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Diffstat (limited to 'Tools/Scripts/webkitpy/common/checkout/diff_parser.py')
| -rw-r--r-- | Tools/Scripts/webkitpy/common/checkout/diff_parser.py | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/Tools/Scripts/webkitpy/common/checkout/diff_parser.py b/Tools/Scripts/webkitpy/common/checkout/diff_parser.py new file mode 100644 index 0000000..a6ea756 --- /dev/null +++ b/Tools/Scripts/webkitpy/common/checkout/diff_parser.py @@ -0,0 +1,181 @@ +# Copyright (C) 2009 Google Inc. All rights reserved. +# +# 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 +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# 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, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +"""WebKit's Python module for interacting with patches.""" + +import logging +import re + +_log = logging.getLogger("webkitpy.common.checkout.diff_parser") + + +# FIXME: This is broken. We should compile our regexps up-front +# instead of using a custom cache. +_regexp_compile_cache = {} + + +# FIXME: This function should be removed. +def match(pattern, string): + """Matches the string with the pattern, caching the compiled regexp.""" + if not pattern in _regexp_compile_cache: + _regexp_compile_cache[pattern] = re.compile(pattern) + return _regexp_compile_cache[pattern].match(string) + + +# FIXME: This belongs on DiffParser (e.g. as to_svn_diff()). +def git_diff_to_svn_diff(line): + """Converts a git formatted diff line to a svn formatted line. + + Args: + line: A string representing a line of the diff. + """ + # FIXME: This list should be a class member on DiffParser. + # These regexp patterns should be compiled once instead of every time. + conversion_patterns = (("^diff --git \w/(.+) \w/(?P<FilePath>.+)", lambda matched: "Index: " + matched.group('FilePath') + "\n"), + ("^new file.*", lambda matched: "\n"), + ("^index [0-9a-f]{7}\.\.[0-9a-f]{7} [0-9]{6}", lambda matched: "===================================================================\n"), + ("^--- \w/(?P<FilePath>.+)", lambda matched: "--- " + matched.group('FilePath') + "\n"), + ("^\+\+\+ \w/(?P<FilePath>.+)", lambda matched: "+++ " + matched.group('FilePath') + "\n")) + + for pattern, conversion in conversion_patterns: + matched = match(pattern, line) + if matched: + return conversion(matched) + return line + + +# FIXME: This method belongs on DiffParser +def get_diff_converter(first_diff_line): + """Gets a converter function of diff lines. + + Args: + first_diff_line: The first filename line of a diff file. + If this line is git formatted, we'll return a + converter from git to SVN. + """ + if match(r"^diff --git \w/", first_diff_line): + return git_diff_to_svn_diff + return lambda input: input + + +_INITIAL_STATE = 1 +_DECLARED_FILE_PATH = 2 +_PROCESSING_CHUNK = 3 + + +class DiffFile(object): + """Contains the information for one file in a patch. + + The field "lines" is a list which contains tuples in this format: + (deleted_line_number, new_line_number, line_string) + If deleted_line_number is zero, it means this line is newly added. + If new_line_number is zero, it means this line is deleted. + """ + # FIXME: Tuples generally grow into classes. We should consider + # adding a DiffLine object. + + def added_or_modified_line_numbers(self): + # This logic was moved from patchreader.py, but may not be + # the right API for this object long-term. + return [line[1] for line in self.lines if not line[0]] + + def __init__(self, filename): + self.filename = filename + self.lines = [] + + def add_new_line(self, line_number, line): + self.lines.append((0, line_number, line)) + + def add_deleted_line(self, line_number, line): + self.lines.append((line_number, 0, line)) + + def add_unchanged_line(self, deleted_line_number, new_line_number, line): + self.lines.append((deleted_line_number, new_line_number, line)) + + +class DiffParser(object): + """A parser for a patch file. + + The field "files" is a dict whose key is the filename and value is + a DiffFile object. + """ + + # FIXME: This function is way too long and needs to be broken up. + def __init__(self, diff_input): + """Parses a diff. + + Args: + diff_input: An iterable object. + """ + state = _INITIAL_STATE + + self.files = {} + current_file = None + old_diff_line = None + new_diff_line = None + for line in diff_input: + line = line.rstrip("\n") + if state == _INITIAL_STATE: + transform_line = get_diff_converter(line) + line = transform_line(line) + + file_declaration = match(r"^Index: (?P<FilePath>.+)", line) + if file_declaration: + filename = file_declaration.group('FilePath') + current_file = DiffFile(filename) + self.files[filename] = current_file + state = _DECLARED_FILE_PATH + continue + + lines_changed = match(r"^@@ -(?P<OldStartLine>\d+)(,\d+)? \+(?P<NewStartLine>\d+)(,\d+)? @@", line) + if lines_changed: + if state != _DECLARED_FILE_PATH and state != _PROCESSING_CHUNK: + _log.error('Unexpected line change without file path ' + 'declaration: %r' % line) + old_diff_line = int(lines_changed.group('OldStartLine')) + new_diff_line = int(lines_changed.group('NewStartLine')) + state = _PROCESSING_CHUNK + continue + + if state == _PROCESSING_CHUNK: + if line.startswith('+'): + current_file.add_new_line(new_diff_line, line[1:]) + new_diff_line += 1 + elif line.startswith('-'): + current_file.add_deleted_line(old_diff_line, line[1:]) + old_diff_line += 1 + elif line.startswith(' '): + current_file.add_unchanged_line(old_diff_line, new_diff_line, line[1:]) + old_diff_line += 1 + new_diff_line += 1 + elif line == '\\ No newline at end of file': + # Nothing to do. We may still have some added lines. + pass + else: + _log.error('Unexpected diff format when parsing a ' + 'chunk: %r' % line) |