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, $opt_u);
  19
  20 getopts('uhPpvcfam: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 # 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 my $committer;
  57 my $author;
  58 my $stage = 'headers'; # headers, msg
  59 my $title;
  60 my $msg = '';
  61
  62 foreach my $line (@commit) {
  63     chomp $line;
  64     if ($stage eq 'headers' && $line eq '') {
  65         $stage = 'msg';
  66         next;
  67     }
  68
  69     if ($stage eq 'headers') {
  70         if ($line =~ m/^parent (\w{40})$/) { # found a parent
  71             push @parents, $1;
  72         } elsif ($line =~ m/^author (.+) \d+ [-+]\d+$/) {
  73             $author = $1;
  74         } elsif ($line =~ m/^committer (.+) \d+ [-+]\d+$/) {
  75             $committer = $1;
  76         }
  77     } else {
  78         $msg .= $line . "\n";
  79         unless ($title) {
  80             $title = $line;
  81         }
  82     }
  83 }
  84
  85 if ($parent) {
  86     my $found;
  87     # double check that it's a valid parent
  88     foreach my $p (@parents) {
  89         if ($p eq $parent) {
  90             $found = 1;
  91             last;
  92         }; # found it
  93     }
  94     die "Did not find $parent in the parents for this commit!" if !$found and !$opt_P;
  95 } else { # we don't have a parent from the cmdline...
  96     if (@parents == 1) { # it's safe to get it from the commit
  97         $parent = $parents[0];
  98     } else { # or perhaps not!
  99         die "This commit has more than one parent -- please name the parent you want to use explicitly";
 100     }
 101 }
 102
 103 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";
 104
 105 # grab the commit message
 106 open(MSG, ">.msg") or die "Cannot open .msg for writing";
 107 if ($opt_m) {
 108     print MSG $opt_m;
 109 }
 110 print MSG $msg;
 111 if ($opt_a) {
 112     print MSG "\n\nAuthor: $author\n";
 113     if ($author ne $committer) {
 114         print MSG "Committer: $committer\n";
 115     }
 116 }
 117 close MSG;
 118
 119 `git-diff-tree --binary -p $parent $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
 120
 121 ## apply non-binary changes
 122
 123 # In pedantic mode require all lines of context to match.  In normal
 124 # mode, be compatible with diff/patch: assume 3 lines of context and
 125 # require at least one line match, i.e. ignore at most 2 lines of
 126 # context, like diff/patch do by default.
 127 my $context = $opt_p ? '' : '-C1';
 128
 129 print "Checking if patch will apply\n";
 130
 131 my @stat;
 132 open APPLY, "GIT_DIR= git-apply $context --summary --numstat<.cvsexportcommit.diff|" || die "cannot patch";
 133 @stat=<APPLY>;
 134 close APPLY || die "Cannot patch";
 135 my (@bfiles,@files,@afiles,@dfiles);
 136 chomp @stat;
 137 foreach (@stat) {
 138         push (@bfiles,$1) if m/^-\t-\t(.*)$/;
 139         push (@files, $1) if m/^-\t-\t(.*)$/;
 140         push (@files, $1) if m/^\d+\t\d+\t(.*)$/;
 141         push (@afiles,$1) if m/^ create mode [0-7]+ (.*)$/;
 142         push (@dfiles,$1) if m/^ delete mode [0-7]+ (.*)$/;
 143 }
 144 map { s/^"(.*)"$/$1/g } @bfiles,@files;
 145 map { s/\\([0-7]{3})/sprintf('%c',oct $1)/eg } @bfiles,@files;
 146
 147 # check that the files are clean and up to date according to cvs
 148 my $dirty;
 149 my @dirs;
 150 foreach my $p (@afiles) {
 151     my $path = dirname $p;
 152     while (!-d $path and ! grep { $_ eq $path } @dirs) {
 153         unshift @dirs, $path;
 154         $path = dirname $path;
 155     }
 156 }
 157
 158 # ... check dirs,
 159 foreach my $d (@dirs) {
 160     if (-e $d) {
 161         $dirty = 1;
 162         warn "$d exists and is not a directory!\n";
 163     }
 164 }
 165
 166 # ... query status of all files that we have a directory for and parse output of 'cvs status' to %cvsstat.
 167 my @canstatusfiles;
 168 foreach my $f (@files) {
 169     my $path = dirname $f;
 170     next if (grep { $_ eq $path } @dirs);
 171     push @canstatusfiles, $f;
 172 }
 173
 174 my %cvsstat;
 175 if (@canstatusfiles) {
 176     if ($opt_u) {
 177       my @updated = safe_pipe_capture(@cvs, 'update', @canstatusfiles);
 178       print @updated;
 179     }
 180     my @cvsoutput;
 181     @cvsoutput= safe_pipe_capture(@cvs, 'status', @canstatusfiles);
 182     my $matchcount = 0;
 183     foreach my $l (@cvsoutput) {
 184         chomp $l;
 185         if ( $l =~ /^File:/ and  $l =~ /Status: (.*)$/ ) {
 186             $cvsstat{$canstatusfiles[$matchcount]} = $1;
 187             $matchcount++;
 188         }
 189     }
 190 }
 191
 192 # ... validate new files,
 193 foreach my $f (@afiles) {
 194     if (defined ($cvsstat{$f}) and $cvsstat{$f} ne "Unknown") {
 195         $dirty = 1;
 196         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";
 197         warn "Status was: $cvsstat{$f}\n";
 198     }
 199 }
 200 # ... validate known files.
 201 foreach my $f (@files) {
 202     next if grep { $_ eq $f } @afiles;
 203     # TODO:we need to handle removed in cvs
 204     unless (defined ($cvsstat{$f}) and $cvsstat{$f} eq "Up-to-date") {
 205         $dirty = 1;
 206         warn "File $f not up to date but has status '$cvsstat{$f}' in your CVS checkout!\n";
 207     }
 208 }
 209 if ($dirty) {
 210     if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 211         $dirty = 0;
 212     } else {
 213         die "Exiting: your CVS tree is not clean for this merge.";
 214     }
 215 }
 216
 217 print "Applying\n";
 218 `GIT_DIR= git-apply $context --summary --numstat --apply <.cvsexportcommit.diff` || die "cannot patch";
 219
 220 print "Patch applied successfully. Adding new files and directories to CVS\n";
 221 my $dirtypatch = 0;
 222 foreach my $d (@dirs) {
 223     if (system(@cvs,'add',$d)) {
 224         $dirtypatch = 1;
 225         warn "Failed to cvs add directory $d -- you may need to do it manually";
 226     }
 227 }
 228
 229 foreach my $f (@afiles) {
 230     if (grep { $_ eq $f } @bfiles) {
 231       system(@cvs, 'add','-kb',$f);
 232     } else {
 233       system(@cvs, 'add', $f);
 234     }
 235     if ($?) {
 236         $dirtypatch = 1;
 237         warn "Failed to cvs add $f -- you may need to do it manually";
 238     }
 239 }
 240
 241 foreach my $f (@dfiles) {
 242     system(@cvs, 'rm', '-f', $f);
 243     if ($?) {
 244         $dirtypatch = 1;
 245         warn "Failed to cvs rm -f $f -- you may need to do it manually";
 246     }
 247 }
 248
 249 print "Commit to CVS\n";
 250 print "Patch title (first comment line): $title\n";
 251 my @commitfiles = map { unless (m/\s/) { '\''.$_.'\''; } else { $_; }; } (@files);
 252 my $cmd = join(' ', @cvs)." commit -F .msg @commitfiles";
 253
 254 if ($dirtypatch) {
 255     print "NOTE: One or more hunks failed to apply cleanly.\n";
 256     print "You'll need to apply the patch in .cvsexportcommit.diff manually\n";
 257     print "using a patch program. After applying the patch and resolving the\n";
 258     print "problems you may commit using:";
 259     print "\n    $cmd\n\n";
 260     exit(1);
 261 }
 262
 263 if ($opt_c) {
 264     print "Autocommit\n  $cmd\n";
 265     print safe_pipe_capture(@cvs, 'commit', '-F', '.msg', @files);
 266     if ($?) {
 267         die "Exiting: The commit did not succeed";
 268     }
 269     print "Committed successfully to CVS\n";
 270     # clean up
 271     unlink(".msg");
 272 } else {
 273     print "Ready for you to commit, just run:\n\n   $cmd\n";
 274 }
 275
 276 # clean up
 277 unlink(".cvsexportcommit.diff");
 278
 279 # CVS version 1.11.x and 1.12.x sleeps the wrong way to ensure the timestamp
 280 # used by CVS and the one set by subsequence file modifications are different.
 281 # If they are not different CVS will not detect changes.
 282 sleep(1);
 283
 284 sub usage {
 285         print STDERR <<END;
 286 Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
 287 END
 288         exit(1);
 289 }
 290
 291 # An alternative to `command` that allows input to be passed as an array
 292 # to work around shell problems with weird characters in arguments
 293 # if the exec returns non-zero we die
 294 sub safe_pipe_capture {
 295     my @output;
 296     if (my $pid = open my $child, '-|') {
 297         @output = (<$child>);
 298         close $child or die join(' ',@_).": $! $?";
 299     } else {
 300         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 301     }
 302     return wantarray ? @output : join('',@output);
 303 }
 304
 305 sub safe_pipe_capture_blob {
 306     my $output;
 307     if (my $pid = open my $child, '-|') {
 308         local $/;
 309         undef $/;
 310         $output = (<$child>);
 311         close $child or die join(' ',@_).": $! $?";
 312     } else {
 313         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 314     }
 315     return $output;
 316 }