def analyze_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, builtin_type: Callable[[str], Instance], msg: MessageBuilder) -> Type: node = itype.type.get(name) if not node: return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype.type, is_classmethod, builtin_type) if isinstance(node.node, TypeInfo): return type_object_type(cast(TypeInfo, node.node), builtin_type) return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))
def analyse_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, msg: MessageBuilder) -> Type: node = itype.type.get(name) if not node: return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) t = node.type if t: is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype.type, is_classmethod) if isinstance(node.node, TypeInfo): # TODO add second argument return type_object_type(cast(TypeInfo, node.node), None) return function_type(cast(FuncBase, node.node))
def analyse_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, msg: MessageBuilder) -> Type: node = itype.type.get(name) if not node: return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) t = node.type if t: is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype.type, is_classmethod) if isinstance(node.node, TypeInfo): # TODO add second argument return type_object_type(cast(TypeInfo, node.node), None) return function_type(cast(FuncBase, node.node))
def analyze_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, builtin_type: Callable[[str], Instance], msg: MessageBuilder) -> Type: node = itype.type.get(name) if not node: return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype.type, is_classmethod, builtin_type) if isinstance(node.node, TypeInfo): return type_object_type(cast(TypeInfo, node.node), builtin_type) return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))
def find_non_escaped_targets( format_value: str, ctx: Context, msg: MessageBuilder) -> Optional[List[Tuple[str, int]]]: """Return list of raw (un-parsed) format specifiers in format string. Format specifiers don't include enclosing braces. We don't use regexp for this because they don't work well with nested/repeated patterns (both greedy and non-greedy), and these are heavily used internally for representation of f-strings. Return None in case of an error. """ result = [] next_spec = '' pos = 0 nesting = 0 while pos < len(format_value): c = format_value[pos] if not nesting: # Skip any paired '{{' and '}}', enter nesting on '{', report error on '}'. if c == '{': if pos < len(format_value) - 1 and format_value[pos + 1] == '{': pos += 1 else: nesting = 1 if c == '}': if pos < len(format_value) - 1 and format_value[pos + 1] == '}': pos += 1 else: msg.fail( 'Invalid conversion specifier in format string:' ' unexpected }', ctx, code=codes.STRING_FORMATTING) return None else: # Adjust nesting level, then either continue adding chars or move on. if c == '{': nesting += 1 if c == '}': nesting -= 1 if nesting: next_spec += c else: result.append((next_spec, pos - len(next_spec))) next_spec = '' pos += 1 if nesting: msg.fail( 'Invalid conversion specifier in format string:' ' unmatched {', ctx, code=codes.STRING_FORMATTING) return None return result
def analyze_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, original_type: Type) -> Type: """original_type is the type of E in the expression E.var""" node = itype.type.get(name) if not node: if itype.type.fallback_to_any: return AnyType() return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: if isinstance(t, PartialType): return handle_partial_attribute_type(t, is_lvalue, msg, node.node) if not is_method and (isinstance(t, TypeVarType) or get_type_vars(t)): msg.fail(messages.GENERIC_INSTANCE_VAR_CLASS_ACCESS, context) is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype, is_classmethod, builtin_type, original_type) elif isinstance(node.node, Var): not_ready_callback(name, context) return AnyType() if isinstance(node.node, TypeVarExpr): return TypeVarType(node.tvar_def, node.tvar_def.line, node.tvar_def.column) if isinstance(node.node, TypeInfo): return type_object_type(node.node, builtin_type) if isinstance(node.node, MypyFile): # Reference to a module object. return builtin_type('builtins.module') if is_decorated: # TODO: Return type of decorated function. This is quick hack to work around #998. return AnyType() else: return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))
def handle_partial_attribute_type(typ: PartialType, is_lvalue: bool, msg: MessageBuilder, context: Context) -> Type: if typ.type is None: # 'None' partial type. It has a well-defined type -- 'None'. # In an lvalue context we want to preserver the knowledge of # it being a partial type. if not is_lvalue: return NoneTyp() return typ else: msg.fail(messages.NEED_ANNOTATION_FOR_VAR, context) return AnyType()
def handle_partial_attribute_type(typ: PartialType, is_lvalue: bool, msg: MessageBuilder, context: Context) -> Type: if typ.type is None: # 'None' partial type. It has a well-defined type -- 'None'. # In an lvalue context we want to preserver the knowledge of # it being a partial type. if not is_lvalue: return NoneTyp() return typ else: msg.fail(messages.NEED_ANNOTATION_FOR_VAR, context) return AnyType()
def analyze_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, original_type: Type) -> Type: """original_type is the type of E in the expression E.var""" node = itype.type.get(name) if not node: if itype.type.fallback_to_any: return AnyType() return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: if isinstance(t, PartialType): return handle_partial_attribute_type(t, is_lvalue, msg, node.node) is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype, is_classmethod, builtin_type, original_type) elif isinstance(node.node, Var): not_ready_callback(name, context) return AnyType() if isinstance(node.node, TypeVarExpr): return TypeVarType(node.tvar_def, node.tvar_def.line, node.tvar_def.column) if isinstance(node.node, TypeInfo): return type_object_type(node.node, builtin_type) if isinstance(node.node, MypyFile): # Reference to a module object. return builtin_type('builtins.module') if is_decorated: # TODO: Return type of decorated function. This is quick hack to work around #998. return AnyType() else: return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))
def analyze_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, check_untyped_defs: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder) -> Type: node = itype.type.get(name) if not node: if itype.type.fallback_to_any: return AnyType() return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: if isinstance(t, PartialType): return handle_partial_attribute_type(t, is_lvalue, msg, node.node) is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype.type, is_classmethod, builtin_type) elif isinstance(node.node, Var): not_ready_callback(name, context) return AnyType() if isinstance(node.node, TypeInfo): return type_object_type(check_untyped_defs, node.node, builtin_type) if is_decorated: # TODO: Return type of decorated function. This is quick hack to work around #998. return AnyType() else: return function_type(check_untyped_defs, cast(FuncBase, node.node), builtin_type('builtins.function'))
def analyse_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, msg: MessageBuilder) -> Type: node = itype.type.get(name) if node: if is_lvalue and isinstance(node.node, FuncDef): msg.fail(messages.CANNOT_ASSIGN_TO_METHOD, context) if is_lvalue and isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) t = node.type if t: return add_class_tvars(t, itype.type) elif isinstance(node.node, TypeInfo): # TODO add second argument return type_object_type(cast(TypeInfo, node.node), None) else: return function_type(cast(FuncBase, node.node)) else: return None
def analyse_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, msg: MessageBuilder) -> Type: node = itype.type.get(name) if node: if is_lvalue and isinstance(node.node, FuncDef): msg.fail(messages.CANNOT_ASSIGN_TO_METHOD, context) if is_lvalue and isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) t = node.type if t: return add_class_tvars(t, itype.type) elif isinstance(node.node, TypeInfo): # TODO add second argument return type_object_type(cast(TypeInfo, node.node), None) else: return function_type(cast(FuncBase, node.node)) else: return None
def analyze_class_attribute_access( itype: Instance, name: str, context: Context, is_lvalue: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, ) -> Type: node = itype.type.get(name) if not node: if itype.type.fallback_to_any: return AnyType() return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype.type, is_classmethod, builtin_type) elif isinstance(node.node, Var): not_ready_callback(name, context) return AnyType() if isinstance(node.node, TypeInfo): return type_object_type(cast(TypeInfo, node.node), builtin_type) if is_decorated: # TODO: Return type of decorated function. This is quick hack to work around #998. return AnyType() else: return function_type(cast(FuncBase, node.node), builtin_type("builtins.function"))
def analyze_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, original_type: Type) -> Optional[Type]: """original_type is the type of E in the expression E.var""" node = itype.type.get(name) if not node: if itype.type.fallback_to_any: return AnyType(TypeOfAny.special_form) return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncDef) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: if isinstance(t, PartialType): symnode = node.node assert symnode is not None return handle_partial_attribute_type(t, is_lvalue, msg, symnode) if not is_method and (isinstance(t, TypeVarType) or get_type_vars(t)): msg.fail(messages.GENERIC_INSTANCE_VAR_CLASS_ACCESS, context) is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class return add_class_tvars(t, itype, is_classmethod, builtin_type, original_type) elif isinstance(node.node, Var): not_ready_callback(name, context) return AnyType(TypeOfAny.special_form) if isinstance(node.node, TypeVarExpr): msg.fail('Type variable "{}.{}" cannot be used as an expression'.format( itype.type.name(), name), context) return AnyType(TypeOfAny.from_error) if isinstance(node.node, TypeInfo): return type_object_type(node.node, builtin_type) if isinstance(node.node, MypyFile): # Reference to a module object. return builtin_type('types.ModuleType') if is_decorated: # TODO: Return type of decorated function. This is quick hack to work around #998. return AnyType(TypeOfAny.special_form) else: return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))
def parse_format_value( format_value: str, ctx: Context, msg: MessageBuilder, nested: bool = False) -> Optional[List[ConversionSpecifier]]: """Parse format string into list of conversion specifiers. The specifiers may be nested (two levels maximum), in this case they are ordered as '{0:{1}}, {2:{3}{4}}'. Return None in case of an error. """ top_targets = find_non_escaped_targets(format_value, ctx, msg) if top_targets is None: return None result: List[ConversionSpecifier] = [] for target, start_pos in top_targets: match = FORMAT_RE_NEW.fullmatch(target) if match: conv_spec = ConversionSpecifier(match, start_pos=start_pos) else: custom_match = FORMAT_RE_NEW_CUSTOM.fullmatch(target) if custom_match: conv_spec = ConversionSpecifier(custom_match, start_pos=start_pos, non_standard_format_spec=True) else: msg.fail('Invalid conversion specifier in format string', ctx, code=codes.STRING_FORMATTING) return None if conv_spec.key and ('{' in conv_spec.key or '}' in conv_spec.key): msg.fail('Conversion value must not contain { or }', ctx, code=codes.STRING_FORMATTING) return None result.append(conv_spec) # Parse nested conversions that are allowed in format specifier. if (conv_spec.format_spec and conv_spec.non_standard_format_spec and ('{' in conv_spec.format_spec or '}' in conv_spec.format_spec)): if nested: msg.fail('Formatting nesting must be at most two levels deep', ctx, code=codes.STRING_FORMATTING) return None sub_conv_specs = parse_format_value(conv_spec.format_spec, ctx, msg, nested=True) if sub_conv_specs is None: return None result.extend(sub_conv_specs) return result
def analyze_member_access(name: str, typ: Type, node: Context, is_lvalue: bool, is_super: bool, builtin_type: Callable[[str], Instance], msg: MessageBuilder, override_info: TypeInfo = None, report_type: Type = None) -> Type: """Analyse attribute access. This is a general operation that supports various different variations: 1. lvalue or non-lvalue access (i.e. setter or getter access) 2. supertype access (when using super(); is_super == True and override_info should refer to the supertype) """ report_type = report_type or typ if isinstance(typ, Instance): if name == '__init__' and not is_super: # Accessing __init__ in statically typed code would compromise # type safety unless used via super(). msg.fail(messages.CANNOT_ACCESS_INIT, node) return AnyType() # The base object has an instance type. info = typ.type if override_info: info = override_info # Look up the member. First look up the method dictionary. method = info.get_method(name) if method: if method.is_property: assert isinstance(method, OverloadedFuncDef) method = cast(OverloadedFuncDef, method) return analyze_var(name, method.items[0].var, typ, info, node, is_lvalue, msg) if is_lvalue: msg.cant_assign_to_method(node) typ = map_instance_to_supertype(typ, method.info) return expand_type_by_instance( method_type_with_fallback(method, builtin_type('builtins.function')), typ) else: # Not a method. return analyze_member_var_access(name, typ, info, node, is_lvalue, is_super, builtin_type, msg, report_type=report_type) elif isinstance(typ, AnyType): # The base object has dynamic type. return AnyType() elif isinstance(typ, UnionType): # The base object has dynamic type. msg.disable_type_names += 1 results = [ analyze_member_access(name, subtype, node, is_lvalue, is_super, builtin_type, msg) for subtype in typ.items ] msg.disable_type_names -= 1 return UnionType.make_simplified_union(results) elif isinstance(typ, TupleType): # Actually look up from the fallback instance type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, builtin_type, msg) elif isinstance(typ, FunctionLike) and typ.is_type_obj(): # Class attribute. # TODO super? itype = cast(Instance, typ.items()[0].ret_type) result = analyze_class_attribute_access(itype, name, node, is_lvalue, builtin_type, msg) if result: return result # Look up from the 'type' type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, builtin_type, msg, report_type=report_type) elif isinstance(typ, FunctionLike): # Look up from the 'function' type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, builtin_type, msg, report_type=report_type) elif isinstance(typ, TypeVarType): return analyze_member_access(name, typ.upper_bound, node, is_lvalue, is_super, builtin_type, msg, report_type=report_type) return msg.has_no_attr(report_type, name, node)
def analyze_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, original_type: Type, chk: 'mypy.checker.TypeChecker') -> Optional[Type]: """original_type is the type of E in the expression E.var""" node = itype.type.get(name) if not node: if itype.type.fallback_to_any: return AnyType(TypeOfAny.special_form) return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncBase) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) # If a final attribute was declared on `self` in `__init__`, then it # can't be accessed on the class object. if node.implicit and isinstance(node.node, Var) and node.node.is_final: msg.fail('Cannot access final instance ' 'attribute "{}" on class object'.format(node.node.name()), context) # An assignment to final attribute on class object is also always an error, # independently of types. if is_lvalue and not chk.get_final_context(): check_final_member(name, itype.type, msg, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: if isinstance(t, PartialType): symnode = node.node assert isinstance(symnode, Var) return chk.handle_partial_var_type(t, is_lvalue, symnode, context) if not is_method and (isinstance(t, TypeVarType) or get_type_vars(t)): msg.fail(messages.GENERIC_INSTANCE_VAR_CLASS_ACCESS, context) is_classmethod = ((is_decorated and cast(Decorator, node.node).func.is_class) or (isinstance(node.node, FuncBase) and node.node.is_class)) result = add_class_tvars(t, itype, is_classmethod, builtin_type, original_type) if not is_lvalue: result = analyze_descriptor_access(original_type, result, builtin_type, msg, context, chk=chk) return result elif isinstance(node.node, Var): not_ready_callback(name, context) return AnyType(TypeOfAny.special_form) if isinstance(node.node, TypeVarExpr): msg.fail('Type variable "{}.{}" cannot be used as an expression'.format( itype.type.name(), name), context) return AnyType(TypeOfAny.from_error) if isinstance(node.node, TypeInfo): return type_object_type(node.node, builtin_type) if isinstance(node.node, MypyFile): # Reference to a module object. return builtin_type('types.ModuleType') if isinstance(node.node, TypeAlias) and isinstance(node.node.target, Instance): return instance_alias_type(node.node, builtin_type) if is_decorated: assert isinstance(node.node, Decorator) if node.node.type: return node.node.type else: not_ready_callback(name, context) return AnyType(TypeOfAny.from_error) else: return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))
def analyze_class_attribute_access(itype: Instance, name: str, context: Context, is_lvalue: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, original_type: Type) -> Optional[Type]: """original_type is the type of E in the expression E.var""" node = itype.type.get(name) if not node: if itype.type.fallback_to_any: return AnyType(TypeOfAny.special_form) return None is_decorated = isinstance(node.node, Decorator) is_method = is_decorated or isinstance(node.node, FuncBase) if is_lvalue: if is_method: msg.cant_assign_to_method(context) if isinstance(node.node, TypeInfo): msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context) if itype.type.is_enum and not (is_lvalue or is_decorated or is_method): return itype t = node.type if t: if isinstance(t, PartialType): symnode = node.node assert symnode is not None return handle_partial_attribute_type(t, is_lvalue, msg, symnode) if not is_method and (isinstance(t, TypeVarType) or get_type_vars(t)): msg.fail(messages.GENERIC_INSTANCE_VAR_CLASS_ACCESS, context) is_classmethod = ( (is_decorated and cast(Decorator, node.node).func.is_class) or (isinstance(node.node, FuncBase) and node.node.is_class)) return add_class_tvars(t, itype, is_classmethod, builtin_type, original_type) elif isinstance(node.node, Var): not_ready_callback(name, context) return AnyType(TypeOfAny.special_form) if isinstance(node.node, TypeVarExpr): msg.fail( 'Type variable "{}.{}" cannot be used as an expression'.format( itype.type.name(), name), context) return AnyType(TypeOfAny.from_error) if isinstance(node.node, TypeInfo): return type_object_type(node.node, builtin_type) if isinstance(node.node, MypyFile): # Reference to a module object. return builtin_type('types.ModuleType') if isinstance(node.node, TypeAlias) and isinstance(node.node.target, Instance): return instance_alias_type(node.node, builtin_type) if is_decorated: assert isinstance(node.node, Decorator) if node.node.type: return node.node.type else: not_ready_callback(name, context) return AnyType(TypeOfAny.from_error) else: return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))
def analyze_descriptor_access(instance_type: Type, descriptor_type: Type, builtin_type: Callable[[str], Instance], msg: MessageBuilder, context: Context, *, chk: 'mypy.checker.TypeChecker') -> Type: """Type check descriptor access. Arguments: instance_type: The type of the instance on which the descriptor attribute is being accessed (the type of ``a`` in ``a.f`` when ``f`` is a descriptor). descriptor_type: The type of the descriptor attribute being accessed (the type of ``f`` in ``a.f`` when ``f`` is a descriptor). context: The node defining the context of this inference. Return: The return type of the appropriate ``__get__`` overload for the descriptor. """ if isinstance(descriptor_type, UnionType): # Map the access over union types return UnionType.make_simplified_union([ analyze_descriptor_access(instance_type, typ, builtin_type, msg, context, chk=chk) for typ in descriptor_type.items ]) elif not isinstance(descriptor_type, Instance): return descriptor_type if not descriptor_type.type.has_readable_member('__get__'): return descriptor_type dunder_get = descriptor_type.type.get_method('__get__') if dunder_get is None: msg.fail(message_registry.DESCRIPTOR_GET_NOT_CALLABLE.format(descriptor_type), context) return AnyType(TypeOfAny.from_error) function = function_type(dunder_get, builtin_type('builtins.function')) bound_method = bind_self(function, descriptor_type) typ = map_instance_to_supertype(descriptor_type, dunder_get.info) dunder_get_type = expand_type_by_instance(bound_method, typ) if isinstance(instance_type, FunctionLike) and instance_type.is_type_obj(): owner_type = instance_type.items()[0].ret_type instance_type = NoneTyp() elif isinstance(instance_type, TypeType): owner_type = instance_type.item instance_type = NoneTyp() else: owner_type = instance_type _, inferred_dunder_get_type = chk.expr_checker.check_call( dunder_get_type, [TempNode(instance_type), TempNode(TypeType.make_normalized(owner_type))], [ARG_POS, ARG_POS], context) if isinstance(inferred_dunder_get_type, AnyType): # check_call failed, and will have reported an error return inferred_dunder_get_type if not isinstance(inferred_dunder_get_type, CallableType): msg.fail(message_registry.DESCRIPTOR_GET_NOT_CALLABLE.format(descriptor_type), context) return AnyType(TypeOfAny.from_error) return inferred_dunder_get_type.ret_type
def analyze_member_access(name: str, typ: Type, node: Context, is_lvalue: bool, is_super: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, override_info: TypeInfo = None, report_type: Type = None) -> Type: """Analyse attribute access. This is a general operation that supports various different variations: 1. lvalue or non-lvalue access (i.e. setter or getter access) 2. supertype access (when using super(); is_super == True and override_info should refer to the supertype) """ report_type = report_type or typ if isinstance(typ, Instance): if name == '__init__' and not is_super: # Accessing __init__ in statically typed code would compromise # type safety unless used via super(). msg.fail(messages.CANNOT_ACCESS_INIT, node) return AnyType() # The base object has an instance type. info = typ.type if override_info: info = override_info # Look up the member. First look up the method dictionary. method = info.get_method(name) if method: if method.is_property: assert isinstance(method, OverloadedFuncDef) method = cast(OverloadedFuncDef, method) return analyze_var(name, method.items[0].var, typ, info, node, is_lvalue, msg, not_ready_callback) if is_lvalue: msg.cant_assign_to_method(node) typ = map_instance_to_supertype(typ, method.info) if name == '__new__': # __new__ is special and behaves like a static method -- don't strip # the first argument. signature = function_type(method, builtin_type('builtins.function')) else: signature = method_type_with_fallback(method, builtin_type('builtins.function')) return expand_type_by_instance(signature, typ) else: # Not a method. return analyze_member_var_access(name, typ, info, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg, report_type=report_type) elif isinstance(typ, AnyType): # The base object has dynamic type. return AnyType() elif isinstance(typ, UnionType): # The base object has dynamic type. msg.disable_type_names += 1 results = [analyze_member_access(name, subtype, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg) for subtype in typ.items] msg.disable_type_names -= 1 return UnionType.make_simplified_union(results) elif isinstance(typ, TupleType): # Actually look up from the fallback instance type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg) elif isinstance(typ, FunctionLike) and typ.is_type_obj(): # Class attribute. # TODO super? ret_type = typ.items()[0].ret_type if isinstance(ret_type, TupleType): ret_type = ret_type.fallback if isinstance(ret_type, Instance): result = analyze_class_attribute_access(ret_type, name, node, is_lvalue, builtin_type, not_ready_callback, msg) if result: return result # Look up from the 'type' type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg, report_type=report_type) else: assert False, 'Unexpected type {}'.format(repr(ret_type)) elif isinstance(typ, FunctionLike): # Look up from the 'function' type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg, report_type=report_type) elif isinstance(typ, TypeVarType): return analyze_member_access(name, typ.upper_bound, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg, report_type=report_type) elif isinstance(typ, DeletedType): msg.deleted_as_rvalue(typ, node) return AnyType() return msg.has_no_attr(report_type, name, node)
def analyse_member_access(name: str, typ: Type, node: Context, is_lvalue: bool, is_super: bool, builtin_type: Function[[str], Instance], msg: MessageBuilder, override_info: TypeInfo = None, report_type: Type = None) -> Type: """Analyse attribute access. This is a general operation that supports various different variations: 1. lvalue or non-lvalue access (i.e. setter or getter access) 2. supertype access (when using super(); is_super == True and override_info should refer to the supertype) """ report_type = report_type or typ if isinstance(typ, Instance): if name == '__init__' and not is_super: # Accessing __init__ in statically typed code would compromise # type safety unless used via super(). msg.fail(messages.CANNOT_ACCESS_INIT, node) return AnyType() # The base object has an instance type. info = typ.type if override_info: info = override_info # Look up the member. First look up the method dictionary. method = info.get_method(name) if method: if is_lvalue: msg.cant_assign_to_method(node) typ = map_instance_to_supertype(typ, method.info) return expand_type_by_instance( method_type(method, builtin_type('builtins.function')), typ) else: # Not a method. return analyse_member_var_access(name, typ, info, node, is_lvalue, is_super, msg, report_type=report_type) elif isinstance(typ, AnyType): # The base object has dynamic type. return AnyType() elif isinstance(typ, UnionType): # The base object has dynamic type. msg.disable_type_names += 1 results = [analyse_member_access(name, subtype, node, is_lvalue, is_super, builtin_type, msg) for subtype in typ.items] msg.disable_type_names -= 1 return UnionType.make_simplified_union(results) elif isinstance(typ, TupleType): # Actually look up from the fallback instance type. return analyse_member_access(name, typ.fallback, node, is_lvalue, is_super, builtin_type, msg) elif (isinstance(typ, FunctionLike) and cast(FunctionLike, typ).is_type_obj()): # Class attribute. # TODO super? sig = cast(FunctionLike, typ) itype = cast(Instance, sig.items()[0].ret_type) result = analyse_class_attribute_access(itype, name, node, is_lvalue, builtin_type, msg) if result: return result # Look up from the 'type' type. return analyse_member_access(name, sig.fallback, node, is_lvalue, is_super, builtin_type, msg, report_type=report_type) elif isinstance(typ, FunctionLike): # Look up from the 'function' type. return analyse_member_access(name, typ.fallback, node, is_lvalue, is_super, builtin_type, msg, report_type=report_type) return msg.has_no_attr(report_type, name, node)
def analyze_member_access(name: str, typ: Type, node: Context, is_lvalue: bool, is_super: bool, is_operator: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, *, original_type: Type, override_info: TypeInfo = None, chk: 'mypy.checker.TypeChecker' = None) -> Type: """Return the type of attribute `name` of typ. This is a general operation that supports various different variations: 1. lvalue or non-lvalue access (i.e. setter or getter access) 2. supertype access (when using super(); is_super == True and override_info should refer to the supertype) original_type is the most precise inferred or declared type of the base object that we have available. typ is generally a supertype of original_type. When looking for an attribute of typ, we may perform recursive calls targeting the fallback type, for example. original_type is always the type used in the initial call. """ if isinstance(typ, Instance): if name == '__init__' and not is_super: # Accessing __init__ in statically typed code would compromise # type safety unless used via super(). msg.fail(messages.CANNOT_ACCESS_INIT, node) return AnyType() # The base object has an instance type. info = typ.type if override_info: info = override_info if (experiments.find_occurrences and info.name() == experiments.find_occurrences[0] and name == experiments.find_occurrences[1]): msg.note( "Occurrence of '{}.{}'".format(*experiments.find_occurrences), node) # Look up the member. First look up the method dictionary. method = info.get_method(name) if method: if method.is_property: assert isinstance(method, OverloadedFuncDef) return analyze_var(name, method.items[0].var, typ, info, node, is_lvalue, msg, original_type, not_ready_callback) if is_lvalue: msg.cant_assign_to_method(node) signature = function_type(method, builtin_type('builtins.function')) signature = freshen_function_type_vars(signature) if name == '__new__': # __new__ is special and behaves like a static method -- don't strip # the first argument. pass else: signature = bind_self(signature, original_type) typ = map_instance_to_supertype(typ, method.info) member_type = expand_type_by_instance(signature, typ) freeze_type_vars(member_type) return member_type else: # Not a method. return analyze_member_var_access(name, typ, info, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, AnyType): # The base object has dynamic type. return AnyType() elif isinstance(typ, NoneTyp): if chk and chk.should_suppress_optional_error([typ]): return AnyType() # The only attribute NoneType has are those it inherits from object return analyze_member_access(name, builtin_type('builtins.object'), node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, UnionType): # The base object has dynamic type. msg.disable_type_names += 1 results = [ analyze_member_access(name, subtype, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) for subtype in typ.items ] msg.disable_type_names -= 1 return UnionType.make_simplified_union(results) elif isinstance(typ, TupleType): # Actually look up from the fallback instance type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, TypedDictType): # Actually look up from the fallback instance type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, FunctionLike) and typ.is_type_obj(): # Class attribute. # TODO super? ret_type = typ.items()[0].ret_type if isinstance(ret_type, TupleType): ret_type = ret_type.fallback if isinstance(ret_type, Instance): if not is_operator: # When Python sees an operator (eg `3 == 4`), it automatically translates that # into something like `int.__eq__(3, 4)` instead of `(3).__eq__(4)` as an # optimization. # # While it normally it doesn't matter which of the two versions are used, it # does cause inconsistencies when working with classes. For example, translating # `int == int` to `int.__eq__(int)` would not work since `int.__eq__` is meant to # compare two int _instances_. What we really want is `type(int).__eq__`, which # is meant to compare two types or classes. # # This check makes sure that when we encounter an operator, we skip looking up # the corresponding method in the current instance to avoid this edge case. # See https://github.com/python/mypy/pull/1787 for more info. result = analyze_class_attribute_access( ret_type, name, node, is_lvalue, builtin_type, not_ready_callback, msg, original_type=original_type) if result: return result # Look up from the 'type' type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) else: assert False, 'Unexpected type {}'.format(repr(ret_type)) elif isinstance(typ, FunctionLike): # Look up from the 'function' type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, TypeVarType): return analyze_member_access(name, typ.upper_bound, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, DeletedType): msg.deleted_as_rvalue(typ, node) return AnyType() elif isinstance(typ, TypeType): # Similar to FunctionLike + is_type_obj() above. item = None if isinstance(typ.item, Instance): item = typ.item elif isinstance(typ.item, TypeVarType): if isinstance(typ.item.upper_bound, Instance): item = typ.item.upper_bound if item and not is_operator: # See comment above for why operators are skipped result = analyze_class_attribute_access( item, name, node, is_lvalue, builtin_type, not_ready_callback, msg, original_type=original_type) if result: return result fallback = builtin_type('builtins.type') if item is not None: fallback = item.type.metaclass_type or fallback return analyze_member_access(name, fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) if chk and chk.should_suppress_optional_error([typ]): return AnyType() return msg.has_no_attr(original_type, name, node)
def analyse_member_access(name: str, typ: Type, node: Context, is_lvalue: bool, is_super: bool, basic_types: BasicTypes, msg: MessageBuilder, override_info: TypeInfo = None, report_type: Type = None) -> Type: """Analyse attribute access. This is a general operation that supports various different variations: 1. lvalue or non-lvalue access (i.e. setter or getter access) 2. supertype access (when using super(); is_super == True and override_info should refer to the supertype) """ report_type = report_type or typ if isinstance(typ, Instance): if name == '__init__' and not is_super: # Accessing __init__ in statically typed code would compromise # type safety unless used via super(). msg.fail(messages.CANNOT_ACCESS_INIT, node) return AnyType() # The base object has an instance type. info = typ.type if override_info: info = override_info # Look up the member. First look up the method dictionary. method = info.get_method(name) if method: if is_lvalue: msg.fail(messages.CANNOT_ASSIGN_TO_METHOD, node) typ = map_instance_to_supertype(typ, method.info) return expand_type_by_instance(method_type(method), typ) else: # Not a method. return analyse_member_var_access(name, typ, info, node, is_lvalue, is_super, msg, report_type=report_type) elif isinstance(typ, AnyType): # The base object has dynamic type. return AnyType() elif isinstance(typ, TupleType): # Actually look up from the 'tuple' type. return analyse_member_access(name, basic_types.tuple, node, is_lvalue, is_super, basic_types, msg) elif (isinstance(typ, FunctionLike) and cast(FunctionLike, typ).is_type_obj()): # Class attribute. # TODO super? sig = cast(FunctionLike, typ) itype = cast(Instance, sig.items()[0].ret_type) result = analyse_class_attribute_access(itype, name, node, is_lvalue, msg) if result: return result # Look up from the 'type' type. return analyse_member_access(name, basic_types.type_type, node, is_lvalue, is_super, basic_types, msg, report_type=report_type) elif isinstance(typ, FunctionLike): # Look up from the 'function' type. return analyse_member_access(name, basic_types.function, node, is_lvalue, is_super, basic_types, msg, report_type=report_type) return msg.has_no_attr(report_type, name, node)
def analyze_member_access( name: str, typ: Type, node: Context, is_lvalue: bool, is_super: bool, is_operator: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, override_info: TypeInfo = None, report_type: Type = None, chk: "mypy.checker.TypeChecker" = None, ) -> Type: """Analyse attribute access. This is a general operation that supports various different variations: 1. lvalue or non-lvalue access (i.e. setter or getter access) 2. supertype access (when using super(); is_super == True and override_info should refer to the supertype) """ report_type = report_type or typ if isinstance(typ, Instance): if name == "__init__" and not is_super: # Accessing __init__ in statically typed code would compromise # type safety unless used via super(). msg.fail(messages.CANNOT_ACCESS_INIT, node) return AnyType() # The base object has an instance type. info = typ.type if override_info: info = override_info # Look up the member. First look up the method dictionary. method = info.get_method(name) if method: if method.is_property: assert isinstance(method, OverloadedFuncDef) return analyze_var(name, method.items[0].var, typ, info, node, is_lvalue, msg, not_ready_callback) if is_lvalue: msg.cant_assign_to_method(node) typ = map_instance_to_supertype(typ, method.info) if name == "__new__": # __new__ is special and behaves like a static method -- don't strip # the first argument. signature = function_type(method, builtin_type("builtins.function")) else: signature = method_type_with_fallback(method, builtin_type("builtins.function")) return expand_type_by_instance(signature, typ) else: # Not a method. return analyze_member_var_access( name, typ, info, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg, report_type=report_type, chk=chk, ) elif isinstance(typ, AnyType): # The base object has dynamic type. return AnyType() elif isinstance(typ, NoneTyp): if chk and chk.should_suppress_optional_error([typ]): return AnyType() # The only attribute NoneType has are those it inherits from object return analyze_member_access( name, builtin_type("builtins.object"), node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, report_type=report_type, chk=chk, ) elif isinstance(typ, UnionType): # The base object has dynamic type. msg.disable_type_names += 1 results = [ analyze_member_access( name, subtype, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, chk=chk ) for subtype in typ.items ] msg.disable_type_names -= 1 return UnionType.make_simplified_union(results) elif isinstance(typ, TupleType): # Actually look up from the fallback instance type. return analyze_member_access( name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, chk=chk ) elif isinstance(typ, FunctionLike) and typ.is_type_obj(): # Class attribute. # TODO super? ret_type = typ.items()[0].ret_type if isinstance(ret_type, TupleType): ret_type = ret_type.fallback if isinstance(ret_type, Instance): if not is_operator: # When Python sees an operator (eg `3 == 4`), it automatically translates that # into something like `int.__eq__(3, 4)` instead of `(3).__eq__(4)` as an # optimation. # # While it normally it doesn't matter which of the two versions are used, it # does cause inconsistencies when working with classes. For example, translating # `int == int` to `int.__eq__(int)` would not work since `int.__eq__` is meant to # compare two int _instances_. What we really want is `type(int).__eq__`, which # is meant to compare two types or classes. # # This check makes sure that when we encounter an operator, we skip looking up # the corresponding method in the current instance to avoid this edge case. # See https://github.com/python/mypy/pull/1787 for more info. result = analyze_class_attribute_access( ret_type, name, node, is_lvalue, builtin_type, not_ready_callback, msg ) if result: return result # Look up from the 'type' type. return analyze_member_access( name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, report_type=report_type, chk=chk, ) else: assert False, "Unexpected type {}".format(repr(ret_type)) elif isinstance(typ, FunctionLike): # Look up from the 'function' type. return analyze_member_access( name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, report_type=report_type, chk=chk, ) elif isinstance(typ, TypeVarType): return analyze_member_access( name, typ.upper_bound, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, report_type=report_type, chk=chk, ) elif isinstance(typ, DeletedType): msg.deleted_as_rvalue(typ, node) return AnyType() elif isinstance(typ, TypeType): # Similar to FunctionLike + is_type_obj() above. item = None if isinstance(typ.item, Instance): item = typ.item elif isinstance(typ.item, TypeVarType): if isinstance(typ.item.upper_bound, Instance): item = typ.item.upper_bound if item and not is_operator: # See comment above for why operators are skipped result = analyze_class_attribute_access(item, name, node, is_lvalue, builtin_type, not_ready_callback, msg) if result: return result fallback = builtin_type("builtins.type") return analyze_member_access( name, fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, report_type=report_type, chk=chk, ) if chk and chk.should_suppress_optional_error([typ]): return AnyType() return msg.has_no_attr(report_type, name, node)
def analyze_member_access(name: str, typ: Type, node: Context, is_lvalue: bool, is_super: bool, is_operator: bool, builtin_type: Callable[[str], Instance], not_ready_callback: Callable[[str, Context], None], msg: MessageBuilder, *, original_type: Type, chk: 'mypy.checker.TypeChecker', override_info: Optional[TypeInfo] = None) -> Type: """Return the type of attribute `name` of typ. This is a general operation that supports various different variations: 1. lvalue or non-lvalue access (i.e. setter or getter access) 2. supertype access (when using super(); is_super == True and override_info should refer to the supertype) original_type is the most precise inferred or declared type of the base object that we have available. typ is generally a supertype of original_type. When looking for an attribute of typ, we may perform recursive calls targeting the fallback type, for example. original_type is always the type used in the initial call. """ # TODO: this and following functions share some logic with subtypes.find_member, # consider refactoring. if isinstance(typ, Instance): if name == '__init__' and not is_super: # Accessing __init__ in statically typed code would compromise # type safety unless used via super(). msg.fail(messages.CANNOT_ACCESS_INIT, node) return AnyType(TypeOfAny.from_error) # The base object has an instance type. info = typ.type if override_info: info = override_info if (experiments.find_occurrences and info.name() == experiments.find_occurrences[0] and name == experiments.find_occurrences[1]): msg.note("Occurrence of '{}.{}'".format(*experiments.find_occurrences), node) # Look up the member. First look up the method dictionary. method = info.get_method(name) if method: if method.is_property: assert isinstance(method, OverloadedFuncDef) first_item = cast(Decorator, method.items[0]) return analyze_var(name, first_item.var, typ, info, node, is_lvalue, msg, original_type, not_ready_callback, chk=chk) if is_lvalue: msg.cant_assign_to_method(node) signature = function_type(method, builtin_type('builtins.function')) signature = freshen_function_type_vars(signature) if name == '__new__': # __new__ is special and behaves like a static method -- don't strip # the first argument. pass else: signature = bind_self(signature, original_type) typ = map_instance_to_supertype(typ, method.info) member_type = expand_type_by_instance(signature, typ) freeze_type_vars(member_type) return member_type else: # Not a method. return analyze_member_var_access(name, typ, info, node, is_lvalue, is_super, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, AnyType): # The base object has dynamic type. return AnyType(TypeOfAny.from_another_any, source_any=typ) elif isinstance(typ, NoneTyp): if chk.should_suppress_optional_error([typ]): return AnyType(TypeOfAny.from_error) # The only attribute NoneType has are those it inherits from object return analyze_member_access(name, builtin_type('builtins.object'), node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, UnionType): # The base object has dynamic type. msg.disable_type_names += 1 results = [analyze_member_access(name, subtype, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) for subtype in typ.relevant_items()] msg.disable_type_names -= 1 return UnionType.make_simplified_union(results) elif isinstance(typ, TupleType): # Actually look up from the fallback instance type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, TypedDictType): # Actually look up from the fallback instance type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, FunctionLike) and typ.is_type_obj(): # Class attribute. # TODO super? ret_type = typ.items()[0].ret_type if isinstance(ret_type, TupleType): ret_type = ret_type.fallback if isinstance(ret_type, Instance): if not is_operator: # When Python sees an operator (eg `3 == 4`), it automatically translates that # into something like `int.__eq__(3, 4)` instead of `(3).__eq__(4)` as an # optimization. # # While it normally it doesn't matter which of the two versions are used, it # does cause inconsistencies when working with classes. For example, translating # `int == int` to `int.__eq__(int)` would not work since `int.__eq__` is meant to # compare two int _instances_. What we really want is `type(int).__eq__`, which # is meant to compare two types or classes. # # This check makes sure that when we encounter an operator, we skip looking up # the corresponding method in the current instance to avoid this edge case. # See https://github.com/python/mypy/pull/1787 for more info. result = analyze_class_attribute_access(ret_type, name, node, is_lvalue, builtin_type, not_ready_callback, msg, original_type=original_type) if result: return result # Look up from the 'type' type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) else: assert False, 'Unexpected type {}'.format(repr(ret_type)) elif isinstance(typ, FunctionLike): # Look up from the 'function' type. return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, TypeVarType): return analyze_member_access(name, typ.upper_bound, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) elif isinstance(typ, DeletedType): msg.deleted_as_rvalue(typ, node) return AnyType(TypeOfAny.from_error) elif isinstance(typ, TypeType): # Similar to FunctionLike + is_type_obj() above. item = None fallback = builtin_type('builtins.type') ignore_messages = msg.copy() ignore_messages.disable_errors() if isinstance(typ.item, Instance): item = typ.item elif isinstance(typ.item, AnyType): return analyze_member_access(name, fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, ignore_messages, original_type=original_type, chk=chk) elif isinstance(typ.item, TypeVarType): if isinstance(typ.item.upper_bound, Instance): item = typ.item.upper_bound elif isinstance(typ.item, TupleType): item = typ.item.fallback elif isinstance(typ.item, FunctionLike) and typ.item.is_type_obj(): item = typ.item.fallback elif isinstance(typ.item, TypeType): # Access member on metaclass object via Type[Type[C]] if isinstance(typ.item.item, Instance): item = typ.item.item.type.metaclass_type if item and not is_operator: # See comment above for why operators are skipped result = analyze_class_attribute_access(item, name, node, is_lvalue, builtin_type, not_ready_callback, msg, original_type=original_type) if result: if not (isinstance(result, AnyType) and item.type.fallback_to_any): return result else: # We don't want errors on metaclass lookup for classes with Any fallback msg = ignore_messages if item is not None: fallback = item.type.metaclass_type or fallback return analyze_member_access(name, fallback, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, original_type=original_type, chk=chk) if chk.should_suppress_optional_error([typ]): return AnyType(TypeOfAny.from_error) return msg.has_no_attr(original_type, typ, name, node)
def analyze_descriptor_access(instance_type: Type, descriptor_type: Type, builtin_type: Callable[[str], Instance], msg: MessageBuilder, context: Context, *, chk: 'mypy.checker.TypeChecker') -> Type: """Type check descriptor access. Arguments: instance_type: The type of the instance on which the descriptor attribute is being accessed (the type of ``a`` in ``a.f`` when ``f`` is a descriptor). descriptor_type: The type of the descriptor attribute being accessed (the type of ``f`` in ``a.f`` when ``f`` is a descriptor). context: The node defining the context of this inference. Return: The return type of the appropriate ``__get__`` overload for the descriptor. """ if isinstance(descriptor_type, UnionType): # Map the access over union types return UnionType.make_simplified_union([ analyze_descriptor_access(instance_type, typ, builtin_type, msg, context, chk=chk) for typ in descriptor_type.items ]) elif not isinstance(descriptor_type, Instance): return descriptor_type if not descriptor_type.type.has_readable_member('__get__'): return descriptor_type dunder_get = descriptor_type.type.get_method('__get__') if dunder_get is None: msg.fail( message_registry.DESCRIPTOR_GET_NOT_CALLABLE.format( descriptor_type), context) return AnyType(TypeOfAny.from_error) function = function_type(dunder_get, builtin_type('builtins.function')) bound_method = bind_self(function, descriptor_type) typ = map_instance_to_supertype(descriptor_type, dunder_get.info) dunder_get_type = expand_type_by_instance(bound_method, typ) if isinstance(instance_type, FunctionLike) and instance_type.is_type_obj(): owner_type = instance_type.items()[0].ret_type instance_type = NoneTyp() elif isinstance(instance_type, TypeType): owner_type = instance_type.item instance_type = NoneTyp() else: owner_type = instance_type _, inferred_dunder_get_type = chk.expr_checker.check_call( dunder_get_type, [ TempNode(instance_type), TempNode(TypeType.make_normalized(owner_type)) ], [ARG_POS, ARG_POS], context) if isinstance(inferred_dunder_get_type, AnyType): # check_call failed, and will have reported an error return inferred_dunder_get_type if not isinstance(inferred_dunder_get_type, CallableType): msg.fail( message_registry.DESCRIPTOR_GET_NOT_CALLABLE.format( descriptor_type), context) return AnyType(TypeOfAny.from_error) return inferred_dunder_get_type.ret_type
class TypeChecker(NodeVisitor): """Mypy type checker. Type check mypy source files that have been semantically analysed. """ errors = None # Error message reporting symtable = None # Symbol table for the whole program msg = None # Utility for generating messages type_map = None # Types of type checked nodes expr_checker = None stack = None # Stack of local variable definitions # None separates nested functions return_types = None # Stack of function return types type_context = None # Type context for type inference dynamic_funcs = None # Flags; true for dynamically typed functions globals = None class_tvars = None locals = None modules = None def __init__(self, errors, modules): """Construct a type checker. Use errors to report type check errors. Assume symtable has been populated by the semantic analyzer. """ self.expr_checker self.errors = errors self.modules = modules self.msg = MessageBuilder(errors) self.type_map = {} self.expr_checker = mypy.checkexpr.ExpressionChecker(self, self.msg) self.stack = [None] self.return_types = [] self.type_context = [] self.dynamic_funcs = [] def visit_file(self, file_node, path): """Type check a mypy file with the given path.""" self.errors.set_file(path) self.globals = file_node.names self.locals = None self.class_tvars = None for d in file_node.defs: self.accept(d) def accept(self, node, type_context=None): """Type check a node in the given type context.""" self.type_context.append(type_context) typ = node.accept(self) self.type_context.pop() self.store_type(node, typ) if self.is_dynamic_function(): return Any() else: return typ # # Definitions # def visit_var_def(self, defn): """Type check a variable definition. It can be of any kind: local, member or global. """ # Type check initializer. if defn.init: # There is an initializer. if defn.items[0].type: # Explicit types. if len(defn.items) == 1: self.check_single_assignment(defn.items[0].type, None, defn.init, defn.init) else: # Multiple assignment. lvt = [] for v in defn.items: lvt.append(v.type) self.check_multi_assignment( lvt, [None] * len(lvt), defn.init, defn.init) else: init_type = self.accept(defn.init) if defn.kind == LDEF and not defn.is_top_level: # Infer local variable type if there is an initializer # except if the# definition is at the top level (outside a # function). self.infer_local_variable_type(defn.items, init_type, defn) else: # No initializer if (defn.kind == LDEF and not defn.items[0].type and not defn.is_top_level and not self.is_dynamic_function()): self.fail(messages.NEED_ANNOTATION_FOR_VAR, defn) def infer_local_variable_type(self, x, y, z): # TODO raise RuntimeError('Not implemented') def visit_overloaded_func_def(self, defn): for fdef in defn.items: self.check_func_item(fdef) if defn.info: self.check_method_override(defn) def visit_func_def(self, defn): """Type check a function definition.""" self.check_func_item(defn) if defn.info: self.check_method_override(defn) def check_func_item(self, defn, type_override=None): # We may be checking a function definition or an anonymous function. In # the first case, set up another reference with the precise type. fdef = None if isinstance(defn, FuncDef): fdef = defn self.dynamic_funcs.append(defn.type is None and not type_override) if fdef: self.errors.push_function(fdef.name()) typ = function_type(defn) if type_override: typ = type_override if isinstance(typ, Callable): self.check_func_def(defn, typ) else: raise RuntimeError('Not supported') if fdef: self.errors.pop_function() self.dynamic_funcs.pop() def check_func_def(self, defn, typ): """Check a function definition.""" # We may be checking a function definition or an anonymous function. In # the first case, set up another reference with the precise type. if isinstance(defn, FuncDef): fdef = defn else: fdef = None self.enter() if fdef: # The cast below will work since non-method create will cause # semantic analysis to fail, and type checking won't be done. if (fdef.info and fdef.name() == '__init__' and not isinstance((typ).ret_type, Void) and not self.dynamic_funcs[-1]): self.fail(messages.INIT_MUST_NOT_HAVE_RETURN_TYPE, defn.type) # Push return type. self.return_types.append((typ).ret_type) # Store argument types. ctype = typ nargs = len(defn.args) for i in range(len(ctype.arg_types)): arg_type = ctype.arg_types[i] if ctype.arg_kinds[i] == nodes.ARG_STAR: arg_type = self.named_generic_type('builtins.list', [arg_type]) elif ctype.arg_kinds[i] == nodes.ARG_STAR2: arg_type = self.named_generic_type('builtins.dict', [self.str_type(), arg_type]) defn.args[i].type = arg_type # Type check initialization expressions. for j in range(len(defn.init)): if defn.init[j]: self.accept(defn.init[j]) # Type check body. self.accept(defn.body) # Pop return type. self.return_types.pop() self.leave() def check_method_override(self, defn): """Check that function definition is compatible with any overridden definitions defined in superclasses or implemented interfaces. """ # Check against definitions in superclass. self.check_method_or_accessor_override_for_base(defn, defn.info.base) # Check against definitions in implemented interfaces. for iface in defn.info.interfaces: self.check_method_or_accessor_override_for_base(defn, iface) def check_method_or_accessor_override_for_base(self, defn, base): """Check that function definition is compatible with any overridden definition in the specified supertype. """ if base: if defn.name() != '__init__': # Check method override (create is special). base_method = base.get_method(defn.name()) if base_method and base_method.info == base: # There is an overridden method in the supertype. # Construct the type of the overriding method. typ = method_type(defn) # Map the overridden method type to subtype context so that # it can be checked for compatibility. Note that multiple # types from multiple implemented interface instances may # be present. original_type = map_type_from_supertype( method_type(base_method), defn.info, base) # Check that the types are compatible. # TODO overloaded signatures self.check_override(typ, original_type, defn.name(), base_method.info.name(), defn) # Also check interface implementations. for iface in base.interfaces: self.check_method_or_accessor_override_for_base(defn, iface) # We have to check that the member is compatible with all # supertypes due to the dynamic type. Otherwise we could first # override with dynamic and then with an arbitary type. self.check_method_or_accessor_override_for_base(defn, base.base) def check_override(self, override, original, name, supertype, node): """Check a method override with given signatures. Arguments: override: The signature of the overriding method. original: The signature of the original supertype method. name: The name of the subtype. This and the next argument are only used for generating error messages. supertype: The name of the supertype. """ if (isinstance(override, Overloaded) or isinstance(original, Overloaded) or len((override).arg_types) != len((original).arg_types) or (override).min_args != (original).min_args): if not is_subtype(override, original): self.msg.signature_incompatible_with_supertype( name, supertype, node) return else: # Give more detailed messages for the common case of both # signatures having the same number of arguments and no # intersection types. coverride = override coriginal = original for i in range(len(coverride.arg_types)): if not is_equivalent(coriginal.arg_types[i], coverride.arg_types[i]): self.msg.argument_incompatible_with_supertype( i + 1, name, supertype, node) if not is_subtype(coverride.ret_type, coriginal.ret_type): self.msg.return_type_incompatible_with_supertype( name, supertype, node) def visit_type_def(self, defn): """Type check a type definition (class or interface).""" typ = self.lookup(defn.name, GDEF).node self.errors.set_type(defn.name, defn.is_interface) self.check_unique_interface_implementations(typ) self.check_interface_errors(typ) self.check_no_constructor_if_interface(typ) self.accept(defn.defs) self.errors.set_type(None, False) def check_no_constructor_if_interface(self, typ): if not typ.is_interface: return ctor = typ.get_method('__init__') if ctor is None: return self.msg.interface_has_constructor(ctor) def check_unique_interface_implementations(self, typ): """Check that each interface is implemented only once.""" ifaces = typ.interfaces[:] dup = find_duplicate(ifaces) if dup: self.msg.duplicate_interfaces(typ, dup) return base = typ.base while base: # Avoid duplicate error messages. if find_duplicate(base.interfaces): return ifaces.extend(base.interfaces) dup = find_duplicate(ifaces) if dup: self.msg.duplicate_interfaces(typ, dup) return base = base.base def check_interface_errors(self, typ): interfaces = typ.all_directly_implemented_interfaces() for iface in interfaces: for n in iface.methods.keys(): if not typ.has_method(n): self.msg.interface_member_not_implemented(typ, iface, n) # # Statements # def visit_block(self, b): for s in b.body: self.accept(s) def visit_assignment_stmt(self, s): """Type check an assignment statement. Handle all kinds of assignment statements (simple, indexed, multiple). """ # TODO support chained assignment x = y = z if len(s.lvalues) > 1: self.msg.not_implemented('chained assignment', s) self.check_assignments(self.expand_lvalues(s.lvalues[0]), s.rvalue) def check_assignments(self, lvalues, rvalue): # Collect lvalue types. Index lvalues require special consideration, # since we cannot typecheck them until we know the rvalue type. # For each lvalue, one of lvalue_types[i] or index_lvalues[i] is not # None. lvalue_types = [] # Each may be None index_lvalues = [] # Each may be None inferred = [] is_inferred = False for lv in lvalues: if self.is_definition(lv): is_inferred = True if isinstance(lv, NameExpr): n = lv inferred.append((n.node)) else: m = lv self.accept(m.expr) inferred.append(m.def_var) lvalue_types.append(None) index_lvalues.append(None) elif isinstance(lv, IndexExpr): ilv = lv lvalue_types.append(None) index_lvalues.append(ilv) inferred.append(None) else: lvalue_types.append(self.accept(lv)) index_lvalues.append(None) inferred.append(None) if len(lvalues) == 1: # Single lvalue. self.check_single_assignment(lvalue_types[0], index_lvalues[0], rvalue, rvalue) else: self.check_multi_assignment(lvalue_types, index_lvalues, rvalue, rvalue) if is_inferred: self.infer_variable_type(inferred, lvalues, self.accept(rvalue), rvalue) def is_definition(self, s): return ((isinstance(s, NameExpr) or isinstance(s, MemberExpr)) and s.is_def) def expand_lvalues(self, n): if isinstance(n, TupleExpr): return self.expr_checker.unwrap_list((n).items) elif isinstance(n, ListExpr): return self.expr_checker.unwrap_list((n).items) elif isinstance(n, ParenExpr): return self.expand_lvalues((n).expr) else: return [n] def infer_variable_type(self, names, lvalues, init_type, context): """Infer the type of initialized variables from initializer type.""" if isinstance(init_type, Void): self.check_not_void(init_type, context) elif not self.is_valid_inferred_type(init_type): # We cannot use the type of the initialization expression for type # inference (it's not specific enough). self.fail(messages.NEED_ANNOTATION_FOR_VAR, context) else: # Infer type of the target. # Make the type more general (strip away function names etc.). init_type = strip_type(init_type) if len(names) > 1: if isinstance(init_type, TupleType): tinit_type = init_type # Initializer with a tuple type. if len(tinit_type.items) == len(names): for i in range(len(names)): self.set_inferred_type(names[i], lvalues[i], tinit_type.items[i]) else: self.msg.incompatible_value_count_in_assignment( len(names), len(tinit_type.items), context) elif (isinstance(init_type, Instance) and (init_type).type.full_name() == 'builtins.list'): # Initializer with an array type. item_type = (init_type).args[0] for i in range(len(names)): self.set_inferred_type(names[i], lvalues[i], item_type) elif isinstance(init_type, Any): for i in range(len(names)): self.set_inferred_type(names[i], lvalues[i], Any()) else: self.fail(messages.INCOMPATIBLE_TYPES_IN_ASSIGNMENT, context) else: for v in names: self.set_inferred_type(v, lvalues[0], init_type) def set_inferred_type(self, var, lvalue, type): """Store inferred variable type. Store the type to both the variable node and the expression node that refers to the variable (lvalue). If var is None, do nothing. """ if var: var.type = type self.store_type(lvalue, type) def is_valid_inferred_type(self, typ): """Is an inferred type invalid? Examples include the None type or a type with a None component. """ if is_same_type(typ, NoneTyp()): return False elif isinstance(typ, Instance): for arg in (typ).args: if not self.is_valid_inferred_type(arg): return False elif isinstance(typ, TupleType): for item in (typ).items: if not self.is_valid_inferred_type(item): return False return True def check_multi_assignment(self, lvalue_types, index_lvalues, rvalue, context, msg=None): if not msg: msg = messages.INCOMPATIBLE_TYPES_IN_ASSIGNMENT rvalue_type = self.accept(rvalue) # TODO maybe elsewhere; redundant # Try to expand rvalue to lvalue(s). if isinstance(rvalue_type, Any): pass elif isinstance(rvalue_type, TupleType): # Rvalue with tuple type. trvalue = rvalue_type items = [] for i in range(len(lvalue_types)): if lvalue_types[i]: items.append(lvalue_types[i]) elif i < len(trvalue.items): # TODO Figure out more precise type context, probably # based on the type signature of the _set method. items.append(trvalue.items[i]) trvalue = (self.accept(rvalue, TupleType(items))) if len(trvalue.items) != len(lvalue_types): self.msg.incompatible_value_count_in_assignment( len(lvalue_types), len(trvalue.items), context) else: # The number of values is compatible. Check their types. for j in range(len(lvalue_types)): self.check_single_assignment( lvalue_types[j], index_lvalues[j], self.temp_node(trvalue.items[j]), context, msg) elif (isinstance(rvalue_type, Instance) and (rvalue_type).type.full_name() == 'builtins.list'): # Rvalue with list type. item_type = (rvalue_type).args[0] for k in range(len(lvalue_types)): self.check_single_assignment(lvalue_types[k], index_lvalues[k], self.temp_node(item_type), context, msg) else: self.fail(msg, context) def check_single_assignment(self, lvalue_type, index_lvalue, rvalue, context, msg=messages.INCOMPATIBLE_TYPES_IN_ASSIGNMENT): """Type check an assignment. If lvalue_type is None, the index_lvalue argument must be the index expr for indexed assignment (__setitem__). Otherwise, lvalue_type is used as the type of the lvalue. """ if lvalue_type: rvalue_type = self.accept(rvalue, lvalue_type) self.check_subtype(rvalue_type, lvalue_type, context, msg) elif index_lvalue: self.check_indexed_assignment(index_lvalue, rvalue, context) def check_indexed_assignment(self, lvalue, rvalue, context): """Type check indexed assignment base[index] = rvalue. The lvalue argument is the base[index] expression. """ basetype = self.accept(lvalue.base) method_type = self.expr_checker.analyse_external_member_access( '__setitem__', basetype, context) lvalue.method_type = method_type self.expr_checker.check_call(method_type, [lvalue.index, rvalue], [nodes.ARG_POS, nodes.ARG_POS], context) def visit_expression_stmt(self, s): self.accept(s.expr) def visit_return_stmt(self, s): """Type check a return statement.""" if self.is_within_function(): if s.expr: # Return with a value. typ = self.accept(s.expr, self.return_types[-1]) # Returning a value of type dynamic is always fine. if not isinstance(typ, Any): if isinstance(self.return_types[-1], Void): self.fail(messages.NO_RETURN_VALUE_EXPECTED, s) else: self.check_subtype( typ, self.return_types[-1], s, messages.INCOMPATIBLE_RETURN_VALUE_TYPE) else: # Return without a value. if (not isinstance(self.return_types[-1], Void) and not self.is_dynamic_function()): self.fail(messages.RETURN_VALUE_EXPECTED, s) def visit_yield_stmt(self, s): return_type = self.return_types[-1] if isinstance(return_type, Instance): inst = return_type if inst.type.full_name() != 'builtins.Iterator': self.fail(messages.INVALID_RETURN_TYPE_FOR_YIELD, s) return None expected_item_type = inst.args[0] elif isinstance(return_type, Any): expected_item_type = Any() else: self.fail(messages.INVALID_RETURN_TYPE_FOR_YIELD, s) return None actual_item_type = self.accept(s.expr, expected_item_type) self.check_subtype(actual_item_type, expected_item_type, s) def visit_if_stmt(self, s): """Type check an if statement.""" for e in s.expr: t = self.accept(e) self.check_not_void(t, e) for b in s.body: self.accept(b) if s.else_body: self.accept(s.else_body) def visit_while_stmt(self, s): """Type check a while statement.""" t = self.accept(s.expr) self.check_not_void(t, s) self.accept(s.body) if s.else_body: self.accept(s.else_body) def visit_operator_assignment_stmt(self, s): """Type check an operator assignment statement, e.g. x += 1.""" lvalue_type = self.accept(s.lvalue) rvalue_type, method_type = self.expr_checker.check_op( nodes.op_methods[s.op], lvalue_type, s.rvalue, s) if isinstance(s.lvalue, IndexExpr): lv = s.lvalue self.check_single_assignment(None, lv, s.rvalue, s.rvalue) else: if not is_subtype(rvalue_type, lvalue_type): self.msg.incompatible_operator_assignment(s.op, s) def visit_assert_stmt(self, s): self.accept(s.expr) def visit_raise_stmt(self, s): """Type check a raise statement.""" typ = self.accept(s.expr) self.check_subtype(typ, self.named_type('builtins.BaseException'), s, messages.INVALID_EXCEPTION_TYPE) def visit_try_stmt(self, s): """Type check a try statement.""" self.accept(s.body) for i in range(len(s.handlers)): if s.types[i]: t = self.exception_type(s.types[i]) if s.vars[i]: s.vars[i].type = t self.accept(s.handlers[i]) if s.finally_body: self.accept(s.finally_body) if s.else_body: self.accept(s.else_body) def exception_type(self, n): if isinstance(n, NameExpr): name = n if isinstance(name.node, TypeInfo): return self.check_exception_type(name.node, n) elif isinstance(n, MemberExpr): m = n if isinstance(m.node, TypeInfo): return self.check_exception_type(m.node, n) elif isinstance(self.expr_checker.unwrap(n), TupleExpr): self.fail('Multiple exception types not supported yet', n) return Any() self.fail('Unsupported exception', n) return Any() def check_exception_type(self, info, context): t = Instance(info, []) if is_subtype(t, self.named_type('builtins.BaseException')): return t else: self.fail(messages.INVALID_EXCEPTION_TYPE, context) return Any() def visit_for_stmt(self, s): """Type check a for statement.""" item_type = self.analyse_iterable_item_type(s.expr) self.analyse_index_variables(s.index, s.is_annotated(), item_type, s) self.accept(s.body) def analyse_iterable_item_type(self, expr): """Analyse iterable expression and return iterator item type.""" iterable = self.accept(expr) self.check_not_void(iterable, expr) self.check_subtype(iterable, self.named_generic_type('builtins.Iterable', [Any()]), expr, messages.ITERABLE_EXPECTED) echk = self.expr_checker method = echk.analyse_external_member_access('__iter__', iterable, expr) iterator = echk.check_call(method, [], [], expr)[0] method = echk.analyse_external_member_access('__next__', iterator, expr) return echk.check_call(method, [], [], expr)[0] def analyse_index_variables(self, index, is_annotated, item_type, context): """Type check or infer for loop or list comprehension index vars.""" if not is_annotated: # Create a temporary copy of variables with Node item type. # TODO this is ugly node_index = [] for i in index: node_index.append(i) self.check_assignments(node_index, self.temp_node(item_type, context)) elif len(index) == 1: v = index[0].node if v.type: self.check_single_assignment(v.type, None, self.temp_node(item_type), context, messages.INCOMPATIBLE_TYPES_IN_FOR) else: t = [] for ii in index: v = ii.node if v.type: t.append(v.type) else: t.append(Any()) self.check_multi_assignment(t, [None] * len(index), self.temp_node(item_type), context, messages.INCOMPATIBLE_TYPES_IN_FOR) def visit_del_stmt(self, s): if isinstance(s.expr, IndexExpr): e = s.expr # Cast m = MemberExpr(e.base, '__delitem__') m.line = s.line c = CallExpr(m, [e.index], [nodes.ARG_POS], [None]) c.line = s.line return c.accept(self) else: return None # this case is handled in semantical analysis # # Expressions # def visit_name_expr(self, e): return self.expr_checker.visit_name_expr(e) def visit_paren_expr(self, e): return self.expr_checker.visit_paren_expr(e) def visit_call_expr(self, e): return self.expr_checker.visit_call_expr(e) def visit_member_expr(self, e): return self.expr_checker.visit_member_expr(e) def visit_int_expr(self, e): return self.expr_checker.visit_int_expr(e) def visit_str_expr(self, e): return self.expr_checker.visit_str_expr(e) def visit_bytes_expr(self, e): return self.expr_checker.visit_bytes_expr(e) def visit_float_expr(self, e): return self.expr_checker.visit_float_expr(e) def visit_op_expr(self, e): return self.expr_checker.visit_op_expr(e) def visit_unary_expr(self, e): return self.expr_checker.visit_unary_expr(e) def visit_index_expr(self, e): return self.expr_checker.visit_index_expr(e) def visit_cast_expr(self, e): return self.expr_checker.visit_cast_expr(e) def visit_super_expr(self, e): return self.expr_checker.visit_super_expr(e) def visit_type_application(self, e): return self.expr_checker.visit_type_application(e) def visit_list_expr(self, e): return self.expr_checker.visit_list_expr(e) def visit_tuple_expr(self, e): return self.expr_checker.visit_tuple_expr(e) def visit_dict_expr(self, e): return self.expr_checker.visit_dict_expr(e) def visit_slice_expr(self, e): return self.expr_checker.visit_slice_expr(e) def visit_func_expr(self, e): return self.expr_checker.visit_func_expr(e) def visit_list_comprehension(self, e): return self.expr_checker.visit_list_comprehension(e) def visit_generator_expr(self, e): return self.expr_checker.visit_generator_expr(e) def visit_temp_node(self, e): return e.type # # Currently unsupported features # def visit_set_expr(self, e): return self.msg.not_implemented('set literal', e) def visit_conditional_expr(self, e): return self.msg.not_implemented('conditional expression', e) def visit_decorator(self, e): return self.msg.not_implemented('decorator', e) def visit_with_stmt(self, s): self.msg.not_implemented('with statement', s) # # Helpers # def check_subtype(self, subtype, supertype, context, msg=messages.INCOMPATIBLE_TYPES): """Generate an error if the subtype is not compatible with supertype.""" if not is_subtype(subtype, supertype): if isinstance(subtype, Void): self.msg.does_not_return_value(subtype, context) else: self.fail(msg, context) def named_type(self, name): """Return an instance type with type given by the name and no type arguments. For example, named_type('builtins.object') produces the object type. """ # Assume that the name refers to a type. sym = self.lookup_qualified(name) return Instance(sym.node, []) def named_type_if_exists(self, name): """Return named instance type, or UnboundType if the type was not defined. This is used to simplify test cases by avoiding the need to define basic types not needed in specific test cases (tuple etc.). """ try: # Assume that the name refers to a type. sym = self.lookup_qualified(name) return Instance(sym.node, []) except KeyError: return UnboundType(name) def named_generic_type(self, name, args): """Return an instance with the given name and type arguments. Assume that the number of arguments is correct. """ # Assume that the name refers to a compatible generic type. sym = self.lookup_qualified(name) return Instance(sym.node, args) def type_type(self): """Return instance type 'type'.""" return self.named_type('builtins.type') def object_type(self): """Return instance type 'object'.""" return self.named_type('builtins.object') def bool_type(self): """Return instance type 'bool'.""" return self.named_type('builtins.bool') def str_type(self): """Return instance type 'str'.""" return self.named_type('builtins.str') def tuple_type(self): """Return instance type 'tuple'.""" # We need the tuple for analysing member access. We want to be able to # do this even if tuple type is not available (useful in test cases), # so we return an unbound type if there is no tuple type. return self.named_type_if_exists('builtins.tuple') def check_type_equivalency(self, t1, t2, node, msg=messages.INCOMPATIBLE_TYPES): """Generate an error if the types are not equivalent. The dynamic type is equivalent with all types. """ if not is_equivalent(t1, t2): self.fail(msg, node) def store_type(self, node, typ): """Store the type of a node in the type map.""" self.type_map[node] = typ def is_dynamic_function(self): return len(self.dynamic_funcs) > 0 and self.dynamic_funcs[-1] def lookup(self, name, kind): """Look up a definition from the symbol table with the given name. TODO remove kind argument """ if self.locals is not None and name in self.locals: return self.locals[name] elif self.class_tvars is not None and name in self.class_tvars: return self.class_tvars[name] elif name in self.globals: return self.globals[name] else: b = self.globals.get('__builtins__', None) if b: table = (b.node).names if name in table: return table[name] raise KeyError('Failed lookup: {}'.format(name)) def lookup_qualified(self, name): if '.' not in name: return self.lookup(name, GDEF) # FIX kind else: parts = name.split('.') n = self.modules[parts[0]] for i in range(1, len(parts) - 1): n = ((n.names.get(parts[i], None).node)) return n.names[parts[-1]] def enter(self): self.locals = SymbolTable() def leave(self): self.locals = None def basic_types(self): """Return a BasicTypes instance that contains primitive types that are needed for certain type operations (joins, for example). """ # TODO function type return BasicTypes(self.object_type(), self.type_type(), self.named_type_if_exists('builtins.tuple'), self.named_type_if_exists('builtins.function')) def is_within_function(self): """Are we currently type checking within a function (i.e. not at class body or at the top level)? """ return self.return_types != [] def check_not_void(self, typ, context): """Generate an error if the type is Void.""" if isinstance(typ, Void): self.msg.does_not_return_value(typ, context) def temp_node(self, t, context=None): """Create a temporary node with the given, fixed type.""" temp = TempNode(t) if context: temp.set_line(context.get_line()) return temp def fail(self, msg, context): """Produce an error message.""" self.msg.fail(msg, context)