#!/usr/bin/perl -w
  # (c) 2001, Dave Jones. <davej@codemonkey.org.uk> (the file handling bit)

  # (c) 2005, Joel Schopp <jschopp@austin.ibm.com> (the ugly bit)

  # (c) 2007, Andy Whitcroft <apw@uk.ibm.com> (new conditions, test suite, etc)
  # Licensed under the terms of the GNU GPL License version 2
  
  use strict;
  
  my $P = $0;

  $P =~ s@.*/@@g;

  my $V = '0.09';

  
  use Getopt::Long qw(:config no_auto_abbrev);
  
  my $quiet = 0;
  my $tree = 1;
  my $chk_signoff = 1;
  my $chk_patch = 1;

  my $tst_type = 0;

  GetOptions(
  	'q|quiet'	=> \$quiet,
  	'tree!'		=> \$tree,
  	'signoff!'	=> \$chk_signoff,
  	'patch!'	=> \$chk_patch,

  	'test-type!'	=> \$tst_type,

  ) or exit;
  
  my $exit = 0;
  
  if ($#ARGV < 0) {

  	print "usage: $P [options] patchfile
  ";

  	print "version: $V
  ";
  	print "options: -q           => quiet
  ";
  	print "         --no-tree    => run without a kernel tree
  ";
  	exit(1);
  }
  
  if ($tree && !top_of_kernel_tree()) {
  	print "Must be run from the top-level dir. of a kernel tree
  ";
  	exit(2);
  }

  my @dep_includes = ();
  my @dep_functions = ();

  my $removal = 'Documentation/feature-removal-schedule.txt';
  if ($tree && -f $removal) {
  	open(REMOVE, "<$removal") || die "$P: $removal: open failed - $!
  ";
  	while (<REMOVE>) {

  		if (/^Check:\s+(.*\S)/) {
  			for my $entry (split(/[, ]+/, $1)) {
  				if ($entry =~ m@include/(.*)@) {

  					push(@dep_includes, $1);

  				} elsif ($entry !~ m@/@) {
  					push(@dep_functions, $entry);
  				}

  			}

  		}
  	}
  }

  my @rawlines = ();

  while (<>) {
  	chomp;

  	push(@rawlines, $_);

  	if (eof(ARGV)) {

  		if (!process($ARGV, @rawlines)) {

  			$exit = 1;
  		}

  		@rawlines = ();

  	}
  }
  
  exit($exit);
  
  sub top_of_kernel_tree {
  	if ((-f "COPYING") && (-f "CREDITS") && (-f "Kbuild") &&
  	    (-f "MAINTAINERS") && (-f "Makefile") && (-f "README") &&
  	    (-d "Documentation") && (-d "arch") && (-d "include") &&
  	    (-d "drivers") && (-d "fs") && (-d "init") && (-d "ipc") &&
  	    (-d "kernel") && (-d "lib") && (-d "scripts")) {
  		return 1;
  	}
  	return 0;
  }
  
  sub expand_tabs {
  	my ($str) = @_;
  
  	my $res = '';
  	my $n = 0;
  	for my $c (split(//, $str)) {
  		if ($c eq "\t") {
  			$res .= ' ';
  			$n++;
  			for (; ($n % 8) != 0; $n++) {
  				$res .= ' ';
  			}
  			next;
  		}
  		$res .= $c;
  		$n++;
  	}
  
  	return $res;
  }

  sub line_stats {
  	my ($line) = @_;
  
  	# Drop the diff line leader and expand tabs
  	$line =~ s/^.//;
  	$line = expand_tabs($line);
  
  	# Pick the indent from the front of the line.
  	my ($white) = ($line =~ /^(\s*)/);
  
  	return (length($line), length($white));
  }

  sub sanitise_line {
  	my ($line) = @_;
  
  	my $res = '';
  	my $l = '';
  
  	my $quote = '';
  
  	foreach my $c (split(//, $line)) {
  		if ($l ne "\\" && ($c eq "'" || $c eq '"')) {
  			if ($quote eq '') {
  				$quote = $c;
  				$res .= $c;
  				$l = $c;
  				next;
  			} elsif ($quote eq $c) {
  				$quote = '';
  			}
  		}
  		if ($quote && $c ne "\t") {
  			$res .= "X";
  		} else {
  			$res .= $c;
  		}
  
  		$l = $c;
  	}
  
  	return $res;
  }

  sub ctx_block_get {

  	my ($linenr, $remain, $outer, $open, $close, $off) = @_;

  	my $line;
  	my $start = $linenr - 1;

  	my $blk = '';
  	my @o;
  	my @c;
  	my @res = ();

  	my $level = 0;

  	for ($line = $start; $remain > 0; $line++) {
  		next if ($rawlines[$line] =~ /^-/);
  		$remain--;
  
  		$blk .= $rawlines[$line];

  		foreach my $c (split(//, $rawlines[$line])) {
  			##print "C<$c>L<$level><$open$close>O<$off>
  ";
  			if ($off > 0) {
  				$off--;
  				next;
  			}

  			if ($c eq $close && $level > 0) {
  				$level--;
  				last if ($level == 0);
  			} elsif ($c eq $open) {
  				$level++;
  			}
  		}

  		if (!$outer || $level <= 1) {

  			push(@res, $rawlines[$line]);

  		}

  		last if ($level == 0);

  	}

  	return ($level, @res);

  }
  sub ctx_block_outer {
  	my ($linenr, $remain) = @_;

  	my ($level, @r) = ctx_block_get($linenr, $remain, 1, '{', '}', 0);
  	return @r;

  }
  sub ctx_block {
  	my ($linenr, $remain) = @_;

  	my ($level, @r) = ctx_block_get($linenr, $remain, 0, '{', '}', 0);
  	return @r;

  }
  sub ctx_statement {

  	my ($linenr, $remain, $off) = @_;
  
  	my ($level, @r) = ctx_block_get($linenr, $remain, 0, '(', ')', $off);
  	return @r;
  }
  sub ctx_block_level {

  	my ($linenr, $remain) = @_;

  	return ctx_block_get($linenr, $remain, 0, '{', '}', 0);

  }
  
  sub ctx_locate_comment {
  	my ($first_line, $end_line) = @_;
  
  	# Catch a comment on the end of the line itself.

  	my ($current_comment) = ($rawlines[$end_line - 1] =~ m@.*(/\*.*\*/)\s*$@);

  	return $current_comment if (defined $current_comment);
  
  	# Look through the context and try and figure out if there is a
  	# comment.
  	my $in_comment = 0;
  	$current_comment = '';
  	for (my $linenr = $first_line; $linenr < $end_line; $linenr++) {

  		my $line = $rawlines[$linenr - 1];
  		#warn "           $line
  ";

  		if ($linenr == $first_line and $line =~ m@^.\s*\*@) {
  			$in_comment = 1;
  		}
  		if ($line =~ m@/\*@) {
  			$in_comment = 1;
  		}
  		if (!$in_comment && $current_comment ne '') {
  			$current_comment = '';
  		}
  		$current_comment .= $line . "
  " if ($in_comment);
  		if ($line =~ m@\*/@) {
  			$in_comment = 0;
  		}
  	}
  
  	chomp($current_comment);
  	return($current_comment);
  }
  sub ctx_has_comment {
  	my ($first_line, $end_line) = @_;
  	my $cmt = ctx_locate_comment($first_line, $end_line);

  	##print "LINE: $rawlines[$end_line - 1 ]
  ";

  	##print "CMMT: $cmt
  ";
  
  	return ($cmt ne '');
  }

  sub cat_vet {
  	my ($vet) = @_;
  
  	$vet =~ s/\t/^I/;
  	$vet =~ s/$/\$/;
  
  	return $vet;
  }

  my @report = ();
  sub report {
  	push(@report, $_[0]);
  }
  sub report_dump {
  	@report;
  }

  sub ERROR {

  	report("ERROR: $_[0]
  ");

  	our $clean = 0;
  }
  sub WARN {

  	report("WARNING: $_[0]
  ");

  	our $clean = 0;
  }
  sub CHK {

  	report("CHECK: $_[0]
  ");

  	our $clean = 0;
  }

  sub process {
  	my $filename = shift;
  	my @lines = @_;
  
  	my $linenr=0;
  	my $prevline="";
  	my $stashline="";

  	my $length;

  	my $indent;
  	my $previndent=0;
  	my $stashindent=0;

  	our $clean = 1;

  	my $signoff = 0;
  	my $is_patch = 0;
  
  	# Trace the real file/line as we go.
  	my $realfile = '';
  	my $realline = 0;
  	my $realcnt = 0;
  	my $here = '';
  	my $in_comment = 0;
  	my $first_line = 0;

  	my $Ident	= qr{[A-Za-z\d_]+};
  	my $Storage	= qr{extern|static};

  	my $Sparse	= qr{__user|__kernel|__force|__iomem|__must_check|__init_refok};

  	my $NonptrType	= qr{
  				\b
  				(?:const\s+)?
  				(?:unsigned\s+)?
  				(?:
  					void|
  					char|
  					short|
  					int|
  					long|
  					unsigned|
  					float|
  					double|

  					bool|

  					long\s+int|
  					long\s+long|
  					long\s+long\s+int|

  					u8|u16|u32|u64|
  					s8|s16|s32|s64|

  					struct\s+$Ident|
  					union\s+$Ident|

  					enum\s+$Ident|

  					${Ident}_t
  				)
  				(?:\s+$Sparse)*
  				\b
  			  }x;
  	my $Type	= qr{
  				\b$NonptrType\b

  				(?:\s*\*+\s*const|\s*\*+|(?:\s*\[\s*\])+)?
  				(?:\s+$Sparse)*

  			  }x;
  	my $Declare	= qr{(?:$Storage\s+)?$Type};

  	my $Attribute	= qr{const|__read_mostly|__init|__initdata|__meminit};
  
  	my $Member	= qr{->$Ident|\.$Ident|\[[^]]*\]};
  	my $Lval	= qr{$Ident(?:$Member)*};

  	# Pre-scan the patch looking for any __setup documentation.
  	my @setup_docs = ();
  	my $setup_docs = 0;
  	foreach my $line (@lines) {
  		if ($line=~/^\+\+\+\s+(\S+)/) {
  			$setup_docs = 0;
  			if ($1 =~ m@Documentation/kernel-parameters.txt$@) {
  				$setup_docs = 1;
  			}
  			next;
  		}
  
  		if ($setup_docs && $line =~ /^\+/) {
  			push(@setup_docs, $line);
  		}
  	}

  	foreach my $line (@lines) {
  		$linenr++;

  		my $rawline = $line;

  #extract the filename as it passes
  		if ($line=~/^\+\+\+\s+(\S+)/) {
  			$realfile=$1;

  			$realfile =~ s@^[^/]*/@@;

  			$in_comment = 0;
  			next;
  		}
  #extract the line range in the file after the patch is applied
  		if ($line=~/^\@\@ -\d+,\d+ \+(\d+)(,(\d+))? \@\@/) {
  			$is_patch = 1;

  			$first_line = $linenr + 1;

  			$in_comment = 0;
  			$realline=$1-1;
  			if (defined $2) {
  				$realcnt=$3+1;
  			} else {
  				$realcnt=1+1;
  			}
  			next;
  		}

  # track the line number as we move through the hunk, note that
  # new versions of GNU diff omit the leading space on completely
  # blank context lines so we need to count that too.
  		if ($line =~ /^( |\+|$)/) {

  			$realline++;

  			$realcnt-- if ($realcnt != 0);

  
  			# track any sort of multi-line comment.  Obviously if
  			# the added text or context do not include the whole
  			# comment we will not see it. Such is life.
  			#
  			# Guestimate if this is a continuing comment.  If this
  			# is the start of a diff block and this line starts
  			# ' *' then it is very likely a comment.

  			if ($linenr == $first_line and $line =~ m@^.\s*\*@) {

  				$in_comment = 1;
  			}
  			if ($line =~ m@/\*@) {
  				$in_comment = 1;
  			}
  			if ($line =~ m@\*/@) {
  				$in_comment = 0;
  			}

  			# Measure the line length and indent.
  			($length, $indent) = line_stats($line);

  
  			# Track the previous line.
  			($prevline, $stashline) = ($stashline, $line);
  			($previndent, $stashindent) = ($stashindent, $indent);

  		} elsif ($realcnt == 1) {
  			$realcnt--;

  		}
  
  #make up the handle for any error we report on this line

  		$here = "#$linenr: ";
  		$here .= "FILE: $realfile:$realline:" if ($realcnt != 0);

  		my $hereline = "$here
  $line
  ";

  		my $herecurr = "$here
  $line
  ";
  		my $hereprev = "$here
  $prevline
  $line
  ";

  
  #check the patch for a signoff:

  		if ($line =~ /^\s*signed-off-by:/i) {

  			# This is a signoff, if ugly, so do not double report.
  			$signoff++;

  			if (!($line =~ /^\s*Signed-off-by:/)) {

  				WARN("Signed-off-by: is the preferred form
  " .
  					$herecurr);

  			}
  			if ($line =~ /^\s*signed-off-by:\S/i) {

  				WARN("need space after Signed-off-by:
  " .
  					$herecurr);

  			}
  		}

  # Check for wrappage within a valid hunk of the file
  		if ($realcnt != 0 && $line !~ m{^(?:\+|-| |$)}) {

  			ERROR("patch seems to be corrupt (line wrapped?)
  " .
  				$herecurr);
  		}
  
  # UTF-8 regex found at http://www.w3.org/International/questions/qa-forms-utf-8.en.php
  		if (($realfile =~ /^$/ || $line =~ /^\+/) &&
  		     !($line =~ m/^(
  				[\x09\x0A\x0D\x20-\x7E]              # ASCII
  				| [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte
  				|  \xE0[\xA0-\xBF][\x80-\xBF]        # excluding overlongs
  				| [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte
  				|  \xED[\x80-\x9F][\x80-\xBF]        # excluding surrogates
  				|  \xF0[\x90-\xBF][\x80-\xBF]{2}     # planes 1-3
  				| [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15
  				|  \xF4[\x80-\x8F][\x80-\xBF]{2}     # plane 16
  				)*$/x )) {
  			ERROR("Invalid UTF-8
  " . $herecurr);

  		}
  
  #ignore lines being removed
  		if ($line=~/^-/) {next;}

  # check we are in a valid source file if not then ignore this hunk
  		next if ($realfile !~ /\.(h|c|s|S|pl|sh)$/);

  
  #trailing whitespace

  		if ($line =~ /^\+.*\S\s+$/ || $line =~ /^\+\s+$/) {

  			my $herevet = "$here
  " . cat_vet($line) . "
  ";
  			ERROR("trailing whitespace
  " . $herevet);

  		}
  #80 column limit

  		if ($line =~ /^\+/ && !($prevline=~/\/\*\*/) && $length > 80) {

  			WARN("line over 80 characters
  " . $herecurr);

  		}
  
  # check we are in a valid source file *.[hc] if not then ignore this hunk
  		next if ($realfile !~ /\.[hc]$/);
  
  # at the beginning of a line any tabs must come first and anything
  # more than 8 must use tabs.
  		if ($line=~/^\+\s* \t\s*\S/ or $line=~/^\+\s*        \s*/) {

  			my $herevet = "$here
  " . cat_vet($line) . "
  ";
  			ERROR("use tabs not spaces
  " . $herevet);

  		}

  # Remove comments from the line before processing.

  		my $comment_edge = ($line =~ s@/\*.*\*/@@g) +
  				   ($line =~ s@/\*.*@@) +
  				   ($line =~ s@^(.).*\*/@$1@);
  
  # The rest of our checks refer specifically to C style
  # only apply those _outside_ comments.  Only skip
  # lines in the middle of comments.
  		next if (!$comment_edge && $in_comment);

  # Standardise the strings and chars within the input to simplify matching.
  		$line = sanitise_line($line);
  
  #
  # Checks which may be anchored in the context.
  #

  # Check for switch () and associated case and default
  # statements should be at the same indent.

  		if ($line=~/\bswitch\s*\(.*\)/) {
  			my $err = '';
  			my $sep = '';
  			my @ctx = ctx_block_outer($linenr, $realcnt);
  			shift(@ctx);
  			for my $ctx (@ctx) {
  				my ($clen, $cindent) = line_stats($ctx);
  				if ($ctx =~ /^\+\s*(case\s+|default:)/ &&
  							$indent != $cindent) {
  					$err .= "$sep$ctx
  ";
  					$sep = '';
  				} else {
  					$sep = "[...]
  ";
  				}
  			}
  			if ($err ne '') {

  				ERROR("switch and case should be at the same indent
  $hereline
  $err
  ");
  			}
  		}
  
  # if/while/etc brace do not go on next line, unless defining a do while loop,
  # or if that brace on the next line is for something else
  		if ($line =~ /\b(?:(if|while|for|switch)\s*\(|do\b|else\b)/ && $line !~ /^.#/) {

  			my @ctx = ctx_statement($linenr, $realcnt, 0);

  			my $ctx_ln = $linenr + $#ctx + 1;
  			my $ctx_cnt = $realcnt - $#ctx - 1;
  			my $ctx = join("
  ", @ctx);
  
  			while ($ctx_cnt > 0 && $lines[$ctx_ln - 1] =~ /^-/) {
  				$ctx_ln++;
  				$ctx_cnt--;
  			}
  			##warn "line<$line>
  ctx<$ctx>
  next<$lines[$ctx_ln - 1]>";
  
  			if ($ctx !~ /{\s*/ && $ctx_cnt > 0 && $lines[$ctx_ln - 1] =~ /^\+\s*{/) {

  				ERROR("That open brace { should be on the previous line
  " .

  					"$here
  $ctx
  $lines[$ctx_ln - 1]");

  			}
  		}
  
  #ignore lines not being added
  		if ($line=~/^[^\+]/) {next;}

  # TEST: allow direct testing of the type matcher.
  		if ($tst_type && $line =~ /^.$Declare$/) {

  			ERROR("TEST: is type $Declare
  " . $herecurr);

  			next;
  		}

  # check for initialisation to aggregates open brace on the next line
  		if ($prevline =~ /$Declare\s*$Ident\s*=\s*$/ &&
  		    $line =~ /^.\s*{/) {
  			ERROR("That open brace { should be on the previous line
  " . $hereprev);
  		}

  #
  # Checks which are anchored on the added line.
  #
  
  # check for malformed paths in #include statements (uses RAW line)
  		if ($rawline =~ m{^.#\s*include\s+[<"](.*)[">]}) {
  			my $path = $1;
  			if ($path =~ m{//}) {

  				ERROR("malformed #include filename
  " .
  					$herecurr);

  			}
  			# Sanitise this special form of string.
  			$path = 'X' x length($path);
  			$line =~ s{\<.*\>}{<$path>};
  		}

  # no C99 // comments

  		if ($line =~ m{//}) {

  			ERROR("do not use C99 // comments
  " . $herecurr);

  		}

  		# Remove C99 comments.

  		$line =~ s@//.*@@;
  
  #EXPORT_SYMBOL should immediately follow its function closing }.

  		if (($line =~ /EXPORT_SYMBOL.*\((.*)\)/) ||
  		    ($line =~ /EXPORT_UNUSED_SYMBOL.*\((.*)\)/)) {
  			my $name = $1;

  			if (($prevline !~ /^}/) &&
  			   ($prevline !~ /^\+}/) &&

  			   ($prevline !~ /^ }/) &&

  			   ($prevline !~ /\b\Q$name\E(?:\s+$Attribute)?\s*(?:;|=)/)) {

  				WARN("EXPORT_SYMBOL(foo); should immediately follow its function/variable
  " . $herecurr);

  			}
  		}

  # check for external initialisers.
  		if ($line =~ /^.$Type\s*$Ident\s*=\s*(0|NULL);/) {
  			ERROR("do not initialise externals to 0 or NULL
  " .
  				$herecurr);
  		}

  # check for static initialisers.

  		if ($line =~ /\s*static\s.*=\s*(0|NULL);/) {

  			ERROR("do not initialise statics to 0 or NULL
  " .
  				$herecurr);

  		}

  # check for new typedefs, only function parameters and sparse annotations
  # make sense.
  		if ($line =~ /\btypedef\s/ &&

  		    $line !~ /\btypedef\s+$Type\s+\(\s*\*$Ident\s*\)\s*\(/ &&

  		    $line !~ /\b__bitwise(?:__|)\b/) {

  			WARN("do not add new typedefs
  " . $herecurr);

  		}
  
  # * goes on variable not on type

  		if ($line =~ m{\($NonptrType(\*+)(?:\s+const)?\)}) {

  			ERROR("\"(foo$1)\" should be \"(foo $1)\"
  " .
  				$herecurr);

  
  		} elsif ($line =~ m{\($NonptrType\s+(\*+)(?!\s+const)\s+\)}) {

  			ERROR("\"(foo $1 )\" should be \"(foo $1)\"
  " .
  				$herecurr);

  		} elsif ($line =~ m{$NonptrType(\*+)(?:\s+$Attribute)?\s+[A-Za-z\d_]+}) {

  			ERROR("\"foo$1 bar\" should be \"foo $1bar\"
  " .
  				$herecurr);

  		} elsif ($line =~ m{$NonptrType\s+(\*+)(?!\s+$Attribute)\s+[A-Za-z\d_]+}) {

  			ERROR("\"foo $1 bar\" should be \"foo $1bar\"
  " .
  				$herecurr);

  		}
  
  # # no BUG() or BUG_ON()
  # 		if ($line =~ /\b(BUG|BUG_ON)\b/) {
  # 			print "Try to use WARN_ON & Recovery code rather than BUG() or BUG_ON()
  ";
  # 			print "$herecurr";
  # 			$clean = 0;
  # 		}

  # printk should use KERN_* levels.  Note that follow on printk's on the
  # same line do not need a level, so we use the current block context
  # to try and find and validate the current printk.  In summary the current
  # printk includes all preceeding printk's which have no newline on the end.
  # we assume the first bad printk is the one to report.

  		if ($line =~ /\bprintk\((?!KERN_)\s*"/) {

  			my $ok = 0;
  			for (my $ln = $linenr - 1; $ln >= $first_line; $ln--) {
  				#print "CHECK<$lines[$ln - 1]
  ";
  				# we have a preceeding printk if it ends
  				# with "
  " ignore it, else it is to blame
  				if ($lines[$ln - 1] =~ m{\bprintk\(}) {
  					if ($rawlines[$ln - 1] !~ m{\
  "}) {
  						$ok = 1;
  					}
  					last;
  				}
  			}
  			if ($ok == 0) {

  				WARN("printk() should include KERN_ facility level
  " . $herecurr);

  			}

  		}

  # function brace can't be on same line, except for #defines of do while,
  # or if closed on same line

  		if (($line=~/$Type\s*[A-Za-z\d_]+\(.*\).* {/) and

  		    !($line=~/\#define.*do\s{/) and !($line=~/}/)) {

  			ERROR("open brace '{' following function declarations go on the next line
  " . $herecurr);

  		}

  # check for spaces between functions and their parentheses.
  		if ($line =~ /($Ident)\s+\(/ &&

  		    $1 !~ /^(?:if|for|while|switch|return|volatile|__volatile__|__attribute__|format|__extension__|Copyright)$/ &&

  		    $line !~ /$Type\s+\(/ && $line !~ /^.\#\s*define\b/) {

  			WARN("no space between function name and open parenthesis '('
  " . $herecurr);

  		}

  # Check operator spacing.

  		# Note we expand the line with the leading + as the real
  		# line will be displayed with the leading + and the tabs
  		# will therefore also expand that way.

  		my $opline = $line;

  		$opline = expand_tabs($opline);

  		$opline =~ s/^./ /;

  		if (!($line=~/\#\s*include/)) {

  			my @elements = split(/(<<=|>>=|<=|>=|==|!=|\+=|-=|\*=|\/=|%=|\^=|\|=|&=|=>|->|<<|>>|<|>|=|!|~|&&|\|\||,|\^|\+\+|--|;|&|\||\+|-|\*|\/\/|\/)/, $opline);

  			my $off = 0;

  			for (my $n = 0; $n < $#elements; $n += 2) {

  				$off += length($elements[$n]);
  
  				my $a = '';
  				$a = 'V' if ($elements[$n] ne '');
  				$a = 'W' if ($elements[$n] =~ /\s$/);
  				$a = 'B' if ($elements[$n] =~ /(\[|\()$/);
  				$a = 'O' if ($elements[$n] eq '');
  				$a = 'E' if ($elements[$n] eq '' && $n == 0);

  				my $op = $elements[$n + 1];

  
  				my $c = '';

  				if (defined $elements[$n + 2]) {

  					$c = 'V' if ($elements[$n + 2] ne '');
  					$c = 'W' if ($elements[$n + 2] =~ /^\s/);
  					$c = 'B' if ($elements[$n + 2] =~ /^(\)|\]|;)/);
  					$c = 'O' if ($elements[$n + 2] eq '');

  					$c = 'E' if ($elements[$n + 2] =~ /\s*\\$/);

  				} else {
  					$c = 'E';

  				}

  				# Pick up the preceeding and succeeding characters.

  				my $ca = substr($opline, 0, $off);

  				my $cc = '';

  				if (length($opline) >= ($off + length($elements[$n + 1]))) {

  					$cc = substr($opline, $off + length($elements[$n + 1]));

  				}

  				my $cb = "$ca$;$cc";

  				my $ctx = "${a}x${c}";
  
  				my $at = "(ctx:$ctx)";
  
  				my $ptr = (" " x $off) . "^";

  				my $hereptr = "$hereline$ptr
  ";

  
  				##print "<$s1:$op:$s2> <$elements[$n]:$elements[$n + 1]:$elements[$n + 2]>
  ";

  				# ; should have either the end of line or a space or \ after it
  				if ($op eq ';') {

  					if ($ctx !~ /.x[WEB]/ && $cc !~ /^\\/ &&
  					    $cc !~ /^;/) {
  						ERROR("need space after that '$op' $at
  " . $hereptr);

  					}
  
  				# // is a comment
  				} elsif ($op eq '//') {

  
  				# -> should have no spaces
  				} elsif ($op eq '->') {

  					if ($ctx =~ /Wx.|.xW/) {

  						ERROR("no spaces around that '$op' $at
  " . $hereptr);

  					}
  
  				# , must have a space on the right.
  				} elsif ($op eq ',') {

  					if ($ctx !~ /.xW|.xE/ && $cc !~ /^}/) {

  						ERROR("need space after that '$op' $at
  " . $hereptr);

  					}
  
  				# unary ! and unary ~ are allowed no space on the right
  				} elsif ($op eq '!' or $op eq '~') {

  					if ($ctx !~ /[WOEB]x./) {

  						ERROR("need space before that '$op' $at
  " . $hereptr);

  					}

  					if ($ctx =~ /.xW/) {

  						ERROR("no space after that '$op' $at
  " . $hereptr);

  					}
  
  				# unary ++ and unary -- are allowed no space on one side.
  				} elsif ($op eq '++' or $op eq '--') {

  					if ($ctx !~ /[WOB]x[^W]/ && $ctx !~ /[^W]x[WOBE]/) {

  						ERROR("need space one side of that '$op' $at
  " . $hereptr);

  					}

  					if ($ctx =~ /Wx./ && $cc =~ /^;/) {

  						ERROR("no space before that '$op' $at
  " . $hereptr);

  					}

  
  				# & is both unary and binary
  				# unary:
  				# 	a &b
  				# binary (consistent spacing):
  				#	a&b		OK
  				#	a & b		OK
  				#
  				# boiling down to: if there is a space on the right then there
  				# should be one on the left.
  				#
  				# - is the same
  				#

  				} elsif ($op eq '&' or $op eq '-') {

  					if ($ctx !~ /VxV|[EW]x[WE]|[EWB]x[VO]/) {

  						ERROR("need space before that '$op' $at
  " . $hereptr);

  					}

  				# * is the same as & only adding:
  				# type:
  				# 	(foo *)
  				#	(foo **)
  				#

  				} elsif ($op eq '*') {

  					if ($ca !~ /$Type$/ && $cb !~ /(\*$;|$;\*)/ &&
  					    $ctx !~ /VxV|[EW]x[WE]|[EWB]x[VO]|OxV|WxB|BxB/) {
  						ERROR("need space before that '$op' $at
  " . $hereptr);

  					}
  
  				# << and >> may either have or not have spaces both sides
  				} elsif ($op eq '<<' or $op eq '>>' or $op eq '+' or $op eq '/' or
  					 $op eq '^' or $op eq '|')
  				{

  					if ($ctx !~ /VxV|WxW|VxE|WxE/) {

  						ERROR("need consistent spacing around '$op' $at
  " .
  							$hereptr);

  					}
  
  				# All the others need spaces both sides.

  				} elsif ($ctx !~ /[EW]x[WE]/) {

  					# Ignore email addresses <foo@bar>
  					if (!($op eq '<' && $cb =~ /$;\S+\@\S+>/) &&
  					    !($op eq '>' && $cb =~ /<\S+\@\S+$;/)) {
  						ERROR("need spaces around that '$op' $at
  " . $hereptr);
  					}

  				}

  				$off += length($elements[$n + 1]);

  			}
  		}

  # check for multiple assignments
  		if ($line =~ /^.\s*$Lval\s*=\s*$Lval\s*=(?!=)/) {
  			WARN("multiple assignments should be avoided
  " . $herecurr);
  		}

  ## # check for multiple declarations, allowing for a function declaration
  ## # continuation.
  ## 		if ($line =~ /^.\s*$Type\s+$Ident(?:\s*=[^,{]*)?\s*,\s*$Ident.*/ &&
  ## 		    $line !~ /^.\s*$Type\s+$Ident(?:\s*=[^,{]*)?\s*,\s*$Type\s*$Ident.*/) {
  ##
  ## 			# Remove any bracketed sections to ensure we do not
  ## 			# falsly report the parameters of functions.
  ## 			my $ln = $line;
  ## 			while ($ln =~ s/\([^\(\)]*\)//g) {
  ## 			}
  ## 			if ($ln =~ /,/) {
  ## 				WARN("declaring multiple variables together should be avoided
  " . $herecurr);
  ## 			}
  ## 		}

  #need space before brace following if, while, etc

  		if (($line =~ /\(.*\){/ && $line !~ /\($Type\){/) ||
  		    $line =~ /do{/) {

  			ERROR("need a space before the open brace '{'
  " . $herecurr);
  		}
  
  # closing brace should have a space following it when it has anything
  # on the line
  		if ($line =~ /}(?!(?:,|;|\)))\S/) {
  			ERROR("need a space after that close brace '}'
  " . $herecurr);

  		}

  # check spacing on square brackets
  		if ($line =~ /\[\s/ && $line !~ /\[\s*$/) {
  			ERROR("no space after that open square bracket '['
  " . $herecurr);
  		}
  		if ($line =~ /\s\]/) {
  			ERROR("no space before that close square bracket ']'
  " . $herecurr);
  		}
  
  # check spacing on paretheses
  		if ($line =~ /\(\s/ && $line !~ /\(\s*$/) {
  			ERROR("no space after that open parenthesis '('
  " . $herecurr);
  		}
  		if ($line =~ /\s\)/) {
  			ERROR("no space before that close parenthesis ')'
  " . $herecurr);
  		}

  #goto labels aren't indented, allow a single space however

  		if ($line=~/^.\s+[A-Za-z\d_]+:(?![0-9]+)/ and

  		   !($line=~/^. [A-Za-z\d_]+:/) and !($line=~/^.\s+default:/)) {

  			WARN("labels should not be indented
  " . $herecurr);

  		}
  
  # Need a space before open parenthesis after if, while etc

  		if ($line=~/\b(if|while|for|switch)\(/) {

  			ERROR("need a space before the open parenthesis '('
  " . $herecurr);

  		}
  
  # Check for illegal assignment in if conditional.

  		if ($line=~/\bif\s*\(.*[^<>!=]=[^=].*\)/) {

  			#next if ($line=~/\".*\Q$op\E.*\"/ or $line=~/\'\Q$op\E\'/);

  			ERROR("do not use assignment in if condition
  " . $herecurr);

  		}
  
  		# Check for }<nl>else {, these must be at the same
  		# indent level to be relevant to each other.
  		if ($prevline=~/}\s*$/ and $line=~/^.\s*else\s*/ and
  						$previndent == $indent) {

  			ERROR("else should follow close brace '}'
  " . $hereprev);

  		}

  #studly caps, commented out until figure out how to distinguish between use of existing and adding new
  #		if (($line=~/[\w_][a-z\d]+[A-Z]/) and !($line=~/print/)) {
  #		    print "No studly caps, use _
  ";
  #		    print "$herecurr";
  #		    $clean = 0;
  #		}
  
  #no spaces allowed after \ in define
  		if ($line=~/\#define.*\\\s$/) {

  			WARN("Whitepspace after \\ makes next lines useless
  " . $herecurr);

  		}

  #warn if <asm/foo.h> is #included and <linux/foo.h> is available (uses RAW line)
  		if ($tree && $rawline =~ m{^.\#\s*include\s*\<asm\/(.*)\.h\>}) {

  			my $checkfile = "include/linux/$1.h";
  			if (-f $checkfile) {

  				CHK("Use #include <linux/$1.h> instead of <asm/$1.h>
  " .
  					$herecurr);

  			}
  		}

  # if and else should not have general statements after it
  		if ($line =~ /^.\s*(?:}\s*)?else\b(.*)/ &&

  		    $1 !~ /^\s*(?:\sif|{|\\|$)/) {
  			ERROR("trailing statements should be on next line
  " . $herecurr);

  		}

  # multi-statement macros should be enclosed in a do while loop, grab the
  # first statement and ensure its the whole macro if its not enclosed
  # in a known goot container
  		if (($prevline=~/\#define.*\\/) and
  		   !($prevline=~/do\s+{/) and !($prevline=~/\(\{/) and
  		   !($line=~/do.*{/) and !($line=~/\(\{/) and
  		   !($line=~/^.\s*$Declare\s/)) {
  			# Grab the first statement, if that is the entire macro
  			# its ok.  This may start either on the #define line
  			# or the one below.

  			my $ln = $linenr;
  			my $cnt = $realcnt;

  			my $off = 0;

  			# If the macro starts on the define line start
  			# grabbing the statement after the identifier
  			$prevline =~ m{^(.#\s*define\s*$Ident(?:\([^\)]*\))?\s*)(.*)\\\s*$};
  			##print "1<$1> 2<$2>
  ";

  			if (defined $2 && $2 ne '') {

  				$off = length($1);

  				$ln--;
  				$cnt++;
  			}

  			my @ctx = ctx_statement($ln, $cnt, $off);

  			my $ctx_ln = $ln + $#ctx + 1;
  			my $ctx = join("
  ", @ctx);
  
  			# Pull in any empty extension lines.
  			while ($ctx =~ /\\$/ &&
  			       $lines[$ctx_ln - 1] =~ /^.\s*(?:\\)?$/) {
  				$ctx .= $lines[$ctx_ln - 1];
  				$ctx_ln++;
  			}

  
  			if ($ctx =~ /\\$/) {
  				if ($ctx =~ /;/) {

  					ERROR("Macros with multiple statements should be enclosed in a do - while loop
  " . "$here
  $ctx
  ");

  				} else {

  					ERROR("Macros with complex values should be enclosed in parenthesis
  " . "$here
  $ctx
  ");

  				}

  			}

  		}

  # check for redundant bracing round if etc
  		if ($line =~ /\b(if|while|for|else)\b/) {
  			# Locate the end of the opening statement.
  			my @control = ctx_statement($linenr, $realcnt, 0);
  			my $nr = $linenr + (scalar(@control) - 1);
  			my $cnt = $realcnt - (scalar(@control) - 1);
  
  			my $off = $realcnt - $cnt;
  			#print "$off: line<$line>end<" . $lines[$nr - 1] . ">
  ";
  
  			# If this is is a braced statement group check it
  			if ($lines[$nr - 1] =~ /{\s*$/) {
  				my ($lvl, @block) = ctx_block_level($nr, $cnt);
  
  				my $stmt = join(' ', @block);

  				$stmt =~ s/(^[^{]*){//;
  				my $before = $1;
  				$stmt =~ s/}([^}]*$)//;
  				my $after = $1;

  
  				#print "block<" . join(' ', @block) . "><" . scalar(@block) . ">
  ";
  				#print "stmt<$stmt>
  
  ";
  
  				# Count the ;'s if there is fewer than two
  				# then there can only be one statement,
  				# if there is a brace inside we cannot
  				# trivially detect if its one statement.
  				# Also nested if's often require braces to
  				# disambiguate the else binding so shhh there.
  				my @semi = ($stmt =~ /;/g);

  				push(@semi, "/**/") if ($stmt =~ m@/\*@);

  				##print "semi<" . scalar(@semi) . ">
  ";
  				if ($lvl == 0 && scalar(@semi) < 2 &&

  				    $stmt !~ /{/ && $stmt !~ /\bif\b/ &&
  				    $before !~ /}/ && $after !~ /{/) {

  				    	my $herectx = "$here
  " . join("
  ", @control, @block[1 .. $#block]) . "
  ";
  				    	shift(@block);

  					WARN("braces {} are not necessary for single statement blocks
  " . $herectx);

  				}
  			}
  		}

  # don't include deprecated include files (uses RAW line)

  		for my $inc (@dep_includes) {

  			if ($rawline =~ m@\#\s*include\s*\<$inc>@) {

  				ERROR("Don't use <$inc>: see Documentation/feature-removal-schedule.txt
  " . $herecurr);

  			}
  		}

  # don't use deprecated functions
  		for my $func (@dep_functions) {

  			if ($line =~ /\b$func\b/) {

  				ERROR("Don't use $func(): see Documentation/feature-removal-schedule.txt
  " . $herecurr);

  			}
  		}
  
  # no volatiles please

  		if ($line =~ /\bvolatile\b/ && $line !~ /\basm\s+volatile\b/) {

  			WARN("Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
  " . $herecurr);

  		}

  # warn about #if 0
  		if ($line =~ /^.#\s*if\s+0\b/) {

  			CHK("if this code is redundant consider removing it
  " .
  				$herecurr);

  		}

  # check for needless kfree() checks
  		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
  			my $expr = $1;
  			if ($line =~ /\bkfree\(\Q$expr\E\);/) {
  				WARN("kfree(NULL) is safe this check is probabally not required
  " . $hereprev);
  			}
  		}

  # warn about #ifdefs in C files
  #		if ($line =~ /^.#\s*if(|n)def/ && ($realfile =~ /\.c$/)) {
  #			print "#ifdef in C files should be avoided
  ";
  #			print "$herecurr";
  #			$clean = 0;
  #		}

  # warn about spacing in #ifdefs
  		if ($line =~ /^.#\s*(ifdef|ifndef|elif)\s\s+/) {
  			ERROR("exactly one space required after that #$1
  " . $herecurr);
  		}

  # check for spinlock_t definitions without a comment.
  		if ($line =~ /^.\s*(struct\s+mutex|spinlock_t)\s+\S+;/) {
  			my $which = $1;
  			if (!ctx_has_comment($first_line, $linenr)) {

  				CHK("$1 definition without comment
  " . $herecurr);

  			}
  		}
  # check for memory barriers without a comment.
  		if ($line =~ /\b(mb|rmb|wmb|read_barrier_depends|smp_mb|smp_rmb|smp_wmb|smp_read_barrier_depends)\(/) {
  			if (!ctx_has_comment($first_line, $linenr)) {

  				CHK("memory barrier without comment
  " . $herecurr);

  			}
  		}
  # check of hardware specific defines

  		if ($line =~ m@^.#\s*if.*\b(__i386__|__powerpc64__|__sun__|__s390x__)\b@ && $realfile !~ m@include/asm-@) {

  			CHK("architecture specific defines should be avoided
  " .  $herecurr);

  		}

  # check the location of the inline attribute, that it is between
  # storage class and type.

  		if ($line =~ /$Type\s+(?:inline|__always_inline|noinline)\b/ ||
  		    $line =~ /\b(?:inline|__always_inline|noinline)\s+$Storage/) {

  			ERROR("inline keyword should sit between storage class and type
  " . $herecurr);
  		}
  
  # check for new externs in .c files.
  		if ($line =~ /^.\s*extern\s/ && ($realfile =~ /\.c$/)) {
  			WARN("externs should be avoided in .c files
  " .  $herecurr);
  		}
  
  # checks for new __setup's
  		if ($rawline =~ /\b__setup\("([^"]*)"/) {
  			my $name = $1;
  
  			if (!grep(/$name/, @setup_docs)) {
  				CHK("__setup appears un-documented -- check Documentation/kernel-parameters.txt
  " . $herecurr);
  			}

  		}

  	}
  
  	if ($chk_patch && !$is_patch) {

  		ERROR("Does not appear to be a unified-diff format patch
  ");

  	}
  	if ($is_patch && $chk_signoff && $signoff == 0) {

  		ERROR("Missing Signed-off-by: line(s)
  ");

  	}

  	if ($clean == 0 && ($chk_patch || $is_patch)) {
  		print report_dump();
  	}

  	if ($clean == 1 && $quiet == 0) {
  		print "Your patch has no obvious style problems and is ready for submission.
  "
  	}
  	if ($clean == 0 && $quiet == 0) {
  		print "Your patch has style problems, please review.  If any of these errors
  ";
  		print "are false positives report them to the maintainer, see
  ";
  		print "CHECKPATCH in MAINTAINERS.
  ";
  	}
  	return $clean;
  }