base_type

        if ((base_type.is_cpp_class and base_type.is_template_type()) or
                base_type.python_type_constructor_name):
            # Templated class, Python generics, etc.
            if self.keyword_args and self.keyword_args.key_value_pairs:
                tp = "c++ templates" if base_type.is_cpp_class else "indexed types"
                error(self.pos, "%s cannot take keyword arguments" % tp)
                self.type = PyrexTypes.error_type
                return self.type

            template_types = self._analyse_template_types(env, base_type)
            self.type = base_type.specialize_here(self.pos, env, template_types)

        elif base_type.is_pyobject:
            # Buffer
            from . import Buffer

            options = Buffer.analyse_buffer_options(
                self.pos,
                env,
                self.positional_args,
                self.keyword_args,
                base_type.buffer_defaults)

            self.type = PyrexTypes.BufferType(base_type, **options)
            if has_np_pythran(env) and is_pythran_buffer(self.type):
                self.type = PyrexTypes.PythranExpr(pythran_type(self.type), self.type)

        else:
            # Array
            empty_declarator = CNameDeclaratorNode(self.pos, name="", cname=None)
            if len(self.positional_args) > 1 or self.keyword_args.key_value_pairs:
                error(self.pos, "invalid array declaration")
                self.type = PyrexTypes.error_type
            else:
                # It would be nice to merge this class with CArrayDeclaratorNode,
                # but arrays are part of the declaration, not the type...
                if not self.positional_args:
                    dimension = None
                else:
                    dimension = self.positional_args[0]
                self.array_declarator = CArrayDeclaratorNode(
                    self.pos,
                    base=empty_declarator,
                    dimension=dimension)
                self.type = self.array_declarator.analyse(base_type, env)[1]

        if self.type and self.type.is_fused and env.fused_to_specific:
            try:
                self.type = self.type.specialize(env.fused_to_specific)
            except CannotSpecialize:
                error(self.pos,
                      "'%s' cannot be specialized since its type is not a fused argument to this function" %
                      self.name)

        return self.type

    def analyse_pytyping_modifiers(self, env):
        # Check for declaration modifiers, e.g. "typing.Optional[...]" or "dataclasses.InitVar[...]"
        # TODO: somehow bring this together with IndexNode.analyse_pytyping_modifiers()
        modifiers = []
        modifier_node = self
        while modifier_node.is_templated_type_node and modifier_node.base_type_node and len(modifier_node.positional_args) == 1:
            modifier_type = self.base_type_node.analyse_as_type(env)
            if modifier_type.python_type_constructor_name and modifier_type.modifier_name:
                modifiers.append(modifier_type.modifier_name)
            modifier_node = modifier_node.positional_args[0]

        return modifiers


class CComplexBaseTypeNode(CBaseTypeNode):
    # base_type   CBaseTypeNode
    # declarator  CDeclaratorNode

    child_attrs = ["base_type", "declarator"]

    def analyse(self, env, could_be_name=False):
        base = self.base_type.analyse(env, could_be_name)
        _, type = self.declarator.analyse(base, env)
        return type


class CTupleBaseTypeNode(CBaseTypeNode):
    # components [CBaseTypeNode]

    child_attrs = ["components"]

    def analyse(self, env, could_be_name=False):
        component_types = []
        for c in self.components:
            type = c.analyse(env)
            if type.is_pyobject:
                error(c.pos, "Tuple types can't (yet) contain Python objects.")
                return error_type
            component_types.append(type)
        entry = env.declare_tuple_type(self.pos, component_types)
        entry.used = True
        return entry.type


class FusedTypeNode(CBaseTypeNode):
    """
    Represents a fused type in a ctypedef statement:

        ctypedef cython.fused_type(int, long, long long) integral

    name            str                     name of this fused type
    types           [CSimpleBaseTypeNode]   is the list of types to be fused
    """

    child_attrs = []

    def analyse_declarations(self, env):
        type = self.analyse(env)
        entry = env.declare_typedef(self.name, type, self.pos)

        # Omit the typedef declaration that self.declarator would produce
        entry.in_cinclude = True

    def analyse(self, env, could_be_name=False):
        types = []
        for type_node in self.types:
            type = type_node.analyse_as_type(env)

            if not type:
                error(type_node.pos, "Not a type")
                continue

            if type in types:
                error(type_node.pos, "Type specified multiple times")
            else:
                types.append(type)

        # if len(self.types) == 1:
        #     return types[0]

        return PyrexTypes.FusedType(types, name=self.name)


class CConstOrVolatileTypeNode(CBaseTypeNode):
    # base_type     CBaseTypeNode
    # is_const      boolean
    # is_volatile   boolean

    child_attrs = ["base_type"]

    def analyse(self, env, could_be_name=False):
        base = self.base_type.analyse(env, could_be_name)
        if base.is_pyobject:
            error(self.pos,
                  "Const/volatile base type cannot be a Python object")
        return PyrexTypes.c_const_or_volatile_type(base, self.is_const, self.is_volatile)


class CVarDefNode(StatNode):
    #  C variable definition or forward/extern function declaration.
    #
    #  visibility    'private' or 'public' or 'extern'
    #  base_type     CBaseTypeNode
    #  declarators   [CDeclaratorNode]
    #  in_pxd        boolean
    #  api           boolean
    #  overridable   boolean        whether it is a cpdef
    #  modifiers     ['inline']

    #  decorators    [cython.locals(...)] or None
    #  directive_locals { string : NameNode } locals defined by cython.locals(...)

    child_attrs = ["base_type", "declarators"]

    decorators = None
    directive_locals = None

    def analyse_declarations(self, env, dest_scope=None):
        if self.directive_locals is None:
            self.directive_locals = {}
        if not dest_scope:
            dest_scope = env
        self.dest_scope = dest_scope

        if self.declarators:
            templates = self.declarators[0].analyse_templates()
        else:
            templates = None
        if templates is not None:
            if self.visibility != 'extern':
                error(self.pos, "Only extern functions allowed")
            if len(self.declarators) > 1:
                error(self.declarators[1].pos, "Can't multiply declare template types")
            env = TemplateScope('func_template', env)
            env.directives = env.outer_scope.directives
            for template_param in templates:
                env.declare_type(template_param.name, template_param, self.pos)

        base_type = self.base_type.analyse(env)

        # Check for declaration modifiers, e.g. "typing.Optional[...]" or "dataclasses.InitVar[...]"
        modifiers = None
        if self.base_type.is_templated_type_node:
            modifiers = self.base_type.analyse_pytyping_modifiers(env)

        if base_type.is_fused and not self.in_pxd and (env.is_c_class_scope or
                                                       env.is_module_scope):
            error(self.pos, "Fused types not allowed here")
            return error_type

        self.entry = None
        visibility = self.visibility

        for declarator in self.declarators:

            if (len(self.declarators) > 1
                    and not isinstance(declarator, CNameDeclaratorNode)
                    and env.directives['warn.multiple_declarators']):
                warning(
                    declarator.pos,
                    "Non-trivial type declarators in shared declaration (e.g. mix of pointers and values). "
                    "Each pointer declaration should be on its own line.", 1)

            create_extern_wrapper = (self.overridable
                                     and self.visibility == 'extern'
                                     and env.is_module_scope)
            if create_extern_wrapper:
                declarator.overridable = False
            if isinstance(declarator, CFuncDeclaratorNode):
                name_declarator, type = declarator.analyse(
                    base_type, env, directive_locals=self.directive_locals, visibility=visibility, in_pxd=self.in_pxd)
            else:
                name_declarator, type = declarator.analyse(
                    base_type, env, visibility=visibility, in_pxd=self.in_pxd)
            if not type.is_complete():
                if not (self.visibility == 'extern' and type.is_array or type.is_memoryviewslice):
                    error(declarator.pos, "Variable type '%s' is incomplete" % type)
            if self.visibility == 'extern' and type.is_pyobject:
                error(declarator.pos, "Python object cannot be declared extern")
            name = name_declarator.name
            cname = name_declarator.cname
            if name == '':
                error(declarator.pos, "Missing name in declaration.")
                return
            if type.is_reference and self.visibility != 'extern':
                error(declarator.pos, "C++ references cannot be declared; use a pointer instead")
            if type.is_rvalue_reference and self.visibility != 'extern':
                error(declarator.pos, "C++ rvalue-references cannot be declared")
            if type.is_cfunction:
                if 'staticmethod' in env.directives:
                    type.is_static_method = True
                self.entry = dest_scope.declare_cfunction(
                    name, type, declarator.pos,
                    cname=cname, visibility=self.visibility, in_pxd=self.in_pxd,
                    api=self.api, modifiers=self.modifiers, overridable=self.overridable)
                if self.entry is not None:
                    self.entry.directive_locals = copy.copy(self.directive_locals)
                if create_extern_wrapper:
                    self.entry.type.create_to_py_utility_code(env)
                    self.entry.create_wrapper = True
            else:
                if self.overridable:
                    error(self.pos, "Variables cannot be declared with 'cpdef'. Use 'cdef' instead.")
                if self.directive_locals:
                    error(self.pos, "Decorators can only be followed by functions")
                self.entry = dest_scope.declare_var(
                    name, type, declarator.pos,
                    cname=cname, visibility=visibility, in_pxd=self.in_pxd,
                    api=self.api, is_cdef=True, pytyping_modifiers=modifiers)
                if Options.docstrings:
                    self.entry.doc = embed_position(self.pos, self.doc)


class CStructOrUnionDefNode(StatNode):
    #  name          string
    #  cname         string or None
    #  kind          "struct" or "union"
    #  typedef_flag  boolean
    #  visibility    "public" or "private"
    #  api           boolean
    #  in_pxd        boolean
    #  attributes    [CVarDefNode] or None
    #  entry         Entry
    #  packed        boolean

    child_attrs = ["attributes"]

    def declare(self, env, scope=None):
        self.entry = env.declare_struct_or_union(
            self.name, self.kind, scope, self.typedef_flag, self.pos,
            self.cname, visibility=self.visibility, api=self.api,
            packed=self.packed)

    def analyse_declarations(self, env):
        scope = None
        if self.attributes is not None:
            scope = StructOrUnionScope(self.name)
        self.declare(env, scope)
        if self.attributes is not None:
            if self.in_pxd and not env.in_cinclude:
                self.entry.defined_in_pxd = 1
            for attr in self.attributes:
                attr.analyse_declarations(env, scope)
            if self.visibility != 'extern':
                for attr in scope.var_entries:
                    type = attr.type
                    while type.is_array:
                        type = type.base_type
                    if type == self.entry.type:
                        error(attr.pos, "Struct cannot contain itself as a member.")

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        pass


class CppClassNode(CStructOrUnionDefNode, BlockNode):

    #  name          string
    #  cname         string or None
    #  visibility    "extern"
    #  in_pxd        boolean
    #  attributes    [CVarDefNode] or None
    #  entry         Entry
    #  base_classes  [CBaseTypeNode]
    #  templates     [(string, bool)] or None
    #  decorators    [DecoratorNode] or None

    decorators = None

    def declare(self, env):
        if self.templates is None:
            template_types = None
        else:
            template_types = [PyrexTypes.TemplatePlaceholderType(template_name, not required)
                              for template_name, required in self.templates]
            num_optional_templates = sum(not required for _, required in self.templates)
            if num_optional_templates and not all(required for _, required in self.templates[:-num_optional_templates]):
                error(self.pos, "Required template parameters must precede optional template parameters.")
        self.entry = env.declare_cpp_class(
            self.name, None, self.pos, self.cname,
            base_classes=[], visibility=self.visibility, templates=template_types)

    def analyse_declarations(self, env):
        if not env.is_cpp():
            warning(self.pos,
                    "Using 'cppclass' while Cython is not in c++ mode",
                    level=1)
        if self.templates is None:
            template_types = template_names = None
        else:
            template_names = [template_name for template_name, _ in self.templates]
            template_types = [PyrexTypes.TemplatePlaceholderType(template_name, not required)
                              for template_name, required in self.templates]
        scope = None
        if self.attributes is not None:
            scope = CppClassScope(self.name, env, templates=template_names)
        def base_ok(base_class):
            if base_class.is_cpp_class or base_class.is_struct:
                return True
            else:
                error(self.pos, "Base class '%s' not a struct or class." % base_class)
        base_class_types = filter(base_ok, [b.analyse(scope or env) for b in self.base_classes])
        self.entry = env.declare_cpp_class(
            self.name, scope, self.pos,
            self.cname, base_class_types, visibility=self.visibility, templates=template_types)
        if self.entry is None:
            return
        self.entry.is_cpp_class = 1
        if scope is not None:
            scope.type = self.entry.type
        defined_funcs = []
        def func_attributes(attributes):
            for attr in attributes:
                if isinstance(attr, CFuncDefNode):
                    yield attr
                elif isinstance(attr, CompilerDirectivesNode):
                    yield from func_attributes(attr.body.stats)
                elif isinstance(attr, CppClassNode) and attr.attributes is not None:
                    yield from func_attributes(attr.attributes)
        if self.attributes is not None:
            if self.in_pxd and not env.in_cinclude:
                self.entry.defined_in_pxd = 1
            for attr in self.attributes:
                declare = getattr(attr, 'declare', None)
                if declare:
                    attr.declare(scope)
                attr.analyse_declarations(scope)
            for func in func_attributes(self.attributes):
                defined_funcs.append(func)
                if self.templates is not None:
                    func.template_declaration = "template <typename %s>" % ", typename ".join(template_names)
        self.body = StatListNode(self.pos, stats=defined_funcs)
        self.scope = scope

    def analyse_expressions(self, env):
        self.body = self.body.analyse_expressions(self.entry.type.scope)
        return self

    def generate_function_definitions(self, env, code):
        self.body.generate_function_definitions(self.entry.type.scope, code)

    def generate_execution_code(self, code):
        self.body.generate_execution_code(code)

    def annotate(self, code):
        self.body.annotate(code)


class CEnumDefNode(StatNode):
    #  name               string or None
    #  cname              string or None
    #  scoped             boolean                Is a C++ scoped enum
    #  underlying_type    CSimpleBaseTypeNode    The underlying value type (int or C++ type)
    #  items              [CEnumDefItemNode]
    #  typedef_flag       boolean
    #  visibility         "public" or "private" or "extern"
    #  api                boolean
    #  in_pxd             boolean
    #  create_wrapper     boolean
    #  entry              Entry
    #  doc                EncodedString or None    Doc string

    child_attrs = ["items", "underlying_type"]
    doc = None

    def declare(self, env):
        doc = None
        if Options.docstrings:
            doc = embed_position(self.pos, self.doc)

        self.entry = env.declare_enum(
            self.name, self.pos,
            cname=self.cname,
            scoped=self.scoped,
            typedef_flag=self.typedef_flag,
            visibility=self.visibility, api=self.api,
            create_wrapper=self.create_wrapper, doc=doc)

    def analyse_declarations(self, env):
        scope = None
        underlying_type = self.underlying_type.analyse(env)

        if not underlying_type.is_int:
            error(self.underlying_type.pos, "underlying type is not an integral type")

        self.entry.type.underlying_type = underlying_type

        if self.scoped and self.items is not None:
            scope = CppScopedEnumScope(self.name, env)
            scope.type = self.entry.type
            scope.directives = env.directives
        else:
            scope = env

        if self.items is not None:
            if self.in_pxd and not env.in_cinclude:
                self.entry.defined_in_pxd = 1

            # For extern enums, we can't reason about their equivalent int values because
            # we don't know if their definition is complete.
            is_declared_enum = self.visibility != 'extern'

            next_int_enum_value = 0 if is_declared_enum else None
            for item in self.items:
                item.analyse_enum_declarations(scope, self.entry, next_int_enum_value)
                if is_declared_enum:
                    next_int_enum_value = 1 + (
                        item.entry.enum_int_value if item.entry.enum_int_value is not None else next_int_enum_value)

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        if self.scoped:
            # Nothing to do here for C++ enums.
            return
        if not self.api and not (self.name or self.visibility == 'public'):
            # API enums need to be globally importable and we (currently) do that through global item names.
            # Named enums are namespaced and need no additional global setup.
            return

        # Copy the values of anonymous cpdef/api enums into the global Python module namespace.
        code.mark_pos(self.pos)
        temp = code.funcstate.allocate_temp(PyrexTypes.py_object_type, manage_ref=True)
        for item in self.entry.enum_values:
            code.putln("%s = PyLong_FromLong(%s); %s" % (
                temp,
                item.cname,
                code.error_goto_if_null(temp, item.pos)))
            code.put_gotref(temp, PyrexTypes.py_object_type)
            code.putln('if (PyDict_SetItemString(%s, %s, %s) < 0) %s' % (
                code.name_in_module_state(Naming.moddict_cname),
                item.name.as_c_string_literal(),
                temp,
                code.error_goto(item.pos)))
            code.put_decref_clear(temp, PyrexTypes.py_object_type)
        code.funcstate.release_temp(temp)


class CEnumDefItemNode(StatNode):
    #  name     string
    #  cname    string or None
    #  value    ExprNode or None

    child_attrs = ["value"]

    def analyse_enum_declarations(self, env, enum_entry, incremental_int_value):
        if self.value:
            self.value = self.value.analyse_const_expression(env)
            if not self.value.type.is_int:
                self.value = self.value.coerce_to(PyrexTypes.c_int_type, env)
                self.value = self.value.analyse_const_expression(env)

        if enum_entry.type.is_cpp_enum:
            cname = "%s::%s" % (enum_entry.cname, self.name)
        else:
            cname = self.cname

        self.entry = entry = env.declare_const(
            self.name, enum_entry.type,
            self.value, self.pos, cname=cname,
            visibility=enum_entry.visibility, api=enum_entry.api,
            create_wrapper=enum_entry.create_wrapper and enum_entry.name is None)

        # Use the incremental integer value unless we see an explicitly declared value.
        enum_value = incremental_int_value
        if self.value:
            if self.value.is_literal:
                enum_value = str_to_number(self.value.value)
            elif (self.value.is_name or self.value.is_attribute) and self.value.entry:
                enum_value = self.value.entry.enum_int_value
            else:
                # There is a value but we don't understand its integer value.
                enum_value = None
        if enum_value is not None:
            entry.enum_int_value = enum_value

        enum_entry.enum_values.append(entry)
        if enum_entry.name:
            enum_entry.type.values.append(entry.name)


class CTypeDefNode(StatNode):
    #  base_type    CBaseTypeNode
    #  declarator   CDeclaratorNode
    #  visibility   "public" or "private"
    #  api          boolean
    #  in_pxd       boolean

    child_attrs = ["base_type", "declarator"]

    def analyse_declarations(self, env):
        base = self.base_type.analyse(env)
        name_declarator, type = self.declarator.analyse(
            base, env, visibility=self.visibility, in_pxd=self.in_pxd)
        name = name_declarator.name
        cname = name_declarator.cname

        entry = env.declare_typedef(
            name, type, self.pos,
            cname=cname, visibility=self.visibility, api=self.api)

        if type.is_fused:
            entry.in_cinclude = True

        if self.in_pxd and not env.in_cinclude:
            entry.defined_in_pxd = 1

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        pass


class FuncDefNode(StatNode, BlockNode):
    #  Base class for function definition nodes.
    #
    #  return_type     PyrexType
    #  #filename        string        C name of filename string const
    #  entry           Symtab.Entry
    #  needs_closure   boolean        Whether or not this function has inner functions/classes/yield
    #  needs_outer_scope boolean      Whether or not this function requires outer scope
    #  pymethdef_required boolean     Force Python method struct generation
    #  directive_locals { string : ExprNode } locals defined by cython.locals(...)
    #  directive_returns [ExprNode] type defined by cython.returns(...)
    #  star_arg      PyArgDeclNode or None  * argument
    #  starstar_arg  PyArgDeclNode or None  ** argument
    #
    #  is_async_def  boolean          is a Coroutine function
    #
    #  has_fused_arguments  boolean
    #       Whether this cdef function has fused parameters. This is needed
    #       by AnalyseDeclarationsTransform, so it can replace CFuncDefNodes
    #       with fused argument types with a FusedCFuncDefNode

    py_func = None
    needs_closure = False
    needs_outer_scope = False
    pymethdef_required = False
    is_generator = False
    is_generator_expression = False  # this can be True alongside is_generator
    is_coroutine = False
    is_asyncgen = False
    is_generator_body = False
    is_async_def = False
    modifiers = []
    has_fused_arguments = False
    star_arg = None
    starstar_arg = None
    is_cyfunction = False
    code_object = None
    return_type_annotation = None

    outer_attrs = None  # overridden by some derived classes - to be visited outside the node's scope

    def analyse_default_values(self, env):
        default_seen = 0
        for arg in self.args:
            if arg.default:
                default_seen = 1
                if arg.is_generic:
                    arg.default = arg.default.analyse_types(env)
                    arg.default = arg.default.coerce_to(arg.type, env)
                elif arg.is_special_method_optional:
                    if not arg.default.is_none:
                        error(arg.pos, "This argument cannot have a non-None default value")
                        arg.default = None
                else:
                    error(arg.pos, "This argument cannot have a default value")
                    arg.default = None
            elif arg.kw_only:
                default_seen = 1
            elif default_seen:
                error(arg.pos, "Non-default argument following default argument")

    def analyse_annotations(self, env):
        for arg in self.args:
            if arg.annotation:
                arg.annotation = arg.annotation.analyse_types(env)
        if self.return_type_annotation:
            self.return_type_annotation = self.return_type_annotation.analyse_types(env)

    def align_argument_type(self, env, arg):
        # @cython.locals()
        directive_locals = self.directive_locals
        orig_type = arg.type
        if arg.name in directive_locals:
            type_node = directive_locals[arg.name]
            other_type = type_node.analyse_as_type(env)
        elif isinstance(arg, CArgDeclNode) and arg.annotation and env.directives['annotation_typing']:
            type_node = arg.annotation
            other_type = arg.inject_type_from_annotations(env)
            if other_type is None:
                return arg
        else:
            return arg
        if other_type is None:
            error(type_node.pos, "Not a type")
        elif orig_type is not py_object_type and not orig_type.same_as(other_type):
            error(arg.base_type.pos, "Signature does not agree with previous declaration")
            error(type_node.pos, "Previous declaration here")
        else:
            arg.type = other_type
            if arg.type.is_complex:
                # utility code for complex types is special-cased and also important to ensure that it's run
                arg.type.create_declaration_utility_code(env)
        return arg

    def need_gil_acquisition(self, lenv):
        return 0

    def create_local_scope(self, env):
        genv = env
        while genv.is_py_class_scope or genv.is_c_class_scope:
            genv = genv.outer_scope
        if self.needs_closure:
            cls = GeneratorExpressionScope if self.is_generator_expression else ClosureScope
            lenv = cls(name=self.entry.name,
                                outer_scope=genv,
                                parent_scope=env,
                                scope_name=self.entry.cname)
            # FIXME: why do GeneratorDefNode and GeneratorBodyDefNode use the same scope?
            # This should hit the GeneratorBodyDefNode, not the GeneratorDefNode.
            if self.is_generator_body or self.is_generator:
                lenv.is_generator_scope = True
        else:
            lenv = LocalScope(name=self.entry.name,
                              outer_scope=genv,
                              parent_scope=env)
        lenv.return_type = self.return_type
        type = self.entry.type
        if type.is_cfunction:
            lenv.nogil = type.nogil and not type.with_gil
        self.local_scope = lenv
        lenv.directives = env.directives
        return lenv

    def generate_function_body(self, env, code):
        self.body.generate_execution_code(code)

    def generate_function_definitions(self, env, code):
        from . import Buffer

        lenv = self.local_scope
        if lenv.is_closure_scope and not lenv.is_passthrough:
            outer_scope_cname = "%s->%s" % (Naming.cur_scope_cname,
                                            Naming.outer_scope_cname)
        else:
            outer_scope_cname = Naming.outer_scope_cname
        lenv.mangle_closure_cnames(outer_scope_cname)
        # Generate closure function definitions
        self.body.generate_function_definitions(lenv, code)
        # generate lambda function definitions
        self.generate_lambda_definitions(lenv, code)

        is_getbuffer_slot = (self.entry.name == "__getbuffer__" and
                             self.entry.scope.is_c_class_scope)
        is_releasebuffer_slot = (self.entry.name == "__releasebuffer__" and
                                 self.entry.scope.is_c_class_scope)
        is_buffer_slot = is_getbuffer_slot or is_releasebuffer_slot
        if is_buffer_slot:
            if 'cython_unused' not in self.modifiers:
                self.modifiers = self.modifiers + ['cython_unused']

        preprocessor_guard = self.get_preprocessor_guard()

        if self.is_generator:
            # generators are traced when iterated, not at creation
            tracing = False
        else:
            tracing = code.is_tracing()
            if tracing:
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached("Profile", "Profile.c"))
                if code.globalstate.directives['linetrace']:
                    code.use_fast_gil_utility_code()

        # Generate C code for header and body of function
        code.enter_cfunc_scope(lenv)
        code.return_from_error_cleanup_label = code.new_label()
        code.funcstate.gil_owned = not lenv.nogil

        # ----- Top-level constants used by this function
        code.mark_pos(self.pos)
        self.generate_cached_builtins_decls(lenv, code)
        # ----- Function header
        code.putln("")

        if preprocessor_guard:
            code.putln(preprocessor_guard)

        with_pymethdef = (self.needs_assignment_synthesis(env, code) or
                          self.pymethdef_required)
        if self.py_func:
            self.py_func.generate_function_header(
                code, with_pymethdef=with_pymethdef, proto_only=True)
        self.generate_function_header(code, with_pymethdef=with_pymethdef)
        # ----- Local variable declarations
        # Find function scope
        cenv = env
        while cenv.is_py_class_scope or cenv.is_c_class_scope:
            cenv = cenv.outer_scope
        if self.needs_closure:
            code.put(lenv.scope_class.type.declaration_code(Naming.cur_scope_cname))
            code.putln(";")
        elif self.needs_outer_scope:
            if lenv.is_passthrough:
                code.put(lenv.scope_class.type.declaration_code(Naming.cur_scope_cname))
                code.putln(";")
            code.put(cenv.scope_class.type.declaration_code(Naming.outer_scope_cname))
            code.putln(";")
        self.generate_argument_declarations(lenv, code)

        for entry in lenv.var_entries:
            if not (entry.in_closure or entry.is_arg):
                code.put_var_declaration(entry)

        # Initialize the return variable __pyx_r
        init = ""
        return_type = self.return_type
        if return_type.is_cv_qualified and return_type.is_const:
            # Within this function body, we want to be able to set this
            # variable, even though the function itself needs to return
            # a const version
            return_type = return_type.cv_base_type
        if not return_type.is_void:
            if return_type.is_pyobject:
                init = " = NULL"
            elif return_type.is_memoryviewslice:
                init = ' = ' + return_type.literal_code(return_type.default_value)

            code.putln("%s%s;" % (
                return_type.declaration_code(Naming.retval_cname),
                init))

        tempvardecl_code = code.insertion_point()
        self.generate_keyword_list(code)

        # ----- GIL acquisition
        acquire_gil = self.acquire_gil

        used_buffer_entries = [entry for entry in lenv.buffer_entries if entry.used]

        # See if we need to acquire the GIL for variable declarations, or for
        # refnanny only
        # Closures are not currently possible for cdef nogil functions,
        # but check them anyway
        var_decls_definitely_need_gil = lenv.nogil and (self.needs_closure or self.needs_outer_scope)

        gilstate_decl = None
        var_decls_need_gil = False
        if acquire_gil or var_decls_definitely_need_gil:
            code.put_ensure_gil()
            code.funcstate.gil_owned = True
            var_decls_need_gil = True
        else:
            gilstate_decl = code.insertion_point()

        if tracing:
            tempvardecl_code.put_trace_declarations()
            code_object = None
            if self.code_object:
                self.code_object.generate_result_code(code)
                code_object = self.code_object.py_result()
            code.put_trace_frame_init(code_object)

        # ----- Special check for getbuffer
        if is_getbuffer_slot:
            self.getbuffer_check(code)

        # ----- set up refnanny
        refnanny_decl_code = tempvardecl_code.insertion_point()
        refnanny_setup_code = code.insertion_point()
        refnanny_needs_gil = not code.funcstate.gil_owned

        # ----- Automatic lead-ins for certain special functions
        if is_getbuffer_slot:
            self.getbuffer_init(code)
        # ----- Create closure scope object
        if self.needs_closure:
            tp_slot = TypeSlots.ConstructorSlot("tp_new", '__new__')
            slot_func_cname = TypeSlots.get_slot_function(lenv.scope_class.type.scope, tp_slot)
            if not slot_func_cname:
                slot_func_cname = '%s->tp_new' % (
                    code.name_in_module_state(lenv.scope_class.type.typeptr_cname))
            code.putln("%s = (%s)%s(%s, %s, NULL);" % (
                Naming.cur_scope_cname,
                lenv.scope_class.type.empty_declaration_code(),
                slot_func_cname,
                code.name_in_module_state(lenv.scope_class.type.typeptr_cname),
                code.name_in_module_state(Naming.empty_tuple)))
            code.putln("if (unlikely(!%s)) {" % Naming.cur_scope_cname)
            # Scope unconditionally DECREFed on return.
            code.putln("%s = %s;" % (
                Naming.cur_scope_cname,
                lenv.scope_class.type.cast_code("Py_None")))
            code.put_incref("Py_None", py_object_type)
            code.putln(code.error_goto(self.pos))
            code.putln("} else {")
            code.put_gotref(Naming.cur_scope_cname, lenv.scope_class.type)
            code.putln("}")
            # Note that it is unsafe to decref the scope at this point.
        if self.needs_outer_scope:
            if self.is_cyfunction:
                code.putln("%s = (%s) __Pyx_CyFunction_GetClosure(%s);" % (
                    outer_scope_cname,
                    cenv.scope_class.type.empty_declaration_code(),
                    Naming.self_cname))
            else:
                code.putln("%s = (%s) %s;" % (
                    outer_scope_cname,
                    cenv.scope_class.type.empty_declaration_code(),
                    Naming.self_cname))
            if lenv.is_passthrough:
                code.putln("%s = %s;" % (Naming.cur_scope_cname, outer_scope_cname))
            elif self.needs_closure:
                # inner closures own a reference to their outer parent
                code.put_incref(outer_scope_cname, cenv.scope_class.type)
                code.put_giveref(outer_scope_cname, cenv.scope_class.type)
        # ----- Trace function call
        if tracing:
            # this looks a bit late, but if we don't get here due to a
            # fatal error before hand, it's not really worth tracing
            if self.is_wrapper:
                trace_name = EncodedString(self.entry.name + " (wrapper)")
            else:
                trace_name = self.entry.name
            code.put_trace_start(
                trace_name, self.pos, nogil=not code.funcstate.gil_owned, is_cpdef_func=self.py_func is not None)
            code.funcstate.can_trace = True
        # ----- Fetch arguments
        self.generate_argument_parsing_code(env, code)
        # If an argument is assigned to in the body, we must
        # incref it to properly keep track of refcounts.
        for entry in lenv.arg_entries:
            if not entry.type.is_memoryviewslice:
                if (acquire_gil or entry.cf_is_reassigned) and not entry.in_closure:
                    code.put_var_incref(entry)
            # Note: defaults are always incref-ed. For def functions, we
            #       we acquire arguments from object conversion, so we have
            #       new references. If we are a cdef function, we need to
            #       incref our arguments
            elif entry.cf_is_reassigned and not entry.in_closure:
                code.put_var_incref_memoryviewslice(entry,
                                    have_gil=code.funcstate.gil_owned)
        for entry in lenv.var_entries:
            if entry.is_arg and entry.cf_is_reassigned and not entry.in_closure:
                if entry.type.is_memoryviewslice:
                    code.put_var_incref_memoryviewslice(entry,
                                        have_gil=code.funcstate.gil_owned)
                if entry.xdecref_cleanup:
                    code.put_var_xincref(entry)
                else:
                    code.put_var_incref(entry)
            if entry.type.needs_explicit_construction(lenv):
                entry.type.generate_explicit_construction(code, entry)

        # ----- Initialise local buffer auxiliary variables
        for entry in lenv.var_entries + lenv.arg_entries:
            if entry.type.is_buffer and entry.buffer_aux.buflocal_nd_var.used:
                Buffer.put_init_vars(entry, code)

        # ----- Check and convert arguments
        self.generate_argument_type_tests(code)
        # ----- Acquire buffer arguments
        for entry in lenv.arg_entries:
            if entry.type.is_buffer:
                Buffer.put_acquire_arg_buffer(entry, code, self.pos)

        if code.funcstate.needs_refnanny:
            # if this is true there's definite some reference counting in
            # the variable declarations
            var_decls_need_gil = True

        if var_decls_need_gil and lenv.nogil:
            if gilstate_decl is not None:
                gilstate_decl.put_ensure_gil()
                gilstate_decl = None
                code.funcstate.gil_owned = True
            code.put_release_ensured_gil()
            code.funcstate.gil_owned = False

        # -------------------------
        # ----- Function body -----
        # -------------------------
        self.generate_function_body(env, code)

        code.mark_pos(self.pos, trace=False)
        code.putln("")
        code.putln("/* function exit code */")

        gil_owned = {
            'success': code.funcstate.gil_owned,
            'error': code.funcstate.gil_owned,
            'gil_state_declared': gilstate_decl is None,
        }
        def assure_gil(code_path, code=code):
            if not gil_owned[code_path]:
                if not gil_owned['gil_state_declared']:
                    gilstate_decl.declare_gilstate()
                    gil_owned['gil_state_declared'] = True
                code.put_ensure_gil(declare_gilstate=False)
                gil_owned[code_path] = True

        # ----- Default return value
        return_type = self.return_type
        if not self.body.is_terminator:
            if return_type.is_pyobject:
                #if return_type.is_extension_type:
                #    lhs = "(PyObject *)%s" % Naming.retval_cname
                #else:
                lhs = Naming.retval_cname
                assure_gil('success')
                code.put_init_to_py_none(lhs, return_type)
            elif not return_type.is_memoryviewslice:
                # memory view structs receive their default value on initialisation
                val = return_type.default_value
                if val:
                    code.putln("%s = %s;" % (Naming.retval_cname, val))
                elif not return_type.is_void:
                    code.putln("__Pyx_pretend_to_initialize(&%s);" % Naming.retval_cname)

            if tracing:
                code.put_trace_return(
                    Naming.retval_cname, self.pos, return_type=return_type, nogil=not gil_owned['success'])

        # ----- Error cleanup
        if code.label_used(code.error_label):
            if not self.body.is_terminator:
                code.put_goto(code.return_label)
            code.put_label(code.error_label)
            for cname, type in code.funcstate.all_managed_temps():
                assure_gil('error')
                code.put_xdecref(cname, type, have_gil=gil_owned['error'])

            # Clean up buffers -- this calls a Python function
            # so need to save and restore error state
            buffers_present = len(used_buffer_entries) > 0
            #memslice_entries = [e for e in lenv.entries.values() if e.type.is_memoryviewslice]
            if buffers_present:
                code.globalstate.use_utility_code(restore_exception_utility_code)
                code.putln("{ PyObject *__pyx_type, *__pyx_value, *__pyx_tb;")
                code.putln("__Pyx_PyThreadState_declare")
                assure_gil('error')
                code.putln("__Pyx_PyThreadState_assign")
                code.putln("__Pyx_ErrFetch(&__pyx_type, &__pyx_value, &__pyx_tb);")
                for entry in used_buffer_entries:
                    Buffer.put_release_buffer_code(code, entry)
                    #code.putln("%s = 0;" % entry.cname)
                code.putln("__Pyx_ErrRestore(__pyx_type, __pyx_value, __pyx_tb);}")

            if return_type.is_memoryviewslice:
                from . import MemoryView
                MemoryView.put_init_entry(Naming.retval_cname, code)
                err_val = Naming.retval_cname
            else:
                err_val = self.error_value()

            if tracing:
                assure_gil('error')
                code.put_trace_exception_propagating()
                code.putln("#if CYTHON_USE_SYS_MONITORING")
                code.put_trace_unwind(self.pos)
                code.putln("#else")
                code.put_trace_return("NULL", self.pos, nogil=not gil_owned['success'])
                code.putln("#endif")

            exc_check = self.caller_will_check_exceptions()
            if err_val is not None or exc_check:
                assure_gil('error')
                if code.funcstate.error_without_exception:
                    tempvardecl_code.putln(
                        "int %s = 0; /* StopIteration */" % Naming.error_without_exception_cname
                    )
                    code.putln("if (!%s) {" % Naming.error_without_exception_cname)
                code.put_add_traceback(self.entry.qualified_name)
                if code.funcstate.error_without_exception:
                    code.putln("}")
            else:
                warning(self.entry.pos,
                        "Unraisable exception in function '%s'." %
                        self.entry.qualified_name, 0)
                assure_gil('error')
                code.put_unraisable(self.entry.qualified_name)
            default_retval = return_type.default_value
            if err_val is None and default_retval:
                err_val = default_retval
            if err_val is not None:
                if err_val != Naming.retval_cname:
                    code.putln("%s = %s;" % (Naming.retval_cname, err_val))
            elif not return_type.is_void:
                code.putln("__Pyx_pretend_to_initialize(&%s);" % Naming.retval_cname)

            if is_getbuffer_slot:
                assure_gil('error')
                self.getbuffer_error_cleanup(code)

            def align_error_path_gil_to_success_path(code=code.insertion_point()):
                # align error and success GIL state when both join
                if gil_owned['success']:
                    assure_gil('error', code=code)
                elif gil_owned['error']:
                    code.put_release_ensured_gil()
                    gil_owned['error'] = False
                assert gil_owned['error'] == gil_owned['success'], "%s: error path %s != success path %s" % (
                    self.pos, gil_owned['error'], gil_owned['success'])

            # If we are using the non-error cleanup section we should
            # jump past it if we have an error. The if-test below determine
            # whether this section is used.
            if buffers_present or is_getbuffer_slot or return_type.is_memoryviewslice:
                # In the buffer cases, we already called assure_gil('error') and own the GIL.
                assert gil_owned['error'] or return_type.is_memoryviewslice
                code.put_goto(code.return_from_error_cleanup_label)
            else:
                # Adapt the GIL state to the success path right now.
                align_error_path_gil_to_success_path()
        else:
            # No error path, no need to adapt the GIL state.
            def align_error_path_gil_to_success_path(): pass

        # ----- Non-error return cleanup
        if code.label_used(code.return_label) or not code.label_used(code.error_label):
            code.put_label(code.return_label)

            for entry in used_buffer_entries:
                assure_gil('success')
                Buffer.put_release_buffer_code(code, entry)
            if is_getbuffer_slot:
                assure_gil('success')
                self.getbuffer_normal_cleanup(code)

            if return_type.is_memoryviewslice:
                # See if our return value is uninitialized on non-error return
                # from . import MemoryView
                # MemoryView.err_if_nogil_initialized_check(self.pos, env)
                cond = code.unlikely(return_type.error_condition(Naming.retval_cname))
                code.putln(
                    'if (%s) {' % cond)
                if not gil_owned['success']:
                    code.put_ensure_gil()
                code.putln(
                    'PyErr_SetString(PyExc_TypeError, "Memoryview return value is not initialized");')
                if not gil_owned['success']:
                    code.put_release_ensured_gil()
                code.putln(
                    '}')

        # ----- Return cleanup for both error and no-error return
        if code.label_used(code.return_from_error_cleanup_label):
            align_error_path_gil_to_success_path()
            code.put_label(code.return_from_error_cleanup_label)

        for entry in lenv.var_entries:
            if not entry.used or entry.in_closure:
                continue

            if entry.type.needs_refcounting:
                if entry.is_arg and not entry.cf_is_reassigned:
                    continue
                if entry.type.refcounting_needs_gil:
                    assure_gil('success')
            elif entry.type.needs_explicit_destruction(lenv):
                entry.type.generate_explicit_destruction(code, entry)
            # FIXME ideally use entry.xdecref_cleanup but this currently isn't reliable
            code.put_var_xdecref(entry, have_gil=gil_owned['success'])

        # Decref any increfed args
        for entry in lenv.arg_entries:
            if entry.in_closure:
                continue
            if entry.type.is_memoryviewslice:
                # decref slices of def functions and acquired slices from cdef
                # functions, but not borrowed slices from cdef functions.
                if not entry.cf_is_reassigned:
                    continue
            else:
                if not acquire_gil and not entry.cf_is_reassigned:
                    continue
                if entry.type.needs_refcounting:
                    assure_gil('success')

            # FIXME use entry.xdecref_cleanup - del arg seems to be the problem
            code.put_var_xdecref(entry, have_gil=gil_owned['success'])
        if self.needs_closure:
            assure_gil('success')
            code.put_decref(Naming.cur_scope_cname, lenv.scope_class.type)

        # ----- Return
        # This code is duplicated in ModuleNode.generate_module_init_func
        if not lenv.nogil:
            default_retval = return_type.default_value
            err_val = self.error_value()
            if err_val is None and default_retval:
                err_val = default_retval  # FIXME: why is err_val not used?
            code.put_xgiveref(Naming.retval_cname, return_type)

        if self.entry.is_special and self.entry.name == "__hash__":
            # Returning -1 for __hash__ is supposed to signal an error
            # We do as Python instances and coerce -1 into -2.
            assure_gil('success')  # in special methods, the GIL is owned anyway
            code.putln("if (unlikely(%s == -1) && !PyErr_Occurred()) %s = -2;" % (
                Naming.retval_cname, Naming.retval_cname))

        if tracing:
            code.funcstate.can_trace = False
            code.put_trace_exit(nogil=not code.funcstate.gil_owned)

        if code.funcstate.needs_refnanny:
            refnanny_decl_code.put_declare_refcount_context()
            refnanny_setup_code.put_setup_refcount_context(self.entry.name, acquire_gil=refnanny_needs_gil)
            code.put_finish_refcount_context(nogil=not gil_owned['success'])

        if acquire_gil or (lenv.nogil and gil_owned['success']):
            # release the GIL (note that with-gil blocks acquire it on exit in their EnsureGILNode)
            code.put_release_ensured_gil()
            code.funcstate.gil_owned = False

        if not return_type.is_void:
            code.putln("return %s;" % Naming.retval_cname)

        code.putln("}")

        if preprocessor_guard:
            code.putln("#endif /*!(%s)*/" % preprocessor_guard)

        # ----- Go back and insert temp variable declarations
        tempvardecl_code.put_temp_declarations(code.funcstate)

        # ----- Python version
        code.exit_cfunc_scope()
        if self.py_func:
            self.py_func.generate_function_definitions(env, code)
        self.generate_wrapper_functions(code)

    def declare_argument(self, env, arg):
        if arg.type.is_void:
            error(arg.pos, "Invalid use of 'void'")
        elif not arg.type.is_complete() and not (arg.type.is_array or arg.type.is_memoryviewslice):
            error(arg.pos, "Argument type '%s' is incomplete" % arg.type)
        entry = env.declare_arg(arg.name, arg.type, arg.pos)
        if arg.annotation:
            entry.annotation = arg.annotation
        return entry

    def generate_arg_type_test(self, arg, code):
        # Generate type test for one argument.
        if arg.type.typeobj_is_available():
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("ArgTypeTest", "FunctionArguments.c"))
            typeptr_cname = code.typeptr_cname_in_module_state(arg.type)
            arg_code = "((PyObject *)%s)" % arg.entry.cname
            exact = 0
            if arg.type.is_builtin_type and arg.type.require_exact:
                # 2 is used to indicate that the type is from the annotation
                # and provide a little extra info on failure.
                exact = 2 if arg.type_from_annotation else 1
            code.putln(
                'if (unlikely(!__Pyx_ArgTypeTest(%s, %s, %d, %s, %s))) %s' % (
                    arg_code,
                    typeptr_cname,
                    arg.accept_none,
                    arg.name_cstring,
                    exact,
                    code.error_goto(arg.pos)))
        else:
            error(arg.pos, "Cannot test type of extern C class without type object name specification")

    def generate_arg_none_check(self, arg, code):
        # Generate None check for one argument.
        if arg.type.is_memoryviewslice:
            cname = "%s.memview" % arg.entry.cname
        else:
            cname = arg.entry.cname

        code.putln('if (unlikely(((PyObject *)%s) == Py_None)) {' % cname)
        code.putln('''PyErr_Format(PyExc_TypeError, "Argument '%%.%ds' must not be None", %s); %s''' % (
            max(200, len(arg.name_cstring)), arg.name_cstring,
            code.error_goto(arg.pos)))
        code.putln('}')

    def generate_wrapper_functions(self, code):
        pass

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        # Evaluate and store argument default values
        # skip this for wrappers since it's done by wrapped function
        if not self.is_wrapper:
            for arg in self.args:
                if not arg.is_dynamic:
                    arg.generate_assignment_code(code)

    #
    # Special code for the __getbuffer__ function
    #
    def _get_py_buffer_info(self):
        py_buffer = self.local_scope.arg_entries[1]
        try:
            # Check builtin definition of struct Py_buffer
            obj_type = py_buffer.type.base_type.scope.entries['obj'].type
        except (AttributeError, KeyError):
            # User code redeclared struct Py_buffer
            obj_type = None
        return py_buffer, obj_type

    # Old Python 3 used to support write-locks on buffer-like objects by
    # calling PyObject_GetBuffer() with a view==NULL parameter. This obscure
    # feature is obsolete, it was almost never used (only one instance in
    # `Modules/posixmodule.c` in Python 3.1) and it is now officially removed
    # (see bpo-14203). We add an extra check here to prevent legacy code from
    # from trying to use the feature and prevent segmentation faults.
    def getbuffer_check(self, code):
        py_buffer, _ = self._get_py_buffer_info()
        view = py_buffer.cname
        code.putln("if (unlikely(%s == NULL)) {" % view)
        code.putln("PyErr_SetString(PyExc_BufferError, "
                   "\"PyObject_GetBuffer: view==NULL argument is obsolete\");")
        code.putln("return -1;")
        code.putln("}")

    def getbuffer_init(self, code):
        py_buffer, obj_type = self._get_py_buffer_info()
        view = py_buffer.cname
        if obj_type and obj_type.is_pyobject:
            code.put_init_to_py_none("%s->obj" % view, obj_type)
            code.put_giveref("%s->obj" % view, obj_type)  # Do not refnanny object within structs
        else:
            code.putln("%s->obj = NULL;" % view)

    def getbuffer_error_cleanup(self, code):
        py_buffer, obj_type = self._get_py_buffer_info()
        view = py_buffer.cname
        if obj_type and obj_type.is_pyobject:
            code.putln("if (%s->obj != NULL) {" % view)
            code.put_gotref("%s->obj" % view, obj_type)
            code.put_decref_clear("%s->obj" % view, obj_type)
            code.putln("}")
        else:
            code.putln("Py_CLEAR(%s->obj);" % view)

    def getbuffer_normal_cleanup(self, code):
        py_buffer, obj_type = self._get_py_buffer_info()
        view = py_buffer.cname
        if obj_type and obj_type.is_pyobject:
            code.putln("if (%s->obj == Py_None) {" % view)
            code.put_gotref("%s->obj" % view, obj_type)
            code.put_decref_clear("%s->obj" % view, obj_type)
            code.putln("}")

    def get_preprocessor_guard(self):
        if not self.entry.is_special:
            return None
        name = self.entry.name
        slot = TypeSlots.get_slot_table(self.local_scope.directives).get_slot_by_method_name(name)
        if not slot:
            return None
        if name == '__long__' and not self.entry.scope.lookup_here('__int__'):
            return None
        if name in ("__getbuffer__", "__releasebuffer__") and self.entry.scope.is_c_class_scope:
            return None
        return slot.preprocessor_guard_code()


class CFuncDefNode(FuncDefNode):
    #  C function definition.
    #
    #  modifiers     ['inline']
    #  visibility    'private' or 'public' or 'extern'
    #  base_type     CBaseTypeNode
    #  declarator    CDeclaratorNode
    #  cfunc_declarator  the CFuncDeclarator of this function
    #                    (this is also available through declarator or a
    #                     base thereof)
    #  body          StatListNode
    #  api           boolean
    #  decorators    [DecoratorNode]        list of decorators
    #
    #  with_gil      boolean    Acquire GIL around body
    #  type          CFuncType
    #  py_func       wrapper for calling from Python
    #  overridable   whether or not this is a cpdef function
    #  inline_in_pxd whether this is an inline function in a pxd file
    #  template_declaration  String or None   Used for c++ class methods
    #  is_const_method whether this is a const method
    #  is_static_method whether this is a static method
    #  is_c_class_method whether this is a cclass method

    child_attrs = ["base_type", "declarator", "body", "decorators", "py_func_stat"]
    outer_attrs = ["decorators", "py_func_stat"]

    inline_in_pxd = False
    decorators = None
    directive_locals = None
    directive_returns = None
    override = None
    template_declaration = None
    is_const_method = False
    py_func_stat = None
    _code_object = None

    def unqualified_name(self):
        return self.entry.name

    def declared_name(self):
        return self.declarator.declared_name()

    @property
    def code_object(self):
        # share the CodeObject with the cpdef wrapper (if available)
        return self.py_func.code_object if self.py_func else self._code_object

    @code_object.setter
    def code_object(self, code_object):
        self._code_object = code_object

    def analyse_declarations(self, env):
        self.c_compile_guard = env.directives['c_compile_guard']
        self.is_c_class_method = env.is_c_class_scope
        if self.directive_locals is None:
            self.directive_locals = {}
        self.directive_locals.update(env.directives.get('locals', {}))
        if self.directive_returns is not None:
            base_type = self.directive_returns.analyse_as_type(env)
            # Annotated return types with wrong type produce warnings instead of errors.
            if base_type is None:
                if self.directive_returns.is_annotation:
                    base_type = self.base_type.analyse(env)
                else:
                    error(self.directive_returns.pos, "Not a type")
                    base_type = PyrexTypes.error_type
        else:
            base_type = self.base_type.analyse(env)
        self.is_static_method = 'staticmethod' in env.directives and not env.lookup_here('staticmethod')
        # The 2 here is because we need both function and argument names.
        if isinstance(self.declarator, CFuncDeclaratorNode):
            name_declarator, typ = self.declarator.analyse(
                base_type, env, nonempty=2 * (self.body is not None),
                directive_locals=self.directive_locals, visibility=self.visibility)
        else:
            name_declarator, typ = self.declarator.analyse(
                base_type, env, nonempty=2 * (self.body is not None), visibility=self.visibility)
        if not typ.is_cfunction:
            error(self.pos, "Suite attached to non-function declaration")
        # Remember the actual type according to the function header
        # written here, because the type in the symbol table entry
        # may be different if we're overriding a C method inherited
        # from the base type of an extension type.
        self.type = typ
        typ.is_overridable = self.overridable
        declarator = self.declarator
        while not hasattr(declarator, 'args'):
            declarator = declarator.base

        self.cfunc_declarator = declarator
        self.args = declarator.args

        opt_arg_count = self.cfunc_declarator.optional_arg_count
        if (self.visibility == 'public' or self.api) and opt_arg_count:
            error(self.cfunc_declarator.pos,
                  "Function with optional arguments may not be declared public or api")

        if typ.exception_check == '+' and self.visibility != 'extern':
            if typ.exception_value is not None and typ.exception_value.is_name:
                # it really is impossible to reason about what the user wants to happens
                # if they've specified a C++ exception translation function. Therefore,
                # raise an error.
                error(self.pos,
                    "Only extern functions can throw C++ exceptions.")
            else:
                warning(self.pos,
                    "Only extern functions can throw C++ exceptions.", 2)

        for formal_arg, type_arg in zip(self.args, typ.args):
            self.align_argument_type(env, type_arg)
            formal_arg.type = type_arg.type
            formal_arg.name = type_arg.name
            formal_arg.cname = type_arg.cname

            self._validate_type_visibility(type_arg.type, type_arg.pos, env)

            if type_arg.type.is_fused:
                self.has_fused_arguments = True

            if type_arg.type.is_buffer and 'inline' in self.modifiers:
                warning(formal_arg.pos, "Buffer unpacking not optimized away.", 1)

            if type_arg.type.is_buffer or type_arg.type.is_pythran_expr:
                if self.type.nogil:
                    error(formal_arg.pos,
                          "Buffer may not be acquired without the GIL. Consider using memoryview slices instead.")
                elif 'inline' in self.modifiers:
                    warning(formal_arg.pos, "Buffer unpacking not optimized away.", 1)

        self._validate_type_visibility(typ.return_type, self.pos, env)

        name = name_declarator.name
        cname = name_declarator.cname

        typ.is_const_method = self.is_const_method
        typ.is_static_method = self.is_static_method

        self.entry = env.declare_cfunction(
            name, typ, self.pos,
            cname=cname, visibility=self.visibility, api=self.api,
            defining=self.body is not None, modifiers=self.modifiers,
            overridable=self.overridable, in_pxd=self.inline_in_pxd)
        self.return_type = typ.return_type

        if self.return_type.is_array and self.visibility != 'extern':
            error(self.pos, "Function cannot return an array")
        if self.return_type.is_cpp_class:
            self.return_type.check_nullary_constructor(self.pos, "used as a return value")

        if self.overridable and not env.is_module_scope and not self.is_static_method:
            if len(self.args) < 1 or not self.args[0].type.is_pyobject:
                # An error will be produced in the cdef function
                self.overridable = False

        self.declare_cpdef_wrapper(env)
        self.create_local_scope(env)

    def declare_cpdef_wrapper(self, env):
        if not self.overridable:
            return
        if self.is_static_method:
            # TODO(robertwb): Finish this up, perhaps via more function refactoring.
            error(self.pos, "static cpdef methods not yet supported")

        py_func_body = self.call_self_node(is_module_scope=env.is_module_scope)
        py_func_body = CompilerDirectivesNode.for_directives(
            py_func_body, env, profile=False, linetrace=False)

        if self.is_static_method:
            from .ExprNodes import NameNode
            decorators = [DecoratorNode(self.pos, decorator=NameNode(self.pos, name=EncodedString('staticmethod')))]
            decorators[0].decorator.analyse_types(env)
        else:
            decorators = []

        name = self.entry.name
        self.py_func = DefNode(pos=self.pos,
                               name=self.entry.name,
                               args=self.args,
                               star_arg=None,
                               starstar_arg=None,
                               doc=self.doc,
                               body=StatListNode(self.pos, stats=[py_func_body]),
                               decorators=decorators,
                               is_wrapper=1)
        self.py_func.is_module_scope = env.is_module_scope
        self.py_func.analyse_declarations(env)
        self.py_func.entry.is_overridable = True
        self.py_func_stat = StatListNode(self.pos, stats=[self.py_func])
        self.py_func.type = PyrexTypes.py_object_type
        self.entry.as_variable = self.py_func.entry
        self.entry.used = self.entry.as_variable.used = True
        # Reset scope entry the above cfunction
        env.entries[name] = self.entry
        if (not self.entry.is_final_cmethod and
                (not env.is_module_scope or Options.lookup_module_cpdef)):
            if self.override:
                # This is a hack: we shouldn't create the wrapper twice, but we do for fused functions.
                assert self.entry.is_fused_specialized  # should not happen for non-fused cpdef functions
                self.override.py_func = self.py_func
            else:
                self.override = OverrideCheckNode(self.pos, py_func=self.py_func)
                self.body = StatListNode(self.pos, stats=[self.override, self.body])

    def _validate_type_visibility(self, type, pos, env):
        """
        Ensure that types used in cdef functions are public or api, or
        defined in a C header.
        """
        public_or_api = (self.visibility == 'public' or self.api)
        entry = getattr(type, 'entry', None)
        if public_or_api and entry and env.is_module_scope:
            if not (entry.visibility in ('public', 'extern') or
                    entry.api or entry.in_cinclude):
                error(pos, "Function declared public or api may not have private types")

    def call_self_node(self, omit_optional_args=0, is_module_scope=0):
        from . import ExprNodes
        args = self.type.args
        if omit_optional_args:
            args = args[:len(args) - self.type.optional_arg_count]
        arg_names = [arg.name for arg in args]
        if is_module_scope:
            cfunc = ExprNodes.NameNode(self.pos, name=self.entry.name)
            call_arg_names = arg_names
        elif self.type.is_static_method:
            class_entry = self.entry.scope.parent_type.entry
            class_node = ExprNodes.NameNode(self.pos, name=class_entry.name)
            class_node.entry = class_entry
            cfunc = ExprNodes.AttributeNode(self.pos, obj=class_node, attribute=self.entry.name)
        else:
            type_entry = self.type.args[0].type.entry
            type_arg = ExprNodes.NameNode(self.pos, name=type_entry.name)
            type_arg.entry = type_entry
            cfunc = ExprNodes.AttributeNode(self.pos, obj=type_arg, attribute=self.entry.name)

        skip_dispatch = not (is_module_scope and Options.lookup_module_cpdef)
        c_call = ExprNodes.SimpleCallNode(
            self.pos,
            function=cfunc,
            args=[ExprNodes.NameNode(self.pos, name=n) for n in arg_names],
            wrapper_call=skip_dispatch)
        return ReturnStatNode(pos=self.pos, return_type=PyrexTypes.py_object_type, value=c_call)

    def declare_arguments(self, env):
        for arg in self.type.args:
            if not arg.name:
                error(arg.pos, "Missing argument name")
            self.declare_argument(env, arg)

    def need_gil_acquisition(self, lenv):
        return self.type.with_gil

    def nogil_check(self, env):
        type = self.type
        with_gil = type.with_gil
        if type.nogil and not with_gil:
            if type.return_type.is_pyobject:
                error(self.pos,
                      "Function with Python return type cannot be declared nogil")
            for entry in self.local_scope.var_entries:
                if entry.type.is_pyobject and not entry.in_with_gil_block:
                    error(self.pos, "Function declared nogil has Python locals or temporaries")

    def analyse_expressions(self, env):
        self.local_scope.directives = env.directives
        if self.py_func_stat is not None:
            # this will also analyse the default values and the function name assignment
            self.py_func_stat = self.py_func_stat.analyse_expressions(env)
        elif self.py_func is not None:
            # this will also analyse the default values
            self.py_func = self.py_func.analyse_expressions(env)
        else:
            self.analyse_default_values(env)
            self.analyse_annotations(env)
        self.acquire_gil = self.need_gil_acquisition(self.local_scope)
        return self

    def needs_assignment_synthesis(self, env, code=None):
        return False

    def generate_function_header(self, code, with_pymethdef, with_opt_args=1, with_dispatch=1, cname=None):
        scope = self.local_scope
        arg_decls = []
        type = self.type
        for arg in type.args[:len(type.args)-type.optional_arg_count]:
            arg_decl = arg.declaration_code()
            entry = scope.lookup(arg.name)
            if not entry.cf_used:
                arg_decl = 'CYTHON_UNUSED %s' % arg_decl
            arg_decls.append(arg_decl)
        if with_dispatch and self.overridable:
            dispatch_arg = PyrexTypes.c_int_type.declaration_code(
                Naming.skip_dispatch_cname)
            if self.override:
                arg_decls.append(dispatch_arg)
            else:
                arg_decls.append('CYTHON_UNUSED %s' % dispatch_arg)
        if type.optional_arg_count and with_opt_args:
            arg_decls.append(type.op_arg_struct.declaration_code(Naming.optional_args_cname))
        if type.has_varargs:
            arg_decls.append("...")
        if not arg_decls:
            arg_decls = ["void"]
        if cname is None:
            cname = self.entry.func_cname
        entity = type.function_header_code(cname, ', '.join(arg_decls))
        if self.entry.visibility == 'private' and '::' not in cname:
            storage_class = "static "
        else:
            storage_class = ""
        dll_linkage = None
        modifiers = code.build_function_modifiers(self.entry.func_modifiers)

        header = self.return_type.declaration_code(entity, dll_linkage=dll_linkage)
        #print (storage_class, modifiers, header)
        needs_proto = self.is_c_class_method or self.entry.is_cproperty
        if self.template_declaration:
            if needs_proto:
                code.globalstate.parts['module_declarations'].putln(self.template_declaration)
            code.putln(self.template_declaration)
        if needs_proto:
            preprocessor_guard = self.get_preprocessor_guard()
            if preprocessor_guard:
                code.globalstate.parts['module_declarations'].putln(preprocessor_guard)
            code.globalstate.parts['module_declarations'].putln(
                "%s%s%s; /* proto*/" % (storage_class, modifiers, header))
            if preprocessor_guard:
                code.globalstate.parts['module_declarations'].putln("#endif")
        code.putln("%s%s%s {" % (storage_class, modifiers, header))
        code.globalstate.use_entry_utility_code(self.entry)

    def generate_argument_declarations(self, env, code):
        scope = self.local_scope
        for arg in self.args:
            if arg.default:
                entry = scope.lookup(arg.name)
                if self.override or entry.cf_used:
                    result = arg.calculate_default_value_code(code)
                    code.putln('%s = %s;' % (
                        arg.type.declaration_code(arg.cname), result))

    def generate_keyword_list(self, code):
        pass

    def generate_argument_parsing_code(self, env, code):
        i = 0
        used = 0
        scope = self.local_scope
        if self.type.optional_arg_count:
            code.putln('if (%s) {' % Naming.optional_args_cname)
            for arg in self.args:
                if arg.default:
                    entry = scope.lookup(arg.name)
                    if self.override or entry.cf_used:
                        code.putln('if (%s->%sn > %s) {' %
                                   (Naming.optional_args_cname,
                                    Naming.pyrex_prefix, i))
                        declarator = arg.declarator
                        while not hasattr(declarator, 'name'):
                            declarator = declarator.base
                        code.putln('%s = %s->%s;' %
                                   (arg.cname, Naming.optional_args_cname,
                                    self.type.opt_arg_cname(declarator.name)))
                        used += 1
                    i += 1
            for _ in range(used):
                code.putln('}')
            code.putln('}')

        # Move arguments into closure if required
        def put_into_closure(entry):
            if entry.in_closure and not arg.default:
                code.putln('%s = %s;' % (entry.cname, entry.original_cname))
                if entry.type.is_memoryviewslice:
                    entry.type.generate_incref_memoryviewslice(code, entry.cname, True)
                else:
                    code.put_var_incref(entry)
                    code.put_var_giveref(entry)
        for arg in self.args:
            put_into_closure(scope.lookup_here(arg.name))


    def generate_argument_conversion_code(self, code):
        pass

    def generate_argument_type_tests(self, code):
        # Generate type tests for args whose type in a parent
        # class is a supertype of the declared type.
        for arg in self.type.args:
            if arg.needs_type_test:
                self.generate_arg_type_test(arg, code)
            elif arg.type.is_pyobject and not arg.accept_none:
                self.generate_arg_none_check(arg, code)

    def generate_execution_code(self, code):
        if code.globalstate.directives['linetrace']:
            code.mark_pos(self.pos)
            code.putln("")  # generate line tracing code
        super().generate_execution_code(code)
        if self.py_func_stat:
            self.py_func_stat.generate_execution_code(code)

    def error_value(self):
        if self.return_type.is_pyobject:
            return "0"
        else:
            return self.entry.type.exception_value

    def caller_will_check_exceptions(self):
        return self.entry.type.exception_check

    def generate_wrapper_functions(self, code):
        # If the C signature of a function has changed, we need to generate
        # wrappers to put in the slots here.
        k = 0
        entry = self.entry
        func_type = entry.type
        while entry.prev_entry is not None:
            k += 1
            entry = entry.prev_entry
            entry.func_cname = "%s%swrap_%s" % (self.entry.func_cname, Naming.pyrex_prefix, k)
            code.putln()
            self.generate_function_header(
                code, 0,
                with_dispatch=entry.type.is_overridable,
                with_opt_args=entry.type.optional_arg_count,
                cname=entry.func_cname)
            if not self.return_type.is_void:
                code.put('return ')
            args = self.type.args
            arglist = [arg.cname for arg in args[:len(args)-self.type.optional_arg_count]]
            if entry.type.is_overridable:
                arglist.append(Naming.skip_dispatch_cname)
            elif func_type.is_overridable:
                arglist.append('0')
            if entry.type.optional_arg_count:
                arglist.append(Naming.optional_args_cname)
            elif func_type.optional_arg_count:
                arglist.append('NULL')
            code.putln('%s(%s);' % (self.entry.func_cname, ', '.join(arglist)))
            code.putln('}')

    def get_preprocessor_guard(self):
        super_guard = super().get_preprocessor_guard()
        if self.c_compile_guard:
            assert not super_guard  # Don't currently know how to combine
            return f"#if {self.c_compile_guard}"
        return super_guard


class PyArgDeclNode(Node):
    # Argument which must be a Python object (used
    # for * and ** arguments).
    #
    # name        string
    # entry       Symtab.Entry
    # annotation  ExprNode or None   Py3 argument annotation
    child_attrs = []
    is_self_arg = False
    is_type_arg = False

    def generate_function_definitions(self, env, code):
        self.entry.generate_function_definitions(env, code)


class DecoratorNode(Node):
    # A decorator
    #
    # decorator    ExprNode
    child_attrs = ['decorator']


class DefNode(FuncDefNode):
    # A Python function definition.
    #
    # name          string                 the Python name of the function
    # lambda_name   string                 the internal name of a lambda 'function'
    # decorators    [DecoratorNode]        list of decorators
    # args          [CArgDeclNode]         formal arguments
    # doc           EncodedString or None
    # body          StatListNode
    # return_type_annotation
    #               ExprNode or None       the Py3 return type annotation
    #
    #  The following subnode is constructed internally
    #  when the def statement is inside a Python class definition.
    #
    #  fused_py_func        DefNode     The original fused cpdef DefNode
    #                                   (in case this is a specialization)
    #  specialized_cpdefs   [DefNode]   list of specialized cpdef DefNodes
    #  py_cfunc_node  PyCFunctionNode/InnerFunctionNode   The PyCFunction to create and assign
    #
    # decorator_indirection IndirectionNode Used to remove __Pyx_Method_ClassMethod for fused functions

    child_attrs = ["args", "star_arg", "starstar_arg", "body", "decorators", "return_type_annotation"]
    outer_attrs = ["decorators", "return_type_annotation"]

    is_staticmethod = False
    is_classmethod = False

    lambda_name = None
    reqd_kw_flags_cname = "0"
    is_wrapper = 0
    no_assignment_synthesis = 0
    decorators = None
    return_type_annotation = None
    entry = None
    acquire_gil = 0
    self_in_stararg = 0
    py_cfunc_node = None
    requires_classobj = False
    defaults_struct = None  # Dynamic kwrds structure name
    doc = None

    fused_py_func = False
    specialized_cpdefs = None
    py_wrapper = None
    py_wrapper_required = True
    func_cname = None

    defaults_getter = None

    def __init__(self, pos, **kwds):
        FuncDefNode.__init__(self, pos, **kwds)
        # Prepare signature information for code objects.
        p = k = rk = r = 0
        for arg in self.args:
            if arg.pos_only:
                p += 1
            if arg.kw_only:
                k += 1
                if not arg.default:
                    rk += 1
            if not arg.default:
                r += 1
        self.num_posonly_args = p
        self.num_kwonly_args = k
        self.num_required_kw_args = rk
        self.num_required_args = r

    def as_cfunction(self, cfunc=None, scope=None, overridable=True, returns=None, except_val=None, has_explicit_exc_clause=False,
                     modifiers=None, nogil=False, with_gil=False):
        if self.star_arg:
            error(self.star_arg.pos, "cdef function cannot have star argument")
        if self.starstar_arg:
            error(self.starstar_arg.pos, "cdef function cannot have starstar argument")
        exception_value, exception_check = except_val or (None, False)
        nogil = nogil or with_gil

        if cfunc is None:
            cfunc_args = []
            for formal_arg in self.args:
                name_declarator, type = formal_arg.analyse(scope, nonempty=1)
                cfunc_args.append(PyrexTypes.CFuncTypeArg(name=name_declarator.name,
                                                          cname=None,
                                                          annotation=formal_arg.annotation,
                                                          type=py_object_type,
                                                          pos=formal_arg.pos))
            cfunc_type = PyrexTypes.CFuncType(return_type=py_object_type,
                                              args=cfunc_args,
                                              has_varargs=False,
                                              exception_value=None,
                                              exception_check=exception_check,
                                              nogil=nogil,
                                              with_gil=with_gil,
                                              is_overridable=overridable)
            cfunc = CVarDefNode(self.pos, type=cfunc_type)
        else:
            if scope is None:
                scope = cfunc.scope
            cfunc_type = cfunc.type
            if cfunc_type.exception_check:
                # this ensures `legacy_implicit_noexcept` does not trigger
                # as it would result in a mismatch
                # (declaration with except, definition with implicit noexcept)
                has_explicit_exc_clause = True
            if len(self.args) != len(cfunc_type.args) or cfunc_type.has_varargs:
                error(self.pos, "wrong number of arguments")
                error(cfunc.pos, "previous declaration here")
            for i, (formal_arg, type_arg) in enumerate(zip(self.args, cfunc_type.args)):
                name_declarator, type = formal_arg.analyse(scope, nonempty=1,
                                                           is_self_arg=(i == 0 and scope.is_c_class_scope))
                if type is None or type is PyrexTypes.py_object_type:
                    formal_arg.type = type_arg.type
                    formal_arg.name_declarator = name_declarator

        if exception_value is None and cfunc_type.exception_value is not None:
            from .ExprNodes import ConstNode
            exception_value = ConstNode.for_type(
                self.pos, value=str(cfunc_type.exception_value), type=cfunc_type.return_type,
                constant_result=cfunc_type.exception_value.python_value)
        declarator = CFuncDeclaratorNode(self.pos,
                                         base=CNameDeclaratorNode(self.pos, name=self.name, cname=None),
                                         args=self.args,
                                         has_varargs=False,
                                         exception_check=cfunc_type.exception_check,
                                         exception_value=exception_value,
                                         has_explicit_exc_clause = has_explicit_exc_clause,
                                         with_gil=cfunc_type.with_gil,
                                         nogil=cfunc_type.nogil)
        return CFuncDefNode(self.pos,
                            modifiers=modifiers or [],
                            base_type=CAnalysedBaseTypeNode(self.pos, type=cfunc_type.return_type),
                            declarator=declarator,
                            body=self.body,
                            doc=self.doc,
                            overridable=cfunc_type.is_overridable,
                            type=cfunc_type,
                            with_gil=cfunc_type.with_gil,
                            nogil=cfunc_type.nogil,
                            visibility='private',
                            api=False,
                            directive_locals=getattr(cfunc, 'directive_locals', {}),
                            directive_returns=returns)

    def is_cdef_func_compatible(self):
        """Determines if the function's signature is compatible with a
        cdef function.  This can be used before calling
        .as_cfunction() to see if that will be successful.
        """
        if self.needs_closure:
            return False
        if self.star_arg or self.starstar_arg:
            return False
        return True

    def analyse_declarations(self, env):
        if self.decorators:
            for decorator in self.decorators:
                func = decorator.decorator
                if func.is_name:
                    self.is_classmethod |= func.name == 'classmethod'
                    self.is_staticmethod |= func.name == 'staticmethod'

        if self.is_classmethod and env.lookup_here('classmethod'):
            # classmethod() was overridden - not much we can do here ...
            self.is_classmethod = False
        if self.is_staticmethod and env.lookup_here('staticmethod'):
            # staticmethod() was overridden - not much we can do here ...
            self.is_staticmethod = False

        if env.is_py_class_scope or env.is_c_class_scope:
            if self.name == '__new__' and env.is_py_class_scope:
                self.is_staticmethod = True
            elif self.name == '__init_subclass__' and env.is_c_class_scope:
                error(self.pos, "'__init_subclass__' is not supported by extension class")
            elif self.name in IMPLICIT_CLASSMETHODS and not self.is_classmethod:
                self.is_classmethod = True
                # TODO: remove the need to generate a real decorator here, is_classmethod=True should suffice.
                from .ExprNodes import NameNode
                self.decorators = self.decorators or []
                self.decorators.insert(0, DecoratorNode(
                    self.pos, decorator=NameNode(self.pos, name=EncodedString('classmethod'))))

        self.analyse_argument_types(env)
        if self.name == '<lambda>':
            self.declare_lambda_function(env)
        else:
            self.declare_pyfunction(env)

        self.analyse_signature(env)
        self.return_type = self.entry.signature.return_type()
        # if a signature annotation provides a more specific return object type, use it
        if self.return_type is py_object_type and self.return_type_annotation:
            if env.directives['annotation_typing'] and not self.entry.is_special:
                _, return_type = self.return_type_annotation.analyse_type_annotation(env)
                if return_type and return_type.is_pyobject:
                    self.return_type = return_type

        self.create_local_scope(env)

        self.py_wrapper = DefNodeWrapper(
            self.pos,
            target=self,
            name=self.entry.name,
            args=self.args,
            star_arg=self.star_arg,
            starstar_arg=self.starstar_arg,
            return_type=self.return_type)
        self.py_wrapper.analyse_declarations(env)

    def analyse_argument_types(self, env):
        self.directive_locals = env.directives.get('locals', {})
        allow_none_for_extension_args = env.directives['allow_none_for_extension_args']

        f2s = env.fused_to_specific
        env.fused_to_specific = None

        for arg in self.args:
            if hasattr(arg, 'name'):
                name_declarator = None
            else:
                base_type = arg.base_type.analyse(env)
                # If we hare in pythran mode and we got a buffer supported by
                # Pythran, we change this node to a fused type
                if has_np_pythran(env) and base_type.is_pythran_expr:
                    base_type = PyrexTypes.FusedType([
                        base_type,
                        #PyrexTypes.PythranExpr(pythran_type(self.type, "numpy_texpr")),
                        base_type.org_buffer])
                name_declarator, type = \
                    arg.declarator.analyse(base_type, env)
                arg.name = name_declarator.name
                arg.type = type

            self.align_argument_type(env, arg)
            if name_declarator and name_declarator.cname:
                error(self.pos, "Python function argument cannot have C name specification")
            arg.type = arg.type.as_argument_type()
            arg.hdr_type = None
            arg.needs_conversion = 0
            arg.needs_type_test = 0
            arg.is_generic = 1
            if arg.type.is_pyobject or arg.type.is_buffer or arg.type.is_memoryviewslice:
                if arg.or_none:
                    arg.accept_none = True
                elif arg.not_none:
                    arg.accept_none = False
                elif (arg.type.is_extension_type or arg.type.is_builtin_type
                        or arg.type.is_buffer or arg.type.is_memoryviewslice):
                    if arg.default and arg.default.constant_result is None:
                        # special case: def func(MyType obj = None)
                        arg.accept_none = True
                    else:
                        # default depends on compiler directive
                        arg.accept_none = allow_none_for_extension_args
                else:
                    # probably just a plain 'object'
                    arg.accept_none = True
            elif not arg.type.is_error:
                arg.accept_none = True  # won't be used, but must be there
                if arg.not_none:
                    error(arg.pos, "Only Python type arguments can have 'not None'")
                if arg.or_none:
                    error(arg.pos, "Only Python type arguments can have 'or None'")

            if arg.type.is_fused:
                self.has_fused_arguments = True
        env.fused_to_specific = f2s

        if has_np_pythran(env):
            self.np_args_idx = [i for i,a in enumerate(self.args) if a.type.is_numpy_buffer]
        else:
            self.np_args_idx = []

    def analyse_signature(self, env):
        if self.entry.is_special:
            if self.decorators:
                error(self.pos, "special functions of cdef classes cannot have decorators")
            self.entry.trivial_signature = len(self.args) == 1 and not (self.star_arg or self.starstar_arg)
        elif not (self.star_arg or self.starstar_arg) and (
                not env.directives['always_allow_keywords']
                or all([arg.pos_only for arg in self.args])):
            # Use the simpler calling signature for zero- and one-argument pos-only functions.
            if self.entry.signature is TypeSlots.pyfunction_signature:
                if len(self.args) == 0:
                    self.entry.signature = TypeSlots.pyfunction_noargs
                elif len(self.args) == 1:
                    if self.args[0].default is None and not self.args[0].kw_only:
                        self.entry.signature = TypeSlots.pyfunction_onearg
            elif self.entry.signature is TypeSlots.pymethod_signature:
                if len(self.args) == 1:
                    self.entry.signature = TypeSlots.unaryfunc
                elif len(self.args) == 2:
                    if self.args[1].default is None and not self.args[1].kw_only:
                        self.entry.signature = TypeSlots.ibinaryfunc

        sig = self.entry.signature
        nfixed = sig.max_num_fixed_args()
        min_nfixed = sig.min_num_fixed_args()
        if (sig is TypeSlots.pymethod_signature and nfixed == 1
               and len(self.args) == 0 and self.star_arg):
            # this is the only case where a diverging number of
            # arguments is not an error - when we have no explicit
            # 'self' parameter as in method(*args)
            sig = self.entry.signature = TypeSlots.pyfunction_signature  # self is not 'really' used
            self.self_in_stararg = 1
            nfixed = min_nfixed = 0

        if self.is_staticmethod and env.is_c_class_scope:
            nfixed = min_nfixed = 0
            self.self_in_stararg = True  # FIXME: why for staticmethods?

            self.entry.signature = sig = copy.copy(sig)
            sig.fixed_arg_format = "*"
            sig.is_staticmethod = True
            sig.has_generic_args = True

        if ((self.is_classmethod or self.is_staticmethod) and
                self.has_fused_arguments and env.is_c_class_scope):
            del self.decorator_indirection.stats[:]

        for i in range(min(nfixed, len(self.args))):
            arg = self.args[i]
            arg.is_generic = 0
            if i >= min_nfixed:
                arg.is_special_method_optional = True
            if sig.is_self_arg(i) and not self.is_staticmethod:
                if self.is_classmethod:
                    arg.is_type_arg = 1
                    arg.hdr_type = arg.type = Builtin.type_type
                else:
                    arg.is_self_arg = 1
                    arg.hdr_type = arg.type = env.parent_type
                arg.needs_conversion = 0
            else:
                arg.hdr_type = sig.fixed_arg_type(i)
                if not arg.type.same_as(arg.hdr_type):
                    if arg.hdr_type.is_pyobject and arg.type.is_pyobject:
                        arg.needs_type_test = 1
                    else:
                        arg.needs_conversion = 1

        if min_nfixed > len(self.args):
            self.bad_signature()
            return
        elif nfixed < len(self.args):
            if not sig.has_generic_args:
                self.bad_signature()
            for arg in self.args:
                if arg.is_generic and (arg.type.is_extension_type or arg.type.is_builtin_type):
                    arg.needs_type_test = 1

        # Decide whether to use METH_FASTCALL
        # 1. If we use METH_NOARGS or METH_O, keep that. We can only change
        #    METH_VARARGS to METH_FASTCALL
        # 2. Special methods like __call__ always use the METH_VARGARGS
        #    calling convention
        mf = sig.method_flags()
        if mf and TypeSlots.method_varargs in mf and not self.entry.is_special:
            # 3. If the function uses the full args tuple, it's more
            #    efficient to use METH_VARARGS. This happens when the function
            #    takes *args but no other positional arguments (apart from
            #    possibly self). We don't do the analogous check for keyword
            #    arguments since the kwargs dict is copied anyway.
            if self.star_arg:
                uses_args_tuple = True
                for arg in self.args:
                    if (arg.is_generic and not arg.kw_only and
                            not arg.is_self_arg and not arg.is_type_arg):
                        # Other positional argument
                        uses_args_tuple = False
            else:
                uses_args_tuple = False

            if not uses_args_tuple:
                sig = self.entry.signature = sig.with_fastcall()

    def bad_signature(self):
        sig = self.entry.signature
        expected_str = "%d" % sig.min_num_fixed_args()
        if sig.has_generic_args:
            expected_str += " or more"
        elif sig.optional_object_arg_count:
            expected_str += " to %d" % sig.max_num_fixed_args()
        name = self.name
        if self.entry.is_special:
            desc = "Special method"
        else:
            desc = "Method"
        error(self.pos, "%s %s has wrong number of arguments (%d declared, %s expected)" % (
            desc, self.name, len(self.args), expected_str))

    def declare_pyfunction(self, env):
        #print "DefNode.declare_pyfunction:", self.name, "in", env ###
        name = self.name
        entry = env.lookup_here(name)
        if entry:
            if entry.is_final_cmethod and not env.parent_type.is_final_type:
                error(self.pos, "Only final types can have final Python (def/cpdef) methods")
            if entry.type.is_cfunction and not entry.is_builtin_cmethod and not self.is_wrapper:
                warning(self.pos, "Overriding a c(p)def method with a def method. "
                        "This can lead to different methods being called depending on the "
                        "call context. Consider using a cpdef method for both.", 5)
        entry = env.declare_pyfunction(name, self.pos, allow_redefine=not self.is_wrapper)
        self.entry = entry
        prefix = env.next_id(env.scope_prefix)
        self.entry.pyfunc_cname = punycodify_name(Naming.pyfunc_prefix + prefix + name)
        if Options.docstrings:
            entry.doc = embed_position(self.pos, self.doc)
            entry.doc_cname = punycodify_name(Naming.funcdoc_prefix + prefix + name)
            if entry.is_special:
                if entry.name in TypeSlots.invisible or not entry.doc or (
                        entry.name in '__getattr__' and env.directives['fast_getattr']):
                    entry.wrapperbase_cname = None
                else:
                    entry.wrapperbase_cname = punycodify_name(Naming.wrapperbase_prefix + prefix + name)
        else:
            entry.doc = None

    def declare_lambda_function(self, env):
        entry = env.declare_lambda_function(self.lambda_name, self.pos)
        entry.doc = None
        self.entry = entry
        self.entry.pyfunc_cname = entry.cname

    def declare_arguments(self, env):
        for arg in self.args:
            if not arg.name:
                error(arg.pos, "Missing argument name")
            if arg.needs_conversion:
                arg.entry = env.declare_var(arg.name, arg.type, arg.pos)
                if arg.type.is_pyobject:
                    arg.entry.init = "0"
            else:
                arg.entry = self.declare_argument(env, arg)
            arg.entry.is_arg = 1
            arg.entry.used = 1
            arg.entry.is_self_arg = arg.is_self_arg
        self.declare_python_arg(env, self.star_arg)
        self.declare_python_arg(env, self.starstar_arg)

    def declare_python_arg(self, env, arg):
        if arg:
            if env.directives['infer_types'] != False:
                type = PyrexTypes.unspecified_type
            else:
                type = py_object_type
            entry = env.declare_var(arg.name, type, arg.pos)
            entry.is_arg = 1
            entry.used = 1
            entry.init = "0"
            entry.xdecref_cleanup = 1
            arg.entry = entry

    def analyse_expressions(self, env):
        self.local_scope.directives = env.directives
        self.analyse_default_values(env)
        self.analyse_annotations(env)

        if not self.needs_assignment_synthesis(env) and self.decorators:
            for decorator in self.decorators[::-1]:
                decorator.decorator = decorator.decorator.analyse_expressions(env)

        self.py_wrapper.prepare_argument_coercion(env)
        return self

    def needs_assignment_synthesis(self, env, code=None):
        if self.is_staticmethod:
            return True
        if self.specialized_cpdefs or self.entry.is_fused_specialized:
            return False
        if self.no_assignment_synthesis:
            return False
        if self.entry.is_special:
            return False
        if self.entry.is_anonymous:
            return True
        if env.is_module_scope or env.is_c_class_scope:
            if code is None:
                return self.local_scope.directives['binding']
            else:
                return code.globalstate.directives['binding']
        return env.is_py_class_scope or env.is_closure_scope

    def error_value(self):
        return self.entry.signature.error_value

    def caller_will_check_exceptions(self):
        return self.entry.signature.exception_check

    def generate_function_definitions(self, env, code):
        if self.defaults_getter:
            # defaults getter must never live in class scopes, it's always a module function
            module_scope = env.global_scope()
            directives_node = CompilerDirectivesNode.for_internal(self.defaults_getter, module_scope)
            directives_node.generate_function_definitions(module_scope, code)

        # Before closure cnames are mangled
        if self.py_wrapper_required:
            # func_cname might be modified by @cname
            self.py_wrapper.func_cname = self.entry.func_cname
            self.py_wrapper.generate_function_definitions(env, code)
        FuncDefNode.generate_function_definitions(self, env, code)

    def generate_function_header(self, code, with_pymethdef, proto_only=0):
        if proto_only:
            if self.py_wrapper_required:
                self.py_wrapper.generate_function_header(
                    code, with_pymethdef, True)
            return
        arg_code_list = []
        if self.entry.signature.has_dummy_arg:
            self_arg = 'PyObject *%s' % Naming.self_cname
            if not self.needs_outer_scope:
                self_arg = 'CYTHON_UNUSED ' + self_arg
            arg_code_list.append(self_arg)

        def arg_decl_code(arg):
            entry = arg.entry
            if entry.in_closure:
                cname = entry.original_cname
            else:
                cname = entry.cname
            decl = entry.type.declaration_code(cname)
            if not entry.cf_used:
                decl = 'CYTHON_UNUSED ' + decl
            return decl

        for arg in self.args:
            arg_code_list.append(arg_decl_code(arg))
        if self.star_arg:
            arg_code_list.append(arg_decl_code(self.star_arg))
        if self.starstar_arg:
            arg_code_list.append(arg_decl_code(self.starstar_arg))
        if arg_code_list:
            arg_code = ', '.join(arg_code_list)
        else:
            arg_code = 'void'  # No arguments
        dc = self.return_type.declaration_code(self.entry.pyfunc_cname)

        decls_code = code.globalstate['decls']
        preprocessor_guard = self.get_preprocessor_guard()
        if preprocessor_guard:
            decls_code.putln(preprocessor_guard)
        decls_code.putln(
            "static %s(%s); /* proto */" % (dc, arg_code))
        if preprocessor_guard:
            decls_code.putln("#endif")
        code.putln("static %s(%s) {" % (dc, arg_code))

    def generate_argument_declarations(self, env, code):
        pass

    def generate_keyword_list(self, code):
        pass

    def generate_argument_parsing_code(self, env, code):
        # Move arguments into closure if required
        def put_into_closure(entry):
            if entry.in_closure:
                if entry.type.is_array:
                    # This applies to generator expressions that iterate over C arrays (and need to
                    # capture them by value), under most other circumstances C array arguments are dropped to
                    # pointers so this copy isn't used
                    assert entry.type.size is not None
                    code.globalstate.use_utility_code(UtilityCode.load_cached("IncludeStringH", "StringTools.c"))
                    code.putln("memcpy({0}, {1}, sizeof({0}));".format(entry.cname, entry.original_cname))
                else:
                    code.putln('%s = %s;' % (entry.cname, entry.original_cname))
                if entry.type.is_memoryviewslice:
                    # TODO - at some point reference count of memoryviews should
                    # genuinely be unified with PyObjects
                    entry.type.generate_incref_memoryviewslice(code, entry.cname, True)
                elif entry.xdecref_cleanup:
                    # mostly applies to the starstar arg - this can sometimes be NULL
                    # so must be xincrefed instead
                    code.put_var_xincref(entry)
                    code.put_var_xgiveref(entry)
                else:
                    code.put_var_incref(entry)
                    code.put_var_giveref(entry)
        for arg in self.args:
            put_into_closure(arg.entry)
        for arg in self.star_arg, self.starstar_arg:
            if arg:
                put_into_closure(arg.entry)

    def generate_argument_type_tests(self, code):
        pass


class DefNodeWrapper(FuncDefNode):
    # DefNode python wrapper code generator

    defnode = None
    target = None  # Target DefNode
    needs_values_cleanup = False

    def __init__(self, *args, **kwargs):
        FuncDefNode.__init__(self, *args, **kwargs)
        self.num_posonly_args = self.target.num_posonly_args
        self.num_kwonly_args = self.target.num_kwonly_args
        self.num_required_kw_args = self.target.num_required_kw_args
        self.num_required_args = self.target.num_required_args
        self.self_in_stararg = self.target.self_in_stararg
        self.signature = None

    def analyse_declarations(self, env):
        target_entry = self.target.entry
        name = self.name
        prefix = env.next_id(env.scope_prefix)
        target_entry.func_cname = punycodify_name(Naming.pywrap_prefix + prefix + name)
        target_entry.pymethdef_cname = punycodify_name(Naming.pymethdef_prefix + prefix + name)

        self.signature = target_entry.signature

        self.np_args_idx = self.target.np_args_idx

    def prepare_argument_coercion(self, env):
        # This is only really required for Cython utility code at this time,
        # everything else can be done during code generation.  But we expand
        # all utility code here, simply because we cannot easily distinguish
        # different code types.
        for arg in self.args:
            if not arg.type.is_pyobject:
                if not arg.type.create_from_py_utility_code(env):
                    pass  # will fail later
            elif arg.hdr_type and not arg.hdr_type.is_pyobject:
                if not arg.hdr_type.create_to_py_utility_code(env):
                    pass  # will fail later

        if self.starstar_arg and not self.starstar_arg.entry.cf_used:
            # we will set the kwargs argument to NULL instead of a new dict
            # and must therefore correct the control flow state
            entry = self.starstar_arg.entry
            entry.xdecref_cleanup = 1
            for ass in entry.cf_assignments:
                if not ass.is_arg and ass.lhs.is_name:
                    ass.lhs.cf_maybe_null = True

    def signature_has_nongeneric_args(self):
        argcount = len(self.args)
        if argcount == 0 or (
                argcount == 1 and (self.args[0].is_self_arg or
                                   self.args[0].is_type_arg)):
            return 0
        return 1

    def signature_has_generic_args(self):
        return self.signature.has_generic_args

    def generate_function_body(self, code):
        args = []
        if self.signature.has_dummy_arg:
            args.append(Naming.self_cname)
        for arg in self.args:
            if arg.type.is_cpp_class:
                # it's safe to move converted C++ types because they aren't
                # used again afterwards
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached("MoveIfSupported", "CppSupport.cpp"))
                args.append("__PYX_STD_MOVE_IF_SUPPORTED(%s)" % arg.entry.cname)
            elif arg.hdr_type and not (arg.type.is_memoryviewslice or
                                     arg.type.is_struct or
                                     arg.type.is_complex):
                args.append(arg.type.cast_code(arg.entry.cname))
            else:
                args.append(arg.entry.cname)
        if self.star_arg:
            args.append(self.star_arg.entry.cname)
        if self.starstar_arg:
            args.append(self.starstar_arg.entry.cname)
        args = ', '.join(args)
        if not self.return_type.is_void:
            code.put('%s = ' % Naming.retval_cname)
        code.putln('%s(%s);' % (
            self.target.entry.pyfunc_cname, args))

    def generate_function_definitions(self, env, code):
        lenv = self.target.local_scope
        # Generate C code for header and body of function
        code.mark_pos(self.pos)
        code.putln("")
        code.putln("/* Python wrapper */")
        preprocessor_guard = self.target.get_preprocessor_guard()
        if preprocessor_guard:
            code.putln(preprocessor_guard)

        code.enter_cfunc_scope(lenv)
        code.return_from_error_cleanup_label = code.new_label()

        with_pymethdef = (self.target.needs_assignment_synthesis(env, code) or
                          self.target.pymethdef_required)
        self.generate_function_header(code, with_pymethdef)
        self.generate_argument_declarations(lenv, code)
        tempvardecl_code = code.insertion_point()

        if self.return_type.is_pyobject:
            retval_init = ' = 0'
        else:
            retval_init = ''
        if not self.return_type.is_void:
            code.putln('%s%s;' % (
                self.return_type.declaration_code(Naming.retval_cname),
                retval_init))
        code.put_declare_refcount_context()
        code.put_setup_refcount_context(EncodedString('%s (wrapper)' % self.name))

        self.generate_argument_parsing_code(lenv, code, tempvardecl_code)
        self.generate_argument_type_tests(code)
        self.generate_function_body(code)

        # ----- Go back and insert temp variable declarations
        tempvardecl_code.put_temp_declarations(code.funcstate)

        code.mark_pos(self.pos)
        code.putln("")
        code.putln("/* function exit code */")

        # ----- Error cleanup
        values_cleaned_up_label = code.new_label("cleaned_up")
        if code.label_used(code.error_label):
            code.put_goto(code.return_label)
            code.put_label(code.error_label)
            for cname, type in code.funcstate.all_managed_temps():
                code.put_xdecref(cname, type)
            err_val = self.error_value()
            if err_val is not None:
                code.putln("%s = %s;" % (Naming.retval_cname, err_val))

            # We use separate cleanup paths for the success/error cases to help the
            # C compiler optimise the success case (e.g. remove the NULL check in XDECREFs).
            self.generate_argument_values_cleanup_code(code)
            code.put_goto(values_cleaned_up_label)

        # ----- Non-error return cleanup
        code.put_label(code.return_label)

        self.generate_argument_values_cleanup_code(code)
        code.put_label(values_cleaned_up_label)

        for entry in lenv.var_entries:
            if entry.is_arg:
                if entry.xdecref_cleanup:
                    code.put_var_xdecref(entry)
                else:
                    code.put_var_decref(entry)
        var_entries_set = set(lenv.var_entries)
        for arg in self.args:
            if not arg.type.is_pyobject and arg.entry not in var_entries_set:
                # This captures anything that's been converted from a PyObject.
                # Primarily memoryviews at the moment
                if arg.entry.xdecref_cleanup:
                    code.put_var_xdecref(arg.entry)
                else:
                    code.put_var_decref(arg.entry)

        code.put_finish_refcount_context()
        if not self.return_type.is_void:
            code.putln("return %s;" % Naming.retval_cname)
        code.putln('}')
        code.exit_cfunc_scope()
        if preprocessor_guard:
            code.putln("#endif /*!(%s)*/" % preprocessor_guard)

    def generate_function_header(self, code, with_pymethdef, proto_only=0):
        arg_code_list = []
        sig = self.signature

        if sig.has_dummy_arg or self.self_in_stararg:
            arg_code = "PyObject *%s" % Naming.self_cname
            if not sig.has_dummy_arg:
                arg_code = 'CYTHON_UNUSED ' + arg_code
            arg_code_list.append(arg_code)

        for arg in self.args:
            if not arg.is_generic:
                if arg.is_self_arg or arg.is_type_arg:
                    arg_code_list.append("PyObject *%s" % arg.hdr_cname)
                else:
                    arg_code_list.append(
                        arg.hdr_type.declaration_code(arg.hdr_cname))
        entry = self.target.entry
        if not entry.is_special and sig.method_flags() == [TypeSlots.method_noargs]:
            arg_code_list.append("CYTHON_UNUSED PyObject *unused")
        if sig.has_generic_args:
            varargs_args = "PyObject *%s, PyObject *%s" % (
                    Naming.args_cname, Naming.kwds_cname)
            if sig.use_fastcall:
                fastcall_args = "PyObject *const *%s, Py_ssize_t %s, PyObject *%s" % (
                        Naming.args_cname, Naming.nargs_cname, Naming.kwds_cname)
                arg_code_list.append(
                    "\n#if CYTHON_METH_FASTCALL\n%s\n#else\n%s\n#endif\n" % (
                        fastcall_args, varargs_args))
            else:
                arg_code_list.append(varargs_args)
        if entry.is_special:
            for n in range(len(self.args), sig.max_num_fixed_args()):
                arg_code_list.append("CYTHON_UNUSED PyObject *unused_arg_%s" % n)
        arg_code = ", ".join(arg_code_list)

        # Prevent warning: unused function '__pyx_pw_5numpy_7ndarray_1__getbuffer__'
        mf = ""
        if (entry.name in ("__getbuffer__", "__releasebuffer__")
                and entry.scope.is_c_class_scope):
            mf = "CYTHON_UNUSED "
            with_pymethdef = False

        dc = self.return_type.declaration_code(entry.func_cname)
        header = "%sstatic %s(%s)" % (mf, dc, arg_code)
        code.putln("%s; /*proto*/" % header)

        if proto_only:
            if self.target.fused_py_func:
                # If we are the specialized version of the cpdef, we still
                # want the prototype for the "fused cpdef", in case we're
                # checking to see if our method was overridden in Python
                self.target.fused_py_func.generate_function_header(
                    code, with_pymethdef, proto_only=True)
            return

        if (Options.docstrings and entry.doc and
                not self.target.fused_py_func and
                not entry.scope.is_property_scope and
                (not entry.is_special or entry.wrapperbase_cname)):
            # h_code = code.globalstate['h_code']
            docstr = entry.doc

            if docstr.is_unicode:
                docstr = docstr.as_utf8_string()

            if not (entry.is_special and entry.name in ('__getbuffer__', '__releasebuffer__')):
                code.putln('PyDoc_STRVAR(%s, %s);' % (
                    entry.doc_cname,
                    docstr.as_c_string_literal()))

            if entry.is_special:
                code.putln('#if CYTHON_UPDATE_DESCRIPTOR_DOC')
                code.putln(
                    "struct wrapperbase %s;" % entry.wrapperbase_cname)
                code.putln('#endif')

        if with_pymethdef or self.target.fused_py_func:
            code.put(
                "static PyMethodDef %s = " % entry.pymethdef_cname)
            code.put_pymethoddef(self.target.entry, ";", allow_skip=False)
        code.putln("%s {" % header)

    def generate_argument_declarations(self, env, code):
        for arg in self.args:
            if arg.is_generic:
                if arg.needs_conversion:
                    code.putln("PyObject *%s = 0;" % arg.hdr_cname)
                else:
                    code.put_var_declaration(arg.entry)
        for entry in env.var_entries:
            if entry.is_arg:
                code.put_var_declaration(entry)

        # Create nargs, but avoid an "unused" warning in the few cases where we don't need it.
        if self.signature_has_generic_args():
            # error handling for this is checked after the declarations
            nargs_code = "CYTHON_UNUSED Py_ssize_t %s;" % Naming.nargs_cname
            if self.signature.use_fastcall:
                code.putln("#if !CYTHON_METH_FASTCALL")
                code.putln(nargs_code)
                code.putln("#endif")
            else:
                code.putln(nargs_code)

        # Array containing the values of keyword arguments when using METH_FASTCALL.
        code.putln('CYTHON_UNUSED PyObject *const *%s;' % Naming.kwvalues_cname)

    def generate_argument_parsing_code(self, env, code, decl_code):
        # Generate fast equivalent of PyArg_ParseTuple call for
        # generic arguments, if any, including args/kwargs
        old_error_label = code.new_error_label()
        our_error_label = code.error_label
        end_label = code.new_label("argument_unpacking_done")

        has_kwonly_args = self.num_kwonly_args > 0
        has_star_or_kw_args = self.star_arg is not None \
            or self.starstar_arg is not None or has_kwonly_args

        for arg in self.args:
            if not arg.type.is_pyobject:
                if not arg.type.create_from_py_utility_code(env):
                    pass  # will fail later

        # Assign nargs variable as len(args).
        if self.signature_has_generic_args():
            if self.signature.use_fastcall:
                code.putln("#if !CYTHON_METH_FASTCALL")
            code.putln("#if CYTHON_ASSUME_SAFE_SIZE")
            code.putln("%s = PyTuple_GET_SIZE(%s);" % (
                Naming.nargs_cname, Naming.args_cname))
            code.putln("#else")
            # An error here is very unlikely, but we risk a (conditionally) unused error label,
            # so we just skip the traceback and return immediately.
            code.putln("%s = PyTuple_Size(%s); if (%s) return %s;" % (
                Naming.nargs_cname,
                Naming.args_cname,
                code.unlikely("%s < 0" % Naming.nargs_cname),
                self.error_value(),
            ))
            code.putln("#endif")
            if self.signature.use_fastcall:
                code.putln("#endif")
        code.globalstate.use_utility_code(
            UtilityCode.load_cached("fastcall", "FunctionArguments.c"))
        code.putln('%s = __Pyx_KwValues_%s(%s, %s);' % (
            Naming.kwvalues_cname, self.signature.fastvar, Naming.args_cname, Naming.nargs_cname))

        if not self.signature_has_generic_args():
            if has_star_or_kw_args:
                error(self.pos, "This method cannot have * or keyword arguments")
            self.generate_argument_conversion_code(code)

        elif not self.signature_has_nongeneric_args():
            # func(*args) or func(**kw) or func(*args, **kw)
            # possibly with a "self" argument but no other non-star
            # arguments
            self.generate_stararg_copy_code(code)

        else:
            self.generate_tuple_and_keyword_parsing_code(self.args, code, decl_code)
            self.needs_values_cleanup = True

        code.error_label = old_error_label
        if code.label_used(our_error_label):
            code.put_goto(end_label)
            code.put_label(our_error_label)
            self.generate_argument_values_cleanup_code(code)

            if has_star_or_kw_args:
                self.generate_arg_decref(self.star_arg, code)
                if self.starstar_arg:
                    if self.starstar_arg.entry.xdecref_cleanup:
                        code.put_var_xdecref_clear(self.starstar_arg.entry)
                    else:
                        code.put_var_decref_clear(self.starstar_arg.entry)
            for arg in self.args:
                if not arg.type.is_pyobject and arg.type.needs_refcounting:
                    # at the moment this just catches memoryviewslices, but in future
                    # other non-PyObject reference counted types might need cleanup
                    code.put_var_xdecref(arg.entry)
            code.put_add_traceback(self.target.entry.qualified_name)
            code.put_finish_refcount_context()
            code.putln("return %s;" % self.error_value())

        code.put_label(end_label)

    def generate_arg_xdecref(self, arg, code):
        if arg:
            code.put_var_xdecref_clear(arg.entry)

    def generate_arg_decref(self, arg, code):
        if arg:
            code.put_var_decref_clear(arg.entry)

    def generate_stararg_copy_code(self, code):
        # Direct error return simplifies **kwargs cleanup, but we give no traceback.
        goto_error = f"return {self.error_value()};"
        function_name = self.name.as_c_string_literal()

        if not self.star_arg:
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("RaiseArgTupleInvalid", "FunctionArguments.c"))
            code.putln(
                f"if (unlikely({Naming.nargs_cname} > 0)) "
                "{"
                f" __Pyx_RaiseArgtupleInvalid({function_name}, 1, 0, 0, {Naming.nargs_cname}); "
                f"{goto_error} "
                "}"
            )

        code.putln(
            f"const Py_ssize_t {Naming.kwds_len_cname} = "
            f"{'' if self.starstar_arg else 'unlikely'}({Naming.kwds_cname}) ? "
            f"__Pyx_NumKwargs_{self.signature.fastvar}({Naming.kwds_cname}) : 0;"
        )
        code.putln(f"if (unlikely({Naming.kwds_len_cname} < 0)) {goto_error}")

        if self.starstar_arg:
            code.putln(f"if ({Naming.kwds_len_cname} > 0) {{")

            code.globalstate.use_utility_code(
                UtilityCode.load_cached("KeywordStringCheck", "FunctionArguments.c"))
            code.putln(
                f"if (unlikely(__Pyx_CheckKeywordStrings({function_name}, {Naming.kwds_cname}) == -1)) {goto_error}"
            )

            # If the **kwargs parameter is unused, we leave it NULL.
            if self.starstar_arg.entry.cf_used:
                self.starstar_arg.entry.xdecref_cleanup = False
                starstar_arg_cname = self.starstar_arg.entry.cname
                code.putln(
                    f"{starstar_arg_cname} = __Pyx_KwargsAsDict_{self.signature.fastvar}("
                    f"{Naming.kwds_cname}, {Naming.kwvalues_cname}"
                    ");"
                )
                code.putln(f"if (unlikely(!{starstar_arg_cname})) {goto_error}")
                code.put_var_gotref(self.starstar_arg.entry)

                code.putln("} else {")
                code.putln(f"{starstar_arg_cname} = PyDict_New();")
                code.putln(f"if (unlikely(!{starstar_arg_cname})) {goto_error}")
                code.put_var_gotref(self.starstar_arg.entry)

            code.putln("}")

        else:
            # No **kwargs => no keywords allowed (nor expected).
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("RejectKeywords", "FunctionArguments.c"))
            code.putln(
                f"if (unlikely({Naming.kwds_len_cname} > 0)) "
                "{"
                f"__Pyx_RejectKeywords({function_name}, {Naming.kwds_cname}); "
                f"{goto_error}"
                "}"
            )

        # Normal (traceback) error handling from this point on to clean up the kwargs dict.

        if self.self_in_stararg and not self.target.is_staticmethod:
            assert not self.signature.use_fastcall
            star_arg_cname = self.star_arg.entry.cname
            # need to create a new tuple with 'self' inserted as first item
            code.putln(
                f"{star_arg_cname} = PyTuple_New({Naming.nargs_cname} + 1); "
                f"{code.error_goto_if_null(star_arg_cname, self.pos)}"
            )
            code.put_var_gotref(self.star_arg.entry)
            code.put_incref(Naming.self_cname, py_object_type)
            code.put_giveref(Naming.self_cname, py_object_type)
            code.putln(
                code.error_goto_if_neg(f"__Pyx_PyTuple_SET_ITEM({star_arg_cname}, 0, {Naming.self_cname})", self.pos))
            temp = code.funcstate.allocate_temp(PyrexTypes.c_py_ssize_t_type, manage_ref=False)
            code.putln(
                f"for ({temp}=0; {temp} < {Naming.nargs_cname}; {temp}++) {{")
            code.putln(
                f"PyObject* item = __Pyx_PyTuple_GET_ITEM({Naming.args_cname}, {temp});")
            code.putln("#if !CYTHON_ASSUME_SAFE_MACROS")
            code.putln(code.error_goto_if_null("item", self.pos))
            code.putln("#endif")
            code.put_incref("item", py_object_type)
            code.put_giveref("item", py_object_type)
            code.putln(
                code.error_goto_if_neg(f"__Pyx_PyTuple_SET_ITEM({star_arg_cname}, {temp}+1, item)", self.pos))
            code.putln("}")
            code.funcstate.release_temp(temp)
            self.star_arg.entry.xdecref_cleanup = 0
        elif self.star_arg:
            assert not self.signature.use_fastcall
            star_arg_cname = self.star_arg.entry.cname
            code.put_incref(Naming.args_cname, py_object_type)
            code.putln(
                f"{star_arg_cname} = {Naming.args_cname};")
            self.star_arg.entry.xdecref_cleanup = 0

    def generate_tuple_and_keyword_parsing_code(self, args, code, decl_code):
        code.globalstate.use_utility_code(
            UtilityCode.load_cached("fastcall", "FunctionArguments.c"))

        self_name_csafe = self.name.as_c_string_literal()

        argtuple_error_label = code.new_label("argtuple_error")
        goto_error = code.error_goto(self.pos)

        positional_args = []
        required_kw_only_args = []
        optional_kw_only_args = []
        num_pos_only_args = num_required_pos_only_args = 0
        for arg in args:
            if not arg.is_generic:
                continue
            if arg.is_self_arg or arg.is_type_arg:
                continue

            if arg.kw_only:
                (optional_kw_only_args if arg.default else required_kw_only_args).append(arg)
            else:
                positional_args.append(arg)
                if arg.pos_only:
                    num_pos_only_args += 1
                    if not arg.default:
                        num_required_pos_only_args += 1

        # sort required kw-only args before optional ones to avoid special
        # cases in the unpacking code
        kw_only_args = required_kw_only_args + optional_kw_only_args

        min_positional_args = self.num_required_args - self.num_required_kw_args
        if len(args) > 0 and (args[0].is_self_arg or args[0].is_type_arg):
            min_positional_args -= 1
        max_positional_args = len(positional_args)
        has_fixed_positional_count = not self.star_arg and \
            min_positional_args == max_positional_args
        has_kw_only_args = bool(kw_only_args)

        if self.starstar_arg or self.star_arg:
            self.generate_stararg_init_code(max_positional_args, code)

        all_args = tuple(positional_args) + tuple(kw_only_args)
        non_posonly_args = [arg for arg in all_args if not arg.pos_only]
        accept_kwd_args = non_posonly_args or self.starstar_arg

        code.putln('{')
        if accept_kwd_args:
            non_pos_args_id = ','.join([
                f'&{code.intern_identifier(arg.entry.name)}'
                for arg in non_posonly_args
            ] + ['0'])
            code.putln("PyObject ** const %s[] = {%s};" % (
                Naming.pykwdlist_cname,
                non_pos_args_id))

        # Before being converted and assigned to the target variables,
        # borrowed references to all unpacked argument values are
        # collected into a local PyObject* array called "values",
        # regardless if they were taken from default arguments,
        # positional arguments or keyword arguments.  Note that
        # C-typed default arguments are handled at conversion time,
        # so their array value is NULL in the end if no argument
        # was passed for them.
        self.generate_argument_values_setup_code(all_args, code, decl_code)

        # If all args are positional-only, we can raise an error
        # straight away if we receive a non-empty kw-dict.
        # This requires a PyDict_Size call.  This call is wasteful
        # for functions which do accept kw-args, so we do not generate
        # the PyDict_Size call unless all args are positional-only.
        code.putln(
            f"const Py_ssize_t {Naming.kwds_len_cname} = "
            f"{'' if accept_kwd_args else 'unlikely'}({Naming.kwds_cname}) ? "
            f"__Pyx_NumKwargs_{self.signature.fastvar}({Naming.kwds_cname}) : 0;"
        )
        code.putln(f"if (unlikely({Naming.kwds_len_cname}) < 0) {goto_error}")

        kw_unpacking_condition = f"{Naming.kwds_len_cname} > 0"
        if self.num_required_kw_args > 0:
            kw_unpacking_condition = "likely(%s)" % kw_unpacking_condition

        # --- optimised code when we receive keyword arguments
        code.putln("if (%s) {" % kw_unpacking_condition)

        if not accept_kwd_args:
            # We test above that there is at least one kwarg if we get here => reject it.
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("RejectKeywords", "FunctionArguments.c"))
            code.putln(f"__Pyx_RejectKeywords({self_name_csafe}, {Naming.kwds_cname}); {goto_error}")
        else:
            # Extract arguments from args and keywords.
            # Note: This may be different from the tuple unpacking code below since we cannot
            #       recognise missing arguments from the fact that they are missing from the
            #       positional arguments when keywords are provided as well.
            self.generate_posargs_unpacking_code(
                min_positional_args, max_positional_args,
                has_fixed_positional_count, has_kw_only_args, all_args, argtuple_error_label, code)

            self.generate_keyword_unpacking_code(
                max_positional_args, all_args, code)

            # Assign the default values to the empty entries of the 'values' array.
            self.generate_argument_defaults_assignment_code(all_args, code)

            # Validate required arguments after integrating keyword arguments (which cannot fill up posonly arguments).
            if min_positional_args > num_required_pos_only_args:
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached("RaiseArgTupleInvalid", "FunctionArguments.c"))
                code.putln(f"for (Py_ssize_t i = {Naming.nargs_cname}; i < {min_positional_args}; i++) {{")
                code.putln(
                    "if (unlikely(!values[i])) { "
                    "__Pyx_RaiseArgtupleInvalid("
                    f"{self_name_csafe}, "
                    f"{has_fixed_positional_count:d}, "
                    f"{min_positional_args:d}, "
                    f"{max_positional_args:d}, "
                    "i); "
                    f"{goto_error} "
                    "}"
                )
                code.putln("}")

            if self.num_required_kw_args:
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached("RaiseKeywordRequired", "FunctionArguments.c"))
                code.putln(f"for (Py_ssize_t i = {max_positional_args}; i < {max_positional_args + self.num_required_kw_args}; i++) {{")
                code.putln(
                    "if (unlikely(!values[i])) { "
                    "__Pyx_RaiseKeywordRequired("
                    f"{self_name_csafe}, "
                    f"*({Naming.pykwdlist_cname}[i - {num_pos_only_args}])"
                    "); "
                    f"{goto_error} "
                    "}"
                )
                code.putln("}")

        # --- optimised code when we do not receive any keyword arguments
        if (self.num_required_kw_args and min_positional_args > 0) or min_positional_args == max_positional_args:
            # Python raises arg tuple related errors first, so we must
            # check the length here
            if min_positional_args == max_positional_args and not self.star_arg:
                compare = '!='
            else:
                compare = '<'
            code.putln('} else if (unlikely(%s %s %d)) {' % (
                Naming.nargs_cname, compare, min_positional_args))
            code.put_goto(argtuple_error_label)

        if self.num_required_kw_args:
            # pure error case: keywords required but not passed
            if max_positional_args > min_positional_args and not self.star_arg:
                code.putln('} else if (unlikely(%s > %d)) {' % (
                    Naming.nargs_cname, max_positional_args))
                code.put_goto(argtuple_error_label)
            code.putln('} else {')
            for arg in kw_only_args:
                if not arg.default:
                    # required keyword-only argument missing
                    code.globalstate.use_utility_code(
                        UtilityCode.load_cached("RaiseKeywordRequired", "FunctionArguments.c"))
                    pystring_cname = code.intern_identifier(arg.entry.name)
                    code.putln(f'__Pyx_RaiseKeywordRequired({self_name_csafe}, {pystring_cname}); {goto_error}')
                    break

        else:
            # optimised tuple unpacking code
            code.putln('} else {')
            if min_positional_args == max_positional_args:
                # parse the exact number of positional arguments from
                # the args tuple
                for i, arg in enumerate(positional_args):
                    code.putln(
                        f"values[{i}] = __Pyx_ArgRef_{self.signature.fastvar}({Naming.args_cname}, {i});")
                    code.putln(f"if (!CYTHON_ASSUME_SAFE_MACROS && unlikely(!values[{i}])) {goto_error}")
            else:
                # parse the positional arguments from the variable length
                # args tuple and reject illegal argument tuple sizes
                code.putln(f'switch ({Naming.nargs_cname}) {{')
                if self.star_arg:
                    code.putln('default:')
                reversed_args = list(enumerate(positional_args))[::-1]
                for i, arg in reversed_args:
                    if i >= min_positional_args-1:
                        if i != reversed_args[0][0]:
                            code.putln('CYTHON_FALLTHROUGH;')
                        code.putln(f'case {i+1:2d}:')
                    code.putln(
                        f"values[{i}] = __Pyx_ArgRef_{self.signature.fastvar}({Naming.args_cname}, {i});")
                    code.putln(f"if (!CYTHON_ASSUME_SAFE_MACROS && unlikely(!values[{i}])) {goto_error}")
                if min_positional_args == 0:
                    code.putln('CYTHON_FALLTHROUGH;')
                    code.put('case  0: ')
                code.putln('break;')
                if self.star_arg:
                    if min_positional_args:
                        for i in range(min_positional_args-1, -1, -1):
                            code.putln(f'case {i:2d}:')
                        code.put_goto(argtuple_error_label)
                else:
                    code.put('default: ')
                    code.put_goto(argtuple_error_label)
                code.putln('}')

            # Assign the default values to the empty entries of the 'values' array.
            self.generate_argument_defaults_assignment_code(all_args, code)

        code.putln('}')  # end of the conditional unpacking blocks

        # Convert arg values to their final type and assign them.
        # Also inject non-Python default arguments, which do cannot
        # live in the values[] array.
        for i, arg in enumerate(all_args):
            self.generate_arg_assignment(arg, f"values[{i}]", code)

        code.putln('}')  # end of the whole argument unpacking block

        if code.label_used(argtuple_error_label):
            skip_error_handling = code.new_label("skip")
            code.put_goto(skip_error_handling)

            code.put_label(argtuple_error_label)
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("RaiseArgTupleInvalid", "FunctionArguments.c"))
            code.putln('__Pyx_RaiseArgtupleInvalid(%s, %d, %d, %d, %s); %s' % (
                self_name_csafe, has_fixed_positional_count,
                min_positional_args, max_positional_args,
                Naming.nargs_cname,
                goto_error,
            ))
            code.put_label(skip_error_handling)

    def generate_arg_assignment(self, arg, item, code):
        if arg.type.is_pyobject:
            # Python default arguments were already stored in 'item' at the very beginning
            if arg.type.is_builtin_type and arg.type.name in ('int', 'float'):
                arg.type.convert_to_basetype(code, arg.pos, item, arg.accept_none, arg.name_cstring)
            if arg.is_generic:
                item = PyrexTypes.typecast(arg.type, PyrexTypes.py_object_type, item)
            entry = arg.entry
            code.putln("%s = %s;" % (entry.cname, item))
        else:
            if arg.type.from_py_function:
                if arg.default:
                    # C-typed default arguments must be handled here
                    code.putln('if (%s) {' % item)
                code.putln(arg.type.from_py_call_code(
                    item, arg.entry.cname, arg.pos, code))
                if arg.default:
                    code.putln('} else {')
                    code.putln("%s = %s;" % (
                        arg.entry.cname,
                        arg.calculate_default_value_code(code)))
                    if arg.type.is_memoryviewslice:
                        code.put_var_incref_memoryviewslice(arg.entry, have_gil=True)
                    code.putln('}')
            else:
                error(arg.pos, "Cannot convert Python object argument to type '%s'" % arg.type)

    def generate_stararg_init_code(self, max_positional_args, code):
        # If the "**kwargs" parameter is unused, we keep it as NULL to avoid useless overhead.
        if self.starstar_arg and self.starstar_arg.entry.cf_used:
            self.starstar_arg.entry.xdecref_cleanup = 0
            code.putln('%s = PyDict_New(); if (unlikely(!%s)) return %s;' % (
                self.starstar_arg.entry.cname,
                self.starstar_arg.entry.cname,
                self.error_value()))
            code.put_var_gotref(self.starstar_arg.entry)
        if self.star_arg:
            self.star_arg.entry.xdecref_cleanup = 0
            if max_positional_args == 0:
                # If there are no positional arguments, use the args tuple
                # directly
                assert not self.signature.use_fastcall
                code.put_incref(Naming.args_cname, py_object_type)
                code.putln("%s = %s;" % (self.star_arg.entry.cname, Naming.args_cname))
            else:
                # It is possible that this is a slice of "negative" length,
                # as in args[5:3]. That's not a problem, the function below
                # handles that efficiently and returns the empty tuple.
                code.putln(
                    f'{self.star_arg.entry.cname} = __Pyx_ArgsSlice_{self.signature.fastvar}('
                    f'{Naming.args_cname}, {max_positional_args}, {Naming.nargs_cname}'
                    ');'
                )
                code.putln(
                    f"if (unlikely(!{self.star_arg.entry.type.nullcheck_string(self.star_arg.entry.cname)})) {{")
                if self.starstar_arg:
                    code.put_var_decref_clear(self.starstar_arg.entry)
                code.put_finish_refcount_context()
                code.putln(f'return {self.error_value()};')
                code.putln('}')
                code.put_var_gotref(self.star_arg.entry)

    def generate_argument_values_setup_code(self, args, code, decl_code):
        max_args = len(args)
        # the 'values' array collects references to arguments
        # before doing any type coercion etc.. Whether they are borrowed or not
        # depends on the compilation options.
        decl_code.putln("PyObject* values[%d] = {%s};" % (
            max_args, ','.join('0'*max_args)))

        if self.target.defaults_struct:
            code.putln('struct %s *%s = __Pyx_CyFunction_Defaults(struct %s, %s);' % (
                self.target.defaults_struct, Naming.dynamic_args_cname,
                self.target.defaults_struct, Naming.self_cname))

    def generate_argument_defaults_assignment_code(self, args, code):
        # Assign the default values to the empty entries of the 'values' array.
        for i, arg in enumerate(args):
            if arg.default and arg.type.is_pyobject:
                default_value = arg.calculate_default_value_code(code)
                code.putln(f'if (!values[{i}]) values[{i}] = __Pyx_NewRef({arg.type.as_pyobject(default_value)});')

    def generate_argument_values_cleanup_code(self, code):
        if not self.needs_values_cleanup:
            return

        loop_var = Naming.quick_temp_cname
        code.putln(f"for (Py_ssize_t {loop_var}=0; {loop_var} < (Py_ssize_t)(sizeof(values)/sizeof(values[0])); ++{loop_var}) {{")
        code.putln(f"Py_XDECREF(values[{loop_var}]);")
        code.putln("}")

    def generate_posargs_unpacking_code(self, min_positional_args, max_positional_args,
                                        has_fixed_positional_count,
                                        has_kw_only_args, all_args, argtuple_error_label, code):
        # First we count how many arguments must be passed as positional
        num_required_posonly_args = 0
        for arg in all_args:
            if arg.pos_only and not arg.default:
                num_required_posonly_args += 1

        # copy the values from the args tuple and check that it's not too long
        code.putln('switch (%s) {' % Naming.nargs_cname)
        if self.star_arg:
            code.putln('default:')

        for i in range(max_positional_args-1, num_required_posonly_args-1, -1):
            code.putln(f'case {i+1:2d}:')
            code.putln(f"values[{i}] = __Pyx_ArgRef_{self.signature.fastvar}({Naming.args_cname}, {i});")
            code.putln(f"if (!CYTHON_ASSUME_SAFE_MACROS && unlikely(!values[{i}])) {code.error_goto(self.pos)}")
            code.putln('CYTHON_FALLTHROUGH;')
        if num_required_posonly_args > 0:
            code.put(f'case {num_required_posonly_args:2d}: ')
            for i in range(num_required_posonly_args-1, -1, -1):
                code.putln(f"values[{i}] = __Pyx_ArgRef_{self.signature.fastvar}({Naming.args_cname}, {i});")
                code.putln(f"if (!CYTHON_ASSUME_SAFE_MACROS && unlikely(!values[{i}])) {code.error_goto(self.pos)}")
            code.putln('break;')
        for i in range(num_required_posonly_args-2, -1, -1):
            code.putln(f'case {i+1:2d}:')
            code.putln('CYTHON_FALLTHROUGH;')

        code.put('case  0: ')
        if num_required_posonly_args == 0:
            code.putln('break;')
        else:
            # catch-all for not enough pos-only args passed
            code.put_goto(argtuple_error_label)
        if not self.star_arg:
            code.put('default: ')  # more arguments than allowed
            code.put_goto(argtuple_error_label)
        code.putln('}')

    def generate_keyword_unpacking_code(self, max_positional_args, all_args, code):

        # ParseOptionalKeywords() needs to know how many of the arguments
        # that could be passed as keywords have in fact been passed as
        # positional args.

        # TODO: find out why this is sometimes different from 'self.num_posonly_args'.
        num_pos_only_args = 0
        for arg in all_args:
            if arg.pos_only:
                num_pos_only_args += 1

        if num_pos_only_args > 0:
            # There are positional-only arguments which we don't want to count,
            # since they cannot be keyword arguments.  Subtract the number of
            # pos-only arguments from the number of positional arguments we got.
            # If we get a negative number then none of the keyword arguments were
            # passed as positional args.
            code.putln('const Py_ssize_t kwd_pos_args = (unlikely(%s < %d)) ? 0 : %s - %d;' % (
                Naming.nargs_cname, num_pos_only_args,
                Naming.nargs_cname, num_pos_only_args,
            ))
        elif max_positional_args > 0:
            code.putln('const Py_ssize_t kwd_pos_args = %s;' % Naming.nargs_cname)

        if max_positional_args == 0:
            pos_arg_count = "0"
        elif self.star_arg:
            # If there is a *arg, the number of used positional args could be larger than
            # the number of possible keyword arguments.  But ParseOptionalKeywords() uses the
            # number of positional args as an index into the keyword argument name array,
            # if this is larger than the number of kwd args we get a segfault.  So round
            # this down to max_kwargs.
            max_kwargs = max_positional_args - num_pos_only_args
            code.putln(f"const Py_ssize_t used_pos_args = (kwd_pos_args < {max_kwargs}) ? kwd_pos_args : {max_kwargs};")
            pos_arg_count = "used_pos_args"
        else:
            pos_arg_count = "kwd_pos_args"

        if 0 < num_pos_only_args < len(all_args):
            values_array = f'values + {num_pos_only_args}'
        else:
            values_array = 'values'

        self_name_csafe = self.name.as_c_string_literal()

        code.globalstate.use_utility_code(
            UtilityCode.load_cached("ParseKeywords", "FunctionArguments.c"))
        code.put_error_if_neg(
            self.pos,
            f"__Pyx_ParseKeywords("
            f"{Naming.kwds_cname}, {Naming.kwvalues_cname}, {Naming.pykwdlist_cname}, "
            f"{self.starstar_arg.entry.cname if self.starstar_arg else '0'}, "
            f"{values_array}, "
            f"{pos_arg_count}, "
            f"{Naming.kwds_len_cname}, "
            f"{self_name_csafe}, "
            f"{self.starstar_arg is not None :d}"  # **kwargs might exist but be NULL in C if unused
            ")"
        )

    def generate_argument_conversion_code(self, code):
        # Generate code to convert arguments from signature type to
        # declared type, if needed.  Also copies signature arguments
        # into closure fields.
        for arg in self.args:
            if arg.needs_conversion:
                self.generate_arg_conversion(arg, code)

    def generate_arg_conversion(self, arg, code):
        # Generate conversion code for one argument.
        old_type = arg.hdr_type
        new_type = arg.type
        if old_type.is_pyobject:
            if arg.default:
                code.putln("if (%s) {" % arg.hdr_cname)
            else:
                code.putln("assert(%s); {" % arg.hdr_cname)
            self.generate_arg_conversion_from_pyobject(arg, code)
            code.putln("}")
        elif new_type.is_pyobject:
            self.generate_arg_conversion_to_pyobject(arg, code)
        else:
            if new_type.assignable_from(old_type):
                code.putln("%s = %s;" % (arg.entry.cname, arg.hdr_cname))
            else:
                error(arg.pos, "Cannot convert 1 argument from '%s' to '%s'" % (old_type, new_type))

    def generate_arg_conversion_from_pyobject(self, arg, code):
        new_type = arg.type
        # copied from CoerceFromPyTypeNode
        if new_type.from_py_function:
            code.putln(new_type.from_py_call_code(
                arg.hdr_cname,
                arg.entry.cname,
                arg.pos,
                code,
            ))
        else:
            error(arg.pos, "Cannot convert Python object argument to type '%s'" % new_type)

    def generate_arg_conversion_to_pyobject(self, arg, code):
        old_type = arg.hdr_type
        func = old_type.to_py_function
        if func:
            code.putln("%s = %s(%s); %s" % (
                arg.entry.cname,
                func,
                arg.hdr_cname,
                code.error_goto_if_null(arg.entry.cname, arg.pos)))
            code.put_var_gotref(arg.entry)
        else:
            error(arg.pos, "Cannot convert argument of type '%s' to Python object" % old_type)

    def generate_argument_type_tests(self, code):
        # Generate type tests for args whose signature
        # type is PyObject * and whose declared type is
        # a subtype thereof.
        for arg in self.args:
            if arg.needs_type_test:
                self.generate_arg_type_test(arg, code)
            elif not arg.accept_none and (arg.type.is_pyobject or
                                          arg.type.is_buffer or
                                          arg.type.is_memoryviewslice):
                self.generate_arg_none_check(arg, code)

        if self.target.entry.is_special:
            for n in reversed(range(len(self.args), self.signature.max_num_fixed_args())):
                # For special functions with optional args (e.g. power which can
                # take 2 or 3 args), unused args are None since this is what the
                # compilers sets. This is probably not more than one argument.
                code.putln(f"if (unlikely(unused_arg_{n:d} != Py_None)) {{")
                code.putln(
                    'PyErr_Format(PyExc_TypeError, "%.200s() takes %zd arguments but %zd were given",'
                    f' (const char*) {self.target.entry.qualified_name.as_c_string_literal()},'
                    f' (Py_ssize_t) {self.signature.max_num_fixed_args()},'
                    f' (Py_ssize_t) {n:d}'
                    f'); {code.error_goto(self.pos)}'
                )
                code.putln("}")

    def error_value(self):
        return self.signature.error_value


class GeneratorDefNode(DefNode):
    # Generator function node that creates a new generator instance when called.
    #
    # gbody          GeneratorBodyDefNode   the function implementing the generator
    #

    is_generator = True
    is_iterable_coroutine = False
    gen_type_name = 'Generator'
    needs_closure = True

    child_attrs = DefNode.child_attrs + ["gbody"]

    def __init__(self, pos, **kwargs):
        # XXX: don't actually needs a body
        kwargs['body'] = StatListNode(pos, stats=[], is_terminator=True)
        super().__init__(pos, **kwargs)

    def analyse_declarations(self, env):
        super().analyse_declarations(env)
        self.gbody.local_scope = self.local_scope
        self.gbody.analyse_declarations(env)

    def generate_function_body(self, env, code):
        body_cname = self.gbody.entry.func_cname
        name = code.intern_identifier(self.name)
        qualname = code.intern_identifier(self.qualname)
        module_name = code.intern_identifier(self.module_name)

        self.code_object.generate_result_code(code)

        code.putln('{')
        code.putln(
            f'__pyx_CoroutineObject *gen = __Pyx_{self.gen_type_name}_New('
            f'(__pyx_coroutine_body_t) {body_cname},'
            f' {self.code_object.py_result()},'
            f' (PyObject *) {Naming.cur_scope_cname},'
            f' {name}, {qualname}, {module_name}'
            f'); {code.error_goto_if_null("gen", self.pos)}'
        )

        code.put_decref(Naming.cur_scope_cname, py_object_type)
        if self.requires_classobj:
            classobj_cname = 'gen->classobj'
            code.putln('%s = __Pyx_CyFunction_GetClassObj(%s);' % (
                classobj_cname, Naming.self_cname))
            code.put_incref(classobj_cname, py_object_type)
            code.put_giveref(classobj_cname, py_object_type)
        code.put_finish_refcount_context()
        code.putln('return (PyObject *) gen;')
        code.putln('}')

    def generate_function_definitions(self, env, code):
        env.use_utility_code(UtilityCode.load_cached(self.gen_type_name, "Coroutine.c"))
        self.gbody.generate_function_header(code, proto=True)
        super().generate_function_definitions(env, code)
        self.gbody.generate_function_definitions(env, code)


class AsyncDefNode(GeneratorDefNode):
    gen_type_name = 'Coroutine'
    is_coroutine = True


class IterableAsyncDefNode(AsyncDefNode):
    gen_type_name = 'IterableCoroutine'
    is_iterable_coroutine = True


class AsyncGenNode(AsyncDefNode):
    gen_type_name = 'AsyncGen'
    is_asyncgen = True


class GeneratorBodyDefNode(DefNode):
    # Main code body of a generator implemented as a DefNode.
    #

    is_generator_body = True
    is_inlined = False
    is_coroutine_body = False
    is_async_gen_body = False
    inlined_comprehension_type = None  # container type for inlined comprehensions

    def __init__(self, pos=None, name=None, body=None, is_coroutine_body=False, is_async_gen_body=False):
        super().__init__(
            pos=pos, body=body, name=name,
            is_coroutine_body=is_coroutine_body,
            is_async_gen_body=is_async_gen_body,
            doc=None, args=[], star_arg=None, starstar_arg=None)

    def declare_generator_body(self, env):
        prefix = env.next_id(env.scope_prefix)
        name = env.next_id('generator')
        cname = Naming.genbody_prefix + prefix + name
        entry = env.declare_var(None, py_object_type, self.pos,
                                cname=cname, visibility='private')
        entry.func_cname = cname
        entry.qualified_name = EncodedString(self.name)
        # Work-around for https://github.com/cython/cython/issues/1699
        # We don't currently determine whether the generator entry is used or not,
        # so mark it as used to avoid false warnings.
        entry.used = True
        self.entry = entry

    def analyse_declarations(self, env):
        self.analyse_argument_types(env)
        self.declare_generator_body(env)

    def generate_function_header(self, code, proto=False):
        header = "static PyObject *%s(__pyx_CoroutineObject *%s, CYTHON_UNUSED PyThreadState *%s, PyObject *%s)" % (
            self.entry.func_cname,
            Naming.generator_cname,
            Naming.local_tstate_cname,
            Naming.sent_value_cname)
        if proto:
            code.putln('%s; /* proto */' % header)
        else:
            code.putln('%s /* generator body */\n{' % header)

    def generate_function_definitions(self, env, code):
        lenv = self.local_scope

        # Generate closure function definitions
        self.body.generate_function_definitions(lenv, code)

        # Generate C code for header and body of function
        code.enter_cfunc_scope(lenv)
        code.return_from_error_cleanup_label = code.new_label()

        # ----- Top-level constants used by this function
        code.mark_pos(self.pos)
        self.generate_cached_builtins_decls(lenv, code)
        # ----- Function header
        code.putln("")
        self.generate_function_header(code)
        closure_init_code = code.insertion_point()
        # ----- Local variables
        code.putln("PyObject *%s = NULL;" % Naming.retval_cname)
        tempvardecl_code = code.insertion_point()
        code.put_declare_refcount_context()
        code.put_setup_refcount_context(self.entry.name or self.entry.qualified_name)
        tracing = code.is_tracing()
        if tracing:
            tempvardecl_code.put_trace_declarations(is_generator=True)
            code.funcstate.can_trace = True

        self.code_object.generate_result_code(code)

        # ----- Resume switch point.
        code.funcstate.init_closure_temps(lenv.scope_class.type.scope)
        resume_code = code.insertion_point()
        first_run_label = code.new_label('first_run')
        code.use_label(first_run_label)
        code.put_label(first_run_label)

        if tracing:
            # TODO: report .throw() if 'sent_value' == NULL (?)
            assert code.funcstate.gil_owned
            code.put_trace_start(self.entry.qualified_name, self.pos, is_generator=True)

        if self.is_inlined:
            code.putln(code.error_goto_if_null(Naming.sent_value_cname, self.pos))
        else:
            code.putln(f"if (unlikely({Naming.sent_value_cname} != Py_None)) {{")
            if self.is_async_gen_body:
                coro_type = "async generator"
            elif self.is_coroutine_body:
                coro_type = "coroutine"
            else:
                coro_type = "generator"
            code.putln(
                f"if (unlikely({Naming.sent_value_cname})) "
                f'''PyErr_SetString(PyExc_TypeError, "can't send non-None value to a just-started {coro_type}");'''
            )
            code.putln(code.error_goto(self.pos))
            code.putln("}")

        # ----- prepare target container for inlined comprehension
        if self.is_inlined and self.inlined_comprehension_type is not None:
            target_type = self.inlined_comprehension_type
            if target_type is Builtin.list_type:
                comp_init = 'PyList_New(0)'
            elif target_type is Builtin.set_type:
                comp_init = 'PySet_New(NULL)'
            elif target_type is Builtin.dict_type:
                comp_init = 'PyDict_New()'
            else:
                raise InternalError(
                    "invalid type of inlined comprehension: %s" % target_type)
            code.putln("%s = %s; %s" % (
                Naming.retval_cname, comp_init,
                code.error_goto_if_null(Naming.retval_cname, self.pos)))
            code.put_gotref(Naming.retval_cname, py_object_type)

        # ----- Function body
        self.generate_function_body(env, code)
        # ----- Closure initialization
        if lenv.scope_class.type.scope.var_entries:
            closure_init_code.putln('%s = %s;' % (
                lenv.scope_class.type.declaration_code(Naming.cur_scope_cname),
                lenv.scope_class.type.cast_code('%s->closure' %
                                                Naming.generator_cname)))
            # FIXME: this silences a potential "unused" warning => try to avoid unused closures in more cases
            code.putln("CYTHON_MAYBE_UNUSED_VAR(%s);" % Naming.cur_scope_cname)

        if tracing and not self.body.is_terminator:
            code.funcstate.can_trace = False
            code.put_trace_return("Py_None", pos=self.pos)
            #code.put_trace_stopiteration(self.pos, "Py_None")

        code.mark_pos(self.pos)
        code.putln("")
        code.putln("/* function exit code */")

        # on normal generator termination, we do not take the exception propagation
        # path: no traceback info is required and not creating it is much faster
        if not self.is_inlined and not self.body.is_terminator:
            #if tracing:
            #    code.put_trace_stopiteration(self.pos, "Py_None")
            code.put_init_to_py_none(Naming.retval_cname, py_object_type)

        # ----- Error cleanup
        if code.label_used(code.error_label):
            if not self.body.is_terminator:
                code.put_goto(code.return_label)
            code.put_label(code.error_label)
            if self.is_inlined and self.inlined_comprehension_type is not None:
                code.put_xdecref_clear(Naming.retval_cname, py_object_type)

            for cname, type in code.funcstate.all_managed_temps():
                code.put_xdecref(cname, type)
            code.putln("if (__Pyx_PyErr_Occurred()) {")  # we allow exit without GeneratorExit / StopIteration
            if tracing:
                code.put_trace_exception_propagating()
            if Future.generator_stop in env.context.future_directives:
                # PEP 479: turn accidental StopIteration exceptions into a RuntimeError
                code.globalstate.use_utility_code(UtilityCode.load_cached("pep479", "Coroutine.c"))
                code.putln("__Pyx_Generator_Replace_StopIteration(%d);" % bool(self.is_async_gen_body))
            code.put_add_traceback(self.entry.qualified_name)
            if tracing:
                code.put_trace_unwind(self.pos)
            code.putln("}")

        # ----- Non-error return cleanup
        code.put_label(code.return_label)
        code.put_xgiveref(Naming.retval_cname, py_object_type)
        if tracing:
            code.put_trace_exit()

        # For Py3.7, clearing is already done below.
        code.putln("#if !CYTHON_USE_EXC_INFO_STACK")
        code.putln("__Pyx_Coroutine_ResetAndClearException(%s);" % Naming.generator_cname)
        code.putln("#endif")
        code.putln('%s->resume_label = -1;' % Naming.generator_cname)
        # clean up as early as possible to help breaking any reference cycles
        code.putln('__Pyx_Coroutine_clear((PyObject*)%s);' % Naming.generator_cname)
        code.put_finish_refcount_context()
        code.putln("return %s;" % Naming.retval_cname)
        code.putln("}")

        # ----- Go back and insert temp variable declarations
        tempvardecl_code.put_temp_declarations(code.funcstate)
        # ----- Generator resume code
        resume_code.putln("switch (%s->resume_label) {" % (
                       Naming.generator_cname))

        resume_code.putln("case 0: goto %s;" % first_run_label)

        for i, label in code.yield_labels:
            resume_code.putln("case %d: goto %s;" % (i, label))
        resume_code.putln("default: /* CPython raises the right error here */")
        if tracing:
            resume_code.put_trace_start(self.entry.qualified_name, self.pos, is_generator=True)
            resume_code.put_trace_return("Py_None", pos=self.pos)
        resume_code.put_finish_refcount_context()
        resume_code.putln("return NULL;")
        resume_code.putln("}")

        code.exit_cfunc_scope()


class OverrideCheckNode(StatNode):
    # A Node for dispatching to the def method if it
    # is overridden.
    #
    #  py_func
    #
    #  args
    #  func_temp
    #  body

    child_attrs = ['body']

    body = None

    def analyse_expressions(self, env):
        self.args = env.arg_entries
        if self.py_func.is_module_scope:
            first_arg = 0
        else:
            first_arg = 1
        from . import ExprNodes
        self.func_node = ExprNodes.RawCNameExprNode(self.pos, py_object_type)
        call_node = ExprNodes.SimpleCallNode(
            self.pos, function=self.func_node,
            args=[ExprNodes.NameNode(self.pos, name=arg.name)
                  for arg in self.args[first_arg:]])
        if env.return_type.is_void or env.return_type.is_returncode:
            self.body = StatListNode(self.pos, stats=[
                ExprStatNode(self.pos, expr=call_node),
                ReturnStatNode(self.pos, value=None)])
        else:
            self.body = ReturnStatNode(self.pos, value=call_node)
        self.body = self.body.analyse_expressions(env)
        return self

    def generate_execution_code(self, code):
        # For fused functions, look up the dispatch function, not the specialisation.
        method_entry = self.py_func.fused_py_func.entry if self.py_func.fused_py_func else self.py_func.entry
        interned_attr_cname = code.intern_identifier(method_entry.name)

        # Check to see if we are an extension type
        if self.py_func.is_module_scope:
            self_arg = "((PyObject *)%s)" % Naming.module_cname
        else:
            self_arg = "((PyObject *)%s)" % self.args[0].cname
        code.putln("/* Check if called by wrapper */")
        code.putln("if (unlikely(%s)) ;" % Naming.skip_dispatch_cname)
        code.putln("/* Check if overridden in Python */")
        if self.py_func.is_module_scope or self.py_func.entry.scope.lookup_here("__dict__"):
            code.putln("else {")
        else:
            code.putln("else if (")
            code.putln("#if !CYTHON_USE_TYPE_SLOTS")
            # If CYTHON_USE_TYPE_SPECS then all extension types are heap-types so the check below automatically
            # passes and thus takes the slow route.
            # Therefore we do a less thorough check - if the type hasn't changed then clearly it hasn't
            # been overridden, and if the type isn't GC then it also won't have been overridden.
            typeptr_cname = code.name_in_module_state(self.py_func.entry.scope.parent_type.typeptr_cname)
            code.putln(f"unlikely(Py_TYPE({self_arg}) != "
                        f"{typeptr_cname} &&")
            code.putln(f"__Pyx_PyType_HasFeature(Py_TYPE({self_arg}), Py_TPFLAGS_HAVE_GC))")
            code.putln("#else")
            code.putln(f"unlikely(Py_TYPE({self_arg})->tp_dictoffset != 0 || "
                       f"__Pyx_PyType_HasFeature(Py_TYPE({self_arg}), (Py_TPFLAGS_IS_ABSTRACT | Py_TPFLAGS_HEAPTYPE)))")
            code.putln("#endif")
            code.putln(") {")

        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP && CYTHON_USE_TYPE_SLOTS")
        code.globalstate.use_utility_code(
            UtilityCode.load_cached("PyDictVersioning", "ObjectHandling.c"))
        # TODO: remove the object dict version check by 'inlining' the getattr implementation for methods.
        # This would allow checking the dict versions around _PyType_Lookup() if it returns a descriptor,
        # and would (tada!) make this check a pure type based thing instead of supporting only a single
        # instance at a time.
        code.putln("static PY_UINT64_T %s = __PYX_DICT_VERSION_INIT, %s = __PYX_DICT_VERSION_INIT;" % (
            Naming.tp_dict_version_temp, Naming.obj_dict_version_temp))
        code.putln("if (unlikely(!__Pyx_object_dict_version_matches(%s, %s, %s))) {" % (
            self_arg, Naming.tp_dict_version_temp, Naming.obj_dict_version_temp))
        code.putln("PY_UINT64_T %s = __Pyx_get_tp_dict_version(%s);" % (
            Naming.type_dict_guard_temp, self_arg))
        code.putln("#endif")

        func_node_temp = code.funcstate.allocate_temp(py_object_type, manage_ref=True)
        self.func_node.set_cname(func_node_temp)
        # need to get attribute manually--scope would return cdef method
        code.globalstate.use_utility_code(
            UtilityCode.load_cached("PyObjectGetAttrStr", "ObjectHandling.c"))
        code.putln("%s = __Pyx_PyObject_GetAttrStr(%s, %s); %s" % (
            func_node_temp, self_arg, interned_attr_cname,
            code.error_goto_if_null(func_node_temp, self.pos)))
        code.put_gotref(func_node_temp, py_object_type)

        code.putln("if (!__Pyx_IsSameCFunction(%s, (void(*)(void)) %s)) {" % (func_node_temp, method_entry.func_cname))
        self.body.generate_execution_code(code)
        code.putln("}")

        # NOTE: it's not 100% sure that we catch the exact versions here that were used for the lookup,
        # but it is very unlikely that the versions change during lookup, and the type dict safe guard
        # should increase the chance of detecting such a case.
        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP && CYTHON_USE_TYPE_SLOTS")
        code.putln("%s = __Pyx_get_tp_dict_version(%s);" % (
            Naming.tp_dict_version_temp, self_arg))
        code.putln("%s = __Pyx_get_object_dict_version(%s);" % (
            Naming.obj_dict_version_temp, self_arg))
        # Safety check that the type dict didn't change during the lookup.  Since CPython looks up the
        # attribute (descriptor) first in the type dict and then in the instance dict or through the
        # descriptor, the only really far-away lookup when we get here is one in the type dict. So we
        # double check the type dict version before and afterwards to guard against later changes of
        # the type dict during the lookup process.
        code.putln("if (unlikely(%s != %s)) {" % (
            Naming.type_dict_guard_temp, Naming.tp_dict_version_temp))
        code.putln("%s = %s = __PYX_DICT_VERSION_INIT;" % (
            Naming.tp_dict_version_temp, Naming.obj_dict_version_temp))
        code.putln("}")
        code.putln("#endif")

        code.put_decref_clear(func_node_temp, PyrexTypes.py_object_type)
        code.funcstate.release_temp(func_node_temp)

        code.putln("#if CYTHON_USE_DICT_VERSIONS && CYTHON_USE_PYTYPE_LOOKUP && CYTHON_USE_TYPE_SLOTS")
        code.putln("}")
        code.putln("#endif")

        code.putln("}")


class ClassDefNode(StatNode, BlockNode):
    pass


class PyClassDefNode(ClassDefNode):
    #  A Python class definition.
    #
    #  name     EncodedString   Name of the class
    #  doc      string or None  The class docstring
    #  body     StatNode        Attribute definition code
    #  entry    Symtab.Entry
    #  scope    PyClassScope
    #  decorators    [DecoratorNode]        list of decorators or None
    #  bases    ExprNode        Expression that evaluates to a tuple of base classes
    #
    #  The following subnodes are constructed internally:
    #
    #  doc_node NameNode   '__doc__' name that is made available to the class body
    #  dict     DictNode   Class dictionary or Py3 namespace
    #  classobj ClassNode  Class object
    #  target   NameNode   Variable to assign class object to
    #  orig_bases  None or ExprNode  "bases" before transformation by PEP560 __mro_entries__,
    #                                used to create the __orig_bases__ attribute

    child_attrs = ["doc_node", "body", "dict", "metaclass", "mkw", "bases", "class_result",
                   "target", "class_cell", "decorators", "orig_bases"]
    decorators = None
    class_result = None
    is_py3_style_class = False  # Python3 style class (kwargs)
    metaclass = None
    mkw = None
    doc_node = None
    orig_bases = None

    def __init__(self, pos, name, bases, doc, body, decorators=None,
                 keyword_args=None, force_py3_semantics=False):
        StatNode.__init__(self, pos)
        self.name = name
        self.doc = doc
        self.body = body
        self.decorators = decorators
        self.bases = bases
        from . import ExprNodes
        if self.doc and Options.docstrings:
            doc = embed_position(self.pos, self.doc)
            doc_node = ExprNodes.UnicodeNode(pos, value=doc)
            self.doc_node = ExprNodes.NameNode(name=EncodedString('__doc__'), type=py_object_type, pos=pos)
        else:
            doc_node = None

        allow_py2_metaclass = not force_py3_semantics
        if keyword_args:
            allow_py2_metaclass = False
            self.is_py3_style_class = True
            if keyword_args.is_dict_literal:
                if keyword_args.key_value_pairs:
                    for i, item in list(enumerate(keyword_args.key_value_pairs))[::-1]:
                        if item.key.value == 'metaclass':
                            if self.metaclass is not None:
                                error(item.pos, "keyword argument 'metaclass' passed multiple times")
                            # special case: we already know the metaclass,
                            # so we don't need to do the "build kwargs,
                            # find metaclass" dance at runtime
                            self.metaclass = item.value
                            del keyword_args.key_value_pairs[i]
                    self.mkw = keyword_args
                else:
                    assert self.metaclass is not None
            else:
                # MergedDictNode
                self.mkw = ExprNodes.ProxyNode(keyword_args)

        if force_py3_semantics or self.bases or self.mkw or self.metaclass:
            if self.metaclass is None:
                if keyword_args and not keyword_args.is_dict_literal:
                    # **kwargs may contain 'metaclass' arg
                    mkdict = self.mkw
                else:
                    mkdict = None
                if (not mkdict and
                        self.bases.is_sequence_constructor and
                        not self.bases.args):
                    pass  # no base classes => no inherited metaclass
                else:
                    self.metaclass = ExprNodes.PyClassMetaclassNode(
                        pos, class_def_node=self)
                needs_metaclass_calculation = False
            else:
                needs_metaclass_calculation = True

            self.dict = ExprNodes.PyClassNamespaceNode(
                pos, name=name, doc=doc_node, class_def_node=self)
            self.classobj = ExprNodes.Py3ClassNode(
                pos, name=name, class_def_node=self, doc=doc_node,
                calculate_metaclass=needs_metaclass_calculation,
                allow_py2_metaclass=allow_py2_metaclass,
                force_type=force_py3_semantics,
            )
        else:
            # no bases, no metaclass => old style class creation
            self.dict = ExprNodes.DictNode(pos, key_value_pairs=[])
            self.classobj = ExprNodes.ClassNode(
                pos, name=name, class_def_node=self, doc=doc_node)

        self.target = ExprNodes.NameNode(pos, name=name)
        self.class_cell = ExprNodes.ClassCellInjectorNode(self.pos)

    def as_cclass(self):
        """
        Return this node as if it were declared as an extension class
        """
        if self.is_py3_style_class:
            error(self.classobj.pos, "Python3 style class could not be represented as C class")
            return

        from . import ExprNodes
        return CClassDefNode(self.pos,
                             visibility='private',
                             module_name=None,
                             class_name=self.name,
                             bases=self.bases or ExprNodes.TupleNode(self.pos, args=[]),
                             decorators=self.decorators,
                             body=self.body,
                             in_pxd=False,
                             doc=self.doc)

    def create_scope(self, env):
        genv = env
        while genv.is_py_class_scope or genv.is_c_class_scope:
            genv = genv.outer_scope
        cenv = self.scope = PyClassScope(name=self.name, outer_scope=genv)
        return cenv

    def analyse_declarations(self, env):
        unwrapped_class_result = class_result = self.classobj
        if self.decorators:
            from .ExprNodes import SimpleCallNode
            for decorator in self.decorators[::-1]:
                class_result = SimpleCallNode(
                    decorator.pos,
                    function=decorator.decorator,
                    args=[class_result])
            self.decorators = None
        self.class_result = class_result
        if self.bases:
            self.bases.analyse_declarations(env)
        if self.mkw:
            self.mkw.analyse_declarations(env)
        self.class_result.analyse_declarations(env)
        self.target.analyse_target_declaration(env)
        cenv = self.create_scope(env)
        cenv.directives = env.directives
        cenv.class_obj_cname = self.target.entry.cname
        if self.doc_node:
            self.doc_node.analyse_target_declaration(cenv)
        self.body.analyse_declarations(cenv)
        unwrapped_class_result.analyse_annotations(cenv)

    update_bases_functype = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
            PyrexTypes.CFuncTypeArg("bases",  PyrexTypes.py_object_type, None)
        ])

    def analyse_expressions(self, env):
        if self.bases and not (self.bases.is_sequence_constructor and len(self.bases.args) == 0):
            from .ExprNodes import PythonCapiCallNode, CloneNode
            # handle the Python 3.7 __mro_entries__ transformation
            orig_bases = self.bases.analyse_expressions(env)
            self.bases = PythonCapiCallNode(orig_bases.pos,
                function_name="__Pyx_PEP560_update_bases",
                func_type=self.update_bases_functype,
                utility_code=UtilityCode.load_cached('Py3UpdateBases', 'ObjectHandling.c'),
                args=[CloneNode(orig_bases)])
            self.orig_bases = orig_bases
        if self.bases:
            self.bases = self.bases.analyse_expressions(env)
        if self.mkw:
            self.mkw = self.mkw.analyse_expressions(env)
        if self.metaclass:
            self.metaclass = self.metaclass.analyse_expressions(env)
        self.dict = self.dict.analyse_expressions(env)
        self.class_result = self.class_result.analyse_expressions(env)
        cenv = self.scope
        self.body = self.body.analyse_expressions(cenv)
        self.target = self.target.analyse_target_expression(env, self.classobj)
        self.class_cell = self.class_cell.analyse_expressions(cenv)
        return self

    def generate_function_definitions(self, env, code):
        self.generate_lambda_definitions(self.scope, code)
        self.body.generate_function_definitions(self.scope, code)

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        code.pyclass_stack.append(self)
        cenv = self.scope
        if self.orig_bases:
            self.orig_bases.generate_evaluation_code(code)
        if self.bases:
            self.bases.generate_evaluation_code(code)
        if self.mkw:
            self.mkw.generate_evaluation_code(code)
        if self.metaclass:
            self.metaclass.generate_evaluation_code(code)
        self.dict.generate_evaluation_code(code)
        if self.orig_bases:
            # update __orig_bases__ if needed
            code.putln("if (%s != %s) {" % (self.bases.result(), self.orig_bases.result()))
            code.putln(
                code.error_goto_if_neg('PyDict_SetItemString(%s, "__orig_bases__", %s)' % (
                    self.dict.result(), self.orig_bases.result()),
                    self.pos
            ))
            code.putln("}")
            self.orig_bases.generate_disposal_code(code)
            self.orig_bases.free_temps(code)
        cenv.namespace_cname = cenv.class_obj_cname = self.dict.result()

        class_cell = self.class_cell
        if class_cell is not None and not class_cell.is_active:
            class_cell = None

        if class_cell is not None:
            class_cell.generate_evaluation_code(code)
        self.body.generate_execution_code(code)
        self.class_result.generate_evaluation_code(code)
        if class_cell is not None:
            class_cell.generate_injection_code(
                code, self.class_result.result())
        if class_cell is not None:
            class_cell.generate_disposal_code(code)
            class_cell.free_temps(code)

        cenv.namespace_cname = cenv.class_obj_cname = self.classobj.result()
        self.target.generate_assignment_code(self.class_result, code)
        self.dict.generate_disposal_code(code)
        self.dict.free_temps(code)
        if self.metaclass:
            self.metaclass.generate_disposal_code(code)
            self.metaclass.free_temps(code)
        if self.mkw:
            self.mkw.generate_disposal_code(code)
            self.mkw.free_temps(code)
        if self.bases:
            self.bases.generate_disposal_code(code)
            self.bases.free_temps(code)
        code.pyclass_stack.pop()


class CClassDefNode(ClassDefNode):
    #  An extension type definition.
    #
    #  visibility         'private' or 'public' or 'extern'
    #  typedef_flag       boolean
    #  api                boolean
    #  module_name        string or None    For import of extern type objects
    #  class_name         string            Unqualified name of class
    #  as_name            string or None    Name to declare as in this scope
    #  bases              TupleNode         Base class(es)
    #  objstruct_name     string or None    Specified C name of object struct
    #  typeobj_name       string or None    Specified C name of type object
    #  check_size         'warn', 'error', 'ignore'     What to do if tp_basicsize does not match
    #  in_pxd             boolean           Is in a .pxd file
    #  decorators         [DecoratorNode]   list of decorators or None
    #  doc                string or None
    #  body               StatNode or None
    #  entry              Symtab.Entry
    #  base_type          PyExtensionType or None
    #  buffer_defaults_node DictNode or None Declares defaults for a buffer
    #  buffer_defaults_pos

    child_attrs = ["body"]
    buffer_defaults_node = None
    buffer_defaults_pos = None
    typedef_flag = False
    api = False
    objstruct_name = None
    typeobj_name = None
    check_size = None
    decorators = None
    shadow = False

    @property
    def punycode_class_name(self):
        return punycodify_name(self.class_name)

    def buffer_defaults(self, env):
        if not hasattr(self, '_buffer_defaults'):
            from . import Buffer
            if self.buffer_defaults_node:
                self._buffer_defaults = Buffer.analyse_buffer_options(
                    self.buffer_defaults_pos,
                    env, [], self.buffer_defaults_node,
                    need_complete=False)
            else:
                self._buffer_defaults = None
        return self._buffer_defaults

    def declare(self, env):
        if self.module_name and self.visibility != 'extern':
            module_path = self.module_name.split(".")
            home_scope = env.find_imported_module(module_path, self.pos)
            if not home_scope:
                return None
        else:
            home_scope = env

        self.entry = home_scope.declare_c_class(
            name=self.class_name,
            pos=self.pos,
            defining=0,
            implementing=0,
            module_name=self.module_name,
            base_type=None,
            objstruct_cname=self.objstruct_name,
            typeobj_cname=self.typeobj_name,
            visibility=self.visibility,
            typedef_flag=self.typedef_flag,
            check_size = self.check_size,
            api=self.api,
            buffer_defaults=self.buffer_defaults(env),
            shadow=self.shadow)
        if self.bases and len(self.bases.args) > 1:
            self.entry.type.multiple_bases = True

    def _handle_cclass_decorators(self, env):
        extra_directives = {}
        if not self.decorators:
            return extra_directives

        from . import ExprNodes

        remaining_decorators = []

        for original_decorator in self.decorators:
            decorator = original_decorator.decorator
            # entries aren't set at this point, so unfortunately we can't just do
            #  decorator.get_known_standard_library_import().
            # Instead we have to manually look it up
            decorator_call = None
            if isinstance(decorator, ExprNodes.CallNode):
                decorator_call = decorator
                decorator = decorator.function
            known_name = Builtin.exprnode_to_known_standard_library_name(decorator, env)
            if known_name == 'functools.total_ordering':
                if decorator_call:
                    error(decorator_call.pos, "total_ordering cannot be called.")
                extra_directives["total_ordering"] = True
                continue
            elif known_name == "dataclasses.dataclass":
                args = None
                kwds = {}
                if decorator_call:
                    if isinstance(decorator_call, ExprNodes.SimpleCallNode):
                        args = decorator_call.args
                    else:
                        args = decorator_call.positional_args.args
                        kwds_ = decorator_call.keyword_args
                        if kwds_:
                            kwds = kwds_.as_python_dict()
                extra_directives[known_name] = (args, kwds)
                continue
            remaining_decorators.append(original_decorator)
        if remaining_decorators:
            error(remaining_decorators[0].pos, "Cdef functions/classes cannot take arbitrary decorators.")
        self.decorators = remaining_decorators
        return extra_directives

    def analyse_declarations(self, env):
        #print "CClassDefNode.analyse_declarations:", self.class_name
        #print "...visibility =", self.visibility
        #print "...module_name =", self.module_name

        if env.in_cinclude and not self.objstruct_name:
            error(self.pos, "Object struct name specification required for C class defined in 'extern from' block")
        extra_directives = self._handle_cclass_decorators(env)
        self.base_type = None
        # Now that module imports are cached, we need to
        # import the modules for extern classes.
        if self.module_name:
            self.module = None
            for module in env.cimported_modules:
                if module.name == self.module_name:
                    self.module = module
            if self.module is None:
                self.module = ModuleScope(self.module_name, None, env.context)
                self.module.has_extern_class = 1
                env.add_imported_module(self.module)

        if self.bases.args:
            base = self.bases.args[0]
            base_type = base.analyse_as_type(env)

            # If we accidentally picked the C type of the same name, use the Python rather than the C variant.
            # We need to go through a local lookup since the builtin names might be redefined by user code.
            if base_type is PyrexTypes.c_int_type:
                base_type = env.lookup('int').type
            elif base_type is PyrexTypes.c_float_type:
                base_type = env.lookup('float').type
            elif base_type is PyrexTypes.c_double_complex_type:
                base_type = env.lookup('complex').type

            if base_type is None:
                error(base.pos, "First base of '%s' is not an extension type" % self.class_name)
            elif base_type is py_object_type:
                base_class_scope = None
            elif not base_type.is_extension_type and \
                     not (base_type.is_builtin_type and base_type.objstruct_cname):
                error(base.pos, "'%s' is not an extension type" % base_type)
            elif not base_type.is_complete():
                error(base.pos, "Base class '%s' of type '%s' is incomplete" % (
                    base_type.name, self.class_name))
            elif base_type.scope and base_type.scope.directives and \
                     base_type.is_final_type:
                error(base.pos, "Base class '%s' of type '%s' is final" % (
                    base_type, self.class_name))
            elif base_type.is_builtin_type and \
                     base_type.name in ('tuple', 'bytes'):
                error(base.pos, "inheritance from PyVarObject types like '%s' is not currently supported"
                      % base_type.name)
            else:
                self.base_type = base_type

            if env.directives.get('freelist', 0) > 0 and base_type != PyrexTypes.py_object_type:
                warning(self.pos, "freelists cannot be used on subtypes, only the base class can manage them", 1)

        has_body = self.body is not None
        if has_body and self.base_type and not self.base_type.scope:
            # To properly initialize inherited attributes, the base type must
            # be analysed before this type.
            self.base_type.defered_declarations.append(lambda : self.analyse_declarations(env))
            return

        if self.module_name and self.visibility != 'extern':
            module_path = self.module_name.split(".")
            home_scope = env.find_imported_module(module_path, self.pos)
            if not home_scope:
                return
        else:
            home_scope = env

        if self.visibility == 'extern':
            if (self.module_name == '__builtin__' and
                    self.class_name in Builtin.builtin_types and
                    env.qualified_name[:8] != 'cpython.'):  # allow overloaded names for cimporting from cpython
                warning(self.pos, "%s already a builtin Cython type" % self.class_name, 1)

        self.entry = home_scope.declare_c_class(
            name=self.class_name,
            pos=self.pos,
            defining=has_body and self.in_pxd,
            implementing=has_body and not self.in_pxd,
            module_name=self.module_name,
            base_type=self.base_type,
            objstruct_cname=self.objstruct_name,
            typeobj_cname=self.typeobj_name,
            check_size=self.check_size,
            visibility=self.visibility,
            typedef_flag=self.typedef_flag,
            api=self.api,
            buffer_defaults=self.buffer_defaults(env),
            shadow=self.shadow)
        if self.bases and len(self.bases.args) > 1:
            self.entry.type.multiple_bases = True

        if self.shadow:
            home_scope.lookup(self.class_name).as_variable = self.entry
        if home_scope is not env and self.visibility == 'extern':
            env.add_imported_entry(self.class_name, self.entry, self.pos)
        self.scope = scope = self.entry.type.scope
        if scope is not None:
            if extra_directives:
                scope.directives = env.directives.copy()
                scope.directives.update(extra_directives)
            else:
                scope.directives = env.directives
            if "dataclasses.dataclass" in scope.directives:
                is_frozen = False
                # Retrieve the @dataclass config (args, kwargs), as passed into the decorator.
                dataclass_config = scope.directives["dataclasses.dataclass"]
                if dataclass_config:
                    decorator_kwargs = dataclass_config[1]
                    frozen_flag = decorator_kwargs.get('frozen')
                    is_frozen = frozen_flag and frozen_flag.is_literal and frozen_flag.value
                scope.is_c_dataclass_scope = "frozen" if is_frozen else True

        if self.doc and Options.docstrings:
            scope.doc = embed_position(self.pos, self.doc)

        if has_body:
            self.body.analyse_declarations(scope)
            dict_entry = self.scope.lookup_here("__dict__")
            if dict_entry and dict_entry.is_variable and (not scope.defined and not scope.implemented):
                dict_entry.getter_cname = self.scope.mangle_internal("__dict__getter")
                self.scope.declare_property("__dict__", dict_entry.doc, dict_entry.pos)
            if self.in_pxd:
                scope.defined = 1
            else:
                scope.implemented = 1

        if len(self.bases.args) > 1:
            if not has_body or self.in_pxd:
                error(self.bases.args[1].pos, "Only declare first base in declaration.")
            # At runtime, we check that the other bases are heap types
            # and that a __dict__ is added if required.
            for other_base in self.bases.args[1:]:
                if other_base.analyse_as_type(env):
                    error(other_base.pos, "Only one extension type base class allowed.")
            self.entry.type.early_init = 0
            from . import ExprNodes
            self.type_init_args = ExprNodes.TupleNode(
                self.pos,
                args=[ExprNodes.IdentifierStringNode(self.pos, value=self.class_name),
                      self.bases,
                      ExprNodes.DictNode(self.pos, key_value_pairs=[])])
        elif self.base_type:
            self.entry.type.early_init = self.base_type.is_external or self.base_type.early_init
            self.type_init_args = None
        else:
            self.entry.type.early_init = 1
            self.type_init_args = None

        env.allocate_vtable_names(self.entry)

        for thunk in self.entry.type.defered_declarations:
            thunk()

    def analyse_expressions(self, env):
        if self.body:
            scope = self.entry.type.scope
            self.body = self.body.analyse_expressions(scope)
        if self.type_init_args:
            self.type_init_args.analyse_expressions(env)
        return self

    def generate_function_definitions(self, env, code):
        if self.body:
            self.generate_lambda_definitions(self.scope, code)
            self.body.generate_function_definitions(self.scope, code)

    def generate_execution_code(self, code):
        # This is needed to generate evaluation code for
        # default values of method arguments.
        code.mark_pos(self.pos)
        if not self.entry.type.early_init:
            bases = None
            if self.type_init_args:
                # Extract bases tuple and validate 'best base' by actually calling 'type()'.
                bases = code.funcstate.allocate_temp(PyrexTypes.py_object_type, manage_ref=True)

                self.type_init_args.generate_evaluation_code(code)
                code.putln("%s = __Pyx_PyTuple_GET_ITEM(%s, 1);" % (bases, self.type_init_args.result()))
                code.putln(code.error_goto_if(f"!CYTHON_ASSUME_SAFE_MACROS && !{bases}", self.pos))
                code.put_incref(bases, PyrexTypes.py_object_type)

                first_base = code.funcstate.allocate_temp(Builtin.type_type, manage_ref=False)
                code.putln(f"{first_base} = ((PyTypeObject*)__Pyx_PyTuple_GET_ITEM({bases}, 0));")
                code.putln(code.error_goto_if(f"!CYTHON_ASSUME_SAFE_MACROS && !{first_base}", self.pos))

                # Let Python do the base types compatibility checking.
                trial_type = code.funcstate.allocate_temp(PyrexTypes.py_object_type, manage_ref=True)
                # __Pyx_PyType_GetSlot doesn't work on non-heap types in Limited API < 3.10 so awful manual fallback:
                code.putln("#if CYTHON_COMPILING_IN_LIMITED_API && __PYX_LIMITED_VERSION_HEX < 0x030A0000")
                code.putln("if (__Pyx_get_runtime_version() < 0x030A0000) {")
                type_new = code.funcstate.allocate_temp(PyrexTypes.py_object_type, manage_ref=True)
                code.putln(f'{type_new} = PyObject_GetAttrString((PyObject*)&PyType_Type, "__new__");')
                code.putln(code.error_goto_if_null(type_new, self.pos))
                code.put_gotref(type_new, py_object_type)
                type_tuple = code.funcstate.allocate_temp(PyrexTypes.py_object_type, manage_ref=True)
                code.putln(f"{type_tuple} = PyTuple_Pack(1, (PyObject*)&PyType_Type);")
                code.putln(code.error_goto_if_null(type_tuple, self.pos))
                code.put_gotref(type_tuple, py_object_type)
                args_tuple = code.funcstate.allocate_temp(PyrexTypes.py_object_type, manage_ref=True)
                code.putln(f"{args_tuple} = PyNumber_Add({type_tuple}, {self.type_init_args.result()});")
                code.putln(code.error_goto_if_null(args_tuple, self.pos))
                code.put_gotref(args_tuple, py_object_type)
                code.putln(f'{trial_type} = PyObject_Call({type_new}, {args_tuple}, NULL);')
                for temp in [type_new, type_tuple, args_tuple]:
                    code.put_decref_clear(temp, PyrexTypes.py_object_type)
                    code.funcstate.release_temp(temp)
                code.putln("} else")
                code.putln("#endif")
                code.putln("%s = __Pyx_PyType_GetSlot(&PyType_Type, tp_new, newfunc)(&PyType_Type, %s, NULL);" % (
                    trial_type, self.type_init_args.result()))
                code.putln(code.error_goto_if_null(trial_type, self.pos))
                code.put_gotref(trial_type, py_object_type)
                code.putln("if (__Pyx_PyType_GetSlot((PyTypeObject*) %s, tp_base, PyTypeObject*) != %s) {" % (
                    trial_type, first_base))
                # trial_type is a heaptype so GetSlot works in all versions of the limited API
                trial_type_base = "__Pyx_PyType_GetSlot((PyTypeObject*) %s, tp_base, PyTypeObject*)" % trial_type
                code.putln("__Pyx_TypeName base_name = __Pyx_PyType_GetFullyQualifiedName(%s);" % trial_type_base)
                code.putln("__Pyx_TypeName type_name = __Pyx_PyType_GetFullyQualifiedName(%s);" % first_base)
                code.putln("PyErr_Format(PyExc_TypeError, "
                    "\"best base '\" __Pyx_FMT_TYPENAME \"' must be equal to first base '\" __Pyx_FMT_TYPENAME \"'\",")
                code.putln("             base_name, type_name);")
                code.putln("__Pyx_DECREF_TypeName(base_name);")
                code.putln("__Pyx_DECREF_TypeName(type_name);")
                code.putln(code.error_goto(self.pos))
                code.putln("}")

                code.putln(f"{first_base} = NULL;")  # borrowed so no decref
                code.funcstate.release_temp(first_base)

                code.put_decref_clear(trial_type, PyrexTypes.py_object_type)
                code.funcstate.release_temp(trial_type)

                self.type_init_args.generate_disposal_code(code)
                self.type_init_args.free_temps(code)

            self.generate_type_ready_code(self.entry, code, bases_tuple_cname=bases, check_heap_type_bases=True)
            if bases is not None:
                code.put_decref_clear(bases, PyrexTypes.py_object_type)
                code.funcstate.release_temp(bases)

        if self.body:
            self.body.generate_execution_code(code)

    # Also called from ModuleNode for early init types.
    @staticmethod
    def generate_type_ready_code(entry, code, bases_tuple_cname=None, check_heap_type_bases=False):
        # Generate a call to PyType_Ready for an extension
        # type defined in this module.
        type = entry.type
        typeptr_cname = f"{Naming.modulestatevalue_cname}->{type.typeptr_cname}"
        scope = type.scope
        if not scope:  # could be None if there was an error
            return
        if entry.visibility == 'extern':
            # Generate code to initialise the typeptr of an external extension
            # type defined in this module to point to its type object.
            if type.typeobj_cname:
                # FIXME: this should not normally be set :-?
                assert not type.typeobj_cname
                code.putln("%s = &%s;" % (
                    type.typeptr_cname,
                    type.typeobj_cname,
                ))
            return
        # TODO: remove 'else:' and dedent
        else:
            assert typeptr_cname
            assert type.typeobj_cname
            typespec_cname = "%s_spec" % type.typeobj_cname
            code.putln("#if CYTHON_USE_TYPE_SPECS")
            tuple_temp = None
            if not bases_tuple_cname and scope.parent_type.base_type:
                tuple_temp = code.funcstate.allocate_temp(py_object_type, manage_ref=True)
                code.putln("%s = PyTuple_Pack(1, (PyObject *)%s); %s" % (
                    tuple_temp,
                    code.typeptr_cname_in_module_state(scope.parent_type.base_type),
                    code.error_goto_if_null(tuple_temp, entry.pos),
                ))
                code.put_gotref(tuple_temp, py_object_type)

            if bases_tuple_cname or tuple_temp:
                if check_heap_type_bases:
                    code.globalstate.use_utility_code(
                        UtilityCode.load_cached('ValidateBasesTuple', 'ExtensionTypes.c'))
                    code.put_error_if_neg(entry.pos, "__Pyx_validate_bases_tuple(%s.name, %s, %s)" % (
                        typespec_cname,
                        TypeSlots.get_slot_by_name("tp_dictoffset", scope.directives).slot_code(scope),
                        bases_tuple_cname or tuple_temp,
                    ))

                code.putln("%s = (PyTypeObject *) __Pyx_PyType_FromModuleAndSpec(%s, &%s, %s);" % (
                    typeptr_cname,
                    Naming.module_cname,
                    typespec_cname,
                    bases_tuple_cname or tuple_temp,
                ))
                if tuple_temp:
                    code.put_xdecref_clear(tuple_temp, type=py_object_type)
                    code.funcstate.release_temp(tuple_temp)
                code.putln(code.error_goto_if_null(typeptr_cname, entry.pos))
            else:
                code.putln(
                    "%s = (PyTypeObject *) __Pyx_PyType_FromModuleAndSpec(%s, &%s, NULL); %s" % (
                        typeptr_cname,
                        Naming.module_cname,
                        typespec_cname,
                        code.error_goto_if_null(typeptr_cname, entry.pos),
                    ))

            # The buffer interface is not currently supported by PyType_FromSpec().
            buffer_slot = TypeSlots.get_slot_by_name("tp_as_buffer", code.globalstate.directives)
            if not buffer_slot.is_empty(scope):
                code.putln("#if !CYTHON_COMPILING_IN_LIMITED_API")
                code.putln("%s->%s = %s;" % (
                    typeptr_cname,
                    buffer_slot.slot_name,
                    buffer_slot.slot_code(scope),
                ))
                # Still need to inherit buffer methods since PyType_Ready() didn't do it for us.
                for buffer_method_name in ("__getbuffer__", "__releasebuffer__"):
                    buffer_slot = TypeSlots.get_slot_table(
                        code.globalstate.directives).get_slot_by_method_name(buffer_method_name)
                    if buffer_slot.slot_code(scope) == "0" and not TypeSlots.get_base_slot_function(scope, buffer_slot):
                        code.putln("if (!%s->tp_as_buffer->%s &&"
                                   " %s->tp_base->tp_as_buffer &&"
                                   " %s->tp_base->tp_as_buffer->%s) {" % (
                            typeptr_cname, buffer_slot.slot_name,
                            typeptr_cname,
                            typeptr_cname, buffer_slot.slot_name,
                        ))
                        code.putln("%s->tp_as_buffer->%s = %s->tp_base->tp_as_buffer->%s;" % (
                            typeptr_cname, buffer_slot.slot_name,
                            typeptr_cname, buffer_slot.slot_name,
                        ))
                        code.putln("}")
                code.putln("#elif defined(Py_bf_getbuffer) && defined(Py_bf_releasebuffer)")
                code.putln("/* PY_VERSION_HEX >= 0x03090000 || Py_LIMITED_API >= 0x030B0000 */")
                code.putln("#elif defined(_MSC_VER)")
                code.putln("#pragma message (\"The buffer protocol is not supported in the Limited C-API < 3.11.\")")
                code.putln("#else")
                code.putln("#warning \"The buffer protocol is not supported in the Limited C-API < 3.11.\"")
                code.putln("#endif")

            code.globalstate.use_utility_code(
                UtilityCode.load_cached("FixUpExtensionType", "ExtensionTypes.c"))
            code.put_error_if_neg(entry.pos, "__Pyx_fix_up_extension_type_from_spec(&%s, %s)" % (
                typespec_cname, typeptr_cname))

            code.putln("#else")
            if bases_tuple_cname:
                code.put_incref(bases_tuple_cname, py_object_type)
                code.put_giveref(bases_tuple_cname, py_object_type)
                code.putln("%s.tp_bases = %s;" % (type.typeobj_cname, bases_tuple_cname))
            code.putln("%s = &%s;" % (
                typeptr_cname,
                type.typeobj_cname,
            ))
            code.putln("#endif")  # if CYTHON_USE_TYPE_SPECS

            base_type = type.base_type
            while base_type:
                if base_type.is_external and base_type.objstruct_cname != "PyTypeObject":
                    # 'type' is special-cased because it is actually based on PyHeapTypeObject
                    # Variable length bases are allowed if the current class doesn't grow
                    code.putln("if (sizeof(%s%s) != sizeof(%s%s)) {" % (
                        "" if type.typedef_flag else "struct ", type.objstruct_cname,
                        "" if base_type.typedef_flag else "struct ", base_type.objstruct_cname))
                    code.globalstate.use_utility_code(
                        UtilityCode.load_cached("ValidateExternBase", "ExtensionTypes.c"))
                    base_typeptr_cname = code.typeptr_cname_in_module_state(type.base_type)
                    code.put_error_if_neg(entry.pos, "__Pyx_validate_extern_base(%s)" % (
                        base_typeptr_cname))
                    code.putln("}")
                    break
                base_type = base_type.base_type

            code.putln("#if !CYTHON_COMPILING_IN_LIMITED_API")
            # FIXME: these still need to get initialised even with the limited-API
            for slot in TypeSlots.get_slot_table(code.globalstate.directives):
                slot.generate_dynamic_init_code(scope, code)
            code.putln("#endif")

            code.putln("#if !CYTHON_USE_TYPE_SPECS")
            code.globalstate.use_utility_code(
                UtilityCode.load_cached('PyType_Ready', 'ExtensionTypes.c'))
            code.put_error_if_neg(entry.pos, "__Pyx_PyType_Ready(%s)" % typeptr_cname)
            code.putln("#endif")
            code.put_make_object_deferred(f"(PyObject*){typeptr_cname}")

            # Use specialised attribute lookup for types with generic lookup but no instance dict.
            getattr_slot_func = TypeSlots.get_slot_code_by_name(scope, 'tp_getattro')
            dictoffset_slot_func = TypeSlots.get_slot_code_by_name(scope, 'tp_dictoffset')
            if getattr_slot_func == '0' and dictoffset_slot_func == '0':
                code.putln("#if !CYTHON_COMPILING_IN_LIMITED_API")  # FIXME

                code.putln("if ((CYTHON_USE_TYPE_SLOTS && CYTHON_USE_PYTYPE_LOOKUP) &&"
                           " likely(!%s->tp_dictoffset && %s->tp_getattro == PyObject_GenericGetAttr)) {" % (
                    typeptr_cname, typeptr_cname))
                code.putln("%s->tp_getattro = PyObject_GenericGetAttr;" %
                    typeptr_cname)
                code.putln("}")
                code.putln("#endif")  # if !CYTHON_COMPILING_IN_LIMITED_API

            # Fix special method docstrings. This is a bit of a hack, but
            # unless we let PyType_Ready create the slot wrappers we have
            # a significant performance hit. (See trac #561.)
            for func in entry.type.scope.pyfunc_entries:
                is_buffer = func.name in ('__getbuffer__', '__releasebuffer__')
                if (func.is_special and Options.docstrings and
                        func.wrapperbase_cname and not is_buffer):
                    slot = TypeSlots.get_slot_table(
                        entry.type.scope.directives).get_slot_by_method_name(func.name)
                    preprocessor_guard = slot.preprocessor_guard_code() if slot else None
                    if preprocessor_guard:
                        code.putln(preprocessor_guard)
                    code.putln('#if CYTHON_UPDATE_DESCRIPTOR_DOC')
                    code.putln("{")
                    code.putln(
                        'PyObject *wrapper = PyObject_GetAttrString((PyObject *)%s, "%s"); %s' % (
                            typeptr_cname,
                            func.name,
                            code.error_goto_if_null('wrapper', entry.pos)))
                    code.putln(
                        "if (__Pyx_IS_TYPE(wrapper, &PyWrapperDescr_Type)) {")
                    code.putln(
                        "%s = *((PyWrapperDescrObject *)wrapper)->d_base;" % (
                            func.wrapperbase_cname))
                    code.putln(
                        "%s.doc = %s;" % (func.wrapperbase_cname, func.doc_cname))
                    code.putln(
                        "((PyWrapperDescrObject *)wrapper)->d_base = &%s;" % (
                            func.wrapperbase_cname))
                    code.putln("}")
                    code.putln("}")
                    code.putln('#endif')
                    if preprocessor_guard:
                        code.putln('#endif')

            if type.vtable_cname:
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached('SetVTable', 'ImportExport.c'))
                code.put_error_if_neg(entry.pos, "__Pyx_SetVtable(%s, %s)" % (
                    typeptr_cname,
                    type.vtabptr_cname,
                ))
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached('MergeVTables', 'ImportExport.c'))
                code.put_error_if_neg(entry.pos, "__Pyx_MergeVtables(%s)" % typeptr_cname)
            if not type.scope.is_internal and not type.scope.directives.get('internal'):
                # scope.is_internal is set for types defined by
                # Cython (such as closures), the 'internal'
                # directive is set by users
                code.put_error_if_neg(entry.pos, "PyObject_SetAttr(%s, %s, (PyObject *) %s)" % (
                    Naming.module_cname,
                    code.intern_identifier(scope.class_name),
                    typeptr_cname,
                ))

            weakref_entry = scope.lookup_here("__weakref__") if not scope.is_closure_class_scope else None
            if weakref_entry:
                if weakref_entry.type is py_object_type:
                    tp_weaklistoffset = "%s->tp_weaklistoffset" % typeptr_cname
                    if type.typedef_flag:
                        objstruct = type.objstruct_cname
                    else:
                        objstruct = "struct %s" % type.objstruct_cname
                    code.putln("#if CYTHON_USE_TYPE_SLOTS")
                    code.putln("if (%s == 0) %s = offsetof(%s, %s);" % (
                        tp_weaklistoffset,
                        tp_weaklistoffset,
                        objstruct,
                        weakref_entry.cname))
                    code.putln("#endif")
                else:
                    error(weakref_entry.pos, "__weakref__ slot must be of type 'object'")

            if scope.lookup_here("__reduce_cython__") if not scope.is_closure_class_scope else None:
                # Unfortunately, we cannot reliably detect whether a
                # superclass defined __reduce__ at compile time, so we must
                # do so at runtime.
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached('SetupReduce', 'ExtensionTypes.c'))
                code.put_error_if_neg(entry.pos, "__Pyx_setup_reduce((PyObject *) %s)" % typeptr_cname)

    def annotate(self, code):
        if self.type_init_args:
            self.type_init_args.annotate(code)
        if self.body:
            self.body.annotate(code)


class PropertyNode(StatNode):
    #  Definition of a property in an extension type.
    #
    #  name   string
    #  doc    EncodedString or None    Doc string
    #  entry  Symtab.Entry             The Entry of the property attribute
    #  body   StatListNode

    child_attrs = ["body"]

    def analyse_declarations(self, env):
        self.entry = env.declare_property(self.name, self.doc, self.pos)
        self.body.analyse_declarations(self.entry.scope)

    def analyse_expressions(self, env):
        self.body = self.body.analyse_expressions(env)
        return self

    def generate_function_definitions(self, env, code):
        self.body.generate_function_definitions(env, code)

    def generate_execution_code(self, code):
        pass

    def annotate(self, code):
        self.body.annotate(code)


class CPropertyNode(StatNode):
    """Definition of a C property, backed by a CFuncDefNode getter.
    """
    #  name   string
    #  doc    EncodedString or None        Doc string of the property
    #  entry  Symtab.Entry                 The Entry of the property attribute
    #  body   StatListNode[CFuncDefNode]   (for compatibility with PropertyNode)

    child_attrs = ["body"]
    is_cproperty = True

    @property
    def cfunc(self):
        stats = self.body.stats
        assert stats and isinstance(stats[0], CFuncDefNode), stats
        return stats[0]

    def analyse_declarations(self, env):
        scope = PropertyScope(self.name, class_scope=env)
        self.body.analyse_declarations(scope)
        entry = self.entry = env.declare_property(
            self.name, self.doc, self.pos, ctype=self.cfunc.return_type, property_scope=scope)
        entry.getter_cname = self.cfunc.entry.cname

    def analyse_expressions(self, env):
        self.body = self.body.analyse_expressions(env)
        return self

    def generate_function_definitions(self, env, code):
        self.body.generate_function_definitions(env, code)

    def generate_execution_code(self, code):
        pass

    def annotate(self, code):
        self.body.annotate(code)


class GlobalNode(StatNode):
    # Global variable declaration.
    #
    # names    [string]

    child_attrs = []

    def analyse_declarations(self, env):
        for name in self.names:
            env.declare_global(name, self.pos)

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        pass


class NonlocalNode(StatNode):
    # Nonlocal variable declaration via the 'nonlocal' keyword.
    #
    # names    [string]

    child_attrs = []

    def analyse_declarations(self, env):
        for name in self.names:
            env.declare_nonlocal(name, self.pos)

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        pass


class ExprStatNode(StatNode):
    #  Expression used as a statement.
    #
    #  expr   ExprNode

    child_attrs = ["expr"]

    def analyse_declarations(self, env):
        from . import ExprNodes
        expr = self.expr
        if isinstance(expr, ExprNodes.GeneralCallNode):
            func = expr.function.as_cython_attribute()
            if func == 'declare':
                args, kwds = expr.explicit_args_kwds()
                if len(args):
                    error(expr.pos, "Variable names must be specified.")
                for var, type_node in kwds.key_value_pairs:
                    type = type_node.analyse_as_type(env)
                    if type is None:
                        error(type_node.pos, "Unknown type")
                    else:
                        env.declare_var(var.value, type, var.pos, is_cdef=True)
                self.__class__ = PassStatNode
        elif getattr(expr, 'annotation', None) is not None:
            if expr.is_name:
                # non-code variable annotation, e.g. "name: type"
                expr.declare_from_annotation(env)
                self.__class__ = PassStatNode
            elif expr.is_attribute or expr.is_subscript:
                # unused expression with annotation, e.g. "a[0]: type" or "a.xyz : type"
                self.__class__ = PassStatNode

    def analyse_expressions(self, env):
        self.expr.result_is_used = False  # hint that .result() may safely be left empty
        self.expr = self.expr.analyse_expressions(env)
        # Repeat in case of node replacement.
        self.expr.result_is_used = False  # hint that .result() may safely be left empty
        return self

    def nogil_check(self, env):
        if self.expr.type.is_pyobject and self.expr.result_in_temp():
            self.gil_error()

    gil_message = "Discarding owned Python object"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        self.expr.result_is_used = False  # hint that .result() may safely be left empty
        self.expr.generate_evaluation_code(code)
        if not self.expr.result_in_temp() and self.expr.result():
            result = self.expr.result()
            if not self.expr.type.is_void:
                result = "(void)(%s)" % result
            code.putln("%s;" % result)
        self.expr.generate_disposal_code(code)
        self.expr.free_temps(code)

    def generate_function_definitions(self, env, code):
        self.expr.generate_function_definitions(env, code)

    def annotate(self, code):
        self.expr.annotate(code)


class AssignmentNode(StatNode):
    #  Abstract base class for assignment nodes.
    #
    #  The analyse_expressions and generate_execution_code
    #  phases of assignments are split into two sub-phases
    #  each, to enable all the right hand sides of a
    #  parallel assignment to be evaluated before assigning
    #  to any of the left hand sides.

    def _warn_on_const_assignment(self, lhs, rhs):
        rhs_t = rhs.type
        lhs_t = lhs.type
        if rhs_t.is_ptr and rhs_t.base_type.is_const and lhs_t.is_ptr and not lhs_t.base_type.is_const:
            warning(self.pos, "Assigning to '{}' from '{}' discards const qualifier".format(lhs_t, rhs_t), level=1)

    def _check_const_assignment(self, node):
        if isinstance(node, AssignmentNode):
            self._warn_on_const_assignment(node.lhs, node.rhs)

    def analyse_expressions(self, env):
        node = self.analyse_types(env)
        self._check_const_assignment(node)
        if isinstance(node, AssignmentNode) and not isinstance(node, ParallelAssignmentNode):
            if node.rhs.type.is_unowned_view and node.rhs.is_ephemeral():
                error(self.pos, "Storing unsafe C derivative of temporary Python reference")
        return node

#       def analyse_expressions(self, env):
#           self.analyse_expressions_1(env)
#           self.analyse_expressions_2(env)

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        self.generate_rhs_evaluation_code(code)
        self.generate_assignment_code(code)


class SingleAssignmentNode(AssignmentNode):
    #  The simplest case:
    #
    #    a = b
    #
    #  lhs                      ExprNode      Left hand side
    #  rhs                      ExprNode      Right hand side
    #  first                    bool          Is this guaranteed the first assignment to lhs?
    #  is_overloaded_assignment bool          Is this assignment done via an overloaded operator=
    #  is_assignment_expression bool          Internally SingleAssignmentNode is used to implement assignment expressions
    #  from_pxd_cvardef         bool          Was created from a CVarDef node in a pxd file
    #  exception_check
    #  exception_value

    child_attrs = ["lhs", "rhs"]
    first = False
    is_overloaded_assignment = False
    is_assignment_expression = False
    declaration_only = False
    from_pxd_cvardef = False

    def analyse_declarations(self, env):
        from . import ExprNodes

        # handle declarations of the form x = cython.foo()
        if isinstance(self.rhs, ExprNodes.CallNode):
            func_name = self.rhs.function.as_cython_attribute()
            if func_name:
                args, kwds = self.rhs.explicit_args_kwds()
                if func_name in ['declare', 'typedef']:
                    if len(args) > 2:
                        error(args[2].pos, "Invalid positional argument.")
                        return
                    if kwds is not None:
                        kwdict = kwds.compile_time_value(None)
                        if func_name == 'typedef' or 'visibility' not in kwdict:
                            error(kwds.pos, "Invalid keyword argument.")
                            return
                        visibility = kwdict['visibility']
                    else:
                        visibility = 'private'
                    type = args[0].analyse_as_type(env)
                    if type is None:
                        error(args[0].pos, "Unknown type")
                        return
                    lhs = self.lhs
                    if func_name == 'declare':
                        if isinstance(lhs, ExprNodes.NameNode):
                            vars = [(lhs.name, lhs.pos)]
                        elif isinstance(lhs, ExprNodes.TupleNode):
                            vars = [(var.name, var.pos) for var in lhs.args]
                        else:
                            error(lhs.pos, "Invalid declaration")
                            return
                        for var, pos in vars:
                            env.declare_var(var, type, pos, is_cdef=True, visibility=visibility)
                        if len(args) == 2:
                            # we have a value
                            self.rhs = args[1]
                        else:
                            self.declaration_only = True
                    else:
                        self.declaration_only = True
                        if not isinstance(lhs, ExprNodes.NameNode):
                            error(lhs.pos, "Invalid declaration.")
                        env.declare_typedef(lhs.name, type, self.pos, visibility='private')

                elif func_name in ['struct', 'union']:
                    self.declaration_only = True
                    if len(args) > 0 or kwds is None:
                        error(self.rhs.pos, "Struct or union members must be given by name.")
                        return
                    members = []
                    for member, type_node in kwds.key_value_pairs:
                        type = type_node.analyse_as_type(env)
                        if type is None:
                            error(type_node.pos, "Unknown type")
                        else:
                            members.append((member.value, type, member.pos))
                    if len(members) < len(kwds.key_value_pairs):
                        return
                    if not isinstance(self.lhs, ExprNodes.NameNode):
                        error(self.lhs.pos, "Invalid declaration.")
                    name = self.lhs.name
                    scope = StructOrUnionScope(name)
                    env.declare_struct_or_union(name, func_name, scope, False, self.rhs.pos)
                    for member, type, pos in members:
                        scope.declare_var(member, type, pos)

                elif func_name == 'fused_type':
                    # dtype = cython.fused_type(...)
                    self.declaration_only = True
                    if kwds:
                        error(self.rhs.function.pos,
                              "fused_type does not take keyword arguments")

                    fusednode = FusedTypeNode(self.rhs.pos,
                                              name=self.lhs.name, types=args)
                    fusednode.analyse_declarations(env)

        if self.declaration_only:
            return
        else:
            if self.is_assignment_expression:
                self.lhs.analyse_assignment_expression_target_declaration(env)
            else:
                self.lhs.analyse_target_declaration(env)
                # if an entry doesn't exist that just implies that lhs isn't made up purely
                # of AttributeNodes and NameNodes - it isn't useful as a known path to
                # a standard library module
                if (self.lhs.is_attribute or self.lhs.is_name) and self.lhs.entry and not self.lhs.entry.known_standard_library_import:
                    stdlib_import_name = self.rhs.get_known_standard_library_import()
                    if stdlib_import_name:
                        self.lhs.entry.known_standard_library_import = stdlib_import_name

    def analyse_types(self, env, use_temp=0):
        from . import ExprNodes

        self.rhs = self.rhs.analyse_types(env)

        if self.lhs.is_name and self.lhs.entry.type.is_const:
            if env.is_module_scope and self.lhs.entry.init is None and self.rhs.has_constant_result():
                self.lhs.entry.init = self.rhs.constant_result
            else:
                error(self.pos, f"Assignment to const '{self.lhs.name}'")

        unrolled_assignment = self.unroll_rhs(env)
        if unrolled_assignment:
            return unrolled_assignment

        self.lhs = self.lhs.analyse_target_types(env)
        self.lhs.gil_assignment_check(env)
        unrolled_assignment = self.unroll_lhs(env)
        if unrolled_assignment:
            return unrolled_assignment

        if isinstance(self.lhs, ExprNodes.MemoryViewIndexNode):
            self.lhs.analyse_broadcast_operation(self.rhs)
            self.lhs = self.lhs.analyse_as_memview_scalar_assignment(self.rhs)
        elif self.lhs.type.is_array:
            if not isinstance(self.lhs, ExprNodes.SliceIndexNode):
                # cannot assign to C array, only to its full slice
                lhs = ExprNodes.SliceIndexNode(self.lhs.pos, base=self.lhs, start=None, stop=None)
                self.lhs = lhs.analyse_target_types(env)

        if self.lhs.type.is_cpp_class:
            op = env.lookup_operator_for_types(self.pos, '=', [self.lhs.type, self.rhs.type])
            if op:
                rhs = self.rhs
                self.is_overloaded_assignment = True
                self.exception_check = op.type.exception_check
                self.exception_value = op.type.exception_value
                if self.exception_check == '+' and self.exception_value is None:
                    env.use_utility_code(UtilityCode.load_cached("CppExceptionConversion", "CppSupport.cpp"))
            else:
                rhs = self.rhs.coerce_to(self.lhs.type, env)
        else:
            rhs = self.rhs.coerce_to(self.lhs.type, env)

        if use_temp or rhs.is_attribute or (
                not rhs.is_name and not rhs.is_literal and
                rhs.type.is_pyobject):
            # things like (cdef) attribute access are not safe (traverses pointers)
            rhs = rhs.coerce_to_temp(env)
        elif rhs.type.is_pyobject:
            rhs = rhs.coerce_to_simple(env)
        self.rhs = rhs

        if self.from_pxd_cvardef and not self.lhs.type.is_const:
            warning(
                self.pos,
                "Assignment in pxd file will not be executed. Suggest declaring as const.",
                2
            )

        return self

    def unroll(self, node, target_size, env):
        from . import ExprNodes, UtilNodes

        base = node
        start_node = stop_node = step_node = check_node = None

        if node.type.is_ctuple:
            slice_size = node.type.size

        elif node.type.is_ptr or node.type.is_array:
            while isinstance(node, ExprNodes.SliceIndexNode) and not (node.start or node.stop):
                base = node = node.base
            if isinstance(node, ExprNodes.SliceIndexNode):
                base = node.base
                start_node = node.start
                if start_node:
                    start_node = start_node.coerce_to(PyrexTypes.c_py_ssize_t_type, env)
                stop_node = node.stop
                if stop_node:
                    stop_node = stop_node.coerce_to(PyrexTypes.c_py_ssize_t_type, env)
                else:
                    if node.type.is_array and node.type.size:
                        stop_node = ExprNodes.IntNode(
                            self.pos, value=str(node.type.size),
                            constant_result=(node.type.size if isinstance(node.type.size, int)
                                             else ExprNodes.constant_value_not_set))
                    else:
                        error(self.pos, "C array iteration requires known end index")
                        return
                if step_node:
                    step_node = step_node.coerce_to(PyrexTypes.c_py_ssize_t_type, env)

                # TODO: Factor out SliceIndexNode.generate_slice_guard_code() for use here.
                def get_const(node, none_value):
                    if node is None:
                        return none_value
                    elif node.has_constant_result():
                        return node.constant_result
                    else:
                        raise ValueError("Not a constant.")

                try:
                    slice_size = (get_const(stop_node, None) - get_const(start_node, 0)) / get_const(step_node, 1)
                except ValueError:
                    error(self.pos, "C array assignment currently requires known endpoints")
                    return

            elif node.type.is_array:
                slice_size = node.type.size
                if not isinstance(slice_size, int):
                    return  # might still work when coercing to Python
            else:
                return

        else:
            return

        if slice_size != target_size:
            error(self.pos, "Assignment to/from slice of wrong length, expected %s, got %s" % (
                slice_size, target_size))
            return

        items = []
        base = UtilNodes.LetRefNode(base)
        refs = [base]
        if start_node and not start_node.is_literal:
            start_node = UtilNodes.LetRefNode(start_node)
            refs.append(start_node)
        if stop_node and not stop_node.is_literal:
            stop_node = UtilNodes.LetRefNode(stop_node)
            refs.append(stop_node)
        if step_node and not step_node.is_literal:
            step_node = UtilNodes.LetRefNode(step_node)
            refs.append(step_node)

        for ix in range(target_size):
            ix_node = ExprNodes.IntNode.for_size(self.pos, ix)
            if step_node is not None:
                if isinstance(step_node.constant_result, int):
                    step_value = ix_node.constant_result * step_node.constant_result
                    ix_node = ExprNodes.IntNode.for_size(self.pos, step_value)
                else:
                    ix_node = ExprNodes.MulNode(self.pos, operator='*', operand1=step_node, operand2=ix_node)
            if start_node is not None:
                if isinstance(start_node.constant_result, int) and ix_node.has_constant_result():
                    index_value = ix_node.constant_result + start_node.constant_result
                    ix_node = ExprNodes.IntNode.for_size(self.pos, index_value)
                else:
                    ix_node = ExprNodes.AddNode(
                        self.pos, operator='+', operand1=start_node, operand2=ix_node)
            items.append(ExprNodes.IndexNode(self.pos, base=base, index=ix_node.analyse_types(env)))
        return check_node, refs, items

    def unroll_assignments(self, refs, check_node, lhs_list, rhs_list, env):
        from . import UtilNodes
        assignments = []
        for lhs, rhs in zip(lhs_list, rhs_list):
            assignments.append(SingleAssignmentNode(self.pos, lhs=lhs, rhs=rhs, first=self.first))
        node = ParallelAssignmentNode(pos=self.pos, stats=assignments).analyse_expressions(env)
        if check_node:
            node = StatListNode(pos=self.pos, stats=[check_node, node])
        for ref in refs[::-1]:
            node = UtilNodes.LetNode(ref, node)
        return node

    def unroll_rhs(self, env):
        from . import ExprNodes
        if not isinstance(self.lhs, ExprNodes.TupleNode):
            return
        if any(arg.is_starred for arg in self.lhs.args):
            return

        unrolled = self.unroll(self.rhs, len(self.lhs.args), env)
        if not unrolled:
            return
        check_node, refs, rhs = unrolled
        return self.unroll_assignments(refs, check_node, self.lhs.args, rhs, env)

    def unroll_lhs(self, env):
        if self.lhs.type.is_ctuple:
            # Handled directly.
            return
        from . import ExprNodes
        if not isinstance(self.rhs, ExprNodes.TupleNode):
            return

        unrolled = self.unroll(self.lhs, len(self.rhs.args), env)
        if not unrolled:
            return
        check_node, refs, lhs = unrolled
        return self.unroll_assignments(refs, check_node, lhs, self.rhs.args, env)

    def generate_rhs_evaluation_code(self, code):
        self.rhs.generate_evaluation_code(code)

    def generate_assignment_code(self, code, overloaded_assignment=False):
        if self.is_overloaded_assignment:
            self.lhs.generate_assignment_code(
                self.rhs,
                code,
                overloaded_assignment=self.is_overloaded_assignment,
                exception_check=self.exception_check,
                exception_value=self.exception_value)
        else:
            self.lhs.generate_assignment_code(self.rhs, code)

    def generate_function_definitions(self, env, code):
        self.rhs.generate_function_definitions(env, code)

    def annotate(self, code):
        self.lhs.annotate(code)
        self.rhs.annotate(code)


class CascadedAssignmentNode(AssignmentNode):
    #  An assignment with multiple left hand sides:
    #
    #    a = b = c
    #
    #  lhs_list   [ExprNode]   Left hand sides
    #  rhs        ExprNode     Right hand sides
    #
    #  Used internally:
    #
    #  coerced_values       [ExprNode]   RHS coerced to all distinct LHS types
    #  cloned_values        [ExprNode]   cloned RHS value for each LHS
    #  assignment_overloads [Bool]       If each assignment uses a C++ operator=

    child_attrs = ["lhs_list", "rhs", "coerced_values", "cloned_values"]
    cloned_values = None
    coerced_values = None
    assignment_overloads = None

    def _check_const_assignment(self, node):
        if isinstance(node, CascadedAssignmentNode):
            for lhs in node.lhs_list:
                self._warn_on_const_assignment(lhs, node.rhs)

    def analyse_declarations(self, env):
        for lhs in self.lhs_list:
            lhs.analyse_target_declaration(env)

    def analyse_types(self, env, use_temp=0):
        from .ExprNodes import CloneNode, ProxyNode

        # collect distinct types used on the LHS
        lhs_types = set()
        for i, lhs in enumerate(self.lhs_list):
            lhs = self.lhs_list[i] = lhs.analyse_target_types(env)
            lhs.gil_assignment_check(env)
            lhs_types.add(lhs.type)

        rhs = self.rhs.analyse_types(env)
        # common special case: only one type needed on the LHS => coerce only once
        if len(lhs_types) == 1:
            # Avoid coercion for overloaded assignment operators.
            if next(iter(lhs_types)).is_cpp_class:
                op = env.lookup_operator('=', [lhs, self.rhs])
                if not op:
                    rhs = rhs.coerce_to(lhs_types.pop(), env)
            else:
                rhs = rhs.coerce_to(lhs_types.pop(), env)

        if not rhs.is_name and not rhs.is_literal and (
                use_temp or rhs.is_attribute or rhs.type.is_pyobject):
            rhs = rhs.coerce_to_temp(env)
        else:
            rhs = rhs.coerce_to_simple(env)
        self.rhs = ProxyNode(rhs) if rhs.result_in_temp() else rhs

        # clone RHS and coerce it to all distinct LHS types
        self.coerced_values = []
        coerced_values = {}
        self.assignment_overloads = []
        for lhs in self.lhs_list:
            overloaded = lhs.type.is_cpp_class and env.lookup_operator('=', [lhs, self.rhs])
            self.assignment_overloads.append(overloaded)
            if lhs.type not in coerced_values and lhs.type != rhs.type:
                rhs = CloneNode(self.rhs)
                if not overloaded:
                    rhs = rhs.coerce_to(lhs.type, env)
                self.coerced_values.append(rhs)
                coerced_values[lhs.type] = rhs

        # clone coerced values for all LHS assignments
        self.cloned_values = []
        for lhs in self.lhs_list:
            rhs = coerced_values.get(lhs.type, self.rhs)
            self.cloned_values.append(CloneNode(rhs))
        return self

    def generate_rhs_evaluation_code(self, code):
        self.rhs.generate_evaluation_code(code)

    def generate_assignment_code(self, code, overloaded_assignment=False):
        # prepare all coercions
        for rhs in self.coerced_values:
            rhs.generate_evaluation_code(code)
        # assign clones to LHS
        for lhs, rhs, overload in zip(self.lhs_list, self.cloned_values, self.assignment_overloads):
            rhs.generate_evaluation_code(code)
            lhs.generate_assignment_code(rhs, code, overloaded_assignment=overload)
        # dispose of coerced values and original RHS
        for rhs_value in self.coerced_values:
            rhs_value.generate_disposal_code(code)
            rhs_value.free_temps(code)
        self.rhs.generate_disposal_code(code)
        self.rhs.free_temps(code)

    def generate_function_definitions(self, env, code):
        self.rhs.generate_function_definitions(env, code)

    def annotate(self, code):
        for rhs in self.coerced_values:
            rhs.annotate(code)
        for lhs, rhs in zip(self.lhs_list, self.cloned_values):
            lhs.annotate(code)
            rhs.annotate(code)
        self.rhs.annotate(code)


class ParallelAssignmentNode(AssignmentNode):
    #  A combined packing/unpacking assignment:
    #
    #    a, b, c =  d, e, f
    #
    #  This has been rearranged by the parser into
    #
    #    a = d ; b = e ; c = f
    #
    #  but we must evaluate all the right hand sides
    #  before assigning to any of the left hand sides.
    #
    #  stats     [AssignmentNode]   The constituent assignments

    child_attrs = ["stats"]

    def analyse_declarations(self, env):
        for stat in self.stats:
            stat.analyse_declarations(env)

    def analyse_expressions(self, env):
        self.stats = [stat.analyse_types(env, use_temp=1)
                      for stat in self.stats]

        for stat in self.stats:
            stat._check_const_assignment(stat)
        return self

#    def analyse_expressions(self, env):
#        for stat in self.stats:
#            stat.analyse_expressions_1(env, use_temp=1)
#        for stat in self.stats:
#            stat.analyse_expressions_2(env)

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        for stat in self.stats:
            stat.generate_rhs_evaluation_code(code)
        for stat in self.stats:
            stat.generate_assignment_code(code)

    def generate_function_definitions(self, env, code):
        for stat in self.stats:
            stat.generate_function_definitions(env, code)

    def annotate(self, code):
        for stat in self.stats:
            stat.annotate(code)


class InPlaceAssignmentNode(AssignmentNode):
    #  An in place arithmetic operand:
    #
    #    a += b
    #    a -= b
    #    ...
    #
    #  lhs      ExprNode      Left hand side
    #  rhs      ExprNode      Right hand side
    #  operator char          one of "+-*/%^&|"
    #
    #  This code is a bit tricky because in order to obey Python
    #  semantics the sub-expressions (e.g. indices) of the lhs must
    #  not be evaluated twice. So we must reuse the values calculated
    #  in evaluation phase for the assignment phase as well.
    #  Fortunately, the type of the lhs node is fairly constrained
    #  (it must be a NameNode, AttributeNode, or IndexNode).

    child_attrs = ["lhs", "rhs"]

    def analyse_declarations(self, env):
        self.lhs.analyse_target_declaration(env)

    def analyse_types(self, env):
        self.rhs = self.rhs.analyse_types(env)
        self.lhs = self.lhs.analyse_target_types(env)

        # When assigning to a fully indexed buffer or memoryview, coerce the rhs
        if self.lhs.is_memview_index or self.lhs.is_buffer_access:
            self.rhs = self.rhs.coerce_to(self.lhs.type, env)
        elif self.lhs.type.is_string and self.operator in '+-':
            # use pointer arithmetic for char* LHS instead of string concat
            self.rhs = self.rhs.coerce_to(PyrexTypes.c_py_ssize_t_type, env)
        return self

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        lhs, rhs = self.lhs, self.rhs
        rhs.generate_evaluation_code(code)
        lhs.generate_subexpr_evaluation_code(code)
        c_op = self.operator
        if c_op == "//":
            c_op = "/"
        elif c_op == "**":
            error(self.pos, "No C inplace power operator")
        if lhs.is_buffer_access or lhs.is_memview_index:
            if lhs.type.is_pyobject:
                error(self.pos, "In-place operators not allowed on object buffers in this release.")
            if c_op in ('/', '%') and lhs.type.is_int and not code.globalstate.directives['cdivision']:
                error(self.pos, "In-place non-c divide operators not allowed on int buffers.")
            lhs.generate_buffer_setitem_code(rhs, code, c_op)
        elif lhs.is_memview_slice:
            error(self.pos, "Inplace operators not supported on memoryview slices")
        else:
            # C++
            # TODO: make sure overload is declared
            code.putln("%s %s= %s;" % (lhs.result(), c_op, rhs.result()))
        lhs.generate_subexpr_disposal_code(code)
        lhs.free_subexpr_temps(code)
        rhs.generate_disposal_code(code)
        rhs.free_temps(code)

    def annotate(self, code):
        self.lhs.annotate(code)
        self.rhs.annotate(code)

    def create_binop_node(self):
        from . import ExprNodes
        return ExprNodes.binop_node(self.pos, self.operator, self.lhs, self.rhs)


class PrintStatNode(StatNode):
    #  print statement
    #
    #  arg_tuple         TupleNode
    #  stream            ExprNode or None (stdout)
    #  append_newline    boolean

    child_attrs = ["arg_tuple", "stream"]

    def analyse_expressions(self, env):
        if self.stream:
            stream = self.stream.analyse_expressions(env)
            self.stream = stream.coerce_to_pyobject(env)
        arg_tuple = self.arg_tuple.analyse_expressions(env)
        self.arg_tuple = arg_tuple.coerce_to_pyobject(env)
        env.use_utility_code(printing_utility_code)
        if len(self.arg_tuple.args) == 1 and self.append_newline:
            env.use_utility_code(printing_one_utility_code)
        return self

    nogil_check = Node.gil_error
    gil_message = "Python print statement"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        if self.stream:
            self.stream.generate_evaluation_code(code)
            stream_result = self.stream.py_result()
        else:
            stream_result = '0'
        if len(self.arg_tuple.args) == 1 and self.append_newline:
            arg = self.arg_tuple.args[0]
            arg.generate_evaluation_code(code)

            code.putln(
                "if (__Pyx_PrintOne(%s, %s) < 0) %s" % (
                    stream_result,
                    arg.py_result(),
                    code.error_goto(self.pos)))
            arg.generate_disposal_code(code)
            arg.free_temps(code)
        else:
            self.arg_tuple.generate_evaluation_code(code)
            code.putln(
                "if (__Pyx_Print(%s, %s, %d) < 0) %s" % (
                    stream_result,
                    self.arg_tuple.py_result(),
                    self.append_newline,
                    code.error_goto(self.pos)))
            self.arg_tuple.generate_disposal_code(code)
            self.arg_tuple.free_temps(code)

        if self.stream:
            self.stream.generate_disposal_code(code)
            self.stream.free_temps(code)

    def generate_function_definitions(self, env, code):
        if self.stream:
            self.stream.generate_function_definitions(env, code)
        self.arg_tuple.generate_function_definitions(env, code)

    def annotate(self, code):
        if self.stream:
            self.stream.annotate(code)
        self.arg_tuple.annotate(code)


class ExecStatNode(StatNode):
    #  exec statement
    #
    #  args     [ExprNode]

    child_attrs = ["args"]

    def analyse_expressions(self, env):
        for i, arg in enumerate(self.args):
            arg = arg.analyse_expressions(env)
            arg = arg.coerce_to_pyobject(env)
            self.args[i] = arg
        env.use_utility_code(Builtin.pyexec_utility_code)
        return self

    nogil_check = Node.gil_error
    gil_message = "Python exec statement"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        args = []
        for arg in self.args:
            arg.generate_evaluation_code(code)
            args.append(arg.py_result())
        args = tuple(args + ['0', '0'][:3-len(args)])
        temp_result = code.funcstate.allocate_temp(PyrexTypes.py_object_type, manage_ref=True)
        code.putln("%s = __Pyx_PyExec3(%s, %s, %s);" % ((temp_result,) + args))
        for arg in self.args:
            arg.generate_disposal_code(code)
            arg.free_temps(code)
        code.putln(
            code.error_goto_if_null(temp_result, self.pos))
        code.put_gotref(temp_result, py_object_type)
        code.put_decref_clear(temp_result, py_object_type)
        code.funcstate.release_temp(temp_result)

    def annotate(self, code):
        for arg in self.args:
            arg.annotate(code)


class DelStatNode(StatNode):
    #  del statement
    #
    #  args     [ExprNode]

    child_attrs = ["args"]
    ignore_nonexisting = False

    def analyse_declarations(self, env):
        for arg in self.args:
            arg.analyse_target_declaration(env)

    def analyse_expressions(self, env):
        for i, arg in enumerate(self.args):
            arg = self.args[i] = arg.analyse_target_expression(env, None)
            if arg.type.is_pyobject or (arg.is_name and arg.type.is_memoryviewslice):
                if arg.is_name and arg.entry.is_cglobal:
                    error(arg.pos, "Deletion of global C variable")
            elif arg.type.is_ptr and arg.type.base_type.is_cpp_class:
                self.cpp_check(env)
            elif arg.type.is_cpp_class:
                error(arg.pos, "Deletion of non-heap C++ object")
            elif arg.is_subscript and arg.base.type is Builtin.bytearray_type:
                pass  # del ba[i]
            else:
                error(arg.pos, "Deletion of non-Python, non-C++ object")
            #arg.release_target_temp(env)
        return self

    def nogil_check(self, env):
        for arg in self.args:
            if arg.type.is_pyobject:
                self.gil_error()

    gil_message = "Deleting Python object"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        for arg in self.args:
            if (arg.type.is_pyobject or
                    arg.type.is_memoryviewslice or
                    arg.is_subscript and arg.base.type is Builtin.bytearray_type):
                arg.generate_deletion_code(
                    code, ignore_nonexisting=self.ignore_nonexisting)
            elif arg.type.is_ptr and arg.type.base_type.is_cpp_class:
                arg.generate_evaluation_code(code)
                code.putln("delete %s;" % arg.result())
                arg.generate_disposal_code(code)
                arg.free_temps(code)
            # else error reported earlier

    def annotate(self, code):
        for arg in self.args:
            arg.annotate(code)


class PassStatNode(StatNode):
    #  pass statement

    child_attrs = []

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        if code.globalstate.directives['linetrace']:
            code.mark_pos(self.pos)


class IndirectionNode(StatListNode):
    """
    This adds an indirection so that the node can be shared and a subtree can
    be removed at any time by clearing self.stats.
    """

    def __init__(self, stats):
        super().__init__(stats[0].pos, stats=stats)


class BreakStatNode(StatNode):

    child_attrs = []
    is_terminator = True

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        if not code.break_label:
            error(self.pos, "break statement not inside loop")
        else:
            code.put_goto(code.break_label)


class ContinueStatNode(StatNode):

    child_attrs = []
    is_terminator = True

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        if not code.continue_label:
            error(self.pos, "continue statement not inside loop")
            return
        code.mark_pos(self.pos)
        code.put_goto(code.continue_label)


class ReturnStatNode(StatNode):
    #  return statement
    #
    #  value         ExprNode or None
    #  return_type   PyrexType
    #  in_generator  return inside of generator => raise StopIteration
    #  in_async_gen  return inside of async generator

    child_attrs = ["value"]
    is_terminator = True
    in_generator = False
    in_async_gen = False

    # Whether we are in a parallel section
    in_parallel = False

    def analyse_expressions(self, env):
        return_type = env.return_type
        self.return_type = return_type
        if not return_type:
            error(self.pos, "Return not inside a function body")
            return self
        if self.value:
            if self.in_async_gen:
                error(self.pos, "Return with value in async generator")
            self.value = self.value.analyse_types(env)
            if return_type.is_void or return_type.is_returncode:
                error(self.value.pos, "Return with value in void function")
            else:
                self.value = self.value.coerce_to(env.return_type, env)
                if env.directives['profile'] or env.directives['linetrace']:
                    if not return_type.is_pyobject and return_type.can_coerce_to_pyobject(env):
                        return_type.create_to_py_utility_code(env)
        else:
            if (not return_type.is_void
                    and not return_type.is_pyobject
                    and not return_type.is_returncode):
                error(self.pos, "Return value required")
        return self

    def nogil_check(self, env):
        if self.return_type.is_pyobject:
            self.gil_error()

    gil_message = "Returning Python object"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        if not self.return_type:
            # error reported earlier
            return

        value = self.value
        if self.return_type.is_pyobject:
            code.put_xdecref(Naming.retval_cname, self.return_type)
            if value and value.is_none:
                # Use specialised default handling for "return None".
                value = None

        if value:
            value.generate_evaluation_code(code)
            if self.return_type.is_memoryviewslice:
                from . import MemoryView
                MemoryView.put_acquire_memoryviewslice(
                    lhs_cname=Naming.retval_cname,
                    lhs_type=self.return_type,
                    lhs_pos=value.pos,
                    rhs=value,
                    code=code,
                    have_gil=self.in_nogil_context)
                value.generate_post_assignment_code(code)
            else:
                value.make_owned_reference(code)
                code.putln("%s = %s;" % (
                    Naming.retval_cname,
                    value.result_as(self.return_type)))
                value.generate_post_assignment_code(code)
            value.free_temps(code)
        else:
            if self.return_type.is_pyobject:
                code.put_init_to_py_none(Naming.retval_cname, self.return_type)
            elif self.return_type.is_returncode:
                self.put_return(code, self.return_type.default_value)

        if code.globalstate.directives['profile'] or code.globalstate.directives['linetrace']:
            code.put_trace_return(
                Naming.retval_cname,
                self.pos,
                return_type=self.return_type,
                nogil=not code.funcstate.gil_owned,
            )

        for cname, type in code.funcstate.temps_holding_reference():
            code.put_decref_clear(cname, type)

        code.put_goto(code.return_label)

    def put_return(self, code, value):
        if self.in_parallel:
            code.putln_openmp("#pragma omp critical(__pyx_returning)")
        code.putln("%s = %s;" % (Naming.retval_cname, value))

    def generate_function_definitions(self, env, code):
        if self.value is not None:
            self.value.generate_function_definitions(env, code)

    def annotate(self, code):
        if self.value:
            self.value.annotate(code)


class RaiseStatNode(StatNode):
    #  raise statement
    #
    #  exc_type    ExprNode or None
    #  exc_value   ExprNode or None
    #  exc_tb      ExprNode or None
    #  cause       ExprNode or None
    #
    # set in FlowControl
    #  in_try_block  bool

    child_attrs = ["exc_type", "exc_value", "exc_tb", "cause"]
    is_terminator = True
    builtin_exc_name = None
    wrap_tuple_value = False
    in_try_block = False

    def analyse_expressions(self, env):
        if self.exc_type:
            exc_type = self.exc_type.analyse_types(env)
            self.exc_type = exc_type.coerce_to_pyobject(env)
        if self.exc_value:
            exc_value = self.exc_value.analyse_types(env)
            if self.wrap_tuple_value:
                if exc_value.type is Builtin.tuple_type or not exc_value.type.is_builtin_type:
                    # prevent tuple values from being interpreted as argument value tuples
                    from .ExprNodes import TupleNode
                    exc_value = TupleNode(exc_value.pos, args=[exc_value.coerce_to_pyobject(env)], slow=True)
                    exc_value = exc_value.analyse_types(env, skip_children=True)
            self.exc_value = exc_value.coerce_to_pyobject(env)
        if self.exc_tb:
            exc_tb = self.exc_tb.analyse_types(env)
            self.exc_tb = exc_tb.coerce_to_pyobject(env)
        if self.cause:
            cause = self.cause.analyse_types(env)
            self.cause = cause.coerce_to_pyobject(env)
        # special cases for builtin exceptions
        if self.exc_type and not self.exc_value and not self.exc_tb:
            exc = self.exc_type
            from . import ExprNodes
            if (isinstance(exc, ExprNodes.SimpleCallNode) and
                    not (exc.args or (exc.arg_tuple is not None and exc.arg_tuple.args))):
                exc = exc.function  # extract the exception type
            if exc.is_name and exc.entry.is_builtin:
                from . import Symtab
                self.builtin_exc_name = exc.name
                if self.builtin_exc_name == 'MemoryError':
                    self.exc_type = None  # has a separate implementation
                elif (self.builtin_exc_name == 'StopIteration' and
                        env.is_local_scope and env.name == "__next__" and
                        env.parent_scope and env.parent_scope.is_c_class_scope and
                        not self.in_try_block):
                    # tp_iternext is allowed to return NULL without raising StopIteration.
                    # For the sake of simplicity, only allow this to happen when not in
                    # a try block
                    self.exc_type = None

        return self

    nogil_check = Node.gil_error
    gil_message = "Raising exception"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        if self.builtin_exc_name == 'MemoryError':
            code.putln('PyErr_NoMemory(); %s' % code.error_goto(self.pos))
            return
        elif self.builtin_exc_name == 'StopIteration' and not self.exc_type:
            code.putln('%s = 1;' % Naming.error_without_exception_cname)
            code.putln('%s;' % code.error_goto(None))
            code.funcstate.error_without_exception = True
            return

        if self.exc_type:
            self.exc_type.generate_evaluation_code(code)
            type_code = self.exc_type.py_result()
            if self.exc_type.is_name:
                code.globalstate.use_entry_utility_code(self.exc_type.entry)
        else:
            type_code = "0"
        if self.exc_value:
            self.exc_value.generate_evaluation_code(code)
            value_code = self.exc_value.py_result()
        else:
            value_code = "0"
        if self.exc_tb:
            self.exc_tb.generate_evaluation_code(code)
            tb_code = self.exc_tb.py_result()
        else:
            tb_code = "0"
        if self.cause:
            self.cause.generate_evaluation_code(code)
            cause_code = self.cause.py_result()
        else:
            cause_code = "0"
        code.globalstate.use_utility_code(raise_utility_code)
        code.putln(
            "__Pyx_Raise(%s, %s, %s, %s);" % (
                type_code,
                value_code,
                tb_code,
                cause_code))

        for obj in (self.exc_type, self.exc_value, self.exc_tb, self.cause):
            if obj:
                obj.generate_disposal_code(code)
                obj.free_temps(code)
        code.putln(
            code.error_goto(self.pos))

    def generate_function_definitions(self, env, code):
        if self.exc_type is not None:
            self.exc_type.generate_function_definitions(env, code)
        if self.exc_value is not None:
            self.exc_value.generate_function_definitions(env, code)
        if self.exc_tb is not None:
            self.exc_tb.generate_function_definitions(env, code)
        if self.cause is not None:
            self.cause.generate_function_definitions(env, code)

    def annotate(self, code):
        if self.exc_type:
            self.exc_type.annotate(code)
        if self.exc_value:
            self.exc_value.annotate(code)
        if self.exc_tb:
            self.exc_tb.annotate(code)
        if self.cause:
            self.cause.annotate(code)


class ReraiseStatNode(StatNode):

    child_attrs = []
    is_terminator = True

    def analyse_expressions(self, env):
        return self

    nogil_check = Node.gil_error
    gil_message = "Raising exception"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        vars = code.funcstate.exc_vars
        if vars:
            code.globalstate.use_utility_code(restore_exception_utility_code)
            code.put_giveref(vars[0], py_object_type)
            code.put_giveref(vars[1], py_object_type)
            # fresh exceptions may not have a traceback yet (-> finally!)
            code.put_xgiveref(vars[2], py_object_type)
            code.putln("__Pyx_ErrRestoreWithState(%s, %s, %s);" % tuple(vars))
            code.putln(" ".join([f"{varname} = 0; " for varname in vars]))
        else:
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("ReRaiseException", "Exceptions.c"))
            code.putln("__Pyx_ReraiseException();")
        if code.is_tracing():
            code.put_trace_exception(self.pos, reraise=True)
        code.putln(code.error_goto(self.pos))


class AssertStatNode(StatNode):
    #  assert statement
    #
    #  condition    ExprNode
    #  value        ExprNode or None
    #  exception    (Raise/GIL)StatNode   created from 'value' in PostParse transform

    child_attrs = ["condition", "value", "exception"]
    exception = None

    def analyse_declarations(self, env):
        assert self.value is None, "Message should have been replaced in PostParse()"
        assert self.exception is not None, "Message should have been replaced in PostParse()"
        self.exception.analyse_declarations(env)

    def analyse_expressions(self, env):
        self.condition = self.condition.analyse_temp_boolean_expression(env)
        self.exception = self.exception.analyse_expressions(env)
        return self

    def generate_execution_code(self, code):
        code.globalstate.use_utility_code(
            UtilityCode.load_cached("AssertionsEnabled", "Exceptions.c"))
        code.putln("#ifndef CYTHON_WITHOUT_ASSERTIONS")
        code.putln("if (unlikely(__pyx_assertions_enabled())) {")
        code.mark_pos(self.pos)
        self.condition.generate_evaluation_code(code)
        code.putln(
            "if (unlikely(!%s)) {" % self.condition.result())
        self.exception.generate_execution_code(code)
        code.putln(
            "}")
        self.condition.generate_disposal_code(code)
        self.condition.free_temps(code)
        code.putln(
            "}")
        code.putln("#else")
        # avoid unused labels etc.
        code.putln("if ((1)); else %s" % code.error_goto(self.pos, used=False))
        code.putln("#endif")

    def generate_function_definitions(self, env, code):
        self.condition.generate_function_definitions(env, code)
        self.exception.generate_function_definitions(env, code)

    def annotate(self, code):
        self.condition.annotate(code)
        self.exception.annotate(code)


class IfStatNode(StatNode):
    #  if statement
    #
    #  if_clauses   [IfClauseNode]
    #  else_clause  StatNode or None

    child_attrs = ["if_clauses", "else_clause"]

    def analyse_declarations(self, env):
        for if_clause in self.if_clauses:
            if_clause.analyse_declarations(env)
        if self.else_clause:
            self.else_clause.analyse_declarations(env)

    def analyse_expressions(self, env):
        self.if_clauses = [if_clause.analyse_expressions(env) for if_clause in self.if_clauses]
        if self.else_clause:
            self.else_clause = self.else_clause.analyse_expressions(env)
        return self

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        end_label = code.new_label()
        last = len(self.if_clauses)
        if not self.else_clause:
            last -= 1  # avoid redundant goto at end of last if-clause
        for i, if_clause in enumerate(self.if_clauses):
            if_clause.generate_execution_code(code, end_label, is_last=i == last)
        if self.else_clause:
            code.mark_pos(self.else_clause.pos)
            code.putln("/*else*/ {")
            self.else_clause.generate_execution_code(code)
            code.putln("}")
        code.put_label(end_label)

    def generate_function_definitions(self, env, code):
        for clause in self.if_clauses:
            clause.generate_function_definitions(env, code)
        if self.else_clause is not None:
            self.else_clause.generate_function_definitions(env, code)

    def annotate(self, code):
        for if_clause in self.if_clauses:
            if_clause.annotate(code)
        if self.else_clause:
            self.else_clause.annotate(code)


class IfClauseNode(Node):
    #  if or elif clause in an if statement
    #
    #  condition   ExprNode
    #  body        StatNode

    child_attrs = ["condition", "body"]
    branch_hint = None

    def analyse_declarations(self, env):
        self.body.analyse_declarations(env)

    def analyse_expressions(self, env):
        self.condition = self.condition.analyse_temp_boolean_expression(env)
        self.body = self.body.analyse_expressions(env)
        return self

    def generate_execution_code(self, code, end_label, is_last):
        self.condition.generate_evaluation_code(code)
        code.mark_pos(self.pos)
        condition = self.condition.result()
        if self.branch_hint:
            condition = '%s(%s)' % (self.branch_hint, condition)
        code.putln("if (%s) {" % condition)
        self.condition.generate_disposal_code(code)
        self.condition.free_temps(code)
        self.body.generate_execution_code(code)
        code.mark_pos(self.pos, trace=False)
        if not (is_last or self.body.is_terminator):
            code.put_goto(end_label)
        code.putln("}")

    def generate_function_definitions(self, env, code):
        self.condition.generate_function_definitions(env, code)
        self.body.generate_function_definitions(env, code)

    def annotate(self, code):
        self.condition.annotate(code)
        self.body.annotate(code)


class SwitchCaseNode(StatNode):
    # Generated in the optimization of an if-elif-else node
    #
    # conditions    [ExprNode]
    # body          StatNode

    child_attrs = ['conditions', 'body']

    def generate_condition_evaluation_code(self, code):
        for cond in self.conditions:
            cond.generate_evaluation_code(code)

    def generate_execution_code(self, code):
        num_conditions = len(self.conditions)
        line_tracing_enabled = code.globalstate.directives['linetrace']
        for i, cond in enumerate(self.conditions, 1):
            code.putln("case %s:" % cond.result())
            code.mark_pos(cond.pos)  # Tracing code must appear *after* the 'case' statement.
            if line_tracing_enabled and i < num_conditions:
                # Allow fall-through after the line tracing code.
                code.putln('CYTHON_FALLTHROUGH;')
        self.body.generate_execution_code(code)
        code.mark_pos(self.pos, trace=False)
        code.putln("break;")

    def generate_function_definitions(self, env, code):
        for cond in self.conditions:
            cond.generate_function_definitions(env, code)
        self.body.generate_function_definitions(env, code)

    def annotate(self, code):
        for cond in self.conditions:
            cond.annotate(code)
        self.body.annotate(code)


class SwitchStatNode(StatNode):
    # Generated in the optimization of an if-elif-else node
    #
    # test          ExprNode
    # cases         [SwitchCaseNode]
    # else_clause   StatNode or None

    child_attrs = ['test', 'cases', 'else_clause']

    def generate_execution_code(self, code):
        self.test.generate_evaluation_code(code)
        # Make sure all conditions are evaluated before going into the switch() statement.
        # This is required in order to prevent any execution code from leaking into the space between the cases.
        for case in self.cases:
            case.generate_condition_evaluation_code(code)
        code.mark_pos(self.pos)
        code.putln("switch (%s) {" % self.test.result())
        for case in self.cases:
            case.generate_execution_code(code)
        if self.else_clause is not None:
            code.putln("default:")
            self.else_clause.generate_execution_code(code)
            code.putln("break;")
        else:
            # Always generate a default clause to prevent C compiler warnings
            # about unmatched enum values (it was not the user who decided to
            # generate the switch statement, so shouldn't be bothered).
            code.putln("default: break;")
        code.putln("}")
        self.test.generate_disposal_code(code)
        self.test.free_temps(code)

    def generate_function_definitions(self, env, code):
        self.test.generate_function_definitions(env, code)
        for case in self.cases:
            case.generate_function_definitions(env, code)
        if self.else_clause is not None:
            self.else_clause.generate_function_definitions(env, code)

    def annotate(self, code):
        self.test.annotate(code)
        for case in self.cases:
            case.annotate(code)
        if self.else_clause is not None:
            self.else_clause.annotate(code)


class LoopNode:
    pass


class WhileStatNode(LoopNode, StatNode):
    #  while statement
    #
    #  condition    ExprNode
    #  body         StatNode
    #  else_clause  StatNode

    child_attrs = ["condition", "body", "else_clause"]

    def analyse_declarations(self, env):
        self.body.analyse_declarations(env)
        if self.else_clause:
            self.else_clause.analyse_declarations(env)

    def analyse_expressions(self, env):
        if self.condition:
            self.condition = self.condition.analyse_temp_boolean_expression(env)
        self.body = self.body.analyse_expressions(env)
        if self.else_clause:
            self.else_clause = self.else_clause.analyse_expressions(env)
        return self

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        old_loop_labels = code.new_loop_labels()
        code.putln(
            "while (1) {")
        if self.condition:
            self.condition.generate_evaluation_code(code)
            self.condition.generate_disposal_code(code)
            code.putln(
                "if (!%s) break;" % self.condition.result())
            self.condition.free_temps(code)
        self.body.generate_execution_code(code)
        code.put_label(code.continue_label)
        code.putln("}")
        break_label = code.break_label
        code.set_loop_labels(old_loop_labels)
        if self.else_clause:
            code.mark_pos(self.else_clause.pos)
            code.putln("/*else*/ {")
            self.else_clause.generate_execution_code(code)
            code.putln("}")
        code.put_label(break_label)

    def generate_function_definitions(self, env, code):
        if self.condition:
            self.condition.generate_function_definitions(env, code)
        self.body.generate_function_definitions(env, code)
        if self.else_clause is not None:
            self.else_clause.generate_function_definitions(env, code)

    def annotate(self, code):
        if self.condition:
            self.condition.annotate(code)
        self.body.annotate(code)
        if self.else_clause:
            self.else_clause.annotate(code)


class DictIterationNextNode(Node):
    # Helper node for calling PyDict_Next() inside of a WhileStatNode
    # and checking the dictionary size for changes.  Created in
    # Optimize.py.
    child_attrs = ['dict_obj', 'expected_size', 'pos_index_var',
                   'coerced_key_var', 'coerced_value_var', 'coerced_tuple_var',
                   'key_target', 'value_target', 'tuple_target', 'is_dict_flag']

    coerced_key_var = key_ref = None
    coerced_value_var = value_ref = None
    coerced_tuple_var = tuple_ref = None

    def __init__(self, dict_obj, expected_size, pos_index_var,
                 key_target, value_target, tuple_target, is_dict_flag):
        Node.__init__(
            self, dict_obj.pos,
            dict_obj=dict_obj,
            expected_size=expected_size,
            pos_index_var=pos_index_var,
            key_target=key_target,
            value_target=value_target,
            tuple_target=tuple_target,
            is_dict_flag=is_dict_flag,
            is_temp=True,
            type=PyrexTypes.c_bint_type)

    def analyse_expressions(self, env):
        from . import ExprNodes
        self.dict_obj = self.dict_obj.analyse_types(env)
        self.expected_size = self.expected_size.analyse_types(env)
        if self.pos_index_var:
            self.pos_index_var = self.pos_index_var.analyse_types(env)
        if self.key_target:
            self.key_target = self.key_target.analyse_target_types(env)
            self.key_ref = ExprNodes.TempNode(self.key_target.pos, PyrexTypes.py_object_type)
            self.coerced_key_var = self.key_ref.coerce_to(self.key_target.type, env)
        if self.value_target:
            self.value_target = self.value_target.analyse_target_types(env)
            self.value_ref = ExprNodes.TempNode(self.value_target.pos, type=PyrexTypes.py_object_type)
            self.coerced_value_var = self.value_ref.coerce_to(self.value_target.type, env)
        if self.tuple_target:
            self.tuple_target = self.tuple_target.analyse_target_types(env)
            self.tuple_ref = ExprNodes.TempNode(self.tuple_target.pos, PyrexTypes.py_object_type)
            self.coerced_tuple_var = self.tuple_ref.coerce_to(self.tuple_target.type, env)
        self.is_dict_flag = self.is_dict_flag.analyse_types(env)
        return self

    def generate_function_definitions(self, env, code):
        self.dict_obj.generate_function_definitions(env, code)

    def generate_execution_code(self, code):
        code.globalstate.use_utility_code(UtilityCode.load_cached("dict_iter", "Optimize.c"))
        self.dict_obj.generate_evaluation_code(code)

        assignments = []
        temp_addresses = []
        for var, result, target in [(self.key_ref, self.coerced_key_var, self.key_target),
                                    (self.value_ref, self.coerced_value_var, self.value_target),
                                    (self.tuple_ref, self.coerced_tuple_var, self.tuple_target)]:
            if target is None:
                addr = 'NULL'
            else:
                assignments.append((var, result, target))
                var.allocate(code)
                addr = '&%s' % var.result()
            temp_addresses.append(addr)

        result_temp = code.funcstate.allocate_temp(PyrexTypes.c_int_type, False)
        code.putln("%s = __Pyx_dict_iter_next(%s, %s, &%s, %s, %s, %s, %s);" % (
            result_temp,
            self.dict_obj.py_result(),
            self.expected_size.result(),
            self.pos_index_var.result(),
            temp_addresses[0],
            temp_addresses[1],
            temp_addresses[2],
            self.is_dict_flag.result()
        ))
        code.putln("if (unlikely(%s == 0)) break;" % result_temp)
        code.putln(code.error_goto_if("%s == -1" % result_temp, self.pos))
        code.funcstate.release_temp(result_temp)

        # evaluate all coercions before the assignments
        for var, result, target in assignments:
            var.generate_gotref(code)
        for var, result, target in assignments:
            result.generate_evaluation_code(code)
        for var, result, target in assignments:
            target.generate_assignment_code(result, code)
            var.release(code)


class SetIterationNextNode(Node):
    # Helper node for calling _PySet_NextEntry() inside of a WhileStatNode
    # and checking the set size for changes.  Created in Optimize.py.
    child_attrs = ['set_obj', 'expected_size', 'pos_index_var',
                   'coerced_value_var', 'value_target', 'is_set_flag']

    coerced_value_var = value_ref = None

    def __init__(self, set_obj, expected_size, pos_index_var, value_target, is_set_flag):
        Node.__init__(
            self, set_obj.pos,
            set_obj=set_obj,
            expected_size=expected_size,
            pos_index_var=pos_index_var,
            value_target=value_target,
            is_set_flag=is_set_flag,
            is_temp=True,
            type=PyrexTypes.c_bint_type)

    def analyse_expressions(self, env):
        from . import ExprNodes
        self.set_obj = self.set_obj.analyse_types(env)
        self.expected_size = self.expected_size.analyse_types(env)
        self.pos_index_var = self.pos_index_var.analyse_types(env)
        self.value_target = self.value_target.analyse_target_types(env)
        self.value_ref = ExprNodes.TempNode(self.value_target.pos, type=PyrexTypes.py_object_type)
        self.coerced_value_var = self.value_ref.coerce_to(self.value_target.type, env)
        self.is_set_flag = self.is_set_flag.analyse_types(env)
        return self

    def generate_function_definitions(self, env, code):
        self.set_obj.generate_function_definitions(env, code)

    def generate_execution_code(self, code):
        code.globalstate.use_utility_code(UtilityCode.load_cached("set_iter", "Optimize.c"))
        self.set_obj.generate_evaluation_code(code)

        value_ref = self.value_ref
        value_ref.allocate(code)

        result_temp = code.funcstate.allocate_temp(PyrexTypes.c_int_type, False)
        code.putln("%s = __Pyx_set_iter_next(%s, %s, &%s, &%s, %s);" % (
            result_temp,
            self.set_obj.py_result(),
            self.expected_size.result(),
            self.pos_index_var.result(),
            value_ref.result(),
            self.is_set_flag.result()
        ))
        code.putln("if (unlikely(%s == 0)) break;" % result_temp)
        code.putln(code.error_goto_if("%s == -1" % result_temp, self.pos))
        code.funcstate.release_temp(result_temp)

        # evaluate all coercions before the assignments
        value_ref.generate_gotref(code)
        self.coerced_value_var.generate_evaluation_code(code)
        self.value_target.generate_assignment_code(self.coerced_value_var, code)
        value_ref.release(code)


def ForStatNode(pos, **kw):
    if 'iterator' in kw:
        if kw['iterator'].is_async:
            return AsyncForStatNode(pos, **kw)
        else:
            return ForInStatNode(pos, **kw)
    else:
        return ForFromStatNode(pos, **kw)


class _ForInStatNode(LoopNode, StatNode):
    #  Base class of 'for-in' statements.
    #
    #  target        ExprNode
    #  iterator      IteratorNode | AIterAwaitExprNode(AsyncIteratorNode)
    #  body          StatNode
    #  else_clause   StatNode
    #  item          NextNode | AwaitExprNode(AsyncNextNode)
    #  is_async      boolean        true for 'async for' statements

    child_attrs = ["target", "item", "iterator", "body", "else_clause"]
    item = None
    is_async = False

    def _create_item_node(self):
        raise NotImplementedError("must be implemented by subclasses")

    def analyse_declarations(self, env):
        self.target.analyse_target_declaration(env)
        self.body.analyse_declarations(env)
        if self.else_clause:
            self.else_clause.analyse_declarations(env)
        self._create_item_node()

    def analyse_expressions(self, env):
        self.target = self.target.analyse_target_types(env)
        self.iterator = self.iterator.analyse_expressions(env)
        self._create_item_node()  # must rewrap self.item after analysis
        self.item = self.item.analyse_expressions(env)
        if (not self.is_async and
                (self.iterator.type.is_ptr or self.iterator.type.is_array) and
                self.target.type.assignable_from(self.iterator.type)):
            # C array slice optimization.
            pass
        else:
            self.item = self.item.coerce_to(self.target.type, env)
        self.body = self.body.analyse_expressions(env)
        if self.else_clause:
            self.else_clause = self.else_clause.analyse_expressions(env)
        return self

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        old_loop_labels = code.new_loop_labels()
        self.iterator.generate_evaluation_code(code)
        code.put("for (")
        self.iterator.generate_for_loop_header(code)
        code.putln(") {")
        self.item.generate_evaluation_code(code)
        self.target.generate_assignment_code(self.item, code)
        code.write_trace_line(self.pos)
        self.body.generate_execution_code(code)
        code.mark_pos(self.pos)
        code.put_label(code.continue_label)
        code.putln("}")

        # clean up before we enter the 'else:' branch
        self.iterator.generate_disposal_code(code)

        else_label = code.new_label("for_else") if self.else_clause else None
        end_label = code.new_label("for_end")
        label_intercepts = code.label_interceptor(
            [code.break_label],
            [end_label],
            skip_to_label=else_label or end_label,
            pos=self.pos,
        )

        code.mark_pos(self.pos)
        for _ in label_intercepts:
            self.iterator.generate_disposal_code(code)

        code.set_loop_labels(old_loop_labels)
        self.iterator.free_temps(code)

        if self.else_clause:
            code.putln("/*else*/ {")
            code.put_label(else_label)
            self.else_clause.generate_execution_code(code)
            code.putln("}")

        code.put_label(end_label)

    def generate_function_definitions(self, env, code):
        self.target.generate_function_definitions(env, code)
        self.iterator.generate_function_definitions(env, code)
        self.body.generate_function_definitions(env, code)
        if self.else_clause is not None:
            self.else_clause.generate_function_definitions(env, code)

    def annotate(self, code):
        self.target.annotate(code)
        self.iterator.annotate(code)
        self.body.annotate(code)
        if self.else_clause:
            self.else_clause.annotate(code)
        self.item.annotate(code)


class ForInStatNode(_ForInStatNode):
    #  'for' statement

    is_async = False

    def _create_item_node(self):
        from .ExprNodes import NextNode
        self.item = NextNode(self.iterator)


class AsyncForStatNode(_ForInStatNode):
    #  'async for' statement
    #
    #  iterator      AIterAwaitExprNode(AsyncIteratorNode)
    #  item          AwaitIterNextExprNode(AsyncIteratorNode)

    is_async = True

    def __init__(self, pos, **kw):
        assert 'item' not in kw
        from . import ExprNodes
        # AwaitExprNodes must appear before running MarkClosureVisitor
        kw['item'] = ExprNodes.AwaitIterNextExprNode(kw['iterator'].pos, arg=None)
        _ForInStatNode.__init__(self, pos, **kw)

    def _create_item_node(self):
        from . import ExprNodes
        self.item.arg = ExprNodes.AsyncNextNode(self.iterator)


class ForFromStatNode(LoopNode, StatNode):
    #  for name from expr rel name rel expr
    #
    #  target        NameNode
    #  bound1        ExprNode
    #  relation1     string
    #  relation2     string
    #  bound2        ExprNode
    #  step          ExprNode or None
    #  body          StatNode
    #  else_clause   StatNode or None
    #
    #  Used internally:
    #
    #  from_range         bool
    #  is_py_target       bool
    #  loopvar_node       ExprNode (usually a NameNode or temp node)
    #  py_loopvar_node    PyTempNode or None
    child_attrs = ["target", "bound1", "bound2", "step", "body", "else_clause"]

    is_py_target = False
    loopvar_node = None
    py_loopvar_node = None
    from_range = False

    gil_message = "For-loop using object bounds or target"

    def nogil_check(self, env):
        for x in (self.target, self.bound1, self.bound2):
            if x.type.is_pyobject:
                self.gil_error()

    def analyse_declarations(self, env):
        self.target.analyse_target_declaration(env)
        self.body.analyse_declarations(env)
        if self.else_clause:
            self.else_clause.analyse_declarations(env)

    def analyse_expressions(self, env):
        from . import ExprNodes
        self.target = self.target.analyse_target_types(env)
        self.bound1 = self.bound1.analyse_types(env)
        self.bound2 = self.bound2.analyse_types(env)
        if self.step is not None:
            if isinstance(self.step, ExprNodes.UnaryMinusNode):
                warning(self.step.pos, "Probable infinite loop in for-from-by statement. "
                        "Consider switching the directions of the relations.", 2)
            self.step = self.step.analyse_types(env)

        self.set_up_loop(env)
        target_type = self.target.type
        if not (target_type.is_pyobject or target_type.is_numeric):
            error(self.target.pos, "for-from loop variable must be c numeric type or Python object")

        self.body = self.body.analyse_expressions(env)
        if self.else_clause:
            self.else_clause = self.else_clause.analyse_expressions(env)
        return self

    def set_up_loop(self, env):
        from . import ExprNodes

        target_type = self.target.type
        if target_type.is_numeric:
            loop_type = target_type
        else:
            if target_type.is_enum:
                warning(self.target.pos,
                        "Integer loops over enum values are fragile. Please cast to a safe integer type instead.")
            loop_type = PyrexTypes.c_long_type if target_type.is_pyobject else PyrexTypes.c_int_type
            if not self.bound1.type.is_pyobject:
                loop_type = PyrexTypes.widest_numeric_type(loop_type, self.bound1.type)
            if not self.bound2.type.is_pyobject:
                loop_type = PyrexTypes.widest_numeric_type(loop_type, self.bound2.type)
            if self.step is not None and not self.step.type.is_pyobject:
                loop_type = PyrexTypes.widest_numeric_type(loop_type, self.step.type)
        self.bound1 = self.bound1.coerce_to(loop_type, env)
        self.bound2 = self.bound2.coerce_to(loop_type, env)
        if not self.bound2.is_literal:
            self.bound2 = self.bound2.coerce_to_temp(env)
        if self.step is not None:
            self.step = self.step.coerce_to(loop_type, env)
            if not self.step.is_literal:
                self.step = self.step.coerce_to_temp(env)

        if target_type.is_numeric or target_type.is_enum:
            self.is_py_target = False
            if isinstance(self.target, ExprNodes.BufferIndexNode):
                raise error(self.pos, "Buffer or memoryview slicing/indexing not allowed as for-loop target.")
            self.loopvar_node = self.target
            self.py_loopvar_node = None
        else:
            self.is_py_target = True
            c_loopvar_node = ExprNodes.TempNode(self.pos, loop_type, env)
            self.loopvar_node = c_loopvar_node
            self.py_loopvar_node = ExprNodes.CloneNode(c_loopvar_node).coerce_to_pyobject(env)

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        old_loop_labels = code.new_loop_labels()
        from_range = self.from_range
        self.bound1.generate_evaluation_code(code)
        self.bound2.generate_evaluation_code(code)
        offset, incop = self.relation_table[self.relation1]
        if self.step is not None:
            self.step.generate_evaluation_code(code)
            step = self.step.result()
            incop = "%s=%s" % (incop[0], step)  # e.g. '++' => '+= STEP'
        else:
            step = '1'

        from . import ExprNodes
        if isinstance(self.loopvar_node, ExprNodes.TempNode):
            self.loopvar_node.allocate(code)
        if isinstance(self.py_loopvar_node, ExprNodes.TempNode):
            self.py_loopvar_node.allocate(code)

        loopvar_type = PyrexTypes.c_long_type if self.target.type.is_enum else self.target.type

        if from_range and not self.is_py_target:
            loopvar_name = code.funcstate.allocate_temp(loopvar_type, False)
        else:
            loopvar_name = self.loopvar_node.result()
        if loopvar_type.is_int and not loopvar_type.signed and self.relation2[0] == '>':
            # Handle the case where the endpoint of an unsigned int iteration
            # is within step of 0.
            code.putln("for (%s = %s%s + %s; %s %s %s + %s; ) { %s%s;" % (
                loopvar_name,
                self.bound1.result(), offset, step,
                loopvar_name, self.relation2, self.bound2.result(), step,
                loopvar_name, incop))
        else:
            code.putln("for (%s = %s%s; %s %s %s; %s%s) {" % (
                loopvar_name,
                self.bound1.result(), offset,
                loopvar_name, self.relation2, self.bound2.result(),
                loopvar_name, incop))

        coerced_loopvar_node = self.py_loopvar_node
        if coerced_loopvar_node is None and from_range:
            coerced_loopvar_node = ExprNodes.RawCNameExprNode(self.target.pos, loopvar_type, loopvar_name)
        if coerced_loopvar_node is not None:
            coerced_loopvar_node.generate_evaluation_code(code)
            self.target.generate_assignment_code(coerced_loopvar_node, code)

        code.write_trace_line(self.pos)
        self.body.generate_execution_code(code)
        code.put_label(code.continue_label)

        if not from_range and self.py_loopvar_node:
            # This mess is to make for..from loops with python targets behave
            # exactly like those with C targets with regards to re-assignment
            # of the loop variable.
            if self.target.entry.is_pyglobal:
                # We know target is a NameNode, this is the only ugly case.
                target_node = ExprNodes.PyTempNode(self.target.pos, None)
                target_node.allocate(code)
                interned_cname = code.intern_identifier(self.target.entry.name)
                if self.target.entry.scope.is_module_scope:
                    code.globalstate.use_utility_code(
                        UtilityCode.load_cached("GetModuleGlobalName", "ObjectHandling.c"))
                    lookup_func = '__Pyx_GetModuleGlobalName(%s, %s); %s'
                else:
                    code.globalstate.use_utility_code(
                        UtilityCode.load_cached("GetNameInClass", "ObjectHandling.c"))
                    lookup_func = '__Pyx_GetNameInClass(%s, {}, %s); %s'.format(
                        self.target.entry.scope.namespace_cname)
                code.putln(lookup_func % (
                    target_node.result(),
                    interned_cname,
                    code.error_goto_if_null(target_node.result(), self.target.pos)))
                target_node.generate_gotref(code)
            else:
                target_node = self.target
            from_py_node = ExprNodes.CoerceFromPyTypeNode(
                self.loopvar_node.type, target_node, self.target.entry.scope)
            from_py_node.temp_code = loopvar_name
            from_py_node.generate_result_code(code)
            if self.target.entry.is_pyglobal:
                code.put_decref(target_node.result(), target_node.type)
                target_node.release(code)

        code.putln("}")

        if not from_range and self.py_loopvar_node:
            # This is potentially wasteful, but we don't want the semantics to
            # depend on whether or not the loop is a python type.
            self.py_loopvar_node.generate_evaluation_code(code)
            self.target.generate_assignment_code(self.py_loopvar_node, code)
        if from_range and not self.is_py_target:
            code.funcstate.release_temp(loopvar_name)

        break_label = code.break_label
        code.set_loop_labels(old_loop_labels)
        if self.else_clause:
            code.putln("/*else*/ {")
            self.else_clause.generate_execution_code(code)
            code.putln("}")
        code.put_label(break_label)
        self.bound1.generate_disposal_code(code)
        self.bound1.free_temps(code)
        self.bound2.generate_disposal_code(code)
        self.bound2.free_temps(code)
        if isinstance(self.loopvar_node, ExprNodes.TempNode):
            self.loopvar_node.release(code)
        if isinstance(self.py_loopvar_node, ExprNodes.TempNode):
            self.py_loopvar_node.release(code)
        if self.step is not None:
            self.step.generate_disposal_code(code)
            self.step.free_temps(code)

    relation_table = {
        # {relop : (initial offset, increment op)}
        '<=': ("",   "++"),
        '<' : ("+1", "++"),
        '>=': ("",   "--"),
        '>' : ("-1", "--"),
    }

    def generate_function_definitions(self, env, code):
        self.target.generate_function_definitions(env, code)
        self.bound1.generate_function_definitions(env, code)
        self.bound2.generate_function_definitions(env, code)
        if self.step is not None:
            self.step.generate_function_definitions(env, code)
        self.body.generate_function_definitions(env, code)
        if self.else_clause is not None:
            self.else_clause.generate_function_definitions(env, code)

    def annotate(self, code):
        self.target.annotate(code)
        self.bound1.annotate(code)
        self.bound2.annotate(code)
        if self.step:
            self.step.annotate(code)
        self.body.annotate(code)
        if self.else_clause:
            self.else_clause.annotate(code)


class WithStatNode(StatNode):
    """
    Represents a Python with statement.

    Implemented by the WithTransform as follows:

        MGR = EXPR
        EXIT = MGR.__exit__
        VALUE = MGR.__enter__()
        EXC = True
        try:
            try:
                TARGET = VALUE  # optional
                BODY
            except:
                EXC = False
                if not EXIT(*EXCINFO):
                    raise
        finally:
            if EXC:
                EXIT(None, None, None)
            MGR = EXIT = VALUE = None
    """
    #  manager          The with statement manager object
    #  target           ExprNode  the target lhs of the __enter__() call
    #  body             StatNode
    #  enter_call       ExprNode  the call to the __enter__() method
    #  exit_var         String    the cname of the __exit__() method reference

    child_attrs = ["manager", "enter_call", "target", "body"]

    enter_call = None
    target_temp = None

    def analyse_declarations(self, env):
        self.manager.analyse_declarations(env)
        self.enter_call.analyse_declarations(env)
        self.body.analyse_declarations(env)

    def analyse_expressions(self, env):
        self.manager = self.manager.analyse_types(env)
        if self.manager.type.is_cython_lock_type:
            return CythonLockStatNode.from_withstat(self).analyse_expressions(env)
        self.enter_call = self.enter_call.analyse_types(env)
        if self.target:
            # set up target_temp before descending into body (which uses it)
            from .ExprNodes import TempNode
            self.target_temp = TempNode(self.enter_call.pos, self.enter_call.type)
        self.body = self.body.analyse_expressions(env)
        return self

    def generate_function_definitions(self, env, code):
        self.manager.generate_function_definitions(env, code)
        self.enter_call.generate_function_definitions(env, code)
        self.body.generate_function_definitions(env, code)

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        code.putln("/*with:*/ {")
        self.manager.generate_evaluation_code(code)
        self.exit_var = code.funcstate.allocate_temp(py_object_type, manage_ref=False)
        code.globalstate.use_utility_code(
            UtilityCode.load_cached("PyObjectLookupSpecial", "ObjectHandling.c"))
        code.putln("%s = __Pyx_PyObject_LookupSpecial(%s, %s); %s" % (
            self.exit_var,
            self.manager.py_result(),
            code.intern_identifier(EncodedString('__aexit__' if self.is_async else '__exit__')),
            code.error_goto_if_null(self.exit_var, self.pos),
            ))
        code.put_gotref(self.exit_var, py_object_type)

        # need to free exit_var in the face of exceptions during setup
        old_error_label = code.new_error_label()
        intermediate_error_label = code.error_label

        self.enter_call.generate_evaluation_code(code)
        if self.target:
            # The temp result will be cleaned up by the WithTargetAssignmentStatNode
            # after assigning its result to the target of the 'with' statement.
            self.target_temp.allocate(code)
            self.enter_call.make_owned_reference(code)
            code.putln("%s = %s;" % (self.target_temp.result(), self.enter_call.result()))
            self.enter_call.generate_post_assignment_code(code)
        else:
            self.enter_call.generate_disposal_code(code)
        self.enter_call.free_temps(code)

        self.manager.generate_disposal_code(code)
        self.manager.free_temps(code)

        code.error_label = old_error_label
        self.body.generate_execution_code(code)

        if code.label_used(intermediate_error_label):
            step_over_label = code.new_label()
            code.put_goto(step_over_label)
            code.put_label(intermediate_error_label)
            code.put_decref_clear(self.exit_var, py_object_type)
            code.put_goto(old_error_label)
            code.put_label(step_over_label)

        code.funcstate.release_temp(self.exit_var)
        code.putln('}')


class WithTargetAssignmentStatNode(AssignmentNode):
    # The target assignment of the 'with' statement value (return
    # value of the __enter__() call).
    #
    # This is a special cased assignment that properly cleans up the RHS.
    #
    # lhs       ExprNode      the assignment target
    # rhs       ExprNode      a (coerced) TempNode for the rhs (from WithStatNode)
    # with_node WithStatNode  the surrounding with-statement

    child_attrs = ["rhs", "lhs"]
    with_node = None
    rhs = None

    def analyse_declarations(self, env):
        self.lhs.analyse_target_declaration(env)

    def analyse_expressions(self, env):
        self.lhs = self.lhs.analyse_target_types(env)
        self.lhs.gil_assignment_check(env)
        self.rhs = self.with_node.target_temp.coerce_to(self.lhs.type, env)
        return self

    def generate_execution_code(self, code):
        self.rhs.generate_evaluation_code(code)
        self.lhs.generate_assignment_code(self.rhs, code)
        self.with_node.target_temp.release(code)

    def annotate(self, code):
        self.lhs.annotate(code)
        self.rhs.annotate(code)


class TryExceptStatNode(StatNode):
    #  try .. except statement
    #
    #  body             StatNode
    #  except_clauses   [ExceptClauseNode]
    #  else_clause      StatNode or None

    child_attrs = ["body", "except_clauses", "else_clause"]
    in_generator = False

    def analyse_declarations(self, env):
        self.body.analyse_declarations(env)
        for except_clause in self.except_clauses:
            except_clause.analyse_declarations(env)
        if self.else_clause:
            self.else_clause.analyse_declarations(env)

    def analyse_expressions(self, env):
        self.body = self.body.analyse_expressions(env)
        default_clause_seen = 0
        for i, except_clause in enumerate(self.except_clauses):
            except_clause = self.except_clauses[i] = except_clause.analyse_expressions(env)
            if default_clause_seen:
                error(except_clause.pos, "default 'except:' must be last")
            if not except_clause.pattern:
                default_clause_seen = 1
        self.has_default_clause = default_clause_seen
        if self.else_clause:
            self.else_clause = self.else_clause.analyse_expressions(env)
        return self

    nogil_check = Node.gil_error
    gil_message = "Try-except statement"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)  # before changing the error label, in case of tracing errors
        code.putln("{")

        old_return_label = code.return_label
        old_break_label = code.break_label
        old_continue_label = code.continue_label
        old_error_label = code.new_error_label()
        our_error_label = code.error_label
        except_end_label = code.new_label('exception_handled')
        except_error_label = code.new_label('except_error')
        except_return_label = code.new_label('except_return')
        try_return_label = code.new_label('try_return')
        try_break_label = code.new_label('try_break') if old_break_label else None
        try_continue_label = code.new_label('try_continue') if old_continue_label else None
        try_end_label = code.new_label('try_end')

        exc_save_vars = [code.funcstate.allocate_temp(py_object_type, False)
                         for _ in range(3)]
        save_exc = code.insertion_point()
        code.putln(
            "/*try:*/ {")
        code.return_label = try_return_label
        code.break_label = try_break_label
        code.continue_label = try_continue_label
        self.body.generate_execution_code(code)
        code.mark_pos(self.pos, trace=False)
        code.putln(
            "}")
        temps_to_clean_up = code.funcstate.all_free_managed_temps()
        can_raise = code.label_used(our_error_label)

        if can_raise:
            # inject code before the try block to save away the exception state
            code.globalstate.use_utility_code(reset_exception_utility_code)
            if not self.in_generator:
                save_exc.putln("__Pyx_PyThreadState_declare")
                save_exc.putln("__Pyx_PyThreadState_assign")
            save_exc.putln("__Pyx_ExceptionSave(%s);" % (
                ', '.join(['&%s' % var for var in exc_save_vars])))
            for var in exc_save_vars:
                save_exc.put_xgotref(var, py_object_type)

            def restore_saved_exception():
                for name in exc_save_vars:
                    code.put_xgiveref(name, py_object_type)
                code.putln("__Pyx_ExceptionReset(%s);" %
                           ', '.join(exc_save_vars))
        else:
            # try block cannot raise exceptions, but we had to allocate the temps above,
            # so just keep the C compiler from complaining about them being unused
            mark_vars_used = ["(void)%s;" % var for var in exc_save_vars]
            save_exc.putln("%s /* mark used */" % ' '.join(mark_vars_used))

            def restore_saved_exception():
                pass

        code.error_label = except_error_label
        code.return_label = except_return_label
        normal_case_terminates = self.body.is_terminator
        if self.else_clause:
            code.mark_pos(self.else_clause.pos)
            code.putln(
                "/*else:*/ {")
            self.else_clause.generate_execution_code(code)
            code.putln(
                "}")
            if not normal_case_terminates:
                normal_case_terminates = self.else_clause.is_terminator

        if can_raise:
            if not normal_case_terminates:
                for var in exc_save_vars:
                    code.put_xdecref_clear(var, py_object_type)
                code.put_goto(try_end_label)
            code.put_label(our_error_label)
            for temp_name, temp_type in temps_to_clean_up:
                code.put_xdecref_clear(temp_name, temp_type)

            if code.is_tracing():
                code.put_trace_exception_propagating()

            outer_except = code.funcstate.current_except
            # Currently points to self, but the ExceptClauseNode would also be ok. Change if needed.
            code.funcstate.current_except = self
            for except_clause in self.except_clauses:
                except_clause.generate_handling_code(code, except_end_label)
            code.funcstate.current_except = outer_except

            if not self.has_default_clause:
                code.put_goto(except_error_label)

        label_intercepts = code.label_interceptor(
            [except_error_label, try_break_label, try_continue_label, try_return_label, except_return_label],
            [old_error_label, old_break_label, old_continue_label, old_return_label, old_return_label],
            skip_to_label=try_end_label if not normal_case_terminates and not code.label_used(try_end_label) else None,
            pos=self.pos,
            trace=False,
        )

        for _ in label_intercepts:
            if can_raise:
                restore_saved_exception()

        if code.label_used(except_end_label):
            if not normal_case_terminates and not code.label_used(try_end_label):
                code.put_goto(try_end_label)
            code.put_label(except_end_label)
            if can_raise:
                restore_saved_exception()
        if code.label_used(try_end_label):
            code.put_label(try_end_label)
        code.putln("}")

        for cname in exc_save_vars:
            code.funcstate.release_temp(cname)

        code.return_label = old_return_label
        code.break_label = old_break_label
        code.continue_label = old_continue_label
        code.error_label = old_error_label

    def generate_function_definitions(self, env, code):
        self.body.generate_function_definitions(env, code)
        for except_clause in self.except_clauses:
            except_clause.generate_function_definitions(env, code)
        if self.else_clause is not None:
            self.else_clause.generate_function_definitions(env, code)

    def annotate(self, code):
        self.body.annotate(code)
        for except_node in self.except_clauses:
            except_node.annotate(code)
        if self.else_clause:
            self.else_clause.annotate(code)


class ExceptClauseNode(Node):
    #  Part of try ... except statement.
    #
    #  pattern        [ExprNode]
    #  target         ExprNode or None
    #  body           StatNode
    #  excinfo_target TupleNode(3*ResultRefNode) or None   optional target for exception info (not owned here!)
    #  match_flag     string             result of exception match
    #  exc_value      ExcValueNode       used internally
    #  function_name  string             qualified name of enclosing function
    #  exc_vars       (string * 3)       local exception variables
    #  is_except_as   bool               Py3-style "except ... as xyz"

    # excinfo_target is never set by the parser, but can be set by a transform
    # in order to extract more extensive information about the exception as a
    # sys.exc_info()-style tuple into a target variable

    child_attrs = ["pattern", "target", "body", "exc_value"]

    exc_value = None
    excinfo_target = None
    is_except_as = False

    def analyse_declarations(self, env):
        if self.target:
            self.target.analyse_target_declaration(env)
            from .ExprNodes import ExcValueNode
            self.exc_value = ExcValueNode(self.pos, self.infer_exception_type(env))
        self.body.analyse_declarations(env)

    def analyse_expressions(self, env):
        self.function_name = env.qualified_name
        if self.pattern:
            # normalise/unpack self.pattern into a list
            for i, pattern in enumerate(self.pattern):
                pattern = pattern.analyse_expressions(env)
                self.pattern[i] = pattern.coerce_to_pyobject(env)

        if self.target:
            self.target = self.target.analyse_target_expression(env, self.exc_value)

        self.body = self.body.analyse_expressions(env)
        return self

    def infer_exception_type(self, env):
        if self.pattern and len(self.pattern) == 1:
            # Infer target type for simple "except XyzError as exc".
            pattern = self.pattern[0]
            if pattern.is_name:
                entry = env.lookup(pattern.name)
                if entry and entry.is_type and entry.scope.is_builtin_scope:
                    return entry.type
        return Builtin.builtin_types["BaseException"]

    def body_may_need_exception(self):
        from .ParseTreeTransforms import HasNoExceptionHandlingVisitor
        tree_has_no_exceptions = HasNoExceptionHandlingVisitor()
        return not tree_has_no_exceptions(self.body)

    def generate_handling_code(self, code, end_label):
        code.mark_pos(self.pos)

        if self.pattern:
            has_non_literals = not all(
                pattern.is_literal or pattern.is_simple() and not pattern.result_in_temp()
                for pattern in self.pattern)

            if has_non_literals:
                # For non-trivial exception check expressions, hide the live exception from C-API calls.
                exc_vars = [code.funcstate.allocate_temp(py_object_type, manage_ref=True)
                            for _ in range(3)]
                code.globalstate.use_utility_code(UtilityCode.load_cached("PyErrFetchRestore", "Exceptions.c"))
                code.putln("__Pyx_ErrFetch(&%s, &%s, &%s);" % tuple(exc_vars))
                exc_type = exc_vars[0]
            else:
                exc_vars = exc_type = None

            for pattern in self.pattern:
                pattern.generate_evaluation_code(code)
            patterns = [pattern.py_result() for pattern in self.pattern]

            exc_tests = []
            if exc_type:
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached("FastTypeChecks", "ModuleSetupCode.c"))
                if len(patterns) == 2:
                    exc_tests.append("__Pyx_PyErr_GivenExceptionMatches2(%s, %s, %s)" % (
                        exc_type, patterns[0], patterns[1],
                    ))
                else:
                    exc_tests.extend(
                        "__Pyx_PyErr_GivenExceptionMatches(%s, %s)" % (exc_type, pattern)
                        for pattern in patterns
                    )
            elif len(patterns) == 2:
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached("FastTypeChecks", "ModuleSetupCode.c"))
                exc_tests.append("__Pyx_PyErr_ExceptionMatches2(%s, %s)" % (
                    patterns[0], patterns[1],
                ))
            else:
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached("PyErrExceptionMatches", "Exceptions.c"))
                exc_tests.extend(
                    "__Pyx_PyErr_ExceptionMatches(%s)" % pattern
                    for pattern in patterns
                )

            match_flag = code.funcstate.allocate_temp(PyrexTypes.c_int_type, manage_ref=False)
            code.putln("%s = %s;" % (match_flag, ' || '.join(exc_tests)))
            for pattern in self.pattern:
                pattern.generate_disposal_code(code)
                pattern.free_temps(code)

            if exc_vars:
                code.putln("__Pyx_ErrRestore(%s, %s, %s);" % tuple(exc_vars))
                code.putln(' '.join(["%s = 0;" % var for var in exc_vars]))
                for temp in exc_vars:
                    code.funcstate.release_temp(temp)

            code.putln(
                "if (%s) {" %
                    match_flag)
            code.funcstate.release_temp(match_flag)
        else:
            code.putln("/*except:*/ {")

        tracing = code.is_tracing()
        needs_exception = (
            self.target is not None or
            self.excinfo_target is not None or
            self.body_may_need_exception()
        )

        if needs_exception or tracing:
            code.put_add_traceback(self.function_name)

        if tracing:
            code.put_trace_exception_handled(self.pos)

        if needs_exception:
            # We always have to fetch the exception value even if
            # there is no target, because this also normalises the
            # exception and stores it in the thread state.
            code.globalstate.use_utility_code(get_exception_utility_code)
            exc_vars = [code.funcstate.allocate_temp(py_object_type, manage_ref=True)
                        for _ in range(3)]
            exc_args = "&%s, &%s, &%s" % tuple(exc_vars)
            code.putln("if (__Pyx_GetException(%s) < 0) %s" % (
                exc_args, code.error_goto(self.pos)))
            for var in exc_vars:
                code.put_xgotref(var, py_object_type)
        else:
            code.globalstate.use_utility_code(UtilityCode.load_cached("PyErrFetchRestore", "Exceptions.c"))
            code.putln("__Pyx_ErrRestore(0,0,0);")

        if tracing:
            code.putln("__Pyx_TraceExceptionDone();")

        if self.target:
            self.exc_value.set_var(exc_vars[1])
            self.exc_value.generate_evaluation_code(code)
            self.target.generate_assignment_code(self.exc_value, code)

        if self.excinfo_target is not None:
            for tempvar, node in zip(exc_vars, self.excinfo_target.args):
                node.set_var(tempvar)

        old_loop_labels = code.new_loop_labels("except_")

        if needs_exception:
            old_exc_vars = code.funcstate.exc_vars
            code.funcstate.exc_vars = exc_vars

        self.body.generate_execution_code(code)

        if needs_exception:
            code.funcstate.exc_vars = old_exc_vars

        if not self.body.is_terminator:
            if needs_exception:
                for var in exc_vars:
                    # FIXME: XDECREF() is needed to allow re-raising (which clears the exc_vars),
                    # but I don't think it's the right solution.
                    code.put_xdecref_clear(var, py_object_type)
            code.put_goto(end_label)

        if needs_exception:
            for _ in code.label_interceptor(code.get_loop_labels(), old_loop_labels):
                code.put_decref_clear(exc_vars[0], py_object_type)
                code.put_decref_clear(exc_vars[1], py_object_type)
                # Traceback may be NULL.
                code.put_xdecref_clear(exc_vars[2], py_object_type)

            for temp in exc_vars:
                code.funcstate.release_temp(temp)

        code.set_loop_labels(old_loop_labels)

        code.putln(
            "}")

    def generate_function_definitions(self, env, code):
        if self.target is not None:
            self.target.generate_function_definitions(env, code)
        self.body.generate_function_definitions(env, code)

    def annotate(self, code):
        if self.pattern:
            for pattern in self.pattern:
                pattern.annotate(code)
        if self.target:
            self.target.annotate(code)
        self.body.annotate(code)


class TryFinallyStatNode(StatNode):
    #  try ... finally statement
    #
    #  body             StatNode
    #  finally_clause   StatNode
    #  finally_except_clause  deep-copy of finally_clause for exception case
    #  in_generator     inside of generator => must store away current exception also in return case
    #
    #  Each of the continue, break, return and error gotos runs
    #  into its own deep-copy of the finally block code.
    #  In addition, if we're doing an error, we save the
    #  exception on entry to the finally block and restore
    #  it on exit.

    child_attrs = ["body", "finally_clause", "finally_except_clause"]

    preserve_exception = 1

    # handle exception case, in addition to return/break/continue
    handle_error_case = True
    func_return_type = None
    finally_except_clause = None

    is_try_finally_in_nogil = False
    in_generator = False

    @staticmethod
    def create_analysed(pos, env, body, finally_clause):
        node = TryFinallyStatNode(pos, body=body, finally_clause=finally_clause)
        return node

    def analyse_declarations(self, env):
        self.body.analyse_declarations(env)
        self.finally_except_clause = copy.deepcopy(self.finally_clause)
        self.finally_except_clause.analyse_declarations(env)
        self.finally_clause.analyse_declarations(env)

    def analyse_expressions(self, env):
        self.body = self.body.analyse_expressions(env)
        self.finally_clause = self.finally_clause.analyse_expressions(env)
        self.finally_except_clause = self.finally_except_clause.analyse_expressions(env)
        if env.return_type and not env.return_type.is_void:
            self.func_return_type = env.return_type
        return self

    nogil_check = Node.gil_error
    gil_message = "Try-finally statement"

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)  # before changing the error label, in case of tracing errors
        code.putln("/*try:*/ {")

        old_error_label = code.error_label
        old_labels = code.all_new_labels()
        new_labels = code.get_all_labels()
        new_error_label = code.error_label
        if not self.handle_error_case:
            code.error_label = old_error_label
        catch_label = code.new_label()

        self.body.generate_execution_code(code)

        code.putln("}")

        temps_to_clean_up = code.funcstate.all_free_managed_temps()
        code.mark_pos(self.finally_clause.pos)
        code.putln("/*finally:*/ {")

        # Reset labels only after writing out a potential line trace call for correct nogil error handling.
        code.set_all_labels(old_labels)

        def fresh_finally_clause(_next=[self.finally_clause]):
            # generate the original subtree once and always keep a fresh copy
            node = _next[0]
            node_copy = copy.deepcopy(node)
            if node is self.finally_clause:
                _next[0] = node_copy
            else:
                node = node_copy
            return node

        preserve_error = self.preserve_exception and code.label_used(new_error_label)
        needs_success_cleanup = not self.finally_clause.is_terminator

        if not self.body.is_terminator:
            code.putln('/*normal exit:*/{')
            fresh_finally_clause().generate_execution_code(code)
            if not self.finally_clause.is_terminator:
                code.put_goto(catch_label)
            code.putln('}')

        if preserve_error:
            code.put_label(new_error_label)
            code.putln('/*exception exit:*/{')
            if not self.in_generator:
                code.putln("__Pyx_PyThreadState_declare")
            if self.is_try_finally_in_nogil:
                code.declare_gilstate()
            if needs_success_cleanup:
                exc_lineno_cnames = tuple([
                    code.funcstate.allocate_temp(PyrexTypes.c_int_type, manage_ref=False)
                    for _ in range(2)])
                exc_filename_cname = code.funcstate.allocate_temp(
                    PyrexTypes.CPtrType(PyrexTypes.c_const_type(PyrexTypes.c_char_type)),
                    manage_ref=False)
            else:
                exc_lineno_cnames = exc_filename_cname = None
            exc_vars = tuple([
                code.funcstate.allocate_temp(py_object_type, manage_ref=False)
                for _ in range(6)])

            if code.is_tracing():
                code.put_trace_exception_propagating()
                code.put_trace_exception_handled(self.pos)
            self.put_error_catcher(
                code, temps_to_clean_up, exc_vars, exc_lineno_cnames, exc_filename_cname)
            finally_old_labels = code.all_new_labels()

            code.putln('{')
            old_exc_vars = code.funcstate.exc_vars
            code.funcstate.exc_vars = exc_vars[:3]
            self.finally_except_clause.generate_execution_code(code)
            code.funcstate.exc_vars = old_exc_vars
            code.putln('}')

            if needs_success_cleanup:
                self.put_error_uncatcher(code, exc_vars, exc_lineno_cnames, exc_filename_cname)
                if exc_lineno_cnames:
                    for cname in exc_lineno_cnames:
                        code.funcstate.release_temp(cname)
                if exc_filename_cname:
                    code.funcstate.release_temp(exc_filename_cname)
                if code.is_tracing():
                    code.put_trace_exception(self.pos, reraise=True)
                code.put_goto(old_error_label)

            for _ in code.label_interceptor(code.get_all_labels(), finally_old_labels):
                self.put_error_cleaner(code, exc_vars)

            for cname in exc_vars:
                code.funcstate.release_temp(cname)
            code.putln('}')

        code.set_all_labels(old_labels)
        return_label = code.return_label
        exc_vars = ()

        # TODO: use code.label_interceptor()?
        for i, (new_label, old_label) in enumerate(zip(new_labels, old_labels)):
            if not code.label_used(new_label):
                continue
            if new_label == new_error_label and preserve_error:
                continue  # handled above

            code.putln('%s: {' % new_label)
            ret_temp = None
            if old_label == return_label:
                if not self.finally_clause.is_terminator:
                    # store away return value for later reuse
                    if (self.func_return_type and
                            not self.is_try_finally_in_nogil and
                            not isinstance(self.finally_clause, GILExitNode)):
                        ret_temp = code.funcstate.allocate_temp(
                            self.func_return_type, manage_ref=False)
                        code.putln("%s = %s;" % (ret_temp, Naming.retval_cname))
                        if self.func_return_type.is_pyobject:
                            code.putln("%s = 0;" % Naming.retval_cname)

            fresh_finally_clause().generate_execution_code(code)

            if old_label == return_label:
                if ret_temp:
                    code.putln("%s = %s;" % (Naming.retval_cname, ret_temp))
                    if self.func_return_type.is_pyobject:
                        code.putln("%s = 0;" % ret_temp)
                    code.funcstate.release_temp(ret_temp)

            if not self.finally_clause.is_terminator:
                code.put_goto(old_label)
            code.putln('}')

        # End finally
        code.put_label(catch_label)
        code.putln(
            "}")

    def generate_function_definitions(self, env, code):
        self.body.generate_function_definitions(env, code)
        self.finally_clause.generate_function_definitions(env, code)
        if self.finally_except_clause:
            self.finally_except_clause.generate_function_definitions(env, code)

    def put_error_catcher(self, code, temps_to_clean_up, exc_vars,
                          exc_lineno_cnames=None, exc_filename_cname=None):
        code.globalstate.use_utility_code(restore_exception_utility_code)
        code.globalstate.use_utility_code(get_exception_utility_code)
        code.globalstate.use_utility_code(swap_exception_utility_code)

        if self.is_try_finally_in_nogil:
            code.put_ensure_gil(declare_gilstate=False)
        code.putln("__Pyx_PyThreadState_assign")

        code.putln(' '.join(["%s = 0;" % var for var in exc_vars]))
        for temp_name, type in temps_to_clean_up:
            code.put_xdecref_clear(temp_name, type)

        # not using preprocessor here to avoid warnings about
        # unused utility functions and/or temps
        code.putln(" __Pyx_ExceptionSwap(&%s, &%s, &%s);" % exc_vars[3:])
        code.putln("if ("
                   # if __Pyx_GetException() fails,
                   # store the newly raised exception instead
                   " unlikely(__Pyx_GetException(&%s, &%s, &%s) < 0)) "
                   "__Pyx_ErrFetch(&%s, &%s, &%s);" % (exc_vars[:3] * 2))
        for var in exc_vars:
            code.put_xgotref(var, py_object_type)
        if exc_lineno_cnames:
            code.putln("%s = %s; %s = %s; %s = %s;" % (
                exc_lineno_cnames[0], Naming.lineno_cname,
                exc_lineno_cnames[1], Naming.clineno_cname,
                exc_filename_cname, Naming.filename_cname))

        if self.is_try_finally_in_nogil:
            code.put_release_ensured_gil()

    def put_error_uncatcher(self, code, exc_vars, exc_lineno_cnames=None, exc_filename_cname=None):
        code.globalstate.use_utility_code(restore_exception_utility_code)
        code.globalstate.use_utility_code(reset_exception_utility_code)

        if self.is_try_finally_in_nogil:
            code.put_ensure_gil(declare_gilstate=False)
            # although the thread state is already assigned, that can't be trusted after releasing the GIL
            code.putln("__Pyx_PyThreadState_assign")

        # not using preprocessor here to avoid warnings about
        # unused utility functions and/or temps
        for var in exc_vars[3:]:
            code.put_xgiveref(var, py_object_type)
        code.putln("__Pyx_ExceptionReset(%s, %s, %s);" % exc_vars[3:])
        for var in exc_vars[:3]:
            code.put_xgiveref(var, py_object_type)
        code.putln("__Pyx_ErrRestore(%s, %s, %s);" % exc_vars[:3])

        if self.is_try_finally_in_nogil:
            code.put_release_ensured_gil()

        code.putln(' '.join(["%s = 0;" % var for var in exc_vars]))
        if exc_lineno_cnames:
            code.putln("%s = %s; %s = %s; %s = %s;" % (
                Naming.lineno_cname, exc_lineno_cnames[0],
                Naming.clineno_cname, exc_lineno_cnames[1],
                Naming.filename_cname, exc_filename_cname))

    def put_error_cleaner(self, code, exc_vars):
        code.globalstate.use_utility_code(reset_exception_utility_code)
        if self.is_try_finally_in_nogil:
            code.put_ensure_gil(declare_gilstate=False)
            # although the thread state is already assigned, that can't be trusted after releasing the GIL
            code.putln("__Pyx_PyThreadState_assign")

        # not using preprocessor here to avoid warnings about
        # unused utility functions and/or temps
        for var in exc_vars[3:]:
            code.put_xgiveref(var, py_object_type)
        code.putln("__Pyx_ExceptionReset(%s, %s, %s);" % exc_vars[3:])
        for var in exc_vars[:3]:
            code.put_xdecref_clear(var, py_object_type)
        if self.is_try_finally_in_nogil:
            code.put_release_ensured_gil()
        code.putln(' '.join(["%s = 0;"]*3) % exc_vars[3:])

    def annotate(self, code):
        self.body.annotate(code)
        self.finally_clause.annotate(code)


class NogilTryFinallyStatNode(TryFinallyStatNode):
    """
    A try/finally statement that may be used in nogil code sections.
    """

    preserve_exception = False
    nogil_check = None


class GILStatNode(NogilTryFinallyStatNode):
    #  'with gil' or 'with nogil' statement
    #
    #   state   string   'gil' or 'nogil'
    #   scope_gil_state_known  bool  For nogil functions this can be False, since they can also be run with gil
    #                           set to False by GilCheck transform

    child_attrs = ["condition"] + NogilTryFinallyStatNode.child_attrs
    state_temp = None
    scope_gil_state_known = True

    def __init__(self, pos, state, body, condition=None):
        self.state = state
        self.condition = condition
        self.create_state_temp_if_needed(pos, state, body)
        TryFinallyStatNode.__init__(
            self, pos,
            body=body,
            finally_clause=GILExitNode(
                pos, state=state, state_temp=self.state_temp))

    def create_state_temp_if_needed(self, pos, state, body):
        from .ParseTreeTransforms import YieldNodeCollector
        collector = YieldNodeCollector()
        collector.visitchildren(body)
        if not collector.yields:
            return

        if state == 'gil':
            temp_type = PyrexTypes.c_gilstate_type
        else:
            temp_type = PyrexTypes.c_threadstate_ptr_type
        from . import ExprNodes
        self.state_temp = ExprNodes.TempNode(pos, temp_type)

    def analyse_declarations(self, env):
        env._in_with_gil_block = (self.state == 'gil')
        if self.state == 'gil':
            env.has_with_gil_block = True

        if self.condition is not None:
            self.condition.analyse_declarations(env)

        return super().analyse_declarations(env)

    def analyse_expressions(self, env):
        env.use_utility_code(
            UtilityCode.load_cached("ForceInitThreads", "ModuleSetupCode.c"))

        if self.condition is not None:
            self.condition = self.condition.analyse_expressions(env)

        was_nogil = env.nogil
        env.nogil = self.state == 'nogil'
        node = TryFinallyStatNode.analyse_expressions(self, env)
        env.nogil = was_nogil
        return node

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        code.begin_block()
        if self.state_temp:
            # state-temps only happen inside generators which are inherently Python functions
            # and thus we do always know whether we have the GIL. This is important because it
            # means that the type of the state-temp is always PyThreadState*.
            assert self.scope_gil_state_known
            self.state_temp.allocate(code)
            variable = self.state_temp.result()
        else:
            variable = None

        old_gil_config = code.funcstate.gil_owned
        if self.state == 'gil':
            code.put_ensure_gil(variable=variable)
            code.funcstate.gil_owned = True
        else:
            code.put_release_gil(variable=variable, unknown_gil_state=not self.scope_gil_state_known)
            code.funcstate.gil_owned = False

        TryFinallyStatNode.generate_execution_code(self, code)

        if self.state_temp:
            self.state_temp.release(code)

        code.funcstate.gil_owned = old_gil_config
        code.end_block()


class GILExitNode(StatNode):
    """
    Used as the 'finally' block in a GILStatNode

    state   string   'gil' or 'nogil'
    #   scope_gil_state_known  bool  For nogil functions this can be False, since they can also be run with gil
    #                           set to False by GilCheck transform
    """

    child_attrs = []
    state_temp = None
    scope_gil_state_known = True

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        if self.state_temp:
            variable = self.state_temp.result()
        else:
            variable = None

        if self.state == 'gil':
            code.put_release_ensured_gil(variable)
        else:
            code.put_acquire_gil(variable, unknown_gil_state=not self.scope_gil_state_known)


class EnsureGILNode(GILExitNode):
    """
    Ensure the GIL in nogil functions for cleanup before returning.
    """

    def generate_execution_code(self, code):
        code.put_ensure_gil(declare_gilstate=False)


class CriticalSectionStatNode(TryFinallyStatNode):
    """
    Represents a freethreading Python critical section.
    In non-freethreading Python, this is a no-op.

    args    list of ExprNode    1 or 2 elements, must be object, pymutex or pymutex*
    """

    child_attrs = ["args"] + TryFinallyStatNode.child_attrs

    var_type = None
    preserve_exception = False
    is_pymutex_critical_section = False

    def __init__(self, pos, /, args, body, **kwds):
        if len(args) > 1:
            self.var_type = PyrexTypes.c_py_critical_section2_type
        else:
            self.var_type = PyrexTypes.c_py_critical_section_type

        self.length_tag = str(len(args)) if len(args) > 1 else ""

        super().__init__(
            pos,
            args=args,
            body=body,
            finally_clause=CriticalSectionExitNode(
                pos, length_tag=self.length_tag),
            **kwds,
        )

    def check_for_yields(self):
        from .ParseTreeTransforms import YieldNodeCollector
        collector = YieldNodeCollector()
        collector.visitchildren(self.body)
        if collector.yields:
            error(self.pos, f"Cannot yield while in a cython.critical_section.")

    def analyse_declarations(self, env):
        for arg in self.args:
            arg.analyse_declarations(env)
        return super().analyse_declarations(env)

    def analyse_expressions(self, env):
        self.check_for_yields()
        cy_pymutex_type = PyrexTypes.get_cy_pymutex_type()
        mutex_count = 0
        for i, arg in enumerate(self.args):
            arg = arg.analyse_expressions(env)
            if (arg.type == cy_pymutex_type or (
                    arg.type.is_ptr and arg.type.base_type == cy_pymutex_type)):
                mutex_count += 1
                self.is_pymutex_critical_section = True
            elif arg.type.is_pyobject:
                # Coerce to temp because it's a bit of a disaster if the argument is destroyed
                # while we're working on it, and the Python critical section implementation
                # doesn't ensure this.
                # TODO - we could potentially be a bit smarter about this, and avoid
                # it for local variables that we know are never re-assigned.
                arg = arg.coerce_to_temp(env)
            else:
                # Note - deliberately no coercion to Python object.
                # Critical sections only really make sense on a specific known Python object,
                # so using them on coerced Python objects is very unlikely to make sense.
                error(
                    arg.pos,
                    "Arguments to cython.critical_section must be Python objects, pymutex, or pymutex*."
                )
            self.args[i] = arg
        if mutex_count != 0 and mutex_count != len(self.args):
            error(
                self.pos,
                "Arguments to cython.critical_section must not mix objects and pymutexes."
            )
        return super().analyse_expressions(env)

    def generate_execution_code(self, code):
        if self.is_pymutex_critical_section:
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("CriticalSectionsMutex", "Synchronization.c"))
            mutex = "Mutex"
        else:
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("CriticalSections", "Synchronization.c"))
            mutex = ""

        code.mark_pos(self.pos)
        code.begin_block()
        variable = Naming.critical_section_variable
        code.putln(f"{self.var_type.declaration_code(variable)};")

        for arg in self.args:
            arg.generate_evaluation_code(code)
        if self.is_pymutex_critical_section:
            args = [ f"{'' if arg.type.is_ptr else '&'}{arg.result()}" for arg in self.args ]
        else:
            args = [ f"(PyObject*){arg.result()}" for arg in self.args ]
        code.putln(
            f"__Pyx_PyCriticalSection{self.length_tag}_Begin{mutex}(&{variable}, {', '.join(args)});"
        )

        TryFinallyStatNode.generate_execution_code(self, code)

        for arg in self.args:
            arg.generate_disposal_code(code)
            arg.free_temps(code)

        code.end_block()

    def nogil_check(self, env):
        error(self.pos, "Critical sections require the GIL")


class CriticalSectionExitNode(StatNode):
    """
    critical_section - the CriticalSectionStatNode that owns this
    """
    child_attrs = []
    uptree_ref_attrs = ["critical_section"]

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        code.putln(
            f"__Pyx_PyCriticalSection{self.length_tag}_End(&{ Naming.critical_section_variable});"
        )

class CythonLockStatNode(TryFinallyStatNode):
    """
    Represents
        with l:
            ...
    where l in a cython.pymutex or cython.pythread_type_lock.

    arg    ExprNode
    """

    child_attrs = ["arg"] + TryFinallyStatNode.child_attrs

    lock_temp = None

    preserve_exception = False  # No need to save/restore exception state to release the lock
    nogil_check = None

    @classmethod
    def from_withstat(cls, node):
        from . import ExprNodes

        assert isinstance(node.body, TryFinallyStatNode)
        assert isinstance(node.body.body, TryExceptStatNode)
        result = cls(
            node.pos,
            arg=node.manager,
            body=node.body.body.body,
            finally_clause = CythonLockExitNode(
                node.pos
            ),
            lock_temp = ExprNodes.TempNode(node.pos, PyrexTypes.CPtrType(node.manager.type))
        )
        result.finally_clause.lock_stat_node = result
        result.finally_except_clause = result.finally_clause
        return result

    def analyse_declarations(self, env):
        self.arg.analyse_declarations(env)
        return super().analyse_declarations(env)

    def analyse_expressions(self, env):
        self.arg = self.arg.analyse_expressions(env)
        body = self.body
        if isinstance(body, StatListNode) and len(body.stats) >= 1:
            body = body.stats[0]
        return super().analyse_expressions(env)

    def generate_execution_code(self, code):
        code.globalstate.use_utility_code(self.arg.type.get_usage_utility_code())

        code.mark_pos(self.pos)
        code.begin_block()

        self.lock_temp.allocate(code)
        temp_name = self.lock_temp.result()
        self.arg.generate_evaluation_code(code)
        code.putln(f"{temp_name} = &{self.arg.result()};")
        if self.in_nogil_context == NoGilState.NoGil:
            gil_str = "Nogil"
        elif self.in_nogil_context == NoGilState.NoGilScope:
            gil_str = ""
        else:
            gil_str = "Gil"

        code.putln(f"__Pyx_Locks_{self.arg.type.cname_part}_Lock{gil_str}(*{temp_name});")

        TryFinallyStatNode.generate_execution_code(self, code)

        self.arg.generate_disposal_code(code)
        self.arg.free_temps(code)

        self.lock_temp.release(code)

        code.end_block()


class CythonLockExitNode(StatNode, CopyWithUpTreeRefsMixin):
    """
    lock_stat_node   CythonLockStatNode   the associated with block
    """
    child_attrs = []
    uptree_ref_attrs = ["lock_stat_node"]

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        cname_part = self.lock_stat_node.arg.type.cname_part
        code.putln(f"__Pyx_Locks_{cname_part}_Unlock(*{self.lock_stat_node.lock_temp.result()});")


def cython_view_utility_code(options):
    from . import MemoryView
    return MemoryView.get_view_utility_code(options.shared_utility_qualified_name)


utility_code_for_cimports = {
    # utility code (or inlining c) in a pxd (or pyx) file.
    # TODO: Consider a generic user-level mechanism for importing
    'cpython.array'         : lambda options: UtilityCode.load_cached("ArrayAPI", "arrayarray.h"),
    'cpython.array.array'   : lambda options: UtilityCode.load_cached("ArrayAPI", "arrayarray.h"),
    'cython.view'           : cython_view_utility_code,
}

def cimport_numpy_check(node, code):
    # shared code between CImportStatNode and FromCImportStatNode
    # check to ensure that import_array is called
    for mod in code.globalstate.module_node.scope.cimported_modules:
        if mod.name != node.module_name:
            continue
        # there are sometimes several cimported modules with the same name
        # so complete the loop if necessary
        import_array = mod.lookup_here("import_array")
        _import_array = mod.lookup_here("_import_array")
        # at least one entry used
        used = (import_array and import_array.used) or (_import_array and _import_array.used)
        if ((import_array or _import_array)  # at least one entry found
                and not used):
            # sanity check that this is actually numpy and not a user pxd called "numpy"
            if _import_array and _import_array.type.is_cfunction:
                # warning is mainly for the sake of testing
                warning(node.pos, "'numpy.import_array()' has been added automatically "
                        "since 'numpy' was cimported but 'numpy.import_array' was not called.", 0)
                code.globalstate.use_utility_code(
                    UtilityCode.load_cached("NumpyImportArray", "NumpyImportArray.c")
                )
                return  # no need to continue once the utility code is added


class CImportStatNode(StatNode):
    #  cimport statement
    #
    #  module_name   string           Qualified name of module being imported
    #  as_name       string or None   Name specified in "as" clause, if any
    #  is_absolute   bool             True for absolute imports, False otherwise

    child_attrs = []
    is_absolute = False

    def analyse_declarations(self, env):
        if not env.is_module_scope:
            error(self.pos, "cimport only allowed at module level")
            return
        module_scope = env.find_module(
            self.module_name, self.pos, relative_level=0 if self.is_absolute else -1)
        if "." in self.module_name:
            names = [EncodedString(name) for name in self.module_name.split(".")]
            top_name = names[0]
            top_module_scope = env.context.find_submodule(top_name)
            module_scope = top_module_scope
            for name in names[1:]:
                submodule_scope = module_scope.find_submodule(name)
                module_scope.declare_module(name, submodule_scope, self.pos)
                module_scope = submodule_scope
            if self.as_name:
                env.declare_module(self.as_name, module_scope, self.pos)
            else:
                env.add_imported_module(module_scope)
                env.declare_module(top_name, top_module_scope, self.pos)
        else:
            name = self.as_name or self.module_name
            entry = env.declare_module(name, module_scope, self.pos)
            entry.known_standard_library_import = self.module_name
        if self.module_name in utility_code_for_cimports:
            env.use_utility_code(utility_code_for_cimports[self.module_name](env.context.options))

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        if self.module_name == "numpy":
            cimport_numpy_check(self, code)


class FromCImportStatNode(StatNode):
    #  from ... cimport statement
    #
    #  module_name     string                        Qualified name of module
    #  relative_level  int or None                   Relative import: number of dots before module_name
    #  imported_names  [(pos, name, as_name)]  Names to be imported

    child_attrs = []
    module_name = None
    relative_level = None
    imported_names = None

    def analyse_declarations(self, env):
        if not env.is_module_scope:
            error(self.pos, "cimport only allowed at module level")
            return
        qualified_name_components = env.qualified_name.count('.') + 1
        if self.relative_level:
            if self.relative_level > qualified_name_components:
                # 1. case: importing beyond package: from .. import pkg
                error(self.pos, "relative cimport beyond main package is not allowed")
                return
            elif self.relative_level == qualified_name_components and not env.is_package:
                # 2. case: importing from same level but current dir is not package: from . import module
                error(self.pos, "relative cimport from non-package directory is not allowed")
                return
        module_scope = env.find_module(self.module_name, self.pos, relative_level=self.relative_level)
        if not module_scope:
            return
        module_name = module_scope.qualified_name
        env.add_imported_module(module_scope)
        for pos, name, as_name in self.imported_names:
            if name == "*":
                for local_name, entry in list(module_scope.entries.items()):
                    env.add_imported_entry(local_name, entry, pos)
            else:
                entry = module_scope.lookup(name)
                if entry:
                    entry.used = 1
                else:
                    is_relative_import = self.relative_level is not None and self.relative_level > 0
                    submodule_scope = env.context.find_module(
                        name, from_module=module_scope, pos=self.pos, absolute_fallback=False, relative_import=is_relative_import)
                    if not submodule_scope:
                        continue
                    if submodule_scope.parent_module is module_scope:
                        env.declare_module(as_name or name, submodule_scope, self.pos)
                    else:
                        error(pos, "Name '%s' not declared in module '%s'" % (name, module_name))

                if entry:
                    local_name = as_name or name
                    env.add_imported_entry(local_name, entry, pos)

        if module_name.startswith('cpython') or module_name.startswith('cython'):  # enough for now
            if module_name in utility_code_for_cimports:
                env.use_utility_code(utility_code_for_cimports[module_name](env.context.options))
            for _, name, _ in self.imported_names:
                fqname = '%s.%s' % (module_name, name)
                if fqname in utility_code_for_cimports:
                    env.use_utility_code(utility_code_for_cimports[fqname](env.context.options))

    def declaration_matches(self, entry, kind):
        if not entry.is_type:
            return 0
        type = entry.type
        if kind == 'class':
            if not type.is_extension_type:
                return 0
        else:
            if not type.is_struct_or_union:
                return 0
            if kind != type.kind:
                return 0
        return 1

    def analyse_expressions(self, env):
        return self

    def generate_execution_code(self, code):
        if self.module_name == "numpy":
            cimport_numpy_check(self, code)


class FromImportStatNode(StatNode):
    #  from ... import statement
    #
    #  module           ImportNode
    #  items            [(string, NameNode)]
    #  interned_items   [(string, NameNode, ExprNode)]
    #  item             PyTempNode            used internally
    #  import_star      boolean               used internally

    child_attrs = ["module"]
    import_star = 0

    def analyse_declarations(self, env):
        for name, target in self.items:
            if name == "*":
                if not env.is_module_scope:
                    error(self.pos, "import * only allowed at module level")
                    return
                env.has_import_star = 1
                self.import_star = 1
            else:
                target.analyse_target_declaration(env)
                if target.entry:
                    if target.get_known_standard_library_import() is None:
                        target.entry.known_standard_library_import = EncodedString(
                            "%s.%s" % (self.module.module_name.value, name))
                else:
                    # it isn't unambiguous
                    target.entry.known_standard_library_import = ""


    def analyse_expressions(self, env):
        from . import ExprNodes
        self.module = self.module.analyse_expressions(env)
        self.item = ExprNodes.RawCNameExprNode(self.pos, py_object_type)
        self.interned_items = []
        for name, target in self.items:
            if name == '*':
                for _, entry in env.entries.items():
                    if not entry.is_type and entry.type.is_extension_type:
                        env.use_utility_code(UtilityCode.load_cached("ExtTypeTest", "ObjectHandling.c"))
                        break
            else:
                entry = env.lookup(target.name)
                # check whether or not entry is already cimported
                if (entry.is_type and entry.type.name == name
                        and hasattr(entry.type, 'module_name')):
                    if entry.type.module_name == self.module.module_name.value:
                        # cimported with absolute name
                        continue
                    try:
                        # cimported with relative name
                        module = env.find_module(self.module.module_name.value, pos=self.pos,
                                                 relative_level=self.module.level)
                        if entry.type.module_name == module.qualified_name:
                            continue
                    except AttributeError:
                        pass
                target = target.analyse_target_expression(env, None)  # FIXME?
                if target.type is py_object_type:
                    coerced_item = None
                else:
                    coerced_item = self.item.coerce_to(target.type, env)
                self.interned_items.append((name, target, coerced_item))
        return self

    def generate_execution_code(self, code):
        code.mark_pos(self.pos)
        self.module.generate_evaluation_code(code)
        if self.import_star:
            code.putln(
                'if (%s(%s) < 0) %s;' % (
                    Naming.import_star,
                    self.module.py_result(),
                    code.error_goto(self.pos)))

        if self.interned_items:
            code.putln("{")
            code.globalstate.use_utility_code(
                UtilityCode.load_cached("ImportFrom", "ImportExport.c"))

            counter_var = code.funcstate.allocate_temp(PyrexTypes.c_py_ssize_t_type, manage_ref=False)
            item_temp = code.funcstate.allocate_temp(py_object_type, manage_ref=True)
            self.item.set_cname(item_temp)

            imported_names = [
                code.intern_identifier(name)
                for name, _, _ in self.interned_items
            ]
            code.putln(f"PyObject* const __pyx_imported_names[] = {{{','.join(imported_names)}}};")

            # Special-case Python globals: they are simple enough to handle them jointly in the loop.
            simple_pyglobals = []
            direct_assignments = []
            coerced_assignments = []

            for i, (name, target, coerced_item) in enumerate(self.interned_items):
                if coerced_item is not None:
                    coerced_assignments.append((i, name, target, coerced_item))
                    continue
                if target.is_name and target.name == name:
                    if target.entry and target.entry.is_pyglobal and target.entry.scope.is_module_scope:
                        simple_pyglobals.append(i)
                        continue
                direct_assignments.append((i, name, target))

            needs_specific_assignments = bool(direct_assignments or coerced_assignments)

            if len(imported_names) > 1:
                code.putln(f"for ({counter_var}=0; {counter_var} < {len(imported_names)}; {counter_var}++) {{")
            else:
                # Avoid the for-loop code if we have only one name to import.
                code.putln(f"{counter_var} = 0; {{")

            code.putln(
                f'{item_temp} = __Pyx_ImportFrom({self.module.py_result()}, __pyx_imported_names[{counter_var}]); '
                f'{code.error_goto_if_null(item_temp, self.pos)}'
            )
            code.put_gotref(item_temp, py_object_type)

            # Put specific (C-)assignments into switch-cases (if any) and leave generic Python globals as default.
            if needs_specific_assignments:
                code.putln(f"switch ({counter_var}) {{")

                for i, name, target in direct_assignments:
                    code.putln(f"case {i}:")
                    target.generate_assignment_code(self.item, code)
                    code.putln("break;")

                for i, name, target, coerced_item in coerced_assignments:
                    code.putln(f"case {i}:")
                    coerced_item.generate_evaluation_code(code)
                    target.generate_assignment_code(coerced_item, code)
                    code.putln("break;")

                code.putln("default:;")

            if simple_pyglobals:
                module_dict = code.name_in_module_state(Naming.moddict_cname)
                code.put_error_if_neg(
                    self.pos,
                    f"PyDict_SetItem({module_dict}, __pyx_imported_names[{counter_var}], {item_temp})")

            if needs_specific_assignments:
                code.putln("}")  # switch

            code.put_decref_clear(item_temp, py_object_type)
            code.putln("}")  # for

            code.funcstate.release_temp(item_temp)
            code.funcstate.release_temp(counter_var)
            code.putln("}")

        self.module.generate_disposal_code(code)
        self.module.free_temps(code)


class ParallelNode(Node):
    """
    Base class for cython.parallel constructs.
    """

    nogil_check = None


class ParallelStatNode(StatNode, ParallelNode):
    """
    Base class for 'with cython.parallel.parallel():' and 'for i in prange():'.

    assignments     { Entry(var) : (var.pos, inplace_operator_or_None) }
                    assignments to variables in this parallel section

    parent          parent ParallelStatNode or None
    is_parallel     indicates whether this node is OpenMP parallel
                    (true for #pragma omp parallel for and
                              #pragma omp parallel)

    is_parallel is true for:

        #pragma omp parallel
        #pragma omp parallel for

    sections, but NOT for

        #pragma omp for

    We need this to determine the sharing attributes.

    privatization_insertion_point   a code insertion point used to make temps
                                    private (esp. the "nsteps" temp)

    args         tuple          the arguments passed to the parallel construct
    kwargs       DictNode       the keyword arguments passed to the parallel
                                construct (replaced by its compile time value)
    """

    child_attrs = ['body', 'num_threads', 'threading_condition']

    body = None

    is_prange = False
    is_nested_prange = False

    error_label_used = False

    num_threads = None
    chunksize = None
    threading_condition = None

    parallel_exc = (
        Naming.parallel_exc_type,
        Naming.parallel_exc_value,
        Naming.parallel_exc_tb,
    )

    parallel_pos_info = (
        Naming.parallel_filename,
        Naming.parallel_lineno,
        Naming.parallel_clineno,
    )

    pos_info = (
        Naming.filename_cname,
        Naming.lineno_cname,
        Naming.clineno_cname,
    )

    # Note that this refers to openmp critical sections, not freethreading
    # Python critical sections.
    critical_section_counter = 0

    def __init__(self, pos, **kwargs):
        super().__init__(pos, **kwargs)

        # All assignments in this scope
        self.assignments = kwargs.get('assignments') or {}

        # All seen closure cnames and their temporary cnames
        self.seen_closure_vars = set()

        # Dict of variables that should be declared (first|last|)private or
        # reduction { Entry: op }.
        # If op is not None, it's a reduction.
        self.privates = {}

        # [NameNode]
        self.assigned_nodes = []

    def analyse_declarations(self, env):
        self.body.analyse_declarations(env)

        self.num_threads = None
        self.threading_condition = None

        if self.kwargs:
            # Try to find known keyword arguments.
            pairs = []
            seen = set()
            for dictitem in self.kwargs.key_value_pairs:
                if dictitem.key.value in seen:
                    error(self.pos, "Duplicate keyword argument found: %s" % dictitem.key.value)
                seen.add(dictitem.key.value)
                if dictitem.key.value == 'num_threads':
                    if not dictitem.value.is_none:
                        self.num_threads = dictitem.value
                elif dictitem.key.value == 'use_threads_if':
                    if not dictitem.value.is_none:
                        self.threading_condition = dictitem.value
                elif self.is_prange and dictitem.key.value == 'chunksize':
                    if not dictitem.value.is_none:
                        self.chunksize = dictitem.value
                else:
                    pairs.append(dictitem)

            self.kwargs.key_value_pairs = pairs

            try:
                self.kwargs = self.kwargs.compile_time_value(env)
            except Exception as e:
                error(self.kwargs.pos, "Only compile-time values may be "
                                       "supplied as keyword arguments")
        else:
            self.kwargs = {}

        for kw, val in self.kwargs.items():
            if kw not in self.valid_keyword_arguments:
                error(self.pos, "Invalid keyword argument: %s" % kw)
            else:
                setattr(self, kw, val)

    def analyse_expressions(self, env):
        if self.num_threads:
            self.num_threads = self.num_threads.analyse_expressions(env)

        if self.threading_condition:
            if self.is_parallel:
                self.threading_condition = self.threading_condition.analyse_expressions(env)
            else:
                error(self.pos, "'use_threads_if' must de declared in the parent parallel section")

        if self.chunksize:
            self.chunksize = self.chunksize.analyse_expressions(env)

        self.body = self.body.analyse_expressions(env)
        self.analyse_sharing_attributes(env)

        if self.num_threads is not None:
            if self.parent and self.parent.num_threads is not None and not self.parent.is_prange:
                error(self.pos, "num_threads already declared in outer section")
            elif self.parent and not self.parent.is_prange:
                error(self.pos, "num_threads must be declared in the parent parallel section")
            elif (self.num_threads.type.is_int and
                    self.num_threads.is_literal and
                    self.num_threads.compile_time_value(env) <= 0):
                error(self.pos, "argument to num_threads must be greater than 0")

            if not self.num_threads.is_simple() or self.num_threads.type.is_pyobject:
                self.num_threads = self.num_threads.coerce_to(
                    PyrexTypes.c_int_type, env).coerce_to_temp(env)
        return self

    def analyse_sharing_attributes(self, env):
        """
        Analyse the privates for this block and set them in self.privates.
        This should be called in a post-order fashion during the
        analyse_expressions phase
        """
        for entry, (pos, op) in self.assignments.items():

            if self.is_prange and not self.is_parallel:
                # closely nested prange in a with parallel block, disallow
                # assigning to privates in the with parallel block (we
                # consider it too implicit and magicky for users)
                if entry in self.parent.assignments:
                    error(pos, "Cannot assign to private of outer parallel block")
                    continue

            if not self.is_prange and op:
                # Again possible, but considered to magicky
                error(pos, "Reductions not allowed for parallel blocks")
                continue

            # By default all variables should have the same values as if
            # executed sequentially
            self.propagate_var_privatization(entry, pos, op)

    def propagate_var_privatization(self, entry, pos, op):
        """
        Propagate the sharing attributes of a variable. If the privatization is
        determined by a parent scope, done propagate further.

        If we are a prange, we propagate our sharing attributes outwards to
        other pranges. If we are a prange in parallel block and the parallel
        block does not determine the variable private, we propagate to the
        parent of the parent. Recursion stops at parallel blocks, as they have
        no concept of lastprivate or reduction.

        So the following cases propagate:

            sum is a reduction for all loops:

                for i in prange(n):
                    for j in prange(n):
                        for k in prange(n):
                            sum += i * j * k

            sum is a reduction for both loops, local_var is private to the
            parallel with block:

                for i in prange(n):
                    with parallel:
                        local_var = ... # private to the parallel
                        for j in prange(n):
                            sum += i * j

        Nested with parallel blocks are disallowed, because they wouldn't
        allow you to propagate lastprivates or reductions:

            #pragma omp parallel for lastprivate(i)
            for i in prange(n):

                sum = 0

                #pragma omp parallel private(j, sum)
                with parallel:

                    #pragma omp parallel
                    with parallel:

                        #pragma omp for lastprivate(j) reduction(+:sum)
                        for j in prange(n):
                            sum += i

                    # sum and j are well-defined here

                # sum and j are undefined here

            # sum and j are undefined here
        """
        self.privates[entry] = op

        if entry.type.is_memoryviewslice:
            error(pos, "Memoryview slices can only be shared in parallel sections")
            return

        if self.is_prange:
            if not self.is_parallel and entry not in self.parent.assignments:
                # Parent is a parallel with block
                parent = self.parent.parent
            else:
                parent = self.parent

            if parent:
                parent.propagate_var_privatization(entry, pos, op)

    def _allocate_closure_temp(self, code, entry):
        """
        Helper function that allocate a temporary for a closure variable that
        is assigned to.
        """
        if self.parent:
            return self.parent._allocate_closure_temp(code, entry)

        if entry.cname in self.seen_closure_vars:
            return entry.cname

        cname = code.funcstate.allocate_temp(entry.type, True)

        # Add both the actual cname and the temp cname, as the actual cname
        # will be replaced with the temp cname on the entry
        self.seen_closure_vars.add(entry.cname)
        self.seen_closure_vars.add(cname)

        self.modified_entries.append((entry, entry.cname))
        code.putln("%s = %s;" % (cname, entry.cname))
        entry.cname = cname

    def evaluate_before_block(self, code, expr):
        c = self.begin_of_parallel_control_block_point_after_decls
        # we need to set the owner to ourselves temporarily, as
        # allocate_temp may generate a comment in the middle of our pragma
        # otherwise when DebugFlags.debug_temp_code_comments is in effect
        owner = c.funcstate.owner
        c.funcstate.owner = c
        expr.generate_evaluation_code(c)
        c.funcstate.owner = owner

        return expr.result()

    def put_num_threads(self, code):
        """
        Write self.num_threads if set as the num_threads OpenMP directive
        """
        if self.num_threads is not None:
            code.put(" num_threads(%s)" % self.evaluate_before_block(code, self.num_threads))


    def declare_closure_privates(self, code):
        """
        If a variable is in a scope object, we need to allocate a temp and
        assign the value from the temp to the variable in the scope object
        after the parallel section. This kind of copying should be done only
        in the outermost parallel section.
        """
        self.modified_entries = []

        for entry in sorted(self.assignments):
            if entry.from_closure or entry.in_closure:
                self._allocate_closure_temp(code, entry)

    def release_closure_privates(self, code):
        """
        Release any temps used for variables in scope objects. As this is the
        outermost parallel block, we don't need to delete the cnames from
        self.seen_closure_vars.
        """
        for entry, original_cname in self.modified_entries:
            code.putln("%s = %s;" % (original_cname, entry.cname))
            code.funcstate.release_temp(entry.cname)
            entry.cname = original_cname

    def privatize_temps(self, code, exclude_temps=()):
        """
        Make any used temporaries private. Before the relevant code block
        code.start_collecting_temps() should have been called.
        """
        c = self.privatization_insertion_point
        self.privatization_insertion_point = None

        if self.is_parallel:
            self.temps = temps = code.funcstate.stop_collecting_temps()
            privates, firstprivates = [], []
            for temp, type in sorted(temps):
                if type.is_pyobject or type.is_memoryviewslice:
                    firstprivates.append(temp)
                else:
                    privates.append(temp)

            if privates:
                c.put(" private(%s)" % ", ".join(privates))
            if firstprivates:
                c.put(" firstprivate(%s)" % ", ".join(firstprivates))

            if self.breaking_label_used:
                shared_vars = [Naming.parallel_why]
                if self.error_label_used:
                    shared_vars.extend(self.parallel_exc)
                    c.globalstate.use_utility_code(
                        UtilityCode.load_cached(
                            "SharedInFreeThreading",
                            "Synchronization.c"))
                    c.put(f" __Pyx_shared_in_cpython_freethreading({Naming.parallel_freethreading_mutex})")
                    c.put(" private(%s, %s, %s)" % self.pos_info)

                c.put(" shared(%s)" % ', '.join(shared_vars))

    def cleanup_temps(self, code):
        # Now clean up any memoryview slice and object temporaries
        if self.is_parallel and not self.is_nested_prange:
            code.putln("/* Clean up any temporaries */")
            for temp, type in sorted(self.temps):
                code.put_xdecref_clear(temp, type, have_gil=True)

    def setup_parallel_control_flow_block(self, code):
        """
        Sets up a block that surrounds the parallel block to determine
        how the parallel section was exited. Any kind of return is
        trapped (break, continue, return, exceptions). This is the idea:

        {
            int why = 0;

            #pragma omp parallel
            {
                return # -> goto new_return_label;
                goto end_parallel;

            new_return_label:
                why = 3;
                goto end_parallel;

            end_parallel:;
                #pragma omp flush(why) # we need to flush for every iteration
            }

            if (why == 3)
                goto old_return_label;
        }
        """
        self.old_loop_labels = code.new_loop_labels()
        self.old_error_label = code.new_error_label()
        self.old_return_label = code.return_label
        code.return_label = code.new_label(name="return")

        code.begin_block()  # parallel control flow block
        self.begin_of_parallel_control_block_point = code.insertion_point()
        self.begin_of_parallel_control_block_point_after_decls = code.insertion_point()

        self.undef_builtin_expect_apple_gcc_bug(code)

    def begin_parallel_block(self, code):
        """
        Each OpenMP thread in a parallel section that contains a with gil block
        must have the thread-state initialized. The call to
        PyGILState_Release() then deallocates our threadstate. If we wouldn't
        do this, each with gil block would allocate and deallocate one, thereby
        losing exception information before it can be saved before leaving the
        parallel section.
        """
        self.begin_of_parallel_block = code.insertion_point()

    def end_parallel_block(self, code):
        """
        To ensure all OpenMP threads have thread states, we ensure the GIL
        in each thread (which creates a thread state if it doesn't exist),
        after which we release the GIL.
        On exit, reacquire the GIL and release the thread state.

        If compiled without OpenMP support (at the C level), then we still have
        to acquire the GIL to decref any object temporaries.
        """
        begin_code = self.begin_of_parallel_block
        self.begin_of_parallel_block = None

        if self.error_label_used:
            end_code = code

            begin_code.putln("#ifdef _OPENMP")
            begin_code.put_ensure_gil(declare_gilstate=True)
            begin_code.putln("Py_BEGIN_ALLOW_THREADS")
            begin_code.putln("#endif /* _OPENMP */")

            end_code.putln("#ifdef _OPENMP")
            end_code.putln("Py_END_ALLOW_THREADS")
            end_code.putln("#else")
            end_code.put_safe("{\n")
            end_code.put_ensure_gil()
            end_code.putln("#endif /* _OPENMP */")
            self.cleanup_temps(end_code)
            end_code.put_release_ensured_gil()
            end_code.putln("#ifndef _OPENMP")
            end_code.put_safe("}\n")
            end_code.putln("#endif /* _OPENMP */")

    def trap_parallel_exit(self, code, should_flush=False):
        """
        Trap any kind of return inside a parallel construct. 'should_flush'
        indicates whether the variable should be flushed, which is needed by
        prange to skip the loop. It also indicates whether we need to register
        a continue (we need this for parallel blocks, but not for prange
        loops, as it is a direct jump there).

        It uses the same mechanism as try/finally:
            1 continue
            2 break
            3 return
            4 error
        """
        save_lastprivates_label = code.new_label()
        dont_return_label = code.new_label()

        self.any_label_used = False
        self.breaking_label_used = False
        self.error_label_used = False

        self.parallel_private_temps = []

        all_labels = code.get_all_labels()

        # Figure this out before starting to generate any code
        for label in all_labels:
            if code.label_used(label):
                self.breaking_label_used = (self.breaking_label_used or
                                            label != code.continue_label)
                self.any_label_used = True

        if self.any_label_used:
            code.put_goto(dont_return_label)

        for i, label in enumerate(all_labels):
            if not code.label_used(label):
                continue

            is_continue_label = label == code.continue_label

            code.put_label(label)

            if not (should_flush and is_continue_label):
                if label == code.error_label:
                    self.error_label_used = True
                    self.fetch_parallel_exception(code)

                code.putln("%s = %d;" % (Naming.parallel_why, i + 1))
            code.put_goto(dont_return_label)

        if self.any_label_used:
            code.put_label(dont_return_label)

            if should_flush and self.breaking_label_used:
                code.putln_openmp("#pragma omp flush(%s)" % Naming.parallel_why)

    def fetch_parallel_exception(self, code):
        """
        As each OpenMP thread may raise an exception, we need to fetch that
        exception from the threadstate and save it for after the parallel
        section where it can be re-raised in the master thread.

        Although it would seem that __pyx_filename, __pyx_lineno and
        __pyx_clineno are only assigned to under exception conditions (i.e.,
        when we have the GIL), and thus should be allowed to be shared without
        any race condition, they are in fact subject to the same race
        conditions that they were previously when they were global variables
        and functions were allowed to release the GIL:

            thread A                thread B
                acquire
                set lineno
                release
                                        acquire
                                        set lineno
                                        release
                acquire
                fetch exception
                release
                                        skip the fetch

                deallocate threadstate  deallocate threadstate
        """
        code.begin_block()
        code.put_ensure_gil(declare_gilstate=True)
        code.put_acquire_freethreading_lock()

        code.putln_openmp("#pragma omp flush(%s)" % Naming.parallel_exc_type)
        code.putln(
            "if (!%s) {" % Naming.parallel_exc_type)

        code.putln("__Pyx_ErrFetchWithState(&%s, &%s, &%s);" % self.parallel_exc)
        pos_info = chain(*zip(self.parallel_pos_info, self.pos_info))
        code.funcstate.uses_error_indicator = True
        code.putln("%s = %s; %s = %s; %s = %s;" % tuple(pos_info))
        code.put_gotref(Naming.parallel_exc_type, py_object_type)

        code.putln(
            "}")

        code.put_release_freethreading_lock()
        code.put_release_ensured_gil()
        code.end_block()

    def restore_parallel_exception(self, code):
        "Re-raise a parallel exception"
        code.begin_block()
        code.put_ensure_gil(declare_gilstate=True)
        code.put_acquire_freethreading_lock()

        code.put_giveref(Naming.parallel_exc_type, py_object_type)
        code.putln("__Pyx_ErrRestoreWithState(%s, %s, %s);" % self.parallel_exc)
        pos_info = chain(*zip(self.pos_info, self.parallel_pos_info))
        code.putln("%s = %s; %s = %s; %s = %s;" % tuple(pos_info))

        code.put_release_freethreading_lock()
        code.put_release_ensured_gil()
        code.end_block()

    def restore_labels(self, code):
        """
        Restore all old labels. Call this before the 'else' clause to for
        loops and always before ending the parallel control flow block.
        """
        code.set_all_labels(self.old_loop_labels + (self.old_return_label,
                                                    self.old_error_label))

    def end_parallel_control_flow_block(
            self, code, break_=False, continue_=False, return_=False):
        """
        This ends the parallel control flow block and based on how the parallel
        section was exited, takes the corresponding action. The break_ and
        continue_ parameters indicate whether these should be propagated
        outwards:

            for i in prange(...):
                with cython.parallel.parallel():
                    continue

        Here break should be trapped in the parallel block, and propagated to
        the for loop.
        """
        c = self.begin_of_parallel_control_block_point
        self.begin_of_parallel_control_block_point = None
        self.begin_of_parallel_control_block_point_after_decls = None

        if self.num_threads is not None:
            # FIXME: is it the right place? should not normally produce code.
            self.num_threads.generate_disposal_code(code)
            self.num_threads.free_temps(code)

        if c.is_tracing():
            # Disable sys monitoring in parallel blocks. It isn't thread safe in either
            # Cython or Python.
            c.putln("__Pyx_TurnOffSysMonitoringInParallel")

        # Firstly, always prefer errors over returning, continue or break
        if self.error_label_used:
            c.putln("const char *%s = NULL; int %s = 0, %s = 0;" % self.parallel_pos_info)
            c.putln("PyObject *%s = NULL, *%s = NULL, *%s = NULL;" % self.parallel_exc)
            c.putln("#if CYTHON_COMPILING_IN_CPYTHON_FREETHREADING")
            c.putln(f"PyMutex {Naming.parallel_freethreading_mutex} = {{0}};")
            c.putln("#endif")

            code.putln(
                "if (%s) {" % Naming.parallel_exc_type)
            code.putln("/* This may have been overridden by a continue, "
                       "break or return in another thread. Prefer the error. */")
            code.putln("%s = 4;" % Naming.parallel_why)
            code.putln(
                "}")

        if continue_:
            any_label_used = self.any_label_used
        else:
            any_label_used = self.breaking_label_used

        if any_label_used:
            # __pyx_parallel_why is used, declare and initialize
            c.putln("int %s;" % Naming.parallel_why)
            c.putln("%s = 0;" % Naming.parallel_why)

            code.putln(
                "if (%s) {" % Naming.parallel_why)

            for temp_cname, private_cname, temp_type in self.parallel_private_temps:
                if temp_type.is_cpp_class:
                    # utility code was loaded earlier
                    temp_cname = "__PYX_STD_MOVE_IF_SUPPORTED(%s)" % temp_cname
                code.putln("%s = %s;" % (private_cname, temp_cname))

            code.putln("switch (%s) {" % Naming.parallel_why)
            if continue_:
                code.put("    case 1: ")
                code.put_goto(code.continue_label)

            if break_:
                code.put("    case 2: ")
                code.put_goto(code.break_label)

            if return_:
                code.put("    case 3: ")
                code.put_goto(code.return_label)

            if self.error_label_used:
                code.globalstate.use_utility_code(restore_exception_utility_code)
                code.putln("    case 4:")
                self.restore_parallel_exception(code)
                code.put_goto(code.error_label)

            code.putln("}")  # end switch
            code.putln(
                "}")  # end if

        code.end_block()  # end parallel control flow block
        self.redef_builtin_expect_apple_gcc_bug(code)

    # FIXME: improve with version number for OS X Lion
    buggy_platform_macro_condition = "(defined(__APPLE__) || defined(__OSX__))"
    have_expect_condition = "(defined(__GNUC__) && " \
                             "(__GNUC__ > 2 || (__GNUC__ == 2 && (__GNUC_MINOR__ > 95))))"
    redef_condition = "(%s && %s)" % (buggy_platform_macro_condition, have_expect_condition)

    def undef_builtin_expect_apple_gcc_bug(self, code):
        """
        A bug on OS X Lion disallows __builtin_expect macros. This code avoids them
        """
        if not self.parent:
            code.undef_builtin_expect(self.redef_condition)

    def redef_builtin_expect_apple_gcc_bug(self, code):
        if not self.parent:
            code.redef_builtin_expect(self.redef_condition)

    def _parameters_nogil_check(self, env, names, nodes):
        for name, node in zip(names, nodes):
            if node is not None and node.type.is_pyobject:
                error(node.pos, "%s may not be a Python object "
                                "as we don't have the GIL" % name)



class ParallelWithBlockNode(ParallelStatNode):
    """
    This node represents a 'with cython.parallel.parallel():' block
    """

    valid_keyword_arguments = ['num_threads', 'use_threads_if']

    num_threads = None
    threading_condition = None

    def analyse_declarations(self, env):
        super().analyse_declarations(env)
        if self.args:
            error(self.pos, "cython.parallel.parallel() does not take "
                            "positional arguments")

    def generate_execution_code(self, code):

        if self.threading_condition is not None:
            self.threading_condition.generate_evaluation_code(code)

        self.declare_closure_privates(code)
        self.setup_parallel_control_flow_block(code)

        code.putln("#ifdef _OPENMP")
        code.put("#pragma omp parallel ")

        if self.threading_condition is not None:
            code.put("if(%s) " % self.threading_condition.result())


        if self.privates:
            privates = [e.cname for e in self.privates
                        if not e.type.is_pyobject]
            if privates:
                joined_privates = ', '.join(sorted(privates))
                code.put(f'firstprivate({joined_privates})')

        self.privatization_insertion_point = code.insertion_point()
        self.put_num_threads(code)
        code.putln("")

        code.putln("#endif /* _OPENMP */")

        code.begin_block()  # parallel block
        self.begin_parallel_block(code)
        code.funcstate.start_collecting_temps()
        self.body.generate_execution_code(code)
        self.trap_parallel_exit(code)
        self.privatize_temps(code)
        self.end_parallel_block(code)
        code.end_block()  # end parallel block

        continue_ = code.label_used(code.continue_label)
        break_ = code.label_used(code.break_label)
        return_ = code.label_used(code.return_label)

        self.restore_labels(code)

        # ------ cleanup ------
        self.end_parallel_control_flow_block(code, break_=break_,
                                             continue_=continue_,
                                             return_=return_)

        if self.threading_condition is not None:
            self.threading_condition.generate_disposal_code(code)
            self.threading_condition.free_temps(code)

        self.release_closure_privates(code)

    def nogil_check(self, env):
        self._parameters_nogil_check(env, ['use_threads_if'], [self.threading_condition])


class ParallelRangeNode(ParallelStatNode):
    """
    This node represents a 'for i in cython.parallel.prange():' construct.

    target       NameNode       the target iteration variable
    else_clause  Node or None   the else clause of this loop
    """

    child_attrs = ['body', 'target', 'else_clause', 'args', 'num_threads',
                   'chunksize', 'threading_condition']

    body = target = else_clause = args = None

    start = stop = step = None

    is_prange = True

    nogil = None
    schedule = None

    valid_keyword_arguments = ['schedule', 'nogil', 'num_threads', 'chunksize', 'use_threads_if']

    class DummyIteratorNode(Node):
        child_attrs = ["args"]

    def __init__(self, pos, **kwds):
        super().__init__(pos, **kwds)
        # Pretend to be a ForInStatNode for control flow analysis,
        # ensuring that the args get visited when the iterator would be.
        self.iterator = self.DummyIteratorNode(pos, args=self.args)

    def analyse_declarations(self, env):
        super().analyse_declarations(env)
        self.target.analyse_target_declaration(env)
        if self.else_clause is not None:
            self.else_clause.analyse_declarations(env)

        if not self.args or len(self.args) > 3:
            error(self.pos, "Invalid number of positional arguments to prange")
            return

        if len(self.args) == 1:
            self.stop, = self.args
        elif len(self.args) == 2:
            self.start, self.stop = self.args
        else:
            self.start, self.stop, self.step = self.args

        if self.schedule not in (None, 'static', 'dynamic', 'guided', 'runtime'):
            error(self.pos, "Invalid schedule argument to prange: %s" % (self.schedule,))

    def analyse_expressions(self, env):
        was_nogil = env.nogil
        if self.nogil:
            env.nogil = True

        if self.target is None:
            error(self.pos, "prange() can only be used as part of a for loop")
            return self

        self.target = self.target.analyse_target_types(env)

        if not self.target.type.is_numeric:
            # Not a valid type, assume one for now anyway

            if not self.target.type.is_pyobject:
                # nogil_check will catch the is_pyobject case
                error(self.target.pos,
                      "Must be of numeric type, not %s" % self.target.type)

            self.index_type = PyrexTypes.c_py_ssize_t_type
        else:
            self.index_type = self.target.type

        # Setup start, stop and step, allocating temps if needed
        self.names = 'start', 'stop', 'step'
        start_stop_step = self.start, self.stop, self.step

        for node, name in zip(start_stop_step, self.names):
            if node is not None:
                node.analyse_types(env)
                if not node.type.is_numeric:
                    error(node.pos, "%s argument must be numeric" % name)
                    continue

                if not node.is_literal:
                    node = node.coerce_to_temp(env)
                    setattr(self, name, node)

                # As we range from 0 to nsteps, computing the index along the
                # way, we need a fitting type for 'i' and 'nsteps'
                self.index_type = PyrexTypes.widest_numeric_type(
                    self.index_type, node.type)

        if self.else_clause is not None:
            self.else_clause = self.else_clause.analyse_expressions(env)

        # Although not actually an assignment in this scope, it should be
        # treated as such to ensure it is unpacked if a closure temp, and to
        # ensure lastprivate behaviour and propagation. If the target index is
        # not a NameNode, it won't have an entry, and an error was issued by
        # ParallelRangeTransform
        target_entry = getattr(self.target, 'entry', None)
        if target_entry:
            self.assignments[self.target.entry] = self.target.pos, None

        node = super().analyse_expressions(env)

        if node.chunksize:
            if not node.schedule:
                error(node.chunksize.pos,
                      "Must provide schedule with chunksize")
            elif node.schedule == 'runtime':
                error(node.chunksize.pos,
                      "Chunksize not valid for the schedule runtime")
            elif (node.chunksize.type.is_int and
                  node.chunksize.is_literal and
                  node.chunksize.compile_time_value(env) <= 0):
                error(node.chunksize.pos, "Chunksize must not be negative")

            node.chunksize = node.chunksize.coerce_to(
                PyrexTypes.c_int_type, env).coerce_to_temp(env)

        if node.nogil:
            env.nogil = was_nogil

        node.is_nested_prange = node.parent and node.parent.is_prange
        if node.is_nested_prange:
            parent = node
            while parent.parent and parent.parent.is_prange:
                parent = parent.parent

            parent.assignments.update(node.assignments)
            parent.privates.update(node.privates)
            parent.assigned_nodes.extend(node.assigned_nodes)
        return node

    def nogil_check(self, env):
        names = 'start', 'stop', 'step', 'target', 'use_threads_if'
        nodes = self.start, self.stop, self.step, self.target, self.threading_condition
        self._parameters_nogil_check(env, names, nodes)

    def generate_execution_code(self, code):
        """
        Generate code in the following steps

            1)  copy any closure variables determined thread-private
                into temporaries

            2)  allocate temps for start, stop and step

            3)  generate a loop that calculates the total number of steps,
                which then computes the target iteration variable for every step:

                    for i in prange(start, stop, step):
                        ...

                becomes

                    nsteps = (stop - start) / step;
                    i = start;

                    #pragma omp parallel for lastprivate(i)
                    for (temp = 0; temp < nsteps; temp++) {
                        i = start + step * temp;
                        ...
                    }

                Note that accumulation of 'i' would have a data dependency
                between iterations.

                Also, you can't do this

                    for (i = start; i < stop; i += step)
                        ...

                as the '<' operator should become '>' for descending loops.
                'for i from x < i < y:' does not suffer from this problem
                as the relational operator is known at compile time!

            4) release our temps and write back any private closure variables
        """
        self.declare_closure_privates(code)

        # This can only be a NameNode
        target_index_cname = self.target.entry.cname

        # This will be used as the dict to format our code strings, holding
        # the start, stop , step, temps and target cnames
        fmt_dict = {
            'target': target_index_cname,
            'target_type': self.target.type.empty_declaration_code()
        }

        # Setup start, stop and step, allocating temps if needed
        start_stop_step = self.start, self.stop, self.step
        defaults = '0', '0', '1'
        for node, name, default in zip(start_stop_step, self.names, defaults):
            if node is None:
                result = default
            elif node.is_literal:
                result = node.get_constant_c_result_code()
            else:
                node.generate_evaluation_code(code)
                result = node.result()

            fmt_dict[name] = result

        if self.threading_condition is not None:
            self.threading_condition.generate_evaluation_code(code)

        fmt_dict['i'] = code.funcstate.allocate_temp(self.index_type, False)
        fmt_dict['nsteps'] = code.funcstate.allocate_temp(self.index_type, False)

        # TODO: check if the step is 0 and if so, raise an exception in a
        # 'with gil' block. For now, just abort
        if self.step is not None and self.step.has_constant_result() and self.step.constant_result == 0:
            error(node.pos, "Iteration with step 0 is invalid.")
        elif not fmt_dict['step'].isdigit() or int(fmt_dict['step']) == 0:
            code.putln("if (((%(step)s) == 0)) abort();" % fmt_dict)

        self.setup_parallel_control_flow_block(code)  # parallel control flow block

        # Note: nsteps is private in an outer scope if present
        code.globalstate.use_utility_code(UtilityCode.load_cached("IncludeStdlibH", "ModuleSetupCode.c"))
        code.putln("%(nsteps)s = (%(stop)s - %(start)s + %(step)s - %(step)s/abs(%(step)s)) / %(step)s;" % fmt_dict)

        # The target iteration variable might not be initialized, do it only if
        # we are executing at least 1 iteration, otherwise we should leave the
        # target unaffected. The target iteration variable is firstprivate to
        # shut up compiler warnings caused by lastprivate, as the compiler
        # erroneously believes that nsteps may be <= 0, leaving the private
        # target index uninitialized
        code.putln("if (%(nsteps)s > 0)" % fmt_dict)
        code.begin_block()  # if block
        self.generate_loop(code, fmt_dict)
        code.end_block()  # end if block

        self.restore_labels(code)

        if self.else_clause:
            if self.breaking_label_used:
                code.put("if (%s < 2)" % Naming.parallel_why)

            code.begin_block()  # else block
            code.putln("/* else */")
            self.else_clause.generate_execution_code(code)
            code.end_block()  # end else block

        # ------ cleanup ------
        self.end_parallel_control_flow_block(code)  # end parallel control flow block

        # And finally, release our privates and write back any closure
        # variables
        for temp in start_stop_step + (self.chunksize, self.threading_condition):
            if temp is not None:
                temp.generate_disposal_code(code)
                temp.free_temps(code)

        code.funcstate.release_temp(fmt_dict['i'])
        code.funcstate.release_temp(fmt_dict['nsteps'])

        self.release_closure_privates(code)

    def generate_loop(self, code, fmt_dict):
        if self.is_nested_prange:
            code.putln("#if 0")
        else:
            code.putln("#ifdef _OPENMP")

        if not self.is_parallel:
            code.put("#pragma omp for")
            self.privatization_insertion_point = code.insertion_point()
            reduction_codepoint = self.parent.privatization_insertion_point
        else:
            code.put("#pragma omp parallel")

            if self.threading_condition is not None:
                code.put(" if(%s)" % self.threading_condition.result())

            self.privatization_insertion_point = code.insertion_point()
            reduction_codepoint = self.privatization_insertion_point
            code.putln("")
            code.putln("#endif /* _OPENMP */")

            code.begin_block()  # pragma omp parallel begin block

            # Initialize the GIL if needed for this thread
            self.begin_parallel_block(code)

            if self.is_nested_prange:
                code.putln("#if 0")
            else:
                code.putln("#ifdef _OPENMP")
            code.put("#pragma omp for")

        for entry, op in sorted(self.privates.items()):
            # Don't declare the index variable as a reduction
            if op and op in "+*-&^|" and entry != self.target.entry:
                if entry.type.is_pyobject:
                    error(self.pos, "Python objects cannot be reductions")
                else:
                    #code.put(" reduction(%s:%s)" % (op, entry.cname))
                    # This is the only way reductions + nesting works in gcc4.5
                    reduction_codepoint.put(
                                " reduction(%s:%s)" % (op, entry.cname))
            else:
                if not entry.type.is_pyobject:
                    code.put(" firstprivate(%s)" % entry.cname)
                    code.put(" lastprivate(%s)" % entry.cname)

        if self.schedule:
            if self.chunksize:
                chunksize = ", %s" % self.evaluate_before_block(code, self.chunksize)
            else:
                chunksize = ""

            code.put(" schedule(%s%s)" % (self.schedule, chunksize))

        self.put_num_threads(reduction_codepoint)

        code.putln("")
        code.putln("#endif /* _OPENMP */")

        code.put("for (%(i)s = 0; %(i)s < %(nsteps)s; %(i)s++)" % fmt_dict)
        code.begin_block()  # for loop block

        guard_around_body_codepoint = code.insertion_point()

        # Start if guard block around the body. This may be unnecessary, but
        # at least it doesn't spoil indentation
        code.begin_block()

        code.putln("%(target)s = (%(target_type)s)(%(start)s + %(step)s * %(i)s);" % fmt_dict)

        if self.is_parallel and not self.is_nested_prange:
            # nested pranges are not omp'ified, temps go to outer loops
            code.funcstate.start_collecting_temps()

        self.body.generate_execution_code(code)
        self.trap_parallel_exit(code, should_flush=True)
        if self.is_parallel and not self.is_nested_prange:
            # nested pranges are not omp'ified, temps go to outer loops
            self.privatize_temps(code)

        if self.breaking_label_used:
            # Put a guard around the loop body in case return, break or
            # exceptions might be used
            guard_around_body_codepoint.putln("if (%s < 2)" % Naming.parallel_why)

        code.end_block()  # end guard around loop body
        code.end_block()  # end for loop block

        if self.is_parallel:
            # Release the GIL and deallocate the thread state
            self.end_parallel_block(code)
            code.end_block()  # pragma omp parallel end block


class CnameDecoratorNode(StatNode):
    """
    This node is for the cname decorator in CythonUtilityCode:

        @cname('the_cname')
        cdef func(...):
            ...

    In case of a cdef class the cname specifies the objstruct_cname.

    node        the node to which the cname decorator is applied
    cname       the cname the node should get
    """

    child_attrs = ['node']

    def analyse_declarations(self, env):
        self.node.analyse_declarations(env)

        node = self.node
        if isinstance(node, CompilerDirectivesNode):
            node = node.body.stats[0]

        self.is_function = isinstance(node, (FuncDefNode, CVarDefNode))
        is_struct_or_enum = isinstance(node, (CStructOrUnionDefNode, CEnumDefNode))
        e = node.entry

        if self.is_function:
            e.cname = self.cname
            e.func_cname = self.cname
            e.used = True
            if e.pyfunc_cname and '.' in e.pyfunc_cname:
                e.pyfunc_cname = self.mangle(e.pyfunc_cname)
        elif is_struct_or_enum:
            e.cname = e.type.cname = self.cname
        else:
            scope = node.scope

            e.cname = self.cname
            e.type.objstruct_cname = self.cname + '_obj'
            e.type.typeobj_cname = Naming.typeobj_prefix + self.cname
            e.type.typeptr_cname = self.cname + '_type'
            e.type.scope.namespace_cname = e.type.typeptr_cname

            e.as_variable.cname = e.type.typeptr_cname

            scope.scope_prefix = self.cname + "_"

            for name, entry in scope.entries.items():
                if entry.func_cname:
                    entry.func_cname = self.mangle(entry.cname)
                if entry.pyfunc_cname:
                    entry.pyfunc_cname = self.mangle(entry.pyfunc_cname)

    def mangle(self, cname):
        if '.' in cname:
            # remove __pyx_base from func_cname
            cname = cname.split('.')[-1]
        return '%s_%s' % (self.cname, cname)

    def analyse_expressions(self, env):
        self.node = self.node.analyse_expressions(env)
        return self

    def generate_function_definitions(self, env, code):
        "Ensure a prototype for every @cname method in the right place"
        if self.is_function and env.is_c_class_scope:
            # method in cdef class, generate a prototype in the header
            h_code = code.globalstate['utility_code_proto']

            if isinstance(self.node, DefNode):
                self.node.generate_function_header(
                    h_code, with_pymethdef=False, proto_only=True)
            else:
                from . import ModuleNode
                entry = self.node.entry
                cname = entry.cname
                entry.cname = entry.func_cname

                ModuleNode.generate_cfunction_declaration(
                    entry,
                    env.global_scope(),
                    h_code,
                    definition=True)

                entry.cname = cname

        self.node.generate_function_definitions(env, code)

    def generate_execution_code(self, code):
        self.node.generate_execution_code(code)


class ErrorNode(Node):
    """
    Node type for things that we want to get through the parser
    (especially for things that are being scanned in "tentative_scan"
    blocks), but should immediately raise and error afterwards.

    what    str
    """
    child_attrs = []


#------------------------------------------------------------------------------------
#
#  Runtime support code
#
#------------------------------------------------------------------------------------

if Options.gcc_branch_hints:
    branch_prediction_macros = """
/* Test for GCC > 2.95 */
#if defined(__GNUC__) \
    && (__GNUC__ > 2 || (__GNUC__ == 2 && (__GNUC_MINOR__ > 95)))
  #define likely(x)   __builtin_expect(!!(x), 1)
  #define unlikely(x) __builtin_expect(!!(x), 0)
#else /* !__GNUC__ or GCC < 2.95 */
  #define likely(x)   (x)
  #define unlikely(x) (x)
#endif /* __GNUC__ */
"""
else:
    branch_prediction_macros = """
#define likely(x)   (x)
#define unlikely(x) (x)
"""

#------------------------------------------------------------------------------------

printing_utility_code = UtilityCode.load_cached("Print", "Printing.c")
printing_one_utility_code = UtilityCode.load_cached("PrintOne", "Printing.c")

#------------------------------------------------------------------------------------

# Exception raising code
#
# Exceptions are raised by __Pyx_Raise() and stored as plain
# type/value/tb in PyThreadState->curexc_*.  When being caught by an
# 'except' statement, curexc_* is moved over to exc_* by
# __Pyx_GetException()

restore_exception_utility_code = UtilityCode.load_cached("PyErrFetchRestore", "Exceptions.c")
raise_utility_code = UtilityCode.load_cached("RaiseException", "Exceptions.c")
get_exception_utility_code = UtilityCode.load_cached("GetException", "Exceptions.c")
swap_exception_utility_code = UtilityCode.load_cached("SwapException", "Exceptions.c")
reset_exception_utility_code = UtilityCode.load_cached("SaveResetException", "Exceptions.c")
traceback_utility_code = UtilityCode.load_cached("AddTraceback", "Exceptions.c")
