summaryrefslogblamecommitdiff
path: root/scripts/checkpatch.pl
blob: e216d49624b76afccae5ef6981fe270dc9caa15e (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595


















































































































































































































































































































































































































































































































































































































                                                                                                                                                                           
#!/usr/bin/perl -w
# (c) 2001, Dave Jones. <davej@codemonkey.org.uk> (the file handling bit)
# (c) 2005, Joel Scohpp <jschopp@austin.ibm.com> (the ugly bit)
# (c) 2007, Andy Whitcroft <apw@uk.ibm.com> (new conditions, test suite, etc)
# Licensed under the terms of the GNU GPL License version 2

use strict;

my $P = $0;

my $V = '0.01';

use Getopt::Long qw(:config no_auto_abbrev);

my $quiet = 0;
my $tree = 1;
my $chk_signoff = 1;
my $chk_patch = 1;
GetOptions(
	'q|quiet'	=> \$quiet,
	'tree!'		=> \$tree,
	'signoff!'	=> \$chk_signoff,
	'patch!'	=> \$chk_patch,
) or exit;

my $exit = 0;

if ($#ARGV < 0) {
	print "usage: patchstylecheckemail.pl [options] patchfile\n";
	print "version: $V\n";
	print "options: -q           => quiet\n";
	print "         --no-tree    => run without a kernel tree\n";
	exit(1);
}

if ($tree && !top_of_kernel_tree()) {
	print "Must be run from the top-level dir. of a kernel tree\n";
	exit(2);
}

my @deprecated = ();
my $removal = 'Documentation/feature-removal-schedule.txt';
if ($tree && -f $removal) {
	open(REMOVE, "<$removal") || die "$P: $removal: open failed - $!\n";
	while (<REMOVE>) {
		if (/^Files:\s+(.*\S)/) {
			for my $file (split(/[, ]+/, $1)) {
				if ($file =~ m@include/(.*)@) {
					push(@deprecated, $1);
				}
			}
		}
	}
}

my @lines = ();
while (<>) {
	chomp;
	push(@lines, $_);
	if (eof(ARGV)) {
		if (!process($ARGV, @lines)) {
			$exit = 1;
		}
		@lines = ();
	}
}

exit($exit);

sub top_of_kernel_tree {
	if ((-f "COPYING") && (-f "CREDITS") && (-f "Kbuild") &&
	    (-f "MAINTAINERS") && (-f "Makefile") && (-f "README") &&
	    (-d "Documentation") && (-d "arch") && (-d "include") &&
	    (-d "drivers") && (-d "fs") && (-d "init") && (-d "ipc") &&
	    (-d "kernel") && (-d "lib") && (-d "scripts")) {
		return 1;
	}
	return 0;
}

sub expand_tabs {
	my ($str) = @_;

	my $res = '';
	my $n = 0;
	for my $c (split(//, $str)) {
		if ($c eq "\t") {
			$res .= ' ';
			$n++;
			for (; ($n % 8) != 0; $n++) {
				$res .= ' ';
			}
			next;
		}
		$res .= $c;
		$n++;
	}

	return $res;
}

sub cat_vet {
	my ($vet) = @_;

	$vet =~ s/\t/^I/;
	$vet =~ s/$/\$/;

	return $vet;
}

sub process {
	my $filename = shift;
	my @lines = @_;

	my $linenr=0;
	my $prevline="";
	my $stashline="";

	my $lineforcounting='';
	my $indent;
	my $previndent=0;
	my $stashindent=0;

	my $clean = 1;
	my $signoff = 0;
	my $is_patch = 0;

	# Trace the real file/line as we go.
	my $realfile = '';
	my $realline = 0;
	my $realcnt = 0;
	my $here = '';
	my $in_comment = 0;
	my $first_line = 0;

	foreach my $line (@lines) {
		$linenr++;

#extract the filename as it passes
		if ($line=~/^\+\+\+\s+(\S+)/) {
			$realfile=$1;
			$in_comment = 0;
			next;
		}
#extract the line range in the file after the patch is applied
		if ($line=~/^\@\@ -\d+,\d+ \+(\d+)(,(\d+))? \@\@/) {
			$is_patch = 1;
			$first_line = 1;
			$in_comment = 0;
			$realline=$1-1;
			if (defined $2) {
				$realcnt=$3+1;
			} else {
				$realcnt=1+1;
			}
			next;
		}

#track the line number as we move through the hunk
		if ($line=~/^[ \+]/) {
			$realline++;
			$realcnt-- if ($realcnt != 0);

			# track any sort of multi-line comment.  Obviously if
			# the added text or context do not include the whole
			# comment we will not see it. Such is life.
			#
			# Guestimate if this is a continuing comment.  If this
			# is the start of a diff block and this line starts
			# ' *' then it is very likely a comment.
			if ($first_line and $line =~ m@^.\s*\*@) {
				$in_comment = 1;
			}
			if ($line =~ m@/\*@) {
				$in_comment = 1;
			}
			if ($line =~ m@\*/@) {
				$in_comment = 0;
			}

			$lineforcounting = $line;
			$lineforcounting =~ s/^\+//;
			$lineforcounting = expand_tabs($lineforcounting);

			my ($white) = ($lineforcounting =~ /^(\s*)/);
			$indent = length($white);

			# Track the previous line.
			($prevline, $stashline) = ($stashline, $line);
			($previndent, $stashindent) = ($stashindent, $indent);
			$first_line = 0;
		}

#make up the handle for any error we report on this line
		$here = "PATCH: $ARGV:$linenr:";
		$here .= "\nFILE: $realfile:$realline:" if ($realcnt != 0);

		my $herecurr = "$here\n$line\n\n";
		my $hereprev = "$here\n$prevline\n$line\n\n";

#check the patch for a signoff:
		if ($line =~ /^\s*Signed-off-by:\s/) {
			$signoff++;

		} elsif ($line =~ /^\s*signed-off-by:/i) {
			if (!($line =~ /^\s*Signed-off-by:/)) {
				print "use Signed-off-by:\n";
				print "$herecurr";
				$clean = 0;
			}
			if ($line =~ /^\s*signed-off-by:\S/i) {
				print "need space after Signed-off-by:\n";
				print "$herecurr";
				$clean = 0;
			}
		}

#ignore lines not being added
		if ($line=~/^[^\+]/) {next;}

# check we are in a valid source file *.[hcsS] if not then ignore this hunk
		next if ($realfile !~ /\.[hcsS]$/);

#trailing whitespace
		if ($line=~/\S\s+$/) {
			my $herevet = "$here\n" . cat_vet($line) . "\n\n";
			print "trailing whitespace\n";
			print "$herevet";
			$clean = 0;
		}
#80 column limit
		if (!($prevline=~/\/\*\*/) && length($lineforcounting) > 80) {
			print "line over 80 characters\n";
			print "$herecurr";
			$clean = 0;
		}

# check we are in a valid source file *.[hc] if not then ignore this hunk
		next if ($realfile !~ /\.[hc]$/);

# at the beginning of a line any tabs must come first and anything
# more than 8 must use tabs.
		if ($line=~/^\+\s* \t\s*\S/ or $line=~/^\+\s*        \s*/) {
			my $herevet = "$here\n" . cat_vet($line) . "\n\n";
			print "use tabs not spaces\n";
			print "$herevet";
			$clean = 0;
		}

		#
		# The rest of our checks refer specifically to C style
		# only apply those _outside_ comments.
		#
		next if ($in_comment);

# no C99 // comments
		if ($line =~ m@//@ and !($line =~ m@\".*//.*\"@)) {
			print "do not use C99 // comments\n";
			print "$herecurr";
			$clean = 0;
		}

		# Remove comments from the line before processing.
		$line =~ s@/\*.*\*/@@g;
		$line =~ s@/\*.*@@;
		$line =~ s@.*\*/@@;
		$line =~ s@//.*@@;

#EXPORT_SYMBOL should immediately follow its function closing }.
		if (($line =~ /EXPORT_SYMBOL.*\(.*\)/) ||
		    ($line =~ /EXPORT_UNUSED_SYMBOL.*\(.*\)/)) {
			if (($prevline !~ /^}/) &&
			   ($prevline !~ /^\+}/) &&
			   ($prevline !~ /^ }/)) {
				print "EXPORT_SYMBOL(func); should immediately follow its function\n";
				print "$herecurr";
				$clean = 0;
			}
		}

		# check for static initialisers.
		if ($line=~/\s*static\s.*=\s+(0|NULL);/) {
			print "do not initialise statics to 0 or NULL\n";
			print "$herecurr";
			$clean = 0;
		}

		# check for new typedefs.
		if ($line=~/\s*typedef\s/) {
			print "do not add new typedefs\n";
			print "$herecurr";
			$clean = 0;
		}

# * goes on variable not on type
		if ($line=~/[A-Za-z\d_]+\* [A-Za-z\d_]+/) {
			print "\"foo* bar\" should be \"foo *bar\"\n";
			print "$herecurr";
			$clean = 0;
		}

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

# printk should use KERN_* levels
		if ($line =~ /\bprintk\((?!KERN_)/) {
			print "printk() should include KERN_ facility level\n";
			print "$herecurr";
			$clean = 0;
		}

#function brace can't be on same line, except for #defines of do while, or if closed on same line
		if (($line=~/[A-Za-z\d_]+\**\s+\**[A-Za-z\d_]+\(.*\).* {/) and
		    !($line=~/\#define.*do\s{/) and !($line=~/}/)) {
			print "braces following function declarations go on the next line\n";
			print "$herecurr";
			$clean = 0;
		}
		my $opline = $line;
		$opline =~ s/^.//;
		if (!($line=~/\#\s*include/)) {
			# Check operator spacing.
			my @elements = split(/(<<=|>>=|<=|>=|==|!=|\+=|-=|\*=|\/=|%=|\^=|\|=|&=|->|<<|>>|<|>|=|!|~|&&|\|\||,|\^|\+\+|--|;|&|\||\+|-|\*|\/\/|\/)/, $opline);
			for (my $n = 0; $n < $#elements; $n += 2) {
				# $wN says we have white-space before or after
				# $sN says we have a separator before or after
				# $oN says we have another operator before or after
				my $w1 = $elements[$n] =~ /\s$/;
				my $s1 = $elements[$n] =~ /(\[|\(|\s)$/;
				my $o1 = $elements[$n] eq '';
				my $op = $elements[$n + 1];
				my $w2 = 1;
				my $s2 = 1;
				my $o2 = 0;
				# If we have something after the operator handle it.
				if (defined $elements[$n + 2]) {
					$w2 = $elements[$n + 2] =~ /^\s/;
					$s2 = $elements[$n + 2] =~ /^(\s|\)|\]|;)/;
					$o2 = $elements[$n + 2] eq '';
				}

				# Generate the context.
				my $at = "here: ";
				for (my $m = $n; $m >= 0; $m--) {
					if ($elements[$m] ne '') {
						$at .= $elements[$m];
						last;
					}
				}
				$at .= $op;
				for (my $m = $n + 2; defined $elements[$m]; $m++) {
					if ($elements[$m] ne '') {
						$at .= $elements[$m];
						last;
					}
				}

				##print "<$s1:$op:$s2> <$elements[$n]:$elements[$n + 1]:$elements[$n + 2]>\n";
				# Skip things apparently in quotes.
				next if ($line=~/\".*\Q$op\E.*\"/ or $line=~/\'\Q$op\E\'/);

				# We need ; as an operator.  // is a comment.
				if ($op eq ';' or $op eq '//') {

				# -> should have no spaces
				} elsif ($op eq '->') {
					if ($s1 or $s2) {
						print "no spaces around that '$op' $at\n";
						print "$herecurr";
						$clean = 0;
					}

				# , must have a space on the right.
				} elsif ($op eq ',') {
					if (!$s2) {
						print "need space after that '$op' $at\n";
						print "$herecurr";
						$clean = 0;
					}

				# unary ! and unary ~ are allowed no space on the right
				} elsif ($op eq '!' or $op eq '~') {
					if (!$s1 && !$o1) {
						print "need space before that '$op' $at\n";
						print "$herecurr";
						$clean = 0;
					}
					if ($s2) {
						print "no space after that '$op' $at\n";
						print "$herecurr";
						$clean = 0;
					}

				# unary ++ and unary -- are allowed no space on one side.
				} elsif ($op eq '++' or $op eq '--') {
					if (($s1 && $s2) || ((!$s1 && !$o1) && (!$s2 && !$o2))) {
						print "need space one side of that '$op' $at\n";
						print "$herecurr";
						$clean = 0;
					}

				# & is both unary and binary
				# unary:
				# 	a &b
				# binary (consistent spacing):
				#	a&b		OK
				#	a & b		OK
				#
				# boiling down to: if there is a space on the right then there
				# should be one on the left.
				#
				# - is the same
				#
				# * is the same only adding:
				# type:
				# 	(foo *)
				#	(foo **)
				#
				} elsif ($op eq '&' or $op eq '-' or $op eq '*') {
					if ($w2 and !$w1) {
						print "need space before that '$op' $at\n";
						print "$herecurr";
						$clean = 0;
					}

				# << and >> may either have or not have spaces both sides
				} elsif ($op eq '<<' or $op eq '>>' or $op eq '+' or $op eq '/' or
					 $op eq '^' or $op eq '|')
				{
					if ($s1 != $s2) {
						print "need consistent spacing around '$op' $at\n";
						print "$herecurr";
						$clean = 0;
					}

				# All the others need spaces both sides.
				} elsif (!$s1 or !$s2) {
					print "need spaces around that '$op' $at\n";
					print "$herecurr";
					$clean = 0;
				}
			}
		}

#need space before brace following if, while, etc
		if ($line=~/\(.*\){/) {
			print "need a space before the brace\n";
			print "$herecurr";
			$clean = 0;
		}

#goto labels aren't indented, allow a single space however
		if ($line=~/^.\s+[A-Za-z\d_]+:/ and
		   !($line=~/^. [A-Za-z\d_]+:/) and !($line=~/^.\s+default:/)) {
			print "labels should not be indented\n";
			print "$herecurr";
			$clean = 0;
		}

# Need a space before open parenthesis after if, while etc
		if ($line=~/(if|while|for|switch)\(/) {
			print "need a space before the open parenthesis\n";
			print "$herecurr";
			$clean = 0;
		}

# Check for illegal assignment in if conditional.
		if ($line=~/(if|while)\s*\(.*[^<>!=]=[^=].*\)/) {
			print "do not use assignment in if condition\n";
			print "$herecurr";
			$clean = 0;
		}

		# 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 == $indent) {
			print "else should follow close brace\n";
			print "$hereprev";
			$clean = 0;
		}

		# Check for switch () {<nl>case, these must be at the
		# same indent.  We will only catch the first one, as our
		# context is very small but people tend to be consistent
		# so we will catch them out more often than not.
		if ($prevline=~/\s*switch\s*\(.*\)/ and $line=~/\s*case\s+/
						and $previndent != $indent) {
			print "switch and case should be at the same indent\n";
			print "$hereprev";
			$clean = 0;
		}

#studly caps, commented out until figure out how to distinguish between use of existing and adding new
#		if (($line=~/[\w_][a-z\d]+[A-Z]/) and !($line=~/print/)) {
#		    print "No studly caps, use _\n";
#		    print "$herecurr";
#		    $clean = 0;
#		}

#no spaces allowed after \ in define
		if ($line=~/\#define.*\\\s$/) {
			print("Whitepspace after \\ makes next lines useless\n");
			print "$herecurr";
			$clean = 0;
		}

#warn if <asm/foo.h> is #included and <linux/foo.h> is available.
		if ($tree && $line =~ qr|\s*\#\s*include\s*\<asm\/(.*)\.h\>|) {
			my $checkfile = "include/linux/$1.h";
			if (-f $checkfile) {
				print "Use #include <linux/$1.h> instead of <asm/$1.h>\n";
				print $herecurr;
				$clean = 0;
			}
		}

#if/while/etc brace do not go on next line, unless #defining a do while loop, or if that brace on the next line is for something else
		if ($prevline=~/(if|while|for|switch)\s*\(/) {
			my @opened = $prevline=~/\(/g;
			my @closed = $prevline=~/\)/g;
			my $nr_line = $linenr;
			my $remaining = $realcnt;
			my $next_line = $line;
			my $extra_lines = 0;
			my $display_segment = $prevline;

			while ($remaining > 0 && scalar @opened > scalar @closed) {
				$prevline .= $next_line;
				$display_segment .= "\n" . $next_line;
				$next_line = $lines[$nr_line];
				$nr_line++;
				$remaining--;

				@opened = $prevline=~/\(/g;
				@closed = $prevline=~/\)/g;
			}

			if (($prevline=~/(if|while|for|switch)\s*\(.*\)\s*$/) and ($next_line=~/{/) and
			   !($next_line=~/(if|while|for)/) and !($next_line=~/\#define.*do.*while/)) {
				print "That { should be on the previous line\n";
				print "$display_segment\n$next_line\n\n";
				$clean = 0;
			}
		}

#multiline macros should be enclosed in a do while loop
		if (($prevline=~/\#define.*\\/) and !($prevline=~/do\s+{/) and
		   !($prevline=~/\(\{/) and ($line=~/;\s*\\/) and
		   !($line=~/do.*{/) and !($line=~/\(\{/)) {
			print "Macros with multiple statements should be enclosed in a do - while loop\n";
			print "$hereprev";
			$clean = 0;
		}

# don't include deprecated include files
		for my $inc (@deprecated) {
			if ($line =~ m@\#\s*include\s*\<$inc>@) {
				print "Don't use <$inc>: see Documentation/feature-removal-schedule.txt\n";
				print "$herecurr";
				$clean = 0;
			}
		}

# don't use kernel_thread()
		if ($line =~ /\bkernel_thread\b/) {
			print "Don't use kernel_thread(), use kthread(): see Documentation/feature-removal-schedule.txt\n";
			print "$herecurr";
			$clean = 0;
		}
	}

	if ($chk_patch && !$is_patch) {
		$clean = 0;
		print "Does not appear to be a unified-diff format patch\n";
	}
	if ($is_patch && $chk_signoff && $signoff == 0) {
		$clean = 0;
		print "Missing Signed-off-by: line(s)\n";
	}

	if ($clean == 1 && $quiet == 0) {
		print "Your patch has no obvious style problems and is ready for submission.\n"
	}
	if ($clean == 0 && $quiet == 0) {
		print "Your patch has style problems, please review.  If any of these errors\n";
		print "are false positives report them to the maintainer, see\n";
		print "CHECKPATCH in MAINTAINERS.\n";
	}
	return $clean;
}