Linux Cross Reference
Linux/scripts/checkconfig.pl

   #! /usr/bin/perl
   #
   # checkconfig: find uses of CONFIG_* names without matching definitions.
   # Copyright abandoned, 1998, Michael Elizabeth Chastain <mailto:mec@shout.net>.
   
   use integer;
   
   $| = 1;
   
  foreach $file (@ARGV)
  {
      # Open this file.
      open(FILE, $file) || die "Can't open $file: $!\n";
  
      # Initialize variables.
      my $fInComment   = 0;
      my $fUseConfig   = 0;
      my $iLinuxConfig = 0;
      my %configList   = ();
  
      LINE: while ( <FILE> )
      {
          # Strip comments.
          $fInComment && (s+^.*?\*/+ +o ? ($fInComment = 0) : next);
          m+/\*+o && (s+/\*.*?\*/+ +go, (s+/\*.*$+ +o && ($fInComment = 1)));
  
          # Pick up definitions.
          if ( m/^\s*#/o )
          {
              $iLinuxConfig      = $. if m/^\s*#\s*include\s*<linux\/config\.h>/o;
              $configList{uc $1} = 1  if m/^\s*#\s*include\s*<config\/(\S*)\.h>/o;
              $configList{$1}    = 1  if m/^\s*#\s*define\s+CONFIG_(\w*)/o;
              $configList{$1}    = 1  if m/^\s*#\s*undef\s+CONFIG_(\w*)/o;
          }
  
          # Look for usages.
          next unless m/CONFIG_/o;
          WORD: while ( m/\bCONFIG_(\w+)/og )
          {
              $fUseConfig = 1;
              last LINE if $iLinuxConfig;
              next WORD if exists $configList{$1};
              print "$file: $.: need CONFIG_$1.\n";
              $configList{$1} = 0;
          }
      }
  
      # Report superfluous includes.
      if ( $iLinuxConfig && ! $fUseConfig )
          { print "$file: $iLinuxConfig: <linux/config.h> not needed.\n"; }
  
      close(FILE);
  }