xref: /linux-6.15/scripts/checkpatch.pl (revision 87d37a4f)
1#!/usr/bin/perl -w
2# (c) 2001, Dave Jones. <[email protected]> (the file handling bit)
3# (c) 2005, Joel Scohpp <[email protected]> (the ugly bit)
4# (c) 2007, Andy Whitcroft <[email protected]> (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
11my $V = '0.01';
12
13use Getopt::Long qw(:config no_auto_abbrev);
14
15my $quiet = 0;
16my $tree = 1;
17my $chk_signoff = 1;
18my $chk_patch = 1;
19GetOptions(
20	'q|quiet'	=> \$quiet,
21	'tree!'		=> \$tree,
22	'signoff!'	=> \$chk_signoff,
23	'patch!'	=> \$chk_patch,
24) or exit;
25
26my $exit = 0;
27
28if ($#ARGV < 0) {
29	print "usage: patchstylecheckemail.pl [options] patchfile\n";
30	print "version: $V\n";
31	print "options: -q           => quiet\n";
32	print "         --no-tree    => run without a kernel tree\n";
33	exit(1);
34}
35
36if ($tree && !top_of_kernel_tree()) {
37	print "Must be run from the top-level dir. of a kernel tree\n";
38	exit(2);
39}
40
41my @deprecated = ();
42my $removal = 'Documentation/feature-removal-schedule.txt';
43if ($tree && -f $removal) {
44	open(REMOVE, "<$removal") || die "$P: $removal: open failed - $!\n";
45	while (<REMOVE>) {
46		if (/^Files:\s+(.*\S)/) {
47			for my $file (split(/[, ]+/, $1)) {
48				if ($file =~ m@include/(.*)@) {
49					push(@deprecated, $1);
50				}
51			}
52		}
53	}
54}
55
56my @lines = ();
57while (<>) {
58	chomp;
59	push(@lines, $_);
60	if (eof(ARGV)) {
61		if (!process($ARGV, @lines)) {
62			$exit = 1;
63		}
64		@lines = ();
65	}
66}
67
68exit($exit);
69
70sub top_of_kernel_tree {
71	if ((-f "COPYING") && (-f "CREDITS") && (-f "Kbuild") &&
72	    (-f "MAINTAINERS") && (-f "Makefile") && (-f "README") &&
73	    (-d "Documentation") && (-d "arch") && (-d "include") &&
74	    (-d "drivers") && (-d "fs") && (-d "init") && (-d "ipc") &&
75	    (-d "kernel") && (-d "lib") && (-d "scripts")) {
76		return 1;
77	}
78	return 0;
79}
80
81sub expand_tabs {
82	my ($str) = @_;
83
84	my $res = '';
85	my $n = 0;
86	for my $c (split(//, $str)) {
87		if ($c eq "\t") {
88			$res .= ' ';
89			$n++;
90			for (; ($n % 8) != 0; $n++) {
91				$res .= ' ';
92			}
93			next;
94		}
95		$res .= $c;
96		$n++;
97	}
98
99	return $res;
100}
101
102sub cat_vet {
103	my ($vet) = @_;
104
105	$vet =~ s/\t/^I/;
106	$vet =~ s/$/\$/;
107
108	return $vet;
109}
110
111sub process {
112	my $filename = shift;
113	my @lines = @_;
114
115	my $linenr=0;
116	my $prevline="";
117	my $stashline="";
118
119	my $lineforcounting='';
120	my $indent;
121	my $previndent=0;
122	my $stashindent=0;
123
124	my $clean = 1;
125	my $signoff = 0;
126	my $is_patch = 0;
127
128	# Trace the real file/line as we go.
129	my $realfile = '';
130	my $realline = 0;
131	my $realcnt = 0;
132	my $here = '';
133	my $in_comment = 0;
134	my $first_line = 0;
135
136	foreach my $line (@lines) {
137		$linenr++;
138
139#extract the filename as it passes
140		if ($line=~/^\+\+\+\s+(\S+)/) {
141			$realfile=$1;
142			$in_comment = 0;
143			next;
144		}
145#extract the line range in the file after the patch is applied
146		if ($line=~/^\@\@ -\d+,\d+ \+(\d+)(,(\d+))? \@\@/) {
147			$is_patch = 1;
148			$first_line = 1;
149			$in_comment = 0;
150			$realline=$1-1;
151			if (defined $2) {
152				$realcnt=$3+1;
153			} else {
154				$realcnt=1+1;
155			}
156			next;
157		}
158
159#track the line number as we move through the hunk
160		if ($line=~/^[ \+]/) {
161			$realline++;
162			$realcnt-- if ($realcnt != 0);
163
164			# track any sort of multi-line comment.  Obviously if
165			# the added text or context do not include the whole
166			# comment we will not see it. Such is life.
167			#
168			# Guestimate if this is a continuing comment.  If this
169			# is the start of a diff block and this line starts
170			# ' *' then it is very likely a comment.
171			if ($first_line and $line =~ m@^.\s*\*@) {
172				$in_comment = 1;
173			}
174			if ($line =~ m@/\*@) {
175				$in_comment = 1;
176			}
177			if ($line =~ m@\*/@) {
178				$in_comment = 0;
179			}
180
181			$lineforcounting = $line;
182			$lineforcounting =~ s/^\+//;
183			$lineforcounting = expand_tabs($lineforcounting);
184
185			my ($white) = ($lineforcounting =~ /^(\s*)/);
186			$indent = length($white);
187
188			# Track the previous line.
189			($prevline, $stashline) = ($stashline, $line);
190			($previndent, $stashindent) = ($stashindent, $indent);
191			$first_line = 0;
192		}
193
194#make up the handle for any error we report on this line
195		$here = "PATCH: $ARGV:$linenr:";
196		$here .= "\nFILE: $realfile:$realline:" if ($realcnt != 0);
197
198		my $herecurr = "$here\n$line\n\n";
199		my $hereprev = "$here\n$prevline\n$line\n\n";
200
201#check the patch for a signoff:
202		if ($line =~ /^\s*Signed-off-by:\s/) {
203			$signoff++;
204
205		} elsif ($line =~ /^\s*signed-off-by:/i) {
206			if (!($line =~ /^\s*Signed-off-by:/)) {
207				print "use Signed-off-by:\n";
208				print "$herecurr";
209				$clean = 0;
210			}
211			if ($line =~ /^\s*signed-off-by:\S/i) {
212				print "need space after Signed-off-by:\n";
213				print "$herecurr";
214				$clean = 0;
215			}
216		}
217
218#ignore lines not being added
219		if ($line=~/^[^\+]/) {next;}
220
221# check we are in a valid source file *.[hcsS] if not then ignore this hunk
222		next if ($realfile !~ /\.[hcsS]$/);
223
224#trailing whitespace
225		if ($line=~/\S\s+$/) {
226			my $herevet = "$here\n" . cat_vet($line) . "\n\n";
227			print "trailing whitespace\n";
228			print "$herevet";
229			$clean = 0;
230		}
231#80 column limit
232		if (!($prevline=~/\/\*\*/) && length($lineforcounting) > 80) {
233			print "line over 80 characters\n";
234			print "$herecurr";
235			$clean = 0;
236		}
237
238# check we are in a valid source file *.[hc] if not then ignore this hunk
239		next if ($realfile !~ /\.[hc]$/);
240
241# at the beginning of a line any tabs must come first and anything
242# more than 8 must use tabs.
243		if ($line=~/^\+\s* \t\s*\S/ or $line=~/^\+\s*        \s*/) {
244			my $herevet = "$here\n" . cat_vet($line) . "\n\n";
245			print "use tabs not spaces\n";
246			print "$herevet";
247			$clean = 0;
248		}
249
250		#
251		# The rest of our checks refer specifically to C style
252		# only apply those _outside_ comments.
253		#
254		next if ($in_comment);
255
256# no C99 // comments
257		if ($line =~ m@//@ and !($line =~ m@\".*//.*\"@)) {
258			print "do not use C99 // comments\n";
259			print "$herecurr";
260			$clean = 0;
261		}
262
263		# Remove comments from the line before processing.
264		$line =~ s@/\*.*\*/@@g;
265		$line =~ s@/\*.*@@;
266		$line =~ s@.*\*/@@;
267		$line =~ s@//.*@@;
268
269#EXPORT_SYMBOL should immediately follow its function closing }.
270		if (($line =~ /EXPORT_SYMBOL.*\(.*\)/) ||
271		    ($line =~ /EXPORT_UNUSED_SYMBOL.*\(.*\)/)) {
272			if (($prevline !~ /^}/) &&
273			   ($prevline !~ /^\+}/) &&
274			   ($prevline !~ /^ }/)) {
275				print "EXPORT_SYMBOL(func); should immediately follow its function\n";
276				print "$herecurr";
277				$clean = 0;
278			}
279		}
280
281		# check for static initialisers.
282		if ($line=~/\s*static\s.*=\s+(0|NULL);/) {
283			print "do not initialise statics to 0 or NULL\n";
284			print "$herecurr";
285			$clean = 0;
286		}
287
288		# check for new typedefs.
289		if ($line=~/\s*typedef\s/) {
290			print "do not add new typedefs\n";
291			print "$herecurr";
292			$clean = 0;
293		}
294
295# * goes on variable not on type
296		if ($line=~/[A-Za-z\d_]+\* [A-Za-z\d_]+/) {
297			print "\"foo* bar\" should be \"foo *bar\"\n";
298			print "$herecurr";
299			$clean = 0;
300		}
301
302# # no BUG() or BUG_ON()
303# 		if ($line =~ /\b(BUG|BUG_ON)\b/) {
304# 			print "Try to use WARN_ON & Recovery code rather than BUG() or BUG_ON()\n";
305# 			print "$herecurr";
306# 			$clean = 0;
307# 		}
308
309# printk should use KERN_* levels
310		if ($line =~ /\bprintk\((?!KERN_)/) {
311			print "printk() should include KERN_ facility level\n";
312			print "$herecurr";
313			$clean = 0;
314		}
315
316#function brace can't be on same line, except for #defines of do while, or if closed on same line
317		if (($line=~/[A-Za-z\d_]+\**\s+\**[A-Za-z\d_]+\(.*\).* {/) and
318		    !($line=~/\#define.*do\s{/) and !($line=~/}/)) {
319			print "braces following function declarations go on the next line\n";
320			print "$herecurr";
321			$clean = 0;
322		}
323		my $opline = $line;
324		$opline =~ s/^.//;
325		if (!($line=~/\#\s*include/)) {
326			# Check operator spacing.
327			my @elements = split(/(<<=|>>=|<=|>=|==|!=|\+=|-=|\*=|\/=|%=|\^=|\|=|&=|->|<<|>>|<|>|=|!|~|&&|\|\||,|\^|\+\+|--|;|&|\||\+|-|\*|\/\/|\/)/, $opline);
328			for (my $n = 0; $n < $#elements; $n += 2) {
329				# $wN says we have white-space before or after
330				# $sN says we have a separator before or after
331				# $oN says we have another operator before or after
332				my $w1 = $elements[$n] =~ /\s$/;
333				my $s1 = $elements[$n] =~ /(\[|\(|\s)$/;
334				my $o1 = $elements[$n] eq '';
335				my $op = $elements[$n + 1];
336				my $w2 = 1;
337				my $s2 = 1;
338				my $o2 = 0;
339				# If we have something after the operator handle it.
340				if (defined $elements[$n + 2]) {
341					$w2 = $elements[$n + 2] =~ /^\s/;
342					$s2 = $elements[$n + 2] =~ /^(\s|\)|\]|;)/;
343					$o2 = $elements[$n + 2] eq '';
344				}
345
346				# Generate the context.
347				my $at = "here: ";
348				for (my $m = $n; $m >= 0; $m--) {
349					if ($elements[$m] ne '') {
350						$at .= $elements[$m];
351						last;
352					}
353				}
354				$at .= $op;
355				for (my $m = $n + 2; defined $elements[$m]; $m++) {
356					if ($elements[$m] ne '') {
357						$at .= $elements[$m];
358						last;
359					}
360				}
361
362				##print "<$s1:$op:$s2> <$elements[$n]:$elements[$n + 1]:$elements[$n + 2]>\n";
363				# Skip things apparently in quotes.
364				next if ($line=~/\".*\Q$op\E.*\"/ or $line=~/\'\Q$op\E\'/);
365
366				# We need ; as an operator.  // is a comment.
367				if ($op eq ';' or $op eq '//') {
368
369				# -> should have no spaces
370				} elsif ($op eq '->') {
371					if ($s1 or $s2) {
372						print "no spaces around that '$op' $at\n";
373						print "$herecurr";
374						$clean = 0;
375					}
376
377				# , must have a space on the right.
378				} elsif ($op eq ',') {
379					if (!$s2) {
380						print "need space after that '$op' $at\n";
381						print "$herecurr";
382						$clean = 0;
383					}
384
385				# unary ! and unary ~ are allowed no space on the right
386				} elsif ($op eq '!' or $op eq '~') {
387					if (!$s1 && !$o1) {
388						print "need space before that '$op' $at\n";
389						print "$herecurr";
390						$clean = 0;
391					}
392					if ($s2) {
393						print "no space after that '$op' $at\n";
394						print "$herecurr";
395						$clean = 0;
396					}
397
398				# unary ++ and unary -- are allowed no space on one side.
399				} elsif ($op eq '++' or $op eq '--') {
400					if (($s1 && $s2) || ((!$s1 && !$o1) && (!$s2 && !$o2))) {
401						print "need space one side of that '$op' $at\n";
402						print "$herecurr";
403						$clean = 0;
404					}
405
406				# & is both unary and binary
407				# unary:
408				# 	a &b
409				# binary (consistent spacing):
410				#	a&b		OK
411				#	a & b		OK
412				#
413				# boiling down to: if there is a space on the right then there
414				# should be one on the left.
415				#
416				# - is the same
417				#
418				# * is the same only adding:
419				# type:
420				# 	(foo *)
421				#	(foo **)
422				#
423				} elsif ($op eq '&' or $op eq '-' or $op eq '*') {
424					if ($w2 and !$w1) {
425						print "need space before that '$op' $at\n";
426						print "$herecurr";
427						$clean = 0;
428					}
429
430				# << and >> may either have or not have spaces both sides
431				} elsif ($op eq '<<' or $op eq '>>' or $op eq '+' or $op eq '/' or
432					 $op eq '^' or $op eq '|')
433				{
434					if ($s1 != $s2) {
435						print "need consistent spacing around '$op' $at\n";
436						print "$herecurr";
437						$clean = 0;
438					}
439
440				# All the others need spaces both sides.
441				} elsif (!$s1 or !$s2) {
442					print "need spaces around that '$op' $at\n";
443					print "$herecurr";
444					$clean = 0;
445				}
446			}
447		}
448
449#need space before brace following if, while, etc
450		if ($line=~/\(.*\){/) {
451			print "need a space before the brace\n";
452			print "$herecurr";
453			$clean = 0;
454		}
455
456#goto labels aren't indented, allow a single space however
457		if ($line=~/^.\s+[A-Za-z\d_]+:/ and
458		   !($line=~/^. [A-Za-z\d_]+:/) and !($line=~/^.\s+default:/)) {
459			print "labels should not be indented\n";
460			print "$herecurr";
461			$clean = 0;
462		}
463
464# Need a space before open parenthesis after if, while etc
465		if ($line=~/(if|while|for|switch)\(/) {
466			print "need a space before the open parenthesis\n";
467			print "$herecurr";
468			$clean = 0;
469		}
470
471# Check for illegal assignment in if conditional.
472		if ($line=~/(if|while)\s*\(.*[^<>!=]=[^=].*\)/) {
473			print "do not use assignment in if condition\n";
474			print "$herecurr";
475			$clean = 0;
476		}
477
478		# Check for }<nl>else {, these must be at the same
479		# indent level to be relevant to each other.
480		if ($prevline=~/}\s*$/ and $line=~/^.\s*else\s*/ and
481						$previndent == $indent) {
482			print "else should follow close brace\n";
483			print "$hereprev";
484			$clean = 0;
485		}
486
487		# Check for switch () {<nl>case, these must be at the
488		# same indent.  We will only catch the first one, as our
489		# context is very small but people tend to be consistent
490		# so we will catch them out more often than not.
491		if ($prevline=~/\s*switch\s*\(.*\)/ and $line=~/\s*case\s+/
492						and $previndent != $indent) {
493			print "switch and case should be at the same indent\n";
494			print "$hereprev";
495			$clean = 0;
496		}
497
498#studly caps, commented out until figure out how to distinguish between use of existing and adding new
499#		if (($line=~/[\w_][a-z\d]+[A-Z]/) and !($line=~/print/)) {
500#		    print "No studly caps, use _\n";
501#		    print "$herecurr";
502#		    $clean = 0;
503#		}
504
505#no spaces allowed after \ in define
506		if ($line=~/\#define.*\\\s$/) {
507			print("Whitepspace after \\ makes next lines useless\n");
508			print "$herecurr";
509			$clean = 0;
510		}
511
512#warn if <asm/foo.h> is #included and <linux/foo.h> is available.
513		if ($tree && $line =~ qr|\s*\#\s*include\s*\<asm\/(.*)\.h\>|) {
514			my $checkfile = "include/linux/$1.h";
515			if (-f $checkfile) {
516				print "Use #include <linux/$1.h> instead of <asm/$1.h>\n";
517				print $herecurr;
518				$clean = 0;
519			}
520		}
521
522#if/while/etc brace do not go on next line, unless #defining a do while loop, or if that brace on the next line is for something else
523		if ($prevline=~/(if|while|for|switch)\s*\(/) {
524			my @opened = $prevline=~/\(/g;
525			my @closed = $prevline=~/\)/g;
526			my $nr_line = $linenr;
527			my $remaining = $realcnt;
528			my $next_line = $line;
529			my $extra_lines = 0;
530			my $display_segment = $prevline;
531
532			while ($remaining > 0 && scalar @opened > scalar @closed) {
533				$prevline .= $next_line;
534				$display_segment .= "\n" . $next_line;
535				$next_line = $lines[$nr_line];
536				$nr_line++;
537				$remaining--;
538
539				@opened = $prevline=~/\(/g;
540				@closed = $prevline=~/\)/g;
541			}
542
543			if (($prevline=~/(if|while|for|switch)\s*\(.*\)\s*$/) and ($next_line=~/{/) and
544			   !($next_line=~/(if|while|for)/) and !($next_line=~/\#define.*do.*while/)) {
545				print "That { should be on the previous line\n";
546				print "$display_segment\n$next_line\n\n";
547				$clean = 0;
548			}
549		}
550
551#multiline macros should be enclosed in a do while loop
552		if (($prevline=~/\#define.*\\/) and !($prevline=~/do\s+{/) and
553		   !($prevline=~/\(\{/) and ($line=~/;\s*\\/) and
554		   !($line=~/do.*{/) and !($line=~/\(\{/)) {
555			print "Macros with multiple statements should be enclosed in a do - while loop\n";
556			print "$hereprev";
557			$clean = 0;
558		}
559
560# don't include deprecated include files
561		for my $inc (@deprecated) {
562			if ($line =~ m@\#\s*include\s*\<$inc>@) {
563				print "Don't use <$inc>: see Documentation/feature-removal-schedule.txt\n";
564				print "$herecurr";
565				$clean = 0;
566			}
567		}
568
569# don't use kernel_thread()
570		if ($line =~ /\bkernel_thread\b/) {
571			print "Don't use kernel_thread(), use kthread(): see Documentation/feature-removal-schedule.txt\n";
572			print "$herecurr";
573			$clean = 0;
574		}
575	}
576
577	if ($chk_patch && !$is_patch) {
578		$clean = 0;
579		print "Does not appear to be a unified-diff format patch\n";
580	}
581	if ($is_patch && $chk_signoff && $signoff == 0) {
582		$clean = 0;
583		print "Missing Signed-off-by: line(s)\n";
584	}
585
586	if ($clean == 1 && $quiet == 0) {
587		print "Your patch has no obvious style problems and is ready for submission.\n"
588	}
589	if ($clean == 0 && $quiet == 0) {
590		print "Your patch has style problems, please review.  If any of these errors\n";
591		print "are false positives report them to the maintainer, see\n";
592		print "CHECKPATCH in MAINTAINERS.\n";
593	}
594	return $clean;
595}
596