5 files changed, 1122 insertions, 2 deletions

diff --git a/Makefile.am b/Makefile.am
index 9c299a9ef..6c808b662 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -40,6 +40,9 @@ dist-hook:
 	sed -i 's/Release:[[:print:]]*/Release:      $(RELEASE)/' \
 		$(distdir)/META
 
+checkstyle:
+	find ${top_srcdir} -name '*.[hc]' -type f -exec scripts/cstyle.pl {} \;
+
 ctags:
 	$(RM) $(top_srcdir)/tags
 	find $(top_srcdir) -name .git -prune -o -name '*.[hc]' | xargs ctags
diff --git a/man/man1/Makefile.am b/man/man1/Makefile.am
index 9d4439817..476aeed54 100644
--- a/man/man1/Makefile.am
+++ b/man/man1/Makefile.am
@@ -1,5 +1,5 @@
 man_MANS = zhack.1 zpios.1 ztest.1
-EXTRA_DIST = $(man_MANS)
+EXTRA_DIST = $(man_MANS) cstyle.1
 
 install-data-local:
 	$(INSTALL) -d -m 0755 "$(DESTDIR)$(mandir)/man1"
diff --git a/man/man1/cstyle.1 b/man/man1/cstyle.1
new file mode 100644
index 000000000..f467c55d4
--- /dev/null
+++ b/man/man1/cstyle.1
@@ -0,0 +1,167 @@
+.\" Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+.\" Use is subject to license terms.
+.\"
+.\" CDDL HEADER START
+.\"
+.\" The contents of this file are subject to the terms of the
+.\" Common Development and Distribution License (the "License").
+.\" You may not use this file except in compliance with the License.
+.\"
+.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+.\" or http://www.opensolaris.org/os/licensing.
+.\" See the License for the specific language governing permissions
+.\" and limitations under the License.
+.\"
+.\" When distributing Covered Code, include this CDDL HEADER in each
+.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+.\" If applicable, add the following below this CDDL HEADER, with the
+.\" fields enclosed by brackets "[]" replaced with your own identifying
+.\" information: Portions Copyright [yyyy] [name of copyright owner]
+.\"
+.\" CDDL HEADER END
+.\"
+.TH cstyle 1 "28 March 2005"
+.SH NAME
+.I cstyle
+\- check for some common stylistic errors in C source files
+.SH SYNOPSIS
+\fBcstyle [-chpvCP] [-o constructs] [file...]\fP
+.LP
+.SH DESCRIPTION
+.IX "OS-Net build tools" "cstyle" "" "\fBcstyle\fP"
+.LP
+.I cstyle
+inspects C source files (*.c and *.h) for common sylistic errors.  It
+attempts to check for the cstyle documented in
+\fIhttp://www.cis.upenn.edu/~lee/06cse480/data/cstyle.ms.pdf\fP.
+Note that there is much in that document that
+.I cannot
+be checked for; just because your code is \fBcstyle(1)\fP clean does not
+mean that you've followed Sun's C style.  \fICaveat emptor\fP.
+.LP
+.SH OPTIONS
+.LP
+The following options are supported:
+.TP 4
+.B \-c
+Check continuation line indentation inside of functions.  Sun's C style
+states that all statements must be indented to an appropriate tab stop,
+and any continuation lines after them must be indented \fIexactly\fP four
+spaces from the start line.  This option enables a series of checks
+designed to find contination line problems within functions only.  The
+checks have some limitations;  see CONTINUATION CHECKING, below.
+.LP
+.TP 4
+.B \-h
+Performs heuristic checks that are sometimes wrong.  Not generally used.
+.LP
+.TP 4
+.B \-p
+Performs some of the more picky checks.  Includes ANSI #else and #endif
+rules, and tries to detect spaces after casts.  Used as part of the
+putback checks.
+.LP
+.TP 4
+.B \-v
+Verbose output;  includes the text of the line of error, and, for
+\fB-c\fP, the first statement in the current continuation block.
+.LP
+.TP 4
+.B \-C
+Ignore errors in header comments (i.e. block comments starting in the
+first column).  Not generally used.
+.LP
+.TP 4
+.B \-P
+Check for use of non-POSIX types.  Historically, types like "u_int" and
+"u_long" were used, but they are now deprecated in favor of the POSIX
+types uint_t, ulong_t, etc.  This detects any use of the deprecated
+types.  Used as part of the putback checks.
+.LP
+.TP 4
+.B \-o \fIconstructs\fP
+Allow a comma-seperated list of additional constructs.  Available
+constructs include:
+.LP
+.TP 10
+.B doxygen
+Allow doxygen-style block comments (\fB/**\fP and \fB/*!\fP)
+.LP
+.TP 10
+.B splint
+Allow splint-style lint comments (\fB/*@...@*/\fP)
+.LP
+.SH NOTES
+.LP
+The cstyle rule for the OS/Net consolidation is that all new files must
+be \fB-pP\fP clean.  For existing files, the following invocations are
+run against both the old and new files:
+.LP
+.TP 4
+\fBcstyle file\fB
+.LP
+.TP 4
+\fBcstyle -p file\fB
+.LP
+.TP 4
+\fBcstyle -pP file\fB
+.LP
+If the old file gave no errors for one of the invocations, the new file
+must also give no errors.  This way, files can only become more clean.
+.LP
+.SH CONTINUATION CHECKING
+.LP
+The continuation checker is a resonably simple state machine that knows
+something about how C is layed out, and can match parenthesis, etc. over
+multiple lines.  It does have some limitations:
+.LP
+.TP 4
+.B 1.
+Preprocessor macros which cause unmatched parenthesis will confuse the
+checker for that line.  To fix this, you'll need to make sure that each
+branch of the #if statement has balanced parenthesis.
+.LP
+.TP 4
+.B 2.
+Some \fBcpp\fP macros do not require ;s after them.  Any such macros
+*must* be ALL_CAPS; any lower case letters will cause bad output.
+.LP
+The bad output will generally be corrected after the next \fB;\fP,
+\fB{\fP, or \fB}\fP.
+.LP
+Some continuation error messages deserve some additional explanation
+.LP
+.TP 4
+.B
+multiple statements continued over multiple lines
+A multi-line statement which is not broken at statement
+boundries.  For example:
+.RS 4
+.HP 4
+if (this_is_a_long_variable == another_variable) a =
+.br
+b + c;
+.LP
+Will trigger this error.  Instead, do:
+.HP 8
+if (this_is_a_long_variable == another_variable)
+.br
+a = b + c;
+.RE
+.LP
+.TP 4
+.B
+empty if/for/while body not on its own line
+For visibility, empty bodies for if, for, and while statements should be
+on their own line.  For example:
+.RS 4
+.HP 4
+while (do_something(&x) == 0);
+.LP
+Will trigger this error.  Instead, do:
+.HP 8
+while (do_something(&x) == 0)
+.br
+;
+.RE
+
diff --git a/scripts/Makefile.am b/scripts/Makefile.am
index 39d94ee82..bc8fe99cf 100644
--- a/scripts/Makefile.am
+++ b/scripts/Makefile.am
@@ -1,6 +1,6 @@
 SUBDIRS = zpool-config zpios-test zpios-profile
 
-EXTRA_DIST = dkms.mkconf dkms.postinst kmodtool zfs2zol-patch.sed
+EXTRA_DIST = dkms.mkconf dkms.postinst kmodtool zfs2zol-patch.sed cstyle.pl
 
 pkgdatadir = $(datadir)/@PACKAGE@
 dist_pkgdata_SCRIPTS = \
diff --git a/scripts/cstyle.pl b/scripts/cstyle.pl
new file mode 100755
index 000000000..9f67b1d2e
--- /dev/null
+++ b/scripts/cstyle.pl
@@ -0,0 +1,950 @@
+#!/usr/bin/perl -w
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+#
+# Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+# @(#)cstyle 1.58 98/09/09 (from shannon)
+#ident	"%Z%%M%	%I%	%E% SMI"
+#
+# cstyle - check for some common stylistic errors.
+#
+#	cstyle is a sort of "lint" for C coding style.
+#	It attempts to check for the style used in the
+#	kernel, sometimes known as "Bill Joy Normal Form".
+#
+#	There's a lot this can't check for, like proper indentation
+#	of code blocks.  There's also a lot more this could check for.
+#
+#	A note to the non perl literate:
+#
+#		perl regular expressions are pretty much like egrep
+#		regular expressions, with the following special symbols
+#
+#		\s	any space character
+#		\S	any non-space character
+#		\w	any "word" character [a-zA-Z0-9_]
+#		\W	any non-word character
+#		\d	a digit [0-9]
+#		\D	a non-digit
+#		\b	word boundary (between \w and \W)
+#		\B	non-word boundary
+#
+
+require 5.0;
+use IO::File;
+use Getopt::Std;
+use strict;
+
+my $usage =
+"usage: cstyle [-chpvCP] [-o constructs] file ...
+	-c	check continuation indentation inside functions
+	-h	perform heuristic checks that are sometimes wrong
+	-p	perform some of the more picky checks
+	-v	verbose
+	-C	don't check anything in header block comments
+	-P	check for use of non-POSIX types
+	-o constructs
+		allow a comma-seperated list of optional constructs:
+		    doxygen	allow doxygen-style block comments (/** /*!)
+		    splint	allow splint-style lint comments (/*@ ... @*/)
+";
+
+my %opts;
+
+if (!getopts("cho:pvCP", \%opts)) {
+	print $usage;
+	exit 2;
+}
+
+my $check_continuation = $opts{'c'};
+my $heuristic = $opts{'h'};
+my $picky = $opts{'p'};
+my $verbose = $opts{'v'};
+my $ignore_hdr_comment = $opts{'C'};
+my $check_posix_types = $opts{'P'};
+
+my $doxygen_comments = 0;
+my $splint_comments = 0;
+
+if (defined($opts{'o'})) {
+	for my $x (split /,/, $opts{'o'}) {
+		if ($x eq "doxygen") {
+			$doxygen_comments = 1;
+		} elsif ($x eq "splint") {
+			$splint_comments = 1;
+		} else {
+			print "cstyle: unrecognized construct \"$x\"\n";
+			print $usage;
+			exit 2;
+		}
+	}
+}
+
+my ($filename, $line, $prev);		# shared globals
+
+my $fmt;
+my $hdr_comment_start;
+
+if ($verbose) {
+	$fmt = "%s: %d: %s\n%s\n";
+} else {
+	$fmt = "%s: %d: %s\n";
+}
+
+if ($doxygen_comments) {
+	# doxygen comments look like "/*!" or "/**"; allow them.
+	$hdr_comment_start = qr/^\s*\/\*[\!\*]?$/;
+} else {
+	$hdr_comment_start = qr/^\s*\/\*$/;
+}
+
+# Note, following must be in single quotes so that \s and \w work right.
+my $typename = '(int|char|short|long|unsigned|float|double' .
+    '|\w+_t|struct\s+\w+|union\s+\w+|FILE)';
+
+# mapping of old types to POSIX compatible types
+my %old2posix = (
+	'unchar' => 'uchar_t',
+	'ushort' => 'ushort_t',
+	'uint' => 'uint_t',
+	'ulong' => 'ulong_t',
+	'u_int' => 'uint_t',
+	'u_short' => 'ushort_t',
+	'u_long' => 'ulong_t',
+	'u_char' => 'uchar_t',
+	'quad' => 'quad_t'
+);
+
+my $lint_re = qr/\/\*(?:
+	ARGSUSED[0-9]*|NOTREACHED|LINTLIBRARY|VARARGS[0-9]*|
+	CONSTCOND|CONSTANTCOND|CONSTANTCONDITION|EMPTY|
+	FALLTHRU|FALLTHROUGH|LINTED.*?|PRINTFLIKE[0-9]*|
+	PROTOLIB[0-9]*|SCANFLIKE[0-9]*|CSTYLED.*?
+    )\*\//x;
+
+my $splint_re = qr/\/\*@.*?@\*\//x;
+
+my $warlock_re = qr/\/\*\s*(?:
+	VARIABLES\ PROTECTED\ BY|
+	MEMBERS\ PROTECTED\ BY|
+	ALL\ MEMBERS\ PROTECTED\ BY|
+	READ-ONLY\ VARIABLES:|
+	READ-ONLY\ MEMBERS:|
+	VARIABLES\ READABLE\ WITHOUT\ LOCK:|
+	MEMBERS\ READABLE\ WITHOUT\ LOCK:|
+	LOCKS\ COVERED\ BY|
+	LOCK\ UNNEEDED\ BECAUSE|
+	LOCK\ NEEDED:|
+	LOCK\ HELD\ ON\ ENTRY:|
+	READ\ LOCK\ HELD\ ON\ ENTRY:|
+	WRITE\ LOCK\ HELD\ ON\ ENTRY:|
+	LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
+	READ\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
+	WRITE\ LOCK\ ACQUIRED\ AS\ SIDE\ EFFECT:|
+	LOCK\ RELEASED\ AS\ SIDE\ EFFECT:|
+	LOCK\ UPGRADED\ AS\ SIDE\ EFFECT:|
+	LOCK\ DOWNGRADED\ AS\ SIDE\ EFFECT:|
+	FUNCTIONS\ CALLED\ THROUGH\ POINTER|
+	FUNCTIONS\ CALLED\ THROUGH\ MEMBER|
+	LOCK\ ORDER:
+    )/x;
+
+my $err_stat = 0;		# exit status
+
+if ($#ARGV >= 0) {
+	foreach my $arg (@ARGV) {
+		my $fh = new IO::File $arg, "r";
+		if (!defined($fh)) {
+			printf "%s: can not open\n", $arg;
+		} else {
+			&cstyle($arg, $fh);
+			close $fh;
+		}
+	}
+} else {
+	&cstyle("<stdin>", *STDIN);
+}
+exit $err_stat;
+
+my $no_errs = 0;		# set for CSTYLED-protected lines
+
+sub err($) {
+	my ($error) = @_;
+	unless ($no_errs) {
+		printf $fmt, $filename, $., $error, $line;
+		$err_stat = 1;
+	}
+}
+
+sub err_prefix($$) {
+	my ($prevline, $error) = @_;
+	my $out = $prevline."\n".$line;
+	unless ($no_errs) {
+		printf $fmt, $filename, $., $error, $out;
+		$err_stat = 1;
+	}
+}
+
+sub err_prev($) {
+	my ($error) = @_;
+	unless ($no_errs) {
+		printf $fmt, $filename, $. - 1, $error, $prev;
+		$err_stat = 1;
+	}
+}
+
+sub cstyle($$) {
+
+my ($fn, $filehandle) = @_;
+$filename = $fn;			# share it globally
+
+my $in_cpp = 0;
+my $next_in_cpp = 0;
+
+my $in_comment = 0;
+my $in_header_comment = 0;
+my $comment_done = 0;
+my $in_warlock_comment = 0;
+my $in_function = 0;
+my $in_function_header = 0;
+my $in_declaration = 0;
+my $note_level = 0;
+my $nextok = 0;
+my $nocheck = 0;
+
+my $in_string = 0;
+
+my ($okmsg, $comment_prefix);
+
+$line = '';
+$prev = '';
+reset_indent();
+
+line: while (<$filehandle>) {
+	s/\r?\n$//;	# strip return and newline
+
+	# save the original line, then remove all text from within
+	# double or single quotes, we do not want to check such text.
+
+	$line = $_;
+
+	#
+	# C allows strings to be continued with a backslash at the end of
+	# the line.  We translate that into a quoted string on the previous
+	# line followed by an initial quote on the next line.
+	#
+	# (we assume that no-one will use backslash-continuation with character
+	# constants)
+	#
+	$_ = '"' . $_		if ($in_string && !$nocheck && !$in_comment);
+
+	#
+	# normal strings and characters
+	#
+	s/'([^\\']|\\[^xX0]|\\0[0-9]*|\\[xX][0-9a-fA-F]*)'/''/g;
+	s/"([^\\"]|\\.)*"/\"\"/g;
+
+	#
+	# detect string continuation
+	#
+	if ($nocheck || $in_comment) {
+		$in_string = 0;
+	} else {
+		#
+		# Now that all full strings are replaced with "", we check
+		# for unfinished strings continuing onto the next line.
+		#
+		$in_string =
+		    (s/([^"](?:"")*)"([^\\"]|\\.)*\\$/$1""/ ||
+		    s/^("")*"([^\\"]|\\.)*\\$/""/);
+	}
+
+	#
+	# figure out if we are in a cpp directive
+	#
+	$in_cpp = $next_in_cpp || /^\s*#/;	# continued or started
+	$next_in_cpp = $in_cpp && /\\$/;	# only if continued
+
+	# strip off trailing backslashes, which appear in long macros
+	s/\s*\\$//;
+
+	# an /* END CSTYLED */ comment ends a no-check block.
+	if ($nocheck) {
+		if (/\/\* *END *CSTYLED *\*\//) {
+			$nocheck = 0;
+		} else {
+			reset_indent();
+			next line;
+		}
+	}
+
+	# a /*CSTYLED*/ comment indicates that the next line is ok.
+	if ($nextok) {
+		if ($okmsg) {
+			err($okmsg);
+		}
+		$nextok = 0;
+		$okmsg = 0;
+		if (/\/\* *CSTYLED.*\*\//) {
+			/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
+			$okmsg = $1;
+			$nextok = 1;
+		}
+		$no_errs = 1;
+	} elsif ($no_errs) {
+		$no_errs = 0;
+	}
+
+	# check length of line.
+	# first, a quick check to see if there is any chance of being too long.
+	if (($line =~ tr/\t/\t/) * 7 + length($line) > 80) {
+		# yes, there is a chance.
+		# replace tabs with spaces and check again.
+		my $eline = $line;
+		1 while $eline =~
+		    s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e;
+		if (length($eline) > 80) {
+			err("line > 80 characters");
+		}
+	}
+
+	# ignore NOTE(...) annotations (assumes NOTE is on lines by itself).
+	if ($note_level || /\b_?NOTE\s*\(/) { # if in NOTE or this is NOTE
+		s/[^()]//g;			  # eliminate all non-parens
+		$note_level += s/\(//g - length;  # update paren nest level
+		next;
+	}
+
+	# a /* BEGIN CSTYLED */ comment starts a no-check block.
+	if (/\/\* *BEGIN *CSTYLED *\*\//) {
+		$nocheck = 1;
+	}
+
+	# a /*CSTYLED*/ comment indicates that the next line is ok.
+	if (/\/\* *CSTYLED.*\*\//) {
+		/^.*\/\* *CSTYLED *(.*) *\*\/.*$/;
+		$okmsg = $1;
+		$nextok = 1;
+	}
+	if (/\/\/ *CSTYLED/) {
+		/^.*\/\/ *CSTYLED *(.*)$/;
+		$okmsg = $1;
+		$nextok = 1;
+	}
+
+	# universal checks; apply to everything
+	if (/\t +\t/) {
+		err("spaces between tabs");
+	}
+	if (/ \t+ /) {
+		err("tabs between spaces");
+	}
+	if (/\s$/) {
+		err("space or tab at end of line");
+	}
+	if (/[^ \t(]\/\*/ && !/\w\(\/\*.*\*\/\);/) {
+		err("comment preceded by non-blank");
+	}
+
+	# is this the beginning or ending of a function?
+	# (not if "struct foo\n{\n")
+	if (/^{$/ && $prev =~ /\)\s*(const\s*)?(\/\*.*\*\/\s*)?\\?$/) {
+		$in_function = 1;
+		$in_declaration = 1;
+		$in_function_header = 0;
+		$prev = $line;
+		next line;
+	}
+	if (/^}\s*(\/\*.*\*\/\s*)*$/) {
+		if ($prev =~ /^\s*return\s*;/) {
+			err_prev("unneeded return at end of function");
+		}
+		$in_function = 0;
+		reset_indent();		# we don't check between functions
+		$prev = $line;
+		next line;
+	}
+	if (/^\w*\($/) {
+		$in_function_header = 1;
+	}
+
+	if ($in_warlock_comment && /\*\//) {
+		$in_warlock_comment = 0;
+		$prev = $line;
+		next line;
+	}
+
+	# a blank line terminates the declarations within a function.
+	# XXX - but still a problem in sub-blocks.
+	if ($in_declaration && /^$/) {
+		$in_declaration = 0;
+	}
+
+	if ($comment_done) {
+		$in_comment = 0;
+		$in_header_comment = 0;
+		$comment_done = 0;
+	}
+	# does this looks like the start of a block comment?
+	if (/$hdr_comment_start/) {
+		if (!/^\t*\/\*/) {
+			err("block comment not indented by tabs");
+		}
+		$in_comment = 1;
+		/^(\s*)\//;
+		$comment_prefix = $1;
+		if ($comment_prefix eq "") {
+			$in_header_comment = 1;
+		}
+		$prev = $line;
+		next line;
+	}
+	# are we still in the block comment?
+	if ($in_comment) {
+		if (/^$comment_prefix \*\/$/) {
+			$comment_done = 1;
+		} elsif (/\*\//) {
+			$comment_done = 1;
+			err("improper block comment close")
+			    unless ($ignore_hdr_comment && $in_header_comment);
+		} elsif (!/^$comment_prefix \*[ \t]/ &&
+		    !/^$comment_prefix \*$/) {
+			err("improper block comment")
+			    unless ($ignore_hdr_comment && $in_header_comment);
+		}
+	}
+
+	if ($in_header_comment && $ignore_hdr_comment) {
+		$prev = $line;
+		next line;
+	}
+
+	# check for errors that might occur in comments and in code.
+
+	# allow spaces to be used to draw pictures in header comments.
+	if (/[^ ]     / && !/".*     .*"/ && !$in_header_comment) {
+		err("spaces instead of tabs");
+	}
+	if (/^ / && !/^ \*[ \t\/]/ && !/^ \*$/ &&
+	    (!/^    \w/ || $in_function != 0)) {
+		err("indent by spaces instead of tabs");
+	}
+	if (/^\t+ [^ \t\*]/ || /^\t+  \S/ || /^\t+   \S/) {
+		err("continuation line not indented by 4 spaces");
+	}
+	if (/$warlock_re/ && !/\*\//) {
+		$in_warlock_comment = 1;
+		$prev = $line;
+		next line;
+	}
+	if (/^\s*\/\*./ && !/^\s*\/\*.*\*\// && !/$hdr_comment_start/) {
+		err("improper first line of block comment");
+	}
+
+	if ($in_comment) {	# still in comment, don't do further checks
+		$prev = $line;
+		next line;
+	}
+
+	if ((/[^(]\/\*\S/ || /^\/\*\S/) &&
+	    !(/$lint_re/ || ($splint_comments && /$splint_re/))) {
+		err("missing blank after open comment");
+	}
+	if (/\S\*\/[^)]|\S\*\/$/ &&
+	    !(/$lint_re/ || ($splint_comments && /$splint_re/))) {
+		err("missing blank before close comment");
+	}
+	if (/\/\/\S/) {		# C++ comments
+		err("missing blank after start comment");
+	}
+	# check for unterminated single line comments, but allow them when
+	# they are used to comment out the argument list of a function
+	# declaration.
+	if (/\S.*\/\*/ && !/\S.*\/\*.*\*\// && !/\(\/\*/) {
+		err("unterminated single line comment");
+	}
+
+	if (/^(#else|#endif|#include)(.*)$/) {
+		$prev = $line;
+		if ($picky) {
+			my $directive = $1;
+			my $clause = $2;
+			# Enforce ANSI rules for #else and #endif: no noncomment
+			# identifiers are allowed after #endif or #else.  Allow
+			# C++ comments since they seem to be a fact of life.
+			if ((($1 eq "#endif") || ($1 eq "#else")) &&
+			    ($clause ne "") &&
+			    (!($clause =~ /^\s+\/\*.*\*\/$/)) &&
+			    (!($clause =~ /^\s+\/\/.*$/))) {
+				err("non-comment text following " .
+				    "$directive (or malformed $directive " .
+				    "directive)");
+			}
+		}
+		next line;
+	}
+
+	#
+	# delete any comments and check everything else.  Note that
+	# ".*?" is a non-greedy match, so that we don't get confused by
+	# multiple comments on the same line.
+	#
+	s/\/\*.*?\*\//
/g;
+	s/\/\/.*$/
/;		# C++ comments
+
+	# delete any trailing whitespace; we have already checked for that.
+	s/\s*$//;
+
+	# following checks do not apply to text in comments.
+
+	if (/[^<>\s][!<>=]=/ || /[^<>][!<>=]=[^\s,]/ ||
+	    (/[^->]>[^,=>\s]/ && !/[^->]>$/) ||
+	    (/[^<]<[^,=<\s]/ && !/[^<]<$/) ||
+	    /[^<\s]<[^<]/ || /[^->\s]>[^>]/) {
+		err("missing space around relational operator");
+	}
+	if (/\S>>=/ || /\S<<=/ || />>=\S/ || /<<=\S/ || /\S[-+*\/&|^%]=/ ||
+	    (/[^-+*\/&|^%!<>=\s]=[^=]/ && !/[^-+*\/&|^%!<>=\s]=$/) ||
+	    (/[^!<>=]=[^=\s]/ && !/[^!<>=]=$/)) {
+		# XXX - should only check this for C++ code
+		# XXX - there are probably other forms that should be allowed
+		if (!/\soperator=/) {
+			err("missing space around assignment operator");
+		}
+	}
+	if (/[,;]\S/ && !/\bfor \(;;\)/) {
+		err("comma or semicolon followed by non-blank");
+	}
+	# allow "for" statements to have empty "while" clauses
+	if (/\s[,;]/ && !/^[\t]+;$/ && !/^\s*for \([^;]*; ;[^;]*\)/) {
+		err("comma or semicolon preceded by blank");
+	}
+	if (/^\s*(&&|\|\|)/) {
+		err("improper boolean continuation");
+	}
+	if (/\S   *(&&|\|\|)/ || /(&&|\|\|)   *\S/) {
+		err("more than one space around boolean operator");
+	}
+	if (/\b(for|if|while|switch|sizeof|return|case)\(/) {
+		err("missing space between keyword and paren");
+	}
+	if (/(\b(for|if|while|switch|return)\b.*){2,}/ && !/^#define/) {
+		# multiple "case" and "sizeof" allowed
+		err("more than one keyword on line");
+	}
+	if (/\b(for|if|while|switch|sizeof|return|case)\s\s+\(/ &&
+	    !/^#if\s+\(/) {
+		err("extra space between keyword and paren");
+	}
+	# try to detect "func (x)" but not "if (x)" or
+	# "#define foo (x)" or "int (*func)();"
+	if (/\w\s\(/) {
+		my $s = $_;
+		# strip off all keywords on the line
+		s/\b(for|if|while|switch|return|case|sizeof)\s\(/XXX(/g;
+		s/#elif\s\(/XXX(/g;
+		s/^#define\s+\w+\s+\(/XXX(/;
+		# do not match things like "void (*f)();"
+		# or "typedef void (func_t)();"
+		s/\w\s\(+\*/XXX(*/g;
+		s/\b($typename|void)\s+\(+/XXX(/og;
+		if (/\w\s\(/) {
+			err("extra space between function name and left paren");
+		}
+		$_ = $s;
+	}
+	# try to detect "int foo(x)", but not "extern int foo(x);"
+	# XXX - this still trips over too many legitimate things,
+	# like "int foo(x,\n\ty);"
+#		if (/^(\w+(\s|\*)+)+\w+\(/ && !/\)[;,](\s|
)*$/ &&
+#		    !/^(extern|static)\b/) {
+#			err("return type of function not on separate line");
+#		}
+	# this is a close approximation
+	if (/^(\w+(\s|\*)+)+\w+\(.*\)(\s|
)*$/ &&
+	    !/^(extern|static)\b/) {
+		err("return type of function not on separate line");
+	}
+	if (/^#define /) {
+		err("#define followed by space instead of tab");
+	}
+	if (/^\s*return\W[^;]*;/ && !/^\s*return\s*\(.*\);/) {
+		err("unparenthesized return expression");
+	}
+	if (/\bsizeof\b/ && !/\bsizeof\s*\(.*\)/) {
+		err("unparenthesized sizeof expression");
+	}
+	if (/\(\s/) {
+		err("whitespace after left paren");
+	}
+	# allow "for" statements to have empty "continue" clauses
+	if (/\s\)/ && !/^\s*for \([^;]*;[^;]*; \)/) {
+		err("whitespace before right paren");
+	}
+	if (/^\s*\(void\)[^ ]/) {
+		err("missing space after (void) cast");
+	}
+	if (/\S{/ && !/{{/) {
+		err("missing space before left brace");
+	}
+	if ($in_function && /^\s+{/ &&
+	    ($prev =~ /\)\s*$/ || $prev =~ /\bstruct\s+\w+$/)) {
+		err("left brace starting a line");
+	}
+	if (/}(else|while)/) {
+		err("missing space after right brace");
+	}
+	if (/}\s\s+(else|while)/) {
+		err("extra space after right brace");
+	}
+	if (/\b_VOID\b|\bVOID\b|\bSTATIC\b/) {
+		err("obsolete use of VOID or STATIC");
+	}
+	if (/\b$typename\*/o) {
+		err("missing space between type name and *");
+	}
+	if (/^\s+#/) {
+		err("preprocessor statement not in column 1");
+	}
+	if (/^#\s/) {
+		err("blank after preprocessor #");
+	}
+	if (/!\s*(strcmp|strncmp|bcmp)\s*\(/) {
+		err("don't use boolean ! with comparison functions");
+	}
+
+	#
+	# We completely ignore, for purposes of indentation:
+	#  * lines outside of functions
+	#  * preprocessor lines
+	#
+	if ($check_continuation && $in_function && !$in_cpp) {
+		process_indent($_);
+	}
+	if ($picky) {
+		# try to detect spaces after casts, but allow (e.g.)
+		# "sizeof (int) + 1", "void (*funcptr)(int) = foo;", and
+		# "int foo(int) __NORETURN;"
+		if ((/^\($typename( \*+)?\)\s/o ||
+		    /\W\($typename( \*+)?\)\s/o) &&
+		    !/sizeof\s*\($typename( \*)?\)\s/o &&
+		    !/\($typename( \*+)?\)\s+=[^=]/o) {
+			err("space after cast");
+		}
+		if (/\b$typename\s*\*\s/o &&
+		    !/\b$typename\s*\*\s+const\b/o) {
+			err("unary * followed by space");
+		}
+	}
+	if ($check_posix_types) {
+		# try to detect old non-POSIX types.
+		# POSIX requires all non-standard typedefs to end in _t,
+		# but historically these have been used.
+		if (/\b(unchar|ushort|uint|ulong|u_int|u_short|u_long|u_char|quad)\b/) {
+			err("non-POSIX typedef $1 used: use $old2posix{$1} instead");
+		}
+	}
+	if ($heuristic) {
+		# cannot check this everywhere due to "struct {\n...\n} foo;"
+		if ($in_function && !$in_declaration &&
+		    /}./ && !/}\s+=/ && !/{.*}[;,]$/ && !/}(\s|
)*$/ &&
+		    !/} (else|while)/ && !/}}/) {
+			err("possible bad text following right brace");
+		}
+		# cannot check this because sub-blocks in
+		# the middle of code are ok
+		if ($in_function && /^\s+{/) {
+			err("possible left brace starting a line");
+		}
+	}
+	if (/^\s*else\W/) {
+		if ($prev =~ /^\s*}$/) {
+			err_prefix($prev,
+			    "else and right brace should be on same line");
+		}
+	}
+	$prev = $line;
+}
+
+if ($prev eq "") {
+	err("last line in file is blank");
+}
+
+}
+
+#
+# Continuation-line checking
+#
+# The rest of this file contains the code for the continuation checking
+# engine.  It's a pretty simple state machine which tracks the expression
+# depth (unmatched '('s and '['s).
+#
+# Keep in mind that the argument to process_indent() has already been heavily
+# processed; all comments have been replaced by control-A, and the contents of
+# strings and character constants have been elided.
+#
+
+my $cont_in;		# currently inside of a continuation
+my $cont_off;		# skipping an initializer or definition
+my $cont_noerr;		# suppress cascading errors
+my $cont_start;		# the line being continued
+my $cont_base;		# the base indentation
+my $cont_first;		# this is the first line of a statement
+my $cont_multiseg;	# this continuation has multiple segments
+
+my $cont_special;	# this is a C statement (if, for, etc.)
+my $cont_macro;		# this is a macro
+my $cont_case;		# this is a multi-line case
+
+my @cont_paren;		# the stack of unmatched ( and [s we've seen
+
+sub
+reset_indent()
+{
+	$cont_in = 0;
+	$cont_off = 0;
+}
+
+sub
+delabel($)
+{
+	#
+	# replace labels with tabs.  Note that there may be multiple
+	# labels on a line.
+	#
+	local $_ = $_[0];
+
+	while (/^(\t*)( *(?:(?:\w+\s*)|(?:case\b[^:]*)): *)(.*)$/) {
+		my ($pre_tabs, $label, $rest) = ($1, $2, $3);
+		$_ = $pre_tabs;
+		while ($label =~ s/^([^\t]*)(\t+)//) {
+			$_ .= "\t" x (length($2) + length($1) / 8);
+		}
+		$_ .= ("\t" x (length($label) / 8)).$rest;
+	}
+
+	return ($_);
+}
+
+sub
+process_indent($)
+{
+	require strict;
+	local $_ = $_[0];			# preserve the global $_
+
+	s/
//g;	# No comments
+	s/\s+$//;	# Strip trailing whitespace
+
+	return			if (/^$/);	# skip empty lines
+
+	# regexps used below; keywords taking (), macros, and continued cases
+	my $special = '(?:(?:\}\s*)?else\s+)?(?:if|for|while|switch)\b';
+	my $macro = '[A-Z_][A-Z_0-9]*\(';
+	my $case = 'case\b[^:]*$';
+
+	# skip over enumerations, array definitions, initializers, etc.
+	if ($cont_off <= 0 && !/^\s*$special/ &&
+	    (/(?:(?:\b(?:enum|struct|union)\s*[^\{]*)|(?:\s+=\s*)){/ ||
+	    (/^\s*{/ && $prev =~ /=\s*(?:\/\*.*\*\/\s*)*$/))) {
+		$cont_in = 0;
+		$cont_off = tr/{/{/ - tr/}/}/;
+		return;
+	}
+	if ($cont_off) {
+		$cont_off += tr/{/{/ - tr/}/}/;
+		return;
+	}
+
+	if (!$cont_in) {
+		$cont_start = $line;
+
+		if (/^\t* /) {
+			err("non-continuation indented 4 spaces");
+			$cont_noerr = 1;		# stop reporting
+		}
+		$_ = delabel($_);	# replace labels with tabs
+
+		# check if the statement is complete
+		return		if (/^\s*\}?$/);
+		return		if (/^\s*\}?\s*else\s*\{?$/);
+		return		if (/^\s*do\s*\{?$/);
+		return		if (/{$/);
+		return		if (/}[,;]?$/);
+
+		# Allow macros on their own lines
+		return		if (/^\s*[A-Z_][A-Z_0-9]*$/);
+
+		# cases we don't deal with, generally non-kosher
+		if (/{/) {
+			err("stuff after {");
+			return;
+		}
+
+		# Get the base line, and set up the state machine
+		/^(\t*)/;
+		$cont_base = $1;
+		$cont_in = 1;
+		@cont_paren = ();
+		$cont_first = 1;
+		$cont_multiseg = 0;
+
+		# certain things need special processing
+		$cont_special = /^\s*$special/? 1 : 0;
+		$cont_macro = /^\s*$macro/? 1 : 0;
+		$cont_case = /^\s*$case/? 1 : 0;
+	} else {
+		$cont_first = 0;
+
+		# Strings may be pulled back to an earlier (half-)tabstop
+		unless ($cont_noerr || /^$cont_base    / ||
+		    (/^\t*(?:    )?(?:gettext\()?\"/ && !/^$cont_base\t/)) {
+			err_prefix($cont_start,
+			    "continuation should be indented 4 spaces");
+		}
+	}
+
+	my $rest = $_;			# keeps the remainder of the line
+
+	#
+	# The split matches 0 characters, so that each 'special' character
+	# is processed separately.  Parens and brackets are pushed and
+	# popped off the @cont_paren stack.  For normal processing, we wait
+	# until a ; or { terminates the statement.  "special" processing
+	# (if/for/while/switch) is allowed to stop when the stack empties,
+	# as is macro processing.  Case statements are terminated with a :
+	# and an empty paren stack.
+	#
+	foreach $_ (split /[^\(\)\[\]\{\}\;\:]*/) {
+		next		if (length($_) == 0);
+
+		# rest contains the remainder of the line
+		my $rxp = "[^\Q$_\E]*\Q$_\E";
+		$rest =~ s/^$rxp//;
+
+		if (/\(/ || /\[/) {
+			push @cont_paren, $_;
+		} elsif (/\)/ || /\]/) {
+			my $cur = $_;
+			tr/\)\]/\(\[/;
+
+			my $old = (pop @cont_paren);
+			if (!defined($old)) {
+				err("unexpected '$cur'");
+				$cont_in = 0;
+				last;
+			} elsif ($old ne $_) {
+				err("'$cur' mismatched with '$old'");
+				$cont_in = 0;
+				last;
+			}
+
+			#
+			# If the stack is now empty, do special processing
+			# for if/for/while/switch and macro statements.
+			#
+			next		if (@cont_paren != 0);
+			if ($cont_special) {
+				if ($rest =~ /^\s*{?$/) {
+					$cont_in = 0;
+					last;
+				}
+				if ($rest =~ /^\s*;$/) {
+					err("empty if/for/while body ".
+					    "not on its own line");
+					$cont_in = 0;
+					last;
+				}
+				if (!$cont_first && $cont_multiseg == 1) {
+					err_prefix($cont_start,
+					    "multiple statements continued ".
+					    "over multiple lines");
+					$cont_multiseg = 2;
+				} elsif ($cont_multiseg == 0) {
+					$cont_multiseg = 1;
+				}
+				# We've finished this section, start
+				# processing the next.
+				goto section_ended;
+			}
+			if ($cont_macro) {
+				if ($rest =~ /^$/) {
+					$cont_in = 0;
+					last;
+				}
+			}
+		} elsif (/\;/) {
+			if ($cont_case) {
+				err("unexpected ;");
+			} elsif (!$cont_special) {
+				err("unexpected ;")	if (@cont_paren != 0);
+				if (!$cont_first && $cont_multiseg == 1) {
+					err_prefix($cont_start,
+					    "multiple statements continued ".
+					    "over multiple lines");
+					$cont_multiseg = 2;
+				} elsif ($cont_multiseg == 0) {
+					$cont_multiseg = 1;
+				}
+				if ($rest =~ /^$/) {
+					$cont_in = 0;
+					last;
+				}
+				if ($rest =~ /^\s*special/) {
+					err("if/for/while/switch not started ".
+					    "on its own line");
+				}
+				goto section_ended;
+			}
+		} elsif (/\{/) {
+			err("{ while in parens/brackets") if (@cont_paren != 0);
+			err("stuff after {")		if ($rest =~ /[^\s}]/);
+			$cont_in = 0;
+			last;
+		} elsif (/\}/) {
+			err("} while in parens/brackets") if (@cont_paren != 0);
+			if (!$cont_special && $rest !~ /^\s*(while|else)\b/) {
+				if ($rest =~ /^$/) {
+					err("unexpected }");
+				} else {
+					err("stuff after }");
+				}
+				$cont_in = 0;
+				last;
+			}
+		} elsif (/\:/ && $cont_case && @cont_paren == 0) {
+			err("stuff after multi-line case") if ($rest !~ /$^/);
+			$cont_in = 0;
+			last;
+		}
+		next;
+section_ended:
+		# End of a statement or if/while/for loop.  Reset
+		# cont_special and cont_macro based on the rest of the
+		# line.
+		$cont_special = ($rest =~ /^\s*$special/)? 1 : 0;
+		$cont_macro = ($rest =~ /^\s*$macro/)? 1 : 0;
+		$cont_case = 0;
+		next;
+	}
+	$cont_noerr = 0			if (!$cont_in);
+}