Updates to the with-statement:
- New semantics for __exit__() -- it must re-raise the exception
if type is not None; the with-statement itself doesn't do this.
(See the updated PEP for motivation.)
- Added context managers to:
- file
- thread.LockType
- threading.{Lock,RLock,Condition,Semaphore,BoundedSemaphore}
- decimal.Context
- Added contextlib.py, which defines @contextmanager, nested(), closing().
- Unit tests all around; bot no docs yet.
diff --git a/Python/ceval.c b/Python/ceval.c
index 3732f6d..3ef853e 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -2200,23 +2200,37 @@
The code here just sets the stack up for the call;
separate CALL_FUNCTION(3) and POP_TOP opcodes are
emitted by the compiler.
+
+ In addition, if the stack represents an exception,
+ we "zap" this information; __exit__() should
+ re-raise the exception if it wants to, and if
+ __exit__() returns normally, END_FINALLY should
+ *not* re-raise the exception. (But non-local
+ gotos should still be resumed.)
*/
x = TOP();
u = SECOND();
if (PyInt_Check(u) || u == Py_None) {
u = v = w = Py_None;
+ Py_INCREF(u);
+ Py_INCREF(v);
+ Py_INCREF(w);
}
else {
v = THIRD();
w = FOURTH();
+ /* Zap the exception from the stack,
+ to fool END_FINALLY. */
+ STACKADJ(-2);
+ SET_TOP(x);
+ Py_INCREF(Py_None);
+ SET_SECOND(Py_None);
}
- Py_INCREF(u);
- Py_INCREF(v);
- Py_INCREF(w);
- PUSH(u);
- PUSH(v);
- PUSH(w);
+ STACKADJ(3);
+ SET_THIRD(u);
+ SET_SECOND(v);
+ SET_TOP(w);
break;
}