#! /usr/bin/env perl

  # SPDX-License-Identifier: GPL-2.0

  #

  # checkversion find uses of LINUX_VERSION_CODE or KERNEL_VERSION
  # without including <linux/version.h>, or cases of

  # including <linux/version.h> that don't need it.

  # Copyright (C) 2003, Randy Dunlap <rdunlap@xenotime.net>

  use strict;

  $| = 1;

  my $debugging;

  foreach my $file (@ARGV) {

      next if $file =~ "include/linux/version\.h";

      # Open this file.

      open( my $f, '<', $file )
        or die "Can't open $file: $!
  ";

  
      # Initialize variables.

      my ($fInComment, $fInString, $fUseVersion);

      my $iLinuxVersion = 0;

      while (<$f>) {

  	# Strip comments.
  	$fInComment && (s+^.*?\*/+ +o ? ($fInComment = 0) : next);
  	m+/\*+o && (s+/\*.*?\*/+ +go, (s+/\*.*$+ +o && ($fInComment = 1)));
  
  	# Pick up definitions.
  	if ( m/^\s*#/o ) {
  	    $iLinuxVersion      = $. if m/^\s*#\s*include\s*"linux\/version\.h"/o;
  	}
  
  	# Strip strings.
  	$fInString && (s+^.*?"+ +o ? ($fInString = 0) : next);
  	m+"+o && (s+".*?"+ +go, (s+".*$+ +o && ($fInString = 1)));
  
  	# Pick up definitions.
  	if ( m/^\s*#/o ) {
  	    $iLinuxVersion      = $. if m/^\s*#\s*include\s*<linux\/version\.h>/o;
  	}
  
  	# Look for uses: LINUX_VERSION_CODE, KERNEL_VERSION, UTS_RELEASE

  	if (($_ =~ /LINUX_VERSION_CODE/) || ($_ =~ /\WKERNEL_VERSION/)) {

  	    $fUseVersion = 1;

              last if $iLinuxVersion;
          }

      }
  
      # Report used version IDs without include?
      if ($fUseVersion && ! $iLinuxVersion) {
  	print "$file: $.: need linux/version.h
  ";
      }
  
      # Report superfluous includes.
      if ($iLinuxVersion && ! $fUseVersion) {
  	print "$file: $iLinuxVersion linux/version.h not needed.
  ";
      }
  
      # debug: report OK results:
      if ($debugging) {
          if ($iLinuxVersion && $fUseVersion) {
  	    print "$file: version use is OK ($iLinuxVersion)
  ";
          }
          if (! $iLinuxVersion && ! $fUseVersion) {
  	    print "$file: version use is OK (none)
  ";
          }
      }

      close($f);

  }