# Copyright (C) 2009 Google Inc. All rights reserved.

# Copyright (C) 2010 Chris Jerdonek (chris.jerdonek@gmail.com)

# Copyright (C) 2010 ProFUSION embedded systems

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions are

# met:

#

#     * Redistributions of source code must retain the above copyright

# notice, this list of conditions and the following disclaimer.

#     * Redistributions in binary form must reproduce the above

# copyright notice, this list of conditions and the following disclaimer

# in the documentation and/or other materials provided with the

# distribution.

#     * Neither the name of Google Inc. nor the names of its

# contributors may be used to endorse or promote products derived from

# this software without specific prior written permission.

#

# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

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# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

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"""Front end of some style-checker modules."""

import logging

import os.path

import sys

from checkers.common import categories as CommonCategories

from checkers.common import CarriageReturnChecker

from checkers.cpp import CppChecker

from checkers.python import PythonChecker

from checkers.text import TextChecker

from error_handlers import DefaultStyleErrorHandler

from filter import FilterConfiguration

from optparser import ArgumentParser

from optparser import DefaultCommandOptionValues

from webkitpy.style_references import configure_logging as _configure_logging

_log = logging.getLogger("webkitpy.style.checker")

# These are default option values for the command-line option parser.

_DEFAULT_MIN_CONFIDENCE = 1

_DEFAULT_OUTPUT_FORMAT = 'emacs'

# FIXME: For style categories we will never want to have, remove them.

#        For categories for which we want to have similar functionality,

#        modify the implementation and enable them.

#

# Throughout this module, we use "filter rule" rather than "filter"

# for an individual boolean filter flag like "+foo".  This allows us to

# reserve "filter" for what one gets by collectively applying all of

# the filter rules.

#

# The base filter rules are the filter rules that begin the list of

# filter rules used to check style.  For example, these rules precede

# any user-specified filter rules.  Since by default all categories are

# checked, this list should normally include only rules that begin

# with a "-" sign.

_BASE_FILTER_RULES = [

    '-build/endif_comment',

    '-build/include_what_you_use',  # <string> for std::string

    '-build/storage_class',  # const static

    '-legal/copyright',

    '-readability/multiline_comment',

    '-readability/braces',  # int foo() {};

    '-readability/fn_size',

    '-readability/casting',

    '-readability/function',

    '-runtime/arrays',  # variable length array

    '-runtime/casting',

    '-runtime/sizeof',

    '-runtime/explicit',  # explicit

    '-runtime/virtual',  # virtual dtor

    '-runtime/printf',

    '-runtime/threadsafe_fn',

    '-runtime/rtti',

    '-whitespace/blank_line',

    '-whitespace/end_of_line',

    '-whitespace/labels',

    # List Python pep8 categories last.

    #

    # Because much of WebKit's Python code base does not abide by the

    # PEP8 79 character limit, we ignore the 79-character-limit category

    # pep8/E501 for now.

    #

    # FIXME: Consider bringing WebKit's Python code base into conformance

    #        with the 79 character limit, or some higher limit that is

    #        agreeable to the WebKit project.

    '-pep8/E501',

    ]

# The path-specific filter rules.

#

# This list is order sensitive.  Only the first path substring match

# is used.  See the FilterConfiguration documentation in filter.py

# for more information on this list.

#

# Each string appearing in this nested list should have at least

# one associated unit test assertion.  These assertions are located,

# for example, in the test_path_rules_specifier() unit test method of

# checker_unittest.py.

_PATH_RULES_SPECIFIER = [

    # Files in these directories are consumers of the WebKit

    # API and therefore do not follow the same header including

    # discipline as WebCore.

    (["WebKitTools/WebKitAPITest/",

      "WebKit/qt/QGVLauncher/"],

     ["-build/include",

      "-readability/streams"]),

    ([# The EFL APIs use EFL naming style, which includes

      # both lower-cased and camel-cased, underscore-sparated

      # values.

      "WebKit/efl/ewk/",

      # There is no clean way to avoid "yy_*" names used by flex.

      "WebCore/css/CSSParser.cpp",

      # There is no clean way to avoid "xxx_data" methods inside

      # Qt's autotests since they are called automatically by the

      # QtTest module.

      "WebKit/qt/tests/",

      "JavaScriptCore/qt/tests"],

     ["-readability/naming"]),

    ([# The GTK+ APIs use GTK+ naming style, which includes

      # lower-cased, underscore-separated values.

      # Also, GTK+ allows the use of NULL.

      "WebKit/gtk/webkit/",

      "WebKitTools/DumpRenderTree/gtk/"],

     ["-readability/naming",

      "-readability/null"]),

    ([# Header files in ForwardingHeaders have no header guards or

      # exceptional header guards (e.g., WebCore_FWD_Debugger_h).

      "/ForwardingHeaders/"],

     ["-build/header_guard"]),

    # For third-party Python code, keep only the following checks--

    #

    #   No tabs: to avoid having to set the SVN allow-tabs property.

    #   No trailing white space: since this is easy to correct.

    #   No carriage-return line endings: since this is easy to correct.

    #

    (["webkitpy/thirdparty/"],

     ["-",

      "+pep8/W191",  # Tabs

      "+pep8/W291",  # Trailing white space

      "+whitespace/carriage_return"]),

]

_CPP_FILE_EXTENSIONS = [

    'c',

    'cpp',

    'h',

    ]

_PYTHON_FILE_EXTENSION = 'py'

# FIXME: Include 'vcproj' files as text files after creating a mechanism

#        for exempting them from the carriage-return checker (since they

#        are Windows-only files).

_TEXT_FILE_EXTENSIONS = [

    'ac',

    'cc',

    'cgi',

    'css',

    'exp',

    'flex',

    'gyp',

    'gypi',

    'html',

    'idl',

    'in',

    'js',

    'mm',

    'php',

    'pl',

    'pm',

    'pri',

    'pro',

    'rb',

    'sh',

    'txt',

#   'vcproj',  # See FIXME above.

    'wm',

    'xhtml',

    'y',

    ]

# Files to skip that are less obvious.

#

# Some files should be skipped when checking style. For example,

# WebKit maintains some files in Mozilla style on purpose to ease

# future merges.

_SKIPPED_FILES_WITH_WARNING = [

    # The Qt API and tests do not follow WebKit style.

    # They follow Qt style. :)

    "gtk2drawing.c", # WebCore/platform/gtk/gtk2drawing.c

    "gtkdrawing.h", # WebCore/platform/gtk/gtkdrawing.h

    "JavaScriptCore/qt/api/",

    "WebKit/gtk/tests/",

    "WebKit/qt/Api/",

    "WebKit/qt/tests/",

    "WebKit/qt/examples/",

    ]

# Files to skip that are more common or obvious.

#

# This list should be in addition to files with FileType.NONE.  Files

# with FileType.NONE are automatically skipped without warning.

_SKIPPED_FILES_WITHOUT_WARNING = [

    "LayoutTests/",

    ]

# The maximum number of errors to report per file, per category.

# If a category is not a key, then it has no maximum.

_MAX_REPORTS_PER_CATEGORY = {

    "whitespace/carriage_return": 1

}

def _all_categories():

    """Return the set of all categories used by check-webkit-style."""

    # Take the union across all checkers.

    categories = CommonCategories.union(CppChecker.categories)

    # FIXME: Consider adding all of the pep8 categories.  Since they

    #        are not too meaningful for documentation purposes, for

    #        now we add only the categories needed for the unit tests

    #        (which validate the consistency of the configuration

    #        settings against the known categories, etc).

    categories = categories.union(["pep8/W191", "pep8/W291", "pep8/E501"])

    return categories

def _check_webkit_style_defaults():

    """Return the default command-line options for check-webkit-style."""

    return DefaultCommandOptionValues(min_confidence=_DEFAULT_MIN_CONFIDENCE,

                                      output_format=_DEFAULT_OUTPUT_FORMAT)

# This function assists in optparser not having to import from checker.

def check_webkit_style_parser():

    all_categories = _all_categories()

    default_options = _check_webkit_style_defaults()

    return ArgumentParser(all_categories=all_categories,

                          base_filter_rules=_BASE_FILTER_RULES,

                          default_options=default_options)

def check_webkit_style_configuration(options):

    """Return a StyleProcessorConfiguration instance for check-webkit-style.

    Args:

      options: A CommandOptionValues instance.

    """

    filter_configuration = FilterConfiguration(

                               base_rules=_BASE_FILTER_RULES,

                               path_specific=_PATH_RULES_SPECIFIER,

                               user_rules=options.filter_rules)

    return StyleProcessorConfiguration(filter_configuration=filter_configuration,

               max_reports_per_category=_MAX_REPORTS_PER_CATEGORY,

               min_confidence=options.min_confidence,

               output_format=options.output_format,

               stderr_write=sys.stderr.write)

def _create_log_handlers(stream):

    """Create and return a default list of logging.Handler instances.

    Format WARNING messages and above to display the logging level, and

    messages strictly below WARNING not to display it.

    Args:

      stream: See the configure_logging() docstring.

    """

    # Handles logging.WARNING and above.

    error_handler = logging.StreamHandler(stream)

    error_handler.setLevel(logging.WARNING)

    formatter = logging.Formatter("%(levelname)s: %(message)s")

    error_handler.setFormatter(formatter)

    # Create a logging.Filter instance that only accepts messages

    # below WARNING (i.e. filters out anything WARNING or above).

    non_error_filter = logging.Filter()

    # The filter method accepts a logging.LogRecord instance.

    non_error_filter.filter = lambda record: record.levelno < logging.WARNING

    non_error_handler = logging.StreamHandler(stream)

    non_error_handler.addFilter(non_error_filter)

    formatter = logging.Formatter("%(message)s")

    non_error_handler.setFormatter(formatter)

    return [error_handler, non_error_handler]

def _create_debug_log_handlers(stream):

    """Create and return a list of logging.Handler instances for debugging.

    Args:

      stream: See the configure_logging() docstring.

    """

    handler = logging.StreamHandler(stream)

    formatter = logging.Formatter("%(name)s: %(levelname)-8s %(message)s")

    handler.setFormatter(formatter)

    return [handler]

def configure_logging(stream, logger=None, is_verbose=False):

    """Configure logging, and return the list of handlers added.

    Returns:

      A list of references to the logging handlers added to the root

      logger.  This allows the caller to later remove the handlers

      using logger.removeHandler.  This is useful primarily during unit

      testing where the caller may want to configure logging temporarily

      and then undo the configuring.

    Args:

      stream: A file-like object to which to log.  The stream must

              define an "encoding" data attribute, or else logging

              raises an error.

      logger: A logging.logger instance to configure.  This parameter

              should be used only in unit tests.  Defaults to the

              root logger.

      is_verbose: A boolean value of whether logging should be verbose.

    """

    # If the stream does not define an "encoding" data attribute, the

    # logging module can throw an error like the following:

    #

    # Traceback (most recent call last):

    #   File "/System/Library/Frameworks/Python.framework/Versions/2.6/...

    #         lib/python2.6/logging/__init__.py", line 761, in emit

    #     self.stream.write(fs % msg.encode(self.stream.encoding))

    # LookupError: unknown encoding: unknown

    if logger is None:

        logger = logging.getLogger()

    if is_verbose:

        logging_level = logging.DEBUG

        handlers = _create_debug_log_handlers(stream)

    else:

        logging_level = logging.INFO

        handlers = _create_log_handlers(stream)

    handlers = _configure_logging(logging_level=logging_level, logger=logger,

                                  handlers=handlers)

    return handlers

# Enum-like idiom

class FileType:

    NONE = 0  # FileType.NONE evaluates to False.

    # Alphabetize remaining types

    CPP = 1

    PYTHON = 2

    TEXT = 3

class CheckerDispatcher(object):

    """Supports determining whether and how to check style, based on path."""

    def _file_extension(self, file_path):

        """Return the file extension without the leading dot."""

        return os.path.splitext(file_path)[1].lstrip(".")

    def should_skip_with_warning(self, file_path):

        """Return whether the given file should be skipped with a warning."""

        for skipped_file in _SKIPPED_FILES_WITH_WARNING:

            if file_path.find(skipped_file) >= 0:

                return True

        return False

    def should_skip_without_warning(self, file_path):

        """Return whether the given file should be skipped without a warning."""

        if not self._file_type(file_path):  # FileType.NONE.

            return True

        # Since "LayoutTests" is in _SKIPPED_FILES_WITHOUT_WARNING, make

        # an exception to prevent files like "LayoutTests/ChangeLog" and

        # "LayoutTests/ChangeLog-2009-06-16" from being skipped.

        #

        # FIXME: Figure out a good way to avoid having to add special logic

        #        for this special case.

        if os.path.basename(file_path).startswith('ChangeLog'):

            return False

        for skipped_file in _SKIPPED_FILES_WITHOUT_WARNING:

            if file_path.find(skipped_file) >= 0:

                return True

        return False

    def _file_type(self, file_path):

        """Return the file type corresponding to the given file."""

        file_extension = self._file_extension(file_path)

        if (file_extension in _CPP_FILE_EXTENSIONS) or (file_path == '-'):

            # FIXME: Do something about the comment below and the issue it

            #        raises since cpp_style already relies on the extension.

            #

            # Treat stdin as C++. Since the extension is unknown when

            # reading from stdin, cpp_style tests should not rely on

            # the extension.

            return FileType.CPP

        elif file_extension == _PYTHON_FILE_EXTENSION:

            return FileType.PYTHON

        elif (os.path.basename(file_path).startswith('ChangeLog') or

              (not file_extension and "WebKitTools/Scripts/" in file_path) or

              file_extension in _TEXT_FILE_EXTENSIONS):

            return FileType.TEXT

        else:

            return FileType.NONE

    def _create_checker(self, file_type, file_path, handle_style_error,

                        min_confidence):

        """Instantiate and return a style checker based on file type."""

        if file_type == FileType.NONE:

            checker = None

        elif file_type == FileType.CPP:

            file_extension = self._file_extension(file_path)

            checker = CppChecker(file_path, file_extension,

                                 handle_style_error, min_confidence)

        elif file_type == FileType.PYTHON:

            checker = PythonChecker(file_path, handle_style_error)

        elif file_type == FileType.TEXT:

            checker = TextChecker(file_path, handle_style_error)

        else:

            raise ValueError('Invalid file type "%(file_type)s": the only valid file types '

                             "are %(NONE)s, %(CPP)s, and %(TEXT)s."

                             % {"file_type": file_type,

                                "NONE": FileType.NONE,

                                "CPP": FileType.CPP,

                                "TEXT": FileType.TEXT})

        return checker

    def dispatch(self, file_path, handle_style_error, min_confidence):

        """Instantiate and return a style checker based on file path."""

        file_type = self._file_type(file_path)

        checker = self._create_checker(file_type,

                                       file_path,

                                       handle_style_error,

                                       min_confidence)

        return checker

# FIXME: Remove the stderr_write attribute from this class and replace

#        its use with calls to a logging module logger.

class StyleProcessorConfiguration(object):

    """Stores configuration values for the StyleProcessor class.

    Attributes:

      min_confidence: An integer between 1 and 5 inclusive that is the

                      minimum confidence level of style errors to report.

      max_reports_per_category: The maximum number of errors to report

                                per category, per file.

      stderr_write: A function that takes a string as a parameter and

                    serves as stderr.write.

    """

    def __init__(self,

                 filter_configuration,

                 max_reports_per_category,

                 min_confidence,

                 output_format,

                 stderr_write):

        """Create a StyleProcessorConfiguration instance.

        Args:

          filter_configuration: A FilterConfiguration instance.  The default

                                is the "empty" filter configuration, which

                                means that all errors should be checked.

          max_reports_per_category: The maximum number of errors to report

                                    per category, per file.

          min_confidence: An integer between 1 and 5 inclusive that is the

                          minimum confidence level of style errors to report.

                          The default is 1, which reports all style errors.

          output_format: A string that is the output format.  The supported

                         output formats are "emacs" which emacs can parse

                         and "vs7" which Microsoft Visual Studio 7 can parse.

          stderr_write: A function that takes a string as a parameter and

                        serves as stderr.write.

        """

        self._filter_configuration = filter_configuration

        self._output_format = output_format

        self.max_reports_per_category = max_reports_per_category

        self.min_confidence = min_confidence

        self.stderr_write = stderr_write

    def is_reportable(self, category, confidence_in_error, file_path):

        """Return whether an error is reportable.

        An error is reportable if both the confidence in the error is

        at least the minimum confidence level and the current filter

        says the category should be checked for the given path.

        Args:

          category: A string that is a style category.