git-cvsexportcommit.perl

   1 #!/usr/bin/perl
   2
   3 use 5.008;
   4 use strict;
   5 use warnings;
   6 use Getopt::Std;
   7 use File::Temp qw(tempdir);
   8 use Data::Dumper;
   9 use File::Basename qw(basename dirname);
  10 use File::Spec;
  11 use Git;
  12
  13 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, $opt_k);
  14
  15 getopts('uhPpvcfkam:d:w:W');
  16
  17 $opt_h && usage();
  18
  19 die "Need at least one commit identifier!" unless @ARGV;
  20
  21 # Get git-config settings
  22 my $repo = Git->repository();
  23 $opt_w = $repo->config('cvsexportcommit.cvsdir') unless defined $opt_w;
  24
  25 if ($opt_w || $opt_W) {
  26         # Remember where GIT_DIR is before changing to CVS checkout
  27         unless ($ENV{GIT_DIR}) {
  28                 # No GIT_DIR set. Figure it out for ourselves
  29                 my $gd =`git-rev-parse --git-dir`;
  30                 chomp($gd);
  31                 $ENV{GIT_DIR} = $gd;
  32         }
  33
  34         # On MSYS, convert a Windows-style path to an MSYS-style path
  35         # so that rel2abs() below works correctly.
  36         if ($^O eq 'msys') {
  37                 $ENV{GIT_DIR} =~ s#^([[:alpha:]]):/#/$1/#;
  38         }
  39
  40         # Make sure GIT_DIR is absolute
  41         $ENV{GIT_DIR} = File::Spec->rel2abs($ENV{GIT_DIR});
  42 }
  43
  44 if ($opt_w) {
  45         if (! -d $opt_w."/CVS" ) {
  46                 die "$opt_w is not a CVS checkout";
  47         }
  48         chdir $opt_w or die "Cannot change to CVS checkout at $opt_w";
  49 }
  50 unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
  51     die "GIT_DIR is not defined or is unreadable";
  52 }
  53
  54
  55 my @cvs;
  56 if ($opt_d) {
  57         @cvs = ('cvs', '-d', $opt_d);
  58 } else {
  59         @cvs = ('cvs');
  60 }
  61
  62 # resolve target commit
  63 my $commit;
  64 $commit = pop @ARGV;
  65 $commit = safe_pipe_capture('git-rev-parse', '--verify', "$commit^0");
  66 chomp $commit;
  67 if ($?) {
  68     die "The commit reference $commit did not resolve!";
  69 }
  70
  71 # resolve what parent we want
  72 my $parent;
  73 if (@ARGV) {
  74     $parent = pop @ARGV;
  75     $parent =  safe_pipe_capture('git-rev-parse', '--verify', "$parent^0");
  76     chomp $parent;
  77     if ($?) {
  78         die "The parent reference did not resolve!";
  79     }
  80 }
  81
  82 # find parents from the commit itself
  83 my @commit  = safe_pipe_capture('git-cat-file', 'commit', $commit);
  84 my @parents;
  85 my $committer;
  86 my $author;
  87 my $stage = 'headers'; # headers, msg
  88 my $title;
  89 my $msg = '';
  90
  91 foreach my $line (@commit) {
  92     chomp $line;
  93     if ($stage eq 'headers' && $line eq '') {
  94         $stage = 'msg';
  95         next;
  96     }
  97
  98     if ($stage eq 'headers') {
  99         if ($line =~ m/^parent (\w{40})$/) { # found a parent
 100             push @parents, $1;
 101         } elsif ($line =~ m/^author (.+) \d+ [-+]\d+$/) {
 102             $author = $1;
 103         } elsif ($line =~ m/^committer (.+) \d+ [-+]\d+$/) {
 104             $committer = $1;
 105         }
 106     } else {
 107         $msg .= $line . "\n";
 108         unless ($title) {
 109             $title = $line;
 110         }
 111     }
 112 }
 113
 114 my $noparent = "0000000000000000000000000000000000000000";
 115 if ($parent) {
 116     my $found;
 117     # double check that it's a valid parent
 118     foreach my $p (@parents) {
 119         if ($p eq $parent) {
 120             $found = 1;
 121             last;
 122         }; # found it
 123     }
 124     die "Did not find $parent in the parents for this commit!" if !$found and !$opt_P;
 125 } else { # we don't have a parent from the cmdline...
 126     if (@parents == 1) { # it's safe to get it from the commit
 127         $parent = $parents[0];
 128     } elsif (@parents == 0) { # there is no parent
 129         $parent = $noparent;
 130     } else { # cannot choose automatically from multiple parents
 131         die "This commit has more than one parent -- please name the parent you want to use explicitly";
 132     }
 133 }
 134
 135 my $go_back_to = 0;
 136
 137 if ($opt_W) {
 138     $opt_v && print "Resetting to $parent\n";
 139     $go_back_to = `git symbolic-ref HEAD 2> /dev/null ||
 140         git rev-parse HEAD` || die "Could not determine current branch";
 141     system("git checkout -q $parent^0") && die "Could not check out $parent^0";
 142 }
 143
 144 $opt_v && print "Applying to CVS commit $commit from parent $parent\n";
 145
 146 # grab the commit message
 147 open(MSG, ">.msg") or die "Cannot open .msg for writing";
 148 if ($opt_m) {
 149     print MSG $opt_m;
 150 }
 151 print MSG $msg;
 152 if ($opt_a) {
 153     print MSG "\n\nAuthor: $author\n";
 154     if ($author ne $committer) {
 155         print MSG "Committer: $committer\n";
 156     }
 157 }
 158 close MSG;
 159
 160 if ($parent eq $noparent) {
 161     `git-diff-tree --binary -p --root $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
 162 } else {
 163     `git-diff-tree --binary -p $parent $commit >.cvsexportcommit.diff`;# || die "Cannot diff";
 164 }
 165
 166 ## apply non-binary changes
 167
 168 # In pedantic mode require all lines of context to match.  In normal
 169 # mode, be compatible with diff/patch: assume 3 lines of context and
 170 # require at least one line match, i.e. ignore at most 2 lines of
 171 # context, like diff/patch do by default.
 172 my $context = $opt_p ? '' : '-C1';
 173
 174 print "Checking if patch will apply\n";
 175
 176 my @stat;
 177 open APPLY, "GIT_DIR= git-apply $context --summary --numstat<.cvsexportcommit.diff|" || die "cannot patch";
 178 @stat=<APPLY>;
 179 close APPLY || die "Cannot patch";
 180 my (@bfiles,@files,@afiles,@dfiles);
 181 chomp @stat;
 182 foreach (@stat) {
 183         push (@bfiles,$1) if m/^-\t-\t(.*)$/;
 184         push (@files, $1) if m/^-\t-\t(.*)$/;
 185         push (@files, $1) if m/^\d+\t\d+\t(.*)$/;
 186         push (@afiles,$1) if m/^ create mode [0-7]+ (.*)$/;
 187         push (@dfiles,$1) if m/^ delete mode [0-7]+ (.*)$/;
 188 }
 189 map { s/^"(.*)"$/$1/g } @bfiles,@files;
 190 map { s/\\([0-7]{3})/sprintf('%c',oct $1)/eg } @bfiles,@files;
 191
 192 # check that the files are clean and up to date according to cvs
 193 my $dirty;
 194 my @dirs;
 195 foreach my $p (@afiles) {
 196     my $path = dirname $p;
 197     while (!-d $path and ! grep { $_ eq $path } @dirs) {
 198         unshift @dirs, $path;
 199         $path = dirname $path;
 200     }
 201 }
 202
 203 # ... check dirs,
 204 foreach my $d (@dirs) {
 205     if (-e $d) {
 206         $dirty = 1;
 207         warn "$d exists and is not a directory!\n";
 208     }
 209 }
 210
 211 # ... query status of all files that we have a directory for and parse output of 'cvs status' to %cvsstat.
 212 my @canstatusfiles;
 213 foreach my $f (@files) {
 214     my $path = dirname $f;
 215     next if (grep { $_ eq $path } @dirs);
 216     push @canstatusfiles, $f;
 217 }
 218
 219 my %cvsstat;
 220 if (@canstatusfiles) {
 221     if ($opt_u) {
 222       my @updated = xargs_safe_pipe_capture([@cvs, 'update'], @canstatusfiles);
 223       print @updated;
 224     }
 225     # "cvs status" reorders the parameters, notably when there are multiple
 226     # arguments with the same basename.  So be precise here.
 227
 228     my %added = map { $_ => 1 } @afiles;
 229     my %todo = map { $_ => 1 } @canstatusfiles;
 230
 231     while (%todo) {
 232       my @canstatusfiles2 = ();
 233       my %fullname = ();
 234       foreach my $name (keys %todo) {
 235         my $basename = basename($name);
 236
 237         # CVS reports files that don't exist in the current revision as
 238         # "no file $basename" in its "status" output, so we should
 239         # anticipate that.  Totally unknown files will have a status
 240         # "Unknown". However, if they exist in the Attic, their status
 241         # will be "Up-to-date" (this means they were added once but have
 242         # been removed).
 243         $basename = "no file $basename" if $added{$basename};
 244
 245         $basename =~ s/^\s+//;
 246         $basename =~ s/\s+$//;
 247
 248         if (!exists($fullname{$basename})) {
 249           $fullname{$basename} = $name;
 250           push (@canstatusfiles2, $name);
 251           delete($todo{$name});
 252         }
 253       }
 254       my @cvsoutput;
 255       @cvsoutput = xargs_safe_pipe_capture([@cvs, 'status'], @canstatusfiles2);
 256       foreach my $l (@cvsoutput) {
 257         chomp $l;
 258         next unless
 259             my ($file, $status) = $l =~ /^File:\s+(.*\S)\s+Status: (.*)$/;
 260
 261         my $fullname = $fullname{$file};
 262         print STDERR "Huh? Status '$status' reported for unexpected file '$file'\n"
 263             unless defined $fullname;
 264
 265         # This response means the file does not exist except in
 266         # CVS's attic, so set the status accordingly
 267         $status = "In-attic"
 268             if $file =~ /^no file /
 269                 && $status eq 'Up-to-date';
 270
 271         $cvsstat{$fullname{$file}} = $status
 272             if defined $fullname{$file};
 273       }
 274     }
 275 }
 276
 277 # ... Validate that new files have the correct status
 278 foreach my $f (@afiles) {
 279     next unless defined(my $stat = $cvsstat{$f});
 280
 281     # This means the file has never been seen before
 282     next if $stat eq 'Unknown';
 283
 284     # This means the file has been seen before but was removed
 285     next if $stat eq 'In-attic';
 286
 287     $dirty = 1;
 288         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";
 289         warn "Status was: $cvsstat{$f}\n";
 290 }
 291
 292 # ... validate known files.
 293 foreach my $f (@files) {
 294     next if grep { $_ eq $f } @afiles;
 295     # TODO:we need to handle removed in cvs
 296     unless (defined ($cvsstat{$f}) and $cvsstat{$f} eq "Up-to-date") {
 297         $dirty = 1;
 298         warn "File $f not up to date but has status '$cvsstat{$f}' in your CVS checkout!\n";
 299     }
 300
 301     # Depending on how your GIT tree got imported from CVS you may
 302     # have a conflict between expanded keywords in your CVS tree and
 303     # unexpanded keywords in the patch about to be applied.
 304     if ($opt_k) {
 305         my $orig_file ="$f.orig";
 306         rename $f, $orig_file;
 307         open(FILTER_IN, "<$orig_file") or die "Cannot open $orig_file\n";
 308         open(FILTER_OUT, ">$f") or die "Cannot open $f\n";
 309         while (<FILTER_IN>)
 310         {
 311             my $line = $_;
 312             $line =~ s/\$([A-Z][a-z]+):[^\$]+\$/\$$1\$/g;
 313             print FILTER_OUT $line;
 314         }
 315         close FILTER_IN;
 316         close FILTER_OUT;
 317     }
 318 }
 319
 320 if ($dirty) {
 321     if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 322         $dirty = 0;
 323     } else {
 324         die "Exiting: your CVS tree is not clean for this merge.";
 325     }
 326 }
 327
 328 print "Applying\n";
 329 if ($opt_W) {
 330     system("git checkout -q $commit^0") && die "cannot patch";
 331 } else {
 332     `GIT_DIR= git-apply $context --summary --numstat --apply <.cvsexportcommit.diff` || die "cannot patch";
 333 }
 334
 335 print "Patch applied successfully. Adding new files and directories to CVS\n";
 336 my $dirtypatch = 0;
 337
 338 #
 339 # We have to add the directories in order otherwise we will have
 340 # problems when we try and add the sub-directory of a directory we
 341 # have not added yet.
 342 #
 343 # Luckily this is easy to deal with by sorting the directories and
 344 # dealing with the shortest ones first.
 345 #
 346 @dirs = sort { length $a <=> length $b} @dirs;
 347
 348 foreach my $d (@dirs) {
 349     if (system(@cvs,'add',$d)) {
 350         $dirtypatch = 1;
 351         warn "Failed to cvs add directory $d -- you may need to do it manually";
 352     }
 353 }
 354
 355 foreach my $f (@afiles) {
 356     if (grep { $_ eq $f } @bfiles) {
 357       system(@cvs, 'add','-kb',$f);
 358     } else {
 359       system(@cvs, 'add', $f);
 360     }
 361     if ($?) {
 362         $dirtypatch = 1;
 363         warn "Failed to cvs add $f -- you may need to do it manually";
 364     }
 365 }
 366
 367 foreach my $f (@dfiles) {
 368     system(@cvs, 'rm', '-f', $f);
 369     if ($?) {
 370         $dirtypatch = 1;
 371         warn "Failed to cvs rm -f $f -- you may need to do it manually";
 372     }
 373 }
 374
 375 print "Commit to CVS\n";
 376 print "Patch title (first comment line): $title\n";
 377 my @commitfiles = map { unless (m/\s/) { '\''.$_.'\''; } else { $_; }; } (@files);
 378 my $cmd = join(' ', @cvs)." commit -F .msg @commitfiles";
 379
 380 if ($dirtypatch) {
 381     print "NOTE: One or more hunks failed to apply cleanly.\n";
 382     print "You'll need to apply the patch in .cvsexportcommit.diff manually\n";
 383     print "using a patch program. After applying the patch and resolving the\n";
 384     print "problems you may commit using:";
 385     print "\n    cd \"$opt_w\"" if $opt_w;
 386     print "\n    $cmd\n";
 387     print "\n    git checkout $go_back_to\n" if $go_back_to;
 388     print "\n";
 389     exit(1);
 390 }
 391
 392 if ($opt_c) {
 393     print "Autocommit\n  $cmd\n";
 394     print xargs_safe_pipe_capture([@cvs, 'commit', '-F', '.msg'], @files);
 395     if ($?) {
 396         die "Exiting: The commit did not succeed";
 397     }
 398     print "Committed successfully to CVS\n";
 399     # clean up
 400     unlink(".msg");
 401 } else {
 402     print "Ready for you to commit, just run:\n\n   $cmd\n";
 403 }
 404
 405 # clean up
 406 unlink(".cvsexportcommit.diff");
 407
 408 if ($opt_W) {
 409     system("git checkout $go_back_to") && die "cannot move back to $go_back_to";
 410     if (!($go_back_to =~ /^[0-9a-fA-F]{40}$/)) {
 411         system("git symbolic-ref HEAD $go_back_to") &&
 412             die "cannot move back to $go_back_to";
 413     }
 414 }
 415
 416 # CVS version 1.11.x and 1.12.x sleeps the wrong way to ensure the timestamp
 417 # used by CVS and the one set by subsequence file modifications are different.
 418 # If they are not different CVS will not detect changes.
 419 sleep(1);
 420
 421 sub usage {
 422         print STDERR <<END;
 423 Usage: GIT_DIR=/path/to/.git git cvsexportcommit [-h] [-p] [-v] [-c] [-f] [-u] [-k] [-w cvsworkdir] [-m msgprefix] [ parent ] commit
 424 END
 425         exit(1);
 426 }
 427
 428 # An alternative to `command` that allows input to be passed as an array
 429 # to work around shell problems with weird characters in arguments
 430 # if the exec returns non-zero we die
 431 sub safe_pipe_capture {
 432     my @output;
 433     if (my $pid = open my $child, '-|') {
 434         @output = (<$child>);
 435         close $child or die join(' ',@_).": $! $?";
 436     } else {
 437         exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 438     }
 439     return wantarray ? @output : join('',@output);
 440 }
 441
 442 sub xargs_safe_pipe_capture {
 443         my $MAX_ARG_LENGTH = 65536;
 444         my $cmd = shift;
 445         my @output;
 446         my $output;
 447         while(@_) {
 448                 my @args;
 449                 my $length = 0;
 450                 while(@_ && $length < $MAX_ARG_LENGTH) {
 451                         push @args, shift;
 452                         $length += length($args[$#args]);
 453                 }
 454                 if (wantarray) {
 455                         push @output, safe_pipe_capture(@$cmd, @args);
 456                 }
 457                 else {
 458                         $output .= safe_pipe_capture(@$cmd, @args);
 459                 }
 460         }
 461         return wantarray ? @output : $output;
 462 }