tools/checkdeps/java_checker.py

   1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 """Checks Java files for illegal imports."""
   6
   7 import codecs
   8 import os
   9 import re
  10
  11 import results
  12 from rules import Rule
  13
  14
  15 class JavaChecker(object):
  16   """Import checker for Java files.
  17
  18   The CheckFile method uses real filesystem paths, but Java imports work in
  19   terms of package names. To deal with this, we have an extra "prescan" pass
  20   that reads all the .java files and builds a mapping of class name -> filepath.
  21   In CheckFile, we convert each import statement into a real filepath, and check
  22   that against the rules in the DEPS files.
  23
  24   Note that in Java you can always use classes in the same directory without an
  25   explicit import statement, so these imports can't be blocked with DEPS files.
  26   But that shouldn't be a problem, because same-package imports are pretty much
  27   always correct by definition. (If we find a case where this is *not* correct,
  28   it probably means the package is too big and needs to be split up.)
  29
  30   Properties:
  31     _classmap: dict of fully-qualified Java class name -> filepath
  32   """
  33
  34   EXTENSIONS = ['.java']
  35
  36   def __init__(self, base_directory, verbose):
  37     self._base_directory = base_directory
  38     self._verbose = verbose
  39     self._classmap = {}
  40     self._PrescanFiles()
  41
  42   def _PrescanFiles(self):
  43     for root, dirs, files in os.walk(self._base_directory):
  44       # Skip unwanted subdirectories. TODO(husky): it would be better to do
  45       # this via the skip_child_includes flag in DEPS files. Maybe hoist this
  46       # prescan logic into checkdeps.py itself?
  47       for d in dirs:
  48         # Skip hidden directories.
  49         if d.startswith('.'):
  50           dirs.remove(d)
  51         # Skip the "out" directory, as dealing with generated files is awkward.
  52         # We don't want paths like "out/Release/lib.java" in our DEPS files.
  53         # TODO(husky): We need some way of determining the "real" path to
  54         # a generated file -- i.e., where it would be in source control if
  55         # it weren't generated.
  56         if d == 'out':
  57           dirs.remove(d)
  58         # Skip third-party directories.
  59         if d == 'third_party':
  60           dirs.remove(d)
  61       for f in files:
  62         if f.endswith('.java'):
  63           self._PrescanFile(os.path.join(root, f))
  64
  65   def _PrescanFile(self, filepath):
  66     if self._verbose:
  67       print 'Prescanning: ' + filepath
  68     with codecs.open(filepath, encoding='utf-8') as f:
  69       short_class_name, _ = os.path.splitext(os.path.basename(filepath))
  70       for line in f:
  71         for package in re.findall('^package ([\w\.]+);', line):
  72           full_class_name = package + '.' + short_class_name
  73           if full_class_name in self._classmap:
  74             print 'WARNING: multiple definitions of %s:' % full_class_name
  75             print '    ' + filepath
  76             print '    ' + self._classmap[full_class_name]
  77             print
  78           else:
  79             self._classmap[full_class_name] = filepath
  80           return
  81       print 'WARNING: no package definition found in %s' % filepath
  82
  83   def CheckFile(self, rules, filepath):
  84     if self._verbose:
  85       print 'Checking: ' + filepath
  86
  87     dependee_status = results.DependeeStatus(filepath)
  88     with codecs.open(filepath, encoding='utf-8') as f:
  89       for line in f:
  90         for clazz in re.findall('^import\s+(?:static\s+)?([\w\.]+)\s*;', line):
  91           if clazz not in self._classmap:
  92             # Importing a class from outside the Chromium tree. That's fine --
  93             # it's probably a Java or Android system class.
  94             continue
  95           include_path = os.path.relpath(
  96               self._classmap[clazz], self._base_directory)
  97           # Convert Windows paths to Unix style, as used in DEPS files.
  98           include_path = include_path.replace(os.path.sep, '/')
  99           rule = rules.RuleApplyingTo(include_path, filepath)
 100           if rule.allow == Rule.DISALLOW:
 101             dependee_status.AddViolation(
 102                 results.DependencyViolation(include_path, rule, rules))
 103         if '{' in line:
 104           # This is code, so we're finished reading imports for this file.
 105           break
 106
 107     return dependee_status