xref: /freebsd/sys/contrib/openzfs/scripts/cstyle.pl (revision 0784121c963e39aa9e8b33c4e0a0c181daf75277)
1#!/usr/bin/env perl
2#
3# CDDL HEADER START
4#
5# The contents of this file are subject to the terms of the
6# Common Development and Distribution License (the "License").
7# You may not use this file except in compliance with the License.
8#
9# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10# or http://www.opensolaris.org/os/licensing.
11# See the License for the specific language governing permissions
12# and limitations under the License.
13#
14# When distributing Covered Code, include this CDDL HEADER in each
15# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16# If applicable, add the following below this CDDL HEADER, with the
17# fields enclosed by brackets "[]" replaced with your own identifying
18# information: Portions Copyright [yyyy] [name of copyright owner]
19#
20# CDDL HEADER END
21#
22# Copyright 2016 Nexenta Systems, Inc.
23#
24# Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
25# Use is subject to license terms.
26#
27# @(#)cstyle 1.58 98/09/09 (from shannon)
28#ident	"%Z%%M%	%I%	%E% SMI"
29#
30# cstyle - check for some common stylistic errors.
31#
32#	cstyle is a sort of "lint" for C coding style.
33#	It attempts to check for the style used in the
34#	kernel, sometimes known as "Bill Joy Normal Form".
35#
36#	There's a lot this can't check for, like proper indentation
37#	of code blocks.  There's also a lot more this could check for.
38#
39#	A note to the non perl literate:
40#
41#		perl regular expressions are pretty much like egrep
42#		regular expressions, with the following special symbols
43#
44#		\s	any space character
45#		\S	any non-space character
46#		\w	any "word" character [a-zA-Z0-9_]
47#		\W	any non-word character
48#		\d	a digit [0-9]
49#		\D	a non-digit
50#		\b	word boundary (between \w and \W)
51#		\B	non-word boundary
52#
53
54require 5.0;
55use warnings;
56use IO::File;
57use Getopt::Std;
58use strict;
59
60my $usage =
61"usage: cstyle [-cghpvCP] [-o constructs] file ...
62	-c	check continuation indentation inside functions
63	-g	print github actions' workflow commands
64	-h	perform heuristic checks that are sometimes wrong
65	-p	perform some of the more picky checks
66	-v	verbose
67	-C	don't check anything in header block comments
68	-P	check for use of non-POSIX types
69	-o constructs
70		allow a comma-separated list of optional constructs:
71		    doxygen	allow doxygen-style block comments (/** /*!)
72		    splint	allow splint-style lint comments (/*@ ... @*/)
73";
74
75my %opts;
76
77if (!getopts("cgho:pvCP", \%opts)) {
78	print $usage;
79	exit 2;
80}
81
82my $check_continuation = $opts{'c'};
83my $github_workflow = $opts{'g'} || $ENV{'CI'};
84my $heuristic = $opts{'h'};
85my $picky = $opts{'p'};
86my $verbose = $opts{'v'};
87my $ignore_hdr_comment = $opts{'C'};
88my $check_posix_types = $opts{'P'};
89
90my $doxygen_comments = 0;
91my $splint_comments = 0;
92
93if (defined($opts{'o'})) {
94	for my $x (split /,/, $opts{'o'}) {
95		if ($x eq "doxygen") {
96			$doxygen_comments = 1;
97		} elsif ($x eq "splint") {
98			$splint_comments = 1;
99		} else {
100			print "cstyle: unrecognized construct \"$x\"\n";
101			print $usage;
102			exit 2;
103		}
104	}
105}
106
107my ($filename, $line, $prev);		# shared globals
108
109my $fmt;
110my $hdr_comment_start;
111
112if ($verbose) {
113	$fmt = "%s: %d: %s\n%s\n";
114} else {
115	$fmt = "%s: %d: %s\n";
116}
117
118if ($doxygen_comments) {
119	# doxygen comments look like "/*!" or "/**"; allow them.
120	$hdr_comment_start = qr/^\s*\/\*[\!\*]?$/;
121} else {
122	$hdr_comment_start = qr/^\s*\/\*$/;
123}
124
125# Note, following must be in single quotes so that \s and \w work right.
126my $typename = '(int|char|short|long|unsigned|float|double' .
127    '|\w+_t|struct\s+\w+|union\s+\w+|FILE)';
128
129# mapping of old types to POSIX compatible types
130my %old2posix = (
131	'unchar' => 'uchar_t',
132	'ushort' => 'ushort_t',
133	'uint' => 'uint_t',
134	'ulong' => 'ulong_t',
135	'u_int' => 'uint_t',
136	'u_short' => 'ushort_t',
137	'u_long' => 'ulong_t',
138	'u_char' => 'uchar_t',
139	'quad' => 'quad_t'
140);
141
142my $lint_re = qr/\/\*(?:
143	NOTREACHED|LINTLIBRARY|VARARGS[0-9]*|
144	CONSTCOND|CONSTANTCOND|CONSTANTCONDITION|EMPTY|
145	FALLTHRU|FALLTHROUGH|LINTED.*?|PRINTFLIKE[0-9]*|
146	PROTOLIB[0-9]*|SCANFLIKE[0-9]*|CSTYLED.*?
147    )\*\//x;
148
149my $splint_re = qr/\/\*@.*?@\*\//x;
150
151my $warlock_re = qr/\/\*\s*(?:
152	VARIABLES\ PROTECTED\ BY|
153	MEMBERS\ PROTECTED\ BY|
154	ALL\ MEMBERS\ PROTECTED\ BY|
155	READ-ONLY\ VARIABLES:|
156	READ-ONLY\ MEMBERS:|
157	VARIABLES\ READABLE\ WITHOUT\ LOCK:|
158	MEMBERS\ READABLE\ WITHOUT\ LOCK:|
159	LOCKS\ COVERED\ BY|
160	LOCK\ UNNEEDED\ BECAUSE|
161	LOCK\ NEEDED:|
162	LOCK\ HELD\ ON\ ENTRY:|
163	READ\ LOCK\ HELD\ ON\ ENTRY:|
164	WRITE\ LOCK\ HELD\ ON\ ENTRY:|
165	LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
166	READ\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
167	WRITE\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
168	LOCK\ RELEASED\ AS\ SIDE\ EFFECT:|
169	LOCK\ UPGRADED\ AS\ SIDE\ EFFECT:|
170	LOCK\ DOWNGRADED\ AS\ SIDE\ EFFECT:|
171	FUNCTIONS\ CALLED\ THROUGH\ POINTER|
172	FUNCTIONS\ CALLED\ THROUGH\ MEMBER|
173	LOCK\ ORDER:
174    )/x;
175
176my $err_stat = 0;		# exit status
177
178if ($#ARGV >= 0) {
179	foreach my $arg (@ARGV) {
180		my $fh = new IO::File $arg, "r";
181		if (!defined($fh)) {
182			printf "%s: can not open\n", $arg;
183		} else {
184			&cstyle($arg, $fh);
185			close $fh;
186		}
187	}
188} else {
189	&cstyle("<stdin>", *STDIN);
190}
191exit $err_stat;
192
193my $no_errs = 0;		# set for CSTYLED-protected lines
194
195sub err($) {
196	my ($error) = @_;
197	unless ($no_errs) {
198		if ($verbose) {
199			printf $fmt, $filename, $., $error, $line;
200		} else {
201			printf $fmt, $filename, $., $error;
202		}
203		if ($github_workflow) {
204			printf "::error file=%s,line=%s::%s\n", $filename, $., $error;
205		}
206		$err_stat = 1;
207	}
208}
209
210sub err_prefix($$) {
211	my ($prevline, $error) = @_;
212	my $out = $prevline."\n".$line;
213	unless ($no_errs) {
214		if ($verbose) {
215			printf $fmt, $filename, $., $error, $out;
216		} else {
217			printf $fmt, $filename, $., $error;
218		}
219		$err_stat = 1;
220	}
221}
222
223sub err_prev($) {
224	my ($error) = @_;
225	unless ($no_errs) {
226		if ($verbose) {
227			printf $fmt, $filename, $. - 1, $error, $prev;
228		} else {
229			printf $fmt, $filename, $. - 1, $error;
230		}
231		$err_stat = 1;
232	}
233}
234
235sub cstyle($$) {
236
237my ($fn, $filehandle) = @_;
238$filename = $fn;			# share it globally
239
240my $in_cpp = 0;
241my $next_in_cpp = 0;
242
243my $in_comment = 0;
244my $in_header_comment = 0;
245my $comment_done = 0;
246my $in_warlock_comment = 0;
247my $in_function = 0;
248my $in_function_header = 0;
249my $function_header_full_indent = 0;
250my $in_declaration = 0;
251my $note_level = 0;
252my $nextok = 0;
253my $nocheck = 0;
254
255my $in_string = 0;
256
257my ($okmsg, $comment_prefix);
258
259$line = '';
260$prev = '';
261reset_indent();
262
263line: while (<$filehandle>) {
264	s/\r?\n$//;	# strip return and newline
265
266	# save the original line, then remove all text from within
267	# double or single quotes, we do not want to check such text.
268
269	$line = $_;
270
271	#
272	# C allows strings to be continued with a backslash at the end of
273	# the line.  We translate that into a quoted string on the previous
274	# line followed by an initial quote on the next line.
275	#
276	# (we assume that no-one will use backslash-continuation with character
277	# constants)
278	#
279	$_ = '"' . $_		if ($in_string && !$nocheck && !$in_comment);
280
281	#
282	# normal strings and characters
283	#
284	s/'([^\\']|\\[^xX0]|\\0[0-9]*|\\[xX][0-9a-fA-F]*)'/''/g;
285	s/"([^\\"]|\\.)*"/\"\"/g;
286
287	#
288	# detect string continuation
289	#
290	if ($nocheck || $in_comment) {
291		$in_string = 0;
292	} else {
293		#
294		# Now that all full strings are replaced with "", we check
295		# for unfinished strings continuing onto the next line.
296		#
297		$in_string =
298		    (s/([^"](?:"")*)"([^\\"]|\\.)*\\$/$1""/ ||
299		    s/^("")*"([^\\"]|\\.)*\\$/""/);
300	}
301
302	#
303	# figure out if we are in a cpp directive
304	#
305	$in_cpp = $next_in_cpp || /^\s*#/;	# continued or started
306	$next_in_cpp = $in_cpp && /\\$/;	# only if continued
307
308	# strip off trailing backslashes, which appear in long macros
309	s/\s*\\$//;
310
311	# an /* END CSTYLED */ comment ends a no-check block.
312	if ($nocheck) {
313		if (/\/\* *END *CSTYLED *\*\//) {
314			$nocheck = 0;
315		} else {
316			reset_indent();
317			next line;
318		}
319	}
320
321	# a /*CSTYLED*/ comment indicates that the next line is ok.
322	if ($nextok) {
323		if ($okmsg) {
324			err($okmsg);
325		}
326		$nextok = 0;
327		$okmsg = 0;
328		if (/\/\* *CSTYLED.*\*\//) {
329			/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
330			$okmsg = $1;
331			$nextok = 1;
332		}
333		$no_errs = 1;
334	} elsif ($no_errs) {
335		$no_errs = 0;
336	}
337
338	# check length of line.
339	# first, a quick check to see if there is any chance of being too long.
340	if (($line =~ tr/\t/\t/) * 7 + length($line) > 80) {
341		# yes, there is a chance.
342		# replace tabs with spaces and check again.
343		my $eline = $line;
344		1 while $eline =~
345		    s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e;
346		if (length($eline) > 80) {
347			err("line > 80 characters");
348		}
349	}
350
351	# ignore NOTE(...) annotations (assumes NOTE is on lines by itself).
352	if ($note_level || /\b_?NOTE\s*\(/) { # if in NOTE or this is NOTE
353		s/[^()]//g;			  # eliminate all non-parens
354		$note_level += s/\(//g - length;  # update paren nest level
355		next;
356	}
357
358	# a /* BEGIN CSTYLED */ comment starts a no-check block.
359	if (/\/\* *BEGIN *CSTYLED *\*\//) {
360		$nocheck = 1;
361	}
362
363	# a /*CSTYLED*/ comment indicates that the next line is ok.
364	if (/\/\* *CSTYLED.*\*\//) {
365		/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
366		$okmsg = $1;
367		$nextok = 1;
368	}
369	if (/\/\/ *CSTYLED/) {
370		/^.*\/\/ *CSTYLED *(.*)$/;
371		$okmsg = $1;
372		$nextok = 1;
373	}
374
375	# universal checks; apply to everything
376	if (/\t +\t/) {
377		err("spaces between tabs");
378	}
379	if (/ \t+ /) {
380		err("tabs between spaces");
381	}
382	if (/\s$/) {
383		err("space or tab at end of line");
384	}
385	if (/[^ \t(]\/\*/ && !/\w\(\/\*.*\*\/\);/) {
386		err("comment preceded by non-blank");
387	}
388	if (/ARGSUSED/) {
389		err("ARGSUSED directive");
390	}
391
392	# is this the beginning or ending of a function?
393	# (not if "struct foo\n{\n")
394	if (/^\{$/ && $prev =~ /\)\s*(const\s*)?(\/\*.*\*\/\s*)?\\?$/) {
395		$in_function = 1;
396		$in_declaration = 1;
397		$in_function_header = 0;
398		$function_header_full_indent = 0;
399		$prev = $line;
400		next line;
401	}
402	if (/^\}\s*(\/\*.*\*\/\s*)*$/) {
403		if ($prev =~ /^\s*return\s*;/) {
404			err_prev("unneeded return at end of function");
405		}
406		$in_function = 0;
407		reset_indent();		# we don't check between functions
408		$prev = $line;
409		next line;
410	}
411	if ($in_function_header && ! /^    (\w|\.)/ ) {
412		if (/^\{\}$/ # empty functions
413		|| /;/ #run function with multiline arguments
414		|| /#/ #preprocessor commands
415		|| /^[^\s\\]*\(.*\)$/ #functions without ; at the end
416		|| /^$/ #function declaration can't have empty line
417		) {
418			$in_function_header = 0;
419			$function_header_full_indent = 0;
420		} elsif ($prev =~ /^__attribute__/) { #__attribute__((*))
421			$in_function_header = 0;
422			$function_header_full_indent = 0;
423			$prev = $line;
424			next line;
425		} elsif ($picky	&& ! (/^\t/ && $function_header_full_indent != 0)) {
426
427			err("continuation line should be indented by 4 spaces");
428		}
429	}
430
431	#
432	# If this matches something of form "foo(", it's probably a function
433	# definition, unless it ends with ") bar;", in which case it's a declaration
434	# that uses a macro to generate the type.
435	#
436	if (/^\w+\(/ && !/\) \w+;/) {
437		$in_function_header = 1;
438		if (/\($/) {
439			$function_header_full_indent = 1;
440		}
441	}
442	if ($in_function_header && /^\{$/) {
443		$in_function_header = 0;
444		$function_header_full_indent = 0;
445		$in_function = 1;
446	}
447	if ($in_function_header && /\);$/) {
448		$in_function_header = 0;
449		$function_header_full_indent = 0;
450	}
451	if ($in_function_header && /\{$/ ) {
452		if ($picky) {
453			err("opening brace on same line as function header");
454		}
455		$in_function_header = 0;
456		$function_header_full_indent = 0;
457		$in_function = 1;
458		next line;
459	}
460
461	if ($in_warlock_comment && /\*\//) {
462		$in_warlock_comment = 0;
463		$prev = $line;
464		next line;
465	}
466
467	# a blank line terminates the declarations within a function.
468	# XXX - but still a problem in sub-blocks.
469	if ($in_declaration && /^$/) {
470		$in_declaration = 0;
471	}
472
473	if ($comment_done) {
474		$in_comment = 0;
475		$in_header_comment = 0;
476		$comment_done = 0;
477	}
478	# does this looks like the start of a block comment?
479	if (/$hdr_comment_start/) {
480		if (!/^\t*\/\*/) {
481			err("block comment not indented by tabs");
482		}
483		$in_comment = 1;
484		/^(\s*)\//;
485		$comment_prefix = $1;
486		if ($comment_prefix eq "") {
487			$in_header_comment = 1;
488		}
489		$prev = $line;
490		next line;
491	}
492	# are we still in the block comment?
493	if ($in_comment) {
494		if (/^$comment_prefix \*\/$/) {
495			$comment_done = 1;
496		} elsif (/\*\//) {
497			$comment_done = 1;
498			err("improper block comment close")
499			    unless ($ignore_hdr_comment && $in_header_comment);
500		} elsif (!/^$comment_prefix \*[ \t]/ &&
501		    !/^$comment_prefix \*$/) {
502			err("improper block comment")
503			    unless ($ignore_hdr_comment && $in_header_comment);
504		}
505	}
506
507	if ($in_header_comment && $ignore_hdr_comment) {
508		$prev = $line;
509		next line;
510	}
511
512	# check for errors that might occur in comments and in code.
513
514	# allow spaces to be used to draw pictures in all comments.
515	if (/[^ ]     / && !/".*     .*"/ && !$in_comment) {
516		err("spaces instead of tabs");
517	}
518	if (/^ / && !/^ \*[ \t\/]/ && !/^ \*$/ &&
519	    (!/^    (\w|\.)/ || $in_function != 0)) {
520		err("indent by spaces instead of tabs");
521	}
522	if (/^\t+ [^ \t\*]/ || /^\t+  \S/ || /^\t+   \S/) {
523		err("continuation line not indented by 4 spaces");
524	}
525	if (/$warlock_re/ && !/\*\//) {
526		$in_warlock_comment = 1;
527		$prev = $line;
528		next line;
529	}
530	if (/^\s*\/\*./ && !/^\s*\/\*.*\*\// && !/$hdr_comment_start/) {
531		err("improper first line of block comment");
532	}
533
534	if ($in_comment) {	# still in comment, don't do further checks
535		$prev = $line;
536		next line;
537	}
538
539	if ((/[^(]\/\*\S/ || /^\/\*\S/) &&
540	    !(/$lint_re/ || ($splint_comments && /$splint_re/))) {
541		err("missing blank after open comment");
542	}
543	if (/\S\*\/[^)]|\S\*\/$/ &&
544	    !(/$lint_re/ || ($splint_comments && /$splint_re/))) {
545		err("missing blank before close comment");
546	}
547	if (/\/\/\S/) {		# C++ comments
548		err("missing blank after start comment");
549	}
550	# check for unterminated single line comments, but allow them when
551	# they are used to comment out the argument list of a function
552	# declaration.
553	if (/\S.*\/\*/ && !/\S.*\/\*.*\*\// && !/\(\/\*/) {
554		err("unterminated single line comment");
555	}
556
557	if (/^(#else|#endif|#include)(.*)$/) {
558		$prev = $line;
559		if ($picky) {
560			my $directive = $1;
561			my $clause = $2;
562			# Enforce ANSI rules for #else and #endif: no noncomment
563			# identifiers are allowed after #endif or #else.  Allow
564			# C++ comments since they seem to be a fact of life.
565			if ((($1 eq "#endif") || ($1 eq "#else")) &&
566			    ($clause ne "") &&
567			    (!($clause =~ /^\s+\/\*.*\*\/$/)) &&
568			    (!($clause =~ /^\s+\/\/.*$/))) {
569				err("non-comment text following " .
570				    "$directive (or malformed $directive " .
571				    "directive)");
572			}
573		}
574		next line;
575	}
576
577	#
578	# delete any comments and check everything else.  Note that
579	# ".*?" is a non-greedy match, so that we don't get confused by
580	# multiple comments on the same line.
581	#
582	s/\/\*.*?\*\///g;
583	s/\/\/.*$//;		# C++ comments
584
585	# delete any trailing whitespace; we have already checked for that.
586	s/\s*$//;
587
588	# following checks do not apply to text in comments.
589
590	if (/[^<>\s][!<>=]=/ || /[^<>][!<>=]=[^\s,]/ ||
591	    (/[^->]>[^,=>\s]/ && !/[^->]>$/) ||
592	    (/[^<]<[^,=<\s]/ && !/[^<]<$/) ||
593	    /[^<\s]<[^<]/ || /[^->\s]>[^>]/) {
594		err("missing space around relational operator");
595	}
596	if (/\S>>=/ || /\S<<=/ || />>=\S/ || /<<=\S/ || /\S[-+*\/&|^%]=/ ||
597	    (/[^-+*\/&|^%!<>=\s]=[^=]/ && !/[^-+*\/&|^%!<>=\s]=$/) ||
598	    (/[^!<>=]=[^=\s]/ && !/[^!<>=]=$/)) {
599		# XXX - should only check this for C++ code
600		# XXX - there are probably other forms that should be allowed
601		if (!/\soperator=/) {
602			err("missing space around assignment operator");
603		}
604	}
605	if (/[,;]\S/ && !/\bfor \(;;\)/) {
606		err("comma or semicolon followed by non-blank");
607	}
608	# allow "for" statements to have empty "while" clauses
609	if (/\s[,;]/ && !/^[\t]+;$/ && !/^\s*for \([^;]*; ;[^;]*\)/) {
610		err("comma or semicolon preceded by blank");
611	}
612	if (/^\s*(&&|\|\|)/) {
613		err("improper boolean continuation");
614	}
615	if (/\S   *(&&|\|\|)/ || /(&&|\|\|)   *\S/) {
616		err("more than one space around boolean operator");
617	}
618	if (/\b(for|if|while|switch|sizeof|return|case)\(/) {
619		err("missing space between keyword and paren");
620	}
621	if (/(\b(for|if|while|switch|return)\b.*){2,}/ && !/^#define/) {
622		# multiple "case" and "sizeof" allowed
623		err("more than one keyword on line");
624	}
625	if (/\b(for|if|while|switch|sizeof|return|case)\s\s+\(/ &&
626	    !/^#if\s+\(/) {
627		err("extra space between keyword and paren");
628	}
629	# try to detect "func (x)" but not "if (x)" or
630	# "#define foo (x)" or "int (*func)();"
631	if (/\w\s\(/) {
632		my $s = $_;
633		# strip off all keywords on the line
634		s/\b(for|if|while|switch|return|case|sizeof)\s\(/XXX(/g;
635		s/#elif\s\(/XXX(/g;
636		s/^#define\s+\w+\s+\(/XXX(/;
637		# do not match things like "void (*f)();"
638		# or "typedef void (func_t)();"
639		s/\w\s\(+\*/XXX(*/g;
640		s/\b($typename|void)\s+\(+/XXX(/og;
641		if (/\w\s\(/) {
642			err("extra space between function name and left paren");
643		}
644		$_ = $s;
645	}
646	# try to detect "int foo(x)", but not "extern int foo(x);"
647	# XXX - this still trips over too many legitimate things,
648	# like "int foo(x,\n\ty);"
649#		if (/^(\w+(\s|\*)+)+\w+\(/ && !/\)[;,](\s|)*$/ &&
650#		    !/^(extern|static)\b/) {
651#			err("return type of function not on separate line");
652#		}
653	# this is a close approximation
654	if (/^(\w+(\s|\*)+)+\w+\(.*\)(\s|)*$/ &&
655	    !/^(extern|static)\b/) {
656		err("return type of function not on separate line");
657	}
658	if (/^#define /) {
659		err("#define followed by space instead of tab");
660	}
661	if (/^\s*return\W[^;]*;/ && !/^\s*return\s*\(.*\);/) {
662		err("unparenthesized return expression");
663	}
664	if (/\bsizeof\b/ && !/\bsizeof\s*\(.*\)/) {
665		err("unparenthesized sizeof expression");
666	}
667	if (/\(\s/) {
668		err("whitespace after left paren");
669	}
670	# Allow "for" statements to have empty "continue" clauses.
671	# Allow right paren on its own line unless we're being picky (-p).
672	if (/\s\)/ && !/^\s*for \([^;]*;[^;]*; \)/ && ($picky || !/^\s*\)/)) {
673		err("whitespace before right paren");
674	}
675	if (/^\s*\(void\)[^ ]/) {
676		err("missing space after (void) cast");
677	}
678	if (/\S\{/ && !/\{\{/) {
679		err("missing space before left brace");
680	}
681	if ($in_function && /^\s+\{/ &&
682	    ($prev =~ /\)\s*$/ || $prev =~ /\bstruct\s+\w+$/)) {
683		err("left brace starting a line");
684	}
685	if (/\}(else|while)/) {
686		err("missing space after right brace");
687	}
688	if (/\}\s\s+(else|while)/) {
689		err("extra space after right brace");
690	}
691	if (/\b_VOID\b|\bVOID\b|\bSTATIC\b/) {
692		err("obsolete use of VOID or STATIC");
693	}
694	if (/\b$typename\*/o) {
695		err("missing space between type name and *");
696	}
697	if (/^\s+#/) {
698		err("preprocessor statement not in column 1");
699	}
700	if (/^#\s/) {
701		err("blank after preprocessor #");
702	}
703	if (/!\s*(strcmp|strncmp|bcmp)\s*\(/) {
704		err("don't use boolean ! with comparison functions");
705	}
706
707	#
708	# We completely ignore, for purposes of indentation:
709	#  * lines outside of functions
710	#  * preprocessor lines
711	#
712	if ($check_continuation && $in_function && !$in_cpp) {
713		process_indent($_);
714	}
715	if ($picky) {
716		# try to detect spaces after casts, but allow (e.g.)
717		# "sizeof (int) + 1", "void (*funcptr)(int) = foo;", and
718		# "int foo(int) __NORETURN;"
719		if ((/^\($typename( \*+)?\)\s/o ||
720		    /\W\($typename( \*+)?\)\s/o) &&
721		    !/sizeof\s*\($typename( \*)?\)\s/o &&
722		    !/\($typename( \*+)?\)\s+=[^=]/o) {
723			err("space after cast");
724		}
725		if (/\b$typename\s*\*\s/o &&
726		    !/\b$typename\s*\*\s+const\b/o) {
727			err("unary * followed by space");
728		}
729	}
730	if ($check_posix_types) {
731		# try to detect old non-POSIX types.
732		# POSIX requires all non-standard typedefs to end in _t,
733		# but historically these have been used.
734		if (/\b(unchar|ushort|uint|ulong|u_int|u_short|u_long|u_char|quad)\b/) {
735			err("non-POSIX typedef $1 used: use $old2posix{$1} instead");
736		}
737	}
738	if ($heuristic) {
739		# cannot check this everywhere due to "struct {\n...\n} foo;"
740		if ($in_function && !$in_declaration &&
741		    /\}./ && !/\}\s+=/ && !/\{.*\}[;,]$/ && !/\}(\s|)*$/ &&
742		    !/\} (else|while)/ && !/\}\}/) {
743			err("possible bad text following right brace");
744		}
745		# cannot check this because sub-blocks in
746		# the middle of code are ok
747		if ($in_function && /^\s+\{/) {
748			err("possible left brace starting a line");
749		}
750	}
751	if (/^\s*else\W/) {
752		if ($prev =~ /^\s*\}$/) {
753			err_prefix($prev,
754			    "else and right brace should be on same line");
755		}
756	}
757	$prev = $line;
758}
759
760if ($prev eq "") {
761	err("last line in file is blank");
762}
763
764}
765
766#
767# Continuation-line checking
768#
769# The rest of this file contains the code for the continuation checking
770# engine.  It's a pretty simple state machine which tracks the expression
771# depth (unmatched '('s and '['s).
772#
773# Keep in mind that the argument to process_indent() has already been heavily
774# processed; all comments have been replaced by control-A, and the contents of
775# strings and character constants have been elided.
776#
777
778my $cont_in;		# currently inside of a continuation
779my $cont_off;		# skipping an initializer or definition
780my $cont_noerr;		# suppress cascading errors
781my $cont_start;		# the line being continued
782my $cont_base;		# the base indentation
783my $cont_first;		# this is the first line of a statement
784my $cont_multiseg;	# this continuation has multiple segments
785
786my $cont_special;	# this is a C statement (if, for, etc.)
787my $cont_macro;		# this is a macro
788my $cont_case;		# this is a multi-line case
789
790my @cont_paren;		# the stack of unmatched ( and [s we've seen
791
792sub
793reset_indent()
794{
795	$cont_in = 0;
796	$cont_off = 0;
797}
798
799sub
800delabel($)
801{
802	#
803	# replace labels with tabs.  Note that there may be multiple
804	# labels on a line.
805	#
806	local $_ = $_[0];
807
808	while (/^(\t*)( *(?:(?:\w+\s*)|(?:case\b[^:]*)): *)(.*)$/) {
809		my ($pre_tabs, $label, $rest) = ($1, $2, $3);
810		$_ = $pre_tabs;
811		while ($label =~ s/^([^\t]*)(\t+)//) {
812			$_ .= "\t" x (length($2) + length($1) / 8);
813		}
814		$_ .= ("\t" x (length($label) / 8)).$rest;
815	}
816
817	return ($_);
818}
819
820sub
821process_indent($)
822{
823	require strict;
824	local $_ = $_[0];			# preserve the global $_
825
826	s///g;	# No comments
827	s/\s+$//;	# Strip trailing whitespace
828
829	return			if (/^$/);	# skip empty lines
830
831	# regexps used below; keywords taking (), macros, and continued cases
832	my $special = '(?:(?:\}\s*)?else\s+)?(?:if|for|while|switch)\b';
833	my $macro = '[A-Z_][A-Z_0-9]*\(';
834	my $case = 'case\b[^:]*$';
835
836	# skip over enumerations, array definitions, initializers, etc.
837	if ($cont_off <= 0 && !/^\s*$special/ &&
838	    (/(?:(?:\b(?:enum|struct|union)\s*[^\{]*)|(?:\s+=\s*))\{/ ||
839	    (/^\s*\{/ && $prev =~ /=\s*(?:\/\*.*\*\/\s*)*$/))) {
840		$cont_in = 0;
841		$cont_off = tr/{/{/ - tr/}/}/;
842		return;
843	}
844	if ($cont_off) {
845		$cont_off += tr/{/{/ - tr/}/}/;
846		return;
847	}
848
849	if (!$cont_in) {
850		$cont_start = $line;
851
852		if (/^\t* /) {
853			err("non-continuation indented 4 spaces");
854			$cont_noerr = 1;		# stop reporting
855		}
856		$_ = delabel($_);	# replace labels with tabs
857
858		# check if the statement is complete
859		return		if (/^\s*\}?$/);
860		return		if (/^\s*\}?\s*else\s*\{?$/);
861		return		if (/^\s*do\s*\{?$/);
862		return		if (/\{$/);
863		return		if (/\}[,;]?$/);
864
865		# Allow macros on their own lines
866		return		if (/^\s*[A-Z_][A-Z_0-9]*$/);
867
868		# cases we don't deal with, generally non-kosher
869		if (/\{/) {
870			err("stuff after {");
871			return;
872		}
873
874		# Get the base line, and set up the state machine
875		/^(\t*)/;
876		$cont_base = $1;
877		$cont_in = 1;
878		@cont_paren = ();
879		$cont_first = 1;
880		$cont_multiseg = 0;
881
882		# certain things need special processing
883		$cont_special = /^\s*$special/? 1 : 0;
884		$cont_macro = /^\s*$macro/? 1 : 0;
885		$cont_case = /^\s*$case/? 1 : 0;
886	} else {
887		$cont_first = 0;
888
889		# Strings may be pulled back to an earlier (half-)tabstop
890		unless ($cont_noerr || /^$cont_base    / ||
891		    (/^\t*(?:    )?(?:gettext\()?\"/ && !/^$cont_base\t/)) {
892			err_prefix($cont_start,
893			    "continuation should be indented 4 spaces");
894		}
895	}
896
897	my $rest = $_;			# keeps the remainder of the line
898
899	#
900	# The split matches 0 characters, so that each 'special' character
901	# is processed separately.  Parens and brackets are pushed and
902	# popped off the @cont_paren stack.  For normal processing, we wait
903	# until a ; or { terminates the statement.  "special" processing
904	# (if/for/while/switch) is allowed to stop when the stack empties,
905	# as is macro processing.  Case statements are terminated with a :
906	# and an empty paren stack.
907	#
908	foreach $_ (split /[^\(\)\[\]\{\}\;\:]*/) {
909		next		if (length($_) == 0);
910
911		# rest contains the remainder of the line
912		my $rxp = "[^\Q$_\E]*\Q$_\E";
913		$rest =~ s/^$rxp//;
914
915		if (/\(/ || /\[/) {
916			push @cont_paren, $_;
917		} elsif (/\)/ || /\]/) {
918			my $cur = $_;
919			tr/\)\]/\(\[/;
920
921			my $old = (pop @cont_paren);
922			if (!defined($old)) {
923				err("unexpected '$cur'");
924				$cont_in = 0;
925				last;
926			} elsif ($old ne $_) {
927				err("'$cur' mismatched with '$old'");
928				$cont_in = 0;
929				last;
930			}
931
932			#
933			# If the stack is now empty, do special processing
934			# for if/for/while/switch and macro statements.
935			#
936			next		if (@cont_paren != 0);
937			if ($cont_special) {
938				if ($rest =~ /^\s*\{?$/) {
939					$cont_in = 0;
940					last;
941				}
942				if ($rest =~ /^\s*;$/) {
943					err("empty if/for/while body ".
944					    "not on its own line");
945					$cont_in = 0;
946					last;
947				}
948				if (!$cont_first && $cont_multiseg == 1) {
949					err_prefix($cont_start,
950					    "multiple statements continued ".
951					    "over multiple lines");
952					$cont_multiseg = 2;
953				} elsif ($cont_multiseg == 0) {
954					$cont_multiseg = 1;
955				}
956				# We've finished this section, start
957				# processing the next.
958				goto section_ended;
959			}
960			if ($cont_macro) {
961				if ($rest =~ /^$/) {
962					$cont_in = 0;
963					last;
964				}
965			}
966		} elsif (/\;/) {
967			if ($cont_case) {
968				err("unexpected ;");
969			} elsif (!$cont_special) {
970				err("unexpected ;")	if (@cont_paren != 0);
971				if (!$cont_first && $cont_multiseg == 1) {
972					err_prefix($cont_start,
973					    "multiple statements continued ".
974					    "over multiple lines");
975					$cont_multiseg = 2;
976				} elsif ($cont_multiseg == 0) {
977					$cont_multiseg = 1;
978				}
979				if ($rest =~ /^$/) {
980					$cont_in = 0;
981					last;
982				}
983				if ($rest =~ /^\s*special/) {
984					err("if/for/while/switch not started ".
985					    "on its own line");
986				}
987				goto section_ended;
988			}
989		} elsif (/\{/) {
990			err("{ while in parens/brackets") if (@cont_paren != 0);
991			err("stuff after {")		if ($rest =~ /[^\s}]/);
992			$cont_in = 0;
993			last;
994		} elsif (/\}/) {
995			err("} while in parens/brackets") if (@cont_paren != 0);
996			if (!$cont_special && $rest !~ /^\s*(while|else)\b/) {
997				if ($rest =~ /^$/) {
998					err("unexpected }");
999				} else {
1000					err("stuff after }");
1001				}
1002				$cont_in = 0;
1003				last;
1004			}
1005		} elsif (/\:/ && $cont_case && @cont_paren == 0) {
1006			err("stuff after multi-line case") if ($rest !~ /$^/);
1007			$cont_in = 0;
1008			last;
1009		}
1010		next;
1011section_ended:
1012		# End of a statement or if/while/for loop.  Reset
1013		# cont_special and cont_macro based on the rest of the
1014		# line.
1015		$cont_special = ($rest =~ /^\s*$special/)? 1 : 0;
1016		$cont_macro = ($rest =~ /^\s*$macro/)? 1 : 0;
1017		$cont_case = 0;
1018		next;
1019	}
1020	$cont_noerr = 0			if (!$cont_in);
1021}
1022