printer_protocol.py

###
# Copyright 2022-present MongoDB, Inc.
#
# 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.
###
"""Shim to expose the typing.Protocols defined in stubs/gdb/printing.pyi as concrete classes when
being referenced inside GDB.
"""

import typing

# pylint: disable=protected-access
# pylint: disable=missing-class-docstring
# pylint: disable=too-few-public-methods

if typing.TYPE_CHECKING:
    import gdb._lazy_string
    import gdb.printing

    LazyString = gdb._lazy_string.LazyString
    PrettyPrinterProtocol = gdb.printing._PrettyPrinterProtocol
    SupportsChildren = gdb.printing._SupportsChildren
    SupportsDisplayHint = gdb.printing._SupportsDisplayHint
    SupportsToString = gdb.printing._SupportsToString
else:
    import gdb

    # gdb_pymodule_addobject() isn't called for its LazyString class so we expose the type here
    # ourselves. This attribute won't be used to construct LazyString instances directly. Instead,
    # it'll be used for type checking and satisfying Mypy.
    LazyString = type(gdb.parse_and_eval("(char *) 0").lazy_string(length=0))

    class SupportsChildren(typing.Protocol):
        ...

    class SupportsDisplayHint(typing.Protocol):
        ...

    class SupportsToString(typing.Protocol):
        ...

    class PrettyPrinterProtocol(SupportsToString, SupportsChildren, typing.Protocol):
        ...