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