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, $opt_f, $opt_m );
  14
  15 getopts('hpvcfm:');
  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 $commit = safe_pipe_capture('git-rev-parse', '--verify', "$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     $parent =  safe_pipe_capture('git-rev-parse', '--verify', "$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  = safe_pipe_capture('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 open(MSG, ">.msg") or die "Cannot open .msg for writing";
  81 print MSG $opt_m;
  82 close MSG;
  83
  84 `git-cat-file commit $commit | sed -e '1,/^\$/d' >> .msg`;
  85 $? && die "Error extracting the commit message";
  86
  87 my (@afiles, @dfiles, @mfiles);
  88 my @files = safe_pipe_capture('git-diff-tree', '-r', $parent, $commit);
  89 #print @files;
  90 $? && die "Error in git-diff-tree";
  91 foreach my $f (@files) {
  92     chomp $f;
  93     my @fields = split(m!\s+!, $f);
  94     if ($fields[4] eq 'A') {
  95         push @afiles, $fields[5];
  96     }
  97     if ($fields[4] eq 'M') {
  98         push @mfiles, $fields[5];
  99     }
 100     if ($fields[4] eq 'R') {
 101         push @dfiles, $fields[5];
 102     }
 103 }
 104 $opt_v && print "The commit affects:\n ";
 105 $opt_v && print join ("\n ", @afiles,@mfiles,@dfiles) . "\n\n";
 106 undef @files; # don't need it anymore
 107
 108 # check that the files are clean and up to date according to cvs
 109 my $dirty;
 110 foreach my $f (@afiles) {
 111     # This should return only one value
 112     my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
 113     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 114     unless ($status[0] =~ m/Status: Unknown$/) {
 115         $dirty = 1;
 116         warn "File $f is already known in your CVS checkout -- perhaps it has been added by another user. Or this may indicate that it exists on a different branch. If this is the case, use -f to force the merge.\n";
 117     }
 118 }
 119 foreach my $f (@mfiles, @dfiles) {
 120     # TODO:we need to handle removed in cvs
 121     my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
 122     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 123     unless ($status[0] =~ m/Status: Up-to-date$/) {
 124         $dirty = 1;
 125         warn "File $f not up to date in your CVS checkout!\n";
 126     }
 127 }
 128 if ($dirty) {
 129     if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 130         $dirty = 0;
 131     } else {
 132         die "Exiting: your CVS tree is not clean for this merge.";
 133     }
 134 }
 135
 136 ###
 137 ### NOTE: if you are planning to die() past this point
 138 ###       you MUST call cleanupcvs(@files) before die()
 139 ###
 140
 141
 142 print "'Patching' binary files\n";
 143
 144 my @bfiles = grep(m/^Binary/, safe_pipe_capture('git-diff-tree', '-p', $parent, $commit));
 145 @bfiles = map { chomp } @bfiles;
 146 foreach my $f (@bfiles) {
 147     # check that the file in cvs matches the "old" file
 148     # extract the file to $tmpdir and comparre with cmp
 149     my $tree = safe_pipe_capture('git-rev-parse', "$parent^{tree}");
 150     chomp $tree;
 151     my $blob = `git-ls-tree $tree "$f" | cut -f 1 | cut -d ' ' -f 3`;
 152     chomp $blob;
 153     `git-cat-file blob $blob > $tmpdir/blob`;
 154     if (system('cmp', '-q', $f, "$tmpdir/blob")) {
 155         warn "Binary file $f in CVS does not match parent.\n";
 156         $dirty = 1;
 157         next;
 158     }
 159
 160     # replace with the new file
 161      `git-cat-file blob $blob > $f`;
 162
 163     # TODO: something smart with file modes
 164
 165 }
 166 if ($dirty) {
 167     cleanupcvs(@files);
 168     die "Exiting: Binary files in CVS do not match parent";
 169 }
 170
 171 ## apply non-binary changes
 172 my $fuzz = $opt_p ? 0 : 2;
 173
 174 print "Patching non-binary files\n";
 175 print `(git-diff-tree -p $parent -p $commit | patch -p1 -F $fuzz ) 2>&1`;
 176
 177 my $dirtypatch = 0;
 178 if (($? >> 8) == 2) {
 179     cleanupcvs(@files);
 180     die "Exiting: Patch reported serious trouble -- you will have to apply this patch manually";
 181 } elsif (($? >> 8) == 1) { # some hunks failed to apply
 182     $dirtypatch = 1;
 183 }
 184
 185 foreach my $f (@afiles) {
 186     system('cvs', 'add', $f);
 187     if ($?) {
 188         $dirty = 1;
 189         warn "Failed to cvs add $f -- you may need to do it manually";
 190     }
 191 }
 192
 193 foreach my $f (@dfiles) {
 194     system('cvs', 'rm', '-f', $f);
 195     if ($?) {
 196         $dirty = 1;
 197         warn "Failed to cvs rm -f $f -- you may need to do it manually";
 198     }
 199 }
 200
 201 print "Commit to CVS\n";
 202 my $commitfiles = join(' ', @afiles, @mfiles, @dfiles);
 203 my $cmd = "cvs commit -F .msg $commitfiles";
 204
 205 if ($dirtypatch) {
 206     print "NOTE: One or more hunks failed to apply cleanly.\n";
 207     print "Resolve the conflicts and then commit using:\n";
 208     print "\n    $cmd\n\n";
 209     exit(1);
 210 }
 211
 212
 213 if ($opt_c) {
 214     print "Autocommit\n  $cmd\n";
 215     print safe_pipe_capture('cvs', 'commit', '-F', '.msg', @afiles, @mfiles, @dfiles);
 216     if ($?) {
 217         cleanupcvs(@files);
 218         die "Exiting: The commit did not succeed";
 219     }
 220     print "Committed successfully to CVS\n";
 221 } else {
 222     print "Ready for you to commit, just run:\n\n   $cmd\n";
 223 }
 224 sub usage {
 225         print STDERR <<END;
 226 Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
 227 END
 228         exit(1);
 229 }
 230
 231 # ensure cvs is clean before we die
 232 sub cleanupcvs {
 233     my @files = @_;
 234     foreach my $f (@files) {
 235         system('cvs', '-q', 'update', '-C', $f);
 236         if ($?) {
 237             warn "Warning! Failed to cleanup state of $f\n";
 238         }
 239     }
 240 }
 241
 242 # An alterative to `command` that allows input to be passed as an array
 243 # to work around shell problems with weird characters in arguments
 244 # if the exec returns non-zero we die
 245 sub safe_pipe_capture {
 246     my @output;
 247     if (my $pid = open my $child, '-|') {
 248         @output = (<$child>);
 249         close $child or die join(' ',@_).": $! $?";
 250     } else {
 251         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 252     }
 253     return wantarray ? @output : join('',@output);
 254 }