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# Copyright 2013-2021 The Meson development team
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import annotations
from .. import mparser
from .exceptions import InvalidCode, InvalidArguments
from .helpers import flatten, resolve_second_level_holders
from .operator import MesonOperator
from ..mesonlib import HoldableObject, MesonBugException
import textwrap
import typing as T
from abc import ABCMeta
from contextlib import AbstractContextManager
if T.TYPE_CHECKING:
from typing_extensions import Protocol
# Object holders need the actual interpreter
from ..interpreter import Interpreter
__T = T.TypeVar('__T', bound='TYPE_var', contravariant=True)
class OperatorCall(Protocol[__T]):
def __call__(self, other: __T) -> 'TYPE_var': ...
TV_func = T.TypeVar('TV_func', bound=T.Callable[..., T.Any])
TYPE_elementary = T.Union[str, int, bool, T.List[T.Any], T.Dict[str, T.Any]]
TYPE_var = T.Union[TYPE_elementary, HoldableObject, 'MesonInterpreterObject']
TYPE_nvar = T.Union[TYPE_var, mparser.BaseNode]
TYPE_kwargs = T.Dict[str, TYPE_var]
TYPE_nkwargs = T.Dict[str, TYPE_nvar]
TYPE_key_resolver = T.Callable[[mparser.BaseNode], str]
SubProject = T.NewType('SubProject', str)
class InterpreterObject:
def __init__(self, *, subproject: T.Optional['SubProject'] = None) -> None:
self.methods: T.Dict[
str,
T.Callable[[T.List[TYPE_var], TYPE_kwargs], TYPE_var]
] = {}
self.operators: T.Dict[MesonOperator, 'OperatorCall'] = {}
self.trivial_operators: T.Dict[
MesonOperator,
T.Tuple[
T.Union[T.Type, T.Tuple[T.Type, ...]],
'OperatorCall'
]
] = {}
# Current node set during a method call. This can be used as location
# when printing a warning message during a method call.
self.current_node: mparser.BaseNode = None
self.subproject = subproject or SubProject('')
# Some default operators supported by all objects
self.operators.update({
MesonOperator.EQUALS: self.op_equals,
MesonOperator.NOT_EQUALS: self.op_not_equals,
})
# The type of the object that can be printed to the user
def display_name(self) -> str:
return type(self).__name__
def method_call(
self,
method_name: str,
args: T.List[TYPE_var],
kwargs: TYPE_kwargs
) -> TYPE_var:
if method_name in self.methods:
method = self.methods[method_name]
if not getattr(method, 'no-args-flattening', False):
args = flatten(args)
if not getattr(method, 'no-second-level-holder-flattening', False):
args, kwargs = resolve_second_level_holders(args, kwargs)
return method(args, kwargs)
raise InvalidCode(f'Unknown method "{method_name}" in object {self} of type {type(self).__name__}.')
def operator_call(self, operator: MesonOperator, other: TYPE_var) -> TYPE_var:
if operator in self.trivial_operators:
op = self.trivial_operators[operator]
if op[0] is None and other is not None:
raise MesonBugException(f'The unary operator `{operator.value}` of {self.display_name()} was passed the object {other} of type {type(other).__name__}')
if op[0] is not None and not isinstance(other, op[0]):
raise InvalidArguments(f'The `{operator.value}` operator of {self.display_name()} does not accept objects of type {type(other).__name__} ({other})')
return op[1](other)
if operator in self.operators:
return self.operators[operator](other)
raise InvalidCode(f'Object {self} of type {self.display_name()} does not support the `{operator.value}` operator.')
# Default comparison operator support
def _throw_comp_exception(self, other: TYPE_var, opt_type: str) -> T.NoReturn:
raise InvalidArguments(textwrap.dedent(
f'''
Trying to compare values of different types ({self.display_name()}, {type(other).__name__}) using {opt_type}.
This was deprecated and undefined behavior previously and is as of 0.60.0 a hard error.
'''
))
def op_equals(self, other: TYPE_var) -> bool:
# We use `type(...) == type(...)` here to enforce an *exact* match for comparison. We
# don't want comparisons to be possible where `isinstance(derived_obj, type(base_obj))`
# would pass because this comparison must never be true: `derived_obj == base_obj`
if type(self) is not type(other):
self._throw_comp_exception(other, '==')
return self == other
def op_not_equals(self, other: TYPE_var) -> bool:
if type(self) is not type(other):
self._throw_comp_exception(other, '!=')
return self != other
class MesonInterpreterObject(InterpreterObject):
''' All non-elementary objects and non-object-holders should be derived from this '''
class MutableInterpreterObject:
''' Dummy class to mark the object type as mutable '''
HoldableTypes = (HoldableObject, int, bool, str, list, dict)
TYPE_HoldableTypes = T.Union[TYPE_elementary, HoldableObject]
InterpreterObjectTypeVar = T.TypeVar('InterpreterObjectTypeVar', bound=TYPE_HoldableTypes)
class ObjectHolder(InterpreterObject, T.Generic[InterpreterObjectTypeVar]):
def __init__(self, obj: InterpreterObjectTypeVar, interpreter: 'Interpreter') -> None:
super().__init__(subproject=interpreter.subproject)
# This causes some type checkers to assume that obj is a base
# HoldableObject, not the specialized type, so only do this assert in
# non-type checking situations
if not T.TYPE_CHECKING:
assert isinstance(obj, HoldableTypes), f'This is a bug: Trying to hold object of type `{type(obj).__name__}` that is not in `{HoldableTypes}`'
self.held_object = obj
self.interpreter = interpreter
self.env = self.interpreter.environment
# Hide the object holder abstraction from the user
def display_name(self) -> str:
return type(self.held_object).__name__
# Override default comparison operators for the held object
def op_equals(self, other: TYPE_var) -> bool:
# See the comment from InterpreterObject why we are using `type()` here.
if type(self.held_object) is not type(other):
self._throw_comp_exception(other, '==')
return self.held_object == other
def op_not_equals(self, other: TYPE_var) -> bool:
if type(self.held_object) is not type(other):
self._throw_comp_exception(other, '!=')
return self.held_object != other
def __repr__(self) -> str:
return f'<[{type(self).__name__}] holds [{type(self.held_object).__name__}]: {self.held_object!r}>'
class IterableObject(metaclass=ABCMeta):
'''Base class for all objects that can be iterated over in a foreach loop'''
def iter_tuple_size(self) -> T.Optional[int]:
'''Return the size of the tuple for each iteration. Returns None if only a single value is returned.'''
raise MesonBugException(f'iter_tuple_size not implemented for {self.__class__.__name__}')
def iter_self(self) -> T.Iterator[T.Union[TYPE_var, T.Tuple[TYPE_var, ...]]]:
raise MesonBugException(f'iter not implemented for {self.__class__.__name__}')
def size(self) -> int:
raise MesonBugException(f'size not implemented for {self.__class__.__name__}')
class ContextManagerObject(MesonInterpreterObject, AbstractContextManager):
def __init__(self, subproject: 'SubProject') -> None:
super().__init__(subproject=subproject)