[PATCH 1/1] scripts: add checkkconfigsymbols.py
Ilias Apalodimas
ilias.apalodimas at linaro.org
Wed Feb 25 16:41:08 CET 2026
On Wed, 25 Feb 2026 at 15:10, Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
> Add checkkconfigsymbols.py from Linux 7.0-rc1 (unchanged since v6.2).
> This tool allows to identify the usage of symbols that are not defined
> in Kconfig.
>
> Suggested-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
Acked-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> scripts/checkkconfigsymbols.py | 482 +++++++++++++++++++++++++++++++++
> 1 file changed, 482 insertions(+)
> create mode 100755 scripts/checkkconfigsymbols.py
>
> diff --git a/scripts/checkkconfigsymbols.py b/scripts/checkkconfigsymbols.py
> new file mode 100755
> index 00000000000..36c920e7131
> --- /dev/null
> +++ b/scripts/checkkconfigsymbols.py
> @@ -0,0 +1,482 @@
> +#!/usr/bin/env python3
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +"""Find Kconfig symbols that are referenced but not defined."""
> +
> +# (c) 2014-2017 Valentin Rothberg <valentinrothberg at gmail.com>
> +# (c) 2014 Stefan Hengelein <stefan.hengelein at fau.de>
> +#
> +
> +
> +import argparse
> +import difflib
> +import os
> +import re
> +import signal
> +import subprocess
> +import sys
> +from multiprocessing import Pool, cpu_count
> +
> +
> +# regex expressions
> +OPERATORS = r"&|\(|\)|\||\!"
> +SYMBOL = r"(?:\w*[A-Z0-9]\w*){2,}"
> +DEF = r"^\s*(?:menu){,1}config\s+(" + SYMBOL + r")\s*"
> +EXPR = r"(?:" + OPERATORS + r"|\s|" + SYMBOL + r")+"
> +DEFAULT = r"default\s+.*?(?:if\s.+){,1}"
> +STMT = r"^\s*(?:if|select|imply|depends\s+on|(?:" + DEFAULT + r"))\s+" + EXPR
> +SOURCE_SYMBOL = r"(?:\W|\b)+[D]{,1}CONFIG_(" + SYMBOL + r")"
> +
> +# regex objects
> +REGEX_FILE_KCONFIG = re.compile(r".*Kconfig[\.\w+\-]*$")
> +REGEX_SYMBOL = re.compile(r'(?!\B)' + SYMBOL + r'(?!\B)')
> +REGEX_SOURCE_SYMBOL = re.compile(SOURCE_SYMBOL)
> +REGEX_KCONFIG_DEF = re.compile(DEF)
> +REGEX_KCONFIG_EXPR = re.compile(EXPR)
> +REGEX_KCONFIG_STMT = re.compile(STMT)
> +REGEX_FILTER_SYMBOLS = re.compile(r"[A-Za-z0-9]$")
> +REGEX_NUMERIC = re.compile(r"0[xX][0-9a-fA-F]+|[0-9]+")
> +REGEX_QUOTES = re.compile("(\"(.*?)\")")
> +
> +
> +def parse_options():
> + """The user interface of this module."""
> + usage = "Run this tool to detect Kconfig symbols that are referenced but " \
> + "not defined in Kconfig. If no option is specified, " \
> + "checkkconfigsymbols defaults to check your current tree. " \
> + "Please note that specifying commits will 'git reset --hard\' " \
> + "your current tree! You may save uncommitted changes to avoid " \
> + "losing data."
> +
> + parser = argparse.ArgumentParser(description=usage)
> +
> + parser.add_argument('-c', '--commit', dest='commit', action='store',
> + default="",
> + help="check if the specified commit (hash) introduces "
> + "undefined Kconfig symbols")
> +
> + parser.add_argument('-d', '--diff', dest='diff', action='store',
> + default="",
> + help="diff undefined symbols between two commits "
> + "(e.g., -d commmit1..commit2)")
> +
> + parser.add_argument('-f', '--find', dest='find', action='store_true',
> + default=False,
> + help="find and show commits that may cause symbols to be "
> + "missing (required to run with --diff)")
> +
> + parser.add_argument('-i', '--ignore', dest='ignore', action='store',
> + default="",
> + help="ignore files matching this Python regex "
> + "(e.g., -i '.*defconfig')")
> +
> + parser.add_argument('-s', '--sim', dest='sim', action='store', default="",
> + help="print a list of max. 10 string-similar symbols")
> +
> + parser.add_argument('--force', dest='force', action='store_true',
> + default=False,
> + help="reset current Git tree even when it's dirty")
> +
> + parser.add_argument('--no-color', dest='color', action='store_false',
> + default=True,
> + help="don't print colored output (default when not "
> + "outputting to a terminal)")
> +
> + args = parser.parse_args()
> +
> + if args.commit and args.diff:
> + sys.exit("Please specify only one option at once.")
> +
> + if args.diff and not re.match(r"^[\w\-\.\^]+\.\.[\w\-\.\^]+$", args.diff):
> + sys.exit("Please specify valid input in the following format: "
> + "\'commit1..commit2\'")
> +
> + if args.commit or args.diff:
> + if not args.force and tree_is_dirty():
> + sys.exit("The current Git tree is dirty (see 'git status'). "
> + "Running this script may\ndelete important data since it "
> + "calls 'git reset --hard' for some performance\nreasons. "
> + " Please run this script in a clean Git tree or pass "
> + "'--force' if you\nwant to ignore this warning and "
> + "continue.")
> +
> + if args.commit:
> + if args.commit.startswith('HEAD'):
> + sys.exit("The --commit option can't use the HEAD ref")
> +
> + args.find = False
> +
> + if args.ignore:
> + try:
> + re.match(args.ignore, "this/is/just/a/test.c")
> + except:
> + sys.exit("Please specify a valid Python regex.")
> +
> + return args
> +
> +
> +def print_undefined_symbols():
> + """Main function of this module."""
> + args = parse_options()
> +
> + global COLOR
> + COLOR = args.color and sys.stdout.isatty()
> +
> + if args.sim and not args.commit and not args.diff:
> + sims = find_sims(args.sim, args.ignore)
> + if sims:
> + print("%s: %s" % (yel("Similar symbols"), ', '.join(sims)))
> + else:
> + print("%s: no similar symbols found" % yel("Similar symbols"))
> + sys.exit(0)
> +
> + # dictionary of (un)defined symbols
> + defined = {}
> + undefined = {}
> +
> + if args.commit or args.diff:
> + head = get_head()
> +
> + # get commit range
> + commit_a = None
> + commit_b = None
> + if args.commit:
> + commit_a = args.commit + "~"
> + commit_b = args.commit
> + elif args.diff:
> + split = args.diff.split("..")
> + commit_a = split[0]
> + commit_b = split[1]
> + undefined_a = {}
> + undefined_b = {}
> +
> + # get undefined items before the commit
> + reset(commit_a)
> + undefined_a, _ = check_symbols(args.ignore)
> +
> + # get undefined items for the commit
> + reset(commit_b)
> + undefined_b, defined = check_symbols(args.ignore)
> +
> + # report cases that are present for the commit but not before
> + for symbol in sorted(undefined_b):
> + # symbol has not been undefined before
> + if symbol not in undefined_a:
> + files = sorted(undefined_b.get(symbol))
> + undefined[symbol] = files
> + # check if there are new files that reference the undefined symbol
> + else:
> + files = sorted(undefined_b.get(symbol) -
> + undefined_a.get(symbol))
> + if files:
> + undefined[symbol] = files
> +
> + # reset to head
> + reset(head)
> +
> + # default to check the entire tree
> + else:
> + undefined, defined = check_symbols(args.ignore)
> +
> + # now print the output
> + for symbol in sorted(undefined):
> + print(red(symbol))
> +
> + files = sorted(undefined.get(symbol))
> + print("%s: %s" % (yel("Referencing files"), ", ".join(files)))
> +
> + sims = find_sims(symbol, args.ignore, defined)
> + sims_out = yel("Similar symbols")
> + if sims:
> + print("%s: %s" % (sims_out, ', '.join(sims)))
> + else:
> + print("%s: %s" % (sims_out, "no similar symbols found"))
> +
> + if args.find:
> + print("%s:" % yel("Commits changing symbol"))
> + commits = find_commits(symbol, args.diff)
> + if commits:
> + for commit in commits:
> + commit = commit.split(" ", 1)
> + print("\t- %s (\"%s\")" % (yel(commit[0]), commit[1]))
> + else:
> + print("\t- no commit found")
> + print() # new line
> +
> +
> +def reset(commit):
> + """Reset current git tree to %commit."""
> + execute(["git", "reset", "--hard", commit])
> +
> +
> +def yel(string):
> + """
> + Color %string yellow.
> + """
> + return "\033[33m%s\033[0m" % string if COLOR else string
> +
> +
> +def red(string):
> + """
> + Color %string red.
> + """
> + return "\033[31m%s\033[0m" % string if COLOR else string
> +
> +
> +def execute(cmd):
> + """Execute %cmd and return stdout. Exit in case of error."""
> + try:
> + stdout = subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=False)
> + stdout = stdout.decode(errors='replace')
> + except subprocess.CalledProcessError as fail:
> + exit(fail)
> + return stdout
> +
> +
> +def find_commits(symbol, diff):
> + """Find commits changing %symbol in the given range of %diff."""
> + commits = execute(["git", "log", "--pretty=oneline",
> + "--abbrev-commit", "-G",
> + symbol, diff])
> + return [x for x in commits.split("\n") if x]
> +
> +
> +def tree_is_dirty():
> + """Return true if the current working tree is dirty (i.e., if any file has
> + been added, deleted, modified, renamed or copied but not committed)."""
> + stdout = execute(["git", "status", "--porcelain"])
> + for line in stdout:
> + if re.findall(r"[URMADC]{1}", line[:2]):
> + return True
> + return False
> +
> +
> +def get_head():
> + """Return commit hash of current HEAD."""
> + stdout = execute(["git", "rev-parse", "HEAD"])
> + return stdout.strip('\n')
> +
> +
> +def partition(lst, size):
> + """Partition list @lst into eveni-sized lists of size @size."""
> + return [lst[i::size] for i in range(size)]
> +
> +
> +def init_worker():
> + """Set signal handler to ignore SIGINT."""
> + signal.signal(signal.SIGINT, signal.SIG_IGN)
> +
> +
> +def find_sims(symbol, ignore, defined=[]):
> + """Return a list of max. ten Kconfig symbols that are string-similar to
> + @symbol."""
> + if defined:
> + return difflib.get_close_matches(symbol, set(defined), 10)
> +
> + pool = Pool(cpu_count(), init_worker)
> + kfiles = []
> + for gitfile in get_files():
> + if REGEX_FILE_KCONFIG.match(gitfile):
> + kfiles.append(gitfile)
> +
> + arglist = []
> + for part in partition(kfiles, cpu_count()):
> + arglist.append((part, ignore))
> +
> + for res in pool.map(parse_kconfig_files, arglist):
> + defined.extend(res[0])
> +
> + return difflib.get_close_matches(symbol, set(defined), 10)
> +
> +
> +def get_files():
> + """Return a list of all files in the current git directory."""
> + # use 'git ls-files' to get the worklist
> + stdout = execute(["git", "ls-files"])
> + if len(stdout) > 0 and stdout[-1] == "\n":
> + stdout = stdout[:-1]
> +
> + files = []
> + for gitfile in stdout.rsplit("\n"):
> + if ".git" in gitfile or "ChangeLog" in gitfile or \
> + ".log" in gitfile or os.path.isdir(gitfile) or \
> + gitfile.startswith("tools/"):
> + continue
> + files.append(gitfile)
> + return files
> +
> +
> +def check_symbols(ignore):
> + """Find undefined Kconfig symbols and return a dict with the symbol as key
> + and a list of referencing files as value. Files matching %ignore are not
> + checked for undefined symbols."""
> + pool = Pool(cpu_count(), init_worker)
> + try:
> + return check_symbols_helper(pool, ignore)
> + except KeyboardInterrupt:
> + pool.terminate()
> + pool.join()
> + sys.exit(1)
> +
> +
> +def check_symbols_helper(pool, ignore):
> + """Helper method for check_symbols(). Used to catch keyboard interrupts in
> + check_symbols() in order to properly terminate running worker processes."""
> + source_files = []
> + kconfig_files = []
> + defined_symbols = []
> + referenced_symbols = dict() # {file: [symbols]}
> +
> + for gitfile in get_files():
> + if REGEX_FILE_KCONFIG.match(gitfile):
> + kconfig_files.append(gitfile)
> + else:
> + if ignore and re.match(ignore, gitfile):
> + continue
> + # add source files that do not match the ignore pattern
> + source_files.append(gitfile)
> +
> + # parse source files
> + arglist = partition(source_files, cpu_count())
> + for res in pool.map(parse_source_files, arglist):
> + referenced_symbols.update(res)
> +
> + # parse kconfig files
> + arglist = []
> + for part in partition(kconfig_files, cpu_count()):
> + arglist.append((part, ignore))
> + for res in pool.map(parse_kconfig_files, arglist):
> + defined_symbols.extend(res[0])
> + referenced_symbols.update(res[1])
> + defined_symbols = set(defined_symbols)
> +
> + # inverse mapping of referenced_symbols to dict(symbol: [files])
> + inv_map = dict()
> + for _file, symbols in referenced_symbols.items():
> + for symbol in symbols:
> + inv_map[symbol] = inv_map.get(symbol, set())
> + inv_map[symbol].add(_file)
> + referenced_symbols = inv_map
> +
> + undefined = {} # {symbol: [files]}
> + for symbol in sorted(referenced_symbols):
> + # filter some false positives
> + if symbol == "FOO" or symbol == "BAR" or \
> + symbol == "FOO_BAR" or symbol == "XXX":
> + continue
> + if symbol not in defined_symbols:
> + if symbol.endswith("_MODULE"):
> + # avoid false positives for kernel modules
> + if symbol[:-len("_MODULE")] in defined_symbols:
> + continue
> + undefined[symbol] = referenced_symbols.get(symbol)
> + return undefined, defined_symbols
> +
> +
> +def parse_source_files(source_files):
> + """Parse each source file in @source_files and return dictionary with source
> + files as keys and lists of references Kconfig symbols as values."""
> + referenced_symbols = dict()
> + for sfile in source_files:
> + referenced_symbols[sfile] = parse_source_file(sfile)
> + return referenced_symbols
> +
> +
> +def parse_source_file(sfile):
> + """Parse @sfile and return a list of referenced Kconfig symbols."""
> + lines = []
> + references = []
> +
> + if not os.path.exists(sfile):
> + return references
> +
> + with open(sfile, "r", encoding='utf-8', errors='replace') as stream:
> + lines = stream.readlines()
> +
> + for line in lines:
> + if "CONFIG_" not in line:
> + continue
> + symbols = REGEX_SOURCE_SYMBOL.findall(line)
> + for symbol in symbols:
> + if not REGEX_FILTER_SYMBOLS.search(symbol):
> + continue
> + references.append(symbol)
> +
> + return references
> +
> +
> +def get_symbols_in_line(line):
> + """Return mentioned Kconfig symbols in @line."""
> + return REGEX_SYMBOL.findall(line)
> +
> +
> +def parse_kconfig_files(args):
> + """Parse kconfig files and return tuple of defined and references Kconfig
> + symbols. Note, @args is a tuple of a list of files and the @ignore
> + pattern."""
> + kconfig_files = args[0]
> + ignore = args[1]
> + defined_symbols = []
> + referenced_symbols = dict()
> +
> + for kfile in kconfig_files:
> + defined, references = parse_kconfig_file(kfile)
> + defined_symbols.extend(defined)
> + if ignore and re.match(ignore, kfile):
> + # do not collect references for files that match the ignore pattern
> + continue
> + referenced_symbols[kfile] = references
> + return (defined_symbols, referenced_symbols)
> +
> +
> +def parse_kconfig_file(kfile):
> + """Parse @kfile and update symbol definitions and references."""
> + lines = []
> + defined = []
> + references = []
> +
> + if not os.path.exists(kfile):
> + return defined, references
> +
> + with open(kfile, "r", encoding='utf-8', errors='replace') as stream:
> + lines = stream.readlines()
> +
> + for i in range(len(lines)):
> + line = lines[i]
> + line = line.strip('\n')
> + line = line.split("#")[0] # ignore comments
> +
> + if REGEX_KCONFIG_DEF.match(line):
> + symbol_def = REGEX_KCONFIG_DEF.findall(line)
> + defined.append(symbol_def[0])
> + elif REGEX_KCONFIG_STMT.match(line):
> + line = REGEX_QUOTES.sub("", line)
> + symbols = get_symbols_in_line(line)
> + # multi-line statements
> + while line.endswith("\\"):
> + i += 1
> + line = lines[i]
> + line = line.strip('\n')
> + symbols.extend(get_symbols_in_line(line))
> + for symbol in set(symbols):
> + if REGEX_NUMERIC.match(symbol):
> + # ignore numeric values
> + continue
> + references.append(symbol)
> +
> + return defined, references
> +
> +
> +def main():
> + try:
> + print_undefined_symbols()
> + except BrokenPipeError:
> + # Python flushes standard streams on exit; redirect remaining output
> + # to devnull to avoid another BrokenPipeError at shutdown
> + devnull = os.open(os.devnull, os.O_WRONLY)
> + os.dup2(devnull, sys.stdout.fileno())
> + sys.exit(1) # Python exits with error code 1 on EPIPE
> +
> +
> +if __name__ == "__main__":
> + main()
> --
> 2.51.0
>
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