bpo-36820: Break unnecessary cycle in socket.py, codeop.py and dyld.py (GH-13135)
Break cycle generated when saving an exception in socket.py, codeop.py and dyld.py as they keep alive not only the exception but user objects through the ``__traceback__`` attribute.
https://bugs.python.org/issue36820
Automerge-Triggered-By: @pablogsal
diff --git a/Lib/codeop.py b/Lib/codeop.py
index fc7e1e7..082285f 100644
--- a/Lib/codeop.py
+++ b/Lib/codeop.py
@@ -93,10 +93,13 @@
except SyntaxError as e:
err2 = e
- if code:
- return code
- if not code1 and repr(err1) == repr(err2):
- raise err1
+ try:
+ if code:
+ return code
+ if not code1 and repr(err1) == repr(err2):
+ raise err1
+ finally:
+ err1 = err2 = None
def _compile(source, filename, symbol):
return compile(source, filename, symbol, PyCF_DONT_IMPLY_DEDENT)
diff --git a/Lib/ctypes/macholib/dyld.py b/Lib/ctypes/macholib/dyld.py
index c158e67..9d86b05 100644
--- a/Lib/ctypes/macholib/dyld.py
+++ b/Lib/ctypes/macholib/dyld.py
@@ -149,6 +149,8 @@
return dyld_find(fn, executable_path=executable_path, env=env)
except ValueError:
raise error
+ finally:
+ error = None
def test_dyld_find():
env = {}
diff --git a/Lib/socket.py b/Lib/socket.py
index 84a5dcb..374f112 100755
--- a/Lib/socket.py
+++ b/Lib/socket.py
@@ -839,7 +839,11 @@
sock.close()
if err is not None:
- raise err
+ try:
+ raise err
+ finally:
+ # Break explicitly a reference cycle
+ err = None
else:
raise error("getaddrinfo returns an empty list")