#2358: add py3k warning to sys.exc_clear().

Lib/test/test_py3kwarn.py

@@ -94,6 +94,11 @@ class TestPy3KWarnings(unittest.TestCase):
         with catch_warning() as w:
             self.assertWarning(sorted(lst, cmp), w, expected)
 
+    def test_sys_exc_clear(self):
+        expected = 'sys.exc_clear() not supported in 3.x. Use except clauses.'
+        with catch_warning() as w:
+            self.assertWarning(sys.exc_clear(), w, expected)
+
 def test_main():
     run_unittest(TestPy3KWarnings)
 

Misc/NEWS

@@ -12,6 +12,8 @@ What's New in Python 2.6 alpha 2?
 Core and builtins
 -----------------
  
+- Issue #2358: Add a Py3k warning on sys.exc_clear() usage.
+
 - Issue #2400: Allow relative imports to "import *".
 
 - Issue 1745.  Backport print function with:

Python/sysmodule.c

@@ -169,8 +169,16 @@ clause in the current stack frame or in an older stack frame."
 static PyObject *
 sys_exc_clear(PyObject *self, PyObject *noargs)
 {
-	PyThreadState *tstate = PyThreadState_GET();
+	PyThreadState *tstate;
 	PyObject *tmp_type, *tmp_value, *tmp_tb;
+
+	if (Py_Py3kWarningFlag &&
+	    PyErr_Warn(PyExc_DeprecationWarning,
+		       "sys.exc_clear() not supported in 3.x. "
+		       "Use except clauses.") < 0)
+		return NULL;
+
+	tstate = PyThreadState_GET();
 	tmp_type = tstate->exc_type;
 	tmp_value = tstate->exc_value;
 	tmp_tb = tstate->exc_traceback;