"""Abstract syntax tree node classes (i.e. parse tree).""" import os from enum import Enum, unique from abc import abstractmethod from mypy.backports import OrderedDict from collections import defaultdict from typing import ( Any, TypeVar, List, Tuple, cast, Set, Dict, Union, Optional, Callable, Sequence, Iterator ) from typing_extensions import DefaultDict, Final, TYPE_CHECKING, TypeAlias as _TypeAlias from mypy_extensions import trait import mypy.strconv from mypy.util import short_type from mypy.visitor import NodeVisitor, StatementVisitor, ExpressionVisitor from mypy.bogus_type import Bogus if TYPE_CHECKING: from mypy.patterns import Pattern class Context: """Base type for objects that are valid as error message locations.""" __slots__ = ('line', 'column', 'end_line', 'end_column') def __init__(self, line: int = -1, column: int = -1) -> None: self.line = line self.column = column self.end_line: Optional[int] = None self.end_column: Optional[int] = None def set_line(self, target: Union['Context', int], column: Optional[int] = None, end_line: Optional[int] = None, end_column: Optional[int] = None) -> None: """If target is a node, pull line (and column) information into this node. If column is specified, this will override any column information coming from a node. """ if isinstance(target, int): self.line = target else: self.line = target.line self.column = target.column self.end_line = target.end_line self.end_column = target.end_column if column is not None: self.column = column if end_line is not None: self.end_line = end_line if end_column is not None: self.end_column = end_column def get_line(self) -> int: """Don't use. Use x.line.""" return self.line def get_column(self) -> int: """Don't use. Use x.column.""" return self.column if TYPE_CHECKING: # break import cycle only needed for mypy import mypy.types T = TypeVar('T') JsonDict: _TypeAlias = Dict[str, Any] # Symbol table node kinds # # TODO rename to use more descriptive names LDEF: Final = 0 GDEF: Final = 1 MDEF: Final = 2 # Placeholder for a name imported via 'from ... import'. Second phase of # semantic will replace this the actual imported reference. This is # needed so that we can detect whether a name has been imported during # XXX what? UNBOUND_IMPORTED: Final = 3 # RevealExpr node kinds REVEAL_TYPE: Final = 0 REVEAL_LOCALS: Final = 1 LITERAL_YES: Final = 2 LITERAL_TYPE: Final = 1 LITERAL_NO: Final = 0 node_kinds: Final = { LDEF: 'Ldef', GDEF: 'Gdef', MDEF: 'Mdef', UNBOUND_IMPORTED: 'UnboundImported', } inverse_node_kinds: Final = {_kind: _name for _name, _kind in node_kinds.items()} implicit_module_attrs: Final = { '__name__': '__builtins__.str', '__doc__': None, # depends on Python version, see semanal.py '__path__': None, # depends on if the module is a package '__file__': '__builtins__.str', '__package__': '__builtins__.str', '__annotations__': None, # dict[str, Any] bounded in add_implicit_module_attrs() } # These aliases exist because built-in class objects are not subscriptable. # For example `list[int]` fails at runtime. Instead List[int] should be used. type_aliases: Final = { 'typing.List': 'builtins.list', 'typing.Dict': 'builtins.dict', 'typing.Set': 'builtins.set', 'typing.FrozenSet': 'builtins.frozenset', 'typing.ChainMap': 'collections.ChainMap', 'typing.Counter': 'collections.Counter', 'typing.DefaultDict': 'collections.defaultdict', 'typing.Deque': 'collections.deque', 'typing.OrderedDict': 'collections.OrderedDict', # HACK: a lie in lieu of actual support for PEP 675 'typing.LiteralString': 'builtins.str', } # This keeps track of the oldest supported Python version where the corresponding # alias source is available. type_aliases_source_versions: Final = { 'typing.List': (2, 7), 'typing.Dict': (2, 7), 'typing.Set': (2, 7), 'typing.FrozenSet': (2, 7), 'typing.ChainMap': (3, 3), 'typing.Counter': (2, 7), 'typing.DefaultDict': (2, 7), 'typing.Deque': (2, 7), 'typing.OrderedDict': (3, 7), 'typing.LiteralString': (3, 11), } # This keeps track of aliases in `typing_extensions`, which we treat specially. typing_extensions_aliases: Final = { # See: https://github.com/python/mypy/issues/11528 'typing_extensions.OrderedDict': 'collections.OrderedDict', # HACK: a lie in lieu of actual support for PEP 675 'typing_extensions.LiteralString': 'builtins.str', } reverse_builtin_aliases: Final = { 'builtins.list': 'typing.List', 'builtins.dict': 'typing.Dict', 'builtins.set': 'typing.Set', 'builtins.frozenset': 'typing.FrozenSet', } _nongen_builtins: Final = {"builtins.tuple": "typing.Tuple", "builtins.enumerate": ""} _nongen_builtins.update((name, alias) for alias, name in type_aliases.items()) # Drop OrderedDict from this for backward compatibility del _nongen_builtins['collections.OrderedDict'] # HACK: consequence of hackily treating LiteralString as an alias for str del _nongen_builtins['builtins.str'] def get_nongen_builtins(python_version: Tuple[int, int]) -> Dict[str, str]: # After 3.9 with pep585 generic builtins are allowed. return _nongen_builtins if python_version < (3, 9) else {} RUNTIME_PROTOCOL_DECOS: Final = ( "typing.runtime_checkable", "typing_extensions.runtime", "typing_extensions.runtime_checkable", ) class Node(Context): """Common base class for all non-type parse tree nodes.""" __slots__ = () def __str__(self) -> str: ans = self.accept(mypy.strconv.StrConv()) if ans is None: return repr(self) return ans def accept(self, visitor: NodeVisitor[T]) -> T: raise RuntimeError('Not implemented') @trait class Statement(Node): """A statement node.""" __slots__ = () def accept(self, visitor: StatementVisitor[T]) -> T: raise RuntimeError('Not implemented') @trait class Expression(Node): """An expression node.""" __slots__ = () def accept(self, visitor: ExpressionVisitor[T]) -> T: raise RuntimeError('Not implemented') class FakeExpression(Expression): """A dummy expression. We need a dummy expression in one place, and can't instantiate Expression because it is a trait and mypyc barfs. """ __slots__ = () # TODO: # Lvalue = Union['NameExpr', 'MemberExpr', 'IndexExpr', 'SuperExpr', 'StarExpr' # 'TupleExpr']; see #1783. Lvalue: _TypeAlias = Expression @trait class SymbolNode(Node): """Nodes that can be stored in a symbol table.""" __slots__ = () @property @abstractmethod def name(self) -> str: pass # fullname can often be None even though the type system # disagrees. We mark this with Bogus to let mypyc know not to # worry about it. @property @abstractmethod def fullname(self) -> Bogus[str]: pass @abstractmethod def serialize(self) -> JsonDict: pass @classmethod def deserialize(cls, data: JsonDict) -> 'SymbolNode': classname = data['.class'] method = deserialize_map.get(classname) if method is not None: return method(data) raise NotImplementedError(f'unexpected .class {classname}') # Items: fullname, related symbol table node, surrounding type (if any) Definition: _TypeAlias = Tuple[str, 'SymbolTableNode', Optional['TypeInfo']] class MypyFile(SymbolNode): """The abstract syntax tree of a single source file.""" __slots__ = ('_fullname', 'path', 'defs', 'alias_deps', 'is_bom', 'names', 'imports', 'ignored_lines', 'is_stub', 'is_cache_skeleton', 'is_partial_stub_package', 'plugin_deps', 'future_import_flags') # Fully qualified module name _fullname: Bogus[str] # Path to the file (empty string if not known) path: str # Top-level definitions and statements defs: List[Statement] # Type alias dependencies as mapping from target to set of alias full names alias_deps: DefaultDict[str, Set[str]] # Is there a UTF-8 BOM at the start? is_bom: bool names: "SymbolTable" # All import nodes within the file (also ones within functions etc.) imports: List["ImportBase"] # Lines on which to ignore certain errors when checking. # If the value is empty, ignore all errors; otherwise, the list contains all # error codes to ignore. ignored_lines: Dict[int, List[str]] # Is this file represented by a stub file (.pyi)? is_stub: bool # Is this loaded from the cache and thus missing the actual body of the file? is_cache_skeleton: bool # Does this represent an __init__.pyi stub with a module __getattr__ # (i.e. a partial stub package), for such packages we suppress any missing # module errors in addition to missing attribute errors. is_partial_stub_package: bool # Plugin-created dependencies plugin_deps: Dict[str, Set[str]] # Future imports defined in this file. Populated during semantic analysis. future_import_flags: Set[str] def __init__(self, defs: List[Statement], imports: List['ImportBase'], is_bom: bool = False, ignored_lines: Optional[Dict[int, List[str]]] = None) -> None: super().__init__() self.defs = defs self.line = 1 # Dummy line number self.imports = imports self.is_bom = is_bom self.alias_deps = defaultdict(set) self.plugin_deps = {} if ignored_lines: self.ignored_lines = ignored_lines else: self.ignored_lines = {} self.path = '' self.is_stub = False self.is_cache_skeleton = False self.is_partial_stub_package = False self.future_import_flags = set() def local_definitions(self) -> Iterator[Definition]: """Return all definitions within the module (including nested). This doesn't include imported definitions. """ return local_definitions(self.names, self.fullname) @property def name(self) -> str: return '' if not self._fullname else self._fullname.split('.')[-1] @property def fullname(self) -> Bogus[str]: return self._fullname def accept(self, visitor: NodeVisitor[T]) -> T: return visitor.visit_mypy_file(self) def is_package_init_file(self) -> bool: return len(self.path) != 0 and os.path.basename(self.path).startswith('__init__.') def is_future_flag_set(self, flag: str) -> bool: return flag in self.future_import_flags def serialize(self) -> JsonDict: return {'.class': 'MypyFile', '_fullname': self._fullname, 'names': self.names.serialize(self._fullname), 'is_stub': self.is_stub, 'path': self.path, 'is_partial_stub_package': self.is_partial_stub_package, 'future_import_flags': list(self.future_import_flags), } @classmethod def deserialize(cls, data: JsonDict) -> 'MypyFile': assert data['.class'] == 'MypyFile', data tree = MypyFile([], []) tree._fullname = data['_fullname'] tree.names = SymbolTable.deserialize(data['names']) tree.is_stub = data['is_stub'] tree.path = data['path'] tree.is_partial_stub_package = data['is_partial_stub_package'] tree.is_cache_skeleton = True tree.future_import_flags = set(data['future_import_flags']) return tree class ImportBase(Statement): """Base class for all import statements.""" __slots__ = ('is_unreachable', 'is_top_level', 'is_mypy_only', 'assignments') is_unreachable: bool # Set by semanal.SemanticAnalyzerPass1 if inside `if False` etc. is_top_level: bool # Ditto if outside any class or def is_mypy_only: bool # Ditto if inside `if TYPE_CHECKING` or `if MYPY` # If an import replaces existing definitions, we construct dummy assignment # statements that assign the imported names to the names in the current scope, # for type checking purposes. Example: # # x = 1 # from m import x <-- add assignment representing "x = m.x" assignments: List["AssignmentStmt"] def __init__(self) -> None: super().__init__() self.assignments = [] self.is_unreachable = False self.is_top_level = False self.is_mypy_only = False class Import(ImportBase): """import m [as n]""" __slots__ = ('ids',) ids: List[Tuple[str, Optional[str]]] # (module id, as id) def __init__(self, ids: List[Tuple[str, Optional[str]]]) -> None: super().__init__() self.ids = ids def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_import(self) class ImportFrom(ImportBase): """from m import x [as y], ...""" __slots__ = ('id', 'names', 'relative') id: str relative: int names: List[Tuple[str, Optional[str]]] # Tuples (name, as name) def __init__(self, id: str, relative: int, names: List[Tuple[str, Optional[str]]]) -> None: super().__init__() self.id = id self.names = names self.relative = relative def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_import_from(self) class ImportAll(ImportBase): """from m import *""" __slots__ = ('id', 'relative', 'imported_names') id: str relative: int # NOTE: Only filled and used by old semantic analyzer. imported_names: List[str] def __init__(self, id: str, relative: int) -> None: super().__init__() self.id = id self.relative = relative self.imported_names = [] def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_import_all(self) class ImportedName(SymbolNode): """Indirect reference to a fullname stored in symbol table. This node is not present in the original program as such. This is just a temporary artifact in binding imported names. After semantic analysis pass 2, these references should be replaced with direct reference to a real AST node. Note that this is neither a Statement nor an Expression so this can't be visited. """ __slots__ = ('target_fullname',) def __init__(self, target_fullname: str) -> None: super().__init__() self.target_fullname = target_fullname @property def name(self) -> str: return self.target_fullname.split('.')[-1] @property def fullname(self) -> str: return self.target_fullname def serialize(self) -> JsonDict: assert False, "ImportedName leaked from semantic analysis" @classmethod def deserialize(cls, data: JsonDict) -> 'ImportedName': assert False, "ImportedName should never be serialized" def __str__(self) -> str: return f'ImportedName({self.target_fullname})' FUNCBASE_FLAGS: Final = ["is_property", "is_class", "is_static", "is_final"] class FuncBase(Node): """Abstract base class for function-like nodes. N.B: Although this has SymbolNode subclasses (FuncDef, OverloadedFuncDef), avoid calling isinstance(..., FuncBase) on something that is typed as SymbolNode. This is to work around mypy bug #3603, in which mypy doesn't understand multiple inheritance very well, and will assume that a SymbolNode cannot be a FuncBase. Instead, test against SYMBOL_FUNCBASE_TYPES, which enumerates SymbolNode subclasses that are also FuncBase subclasses. """ __slots__ = ('type', 'unanalyzed_type', 'info', 'is_property', 'is_class', # Uses "@classmethod" (explicit or implicit) 'is_static', # Uses "@staticmethod" 'is_final', # Uses "@final" '_fullname', ) def __init__(self) -> None: super().__init__() # Type signature. This is usually CallableType or Overloaded, but it can be # something else for decorated functions. self.type: Optional[mypy.types.ProperType] = None # Original, not semantically analyzed type (used for reprocessing) self.unanalyzed_type: Optional[mypy.types.ProperType] = None # If method, reference to TypeInfo # TODO: Type should be Optional[TypeInfo] self.info = FUNC_NO_INFO self.is_property = False self.is_class = False self.is_static = False self.is_final = False # Name with module prefix # TODO: Type should be Optional[str] self._fullname = cast(Bogus[str], None) @property @abstractmethod def name(self) -> str: pass @property def fullname(self) -> Bogus[str]: return self._fullname OverloadPart: _TypeAlias = Union['FuncDef', 'Decorator'] class OverloadedFuncDef(FuncBase, SymbolNode, Statement): """A logical node representing all the variants of a multi-declaration function. A multi-declaration function is often an @overload, but can also be a @property with a setter and a/or a deleter. This node has no explicit representation in the source program. Overloaded variants must be consecutive in the source file. """ __slots__ = ('items', 'unanalyzed_items', 'impl') items: List[OverloadPart] unanalyzed_items: List[OverloadPart] impl: Optional[OverloadPart] def __init__(self, items: List['OverloadPart']) -> None: super().__init__() self.items = items self.unanalyzed_items = items.copy() self.impl = None if len(items) > 0: self.set_line(items[0].line, items[0].column) self.is_final = False @property def name(self) -> str: if self.items: return self.items[0].name else: # This may happen for malformed overload assert self.impl is not None return self.impl.name def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_overloaded_func_def(self) def serialize(self) -> JsonDict: return {'.class': 'OverloadedFuncDef', 'items': [i.serialize() for i in self.items], 'type': None if self.type is None else self.type.serialize(), 'fullname': self._fullname, 'impl': None if self.impl is None else self.impl.serialize(), 'flags': get_flags(self, FUNCBASE_FLAGS), } @classmethod def deserialize(cls, data: JsonDict) -> 'OverloadedFuncDef': assert data['.class'] == 'OverloadedFuncDef' res = OverloadedFuncDef([ cast(OverloadPart, SymbolNode.deserialize(d)) for d in data['items']]) if data.get('impl') is not None: res.impl = cast(OverloadPart, SymbolNode.deserialize(data['impl'])) # set line for empty overload items, as not set in __init__ if len(res.items) > 0: res.set_line(res.impl.line) if data.get('type') is not None: typ = mypy.types.deserialize_type(data['type']) assert isinstance(typ, mypy.types.ProperType) res.type = typ res._fullname = data['fullname'] set_flags(res, data['flags']) # NOTE: res.info will be set in the fixup phase. return res class Argument(Node): """A single argument in a FuncItem.""" __slots__ = ('variable', 'type_annotation', 'initializer', 'kind', 'pos_only') def __init__(self, variable: 'Var', type_annotation: 'Optional[mypy.types.Type]', initializer: Optional[Expression], kind: 'ArgKind', pos_only: bool = False) -> None: super().__init__() self.variable = variable self.type_annotation = type_annotation self.initializer = initializer self.kind = kind # must be an ARG_* constant self.pos_only = pos_only def set_line(self, target: Union[Context, int], column: Optional[int] = None, end_line: Optional[int] = None, end_column: Optional[int] = None) -> None: super().set_line(target, column, end_line, end_column) if self.initializer and self.initializer.line < 0: self.initializer.set_line( self.line, self.column, self.end_line, self.end_column) self.variable.set_line( self.line, self.column, self.end_line, self.end_column) FUNCITEM_FLAGS: Final = FUNCBASE_FLAGS + [ 'is_overload', 'is_generator', 'is_coroutine', 'is_async_generator', 'is_awaitable_coroutine', ] class FuncItem(FuncBase): """Base class for nodes usable as overloaded function items.""" __slots__ = ('arguments', # Note that can be unset if deserialized (type is a lie!) 'arg_names', # Names of arguments 'arg_kinds', # Kinds of arguments 'min_args', # Minimum number of arguments 'max_pos', # Maximum number of positional arguments, -1 if no explicit # limit (*args not included) 'body', # Body of the function 'is_overload', # Is this an overload variant of function with more than # one overload variant? 'is_generator', # Contains a yield statement? 'is_coroutine', # Defined using 'async def' syntax? 'is_async_generator', # Is an async def generator? 'is_awaitable_coroutine', # Decorated with '@{typing,asyncio}.coroutine'? 'expanded', # Variants of function with type variables with values expanded ) __deletable__ = ('arguments', 'max_pos', 'min_args') def __init__(self, arguments: Optional[List[Argument]] = None, body: Optional['Block'] = None, typ: 'Optional[mypy.types.FunctionLike]' = None) -> None: super().__init__() self.arguments = arguments or [] self.arg_names = [None if arg.pos_only else arg.variable.name for arg in self.arguments] self.arg_kinds: List[ArgKind] = [arg.kind for arg in self.arguments] self.max_pos: int = ( self.arg_kinds.count(ARG_POS) + self.arg_kinds.count(ARG_OPT)) self.body: 'Block' = body or Block([]) self.type = typ self.unanalyzed_type = typ self.is_overload: bool = False self.is_generator: bool = False self.is_coroutine: bool = False self.is_async_generator: bool = False self.is_awaitable_coroutine: bool = False self.expanded: List[FuncItem] = [] self.min_args = 0 for i in range(len(self.arguments)): if self.arguments[i] is None and i < self.max_fixed_argc(): self.min_args = i + 1 def max_fixed_argc(self) -> int: return self.max_pos def set_line(self, target: Union[Context, int], column: Optional[int] = None, end_line: Optional[int] = None, end_column: Optional[int] = None) -> None: super().set_line(target, column, end_line, end_column) for arg in self.arguments: arg.set_line(self.line, self.column, self.end_line, end_column) def is_dynamic(self) -> bool: return self.type is None FUNCDEF_FLAGS: Final = FUNCITEM_FLAGS + [ 'is_decorated', 'is_conditional', 'is_abstract', ] class FuncDef(FuncItem, SymbolNode, Statement): """Function definition. This is a non-lambda function defined using 'def'. """ __slots__ = ('_name', 'is_decorated', 'is_conditional', 'is_abstract', 'original_def', ) # Note that all __init__ args must have default values def __init__(self, name: str = '', # Function name arguments: Optional[List[Argument]] = None, body: Optional['Block'] = None, typ: 'Optional[mypy.types.FunctionLike]' = None) -> None: super().__init__(arguments, body, typ) self._name = name self.is_decorated = False self.is_conditional = False # Defined conditionally (within block)? self.is_abstract = False self.is_final = False # Original conditional definition self.original_def: Union[None, FuncDef, Var, Decorator] = None @property def name(self) -> str: return self._name def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_func_def(self) def serialize(self) -> JsonDict: # We're deliberating omitting arguments and storing only arg_names and # arg_kinds for space-saving reasons (arguments is not used in later # stages of mypy). # TODO: After a FuncDef is deserialized, the only time we use `arg_names` # and `arg_kinds` is when `type` is None and we need to infer a type. Can # we store the inferred type ahead of time? return {'.class': 'FuncDef', 'name': self._name, 'fullname': self._fullname, 'arg_names': self.arg_names, 'arg_kinds': [int(x.value) for x in self.arg_kinds], 'type': None if self.type is None else self.type.serialize(), 'flags': get_flags(self, FUNCDEF_FLAGS), # TODO: Do we need expanded, original_def? } @classmethod def deserialize(cls, data: JsonDict) -> 'FuncDef': assert data['.class'] == 'FuncDef' body = Block([]) ret = FuncDef(data['name'], [], body, (None if data['type'] is None else cast(mypy.types.FunctionLike, mypy.types.deserialize_type(data['type'])))) ret._fullname = data['fullname'] set_flags(ret, data['flags']) # NOTE: ret.info is set in the fixup phase. ret.arg_names = data['arg_names'] ret.arg_kinds = [ArgKind(x) for x in data['arg_kinds']] # Leave these uninitialized so that future uses will trigger an error del ret.arguments del ret.max_pos del ret.min_args return ret # All types that are both SymbolNodes and FuncBases. See the FuncBase # docstring for the rationale. SYMBOL_FUNCBASE_TYPES = (OverloadedFuncDef, FuncDef) class Decorator(SymbolNode, Statement): """A decorated function. A single Decorator object can include any number of function decorators. """ __slots__ = ('func', 'decorators', 'original_decorators', 'var', 'is_overload') func: FuncDef # Decorated function decorators: List[Expression] # Decorators (may be empty) # Some decorators are removed by semanal, keep the original here. original_decorators: List[Expression] # TODO: This is mostly used for the type; consider replacing with a 'type' attribute var: "Var" # Represents the decorated function obj is_overload: bool def __init__(self, func: FuncDef, decorators: List[Expression], var: 'Var') -> None: super().__init__() self.func = func self.decorators = decorators self.original_decorators = decorators.copy() self.var = var self.is_overload = False @property def name(self) -> str: return self.func.name @property def fullname(self) -> Bogus[str]: return self.func.fullname @property def is_final(self) -> bool: return self.func.is_final @property def info(self) -> 'TypeInfo': return self.func.info @property def type(self) -> 'Optional[mypy.types.Type]': return self.var.type def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_decorator(self) def serialize(self) -> JsonDict: return {'.class': 'Decorator', 'func': self.func.serialize(), 'var': self.var.serialize(), 'is_overload': self.is_overload, } @classmethod def deserialize(cls, data: JsonDict) -> 'Decorator': assert data['.class'] == 'Decorator' dec = Decorator(FuncDef.deserialize(data['func']), [], Var.deserialize(data['var'])) dec.is_overload = data['is_overload'] return dec VAR_FLAGS: Final = [ 'is_self', 'is_initialized_in_class', 'is_staticmethod', 'is_classmethod', 'is_property', 'is_settable_property', 'is_suppressed_import', 'is_classvar', 'is_abstract_var', 'is_final', 'final_unset_in_class', 'final_set_in_init', 'explicit_self_type', 'is_ready', 'from_module_getattr', 'has_explicit_value', 'allow_incompatible_override', ] class Var(SymbolNode): """A variable. It can refer to global/local variable or a data attribute. """ __slots__ = ('_name', '_fullname', 'info', 'type', 'final_value', 'is_self', 'is_ready', 'is_inferred', 'is_initialized_in_class', 'is_staticmethod', 'is_classmethod', 'is_property', 'is_settable_property', 'is_classvar', 'is_abstract_var', 'is_final', 'final_unset_in_class', 'final_set_in_init', 'is_suppressed_import', 'explicit_self_type', 'from_module_getattr', 'has_explicit_value', 'allow_incompatible_override', ) def __init__(self, name: str, type: 'Optional[mypy.types.Type]' = None) -> None: super().__init__() self._name = name # Name without module prefix # TODO: Should be Optional[str] self._fullname = cast('Bogus[str]', None) # Name with module prefix # TODO: Should be Optional[TypeInfo] self.info = VAR_NO_INFO self.type: Optional[mypy.types.Type] = type # Declared or inferred type, or None # Is this the first argument to an ordinary method (usually "self")? self.is_self = False self.is_ready = True # If inferred, is the inferred type available? self.is_inferred = (self.type is None) # Is this initialized explicitly to a non-None value in class body? self.is_initialized_in_class = False self.is_staticmethod = False self.is_classmethod = False self.is_property = False self.is_settable_property = False self.is_classvar = False self.is_abstract_var = False # Set to true when this variable refers to a module we were unable to # parse for some reason (eg a silenced module) self.is_suppressed_import = False # Was this "variable" (rather a constant) defined as Final[...]? self.is_final = False # If constant value is a simple literal, # store the literal value (unboxed) for the benefit of # tools like mypyc. self.final_value: Optional[Union[int, float, bool, str]] = None # Where the value was set (only for class attributes) self.final_unset_in_class = False self.final_set_in_init = False # This is True for a variable that was declared on self with an explicit type: # class C: # def __init__(self) -> None: # self.x: int # This case is important because this defines a new Var, even if there is one # present in a superclass (without explicit type this doesn't create a new Var). # See SemanticAnalyzer.analyze_member_lvalue() for details. self.explicit_self_type = False # If True, this is an implicit Var created due to module-level __getattr__. self.from_module_getattr = False # Var can be created with an explicit value `a = 1` or without one `a: int`, # we need a way to tell which one is which. self.has_explicit_value = False # If True, subclasses can override this with an incompatible type. self.allow_incompatible_override = False @property def name(self) -> str: return self._name @property def fullname(self) -> Bogus[str]: return self._fullname def accept(self, visitor: NodeVisitor[T]) -> T: return visitor.visit_var(self) def serialize(self) -> JsonDict: # TODO: Leave default values out? # NOTE: Sometimes self.is_ready is False here, but we don't care. data: JsonDict = { ".class": "Var", "name": self._name, "fullname": self._fullname, "type": None if self.type is None else self.type.serialize(), "flags": get_flags(self, VAR_FLAGS), } if self.final_value is not None: data['final_value'] = self.final_value return data @classmethod def deserialize(cls, data: JsonDict) -> 'Var': assert data['.class'] == 'Var' name = data['name'] type = None if data['type'] is None else mypy.types.deserialize_type(data['type']) v = Var(name, type) v.is_ready = False # Override True default set in __init__ v._fullname = data['fullname'] set_flags(v, data['flags']) v.final_value = data.get('final_value') return v class ClassDef(Statement): """Class definition""" __slots__ = ('name', 'fullname', 'defs', 'type_vars', 'base_type_exprs', 'removed_base_type_exprs', 'info', 'metaclass', 'decorators', 'keywords', 'analyzed', 'has_incompatible_baseclass') name: str # Name of the class without module prefix fullname: Bogus[str] # Fully qualified name of the class defs: "Block" type_vars: List["mypy.types.TypeVarLikeType"] # Base class expressions (not semantically analyzed -- can be arbitrary expressions) base_type_exprs: List[Expression] # Special base classes like Generic[...] get moved here during semantic analysis removed_base_type_exprs: List[Expression] info: "TypeInfo" # Related TypeInfo metaclass: Optional[Expression] decorators: List[Expression] keywords: "OrderedDict[str, Expression]" analyzed: Optional[Expression] has_incompatible_baseclass: bool def __init__(self, name: str, defs: 'Block', type_vars: Optional[List['mypy.types.TypeVarLikeType']] = None, base_type_exprs: Optional[List[Expression]] = None, metaclass: Optional[Expression] = None, keywords: Optional[List[Tuple[str, Expression]]] = None) -> None: super().__init__() self.name = name self.fullname = None # type: ignore self.defs = defs self.type_vars = type_vars or [] self.base_type_exprs = base_type_exprs or [] self.removed_base_type_exprs = [] self.info = CLASSDEF_NO_INFO self.metaclass = metaclass self.decorators = [] self.keywords = OrderedDict(keywords or []) self.analyzed = None self.has_incompatible_baseclass = False def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_class_def(self) def is_generic(self) -> bool: return self.info.is_generic() def serialize(self) -> JsonDict: # Not serialized: defs, base_type_exprs, metaclass, decorators, # analyzed (for named tuples etc.) return {'.class': 'ClassDef', 'name': self.name, 'fullname': self.fullname, 'type_vars': [v.serialize() for v in self.type_vars], } @classmethod def deserialize(self, data: JsonDict) -> 'ClassDef': assert data['.class'] == 'ClassDef' res = ClassDef(data['name'], Block([]), # https://github.com/python/mypy/issues/12257 [cast(mypy.types.TypeVarLikeType, mypy.types.deserialize_type(v)) for v in data['type_vars']], ) res.fullname = data['fullname'] return res class GlobalDecl(Statement): """Declaration global x, y, ...""" __slots__ = ('names',) names: List[str] def __init__(self, names: List[str]) -> None: super().__init__() self.names = names def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_global_decl(self) class NonlocalDecl(Statement): """Declaration nonlocal x, y, ...""" __slots__ = ('names',) names: List[str] def __init__(self, names: List[str]) -> None: super().__init__() self.names = names def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_nonlocal_decl(self) class Block(Statement): __slots__ = ('body', 'is_unreachable') def __init__(self, body: List[Statement]) -> None: super().__init__() self.body = body # True if we can determine that this block is not executed during semantic # analysis. For example, this applies to blocks that are protected by # something like "if PY3:" when using Python 2. However, some code is # only considered unreachable during type checking and this is not true # in those cases. self.is_unreachable = False def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_block(self) # Statements class ExpressionStmt(Statement): """An expression as a statement, such as print(s).""" __slots__ = ('expr',) expr: Expression def __init__(self, expr: Expression) -> None: super().__init__() self.expr = expr def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_expression_stmt(self) class AssignmentStmt(Statement): """Assignment statement. The same node class is used for single assignment, multiple assignment (e.g. x, y = z) and chained assignment (e.g. x = y = z), assignments that define new names, and assignments with explicit types ("# type: t" or "x: t [= ...]"). An lvalue can be NameExpr, TupleExpr, ListExpr, MemberExpr, or IndexExpr. """ __slots__ = ('lvalues', 'rvalue', 'type', 'unanalyzed_type', 'new_syntax', 'is_alias_def', 'is_final_def') lvalues: List[Lvalue] # This is a TempNode if and only if no rvalue (x: t). rvalue: Expression # Declared type in a comment, may be None. type: Optional["mypy.types.Type"] # Original, not semantically analyzed type in annotation (used for reprocessing) unanalyzed_type: Optional["mypy.types.Type"] # This indicates usage of PEP 526 type annotation syntax in assignment. new_syntax: bool # Does this assignment define a type alias? is_alias_def: bool # Is this a final definition? # Final attributes can't be re-assigned once set, and can't be overridden # in a subclass. This flag is not set if an attempted declaration was found to # be invalid during semantic analysis. It is still set to `True` if # a final declaration overrides another final declaration (this is checked # during type checking when MROs are known). is_final_def: bool def __init__(self, lvalues: List[Lvalue], rvalue: Expression, type: 'Optional[mypy.types.Type]' = None, new_syntax: bool = False) -> None: super().__init__() self.lvalues = lvalues self.rvalue = rvalue self.type = type self.unanalyzed_type = type self.new_syntax = new_syntax self.is_alias_def = False self.is_final_def = False def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_assignment_stmt(self) class OperatorAssignmentStmt(Statement): """Operator assignment statement such as x += 1""" __slots__ = ('op', 'lvalue', 'rvalue') op: str # TODO: Enum? lvalue: Lvalue rvalue: Expression def __init__(self, op: str, lvalue: Lvalue, rvalue: Expression) -> None: super().__init__() self.op = op self.lvalue = lvalue self.rvalue = rvalue def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_operator_assignment_stmt(self) class WhileStmt(Statement): __slots__ = ('expr', 'body', 'else_body') expr: Expression body: Block else_body: Optional[Block] def __init__(self, expr: Expression, body: Block, else_body: Optional[Block]) -> None: super().__init__() self.expr = expr self.body = body self.else_body = else_body def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_while_stmt(self) class ForStmt(Statement): __slots__ = ('index', 'index_type', 'unanalyzed_index_type', 'inferred_item_type', 'inferred_iterator_type', 'expr', 'body', 'else_body', 'is_async') # Index variables index: Lvalue # Type given by type comments for index, can be None index_type: Optional["mypy.types.Type"] # Original, not semantically analyzed type in annotation (used for reprocessing) unanalyzed_index_type: Optional["mypy.types.Type"] # Inferred iterable item type inferred_item_type: Optional["mypy.types.Type"] # Inferred iterator type inferred_iterator_type: Optional["mypy.types.Type"] # Expression to iterate expr: Expression body: Block else_body: Optional[Block] is_async: bool # True if `async for ...` (PEP 492, Python 3.5) def __init__(self, index: Lvalue, expr: Expression, body: Block, else_body: Optional[Block], index_type: 'Optional[mypy.types.Type]' = None) -> None: super().__init__() self.index = index self.index_type = index_type self.unanalyzed_index_type = index_type self.inferred_item_type = None self.inferred_iterator_type = None self.expr = expr self.body = body self.else_body = else_body self.is_async = False def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_for_stmt(self) class ReturnStmt(Statement): __slots__ = ('expr',) expr: Optional[Expression] def __init__(self, expr: Optional[Expression]) -> None: super().__init__() self.expr = expr def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_return_stmt(self) class AssertStmt(Statement): __slots__ = ('expr', 'msg') expr: Expression msg: Optional[Expression] def __init__(self, expr: Expression, msg: Optional[Expression] = None) -> None: super().__init__() self.expr = expr self.msg = msg def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_assert_stmt(self) class DelStmt(Statement): __slots__ = ('expr',) expr: Lvalue def __init__(self, expr: Lvalue) -> None: super().__init__() self.expr = expr def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_del_stmt(self) class BreakStmt(Statement): __slots__ = () def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_break_stmt(self) class ContinueStmt(Statement): __slots__ = () def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_continue_stmt(self) class PassStmt(Statement): __slots__ = () def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_pass_stmt(self) class IfStmt(Statement): __slots__ = ('expr', 'body', 'else_body') expr: List[Expression] body: List[Block] else_body: Optional[Block] def __init__(self, expr: List[Expression], body: List[Block], else_body: Optional[Block]) -> None: super().__init__() self.expr = expr self.body = body self.else_body = else_body def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_if_stmt(self) class RaiseStmt(Statement): __slots__ = ('expr', 'from_expr', 'legacy_mode') # Plain 'raise' is a valid statement. expr: Optional[Expression] from_expr: Optional[Expression] # Is set when python2 has `raise exc, msg, traceback`. legacy_mode: bool def __init__(self, expr: Optional[Expression], from_expr: Optional[Expression]) -> None: super().__init__() self.expr = expr self.from_expr = from_expr self.legacy_mode = False def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_raise_stmt(self) class TryStmt(Statement): __slots__ = ('body', 'types', 'vars', 'handlers', 'else_body', 'finally_body') body: Block # Try body # Plain 'except:' also possible types: List[Optional[Expression]] # Except type expressions vars: List[Optional["NameExpr"]] # Except variable names handlers: List[Block] # Except bodies else_body: Optional[Block] finally_body: Optional[Block] def __init__(self, body: Block, vars: List['Optional[NameExpr]'], types: List[Optional[Expression]], handlers: List[Block], else_body: Optional[Block], finally_body: Optional[Block]) -> None: super().__init__() self.body = body self.vars = vars self.types = types self.handlers = handlers self.else_body = else_body self.finally_body = finally_body def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_try_stmt(self) class WithStmt(Statement): __slots__ = ('expr', 'target', 'unanalyzed_type', 'analyzed_types', 'body', 'is_async') expr: List[Expression] target: List[Optional[Lvalue]] # Type given by type comments for target, can be None unanalyzed_type: Optional["mypy.types.Type"] # Semantically analyzed types from type comment (TypeList type expanded) analyzed_types: List["mypy.types.Type"] body: Block is_async: bool # True if `async with ...` (PEP 492, Python 3.5) def __init__(self, expr: List[Expression], target: List[Optional[Lvalue]], body: Block, target_type: 'Optional[mypy.types.Type]' = None) -> None: super().__init__() self.expr = expr self.target = target self.unanalyzed_type = target_type self.analyzed_types = [] self.body = body self.is_async = False def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_with_stmt(self) class MatchStmt(Statement): subject: Expression patterns: List['Pattern'] guards: List[Optional[Expression]] bodies: List[Block] def __init__(self, subject: Expression, patterns: List['Pattern'], guards: List[Optional[Expression]], bodies: List[Block]) -> None: super().__init__() assert len(patterns) == len(guards) == len(bodies) self.subject = subject self.patterns = patterns self.guards = guards self.bodies = bodies def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_match_stmt(self) class PrintStmt(Statement): """Python 2 print statement""" __slots__ = ('args', 'newline', 'target') args: List[Expression] newline: bool # The file-like target object (given using >>). target: Optional[Expression] def __init__(self, args: List[Expression], newline: bool, target: Optional[Expression] = None) -> None: super().__init__() self.args = args self.newline = newline self.target = target def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_print_stmt(self) class ExecStmt(Statement): """Python 2 exec statement""" __slots__ = ('expr', 'globals', 'locals') expr: Expression globals: Optional[Expression] locals: Optional[Expression] def __init__(self, expr: Expression, globals: Optional[Expression], locals: Optional[Expression]) -> None: super().__init__() self.expr = expr self.globals = globals self.locals = locals def accept(self, visitor: StatementVisitor[T]) -> T: return visitor.visit_exec_stmt(self) # Expressions class IntExpr(Expression): """Integer literal""" __slots__ = ('value',) value: int # 0 by default def __init__(self, value: int) -> None: super().__init__() self.value = value def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_int_expr(self) # How mypy uses StrExpr, BytesExpr, and UnicodeExpr: # In Python 2 mode: # b'x', 'x' -> StrExpr # u'x' -> UnicodeExpr # BytesExpr is unused # # In Python 3 mode: # b'x' -> BytesExpr # 'x', u'x' -> StrExpr # UnicodeExpr is unused class StrExpr(Expression): """String literal""" __slots__ = ('value', 'from_python_3') value: str # '' by default # Keeps track of whether this string originated from Python 2 source code vs # Python 3 source code. We need to keep track of this information so we can # correctly handle types that have "nested strings". For example, consider this # type alias, where we have a forward reference to a literal type: # # Alias = List["Literal['foo']"] # # When parsing this, we need to know whether the outer string and alias came from # Python 2 code vs Python 3 code so we can determine whether the inner `Literal['foo']` # is meant to be `Literal[u'foo']` or `Literal[b'foo']`. # # This field keeps track of that information. from_python_3: bool def __init__(self, value: str, from_python_3: bool = False) -> None: super().__init__() self.value = value self.from_python_3 = from_python_3 def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_str_expr(self) class BytesExpr(Expression): """Bytes literal""" __slots__ = ('value',) # Note: we deliberately do NOT use bytes here because it ends up # unnecessarily complicating a lot of the result logic. For example, # we'd have to worry about converting the bytes into a format we can # easily serialize/deserialize to and from JSON, would have to worry # about turning the bytes into a human-readable representation in # error messages... # # It's more convenient to just store the human-readable representation # from the very start. value: str def __init__(self, value: str) -> None: super().__init__() self.value = value def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_bytes_expr(self) class UnicodeExpr(Expression): """Unicode literal (Python 2.x)""" __slots__ = ('value',) value: str def __init__(self, value: str) -> None: super().__init__() self.value = value def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_unicode_expr(self) class FloatExpr(Expression): """Float literal""" __slots__ = ('value',) value: float # 0.0 by default def __init__(self, value: float) -> None: super().__init__() self.value = value def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_float_expr(self) class ComplexExpr(Expression): """Complex literal""" __slots__ = ('value',) value: complex def __init__(self, value: complex) -> None: super().__init__() self.value = value def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_complex_expr(self) class EllipsisExpr(Expression): """Ellipsis (...)""" __slots__ = () def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_ellipsis(self) class StarExpr(Expression): """Star expression""" __slots__ = ('expr', 'valid') expr: Expression valid: bool def __init__(self, expr: Expression) -> None: super().__init__() self.expr = expr # Whether this starred expression is used in a tuple/list and as lvalue self.valid = False def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_star_expr(self) class RefExpr(Expression): """Abstract base class for name-like constructs""" __slots__ = ('kind', 'node', 'fullname', 'is_new_def', 'is_inferred_def', 'is_alias_rvalue', 'type_guard') def __init__(self) -> None: super().__init__() # LDEF/GDEF/MDEF/... (None if not available) self.kind: Optional[int] = None # Var, FuncDef or TypeInfo that describes this self.node: Optional[SymbolNode] = None # Fully qualified name (or name if not global) self.fullname: Optional[str] = None # Does this define a new name? self.is_new_def = False # Does this define a new name with inferred type? # # For members, after semantic analysis, this does not take base # classes into consideration at all; the type checker deals with these. self.is_inferred_def = False # Is this expression appears as an rvalue of a valid type alias definition? self.is_alias_rvalue = False # Cache type guard from callable_type.type_guard self.type_guard: Optional["mypy.types.Type"] = None class NameExpr(RefExpr): """Name expression This refers to a local name, global name or a module. """ __slots__ = ('name', 'is_special_form') def __init__(self, name: str) -> None: super().__init__() self.name = name # Name referred to (may be qualified) # Is this a l.h.s. of a special form assignment like typed dict or type variable? self.is_special_form = False def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_name_expr(self) def serialize(self) -> JsonDict: assert False, f"Serializing NameExpr: {self}" class MemberExpr(RefExpr): """Member access expression x.y""" __slots__ = ('expr', 'name', 'def_var') def __init__(self, expr: Expression, name: str) -> None: super().__init__() self.expr = expr self.name = name # The variable node related to a definition through 'self.x = '. # The nodes of other kinds of member expressions are resolved during type checking. self.def_var: Optional[Var] = None def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_member_expr(self) # Kinds of arguments @unique class ArgKind(Enum): # Positional argument ARG_POS = 0 # Positional, optional argument (functions only, not calls) ARG_OPT = 1 # *arg argument ARG_STAR = 2 # Keyword argument x=y in call, or keyword-only function arg ARG_NAMED = 3 # **arg argument ARG_STAR2 = 4 # In an argument list, keyword-only and also optional ARG_NAMED_OPT = 5 def is_positional(self, star: bool = False) -> bool: return ( self == ARG_POS or self == ARG_OPT or (star and self == ARG_STAR) ) def is_named(self, star: bool = False) -> bool: return ( self == ARG_NAMED or self == ARG_NAMED_OPT or (star and self == ARG_STAR2) ) def is_required(self) -> bool: return self == ARG_POS or self == ARG_NAMED def is_optional(self) -> bool: return self == ARG_OPT or self == ARG_NAMED_OPT def is_star(self) -> bool: return self == ARG_STAR or self == ARG_STAR2 ARG_POS: Final = ArgKind.ARG_POS ARG_OPT: Final = ArgKind.ARG_OPT ARG_STAR: Final = ArgKind.ARG_STAR ARG_NAMED: Final = ArgKind.ARG_NAMED ARG_STAR2: Final = ArgKind.ARG_STAR2 ARG_NAMED_OPT: Final = ArgKind.ARG_NAMED_OPT class CallExpr(Expression): """Call expression. This can also represent several special forms that are syntactically calls such as cast(...) and None # type: .... """ __slots__ = ('callee', 'args', 'arg_kinds', 'arg_names', 'analyzed') def __init__(self, callee: Expression, args: List[Expression], arg_kinds: List[ArgKind], arg_names: List[Optional[str]], analyzed: Optional[Expression] = None) -> None: super().__init__() if not arg_names: arg_names = [None] * len(args) self.callee = callee self.args = args self.arg_kinds = arg_kinds # ARG_ constants # Each name can be None if not a keyword argument. self.arg_names: List[Optional[str]] = arg_names # If not None, the node that represents the meaning of the CallExpr. For # cast(...) this is a CastExpr. self.analyzed = analyzed def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_call_expr(self) class YieldFromExpr(Expression): __slots__ = ('expr',) expr: Expression def __init__(self, expr: Expression) -> None: super().__init__() self.expr = expr def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_yield_from_expr(self) class YieldExpr(Expression): __slots__ = ('expr',) expr: Optional[Expression] def __init__(self, expr: Optional[Expression]) -> None: super().__init__() self.expr = expr def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_yield_expr(self) class IndexExpr(Expression): """Index expression x[y]. Also wraps type application such as List[int] as a special form. """ __slots__ = ('base', 'index', 'method_type', 'analyzed') base: Expression index: Expression # Inferred __getitem__ method type method_type: Optional["mypy.types.Type"] # If not None, this is actually semantically a type application # Class[type, ...] or a type alias initializer. analyzed: Union["TypeApplication", "TypeAliasExpr", None] def __init__(self, base: Expression, index: Expression) -> None: super().__init__() self.base = base self.index = index self.method_type = None self.analyzed = None def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_index_expr(self) class UnaryExpr(Expression): """Unary operation""" __slots__ = ('op', 'expr', 'method_type') op: str # TODO: Enum? expr: Expression # Inferred operator method type method_type: Optional["mypy.types.Type"] def __init__(self, op: str, expr: Expression) -> None: super().__init__() self.op = op self.expr = expr self.method_type = None def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_unary_expr(self) class AssignmentExpr(Expression): """Assignment expressions in Python 3.8+, like "a := 2".""" __slots__ = ('target', 'value') def __init__(self, target: Expression, value: Expression) -> None: super().__init__() self.target = target self.value = value def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_assignment_expr(self) class OpExpr(Expression): """Binary operation (other than . or [] or comparison operators, which have specific nodes).""" __slots__ = ('op', 'left', 'right', 'method_type', 'right_always', 'right_unreachable') op: str # TODO: Enum? left: Expression right: Expression # Inferred type for the operator method type (when relevant). method_type: Optional["mypy.types.Type"] # Per static analysis only: Is the right side going to be evaluated every time? right_always: bool # Per static analysis only: Is the right side unreachable? right_unreachable: bool def __init__(self, op: str, left: Expression, right: Expression) -> None: super().__init__() self.op = op self.left = left self.right = right self.method_type = None self.right_always = False self.right_unreachable = False def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_op_expr(self) class ComparisonExpr(Expression): """Comparison expression (e.g. a < b > c < d).""" __slots__ = ('operators', 'operands', 'method_types') operators: List[str] operands: List[Expression] # Inferred type for the operator methods (when relevant; None for 'is'). method_types: List[Optional["mypy.types.Type"]] def __init__(self, operators: List[str], operands: List[Expression]) -> None: super().__init__() self.operators = operators self.operands = operands self.method_types = [] def pairwise(self) -> Iterator[Tuple[str, Expression, Expression]]: """If this comparison expr is "a < b is c == d", yields the sequence ("<", a, b), ("is", b, c), ("==", c, d) """ for i, operator in enumerate(self.operators): yield operator, self.operands[i], self.operands[i + 1] def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_comparison_expr(self) class SliceExpr(Expression): """Slice expression (e.g. 'x:y', 'x:', '::2' or ':'). This is only valid as index in index expressions. """ __slots__ = ('begin_index', 'end_index', 'stride') begin_index: Optional[Expression] end_index: Optional[Expression] stride: Optional[Expression] def __init__(self, begin_index: Optional[Expression], end_index: Optional[Expression], stride: Optional[Expression]) -> None: super().__init__() self.begin_index = begin_index self.end_index = end_index self.stride = stride def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_slice_expr(self) class CastExpr(Expression): """Cast expression cast(type, expr).""" __slots__ = ('expr', 'type') expr: Expression type: "mypy.types.Type" def __init__(self, expr: Expression, typ: 'mypy.types.Type') -> None: super().__init__() self.expr = expr self.type = typ def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_cast_expr(self) class AssertTypeExpr(Expression): """Represents a typing.assert_type(expr, type) call.""" __slots__ = ('expr', 'type') expr: Expression type: "mypy.types.Type" def __init__(self, expr: Expression, typ: 'mypy.types.Type') -> None: super().__init__() self.expr = expr self.type = typ def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_assert_type_expr(self) class RevealExpr(Expression): """Reveal type expression reveal_type(expr) or reveal_locals() expression.""" __slots__ = ('expr', 'kind', 'local_nodes') expr: Optional[Expression] kind: int local_nodes: Optional[List[Var]] def __init__( self, kind: int, expr: Optional[Expression] = None, local_nodes: 'Optional[List[Var]]' = None) -> None: super().__init__() self.expr = expr self.kind = kind self.local_nodes = local_nodes def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_reveal_expr(self) class SuperExpr(Expression): """Expression super().name""" __slots__ = ('name', 'info', 'call') name: str info: Optional["TypeInfo"] # Type that contains this super expression call: CallExpr # The expression super(...) def __init__(self, name: str, call: CallExpr) -> None: super().__init__() self.name = name self.call = call self.info = None def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_super_expr(self) class LambdaExpr(FuncItem, Expression): """Lambda expression""" @property def name(self) -> str: return '' def expr(self) -> Expression: """Return the expression (the body) of the lambda.""" ret = cast(ReturnStmt, self.body.body[-1]) expr = ret.expr assert expr is not None # lambda can't have empty body return expr def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_lambda_expr(self) def is_dynamic(self) -> bool: return False class ListExpr(Expression): """List literal expression [...].""" __slots__ = ('items',) items: List[Expression] def __init__(self, items: List[Expression]) -> None: super().__init__() self.items = items def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_list_expr(self) class DictExpr(Expression): """Dictionary literal expression {key: value, ...}.""" __slots__ = ('items',) items: List[Tuple[Optional[Expression], Expression]] def __init__(self, items: List[Tuple[Optional[Expression], Expression]]) -> None: super().__init__() self.items = items def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_dict_expr(self) class TupleExpr(Expression): """Tuple literal expression (..., ...) Also lvalue sequences (..., ...) and [..., ...]""" __slots__ = ('items',) items: List[Expression] def __init__(self, items: List[Expression]) -> None: super().__init__() self.items = items def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_tuple_expr(self) class SetExpr(Expression): """Set literal expression {value, ...}.""" __slots__ = ('items',) items: List[Expression] def __init__(self, items: List[Expression]) -> None: super().__init__() self.items = items def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_set_expr(self) class GeneratorExpr(Expression): """Generator expression ... for ... in ... [ for ... in ... ] [ if ... ].""" __slots__ = ('left_expr', 'sequences', 'condlists', 'is_async', 'indices') left_expr: Expression sequences: List[Expression] condlists: List[List[Expression]] is_async: List[bool] indices: List[Lvalue] def __init__(self, left_expr: Expression, indices: List[Lvalue], sequences: List[Expression], condlists: List[List[Expression]], is_async: List[bool]) -> None: super().__init__() self.left_expr = left_expr self.sequences = sequences self.condlists = condlists self.indices = indices self.is_async = is_async def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_generator_expr(self) class ListComprehension(Expression): """List comprehension (e.g. [x + 1 for x in a])""" __slots__ = ('generator',) generator: GeneratorExpr def __init__(self, generator: GeneratorExpr) -> None: super().__init__() self.generator = generator def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_list_comprehension(self) class SetComprehension(Expression): """Set comprehension (e.g. {x + 1 for x in a})""" __slots__ = ('generator',) generator: GeneratorExpr def __init__(self, generator: GeneratorExpr) -> None: super().__init__() self.generator = generator def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_set_comprehension(self) class DictionaryComprehension(Expression): """Dictionary comprehension (e.g. {k: v for k, v in a}""" __slots__ = ('key', 'value', 'sequences', 'condlists', 'is_async', 'indices') key: Expression value: Expression sequences: List[Expression] condlists: List[List[Expression]] is_async: List[bool] indices: List[Lvalue] def __init__(self, key: Expression, value: Expression, indices: List[Lvalue], sequences: List[Expression], condlists: List[List[Expression]], is_async: List[bool]) -> None: super().__init__() self.key = key self.value = value self.sequences = sequences self.condlists = condlists self.indices = indices self.is_async = is_async def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_dictionary_comprehension(self) class ConditionalExpr(Expression): """Conditional expression (e.g. x if y else z)""" __slots__ = ('cond', 'if_expr', 'else_expr') cond: Expression if_expr: Expression else_expr: Expression def __init__(self, cond: Expression, if_expr: Expression, else_expr: Expression) -> None: super().__init__() self.cond = cond self.if_expr = if_expr self.else_expr = else_expr def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_conditional_expr(self) class BackquoteExpr(Expression): """Python 2 expression `...`.""" __slots__ = ('expr',) expr: Expression def __init__(self, expr: Expression) -> None: super().__init__() self.expr = expr def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_backquote_expr(self) class TypeApplication(Expression): """Type application expr[type, ...]""" __slots__ = ('expr', 'types') expr: Expression types: List["mypy.types.Type"] def __init__(self, expr: Expression, types: List['mypy.types.Type']) -> None: super().__init__() self.expr = expr self.types = types def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_type_application(self) # Variance of a type variable. For example, T in the definition of # List[T] is invariant, so List[int] is not a subtype of List[object], # and also List[object] is not a subtype of List[int]. # # The T in Iterable[T] is covariant, so Iterable[int] is a subtype of # Iterable[object], but not vice versa. # # If T is contravariant in Foo[T], Foo[object] is a subtype of # Foo[int], but not vice versa. INVARIANT: Final = 0 COVARIANT: Final = 1 CONTRAVARIANT: Final = 2 class TypeVarLikeExpr(SymbolNode, Expression): """Base class for TypeVarExpr, ParamSpecExpr and TypeVarTupleExpr. Note that they are constructed by the semantic analyzer. """ __slots__ = ('_name', '_fullname', 'upper_bound', 'variance') _name: str _fullname: str # Upper bound: only subtypes of upper_bound are valid as values. By default # this is 'object', meaning no restriction. upper_bound: "mypy.types.Type" # Variance of the type variable. Invariant is the default. # TypeVar(..., covariant=True) defines a covariant type variable. # TypeVar(..., contravariant=True) defines a contravariant type # variable. variance: int def __init__( self, name: str, fullname: str, upper_bound: 'mypy.types.Type', variance: int = INVARIANT ) -> None: super().__init__() self._name = name self._fullname = fullname self.upper_bound = upper_bound self.variance = variance @property def name(self) -> str: return self._name @property def fullname(self) -> str: return self._fullname class TypeVarExpr(TypeVarLikeExpr): """Type variable expression TypeVar(...). This is also used to represent type variables in symbol tables. A type variable is not valid as a type unless bound in a TypeVarLikeScope. That happens within: 1. a generic class that uses the type variable as a type argument or 2. a generic function that refers to the type variable in its signature. """ __slots__ = ('values',) # Value restriction: only types in the list are valid as values. If the # list is empty, there is no restriction. values: List["mypy.types.Type"] def __init__(self, name: str, fullname: str, values: List['mypy.types.Type'], upper_bound: 'mypy.types.Type', variance: int = INVARIANT) -> None: super().__init__(name, fullname, upper_bound, variance) self.values = values def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_type_var_expr(self) def serialize(self) -> JsonDict: return {'.class': 'TypeVarExpr', 'name': self._name, 'fullname': self._fullname, 'values': [t.serialize() for t in self.values], 'upper_bound': self.upper_bound.serialize(), 'variance': self.variance, } @classmethod def deserialize(cls, data: JsonDict) -> 'TypeVarExpr': assert data['.class'] == 'TypeVarExpr' return TypeVarExpr(data['name'], data['fullname'], [mypy.types.deserialize_type(v) for v in data['values']], mypy.types.deserialize_type(data['upper_bound']), data['variance']) class ParamSpecExpr(TypeVarLikeExpr): __slots__ = () def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_paramspec_expr(self) def serialize(self) -> JsonDict: return { '.class': 'ParamSpecExpr', 'name': self._name, 'fullname': self._fullname, 'upper_bound': self.upper_bound.serialize(), 'variance': self.variance, } @classmethod def deserialize(cls, data: JsonDict) -> 'ParamSpecExpr': assert data['.class'] == 'ParamSpecExpr' return ParamSpecExpr( data['name'], data['fullname'], mypy.types.deserialize_type(data['upper_bound']), data['variance'] ) class TypeVarTupleExpr(TypeVarLikeExpr): """Type variable tuple expression TypeVarTuple(...).""" __slots__ = () def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_type_var_tuple_expr(self) def serialize(self) -> JsonDict: return { '.class': 'TypeVarTupleExpr', 'name': self._name, 'fullname': self._fullname, 'upper_bound': self.upper_bound.serialize(), 'variance': self.variance, } @classmethod def deserialize(cls, data: JsonDict) -> 'TypeVarTupleExpr': assert data['.class'] == 'TypeVarTupleExpr' return TypeVarTupleExpr( data['name'], data['fullname'], mypy.types.deserialize_type(data['upper_bound']), data['variance'] ) class TypeAliasExpr(Expression): """Type alias expression (rvalue).""" __slots__ = ('type', 'tvars', 'no_args', 'node') # The target type. type: "mypy.types.Type" # Names of unbound type variables used to define the alias tvars: List[str] # Whether this alias was defined in bare form. Used to distinguish # between # A = List # and # A = List[Any] no_args: bool node: 'TypeAlias' def __init__(self, node: 'TypeAlias') -> None: super().__init__() self.type = node.target self.tvars = node.alias_tvars self.no_args = node.no_args self.node = node def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_type_alias_expr(self) class NamedTupleExpr(Expression): """Named tuple expression namedtuple(...) or NamedTuple(...).""" __slots__ = ('info', 'is_typed') # The class representation of this named tuple (its tuple_type attribute contains # the tuple item types) info: "TypeInfo" is_typed: bool # whether this class was created with typing.NamedTuple def __init__(self, info: 'TypeInfo', is_typed: bool = False) -> None: super().__init__() self.info = info self.is_typed = is_typed def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_namedtuple_expr(self) class TypedDictExpr(Expression): """Typed dict expression TypedDict(...).""" __slots__ = ('info',) # The class representation of this typed dict info: "TypeInfo" def __init__(self, info: 'TypeInfo') -> None: super().__init__() self.info = info def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_typeddict_expr(self) class EnumCallExpr(Expression): """Named tuple expression Enum('name', 'val1 val2 ...').""" __slots__ = ('info', 'items', 'values') # The class representation of this enumerated type info: "TypeInfo" # The item names (for debugging) items: List[str] values: List[Optional[Expression]] def __init__(self, info: 'TypeInfo', items: List[str], values: List[Optional[Expression]]) -> None: super().__init__() self.info = info self.items = items self.values = values def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_enum_call_expr(self) class PromoteExpr(Expression): """Ducktype class decorator expression _promote(...).""" __slots__ = ('type',) type: "mypy.types.Type" def __init__(self, type: 'mypy.types.Type') -> None: super().__init__() self.type = type def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit__promote_expr(self) class NewTypeExpr(Expression): """NewType expression NewType(...).""" __slots__ = ('name', 'old_type', 'info') name: str # The base type (the second argument to NewType) old_type: Optional["mypy.types.Type"] # The synthesized class representing the new type (inherits old_type) info: Optional["TypeInfo"] def __init__(self, name: str, old_type: 'Optional[mypy.types.Type]', line: int, column: int) -> None: super().__init__(line=line, column=column) self.name = name self.old_type = old_type self.info = None def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_newtype_expr(self) class AwaitExpr(Expression): """Await expression (await ...).""" __slots__ = ('expr',) expr: Expression def __init__(self, expr: Expression) -> None: super().__init__() self.expr = expr def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_await_expr(self) # Constants class TempNode(Expression): """Temporary dummy node used during type checking. This node is not present in the original program; it is just an artifact of the type checker implementation. It only represents an opaque node with some fixed type. """ __slots__ = ('type', 'no_rhs') type: "mypy.types.Type" # Is this TempNode used to indicate absence of a right hand side in an annotated assignment? # (e.g. for 'x: int' the rvalue is TempNode(AnyType(TypeOfAny.special_form), no_rhs=True)) no_rhs: bool def __init__(self, typ: 'mypy.types.Type', no_rhs: bool = False, *, context: Optional[Context] = None) -> None: """Construct a dummy node; optionally borrow line/column from context object.""" super().__init__() self.type = typ self.no_rhs = no_rhs if context is not None: self.line = context.line self.column = context.column def __repr__(self) -> str: return 'TempNode:%d(%s)' % (self.line, str(self.type)) def accept(self, visitor: ExpressionVisitor[T]) -> T: return visitor.visit_temp_node(self) class TypeInfo(SymbolNode): """The type structure of a single class. Each TypeInfo corresponds one-to-one to a ClassDef, which represents the AST of the class. In type-theory terms, this is a "type constructor", and if the class is generic then it will be a type constructor of higher kind. Where the class is used in an actual type, it's in the form of an Instance, which amounts to a type application of the tycon to the appropriate number of arguments. """ __slots__ = ( '_fullname', 'module_name', 'defn', 'mro', '_mro_refs', 'bad_mro', 'is_final', 'declared_metaclass', 'metaclass_type', 'names', 'is_abstract', 'is_protocol', 'runtime_protocol', 'abstract_attributes', 'deletable_attributes', 'slots', 'assuming', 'assuming_proper', 'inferring', 'is_enum', 'fallback_to_any', 'type_vars', 'has_param_spec_type', 'bases', '_promote', 'tuple_type', 'is_named_tuple', 'typeddict_type', 'is_newtype', 'is_intersection', 'metadata', 'alt_promote', ) _fullname: Bogus[str] # Fully qualified name # Fully qualified name for the module this type was defined in. This # information is also in the fullname, but is harder to extract in the # case of nested class definitions. module_name: str defn: ClassDef # Corresponding ClassDef # Method Resolution Order: the order of looking up attributes. The first # value always to refers to this class. mro: List["TypeInfo"] # Used to stash the names of the mro classes temporarily between # deserialization and fixup. See deserialize() for why. _mro_refs: Optional[List[str]] bad_mro: bool # Could not construct full MRO is_final: bool declared_metaclass: Optional["mypy.types.Instance"] metaclass_type: Optional["mypy.types.Instance"] names: "SymbolTable" # Names defined directly in this type is_abstract: bool # Does the class have any abstract attributes? is_protocol: bool # Is this a protocol class? runtime_protocol: bool # Does this protocol support isinstance checks? abstract_attributes: List[str] deletable_attributes: List[str] # Used by mypyc only # Does this type have concrete `__slots__` defined? # If class does not have `__slots__` defined then it is `None`, # if it has empty `__slots__` then it is an empty set. slots: Optional[Set[str]] # The attributes 'assuming' and 'assuming_proper' represent structural subtype matrices. # # In languages with structural subtyping, one can keep a global subtype matrix like this: # . A B C . # A 1 0 0 # B 1 1 1 # C 1 0 1 # . # where 1 indicates that the type in corresponding row is a subtype of the type # in corresponding column. This matrix typically starts filled with all 1's and # a typechecker tries to "disprove" every subtyping relation using atomic (or nominal) types. # However, we don't want to keep this huge global state. Instead, we keep the subtype # information in the form of list of pairs (subtype, supertype) shared by all 'Instance's # with given supertype's TypeInfo. When we enter a subtype check we push a pair in this list # thus assuming that we started with 1 in corresponding matrix element. Such algorithm allows # to treat recursive and mutually recursive protocols and other kinds of complex situations. # # If concurrent/parallel type checking will be added in future, # then there should be one matrix per thread/process to avoid false negatives # during the type checking phase. assuming: List[Tuple["mypy.types.Instance", "mypy.types.Instance"]] assuming_proper: List[Tuple["mypy.types.Instance", "mypy.types.Instance"]] # Ditto for temporary 'inferring' stack of recursive constraint inference. # It contains Instance's of protocol types that appeared as an argument to # constraints.infer_constraints(). We need 'inferring' to avoid infinite recursion for # recursive and mutually recursive protocols. # # We make 'assuming' and 'inferring' attributes here instead of passing they as kwargs, # since this would require to pass them in many dozens of calls. In particular, # there is a dependency infer_constraint -> is_subtype -> is_callable_subtype -> # -> infer_constraints. inferring: List["mypy.types.Instance"] # 'inferring' and 'assuming' can't be made sets, since we need to use # is_same_type to correctly treat unions. # Classes inheriting from Enum shadow their true members with a __getattr__, so we # have to treat them as a special case. is_enum: bool # If true, any unknown attributes should have type 'Any' instead # of generating a type error. This would be true if there is a # base class with type 'Any', but other use cases may be # possible. This is similar to having __getattr__ that returns Any # (and __setattr__), but without the __getattr__ method. fallback_to_any: bool # Information related to type annotations. # Generic type variable names (full names) type_vars: List[str] # Whether this class has a ParamSpec type variable has_param_spec_type: bool # Direct base classes. bases: List["mypy.types.Instance"] # Another type which this type will be treated as a subtype of, # even though it's not a subclass in Python. The non-standard # `@_promote` decorator introduces this, and there are also # several builtin examples, in particular `int` -> `float`. _promote: List["mypy.types.Type"] # This is used for promoting native integer types such as 'i64' to # 'int'. (_promote is used for the other direction.) This only # supports one-step promotions (e.g., i64 -> int, not # i64 -> int -> float, and this isn't used to promote in joins. # # This results in some unintuitive results, such as that even # though i64 is compatible with int and int is compatible with # float, i64 is *not* compatible with float. alt_promote: Optional["TypeInfo"] # Representation of a Tuple[...] base class, if the class has any # (e.g., for named tuples). If this is not None, the actual Type # object used for this class is not an Instance but a TupleType; # the corresponding Instance is set as the fallback type of the # tuple type. tuple_type: Optional["mypy.types.TupleType"] # Is this a named tuple type? is_named_tuple: bool # If this class is defined by the TypedDict type constructor, # then this is not None. typeddict_type: Optional["mypy.types.TypedDictType"] # Is this a newtype type? is_newtype: bool # Is this a synthesized intersection type? is_intersection: bool # This is a dictionary that will be serialized and un-serialized as is. # It is useful for plugins to add their data to save in the cache. metadata: Dict[str, JsonDict] FLAGS: Final = [ 'is_abstract', 'is_enum', 'fallback_to_any', 'is_named_tuple', 'is_newtype', 'is_protocol', 'runtime_protocol', 'is_final', 'is_intersection', ] def __init__(self, names: 'SymbolTable', defn: ClassDef, module_name: str) -> None: """Initialize a TypeInfo.""" super().__init__() self._fullname = defn.fullname self.names = names self.defn = defn self.module_name = module_name self.type_vars = [] self.has_param_spec_type = False self.bases = [] self.mro = [] self._mro_refs = None self.bad_mro = False self.declared_metaclass = None self.metaclass_type = None self.is_abstract = False self.abstract_attributes = [] self.deletable_attributes = [] self.slots = None self.assuming = [] self.assuming_proper = [] self.inferring = [] self.is_protocol = False self.runtime_protocol = False self.add_type_vars() self.is_final = False self.is_enum = False self.fallback_to_any = False self._promote = [] self.alt_promote = None self.tuple_type = None self.is_named_tuple = False self.typeddict_type = None self.is_newtype = False self.is_intersection = False self.metadata = {} def add_type_vars(self) -> None: if self.defn.type_vars: for vd in self.defn.type_vars: if isinstance(vd, mypy.types.ParamSpecType): self.has_param_spec_type = True self.type_vars.append(vd.name) @property def name(self) -> str: """Short name.""" return self.defn.name @property def fullname(self) -> Bogus[str]: return self._fullname def is_generic(self) -> bool: """Is the type generic (i.e. does it have type variables)?""" return len(self.type_vars) > 0 def get(self, name: str) -> 'Optional[SymbolTableNode]': for cls in self.mro: n = cls.names.get(name) if n: return n return None def get_containing_type_info(self, name: str) -> 'Optional[TypeInfo]': for cls in self.mro: if name in cls.names: return cls return None @property def protocol_members(self) -> List[str]: # Protocol members are names of all attributes/methods defined in a protocol # and in all its supertypes (except for 'object'). members: Set[str] = set() assert self.mro, "This property can be only accessed after MRO is (re-)calculated" for base in self.mro[:-1]: # we skip "object" since everyone implements it if base.is_protocol: for name in base.names: members.add(name) return sorted(list(members)) def __getitem__(self, name: str) -> 'SymbolTableNode': n = self.get(name) if n: return n else: raise KeyError(name) def __repr__(self) -> str: return f'' def __bool__(self) -> bool: # We defined this here instead of just overriding it in # FakeInfo so that mypyc can generate a direct call instead of # using the generic bool handling. return not isinstance(self, FakeInfo) def has_readable_member(self, name: str) -> bool: return self.get(name) is not None def get_method(self, name: str) -> Union[FuncBase, Decorator, None]: for cls in self.mro: if name in cls.names: node = cls.names[name].node if isinstance(node, FuncBase): return node elif isinstance(node, Decorator): # Two `if`s make `mypyc` happy return node else: return None return None def calculate_metaclass_type(self) -> 'Optional[mypy.types.Instance]': declared = self.declared_metaclass if declared is not None and not declared.type.has_base('builtins.type'): return declared if self._fullname == 'builtins.type': return mypy.types.Instance(self, []) candidates = [s.declared_metaclass for s in self.mro if s.declared_metaclass is not None and s.declared_metaclass.type is not None] for c in candidates: if all(other.type in c.type.mro for other in candidates): return c return None def is_metaclass(self) -> bool: return (self.has_base('builtins.type') or self.fullname == 'abc.ABCMeta' or self.fallback_to_any) def has_base(self, fullname: str) -> bool: """Return True if type has a base type with the specified name. This can be either via extension or via implementation. """ for cls in self.mro: if cls.fullname == fullname: return True return False def direct_base_classes(self) -> 'List[TypeInfo]': """Return a direct base classes. Omit base classes of other base classes. """ return [base.type for base in self.bases] def __str__(self) -> str: """Return a string representation of the type. This includes the most important information about the type. """ return self.dump() def dump(self, str_conv: 'Optional[mypy.strconv.StrConv]' = None, type_str_conv: 'Optional[mypy.types.TypeStrVisitor]' = None) -> str: """Return a string dump of the contents of the TypeInfo.""" if not str_conv: str_conv = mypy.strconv.StrConv() base: str = "" def type_str(typ: 'mypy.types.Type') -> str: if type_str_conv: return typ.accept(type_str_conv) return str(typ) head = 'TypeInfo' + str_conv.format_id(self) if self.bases: base = f"Bases({', '.join(type_str(base) for base in self.bases)})" mro = 'Mro({})'.format(', '.join(item.fullname + str_conv.format_id(item) for item in self.mro)) names = [] for name in sorted(self.names): description = name + str_conv.format_id(self.names[name].node) node = self.names[name].node if isinstance(node, Var) and node.type: description += f' ({type_str(node.type)})' names.append(description) items = [ f'Name({self.fullname})', base, mro, ('Names', names), ] if self.declared_metaclass: items.append(f'DeclaredMetaclass({type_str(self.declared_metaclass)})') if self.metaclass_type: items.append(f'MetaclassType({type_str(self.metaclass_type)})') return mypy.strconv.dump_tagged( items, head, str_conv=str_conv) def serialize(self) -> JsonDict: # NOTE: This is where all ClassDefs originate, so there shouldn't be duplicates. data = {'.class': 'TypeInfo', 'module_name': self.module_name, 'fullname': self.fullname, 'names': self.names.serialize(self.fullname), 'defn': self.defn.serialize(), 'abstract_attributes': self.abstract_attributes, 'type_vars': self.type_vars, 'has_param_spec_type': self.has_param_spec_type, 'bases': [b.serialize() for b in self.bases], 'mro': [c.fullname for c in self.mro], '_promote': [p.serialize() for p in self._promote], 'declared_metaclass': (None if self.declared_metaclass is None else self.declared_metaclass.serialize()), 'metaclass_type': None if self.metaclass_type is None else self.metaclass_type.serialize(), 'tuple_type': None if self.tuple_type is None else self.tuple_type.serialize(), 'typeddict_type': None if self.typeddict_type is None else self.typeddict_type.serialize(), 'flags': get_flags(self, TypeInfo.FLAGS), 'metadata': self.metadata, 'slots': list(sorted(self.slots)) if self.slots is not None else None, 'deletable_attributes': self.deletable_attributes, } return data @classmethod def deserialize(cls, data: JsonDict) -> 'TypeInfo': names = SymbolTable.deserialize(data['names']) defn = ClassDef.deserialize(data['defn']) module_name = data['module_name'] ti = TypeInfo(names, defn, module_name) ti._fullname = data['fullname'] # TODO: Is there a reason to reconstruct ti.subtypes? ti.abstract_attributes = data['abstract_attributes'] ti.type_vars = data['type_vars'] ti.has_param_spec_type = data['has_param_spec_type'] ti.bases = [mypy.types.Instance.deserialize(b) for b in data['bases']] ti._promote = [mypy.types.deserialize_type(p) for p in data['_promote']] ti.declared_metaclass = (None if data['declared_metaclass'] is None else mypy.types.Instance.deserialize(data['declared_metaclass'])) ti.metaclass_type = (None if data['metaclass_type'] is None else mypy.types.Instance.deserialize(data['metaclass_type'])) # NOTE: ti.mro will be set in the fixup phase based on these # names. The reason we need to store the mro instead of just # recomputing it from base classes has to do with a subtle # point about fine-grained incremental: the cache files might # not be loaded until after a class in the mro has changed its # bases, which causes the mro to change. If we recomputed our # mro, we would compute the *new* mro, which leaves us with no # way to detect that the mro has changed! Thus we need to make # sure to load the original mro so that once the class is # rechecked, it can tell that the mro has changed. ti._mro_refs = data['mro'] ti.tuple_type = (None if data['tuple_type'] is None else mypy.types.TupleType.deserialize(data['tuple_type'])) ti.typeddict_type = (None if data['typeddict_type'] is None else mypy.types.TypedDictType.deserialize(data['typeddict_type'])) ti.metadata = data['metadata'] ti.slots = set(data['slots']) if data['slots'] is not None else None ti.deletable_attributes = data['deletable_attributes'] set_flags(ti, data['flags']) return ti class FakeInfo(TypeInfo): __slots__ = ('msg',) # types.py defines a single instance of this class, called types.NOT_READY. # This instance is used as a temporary placeholder in the process of de-serialization # of 'Instance' types. The de-serialization happens in two steps: In the first step, # Instance.type is set to NOT_READY. In the second step (in fixup.py) it is replaced by # an actual TypeInfo. If you see the assertion error below, then most probably something # went wrong during the second step and an 'Instance' that raised this error was not fixed. # Note: # 'None' is not used as a dummy value for two reasons: # 1. This will require around 80-100 asserts to make 'mypy --strict-optional mypy' # pass cleanly. # 2. If NOT_READY value is accidentally used somewhere, it will be obvious where the value # is from, whereas a 'None' value could come from anywhere. # # Additionally, this serves as a more general-purpose placeholder # for missing TypeInfos in a number of places where the excuses # for not being Optional are a little weaker. # # TypeInfo defines a __bool__ method that returns False for FakeInfo # so that it can be conveniently tested against in the same way that it # would be if things were properly optional. def __init__(self, msg: str) -> None: self.msg = msg def __getattribute__(self, attr: str) -> None: # Handle __class__ so that isinstance still works... if attr == '__class__': return object.__getattribute__(self, attr) raise AssertionError(object.__getattribute__(self, 'msg')) VAR_NO_INFO: Final[TypeInfo] = FakeInfo("Var is lacking info") CLASSDEF_NO_INFO: Final[TypeInfo] = FakeInfo("ClassDef is lacking info") FUNC_NO_INFO: Final[TypeInfo] = FakeInfo("FuncBase for non-methods lack info") class TypeAlias(SymbolNode): """ A symbol node representing a type alias. Type alias is a static concept, in contrast to variables with types like Type[...]. Namely: * type aliases - can be used in type context (annotations) - cannot be re-assigned * variables with type Type[...] - cannot be used in type context - but can be re-assigned An alias can be defined only by an assignment to a name (not any other lvalues). Such assignment defines an alias by default. To define a variable, an explicit Type[...] annotation is required. As an exception, at non-global scope non-subscripted rvalue creates a variable even without an annotation. This exception exists to accommodate the common use case of class-valued attributes. See SemanticAnalyzerPass2.check_and_set_up_type_alias for details. Aliases can be generic. Currently, mypy uses unbound type variables for generic aliases and identifies them by name. Essentially, type aliases work as macros that expand textually. The definition and expansion rules are following: 1. An alias targeting a generic class without explicit variables act as the given class (this doesn't apply to Tuple and Callable, which are not proper classes but special type constructors): A = List AA = List[Any] x: A # same as List[Any] x: A[int] # same as List[int] x: AA # same as List[Any] x: AA[int] # Error! C = Callable # Same as Callable[..., Any] T = Tuple # Same as Tuple[Any, ...] 2. An alias using explicit type variables in its rvalue expects replacements (type arguments) for these variables. If missing, they are treated as Any, like for other generics: B = List[Tuple[T, T]] x: B # same as List[Tuple[Any, Any]] x: B[int] # same as List[Tuple[int, int]] def f(x: B[T]) -> T: ... # without T, Any would be used here 3. An alias can be defined using another aliases. In the definition rvalue the Any substitution doesn't happen for top level unsubscripted generic classes: A = List B = A # here A is expanded to List, _not_ List[Any], # to match the Python runtime behaviour x: B[int] # same as List[int] C = List[A] # this expands to List[List[Any]] AA = List[T] D = AA # here AA expands to List[Any] x: D[int] # Error! Note: the fact that we support aliases like `A = List` means that the target type will be initially an instance type with wrong number of type arguments. Such instances are all fixed in the third pass of semantic analyzis. We therefore store the difference between `List` and `List[Any]` rvalues (targets) using the `no_args` flag. See also TypeAliasExpr.no_args. Meaning of other fields: target: The target type. For generic aliases contains unbound type variables as nested types. _fullname: Qualified name of this type alias. This is used in particular to track fine grained dependencies from aliases. alias_tvars: Names of unbound type variables used to define this alias. normalized: Used to distinguish between `A = List`, and `A = list`. Both are internally stored using `builtins.list` (because `typing.List` is itself an alias), while the second cannot be subscripted because of Python runtime limitation. line and column: Line an column on the original alias definition. eager: If True, immediately expand alias when referred to (useful for aliases within functions that can't be looked up from the symbol table) """ __slots__ = ('target', '_fullname', 'alias_tvars', 'no_args', 'normalized', '_is_recursive', 'eager') def __init__(self, target: 'mypy.types.Type', fullname: str, line: int, column: int, *, alias_tvars: Optional[List[str]] = None, no_args: bool = False, normalized: bool = False, eager: bool = False) -> None: self._fullname = fullname self.target = target if alias_tvars is None: alias_tvars = [] self.alias_tvars = alias_tvars self.no_args = no_args self.normalized = normalized # This attribute is manipulated by TypeAliasType. If non-None, # it is the cached value. self._is_recursive: Optional[bool] = None self.eager = eager super().__init__(line, column) @property def name(self) -> str: return self._fullname.split('.')[-1] @property def fullname(self) -> str: return self._fullname def serialize(self) -> JsonDict: data: JsonDict = { ".class": "TypeAlias", "fullname": self._fullname, "target": self.target.serialize(), "alias_tvars": self.alias_tvars, "no_args": self.no_args, "normalized": self.normalized, "line": self.line, "column": self.column, } return data def accept(self, visitor: NodeVisitor[T]) -> T: return visitor.visit_type_alias(self) @classmethod def deserialize(cls, data: JsonDict) -> 'TypeAlias': assert data['.class'] == 'TypeAlias' fullname = data['fullname'] alias_tvars = data['alias_tvars'] target = mypy.types.deserialize_type(data['target']) no_args = data['no_args'] normalized = data['normalized'] line = data['line'] column = data['column'] return cls(target, fullname, line, column, alias_tvars=alias_tvars, no_args=no_args, normalized=normalized) class PlaceholderNode(SymbolNode): """Temporary symbol node that will later become a real SymbolNode. These are only present during semantic analysis when using the new semantic analyzer. These are created if some essential dependencies of a definition are not yet complete. A typical use is for names imported from a module which is still incomplete (within an import cycle): from m import f # Initially may create PlaceholderNode This is particularly important if the imported shadows a name from an enclosing scope or builtins: from m import int # Placeholder avoids mixups with builtins.int Another case where this is useful is when there is another definition or assignment: from m import f def f() -> None: ... In the above example, the presence of PlaceholderNode allows us to handle the second definition as a redefinition. They are also used to create PlaceholderType instances for types that refer to incomplete types. Example: class C(Sequence[C]): ... We create a PlaceholderNode (with becomes_typeinfo=True) for C so that the type C in Sequence[C] can be bound. Attributes: fullname: Full name of of the PlaceholderNode. node: AST node that contains the definition that caused this to be created. This is useful for tracking order of incomplete definitions and for debugging. becomes_typeinfo: If True, this refers something that could later become a TypeInfo. It can't be used with type variables, in particular, as this would cause issues with class type variable detection. The long-term purpose of placeholder nodes/types is to evolve into something that can support general recursive types. """ __slots__ = ('_fullname', 'node', 'becomes_typeinfo') def __init__(self, fullname: str, node: Node, line: int, *, becomes_typeinfo: bool = False) -> None: self._fullname = fullname self.node = node self.becomes_typeinfo = becomes_typeinfo self.line = line @property def name(self) -> str: return self._fullname.split('.')[-1] @property def fullname(self) -> str: return self._fullname def serialize(self) -> JsonDict: assert False, "PlaceholderNode can't be serialized" def accept(self, visitor: NodeVisitor[T]) -> T: return visitor.visit_placeholder_node(self) class SymbolTableNode: """Description of a name binding in a symbol table. These are only used as values in module (global), function (local) and class symbol tables (see SymbolTable). The name that is bound is the key in SymbolTable. Symbol tables don't contain direct references to AST nodes primarily because there can be multiple symbol table references to a single AST node (due to imports and aliases), and different references can behave differently. This class describes the unique properties of each reference. The most fundamental attribute is 'node', which is the AST node that the name refers to. The kind is usually one of LDEF, GDEF or MDEF, depending on the scope of the definition. These three kinds can usually be used interchangeably and the difference between local, global and class scopes is mostly descriptive, with no semantic significance. However, some tools that consume mypy ASTs may care about these so they should be correct. Attributes: node: AST node of definition. Among others, this can be one of FuncDef, Var, TypeInfo, TypeVarExpr or MypyFile -- or None for cross_ref that hasn't been fixed up yet. kind: Kind of node. Possible values: - LDEF: local definition - GDEF: global (module-level) definition - MDEF: class member definition - UNBOUND_IMPORTED: temporary kind for imported names (we don't know the final kind yet) module_public: If False, this name won't be imported via 'from import *'. This has no effect on names within classes. module_hidden: If True, the name will be never exported (needed for stub files) cross_ref: For deserialized MypyFile nodes, the referenced module name; for other nodes, optionally the name of the referenced object. implicit: Was this defined by assignment to self attribute? plugin_generated: Was this symbol generated by a plugin? (And therefore needs to be removed in aststrip.) no_serialize: Do not serialize this node if True. This is used to prevent keys in the cache that refer to modules on which this file does not depend. Currently this can happen if there is a module not in build used e.g. like this: import a.b.c # type: ignore This will add a submodule symbol to parent module `a` symbol table, but `a.b` is _not_ added as its dependency. Therefore, we should not serialize these symbols as they may not be found during fixup phase, instead they will be re-added during subsequent patch parents phase. TODO: Refactor build.py to make dependency tracking more transparent and/or refactor look-up functions to not require parent patching. NOTE: No other attributes should be added to this class unless they are shared by all node kinds. """ __slots__ = ('kind', 'node', 'module_public', 'module_hidden', 'cross_ref', 'implicit', 'plugin_generated', 'no_serialize', ) def __init__(self, kind: int, node: Optional[SymbolNode], module_public: bool = True, implicit: bool = False, module_hidden: bool = False, *, plugin_generated: bool = False, no_serialize: bool = False) -> None: self.kind = kind self.node = node self.module_public = module_public self.implicit = implicit self.module_hidden = module_hidden self.cross_ref: Optional[str] = None self.plugin_generated = plugin_generated self.no_serialize = no_serialize @property def fullname(self) -> Optional[str]: if self.node is not None: return self.node.fullname else: return None @property def type(self) -> 'Optional[mypy.types.Type]': node = self.node if isinstance(node, (Var, SYMBOL_FUNCBASE_TYPES)) and node.type is not None: return node.type elif isinstance(node, Decorator): return node.var.type else: return None def copy(self) -> 'SymbolTableNode': new = SymbolTableNode(self.kind, self.node, self.module_public, self.implicit, self.module_hidden) new.cross_ref = self.cross_ref return new def __str__(self) -> str: s = f'{node_kinds[self.kind]}/{short_type(self.node)}' if isinstance(self.node, SymbolNode): s += f' ({self.node.fullname})' # Include declared type of variables and functions. if self.type is not None: s += f' : {self.type}' return s def serialize(self, prefix: str, name: str) -> JsonDict: """Serialize a SymbolTableNode. Args: prefix: full name of the containing module or class; or None name: name of this object relative to the containing object """ data: JsonDict = { ".class": "SymbolTableNode", "kind": node_kinds[self.kind], } if self.module_hidden: data['module_hidden'] = True if not self.module_public: data['module_public'] = False if self.implicit: data['implicit'] = True if self.plugin_generated: data['plugin_generated'] = True if isinstance(self.node, MypyFile): data['cross_ref'] = self.node.fullname else: assert self.node is not None, f'{prefix}:{name}' if prefix is not None: fullname = self.node.fullname if (fullname is not None and '.' in fullname and fullname != prefix + '.' + name and not (isinstance(self.node, Var) and self.node.from_module_getattr)): assert not isinstance(self.node, PlaceholderNode), ( f'Definition of {fullname} is unexpectedly incomplete' ) data['cross_ref'] = fullname return data data['node'] = self.node.serialize() return data @classmethod def deserialize(cls, data: JsonDict) -> 'SymbolTableNode': assert data['.class'] == 'SymbolTableNode' kind = inverse_node_kinds[data['kind']] if 'cross_ref' in data: # This will be fixed up later. stnode = SymbolTableNode(kind, None) stnode.cross_ref = data['cross_ref'] else: assert 'node' in data, data node = SymbolNode.deserialize(data['node']) stnode = SymbolTableNode(kind, node) if 'module_hidden' in data: stnode.module_hidden = data['module_hidden'] if 'module_public' in data: stnode.module_public = data['module_public'] if 'implicit' in data: stnode.implicit = data['implicit'] if 'plugin_generated' in data: stnode.plugin_generated = data['plugin_generated'] return stnode class SymbolTable(Dict[str, SymbolTableNode]): """Static representation of a namespace dictionary. This is used for module, class and function namespaces. """ __slots__ = () def __str__(self) -> str: a: List[str] = [] for key, value in self.items(): # Filter out the implicit import of builtins. if isinstance(value, SymbolTableNode): if (value.fullname != 'builtins' and (value.fullname or '').split('.')[-1] not in implicit_module_attrs): a.append(' ' + str(key) + ' : ' + str(value)) else: a.append(' ') a = sorted(a) a.insert(0, 'SymbolTable(') a[-1] += ')' return '\n'.join(a) def copy(self) -> 'SymbolTable': return SymbolTable([(key, node.copy()) for key, node in self.items()]) def serialize(self, fullname: str) -> JsonDict: data: JsonDict = {".class": "SymbolTable"} for key, value in self.items(): # Skip __builtins__: it's a reference to the builtins # module that gets added to every module by # SemanticAnalyzerPass2.visit_file(), but it shouldn't be # accessed by users of the module. if key == '__builtins__' or value.no_serialize: continue data[key] = value.serialize(fullname, key) return data @classmethod def deserialize(cls, data: JsonDict) -> 'SymbolTable': assert data['.class'] == 'SymbolTable' st = SymbolTable() for key, value in data.items(): if key != '.class': st[key] = SymbolTableNode.deserialize(value) return st def get_flags(node: Node, names: List[str]) -> List[str]: return [name for name in names if getattr(node, name)] def set_flags(node: Node, flags: List[str]) -> None: for name in flags: setattr(node, name, True) def get_member_expr_fullname(expr: MemberExpr) -> Optional[str]: """Return the qualified name representation of a member expression. Return a string of form foo.bar, foo.bar.baz, or similar, or None if the argument cannot be represented in this form. """ initial: Optional[str] = None if isinstance(expr.expr, NameExpr): initial = expr.expr.name elif isinstance(expr.expr, MemberExpr): initial = get_member_expr_fullname(expr.expr) else: return None return f'{initial}.{expr.name}' deserialize_map: Final = { key: obj.deserialize for key, obj in globals().items() if type(obj) is not FakeInfo and isinstance(obj, type) and issubclass(obj, SymbolNode) and obj is not SymbolNode } def check_arg_kinds( arg_kinds: List[ArgKind], nodes: List[T], fail: Callable[[str, T], None]) -> None: is_var_arg = False is_kw_arg = False seen_named = False seen_opt = False for kind, node in zip(arg_kinds, nodes): if kind == ARG_POS: if is_var_arg or is_kw_arg or seen_named or seen_opt: fail("Required positional args may not appear " "after default, named or var args", node) break elif kind == ARG_OPT: if is_var_arg or is_kw_arg or seen_named: fail("Positional default args may not appear after named or var args", node) break seen_opt = True elif kind == ARG_STAR: if is_var_arg or is_kw_arg or seen_named: fail("Var args may not appear after named or var args", node) break is_var_arg = True elif kind == ARG_NAMED or kind == ARG_NAMED_OPT: seen_named = True if is_kw_arg: fail("A **kwargs argument must be the last argument", node) break elif kind == ARG_STAR2: if is_kw_arg: fail("You may only have one **kwargs argument", node) break is_kw_arg = True def check_arg_names(names: Sequence[Optional[str]], nodes: List[T], fail: Callable[[str, T], None], description: str = 'function definition') -> None: seen_names: Set[Optional[str]] = set() for name, node in zip(names, nodes): if name is not None and name in seen_names: fail(f'Duplicate argument "{name}" in {description}', node) break seen_names.add(name) def is_class_var(expr: NameExpr) -> bool: """Return whether the expression is ClassVar[...]""" if isinstance(expr.node, Var): return expr.node.is_classvar return False def is_final_node(node: Optional[SymbolNode]) -> bool: """Check whether `node` corresponds to a final attribute.""" return isinstance(node, (Var, FuncDef, OverloadedFuncDef, Decorator)) and node.is_final def local_definitions(names: SymbolTable, name_prefix: str, info: Optional[TypeInfo] = None) -> Iterator[Definition]: """Iterate over local definitions (not imported) in a symbol table. Recursively iterate over class members and nested classes. """ # TODO: What should the name be? Or maybe remove it? for name, symnode in names.items(): shortname = name if '-redef' in name: # Restore original name from mangled name of multiply defined function shortname = name.split('-redef')[0] fullname = name_prefix + '.' + shortname node = symnode.node if node and node.fullname == fullname: yield fullname, symnode, info if isinstance(node, TypeInfo): yield from local_definitions(node.names, fullname, node)