This patch is an attempt to completely remove the need for all Google-internal patches

done to pylint.

Currently, we have to modify pylint in two places:

* Default plugin loading:
  Due to the way Python applications are deployed, the import magic in
  checkers.package_load does not work and needs to be replaced. Placing the
  calls in an overridable methods allows us to modify the behavior in our own
  linter class
* Special reporter:
  We use a custom reporter. It can be passed to Run using the reporter argument,
  but creating in the initializer allows for other reporters to be added to
  REPORTER_OPT_MAP, which is a more general solution and might also benefit others.

These changes do not add any value to upstream pylint per se, but are not intrusive
and would help us minimize the maintenance burden when upgrading to a new pylint
upstream version, freeing up resources for more important work on pylint.

1 files changed, 67 insertions, 62 deletions

diff --git a/lint.py b/lint.py
index d11d716..48ebdf2 100644
--- a/lint.py
+++ b/lint.py
@@ -140,84 +140,86 @@ class PyLinter(OptionsManagerMixIn, MessagesHandlerMixIn, ReportsHandlerMixIn,
     msgs = MSGS
     may_be_disabled = False
 
-    options = (('ignore',
-                {'type' : 'csv', 'metavar' : '<file>[,<file>...]',
-                 'dest' : 'black_list', 'default' : ('CVS',),
-                 'help' : 'Add files or directories to the blacklist. \
+    @staticmethod
+    def make_options():
+        return (('ignore',
+                 {'type' : 'csv', 'metavar' : '<file>[,<file>...]',
+                  'dest' : 'black_list', 'default' : ('CVS',),
+                  'help' : 'Add files or directories to the blacklist. \
 They should be base names, not paths.'}),
-               ('persistent',
-                {'default': True, 'type' : 'yn', 'metavar' : '<y_or_n>',
-                 'level': 1,
-                 'help' : 'Pickle collected data for later comparisons.'}),
-
-               ('load-plugins',
-                {'type' : 'csv', 'metavar' : '<modules>', 'default' : (),
-                 'level': 1,
-                 'help' : 'List of plugins (as comma separated values of \
+                ('persistent',
+                 {'default': True, 'type' : 'yn', 'metavar' : '<y_or_n>',
+                  'level': 1,
+                  'help' : 'Pickle collected data for later comparisons.'}),
+
+                ('load-plugins',
+                 {'type' : 'csv', 'metavar' : '<modules>', 'default' : (),
+                  'level': 1,
+                  'help' : 'List of plugins (as comma separated values of \
 python modules names) to load, usually to register additional checkers.'}),
 
-               ('output-format',
-                {'default': 'text', 'type': 'choice', 'metavar' : '<format>',
-                 'choices': ('text', 'parseable', 'msvs', 'colorized', 'html'),
-                 'short': 'f',
-                 'group': 'Reports',
-                 'help' : 'Set the output format. Available formats are text,\
+                ('output-format',
+                 {'default': 'text', 'type': 'choice', 'metavar' : '<format>',
+                  'choices': REPORTER_OPT_MAP.keys(),
+                  'short': 'f',
+                  'group': 'Reports',
+                  'help' : 'Set the output format. Available formats are text,\
                  parseable, colorized, msvs (visual studio) and html'}),
 
-               ('include-ids',
-                {'type' : 'yn', 'metavar' : '<y_or_n>', 'default' : 0,
-                 'short': 'i',
-                 'group': 'Reports',
-                 'help' : 'Include message\'s id in output'}),
+                ('include-ids',
+                 {'type' : 'yn', 'metavar' : '<y_or_n>', 'default' : 0,
+                  'short': 'i',
+                  'group': 'Reports',
+                  'help' : 'Include message\'s id in output'}),
 
-               ('files-output',
-                {'default': 0, 'type' : 'yn', 'metavar' : '<y_or_n>',
-                 'group': 'Reports', 'level': 1,
-                 'help' : 'Put messages in a separate file for each module / \
+                ('files-output',
+                 {'default': 0, 'type' : 'yn', 'metavar' : '<y_or_n>',
+                  'group': 'Reports', 'level': 1,
+                  'help' : 'Put messages in a separate file for each module / \
 package specified on the command line instead of printing them on stdout. \
 Reports (if any) will be written in a file name "pylint_global.[txt|html]".'}),
 
-               ('reports',
-                {'default': 1, 'type' : 'yn', 'metavar' : '<y_or_n>',
-                 'short': 'r',
-                 'group': 'Reports',
-                 'help' : 'Tells whether to display a full report or only the\
+                ('reports',
+                 {'default': 1, 'type' : 'yn', 'metavar' : '<y_or_n>',
+                  'short': 'r',
+                  'group': 'Reports',
+                  'help' : 'Tells whether to display a full report or only the\
  messages'}),
 
-               ('evaluation',
-                {'type' : 'string', 'metavar' : '<python_expression>',
-                 'group': 'Reports', 'level': 1,
-                 'default': '10.0 - ((float(5 * error + warning + refactor + \
+                ('evaluation',
+                 {'type' : 'string', 'metavar' : '<python_expression>',
+                  'group': 'Reports', 'level': 1,
+                  'default': '10.0 - ((float(5 * error + warning + refactor + \
 convention) / statement) * 10)',
-                 'help' : 'Python expression which should return a note less \
+                  'help' : 'Python expression which should return a note less \
 than 10 (10 is the highest note). You have access to the variables errors \
 warning, statement which respectively contain the number of errors / warnings\
  messages and the total number of statements analyzed. This is used by the \
  global evaluation report (RP0004).'}),
 
-               ('comment',
-                {'default': 0, 'type' : 'yn', 'metavar' : '<y_or_n>',
-                 'group': 'Reports', 'level': 1,
-                 'help' : 'Add a comment according to your evaluation note. \
+                ('comment',
+                 {'default': 0, 'type' : 'yn', 'metavar' : '<y_or_n>',
+                  'group': 'Reports', 'level': 1,
+                  'help' : 'Add a comment according to your evaluation note. \
 This is used by the global evaluation report (RP0004).'}),
 
-               ('enable',
-                {'type' : 'csv', 'metavar': '<msg ids>',
-                 'short': 'e',
-                 'group': 'Messages control',
-                 'help' : 'Enable the message, report, category or checker with the '
-                 'given id(s). You can either give multiple identifier '
-                 'separated by comma (,) or put this option multiple time.'}),
-
-               ('disable',
-                {'type' : 'csv', 'metavar': '<msg ids>',
-                 'short': 'd',
-                 'group': 'Messages control',
-                 'help' : 'Disable the message, report, category or checker '
-                 'with the given id(s). You can either give multiple identifier'
-                 ' separated by comma (,) or put this option multiple time '
-                 '(only on the command line, not in the configuration file '
-                 'where it should appear only once).'}),
+                ('enable',
+                 {'type' : 'csv', 'metavar': '<msg ids>',
+                  'short': 'e',
+                  'group': 'Messages control',
+                  'help' : 'Enable the message, report, category or checker with the '
+                  'given id(s). You can either give multiple identifier '
+                  'separated by comma (,) or put this option multiple time.'}),
+
+                ('disable',
+                 {'type' : 'csv', 'metavar': '<msg ids>',
+                  'short': 'd',
+                  'group': 'Messages control',
+                  'help' : 'Disable the message, report, category or checker '
+                  'with the given id(s). You can either give multiple identifier'
+                  ' separated by comma (,) or put this option multiple time '
+                  '(only on the command line, not in the configuration file '
+                  'where it should appear only once).'}),
                )
 
     option_groups = (
@@ -240,7 +242,7 @@ This is used by the global evaluation report (RP0004).'}),
         self.current_file = None
         self.stats = None
         # init options
-        self.options = options + PyLinter.options
+        self.options = options + PyLinter.make_options()
         self.option_groups = option_groups + PyLinter.option_groups
         self._options_methods = {
             'enable': self.enable,
@@ -270,6 +272,10 @@ This is used by the global evaluation report (RP0004).'}),
         self.load_provider_defaults()
         self.set_reporter(reporter or TextReporter(sys.stdout))
 
+    def load_default_plugins(self):
+        from pylint import checkers
+        checkers.initialize(self)
+
     def load_plugin_modules(self, modnames):
         """take a list of module names which are pylint plugins and load
         and register them
@@ -802,8 +808,7 @@ are done by default'''}),
             ), option_groups=self.option_groups,
                reporter=reporter, pylintrc=self._rcfile)
         # register standard checkers
-        from pylint import checkers
-        checkers.initialize(linter)
+        linter.load_default_plugins()
         # load command line plugins
         linter.load_plugin_modules(self._plugins)
         # add some help section