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', $opt_d);
  29 } else {
  30         @cvs = ('cvs');
  31 }
  32
  33 # setup a tempdir
  34 our ($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 my $noparent = "0000000000000000000000000000000000000000";
  91 if ($parent) {
  92     my $found;
  93     # double check that it's a valid parent
  94     foreach my $p (@parents) {
  95         if ($p eq $parent) {
  96             $found = 1;
  97             last;
  98         }; # found it
  99     }
 100     die "Did not find $parent in the parents for this commit!" if !$found and !$opt_P;
 101 } else { # we don't have a parent from the cmdline...
 102     if (@parents == 1) { # it's safe to get it from the commit
 103         $parent = $parents[0];
 104     } elsif (@parents == 0) { # there is no parent
 105         $parent = $noparent;
 106     } else { # cannot choose automatically from multiple parents
 107         die "This commit has more than one parent -- please name the parent you want to use explicitly";
 108     }
 109 }
 110
 111 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";
 112
 113 # grab the commit message
 114 open(MSG, ">.msg") or die "Cannot open .msg for writing";
 115 if ($opt_m) {
 116     print MSG $opt_m;
 117 }
 118 print MSG $msg;
 119 if ($opt_a) {
 120     print MSG "\n\nAuthor: $author\n";
 121     if ($author ne $committer) {
 122         print MSG "Committer: $committer\n";
 123     }
 124 }
 125 close MSG;
 126
 127 if ($parent eq $noparent) {
 128     `git-diff-tree --binary -p --root $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
 129 } else {
 130     `git-diff-tree --binary -p $parent $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
 131 }
 132
 133 ## apply non-binary changes
 134
 135 # In pedantic mode require all lines of context to match.  In normal
 136 # mode, be compatible with diff/patch: assume 3 lines of context and
 137 # require at least one line match, i.e. ignore at most 2 lines of
 138 # context, like diff/patch do by default.
 139 my $context = $opt_p ? '' : '-C1';
 140
 141 print "Checking if patch will apply\n";
 142
 143 my @stat;
 144 open APPLY, "GIT_DIR= git-apply $context --binary --summary --numstat<.cvsexportcommit.diff|" || die "cannot patch";
 145 @stat=<APPLY>;
 146 close APPLY || die "Cannot patch";
 147 my (@bfiles,@files,@afiles,@dfiles);
 148 chomp @stat;
 149 foreach (@stat) {
 150         push (@bfiles,$1) if m/^-\t-\t(.*)$/;
 151         push (@files, $1) if m/^-\t-\t(.*)$/;
 152         push (@files, $1) if m/^\d+\t\d+\t(.*)$/;
 153         push (@afiles,$1) if m/^ create mode [0-7]+ (.*)$/;
 154         push (@dfiles,$1) if m/^ delete mode [0-7]+ (.*)$/;
 155 }
 156 map { s/^"(.*)"$/$1/g } @bfiles,@files;
 157 map { s/\\([0-7]{3})/sprintf('%c',oct $1)/eg } @bfiles,@files;
 158
 159 # check that the files are clean and up to date according to cvs
 160 my $dirty;
 161 my @dirs;
 162 foreach my $p (@afiles) {
 163     my $path = dirname $p;
 164     while (!-d $path and ! grep { $_ eq $path } @dirs) {
 165         unshift @dirs, $path;
 166         $path = dirname $path;
 167     }
 168 }
 169
 170 # ... check dirs,
 171 foreach my $d (@dirs) {
 172     if (-e $d) {
 173         $dirty = 1;
 174         warn "$d exists and is not a directory!\n";
 175     }
 176 }
 177
 178 # ... query status of all files that we have a directory for and parse output of 'cvs status' to %cvsstat.
 179 my @canstatusfiles;
 180 foreach my $f (@files) {
 181     my $path = dirname $f;
 182     next if (grep { $_ eq $path } @dirs);
 183     push @canstatusfiles, $f;
 184 }
 185
 186 my %cvsstat;
 187 if (@canstatusfiles) {
 188     if ($opt_u) {
 189       my @updated = safe_pipe_capture(@cvs, 'update', @canstatusfiles);
 190       print @updated;
 191     }
 192     my @cvsoutput;
 193     @cvsoutput= safe_pipe_capture(@cvs, 'status', @canstatusfiles);
 194     my $matchcount = 0;
 195     foreach my $l (@cvsoutput) {
 196         chomp $l;
 197         if ( $l =~ /^File:/ and  $l =~ /Status: (.*)$/ ) {
 198             $cvsstat{$canstatusfiles[$matchcount]} = $1;
 199             $matchcount++;
 200         }
 201     }
 202 }
 203
 204 # ... validate new files,
 205 foreach my $f (@afiles) {
 206     if (defined ($cvsstat{$f}) and $cvsstat{$f} ne "Unknown") {
 207         $dirty = 1;
 208         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";
 209         warn "Status was: $cvsstat{$f}\n";
 210     }
 211 }
 212 # ... validate known files.
 213 foreach my $f (@files) {
 214     next if grep { $_ eq $f } @afiles;
 215     # TODO:we need to handle removed in cvs
 216     unless (defined ($cvsstat{$f}) and $cvsstat{$f} eq "Up-to-date") {
 217         $dirty = 1;
 218         warn "File $f not up to date but has status '$cvsstat{$f}' in your CVS checkout!\n";
 219     }
 220 }
 221 if ($dirty) {
 222     if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 223         $dirty = 0;
 224     } else {
 225         die "Exiting: your CVS tree is not clean for this merge.";
 226     }
 227 }
 228
 229 print "Applying\n";
 230 `GIT_DIR= git-apply $context --binary --summary --numstat --apply <.cvsexportcommit.diff` || die "cannot patch";
 231
 232 print "Patch applied successfully. Adding new files and directories to CVS\n";
 233 my $dirtypatch = 0;
 234
 235 #
 236 # We have to add the directories in order otherwise we will have
 237 # problems when we try and add the sub-directory of a directory we
 238 # have not added yet.
 239 #
 240 # Luckily this is easy to deal with by sorting the directories and
 241 # dealing with the shortest ones first.
 242 #
 243 @dirs = sort { length $a <=> length $b} @dirs;
 244
 245 foreach my $d (@dirs) {
 246     if (system(@cvs,'add',$d)) {
 247         $dirtypatch = 1;
 248         warn "Failed to cvs add directory $d -- you may need to do it manually";
 249     }
 250 }
 251
 252 foreach my $f (@afiles) {
 253     if (grep { $_ eq $f } @bfiles) {
 254       system(@cvs, 'add','-kb',$f);
 255     } else {
 256       system(@cvs, 'add', $f);
 257     }
 258     if ($?) {
 259         $dirtypatch = 1;
 260         warn "Failed to cvs add $f -- you may need to do it manually";
 261     }
 262 }
 263
 264 foreach my $f (@dfiles) {
 265     system(@cvs, 'rm', '-f', $f);
 266     if ($?) {
 267         $dirtypatch = 1;
 268         warn "Failed to cvs rm -f $f -- you may need to do it manually";
 269     }
 270 }
 271
 272 print "Commit to CVS\n";
 273 print "Patch title (first comment line): $title\n";
 274 my @commitfiles = map { unless (m/\s/) { '\''.$_.'\''; } else { $_; }; } (@files);
 275 my $cmd = join(' ', @cvs)." commit -F .msg @commitfiles";
 276
 277 if ($dirtypatch) {
 278     print "NOTE: One or more hunks failed to apply cleanly.\n";
 279     print "You'll need to apply the patch in .cvsexportcommit.diff manually\n";
 280     print "using a patch program. After applying the patch and resolving the\n";
 281     print "problems you may commit using:";
 282     print "\n    $cmd\n\n";
 283     exit(1);
 284 }
 285
 286 if ($opt_c) {
 287     print "Autocommit\n  $cmd\n";
 288     print safe_pipe_capture(@cvs, 'commit', '-F', '.msg', @files);
 289     if ($?) {
 290         die "Exiting: The commit did not succeed";
 291     }
 292     print "Committed successfully to CVS\n";
 293     # clean up
 294     unlink(".msg");
 295 } else {
 296     print "Ready for you to commit, just run:\n\n   $cmd\n";
 297 }
 298
 299 # clean up
 300 unlink(".cvsexportcommit.diff");
 301
 302 # CVS version 1.11.x and 1.12.x sleeps the wrong way to ensure the timestamp
 303 # used by CVS and the one set by subsequence file modifications are different.
 304 # If they are not different CVS will not detect changes.
 305 sleep(1);
 306
 307 sub usage {
 308         print STDERR <<END;
 309 Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
 310 END
 311         exit(1);
 312 }
 313
 314 # An alternative to `command` that allows input to be passed as an array
 315 # to work around shell problems with weird characters in arguments
 316 # if the exec returns non-zero we die
 317 sub safe_pipe_capture {
 318     my @output;
 319     if (my $pid = open my $child, '-|') {
 320         @output = (<$child>);
 321         close $child or die join(' ',@_).": $! $?";
 322     } else {
 323         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 324     }
 325     return wantarray ? @output : join('',@output);
 326 }
 327
 328 sub safe_pipe_capture_blob {
 329     my $output;
 330     if (my $pid = open my $child, '-|') {
 331         local $/;
 332         undef $/;
 333         $output = (<$child>);
 334         close $child or die join(' ',@_).": $! $?";
 335     } else {
 336         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 337     }
 338     return $output;
 339 }