pylint/checkers/misc.py

# Copyright (c) 2006, 2009-2013 LOGILAB S.A. (Paris, FRANCE) <contact@logilab.fr>
# Copyright (c) 2012-2014 Google, Inc.
# Copyright (c) 2014-2020 Claudiu Popa <pcmanticore@gmail.com>
# Copyright (c) 2014 Brett Cannon <brett@python.org>
# Copyright (c) 2014 Alexandru Coman <fcoman@bitdefender.com>
# Copyright (c) 2014 Arun Persaud <arun@nubati.net>
# Copyright (c) 2015 Ionel Cristian Maries <contact@ionelmc.ro>
# Copyright (c) 2016 Łukasz Rogalski <rogalski.91@gmail.com>
# Copyright (c) 2016 glegoux <gilles.legoux@gmail.com>
# Copyright (c) 2017-2020 hippo91 <guillaume.peillex@gmail.com>
# Copyright (c) 2017 Mikhail Fesenko <proggga@gmail.com>
# Copyright (c) 2018 Rogalski, Lukasz <lukasz.rogalski@intel.com>
# Copyright (c) 2018 Lucas Cimon <lucas.cimon@gmail.com>
# Copyright (c) 2018 Ville Skyttä <ville.skytta@iki.fi>
# Copyright (c) 2019-2021 Pierre Sassoulas <pierre.sassoulas@gmail.com>
# Copyright (c) 2020 wtracy <afishionado@gmail.com>
# Copyright (c) 2020 Anthony Sottile <asottile@umich.edu>
# Copyright (c) 2020 Benny <benny.mueller91@gmail.com>
# Copyright (c) 2021 Marc Mueller <30130371+cdce8p@users.noreply.github.com>
# Copyright (c) 2021 Konstantina Saketou <56515303+ksaketou@users.noreply.github.com>

# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/master/LICENSE


"""Check source code is ascii only or has an encoding declaration (PEP 263)"""

import re
import tokenize

from pylint.checkers import BaseChecker
from pylint.interfaces import IRawChecker, ITokenChecker
from pylint.message import MessagesHandlerMixIn
from pylint.utils.pragma_parser import OPTION_PO, PragmaParserError, parse_pragma


class ByIdManagedMessagesChecker(BaseChecker):

    """Checks for messages that are enabled or disabled by id instead of symbol."""

    __implements__ = IRawChecker
    name = "miscellaneous"
    msgs = {
        "I0023": (
            "%s",
            "use-symbolic-message-instead",
            "Used when a message is enabled or disabled by id.",
        )
    }
    options = ()

    def process_module(self, module):
        """Inspect the source file to find messages activated or deactivated by id."""
        managed_msgs = MessagesHandlerMixIn.get_by_id_managed_msgs()
        for (mod_name, msgid, symbol, lineno, is_disabled) in managed_msgs:
            if mod_name == module.name:
                verb = "disable" if is_disabled else "enable"
                txt = f"'{msgid}' is cryptic: use '# pylint: {verb}={symbol}' instead"
                self.add_message("use-symbolic-message-instead", line=lineno, args=txt)
        MessagesHandlerMixIn.clear_by_id_managed_msgs()


class EncodingChecker(BaseChecker):

    """checks for:
    * warning notes in the code like FIXME, XXX
    * encoding issues.
    """

    __implements__ = (IRawChecker, ITokenChecker)

    # configuration section name
    name = "miscellaneous"
    msgs = {
        "W0511": (
            "%s",
            "fixme",
            "Used when a warning note as FIXME or XXX is detected.",
        )
    }

    options = (
        (
            "notes",
            {
                "type": "csv",
                "metavar": "<comma separated values>",
                "default": ("FIXME", "XXX", "TODO"),
                "help": (
                    "List of note tags to take in consideration, "
                    "separated by a comma."
                ),
            },
        ),
        (
            "notes-rgx",
            {
                "type": "string",
                "metavar": "<regexp>",
                "help": "Regular expression of note tags to take in consideration.",
            },
        ),
    )

    def open(self):
        super().open()

        notes = "|".join(re.escape(note) for note in self.config.notes)
        if self.config.notes_rgx:
            regex_string = fr"#\s*({notes}|{self.config.notes_rgx})\b"
        else:
            regex_string = r"#\s*(%s)\b" % (notes)

        self._fixme_pattern = re.compile(regex_string, re.I)

    def _check_encoding(self, lineno, line, file_encoding):
        try:
            return line.decode(file_encoding)
        except UnicodeDecodeError:
            pass
        except LookupError:
            if line.startswith("#") and "coding" in line and file_encoding in line:
                msg = f"Cannot decode using encoding '{file_encoding}', bad encoding"
                self.add_message("syntax-error", line=lineno, args=msg)
        return None

    def process_module(self, module):
        """inspect the source file to find encoding problem"""
        if module.file_encoding:
            encoding = module.file_encoding
        else:
            encoding = "ascii"

        with module.stream() as stream:
            for lineno, line in enumerate(stream):
                self._check_encoding(lineno + 1, line, encoding)

    def process_tokens(self, tokens):
        """inspect the source to find fixme problems"""
        if not self.config.notes:
            return
        comments = (
            token_info for token_info in tokens if token_info.type == tokenize.COMMENT
        )
        for comment in comments:
            comment_text = comment.string[1:].lstrip()  # trim '#' and whitespaces

            # handle pylint disable clauses
            disable_option_match = OPTION_PO.search(comment_text)
            if disable_option_match:
                try:
                    values = []
                    try:
                        for pragma_repr in (
                            p_rep
                            for p_rep in parse_pragma(disable_option_match.group(2))
                            if p_rep.action == "disable"
                        ):
                            values.extend(pragma_repr.messages)
                    except PragmaParserError:
                        # Printing useful information dealing with this error is done in the lint package
                        pass
                    if set(values) & set(self.config.notes):
                        continue
                except ValueError:
                    self.add_message(
                        "bad-inline-option",
                        args=disable_option_match.group(1).strip(),
                        line=comment.start[0],
                    )
                    continue

            # emit warnings if necessary
            match = self._fixme_pattern.search("#" + comment_text.lower())
            if match:
                self.add_message(
                    "fixme",
                    col_offset=comment.start[1] + 1,
                    args=comment_text,
                    line=comment.start[0],
                )


def register(linter):
    """required method to auto register this checker"""
    linter.register_checker(EncodingChecker(linter))
    linter.register_checker(ByIdManagedMessagesChecker(linter))