xref: /linux/scripts/checkpatch.pl (revision aeb3f46252e26acdc60a1a8e31fb1ca6319d9a07)
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 = '0.08';
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 (/^Check:\s+(.*\S)/) {
51			for my $entry (split(/[, ]+/, $1)) {
52				if ($entry =~ m@include/(.*)@) {
53					push(@dep_includes, $1);
54
55				} elsif ($entry !~ m@/@) {
56					push(@dep_functions, $entry);
57				}
58			}
59		}
60	}
61}
62
63my @rawlines = ();
64while (<>) {
65	chomp;
66	push(@rawlines, $_);
67	if (eof(ARGV)) {
68		if (!process($ARGV, @rawlines)) {
69			$exit = 1;
70		}
71		@rawlines = ();
72	}
73}
74
75exit($exit);
76
77sub top_of_kernel_tree {
78	if ((-f "COPYING") && (-f "CREDITS") && (-f "Kbuild") &&
79	    (-f "MAINTAINERS") && (-f "Makefile") && (-f "README") &&
80	    (-d "Documentation") && (-d "arch") && (-d "include") &&
81	    (-d "drivers") && (-d "fs") && (-d "init") && (-d "ipc") &&
82	    (-d "kernel") && (-d "lib") && (-d "scripts")) {
83		return 1;
84	}
85	return 0;
86}
87
88sub expand_tabs {
89	my ($str) = @_;
90
91	my $res = '';
92	my $n = 0;
93	for my $c (split(//, $str)) {
94		if ($c eq "\t") {
95			$res .= ' ';
96			$n++;
97			for (; ($n % 8) != 0; $n++) {
98				$res .= ' ';
99			}
100			next;
101		}
102		$res .= $c;
103		$n++;
104	}
105
106	return $res;
107}
108
109sub line_stats {
110	my ($line) = @_;
111
112	# Drop the diff line leader and expand tabs
113	$line =~ s/^.//;
114	$line = expand_tabs($line);
115
116	# Pick the indent from the front of the line.
117	my ($white) = ($line =~ /^(\s*)/);
118
119	return (length($line), length($white));
120}
121
122sub sanitise_line {
123	my ($line) = @_;
124
125	my $res = '';
126	my $l = '';
127
128	my $quote = '';
129
130	foreach my $c (split(//, $line)) {
131		if ($l ne "\\" && ($c eq "'" || $c eq '"')) {
132			if ($quote eq '') {
133				$quote = $c;
134				$res .= $c;
135				$l = $c;
136				next;
137			} elsif ($quote eq $c) {
138				$quote = '';
139			}
140		}
141		if ($quote && $c ne "\t") {
142			$res .= "X";
143		} else {
144			$res .= $c;
145		}
146
147		$l = $c;
148	}
149
150	return $res;
151}
152
153sub ctx_block_get {
154	my ($linenr, $remain, $outer, $open, $close, $off) = @_;
155	my $line;
156	my $start = $linenr - 1;
157	my $blk = '';
158	my @o;
159	my @c;
160	my @res = ();
161
162	my $level = 0;
163	for ($line = $start; $remain > 0; $line++) {
164		next if ($rawlines[$line] =~ /^-/);
165		$remain--;
166
167		$blk .= $rawlines[$line];
168		foreach my $c (split(//, $rawlines[$line])) {
169			##print "C<$c>L<$level><$open$close>O<$off>\n";
170			if ($off > 0) {
171				$off--;
172				next;
173			}
174
175			if ($c eq $close && $level > 0) {
176				$level--;
177				last if ($level == 0);
178			} elsif ($c eq $open) {
179				$level++;
180			}
181		}
182
183		if (!$outer || $level <= 1) {
184			push(@res, $rawlines[$line]);
185		}
186
187		last if ($level == 0);
188	}
189
190	return ($level, @res);
191}
192sub ctx_block_outer {
193	my ($linenr, $remain) = @_;
194
195	my ($level, @r) = ctx_block_get($linenr, $remain, 1, '{', '}', 0);
196	return @r;
197}
198sub ctx_block {
199	my ($linenr, $remain) = @_;
200
201	my ($level, @r) = ctx_block_get($linenr, $remain, 0, '{', '}', 0);
202	return @r;
203}
204sub ctx_statement {
205	my ($linenr, $remain, $off) = @_;
206
207	my ($level, @r) = ctx_block_get($linenr, $remain, 0, '(', ')', $off);
208	return @r;
209}
210sub ctx_block_level {
211	my ($linenr, $remain) = @_;
212
213	return ctx_block_get($linenr, $remain, 0, '{', '}', 0);
214}
215
216sub ctx_locate_comment {
217	my ($first_line, $end_line) = @_;
218
219	# Catch a comment on the end of the line itself.
220	my ($current_comment) = ($rawlines[$end_line - 1] =~ m@.*(/\*.*\*/)\s*$@);
221	return $current_comment if (defined $current_comment);
222
223	# Look through the context and try and figure out if there is a
224	# comment.
225	my $in_comment = 0;
226	$current_comment = '';
227	for (my $linenr = $first_line; $linenr < $end_line; $linenr++) {
228		my $line = $rawlines[$linenr - 1];
229		#warn "           $line\n";
230		if ($linenr == $first_line and $line =~ m@^.\s*\*@) {
231			$in_comment = 1;
232		}
233		if ($line =~ m@/\*@) {
234			$in_comment = 1;
235		}
236		if (!$in_comment && $current_comment ne '') {
237			$current_comment = '';
238		}
239		$current_comment .= $line . "\n" if ($in_comment);
240		if ($line =~ m@\*/@) {
241			$in_comment = 0;
242		}
243	}
244
245	chomp($current_comment);
246	return($current_comment);
247}
248sub ctx_has_comment {
249	my ($first_line, $end_line) = @_;
250	my $cmt = ctx_locate_comment($first_line, $end_line);
251
252	##print "LINE: $rawlines[$end_line - 1 ]\n";
253	##print "CMMT: $cmt\n";
254
255	return ($cmt ne '');
256}
257
258sub cat_vet {
259	my ($vet) = @_;
260
261	$vet =~ s/\t/^I/;
262	$vet =~ s/$/\$/;
263
264	return $vet;
265}
266
267my @report = ();
268sub report {
269	push(@report, $_[0]);
270}
271sub report_dump {
272	@report;
273}
274sub ERROR {
275	report("ERROR: $_[0]\n");
276	our $clean = 0;
277}
278sub WARN {
279	report("WARNING: $_[0]\n");
280	our $clean = 0;
281}
282sub CHK {
283	report("CHECK: $_[0]\n");
284	our $clean = 0;
285}
286
287sub process {
288	my $filename = shift;
289	my @lines = @_;
290
291	my $linenr=0;
292	my $prevline="";
293	my $stashline="";
294
295	my $length;
296	my $indent;
297	my $previndent=0;
298	my $stashindent=0;
299
300	our $clean = 1;
301	my $signoff = 0;
302	my $is_patch = 0;
303
304	# Trace the real file/line as we go.
305	my $realfile = '';
306	my $realline = 0;
307	my $realcnt = 0;
308	my $here = '';
309	my $in_comment = 0;
310	my $first_line = 0;
311
312	my $Ident	= qr{[A-Za-z\d_]+};
313	my $Storage	= qr{extern|static};
314	my $Sparse	= qr{__user|__kernel|__force|__iomem};
315	my $NonptrType	= qr{
316				\b
317				(?:const\s+)?
318				(?:unsigned\s+)?
319				(?:
320					void|
321					char|
322					short|
323					int|
324					long|
325					unsigned|
326					float|
327					double|
328					long\s+int|
329					long\s+long|
330					long\s+long\s+int|
331					u8|u16|u32|u64|
332					s8|s16|s32|s64|
333					struct\s+$Ident|
334					union\s+$Ident|
335					enum\s+$Ident|
336					${Ident}_t
337				)
338				(?:\s+$Sparse)*
339				\b
340			  }x;
341	my $Type	= qr{
342				\b$NonptrType\b
343				(?:\s*\*+\s*const|\s*\*+)?
344			  }x;
345	my $Declare	= qr{(?:$Storage\s+)?$Type};
346	my $Attribute	= qr{const|__read_mostly|__init|__initdata|__meminit};
347
348	my $Member	= qr{->$Ident|\.$Ident|\[[^]]*\]};
349	my $Lval	= qr{$Ident(?:$Member)*};
350
351	# Pre-scan the patch looking for any __setup documentation.
352	my @setup_docs = ();
353	my $setup_docs = 0;
354	foreach my $line (@lines) {
355		if ($line=~/^\+\+\+\s+(\S+)/) {
356			$setup_docs = 0;
357			if ($1 =~ m@Documentation/kernel-parameters.txt$@) {
358				$setup_docs = 1;
359			}
360			next;
361		}
362
363		if ($setup_docs && $line =~ /^\+/) {
364			push(@setup_docs, $line);
365		}
366	}
367
368	foreach my $line (@lines) {
369		$linenr++;
370
371		my $rawline = $line;
372
373#extract the filename as it passes
374		if ($line=~/^\+\+\+\s+(\S+)/) {
375			$realfile=$1;
376			$realfile =~ s@^[^/]*/@@;
377			$in_comment = 0;
378			next;
379		}
380#extract the line range in the file after the patch is applied
381		if ($line=~/^\@\@ -\d+,\d+ \+(\d+)(,(\d+))? \@\@/) {
382			$is_patch = 1;
383			$first_line = $linenr + 1;
384			$in_comment = 0;
385			$realline=$1-1;
386			if (defined $2) {
387				$realcnt=$3+1;
388			} else {
389				$realcnt=1+1;
390			}
391			next;
392		}
393
394# track the line number as we move through the hunk, note that
395# new versions of GNU diff omit the leading space on completely
396# blank context lines so we need to count that too.
397		if ($line =~ /^( |\+|$)/) {
398			$realline++;
399			$realcnt-- if ($realcnt != 0);
400
401			# track any sort of multi-line comment.  Obviously if
402			# the added text or context do not include the whole
403			# comment we will not see it. Such is life.
404			#
405			# Guestimate if this is a continuing comment.  If this
406			# is the start of a diff block and this line starts
407			# ' *' then it is very likely a comment.
408			if ($linenr == $first_line and $line =~ m@^.\s*\*@) {
409				$in_comment = 1;
410			}
411			if ($line =~ m@/\*@) {
412				$in_comment = 1;
413			}
414			if ($line =~ m@\*/@) {
415				$in_comment = 0;
416			}
417
418			# Measure the line length and indent.
419			($length, $indent) = line_stats($line);
420
421			# Track the previous line.
422			($prevline, $stashline) = ($stashline, $line);
423			($previndent, $stashindent) = ($stashindent, $indent);
424		} elsif ($realcnt == 1) {
425			$realcnt--;
426		}
427
428#make up the handle for any error we report on this line
429		$here = "#$linenr: ";
430		$here .= "FILE: $realfile:$realline:" if ($realcnt != 0);
431
432		my $hereline = "$here\n$line\n";
433		my $herecurr = "$here\n$line\n";
434		my $hereprev = "$here\n$prevline\n$line\n";
435
436#check the patch for a signoff:
437		if ($line =~ /^\s*signed-off-by:/i) {
438			# This is a signoff, if ugly, so do not double report.
439			$signoff++;
440			if (!($line =~ /^\s*Signed-off-by:/)) {
441				WARN("Signed-off-by: is the preferred form\n" .
442					$herecurr);
443			}
444			if ($line =~ /^\s*signed-off-by:\S/i) {
445				WARN("need space after Signed-off-by:\n" .
446					$herecurr);
447			}
448		}
449
450# Check for wrappage within a valid hunk of the file
451		if ($realcnt != 0 && $line !~ m{^(?:\+|-| |$)}) {
452			ERROR("patch seems to be corrupt (line wrapped?)\n" .
453				$herecurr);
454		}
455
456# UTF-8 regex found at http://www.w3.org/International/questions/qa-forms-utf-8.en.php
457		if (($realfile =~ /^$/ || $line =~ /^\+/) &&
458		     !($line =~ m/^(
459				[\x09\x0A\x0D\x20-\x7E]              # ASCII
460				| [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte
461				|  \xE0[\xA0-\xBF][\x80-\xBF]        # excluding overlongs
462				| [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte
463				|  \xED[\x80-\x9F][\x80-\xBF]        # excluding surrogates
464				|  \xF0[\x90-\xBF][\x80-\xBF]{2}     # planes 1-3
465				| [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15
466				|  \xF4[\x80-\x8F][\x80-\xBF]{2}     # plane 16
467				)*$/x )) {
468			ERROR("Invalid UTF-8\n" . $herecurr);
469		}
470
471#ignore lines being removed
472		if ($line=~/^-/) {next;}
473
474# check we are in a valid source file if not then ignore this hunk
475		next if ($realfile !~ /\.(h|c|s|S|pl|sh)$/);
476
477#trailing whitespace
478		if ($line =~ /^\+.*\S\s+$/ || $line =~ /^\+\s+$/) {
479			my $herevet = "$here\n" . cat_vet($line) . "\n";
480			ERROR("trailing whitespace\n" . $herevet);
481		}
482#80 column limit
483		if ($line =~ /^\+/ && !($prevline=~/\/\*\*/) && $length > 80) {
484			WARN("line over 80 characters\n" . $herecurr);
485		}
486
487# check we are in a valid source file *.[hc] if not then ignore this hunk
488		next if ($realfile !~ /\.[hc]$/);
489
490# at the beginning of a line any tabs must come first and anything
491# more than 8 must use tabs.
492		if ($line=~/^\+\s* \t\s*\S/ or $line=~/^\+\s*        \s*/) {
493			my $herevet = "$here\n" . cat_vet($line) . "\n";
494			ERROR("use tabs not spaces\n" . $herevet);
495		}
496
497		#
498		# The rest of our checks refer specifically to C style
499		# only apply those _outside_ comments.
500		#
501		next if ($in_comment);
502
503# Remove comments from the line before processing.
504		$line =~ s@/\*.*\*/@@g;
505		$line =~ s@/\*.*@@;
506		$line =~ s@.*\*/@@;
507
508# Standardise the strings and chars within the input to simplify matching.
509		$line = sanitise_line($line);
510
511#
512# Checks which may be anchored in the context.
513#
514
515# Check for switch () and associated case and default
516# statements should be at the same indent.
517		if ($line=~/\bswitch\s*\(.*\)/) {
518			my $err = '';
519			my $sep = '';
520			my @ctx = ctx_block_outer($linenr, $realcnt);
521			shift(@ctx);
522			for my $ctx (@ctx) {
523				my ($clen, $cindent) = line_stats($ctx);
524				if ($ctx =~ /^\+\s*(case\s+|default:)/ &&
525							$indent != $cindent) {
526					$err .= "$sep$ctx\n";
527					$sep = '';
528				} else {
529					$sep = "[...]\n";
530				}
531			}
532			if ($err ne '') {
533				ERROR("switch and case should be at the same indent\n$hereline\n$err\n");
534			}
535		}
536
537# if/while/etc brace do not go on next line, unless defining a do while loop,
538# or if that brace on the next line is for something else
539		if ($line =~ /\b(?:(if|while|for|switch)\s*\(|do\b|else\b)/ && $line !~ /^.#/) {
540			my @ctx = ctx_statement($linenr, $realcnt, 0);
541			my $ctx_ln = $linenr + $#ctx + 1;
542			my $ctx_cnt = $realcnt - $#ctx - 1;
543			my $ctx = join("\n", @ctx);
544
545			while ($ctx_cnt > 0 && $lines[$ctx_ln - 1] =~ /^-/) {
546				$ctx_ln++;
547				$ctx_cnt--;
548			}
549			##warn "line<$line>\nctx<$ctx>\nnext<$lines[$ctx_ln - 1]>";
550
551			if ($ctx !~ /{\s*/ && $ctx_cnt > 0 && $lines[$ctx_ln - 1] =~ /^\+\s*{/) {
552				ERROR("That open brace { should be on the previous line\n" .
553					"$here\n$ctx\n$lines[$ctx_ln - 1]");
554			}
555		}
556
557#ignore lines not being added
558		if ($line=~/^[^\+]/) {next;}
559
560# TEST: allow direct testing of the type matcher.
561		if ($tst_type && $line =~ /^.$Declare$/) {
562			ERROR("TEST: is type $Declare\n" . $herecurr);
563			next;
564		}
565
566# check for initialisation to aggregates open brace on the next line
567		if ($prevline =~ /$Declare\s*$Ident\s*=\s*$/ &&
568		    $line =~ /^.\s*{/) {
569			ERROR("That open brace { should be on the previous line\n" . $hereprev);
570		}
571
572#
573# Checks which are anchored on the added line.
574#
575
576# check for malformed paths in #include statements (uses RAW line)
577		if ($rawline =~ m{^.#\s*include\s+[<"](.*)[">]}) {
578			my $path = $1;
579			if ($path =~ m{//}) {
580				ERROR("malformed #include filename\n" .
581					$herecurr);
582			}
583			# Sanitise this special form of string.
584			$path = 'X' x length($path);
585			$line =~ s{\<.*\>}{<$path>};
586		}
587
588# no C99 // comments
589		if ($line =~ m{//}) {
590			ERROR("do not use C99 // comments\n" . $herecurr);
591		}
592		# Remove C99 comments.
593		$line =~ s@//.*@@;
594
595#EXPORT_SYMBOL should immediately follow its function closing }.
596		if (($line =~ /EXPORT_SYMBOL.*\((.*)\)/) ||
597		    ($line =~ /EXPORT_UNUSED_SYMBOL.*\((.*)\)/)) {
598			my $name = $1;
599			if (($prevline !~ /^}/) &&
600			   ($prevline !~ /^\+}/) &&
601			   ($prevline !~ /^ }/) &&
602			   ($prevline !~ /\s$name(?:\s+$Attribute)?\s*(?:;|=)/)) {
603				WARN("EXPORT_SYMBOL(foo); should immediately follow its function/variable\n" . $herecurr);
604			}
605		}
606
607# check for external initialisers.
608		if ($line =~ /^.$Type\s*$Ident\s*=\s*(0|NULL);/) {
609			ERROR("do not initialise externals to 0 or NULL\n" .
610				$herecurr);
611		}
612# check for static initialisers.
613		if ($line =~ /\s*static\s.*=\s*(0|NULL);/) {
614			ERROR("do not initialise statics to 0 or NULL\n" .
615				$herecurr);
616		}
617
618# check for new typedefs, only function parameters and sparse annotations
619# make sense.
620		if ($line =~ /\btypedef\s/ &&
621		    $line !~ /\btypedef\s+$Type\s+\(\s*\*$Ident\s*\)\s*\(/ &&
622		    $line !~ /\b__bitwise(?:__|)\b/) {
623			WARN("do not add new typedefs\n" . $herecurr);
624		}
625
626# * goes on variable not on type
627		if ($line =~ m{\($NonptrType(\*+)(?:\s+const)?\)}) {
628			ERROR("\"(foo$1)\" should be \"(foo $1)\"\n" .
629				$herecurr);
630
631		} elsif ($line =~ m{\($NonptrType\s+(\*+)(?!\s+const)\s+\)}) {
632			ERROR("\"(foo $1 )\" should be \"(foo $1)\"\n" .
633				$herecurr);
634
635		} elsif ($line =~ m{$NonptrType(\*+)(?:\s+$Attribute)?\s+[A-Za-z\d_]+}) {
636			ERROR("\"foo$1 bar\" should be \"foo $1bar\"\n" .
637				$herecurr);
638
639		} elsif ($line =~ m{$NonptrType\s+(\*+)(?!\s+$Attribute)\s+[A-Za-z\d_]+}) {
640			ERROR("\"foo $1 bar\" should be \"foo $1bar\"\n" .
641				$herecurr);
642		}
643
644# # no BUG() or BUG_ON()
645# 		if ($line =~ /\b(BUG|BUG_ON)\b/) {
646# 			print "Try to use WARN_ON & Recovery code rather than BUG() or BUG_ON()\n";
647# 			print "$herecurr";
648# 			$clean = 0;
649# 		}
650
651# printk should use KERN_* levels.  Note that follow on printk's on the
652# same line do not need a level, so we use the current block context
653# to try and find and validate the current printk.  In summary the current
654# printk includes all preceeding printk's which have no newline on the end.
655# we assume the first bad printk is the one to report.
656		if ($line =~ /\bprintk\((?!KERN_)\s*"/) {
657			my $ok = 0;
658			for (my $ln = $linenr - 1; $ln >= $first_line; $ln--) {
659				#print "CHECK<$lines[$ln - 1]\n";
660				# we have a preceeding printk if it ends
661				# with "\n" ignore it, else it is to blame
662				if ($lines[$ln - 1] =~ m{\bprintk\(}) {
663					if ($rawlines[$ln - 1] !~ m{\\n"}) {
664						$ok = 1;
665					}
666					last;
667				}
668			}
669			if ($ok == 0) {
670				WARN("printk() should include KERN_ facility level\n" . $herecurr);
671			}
672		}
673
674# function brace can't be on same line, except for #defines of do while,
675# or if closed on same line
676		if (($line=~/$Type\s*[A-Za-z\d_]+\(.*\).* {/) and
677		    !($line=~/\#define.*do\s{/) and !($line=~/}/)) {
678			ERROR("open brace '{' following function declarations go on the next line\n" . $herecurr);
679		}
680
681# check for spaces between functions and their parentheses.
682		if ($line =~ /($Ident)\s+\(/ &&
683		    $1 !~ /^(?:if|for|while|switch|return|volatile)$/ &&
684		    $line !~ /$Type\s+\(/ && $line !~ /^.\#\s*define\b/) {
685			ERROR("no space between function name and open parenthesis '('\n" . $herecurr);
686		}
687# Check operator spacing.
688		# Note we expand the line with the leading + as the real
689		# line will be displayed with the leading + and the tabs
690		# will therefore also expand that way.
691		my $opline = $line;
692		$opline = expand_tabs($opline);
693		$opline =~ s/^./ /;
694		if (!($line=~/\#\s*include/)) {
695			my @elements = split(/(<<=|>>=|<=|>=|==|!=|\+=|-=|\*=|\/=|%=|\^=|\|=|&=|=>|->|<<|>>|<|>|=|!|~|&&|\|\||,|\^|\+\+|--|;|&|\||\+|-|\*|\/\/|\/)/, $opline);
696			my $off = 0;
697			for (my $n = 0; $n < $#elements; $n += 2) {
698				$off += length($elements[$n]);
699
700				my $a = '';
701				$a = 'V' if ($elements[$n] ne '');
702				$a = 'W' if ($elements[$n] =~ /\s$/);
703				$a = 'B' if ($elements[$n] =~ /(\[|\()$/);
704				$a = 'O' if ($elements[$n] eq '');
705				$a = 'E' if ($elements[$n] eq '' && $n == 0);
706
707				my $op = $elements[$n + 1];
708
709				my $c = '';
710				if (defined $elements[$n + 2]) {
711					$c = 'V' if ($elements[$n + 2] ne '');
712					$c = 'W' if ($elements[$n + 2] =~ /^\s/);
713					$c = 'B' if ($elements[$n + 2] =~ /^(\)|\]|;)/);
714					$c = 'O' if ($elements[$n + 2] eq '');
715				} else {
716					$c = 'E';
717				}
718
719				# Pick up the preceeding and succeeding characters.
720				my $ca = substr($opline, 0, $off);
721				my $cc = '';
722				if (length($opline) >= ($off + length($elements[$n + 1]))) {
723					$cc = substr($opline, $off + length($elements[$n + 1]));
724				}
725				my $cb = "$ca$;$cc";
726
727				my $ctx = "${a}x${c}";
728
729				my $at = "(ctx:$ctx)";
730
731				my $ptr = (" " x $off) . "^";
732				my $hereptr = "$hereline$ptr\n";
733
734				##print "<$s1:$op:$s2> <$elements[$n]:$elements[$n + 1]:$elements[$n + 2]>\n";
735
736				# ; should have either the end of line or a space or \ after it
737				if ($op eq ';') {
738					if ($ctx !~ /.x[WEB]/ && $cc !~ /^\\/ &&
739					    $cc !~ /^;/) {
740						ERROR("need space after that '$op' $at\n" . $hereptr);
741					}
742
743				# // is a comment
744				} elsif ($op eq '//') {
745
746				# -> should have no spaces
747				} elsif ($op eq '->') {
748					if ($ctx =~ /Wx.|.xW/) {
749						ERROR("no spaces around that '$op' $at\n" . $hereptr);
750					}
751
752				# , must have a space on the right.
753				} elsif ($op eq ',') {
754					if ($ctx !~ /.xW|.xE/ && $cc !~ /^}/) {
755						ERROR("need space after that '$op' $at\n" . $hereptr);
756					}
757
758				# unary ! and unary ~ are allowed no space on the right
759				} elsif ($op eq '!' or $op eq '~') {
760					if ($ctx !~ /[WOEB]x./) {
761						ERROR("need space before that '$op' $at\n" . $hereptr);
762					}
763					if ($ctx =~ /.xW/) {
764						ERROR("no space after that '$op' $at\n" . $hereptr);
765					}
766
767				# unary ++ and unary -- are allowed no space on one side.
768				} elsif ($op eq '++' or $op eq '--') {
769					if ($ctx !~ /[WOB]x[^W]/ && $ctx !~ /[^W]x[WOBE]/) {
770						ERROR("need space one side of that '$op' $at\n" . $hereptr);
771					}
772					if ($ctx =~ /Wx./ && $cc =~ /^;/) {
773						ERROR("no space before that '$op' $at\n" . $hereptr);
774					}
775
776				# & is both unary and binary
777				# unary:
778				# 	a &b
779				# binary (consistent spacing):
780				#	a&b		OK
781				#	a & b		OK
782				#
783				# boiling down to: if there is a space on the right then there
784				# should be one on the left.
785				#
786				# - is the same
787				#
788				} elsif ($op eq '&' or $op eq '-') {
789					if ($ctx !~ /VxV|[EW]x[WE]|[EWB]x[VO]/) {
790						ERROR("need space before that '$op' $at\n" . $hereptr);
791					}
792
793				# * is the same as & only adding:
794				# type:
795				# 	(foo *)
796				#	(foo **)
797				#
798				} elsif ($op eq '*') {
799					if ($ca !~ /$Type$/ && $cb !~ /(\*$;|$;\*)/ &&
800					    $ctx !~ /VxV|[EW]x[WE]|[EWB]x[VO]|OxV|WxB|BxB/) {
801						ERROR("need space before that '$op' $at\n" . $hereptr);
802					}
803
804				# << and >> may either have or not have spaces both sides
805				} elsif ($op eq '<<' or $op eq '>>' or $op eq '+' or $op eq '/' or
806					 $op eq '^' or $op eq '|')
807				{
808					if ($ctx !~ /VxV|WxW|VxE|WxE/) {
809						ERROR("need consistent spacing around '$op' $at\n" .
810							$hereptr);
811					}
812
813				# All the others need spaces both sides.
814				} elsif ($ctx !~ /[EW]x[WE]/) {
815					ERROR("need spaces around that '$op' $at\n" . $hereptr);
816				}
817				$off += length($elements[$n + 1]);
818			}
819		}
820
821# check for multiple assignments
822		if ($line =~ /^.\s*$Lval\s*=\s*$Lval\s*=(?!=)/) {
823			WARN("multiple assignments should be avoided\n" . $herecurr);
824		}
825
826# check for multiple declarations, allowing for a function declaration
827# continuation.
828		if ($line =~ /^.\s*$Type\s+$Ident(?:\s*=[^,{]*)?\s*,\s*$Ident.*/ &&
829		    $line !~ /^.\s*$Type\s+$Ident(?:\s*=[^,{]*)?\s*,\s*$Type\s*$Ident.*/) {
830			WARN("declaring multiple variables together should be avoided\n" . $herecurr);
831		}
832
833#need space before brace following if, while, etc
834		if ($line =~ /\(.*\){/ || $line =~ /do{/) {
835			ERROR("need a space before the open brace '{'\n" . $herecurr);
836		}
837
838# closing brace should have a space following it when it has anything
839# on the line
840		if ($line =~ /}(?!(?:,|;|\)))\S/) {
841			ERROR("need a space after that close brace '}'\n" . $herecurr);
842		}
843
844#goto labels aren't indented, allow a single space however
845		if ($line=~/^.\s+[A-Za-z\d_]+:(?![0-9]+)/ and
846		   !($line=~/^. [A-Za-z\d_]+:/) and !($line=~/^.\s+default:/)) {
847			WARN("labels should not be indented\n" . $herecurr);
848		}
849
850# Need a space before open parenthesis after if, while etc
851		if ($line=~/\b(if|while|for|switch)\(/) {
852			ERROR("need a space before the open parenthesis '('\n" . $herecurr);
853		}
854
855# Check for illegal assignment in if conditional.
856		if ($line=~/\bif\s*\(.*[^<>!=]=[^=].*\)/) {
857			#next if ($line=~/\".*\Q$op\E.*\"/ or $line=~/\'\Q$op\E\'/);
858			ERROR("do not use assignment in if condition\n" . $herecurr);
859		}
860
861		# Check for }<nl>else {, these must be at the same
862		# indent level to be relevant to each other.
863		if ($prevline=~/}\s*$/ and $line=~/^.\s*else\s*/ and
864						$previndent == $indent) {
865			ERROR("else should follow close brace '}'\n" . $hereprev);
866		}
867
868#studly caps, commented out until figure out how to distinguish between use of existing and adding new
869#		if (($line=~/[\w_][a-z\d]+[A-Z]/) and !($line=~/print/)) {
870#		    print "No studly caps, use _\n";
871#		    print "$herecurr";
872#		    $clean = 0;
873#		}
874
875#no spaces allowed after \ in define
876		if ($line=~/\#define.*\\\s$/) {
877			WARN("Whitepspace after \\ makes next lines useless\n" . $herecurr);
878		}
879
880#warn if <asm/foo.h> is #included and <linux/foo.h> is available (uses RAW line)
881		if ($tree && $rawline =~ m{^.\#\s*include\s*\<asm\/(.*)\.h\>}) {
882			my $checkfile = "include/linux/$1.h";
883			if (-f $checkfile) {
884				CHK("Use #include <linux/$1.h> instead of <asm/$1.h>\n" .
885					$herecurr);
886			}
887		}
888
889# if and else should not have general statements after it
890		if ($line =~ /^.\s*(?:}\s*)?else\b(.*)/ &&
891		    $1 !~ /^\s*(?:\sif|{|\\|$)/) {
892			ERROR("trailing statements should be on next line\n" . $herecurr);
893		}
894
895# multi-statement macros should be enclosed in a do while loop, grab the
896# first statement and ensure its the whole macro if its not enclosed
897# in a known goot container
898		if (($prevline=~/\#define.*\\/) and
899		   !($prevline=~/do\s+{/) and !($prevline=~/\(\{/) and
900		   !($line=~/do.*{/) and !($line=~/\(\{/) and
901		   !($line=~/^.\s*$Declare\s/)) {
902			# Grab the first statement, if that is the entire macro
903			# its ok.  This may start either on the #define line
904			# or the one below.
905			my $ln = $linenr;
906			my $cnt = $realcnt;
907			my $off = 0;
908
909			# If the macro starts on the define line start
910			# grabbing the statement after the identifier
911			$prevline =~ m{^(.#\s*define\s*$Ident(?:\([^\)]*\))?\s*)(.*)\\\s*$};
912			##print "1<$1> 2<$2>\n";
913			if ($2 ne '') {
914				$off = length($1);
915				$ln--;
916				$cnt++;
917			}
918			my @ctx = ctx_statement($ln, $cnt, $off);
919			my $ctx_ln = $ln + $#ctx + 1;
920			my $ctx = join("\n", @ctx);
921
922			# Pull in any empty extension lines.
923			while ($ctx =~ /\\$/ &&
924			       $lines[$ctx_ln - 1] =~ /^.\s*(?:\\)?$/) {
925				$ctx .= $lines[$ctx_ln - 1];
926				$ctx_ln++;
927			}
928
929			if ($ctx =~ /\\$/) {
930				if ($ctx =~ /;/) {
931					ERROR("Macros with multiple statements should be enclosed in a do - while loop\n" . "$here\n$ctx\n");
932				} else {
933					ERROR("Macros with complex values should be enclosed in parenthesis\n" . "$here\n$ctx\n");
934				}
935			}
936		}
937
938# check for redundant bracing round if etc
939		if ($line =~ /\b(if|while|for|else)\b/) {
940			# Locate the end of the opening statement.
941			my @control = ctx_statement($linenr, $realcnt, 0);
942			my $nr = $linenr + (scalar(@control) - 1);
943			my $cnt = $realcnt - (scalar(@control) - 1);
944
945			my $off = $realcnt - $cnt;
946			#print "$off: line<$line>end<" . $lines[$nr - 1] . ">\n";
947
948			# If this is is a braced statement group check it
949			if ($lines[$nr - 1] =~ /{\s*$/) {
950				my ($lvl, @block) = ctx_block_level($nr, $cnt);
951
952				my $stmt = join(' ', @block);
953				$stmt =~ s/^[^{]*{//;
954				$stmt =~ s/}[^}]*$//;
955
956				#print "block<" . join(' ', @block) . "><" . scalar(@block) . ">\n";
957				#print "stmt<$stmt>\n\n";
958
959				# Count the ;'s if there is fewer than two
960				# then there can only be one statement,
961				# if there is a brace inside we cannot
962				# trivially detect if its one statement.
963				# Also nested if's often require braces to
964				# disambiguate the else binding so shhh there.
965				my @semi = ($stmt =~ /;/g);
966				##print "semi<" . scalar(@semi) . ">\n";
967				if ($lvl == 0 && scalar(@semi) < 2 &&
968				    $stmt !~ /{/ && $stmt !~ /\bif\b/) {
969				    	my $herectx = "$here\n" . join("\n", @control, @block[1 .. $#block]) . "\n";
970				    	shift(@block);
971					ERROR("braces {} are not necessary for single statement blocks\n" . $herectx);
972				}
973			}
974		}
975
976# don't include deprecated include files (uses RAW line)
977		for my $inc (@dep_includes) {
978			if ($rawline =~ m@\#\s*include\s*\<$inc>@) {
979				ERROR("Don't use <$inc>: see Documentation/feature-removal-schedule.txt\n" . $herecurr);
980			}
981		}
982
983# don't use deprecated functions
984		for my $func (@dep_functions) {
985			if ($line =~ /\b$func\b/) {
986				ERROR("Don't use $func(): see Documentation/feature-removal-schedule.txt\n" . $herecurr);
987			}
988		}
989
990# no volatiles please
991		if ($line =~ /\bvolatile\b/ && $line !~ /\basm\s+volatile\b/) {
992			WARN("Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt\n" . $herecurr);
993		}
994
995# warn about #if 0
996		if ($line =~ /^.#\s*if\s+0\b/) {
997			CHK("if this code is redundant consider removing it\n" .
998				$herecurr);
999		}
1000
1001# check for needless kfree() checks
1002		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
1003			my $expr = $1;
1004			if ($line =~ /\bkfree\(\Q$expr\E\);/) {
1005				WARN("kfree(NULL) is safe this check is probabally not required\n" . $hereprev);
1006			}
1007		}
1008
1009# warn about #ifdefs in C files
1010#		if ($line =~ /^.#\s*if(|n)def/ && ($realfile =~ /\.c$/)) {
1011#			print "#ifdef in C files should be avoided\n";
1012#			print "$herecurr";
1013#			$clean = 0;
1014#		}
1015
1016# check for spinlock_t definitions without a comment.
1017		if ($line =~ /^.\s*(struct\s+mutex|spinlock_t)\s+\S+;/) {
1018			my $which = $1;
1019			if (!ctx_has_comment($first_line, $linenr)) {
1020				CHK("$1 definition without comment\n" . $herecurr);
1021			}
1022		}
1023# check for memory barriers without a comment.
1024		if ($line =~ /\b(mb|rmb|wmb|read_barrier_depends|smp_mb|smp_rmb|smp_wmb|smp_read_barrier_depends)\(/) {
1025			if (!ctx_has_comment($first_line, $linenr)) {
1026				CHK("memory barrier without comment\n" . $herecurr);
1027			}
1028		}
1029# check of hardware specific defines
1030		if ($line =~ m@^.#\s*if.*\b(__i386__|__powerpc64__|__sun__|__s390x__)\b@) {
1031			CHK("architecture specific defines should be avoided\n" .  $herecurr);
1032		}
1033
1034# check the location of the inline attribute, that it is between
1035# storage class and type.
1036		if ($line =~ /$Type\s+(?:inline|__always_inline)\b/ ||
1037		    $line =~ /\b(?:inline|always_inline)\s+$Storage/) {
1038			ERROR("inline keyword should sit between storage class and type\n" . $herecurr);
1039		}
1040
1041# check for new externs in .c files.
1042		if ($line =~ /^.\s*extern\s/ && ($realfile =~ /\.c$/)) {
1043			WARN("externs should be avoided in .c files\n" .  $herecurr);
1044		}
1045
1046# checks for new __setup's
1047		if ($rawline =~ /\b__setup\("([^"]*)"/) {
1048			my $name = $1;
1049
1050			if (!grep(/$name/, @setup_docs)) {
1051				CHK("__setup appears un-documented -- check Documentation/kernel-parameters.txt\n" . $herecurr);
1052			}
1053		}
1054	}
1055
1056	if ($chk_patch && !$is_patch) {
1057		ERROR("Does not appear to be a unified-diff format patch\n");
1058	}
1059	if ($is_patch && $chk_signoff && $signoff == 0) {
1060		ERROR("Missing Signed-off-by: line(s)\n");
1061	}
1062
1063	if ($clean == 0 && ($chk_patch || $is_patch)) {
1064		print report_dump();
1065	}
1066	if ($clean == 1 && $quiet == 0) {
1067		print "Your patch has no obvious style problems and is ready for submission.\n"
1068	}
1069	if ($clean == 0 && $quiet == 0) {
1070		print "Your patch has style problems, please review.  If any of these errors\n";
1071		print "are false positives report them to the maintainer, see\n";
1072		print "CHECKPATCH in MAINTAINERS.\n";
1073	}
1074	return $clean;
1075}
1076