tools/git2svn.pl

   1 #!/usr/bin/perl
   2 #
   3 # This script pulls the current branch, then walks the first parents and
   4 # commit each of them into subversion.
   5 #
   6 # Copyright (C) 2008  Thomas Guyot-Sionnest <dermoth@aei.ca>
   7 #
   8 # The subversion repository must not be taking any external commit or this
   9 # script will erase them. This script cannot run off a bare repository.
  10 #
  11 # *** INITIAL SETUP ***
  12 #
  13 # 1. Run this command line to get the repository up and ready for this script:
  14 #
  15 # $ cd /path/to/repo/; git log -1 --pretty=format:%H >.git/git2svn.last_commit_hash
  16 #
  17 # 2. Configure the lines below... $ENV{'GIT_DIR'} must point to the .git
  18 #    directory of the git-svn repo.
  19 #
  20 # *** INITIAL SETUP ***
  21 #
  22 #  This program is free software: you can redistribute it and/or modify
  23 #  it under the terms of the GNU General Public License as published by
  24 #  the Free Software Foundation, either version 3 of the License, or
  25 #  (at your option) any later version.
  26 #
  27 #  This program is distributed in the hope that it will be useful,
  28 #  but WITHOUT ANY WARRANTY; without even the implied warranty of
  29 #  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  30 #  GNU General Public License for more details.
  31 #
  32 #  You should have received a copy of the GNU General Public License
  33 #  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  34
  35 use strict;
  36 use warnings;
  37
  38 # This is the git working tree. Must be tied to a SVN repository
  39 $ENV{'GIT_DIR'} = '/path/to/nagiosplug/.git';
  40
  41 # For some strange reasons this is needed:
  42 $ENV{'GIT_SVN_ID'} = 'trunk';
  43
  44 # Path to git binary
  45 my $git = '/usr/bin/git';
  46
  47 # Force commits from the hash stored in git2svn.last_commit_hash regardless
  48 # of the state of the current repository. Use this if the repository was
  49 # updated manually or if you need to set that hash to a specific value.
  50 # NB: Re-committing old hashes will revert then roll again changes to SVN.
  51 my $FORCE = 0;
  52
  53 # Print debug output. Useful if you want to see what's being committed.
  54 my $DEBUG = 0;
  55
  56 for (@ARGV) {
  57         $FORCE = 1 if (m/force/);
  58         $DEBUG = 1 if (m/debug/);
  59         if (m/help/ || m/--help/ || m/-h/) {
  60                 print "Usage: $0 [ debug ] [ force ] [ help ]\n";
  61                 exit 0;
  62         }
  63 }
  64
  65 # 1st get the current commit hash - we'll start committing to SVN from this one
  66 print "Reading saved hash from $ENV{'GIT_DIR'}/git2svn.last_commit_hash\n" if ($DEBUG);
  67 open(SAVHASH, "<$ENV{'GIT_DIR'}/git2svn.last_commit_hash")
  68         or die("Can't open $ENV{'GIT_DIR'}/git2svn.last_commit_hash: $!");
  69 my $saved_commit_hash = <SAVHASH>;
  70 chomp $saved_commit_hash;
  71 print "Saved commit hash: $saved_commit_hash\n" if ($DEBUG);
  72 close(SAVHASH);
  73
  74 my $last_commit_hash;
  75 if ($FORCE) {
  76         $last_commit_hash = $saved_commit_hash;
  77         print "Forcing last commit hash to $last_commit_hash\n" if ($DEBUG);
  78 } else {
  79         print "Running: $git log -1 --pretty=format:%H\n" if ($DEBUG);
  80         $last_commit_hash = `$git log -1 --pretty=format:%H`;
  81         die("Failed to retrieve last commit hash") if ($?);
  82         chomp $last_commit_hash;
  83         print "Last commit hash:  $last_commit_hash\n" if ($DEBUG);
  84
  85         # Sanity check
  86         die("Last commit hash and saved commit hash don't match, aborting")
  87                 if ($last_commit_hash ne $saved_commit_hash);
  88 }
  89
  90 # 2nd pull the remote tree
  91 print "Running: $git pull\n" if ($DEBUG);
  92 `$git pull`;
  93 die("Failed to pull") if ($?);
  94
  95 # Then list all first parents since the last one and insert them into an array
  96 my @commits;
  97 print "Running: $git rev-list --first-parent $last_commit_hash..HEAD\n" if ($DEBUG);
  98 open(REVLIST, "$git rev-list --first-parent $last_commit_hash..HEAD|")
  99         or die("Failed to retrieve revision list: $!");
 100
 101 while (<REVLIST>) {
 102         chomp;
 103         unshift @commits, $_;
 104         print "Prepending the list with $_\n" if ($DEBUG);
 105 }
 106
 107 close(REVLIST);
 108
 109 if (@commits == 0) {
 110         print "Nothing to do.\n";
 111         exit 0;
 112 }
 113
 114 # Finally, commit every revision found into SVN
 115 foreach my $commit (@commits) {
 116         print "Commiting $commit to Subversion\n";
 117         print "Running: $git svn set-tree --add-author-from $commit\n"  if ($DEBUG);
 118         `$git svn set-tree --add-author-from $commit`;
 119         die("Failed to commit hash $commit") if ($?);
 120 }
 121
 122 # Once done, update the last commit hash
 123 $last_commit_hash = pop @commits;
 124 print "Writing last commit hash to $ENV{'GIT_DIR'}/git2svn.last_commit_hash\n" if ($DEBUG);
 125 open(SAVHASH, ">$ENV{'GIT_DIR'}/git2svn.last_commit_hash")
 126         or die("Can't open $ENV{'GIT_DIR'}/git2svn.last_commit_hash for writing: $!");
 127 print SAVHASH $last_commit_hash;
 128 close(SAVHASH);
 129