Update prebuilt Clang to r416183b from Android.
https://android.googlesource.com/platform/prebuilts/clang/host/
linux-x86/+/06a71ddac05c22edb2d10b590e1769b3f8619bef
clang 12.0.5 (based on r416183b) from build 7284624.
Change-Id: I277a316abcf47307562d8b748b84870f31a72866
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/linux-x64/clang/python3/lib/python3.9/dataclasses.py b/linux-x64/clang/python3/lib/python3.9/dataclasses.py
new file mode 100644
index 0000000..530d3e9
--- /dev/null
+++ b/linux-x64/clang/python3/lib/python3.9/dataclasses.py
@@ -0,0 +1,1284 @@
+import re
+import sys
+import copy
+import types
+import inspect
+import keyword
+import builtins
+import functools
+import _thread
+from types import GenericAlias
+
+
+__all__ = ['dataclass',
+ 'field',
+ 'Field',
+ 'FrozenInstanceError',
+ 'InitVar',
+ 'MISSING',
+
+ # Helper functions.
+ 'fields',
+ 'asdict',
+ 'astuple',
+ 'make_dataclass',
+ 'replace',
+ 'is_dataclass',
+ ]
+
+# Conditions for adding methods. The boxes indicate what action the
+# dataclass decorator takes. For all of these tables, when I talk
+# about init=, repr=, eq=, order=, unsafe_hash=, or frozen=, I'm
+# referring to the arguments to the @dataclass decorator. When
+# checking if a dunder method already exists, I mean check for an
+# entry in the class's __dict__. I never check to see if an attribute
+# is defined in a base class.
+
+# Key:
+# +=========+=========================================+
+# + Value | Meaning |
+# +=========+=========================================+
+# | <blank> | No action: no method is added. |
+# +---------+-----------------------------------------+
+# | add | Generated method is added. |
+# +---------+-----------------------------------------+
+# | raise | TypeError is raised. |
+# +---------+-----------------------------------------+
+# | None | Attribute is set to None. |
+# +=========+=========================================+
+
+# __init__
+#
+# +--- init= parameter
+# |
+# v | | |
+# | no | yes | <--- class has __init__ in __dict__?
+# +=======+=======+=======+
+# | False | | |
+# +-------+-------+-------+
+# | True | add | | <- the default
+# +=======+=======+=======+
+
+# __repr__
+#
+# +--- repr= parameter
+# |
+# v | | |
+# | no | yes | <--- class has __repr__ in __dict__?
+# +=======+=======+=======+
+# | False | | |
+# +-------+-------+-------+
+# | True | add | | <- the default
+# +=======+=======+=======+
+
+
+# __setattr__
+# __delattr__
+#
+# +--- frozen= parameter
+# |
+# v | | |
+# | no | yes | <--- class has __setattr__ or __delattr__ in __dict__?
+# +=======+=======+=======+
+# | False | | | <- the default
+# +-------+-------+-------+
+# | True | add | raise |
+# +=======+=======+=======+
+# Raise because not adding these methods would break the "frozen-ness"
+# of the class.
+
+# __eq__
+#
+# +--- eq= parameter
+# |
+# v | | |
+# | no | yes | <--- class has __eq__ in __dict__?
+# +=======+=======+=======+
+# | False | | |
+# +-------+-------+-------+
+# | True | add | | <- the default
+# +=======+=======+=======+
+
+# __lt__
+# __le__
+# __gt__
+# __ge__
+#
+# +--- order= parameter
+# |
+# v | | |
+# | no | yes | <--- class has any comparison method in __dict__?
+# +=======+=======+=======+
+# | False | | | <- the default
+# +-------+-------+-------+
+# | True | add | raise |
+# +=======+=======+=======+
+# Raise because to allow this case would interfere with using
+# functools.total_ordering.
+
+# __hash__
+
+# +------------------- unsafe_hash= parameter
+# | +----------- eq= parameter
+# | | +--- frozen= parameter
+# | | |
+# v v v | | |
+# | no | yes | <--- class has explicitly defined __hash__
+# +=======+=======+=======+========+========+
+# | False | False | False | | | No __eq__, use the base class __hash__
+# +-------+-------+-------+--------+--------+
+# | False | False | True | | | No __eq__, use the base class __hash__
+# +-------+-------+-------+--------+--------+
+# | False | True | False | None | | <-- the default, not hashable
+# +-------+-------+-------+--------+--------+
+# | False | True | True | add | | Frozen, so hashable, allows override
+# +-------+-------+-------+--------+--------+
+# | True | False | False | add | raise | Has no __eq__, but hashable
+# +-------+-------+-------+--------+--------+
+# | True | False | True | add | raise | Has no __eq__, but hashable
+# +-------+-------+-------+--------+--------+
+# | True | True | False | add | raise | Not frozen, but hashable
+# +-------+-------+-------+--------+--------+
+# | True | True | True | add | raise | Frozen, so hashable
+# +=======+=======+=======+========+========+
+# For boxes that are blank, __hash__ is untouched and therefore
+# inherited from the base class. If the base is object, then
+# id-based hashing is used.
+#
+# Note that a class may already have __hash__=None if it specified an
+# __eq__ method in the class body (not one that was created by
+# @dataclass).
+#
+# See _hash_action (below) for a coded version of this table.
+
+
+# Raised when an attempt is made to modify a frozen class.
+class FrozenInstanceError(AttributeError): pass
+
+# A sentinel object for default values to signal that a default
+# factory will be used. This is given a nice repr() which will appear
+# in the function signature of dataclasses' constructors.
+class _HAS_DEFAULT_FACTORY_CLASS:
+ def __repr__(self):
+ return '<factory>'
+_HAS_DEFAULT_FACTORY = _HAS_DEFAULT_FACTORY_CLASS()
+
+# A sentinel object to detect if a parameter is supplied or not. Use
+# a class to give it a better repr.
+class _MISSING_TYPE:
+ pass
+MISSING = _MISSING_TYPE()
+
+# Since most per-field metadata will be unused, create an empty
+# read-only proxy that can be shared among all fields.
+_EMPTY_METADATA = types.MappingProxyType({})
+
+# Markers for the various kinds of fields and pseudo-fields.
+class _FIELD_BASE:
+ def __init__(self, name):
+ self.name = name
+ def __repr__(self):
+ return self.name
+_FIELD = _FIELD_BASE('_FIELD')
+_FIELD_CLASSVAR = _FIELD_BASE('_FIELD_CLASSVAR')
+_FIELD_INITVAR = _FIELD_BASE('_FIELD_INITVAR')
+
+# The name of an attribute on the class where we store the Field
+# objects. Also used to check if a class is a Data Class.
+_FIELDS = '__dataclass_fields__'
+
+# The name of an attribute on the class that stores the parameters to
+# @dataclass.
+_PARAMS = '__dataclass_params__'
+
+# The name of the function, that if it exists, is called at the end of
+# __init__.
+_POST_INIT_NAME = '__post_init__'
+
+# String regex that string annotations for ClassVar or InitVar must match.
+# Allows "identifier.identifier[" or "identifier[".
+# https://bugs.python.org/issue33453 for details.
+_MODULE_IDENTIFIER_RE = re.compile(r'^(?:\s*(\w+)\s*\.)?\s*(\w+)')
+
+class InitVar:
+ __slots__ = ('type', )
+
+ def __init__(self, type):
+ self.type = type
+
+ def __repr__(self):
+ if isinstance(self.type, type):
+ type_name = self.type.__name__
+ else:
+ # typing objects, e.g. List[int]
+ type_name = repr(self.type)
+ return f'dataclasses.InitVar[{type_name}]'
+
+ def __class_getitem__(cls, type):
+ return InitVar(type)
+
+
+# Instances of Field are only ever created from within this module,
+# and only from the field() function, although Field instances are
+# exposed externally as (conceptually) read-only objects.
+#
+# name and type are filled in after the fact, not in __init__.
+# They're not known at the time this class is instantiated, but it's
+# convenient if they're available later.
+#
+# When cls._FIELDS is filled in with a list of Field objects, the name
+# and type fields will have been populated.
+class Field:
+ __slots__ = ('name',
+ 'type',
+ 'default',
+ 'default_factory',
+ 'repr',
+ 'hash',
+ 'init',
+ 'compare',
+ 'metadata',
+ '_field_type', # Private: not to be used by user code.
+ )
+
+ def __init__(self, default, default_factory, init, repr, hash, compare,
+ metadata):
+ self.name = None
+ self.type = None
+ self.default = default
+ self.default_factory = default_factory
+ self.init = init
+ self.repr = repr
+ self.hash = hash
+ self.compare = compare
+ self.metadata = (_EMPTY_METADATA
+ if metadata is None else
+ types.MappingProxyType(metadata))
+ self._field_type = None
+
+ def __repr__(self):
+ return ('Field('
+ f'name={self.name!r},'
+ f'type={self.type!r},'
+ f'default={self.default!r},'
+ f'default_factory={self.default_factory!r},'
+ f'init={self.init!r},'
+ f'repr={self.repr!r},'
+ f'hash={self.hash!r},'
+ f'compare={self.compare!r},'
+ f'metadata={self.metadata!r},'
+ f'_field_type={self._field_type}'
+ ')')
+
+ # This is used to support the PEP 487 __set_name__ protocol in the
+ # case where we're using a field that contains a descriptor as a
+ # default value. For details on __set_name__, see
+ # https://www.python.org/dev/peps/pep-0487/#implementation-details.
+ #
+ # Note that in _process_class, this Field object is overwritten
+ # with the default value, so the end result is a descriptor that
+ # had __set_name__ called on it at the right time.
+ def __set_name__(self, owner, name):
+ func = getattr(type(self.default), '__set_name__', None)
+ if func:
+ # There is a __set_name__ method on the descriptor, call
+ # it.
+ func(self.default, owner, name)
+
+ __class_getitem__ = classmethod(GenericAlias)
+
+
+class _DataclassParams:
+ __slots__ = ('init',
+ 'repr',
+ 'eq',
+ 'order',
+ 'unsafe_hash',
+ 'frozen',
+ )
+
+ def __init__(self, init, repr, eq, order, unsafe_hash, frozen):
+ self.init = init
+ self.repr = repr
+ self.eq = eq
+ self.order = order
+ self.unsafe_hash = unsafe_hash
+ self.frozen = frozen
+
+ def __repr__(self):
+ return ('_DataclassParams('
+ f'init={self.init!r},'
+ f'repr={self.repr!r},'
+ f'eq={self.eq!r},'
+ f'order={self.order!r},'
+ f'unsafe_hash={self.unsafe_hash!r},'
+ f'frozen={self.frozen!r}'
+ ')')
+
+
+# This function is used instead of exposing Field creation directly,
+# so that a type checker can be told (via overloads) that this is a
+# function whose type depends on its parameters.
+def field(*, default=MISSING, default_factory=MISSING, init=True, repr=True,
+ hash=None, compare=True, metadata=None):
+ """Return an object to identify dataclass fields.
+
+ default is the default value of the field. default_factory is a
+ 0-argument function called to initialize a field's value. If init
+ is True, the field will be a parameter to the class's __init__()
+ function. If repr is True, the field will be included in the
+ object's repr(). If hash is True, the field will be included in
+ the object's hash(). If compare is True, the field will be used
+ in comparison functions. metadata, if specified, must be a
+ mapping which is stored but not otherwise examined by dataclass.
+
+ It is an error to specify both default and default_factory.
+ """
+
+ if default is not MISSING and default_factory is not MISSING:
+ raise ValueError('cannot specify both default and default_factory')
+ return Field(default, default_factory, init, repr, hash, compare,
+ metadata)
+
+
+def _tuple_str(obj_name, fields):
+ # Return a string representing each field of obj_name as a tuple
+ # member. So, if fields is ['x', 'y'] and obj_name is "self",
+ # return "(self.x,self.y)".
+
+ # Special case for the 0-tuple.
+ if not fields:
+ return '()'
+ # Note the trailing comma, needed if this turns out to be a 1-tuple.
+ return f'({",".join([f"{obj_name}.{f.name}" for f in fields])},)'
+
+
+# This function's logic is copied from "recursive_repr" function in
+# reprlib module to avoid dependency.
+def _recursive_repr(user_function):
+ # Decorator to make a repr function return "..." for a recursive
+ # call.
+ repr_running = set()
+
+ @functools.wraps(user_function)
+ def wrapper(self):
+ key = id(self), _thread.get_ident()
+ if key in repr_running:
+ return '...'
+ repr_running.add(key)
+ try:
+ result = user_function(self)
+ finally:
+ repr_running.discard(key)
+ return result
+ return wrapper
+
+
+def _create_fn(name, args, body, *, globals=None, locals=None,
+ return_type=MISSING):
+ # Note that we mutate locals when exec() is called. Caller
+ # beware! The only callers are internal to this module, so no
+ # worries about external callers.
+ if locals is None:
+ locals = {}
+ if 'BUILTINS' not in locals:
+ locals['BUILTINS'] = builtins
+ return_annotation = ''
+ if return_type is not MISSING:
+ locals['_return_type'] = return_type
+ return_annotation = '->_return_type'
+ args = ','.join(args)
+ body = '\n'.join(f' {b}' for b in body)
+
+ # Compute the text of the entire function.
+ txt = f' def {name}({args}){return_annotation}:\n{body}'
+
+ local_vars = ', '.join(locals.keys())
+ txt = f"def __create_fn__({local_vars}):\n{txt}\n return {name}"
+
+ ns = {}
+ exec(txt, globals, ns)
+ return ns['__create_fn__'](**locals)
+
+
+def _field_assign(frozen, name, value, self_name):
+ # If we're a frozen class, then assign to our fields in __init__
+ # via object.__setattr__. Otherwise, just use a simple
+ # assignment.
+ #
+ # self_name is what "self" is called in this function: don't
+ # hard-code "self", since that might be a field name.
+ if frozen:
+ return f'BUILTINS.object.__setattr__({self_name},{name!r},{value})'
+ return f'{self_name}.{name}={value}'
+
+
+def _field_init(f, frozen, globals, self_name):
+ # Return the text of the line in the body of __init__ that will
+ # initialize this field.
+
+ default_name = f'_dflt_{f.name}'
+ if f.default_factory is not MISSING:
+ if f.init:
+ # This field has a default factory. If a parameter is
+ # given, use it. If not, call the factory.
+ globals[default_name] = f.default_factory
+ value = (f'{default_name}() '
+ f'if {f.name} is _HAS_DEFAULT_FACTORY '
+ f'else {f.name}')
+ else:
+ # This is a field that's not in the __init__ params, but
+ # has a default factory function. It needs to be
+ # initialized here by calling the factory function,
+ # because there's no other way to initialize it.
+
+ # For a field initialized with a default=defaultvalue, the
+ # class dict just has the default value
+ # (cls.fieldname=defaultvalue). But that won't work for a
+ # default factory, the factory must be called in __init__
+ # and we must assign that to self.fieldname. We can't
+ # fall back to the class dict's value, both because it's
+ # not set, and because it might be different per-class
+ # (which, after all, is why we have a factory function!).
+
+ globals[default_name] = f.default_factory
+ value = f'{default_name}()'
+ else:
+ # No default factory.
+ if f.init:
+ if f.default is MISSING:
+ # There's no default, just do an assignment.
+ value = f.name
+ elif f.default is not MISSING:
+ globals[default_name] = f.default
+ value = f.name
+ else:
+ # This field does not need initialization. Signify that
+ # to the caller by returning None.
+ return None
+
+ # Only test this now, so that we can create variables for the
+ # default. However, return None to signify that we're not going
+ # to actually do the assignment statement for InitVars.
+ if f._field_type is _FIELD_INITVAR:
+ return None
+
+ # Now, actually generate the field assignment.
+ return _field_assign(frozen, f.name, value, self_name)
+
+
+def _init_param(f):
+ # Return the __init__ parameter string for this field. For
+ # example, the equivalent of 'x:int=3' (except instead of 'int',
+ # reference a variable set to int, and instead of '3', reference a
+ # variable set to 3).
+ if f.default is MISSING and f.default_factory is MISSING:
+ # There's no default, and no default_factory, just output the
+ # variable name and type.
+ default = ''
+ elif f.default is not MISSING:
+ # There's a default, this will be the name that's used to look
+ # it up.
+ default = f'=_dflt_{f.name}'
+ elif f.default_factory is not MISSING:
+ # There's a factory function. Set a marker.
+ default = '=_HAS_DEFAULT_FACTORY'
+ return f'{f.name}:_type_{f.name}{default}'
+
+
+def _init_fn(fields, frozen, has_post_init, self_name, globals):
+ # fields contains both real fields and InitVar pseudo-fields.
+
+ # Make sure we don't have fields without defaults following fields
+ # with defaults. This actually would be caught when exec-ing the
+ # function source code, but catching it here gives a better error
+ # message, and future-proofs us in case we build up the function
+ # using ast.
+ seen_default = False
+ for f in fields:
+ # Only consider fields in the __init__ call.
+ if f.init:
+ if not (f.default is MISSING and f.default_factory is MISSING):
+ seen_default = True
+ elif seen_default:
+ raise TypeError(f'non-default argument {f.name!r} '
+ 'follows default argument')
+
+ locals = {f'_type_{f.name}': f.type for f in fields}
+ locals.update({
+ 'MISSING': MISSING,
+ '_HAS_DEFAULT_FACTORY': _HAS_DEFAULT_FACTORY,
+ })
+
+ body_lines = []
+ for f in fields:
+ line = _field_init(f, frozen, locals, self_name)
+ # line is None means that this field doesn't require
+ # initialization (it's a pseudo-field). Just skip it.
+ if line:
+ body_lines.append(line)
+
+ # Does this class have a post-init function?
+ if has_post_init:
+ params_str = ','.join(f.name for f in fields
+ if f._field_type is _FIELD_INITVAR)
+ body_lines.append(f'{self_name}.{_POST_INIT_NAME}({params_str})')
+
+ # If no body lines, use 'pass'.
+ if not body_lines:
+ body_lines = ['pass']
+
+ return _create_fn('__init__',
+ [self_name] + [_init_param(f) for f in fields if f.init],
+ body_lines,
+ locals=locals,
+ globals=globals,
+ return_type=None)
+
+
+def _repr_fn(fields, globals):
+ fn = _create_fn('__repr__',
+ ('self',),
+ ['return self.__class__.__qualname__ + f"(' +
+ ', '.join([f"{f.name}={{self.{f.name}!r}}"
+ for f in fields]) +
+ ')"'],
+ globals=globals)
+ return _recursive_repr(fn)
+
+
+def _frozen_get_del_attr(cls, fields, globals):
+ locals = {'cls': cls,
+ 'FrozenInstanceError': FrozenInstanceError}
+ if fields:
+ fields_str = '(' + ','.join(repr(f.name) for f in fields) + ',)'
+ else:
+ # Special case for the zero-length tuple.
+ fields_str = '()'
+ return (_create_fn('__setattr__',
+ ('self', 'name', 'value'),
+ (f'if type(self) is cls or name in {fields_str}:',
+ ' raise FrozenInstanceError(f"cannot assign to field {name!r}")',
+ f'super(cls, self).__setattr__(name, value)'),
+ locals=locals,
+ globals=globals),
+ _create_fn('__delattr__',
+ ('self', 'name'),
+ (f'if type(self) is cls or name in {fields_str}:',
+ ' raise FrozenInstanceError(f"cannot delete field {name!r}")',
+ f'super(cls, self).__delattr__(name)'),
+ locals=locals,
+ globals=globals),
+ )
+
+
+def _cmp_fn(name, op, self_tuple, other_tuple, globals):
+ # Create a comparison function. If the fields in the object are
+ # named 'x' and 'y', then self_tuple is the string
+ # '(self.x,self.y)' and other_tuple is the string
+ # '(other.x,other.y)'.
+
+ return _create_fn(name,
+ ('self', 'other'),
+ [ 'if other.__class__ is self.__class__:',
+ f' return {self_tuple}{op}{other_tuple}',
+ 'return NotImplemented'],
+ globals=globals)
+
+
+def _hash_fn(fields, globals):
+ self_tuple = _tuple_str('self', fields)
+ return _create_fn('__hash__',
+ ('self',),
+ [f'return hash({self_tuple})'],
+ globals=globals)
+
+
+def _is_classvar(a_type, typing):
+ # This test uses a typing internal class, but it's the best way to
+ # test if this is a ClassVar.
+ return (a_type is typing.ClassVar
+ or (type(a_type) is typing._GenericAlias
+ and a_type.__origin__ is typing.ClassVar))
+
+
+def _is_initvar(a_type, dataclasses):
+ # The module we're checking against is the module we're
+ # currently in (dataclasses.py).
+ return (a_type is dataclasses.InitVar
+ or type(a_type) is dataclasses.InitVar)
+
+
+def _is_type(annotation, cls, a_module, a_type, is_type_predicate):
+ # Given a type annotation string, does it refer to a_type in
+ # a_module? For example, when checking that annotation denotes a
+ # ClassVar, then a_module is typing, and a_type is
+ # typing.ClassVar.
+
+ # It's possible to look up a_module given a_type, but it involves
+ # looking in sys.modules (again!), and seems like a waste since
+ # the caller already knows a_module.
+
+ # - annotation is a string type annotation
+ # - cls is the class that this annotation was found in
+ # - a_module is the module we want to match
+ # - a_type is the type in that module we want to match
+ # - is_type_predicate is a function called with (obj, a_module)
+ # that determines if obj is of the desired type.
+
+ # Since this test does not do a local namespace lookup (and
+ # instead only a module (global) lookup), there are some things it
+ # gets wrong.
+
+ # With string annotations, cv0 will be detected as a ClassVar:
+ # CV = ClassVar
+ # @dataclass
+ # class C0:
+ # cv0: CV
+
+ # But in this example cv1 will not be detected as a ClassVar:
+ # @dataclass
+ # class C1:
+ # CV = ClassVar
+ # cv1: CV
+
+ # In C1, the code in this function (_is_type) will look up "CV" in
+ # the module and not find it, so it will not consider cv1 as a
+ # ClassVar. This is a fairly obscure corner case, and the best
+ # way to fix it would be to eval() the string "CV" with the
+ # correct global and local namespaces. However that would involve
+ # a eval() penalty for every single field of every dataclass
+ # that's defined. It was judged not worth it.
+
+ match = _MODULE_IDENTIFIER_RE.match(annotation)
+ if match:
+ ns = None
+ module_name = match.group(1)
+ if not module_name:
+ # No module name, assume the class's module did
+ # "from dataclasses import InitVar".
+ ns = sys.modules.get(cls.__module__).__dict__
+ else:
+ # Look up module_name in the class's module.
+ module = sys.modules.get(cls.__module__)
+ if module and module.__dict__.get(module_name) is a_module:
+ ns = sys.modules.get(a_type.__module__).__dict__
+ if ns and is_type_predicate(ns.get(match.group(2)), a_module):
+ return True
+ return False
+
+
+def _get_field(cls, a_name, a_type):
+ # Return a Field object for this field name and type. ClassVars
+ # and InitVars are also returned, but marked as such (see
+ # f._field_type).
+
+ # If the default value isn't derived from Field, then it's only a
+ # normal default value. Convert it to a Field().
+ default = getattr(cls, a_name, MISSING)
+ if isinstance(default, Field):
+ f = default
+ else:
+ if isinstance(default, types.MemberDescriptorType):
+ # This is a field in __slots__, so it has no default value.
+ default = MISSING
+ f = field(default=default)
+
+ # Only at this point do we know the name and the type. Set them.
+ f.name = a_name
+ f.type = a_type
+
+ # Assume it's a normal field until proven otherwise. We're next
+ # going to decide if it's a ClassVar or InitVar, everything else
+ # is just a normal field.
+ f._field_type = _FIELD
+
+ # In addition to checking for actual types here, also check for
+ # string annotations. get_type_hints() won't always work for us
+ # (see https://github.com/python/typing/issues/508 for example),
+ # plus it's expensive and would require an eval for every stirng
+ # annotation. So, make a best effort to see if this is a ClassVar
+ # or InitVar using regex's and checking that the thing referenced
+ # is actually of the correct type.
+
+ # For the complete discussion, see https://bugs.python.org/issue33453
+
+ # If typing has not been imported, then it's impossible for any
+ # annotation to be a ClassVar. So, only look for ClassVar if
+ # typing has been imported by any module (not necessarily cls's
+ # module).
+ typing = sys.modules.get('typing')
+ if typing:
+ if (_is_classvar(a_type, typing)
+ or (isinstance(f.type, str)
+ and _is_type(f.type, cls, typing, typing.ClassVar,
+ _is_classvar))):
+ f._field_type = _FIELD_CLASSVAR
+
+ # If the type is InitVar, or if it's a matching string annotation,
+ # then it's an InitVar.
+ if f._field_type is _FIELD:
+ # The module we're checking against is the module we're
+ # currently in (dataclasses.py).
+ dataclasses = sys.modules[__name__]
+ if (_is_initvar(a_type, dataclasses)
+ or (isinstance(f.type, str)
+ and _is_type(f.type, cls, dataclasses, dataclasses.InitVar,
+ _is_initvar))):
+ f._field_type = _FIELD_INITVAR
+
+ # Validations for individual fields. This is delayed until now,
+ # instead of in the Field() constructor, since only here do we
+ # know the field name, which allows for better error reporting.
+
+ # Special restrictions for ClassVar and InitVar.
+ if f._field_type in (_FIELD_CLASSVAR, _FIELD_INITVAR):
+ if f.default_factory is not MISSING:
+ raise TypeError(f'field {f.name} cannot have a '
+ 'default factory')
+ # Should I check for other field settings? default_factory
+ # seems the most serious to check for. Maybe add others. For
+ # example, how about init=False (or really,
+ # init=<not-the-default-init-value>)? It makes no sense for
+ # ClassVar and InitVar to specify init=<anything>.
+
+ # For real fields, disallow mutable defaults for known types.
+ if f._field_type is _FIELD and isinstance(f.default, (list, dict, set)):
+ raise ValueError(f'mutable default {type(f.default)} for field '
+ f'{f.name} is not allowed: use default_factory')
+
+ return f
+
+
+def _set_new_attribute(cls, name, value):
+ # Never overwrites an existing attribute. Returns True if the
+ # attribute already exists.
+ if name in cls.__dict__:
+ return True
+ setattr(cls, name, value)
+ return False
+
+
+# Decide if/how we're going to create a hash function. Key is
+# (unsafe_hash, eq, frozen, does-hash-exist). Value is the action to
+# take. The common case is to do nothing, so instead of providing a
+# function that is a no-op, use None to signify that.
+
+def _hash_set_none(cls, fields, globals):
+ return None
+
+def _hash_add(cls, fields, globals):
+ flds = [f for f in fields if (f.compare if f.hash is None else f.hash)]
+ return _hash_fn(flds, globals)
+
+def _hash_exception(cls, fields, globals):
+ # Raise an exception.
+ raise TypeError(f'Cannot overwrite attribute __hash__ '
+ f'in class {cls.__name__}')
+
+#
+# +-------------------------------------- unsafe_hash?
+# | +------------------------------- eq?
+# | | +------------------------ frozen?
+# | | | +---------------- has-explicit-hash?
+# | | | |
+# | | | | +------- action
+# | | | | |
+# v v v v v
+_hash_action = {(False, False, False, False): None,
+ (False, False, False, True ): None,
+ (False, False, True, False): None,
+ (False, False, True, True ): None,
+ (False, True, False, False): _hash_set_none,
+ (False, True, False, True ): None,
+ (False, True, True, False): _hash_add,
+ (False, True, True, True ): None,
+ (True, False, False, False): _hash_add,
+ (True, False, False, True ): _hash_exception,
+ (True, False, True, False): _hash_add,
+ (True, False, True, True ): _hash_exception,
+ (True, True, False, False): _hash_add,
+ (True, True, False, True ): _hash_exception,
+ (True, True, True, False): _hash_add,
+ (True, True, True, True ): _hash_exception,
+ }
+# See https://bugs.python.org/issue32929#msg312829 for an if-statement
+# version of this table.
+
+
+def _process_class(cls, init, repr, eq, order, unsafe_hash, frozen):
+ # Now that dicts retain insertion order, there's no reason to use
+ # an ordered dict. I am leveraging that ordering here, because
+ # derived class fields overwrite base class fields, but the order
+ # is defined by the base class, which is found first.
+ fields = {}
+
+ if cls.__module__ in sys.modules:
+ globals = sys.modules[cls.__module__].__dict__
+ else:
+ # Theoretically this can happen if someone writes
+ # a custom string to cls.__module__. In which case
+ # such dataclass won't be fully introspectable
+ # (w.r.t. typing.get_type_hints) but will still function
+ # correctly.
+ globals = {}
+
+ setattr(cls, _PARAMS, _DataclassParams(init, repr, eq, order,
+ unsafe_hash, frozen))
+
+ # Find our base classes in reverse MRO order, and exclude
+ # ourselves. In reversed order so that more derived classes
+ # override earlier field definitions in base classes. As long as
+ # we're iterating over them, see if any are frozen.
+ any_frozen_base = False
+ has_dataclass_bases = False
+ for b in cls.__mro__[-1:0:-1]:
+ # Only process classes that have been processed by our
+ # decorator. That is, they have a _FIELDS attribute.
+ base_fields = getattr(b, _FIELDS, None)
+ if base_fields:
+ has_dataclass_bases = True
+ for f in base_fields.values():
+ fields[f.name] = f
+ if getattr(b, _PARAMS).frozen:
+ any_frozen_base = True
+
+ # Annotations that are defined in this class (not in base
+ # classes). If __annotations__ isn't present, then this class
+ # adds no new annotations. We use this to compute fields that are
+ # added by this class.
+ #
+ # Fields are found from cls_annotations, which is guaranteed to be
+ # ordered. Default values are from class attributes, if a field
+ # has a default. If the default value is a Field(), then it
+ # contains additional info beyond (and possibly including) the
+ # actual default value. Pseudo-fields ClassVars and InitVars are
+ # included, despite the fact that they're not real fields. That's
+ # dealt with later.
+ cls_annotations = cls.__dict__.get('__annotations__', {})
+
+ # Now find fields in our class. While doing so, validate some
+ # things, and set the default values (as class attributes) where
+ # we can.
+ cls_fields = [_get_field(cls, name, type)
+ for name, type in cls_annotations.items()]
+ for f in cls_fields:
+ fields[f.name] = f
+
+ # If the class attribute (which is the default value for this
+ # field) exists and is of type 'Field', replace it with the
+ # real default. This is so that normal class introspection
+ # sees a real default value, not a Field.
+ if isinstance(getattr(cls, f.name, None), Field):
+ if f.default is MISSING:
+ # If there's no default, delete the class attribute.
+ # This happens if we specify field(repr=False), for
+ # example (that is, we specified a field object, but
+ # no default value). Also if we're using a default
+ # factory. The class attribute should not be set at
+ # all in the post-processed class.
+ delattr(cls, f.name)
+ else:
+ setattr(cls, f.name, f.default)
+
+ # Do we have any Field members that don't also have annotations?
+ for name, value in cls.__dict__.items():
+ if isinstance(value, Field) and not name in cls_annotations:
+ raise TypeError(f'{name!r} is a field but has no type annotation')
+
+ # Check rules that apply if we are derived from any dataclasses.
+ if has_dataclass_bases:
+ # Raise an exception if any of our bases are frozen, but we're not.
+ if any_frozen_base and not frozen:
+ raise TypeError('cannot inherit non-frozen dataclass from a '
+ 'frozen one')
+
+ # Raise an exception if we're frozen, but none of our bases are.
+ if not any_frozen_base and frozen:
+ raise TypeError('cannot inherit frozen dataclass from a '
+ 'non-frozen one')
+
+ # Remember all of the fields on our class (including bases). This
+ # also marks this class as being a dataclass.
+ setattr(cls, _FIELDS, fields)
+
+ # Was this class defined with an explicit __hash__? Note that if
+ # __eq__ is defined in this class, then python will automatically
+ # set __hash__ to None. This is a heuristic, as it's possible
+ # that such a __hash__ == None was not auto-generated, but it
+ # close enough.
+ class_hash = cls.__dict__.get('__hash__', MISSING)
+ has_explicit_hash = not (class_hash is MISSING or
+ (class_hash is None and '__eq__' in cls.__dict__))
+
+ # If we're generating ordering methods, we must be generating the
+ # eq methods.
+ if order and not eq:
+ raise ValueError('eq must be true if order is true')
+
+ if init:
+ # Does this class have a post-init function?
+ has_post_init = hasattr(cls, _POST_INIT_NAME)
+
+ # Include InitVars and regular fields (so, not ClassVars).
+ flds = [f for f in fields.values()
+ if f._field_type in (_FIELD, _FIELD_INITVAR)]
+ _set_new_attribute(cls, '__init__',
+ _init_fn(flds,
+ frozen,
+ has_post_init,
+ # The name to use for the "self"
+ # param in __init__. Use "self"
+ # if possible.
+ '__dataclass_self__' if 'self' in fields
+ else 'self',
+ globals,
+ ))
+
+ # Get the fields as a list, and include only real fields. This is
+ # used in all of the following methods.
+ field_list = [f for f in fields.values() if f._field_type is _FIELD]
+
+ if repr:
+ flds = [f for f in field_list if f.repr]
+ _set_new_attribute(cls, '__repr__', _repr_fn(flds, globals))
+
+ if eq:
+ # Create _eq__ method. There's no need for a __ne__ method,
+ # since python will call __eq__ and negate it.
+ flds = [f for f in field_list if f.compare]
+ self_tuple = _tuple_str('self', flds)
+ other_tuple = _tuple_str('other', flds)
+ _set_new_attribute(cls, '__eq__',
+ _cmp_fn('__eq__', '==',
+ self_tuple, other_tuple,
+ globals=globals))
+
+ if order:
+ # Create and set the ordering methods.
+ flds = [f for f in field_list if f.compare]
+ self_tuple = _tuple_str('self', flds)
+ other_tuple = _tuple_str('other', flds)
+ for name, op in [('__lt__', '<'),
+ ('__le__', '<='),
+ ('__gt__', '>'),
+ ('__ge__', '>='),
+ ]:
+ if _set_new_attribute(cls, name,
+ _cmp_fn(name, op, self_tuple, other_tuple,
+ globals=globals)):
+ raise TypeError(f'Cannot overwrite attribute {name} '
+ f'in class {cls.__name__}. Consider using '
+ 'functools.total_ordering')
+
+ if frozen:
+ for fn in _frozen_get_del_attr(cls, field_list, globals):
+ if _set_new_attribute(cls, fn.__name__, fn):
+ raise TypeError(f'Cannot overwrite attribute {fn.__name__} '
+ f'in class {cls.__name__}')
+
+ # Decide if/how we're going to create a hash function.
+ hash_action = _hash_action[bool(unsafe_hash),
+ bool(eq),
+ bool(frozen),
+ has_explicit_hash]
+ if hash_action:
+ # No need to call _set_new_attribute here, since by the time
+ # we're here the overwriting is unconditional.
+ cls.__hash__ = hash_action(cls, field_list, globals)
+
+ if not getattr(cls, '__doc__'):
+ # Create a class doc-string.
+ cls.__doc__ = (cls.__name__ +
+ str(inspect.signature(cls)).replace(' -> None', ''))
+
+ return cls
+
+
+def dataclass(cls=None, /, *, init=True, repr=True, eq=True, order=False,
+ unsafe_hash=False, frozen=False):
+ """Returns the same class as was passed in, with dunder methods
+ added based on the fields defined in the class.
+
+ Examines PEP 526 __annotations__ to determine fields.
+
+ If init is true, an __init__() method is added to the class. If
+ repr is true, a __repr__() method is added. If order is true, rich
+ comparison dunder methods are added. If unsafe_hash is true, a
+ __hash__() method function is added. If frozen is true, fields may
+ not be assigned to after instance creation.
+ """
+
+ def wrap(cls):
+ return _process_class(cls, init, repr, eq, order, unsafe_hash, frozen)
+
+ # See if we're being called as @dataclass or @dataclass().
+ if cls is None:
+ # We're called with parens.
+ return wrap
+
+ # We're called as @dataclass without parens.
+ return wrap(cls)
+
+
+def fields(class_or_instance):
+ """Return a tuple describing the fields of this dataclass.
+
+ Accepts a dataclass or an instance of one. Tuple elements are of
+ type Field.
+ """
+
+ # Might it be worth caching this, per class?
+ try:
+ fields = getattr(class_or_instance, _FIELDS)
+ except AttributeError:
+ raise TypeError('must be called with a dataclass type or instance')
+
+ # Exclude pseudo-fields. Note that fields is sorted by insertion
+ # order, so the order of the tuple is as the fields were defined.
+ return tuple(f for f in fields.values() if f._field_type is _FIELD)
+
+
+def _is_dataclass_instance(obj):
+ """Returns True if obj is an instance of a dataclass."""
+ return hasattr(type(obj), _FIELDS)
+
+
+def is_dataclass(obj):
+ """Returns True if obj is a dataclass or an instance of a
+ dataclass."""
+ cls = obj if isinstance(obj, type) else type(obj)
+ return hasattr(cls, _FIELDS)
+
+
+def asdict(obj, *, dict_factory=dict):
+ """Return the fields of a dataclass instance as a new dictionary mapping
+ field names to field values.
+
+ Example usage:
+
+ @dataclass
+ class C:
+ x: int
+ y: int
+
+ c = C(1, 2)
+ assert asdict(c) == {'x': 1, 'y': 2}
+
+ If given, 'dict_factory' will be used instead of built-in dict.
+ The function applies recursively to field values that are
+ dataclass instances. This will also look into built-in containers:
+ tuples, lists, and dicts.
+ """
+ if not _is_dataclass_instance(obj):
+ raise TypeError("asdict() should be called on dataclass instances")
+ return _asdict_inner(obj, dict_factory)
+
+
+def _asdict_inner(obj, dict_factory):
+ if _is_dataclass_instance(obj):
+ result = []
+ for f in fields(obj):
+ value = _asdict_inner(getattr(obj, f.name), dict_factory)
+ result.append((f.name, value))
+ return dict_factory(result)
+ elif isinstance(obj, tuple) and hasattr(obj, '_fields'):
+ # obj is a namedtuple. Recurse into it, but the returned
+ # object is another namedtuple of the same type. This is
+ # similar to how other list- or tuple-derived classes are
+ # treated (see below), but we just need to create them
+ # differently because a namedtuple's __init__ needs to be
+ # called differently (see bpo-34363).
+
+ # I'm not using namedtuple's _asdict()
+ # method, because:
+ # - it does not recurse in to the namedtuple fields and
+ # convert them to dicts (using dict_factory).
+ # - I don't actually want to return a dict here. The main
+ # use case here is json.dumps, and it handles converting
+ # namedtuples to lists. Admittedly we're losing some
+ # information here when we produce a json list instead of a
+ # dict. Note that if we returned dicts here instead of
+ # namedtuples, we could no longer call asdict() on a data
+ # structure where a namedtuple was used as a dict key.
+
+ return type(obj)(*[_asdict_inner(v, dict_factory) for v in obj])
+ elif isinstance(obj, (list, tuple)):
+ # Assume we can create an object of this type by passing in a
+ # generator (which is not true for namedtuples, handled
+ # above).
+ return type(obj)(_asdict_inner(v, dict_factory) for v in obj)
+ elif isinstance(obj, dict):
+ return type(obj)((_asdict_inner(k, dict_factory),
+ _asdict_inner(v, dict_factory))
+ for k, v in obj.items())
+ else:
+ return copy.deepcopy(obj)
+
+
+def astuple(obj, *, tuple_factory=tuple):
+ """Return the fields of a dataclass instance as a new tuple of field values.
+
+ Example usage::
+
+ @dataclass
+ class C:
+ x: int
+ y: int
+
+ c = C(1, 2)
+ assert astuple(c) == (1, 2)
+
+ If given, 'tuple_factory' will be used instead of built-in tuple.
+ The function applies recursively to field values that are
+ dataclass instances. This will also look into built-in containers:
+ tuples, lists, and dicts.
+ """
+
+ if not _is_dataclass_instance(obj):
+ raise TypeError("astuple() should be called on dataclass instances")
+ return _astuple_inner(obj, tuple_factory)
+
+
+def _astuple_inner(obj, tuple_factory):
+ if _is_dataclass_instance(obj):
+ result = []
+ for f in fields(obj):
+ value = _astuple_inner(getattr(obj, f.name), tuple_factory)
+ result.append(value)
+ return tuple_factory(result)
+ elif isinstance(obj, tuple) and hasattr(obj, '_fields'):
+ # obj is a namedtuple. Recurse into it, but the returned
+ # object is another namedtuple of the same type. This is
+ # similar to how other list- or tuple-derived classes are
+ # treated (see below), but we just need to create them
+ # differently because a namedtuple's __init__ needs to be
+ # called differently (see bpo-34363).
+ return type(obj)(*[_astuple_inner(v, tuple_factory) for v in obj])
+ elif isinstance(obj, (list, tuple)):
+ # Assume we can create an object of this type by passing in a
+ # generator (which is not true for namedtuples, handled
+ # above).
+ return type(obj)(_astuple_inner(v, tuple_factory) for v in obj)
+ elif isinstance(obj, dict):
+ return type(obj)((_astuple_inner(k, tuple_factory), _astuple_inner(v, tuple_factory))
+ for k, v in obj.items())
+ else:
+ return copy.deepcopy(obj)
+
+
+def make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True,
+ repr=True, eq=True, order=False, unsafe_hash=False,
+ frozen=False):
+ """Return a new dynamically created dataclass.
+
+ The dataclass name will be 'cls_name'. 'fields' is an iterable
+ of either (name), (name, type) or (name, type, Field) objects. If type is
+ omitted, use the string 'typing.Any'. Field objects are created by
+ the equivalent of calling 'field(name, type [, Field-info])'.
+
+ C = make_dataclass('C', ['x', ('y', int), ('z', int, field(init=False))], bases=(Base,))
+
+ is equivalent to:
+
+ @dataclass
+ class C(Base):
+ x: 'typing.Any'
+ y: int
+ z: int = field(init=False)
+
+ For the bases and namespace parameters, see the builtin type() function.
+
+ The parameters init, repr, eq, order, unsafe_hash, and frozen are passed to
+ dataclass().
+ """
+
+ if namespace is None:
+ namespace = {}
+ else:
+ # Copy namespace since we're going to mutate it.
+ namespace = namespace.copy()
+
+ # While we're looking through the field names, validate that they
+ # are identifiers, are not keywords, and not duplicates.
+ seen = set()
+ anns = {}
+ for item in fields:
+ if isinstance(item, str):
+ name = item
+ tp = 'typing.Any'
+ elif len(item) == 2:
+ name, tp, = item
+ elif len(item) == 3:
+ name, tp, spec = item
+ namespace[name] = spec
+ else:
+ raise TypeError(f'Invalid field: {item!r}')
+
+ if not isinstance(name, str) or not name.isidentifier():
+ raise TypeError(f'Field names must be valid identifiers: {name!r}')
+ if keyword.iskeyword(name):
+ raise TypeError(f'Field names must not be keywords: {name!r}')
+ if name in seen:
+ raise TypeError(f'Field name duplicated: {name!r}')
+
+ seen.add(name)
+ anns[name] = tp
+
+ namespace['__annotations__'] = anns
+ # We use `types.new_class()` instead of simply `type()` to allow dynamic creation
+ # of generic dataclassses.
+ cls = types.new_class(cls_name, bases, {}, lambda ns: ns.update(namespace))
+ return dataclass(cls, init=init, repr=repr, eq=eq, order=order,
+ unsafe_hash=unsafe_hash, frozen=frozen)
+
+
+def replace(obj, /, **changes):
+ """Return a new object replacing specified fields with new values.
+
+ This is especially useful for frozen classes. Example usage:
+
+ @dataclass(frozen=True)
+ class C:
+ x: int
+ y: int
+
+ c = C(1, 2)
+ c1 = replace(c, x=3)
+ assert c1.x == 3 and c1.y == 2
+ """
+
+ # We're going to mutate 'changes', but that's okay because it's a
+ # new dict, even if called with 'replace(obj, **my_changes)'.
+
+ if not _is_dataclass_instance(obj):
+ raise TypeError("replace() should be called on dataclass instances")
+
+ # It's an error to have init=False fields in 'changes'.
+ # If a field is not in 'changes', read its value from the provided obj.
+
+ for f in getattr(obj, _FIELDS).values():
+ # Only consider normal fields or InitVars.
+ if f._field_type is _FIELD_CLASSVAR:
+ continue
+
+ if not f.init:
+ # Error if this field is specified in changes.
+ if f.name in changes:
+ raise ValueError(f'field {f.name} is declared with '
+ 'init=False, it cannot be specified with '
+ 'replace()')
+ continue
+
+ if f.name not in changes:
+ if f._field_type is _FIELD_INITVAR:
+ raise ValueError(f"InitVar {f.name!r} "
+ 'must be specified with replace()')
+ changes[f.name] = getattr(obj, f.name)
+
+ # Create the new object, which calls __init__() and
+ # __post_init__() (if defined), using all of the init fields we've
+ # added and/or left in 'changes'. If there are values supplied in
+ # changes that aren't fields, this will correctly raise a
+ # TypeError.
+ return obj.__class__(**changes)