WebKitTools/Scripts/check-webkit-style

#!/usr/bin/python
#
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"""Script to run the linter for source code of WebKit."""

import codecs
import os
import os.path
import sys

import modules.cpp_style as cpp_style
from modules.diff_parser import DiffParser
from modules.scm import detect_scm_system


# Override the usage of the lint tool.
cpp_style._USAGE = """
Syntax: %(program_name)s [--verbose=#] [--git-commit=<SingleCommit>] [--output=vs7]
        [--filter=-x,+y,...] [file] ...

  The style guidelines this tries to follow are those in
    http://webkit.org/coding/coding-style.html

  Every problem is given a confidence score from 1-5, with 5 meaning we are
  certain of the problem, and 1 meaning it could be a legitimate construct.
  This will miss some errors, and is not a substitute for a code review.

  To prevent specific lines from being linted, add a '// NOLINT' comment to the
  end of the line.

  Linted extensions are .cpp, .c and .h.  Other file types will be ignored.

  The file parameter is optional and multiple files to scan be passed in.
  Leaving out the file parameter will apply the check to the files changed
  according to the scm system.

  Flags:

    verbose=#
      Specify a number 0-5 to restrict errors to certain verbosity levels.

    git-commit=<SingleCommit>
      Checks the style of everything from the given commit to the local tree.

    output=vs7
      By default, the output is formatted to ease emacs parsing.  Visual Studio
      compatible output (vs7) may also be used.  Other formats are unsupported.

    filter=-x,+y,...
      Specify a comma-separated list of category-filters to apply: only
      error messages whose category names pass the filters will be printed.
      (Category names are printed with the message and look like
      "[whitespace/indent]".)  Filters are evaluated left to right.
      "-FOO" and "FOO" means "do not print categories that start with FOO".
      "+FOO" means "do print categories that start with FOO".

      Examples: --filter=-whitespace,+whitespace/braces
                --filter=whitespace,runtime/printf,+runtime/printf_format
                --filter=-,+build/include_what_you_use

      To see a list of all the categories used in %(program_name)s, pass no arg:
         --filter=
""" % {'program_name': os.path.basename(sys.argv[0])}


def process_patch(patch_string):
    """Does lint on a single patch.

    Args:
      patch_string: A string of a patch.
    """
    patch = DiffParser(patch_string.splitlines())
    for filename, diff in patch.files.iteritems():
        file_extension = os.path.splitext(filename)[1]

        if file_extension in ['.cpp', '.c', '.h']:
            line_numbers = set()

            def error_for_patch(filename, line_number, category, confidence, message):
                """Wrapper function of cpp_style.error for patches.

                This function outputs errors only if the line number
                corresponds to lines which are modified or added.
                """
                if not line_numbers:
                    for line in diff.lines:
                        # When deleted line is not set, it means that
                        # the line is newly added.
                        if not line[0]:
                            line_numbers.add(line[1])

                if line_number in line_numbers:
                    cpp_style.error(filename, line_number, category, confidence, message)

            cpp_style.process_file(filename, error=error_for_patch)


def main():
    cpp_style.use_webkit_styles()

    (files, flags) = cpp_style.parse_arguments(sys.argv[1:], ["git-commit="])

    # Change stderr to write with replacement characters so we don't die
    # if we try to print something containing non-ASCII characters.
    sys.stderr = codecs.StreamReaderWriter(sys.stderr,
                                           codecs.getreader('utf8'),
                                           codecs.getwriter('utf8'),
                                           'replace')

    if files and "--git-commit" in flags:
        sys.stderr.write("ERROR: It is not possible to check files "
                          "and a specific commit at the same time.\n" + cpp_style._USAGE)
        sys.exit(1)

    if files:
        for filename in files:
            cpp_style.process_file(filename)

    else:
        cwd = os.path.abspath('.')
        scm = detect_scm_system(cwd)

        if "--git-commit" in flags:
            commit = flags["--git-commit"]
            if '..' in commit:
                # FIXME: If the range is a "...", the code should find the common ancestor and
                # start there (see git diff --help for information about how ... usually works).
                commit = commit[:commit.find('..')]
                print >> sys.stderr, "Warning: Ranges are not supported for --git-commit. Checking all changes since %s.\n" % commit
            process_patch(scm.create_patch_since_local_commit(commit))
        else:
            process_patch(scm.create_patch())

    sys.stderr.write('Total errors found: %d\n' % cpp_style.error_count())
    sys.exit(cpp_style.error_count() > 0)


if __name__ == "__main__":
    main()