#!/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@gmail.com>

  # (c) 2014 Stefan Hengelein <stefan.hengelein@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
  delete important data since it "
                       "calls 'git reset --hard' for some performance
  reasons. "
                       " Please run this script in a clean Git tree or pass "
                       "'--force' if you
  want 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 main():
      """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("
  ") 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('
  ')

  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] == "
  ":
          stdout = stdout[:-1]
  
      files = []
      for gitfile in stdout.rsplit("
  "):
          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('
  ')

          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('
  ')

                  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

  
  
  if __name__ == "__main__":
      main()