scripts: time.pl: avoid hard Time::HiRes dependency

Use Time::HiRes when available and fallback to raw syscall interface
when not. If that fails too, simply report 0, 0 as real time.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/scripts/time.pl b/scripts/time.pl
index cdc5824c83dc03084b5f5153dd8e684a06ed02bf..a23b57c89e3c8cd16960b5d3874f68a20c72b49c 100755 (executable)
--- a/scripts/time.pl
+++ b/scripts/time.pl
@@ -2,14 +2,37 @@
 
 use strict;
 use warnings;
-use Time::HiRes qw(gettimeofday);
+use Config;
 
 if (@ARGV < 2) {
        die "Usage: $0 <prefix> <command...>\n";
 }
 
+sub gettime {
+       my ($sec, $usec);
+
+       eval {
+               require Time::HiRes;
+               ($sec, $usec) = Time::HiRes::gettimeofday();
+       };
+
+       unless (defined($sec) && defined($usec)) {
+               my $tv_t = ($Config{'longsize'} == 8) ? 'qq' : 'll';
+               my $tv = pack $tv_t, 0, 0;
+
+               eval {
+                       require 'syscall.ph';
+                       syscall(SYS_gettimeofday(), $tv, 0);
+               };
+
+               ($sec, $usec) = unpack $tv_t, $tv;
+       }
+
+       return ($sec, $usec);
+}
+
 my ($prefix, @cmd) = @ARGV;
-my ($sec, $msec) = gettimeofday();
+my ($sec, $usec) = gettime();
 my $pid = fork();
 
 if (!defined($pid)) {
@@ -28,12 +51,12 @@ else {
        }
 
        my $exitcode = $? >> 8;
-       my ($sec2, $msec2) = gettimeofday();
+       my ($sec2, $usec2) = gettime();
        my (undef, undef, $cuser, $csystem) = times();
 
        printf STDERR "%s#%.2f#%.2f#%.2f\n",
                $prefix, $cuser, $csystem,
-               ($sec2 - $sec) + ($msec2 - $msec) / 1000000;
+               ($sec2 - $sec) + ($usec2 - $usec) / 1000000;
 
        $SIG{'INT'} = 'DEFAULT';
        $SIG{'QUIT'} = 'DEFAULT';