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