#!/usr/bin/env python2

  """Find Kconfig symbols that are referenced but not defined."""

  # (c) 2014-2015 Valentin Rothberg <valentinrothberg@gmail.com>

  # (c) 2014 Stefan Hengelein <stefan.hengelein@fau.de>

  #

  # Licensed under the terms of the GNU GPL License version 2

  import difflib

  import os
  import re

  import signal

  import sys

  from multiprocessing import Pool, cpu_count

  from optparse import OptionParser

  from subprocess import Popen, PIPE, STDOUT

  
  # regex expressions

  OPERATORS = r"&|\(|\)|\||\!"

  FEATURE = r"(?:\w*[A-Z0-9]\w*){2,}"
  DEF = r"^\s*(?:menu){,1}config\s+(" + FEATURE + r")\s*"

  EXPR = r"(?:" + OPERATORS + r"|\s|" + FEATURE + r")+"

  DEFAULT = r"default\s+.*?(?:if\s.+){,1}"
  STMT = r"^\s*(?:if|select|depends\s+on|(?:" + DEFAULT + r"))\s+" + EXPR

  SOURCE_FEATURE = r"(?:\W|\b)+[D]{,1}CONFIG_(" + FEATURE + r")"

  # regex objects

  REGEX_FILE_KCONFIG = re.compile(r".*Kconfig[\.\w+\-]*$")

  REGEX_FEATURE = re.compile(r'(?!\B)' + FEATURE + r'(?!\B)')

  REGEX_SOURCE_FEATURE = re.compile(SOURCE_FEATURE)
  REGEX_KCONFIG_DEF = re.compile(DEF)

  REGEX_KCONFIG_EXPR = re.compile(EXPR)
  REGEX_KCONFIG_STMT = re.compile(STMT)
  REGEX_KCONFIG_HELP = re.compile(r"^\s+(help|---help---)\s*$")
  REGEX_FILTER_FEATURES = re.compile(r"[A-Za-z0-9]$")

  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 = "%prog [options]
  
  "                                              \
              "Run this tool to detect Kconfig symbols that are referenced but " \
              "not defined in
  Kconfig.  The output of this tool has the "       \
              "format \'Undefined symbol\\tFile list\'
  
  "                      \
              "If no option is specified, %prog will default 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 = OptionParser(usage=usage)
  
      parser.add_option('-c', '--commit', dest='commit', action='store',
                        default="",
                        help="Check if the specified commit (hash) introduces "
                             "undefined Kconfig symbols.")
  
      parser.add_option('-d', '--diff', dest='diff', action='store',
                        default="",
                        help="Diff undefined symbols between two commits.  The "
                             "input format bases on Git log's "
                             "\'commmit1..commit2\'.")

      parser.add_option('-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_option('-i', '--ignore', dest='ignore', action='store',
                        default="",
                        help="Ignore files matching this pattern.  Note that "
                             "the pattern needs to be a Python regex.  To "
                             "ignore defconfigs, specify -i '.*defconfig'.")

      parser.add_option('-s', '--sim', dest='sim', action='store', default="",
                        help="Print a list of maximum 10 string-similar symbols.")

      parser.add_option('', '--force', dest='force', action='store_true',
                        default=False,
                        help="Reset current Git tree even when it's dirty.")
  
      (opts, _) = parser.parse_args()
  
      if opts.commit and opts.diff:
          sys.exit("Please specify only one option at once.")
  
      if opts.diff and not re.match(r"^[\w\-\.]+\.\.[\w\-\.]+$", opts.diff):
          sys.exit("Please specify valid input in the following format: "

                   "\'commit1..commit2\'")

  
      if opts.commit or opts.diff:
          if not opts.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 opts.commit:
          opts.find = False

      if opts.ignore:
          try:
              re.match(opts.ignore, "this/is/just/a/test.c")
          except:
              sys.exit("Please specify a valid Python regex.")

      return opts

  def main():
      """Main function of this module."""

      opts = parse_options()

      if opts.sim and not opts.commit and not opts.diff:
          sims = find_sims(opts.sim, opts.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 opts.commit or opts.diff:
          head = get_head()
  
          # get commit range
          commit_a = None
          commit_b = None
          if opts.commit:
              commit_a = opts.commit + "~"
              commit_b = opts.commit
          elif opts.diff:
              split = opts.diff.split("..")
              commit_a = split[0]
              commit_b = split[1]
              undefined_a = {}
              undefined_b = {}
  
          # get undefined items before the commit
          execute("git reset --hard %s" % commit_a)

          undefined_a, _ = check_symbols(opts.ignore)

  
          # get undefined items for the commit
          execute("git reset --hard %s" % commit_b)

          undefined_b, defined = check_symbols(opts.ignore)

  
          # report cases that are present for the commit but not before

          for feature in sorted(undefined_b):

              # feature has not been undefined before
              if not feature in undefined_a:

                  files = sorted(undefined_b.get(feature))

                  undefined[feature] = files

              # check if there are new files that reference the undefined feature
              else:

                  files = sorted(undefined_b.get(feature) -
                                 undefined_a.get(feature))

                  if files:

                      undefined[feature] = files

  
          # reset to head
          execute("git reset --hard %s" % head)
  
      # default to check the entire tree
      else:

          undefined, defined = check_symbols(opts.ignore)
  
      # now print the output
      for feature in sorted(undefined):
          print red(feature)
  
          files = sorted(undefined.get(feature))
          print "%s: %s" % (yel("Referencing files"), ", ".join(files))
  
          sims = find_sims(feature, opts.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 opts.find:
              print "%s:" % yel("Commits changing symbol")
              commits = find_commits(feature, opts.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 yel(string):
      """
      Color %string yellow.
      """
      return "\033[33m%s\033[0m" % string
  
  
  def red(string):
      """
      Color %string red.
      """
      return "\033[31m%s\033[0m" % string

  
  
  def execute(cmd):
      """Execute %cmd and return stdout.  Exit in case of error."""
      pop = Popen(cmd, stdout=PIPE, stderr=STDOUT, shell=True)
      (stdout, _) = pop.communicate()  # wait until finished
      if pop.returncode != 0:
          sys.exit(stdout)
      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 %s %s"
                        % (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 xrange(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 sorted(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 sorted(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_features = []
      referenced_features = dict()  # {file: [features]}

      for gitfile in get_files():

          if REGEX_FILE_KCONFIG.match(gitfile):
              kconfig_files.append(gitfile)
          else:

              if ignore and not 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_features.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_features.extend(res[0])
          referenced_features.update(res[1])
      defined_features = set(defined_features)
  
      # inverse mapping of referenced_features to dict(feature: [files])
      inv_map = dict()
      for _file, features in referenced_features.iteritems():
          for feature in features:
              inv_map[feature] = inv_map.get(feature, set())
              inv_map[feature].add(_file)
      referenced_features = inv_map

      undefined = {}  # {feature: [files]}

      for feature in sorted(referenced_features):

          # filter some false positives
          if feature == "FOO" or feature == "BAR" or \
                  feature == "FOO_BAR" or feature == "XXX":
              continue

          if feature not in defined_features:
              if feature.endswith("_MODULE"):

                  # avoid false positives for kernel modules

                  if feature[:-len("_MODULE")] in defined_features:
                      continue

              undefined[feature] = referenced_features.get(feature)

      return undefined, defined_features

  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_features = dict()
      for sfile in source_files:
          referenced_features[sfile] = parse_source_file(sfile)
      return referenced_features
  
  
  def parse_source_file(sfile):
      """Parse @sfile and return a list of referenced Kconfig features."""

      lines = []

      references = []
  
      if not os.path.exists(sfile):
          return references

      with open(sfile, "r") as stream:
          lines = stream.readlines()
  
      for line in lines:
          if not "CONFIG_" in line:
              continue
          features = REGEX_SOURCE_FEATURE.findall(line)
          for feature in features:
              if not REGEX_FILTER_FEATURES.search(feature):
                  continue

              references.append(feature)
  
      return references

  
  
  def get_features_in_line(line):
      """Return mentioned Kconfig features in @line."""
      return REGEX_FEATURE.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_features = []
      referenced_features = dict()
  
      for kfile in kconfig_files:
          defined, references = parse_kconfig_file(kfile)
          defined_features.extend(defined)
          if ignore and re.match(ignore, kfile):
              # do not collect references for files that match the ignore pattern
              continue
          referenced_features[kfile] = references
      return (defined_features, referenced_features)
  
  
  def parse_kconfig_file(kfile):

      """Parse @kfile and update feature definitions and references."""
      lines = []

      defined = []
      references = []

      skip = False

      if not os.path.exists(kfile):
          return defined, references

      with open(kfile, "r") 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):
              feature_def = REGEX_KCONFIG_DEF.findall(line)

              defined.append(feature_def[0])

              skip = False
          elif REGEX_KCONFIG_HELP.match(line):
              skip = True
          elif skip:

              # ignore content of help messages

              pass
          elif REGEX_KCONFIG_STMT.match(line):

              line = REGEX_QUOTES.sub("", line)

              features = get_features_in_line(line)

              # multi-line statements

              while line.endswith("\\"):
                  i += 1
                  line = lines[i]
                  line = line.strip('
  ')
                  features.extend(get_features_in_line(line))
              for feature in set(features):

                  if REGEX_NUMERIC.match(feature):
                      # ignore numeric values
                      continue

                  references.append(feature)
  
      return defined, references

  
  
  if __name__ == "__main__":
      main()