git-cvsexportcommit.perl

   1 #!/usr/bin/perl -w
   2
   3 use strict;
   4 use Getopt::Std;
   5 use File::Temp qw(tempdir);
   6 use Data::Dumper;
   7 use File::Basename qw(basename);
   8
   9 unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
  10     die "GIT_DIR is not defined or is unreadable";
  11 }
  12
  13 our ($opt_h, $opt_p, $opt_v, $opt_c );
  14
  15 getopts('hpvc');
  16
  17 $opt_h && usage();
  18
  19 die "Need at least one commit identifier!" unless @ARGV;
  20
  21 # setup a tempdir
  22 our ($tmpdir, $tmpdirname) = tempdir('git-cvsapplycommit-XXXXXX',
  23                                      TMPDIR => 1,
  24                                      CLEANUP => 1);
  25
  26 print Dumper(@ARGV);
  27 # resolve target commit
  28 my $commit;
  29 $commit = pop @ARGV;
  30 $commit = `git-rev-parse --verify "$commit"^0`;
  31 chomp $commit;
  32 if ($?) {
  33     die "The commit reference $commit did not resolve!";
  34 }
  35
  36 # resolve what parent we want
  37 my $parent;
  38 if (@ARGV) {
  39     $parent = pop @ARGV;
  40     $parent =  `git-rev-parse --verify "$parent"^0"`;
  41     chomp $parent;
  42     if ($?) {
  43         die "The parent reference did not resolve!";
  44     }
  45 }
  46
  47 # find parents from the commit itself
  48 my @commit  = `git-cat-file commit $commit`;
  49 my @parents;
  50 foreach my $p (@commit) {
  51     if ($p =~ m/^$/) { # end of commit headers, we're done
  52         last;
  53     }
  54     if ($p =~ m/^parent (\w{40})$/) { # found a parent
  55         push @parents, $1;
  56     }
  57 }
  58
  59 if ($parent) {
  60     # double check that it's a valid parent
  61     foreach my $p (@parents) {
  62         my $found;
  63         if ($p eq $parent) {
  64             $found = 1;
  65             last;
  66         }; # found it
  67         die "Did not find $parent in the parents for this commit!";
  68     }
  69 } else { # we don't have a parent from the cmdline...
  70     if (@parents == 1) { # it's safe to get it from the commit
  71         $parent = $parents[0];
  72     } else { # or perhaps not!
  73         die "This commit has more than one parent -- please name the parent you want to use explicitly";
  74     }
  75 }
  76
  77 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";
  78
  79 # grab the commit message
  80 `git-cat-file commit $commit | sed -e '1,/^\$/d' > .msg`;
  81 $? && die "Error extracting the commit message";
  82
  83 my (@afiles, @dfiles, @mfiles);
  84 my @files = `git-diff-tree -r $parent $commit`;
  85 print @files;
  86 $? && die "Error in git-diff-tree";
  87 foreach my $f (@files) {
  88     chomp $f;
  89     my @fields = split(m/\s+/, $f);
  90     if ($fields[4] eq 'A') {
  91         push @afiles, $fields[5];
  92     }
  93     if ($fields[4] eq 'M') {
  94         push @mfiles, $fields[5];
  95     }
  96     if ($fields[4] eq 'R') {
  97         push @dfiles, $fields[5];
  98     }
  99 }
 100 $opt_v && print "The commit affects:\n ";
 101 $opt_v && print join ("\n ", @afiles,@mfiles,@dfiles) . "\n\n";
 102 undef @files; # don't need it anymore
 103
 104 # check that the files are clean and up to date according to cvs
 105 my $dirty;
 106 foreach my $f (@afiles, @mfiles, @dfiles) {
 107     # TODO:we need to handle removed in cvs and/or new (from git)
 108     my $status = `cvs -q status "$f" | grep '^File: '`;
 109
 110     unless ($status =~ m/Status: Up-to-date$/) {
 111         $dirty = 1;
 112         warn "File $f not up to date in your CVS checkout!\n";
 113     }
 114 }
 115 if ($dirty) {
 116     die "Exiting: your CVS tree is not clean for this merge.";
 117 }
 118
 119 ###
 120 ### NOTE: if you are planning to die() past this point
 121 ###       you MUST call cleanupcvs(@files) before die()
 122 ###
 123
 124
 125 print "'Patching' binary files\n";
 126
 127 my @bfiles = `git-diff-tree -p $parent $commit | grep '^Binary'`;
 128 @bfiles = map { chomp } @bfiles;
 129 foreach my $f (@bfiles) {
 130     # check that the file in cvs matches the "old" file
 131     # extract the file to $tmpdir and comparre with cmp
 132     my $tree = `git-rev-parse $parent^{tree} `;
 133     chomp $tree;
 134     my $blob = `git-ls-tree $tree "$f" | cut -f 1 | cut -d ' ' -f 3`;
 135     chomp $blob;
 136     `git-cat-file blob $blob > $tmpdir/blob`;
 137     `cmp -q $f $tmpdir/blob`;
 138     if ($?) {
 139         warn "Binary file $f in CVS does not match parent.\n";
 140         $dirty = 1;
 141         next;
 142     }
 143
 144     # replace with the new file
 145      `git-cat-file blob $blob > $f`;
 146
 147     # TODO: something smart with file modes
 148
 149 }
 150 if ($dirty) {
 151     cleanupcvs(@files);
 152     die "Exiting: Binary files in CVS do not match parent";
 153 }
 154
 155 ## apply non-binary changes
 156 my $fuzz = $opt_p ? 0 : 2;
 157
 158 print "Patching non-binary files\n";
 159 print `(git-diff-tree -p $parent -p $commit | patch -p1 -F $fuzz ) 2>&1`;
 160
 161 my $dirtypatch = 0;
 162 if (($? >> 8) == 2) {
 163     cleanupcvs(@files);
 164     die "Exiting: Patch reported serious trouble -- you will have to apply this patch manually";
 165 } elsif (($? >> 8) == 1) { # some hunks failed to apply
 166     $dirtypatch = 1;
 167 }
 168
 169 foreach my $f (@afiles) {
 170     `cvs add $f`;
 171     if ($?) {
 172         $dirty = 1;
 173         warn "Failed to cvs add $f -- you may need to do it manually";
 174     }
 175 }
 176
 177 foreach my $f (@dfiles) {
 178     `cvs rm -f $f`;
 179     if ($?) {
 180         $dirty = 1;
 181         warn "Failed to cvs rm -f $f -- you may need to do it manually";
 182     }
 183 }
 184
 185 print "Commit to CVS\n";
 186 my $commitfiles = join(' ', @afiles, @mfiles, @dfiles);
 187 my $cmd = "cvs commit -F .msg $commitfiles";
 188
 189 if ($dirtypatch) {
 190     print "NOTE: One or more hunks failed to apply cleanly.\n";
 191     print "Resolve the conflicts and then commit using:\n";
 192     print "\n    $cmd\n\n";
 193     exit(1);
 194 }
 195
 196
 197 if ($opt_c) {
 198     print "Autocommit\n  $cmd\n";
 199     print `cvs commit -F .msg $commitfiles 2>&1`;
 200     if ($?) {
 201         cleanupcvs(@files);
 202         die "Exiting: The commit did not succeed";
 203     }
 204     print "Committed successfully to CVS\n";
 205 } else {
 206     print "Ready for you to commit, just run:\n\n   $cmd\n";
 207 }
 208 sub usage {
 209         print STDERR <<END;
 210 Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [ parent ] commit
 211 END
 212         exit(1);
 213 }
 214
 215 # ensure cvs is clean before we die
 216 sub cleanupcvs {
 217     my @files = @_;
 218     foreach my $f (@files) {
 219         `cvs -q update -C "$f"`;
 220         if ($?) {
 221             warn "Warning! Failed to cleanup state of $f\n";
 222         }
 223     }
 224 }
 225