git-cvsexportcommit.perl

   1 #!/usr/bin/perl -w
   2
   3 use strict;
   4 use Getopt::Std;
   5 use File::Temp qw(tempdir);
   6 use Data::Dumper;
   7 use File::Basename qw(basename dirname);
   8 use File::Spec;
   9 use Git;
  10
  11 our ($opt_h, $opt_P, $opt_p, $opt_v, $opt_c, $opt_f, $opt_a, $opt_m, $opt_d, $opt_u, $opt_w, $opt_W);
  12
  13 getopts('uhPpvcfam:d:w:W');
  14
  15 $opt_h && usage();
  16
  17 die "Need at least one commit identifier!" unless @ARGV;
  18
  19 # Get git-config settings
  20 my $repo = Git->repository();
  21 $opt_w = $repo->config('cvsexportcommit.cvsdir') unless defined $opt_w;
  22
  23 if ($opt_w || $opt_W) {
  24         # Remember where GIT_DIR is before changing to CVS checkout
  25         unless ($ENV{GIT_DIR}) {
  26                 # No GIT_DIR set. Figure it out for ourselves
  27                 my $gd =`git-rev-parse --git-dir`;
  28                 chomp($gd);
  29                 $ENV{GIT_DIR} = $gd;
  30         }
  31         # Make sure GIT_DIR is absolute
  32         $ENV{GIT_DIR} = File::Spec->rel2abs($ENV{GIT_DIR});
  33 }
  34
  35 if ($opt_w) {
  36         if (! -d $opt_w."/CVS" ) {
  37                 die "$opt_w is not a CVS checkout";
  38         }
  39         chdir $opt_w or die "Cannot change to CVS checkout at $opt_w";
  40 }
  41 unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
  42     die "GIT_DIR is not defined or is unreadable";
  43 }
  44
  45
  46 my @cvs;
  47 if ($opt_d) {
  48         @cvs = ('cvs', '-d', $opt_d);
  49 } else {
  50         @cvs = ('cvs');
  51 }
  52
  53 # resolve target commit
  54 my $commit;
  55 $commit = pop @ARGV;
  56 $commit = safe_pipe_capture('git-rev-parse', '--verify', "$commit^0");
  57 chomp $commit;
  58 if ($?) {
  59     die "The commit reference $commit did not resolve!";
  60 }
  61
  62 # resolve what parent we want
  63 my $parent;
  64 if (@ARGV) {
  65     $parent = pop @ARGV;
  66     $parent =  safe_pipe_capture('git-rev-parse', '--verify', "$parent^0");
  67     chomp $parent;
  68     if ($?) {
  69         die "The parent reference did not resolve!";
  70     }
  71 }
  72
  73 # find parents from the commit itself
  74 my @commit  = safe_pipe_capture('git-cat-file', 'commit', $commit);
  75 my @parents;
  76 my $committer;
  77 my $author;
  78 my $stage = 'headers'; # headers, msg
  79 my $title;
  80 my $msg = '';
  81
  82 foreach my $line (@commit) {
  83     chomp $line;
  84     if ($stage eq 'headers' && $line eq '') {
  85         $stage = 'msg';
  86         next;
  87     }
  88
  89     if ($stage eq 'headers') {
  90         if ($line =~ m/^parent (\w{40})$/) { # found a parent
  91             push @parents, $1;
  92         } elsif ($line =~ m/^author (.+) \d+ [-+]\d+$/) {
  93             $author = $1;
  94         } elsif ($line =~ m/^committer (.+) \d+ [-+]\d+$/) {
  95             $committer = $1;
  96         }
  97     } else {
  98         $msg .= $line . "\n";
  99         unless ($title) {
 100             $title = $line;
 101         }
 102     }
 103 }
 104
 105 my $noparent = "0000000000000000000000000000000000000000";
 106 if ($parent) {
 107     my $found;
 108     # double check that it's a valid parent
 109     foreach my $p (@parents) {
 110         if ($p eq $parent) {
 111             $found = 1;
 112             last;
 113         }; # found it
 114     }
 115     die "Did not find $parent in the parents for this commit!" if !$found and !$opt_P;
 116 } else { # we don't have a parent from the cmdline...
 117     if (@parents == 1) { # it's safe to get it from the commit
 118         $parent = $parents[0];
 119     } elsif (@parents == 0) { # there is no parent
 120         $parent = $noparent;
 121     } else { # cannot choose automatically from multiple parents
 122         die "This commit has more than one parent -- please name the parent you want to use explicitly";
 123     }
 124 }
 125
 126 my $go_back_to = 0;
 127
 128 if ($opt_W) {
 129     $opt_v && print "Resetting to $parent\n";
 130     $go_back_to = `git symbolic-ref HEAD 2> /dev/null ||
 131         git rev-parse HEAD` || die "Could not determine current branch";
 132     system("git checkout -q $parent^0") && die "Could not check out $parent^0";
 133 }
 134
 135 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";
 136
 137 # grab the commit message
 138 open(MSG, ">.msg") or die "Cannot open .msg for writing";
 139 if ($opt_m) {
 140     print MSG $opt_m;
 141 }
 142 print MSG $msg;
 143 if ($opt_a) {
 144     print MSG "\n\nAuthor: $author\n";
 145     if ($author ne $committer) {
 146         print MSG "Committer: $committer\n";
 147     }
 148 }
 149 close MSG;
 150
 151 if ($parent eq $noparent) {
 152     `git-diff-tree --binary -p --root $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
 153 } else {
 154     `git-diff-tree --binary -p $parent $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
 155 }
 156
 157 ## apply non-binary changes
 158
 159 # In pedantic mode require all lines of context to match.  In normal
 160 # mode, be compatible with diff/patch: assume 3 lines of context and
 161 # require at least one line match, i.e. ignore at most 2 lines of
 162 # context, like diff/patch do by default.
 163 my $context = $opt_p ? '' : '-C1';
 164
 165 print "Checking if patch will apply\n";
 166
 167 my @stat;
 168 open APPLY, "GIT_DIR= git-apply $context --summary --numstat<.cvsexportcommit.diff|" || die "cannot patch";
 169 @stat=<APPLY>;
 170 close APPLY || die "Cannot patch";
 171 my (@bfiles,@files,@afiles,@dfiles);
 172 chomp @stat;
 173 foreach (@stat) {
 174         push (@bfiles,$1) if m/^-\t-\t(.*)$/;
 175         push (@files, $1) if m/^-\t-\t(.*)$/;
 176         push (@files, $1) if m/^\d+\t\d+\t(.*)$/;
 177         push (@afiles,$1) if m/^ create mode [0-7]+ (.*)$/;
 178         push (@dfiles,$1) if m/^ delete mode [0-7]+ (.*)$/;
 179 }
 180 map { s/^"(.*)"$/$1/g } @bfiles,@files;
 181 map { s/\\([0-7]{3})/sprintf('%c',oct $1)/eg } @bfiles,@files;
 182
 183 # check that the files are clean and up to date according to cvs
 184 my $dirty;
 185 my @dirs;
 186 foreach my $p (@afiles) {
 187     my $path = dirname $p;
 188     while (!-d $path and ! grep { $_ eq $path } @dirs) {
 189         unshift @dirs, $path;
 190         $path = dirname $path;
 191     }
 192 }
 193
 194 # ... check dirs,
 195 foreach my $d (@dirs) {
 196     if (-e $d) {
 197         $dirty = 1;
 198         warn "$d exists and is not a directory!\n";
 199     }
 200 }
 201
 202 # ... query status of all files that we have a directory for and parse output of 'cvs status' to %cvsstat.
 203 my @canstatusfiles;
 204 foreach my $f (@files) {
 205     my $path = dirname $f;
 206     next if (grep { $_ eq $path } @dirs);
 207     push @canstatusfiles, $f;
 208 }
 209
 210 my %cvsstat;
 211 if (@canstatusfiles) {
 212     if ($opt_u) {
 213       my @updated = xargs_safe_pipe_capture([@cvs, 'update'], @canstatusfiles);
 214       print @updated;
 215     }
 216     # "cvs status" reorders the parameters, notably when there are multiple
 217     # arguments with the same basename.  So be precise here.
 218
 219     my %added = map { $_ => 1 } @afiles;
 220     my %todo = map { $_ => 1 } @canstatusfiles;
 221
 222     while (%todo) {
 223       my @canstatusfiles2 = ();
 224       my %fullname = ();
 225       foreach my $name (keys %todo) {
 226         my $basename = basename($name);
 227
 228         $basename = "no file " . $basename if (exists($added{$basename}));
 229         $basename =~ s/^\s+//;
 230         $basename =~ s/\s+$//;
 231
 232         if (!exists($fullname{$basename})) {
 233           $fullname{$basename} = $name;
 234           push (@canstatusfiles2, $name);
 235           delete($todo{$name});
 236         }
 237       }
 238       my @cvsoutput;
 239       @cvsoutput = xargs_safe_pipe_capture([@cvs, 'status'], @canstatusfiles2);
 240       foreach my $l (@cvsoutput) {
 241         chomp $l;
 242         if ($l =~ /^File:\s+(.*\S)\s+Status: (.*)$/) {
 243           if (!exists($fullname{$1})) {
 244             print STDERR "Huh? Status reported for unexpected file '$1'\n";
 245           } else {
 246             $cvsstat{$fullname{$1}} = $2;
 247           }
 248         }
 249       }
 250     }
 251 }
 252
 253 # ... validate new files,
 254 foreach my $f (@afiles) {
 255     if (defined ($cvsstat{$f}) and $cvsstat{$f} ne "Unknown") {
 256         $dirty = 1;
 257         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";
 258         warn "Status was: $cvsstat{$f}\n";
 259     }
 260 }
 261 # ... validate known files.
 262 foreach my $f (@files) {
 263     next if grep { $_ eq $f } @afiles;
 264     # TODO:we need to handle removed in cvs
 265     unless (defined ($cvsstat{$f}) and $cvsstat{$f} eq "Up-to-date") {
 266         $dirty = 1;
 267         warn "File $f not up to date but has status '$cvsstat{$f}' in your CVS checkout!\n";
 268     }
 269 }
 270 if ($dirty) {
 271     if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 272         $dirty = 0;
 273     } else {
 274         die "Exiting: your CVS tree is not clean for this merge.";
 275     }
 276 }
 277
 278 print "Applying\n";
 279 if ($opt_W) {
 280     system("git checkout -q $commit^0") && die "cannot patch";
 281 } else {
 282     `GIT_DIR= git-apply $context --summary --numstat --apply <.cvsexportcommit.diff` || die "cannot patch";
 283 }
 284
 285 print "Patch applied successfully. Adding new files and directories to CVS\n";
 286 my $dirtypatch = 0;
 287
 288 #
 289 # We have to add the directories in order otherwise we will have
 290 # problems when we try and add the sub-directory of a directory we
 291 # have not added yet.
 292 #
 293 # Luckily this is easy to deal with by sorting the directories and
 294 # dealing with the shortest ones first.
 295 #
 296 @dirs = sort { length $a <=> length $b} @dirs;
 297
 298 foreach my $d (@dirs) {
 299     if (system(@cvs,'add',$d)) {
 300         $dirtypatch = 1;
 301         warn "Failed to cvs add directory $d -- you may need to do it manually";
 302     }
 303 }
 304
 305 foreach my $f (@afiles) {
 306     if (grep { $_ eq $f } @bfiles) {
 307       system(@cvs, 'add','-kb',$f);
 308     } else {
 309       system(@cvs, 'add', $f);
 310     }
 311     if ($?) {
 312         $dirtypatch = 1;
 313         warn "Failed to cvs add $f -- you may need to do it manually";
 314     }
 315 }
 316
 317 foreach my $f (@dfiles) {
 318     system(@cvs, 'rm', '-f', $f);
 319     if ($?) {
 320         $dirtypatch = 1;
 321         warn "Failed to cvs rm -f $f -- you may need to do it manually";
 322     }
 323 }
 324
 325 print "Commit to CVS\n";
 326 print "Patch title (first comment line): $title\n";
 327 my @commitfiles = map { unless (m/\s/) { '\''.$_.'\''; } else { $_; }; } (@files);
 328 my $cmd = join(' ', @cvs)." commit -F .msg @commitfiles";
 329
 330 if ($dirtypatch) {
 331     print "NOTE: One or more hunks failed to apply cleanly.\n";
 332     print "You'll need to apply the patch in .cvsexportcommit.diff manually\n";
 333     print "using a patch program. After applying the patch and resolving the\n";
 334     print "problems you may commit using:";
 335     print "\n    cd \"$opt_w\"" if $opt_w;
 336     print "\n    $cmd\n";
 337     print "\n    git checkout $go_back_to\n" if $go_back_to;
 338     print "\n";
 339     exit(1);
 340 }
 341
 342 if ($opt_c) {
 343     print "Autocommit\n  $cmd\n";
 344     print xargs_safe_pipe_capture([@cvs, 'commit', '-F', '.msg'], @files);
 345     if ($?) {
 346         die "Exiting: The commit did not succeed";
 347     }
 348     print "Committed successfully to CVS\n";
 349     # clean up
 350     unlink(".msg");
 351 } else {
 352     print "Ready for you to commit, just run:\n\n   $cmd\n";
 353 }
 354
 355 # clean up
 356 unlink(".cvsexportcommit.diff");
 357
 358 if ($opt_W) {
 359     system("git checkout $go_back_to") && die "cannot move back to $go_back_to";
 360     if (!($go_back_to =~ /^[0-9a-fA-F]{40}$/)) {
 361         system("git symbolic-ref HEAD $go_back_to") &&
 362             die "cannot move back to $go_back_to";
 363     }
 364 }
 365
 366 # CVS version 1.11.x and 1.12.x sleeps the wrong way to ensure the timestamp
 367 # used by CVS and the one set by subsequence file modifications are different.
 368 # If they are not different CVS will not detect changes.
 369 sleep(1);
 370
 371 sub usage {
 372         print STDERR <<END;
 373 Usage: GIT_DIR=/path/to/.git git cvsexportcommit [-h] [-p] [-v] [-c] [-f] [-u] [-w cvsworkdir] [-m msgprefix] [ parent ] commit
 374 END
 375         exit(1);
 376 }
 377
 378 # An alternative to `command` that allows input to be passed as an array
 379 # to work around shell problems with weird characters in arguments
 380 # if the exec returns non-zero we die
 381 sub safe_pipe_capture {
 382     my @output;
 383     if (my $pid = open my $child, '-|') {
 384         @output = (<$child>);
 385         close $child or die join(' ',@_).": $! $?";
 386     } else {
 387         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 388     }
 389     return wantarray ? @output : join('',@output);
 390 }
 391
 392 sub xargs_safe_pipe_capture {
 393         my $MAX_ARG_LENGTH = 65536;
 394         my $cmd = shift;
 395         my @output;
 396         my $output;
 397         while(@_) {
 398                 my @args;
 399                 my $length = 0;
 400                 while(@_ && $length < $MAX_ARG_LENGTH) {
 401                         push @args, shift;
 402                         $length += length($args[$#args]);
 403                 }
 404                 if (wantarray) {
 405                         push @output, safe_pipe_capture(@$cmd, @args);
 406                 }
 407                 else {
 408                         $output .= safe_pipe_capture(@$cmd, @args);
 409                 }
 410         }
 411         return wantarray ? @output : $output;
 412 }