| # Copyright (c) 2013 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| # Copyright 2008 Google Inc. All Rights Reserved. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| """Utility for parsing patches, originally inspired by rietveld source.""" |
| |
| import re |
| |
| |
| _CHUNK_RE = re.compile(r""" |
| @@ |
| \s+ |
| - |
| (?: (\d+) (?: , (\d+) )?) |
| \s+ |
| \+ |
| (?: (\d+) (?: , (\d+) )?) |
| \s+ |
| @@ |
| """, re.VERBOSE) |
| |
| |
| class PatchParseError(Exception): |
| """Raised on parse errors.""" |
| pass |
| |
| |
| def ParsePatchToLines(lines): |
| """Parses a patch from an iterable type. |
| |
| Args: |
| lines: The lines to parse. |
| |
| Returns: |
| None on error, otherwise a list of 3-tuples: |
| (old_line_no, new_line_no, line) |
| |
| A line number can be None if it doesn't exist in the old/new file. |
| """ |
| # Helper function that matches a hunk header and returns line numbers. |
| def match_hunk_start(line): |
| match = _CHUNK_RE.match(line) |
| if not match: |
| raise PatchParseError(line) |
| return (int(match.groups()[0]), int(match.groups()[2])) |
| |
| iterator = lines.__iter__() |
| try: |
| # Skip leading lines until after we've seen one starting with '+++'. |
| while not iterator.next().startswith('+++'): |
| pass |
| |
| # Parse first hunk header. |
| old_ln, new_ln = match_hunk_start(iterator.next()) |
| except StopIteration: |
| return [] |
| |
| # Process the actual patch lines. |
| result = [] |
| for line in iterator: |
| if line[0] == '@': |
| old_ln, new_ln = match_hunk_start(line) |
| elif line[0] == '-': |
| result.append((old_ln, None, line[1:])) |
| old_ln += 1 |
| elif line[0] == '+': |
| result.append((None, new_ln, line[1:])) |
| new_ln += 1 |
| elif line[0] == ' ': |
| result.append((old_ln, new_ln, line[1:])) |
| old_ln += 1 |
| new_ln += 1 |
| else: |
| raise PatchParseError(line) |
| |
| return result |