xref: /freebsd/sys/contrib/openzfs/scripts/cstyle.pl (revision 43a5ec4eb41567cc92586503212743d89686d78f)
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	ARGSUSED[0-9]*|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
389	# is this the beginning or ending of a function?
390	# (not if "struct foo\n{\n")
391	if (/^\{$/ && $prev =~ /\)\s*(const\s*)?(\/\*.*\*\/\s*)?\\?$/) {
392		$in_function = 1;
393		$in_declaration = 1;
394		$in_function_header = 0;
395		$function_header_full_indent = 0;
396		$prev = $line;
397		next line;
398	}
399	if (/^\}\s*(\/\*.*\*\/\s*)*$/) {
400		if ($prev =~ /^\s*return\s*;/) {
401			err_prev("unneeded return at end of function");
402		}
403		$in_function = 0;
404		reset_indent();		# we don't check between functions
405		$prev = $line;
406		next line;
407	}
408	if ($in_function_header && ! /^    (\w|\.)/ ) {
409		if (/^\{\}$/ # empty functions
410		|| /;/ #run function with multiline arguments
411		|| /#/ #preprocessor commands
412		|| /^[^\s\\]*\(.*\)$/ #functions without ; at the end
413		|| /^$/ #function declaration can't have empty line
414		) {
415			$in_function_header = 0;
416			$function_header_full_indent = 0;
417		} elsif ($prev =~ /^__attribute__/) { #__attribute__((*))
418			$in_function_header = 0;
419			$function_header_full_indent = 0;
420			$prev = $line;
421			next line;
422		} elsif ($picky	&& ! (/^\t/ && $function_header_full_indent != 0)) {
423
424			err("continuation line should be indented by 4 spaces");
425		}
426	}
427
428	#
429	# If this matches something of form "foo(", it's probably a function
430	# definition, unless it ends with ") bar;", in which case it's a declaration
431	# that uses a macro to generate the type.
432	#
433	if (/^\w+\(/ && !/\) \w+;/) {
434		$in_function_header = 1;
435		if (/\($/) {
436			$function_header_full_indent = 1;
437		}
438	}
439	if ($in_function_header && /^\{$/) {
440		$in_function_header = 0;
441		$function_header_full_indent = 0;
442		$in_function = 1;
443	}
444	if ($in_function_header && /\);$/) {
445		$in_function_header = 0;
446		$function_header_full_indent = 0;
447	}
448	if ($in_function_header && /\{$/ ) {
449		if ($picky) {
450			err("opening brace on same line as function header");
451		}
452		$in_function_header = 0;
453		$function_header_full_indent = 0;
454		$in_function = 1;
455		next line;
456	}
457
458	if ($in_warlock_comment && /\*\//) {
459		$in_warlock_comment = 0;
460		$prev = $line;
461		next line;
462	}
463
464	# a blank line terminates the declarations within a function.
465	# XXX - but still a problem in sub-blocks.
466	if ($in_declaration && /^$/) {
467		$in_declaration = 0;
468	}
469
470	if ($comment_done) {
471		$in_comment = 0;
472		$in_header_comment = 0;
473		$comment_done = 0;
474	}
475	# does this looks like the start of a block comment?
476	if (/$hdr_comment_start/) {
477		if (!/^\t*\/\*/) {
478			err("block comment not indented by tabs");
479		}
480		$in_comment = 1;
481		/^(\s*)\//;
482		$comment_prefix = $1;
483		if ($comment_prefix eq "") {
484			$in_header_comment = 1;
485		}
486		$prev = $line;
487		next line;
488	}
489	# are we still in the block comment?
490	if ($in_comment) {
491		if (/^$comment_prefix \*\/$/) {
492			$comment_done = 1;
493		} elsif (/\*\//) {
494			$comment_done = 1;
495			err("improper block comment close")
496			    unless ($ignore_hdr_comment && $in_header_comment);
497		} elsif (!/^$comment_prefix \*[ \t]/ &&
498		    !/^$comment_prefix \*$/) {
499			err("improper block comment")
500			    unless ($ignore_hdr_comment && $in_header_comment);
501		}
502	}
503
504	if ($in_header_comment && $ignore_hdr_comment) {
505		$prev = $line;
506		next line;
507	}
508
509	# check for errors that might occur in comments and in code.
510
511	# allow spaces to be used to draw pictures in all comments.
512	if (/[^ ]     / && !/".*     .*"/ && !$in_comment) {
513		err("spaces instead of tabs");
514	}
515	if (/^ / && !/^ \*[ \t\/]/ && !/^ \*$/ &&
516	    (!/^    (\w|\.)/ || $in_function != 0)) {
517		err("indent by spaces instead of tabs");
518	}
519	if (/^\t+ [^ \t\*]/ || /^\t+  \S/ || /^\t+   \S/) {
520		err("continuation line not indented by 4 spaces");
521	}
522	if (/$warlock_re/ && !/\*\//) {
523		$in_warlock_comment = 1;
524		$prev = $line;
525		next line;
526	}
527	if (/^\s*\/\*./ && !/^\s*\/\*.*\*\// && !/$hdr_comment_start/) {
528		err("improper first line of block comment");
529	}
530
531	if ($in_comment) {	# still in comment, don't do further checks
532		$prev = $line;
533		next line;
534	}
535
536	if ((/[^(]\/\*\S/ || /^\/\*\S/) &&
537	    !(/$lint_re/ || ($splint_comments && /$splint_re/))) {
538		err("missing blank after open comment");
539	}
540	if (/\S\*\/[^)]|\S\*\/$/ &&
541	    !(/$lint_re/ || ($splint_comments && /$splint_re/))) {
542		err("missing blank before close comment");
543	}
544	if (/\/\/\S/) {		# C++ comments
545		err("missing blank after start comment");
546	}
547	# check for unterminated single line comments, but allow them when
548	# they are used to comment out the argument list of a function
549	# declaration.
550	if (/\S.*\/\*/ && !/\S.*\/\*.*\*\// && !/\(\/\*/) {
551		err("unterminated single line comment");
552	}
553
554	if (/^(#else|#endif|#include)(.*)$/) {
555		$prev = $line;
556		if ($picky) {
557			my $directive = $1;
558			my $clause = $2;
559			# Enforce ANSI rules for #else and #endif: no noncomment
560			# identifiers are allowed after #endif or #else.  Allow
561			# C++ comments since they seem to be a fact of life.
562			if ((($1 eq "#endif") || ($1 eq "#else")) &&
563			    ($clause ne "") &&
564			    (!($clause =~ /^\s+\/\*.*\*\/$/)) &&
565			    (!($clause =~ /^\s+\/\/.*$/))) {
566				err("non-comment text following " .
567				    "$directive (or malformed $directive " .
568				    "directive)");
569			}
570		}
571		next line;
572	}
573
574	#
575	# delete any comments and check everything else.  Note that
576	# ".*?" is a non-greedy match, so that we don't get confused by
577	# multiple comments on the same line.
578	#
579	s/\/\*.*?\*\///g;
580	s/\/\/.*$//;		# C++ comments
581
582	# delete any trailing whitespace; we have already checked for that.
583	s/\s*$//;
584
585	# following checks do not apply to text in comments.
586
587	if (/[^<>\s][!<>=]=/ || /[^<>][!<>=]=[^\s,]/ ||
588	    (/[^->]>[^,=>\s]/ && !/[^->]>$/) ||
589	    (/[^<]<[^,=<\s]/ && !/[^<]<$/) ||
590	    /[^<\s]<[^<]/ || /[^->\s]>[^>]/) {
591		err("missing space around relational operator");
592	}
593	if (/\S>>=/ || /\S<<=/ || />>=\S/ || /<<=\S/ || /\S[-+*\/&|^%]=/ ||
594	    (/[^-+*\/&|^%!<>=\s]=[^=]/ && !/[^-+*\/&|^%!<>=\s]=$/) ||
595	    (/[^!<>=]=[^=\s]/ && !/[^!<>=]=$/)) {
596		# XXX - should only check this for C++ code
597		# XXX - there are probably other forms that should be allowed
598		if (!/\soperator=/) {
599			err("missing space around assignment operator");
600		}
601	}
602	if (/[,;]\S/ && !/\bfor \(;;\)/) {
603		err("comma or semicolon followed by non-blank");
604	}
605	# allow "for" statements to have empty "while" clauses
606	if (/\s[,;]/ && !/^[\t]+;$/ && !/^\s*for \([^;]*; ;[^;]*\)/) {
607		err("comma or semicolon preceded by blank");
608	}
609	if (/^\s*(&&|\|\|)/) {
610		err("improper boolean continuation");
611	}
612	if (/\S   *(&&|\|\|)/ || /(&&|\|\|)   *\S/) {
613		err("more than one space around boolean operator");
614	}
615	if (/\b(for|if|while|switch|sizeof|return|case)\(/) {
616		err("missing space between keyword and paren");
617	}
618	if (/(\b(for|if|while|switch|return)\b.*){2,}/ && !/^#define/) {
619		# multiple "case" and "sizeof" allowed
620		err("more than one keyword on line");
621	}
622	if (/\b(for|if|while|switch|sizeof|return|case)\s\s+\(/ &&
623	    !/^#if\s+\(/) {
624		err("extra space between keyword and paren");
625	}
626	# try to detect "func (x)" but not "if (x)" or
627	# "#define foo (x)" or "int (*func)();"
628	if (/\w\s\(/) {
629		my $s = $_;
630		# strip off all keywords on the line
631		s/\b(for|if|while|switch|return|case|sizeof)\s\(/XXX(/g;
632		s/#elif\s\(/XXX(/g;
633		s/^#define\s+\w+\s+\(/XXX(/;
634		# do not match things like "void (*f)();"
635		# or "typedef void (func_t)();"
636		s/\w\s\(+\*/XXX(*/g;
637		s/\b($typename|void)\s+\(+/XXX(/og;
638		if (/\w\s\(/) {
639			err("extra space between function name and left paren");
640		}
641		$_ = $s;
642	}
643	# try to detect "int foo(x)", but not "extern int foo(x);"
644	# XXX - this still trips over too many legitimate things,
645	# like "int foo(x,\n\ty);"
646#		if (/^(\w+(\s|\*)+)+\w+\(/ && !/\)[;,](\s|)*$/ &&
647#		    !/^(extern|static)\b/) {
648#			err("return type of function not on separate line");
649#		}
650	# this is a close approximation
651	if (/^(\w+(\s|\*)+)+\w+\(.*\)(\s|)*$/ &&
652	    !/^(extern|static)\b/) {
653		err("return type of function not on separate line");
654	}
655	if (/^#define /) {
656		err("#define followed by space instead of tab");
657	}
658	if (/^\s*return\W[^;]*;/ && !/^\s*return\s*\(.*\);/) {
659		err("unparenthesized return expression");
660	}
661	if (/\bsizeof\b/ && !/\bsizeof\s*\(.*\)/) {
662		err("unparenthesized sizeof expression");
663	}
664	if (/\(\s/) {
665		err("whitespace after left paren");
666	}
667	# Allow "for" statements to have empty "continue" clauses.
668	# Allow right paren on its own line unless we're being picky (-p).
669	if (/\s\)/ && !/^\s*for \([^;]*;[^;]*; \)/ && ($picky || !/^\s*\)/)) {
670		err("whitespace before right paren");
671	}
672	if (/^\s*\(void\)[^ ]/) {
673		err("missing space after (void) cast");
674	}
675	if (/\S\{/ && !/\{\{/) {
676		err("missing space before left brace");
677	}
678	if ($in_function && /^\s+\{/ &&
679	    ($prev =~ /\)\s*$/ || $prev =~ /\bstruct\s+\w+$/)) {
680		err("left brace starting a line");
681	}
682	if (/\}(else|while)/) {
683		err("missing space after right brace");
684	}
685	if (/\}\s\s+(else|while)/) {
686		err("extra space after right brace");
687	}
688	if (/\b_VOID\b|\bVOID\b|\bSTATIC\b/) {
689		err("obsolete use of VOID or STATIC");
690	}
691	if (/\b$typename\*/o) {
692		err("missing space between type name and *");
693	}
694	if (/^\s+#/) {
695		err("preprocessor statement not in column 1");
696	}
697	if (/^#\s/) {
698		err("blank after preprocessor #");
699	}
700	if (/!\s*(strcmp|strncmp|bcmp)\s*\(/) {
701		err("don't use boolean ! with comparison functions");
702	}
703
704	#
705	# We completely ignore, for purposes of indentation:
706	#  * lines outside of functions
707	#  * preprocessor lines
708	#
709	if ($check_continuation && $in_function && !$in_cpp) {
710		process_indent($_);
711	}
712	if ($picky) {
713		# try to detect spaces after casts, but allow (e.g.)
714		# "sizeof (int) + 1", "void (*funcptr)(int) = foo;", and
715		# "int foo(int) __NORETURN;"
716		if ((/^\($typename( \*+)?\)\s/o ||
717		    /\W\($typename( \*+)?\)\s/o) &&
718		    !/sizeof\s*\($typename( \*)?\)\s/o &&
719		    !/\($typename( \*+)?\)\s+=[^=]/o) {
720			err("space after cast");
721		}
722		if (/\b$typename\s*\*\s/o &&
723		    !/\b$typename\s*\*\s+const\b/o) {
724			err("unary * followed by space");
725		}
726	}
727	if ($check_posix_types) {
728		# try to detect old non-POSIX types.
729		# POSIX requires all non-standard typedefs to end in _t,
730		# but historically these have been used.
731		if (/\b(unchar|ushort|uint|ulong|u_int|u_short|u_long|u_char|quad)\b/) {
732			err("non-POSIX typedef $1 used: use $old2posix{$1} instead");
733		}
734	}
735	if ($heuristic) {
736		# cannot check this everywhere due to "struct {\n...\n} foo;"
737		if ($in_function && !$in_declaration &&
738		    /\}./ && !/\}\s+=/ && !/\{.*\}[;,]$/ && !/\}(\s|)*$/ &&
739		    !/\} (else|while)/ && !/\}\}/) {
740			err("possible bad text following right brace");
741		}
742		# cannot check this because sub-blocks in
743		# the middle of code are ok
744		if ($in_function && /^\s+\{/) {
745			err("possible left brace starting a line");
746		}
747	}
748	if (/^\s*else\W/) {
749		if ($prev =~ /^\s*\}$/) {
750			err_prefix($prev,
751			    "else and right brace should be on same line");
752		}
753	}
754	$prev = $line;
755}
756
757if ($prev eq "") {
758	err("last line in file is blank");
759}
760
761}
762
763#
764# Continuation-line checking
765#
766# The rest of this file contains the code for the continuation checking
767# engine.  It's a pretty simple state machine which tracks the expression
768# depth (unmatched '('s and '['s).
769#
770# Keep in mind that the argument to process_indent() has already been heavily
771# processed; all comments have been replaced by control-A, and the contents of
772# strings and character constants have been elided.
773#
774
775my $cont_in;		# currently inside of a continuation
776my $cont_off;		# skipping an initializer or definition
777my $cont_noerr;		# suppress cascading errors
778my $cont_start;		# the line being continued
779my $cont_base;		# the base indentation
780my $cont_first;		# this is the first line of a statement
781my $cont_multiseg;	# this continuation has multiple segments
782
783my $cont_special;	# this is a C statement (if, for, etc.)
784my $cont_macro;		# this is a macro
785my $cont_case;		# this is a multi-line case
786
787my @cont_paren;		# the stack of unmatched ( and [s we've seen
788
789sub
790reset_indent()
791{
792	$cont_in = 0;
793	$cont_off = 0;
794}
795
796sub
797delabel($)
798{
799	#
800	# replace labels with tabs.  Note that there may be multiple
801	# labels on a line.
802	#
803	local $_ = $_[0];
804
805	while (/^(\t*)( *(?:(?:\w+\s*)|(?:case\b[^:]*)): *)(.*)$/) {
806		my ($pre_tabs, $label, $rest) = ($1, $2, $3);
807		$_ = $pre_tabs;
808		while ($label =~ s/^([^\t]*)(\t+)//) {
809			$_ .= "\t" x (length($2) + length($1) / 8);
810		}
811		$_ .= ("\t" x (length($label) / 8)).$rest;
812	}
813
814	return ($_);
815}
816
817sub
818process_indent($)
819{
820	require strict;
821	local $_ = $_[0];			# preserve the global $_
822
823	s///g;	# No comments
824	s/\s+$//;	# Strip trailing whitespace
825
826	return			if (/^$/);	# skip empty lines
827
828	# regexps used below; keywords taking (), macros, and continued cases
829	my $special = '(?:(?:\}\s*)?else\s+)?(?:if|for|while|switch)\b';
830	my $macro = '[A-Z_][A-Z_0-9]*\(';
831	my $case = 'case\b[^:]*$';
832
833	# skip over enumerations, array definitions, initializers, etc.
834	if ($cont_off <= 0 && !/^\s*$special/ &&
835	    (/(?:(?:\b(?:enum|struct|union)\s*[^\{]*)|(?:\s+=\s*))\{/ ||
836	    (/^\s*\{/ && $prev =~ /=\s*(?:\/\*.*\*\/\s*)*$/))) {
837		$cont_in = 0;
838		$cont_off = tr/{/{/ - tr/}/}/;
839		return;
840	}
841	if ($cont_off) {
842		$cont_off += tr/{/{/ - tr/}/}/;
843		return;
844	}
845
846	if (!$cont_in) {
847		$cont_start = $line;
848
849		if (/^\t* /) {
850			err("non-continuation indented 4 spaces");
851			$cont_noerr = 1;		# stop reporting
852		}
853		$_ = delabel($_);	# replace labels with tabs
854
855		# check if the statement is complete
856		return		if (/^\s*\}?$/);
857		return		if (/^\s*\}?\s*else\s*\{?$/);
858		return		if (/^\s*do\s*\{?$/);
859		return		if (/\{$/);
860		return		if (/\}[,;]?$/);
861
862		# Allow macros on their own lines
863		return		if (/^\s*[A-Z_][A-Z_0-9]*$/);
864
865		# cases we don't deal with, generally non-kosher
866		if (/\{/) {
867			err("stuff after {");
868			return;
869		}
870
871		# Get the base line, and set up the state machine
872		/^(\t*)/;
873		$cont_base = $1;
874		$cont_in = 1;
875		@cont_paren = ();
876		$cont_first = 1;
877		$cont_multiseg = 0;
878
879		# certain things need special processing
880		$cont_special = /^\s*$special/? 1 : 0;
881		$cont_macro = /^\s*$macro/? 1 : 0;
882		$cont_case = /^\s*$case/? 1 : 0;
883	} else {
884		$cont_first = 0;
885
886		# Strings may be pulled back to an earlier (half-)tabstop
887		unless ($cont_noerr || /^$cont_base    / ||
888		    (/^\t*(?:    )?(?:gettext\()?\"/ && !/^$cont_base\t/)) {
889			err_prefix($cont_start,
890			    "continuation should be indented 4 spaces");
891		}
892	}
893
894	my $rest = $_;			# keeps the remainder of the line
895
896	#
897	# The split matches 0 characters, so that each 'special' character
898	# is processed separately.  Parens and brackets are pushed and
899	# popped off the @cont_paren stack.  For normal processing, we wait
900	# until a ; or { terminates the statement.  "special" processing
901	# (if/for/while/switch) is allowed to stop when the stack empties,
902	# as is macro processing.  Case statements are terminated with a :
903	# and an empty paren stack.
904	#
905	foreach $_ (split /[^\(\)\[\]\{\}\;\:]*/) {
906		next		if (length($_) == 0);
907
908		# rest contains the remainder of the line
909		my $rxp = "[^\Q$_\E]*\Q$_\E";
910		$rest =~ s/^$rxp//;
911
912		if (/\(/ || /\[/) {
913			push @cont_paren, $_;
914		} elsif (/\)/ || /\]/) {
915			my $cur = $_;
916			tr/\)\]/\(\[/;
917
918			my $old = (pop @cont_paren);
919			if (!defined($old)) {
920				err("unexpected '$cur'");
921				$cont_in = 0;
922				last;
923			} elsif ($old ne $_) {
924				err("'$cur' mismatched with '$old'");
925				$cont_in = 0;
926				last;
927			}
928
929			#
930			# If the stack is now empty, do special processing
931			# for if/for/while/switch and macro statements.
932			#
933			next		if (@cont_paren != 0);
934			if ($cont_special) {
935				if ($rest =~ /^\s*\{?$/) {
936					$cont_in = 0;
937					last;
938				}
939				if ($rest =~ /^\s*;$/) {
940					err("empty if/for/while body ".
941					    "not on its own line");
942					$cont_in = 0;
943					last;
944				}
945				if (!$cont_first && $cont_multiseg == 1) {
946					err_prefix($cont_start,
947					    "multiple statements continued ".
948					    "over multiple lines");
949					$cont_multiseg = 2;
950				} elsif ($cont_multiseg == 0) {
951					$cont_multiseg = 1;
952				}
953				# We've finished this section, start
954				# processing the next.
955				goto section_ended;
956			}
957			if ($cont_macro) {
958				if ($rest =~ /^$/) {
959					$cont_in = 0;
960					last;
961				}
962			}
963		} elsif (/\;/) {
964			if ($cont_case) {
965				err("unexpected ;");
966			} elsif (!$cont_special) {
967				err("unexpected ;")	if (@cont_paren != 0);
968				if (!$cont_first && $cont_multiseg == 1) {
969					err_prefix($cont_start,
970					    "multiple statements continued ".
971					    "over multiple lines");
972					$cont_multiseg = 2;
973				} elsif ($cont_multiseg == 0) {
974					$cont_multiseg = 1;
975				}
976				if ($rest =~ /^$/) {
977					$cont_in = 0;
978					last;
979				}
980				if ($rest =~ /^\s*special/) {
981					err("if/for/while/switch not started ".
982					    "on its own line");
983				}
984				goto section_ended;
985			}
986		} elsif (/\{/) {
987			err("{ while in parens/brackets") if (@cont_paren != 0);
988			err("stuff after {")		if ($rest =~ /[^\s}]/);
989			$cont_in = 0;
990			last;
991		} elsif (/\}/) {
992			err("} while in parens/brackets") if (@cont_paren != 0);
993			if (!$cont_special && $rest !~ /^\s*(while|else)\b/) {
994				if ($rest =~ /^$/) {
995					err("unexpected }");
996				} else {
997					err("stuff after }");
998				}
999				$cont_in = 0;
1000				last;
1001			}
1002		} elsif (/\:/ && $cont_case && @cont_paren == 0) {
1003			err("stuff after multi-line case") if ($rest !~ /$^/);
1004			$cont_in = 0;
1005			last;
1006		}
1007		next;
1008section_ended:
1009		# End of a statement or if/while/for loop.  Reset
1010		# cont_special and cont_macro based on the rest of the
1011		# line.
1012		$cont_special = ($rest =~ /^\s*$special/)? 1 : 0;
1013		$cont_macro = ($rest =~ /^\s*$macro/)? 1 : 0;
1014		$cont_case = 0;
1015		next;
1016	}
1017	$cont_noerr = 0			if (!$cont_in);
1018}
1019