Add pylint to depot_tools.

third_party/pylint/checkers/newstyle.py

+# Copyright (c) 2005-2006 LOGILAB S.A. (Paris, FRANCE).
+# http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+"""check for new / old style related problems
+"""
+
+from logilab import astng
+
+from pylint.interfaces import IASTNGChecker
+from pylint.checkers import BaseChecker
+from pylint.checkers.utils import check_messages
+
+MSGS = {
+    'E1001': ('Use of __slots__ on an old style class',
+              'Used when an old style class uses the __slots__ attribute.'),
+    'E1002': ('Use of super on an old style class',
+              'Used when an old style class uses the super builtin.'),
+    'E1003': ('Bad first argument %r given to super class',
+              'Used when another argument than the current class is given as \
+              first argument of the super builtin.'),
+    'W1001': ('Use of "property" on an old style class',
+              'Used when PyLint detect the use of the builtin "property" \
+              on an old style class while this is relying on new style \
+              classes features'),
+    }
+
+
+class NewStyleConflictChecker(BaseChecker):
+    """checks for usage of new style capabilities on old style classes and
+    other new/old styles conflicts problems                                    
+    * use of property, __slots__, super                                        
+    * "super" usage                                                            
+    """
+    
+    __implements__ = (IASTNGChecker,)
+
+    # configuration section name
+    name = 'newstyle'
+    # messages
+    msgs = MSGS
+    priority = -2
+    # configuration options
+    options = ()
+
+    @check_messages('E1001')
+    def visit_class(self, node):
+        """check __slots__ usage
+        """        
+        if '__slots__' in node and not node.newstyle:
+            self.add_message('E1001', node=node)
+
+    @check_messages('W1001')
+    def visit_callfunc(self, node):
+        """check property usage"""
+        parent = node.parent.frame()
+        if (isinstance(parent, astng.Class) and
+            not parent.newstyle and
+            isinstance(node.func, astng.Name)):
+            name = node.func.name
+            if name == 'property':
+                self.add_message('W1001', node=node)
+
+    @check_messages('E1002', 'E1003')
+    def visit_function(self, node):
+        """check use of super"""
+        # ignore actual functions or method within a new style class
+        if not node.is_method():
+            return
+        klass = node.parent.frame()
+        for stmt in node.nodes_of_class(astng.CallFunc):
+            expr = stmt.func
+            if not isinstance(expr, astng.Getattr):
+                continue
+            call = expr.expr
+            # skip the test if using super
+            if isinstance(call, astng.CallFunc) and \
+               isinstance(call.func, astng.Name) and \
+               call.func.name == 'super':
+                if not klass.newstyle:
+                    # super should not be used on an old style class
+                    self.add_message('E1002', node=node)
+                else:
+                    # super first arg should be the class
+                    try:
+                        supcls = (call.args and call.args[0].infer().next()
+                                  or None)
+                    except astng.InferenceError:
+                        continue
+                    if klass is not supcls:
+                        supcls = getattr(supcls, 'name', supcls)
+                        self.add_message('E1003', node=node, args=supcls)
+
+
+def register(linter):
+    """required method to auto register this checker """
+    linter.register_checker(NewStyleConflictChecker(linter))