Modify presubmit checks to work on changed lines only.

presubmit_support.py

 #!/usr/bin/python
 # Copyright (c) 2010 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.
 
 """Enables directory-specific presubmit checks to run at upload and/or commit.
 """
 
 __version__ = '1.3.5'
 
@@ skipping 68 matching lines @@
 
 def PromptYesNo(input_stream, output_stream, prompt):
   output_stream.write(prompt)
   response = input_stream.readline().strip().lower()
   return response == 'y' or response == 'yes'
 
 
 def _RightHandSideLinesImpl(affected_files):
   """Implements RightHandSideLines for InputApi and GclChange."""
   for af in affected_files:
-    lines = af.NewContents()
-    line_number = 0
+    lines = af.ChangedContents()
     for line in lines:
-      line_number += 1
-      yield (af, line_number, line)
+      yield (af, line[0], line[1])
 
 
 class OutputApi(object):
   """This class (more like a module) gets passed to presubmit scripts so that
   they can specify various types of results.
   """
   # Method could be a function
   # pylint: disable=R0201
   class PresubmitResult(object):
     """Base class for result objects."""
@@ skipping 77 matching lines @@
   know stuff about the change they're looking at.
   """
   # Method could be a function
   # pylint: disable=R0201
 
   # File extensions that are considered source files from a style guide
   # perspective. Don't modify this list from a presubmit script!
   DEFAULT_WHITE_LIST = (
       # C++ and friends
       r".*\.c$", r".*\.cc$", r".*\.cpp$", r".*\.h$", r".*\.m$", r".*\.mm$",
-      r".*\.inl$", r".*\.asm$", r".*\.hxx$", r".*\.hpp$",
+      r".*\.inl$", r".*\.asm$", r".*\.hxx$", r".*\.hpp$", r".*\.s$", r".*\.S$",
       # Scripts
       r".*\.js$", r".*\.py$", r".*\.sh$", r".*\.rb$", r".*\.pl$", r".*\.pm$",
       # No extension at all, note that ALL CAPS files are black listed in
       # DEFAULT_BLACK_LIST below.
       r"(^|.*?[\\\/])[^.]+$",
       # Other
       r".*\.java$", r".*\.mk$", r".*\.am$",
   )
 
   # Path regexp that should be excluded from being considered containing source
   # files. Don't modify this list from a presubmit script!
   DEFAULT_BLACK_LIST = (
       r".*\bexperimental[\\\/].*",
       r".*\bthird_party[\\\/].*",
       # Output directories (just in case)
       r".*\bDebug[\\\/].*",
       r".*\bRelease[\\\/].*",
       r".*\bxcodebuild[\\\/].*",
       r".*\bsconsbuild[\\\/].*",
       # All caps files like README and LICENCE.
-      r".*\b[A-Z0-9_]+$",
+      r".*\b[A-Z0-9_]{2,}$",
       # SCM (can happen in dual SCM configuration). (Slightly over aggressive)
       r"(|.*[\\\/])\.git[\\\/].*",
       r"(|.*[\\\/])\.svn[\\\/].*",
   )
 
   def __init__(self, change, presubmit_path, is_committing):
     """Builds an InputApi object.
 
     Args:
       change: A presubmit.Change object.
@@ skipping 115 matching lines @@
 
     If white_list or black_list is None, InputApi.DEFAULT_WHITE_LIST
     and InputApi.DEFAULT_BLACK_LIST is used respectively.
 
     The lists will be compiled as regular expression and
     AffectedFile.LocalPath() needs to pass both list.
 
     Note: Copy-paste this function to suit your needs or use a lambda function.
     """
     def Find(affected_file, items):
+      local_path = affected_file.LocalPath()
       for item in items:
-        local_path = affected_file.LocalPath()
         if self.re.match(item, local_path):
           logging.debug("%s matched %s" % (item, local_path))
           return True
       return False
     return (Find(affected_file, white_list or self.DEFAULT_WHITE_LIST) and
             not Find(affected_file, black_list or self.DEFAULT_BLACK_LIST))
 
   def AffectedSourceFiles(self, source_file):
     """Filter the list of AffectedTextFiles by the function source_file.
 
@@ skipping 114 matching lines @@
 
   def OldFileTempPath(self):
     """Returns the path on local disk where the old contents resides.
 
     The old version is the file in depot, i.e. the "left hand side".
     This is a read-only cached copy of the old contents. *DO NOT* try to
     modify this file.
     """
     raise NotImplementedError()  # Implement if/when needed.
 
+  def ChangedContents(self):
+    """Returns a list of tuples (line number, line text) of all new lines.
+
+     This relies on the scm diff output describing each changed code section
+     with a line of the form
+
+     ^@@ <old line num>,<old size> <new line num>,<new size> @@$
+    """
+    new_lines = []
+    line_num = 0
+
+    if self.IsDirectory():
+      return []
+
+    for line in self.GenerateScmDiff().splitlines():
+      m = re.match(r'^@@ [0-9\,\+\-]+ \+([0-9]+)\,[0-9]+ @@', line)
+      if m:
+        line_num = int(m.groups(1)[0])
+        continue
+      if line.startswith('+') and not line.startswith('++'):
+        new_lines.append((line_num, line[1:]))
+      if not line.startswith('-'):
+        line_num += 1
+    return new_lines
+
   def __str__(self):
     return self.LocalPath()
 
+  def GenerateScmDiff(self):
+    raise NotImplementedError()  # Implemented in derived classes.
 
 class SvnAffectedFile(AffectedFile):
   """Representation of a file in a change out of a Subversion checkout."""
   # Method 'NNN' is abstract in class 'NNN' but is not overridden
   # pylint: disable=W0223
 
   def __init__(self, *args, **kwargs):
     AffectedFile.__init__(self, *args, **kwargs)
     self._server_path = None
     self._is_text_file = None
@@ skipping 28 matching lines @@
         # A deleted file is not a text file.
         self._is_text_file = False
       elif self.IsDirectory():
         self._is_text_file = False
       else:
         mime_type = scm.SVN.GetFileProperty(self.AbsoluteLocalPath(),
                                             'svn:mime-type')
         self._is_text_file = (not mime_type or mime_type.startswith('text/'))
     return self._is_text_file
 
+  def GenerateScmDiff(self):
+    return scm.SVN.GenerateDiff(self.AbsoluteLocalPath())
 
 class GitAffectedFile(AffectedFile):
   """Representation of a file in a change out of a git checkout."""
   # Method 'NNN' is abstract in class 'NNN' but is not overridden
   # pylint: disable=W0223
 
   def __init__(self, *args, **kwargs):
     AffectedFile.__init__(self, *args, **kwargs)
     self._server_path = None
     self._is_text_file = None
@@ skipping 25 matching lines @@
       if self.Action() == 'D':
         # A deleted file is not a text file.
         self._is_text_file = False
       elif self.IsDirectory():
         self._is_text_file = False
       else:
         # raise NotImplementedException()  # TODO(maruel) Implement.
         self._is_text_file = os.path.isfile(self.AbsoluteLocalPath())
     return self._is_text_file
 
+  def GenerateScmDiff(self):
+    return scm.GIT.GenerateDiff(self._local_root, files=[self.LocalPath(),])
 
 class Change(object):
   """Describe a change.
 
   Used directly by the presubmit scripts to query the current change being
   tested.
 
   Instance members:
     tags: Dictionnary of KEY=VALUE pairs found in the change description.
     self.KEY: equivalent to tags['KEY']
@@ skipping 538 matching lines @@
                                options.commit,
                                options.verbose,
                                sys.stdout,
                                sys.stdin,
                                options.default_presubmit,
                                options.may_prompt)
 
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv))