xref: /illumos-gate/usr/src/tools/scripts/cstyle.pl (revision c7a0678d)
1#!/usr/bin/perl -w
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 2015 Toomas Soome <tsoome@me.com>
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# Copyright (c) 2015 by Delphix. All rights reserved.
29#
30# @(#)cstyle 1.58 98/09/09 (from shannon)
31#
32# cstyle - check for some common stylistic errors.
33#
34#	cstyle is a sort of "lint" for C coding style.
35#	It attempts to check for the style used in the
36#	kernel, sometimes known as "Bill Joy Normal Form".
37#
38#	There's a lot this can't check for, like proper indentation
39#	of code blocks.  There's also a lot more this could check for.
40#
41#	A note to the non perl literate:
42#
43#		perl regular expressions are pretty much like egrep
44#		regular expressions, with the following special symbols
45#
46#		\s	any space character
47#		\S	any non-space character
48#		\w	any "word" character [a-zA-Z0-9_]
49#		\W	any non-word character
50#		\d	a digit [0-9]
51#		\D	a non-digit
52#		\b	word boundary (between \w and \W)
53#		\B	non-word boundary
54#
55
56require 5.0;
57use IO::File;
58use Getopt::Std;
59use strict;
60
61my $usage =
62"usage: cstyle [-chpvCP] [-o constructs] file ...
63	-c	check continuation indentation inside functions
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-seperated 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("cho:pvCP", \%opts)) {
78	print $usage;
79	exit 2;
80}
81
82my $check_continuation = $opts{'c'};
83my $heuristic = $opts{'h'};
84my $picky = $opts{'p'};
85my $verbose = $opts{'v'};
86my $ignore_hdr_comment = $opts{'C'};
87my $check_posix_types = $opts{'P'};
88
89my $doxygen_comments = 0;
90my $splint_comments = 0;
91
92if (defined($opts{'o'})) {
93	for my $x (split /,/, $opts{'o'}) {
94		if ($x eq "doxygen") {
95			$doxygen_comments = 1;
96		} elsif ($x eq "splint") {
97			$splint_comments = 1;
98		} else {
99			print "cstyle: unrecognized construct \"$x\"\n";
100			print $usage;
101			exit 2;
102		}
103	}
104}
105
106my ($filename, $line, $prev);		# shared globals
107
108my $fmt;
109my $hdr_comment_start;
110
111if ($verbose) {
112	$fmt = "%s: %d: %s\n%s\n";
113} else {
114	$fmt = "%s: %d: %s\n";
115}
116
117if ($doxygen_comments) {
118	# doxygen comments look like "/*!" or "/**"; allow them.
119	$hdr_comment_start = qr/^\s*\/\*[\!\*]?$/;
120} else {
121	$hdr_comment_start = qr/^\s*\/\*$/;
122}
123
124# Note, following must be in single quotes so that \s and \w work right.
125my $typename = '(int|char|short|long|unsigned|float|double' .
126    '|\w+_t|struct\s+\w+|union\s+\w+|FILE)';
127
128# mapping of old types to POSIX compatible types
129my %old2posix = (
130	'unchar' => 'uchar_t',
131	'ushort' => 'ushort_t',
132	'uint' => 'uint_t',
133	'ulong' => 'ulong_t',
134	'u_int' => 'uint_t',
135	'u_short' => 'ushort_t',
136	'u_long' => 'ulong_t',
137	'u_char' => 'uchar_t',
138	'quad' => 'quad_t'
139);
140
141my $lint_re = qr/\/\*(?:
142	ARGSUSED[0-9]*|NOTREACHED|LINTLIBRARY|VARARGS[0-9]*|
143	CONSTCOND|CONSTANTCOND|CONSTANTCONDITION|EMPTY|
144	FALLTHRU|FALLTHROUGH|LINTED.*?|PRINTFLIKE[0-9]*|
145	PROTOLIB[0-9]*|SCANFLIKE[0-9]*|CSTYLED.*?
146    )\*\//x;
147
148my $splint_re = qr/\/\*@.*?@\*\//x;
149
150my $warlock_re = qr/\/\*\s*(?:
151	VARIABLES\ PROTECTED\ BY|
152	MEMBERS\ PROTECTED\ BY|
153	ALL\ MEMBERS\ PROTECTED\ BY|
154	READ-ONLY\ VARIABLES:|
155	READ-ONLY\ MEMBERS:|
156	VARIABLES\ READABLE\ WITHOUT\ LOCK:|
157	MEMBERS\ READABLE\ WITHOUT\ LOCK:|
158	LOCKS\ COVERED\ BY|
159	LOCK\ UNNEEDED\ BECAUSE|
160	LOCK\ NEEDED:|
161	LOCK\ HELD\ ON\ ENTRY:|
162	READ\ LOCK\ HELD\ ON\ ENTRY:|
163	WRITE\ LOCK\ HELD\ ON\ ENTRY:|
164	LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
165	READ\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
166	WRITE\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
167	LOCK\ RELEASED\ AS\ SIDE\ EFFECT:|
168	LOCK\ UPGRADED\ AS\ SIDE\ EFFECT:|
169	LOCK\ DOWNGRADED\ AS\ SIDE\ EFFECT:|
170	FUNCTIONS\ CALLED\ THROUGH\ POINTER|
171	FUNCTIONS\ CALLED\ THROUGH\ MEMBER|
172	LOCK\ ORDER:
173    )/x;
174
175my $err_stat = 0;		# exit status
176
177if ($#ARGV >= 0) {
178	foreach my $arg (@ARGV) {
179		my $fh = new IO::File $arg, "r";
180		if (!defined($fh)) {
181			printf "%s: can not open\n", $arg;
182		} else {
183			&cstyle($arg, $fh);
184			close $fh;
185		}
186	}
187} else {
188	&cstyle("<stdin>", *STDIN);
189}
190exit $err_stat;
191
192my $no_errs = 0;		# set for CSTYLED-protected lines
193
194sub err($) {
195	my ($error) = @_;
196	unless ($no_errs) {
197		if ($verbose) {
198			printf $fmt, $filename, $., $error, $line;
199		} else {
200			printf $fmt, $filename, $., $error;
201		}
202		$err_stat = 1;
203	}
204}
205
206sub err_prefix($$) {
207	my ($prevline, $error) = @_;
208	my $out = $prevline."\n".$line;
209	unless ($no_errs) {
210		if ($verbose) {
211			printf $fmt, $filename, $., $error, $out;
212		} else {
213			printf $fmt, $filename, $., $error;
214		}
215		$err_stat = 1;
216	}
217}
218
219sub err_prev($) {
220	my ($error) = @_;
221	unless ($no_errs) {
222		if ($verbose) {
223			printf $fmt, $filename, $. - 1, $error, $prev;
224		} else {
225			printf $fmt, $filename, $. - 1, $error;
226		}
227		$err_stat = 1;
228	}
229}
230
231sub cstyle($$) {
232
233my ($fn, $filehandle) = @_;
234$filename = $fn;			# share it globally
235
236my $in_cpp = 0;
237my $next_in_cpp = 0;
238
239my $in_comment = 0;
240my $in_header_comment = 0;
241my $comment_done = 0;
242my $in_warlock_comment = 0;
243my $in_function = 0;
244my $in_function_header = 0;
245my $function_header_full_indent = 0;
246my $in_declaration = 0;
247my $note_level = 0;
248my $nextok = 0;
249my $nocheck = 0;
250
251my $in_string = 0;
252
253my ($okmsg, $comment_prefix);
254
255$line = '';
256$prev = '';
257reset_indent();
258
259line: while (<$filehandle>) {
260	s/\r?\n$//;	# strip return and newline
261
262	# save the original line, then remove all text from within
263	# double or single quotes, we do not want to check such text.
264
265	$line = $_;
266
267	#
268	# C allows strings to be continued with a backslash at the end of
269	# the line.  We translate that into a quoted string on the previous
270	# line followed by an initial quote on the next line.
271	#
272	# (we assume that no-one will use backslash-continuation with character
273	# constants)
274	#
275	$_ = '"' . $_		if ($in_string && !$nocheck && !$in_comment);
276
277	#
278	# normal strings and characters
279	#
280	s/'([^\\']|\\[^xX0]|\\0[0-9]*|\\[xX][0-9a-fA-F]*)'/''/g;
281	s/"([^\\"]|\\.)*"/\"\"/g;
282
283	#
284	# detect string continuation
285	#
286	if ($nocheck || $in_comment) {
287		$in_string = 0;
288	} else {
289		#
290		# Now that all full strings are replaced with "", we check
291		# for unfinished strings continuing onto the next line.
292		#
293		$in_string =
294		    (s/([^"](?:"")*)"([^\\"]|\\.)*\\$/$1""/ ||
295		    s/^("")*"([^\\"]|\\.)*\\$/""/);
296	}
297
298	#
299	# figure out if we are in a cpp directive
300	#
301	$in_cpp = $next_in_cpp || /^\s*#/;	# continued or started
302	$next_in_cpp = $in_cpp && /\\$/;	# only if continued
303
304	# strip off trailing backslashes, which appear in long macros
305	s/\s*\\$//;
306
307	# an /* END CSTYLED */ comment ends a no-check block.
308	if ($nocheck) {
309		if (/\/\* *END *CSTYLED *\*\//) {
310			$nocheck = 0;
311		} else {
312			reset_indent();
313			next line;
314		}
315	}
316
317	# a /*CSTYLED*/ comment indicates that the next line is ok.
318	if ($nextok) {
319		if ($okmsg) {
320			err($okmsg);
321		}
322		$nextok = 0;
323		$okmsg = 0;
324		if (/\/\* *CSTYLED.*\*\//) {
325			/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
326			$okmsg = $1;
327			$nextok = 1;
328		}
329		$no_errs = 1;
330	} elsif ($no_errs) {
331		$no_errs = 0;
332	}
333
334	# check length of line.
335	# first, a quick check to see if there is any chance of being too long.
336	if (($line =~ tr/\t/\t/) * 7 + length($line) > 80) {
337		# yes, there is a chance.
338		# replace tabs with spaces and check again.
339		my $eline = $line;
340		1 while $eline =~
341		    s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e;
342		if (length($eline) > 80) {
343			err("line > 80 characters");
344		}
345	}
346
347	# ignore NOTE(...) annotations (assumes NOTE is on lines by itself).
348	if ($note_level || /\b_?NOTE\s*\(/) { # if in NOTE or this is NOTE
349		s/[^()]//g;			  # eliminate all non-parens
350		$note_level += s/\(//g - length;  # update paren nest level
351		next;
352	}
353
354	# a /* BEGIN CSTYLED */ comment starts a no-check block.
355	if (/\/\* *BEGIN *CSTYLED *\*\//) {
356		$nocheck = 1;
357	}
358
359	# a /*CSTYLED*/ comment indicates that the next line is ok.
360	if (/\/\* *CSTYLED.*\*\//) {
361		/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
362		$okmsg = $1;
363		$nextok = 1;
364	}
365	if (/\/\/ *CSTYLED/) {
366		/^.*\/\/ *CSTYLED *(.*)$/;
367		$okmsg = $1;
368		$nextok = 1;
369	}
370
371	# universal checks; apply to everything
372	if (/\t +\t/) {
373		err("spaces between tabs");
374	}
375	if (/ \t+ /) {
376		err("tabs between spaces");
377	}
378	if (/\s$/) {
379		err("space or tab at end of line");
380	}
381	if (/[^ \t(]\/\*/ && !/\w\(\/\*.*\*\/\);/) {
382		err("comment preceded by non-blank");
383	}
384
385	# is this the beginning or ending of a function?
386	# (not if "struct foo\n{\n")
387	if (/^\{$/ && $prev =~ /\)\s*(const\s*)?(\/\*.*\*\/\s*)?\\?$/) {
388		$in_function = 1;
389		$in_declaration = 1;
390		$in_function_header = 0;
391		$function_header_full_indent = 0;
392		$prev = $line;
393		next line;
394	}
395	if (/^\}\s*(\/\*.*\*\/\s*)*$/) {
396		if ($prev =~ /^\s*return\s*;/) {
397			err_prev("unneeded return at end of function");
398		}
399		$in_function = 0;
400		reset_indent();		# we don't check between functions
401		$prev = $line;
402		next line;
403	}
404	if ($in_function_header && ! /^    (\w|\.)/ ) {
405		if (/^\{\}$/) {
406			$in_function_header = 0;
407			$function_header_full_indent = 0;
408		} elsif ($picky && ! (/^\t/ && $function_header_full_indent != 0)) {
409			err("continuation line should be indented by 4 spaces");
410		}
411	}
412
413	#
414	# If this matches something of form "foo(", it's probably a function
415	# definition, unless it ends with ") bar;", in which case it's a declaration
416	# that uses a macro to generate the type.
417	#
418	if (/^\w+\(/ && !/\) \w+;$/) {
419		$in_function_header = 1;
420		if (/\($/) {
421			$function_header_full_indent = 1;
422		}
423	}
424	if ($in_function_header && /^\{$/) {
425		$in_function_header = 0;
426		$function_header_full_indent = 0;
427		$in_function = 1;
428	}
429	if ($in_function_header && /\);$/) {
430		$in_function_header = 0;
431		$function_header_full_indent = 0;
432	}
433	if ($in_function_header && /\{$/ ) {
434		if ($picky) {
435			err("opening brace on same line as function header");
436		}
437		$in_function_header = 0;
438		$function_header_full_indent = 0;
439		$in_function = 1;
440		next line;
441	}
442
443	if ($in_warlock_comment && /\*\//) {
444		$in_warlock_comment = 0;
445		$prev = $line;
446		next line;
447	}
448
449	# a blank line terminates the declarations within a function.
450	# XXX - but still a problem in sub-blocks.
451	if ($in_declaration && /^$/) {
452		$in_declaration = 0;
453	}
454
455	if ($comment_done) {
456		$in_comment = 0;
457		$in_header_comment = 0;
458		$comment_done = 0;
459	}
460	# does this looks like the start of a block comment?
461	if (/$hdr_comment_start/) {
462		if (!/^\t*\/\*/) {
463			err("block comment not indented by tabs");
464		}
465		$in_comment = 1;
466		/^(\s*)\//;
467		$comment_prefix = $1;
468		if ($comment_prefix eq "") {
469			$in_header_comment = 1;
470		}
471		$prev = $line;
472		next line;
473	}
474	# are we still in the block comment?
475	if ($in_comment) {
476		if (/^$comment_prefix \*\/$/) {
477			$comment_done = 1;
478		} elsif (/\*\//) {
479			$comment_done = 1;
480			err("improper block comment close")
481			    unless ($ignore_hdr_comment && $in_header_comment);
482		} elsif (!/^$comment_prefix \*[ \t]/ &&
483		    !/^$comment_prefix \*$/) {
484			err("improper block comment")
485			    unless ($ignore_hdr_comment && $in_header_comment);
486		}
487	}
488
489	if ($in_header_comment && $ignore_hdr_comment) {
490		$prev = $line;
491		next line;
492	}
493
494	# check for errors that might occur in comments and in code.
495
496	# allow spaces to be used to draw pictures in header comments.
497	if (/[^ ]     / && !/".*     .*"/ && !$in_header_comment) {
498		err("spaces instead of tabs");
499	}
500	if (/^ / && !/^ \*[ \t\/]/ && !/^ \*$/ &&
501	    (!/^    (\w|\.)/ || $in_function != 0)) {
502		err("indent by spaces instead of tabs");
503	}
504	if (/^\t+ [^ \t\*]/ || /^\t+  \S/ || /^\t+   \S/) {
505		err("continuation line not indented by 4 spaces");
506	}
507	if (/$warlock_re/ && !/\*\//) {
508		$in_warlock_comment = 1;
509		$prev = $line;
510		next line;
511	}
512	if (/^\s*\/\*./ && !/^\s*\/\*.*\*\// && !/$hdr_comment_start/) {
513		err("improper first line of block comment");
514	}
515
516	if ($in_comment) {	# still in comment, don't do further checks
517		$prev = $line;
518		next line;
519	}
520
521	if ((/[^(]\/\*\S/ || /^\/\*\S/) &&
522	    !(/$lint_re/ || ($splint_comments && /$splint_re/))) {
523		err("missing blank after open comment");
524	}
525	if (/\S\*\/[^)]|\S\*\/$/ &&
526	    !(/$lint_re/ || ($splint_comments && /$splint_re/))) {
527		err("missing blank before close comment");
528	}
529	if (/\/\/\S/) {		# C++ comments
530		err("missing blank after start comment");
531	}
532	# check for unterminated single line comments, but allow them when
533	# they are used to comment out the argument list of a function
534	# declaration.
535	if (/\S.*\/\*/ && !/\S.*\/\*.*\*\// && !/\(\/\*/) {
536		err("unterminated single line comment");
537	}
538
539	if (/^(#else|#endif|#include)(.*)$/) {
540		$prev = $line;
541		if ($picky) {
542			my $directive = $1;
543			my $clause = $2;
544			# Enforce ANSI rules for #else and #endif: no noncomment
545			# identifiers are allowed after #endif or #else.  Allow
546			# C++ comments since they seem to be a fact of life.
547			if ((($1 eq "#endif") || ($1 eq "#else")) &&
548			    ($clause ne "") &&
549			    (!($clause =~ /^\s+\/\*.*\*\/$/)) &&
550			    (!($clause =~ /^\s+\/\/.*$/))) {
551				err("non-comment text following " .
552				    "$directive (or malformed $directive " .
553				    "directive)");
554			}
555		}
556		next line;
557	}
558
559	#
560	# delete any comments and check everything else.  Note that
561	# ".*?" is a non-greedy match, so that we don't get confused by
562	# multiple comments on the same line.
563	#
564	s/\/\*.*?\*\///g;
565	s/\/\/.*$//;		# C++ comments
566
567	# delete any trailing whitespace; we have already checked for that.
568	s/\s*$//;
569
570	# following checks do not apply to text in comments.
571
572	if (/[^<>\s][!<>=]=/ || /[^<>][!<>=]=[^\s,]/ ||
573	    (/[^->]>[^,=>\s]/ && !/[^->]>$/) ||
574	    (/[^<]<[^,=<\s]/ && !/[^<]<$/) ||
575	    /[^<\s]<[^<]/ || /[^->\s]>[^>]/) {
576		err("missing space around relational operator");
577	}
578	if (/\S>>=/ || /\S<<=/ || />>=\S/ || /<<=\S/ || /\S[-+*\/&|^%]=/ ||
579	    (/[^-+*\/&|^%!<>=\s]=[^=]/ && !/[^-+*\/&|^%!<>=\s]=$/) ||
580	    (/[^!<>=]=[^=\s]/ && !/[^!<>=]=$/)) {
581		# XXX - should only check this for C++ code
582		# XXX - there are probably other forms that should be allowed
583		if (!/\soperator=/) {
584			err("missing space around assignment operator");
585		}
586	}
587	if (/[,;]\S/ && !/\bfor \(;;\)/) {
588		err("comma or semicolon followed by non-blank");
589	}
590	# allow "for" statements to have empty "while" clauses
591	if (/\s[,;]/ && !/^[\t]+;$/ && !/^\s*for \([^;]*; ;[^;]*\)/) {
592		err("comma or semicolon preceded by blank");
593	}
594	if (/^\s*(&&|\|\|)/) {
595		err("improper boolean continuation");
596	}
597	if (/\S   *(&&|\|\|)/ || /(&&|\|\|)   *\S/) {
598		err("more than one space around boolean operator");
599	}
600	if (/\b(for|if|while|switch|sizeof|return|case)\(/) {
601		err("missing space between keyword and paren");
602	}
603	if (/(\b(for|if|while|switch|return)\b.*){2,}/ && !/^#define/) {
604		# multiple "case" and "sizeof" allowed
605		err("more than one keyword on line");
606	}
607	if (/\b(for|if|while|switch|sizeof|return|case)\s\s+\(/ &&
608	    !/^#if\s+\(/) {
609		err("extra space between keyword and paren");
610	}
611	# try to detect "func (x)" but not "if (x)" or
612	# "#define foo (x)" or "int (*func)();"
613	if (/\w\s\(/) {
614		my $s = $_;
615		# strip off all keywords on the line
616		s/\b(for|if|while|switch|return|case|sizeof)\s\(/XXX(/g;
617		s/#elif\s\(/XXX(/g;
618		s/^#define\s+\w+\s+\(/XXX(/;
619		# do not match things like "void (*f)();"
620		# or "typedef void (func_t)();"
621		s/\w\s\(+\*/XXX(*/g;
622		s/\b($typename|void)\s+\(+/XXX(/og;
623		if (/\w\s\(/) {
624			err("extra space between function name and left paren");
625		}
626		$_ = $s;
627	}
628	# try to detect "int foo(x)", but not "extern int foo(x);"
629	# XXX - this still trips over too many legitimate things,
630	# like "int foo(x,\n\ty);"
631#		if (/^(\w+(\s|\*)+)+\w+\(/ && !/\)[;,](\s|)*$/ &&
632#		    !/^(extern|static)\b/) {
633#			err("return type of function not on separate line");
634#		}
635	# this is a close approximation
636	if (/^(\w+(\s|\*)+)+\w+\(.*\)(\s|)*$/ &&
637	    !/^(extern|static)\b/) {
638		err("return type of function not on separate line");
639	}
640	if (/^#define /) {
641		err("#define followed by space instead of tab");
642	}
643	if (/^\s*return\W[^;]*;/ && !/^\s*return\s*\(.*\);/) {
644		err("unparenthesized return expression");
645	}
646	if (/\bsizeof\b/ && !/\bsizeof\s*\(.*\)/) {
647		err("unparenthesized sizeof expression");
648	}
649	if (/\(\s/) {
650		err("whitespace after left paren");
651	}
652	# allow "for" statements to have empty "continue" clauses
653	if (/\s\)/ && !/^\s*for \([^;]*;[^;]*; \)/) {
654		err("whitespace before right paren");
655	}
656	if (/^\s*\(void\)[^ ]/) {
657		err("missing space after (void) cast");
658	}
659	if (/\S\{/ && !/\{\{/) {
660		err("missing space before left brace");
661	}
662	if ($in_function && /^\s+\{/ &&
663	    ($prev =~ /\)\s*$/ || $prev =~ /\bstruct\s+\w+$/)) {
664		err("left brace starting a line");
665	}
666	if (/\}(else|while)/) {
667		err("missing space after right brace");
668	}
669	if (/\}\s\s+(else|while)/) {
670		err("extra space after right brace");
671	}
672	if (/\b_VOID\b|\bVOID\b|\bSTATIC\b/) {
673		err("obsolete use of VOID or STATIC");
674	}
675	if (/\b$typename\*/o) {
676		err("missing space between type name and *");
677	}
678	if (/^\s+#/) {
679		err("preprocessor statement not in column 1");
680	}
681	if (/^#\s/) {
682		err("blank after preprocessor #");
683	}
684	if (/!\s*(strcmp|strncmp|bcmp)\s*\(/) {
685		err("don't use boolean ! with comparison functions");
686	}
687
688	#
689	# We completely ignore, for purposes of indentation:
690	#  * lines outside of functions
691	#  * preprocessor lines
692	#
693	if ($check_continuation && $in_function && !$in_cpp) {
694		process_indent($_);
695	}
696	if ($picky) {
697		# try to detect spaces after casts, but allow (e.g.)
698		# "sizeof (int) + 1", "void (*funcptr)(int) = foo;", and
699		# "int foo(int) __NORETURN;"
700		if ((/^\($typename( \*+)?\)\s/o ||
701		    /\W\($typename( \*+)?\)\s/o) &&
702		    !/sizeof\s*\($typename( \*)?\)\s/o &&
703		    !/\($typename( \*+)?\)\s+=[^=]/o) {
704			err("space after cast");
705		}
706		if (/\b$typename\s*\*\s/o &&
707		    !/\b$typename\s*\*\s+const\b/o) {
708			err("unary * followed by space");
709		}
710	}
711	if ($check_posix_types) {
712		# try to detect old non-POSIX types.
713		# POSIX requires all non-standard typedefs to end in _t,
714		# but historically these have been used.
715		if (/\b(unchar|ushort|uint|ulong|u_int|u_short|u_long|u_char|quad)\b/) {
716			err("non-POSIX typedef $1 used: use $old2posix{$1} instead");
717		}
718	}
719	if ($heuristic) {
720		# cannot check this everywhere due to "struct {\n...\n} foo;"
721		if ($in_function && !$in_declaration &&
722		    /\}./ && !/\}\s+=/ && !/\{.*\}[;,]$/ && !/\}(\s|)*$/ &&
723		    !/\} (else|while)/ && !/\}\}/) {
724			err("possible bad text following right brace");
725		}
726		# cannot check this because sub-blocks in
727		# the middle of code are ok
728		if ($in_function && /^\s+\{/) {
729			err("possible left brace starting a line");
730		}
731	}
732	if (/^\s*else\W/) {
733		if ($prev =~ /^\s*\}$/) {
734			err_prefix($prev,
735			    "else and right brace should be on same line");
736		}
737	}
738	$prev = $line;
739}
740
741if ($prev eq "") {
742	err("last line in file is blank");
743}
744
745}
746
747#
748# Continuation-line checking
749#
750# The rest of this file contains the code for the continuation checking
751# engine.  It's a pretty simple state machine which tracks the expression
752# depth (unmatched '('s and '['s).
753#
754# Keep in mind that the argument to process_indent() has already been heavily
755# processed; all comments have been replaced by control-A, and the contents of
756# strings and character constants have been elided.
757#
758
759my $cont_in;		# currently inside of a continuation
760my $cont_off;		# skipping an initializer or definition
761my $cont_noerr;		# suppress cascading errors
762my $cont_start;		# the line being continued
763my $cont_base;		# the base indentation
764my $cont_first;		# this is the first line of a statement
765my $cont_multiseg;	# this continuation has multiple segments
766
767my $cont_special;	# this is a C statement (if, for, etc.)
768my $cont_macro;		# this is a macro
769my $cont_case;		# this is a multi-line case
770
771my @cont_paren;		# the stack of unmatched ( and [s we've seen
772
773sub
774reset_indent()
775{
776	$cont_in = 0;
777	$cont_off = 0;
778}
779
780sub
781delabel($)
782{
783	#
784	# replace labels with tabs.  Note that there may be multiple
785	# labels on a line.
786	#
787	local $_ = $_[0];
788
789	while (/^(\t*)( *(?:(?:\w+\s*)|(?:case\b[^:]*)): *)(.*)$/) {
790		my ($pre_tabs, $label, $rest) = ($1, $2, $3);
791		$_ = $pre_tabs;
792		while ($label =~ s/^([^\t]*)(\t+)//) {
793			$_ .= "\t" x (length($2) + length($1) / 8);
794		}
795		$_ .= ("\t" x (length($label) / 8)).$rest;
796	}
797
798	return ($_);
799}
800
801sub
802process_indent($)
803{
804	require strict;
805	local $_ = $_[0];			# preserve the global $_
806
807	s///g;	# No comments
808	s/\s+$//;	# Strip trailing whitespace
809
810	return			if (/^$/);	# skip empty lines
811
812	# regexps used below; keywords taking (), macros, and continued cases
813	my $special = '(?:(?:\}\s*)?else\s+)?(?:if|for|while|switch)\b';
814	my $macro = '[A-Z_][A-Z_0-9]*\(';
815	my $case = 'case\b[^:]*$';
816
817	# skip over enumerations, array definitions, initializers, etc.
818	if ($cont_off <= 0 && !/^\s*$special/ &&
819	    (/(?:(?:\b(?:enum|struct|union)\s*[^\{]*)|(?:\s+=\s*))\{/ ||
820	    (/^\s*\{/ && $prev =~ /=\s*(?:\/\*.*\*\/\s*)*$/))) {
821		$cont_in = 0;
822		$cont_off = tr/{/{/ - tr/}/}/;
823		return;
824	}
825	if ($cont_off) {
826		$cont_off += tr/{/{/ - tr/}/}/;
827		return;
828	}
829
830	if (!$cont_in) {
831		$cont_start = $line;
832
833		if (/^\t* /) {
834			err("non-continuation indented 4 spaces");
835			$cont_noerr = 1;		# stop reporting
836		}
837		$_ = delabel($_);	# replace labels with tabs
838
839		# check if the statement is complete
840		return		if (/^\s*\}?$/);
841		return		if (/^\s*\}?\s*else\s*\{?$/);
842		return		if (/^\s*do\s*\{?$/);
843		return		if (/\{$/);
844		return		if (/\}[,;]?$/);
845
846		# Allow macros on their own lines
847		return		if (/^\s*[A-Z_][A-Z_0-9]*$/);
848
849		# cases we don't deal with, generally non-kosher
850		if (/\{/) {
851			err("stuff after {");
852			return;
853		}
854
855		# Get the base line, and set up the state machine
856		/^(\t*)/;
857		$cont_base = $1;
858		$cont_in = 1;
859		@cont_paren = ();
860		$cont_first = 1;
861		$cont_multiseg = 0;
862
863		# certain things need special processing
864		$cont_special = /^\s*$special/? 1 : 0;
865		$cont_macro = /^\s*$macro/? 1 : 0;
866		$cont_case = /^\s*$case/? 1 : 0;
867	} else {
868		$cont_first = 0;
869
870		# Strings may be pulled back to an earlier (half-)tabstop
871		unless ($cont_noerr || /^$cont_base    / ||
872		    (/^\t*(?:    )?(?:gettext\()?\"/ && !/^$cont_base\t/)) {
873			err_prefix($cont_start,
874			    "continuation should be indented 4 spaces");
875		}
876	}
877
878	my $rest = $_;			# keeps the remainder of the line
879
880	#
881	# The split matches 0 characters, so that each 'special' character
882	# is processed separately.  Parens and brackets are pushed and
883	# popped off the @cont_paren stack.  For normal processing, we wait
884	# until a ; or { terminates the statement.  "special" processing
885	# (if/for/while/switch) is allowed to stop when the stack empties,
886	# as is macro processing.  Case statements are terminated with a :
887	# and an empty paren stack.
888	#
889	foreach $_ (split /[^\(\)\[\]\{\}\;\:]*/) {
890		next		if (length($_) == 0);
891
892		# rest contains the remainder of the line
893		my $rxp = "[^\Q$_\E]*\Q$_\E";
894		$rest =~ s/^$rxp//;
895
896		if (/\(/ || /\[/) {
897			push @cont_paren, $_;
898		} elsif (/\)/ || /\]/) {
899			my $cur = $_;
900			tr/\)\]/\(\[/;
901
902			my $old = (pop @cont_paren);
903			if (!defined($old)) {
904				err("unexpected '$cur'");
905				$cont_in = 0;
906				last;
907			} elsif ($old ne $_) {
908				err("'$cur' mismatched with '$old'");
909				$cont_in = 0;
910				last;
911			}
912
913			#
914			# If the stack is now empty, do special processing
915			# for if/for/while/switch and macro statements.
916			#
917			next		if (@cont_paren != 0);
918			if ($cont_special) {
919				if ($rest =~ /^\s*\{?$/) {
920					$cont_in = 0;
921					last;
922				}
923				if ($rest =~ /^\s*;$/) {
924					err("empty if/for/while body ".
925					    "not on its own line");
926					$cont_in = 0;
927					last;
928				}
929				if (!$cont_first && $cont_multiseg == 1) {
930					err_prefix($cont_start,
931					    "multiple statements continued ".
932					    "over multiple lines");
933					$cont_multiseg = 2;
934				} elsif ($cont_multiseg == 0) {
935					$cont_multiseg = 1;
936				}
937				# We've finished this section, start
938				# processing the next.
939				goto section_ended;
940			}
941			if ($cont_macro) {
942				if ($rest =~ /^$/) {
943					$cont_in = 0;
944					last;
945				}
946			}
947		} elsif (/\;/) {
948			if ($cont_case) {
949				err("unexpected ;");
950			} elsif (!$cont_special) {
951				err("unexpected ;")	if (@cont_paren != 0);
952				if (!$cont_first && $cont_multiseg == 1) {
953					err_prefix($cont_start,
954					    "multiple statements continued ".
955					    "over multiple lines");
956					$cont_multiseg = 2;
957				} elsif ($cont_multiseg == 0) {
958					$cont_multiseg = 1;
959				}
960				if ($rest =~ /^$/) {
961					$cont_in = 0;
962					last;
963				}
964				if ($rest =~ /^\s*special/) {
965					err("if/for/while/switch not started ".
966					    "on its own line");
967				}
968				goto section_ended;
969			}
970		} elsif (/\{/) {
971			err("{ while in parens/brackets") if (@cont_paren != 0);
972			err("stuff after {")		if ($rest =~ /[^\s}]/);
973			$cont_in = 0;
974			last;
975		} elsif (/\}/) {
976			err("} while in parens/brackets") if (@cont_paren != 0);
977			if (!$cont_special && $rest !~ /^\s*(while|else)\b/) {
978				if ($rest =~ /^$/) {
979					err("unexpected }");
980				} else {
981					err("stuff after }");
982				}
983				$cont_in = 0;
984				last;
985			}
986		} elsif (/\:/ && $cont_case && @cont_paren == 0) {
987			err("stuff after multi-line case") if ($rest !~ /$^/);
988			$cont_in = 0;
989			last;
990		}
991		next;
992section_ended:
993		# End of a statement or if/while/for loop.  Reset
994		# cont_special and cont_macro based on the rest of the
995		# line.
996		$cont_special = ($rest =~ /^\s*$special/)? 1 : 0;
997		$cont_macro = ($rest =~ /^\s*$macro/)? 1 : 0;
998		$cont_case = 0;
999		next;
1000	}
1001	$cont_noerr = 0			if (!$cont_in);
1002}
1003