from __future__ import annotations
from typing import NamedTuple
from mypy.argmap import map_actuals_to_formals
from mypy.fixup import TypeFixer
from mypy.nodes import (
ARG_POS,
MDEF,
SYMBOL_FUNCBASE_TYPES,
Argument,
Block,
CallExpr,
ClassDef,
Decorator,
Expression,
FuncDef,
JsonDict,
NameExpr,
Node,
OverloadedFuncDef,
PassStmt,
RefExpr,
SymbolTableNode,
TypeInfo,
Var,
)
from mypy.plugin import CheckerPluginInterface, ClassDefContext, SemanticAnalyzerPluginInterface
from mypy.semanal_shared import (
ALLOW_INCOMPATIBLE_OVERRIDE,
parse_bool,
require_bool_literal_argument,
set_callable_name,
)
from mypy.typeops import try_getting_str_literals as try_getting_str_literals
from mypy.types import (
AnyType,
CallableType,
Instance,
LiteralType,
NoneType,
Overloaded,
Type,
TypeOfAny,
TypeType,
TypeVarType,
deserialize_type,
get_proper_type,
)
from mypy.types_utils import is_overlapping_none
from mypy.typevars import fill_typevars
from mypy.util import get_unique_redefinition_name
def _get_decorator_bool_argument(ctx: ClassDefContext, name: str, default: bool) -> bool:
"""Return the bool argument for the decorator.
This handles both @decorator(...) and @decorator.
"""
if isinstance(ctx.reason, CallExpr):
return _get_bool_argument(ctx, ctx.reason, name, default)
else:
return default
def _get_bool_argument(ctx: ClassDefContext, expr: CallExpr, name: str, default: bool) -> bool:
"""Return the boolean value for an argument to a call or the
default if it's not found.
"""
attr_value = _get_argument(expr, name)
if attr_value:
return require_bool_literal_argument(ctx.api, attr_value, name, default)
return default
def _get_argument(call: CallExpr, name: str) -> Expression | None:
"""Return the expression for the specific argument."""
# To do this we use the CallableType of the callee to find the FormalArgument,
# then walk the actual CallExpr looking for the appropriate argument.
#
# Note: I'm not hard-coding the index so that in the future we can support other
# attrib and class makers.
callee_type = _get_callee_type(call)
if not callee_type:
return None
argument = callee_type.argument_by_name(name)
if not argument:
return None
assert argument.name
for i, (attr_name, attr_value) in enumerate(zip(call.arg_names, call.args)):
if argument.pos is not None and not attr_name and i == argument.pos:
return attr_value
if attr_name == argument.name:
return attr_value
return None
def find_shallow_matching_overload_item(overload: Overloaded, call: CallExpr) -> CallableType:
"""Perform limited lookup of a matching overload item.
Full overload resolution is only supported during type checking, but plugins
sometimes need to resolve overloads. This can be used in some such use cases.
Resolve overloads based on these things only:
* Match using argument kinds and names
* If formal argument has type None, only accept the "None" expression in the callee
* If formal argument has type Literal[True] or Literal[False], only accept the
relevant bool literal
Return the first matching overload item, or the last one if nothing matches.
"""
for item in overload.items[:-1]:
ok = True
mapped = map_actuals_to_formals(
call.arg_kinds,
call.arg_names,
item.arg_kinds,
item.arg_names,
lambda i: AnyType(TypeOfAny.special_form),
)
# Look for extra actuals
matched_actuals = set()
for actuals in mapped:
matched_actuals.update(actuals)
if any(i not in matched_actuals for i in range(len(call.args))):
ok = False
for arg_type, kind, actuals in zip(item.arg_types, item.arg_kinds, mapped):
if kind.is_required() and not actuals:
# Missing required argument
ok = False
break
elif actuals:
args = [call.args[i] for i in actuals]
arg_type = get_proper_type(arg_type)
arg_none = any(isinstance(arg, NameExpr) and arg.name == "None" for arg in args)
if isinstance(arg_type, NoneType):
if not arg_none:
ok = False
break
elif (
arg_none
and not is_overlapping_none(arg_type)
and not (
isinstance(arg_type, Instance)
and arg_type.type.fullname == "builtins.object"
)
and not isinstance(arg_type, AnyType)
):
ok = False
break
elif isinstance(arg_type, LiteralType) and isinstance(arg_type.value, bool):
if not any(parse_bool(arg) == arg_type.value for arg in args):
ok = False
break
if ok:
return item
return overload.items[-1]
def _get_callee_type(call: CallExpr) -> CallableType | None:
"""Return the type of the callee, regardless of its syntactic form."""
callee_node: Node | None = call.callee
if isinstance(callee_node, RefExpr):
callee_node = callee_node.node
# Some decorators may be using typing.dataclass_transform, which is itself a decorator, so we
# need to unwrap them to get at the true callee
if isinstance(callee_node, Decorator):
callee_node = callee_node.func
if isinstance(callee_node, (Var, SYMBOL_FUNCBASE_TYPES)) and callee_node.type:
callee_node_type = get_proper_type(callee_node.type)
if isinstance(callee_node_type, Overloaded):
return find_shallow_matching_overload_item(callee_node_type, call)
elif isinstance(callee_node_type, CallableType):
return callee_node_type
return None
def add_method(
ctx: ClassDefContext,
name: str,
args: list[Argument],
return_type: Type,
self_type: Type | None = None,
tvar_def: TypeVarType | None = None,
is_classmethod: bool = False,
is_staticmethod: bool = False,
) -> None:
"""
Adds a new method to a class.
Deprecated, use add_method_to_class() instead.
"""
add_method_to_class(
ctx.api,
ctx.cls,
name=name,
args=args,
return_type=return_type,
self_type=self_type,
tvar_def=tvar_def,
is_classmethod=is_classmethod,
is_staticmethod=is_staticmethod,
)
class MethodSpec(NamedTuple):
"""Represents a method signature to be added, except for `name`."""
args: list[Argument]
return_type: Type
self_type: Type | None = None
tvar_defs: list[TypeVarType] | None = None
def add_method_to_class(
api: SemanticAnalyzerPluginInterface | CheckerPluginInterface,
cls: ClassDef,
name: str,
# MethodSpec items kept for backward compatibility:
args: list[Argument],
return_type: Type,
self_type: Type | None = None,
tvar_def: list[TypeVarType] | TypeVarType | None = None,
is_classmethod: bool = False,
is_staticmethod: bool = False,
) -> FuncDef | Decorator:
"""Adds a new method to a class definition."""
_prepare_class_namespace(cls, name)
if tvar_def is not None and not isinstance(tvar_def, list):
tvar_def = [tvar_def]
func, sym = _add_method_by_spec(
api,
cls.info,
name,
MethodSpec(args=args, return_type=return_type, self_type=self_type, tvar_defs=tvar_def),
is_classmethod=is_classmethod,
is_staticmethod=is_staticmethod,
)
cls.info.names[name] = sym
cls.info.defn.defs.body.append(func)
return func
def add_overloaded_method_to_class(
api: SemanticAnalyzerPluginInterface | CheckerPluginInterface,
cls: ClassDef,
name: str,
items: list[MethodSpec],
is_classmethod: bool = False,
is_staticmethod: bool = False,
) -> OverloadedFuncDef:
"""Adds a new overloaded method to a class definition."""
assert len(items) >= 2, "Overloads must contain at least two cases"
# Save old definition, if it exists.
_prepare_class_namespace(cls, name)
# Create function bodies for each passed method spec.
funcs: list[Decorator | FuncDef] = []
for item in items:
func, _sym = _add_method_by_spec(
api,
cls.info,
name=name,
spec=item,
is_classmethod=is_classmethod,
is_staticmethod=is_staticmethod,
)
if isinstance(func, FuncDef):
var = Var(func.name, func.type)
var.set_line(func.line)
func.is_decorated = True
deco = Decorator(func, [], var)
else:
deco = func
deco.is_overload = True
funcs.append(deco)
# Create the final OverloadedFuncDef node:
overload_def = OverloadedFuncDef(funcs)
overload_def.info = cls.info
overload_def.is_class = is_classmethod
overload_def.is_static = is_staticmethod
sym = SymbolTableNode(MDEF, overload_def)
sym.plugin_generated = True
cls.info.names[name] = sym
cls.info.defn.defs.body.append(overload_def)
return overload_def
def _prepare_class_namespace(cls: ClassDef, name: str) -> None:
info = cls.info
assert info
# First remove any previously generated methods with the same name
# to avoid clashes and problems in the semantic analyzer.
if name in info.names:
sym = info.names[name]
if sym.plugin_generated and isinstance(sym.node, FuncDef):
cls.defs.body.remove(sym.node)
# NOTE: we would like the plugin generated node to dominate, but we still
# need to keep any existing definitions so they get semantically analyzed.
if name in info.names:
# Get a nice unique name instead.
r_name = get_unique_redefinition_name(name, info.names)
info.names[r_name] = info.names[name]
def _add_method_by_spec(
api: SemanticAnalyzerPluginInterface | CheckerPluginInterface,
info: TypeInfo,
name: str,
spec: MethodSpec,
*,
is_classmethod: bool,
is_staticmethod: bool,
) -> tuple[FuncDef | Decorator, SymbolTableNode]:
args, return_type, self_type, tvar_defs = spec
assert not (
is_classmethod is True and is_staticmethod is True
), "Can't add a new method that's both staticmethod and classmethod."
if isinstance(api, SemanticAnalyzerPluginInterface):
function_type = api.named_type("builtins.function")
else:
function_type = api.named_generic_type("builtins.function", [])
if is_classmethod:
self_type = self_type or TypeType(fill_typevars(info))
first = [Argument(Var("_cls"), self_type, None, ARG_POS, True)]
elif is_staticmethod:
first = []
else:
self_type = self_type or fill_typevars(info)
first = [Argument(Var("self"), self_type, None, ARG_POS)]
args = first + args
arg_types, arg_names, arg_kinds = [], [], []
for arg in args:
assert arg.type_annotation, "All arguments must be fully typed."
arg_types.append(arg.type_annotation)
arg_names.append(arg.variable.name)
arg_kinds.append(arg.kind)
signature = CallableType(arg_types, arg_kinds, arg_names, return_type, function_type)
if tvar_defs:
signature.variables = tvar_defs
func = FuncDef(name, args, Block([PassStmt()]))
func.info = info
func.type = set_callable_name(signature, func)
func.is_class = is_classmethod
func.is_static = is_staticmethod
func._fullname = info.fullname + "." + name
func.line = info.line
# Add decorator for is_staticmethod. It's unnecessary for is_classmethod.
if is_staticmethod:
func.is_decorated = True
v = Var(name, func.type)
v.info = info
v._fullname = func._fullname
v.is_staticmethod = True
dec = Decorator(func, [], v)
dec.line = info.line
sym = SymbolTableNode(MDEF, dec)
sym.plugin_generated = True
return dec, sym
sym = SymbolTableNode(MDEF, func)
sym.plugin_generated = True
return func, sym
def add_attribute_to_class(
api: SemanticAnalyzerPluginInterface,
cls: ClassDef,
name: str,
typ: Type,
final: bool = False,
no_serialize: bool = False,
override_allow_incompatible: bool = False,
fullname: str | None = None,
is_classvar: bool = False,
overwrite_existing: bool = False,
) -> Var:
"""
Adds a new attribute to a class definition.
This currently only generates the symbol table entry and no corresponding AssignmentStatement
"""
info = cls.info
# NOTE: we would like the plugin generated node to dominate, but we still
# need to keep any existing definitions so they get semantically analyzed.
if name in info.names and not overwrite_existing:
# Get a nice unique name instead.
r_name = get_unique_redefinition_name(name, info.names)
info.names[r_name] = info.names[name]
node = Var(name, typ)
node.info = info
node.is_final = final
node.is_classvar = is_classvar
if name in ALLOW_INCOMPATIBLE_OVERRIDE:
node.allow_incompatible_override = True
else:
node.allow_incompatible_override = override_allow_incompatible
if fullname:
node._fullname = fullname
else:
node._fullname = info.fullname + "." + name
info.names[name] = SymbolTableNode(
MDEF, node, plugin_generated=True, no_serialize=no_serialize
)
return node
def deserialize_and_fixup_type(data: str | JsonDict, api: SemanticAnalyzerPluginInterface) -> Type:
typ = deserialize_type(data)
typ.accept(TypeFixer(api.modules, allow_missing=False))
return typ
