xref: /linux/scripts/setlocalversion (revision 2fc2991175bf77395e6b15fe6b2304d3bf72da40)
1#!/usr/bin/perl
2# Copyright 2004 - Ryan Anderson <ryan@michonline.com>  GPL v2
3
4use strict;
5use warnings;
6use Digest::MD5;
7require 5.006;
8
9if (@ARGV != 1) {
10	print <<EOT;
11Usage: setlocalversion <srctree>
12EOT
13	exit(1);
14}
15
16my ($srctree) = @ARGV;
17chdir($srctree);
18
19my @LOCALVERSIONS = ();
20
21# We are going to use the following commands to try and determine if this
22# repository is at a Version boundary (i.e, 2.6.10 vs 2.6.10 + some patches) We
23# currently assume that all meaningful version boundaries are marked by a tag.
24# We don't care what the tag is, just that something exists.
25
26# Git/Cogito store the top-of-tree "commit" in .git/HEAD
27# A list of known tags sits in .git/refs/tags/
28#
29# The simple trick here is to just compare the two of these, and if we get a
30# match, return nothing, otherwise, return a subset of the SHA-1 hash in
31# .git/HEAD
32
33sub do_git_checks {
34	open(H,"<.git/HEAD") or return;
35	my $head = <H>;
36	chomp $head;
37	close(H);
38
39	opendir(D,".git/refs/tags") or return;
40	foreach my $tagfile (grep !/^\.{1,2}$/, readdir(D)) {
41		open(F,"<.git/refs/tags/" . $tagfile) or return;
42		my $tag = <F>;
43		chomp $tag;
44		close(F);
45		return if ($tag eq $head);
46	}
47	closedir(D);
48
49	push @LOCALVERSIONS, "g" . substr($head,0,8);
50}
51
52if ( -d ".git") {
53	do_git_checks();
54}
55
56printf "-%s\n", join("-",@LOCALVERSIONS) if (scalar @LOCALVERSIONS > 0);
57