xref: /freebsd/sys/contrib/openzfs/scripts/cstyle.pl (revision 22649d4dba730d46244fd2dff4fd174903c8379f)
1#!/usr/bin/env perl
2# SPDX-License-Identifier: CDDL-1.0
3#
4# This file and its contents are supplied under the terms of the
5# Common Development and Distribution License ("CDDL"), version 1.0.
6# You may only use this file in accordance with the terms of version
7# 1.0 of the CDDL.
8#
9# A full copy of the text of the CDDL should have accompanied this
10# source.  A copy of the CDDL is also available via the Internet at
11# https://opensource.org/license/CDDL-1.0.
12#
13# Copyright 2016 Nexenta Systems, Inc.
14#
15# Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
16# Use is subject to license terms.
17#
18# @(#)cstyle 1.58 98/09/09 (from shannon)
19#ident	"%Z%%M%	%I%	%E% SMI"
20#
21# cstyle - check for some common stylistic errors.
22#
23#	cstyle is a sort of "lint" for C coding style.
24#	It attempts to check for the style used in the
25#	kernel, sometimes known as "Bill Joy Normal Form".
26#
27#	There's a lot this can't check for, like proper indentation
28#	of code blocks.  There's also a lot more this could check for.
29#
30#	A note to the non perl literate:
31#
32#		perl regular expressions are pretty much like egrep
33#		regular expressions, with the following special symbols
34#
35#		\s	any space character
36#		\S	any non-space character
37#		\w	any "word" character [a-zA-Z0-9_]
38#		\W	any non-word character
39#		\d	a digit [0-9]
40#		\D	a non-digit
41#		\b	word boundary (between \w and \W)
42#		\B	non-word boundary
43#
44
45require 5.0;
46use warnings;
47use IO::File;
48use Getopt::Std;
49use strict;
50
51my $usage =
52"usage: cstyle [-cgpvP] file...
53	-c	check continuation indentation inside functions
54	-g	print github actions' workflow commands
55	-p	perform some of the more picky checks
56	-v	verbose
57	-P	check for use of non-POSIX types
58";
59
60my %opts;
61
62if (!getopts("cghpvCP", \%opts)) {
63	print $usage;
64	exit 2;
65}
66
67my $check_continuation = $opts{'c'};
68my $github_workflow = $opts{'g'} || $ENV{'CI'};
69my $picky = $opts{'p'};
70my $verbose = $opts{'v'};
71my $check_posix_types = $opts{'P'};
72
73my ($filename, $line, $prev);		# shared globals
74
75my $fmt;
76my $hdr_comment_start;
77
78if ($verbose) {
79	$fmt = "%s: %d: %s\n%s\n";
80} else {
81	$fmt = "%s: %d: %s\n";
82}
83
84$hdr_comment_start = qr/^\s*\/\*$/;
85
86# Note, following must be in single quotes so that \s and \w work right.
87my $typename = '(int|char|short|long|unsigned|float|double' .
88    '|\w+_t|struct\s+\w+|union\s+\w+|FILE)';
89
90# cast or compound-literal type, e.g. "(foo_t *)"
91my $cast = qr/\($typename(?: \*+)?\)/;
92
93# mapping of old types to POSIX compatible types
94my %old2posix = (
95	'unchar' => 'uchar_t',
96	'ushort' => 'ushort_t',
97	'uint' => 'uint_t',
98	'ulong' => 'ulong_t',
99	'u_int' => 'uint_t',
100	'u_short' => 'ushort_t',
101	'u_long' => 'ulong_t',
102	'u_char' => 'uchar_t',
103	'quad' => 'quad_t'
104);
105
106my $lint_re = qr/\/\*(?:
107	NOTREACHED|LINTLIBRARY|VARARGS[0-9]*|
108	CONSTCOND|CONSTANTCOND|CONSTANTCONDITION|EMPTY|
109	FALLTHRU|FALLTHROUGH|LINTED.*?|PRINTFLIKE[0-9]*|
110	PROTOLIB[0-9]*|SCANFLIKE[0-9]*|CSTYLED.*?
111    )\*\//x;
112
113my $warlock_re = qr/\/\*\s*(?:
114	VARIABLES\ PROTECTED\ BY|
115	MEMBERS\ PROTECTED\ BY|
116	ALL\ MEMBERS\ PROTECTED\ BY|
117	READ-ONLY\ VARIABLES:|
118	READ-ONLY\ MEMBERS:|
119	VARIABLES\ READABLE\ WITHOUT\ LOCK:|
120	MEMBERS\ READABLE\ WITHOUT\ LOCK:|
121	LOCKS\ COVERED\ BY|
122	LOCK\ UNNEEDED\ BECAUSE|
123	LOCK\ NEEDED:|
124	LOCK\ HELD\ ON\ ENTRY:|
125	READ\ LOCK\ HELD\ ON\ ENTRY:|
126	WRITE\ LOCK\ HELD\ ON\ ENTRY:|
127	LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
128	READ\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
129	WRITE\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
130	LOCK\ RELEASED\ AS\ SIDE\ EFFECT:|
131	LOCK\ UPGRADED\ AS\ SIDE\ EFFECT:|
132	LOCK\ DOWNGRADED\ AS\ SIDE\ EFFECT:|
133	FUNCTIONS\ CALLED\ THROUGH\ POINTER|
134	FUNCTIONS\ CALLED\ THROUGH\ MEMBER|
135	LOCK\ ORDER:
136    )/x;
137
138my $err_stat = 0;		# exit status
139
140if ($#ARGV >= 0) {
141	foreach my $arg (@ARGV) {
142		my $fh = new IO::File $arg, "r";
143		if (!defined($fh)) {
144			printf "%s: can not open\n", $arg;
145		} else {
146			&cstyle($arg, $fh);
147			close $fh;
148		}
149	}
150} else {
151	&cstyle("<stdin>", *STDIN);
152}
153exit $err_stat;
154
155my $no_errs = 0;		# set for CSTYLED-protected lines
156
157sub err($) {
158	my ($error) = @_;
159	unless ($no_errs) {
160		if ($verbose) {
161			printf $fmt, $filename, $., $error, $line;
162		} else {
163			printf $fmt, $filename, $., $error;
164		}
165		if ($github_workflow) {
166			printf "::error file=%s,line=%s::%s\n", $filename, $., $error;
167		}
168		$err_stat = 1;
169	}
170}
171
172sub err_prefix($$) {
173	my ($prevline, $error) = @_;
174	my $out = $prevline."\n".$line;
175	unless ($no_errs) {
176		if ($verbose) {
177			printf $fmt, $filename, $., $error, $out;
178		} else {
179			printf $fmt, $filename, $., $error;
180		}
181		$err_stat = 1;
182	}
183}
184
185sub err_prev($) {
186	my ($error) = @_;
187	unless ($no_errs) {
188		if ($verbose) {
189			printf $fmt, $filename, $. - 1, $error, $prev;
190		} else {
191			printf $fmt, $filename, $. - 1, $error;
192		}
193		$err_stat = 1;
194	}
195}
196
197sub cstyle($$) {
198
199my ($fn, $filehandle) = @_;
200$filename = $fn;			# share it globally
201
202my $in_cpp = 0;
203my $next_in_cpp = 0;
204
205my $in_comment = 0;
206my $comment_done = 0;
207my $in_warlock_comment = 0;
208my $in_macro_call = 0;
209my $in_function = 0;
210my $in_function_header = 0;
211my $function_header_full_indent = 0;
212my $in_declaration = 0;
213my $note_level = 0;
214my $nextok = 0;
215my $nocheck = 0;
216
217my $in_string = 0;
218
219my ($okmsg, $comment_prefix);
220
221$line = '';
222$prev = '';
223reset_indent();
224
225line: while (<$filehandle>) {
226	s/\r?\n$//;	# strip return and newline
227
228	# save the original line, then remove all text from within
229	# double or single quotes, we do not want to check such text.
230
231	$line = $_;
232
233	#
234	# C allows strings to be continued with a backslash at the end of
235	# the line.  We translate that into a quoted string on the previous
236	# line followed by an initial quote on the next line.
237	#
238	# (we assume that no-one will use backslash-continuation with character
239	# constants)
240	#
241	$_ = '"' . $_		if ($in_string && !$nocheck && !$in_comment);
242
243	#
244	# normal strings and characters
245	#
246	s/'([^\\']|\\[^xX0]|\\0[0-9]*|\\[xX][0-9a-fA-F]*)'/''/g;
247	s/"([^\\"]|\\.)*"/\"\"/g;
248
249	#
250	# detect string continuation
251	#
252	if ($nocheck || $in_comment) {
253		$in_string = 0;
254	} else {
255		#
256		# Now that all full strings are replaced with "", we check
257		# for unfinished strings continuing onto the next line.
258		#
259		$in_string =
260		    (s/([^"](?:"")*)"([^\\"]|\\.)*\\$/$1""/ ||
261		    s/^("")*"([^\\"]|\\.)*\\$/""/);
262	}
263
264	#
265	# figure out if we are in a cpp directive
266	#
267	$in_cpp = $next_in_cpp || /^\s*#/;	# continued or started
268	$next_in_cpp = $in_cpp && /\\$/;	# only if continued
269
270	# strip off trailing backslashes, which appear in long macros
271	s/\s*\\$//;
272
273	# an /* END CSTYLED */ comment ends a no-check block.
274	if ($nocheck) {
275		if (/\/\* *END *CSTYLED *\*\//) {
276			$nocheck = 0;
277		} else {
278			reset_indent();
279			next line;
280		}
281	}
282
283	# a /*CSTYLED*/ comment indicates that the next line is ok.
284	if ($nextok) {
285		if ($okmsg) {
286			err($okmsg);
287		}
288		$nextok = 0;
289		$okmsg = 0;
290		if (/\/\* *CSTYLED.*\*\//) {
291			/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
292			$okmsg = $1;
293			$nextok = 1;
294		}
295		$no_errs = 1;
296	} elsif ($no_errs) {
297		$no_errs = 0;
298	}
299
300	# check length of line.
301	# first, a quick check to see if there is any chance of being too long.
302	if (($line =~ tr/\t/\t/) * 7 + length($line) > 80) {
303		# yes, there is a chance.
304		# replace tabs with spaces and check again.
305		my $eline = $line;
306		1 while $eline =~
307		    s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e;
308		if (length($eline) > 80) {
309			err("line > 80 characters");
310		}
311	}
312
313	# ignore NOTE(...) annotations (assumes NOTE is on lines by itself).
314	if ($note_level || /\b_?NOTE\s*\(/) { # if in NOTE or this is NOTE
315		s/[^()]//g;			  # eliminate all non-parens
316		$note_level += s/\(//g - length;  # update paren nest level
317		next;
318	}
319
320	# a /* BEGIN CSTYLED */ comment starts a no-check block.
321	if (/\/\* *BEGIN *CSTYLED *\*\//) {
322		$nocheck = 1;
323	}
324
325	# a /*CSTYLED*/ comment indicates that the next line is ok.
326	if (/\/\* *CSTYLED.*\*\//) {
327		/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
328		$okmsg = $1;
329		$nextok = 1;
330	}
331	if (/\/\/ *CSTYLED/) {
332		/^.*\/\/ *CSTYLED *(.*)$/;
333		$okmsg = $1;
334		$nextok = 1;
335	}
336
337	# universal checks; apply to everything
338	if (/\t +\t/) {
339		err("spaces between tabs");
340	}
341	if (/ \t+ /) {
342		err("tabs between spaces");
343	}
344	if (/\s$/) {
345		err("space or tab at end of line");
346	}
347	if (/[^ \t(]\/\*/ && !/\w\(\/\*.*\*\/\);/) {
348		err("comment preceded by non-blank");
349	}
350	if (/ARGSUSED/) {
351		err("ARGSUSED directive");
352	}
353
354	# is this the beginning or ending of a function?
355	# (not if "struct foo\n{\n")
356	if (/^\{$/ && $prev =~ /\)\s*(const\s*)?(\/\*.*\*\/\s*)?\\?$/) {
357		$in_function = 1;
358		$in_declaration = 1;
359		$in_function_header = 0;
360		$function_header_full_indent = 0;
361		$prev = $line;
362		next line;
363	}
364	if (/^\}\s*(\/\*.*\*\/\s*)*$/) {
365		if ($prev =~ /^\s*return\s*;/) {
366			err_prev("unneeded return at end of function");
367		}
368		$in_function = 0;
369		reset_indent();		# we don't check between functions
370		$prev = $line;
371		next line;
372	}
373	if ($in_function_header && ! /^    (\w|\.)/ ) {
374		if (/^\{\}$/ # empty functions
375		|| /;/ #run function with multiline arguments
376		|| /#/ #preprocessor commands
377		|| /^[^\s\\]*\(.*\)$/ #functions without ; at the end
378		|| /^$/ #function declaration can't have empty line
379		) {
380			$in_function_header = 0;
381			$function_header_full_indent = 0;
382		} elsif ($prev =~ /^__attribute__/) { #__attribute__((*))
383			$in_function_header = 0;
384			$function_header_full_indent = 0;
385			$prev = $line;
386			next line;
387		} elsif ($picky	&& ! (/^\t/ && $function_header_full_indent != 0)) {
388
389			err("continuation line should be indented by 4 spaces");
390		}
391	}
392
393	# If this looks like a top-level macro invocation, remember it so we
394	# don't mistake it for a function declaration below.
395	if (/^[A-Za-z_][A-Za-z_0-9]*\(/) {
396		$in_macro_call = 1;
397	}
398
399	#
400	# If this matches something of form "foo(", it's probably a function
401	# definition, unless it ends with ") bar;", in which case it's a declaration
402	# that uses a macro to generate the type.
403	#
404	if (!$in_macro_call && /^\w+\(/ && !/\) \w+;/) {
405		$in_function_header = 1;
406		if (/\($/) {
407			$function_header_full_indent = 1;
408		}
409	}
410	if ($in_function_header && /^\{$/) {
411		$in_function_header = 0;
412		$function_header_full_indent = 0;
413		$in_function = 1;
414	}
415	if ($in_function_header && /\);$/) {
416		$in_function_header = 0;
417		$function_header_full_indent = 0;
418	}
419	if ($in_function_header && /\{$/ ) {
420		if ($picky) {
421			err("opening brace on same line as function header");
422		}
423		$in_function_header = 0;
424		$function_header_full_indent = 0;
425		$in_function = 1;
426		next line;
427	}
428
429	if ($in_warlock_comment && /\*\//) {
430		$in_warlock_comment = 0;
431		$prev = $line;
432		next line;
433	}
434
435	# a blank line terminates the declarations within a function.
436	# XXX - but still a problem in sub-blocks.
437	if ($in_declaration && /^$/) {
438		$in_declaration = 0;
439	}
440
441	if ($comment_done) {
442		$in_comment = 0;
443		$comment_done = 0;
444	}
445	# does this looks like the start of a block comment?
446	if (/$hdr_comment_start/) {
447		if (!/^\t*\/\*/) {
448			err("block comment not indented by tabs");
449		}
450		$in_comment = 1;
451		/^(\s*)\//;
452		$comment_prefix = $1;
453		$prev = $line;
454		next line;
455	}
456	# are we still in the block comment?
457	if ($in_comment) {
458		if (/^$comment_prefix \*\/$/) {
459			$comment_done = 1;
460		} elsif (/\*\//) {
461			$comment_done = 1;
462			err("improper block comment close");
463		} elsif (!/^$comment_prefix \*[ \t]/ &&
464		    !/^$comment_prefix \*$/) {
465			err("improper block comment");
466		}
467	}
468
469	# check for errors that might occur in comments and in code.
470
471	# allow spaces to be used to draw pictures in all comments.
472	if (/[^ ]     / && !/".*     .*"/ && !$in_comment) {
473		err("spaces instead of tabs");
474	}
475	if (/^ / && !/^ \*[ \t\/]/ && !/^ \*$/ &&
476	    (!/^    (\w|\.)/ || $in_function != 0)) {
477		err("indent by spaces instead of tabs");
478	}
479	if (/^\t+ [^ \t\*]/ || /^\t+  \S/ || /^\t+   \S/) {
480		err("continuation line not indented by 4 spaces");
481	}
482	if (/$warlock_re/ && !/\*\//) {
483		$in_warlock_comment = 1;
484		$prev = $line;
485		next line;
486	}
487	if (/^\s*\/\*./ && !/^\s*\/\*.*\*\// && !/$hdr_comment_start/) {
488		err("improper first line of block comment");
489	}
490
491	if ($in_comment) {	# still in comment, don't do further checks
492		$prev = $line;
493		next line;
494	}
495
496	if ((/[^(]\/\*\S/ || /^\/\*\S/) && !/$lint_re/) {
497		err("missing blank after open comment");
498	}
499	if (/\S\*\/[^)]|\S\*\/$/ && !/$lint_re/) {
500		err("missing blank before close comment");
501	}
502	# check for unterminated single line comments, but allow them when
503	# they are used to comment out the argument list of a function
504	# declaration.
505	if (/\S.*\/\*/ && !/\S.*\/\*.*\*\// && !/\(\/\*/) {
506		err("unterminated single line comment");
507	}
508
509	if (/^(#else|#endif|#include)(.*)$/) {
510		$prev = $line;
511		if ($picky) {
512			my $directive = $1;
513			my $clause = $2;
514			# Enforce ANSI rules for #else and #endif: no noncomment
515			# identifiers are allowed after #endif or #else.  Allow
516			# C++ comments since they seem to be a fact of life.
517			if ((($1 eq "#endif") || ($1 eq "#else")) &&
518			    ($clause ne "") &&
519			    (!($clause =~ /^\s+\/\*.*\*\/$/)) &&
520			    (!($clause =~ /^\s+\/\/.*$/))) {
521				err("non-comment text following " .
522				    "$directive (or malformed $directive " .
523				    "directive)");
524			}
525		}
526		next line;
527	}
528
529	#
530	# delete any comments and check everything else.  Note that
531	# ".*?" is a non-greedy match, so that we don't get confused by
532	# multiple comments on the same line.
533	#
534	s/\/\*.*?\*\///g;
535	s/\/\/(?:\s.*)?$//;	# Valid C++ comments
536
537	# After stripping correctly spaced comments, check for (and strip) comments
538	# without a blank.  By checking this after clearing out C++ comments that
539	# correctly have a blank, we guarantee URIs in a C++ comment will not cause
540	# an error.
541	if (s!//.*$!!) {		# C++ comments
542		err("missing blank after start comment");
543	}
544
545	# delete any trailing whitespace; we have already checked for that.
546	s/\s*$//;
547
548	# following checks do not apply to text in comments.
549
550	if (/[^<>\s][!<>=]=/ || /[^<>][!<>=]=[^\s,]/ ||
551	    (/[^->]>[^,=>\s]/ && !/[^->]>$/) ||
552	    (/[^<]<[^,=<\s]/ && !/[^<]<$/) ||
553	    /[^<\s]<[^<]/ || /[^->\s]>[^>]/) {
554		err("missing space around relational operator");
555	}
556	if (/\S>>=/ || /\S<<=/ || />>=\S/ || /<<=\S/ || /\S[-+*\/&|^%]=/ ||
557	    (/[^-+*\/&|^%!<>=\s]=[^=]/ && !/[^-+*\/&|^%!<>=\s]=$/) ||
558	    (/[^!<>=]=[^=\s]/ && !/[^!<>=]=$/)) {
559		# XXX - should only check this for C++ code
560		# XXX - there are probably other forms that should be allowed
561		if (!/\soperator=/) {
562			err("missing space around assignment operator");
563		}
564	}
565	if (/[,;]\S/ && !/\bfor \(;;\)/) {
566		err("comma or semicolon followed by non-blank");
567	}
568	# allow "for" statements to have empty "while" clauses
569	# allow macro invocations to have empty parameters
570	if (/\s[,;]/ && !/^[\t]+;$/ &&
571	    !($in_macro_call || /^\s*for \([^;]*; ;[^;]*\)/)) {
572		err("comma or semicolon preceded by blank");
573	}
574	if (/^\s*(&&|\|\|)/) {
575		err("improper boolean continuation");
576	}
577	if (/\S   *(&&|\|\|)/ || /(&&|\|\|)   *\S/) {
578		err("more than one space around boolean operator");
579	}
580	if (/\b(for|if|while|switch|sizeof|return|case)\(/) {
581		err("missing space between keyword and paren");
582	}
583	if (/(\b(for|if|while|switch|return)\b.*){2,}/ && !/^#define/) {
584		# multiple "case" and "sizeof" allowed
585		err("more than one keyword on line");
586	}
587	if (/\b(for|if|while|switch|sizeof|return|case)\s\s+\(/ &&
588	    !/^#if\s+\(/) {
589		err("extra space between keyword and paren");
590	}
591	# try to detect "func (x)" but not "if (x)" or
592	# "#define foo (x)" or "int (*func)();"
593	if (/\w\s\(/) {
594		my $s = $_;
595		# strip off all keywords on the line
596		s/\b(for|if|while|switch|return|case|sizeof)\s\(/XXX(/g;
597		s/#elif\s\(/XXX(/g;
598		s/^#define\s+\w+\s+\(/XXX(/;
599		# do not match things like "void (*f)();"
600		# or "typedef void (func_t)();"
601		s/\w\s\(+\*/XXX(*/g;
602		s/\b($typename|void)\s+\(+/XXX(/og;
603		if (/\w\s\(/) {
604			err("extra space between function name and left paren");
605		}
606		$_ = $s;
607	}
608	# try to detect "int foo(x)", but not "extern int foo(x);"
609	# XXX - this still trips over too many legitimate things,
610	# like "int foo(x,\n\ty);"
611#		if (/^(\w+(\s|\*)+)+\w+\(/ && !/\)[;,](\s|)*$/ &&
612#		    !/^(extern|static)\b/) {
613#			err("return type of function not on separate line");
614#		}
615	# this is a close approximation
616	if (/^(\w+(\s|\*)+)+\w+\(.*\)(\s|)*$/ &&
617	    !/^(extern|static)\b/) {
618		err("return type of function not on separate line");
619	}
620	if (/^#define /) {
621		err("#define followed by space instead of tab");
622	}
623	if (/^\s*return\W[^;]*;/ && !/^\s*return\s*\(.*\);/) {
624		err("unparenthesized return expression");
625	}
626	if (/\bsizeof\b/ && !/\bsizeof\s*\(.*\)/) {
627		err("unparenthesized sizeof expression");
628	}
629	if (/\(\s/) {
630		err("whitespace after left paren");
631	}
632	# Allow "for" statements to have empty "continue" clauses.
633	# Allow right paren on its own line unless we're being picky (-p).
634	if (/\s\)/ && !/^\s*for \([^;]*;[^;]*; \)/ && ($picky || !/^\s*\)/)) {
635		err("whitespace before right paren");
636	}
637	if (/^\s*\(void\)[^ ]/) {
638		err("missing space after (void) cast");
639	}
640	if (/\S\{/ && !/\{\{/) {
641		err("missing space before left brace");
642	}
643	if ($in_function && /^\s+\{/ &&
644	    ($prev =~ /\)\s*$/ || $prev =~ /\bstruct\s+\w+$/)) {
645		err("left brace starting a line");
646	}
647	if (/\}(else|while)/) {
648		err("missing space after right brace");
649	}
650	if (/\}\s\s+(else|while)/) {
651		err("extra space after right brace");
652	}
653	if (/\b_VOID\b|\bVOID\b|\bSTATIC\b/) {
654		err("obsolete use of VOID or STATIC");
655	}
656	if (/\b$typename\*/o) {
657		err("missing space between type name and *");
658	}
659	if (/^\s+#/) {
660		err("preprocessor statement not in column 1");
661	}
662	if (/^#\s/) {
663		err("blank after preprocessor #");
664	}
665	if (/!\s*(strcmp|strncmp|bcmp)\s*\(/) {
666		err("don't use boolean ! with comparison functions");
667	}
668
669	#
670	# We completely ignore, for purposes of indentation:
671	#  * lines outside of functions
672	#  * preprocessor lines
673	#
674	if ($check_continuation && $in_function && !$in_cpp) {
675		process_indent($_);
676	}
677	if ($picky) {
678		# try to detect spaces after casts, but allow (e.g.)
679		# "sizeof (int) + 1", "void (*funcptr)(int) = foo;",
680		# "int foo(int) __NORETURN;", and "(foo_t) { ... }"
681		#
682		# sizeof (type) is not a cast; remove it so it can't mask
683		# a real cast elsewhere on the line.
684		my $tmp = $_;
685		$tmp =~ s/\bsizeof\s*$cast/sizeof/g;
686		if ($tmp =~ /(?:^|\W)$cast(?>\s+)(?!\{|=[^=])/) {
687			err("space after cast");
688		}
689		if (/\b$typename\s*\*\s/o &&
690		    !/\b$typename\s*\*\s+const\b/o) {
691			err("unary * followed by space");
692		}
693	}
694	if ($check_posix_types && !$in_macro_call) {
695		# try to detect old non-POSIX types.
696		# POSIX requires all non-standard typedefs to end in _t,
697		# but historically these have been used.
698		#
699		# We don't check inside macro invocations because macros have
700		# legitmate uses for these names in function generators.
701		if (/\b(unchar|ushort|uint|ulong|u_int|u_short|u_long|u_char|quad)\b/) {
702			err("non-POSIX typedef $1 used: use $old2posix{$1} instead");
703		}
704	}
705	if (/^\s*else\W/) {
706		if ($prev =~ /^\s*\}$/) {
707			err_prefix($prev,
708			    "else and right brace should be on same line");
709		}
710	}
711
712	# Macro invocations end with a closing paren, and possibly a semicolon.
713	# We do this check down here to make sure all the regular checks are
714	# applied to calls that appear entirely on a single line.
715	if ($in_macro_call && /\);?$/) {
716		$in_macro_call = 0;
717	}
718
719	$prev = $line;
720}
721
722if ($prev eq "") {
723	err("last line in file is blank");
724}
725
726}
727
728#
729# Continuation-line checking
730#
731# The rest of this file contains the code for the continuation checking
732# engine.  It's a pretty simple state machine which tracks the expression
733# depth (unmatched '('s and '['s).
734#
735# Keep in mind that the argument to process_indent() has already been heavily
736# processed; all comments have been replaced by control-A, and the contents of
737# strings and character constants have been elided.
738#
739
740my $cont_in;		# currently inside of a continuation
741my $cont_off;		# skipping an initializer or definition
742my $cont_noerr;		# suppress cascading errors
743my $cont_start;		# the line being continued
744my $cont_base;		# the base indentation
745my $cont_first;		# this is the first line of a statement
746my $cont_multiseg;	# this continuation has multiple segments
747
748my $cont_special;	# this is a C statement (if, for, etc.)
749my $cont_macro;		# this is a macro
750my $cont_case;		# this is a multi-line case
751
752my @cont_paren;		# the stack of unmatched ( and [s we've seen
753
754sub
755reset_indent()
756{
757	$cont_in = 0;
758	$cont_off = 0;
759}
760
761sub
762delabel($)
763{
764	#
765	# replace labels with tabs.  Note that there may be multiple
766	# labels on a line.
767	#
768	local $_ = $_[0];
769
770	while (/^(\t*)( *(?:(?:\w+\s*)|(?:case\b[^:]*)): *)(.*)$/) {
771		my ($pre_tabs, $label, $rest) = ($1, $2, $3);
772		$_ = $pre_tabs;
773		while ($label =~ s/^([^\t]*)(\t+)//) {
774			$_ .= "\t" x (length($2) + length($1) / 8);
775		}
776		$_ .= ("\t" x (length($label) / 8)).$rest;
777	}
778
779	return ($_);
780}
781
782sub
783process_indent($)
784{
785	require strict;
786	local $_ = $_[0];			# preserve the global $_
787
788	s///g;	# No comments
789	s/\s+$//;	# Strip trailing whitespace
790
791	return			if (/^$/);	# skip empty lines
792
793	# regexps used below; keywords taking (), macros, and continued cases
794	my $special = '(?:(?:\}\s*)?else\s+)?(?:if|for|while|switch)\b';
795	my $macro = '[A-Z_][A-Z_0-9]*\(';
796	my $case = 'case\b[^:]*$';
797
798	# skip over enumerations, array definitions, initializers, etc.
799	if ($cont_off <= 0 && !/^\s*$special/) {
800		my $aggregate = /\b(?:enum|struct|union)\s*[^{]*\{/;
801		my $initializer = /\s+=\s*(?:$cast\s*)?\{/;
802		# "= {" split across lines, "=" possibly trailed by comments
803		my $split_init = /^\s*\{/ &&
804		    $prev =~ /=\s*(?:$cast\s*)?(?:\/\*.*\*\/\s*)?$/;
805
806		if ($aggregate || $initializer || $split_init) {
807			$cont_in = 0;
808			$cont_off = tr/{/{/ - tr/}/}/;
809			return;
810		}
811	}
812	if ($cont_off) {
813		$cont_off += tr/{/{/ - tr/}/}/;
814		return;
815	}
816
817	if (!$cont_in) {
818		$cont_start = $line;
819
820		if (/^\t* /) {
821			err("non-continuation indented 4 spaces");
822			$cont_noerr = 1;		# stop reporting
823		}
824		$_ = delabel($_);	# replace labels with tabs
825
826		# check if the statement is complete
827		return		if (/^\s*\}?$/);
828		return		if (/^\s*\}?\s*else\s*\{?$/);
829		return		if (/^\s*do\s*\{?$/);
830		return		if (/\{$/);
831		return		if (/\}[,;]?$/);
832
833		# Allow macros on their own lines
834		return		if (/^\s*[A-Z_][A-Z_0-9]*$/);
835
836		# cases we don't deal with, generally non-kosher
837		if (/\{/) {
838			err("stuff after {");
839			return;
840		}
841
842		# Get the base line, and set up the state machine
843		/^(\t*)/;
844		$cont_base = $1;
845		$cont_in = 1;
846		@cont_paren = ();
847		$cont_first = 1;
848		$cont_multiseg = 0;
849
850		# certain things need special processing
851		$cont_special = /^\s*$special/? 1 : 0;
852		$cont_macro = /^\s*$macro/? 1 : 0;
853		$cont_case = /^\s*$case/? 1 : 0;
854	} else {
855		$cont_first = 0;
856
857		# Strings may be pulled back to an earlier (half-)tabstop
858		unless ($cont_noerr || /^$cont_base    / ||
859		    (/^\t*(?:    )?(?:gettext\()?\"/ && !/^$cont_base\t/)) {
860			err_prefix($cont_start,
861			    "continuation should be indented 4 spaces");
862		}
863	}
864
865	my $rest = $_;			# keeps the remainder of the line
866
867	#
868	# The split matches 0 characters, so that each 'special' character
869	# is processed separately.  Parens and brackets are pushed and
870	# popped off the @cont_paren stack.  For normal processing, we wait
871	# until a ; or { terminates the statement.  "special" processing
872	# (if/for/while/switch) is allowed to stop when the stack empties,
873	# as is macro processing.  Case statements are terminated with a :
874	# and an empty paren stack.
875	#
876	foreach $_ (split /[^\(\)\[\]\{\}\;\:]*/) {
877		next		if (length($_) == 0);
878
879		# rest contains the remainder of the line
880		my $rxp = "[^\Q$_\E]*\Q$_\E";
881		$rest =~ s/^$rxp//;
882
883		if (/\(/ || /\[/) {
884			push @cont_paren, $_;
885		} elsif (/\)/ || /\]/) {
886			my $cur = $_;
887			tr/\)\]/\(\[/;
888
889			my $old = (pop @cont_paren);
890			if (!defined($old)) {
891				err("unexpected '$cur'");
892				$cont_in = 0;
893				last;
894			} elsif ($old ne $_) {
895				err("'$cur' mismatched with '$old'");
896				$cont_in = 0;
897				last;
898			}
899
900			#
901			# If the stack is now empty, do special processing
902			# for if/for/while/switch and macro statements.
903			#
904			next		if (@cont_paren != 0);
905			if ($cont_special) {
906				if ($rest =~ /^\s*\{?$/) {
907					$cont_in = 0;
908					last;
909				}
910				if ($rest =~ /^\s*;$/) {
911					err("empty if/for/while body ".
912					    "not on its own line");
913					$cont_in = 0;
914					last;
915				}
916				if (!$cont_first && $cont_multiseg == 1) {
917					err_prefix($cont_start,
918					    "multiple statements continued ".
919					    "over multiple lines");
920					$cont_multiseg = 2;
921				} elsif ($cont_multiseg == 0) {
922					$cont_multiseg = 1;
923				}
924				# We've finished this section, start
925				# processing the next.
926				goto section_ended;
927			}
928			if ($cont_macro) {
929				if ($rest =~ /^$/) {
930					$cont_in = 0;
931					last;
932				}
933			}
934		} elsif (/\;/) {
935			if ($cont_case) {
936				err("unexpected ;");
937			} elsif (!$cont_special) {
938				err("unexpected ;")	if (@cont_paren != 0);
939				if (!$cont_first && $cont_multiseg == 1) {
940					err_prefix($cont_start,
941					    "multiple statements continued ".
942					    "over multiple lines");
943					$cont_multiseg = 2;
944				} elsif ($cont_multiseg == 0) {
945					$cont_multiseg = 1;
946				}
947				if ($rest =~ /^$/) {
948					$cont_in = 0;
949					last;
950				}
951				if ($rest =~ /^\s*special/) {
952					err("if/for/while/switch not started ".
953					    "on its own line");
954				}
955				goto section_ended;
956			}
957		} elsif (/\{/) {
958			err("{ while in parens/brackets") if (@cont_paren != 0);
959			err("stuff after {")		if ($rest =~ /[^\s}]/);
960			$cont_in = 0;
961			last;
962		} elsif (/\}/) {
963			err("} while in parens/brackets") if (@cont_paren != 0);
964			if (!$cont_special && $rest !~ /^\s*(while|else)\b/) {
965				if ($rest =~ /^$/) {
966					err("unexpected }");
967				} else {
968					err("stuff after }");
969				}
970				$cont_in = 0;
971				last;
972			}
973		} elsif (/\:/ && $cont_case && @cont_paren == 0) {
974			err("stuff after multi-line case") if ($rest !~ /$^/);
975			$cont_in = 0;
976			last;
977		}
978		next;
979section_ended:
980		# End of a statement or if/while/for loop.  Reset
981		# cont_special and cont_macro based on the rest of the
982		# line.
983		$cont_special = ($rest =~ /^\s*$special/)? 1 : 0;
984		$cont_macro = ($rest =~ /^\s*$macro/)? 1 : 0;
985		$cont_case = 0;
986		next;
987	}
988	$cont_noerr = 0			if (!$cont_in);
989}
990