git-cvsexportcommit.perl

   1 #!/usr/bin/perl -w
   2
   3 # Known limitations:
   4 # - does not propagate permissions
   5 # - tells "ready for commit" even when things could not be completed
   6 #   (not sure this is true anymore, more testing is needed)
   7 # - does not handle whitespace in pathnames at all.
   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_a, $opt_m );
  20
  21 getopts('hpvcfam:');
  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 # resolve target commit
  33 my $commit;
  34 $commit = pop @ARGV;
  35 $commit = safe_pipe_capture('git-rev-parse', '--verify', "$commit^0");
  36 chomp $commit;
  37 if ($?) {
  38     die "The commit reference $commit did not resolve!";
  39 }
  40
  41 # resolve what parent we want
  42 my $parent;
  43 if (@ARGV) {
  44     $parent = pop @ARGV;
  45     $parent =  safe_pipe_capture('git-rev-parse', '--verify', "$parent^0");
  46     chomp $parent;
  47     if ($?) {
  48         die "The parent reference did not resolve!";
  49     }
  50 }
  51
  52 # find parents from the commit itself
  53 my @commit  = safe_pipe_capture('git-cat-file', 'commit', $commit);
  54 my @parents;
  55 my $committer;
  56 my $author;
  57 my $stage = 'headers'; # headers, msg
  58 my $title;
  59 my $msg = '';
  60
  61 foreach my $line (@commit) {
  62     chomp $line;
  63     if ($stage eq 'headers' && $line eq '') {
  64         $stage = 'msg';
  65         next;
  66     }
  67
  68     if ($stage eq 'headers') {
  69         if ($line =~ m/^parent (\w{40})$/) { # found a parent
  70             push @parents, $1;
  71         } elsif ($line =~ m/^author (.+) \d+ [-+]\d+$/) {
  72             $author = $1;
  73         } elsif ($line =~ m/^committer (.+) \d+ [-+]\d+$/) {
  74             $committer = $1;
  75         }
  76     } else {
  77         $msg .= $line . "\n";
  78         unless ($title) {
  79             $title = $line;
  80         }
  81     }
  82 }
  83
  84 if ($parent) {
  85     my $found;
  86     # double check that it's a valid parent
  87     foreach my $p (@parents) {
  88         if ($p eq $parent) {
  89             $found = 1;
  90             last;
  91         }; # found it
  92     }
  93     die "Did not find $parent in the parents for this commit!" if !$found;
  94 } else { # we don't have a parent from the cmdline...
  95     if (@parents == 1) { # it's safe to get it from the commit
  96         $parent = $parents[0];
  97     } else { # or perhaps not!
  98         die "This commit has more than one parent -- please name the parent you want to use explicitly";
  99     }
 100 }
 101
 102 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";
 103
 104 # grab the commit message
 105 open(MSG, ">.msg") or die "Cannot open .msg for writing";
 106 if ($opt_m) {
 107     print MSG $opt_m;
 108 }
 109 print MSG $msg;
 110 if ($opt_a) {
 111     print MSG "\n\nAuthor: $author\n";
 112     if ($author ne $committer) {
 113         print MSG "Committer: $committer\n";
 114     }
 115 }
 116 close MSG;
 117
 118 my (@afiles, @dfiles, @mfiles, @dirs);
 119 my %amodes;
 120 my @files = safe_pipe_capture('git-diff-tree', '-r', $parent, $commit);
 121 #print @files;
 122 $? && die "Error in git-diff-tree";
 123 foreach my $f (@files) {
 124     chomp $f;
 125     my @fields = split(m!\s+!, $f);
 126     if ($fields[4] eq 'A') {
 127         my $path = $fields[5];
 128         $amodes{$path} = $fields[1];
 129         push @afiles, $path;
 130         # add any needed parent directories
 131         $path = dirname $path;
 132         while (!-d $path and ! grep { $_ eq $path } @dirs) {
 133             unshift @dirs, $path;
 134             $path = dirname $path;
 135         }
 136     }
 137     if ($fields[4] eq 'M') {
 138         push @mfiles, $fields[5];
 139     }
 140     if ($fields[4] eq 'D') {
 141         push @dfiles, $fields[5];
 142     }
 143 }
 144 my (@binfiles, @abfiles, @dbfiles, @bfiles, @mbfiles);
 145 @binfiles = grep m/^Binary files/, safe_pipe_capture('git-diff-tree', '-p', $parent, $commit);
 146 map { chomp } @binfiles;
 147 @abfiles = grep s/^Binary files \/dev\/null and b\/(.*) differ$/$1/, @binfiles;
 148 @dbfiles = grep s/^Binary files a\/(.*) and \/dev\/null differ$/$1/, @binfiles;
 149 @mbfiles = grep s/^Binary files a\/(.*) and b\/(.*) differ$/$1/, @binfiles;
 150 push @bfiles, @abfiles;
 151 push @bfiles, @dbfiles;
 152 push @bfiles, @mbfiles;
 153 push @mfiles, @mbfiles;
 154
 155 $opt_v && print "The commit affects:\n ";
 156 $opt_v && print join ("\n ", @afiles,@mfiles,@dfiles) . "\n\n";
 157 undef @files; # don't need it anymore
 158
 159 # check that the files are clean and up to date according to cvs
 160 my $dirty;
 161 foreach my $d (@dirs) {
 162     if (-e $d) {
 163         $dirty = 1;
 164         warn "$d exists and is not a directory!\n";
 165     }
 166 }
 167 foreach my $f (@afiles) {
 168     # This should return only one value
 169     if ($f =~ m,(.*)/[^/]*$,) {
 170         my $p = $1;
 171         next if (grep { $_ eq $p } @dirs);
 172     }
 173     my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
 174     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 175     if (-d dirname $f and $status[0] !~ m/Status: Unknown$/
 176         and $status[0] !~ m/^File: no file /) {
 177         $dirty = 1;
 178         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";
 179         warn "Status was: $status[0]\n";
 180     }
 181 }
 182
 183 foreach my $f (@mfiles, @dfiles) {
 184     # TODO:we need to handle removed in cvs
 185     my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
 186     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 187     unless ($status[0] =~ m/Status: Up-to-date$/) {
 188         $dirty = 1;
 189         warn "File $f not up to date in your CVS checkout!\n";
 190     }
 191 }
 192 if ($dirty) {
 193     if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 194         $dirty = 0;
 195     } else {
 196         die "Exiting: your CVS tree is not clean for this merge.";
 197     }
 198 }
 199
 200 ###
 201 ### NOTE: if you are planning to die() past this point
 202 ###       you MUST call cleanupcvs(@files) before die()
 203 ###
 204
 205
 206 print "Creating new directories\n";
 207 foreach my $d (@dirs) {
 208     unless (mkdir $d) {
 209         warn "Could not mkdir $d: $!";
 210         $dirty = 1;
 211     }
 212     `cvs add $d`;
 213     if ($?) {
 214         $dirty = 1;
 215         warn "Failed to cvs add directory $d -- you may need to do it manually";
 216     }
 217 }
 218
 219 print "'Patching' binary files\n";
 220
 221 foreach my $f (@bfiles) {
 222     # check that the file in cvs matches the "old" file
 223     # extract the file to $tmpdir and compare with cmp
 224     if (not(grep { $_ eq $f } @afiles)) {
 225         my $tree = safe_pipe_capture('git-rev-parse', "$parent^{tree}");
 226         chomp $tree;
 227         my $blob = `git-ls-tree $tree "$f" | cut -f 1 | cut -d ' ' -f 3`;
 228         chomp $blob;
 229         `git-cat-file blob $blob > $tmpdir/blob`;
 230         if (system('cmp', '-s', $f, "$tmpdir/blob")) {
 231             warn "Binary file $f in CVS does not match parent.\n";
 232             if (not $opt_f) {
 233                 $dirty = 1;
 234                 next;
 235             }
 236         }
 237     }
 238     if (not(grep { $_ eq $f } @dfiles)) {
 239         my $tree = safe_pipe_capture('git-rev-parse', "$commit^{tree}");
 240         chomp $tree;
 241         my $blob = `git-ls-tree $tree "$f" | cut -f 1 | cut -d ' ' -f 3`;
 242         chomp $blob;
 243         # replace with the new file
 244         `git-cat-file blob $blob > $f`;
 245     }
 246
 247     # TODO: something smart with file modes
 248
 249 }
 250 if ($dirty) {
 251     cleanupcvs(@files);
 252     die "Exiting: Binary files in CVS do not match parent";
 253 }
 254
 255 ## apply non-binary changes
 256 my $fuzz = $opt_p ? 0 : 2;
 257
 258 print "Patching non-binary files\n";
 259
 260 if (scalar(@afiles)+scalar(@dfiles)+scalar(@mfiles) != scalar(@bfiles)) {
 261     print `(git-diff-tree -p $parent -p $commit | patch -p1 -F $fuzz ) 2>&1`;
 262 }
 263
 264 my $dirtypatch = 0;
 265 if (($? >> 8) == 2) {
 266     cleanupcvs(@files);
 267     die "Exiting: Patch reported serious trouble -- you will have to apply this patch manually";
 268 } elsif (($? >> 8) == 1) { # some hunks failed to apply
 269     $dirtypatch = 1;
 270 }
 271
 272 foreach my $f (@afiles) {
 273     set_new_file_permissions($f, $amodes{$f});
 274     if (grep { $_ eq $f } @bfiles) {
 275       system('cvs', 'add','-kb',$f);
 276     } else {
 277       system('cvs', 'add', $f);
 278     }
 279     if ($?) {
 280         $dirty = 1;
 281         warn "Failed to cvs add $f -- you may need to do it manually";
 282     }
 283 }
 284
 285 foreach my $f (@dfiles) {
 286     system('cvs', 'rm', '-f', $f);
 287     if ($?) {
 288         $dirty = 1;
 289         warn "Failed to cvs rm -f $f -- you may need to do it manually";
 290     }
 291 }
 292
 293 print "Commit to CVS\n";
 294 print "Patch: $title\n";
 295 my $commitfiles = join(' ', @afiles, @mfiles, @dfiles);
 296 my $cmd = "cvs commit -F .msg $commitfiles";
 297
 298 if ($dirtypatch) {
 299     print "NOTE: One or more hunks failed to apply cleanly.\n";
 300     print "Resolve the conflicts and then commit using:\n";
 301     print "\n    $cmd\n\n";
 302     exit(1);
 303 }
 304
 305
 306 if ($opt_c) {
 307     print "Autocommit\n  $cmd\n";
 308     print safe_pipe_capture('cvs', 'commit', '-F', '.msg', @afiles, @mfiles, @dfiles);
 309     if ($?) {
 310         cleanupcvs(@files);
 311         die "Exiting: The commit did not succeed";
 312     }
 313     print "Committed successfully to CVS\n";
 314 } else {
 315     print "Ready for you to commit, just run:\n\n   $cmd\n";
 316 }
 317 sub usage {
 318         print STDERR <<END;
 319 Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
 320 END
 321         exit(1);
 322 }
 323
 324 # ensure cvs is clean before we die
 325 sub cleanupcvs {
 326     my @files = @_;
 327     foreach my $f (@files) {
 328         system('cvs', '-q', 'update', '-C', $f);
 329         if ($?) {
 330             warn "Warning! Failed to cleanup state of $f\n";
 331         }
 332     }
 333 }
 334
 335 # An alternative to `command` that allows input to be passed as an array
 336 # to work around shell problems with weird characters in arguments
 337 # if the exec returns non-zero we die
 338 sub safe_pipe_capture {
 339     my @output;
 340     if (my $pid = open my $child, '-|') {
 341         @output = (<$child>);
 342         close $child or die join(' ',@_).": $! $?";
 343     } else {
 344         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 345     }
 346     return wantarray ? @output : join('',@output);
 347 }
 348
 349 # For any file we want to add to cvs, we must first set its permissions
 350 # properly, *before* the "cvs add ..." command.  Otherwise, it is impossible
 351 # to change the permission of the file in the CVS repository using only cvs
 352 # commands.  This should be fixed in cvs-1.12.14.
 353 sub set_new_file_permissions {
 354     my ($file, $perm) = @_;
 355     chmod oct($perm), $file
 356       or die "failed to set permissions of \"$file\": $!\n";
 357 }