Reimported pkglint-4.518 from pkgtools/pkglint as pkglint4

The Perl version of pkglint (pkglint<5.0) runs on all platforms that
are supported by pkgsrc. Not so the Go version (pkglint>=5.0).

To support development of packages on all platforms, this version is
provided, and it will be supported equally. Its output differs a bit
from pkglint>=5.0, but the basic checks are the same.

38 files changed, 11410 insertions, 1 deletions

diff --git a/pkgtools/Makefile b/pkgtools/Makefile
index cc2b57f7840..67dfc51bbaf 100644
--- a/pkgtools/Makefile
+++ b/pkgtools/Makefile
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.111 2015/11/22 21:58:36 agc Exp $
+# $NetBSD: Makefile,v 1.112 2015/11/25 16:42:21 rillig Exp $
 #
 
 COMMENT=	Tools for use in the packages collection
@@ -56,6 +56,7 @@ SUBDIR+=	pkgdiff
 SUBDIR+=	pkgfind
 SUBDIR+=	pkgin
 SUBDIR+=	pkglint
+SUBDIR+=	pkglint4
 SUBDIR+=	pkgse
 SUBDIR+=	pkgsrc-todo
 SUBDIR+=	pkgsurvey
diff --git a/pkgtools/pkglint4/DESCR b/pkgtools/pkglint4/DESCR
new file mode 100644
index 00000000000..bff78e0924e
--- /dev/null
+++ b/pkgtools/pkglint4/DESCR
@@ -0,0 +1,7 @@
+pkglint is for pkgsrc packages what lint(1) is for C files. It checks
+for various things that the used languages cannot detect, for example
+application-specific restrictions on certain variables.
+
+Before importing a new package or making changes to an existing package,
+pkglint should be run in the package's directory to check for common
+errors.
diff --git a/pkgtools/pkglint4/Makefile b/pkgtools/pkglint4/Makefile
new file mode 100644
index 00000000000..7adf676a4e4
--- /dev/null
+++ b/pkgtools/pkglint4/Makefile
@@ -0,0 +1,78 @@
+# $NetBSD: Makefile,v 1.1 2015/11/25 16:42:21 rillig Exp $
+
+PKGNAME=	pkglint4-4.158
+CATEGORIES=	pkgtools
+
+OWNER=		wiz@NetBSD.org
+HOMEPAGE=	http://www.NetBSD.org/docs/pkgsrc/
+COMMENT=	Verifier for NetBSD packages (old version, for all platforms)
+LICENSE=	2-clause-bsd
+
+DEPENDS+=	p5-Digest-SHA1-[0-9]*:../../security/p5-Digest-SHA1
+DEPENDS+=	p5-enum>=1.016:../../devel/p5-enum
+DEPENDS+=	p5-pkgsrc-Dewey>=1.0:../../pkgtools/p5-pkgsrc-Dewey
+CONFLICTS+=	pkglint>=5.0
+
+#BUILD_DEPENDS+=	p5-Test-Deep-[0-9]*:../../devel/p5-Test-Deep
+#BUILD_DEPENDS+=	p5-Test-Trap-[0-9]*:../../devel/p5-Test-Trap
+
+WRKSRC=		${WRKDIR}
+NO_CHECKSUM=	yes
+USE_LANGUAGES=	# none
+USE_TOOLS+=	perl:run
+AUTO_MKDIRS=	yes
+PREV_PKGPATH=	pkgtools/pkglint
+
+.include "../../mk/bsd.prefs.mk"
+
+SUBST_CLASSES+=		pkglint
+SUBST_STAGE.pkglint=	post-configure
+SUBST_FILES.pkglint+=	build.pl pkglint.pl pkglint.t plist-clash.pl
+.if defined(BATCH)
+SUBST_SED.pkglint+=	-e s\|@PKGSRCDIR@\|/usr/pkgsrc\|g
+.else
+SUBST_SED.pkglint+=	-e s\|@PKGSRCDIR@\|${PKGSRCDIR}\|g
+.endif
+SUBST_SED.pkglint+=	-e s\|@PREFIX@\|${PREFIX}\|g
+SUBST_SED.pkglint+=	-e s\|@DISTVER@\|${PKGNAME:S/pkglint-//}\|g
+SUBST_SED.pkglint+=	-e s\|@MAKE@\|${MAKE:Q}\|g
+SUBST_SED.pkglint+=	-e s\|@PERL@\|${PERL5:Q}\|g
+SUBST_SED.pkglint+=	-e s\|@DATADIR@\|${FILESDIR}\|g
+
+SUBST_CLASSES+=		mappaths
+SUBST_STAGE.mappaths=	pre-install
+SUBST_FILES.mappaths+=	pkglint.pl
+SUBST_SED.mappaths+=	-e s\|${FILESDIR}\|${PREFIX}/share/pkglint\|g
+
+do-extract:
+	cd ${FILESDIR} && ${CP} build.pl pkglint.0 pkglint.1 pkglint.pl pkglint.t plist-clash.pl ${WRKSRC}
+	mkdir ${WRKSRC}/PkgLint
+	cd ${FILESDIR} && ${CP} PkgLint/*.pm ${WRKSRC}/PkgLint
+
+do-build:
+	cd ${WRKSRC} && ${PERL5} build.pl < pkglint.pl > pkglint.pl.inlined \
+		&& mv pkglint.pl.inlined pkglint.pl
+
+do-test:
+	cd ${WRKSRC} && prove pkglint.t
+
+do-install:
+	${INSTALL_SCRIPT} ${WRKSRC}/pkglint.pl ${DESTDIR}${PREFIX}/bin/pkglint
+	${INSTALL_SCRIPT} ${WRKSRC}/plist-clash.pl ${DESTDIR}${PREFIX}/bin/plist-clash
+.if !empty(MANINSTALL:Mcatinstall)
+.  if defined(CATMAN_SECTION_SUFFIX) && !empty(CATMAN_SECTION_SUFFIX:M[Yy][Ee][Ss])
+	${INSTALL_MAN} ${WRKSRC}/pkglint.0 ${DESTDIR}${PREFIX}/${PKGMANDIR}/cat1/pkglint.1
+.  else
+	${INSTALL_MAN} ${WRKSRC}/pkglint.0 ${DESTDIR}${PREFIX}/${PKGMANDIR}/cat1
+.  endif
+.endif
+.if !empty(MANINSTALL:Mmaninstall)
+	${INSTALL_MAN} ${WRKSRC}/pkglint.1 ${DESTDIR}${PREFIX}/${PKGMANDIR}/man1
+.endif
+	${INSTALL_DATA} ${FILESDIR}/makevars.map ${DESTDIR}${PREFIX}/share/pkglint/
+	${INSTALL_DATA} ${FILESDIR}/deprecated.map ${DESTDIR}${PREFIX}/share/pkglint/
+
+selftest: .PHONY
+	${PREFIX}/bin/pkglint
+
+.include "../../mk/bsd.pkg.mk"
diff --git a/pkgtools/pkglint4/PLIST b/pkgtools/pkglint4/PLIST
new file mode 100644
index 00000000000..cf8a9737107
--- /dev/null
+++ b/pkgtools/pkglint4/PLIST
@@ -0,0 +1,7 @@
+@comment $NetBSD: PLIST,v 1.1 2015/11/25 16:42:21 rillig Exp $
+bin/pkglint
+bin/plist-clash
+man/cat1/pkglint.0
+man/man1/pkglint.1
+share/pkglint/deprecated.map
+share/pkglint/makevars.map
diff --git a/pkgtools/pkglint4/README b/pkgtools/pkglint4/README
new file mode 100644
index 00000000000..6c5eb9d7479
--- /dev/null
+++ b/pkgtools/pkglint4/README
@@ -0,0 +1,27 @@
+$NetBSD: README,v 1.1 2015/11/25 16:42:21 rillig Exp $
+
+== Current problems ==
+
+There are finally some automated tests that document a few intended
+and actual behaviors. There is still plenty of poorly expressed
+code not yet under test and therefore not yet safe to refactor.
+
+The current pkglint architecture will not scale much further. What is
+needed next are parsers for nested, non-context-free languages (make(1),
+sh(1), sed(1)). The parsers should be able to recognize partial
+structures, as well as structures containing foreign parts. This is
+because most of pkgsrc is heavily based on preprocessors:
+
+- The .if and .for directives in Makefiles are preprocessed by make(1)
+  before building dependencies and shell commands out of the remaining
+  text.
+
+- make(1) assembles shell commands from literal text and variables like
+  ${PKGNAME}.
+
+- Shell commands often use dynamic evaluation of variables.
+
+All this makes enhancing pkglint non-trivial. If you know of any
+academic papers that might be of help in this case, please tell me.
+
+The pkglint source code is much too big for a single file.
diff --git a/pkgtools/pkglint4/TODO b/pkgtools/pkglint4/TODO
new file mode 100644
index 00000000000..52b0d5d2ffa
--- /dev/null
+++ b/pkgtools/pkglint4/TODO
@@ -0,0 +1,37 @@
+$NetBSD: TODO,v 1.1 2015/11/25 16:42:21 rillig Exp $
+
+Please add your own entries at the bottom of this file. If possible,
+include the name of an example package where a warning should occur.
+
+* When you understand some behavior of the code, document it by
+  adding automated tests to pkglint.t!
+* warn about the use of ${WRKDIR:=...}, as this construct should only
+  be used with lists.
+* Add checks for binary packages. See Debian/lintian for ideas.
+* Of the user-defined variables, some may be used at load-time and some
+  don't. Find out how pkglint can distinguish them.
+* Make sure that no variable is modified at load-time after it has been
+  used once. This should at least flag BUILD_DEFS in bsd.pkg.mk.
+* Invent an annotation scheme for files that intentionally define
+  variables for use in other files.
+* ${MACHINE_ARCH}-${LOWER_OPSYS}elf in PLISTs etc. is a NetBSD config.guess
+  problem ==> use of ${APPEND_ELF}
+* Packages including lang/python/extension.mk must follow the Python version
+  scheme. Enforcing PYPKGPREFIX for those is most likely a good idea.
+* Check for parallel files/dirs whose names differ only in case.
+* Check for license files that are completely unused.
+* If a dependency depends on an option (in options.mk), it should also
+  depend on the same option in the buildlink3.mk file.
+* Complain about ${PKGSRC_COMPILER} == "sunpro", which should be
+  !empty(PKGSRC_COMPILER:Msunpro).
+* If USE_TOOLS has autoconf213, and the package does stuff like
+  cd ${WRKSRC} && autoconf, then an incorrect warning is issued.
+* LOCALBASE should not be used in normal Makefiles
+* don't complain about "procedure calls", like for pkg-build-options in
+  the various buildlink3.mk files.
+* if package A conflicts with B, then B should also conflict with A.
+* When pkglint runs on a case-insensitive filesystem, it should still
+  point out problems that only occur on case-sensitive filesystems. For
+  example, devel/p5-Net-LDAP and devel/p5-Net-ldap should be considered
+  different paths.
+* Warn about using REPLACE_PYTHON without including application.mk.
diff --git a/pkgtools/pkglint4/files/PkgLint/CVS_Entry.pm b/pkgtools/pkglint4/files/PkgLint/CVS_Entry.pm
new file mode 100644
index 00000000000..3fe7559fd65
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/CVS_Entry.pm
@@ -0,0 +1,21 @@
+# $NetBSD: CVS_Entry.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# One line from a CVS/Entries file.
+#
+package PkgLint::CVS_Entry;
+
+use strict;
+use warnings;
+
+use enum qw(FNAME REVISION MTIME TAG);
+
+sub new($$$$$) {
+	my ($class, $fname, $revision, $date, $tag) = @_;
+	my $self = [ $fname, $revision, $date, $tag ];
+	bless($self, $class);
+	return $self;
+}
+sub fname($)			{ return shift()->[FNAME]; }
+sub revision($)			{ return shift()->[REVISION]; }
+sub mtime($)			{ return shift()->[MTIME]; }
+sub tag($)			{ return shift()->[TAG]; }
diff --git a/pkgtools/pkglint4/files/PkgLint/Change.pm b/pkgtools/pkglint4/files/PkgLint/Change.pm
new file mode 100644
index 00000000000..89368c465fe
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/Change.pm
@@ -0,0 +1,21 @@
+# $NetBSD: Change.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# A change entry from doc/CHANGES-*
+#
+package PkgLint::Change;
+
+use strict;
+use warnings;
+
+sub new($$$$$$) {
+	my ($class, $line, $action, $pkgpath, $version, $author, $date) = @_;
+	my $self = [ $line, $action, $pkgpath, $version, $author, $date ];
+	bless($self, $class);
+	return $self;
+}
+sub line($)			{ return shift()->[0]; }
+sub action($)			{ return shift()->[1]; }
+sub pkgpath($)			{ return shift()->[2]; }
+sub version($)			{ return shift()->[3]; }
+sub author($)			{ return shift()->[4]; }
+sub date($)			{ return shift()->[5]; }
diff --git a/pkgtools/pkglint4/files/PkgLint/FileUtil.pm b/pkgtools/pkglint4/files/PkgLint/FileUtil.pm
new file mode 100644
index 00000000000..f29c2bdccc7
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/FileUtil.pm
@@ -0,0 +1,166 @@
+# $NetBSD: FileUtil.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# Subroutines for loading and saving line-oriented files.
+# The load_file() subroutine loads a file completely into memory,
+# optionally handling continuation line folding. The load_lines() subrou-
+# tine is an abbreviation for the common case of loading files without
+# continuation lines. The save_autofix_changes() subroutine examines an
+# array of lines if some of them have changed. It then saves the modified
+# files.
+#
+package PkgLint::FileUtil;
+
+use strict;
+use warnings;
+
+BEGIN {
+	use Exporter;
+	use vars qw(@ISA @EXPORT_OK);
+	@ISA = qw(Exporter);
+	@EXPORT_OK = qw(
+		load_file load_lines
+		save_autofix_changes
+	);
+
+	import PkgLint::Util qw(
+		false true
+	);
+	import PkgLint::Logging qw(
+		NO_LINE_NUMBER
+		log_error log_note
+	);
+}
+
+sub load_physical_lines($) {
+	my ($fname) = @_;
+	my ($physlines, $line, $lineno);
+
+	$physlines = [];
+	open(my $f, "<", $fname) or return;
+	$lineno = 0;
+	while (defined($line = <$f>)) {
+		$lineno++;
+		push(@{$physlines}, [$lineno, $line]);
+	}
+	close($f) or return;
+	return $physlines;
+}
+
+sub get_logical_line($$$) {
+	my ($fname, $lines, $ref_lineno) = @_;
+	my ($value, $lineno, $first, $firstlineno, $lastlineno, $physlines);
+
+	$value = "";
+	$first = true;
+	$lineno = ${$ref_lineno};
+	$firstlineno = $lines->[$lineno]->[0];
+	$physlines = [];
+
+	for (; $lineno <= $#{$lines}; $lineno++) {
+		if ($lines->[$lineno]->[1] =~ m"^([ \t]*)(.*?)([ \t]*)(\\?)\n?$") {
+			my ($indent, $text, $outdent, $cont) = ($1, $2, $3, $4);
+
+			if ($first) {
+				$value .= $indent;
+				$first = false;
+			}
+
+			$value .= $text;
+			push(@{$physlines}, $lines->[$lineno]);
+
+			if ($cont eq "\\") {
+				$value .= " ";
+			} else {
+				$value .= $outdent;
+				last;
+			}
+		}
+	}
+
+	if ($lineno > $#{$lines}) {
+		# The last line in the file is a continuation line
+		$lineno--;
+	}
+	$lastlineno = $lines->[$lineno]->[0];
+	${$ref_lineno} = $lineno + 1;
+
+	return PkgLint::Line->new($fname,
+	    $firstlineno == $lastlineno
+		? $firstlineno
+		: "$firstlineno--$lastlineno",
+	    $value,
+	    $physlines);
+}
+
+sub load_lines($$) {
+	my ($fname, $fold_backslash_lines) = @_;
+	my ($physlines, $seen_newline, $loglines);
+
+	$physlines = load_physical_lines($fname);
+	if (!$physlines) {
+		return false;
+	}
+
+	$seen_newline = true;
+	$loglines = [];
+	if ($fold_backslash_lines) {
+		for (my $lineno = 0; $lineno <= $#{$physlines}; ) {
+			push(@{$loglines}, get_logical_line($fname, $physlines, \$lineno));
+		}
+	} else {
+		foreach my $physline (@{$physlines}) {
+			my $text = $physline->[1];
+
+			$text =~ s/\n$//;
+			push(@{$loglines}, PkgLint::Line->new($fname, $physline->[0], $text, [$physline]));
+		}
+	}
+
+	if (0 <= $#{$physlines} && $physlines->[-1]->[1] !~ m"\n$") {
+		log_error($fname, $physlines->[-1]->[0], "File must end with a newline.");
+	}
+
+	return $loglines;
+}
+
+sub load_file($) {
+	my ($fname) = @_;
+
+	return load_lines($fname, false);
+}
+
+sub save_autofix_changes($) {
+	my ($lines) = @_;
+
+	my (%changed, %physlines);
+
+	foreach my $line (@{$lines}) {
+		if ($line->is_changed) {
+			$changed{$line->fname}++;
+		}
+		push(@{$physlines{$line->fname}}, @{$line->physlines});
+	}
+
+	foreach my $fname (sort(keys(%changed))) {
+		my $new = "${fname}.pkglint.tmp";
+		my $f;
+
+		if (!open($f, ">", $new)) {
+			log_error($new, NO_LINE_NUMBER, "$!");
+			next;
+		}
+		foreach my $physline (@{$physlines{$fname}}) {
+			print $f ($physline->[1]);
+		}
+		if (!close($f)) {
+			log_error($new, NO_LINE_NUMBER, "$!");
+			next;
+		}
+
+		if (!rename($new, $fname)) {
+			log_error($fname, NO_LINE_NUMBER, "$!");
+			next;
+		}
+		log_note($fname, NO_LINE_NUMBER, "Has been autofixed. Please re-run pkglint.");
+	}
+}
diff --git a/pkgtools/pkglint4/files/PkgLint/Line.pm b/pkgtools/pkglint4/files/PkgLint/Line.pm
new file mode 100644
index 00000000000..cc93af4f59e
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/Line.pm
@@ -0,0 +1,217 @@
+# $NetBSD: Line.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# When files are read in by pkglint, they are interpreted in terms of
+# lines. For Makefiles, line continuations are handled properly, allowing
+# multiple physical lines to end in a single logical line. For other files
+# there is a 1:1 translation.
+#
+# A difference between the physical and the logical lines is that the
+# physical lines include the line end sequence, whereas the logical lines
+# do not.
+#
+# A logical line is a class having the read-only fields C<file>,
+# C<lines>, C<text>, C<physlines> and C<is_changed>, as well as some
+# methods for printing diagnostics easily.
+#
+# Some other methods allow modification of the physical lines, but leave
+# the logical line (the C<text>) untouched. These methods are used in the
+# --autofix mode.
+#
+# A line can have some "extra" fields that allow the results of parsing to
+# be saved under a name.
+#
+package PkgLint::Line;
+
+use strict;
+use warnings;
+
+BEGIN {
+	import PkgLint::Util qw(
+		false true
+		assert
+	);
+}
+
+use enum qw(FNAME LINES TEXT PHYSLINES CHANGED BEFORE AFTER EXTRA);
+
+sub new($$$$) {
+	my ($class, $fname, $lines, $text, $physlines) = @_;
+	my ($self) = ([$fname, $lines, $text, $physlines, false, [], [], {}]);
+	bless($self, $class);
+	return $self;
+}
+
+sub fname($)		{ return shift()->[FNAME]; }
+sub lines($)		{ return shift()->[LINES]; }
+sub text($)		{ return shift()->[TEXT]; }
+# Note: physlines is _not_ a simple getter method.
+sub is_changed($)	{ return shift()->[CHANGED]; }
+
+# querying, getting and setting the extra values.
+sub has($$) {
+	my ($self, $name) = @_;
+	return exists($self->[EXTRA]->{$name});
+}
+sub get($$) {
+	my ($self, $name) = @_;
+	assert(false, "Field ${name} does not exist.")
+		unless exists($self->[EXTRA]->{$name});
+	return $self->[EXTRA]->{$name};
+}
+sub set($$$) {
+	my ($self, $name, $value) = @_;
+	assert(false, "Field ${name} already exists.")
+		if exists($self->[EXTRA]->{$name});
+
+	# Make sure that the line does not become a cyclic data structure.
+	my $type = ref($value);
+	if ($type eq "") {
+		# ok
+	} elsif ($type eq "ARRAY") {
+		foreach my $element (@{$value}) {
+			my $element_type = ref($element);
+			assert(false, "Invalid array data type: name=${name}, type=${element_type}.")
+				unless $element_type eq "" || $element_type eq "PkgLint::SimpleMatch";
+		}
+	} else {
+		assert(false, "Invalid data: name=${name}, value=${value}.");
+	}
+
+	$self->[EXTRA]->{$name} = $value;
+}
+
+sub physlines($) {
+	my ($self) = @_;
+	return [@{$self->[BEFORE]}, @{$self->[PHYSLINES]}, @{$self->[AFTER]}];
+}
+
+# Only for PkgLint::String support
+sub substring($$$$) {
+	my ($self, $line, $start, $end) = @_;
+
+	return substr($self->[PHYSLINES]->[$line]->[1], $start, $end);
+}
+
+sub show_source($$) {
+	my ($self, $out) = @_;
+
+	if (PkgLint::Logging::get_show_source_flag()) {
+		print $out ("\n");
+		foreach my $line (@{$self->physlines}) {
+			print $out ("> " . $line->[1]);
+		}
+	}
+}
+
+sub log_fatal($$) {
+	my ($self, $text) = @_;
+
+	$self->show_source(*STDERR);
+	PkgLint::Logging::log_fatal($self->fname, $self->[LINES], $text);
+}
+sub log_error($$) {
+	my ($self, $text) = @_;
+
+	$self->show_source(*STDOUT);
+	PkgLint::Logging::log_error($self->fname, $self->[LINES], $text);
+}
+sub log_warning($$) {
+	my ($self, $text) = @_;
+
+	$self->show_source(*STDOUT);
+	PkgLint::Logging::log_warning($self->fname, $self->[LINES], $text);
+}
+sub log_note($$) {
+	my ($self, $text) = @_;
+
+	$self->show_source(*STDOUT);
+	PkgLint::Logging::log_note($self->fname, $self->[LINES], $text);
+}
+sub log_debug($$) {
+	my ($self, $text) = @_;
+
+	$self->show_source(*STDOUT);
+	PkgLint::Logging::log_debug($self->fname, $self->[LINES], $text);
+}
+sub explain_error($@) {
+	my ($self, @texts) = @_;
+
+	PkgLint::Logging::explain_error($self->fname, $self->[LINES], @texts);
+}
+sub explain_warning($@) {
+	my ($self, @texts) = @_;
+
+	PkgLint::Logging::explain_warning($self->fname, $self->[LINES], @texts);
+}
+sub explain_note($@) {
+	my ($self, @texts) = @_;
+
+	PkgLint::Logging::explain_note($self->fname, $self->[LINES], @texts);
+}
+sub explain_info($@) {
+	my ($self, @texts) = @_;
+
+	PkgLint::Logging::explain_info($self->fname, $self->[LINES], @texts);
+}
+
+sub to_string($) {
+	my ($self) = @_;
+
+	return $self->fname . ":" . $self->[LINES] . ": " . $self->[TEXT];
+}
+
+sub prepend_before($$) {
+	my ($self, $text) = @_;
+
+	unshift(@{$self->[BEFORE]}, [0, "$text\n"]);
+	$self->[CHANGED] = true;
+}
+sub append_before($$) {
+	my ($self, $text) = @_;
+
+	push(@{$self->[BEFORE]}, [0, "$text\n"]);
+	$self->[CHANGED] = true;
+}
+sub prepend_after($$) {
+	my ($self, $text) = @_;
+
+	unshift(@{$self->[AFTER]}, [0, "$text\n"]);
+	$self->[CHANGED] = true;
+}
+sub append_after($$) {
+	my ($self, $text) = @_;
+
+	push(@{$self->[AFTER]}, [0, "$text\n"]);
+	$self->[CHANGED] = true;
+}
+sub delete($) {
+	my ($self) = @_;
+
+	$self->[PHYSLINES] = [];
+	$self->[CHANGED] = true;
+}
+sub replace($$$) {
+	my ($self, $from, $to) = @_;
+	my $phys = $self->[PHYSLINES];
+
+	foreach my $i (0..$#{$phys}) {
+		if ($phys->[$i]->[0] != 0 && $phys->[$i]->[1] =~ s/\Q$from\E/$to/g) {
+			$self->[CHANGED] = true;
+		}
+	}
+}
+sub replace_regex($$$) {
+	my ($self, $from_re, $to) = @_;
+	my $phys = $self->[PHYSLINES];
+
+	foreach my $i (0..$#{$phys}) {
+		if ($phys->[$i]->[0] != 0 && $phys->[$i]->[1] =~ s/$from_re/$to/) {
+			$self->[CHANGED] = true;
+		}
+	}
+}
+sub set_text($$) {
+	my ($self, $text) = @_;
+	$self->[PHYSLINES] = [[0, "$text\n"]];
+	$self->[CHANGED] = true;
+}
diff --git a/pkgtools/pkglint4/files/PkgLint/Logging.pm b/pkgtools/pkglint4/files/PkgLint/Logging.pm
new file mode 100644
index 00000000000..eecb17a6a59
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/Logging.pm
@@ -0,0 +1,134 @@
+# $NetBSD: Logging.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# Subroutines for printing messages to the user in a common format.
+# The subroutines all have the parameters C<$fname>,
+# C<$lineno> and C<$message>. In case there's no appropriate filename for
+# the message, NO_FILE may be passed, likewise for C<$lineno> and
+# NO_LINES. Before printing, the filename is normalized, that is,
+# "/foo/bar/../../" components are removed, as well as "." components.
+# At the end of the program, the subroutine print_summary_and_exit should
+# be called.
+#
+# Examples:
+#   log_error(NO_FILE, NO_LINES, "Invalid command line.");
+#   log_warning($fname, NO_LINES, "Not found.");
+#   log_debug($fname, $lineno, sprintf("invalid character (0x%02x).", $c));
+#
+package PkgLint::Logging;
+
+use strict;
+use warnings;
+
+BEGIN {
+	use Exporter;
+	use vars qw(@ISA @EXPORT_OK);
+	@ISA = qw(Exporter);
+	@EXPORT_OK = qw(
+		NO_FILE NO_LINE_NUMBER NO_LINES
+		log_fatal log_error log_warning log_note log_debug
+		explain_error explain_warning explain_info
+		print_summary_and_exit
+		set_explain set_gcc_output_format
+		get_show_source_flag set_show_source_flag
+	);
+	import PkgLint::Util qw(
+		false true
+		normalize_pathname
+	);
+}
+
+use constant NO_FILE		=> undef;
+use constant NO_LINE_NUMBER	=> undef;
+use constant NO_LINES		=> undef;
+
+use enum qw(:LL_ FATAL ERROR WARNING NOTE DEBUG);
+
+use constant traditional_type	=> ["FATAL", "ERROR", "WARN", "NOTE", "DEBUG"];
+use constant gcc_type		=> ["fatal", "error", "warning", "note", "debug"];
+
+my $errors		= 0;
+my $warnings		= 0;
+my $gcc_output_format	= false;
+my $explain_flag	= false;
+my $show_source_flag	= false;
+
+sub strxvis($) {
+	my ($s) = @_;
+
+	$s =~ s/([^\x09\x20-\x7e])/"\\x" . unpack("H*", $1)/eg;
+	return $s;
+}
+
+sub log_message { # no prototype due to Perl weirdness
+	my ($level, $fname, $lineno, $message) = @_;
+	my ($text, $sep);
+
+	if (defined($fname)) {
+		$fname = normalize_pathname($fname);
+	}
+
+	$text = "";
+	$sep = "";
+	if (!$gcc_output_format) {
+		$text .= "${sep}" . traditional_type->[$level] . ":";
+		$sep = " ";
+	}
+	if (defined($fname)) {
+		$text .= defined($lineno)
+		    ? "${sep}${fname}:${lineno}"
+		    : "${sep}${fname}";
+		$sep = ": ";
+	}
+	if ($gcc_output_format) {
+		$text .= "${sep}" . gcc_type->[$level] . ":";
+		$sep = " ";
+	}
+	if (defined($message)) {
+		$text .= $sep . strxvis($message);
+		$sep = "";
+	}
+
+	if ($level == LL_FATAL) {
+		print STDERR ("${text}\n");
+	} else {
+		print STDOUT ("${text}\n");
+	}
+}
+
+sub log_fatal($$$)		{ log_message(LL_FATAL, @_); exit(1); }
+sub log_error($$$)		{ log_message(LL_ERROR, @_); $errors++; }
+sub log_warning($$$)		{ log_message(LL_WARNING, @_); $warnings++; }
+sub log_note($$$)		{ log_message(LL_NOTE, @_); }
+sub log_debug($$$)		{ log_message(LL_DEBUG, @_); }
+
+sub explain { # no prototype due to Perl weirdness
+	my ($loglevel, $fname, $lines, @texts) = @_;
+	my $out = ($loglevel == LL_FATAL) ? *STDERR : *STDOUT;
+
+	if ($explain_flag) {
+		foreach my $text ("", @texts, "") {
+			print $out ("\t${text}\n");
+		}
+	}
+}
+sub explain_error($$@)		{ explain(LL_ERROR, @_); }
+sub explain_warning($$@)	{ explain(LL_WARNING, @_); }
+sub explain_note($$@)		{ explain(LL_NOTE, @_); }
+
+sub print_summary_and_exit($) {
+	my ($quiet) = @_;
+
+	if (!$quiet) {
+		if ($errors != 0 || $warnings != 0) {
+			print("$errors errors and $warnings warnings found." . ($explain_flag ? "" : " (Use -e for more details.)") . "\n");
+		} else {
+			print "looks fine.\n";
+		}
+	}
+	exit($errors != 0);
+}
+
+sub set_explain()		{ $explain_flag = true; }
+sub set_gcc_output_format()	{ $gcc_output_format = true; }
+sub get_show_source_flag()	{ return $show_source_flag; }
+sub set_show_source_flag()	{ $show_source_flag = true; }
diff --git a/pkgtools/pkglint4/files/PkgLint/Patches.pm b/pkgtools/pkglint4/files/PkgLint/Patches.pm
new file mode 100644
index 00000000000..b96e7daa5f6
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/Patches.pm
@@ -0,0 +1,639 @@
+# $NetBSD: Patches.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# Everything concerning checks for patch files.
+#
+
+use strict;
+use warnings;
+
+# Guess the type of file based on the filename. This is used to select
+# the proper subroutine for detecting absolute pathnames.
+#
+# Returns one of "source", "shell", "make", "text", "configure",
+# "ignore", "unknown".
+#
+sub get_filetype($$) {
+	my ($line, $fname) = @_;
+	my $basename = basename($fname);
+
+	# The trailig .in part is not needed, since it does not
+	# influence the type of contents.
+	$basename =~ s,\.in$,,;
+
+	# Let's assume that everything else that looks like a Makefile
+	# is indeed a Makefile.
+	if ($basename =~ m"^I?[Mm]akefile(?:\..*|)?|.*\.ma?k$") {
+		return "make";
+	}
+
+	# Too many false positives for shell scripts, so configure
+	# scripts get their own category.
+	if ($basename =~ m"^configure(?:|\.ac)$") {
+		$opt_debug_unchecked and $line->log_debug("Skipped check for absolute pathnames.");
+		return "configure";
+	}
+
+	if ($basename =~ m"\.(?:sh|m4)$"i) {
+		return "shell";
+	}
+
+	if ($basename =~ m"\.(?:cc?|cpp|cxx|el|hh?|hpp|l|pl|pm|py|s|t|y)$"i) {
+		return "source";
+	}
+
+	if ($basename =~ m"^.+\.(?:\d+|conf|html|info|man|po|tex|texi|texinfo|txt|xml)$"i) {
+		return "text";
+	}
+
+	# Filenames without extension are hard to guess right. :(
+	if ($basename !~ m"\.") {
+		return "unknown";
+	}
+
+	$opt_debug_misc and $line->log_debug("Don't know the file type of ${fname}.");
+
+	return "unknown";
+}
+
+sub checkline_cpp_macro_names($$) {
+	my ($line, $text) = @_;
+	my ($rest);
+
+	use constant good_macros => PkgLint::Util::array_to_hash(qw(
+		__STDC__
+
+		__GNUC__ __GNUC_MINOR__
+		__SUNPRO_C
+
+		__i386
+		__mips
+		__sparc
+
+		__APPLE__
+		__bsdi__
+		__CYGWIN__
+		__DragonFly__
+		__FreeBSD__ __FreeBSD_version
+		__INTERIX
+		__linux__
+		__MINGW32__
+		__NetBSD__ __NetBSD_Version__
+		__OpenBSD__
+		__SVR4
+		__sgi
+		__sun
+
+		__GLIBC__
+	));
+	use constant bad_macros  => {
+		"__sgi__" => "__sgi",
+		"__sparc__" => "__sparc",
+		"__sparc_v9__" => "__sparcv9",
+		"__sun__" => "__sun",
+		"__svr4__" => "__SVR4",
+	};
+
+	$rest = $text;
+	while ($rest =~ s/defined\((__[\w_]+)\)// || $rest =~ s/\b(_\w+)\(//) {
+		my ($macro) = ($1);
+
+		if (exists(good_macros->{$macro})) {
+			$opt_debug_misc and $line->log_debug("Found good macro \"${macro}\".");
+		} elsif (exists(bad_macros->{$macro})) {
+			$line->log_warning("The macro \"${macro}\" is not portable enough. Please use \"".bad_macros->{$macro}."\" instead.");
+			$line->explain_warning("See the pkgsrc guide, section \"CPP defines\" for details.");
+
+		} elsif ($macro eq "__NetBSD_Prereq__") {
+			$line->log_warning("Please use __NetBSD_Version__ instead of __NetBSD_Prereq__.");
+			$line->explain_warning(
+"The __NetBSD_Prereq__ macro is pretty new. It was born in NetBSD",
+"4.99.3, and maybe it won't survive for long. A better (and compatible)",
+"way is to compare __NetBSD_Version__ directly to the required version",
+"number.");
+
+		} elsif ($macro =~ m"^_+NetBSD_+Version_+$"i && $macro ne "__NetBSD_Version__") {
+			$line->log_warning("Misspelled variant \"${macro}\" of \"__NetBSD_Version__\".");
+
+		} else {
+			$opt_debug_unchecked and $line->log_debug("Unchecked macro \"${macro}\".");
+		}
+	}
+}
+
+# Checks whether the line contains text that looks like absolute
+# pathnames, assuming that the file uses the common syntax with
+# single or double quotes to represent strings.
+#
+sub checkline_source_absolute_pathname($$) {
+	my ($line, $text) = @_;
+	my ($abspath);
+
+	$opt_debug_trace and $line->log_debug("checkline_source_absolute_pathname(${text})");
+
+	if ($text =~ m"(.*)([\"'])(/[^\"']*)\2") {
+		my ($before, $delim, $string) = ($1, $2, $3);
+
+		$opt_debug_misc and $line->log_debug("checkline_source_absolute_pathname(before=${before}, string=${string})");
+		if ($before =~ m"[A-Z_]+\s*$") {
+			# allowed: PREFIX "/bin/foo"
+
+		} elsif ($string =~ m"^/[*/]") {
+			# This is more likely to be a C or C++ comment.
+
+		} elsif ($string !~ m"^/\w") {
+			# Assume that pathnames start with a letter or digit.
+
+		} elsif ($before =~ m"\+\s*$") {
+			# Something like foodir + '/lib'
+
+		} else {
+			$abspath = $string;
+		}
+	}
+
+	if (defined($abspath)) {
+		checkword_absolute_pathname($line, $abspath);
+	}
+}
+
+# Last resort if the file does not look like a Makefile or typical
+# source code. All strings that look like pathnames and start with
+# one of the typical Unix prefixes are found.
+#
+sub checkline_other_absolute_pathname($$) {
+	my ($line, $text) = @_;
+
+	$opt_debug_trace and $line->log_debug("checkline_other_absolute_pathname(\"${text}\")");
+
+	if ($text =~ m"^#[^!]") {
+		# Don't warn for absolute pathnames in comments,
+		# except for shell interpreters.
+
+	} elsif ($text =~ m"^(.*?)((?:/[\w.]+)*/(?:bin|dev|etc|home|lib|mnt|opt|proc|sbin|tmp|usr|var)\b[\w./\-]*)(.*)$") {
+		my ($before, $path, $after) = ($1, $2, $3);
+
+		if ($before =~ m"\@$") {
+			# Something like @PREFIX@/bin
+
+		} elsif ($before =~ m"[)}]$") {
+			# Something like ${prefix}/bin or $(PREFIX)/bin
+
+		} elsif ($before =~ m"\+\s*[\"']$") {
+			# Something like foodir + '/lib'
+
+		} elsif ($before =~ m"\w$") {
+			# Something like $dir/lib
+
+		} elsif ($before =~ m"\.$") {
+			# ../foo is not an absolute pathname.
+
+		} else {
+			$opt_debug_misc and $line->log_debug("before=${before}");
+			checkword_absolute_pathname($line, $path);
+		}
+	}
+}
+
+sub checkfile_patch($) {
+	my ($fname) = @_;
+	my ($lines);
+	my ($state, $redostate, $nextstate, $dellines, $addlines, $hunks);
+	my ($seen_comment, $current_fname, $current_ftype, $patched_files);
+	my ($leading_context_lines, $trailing_context_lines, $context_scanning_leading);
+
+	# Abbreviations used:
+	# style: [c] = context diff, [u] = unified diff
+	# scope: [f] = file, [h] = hunk, [l] = line
+	# action: [d] = delete, [m] = modify, [a] = add, [c] = context
+	use constant re_patch_rcsid	=> qr"^\$.*\$$";
+	use constant re_patch_text	=> qr"^(.+)$";
+	use constant re_patch_empty	=> qr"^$";
+	use constant re_patch_cfd	=> qr"^\*\*\*\s(\S+)(.*)$";
+	use constant re_patch_cfa	=> qr"^---\s(\S+)(.*)$";
+	use constant re_patch_ch	=> qr"^\*{15}(.*)$";
+	use constant re_patch_chd	=> qr"^\*{3}\s(\d+)(?:,(\d+))?\s\*{4}$";
+	use constant re_patch_cha	=> qr"^-{3}\s(\d+)(?:,(\d+))?\s-{4}$";
+	use constant re_patch_cld	=> qr"^(?:-\s(.*))?$";
+	use constant re_patch_clm	=> qr"^(?:!\s(.*))?$";
+	use constant re_patch_cla	=> qr"^(?:\+\s(.*))?$";
+	use constant re_patch_clc	=> qr"^(?:\s\s(.*))?$";
+	use constant re_patch_ufd	=> qr"^---\s(\S+)(?:\s+(.*))?$";
+	use constant re_patch_ufa	=> qr"^\+{3}\s(\S+)(?:\s+(.*))?$";
+	use constant re_patch_uh	=> qr"^\@\@\s-(?:(\d+),)?(\d+)\s\+(?:(\d+),)?(\d+)\s\@\@(.*)$";
+	use constant re_patch_uld	=> qr"^-(.*)$";
+	use constant re_patch_ula	=> qr"^\+(.*)$";
+	use constant re_patch_ulc	=> qr"^\s(.*)$";
+	use constant re_patch_ulnonl	=> qr"^\\ No newline at end of file$";
+
+	use enum qw(:PST_
+		START CENTER TEXT
+		CFA CH CHD CLD0 CLD CLA0 CLA
+		UFA UH UL
+	);
+
+	my @comment_explanation = (
+"Each patch must document why it is necessary. If it has been applied",
+"because of a security issue, a reference to the CVE should be mentioned",
+"as well.",
+"",
+"Since it is our goal to have as few patches as possible, all patches",
+"should be sent to the upstream maintainers of the package. After you",
+"have done so, you should add a reference to the bug report containing",
+"the patch.");
+
+	my ($line, $m);
+
+	my $check_text = sub($) {
+		my ($text) = @_;
+
+		if ($text =~ m"(\$(Author|Date|Header|Id|Locker|Log|Name|RCSfile|Revision|Source|State|$opt_rcsidstring)(?::[^\$]*)?\$)") {
+			my ($tag) = ($2);
+
+			if ($text =~ re_patch_uh) {
+				$line->log_warning("Found RCS tag \"\$${tag}\$\". Please remove it.");
+				$line->set_text($1);
+			} else {
+				$line->log_warning("Found RCS tag \"\$${tag}\$\". Please remove it by reducing the number of context lines using pkgdiff or \"diff -U[210]\".");
+			}
+		}
+	};
+
+	my $check_contents = sub() {
+
+		if ($m->has(1)) {
+			$check_text->($m->text(1));
+		}
+	};
+
+	my $check_added_contents = sub() {
+		my $text;
+
+		return unless $m->has(1);
+		$text = $m->text(1);
+		checkline_cpp_macro_names($line, $text);
+
+		# XXX: This check is not as accurate as the similar one in
+		# checkline_mk_shelltext().
+		if (defined($current_fname)) {
+			if ($current_ftype eq "shell" || $current_ftype eq "make") {
+				my ($mm, $rest) = match_all($text, $regex_shellword);
+
+				foreach my $m (@{$mm}) {
+					my $shellword = $m->text(1);
+
+					if ($shellword =~ m"^#") {
+						last;
+					}
+					checkline_mk_absolute_pathname($line, $shellword);
+				}
+
+			} elsif ($current_ftype eq "source") {
+				checkline_source_absolute_pathname($line, $text);
+
+			} elsif ($current_ftype eq "configure") {
+				if ($text =~ m": Avoid regenerating within pkgsrc$") {
+					$line->log_error("This code must not be included in patches.");
+					$line->explain_error(
+"It is generated automatically by pkgsrc after the patch phase.",
+"",
+"For more details, look for \"configure-scripts-override\" in",
+"mk/configure/gnu-configure.mk.");
+				}
+
+			} elsif ($current_ftype eq "ignore") {
+				# Ignore it.
+
+			} else {
+				checkline_other_absolute_pathname($line, $text);
+			}
+		}
+	};
+
+	my $check_hunk_end = sub($$$) {
+		my ($deldelta, $adddelta, $newstate) = @_;
+
+		if ($deldelta > 0 && $dellines == 0) {
+			$redostate = $newstate;
+			if (defined($addlines) && $addlines > 0) {
+				$line->log_error("Expected ${addlines} more lines to be added.");
+			}
+		} elsif ($adddelta > 0 && $addlines == 0) {
+			$redostate = $newstate;
+			if (defined($dellines) && $dellines > 0) {
+				$line->log_error("Expected ${dellines} more lines to be deleted.");
+			}
+		} else {
+			if (defined($context_scanning_leading)) {
+				if ($deldelta != 0 && $adddelta != 0) {
+					if ($context_scanning_leading) {
+						$leading_context_lines++;
+					} else {
+						$trailing_context_lines++;
+					}
+				} else {
+					if ($context_scanning_leading) {
+						$context_scanning_leading = false;
+					} else {
+						$trailing_context_lines = 0;
+					}
+				}
+			}
+
+			if ($deldelta != 0) {
+				$dellines -= $deldelta;
+			}
+			if ($adddelta != 0) {
+				$addlines -= $adddelta;
+			}
+			if (!((defined($dellines) && $dellines > 0) ||
+			      (defined($addlines) && $addlines > 0))) {
+				if (defined($context_scanning_leading)) {
+					if ($leading_context_lines != $trailing_context_lines) {
+						$opt_debug_patches and $line->log_warning("The hunk that ends here does not have as many leading (${leading_context_lines}) as trailing (${trailing_context_lines}) lines of context.");
+					}
+				}
+				$nextstate = $newstate;
+			}
+		}
+	};
+
+	# @param deldelta
+	#	The number of lines that are deleted from the patched file.
+	# @param adddelta
+	#	The number of lines that are added to the patched file.
+	# @param newstate
+	#	The follow-up state when this line is the last line to be
+	#	added in this hunk of the patch.
+	#
+	my $check_hunk_line = sub($$$) {
+		my ($deldelta, $adddelta, $newstate) = @_;
+
+		$check_contents->();
+		$check_hunk_end->($deldelta, $adddelta, $newstate);
+
+		# If -Wextra is given, the context lines are checked for
+		# absolute paths and similar things. If it is not given,
+		# only those lines that really add something to the patched
+		# file are checked.
+		if ($adddelta != 0 && ($deldelta == 0 || $opt_warn_extra)) {
+			$check_added_contents->();
+		}
+	};
+
+	# [ regex, to state, action ]
+	my $transitions = {
+		PST_START() =>
+		[   [re_patch_rcsid, PST_CENTER, sub() {
+			checkline_rcsid($line, "");
+		}], [undef, PST_CENTER, sub() {
+			checkline_rcsid($line, "");
+		}]],
+		PST_CENTER() =>
+		[   [re_patch_empty, PST_TEXT, sub() {
+			#
+		}], [re_patch_cfd, PST_CFA, sub() {
+			if ($seen_comment) {
+				$opt_warn_space and $line->log_note("Empty line expected.");
+			} else {
+				$line->log_error("Comment expected.");
+				$line->explain_error(@comment_explanation);
+			}
+			$line->log_warning("Please use unified diffs (diff -u) for patches.");
+		}], [re_patch_ufd, PST_UFA, sub() {
+			if ($seen_comment) {
+				$opt_warn_space and $line->log_note("Empty line expected.");
+			} else {
+				$line->log_error("Comment expected.");
+				$line->explain_error(@comment_explanation);
+			}
+		}], [undef, PST_TEXT, sub() {
+			$opt_warn_space and $line->log_note("Empty line expected.");
+		}]],
+		PST_TEXT() =>
+		[   [re_patch_cfd, PST_CFA, sub() {
+			if (!$seen_comment) {
+				$line->log_error("Comment expected.");
+				$line->explain_error(@comment_explanation);
+			}
+			$line->log_warning("Please use unified diffs (diff -u) for patches.");
+		}], [re_patch_ufd, PST_UFA, sub() {
+			if (!$seen_comment) {
+				$line->log_error("Comment expected.");
+				$line->explain_error(@comment_explanation);
+			}
+		}], [re_patch_text, PST_TEXT, sub() {
+			$seen_comment = true;
+		}], [re_patch_empty, PST_TEXT, sub() {
+			#
+		}], [undef, PST_TEXT, sub() {
+			#
+		}]],
+		PST_CFA() =>
+		[   [re_patch_cfa, PST_CH, sub() {
+			$current_fname = $m->text(1);
+			$current_ftype = get_filetype($line, $current_fname);
+			$opt_debug_patches and $line->log_debug("fname=$current_fname ftype=$current_ftype");
+			$patched_files++;
+			$hunks = 0;
+		}]],
+		PST_CH() =>
+		[   [re_patch_ch, PST_CHD, sub() {
+			$hunks++;
+		}]],
+		PST_CHD() =>
+		[   [re_patch_chd, PST_CLD0, sub() {
+			$dellines = ($m->has(2))
+			    ? (1 + $m->text(2) - $m->text(1))
+			    : ($m->text(1));
+		}]],
+		PST_CLD0() =>
+		[   [re_patch_clc, PST_CLD, sub() {
+			$check_hunk_line->(1, 0, PST_CLD0);
+		}], [re_patch_cld, PST_CLD, sub() {
+			$check_hunk_line->(1, 0, PST_CLD0);
+		}], [re_patch_clm, PST_CLD, sub() {
+			$check_hunk_line->(1, 0, PST_CLD0);
+		}], [re_patch_cha, PST_CLA0, sub() {
+			$dellines = undef;
+			$addlines = ($m->has(2))
+			    ? (1 + $m->text(2) - $m->text(1))
+			    : ($m->text(1));
+		}]],
+		PST_CLD() =>
+		[   [re_patch_clc, PST_CLD, sub() {
+			$check_hunk_line->(1, 0, PST_CLD0);
+		}], [re_patch_cld, PST_CLD, sub() {
+			$check_hunk_line->(1, 0, PST_CLD0);
+		}], [re_patch_clm, PST_CLD, sub() {
+			$check_hunk_line->(1, 0, PST_CLD0);
+		}], [undef, PST_CLD0, sub() {
+			if ($dellines != 0) {
+				$line->log_warning("Invalid number of deleted lines (${dellines} missing).");
+			}
+		}]],
+		PST_CLA0() =>
+		[   [re_patch_clc, PST_CLA, sub() {
+			$check_hunk_line->(0, 1, PST_CH);
+		}], [re_patch_clm, PST_CLA, sub() {
+			$check_hunk_line->(0, 1, PST_CH);
+		}], [re_patch_cla, PST_CLA, sub() {
+			$check_hunk_line->(0, 1, PST_CH);
+		}], [undef, PST_CH, sub() {
+			#
+		}]],
+		PST_CLA() =>
+		[   [re_patch_clc, PST_CLA, sub() {
+			$check_hunk_line->(0, 1, PST_CH);
+		}], [re_patch_clm, PST_CLA, sub() {
+			$check_hunk_line->(0, 1, PST_CH);
+		}], [re_patch_cla, PST_CLA, sub() {
+			$check_hunk_line->(0, 1, PST_CH);
+		}], [undef, PST_CLA0, sub() {
+			if ($addlines != 0) {
+				$line->log_warning("Invalid number of added lines (${addlines} missing).");
+			}
+		}]],
+		PST_CH() =>
+		[   [undef, PST_TEXT, sub() {
+			#
+		}]],
+		PST_UFA() =>
+		[   [re_patch_ufa, PST_UH, sub() {
+			$current_fname = $m->text(1);
+			$current_ftype = get_filetype($line, $current_fname);
+			$opt_debug_patches and $line->log_debug("fname=$current_fname ftype=$current_ftype");
+			$patched_files++;
+			$hunks = 0;
+		}]],
+		PST_UH() =>
+		[   [re_patch_uh, PST_UL, sub() {
+			$dellines = ($m->has(1) ? $m->text(2) : 1);
+			$addlines = ($m->has(3) ? $m->text(4) : 1);
+			$check_text->($line->text);
+			if ($line->text =~ m"\r$") {
+				$line->log_error("The hunk header must not end with a CR character.");
+				$line->explain_error(
+"The MacOS X patch utility cannot handle these.");
+			}
+			$hunks++;
+			$context_scanning_leading = (($m->has(1) && $m->text(1) ne "1") ? true : undef);
+			$leading_context_lines = 0;
+			$trailing_context_lines = 0;
+		}], [undef, PST_TEXT, sub() {
+			($hunks != 0) || $line->log_warning("No hunks for file ${current_fname}.");
+		}]],
+		PST_UL() =>
+		[   [re_patch_uld, PST_UL, sub() {
+			$check_hunk_line->(1, 0, PST_UH);
+		}], [re_patch_ula, PST_UL, sub() {
+			$check_hunk_line->(0, 1, PST_UH);
+		}], [re_patch_ulc, PST_UL, sub() {
+			$check_hunk_line->(1, 1, PST_UH);
+		}], [re_patch_ulnonl, PST_UL, sub() {
+			#
+		}], [re_patch_empty, PST_UL, sub() {
+			$opt_warn_space and $line->log_note("Leading white-space missing in hunk.");
+			$check_hunk_line->(1, 1, PST_UH);
+		}], [undef, PST_UH, sub() {
+			if ($dellines != 0 || $addlines != 0) {
+				$line->log_warning("Unexpected end of hunk (-${dellines},+${addlines} expected).");
+			}
+		}]]};
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_patch()");
+
+	checkperms($fname);
+	if (!($lines = load_lines($fname, false))) {
+		log_error($fname, NO_LINE_NUMBER, "Could not be read.");
+		return;
+	}
+	if (@{$lines} == 0) {
+		log_error($fname, NO_LINE_NUMBER, "Must not be empty.");
+		return;
+	}
+
+	$state = PST_START;
+	$dellines = undef;
+	$addlines = undef;
+	$patched_files = 0;
+	$seen_comment = false;
+	$current_fname = undef;
+	$current_ftype = undef;
+	$hunks = undef;
+
+	for (my $lineno = 0; $lineno <= $#{$lines}; ) {
+		$line = $lines->[$lineno];
+		my $text = $line->text;
+
+		$opt_debug_patches and $line->log_debug("[${state} ${patched_files}/".($hunks||0)."/-".($dellines||0)."+".($addlines||0)."] $text");
+
+		my $found = false;
+		foreach my $t (@{$transitions->{$state}}) {
+				if (!defined($t->[0])) {
+					$m = undef;
+				} elsif ($text =~ $t->[0]) {
+					$opt_debug_patches and $line->log_debug($t->[0]);
+					$m = PkgLint::SimpleMatch->new($text, \@-, \@+);
+				} else {
+					next;
+				}
+				$redostate = undef;
+				$nextstate = $t->[1];
+				$t->[2]->();
+				if (defined($redostate)) {
+					$state = $redostate;
+				} else {
+					$state = $nextstate;
+					if (defined($t->[0])) {
+						$lineno++;
+					}
+				}
+				$found = true;
+				last;
+		}
+
+		if (!$found) {
+			$line->log_error("Parse error: state=${state}");
+			$state = PST_TEXT;
+			$lineno++;
+		}
+	}
+
+	while ($state != PST_TEXT) {
+		$opt_debug_patches and log_debug($fname, "EOF", "[${state} ${patched_files}/".($hunks||0)."/-".($dellines||0)."+".($addlines||0)."]");
+
+		my $found = false;
+		foreach my $t (@{$transitions->{$state}}) {
+			if (!defined($t->[0])) {
+				my $newstate;
+
+				$m = undef;
+				$redostate = undef;
+				$nextstate = $t->[1];
+				$t->[2]->();
+				$newstate = (defined($redostate)) ? $redostate : $nextstate;
+				if ($newstate == $state) {
+					log_fatal($fname, "EOF", "Internal error in the patch transition table.");
+				}
+				$state = $newstate;
+				$found = true;
+				last;
+			}
+		}
+
+		if (!$found) {
+			log_error($fname, "EOF", "Parse error: state=${state}");
+			$state = PST_TEXT;
+		}
+	}
+
+	if ($patched_files > 1) {
+		log_warning($fname, NO_LINE_NUMBER, "Contains patches for $patched_files files, should be only one.");
+
+	} elsif ($patched_files == 0) {
+		log_error($fname, NO_LINE_NUMBER, "Contains no patch.");
+	}
+
+	checklines_trailing_empty_lines($lines);
+}
+
diff --git a/pkgtools/pkglint4/files/PkgLint/Shell.pm b/pkgtools/pkglint4/files/PkgLint/Shell.pm
new file mode 100644
index 00000000000..c9251b9ba04
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/Shell.pm
@@ -0,0 +1,708 @@
+# $NetBSD: Shell.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# Parsing and checking shell commands embedded in Makefiles
+#
+
+sub checkline_mk_shellword($$$) {
+	my ($line, $shellword, $check_quoting) = @_;
+	my ($rest, $state, $value);
+
+	$opt_debug_trace and $line->log_debug("checkline_mk_shellword(\"${shellword}\", ${check_quoting}).");
+	use constant shellcommand_context_type => PkgLint::Type->new(
+		LK_NONE, "ShellCommand", [[ qr".*", "adsu" ]], NOT_GUESSED
+	);
+	use constant shellword_vuc => PkgLint::VarUseContext->new(
+		VUC_TIME_UNKNOWN,
+		shellcommand_context_type,
+		VUC_SHELLWORD_PLAIN,
+		VUC_EXTENT_WORD
+	);
+
+	if ($shellword =~ m"^\$\{(${regex_varname})(:[^{}]+)?\}$") {
+		my ($varname, $mod) = ($1, $2);
+
+		checkline_mk_varuse($line, $varname, defined($mod) ? $mod : "", shellword_vuc);
+		return;
+	}
+
+	if ($shellword =~ m"\$\{PREFIX\}/man(?:$|/)") {
+		$line->log_warning("Please use \${PKGMANDIR} instead of \"man\".");
+	}
+
+	if ($shellword =~ m"etc/rc\.d") {
+		$line->log_warning("Please use the RCD_SCRIPTS mechanism to install rc.d scripts automatically to \${RCD_SCRIPTS_EXAMPLEDIR}.");
+	}
+
+	# Note: SWST means [S]hell[W]ord [ST]ate
+	use enum qw(:SWST_ PLAIN SQUOT DQUOT DQUOT_BACKT BACKT);
+	use constant statename		=> [
+		"SWST_PLAIN", "SWST_SQUOT", "SWST_DQUOT",
+		"SWST_DQUOT_BACKT", "SWST_BACKT",
+	];
+	use constant user_statename	=> [
+		"unquoted string", "single quoted string",
+		"double quoted string", "backticks inside double quoted string",
+		"backticks",
+	];
+
+	$rest = ($shellword =~ m"^#") ? "" : $shellword;
+	$state = SWST_PLAIN;
+	while ($rest ne "") {
+
+		$opt_debug_shell and $line->log_debug(statename->[$state] . ": ${rest}");
+
+		# When we are parsing inside backticks, it is more
+		# reasonable to check the whole shell command
+		# recursively, instead of splitting off the first
+		# make(1) variable (see the elsif below).
+		if ($state == SWST_BACKT || $state == SWST_DQUOT_BACKT) {
+
+			# Scan for the end of the backticks, checking
+			# for single backslashes and removing one level
+			# of backslashes. Backslashes are only removed
+			# before a dollar, a backslash or a backtick.
+			#
+			# References:
+			# * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_03
+			my $stripped = "";
+			while ($rest ne "") {
+				if ($rest =~ s/^\`//) { #`
+					$state = ($state == SWST_BACKT) ? SWST_PLAIN : SWST_DQUOT;
+					goto end_of_backquotes;
+				} elsif ($rest =~ s/^\\([\\\`\$])//) { #`
+					$stripped .= $1;
+				} elsif ($rest =~ s/^(\\)//) {
+					$line->log_warning("Backslashes should be doubled inside backticks.");
+					$stripped .= $1;
+				} elsif ($state == SWST_DQUOT_BACKT && $rest =~ s/^"//) { #"
+					$line->log_warning("Double quotes inside backticks inside double quotes are error prone.");
+					$line->explain_warning(
+"According to the SUSv3, they produce undefined results.",
+"",
+"See the paragraph starting \"Within the backquoted ...\" in",
+"http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html");
+				} elsif ($rest =~ s/^([^\\\`]+)//) { #`
+					$stripped .= $1;
+				} else {
+					assert(false, "rest=$rest");
+				}
+			}
+			$line->log_error("Unfinished backquotes: rest=$rest");
+
+		end_of_backquotes:
+			# Check the resulting command.
+			checkline_mk_shelltext($line, $stripped);
+
+		# make(1) variables have the same syntax, no matter in
+		# which state we are currently.
+		} elsif ($rest =~ s/^\$\{(${regex_varname}|[\@])(:[^\{]+)?\}//
+		||  $rest =~ s/^\$\((${regex_varname}|[\@])(:[^\)]+)?\)//
+		||  $rest =~ s/^\$([\w\@])//) {
+			my ($varname, $mod) = ($1, $2);
+
+			if ($varname eq "\@") {
+				$line->log_warning("Please use \"\${.TARGET}\" instead of \"\$\@\".");
+				$line->explain_warning(
+"The variable \$\@ can easily be confused with the shell variable of the",
+"same name, which has a completely different meaning.");
+				$varname = ".TARGET";
+			}
+
+			if ($state == SWST_PLAIN && defined($mod) && $mod =~ m":Q$") {
+				# Fine.
+
+			} elsif ($state == SWST_BACKT) {
+				# Don't check here, to avoid false positives
+				# for tool names.
+
+			} elsif (($state == SWST_SQUOT || $state == SWST_DQUOT) && $varname =~ m"^(?:.*DIR|.*FILE|.*PATH|.*_VAR|PREFIX|.*BASE|PKGNAME)$") {
+				# This is ok if we don't allow these
+				# variables to have embedded [\$\\\"\'\`].
+
+			} elsif ($state == SWST_DQUOT && defined($mod) && $mod =~ m":Q$") {
+				$line->log_warning("Please don't use the :Q operator in double quotes.");
+				$line->explain_warning(
+"Either remove the :Q or the double quotes. In most cases, it is more",
+"appropriate to remove the double quotes.");
+
+			}
+
+			my $ctx = PkgLint::VarUseContext->new_from_pool(
+				VUC_TIME_UNKNOWN,
+				shellcommand_context_type,
+				  ($state == SWST_PLAIN) ? VUC_SHELLWORD_PLAIN
+				: ($state == SWST_DQUOT) ? VUC_SHELLWORD_DQUOT
+				: ($state == SWST_SQUOT) ? VUC_SHELLWORD_SQUOT
+				: ($state == SWST_BACKT) ? VUC_SHELLWORD_BACKT
+				: VUC_SHELLWORD_UNKNOWN,
+				VUC_EXTENT_WORD_PART
+			);
+			if ($varname ne "\@") {
+				checkline_mk_varuse($line, $varname, defined($mod) ? $mod : "", $ctx);
+			}
+
+		# The syntax of the variable modifiers can get quite
+		# hairy. In lack of motivation, we just skip anything
+		# complicated, hoping that at least the braces are
+		# balanced.
+		} elsif ($rest =~ s/^\$\{//) {
+			my $braces = 1;
+			while ($rest ne "" && $braces > 0) {
+				if ($rest =~ s/^\}//) {
+					$braces--;
+				} elsif ($rest =~ s/^\{//) {
+					$braces++;
+				} elsif ($rest =~ s/^[^{}]+//) {
+					# Nothing to do here.
+				} else {
+					last;
+				}
+			}
+
+		} elsif ($state == SWST_PLAIN) {
+
+			# XXX: This is only true for the "first" word in a
+			# shell command, not for every word. For example,
+			# FOO_ENV+= VAR=`command` may be underquoted.
+			if (false && $rest =~ m"([\w_]+)=\"\`") {
+				$line->log_note("In the assignment to \"$1\", you don't need double quotes around backticks.");
+				$line->explain_note(
+"Assignments are a special context, where no double quotes are needed",
+"around backticks. In other contexts, the double quotes are necessary.");
+			}
+
+			if ($rest =~ s/^[!#\%&\(\)*+,\-.\/0-9:;<=>?\@A-Z\[\]^_a-z{|}~]+//) {
+			} elsif ($rest =~ s/^\'//) {
+				$state = SWST_SQUOT;
+			} elsif ($rest =~ s/^\"//) {
+				$state = SWST_DQUOT;
+			} elsif ($rest =~ s/^\`//) { #`
+				$state = SWST_BACKT;
+			} elsif ($rest =~ s/^\\(?:[ !"#'\(\)*;?\\^{|}]|\$\$)//) {
+			} elsif ($rest =~ s/^\$\$([0-9A-Z_a-z]+|\#)//
+			    || $rest =~ s/^\$\$\{([0-9A-Z_a-z]+|\#)\}//
+			    || $rest =~ s/^\$\$(\$)\$//) {
+				my ($shvarname) = ($1);
+				if ($opt_warn_quoting && $check_quoting) {
+					$line->log_warning("Unquoted shell variable \"${shvarname}\".");
+					$line->explain_warning(
+"When a shell variable contains white-space, it is expanded (split into", 
+"multiple words) when it is written as \$variable in a shell script.",
+"If that is not intended, you should add quotation marks around it,",
+"like \"\$variable\". Then, the variable will always expand to a single",
+"word, preserving all white-space and other special characters.",
+"",
+"Example:",
+"\tfname=\"Curriculum vitae.doc\"",
+"\tcp \$fname /tmp",
+"\t# tries to copy the two files \"Curriculum\" and \"Vitae.doc\"",
+"\tcp \"\$fname\" /tmp",
+"\t# copies one file, as intended");
+				}
+
+			} elsif ($rest =~ s/^\$\@//) {
+				$line->log_warning("Please use \"\${.TARGET}\" instead of \"\$@\".");
+				$line->explain_warning(
+"It is more readable and prevents confusion with the shell variable of",
+"the same name.");
+
+			} elsif ($rest =~ s/^\$\$\@//) {
+				$line->log_warning("The \$@ shell variable should only be used in double quotes.");
+
+			} elsif ($rest =~ s/^\$\$\?//) {
+				$line->log_warning("The \$? shell variable is often not available in \"set -e\" mode.");
+
+			} elsif ($rest =~ s/^\$\$\(/(/) {
+				$line->log_warning("Invoking subshells via \$(...) is not portable enough.");
+				$line->explain_warning(
+"The Solaris /bin/sh does not know this way to execute a command in a",
+"subshell. Please use backticks (\`...\`) as a replacement.");
+
+			} else {
+				last;
+			}
+
+		} elsif ($state == SWST_SQUOT) {
+			if ($rest =~ s/^\'//) {
+				$state = SWST_PLAIN;
+			} elsif ($rest =~ s/^[^\$\']+//) { #'
+			} elsif ($rest =~ s/^\$\$//) {
+			} else {
+				last;
+			}
+
+		} elsif ($state == SWST_DQUOT) {
+			if ($rest =~ s/^\"//) {
+				$state = SWST_PLAIN;
+			} elsif ($rest =~ s/^\`//) { #`
+				$state = SWST_DQUOT_BACKT;
+			} elsif ($rest =~ s/^[^\$"\\\`]+//) { #`
+			} elsif ($rest =~ s/^\\(?:[\\\"\`]|\$\$)//) { #`
+			} elsif ($rest =~ s/^\$\$\{([0-9A-Za-z_]+)\}//
+			    || $rest =~ s/^\$\$([0-9A-Z_a-z]+|[!#?\@]|\$\$)//) {
+				my ($shvarname) = ($1);
+				$opt_debug_shell and $line->log_debug("[checkline_mk_shellword] Found double-quoted variable ${shvarname}.");
+			} elsif ($rest =~ s/^\$\$//) {
+				$line->log_warning("Unquoted \$ or strange shell variable found.");
+			} elsif ($rest =~ s/^\\(.)//) {
+				my ($char) = ($1);
+				$line->log_warning("Please use \"\\\\${char}\" instead of \"\\${char}\".");
+				$line->explain_warning(
+"Although the current code may work, it is not good style to rely on",
+"the shell passing \"\\${char}\" exactly as is, and not discarding the",
+"backslash. Alternatively you can use single quotes instead of double",
+"quotes.");
+			} else {
+				last;
+			}
+
+		} else {
+			last;
+		}
+	}
+	if ($rest !~ m"^\s*$") {
+		$line->log_error("Internal pkglint error: " . statename->[$state] . ": rest=${rest}");
+	}
+}
+
+# Some shell commands should not be used in the install phase.
+#
+sub checkline_mk_shellcmd_use($$) {
+	my ($line, $shellcmd) = @_;
+
+	use constant allowed_install_commands => array_to_hash(qw(
+		${INSTALL}
+		${INSTALL_DATA} ${INSTALL_DATA_DIR}
+		${INSTALL_LIB} ${INSTALL_LIB_DIR}
+		${INSTALL_MAN} ${INSTALL_MAN_DIR}
+		${INSTALL_PROGRAM} ${INSTALL_PROGRAM_DIR}
+		${INSTALL_SCRIPT}
+		${LIBTOOL}
+		${LN}
+		${PAX}
+	));
+	use constant discouraged_install_commands => array_to_hash(qw(
+		sed ${SED}
+		tr ${TR}
+	));
+
+	if (defined($mkctx_target) && $mkctx_target =~ m"^(?:pre|do|post)-install") {
+
+		if (exists(allowed_install_commands->{$shellcmd})) {
+			# Fine.
+
+		} elsif (exists(discouraged_install_commands->{$shellcmd})) {
+			$line->log_warning("The shell command \"${shellcmd}\" should not be used in the install phase.");
+			$line->explain_warning(
+"In the install phase, the only thing that should be done is to install",
+"the prepared files to their final location. The file's contents should",
+"not be changed anymore.");
+
+		} elsif ($shellcmd eq "\${CP}") {
+			$line->log_warning("\${CP} should not be used to install files.");
+			$line->explain_warning(
+"The \${CP} command is highly platform dependent and cannot overwrite",
+"files that don't have write permission. Please use \${PAX} instead.",
+"",
+"For example, instead of",
+"\t\${CP} -R \${WRKSRC}/* \${PREFIX}/foodir",
+"you should use",
+"\tcd \${WRKSRC} && \${PAX} -wr * \${PREFIX}/foodir");
+
+		} else {
+			$opt_debug_misc and $line->log_debug("May \"${shellcmd}\" be used in the install phase?");
+		}
+	}
+}
+
+sub checkline_mk_shelltext($$) {
+	my ($line, $text) = @_;
+	my ($vartools, $state, $rest, $set_e_mode);
+
+	$opt_debug_trace and $line->log_debug("checkline_mk_shelltext(\"$text\")");
+
+	# Note: SCST is the abbreviation for [S]hell [C]ommand [ST]ate.
+	use constant scst => qw(
+		START CONT
+		INSTALL INSTALL_D
+		MKDIR
+		PAX PAX_S
+		SED SED_E
+		SET SET_CONT
+		COND COND_CONT
+		CASE CASE_IN CASE_LABEL CASE_LABEL_CONT CASE_PAREN
+		FOR FOR_IN FOR_CONT
+		ECHO
+		INSTALL_DIR INSTALL_DIR2
+	);
+	use enum (":SCST_", scst);
+	use constant scst_statename => [ map { "SCST_$_" } scst ];
+
+	use constant forbidden_commands => array_to_hash(qw(
+		ktrace
+		mktexlsr
+		strace
+		texconfig truss
+	));
+
+	if ($text =~ m"\$\{SED\}" && $text =~ m"\$\{MV\}") {
+		$line->log_note("Please use the SUBST framework instead of \${SED} and \${MV}.");
+		$line->explain_note(
+"When converting things, pay attention to \"#\" characters. In shell",
+"commands make(1) does not interpret them as comment character, but",
+"in other lines it does. Therefore, instead of the shell command",
+"",
+"\tsed -e 's,#define foo,,'",
+"",
+"you need to write",
+"",
+"\tSUBST_SED.foo+=\t's,\\#define foo,,'");
+	}
+
+	if ($text =~ m"^\@*-(.*(MKDIR|INSTALL.*-d|INSTALL_.*_DIR).*)") {
+		my ($mkdir_cmd) = ($1);
+
+		$line->log_note("You don't need to use \"-\" before ${mkdir_cmd}.");
+	}
+
+	$vartools = get_vartool_names();
+	$rest = $text;
+
+	use constant hidden_shell_commands => array_to_hash(qw(
+		${DELAYED_ERROR_MSG} ${DELAYED_WARNING_MSG}
+		${DO_NADA}
+		${ECHO} ${ECHO_MSG} ${ECHO_N} ${ERROR_CAT} ${ERROR_MSG}
+		${FAIL_MSG}
+		${PHASE_MSG} ${PRINTF}
+		${SHCOMMENT} ${STEP_MSG}
+		${WARNING_CAT} ${WARNING_MSG}
+	));
+
+	$set_e_mode = false;
+
+	if ($rest =~ s/^\s*([-@]*)(\$\{_PKG_SILENT\}\$\{_PKG_DEBUG\}|\$\{RUN\}|)//) {
+		my ($hidden, $macro) = ($1, $2);
+
+		if ($hidden !~ m"\@") {
+			# Nothing is hidden at all.
+
+		} elsif (defined($mkctx_target) && $mkctx_target =~ m"^(?:show-.*|.*-message)$") {
+			# In some targets commands may be hidden.
+
+		} elsif ($rest =~ m"^#") {
+			# Shell comments may be hidden, as they have no side effects
+
+		} elsif ($rest =~ $regex_shellword) {
+			my ($cmd) = ($1);
+
+			if (!exists(hidden_shell_commands->{$cmd})) {
+				$line->log_warning("The shell command \"${cmd}\" should not be hidden.");
+				$line->explain_warning(
+"Hidden shell commands do not appear on the terminal or in the log file",
+"when they are executed. When they fail, the error message cannot be",
+"assigned to the command, which is very difficult to debug.");
+			}
+		}
+
+		if ($hidden =~ m"-") {
+			$line->log_warning("The use of a leading \"-\" to suppress errors is deprecated.");
+			$line->explain_warning(
+"If you really want to ignore any errors from this command (including",
+"all errors you never thought of), append \"|| \${TRUE}\" to the",
+"command.");
+		}
+
+		if ($macro eq "\${RUN}") {
+			$set_e_mode = true;
+		}
+	}
+
+	$state = SCST_START;
+	while ($rest =~ s/^$regex_shellword//) {
+		my ($shellword) = ($1);
+
+		$opt_debug_shell and $line->log_debug(scst_statename->[$state] . ": ${shellword}");
+
+		checkline_mk_shellword($line, $shellword, !(
+		       $state == SCST_CASE
+		    || $state == SCST_FOR_CONT
+		    || $state == SCST_SET_CONT
+		    || ($state == SCST_START && $shellword =~ regex_sh_varassign)));
+
+		#
+		# Actions associated with the current state
+		# and the symbol on the "input tape".
+		#
+
+		if ($state == SCST_START || $state == SCST_COND) {
+			my ($type);
+
+			if ($shellword eq "\${RUN}") {
+				# Just skip this one.
+
+			} elsif (exists(forbidden_commands->{basename($shellword)})) {
+				$line->log_error("${shellword} must not be used in Makefiles.");
+				$line->explain_error(
+"This command must appear in INSTALL scripts, not in the package",
+"Makefile, so that the package also works if it is installed as a binary",
+"package via pkg_add.");
+
+			} elsif (exists(get_tool_names()->{$shellword})) {
+				if (!exists($mkctx_tools->{$shellword}) && !exists($mkctx_tools->{"g$shellword"})) {
+					$line->log_warning("The \"${shellword}\" tool is used but not added to USE_TOOLS.");
+				}
+
+				if (exists(get_required_vartools()->{$shellword})) {
+					$line->log_warning("Please use \"\${" . get_vartool_names()->{$shellword} . "}\" instead of \"${shellword}\".");
+				}
+
+				checkline_mk_shellcmd_use($line, $shellword);
+
+			} elsif ($shellword =~ m"^\$\{([\w_]+)\}$" && exists(get_varname_to_toolname()->{$1})) {
+				my ($vartool) = ($1);
+				my $plain_tool = get_varname_to_toolname()->{$vartool};
+
+				if (!exists($mkctx_tools->{$plain_tool})) {
+					$line->log_warning("The \"${plain_tool}\" tool is used but not added to USE_TOOLS.");
+				}
+
+				# Deactivated to allow package developers to write
+				# consistent code that uses ${TOOL} in all places.
+				if (false && defined($mkctx_target) && $mkctx_target =~ m"^(?:pre|do|post)-(?:extract|patch|wrapper|configure|build|install|package|clean)$") {
+					if (!exists(get_required_vartool_varnames()->{$vartool})) {
+						$opt_warn_extra and $line->log_note("You can write \"${plain_tool}\" instead of \"${shellword}\".");
+						$opt_warn_extra and $line->explain_note(
+"The wrapper framework from pkgsrc takes care that a sufficiently",
+"capable implementation of that tool will be selected.",
+"",
+"Calling the commands by their plain name instead of the macros is",
+"only available in the {pre,do,post}-* targets. For all other targets,",
+"you should still use the macros.");
+					}
+				}
+
+				checkline_mk_shellcmd_use($line, $shellword);
+
+			} elsif ($shellword =~ m"^\$\{([\w_]+)\}$" && defined($type = get_variable_type($line, $1)) && $type->basic_type eq "ShellCommand") {
+				checkline_mk_shellcmd_use($line, $shellword);
+
+			} elsif ($shellword =~ m"^\$\{(\w+)\}$" && defined($pkgctx_vardef) && exists($pkgctx_vardef->{$1})) {
+				# When the package author has explicitly
+				# defined a command variable, assume it
+				# to be valid.
+
+			} elsif ($shellword =~ m"^(?:\(|\)|:|;|;;|&&|\|\||\{|\}|break|case|cd|continue|do|done|elif|else|esac|eval|exec|exit|export|fi|for|if|read|set|shift|then|umask|unset|while)$") {
+				# Shell builtins are fine.
+
+			} elsif ($shellword =~ m"^[\w_]+=.*$") {
+				# Variable assignment.
+
+			} elsif ($shellword =~ m"^\./.*$") {
+				# All commands from the current directory are fine.
+
+			} elsif ($shellword =~ m"^#") {
+				my $semicolon = ($shellword =~ m";");
+				my $multiline = ($line->lines =~ m"--");
+
+				if ($semicolon) {
+					$line->log_warning("A shell comment should not contain semicolons.");
+				}
+				if ($multiline) {
+					$line->log_warning("A shell comment does not stop at the end of line.");
+				}
+
+				if ($semicolon || $multiline) {
+					$line->explain_warning(
+"When you split a shell command into multiple lines that are continued",
+"with a backslash, they will nevertheless be converted to a single line",
+"before the shell sees them. That means that even if it _looks_ like that",
+"the comment only spans one line in the Makefile, in fact it spans until",
+"the end of the whole shell command. To insert a comment into shell code,",
+"you can pass it as an argument to the \${SHCOMMENT} macro, which expands",
+"to a command doing nothing. Note that any special characters are",
+"nevertheless interpreted by the shell.");
+				}
+
+			} else {
+				$opt_warn_extra and $line->log_warning("Unknown shell command \"${shellword}\".");
+				$opt_warn_extra and $line->explain_warning(
+"If you want your package to be portable to all platforms that pkgsrc",
+"supports, you should only use shell commands that are covered by the",
+"tools framework.");
+
+			}
+		}
+
+		if ($state == SCST_COND && $shellword eq "cd") {
+			$line->log_error("The Solaris /bin/sh cannot handle \"cd\" inside conditionals.");
+			$line->explain_error(
+"When the Solaris shell is in \"set -e\" mode and \"cd\" fails, the",
+"shell will exit, no matter if it is protected by an \"if\" or the",
+"\"||\" operator.");
+		}
+
+		if (($state != SCST_PAX_S && $state != SCST_SED_E && $state != SCST_CASE_LABEL)) {
+			checkline_mk_absolute_pathname($line, $shellword);
+		}
+
+		if (($state == SCST_INSTALL_D || $state == SCST_MKDIR) && $shellword =~ m"^(?:\$\{DESTDIR\})?\$\{PREFIX(?:|:Q)\}/") {
+			$line->log_warning("Please use AUTO_MKDIRS instead of "
+				. (($state == SCST_MKDIR) ? "\${MKDIR}" : "\${INSTALL} -d")
+				. ".");
+			$line->explain_warning(
+"Setting AUTO_MKDIRS=yes automatically creates all directories that are",
+"mentioned in the PLIST. If you need additional directories, specify",
+"them in INSTALLATION_DIRS, which is a list of directories relative to",
+"\${PREFIX}.");
+		}
+
+		if (($state == SCST_INSTALL_DIR || $state == SCST_INSTALL_DIR2) && $shellword !~ regex_mk_shellvaruse && $shellword =~ m"^(?:\$\{DESTDIR\})?\$\{PREFIX(?:|:Q)\}/(.*)") {
+			my ($dirname) = ($1);
+
+			$line->log_note("You can use AUTO_MKDIRS=yes or INSTALLATION_DIRS+= ${dirname} instead of this command.");
+			$line->explain_note(
+"This saves you some typing. You also don't have to think about which of",
+"the many INSTALL_*_DIR macros is appropriate, since INSTALLATION_DIRS",
+"takes care of that.",
+"",
+"Note that you should only do this if the package creates _all_",
+"directories it needs before trying to install files into them.",
+"",
+"Many packages include a list of all needed directories in their PLIST",
+"file. In that case, you can just set AUTO_MKDIRS=yes and be done.");
+		}
+
+		if ($state == SCST_INSTALL_DIR2 && $shellword =~ m"^\$") {
+			$line->log_warning("The INSTALL_*_DIR commands can only handle one directory at a time.");
+			$line->explain_warning(
+"Many implementations of install(1) can handle more, but pkgsrc aims at",
+"maximum portability.");
+		}
+
+		if ($state == SCST_PAX && $shellword eq "-pe") {
+			$line->log_warning("Please use the -pp option to pax(1) instead of -pe.");
+			$line->explain_warning(
+"The -pe option tells pax to preserve the ownership of the files, which",
+"means that the installed files will belong to the user that has built",
+"the package. That's a Bad Thing.");
+		}
+
+		if ($state == SCST_PAX_S || $state == SCST_SED_E) {
+			if (false && $shellword !~ m"^[\"\'].*[\"\']$") {
+				$line->log_warning("Substitution commands like \"${shellword}\" should always be quoted.");
+				$line->explain_warning(
+"Usually these substitution commands contain characters like '*' or",
+"other shell metacharacters that might lead to lookup of matching",
+"filenames and then expand to more than one word.");
+			}
+		}
+
+		if ($state == SCST_ECHO && $shellword eq "-n") {
+			$line->log_warning("Please use \${ECHO_N} instead of \"echo -n\".");
+		}
+
+		if ($opt_warn_extra && $state != SCST_CASE_LABEL_CONT && $shellword eq "|") {
+			$line->log_warning("The exitcode of the left-hand-side command of the pipe operator is ignored.");
+			$line->explain_warning(
+"If you need to detect the failure of the left-hand-side command, use",
+"temporary files to save the output of the command.");
+		}
+
+		if ($opt_warn_extra && $shellword eq ";" && $state != SCST_COND_CONT && $state != SCST_FOR_CONT && !$set_e_mode) {
+			$line->log_warning("Please switch to \"set -e\" mode before using a semicolon to separate commands.");
+			$line->explain_warning(
+"Older versions of the NetBSD make(1) had run the shell commands using",
+"the \"-e\" option of /bin/sh. In 2004, this behavior has been changed to",
+"follow the POSIX conventions, which is to not use the \"-e\" option.",
+"The consequence of this change is that shell programs don't terminate",
+"as soon as an error occurs, but try to continue with the next command.",
+"Imagine what would happen for these commands:",
+"    cd \"\$HOME\"; cd /nonexistent; rm -rf *",
+"To fix this warning, either insert \"set -e\" at the beginning of this",
+"line or use the \"&&\" operator instead of the semicolon.");
+		}
+
+		#
+		# State transition.
+		#
+
+		if ($state == SCST_SET && $shellword =~ m"^-.*e") {
+			$set_e_mode = true;
+		}
+		if ($state == SCST_START && $shellword eq "\${RUN}") {
+			$set_e_mode = true;
+		}
+
+		$state =  ($shellword eq ";;") ? SCST_CASE_LABEL
+			# Note: The order of the following two lines is important.
+			: ($state == SCST_CASE_LABEL_CONT && $shellword eq "|") ? SCST_CASE_LABEL
+			: ($shellword =~ m"^[;&\|]+$") ? SCST_START
+			: ($state == SCST_START) ? (
+				  ($shellword eq "\${INSTALL}") ? SCST_INSTALL
+				: ($shellword eq "\${MKDIR}") ? SCST_MKDIR
+				: ($shellword eq "\${PAX}") ? SCST_PAX
+				: ($shellword eq "\${SED}") ? SCST_SED
+				: ($shellword eq "\${ECHO}") ? SCST_ECHO
+				: ($shellword eq "\${RUN}") ? SCST_START
+				: ($shellword eq "echo") ? SCST_ECHO
+				: ($shellword eq "set") ? SCST_SET
+				: ($shellword =~ m"^(?:if|elif|while)$") ? SCST_COND
+				: ($shellword =~ m"^(?:then|else|do)$") ? SCST_START
+				: ($shellword eq "case") ? SCST_CASE
+				: ($shellword eq "for") ? SCST_FOR
+				: ($shellword eq "(") ? SCST_START
+				: ($shellword =~ m"^\$\{INSTALL_[A-Z]+_DIR\}$") ? SCST_INSTALL_DIR
+				: ($shellword =~ regex_sh_varassign) ? SCST_START
+				: SCST_CONT)
+			: ($state == SCST_MKDIR) ? SCST_MKDIR
+			: ($state == SCST_INSTALL && $shellword eq "-d") ? SCST_INSTALL_D
+			: ($state == SCST_INSTALL || $state == SCST_INSTALL_D) ? (
+				  ($shellword =~ m"^-[ogm]$") ? SCST_CONT
+				: $state)
+			: ($state == SCST_INSTALL_DIR) ? (
+				  ($shellword =~ m"^-") ? SCST_CONT
+				: ($shellword =~ m"^\$") ? SCST_INSTALL_DIR2
+				: $state)
+			: ($state == SCST_INSTALL_DIR2) ? $state
+			: ($state == SCST_PAX) ? (
+				  ($shellword eq "-s") ? SCST_PAX_S
+				: ($shellword =~ m"^-") ? SCST_PAX
+				: SCST_CONT)
+			: ($state == SCST_PAX_S) ? SCST_PAX
+			: ($state == SCST_SED) ? (
+				  ($shellword eq "-e") ? SCST_SED_E
+				: ($shellword =~ m"^-") ? SCST_SED
+				: SCST_CONT)
+			: ($state == SCST_SED_E) ? SCST_SED
+			: ($state == SCST_SET) ? SCST_SET_CONT
+			: ($state == SCST_SET_CONT) ? SCST_SET_CONT
+			: ($state == SCST_CASE) ? SCST_CASE_IN
+			: ($state == SCST_CASE_IN && $shellword eq "in") ? SCST_CASE_LABEL
+			: ($state == SCST_CASE_LABEL && $shellword eq "esac") ? SCST_CONT
+			: ($state == SCST_CASE_LABEL) ? SCST_CASE_LABEL_CONT
+			: ($state == SCST_CASE_LABEL_CONT && $shellword eq ")") ? SCST_START
+			: ($state == SCST_CONT) ? SCST_CONT
+			: ($state == SCST_COND) ? SCST_COND_CONT
+			: ($state == SCST_COND_CONT) ? SCST_COND_CONT
+			: ($state == SCST_FOR) ? SCST_FOR_IN
+			: ($state == SCST_FOR_IN && $shellword eq "in") ? SCST_FOR_CONT
+			: ($state == SCST_FOR_CONT) ? SCST_FOR_CONT
+			: ($state == SCST_ECHO) ? SCST_CONT
+			: do {
+				$line->log_warning("[" . scst_statename->[$state] . " ${shellword}] Keeping the current state.");
+				$state;
+			};
+	}
+
+	if ($rest !~ m"^\s*$") {
+		$line->log_error("Internal pkglint error: " . scst_statename->[$state] . ": rest=${rest}");
+	}
+}
+
+sub checkline_mk_shellcmd($$) {
+	my ($line, $shellcmd) = @_;
+
+	checkline_mk_text($line, $shellcmd);
+	checkline_mk_shelltext($line, $shellcmd);
+}
+
diff --git a/pkgtools/pkglint4/files/PkgLint/SimpleMatch.pm b/pkgtools/pkglint4/files/PkgLint/SimpleMatch.pm
new file mode 100644
index 00000000000..a4934372758
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/SimpleMatch.pm
@@ -0,0 +1,44 @@
+# $NetBSD: SimpleMatch.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# A SimpleMatch is the result of applying a regular expression to a Perl
+# scalar value. It can return the range and the text of the captured
+# groups.
+#
+package PkgLint::SimpleMatch;
+
+use strict;
+use warnings;
+
+use enum qw(STRING STARTS ENDS N);
+
+sub new($$) {
+	my ($class, $string, $starts, $ends) = @_;
+	my ($self) = ([$string, [@{$starts}], [@{$ends}], $#{$ends}]);
+	bless($self, $class);
+	return $self;
+}
+
+sub string($)		{ return shift()->[STRING]; }
+sub n($)		{ return shift()->[N]; }
+
+sub has($$) {
+	my ($self, $n) = @_;
+
+	return 0 <= $n && $n <= $self->n
+	    && defined($self->[STARTS]->[$n])
+	    && defined($self->[ENDS]->[$n]);
+}
+
+sub text($$) {
+	my ($self, $n) = @_;
+
+	my $start = $self->[STARTS]->[$n];
+	my $end = $self->[ENDS]->[$n];
+	return substr($self->string, $start, $end - $start);
+}
+
+sub range($$) {
+	my ($self, $n) = @_;
+
+	return ($self->[STARTS]->[$n], $self->[ENDS]->[$n]);
+}
diff --git a/pkgtools/pkglint4/files/PkgLint/SubstContext.pm b/pkgtools/pkglint4/files/PkgLint/SubstContext.pm
new file mode 100644
index 00000000000..f21e57546d0
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/SubstContext.pm
@@ -0,0 +1,198 @@
+# $NetBSD: SubstContext.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# This class records the state of a block of variable assignments that make
+# up a SUBST class. As these variable assignments are not easy to get right
+# unless you do it every day, and the possibility of typos is high, pkglint
+# provides additional checks for them.
+#
+package PkgLint::SubstContext;
+
+use strict;
+use warnings;
+
+BEGIN {
+	import PkgLint::Util qw(
+		false true
+	);
+	import PkgLint::Logging qw(
+		log_warning
+	);
+}
+
+use enum qw(:SUBST_ ID CLASS STAGE MESSAGE FILES SED VARS FILTER_CMD);
+
+sub new($) {
+	my ($class) = @_;
+	my ($self) = ([undef, undef, undef, undef, [], [], [], undef]);
+	bless($self, $class);
+	return $self;
+}
+
+sub subst_class($)		{ return shift()->[SUBST_CLASS]; }
+sub subst_stage($)		{ return shift()->[SUBST_STAGE]; }
+sub subst_message($)		{ return shift()->[SUBST_MESSAGE]; }
+sub subst_files($)		{ return shift()->[SUBST_FILES]; }
+sub subst_sed($)		{ return shift()->[SUBST_SED]; }
+sub subst_vars($)		{ return shift()->[SUBST_VARS]; }
+sub subst_filter_cmd($)		{ return shift()->[SUBST_FILTER_CMD]; }
+sub subst_id($)			{ return shift()->[SUBST_ID]; }
+
+sub init($) {
+	my ($self) = @_;
+
+	$self->[SUBST_ID] = undef;
+	$self->[SUBST_CLASS] = undef;
+	$self->[SUBST_STAGE] = undef;
+	$self->[SUBST_MESSAGE] = undef;
+	$self->[SUBST_FILES] = [];
+	$self->[SUBST_SED] = [];
+	$self->[SUBST_VARS] = [];
+	$self->[SUBST_FILTER_CMD] = undef;
+}
+
+sub check_end($$) {
+	my ($self, $line) = @_;
+
+	return unless defined($self->subst_id);
+
+	if (!defined($self->subst_class)) {
+		$main::opt_warn_extra and $line->log_warning("Incomplete SUBST block: SUBST_CLASSES missing.");
+	}
+	if (!defined($self->subst_stage)) {
+		$main::opt_warn_extra and $line->log_warning("Incomplete SUBST block: SUBST_STAGE missing.");
+	}
+	if (@{$self->subst_files} == 0) {
+		$main::opt_warn_extra and $line->log_warning("Incomplete SUBST block: SUBST_FILES missing.");
+	}
+	if (@{$self->subst_sed} == 0 && @{$self->subst_vars} == 0 && !defined($self->subst_filter_cmd)) {
+		$main::opt_warn_extra and $line->log_warning("Incomplete SUBST block: SUBST_SED or SUBST_VARS missing.");
+	}
+	$self->init();
+}
+
+sub is_complete($) {
+	my ($self) = @_;
+
+	return false unless defined($self->subst_id);
+	return false unless defined($self->subst_class);
+	return false unless defined($self->subst_files);
+	return false if @{$self->subst_sed} == 0 && @{$self->subst_vars} == 0;
+	return true;
+}
+
+sub check_varassign($$$$$) {
+	my ($self, $line, $varname, $op, $value) = @_;
+	my ($varbase, $varparam, $id);
+
+	if ($varname eq "SUBST_CLASSES") {
+
+		if ($value =~ m"^(\S+)\s") {
+			$main::opt_warn_extra and $line->log_warning("Please add only one class at a time to SUBST_CLASSES.");
+			$self->[SUBST_CLASS] = $1;
+			$self->[SUBST_ID] = $1;
+
+		} else {
+			if (defined($self->subst_class)) {
+				$main::opt_warn_extra and $line->log_warning("SUBST_CLASSES should only appear once in a SUBST block.");
+			}
+			$self->[SUBST_CLASS] = $value;
+			$self->[SUBST_ID] = $value;
+		}
+		return;
+	}
+
+	$id = $self->subst_id;
+
+	if ($varname =~ m"^(SUBST_(?:STAGE|MESSAGE|FILES|SED|VARS|FILTER_CMD))\.([\-\w_]+)$") {
+		($varbase, $varparam) = ($1, $2);
+
+		if (!defined($id)) {
+			$main::opt_warn_extra and $line->log_note("SUBST_CLASSES should precede the definition of ${varbase}.${varparam}.");
+
+			$id = $self->[SUBST_ID] = $varparam;
+		}
+	} else {
+		if (defined($id)) {
+			$main::opt_warn_extra and $line->log_warning("Foreign variable in SUBST block.");
+		}
+		return;
+	}
+
+	if ($varparam ne $id) {
+
+		# XXX: This code sometimes produces weird warnings. See
+		# meta-pkgs/xorg/Makefile.common 1.41 for an example.
+		if ($self->is_complete()) {
+			$self->check_end($line);
+
+			# The following assignment prevents an additional warning,
+			# but from a technically viewpoint, it is incorrect.
+			$self->[SUBST_CLASS] = $varparam;
+			$self->[SUBST_ID] = $varparam;
+			$id = $varparam;
+		} else {
+			$main::opt_warn_extra and $line->log_warning("Variable parameter \"${varparam}\" does not match SUBST class \"${id}\".");
+		}
+	}
+
+	if ($varbase eq "SUBST_STAGE") {
+		if (defined($self->subst_stage)) {
+			$main::opt_warn_extra and $line->log_warning("Duplicate definition of SUBST_STAGE.${id}.");
+		} else {
+			$self->[SUBST_STAGE] = $value;
+		}
+
+	} elsif ($varbase eq "SUBST_MESSAGE") {
+		if (defined($self->subst_message)) {
+			$main::opt_warn_extra and $line->log_warning("Duplicate definition of SUBST_MESSAGE.${id}.");
+		} else {
+			$self->[SUBST_MESSAGE] = $value;
+		}
+
+	} elsif ($varbase eq "SUBST_FILES") {
+		if (@{$self->subst_files} > 0) {
+			if ($op ne "+=") {
+				$main::opt_warn_extra and $line->log_warning("All but the first SUBST_FILES line should use the \"+=\" operator.");
+			}
+		}
+		push(@{$self->subst_files}, $value);
+
+	} elsif ($varbase eq "SUBST_SED") {
+		if (@{$self->subst_sed} > 0) {
+			if ($op ne "+=") {
+				$main::opt_warn_extra and $line->log_warning("All but the first SUBST_SED line should use the \"+=\" operator.");
+			}
+		}
+		push(@{$self->subst_sed}, $value);
+
+	} elsif ($varbase eq "SUBST_FILTER_CMD") {
+		if (defined($self->subst_filter_cmd)) {
+			$main::opt_warn_extra and $line->log_warning("Duplicate definition of SUBST_FILTER_CMD.${id}.");
+		} else {
+			$self->[SUBST_FILTER_CMD] = $value;
+		}
+
+	} elsif ($varbase eq "SUBST_VARS") {
+		if (@{$self->subst_vars} > 0) {
+			if ($op ne "+=") {
+				$main::opt_warn_extra and $line->log_warning("All but the first SUBST_VARS line should use the \"+=\" operator.");
+			}
+		}
+		push(@{$self->subst_vars}, $value);
+
+	} else {
+		$main::opt_warn_extra and $line->log_warning("Foreign variable in SUBST block.");
+	}
+}
+
+sub to_string($) {
+	my ($self) = @_;
+
+	return sprintf("SubstContext(%s %s %s %s %s %s)",
+	    (defined($self->subst_class) ? $self->subst_class : "(undef)"),
+	    (defined($self->subst_stage) ? $self->subst_stage : "(undef)"),
+	    (defined($self->subst_message) ? $self->subst_message : "(undef)"),
+	    scalar(@{$self->subst_files}),
+	    scalar(@{$self->subst_sed}),
+	    (defined($self->subst_id) ? $self->subst_id : "(undef)"));
+}
diff --git a/pkgtools/pkglint4/files/PkgLint/Type.pm b/pkgtools/pkglint4/files/PkgLint/Type.pm
new file mode 100644
index 00000000000..1eb7cd2a74c
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/Type.pm
@@ -0,0 +1,102 @@
+# $NetBSD: Type.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# A Type in pkglint is a combination of a data type and a permission
+# specification. Further details can be found in the chapter ``The pkglint
+# type system'' of the pkglint book.
+#
+package PkgLint::Type;
+
+use strict;
+use warnings;
+
+BEGIN {
+	import PkgLint::Util qw(
+		false true
+	);
+	import PkgLint::Logging qw(
+		log_warning NO_LINES
+	);
+	use Exporter;
+	use vars qw(@ISA @EXPORT_OK);
+	@ISA = qw(Exporter);
+	@EXPORT_OK = qw(
+		LK_NONE LK_INTERNAL LK_EXTERNAL
+		GUESSED NOT_GUESSED
+	);
+}
+
+use enum qw(KIND_OF_LIST BASIC_TYPE ACLS IS_GUESSED);
+use enum qw(:LK_ NONE INTERNAL EXTERNAL);
+use enum qw(:ACLE_ SUBJECT_RE PERMS);
+use enum qw(NOT_GUESSED GUESSED);
+
+sub new($$$) {
+	my ($class, $kind_of_list, $basic_type, $acls, $guessed) = @_;
+	my ($self) = ([$kind_of_list, $basic_type, $acls, $guessed]);
+	bless($self, $class);
+	return $self;
+}
+
+sub kind_of_list($)	{ return shift()->[KIND_OF_LIST]; }
+sub basic_type($)	{ return shift()->[BASIC_TYPE]; }
+# no getter method for acls
+sub is_guessed($)	{ return shift()->[IS_GUESSED]; }
+
+sub perms($$) {
+	my ($self, $fname) = @_;
+	my ($perms);
+
+	foreach my $acl_entry (@{$self->[ACLS]}) {
+		if ($fname =~ $acl_entry->[ACLE_SUBJECT_RE]) {
+			return $acl_entry->[ACLE_PERMS];
+		}
+	}
+	return;
+}
+
+# Returns the union of all possible permissions. This can be used to
+# check whether a variable may be defined or used at all, or if it is
+# read-only.
+sub perms_union($) {
+	my ($self) = @_;
+	my ($perms);
+
+	$perms = "";
+	foreach my $acl_entry(@{$self->[ACLS]}) {
+		$perms .= $acl_entry->[ACLE_PERMS];
+	}
+	return $perms;
+}
+
+# Returns whether the type is considered an external list. All external
+# lists are, of course, as well as some other data types that are not
+# defined as lists to make the implementation of checkline_mk_vartype
+# easier.
+sub is_practically_a_list($) {
+	my ($self) = @_;
+
+	return ($self->kind_of_list == LK_EXTERNAL) ? true
+	    : ($self->kind_of_list == LK_INTERNAL) ? false
+	    : ($self->basic_type eq "BuildlinkPackages") ? true
+	    : ($self->basic_type eq "SedCommands") ? true
+	    : ($self->basic_type eq "ShellCommand") ? true
+	    : false;
+}
+
+# Returns whether variables of this type may be extended using the "+="
+# operator.
+sub may_use_plus_eq($) {
+	my ($self) = @_;
+
+	return ($self->kind_of_list != LK_NONE) ? true
+	    : ($self->basic_type eq "AwkCommand") ? true
+	    : ($self->basic_type eq "BuildlinkPackages") ? true
+	    : ($self->basic_type eq "SedCommands") ? true
+	    : false;
+}
+
+sub to_string($) {
+	my ($self) = @_;
+
+	return (["", "InternalList of ", "List of "]->[$self->kind_of_list]) . $self->basic_type;
+}
diff --git a/pkgtools/pkglint4/files/PkgLint/Util.pm b/pkgtools/pkglint4/files/PkgLint/Util.pm
new file mode 100644
index 00000000000..350f96f6b65
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/Util.pm
@@ -0,0 +1,97 @@
+# $NetBSD: Util.pm,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# This package is a catch-all for subroutines that are not application-spe-
+# cific. Currently it contains the boolean constants C<false> and C<true>,
+# as well as a function to print text in a table format, and a function
+# that converts an array into a hash. The latter is just for convenience
+# because I don't know of a Perl operator similar to qw() that can be used
+# for creating a hash.
+#
+package PkgLint::Util;
+
+use strict;
+use warnings;
+
+BEGIN {
+	use Exporter;
+	use vars qw(@ISA @EXPORT_OK);
+	@ISA = qw(Exporter);
+	@EXPORT_OK = qw(
+		assert
+		false true dont_know doesnt_matter
+		array_to_hash normalize_pathname print_table
+	);
+}
+
+use enum qw(false true dont_know doesnt_matter);
+
+sub assert($$) {
+	my ($cond, $msg) = @_;
+	my (@callers, $n);
+
+	if (!$cond) {
+		print STDERR ("FATAL: Assertion failed: ${msg}.\n");
+
+		for ($n = 0; my @info = caller($n); $n++) {
+			push(@callers, [$info[2], $info[3]]);
+		}
+
+		for (my $i = $#callers; $i >= 0; $i--) {
+			my $info = $callers[$i];
+			printf STDERR ("  line %4d called %s\n", $info->[0], $info->[1]);
+		}
+		exit(1);
+	}
+}
+
+# Prints the C<$table> on the C<$out> stream. The C<$table> shall be an
+# array of rows, each row shall be an array of cells, and each cell shall
+# be a string.
+sub print_table($$) {
+	my ($out, $table) = @_;
+	my (@width) = ();
+	foreach my $row (@{$table}) {
+		foreach my $i (0..$#{$row}) {
+			if (!defined($width[$i]) || length($row->[$i]) > $width[$i]) {
+				$width[$i] = length($row->[$i]);
+			}
+		}
+	}
+	foreach my $row (@{$table}) {
+		my ($max) = ($#{$row});
+		foreach my $i (0..$max) {
+			if ($i != 0) {
+				print $out ("  ");
+			}
+			print $out ($row->[$i]);
+			if ($i != $max) {
+				print $out (" " x ($width[$i] - length($row->[$i])));
+			}
+		}
+		print $out ("\n");
+	}
+}
+
+sub array_to_hash(@) {
+	my ($result) = {};
+
+	foreach my $arg (@_) {
+		$result->{$arg} = 1;
+	}
+	return $result;
+}
+
+sub normalize_pathname($) {
+	my ($fname) = @_;
+
+	# strip "." path components
+	$fname =~ s,^(?:\./)+,,;
+	$fname =~ s,/(?:\./)+,/,g;
+	$fname =~ s,/+,/,g;
+
+	# strip intermediate "../.." path components
+	while ($fname =~ s,/[^.][^/]*/[^.][^/]*/\.\./\.\./,/,) {
+	}
+
+	return $fname;
+}
diff --git a/pkgtools/pkglint4/files/PkgLint/VarUseContext.pm b/pkgtools/pkglint4/files/PkgLint/VarUseContext.pm
new file mode 100644
index 00000000000..8311624340b
--- /dev/null
+++ b/pkgtools/pkglint4/files/PkgLint/VarUseContext.pm
@@ -0,0 +1,67 @@
+# The various contexts in which make(1) variables can appear in pkgsrc.
+# Further details can be found in the chapter ``The pkglint type system''
+# of the pkglint book.
+#
+package PkgLint::VarUseContext;
+
+use strict;
+use warnings;
+
+BEGIN {
+	import PkgLint::Util qw(
+		false true
+	);
+	import PkgLint::Logging qw(
+		log_warning NO_LINES
+	);
+	use Exporter;
+	use vars qw(@ISA @EXPORT_OK);
+	@ISA = qw(Exporter);
+	@EXPORT_OK = qw(
+		VUC_TIME_UNKNOWN VUC_TIME_LOAD VUC_TIME_RUN
+		VUC_TYPE_UNKNOWN
+		VUC_SHELLWORD_UNKNOWN VUC_SHELLWORD_PLAIN VUC_SHELLWORD_DQUOT
+		  VUC_SHELLWORD_SQUOT VUC_SHELLWORD_BACKT VUC_SHELLWORD_FOR
+		VUC_EXTENT_UNKNOWN VUC_EXTENT_FULL VUC_EXTENT_WORD
+		  VUC_EXTENT_WORD_PART
+	);
+}
+
+use enum qw(TIME TYPE SHELLWORD EXTENT);
+use enum qw(:VUC_TIME_ UNKNOWN LOAD RUN);
+use constant VUC_TYPE_UNKNOWN => undef;
+use enum qw(:VUC_SHELLWORD_ UNKNOWN PLAIN DQUOT SQUOT BACKT FOR);
+use enum qw(:VUC_EXTENT_ UNKNOWN FULL WORD WORD_PART);
+
+my $pool = {};
+
+sub new($$$$$) {
+	my ($class, $time, $type, $shellword, $extent) = @_;
+	my ($self) = ([$time, $type, $shellword, $extent]);
+	bless($self, $class);
+	return $self;
+}
+sub new_from_pool($$$$$) {
+	my ($class, $time, $type, $shellword, $extent) = @_;
+	my $key = "${time}-${type}-${shellword}-${extent}";
+
+	if (!exists($pool->{$key})) {
+		$pool->{$key} = $class->new($time, $type, $shellword, $extent);
+	}
+	return $pool->{$key};
+}
+
+sub time($)		{ return shift()->[TIME]; }
+sub type($)		{ return shift()->[TYPE]; }
+sub shellword($)	{ return shift()->[SHELLWORD]; }
+sub extent($)		{ return shift()->[EXTENT]; }
+
+sub to_string($) {
+	my ($self) = @_;
+
+	return sprintf("(%s %s %s %s)",
+	    ["unknown-time", "load-time", "run-time"]->[$self->time],
+	    (defined($self->type) ? $self->type->to_string() : "no-type"),
+	    ["none", "plain", "squot", "dquot", "backt", "for"]->[$self->shellword],
+	    ["unknown", "full", "word", "word-part"]->[$self->extent]);
+}
diff --git a/pkgtools/pkglint4/files/build.pl b/pkgtools/pkglint4/files/build.pl
new file mode 100644
index 00000000000..e58b4e90ae4
--- /dev/null
+++ b/pkgtools/pkglint4/files/build.pl
@@ -0,0 +1,25 @@
+#! @PERL@
+# $NetBSD: build.pl,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+
+use strict;
+use warnings;
+
+sub readfile {
+	my $file = shift;
+
+	local $/ = undef;
+	open(my $in, "<", $file) || die "failed to read $file: $!";
+	my $contents = <$in>;
+	close($in) || die "failed to read $file: $!";
+
+	return $contents;
+}
+
+while (my $line = <>) {
+	if ($line =~ m"^#include (.+)$/") {
+		print readfile($1);
+	} else {
+		print $line;
+	}
+}
diff --git a/pkgtools/pkglint4/files/deprecated.map b/pkgtools/pkglint4/files/deprecated.map
new file mode 100644
index 00000000000..f8b25c4d16c
--- /dev/null
+++ b/pkgtools/pkglint4/files/deprecated.map
@@ -0,0 +1,166 @@
+# $NetBSD: deprecated.map,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+
+# This file contains names of Makefile variables and a short explanation
+# what to do to make the warning disappear. Lines should only be removed
+# if the explanation changes, in which case the new explanation should
+# be added to the current date.
+
+# December 2003
+FIX_RPATH		It has been removed from pkgsrc in 2003.
+
+# February 2005
+ALL_TARGET		Use BUILD_TARGET instead.
+NO_WRKSUBDIR		Use WRKSRC=${WRKDIR} instead.
+LIB_DEPENDS		Use DEPENDS instead.
+MASTER_SITE_SUBDIR	Use ${MASTER_SITE_FOO:=subdir/} instead.
+PATCH_SITE_SUBDIR	Use ${PATCH_SITES_FOO:=subdir/} instead.
+ONLY_FOR_ARCHS		Use ONLY_FOR_PLATFORM instead.
+NOT_FOR_ARCHS		Use NOT_FOR_PLATFORM instead.
+ONLY_FOR_OPSYS		Use ONLY_FOR_PLATFORM instead.
+NOT_FOR_OPSYS		Use NOT_FOR_PLATFORM instead.
+
+# May 2005
+ALL_TARGET		Use BUILD_TARGET instead.
+DIGEST_FILE		Use DISTINFO_FILE instead.
+IGNORE			Use PKG_FAIL_REASON or PKG_SKIP_REASON instead.
+IS_INTERACTIVE		Use INTERACTIVE_STAGE instead.
+KERBEROS		Use the PKG_OPTIONS framework instead.
+MASTER_SITE_SUBDIR	Use some form of MASTER_SITES instead.
+MD5_FILE		Use DISTINFO_FILE instead.
+MIRROR_DISTFILE		Use NO_BIN_ON_FTP and/or NO_SRC_ON_FTP instead.
+NO_CDROM		Use NO_BIN_ON_CDROM and/or NO_SRC_ON_CDROM instead.
+NO_PATCH		You can just remove it.
+NO_WRKSUBDIR		Use WRKSRC=${WRKDIR} instead.
+PATCH_SITE_SUBDIR	Use some form of PATCHES_SITES instead.
+PATCH_SUM_FILE		Use DISTINFO_FILE instead.
+PKG_JVM			Use PKG_DEFAULT_JVM instead.
+USE_BUILDLINK2		You can just remove it.
+USE_BUILDLINK3		You can just remove it.
+USE_CANNA		Use the PKG_OPTIONS framework instead.
+USE_DB4			Use the PKG_OPTIONS framework instead.
+USE_DIRS		You can just remove it.
+USE_ESOUND		Use the PKG_OPTIONS framework instead.
+USE_GIF			Use the PKG_OPTIONS framework instead.
+USE_GMAKE		Use USE_TOOLS+=gmake instead.
+USE_GNU_TOOLS		Use USE_TOOLS instead.
+USE_IDEA		Use the PKG_OPTIONS framework instead.
+USE_LIBCRACK		Use the PKG_OPTIONS framework instead.
+USE_MMX			Use the PKG_OPTIONS framework instead.
+USE_PKGLIBTOOL		Use USE_LIBTOOL instead.
+USE_SSL			Include "../../security/openssl/buildlink3.mk" instead.
+
+# July 2005
+USE_PERL5		Use USE_TOOLS+=perl or USE_TOOLS+=perl:run instead.
+
+# October 2005
+NO_TOOLS		You can just remove it.
+NO_WRAPPER		You can just remove it.
+
+# November 2005
+ALLFILES		Use CKSUMFILES instead.
+DEPENDS_TARGET		Use DEPENDS instead.
+FETCH_DEPENDS		Use DEPENDS instead.
+RUN_DEPENDS		Use DEPENDS instead.
+
+# December 2005
+USE_CUPS		Use the PKG_OPTIONS framework (option cups) instead.
+USE_I586		Use the PKG_OPTIONS framework (option i586) instead.
+USE_INN			Use the PKG_OPTIONS framework instead.
+USE_OPENLDAP		Use the PKG_OPTIONS framework (option openldap) instead.
+USE_OSS			Use the PKG_OPTIONS framework (option oss) instead.
+USE_RSAREF2		Use the PKG_OPTIONS framework (option rsaref) instead.
+USE_SASL		Use the PKG_OPTIONS framework (option sasl) instead.
+USE_SASL2		Use the PKG_OPTIONS framework (option sasl) instead.
+USE_SJ3			Use the PKG_OPTIONS framework (option sj3) instead.
+USE_SOCKS		Use the PKG_OPTIONS framework (socks4 and socks5 options) instead.
+USE_WNN4		Use the PKG_OPTIONS framework (option wnn4) instead.
+USE_XFACE		Use the PKG_OPTIONS framework instead.
+
+# February 2006
+TOOLS_DEPMETHOD		Use the :build or :run modifiers in USE_TOOLS instead.
+MANDIR			Please use ${PREFIX}/${PKGMANDIR} instead.
+DOWNLOADED_DISTFILE	Use the shell variable $$extract_file instead.
+DECOMPRESS_CMD		Use EXTRACT_CMD instead.
+
+# March 2006
+INSTALL_EXTRA_TMPL	Use INSTALL_TEMPLATE instead.
+DEINSTALL_EXTRA_TMPL	Use DEINSTALL_TEMPLATE instead.
+
+# April 2006
+RECOMMENDED		Use ABI_DEPENDS instead.
+BUILD_USES_MSGFMT	Use USE_TOOLS+=msgfmt instead.
+USE_MSGFMT_PLURALS	Use USE_TOOLS+=msgfmt instead.
+
+# May 2006
+EXTRACT_USING_PAX	Use "EXTRACT_OPTS=-t pax" instead.
+NO_EXTRACT		It doesn't exist anymore.
+_FETCH_MESSAGE		Use FETCH_MESSAGE (different format) instead.
+BUILDLINK_DEPENDS.*	Use BUILDLINK_API_DEPENDS.* instead.
+BUILDLINK_RECOMMENDED.*	Use BUILDLINK_ABI_DEPENDS.* instead.
+SHLIB_HANDLING		Use CHECK_SHLIBS_SUPPORTED instead.
+USE_RMAN		It has been removed.
+
+# June 2006
+DEINSTALL_SRC		Use the pkginstall framework instead.
+INSTALL_SRC		Use the pkginstall framework instead.
+DEINSTALL_TEMPLATE	Use DEINSTALL_TEMPLATES instead.
+INSTALL_TEMPLATE	Use INSTALL_TEMPLATES instead.
+HEADER_TEMPLATE		Use HEADER_TEMPLATES instead.
+_REPLACE.*		Use REPLACE.* instead.
+_REPLACE_FILES.*	Use REPLACE_FILES.* instead.
+MESSAGE			Use MESSAGE_SRC instead.
+INSTALL_FILE		It may only be used internally by pkgsrc.
+DEINSTALL_FILE		It may only be used internally by pkgsrc.
+
+# July 2006
+USE_DIGEST		You can just remove it.
+LTCONFIG_OVERRIDE	You can just remove it.
+USE_GNU_GETTEXT		You can just remove it.
+BUILD_ENV		Use PKGSRC_MAKE_ENV instead.
+DYNAMIC_MASTER_SITES	You can just remove it.
+
+# September 2006
+MAKEFILE		Use MAKE_FILE instead.
+
+# November 2006
+SKIP_PORTABILITY_CHECK	Use CHECK_PORTABILITY_SKIP (a list of patterns) instead.
+PKG_SKIP_REASON		Use PKG_FAIL_REASON instead.
+
+# January 2007
+BUILDLINK_TRANSFORM.*	Use BUILDLINK_FNAME_TRANSFORM.* instead.
+
+# March 2007
+SCRIPTDIR		You can just remove it.
+NO_PKG_REGISTER		You can just remove it.
+NO_DEPENDS		You can just remove it.
+
+# October 2007
+_PKG_SILENT		Use RUN (with more error checking) instead.
+_PKG_DEBUG		Use RUN (with more error checking) instead.
+LICENCE			Use LICENSE instead.
+# The following variable is not yet deprecated, as there has been
+# a large disagreement on the proper spelling.
+#ACCEPTABLE_LICENCES	Use ACCEPTABLE_LICENSES instead.
+
+# November 2007
+#USE_NCURSES		Include "../../devel/ncurses/buildlink3.mk" instead.
+
+# December 2007
+INSTALLATION_DIRS_FROM_PLIST	Use AUTO_MKDIRS instead.
+
+# April 2009
+NO_PACKAGE		It doesn't exist anymore.
+NO_MTREE		You can just remove it.
+
+# July 2012
+SETGIDGAME		Use USE_GAMESGROUP instead.
+GAMEGRP			Use GAMES_GROUP instead.
+GAMEOWN			Use GAMES_USER instead.
+
+# July 2013
+USE_GNU_READLINE	Include "../../devel/readline/buildlink3.mk" instead.
+
+# October 2014
+SVR4_PKGNAME		Just remove it.
+PKG_INSTALLATION_TYPES	Just remove it.
diff --git a/pkgtools/pkglint4/files/doc/Makefile b/pkgtools/pkglint4/files/doc/Makefile
new file mode 100644
index 00000000000..049a20531c0
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/Makefile
@@ -0,0 +1,27 @@
+# $NetBSD: Makefile,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+
+XMLDOCS+=	pkglint.xml
+XMLDOCS+=	chap.intro.xml
+XMLDOCS+=	chap.defs.xml
+XMLDOCS+=	chap.types.xml
+XMLDOCS+=	chap.code.xml
+XMLDOCS+=	chap.statemachines.xml
+XMLDOCS+=	chap.future.xml
+
+IMAGES+=	statemachine.patch.png
+IMAGES+=	statemachine.shellcmd.png
+
+.PHONY: all
+all: pkglint.html
+
+pkglint.html: ${XMLDOCS} ${IMAGES} stylesheet.xsl
+	xmlto -m stylesheet.xsl html-nochunks pkglint.xml
+
+.PHONY: clean
+clean:
+	rm -f *.html *.png
+
+.SUFFIXES: .dia .png
+.dia.png:
+	dia -e ${.TARGET:Q} -t png ${.IMPSRC:Q}
diff --git a/pkgtools/pkglint4/files/doc/chap.code.xml b/pkgtools/pkglint4/files/doc/chap.code.xml
new file mode 100644
index 00000000000..44b02f9f128
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/chap.code.xml
@@ -0,0 +1,307 @@
+<!-- $NetBSD: chap.code.xml,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+
+<chapter id="code">
+<title>Code structure</title>
+
+	<para>In this chapter, I give an overview of how the &pkglint;
+	code is organized, starting with the <function>main</function>
+	function, passing the functions that check a single line and
+	finally arriving at the infrastructure that makes writing the
+	other functions easier.</para>
+
+<sect1 id="code.overview">
+<title>Overview</title>
+
+	<para>The &pkglint; code is structured in modular, easy to
+	understand procedures. These procedures can be further
+	classified with respect to what they do. There are procedures
+	that check a file, others check the lines of a file, again
+	others check a single line. These classes of procedures are
+	described in the following sections in a top-down
+	fashion.</para>
+
+	<para>If nothing special is said about which procedures call
+	which others, you may assume that procedures of a certain rank
+	only call procedures that are of a strictly lower rank. For
+	example, no <function>checkline_*</function> will ever call
+	<function>checkfile_*</function>. Sometimes, functions of the
+	same rank are called, but these cases are documented
+	explicitly.</para>
+
+</sect1>
+
+<sect1 id="code.select">
+<title>Selecting the proper checking function</title>
+
+	<para>The <function>main</function> procedure of &pkglint; is a
+	simple loop around a TODO list containing pathnames of items (I
+	couldn't think of a better name here). The decision of which
+	checks to apply to a given item is done in
+	<function>checkitem</function>, which checks whether the item is
+	a file or a directory and dispatches the actual checking to
+	specialized procedures.</para>
+
+</sect1>
+
+<sect1 id="code.dir">
+<title>Checking a directory</title>
+
+	<para>The procedures that check a directory are
+	<function>checkdir_root</function> for the pkgsrc root
+	directory, <function>checkdir_category</function> for a category
+	of packages and <function>checkdir_package</function> for a
+	single package.</para>
+
+</sect1>
+
+<sect1 id="code.file">
+<title>Checking a file</title>
+
+	<para>Since the dispatching for files requires much code, it has
+	been put into a separate procedure called
+	<function>checkfile</function>, which further dispatches the
+	call to the other procedures.</para>
+
+	<para>The procedures that check a specific file are
+	<function>checkfile_ALTERNATIVES</function>,
+	<function>checkfile_DESCR</function>,
+	<function>checkfile_distinfo</function>,
+	<function>checkfile_extra</function>,
+	<function>checkfile_INSTALL</function>,
+	<function>checkfile_MESSAGE</function>,
+	<function>checkfile_mk</function>,
+	<function>checkfile_patch</function> and
+	<function>checkfile_PLIST</function>. For most of the
+	procedures, it should be obvious to which files they are
+	applied. A distinction is made between buildlink3 files and
+	other <filename>Makefiles</filename>, as some additional checks
+	apply to buildlink3 files. Of course, these procedures use
+	pretty much the same code for checking, and this is where the
+	<function>checklines_*</function> functions step in.</para>
+
+	<para>The <function>checkfile_package_Makefile</function>
+	function is somewhat special in that it expects four parameters
+	instead of only one. This is because loading the package data
+	has been separated from the actual checking.</para>
+
+</sect1>
+
+<sect1 id="code.lines">
+<title>Checking the lines in a file</title>
+
+	<para>This class of procedures consists of
+	<function>checklines_trailing_empty_lines</function>,
+	<function>checklines_package_Makefile_varorder</function> and
+	<function>checklines_mk</function>. The middle one is too
+	complex to be included in
+	<function>checkfile_package_Makefile</function>, and the other
+	ones are of so generic use that they deserved to be procedures
+	of their own.</para>
+
+	<para>The <function>checklines_mk</function> makes heavy use of
+	the various <function>checkline_*</function> functions that are
+	explained in the next chapter.</para>
+
+</sect1>
+
+<sect1 id="code.line">
+<title>Checking a single line in a file</title>
+
+	<para>This class of procedures checks a single line of a file.
+	The number of parameters differs for most of these procedures,
+	as some need more context information and others don't.</para>
+
+	<para>The procedures that are applicable to any file type are
+	<function>checkline_length</function>,
+	<function>checkline_valid_characters</function>,
+	<function>checkline_valid_characters_in_variable</function>,
+	<function>checkline_trailing_whitespace</function>,
+	<function>checkline_rcsid_regex</function>,
+	<function>checkline_rcsid</function>,
+	<function>checkline_relative_path</function>,
+	<function>checkline_relative_pkgdir</function>,
+	<function>checkline_spellcheck</function> and
+	<function>checkline_cpp_macro_names</function>.</para>
+
+	<para>The rest of the procedures is specific to
+	<filename>Makefile</filename>s:
+	<function>checkline_mk_text</function>,
+	<function>checkline_mk_shellword</function>,
+	<function>checkline_mk_shelltext</function>,
+	<function>checkline_mk_shellcmd</function>,
+	<function>checkline_mk_vartype_basic</function>,
+	<function>checkline_mk_vartype_basic</function>,
+	<function>checkline_mk_vartype</function> and
+	<function>checkline_mk_varassign</function>.</para>
+
+	<para>This class of procedures contains the most code in
+	&pkglint;. The procedures that check shell commands and shell
+	words both have around 200 lines, and the largest procedure is
+	the check for predefined variable types, which has almost 500
+	lines. But the code is not complex at all, since this procedure
+	contains a large switch for all the predefined types. The checks
+	for a single type usually fit on a single screen.</para>
+
+</sect1>
+
+<sect1 id="code.infrastructure">
+<title>The &pkglint; infrastructure</title>
+
+	<para>To keep the code in the checking procedures small and
+	legible, an additional layer of procedures is needed that
+	provides basic operations and abstractions for handling files as
+	a collection of lines and to print all diagnostics in a common
+	format that is suitable to further processing by software
+	tools.</para>
+
+	<para>Since October 2004, this part of &pkglint; makes use of
+	some of the object oriented features of the Perl programming
+	language. It has worked quite well upto now, but it has not been
+	fun to write object-oriented code in Perl. The most basic
+	feature I am missing is that the compiler checks whether an
+	object has a specific method or not, as I have often written
+	<code>$line->warning()</code> instead of
+	<code>$line->log_warning()</code>. This makes refacturing quite
+	difficult if you don't have a 100&nbsp;% coverage test, and I
+	don't have that.</para>
+
+	<para>The classes are all defined in the
+	<varname>PkgLint</varname> namespace.</para>
+
+	<para>The traditional class is <classname>Line</classname>,
+	which represents a logical line of a file. In case of
+	<filename>Makefile</filename>s, line continuations are parsed
+	properly and combined into a single line. For all other files,
+	each logical line corresponds to a physical line. The
+	<classname>Line</classname> class has accessor methods to its
+	fields <methodname>fname</methodname>,
+	<methodname>lines</methodname> and
+	<methodname>text</methodname>. It also has the methods
+	<methodname>log_fatal</methodname>,
+	<methodname>log_error</methodname>,
+	<methodname>log_warning</methodname>,
+	<methodname>log_info</methodname> and
+	<methodname>log_debug</methodname> that all have one parameter,
+	the diagnostics message. The other methods are used less
+	often.</para>
+
+	<para>In January 2006, the logging has been improved in
+	functionality. Before that, a logical line could well consist of
+	300 physical lines, so a diagnostic would say <quote>you have a
+	bug somewhere between line 100 and 400</quote>. This is not
+	helpful. Therefore, a new class has been invented that allows to
+	map each character of a logical line to its corresponding
+	physical location in the file. The new representation of a
+	logical line is called a <classname>String</classname>. This
+	feature is still experimental, since the only method for logging
+	a string is <methodname>log_warning</methodname>. The others are
+	still missing. It is also completely unclear how lines that have
+	been fixed by &pkglint; are represented since this moves
+	characters around in the physical lines.</para>
+
+	<para>To make pattern matching with the new
+	<classname>String</classname> easy to use, the additional class
+	<classname>StringMatch</classname> has been created. It saves
+	the result of a <classname>String</classname> that is matched
+	against a regular expression. The canonical way to get such a
+	<classname>StringMatch</classname> is to call the
+	<methodname>String::match</methodname> method.</para>
+
+	<para>Since the <classname>StringMatch</classname> was
+	convenient to use, the <classname>SimpleMatch</classname> class
+	represents the result of matching a Perl string against a
+	regular expression. The class <classname>Location</classname> is
+	currently unused.</para>
+
+</sect1>
+<sect1 id="code.style">
+<title>Perl programming style</title>
+
+	<para>The &pkglint; source code has evolved from FreeBSD's portlint,
+	which has been written in Perl, and up to now, &pkglint; is written
+	in Perl. Since one of the main ingredients to &pkglint; are regular
+	expressions, this choice seems natural, and indeed the Perl regular
+	expressions are a great help to keep the code short. But &pkglint;
+	is more than just throwing regular expressions at the package
+	files.</para>
+
+	<para>In 2004, when the &pkglint; source code comprised about
+	40&nbsp;kilobytes, this was quite appropriate. Since then, the code
+	has become much more structured and various abstraction layers have
+	been inserted. It became more and more clear that the Perl
+	programming language has not been designed with nice-looking source
+	code in mind.</para>
+
+	<para>The first example are subroutines and their parameters. In
+	most other languages, the names of the parameters are mentioned in
+	the subroutine definition. Not so in Perl. The parameters to each
+	subroutine are passed in the <literal>@_</literal> array. The usual
+	way to get named parameters is to write assign the parameter array
+	to a list of local variables. This extra statement is a nuisance,
+	but it is merely syntactical.</para>
+
+	<para>More serious is the way the arguments are passed to a
+	subroutine. Perl allows the programmer to define subroutines with a
+	weak form of prototypes, which helps to catch calls to subroutines
+	that provide a wrong number of arguments. This feature catches many
+	bugs that are easily overlooked. The downside is that anything
+	besides using scalars as parameter types is difficult to understand
+	and quickly leads to unexpected behavior. Therefore the subroutines
+	in &pkglint; only use this style for parameter passing. Oh, and by
+	the way, the subroutine prototypes are only checked for in certain
+	situations like direct calls. In method calls, nothing is checked at
+	all. Since almost all diagnostics are produced by calling
+	<code>$line->log_warning()</code> or
+	<code>$line->log_error()</code>, most of the subroutine calls in
+	&pkglint; go unchecked.</para>
+
+	<para>Instead of using magic numbers, well written code defines
+	named constants for these numbers and then refers to them using
+	their names, giving the reader extra information that plain numbers
+	could not give. Although the constant definitions look quite good in
+	&pkglint; there is one big caveat. The Perl programming language
+	does not know constants. So these definitions are rather shortcuts
+	for defining functions that return the value of the constant. And as
+	functions in Perl have package-wide scope, so have these constants.
+	This is why the namespace prefixes like <varname>SWST_</varname> are
+	necessary to avoid name clashes.</para>
+
+	<para>Most of the constants would be written as an enumeration data
+	type if Perl had one. The same limitation applies for many of the
+	classes (implemented as packages in Perl) that are simply structs.
+	The typical Perl implementation of structs are classes, er, packages
+	which then use methods for accessing the fields. Again, the names of
+	these methods are only checked at runtime, so there is no language
+	support for detecting spelling mistakes in field names.</para>
+
+	<para>Another area where Perl fails to detect many errors is the
+	loose type system. You can apply almost every operator to almost
+	every data type, and the Perl language will give you more or less
+	what you want. Especially it does not prevent you from matching
+	a regular expression against a reference. It will simply compute
+	a string representation of the reference and match the regular
+	expression against that.</para>
+
+	<para>The current Perl interpreter is very inefficient when
+	copying strings. This happens really often in pkglint, for
+	example when passing arguments to functions or saving the result
+	of a regular expression match in <quote>real</quote> variables.
+	For a great speed-up, an implementation that handles string
+	objects by reference-counting them would be better. (Lua comes
+	to mind.)</para>
+
+</sect1>
+<sect1 id="code.lang">
+<title>Switching to another language</title>
+
+	<para>Switching to C++ is not an option, since the typing
+	overhead would be more than twice the current amount. As a
+	consequence the code would become much less readable.</para>
+
+	<para>Switching to OCaml looks nice (because of the type
+	inference), but the regular expressions that are provided by the
+	system are by no means sufficient. On the other hand, since
+	today there is a PCRE package for OCaml in pkgsrc.</para>
+
+</sect1>
+</chapter>
diff --git a/pkgtools/pkglint4/files/doc/chap.defs.xml b/pkgtools/pkglint4/files/doc/chap.defs.xml
new file mode 100644
index 00000000000..1bbee6f911a
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/chap.defs.xml
@@ -0,0 +1,26 @@
+<!-- $NetBSD: chap.defs.xml,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+<!-- don't include useless definitions.
+<chapter id="defs">
+<title>Definitions</title>
+
+	<para>In every non-toy program, the need arises to define new
+	words or redefine and clarify existing words. This is the list
+	of words that are used in pkglint.</para>
+
+	<variablelist>
+
+	<varlistentry><term>function</term><listitem><para>A subroutine
+	that is called to obtain a return value, rather than for its
+	side effects. Functions should restrict the user-visible side
+	effects to the necessary minimum.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term>procedure</term><listitem><para>A subroutine
+	that is not called to obtain a return value, but rather called
+	because of its side effects, like input/output.</para>
+	</listitem></varlistentry>
+
+	</variablelist>
+
+</chapter>
+-->
diff --git a/pkgtools/pkglint4/files/doc/chap.design.xml b/pkgtools/pkglint4/files/doc/chap.design.xml
new file mode 100644
index 00000000000..8ee3e98da96
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/chap.design.xml
@@ -0,0 +1,117 @@
+<!-- $NetBSD: chap.design.xml,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+
+<chapter id="design">
+<title>Design goals</title>
+
+	<para>&pkglint; should be simple to use. It should be consistent
+	and predictable in what it does. The diagnostics should be
+	understandable. The number of false positive and false negative
+	diagnostics should be minimal.</para>
+
+<sect1 id="design.simple-to-use">
+<title>Simple to use</title>
+
+	<para><emphasis>Requirement:</emphasis> Using &pkglint; should
+	not require any knowledge about obscure command line options or
+	hidden features.</para>
+
+	<para>Calling &pkglint; without options gives a useful amount of
+	warnings. No further knowledge is needed. Users that are
+	accustomed to GNU software will quickly find the
+	<literal>--help</literal> command line option, which gives a
+	quite verbose description of the available options. Users that
+	know the GNU compilers will easily remember the
+	<literal>-W</literal> class of options, especially
+	<literal>-Wall</literal>. Other than with the GNU compilers, the
+	latter option enables really <emphasis>all</emphasis> warnings
+	that are intended to be user-visible.</para>
+
+	<para>The command line options come in two flavors: short and
+	long options. The long options are meant to be used when
+	explaining them to others, while the short options are meant to
+	be used when invoking &pkglint; in an interactive shell.</para>
+
+</sect1>
+<sect1 id="design.consistent-and-predictable">
+<title>Consistent and predictable</title>
+
+	<para><emphasis>Requirement:</emphasis> &pkglint; should behave
+	such that the user quickly gets an impression about what
+	&pkglint; does. This impression should be persistent, that is,
+	the output format for diagnostics should be stable over time,
+	and diagnostic messages should not be changed without
+	reason.</para>
+
+	<para>There are only two cases of what the output of
+	&pkglint; is. One is a single line containing the text
+	<quote>looks fine.</quote>, the other is a list of diagnostics,
+	followed by a summary on the number of diagnostics.</para>
+
+	<para>If no warnings are printed, the single line <quote>looks
+	fine.</quote> gives a little motivation to the user. This
+	message is one of the few things that have been kept in
+	&pkglint; since it has been adopted from FreeBSD. It just makes
+	pkglint a more friendly tool. :)</para>
+
+	<para>All error and warning messages are formatted by a single
+	procedure, <function>PkgLint::Logging::log_message</function>. This
+	way, all messages are formatted the same way, which allows easy
+	recognition by human users as well as other tools. There are two
+	different formats available, the traditional one and the gcc-like
+	one. In both formats, each diagnostic occupies exactly one line. Up
+	to the year 2005, some of the longer messages used to take more than
+	one line, but this behavior has been removed.</para>
+
+	<para>The default format is the traditional one. It consists of the
+	severity, in upper-case letters, followed by the filename, the line
+	number and finally the message text. It allows easy recognition of
+	the severity of the messages. Even if errors and warnings are
+	intermixed in the output, the filenames start almost in the same
+	column.</para>
+
+	<para>The gcc-like output format consists of the filename, the line
+	numbers, the severity and finally the message text. It has been
+	added to make it easier to integrate the &pkglint; diagnostics into
+	various text editors, for example Emacs. Since in this format the
+	filename is the first word, it can be easily seen which warning
+	originates in which file.</para>
+
+	<para>There are some other procedures that affect the output, but
+	they have to be enabled explicitly.</para>
+
+</sect1>
+<sect1 id="design.understandable">
+<title>Understandable diagnostics</title>
+
+	<para><emphasis>Requirement:</emphasis> The diagnostics are
+	intended to help the user in writing better package definitions.
+	They should use an unambiguous, clear language and point
+	directly to the problem. If possible, they should include a hint
+	on how the problem can be fixed properly.</para>
+
+</sect1>
+<sect1 id="design.false-diagnostics">
+<title>Few false diagnostics</title>
+
+	<para><emphasis>Requirement:</emphasis> The number of
+	<firstterm>false positives</firstterm>, that is diagnostics
+	where no problem actually exists, should be minimal. On the
+	other hand, &pkglint; should detect as many problems as
+	possible. If it fails to detect a problem, this is called a
+	<firstterm>false negative</firstterm>.</para>
+
+	<para>Currently, there are very few false positives. The way
+	&pkglint; parses the files is already close to the way
+	<command>make</command> and <command>sh</command> parse them, so
+	the structure of the files is modelled quite well.</para>
+
+	<para>Since &pkglint; is also very strict in what it accepts,
+	many problems can already be detected. But since the pkgsrc
+	developers are quite creative when it comes to solving problems,
+	&pkglint; cannot detect everything. After all, the language used
+	to define packages is turing-complete, so it cannot be decided
+	in every case whether a package is valid or not. Luckily, most
+	packages are quite simple.</para>
+
+</sect1>
+</chapter>
diff --git a/pkgtools/pkglint4/files/doc/chap.future.xml b/pkgtools/pkglint4/files/doc/chap.future.xml
new file mode 100644
index 00000000000..e76cd43c4f6
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/chap.future.xml
@@ -0,0 +1,91 @@
+<!-- $NetBSD: chap.future.xml,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+
+<chapter id="future">
+<title>Future directions</title>
+
+<sect1 id="future.tokenize">
+<title>Tokenizing the input</title>
+
+	<para>For providing more exact diagnostics, it would be nice if
+	&pkglint; could point the user to the exact character position
+	of the smallest problematic text in a file. To do this, the
+	file's contents has to be splitted into tokens.</para>
+
+	<para>Doing this is nontrivial, since the tokenizing scheme
+	depends on the context in which the tokens are used. For
+	example, the <varname>COMMENT</varname> variable may contain
+	arbitrary characters (including <literal>'</literal> and
+	<literal>"</literal>), whereas in many other contexts these are
+	parts of quoted shell words.</para>
+
+</sect1>
+<sect1 id="future.ast">
+<title>Working on abstract syntax trees (AST)</title>
+
+	<para>When the tokenizing above is done, the tokens could be
+	parsed by a grammar to form abstract syntax trees. These would
+	consist mainly of function application so that pkglint can infer
+	types and valid values over these trees. The following functions
+	are likely to appear.</para>
+
+	<table id="future.ast.func">
+	<title>Functions in the abstract syntax trees</title>
+	<tgroup cols="2">
+	<thead><row><entry>Function</entry><entry>Purpose</entry></row></thead>
+	<tbody>
+	<row><entry><function>quote</function>(Val)</entry><entry>The <literal>:Q</literal> modifier</entry></row>
+	<row><entry><function>append</function>(Val, Val)</entry><entry>The <literal>+=</literal> operator</entry></row>
+	<row><entry><function>concat</function>(Val, Val)</entry><entry>The direct concatenation of two values</entry></row>
+	<row><entry><function>subst</function>(Val, Subst)</entry><entry>The <literal>:S</literal> and <literal>:C</literal> modifiers</entry></row>
+	<row><entry><function>shell</function>(Val)</entry><entry>The <literal>!=</literal> operator and the <literal>:sh</literal> modifier</entry></row>
+	<row><entry><function>literal</function>(Val)</entry><entry>Introduces literal values</entry></row>
+	</tbody>
+	</tgroup>
+	</table>
+
+	<para>Examples:</para>
+
+<programlisting>
+    WRKSRC=                 ${WRKDIR}
+    SUBST_SED.pkglint+=     -e s\|@DATADIR@\|${PREFIX:Q}/share/pkglint\|g
+</programlisting>
+
+	<para>The first line would be parsed as
+	<literal>assign(var("WRKSRC"), varuse("WRKDIR"))</literal>. The
+	second line would be parsed as
+	<literal>assign(var("SUBST_SED.pkglint"),
+	append(varuse("SUBST_SED.pkglint"), concat(concat(str("-e
+	s\\|@DATADIR@\\|"), quote(varuse("PREFIX"))),
+	str("/share/pkglint\\|g"))))</literal>.</para>
+
+	<para>At this point, unification together with a pattern matcher
+	on tree structures would come in handy, to allow the parser for
+	the shell commands to still operate on this parse tree. This
+	might eventually enable cross-language type inference.</para>
+
+</sect1>
+<sect1 id="future.vars">
+<title>Even more restricted variables</title>
+
+	<para>Currently there are mainly two restrictions for variables:
+	What values they may contain (data types) and where they may be
+	defined and used, on a per-file basis.</para>
+
+	<para>The <filename>makevars.map</filename> file already
+	contains annotations to distinguish user-defined from
+	system-defined variables, but they are currently only used as
+	abbreviations and not further exploited. Based on these
+	definitions, sequence points may be defined in the pkgsrc
+	infrastructure where the values of these variables must have
+	certain properties, like being defined or being fixed (which
+	means that the variable will not change further).</para>
+
+	<para>For example, user-defined variables may then be specified
+	as follows. They are given default values in
+	<filename>mk/defaults/mk.conf</filename>, may be overridden by
+	any file that is included inside <varname>MAKECONF</varname>,
+	and after that, their value is fixed. They may then be used at
+	both load and run time.</para>
+
+</sect1>
+</chapter>
diff --git a/pkgtools/pkglint4/files/doc/chap.intro.xml b/pkgtools/pkglint4/files/doc/chap.intro.xml
new file mode 100644
index 00000000000..f9c118eff8c
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/chap.intro.xml
@@ -0,0 +1,15 @@
+<!-- $NetBSD: chap.intro.xml,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+
+<chapter id="intro">
+<title>Introduction</title>
+
+	<para>&pkglint; is a static analysis tool for pkgsrc packages.
+	It finds many errors and problematic issues in those packages.
+	Starting in June 2004, &pkglint; has evolved into a powerful
+	tool that gives precise warnings wherever possible. With that
+	power comes much additional complexity, which cannot be
+	understood from reading the source code alone. This document
+	provides the necessary background information to understand what
+	the actual code does and why it is done this way.</para>
+
+</chapter>
diff --git a/pkgtools/pkglint4/files/doc/chap.statemachines.xml b/pkgtools/pkglint4/files/doc/chap.statemachines.xml
new file mode 100644
index 00000000000..42f5b1792fe
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/chap.statemachines.xml
@@ -0,0 +1,77 @@
+<!-- $NetBSD: chap.statemachines.xml,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+
+<chapter id="statemachines">
+<title>State machines</title>
+
+	<para>This chapter explains the various state machines that are
+	used in &pkglint;. It also provides graphical representations of
+	them that are much easier to read than the source code.</para>
+
+	<para>The opaque arrows in the figures represent transitions
+	that have a regular expression as condition. The hollow arrows
+	are the default transitions if nothing else matches. When
+	multiple regular expressions match in a state, the one that
+	appears first in the source code is chosen.</para>
+
+<sect1 id="statemachines.shellword">
+<title>The state machine for shell words</title>
+
+	<para>The state machine for single shell words is pretty simple,
+	and I think it can be understood from the source code alone. So
+	no graphical representation is provided.</para>
+
+</sect1>
+
+<sect1 id="statemachines.shellcommand">
+<title>The state machine for shell commands</title>
+
+	<figure id="statemachine.shellcommand">
+	<title>The state transitions for shell commands</title>
+	<mediaobject>
+	<imageobject>
+	<imagedata fileref="statemachine.shellcmd.png" format="PNG"/>
+	</imageobject>
+	<textobject><para>(Here should be a drawing of the state transitions.)</para></textobject>
+	</mediaobject>
+	</figure>
+
+	<para>The punch card symbols provide a means to go to a certain
+	state whenever the input matches the text on the punch
+	card.</para>
+
+</sect1>
+
+<sect1 id="statemachines.patch">
+<title>The state machine for patch files</title>
+
+	<para>The state machine for patch files is the newest of the
+	state machines. Here, the state transitions are separated from
+	the code, which makes the code itself pretty small. I don't know
+	yet if this programming style is elegant or not. Time will
+	show.</para>
+
+	<figure id="statemachine.patch">
+	<title>The state transitions for patch files</title>
+	<mediaobject>
+	<imageobject>
+	<imagedata fileref="statemachine.patch.png" format="PNG"/>
+	</imageobject>
+	<textobject><para>(Here should be a drawing of the state transitions.)</para></textobject>
+	</mediaobject>
+	</figure>
+
+	<para>The states on the left side are for parsing context diffs,
+	the ones on the right side are for unified diffs. Some of the
+	state names are highly abbreviated as follows. The first letter
+	gives the format of the patch, which is <quote>c</quote> for
+	context diffs and <quote>u</quote> for unified diffs. The second
+	letter gives the current syntactical level, which is
+	<quote>f</quote> for a file header, <quote>h</quote> for a hunk
+	header, or <quote>l</quote> for the hunk lines. The third letter
+	describes the action that belongs to the line, which is
+	<quote>a</quote> for an addition, and <quote>d</quote> for a
+	deletion.</para>
+
+</sect1>
+
+</chapter>
diff --git a/pkgtools/pkglint4/files/doc/chap.types.xml b/pkgtools/pkglint4/files/doc/chap.types.xml
new file mode 100644
index 00000000000..77f21c6548f
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/chap.types.xml
@@ -0,0 +1,545 @@
+<!-- $NetBSD: chap.types.xml,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+
+<chapter id="types">
+<title>The &pkglint; type system</title>
+
+	<para>One of the most notable additions to &pkglint; is the
+	introduction of typed variables. Traditionally, in
+	<filename>Makefile</filename>s, all variables have the type
+	<type>String</type>. This prevents many useful checks from being
+	done before executing the code.</para>
+
+	<para>Up to 2004, &pkglint; already did some checks based on
+	the value of the variables, but these checks had no common
+	structure that could be described easily.</para>
+
+<sect1 id="types.history">
+<title>History</title>
+
+	<para>In February 2005, initial support for the &pkglint; type
+	system has been added. Some of the common variables have been
+	assigned types such as <literal><type>Boolean</type></literal>
+	or <literal><type>Yes_Or_Undefined</type></literal>, which are
+	the two common ways to represent boolean variables in pkgsrc.
+	The list of typed variables has been moved from the &pkglint;
+	code to an external file, <filename>makevars.map</filename>.
+	Many more basic types have been added later.</para>
+
+	<para>In October 2005, the type system has been extended to
+	allow <literal><type>List of
+	<replaceable>simple-type</replaceable></type></literal>, which
+	allowed to handle variables like <varname>DEPENDS</varname> and
+	<varname>CFLAGS</varname>. One month later, enumeration types
+	have been added, allowing the type of
+	<varname>PTHREAD_OPTS</varname> to be expressed as <literal>List
+	of { require native }</literal>.</para>
+
+	<para>In May 2006, the definition and use of variables has been
+	further restricted by introducing ACLs, which define the
+	permitted operations (write, append, default, read, preprocess-read)
+	depending on the current file.</para>
+
+</sect1>
+
+<sect1 id="types.syntax">
+<title>Syntax for defining types</title>
+
+<programlisting>
+    type             ::= (list-type)? simple-type (acls)?
+
+    list-type        ::= ("List" | "InternalList") "of"
+
+    simple-type      ::= predefined-type
+                     |   enumeration
+    predefined-type  ::= [A-Za-z][0-9A-Z_a-z]*
+    enumeration      ::= "{" (enumeration-item)* "}"
+    enumeration-item ::= [-0-9A-Z_a-z]+
+
+    acls             ::= "[" (acl-entry ("," acl-entry)*)? "]"
+    acl-entry        ::= acl-subject ":" acl-perms
+    acl-subject      ::= [.0-9A-Za-z]+ | "_"
+    acl-perms        ::= [adprs]*
+</programlisting>
+
+</sect1>
+<sect1 id="types.semantics">
+<title>Semantics of the types</title>
+
+	<para>The <firstterm>simple types</firstterm> in &pkglint; are
+	either predefined types or enumeration types. A
+	<firstterm>predefined type</firstterm> is used by its name. See
+	<xref linkend="types.predefined"/> for the list of predefined
+	types.</para>
+
+	<para>An expression of an enumeration type may have either of
+	the enumeration-items as a value. It may not reference other
+	variables.</para>
+
+	<para>A list type can be constructed from a predefined type or
+	an enumeration. It is not possible to construct lists of lists,
+	since I have never needed that. There are two types of lists,
+	called <literal>List</literal> and
+	<literal>InternalList</literal>, which are described in the
+	<ulink url="&pkgsrc-guide;/makefile.html">pkgsrc guide, the
+	chapter about <filename>Makefile</filename>s</ulink>.</para>
+
+</sect1>
+<sect1 id="types.acls">
+<title>Access Control Lists</title>
+
+	<para>Additionally to the data type, which specifies
+	<emphasis>what</emphasis> a variable can contain, the ACLs
+	define <emphasis>where</emphasis> the variable can be defined or
+	used (this is called the <firstterm>ACL subject</firstterm>) and
+	which operations are allowed (these are the <firstterm>ACL
+	permissions</firstterm>).</para>
+
+	<para>The ACL subjects are specified by the filename. For
+	example, <filename>Makefile</filename> and
+	<filename>buildlink3.mk</filename> are valid ACL subjects. Since
+	some names occur over an over in pkgsrc, these can be
+	abbreviated as shown in <xref linkend="types.acl.subjects.abbr"
+	/>. The character <literal>*</literal> is a placeholder for zero
+	or more arbitrary characters, like in the shell. The possible
+	actions on a variable are shown in <xref
+	linkend="types.acl.perms" />.</para>
+
+	<table id="types.acl.subjects.abbr">
+	<title>ACL Subjects</title>
+	<tgroup cols="2">
+	<thead><row><entry>Subject</entry><entry>Abbreviation</entry></row></thead>
+	<tbody>
+	<row><entry><filename>Makefile</filename></entry><entry>m</entry></row>
+	<row><entry><filename>Makefile.common</filename></entry><entry>c</entry></row>
+	<row><entry><filename>buildlink3.mk</filename></entry><entry>b</entry></row>
+	<row><entry><filename>hacks.mk</filename></entry><entry>h</entry></row>
+	<row><entry><filename>options.mk</filename></entry><entry>o</entry></row>
+	<row><entry>any file</entry><entry>*</entry></row>
+	</tbody>
+	</tgroup>
+	</table>
+
+	<table id="types.acl.perms">
+	<title>ACL Permissions</title>
+	<tgroup cols="2">
+	<thead><row><entry>Permission</entry><entry>Description</entry></row></thead>
+	<tbody>
+	<row><entry><filename>a</filename></entry><entry>Append to the
+	variable using the <literal>+=</literal> operator.</entry></row>
+	<row><entry><filename>d</filename></entry><entry>Provide a
+	default value for the variable using the <literal>?=</literal>
+	operator.</entry></row>
+	<row><entry><filename>s</filename></entry><entry>Set the
+	variable unconditionally using the <literal>=</literal>,
+	<literal>:=</literal> or <literal>!=</literal>
+	operator.</entry></row>
+	<row><entry><filename>u</filename></entry><entry>Use the value
+	of the variable.</entry></row>
+	<row><entry><filename>p</filename></entry><entry>Use the value
+	of the variable during preprocessing.</entry></row>
+	</tbody>
+	</tgroup>
+	</table>
+
+	<para>If a variable has no ACL definition at all, all operations
+	are allowed on it. Otherwise exactly those operations of the
+	first ACL entry whose subject matches the current filename are
+	allowed. If no entry matches, nothing is allowed.</para>
+
+	<para>For determining if a variable is used in the correct
+	place, the filename is only one part of the whole decision. The
+	other one is the context in which the variable appears. There
+	are many factors that influence whether the variable is used
+	correctly.</para>
+
+	<itemizedlist>
+
+	<listitem><para>The variable may be either used at preprocessing time
+	or at runtime. Some variables are defined in
+	<filename>bsd.pkg.mk</filename> and thus are not available until
+	that file has been included. As this should always be the very
+	last thing a package includes, it practically means that these
+	variables are only available at runtime.</para></listitem>
+
+	<listitem><para>The variable may appear as the whole right hand side
+	of an assignment, as a single word, or even as part of a word.
+	First, the types on the right and left side should be
+	compatible. Second, some variables need to be quoted correctly,
+	depending on whether they are part of a word or not.</para></listitem>
+
+	<listitem><para>In shell commands, the variable may also appear as a
+	whole word or as part of a word. This is similar to the case
+	above.</para></listitem>
+
+	<listitem><para>The variable may appear inside some sort of quotes.
+	For some variables this is acceptable, as they are assumed to
+	never contain special characters. For others it
+	isn't.</para></listitem>
+
+	<listitem><para>The various operators in conditional statements like
+	<literal>.if</literal> may further restrict the valid values.
+	For example, the <varname>OPSYS</varname> variable should only
+	be compared to well-known operating system names. The
+	<varname>exists()</varname> function should only be called on
+	pathnames. The <varname>defined()</varname> operator only checks
+	if the variable is defined and does not access its
+	value.</para></listitem>
+
+	</itemizedlist>
+
+<sect2 id="types.acls.future">
+<title>Future Directions</title>
+
+	<para>Currently the ACLs only cover the <quote>user
+	space</quote> of pkgsrc. They will be extended later to also
+	check for valid variable definition and use in the pkgsrc
+	infrastructure, as well as the user configuration file. For
+	completeness, those variables that are intended to be specified
+	on the command line will be added to the
+	<filename>makevars.map</filename> file.</para>
+
+</sect2>
+</sect1>
+<sect1 id="types.predefined">
+<title>Predefined types</title>
+
+	<para>There are many predefined types in &pkglint;, which are
+	described below.</para>
+
+	<!-- reference: pkglint.pl, revision 1.532 -->
+	<variablelist>
+
+	<varlistentry><term><literal><type>AwkCommand</type></literal></term>
+	<listitem><para>An awk command. Currently nothing is checked
+	here.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>BuildlinkDepmethod</type></literal></term>
+	<listitem><para>Must be either <literal>build</literal> or
+	<literal>full</literal>.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>BuildlinkDepth</type></literal></term>
+	<listitem><para>This type is only intended for one variable,
+	namely <varname>BUILDLINK_DEPTH</varname>, which is only
+	modified in <filename>buildlink3.mk</filename>
+	files.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>BuildlinkPackages</type></literal></term>
+	<listitem><para>The type of the variable
+	<varname>BUILDLINK_PACKAGES</varname>. Like
+	<literal><type>BuildlinkDepth</type></literal> above, this is
+	only used in <filename>buildlink3.mk</filename> files. This
+	variable has two different patterns to be modified. The first is
+	to remove the current package from itself, and the second is to
+	append the current package. This prevents a package from showing
+	up twice in the list.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Category</type></literal></term>
+	<listitem><para>One of the categories that a package may be
+	placed in. The list of categories has been assembled manually
+	when the type was introduced. There is no further agreement on
+	which valid categories are valid, besides the top level
+	directory names in pkgsrc.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>CFlag</type></literal></term>
+	<listitem><para>One word in a <varname>CFLAGS</varname> or
+	<varname>CPPFLAGS</varname> variable. &pkglint; knows the flags
+	starting with <literal>-D</literal>, <literal>-U</literal>,
+	<literal>-I</literal>. Flags starting with
+	<literal>-O</literal>, <literal>-W</literal>,
+	<literal>-f</literal>, <literal>-g</literal> or
+	<literal>-m</literal> are silently accepted since they are
+	commonly used for the GNU compilers. As the pkgsrc framework
+	does not know how to handle most of these flags, care should be
+	taken.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Comment</type></literal></term>
+	<listitem><para>The comment of a package.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Dependency</type></literal></term>
+	<listitem><para>A simple dependency like
+	<literal>foopkg>=1.0</literal>, <literal>foopkg-[0-9]*</literal>
+	or <literal>foopkg-1.0</literal>.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>DependencyWithPath</type></literal></term>
+	<listitem><para>A dependency (see above), followed by a colon
+	and a relative directory. For some packages, special variables
+	like <varname>USE_TOOLS</varname> should be used instead of an
+	explicit dependency.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>DistSuffix</type></literal></term>
+	<listitem><para>The value of the variable
+	<varname>EXTRACT_SUFX</varname>. The difference in the name is
+	intentional here, since <varname>EXTRACT_SUFX</varname> is a
+	misnomer. <varname>DIST_SUFX</varname> or
+	<varname>DIST_SUFFIX</varname> would be more appropriate.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>EmulPlatform</type></literal></term>
+	<listitem><para>An emulated platform consists of the operating
+	system (in lowercase, as opposed to <type>PlatformTriple</type>)
+	and the hardware architecture.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Filename</type></literal></term>
+	<listitem><para>A filename, as defined in <ulink
+	url="http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_169">POSIX</ulink>.
+	This type further restricts the set of allowed characters.
+	See also <literal><type>Pathname</type></literal>.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Filemask</type></literal></term>
+	<listitem><para>A shell globbing pattern that does not contain a
+	slash. See also <literal><type>Pathmask</type></literal>.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Identifier</type></literal></term>
+	<listitem><para>In various places in pkgsrc, identifiers are
+	used. This type collects the most common naming conventions.
+	When you need a more specific check, you have to write your own
+	check.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>LdFlag</type></literal></term>
+	<listitem><para>A flag that is passed to the linker. Flags
+	starting with <literal>-L</literal> or <literal>-l</literal> are
+	accepted, as well as some others that are assumed to be handled
+	by the wrapper framework.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Mail_Address</type></literal></term>
+	<listitem><para>Checks for a very restricted subset of <ulink
+	url="http://www.ietf.org/rfc/rfc2822.txt">RFC
+	2822</ulink>.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Message</type></literal></term>
+	<listitem><para>Messages are printed to the user as status
+	indicators. <ulink
+	url="http://www.freebsd.org/cgi/cvsweb.cgi/ports/devel/portlint/src/portlint.pl#rev1.77">As
+	opposed to FreeBSD</ulink>, they should not be quoted since they
+	may be used in contexts where quoting should be done
+	differently.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Option</type></literal></term>
+	<listitem><para>An option from the
+	<literal>PKG_OPTIONS</literal> framework. Options should not
+	contain underscores. They should be documented in
+	<filename>pkgsrc/mk/defaults/options.description</filename>.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Pathlist</type></literal></term>
+	<listitem><para>A list of directories that are separated by
+	colons, like the popular environment variable
+	<varname>PATH</varname>. This type differs from the type
+	<literal><type>List of Pathname</type></literal> in the
+	character that is used as a separator.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Pathmask</type></literal></term>
+	<listitem><para>A shell globbing expression that may include
+	slashes.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Pathname</type></literal></term>
+	<listitem><para>A pathname, as defined in <ulink
+	url="http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_266">POSIX</ulink>.
+	See also <literal><type>Filename</type></literal>.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Perl5Packlist</type></literal></term>
+	<listitem><para>A common error has been to refer to
+	<varname>INSTALLARCHLIB</varname> in the location of the packing
+	list. Therefore no references to other variables are
+	allowed.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>PkgName</type></literal></term>
+	<listitem><para>A package name should conform to some
+	restrictions, since the filename of the binary package is
+	created from it, which is then interpreted by pkg_add and the
+	like.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>PkgOptionsVar</type></literal></term>
+	<listitem><para>I had once made the mistake of referencing
+	<varname>PKGBASE</varname> in this variable, not knowing that
+	<varname>PKG_OPTIONS_VAR</varname> is used during preprocessing,
+	when <varname>PKGBASE</varname> is not yet defined. This type
+	prevent that mistake from being done again.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>PkgPath</type></literal></term>
+	<listitem><para>A directory name that is relative to the
+	top-level pkgsrc directory. This is only used in specifying
+	specific packages in bulk builds. Despite its name, this type is
+	more similar to <type>RelativePkgDir</type> than to
+	<type>RelativePkgPath</type>.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>PkgRevision</type></literal></term>
+	<listitem><para>The package revision must be a small integer.
+	The only place where this definition may occur is the package
+	<filename>Makefile</filename> itself, as this variable says
+	something about the individual package. There is no mechanism in
+	pkgsrc for something similar to <varname>PKGREVISION</varname>
+	that can be used in <filename>Makefile.common</filename>
+	files.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>PlatformTriple</type></literal></term>
+	<listitem><para>pkgsrc has been ported to many platforms, all of
+	which are identified using a triple of operating system,
+	operating system version and hardware
+	architecture.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Readonly</type></literal></term>
+	<listitem><para>This type is used to mark a variable as being
+	read-only to a package author. As this is not really a data type
+	but an access restriction, it will disappear in the next version
+	of the type system.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>RelativePkgDir</type></literal></term>
+	<listitem><para>A directory name that is relative to the package
+	directory. Mostly used for dependencies. See also
+	<literal><type>RelativePkgPath</type></literal>.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>RelativePkgPath</type></literal></term>
+	<listitem><para>A pathname that is relative to the package
+	directory. It may point to either a regular file or a directory.
+	See also <literal><type>RelativePkgDir</type></literal>.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>ShellCommand</type></literal></term>
+	<listitem><para>A shell command is similar to a
+	<literal><type>List of ShellWord</type></literal>, except that
+	additional checks are performed on the direct use of tool names
+	or certain other deprecated shell commands.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>ShellWord</type></literal></term>
+	<listitem><para>A shell word is what the shell would regard as a
+	single word.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Stage</type></literal></term>
+	<listitem><para>In pkgsrc, there are phases, stages and steps.
+	Especially for the <varname>SUBST_STAGE</varname> variable, this
+	should always be one of the few predefined names, otherwise the
+	whole substitution group will be ignored.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Tool</type></literal></term>
+	<listitem><para>The pkgsrc tools framework contains very few
+	plausibility checks. To prevent spelling mistakes, the list of
+	valid tool names is loaded from the pkgsrc infrastructure files
+	and compared with the names that are used in the
+	<varname>USE_TOOLS</varname> variable.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>URL</type></literal></term>
+	<listitem><para>URLs appear in <varname>MASTER_SITES</varname>
+	and the <varname>HOMEPAGE</varname>. If a
+	<varname>MASTER_SITES</varname> group exists for a given URL, it
+	should be used instead of listing the URL directly.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>UserGroupName</type></literal></term>
+	<listitem><para>User and group names should consist only of
+	alphanumeric characters and the underscore. This restriction
+	ensures maximum portability of pkgsrc.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Userdefined</type></literal></term>
+	<listitem><para>Another instance of misuse of the type system.
+	But it helps to catch some errors in packages. This type will
+	disappear in the next version of the type system. See also
+	<literal><type>Readonly</type></literal>.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Varname</type></literal></term>
+	<listitem><para>Variable names are restricted to only uppercase
+	letters and the underscore in the basename, and arbitrary
+	characters in the parameterized part, following the dot.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>WrkdirSubdirectory</type></literal></term>
+	<listitem><para>The variable <varname>WRKSRC</varname> is
+	usually defined with reference to <varname>WRKDIR</varname>.
+	This check currently does nothing, and I don't know if it's
+	worth to check anything here.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>WrksrcSubdirectory</type></literal></term>
+	<listitem><para>Subdirectories of <varname>WRKSRC</varname> can
+	be used in <varname>CONFIGURE_DIRS</varname> and some other
+	variables. For convenience, they are interpreted relative to
+	<varname>WRKSRC</varname>, so package authors don't have to type
+	<literal>${WRKSRC}</literal> all the time.</para>
+	</listitem></varlistentry>
+
+	<varlistentry><term><literal><type>Yes</type></literal></term>
+	<listitem><para>This type is used for variables that are checked
+	using <literal>defined(VARNAME)</literal>. Their value is
+	interpreted as <quote>true</quote> if they are defined, no
+	matter if they are set to <literal>yes</literal> or
+	<literal>no</literal>.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>YesNo</type></literal></term>
+	<listitem><para>This type is used for variables that are checked
+	using <literal>defined(VARNAME) &amp;&amp;
+	!empty(VARNAME:M[Yy][Ee][Ss])</literal>. A value of
+	<varname>no</varname> means <quote>no</quote> for
+	them.</para></listitem></varlistentry>
+
+	<varlistentry><term><literal><type>YesNoFromCommand</type></literal></term>
+	<listitem><para>Like <literal><type>YesNo</type></literal>, but
+	the value may be produced by a shell command using the
+	<literal>!=</literal> operator.</para></listitem></varlistentry>
+
+	</variablelist>
+
+</sect1>
+<sect1 id="types.future">
+<title>Future directions</title>
+
+<sect2 id="types.kinds">
+<title>Different interpretation of the same data types</title>
+
+	<para>As explained above, there are internal lists and external
+	lists in pkgsrc. But that is not the only attribute that a list
+	can have. They also differ in the way they are defined, which
+	files may access them, and what it means to append to append a
+	value to it.</para>
+
+	<para>For example, <varname>NOT_FOR_PLATFORM</varname> is a list
+	that every file may append to without leading to unexpected
+	behavior. Compare this with
+	<varname>ONLY_FOR_PLATFORM</varname>, which should only be set
+	in a single place throughout pkgsrc. Let's say in the package
+	<filename>Makefile</filename> it is set to
+	<literal>NetBSD-*-*</literal>, because this file's author knows
+	for sure that the package is only usable on NetBSD. Now when
+	some <filename>*.mk</filename> file from a dependency package
+	adds <literal>DragonFly-*-*</literal> to it, the intent of the
+	package <filename>Makefile</filename> is undermined by the
+	dependency package, because now it is possible to build the
+	package on DragonFly, too.</para>
+
+	<para>The same problem arises with the various variables that
+	can be either <literal>yes</literal> or undefined. They should
+	always be chosen so that two definitions in different files
+	don't undermine each other. A good example is
+	<varname>USE_LIBTOOL</varname>, a bad example is
+	<varname>NO_BUILD</varname>.</para>
+
+	<para>TODO: What are the general properties of
+	<quote>good</quote> and <quote>bad</quote> variables? How can it
+	be decided of which kind a certain variable is?</para>
+
+	<para>For most lists, the only valid operation is to append
+	something at the end. Therefore it is good practice to warn if a
+	list is assigned using another operator that
+	<literal>+=</literal>. For <varname>SUBST_CLASSES</varname> this
+	fits perfectly. But for <varname>SUBST_FILES.*</varname> it
+	doesn't. Usually all occurences of a
+	<varname>SUBST_FILES.*</varname> variable occur in the same
+	file, and there should be no other file modifying these
+	variables. Therefore it is better to use the
+	<literal>=</literal> operator for the first of the
+	assignments.</para>
+
+</sect2>
+</sect1>
+</chapter>
diff --git a/pkgtools/pkglint4/files/doc/pkglint.xml b/pkgtools/pkglint4/files/doc/pkglint.xml
new file mode 100644
index 00000000000..d49282e747d
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/pkglint.xml
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="iso-8859-1"?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
+	"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd"
+[
+	<!ENTITY pkglint "<literal>pkglint</literal>">
+	<!ENTITY pkgsrc-guide "http://www.NetBSD.org/docs/pkgsrc">
+
+	<!ENTITY chap.intro SYSTEM "chap.intro.xml">
+	<!ENTITY chap.defs SYSTEM "chap.defs.xml">
+	<!ENTITY chap.design SYSTEM "chap.design.xml">
+	<!ENTITY chap.types SYSTEM "chap.types.xml">
+	<!ENTITY chap.code SYSTEM "chap.code.xml">
+	<!ENTITY chap.statemachines SYSTEM "chap.statemachines.xml">
+	<!ENTITY chap.future SYSTEM "chap.future.xml">
+]>
+
+<!-- $NetBSD: pkglint.xml,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+
+<book>
+<title>Design and implementation of &pkglint;</title>
+
+<bookinfo>
+<author>
+	<firstname>Roland</firstname>
+	<surname>Illig</surname>
+	<email>rillig@NetBSD.org</email>
+</author>
+</bookinfo>
+
+&chap.intro;
+&chap.defs;
+&chap.design;
+&chap.types;
+&chap.code;
+&chap.statemachines;
+&chap.future;
+
+</book>
diff --git a/pkgtools/pkglint4/files/doc/statemachine.patch.dia b/pkgtools/pkglint4/files/doc/statemachine.patch.dia
new file mode 100644
index 00000000000..bf1aac9919d
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/statemachine.patch.dia
diff --git a/pkgtools/pkglint4/files/doc/statemachine.shellcmd.dia b/pkgtools/pkglint4/files/doc/statemachine.shellcmd.dia
new file mode 100644
index 00000000000..76b7442f210
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/statemachine.shellcmd.dia
diff --git a/pkgtools/pkglint4/files/doc/stylesheet.xsl b/pkgtools/pkglint4/files/doc/stylesheet.xsl
new file mode 100644
index 00000000000..078cb37470d
--- /dev/null
+++ b/pkgtools/pkglint4/files/doc/stylesheet.xsl
@@ -0,0 +1,6 @@
+<!-- $NetBSD: stylesheet.xsl,v 1.1 2015/11/25 16:42:21 rillig Exp $ -->
+
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+	version="1.0">
+  <xsl:param name="html.longdesc" select="0"/>
+</xsl:stylesheet>
diff --git a/pkgtools/pkglint4/files/makevars.map b/pkgtools/pkglint4/files/makevars.map
new file mode 100644
index 00000000000..d2bd19afcd7
--- /dev/null
+++ b/pkgtools/pkglint4/files/makevars.map
@@ -0,0 +1,768 @@
+# $NetBSD: makevars.map,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+
+# This file contains the guessed type of some variables, according to
+# their current use in pkgsrc.
+#
+# The type YesNo is used for variables that are checked using
+#     .if defined(VAR) && !empty(VAR:M[Yy][Ee][Ss])
+#
+# The type Yes is used for variables that are checked using
+#     .if defined(VAR)
+#
+# The type List is used for lists of things. There are two types of lists,
+# InternalList and List, which are described in the pkgsrc guide, chapter
+# "Makefiles".
+#
+# The other types are described in pkglint.pl, checkline_mk_vartype_basic.
+#
+
+#
+# Some commonly used ACLs. For further documentation, see the chapter
+# ``The pkglint type system'' in the pkglint developer documentation.
+#
+
+# A package-defined variable may be set in Makefile, Makefile.common or
+# options.mk, since these are commonly used in pkgsrc. Due to the
+# special nature of buildlink3.mk and builtin.mk files, these files may
+# not define those variables. All other .mk files may, allowing for
+# application.mk or similar helper files.
+acl package = [m:su, c:dsu, b:, builtin.mk:, *.mk:dsu]
+
+# A package_list may be appended to in all "normal" Makefile fragments.
+# This excludes buildlink3.mk and builtin.mk, since they are very
+# special-purpose. Because at the beginning, all lists are empty, in the
+# primary Makefile a direct assignment may be used instead of appending.
+# Since Makefile.common files are usually used by packages that know
+# what they are doing, they may set variables directly, too. This rule
+# can be removed to show a lot of possible problems in pkgsrc.
+acl package_list = [m:asu, c:asu, b:, builtin.mk:, *.mk:au]
+acl bl_list = [b:a, builtin.mk:a]
+
+# A user-defined or system-defined variable must not be set by any
+# package file. It also must not be used in buildlink3.mk and
+# builtin.mk files or at load-time, since the system/user preferences
+# may not have been loaded when these files are included.
+acl user = [b:, builtin.mk:, *:u]
+acl system = [b:, builtin.mk:u, *:u]
+acl cmdline = [b:, builtin.mk:, *:pu]
+
+# The following variables are taken from mk/defaults/mk.conf, 1.118
+
+ALLOW_VULNERABLE_PACKAGES	Yes [$user]
+MANINSTALL			List of { maninstall catinstall } [$user]
+MANZ				Yes [$user]
+GZIP				List of ShellWord [$user]
+MKCRYPTO			YesNo [$user]
+OBJHOSTNAME			Yes [$user]
+OBJMACHINE			Yes [$user]
+PKG_SUFX			Filename [$user]
+PKGSRC_LOCKTYPE			{ none sleep once } [$user]
+PKGSRC_SLEEPSECS		Integer [$user]
+USETBL				Yes [$user]
+ABI				{ 32 64 } [$user]
+PKG_DEVELOPER			Yes [$user]
+USE_ABI_DEPENDS			YesNo [$user]
+PKG_REGISTER_SHELLS		{ YES NO } [$user]
+PKGSRC_COMPILER			List of { \
+					ccache ccc clang distcc f2c gcc hp icc \
+					ido gcc mipspro mipspro-ucode pcc \
+					sunpro xlc \
+				} [$user]
+PKGSRC_MESSAGE_RECIPIENTS	List of Mail_Address [$user]
+PKGSRC_SHOW_BUILD_DEFS		YesNo [$user]
+PKGSRC_SHOW_PATCH_ERRORMSG	YesNo [$user]
+PKGSRC_RUN_TEST			YesNo [$user]
+PREFER_PKGSRC			List of Identifier [$user]
+PREFER_NATIVE			List of Identifier [$user]
+PREFER_NATIVE_PTHREADS		YesNo [$user]
+LOCALBASE			Pathname [$user]
+CROSSBASE			Pathname [$user]
+VARBASE				Pathname [$user]
+X11_TYPE			{ modular native } [$user]
+X11BASE				Pathname [$user]
+MOTIFBASE			Pathname [$user]
+PKGINFODIR			Pathname [$user]
+PKGMANDIR			Pathname [$user]
+USE_XPKGWEDGE			YesNo [$user]
+BSDSRCDIR			Pathname [$user]
+BSDXSRCDIR			Pathname [$user]
+DISTDIR				Pathname [$user]
+DIST_PATH			Pathlist [$user]
+DEFAULT_VIEW			Unchecked [$user]
+FETCH_CMD			ShellCommand [$user]
+FETCH_USING			{ curl custom fetch ftp manual wget } [$user]
+FETCH_RESUME_ARGS		List of ShellWord [$user]
+FETCH_OUTPUT_ARGS		List of ShellWord [$user]
+LIBTOOLIZE_PLIST		YesNo [$user]
+PKG_RESUME_TRANSFERS		YesNo [$user]
+PKG_SYSCONFBASE			Pathname [$user]
+RCD_SCRIPTS_DIR			Pathname [$user]
+PACKAGES			Pathname [$user]
+PKGVULNDIR			Pathname [$user]
+PASSIVE_FETCH			Yes [$user]
+PATCH_FUZZ_FACTOR		{ -F0 -F1 -F2 -F3 } [$user]
+ACCEPTABLE_LICENSES		List of Identifier [$user]
+SPECIFIC_PKGS			Yes [$user]
+SITE_SPECIFIC_PKGS		List of PkgPath [$user]
+HOST_SPECIFIC_PKGS		List of PkgPath [$user]
+GROUP_SPECIFIC_PKGS		List of PkgPath [$user]
+USER_SPECIFIC_PKGS		List of PkgPath [$user]
+FAILOVER_FETCH			Yes [$user]
+MASTER_SORT			List of Unchecked [$user]
+MASTER_SORT_REGEX		List of Unchecked [$user]
+PATCH_DEBUG			Yes [$user]
+PKG_FC				ShellCommand [$user]
+IMAKE				ShellCommand [$user]
+IMAKEOPTS			List of ShellWord [$user]
+PRE_ROOT_CMD			ShellCommand [$user]
+USE_GAMESGROUP			YesNo [$package]
+SU_CMD				ShellCommand [$user]
+SU_CMD_PATH_APPEND		Pathlist [$user]
+FATAL_OBJECT_FMT_SKEW		YesNo [$user]
+WARN_NO_OBJECT_FMT		YesNo [$user]
+SMART_MESSAGES			Yes [$user]
+BINPKG_SITES			List of URL [$user]
+BIN_INSTALL_FLAG		List of ShellWord [$user]
+LOCALPATCHES			Pathname [$user]
+
+# some other variables, sorted alphabetically
+
+.CURDIR			Pathname [$system]
+.TARGET			Pathname [$system]
+ALL_ENV			List of ShellWord
+ALTERNATIVES_FILE	Filename
+ALTERNATIVES_SRC	List of Pathname
+APACHE_MODULE		Yes [$package]
+AR			ShellCommand [$system]
+AS			ShellCommand [$system]
+AUTOCONF_REQD		List of Version [$package_list]
+AUTOMAKE_OVERRIDE	List of Pathmask
+AUTOMAKE_REQD		List of Version [$package_list]
+AUTO_MKDIRS		YesNo [$package]
+BATCH			Yes [$user]
+BDB185_DEFAULT		Unchecked []
+BDBBASE			Pathname [$system]
+BDB_ACCEPTED		List of { db1 db2 db3 db4 db5 } [$package]
+BDB_DEFAULT		{ db1 db2 db3 db4 db5 } []
+BDB_LIBS		List of LdFlag [$system]
+BDB_TYPE		{ db1 db2 db3 db4 db5 } [$system]
+BINGRP			UserGroupName [$system]
+BINMODE			FileMode [$system]
+BINOWN			UserGroupName [$system]
+BOOTSTRAP_DEPENDS	InternalList of DependencyWithPath [c:a,m:a,o:a,*.mk:a]
+BOOTSTRAP_PKG		YesNo [$package]
+BROKEN			Message []
+BROKEN_GETTEXT_DETECTION	YesNo [$package]
+BROKEN_EXCEPT_ON_PLATFORM	List of PlatformTriple [$package_list]
+BROKEN_ON_PLATFORM	InternalList of PlatformTriple [$package_list]
+BSD_MAKE_ENV		List of ShellWord [$system]
+BUILDLINK_ABI_DEPENDS.*	InternalList of Dependency [*:a]
+BUILDLINK_API_DEPENDS.*	InternalList of Dependency [*:a]
+BUILDLINK_CONTENTS_FILTER	List of ShellWord []
+# ^^ ShellCommand
+BUILDLINK_CFLAGS	List of CFlag [$system]
+BUILDLINK_CFLAGS.*	List of CFlag [$bl_list]
+BUILDLINK_CPPFLAGS	List of CFlag [$system]
+BUILDLINK_CPPFLAGS.*	List of CFlag [$bl_list]
+BUILDLINK_CONTENTS_FILTER.*	ShellCommand [b:s]
+BUILDLINK_DEPENDS	InternalList of Identifier [b:a]
+BUILDLINK_DEPMETHOD.*	List of BuildlinkDepmethod [b:ad,m:as,c:a,*.mk:a]
+# ^^ FIXME: b:d may lead to unexpected behavior.
+BUILDLINK_DEPTH		BuildlinkDepth [b:ps, builtin.mk:ps]
+BUILDLINK_DIR		Pathname [$system]
+BUILDLINK_FILES.*	List of Pathmask [$bl_list]
+BUILDLINK_FILES_CMD.*	List of ShellWord []
+# ^^ ShellCommand
+BUILDLINK_INCDIRS.*	List of Pathname [b:ad]			# b:d?
+BUILDLINK_JAVA_PREFIX.*	Pathname [b:s]
+BUILDLINK_LDADD.*	List of LdFlag [builtin.mk:adsu, b:, m:u, c:u, *.mk:u]
+BUILDLINK_LDFLAGS	List of LdFlag [$system]
+BUILDLINK_LDFLAGS.*	List of LdFlag [$bl_list]
+BUILDLINK_LIBDIRS.*	List of Pathname [$bl_list]
+BUILDLINK_LIBS.*	List of LdFlag [b:a]
+BUILDLINK_PACKAGES	BuildlinkPackages [b:aps]
+BUILDLINK_PASSTHRU_DIRS	List of Pathname [m:a,c:a,b:a,h:a]
+BUILDLINK_PASSTHRU_RPATHDIRS	List of Pathname [m:a,c:a,b:a,h:a]
+BUILDLINK_PKGSRCDIR.*	RelativePkgDir [b:dp]
+BUILDLINK_PREFIX.*	Pathname [builtin.mk:su, b:, m:u, c:u, *.mk:u]
+BUILDLINK_RPATHDIRS.*	List of Pathname [b:a]
+BUILDLINK_TARGETS	List of Identifier []
+BUILDLINK_FNAME_TRANSFORM.*	SedCommands [m:a,builtin.mk:a,h:a,b:a]
+BUILDLINK_TRANSFORM	List of WrapperTransform [*:a]
+BUILDLINK_TREE		List of Identifier [b:a]
+BUILD_DEFS		List of Varname [m:a,c:a,o:a]
+BUILD_DEPENDS		InternalList of DependencyWithPath [c:a,m:a,o:a,*.mk:a]
+BUILD_DIRS		List of WrksrcSubdirectory [$package_list]
+BUILD_ENV		List of ShellWord [$package_list]
+BUILD_MAKE_CMD		ShellCommand [$system]
+BUILD_MAKE_FLAGS	List of ShellWord [$package_list]
+BUILD_TARGET		List of Identifier [$package]
+BUILD_USES_MSGFMT	Yes [$package]
+BUILTIN_PKG		Identifier [builtin.mk:psu]
+BUILTIN_PKG.*		PkgName [builtin.mk:psu]
+BUILTIN_FIND_FILES_VAR	List of Varname [builtin.mk:s]
+BUILTIN_FIND_FILES.*	List of Pathname [builtin.mk:s]
+BUILTIN_FIND_GREP.*	String [builtin.mk:s]
+BUILTIN_FIND_LIBS	List of Pathname [builtin.mk:s]
+BUILTIN_IMAKE_CHECK	List of Unchecked [builtin.mk:s]
+BUILTIN_IMAKE_CHECK.*	YesNo []
+BUILTIN_X11_TYPE	Unchecked [$system]
+BUILTIN_X11_VERSION	Unchecked [$system]
+CATEGORIES		List of Category [m:as,c:ads]
+CC_VERSION		Message [$system]
+CC			ShellCommand [$system]
+CFLAGS*			List of CFlag [$package_list]
+# ^^ may also be changed by the user
+CHECK_BUILTIN		YesNo [builtin.mk:d,m:s]
+CHECK_BUILTIN.*		YesNo [*:p]
+CHECK_FILES_SKIP	List of Pathmask [m:a,c:a]
+CHECK_FILES_SUPPORTED	YesNo [$package]
+CHECK_HEADERS		YesNo [$user]
+CHECK_HEADERS_SKIP	List of Pathmask [$package_list]
+CHECK_INTERPRETER	YesNo [$user]
+CHECK_INTERPRETER_SKIP	List of Pathmask [$package_list]
+CHECK_PERMS		YesNo [$user]
+CHECK_PERMS_SKIP	List of Pathmask [$package_list]
+#CHECK_PERMS_AUTOFIX	YesNo [$package]
+# ^^ experimental
+CHECK_PORTABILITY	YesNo [$user]
+CHECK_PORTABILITY_SKIP	List of Pathmask [$package_list]
+CHECK_SHLIBS		YesNo [m:s]
+CHECK_SHLIBS_SKIP	List of Pathmask [$package_list]
+CHECK_SHLIBS_SUPPORTED	YesNo [m:s]
+CHECK_WRKREF_SKIP	List of Pathmask [$package_list]
+CMAKE_ARG_PATH		Pathname [$package]
+CMAKE_ARGS		List of ShellWord [$package_list]
+COMMENT			Comment [m:as,c:as]
+COMPILER_RPATH_FLAG	{ -Wl,-rpath } [$system]
+CONFIGURE_ARGS		List of ShellWord [$package_list]
+CONFIGURE_DIRS		List of WrksrcSubdirectory [$package_list]
+CONFIGURE_ENV		List of ShellWord [$package_list]
+CONFIGURE_HAS_INFODIR	YesNo [$package]
+CONFIGURE_HAS_LIBDIR	YesNo [$package]
+CONFIGURE_HAS_MANDIR	YesNo [$package]
+CONFIGURE_SCRIPT	Pathname [$package]
+CONFIG_GUESS_OVERRIDE	List of Pathmask [m:as,c:as]
+CONFIG_STATUS_OVERRIDE	List of Pathmask [m:as,c:as]
+CONFIG_SHELL		Pathname [m:s,c:s]
+CONFIG_SUB_OVERRIDE	List of Pathmask [m:as,c:as]
+CONFLICTS		InternalList of Dependency [$package_list]
+CONF_FILES		List of ShellWord [$package_list]
+CONF_FILES_MODE		{ 0644 0640 0600 0400 } [$package]
+CONF_FILES_PERMS	List of ShellWord [$package_list]
+COPY			{ -c } [$system]
+# ^^ the flag that tells ${INSTALL} to copy a file
+CPP			ShellCommand [$system]
+CPPFLAGS*		List of CFlag [$package_list]
+CRYPTO			Yes [m:s]
+CXX			ShellCommand [$system]
+CXXFLAGS*		List of CFlag [$package_list]
+DEINSTALL_FILE		Pathname [m:s]
+DEINSTALL_SRC		List of Pathname [m:s,c:ds]
+DEINSTALL_TEMPLATES	List of Pathname [m:as,c:ads]
+DELAYED_ERROR_MSG	ShellCommand [$system]
+DELAYED_WARNING_MSG	ShellCommand [$system]
+DEPENDS			InternalList of DependencyWithPath [$package_list]
+DEPENDS_TARGET		List of Identifier [$user]
+DESCR_SRC		List of Pathname [m:s,c:ds]
+DESTDIR			Pathname [$system]
+DESTDIR_VARNAME		Varname [m:s,c:s]
+DEVOSSAUDIO		Pathname [$system]
+DEVOSSSOUND		Pathname [$system]
+DISTFILES		List of Filename [$package_list]
+DISTINFO_FILE		RelativePkgPath [$package]
+DISTNAME		Filename [$package]
+DIST_SUBDIR		Pathname [$package]
+DJB_BUILD_ARGS		List of ShellWord
+DJB_BUILD_TARGETS	List of Identifier
+DJB_CONFIG_CMDS		List of ShellWord [o:s]
+# ^^ ShellCommand, terminated by a semicolon
+DJB_CONFIG_DIRS		List of WrksrcSubdirectory
+DJB_CONFIG_HOME		Filename
+DJB_CONFIG_PREFIX	Pathname
+DJB_INSTALL_TARGETS	List of Identifier
+DJB_MAKE_TARGETS	YesNo
+DJB_RESTRICTED		YesNo [m:s]
+DJB_SLASHPACKAGE	YesNo
+DLOPEN_REQUIRE_PTHREADS	YesNo
+DL_AUTO_VARS		Yes [m:s,c:s,o:s]
+DL_LIBS			List of LdFlag
+DOCOWN			UserGroupName [$system]
+DOCGRP			UserGroupName [$system]
+DOCMODE			FileMode [$system]
+DOWNLOADED_DISTFILE	Pathname [$system]
+DO_NADA			ShellCommand [$system]
+DYNAMIC_SITES_CMD	ShellCommand [$package]
+DYNAMIC_SITES_SCRIPT	Pathname [$package]
+ECHO			ShellCommand [$system]
+ECHO_MSG		ShellCommand [$system]
+ECHO_N			ShellCommand [$system]
+EGDIR			Pathname [$package]
+# ^^ This variable is not defined by the system, but has been established
+# as a convention.
+EMACS_BIN		Pathname [$system]
+EMACS_ETCPREFIX		Pathname [$system]
+EMACS_FLAVOR		{ emacs xemacs } [$system]
+EMACS_INFOPREFIX	Pathname [$system]
+EMACS_LISPPREFIX	Pathname [$system]
+EMACS_MODULES		List of Identifier [m:as,c:as]
+EMACS_PKGNAME_PREFIX	Identifier [$system]
+# ^^ or the empty string.
+EMACS_TYPE		{ emacs xemacs } [$system]
+EMACS_USE_LEIM		Yes
+EMACS_VERSIONS_ACCEPTED	List of { emacs25 emacs24 emacs24nox emacs23 emacs23nox emacs22 emacs22nox emacs21 emacs21nox emacs20 xemacs215 xemacs215nox xemacs214 xemacs214nox} [m:s]
+EMACS_VERSION_MAJOR	Integer [$system]
+EMACS_VERSION_MINOR	Integer [$system]
+EMACS_VERSION_REQD	List of { emacs24 emacs24nox emacs23 emacs23nox emacs22 emacs22nox emacs21 emacs21nox emacs20 xemacs215 xemacs214 } [m:as]
+EMULDIR			Pathname [$system]
+EMULSUBDIR		Pathname [$system]
+OPSYS_EMULDIR		Pathname [$system]
+EMULSUBDIRSLASH		Pathname [$system]
+EMUL_ARCH		{ i386 none } [$system]
+EMUL_DISTRO		Identifier [$system]
+EMUL_IS_NATIVE		Yes [$system]
+EMUL_MODULES.*		List of Identifier [$package]
+EMUL_OPSYS		{ freebsd hpux irix linux osf1 solaris sunos none } [$system]
+EMUL_PKG_FMT		{ plain rpm } [$package]
+EMUL_PLATFORM		EmulPlatform [$user]
+EMUL_PLATFORMS		List of EmulPlatform [$package]
+EMUL_PREFER		List of EmulPlatform [$user]
+EMUL_REQD		InternalList of Dependency [$package]
+EMUL_TYPE.*		{ native builtin suse suse-9.1 suse-9.x suse-10.0 suse-10.x } [$user]
+ERROR_CAT		ShellCommand [$system]
+ERROR_MSG		ShellCommand [$system]
+EVAL_PREFIX		InternalList of ShellWord [m:a,c:a]
+# ^^ FIXME: Looks like a type mismatch.
+EXPORT_SYMBOLS_LDFLAGS	List of LdFlag [$system]
+EXTRACT_CMD		ShellCommand [$system]
+EXTRACT_DIR		Pathname [$package]
+EXTRACT_ELEMENTS	List of Pathmask [$package_list]
+EXTRACT_ENV		List of ShellWord [$package_list]
+EXTRACT_ONLY		List of Pathname [$package_list]
+EXTRACT_OPTS		List of ShellWord [m:as,c:as]
+EXTRACT_OPTS_BIN	List of ShellWord [m:as,c:as]
+EXTRACT_OPTS_LHA	List of ShellWord [m:as,c:as]
+EXTRACT_OPTS_PAX	List of ShellWord [m:as,c:as]
+EXTRACT_OPTS_RAR	List of ShellWord [m:as,c:as]
+EXTRACT_OPTS_TAR	List of ShellWord [m:as,c:as]
+EXTRACT_OPTS_ZIP	List of ShellWord [m:as,c:as]
+EXTRACT_OPTS_ZOO	List of ShellWord [m:as,c:as]
+EXTRACT_SUFX		DistSuffix [$package]
+EXTRACT_USING		{ bsdtar gtar nbtar pax } [$package]
+FAIL_MSG		ShellCommand [$system]
+FAMBASE			Pathname [$system]
+FAM_ACCEPTED		List of { fam gamin } [$package]
+FAM_DEFAULT		{ fam gamin } [$user]
+FAM_TYPE		{ fam gamin } [$system]
+FETCH_BEFORE_ARGS	List of ShellWord [m:as]
+FETCH_MESSAGE		List of ShellWord [$package_list]
+FILESDIR		RelativePkgPath [$package]
+FILES_SUBST		List of ShellWord [$package_list]
+FILES_SUBST_SED		List of ShellWord
+FIX_RPATH		List of Varname [$package_list]
+FLEX_REQD		List of Version [$package_list]
+FONTS_DIRS.*		List of Pathname [m:as,c:a]
+GAMEDATAMODE		FileMode [$system]
+GAMES_GROUP		UserGroupName [$system]
+GAMEMODE		FileMode [$system]
+GAMES_USER		UserGroupName [$system]
+GCC_REQD		List of Version [$package_list]
+GENERATE_PLIST		List of ShellWord [$package_list]
+# ^^ List of Shellcommand, terminated with a semicolon
+GITHUB_PROJECT		Identifier [$package]
+GITHUB_TAG		Identifier [$package]
+GITHUB_RELEASE		Filename [$package]
+GITHUB_TYPE		{ tag release } [$package]
+GNU_ARCH		{ mips }
+GNU_CONFIGURE		Yes [c:s,m:s]
+GNU_CONFIGURE_INFODIR	Pathname [m:s,c:s]
+GNU_CONFIGURE_LIBDIR	Pathname [m:s,c:s]
+GNU_CONFIGURE_LIBSUBDIR	Pathname [$package]
+GNU_CONFIGURE_MANDIR	Pathname [m:s,c:s]
+GNU_CONFIGURE_PREFIX	Pathname [m:s]
+HAS_CONFIGURE		Yes [m:s,c:s]
+HEADER_TEMPLATES	List of Pathname [$package_list]
+HOMEPAGE		URL [$package]
+IGNORE_PKG.*		Yes [*:sp]
+INCOMPAT_CURSES		InternalList of PlatformTriple [m:as]
+INCOMPAT_ICONV		InternalList of PlatformTriple
+INFO_DIR		Pathname
+# ^^ relative to PREFIX
+INFO_FILES		Yes [$package]
+INSTALL			ShellCommand [$system]
+INSTALLATION_DIRS	List of PrefixPathname [$package_list]
+INSTALLATION_DIRS_FROM_PLIST	Yes [$package]
+INSTALL_DATA		ShellCommand [$system]
+INSTALL_DATA_DIR	ShellCommand [$system]
+INSTALL_DIRS		List of WrksrcSubdirectory [$package_list]
+INSTALL_ENV		List of ShellWord [$package_list]
+INSTALL_FILE		Pathname [m:s]
+INSTALL_GAME		ShellCommand [$system]
+INSTALL_GAME_DATA	ShellCommand [$system]
+INSTALL_LIB		ShellCommand [$system]
+INSTALL_LIB_DIR		ShellCommand [$system]
+INSTALL_MAKE_FLAGS	List of ShellWord [$package_list]
+INSTALL_MAN		ShellCommand [$system]
+INSTALL_MAN_DIR		ShellCommand [$system]
+INSTALL_PROGRAM		ShellCommand [$system]
+INSTALL_PROGRAM_DIR	ShellCommand [$system]
+INSTALL_SCRIPT		ShellCommand [$system]
+INSTALL_SCRIPTS_ENV	List of ShellWord
+INSTALL_SCRIPT_DIR	ShellCommand [$system]
+INSTALL_SRC		List of Pathname [m:s,c:ds]
+INSTALL_TARGET		List of Identifier [$package]
+INSTALL_TEMPLATES	List of Pathname [m:as,c:ads]
+INSTALL_UNSTRIPPED	YesNo [m:s,c:s]
+INTERACTIVE_STAGE	List of { fetch extract configure build install } [$package]
+IS_BUILTIN.*		YesNo_Indirectly [builtin.mk:psu]
+JAVA_BINPREFIX		Pathname [$system]
+JAVA_CLASSPATH		ShellWord [$package]
+JAVA_HOME		Pathname [$package]
+JAVA_NAME		Filename [$package]
+JAVA_UNLIMIT		List of { cmdsize datasize stacksize } [$package_list]
+JAVA_WRAPPERS		InternalList of Filename [$package_list]
+JAVA_WRAPPER_BIN.*	Pathname [$package]
+KRB5BASE		Pathname [$system]
+KRB5_ACCEPTED		List of { heimdal mit-krb5 }
+KRB5_DEFAULT		{ heimdal mit-krb5 } [$user]
+KRB5_TYPE		Unchecked [$system]
+LD			ShellCommand [$system]
+LDFLAGS*		List of LdFlag [$package_list]
+LIBGRP			UserGroupName [$system]
+LIBMODE			FileMode [$system]
+LIBOWN			UserGroupName [$system]
+LIBOSSAUDIO		Pathname [$system]
+LIBS*			List of LdFlag [$package_list]
+LIBTOOL			ShellCommand [$system]
+LIBTOOL_OVERRIDE	List of Pathmask [m:as]
+LIBTOOL_REQD		List of Version [$package_list]
+LICENCE			License [m:s,c:s,o:s]
+LICENSE			License [m:s,c:s,o:s]
+LICENSE_FILE		Pathname [$package]
+LINKER_RPATH_FLAG	ShellWord [$system]
+LOWER_OPSYS		Identifier [$system]
+LTCONFIG_OVERRIDE	List of Pathmask [m:as,c:a]
+MACHINE_ARCH		Identifier [$system]
+MACHINE_GNU_PLATFORM	PlatformTriple [$system]
+MAINTAINER		Mail_Address [m:s,c:d]
+MAKE			ShellCommand [$system]
+MAKEFLAGS		List of ShellWord [$package_list]
+MAKEVARS		List of Varname [builtin.mk:a,b:a,h:a]
+MAKE_DIRS		List of Pathname [$package_list]
+MAKE_DIRS_PERMS		List of ShellWord [$package_list]
+MAKE_ENV		List of ShellWord [$package_list]
+MAKE_FILE		Pathname [$package]
+MAKE_FLAGS		List of ShellWord [$package_list]
+MAKE_JOBS		Integer [$user]
+MAKE_JOBS_SAFE		YesNo [$package]
+MAKE_PROGRAM		ShellCommand [$package]
+MANCOMPRESSED		YesNo [m:s,c:ds]
+MANCOMPRESSED_IF_MANZ	Yes [m:s,c:ds]
+MANGRP			UserGroupName [$system]
+MANMODE			FileMode [$system]
+MANOWN			UserGroupName [$system]
+MASTER_SITES		List of FetchURL [$package_list]
+MASTER_SITE_APACHE	List of FetchURL [$system]
+MASTER_SITE_BACKUP	List of FetchURL [$system]
+MASTER_SITE_CYGWIN	List of FetchURL [$system]
+MASTER_SITE_DEBIAN	List of FetchURL [$system]
+MASTER_SITE_FREEBSD	List of FetchURL [$system]
+MASTER_SITE_FREEBSD_LOCAL	List of FetchURL [$system]
+MASTER_SITE_GENTOO	List of FetchURL [$system]
+MASTER_SITE_GITHUB	List of FetchURL [$system]
+MASTER_SITE_GNOME	List of FetchURL [$system]
+MASTER_SITE_GNU		List of FetchURL [$system]
+MASTER_SITE_GNUSTEP	List of FetchURL [$system]
+MASTER_SITE_IFARCHIVE	List of FetchURL [$system]
+MASTER_SITE_HASKELL_HACKAGE	List of FetchURL [$system]
+MASTER_SITE_KDE		List of FetchURL [$system]
+MASTER_SITE_LOCAL	List of FetchURL [$system]
+MASTER_SITE_MOZILLA	List of FetchURL [$system]
+MASTER_SITE_MOZILLA_ALL	List of FetchURL [$system]
+MASTER_SITE_MOZILLA_ESR	List of FetchURL [$system]
+MASTER_SITE_MYSQL	List of FetchURL [$system]
+MASTER_SITE_NETLIB	List of FetchURL [$system]
+MASTER_SITE_OPENOFFICE	List of FetchURL [$system]
+MASTER_SITE_OSDN	List of FetchURL [$system]
+MASTER_SITE_PERL_CPAN	List of FetchURL [$system]
+MASTER_SITE_R_CRAN	List of FetchURL [$system]
+MASTER_SITE_RUBYGEMS	List of FetchURL [$system]
+MASTER_SITE_SOURCEFORGE	List of FetchURL [$system]
+MASTER_SITE_SUNSITE	List of FetchURL [$system]
+MASTER_SITE_SUSE	List of FetchURL [$system]
+MASTER_SITE_TEX_CTAN	List of FetchURL [$system]
+MASTER_SITE_XCONTRIB	List of FetchURL [$system]
+MASTER_SITE_XEMACS	List of FetchURL [$system]
+MESSAGE_SRC		List of Pathname [$package_list]
+MESSAGE_SUBST		List of ShellWord [c:a,m:a,o:a]
+META_PACKAGE		Yes [$package]
+MISSING_FEATURES	List of Identifier [$system]
+MYSQL_VERSIONS_ACCEPTED	List of { 51 55 56 } [m:s]
+MYSQL_VERSION_DEFAULT	Version [$user]
+NM			ShellCommand [$system]
+NONBINMODE		FileMode [$system]
+NOT_FOR_COMPILER	List of { ccache ccc clang distcc f2c gcc hp icc ido mipspro mipspro-ucode pcc sunpro xlc } [$package]
+NOT_FOR_PLATFORM	InternalList of PlatformTriple [$package_list]
+NOT_FOR_UNPRIVILEGED	YesNo [$package]
+NO_BIN_ON_CDROM		Restricted [m:s,c:s]
+NO_BIN_ON_FTP		Restricted [m:s,c:s]
+NO_BUILD		Yes [m:s,c:s,Makefile.*:ds]
+NO_CHECKSUM		Yes [$package]
+NO_CONFIGURE		Yes [$package]
+NO_EXPORT_CPP		Yes [m:s]
+NO_EXTRACT		Yes [$package]
+NO_INSTALL_MANPAGES	Yes [$package]
+# ^^ only has an effect for Imake packages.
+NO_PKGTOOLS_REQD_CHECK	Yes [m:s]
+NO_SRC_ON_CDROM		Restricted [m:s,c:s]
+NO_SRC_ON_FTP		Restricted [m:s,c:s]
+ONLY_FOR_COMPILER	List of { ccc clang gcc hp icc ido mipspro mipspro-ucode pcc sunpro xlc } [$package_list]
+ONLY_FOR_PLATFORM	InternalList of PlatformTriple [$package_list]
+ONLY_FOR_UNPRIVILEGED	YesNo [$package]
+OPSYS			Identifier [$system]
+OPSYSVARS		List of Varname [m:a,c:a]
+OSVERSION_SPECIFIC	Yes [m:s,c:s]
+OS_VERSION		Version [$system]
+OVERRIDE_DIRDEPTH*	Integer [$package]
+OVERRIDE_GNU_CONFIG_SCRIPTS	Yes [$package]
+OWNER			Mail_Address [m:s,c:d]
+OWN_DIRS		List of Pathname [$package_list]
+OWN_DIRS_PERMS		List of ShellWord [$package_list]
+PAMBASE			Pathname [$system]
+PAM_DEFAULT		{ linux-pam openpam solaris-pam } [$user]
+PATCHDIR		RelativePkgPath [m:s,c:ds]
+PATCHFILES		List of Filename [$package_list]
+PATCH_ARGS		List of ShellWord
+PATCH_DIST_ARGS		List of ShellWord [m:as]
+PATCH_DIST_CAT		ShellCommand
+PATCH_DIST_STRIP*	ShellWord [m:s, c:s, b:, builtin.mk:, *.mk:s]
+PATCH_SITES		List of URL [m:s,o:s,c:s]
+PATCH_STRIP		ShellWord
+PERL5_USE_PACKLIST	YesNo [$package]
+PERL5_PACKLIST		List of Perl5Packlist [m:s,o:sa]
+PERL5_PACKLIST_DIR	Pathname []
+PGSQL_PREFIX		Pathname [$system]
+PGSQL_VERSIONS_ACCEPTED	List of { 91 92 93 94}
+PGSQL_VERSION_DEFAULT	Version [$user]
+PG_LIB_EXT		{ dylib so } [$system]
+PGSQL_TYPE		{ postgresql81-client postgresql80-client } [$system]
+PGPKGSRCDIR		Pathname [$system]
+PHASE_MSG		ShellCommand [$system]
+PHP_VERSION_REQD	Version [$user]
+PKGBASE			Identifier [$system]
+PKGCONFIG_OVERRIDE	List of Pathmask [m:as,c:a]
+PKGCONFIG_OVERRIDE_STAGE	Stage [$package]
+PKGDIR			RelativePkgDir [$package]
+PKGDIRMODE		FileMode [$system]
+PKGLOCALEDIR		Pathname [$system]
+PKGNAME			PkgName [$package]
+PKGNAME_NOREV		PkgName [$system]
+PKGPATH			Pathname [$system]
+PKGREPOSITORY		Unchecked []
+PKGREVISION		PkgRevision [m:s]
+PKGSRCDIR		Pathname [$system]
+PKGSRCTOP		Yes [m:s]
+PKGTOOLS_ENV		List of ShellWord
+PKGVERSION		Version [$system]
+PKGWILDCARD		Filemask [$system]
+PKG_ADMIN		ShellCommand [$system]
+PKG_APACHE		{ apache22 apache24 } [$system]
+PKG_APACHE_ACCEPTED	List of { apache22 apache24 } [$package]
+PKG_APACHE_DEFAULT	{ apache22 apache24 } [$user]
+PKG_CONFIG		Yes [$user]
+# ^^ No, this is not the popular command from GNOME, but the setting
+# whether the pkgsrc user wants configuration files automatically
+# installed or not.
+PKG_CREATE		ShellCommand [$system]
+PKG_DBDIR		Pathname [$system]
+PKG_DEBUG_LEVEL		Integer [$cmdline]
+PKG_DEFAULT_OPTIONS	List of Option [$user]
+PKG_DELETE		ShellCommand [$system]
+PKG_DESTDIR_SUPPORT	List of { destdir user-destdir } [m:s,c:s]
+PKG_FAIL_REASON		List of ShellWord [$package_list]
+PKG_GECOS.*		Message [m:s]
+PKG_GID.*		Integer [m:s]
+PKG_GROUPS		List of ShellWord [m:as]
+PKG_GROUPS_VARS		List of Varname [$package_list]
+PKG_HOME.*		Pathname [m:s]
+PKG_HACKS		List of Identifier [h:a]
+PKG_INFO		ShellCommand [$system]
+PKG_JAVA_HOME		Pathname [$system]
+PKG_JVM			{						\
+				blackdown-jdk13				\
+				jdk jdk14				\
+				kaffe					\
+				sun-jdk13 sun-jdk14 sun-jdk15 sun-jdk6	\
+				openjdk7 openjdk7-bin sun-jdk7		\
+			} [$system]
+PKG_JVMS_ACCEPTED	List of {					\
+				blackdown-jdk13				\
+				jdk jdk14				\
+				kaffe					\
+				sun-jdk13 sun-jdk14 sun-jdk15 sun-jdk6	\
+				openjdk7 openjdk7-bin sun-jdk7		\
+			} [m:s,c:ds]
+PKG_JVM_DEFAULT		{						\
+				blackdown-jdk13				\
+				jdk jdk14				\
+				kaffe					\
+				sun-jdk13 sun-jdk14 sun-jdk15 sun-jdk6	\
+				openjdk7 openjdk7-bin sun-jdk7		\
+			} [$user]
+PKG_LEGACY_OPTIONS	List of Option
+PKG_LIBTOOL		Pathname [m:s]
+PKG_OPTIONS		InternalList of Option [bsd.options.mk:s,*:pu]
+PKG_OPTIONS.*		InternalList of Option [$user]
+PKG_OPTIONS_DEPRECATED_WARNINGS	List of ShellWord
+PKG_OPTIONS_GROUP.*	InternalList of Option [o:s,m:s]
+PKG_OPTIONS_LEGACY_OPTS	InternalList of Unchecked [m:a,c:a,o:a]
+PKG_OPTIONS_LEGACY_VARS	InternalList of Unchecked [m:a,c:a,o:a]
+PKG_OPTIONS_NONEMPTY_SETS	InternalList of Identifier
+PKG_OPTIONS_OPTIONAL_GROUPS	InternalList of Identifier [o:as]
+PKG_OPTIONS_REQUIRED_GROUPS	InternalList of Identifier [o:s,m:s]
+PKG_OPTIONS_SET.*	InternalList of Option
+PKG_OPTIONS_VAR		PkgOptionsVar [o:s,m:s,c:s, bsd.options.mk:p]
+PKG_PRESERVE		Yes [m:s]
+PKG_SHELL		Pathname [m:s,c:s]
+PKG_SHELL.*		Pathname [m:s,c:s]
+PKG_SHLIBTOOL		Pathname
+PKG_SKIP_REASON		List of ShellWord [$package_list]
+PKG_SUGGESTED_OPTIONS	List of Option [o:as,m:as,c:s]
+PKG_SUPPORTED_OPTIONS	List of Option [o:as,m:as,c:s]
+PKG_SYSCONFDIR*		Pathname [$package]
+PKG_SYSCONFDIR_PERMS	List of ShellWord [$package_list]
+PKG_SYSCONFBASEDIR	Pathname [$system]
+PKG_SYSCONFSUBDIR	Pathname [$package]
+PKG_SYSCONFVAR		Identifier
+# ^^ FIXME: name/type mismatch.
+PKG_UID			Integer [m:s]
+PKG_USERS		List of ShellWord [m:as]
+PKG_USERS_VARS		List of Varname [$package]
+PKG_USE_KERBEROS	Yes [m:s,c:s]
+#PLIST.*		# has special handling code
+PLIST_VARS		List of Identifier [$package_list]
+PLIST_SRC		List of RelativePkgPath [$package_list]
+PLIST_SUBST		List of ShellWord [$package_list]
+PLIST_TYPE		{ dynamic static }
+PREPEND_PATH		List of Pathname
+PREFIX			Pathname [*:u]			# ???
+PREV_PKGPATH		Pathname [*:u]	# doesn't exist any longer
+PRINT_PLIST_AWK		AwkCommand [*:a]
+PRIVILEGED_STAGES	List of { install package clean }
+PTHREAD_AUTO_VARS	YesNo [m:s]
+PTHREAD_CFLAGS		List of CFlag [$system]
+PTHREAD_LDFLAGS		List of LdFlag [$system]
+PTHREAD_LIBS		List of LdFlag [$system]
+PTHREAD_OPTS		List of { native optional require } [m:as,c:a,b:a]
+PTHREAD_TYPE		Identifier [$system]
+# ^^ or "native" or "none".
+PY_PATCHPLIST		Yes [$package]
+PYPKGPREFIX		{ py27 py33 py34 } [*:pu, pyversion.mk:s, *:]
+PYTHON_FOR_BUILD_ONLY	Yes [$package]
+REPLACE_PYTHON	List of Pathmask [$package_list]
+PYTHON_VERSIONS_ACCEPTED List of Version [$package]
+PYTHON_VERSIONS_INCOMPATIBLE List of Version [$package]
+PYTHON_VERSION_DEFAULT	Version [$user]
+PYTHON_VERSION_REQD	Version [$user]
+PYTHON_VERSIONED_DEPENDENCIES	List of PythonDependency [$package_list]
+RANLIB			ShellCommand [$system]
+RCD_SCRIPTS		List of Filename [$package_list]
+RCD_SCRIPT_SRC.*	List of Pathname [m:s]
+REPLACE.*		String [m:s]
+REPLACE_AWK		List of Pathmask [$package_list]
+REPLACE_BASH		List of Pathmask [$package_list]
+REPLACE_CSH		List of Pathmask [$package_list]
+REPLACE_EMACS		List of Pathmask
+REPLACE_FILES.*		List of Pathmask [m:as,c:as]
+REPLACE_INTERPRETER	List of Identifier [m:a,c:a]
+REPLACE_KSH		List of Pathmask [$package_list]
+REPLACE_LOCALEDIR_PATTERNS	List of Filemask [$package_list]
+REPLACE_LUA		List of Pathmask [$package_list]
+REPLACE_PERL		List of Pathmask [$package_list]
+REPLACE_PYTHON		List of Pathmask [$package_list]
+REPLACE_SH		List of Pathmask [$package_list]
+REQD_DIRS		List of Pathname [$package_list]
+REQD_DIRS_PERMS		List of ShellWord [$package_list]
+REQD_FILES		List of Pathname [$package_list]
+REQD_FILES_MODE		{ 0644 0640 0600 0400 } [$package]
+REQD_FILES_PERMS	List of ShellWord [$package_list]
+RESTRICTED		Message [$package]
+ROOT_USER		UserGroupName [$user]
+ROOT_GROUP		UserGroupName [$user]
+RUBY_VERSION_REQD	Version [$user]
+RUN			ShellCommand [$system]
+SCRIPTS_ENV		List of ShellWord [m:a,c:a]
+SETUID_ROOT_PERMS	List of ShellWord [$user]
+SHAREGRP		UserGroupName [$system]
+SHAREMODE		FileMode [$system]
+SHAREOWN		UserGroupName [$system]
+SHCOMMENT		ShellCommand [$system]
+SHLIB_HANDLING		{ YES NO no }
+SHLIBTOOL		ShellCommand []
+SHLIBTOOL_OVERRIDE	List of Pathmask [m:as,c:a]
+SITES.*			List of FetchURL [m:asu,c:asu,o:asu]
+SPECIAL_PERMS		List of ShellWord [$package_list]
+STEP_MSG		ShellCommand [$system]
+SUBDIR			List of Filename [Makefile:a,*:]
+SUBST_CLASSES		List of Identifier [m:a,c:a,h:a,Makefile.*:a]
+SUBST_FILES.*		List of Pathmask [m:as,c:as,h:as,o:as,Makefile.*:as]
+SUBST_FILTER_CMD.*	ShellCommand [m:s,c:s,h:s,o:s,Makefile.*:s]
+SUBST_MESSAGE.*		Message [m:s,c:s,h:s,o:s,Makefile.*:s]
+SUBST_SED.*		SedCommands [m:as,c:as,h:as,o:as,Makefile.*:as]
+SUBST_STAGE.*		Stage [$package]
+SUBST_VARS.*		List of Varname [$package_list]
+SUPERSEDES		InternalList of Dependency [$package_list]
+TEST_DIRS		List of WrksrcSubdirectory [$package_list]
+TEST_ENV		List of ShellWord [$package_list]
+TEST_TARGET		List of Identifier [m:s,c:ds,o:as]
+TEX_ACCEPTED		List of { teTeX1 teTeX2 teTeX3 } [m:s,c:s]
+TEX_DEPMETHOD		{ build run } [m:s,c:s]
+TEXINFO_REQD		List of Version [$package_list]
+TOOL_DEPENDS		InternalList of DependencyWithPath [c:a,m:a,o:a,*.mk:a]
+TOOLS_ALIASES		List of Filename [$system]
+TOOLS_BROKEN		List of Tool [$system]
+TOOLS_CREATE		List of Tool [$system]
+TOOLS_DEPENDS.*		InternalList of DependencyWithPath [$system]
+TOOLS_GNU_MISSING	List of Tool [$system]
+TOOLS_NOOP		List of Tool [$system]
+TOOLS_PATH.*		Pathname [$system]
+TOOLS_PLATFORM.*	ShellCommand [$system]
+TOUCH_FLAGS		List of ShellWord [$system]
+UAC_REQD_EXECS		List of PrefixPathname [$package_list]
+UNLIMIT_RESOURCES	List of { datasize stacksize memorysize } [m:as,c:a]
+UNPRIVILEGED_USER	UserGroupName [$user]
+UNPRIVILEGED_GROUP	UserGroupName [$user]
+UNWRAP_FILES		List of Pathmask [$package_list]
+UPDATE_TARGET		List of Identifier [$user]
+USE_BSD_MAKEFILE	Yes [$package]
+USE_BUILTIN.*		YesNo_Indirectly [builtin.mk:s]
+USE_CMAKE		Yes [$package]
+USE_CROSSBASE		Yes [m:s]
+USE_FEATURES		List of Identifier [$package]
+USE_GCC_RUNTIME		YesNo [$package]
+USE_GNU_CONFIGURE_HOST	YesNo [$package]
+USE_GNU_ICONV		Yes [m:s,c:s,o:s]
+USE_IMAKE		Yes [m:s]
+USE_JAVA		{ run yes build } [$package]
+USE_JAVA2		{ YES yes no 1.4 1.5 6 7 8 } [$package]
+USE_LANGUAGES		List of { ada c c99 c++ fortran fortran77 java objc } [m:s,c:s,o:s]
+USE_LIBTOOL		Yes [$package]
+USE_MAKEINFO		Yes [$package]
+USE_MSGFMT_PLURALS	Yes [$package]
+USE_NCURSES		Yes [$package]
+USE_OLD_DES_API		YesNo [$package]
+USE_PKGINSTALL		Yes [$package]
+USE_PKGLOCALEDIR	YesNo [$package]
+USE_PKGSRC_GCC		Yes [$user]
+USE_TOOLS		List of Tool [*:a]
+USE_X11			Yes [$package]
+WARNING_MSG		ShellCommand [$system]
+WARNING_CAT		ShellCommand [$system]
+WRAPPER_REORDER_CMDS	List of WrapperReorder [b:a,c:a,m:a]
+WRAPPER_TRANSFORM_CMDS	List of WrapperTransform [b:a,c:a,m:a]
+WRKDIR			Pathname [$system]
+WRKSRC			WrkdirSubdirectory [$package]
+X11_PKGSRCDIR.*		Pathname [$system]
+XAW_TYPE		{ 3d neXtaw standard xpm } [$user]
+XMKMF_FLAGS		List of ShellWord
diff --git a/pkgtools/pkglint4/files/pkglint.0 b/pkgtools/pkglint4/files/pkglint.0
new file mode 100644
index 00000000000..d814bdaf4e6
--- /dev/null
+++ b/pkgtools/pkglint4/files/pkglint.0
@@ -0,0 +1,213 @@
+PKGLINT(1)                  General Commands Manual                 PKGLINT(1)
+
+NNAAMMEE
+     ppkkgglliinntt -- static analyzer for pkgsrc packages
+
+SSYYNNOOPPSSIISS
+     ppkkgglliinntt [--ooppttiioonnss] [_d_i_r _._._.]
+
+DDEESSCCRRIIPPTTIIOONN
+     ppkkgglliinntt attempts to detect features of the named pkgsrc packages that are
+     likely to be bugs, or that are simply deprecated.
+
+
+   OOppttiioonnss
+     --CC{{[[nnoo--]]cchheecckk,,......}}  Enable or disable specific checks.  For a list of
+                         checks, see below.
+
+     --DD{{[[nnoo--]]ddeebbuugg,,......}}  Enable or disable debugging categories.  For a list
+                         of categories, see below.
+
+     --FF|----aauuttooffiixx        Repair trivial things automatically.
+
+     --II                  Show the _M_a_k_e_f_i_l_e that is constructed by including
+                         all the files that are slurped in via `.include'
+                         directives.  This flag is mainly for debugging.
+
+     --RR|----rrccssiiddssttrriinngg    Allow other RCS Id strings than NetBSD.  Multiple
+                         strings may be concatenated with `|'.
+
+     --VV|----vveerrssiioonn        Print the current ppkkgglliinntt version number and exit.
+
+     --WW{{[[nnoo--]]wwaarrnn,,......}}   Enable or disable specific warnings.  For a list of
+                         warnings, see below.
+
+     --ee|----eexxppllaaiinn        Print further explanations for diagnostics.
+                         Sometimes the reasons for diagnostics are not obvious
+                         and need further explanation.
+
+     --gg|----ggcccc--oouuttppuutt--ffoorrmmaatt
+                         Use a format for the diagnostics that is understood
+                         by most programs, especially editors, so they can
+                         provide a point-and-goto interface.
+
+     --hh|----hheellpp           Show the summary of command line options, then exit.
+
+     --ii|----iimmppoorrtt         Check if a package is ready to be imported into
+                         pkgsrc.  This is especially useful for packages from
+                         the pkgsrc-wip project.
+
+     --qq|----qquuiieett          Don't print the errors and warnings summary before
+                         terminating.
+
+     --rr|----rreeccuurrssiivvee      Check subdirectories, too.  The subdirectories are
+                         those that are mentioned in a `SUBDIR+=' line.
+
+     --ss|----ssoouurrccee         For all diagnostics having file and line number
+                         information, show the source code along with the
+                         diagnostics.
+
+   CChheecckkss
+     aallll                 Enable all checks.
+
+     nnoonnee                Disable all checks.
+
+     [[nnoo--]]AALLTTEERRNNAATTIIVVEESS   Check the alternatives file.
+
+     [[nnoo--]]DDEESSCCRR          Check the DESCR file.
+
+     [[nnoo--]]IINNSSTTAALLLL        Check the INSTALL and DEINSTALL scripts.
+
+     [[nnoo--]]MMaakkeeffiillee       Check the package Makefile, including all included
+                         files.
+
+     [[nnoo--]]MMEESSSSAAGGEE        Check MESSAGE files.
+
+     [[nnoo--]]PPLLIISSTT          Check PLIST files.
+
+     [[nnoo--]]bbll33            Check buildlink3 Makefiles.
+
+     [[nnoo--]]ddiissttiinnffoo       Check the distinfo file.
+
+     [[nnoo--]]eexxttrraa          Check remaining files in the package directory.
+
+     [[nnoo--]]mmkk             Check Makefile fragments besides buildlink3.
+
+     [[nnoo--]]ppaattcchheess        Check the pkgsrc specific patch files.
+
+   DDeebbuuggggiinngg OOppttiioonnss
+     aallll                 Enable all debugging options.
+
+     nnoonnee                Disable all debugging options.
+
+     [[nnoo--]]iinncclluuddee        Show the pathnames of the included Makefiles.
+
+     [[nnoo--]]mmiisscc           Some debugging stuff that hasn't made it into its own
+                         category.
+
+     [[nnoo--]]ppaattcchheess        Print the states of the patch file parser.
+
+     [[nnoo--]]qquuoottiinngg        Additional information about why variables should be
+                         quoted or not.
+
+     [[nnoo--]]sshheellll          Parser information from the shell word and the shell
+                         command parsers.
+
+     [[nnoo--]]ttoooollss          Additional information about the tools from the tools
+                         framework.
+
+     [[nnoo--]]ttrraaccee          Print the names of subroutines and their arguments as
+                         they are entered.
+
+     [[nnoo--]]uunncchheecckkeedd      Show the things that pkglint cannot currently check.
+                         These are mostly due to unresolved make variables.
+
+     [[nnoo--]]uunnuusseedd         Show which variables are detected as used, and so
+                         will not generate an ``unused variable'' warning.
+
+     [[nnoo--]]vvaarrttyyppeess       Additional information about the variable types.
+
+     [[nnoo--]]vvaarruussee         Information about the contexts in which variables are
+                         used.
+
+   WWaarrnniinnggss
+     aallll                 Enable all warnings.
+
+     nnoonnee                Disable all warnings.
+
+     [[nnoo--]]aabbssnnaammee        Warn if a file contains an absolute pathname.
+
+     [[nnoo--]]ddiirreeccttccmmdd      Warn if a system command name is used instead of a
+                         variable (e.g. sed instead of ${SED}).
+
+     [[nnoo--]]eexxttrraa          Emit some additional warnings that are not enabled by
+                         default, for whatever reason.
+
+     [[nnoo--]]oorrddeerr          Warn if Makefile variables are not in the preferred
+                         order.
+
+     [[nnoo--]]ppeerrmm           Warn if a variable is used or defined outside its
+                         specified scope.  The available permissions are:
+                         append
+                              append something using +=
+                         default
+                              set a default value using ?=
+                         preprocess
+                              use a variable during preprocessing
+                         runtime
+                              use a variable at runtime
+                         set  set a variable using :=, =, !=
+                         unknown
+                              permissions for this variable currently not
+                              known
+                         A `?' means that it is not yet clear which
+                         permissions are allowed and which aren't.
+
+     [[nnoo--]]pplliisstt--ddeepprr     Warn if deprecated pathnames are used in _P_L_I_S_T files.
+                         This warning is disabled by default.
+
+     [[nnoo--]]pplliisstt--ssoorrtt     Warn if items of a PLIST file are not sorted
+                         alphabetically.  This warning is disabled by default.
+
+     [[nnoo--]]qquuoottiinngg        Warn for possibly invalid quoting of make variables
+                         in shell programs and shell variables themselves.
+
+     [[nnoo--]]ssppaaccee          Emit notes for inconsistent use of white-space.
+
+     [[nnoo--]]ssttyyllee          Warn for stylistic issues that don't affect the build
+                         process.
+
+     [[nnoo--]]ttyyppeess          Warn for some _M_a_k_e_f_i_l_e variables if their assigned
+                         values do not match their type.
+
+     [[nnoo--]]vvaarroorrddeerr       Warn if the variables in a package _M_a_k_e_f_i_l_es are not
+                         ordered in the way it is described the pkgsrc guide.
+
+   OOtthheerr aarrgguummeennttss
+           _d_i_r _._._.             The pkgsrc directories to be checked.  If
+                               omitted, the current directory is checked.
+
+FFIILLEESS
+     _p_k_g_s_r_c_/_m_k_/_*  Files from the pkgsrc infrastructure.
+
+EEXXAAMMPPLLEESS
+     ppkkgglliinntt --CCnnoonnee,,ppaattcchheess ..
+                 Checks the patches of the package in the current directory.
+
+     ppkkgglliinntt --WWaallll //uussrr//ppkkggssrrcc//ddeevveell
+                 Checks the category Makefile and reports any warnings it can
+                 find.
+
+     ppkkgglliinntt --rr --RR ''NNeettBBSSDD||IIdd'' //uussrr//ppkkggssrrcc
+                 Check the whole pkgsrc tree while allowing `NetBSD' or `Id'
+                 as the RCS Id.
+
+DDIIAAGGNNOOSSTTIICCSS
+     Diagnostics are written to the standard output.
+
+     ERROR: ...    Errors should be fixed before a package is committed to
+                   pkgsrc.
+
+     WARN: ...     Warnings generally should be fixed, but they are not as
+                   critical as errors.
+
+AAUUTTHHOORRSS
+     Roland Illig <rillig@NetBSD.org>
+
+BBUUGGSS
+     Many more checks could be added.
+
+     If you don't understand the messages, feel free to ask on the
+     <tech-pkg@NetBSD.org> mailing list.
+
+NetBSD 6.99.8                    July 14, 2012                   NetBSD 6.99.8
diff --git a/pkgtools/pkglint4/files/pkglint.1 b/pkgtools/pkglint4/files/pkglint.1
new file mode 100644
index 00000000000..811746f41b9
--- /dev/null
+++ b/pkgtools/pkglint4/files/pkglint.1
@@ -0,0 +1,244 @@
+.\"	$NetBSD: pkglint.1,v 1.1 2015/11/25 16:42:21 rillig Exp $
+.\"	From FreeBSD: portlint.1,v 1.8 1997/11/25 14:53:14 itojun Exp
+.\"
+.\" Copyright (c) 1997 by Jun-ichiro Itoh <itojun@itojun.org>.
+.\" All Rights Reserved.  Absolutely no warranty.
+.\"
+.\" Roland Illig <roland.illig@gmx.de>, 2004, 2005.
+.\" Thomas Klausner <wiz@NetBSD.org>, 2012.
+.\"
+.Dd July 14, 2012
+.Dt PKGLINT 1
+.Os
+.Sh NAME
+.Nm pkglint
+.Nd static analyzer for pkgsrc packages
+.Sh SYNOPSIS
+.Nm pkglint
+.Op Fl options
+.Op Ar dir ...
+.Sh DESCRIPTION
+.Nm
+attempts to detect features of the named pkgsrc packages that are likely
+to be bugs, or that are simply deprecated.
+.Pp
+.\" =======================================================================
+.Ss Options
+.Bl -tag -width 18n
+.It Fl C{[no-]check,...}
+Enable or disable specific checks.
+For a list of checks, see below.
+.It Fl D{[no-]debug,...}
+Enable or disable debugging categories.
+For a list of categories, see below.
+.It Fl F Ns | Ns Fl -autofix
+Repair trivial things automatically.
+.It Fl I
+Show the
+.Pa Makefile
+that is constructed by including all the files that
+are slurped in via
+.Ql .include
+directives.
+This flag is mainly for debugging.
+.It Fl R Ns | Ns Fl -rcsidstring
+Allow other RCS Id strings than NetBSD.
+Multiple strings may be concatenated with
+.Ql | .
+.It Fl V Ns | Ns Fl -version
+Print the current
+.Nm
+version number and exit.
+.It Fl W{[no-]warn,...}
+Enable or disable specific warnings.
+For a list of warnings, see below.
+.It Fl e Ns | Ns Fl -explain
+Print further explanations for diagnostics.
+Sometimes the reasons for diagnostics are not obvious and need further
+explanation.
+.It Fl g Ns | Ns Fl -gcc-output-format
+Use a format for the diagnostics that is understood by most programs,
+especially editors, so they can provide a point-and-goto interface.
+.It Fl h Ns | Ns Fl -help
+Show the summary of command line options, then exit.
+.It Fl i Ns | Ns Fl -import
+Check if a package is ready to be imported into pkgsrc.
+This is especially useful for packages from the pkgsrc-wip project.
+.It Fl q Ns | Ns Fl -quiet
+Don't print the errors and warnings summary before terminating.
+.It Fl r Ns | Ns Fl -recursive
+Check subdirectories, too.
+The subdirectories are those that are mentioned in a
+.Ql SUBDIR+=
+line.
+.It Fl s Ns | Ns Fl -source
+For all diagnostics having file and line number information, show the
+source code along with the diagnostics.
+.El
+.\" =======================================================================
+.Ss Checks
+.Bl -tag -width 18n
+.It Cm all
+Enable all checks.
+.It Cm none
+Disable all checks.
+.It Cm [no-]ALTERNATIVES
+Check the alternatives file.
+.It Cm [no-]DESCR
+Check the DESCR file.
+.It Cm [no-]INSTALL
+Check the INSTALL and DEINSTALL scripts.
+.It Cm [no-]Makefile
+Check the package Makefile, including all included files.
+.It Cm [no-]MESSAGE
+Check MESSAGE files.
+.It Cm [no-]PLIST
+Check PLIST files.
+.It Cm [no-]bl3
+Check buildlink3 Makefiles.
+.It Cm [no-]distinfo
+Check the distinfo file.
+.It Cm [no-]extra
+Check remaining files in the package directory.
+.It Cm [no-]mk
+Check Makefile fragments besides buildlink3.
+.It Cm [no-]patches
+Check the pkgsrc specific patch files.
+.El
+.\" =======================================================================
+.Ss Debugging Options
+.Bl -tag -width 18n
+.It Cm all
+Enable all debugging options.
+.It Cm none
+Disable all debugging options.
+.It Cm [no-]include
+Show the pathnames of the included Makefiles.
+.It Cm [no-]misc
+Some debugging stuff that hasn't made it into its own category.
+.It Cm [no-]patches
+Print the states of the patch file parser.
+.It Cm [no-]quoting
+Additional information about why variables should be quoted or not.
+.It Cm [no-]shell
+Parser information from the shell word and the shell command parsers.
+.It Cm [no-]tools
+Additional information about the tools from the tools framework.
+.It Cm [no-]trace
+Print the names of subroutines and their arguments as they are entered.
+.It Cm [no-]unchecked
+Show the things that pkglint cannot currently check.
+These are mostly due to unresolved make variables.
+.It Cm [no-]unused
+Show which variables are detected as used, and so will not generate an
+.Dq unused variable
+warning.
+.It Cm [no-]vartypes
+Additional information about the variable types.
+.It Cm [no-]varuse
+Information about the contexts in which variables are used.
+.El
+.\" =======================================================================
+.Ss Warnings
+.Bl -tag -width 18n
+.It Cm all
+Enable all warnings.
+.It Cm none
+Disable all warnings.
+.It Cm [no-]absname
+Warn if a file contains an absolute pathname.
+.It Cm [no-]directcmd
+Warn if a system command name is used instead of a variable (e.g. sed
+instead of ${SED}).
+.It Cm [no-]extra
+Emit some additional warnings that are not enabled by default,
+for whatever reason.
+.It Cm [no-]order
+Warn if Makefile variables are not in the preferred order.
+.It Cm [no-]perm
+Warn if a variable is used or defined outside its specified scope.
+The available permissions are:
+.Bl -tag -width 3n -compact
+.It append
+append something using +=
+.It default
+set a default value using ?=
+.It preprocess
+use a variable during preprocessing
+.It runtime
+use a variable at runtime
+.It set
+set a variable using :=, =, !=
+.It unknown
+permissions for this variable currently not known
+.El
+A
+.Sq \&?
+means that it is not yet clear which permissions are allowed and which aren't.
+.It Cm [no-]plist-depr
+Warn if deprecated pathnames are used in
+.Pa PLIST
+files.
+This warning is disabled by default.
+.It Cm [no-]plist-sort
+Warn if items of a PLIST file are not sorted alphabetically.
+This warning is disabled by default.
+.It Cm [no-]quoting
+Warn for possibly invalid quoting of make variables in shell programs
+and shell variables themselves.
+.It Cm [no-]space
+Emit notes for inconsistent use of white-space.
+.It Cm [no-]style
+Warn for stylistic issues that don't affect the build process.
+.It Cm [no-]types
+Warn for some
+.Pa Makefile
+variables if their assigned values do not match
+their type.
+.It Cm [no-]varorder
+Warn if the variables in a package
+.Pa Makefile Ns
+s are not ordered in the way it is described the pkgsrc guide.
+.El
+.\" =======================================================================
+.Ss Other arguments
+.Bl -tag -width 18n -offset indent
+.It Ar dir ...
+The pkgsrc directories to be checked.
+If omitted, the current directory is checked.
+.El
+.Sh FILES
+.Bl -tag -width pkgsrc/mk/* -compact
+.It Pa pkgsrc/mk/*
+Files from the pkgsrc infrastructure.
+.El
+.Sh EXAMPLES
+.Bl -tag -width Fl
+.It Ic pkglint \-Cnone,patches \&.
+Checks the patches of the package in the current directory.
+.It Ic pkglint \-Wall /usr/pkgsrc/devel
+Checks the category Makefile and reports any warnings it can find.
+.It Ic pkglint -r \-R 'NetBSD|Id' /usr/pkgsrc
+Check the whole pkgsrc tree while allowing
+.Ql NetBSD
+or
+.Ql Id
+as the RCS Id.
+.El
+.Sh DIAGNOSTICS
+Diagnostics are written to the standard output.
+.Bl -tag -width "WARN: foobaa"
+.It ERROR: ...
+Errors should be fixed before a package is committed to pkgsrc.
+.It WARN: ...
+Warnings generally should be fixed, but they are not as critical as
+errors.
+.El
+.Sh AUTHORS
+.An Roland Illig Aq Mt rillig@NetBSD.org
+.Sh BUGS
+Many more checks could be added.
+.Pp
+If you don't understand the messages, feel free to ask on the
+.Aq tech-pkg@NetBSD.org
+mailing list.
diff --git a/pkgtools/pkglint4/files/pkglint.pl b/pkgtools/pkglint4/files/pkglint.pl
new file mode 100644
index 00000000000..ddb6c1f8c48
--- /dev/null
+++ b/pkgtools/pkglint4/files/pkglint.pl
@@ -0,0 +1,5915 @@
+#! @PERL@
+# $NetBSD: pkglint.pl,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+
+# pkglint - static analyzer and checker for pkgsrc packages
+#
+# Written by:
+#	Roland Illig <rillig@NetBSD.org>
+#
+# Based on work by:
+#	Hubert Feyrer <hubertf@NetBSD.org>
+#	Thorsten Frueauf <frueauf@NetBSD.org>
+#	Thomas Klausner <wiz@NetBSD.org>
+#	and others.
+#
+# Based on FreeBSD's portlint by:
+#	Jun-ichiro itojun Hagino <itojun@itojun.org>
+#	Yoshishige Arai <ryo2@on.rim.or.jp>
+#
+#	FreeBSD Id: portlint.pl,v 1.64 1998/02/28 02:34:05 itojun Exp
+#	Copyright(c) 1997 by Jun-ichiro Hagino <itojun@itojun.org>.
+#	All rights reserved.
+#	Freely redistributable.  Absolutely no warranty.
+
+# To get an overview of the code, run:
+#    sed -n -e 's,^\(sub .*\) {.*,  \1,p' -e '/^package/p' pkglint.pl
+
+#==========================================================================
+# Note: The @EXPORT clauses in the packages must be in a BEGIN block,
+# because otherwise the names starting with an uppercase letter are not
+# recognized as subroutines but as file handles.
+#==========================================================================
+
+use v5.12;
+use warnings;
+
+#include PkgLint/Util.pm
+#include PkgLint/Logging.pm
+#include PkgLint/SimpleMatch.pm
+#include PkgLint/Line.pm
+#include PkgLint/FileUtil.pm
+#include PkgLint/Type.pm
+#include PkgLint/VarUseContext.pm
+#include PkgLint/SubstContext.pm
+#include PkgLint/CVS_Entry.pm
+#include PkgLint/Change.pm
+
+package pkglint;
+#==========================================================================
+# This package contains the application-specific code of pkglint.
+# Most subroutines in this package follow a strict naming convention:
+#
+# The get_*() functions provide easy access to important non-trivial data
+# structures that are loaded from external files and are therefore cached.
+#
+# The is_*() functions return a boolean value and have no side effects.
+#
+# The checkline_*() procedures check a single line for compliance with some
+# rules.
+#
+# The checklines_*() procedures check an array of lines for compliance.
+# Usually they make use of several checkline_*() procedures.
+#
+# The checkfile_*() procedures load a file and check the lines of that
+# file. Usually they make use of several checklines_*() and checkline_*()
+# procedures.
+#
+# The checkdir_*() procedures check the files of a directory and call
+# checkfile_*() on them.
+#
+# Note: I have tried to order the subroutines so that there are no
+# back-references, that is, if you start reading the code from the top to
+# the bottom you should not find a call to a subroutine you haven't yet
+# seen.
+#==========================================================================
+use strict;
+use warnings;
+
+use Data::Dumper;
+use Digest::SHA1;
+use Getopt::Long qw(:config no_ignore_case bundling require_order);
+use Fcntl qw(:mode);
+use File::Basename;
+use File::stat;
+use Cwd;
+use pkgsrc::Dewey;
+
+BEGIN {
+	import PkgLint::Util qw(
+		array_to_hash assert
+		false true dont_know doesnt_matter
+		normalize_pathname
+	);
+	import PkgLint::Logging qw(
+		NO_FILE NO_LINE_NUMBER NO_LINES
+		log_fatal log_error log_warning log_note log_debug
+		explain_error explain_warning explain_info
+	);
+	import PkgLint::FileUtil qw(
+		load_file load_lines
+		save_autofix_changes
+	);
+	import PkgLint::Type qw(
+		LK_NONE LK_INTERNAL LK_EXTERNAL
+		GUESSED NOT_GUESSED
+	);
+	import PkgLint::VarUseContext qw(
+		VUC_TIME_UNKNOWN VUC_TIME_LOAD VUC_TIME_RUN
+		VUC_TYPE_UNKNOWN
+		VUC_SHELLWORD_UNKNOWN VUC_SHELLWORD_PLAIN VUC_SHELLWORD_DQUOT
+		  VUC_SHELLWORD_SQUOT VUC_SHELLWORD_BACKT VUC_SHELLWORD_FOR
+		VUC_EXTENT_UNKNOWN VUC_EXTENT_FULL VUC_EXTENT_WORD
+		  VUC_EXTENT_WORD_PART
+	);
+}
+
+#
+# Buildtime configuration
+#
+
+use constant conf_distver	=> '@DISTVER@';
+use constant conf_make		=> '@MAKE@';
+use constant conf_datadir	=> '@DATADIR@';
+
+#
+# Global variables that can be modified via command line options.
+#
+
+# The pkgsrc directory, relative to the current working directory of
+# pkglint.
+my $cwd_pkgsrcdir	= undef;
+
+# The pkgsrc directory, relative to the directory that is currently
+# checked.
+my $cur_pkgsrcdir	= undef;
+
+#
+# Command Line Options
+#
+
+my $opt_check_ALTERNATIVES = true;
+my $opt_check_bl3	= true;
+my $opt_check_DESCR	= true;
+my $opt_check_distinfo	= true;
+my $opt_check_extra	= false;
+my $opt_check_global	= false;
+my $opt_check_INSTALL	= true;
+my $opt_check_Makefile	= true;
+my $opt_check_MESSAGE	= true;
+my $opt_check_mk	= true;
+my $opt_check_patches	= true;
+my $opt_check_PLIST	= true;
+my (%checks) = (
+	"ALTERNATIVES"	=> [\$opt_check_ALTERNATIVES, "check ALTERNATIVES files"],
+	"bl3"		=> [\$opt_check_bl3, "check buildlink3 files"],
+	"DESCR"		=> [\$opt_check_DESCR, "check DESCR file"],
+	"distinfo"	=> [\$opt_check_distinfo, "check distinfo file"],
+	"extra"		=> [\$opt_check_extra, "check various additional files"],
+	"global"	=> [\$opt_check_global, "inter-package checks"],
+	"INSTALL"	=> [\$opt_check_INSTALL, "check INSTALL and DEINSTALL scripts"],
+	"Makefile"	=> [\$opt_check_Makefile, "check Makefiles"],
+	"MESSAGE"	=> [\$opt_check_MESSAGE, "check MESSAGE files"],
+	"mk"		=> [\$opt_check_mk, "check other .mk files"],
+	"patches"	=> [\$opt_check_patches, "check patches"],
+	"PLIST"		=> [\$opt_check_PLIST, "check PLIST files"],
+);
+
+my $opt_debug_include	= false;
+my $opt_debug_misc	= false;
+my $opt_debug_patches	= false;
+my $opt_debug_quoting	= false;
+my $opt_debug_shell	= false;
+my $opt_debug_tools	= false;
+my $opt_debug_trace	= false;
+my $opt_debug_unchecked	= false;
+my $opt_debug_unused	= false;
+my $opt_debug_vartypes	= false;
+my $opt_debug_varuse	= false;
+my (%debug) = (
+	"include"	=> [\$opt_debug_include, "included files"],
+	"misc"		=> [\$opt_debug_misc, "all things that didn't fit elsewhere"],
+	"patches"	=> [\$opt_debug_patches, "the states of the patch parser"],
+	"quoting"	=> [\$opt_debug_quoting, "additional information about quoting"],
+	"shell"		=> [\$opt_debug_shell, "the parsers for shell words and shell commands"],
+	"tools"		=> [\$opt_debug_tools, "the tools framework"],
+	"trace"		=> [\$opt_debug_trace, "follow subroutine calls"],
+	"unchecked"	=> [\$opt_debug_unchecked, "show the current limitations of pkglint"],
+	"unused"	=> [\$opt_debug_unused, "unused variables"],
+	"vartypes"	=> [\$opt_debug_vartypes, "additional type information"],
+	"varuse"	=> [\$opt_debug_varuse, "contexts where variables are used"],
+);
+
+my $opt_warn_absname	= true;
+my $opt_warn_directcmd	= true;
+our $opt_warn_extra	= false;	# used by PkgLint::SubstContext
+my $opt_warn_order	= true;
+my $opt_warn_perm	= false;
+my $opt_warn_plist_depr	= false;
+my $opt_warn_plist_sort	= false;
+my $opt_warn_quoting	= false;
+my $opt_warn_space	= false;
+my $opt_warn_style	= false;
+my $opt_warn_types	= true;
+my $opt_warn_varorder	= false;
+my (%warnings) = (
+	"absname"	=> [\$opt_warn_absname, "warn about use of absolute file names"],
+	"directcmd"	=> [\$opt_warn_directcmd, "warn about use of direct command names instead of Make variables"],
+	"extra"		=> [\$opt_warn_extra, "enable some extra warnings"],
+	"order"		=> [\$opt_warn_order, "warn if Makefile entries are unordered"],
+	"perm"		=> [\$opt_warn_perm, "warn about unforeseen variable definition and use"],
+	"plist-depr"	=> [\$opt_warn_plist_depr, "warn about deprecated paths in PLISTs"],
+	"plist-sort"	=> [\$opt_warn_plist_sort, "warn about unsorted entries in PLISTs"],
+	"quoting"	=> [\$opt_warn_quoting, "warn about quoting issues"],
+	"space"		=> [\$opt_warn_space, "warn about inconsistent use of white-space"],
+	"style"		=> [\$opt_warn_style, "warn about stylistic issues"],
+	"types"		=> [\$opt_warn_types, "do some simple type checking in Makefiles"],
+	"varorder"	=> [\$opt_warn_varorder, "warn about the ordering of variables"],
+);
+
+my $opt_autofix		= false;
+my $opt_dumpmakefile	= false;
+my $opt_import		= false;
+my $opt_quiet		= false;
+my $opt_recursive	= false;
+my $opt_rcsidstring	= "NetBSD";
+my (@options) = (
+	# [ usage-opt, usage-message, getopt-opt, getopt-action ]
+	[ "-C{check,...}", "Enable or disable specific checks",
+	  "check|C=s",
+	  sub {
+		my ($opt, $val) = @_;
+		parse_multioption($val, \%checks);
+	  } ],
+	[ "-D{debug,...}", "Enable or disable debugging categories",
+	  "debugging|D=s",
+	  sub ($$) {
+		my ($opt, $val) = @_;
+		parse_multioption($val, \%debug);
+	  } ],
+	[ "-F|--autofix", "Try to automatically fix some errors (experimental)",
+	  "autofix|F", \$opt_autofix ],
+	[ "-I|--dumpmakefile", "Dump the Makefile after parsing",
+	  "dumpmakefile|I", \$opt_dumpmakefile ],
+	[ "-R|--rcsidstring", "Set the allowed RCS Id strings",
+	  "rcsidstring|R=s", \$opt_rcsidstring ],
+	[ "-V|--version", "print the version number of pkglint",
+	  "version|V",
+	  sub {
+		print(conf_distver . "\n");
+		exit(0);
+	  } ],
+	[ "-W{warn,...}", "enable or disable specific warnings",
+	  "warning|W=s",
+	  sub {
+		my ($opt, $val) = @_;
+		parse_multioption($val, \%warnings);
+	  } ],
+	[ "-e|--explain", "Explain the diagnostics or give further help",
+	  "explain|e", sub {
+		PkgLint::Logging::set_explain();
+	  } ],
+	[ "-g|--gcc-output-format", "Mimic the gcc output format",
+	  "gcc-output-format|g",
+	  sub {
+		PkgLint::Logging::set_gcc_output_format();
+	  } ],
+	[ "-h|--help", "print a detailed help message",
+	  "help|h",
+	  sub {
+		help(*STDOUT, 0, 1);
+	  } ],
+	[ "-i|--import", "Prepare the import of a wip package",
+	  "import|i", \$opt_import ],
+	# Note: This is intentionally undocumented.
+	[ "--pkgsrcdir", "Set the root directory of pkgsrc explicitly.",
+	  "pkgsrcdir=s", \$cwd_pkgsrcdir ],
+	[ "-q|--quiet", "Don't print a summary line when finishing",
+	  "quiet|q", \$opt_quiet ],
+	[ "-r|--recursive", "Recursive---check subdirectories, too",
+	  "recursive|r", \$opt_recursive ],
+	[ "-s|--source", "Show the source lines together with diagnostics",
+	  "source|s",
+	  sub {
+		PkgLint::Logging::set_show_source_flag();
+	  } ],
+);
+
+our $program		= $0;
+
+#
+# Commonly used regular expressions.
+#
+
+use constant regex_dependency_lge => qr"^((?:\$\{[\w_]+\}|[\w_\.+]|-[^\d])+)[<>]=?(\d[^-*?\[\]]*)$";
+use constant regex_dependency_wildcard
+				=> qr"^((?:\$\{[\w_]+\}|[\w_\.+]|-[^\d\[])+)-(?:\[0-9\]\*|\d[^-]*)$";
+use constant regex_gnu_configure_volatile_vars
+				=> qr"^(?:.*_)?(?:CFLAGS||CPPFLAGS|CXXFLAGS|FFLAGS|LDFLAGS|LIBS)$";
+use constant regex_mk_comment	=> qr"^ *\s*#(.*)$";
+use constant regex_mk_cond	=> qr"^\.(\s*)(if|ifdef|ifndef|else|elif|endif|for|endfor|undef)(?:\s+([^\s#][^#]*?))?\s*(?:#.*)?$";
+use constant regex_mk_dependency=> qr"^([^\s:]+(?:\s*[^\s:]+)*)(\s*):\s*([^#]*?)(?:\s*#.*)?$";
+use constant regex_mk_include	=> qr"^\.\s*(s?include)\s+\"([^\"]+)\"\s*(?:#.*)?$";
+use constant regex_mk_sysinclude=> qr"^\.\s*s?include\s+<([^>]+)>\s*(?:#.*)?$";
+use constant regex_mk_shellvaruse => qr"(?:^|[^\$])\$\$\{?(\w+)\}?"; # XXX: not perfect
+use constant regex_pkgname	=> qr"^([\w\-.+]+)-(\d(?:\w|\.\d)*)$";
+use constant regex_mk_shellcmd	=> qr"^\t(.*)$";
+use constant regex_rcs_conflict	=> qr"^(<<<<<<<|=======|>>>>>>>)";
+use constant regex_unresolved	=> qr"\$\{";
+use constant regex_validchars	=> qr"[\011\040-\176]";
+# Note: the following regular expression looks more complicated than
+# necessary to avoid a stack overflow in the Perl interpreter.
+# The leading white-space may only consist of \040 characters, otherwise
+# the order of regex_varassign and regex_mk_shellcmd becomes important.
+use constant regex_varassign	=> qr"^ *([-*+A-Z_a-z0-9.\${}\[]+?)\s*(=|\?=|\+=|:=|!=)\s*((?:[^\\#\s]+|\s+?|(?:\\#)+|\\)*?)(?:\s*(#.*))?$";
+use constant regex_sh_varassign	=> qr"^([A-Z_a-z][0-9A-Z_a-z]*)=";
+
+# The following "constants" are often used in contexts where
+# interpolation comes handy, so they are variables. Nevertheless they
+# are not modified.
+
+# This regular expression cannot parse all kinds of shell programs, but
+# it will catch almost all shell programs that are portable enough to be
+# used in pkgsrc.
+my $regex_shellword		=  qr"\s*(
+	\#.*				# shell comment
+	|
+	(?:	'[^']*'			# single quoted string
+	|	\"(?:\\.|[^\"\\])*\"	# double quoted string
+	|	\`[^\`]*\`		# backticks string
+	|	\\\$\$			# an escaped dollar sign
+	|	\\[^\$]			# other escaped characters
+	|	\$[\w_]			# one-character make(1) variable
+	|	\$\{[^{}]+\}		# make(1) variable
+	|	\$\([^()]+\)		# make(1) variable, $(...)
+	|	\$[/\@<^]		# special make(1) variables
+	|	\$\$[0-9A-Z_a-z]+	# shell variable
+	|	\$\$[\#?@]		# special shell variables
+	|	\$\$\$\$		# the special pid shell variable
+	|	\$\$\{[0-9A-Z_a-z]+\}	# shell variable in braces
+	|	\$\$\(			# POSIX-style backticks replacement
+	|	[^\(\)'\"\\\s;&\|<>\`\$] # non-special character
+	|	\$\{[^\s\"'`]+		# HACK: nested make(1) variables
+	)+ | ;;? | &&? | \|\|? | \( | \) | >& | <<? | >>? | \#.*)"sx;
+my $regex_varname		= qr"(?:[-*+.0-9A-Z_a-z{}\[]+|\$\{[\w_]+\})+";
+my $regex_pkgbase		= qr"(?:[+.0-9A-Z_a-z]|-[A-Z_a-z])+";
+my $regex_pkgversion		= qr"\d(?:\w|\.\d)*";
+
+#
+# Commonly used explanations for diagnostics.
+#
+
+use constant expl_relative_dirs	=> (
+	"Directories in the form \"../../category/package\" make it easier to",
+	"move a package around in pkgsrc, for example from pkgsrc-wip to the",
+	"main pkgsrc repository.");
+
+#
+# Global variables.
+#
+
+my $current_dir;		# The currently checked directory.
+my $is_wip;			# Is the current directory from pkgsrc-wip?
+my $is_internal;		# Is the current item from the infrastructure?
+
+#
+# Variables for inter-package checks.
+#
+
+my $ipc_distinfo;		# Maps "$alg:$fname" => "checksum".
+my %ipc_used_licenses;		# { license name => true }
+my $ipc_checking_root_recursively; # For checking unused licenses
+
+# Context of the package that is currently checked.
+my $pkgpath;			# The relative path to the package within PKGSRC
+my $pkgdir;			# PKGDIR from the package Makefile
+my $filesdir;			# FILESDIR from the package Makefile
+my $patchdir;			# PATCHDIR from the package Makefile
+my $distinfo_file;		# DISTINFO_FILE from the package Makefile
+my $effective_pkgname;		# PKGNAME or DISTNAME from the package Makefile
+my $effective_pkgbase;		# The effective PKGNAME without the version
+my $effective_pkgversion;	# The version part of the effective PKGNAME
+my $effective_pkgname_line;	# The origin of the three effective_* values
+my $seen_bsd_prefs_mk;		# Has bsd.prefs.mk already been included?
+
+my $pkgctx_vardef;		# { varname => line }
+my $pkgctx_varuse;		# { varname => line }
+my $pkgctx_bl3;			# { buildlink3.mk name => line } (contains
+				# only buildlink3.mk files that are directly
+				# included)
+my $pkgctx_plist_subst_cond;	# { varname => 1 } list of all variables
+				# that are used as conditionals (@comment
+				# or nothing) in PLISTs.
+my $pkgctx_included;		# { fname => line }
+my $seen_Makefile_common;	# Does the package have any .includes?
+
+# Context of the Makefile that is currently checked.
+my $mkctx_for_variables;	# The variables currently used in .for loops
+my $mkctx_indentations;		# Indentation depth of preprocessing directives
+my $mkctx_target;		# Current make(1) target
+my $mkctx_vardef;		# { varname => line } for all variables that
+				# are defined in the current file
+my $mkctx_varuse;		# { varname => line } for all variables
+				# that are used in the current file
+my $mkctx_build_defs;		# Set of variables that are registered in
+				# BUILD_DEFS, to assure that all user-defined
+				# variables are added to it.
+my $mkctx_plist_vars;		# The same for PLIST_VARS.
+my $mkctx_tools;		# Set of tools that are declared to be used.
+
+my @todo_items;			# The list of directory entries that still need
+				# to be checked. Mostly relevant with
+				# --recursive.
+
+#
+# Command line parsing and handling.
+#
+
+sub help($$$) {
+	my ($out, $exitval, $show_all) = @_;
+	my ($prog) = (basename($program, '.pl'));
+	print $out ("usage: $prog [options] [package_directory]\n\n");
+
+	my (@option_table) = ();
+	foreach my $opt (@options) {
+		push(@option_table, ["  ", $opt->[0], $opt->[1]]);
+	}
+	print $out ("options:\n");
+	PkgLint::Util::print_table($out, \@option_table);
+	print $out ("\n");
+
+	if (!$show_all) {
+		exit($exitval);
+	}
+
+	my $categories = [
+		# options, leading text, 
+		[ \%checks, "checks", "check" ],
+		[ \%debug, "debugging options", "debug" ],
+		[ \%warnings, "warnings", "warning" ],
+	];
+	foreach my $category (@{$categories}) {
+		my ($options, $leading, $name) = (@{$category});
+		my $table = [
+			["  ", "all", "", "enable all ".$category->[1]],
+			["  ", "none", "", "disable all ".$category->[1]],
+		];
+
+		foreach my $opt (sort keys %{$options}) {
+			push(@{$table}, [ "  ", $opt,
+				(${$options->{$opt}->[0]} ? "(enabled)" : "(disabled)"),
+				$options->{$opt}->[1]]);
+		}
+
+		print $out ("${leading}: (use \"${name}\" to enable, \"no-${name}\" to disable)\n");
+		PkgLint::Util::print_table($out, $table);
+		print $out ("\n");
+	}
+
+	exit($exitval);
+}
+
+sub parse_multioption($$) {
+	my ($value, $optdefs) = @_;
+	foreach my $opt (split(qr",", $value)) {
+		if ($opt eq "none") {
+			foreach my $key (keys %{$optdefs}) {
+				${$optdefs->{$key}->[0]} = false;
+			}
+
+		} elsif ($opt eq "all") {
+			foreach my $key (keys %{$optdefs}) {
+				${$optdefs->{$key}->[0]} = true;
+			}
+
+		} else {
+			my ($value) = (($opt =~ s/^no-//) ? false : true);
+			if (exists($optdefs->{$opt})) {
+				${$optdefs->{$opt}->[0]} = $value;
+			} else {
+				print STDERR ("Invalid option: ${opt}\n");
+				help(*STDERR, 1, 0);
+			}
+		}
+	}
+}
+
+sub parse_command_line() {
+	my (%options);
+
+	foreach my $opt (@options) {
+		$options{$opt->[2]} = $opt->[3];
+	}
+
+	{
+		local $SIG{__WARN__} = sub {};
+		if (!GetOptions(%options)) {
+			help(*STDERR, 1, false);
+		}
+	}
+}
+
+#
+# Caching subroutines.
+#
+
+# The get_regex_plurals() function returns a regular expression that
+# matches for all make(1) variable names that are considered lists
+# of something.
+#
+# Rationale:
+#
+# The pkglint author thinks that variables containing lists of things
+# should have a name indicating some plural form. Sadly, there are other
+# reasons like backwards compatibility and other developer's
+# expectations that make changes to most of the following variables
+# highly unlikely.
+sub get_regex_plurals() {
+	state $result = undef;
+	return $result if defined($result);
+
+	my @plurals_ok = qw(
+		.*S
+		.*LIST
+		.*_AWK
+		.*_ENV
+		.*_REQD
+		.*_SED
+		.*_SKIP
+		BUILDLINK_LDADD
+		COMMENT
+		EXTRACT_ONLY
+		FETCH_MESSAGE
+		GENERATE_PLIST
+		PLIST_CAT
+		PLIST_PRE
+		PREPEND_PATH
+	);
+	my @plurals_missing_an_s = qw(
+		.*_OVERRIDE
+		.*_PREREQ
+		.*_SRC
+		.*_SUBST
+		.*_TARGET
+		.*_TMPL
+		BROKEN_EXCEPT_ON_PLATFORM
+		BROKEN_ON_PLATFORM
+		BUILDLINK_DEPMETHOD
+		BUILDLINK_TRANSFORM
+		EVAL_PREFIX
+		INTERACTIVE_STAGE
+		LICENSE
+		MASTER_SITE_.*
+		MASTER_SORT_REGEX
+		NOT_FOR_COMPILER
+		NOT_FOR_PLATFORM
+		ONLY_FOR_COMPILER
+		ONLY_FOR_PLATFORM
+		PERL5_PACKLIST
+		PKG_FAIL_REASON
+		PKG_SKIP_REASON
+	);
+	my @plurals_reluctantly_accepted = qw(
+		CRYPTO
+		DEINSTALL_TEMPLATE
+		FIX_RPATH
+		INSTALL_TEMPLATE
+		PYTHON_VERSIONS_INCOMPATIBLE
+		REPLACE_INTERPRETER
+		REPLACE_PERL
+		REPLACE_RUBY
+		RESTRICTED
+		SITES_.*
+		TOOLS_ALIASES\.*
+		TOOLS_BROKEN
+		TOOLS_CREATE
+		TOOLS_GNU_MISSING
+		TOOLS_NOOP
+	);
+	my $plurals = join("|",
+		@plurals_ok,
+		@plurals_missing_an_s,
+		@plurals_reluctantly_accepted
+	);
+
+	$result = qr"^(?:${plurals})$";
+	return $result;
+}
+
+#
+# Loading pkglint-specific data from files.
+#
+
+sub load_existing_lines($$) {
+	my ($fname, $fold_backslash_lines) = @_;
+
+	my $lines = load_lines($fname, $fold_backslash_lines)
+		or log_fatal($fname, NO_LINE_NUMBER, "Cannot be read.");
+	return $lines;
+}
+
+# The symbol table for ACL definitions maps ACL names to ACLs.
+my $acl_definitions = {};
+
+sub parse_acls($$) {
+	my ($line, $acltext) = @_;
+	my ($acls);
+
+	use constant ACL_shortcuts => {
+		"b" => qr"(?:^|/)buildlink3\.mk$",
+		"c" => qr"(?:^|/)Makefile\.common$",
+		"h" => qr"(?:^|/)hacks\.mk$",
+		"m" => qr"(?:^|/)Makefile$",
+		"o" => qr"(?:^|/)options\.mk$",
+	};
+
+	my $regex_acl_entry = qr"^(?:
+		  \$([\w_]+)			# $acl_name
+		| ([\w.*]+|_):([adpsu]*)	# file*mask:perms
+		) (?:\,\s*|$)"x;
+
+	if (!defined($acltext)) {
+		return undef;
+	}
+
+	$acls = [];
+	while ($acltext =~ s,$regex_acl_entry,,) {
+		my ($acldef, $subject, $perms) = ($1, $2, $3);
+
+		if (defined($acldef)) {
+			if (!exists($acl_definitions->{$acldef})) {
+				$line->log_fatal("ACL definition ${acldef} not found.");
+			} else {
+				push(@{$acls}, @{$acl_definitions->{$acldef}});
+			}
+
+		} else {
+			# Transform $subject to a regular expression.
+			$subject =~ s/\./[.]/g;
+			$subject =~ s/\*/.*/g;
+
+			push(@{$acls}, [exists(ACL_shortcuts->{$subject}) ? ACL_shortcuts->{$subject} : qr"(?:^|/)${subject}$", $perms]);
+		}
+	}
+	if ($acltext ne "") {
+		$line->log_fatal("Invalid ACL: ${acltext}.");
+	}
+
+	return $acls;
+}
+
+sub get_vartypes_basictypes() {
+	state $result = undef;
+	return $result if defined($result);
+
+	my $lines = load_file($program);
+	my $types = {};
+	assert($lines, "Couldn't load pkglint.pl from $program");
+	foreach my $line (@$lines) {
+		if ($line->text =~ m"^\s+(\w+) => sub \{$") {
+			# XXX lookup in %type_dispatch instead
+			$types->{$1} = 1;
+		}
+	}
+	return ($result = $types);
+}
+
+sub get_vartypes_map() {
+	state $result = undef;
+	return $result if defined($result);
+
+	my ($fname, $vartypes);
+
+	use constant re_acl_def => qr"^
+		acl \s+
+		(\w+) \s+				# ACL name
+		= \s+
+		\[ ([^\]]*) \]				# ACL value
+		(?:\s*\#.*)?				# optional comment
+		$"x;
+
+	use constant re_vartypedef => qr"^
+		([\w\d_.]+?)				# $1 = variable name
+		(\*|\.\*|) \s+				# $2 = parameterized?
+		(?:(InternalList|List) \s+ of \s+)?	# $3 ?= kind of list
+		(?:([\w\d_]+)				# $4 ?= basic type
+		  | \{\s*([\w\d_+,\-.\s]+?)\s*\})	# $5 ?= enumeration values
+		(?:\s+ \[ ([^\]]*) \])?			# $6 ?= optional ACL
+		(?:\s*\#.*)?				# $7 ?= optional comment
+		$"x;
+
+	$fname = conf_datadir."/makevars.map";
+	$vartypes = {};
+
+	my $lines = load_existing_lines($fname, true);
+	foreach my $line (@{$lines}) {
+		if ($line->text =~ m"^(?:#.*|\s*)$") {
+			# ignore empty and comment lines
+
+		} elsif ($line->text =~ re_acl_def) {
+			my ($aclname, $aclvalue) = ($1, $2);
+
+			$acl_definitions->{$aclname} = parse_acls($line, $aclvalue);
+
+		} elsif ($line->text =~ re_vartypedef) {
+			my ($varname, $par, $kind_of_list_text, $typename, $enums, $acltext) = ($1, $2, $3, $4, $5, $6);
+			my $kind_of_list = !defined($kind_of_list_text) ? LK_NONE
+			    : ($kind_of_list_text eq "List") ? LK_EXTERNAL
+			    : LK_INTERNAL;
+
+			if (defined($typename) && !exists(get_vartypes_basictypes()->{$typename})) {
+				$line->log_fatal("Unknown basic type \"$typename\" for variable $varname. "
+					. "Valid basic types are "
+					. join(", ", sort keys %{get_vartypes_basictypes()})
+					. ".");
+			}
+
+			my $basic_type = defined($enums)
+			    ? array_to_hash(split(qr"\s+", $enums))
+			    : $typename;
+			my $type = PkgLint::Type->new($kind_of_list, $basic_type, parse_acls($line, $acltext), NOT_GUESSED);
+			if ($par eq "" || $par eq "*") {
+				$vartypes->{$varname} = $type;
+			}
+			if ($par eq "*" || $par eq ".*") {
+				$vartypes->{"${varname}.*"} = $type;
+			}
+
+		} else {
+			$line->log_fatal("Unknown line format.");
+		}
+	}
+
+# TODO: Enable when the time is ripe.
+if (false) {
+	# Additionally, scan mk/defaults/mk.conf for variable
+	# definitions. All these variables are reserved for the user and
+	# must not be set within packages.
+	$fname = "${cwd_pkgsrcdir}/mk/defaults/mk.conf";
+	if ((my $lines = load_file($fname))) {
+		foreach my $line (@{$lines}) {
+			if ($line->text =~ m"^#?([\w_]+)\?=") {
+				my ($varname) = ($1);
+				$opt_debug_misc and $line->log_debug("Found user-definable variable ${varname}.");
+				$vartypes->{$varname} = "Userdefined"; # FIXME: type error
+			}
+		}
+	} else {
+		log_fatal($fname, NO_LINE_NUMBER, "Cannot be read.");
+	}
+}
+
+	return ($result = $vartypes);
+}
+
+sub get_deprecated_map() {
+	state $result = undef;
+	return $result if defined($result);
+
+	my ($fname, $lines, $vars);
+
+	$fname = conf_datadir."/deprecated.map";
+	if (!($lines = load_file($fname))) {
+		log_fatal($fname, NO_LINE_NUMBER, "Cannot be read.");
+	}
+
+	$vars = {};
+	foreach my $line (@{$lines}) {
+		if ($line->text =~ m"^#" || $line->text =~ m"^\s*$") {
+			# Ignore empty and comment lines.
+
+		} elsif ($line->text =~ m"^(\S+)\s+(.*)$") {
+			$vars->{$1} = $2;
+
+		} else {
+			$line->log_fatal("Unknown line format.");
+		}
+	}
+	return ($result = $vars);
+}
+
+my $load_dist_sites_url2name = undef;
+my $load_dist_sites_names = undef;
+sub load_dist_sites() {
+	my ($fname) = ("${cwd_pkgsrcdir}/mk/fetch/sites.mk");
+	my ($lines) = load_file($fname);
+	my ($varname) = undef;
+	my ($ignoring) = false;
+	my ($url2name) = {};
+	my ($names) = {};
+
+	if (!$lines) {
+		log_error($fname, NO_LINE_NUMBER, "Could not be read.");
+		$load_dist_sites_url2name = $url2name;
+		$load_dist_sites_names = $names;
+		return;
+	}
+	foreach my $line (@{$lines}) {
+		my $text = $line->text;
+
+		if ($text =~ m"^(MASTER_SITE_\w+)\+=\s*\\$"o) {
+			$varname = $1;
+			$names->{$varname} = true;
+			$ignoring = false;
+
+		} elsif ($text eq "MASTER_SITE_BACKUP?=\t\\") {
+			$ignoring = true;
+
+		} elsif ($text =~ m"^\t((?:http://|https://|ftp://)\S+/)(?:|\s*\\)$"o) {
+			if (!$ignoring) {
+				if (defined($varname)) {
+					$url2name->{$1} = $varname;
+				} else {
+					$line->log_error("Lonely URL found.");
+				}
+			}
+
+		} elsif ($text =~ m"^(?:#.*|\s*)$") {
+			# ignore empty and comment lines
+
+		} elsif ($text =~ m"BSD_SITES_MK") {
+			# ignore multiple inclusion guards
+
+		} else {
+			$line->log_fatal("Unknown line type.");
+		}
+	}
+
+	# Explicitly allowed, although not defined in mk/fetch/sites.mk.
+	$names->{"MASTER_SITE_SUSE_UPD"} = true;
+	$names->{"MASTER_SITE_LOCAL"} = true;
+
+	$opt_debug_misc and log_debug($fname, NO_LINES, "Loaded " . scalar(keys(%{$url2name})) . " MASTER_SITE_* definitions.");
+	$load_dist_sites_url2name = $url2name;
+	$load_dist_sites_names = $names;
+}
+
+sub get_dist_sites() {
+	if (!defined($load_dist_sites_url2name)) {
+		load_dist_sites();
+	}
+	return $load_dist_sites_url2name;
+}
+
+sub get_dist_sites_names() {
+	if (!defined($load_dist_sites_names)) {
+		load_dist_sites();
+	}
+	return $load_dist_sites_names;
+}
+
+sub get_pkg_options() {
+	state $result = undef;
+	return $result if defined($result);
+
+	my ($fname) = ("${cwd_pkgsrcdir}/mk/defaults/options.description");
+	my ($lines, $options);
+
+	if (!($lines = load_file($fname))) {
+		log_fatal($fname, NO_LINE_NUMBER, "Cannot be read.");
+	}
+
+	$options = {};
+	foreach my $line (@{$lines}) {
+		if ($line->text =~ m"^([-0-9a-z_+]+)(?:\s+(.*))?$") {
+			my ($optname, $optdescr) = ($1, $2);
+
+			$options->{$optname} = defined($optdescr)
+			    ? $optdescr
+			    : "";
+		} else {
+			$line->log_error("Unknown line format.");
+		}
+	}
+
+	return ($result = $options);
+}
+
+my $load_tool_names_system_build_defs = undef;		# XXX: misplaced, but works
+my $load_tool_names_tools = undef;
+my $load_tool_names_vartools = undef;
+my $load_tool_names_varname_to_toolname = undef;
+my $load_tool_names_predefined_tools = undef;
+sub load_tool_names() {
+	my ($tools, $vartools, $predefined_tools, $varname_to_toolname, @tool_files);
+	my ($system_build_defs);
+
+	#
+	# Get the list of files that define the tools from bsd.tools.mk.
+	#
+
+	@tool_files = ("defaults.mk");
+	{
+		my $fname = "${cwd_pkgsrcdir}/mk/tools/bsd.tools.mk";
+		my $lines = load_existing_lines($fname, true);
+		foreach my $line (@{$lines}) {
+			if ($line->text =~ regex_mk_include) {
+				my (undef, $includefile) = ($1, $2);
+				if ($includefile =~ m"^(?:\$\{PKGSRCDIR\}/mk/tools/)?([^/]+)$") {
+					push(@tool_files, $1);
+				}
+			}
+		}
+	}
+	assert(scalar(@tool_files) > 1, "Too few tool files. Maybe the files have been renamed again?");
+
+	#
+	# Scan the tool files for the actual definitions of the tools.
+	#
+
+	$tools = {};
+	$vartools = {};
+	$predefined_tools = {};
+	$varname_to_toolname = {};
+	$system_build_defs = {};
+	foreach my $basename (@tool_files) {
+		my $fname = "${cwd_pkgsrcdir}/mk/tools/${basename}";
+		my $lines = load_existing_lines($fname, true);
+		foreach my $line (@{$lines}) {
+			if ($line->text =~ regex_varassign) {
+				my ($varname, undef, $value, undef) = ($1, $2, $3, $4);
+				if ($varname eq "TOOLS_CREATE" && $value =~ m"^([-\w.]+|\[)$") {
+					$tools->{$value} = true;
+
+				} elsif ($varname =~ m"^(?:_TOOLS_VARNAME)\.([-\w.]+|\[)$") {
+					$tools->{$1} = true;
+					$vartools->{$1} = $value;
+					$varname_to_toolname->{$value} = $1;
+
+				} elsif ($varname =~ m"^(?:TOOLS_PATH|_TOOLS_DEPMETHOD)\.([-\w.]+|\[)$") {
+					$tools->{$1} = true;
+
+				} elsif ($varname =~ m"^_TOOLS\.(.*)") {
+					$tools->{$1} = true;
+					foreach my $tool (split(qr"\s+", $value)) {
+						$tools->{$tool} = true;
+					}
+				}
+			}
+		}
+	}
+
+	foreach my $basename ("bsd.pkg.mk") {
+		my $fname = "${cwd_pkgsrcdir}/mk/${basename}";
+		my $cond_depth = 0;
+
+		my $lines = load_existing_lines($fname, true);
+		foreach my $line (@{$lines}) {
+			my $text = $line->text;
+
+			if ($text =~ regex_varassign) {
+				my ($varname, undef, $value, undef) = ($1, $2, $3, $4);
+
+				if ($varname eq "USE_TOOLS") {
+					$opt_debug_tools and $line->log_debug("[cond_depth=${cond_depth}] $value");
+					if ($cond_depth == 0) {
+						foreach my $tool (split(qr"\s+", $value)) {
+							if ($tool !~ regex_unresolved && exists($tools->{$tool})) {
+								$predefined_tools->{$tool} = true;
+								# The path (without arguments) to the tool
+								$predefined_tools->{"TOOLS_${tool}"} = true;
+							}
+						}
+					}
+				} elsif ($varname eq "_BUILD_DEFS") {
+					foreach my $bdvar (split(qr"\s+", $value)) {
+						$system_build_defs->{$bdvar} = true;
+					}
+				}
+
+			} elsif ($text =~ regex_mk_cond) {
+				my ($indent, $cond, $args, $comment) = ($1, $2, $3, $4);
+
+				if ($cond =~ m"^(?:if|ifdef|ifndef|for)$") {
+					$cond_depth++;
+				} elsif ($cond =~ m"^(?:endif|endfor)$") {
+					$cond_depth--;
+				}
+			}
+		}
+	}
+
+	$opt_debug_tools and log_debug(NO_FILE, NO_LINE_NUMBER, "Known tools: ".join(" ", sort(keys(%{$tools}))));
+	$opt_debug_tools and log_debug(NO_FILE, NO_LINE_NUMBER, "Known vartools: ".join(" ", sort(keys(%{$vartools}))));
+	$opt_debug_tools and log_debug(NO_FILE, NO_LINE_NUMBER, "Predefined tools: " . join(" ", sort(keys(%{$predefined_tools}))));
+	$opt_debug_tools and log_debug(NO_FILE, NO_LINE_NUMBER, "Known varnames: " . join(" ", sort(keys(%{$varname_to_toolname}))));
+	$opt_debug_misc and log_debug(NO_FILE, NO_LINES, "System-provided BUILD_DEFS: " . join(" ", sort(keys(%{$system_build_defs}))));
+
+	# Some user-defined variables do not influence the binary
+	# package at all and therefore do not have to be added to
+	# BUILD_DEFS.
+	foreach my $bdvar (qw(DISTDIR FETCH_CMD FETCH_OUTPUT_ARGS GAMES_USER GAMES_GROUP GAMEDATAMODE GAMEDIRMODE GAMEMODE GAMEOWN GAMEGRP )) {
+		$system_build_defs->{$bdvar} = true;
+	}
+	#$system_build_defs->{"PACKAGES"} = true;
+
+	$load_tool_names_tools = $tools;
+	$load_tool_names_vartools = $vartools;
+	$load_tool_names_predefined_tools = $predefined_tools;
+	$load_tool_names_varname_to_toolname = $varname_to_toolname;
+	$load_tool_names_system_build_defs = $system_build_defs;
+}
+
+# Returns the set of known tool names and contains for example "sed" and
+# "gm4".
+sub get_tool_names() {
+
+	if (!defined($load_tool_names_tools)) {
+		load_tool_names();
+	}
+	return $load_tool_names_tools;
+}
+
+# Returns the mapping from tool names to their respective variable. For
+# example, "sed" => "SED", "gzip" => "GZIP_CMD".
+sub get_vartool_names() {
+
+	if (!defined($load_tool_names_vartools)) {
+		load_tool_names();
+	}
+	return $load_tool_names_vartools;
+}
+
+# Returns the set of those tools with associated variables that a
+# package does not need to add to USE_TOOLS explicitly because they
+# are used by the pkgsrc infrastructure, too.
+sub get_predefined_tool_names() {
+	if (!defined($load_tool_names_predefined_tools)) {
+		load_tool_names();
+	}
+	return $load_tool_names_predefined_tools;
+}
+
+# Returns a mapping from tool variable names to the tool name they use.
+# For example, "GZIP_CMD" => "gzip" and "SED" => "sed".
+sub get_varname_to_toolname() {
+	if (!defined($load_tool_names_varname_to_toolname)) {
+		load_tool_names();
+	}
+	return $load_tool_names_varname_to_toolname;
+}
+
+# Returns the set of tool variable names that may not be converted to
+# their "direct" form, that is: ${CP} => cp.
+sub get_required_vartool_varnames() {
+	use constant required_vartool_varnames => array_to_hash(qw(ECHO ECHO_N FALSE TEST TRUE));
+
+	return required_vartool_varnames;
+}
+
+# Returns the set of tools that must be used by their variable name.
+sub get_required_vartools() {
+	use constant required_vartools => array_to_hash(qw(echo false test true));
+
+	return required_vartools;
+}
+
+
+# Returns the set of user-defined variables that are added to BUILD_DEFS
+# within the bsd.pkg.mk file.
+sub get_system_build_defs() {
+	if (!defined($load_tool_names_system_build_defs)) {
+		load_tool_names();
+	}
+	return $load_tool_names_system_build_defs;
+}
+
+sub load_doc_TODO_updates($) {
+	my ($fname) = @_;
+	my ($lines, $updates, $state, $re_suggested_update);
+
+	if (!($lines = load_file($fname))) {
+		log_fatal($fname, NO_LINE_NUMBER, "Cannot be read.");
+	}
+
+	$updates = [];
+	$state = 0;
+	foreach my $line (@{$lines}) {
+		my $text = $line->text;
+
+		if ($state == 0 && $text eq "Suggested package updates") {
+			$state = 1;
+		} elsif ($state == 1 && $text eq "") {
+			$state = 2;
+		} elsif ($state == 2) {
+			$state = 3;
+		} elsif ($state == 3 && $text eq "") {
+			$state = 4;
+		}
+
+		if ($state == 3) {
+			if ($text =~ m"^\to\s(\S+)(?:\s*(.+))?$") {
+				my ($spuname, $comment) = ($1, $2);
+				if ($spuname =~ regex_pkgname) {
+					push(@{$updates}, [$line, $1, $2, $comment]);
+				} else {
+					$line->log_warning("Invalid package name $spuname");
+				}
+			} else {
+				$line->log_warning("Invalid line format $text");
+			}
+		}
+	}
+
+	return $updates;
+}
+
+sub get_doc_TODO_updates() {
+	state $result = load_doc_TODO_updates("${cwd_pkgsrcdir}/doc/TODO");
+	return $result;
+}
+
+sub get_wip_TODO_updates() {
+	state $result = load_doc_TODO_updates("${cwd_pkgsrcdir}/wip/TODO");
+	return $result;
+}
+
+sub load_doc_CHANGES($) {
+	my ($fname) = @_;
+	my $lines = load_file($fname) or die;
+
+	my $changes = {}; # { pkgpath -> @changes }
+	foreach my $line (@$lines) {
+		my $text = $line->text;
+		next unless $text =~ m"^\t[A-Z]";
+
+		if ($text =~ m"^\t(Updated) (\S+) to (\S+) \[(\S+) (\d\d\d\d-\d\d-\d\d)\]$") {
+			push(@{$changes->{$2}}, PkgLint::Change->new($line, $1, $2, $3, $4, $5));
+		} elsif ($text =~ m"^\t(Added) (\S+) version (\S+) \[(\S+) (\d\d\d\d-\d\d-\d\d)\]$") {
+			push(@{$changes->{$2}}, PkgLint::Change->new($line, $1, $2, $3, $4, $5));
+		} elsif ($text =~ m"^\t(Removed) (\S+) (?:successor (\S+) )?\[(\S+) (\d\d\d\d-\d\d-\d\d)\]$") {
+			push(@{$changes->{$2}}, PkgLint::Change->new($line, $1, $2, undef, $3, $4));
+		} elsif ($text =~ m"^\t(Downgraded) (\S+) to (\S+) \[(\S+) (\d\d\d\d-\d\d-\d\d)\]$") {
+			push(@{$changes->{$2}}, PkgLint::Change->new($line, $1, $2, $3, $4, $5));
+		} elsif ($text =~ m"^\t(Renamed|Moved) (\S+) to (\S+) \[(\S+) (\d\d\d\d-\d\d-\d\d)\]$") {
+			push(@{$changes->{$2}}, PkgLint::Change->new($line, $1, $2, $3, $4, $5));
+		} else {
+			$line->log_warning("Unknown doc/CHANGES line: " . $line->text);
+			$line->explain_warning(
+"Maybe some developer didn't stick to the conventions that have been",
+"established by mk/misc/developer.mk?");
+		}
+	}
+	return $changes;
+}
+
+my $get_doc_CHANGES_docs = undef; # [ $fname, undef or { pkgpath -> @changes } ]
+sub get_doc_CHANGES($) {
+	my ($pkgpath) = @_;
+
+	$opt_debug_trace and log_debug(NO_FILE, NO_LINES, "get_doc_CHANGES(\"$pkgpath\")");
+
+	# Make a reversed list of all the CHANGES-* files, but don't load
+	# them yet.
+	if (!defined($get_doc_CHANGES_docs)) {
+		opendir(DIR, "${cwd_pkgsrcdir}/doc") or die;
+		my @files = readdir(DIR);
+		closedir(DIR) or die;
+		foreach my $file (reverse sort @files) {
+			if ($file =~ m"^CHANGES-(\d+)$" && (0 + $1 >= 2008)) {
+				push(@$get_doc_CHANGES_docs, [ $file, undef ]);
+			}
+		}
+		$opt_debug_misc and log_debug(NO_FILE, NO_LINES, "Found " . (scalar @$get_doc_CHANGES_docs) . " changes files.");
+	}
+
+	# Scan the *-CHANGES files in reverse order until some action
+	# matches the package directory.
+	my @result = ();
+	foreach my $doc (@$get_doc_CHANGES_docs) {
+		if (!defined($doc->[1])) {
+			$opt_debug_misc and log_debug(NO_FILE, NO_LINES, "loading $doc->[0]");
+			$doc->[1] = load_doc_CHANGES("${cwd_pkgsrcdir}/doc/$doc->[0]");
+		}
+
+		foreach my $change (@{$doc->[1]->{$pkgpath}}) {
+			next unless $pkgpath eq $change->pkgpath;
+			push(@result, $change);
+		}
+		if (@result != 0) {
+			return @result;
+		}
+	}
+	return ();
+}
+
+sub get_suggested_package_updates() {
+
+	return ($is_wip)
+	    ? get_wip_TODO_updates()
+	    : get_doc_TODO_updates();
+}
+
+# Load all variables from mk/defaults/mk.conf. Since pkglint does not
+# load the infrastructure files during normal operation, these
+# definitions have to be added explicitly.
+sub load_userdefined_variables() {
+	my $fname = "${cwd_pkgsrcdir}/mk/defaults/mk.conf";
+	my $vars = {};
+
+	my $lines = load_existing_lines($fname, true);
+	foreach my $line (@{$lines}) {
+		if ($line->text =~ regex_varassign) {
+			my ($varname, $op, $value, $comment) = ($1, $2, $3, $4);
+
+			$vars->{$varname} = $line;
+		}
+	}
+
+	return $vars;
+}
+
+sub get_userdefined_variables() {
+	state $result = load_userdefined_variables();
+	return $result;
+}
+
+#
+# Miscellaneous functions
+#
+
+sub match_all($$) {
+	my ($text, $re) = @_;
+	my ($mm, $rest, $lastpos);
+
+	$mm = [];
+	$rest = $text;
+	$lastpos = 0;
+	pos(undef);
+	while ($rest =~ m/$re/gc) {
+		my @starts = @-;
+		my @ends = @+;
+
+		$lastpos = $ends[0];
+
+		push(@{$mm}, PkgLint::SimpleMatch->new($text, \@starts, \@ends));
+	}
+	return ($mm, substr($rest, $lastpos));
+}
+
+sub autofix($) {
+	my ($lines) = @_;
+
+	if ($opt_autofix) {
+		save_autofix_changes($lines);
+	}
+}
+
+# Checks whether a file is already committed to the CVS repository or not.
+sub is_committed($) {
+	my ($fname) = @_;
+	my ($basename, $entries);
+
+	$basename = basename($fname);
+	$entries = load_file(dirname($fname) . "/CVS/Entries");
+	if (!$entries) {
+		return false;
+	}
+	foreach my $entry (@{$entries}) {
+		if ($entry->text =~ m"^/\Q${basename}\E/") {
+			return true;
+		}
+	}
+	return false;
+}
+
+# Checks whether a directory is practically empty, that is, all it
+# contains are ".", ".." and "CVS", recursively.
+sub is_emptydir($);
+sub is_emptydir($) {
+	my ($dir) = @_;
+	my ($rv);
+
+	if (!opendir(DIR, $dir)) {
+		return true;
+	}
+	my @subdirs = readdir(DIR);
+	closedir(DIR) or die;
+
+	$rv = true;
+	foreach my $subdir (@subdirs) {
+		next if $subdir eq "." || $subdir eq ".." || $subdir eq "CVS";
+		next if -d "${dir}/${subdir}" && is_emptydir("${dir}/${subdir}");
+
+		$rv = false;
+		last;
+	}
+
+	return $rv;
+}
+
+# Returns the list of subdirectories of a directory, except "CVS".
+sub get_subdirs($) {
+	my ($dir) = @_;
+	my (@result) = ();
+
+	if (opendir(DIR, $dir)) {
+		my @subdirs = readdir(DIR);
+		closedir(DIR) or die;
+		foreach my $subdir (@subdirs) {
+			if ($subdir ne "." && $subdir ne ".." && $subdir ne "CVS" && -d "${dir}/${subdir}" && !is_emptydir("${dir}/${subdir}")) {
+				push(@result, $subdir);
+			}
+		}
+	}
+	return @result;
+}
+
+# No package file should ever be executable. Even the INSTALL and
+# DEINSTALL scripts are usually not usable in the form they have in the
+# package, as the pathnames get adjusted during installation. So there is
+# no need to have any file executable.
+sub checkperms($) {
+	my ($fname) = @_;
+
+	if (-f $fname && -x $fname && !is_committed($fname)) {
+		log_warning($fname, NO_LINE_NUMBER, "Should not be executable.");
+	}
+}
+
+sub resolve_relative_path($$) {
+	my ($relpath, $adjust_depth) = @_;
+
+	my $arg = $relpath;
+	$relpath =~ s,\$\{PKGSRCDIR\},$cur_pkgsrcdir,;
+	$relpath =~ s,\$\{\.CURDIR\},.,;
+	$relpath =~ s,\$\{\.PARSEDIR\},.,;
+	$relpath =~ s,\$\{LUA_PKGSRCDIR\},../../lang/lua52,;
+	$relpath =~ s,\$\{PHPPKGSRCDIR\},../../lang/php54,;
+	$relpath =~ s,\$\{SUSE_DIR_PREFIX\},suse100,;
+	$relpath =~ s,\$\{PYPKGSRCDIR\},../../lang/python27,;
+	$relpath =~ s,\$\{FILESDIR\},$filesdir, if defined($filesdir);
+	if ($adjust_depth && $relpath =~ m"^\.\./\.\./([^.].*)$") {
+		$relpath = "${cur_pkgsrcdir}/$1";
+	}
+	if (defined($pkgdir)) {
+		$relpath =~ s,\$\{PKGDIR\},$pkgdir,g;
+	}
+
+	$opt_debug_misc and log_debug(NO_FILE, NO_LINES, "resolve_relative_path: $arg => $relpath");
+	return $relpath;
+}
+
+# Takes two pathnames and returns the relative pathname to get from
+# the first to the second.
+sub relative_path($$) {
+	my ($from, $to) = @_;
+
+	my $abs_from = Cwd::abs_path($from);
+	my $abs_to = Cwd::abs_path($to);
+	if ($abs_to =~ m"^\Q$abs_from/\E(.*)$") {
+		return $1;
+	} elsif ($abs_to eq $abs_from) {
+		return ".";
+	} else {
+		assert(false, "$abs_from is not a prefix of $abs_to");
+	}
+}
+
+sub resolve_variable_rec1($$);
+sub resolve_variable_rec2($$);
+
+sub resolve_variable_rec1($$) {
+	my ($varname, $visited) = @_;
+	$opt_debug_trace and log_debug(NO_FILE, NO_LINES, "resolve_variable_rec1($varname)");
+
+	if (!exists($visited->{$varname})) {
+		$visited->{$varname} = true;
+		if (defined($pkgctx_vardef) && exists($pkgctx_vardef->{$varname})) {
+			return resolve_variable_rec2($pkgctx_vardef->{$varname}->get("value"), $visited);
+		}
+		if (defined($mkctx_vardef) && exists($mkctx_vardef->{$varname})) {
+			return resolve_variable_rec2($mkctx_vardef->{$varname}->get("value"), $visited);
+		}
+	}
+	return "\${$varname}";
+}
+
+sub resolve_variable_rec2($$) {
+	my ($string, $visited) = @_;
+	$opt_debug_trace and log_debug(NO_FILE, NO_LINES, "resolve_variable_rec2(\"$string\")");
+
+	my $expanded = $string;
+	$expanded =~ s/\$\{(\w+)\}/resolve_variable_rec1($1, $visited)/eg;
+	return $expanded;
+}
+
+sub expand_variable($) {
+	my ($varname) = @_;
+
+	return unless exists($pkgctx_vardef->{$varname});
+	my $line = $pkgctx_vardef->{$varname};
+	my $value = $line->get("value");
+
+	$value = resolve_relative_path($value, true);
+	if ($value =~ regex_unresolved) {
+		$opt_debug_misc and log_debug(NO_FILE, NO_LINES, "[expand_variable] Trying harder to resolve variable references in ${varname}=\"${value}\".");
+		$value = resolve_variable_rec2($value, {});
+		if ($value =~ regex_unresolved) {
+			$opt_debug_misc and log_debug(NO_FILE, NO_LINES, "[expand_variable] Failed to resolve ${varname}=\"${value}\".");
+		}
+	}
+	return $value;
+}
+
+sub set_default_value($$) {
+	my ($varref, $value) = @_;
+
+	if (!defined(${$varref}) || ${$varref} =~ regex_unresolved) {
+		${$varref} = $value;
+	}
+}
+
+sub strip_mk_comment($) {
+	my ($text) = @_;
+
+	$text =~ s/(^|[^\\])#.*/$1/;
+	$text =~ s/\\#/#/g;
+	return $text;
+}
+
+# Removes all uses of make variables from a string.
+sub remove_variables($) {
+	my ($text) = @_;
+
+	while ($text =~ s/\$\{([^{}]*)\}//g) {
+	}
+	return $text;
+}
+
+sub backtrace($) {
+	my $msg = shift();
+	my (@callers);
+
+	my $n = 0;
+	while (my @info = caller($n)) {
+		push(@callers, [$info[2], $info[3]]);
+		$n++;
+	}
+
+	log_debug(NO_FILE, NO_LINE_NUMBER, $msg);
+	for (my $i = $#callers; $i >= 0; $i--) {
+		my $info = $callers[$i];
+		log_debug(NO_FILE, NO_LINE_NUMBER, sprintf("  line %4d called %s", $info->[0], $info->[1]));
+	}
+}
+
+# Returns the number of columns that a string occupies when printed with
+# a tabulator size of 8.
+sub tablen($) {
+	my ($s) = @_;
+	my ($len);
+
+	$len = 0;
+	foreach my $c (split(qr"", $s)) {
+		if ($c eq "\t") {
+			$len = ($len + 7) & ~7;
+		} else {
+			$len++;
+		}
+	}
+	return $len;
+}
+
+sub shell_split($) {
+	my ($text) = @_;
+	my ($words);
+
+	$words = [];
+	while ($text =~ s/^$regex_shellword//) {
+		push(@{$words}, $1);
+	}
+	return (($text =~ m"^\s*$") ? $words : false);
+}
+
+sub varname_base($) {
+	my ($varname) = @_;
+
+	return ($varname =~ m"^(.*?)\..*$") ? $1 : $varname;
+}
+
+sub varname_canon($) {
+	my ($varname) = @_;
+
+	return ($varname =~ m"^(.*?)\..*$") ? "$1.*" : $varname;
+}
+
+sub varname_param($) {
+	my ($varname) = @_;
+
+	return ($varname =~ m"^.*?\.(.*)$") ? $2 : undef;
+}
+
+sub use_var($$) {
+	my ($line, $varname) = @_;
+	my $varcanon = varname_canon($varname);
+
+	if (defined($mkctx_varuse)) {
+		$mkctx_varuse->{$varname} = $line;
+		$mkctx_varuse->{$varcanon} = $line;
+	}
+
+	if (defined($pkgctx_varuse)) {
+		$pkgctx_varuse->{$varname} = $line;
+		$pkgctx_varuse->{$varcanon} = $line;
+	}
+}
+
+sub var_is_used($) {
+	my ($varname) = @_;
+	my $varcanon = varname_canon($varname);
+
+	if (defined($mkctx_varuse)) {
+		return $mkctx_varuse->{$varname} if exists($mkctx_varuse->{$varname});
+		return $mkctx_varuse->{$varcanon} if exists($mkctx_varuse->{$varcanon});
+	}
+	if (defined($pkgctx_varuse)) {
+		return $pkgctx_varuse->{$varname} if exists($pkgctx_varuse->{$varname});
+		return $pkgctx_varuse->{$varcanon} if exists($pkgctx_varuse->{$varcanon});
+	}
+	return false;
+}
+
+sub def_var($$) {
+	my ($line, $varname) = @_;
+	my $varcanon = varname_canon($varname);
+
+	if (defined($mkctx_vardef)) {
+		$mkctx_vardef->{$varname} = $line;
+		$mkctx_vardef->{$varcanon} = $line;
+	}
+
+	if (defined($pkgctx_vardef)) {
+		$pkgctx_vardef->{$varname} = $line;
+		$pkgctx_vardef->{$varcanon} = $line;
+	}
+}
+
+sub var_is_defined($) {
+	my ($varname) = @_;
+	my $varcanon = varname_canon($varname);
+
+	if (defined($mkctx_vardef)) {
+		return $mkctx_vardef->{$varname} if exists($mkctx_vardef->{$varname});
+		return $mkctx_vardef->{$varcanon} if exists($mkctx_vardef->{$varcanon});
+	}
+	if (defined($pkgctx_vardef)) {
+		return $pkgctx_vardef->{$varname} if exists($pkgctx_vardef->{$varname});
+		return $pkgctx_vardef->{$varcanon} if exists($pkgctx_vardef->{$varcanon});
+	}
+	return false;
+}
+
+sub determine_used_variables($) {
+	my ($lines) = @_;
+	my ($rest);
+
+	foreach my $line (@{$lines}) {
+		$rest = $line->text;
+		while ($rest =~ s/(?:\$\{|\$\(|defined\(|empty\()([0-9+.A-Z_a-z]+)[:})]//) {
+			my ($varname) = ($1);
+			use_var($line, $varname);
+			$opt_debug_unused and $line->log_debug("Variable ${varname} is used.");
+		}
+	}
+}
+
+sub extract_used_variables($$) {
+	my ($line, $text) = @_;
+	my ($rest, $result);
+
+	$rest = $text;
+	$result = [];
+	while ($rest =~ s/^(?:[^\$]+|\$[\$*<>?\@]|\$\{([.0-9A-Z_a-z]+)(?::(?:[^\${}]|\$[^{])+)?\})//) {
+		my ($varname) = ($1);
+
+		if (defined($varname)) {
+			push(@{$result}, $varname);
+		}
+	}
+
+	if ($rest ne "") {
+		$opt_debug_misc and $line->log_warning("Could not extract variables: ${rest}");
+	}
+
+	return $result;
+}
+
+sub get_nbpart() {
+	my $line = $pkgctx_vardef->{"PKGREVISION"};
+	return "" unless defined($line);
+	my $pkgrevision = $line->get("value");
+	return "" unless $pkgrevision =~ m"^\d+$";
+	return "" unless $pkgrevision + 0 != 0;
+	return "nb$pkgrevision";
+}
+
+sub check_pkglint_version() {
+	state $done = false;
+	return if $done;
+	$done = true;
+
+	my $lines = load_lines("${cwd_pkgsrcdir}/pkgtools/pkglint/Makefile", true);
+	return unless $lines;
+
+	my $pkglint_version = undef;
+	foreach my $line (@{$lines}) {
+		if ($line->text =~ regex_varassign) {
+			my ($varname, undef, $value, undef) = ($1, $2, $3, $4);
+
+			if ($varname eq "DISTNAME" || $varname eq "PKGNAME") {
+				if ($value =~ regex_pkgname) {
+					$pkglint_version = $2;
+				}
+			}
+		}
+	}
+	return unless defined($pkglint_version);
+
+	if (dewey_cmp($pkglint_version, ">", conf_distver)) {
+		log_note(NO_FILE, NO_LINE_NUMBER, "A newer version of pkglint is available.");
+	} elsif (dewey_cmp($pkglint_version, "<", conf_distver)) {
+		log_error(NO_FILE, NO_LINE_NUMBER, "The pkglint version is newer than the tree to check.");
+	}
+}
+
+# When processing a file using the expect* subroutines below, it may
+# happen that $lineno points past the end of the file. In that case,
+# print the warning without associated source code.
+sub lines_log_warning($$$) {
+	my ($lines, $lineno, $msg) = @_;
+
+	assert(false, "The line number is negative (${lineno}).")
+		unless 0 <= $lineno;
+	assert(@{$lines} != 0, "The lines may not be empty.");
+
+	if ($lineno <= $#{$lines}) {
+		$lines->[$lineno]->log_warning($msg);
+	} else {
+		log_warning($lines->[0]->fname, "EOF", $msg);
+	}
+}
+
+# Checks if the current line ($lines->{${$lineno_ref}}) matches the
+# regular expression, and if it does, increments ${${lineno_ref}}.
+# @param $lines
+#	The lines that are checked.
+# @param $lineno_ref
+#	A reference to the line number, an integer variable.
+# @param $regex
+#	The regular expression to be checked.
+# @return
+#	The result of the regular expression match or false.
+sub expect($$$) {
+	my ($lines, $lineno_ref, $regex) = @_;
+	my $lineno = ${$lineno_ref};
+
+	if ($lineno <= $#{$lines} && $lines->[$lineno]->text =~ $regex) {
+		${$lineno_ref}++;
+		return PkgLint::SimpleMatch->new($lines->[$lineno]->text, \@-, \@+);
+	} else {
+		return false;
+	}
+}
+
+sub expect_empty_line($$) {
+	my ($lines, $lineno_ref) = @_;
+
+	if (expect($lines, $lineno_ref, qr"^$")) {
+		return true;
+	} else {
+		$opt_warn_space and $lines->[${$lineno_ref}]->log_note("Empty line expected.");
+		return false;
+	}
+}
+
+sub expect_text($$$) {
+	my ($lines, $lineno_ref, $text) = @_;
+
+	my $rv = expect($lines, $lineno_ref, qr"^\Q${text}\E$");
+	$rv or lines_log_warning($lines, ${$lineno_ref}, "Expected \"${text}\".");
+	return $rv;
+}
+
+sub expect_re($$$) {
+	my ($lines, $lineno_ref, $re) = @_;
+
+	my $rv = expect($lines, $lineno_ref, $re);
+	$rv or lines_log_warning($lines, ${$lineno_ref}, "Expected text matching $re.");
+	return $rv;
+}
+
+# Returns an object of type Pkglint::Type that represents the type of
+# the variable (maybe guessed based on the variable name), or undef if
+# the type cannot even be guessed.
+#
+sub get_variable_type($$) {
+	my ($line, $varname) = @_;
+	my ($type);
+
+	assert(defined($varname), "The varname parameter must be defined.");
+
+	if (exists(get_vartypes_map()->{$varname})) {
+		return get_vartypes_map()->{$varname};
+	}
+
+	my $varcanon = varname_canon($varname);
+	if (exists(get_vartypes_map()->{$varcanon})) {
+		return get_vartypes_map()->{$varcanon};
+	}
+
+	if (exists(get_varname_to_toolname()->{$varname})) {
+		return PkgLint::Type->new(LK_NONE, "ShellCommand", [[ qr".*", "u" ]], NOT_GUESSED);
+	}
+
+	if ($varname =~ m"^TOOLS_(.*)" && exists(get_varname_to_toolname()->{$1})) {
+		return PkgLint::Type->new(LK_NONE, "Pathname", [[ qr".*", "u" ]], NOT_GUESSED);
+	}
+
+	use constant allow_all => [[ qr".*", "adpsu" ]];
+	use constant allow_runtime => [[ qr".*", "adsu" ]];
+
+	# Guess the datatype of the variable based on
+	# naming conventions.
+	$type =	  ($varname =~ m"DIRS$") ? PkgLint::Type->new(LK_EXTERNAL, "Pathmask", allow_runtime, GUESSED)
+		: ($varname =~ m"(?:DIR|_HOME)$") ? PkgLint::Type->new(LK_NONE, "Pathname", allow_runtime, GUESSED)
+		: ($varname =~ m"FILES$") ? PkgLint::Type->new(LK_EXTERNAL, "Pathmask", allow_runtime, GUESSED)
+		: ($varname =~ m"FILE$") ? PkgLint::Type->new(LK_NONE, "Pathname", allow_runtime, GUESSED)
+		: ($varname =~ m"PATH$") ? PkgLint::Type->new(LK_NONE, "Pathlist", allow_runtime, GUESSED)
+		: ($varname =~ m"PATHS$") ? PkgLint::Type->new(LK_EXTERNAL, "Pathname", allow_runtime, GUESSED)
+		: ($varname =~ m"_USER$") ? PkgLint::Type->new(LK_NONE, "UserGroupName", allow_all, GUESSED)
+		: ($varname =~ m"_GROUP$") ? PkgLint::Type->new(LK_NONE, "UserGroupName", allow_all, GUESSED)
+		: ($varname =~ m"_ENV$") ? PkgLint::Type->new(LK_EXTERNAL, "ShellWord", allow_runtime, GUESSED)
+		: ($varname =~ m"_CMD$") ? PkgLint::Type->new(LK_NONE, "ShellCommand", allow_runtime, GUESSED)
+		: ($varname =~ m"_ARGS$") ? PkgLint::Type->new(LK_EXTERNAL, "ShellWord", allow_runtime, GUESSED)
+		: ($varname =~ m"_(?:C|CPP|CXX|LD|)FLAGS$") ? PkgLint::Type->new(LK_EXTERNAL, "ShellWord", allow_runtime, GUESSED)
+		: ($varname =~ m"_MK$") ? PkgLint::Type->new(LK_NONE, "Unchecked", allow_all, GUESSED)
+		: ($varname =~ m"^PLIST.") ? PkgLint::Type->new(LK_NONE, "Yes", allow_all, GUESSED)
+		: undef;
+
+	if (defined($type)) {
+		$opt_debug_vartypes and $line->log_debug("The guessed type of ${varname} is \"" . $type->to_string . "\".");
+		return $type;
+	}
+
+	$opt_debug_vartypes and $line->log_debug("No type definition found for ${varcanon}.");
+	return undef;
+}
+
+sub get_variable_perms($$) {
+	my ($line, $varname) = @_;
+
+	my $type = get_variable_type($line, $varname);
+	if (!defined($type)) {
+		$opt_debug_misc and $line->log_debug("No type definition found for ${varname}.");
+		return "adpsu";
+	}
+
+	my $perms = $type->perms($line->fname, $varname);
+	if (!defined($perms)) {
+		$opt_debug_misc and $line->log_debug("No permissions specified for ${varname}.");
+		return "?";
+	}
+	return $perms;
+}
+
+# This function returns whether a variable needs the :Q operator in a
+# certain context. There are four possible outcomes:
+#
+# false:	The variable should not be quoted.
+# true:		The variable should be quoted.
+# doesnt_matter:
+#		Since the values of the variable usually don't contain
+#		special characters, it does not matter whether the
+#		variable is quoted or not.
+# dont_know:	pkglint cannot say whether the variable should be quoted
+#		or not, most likely because type information is missing.
+#
+sub variable_needs_quoting($$$) {
+	my ($line, $varname, $context) = @_;
+	my $type = get_variable_type($line, $varname);
+	my ($want_list, $have_list);
+
+	$opt_debug_trace and $line->log_debug("variable_needs_quoting($varname, " . $context->to_string() . ")");
+
+	use constant safe_types => array_to_hash(qw(
+		DistSuffix
+		FileMode Filename
+		Identifier
+		Option
+		Pathname PkgName PkgOptionsVar PkgRevision
+		RelativePkgDir RelativePkgPath
+		UserGroupName
+		Varname Version
+		WrkdirSubdirectory
+	));
+
+	if (!defined($type) || !defined($context->type)) {
+		return dont_know;
+	}
+
+	# Variables of certain predefined types, as well as all
+	# enumerations, are expected to not require the :Q operator.
+	if (ref($type->basic_type) eq "HASH" || exists(safe_types->{$type->basic_type})) {
+		if ($type->kind_of_list == LK_NONE) {
+			return doesnt_matter;
+
+		} elsif ($type->kind_of_list == LK_EXTERNAL && $context->extent != VUC_EXTENT_WORD_PART) {
+			return false;
+		}
+	}
+
+	# In .for loops, the :Q operator is always misplaced, since
+	# the items are broken up at white-space, not as shell words
+	# like in all other parts of make(1).
+	if ($context->shellword == VUC_SHELLWORD_FOR) {
+		return false;
+	}
+
+	# Determine whether the context expects a list of shell words or
+	# not.
+	$want_list = $context->type->is_practically_a_list() && ($context->shellword == VUC_SHELLWORD_BACKT || $context->extent != VUC_EXTENT_WORD_PART);
+	$have_list = $type->is_practically_a_list();
+
+	$opt_debug_quoting and $line->log_debug("[variable_needs_quoting]"
+		. " varname=$varname"
+		. " context=" . $context->to_string()
+		. " type=" . $type->to_string()
+		. " want_list=" . ($want_list ? "yes" : "no")
+		. " have_list=" . ($have_list ? "yes" : "no")
+		. ".");
+
+	# A shell word may appear as part of a shell word, for example
+	# COMPILER_RPATH_FLAG.
+	if ($context->extent == VUC_EXTENT_WORD_PART && $context->shellword == VUC_SHELLWORD_PLAIN) {
+		if ($type->kind_of_list == LK_NONE && $type->basic_type eq "ShellWord") {
+			return false;
+		}
+	}
+
+	# Assume that the tool definitions don't include very special
+	# characters, so they can safely be used inside any quotes.
+	if (exists(get_varname_to_toolname()->{$varname})) {
+		my $sw = $context->shellword;
+
+		if ($sw == VUC_SHELLWORD_PLAIN && $context->extent != VUC_EXTENT_WORD_PART) {
+			return false;
+
+		} elsif ($sw == VUC_SHELLWORD_BACKT) {
+			return false;
+
+		} elsif ($sw == VUC_SHELLWORD_DQUOT || $sw == VUC_SHELLWORD_SQUOT) {
+			return doesnt_matter;
+
+		} else {
+			# Let the other rules decide.
+		}
+	}
+
+	# Variables that appear as parts of shell words generally need
+	# to be quoted. An exception is in the case of backticks,
+	# because the whole backticks expression is parsed as a single
+	# shell word by pkglint.
+	#
+	# XXX: When the shell word parser gets rewritten the next time,
+	# this test can be refined.
+	if ($context->extent == VUC_EXTENT_WORD_PART && $context->shellword != VUC_SHELLWORD_BACKT) {
+		return true;
+	}
+
+	# Assigning lists to lists does not require any quoting, though
+	# there may be cases like "CONFIGURE_ARGS+= -libs ${LDFLAGS:Q}"
+	# where quoting is necessary. So let's hope that no developer
+	# ever makes the mistake of using :Q when appending a list to
+	# a list.
+	if ($want_list && $have_list) {
+		return doesnt_matter;
+	}
+
+	# Appending elements to a list requires quoting, as well as
+	# assigning a list value to a non-list variable.
+	if ($want_list != $have_list) {
+		return true;
+	}
+
+	$opt_debug_quoting and $line->log_debug("Don't know whether :Q is needed for ${varname}.");
+	return dont_know;
+}
+
+#
+# Parsing.
+#
+
+# Checks whether $tree matches $pattern, and if so, instanciates the
+# variables in $pattern. If they don't match, some variables may be
+# instanciated nevertheless, but the exact behavior is unspecified.
+#
+sub tree_match($$);
+sub tree_match($$) {
+	my ($tree, $pattern) = @_;
+
+	my $d1 = Data::Dumper->new([$tree, $pattern])->Terse(true)->Indent(0);
+	my $d2 = Data::Dumper->new([$pattern])->Terse(true)->Indent(0);
+	$opt_debug_trace and log_debug(NO_FILE, NO_LINES, sprintf("tree_match(%s, %s)", $d1->Dump, $d2->Dump));
+
+	return true if (!defined($tree) && !defined($pattern));
+	return false if (!defined($tree) || !defined($pattern));
+	my $aref = ref($tree);
+	my $pref = ref($pattern);
+	if ($pref eq "SCALAR" && !defined($$pattern)) {
+		$$pattern = $tree;
+		return true;
+	}
+	if ($aref eq "" && ($pref eq "" || $pref eq "SCALAR")) {
+		return $tree eq $pattern;
+	}
+	if ($aref eq "ARRAY" && $pref eq "ARRAY") {
+		return false if scalar(@$tree) != scalar(@$pattern);
+		for (my $i = 0; $i < scalar(@$tree); $i++) {
+			return false unless tree_match($tree->[$i], $pattern->[$i]);
+		}
+		return true;
+	}
+	return false;
+}
+
+# TODO: Needs to be redesigned to handle more complex expressions.
+sub parse_mk_cond($$);
+sub parse_mk_cond($$) {
+	my ($line, $cond) = @_;
+
+	$opt_debug_trace and $line->log_debug("parse_mk_cond(\"${cond}\")");
+
+	my $re_simple_varname = qr"[A-Z_][A-Z0-9_]*(?:\.[\w_+\-]+)?";
+	while ($cond ne "") {
+		if ($cond =~ s/^!//) {
+			return ["not", parse_mk_cond($line, $cond)];
+		} elsif ($cond =~ s/^defined\((${re_simple_varname})\)$//) {
+			return ["defined", $1];
+		} elsif ($cond =~ s/^empty\((${re_simple_varname})\)$//) {
+			return ["empty", $1];
+		} elsif ($cond =~ s/^empty\((${re_simple_varname}):M([^\$:{})]+)\)$//) {
+			return ["empty", ["match", $1, $2]];
+		} elsif ($cond =~ s/^\$\{(${re_simple_varname})\}\s+(==|!=)\s+"([^"\$\\]*)"$//) {
+			return [$2, ["var", $1], ["string", $3]];
+		} else {
+			$opt_debug_unchecked and $line->log_debug("parse_mk_cond: ${cond}");
+			return ["unknown", $cond];
+		}
+	}
+}
+
+sub parse_licenses($) {
+	my ($licenses) = @_;
+
+	$licenses =~ s,\$\{PERL5_LICENSE},gnu-gpl-v2 OR artistic,g;
+	$licenses =~ s,[()]|AND|OR,,g; # XXX: treats OR like AND
+	my @licenses = split(/\s+/, $licenses);
+	return \@licenses;
+}
+
+# This procedure fills in the extra fields of a line, depending on the
+# line type. These fields can later be queried without having to parse
+# them again and again.
+#
+sub parseline_mk($) {
+	my ($line) = @_;
+	my $text = $line->text;
+
+	if ($text =~ regex_varassign) {
+		my ($varname, $op, $value, $comment) = ($1, $2, $3, $4);
+
+		# In variable assignments, a '#' character is preceded
+		# by a backslash. In shell commands, it is interpreted
+		# literally.
+		$value =~ s/\\\#/\#/g;
+
+		$line->set("is_varassign", true);
+		$line->set("varname", $varname);
+		$line->set("varcanon", varname_canon($varname));
+		my $varparam = varname_param($varname);
+		defined($varparam) and $line->set("varparam", $varparam);
+		$line->set("op", $op);
+		$line->set("value", $value);
+		defined($comment) and $line->set("comment", $comment);
+
+	} elsif ($text =~ regex_mk_shellcmd) {
+		my ($shellcmd) = ($1);
+
+		# Shell command lines cannot have embedded comments.
+		$line->set("is_shellcmd", true);
+		$line->set("shellcmd", $shellcmd);
+
+		my ($shellwords, $rest) = match_all($shellcmd, $regex_shellword);
+		$line->set("shellwords", $shellwords);
+		if ($rest !~ m"^\s*$") {
+			$line->set("shellwords_rest", $rest);
+		}
+
+	} elsif ($text =~ regex_mk_comment) {
+		my ($comment) = ($1);
+
+		$line->set("is_comment", true);
+		$line->set("comment", $comment);
+
+	} elsif ($text =~ m"^\s*$") {
+
+		$line->set("is_empty", true);
+
+	} elsif ($text =~ regex_mk_cond) {
+		my ($indent, $directive, $args, $comment) = ($1, $2, $3, $4);
+
+		$line->set("is_cond", true);
+		$line->set("indent", $indent);
+		$line->set("directive", $directive);
+		defined($args) and $line->set("args", $args);
+		defined($comment) and $line->set("comment", $comment);
+
+	} elsif ($text =~ regex_mk_include) {
+		my (undef, $includefile, $comment) = ($1, $2, $3);
+
+		$line->set("is_include", true);
+		$line->set("includefile", $includefile);
+		defined($comment) and $line->set("comment", $comment);
+
+	} elsif ($text =~ regex_mk_sysinclude) {
+		my ($includefile, $comment) = ($1, $2);
+
+		$line->set("is_sysinclude", true);
+		$line->set("includefile", $includefile);
+		defined($comment) and $line->set("comment", $comment);
+
+	} elsif ($text =~ regex_mk_dependency) {
+		my ($targets, $whitespace, $sources, $comment) = ($1, $2, $3, $4);
+
+		$line->set("is_dependency", true);
+		$line->set("targets", $targets);
+		$line->set("sources", $sources);
+		$line->log_warning("Space before colon in dependency line: " . $line->to_string()) if ($whitespace);
+		defined($comment) and $line->set("comment", $comment);
+
+	} elsif ($text =~ regex_rcs_conflict) {
+		# This line is useless
+
+	} else {
+		$line->log_fatal("Unknown line format: " . $line->to_string());
+	}
+}
+
+sub parselines_mk($) {
+	my ($lines) = @_;
+
+	foreach my $line (@{$lines}) {
+		parseline_mk($line);
+	}
+}
+
+#
+# Loading package-specific data from files.
+#
+
+sub readmakefile($$$$);
+sub readmakefile($$$$) {
+	my ($fname, $main_lines, $all_lines, $seen_Makefile_include) = @_;
+	my ($includefile, $dirname, $lines, $is_main_Makefile);
+
+	$lines = load_lines($fname, true);
+	if (!$lines) {
+		return false;
+	}
+	parselines_mk($lines);
+
+	$is_main_Makefile = (@{$main_lines} == 0);
+
+	foreach my $line (@{$lines}) {
+		my $text = $line->text;
+
+		if ($is_main_Makefile) {
+			push(@{$main_lines}, $line);
+		}
+		push(@{$all_lines}, $line);
+
+		# try to get any included file
+		my $is_include_line = false;
+		if ($text =~ m"^\.\s*include\s+\"(.*)\"$") {
+			$includefile = resolve_relative_path($1, true);
+			if ($includefile =~ regex_unresolved) {
+				if ($fname !~ m"/mk/") {
+					$line->log_note("Skipping include file \"${includefile}\". This may result in false warnings.");
+				}
+
+			} else {
+				$is_include_line = true;
+			}
+		}
+
+		if ($is_include_line) {
+			if ($fname !~ m"buildlink3\.mk$" && $includefile =~ m"^\.\./\.\./(.*)/buildlink3\.mk$") {
+				my ($bl3_file) = ($1);
+
+				$pkgctx_bl3->{$bl3_file} = $line;
+				$opt_debug_misc and $line->log_debug("Buildlink3 file in package: ${bl3_file}");
+			}
+		}
+
+		if ($is_include_line && !exists($seen_Makefile_include->{$includefile})) {
+			$seen_Makefile_include->{$includefile} = true;
+
+			if ($includefile =~ m"^\.\./[^./][^/]*/[^/]+") {
+				$line->log_warning("Relative directories should look like \"../../category/package\", not \"../package\".");
+				$line->explain_warning(expl_relative_dirs);
+			}
+			if ($includefile =~ m"(?:^|/)Makefile.common$"
+			    || ($includefile =~ m"^(?:\.\./(\.\./[^/]+/)?[^/]+/)?([^/]+)$"
+				&& (!defined($1) || $1 ne "../mk")
+				&& $2 ne "buildlink3.mk"
+				&& $2 ne "options.mk")) {
+				$opt_debug_include and $line->log_debug("including ${includefile} sets seen_Makefile_common.");
+				$seen_Makefile_common = true;
+			}
+			if ($includefile =~ m"/mk/") {
+				# skip these files
+
+			} else {
+				$dirname = dirname($fname);
+				# Only look in the directory relative to the
+				# current file and in the current working directory.
+				# We don't have an include dir list, like make(1) does.
+				if (!-f "$dirname/$includefile") {
+					$dirname = $current_dir;
+				}
+				if (!-f "$dirname/$includefile") {
+					$line->log_error("Cannot read $dirname/$includefile.");
+				} else {
+					$opt_debug_include and $line->log_debug("Including \"$dirname/$includefile\".");
+					my $last_lineno = $#{$all_lines};
+					readmakefile("$dirname/$includefile", $main_lines, $all_lines, $seen_Makefile_include) or return false;
+
+					# Check that there is a comment in each
+					# Makefile.common that says which files
+					# include it.
+					if ($includefile =~ m"/Makefile\.common$") {
+						my @mc_lines = @{$all_lines}[$last_lineno+1 .. $#{$all_lines}];
+						my $expected = "# used by " . relative_path($cwd_pkgsrcdir, $fname);
+
+						if (!(grep { $_->text eq $expected } @mc_lines)) {
+							my $lineno = 0;
+							while ($lineno < $#mc_lines && $mc_lines[$lineno]->has("is_comment")) {
+								$lineno++;
+							}
+							my $iline = $mc_lines[$lineno];
+							$iline->log_warning("Please add a line \"$expected\" here.");
+							$iline->explain_warning(
+"Since Makefile.common files usually don't have any comments and",
+"therefore not a clearly defined interface, they should at least contain",
+"references to all files that include them, so that it is easier to see",
+"what effects future changes may have.",
+"",
+"If there are more than five packages that use a Makefile.common,",
+"you should think about giving it a proper name (maybe plugin.mk) and",
+"documenting its interface.");
+							$iline->append_before($expected);
+							autofix(\@mc_lines);
+						}
+					}
+				}
+			}
+
+		} elsif ($line->has("is_varassign")) {
+			my ($varname, $op, $value) = ($line->get("varname"), $line->get("op"), $line->get("value"));
+
+			# Record all variables that are defined in these lines, so that they
+			# are not reported as "used but not defined".
+			if ($op ne "?=" || !exists($pkgctx_vardef->{$varname})) {
+				$opt_debug_misc and $line->log_debug("varassign(${varname}, ${op}, ${value})");
+				$pkgctx_vardef->{$varname} = $line;
+			}
+		}
+	}
+
+	return true;
+}
+
+sub load_package_Makefile($$) {
+	my ($fname, $ref_lines) = @_;
+	my ($subr) = "load_package_Makefile";
+	my ($lines, $all_lines, $seen_php_pecl_version);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "load_package_Makefile()");
+
+	if (!readmakefile($fname, $lines = [], $all_lines = [], $pkgctx_included = {})) {
+		log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+		return false;
+	}
+
+	if ($opt_dumpmakefile) {
+		log_debug(NO_FILE, NO_LINES, "Whole Makefile (with all included files) follows:");
+		foreach my $line (@{$all_lines}) {
+			print($line->to_string() . "\n");
+		}
+	}
+
+	determine_used_variables($all_lines);
+
+	$pkgdir = expand_variable("PKGDIR");
+	set_default_value(\$pkgdir, ".");
+	$distinfo_file = expand_variable("DISTINFO_FILE");
+	set_default_value(\$distinfo_file, "distinfo");
+	$filesdir = expand_variable("FILESDIR");
+	set_default_value(\$filesdir, "files");
+	$patchdir = expand_variable("PATCHDIR");
+	set_default_value(\$patchdir, "patches");
+
+	if (var_is_defined("PHPEXT_MK")) {
+		if (!var_is_defined("USE_PHP_EXT_PATCHES")) {
+			$patchdir = "patches";
+		}
+		if (var_is_defined("PECL_VERSION")) {
+			$distinfo_file = "distinfo";
+		}
+	}
+
+	$opt_debug_misc and log_debug(NO_FILE, NO_LINE_NUMBER, "[${subr}] DISTINFO_FILE=$distinfo_file");
+	$opt_debug_misc and log_debug(NO_FILE, NO_LINE_NUMBER, "[${subr}] FILESDIR=$filesdir");
+	$opt_debug_misc and log_debug(NO_FILE, NO_LINE_NUMBER, "[${subr}] PATCHDIR=$patchdir");
+	$opt_debug_misc and log_debug(NO_FILE, NO_LINE_NUMBER, "[${subr}] PKGDIR=$pkgdir");
+
+	${$ref_lines} = $lines;
+	return true;
+}
+
+sub warn_about_PLIST_imake_mannewsuffix($) {
+	my ($line) = @_;
+
+	$line->log_warning("IMAKE_MANNEWSUFFIX is not meant to appear in PLISTs.");
+	$line->explain_warning(
+"This is the result of a print-PLIST call that has _not_ been checked",
+"thoroughly by the developer. Please replace the IMAKE_MANNEWSUFFIX with",
+"",
+"\tIMAKE_MAN_SUFFIX for programs,",
+"\tIMAKE_LIBMAN_SUFFIX for library functions,",
+"\tIMAKE_FILEMAN_SUFFIX for file formats,",
+"\tIMAKE_GAMEMAN_SUFFIX for games,",
+"\tIMAKE_MISCMAN_SUFFIX for other man pages.");
+}
+
+#
+# Subroutines to check part of a single line.
+#
+
+sub checkword_absolute_pathname($$) {
+	my ($line, $word) = @_;
+
+	$opt_debug_trace and $line->log_debug("checkword_absolute_pathname(\"${word}\")");
+
+	if ($word =~ m"^/dev/(?:null|tty|zero)$") {
+		# These are defined by POSIX.
+
+	} elsif ($word eq "/bin/sh") {
+		# This is usually correct, although on Solaris, it's pretty
+		# feature-crippled.
+
+	} elsif ($word !~ m"/(?:[a-z]|\$[({])") {
+		# Assume that all pathnames start with a lowercase letter.
+
+	} else {
+		$line->log_warning("Found absolute pathname: ${word}");
+		$line->explain_warning(
+"Absolute pathnames are often an indicator for unportable code. As",
+"pkgsrc aims to be a portable system, absolute pathnames should be",
+"avoided whenever possible.",
+"",
+"A special variable in this context is \${DESTDIR}, which is used in GNU",
+"projects to specify a different directory for installation than what",
+"the programs see later when they are executed. Usually it is empty, so",
+"if anything after that variable starts with a slash, it is considered",
+"an absolute pathname.");
+	}
+}
+
+sub check_unused_licenses() {
+
+	for my $licensefile (glob("${cwd_pkgsrcdir}/licenses/*")) {
+		if (-f $licensefile) {
+			my $licensename = basename($licensefile);
+			if (!exists($ipc_used_licenses{$licensename})) {
+				log_warning($licensefile, NO_LINES, "This license seems to be unused.");
+			}
+		}
+	}
+}
+
+sub checkpackage_possible_downgrade() {
+
+	$opt_debug_trace and log_debug(NO_FILE, NO_LINES, "checkpackage_possible_downgrade");
+
+	return unless defined $effective_pkgname;
+	return unless $effective_pkgname =~ regex_pkgname;
+	my ($pkgbase, $pkgversion) = ($1, $2);
+	my $line = $effective_pkgname_line;
+
+	my @changes = get_doc_CHANGES($pkgpath);
+	if (@changes == 0) {
+		$opt_debug_misc and $line->log_debug("No changes have been recorded for package $pkgpath.");
+		return;
+	}
+
+	my $last_change = $changes[-1];
+	return unless $last_change->action eq "Updated";
+
+	my $last_version = $last_change->version;
+
+	if (dewey_cmp($pkgversion, "<", $last_version)) {
+		$line->log_warning("The package is being downgraded from $last_version to $pkgversion.");
+	}
+}
+
+#
+# Subroutines to check a single line.
+#
+
+sub checkline_length($$) {
+	my ($line, $maxlength) = @_;
+
+	if (length($line->text) > $maxlength) {
+		$line->log_warning("Line too long (should be no more than $maxlength characters).");
+		$line->explain_warning(
+"Back in the old time, terminals with 80x25 characters were common.",
+"And this is still the default size of many terminal emulators.",
+"Moderately short lines also make reading easier.");
+	}
+}
+
+sub checkline_valid_characters($$) {
+	my ($line, $re_validchars) = @_;
+	my ($rest);
+
+	($rest = $line->text) =~ s/$re_validchars//g;
+	if ($rest ne "") {
+		my @chars = map { sprintf("0x%02x", ord($_)); } split(//, $rest);
+		$line->log_warning("Line contains invalid characters (" . join(", ", @chars) . ").");
+	}
+}
+
+sub checkline_valid_characters_in_variable($$) {
+	my ($line, $re_validchars) = @_;
+	my ($varname, $rest);
+
+	$varname = $line->get("varname");
+	$rest = $line->get("value");
+
+	$rest =~ s/$re_validchars//g;
+	if ($rest ne "") {
+		my @chars = map { sprintf("0x%02x", ord($_)); } split(//, $rest);
+		$line->log_warning("${varname} contains invalid characters (" . join(", ", @chars) . ").");
+	}
+}
+
+sub checkline_trailing_whitespace($) {
+	my ($line) = @_;
+
+	$opt_debug_trace and $line->log_debug("checkline_trailing_whitespace()");
+
+	if ($line->text =~ /\s+$/) {
+		$line->log_note("Trailing white-space.");
+		$line->explain_note(
+"When a line ends with some white-space, that space is in most cases",
+"irrelevant and can be removed, leading to a \"normal form\" syntax.",
+"",
+"Note: This is mostly for aesthetic reasons.");
+		$line->replace_regex(qr"\s+\n$", "\n");
+	}
+}
+
+sub checkline_rcsid_regex($$$) {
+	my ($line, $prefix_regex, $prefix) = @_;
+	my ($id) = ($opt_rcsidstring . ($is_wip ? "|Id" : ""));
+
+	$opt_debug_trace and $line->log_debug("checkline_rcsid_regex(${prefix_regex}, ${prefix})");
+
+	if ($line->text !~ m"^${prefix_regex}\$(${id})(?::[^\$]+|)\$$") {
+		$line->log_error("\"${prefix}\$${opt_rcsidstring}\$\" expected.");
+		$line->explain_error(
+"Several files in pkgsrc must contain the CVS Id, so that their current",
+"version can be traced back later from a binary package. This is to",
+"ensure reproducible builds, for example for finding bugs.",
+"",
+"Please insert the text from the above error message (without the quotes)",
+"at this position in the file.");
+		return false;
+	}
+	return true;
+}
+
+sub checkline_rcsid($$) {
+	my ($line, $prefix) = @_;
+
+	checkline_rcsid_regex($line, quotemeta($prefix), $prefix);
+}
+
+sub checkline_mk_absolute_pathname($$) {
+	my ($line, $text) = @_;
+	my $abspath;
+
+	$opt_debug_trace and $line->log_debug("checkline_mk_absolute_pathname(${text})");
+
+	# In the GNU coding standards, DESTDIR is defined as a (usually
+	# empty) prefix that can be used to install files to a different
+	# location from what they have been built for. Therefore
+	# everything following it is considered an absolute pathname.
+	# Another commonly used context is in assignments like
+	# "bindir=/bin".
+	if ($text =~ m"(?:^|\$\{DESTDIR\}|\$\(DESTDIR\)|[\w_]+\s*=\s*)(/(?:[^\"'\`\s]|\"[^\"*]\"|'[^']*'|\`[^\`]*\`)*)") {
+		my $path = $1;
+
+		if ($path =~ m"^/\w") {
+			$abspath = $path;
+		}
+	}
+
+	if (defined($abspath)) {
+		checkword_absolute_pathname($line, $abspath);
+	}
+}
+
+sub checkline_relative_path($$$) {
+	my ($line, $path, $must_exist) = @_;
+	my ($res_path);
+
+	if (!$is_wip && $path =~ m"/wip/") {
+		$line->log_error("A pkgsrc package must not depend on any outside package.");
+	}
+	$res_path = resolve_relative_path($path, true);
+	if ($res_path =~ regex_unresolved) {
+		$opt_debug_unchecked and $line->log_debug("Unchecked path: \"${path}\".");
+	} elsif (!-e ((($res_path =~ m"^/") ? "" : "${current_dir}/") . $res_path)) {
+		$must_exist and $line->log_error("\"${res_path}\" does not exist.");
+	} elsif ($path =~ m"^\.\./\.\./([^/]+)/([^/]+)(.*)") {
+		my ($cat, $pkg, $rest) = ($1, $2, $3);
+	} elsif ($path =~ m"^\.\./\.\./mk/") {
+		# There need not be two directory levels for mk/ files.
+	} elsif ($path =~ m"^\.\./mk/" && $cur_pkgsrcdir eq "..") {
+		# That's fine for category Makefiles.
+	} elsif ($path =~ m"^\.\.") {
+		$line->log_warning("Invalid relative path \"${path}\".");
+	}
+}
+
+sub checkline_relative_pkgdir($$) {
+	my ($line, $path) = @_;
+
+	checkline_relative_path($line, $path, true);
+	$path = resolve_relative_path($path, false);
+
+	if ($path =~ m"^(?:\./)?\.\./\.\./([^/]+/[^/]+)$") {
+		my $otherpkgpath = $1;
+		if (! -f "$cwd_pkgsrcdir/$otherpkgpath/Makefile") {
+			$line->log_error("There is no package in $otherpkgpath.");
+		}
+
+	} else {
+		$line->log_warning("\"${path}\" is not a valid relative package directory.");
+		$line->explain_warning(
+"A relative pathname always starts with \"../../\", followed",
+"by a category, a slash and a the directory name of the package.",
+"For example, \"../../misc/screen\" is a valid relative pathname.");
+	}
+}
+
+sub checkline_mk_varuse($$$$) {
+	my ($line, $varname, $mod, $context) = @_;
+
+	assert(defined($varname), "The varname parameter must be defined");
+	assert(defined($context), "The context parameter must be defined");
+	$opt_debug_trace and $line->log_debug("checkline_mk_varuse(\"${varname}\", \"${mod}\", ".$context->to_string().")");
+
+	# Check for spelling mistakes.
+	my $type = get_variable_type($line, $varname);
+	if (defined($type) && !($type->is_guessed)) {
+		# Great.
+
+	} elsif (var_is_used($varname)) {
+		# Fine.
+
+	} elsif (defined($mkctx_for_variables) && exists($mkctx_for_variables->{$varname})) {
+		# Variables defined in .for loops are also ok.
+
+	} else {
+		$opt_warn_extra and $line->log_warning("${varname} is used but not defined. Spelling mistake?");
+	}
+
+	if ($opt_warn_perm) {
+		my $perms = get_variable_perms($line, $varname);
+		my $is_load_time;	# Will the variable be used at load time?
+		my $is_indirect;	# Might the variable be used indirectly at load time,
+					# for example by assigning it to another variable
+					# which then gets evaluated?
+
+		# Don't warn about variables that are not recorded in the
+		# pkglint variable definition.
+		if (defined($context->type) && $context->type->is_guessed()) {
+			$is_load_time = false;
+
+		} elsif ($context->time == VUC_TIME_LOAD && $perms !~ m"p") {
+			$is_load_time = true;
+			$is_indirect = false;
+
+		} elsif (defined($context->type) && $context->type->perms_union() =~ m"p" && $perms !~ m"p") {
+			$is_load_time = true;
+			$is_indirect = true;
+
+		} else {
+			$is_load_time = false;
+		}
+
+		if ($is_load_time && !$is_indirect) {
+			$line->log_warning("${varname} should not be evaluated at load time.");
+			$line->explain_warning(
+"Many variables, especially lists of something, get their values",
+"incrementally. Therefore it is generally unsafe to rely on their value",
+"until it is clear that it will never change again. This point is",
+"reached when the whole package Makefile is loaded and execution of the",
+"shell commands starts, in some cases earlier.",
+"",
+"Additionally, when using the \":=\" operator, each \$\$ is replaced",
+"with a single \$, so variables that have references to shell variables",
+"or regular expressions are modified in a subtle way.");
+		}
+		if ($is_load_time && $is_indirect) {
+			$line->log_warning("${varname} should not be evaluated indirectly at load time.");
+			$line->explain_warning(
+"The variable on the left-hand side may be evaluated at load time, but",
+"the variable on the right-hand side may not. Due to this assignment, it",
+"might be used indirectly at load-time, when it is not guaranteed to be",
+"properly defined.");
+		}
+
+		if ($perms !~ m"p" && $perms !~ m"u") {
+			$line->log_warning("${varname} may not be used in this file.");
+		}
+	}
+
+	if ($varname eq "LOCALBASE" && !$is_internal) {
+		$line->log_warning("The LOCALBASE variable should not be used by packages.");
+		$line->explain_warning(
+# from jlam via private mail.
+"Currently, LOCALBASE is typically used in these cases:",
+"",
+"(1) To locate a file or directory from another package.",
+"(2) To refer to own files after installation.",
+"",
+"In the first case, the example is:",
+"",
+"	STRLIST=        \${LOCALBASE}/bin/strlist",
+"	do-build:",
+"		cd \${WRKSRC} && \${STRLIST} *.str",
+"",
+"This should really be:",
+"",
+"	EVAL_PREFIX=    STRLIST_PREFIX=strlist",
+"	STRLIST=        \${STRLIST_PREFIX}/bin/strlist",
+"	do-build:",
+"		cd \${WRKSRC} && \${STRLIST} *.str",
+"",
+"In the second case, the example is:",
+"",
+"	CONFIGURE_ENV+= --with-datafiles=\${LOCALBASE}/share/battalion",
+"",
+"This should really be:",
+"",
+"	CONFIGURE_ENV+= --with-datafiles=\${PREFIX}/share/battalion");
+	}
+
+	my $needs_quoting = variable_needs_quoting($line, $varname, $context);
+
+	if ($context->shellword == VUC_SHELLWORD_FOR) {
+		if (!defined($type)) {
+			# Cannot check anything here.
+
+		} elsif ($type->kind_of_list == LK_INTERNAL) {
+			# Fine.
+
+		} elsif ($needs_quoting == doesnt_matter || $needs_quoting == false) {
+			# Fine, these variables are assumed to not
+			# contain special characters.
+
+		} else {
+			$line->log_warning("The variable ${varname} should not be used in .for loops.");
+			$line->explain_warning(
+"The .for loop splits its argument at sequences of white-space, as",
+"opposed to all other places in make(1), which act like the shell.",
+"Therefore only variables that are specifically designed to match this",
+"requirement should be used here.");
+		}
+	}
+
+	if ($opt_warn_quoting && $context->shellword != VUC_SHELLWORD_UNKNOWN && $needs_quoting != dont_know) {
+
+		# In GNU configure scripts, a few variables need to be
+		# passed through the :M* operator before they reach the
+		# configure scripts.
+		my $need_mstar = false;
+		if ($varname =~ regex_gnu_configure_volatile_vars) {
+			# When we are not checking a package, but some other file,
+			# the :M* operator is needed for safety.
+			if (!defined($pkgctx_vardef) || exists($pkgctx_vardef->{"GNU_CONFIGURE"})) {
+				$need_mstar = true;
+			}
+		}
+
+		my $stripped_mod = ($mod =~ m"(.*?)(?::M\*)?(?::Q)?$") ? $1 : $mod;
+		my $correct_mod = $stripped_mod . ($need_mstar ? ":M*:Q" : ":Q");
+
+		if ($mod eq ":M*:Q" && !$need_mstar) {
+			$line->log_note("The :M* modifier is not needed here.");
+
+		} elsif ($mod ne $correct_mod && $needs_quoting == true) {
+			if ($context->shellword == VUC_SHELLWORD_PLAIN) {
+				$line->log_warning("Please use \${${varname}${correct_mod}} instead of \${${varname}${mod}}.");
+				#$line->replace("\${${varname}}", "\${${varname}:Q}");
+			} else {
+				$line->log_warning("Please use \${${varname}${correct_mod}} instead of \${${varname}${mod}} and make sure the variable appears outside of any quoting characters.");
+			}
+			$line->explain_warning("See the pkgsrc guide, section \"quoting guideline\", for details.");
+		}
+
+		if ($mod =~ m":Q$") {
+			my @expl = (
+"Many variables in pkgsrc do not need the :Q operator, since they",
+"are not expected to contain white-space or other evil characters.",
+"",
+"Another case is when a variable of type ShellWord appears in a context",
+"that expects a shell word, it does not need to have a :Q operator. Even",
+"when it is concatenated with another variable, it still stays _one_ word.",
+"",
+"Example:",
+"\tWORD1=  Have\\ fun             # 1 word",
+"\tWORD2=  \"with BSD Make\"       # 1 word, too",
+"",
+"\tdemo:",
+"\t\techo \${WORD1}\${WORD2} # still 1 word");
+
+			if ($needs_quoting == false) {
+				$line->log_warning("The :Q operator should not be used for \${${varname}} here.");
+				$line->explain_warning(@expl);
+			} elsif ($needs_quoting == doesnt_matter) {
+				$line->log_note("The :Q operator isn't necessary for \${${varname}} here.");
+				$line->explain_note(@expl);
+			}
+		}
+	}
+
+	assert(defined($mkctx_build_defs), "The build_defs variable must be defined here.");
+	if (exists(get_userdefined_variables()->{$varname}) && !exists(get_system_build_defs()->{$varname}) && !exists($mkctx_build_defs->{$varname})) {
+		$line->log_warning("The user-defined variable ${varname} is used but not added to BUILD_DEFS.");
+		$line->explain_warning(
+"When a pkgsrc package is built, many things can be configured by the",
+"pkgsrc user in the mk.conf file. All these configurations should be",
+"recorded in the binary package, so the package can be reliably rebuilt.",
+"The BUILD_DEFS variable contains a list of all these user-settable",
+"variables, so please add your variable to it, too.");
+	}
+}
+
+sub checkline_mk_text($$) {
+	my ($line, $text) = @_;
+	my ($rest, $state, $vartools, $depr_map);
+
+	if ($text =~ m"^(?:[^#]*[^\$])?\$(\w+)") {
+		my ($varname) = ($1);
+		$line->log_warning("\$$varname is ambiguous. Use \${$varname} if you mean a Makefile variable or \$\$$varname if you mean a shell variable.");
+	}
+
+	if ($line->lines eq "1") {
+		checkline_rcsid_regex($line, qr"#\s+", "# ");
+	}
+
+	if ($text =~ m"\$\{WRKSRC\}/\.\./") {
+		$line->log_warning("Using \"\${WRKSRC}/..\" is conceptually wrong. Please use a combination of WRKSRC, CONFIGURE_DIRS and BUILD_DIRS instead.");
+		$line->explain_warning(
+"You should define WRKSRC such that all of CONFIGURE_DIRS, BUILD_DIRS",
+"and INSTALL_DIRS are subdirectories of it.");
+	}
+
+	if ($text =~ m"\b(-Wl,--rpath,|-Wl,-rpath-link,|-Wl,-rpath,|-Wl,-R)\b") {
+		$line->log_warning("Please use \${COMPILER_RPATH_FLAG} instead of $1.");
+	}
+	# Note: A simple -R is not detected, as the rate of false
+	# positives is too high.
+
+	$rest = $text;
+	$depr_map = get_deprecated_map();
+	while ($rest =~ s/(?:^|[^\$])\$\{([-A-Z0-9a-z_]+)(\.[\-0-9A-Z_a-z]+)?(?::[^\}]+)?\}//) {
+		my ($varbase, $varext) = ($1, $2);
+		my $varname = $varbase . (defined($varext) ? $varext : "");
+		my $varcanon = varname_canon($varname);
+		my $instead =
+		      (exists($depr_map->{$varname})) ? $depr_map->{$varname}
+		    : (exists($depr_map->{$varcanon})) ? $depr_map->{$varcanon}
+		    : undef;
+
+		if (defined($instead)) {
+			$line->log_warning("Use of ${varname} is deprecated. ${instead}");
+		}
+	}
+
+	# Don't enforce purely aesthetic changes before more correct behaviour is implemented:
+	# $rest = $text;
+	# while ($rest =~ s/(?:^|[^\$])\$\(([-A-Z0-9a-z_]+)(?::[^\}]+)?\)//) {
+	# 	my ($varname) = ($1);
+
+	# 	$line->log_warning("Please use \${${varname}\} instead of \$(${varname}).");
+	# }
+
+}
+
+#include PkgLint/Shell.pm
+
+sub expand_permission($) {
+    my ($perm) = @_;
+    my %fullperm = ( "a" => "append", "d" => "default", "p" => "preprocess", "s" => "set", "u" => "runtime", "?" => "unknown" );
+    my $result = join(", ", map { $fullperm{$_} } split //, $perm);
+    $result =~ s/, $//g;
+
+    return $result;
+}
+
+sub checkline_mk_vardef($$$) {
+	my ($line, $varname, $op) = @_;
+
+	$opt_debug_trace and $line->log_debug("checkline_mk_vardef(${varname}, ${op})");
+
+	# If we are checking a whole package, add it to the package-wide
+	# list of defined variables.
+	if (defined($pkgctx_vardef) && !exists($pkgctx_vardef->{$varname})) {
+		$pkgctx_vardef->{$varname} = $line;
+	}
+
+	# Add it to the file-wide list of defined variables.
+	if (!exists($mkctx_vardef->{$varname})) {
+		$mkctx_vardef->{$varname} = $line;
+	}
+
+	return unless $opt_warn_perm;
+
+	my $perms = get_variable_perms($line, $varname);
+	my $needed = { "=" => "s", "!=" => "s", "?=" => "d", "+=" => "a", ":=" => "s" }->{$op};
+	if (index($perms, $needed) == -1) {
+		$line->log_warning("Permission [" . expand_permission($needed) . "] requested for ${varname}, but only [" . expand_permission($perms) . "] is allowed.");
+		$line->explain_warning(
+"The available permissions are:",
+"\tappend\t\tappend something using +=",
+"\tdefault\t\tset a default value using ?=",
+"\tpreprocess\tuse a variable during preprocessing",
+"\truntime\t\tuse a variable at runtime",
+"\tset\t\tset a variable using :=, =, !=",
+"",
+"A \"?\" means that it is not yet clear which permissions are allowed",
+"and which aren't.");
+	}
+}
+
+# @param $op
+#	The operator that is used for reading or writing to the variable.
+#	One of: "=", "+=", ":=", "!=", "?=", "use", "pp-use", "".
+#	For some variables (like BuildlinkDepth or BuildlinkPackages), the
+#	operator influences the valid values.
+# @param $comment
+#	In assignments, a part of the line may be commented out. If there
+#	is no comment, pass C<undef>.
+#
+sub checkline_mk_vartype_basic($$$$$$$$);
+sub checkline_mk_vartype_basic($$$$$$$$) {
+	my ($line, $varname, $type, $op, $value, $comment, $list_context, $is_guessed) = @_;
+	my ($value_novar);
+
+	$opt_debug_trace and $line->log_debug(sprintf("checkline_mk_vartype_basic(%s, %s, %s, %s, %s, %s, %s)",
+	    $varname, $type, $op, $value, defined($comment) ? $comment : "<undef>", $list_context, $is_guessed));
+
+	$value_novar = $value;
+	while ($value_novar =~ s/\$\{([^{}]*)\}//g) {
+		my ($varuse) = ($1);
+		if (!$list_context && $varuse =~ m":Q$") {
+			$line->log_warning("The :Q operator should only be used in lists and shell commands.");
+		}
+	}
+
+	my %type_dispatch = (
+		AwkCommand => sub {
+			$opt_debug_unchecked and $line->log_debug("Unchecked AWK command: ${value}");
+		},
+
+		BrokenIn => sub {
+			if ($value ne $value_novar) {
+				$line->log_error("${varname} must not refer to other variables.");
+
+			} elsif ($value =~ m"^pkgsrc-(\d\d\d\d)Q(\d)$") {
+				my ($year, $quarter) = ($1, $2);
+
+				# Fine.
+
+			} else {
+				$line->log_warning("Invalid value \"${value}\" for ${varname}.");
+			}
+			$line->log_note("Please remove this line if the package builds for you.");
+		},
+
+		BuildlinkDepmethod => sub {
+			# Note: this cannot be replaced with { build full } because
+			# enumerations may not contain references to other variables.
+			if ($value ne $value_novar) {
+				# No checks yet.
+			} elsif ($value ne "build" && $value ne "full") {
+				$line->log_warning("Invalid dependency method \"${value}\". Valid methods are \"build\" or \"full\".");
+			}
+		},
+
+		BuildlinkDepth => sub {
+			if (!($op eq "use" && $value eq "+")
+			    && $value ne "\${BUILDLINK_DEPTH}+"
+			    && $value ne "\${BUILDLINK_DEPTH:S/+\$//}") {
+				$line->log_warning("Invalid value for ${varname}.");
+			}
+		},
+
+		BuildlinkPackages => sub {
+			my $re_del = qr"\$\{BUILDLINK_PACKAGES:N(?:[+\-.0-9A-Z_a-z]|\$\{[^\}]+\})+\}";
+			my $re_add = qr"(?:[+\-.0-9A-Z_a-z]|\$\{[^\}]+\})+";
+
+			if (($op eq ":=" && $value =~ m"^${re_del}$") ||
+			    ($op eq ":=" && $value =~ m"^${re_del}\s+${re_add}$") ||
+			    ($op eq "+=" && $value =~ m"^${re_add}$")) {
+				# Fine.
+
+			} else {
+				$line->log_warning("Invalid value for ${varname}.");
+			}
+		},
+
+		Category => sub {
+			my $allowed_categories = join("|", qw(
+				archivers audio
+				benchmarks biology
+				cad chat chinese comms converters cross crosspkgtools
+				databases devel
+				editors emulators
+				filesystems finance fonts
+				games geography gnome gnustep graphics
+				ham
+				inputmethod
+				japanese java
+				kde korean
+				lang linux local
+				mail math mbone meta-pkgs misc multimedia
+				net news
+				packages parallel perl5 pkgtools plan9 print python
+				ruby
+				scm security shells sysutils
+				tcl textproc time tk
+				windowmaker wm www
+				x11 xmms
+			));
+			if ($value !~ m"^(?:${allowed_categories})$") {
+				$line->log_error("Invalid category \"${value}\".");
+			}
+		},
+
+		CFlag => sub {
+			if ($value =~ m"^-D([0-9A-Z_a-z]+)=(.*)") {
+				my ($macname, $macval) = ($1, $2);
+
+				# No checks needed, since the macro definitions
+				# are usually directory names, which don't need
+				# any quoting.
+
+			} elsif ($value =~ m"^-[DU]([0-9A-Z_a-z]+)") {
+				my ($macname) = ($1);
+
+				$opt_debug_unchecked and $line->log_debug("Unchecked macro ${macname} in ${varname}.");
+
+			} elsif ($value =~ m"^-I(.*)") {
+				my ($dirname) = ($1);
+
+				$opt_debug_unchecked and $line->log_debug("Unchecked directory ${dirname} in ${varname}.");
+
+			} elsif ($value eq "-c99") {
+				# Only works on IRIX, but is usually enclosed with
+				# the proper preprocessor conditional.
+
+			} elsif ($value =~ m"^-[OWfgm]|^-std=.*") {
+				$opt_debug_unchecked and $line->log_debug("Unchecked compiler flag ${value} in ${varname}.");
+
+			} elsif ($value =~ m"^-.*") {
+				$line->log_warning("Unknown compiler flag \"${value}\".");
+
+			} elsif ($value =~ regex_unresolved) {
+				$opt_debug_unchecked and $line->log_debug("Unchecked CFLAG: ${value}");
+
+			} else {
+				$line->log_warning("Compiler flag \"${value}\" does not start with a dash.");
+			}
+		},
+
+		Comment => sub {
+			if ($value eq "SHORT_DESCRIPTION_OF_THE_PACKAGE") {
+				$line->log_error("COMMENT must be set.");
+			}
+			if ($value =~ m"^(a|an)\s+"i) {
+				$line->log_warning("COMMENT should not begin with '$1'.");
+			}
+			if ($value =~ m"^[a-z]") {
+				$line->log_warning("COMMENT should start with a capital letter.");
+			}
+			if ($value =~ m"\.$") {
+				$line->log_warning("COMMENT should not end with a period.");
+			}
+			if (length($value) > 70) {
+				$line->log_warning("COMMENT should not be longer than 70 characters.");
+			}
+		},
+
+		Dependency => sub {
+			if ($value =~ m"^(${regex_pkgbase})(<|=|>|<=|>=|!=|-)(${regex_pkgversion})$") {
+				my ($depbase, $depop, $depversion) = ($1, $2, $3);
+
+			} elsif ($value =~ m"^(${regex_pkgbase})-(?:\[(.*)\]\*|(\d+(?:\.\d+)*(?:\.\*)?)(\{,nb\*\}|\*|)|(.*))?$") {
+				my ($depbase, $bracket, $version, $version_wildcard, $other) = ($1, $2, $3, $4, $5);
+
+				if (defined($bracket)) {
+					if ($bracket ne "0-9") {
+						$line->log_warning("Only [0-9]* is allowed in the numeric part of a dependency.");
+					}
+
+				} elsif (defined($version) && defined($version_wildcard) && $version_wildcard ne "") {
+					# Great.
+
+				} elsif (defined($version)) {
+					$line->log_warning("Please append {,nb*} to the version number of this dependency.");
+					$line->explain_warning(
+"Usually, a dependency should stay valid when the PKGREVISION is",
+"increased, since those changes are most often editorial. In the",
+"current form, the dependency only matches if the PKGREVISION is",
+"undefined.");
+
+				} elsif ($other eq "*") {
+					$line->log_warning("Please use ${depbase}-[0-9]* instead of ${depbase}-*.");
+					$line->explain_warning(
+"If you use a * alone, the package specification may match other",
+"packages that have the same prefix, but a longer name. For example,",
+"foo-* matches foo-1.2, but also foo-client-1.2 and foo-server-1.2.");
+
+				} else {
+					$line->log_error("Unknown dependency pattern \"${value}\".");
+				}
+
+			} elsif ($value =~ m"\{") {
+				# Dependency patterns containing alternatives
+				# are just too hard to check.
+				$opt_debug_unchecked and $line->log_debug("Unchecked dependency pattern: ${value}");
+
+			} elsif ($value ne $value_novar) {
+				$opt_debug_unchecked and $line->log_debug("Unchecked dependency: ${value}");
+
+			} else {
+				$line->log_warning("Unknown dependency format: ${value}");
+				$line->explain_warning(
+"Typical dependencies have the form \"package>=2.5\", \"package-[0-9]*\"",
+"or \"package-3.141\".");
+			}
+		},
+
+		DependencyWithPath => sub {
+			if ($value =~ regex_unresolved) {
+				# don't even try to check anything
+			} elsif ($value =~ m"(.*):(\.\./\.\./([^/]+)/([^/]+))$") {
+				my ($pattern, $relpath, $cat, $pkg) = ($1, $2, $3, $4);
+
+				checkline_relative_pkgdir($line, $relpath);
+
+				if ($pkg eq "msgfmt" || $pkg eq "gettext") {
+					$line->log_warning("Please use USE_TOOLS+=msgfmt instead of this dependency.");
+
+				} elsif ($pkg =~ m"^perl\d+") {
+					$line->log_warning("Please use USE_TOOLS+=perl:run instead of this dependency.");
+
+				} elsif ($pkg eq "gmake") {
+					$line->log_warning("Please use USE_TOOLS+=gmake instead of this dependency.");
+
+				}
+
+				if ($pattern =~ regex_dependency_lge) {
+#				($abi_pkg, $abi_version) = ($1, $2);
+				} elsif ($pattern =~ regex_dependency_wildcard) {
+#				($abi_pkg) = ($1);
+				} else {
+					$line->log_error("Unknown dependency pattern \"${pattern}\".");
+				}
+
+			} elsif ($value =~ m":\.\./[^/]+$") {
+				$line->log_warning("Dependencies should have the form \"../../category/package\".");
+				$line->explain_warning(expl_relative_dirs);
+
+			} else {
+				$line->log_warning("Unknown dependency format.");
+				$line->explain_warning(
+"Examples for valid dependencies are:",
+"  package-[0-9]*:../../category/package",
+"  package>=3.41:../../category/package",
+"  package-2.718:../../category/package");
+			}
+		},
+
+		DistSuffix => sub {
+			if ($value eq ".tar.gz") {
+				$line->log_note("${varname} is \".tar.gz\" by default, so this definition may be redundant.");
+			}
+		},
+
+		EmulPlatform => sub {
+			if ($value =~ m"^(\w+)-(\w+)$") {
+				my ($opsys, $arch) = ($1, $2);
+
+				if ($opsys !~ m"^(?:bsdos|cygwin|darwin|dragonfly|freebsd|haiku|hpux|interix|irix|linux|netbsd|openbsd|osf1|sunos|solaris)$") {
+					$line->log_warning("Unknown operating system: ${opsys}");
+				}
+				# no check for $os_version
+				if ($arch !~ m"^(?:i386|alpha|amd64|arc|arm|arm32|cobalt|convex|dreamcast|hpcmips|hpcsh|hppa|ia64|m68k|m88k|mips|mips64|mipsel|mipseb|mipsn32|ns32k|pc532|pmax|powerpc|rs6000|s390|sparc|sparc64|vax|x86_64)$") {
+					$line->log_warning("Unknown hardware architecture: ${arch}");
+				}
+
+			} else {
+				$line->log_warning("\"${value}\" is not a valid emulation platform.");
+				$line->explain_warning(
+"An emulation platform has the form <OPSYS>-<MACHINE_ARCH>.",
+"OPSYS is the lower-case name of the operating system, and MACHINE_ARCH",
+"is the hardware architecture.",
+"",
+"Examples: linux-i386, irix-mipsel.");
+			}
+		},
+
+		FetchURL => sub {
+			checkline_mk_vartype_basic($line, $varname, "URL", $op, $value, $comment, $list_context, $is_guessed);
+
+			my $sites = get_dist_sites();
+			foreach my $site (keys(%{$sites})) {
+				if (index($value, $site) == 0) {
+					my $subdir = substr($value, length($site));
+					my $is_github = $value =~ m"^https://github\.com/";
+					if ($is_github) {
+						$subdir =~ s|/.*|/|;
+					}
+					$line->log_warning(sprintf("Please use \${%s:=%s} instead of \"%s\".", $sites->{$site}, $subdir, $value));
+					if ($is_github) {
+						$line->log_warning("Run \"".conf_make." help topic=github\" for further tips.");
+					}
+					last;
+				}
+			}
+		},
+
+		Filename => sub {
+			if ($value_novar =~ m"/") {
+				$line->log_warning("A filename should not contain a slash.");
+
+			} elsif ($value_novar !~ m"^[-0-9\@A-Za-z.,_~+%]*$") {
+				$line->log_warning("\"${value}\" is not a valid filename.");
+			}
+		},
+
+		Filemask => sub {
+			if ($value_novar !~ m"^[-0-9A-Za-z._~+%*?]*$") {
+				$line->log_warning("\"${value}\" is not a valid filename mask.");
+			}
+		},
+
+		FileMode => sub {
+			if ($value ne "" && $value_novar eq "") {
+				# Fine.
+			} elsif ($value =~ m"^[0-7]{3,4}") {
+				# Fine.
+			} else {
+				$line->log_warning("Invalid file mode ${value}.");
+			}
+		},
+
+		Identifier => sub {
+			if ($value ne $value_novar) {
+				#$line->log_warning("Identifiers should be given directly.");
+			}
+			if ($value_novar =~ m"^[+\-.0-9A-Z_a-z]+$") {
+				# Fine.
+			} elsif ($value ne "" && $value_novar eq "") {
+				# Don't warn here.
+			} else {
+				$line->log_warning("Invalid identifier \"${value}\".");
+			}
+		},
+
+		Integer => sub {
+			if ($value !~ m"^\d+$") {
+				$line->log_warning("${varname} must be a valid integer.");
+			}
+		},
+
+		LdFlag => sub {
+			if ($value =~ m"^-L(.*)") {
+				my ($dirname) = ($1);
+
+				$opt_debug_unchecked and $line->log_debug("Unchecked directory ${dirname} in ${varname}.");
+
+			} elsif ($value =~ m"^-l(.*)") {
+				my ($libname) = ($1);
+
+				$opt_debug_unchecked and $line->log_debug("Unchecked library name ${libname} in ${varname}.");
+
+			} elsif ($value =~ m"^(?:-static)$") {
+				# Assume that the wrapper framework catches these.
+
+			} elsif ($value =~ m"^(-Wl,(?:-R|-rpath|--rpath))") {
+				my ($rpath_flag) = ($1);
+				$line->log_warning("Please use \${COMPILER_RPATH_FLAG} instead of ${rpath_flag}.");
+
+			} elsif ($value =~ m"^-.*") {
+				$line->log_warning("Unknown linker flag \"${value}\".");
+
+			} elsif ($value =~ regex_unresolved) {
+				$opt_debug_unchecked and $line->log_debug("Unchecked LDFLAG: ${value}");
+
+			} else {
+				$line->log_warning("Linker flag \"${value}\" does not start with a dash.");
+			}
+		},
+
+		License => sub {
+
+			use constant deprecated_licenses => array_to_hash(qw(
+				fee-based-commercial-use
+				no-commercial-use no-profit no-redistribution
+				shareware
+			));
+
+			my $licenses = parse_licenses($value);
+			foreach my $license (@$licenses) {
+				my $license_file = "${cwd_pkgsrcdir}/licenses/${license}";
+				if (defined($pkgctx_vardef) && exists($pkgctx_vardef->{"LICENSE_FILE"})) {
+					my $license_file_line = $pkgctx_vardef->{"LICENSE_FILE"};
+
+					$license_file = "${current_dir}/" . resolve_relative_path($license_file_line->get("value"), false);
+				} else {
+					$ipc_used_licenses{$license} = true;
+				}
+
+				if (!-f $license_file) {
+					$line->log_warning("License file ".normalize_pathname($license_file)." does not exist.");
+				}
+
+				if (exists(deprecated_licenses->{$license})) {
+					$line->log_warning("License ${license} is deprecated.");
+				}
+			}
+		},
+
+		Mail_Address => sub {
+			if ($value =~ m"^([+\-.0-9A-Z_a-z]+)\@([-\w\d.]+)$") {
+				my ($localpart, $domain) = ($1, $2);
+				if ($domain =~ m"^NetBSD.org"i && $domain ne "NetBSD.org") {
+					$line->log_warning("Please write NetBSD.org instead of ${domain}.");
+				}
+				if ("${localpart}\@${domain}" =~ m"^(tech-pkg|packages)\@NetBSD\.org$"i) {
+					$line->log_warning("${localpart}\@${domain} is deprecated. Use pkgsrc-users\@NetBSD.org instead.");
+				}
+
+			} else {
+				$line->log_warning("\"${value}\" is not a valid mail address.");
+			}
+		},
+
+		Message => sub {
+			if ($value =~ m"^[\"'].*[\"']$") {
+				$line->log_warning("${varname} should not be quoted.");
+				$line->explain_warning(
+"The quoting is only needed for variables which are interpreted as",
+"multiple words (or, generally speaking, a list of something). A single",
+"text message does not belong to this class, since it is only printed",
+"as a whole.",
+"",
+"On the other hand, PKG_FAIL_REASON is a _list_ of text messages, so in",
+"that case, the quoting has to be done.");
+			}
+		},
+
+		Option => sub {
+			if ($value ne $value_novar) {
+				$opt_debug_unchecked and $line->log_debug("Unchecked option name \"${value}\".");
+
+			} elsif ($value_novar =~ m"^-?([a-z][-0-9a-z\+]*)$") {
+				my ($optname) = ($1);
+
+				if (!exists(get_pkg_options()->{$optname})) {
+					$line->log_warning("Unknown option \"${value}\".");
+					$line->explain_warning(
+"This option is not documented in the mk/defaults/options.description",
+"file. If this is not a typo, please think of a brief but precise",
+"description and either update that file yourself or ask on the",
+"tech-pkg\@NetBSD.org mailing list.");
+				}
+
+			} elsif ($value_novar =~ m"^-?([a-z][-0-9a-z_\+]*)$") {
+				my ($optname) = ($1);
+
+				$line->log_warning("Use of the underscore character in option names is deprecated.");
+
+			} else {
+				$line->log_error("\"${value}\" is not a valid option name.");
+			}
+		},
+
+		Pathlist => sub {
+
+			if ($value !~ m":" && $is_guessed) {
+				checkline_mk_vartype_basic($line, $varname, "Pathname", $op, $value, $comment, $list_context, $is_guessed);
+
+			} else {
+
+				# XXX: The splitting will fail if $value contains any
+				# variables with modifiers, for example :Q or :S/././.
+				foreach my $p (split(qr":", $value)) {
+					my $p_novar = remove_variables($p);
+
+					if ($p_novar !~ m"^[-0-9A-Za-z._~+%/]*$") {
+						$line->log_warning("\"${p}\" is not a valid pathname.");
+					}
+
+					if ($p !~ m"^[\$/]") {
+						$line->log_warning("All components of ${varname} (in this case \"${p}\") should be an absolute path.");
+					}
+				}
+			}
+		},
+
+		Pathmask => sub {
+			if ($value_novar !~ m"^[#\-0-9A-Za-z._~+%*?/\[\]]*$") {
+				$line->log_warning("\"${value}\" is not a valid pathname mask.");
+			}
+			checkline_mk_absolute_pathname($line, $value);
+		},
+
+		Pathname => sub {
+			if ($value_novar !~ m"^[#\-0-9A-Za-z._~+%/]*$") {
+				$line->log_warning("\"${value}\" is not a valid pathname.");
+			}
+			checkline_mk_absolute_pathname($line, $value);
+		},
+
+		Perl5Packlist => sub {
+			if ($value ne $value_novar) {
+				$line->log_warning("${varname} should not depend on other variables.");
+			}
+		},
+
+		PkgName => sub {
+			if ($value eq $value_novar && $value !~ regex_pkgname) {
+				$line->log_warning("\"${value}\" is not a valid package name. A valid package name has the form packagename-version, where version consists only of digits, letters and dots.");
+			}
+		},
+
+		PkgPath => sub {
+			checkline_relative_pkgdir($line, "$cur_pkgsrcdir/$value");
+		},
+
+		PkgOptionsVar => sub {
+			checkline_mk_vartype_basic($line, $varname, "Varname", $op, $value, $comment, false, $is_guessed);
+			if ($value =~ m"\$\{PKGBASE[:\}]") {
+				$line->log_error("PKGBASE must not be used in PKG_OPTIONS_VAR.");
+				$line->explain_error(
+"PKGBASE is defined in bsd.pkg.mk, which is included as the",
+"very last file, but PKG_OPTIONS_VAR is evaluated earlier.",
+"Use \${PKGNAME:C/-[0-9].*//} instead.");
+			}
+		},
+
+		PkgRevision => sub {
+			if ($value !~ m"^[1-9]\d*$") {
+				$line->log_warning("${varname} must be a positive integer number.");
+			}
+			if ($line->fname !~ m"(?:^|/)Makefile$") {
+				$line->log_error("${varname} only makes sense directly in the package Makefile.");
+				$line->explain_error(
+"Usually, different packages using the same Makefile.common have",
+"different dependencies and will be bumped at different times (e.g. for",
+"shlib major bumps) and thus the PKGREVISIONs must be in the separate",
+"Makefiles. There is no practical way of having this information in a",
+"commonly used Makefile.");
+			}
+		},
+
+		PlatformTriple => sub {
+			my $part = qr"(?:\[[^\]]+\]|[^-\[])+";
+			if ($value =~ m"^(${part})-(${part})-(${part})$") {
+				my ($opsys, $os_version, $arch) = ($1, $2, $3);
+
+				if ($opsys !~ m"^(?:\*|BSDOS|Cygwin|Darwin|DragonFly|FreeBSD|Haiku|HPUX|Interix|IRIX|Linux|NetBSD|OpenBSD|OSF1|QNX|SunOS)$") {
+					$line->log_warning("Unknown operating system: ${opsys}");
+				}
+				# no check for $os_version
+				if ($arch !~ m"^(?:\*|i386|alpha|amd64|arc|arm|arm32|cobalt|convex|dreamcast|hpcmips|hpcsh|hppa|ia64|m68k|m88k|mips|mips64|mipsel|mipseb|mipsn32|ns32k|pc532|pmax|powerpc|rs6000|s390|sparc|sparc64|vax|x86_64)$") {
+					$line->log_warning("Unknown hardware architecture: ${arch}");
+				}
+
+			} else {
+				$line->log_warning("\"${value}\" is not a valid platform triple.");
+				$line->explain_warning(
+"A platform triple has the form <OPSYS>-<OS_VERSION>-<MACHINE_ARCH>.",
+"Each of these components may be a shell globbing expression.",
+"Examples: NetBSD-*-i386, *-*-*, Linux-*-*.");
+			}
+		},
+
+		PrefixPathname => sub {
+			if ($value =~ m"^man/(.*)") {
+				my ($mansubdir) = ($1);
+
+				$line->log_warning("Please use \"\${PKGMANDIR}/${mansubdir}\" instead of \"${value}\".");
+			}
+		},
+
+		PythonDependency => sub {
+			if ($value ne $value_novar) {
+				$line->log_warning("Python dependencies should not contain variables.");
+			}
+			if ($value_novar !~ m"^[+\-.0-9A-Z_a-z]+(?:|:link|:build)$") {
+				$line->log_warning("Invalid Python dependency \"${value}\".");
+				$line->explain_warning(
+"Python dependencies must be an identifier for a package, as specified",
+"in lang/python/versioned_dependencies.mk. This identifier may be",
+"followed by :build for a build-time only dependency, or by :link for",
+"a run-time only dependency.");
+			}
+		},
+
+		RelativePkgDir => sub {
+			checkline_relative_pkgdir($line, $value);
+		},
+
+		RelativePkgPath => sub {
+			checkline_relative_path($line, $value, true);
+		},
+
+		Restricted => sub {
+			if ($value ne "\${RESTRICTED}") {
+				$line->log_warning("The only valid value for ${varname} is \${RESTRICTED}.");
+				$line->explain_warning(
+"These variables are used to control which files may be mirrored on FTP",
+"servers or CD-ROM collections. They are not intended to mark packages",
+"whose only MASTER_SITES are on ftp.NetBSD.org.");
+			}
+		},
+
+		SedCommand => sub {
+		},
+
+		SedCommands => sub {
+			my $words = shell_split($value);
+			if (!$words) {
+				$line->log_error("Invalid shell words in sed commands.");
+				$line->explain_error(
+"If your sed commands have embedded \"#\" characters, you need to escape",
+"them with a backslash, otherwise make(1) will interpret them as a",
+"comment, no matter if they occur in single or double quotes or",
+"whatever.");
+
+			} else {
+				my $nwords = scalar(@{$words});
+				my $ncommands = 0;
+
+				for (my $i = 0; $i < $nwords; $i++) {
+					my $word = $words->[$i];
+					checkline_mk_shellword($line, $word, true);
+
+					if ($word eq "-e") {
+						if ($i + 1 < $nwords) {
+							# Check the real sed command here.
+							$i++;
+							$ncommands++;
+							if ($ncommands > 1) {
+								$line->log_warning("Each sed command should appear in an assignment of its own.");
+								$line->explain_warning(
+"For example, instead of",
+"    SUBST_SED.foo+=        -e s,command1,, -e s,command2,,",
+"use",
+"    SUBST_SED.foo+=        -e s,command1,,",
+"    SUBST_SED.foo+=        -e s,command2,,",
+"",
+"This way, short sed commands cannot be hidden at the end of a line.");
+							}
+							checkline_mk_shellword($line, $words->[$i - 1], true);
+							checkline_mk_shellword($line, $words->[$i], true);
+							checkline_mk_vartype_basic($line, $varname, "SedCommand", $op, $words->[$i], $comment, $list_context, $is_guessed);
+						} else {
+							$line->log_error("The -e option to sed requires an argument.");
+						}
+					} elsif ($word eq "-E") {
+						# Switch to extended regular expressions mode.
+
+					} elsif ($word eq "-n") {
+						# Don't print lines per default.
+
+					} elsif ($i == 0 && $word =~ m"^([\"']?)(?:\d*|/.*/)s(.).*\2g?\1$") {
+						$line->log_warning("Please always use \"-e\" in sed commands, even if there is only one substitution.");
+
+					} else {
+						$line->log_warning("Unknown sed command ${word}.");
+					}
+				}
+			}
+		},
+
+		ShellCommand => sub {
+			checkline_mk_shelltext($line, $value);
+		},
+
+		ShellWord => sub {
+			if (!$list_context) {
+				checkline_mk_shellword($line, $value, true);
+			}
+		},
+
+		Stage => sub {
+			if ($value !~ m"^(?:pre|do|post)-(?:extract|patch|configure|build|install)$") {
+				$line->log_warning("Invalid stage name. Use one of {pre,do,post}-{extract,patch,configure,build,install}.");
+			}
+		},
+
+		String => sub {
+			# No further checks possible.
+		},
+
+		Tool => sub {
+			if ($varname eq "TOOLS_NOOP" && $op eq "+=") {
+				# no warning for package-defined tool definitions
+
+			} elsif ($value =~ m"^([-\w]+|\[)(?::(\w+))?$") {
+				my ($toolname, $tooldep) = ($1, $2);
+				if (!exists(get_tool_names()->{$toolname})) {
+					$line->log_error("Unknown tool \"${toolname}\".");
+				}
+				if (defined($tooldep) && $tooldep !~ m"^(?:bootstrap|build|pkgsrc|run)$") {
+					$line->log_error("Unknown tool dependency \"${tooldep}\". Use one of \"build\", \"pkgsrc\" or \"run\".");
+				}
+			} else {
+				$line->log_error("Invalid tool syntax: \"${value}\".");
+			}
+		},
+
+		Unchecked => sub {
+			# Do nothing, as the name says.
+		},
+
+		URL => sub {
+			if ($value eq "" && defined($comment) && $comment =~ m"^#") {
+				# Ok
+
+			} elsif ($value =~ m"\$\{(MASTER_SITE_[^:]*).*:=(.*)\}$") {
+				my ($name, $subdir) = ($1, $2);
+
+				if (!exists(get_dist_sites_names()->{$name})) {
+					$line->log_error("${name} does not exist.");
+				}
+				if ($subdir !~ m"/$") {
+					$line->log_error("The subdirectory in ${name} must end with a slash.");
+				}
+
+			} elsif ($value =~ regex_unresolved) {
+				# No further checks
+
+			} elsif ($value =~ m"^(https?|ftp|gopher)://([-0-9A-Za-z.]+)(?::(\d+))?/([-%&+,./0-9:=?\@A-Z_a-z~]|#)*$") {
+				my ($proto, $host, $port, $path) = ($1, $2, $3, $4);
+
+				if ($host =~ m"\.NetBSD\.org$"i && $host !~ m"\.NetBSD\.org$") {
+					$line->log_warning("Please write NetBSD.org instead of ${host}.");
+				}
+
+			} elsif ($value =~ m"^([0-9A-Za-z]+)://([^/]+)(.*)$") {
+				my ($scheme, $host, $abs_path) = ($1, $2, $3);
+
+				if ($scheme ne "ftp" && $scheme ne "http" && $scheme ne "https" && $scheme ne "gopher") {
+					$line->log_warning("\"${value}\" is not a valid URL. Only ftp, gopher, http, and https URLs are allowed here.");
+
+				} elsif ($abs_path eq "") {
+					$line->log_note("For consistency, please add a trailing slash to \"${value}\".");
+
+				} else {
+					$line->log_warning("\"${value}\" is not a valid URL.");
+				}
+
+			} else {
+				$line->log_warning("\"${value}\" is not a valid URL.");
+			}
+		},
+
+		UserGroupName => sub {
+			if ($value ne $value_novar) {
+				# No checks for now.
+			} elsif ($value !~ m"^[0-9_a-z]+$") {
+				$line->log_warning("Invalid user or group name \"${value}\".");
+			}
+		},
+
+		Varname => sub {
+			if ($value ne "" && $value_novar eq "") {
+				# The value of another variable
+
+			} elsif ($value_novar !~ m"^[A-Z_][0-9A-Z_]*(?:[.].*)?$") {
+				$line->log_warning("\"${value}\" is not a valid variable name.");
+			}
+		},
+
+		Version => sub {
+			if ($value !~ m"^([\d.])+$") {
+				$line->log_warning("Invalid version number \"${value}\".");
+			}
+		},
+
+		WrapperReorder => sub {
+			if ($value =~ m"^reorder:l:([\w\-]+):([\w\-]+)$") {
+				my ($lib1, $lib2) = ($1, $2);
+				# Fine.
+			} else {
+				$line->log_warning("Unknown wrapper reorder command \"${value}\".");
+			}
+		},
+
+		WrapperTransform => sub {
+			if ($value =~ m"^rm:(?:-[DILOUWflm].*|-std=.*)$") {
+				# Fine.
+
+			} elsif ($value =~ m"^l:([^:]+):(.+)$") {
+				my ($lib, $replacement_libs) = ($1, $2);
+				# Fine.
+
+			} elsif ($value =~ m"^'?(?:opt|rename|rm-optarg|rmdir):.*$") {
+				# FIXME: This is cheated.
+				# Fine.
+
+			} elsif ($value eq "-e" || $value =~ m"^\"?'?s[|:,]") {
+				# FIXME: This is cheated.
+				# Fine.
+
+			} else {
+				$line->log_warning("Unknown wrapper transform command \"${value}\".");
+			}
+		},
+
+		WrkdirSubdirectory => sub {
+			checkline_mk_vartype_basic($line, $varname, "Pathname", $op, $value, $comment, $list_context, $is_guessed);
+			if ($value eq "\${WRKDIR}") {
+				# Fine.
+			} else {
+				$opt_debug_unchecked and $line->log_debug("Unchecked subdirectory \"${value}\" of \${WRKDIR}.");
+			}
+		},
+
+		WrksrcSubdirectory => sub {
+			if ($value =~ m"^(\$\{WRKSRC\})(?:/(.*))?") {
+				my ($prefix, $rest) = ($1, $2);
+				$line->log_note("You can use \"" . (defined($rest) ? $rest : ".") . "\" instead of \"${value}\".");
+
+			} elsif ($value ne "" && $value_novar eq "") {
+				# The value of another variable
+
+			} elsif ($value_novar !~ m"^(?:\.|[0-9A-Za-z_\@][-0-9A-Za-z_\@./+]*)$") {
+				$line->log_warning("\"${value}\" is not a valid subdirectory of \${WRKSRC}.");
+			}
+		},
+
+		Yes => sub {
+			if ($value !~ m"^(?:YES|yes)(?:\s+#.*)?$") {
+				$line->log_warning("${varname} should be set to YES or yes.");
+				$line->explain_warning(
+"This variable means \"yes\" if it is defined, and \"no\" if it is",
+"undefined. Even when it has the value \"no\", this means \"yes\".",
+"Therefore when it is defined, its value should correspond to its",
+"meaning.");
+			}
+		},
+
+		YesNo => sub {
+			if ($value !~ m"^(?:YES|yes|NO|no)(?:\s+#.*)?$") {
+				$line->log_warning("${varname} should be set to YES, yes, NO, or no.");
+			}
+		},
+
+		YesNo_Indirectly => sub {
+			if ($value_novar ne "" && $value !~ m"^(?:YES|yes|NO|no)(?:\s+#.*)?$") {
+				$line->log_warning("${varname} should be set to YES, yes, NO, or no.");
+			}
+		},
+	);
+
+	if (ref($type) eq "HASH") {
+		if (!exists($type->{$value})) {
+			$line->log_warning("\"${value}\" is not valid for ${varname}. Use one of { ".join(" ", sort(keys(%{$type})))." } instead.");
+		}
+
+	} elsif (defined $type_dispatch{$type}) {
+		$type_dispatch{$type}->();
+
+	} else {
+		$line->log_fatal("Type ${type} unknown.");
+	}
+}
+
+# Checks whether the list of version numbers that are given as the
+# C<value> of the variable C<varname> are in decreasing order.
+sub checkline_decreasing_order($$$) {
+	my ($line, $varname, $value) = @_;
+
+	my @pyver = split(qr"\s+", $value);
+	if (!@pyver) {
+		$line->log_error("There must be at least one value for ${varname}.");
+		return;
+	}
+
+	my $ver = shift(@pyver);
+	if ($ver !~ m"^\d+$") {
+		$line->log_error("All values for ${varname} must be numeric.");
+		return;
+	}
+
+	while (@pyver) {
+		my $nextver = shift(@pyver);
+		if ($nextver !~ m"^\d+$") {
+			$line->log_error("All values for ${varname} must be numeric.");
+			return;
+		}
+
+		if ($nextver >= $ver) {
+			$line->log_warning("The values for ${varname} should be in decreasing order.");
+			$line->explain_warning(
+"If they aren't, it may be possible that needless versions of packages",
+"are installed.");
+		}
+		$ver = $nextver;
+	}
+}
+
+sub checkline_mk_vartype($$$$$) {
+	my ($line, $varname, $op, $value, $comment) = @_;
+
+	return unless $opt_warn_types;
+
+	my $vartypes = get_vartypes_map();
+	my $varbase = varname_base($varname);
+	my $varcanon = varname_canon($varname);
+
+	my $type = get_variable_type($line, $varname);
+
+	if ($op eq "+=") {
+		if (defined($type)) {
+			if (!$type->may_use_plus_eq()) {
+				$line->log_warning("The \"+=\" operator should only be used with lists.");
+			}
+		} elsif ($varbase !~ m"^_" && $varbase !~ get_regex_plurals()) {
+			$line->log_warning("As ${varname} is modified using \"+=\", its name should indicate plural.");
+		}
+	}
+
+	if (!defined($type)) {
+		# Cannot check anything if the type is not known.
+		$opt_debug_unchecked and $line->log_debug("Unchecked variable assignment for ${varname}.");
+
+	} elsif ($op eq "!=") {
+		$opt_debug_misc and $line->log_debug("Use of !=: ${value}");
+
+	} elsif ($type->kind_of_list != LK_NONE) {
+		my (@words, $rest);
+
+		if ($type->kind_of_list == LK_INTERNAL) {
+			@words = split(qr"\s+", $value);
+			$rest = "";
+		} else {
+			@words = ();
+			$rest = $value;
+			while ($rest =~ s/^$regex_shellword//) {
+				my ($word) = ($1);
+				last if ($word =~ m"^#");
+				push(@words, $1);
+			}
+		}
+
+		foreach my $word (@words) {
+			checkline_mk_vartype_basic($line, $varname, $type->basic_type, $op, $word, $comment, true, $type->is_guessed);
+			if ($type->kind_of_list != LK_INTERNAL) {
+				checkline_mk_shellword($line, $word, true);
+			}
+		}
+
+		if ($rest !~ m"^\s*$") {
+			$line->log_error("Internal pkglint error: rest=${rest}");
+		}
+
+	} else {
+		checkline_mk_vartype_basic($line, $varname, $type->basic_type, $op, $value, $comment, $type->is_practically_a_list(), $type->is_guessed);
+	}
+}
+
+sub checkline_mk_varassign($$$$$) {
+	my ($line, $varname, $op, $value, $comment) = @_;
+	my ($used_vars);
+	my $varbase = varname_base($varname);
+	my $varcanon = varname_canon($varname);
+
+	$opt_debug_trace and $line->log_debug("checkline_mk_varassign($varname, $op, $value)");
+
+	checkline_mk_vardef($line, $varname, $op);
+
+	if ($op eq "?=" && defined($seen_bsd_prefs_mk) && !$seen_bsd_prefs_mk) {
+		if ($varbase eq "BUILDLINK_PKGSRCDIR"
+		    || $varbase eq "BUILDLINK_DEPMETHOD"
+		    || $varbase eq "BUILDLINK_ABI_DEPENDS") {
+			# FIXME: What about these ones? They occur quite often.
+		} else {
+			$opt_warn_extra and $line->log_warning("Please include \"../../mk/bsd.prefs.mk\" before using \"?=\".");
+			$opt_warn_extra and $line->explain_warning(
+"The ?= operator is used to provide a default value to a variable. In",
+"pkgsrc, many variables can be set by the pkgsrc user in the mk.conf",
+"file. This file must be included explicitly. If a ?= operator appears",
+"before mk.conf has been included, it will not care about the user's",
+"preferences, which can result in unexpected behavior. The easiest way",
+"to include the mk.conf file is by including the bsd.prefs.mk file,",
+"which will take care of everything.");
+		}
+	}
+
+	checkline_mk_text($line, $value);
+	checkline_mk_vartype($line, $varname, $op, $value, $comment);
+
+	# If the variable is not used and is untyped, it may be a
+	# spelling mistake.
+	if ($op eq ":=" && $varname eq lc($varname)) {
+		$opt_debug_unchecked and $line->log_debug("${varname} might be unused unless it is an argument to a procedure file.");
+		# TODO: check $varname against the list of "procedure files".
+
+	} elsif (!var_is_used($varname)) {
+		my $vartypes = get_vartypes_map();
+		my $deprecated = get_deprecated_map();
+
+		if (exists($vartypes->{$varname}) || exists($vartypes->{$varcanon})) {
+			# Ok
+		} elsif (exists($deprecated->{$varname}) || exists($deprecated->{$varcanon})) {
+			# Ok
+		} else {
+			$line->log_warning("${varname} is defined but not used. Spelling mistake?");
+		}
+	}
+
+	if ($value =~ m"/etc/rc\.d") {
+		$line->log_warning("Please use the RCD_SCRIPTS mechanism to install rc.d scripts automatically to \${RCD_SCRIPTS_EXAMPLEDIR}.");
+	}
+
+	if (!$is_internal && $varname =~ m"^_") {
+		$line->log_warning("Variable names starting with an underscore are reserved for internal pkgsrc use.");
+	}
+
+	if ($varname eq "PERL5_PACKLIST" && defined($effective_pkgbase) && $effective_pkgbase =~ m"^p5-(.*)") {
+		my ($guess) = ($1);
+		$guess =~ s/-/\//g;
+		$guess = "auto/${guess}/.packlist";
+
+		my ($ucvalue, $ucguess) = (uc($value), uc($guess));
+		if ($ucvalue ne $ucguess && $ucvalue ne "\${PERL5_SITEARCH\}/${ucguess}") {
+			$line->log_warning("Unusual value for PERL5_PACKLIST -- \"${guess}\" expected.");
+		}
+	}
+
+	if ($varname eq "CONFIGURE_ARGS" && $value =~ m"=\$\{PREFIX\}/share/kde") {
+		$line->log_note("Please .include \"../../meta-pkgs/kde3/kde3.mk\" instead of this line.");
+		$line->explain_note(
+"That file probably does many things automatically and consistently that",
+"this package also does. When using kde3.mk, you can probably also leave",
+"out some explicit dependencies.");
+	}
+
+	if ($varname eq "EVAL_PREFIX" && $value =~ m"^([\w_]+)=") {
+		my ($eval_varname) = ($1);
+
+		# The variables mentioned in EVAL_PREFIX will later be
+		# defined by find-prefix.mk. Therefore, they are marked
+		# as known in the current file.
+		$mkctx_vardef->{$eval_varname} = $line;
+	}
+
+	if ($varname eq "PYTHON_VERSIONS_ACCEPTED") {
+		checkline_decreasing_order($line, $varname, $value);
+	}
+
+	if (defined($comment) && $comment eq "# defined" && $varname !~ m".*(?:_MK|_COMMON)$") {
+		$line->log_note("Please use \"# empty\", \"# none\" or \"yes\" instead of \"# defined\".");
+		$line->explain_note(
+"The value #defined says something about the state of the variable, but",
+"not what that _means_. In some cases a variable that is defined means",
+"\"yes\", in other cases it is an empty list (which is also only the",
+"state of the variable), whose meaning could be described with \"none\".",
+"It is this meaning that should be described.");
+	}
+
+	if ($value =~ m"\$\{(PKGNAME|PKGVERSION)[:\}]") {
+		my ($pkgvarname) = ($1);
+		if ($varname =~ m"^PKG_.*_REASON$") {
+			# ok
+		} elsif ($varname =~ m"^(?:DIST_SUBDIR|WRKSRC)$") {
+			$line->log_warning("${pkgvarname} should not be used in ${varname}, as it sometimes includes the PKGREVISION. Please use ${pkgvarname}_NOREV instead.");
+		} else {
+			$opt_debug_misc and $line->log_debug("Use of PKGNAME in ${varname}.");
+		}
+	}
+
+	if (exists(get_deprecated_map()->{$varname})) {
+		$line->log_warning("Definition of ${varname} is deprecated. ".get_deprecated_map()->{$varname});
+	} elsif (exists(get_deprecated_map()->{$varcanon})) {
+		$line->log_warning("Definition of ${varname} is deprecated. ".get_deprecated_map()->{$varcanon});
+	}
+
+	if ($varname =~ m"^SITES_") {
+		$line->log_warning("SITES_* is deprecated. Please use SITES.* instead.");
+	}
+
+	if ($value =~ m"^[^=]\@comment") {
+		$line->log_warning("Please don't use \@comment in ${varname}.");
+		$line->explain_warning(
+"Here you are defining a variable containing \@comment. As this value",
+"typically includes a space as the last character you probably also used",
+"quotes around the variable. This can lead to confusion when adding this",
+"variable to PLIST_SUBST, as all other variables are quoted using the :Q",
+"operator when they are appended. As it is hard to check whether a",
+"variable that is appended to PLIST_SUBST is already quoted or not, you",
+"should not have pre-quoted variables at all. To solve this, you should",
+"directly use PLIST_SUBST+= ${varname}=${value} or use any other",
+"variable for collecting the list of PLIST substitutions and later",
+"append that variable with PLIST_SUBST+= \${MY_PLIST_SUBST}.");
+	}
+
+	# Mark the variable as PLIST condition. This is later used in
+	# checkfile_PLIST.
+	if (defined($pkgctx_plist_subst_cond) && $value =~ m"(.+)=.*\@comment.*") {
+		$pkgctx_plist_subst_cond->{$1}++;
+	}
+
+	use constant op_to_use_time => {
+		":="	=> VUC_TIME_LOAD,
+		"!="	=> VUC_TIME_LOAD,
+		"="	=> VUC_TIME_RUN,
+		"+="	=> VUC_TIME_RUN,
+		"?="	=> VUC_TIME_RUN
+	};
+	
+	$used_vars = extract_used_variables($line, $value);
+	my $vuc = PkgLint::VarUseContext->new(
+		op_to_use_time->{$op},
+		get_variable_type($line, $varname),
+		VUC_SHELLWORD_UNKNOWN,		# XXX: maybe PLAIN?
+		VUC_EXTENT_UNKNOWN
+	);
+	foreach my $used_var (@{$used_vars}) {
+		checkline_mk_varuse($line, $used_var, "", $vuc);
+	}
+}
+
+# The bmake parser is way too sloppy about syntax, so we need to check
+# that here.
+#
+sub checkline_mk_cond($$) {
+	my ($line, $cond) = @_;
+	my ($op, $varname, $match, $value);
+
+	$opt_debug_trace and $line->log_debug("checkline_mk_cond($cond)");
+	my $tree = parse_mk_cond($line, $cond);
+	if (tree_match($tree, ["not", ["empty", ["match", \$varname, \$match]]])) {
+		#$line->log_note("tree_match: varname=$varname, match=$match");
+
+		my $type = get_variable_type($line, $varname);
+		my $btype = defined($type) ? $type->basic_type : undef;
+		if (defined($btype) && ref($type->basic_type) eq "HASH") {
+			if ($match !~ m"[\$\[*]" && !exists($btype->{$match})) {
+				$line->log_warning("Invalid :M value \"$match\". Only { " . join(" ", sort keys %$btype) . " } are allowed.");
+			}
+		}
+
+		# Currently disabled because the valid options can also be defined in PKG_OPTIONS_GROUP.*.
+		# Additionally, all these variables may have multiple assigments (+=).
+		if (false && $varname eq "PKG_OPTIONS" && defined($pkgctx_vardef) && exists($pkgctx_vardef->{"PKG_SUPPORTED_OPTIONS"})) {
+			my $options = $pkgctx_vardef->{"PKG_SUPPORTED_OPTIONS"}->get("value");
+
+			if ($match !~ m"[\$\[*]" && index(" $options ", " $match ") == -1) {
+				$line->log_warning("Invalid option \"$match\". Only { $options } are allowed.");
+			}
+		}
+
+		# TODO: PKG_BUILD_OPTIONS. That requires loading the
+		# complete package definitition for the package "pkgbase"
+		# or some other database. If we could confine all option
+		# definitions to options.mk, this would become easier.
+
+	} elsif (tree_match($tree, [\$op, ["var", \$varname], ["string", \$value]])) {
+		checkline_mk_vartype($line, $varname, "use", $value, undef);
+
+	}
+	# XXX: When adding new cases, be careful that the variables may have
+	# been partially initialized by previous calls to tree_match.
+	# XXX: Maybe it is better to clear these references at the beginning
+	# of tree_match.
+}
+
+#
+# Procedures to check an array of lines.
+#
+
+sub checklines_trailing_empty_lines($) {
+	my ($lines) = @_;
+	my ($last, $max);
+
+	$max = $#{$lines} + 1;
+	for ($last = $max; $last > 1 && $lines->[$last - 1]->text eq ""; ) {
+		$last--;
+	}
+	if ($last != $max) {
+		$lines->[$last]->log_note("Trailing empty lines.");
+	}
+}
+
+sub checklines_package_Makefile_varorder($) {
+	my ($lines) = @_;
+
+	return unless $opt_warn_varorder;
+
+	use enum qw(once optional many);
+	my (@sections) = (
+		[ "Initial comments", once,
+			[
+			]
+		],
+		[ "Unsorted stuff, part 1", once,
+			[
+				[ "DISTNAME", optional ],
+				[ "PKGNAME",  optional ],
+				[ "PKGREVISION", optional ],
+				[ "CATEGORIES", once ],
+				[ "MASTER_SITES", optional ],
+				[ "DIST_SUBDIR", optional ],
+				[ "EXTRACT_SUFX", optional ],
+				[ "DISTFILES", many ],
+				[ "SITES.*", many ],
+			]
+		],
+		[ "Distribution patches", optional,
+			[
+				[ "PATCH_SITES", optional ], # or once?
+				[ "PATCH_SITE_SUBDIR", optional ],
+				[ "PATCHFILES", optional ], # or once?
+				[ "PATCH_DIST_ARGS", optional ],
+				[ "PATCH_DIST_STRIP", optional ],
+				[ "PATCH_DIST_CAT", optional ],
+			]
+		],
+		[ "Unsorted stuff, part 2", once,
+			[
+				[ "MAINTAINER", optional ],
+				[ "OWNER", optional ],
+				[ "HOMEPAGE", optional ],
+				[ "COMMENT", once ],
+				[ "LICENSE", once ],
+			]
+		],
+		[ "Legal issues", optional,
+			[
+				[ "LICENSE_FILE", optional ],
+				[ "RESTRICTED", optional ],
+				[ "NO_BIN_ON_CDROM", optional ],
+				[ "NO_BIN_ON_FTP", optional ],
+				[ "NO_SRC_ON_CDROM", optional ],
+				[ "NO_SRC_ON_FTP", optional ],
+			]
+		],
+		[ "Technical restrictions", optional,
+			[
+				[ "BROKEN_EXCEPT_ON_PLATFORM", many ],
+				[ "BROKEN_ON_PLATFORM", many ],
+				[ "NOT_FOR_PLATFORM", many ],
+				[ "ONLY_FOR_PLATFORM", many ],
+				[ "NOT_FOR_COMPILER", many ],
+				[ "ONLY_FOR_COMPILER", many ],
+				[ "NOT_FOR_UNPRIVILEGED", optional ],
+				[ "ONLY_FOR_UNPRIVILEGED", optional ],
+			]
+		],
+		[ "Dependencies", optional,
+			[
+				[ "BUILD_DEPENDS", many ],
+				[ "TOOL_DEPENDS", many ],
+				[ "DEPENDS", many ],
+			]
+		]
+	);
+
+	if (!defined($seen_Makefile_common) || $seen_Makefile_common) {
+		return;
+	}
+
+	my ($lineno, $sectindex, $varindex) = (0, -1, 0);
+	my ($next_section, $vars, $below, $below_what) = (true, undef, {}, undef);
+
+	# If the current section is optional but contains non-optional
+	# fields, the complete section may be skipped as long as there
+	# has not been a non-optional variable.
+	my $may_skip_section = false;
+
+	# In each iteration, one of the following becomes true:
+	# - new.lineno > old.lineno
+	# - new.sectindex > old.sectindex
+	# - new.sectindex == old.sectindex && new.varindex > old.varindex
+	# - new.next_section == true && old.next_section == false
+	while ($lineno <= $#{$lines}) {
+		my $line = $lines->[$lineno];
+		my $text = $line->text;
+
+		$opt_debug_misc and $line->log_debug("[varorder] section ${sectindex} variable ${varindex}.");
+
+		if ($next_section) {
+			$next_section = false;
+			$sectindex++;
+			last if ($sectindex > $#sections);
+			$vars = $sections[$sectindex]->[2];
+			$may_skip_section = ($sections[$sectindex]->[1] == optional);
+			$varindex = 0;
+		}
+
+		if ($text =~ m"^#") {
+			$lineno++;
+
+		} elsif ($line->has("varcanon")) {
+			my $varcanon = $line->get("varcanon");
+
+			if (exists($below->{$varcanon})) {
+				if (defined($below->{$varcanon})) {
+					$line->log_warning("${varcanon} appears too late. Please put it below $below->{$varcanon}.");
+				} else {
+					$line->log_warning("${varcanon} appears too late. It should be the very first definition.");
+				}
+				$lineno++;
+				next;
+			}
+
+			while ($varindex <= $#{$vars} && $varcanon ne $vars->[$varindex]->[0] && ($vars->[$varindex]->[1] != once || $may_skip_section)) {
+				if ($vars->[$varindex]->[1] == once) {
+					$may_skip_section = false;
+				}
+				$below->{$vars->[$varindex]->[0]} = $below_what;
+				$varindex++;
+			}
+			if ($varindex > $#{$vars}) {
+				if ($sections[$sectindex]->[1] != optional) {
+					$line->log_warning("Empty line expected.");
+				}
+				$next_section = true;
+
+			} elsif ($varcanon ne $vars->[$varindex]->[0]) {
+				$line->log_warning("Expected " . $vars->[$varindex]->[0] . ", but found " . $varcanon . ".");
+				$lineno++;
+
+			} else {
+				if ($vars->[$varindex]->[1] != many) {
+					$below->{$vars->[$varindex]->[0]} = $below_what;
+					$varindex++;
+				}
+				$lineno++;
+			}
+			$below_what = $varcanon;
+
+		} else {
+			while ($varindex <= $#{$vars}) {
+				if ($vars->[$varindex]->[1] == once && !$may_skip_section) {
+					$line->log_warning($vars->[$varindex]->[0] . " should be set here.");
+				}
+				$below->{$vars->[$varindex]->[0]} = $below_what;
+				$varindex++;
+			}
+			$next_section = true;
+			if ($text eq "") {
+				$below_what = "the previous empty line";
+				$lineno++;
+			}
+		}
+	}
+}
+
+sub checklines_mk($) {
+	my ($lines) = @_;
+	my ($allowed_targets) = ({});
+	my ($substcontext) = PkgLint::SubstContext->new();
+
+	assert(@{$lines} != 0, "checklines_mk may only be called with non-empty lines.");
+	$opt_debug_trace and log_debug($lines->[0]->fname, NO_LINES, "checklines_mk()");
+
+	# Define global variables for the Makefile context.
+	$mkctx_indentations = [0];
+	$mkctx_target = undef;
+	$mkctx_for_variables = {};
+	$mkctx_vardef = {};
+	$mkctx_build_defs = {};
+	$mkctx_plist_vars = {};
+	$mkctx_tools = {%{get_predefined_tool_names()}};
+	$mkctx_varuse = {};
+
+	determine_used_variables($lines);
+
+	foreach my $prefix (qw(pre do post)) {
+		foreach my $action (qw(fetch extract patch tools wrapper configure build test install package clean)) {
+			$allowed_targets->{"${prefix}-${action}"} = true;
+		}
+	}
+
+	#
+	# In the first pass, all additions to BUILD_DEFS and USE_TOOLS
+	# are collected to make the order of the definitions irrelevant.
+	#
+
+	foreach my $line (@{$lines}) {
+		next unless $line->has("is_varassign");
+		my $varcanon = $line->get("varcanon");
+
+		if ($varcanon eq "BUILD_DEFS" || $varcanon eq "PKG_GROUPS_VARS" || $varcanon eq "PKG_USERS_VARS") {
+			foreach my $varname (split(qr"\s+", $line->get("value"))) {
+				$mkctx_build_defs->{$varname} = true;
+				$opt_debug_misc and $line->log_debug("${varname} is added to BUILD_DEFS.");
+			}
+
+		} elsif ($varcanon eq "PLIST_VARS") {
+			foreach my $id (split(qr"\s+", $line->get("value"))) {
+				$mkctx_plist_vars->{"PLIST.$id"} = true;
+				$opt_debug_misc and $line->log_debug("PLIST.${id} is added to PLIST_VARS.");
+				use_var($line, "PLIST.$id");
+			}
+
+		} elsif ($varcanon eq "USE_TOOLS") {
+			foreach my $tool (split(qr"\s+", $line->get("value"))) {
+				$tool =~ s/:(build|run)//;
+				$mkctx_tools->{$tool} = true;
+				$opt_debug_misc and $line->log_debug("${tool} is added to USE_TOOLS.");
+			}
+
+		} elsif ($varcanon eq "SUBST_VARS.*") {
+			foreach my $svar (split(/\s+/, $line->get("value"))) {
+				use_var($svar, varname_canon($svar));
+				$opt_debug_misc and $line->log_debug("varuse $svar");
+			}
+
+		} elsif ($varcanon eq "OPSYSVARS") {
+			foreach my $osvar (split(/\s+/, $line->get("value"))) {
+				use_var($line, "$osvar.*");
+				def_var($line, $osvar);
+			}
+		}
+	}
+
+	#
+	# In the second pass, all "normal" checks are done.
+	#
+
+	if (0 <= $#{$lines}) {
+		checkline_rcsid_regex($lines->[0], qr"^#\s+", "# ");
+	}
+
+	foreach my $line (@{$lines}) {
+		my $text = $line->text;
+
+		checkline_trailing_whitespace($line);
+
+		if ($line->has("is_empty")) {
+			$substcontext->check_end($line);
+
+		} elsif ($line->has("is_comment")) {
+			# No further checks.
+
+		} elsif ($text =~ regex_varassign) {
+			my ($varname, $op, undef, $comment) = ($1, $2, $3, $4);
+			my $space1 = substr($text, $+[1], $-[2] - $+[1]);
+			my $align = substr($text, $+[2], $-[3] - $+[2]);
+			my $value = $line->get("value");
+
+			if ($align !~ m"^(\t*|[ ])$") {
+				$opt_warn_space && $line->log_note("Alignment of variable values should be done with tabs, not spaces.");
+				my $prefix = "${varname}${space1}${op}";
+				my $aligned_len = tablen("${prefix}${align}");
+				if ($aligned_len % 8 == 0) {
+					my $tabalign = ("\t" x (($aligned_len - tablen($prefix) + 7) / 8));
+					$line->replace("${prefix}${align}", "${prefix}${tabalign}");
+				}
+			}
+			checkline_mk_varassign($line, $varname, $op, $value, $comment);
+			$substcontext->check_varassign($line, $varname, $op, $value);
+
+		} elsif ($text =~ regex_mk_shellcmd) {
+			my ($shellcmd) = ($1);
+			checkline_mk_shellcmd($line, $shellcmd);
+
+		} elsif ($text =~ regex_mk_include) {
+			my ($include, $includefile) = ($1, $2);
+
+			$opt_debug_include and $line->log_debug("includefile=${includefile}");
+			checkline_relative_path($line, $includefile, $include eq "include");
+
+			if ($includefile =~ m"../Makefile$") {
+				$line->log_error("Other Makefiles must not be included directly.");
+				$line->explain_warning(
+"If you want to include portions of another Makefile, extract",
+"the common parts and put them into a Makefile.common. After",
+"that, both this one and the other package should include the",
+"Makefile.common.");
+			}
+
+			if ($includefile eq "../../mk/bsd.prefs.mk") {
+				if ($line->fname =~ m"buildlink3\.mk$") {
+					$line->log_note("For efficiency reasons, please include bsd.fast.prefs.mk instead of bsd.prefs.mk.");
+				}
+				$seen_bsd_prefs_mk = true;
+			} elsif ($includefile eq "../../mk/bsd.fast.prefs.mk") {
+				$seen_bsd_prefs_mk = true;
+			}
+
+			if ($includefile =~ m"/x11-links/buildlink3\.mk$") {
+				$line->log_error("${includefile} must not be included directly. Include \"../../mk/x11.buildlink3.mk\" instead.");
+			}
+			if ($includefile =~ m"/jpeg/buildlink3\.mk$") {
+				$line->log_error("${includefile} must not be included directly. Include \"../../mk/jpeg.buildlink3.mk\" instead.");
+			}
+			if ($includefile =~ m"/intltool/buildlink3\.mk$") {
+				$line->log_warning("Please say \"USE_TOOLS+= intltool\" instead of this line.");
+			}
+			if ($includefile =~ m"(.*)/builtin\.mk$") {
+				my ($dir) = ($1);
+				$line->log_error("${includefile} must not be included directly. Include \"${dir}/buildlink3.mk\" instead.");
+			}
+
+		} elsif ($text =~ regex_mk_sysinclude) {
+			my ($includefile, $comment) = ($1, $2);
+
+			# No further action.
+
+		} elsif ($text =~ regex_mk_cond) {
+			my ($indent, $directive, $args, $comment) = ($1, $2, $3, $4);
+
+			use constant regex_directives_with_args => qr"^(?:if|ifdef|ifndef|elif|for|undef)$";
+
+			if ($directive =~ m"^(?:endif|endfor|elif|else)$") {
+				if ($#{$mkctx_indentations} >= 1) {
+					pop(@{$mkctx_indentations});
+				} else {
+					$line->log_error("Unmatched .${directive}.");
+				}
+			}
+
+			# Check the indentation
+			if ($indent ne " " x $mkctx_indentations->[-1]) {
+				$opt_warn_space and $line->log_note("This directive should be indented by ".$mkctx_indentations->[-1]." spaces.");
+			}
+
+			if ($directive eq "if" && $args =~ m"^!defined\([\w]+_MK\)$") {
+				push(@{$mkctx_indentations}, $mkctx_indentations->[-1]);
+
+			} elsif ($directive =~ m"^(?:if|ifdef|ifndef|for|elif|else)$") {
+				push(@{$mkctx_indentations}, $mkctx_indentations->[-1] + 2);
+			}
+
+			if ($directive =~ regex_directives_with_args && !defined($args)) {
+				$line->log_error("\".${directive}\" must be given some arguments.");
+
+			} elsif ($directive !~ regex_directives_with_args && defined($args)) {
+				$line->log_error("\".${directive}\" does not take arguments.");
+
+				if ($directive eq "else") {
+					$line->log_note("If you meant \"else if\", use \".elif\".");
+				}
+
+			} elsif ($directive eq "if" || $directive eq "elif") {
+				checkline_mk_cond($line, $args);
+
+			} elsif ($directive eq "ifdef" || $directive eq "ifndef") {
+				if ($args =~ m"\s") {
+					$line->log_error("The \".${directive}\" directive can only handle _one_ argument.");
+				} else {
+					$line->log_warning("The \".${directive}\" directive is deprecated. Please use \".if "
+						. (($directive eq "ifdef" ? "" : "!"))
+						. "defined(${args})\" instead.");
+				}
+
+			} elsif ($directive eq "for") {
+				if ($args =~ m"^(\S+(?:\s*\S+)*?)\s+in\s+(.*)$") {
+					my ($vars, $values) = ($1, $2);
+
+					foreach my $var (split(qr"\s+", $vars)) {
+						if (!$is_internal && $var =~ m"^_") {
+							$line->log_warning("Variable names starting with an underscore are reserved for internal pkgsrc use.");
+						}
+
+						if ($var =~ m"^[_a-z][_a-z0-9]*$") {
+							# Fine.
+						} elsif ($var =~ m"[A-Z]") {
+							$line->log_warning(".for variable names should not contain uppercase letters.");
+						} else {
+							$line->log_error("Invalid variable name \"${var}\".");
+						}
+
+						$mkctx_for_variables->{$var} = true;
+					}
+
+					# Check if any of the value's types is not guessed.
+					my $guessed = true;
+					foreach my $value (split(qr"\s+", $values)) { # XXX: too simple
+						if ($value =~ m"^\$\{(.*)\}") {
+							my $type = get_variable_type($line, $1);
+							if (defined($type) && !$type->is_guessed()) {
+								$guessed = false;
+							}
+						}
+					}
+
+					my $for_loop_type = PkgLint::Type->new(
+						LK_INTERNAL,
+						"Unchecked",
+						[[qr".*", "pu"]],
+						$guessed
+					);
+					my $for_loop_context = PkgLint::VarUseContext->new(
+						VUC_TIME_LOAD,
+						$for_loop_type,
+						VUC_SHELLWORD_FOR,
+						VUC_EXTENT_WORD
+					);
+					foreach my $var (@{extract_used_variables($line, $values)}) {
+						checkline_mk_varuse($line, $var, "", $for_loop_context);
+					}
+
+				}
+
+			} elsif ($directive eq "undef" && defined($args)) {
+				foreach my $var (split(qr"\s+", $args)) {
+					if (exists($mkctx_for_variables->{$var})) {
+						$line->log_note("Using \".undef\" after a \".for\" loop is unnecessary.");
+					}
+				}
+			}
+
+		} elsif ($text =~ regex_mk_dependency) {
+			my ($targets, $whitespace, $dependencies, $comment) = ($1, $2, $3, $4);
+
+			$opt_debug_misc and $line->log_debug("targets=${targets}, dependencies=${dependencies}");
+			$mkctx_target = $targets;
+
+			foreach my $source (split(/\s+/, $dependencies)) {
+				if ($source eq ".PHONY") {
+					foreach my $target (split(/\s+/, $targets)) {
+						$allowed_targets->{$target} = true;
+					}
+				}
+			}
+
+			foreach my $target (split(/\s+/, $targets)) {
+				if ($target eq ".PHONY") {
+					foreach my $dep (split(qr"\s+", $dependencies)) {
+						$allowed_targets->{$dep} = true;
+					}
+
+				} elsif ($target eq ".ORDER") {
+					# TODO: Check for spelling mistakes.
+
+				} elsif (!exists($allowed_targets->{$target})) {
+					$line->log_warning("Unusual target \"${target}\".");
+					$line->explain_warning(
+"If you really want to define your own targets, you can \"declare\"",
+"them by inserting a \".PHONY: my-target\" line before this line. This",
+"will tell make(1) to not interpret this target's name as a filename.");
+				}
+			}
+
+		} elsif ($text =~ m"^\.\s*(\S*)") {
+			my ($directive) = ($1);
+
+			$line->log_error("Unknown directive \".${directive}\".");
+
+		} elsif ($text =~ m"^ ") {
+			$line->log_warning("Makefile lines should not start with space characters.");
+			$line->explain_warning(
+"If you want this line to contain a shell program, use a tab",
+"character for indentation. Otherwise please remove the leading",
+"white-space.");
+
+		} else {
+			$line->log_error("[Internal] Unknown line format: $text");
+		}
+	}
+	if (@{$lines} > 0) {
+		$substcontext->check_end($lines->[-1]);
+	}
+
+	checklines_trailing_empty_lines($lines);
+
+	if ($#{$mkctx_indentations} != 0) {
+		$lines->[-1]->log_error("Directive indentation is not 0, but ".$mkctx_indentations->[-1]." at EOF.");
+	}
+
+	# Clean up global variables.
+	$mkctx_for_variables = undef;
+	$mkctx_indentations = undef;
+	$mkctx_target = undef;
+	$mkctx_vardef = undef;
+	$mkctx_build_defs = undef;
+	$mkctx_plist_vars = undef;
+	$mkctx_tools = undef;
+	$mkctx_varuse = undef;
+}
+
+sub checklines_buildlink3_inclusion($) {
+	my ($lines) = @_;
+	my ($included_files);
+
+	assert(@{$lines} != 0, "The lines array must be non-empty.");
+	$opt_debug_trace and log_debug($lines->[0]->fname, NO_LINES, "checklines_buildlink3_inclusion()");
+
+	if (!defined($pkgctx_bl3)) {
+		return;
+	}
+
+	# Collect all the included buildlink3.mk files from the file.
+	$included_files = {};
+	foreach my $line (@{$lines}) {
+		if ($line->text =~ regex_mk_include) {
+			my (undef, $file, $comment) = ($1, $2, $3);
+
+			if ($file =~ m"^\.\./\.\./(.*)/buildlink3\.mk") {
+				my ($bl3) = ($1);
+
+				$included_files->{$bl3} = $line;
+				if (!exists($pkgctx_bl3->{$bl3})) {
+					$line->log_warning("${bl3}/buildlink3.mk is included by this file but not by the package.");
+				}
+			}
+		}
+	}
+
+	# Print debugging messages for all buildlink3.mk files that are
+	# included by the package but not by this buildlink3.mk file.
+	foreach my $package_bl3 (sort(keys(%{$pkgctx_bl3}))) {
+		if (!exists($included_files->{$package_bl3})) {
+			$opt_debug_misc and $pkgctx_bl3->{$package_bl3}->log_debug("${package_bl3}/buildlink3.mk is included by the package but not by the buildlink3.mk file.");
+		}
+	}
+}
+
+#
+# Procedures to check a single file.
+#
+
+sub checkfile_ALTERNATIVES($) {
+	my ($fname) = @_;
+	my ($lines);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_ALTERNATIVES()");
+
+	checkperms($fname);
+	if (!($lines = load_file($fname))) {
+		log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+		return;
+	}
+}
+
+sub checkfile_buildlink3_mk($) {
+	my ($fname) = @_;
+	my ($lines, $lineno, $m);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_buildlink3_mk()");
+
+	checkperms($fname);
+	if (!($lines = load_lines($fname, true))) {
+		log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+		return;
+	}
+	if (@{$lines} == 0) {
+		log_error($fname, NO_LINES, "Must not be empty.");
+		return;
+	}
+
+	parselines_mk($lines);
+	checklines_mk($lines);
+
+	$lineno = 0;
+
+	# Header comments
+	while ($lineno <= $#{$lines} && (my $text = $lines->[$lineno]->text) =~ m"^#") {
+		if ($text =~ m"^# XXX") {
+			$lines->[$lineno]->log_note("Please read this comment and remove it if appropriate.");
+		}
+		$lineno++;
+	}
+	expect_empty_line($lines, \$lineno);
+
+	if (expect($lines, \$lineno, qr"^BUILDLINK_DEPMETHOD\.(\S+)\?=.*$")) {
+		$lines->[$lineno - 1]->log_warning("This line belongs inside the .ifdef block.");
+		while ($lines->[$lineno]->text eq "") {
+			$lineno++;
+		}
+	}
+
+	if (!($m = expect($lines, \$lineno, qr"^BUILDLINK_TREE\+=\s*(\S+)$"))) {
+		$lines->[$lineno]->log_warning("Expected a BUILDLINK_TREE line.");
+		return;
+	}
+
+	checklines_buildlink3_mk($lines, $lineno, $m->text(1));
+}
+
+sub checklines_buildlink3_mk($$$) {
+	my ($lines, $lineno, $pkgid) = @_;
+	my ($m);
+	my ($bl_PKGBASE_line, $bl_PKGBASE);
+	my ($bl_pkgbase_line, $bl_pkgbase);
+	my ($abi_line, $abi_pkg, $abi_version);
+	my ($api_line, $api_pkg, $api_version);
+
+	# First paragraph: Introduction of the package identifier
+	$bl_pkgbase_line = $lines->[$lineno - 1];
+	$bl_pkgbase = $pkgid;
+	$opt_debug_misc and $bl_pkgbase_line->log_debug("bl_pkgbase=${bl_pkgbase}");
+	expect_empty_line($lines, \$lineno);
+
+	# Second paragraph: multiple inclusion protection and introduction
+	# of the uppercase package identifier.
+	return unless ($m = expect_re($lines, \$lineno, qr"^\.if !defined\((\S+)_BUILDLINK3_MK\)$"));
+	$bl_PKGBASE_line = $lines->[$lineno - 1];
+	$bl_PKGBASE = $m->text(1);
+	$opt_debug_misc and $bl_PKGBASE_line->log_debug("bl_PKGBASE=${bl_PKGBASE}");
+	expect_re($lines, \$lineno, qr"^\Q$bl_PKGBASE\E_BUILDLINK3_MK:=$");
+	expect_empty_line($lines, \$lineno);
+
+	my $norm_bl_pkgbase = $bl_pkgbase;
+	$norm_bl_pkgbase =~ s/-/_/g;
+	$norm_bl_pkgbase = uc($norm_bl_pkgbase);
+	if ($norm_bl_pkgbase ne $bl_PKGBASE) {
+		$bl_PKGBASE_line->log_error("Package name mismatch between ${bl_PKGBASE} ...");
+		$bl_pkgbase_line->log_error("... and ${bl_pkgbase}.");
+	}
+	if (defined($effective_pkgbase) && $effective_pkgbase ne $bl_pkgbase) {
+		$bl_pkgbase_line->log_error("Package name mismatch between ${bl_pkgbase} ...");
+		$effective_pkgname_line->log_error("... and ${effective_pkgbase}.");
+	}
+
+	# Third paragraph: Package information.
+	my $if_level = 1; # the first .if is from the second paragraph.
+	while (true) {
+
+		if ($lineno > $#{$lines}) {
+			lines_log_warning($lines, $lineno, "Expected .endif");
+			return;
+		}
+
+		my $line = $lines->[$lineno];
+
+		if (($m = expect($lines, \$lineno, regex_varassign))) {
+			my ($varname, $value) = ($m->text(1), $m->text(3));
+			my $do_check = false;
+
+			if ($varname eq "BUILDLINK_ABI_DEPENDS.${bl_pkgbase}") {
+				$abi_line = $line;
+				if ($value =~ regex_dependency_lge) {
+					($abi_pkg, $abi_version) = ($1, $2);
+				} elsif ($value =~ regex_dependency_wildcard) {
+					($abi_pkg) = ($1);
+				} else {
+					$opt_debug_unchecked and $line->log_debug("Unchecked dependency pattern \"${value}\".");
+				}
+				$do_check = true;
+			}
+			if ($varname eq "BUILDLINK_API_DEPENDS.${bl_pkgbase}") {
+				$api_line = $line;
+				if ($value =~ regex_dependency_lge) {
+					($api_pkg, $api_version) = ($1, $2);
+				} elsif ($value =~ regex_dependency_wildcard) {
+					($api_pkg) = ($1);
+				} else {
+					$opt_debug_unchecked and $line->log_debug("Unchecked dependency pattern \"${value}\".");
+				}
+				$do_check = true;
+			}
+			if ($do_check && defined($abi_pkg) && defined($api_pkg)) {
+				if ($abi_pkg ne $api_pkg) {
+					$abi_line->log_warning("Package name mismatch between ${abi_pkg} ...");
+					$api_line->log_warning("... and ${api_pkg}.");
+				}
+			}
+			if ($do_check && defined($abi_version) && defined($api_version)) {
+				if (!dewey_cmp($abi_version, ">=", $api_version)) {
+					$abi_line->log_warning("ABI version (${abi_version}) should be at least ...");
+					$api_line->log_warning("... API version (${api_version}).");
+				}
+			}
+
+			if ($varname =~ m"^BUILDLINK_[\w_]+\.(.*)$") {
+				my ($varparam) = ($1);
+
+				if ($varparam ne $bl_pkgbase) {
+					$line->log_warning("Only buildlink variables for ${bl_pkgbase}, not ${varparam} may be set in this file.");
+				}
+			}
+
+			if ($varname eq "pkgbase") {
+				expect_re($lines, \$lineno, qr"^\.\s*include \"../../mk/pkg-build-options.mk\"$");
+			}
+
+			# TODO: More checks.
+
+		} elsif (expect($lines, \$lineno, qr"^(?:#.*)?$")) {
+			# Comments and empty lines are fine here.
+
+		} elsif (expect($lines, \$lineno, qr"^\.\s*include \"\.\./\.\./([^/]+/[^/]+)/buildlink3\.mk\"$")
+			|| expect($lines, \$lineno, qr"^\.\s*include \"\.\./\.\./mk/(\S+)\.buildlink3\.mk\"$")) {
+			# TODO: Maybe check dependency lines.
+
+		} elsif (expect($lines, \$lineno, qr"^\.if\s")) {
+			$if_level++;
+
+		} elsif (expect($lines, \$lineno, qr"^\.endif.*$")) {
+			$if_level--;
+			last if $if_level == 0;
+
+		} else {
+			$opt_debug_unchecked and lines_log_warning($lines, $lineno, "Unchecked line in third paragraph.");
+			$lineno++;
+		}
+	}
+	if (!defined($api_line)) {
+		$lines->[$lineno - 1]->log_warning("Definition of BUILDLINK_API_DEPENDS is missing.");
+	}
+	expect_empty_line($lines, \$lineno);
+
+	# Fourth paragraph: Cleanup, corresponding to the first paragraph.
+	return unless expect_re($lines, \$lineno, qr"^BUILDLINK_TREE\+=\s*-\Q$bl_pkgbase\E$");
+
+	if ($lineno <= $#{$lines}) {
+		$lines->[$lineno]->log_warning("The file should end here.");
+	}
+
+	checklines_buildlink3_inclusion($lines);
+}
+
+sub checkfile_DESCR($) {
+	my ($fname) = @_;
+	my ($maxchars, $maxlines) = (80, 24);
+	my ($lines);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_DESCR()");
+
+	checkperms($fname);
+	if (!($lines = load_file($fname))) {
+		log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+		return;
+	}
+	if (@{$lines} == 0) {
+		log_error($fname, NO_LINE_NUMBER, "Must not be empty.");
+		return;
+	}
+
+	foreach my $line (@{$lines}) {
+		checkline_length($line, $maxchars);
+		checkline_trailing_whitespace($line);
+		checkline_valid_characters($line, regex_validchars);
+		if ($line->text =~ m"\$\{") {
+			$line->log_warning("Variables are not expanded in the DESCR file.");
+		}
+	}
+	checklines_trailing_empty_lines($lines);
+
+	if (@{$lines} > $maxlines) {
+		my $line = $lines->[$maxlines];
+
+		$line->log_warning("File too long (should be no more than $maxlines lines).");
+		$line->explain_warning(
+"A common terminal size is 80x25 characters. The DESCR file should",
+"fit on one screen. It is also intended to give a _brief_ summary",
+"about the package's contents.");
+	}
+	autofix($lines);
+}
+
+sub checkfile_distinfo($) {
+	my ($fname) = @_;
+	my ($lines, %in_distinfo, $patches_dir, $di_is_committed, $current_fname, $is_patch, @seen_algs);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_distinfo()");
+
+	$di_is_committed = is_committed($fname);
+
+	checkperms($fname);
+	if (!($lines = load_file($fname))) {
+		log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+		return;
+	}
+
+	if (@{$lines} == 0) {
+		log_error($fname, NO_LINE_NUMBER, "Must not be empty.");
+		return;
+	}
+
+	checkline_rcsid($lines->[0], "");
+	if (1 <= $#{$lines} && $lines->[1]->text ne "") {
+		$lines->[1]->log_note("Empty line expected.");
+		$lines->[1]->explain_note("This is merely for aesthetical purposes.");
+	}
+
+	$patches_dir = $patchdir;
+	if (!defined($patches_dir) && -d "${current_dir}/patches") {
+		$patches_dir = "patches";
+	}
+
+	my $on_filename_change = sub($$) {
+		my ($line, $new_fname) = @_;
+
+		if (defined($current_fname)) {
+			my $seen_algs = join(", ", @seen_algs);
+			$opt_debug_misc and $line->log_debug("File ${current_fname} has checksums ${seen_algs}.");
+			if ($is_patch) {
+				if ($seen_algs ne "SHA1") {
+					$line->log_error("Expected SHA1 checksum for ${current_fname}, got ${seen_algs}.");
+				}
+			} else {
+				if ($seen_algs ne "SHA1, RMD160, Size" && $seen_algs ne "SHA1, RMD160, SHA512, Size") {
+					$line->log_error("Expected SHA1, RMD160, Size checksums for ${current_fname}, got ${seen_algs}.");
+				}
+			}
+		}
+
+		$is_patch = defined($new_fname) && $new_fname =~ m"^patch-.+$" && -f "${current_dir}/${patches_dir}/${new_fname}";
+		$current_fname = $new_fname;
+		@seen_algs = ();
+	};
+
+	foreach my $line (@{$lines}[2..$#{$lines}]) {
+		if ($line->text !~ m"^(\w+) \(([^)]+)\) = (.*)(?: bytes)?$") {
+			$line->log_error("Unknown line type.");
+			next;
+		}
+		my ($alg, $chksum_fname, $sum) = ($1, $2, $3);
+
+		if (!defined($current_fname) || $chksum_fname ne $current_fname) {
+			$on_filename_change->($line, $chksum_fname);
+		}
+
+		if ($chksum_fname !~ m"^\w") {
+			$line->log_error("All file names should start with a letter.");
+		}
+
+		# Inter-package check for differing distfile checksums.
+		if ($opt_check_global && !$is_patch) {
+			# Note: Perl-specific auto-population.
+			if (exists($ipc_distinfo->{$alg}->{$chksum_fname})) {
+				my $other = $ipc_distinfo->{$alg}->{$chksum_fname};
+
+				if ($other->[1] eq $sum) {
+					# Fine.
+				} else {
+					$line->log_error("The ${alg} checksum for ${chksum_fname} differs ...");
+					$other->[0]->log_error("... from this one.");
+				}
+			} else {
+				$ipc_distinfo->{$alg}->{$chksum_fname} = [$line, $sum];
+			}
+		}
+
+		push(@seen_algs, $alg);
+
+		if ($is_patch && defined($patches_dir) && !(defined($distinfo_file) && $distinfo_file eq "./../../lang/php5/distinfo")) {
+			my $fname = "${current_dir}/${patches_dir}/${chksum_fname}";
+			if ($di_is_committed && !is_committed($fname)) {
+				$line->log_warning("${patches_dir}/${chksum_fname} is registered in distinfo but not added to CVS.");
+			}
+
+			if (open(my $patchfile, "<", $fname)) {
+				my $sha1 = Digest::SHA1->new();
+				while (defined(my $patchline = <$patchfile>)) {
+					$sha1->add($patchline) unless $patchline =~ m"\$[N]etBSD";
+				}
+				close($patchfile);
+				my $chksum = $sha1->hexdigest();
+				if ($sum ne $chksum) {
+					$line->log_error("${alg} checksum of ${chksum_fname} differs (expected ${sum}, got ${chksum}). Rerun '".conf_make." makepatchsum'.");
+				}
+			} else {
+				$line->log_warning("${chksum_fname} does not exist.");
+				$line->explain_warning(
+"All patches that are mentioned in a distinfo file should actually exist.",
+"What's the use of a checksum if there is no file to check?");
+			}
+		}
+		$in_distinfo{$chksum_fname} = true;
+
+	}
+	$on_filename_change->(PkgLint::Line->new($fname, NO_LINE_NUMBER, "", []), undef);
+	checklines_trailing_empty_lines($lines);
+
+	if (defined($patches_dir)) {
+		foreach my $patch (glob("${current_dir}/${patches_dir}/patch-*")) {
+			$patch = basename($patch);
+			if (!exists($in_distinfo{$patch})) {
+				log_error($fname, NO_LINE_NUMBER, "$patch is not recorded. Rerun '".conf_make." makepatchsum'.");
+			}
+		}
+	}
+}
+
+sub checkfile_extra($) {
+	my ($fname) = @_;
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_extra()");
+
+	my $lines = load_file($fname) or return log_error($fname, NO_LINE_NUMBER, "Could not be read.");
+	checklines_trailing_empty_lines($lines);
+	checkperms($fname);
+}
+
+sub checkfile_INSTALL($) {
+	my ($fname) = @_;
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_INSTALL()");
+
+	checkperms($fname);
+	my $lines = load_file($fname) or return log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+}
+
+sub checkfile_MESSAGE($) {
+	my ($fname) = @_;
+
+	my @explanation = (
+		"A MESSAGE file should consist of a header line, having 75 \"=\"",
+		"characters, followed by a line containing only the RCS Id, then an",
+		"empty line, your text and finally the footer line, which is the",
+		"same as the header line.");
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_MESSAGE()");
+
+	checkperms($fname);
+	my $lines = load_file($fname) or return log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+
+	if (@{$lines} < 3) {
+		log_warning($fname, NO_LINE_NUMBER, "File too short.");
+		explain_warning($fname, NO_LINE_NUMBER, @explanation);
+		return;
+	}
+	if ($lines->[0]->text ne "=" x 75) {
+		$lines->[0]->log_warning("Expected a line of exactly 75 \"=\" characters.");
+		explain_warning($fname, NO_LINE_NUMBER, @explanation);
+	}
+	checkline_rcsid($lines->[1], "");
+	foreach my $line (@{$lines}) {
+		checkline_length($line, 80);
+		checkline_trailing_whitespace($line);
+		checkline_valid_characters($line, regex_validchars);
+	}
+	if ($lines->[-1]->text ne "=" x 75) {
+		$lines->[-1]->log_warning("Expected a line of exactly 75 \"=\" characters.");
+		explain_warning($fname, NO_LINE_NUMBER, @explanation);
+	}
+	checklines_trailing_empty_lines($lines);
+}
+
+sub checkfile_mk($) {
+	my ($fname) = @_;
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_mk()");
+
+	checkperms($fname);
+	my $lines = load_lines($fname, true) or return log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+
+	parselines_mk($lines);
+	checklines_mk($lines);
+	autofix($lines);
+}
+
+sub checkfile_package_Makefile($$) {
+	my ($fname, $lines) = @_;
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_package_Makefile(..., ...)");
+
+	checkperms($fname);
+
+	if (!exists($pkgctx_vardef->{"PLIST_SRC"})
+	    && !exists($pkgctx_vardef->{"GENERATE_PLIST"})
+	    && !exists($pkgctx_vardef->{"META_PACKAGE"})
+	    && defined($pkgdir)
+	    && !-f "${current_dir}/$pkgdir/PLIST"
+	    && !-f "${current_dir}/$pkgdir/PLIST.common") {
+		log_warning($fname, NO_LINE_NUMBER, "Neither PLIST nor PLIST.common exist, and PLIST_SRC is unset. Are you sure PLIST handling is ok?");
+	}
+
+	if ((exists($pkgctx_vardef->{"NO_CHECKSUM"}) || $pkgctx_vardef->{"META_PACKAGE"}) && is_emptydir("${current_dir}/${patchdir}")) {
+		if (-f "${current_dir}/${distinfo_file}") {
+			log_warning("${current_dir}/${distinfo_file}", NO_LINE_NUMBER, "This file should not exist if NO_CHECKSUM or META_PACKAGE is set.");
+		}
+	} else {
+		if (!-f "${current_dir}/${distinfo_file}") {
+			log_warning("${current_dir}/${distinfo_file}", NO_LINE_NUMBER, "File not found. Please run '".conf_make." makesum'.");
+		}
+	}
+
+	if (exists($pkgctx_vardef->{"REPLACE_PERL"}) && exists($pkgctx_vardef->{"NO_CONFIGURE"})) {
+		$pkgctx_vardef->{"REPLACE_PERL"}->log_warning("REPLACE_PERL is ignored when ...");
+		$pkgctx_vardef->{"NO_CONFIGURE"}->log_warning("... NO_CONFIGURE is set.");
+	}
+
+	if (!exists($pkgctx_vardef->{"LICENSE"})) {
+		log_error($fname, NO_LINE_NUMBER, "Each package must define its LICENSE.");
+	}
+
+	if (exists($pkgctx_vardef->{"GNU_CONFIGURE"}) && exists($pkgctx_vardef->{"USE_LANGUAGES"})) {
+		my $languages_line = $pkgctx_vardef->{"USE_LANGUAGES"};
+		my $value = $languages_line->get("value");
+
+		if ($languages_line->has("comment") && $languages_line->get("comment") =~ m"\b(?:c|empty|none)\b"i) {
+			# Don't emit a warning, since the comment
+			# probably contains a statement that C is
+			# really not needed.
+
+		} elsif ($value !~ m"(?:^|\s+)(?:c|c99|objc)(?:\s+|$)") {
+			$pkgctx_vardef->{"GNU_CONFIGURE"}->log_warning("GNU_CONFIGURE almost always needs a C compiler, ...");
+			$languages_line->log_warning("... but \"c\" is not added to USE_LANGUAGES.");
+		}
+	}
+
+	my $distname_line = $pkgctx_vardef->{"DISTNAME"};
+	my $pkgname_line = $pkgctx_vardef->{"PKGNAME"};
+
+	my $distname = defined($distname_line) ? $distname_line->get("value") : undef;
+	my $pkgname = defined($pkgname_line) ? $pkgname_line->get("value") : undef;
+	my $nbpart = get_nbpart();
+
+	# Let's do some tricks to get the proper value of the package
+	# name more often.
+	if (defined($distname) && defined($pkgname)) {
+		$pkgname =~ s/\$\{DISTNAME\}/$distname/;
+
+		if ($pkgname =~ m"^(.*)\$\{DISTNAME:S(.)([^:]*)\2([^:]*)\2(g?)\}(.*)$") {
+			my ($before, $separator, $old, $new, $mod, $after) = ($1, $2, $3, $4, $5, $6);
+			my $newname = $distname;
+			$old = quotemeta($old);
+			$old =~ s/^\\\^/^/;
+			$old =~ s/\\\$$/\$/;
+			if ($mod eq "g") {
+				$newname =~ s/$old/$new/g;
+			} else {
+				$newname =~ s/$old/$new/;
+			}
+			$opt_debug_misc and $pkgname_line->log_debug("old pkgname=$pkgname");
+			$pkgname = $before . $newname . $after;
+			$opt_debug_misc and $pkgname_line->log_debug("new pkgname=$pkgname");
+		}
+	}
+
+	if (defined($pkgname) && defined($distname) && $pkgname eq $distname) {
+		$pkgname_line->log_note("PKGNAME is \${DISTNAME} by default. You probably don't need to define PKGNAME.");
+	}
+
+	if (!defined($pkgname) && defined($distname) && $distname !~ regex_unresolved && $distname !~ regex_pkgname) {
+		$distname_line->log_warning("As DISTNAME is not a valid package name, please define the PKGNAME explicitly.");
+	}
+
+	($effective_pkgname, $effective_pkgname_line, $effective_pkgbase, $effective_pkgversion)
+		= (defined($pkgname) && $pkgname !~ regex_unresolved && $pkgname =~ regex_pkgname) ? ($pkgname.$nbpart, $pkgname_line, $1, $2)
+		: (defined($distname) && $distname !~ regex_unresolved && $distname =~ regex_pkgname) ? ($distname.$nbpart, $distname_line, $1, $2)
+		: (undef, undef, undef, undef);
+	if (defined($effective_pkgname_line)) {
+		$opt_debug_misc and $effective_pkgname_line->log_debug("Effective name=${effective_pkgname} base=${effective_pkgbase} version=${effective_pkgversion}.");
+		# XXX: too many false positives
+		if (false && $pkgpath =~ m"/([^/]+)$" && $effective_pkgbase ne $1) {
+			$effective_pkgname_line->log_warning("Mismatch between PKGNAME ($effective_pkgname) and package directory ($1).");
+		}
+	}
+
+	checkpackage_possible_downgrade();
+
+	if (!exists($pkgctx_vardef->{"COMMENT"})) {
+		log_warning($fname, NO_LINE_NUMBER, "No COMMENT given.");
+	}
+
+	if (exists($pkgctx_vardef->{"USE_IMAKE"}) && exists($pkgctx_vardef->{"USE_X11"})) {
+		$pkgctx_vardef->{"USE_IMAKE"}->log_note("USE_IMAKE makes ...");
+		$pkgctx_vardef->{"USE_X11"}->log_note("... USE_X11 superfluous.");
+	}
+
+	if (defined($effective_pkgbase)) {
+
+		foreach my $suggested_update (@{get_suggested_package_updates()}) {
+			my ($line, $suggbase, $suggver, $suggcomm) = @{$suggested_update};
+			my $comment = (defined($suggcomm) ? " (${suggcomm})" : "");
+
+			next unless $effective_pkgbase eq $suggbase;
+
+			if (dewey_cmp($effective_pkgversion, "<", $suggver)) {
+				$effective_pkgname_line->log_warning("This package should be updated to ${suggver}${comment}.");
+				$effective_pkgname_line->explain_warning(
+"The wishlist for package updates in doc/TODO mentions that a newer",
+"version of this package is available.");
+			}
+			if (dewey_cmp($effective_pkgversion, "==", $suggver)) {
+				$effective_pkgname_line->log_note("The update request to ${suggver} from doc/TODO${comment} has been done.");
+			}
+			if (dewey_cmp($effective_pkgversion, ">", $suggver)) {
+				$effective_pkgname_line->log_note("This package is newer than the update request to ${suggver}${comment}.");
+			}
+		}
+	}
+
+	checklines_mk($lines);
+	checklines_package_Makefile_varorder($lines);
+	autofix($lines);
+}
+
+#include PkgLint/Patches.pm
+
+sub checkfile_PLIST($) {
+	my ($fname) = @_;
+	my ($lines, $last_file_seen);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile_PLIST()");
+
+	checkperms($fname);
+	if (!($lines = load_file($fname))) {
+		log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+		return;
+	}
+	if (@{$lines} == 0) {
+		log_error($fname, NO_LINE_NUMBER, "Must not be empty.");
+		return;
+	}
+	checkline_rcsid($lines->[0], "\@comment ");
+
+	if (@$lines == 1) {
+		$lines->[0]->log_warning("PLIST files shouldn't be empty.");
+		$lines->[0]->explain_warning(
+"One reason for empty PLISTs is that this is a newly created package",
+"and that the author didn't run \"bmake print-PLIST\" after installing",
+"the files.",
+"",
+"Another reason, common for Perl packages, is that the final PLIST is",
+"automatically generated. Since the source PLIST is not used at all,",
+"you can remove it.",
+"",
+"Meta packages also don't need a PLIST file.");
+	}
+
+	# Get the list of all files from the PLIST.
+	my $all_files = {};
+	my $all_dirs = {};
+	my $extra_lines = [];
+	if (basename($fname) eq "PLIST.common_end") {
+		my $common_lines = load_file(dirname($fname) . "/PLIST.common");
+		if ($common_lines) {
+			$extra_lines = $common_lines;
+		}
+	}
+
+	foreach my $line (@{$extra_lines}, @{$lines}) {
+		my $text = $line->text;
+
+		if (index($text, '${') != -1 && $text =~ m"\$\{([\w_]+)\}(.*)") {
+			if (defined($pkgctx_plist_subst_cond) && exists($pkgctx_plist_subst_cond->{$1})) {
+				$opt_debug_misc and $line->log_debug("Removed PLIST_SUBST conditional $1.");
+				$text = $2;
+			}
+		}
+
+		if ($text =~ m"^[\w\$]") {
+			$all_files->{$text} = $line;
+			my $dir = $text;
+			while ($dir =~ s,/[^/]+$,,) {
+				$all_dirs->{$dir} = $line;
+			}
+		}
+		if (substr($text, 0, 1) eq '@' && $text =~ m"^\@exec \$\{MKDIR\} %D/(.*)$") {
+			my $dir = $1;
+			do {
+				$all_dirs->{$dir} = $line;
+			} while ($dir =~ s,/[^/]+$,,);
+		}
+	}
+
+	foreach my $line (@{$lines}) {
+		my $text = $line->text;
+
+		if ($text =~ /\s$/) {
+			$line->log_error("pkgsrc does not support filenames ending in white-space.");
+			$line->explain_error(
+"Each character in the PLIST is relevant, even trailing white-space.");
+		}
+
+		# @foo directives.
+		if (index($text, '@') != -1 && $text =~ /^(?:\$\{[\w_]+\})?\@([a-z-]+)\s+(.*)/) {
+			my ($cmd, $arg) = ($1, $2);
+
+			if ($cmd eq "unexec" && $arg =~ m"^(rmdir|\$\{RMDIR\} \%D/)(.*)") {
+				my ($rmdir, $rest) = ($1, $2);
+				if ($rest !~ m"(?:true|\$\{TRUE\})") {
+					$line->log_warning("Please remove this line. It is no longer necessary.");
+				}
+
+			} elsif (($cmd eq "exec" || $cmd eq "unexec")) {
+				if ($arg =~ /(?:install-info|\$\{INSTALL_INFO\})/) {
+					$line->log_warning("\@exec/unexec install-info is deprecated.");
+
+				} elsif ($arg =~ /ldconfig/ && $arg !~ m"/usr/bin/true") {
+					$line->log_error("ldconfig must be used with \"||/usr/bin/true\".");
+				}
+
+			} elsif ($cmd eq "comment") {
+				# nothing to do
+
+			} elsif ($cmd eq "dirrm") {
+				$line->log_warning("\@dirrm is obsolete. Please remove this line.");
+				$line->explain_warning(
+"Directories are removed automatically when they are empty.",
+"When a package needs an empty directory, it can use the \@pkgdir",
+"command in the PLIST");
+			} elsif ($cmd eq "imake-man") {
+				my (@args) = split(/\s+/, $arg);
+				if (@args != 3) {
+					$line->log_warning("Invalid number of arguments for imake-man.");
+				} else {
+					if ($args[2] eq "\${IMAKE_MANNEWSUFFIX}") {
+						warn_about_PLIST_imake_mannewsuffix($line);
+					}
+				}
+
+			} elsif ($cmd eq "pkgdir") {
+				# TODO: What can we check here?
+
+			} else {
+				$line->log_warning("Unknown PLIST directive \"\@$cmd\".");
+			}
+
+		# Pathnames.
+		} elsif ($text =~ m"^([A-Za-z0-9\$].*)/([^/]+)$") {
+			my ($dirname, $basename) = ($1, $2);
+
+			if ($opt_warn_plist_sort && $text =~ m"^\w" && $text !~ regex_unresolved) {
+				if (defined($last_file_seen)) {
+					if ($last_file_seen gt $text) {
+						$line->log_warning("${text} should be sorted before ${last_file_seen}.");
+						$line->explain_warning(
+"For aesthetic reasons, the files in the PLIST should be sorted",
+"alphabetically.");
+					} elsif ($last_file_seen eq $text) {
+						$line->log_warning("Duplicate filename.");
+					}
+				}
+				$last_file_seen = $text;
+			}
+
+			if (index($basename, '${IMAKE_MANNEWSUFFIX}') != -1) {
+				warn_about_PLIST_imake_mannewsuffix($line);
+			}
+
+			if (substr($dirname, 0, 4) eq "bin/") {
+				$line->log_warning("The bin/ directory should not have subdirectories.");
+
+			} elsif ($dirname eq "bin") {
+
+				if (exists($all_files->{"man/man1/${basename}.1"})) {
+					# Fine.
+				} elsif (exists($all_files->{"man/man6/${basename}.6"})) {
+					# Fine.
+				} elsif (exists($all_files->{"\${IMAKE_MAN_DIR}/${basename}.\${IMAKE_MANNEWSUFFIX}"})) {
+					# Fine.
+				} else {
+					$opt_warn_extra and $line->log_warning("Manual page missing for bin/${basename}.");
+					$opt_warn_extra and $line->explain_warning(
+"All programs that can be run directly by the user should have a manual",
+"page for quick reference. The programs in the bin/ directory should have",
+"corresponding manual pages in section 1 (filename program.1), not in",
+"section 8.");
+				}
+
+			} elsif (substr($text, 0, 4) eq "doc/") {
+				$line->log_error("Documentation must be installed under share/doc, not doc.");
+
+			} elsif (substr($text, 0, 9) eq "etc/rc.d/") {
+				$line->log_error("RCD_SCRIPTS must not be registered in the PLIST. Please use the RCD_SCRIPTS framework.");
+
+			} elsif (substr($text, 0, 4) eq "etc/") {
+				my $f = "mk/pkginstall/bsd.pkginstall.mk";
+
+				assert(-f "${cwd_pkgsrcdir}/${f}", "${cwd_pkgsrcdir}/${f} is not a regular file.");
+				$line->log_error("Configuration files must not be registered in the PLIST. Please use the CONF_FILES framework, which is described in ${f}.");
+
+			} elsif (substr($text, 0, 8) eq "include/" && $text =~ m"^include/.*\.(?:h|hpp)$") {
+				# Fine.
+
+			} elsif ($text eq "info/dir") {
+				$line->log_error("\"info/dir\" must not be listed. Use install-info to add/remove an entry.");
+
+			} elsif (substr($text, 0, 5) eq "info/" && length($text) > 5) {
+				if (defined($pkgctx_vardef) && !exists($pkgctx_vardef->{"INFO_FILES"})) {
+					$line->log_warning("Packages that install info files should set INFO_FILES.");
+				}
+
+			} elsif (defined($effective_pkgbase) && $text =~ m"^lib/\Q${effective_pkgbase}\E/") {
+				# Fine.
+
+			} elsif (substr($text, 0, 11) eq "lib/locale/") {
+				$line->log_error("\"lib/locale\" must not be listed. Use \${PKGLOCALEDIR}/locale and set USE_PKGLOCALEDIR instead.");
+
+			} elsif (substr($text, 0, 4) eq "lib/" && $text =~ m"^(lib/(?:.*/)*)([^/]+)\.(so|a|la)$") {
+				my ($dir, $lib, $ext) = ($1, $2, $3);
+
+				if ($dir eq "lib/" && $lib !~ m"^lib") {
+					$opt_warn_extra and $line->log_warning("Library filename does not start with \"lib\".");
+				}
+				if ($ext eq "la") {
+					if (defined($pkgctx_vardef) && !exists($pkgctx_vardef->{"USE_LIBTOOL"})) {
+						$line->log_warning("Packages that install libtool libraries should define USE_LIBTOOL.");
+					}
+				}
+
+			} elsif (substr($text, 0, 4) eq "man/" && $text =~ m"^man/(cat|man)(\w+)/(.*?)\.(\w+)(\.gz)?$") {
+				my ($cat_or_man, $section, $manpage, $ext, $gz) = ($1, $2, $3, $4, $5);
+
+				if ($section !~ m"^[\dln]$") {
+					$line->log_warning("Unknown section \"${section}\" for manual page.");
+				}
+
+				if ($cat_or_man eq "cat" && !exists($all_files->{"man/man${section}/${manpage}.${section}"})) {
+					$line->log_warning("Preformatted manual page without unformatted one.");
+				}
+
+				if ($cat_or_man eq "cat") {
+					if ($ext ne "0") {
+						$line->log_warning("Preformatted manual pages should end in \".0\".");
+					}
+				} else {
+					if ($section ne $ext) {
+						$line->log_warning("Mismatch between the section (${section}) and extension (${ext}) of the manual page.");
+					}
+				}
+
+				if (defined($gz)) {
+					$line->log_note("The .gz extension is unnecessary for manual pages.");
+					$line->explain_note(
+"Whether the manual pages are installed in compressed form or not is",
+"configured by the pkgsrc user. Compression and decompression takes place",
+"automatically, no matter if the .gz extension is mentioned in the PLIST",
+"or not.");
+				}
+
+			} elsif (substr($text, 0, 7) eq "man/cat") {
+				$line->log_warning("Invalid filename \"${text}\" for preformatted manual page.");
+
+			} elsif (substr($text, 0, 7) eq "man/man") {
+				$line->log_warning("Invalid filename \"${text}\" for unformatted manual page.");
+
+			} elsif (substr($text, 0, 5) eq "sbin/") {
+				my $binname = substr($text, 5);
+
+				if (!exists($all_files->{"man/man8/${binname}.8"})) {
+					$opt_warn_extra and $line->log_warning("Manual page missing for sbin/${binname}.");
+					$opt_warn_extra and $line->explain_warning(
+"All programs that can be run directly by the user should have a manual",
+"page for quick reference. The programs in the sbin/ directory should have",
+"corresponding manual pages in section 8 (filename program.8), not in",
+"section 1.");
+				}
+
+			} elsif (substr($text, 0, 6) eq "share/" && $text =~ m"^share/applications/.*\.desktop$") {
+				my $f = "../../sysutils/desktop-file-utils/desktopdb.mk";
+				if (defined($pkgctx_included) && !exists($pkgctx_included->{$f})) {
+					$line->log_warning("Packages that install a .desktop entry may .include \"$f\".");
+					$line->explain_warning(
+"If *.desktop files contain MimeType keys, global MIME Type registory DB",
+"must be updated by desktop-file-utils.",
+"Otherwise, this warning is harmless.");
+				}
+
+			} elsif (substr($text, 0, 6) eq "share/" && $pkgpath ne "graphics/hicolor-icon-theme" && $text =~ m"^share/icons/hicolor(?:$|/)") {
+				my $f = "../../graphics/hicolor-icon-theme/buildlink3.mk";
+				if (defined($pkgctx_included) && !exists($pkgctx_included->{$f})) {
+					$line->log_error("Please .include \"$f\" in the Makefile");
+					$line->explain_error(
+"If hicolor icon themes are installed, icon theme cache must be",
+"maintained. The hicolor-icon-theme package takes care of that.");
+				}
+
+			} elsif (substr($text, 0, 6) eq "share/" && $pkgpath ne "graphics/gnome-icon-theme" && $text =~ m"^share/icons/gnome(?:$|/)") {
+				my $f = "../../graphics/gnome-icon-theme/buildlink3.mk";
+				if (defined($pkgctx_included) && !exists($pkgctx_included->{$f})) {
+					$line->log_error("Please .include \"$f\"");
+					$line->explain_error(
+"If Gnome icon themes are installed, icon theme cache must be maintained.");
+				}
+			} elsif ($dirname eq "share/aclocal" && $basename =~ m"\.m4$") {
+				# Fine.
+
+			} elsif (substr($text, 0, 15) eq "share/doc/html/") {
+				$opt_warn_plist_depr and $line->log_warning("Use of \"share/doc/html\" is deprecated. Use \"share/doc/\${PKGBASE}\" instead.");
+
+			} elsif (defined($effective_pkgbase) && $text =~ m"^share/(?:doc/|examples/|)\Q${effective_pkgbase}\E/") {
+				# Fine.
+
+			} elsif ($pkgpath ne "graphics/hicolor-icon-theme" && $text =~ m"^share/icons/hicolor/icon-theme\.cache") {
+				$line->log_error("Please .include \"../../graphics/hicolor-icon-theme/buildlink3.mk\" and remove this line.");
+
+			} elsif (substr($text, 0, 11) eq "share/info/") {
+				$line->log_warning("Info pages should be installed into info/, not share/info/.");
+				$line->explain_warning(
+"To fix this, you should add INFO_FILES=yes to the package Makefile.");
+
+			} elsif (substr($text, -3) eq ".mo" && $text =~ m"^share/locale/[\w\@_]+/LC_MESSAGES/[^/]+\.mo$") {
+				# Fine.
+
+			} elsif (substr($text, 0, 10) eq "share/man/") {
+				$line->log_warning("Man pages should be installed into man/, not share/man/.");
+
+			} else {
+				$opt_debug_unchecked and $line->log_debug("Unchecked pathname \"${text}\".");
+			}
+
+			if ($text =~ /\$\{PKGLOCALEDIR}/ && defined($pkgctx_vardef) && !exists($pkgctx_vardef->{"USE_PKGLOCALEDIR"})) {
+				$line->log_warning("PLIST contains \${PKGLOCALEDIR}, but USE_PKGLOCALEDIR was not found.");
+			}
+
+			if (index($text, "/CVS/") != -1) {
+				$line->log_warning("CVS files should not be in the PLIST.");
+			}
+			if (substr($text, -5) eq ".orig") {
+				$line->log_warning(".orig files should not be in the PLIST.");
+			}
+			if (substr($text, -14) eq "/perllocal.pod") {
+				$line->log_warning("perllocal.pod files should not be in the PLIST.");
+				$line->explain_warning(
+"This file is handled automatically by the INSTALL/DEINSTALL scripts,",
+"since its contents changes frequently.");
+			}
+
+			if ($text =~ m"^(.*)(\.a|\.so[0-9.]*)$") {
+				my ($basename, $ext) = ($1, $2);
+
+				if (exists($all_files->{"${basename}.la"})) {
+					$line->log_warning("Redundant library found. The libtool library is in line " . $all_files->{"${basename}.la"}->lines . ".");
+				}
+			}
+
+		} elsif ($text =~ m"^\$\{[\w_]+\}$") {
+			# A variable on its own line.
+
+		} else {
+			$line->log_error("Unknown line type.");
+		}
+	}
+	checklines_trailing_empty_lines($lines);
+	autofix($lines);
+}
+
+sub checkfile($) {
+	my ($fname) = @_;
+	my ($st, $basename);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkfile()");
+
+	$basename = basename($fname);
+	if ($basename =~ m"^(?:work.*|.*~|.*\.orig|.*\.rej)$") {
+		if ($opt_import) {
+			log_error($fname, NO_LINE_NUMBER, "Must be cleaned up before committing the package.");
+		}
+		return;
+	}
+
+	if (!($st = lstat($fname))) {
+		log_error($fname, NO_LINE_NUMBER, "$!");
+		return;
+	}
+	if (S_ISDIR($st->mode)) {
+		if ($basename eq "files" || $basename eq "patches" || $basename eq "CVS") {
+			# Ok
+		} elsif ($fname =~ m"(?:^|/)files/[^/]*$") {
+			# Ok
+
+		} elsif (!is_emptydir($fname)) {
+			log_warning($fname, NO_LINE_NUMBER, "Unknown directory name.");
+		}
+
+	} elsif (S_ISLNK($st->mode)) {
+		if ($basename !~ m"^work") {
+			log_warning($fname, NO_LINE_NUMBER, "Unknown symlink name.");
+		}
+
+	} elsif (!S_ISREG($st->mode)) {
+		log_error($fname, NO_LINE_NUMBER, "Only files and directories are allowed in pkgsrc.");
+
+	} elsif ($basename eq "ALTERNATIVES") {
+		$opt_check_ALTERNATIVES and checkfile_ALTERNATIVES($fname);
+
+	} elsif ($basename eq "buildlink3.mk") {
+		$opt_check_bl3 and checkfile_buildlink3_mk($fname);
+
+	} elsif ($basename =~ m"^DESCR") {
+		$opt_check_DESCR and checkfile_DESCR($fname);
+
+	} elsif ($basename =~ m"^distinfo") {
+		$opt_check_distinfo and checkfile_distinfo($fname);
+
+	} elsif ($basename eq "DEINSTALL" || $basename eq "INSTALL") {
+		$opt_check_INSTALL and checkfile_INSTALL($fname);
+
+	} elsif ($basename =~ m"^MESSAGE") {
+		$opt_check_MESSAGE and checkfile_MESSAGE($fname);
+
+	} elsif ($basename =~ m"^patch-[-A-Za-z0-9_.~+]*[A-Za-z0-9_]$") {
+		$opt_check_patches and checkfile_patch($fname);
+
+	} elsif ($fname =~ m"(?:^|/)patches/manual[^/]*$") {
+		$opt_debug_unchecked and log_debug($fname, NO_LINE_NUMBER, "Unchecked file \"${fname}\".");
+
+	} elsif ($fname =~ m"(?:^|/)patches/[^/]*$") {
+		log_warning($fname, NO_LINE_NUMBER, "Patch files should be named \"patch-\", followed by letters, '-', '_', '.', and digits only.");
+
+	} elsif ($basename =~ m"^(?:.*\.mk|Makefile.*)$" and not $fname =~ m,files/, and not $fname =~ m,patches/,) {
+		$opt_check_mk and checkfile_mk($fname);
+
+	} elsif ($basename =~ m"^PLIST") {
+		$opt_check_PLIST and checkfile_PLIST($fname);
+
+	} elsif ($basename eq "TODO" || $basename eq "README") {
+		# Ok
+
+	} elsif ($basename =~ m"^CHANGES-.*") {
+		load_doc_CHANGES($fname);
+
+	} elsif (!-T $fname) {
+		log_warning($fname, NO_LINE_NUMBER, "Unexpectedly found a binary file.");
+
+	} elsif ($fname =~ m"(?:^|/)files/[^/]*$") {
+		# Ok
+	} else {
+		log_warning($fname, NO_LINE_NUMBER, "Unexpected file found.");
+		$opt_check_extra and checkfile_extra($fname);
+	}
+}
+
+sub my_split($$) {
+	my ($delimiter, $s) = @_;
+	my ($pos, $next, @result);
+
+	$pos = 0;
+	for ($pos = 0; $pos != -1; $pos = $next) {
+		$next = index($s, $delimiter, $pos);
+		push @result, (($next == -1) ? substr($s, $pos) : substr($s, $pos, $next - $pos));
+		if ($next != -1) {
+			$next += length($delimiter);
+		}
+	}
+	return @result;
+}
+
+# Checks that the files in the directory are in sync with CVS's status.
+#
+sub checkdir_CVS($) {
+	my ($fname) = @_;
+
+	my $cvs_entries = load_file("$fname/CVS/Entries");
+	my $cvs_entries_log = load_file("$fname/CVS/Entries.Log");
+	return unless $cvs_entries;
+
+	foreach my $line (@$cvs_entries) {
+		my ($type, $fname, $mtime, $date, $keyword_mode, $tag, $undef) = my_split("/", $line->text);
+		next if ($type eq "D" && !defined($fname));
+		assert(false, "Unknown line format: " . $line->text)
+			unless $type eq "" || $type eq "D";
+		assert(false, "Unknown line format: " . $line->text)
+			unless defined($tag);
+		assert(false, "Unknown line format: " . $line->text)
+			unless defined($keyword_mode);
+		assert(false, "Unknown line format: " . $line->text)
+			if defined($undef);
+	}
+}
+
+#
+# Procedures to check a directory including the files in it.
+#
+
+sub checkdir_root() {
+	my ($fname) = "${current_dir}/Makefile";
+	my ($lines, $prev_subdir, @subdirs);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkdir_root()");
+
+	if (!($lines = load_lines($fname, true))) {
+		log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+		return;
+	}
+
+	parselines_mk($lines);
+	if (0 <= $#{$lines}) {
+		checkline_rcsid_regex($lines->[0], qr"#\s+", "# ");
+	}
+
+	foreach my $line (@{$lines}) {
+		if ($line->text =~ m"^(#?)SUBDIR\s*\+=(\s*)(\S+)\s*(?:#\s*(.*?)\s*|)$") {
+			my ($comment_flag, $indentation, $subdir, $comment) = ($1, $2, $3, $4);
+
+			if ($comment_flag eq "#" && (!defined($comment) || $comment eq "")) {
+				$line->log_warning("${subdir} commented out without giving a reason.");
+			}
+
+			if ($indentation ne "\t") {
+				$line->log_warning("Indentation should be a single tab character.");
+			}
+
+			if ($subdir =~ m"\$" || !-f "${current_dir}/${subdir}/Makefile") {
+				next;
+			}
+
+			if (!defined($prev_subdir) || $subdir gt $prev_subdir) {
+				# correctly ordered
+			} elsif ($subdir eq $prev_subdir) {
+				$line->log_error("${subdir} must only appear once.");
+			} elsif ($prev_subdir eq "x11" && $subdir eq "archivers") {
+				# ignore that one, since it is documented in the top-level Makefile
+			} else {
+				$line->log_warning("${subdir} should come before ${prev_subdir}.");
+			}
+
+			$prev_subdir = $subdir;
+
+			if ($comment_flag eq "") {
+				push(@subdirs, "${current_dir}/${subdir}");
+			}
+		}
+	}
+
+	checklines_mk($lines);
+
+	if ($opt_recursive) {
+		$ipc_checking_root_recursively = true;
+		push(@todo_items, @subdirs);
+	}
+}
+
+sub checkdir_category() {
+	my $fname = "${current_dir}/Makefile";
+	my ($lines, $lineno);
+
+	$opt_debug_trace and log_debug($fname, NO_LINES, "checkdir_category()");
+
+	if (!($lines = load_lines($fname, true))) {
+		log_error($fname, NO_LINE_NUMBER, "Cannot be read.");
+		return;
+	}
+	parselines_mk($lines);
+
+	$lineno = 0;
+
+	# The first line must contain the RCS Id
+	if ($lineno <= $#{$lines} && checkline_rcsid_regex($lines->[$lineno], qr"#\s+", "# ")) {
+		$lineno++;
+	}
+
+	# Then, arbitrary comments may follow
+	while ($lineno <= $#{$lines} && $lines->[$lineno]->text =~ m"^#") {
+		$lineno++;
+	}
+
+	# Then we need an empty line
+	expect_empty_line($lines, \$lineno);
+
+	# Then comes the COMMENT line
+	if ($lineno <= $#{$lines} && $lines->[$lineno]->text =~ m"^COMMENT=\t*(.*)") {
+		my ($comment) = ($1);
+
+		checkline_valid_characters_in_variable($lines->[$lineno], qr"[-\040'(),/0-9A-Za-z]");
+		$lineno++;
+	} else {
+		$lines->[$lineno]->log_error("COMMENT= line expected.");
+	}
+
+	# Then we need an empty line
+	expect_empty_line($lines, \$lineno);
+
+	# And now to the most complicated part of the category Makefiles,
+	# the (hopefully) sorted list of SUBDIRs. The first step is to
+	# collect the SUBDIRs in the Makefile and in the file system.
+
+	my (@f_subdirs, @m_subdirs);
+
+	@f_subdirs = sort(get_subdirs($current_dir));
+
+	my $prev_subdir = undef;
+	while ($lineno <= $#{$lines}) {
+		my $line = $lines->[$lineno];
+
+		if ($line->text =~ m"^(#?)SUBDIR\+=(\s*)(\S+)\s*(?:#\s*(.*?)\s*|)$") {
+			my ($comment_flag, $indentation, $subdir, $comment) = ($1, $2, $3, $4);
+
+			if ($comment_flag eq "#" && (!defined($comment) || $comment eq "")) {
+				$line->log_warning("${subdir} commented out without giving a reason.");
+			}
+
+			if ($indentation ne "\t") {
+				$line->log_warning("Indentation should be a single tab character.");
+			}
+
+			if (defined($prev_subdir) && $subdir eq $prev_subdir) {
+				$line->log_error("${subdir} must only appear once.");
+			} elsif (defined($prev_subdir) && $subdir lt $prev_subdir) {
+				$line->log_warning("${subdir} should come before ${prev_subdir}.");
+			} else {
+				# correctly ordered
+			}
+
+			push(@m_subdirs, [$subdir, $line, $comment_flag ? false : true]);
+			$prev_subdir = $subdir;
+			$lineno++;
+
+		} else {
+			if ($line->text ne "") {
+				$line->log_error("SUBDIR+= line or empty line expected.");
+			}
+			last;
+		}
+	}
+
+	# To prevent unnecessary warnings about subdirectories that are
+	# in one list, but not in the other, we generate the sets of
+	# subdirs of each list.
+	my (%f_check, %m_check);
+	foreach my $f (@f_subdirs) { $f_check{$f} = true; }
+	foreach my $m (@m_subdirs) { $m_check{$m->[0]} = true; }
+
+	my ($f_index, $f_atend, $f_neednext, $f_current) = (0, false, true, undef, undef);
+	my ($m_index, $m_atend, $m_neednext, $m_current) = (0, false, true, undef, undef);
+	my ($line, $m_recurse);
+	my (@subdirs);
+
+	while (!($m_atend && $f_atend)) {
+
+		if (!$m_atend && $m_neednext) {
+			$m_neednext = false;
+			if ($m_index > $#m_subdirs) {
+				$m_atend = true;
+				$line = $lines->[$lineno];
+				next;
+			} else {
+				$m_current = $m_subdirs[$m_index]->[0];
+				$line = $m_subdirs[$m_index]->[1];
+				$m_recurse = $m_subdirs[$m_index]->[2];
+				$m_index++;
+			}
+		}
+
+		if (!$f_atend && $f_neednext) {
+			$f_neednext = false;
+			if ($f_index > $#f_subdirs) {
+				$f_atend = true;
+				next;
+			} else {
+				$f_current = $f_subdirs[$f_index++];
+			}
+		}
+
+		if (!$f_atend && ($m_atend || $f_current lt $m_current)) {
+			if (!exists($m_check{$f_current})) {
+				$line->log_error("${f_current} exists in the file system, but not in the Makefile.");
+				$line->append_before("SUBDIR+=\t${f_current}");
+			}
+			$f_neednext = true;
+
+		} elsif (!$m_atend && ($f_atend || $m_current lt $f_current)) {
+			if (!exists($f_check{$m_current})) {
+				$line->log_error("${m_current} exists in the Makefile, but not in the file system.");
+				$line->delete();
+			}
+			$m_neednext = true;
+
+		} else { # $f_current eq $m_current
+			$f_neednext = true;
+			$m_neednext = true;
+			if ($m_recurse) {
+				push(@subdirs, "${current_dir}/${m_current}");
+			}
+		}
+	}
+
+	# the wip category Makefile may have its own targets for generating
+	# indexes and READMEs. Just skip them.
+	if ($is_wip) {
+		while ($lineno <= $#{$lines} - 2) {
+			$lineno++;
+		}
+	}
+
+	expect_empty_line($lines, \$lineno);
+
+	# And, last but not least, the .include line
+	my $final_line = ".include \"../mk/bsd.pkg.subdir.mk\"";
+	expect($lines, \$lineno, qr"\Q$final_line\E")
+	|| expect_text($lines, \$lineno, ".include \"../mk/misc/category.mk\"");
+
+	if ($lineno <= $#{$lines}) {
+		$lines->[$lineno]->log_error("The file should end here.");
+	}
+
+	checklines_mk($lines);
+
+	autofix($lines);
+
+	if ($opt_recursive) {
+		unshift(@todo_items, @subdirs);
+	}
+}
+
+sub checkdir_package() {
+	my ($lines, $have_distinfo, $have_patches);
+
+	# Initialize global variables
+	$pkgdir = undef;
+	$filesdir = "files";
+	$patchdir = "patches";
+	$distinfo_file = "distinfo";
+	$effective_pkgname = undef;
+	$effective_pkgbase = undef;
+	$effective_pkgversion = undef;
+	$effective_pkgname_line = undef;
+	$seen_bsd_prefs_mk = false;
+	$pkgctx_vardef = {%{get_userdefined_variables()}};
+	$pkgctx_varuse = {};
+	$pkgctx_bl3 = {};
+	$pkgctx_plist_subst_cond = {};
+	$pkgctx_included = {};
+	$seen_Makefile_common = false;
+
+	# we need to handle the Makefile first to get some variables
+	if (!load_package_Makefile("${current_dir}/Makefile", \$lines)) {
+		log_error("${current_dir}/Makefile", NO_LINE_NUMBER, "Cannot be read.");
+		goto cleanup;
+	}
+
+	my @files = glob("${current_dir}/*");
+	if ($pkgdir ne ".") {
+		push(@files, glob("${current_dir}/${pkgdir}/*"));
+	}
+	if ($opt_check_extra) {
+		push(@files, glob("${current_dir}/${filesdir}/*"));
+	}
+	push(@files, glob("${current_dir}/${patchdir}/*"));
+	if ($distinfo_file !~ m"^(?:\./)?distinfo$") {
+		push(@files, "${current_dir}/${distinfo_file}");
+	}
+	$have_distinfo = false;
+	$have_patches = false;
+
+	# Determine the used variables before checking any of the
+	# Makefile fragments.
+	foreach my $fname (@files) {
+		if (($fname =~ m"^((?:.*/)?Makefile\..*|.*\.mk)$")
+		&& (not $fname =~ m"patch-")
+		&& (not $fname =~ m"${pkgdir}/")
+		&& (not $fname =~ m"${filesdir}/")
+		&& (defined(my $lines = load_lines($fname, true)))) {
+			parselines_mk($lines);
+			determine_used_variables($lines);
+		}
+	}
+
+	foreach my $fname (@files) {
+		if ($fname eq "${current_dir}/Makefile") {
+			$opt_check_Makefile and checkfile_package_Makefile($fname, $lines);
+		} else {
+			checkfile($fname);
+		}
+		if ($fname =~ m"/patches/patch-*$") {
+			$have_patches = true;
+		} elsif ($fname =~ m"/distinfo$") {
+			$have_distinfo = true;
+		}
+	}
+
+	if ($opt_check_distinfo && $opt_check_patches) {
+		if ($have_patches && ! $have_distinfo) {
+			log_warning("${current_dir}/$distinfo_file", NO_LINE_NUMBER, "File not found. Please run '".conf_make." makepatchsum'.");
+		}
+	}
+
+	if (!is_emptydir("${current_dir}/scripts")) {
+		log_warning("${current_dir}/scripts", NO_LINE_NUMBER, "This directory and its contents are deprecated! Please call the script(s) explicitly from the corresponding target(s) in the pkg's Makefile.");
+	}
+
+cleanup:
+	# Clean up global variables.
+	$pkgdir = undef;
+	$filesdir = undef;
+	$patchdir = undef;
+	$distinfo_file = undef;
+	$effective_pkgname = undef;
+	$effective_pkgbase = undef;
+	$effective_pkgversion = undef;
+	$effective_pkgname_line = undef;
+	$seen_bsd_prefs_mk = undef;
+	$pkgctx_vardef = undef;
+	$pkgctx_varuse = undef;
+	$pkgctx_bl3 = undef;
+	$pkgctx_plist_subst_cond = undef;
+	$pkgctx_included = undef;
+	$seen_Makefile_common = undef;
+}
+
+#
+# Selecting the proper checking procedures for a directory entry.
+#
+
+sub checkitem($) {
+	my ($item) = @_;
+	my ($st, $is_dir, $is_reg);
+
+	if (!($st = lstat($item))) {
+		log_error($item, NO_LINE_NUMBER, "Does not exist.");
+		return;
+	}
+
+	$is_dir = S_ISDIR($st->mode);
+	$is_reg = S_ISREG($st->mode);
+	if (!$is_reg && !$is_dir) {
+		log_error($item, NO_LINE_NUMBER, "Must be a file or directory.");
+		return;
+	}
+
+	$current_dir = $is_dir ? $item : dirname($item);
+	my $abs_current_dir = Cwd::abs_path($current_dir);
+	$is_wip = !$opt_import && ($abs_current_dir =~ m"/wip(?:/|$)");
+	$is_internal = ($abs_current_dir =~ m"/mk(?:/|$)");
+
+	# Determine the root directory of pkgsrc. By only overwriting
+	# the global variable $cwd_pkgsrcdir when we are checking inside
+	# a pkgsrc tree, the user can specify a tree with the
+	# --pkgsrcdir option and then check files (but not directories)
+	# outside of any pkgsrc tree.
+	$cur_pkgsrcdir = undef;
+	$pkgpath = undef;
+	foreach my $d (".", "..", "../..", "../../..") {
+		if (-f "${current_dir}/${d}/mk/bsd.pkg.mk") {
+			$cur_pkgsrcdir = $d;
+			$pkgpath = relative_path("${current_dir}/${d}", $current_dir);
+		}
+	}
+	if (!defined($cwd_pkgsrcdir) && defined($cur_pkgsrcdir)) {
+		$cwd_pkgsrcdir = "${current_dir}/${cur_pkgsrcdir}";
+	}
+
+	if (!defined($cwd_pkgsrcdir)) {
+		log_error($item, NO_LINE_NUMBER, "Cannot determine the pkgsrc root directory.");
+		return;
+	}
+
+	check_pkglint_version();	# (needs $cwd_pkgsrcdir)
+
+	return if $is_dir && is_emptydir($item);
+
+	if ($is_dir) {
+		checkdir_CVS($item);
+	}
+
+	if ($is_reg) {
+		checkfile($item);
+
+	} elsif (!defined($cur_pkgsrcdir)) {
+		log_error($item, NO_LINES, "Cannot check directories outside a pkgsrc tree.");
+
+	} elsif ($cur_pkgsrcdir eq "../..") {
+		checkdir_package();
+
+	} elsif ($cur_pkgsrcdir eq "..") {
+		checkdir_category();
+
+	} elsif ($cur_pkgsrcdir eq ".") {
+		checkdir_root();
+
+	} else {
+		log_error($item, NO_LINE_NUMBER, "Don't know how to check this directory.");
+	}
+}
+
+#
+# The main program
+#
+
+sub main() {
+
+	local $| = true;
+	parse_command_line();
+
+	@todo_items = (@ARGV != 0) ? @ARGV : (".");
+	while (@todo_items != 0) {
+		checkitem(shift(@todo_items));
+	}
+
+	if ($ipc_checking_root_recursively) {
+		check_unused_licenses();
+	}
+
+	PkgLint::Logging::print_summary_and_exit($opt_quiet);
+}
+
+main() unless caller();
diff --git a/pkgtools/pkglint4/files/pkglint.t b/pkgtools/pkglint4/files/pkglint.t
new file mode 100644
index 00000000000..13c56e61323
--- /dev/null
+++ b/pkgtools/pkglint4/files/pkglint.t
@@ -0,0 +1,198 @@
+#! @PERL@
+# $NetBSD: pkglint.t,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+
+require 'pkglint.pl';			# so we can test its internals
+$pkglint::program = 'pkglint.pl';	# because it self-greps for vartypes
+
+use Test::More tests => 36;
+use Test::Deep;
+use Test::Trap;
+
+use Config;
+use File::Basename;
+use IO::File;
+use IPC::Open3;
+use Symbol qw(gensym);
+
+use warnings;
+use strict;
+
+sub test_unit {
+	my ($unit, $params, $exitcode, $stdout_re, $stderr_re) = @_;
+	$stdout_re ||= '^$';
+	$stderr_re ||= '^$';
+
+	my @results = trap { $unit->(@$params) };
+
+	if (defined $exitcode) {
+		is($trap->exit, $exitcode, qq{exits $exitcode});
+	} else {
+		is($trap->exit, undef, q{doesn't exit});
+	}
+	like($trap->stdout, qr/$stdout_re/sm, qq{stdout matches $stdout_re});
+	like($trap->stderr, qr/$stderr_re/sm, qq{stderr matches $stderr_re});
+
+	return @results;
+}
+
+sub test_program {
+	my ($command, $params, $exitcode, $stdout_re, $stderr_re) = @_;
+	$stdout_re ||= '^$';
+	$stderr_re ||= '^$';
+
+	my $stdout = '';
+	my $stderr = '';
+	local *CATCHERR = IO::File->new_tmpfile;
+	my $pid = open3(gensym(), \*CATCHOUT, ">&CATCHERR", $command, @$params);
+	while (my $l = <CATCHOUT>) {
+		$stdout .= $l;
+	}
+	waitpid($pid, 0);
+	my $ret = $? >> 8;
+	seek CATCHERR, 0, 0;
+	while (my $l = <CATCHERR>) {
+		$stderr .= $l;
+	}
+
+	if (defined $exitcode) {
+		is($ret, $exitcode, qq{exits $exitcode});
+	}
+	like($stdout, qr/$stdout_re/sm, qq{stdout matches $stdout_re});
+	like($stderr, qr/$stderr_re/sm, qq{stderr matches $stderr_re});
+
+	# return @results;
+}
+
+sub test_get_vartypes_basictypes {
+	my $unit = \&pkglint::get_vartypes_basictypes;
+
+	my @results = test_unit($unit);
+	my %types = %{$results[0]};
+
+	my @all_vartypes_basictypes = qw(
+		AwkCommand BrokenIn
+		BuildlinkDepmethod BuildlinkDepth BuildlinkPackages
+		CFlag Category Comment
+		Dependency DependencyWithPath
+		DistSuffix EmulPlatform
+		FetchURL FileMode Filemask Filename
+		Identifier Integer LdFlag License Mail_Address Message Option
+		Pathlist Pathmask Pathname
+		Perl5Packlist
+		PkgName PkgOptionsVar PkgPath PkgRevision
+		PlatformTriple PrefixPathname PythonDependency
+		RelativePkgDir RelativePkgPath
+		Restricted
+		SedCommand SedCommands
+		ShellCommand ShellWord
+		Stage String Tool URL Unchecked UserGroupName Varname Version
+		WrapperReorder WrapperTransform
+		WrkdirSubdirectory WrksrcSubdirectory
+		Yes YesNo YesNo_Indirectly
+	);
+
+	cmp_bag(
+		[ keys %types ],
+		\@all_vartypes_basictypes,
+		q{types contains all expected and no unexpected types},
+	);
+}
+
+sub test_get_vartypes_map {
+	my $unit = \&pkglint::get_vartypes_map;
+
+	my @results = test_unit($unit);
+	my %map = %{$results[0]};
+	is($map{'BSD_MAKE_ENV'}->basic_type(), 'ShellWord',
+	   q{a couple expected vars are typed right});
+	is($map{'USE_BUILTIN.*'}->basic_type(), 'YesNo_Indirectly',
+	   q{a couple expected vars are typed right});
+}
+
+sub test_checkline_mk_vartype_basic {
+	# this is what gets self-grepped: all that "elsif ($type eq"
+	# sub doesn't return anything, just warns or errors if need be
+	#
+	# TODO:
+	#
+	# test a shallow one and then a deeply nested one
+	# (type='Restricted', value='incorrect')
+	# (type='Restricted', value='RESTRICTED')
+	# (type='SedCommands', a few different values')
+	# once test coverage is persuasive, refactor to a dispatch table
+	# once refactored, get rid of the $pkglint::program global
+}
+
+sub test_pkglint_main {
+	my $unit = \&pkglint::main;
+
+	@ARGV = ('-h');
+	test_unit($unit, undef, 0, '^usage: pkglint ', '^$');
+
+	@ARGV = ('..');
+	test_unit($unit, undef, 0, '^looks fine', '^$');
+
+	@ARGV = ('.');
+	test_unit($unit, undef, 1, '^ERROR:.+how to check', '^$');
+
+	@ARGV = ();
+	test_unit($unit, undef, 1, '^ERROR:.+how to check', '^$');
+
+	@ARGV = ('/does/not/exist');
+	test_unit($unit, undef, 1, '^ERROR:.+not exist', '^$');
+
+	@ARGV = ($ENV{HOME});
+	test_unit($unit, undef, 1, '^ERROR:.+outside a pkgsrc', '^$');
+}
+
+sub test_lint_some_reference_packages {
+	my %reference_packages = (
+		'devel/syncdir' => {
+			stdout_re => <<EOT,
+^ERROR: .*Makefile: Each package must define its LICENSE\.
+ERROR: .*patches/patch-aa:[0-9]+: Comment expected\.
+2 errors and 0 warnings found\..*\$
+EOT
+			stderr_re => undef,
+			exitcode => 1,
+		},
+		'mail/qmail' => {
+			stdout_re => <<EOT,
+^WARN: .*Makefile:[0-9]+: USERGROUP_PHASE is defined but not used\. Spelling mistake\\?
+0 errors and 1 warnings found\..*\$
+EOT
+			stderr_re => undef,
+			exitcode => 0,
+		},
+		'mail/getmail' => {
+			stdout_re => <<EOT,
+^looks fine\.\$
+EOT
+			stderr_re => undef,
+			exitcode => 0,
+		},
+	);
+
+	my $dirprefix = dirname($0) || '.';
+	my $pkglint = "$dirprefix/pkglint.pl";
+	my $perl = $Config{perlpath};
+	for my $package (keys %reference_packages) {
+		test_program($perl, [ $pkglint, "@PKGSRCDIR@/$package" ],
+			$reference_packages{$package}->{exitcode},
+			$reference_packages{$package}->{stdout_re},
+			$reference_packages{$package}->{stderr_re});
+	}
+	# XXX this is JUST like test_unit(), when the tests work, refactor!
+
+}
+
+sub main {
+	test_get_vartypes_basictypes();
+	test_get_vartypes_map();
+	test_checkline_mk_vartype_basic();
+	test_pkglint_main();
+	test_lint_some_reference_packages();
+}
+
+main();
diff --git a/pkgtools/pkglint4/files/plist-clash.pl b/pkgtools/pkglint4/files/plist-clash.pl
new file mode 100644
index 00000000000..1b3f1c52465
--- /dev/null
+++ b/pkgtools/pkglint4/files/plist-clash.pl
@@ -0,0 +1,60 @@
+#! @PERL@
+# $NetBSD: plist-clash.pl,v 1.1 2015/11/25 16:42:21 rillig Exp $
+#
+# Scan all PLIST files given on the command line and report all lines
+# that appear more than once.
+
+my %files = ();
+
+sub read_PLIST($) {
+	my ($fname) = @_;
+
+	if (!open(F, "<", $fname)) {
+		warn "$!\n";
+		return undef;
+	}
+
+	my $lineno = 0;
+	foreach my $line (<F>) {
+		chomp($line);
+		$lineno++;
+
+		# Ignore comments and commands
+		next if ($line =~ qr"^@");
+
+		# Ignore filenames with embedded variables
+		next if ($line =~ qr"\$");
+		
+		if ($line =~ qr"^[A-Za-z0-9].*") {
+			if (!exists($files{$line})) {
+				$files{$line} = [];
+			}
+			push(@{$files{$line}}, "$fname:$lineno");
+
+		} else {
+			warn("ERROR: $fname:$lineno: Unknown line type\n");
+		}
+	}
+	close(F);
+}
+
+sub main() {
+	if (@ARGV == 0) {
+		die("usage: $0 <plist>...\n");
+	}
+
+	foreach my $plist (@ARGV) {
+		read_PLIST($plist);
+	}
+
+	foreach my $file (sort keys %files) {
+		my $srcs = $files{$file};
+		if (@{$srcs} != 1) {
+			foreach my $src (@{$srcs}) {
+				print "$src: $file\n";
+			}
+		}
+	}
+}
+
+main();