xref: /linux/scripts/checkpatch.pl (revision 8b4a40809e5330c9da5d20107d693d92d73b31dc)
1#!/usr/bin/perl -w
2# (c) 2001, Dave Jones. <davej@codemonkey.org.uk> (the file handling bit)
3# (c) 2005, Joel Schopp <jschopp@austin.ibm.com> (the ugly bit)
4# (c) 2007, Andy Whitcroft <apw@uk.ibm.com> (new conditions, test suite, etc)
5# Licensed under the terms of the GNU GPL License version 2
6
7use strict;
8
9my $P = $0;
10$P =~ s@.*/@@g;
11
12my $V = '0.07';
13
14use Getopt::Long qw(:config no_auto_abbrev);
15
16my $quiet = 0;
17my $tree = 1;
18my $chk_signoff = 1;
19my $chk_patch = 1;
20my $tst_type = 0;
21GetOptions(
22	'q|quiet'	=> \$quiet,
23	'tree!'		=> \$tree,
24	'signoff!'	=> \$chk_signoff,
25	'patch!'	=> \$chk_patch,
26	'test-type!'	=> \$tst_type,
27) or exit;
28
29my $exit = 0;
30
31if ($#ARGV < 0) {
32	print "usage: $P [options] patchfile\n";
33	print "version: $V\n";
34	print "options: -q           => quiet\n";
35	print "         --no-tree    => run without a kernel tree\n";
36	exit(1);
37}
38
39if ($tree && !top_of_kernel_tree()) {
40	print "Must be run from the top-level dir. of a kernel tree\n";
41	exit(2);
42}
43
44my @dep_includes = ();
45my @dep_functions = ();
46my $removal = 'Documentation/feature-removal-schedule.txt';
47if ($tree && -f $removal) {
48	open(REMOVE, "<$removal") || die "$P: $removal: open failed - $!\n";
49	while (<REMOVE>) {
50		if (/^Files:\s+(.*\S)/) {
51			for my $file (split(/[, ]+/, $1)) {
52				if ($file =~ m@include/(.*)@) {
53					push(@dep_includes, $1);
54				}
55			}
56
57		} elsif (/^Funcs:\s+(.*\S)/) {
58			for my $func (split(/[, ]+/, $1)) {
59				push(@dep_functions, $func);
60			}
61		}
62	}
63}
64
65my @rawlines = ();
66while (<>) {
67	chomp;
68	push(@rawlines, $_);
69	if (eof(ARGV)) {
70		if (!process($ARGV, @rawlines)) {
71			$exit = 1;
72		}
73		@rawlines = ();
74	}
75}
76
77exit($exit);
78
79sub top_of_kernel_tree {
80	if ((-f "COPYING") && (-f "CREDITS") && (-f "Kbuild") &&
81	    (-f "MAINTAINERS") && (-f "Makefile") && (-f "README") &&
82	    (-d "Documentation") && (-d "arch") && (-d "include") &&
83	    (-d "drivers") && (-d "fs") && (-d "init") && (-d "ipc") &&
84	    (-d "kernel") && (-d "lib") && (-d "scripts")) {
85		return 1;
86	}
87	return 0;
88}
89
90sub expand_tabs {
91	my ($str) = @_;
92
93	my $res = '';
94	my $n = 0;
95	for my $c (split(//, $str)) {
96		if ($c eq "\t") {
97			$res .= ' ';
98			$n++;
99			for (; ($n % 8) != 0; $n++) {
100				$res .= ' ';
101			}
102			next;
103		}
104		$res .= $c;
105		$n++;
106	}
107
108	return $res;
109}
110
111sub line_stats {
112	my ($line) = @_;
113
114	# Drop the diff line leader and expand tabs
115	$line =~ s/^.//;
116	$line = expand_tabs($line);
117
118	# Pick the indent from the front of the line.
119	my ($white) = ($line =~ /^(\s*)/);
120
121	return (length($line), length($white));
122}
123
124sub sanitise_line {
125	my ($line) = @_;
126
127	my $res = '';
128	my $l = '';
129
130	my $quote = '';
131
132	foreach my $c (split(//, $line)) {
133		if ($l ne "\\" && ($c eq "'" || $c eq '"')) {
134			if ($quote eq '') {
135				$quote = $c;
136				$res .= $c;
137				$l = $c;
138				next;
139			} elsif ($quote eq $c) {
140				$quote = '';
141			}
142		}
143		if ($quote && $c ne "\t") {
144			$res .= "X";
145		} else {
146			$res .= $c;
147		}
148
149		$l = $c;
150	}
151
152	return $res;
153}
154
155sub ctx_block_get {
156	my ($linenr, $remain, $outer, $open, $close) = @_;
157	my $line;
158	my $start = $linenr - 1;
159	my $blk = '';
160	my @o;
161	my @c;
162	my @res = ();
163
164	for ($line = $start; $remain > 0; $line++) {
165		next if ($rawlines[$line] =~ /^-/);
166		$remain--;
167
168		$blk .= $rawlines[$line];
169
170		@o = ($blk =~ /$open/g);
171		@c = ($blk =~ /$close/g);
172
173		if (!$outer || (scalar(@o) - scalar(@c)) == 1) {
174			push(@res, $rawlines[$line]);
175		}
176
177		last if (scalar(@o) == scalar(@c));
178	}
179
180	return @res;
181}
182sub ctx_block_outer {
183	my ($linenr, $remain) = @_;
184
185	return ctx_block_get($linenr, $remain, 1, '\{', '\}');
186}
187sub ctx_block {
188	my ($linenr, $remain) = @_;
189
190	return ctx_block_get($linenr, $remain, 0, '\{', '\}');
191}
192sub ctx_statement {
193	my ($linenr, $remain) = @_;
194
195	return ctx_block_get($linenr, $remain, 0, '\(', '\)');
196}
197
198sub ctx_locate_comment {
199	my ($first_line, $end_line) = @_;
200
201	# Catch a comment on the end of the line itself.
202	my ($current_comment) = ($rawlines[$end_line - 1] =~ m@.*(/\*.*\*/)\s*$@);
203	return $current_comment if (defined $current_comment);
204
205	# Look through the context and try and figure out if there is a
206	# comment.
207	my $in_comment = 0;
208	$current_comment = '';
209	for (my $linenr = $first_line; $linenr < $end_line; $linenr++) {
210		my $line = $rawlines[$linenr - 1];
211		#warn "           $line\n";
212		if ($linenr == $first_line and $line =~ m@^.\s*\*@) {
213			$in_comment = 1;
214		}
215		if ($line =~ m@/\*@) {
216			$in_comment = 1;
217		}
218		if (!$in_comment && $current_comment ne '') {
219			$current_comment = '';
220		}
221		$current_comment .= $line . "\n" if ($in_comment);
222		if ($line =~ m@\*/@) {
223			$in_comment = 0;
224		}
225	}
226
227	chomp($current_comment);
228	return($current_comment);
229}
230sub ctx_has_comment {
231	my ($first_line, $end_line) = @_;
232	my $cmt = ctx_locate_comment($first_line, $end_line);
233
234	##print "LINE: $rawlines[$end_line - 1 ]\n";
235	##print "CMMT: $cmt\n";
236
237	return ($cmt ne '');
238}
239
240sub cat_vet {
241	my ($vet) = @_;
242
243	$vet =~ s/\t/^I/;
244	$vet =~ s/$/\$/;
245
246	return $vet;
247}
248
249sub ERROR {
250	print "ERROR: $_[0]\n";
251	our $clean = 0;
252}
253sub WARN {
254	print "WARNING: $_[0]\n";
255	our $clean = 0;
256}
257sub CHK {
258	print "CHECK: $_[0]\n";
259	our $clean = 0;
260}
261
262sub process {
263	my $filename = shift;
264	my @lines = @_;
265
266	my $linenr=0;
267	my $prevline="";
268	my $stashline="";
269
270	my $length;
271	my $indent;
272	my $previndent=0;
273	my $stashindent=0;
274
275	our $clean = 1;
276	my $signoff = 0;
277	my $is_patch = 0;
278
279	# Trace the real file/line as we go.
280	my $realfile = '';
281	my $realline = 0;
282	my $realcnt = 0;
283	my $here = '';
284	my $in_comment = 0;
285	my $first_line = 0;
286
287	my $Ident	= qr{[A-Za-z\d_]+};
288	my $Storage	= qr{extern|static};
289	my $Sparse	= qr{__user|__kernel|__force|__iomem};
290	my $NonptrType	= qr{
291				\b
292				(?:const\s+)?
293				(?:unsigned\s+)?
294				(?:
295					void|
296					char|
297					short|
298					int|
299					long|
300					unsigned|
301					float|
302					double|
303					long\s+int|
304					long\s+long|
305					long\s+long\s+int|
306					u8|u16|u32|u64|
307					s8|s16|s32|s64|
308					struct\s+$Ident|
309					union\s+$Ident|
310					enum\s+$Ident|
311					${Ident}_t
312				)
313				(?:\s+$Sparse)*
314				\b
315			  }x;
316	my $Type	= qr{
317				\b$NonptrType\b
318				(?:\s*\*+\s*const|\s*\*+)?
319			  }x;
320	my $Declare	= qr{(?:$Storage\s+)?$Type};
321	my $Attribute	= qr{__read_mostly|__init|__initdata};
322
323	# Pre-scan the patch looking for any __setup documentation.
324	my @setup_docs = ();
325	my $setup_docs = 0;
326	foreach my $line (@lines) {
327		if ($line=~/^\+\+\+\s+(\S+)/) {
328			$setup_docs = 0;
329			if ($1 =~ m@Documentation/kernel-parameters.txt$@) {
330				$setup_docs = 1;
331			}
332			next;
333		}
334
335		if ($setup_docs && $line =~ /^\+/) {
336			push(@setup_docs, $line);
337		}
338	}
339
340	foreach my $line (@lines) {
341		$linenr++;
342
343		my $rawline = $line;
344
345#extract the filename as it passes
346		if ($line=~/^\+\+\+\s+(\S+)/) {
347			$realfile=$1;
348			$realfile =~ s@^[^/]*/@@;
349			$in_comment = 0;
350			next;
351		}
352#extract the line range in the file after the patch is applied
353		if ($line=~/^\@\@ -\d+,\d+ \+(\d+)(,(\d+))? \@\@/) {
354			$is_patch = 1;
355			$first_line = $linenr + 1;
356			$in_comment = 0;
357			$realline=$1-1;
358			if (defined $2) {
359				$realcnt=$3+1;
360			} else {
361				$realcnt=1+1;
362			}
363			next;
364		}
365
366# track the line number as we move through the hunk, note that
367# new versions of GNU diff omit the leading space on completely
368# blank context lines so we need to count that too.
369		if ($line =~ /^( |\+|$)/) {
370			$realline++;
371			$realcnt-- if ($realcnt != 0);
372
373			# track any sort of multi-line comment.  Obviously if
374			# the added text or context do not include the whole
375			# comment we will not see it. Such is life.
376			#
377			# Guestimate if this is a continuing comment.  If this
378			# is the start of a diff block and this line starts
379			# ' *' then it is very likely a comment.
380			if ($linenr == $first_line and $line =~ m@^.\s*\*@) {
381				$in_comment = 1;
382			}
383			if ($line =~ m@/\*@) {
384				$in_comment = 1;
385			}
386			if ($line =~ m@\*/@) {
387				$in_comment = 0;
388			}
389
390			# Measure the line length and indent.
391			($length, $indent) = line_stats($line);
392
393			# Track the previous line.
394			($prevline, $stashline) = ($stashline, $line);
395			($previndent, $stashindent) = ($stashindent, $indent);
396		} elsif ($realcnt == 1) {
397			$realcnt--;
398		}
399
400#make up the handle for any error we report on this line
401		$here = "#$linenr: ";
402		$here .= "FILE: $realfile:$realline:" if ($realcnt != 0);
403
404		my $hereline = "$here\n$line\n";
405		my $herecurr = "$here\n$line\n";
406		my $hereprev = "$here\n$prevline\n$line\n";
407
408#check the patch for a signoff:
409		if ($line =~ /^\s*signed-off-by:/i) {
410			# This is a signoff, if ugly, so do not double report.
411			$signoff++;
412			if (!($line =~ /^\s*Signed-off-by:/)) {
413				WARN("Signed-off-by: is the preferred form\n" .
414					$herecurr);
415			}
416			if ($line =~ /^\s*signed-off-by:\S/i) {
417				WARN("need space after Signed-off-by:\n" .
418					$herecurr);
419			}
420		}
421
422# Check for wrappage within a valid hunk of the file
423		if ($realcnt != 0 && $line !~ m{^(?:\+|-| |$)}) {
424			ERROR("patch seems to be corrupt (line wrapped?)\n" .
425				$herecurr);
426		}
427
428# UTF-8 regex found at http://www.w3.org/International/questions/qa-forms-utf-8.en.php
429		if (($realfile =~ /^$/ || $line =~ /^\+/) &&
430		     !($line =~ m/^(
431				[\x09\x0A\x0D\x20-\x7E]              # ASCII
432				| [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte
433				|  \xE0[\xA0-\xBF][\x80-\xBF]        # excluding overlongs
434				| [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte
435				|  \xED[\x80-\x9F][\x80-\xBF]        # excluding surrogates
436				|  \xF0[\x90-\xBF][\x80-\xBF]{2}     # planes 1-3
437				| [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15
438				|  \xF4[\x80-\x8F][\x80-\xBF]{2}     # plane 16
439				)*$/x )) {
440			ERROR("Invalid UTF-8\n" . $herecurr);
441		}
442
443#ignore lines being removed
444		if ($line=~/^-/) {next;}
445
446# check we are in a valid source file if not then ignore this hunk
447		next if ($realfile !~ /\.(h|c|s|S|pl|sh)$/);
448
449#trailing whitespace
450		if ($line =~ /^\+.*\S\s+$/ || $line =~ /^\+\s+$/) {
451			my $herevet = "$here\n" . cat_vet($line) . "\n";
452			ERROR("trailing whitespace\n" . $herevet);
453		}
454#80 column limit
455		if ($line =~ /^\+/ && !($prevline=~/\/\*\*/) && $length > 80) {
456			WARN("line over 80 characters\n" . $herecurr);
457		}
458
459# check we are in a valid source file *.[hc] if not then ignore this hunk
460		next if ($realfile !~ /\.[hc]$/);
461
462# at the beginning of a line any tabs must come first and anything
463# more than 8 must use tabs.
464		if ($line=~/^\+\s* \t\s*\S/ or $line=~/^\+\s*        \s*/) {
465			my $herevet = "$here\n" . cat_vet($line) . "\n";
466			ERROR("use tabs not spaces\n" . $herevet);
467		}
468
469		#
470		# The rest of our checks refer specifically to C style
471		# only apply those _outside_ comments.
472		#
473		next if ($in_comment);
474
475# Remove comments from the line before processing.
476		$line =~ s@/\*.*\*/@@g;
477		$line =~ s@/\*.*@@;
478		$line =~ s@.*\*/@@;
479
480# Standardise the strings and chars within the input to simplify matching.
481		$line = sanitise_line($line);
482
483#
484# Checks which may be anchored in the context.
485#
486
487# Check for switch () and associated case and default
488# statements should be at the same indent.
489		if ($line=~/\bswitch\s*\(.*\)/) {
490			my $err = '';
491			my $sep = '';
492			my @ctx = ctx_block_outer($linenr, $realcnt);
493			shift(@ctx);
494			for my $ctx (@ctx) {
495				my ($clen, $cindent) = line_stats($ctx);
496				if ($ctx =~ /^\+\s*(case\s+|default:)/ &&
497							$indent != $cindent) {
498					$err .= "$sep$ctx\n";
499					$sep = '';
500				} else {
501					$sep = "[...]\n";
502				}
503			}
504			if ($err ne '') {
505				ERROR("switch and case should be at the same indent\n$hereline\n$err\n");
506			}
507		}
508
509# if/while/etc brace do not go on next line, unless defining a do while loop,
510# or if that brace on the next line is for something else
511		if ($line =~ /\b(?:(if|while|for|switch)\s*\(|do\b|else\b)/ && $line !~ /^.#/) {
512			my @ctx = ctx_statement($linenr, $realcnt);
513			my $ctx_ln = $linenr + $#ctx + 1;
514			my $ctx_cnt = $realcnt - $#ctx - 1;
515			my $ctx = join("\n", @ctx);
516
517			while ($ctx_cnt > 0 && $lines[$ctx_ln - 1] =~ /^-/) {
518				$ctx_ln++;
519				$ctx_cnt--;
520			}
521			##warn "line<$line>\nctx<$ctx>\nnext<$lines[$ctx_ln - 1]>";
522
523			if ($ctx !~ /{\s*/ && $ctx_cnt > 0 && $lines[$ctx_ln - 1] =~ /^\+\s*{/) {
524				ERROR("That { should be on the previous line\n" .
525					"$here\n$ctx\n$lines[$ctx_ln - 1]");
526			}
527		}
528
529#ignore lines not being added
530		if ($line=~/^[^\+]/) {next;}
531
532# TEST: allow direct testing of the type matcher.
533		if ($tst_type && $line =~ /^.$Declare$/) {
534			ERROR("TEST: is type $Declare\n" . $herecurr);
535			next;
536		}
537
538#
539# Checks which are anchored on the added line.
540#
541
542# check for malformed paths in #include statements (uses RAW line)
543		if ($rawline =~ m{^.#\s*include\s+[<"](.*)[">]}) {
544			my $path = $1;
545			if ($path =~ m{//}) {
546				ERROR("malformed #include filename\n" .
547					$herecurr);
548			}
549			# Sanitise this special form of string.
550			$path = 'X' x length($path);
551			$line =~ s{\<.*\>}{<$path>};
552		}
553
554# no C99 // comments
555		if ($line =~ m{//}) {
556			ERROR("do not use C99 // comments\n" . $herecurr);
557		}
558		# Remove C99 comments.
559		$line =~ s@//.*@@;
560
561#EXPORT_SYMBOL should immediately follow its function closing }.
562		if (($line =~ /EXPORT_SYMBOL.*\((.*)\)/) ||
563		    ($line =~ /EXPORT_UNUSED_SYMBOL.*\((.*)\)/)) {
564			my $name = $1;
565			if (($prevline !~ /^}/) &&
566			   ($prevline !~ /^\+}/) &&
567			   ($prevline !~ /^ }/) &&
568			   ($prevline !~ /\s$name(?:\s+$Attribute)?\s*(?:;|=)/)) {
569				WARN("EXPORT_SYMBOL(foo); should immediately follow its function/variable\n" . $herecurr);
570			}
571		}
572
573# check for static initialisers.
574		if ($line=~/\s*static\s.*=\s+(0|NULL);/) {
575			ERROR("do not initialise statics to 0 or NULL\n" .
576				$herecurr);
577		}
578
579# check for new typedefs, only function parameters and sparse annotations
580# make sense.
581		if ($line =~ /\btypedef\s/ &&
582		    $line !~ /\btypedef\s+$Type\s+\(\s*\*$Ident\s*\)\s*\(/ &&
583		    $line !~ /\b__bitwise(?:__|)\b/) {
584			WARN("do not add new typedefs\n" . $herecurr);
585		}
586
587# * goes on variable not on type
588		if ($line =~ m{\($NonptrType(\*+)(?:\s+const)?\)}) {
589			ERROR("\"(foo$1)\" should be \"(foo $1)\"\n" .
590				$herecurr);
591
592		} elsif ($line =~ m{\($NonptrType\s+(\*+)(?!\s+const)\s+\)}) {
593			ERROR("\"(foo $1 )\" should be \"(foo $1)\"\n" .
594				$herecurr);
595
596		} elsif ($line =~ m{$NonptrType(\*+)(?:\s+const)?\s+[A-Za-z\d_]+}) {
597			ERROR("\"foo$1 bar\" should be \"foo $1bar\"\n" .
598				$herecurr);
599
600		} elsif ($line =~ m{$NonptrType\s+(\*+)(?!\s+const)\s+[A-Za-z\d_]+}) {
601			ERROR("\"foo $1 bar\" should be \"foo $1bar\"\n" .
602				$herecurr);
603		}
604
605# # no BUG() or BUG_ON()
606# 		if ($line =~ /\b(BUG|BUG_ON)\b/) {
607# 			print "Try to use WARN_ON & Recovery code rather than BUG() or BUG_ON()\n";
608# 			print "$herecurr";
609# 			$clean = 0;
610# 		}
611
612# printk should use KERN_* levels.  Note that follow on printk's on the
613# same line do not need a level, so we use the current block context
614# to try and find and validate the current printk.  In summary the current
615# printk includes all preceeding printk's which have no newline on the end.
616# we assume the first bad printk is the one to report.
617		if ($line =~ /\bprintk\((?!KERN_)/) {
618			my $ok = 0;
619			for (my $ln = $linenr - 1; $ln >= $first_line; $ln--) {
620				#print "CHECK<$lines[$ln - 1]\n";
621				# we have a preceeding printk if it ends
622				# with "\n" ignore it, else it is to blame
623				if ($lines[$ln - 1] =~ m{\bprintk\(}) {
624					if ($rawlines[$ln - 1] !~ m{\\n"}) {
625						$ok = 1;
626					}
627					last;
628				}
629			}
630			if ($ok == 0) {
631				WARN("printk() should include KERN_ facility level\n" . $herecurr);
632			}
633		}
634
635# function brace can't be on same line, except for #defines of do while,
636# or if closed on same line
637		if (($line=~/$Type\s*[A-Za-z\d_]+\(.*\).* {/) and
638		    !($line=~/\#define.*do\s{/) and !($line=~/}/)) {
639			ERROR("open brace '{' following function declarations go on the next line\n" . $herecurr);
640		}
641
642# Check operator spacing.
643		# Note we expand the line with the leading + as the real
644		# line will be displayed with the leading + and the tabs
645		# will therefore also expand that way.
646		my $opline = $line;
647		$opline = expand_tabs($opline);
648		$opline =~ s/^./ /;
649		if (!($line=~/\#\s*include/)) {
650			my @elements = split(/(<<=|>>=|<=|>=|==|!=|\+=|-=|\*=|\/=|%=|\^=|\|=|&=|->|<<|>>|<|>|=|!|~|&&|\|\||,|\^|\+\+|--|;|&|\||\+|-|\*|\/\/|\/)/, $opline);
651			my $off = 0;
652			for (my $n = 0; $n < $#elements; $n += 2) {
653				$off += length($elements[$n]);
654
655				my $a = '';
656				$a = 'V' if ($elements[$n] ne '');
657				$a = 'W' if ($elements[$n] =~ /\s$/);
658				$a = 'B' if ($elements[$n] =~ /(\[|\()$/);
659				$a = 'O' if ($elements[$n] eq '');
660				$a = 'E' if ($elements[$n] eq '' && $n == 0);
661
662				my $op = $elements[$n + 1];
663
664				my $c = '';
665				if (defined $elements[$n + 2]) {
666					$c = 'V' if ($elements[$n + 2] ne '');
667					$c = 'W' if ($elements[$n + 2] =~ /^\s/);
668					$c = 'B' if ($elements[$n + 2] =~ /^(\)|\]|;)/);
669					$c = 'O' if ($elements[$n + 2] eq '');
670				} else {
671					$c = 'E';
672				}
673
674				# Pick up the preceeding and succeeding characters.
675				my $ca = substr($opline, 0, $off);
676				my $cc = '';
677				if (length($opline) >= ($off + length($elements[$n + 1]))) {
678					$cc = substr($opline, $off + length($elements[$n + 1]));
679				}
680				my $cb = "$ca$;$cc";
681
682				my $ctx = "${a}x${c}";
683
684				my $at = "(ctx:$ctx)";
685
686				my $ptr = (" " x $off) . "^";
687				my $hereptr = "$hereline$ptr\n";
688
689				##print "<$s1:$op:$s2> <$elements[$n]:$elements[$n + 1]:$elements[$n + 2]>\n";
690
691				# ; should have either the end of line or a space or \ after it
692				if ($op eq ';') {
693					if ($ctx !~ /.x[WEB]/ && $cc !~ /^\\/ &&
694					    $cc !~ /^;/) {
695						ERROR("need space after that '$op' $at\n" . $hereptr);
696					}
697
698				# // is a comment
699				} elsif ($op eq '//') {
700
701				# -> should have no spaces
702				} elsif ($op eq '->') {
703					if ($ctx =~ /Wx.|.xW/) {
704						ERROR("no spaces around that '$op' $at\n" . $hereptr);
705					}
706
707				# , must have a space on the right.
708				} elsif ($op eq ',') {
709					if ($ctx !~ /.xW|.xE/ && $cc !~ /^}/) {
710						ERROR("need space after that '$op' $at\n" . $hereptr);
711					}
712
713				# unary ! and unary ~ are allowed no space on the right
714				} elsif ($op eq '!' or $op eq '~') {
715					if ($ctx !~ /[WOEB]x./) {
716						ERROR("need space before that '$op' $at\n" . $hereptr);
717					}
718					if ($ctx =~ /.xW/) {
719						ERROR("no space after that '$op' $at\n" . $hereptr);
720					}
721
722				# unary ++ and unary -- are allowed no space on one side.
723				} elsif ($op eq '++' or $op eq '--') {
724					if ($ctx !~ /[WOB]x[^W]/ && $ctx !~ /[^W]x[WOBE]/) {
725						ERROR("need space one side of that '$op' $at\n" . $hereptr);
726					}
727					if ($ctx =~ /Wx./ && $cc =~ /^;/) {
728						ERROR("no space before that '$op' $at\n" . $hereptr);
729					}
730
731				# & is both unary and binary
732				# unary:
733				# 	a &b
734				# binary (consistent spacing):
735				#	a&b		OK
736				#	a & b		OK
737				#
738				# boiling down to: if there is a space on the right then there
739				# should be one on the left.
740				#
741				# - is the same
742				#
743				} elsif ($op eq '&' or $op eq '-') {
744					if ($ctx !~ /VxV|[EW]x[WE]|[EWB]x[VO]/) {
745						ERROR("need space before that '$op' $at\n" . $hereptr);
746					}
747
748				# * is the same as & only adding:
749				# type:
750				# 	(foo *)
751				#	(foo **)
752				#
753				} elsif ($op eq '*') {
754					if ($ca !~ /$Type$/ && $cb !~ /(\*$;|$;\*)/ &&
755					    $ctx !~ /VxV|[EW]x[WE]|[EWB]x[VO]|OxV|WxB|BxB/) {
756						ERROR("need space before that '$op' $at\n" . $hereptr);
757					}
758
759				# << and >> may either have or not have spaces both sides
760				} elsif ($op eq '<<' or $op eq '>>' or $op eq '+' or $op eq '/' or
761					 $op eq '^' or $op eq '|')
762				{
763					if ($ctx !~ /VxV|WxW|VxE|WxE/) {
764						ERROR("need consistent spacing around '$op' $at\n" .
765							$hereptr);
766					}
767
768				# All the others need spaces both sides.
769				} elsif ($ctx !~ /[EW]x[WE]/) {
770					ERROR("need spaces around that '$op' $at\n" . $hereptr);
771				}
772				$off += length($elements[$n + 1]);
773			}
774		}
775
776#need space before brace following if, while, etc
777		if ($line =~ /\(.*\){/ || $line =~ /do{/) {
778			ERROR("need a space before the open brace '{'\n" . $herecurr);
779		}
780
781# closing brace should have a space following it when it has anything
782# on the line
783		if ($line =~ /}(?!(?:,|;|\)))\S/) {
784			ERROR("need a space after that close brace '}'\n" . $herecurr);
785		}
786
787#goto labels aren't indented, allow a single space however
788		if ($line=~/^.\s+[A-Za-z\d_]+:(?![0-9]+)/ and
789		   !($line=~/^. [A-Za-z\d_]+:/) and !($line=~/^.\s+default:/)) {
790			WARN("labels should not be indented\n" . $herecurr);
791		}
792
793# Need a space before open parenthesis after if, while etc
794		if ($line=~/\b(if|while|for|switch)\(/) {
795			ERROR("need a space before the open parenthesis '('\n" . $herecurr);
796		}
797
798# Check for illegal assignment in if conditional.
799		if ($line=~/\bif\s*\(.*[^<>!=]=[^=].*\)/) {
800			#next if ($line=~/\".*\Q$op\E.*\"/ or $line=~/\'\Q$op\E\'/);
801			ERROR("do not use assignment in if condition\n" . $herecurr);
802		}
803
804		# Check for }<nl>else {, these must be at the same
805		# indent level to be relevant to each other.
806		if ($prevline=~/}\s*$/ and $line=~/^.\s*else\s*/ and
807						$previndent == $indent) {
808			ERROR("else should follow close brace '}'\n" . $hereprev);
809		}
810
811#studly caps, commented out until figure out how to distinguish between use of existing and adding new
812#		if (($line=~/[\w_][a-z\d]+[A-Z]/) and !($line=~/print/)) {
813#		    print "No studly caps, use _\n";
814#		    print "$herecurr";
815#		    $clean = 0;
816#		}
817
818#no spaces allowed after \ in define
819		if ($line=~/\#define.*\\\s$/) {
820			WARN("Whitepspace after \\ makes next lines useless\n" . $herecurr);
821		}
822
823#warn if <asm/foo.h> is #included and <linux/foo.h> is available (uses RAW line)
824		if ($tree && $rawline =~ m{^.\#\s*include\s*\<asm\/(.*)\.h\>}) {
825			my $checkfile = "include/linux/$1.h";
826			if (-f $checkfile) {
827				CHK("Use #include <linux/$1.h> instead of <asm/$1.h>\n" .
828					$herecurr);
829			}
830		}
831
832# if and else should not have general statements after it
833		if ($line =~ /^.\s*(?:}\s*)?else\b(.*)/ &&
834		    $1 !~ /^\s*(?:\sif|{|\\|$)/) {
835			ERROR("trailing statements should be on next line\n" . $herecurr);
836		}
837
838# multi-statement macros should be enclosed in a do while loop, grab the
839# first statement and ensure its the whole macro if its not enclosed
840# in a known goot container
841		if (($prevline=~/\#define.*\\/) and
842		   !($prevline=~/do\s+{/) and !($prevline=~/\(\{/) and
843		   !($line=~/do.*{/) and !($line=~/\(\{/) and
844		   !($line=~/^.\s*$Declare\s/)) {
845			# Grab the first statement, if that is the entire macro
846			# its ok.  This may start either on the #define line
847			# or the one below.
848			my $ln = $linenr;
849			my $cnt = $realcnt;
850
851			# If the macro starts on the define line start there.
852			if ($prevline !~ m{^.#\s*define\s*$Ident(?:\([^\)]*\))?\s*\\\s*$}) {
853				$ln--;
854				$cnt++;
855			}
856			my @ctx = ctx_statement($ln, $cnt);
857			my $ctx_ln = $ln + $#ctx + 1;
858			my $ctx = join("\n", @ctx);
859
860			# Pull in any empty extension lines.
861			while ($ctx =~ /\\$/ &&
862			       $lines[$ctx_ln - 1] =~ /^.\s*(?:\\)?$/) {
863				$ctx .= $lines[$ctx_ln - 1];
864				$ctx_ln++;
865			}
866
867			if ($ctx =~ /\\$/) {
868				if ($ctx =~ /;/) {
869					ERROR("Macros with multiple statements should be enclosed in a do - while loop\n" . "$here\n$ctx\n");
870				} else {
871					ERROR("Macros with complex values should be enclosed in parenthesis\n" . "$here\n$ctx\n");
872				}
873			}
874		}
875
876# don't include deprecated include files (uses RAW line)
877		for my $inc (@dep_includes) {
878			if ($rawline =~ m@\#\s*include\s*\<$inc>@) {
879				ERROR("Don't use <$inc>: see Documentation/feature-removal-schedule.txt\n" . $herecurr);
880			}
881		}
882
883# don't use deprecated functions
884		for my $func (@dep_functions) {
885			if ($line =~ /\b$func\b/) {
886				ERROR("Don't use $func(): see Documentation/feature-removal-schedule.txt\n" . $herecurr);
887			}
888		}
889
890# no volatiles please
891		if ($line =~ /\bvolatile\b/ && $line !~ /\basm\s+volatile\b/) {
892			WARN("Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt\n" . $herecurr);
893		}
894
895# warn about #if 0
896		if ($line =~ /^.#\s*if\s+0\b/) {
897			CHK("if this code is redundant consider removing it\n" .
898				$herecurr);
899		}
900
901# warn about #ifdefs in C files
902#		if ($line =~ /^.#\s*if(|n)def/ && ($realfile =~ /\.c$/)) {
903#			print "#ifdef in C files should be avoided\n";
904#			print "$herecurr";
905#			$clean = 0;
906#		}
907
908# check for spinlock_t definitions without a comment.
909		if ($line =~ /^.\s*(struct\s+mutex|spinlock_t)\s+\S+;/) {
910			my $which = $1;
911			if (!ctx_has_comment($first_line, $linenr)) {
912				CHK("$1 definition without comment\n" . $herecurr);
913			}
914		}
915# check for memory barriers without a comment.
916		if ($line =~ /\b(mb|rmb|wmb|read_barrier_depends|smp_mb|smp_rmb|smp_wmb|smp_read_barrier_depends)\(/) {
917			if (!ctx_has_comment($first_line, $linenr)) {
918				CHK("memory barrier without comment\n" . $herecurr);
919			}
920		}
921# check of hardware specific defines
922		if ($line =~ m@^.#\s*if.*\b(__i386__|__powerpc64__|__sun__|__s390x__)\b@) {
923			CHK("architecture specific defines should be avoided\n" .  $herecurr);
924		}
925
926# check the location of the inline attribute, that it is between
927# storage class and type.
928		if ($line =~ /$Type\s+(?:inline|__always_inline)\b/ ||
929		    $line =~ /\b(?:inline|always_inline)\s+$Storage/) {
930			ERROR("inline keyword should sit between storage class and type\n" . $herecurr);
931		}
932
933# check for new externs in .c files.
934		if ($line =~ /^.\s*extern\s/ && ($realfile =~ /\.c$/)) {
935			WARN("externs should be avoided in .c files\n" .  $herecurr);
936		}
937
938# checks for new __setup's
939		if ($rawline =~ /\b__setup\("([^"]*)"/) {
940			my $name = $1;
941
942			if (!grep(/$name/, @setup_docs)) {
943				CHK("__setup appears un-documented -- check Documentation/kernel-parameters.txt\n" . $herecurr);
944			}
945		}
946	}
947
948	if ($chk_patch && !$is_patch) {
949		ERROR("Does not appear to be a unified-diff format patch\n");
950	}
951	if ($is_patch && $chk_signoff && $signoff == 0) {
952		ERROR("Missing Signed-off-by: line(s)\n");
953	}
954
955	if ($clean == 1 && $quiet == 0) {
956		print "Your patch has no obvious style problems and is ready for submission.\n"
957	}
958	if ($clean == 0 && $quiet == 0) {
959		print "Your patch has style problems, please review.  If any of these errors\n";
960		print "are false positives report them to the maintainer, see\n";
961		print "CHECKPATCH in MAINTAINERS.\n";
962	}
963	return $clean;
964}
965