checkpatch.pl

# new versions of GNU diff omit the leading space on completely
# blank context lines so we need to count that too.
		} elsif ($line =~ /^( |\+|$)/) {
			$realline++;
			$realcnt-- if ($realcnt != 0);

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

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

			#warn "line<$line>\n";

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

#make up the handle for any error we report on this line
		$prefix = "$filename:$realline: " if ($emacs && $file);
		$prefix = "$filename:$linenr: " if ($emacs && !$file);

		$here = "#$linenr: " if (!$file);
		$here = "#$realline: " if ($file);

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

			if ($realfile =~ m@include/asm/@) {
				ERROR("do not modify files in include/asm, change architecture specific files in include/asm-<architecture>\n" . "$here$rawline\n");
			}
			next;
		}

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

		my $hereline = "$here\n$rawline\n";
		my $herecurr = "$here\n$rawline\n";
		my $hereprev = "$here\n$prevrawline\n$rawline\n";

		$cnt_lines++ if ($realcnt != 0);

#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\n" .
					$herecurr);
			}
			if ($line =~ /^\s*signed-off-by:\S/i) {
				WARN("space required after Signed-off-by:\n" .
					$herecurr);
			}
		}

# Check for wrappage within a valid hunk of the file
		if ($realcnt != 0 && $line !~ m{^(?:\+|-| |\\ No newline|$)}) {
			ERROR("patch seems to be corrupt (line wrapped?)\n" .
				$herecurr) if (!$emitted_corrupt++);
		}

# UTF-8 regex found at http://www.w3.org/International/questions/qa-forms-utf-8.en.php
		if (($realfile =~ /^$/ || $line =~ /^\+/) &&
		     !($rawline =~ 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, patch and commit message should be encoded in UTF-8\n" . $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 =~ /^\+.*\015/) {
			my $herevet = "$here\n" . cat_vet($rawline) . "\n";
			ERROR("DOS line endings\n" . $herevet);

		} elsif ($rawline =~ /^\+.*\S\s+$/ || $rawline =~ /^\+\s+$/) {
			my $herevet = "$here\n" . cat_vet($rawline) . "\n";
			ERROR("trailing whitespace\n" . $herevet);
		}
#80 column limit
		if ($line =~ /^\+/ && !($prevrawline=~/\/\*\*/) && $length > 80) {
			WARN("line over 80 characters\n" . $herecurr);
		}

# check for adding lines without a newline.
		if ($line =~ /^\+/ && defined $lines[$linenr] && $lines[$linenr] =~ /^\\ No newline at end of file/) {
			WARN("adding a line without newline at end of file\n" . $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 ($rawline =~ /^\+\s* \t\s*\S/ ||
		    $rawline =~ /^\+\s*        \s*/) {
			my $herevet = "$here\n" . cat_vet($rawline) . "\n";
			ERROR("use tabs not spaces\n" . $herevet);
		}

# check for RCS/CVS revision markers
		if ($rawline =~ /^\+.*\$(Revision|Log|Id)(?:\$|)/) {
			WARN("CVS style keyword markers, these will _not_ be updated\n". $herecurr);
		}

# Check for potential 'bare' types
		if ($realcnt) {
			my ($s, $c) = ctx_statement_block($linenr, $realcnt, 0);
			$s =~ s/\n./ /g;
			$s =~ s/{.*$//;

			# Ignore goto labels.
			if ($s =~ /$Ident:\*$/) {

			# Ignore functions being called
			} elsif ($s =~ /^.\s*$Ident\s*\(/) {

			# definitions in global scope can only start with types
			} elsif ($s =~ /^.(?:$Storage\s+)?(?:$Inline\s+)?(?:const\s+)?($Ident)\b/) {
				possible($1, $s);

			# declarations always start with types
			} elsif ($prev_values eq 'E' && $s =~ /^.\s*(?:$Storage\s+)?(?:const\s+)?($Ident)\b(:?\s+$Sparse)?\s*\**\s*$Ident\s*(?:;|=|,)/) {
				possible($1, $s);
			}

			# any (foo ... *) is a pointer cast, and foo is a type
			while ($s =~ /\(($Ident)(?:\s+$Sparse)*\s*\*+\s*\)/g) {
				possible($1, $s);
			}

			# Check for any sort of function declaration.
			# int foo(something bar, other baz);
			# void (*store_gdt)(x86_descr_ptr *);
			if ($prev_values eq 'E' && $s =~ /^(.(?:typedef\s*)?(?:(?:$Storage|$Inline)\s*)*\s*$Type\s*(?:\b$Ident|\(\*\s*$Ident\))\s*)\(/) {
				my ($name_len) = length($1);

				my $ctx = $s;
				substr($ctx, 0, $name_len + 1, '');
				$ctx =~ s/\)[^\)]*$//;

				for my $arg (split(/\s*,\s*/, $ctx)) {
					if ($arg =~ /^(?:const\s+)?($Ident)(?:\s+$Sparse)*\s*\**\s*(:?\b$Ident)?$/ || $arg =~ /^($Ident)$/) {

						possible($1, $s);
					}
				}
			}

		}

#
# 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\n";
					$sep = '';
				} else {
					$sep = "[...]\n";
				}
			}
			if ($err ne '') {
				ERROR("switch and case should be at the same indent\n$hereline$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 $pre_ctx = "$1$2";

			my ($level, @ctx) = ctx_statement_level($linenr, $realcnt, 0);
			my $ctx_ln = $linenr + $#ctx + 1;
			my $ctx_cnt = $realcnt - $#ctx - 1;
			my $ctx = join("\n", @ctx);

			##warn "realcnt<$realcnt> ctx_cnt<$ctx_cnt>\n";

			# Skip over any removed lines in the context following statement.
			while (defined($lines[$ctx_ln - 1]) && $lines[$ctx_ln - 1] =~ /^-/) {
				$ctx_ln++;
			}
			##warn "pre<$pre_ctx>\nline<$line>\nctx<$ctx>\nnext<$lines[$ctx_ln - 1]>\n";

			if ($ctx !~ /{\s*/ && defined($lines[$ctx_ln -1]) && $lines[$ctx_ln - 1] =~ /^\+\s*{/) {
				ERROR("that open brace { should be on the previous line\n" .
					"$here\n$ctx\n$lines[$ctx_ln - 1]");
			}
			if ($level == 0 && $pre_ctx !~ /}\s*while\s*\($/ &&
			    $ctx =~ /\)\s*\;\s*$/ &&
			    defined $lines[$ctx_ln - 1])
			{
				my ($nlength, $nindent) = line_stats($lines[$ctx_ln - 1]);
				if ($nindent > $indent) {
					WARN("trailing semicolon indicates no statements, indent implies otherwise\n" .
						"$here\n$ctx\n$lines[$ctx_ln - 1]");
				}
			}
		}

		# Track the 'values' across context and added lines.
		my $opline = $line; $opline =~ s/^./ /;
		my $curr_values = annotate_values($opline . "\n", $prev_values);
		$curr_values = $prev_values . $curr_values;
		if ($dbg_values) {
			my $outline = $opline; $outline =~ s/\t/ /g;
			print "$linenr > .$outline\n";
			print "$linenr > $curr_values\n";
		}
		$prev_values = substr($curr_values, -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\n" . $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\n" . $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\n" .
					$herecurr);
			}
		}

# no C99 // comments
		if ($line =~ m{//}) {
			ERROR("do not use C99 // comments\n" . $herecurr);
		}
		# Remove C99 comments.
		$line =~ s@//.*@@;
		$opline =~ s@//.*@@;

#EXPORT_SYMBOL should immediately follow its function closing }.
		if (($line =~ /EXPORT_SYMBOL.*\((.*)\)/) ||
		    ($line =~ /EXPORT_UNUSED_SYMBOL.*\((.*)\)/)) {
			my $name = $1;
			if (($prevline !~ /^}/) &&
			   ($prevline !~ /^\+}/) &&
			   ($prevline !~ /^ }/) &&
			   ($prevline !~ /^.DECLARE_$Ident\(\Q$name\E\)/) &&
			   ($prevline !~ /^.LIST_HEAD\(\Q$name\E\)/) &&
			   ($prevline !~ /\b\Q$name\E(?:\s+$Attribute)?\s*(?:;|=|\[)/)) {
				WARN("EXPORT_SYMBOL(foo); should immediately follow its function/variable\n" . $herecurr);
			}
		}

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

# * goes on variable not on type
		if ($line =~ m{\($NonptrType(\*+)(?:\s+const)?\)}) {
			ERROR("\"(foo$1)\" should be \"(foo $1)\"\n" .
				$herecurr);

		} elsif ($line =~ m{\($NonptrType\s+(\*+)(?!\s+const)\s+\)}) {
			ERROR("\"(foo $1 )\" should be \"(foo $1)\"\n" .
				$herecurr);

		} elsif ($line =~ m{$NonptrType(\*+)(?:\s+(?:$Attribute|$Sparse))?\s+[A-Za-z\d_]+}) {
			ERROR("\"foo$1 bar\" should be \"foo $1bar\"\n" .
				$herecurr);

		} elsif ($line =~ m{$NonptrType\s+(\*+)(?!\s+(?:$Attribute|$Sparse))\s+[A-Za-z\d_]+}) {
			ERROR("\"foo $1 bar\" should be \"foo $1bar\"\n" .
				$herecurr);
		}

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

		if ($line =~ /\bLINUX_VERSION_CODE\b/) {
			WARN("LINUX_VERSION_CODE should be avoided, code should be for the version to which it is merged\n" . $herecurr);
		}

# 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[$ln - 1]\n";
				# we have a preceeding printk if it ends
				# with "\n" ignore it, else it is to blame
				if ($lines[$ln - 1] =~ m{\bprintk\(}) {
					if ($rawlines[$ln - 1] !~ m{\\n"}) {
						$ok = 1;
					}
					last;
				}
			}
			if ($ok == 0) {
				WARN("printk() should include KERN_ facility level\n" . $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_]+\(.*\).*\s{/) and
		    !($line=~/\#define.*do\s{/) and !($line=~/}/)) {
			ERROR("open brace '{' following function declarations go on the next line\n" . $herecurr);
		}

# open braces for enum, union and struct go on the same line.
		if ($line =~ /^.\s*{/ &&
		    $prevline =~ /^.\s*(?:typedef\s+)?(enum|union|struct)(?:\s+$Ident)?\s*$/) {
			ERROR("open brace '{' following $1 go on the same line\n" . $hereprev);
		}

# check for spaces between functions and their parentheses.
		while ($line =~ /($Ident)\s+\(/g) {
			my $name = $1;
			my $ctx_before = substr($line, 0, $-[1]);
			my $ctx = "$ctx_before$name";

			# Ignore those directives where spaces _are_ permitted.
			if ($name =~ /^(?:
				if|for|while|switch|return|case|
				volatile|__volatile__|
				__attribute__|format|__extension__|
				asm|__asm__)$/x)
			{

			# cpp #define statements have non-optional spaces, ie
			# if there is a space between the name and the open
			# parenthesis it is simply not a parameter group.
			} elsif ($ctx_before =~ /^.\#\s*define\s*$/) {

			# cpp #elif statement condition may start with a (
			} elsif ($ctx =~ /^.\#\s*elif\s*$/) {

			# If this whole things ends with a type its most
			# likely a typedef for a function.
			} elsif ($ctx =~ /$Type$/) {

			} else {
				WARN("space prohibited between function name and open parenthesis '('\n" . $herecurr);
			}
		}
# Check operator spacing.
		if (!($line=~/\#\s*include/)) {
			my $ops = qr{
				<<=|>>=|<=|>=|==|!=|
				\+=|-=|\*=|\/=|%=|\^=|\|=|&=|
				=>|->|<<|>>|<|>|=|!|~|
				&&|\|\||,|\^|\+\+|--|&|\||\+|-|\*|\/|%
			}x;
			my @elements = split(/($ops|;)/, $opline);
			my $off = 0;

			my $blank = copy_spacing($opline);

			for (my $n = 0; $n < $#elements; $n += 2) {
				$off += length($elements[$n]);

				# 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 $a = '';
				$a = 'V' if ($elements[$n] ne '');
				$a = 'W' if ($elements[$n] =~ /\s$/);
				$a = 'C' if ($elements[$n] =~ /$;$/);
				$a = 'B' if ($elements[$n] =~ /(\[|\()$/);
				$a = 'O' if ($elements[$n] eq '');
				$a = 'E' if ($ca =~ /^\s*$/);

				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/);
					$c = 'C' if ($elements[$n + 2] =~ /^$;/);
					$c = 'B' if ($elements[$n + 2] =~ /^(\)|\]|;)/);
					$c = 'O' if ($elements[$n + 2] eq '');
					$c = 'E' if ($elements[$n + 2] =~ /\s*\\$/);
				} else {
					$c = 'E';
				}

				my $ctx = "${a}x${c}";

				my $at = "(ctx:$ctx)";

				my $ptr = substr($blank, 0, $off) . "^";
				my $hereptr = "$hereline$ptr\n";

				# Classify operators into binary, unary, or
				# definitions (* only) where they have more
				# than one mode.
				my $op_type = substr($curr_values, $off + 1, 1);
				my $op_left = substr($curr_values, $off, 1);
				my $is_unary;
				if ($op_type eq 'T') {
					$is_unary = 2;
				} elsif ($op_left eq 'V') {
					$is_unary = 0;
				} else {
					$is_unary = 1;
				}
				#if ($op eq '-' || $op eq '&' || $op eq '*') {
				#	print "UNARY: <$op_left$op_type $is_unary $a:$op:$c> <$ca:$op:$cc> <$unary_ctx>\n";
				#}

				# Ignore operators passed as parameters.
				if ($op_type ne 'V' &&
				    $ca =~ /\s$/ && $cc =~ /^\s*,/) {

#				# Ignore comments
#				} elsif ($op =~ /^$;+$/) {

				# ; should have either the end of line or a space or \ after it
				} elsif ($op eq ';') {
					if ($ctx !~ /.x[WEBC]/ &&
					    $cc !~ /^\\/ && $cc !~ /^;/) {
						ERROR("space required after that '$op' $at\n" . $hereptr);
					}

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

				# -> should have no spaces
				} elsif ($op eq '->') {
					if ($ctx =~ /Wx.|.xW/) {
						ERROR("spaces prohibited around that '$op' $at\n" . $hereptr);
					}

				# , must have a space on the right.
				} elsif ($op eq ',') {
					if ($ctx !~ /.x[WEC]/ && $cc !~ /^}/) {
						ERROR("space required after that '$op' $at\n" . $hereptr);
					}

				# '*' as part of a type definition -- reported already.
				} elsif ($op eq '*' && $is_unary == 2) {
					#warn "'*' is part of type\n";

				# unary operators should have a space before and
				# none after.  May be left adjacent to another
				# unary operator, or a cast
				} elsif ($op eq '!' || $op eq '~' ||
				         ($is_unary && ($op eq '*' || $op eq '-' || $op eq '&'))) {
					if ($ctx !~ /[WEBC]x./ && $ca !~ /(?:\)|!|~|\*|-|\&|\||\+\+|\-\-|\{)$/) {
						ERROR("space required before that '$op' $at\n" . $hereptr);
					}
					if ($ctx =~ /.xW/) {
						ERROR("space prohibited after that '$op' $at\n" . $hereptr);
					}

				# unary ++ and unary -- are allowed no space on one side.
				} elsif ($op eq '++' or $op eq '--') {
					if ($ctx !~ /[WEOBC]x[^W]/ && $ctx !~ /[^W]x[WOBEC]/) {
						ERROR("space required one side of that '$op' $at\n" . $hereptr);
					}
					if ($ctx =~ /Wx[BE]/ ||
					    ($ctx =~ /Wx./ && $cc =~ /^;/)) {
						ERROR("space prohibited before that '$op' $at\n" . $hereptr);
					}
					if ($ctx =~ /ExW/) {
						ERROR("space prohibited after that '$op' $at\n" . $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 '+' or $op eq '-' or
					 $op eq '*' or $op eq '/' or
					 $op eq '%')
				{
					if ($ctx =~ /Wx[^WCE]|[^WCE]xW/) {
						ERROR("need consistent spacing around '$op' $at\n" .
							$hereptr);
					}

				# All the others need spaces both sides.
				} elsif ($ctx !~ /[EWC]x[CWE]/) {
					# Ignore email addresses <foo@bar>
					if (!($op eq '<' && $cb =~ /$;\S+\@\S+>/) &&
					    !($op eq '>' && $cb =~ /<\S+\@\S+$;/)) {
						ERROR("spaces required around that '$op' $at\n" . $hereptr);
					}
				}
				$off += length($elements[$n + 1]);
			}
		}

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

#need space before brace following if, while, etc
		if (($line =~ /\(.*\){/ && $line !~ /\($Type\){/) ||
		    $line =~ /do{/) {
			ERROR("space required before the open brace '{'\n" . $herecurr);
		}

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

# check spacing on square brackets
		if ($line =~ /\[\s/ && $line !~ /\[\s*$/) {
			ERROR("space prohibited after that open square bracket '['\n" . $herecurr);
		}
		if ($line =~ /\s\]/) {
			ERROR("space prohibited before that close square bracket ']'\n" . $herecurr);
		}

# check spacing on paretheses
		if ($line =~ /\(\s/ && $line !~ /\(\s*(?:\\)?$/ &&
		    $line !~ /for\s*\(\s+;/) {
			ERROR("space prohibited after that open parenthesis '('\n" . $herecurr);
		}
		if ($line =~ /(\s+)\)/ && $line !~ /^.\s*\)/ &&
		    $line !~ /for\s*\(.*;\s+\)/) {
			ERROR("space prohibited before that close parenthesis ')'\n" . $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\n" . $herecurr);
		}

# Need a space before open parenthesis after if, while etc
		if ($line=~/\b(if|while|for|switch)\(/) {
			ERROR("space required before the open parenthesis '('\n" . $herecurr);
		}

# Check for illegal assignment in if conditional.
		if ($line =~ /\bif\s*\(/) {
			my ($s, $c) = ctx_statement_block($linenr, $realcnt, 0);

			if ($c =~ /\bif\s*\(.*[^<>!=]=[^=].*/) {
				ERROR("do not use assignment in if condition\n" . $herecurr);
			}

			# Find out what is on the end of the line after the
			# conditional.
			substr($s, 0, length($c), '');
			$s =~ s/\n.*//g;
			$s =~ s/$;//g; 	# Remove any comments
			if (length($c) && $s !~ /^\s*({|;|)\s*\\*\s*$/ &&
			    $c !~ /^.\#\s*if/)
			{
				ERROR("trailing statements should be on next line\n" . $herecurr);
			}
		}

# Check for bitwise tests written as boolean
		if ($line =~ /
			(?:
				(?:\[|\(|\&\&|\|\|)
				\s*0[xX][0-9]+\s*
				(?:\&\&|\|\|)
			|
				(?:\&\&|\|\|)
				\s*0[xX][0-9]+\s*
				(?:\&\&|\|\||\)|\])
			)/x)
		{
			WARN("boolean test with hexadecimal, perhaps just 1 \& or \|?\n" . $herecurr);
		}

# if and else should not have general statements after it
		if ($line =~ /^.\s*(?:}\s*)?else\b(.*)/) {
			my $s = $1;
			$s =~ s/$;//g; 	# Remove any comments
			if ($s !~ /^\s*(?:\sif|(?:{|)\s*\\?\s*$)/) {
				ERROR("trailing statements should be on next line\n" . $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 '}'\n" . $hereprev);
		}

		if ($prevline=~/}\s*$/ and $line=~/^.\s*while\s*/ and
						$previndent == $indent) {
			my ($s, $c) = ctx_statement_block($linenr, $realcnt, 0);

			# Find out what is on the end of the line after the
			# conditional.
			substr($s, 0, length($c), '');
			$s =~ s/\n.*//g;

			if ($s =~ /^\s*;/) {
				ERROR("while should follow close brace '}'\n" . $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 _\n";
#		    print "$herecurr";
#		    $clean = 0;
#		}

#no spaces allowed after \ in define
		if ($line=~/\#define.*\\\s$/) {
			WARN("Whitepspace after \\ makes next lines useless\n" . $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 $checkfile = "$root/include/linux/$1.h";
			if (-f $checkfile && $1 ne 'irq.h') {
				WARN("Use #include <linux/$1.h> instead of <asm/$1.h>\n" .
					$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 good container
		if ($prevline =~ /\#define.*\\/ &&
		   $prevline !~/(?:do\s+{|\(\{|\{)/ &&
		   $line !~ /(?:do\s+{|\(\{|\{)/ &&
		   $line !~ /^.\s*$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>\n";
			if (defined $2 && $2 ne '') {
				$off = length($1);
				$ln--;
				$cnt++;
				while ($lines[$ln - 1] =~ /^-/) {
					$ln--;
					$cnt++;
				}
			}
			my @ctx = ctx_statement($ln, $cnt, $off);
			my $ctx_ln = $ln + $#ctx + 1;
			my $ctx = join("\n", @ctx);

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

			if ($ctx =~ /\\$/) {
				if ($ctx =~ /;/) {
					ERROR("Macros with multiple statements should be enclosed in a do - while loop\n" . "$here\n$ctx\n");
				} else {
					ERROR("Macros with complex values should be enclosed in parenthesis\n" . "$here\n$ctx\n");
				}
			}
		}

# check for redundant bracing round if etc
		if ($line =~ /(^.*)\bif\b/ && $1 !~ /else\s*$/) {
			my ($level, $endln, @chunks) =
				ctx_statement_full($linenr, $realcnt, 1);
			#print "chunks<$#chunks> linenr<$linenr> endln<$endln> level<$level>\n";
			#print "APW: <<$chunks[1][0]>><<$chunks[1][1]>>\n";
			if ($#chunks > 0 && $level == 0) {
				my $allowed = 0;
				my $seen = 0;
				my $herectx = $here . "\n";
				my $ln = $linenr - 1;
				for my $chunk (@chunks) {
					my ($cond, $block) = @{$chunk};

					# If the condition carries leading newlines, then count those as offsets.
					my ($whitespace) = ($cond =~ /^((?:\s*\n[+-])*\s*)/s);
					my $offset = statement_rawlines($whitespace) - 1;

					#print "COND<$cond> whitespace<$whitespace> offset<$offset>\n";

					# We have looked at and allowed this specific line.
					$suppress_ifbraces{$ln + $offset} = 1;

					$herectx .= "$rawlines[$ln + $offset]\n[...]\n";
					$ln += statement_rawlines($block) - 1;

					substr($block, 0, length($cond), '');

					$seen++ if ($block =~ /^\s*{/);

					#print "cond<$cond> block<$block> allowed<$allowed>\n";
					if (statement_lines($cond) > 1) {
						#print "APW: ALLOWED: cond<$cond>\n";
						$allowed = 1;
					}
					if ($block =~/\b(?:if|for|while)\b/) {
						#print "APW: ALLOWED: block<$block>\n";
						$allowed = 1;
					}
					if (statement_block_size($block) > 1) {
						#print "APW: ALLOWED: lines block<$block>\n";
						$allowed = 1;
					}
				}
				if ($seen && !$allowed) {
					WARN("braces {} are not necessary for any arm of this statement\n" . $herectx);
				}
			}
		}
		if (!defined $suppress_ifbraces{$linenr - 1} &&
					$line =~ /\b(if|while|for|else)\b/) {
			my $allowed = 0;

			# Check the pre-context.
			if (substr($line, 0, $-[0]) =~ /(\}\s*)$/) {
				#print "APW: ALLOWED: pre<$1>\n";
				$allowed = 1;
			}

			my ($level, $endln, @chunks) =
				ctx_statement_full($linenr, $realcnt, $-[0]);

			# Check the condition.
			my ($cond, $block) = @{$chunks[0]};
			#print "CHECKING<$linenr> cond<$cond> block<$block>\n";
			if (defined $cond) {
				substr($block, 0, length($cond), '');
			}
			if (statement_lines($cond) > 1) {
				#print "APW: ALLOWED: cond<$cond>\n";
				$allowed = 1;
			}
			if ($block =~/\b(?:if|for|while)\b/) {
				#print "APW: ALLOWED: block<$block>\n";
				$allowed = 1;
			}
			if (statement_block_size($block) > 1) {
				#print "APW: ALLOWED: lines block<$block>\n";
				$allowed = 1;
			}
			# Check the post-context.
			if (defined $chunks[1]) {
				my ($cond, $block) = @{$chunks[1]};
				if (defined $cond) {
					substr($block, 0, length($cond), '');
				}
				if ($block =~ /^\s*\{/) {
					#print "APW: ALLOWED: chunk-1 block<$block>\n";
					$allowed = 1;
				}
			}
			if ($level == 0 && $block =~ /^\s*\{/ && !$allowed) {
				my $herectx = $here . "\n";;
				my $end = $linenr + statement_rawlines($block) - 1;

				for (my $ln = $linenr - 1; $ln < $end; $ln++) {
					$herectx .= $rawlines[$ln] . "\n";;
				}

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

# no volatiles please
		my $asm_volatile = qr{\b(__asm__|asm)\s+(__volatile__|volatile)\b};
		if ($line =~ /\bvolatile\b/ && $line !~ /$asm_volatile/) {
			WARN("Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt\n" . $herecurr);
		}

# SPIN_LOCK_UNLOCKED & RW_LOCK_UNLOCKED are deprecated
		if ($line =~ /\b(SPIN_LOCK_UNLOCKED|RW_LOCK_UNLOCKED)/) {
			ERROR("Use of $1 is deprecated: see Documentation/spinlocks.txt\n" . $herecurr);
		}

# warn about #if 0
		if ($line =~ /^.#\s*if\s+0\b/) {
			CHK("if this code is redundant consider removing it\n" .
				$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\n" . $hereprev);
			}
		}
# check for needless usb_free_urb() checks
		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
			my $expr = $1;
			if ($line =~ /\busb_free_urb\(\Q$expr\E\);/) {
				WARN("usb_free_urb(NULL) is safe this check is probabally not required\n" . $hereprev);
			}
		}

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

# warn about spacing in #ifdefs
		if ($line =~ /^.#\s*(ifdef|ifndef|elif)\s\s+/) {
			ERROR("exactly one space required after that #$1\n" . $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\n" . $herecurr);
			}
		}
# check for memory barriers without a comment.
		if ($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\n" . $herecurr);
			}
		}
# check of hardware specific defines
		if ($line =~ m@^.#\s*if.*\b(__i386__|__powerpc64__|__sun__|__s390x__)\b@ && $realfile !~ m@include/asm-@) {
			CHK("architecture specific defines should be avoided\n" .  $herecurr);
		}

# check the location of the inline attribute, that it is between
# storage class and type.
		if ($line =~ /\b$Type\s+$Inline\b/ ||
		    $line =~ /\b$Inline\s+$Storage\b/) {
			ERROR("inline keyword should sit between storage class and type\n" . $herecurr);
		}

# Check for __inline__ and __inline, prefer inline
		if ($line =~ /\b(__inline__|__inline)\b/) {
			WARN("plain inline is preferred over $1\n" . $herecurr);
		}

# check for new externs in .c files.
		if ($line =~ /^.\s*extern\s/ && ($realfile =~ /\.c$/)) {
			WARN("externs should be avoided in .c files\n" .  $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\n" . $herecurr);
			}
		}

# check for pointless casting of kmalloc return
		if ($line =~ /\*\s*\)\s*k[czm]alloc\b/) {
			WARN("unnecessary cast may hide bugs, see http://c-faq.com/malloc/mallocnocast.html\n" . $herecurr);
		}

# check for gcc specific __FUNCTION__
		if ($line =~ /__FUNCTION__/) {
			WARN("__func__ should be used instead of gcc specific __FUNCTION__\n"  . $herecurr);
		}

# check for semaphores used as mutexes
		if ($line =~ /\b(DECLARE_MUTEX|init_MUTEX)\s*\(/) {
			WARN("mutexes are preferred for single holder semaphores\n" . $herecurr);
		}
# check for semaphores used as mutexes
		if ($line =~ /\binit_MUTEX_LOCKED\s*\(/) {
			WARN("consider using a completion\n" . $herecurr);
		}
# recommend strict_strto* over simple_strto*
		if ($line =~ /\bsimple_(strto.*?)\s*\(/) {
			WARN("consider using strict_$1 in preference to simple_$1\n" . $herecurr);
		}

# use of NR_CPUS is usually wrong
# ignore definitions of NR_CPUS and usage to define arrays as likely right
		if ($line =~ /\bNR_CPUS\b/ &&
		    $line !~ /^.#\s*define\s+NR_CPUS\s+/ &&
		    $line !~ /^.\s*$Declare\s.*\[[^\]]*NR_CPUS[^\]]*\]/)
		{
			WARN("usage of NR_CPUS is often wrong - consider using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc\n" . $herecurr);
		}
	}

	# If we have no input at all, then there is nothing to report on
	# so just keep quiet.
	if ($#rawlines == -1) {
		exit(0);
	}

	# In mailback mode only produce a report in the negative, for
	# things that appear to be patches.
	if ($mailback && ($clean == 1 || !$is_patch)) {
		exit(0);
	}