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# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
# Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt
from __future__ import annotations
import re
from collections.abc import Generator
from typing import NamedTuple
# Allow stopping after the first semicolon/hash encountered,
# so that an option can be continued with the reasons
# why it is active or disabled.
OPTION_RGX = r"""
(?:^\s*\#.*|\s*| # Comment line, or whitespaces,
\s*\#.*(?=\#.*?\bpylint:)) # or a beginning of an inline comment
# followed by "pylint:" pragma
(\# # Beginning of comment
.*? # Anything (as little as possible)
\bpylint: # pylint word and column
\s* # Any number of whitespaces
([^;#\n]+)) # Anything except semicolon or hash or
# newline (it is the second matched group)
# and end of the first matched group
[;#]{0,1} # From 0 to 1 repetition of semicolon or hash
"""
OPTION_PO = re.compile(OPTION_RGX, re.VERBOSE)
class PragmaRepresenter(NamedTuple):
action: str
messages: list[str]
ATOMIC_KEYWORDS = frozenset(("disable-all", "skip-file"))
MESSAGE_KEYWORDS = frozenset(
("disable-next", "disable-msg", "enable-msg", "disable", "enable")
)
# sorted is necessary because sets are unordered collections and ALL_KEYWORDS
# string should not vary between executions
# reverse is necessary in order to have the longest keywords first, so that, for example,
# 'disable' string should not be matched instead of 'disable-all'
ALL_KEYWORDS = "|".join(
sorted(ATOMIC_KEYWORDS | MESSAGE_KEYWORDS, key=len, reverse=True)
)
TOKEN_SPECIFICATION = [
("KEYWORD", rf"\b({ALL_KEYWORDS:s})\b"),
("MESSAGE_STRING", r"[0-9A-Za-z\-\_]{2,}"), # Identifiers
("ASSIGN", r"="), # Assignment operator
("MESSAGE_NUMBER", r"[CREIWF]{1}\d*"),
]
TOK_REGEX = "|".join(
f"(?P<{token_name:s}>{token_rgx:s})"
for token_name, token_rgx in TOKEN_SPECIFICATION
)
def emit_pragma_representer(action: str, messages: list[str]) -> PragmaRepresenter:
if not messages and action in MESSAGE_KEYWORDS:
raise InvalidPragmaError(
"The keyword is not followed by message identifier", action
)
return PragmaRepresenter(action, messages)
class PragmaParserError(Exception):
"""A class for exceptions thrown by pragma_parser module."""
def __init__(self, message: str, token: str) -> None:
""":args message: explain the reason why the exception has been thrown
:args token: token concerned by the exception.
"""
self.message = message
self.token = token
super().__init__(self.message)
class UnRecognizedOptionError(PragmaParserError):
"""Thrown in case the of a valid but unrecognized option."""
class InvalidPragmaError(PragmaParserError):
"""Thrown in case the pragma is invalid."""
def parse_pragma(pylint_pragma: str) -> Generator[PragmaRepresenter, None, None]:
action: str | None = None
messages: list[str] = []
assignment_required = False
previous_token = ""
for mo in re.finditer(TOK_REGEX, pylint_pragma):
kind = mo.lastgroup
value = mo.group()
if kind == "ASSIGN":
if not assignment_required:
if action:
# A keyword has been found previously but doesn't support assignment
raise UnRecognizedOptionError(
"The keyword doesn't support assignment", action
)
if previous_token:
# Something found previously but not a known keyword
raise UnRecognizedOptionError(
"The keyword is unknown", previous_token
)
# Nothing at all detected before this assignment
raise InvalidPragmaError("Missing keyword before assignment", "")
assignment_required = False
elif assignment_required:
raise InvalidPragmaError(
"The = sign is missing after the keyword", action or ""
)
elif kind == "KEYWORD":
if action:
yield emit_pragma_representer(action, messages)
action = value
messages = []
assignment_required = action in MESSAGE_KEYWORDS
elif kind in {"MESSAGE_STRING", "MESSAGE_NUMBER"}:
messages.append(value)
assignment_required = False
else:
raise RuntimeError("Token not recognized")
previous_token = value
if action:
yield emit_pragma_representer(action, messages)
else:
raise UnRecognizedOptionError("The keyword is unknown", previous_token)
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