18 files changed, 1149 insertions, 0 deletions
diff --git a/test/lint/README.md b/test/lint/README.md
new file mode 100644
index 0000000000..15974a3598
--- /dev/null
+++ b/test/lint/README.md
@@ -0,0 +1,29 @@
+This folder contains lint scripts.
+
+check-doc.py
+============
+Check for missing documentation of command line options.
+
+commit-script-check.sh
+======================
+Verification of [scripted diffs](/doc/developer-notes.md#scripted-diffs).
+
+git-subtree-check.sh
+====================
+Run this script from the root of the repository to verify that a subtree matches the contents of
+the commit it claims to have been updated to.
+
+To use, make sure that you have fetched the upstream repository branch in which the subtree is
+maintained:
+* for `src/secp256k1`: https://github.com/bitcoin-core/secp256k1.git (branch master)
+* for `src/leveldb`: https://github.com/bitcoin-core/leveldb.git (branch bitcoin-fork)
+* for `src/univalue`: https://github.com/bitcoin-core/univalue.git (branch master)
+* for `src/crypto/ctaes`: https://github.com/bitcoin-core/ctaes.git (branch master)
+
+Usage: `git-subtree-check.sh DIR (COMMIT)`
+
+`COMMIT` may be omitted, in which case `HEAD` is used.
+
+lint-all.sh
+===========
+Calls other scripts with the `lint-` prefix.
diff --git a/test/lint/check-doc.py b/test/lint/check-doc.py
new file mode 100755
index 0000000000..89776b2a6b
--- /dev/null
+++ b/test/lint/check-doc.py
@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+# Copyright (c) 2015-2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+'''
+This checks if all command line args are documented.
+Return value is 0 to indicate no error.
+
+Author: @MarcoFalke
+'''
+
+from subprocess import check_output
+import re
+import sys
+
+FOLDER_GREP = 'src'
+FOLDER_TEST = 'src/test/'
+REGEX_ARG = '(?:ForceSet|SoftSet|Get|Is)(?:Bool)?Args?(?:Set)?\("(-[^"]+)"'
+REGEX_DOC = 'AddArg\("(-[^"=]+?)(?:=|")'
+CMD_ROOT_DIR = '`git rev-parse --show-toplevel`/{}'.format(FOLDER_GREP)
+CMD_GREP_ARGS = r"git grep --perl-regexp '{}' -- {} ':(exclude){}'".format(REGEX_ARG, CMD_ROOT_DIR, FOLDER_TEST)
+CMD_GREP_DOCS = r"git grep --perl-regexp '{}' {}".format(REGEX_DOC, CMD_ROOT_DIR)
+# list unsupported, deprecated and duplicate args as they need no documentation
+SET_DOC_OPTIONAL = set(['-rpcssl', '-benchmark', '-h', '-help', '-socks', '-tor', '-debugnet', '-whitelistalwaysrelay', '-promiscuousmempoolflags', '-blockminsize', '-dbcrashratio', '-forcecompactdb', '-usehd'])
+
+
+def main():
+    used = check_output(CMD_GREP_ARGS, shell=True, universal_newlines=True)
+    docd = check_output(CMD_GREP_DOCS, shell=True, universal_newlines=True)
+
+    args_used = set(re.findall(re.compile(REGEX_ARG), used))
+    args_docd = set(re.findall(re.compile(REGEX_DOC), docd)).union(SET_DOC_OPTIONAL)
+    args_need_doc = args_used.difference(args_docd)
+    args_unknown = args_docd.difference(args_used)
+
+    print("Args used        : {}".format(len(args_used)))
+    print("Args documented  : {}".format(len(args_docd)))
+    print("Args undocumented: {}".format(len(args_need_doc)))
+    print(args_need_doc)
+    print("Args unknown     : {}".format(len(args_unknown)))
+    print(args_unknown)
+
+    sys.exit(len(args_need_doc))
+
+
+if __name__ == "__main__":
+    main()
diff --git a/test/lint/check-rpc-mappings.py b/test/lint/check-rpc-mappings.py
new file mode 100755
index 0000000000..c3cdeef580
--- /dev/null
+++ b/test/lint/check-rpc-mappings.py
@@ -0,0 +1,158 @@
+#!/usr/bin/env python3
+# Copyright (c) 2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Check RPC argument consistency."""
+
+from collections import defaultdict
+import os
+import re
+import sys
+
+# Source files (relative to root) to scan for dispatch tables
+SOURCES = [
+    "src/rpc/server.cpp",
+    "src/rpc/blockchain.cpp",
+    "src/rpc/mining.cpp",
+    "src/rpc/misc.cpp",
+    "src/rpc/net.cpp",
+    "src/rpc/rawtransaction.cpp",
+    "src/wallet/rpcwallet.cpp",
+]
+# Source file (relative to root) containing conversion mapping
+SOURCE_CLIENT = 'src/rpc/client.cpp'
+# Argument names that should be ignored in consistency checks
+IGNORE_DUMMY_ARGS = {'dummy', 'arg0', 'arg1', 'arg2', 'arg3', 'arg4', 'arg5', 'arg6', 'arg7', 'arg8', 'arg9'}
+
+class RPCCommand:
+    def __init__(self, name, args):
+        self.name = name
+        self.args = args
+
+class RPCArgument:
+    def __init__(self, names, idx):
+        self.names = names
+        self.idx = idx
+        self.convert = False
+
+def parse_string(s):
+    assert s[0] == '"'
+    assert s[-1] == '"'
+    return s[1:-1]
+
+def process_commands(fname):
+    """Find and parse dispatch table in implementation file `fname`."""
+    cmds = []
+    in_rpcs = False
+    with open(fname, "r", encoding="utf8") as f:
+        for line in f:
+            line = line.rstrip()
+            if not in_rpcs:
+                if re.match("static const CRPCCommand .*\[\] =", line):
+                    in_rpcs = True
+            else:
+                if line.startswith('};'):
+                    in_rpcs = False
+                elif '{' in line and '"' in line:
+                    m = re.search('{ *("[^"]*"), *("[^"]*"), *&([^,]*), *{([^}]*)} *},', line)
+                    assert m, 'No match to table expression: %s' % line
+                    name = parse_string(m.group(2))
+                    args_str = m.group(4).strip()
+                    if args_str:
+                        args = [RPCArgument(parse_string(x.strip()).split('|'), idx) for idx, x in enumerate(args_str.split(','))]
+                    else:
+                        args = []
+                    cmds.append(RPCCommand(name, args))
+    assert not in_rpcs and cmds, "Something went wrong with parsing the C++ file: update the regexps"
+    return cmds
+
+def process_mapping(fname):
+    """Find and parse conversion table in implementation file `fname`."""
+    cmds = []
+    in_rpcs = False
+    with open(fname, "r", encoding="utf8") as f:
+        for line in f:
+            line = line.rstrip()
+            if not in_rpcs:
+                if line == 'static const CRPCConvertParam vRPCConvertParams[] =':
+                    in_rpcs = True
+            else:
+                if line.startswith('};'):
+                    in_rpcs = False
+                elif '{' in line and '"' in line:
+                    m = re.search('{ *("[^"]*"), *([0-9]+) *, *("[^"]*") *},', line)
+                    assert m, 'No match to table expression: %s' % line
+                    name = parse_string(m.group(1))
+                    idx = int(m.group(2))
+                    argname = parse_string(m.group(3))
+                    cmds.append((name, idx, argname))
+    assert not in_rpcs and cmds
+    return cmds
+
+def main():
+    root = sys.argv[1]
+
+    # Get all commands from dispatch tables
+    cmds = []
+    for fname in SOURCES:
+        cmds += process_commands(os.path.join(root, fname))
+
+    cmds_by_name = {}
+    for cmd in cmds:
+        cmds_by_name[cmd.name] = cmd
+
+    # Get current convert mapping for client
+    client = SOURCE_CLIENT
+    mapping = set(process_mapping(os.path.join(root, client)))
+
+    print('* Checking consistency between dispatch tables and vRPCConvertParams')
+
+    # Check mapping consistency
+    errors = 0
+    for (cmdname, argidx, argname) in mapping:
+        try:
+            rargnames = cmds_by_name[cmdname].args[argidx].names
+        except IndexError:
+            print('ERROR: %s argument %i (named %s in vRPCConvertParams) is not defined in dispatch table' % (cmdname, argidx, argname))
+            errors += 1
+            continue
+        if argname not in rargnames:
+            print('ERROR: %s argument %i is named %s in vRPCConvertParams but %s in dispatch table' % (cmdname, argidx, argname, rargnames), file=sys.stderr)
+            errors += 1
+
+    # Check for conflicts in vRPCConvertParams conversion
+    # All aliases for an argument must either be present in the
+    # conversion table, or not. Anything in between means an oversight
+    # and some aliases won't work.
+    for cmd in cmds:
+        for arg in cmd.args:
+            convert = [((cmd.name, arg.idx, argname) in mapping) for argname in arg.names]
+            if any(convert) != all(convert):
+                print('ERROR: %s argument %s has conflicts in vRPCConvertParams conversion specifier %s' % (cmd.name, arg.names, convert))
+                errors += 1
+            arg.convert = all(convert)
+
+    # Check for conversion difference by argument name.
+    # It is preferable for API consistency that arguments with the same name
+    # have the same conversion, so bin by argument name.
+    all_methods_by_argname = defaultdict(list)
+    converts_by_argname = defaultdict(list)
+    for cmd in cmds:
+        for arg in cmd.args:
+            for argname in arg.names:
+                all_methods_by_argname[argname].append(cmd.name)
+                converts_by_argname[argname].append(arg.convert)
+
+    for argname, convert in converts_by_argname.items():
+        if all(convert) != any(convert):
+            if argname in IGNORE_DUMMY_ARGS:
+                # these are testing or dummy, don't warn for them
+                continue
+            print('WARNING: conversion mismatch for argument named %s (%s)' %
+                  (argname, list(zip(all_methods_by_argname[argname], converts_by_argname[argname]))))
+
+    sys.exit(errors > 0)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/test/lint/commit-script-check.sh b/test/lint/commit-script-check.sh
new file mode 100755
index 0000000000..f1327469f3
--- /dev/null
+++ b/test/lint/commit-script-check.sh
@@ -0,0 +1,47 @@
+#!/bin/sh
+# Copyright (c) 2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+# This simple script checks for commits beginning with: scripted-diff:
+# If found, looks for a script between the lines -BEGIN VERIFY SCRIPT- and
+# -END VERIFY SCRIPT-. If no ending is found, it reads until the end of the
+# commit message.
+
+# The resulting script should exactly transform the previous commit into the current
+# one. Any remaining diff signals an error.
+
+export LC_ALL=C
+if test "x$1" = "x"; then
+    echo "Usage: $0 <commit>..."
+    exit 1
+fi
+
+RET=0
+PREV_BRANCH=`git name-rev --name-only HEAD`
+PREV_HEAD=`git rev-parse HEAD`
+for i in `git rev-list --reverse $1`; do
+    if git rev-list -n 1 --pretty="%s" $i | grep -q "^scripted-diff:"; then
+        git checkout --quiet $i^ || exit
+        SCRIPT="`git rev-list --format=%b -n1 $i | sed '/^-BEGIN VERIFY SCRIPT-$/,/^-END VERIFY SCRIPT-$/{//!b};d'`"
+        if test "x$SCRIPT" = "x"; then
+            echo "Error: missing script for: $i"
+            echo "Failed"
+            RET=1
+        else
+            echo "Running script for: $i"
+            echo "$SCRIPT"
+            eval "$SCRIPT"
+            git --no-pager diff --exit-code $i && echo "OK" || (echo "Failed"; false) || RET=1
+        fi
+        git reset --quiet --hard HEAD
+     else
+        if git rev-list "--format=%b" -n1 $i | grep -q '^-\(BEGIN\|END\)[ a-zA-Z]*-$'; then
+            echo "Error: script block marker but no scripted-diff in title"
+            echo "Failed"
+            RET=1
+        fi
+    fi
+done
+git checkout --quiet $PREV_BRANCH 2>/dev/null || git checkout --quiet $PREV_HEAD
+exit $RET
diff --git a/test/lint/git-subtree-check.sh b/test/lint/git-subtree-check.sh
new file mode 100755
index 0000000000..85e8b841b6
--- /dev/null
+++ b/test/lint/git-subtree-check.sh
@@ -0,0 +1,95 @@
+#!/bin/sh
+# Copyright (c) 2015 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+export LC_ALL=C
+DIR="$1"
+COMMIT="$2"
+if [ -z "$COMMIT" ]; then
+    COMMIT=HEAD
+fi
+
+# Taken from git-subtree (Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>)
+find_latest_squash()
+{
+	dir="$1"
+	sq=
+	main=
+	sub=
+	git log --grep="^git-subtree-dir: $dir/*\$" \
+		--pretty=format:'START %H%n%s%n%n%b%nEND%n' "$COMMIT" |
+	while read a b _; do
+		case "$a" in
+			START) sq="$b" ;;
+			git-subtree-mainline:) main="$b" ;;
+			git-subtree-split:) sub="$b" ;;
+			END)
+				if [ -n "$sub" ]; then
+					if [ -n "$main" ]; then
+						# a rejoin commit?
+						# Pretend its sub was a squash.
+						sq="$sub"
+					fi
+					echo "$sq" "$sub"
+					break
+				fi
+				sq=
+				main=
+				sub=
+				;;
+		esac
+	done
+}
+
+# find latest subtree update
+latest_squash="$(find_latest_squash "$DIR")"
+if [ -z "$latest_squash" ]; then
+    echo "ERROR: $DIR is not a subtree" >&2
+    exit 2
+fi
+set $latest_squash
+old=$1
+rev=$2
+
+# get the tree in the current commit
+tree_actual=$(git ls-tree -d "$COMMIT" "$DIR" | head -n 1)
+if [ -z "$tree_actual" ]; then
+    echo "FAIL: subtree directory $DIR not found in $COMMIT" >&2
+    exit 1
+fi
+set $tree_actual
+tree_actual_type=$2
+tree_actual_tree=$3
+echo "$DIR in $COMMIT currently refers to $tree_actual_type $tree_actual_tree"
+if [ "d$tree_actual_type" != "dtree" ]; then
+    echo "FAIL: subtree directory $DIR is not a tree in $COMMIT" >&2
+    exit 1
+fi
+
+# get the tree at the time of the last subtree update
+tree_commit=$(git show -s --format="%T" $old)
+echo "$DIR in $COMMIT was last updated in commit $old (tree $tree_commit)"
+
+# ... and compare the actual tree with it
+if [ "$tree_actual_tree" != "$tree_commit" ]; then
+    git diff $tree_commit $tree_actual_tree >&2
+    echo "FAIL: subtree directory was touched without subtree merge" >&2
+    exit 1
+fi
+
+# get the tree in the subtree commit referred to
+if [ "d$(git cat-file -t $rev 2>/dev/null)" != dcommit ]; then
+    echo "subtree commit $rev unavailable: cannot compare" >&2
+    exit
+fi
+tree_subtree=$(git show -s --format="%T" $rev)
+echo "$DIR in $COMMIT was last updated to upstream commit $rev (tree $tree_subtree)"
+
+# ... and compare the actual tree with it
+if [ "$tree_actual_tree" != "$tree_subtree" ]; then
+    echo "FAIL: subtree update commit differs from upstream tree!" >&2
+    exit 1
+fi
+
+echo "GOOD"
diff --git a/test/lint/lint-all.sh b/test/lint/lint-all.sh
new file mode 100755
index 0000000000..7c4f96cb3b
--- /dev/null
+++ b/test/lint/lint-all.sh
@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# This script runs all contrib/devtools/lint-*.sh files, and fails if any exit
+# with a non-zero status code.
+
+# This script is intentionally locale dependent by not setting "export LC_ALL=C"
+# in order to allow for the executed lint scripts to opt in or opt out of locale
+# dependence themselves.
+
+set -u
+
+SCRIPTDIR=$(dirname "${BASH_SOURCE[0]}")
+LINTALL=$(basename "${BASH_SOURCE[0]}")
+
+for f in "${SCRIPTDIR}"/lint-*.sh; do
+  if [ "$(basename "$f")" != "$LINTALL" ]; then
+    if ! "$f"; then
+      echo "^---- failure generated from $f"
+      exit 1
+    fi
+  fi
+done
diff --git a/test/lint/lint-filenames.sh b/test/lint/lint-filenames.sh
new file mode 100755
index 0000000000..5391e43d91
--- /dev/null
+++ b/test/lint/lint-filenames.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2018 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Make sure only lowercase alphanumerics (a-z0-9), underscores (_),
+# hyphens (-) and dots (.) are used in source code filenames.
+
+export LC_ALL=C
+
+EXIT_CODE=0
+OUTPUT=$(git ls-files --full-name -- "*.[cC][pP][pP]" "*.[hH]" "*.[pP][yY]" "*.[sS][hH]" | \
+    grep -vE '^[a-z0-9_./-]+$' | \
+    grep -vE '^src/(secp256k1|univalue)/')
+
+if [[ ${OUTPUT} != "" ]]; then
+    echo "Use only lowercase alphanumerics (a-z0-9), underscores (_), hyphens (-) and dots (.)"
+    echo "in source code filenames:"
+    echo
+    echo "${OUTPUT}"
+    EXIT_CODE=1
+fi
+exit ${EXIT_CODE}
diff --git a/test/lint/lint-include-guards.sh b/test/lint/lint-include-guards.sh
new file mode 100755
index 0000000000..464969794b
--- /dev/null
+++ b/test/lint/lint-include-guards.sh
@@ -0,0 +1,30 @@
+#!/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.
+#
+# Check include guards.
+
+export LC_ALL=C
+HEADER_ID_PREFIX="BITCOIN_"
+HEADER_ID_SUFFIX="_H"
+
+REGEXP_EXCLUDE_FILES_WITH_PREFIX="src/(crypto/ctaes/|leveldb/|secp256k1/|tinyformat.h|univalue/)"
+
+EXIT_CODE=0
+for HEADER_FILE in $(git ls-files -- "*.h" | grep -vE "^${REGEXP_EXCLUDE_FILES_WITH_PREFIX}")
+do
+    HEADER_ID_BASE=$(cut -f2- -d/ <<< "${HEADER_FILE}" | sed "s/\.h$//g" | tr / _ | tr "[:lower:]" "[:upper:]")
+    HEADER_ID="${HEADER_ID_PREFIX}${HEADER_ID_BASE}${HEADER_ID_SUFFIX}"
+    if [[ $(grep -cE "^#(ifndef|define) ${HEADER_ID}" "${HEADER_FILE}") != 2 ]]; then
+        echo "${HEADER_FILE} seems to be missing the expected include guard:"
+        echo "  #ifndef ${HEADER_ID}"
+        echo "  #define ${HEADER_ID}"
+        echo "  ..."
+        echo "  #endif // ${HEADER_ID}"
+        echo
+        EXIT_CODE=1
+    fi
+done
+exit ${EXIT_CODE}
diff --git a/test/lint/lint-includes.sh b/test/lint/lint-includes.sh
new file mode 100755
index 0000000000..fdc3f5bd35
--- /dev/null
+++ b/test/lint/lint-includes.sh
@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2018 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Check for duplicate includes.
+# Guard against accidental introduction of new Boost dependencies.
+# Check includes: Check for duplicate includes. Enforce bracket syntax includes.
+
+export LC_ALL=C
+IGNORE_REGEXP="/(leveldb|secp256k1|univalue)/"
+
+filter_suffix() {
+    git ls-files | grep -E "^src/.*\.${1}"'$' | grep -Ev "${IGNORE_REGEXP}"
+}
+
+EXIT_CODE=0
+
+for HEADER_FILE in $(filter_suffix h); do
+    DUPLICATE_INCLUDES_IN_HEADER_FILE=$(grep -E "^#include " < "${HEADER_FILE}" | sort | uniq -d)
+    if [[ ${DUPLICATE_INCLUDES_IN_HEADER_FILE} != "" ]]; then
+        echo "Duplicate include(s) in ${HEADER_FILE}:"
+        echo "${DUPLICATE_INCLUDES_IN_HEADER_FILE}"
+        echo
+        EXIT_CODE=1
+    fi
+done
+
+for CPP_FILE in $(filter_suffix cpp); do
+    DUPLICATE_INCLUDES_IN_CPP_FILE=$(grep -E "^#include " < "${CPP_FILE}" | sort | uniq -d)
+    if [[ ${DUPLICATE_INCLUDES_IN_CPP_FILE} != "" ]]; then
+        echo "Duplicate include(s) in ${CPP_FILE}:"
+        echo "${DUPLICATE_INCLUDES_IN_CPP_FILE}"
+        echo
+        EXIT_CODE=1
+    fi
+done
+
+INCLUDED_CPP_FILES=$(git grep -E "^#include [<\"][^>\"]+\.cpp[>\"]" -- "*.cpp" "*.h")
+if [[ ${INCLUDED_CPP_FILES} != "" ]]; then
+    echo "The following files #include .cpp files:"
+    echo "${INCLUDED_CPP_FILES}"
+    echo
+    EXIT_CODE=1
+fi
+
+EXPECTED_BOOST_INCLUDES=(
+    boost/algorithm/string.hpp
+    boost/algorithm/string/case_conv.hpp
+    boost/algorithm/string/classification.hpp
+    boost/algorithm/string/join.hpp
+    boost/algorithm/string/predicate.hpp
+    boost/algorithm/string/replace.hpp
+    boost/algorithm/string/split.hpp
+    boost/assign/std/vector.hpp
+    boost/bind.hpp
+    boost/chrono/chrono.hpp
+    boost/date_time/posix_time/posix_time.hpp
+    boost/filesystem.hpp
+    boost/filesystem/detail/utf8_codecvt_facet.hpp
+    boost/filesystem/fstream.hpp
+    boost/interprocess/sync/file_lock.hpp
+    boost/multi_index/hashed_index.hpp
+    boost/multi_index/ordered_index.hpp
+    boost/multi_index/sequenced_index.hpp
+    boost/multi_index_container.hpp
+    boost/optional.hpp
+    boost/preprocessor/cat.hpp
+    boost/preprocessor/stringize.hpp
+    boost/program_options/detail/config_file.hpp
+    boost/scoped_array.hpp
+    boost/signals2/connection.hpp
+    boost/signals2/last_value.hpp
+    boost/signals2/signal.hpp
+    boost/test/unit_test.hpp
+    boost/thread.hpp
+    boost/thread/condition_variable.hpp
+    boost/thread/mutex.hpp
+    boost/thread/thread.hpp
+    boost/variant.hpp
+    boost/variant/apply_visitor.hpp
+    boost/variant/static_visitor.hpp
+)
+
+for BOOST_INCLUDE in $(git grep '^#include <boost/' -- "*.cpp" "*.h" | cut -f2 -d: | cut -f2 -d'<' | cut -f1 -d'>' | sort -u); do
+    IS_EXPECTED_INCLUDE=0
+    for EXPECTED_BOOST_INCLUDE in "${EXPECTED_BOOST_INCLUDES[@]}"; do
+        if [[ "${BOOST_INCLUDE}" == "${EXPECTED_BOOST_INCLUDE}" ]]; then
+            IS_EXPECTED_INCLUDE=1
+            break
+        fi
+    done
+    if [[ ${IS_EXPECTED_INCLUDE} == 0 ]]; then
+        EXIT_CODE=1
+        echo "A new Boost dependency in the form of \"${BOOST_INCLUDE}\" appears to have been introduced:"
+        git grep "${BOOST_INCLUDE}" -- "*.cpp" "*.h"
+        echo
+    fi
+done
+
+for EXPECTED_BOOST_INCLUDE in "${EXPECTED_BOOST_INCLUDES[@]}"; do
+    if ! git grep -q "^#include <${EXPECTED_BOOST_INCLUDE}>" -- "*.cpp" "*.h"; then
+        echo "Good job! The Boost dependency \"${EXPECTED_BOOST_INCLUDE}\" is no longer used."
+        echo "Please remove it from EXPECTED_BOOST_INCLUDES in $0"
+        echo "to make sure this dependency is not accidentally reintroduced."
+        echo
+        EXIT_CODE=1
+    fi
+done
+
+QUOTE_SYNTAX_INCLUDES=$(git grep '^#include "' -- "*.cpp" "*.h" | grep -Ev "${IGNORE_REGEXP}")
+if [[ ${QUOTE_SYNTAX_INCLUDES} != "" ]]; then
+    echo "Please use bracket syntax includes (\"#include <foo.h>\") instead of quote syntax includes:"
+    echo "${QUOTE_SYNTAX_INCLUDES}"
+    echo
+    EXIT_CODE=1
+fi
+
+exit ${EXIT_CODE}
diff --git a/test/lint/lint-locale-dependence.sh b/test/lint/lint-locale-dependence.sh
new file mode 100755
index 0000000000..cbe1143bd0
--- /dev/null
+++ b/test/lint/lint-locale-dependence.sh
@@ -0,0 +1,230 @@
+#!/usr/bin/env bash
+
+export LC_ALL=C
+KNOWN_VIOLATIONS=(
+    "src/base58.cpp:.*isspace"
+    "src/bitcoin-tx.cpp.*stoul"
+    "src/bitcoin-tx.cpp.*trim_right"
+    "src/bitcoin-tx.cpp:.*atoi"
+    "src/core_read.cpp.*is_digit"
+    "src/dbwrapper.cpp.*stoul"
+    "src/dbwrapper.cpp:.*vsnprintf"
+    "src/httprpc.cpp.*trim"
+    "src/init.cpp:.*atoi"
+    "src/netbase.cpp.*to_lower"
+    "src/qt/rpcconsole.cpp:.*atoi"
+    "src/qt/rpcconsole.cpp:.*isdigit"
+    "src/rest.cpp:.*strtol"
+    "src/rpc/server.cpp.*to_upper"
+    "src/test/dbwrapper_tests.cpp:.*snprintf"
+    "src/test/getarg_tests.cpp.*split"
+    "src/torcontrol.cpp:.*atoi"
+    "src/torcontrol.cpp:.*strtol"
+    "src/uint256.cpp:.*isspace"
+    "src/uint256.cpp:.*tolower"
+    "src/util.cpp:.*atoi"
+    "src/util.cpp:.*fprintf"
+    "src/util.cpp:.*tolower"
+    "src/utilmoneystr.cpp:.*isdigit"
+    "src/utilmoneystr.cpp:.*isspace"
+    "src/utilstrencodings.cpp:.*atoi"
+    "src/utilstrencodings.cpp:.*isspace"
+    "src/utilstrencodings.cpp:.*strtol"
+    "src/utilstrencodings.cpp:.*strtoll"
+    "src/utilstrencodings.cpp:.*strtoul"
+    "src/utilstrencodings.cpp:.*strtoull"
+    "src/utilstrencodings.h:.*atoi"
+)
+
+REGEXP_IGNORE_EXTERNAL_DEPENDENCIES="^src/(crypto/ctaes/|leveldb/|secp256k1/|tinyformat.h|univalue/)"
+
+LOCALE_DEPENDENT_FUNCTIONS=(
+    alphasort    # LC_COLLATE (via strcoll)
+    asctime      # LC_TIME (directly)
+    asprintf     # (via vasprintf)
+    atof         # LC_NUMERIC (via strtod)
+    atoi         # LC_NUMERIC (via strtol)
+    atol         # LC_NUMERIC (via strtol)
+    atoll        # (via strtoll)
+    atoq
+    btowc        # LC_CTYPE (directly)
+    ctime        # (via asctime or localtime)
+    dprintf      # (via vdprintf)
+    fgetwc
+    fgetws
+    fold_case    # boost::locale::fold_case
+    fprintf      # (via vfprintf)
+    fputwc
+    fputws
+    fscanf       # (via __vfscanf)
+    fwprintf     # (via __vfwprintf)
+    getdate      # via __getdate_r => isspace // __localtime_r
+    getwc
+    getwchar
+    is_digit     # boost::algorithm::is_digit
+    is_space     # boost::algorithm::is_space
+    isalnum      # LC_CTYPE
+    isalpha      # LC_CTYPE
+    isblank      # LC_CTYPE
+    iscntrl      # LC_CTYPE
+    isctype      # LC_CTYPE
+    isdigit      # LC_CTYPE
+    isgraph      # LC_CTYPE
+    islower      # LC_CTYPE
+    isprint      # LC_CTYPE
+    ispunct      # LC_CTYPE
+    isspace      # LC_CTYPE
+    isupper      # LC_CTYPE
+    iswalnum     # LC_CTYPE
+    iswalpha     # LC_CTYPE
+    iswblank     # LC_CTYPE
+    iswcntrl     # LC_CTYPE
+    iswctype     # LC_CTYPE
+    iswdigit     # LC_CTYPE
+    iswgraph     # LC_CTYPE
+    iswlower     # LC_CTYPE
+    iswprint     # LC_CTYPE
+    iswpunct     # LC_CTYPE
+    iswspace     # LC_CTYPE
+    iswupper     # LC_CTYPE
+    iswxdigit    # LC_CTYPE
+    isxdigit     # LC_CTYPE
+    localeconv   # LC_NUMERIC + LC_MONETARY
+    mblen        # LC_CTYPE
+    mbrlen
+    mbrtowc
+    mbsinit
+    mbsnrtowcs
+    mbsrtowcs
+    mbstowcs     # LC_CTYPE
+    mbtowc       # LC_CTYPE
+    mktime
+    normalize    # boost::locale::normalize
+#   printf       # LC_NUMERIC
+    putwc
+    putwchar
+    scanf        # LC_NUMERIC
+    setlocale
+    snprintf
+    sprintf
+    sscanf
+    stod
+    stof
+    stoi
+    stol
+    stold
+    stoll
+    stoul
+    stoull
+    strcasecmp
+    strcasestr
+    strcoll      # LC_COLLATE
+#   strerror
+    strfmon
+    strftime     # LC_TIME
+    strncasecmp
+    strptime
+    strtod       # LC_NUMERIC
+    strtof
+    strtoimax
+    strtol       # LC_NUMERIC
+    strtold
+    strtoll
+    strtoq
+    strtoul      # LC_NUMERIC
+    strtoull
+    strtoumax
+    strtouq
+    strxfrm      # LC_COLLATE
+    swprintf
+    to_lower     # boost::locale::to_lower
+    to_title     # boost::locale::to_title
+    to_upper     # boost::locale::to_upper
+    tolower      # LC_CTYPE
+    toupper      # LC_CTYPE
+    towctrans
+    towlower     # LC_CTYPE
+    towupper     # LC_CTYPE
+    trim         # boost::algorithm::trim
+    trim_left    # boost::algorithm::trim_left
+    trim_right   # boost::algorithm::trim_right
+    ungetwc
+    vasprintf
+    vdprintf
+    versionsort
+    vfprintf
+    vfscanf
+    vfwprintf
+    vprintf
+    vscanf
+    vsnprintf
+    vsprintf
+    vsscanf
+    vswprintf
+    vwprintf
+    wcrtomb
+    wcscasecmp
+    wcscoll      # LC_COLLATE
+    wcsftime     # LC_TIME
+    wcsncasecmp
+    wcsnrtombs
+    wcsrtombs
+    wcstod       # LC_NUMERIC
+    wcstof
+    wcstoimax
+    wcstol       # LC_NUMERIC
+    wcstold
+    wcstoll
+    wcstombs     # LC_CTYPE
+    wcstoul      # LC_NUMERIC
+    wcstoull
+    wcstoumax
+    wcswidth
+    wcsxfrm      # LC_COLLATE
+    wctob
+    wctomb       # LC_CTYPE
+    wctrans
+    wctype
+    wcwidth
+    wprintf
+)
+
+function join_array {
+    local IFS="$1"
+    shift
+    echo "$*"
+}
+
+REGEXP_IGNORE_KNOWN_VIOLATIONS=$(join_array "|" "${KNOWN_VIOLATIONS[@]}")
+
+# Invoke "git grep" only once in order to minimize run-time
+REGEXP_LOCALE_DEPENDENT_FUNCTIONS=$(join_array "|" "${LOCALE_DEPENDENT_FUNCTIONS[@]}")
+GIT_GREP_OUTPUT=$(git grep -E "[^a-zA-Z0-9_\`'\"<>](${REGEXP_LOCALE_DEPENDENT_FUNCTIONS}(|_r|_s))[^a-zA-Z0-9_\`'\"<>]" -- "*.cpp" "*.h")
+
+EXIT_CODE=0
+for LOCALE_DEPENDENT_FUNCTION in "${LOCALE_DEPENDENT_FUNCTIONS[@]}"; do
+    MATCHES=$(grep -E "[^a-zA-Z0-9_\`'\"<>]${LOCALE_DEPENDENT_FUNCTION}(|_r|_s)[^a-zA-Z0-9_\`'\"<>]" <<< "${GIT_GREP_OUTPUT}" | \
+        grep -vE "\.(c|cpp|h):\s*(//|\*|/\*|\").*${LOCALE_DEPENDENT_FUNCTION}" | \
+        grep -vE 'fprintf\(.*(stdout|stderr)')
+    if [[ ${REGEXP_IGNORE_EXTERNAL_DEPENDENCIES} != "" ]]; then
+        MATCHES=$(grep -vE "${REGEXP_IGNORE_EXTERNAL_DEPENDENCIES}" <<< "${MATCHES}")
+    fi
+    if [[ ${REGEXP_IGNORE_KNOWN_VIOLATIONS} != "" ]]; then
+        MATCHES=$(grep -vE "${REGEXP_IGNORE_KNOWN_VIOLATIONS}" <<< "${MATCHES}")
+    fi
+    if [[ ${MATCHES} != "" ]]; then
+        echo "The locale dependent function ${LOCALE_DEPENDENT_FUNCTION}(...) appears to be used:"
+        echo "${MATCHES}"
+        echo
+        EXIT_CODE=1
+    fi
+done
+if [[ ${EXIT_CODE} != 0 ]]; then
+    echo "Unnecessary locale dependence can cause bugs that are very"
+    echo "tricky to isolate and fix. Please avoid using locale dependent"
+    echo "functions if possible."
+    echo
+    echo "Advice not applicable in this specific case? Add an exception"
+    echo "by updating the ignore list in $0"
+fi
+exit ${EXIT_CODE}
diff --git a/test/lint/lint-logs.sh b/test/lint/lint-logs.sh
new file mode 100755
index 0000000000..1afd4cfc1a
--- /dev/null
+++ b/test/lint/lint-logs.sh
@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2018 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Check that all logs are terminated with '\n'
+#
+# Some logs are continued over multiple lines. They should be explicitly
+# commented with \* Continued *\
+#
+# There are some instances of LogPrintf() in comments. Those can be
+# ignored
+
+export LC_ALL=C
+UNTERMINATED_LOGS=$(git grep --extended-regexp "LogPrintf?\(" -- "*.cpp" | \
+    grep -v '\\n"' | \
+    grep -v "/\* Continued \*/" | \
+    grep -v "LogPrint()" | \
+    grep -v "LogPrintf()")
+if [[ ${UNTERMINATED_LOGS} != "" ]]; then
+    echo "All calls to LogPrintf() and LogPrint() should be terminated with \\n"
+    echo
+    echo "${UNTERMINATED_LOGS}"
+    exit 1
+fi
diff --git a/test/lint/lint-python-shebang.sh b/test/lint/lint-python-shebang.sh
new file mode 100755
index 0000000000..4ff87f0bf7
--- /dev/null
+++ b/test/lint/lint-python-shebang.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Shebang must use python3 (not python or python2)
+
+export LC_ALL=C
+EXIT_CODE=0
+for PYTHON_FILE in $(git ls-files -- "*.py"); do
+    if [[ $(head -c 2 "${PYTHON_FILE}") == "#!" &&
+          $(head -n 1 "${PYTHON_FILE}") != "#!/usr/bin/env python3" ]]; then
+        echo "Missing shebang \"#!/usr/bin/env python3\" in ${PYTHON_FILE} (do not use python or python2)"
+        EXIT_CODE=1
+    fi
+done
+exit ${EXIT_CODE}
diff --git a/test/lint/lint-python-utf8-encoding.sh b/test/lint/lint-python-utf8-encoding.sh
new file mode 100755
index 0000000000..14183a5ccf
--- /dev/null
+++ b/test/lint/lint-python-utf8-encoding.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2018 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Make sure we explicitly open all text files using UTF-8 (or ASCII) encoding to
+# avoid potential issues on the BSDs where the locale is not always set.
+
+export LC_ALL=C
+EXIT_CODE=0
+OUTPUT=$(git grep " open(" -- "*.py" | grep -vE "encoding=.(ascii|utf8|utf-8)." | grep -vE "open\([^,]*, ['\"][^'\"]*b[^'\"]*['\"]")
+if [[ ${OUTPUT} != "" ]]; then
+    echo "Python's open(...) seems to be used to open text files without explicitly"
+    echo "specifying encoding=\"utf8\":"
+    echo
+    echo "${OUTPUT}"
+    EXIT_CODE=1
+fi
+exit ${EXIT_CODE}
diff --git a/test/lint/lint-python.sh b/test/lint/lint-python.sh
new file mode 100755
index 0000000000..d9d46d86d5
--- /dev/null
+++ b/test/lint/lint-python.sh
@@ -0,0 +1,80 @@
+#!/bin/sh
+#
+# Copyright (c) 2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Check for specified flake8 warnings in python files.
+
+export LC_ALL=C
+
+# E101 indentation contains mixed spaces and tabs
+# E112 expected an indented block
+# E113 unexpected indentation
+# E115 expected an indented block (comment)
+# E116 unexpected indentation (comment)
+# E125 continuation line with same indent as next logical line
+# E129 visually indented line with same indent as next logical line
+# E131 continuation line unaligned for hanging indent
+# E133 closing bracket is missing indentation
+# E223 tab before operator
+# E224 tab after operator
+# E242 tab after ','
+# E266 too many leading '#' for block comment
+# E271 multiple spaces after keyword
+# E272 multiple spaces before keyword
+# E273 tab after keyword
+# E274 tab before keyword
+# E275 missing whitespace after keyword
+# E304 blank lines found after function decorator
+# E306 expected 1 blank line before a nested definition
+# E401 multiple imports on one line
+# E402 module level import not at top of file
+# E502 the backslash is redundant between brackets
+# E701 multiple statements on one line (colon)
+# E702 multiple statements on one line (semicolon)
+# E703 statement ends with a semicolon
+# E714 test for object identity should be "is not"
+# E721 do not compare types, use "isinstance()"
+# E741 do not use variables named "l", "O", or "I"
+# E742 do not define classes named "l", "O", or "I"
+# E743 do not define functions named "l", "O", or "I"
+# E901 SyntaxError: invalid syntax
+# E902 TokenError: EOF in multi-line string
+# F401 module imported but unused
+# F402 import module from line N shadowed by loop variable
+# F404 future import(s) name after other statements
+# F406 "from module import *" only allowed at module level
+# F407 an undefined __future__ feature name was imported
+# F601 dictionary key name repeated with different values
+# F602 dictionary key variable name repeated with different values
+# F621 too many expressions in an assignment with star-unpacking
+# F622 two or more starred expressions in an assignment (a, *b, *c = d)
+# F631 assertion test is a tuple, which are always True
+# F701 a break statement outside of a while or for loop
+# F702 a continue statement outside of a while or for loop
+# F703 a continue statement in a finally block in a loop
+# F704 a yield or yield from statement outside of a function
+# F705 a return statement with arguments inside a generator
+# F706 a return statement outside of a function/method
+# F707 an except: block as not the last exception handler
+# F811 redefinition of unused name from line N
+# F812 list comprehension redefines 'foo' from line N
+# F821 undefined name 'Foo'
+# F822 undefined name name in __all__
+# F823 local variable name … referenced before assignment
+# F831 duplicate argument name in function definition
+# F841 local variable 'foo' is assigned to but never used
+# W191 indentation contains tabs
+# W291 trailing whitespace
+# W292 no newline at end of file
+# W293 blank line contains whitespace
+# W504 line break after binary operator
+# W601 .has_key() is deprecated, use "in"
+# W602 deprecated form of raising exception
+# W603 "<>" is deprecated, use "!="
+# W604 backticks are deprecated, use "repr()"
+# W605 invalid escape sequence "x"
+# W606 'async' and 'await' are reserved keywords starting with Python 3.7
+
+flake8 --ignore=B,C,E,F,I,N,W --select=E101,E112,E113,E115,E116,E125,E129,E131,E133,E223,E224,E242,E266,E271,E272,E273,E274,E275,E304,E306,E401,E402,E502,E701,E702,E703,E714,E721,E741,E742,E743,F401,E901,E902,F402,F404,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F821,F822,F823,F831,F841,W191,W291,W292,W293,W504,W601,W602,W603,W604,W605,W606 .
diff --git a/test/lint/lint-shell-locale.sh b/test/lint/lint-shell-locale.sh
new file mode 100755
index 0000000000..242b27c763
--- /dev/null
+++ b/test/lint/lint-shell-locale.sh
@@ -0,0 +1,24 @@
+#!/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.
+#
+# Make sure all shell scripts:
+# a.) explicitly opt out of locale dependence using "export LC_ALL=C", or
+# b.) explicitly opt in to locale dependence using the annotation below.
+
+export LC_ALL=C
+
+EXIT_CODE=0
+for SHELL_SCRIPT in $(git ls-files -- "*.sh" | grep -vE "src/(secp256k1|univalue)/"); do
+    if grep -q "# This script is intentionally locale dependent by not setting \"export LC_ALL=C\"" "${SHELL_SCRIPT}"; then
+        continue
+    fi
+    FIRST_NON_COMMENT_LINE=$(grep -vE '^(#.*|)$' "${SHELL_SCRIPT}" | head -1)
+    if [[ ${FIRST_NON_COMMENT_LINE} != "export LC_ALL=C" ]]; then
+        echo "Missing \"export LC_ALL=C\" (to avoid locale dependence) as first non-comment non-empty line in ${SHELL_SCRIPT}"
+        EXIT_CODE=1
+    fi
+done
+exit ${EXIT_CODE}
diff --git a/test/lint/lint-shell.sh b/test/lint/lint-shell.sh
new file mode 100755
index 0000000000..e2ccdb5165
--- /dev/null
+++ b/test/lint/lint-shell.sh
@@ -0,0 +1,31 @@
+#!/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.
+#
+# Check for shellcheck warnings in shell scripts.
+
+# This script is intentionally locale dependent by not setting "export LC_ALL=C"
+# to allow running certain versions of shellcheck that core dump when LC_ALL=C
+# is set.
+
+# Disabled warnings:
+# SC2001: See if you can use ${variable//search/replace} instead.
+# SC2004: $/${} is unnecessary on arithmetic variables.
+# SC2005: Useless echo? Instead of 'echo $(cmd)', just use 'cmd'.
+# SC2006: Use $(..) instead of legacy `..`.
+# SC2016: Expressions don't expand in single quotes, use double quotes for that.
+# SC2028: echo won't expand escape sequences. Consider printf.
+# SC2046: Quote this to prevent word splitting.
+# SC2048: Use "$@" (with quotes) to prevent whitespace problems.
+# SC2066: Since you double quoted this, it will not word split, and the loop will only run once.
+# SC2086: Double quote to prevent globbing and word splitting.
+# SC2116: Useless echo? Instead of 'cmd $(echo foo)', just use 'cmd foo'.
+# SC2148: Tips depend on target shell and yours is unknown. Add a shebang.
+# SC2162: read without -r will mangle backslashes.
+# SC2166: Prefer [ p ] && [ q ] as [ p -a q ] is not well defined.
+# SC2166: Prefer [ p ] || [ q ] as [ p -o q ] is not well defined.
+# SC2181: Check exit code directly with e.g. 'if mycmd;', not indirectly with $?.
+shellcheck -e SC2001,SC2004,SC2005,SC2006,SC2016,SC2028,SC2046,SC2048,SC2066,SC2086,SC2116,SC2148,SC2162,SC2166,SC2181 \
+    $(git ls-files -- "*.sh" | grep -vE 'src/(secp256k1|univalue)/')
diff --git a/test/lint/lint-tests.sh b/test/lint/lint-tests.sh
new file mode 100755
index 0000000000..35d11023eb
--- /dev/null
+++ b/test/lint/lint-tests.sh
@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2018 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Check the test suite naming conventions
+
+export LC_ALL=C
+EXIT_CODE=0
+
+NAMING_INCONSISTENCIES=$(git grep -E '^BOOST_FIXTURE_TEST_SUITE\(' -- \
+    "src/test/**.cpp" "src/wallet/test/**.cpp" | \
+    grep -vE '/(.*?)\.cpp:BOOST_FIXTURE_TEST_SUITE\(\1, .*\)$')
+if [[ ${NAMING_INCONSISTENCIES} != "" ]]; then
+    echo "The test suite in file src/test/foo_tests.cpp should be named"
+    echo "\"foo_tests\". Please make sure the following test suites follow"
+    echo "that convention:"
+    echo
+    echo "${NAMING_INCONSISTENCIES}"
+    EXIT_CODE=1
+fi
+
+TEST_SUITE_NAME_COLLISSIONS=$(git grep -E '^BOOST_FIXTURE_TEST_SUITE\(' -- \
+    "src/test/**.cpp" "src/wallet/test/**.cpp" | cut -f2 -d'(' | cut -f1 -d, | \
+    sort | uniq -d)
+if [[ ${TEST_SUITE_NAME_COLLISSIONS} != "" ]]; then
+    echo "Test suite names must be unique. The following test suite names"
+    echo "appear to be used more than once:"
+    echo
+    echo "${TEST_SUITE_NAME_COLLISSIONS}"
+    EXIT_CODE=1
+fi
+
+exit ${EXIT_CODE}
diff --git a/test/lint/lint-whitespace.sh b/test/lint/lint-whitespace.sh
new file mode 100755
index 0000000000..beb7ec42f4
--- /dev/null
+++ b/test/lint/lint-whitespace.sh
@@ -0,0 +1,113 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Check for new lines in diff that introduce trailing whitespace.
+
+# We can't run this check unless we know the commit range for the PR.
+
+export LC_ALL=C
+while getopts "?" opt; do
+  case $opt in
+    ?)
+      echo "Usage: .lint-whitespace.sh [N]"
+      echo "       TRAVIS_COMMIT_RANGE='<commit range>' .lint-whitespace.sh"
+      echo "       .lint-whitespace.sh -?"
+      echo "Checks unstaged changes, the previous N commits, or a commit range."
+      echo "TRAVIS_COMMIT_RANGE='47ba2c3...ee50c9e' .lint-whitespace.sh"
+      exit 0
+    ;;
+  esac
+done
+
+if [ -z "${TRAVIS_COMMIT_RANGE}" ]; then
+  if [ "$1" ]; then
+    TRAVIS_COMMIT_RANGE="HEAD~$1...HEAD"
+  else
+    TRAVIS_COMMIT_RANGE="HEAD"
+  fi
+fi
+
+showdiff() {
+  if ! git diff -U0 "${TRAVIS_COMMIT_RANGE}" -- "." ":(exclude)depends/patches/" ":(exclude)src/leveldb/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" ":(exclude)doc/release-notes/"; then
+    echo "Failed to get a diff"
+    exit 1
+  fi
+}
+
+showcodediff() {
+  if ! git diff -U0 "${TRAVIS_COMMIT_RANGE}" -- *.cpp *.h *.md *.py *.sh ":(exclude)src/leveldb/" ":(exclude)src/secp256k1/" ":(exclude)src/univalue/" ":(exclude)doc/release-notes/"; then
+    echo "Failed to get a diff"
+    exit 1
+  fi
+}
+
+RET=0
+
+# Check if trailing whitespace was found in the diff.
+if showdiff | grep -E -q '^\+.*\s+$'; then
+  echo "This diff appears to have added new lines with trailing whitespace."
+  echo "The following changes were suspected:"
+  FILENAME=""
+  SEEN=0
+  SEENLN=0
+  while read -r line; do
+    if [[ "$line" =~ ^diff ]]; then
+      FILENAME="$line"
+      SEEN=0
+    elif [[ "$line" =~ ^@@ ]]; then
+      LINENUMBER="$line"
+      SEENLN=0
+    else
+      if [ "$SEEN" -eq 0 ]; then
+        # The first time a file is seen with trailing whitespace, we print the
+        # filename (preceded by a newline).
+        echo
+        echo "$FILENAME"
+        SEEN=1
+      fi
+      if [ "$SEENLN" -eq 0 ]; then
+        echo "$LINENUMBER"
+        SEENLN=1
+      fi
+      echo "$line"
+    fi
+  done < <(showdiff | grep -E '^(diff --git |@@|\+.*\s+$)')
+  RET=1
+fi
+
+# Check if tab characters were found in the diff.
+if showcodediff | perl -nle '$MATCH++ if m{^\+.*\t}; END{exit 1 unless $MATCH>0}' > /dev/null; then
+  echo "This diff appears to have added new lines with tab characters instead of spaces."
+  echo "The following changes were suspected:"
+  FILENAME=""
+  SEEN=0
+  SEENLN=0
+  while read -r line; do
+    if [[ "$line" =~ ^diff ]]; then
+      FILENAME="$line"
+      SEEN=0
+    elif [[ "$line" =~ ^@@ ]]; then
+      LINENUMBER="$line"
+      SEENLN=0
+    else
+      if [ "$SEEN" -eq 0 ]; then
+        # The first time a file is seen with a tab character, we print the
+        # filename (preceded by a newline).
+        echo
+        echo "$FILENAME"
+        SEEN=1
+      fi
+      if [ "$SEENLN" -eq 0 ]; then
+        echo "$LINENUMBER"
+        SEENLN=1
+      fi
+      echo "$line"
+    fi
+  done < <(showcodediff | perl -nle 'print if m{^(diff --git |@@|\+.*\t)}')
+  RET=1
+fi
+
+exit $RET