Linux build: Use sysroot when calculating dependencies

third_party/dpkg-dev/scripts/Dpkg/Source/Functions.pm

+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package Dpkg::Source::Functions;
+
+use strict;
+use warnings;
+
+our $VERSION = '0.01';
+
+use Exporter qw(import);
+our @EXPORT_OK = qw(erasedir fixperms fs_time is_binary);
+
+use Dpkg::ErrorHandling;
+use Dpkg::Gettext;
+use Dpkg::IPC;
+
+use POSIX qw(:errno_h);
+
+sub erasedir {
+    my ($dir) = @_;
+    if (not lstat($dir)) {
+        return if $! == ENOENT;
+        syserr(_g('cannot stat directory %s (before removal)'), $dir);
+    }
+    system 'rm','-rf','--',$dir;
+    subprocerr("rm -rf $dir") if $?;
+    if (not stat($dir)) {
+        return if $! == ENOENT;
+        syserr(_g("unable to check for removal of dir `%s'"), $dir);
+    }
+    error(_g("rm -rf failed to remove `%s'"), $dir);
+}
+
+sub fixperms {
+    my ($dir) = @_;
+    my ($mode, $modes_set);
+    # Unfortunately tar insists on applying our umask _to the original
+    # permissions_ rather than mostly-ignoring the original
+    # permissions.  We fix it up with chmod -R (which saves us some
+    # work) but we have to construct a u+/- string which is a bit
+    # of a palaver.  (Numeric doesn't work because we need [ugo]+X
+    # and [ugo]=<stuff> doesn't work because that unsets sgid on dirs.)
+    $mode = 0777 & ~umask;
+    for my $i (0 .. 2) {
+        $modes_set .= ',' if $i;
+        $modes_set .= qw(u g o)[$i];
+        for my $j (0 .. 2) {
+            $modes_set .= $mode & (0400 >> ($i * 3 + $j)) ? '+' : '-';
+            $modes_set .= qw(r w X)[$j];
+        }
+    }
+    system('chmod', '-R', '--', $modes_set, $dir);
+    subprocerr("chmod -R -- $modes_set $dir") if $?;
+}
+
+# Touch the file and read the resulting mtime.
+#
+# If the file doesn't exist, create it, read the mtime and unlink it.
+#
+# Use this instead of time() when the timestamp is going to be
+# used to set file timestamps. This avoids confusion when an
+# NFS server and NFS client disagree about what time it is.
+sub fs_time($) {
+    my ($file) = @_;
+    my $is_temp = 0;
+    if (not -e $file) {
+        open(my $temp_fh, '>', $file) or syserr(_g('cannot write %s'));
+        close($temp_fh);
+        $is_temp = 1;
+    } else {
+        utime(undef, undef, $file) or
+            syserr(_g('cannot change timestamp for %s'), $file);
+    }
+    stat($file) or syserr(_g('cannot read timestamp from %s'), $file);
+    my $mtime = (stat(_))[9];
+    unlink($file) if $is_temp;
+    return $mtime;
+}
+
+sub is_binary($) {
+    my ($file) = @_;
+
+    # TODO: might want to reimplement what diff does, aka checking if the
+    # file contains \0 in the first 4Kb of data
+
+    # Use diff to check if it's a binary file
+    my $diffgen;
+    my $diff_pid = spawn(
+        exec => [ 'diff', '-u', '--', '/dev/null', $file ],
+        env => { LC_ALL => 'C', LANG => 'C', TZ => 'UTC0' },
+        to_pipe => \$diffgen,
+    );
+    my $result = 0;
+    local $_;
+    while (<$diffgen>) {
+        if (m/^(?:binary|[^-+\@ ].*\bdiffer\b)/i) {
+            $result = 1;
+            last;
+        } elsif (m/^[-+\@ ]/) {
+            $result = 0;
+            last;
+        }
+    }
+    close($diffgen) or syserr('close on diff pipe');
+    wait_child($diff_pid, nocheck => 1, cmdline => "diff -u -- /dev/null $file");
+    return $result;
+}
+
+1;