Re: kernel versions on Linus bk tree

[Ryan Anderson <ryan@michonline.com>]

On Sat, Jan 08, 2005 at 01:23:20PM -0500, Jon Smirl wrote:
> One solution would be to bump the version in Linus bk to 2.6.11-rc1 on
> the first check in after 2.6.10 is cut. The general case of this would
> be to always bump the Linus bk version number immediately after
> cutting the released version.
> 
> I've been bitten by this ambiguity before when kernels from Linus BK
> have more code in them than the one from kernel.org and have the same
> version number. Changing the timing of the version bump would lessen
> this problem since kernels complied from Linus bk tend to have a short
> life.

I've got a patch in my local tree that tries to solve this through an
attempt to auto-append -bkXXXXXXXX (where each X is hex-digit of the md5
hash of the top-of-tree BK commit).

It doesn't solve the particular problem that caused you to send this
mail, but I think it solves the "modules from a -BK tree overwrite official releases"
problem that prompted me to code up this patch.

(Sam, Kai, I added you in case you have the time to look at this and
apply it or provide some feedback on my approach.  I have both a shell
script that depends on md5sum, and a Perl script in the patch.)

Signed-Off-By: Ryan Anderson <ryan@michonline.com>

diff -Nru a/Makefile b/Makefile
--- a/Makefile	2004-10-27 04:33:05 -04:00
+++ b/Makefile	2004-10-27 04:33:05 -04:00
@@ -513,6 +513,24 @@
 
 #export	INSTALL_PATH=/boot
 
+# If CONFIG_LOCALVERSION_AUTO is set, we automatically perform some tests
+# and try to determine if the current source tree is a release tree, of any sort,
+# or if is a pure development tree.
+# A 'release tree' is any tree with a BitKeeper TAG associated with it.
+# The primary goal of this is to make it safe for a native BitKeeper user to
+# build a release tree (i.e, 2.6.9) and also to continue developing against the
+# current Linus tree, without having the Linus tree overwrite the 2.6.9 tree 
+# when installed.
+#
+# (In the future, CVS and SVN support will be added as well.)
+
+ifeq ($(CONFIG_LOCALVERSION_AUTO),y)
+	ifeq ($(shell ls -d $(srctree)/BitKeeper 2>/dev/null),$(srctree)/BitKeeper)
+		localversion-bk := $(shell $(srctree)/scripts/setlocalversion.sh $(srctree) $(objtree))
+		LOCALVERSION := $(LOCALVERSION)$(localversion-bk)
+	endif
+endif
+
 #
 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
 # relocations required by build roots.  This is not defined in the
diff -Nru a/init/Kconfig b/init/Kconfig
--- a/init/Kconfig	2004-10-27 04:33:05 -04:00
+++ b/init/Kconfig	2004-10-27 04:33:05 -04:00
@@ -69,6 +69,18 @@
 	  object and source tree, in that order.  Your total string can
 	  be a maximum of 64 characters.
 
+config LOCALVERSION_AUTO
+	bool "Automatically append version information to the version string"
+	default y
+	help
+	  This will try to automatically determine if the current tree is a
+	  release tree by looking for BitKeeper tags that belong to the
+	  current top of tree revision.
+	  A string of the format -BKxxxxxxxx will be added to the
+	  localversion.  The string generated by this will be appended 
+	  after any matching localversion* files, but before the 
+	  value set in CONFIG_LOCALVERSION
+
 config SWAP
 	bool "Support for paging of anonymous memory (swap)"
 	depends on MMU
diff -Nru a/scripts/setlocalversion b/scripts/setlocalversion
--- /dev/null	Wed Dec 31 16:00:00 196900
+++ b/scripts/setlocalversion	2004-10-27 04:33:05 -04:00
@@ -0,0 +1,62 @@
+#!/usr/bin/perl
+# Copyright 2004 - Ryan Anderson <ryan@michonline.com>  GPL v2
+
+use strict;
+use warnings;
+use Digest::MD5;
+require 5.006;
+
+if (@ARGV != 2) {
+	print <<EOT;
+Usage: setlocalversion <srctree> <objtree>
+EOT
+	exit(1);
+}
+
+my $debug = 0;
+
+my ($srctree,$objtree) = @ARGV;
+
+my @LOCALVERSIONS = ();
+
+# BitKeeper Version Checks
+
+# We are going to use the following commands to try and determine if
+# this repository is at a Version boundary (i.e, 2.6.10 vs 2.6.10 + some patches)
+# We currently assume that all meaningful version boundaries are marked by a tag.
+# We don't care what the tag is, just that something exists.
+
+#ryan@mythryan2 ~/dev/linux/local$ T=`bk changes -r+ -k`
+#ryan@mythryan2 ~/dev/linux/local$ bk prs -h -d':TAG:\n' -r$T
+
+sub do_bk_checks {
+	chdir($srctree);
+	my $changeset = `bk changes -r+ -k`;
+	chomp $changeset;
+	my $tag = `bk prs -h -d':TAG:' -r'$changeset'`;
+
+	printf("ChangeSet Key = '%s'\nTAG = '%s'\n", $changeset, $tag) if ($debug > 0);
+
+	if (length($tag) == 0) {
+		# We do not have a tag at the Top of Tree, so we need to generate a localversion file
+		# We'll use the given $changeset as input into this.
+		my $localversion = Digest::MD5::md5_hex($changeset);
+		$localversion = substr($localversion,0,8);
+
+		printf("localversion = '%s'\n",$localversion) if ($debug > 0);
+
+		push @LOCALVERSIONS, "BK" . $localversion;
+
+	}
+}
+
+
+if ( -d "BitKeeper" ) {
+	my $bk = `which bk`;
+	chomp $bk;
+	if (length($bk) != 0) {
+		do_bk_checks();
+	}
+}
+
+printf "-%s\n", join("-",@LOCALVERSIONS) if (scalar @LOCALVERSIONS > 0);
diff -Nru a/scripts/setlocalversion.sh b/scripts/setlocalversion.sh
--- /dev/null	Wed Dec 31 16:00:00 196900
+++ b/scripts/setlocalversion.sh	2004-10-27 04:33:05 -04:00
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+BK=`which bk`
+
+srctree=$1
+objtree=$2
+
+if [ "$BK" == "" ];
+then
+	echo "scripts/setlocalversion.sh: Failed to find BK, not appending a -BK* version" >&2
+	exit 0
+fi
+
+cd $srctree
+changeset=`$BK changes -r+ -k`
+tag=`$BK prs -h -d':TAG:' -r'$changeset'`
+if [ "$tag" == "" ]; then
+	echo -n $changeset | md5sum | awk '{printf "-BK%s",substr($1,1,8)}'
+fi


-- 

Ryan Anderson
  sometimes Pug Majere