kernel/scripts/checkkconfigsymbols.py

   1 #!/usr/bin/env python
   2
   3 """Find Kconfig symbols that are referenced but not defined."""
   4
   5 # (c) 2014-2015 Valentin Rothberg <Valentin.Rothberg@lip6.fr>
   6 # (c) 2014 Stefan Hengelein <stefan.hengelein@fau.de>
   7 #
   8 # Licensed under the terms of the GNU GPL License version 2
   9
  10
  11 import os
  12 import re
  13 import sys
  14 from subprocess import Popen, PIPE, STDOUT
  15 from optparse import OptionParser
  16
  17
  18 # regex expressions
  19 OPERATORS = r"&|\(|\)|\||\!"
  20 FEATURE = r"(?:\w*[A-Z0-9]\w*){2,}"
  21 DEF = r"^\s*(?:menu){,1}config\s+(" + FEATURE + r")\s*"
  22 EXPR = r"(?:" + OPERATORS + r"|\s|" + FEATURE + r")+"
  23 STMT = r"^\s*(?:if|select|depends\s+on)\s+" + EXPR
  24 SOURCE_FEATURE = r"(?:\W|\b)+[D]{,1}CONFIG_(" + FEATURE + r")"
  25
  26 # regex objects
  27 REGEX_FILE_KCONFIG = re.compile(r".*Kconfig[\.\w+\-]*$")
  28 REGEX_FEATURE = re.compile(r"(" + FEATURE + r")")
  29 REGEX_SOURCE_FEATURE = re.compile(SOURCE_FEATURE)
  30 REGEX_KCONFIG_DEF = re.compile(DEF)
  31 REGEX_KCONFIG_EXPR = re.compile(EXPR)
  32 REGEX_KCONFIG_STMT = re.compile(STMT)
  33 REGEX_KCONFIG_HELP = re.compile(r"^\s+(help|---help---)\s*$")
  34 REGEX_FILTER_FEATURES = re.compile(r"[A-Za-z0-9]$")
  35
  36
  37 def parse_options():
  38     """The user interface of this module."""
  39     usage = "%prog [options]\n\n"                                              \
  40             "Run this tool to detect Kconfig symbols that are referenced but " \
  41             "not defined in\nKconfig.  The output of this tool has the "       \
  42             "format \'Undefined symbol\\tFile list\'\n\n"                      \
  43             "If no option is specified, %prog will default to check your\n"    \
  44             "current tree.  Please note that specifying commits will "         \
  45             "\'git reset --hard\'\nyour current tree!  You may save "          \
  46             "uncommitted changes to avoid losing data."
  47
  48     parser = OptionParser(usage=usage)
  49
  50     parser.add_option('-c', '--commit', dest='commit', action='store',
  51                       default="",
  52                       help="Check if the specified commit (hash) introduces "
  53                            "undefined Kconfig symbols.")
  54
  55     parser.add_option('-d', '--diff', dest='diff', action='store',
  56                       default="",
  57                       help="Diff undefined symbols between two commits.  The "
  58                            "input format bases on Git log's "
  59                            "\'commmit1..commit2\'.")
  60
  61     parser.add_option('', '--force', dest='force', action='store_true',
  62                       default=False,
  63                       help="Reset current Git tree even when it's dirty.")
  64
  65     (opts, _) = parser.parse_args()
  66
  67     if opts.commit and opts.diff:
  68         sys.exit("Please specify only one option at once.")
  69
  70     if opts.diff and not re.match(r"^[\w\-\.]+\.\.[\w\-\.]+$", opts.diff):
  71         sys.exit("Please specify valid input in the following format: "
  72                  "\'commmit1..commit2\'")
  73
  74     if opts.commit or opts.diff:
  75         if not opts.force and tree_is_dirty():
  76             sys.exit("The current Git tree is dirty (see 'git status').  "
  77                      "Running this script may\ndelete important data since it "
  78                      "calls 'git reset --hard' for some performance\nreasons. "
  79                      " Please run this script in a clean Git tree or pass "
  80                      "'--force' if you\nwant to ignore this warning and "
  81                      "continue.")
  82
  83     return opts
  84
  85
  86 def main():
  87     """Main function of this module."""
  88     opts = parse_options()
  89
  90     if opts.commit or opts.diff:
  91         head = get_head()
  92
  93         # get commit range
  94         commit_a = None
  95         commit_b = None
  96         if opts.commit:
  97             commit_a = opts.commit + "~"
  98             commit_b = opts.commit
  99         elif opts.diff:
 100             split = opts.diff.split("..")
 101             commit_a = split[0]
 102             commit_b = split[1]
 103             undefined_a = {}
 104             undefined_b = {}
 105
 106         # get undefined items before the commit
 107         execute("git reset --hard %s" % commit_a)
 108         undefined_a = check_symbols()
 109
 110         # get undefined items for the commit
 111         execute("git reset --hard %s" % commit_b)
 112         undefined_b = check_symbols()
 113
 114         # report cases that are present for the commit but not before
 115         for feature in sorted(undefined_b):
 116             # feature has not been undefined before
 117             if not feature in undefined_a:
 118                 files = sorted(undefined_b.get(feature))
 119                 print "%s\t%s" % (feature, ", ".join(files))
 120             # check if there are new files that reference the undefined feature
 121             else:
 122                 files = sorted(undefined_b.get(feature) -
 123                                undefined_a.get(feature))
 124                 if files:
 125                     print "%s\t%s" % (feature, ", ".join(files))
 126
 127         # reset to head
 128         execute("git reset --hard %s" % head)
 129
 130     # default to check the entire tree
 131     else:
 132         undefined = check_symbols()
 133         for feature in sorted(undefined):
 134             files = sorted(undefined.get(feature))
 135             print "%s\t%s" % (feature, ", ".join(files))
 136
 137
 138 def execute(cmd):
 139     """Execute %cmd and return stdout.  Exit in case of error."""
 140     pop = Popen(cmd, stdout=PIPE, stderr=STDOUT, shell=True)
 141     (stdout, _) = pop.communicate()  # wait until finished
 142     if pop.returncode != 0:
 143         sys.exit(stdout)
 144     return stdout
 145
 146
 147 def tree_is_dirty():
 148     """Return true if the current working tree is dirty (i.e., if any file has
 149     been added, deleted, modified, renamed or copied but not committed)."""
 150     stdout = execute("git status --porcelain")
 151     for line in stdout:
 152         if re.findall(r"[URMADC]{1}", line[:2]):
 153             return True
 154     return False
 155
 156
 157 def get_head():
 158     """Return commit hash of current HEAD."""
 159     stdout = execute("git rev-parse HEAD")
 160     return stdout.strip('\n')
 161
 162
 163 def check_symbols():
 164     """Find undefined Kconfig symbols and return a dict with the symbol as key
 165     and a list of referencing files as value."""
 166     source_files = []
 167     kconfig_files = []
 168     defined_features = set()
 169     referenced_features = dict()  # {feature: [files]}
 170
 171     # use 'git ls-files' to get the worklist
 172     stdout = execute("git ls-files")
 173     if len(stdout) > 0 and stdout[-1] == "\n":
 174         stdout = stdout[:-1]
 175
 176     for gitfile in stdout.rsplit("\n"):
 177         if ".git" in gitfile or "ChangeLog" in gitfile or      \
 178                 ".log" in gitfile or os.path.isdir(gitfile) or \
 179                 gitfile.startswith("tools/"):
 180             continue
 181         if REGEX_FILE_KCONFIG.match(gitfile):
 182             kconfig_files.append(gitfile)
 183         else:
 184             # all non-Kconfig files are checked for consistency
 185             source_files.append(gitfile)
 186
 187     for sfile in source_files:
 188         parse_source_file(sfile, referenced_features)
 189
 190     for kfile in kconfig_files:
 191         parse_kconfig_file(kfile, defined_features, referenced_features)
 192
 193     undefined = {}  # {feature: [files]}
 194     for feature in sorted(referenced_features):
 195         # filter some false positives
 196         if feature == "FOO" or feature == "BAR" or \
 197                 feature == "FOO_BAR" or feature == "XXX":
 198             continue
 199         if feature not in defined_features:
 200             if feature.endswith("_MODULE"):
 201                 # avoid false positives for kernel modules
 202                 if feature[:-len("_MODULE")] in defined_features:
 203                     continue
 204             undefined[feature] = referenced_features.get(feature)
 205     return undefined
 206
 207
 208 def parse_source_file(sfile, referenced_features):
 209     """Parse @sfile for referenced Kconfig features."""
 210     lines = []
 211     with open(sfile, "r") as stream:
 212         lines = stream.readlines()
 213
 214     for line in lines:
 215         if not "CONFIG_" in line:
 216             continue
 217         features = REGEX_SOURCE_FEATURE.findall(line)
 218         for feature in features:
 219             if not REGEX_FILTER_FEATURES.search(feature):
 220                 continue
 221             sfiles = referenced_features.get(feature, set())
 222             sfiles.add(sfile)
 223             referenced_features[feature] = sfiles
 224
 225
 226 def get_features_in_line(line):
 227     """Return mentioned Kconfig features in @line."""
 228     return REGEX_FEATURE.findall(line)
 229
 230
 231 def parse_kconfig_file(kfile, defined_features, referenced_features):
 232     """Parse @kfile and update feature definitions and references."""
 233     lines = []
 234     skip = False
 235
 236     with open(kfile, "r") as stream:
 237         lines = stream.readlines()
 238
 239     for i in range(len(lines)):
 240         line = lines[i]
 241         line = line.strip('\n')
 242         line = line.split("#")[0]  # ignore comments
 243
 244         if REGEX_KCONFIG_DEF.match(line):
 245             feature_def = REGEX_KCONFIG_DEF.findall(line)
 246             defined_features.add(feature_def[0])
 247             skip = False
 248         elif REGEX_KCONFIG_HELP.match(line):
 249             skip = True
 250         elif skip:
 251             # ignore content of help messages
 252             pass
 253         elif REGEX_KCONFIG_STMT.match(line):
 254             features = get_features_in_line(line)
 255             # multi-line statements
 256             while line.endswith("\\"):
 257                 i += 1
 258                 line = lines[i]
 259                 line = line.strip('\n')
 260                 features.extend(get_features_in_line(line))
 261             for feature in set(features):
 262                 paths = referenced_features.get(feature, set())
 263                 paths.add(kfile)
 264                 referenced_features[feature] = paths
 265
 266
 267 if __name__ == "__main__":
 268     main()