xref: /freebsd/sys/contrib/openzfs/scripts/cstyle.pl (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1#!/usr/bin/env perl
2# SPDX-License-Identifier: CDDL-1.0
3#
4# CDDL HEADER START
5#
6# The contents of this file are subject to the terms of the
7# Common Development and Distribution License (the "License").
8# You may not use this file except in compliance with the License.
9#
10# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
11# or https://opensource.org/licenses/CDDL-1.0.
12# See the License for the specific language governing permissions
13# and limitations under the License.
14#
15# When distributing Covered Code, include this CDDL HEADER in each
16# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
17# If applicable, add the following below this CDDL HEADER, with the
18# fields enclosed by brackets "[]" replaced with your own identifying
19# information: Portions Copyright [yyyy] [name of copyright owner]
20#
21# CDDL HEADER END
22#
23# Copyright 2016 Nexenta Systems, Inc.
24#
25# Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
26# Use is subject to license terms.
27#
28# @(#)cstyle 1.58 98/09/09 (from shannon)
29#ident	"%Z%%M%	%I%	%E% SMI"
30#
31# cstyle - check for some common stylistic errors.
32#
33#	cstyle is a sort of "lint" for C coding style.
34#	It attempts to check for the style used in the
35#	kernel, sometimes known as "Bill Joy Normal Form".
36#
37#	There's a lot this can't check for, like proper indentation
38#	of code blocks.  There's also a lot more this could check for.
39#
40#	A note to the non perl literate:
41#
42#		perl regular expressions are pretty much like egrep
43#		regular expressions, with the following special symbols
44#
45#		\s	any space character
46#		\S	any non-space character
47#		\w	any "word" character [a-zA-Z0-9_]
48#		\W	any non-word character
49#		\d	a digit [0-9]
50#		\D	a non-digit
51#		\b	word boundary (between \w and \W)
52#		\B	non-word boundary
53#
54
55require 5.0;
56use warnings;
57use IO::File;
58use Getopt::Std;
59use strict;
60
61my $usage =
62"usage: cstyle [-cgpvP] file...
63	-c	check continuation indentation inside functions
64	-g	print github actions' workflow commands
65	-p	perform some of the more picky checks
66	-v	verbose
67	-P	check for use of non-POSIX types
68";
69
70my %opts;
71
72if (!getopts("cghpvCP", \%opts)) {
73	print $usage;
74	exit 2;
75}
76
77my $check_continuation = $opts{'c'};
78my $github_workflow = $opts{'g'} || $ENV{'CI'};
79my $picky = $opts{'p'};
80my $verbose = $opts{'v'};
81my $check_posix_types = $opts{'P'};
82
83my ($filename, $line, $prev);		# shared globals
84
85my $fmt;
86my $hdr_comment_start;
87
88if ($verbose) {
89	$fmt = "%s: %d: %s\n%s\n";
90} else {
91	$fmt = "%s: %d: %s\n";
92}
93
94$hdr_comment_start = qr/^\s*\/\*$/;
95
96# Note, following must be in single quotes so that \s and \w work right.
97my $typename = '(int|char|short|long|unsigned|float|double' .
98    '|\w+_t|struct\s+\w+|union\s+\w+|FILE)';
99
100# mapping of old types to POSIX compatible types
101my %old2posix = (
102	'unchar' => 'uchar_t',
103	'ushort' => 'ushort_t',
104	'uint' => 'uint_t',
105	'ulong' => 'ulong_t',
106	'u_int' => 'uint_t',
107	'u_short' => 'ushort_t',
108	'u_long' => 'ulong_t',
109	'u_char' => 'uchar_t',
110	'quad' => 'quad_t'
111);
112
113my $lint_re = qr/\/\*(?:
114	NOTREACHED|LINTLIBRARY|VARARGS[0-9]*|
115	CONSTCOND|CONSTANTCOND|CONSTANTCONDITION|EMPTY|
116	FALLTHRU|FALLTHROUGH|LINTED.*?|PRINTFLIKE[0-9]*|
117	PROTOLIB[0-9]*|SCANFLIKE[0-9]*|CSTYLED.*?
118    )\*\//x;
119
120my $warlock_re = qr/\/\*\s*(?:
121	VARIABLES\ PROTECTED\ BY|
122	MEMBERS\ PROTECTED\ BY|
123	ALL\ MEMBERS\ PROTECTED\ BY|
124	READ-ONLY\ VARIABLES:|
125	READ-ONLY\ MEMBERS:|
126	VARIABLES\ READABLE\ WITHOUT\ LOCK:|
127	MEMBERS\ READABLE\ WITHOUT\ LOCK:|
128	LOCKS\ COVERED\ BY|
129	LOCK\ UNNEEDED\ BECAUSE|
130	LOCK\ NEEDED:|
131	LOCK\ HELD\ ON\ ENTRY:|
132	READ\ LOCK\ HELD\ ON\ ENTRY:|
133	WRITE\ LOCK\ HELD\ ON\ ENTRY:|
134	LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
135	READ\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
136	WRITE\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
137	LOCK\ RELEASED\ AS\ SIDE\ EFFECT:|
138	LOCK\ UPGRADED\ AS\ SIDE\ EFFECT:|
139	LOCK\ DOWNGRADED\ AS\ SIDE\ EFFECT:|
140	FUNCTIONS\ CALLED\ THROUGH\ POINTER|
141	FUNCTIONS\ CALLED\ THROUGH\ MEMBER|
142	LOCK\ ORDER:
143    )/x;
144
145my $err_stat = 0;		# exit status
146
147if ($#ARGV >= 0) {
148	foreach my $arg (@ARGV) {
149		my $fh = new IO::File $arg, "r";
150		if (!defined($fh)) {
151			printf "%s: can not open\n", $arg;
152		} else {
153			&cstyle($arg, $fh);
154			close $fh;
155		}
156	}
157} else {
158	&cstyle("<stdin>", *STDIN);
159}
160exit $err_stat;
161
162my $no_errs = 0;		# set for CSTYLED-protected lines
163
164sub err($) {
165	my ($error) = @_;
166	unless ($no_errs) {
167		if ($verbose) {
168			printf $fmt, $filename, $., $error, $line;
169		} else {
170			printf $fmt, $filename, $., $error;
171		}
172		if ($github_workflow) {
173			printf "::error file=%s,line=%s::%s\n", $filename, $., $error;
174		}
175		$err_stat = 1;
176	}
177}
178
179sub err_prefix($$) {
180	my ($prevline, $error) = @_;
181	my $out = $prevline."\n".$line;
182	unless ($no_errs) {
183		if ($verbose) {
184			printf $fmt, $filename, $., $error, $out;
185		} else {
186			printf $fmt, $filename, $., $error;
187		}
188		$err_stat = 1;
189	}
190}
191
192sub err_prev($) {
193	my ($error) = @_;
194	unless ($no_errs) {
195		if ($verbose) {
196			printf $fmt, $filename, $. - 1, $error, $prev;
197		} else {
198			printf $fmt, $filename, $. - 1, $error;
199		}
200		$err_stat = 1;
201	}
202}
203
204sub cstyle($$) {
205
206my ($fn, $filehandle) = @_;
207$filename = $fn;			# share it globally
208
209my $in_cpp = 0;
210my $next_in_cpp = 0;
211
212my $in_comment = 0;
213my $comment_done = 0;
214my $in_warlock_comment = 0;
215my $in_macro_call = 0;
216my $in_function = 0;
217my $in_function_header = 0;
218my $function_header_full_indent = 0;
219my $in_declaration = 0;
220my $note_level = 0;
221my $nextok = 0;
222my $nocheck = 0;
223
224my $in_string = 0;
225
226my ($okmsg, $comment_prefix);
227
228$line = '';
229$prev = '';
230reset_indent();
231
232line: while (<$filehandle>) {
233	s/\r?\n$//;	# strip return and newline
234
235	# save the original line, then remove all text from within
236	# double or single quotes, we do not want to check such text.
237
238	$line = $_;
239
240	#
241	# C allows strings to be continued with a backslash at the end of
242	# the line.  We translate that into a quoted string on the previous
243	# line followed by an initial quote on the next line.
244	#
245	# (we assume that no-one will use backslash-continuation with character
246	# constants)
247	#
248	$_ = '"' . $_		if ($in_string && !$nocheck && !$in_comment);
249
250	#
251	# normal strings and characters
252	#
253	s/'([^\\']|\\[^xX0]|\\0[0-9]*|\\[xX][0-9a-fA-F]*)'/''/g;
254	s/"([^\\"]|\\.)*"/\"\"/g;
255
256	#
257	# detect string continuation
258	#
259	if ($nocheck || $in_comment) {
260		$in_string = 0;
261	} else {
262		#
263		# Now that all full strings are replaced with "", we check
264		# for unfinished strings continuing onto the next line.
265		#
266		$in_string =
267		    (s/([^"](?:"")*)"([^\\"]|\\.)*\\$/$1""/ ||
268		    s/^("")*"([^\\"]|\\.)*\\$/""/);
269	}
270
271	#
272	# figure out if we are in a cpp directive
273	#
274	$in_cpp = $next_in_cpp || /^\s*#/;	# continued or started
275	$next_in_cpp = $in_cpp && /\\$/;	# only if continued
276
277	# strip off trailing backslashes, which appear in long macros
278	s/\s*\\$//;
279
280	# an /* END CSTYLED */ comment ends a no-check block.
281	if ($nocheck) {
282		if (/\/\* *END *CSTYLED *\*\//) {
283			$nocheck = 0;
284		} else {
285			reset_indent();
286			next line;
287		}
288	}
289
290	# a /*CSTYLED*/ comment indicates that the next line is ok.
291	if ($nextok) {
292		if ($okmsg) {
293			err($okmsg);
294		}
295		$nextok = 0;
296		$okmsg = 0;
297		if (/\/\* *CSTYLED.*\*\//) {
298			/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
299			$okmsg = $1;
300			$nextok = 1;
301		}
302		$no_errs = 1;
303	} elsif ($no_errs) {
304		$no_errs = 0;
305	}
306
307	# check length of line.
308	# first, a quick check to see if there is any chance of being too long.
309	if (($line =~ tr/\t/\t/) * 7 + length($line) > 80) {
310		# yes, there is a chance.
311		# replace tabs with spaces and check again.
312		my $eline = $line;
313		1 while $eline =~
314		    s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e;
315		if (length($eline) > 80) {
316			err("line > 80 characters");
317		}
318	}
319
320	# ignore NOTE(...) annotations (assumes NOTE is on lines by itself).
321	if ($note_level || /\b_?NOTE\s*\(/) { # if in NOTE or this is NOTE
322		s/[^()]//g;			  # eliminate all non-parens
323		$note_level += s/\(//g - length;  # update paren nest level
324		next;
325	}
326
327	# a /* BEGIN CSTYLED */ comment starts a no-check block.
328	if (/\/\* *BEGIN *CSTYLED *\*\//) {
329		$nocheck = 1;
330	}
331
332	# a /*CSTYLED*/ comment indicates that the next line is ok.
333	if (/\/\* *CSTYLED.*\*\//) {
334		/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
335		$okmsg = $1;
336		$nextok = 1;
337	}
338	if (/\/\/ *CSTYLED/) {
339		/^.*\/\/ *CSTYLED *(.*)$/;
340		$okmsg = $1;
341		$nextok = 1;
342	}
343
344	# universal checks; apply to everything
345	if (/\t +\t/) {
346		err("spaces between tabs");
347	}
348	if (/ \t+ /) {
349		err("tabs between spaces");
350	}
351	if (/\s$/) {
352		err("space or tab at end of line");
353	}
354	if (/[^ \t(]\/\*/ && !/\w\(\/\*.*\*\/\);/) {
355		err("comment preceded by non-blank");
356	}
357	if (/ARGSUSED/) {
358		err("ARGSUSED directive");
359	}
360
361	# is this the beginning or ending of a function?
362	# (not if "struct foo\n{\n")
363	if (/^\{$/ && $prev =~ /\)\s*(const\s*)?(\/\*.*\*\/\s*)?\\?$/) {
364		$in_function = 1;
365		$in_declaration = 1;
366		$in_function_header = 0;
367		$function_header_full_indent = 0;
368		$prev = $line;
369		next line;
370	}
371	if (/^\}\s*(\/\*.*\*\/\s*)*$/) {
372		if ($prev =~ /^\s*return\s*;/) {
373			err_prev("unneeded return at end of function");
374		}
375		$in_function = 0;
376		reset_indent();		# we don't check between functions
377		$prev = $line;
378		next line;
379	}
380	if ($in_function_header && ! /^    (\w|\.)/ ) {
381		if (/^\{\}$/ # empty functions
382		|| /;/ #run function with multiline arguments
383		|| /#/ #preprocessor commands
384		|| /^[^\s\\]*\(.*\)$/ #functions without ; at the end
385		|| /^$/ #function declaration can't have empty line
386		) {
387			$in_function_header = 0;
388			$function_header_full_indent = 0;
389		} elsif ($prev =~ /^__attribute__/) { #__attribute__((*))
390			$in_function_header = 0;
391			$function_header_full_indent = 0;
392			$prev = $line;
393			next line;
394		} elsif ($picky	&& ! (/^\t/ && $function_header_full_indent != 0)) {
395
396			err("continuation line should be indented by 4 spaces");
397		}
398	}
399
400	# If this looks like a top-level macro invocation, remember it so we
401	# don't mistake it for a function declaration below.
402	if (/^[A-Za-z_][A-Za-z_0-9]*\(/) {
403		$in_macro_call = 1;
404	}
405
406	#
407	# If this matches something of form "foo(", it's probably a function
408	# definition, unless it ends with ") bar;", in which case it's a declaration
409	# that uses a macro to generate the type.
410	#
411	if (!$in_macro_call && /^\w+\(/ && !/\) \w+;/) {
412		$in_function_header = 1;
413		if (/\($/) {
414			$function_header_full_indent = 1;
415		}
416	}
417	if ($in_function_header && /^\{$/) {
418		$in_function_header = 0;
419		$function_header_full_indent = 0;
420		$in_function = 1;
421	}
422	if ($in_function_header && /\);$/) {
423		$in_function_header = 0;
424		$function_header_full_indent = 0;
425	}
426	if ($in_function_header && /\{$/ ) {
427		if ($picky) {
428			err("opening brace on same line as function header");
429		}
430		$in_function_header = 0;
431		$function_header_full_indent = 0;
432		$in_function = 1;
433		next line;
434	}
435
436	if ($in_warlock_comment && /\*\//) {
437		$in_warlock_comment = 0;
438		$prev = $line;
439		next line;
440	}
441
442	# a blank line terminates the declarations within a function.
443	# XXX - but still a problem in sub-blocks.
444	if ($in_declaration && /^$/) {
445		$in_declaration = 0;
446	}
447
448	if ($comment_done) {
449		$in_comment = 0;
450		$comment_done = 0;
451	}
452	# does this looks like the start of a block comment?
453	if (/$hdr_comment_start/) {
454		if (!/^\t*\/\*/) {
455			err("block comment not indented by tabs");
456		}
457		$in_comment = 1;
458		/^(\s*)\//;
459		$comment_prefix = $1;
460		$prev = $line;
461		next line;
462	}
463	# are we still in the block comment?
464	if ($in_comment) {
465		if (/^$comment_prefix \*\/$/) {
466			$comment_done = 1;
467		} elsif (/\*\//) {
468			$comment_done = 1;
469			err("improper block comment close");
470		} elsif (!/^$comment_prefix \*[ \t]/ &&
471		    !/^$comment_prefix \*$/) {
472			err("improper block comment");
473		}
474	}
475
476	# check for errors that might occur in comments and in code.
477
478	# allow spaces to be used to draw pictures in all comments.
479	if (/[^ ]     / && !/".*     .*"/ && !$in_comment) {
480		err("spaces instead of tabs");
481	}
482	if (/^ / && !/^ \*[ \t\/]/ && !/^ \*$/ &&
483	    (!/^    (\w|\.)/ || $in_function != 0)) {
484		err("indent by spaces instead of tabs");
485	}
486	if (/^\t+ [^ \t\*]/ || /^\t+  \S/ || /^\t+   \S/) {
487		err("continuation line not indented by 4 spaces");
488	}
489	if (/$warlock_re/ && !/\*\//) {
490		$in_warlock_comment = 1;
491		$prev = $line;
492		next line;
493	}
494	if (/^\s*\/\*./ && !/^\s*\/\*.*\*\// && !/$hdr_comment_start/) {
495		err("improper first line of block comment");
496	}
497
498	if ($in_comment) {	# still in comment, don't do further checks
499		$prev = $line;
500		next line;
501	}
502
503	if ((/[^(]\/\*\S/ || /^\/\*\S/) && !/$lint_re/) {
504		err("missing blank after open comment");
505	}
506	if (/\S\*\/[^)]|\S\*\/$/ && !/$lint_re/) {
507		err("missing blank before close comment");
508	}
509	# check for unterminated single line comments, but allow them when
510	# they are used to comment out the argument list of a function
511	# declaration.
512	if (/\S.*\/\*/ && !/\S.*\/\*.*\*\// && !/\(\/\*/) {
513		err("unterminated single line comment");
514	}
515
516	if (/^(#else|#endif|#include)(.*)$/) {
517		$prev = $line;
518		if ($picky) {
519			my $directive = $1;
520			my $clause = $2;
521			# Enforce ANSI rules for #else and #endif: no noncomment
522			# identifiers are allowed after #endif or #else.  Allow
523			# C++ comments since they seem to be a fact of life.
524			if ((($1 eq "#endif") || ($1 eq "#else")) &&
525			    ($clause ne "") &&
526			    (!($clause =~ /^\s+\/\*.*\*\/$/)) &&
527			    (!($clause =~ /^\s+\/\/.*$/))) {
528				err("non-comment text following " .
529				    "$directive (or malformed $directive " .
530				    "directive)");
531			}
532		}
533		next line;
534	}
535
536	#
537	# delete any comments and check everything else.  Note that
538	# ".*?" is a non-greedy match, so that we don't get confused by
539	# multiple comments on the same line.
540	#
541	s/\/\*.*?\*\///g;
542	s/\/\/(?:\s.*)?$//;	# Valid C++ comments
543
544	# After stripping correctly spaced comments, check for (and strip) comments
545	# without a blank.  By checking this after clearing out C++ comments that
546	# correctly have a blank, we guarantee URIs in a C++ comment will not cause
547	# an error.
548	if (s!//.*$!!) {		# C++ comments
549		err("missing blank after start comment");
550	}
551
552	# delete any trailing whitespace; we have already checked for that.
553	s/\s*$//;
554
555	# following checks do not apply to text in comments.
556
557	if (/[^<>\s][!<>=]=/ || /[^<>][!<>=]=[^\s,]/ ||
558	    (/[^->]>[^,=>\s]/ && !/[^->]>$/) ||
559	    (/[^<]<[^,=<\s]/ && !/[^<]<$/) ||
560	    /[^<\s]<[^<]/ || /[^->\s]>[^>]/) {
561		err("missing space around relational operator");
562	}
563	if (/\S>>=/ || /\S<<=/ || />>=\S/ || /<<=\S/ || /\S[-+*\/&|^%]=/ ||
564	    (/[^-+*\/&|^%!<>=\s]=[^=]/ && !/[^-+*\/&|^%!<>=\s]=$/) ||
565	    (/[^!<>=]=[^=\s]/ && !/[^!<>=]=$/)) {
566		# XXX - should only check this for C++ code
567		# XXX - there are probably other forms that should be allowed
568		if (!/\soperator=/) {
569			err("missing space around assignment operator");
570		}
571	}
572	if (/[,;]\S/ && !/\bfor \(;;\)/) {
573		err("comma or semicolon followed by non-blank");
574	}
575	# allow "for" statements to have empty "while" clauses
576	# allow macro invocations to have empty parameters
577	if (/\s[,;]/ && !/^[\t]+;$/ &&
578	    !($in_macro_call || /^\s*for \([^;]*; ;[^;]*\)/)) {
579		err("comma or semicolon preceded by blank");
580	}
581	if (/^\s*(&&|\|\|)/) {
582		err("improper boolean continuation");
583	}
584	if (/\S   *(&&|\|\|)/ || /(&&|\|\|)   *\S/) {
585		err("more than one space around boolean operator");
586	}
587	if (/\b(for|if|while|switch|sizeof|return|case)\(/) {
588		err("missing space between keyword and paren");
589	}
590	if (/(\b(for|if|while|switch|return)\b.*){2,}/ && !/^#define/) {
591		# multiple "case" and "sizeof" allowed
592		err("more than one keyword on line");
593	}
594	if (/\b(for|if|while|switch|sizeof|return|case)\s\s+\(/ &&
595	    !/^#if\s+\(/) {
596		err("extra space between keyword and paren");
597	}
598	# try to detect "func (x)" but not "if (x)" or
599	# "#define foo (x)" or "int (*func)();"
600	if (/\w\s\(/) {
601		my $s = $_;
602		# strip off all keywords on the line
603		s/\b(for|if|while|switch|return|case|sizeof)\s\(/XXX(/g;
604		s/#elif\s\(/XXX(/g;
605		s/^#define\s+\w+\s+\(/XXX(/;
606		# do not match things like "void (*f)();"
607		# or "typedef void (func_t)();"
608		s/\w\s\(+\*/XXX(*/g;
609		s/\b($typename|void)\s+\(+/XXX(/og;
610		if (/\w\s\(/) {
611			err("extra space between function name and left paren");
612		}
613		$_ = $s;
614	}
615	# try to detect "int foo(x)", but not "extern int foo(x);"
616	# XXX - this still trips over too many legitimate things,
617	# like "int foo(x,\n\ty);"
618#		if (/^(\w+(\s|\*)+)+\w+\(/ && !/\)[;,](\s|)*$/ &&
619#		    !/^(extern|static)\b/) {
620#			err("return type of function not on separate line");
621#		}
622	# this is a close approximation
623	if (/^(\w+(\s|\*)+)+\w+\(.*\)(\s|)*$/ &&
624	    !/^(extern|static)\b/) {
625		err("return type of function not on separate line");
626	}
627	if (/^#define /) {
628		err("#define followed by space instead of tab");
629	}
630	if (/^\s*return\W[^;]*;/ && !/^\s*return\s*\(.*\);/) {
631		err("unparenthesized return expression");
632	}
633	if (/\bsizeof\b/ && !/\bsizeof\s*\(.*\)/) {
634		err("unparenthesized sizeof expression");
635	}
636	if (/\(\s/) {
637		err("whitespace after left paren");
638	}
639	# Allow "for" statements to have empty "continue" clauses.
640	# Allow right paren on its own line unless we're being picky (-p).
641	if (/\s\)/ && !/^\s*for \([^;]*;[^;]*; \)/ && ($picky || !/^\s*\)/)) {
642		err("whitespace before right paren");
643	}
644	if (/^\s*\(void\)[^ ]/) {
645		err("missing space after (void) cast");
646	}
647	if (/\S\{/ && !/\{\{/) {
648		err("missing space before left brace");
649	}
650	if ($in_function && /^\s+\{/ &&
651	    ($prev =~ /\)\s*$/ || $prev =~ /\bstruct\s+\w+$/)) {
652		err("left brace starting a line");
653	}
654	if (/\}(else|while)/) {
655		err("missing space after right brace");
656	}
657	if (/\}\s\s+(else|while)/) {
658		err("extra space after right brace");
659	}
660	if (/\b_VOID\b|\bVOID\b|\bSTATIC\b/) {
661		err("obsolete use of VOID or STATIC");
662	}
663	if (/\b$typename\*/o) {
664		err("missing space between type name and *");
665	}
666	if (/^\s+#/) {
667		err("preprocessor statement not in column 1");
668	}
669	if (/^#\s/) {
670		err("blank after preprocessor #");
671	}
672	if (/!\s*(strcmp|strncmp|bcmp)\s*\(/) {
673		err("don't use boolean ! with comparison functions");
674	}
675
676	#
677	# We completely ignore, for purposes of indentation:
678	#  * lines outside of functions
679	#  * preprocessor lines
680	#
681	if ($check_continuation && $in_function && !$in_cpp) {
682		process_indent($_);
683	}
684	if ($picky) {
685		# try to detect spaces after casts, but allow (e.g.)
686		# "sizeof (int) + 1", "void (*funcptr)(int) = foo;", and
687		# "int foo(int) __NORETURN;"
688		if ((/^\($typename( \*+)?\)\s/o ||
689		    /\W\($typename( \*+)?\)\s/o) &&
690		    !/sizeof\s*\($typename( \*)?\)\s/o &&
691		    !/\($typename( \*+)?\)\s+=[^=]/o) {
692			err("space after cast");
693		}
694		if (/\b$typename\s*\*\s/o &&
695		    !/\b$typename\s*\*\s+const\b/o) {
696			err("unary * followed by space");
697		}
698	}
699	if ($check_posix_types && !$in_macro_call) {
700		# try to detect old non-POSIX types.
701		# POSIX requires all non-standard typedefs to end in _t,
702		# but historically these have been used.
703		#
704		# We don't check inside macro invocations because macros have
705		# legitmate uses for these names in function generators.
706		if (/\b(unchar|ushort|uint|ulong|u_int|u_short|u_long|u_char|quad)\b/) {
707			err("non-POSIX typedef $1 used: use $old2posix{$1} instead");
708		}
709	}
710	if (/^\s*else\W/) {
711		if ($prev =~ /^\s*\}$/) {
712			err_prefix($prev,
713			    "else and right brace should be on same line");
714		}
715	}
716
717	# Macro invocations end with a closing paren, and possibly a semicolon.
718	# We do this check down here to make sure all the regular checks are
719	# applied to calls that appear entirely on a single line.
720	if ($in_macro_call && /\);?$/) {
721		$in_macro_call = 0;
722	}
723
724	$prev = $line;
725}
726
727if ($prev eq "") {
728	err("last line in file is blank");
729}
730
731}
732
733#
734# Continuation-line checking
735#
736# The rest of this file contains the code for the continuation checking
737# engine.  It's a pretty simple state machine which tracks the expression
738# depth (unmatched '('s and '['s).
739#
740# Keep in mind that the argument to process_indent() has already been heavily
741# processed; all comments have been replaced by control-A, and the contents of
742# strings and character constants have been elided.
743#
744
745my $cont_in;		# currently inside of a continuation
746my $cont_off;		# skipping an initializer or definition
747my $cont_noerr;		# suppress cascading errors
748my $cont_start;		# the line being continued
749my $cont_base;		# the base indentation
750my $cont_first;		# this is the first line of a statement
751my $cont_multiseg;	# this continuation has multiple segments
752
753my $cont_special;	# this is a C statement (if, for, etc.)
754my $cont_macro;		# this is a macro
755my $cont_case;		# this is a multi-line case
756
757my @cont_paren;		# the stack of unmatched ( and [s we've seen
758
759sub
760reset_indent()
761{
762	$cont_in = 0;
763	$cont_off = 0;
764}
765
766sub
767delabel($)
768{
769	#
770	# replace labels with tabs.  Note that there may be multiple
771	# labels on a line.
772	#
773	local $_ = $_[0];
774
775	while (/^(\t*)( *(?:(?:\w+\s*)|(?:case\b[^:]*)): *)(.*)$/) {
776		my ($pre_tabs, $label, $rest) = ($1, $2, $3);
777		$_ = $pre_tabs;
778		while ($label =~ s/^([^\t]*)(\t+)//) {
779			$_ .= "\t" x (length($2) + length($1) / 8);
780		}
781		$_ .= ("\t" x (length($label) / 8)).$rest;
782	}
783
784	return ($_);
785}
786
787sub
788process_indent($)
789{
790	require strict;
791	local $_ = $_[0];			# preserve the global $_
792
793	s///g;	# No comments
794	s/\s+$//;	# Strip trailing whitespace
795
796	return			if (/^$/);	# skip empty lines
797
798	# regexps used below; keywords taking (), macros, and continued cases
799	my $special = '(?:(?:\}\s*)?else\s+)?(?:if|for|while|switch)\b';
800	my $macro = '[A-Z_][A-Z_0-9]*\(';
801	my $case = 'case\b[^:]*$';
802
803	# skip over enumerations, array definitions, initializers, etc.
804	if ($cont_off <= 0 && !/^\s*$special/ &&
805	    (/(?:(?:\b(?:enum|struct|union)\s*[^\{]*)|(?:\s+=\s*))\{/ ||
806	    (/^\s*\{/ && $prev =~ /=\s*(?:\/\*.*\*\/\s*)*$/))) {
807		$cont_in = 0;
808		$cont_off = tr/{/{/ - tr/}/}/;
809		return;
810	}
811	if ($cont_off) {
812		$cont_off += tr/{/{/ - tr/}/}/;
813		return;
814	}
815
816	if (!$cont_in) {
817		$cont_start = $line;
818
819		if (/^\t* /) {
820			err("non-continuation indented 4 spaces");
821			$cont_noerr = 1;		# stop reporting
822		}
823		$_ = delabel($_);	# replace labels with tabs
824
825		# check if the statement is complete
826		return		if (/^\s*\}?$/);
827		return		if (/^\s*\}?\s*else\s*\{?$/);
828		return		if (/^\s*do\s*\{?$/);
829		return		if (/\{$/);
830		return		if (/\}[,;]?$/);
831
832		# Allow macros on their own lines
833		return		if (/^\s*[A-Z_][A-Z_0-9]*$/);
834
835		# cases we don't deal with, generally non-kosher
836		if (/\{/) {
837			err("stuff after {");
838			return;
839		}
840
841		# Get the base line, and set up the state machine
842		/^(\t*)/;
843		$cont_base = $1;
844		$cont_in = 1;
845		@cont_paren = ();
846		$cont_first = 1;
847		$cont_multiseg = 0;
848
849		# certain things need special processing
850		$cont_special = /^\s*$special/? 1 : 0;
851		$cont_macro = /^\s*$macro/? 1 : 0;
852		$cont_case = /^\s*$case/? 1 : 0;
853	} else {
854		$cont_first = 0;
855
856		# Strings may be pulled back to an earlier (half-)tabstop
857		unless ($cont_noerr || /^$cont_base    / ||
858		    (/^\t*(?:    )?(?:gettext\()?\"/ && !/^$cont_base\t/)) {
859			err_prefix($cont_start,
860			    "continuation should be indented 4 spaces");
861		}
862	}
863
864	my $rest = $_;			# keeps the remainder of the line
865
866	#
867	# The split matches 0 characters, so that each 'special' character
868	# is processed separately.  Parens and brackets are pushed and
869	# popped off the @cont_paren stack.  For normal processing, we wait
870	# until a ; or { terminates the statement.  "special" processing
871	# (if/for/while/switch) is allowed to stop when the stack empties,
872	# as is macro processing.  Case statements are terminated with a :
873	# and an empty paren stack.
874	#
875	foreach $_ (split /[^\(\)\[\]\{\}\;\:]*/) {
876		next		if (length($_) == 0);
877
878		# rest contains the remainder of the line
879		my $rxp = "[^\Q$_\E]*\Q$_\E";
880		$rest =~ s/^$rxp//;
881
882		if (/\(/ || /\[/) {
883			push @cont_paren, $_;
884		} elsif (/\)/ || /\]/) {
885			my $cur = $_;
886			tr/\)\]/\(\[/;
887
888			my $old = (pop @cont_paren);
889			if (!defined($old)) {
890				err("unexpected '$cur'");
891				$cont_in = 0;
892				last;
893			} elsif ($old ne $_) {
894				err("'$cur' mismatched with '$old'");
895				$cont_in = 0;
896				last;
897			}
898
899			#
900			# If the stack is now empty, do special processing
901			# for if/for/while/switch and macro statements.
902			#
903			next		if (@cont_paren != 0);
904			if ($cont_special) {
905				if ($rest =~ /^\s*\{?$/) {
906					$cont_in = 0;
907					last;
908				}
909				if ($rest =~ /^\s*;$/) {
910					err("empty if/for/while body ".
911					    "not on its own line");
912					$cont_in = 0;
913					last;
914				}
915				if (!$cont_first && $cont_multiseg == 1) {
916					err_prefix($cont_start,
917					    "multiple statements continued ".
918					    "over multiple lines");
919					$cont_multiseg = 2;
920				} elsif ($cont_multiseg == 0) {
921					$cont_multiseg = 1;
922				}
923				# We've finished this section, start
924				# processing the next.
925				goto section_ended;
926			}
927			if ($cont_macro) {
928				if ($rest =~ /^$/) {
929					$cont_in = 0;
930					last;
931				}
932			}
933		} elsif (/\;/) {
934			if ($cont_case) {
935				err("unexpected ;");
936			} elsif (!$cont_special) {
937				err("unexpected ;")	if (@cont_paren != 0);
938				if (!$cont_first && $cont_multiseg == 1) {
939					err_prefix($cont_start,
940					    "multiple statements continued ".
941					    "over multiple lines");
942					$cont_multiseg = 2;
943				} elsif ($cont_multiseg == 0) {
944					$cont_multiseg = 1;
945				}
946				if ($rest =~ /^$/) {
947					$cont_in = 0;
948					last;
949				}
950				if ($rest =~ /^\s*special/) {
951					err("if/for/while/switch not started ".
952					    "on its own line");
953				}
954				goto section_ended;
955			}
956		} elsif (/\{/) {
957			err("{ while in parens/brackets") if (@cont_paren != 0);
958			err("stuff after {")		if ($rest =~ /[^\s}]/);
959			$cont_in = 0;
960			last;
961		} elsif (/\}/) {
962			err("} while in parens/brackets") if (@cont_paren != 0);
963			if (!$cont_special && $rest !~ /^\s*(while|else)\b/) {
964				if ($rest =~ /^$/) {
965					err("unexpected }");
966				} else {
967					err("stuff after }");
968				}
969				$cont_in = 0;
970				last;
971			}
972		} elsif (/\:/ && $cont_case && @cont_paren == 0) {
973			err("stuff after multi-line case") if ($rest !~ /$^/);
974			$cont_in = 0;
975			last;
976		}
977		next;
978section_ended:
979		# End of a statement or if/while/for loop.  Reset
980		# cont_special and cont_macro based on the rest of the
981		# line.
982		$cont_special = ($rest =~ /^\s*$special/)? 1 : 0;
983		$cont_macro = ($rest =~ /^\s*$macro/)? 1 : 0;
984		$cont_case = 0;
985		next;
986	}
987	$cont_noerr = 0			if (!$cont_in);
988}
989