False-positive unreachable code

[dolik-rce]

Bug description

import signal
import sys

def handle_signal():
    signal.signal(signal.SIGINT, lambda sig, frame: [print("Aborted using CTRL+C"), sys.exit(1)])
    print("Signal handler installed.")

Configuration

No response

Command used

python3 -m pylint a.py

Pylint output

************* Module test
test.py:6:4: W0101: Unreachable code (unreachable)

Expected behavior

No warning should be emitted, because the "unreachable" code is actually called when executed.

Pylint version

pylint 2.17.2
astroid 2.15.2
Python 3.9.2 (default, Feb 28 2021, 17:03:44) 
[GCC 10.2.1 20210110]

It did work before I upgraded, at least with this version: 

pylint 2.15.4
astroid 2.12.11
Python 3.9.2 (default, Feb 28 2021, 17:03:44) 
[GCC 10.2.1 20210110]

OS / Environment

Debian 11.3, bash 5.1.4

Additional dependencies

No response

[jacobtylerwalls]

Thanks! Simpler repro:

import sys
lambda code: [sys.exit(code)]
print('hello')

[jacobtylerwalls]

Regression in bed42ba.

[jacobtylerwalls]

This line shouldn't assume direct parentage by lambda, we need to go higher up (in the bug report, a list intervenes first):

pylint/pylint/checkers/base/basic_checker.py

Line 666 in bed42ba

or isinstance(node.parent, nodes.Lambda)

cc / @clavedeluna