Inspection for `with threading.Lock():` (#5245)

Using `with threading.Lock():` directly has no effect.

Correct usage is:
```
lock = threading.Lock()
with lock:
    ...
```

This applies for:
  * threading.Lock
  * threading.RLock
  * threading.Condition
  * threading.Semaphore
  * threading.BoundedSemaphore

Signed-off-by: Martin Basti <mbasti@redhat.com>

2 files changed, 69 insertions, 0 deletions

diff --git a/tests/functional/u/useless/useless_with_lock.py b/tests/functional/u/useless/useless_with_lock.py
new file mode 100644
index 000000000..19d664084
--- /dev/null
+++ b/tests/functional/u/useless/useless_with_lock.py
@@ -0,0 +1,58 @@
+"""Tests for the useless-with-lock message"""
+# pylint: disable=missing-docstring
+import threading
+from threading import Lock, RLock, Condition, Semaphore, BoundedSemaphore
+
+
+with threading.Lock():  # [useless-with-lock]
+    ...
+
+with Lock():  # [useless-with-lock]
+    ...
+
+with threading.Lock() as this_shouldnt_matter:  # [useless-with-lock]
+    ...
+
+with threading.RLock():  # [useless-with-lock]
+    ...
+
+with RLock():  # [useless-with-lock]
+    ...
+
+with threading.Condition():  # [useless-with-lock]
+    ...
+
+with Condition():  # [useless-with-lock]
+    ...
+
+with threading.Semaphore():  # [useless-with-lock]
+    ...
+
+with Semaphore():  # [useless-with-lock]
+    ...
+
+with threading.BoundedSemaphore():  # [useless-with-lock]
+    ...
+
+with BoundedSemaphore():  # [useless-with-lock]
+    ...
+
+lock = threading.Lock()
+with lock:  # this is ok
+    ...
+
+rlock = threading.RLock()
+with rlock:  # this is ok
+    ...
+
+cond = threading.Condition()
+with cond:  # this is ok
+    ...
+
+sem = threading.Semaphore()
+with sem:  # this is ok
+    ...
+
+b_sem = threading.BoundedSemaphore()
+with b_sem:  # this is ok
+    ...
diff --git a/tests/functional/u/useless/useless_with_lock.txt b/tests/functional/u/useless/useless_with_lock.txt
new file mode 100644
index 000000000..51435c35e
--- /dev/null
+++ b/tests/functional/u/useless/useless_with_lock.txt
@@ -0,0 +1,11 @@
+useless-with-lock:7:0::'threading.Lock()' directly created in 'with' has no effect:HIGH
+useless-with-lock:10:0::'threading.Lock()' directly created in 'with' has no effect:HIGH
+useless-with-lock:13:0::'threading.Lock()' directly created in 'with' has no effect:HIGH
+useless-with-lock:16:0::'threading.RLock()' directly created in 'with' has no effect:HIGH
+useless-with-lock:19:0::'threading.RLock()' directly created in 'with' has no effect:HIGH
+useless-with-lock:22:0::'threading.Condition()' directly created in 'with' has no effect:HIGH
+useless-with-lock:25:0::'threading.Condition()' directly created in 'with' has no effect:HIGH
+useless-with-lock:28:0::'threading.Semaphore()' directly created in 'with' has no effect:HIGH
+useless-with-lock:31:0::'threading.Semaphore()' directly created in 'with' has no effect:HIGH
+useless-with-lock:34:0::'threading.BoundedSemaphore()' directly created in 'with' has no effect:HIGH
+useless-with-lock:37:0::'threading.BoundedSemaphore()' directly created in 'with' has no effect:HIGH