lint_hunks: show style violations in the index
Shows the subset of style violations that intersect with lines modified
in the current index.
Change-Id: I0b51674fd43df118e8bbf55b684a1ca0bd0e1d40
diff --git a/tools/lint-hunks.py b/tools/lint-hunks.py
new file mode 100755
index 0000000..87c7b03
--- /dev/null
+++ b/tools/lint-hunks.py
@@ -0,0 +1,125 @@
+#!/usr/bin/python
+## Copyright (c) 2012 The WebM project authors. All Rights Reserved.
+##
+## Use of this source code is governed by a BSD-style license
+## that can be found in the LICENSE file in the root of the source
+## tree. An additional intellectual property rights grant can be found
+## in the file PATENTS. All contributing project authors may
+## be found in the AUTHORS file in the root of the source tree.
+##
+"""Performs style checking on each diff hunk."""
+import getopt
+import os
+import StringIO
+import subprocess
+import sys
+
+import diff
+
+
+SHORT_OPTIONS = "h"
+LONG_OPTIONS = ["help"]
+
+TOPLEVEL_CMD = ["git", "rev-parse", "--show-toplevel"]
+DIFF_CMD = ["git", "diff-index", "-u", "--cached", "HEAD", "--"]
+SHOW_CMD = ["git", "show"]
+CPPLINT_FILTERS = ["-readability/casting", "-runtime/int"]
+
+
+class Usage(Exception):
+ pass
+
+
+class SubprocessException(Exception):
+ def __init__(self, args):
+ msg = "Failed to execute '%s'"%(" ".join(args))
+ super(SubprocessException, self).__init__(msg)
+
+
+class Subprocess(subprocess.Popen):
+ """Adds the notion of an expected returncode to Popen."""
+
+ def __init__(self, args, expected_returncode=0, **kwargs):
+ self._args = args
+ self._expected_returncode = expected_returncode
+ super(Subprocess, self).__init__(args, **kwargs)
+
+ def communicate(self, *args, **kwargs):
+ result = super(Subprocess, self).communicate(*args, **kwargs)
+ if self._expected_returncode is not None:
+ try:
+ ok = self.returncode in self._expected_returncode
+ except TypeError:
+ ok = self.returncode == self._expected_returncode
+ if not ok:
+ raise SubprocessException(self._args)
+ return result
+
+
+def main(argv=None):
+ if argv is None:
+ argv = sys.argv
+ try:
+ try:
+ opts, _ = getopt.getopt(argv[1:], SHORT_OPTIONS, LONG_OPTIONS)
+ except getopt.error, msg:
+ raise Usage(msg)
+
+ # process options
+ for o, _ in opts:
+ if o in ("-h", "--help"):
+ print __doc__
+ sys.exit(0)
+
+ # Find the fully qualified path to the root of the tree
+ tl = Subprocess(TOPLEVEL_CMD, stdout=subprocess.PIPE)
+ tl = tl.communicate()[0].strip()
+
+ # Build the command line to execute cpplint
+ cpplint_cmd = [os.path.join(tl, "tools", "cpplint.py"),
+ "--filter=" + ",".join(CPPLINT_FILTERS),
+ "-"]
+
+ # Get a list of all affected lines
+ file_affected_line_map = {}
+ p = Subprocess(DIFF_CMD, stdout=subprocess.PIPE)
+ stdout = p.communicate()[0]
+ for hunk in diff.ParseDiffHunks(StringIO.StringIO(stdout)):
+ filename = hunk.right.filename[2:]
+ if filename not in file_affected_line_map:
+ file_affected_line_map[filename] = set()
+ file_affected_line_map[filename].update(hunk.right.delta_line_nums)
+
+ # Run each affected file through cpplint
+ lint_failed = False
+ for filename, affected_lines in file_affected_line_map.iteritems():
+ if filename.split(".")[-1] not in ("c", "h", "cc"):
+ continue
+ show_cmd = SHOW_CMD + [":" + filename]
+ show = Subprocess(show_cmd, stdout=subprocess.PIPE)
+ lint = Subprocess(cpplint_cmd, expected_returncode=(0, 1),
+ stdin=show.stdout, stderr=subprocess.PIPE)
+ lint_out = lint.communicate()[1]
+ if lint.returncode == 1:
+ lint_failed = True
+
+ for line in lint_out.split("\n"):
+ fields = line.split(":")
+ if fields[0] != "-":
+ continue
+ warning_line_num = int(fields[1])
+ if warning_line_num in affected_lines:
+ print "%s:%d:%s"%(filename, warning_line_num,
+ ":".join(fields[2:]))
+
+ # Propagate lint's exit status
+ if lint_failed:
+ return 1
+
+ except Usage, err:
+ print >>sys.stderr, err
+ print >>sys.stderr, "for help use --help"
+ return 2
+
+if __name__ == "__main__":
+ sys.exit(main())
