git-cvsexportcommit.perl

   1 #!/usr/bin/perl -w
   2
   3 # Known limitations:
   4 # - cannot add or remove binary files
   5 # - does not propagate permissions
   6 # - tells "ready for commit" even when things could not be completed
   7 #   (eg addition of a binary file)
   8
   9 use strict;
  10 use Getopt::Std;
  11 use File::Temp qw(tempdir);
  12 use Data::Dumper;
  13 use File::Basename qw(basename dirname);
  14
  15 unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
  16     die "GIT_DIR is not defined or is unreadable";
  17 }
  18
  19 our ($opt_h, $opt_p, $opt_v, $opt_c, $opt_f, $opt_m );
  20
  21 getopts('hpvcfm:');
  22
  23 $opt_h && usage();
  24
  25 die "Need at least one commit identifier!" unless @ARGV;
  26
  27 # setup a tempdir
  28 our ($tmpdir, $tmpdirname) = tempdir('git-cvsapplycommit-XXXXXX',
  29                                      TMPDIR => 1,
  30                                      CLEANUP => 1);
  31
  32 print Dumper(@ARGV);
  33 # resolve target commit
  34 my $commit;
  35 $commit = pop @ARGV;
  36 $commit = safe_pipe_capture('git-rev-parse', '--verify', "$commit^0");
  37 chomp $commit;
  38 if ($?) {
  39     die "The commit reference $commit did not resolve!";
  40 }
  41
  42 # resolve what parent we want
  43 my $parent;
  44 if (@ARGV) {
  45     $parent = pop @ARGV;
  46     $parent =  safe_pipe_capture('git-rev-parse', '--verify', "$parent^0");
  47     chomp $parent;
  48     if ($?) {
  49         die "The parent reference did not resolve!";
  50     }
  51 }
  52
  53 # find parents from the commit itself
  54 my @commit  = safe_pipe_capture('git-cat-file', 'commit', $commit);
  55 my @parents;
  56 foreach my $p (@commit) {
  57     if ($p =~ m/^$/) { # end of commit headers, we're done
  58         last;
  59     }
  60     if ($p =~ m/^parent (\w{40})$/) { # found a parent
  61         push @parents, $1;
  62     }
  63 }
  64
  65 if ($parent) {
  66     my $found;
  67     # double check that it's a valid parent
  68     foreach my $p (@parents) {
  69         if ($p eq $parent) {
  70             $found = 1;
  71             last;
  72         }; # found it
  73     }
  74     die "Did not find $parent in the parents for this commit!" if !$found;
  75 } else { # we don't have a parent from the cmdline...
  76     if (@parents == 1) { # it's safe to get it from the commit
  77         $parent = $parents[0];
  78     } else { # or perhaps not!
  79         die "This commit has more than one parent -- please name the parent you want to use explicitly";
  80     }
  81 }
  82
  83 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";
  84
  85 # grab the commit message
  86 open(MSG, ">.msg") or die "Cannot open .msg for writing";
  87 print MSG $opt_m;
  88 close MSG;
  89
  90 `git-cat-file commit $commit | sed -e '1,/^\$/d' >> .msg`;
  91 $? && die "Error extracting the commit message";
  92
  93 my (@afiles, @dfiles, @mfiles, @dirs);
  94 my @files = safe_pipe_capture('git-diff-tree', '-r', $parent, $commit);
  95 #print @files;
  96 $? && die "Error in git-diff-tree";
  97 foreach my $f (@files) {
  98     chomp $f;
  99     my @fields = split(m!\s+!, $f);
 100     if ($fields[4] eq 'A') {
 101         my $path = $fields[5];
 102         push @afiles, $path;
 103         # add any needed parent directories
 104         $path = dirname $path;
 105         while (!-d $path and ! grep { $_ eq $path } @dirs) {
 106             unshift @dirs, $path;
 107             $path = dirname $path;
 108         }
 109     }
 110     if ($fields[4] eq 'M') {
 111         push @mfiles, $fields[5];
 112     }
 113     if ($fields[4] eq 'R') {
 114         push @dfiles, $fields[5];
 115     }
 116 }
 117 $opt_v && print "The commit affects:\n ";
 118 $opt_v && print join ("\n ", @afiles,@mfiles,@dfiles) . "\n\n";
 119 undef @files; # don't need it anymore
 120
 121 # check that the files are clean and up to date according to cvs
 122 my $dirty;
 123 foreach my $d (@dirs) {
 124     if (-e $d) {
 125         $dirty = 1;
 126         warn "$d exists and is not a directory!\n";
 127     }
 128 }
 129 foreach my $f (@afiles) {
 130     # This should return only one value
 131     my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
 132     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 133     if (-d dirname $f and $status[0] !~ m/Status: Unknown$/
 134         and $status[0] !~ m/^File: no file /) {
 135         $dirty = 1;
 136         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";
 137         warn "Status was: $status[0]\n";
 138     }
 139 }
 140 foreach my $f (@mfiles, @dfiles) {
 141     # TODO:we need to handle removed in cvs
 142     my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
 143     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 144     unless ($status[0] =~ m/Status: Up-to-date$/) {
 145         $dirty = 1;
 146         warn "File $f not up to date in your CVS checkout!\n";
 147     }
 148 }
 149 if ($dirty) {
 150     if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 151         $dirty = 0;
 152     } else {
 153         die "Exiting: your CVS tree is not clean for this merge.";
 154     }
 155 }
 156
 157 ###
 158 ### NOTE: if you are planning to die() past this point
 159 ###       you MUST call cleanupcvs(@files) before die()
 160 ###
 161
 162
 163 print "Creating new directories\n";
 164 foreach my $d (@dirs) {
 165     unless (mkdir $d) {
 166         warn "Could not mkdir $d: $!";
 167         $dirty = 1;
 168     }
 169     `cvs add $d`;
 170     if ($?) {
 171         $dirty = 1;
 172         warn "Failed to cvs add directory $d -- you may need to do it manually";
 173     }
 174 }
 175
 176 print "'Patching' binary files\n";
 177
 178 my @bfiles = grep(m/^Binary/, safe_pipe_capture('git-diff-tree', '-p', $parent, $commit));
 179 @bfiles = map { chomp } @bfiles;
 180 foreach my $f (@bfiles) {
 181     # check that the file in cvs matches the "old" file
 182     # extract the file to $tmpdir and comparre with cmp
 183     my $tree = safe_pipe_capture('git-rev-parse', "$parent^{tree}");
 184     chomp $tree;
 185     my $blob = `git-ls-tree $tree "$f" | cut -f 1 | cut -d ' ' -f 3`;
 186     chomp $blob;
 187     `git-cat-file blob $blob > $tmpdir/blob`;
 188     if (system('cmp', '-s', $f, "$tmpdir/blob")) {
 189         warn "Binary file $f in CVS does not match parent.\n";
 190         $dirty = 1;
 191         next;
 192     }
 193
 194     # replace with the new file
 195      `git-cat-file blob $blob > $f`;
 196
 197     # TODO: something smart with file modes
 198
 199 }
 200 if ($dirty) {
 201     cleanupcvs(@files);
 202     die "Exiting: Binary files in CVS do not match parent";
 203 }
 204
 205 ## apply non-binary changes
 206 my $fuzz = $opt_p ? 0 : 2;
 207
 208 print "Patching non-binary files\n";
 209 print `(git-diff-tree -p $parent -p $commit | patch -p1 -F $fuzz ) 2>&1`;
 210
 211 my $dirtypatch = 0;
 212 if (($? >> 8) == 2) {
 213     cleanupcvs(@files);
 214     die "Exiting: Patch reported serious trouble -- you will have to apply this patch manually";
 215 } elsif (($? >> 8) == 1) { # some hunks failed to apply
 216     $dirtypatch = 1;
 217 }
 218
 219 foreach my $f (@afiles) {
 220     system('cvs', 'add', $f);
 221     if ($?) {
 222         $dirty = 1;
 223         warn "Failed to cvs add $f -- you may need to do it manually";
 224     }
 225 }
 226
 227 foreach my $f (@dfiles) {
 228     system('cvs', 'rm', '-f', $f);
 229     if ($?) {
 230         $dirty = 1;
 231         warn "Failed to cvs rm -f $f -- you may need to do it manually";
 232     }
 233 }
 234
 235 print "Commit to CVS\n";
 236 my $commitfiles = join(' ', @afiles, @mfiles, @dfiles);
 237 my $cmd = "cvs commit -F .msg $commitfiles";
 238
 239 if ($dirtypatch) {
 240     print "NOTE: One or more hunks failed to apply cleanly.\n";
 241     print "Resolve the conflicts and then commit using:\n";
 242     print "\n    $cmd\n\n";
 243     exit(1);
 244 }
 245
 246
 247 if ($opt_c) {
 248     print "Autocommit\n  $cmd\n";
 249     print safe_pipe_capture('cvs', 'commit', '-F', '.msg', @afiles, @mfiles, @dfiles);
 250     if ($?) {
 251         cleanupcvs(@files);
 252         die "Exiting: The commit did not succeed";
 253     }
 254     print "Committed successfully to CVS\n";
 255 } else {
 256     print "Ready for you to commit, just run:\n\n   $cmd\n";
 257 }
 258 sub usage {
 259         print STDERR <<END;
 260 Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
 261 END
 262         exit(1);
 263 }
 264
 265 # ensure cvs is clean before we die
 266 sub cleanupcvs {
 267     my @files = @_;
 268     foreach my $f (@files) {
 269         system('cvs', '-q', 'update', '-C', $f);
 270         if ($?) {
 271             warn "Warning! Failed to cleanup state of $f\n";
 272         }
 273     }
 274 }
 275
 276 # An alterative to `command` that allows input to be passed as an array
 277 # to work around shell problems with weird characters in arguments
 278 # if the exec returns non-zero we die
 279 sub safe_pipe_capture {
 280     my @output;
 281     if (my $pid = open my $child, '-|') {
 282         @output = (<$child>);
 283         close $child or die join(' ',@_).": $! $?";
 284     } else {
 285         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 286     }
 287     return wantarray ? @output : join('',@output);
 288 }