import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

tools/check-moz-style/modules/diff_parser.py

@@ -0,0 +1,180 @@
+# 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
+
+
+_regexp_compile_cache = {}
+
+
+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)
+
+
+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.
+    """
+    conversion_patterns = (("^diff --git a/(.+) b/(?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"),
+                           ("^--- a/(?P<FilePath>.+)", lambda matched: "--- " + matched.group('FilePath') + "\n"),
+                           ("^\+\+\+ b/(?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
+
+
+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 a/", 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:
+    """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.
+    """
+
+    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:
+    """A parser for a patch file.
+
+    The field "files" is a dict whose key is the filename and value is
+    a DiffFile object.
+    """
+
+    def __init__(self, diff_input):
+        """Parses a diff.
+
+        Args:
+          diff_input: An iterable object.
+        """
+        state = _INITIAL_STATE
+
+        self.files = {}
+        self.status_line = None
+        self.patch_description = None
+        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)
+
+            comment_line = match(r"^\#", line)
+            if comment_line:
+                continue
+
+            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:
+                    logging.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:
+                    logging.error('Unexpected diff format when parsing a chunk: %r' % line)
+
+            # Patch description
+            if state == _INITIAL_STATE:
+                if not self.status_line:
+                    self.status_line = line
+                else:
+                    if not self.patch_description:
+                        # Skip the first blank line after the patch description
+                        if line != "":
+                            self.patch_description = line
+                    else:
+                        self.patch_description = self.patch_description + "\n" + line