xref: /freebsd/sys/contrib/openzfs/scripts/cstyle.pl (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
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_macro_call = 0;
215my $in_function = 0;
216my $in_function_header = 0;
217my $function_header_full_indent = 0;
218my $in_declaration = 0;
219my $note_level = 0;
220my $nextok = 0;
221my $nocheck = 0;
222
223my $in_string = 0;
224
225my ($okmsg, $comment_prefix);
226
227$line = '';
228$prev = '';
229reset_indent();
230
231line: while (<$filehandle>) {
232	s/\r?\n$//;	# strip return and newline
233
234	# save the original line, then remove all text from within
235	# double or single quotes, we do not want to check such text.
236
237	$line = $_;
238
239	#
240	# C allows strings to be continued with a backslash at the end of
241	# the line.  We translate that into a quoted string on the previous
242	# line followed by an initial quote on the next line.
243	#
244	# (we assume that no-one will use backslash-continuation with character
245	# constants)
246	#
247	$_ = '"' . $_		if ($in_string && !$nocheck && !$in_comment);
248
249	#
250	# normal strings and characters
251	#
252	s/'([^\\']|\\[^xX0]|\\0[0-9]*|\\[xX][0-9a-fA-F]*)'/''/g;
253	s/"([^\\"]|\\.)*"/\"\"/g;
254
255	#
256	# detect string continuation
257	#
258	if ($nocheck || $in_comment) {
259		$in_string = 0;
260	} else {
261		#
262		# Now that all full strings are replaced with "", we check
263		# for unfinished strings continuing onto the next line.
264		#
265		$in_string =
266		    (s/([^"](?:"")*)"([^\\"]|\\.)*\\$/$1""/ ||
267		    s/^("")*"([^\\"]|\\.)*\\$/""/);
268	}
269
270	#
271	# figure out if we are in a cpp directive
272	#
273	$in_cpp = $next_in_cpp || /^\s*#/;	# continued or started
274	$next_in_cpp = $in_cpp && /\\$/;	# only if continued
275
276	# strip off trailing backslashes, which appear in long macros
277	s/\s*\\$//;
278
279	# an /* END CSTYLED */ comment ends a no-check block.
280	if ($nocheck) {
281		if (/\/\* *END *CSTYLED *\*\//) {
282			$nocheck = 0;
283		} else {
284			reset_indent();
285			next line;
286		}
287	}
288
289	# a /*CSTYLED*/ comment indicates that the next line is ok.
290	if ($nextok) {
291		if ($okmsg) {
292			err($okmsg);
293		}
294		$nextok = 0;
295		$okmsg = 0;
296		if (/\/\* *CSTYLED.*\*\//) {
297			/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
298			$okmsg = $1;
299			$nextok = 1;
300		}
301		$no_errs = 1;
302	} elsif ($no_errs) {
303		$no_errs = 0;
304	}
305
306	# check length of line.
307	# first, a quick check to see if there is any chance of being too long.
308	if (($line =~ tr/\t/\t/) * 7 + length($line) > 80) {
309		# yes, there is a chance.
310		# replace tabs with spaces and check again.
311		my $eline = $line;
312		1 while $eline =~
313		    s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e;
314		if (length($eline) > 80) {
315			err("line > 80 characters");
316		}
317	}
318
319	# ignore NOTE(...) annotations (assumes NOTE is on lines by itself).
320	if ($note_level || /\b_?NOTE\s*\(/) { # if in NOTE or this is NOTE
321		s/[^()]//g;			  # eliminate all non-parens
322		$note_level += s/\(//g - length;  # update paren nest level
323		next;
324	}
325
326	# a /* BEGIN CSTYLED */ comment starts a no-check block.
327	if (/\/\* *BEGIN *CSTYLED *\*\//) {
328		$nocheck = 1;
329	}
330
331	# a /*CSTYLED*/ comment indicates that the next line is ok.
332	if (/\/\* *CSTYLED.*\*\//) {
333		/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
334		$okmsg = $1;
335		$nextok = 1;
336	}
337	if (/\/\/ *CSTYLED/) {
338		/^.*\/\/ *CSTYLED *(.*)$/;
339		$okmsg = $1;
340		$nextok = 1;
341	}
342
343	# universal checks; apply to everything
344	if (/\t +\t/) {
345		err("spaces between tabs");
346	}
347	if (/ \t+ /) {
348		err("tabs between spaces");
349	}
350	if (/\s$/) {
351		err("space or tab at end of line");
352	}
353	if (/[^ \t(]\/\*/ && !/\w\(\/\*.*\*\/\);/) {
354		err("comment preceded by non-blank");
355	}
356	if (/ARGSUSED/) {
357		err("ARGSUSED directive");
358	}
359
360	# is this the beginning or ending of a function?
361	# (not if "struct foo\n{\n")
362	if (/^\{$/ && $prev =~ /\)\s*(const\s*)?(\/\*.*\*\/\s*)?\\?$/) {
363		$in_function = 1;
364		$in_declaration = 1;
365		$in_function_header = 0;
366		$function_header_full_indent = 0;
367		$prev = $line;
368		next line;
369	}
370	if (/^\}\s*(\/\*.*\*\/\s*)*$/) {
371		if ($prev =~ /^\s*return\s*;/) {
372			err_prev("unneeded return at end of function");
373		}
374		$in_function = 0;
375		reset_indent();		# we don't check between functions
376		$prev = $line;
377		next line;
378	}
379	if ($in_function_header && ! /^    (\w|\.)/ ) {
380		if (/^\{\}$/ # empty functions
381		|| /;/ #run function with multiline arguments
382		|| /#/ #preprocessor commands
383		|| /^[^\s\\]*\(.*\)$/ #functions without ; at the end
384		|| /^$/ #function declaration can't have empty line
385		) {
386			$in_function_header = 0;
387			$function_header_full_indent = 0;
388		} elsif ($prev =~ /^__attribute__/) { #__attribute__((*))
389			$in_function_header = 0;
390			$function_header_full_indent = 0;
391			$prev = $line;
392			next line;
393		} elsif ($picky	&& ! (/^\t/ && $function_header_full_indent != 0)) {
394
395			err("continuation line should be indented by 4 spaces");
396		}
397	}
398
399	# If this looks like a top-level macro invocation, remember it so we
400	# don't mistake it for a function declaration below.
401	if (/^[A-Za-z_][A-Za-z_0-9]*\(/) {
402		$in_macro_call = 1;
403	}
404
405	#
406	# If this matches something of form "foo(", it's probably a function
407	# definition, unless it ends with ") bar;", in which case it's a declaration
408	# that uses a macro to generate the type.
409	#
410	if (!$in_macro_call && /^\w+\(/ && !/\) \w+;/) {
411		$in_function_header = 1;
412		if (/\($/) {
413			$function_header_full_indent = 1;
414		}
415	}
416	if ($in_function_header && /^\{$/) {
417		$in_function_header = 0;
418		$function_header_full_indent = 0;
419		$in_function = 1;
420	}
421	if ($in_function_header && /\);$/) {
422		$in_function_header = 0;
423		$function_header_full_indent = 0;
424	}
425	if ($in_function_header && /\{$/ ) {
426		if ($picky) {
427			err("opening brace on same line as function header");
428		}
429		$in_function_header = 0;
430		$function_header_full_indent = 0;
431		$in_function = 1;
432		next line;
433	}
434
435	if ($in_warlock_comment && /\*\//) {
436		$in_warlock_comment = 0;
437		$prev = $line;
438		next line;
439	}
440
441	# a blank line terminates the declarations within a function.
442	# XXX - but still a problem in sub-blocks.
443	if ($in_declaration && /^$/) {
444		$in_declaration = 0;
445	}
446
447	if ($comment_done) {
448		$in_comment = 0;
449		$comment_done = 0;
450	}
451	# does this looks like the start of a block comment?
452	if (/$hdr_comment_start/) {
453		if (!/^\t*\/\*/) {
454			err("block comment not indented by tabs");
455		}
456		$in_comment = 1;
457		/^(\s*)\//;
458		$comment_prefix = $1;
459		$prev = $line;
460		next line;
461	}
462	# are we still in the block comment?
463	if ($in_comment) {
464		if (/^$comment_prefix \*\/$/) {
465			$comment_done = 1;
466		} elsif (/\*\//) {
467			$comment_done = 1;
468			err("improper block comment close");
469		} elsif (!/^$comment_prefix \*[ \t]/ &&
470		    !/^$comment_prefix \*$/) {
471			err("improper block comment");
472		}
473	}
474
475	# check for errors that might occur in comments and in code.
476
477	# allow spaces to be used to draw pictures in all comments.
478	if (/[^ ]     / && !/".*     .*"/ && !$in_comment) {
479		err("spaces instead of tabs");
480	}
481	if (/^ / && !/^ \*[ \t\/]/ && !/^ \*$/ &&
482	    (!/^    (\w|\.)/ || $in_function != 0)) {
483		err("indent by spaces instead of tabs");
484	}
485	if (/^\t+ [^ \t\*]/ || /^\t+  \S/ || /^\t+   \S/) {
486		err("continuation line not indented by 4 spaces");
487	}
488	if (/$warlock_re/ && !/\*\//) {
489		$in_warlock_comment = 1;
490		$prev = $line;
491		next line;
492	}
493	if (/^\s*\/\*./ && !/^\s*\/\*.*\*\// && !/$hdr_comment_start/) {
494		err("improper first line of block comment");
495	}
496
497	if ($in_comment) {	# still in comment, don't do further checks
498		$prev = $line;
499		next line;
500	}
501
502	if ((/[^(]\/\*\S/ || /^\/\*\S/) && !/$lint_re/) {
503		err("missing blank after open comment");
504	}
505	if (/\S\*\/[^)]|\S\*\/$/ && !/$lint_re/) {
506		err("missing blank before close comment");
507	}
508	# check for unterminated single line comments, but allow them when
509	# they are used to comment out the argument list of a function
510	# declaration.
511	if (/\S.*\/\*/ && !/\S.*\/\*.*\*\// && !/\(\/\*/) {
512		err("unterminated single line comment");
513	}
514
515	if (/^(#else|#endif|#include)(.*)$/) {
516		$prev = $line;
517		if ($picky) {
518			my $directive = $1;
519			my $clause = $2;
520			# Enforce ANSI rules for #else and #endif: no noncomment
521			# identifiers are allowed after #endif or #else.  Allow
522			# C++ comments since they seem to be a fact of life.
523			if ((($1 eq "#endif") || ($1 eq "#else")) &&
524			    ($clause ne "") &&
525			    (!($clause =~ /^\s+\/\*.*\*\/$/)) &&
526			    (!($clause =~ /^\s+\/\/.*$/))) {
527				err("non-comment text following " .
528				    "$directive (or malformed $directive " .
529				    "directive)");
530			}
531		}
532		next line;
533	}
534
535	#
536	# delete any comments and check everything else.  Note that
537	# ".*?" is a non-greedy match, so that we don't get confused by
538	# multiple comments on the same line.
539	#
540	s/\/\*.*?\*\///g;
541	s/\/\/(?:\s.*)?$//;	# Valid C++ comments
542
543	# After stripping correctly spaced comments, check for (and strip) comments
544	# without a blank.  By checking this after clearing out C++ comments that
545	# correctly have a blank, we guarantee URIs in a C++ comment will not cause
546	# an error.
547	if (s!//.*$!!) {		# C++ comments
548		err("missing blank after start comment");
549	}
550
551	# delete any trailing whitespace; we have already checked for that.
552	s/\s*$//;
553
554	# following checks do not apply to text in comments.
555
556	if (/[^<>\s][!<>=]=/ || /[^<>][!<>=]=[^\s,]/ ||
557	    (/[^->]>[^,=>\s]/ && !/[^->]>$/) ||
558	    (/[^<]<[^,=<\s]/ && !/[^<]<$/) ||
559	    /[^<\s]<[^<]/ || /[^->\s]>[^>]/) {
560		err("missing space around relational operator");
561	}
562	if (/\S>>=/ || /\S<<=/ || />>=\S/ || /<<=\S/ || /\S[-+*\/&|^%]=/ ||
563	    (/[^-+*\/&|^%!<>=\s]=[^=]/ && !/[^-+*\/&|^%!<>=\s]=$/) ||
564	    (/[^!<>=]=[^=\s]/ && !/[^!<>=]=$/)) {
565		# XXX - should only check this for C++ code
566		# XXX - there are probably other forms that should be allowed
567		if (!/\soperator=/) {
568			err("missing space around assignment operator");
569		}
570	}
571	if (/[,;]\S/ && !/\bfor \(;;\)/) {
572		err("comma or semicolon followed by non-blank");
573	}
574	# allow "for" statements to have empty "while" clauses
575	# allow macro invocations to have empty parameters
576	if (/\s[,;]/ && !/^[\t]+;$/ &&
577	    !($in_macro_call || /^\s*for \([^;]*; ;[^;]*\)/)) {
578		err("comma or semicolon preceded by blank");
579	}
580	if (/^\s*(&&|\|\|)/) {
581		err("improper boolean continuation");
582	}
583	if (/\S   *(&&|\|\|)/ || /(&&|\|\|)   *\S/) {
584		err("more than one space around boolean operator");
585	}
586	if (/\b(for|if|while|switch|sizeof|return|case)\(/) {
587		err("missing space between keyword and paren");
588	}
589	if (/(\b(for|if|while|switch|return)\b.*){2,}/ && !/^#define/) {
590		# multiple "case" and "sizeof" allowed
591		err("more than one keyword on line");
592	}
593	if (/\b(for|if|while|switch|sizeof|return|case)\s\s+\(/ &&
594	    !/^#if\s+\(/) {
595		err("extra space between keyword and paren");
596	}
597	# try to detect "func (x)" but not "if (x)" or
598	# "#define foo (x)" or "int (*func)();"
599	if (/\w\s\(/) {
600		my $s = $_;
601		# strip off all keywords on the line
602		s/\b(for|if|while|switch|return|case|sizeof)\s\(/XXX(/g;
603		s/#elif\s\(/XXX(/g;
604		s/^#define\s+\w+\s+\(/XXX(/;
605		# do not match things like "void (*f)();"
606		# or "typedef void (func_t)();"
607		s/\w\s\(+\*/XXX(*/g;
608		s/\b($typename|void)\s+\(+/XXX(/og;
609		if (/\w\s\(/) {
610			err("extra space between function name and left paren");
611		}
612		$_ = $s;
613	}
614	# try to detect "int foo(x)", but not "extern int foo(x);"
615	# XXX - this still trips over too many legitimate things,
616	# like "int foo(x,\n\ty);"
617#		if (/^(\w+(\s|\*)+)+\w+\(/ && !/\)[;,](\s|)*$/ &&
618#		    !/^(extern|static)\b/) {
619#			err("return type of function not on separate line");
620#		}
621	# this is a close approximation
622	if (/^(\w+(\s|\*)+)+\w+\(.*\)(\s|)*$/ &&
623	    !/^(extern|static)\b/) {
624		err("return type of function not on separate line");
625	}
626	if (/^#define /) {
627		err("#define followed by space instead of tab");
628	}
629	if (/^\s*return\W[^;]*;/ && !/^\s*return\s*\(.*\);/) {
630		err("unparenthesized return expression");
631	}
632	if (/\bsizeof\b/ && !/\bsizeof\s*\(.*\)/) {
633		err("unparenthesized sizeof expression");
634	}
635	if (/\(\s/) {
636		err("whitespace after left paren");
637	}
638	# Allow "for" statements to have empty "continue" clauses.
639	# Allow right paren on its own line unless we're being picky (-p).
640	if (/\s\)/ && !/^\s*for \([^;]*;[^;]*; \)/ && ($picky || !/^\s*\)/)) {
641		err("whitespace before right paren");
642	}
643	if (/^\s*\(void\)[^ ]/) {
644		err("missing space after (void) cast");
645	}
646	if (/\S\{/ && !/\{\{/) {
647		err("missing space before left brace");
648	}
649	if ($in_function && /^\s+\{/ &&
650	    ($prev =~ /\)\s*$/ || $prev =~ /\bstruct\s+\w+$/)) {
651		err("left brace starting a line");
652	}
653	if (/\}(else|while)/) {
654		err("missing space after right brace");
655	}
656	if (/\}\s\s+(else|while)/) {
657		err("extra space after right brace");
658	}
659	if (/\b_VOID\b|\bVOID\b|\bSTATIC\b/) {
660		err("obsolete use of VOID or STATIC");
661	}
662	if (/\b$typename\*/o) {
663		err("missing space between type name and *");
664	}
665	if (/^\s+#/) {
666		err("preprocessor statement not in column 1");
667	}
668	if (/^#\s/) {
669		err("blank after preprocessor #");
670	}
671	if (/!\s*(strcmp|strncmp|bcmp)\s*\(/) {
672		err("don't use boolean ! with comparison functions");
673	}
674
675	#
676	# We completely ignore, for purposes of indentation:
677	#  * lines outside of functions
678	#  * preprocessor lines
679	#
680	if ($check_continuation && $in_function && !$in_cpp) {
681		process_indent($_);
682	}
683	if ($picky) {
684		# try to detect spaces after casts, but allow (e.g.)
685		# "sizeof (int) + 1", "void (*funcptr)(int) = foo;", and
686		# "int foo(int) __NORETURN;"
687		if ((/^\($typename( \*+)?\)\s/o ||
688		    /\W\($typename( \*+)?\)\s/o) &&
689		    !/sizeof\s*\($typename( \*)?\)\s/o &&
690		    !/\($typename( \*+)?\)\s+=[^=]/o) {
691			err("space after cast");
692		}
693		if (/\b$typename\s*\*\s/o &&
694		    !/\b$typename\s*\*\s+const\b/o) {
695			err("unary * followed by space");
696		}
697	}
698	if ($check_posix_types && !$in_macro_call) {
699		# try to detect old non-POSIX types.
700		# POSIX requires all non-standard typedefs to end in _t,
701		# but historically these have been used.
702		#
703		# We don't check inside macro invocations because macros have
704		# legitmate uses for these names in function generators.
705		if (/\b(unchar|ushort|uint|ulong|u_int|u_short|u_long|u_char|quad)\b/) {
706			err("non-POSIX typedef $1 used: use $old2posix{$1} instead");
707		}
708	}
709	if (/^\s*else\W/) {
710		if ($prev =~ /^\s*\}$/) {
711			err_prefix($prev,
712			    "else and right brace should be on same line");
713		}
714	}
715
716	# Macro invocations end with a closing paren, and possibly a semicolon.
717	# We do this check down here to make sure all the regular checks are
718	# applied to calls that appear entirely on a single line.
719	if ($in_macro_call && /\);?$/) {
720		$in_macro_call = 0;
721	}
722
723	$prev = $line;
724}
725
726if ($prev eq "") {
727	err("last line in file is blank");
728}
729
730}
731
732#
733# Continuation-line checking
734#
735# The rest of this file contains the code for the continuation checking
736# engine.  It's a pretty simple state machine which tracks the expression
737# depth (unmatched '('s and '['s).
738#
739# Keep in mind that the argument to process_indent() has already been heavily
740# processed; all comments have been replaced by control-A, and the contents of
741# strings and character constants have been elided.
742#
743
744my $cont_in;		# currently inside of a continuation
745my $cont_off;		# skipping an initializer or definition
746my $cont_noerr;		# suppress cascading errors
747my $cont_start;		# the line being continued
748my $cont_base;		# the base indentation
749my $cont_first;		# this is the first line of a statement
750my $cont_multiseg;	# this continuation has multiple segments
751
752my $cont_special;	# this is a C statement (if, for, etc.)
753my $cont_macro;		# this is a macro
754my $cont_case;		# this is a multi-line case
755
756my @cont_paren;		# the stack of unmatched ( and [s we've seen
757
758sub
759reset_indent()
760{
761	$cont_in = 0;
762	$cont_off = 0;
763}
764
765sub
766delabel($)
767{
768	#
769	# replace labels with tabs.  Note that there may be multiple
770	# labels on a line.
771	#
772	local $_ = $_[0];
773
774	while (/^(\t*)( *(?:(?:\w+\s*)|(?:case\b[^:]*)): *)(.*)$/) {
775		my ($pre_tabs, $label, $rest) = ($1, $2, $3);
776		$_ = $pre_tabs;
777		while ($label =~ s/^([^\t]*)(\t+)//) {
778			$_ .= "\t" x (length($2) + length($1) / 8);
779		}
780		$_ .= ("\t" x (length($label) / 8)).$rest;
781	}
782
783	return ($_);
784}
785
786sub
787process_indent($)
788{
789	require strict;
790	local $_ = $_[0];			# preserve the global $_
791
792	s///g;	# No comments
793	s/\s+$//;	# Strip trailing whitespace
794
795	return			if (/^$/);	# skip empty lines
796
797	# regexps used below; keywords taking (), macros, and continued cases
798	my $special = '(?:(?:\}\s*)?else\s+)?(?:if|for|while|switch)\b';
799	my $macro = '[A-Z_][A-Z_0-9]*\(';
800	my $case = 'case\b[^:]*$';
801
802	# skip over enumerations, array definitions, initializers, etc.
803	if ($cont_off <= 0 && !/^\s*$special/ &&
804	    (/(?:(?:\b(?:enum|struct|union)\s*[^\{]*)|(?:\s+=\s*))\{/ ||
805	    (/^\s*\{/ && $prev =~ /=\s*(?:\/\*.*\*\/\s*)*$/))) {
806		$cont_in = 0;
807		$cont_off = tr/{/{/ - tr/}/}/;
808		return;
809	}
810	if ($cont_off) {
811		$cont_off += tr/{/{/ - tr/}/}/;
812		return;
813	}
814
815	if (!$cont_in) {
816		$cont_start = $line;
817
818		if (/^\t* /) {
819			err("non-continuation indented 4 spaces");
820			$cont_noerr = 1;		# stop reporting
821		}
822		$_ = delabel($_);	# replace labels with tabs
823
824		# check if the statement is complete
825		return		if (/^\s*\}?$/);
826		return		if (/^\s*\}?\s*else\s*\{?$/);
827		return		if (/^\s*do\s*\{?$/);
828		return		if (/\{$/);
829		return		if (/\}[,;]?$/);
830
831		# Allow macros on their own lines
832		return		if (/^\s*[A-Z_][A-Z_0-9]*$/);
833
834		# cases we don't deal with, generally non-kosher
835		if (/\{/) {
836			err("stuff after {");
837			return;
838		}
839
840		# Get the base line, and set up the state machine
841		/^(\t*)/;
842		$cont_base = $1;
843		$cont_in = 1;
844		@cont_paren = ();
845		$cont_first = 1;
846		$cont_multiseg = 0;
847
848		# certain things need special processing
849		$cont_special = /^\s*$special/? 1 : 0;
850		$cont_macro = /^\s*$macro/? 1 : 0;
851		$cont_case = /^\s*$case/? 1 : 0;
852	} else {
853		$cont_first = 0;
854
855		# Strings may be pulled back to an earlier (half-)tabstop
856		unless ($cont_noerr || /^$cont_base    / ||
857		    (/^\t*(?:    )?(?:gettext\()?\"/ && !/^$cont_base\t/)) {
858			err_prefix($cont_start,
859			    "continuation should be indented 4 spaces");
860		}
861	}
862
863	my $rest = $_;			# keeps the remainder of the line
864
865	#
866	# The split matches 0 characters, so that each 'special' character
867	# is processed separately.  Parens and brackets are pushed and
868	# popped off the @cont_paren stack.  For normal processing, we wait
869	# until a ; or { terminates the statement.  "special" processing
870	# (if/for/while/switch) is allowed to stop when the stack empties,
871	# as is macro processing.  Case statements are terminated with a :
872	# and an empty paren stack.
873	#
874	foreach $_ (split /[^\(\)\[\]\{\}\;\:]*/) {
875		next		if (length($_) == 0);
876
877		# rest contains the remainder of the line
878		my $rxp = "[^\Q$_\E]*\Q$_\E";
879		$rest =~ s/^$rxp//;
880
881		if (/\(/ || /\[/) {
882			push @cont_paren, $_;
883		} elsif (/\)/ || /\]/) {
884			my $cur = $_;
885			tr/\)\]/\(\[/;
886
887			my $old = (pop @cont_paren);
888			if (!defined($old)) {
889				err("unexpected '$cur'");
890				$cont_in = 0;
891				last;
892			} elsif ($old ne $_) {
893				err("'$cur' mismatched with '$old'");
894				$cont_in = 0;
895				last;
896			}
897
898			#
899			# If the stack is now empty, do special processing
900			# for if/for/while/switch and macro statements.
901			#
902			next		if (@cont_paren != 0);
903			if ($cont_special) {
904				if ($rest =~ /^\s*\{?$/) {
905					$cont_in = 0;
906					last;
907				}
908				if ($rest =~ /^\s*;$/) {
909					err("empty if/for/while body ".
910					    "not on its own line");
911					$cont_in = 0;
912					last;
913				}
914				if (!$cont_first && $cont_multiseg == 1) {
915					err_prefix($cont_start,
916					    "multiple statements continued ".
917					    "over multiple lines");
918					$cont_multiseg = 2;
919				} elsif ($cont_multiseg == 0) {
920					$cont_multiseg = 1;
921				}
922				# We've finished this section, start
923				# processing the next.
924				goto section_ended;
925			}
926			if ($cont_macro) {
927				if ($rest =~ /^$/) {
928					$cont_in = 0;
929					last;
930				}
931			}
932		} elsif (/\;/) {
933			if ($cont_case) {
934				err("unexpected ;");
935			} elsif (!$cont_special) {
936				err("unexpected ;")	if (@cont_paren != 0);
937				if (!$cont_first && $cont_multiseg == 1) {
938					err_prefix($cont_start,
939					    "multiple statements continued ".
940					    "over multiple lines");
941					$cont_multiseg = 2;
942				} elsif ($cont_multiseg == 0) {
943					$cont_multiseg = 1;
944				}
945				if ($rest =~ /^$/) {
946					$cont_in = 0;
947					last;
948				}
949				if ($rest =~ /^\s*special/) {
950					err("if/for/while/switch not started ".
951					    "on its own line");
952				}
953				goto section_ended;
954			}
955		} elsif (/\{/) {
956			err("{ while in parens/brackets") if (@cont_paren != 0);
957			err("stuff after {")		if ($rest =~ /[^\s}]/);
958			$cont_in = 0;
959			last;
960		} elsif (/\}/) {
961			err("} while in parens/brackets") if (@cont_paren != 0);
962			if (!$cont_special && $rest !~ /^\s*(while|else)\b/) {
963				if ($rest =~ /^$/) {
964					err("unexpected }");
965				} else {
966					err("stuff after }");
967				}
968				$cont_in = 0;
969				last;
970			}
971		} elsif (/\:/ && $cont_case && @cont_paren == 0) {
972			err("stuff after multi-line case") if ($rest !~ /$^/);
973			$cont_in = 0;
974			last;
975		}
976		next;
977section_ended:
978		# End of a statement or if/while/for loop.  Reset
979		# cont_special and cont_macro based on the rest of the
980		# line.
981		$cont_special = ($rest =~ /^\s*$special/)? 1 : 0;
982		$cont_macro = ($rest =~ /^\s*$macro/)? 1 : 0;
983		$cont_case = 0;
984		next;
985	}
986	$cont_noerr = 0			if (!$cont_in);
987}
988