git-cvsexportcommit.perl

   1 #!/usr/bin/perl -w
   2
   3 # Known limitations:
   4 # - does not propagate permissions
   5 # - error handling has not been extensively tested
   6 #
   7
   8 use strict;
   9 use Getopt::Std;
  10 use File::Temp qw(tempdir);
  11 use Data::Dumper;
  12 use File::Basename qw(basename dirname);
  13
  14 unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
  15     die "GIT_DIR is not defined or is unreadable";
  16 }
  17
  18 our ($opt_h, $opt_P, $opt_p, $opt_v, $opt_c, $opt_f, $opt_a, $opt_m, $opt_d);
  19
  20 getopts('hPpvcfam:d:');
  21
  22 $opt_h && usage();
  23
  24 die "Need at least one commit identifier!" unless @ARGV;
  25
  26 my @cvs;
  27 if ($opt_d) {
  28         @cvs = ('cvs', '-d', $opt_d);
  29 } else {
  30         @cvs = ('cvs');
  31 }
  32
  33 # setup a tempdir
  34 our ($tmpdir, $tmpdirname) = tempdir('git-cvsapplycommit-XXXXXX',
  35                                      TMPDIR => 1,
  36                                      CLEANUP => 1);
  37
  38 # resolve target commit
  39 my $commit;
  40 $commit = pop @ARGV;
  41 $commit = safe_pipe_capture('git-rev-parse', '--verify', "$commit^0");
  42 chomp $commit;
  43 if ($?) {
  44     die "The commit reference $commit did not resolve!";
  45 }
  46
  47 # resolve what parent we want
  48 my $parent;
  49 if (@ARGV) {
  50     $parent = pop @ARGV;
  51     $parent =  safe_pipe_capture('git-rev-parse', '--verify', "$parent^0");
  52     chomp $parent;
  53     if ($?) {
  54         die "The parent reference did not resolve!";
  55     }
  56 }
  57
  58 # find parents from the commit itself
  59 my @commit  = safe_pipe_capture('git-cat-file', 'commit', $commit);
  60 my @parents;
  61 my $committer;
  62 my $author;
  63 my $stage = 'headers'; # headers, msg
  64 my $title;
  65 my $msg = '';
  66
  67 foreach my $line (@commit) {
  68     chomp $line;
  69     if ($stage eq 'headers' && $line eq '') {
  70         $stage = 'msg';
  71         next;
  72     }
  73
  74     if ($stage eq 'headers') {
  75         if ($line =~ m/^parent (\w{40})$/) { # found a parent
  76             push @parents, $1;
  77         } elsif ($line =~ m/^author (.+) \d+ [-+]\d+$/) {
  78             $author = $1;
  79         } elsif ($line =~ m/^committer (.+) \d+ [-+]\d+$/) {
  80             $committer = $1;
  81         }
  82     } else {
  83         $msg .= $line . "\n";
  84         unless ($title) {
  85             $title = $line;
  86         }
  87     }
  88 }
  89
  90 if ($parent) {
  91     my $found;
  92     # double check that it's a valid parent
  93     foreach my $p (@parents) {
  94         if ($p eq $parent) {
  95             $found = 1;
  96             last;
  97         }; # found it
  98     }
  99     die "Did not find $parent in the parents for this commit!" if !$found and !$opt_P;
 100 } else { # we don't have a parent from the cmdline...
 101     if (@parents == 1) { # it's safe to get it from the commit
 102         $parent = $parents[0];
 103     } else { # or perhaps not!
 104         die "This commit has more than one parent -- please name the parent you want to use explicitly";
 105     }
 106 }
 107
 108 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";
 109
 110 # grab the commit message
 111 open(MSG, ">.msg") or die "Cannot open .msg for writing";
 112 if ($opt_m) {
 113     print MSG $opt_m;
 114 }
 115 print MSG $msg;
 116 if ($opt_a) {
 117     print MSG "\n\nAuthor: $author\n";
 118     if ($author ne $committer) {
 119         print MSG "Committer: $committer\n";
 120     }
 121 }
 122 close MSG;
 123
 124 `git-diff-tree --binary -p $parent $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
 125
 126 ## apply non-binary changes
 127
 128 # In pedantic mode require all lines of context to match.  In normal
 129 # mode, be compatible with diff/patch: assume 3 lines of context and
 130 # require at least one line match, i.e. ignore at most 2 lines of
 131 # context, like diff/patch do by default.
 132 my $context = $opt_p ? '' : '-C1';
 133
 134 print "Checking if patch will apply\n";
 135
 136 my @stat;
 137 open APPLY, "GIT_DIR= git-apply $context --binary --summary --numstat<.cvsexportcommit.diff|" || die "cannot patch";
 138 @stat=<APPLY>;
 139 close APPLY || die "Cannot patch";
 140 my (@bfiles,@files,@afiles,@dfiles);
 141 chomp @stat;
 142 foreach (@stat) {
 143         push (@bfiles,$1) if m/^-\t-\t(.*)$/;
 144         push (@files, $1) if m/^-\t-\t(.*)$/;
 145         push (@files, $1) if m/^\d+\t\d+\t(.*)$/;
 146         push (@afiles,$1) if m/^ create mode [0-7]+ (.*)$/;
 147         push (@dfiles,$1) if m/^ delete mode [0-7]+ (.*)$/;
 148 }
 149 map { s/^"(.*)"$/$1/g } @bfiles,@files;
 150 map { s/\\([0-7]{3})/sprintf('%c',oct $1)/eg } @bfiles,@files;
 151
 152 # check that the files are clean and up to date according to cvs
 153 my $dirty;
 154 my @dirs;
 155 foreach my $p (@afiles) {
 156     my $path = dirname $p;
 157     while (!-d $path and ! grep { $_ eq $path } @dirs) {
 158         unshift @dirs, $path;
 159         $path = dirname $path;
 160     }
 161 }
 162
 163 foreach my $d (@dirs) {
 164     if (-e $d) {
 165         $dirty = 1;
 166         warn "$d exists and is not a directory!\n";
 167     }
 168 }
 169 foreach my $f (@afiles) {
 170     # This should return only one value
 171     if ($f =~ m,(.*)/[^/]*$,) {
 172         my $p = $1;
 173         next if (grep { $_ eq $p } @dirs);
 174     }
 175     my @status = grep(m/^File/,  safe_pipe_capture(@cvs, '-q', 'status' ,$f));
 176     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 177     if (-d dirname $f and $status[0] !~ m/Status: Unknown$/
 178         and $status[0] !~ m/^File: no file /) {
 179         $dirty = 1;
 180         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";
 181         warn "Status was: $status[0]\n";
 182     }
 183 }
 184
 185 foreach my $f (@files) {
 186     next if grep { $_ eq $f } @afiles;
 187     # TODO:we need to handle removed in cvs
 188     my @status = grep(m/^File/,  safe_pipe_capture(@cvs, '-q', 'status' ,$f));
 189     if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 190     unless ($status[0] =~ m/Status: Up-to-date$/) {
 191         $dirty = 1;
 192         warn "File $f not up to date in your CVS checkout!\n";
 193     }
 194 }
 195 if ($dirty) {
 196     if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 197         $dirty = 0;
 198     } else {
 199         die "Exiting: your CVS tree is not clean for this merge.";
 200     }
 201 }
 202
 203 print "Applying\n";
 204 `GIT_DIR= git-apply $context --binary --summary --numstat --apply <.cvsexportcommit.diff` || die "cannot patch";
 205
 206 print "Patch applied successfully. Adding new files and directories to CVS\n";
 207 my $dirtypatch = 0;
 208 foreach my $d (@dirs) {
 209     if (system(@cvs,'add',$d)) {
 210         $dirtypatch = 1;
 211         warn "Failed to cvs add directory $d -- you may need to do it manually";
 212     }
 213 }
 214
 215 foreach my $f (@afiles) {
 216     if (grep { $_ eq $f } @bfiles) {
 217       system(@cvs, 'add','-kb',$f);
 218     } else {
 219       system(@cvs, 'add', $f);
 220     }
 221     if ($?) {
 222         $dirtypatch = 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         $dirtypatch = 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 print "Patch title (first comment line): $title\n";
 237 my @commitfiles = map { unless (m/\s/) { '\''.$_.'\''; } else { $_; }; } (@files);
 238 my $cmd = join(' ', @cvs)." commit -F .msg @commitfiles";
 239
 240 if ($dirtypatch) {
 241     print "NOTE: One or more hunks failed to apply cleanly.\n";
 242     print "You'll need to apply the patch in .cvsexportcommit.diff manually\n";
 243     print "using a patch program. After applying the patch and resolving the\n";
 244     print "problems you may commit using:";
 245     print "\n    $cmd\n\n";
 246     exit(1);
 247 }
 248
 249 if ($opt_c) {
 250     print "Autocommit\n  $cmd\n";
 251     print safe_pipe_capture(@cvs, 'commit', '-F', '.msg', @files);
 252     if ($?) {
 253         die "Exiting: The commit did not succeed";
 254     }
 255     print "Committed successfully to CVS\n";
 256     # clean up
 257     unlink(".msg");
 258 } else {
 259     print "Ready for you to commit, just run:\n\n   $cmd\n";
 260 }
 261
 262 # clean up
 263 unlink(".cvsexportcommit.diff");
 264
 265 sub usage {
 266         print STDERR <<END;
 267 Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
 268 END
 269         exit(1);
 270 }
 271
 272 # An alternative to `command` that allows input to be passed as an array
 273 # to work around shell problems with weird characters in arguments
 274 # if the exec returns non-zero we die
 275 sub safe_pipe_capture {
 276     my @output;
 277     if (my $pid = open my $child, '-|') {
 278         @output = (<$child>);
 279         close $child or die join(' ',@_).": $! $?";
 280     } else {
 281         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 282     }
 283     return wantarray ? @output : join('',@output);
 284 }
 285
 286 sub safe_pipe_capture_blob {
 287     my $output;
 288     if (my $pid = open my $child, '-|') {
 289         local $/;
 290         undef $/;
 291         $output = (<$child>);
 292         close $child or die join(' ',@_).": $! $?";
 293     } else {
 294         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 295     }
 296     return $output;
 297 }