Merge #16961: test: Remove python dead code linter

f4beb4996d test: Remove python dead code linter (Wladimir J. van der Laan)

Pull request description:

  Primarily I'd like to remove this because it is very imprecise, due to Python's dynamic nature, giving it a large list of false positives that need to be listed as exceptions. See for example #16906.

  It's also a frequent source of complaints. I'm doubtful of the usefulness of checking for dead code in a linter in the first place.
  Having some dead code in the test framework for a while is not a
  disaster.

ACKs for top commit:
  sdaftuar:
    utACK f4beb4996d
  practicalswift:
    ACK f4beb4996d -- diff looks correct
  jamesob:
    ACK f4beb4996d

Tree-SHA512: 329b1555210311d5d15799fd2cb794b3208b0ac4d8a2ffaf4dece1bcc3e0e8b1fe952d5e7a394f94a98919cab579fb579eae7db2a796cc9a1a42ef495dd17507

ci/lint/04_install.sh

@@ -8,7 +8,6 @@ export LC_ALL=C
 
 travis_retry pip3 install codespell==1.15.0
 travis_retry pip3 install flake8==3.7.8
-travis_retry pip3 install vulture==1.0
 
 SHELLCHECK_VERSION=v0.6.0
 curl -s "https://storage.googleapis.com/shellcheck/shellcheck-${SHELLCHECK_VERSION}.linux.x86_64.tar.xz" | tar --xz -xf - --directory /tmp/

test/lint/lint-python-dead-code-whitelist

@@ -1,46 +0,0 @@
-BadInputOutpointIndex  # unused class (test/functional/data/invalid_txs.py)
-_.carbon_path  # unused attribute (contrib/macdeploy/custom_dsstore.py)
-connection_lost  # unused function (test/functional/test_framework/mininode.py)
-connection_made  # unused function (test/functional/test_framework/mininode.py)
-_.converter  # unused attribute (test/functional/test_framework/test_framework.py)
-_.daemon  # unused attribute (test/functional/test_framework/socks5.py)
-data_received  # unused function (test/functional/test_framework/mininode.py)
-DuplicateInput  # unused class (test/functional/data/invalid_txs.py)
-DisabledOpcodeTemplates  # unused class (test/functional/data/invalid_txs.py)
-_.filename  # unused attribute (contrib/macdeploy/custom_dsstore.py)
-InvalidOPIFConstruction  # unused class (test/functional/data/invalid_txs.py)
-_.is_compressed  # unused property (test/functional/test_framework/key.py)
-legacy  # unused variable (test/functional/test_framework/address.py)
-msg_generic  # unused class (test/functional/test_framework/messages.py)
-NonexistentInput  # unused class (test/functional/data/invalid_txs.py)
-on_addr  # unused function (test/functional/test_framework/mininode.py)
-on_blocktxn  # unused function (test/functional/test_framework/mininode.py)
-on_block  # unused function (test/functional/test_framework/mininode.py)
-on_cmpctblock  # unused function (test/functional/test_framework/mininode.py)
-on_feefilter  # unused function (test/functional/test_framework/mininode.py)
-on_getaddr  # unused function (test/functional/test_framework/mininode.py)
-on_getblocks  # unused function (test/functional/test_framework/mininode.py)
-on_getblocktxn  # unused function (test/functional/test_framework/mininode.py)
-on_getdata  # unused function (test/functional/test_framework/mininode.py)
-on_getheaders  # unused function (test/functional/test_framework/mininode.py)
-on_headers  # unused function (test/functional/test_framework/mininode.py)
-on_inv  # unused function (test/functional/test_framework/mininode.py)
-on_mempool  # unused function (test/functional/test_framework/mininode.py)
-on_notfound  # unused function (test/functional/test_framework/mininode.py)
-on_ping  # unused function (test/functional/test_framework/mininode.py)
-on_pong  # unused function (test/functional/test_framework/mininode.py)
-on_reject  # unused function (test/functional/test_framework/mininode.py)
-on_sendcmpct  # unused function (test/functional/test_framework/mininode.py)
-on_sendheaders  # unused function (test/functional/test_framework/mininode.py)
-on_tx  # unused function (test/functional/test_framework/mininode.py)
-on_verack  # unused function (test/functional/test_framework/mininode.py)
-on_version  # unused function (test/functional/test_framework/mininode.py)
-_.optionxform  # unused attribute (test/util/bitcoin-util-test.py)
-OutputMissing  # unused class (test/functional/data/invalid_txs.py)
-_.posix_path  # unused attribute (contrib/macdeploy/custom_dsstore.py)
-profile_with_perf  # unused function (test/functional/test_framework/test_node.py)
-SizeTooSmall  # unused class (test/functional/data/invalid_txs.py)
-SpendNegative  # unused class (test/functional/data/invalid_txs.py)
-SpendTooMuch  # unused class (test/functional/data/invalid_txs.py)
-TooManySigops  # unused class (test/functional/data/invalid_txs.py)
-verify_ecdsa  # unused function (test/functional/test_framework/key.py)

test/lint/lint-python-dead-code.sh

@@ -1,23 +0,0 @@
-#!/usr/bin/env bash
-#
-# Copyright (c) 2018 The Bitcoin Core developers
-# Distributed under the MIT software license, see the accompanying
-# file COPYING or http://www.opensource.org/licenses/mit-license.php.
-#
-# Find dead Python code.
-
-export LC_ALL=C
-
-if ! command -v vulture > /dev/null; then
-    echo "Skipping Python dead code linting since vulture is not installed. Install by running \"pip3 install vulture\""
-    exit 0
-fi
-
-VULTURE_SUPPRESSIONS=$(dirname "${BASH_SOURCE[0]}")/lint-python-dead-code-whitelist
-if ! vulture \
-    --min-confidence 60 \
-    $(git rev-parse --show-toplevel) \
-    "${VULTURE_SUPPRESSIONS}"; then
-    echo "False positives? Suppressions can be added to ${VULTURE_SUPPRESSIONS}"
-    exit 1
-fi