Verify explicitly that a class is not a known exception class.

This catches a couple of builtins which weren't previously detected
when checking for catching-non-exception, because all builtins were exempted
from this check.

3 files changed, 34 insertions, 3 deletions

diff --git a/pylint/checkers/exceptions.py b/pylint/checkers/exceptions.py
index a67fec5..bb9aa07 100644
--- a/pylint/checkers/exceptions.py
+++ b/pylint/checkers/exceptions.py
@@ -14,11 +14,14 @@
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 """exceptions handling (raising, catching, exceptions classes) checker
 """
+import inspect
 import sys
 
 import astroid
 from astroid import YES, Instance, unpack_infer, List, Tuple
 from logilab.common.compat import builtins
+from logilab.common import decorators
+import six
 
 from pylint.checkers import BaseChecker
 from pylint.checkers.utils import (
@@ -47,12 +50,13 @@ def _annotated_unpack_infer(stmt, context=None):
     for infered in stmt.infer(context):
         if infered is YES:
             continue
-        yield stmt, infered
+        yield stmt, infered   
 
 
 PY3K = sys.version_info >= (3, 0)
 OVERGENERAL_EXCEPTIONS = ('Exception',)
 BUILTINS_NAME = builtins.__name__
+
 MSGS = {
     'E0701': ('Bad except clauses order (%s)',
               'bad-except-order',
@@ -127,6 +131,15 @@ class ExceptionsChecker(BaseChecker):
                ),
               )
 
+    @decorators.cachedproperty
+    def builtin_exceptions(self):
+        """Get a list of the builtins exceptions."""
+        def predicate(obj):
+            return isinstance(obj, type) and issubclass(obj, BaseException)
+
+        members = inspect.getmembers(six.moves.builtins, predicate)
+        return {exc.__name__ for (_, exc) in members}
+
     @check_messages('nonstandard-exception',
                     'raising-bad-type', 'raising-non-exception',
                     'notimplemented-raised', 'bad-exception-context')
@@ -255,8 +268,9 @@ class ExceptionsChecker(BaseChecker):
                                  node=handler.type,
                                  args=(part.as_string(), ))
             return
+
         if (not inherit_from_std_ex(exc) and
-                exc.root().name != BUILTINS_NAME):
+                exc.name not in self.builtin_exceptions):
             if has_known_bases(exc):
                 self.add_message('catching-non-exception',
                                  node=handler.type,
diff --git a/pylint/test/functional/invalid_exceptions_caught.py b/pylint/test/functional/invalid_exceptions_caught.py
index 4bb7148..2392ab0 100644
--- a/pylint/test/functional/invalid_exceptions_caught.py
+++ b/pylint/test/functional/invalid_exceptions_caught.py
@@ -2,7 +2,7 @@
 # pylint: disable=too-many-ancestors, no-absolute-import, import-error
 from __future__ import print_function
 
-import socket
+import socket, binascii
 
 class MyException(object):
     """Custom 'exception'."""
@@ -92,3 +92,18 @@ try:
     1 + 42
 except UNKNOWN_COMPONENTS:
     print("caught")
+
+try:
+    1 + 42
+except binascii.Error:
+    print('builtin and detected')
+
+try:
+    1 + 45
+except object: # [catching-non-exception]
+    print('caught')
+
+try:
+    1 + 42
+except range: # [catching-non-exception]
+    print('caught')
diff --git a/pylint/test/functional/invalid_exceptions_caught.txt b/pylint/test/functional/invalid_exceptions_caught.txt
index 96ebded..3cd4822 100644
--- a/pylint/test/functional/invalid_exceptions_caught.txt
+++ b/pylint/test/functional/invalid_exceptions_caught.txt
@@ -8,3 +8,5 @@ catching-non-exception:72::"Catching an exception which doesn't inherit from Bas
 catching-non-exception:72::"Catching an exception which doesn't inherit from BaseException: None"
 catching-non-exception:72::"Catching an exception which doesn't inherit from BaseException: list([4, 5, 6])"
 catching-non-exception:85::"Catching an exception which doesn't inherit from BaseException: NON_EXCEPTION_TUPLE"
+catching-non-exception:103::"Catching an exception which doesn't inherit from BaseException: object"
+catching-non-exception:108::"Catching an exception which doesn't inherit from BaseException: range"