xref: /freebsd/sys/contrib/openzfs/scripts/cstyle.pl (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 https://opensource.org/licenses/CDDL-1.0.
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 [-cgpvP] file...
62	-c	check continuation indentation inside functions
63	-g	print github actions' workflow commands
64	-p	perform some of the more picky checks
65	-v	verbose
66	-P	check for use of non-POSIX types
67";
68
69my %opts;
70
71if (!getopts("cghpvCP", \%opts)) {
72	print $usage;
73	exit 2;
74}
75
76my $check_continuation = $opts{'c'};
77my $github_workflow = $opts{'g'} || $ENV{'CI'};
78my $picky = $opts{'p'};
79my $verbose = $opts{'v'};
80my $check_posix_types = $opts{'P'};
81
82my ($filename, $line, $prev);		# shared globals
83
84my $fmt;
85my $hdr_comment_start;
86
87if ($verbose) {
88	$fmt = "%s: %d: %s\n%s\n";
89} else {
90	$fmt = "%s: %d: %s\n";
91}
92
93$hdr_comment_start = qr/^\s*\/\*$/;
94
95# Note, following must be in single quotes so that \s and \w work right.
96my $typename = '(int|char|short|long|unsigned|float|double' .
97    '|\w+_t|struct\s+\w+|union\s+\w+|FILE)';
98
99# mapping of old types to POSIX compatible types
100my %old2posix = (
101	'unchar' => 'uchar_t',
102	'ushort' => 'ushort_t',
103	'uint' => 'uint_t',
104	'ulong' => 'ulong_t',
105	'u_int' => 'uint_t',
106	'u_short' => 'ushort_t',
107	'u_long' => 'ulong_t',
108	'u_char' => 'uchar_t',
109	'quad' => 'quad_t'
110);
111
112my $lint_re = qr/\/\*(?:
113	NOTREACHED|LINTLIBRARY|VARARGS[0-9]*|
114	CONSTCOND|CONSTANTCOND|CONSTANTCONDITION|EMPTY|
115	FALLTHRU|FALLTHROUGH|LINTED.*?|PRINTFLIKE[0-9]*|
116	PROTOLIB[0-9]*|SCANFLIKE[0-9]*|CSTYLED.*?
117    )\*\//x;
118
119my $warlock_re = qr/\/\*\s*(?:
120	VARIABLES\ PROTECTED\ BY|
121	MEMBERS\ PROTECTED\ BY|
122	ALL\ MEMBERS\ PROTECTED\ BY|
123	READ-ONLY\ VARIABLES:|
124	READ-ONLY\ MEMBERS:|
125	VARIABLES\ READABLE\ WITHOUT\ LOCK:|
126	MEMBERS\ READABLE\ WITHOUT\ LOCK:|
127	LOCKS\ COVERED\ BY|
128	LOCK\ UNNEEDED\ BECAUSE|
129	LOCK\ NEEDED:|
130	LOCK\ HELD\ ON\ ENTRY:|
131	READ\ LOCK\ HELD\ ON\ ENTRY:|
132	WRITE\ LOCK\ HELD\ ON\ ENTRY:|
133	LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
134	READ\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
135	WRITE\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
136	LOCK\ RELEASED\ AS\ SIDE\ EFFECT:|
137	LOCK\ UPGRADED\ AS\ SIDE\ EFFECT:|
138	LOCK\ DOWNGRADED\ AS\ SIDE\ EFFECT:|
139	FUNCTIONS\ CALLED\ THROUGH\ POINTER|
140	FUNCTIONS\ CALLED\ THROUGH\ MEMBER|
141	LOCK\ ORDER:
142    )/x;
143
144my $err_stat = 0;		# exit status
145
146if ($#ARGV >= 0) {
147	foreach my $arg (@ARGV) {
148		my $fh = new IO::File $arg, "r";
149		if (!defined($fh)) {
150			printf "%s: can not open\n", $arg;
151		} else {
152			&cstyle($arg, $fh);
153			close $fh;
154		}
155	}
156} else {
157	&cstyle("<stdin>", *STDIN);
158}
159exit $err_stat;
160
161my $no_errs = 0;		# set for CSTYLED-protected lines
162
163sub err($) {
164	my ($error) = @_;
165	unless ($no_errs) {
166		if ($verbose) {
167			printf $fmt, $filename, $., $error, $line;
168		} else {
169			printf $fmt, $filename, $., $error;
170		}
171		if ($github_workflow) {
172			printf "::error file=%s,line=%s::%s\n", $filename, $., $error;
173		}
174		$err_stat = 1;
175	}
176}
177
178sub err_prefix($$) {
179	my ($prevline, $error) = @_;
180	my $out = $prevline."\n".$line;
181	unless ($no_errs) {
182		if ($verbose) {
183			printf $fmt, $filename, $., $error, $out;
184		} else {
185			printf $fmt, $filename, $., $error;
186		}
187		$err_stat = 1;
188	}
189}
190
191sub err_prev($) {
192	my ($error) = @_;
193	unless ($no_errs) {
194		if ($verbose) {
195			printf $fmt, $filename, $. - 1, $error, $prev;
196		} else {
197			printf $fmt, $filename, $. - 1, $error;
198		}
199		$err_stat = 1;
200	}
201}
202
203sub cstyle($$) {
204
205my ($fn, $filehandle) = @_;
206$filename = $fn;			# share it globally
207
208my $in_cpp = 0;
209my $next_in_cpp = 0;
210
211my $in_comment = 0;
212my $comment_done = 0;
213my $in_warlock_comment = 0;
214my $in_function = 0;
215my $in_function_header = 0;
216my $function_header_full_indent = 0;
217my $in_declaration = 0;
218my $note_level = 0;
219my $nextok = 0;
220my $nocheck = 0;
221
222my $in_string = 0;
223
224my ($okmsg, $comment_prefix);
225
226$line = '';
227$prev = '';
228reset_indent();
229
230line: while (<$filehandle>) {
231	s/\r?\n$//;	# strip return and newline
232
233	# save the original line, then remove all text from within
234	# double or single quotes, we do not want to check such text.
235
236	$line = $_;
237
238	#
239	# C allows strings to be continued with a backslash at the end of
240	# the line.  We translate that into a quoted string on the previous
241	# line followed by an initial quote on the next line.
242	#
243	# (we assume that no-one will use backslash-continuation with character
244	# constants)
245	#
246	$_ = '"' . $_		if ($in_string && !$nocheck && !$in_comment);
247
248	#
249	# normal strings and characters
250	#
251	s/'([^\\']|\\[^xX0]|\\0[0-9]*|\\[xX][0-9a-fA-F]*)'/''/g;
252	s/"([^\\"]|\\.)*"/\"\"/g;
253
254	#
255	# detect string continuation
256	#
257	if ($nocheck || $in_comment) {
258		$in_string = 0;
259	} else {
260		#
261		# Now that all full strings are replaced with "", we check
262		# for unfinished strings continuing onto the next line.
263		#
264		$in_string =
265		    (s/([^"](?:"")*)"([^\\"]|\\.)*\\$/$1""/ ||
266		    s/^("")*"([^\\"]|\\.)*\\$/""/);
267	}
268
269	#
270	# figure out if we are in a cpp directive
271	#
272	$in_cpp = $next_in_cpp || /^\s*#/;	# continued or started
273	$next_in_cpp = $in_cpp && /\\$/;	# only if continued
274
275	# strip off trailing backslashes, which appear in long macros
276	s/\s*\\$//;
277
278	# an /* END CSTYLED */ comment ends a no-check block.
279	if ($nocheck) {
280		if (/\/\* *END *CSTYLED *\*\//) {
281			$nocheck = 0;
282		} else {
283			reset_indent();
284			next line;
285		}
286	}
287
288	# a /*CSTYLED*/ comment indicates that the next line is ok.
289	if ($nextok) {
290		if ($okmsg) {
291			err($okmsg);
292		}
293		$nextok = 0;
294		$okmsg = 0;
295		if (/\/\* *CSTYLED.*\*\//) {
296			/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
297			$okmsg = $1;
298			$nextok = 1;
299		}
300		$no_errs = 1;
301	} elsif ($no_errs) {
302		$no_errs = 0;
303	}
304
305	# check length of line.
306	# first, a quick check to see if there is any chance of being too long.
307	if (($line =~ tr/\t/\t/) * 7 + length($line) > 80) {
308		# yes, there is a chance.
309		# replace tabs with spaces and check again.
310		my $eline = $line;
311		1 while $eline =~
312		    s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e;
313		if (length($eline) > 80) {
314			err("line > 80 characters");
315		}
316	}
317
318	# ignore NOTE(...) annotations (assumes NOTE is on lines by itself).
319	if ($note_level || /\b_?NOTE\s*\(/) { # if in NOTE or this is NOTE
320		s/[^()]//g;			  # eliminate all non-parens
321		$note_level += s/\(//g - length;  # update paren nest level
322		next;
323	}
324
325	# a /* BEGIN CSTYLED */ comment starts a no-check block.
326	if (/\/\* *BEGIN *CSTYLED *\*\//) {
327		$nocheck = 1;
328	}
329
330	# a /*CSTYLED*/ comment indicates that the next line is ok.
331	if (/\/\* *CSTYLED.*\*\//) {
332		/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
333		$okmsg = $1;
334		$nextok = 1;
335	}
336	if (/\/\/ *CSTYLED/) {
337		/^.*\/\/ *CSTYLED *(.*)$/;
338		$okmsg = $1;
339		$nextok = 1;
340	}
341
342	# universal checks; apply to everything
343	if (/\t +\t/) {
344		err("spaces between tabs");
345	}
346	if (/ \t+ /) {
347		err("tabs between spaces");
348	}
349	if (/\s$/) {
350		err("space or tab at end of line");
351	}
352	if (/[^ \t(]\/\*/ && !/\w\(\/\*.*\*\/\);/) {
353		err("comment preceded by non-blank");
354	}
355	if (/ARGSUSED/) {
356		err("ARGSUSED directive");
357	}
358
359	# is this the beginning or ending of a function?
360	# (not if "struct foo\n{\n")
361	if (/^\{$/ && $prev =~ /\)\s*(const\s*)?(\/\*.*\*\/\s*)?\\?$/) {
362		$in_function = 1;
363		$in_declaration = 1;
364		$in_function_header = 0;
365		$function_header_full_indent = 0;
366		$prev = $line;
367		next line;
368	}
369	if (/^\}\s*(\/\*.*\*\/\s*)*$/) {
370		if ($prev =~ /^\s*return\s*;/) {
371			err_prev("unneeded return at end of function");
372		}
373		$in_function = 0;
374		reset_indent();		# we don't check between functions
375		$prev = $line;
376		next line;
377	}
378	if ($in_function_header && ! /^    (\w|\.)/ ) {
379		if (/^\{\}$/ # empty functions
380		|| /;/ #run function with multiline arguments
381		|| /#/ #preprocessor commands
382		|| /^[^\s\\]*\(.*\)$/ #functions without ; at the end
383		|| /^$/ #function declaration can't have empty line
384		) {
385			$in_function_header = 0;
386			$function_header_full_indent = 0;
387		} elsif ($prev =~ /^__attribute__/) { #__attribute__((*))
388			$in_function_header = 0;
389			$function_header_full_indent = 0;
390			$prev = $line;
391			next line;
392		} elsif ($picky	&& ! (/^\t/ && $function_header_full_indent != 0)) {
393
394			err("continuation line should be indented by 4 spaces");
395		}
396	}
397
398	#
399	# If this matches something of form "foo(", it's probably a function
400	# definition, unless it ends with ") bar;", in which case it's a declaration
401	# that uses a macro to generate the type.
402	#
403	if (/^\w+\(/ && !/\) \w+;/) {
404		$in_function_header = 1;
405		if (/\($/) {
406			$function_header_full_indent = 1;
407		}
408	}
409	if ($in_function_header && /^\{$/) {
410		$in_function_header = 0;
411		$function_header_full_indent = 0;
412		$in_function = 1;
413	}
414	if ($in_function_header && /\);$/) {
415		$in_function_header = 0;
416		$function_header_full_indent = 0;
417	}
418	if ($in_function_header && /\{$/ ) {
419		if ($picky) {
420			err("opening brace on same line as function header");
421		}
422		$in_function_header = 0;
423		$function_header_full_indent = 0;
424		$in_function = 1;
425		next line;
426	}
427
428	if ($in_warlock_comment && /\*\//) {
429		$in_warlock_comment = 0;
430		$prev = $line;
431		next line;
432	}
433
434	# a blank line terminates the declarations within a function.
435	# XXX - but still a problem in sub-blocks.
436	if ($in_declaration && /^$/) {
437		$in_declaration = 0;
438	}
439
440	if ($comment_done) {
441		$in_comment = 0;
442		$comment_done = 0;
443	}
444	# does this looks like the start of a block comment?
445	if (/$hdr_comment_start/) {
446		if (!/^\t*\/\*/) {
447			err("block comment not indented by tabs");
448		}
449		$in_comment = 1;
450		/^(\s*)\//;
451		$comment_prefix = $1;
452		$prev = $line;
453		next line;
454	}
455	# are we still in the block comment?
456	if ($in_comment) {
457		if (/^$comment_prefix \*\/$/) {
458			$comment_done = 1;
459		} elsif (/\*\//) {
460			$comment_done = 1;
461			err("improper block comment close");
462		} elsif (!/^$comment_prefix \*[ \t]/ &&
463		    !/^$comment_prefix \*$/) {
464			err("improper block comment");
465		}
466	}
467
468	# check for errors that might occur in comments and in code.
469
470	# allow spaces to be used to draw pictures in all comments.
471	if (/[^ ]     / && !/".*     .*"/ && !$in_comment) {
472		err("spaces instead of tabs");
473	}
474	if (/^ / && !/^ \*[ \t\/]/ && !/^ \*$/ &&
475	    (!/^    (\w|\.)/ || $in_function != 0)) {
476		err("indent by spaces instead of tabs");
477	}
478	if (/^\t+ [^ \t\*]/ || /^\t+  \S/ || /^\t+   \S/) {
479		err("continuation line not indented by 4 spaces");
480	}
481	if (/$warlock_re/ && !/\*\//) {
482		$in_warlock_comment = 1;
483		$prev = $line;
484		next line;
485	}
486	if (/^\s*\/\*./ && !/^\s*\/\*.*\*\// && !/$hdr_comment_start/) {
487		err("improper first line of block comment");
488	}
489
490	if ($in_comment) {	# still in comment, don't do further checks
491		$prev = $line;
492		next line;
493	}
494
495	if ((/[^(]\/\*\S/ || /^\/\*\S/) && !/$lint_re/) {
496		err("missing blank after open comment");
497	}
498	if (/\S\*\/[^)]|\S\*\/$/ && !/$lint_re/) {
499		err("missing blank before close comment");
500	}
501	# check for unterminated single line comments, but allow them when
502	# they are used to comment out the argument list of a function
503	# declaration.
504	if (/\S.*\/\*/ && !/\S.*\/\*.*\*\// && !/\(\/\*/) {
505		err("unterminated single line comment");
506	}
507
508	if (/^(#else|#endif|#include)(.*)$/) {
509		$prev = $line;
510		if ($picky) {
511			my $directive = $1;
512			my $clause = $2;
513			# Enforce ANSI rules for #else and #endif: no noncomment
514			# identifiers are allowed after #endif or #else.  Allow
515			# C++ comments since they seem to be a fact of life.
516			if ((($1 eq "#endif") || ($1 eq "#else")) &&
517			    ($clause ne "") &&
518			    (!($clause =~ /^\s+\/\*.*\*\/$/)) &&
519			    (!($clause =~ /^\s+\/\/.*$/))) {
520				err("non-comment text following " .
521				    "$directive (or malformed $directive " .
522				    "directive)");
523			}
524		}
525		next line;
526	}
527
528	#
529	# delete any comments and check everything else.  Note that
530	# ".*?" is a non-greedy match, so that we don't get confused by
531	# multiple comments on the same line.
532	#
533	s/\/\*.*?\*\///g;
534	s/\/\/(?:\s.*)?$//;	# Valid C++ comments
535
536	# After stripping correctly spaced comments, check for (and strip) comments
537	# without a blank.  By checking this after clearing out C++ comments that
538	# correctly have a blank, we guarantee URIs in a C++ comment will not cause
539	# an error.
540	if (s!//.*$!!) {		# C++ comments
541		err("missing blank after start comment");
542	}
543
544	# delete any trailing whitespace; we have already checked for that.
545	s/\s*$//;
546
547	# following checks do not apply to text in comments.
548
549	if (/[^<>\s][!<>=]=/ || /[^<>][!<>=]=[^\s,]/ ||
550	    (/[^->]>[^,=>\s]/ && !/[^->]>$/) ||
551	    (/[^<]<[^,=<\s]/ && !/[^<]<$/) ||
552	    /[^<\s]<[^<]/ || /[^->\s]>[^>]/) {
553		err("missing space around relational operator");
554	}
555	if (/\S>>=/ || /\S<<=/ || />>=\S/ || /<<=\S/ || /\S[-+*\/&|^%]=/ ||
556	    (/[^-+*\/&|^%!<>=\s]=[^=]/ && !/[^-+*\/&|^%!<>=\s]=$/) ||
557	    (/[^!<>=]=[^=\s]/ && !/[^!<>=]=$/)) {
558		# XXX - should only check this for C++ code
559		# XXX - there are probably other forms that should be allowed
560		if (!/\soperator=/) {
561			err("missing space around assignment operator");
562		}
563	}
564	if (/[,;]\S/ && !/\bfor \(;;\)/) {
565		err("comma or semicolon followed by non-blank");
566	}
567	# allow "for" statements to have empty "while" clauses
568	if (/\s[,;]/ && !/^[\t]+;$/ && !/^\s*for \([^;]*; ;[^;]*\)/) {
569		err("comma or semicolon preceded by blank");
570	}
571	if (/^\s*(&&|\|\|)/) {
572		err("improper boolean continuation");
573	}
574	if (/\S   *(&&|\|\|)/ || /(&&|\|\|)   *\S/) {
575		err("more than one space around boolean operator");
576	}
577	if (/\b(for|if|while|switch|sizeof|return|case)\(/) {
578		err("missing space between keyword and paren");
579	}
580	if (/(\b(for|if|while|switch|return)\b.*){2,}/ && !/^#define/) {
581		# multiple "case" and "sizeof" allowed
582		err("more than one keyword on line");
583	}
584	if (/\b(for|if|while|switch|sizeof|return|case)\s\s+\(/ &&
585	    !/^#if\s+\(/) {
586		err("extra space between keyword and paren");
587	}
588	# try to detect "func (x)" but not "if (x)" or
589	# "#define foo (x)" or "int (*func)();"
590	if (/\w\s\(/) {
591		my $s = $_;
592		# strip off all keywords on the line
593		s/\b(for|if|while|switch|return|case|sizeof)\s\(/XXX(/g;
594		s/#elif\s\(/XXX(/g;
595		s/^#define\s+\w+\s+\(/XXX(/;
596		# do not match things like "void (*f)();"
597		# or "typedef void (func_t)();"
598		s/\w\s\(+\*/XXX(*/g;
599		s/\b($typename|void)\s+\(+/XXX(/og;
600		if (/\w\s\(/) {
601			err("extra space between function name and left paren");
602		}
603		$_ = $s;
604	}
605	# try to detect "int foo(x)", but not "extern int foo(x);"
606	# XXX - this still trips over too many legitimate things,
607	# like "int foo(x,\n\ty);"
608#		if (/^(\w+(\s|\*)+)+\w+\(/ && !/\)[;,](\s|)*$/ &&
609#		    !/^(extern|static)\b/) {
610#			err("return type of function not on separate line");
611#		}
612	# this is a close approximation
613	if (/^(\w+(\s|\*)+)+\w+\(.*\)(\s|)*$/ &&
614	    !/^(extern|static)\b/) {
615		err("return type of function not on separate line");
616	}
617	if (/^#define /) {
618		err("#define followed by space instead of tab");
619	}
620	if (/^\s*return\W[^;]*;/ && !/^\s*return\s*\(.*\);/) {
621		err("unparenthesized return expression");
622	}
623	if (/\bsizeof\b/ && !/\bsizeof\s*\(.*\)/) {
624		err("unparenthesized sizeof expression");
625	}
626	if (/\(\s/) {
627		err("whitespace after left paren");
628	}
629	# Allow "for" statements to have empty "continue" clauses.
630	# Allow right paren on its own line unless we're being picky (-p).
631	if (/\s\)/ && !/^\s*for \([^;]*;[^;]*; \)/ && ($picky || !/^\s*\)/)) {
632		err("whitespace before right paren");
633	}
634	if (/^\s*\(void\)[^ ]/) {
635		err("missing space after (void) cast");
636	}
637	if (/\S\{/ && !/\{\{/) {
638		err("missing space before left brace");
639	}
640	if ($in_function && /^\s+\{/ &&
641	    ($prev =~ /\)\s*$/ || $prev =~ /\bstruct\s+\w+$/)) {
642		err("left brace starting a line");
643	}
644	if (/\}(else|while)/) {
645		err("missing space after right brace");
646	}
647	if (/\}\s\s+(else|while)/) {
648		err("extra space after right brace");
649	}
650	if (/\b_VOID\b|\bVOID\b|\bSTATIC\b/) {
651		err("obsolete use of VOID or STATIC");
652	}
653	if (/\b$typename\*/o) {
654		err("missing space between type name and *");
655	}
656	if (/^\s+#/) {
657		err("preprocessor statement not in column 1");
658	}
659	if (/^#\s/) {
660		err("blank after preprocessor #");
661	}
662	if (/!\s*(strcmp|strncmp|bcmp)\s*\(/) {
663		err("don't use boolean ! with comparison functions");
664	}
665
666	#
667	# We completely ignore, for purposes of indentation:
668	#  * lines outside of functions
669	#  * preprocessor lines
670	#
671	if ($check_continuation && $in_function && !$in_cpp) {
672		process_indent($_);
673	}
674	if ($picky) {
675		# try to detect spaces after casts, but allow (e.g.)
676		# "sizeof (int) + 1", "void (*funcptr)(int) = foo;", and
677		# "int foo(int) __NORETURN;"
678		if ((/^\($typename( \*+)?\)\s/o ||
679		    /\W\($typename( \*+)?\)\s/o) &&
680		    !/sizeof\s*\($typename( \*)?\)\s/o &&
681		    !/\($typename( \*+)?\)\s+=[^=]/o) {
682			err("space after cast");
683		}
684		if (/\b$typename\s*\*\s/o &&
685		    !/\b$typename\s*\*\s+const\b/o) {
686			err("unary * followed by space");
687		}
688	}
689	if ($check_posix_types) {
690		# try to detect old non-POSIX types.
691		# POSIX requires all non-standard typedefs to end in _t,
692		# but historically these have been used.
693		if (/\b(unchar|ushort|uint|ulong|u_int|u_short|u_long|u_char|quad)\b/) {
694			err("non-POSIX typedef $1 used: use $old2posix{$1} instead");
695		}
696	}
697	if (/^\s*else\W/) {
698		if ($prev =~ /^\s*\}$/) {
699			err_prefix($prev,
700			    "else and right brace should be on same line");
701		}
702	}
703	$prev = $line;
704}
705
706if ($prev eq "") {
707	err("last line in file is blank");
708}
709
710}
711
712#
713# Continuation-line checking
714#
715# The rest of this file contains the code for the continuation checking
716# engine.  It's a pretty simple state machine which tracks the expression
717# depth (unmatched '('s and '['s).
718#
719# Keep in mind that the argument to process_indent() has already been heavily
720# processed; all comments have been replaced by control-A, and the contents of
721# strings and character constants have been elided.
722#
723
724my $cont_in;		# currently inside of a continuation
725my $cont_off;		# skipping an initializer or definition
726my $cont_noerr;		# suppress cascading errors
727my $cont_start;		# the line being continued
728my $cont_base;		# the base indentation
729my $cont_first;		# this is the first line of a statement
730my $cont_multiseg;	# this continuation has multiple segments
731
732my $cont_special;	# this is a C statement (if, for, etc.)
733my $cont_macro;		# this is a macro
734my $cont_case;		# this is a multi-line case
735
736my @cont_paren;		# the stack of unmatched ( and [s we've seen
737
738sub
739reset_indent()
740{
741	$cont_in = 0;
742	$cont_off = 0;
743}
744
745sub
746delabel($)
747{
748	#
749	# replace labels with tabs.  Note that there may be multiple
750	# labels on a line.
751	#
752	local $_ = $_[0];
753
754	while (/^(\t*)( *(?:(?:\w+\s*)|(?:case\b[^:]*)): *)(.*)$/) {
755		my ($pre_tabs, $label, $rest) = ($1, $2, $3);
756		$_ = $pre_tabs;
757		while ($label =~ s/^([^\t]*)(\t+)//) {
758			$_ .= "\t" x (length($2) + length($1) / 8);
759		}
760		$_ .= ("\t" x (length($label) / 8)).$rest;
761	}
762
763	return ($_);
764}
765
766sub
767process_indent($)
768{
769	require strict;
770	local $_ = $_[0];			# preserve the global $_
771
772	s///g;	# No comments
773	s/\s+$//;	# Strip trailing whitespace
774
775	return			if (/^$/);	# skip empty lines
776
777	# regexps used below; keywords taking (), macros, and continued cases
778	my $special = '(?:(?:\}\s*)?else\s+)?(?:if|for|while|switch)\b';
779	my $macro = '[A-Z_][A-Z_0-9]*\(';
780	my $case = 'case\b[^:]*$';
781
782	# skip over enumerations, array definitions, initializers, etc.
783	if ($cont_off <= 0 && !/^\s*$special/ &&
784	    (/(?:(?:\b(?:enum|struct|union)\s*[^\{]*)|(?:\s+=\s*))\{/ ||
785	    (/^\s*\{/ && $prev =~ /=\s*(?:\/\*.*\*\/\s*)*$/))) {
786		$cont_in = 0;
787		$cont_off = tr/{/{/ - tr/}/}/;
788		return;
789	}
790	if ($cont_off) {
791		$cont_off += tr/{/{/ - tr/}/}/;
792		return;
793	}
794
795	if (!$cont_in) {
796		$cont_start = $line;
797
798		if (/^\t* /) {
799			err("non-continuation indented 4 spaces");
800			$cont_noerr = 1;		# stop reporting
801		}
802		$_ = delabel($_);	# replace labels with tabs
803
804		# check if the statement is complete
805		return		if (/^\s*\}?$/);
806		return		if (/^\s*\}?\s*else\s*\{?$/);
807		return		if (/^\s*do\s*\{?$/);
808		return		if (/\{$/);
809		return		if (/\}[,;]?$/);
810
811		# Allow macros on their own lines
812		return		if (/^\s*[A-Z_][A-Z_0-9]*$/);
813
814		# cases we don't deal with, generally non-kosher
815		if (/\{/) {
816			err("stuff after {");
817			return;
818		}
819
820		# Get the base line, and set up the state machine
821		/^(\t*)/;
822		$cont_base = $1;
823		$cont_in = 1;
824		@cont_paren = ();
825		$cont_first = 1;
826		$cont_multiseg = 0;
827
828		# certain things need special processing
829		$cont_special = /^\s*$special/? 1 : 0;
830		$cont_macro = /^\s*$macro/? 1 : 0;
831		$cont_case = /^\s*$case/? 1 : 0;
832	} else {
833		$cont_first = 0;
834
835		# Strings may be pulled back to an earlier (half-)tabstop
836		unless ($cont_noerr || /^$cont_base    / ||
837		    (/^\t*(?:    )?(?:gettext\()?\"/ && !/^$cont_base\t/)) {
838			err_prefix($cont_start,
839			    "continuation should be indented 4 spaces");
840		}
841	}
842
843	my $rest = $_;			# keeps the remainder of the line
844
845	#
846	# The split matches 0 characters, so that each 'special' character
847	# is processed separately.  Parens and brackets are pushed and
848	# popped off the @cont_paren stack.  For normal processing, we wait
849	# until a ; or { terminates the statement.  "special" processing
850	# (if/for/while/switch) is allowed to stop when the stack empties,
851	# as is macro processing.  Case statements are terminated with a :
852	# and an empty paren stack.
853	#
854	foreach $_ (split /[^\(\)\[\]\{\}\;\:]*/) {
855		next		if (length($_) == 0);
856
857		# rest contains the remainder of the line
858		my $rxp = "[^\Q$_\E]*\Q$_\E";
859		$rest =~ s/^$rxp//;
860
861		if (/\(/ || /\[/) {
862			push @cont_paren, $_;
863		} elsif (/\)/ || /\]/) {
864			my $cur = $_;
865			tr/\)\]/\(\[/;
866
867			my $old = (pop @cont_paren);
868			if (!defined($old)) {
869				err("unexpected '$cur'");
870				$cont_in = 0;
871				last;
872			} elsif ($old ne $_) {
873				err("'$cur' mismatched with '$old'");
874				$cont_in = 0;
875				last;
876			}
877
878			#
879			# If the stack is now empty, do special processing
880			# for if/for/while/switch and macro statements.
881			#
882			next		if (@cont_paren != 0);
883			if ($cont_special) {
884				if ($rest =~ /^\s*\{?$/) {
885					$cont_in = 0;
886					last;
887				}
888				if ($rest =~ /^\s*;$/) {
889					err("empty if/for/while body ".
890					    "not on its own line");
891					$cont_in = 0;
892					last;
893				}
894				if (!$cont_first && $cont_multiseg == 1) {
895					err_prefix($cont_start,
896					    "multiple statements continued ".
897					    "over multiple lines");
898					$cont_multiseg = 2;
899				} elsif ($cont_multiseg == 0) {
900					$cont_multiseg = 1;
901				}
902				# We've finished this section, start
903				# processing the next.
904				goto section_ended;
905			}
906			if ($cont_macro) {
907				if ($rest =~ /^$/) {
908					$cont_in = 0;
909					last;
910				}
911			}
912		} elsif (/\;/) {
913			if ($cont_case) {
914				err("unexpected ;");
915			} elsif (!$cont_special) {
916				err("unexpected ;")	if (@cont_paren != 0);
917				if (!$cont_first && $cont_multiseg == 1) {
918					err_prefix($cont_start,
919					    "multiple statements continued ".
920					    "over multiple lines");
921					$cont_multiseg = 2;
922				} elsif ($cont_multiseg == 0) {
923					$cont_multiseg = 1;
924				}
925				if ($rest =~ /^$/) {
926					$cont_in = 0;
927					last;
928				}
929				if ($rest =~ /^\s*special/) {
930					err("if/for/while/switch not started ".
931					    "on its own line");
932				}
933				goto section_ended;
934			}
935		} elsif (/\{/) {
936			err("{ while in parens/brackets") if (@cont_paren != 0);
937			err("stuff after {")		if ($rest =~ /[^\s}]/);
938			$cont_in = 0;
939			last;
940		} elsif (/\}/) {
941			err("} while in parens/brackets") if (@cont_paren != 0);
942			if (!$cont_special && $rest !~ /^\s*(while|else)\b/) {
943				if ($rest =~ /^$/) {
944					err("unexpected }");
945				} else {
946					err("stuff after }");
947				}
948				$cont_in = 0;
949				last;
950			}
951		} elsif (/\:/ && $cont_case && @cont_paren == 0) {
952			err("stuff after multi-line case") if ($rest !~ /$^/);
953			$cont_in = 0;
954			last;
955		}
956		next;
957section_ended:
958		# End of a statement or if/while/for loop.  Reset
959		# cont_special and cont_macro based on the rest of the
960		# line.
961		$cont_special = ($rest =~ /^\s*$special/)? 1 : 0;
962		$cont_macro = ($rest =~ /^\s*$macro/)? 1 : 0;
963		$cont_case = 0;
964		next;
965	}
966	$cont_noerr = 0			if (!$cont_in);
967}
968