checkpatch.pl

##			     "No blank lines before declarations\n" . $hereprev);
##		}
##

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

# check spacing on square brackets
		if ($line =~ /\[\s/ && $line !~ /\[\s*$/) {
			if (ERROR("SPACING",
				  "space prohibited after that open square bracket '['\n" . $herecurr) &&
			    $fix) {
				$fixed[$linenr - 1] =~
				    s/\[\s+/\[/;
			}
		}
		if ($line =~ /\s\]/) {
			if (ERROR("SPACING",
				  "space prohibited before that close square bracket ']'\n" . $herecurr) &&
			    $fix) {
				$fixed[$linenr - 1] =~
				    s/\s+\]/\]/;
			}
		}

# check spacing on parentheses
		if ($line =~ /\(\s/ && $line !~ /\(\s*(?:\\)?$/ &&
		    $line !~ /for\s*\(\s+;/) {
			if (ERROR("SPACING",
				  "space prohibited after that open parenthesis '('\n" . $herecurr) &&
			    $fix) {
				$fixed[$linenr - 1] =~
				    s/\(\s+/\(/;
			}
		}
		if ($line =~ /(\s+)\)/ && $line !~ /^.\s*\)/ &&
		    $line !~ /for\s*\(.*;\s+\)/ &&
		    $line !~ /:\s+\)/) {
			if (ERROR("SPACING",
				  "space prohibited before that close parenthesis ')'\n" . $herecurr) &&
			    $fix) {
				$fixed[$linenr - 1] =~
				    s/\s+\)/\)/;
			}
		}

#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:/)) {
			if (WARN("INDENTED_LABEL",
				 "labels should not be indented\n" . $herecurr) &&
			    $fix) {
				$fixed[$linenr - 1] =~
				    s/^(.)\s+/$1/;
			}
		}

# Return is not a function.
		if (defined($stat) && $stat =~ /^.\s*return(\s*)(\(.*);/s) {
			my $spacing = $1;
			my $value = $2;

			# Flatten any parentheses
			$value =~ s/\(/ \(/g;
			$value =~ s/\)/\) /g;
			while ($value =~ s/\[[^\[\]]*\]/1/ ||
			       $value !~ /(?:$Ident|-?$Constant)\s*
					     $Compare\s*
					     (?:$Ident|-?$Constant)/x &&
			       $value =~ s/\([^\(\)]*\)/1/) {
			}
#print "value<$value>\n";
			if ($value =~ /^\s*(?:$Ident|-?$Constant)\s*$/) {
				ERROR("RETURN_PARENTHESES",
				      "return is not a function, parentheses are not required\n" . $herecurr);

			} elsif ($spacing !~ /\s+/) {
				ERROR("SPACING",
				      "space required before the open parenthesis '('\n" . $herecurr);
			}
		}
# Return of what appears to be an errno should normally be -'ve
		if ($line =~ /^.\s*return\s*(E[A-Z]*)\s*;/) {
			my $name = $1;
			if ($name ne 'EOF' && $name ne 'ERROR') {
				WARN("USE_NEGATIVE_ERRNO",
				     "return of an errno should typically be -ve (return -$1)\n" . $herecurr);
			}
		}

# Need a space before open parenthesis after if, while etc
		if ($line =~ /\b(if|while|for|switch)\(/) {
			if (ERROR("SPACING",
				  "space required before the open parenthesis '('\n" . $herecurr) &&
			    $fix) {
				$fixed[$linenr - 1] =~
				    s/\b(if|while|for|switch)\(/$1 \(/;
			}
		}

# Check for illegal assignment in if conditional -- and check for trailing
# statements after the conditional.
		if ($line =~ /do\s*(?!{)/) {
			($stat, $cond, $line_nr_next, $remain_next, $off_next) =
				ctx_statement_block($linenr, $realcnt, 0)
					if (!defined $stat);
			my ($stat_next) = ctx_statement_block($line_nr_next,
						$remain_next, $off_next);
			$stat_next =~ s/\n./\n /g;
			##print "stat<$stat> stat_next<$stat_next>\n";

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

				$suppress_whiletrailers{$line_nr_next +
								$offset} = 1;
			}
		}
		if (!defined $suppress_whiletrailers{$linenr} &&
		    $line =~ /\b(?:if|while|for)\s*\(/ && $line !~ /^.\s*#/) {
			my ($s, $c) = ($stat, $cond);

			if ($c =~ /\bif\s*\(.*[^<>!=]=[^=].*/s) {
				ERROR("ASSIGN_IN_IF",
				      "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) && $s !~ /^\s*{?\s*\\*\s*$/ &&
			    $c !~ /}\s*while\s*/)
			{
				# Find out how long the conditional actually is.
				my @newlines = ($c =~ /\n/gs);
				my $cond_lines = 1 + $#newlines;
				my $stat_real = '';

				$stat_real = raw_line($linenr, $cond_lines)
							. "\n" if ($cond_lines);
				if (defined($stat_real) && $cond_lines > 1) {
					$stat_real = "[...]\n$stat_real";
				}

				ERROR("TRAILING_STATEMENTS",
				      "trailing statements should be on next line\n" . $herecurr . $stat_real);
			}
		}

# Check for bitwise tests written as boolean
		if ($line =~ /
			(?:
				(?:\[|\(|\&\&|\|\|)
				\s*0[xX][0-9]+\s*
				(?:\&\&|\|\|)
			|
				(?:\&\&|\|\|)
				\s*0[xX][0-9]+\s*
				(?:\&\&|\|\||\)|\])
			)/x)
		{
			WARN("HEXADECIMAL_BOOLEAN_TEST",
			     "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",
				      "trailing statements should be on next line\n" . $herecurr);
			}
		}
# if should not continue a brace
		if ($line =~ /}\s*if\b/) {
			ERROR("TRAILING_STATEMENTS",
			      "trailing statements should be on next line\n" .
				$herecurr);
		}
# case and default should not have general statements after them
		if ($line =~ /^.\s*(?:case\s*.*|default\s*):/g &&
		    $line !~ /\G(?:
			(?:\s*$;*)(?:\s*{)?(?:\s*$;*)(?:\s*\\)?\s*$|
			\s*return\s+
		    )/xg)
		{
			ERROR("TRAILING_STATEMENTS",
			      "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_AFTER_BRACE",
			      "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_AFTER_BRACE",
				      "while should follow close brace '}'\n" . $hereprev);
			}
		}

#Specific variable tests
		while ($line =~ m{($Constant|$Lval)}g) {
			my $var = $1;

#gcc binary extension
			if ($var =~ /^$Binary$/) {
				WARN("GCC_BINARY_CONSTANT",
				     "Avoid gcc v4.3+ binary constant extension: <$var>\n" . $herecurr);
			}

#CamelCase
			if ($var !~ /^$Constant$/ &&
			    $var =~ /[A-Z][a-z]|[a-z][A-Z]/ &&
#Ignore Page<foo> variants
			    $var !~ /^(?:Clear|Set|TestClear|TestSet|)Page[A-Z]/ &&
#Ignore SI style variants like nS, mV and dB (ie: max_uV, regulator_min_uA_show)
			    $var !~ /^(?:[a-z_]*?)_?[a-z][A-Z](?:_[a-z_]+)?$/) {
				seed_camelcase_includes() if ($check);
				if (!defined $camelcase{$var}) {
					$camelcase{$var} = 1;
					CHK("CAMELCASE",
					    "Avoid CamelCase: <$var>\n" . $herecurr);
				}
			}
		}

#no spaces allowed after \ in define
		if ($line=~/\#\s*define.*\\\s$/) {
			WARN("WHITESPACE_AFTER_LINE_CONTINUATION",
			     "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*\#\s*include\s*\<asm\/(.*)\.h\>}) {
			my $file = "$1.h";
			my $checkfile = "include/linux/$file";
			if (-f "$root/$checkfile" &&
			    $realfile ne $checkfile &&
			    $1 !~ /$allowed_asm_includes/)
			{
				if ($realfile =~ m{^arch/}) {
					CHK("ARCH_INCLUDE_LINUX",
					    "Consider using #include <linux/$file> instead of <asm/$file>\n" . $herecurr);
				} else {
					WARN("INCLUDE_LINUX",
					     "Use #include <linux/$file> instead of <asm/$file>\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 ($realfile !~ m@/vmlinux.lds.h$@ &&
		    $line =~ /^.\s*\#\s*define\s*$Ident(\()?/) {
			my $ln = $linenr;
			my $cnt = $realcnt;
			my ($off, $dstat, $dcond, $rest);
			my $ctx = '';
			($dstat, $dcond, $ln, $cnt, $off) =
				ctx_statement_block($linenr, $realcnt, 0);
			$ctx = $dstat;
			#print "dstat<$dstat> dcond<$dcond> cnt<$cnt> off<$off>\n";
			#print "LINE<$lines[$ln-1]> len<" . length($lines[$ln-1]) . "\n";

			$dstat =~ s/^.\s*\#\s*define\s+$Ident(?:\([^\)]*\))?\s*//;
			$dstat =~ s/$;//g;
			$dstat =~ s/\\\n.//g;
			$dstat =~ s/^\s*//s;
			$dstat =~ s/\s*$//s;

			# Flatten any parentheses and braces
			while ($dstat =~ s/\([^\(\)]*\)/1/ ||
			       $dstat =~ s/\{[^\{\}]*\}/1/ ||
			       $dstat =~ s/\[[^\[\]]*\]/1/)
			{
			}

			# Flatten any obvious string concatentation.
			while ($dstat =~ s/("X*")\s*$Ident/$1/ ||
			       $dstat =~ s/$Ident\s*("X*")/$1/)
			{
			}

			my $exceptions = qr{
				$Declare|
				module_param_named|
				MODULE_PARM_DESC|
				DECLARE_PER_CPU|
				DEFINE_PER_CPU|
				__typeof__\(|
				union|
				struct|
				\.$Ident\s*=\s*|
				^\"|\"$
			}x;
			#print "REST<$rest> dstat<$dstat> ctx<$ctx>\n";
			if ($dstat ne '' &&
			    $dstat !~ /^(?:$Ident|-?$Constant),$/ &&			# 10, // foo(),
			    $dstat !~ /^(?:$Ident|-?$Constant);$/ &&			# foo();
			    $dstat !~ /^[!~-]?(?:$Lval|$Constant)$/ &&		# 10 // foo() // !foo // ~foo // -foo // foo->bar // foo.bar->baz
			    $dstat !~ /^'X'$/ &&					# character constants
			    $dstat !~ /$exceptions/ &&
			    $dstat !~ /^\.$Ident\s*=/ &&				# .foo =
			    $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ &&		# stringification #foo
			    $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ &&	# do {...} while (...); // do {...} while (...)
			    $dstat !~ /^for\s*$Constant$/ &&				# for (...)
			    $dstat !~ /^for\s*$Constant\s+(?:$Ident|-?$Constant)$/ &&	# for (...) bar()
			    $dstat !~ /^do\s*{/ &&					# do {...
			    $dstat !~ /^\({/)						# ({...
			{
				$ctx =~ s/\n*$//;
				my $herectx = $here . "\n";
				my $cnt = statement_rawlines($ctx);

				for (my $n = 0; $n < $cnt; $n++) {
					$herectx .= raw_line($linenr, $n) . "\n";
				}

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

# check for line continuations outside of #defines, preprocessor #, and asm

		} else {
			if ($prevline !~ /^..*\\$/ &&
			    $line !~ /^\+\s*\#.*\\$/ &&		# preprocessor
			    $line !~ /^\+.*\b(__asm__|asm)\b.*\\$/ &&	# asm
			    $line =~ /^\+.*\\$/) {
				WARN("LINE_CONTINUATIONS",
				     "Avoid unnecessary line continuations\n" . $herecurr);
			}
		}

# do {} while (0) macro tests:
# single-statement macros do not need to be enclosed in do while (0) loop,
# macro should not end with a semicolon
		if ($^V && $^V ge 5.10.0 &&
		    $realfile !~ m@/vmlinux.lds.h$@ &&
		    $line =~ /^.\s*\#\s*define\s+$Ident(\()?/) {
			my $ln = $linenr;
			my $cnt = $realcnt;
			my ($off, $dstat, $dcond, $rest);
			my $ctx = '';
			($dstat, $dcond, $ln, $cnt, $off) =
				ctx_statement_block($linenr, $realcnt, 0);
			$ctx = $dstat;

			$dstat =~ s/\\\n.//g;

			if ($dstat =~ /^\+\s*#\s*define\s+$Ident\s*${balanced_parens}\s*do\s*{(.*)\s*}\s*while\s*\(\s*0\s*\)\s*([;\s]*)\s*$/) {
				my $stmts = $2;
				my $semis = $3;

				$ctx =~ s/\n*$//;
				my $cnt = statement_rawlines($ctx);
				my $herectx = $here . "\n";

				for (my $n = 0; $n < $cnt; $n++) {
					$herectx .= raw_line($linenr, $n) . "\n";
				}

				if (($stmts =~ tr/;/;/) == 1 &&
				    $stmts !~ /^\s*(if|while|for|switch)\b/) {
					WARN("SINGLE_STATEMENT_DO_WHILE_MACRO",
					     "Single statement macros should not use a do {} while (0) loop\n" . "$herectx");
				}
				if (defined $semis && $semis ne "") {
					WARN("DO_WHILE_MACRO_WITH_TRAILING_SEMICOLON",
					     "do {} while (0) macros should not be semicolon terminated\n" . "$herectx");
				}
			}
		}

# make sure symbols are always wrapped with VMLINUX_SYMBOL() ...
# all assignments may have only one of the following with an assignment:
#	.
#	ALIGN(...)
#	VMLINUX_SYMBOL(...)
		if ($realfile eq 'vmlinux.lds.h' && $line =~ /(?:(?:^|\s)$Ident\s*=|=\s*$Ident(?:\s|$))/) {
			WARN("MISSING_VMLINUX_SYMBOL",
			     "vmlinux.lds.h needs VMLINUX_SYMBOL() around C-visible symbols\n" . $herecurr);
		}

# 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 = ();
				my $allow = 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;

					$allowed[$allow] = 0;
					#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<$allowed[$allow]>\n";
					if (statement_lines($cond) > 1) {
						#print "APW: ALLOWED: cond<$cond>\n";
						$allowed[$allow] = 1;
					}
					if ($block =~/\b(?:if|for|while)\b/) {
						#print "APW: ALLOWED: block<$block>\n";
						$allowed[$allow] = 1;
					}
					if (statement_block_size($block) > 1) {
						#print "APW: ALLOWED: lines block<$block>\n";
						$allowed[$allow] = 1;
					}
					$allow++;
				}
				if ($seen) {
					my $sum_allowed = 0;
					foreach (@allowed) {
						$sum_allowed += $_;
					}
					if ($sum_allowed == 0) {
						WARN("BRACES",
						     "braces {} are not necessary for any arm of this statement\n" . $herectx);
					} elsif ($sum_allowed != $allow &&
						 $seen != $allow) {
						CHK("BRACES",
						    "braces {} should be used on all arms 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 $cnt = statement_rawlines($block);

				for (my $n = 0; $n < $cnt; $n++) {
					$herectx .= raw_line($linenr, $n) . "\n";
				}

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

# check for unnecessary blank lines around braces
		if (($line =~ /^.\s*}\s*$/ && $prevrawline =~ /^.\s*$/)) {
			CHK("BRACES",
			    "Blank lines aren't necessary before a close brace '}'\n" . $hereprev);
		}
		if (($rawline =~ /^.\s*$/ && $prevline =~ /^..*{\s*$/)) {
			CHK("BRACES",
			    "Blank lines aren't necessary after an open brace '{'\n" . $hereprev);
		}

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

# warn about #if 0
		if ($line =~ /^.\s*\#\s*if\s+0\b/) {
			CHK("REDUNDANT_CODE",
			    "if this code is redundant consider removing it\n" .
				$herecurr);
		}

# check for needless "if (<foo>) fn(<foo>)" uses
		if ($prevline =~ /\bif\s*\(\s*($Lval)\s*\)/) {
			my $expr = '\s*\(\s*' . quotemeta($1) . '\s*\)\s*;';
			if ($line =~ /\b(kfree|usb_free_urb|debugfs_remove(?:_recursive)?)$expr/) {
				WARN('NEEDLESS_IF',
				     "$1(NULL) is safe this check is probably not required\n" . $hereprev);
			}
		}

# prefer usleep_range over udelay
		if ($line =~ /\budelay\s*\(\s*(\d+)\s*\)/) {
			# ignore udelay's < 10, however
			if (! ($1 < 10) ) {
				CHK("USLEEP_RANGE",
				    "usleep_range is preferred over udelay; see Documentation/timers/timers-howto.txt\n" . $line);
			}
		}

# warn about unexpectedly long msleep's
		if ($line =~ /\bmsleep\s*\((\d+)\);/) {
			if ($1 < 20) {
				WARN("MSLEEP",
				     "msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt\n" . $line);
			}
		}

# check for comparisons of jiffies
		if ($line =~ /\bjiffies\s*$Compare|$Compare\s*jiffies\b/) {
			WARN("JIFFIES_COMPARISON",
			     "Comparing jiffies is almost always wrong; prefer time_after, time_before and friends\n" . $herecurr);
		}

# check for comparisons of get_jiffies_64()
		if ($line =~ /\bget_jiffies_64\s*\(\s*\)\s*$Compare|$Compare\s*get_jiffies_64\s*\(\s*\)/) {
			WARN("JIFFIES_COMPARISON",
			     "Comparing get_jiffies_64() is almost always wrong; prefer time_after64, time_before64 and friends\n" . $herecurr);
		}

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

# warn about spacing in #ifdefs
		if ($line =~ /^.\s*\#\s*(ifdef|ifndef|elif)\s\s+/) {
			if (ERROR("SPACING",
				  "exactly one space required after that #$1\n" . $herecurr) &&
			    $fix) {
				$fixed[$linenr - 1] =~
				    s/^(.\s*\#\s*(ifdef|ifndef|elif))\s{2,}/$1 /;
			}

		}

# check for spinlock_t definitions without a comment.
		if ($line =~ /^.\s*(struct\s+mutex|spinlock_t)\s+\S+;/ ||
		    $line =~ /^.\s*(DEFINE_MUTEX)\s*\(/) {
			my $which = $1;
			if (!ctx_has_comment($first_line, $linenr)) {
				CHK("UNCOMMENTED_DEFINITION",
				    "$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",
				    "memory barrier without comment\n" . $herecurr);
			}
		}
# check of hardware specific defines
		if ($line =~ m@^.\s*\#\s*if.*\b(__i386__|__powerpc64__|__sun__|__s390x__)\b@ && $realfile !~ m@include/asm-@) {
			CHK("ARCH_DEFINES",
			    "architecture specific defines should be avoided\n" .  $herecurr);
		}

# Check that the storage class is at the beginning of a declaration
		if ($line =~ /\b$Storage\b/ && $line !~ /^.\s*$Storage\b/) {
			WARN("STORAGE_CLASS",
			     "storage class should be at the beginning of the declaration\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_LOCATION",
			      "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("INLINE",
			     "plain inline is preferred over $1\n" . $herecurr);
		}

# Check for __attribute__ packed, prefer __packed
		if ($line =~ /\b__attribute__\s*\(\s*\(.*\bpacked\b/) {
			WARN("PREFER_PACKED",
			     "__packed is preferred over __attribute__((packed))\n" . $herecurr);
		}

# Check for __attribute__ aligned, prefer __aligned
		if ($line =~ /\b__attribute__\s*\(\s*\(.*aligned/) {
			WARN("PREFER_ALIGNED",
			     "__aligned(size) is preferred over __attribute__((aligned(size)))\n" . $herecurr);
		}

# Check for __attribute__ format(printf, prefer __printf
		if ($line =~ /\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf/) {
			WARN("PREFER_PRINTF",
			     "__printf(string-index, first-to-check) is preferred over __attribute__((format(printf, string-index, first-to-check)))\n" . $herecurr);
		}

# Check for __attribute__ format(scanf, prefer __scanf
		if ($line =~ /\b__attribute__\s*\(\s*\(\s*format\s*\(\s*scanf\b/) {
			WARN("PREFER_SCANF",
			     "__scanf(string-index, first-to-check) is preferred over __attribute__((format(scanf, string-index, first-to-check)))\n" . $herecurr);
		}

# check for sizeof(&)
		if ($line =~ /\bsizeof\s*\(\s*\&/) {
			WARN("SIZEOF_ADDRESS",
			     "sizeof(& should be avoided\n" . $herecurr);
		}

# check for sizeof without parenthesis
		if ($line =~ /\bsizeof\s+((?:\*\s*|)$Lval|$Type(?:\s+$Lval|))/) {
			WARN("SIZEOF_PARENTHESIS",
			     "sizeof $1 should be sizeof($1)\n" . $herecurr);
		}

# check for line continuations in quoted strings with odd counts of "
		if ($rawline =~ /\\$/ && $rawline =~ tr/"/"/ % 2) {
			WARN("LINE_CONTINUATIONS",
			     "Avoid line continuations in quoted strings\n" . $herecurr);
		}

# check for struct spinlock declarations
		if ($line =~ /^.\s*\bstruct\s+spinlock\s+\w+\s*;/) {
			WARN("USE_SPINLOCK_T",
			     "struct spinlock should be spinlock_t\n" . $herecurr);
		}

# check for seq_printf uses that could be seq_puts
		if ($line =~ /\bseq_printf\s*\(/) {
			my $fmt = get_quoted_string($line, $rawline);
			if ($fmt !~ /[^\\]\%/) {
				WARN("PREFER_SEQ_PUTS",
				     "Prefer seq_puts to seq_printf\n" . $herecurr);
			}
		}

# Check for misused memsets
		if ($^V && $^V ge 5.10.0 &&
		    defined $stat &&
		    $stat =~ /^\+(?:.*?)\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*$FuncArg\s*\)/s) {

			my $ms_addr = $2;
			my $ms_val = $7;
			my $ms_size = $12;

			if ($ms_size =~ /^(0x|)0$/i) {
				ERROR("MEMSET",
				      "memset to 0's uses 0 as the 2nd argument, not the 3rd\n" . "$here\n$stat\n");
			} elsif ($ms_size =~ /^(0x|)1$/i) {
				WARN("MEMSET",
				     "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$stat\n");
			}
		}

# typecasts on min/max could be min_t/max_t
		if ($^V && $^V ge 5.10.0 &&
		    defined $stat &&
		    $stat =~ /^\+(?:.*?)\b(min|max)\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\)/) {
			if (defined $2 || defined $7) {
				my $call = $1;
				my $cast1 = deparenthesize($2);
				my $arg1 = $3;
				my $cast2 = deparenthesize($7);
				my $arg2 = $8;
				my $cast;

				if ($cast1 ne "" && $cast2 ne "" && $cast1 ne $cast2) {
					$cast = "$cast1 or $cast2";
				} elsif ($cast1 ne "") {
					$cast = $cast1;
				} else {
					$cast = $cast2;
				}
				WARN("MINMAX",
				     "$call() should probably be ${call}_t($cast, $arg1, $arg2)\n" . "$here\n$stat\n");
			}
		}

# check usleep_range arguments
		if ($^V && $^V ge 5.10.0 &&
		    defined $stat &&
		    $stat =~ /^\+(?:.*?)\busleep_range\s*\(\s*($FuncArg)\s*,\s*($FuncArg)\s*\)/) {
			my $min = $1;
			my $max = $7;
			if ($min eq $max) {
				WARN("USLEEP_RANGE",
				     "usleep_range should not use min == max args; see Documentation/timers/timers-howto.txt\n" . "$here\n$stat\n");
			} elsif ($min =~ /^\d+$/ && $max =~ /^\d+$/ &&
				 $min > $max) {
				WARN("USLEEP_RANGE",
				     "usleep_range args reversed, use min then max; see Documentation/timers/timers-howto.txt\n" . "$here\n$stat\n");
			}
		}

# check for new externs in .c files.
		if ($realfile =~ /\.c$/ && defined $stat &&
		    $stat =~ /^.\s*(?:extern\s+)?$Type\s+($Ident)(\s*)\(/s)
		{
			my $function_name = $1;
			my $paren_space = $2;

			my $s = $stat;
			if (defined $cond) {
				substr($s, 0, length($cond), '');
			}
			if ($s =~ /^\s*;/ &&
			    $function_name ne 'uninitialized_var')
			{
				WARN("AVOID_EXTERNS",
				     "externs should be avoided in .c files\n" .  $herecurr);
			}

			if ($paren_space =~ /\n/) {
				WARN("FUNCTION_ARGUMENTS",
				     "arguments for function declarations should follow identifier\n" . $herecurr);
			}

		} elsif ($realfile =~ /\.c$/ && defined $stat &&
		    $stat =~ /^.\s*extern\s+/)
		{
			WARN("AVOID_EXTERNS",
			     "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("UNDOCUMENTED_SETUP",
				    "__setup appears un-documented -- check Documentation/kernel-parameters.txt\n" . $herecurr);
			}
		}

# check for pointless casting of kmalloc return
		if ($line =~ /\*\s*\)\s*[kv][czm]alloc(_node){0,1}\b/) {
			WARN("UNNECESSARY_CASTS",
			     "unnecessary cast may hide bugs, see http://c-faq.com/malloc/mallocnocast.html\n" . $herecurr);
		}

# alloc style
# p = alloc(sizeof(struct foo), ...) should be p = alloc(sizeof(*p), ...)
		if ($^V && $^V ge 5.10.0 &&
		    $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*([kv][mz]alloc(?:_node)?)\s*\(\s*(sizeof\s*\(\s*struct\s+$Lval\s*\))/) {
			CHK("ALLOC_SIZEOF_STRUCT",
			    "Prefer $3(sizeof(*$1)...) over $3($4...)\n" . $herecurr);
		}

# check for krealloc arg reuse
		if ($^V && $^V ge 5.10.0 &&
		    $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*krealloc\s*\(\s*\1\s*,/) {
			WARN("KREALLOC_ARG_REUSE",
			     "Reusing the krealloc arg is almost always a bug\n" . $herecurr);
		}

# check for alloc argument mismatch
		if ($line =~ /\b(kcalloc|kmalloc_array)\s*\(\s*sizeof\b/) {
			WARN("ALLOC_ARRAY_ARGS",
			     "$1 uses number as first arg, sizeof is generally wrong\n" . $herecurr);
		}

# check for multiple semicolons
		if ($line =~ /;\s*;\s*$/) {
			WARN("ONE_SEMICOLON",
			     "Statements terminations use 1 semicolon\n" . $herecurr);
		}

# check for switch/default statements without a break;
		if ($^V && $^V ge 5.10.0 &&
		    defined $stat &&
		    $stat =~ /^\+[$;\s]*(?:case[$;\s]+\w+[$;\s]*:[$;\s]*|)*[$;\s]*\bdefault[$;\s]*:[$;\s]*;/g) {
			my $ctx = '';
			my $herectx = $here . "\n";
			my $cnt = statement_rawlines($stat);
			for (my $n = 0; $n < $cnt; $n++) {
				$herectx .= raw_line($linenr, $n) . "\n";
			}
			WARN("DEFAULT_NO_BREAK",
			     "switch default: should use break\n" . $herectx);
		}

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

# check for use of yield()
		if ($line =~ /\byield\s*\(\s*\)/) {
			WARN("YIELD",
			     "Using yield() is generally wrong. See yield() kernel-doc (sched/core.c)\n"  . $herecurr);
		}

# check for comparisons against true and false
		if ($line =~ /\+\s*(.*?)\b(true|false|$Lval)\s*(==|\!=)\s*(true|false|$Lval)\b(.*)$/i) {
			my $lead = $1;
			my $arg = $2;
			my $test = $3;
			my $otype = $4;
			my $trail = $5;
			my $op = "!";

			($arg, $otype) = ($otype, $arg) if ($arg =~ /^(?:true|false)$/i);

			my $type = lc($otype);
			if ($type =~ /^(?:true|false)$/) {
				if (("$test" eq "==" && "$type" eq "true") ||
				    ("$test" eq "!=" && "$type" eq "false")) {
					$op = "";
				}

				CHK("BOOL_COMPARISON",
				    "Using comparison to $otype is error prone\n" . $herecurr);

## maybe suggesting a correct construct would better
##				    "Using comparison to $otype is error prone.  Perhaps use '${lead}${op}${arg}${trail}'\n" . $herecurr);

			}
		}

# check for semaphores initialized locked
		if ($line =~ /^.\s*sema_init.+,\W?0\W?\)/) {
			WARN("CONSIDER_COMPLETION",
			     "consider using a completion\n" . $herecurr);
		}

# recommend kstrto* over simple_strto* and strict_strto*
		if ($line =~ /\b((simple|strict)_(strto(l|ll|ul|ull)))\s*\(/) {
			WARN("CONSIDER_KSTRTO",
			     "$1 is obsolete, use k$3 instead\n" . $herecurr);
		}

# check for __initcall(), use device_initcall() explicitly please
		if ($line =~ /^.\s*__initcall\s*\(/) {
			WARN("USE_DEVICE_INITCALL",
			     "please use device_initcall() instead of __initcall()\n" . $herecurr);
		}

# check for various ops structs, ensure they are const.
		my $struct_ops = qr{acpi_dock_ops|
				address_space_operations|
				backlight_ops|
				block_device_operations|
				dentry_operations|
				dev_pm_ops|
				dma_map_ops|
				extent_io_ops|
				file_lock_operations|
				file_operations|
				hv_ops|
				ide_dma_ops|
				intel_dvo_dev_ops|
				item_operations|
				iwl_ops|
				kgdb_arch|
				kgdb_io|
				kset_uevent_ops|
				lock_manager_operations|
				microcode_ops|
				mtrr_ops|
				neigh_ops|
				nlmsvc_binding|
				pci_raw_ops|
				pipe_buf_operations|
				platform_hibernation_ops|
				platform_suspend_ops|
				proto_ops|
				rpc_pipe_ops|
				seq_operations|
				snd_ac97_build_ops|
				soc_pcmcia_socket_ops|
				stacktrace_ops|
				sysfs_ops|
				tty_operations|
				usb_mon_operations|
				wd_ops}x;
		if ($line !~ /\bconst\b/ &&
		    $line =~ /\bstruct\s+($struct_ops)\b/) {
			WARN("CONST_STRUCT",
			     "struct $1 should normally be const\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*\s*#\s*if\b.*\bNR_CPUS\b/ &&
		    $line !~ /^.\s*\s*#\s*define\b.*\bNR_CPUS\b/ &&
		    $line !~ /^.\s*$Declare\s.*\[[^\]]*NR_CPUS[^\]]*\]/ &&
		    $line !~ /\[[^\]]*\.\.\.[^\]]*NR_CPUS[^\]]*\]/ &&
		    $line !~ /\[[^\]]*NR_CPUS[^\]]*\.\.\.[^\]]*\]/)
		{
			WARN("NR_CPUS",
			     "usage of NR_CPUS is often wrong - consider using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc\n" . $herecurr);
		}

# check for %L{u,d,i} in strings
		my $string;
		while ($line =~ /(?:^|")([X\t]*)(?:"|$)/g) {
			$string = substr($rawline, $-[1], $+[1] - $-[1]);
			$string =~ s/%%/__/g;
			if ($string =~ /(?<!%)%L[udi]/) {
				WARN("PRINTF_L",
				     "\%Ld/%Lu are not-standard C, use %lld/%llu\n" . $herecurr);
				last;
			}
		}

# whine mightly about in_atomic
		if ($line =~ /\bin_atomic\s*\(/) {
			if ($realfile =~ m@^drivers/@) {
				ERROR("IN_ATOMIC",
				      "do not use in_atomic in drivers\n" . $herecurr);
			} elsif ($realfile !~ m@^kernel/@) {
				WARN("IN_ATOMIC",
				     "use of in_atomic() is incorrect outside core kernel code\n" . $herecurr);
			}
		}

# check for lockdep_set_novalidate_class
		if ($line =~ /^.\s*lockdep_set_novalidate_class\s*\(/ ||
		    $line =~ /__lockdep_no_validate__\s*\)/ ) {
			if ($realfile !~ m@^kernel/lockdep@ &&
			    $realfile !~ m@^include/linux/lockdep@ &&