#!/usr/bin/perl

=encoding UTF-8

=head1 NAME

dh_testroot - ensure that a package is built with necessary level of root permissions

=head1 SYNOPSIS

B<dh_testroot> [S<I<debhelper options>>]

=head1 DESCRIPTION

B<dh_testroot> is used to determine if the package has access to at
least the level of root access that it declared it needed via the
Rules-Requires-Root (R³) field.

The following is how B<dh_testroot> behaves based on the effective
value of the R³ field:

=over 4

=item "binary-targets"

B<dh_testroot> asserts that it is run as root or under L<fakeroot(1)>.

=item "no"

B<dh_testroot> returns successfully.

=item Any other value than the above

B<dh_testroot> asserts that it is either run as root (or under
L<fakeroot(1)>) or the builder has provided the B<DEB_GAIN_ROOT_CMD>
environment variable (e.g. via dpkg-buildpackage -r).

=back

For backwards compatibility, B<dh_testroot> will consider the absence
of the R³ field as if the R³ field was set to "binary-targets".

=cut

use strict;
use warnings;
use Debian::Debhelper::Dh_Lib;

our $VERSION = DH_BUILTIN_VERSION;

inhibit_log();

my $requirements = Debian::Debhelper::Dh_Lib::root_requirements();

if (! -f 'debian/control') {
	warning('dh_testroot must be called from the source root');
}

# By declaration; nothing requires root and this command must be a no-op in that case.
exit 0 if $requirements eq 'none';
# The builder /can/ choose to ignore the requirements and just call us as root.
# If so, we do not bother checking the requirements any further.
exit 0 if $< == 0;
if ($requirements eq 'legacy-root') {
	error("You must run this as root (or use fakeroot).");
} else {
	my $env = $ENV{DEB_GAIN_ROOT_CMD};
	error("Package needs targeted root but builder has not provided a gain-root command via \${DEB_GAIN_ROOT_CMD}")
		if not $env;
}

=head1 SEE ALSO

L<debhelper(7)>

This program is a part of debhelper.

=head1 AUTHOR

Joey Hess <joeyh@debian.org>

=cut