Merged in PCManticore/pylint/catch (pull request #47)

Check for non-exception classes inside except clauses.

4 files changed, 63 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index d3bb1ba..397822b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,7 +1,11 @@
 ChangeLog for Pylint
 ====================
 
+--
+    * Check for non-exception classes inside an except clause
+
 2013-08-06  --  1.0.0
+
     * Add check for the use of 'exec' function
 
     * New --msg-template option to control output, deprecating "msvc" and
@@ -108,7 +112,6 @@ ChangeLog for Pylint
       modules
 
 
-
 2013-04-25  --  0.28.0
     * bitbucket #1: fix "dictionary changed size during iteration" crash
 
diff --git a/checkers/exceptions.py b/checkers/exceptions.py
index eb82d0d..8ac00a5 100644
--- a/checkers/exceptions.py
+++ b/checkers/exceptions.py
@@ -46,7 +46,11 @@ MSGS = {
               'notimplemented-raised',
               'Used when NotImplemented is raised instead of \
               NotImplementedError'),
-
+    'E0712': ('Catching an exception which doesn\'t inherit from BaseException: %s',
+              'catching-non-exception',
+              'Used when a class which doesn\'t inherit from \
+               BaseException is used as an exception in an except clause.'),
+    
     'W0701': ('Raising a string exception',
               'raising-string',
               'Used when a string exception is raised.'),
@@ -160,13 +164,14 @@ class ExceptionsChecker(BaseChecker):
             value_found = False
         return value_found
 
-
     @check_messages('W0712')
     def visit_excepthandler(self, node):
         """Visit an except handler block and check for exception unpacking."""
         if isinstance(node.name, (astroid.Tuple, astroid.List)):
             self.add_message('W0712', node=node)
-    @check_messages('W0702', 'W0703', 'W0704', 'W0711', 'E0701')
+
+
+    @check_messages('W0702', 'W0703', 'W0704', 'W0711', 'E0701', 'catching-non-exception')
     def visit_tryexcept(self, node):
         """check for empty except"""
         exceptions_classes = []
@@ -206,6 +211,13 @@ class ExceptionsChecker(BaseChecker):
                         and exc.root().name == EXCEPTIONS_MODULE
                         and nb_handlers == 1 and not is_raising(handler.body)):
                         self.add_message('W0703', args=exc.name, node=handler.type)
+        
+                    if (not inherit_from_std_ex(exc) and
+                        exc.root().name != BUILTINS_NAME):
+                        self.add_message('catching-non-exception', 
+                                         node=handler.type,
+                                         args=(exc.name, ))
+
                 exceptions_classes += excs
 
 
diff --git a/test/input/func_catching_non_exception.py b/test/input/func_catching_non_exception.py
new file mode 100644
index 0000000..e6bfc57
--- /dev/null
+++ b/test/input/func_catching_non_exception.py
@@ -0,0 +1,41 @@
+"""test non-exceptions catched
+"""
+
+__revision__ = 1
+
+class MyException(object):
+    """ custom 'exception' """
+    pass
+
+class MySecondException(object):
+    """ custom 'exception' """
+    pass
+
+class MyGoodException(Exception):
+    """ custom 'exception' """
+    pass
+
+class MySecondGoodException(MyGoodException):
+    """ custom 'exception' """
+    pass
+
+try:
+    1 + 1
+except MyException:
+    print "oups"
+
+try:
+    1 + 2
+except (MyException, MySecondException):
+    print "oups"
+
+try:
+    1 + 3
+except MyGoodException:
+    print "should work"
+
+try:
+    1 + 3
+except (MyGoodException, MySecondGoodException):
+    print "should work"
+
diff --git a/test/messages/func_catching_non_exception.txt b/test/messages/func_catching_non_exception.txt
new file mode 100644
index 0000000..9dc23eb
--- /dev/null
+++ b/test/messages/func_catching_non_exception.txt
@@ -0,0 +1,3 @@
+E: 24: Catching an exception which doesn't inherit from BaseException: MyException
+E: 29: Catching an exception which doesn't inherit from BaseException: MyException
+E: 29: Catching an exception which doesn't inherit from BaseException: MySecondException
\ No newline at end of file