Andrew's git / gitweb.git / git-cvsexportcommit.perl
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git-cvsexportcommit.perlon commit Implement safe_strncpy() as strlcpy() and use it more. (bfbd0bb)
   1#!/usr/bin/perl -w
   2
   3# Known limitations:
   4# - cannot add or remove binary files
   5# - does not propagate permissions
   6# - tells "ready for commit" even when things could not be completed
   7#   (eg addition of a binary file)
   8
   9use strict;
  10use Getopt::Std;
  11use File::Temp qw(tempdir);
  12use Data::Dumper;
  13use File::Basename qw(basename dirname);
  14
  15unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
  16    die "GIT_DIR is not defined or is unreadable";
  17}
  18
  19our ($opt_h, $opt_p, $opt_v, $opt_c, $opt_f, $opt_m );
  20
  21getopts('hpvcfm:');
  22
  23$opt_h && usage();
  24
  25die "Need at least one commit identifier!" unless @ARGV;
  26
  27# setup a tempdir
  28our ($tmpdir, $tmpdirname) = tempdir('git-cvsapplycommit-XXXXXX',
  29                                     TMPDIR => 1,
  30                                     CLEANUP => 1);
  31
  32print Dumper(@ARGV);
  33# resolve target commit
  34my $commit;
  35$commit = pop @ARGV;
  36$commit = safe_pipe_capture('git-rev-parse', '--verify', "$commit^0");
  37chomp $commit;
  38if ($?) {
  39    die "The commit reference $commit did not resolve!";
  40}
  41
  42# resolve what parent we want
  43my $parent;
  44if (@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
  54my @commit  = safe_pipe_capture('git-cat-file', 'commit', $commit);
  55my @parents;
  56foreach my $p (@commit) {
  57    if ($p =~ m/^$/) { # end of commit headers, we're done
  58        last;
  59    }
  60    if ($p =~ m/^parent (\w{40})$/) { # found a parent
  61        push @parents, $1;
  62    }
  63}
  64
  65if ($parent) {
  66    # double check that it's a valid parent
  67    foreach my $p (@parents) {
  68        my $found;
  69        if ($p eq $parent) {
  70            $found = 1;
  71            last;
  72        }; # found it
  73        die "Did not find $parent in the parents for this commit!";
  74    }
  75} else { # we don't have a parent from the cmdline...
  76    if (@parents == 1) { # it's safe to get it from the commit
  77        $parent = $parents[0];
  78    } else { # or perhaps not!
  79        die "This commit has more than one parent -- please name the parent you want to use explicitly";
  80    }
  81}
  82
  83$opt_v && print "Applying to CVS commit $commit from parent $parent\n";
  84
  85# grab the commit message
  86open(MSG, ">.msg") or die "Cannot open .msg for writing";
  87print MSG $opt_m;
  88close MSG;
  89
  90`git-cat-file commit $commit | sed -e '1,/^\$/d' >> .msg`;
  91$? && die "Error extracting the commit message";
  92
  93my (@afiles, @dfiles, @mfiles, @dirs);
  94my @files = safe_pipe_capture('git-diff-tree', '-r', $parent, $commit);
  95#print @files;
  96$? && die "Error in git-diff-tree";
  97foreach my $f (@files) {
  98    chomp $f;
  99    my @fields = split(m!\s+!, $f);
 100    if ($fields[4] eq 'A') {
 101        my $path = $fields[5];
 102        push @afiles, $path;
 103        # add any needed parent directories
 104        $path = dirname $path;
 105        while (!-d $path and ! grep { $_ eq $path } @dirs) {
 106            unshift @dirs, $path;
 107            $path = dirname $path;
 108        }
 109    }
 110    if ($fields[4] eq 'M') {
 111        push @mfiles, $fields[5];
 112    }
 113    if ($fields[4] eq 'R') {
 114        push @dfiles, $fields[5];
 115    }
 116}
 117$opt_v && print "The commit affects:\n ";
 118$opt_v && print join ("\n ", @afiles,@mfiles,@dfiles) . "\n\n";
 119undef @files; # don't need it anymore
 120
 121# check that the files are clean and up to date according to cvs
 122my $dirty;
 123foreach my $d (@dirs) {
 124    if (-e $d) {
 125        $dirty = 1;
 126        warn "$d exists and is not a directory!\n";
 127    }
 128}
 129foreach my $f (@afiles) {
 130    # This should return only one value
 131    my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
 132    if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 133    if (-d dirname $f and $status[0] !~ m/Status: Unknown$/
 134        and $status[0] !~ m/^File: no file /) {
 135        $dirty = 1;
 136        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";
 137        warn "Status was: $status\n";
 138    }
 139}
 140foreach my $f (@mfiles, @dfiles) {
 141    # TODO:we need to handle removed in cvs
 142    my @status = grep(m/^File/,  safe_pipe_capture('cvs', '-q', 'status' ,$f));
 143    if (@status > 1) { warn 'Strange! cvs status returned more than one line?'};
 144    unless ($status[0] =~ m/Status: Up-to-date$/) {
 145        $dirty = 1;
 146        warn "File $f not up to date in your CVS checkout!\n";
 147    }
 148}
 149if ($dirty) {
 150    if ($opt_f) {       warn "The tree is not clean -- forced merge\n";
 151        $dirty = 0;
 152    } else {
 153        die "Exiting: your CVS tree is not clean for this merge.";
 154    }
 155}
 156
 157###
 158### NOTE: if you are planning to die() past this point
 159###       you MUST call cleanupcvs(@files) before die()
 160###
 161
 162
 163print "Creating new directories\n";
 164foreach my $d (@dirs) {
 165    unless (mkdir $d) {
 166        warn "Could not mkdir $d: $!";
 167        $dirty = 1;
 168    }
 169    `cvs add $d`;
 170    if ($?) {
 171        $dirty = 1;
 172        warn "Failed to cvs add directory $d -- you may need to do it manually";
 173    }
 174}
 175
 176print "'Patching' binary files\n";
 177
 178my @bfiles = grep(m/^Binary/, safe_pipe_capture('git-diff-tree', '-p', $parent, $commit));
 179@bfiles = map { chomp } @bfiles;
 180foreach my $f (@bfiles) {
 181    # check that the file in cvs matches the "old" file
 182    # extract the file to $tmpdir and comparre with cmp
 183    my $tree = safe_pipe_capture('git-rev-parse', "$parent^{tree}");
 184    chomp $tree;
 185    my $blob = `git-ls-tree $tree "$f" | cut -f 1 | cut -d ' ' -f 3`;
 186    chomp $blob;
 187    `git-cat-file blob $blob > $tmpdir/blob`;
 188    if (system('cmp', '-s', $f, "$tmpdir/blob")) {
 189        warn "Binary file $f in CVS does not match parent.\n";
 190        $dirty = 1;
 191        next;
 192    }
 193
 194    # replace with the new file
 195     `git-cat-file blob $blob > $f`;
 196
 197    # TODO: something smart with file modes
 198
 199}
 200if ($dirty) {
 201    cleanupcvs(@files);
 202    die "Exiting: Binary files in CVS do not match parent";
 203}
 204
 205## apply non-binary changes
 206my $fuzz = $opt_p ? 0 : 2;
 207
 208print "Patching non-binary files\n";
 209print `(git-diff-tree -p $parent -p $commit | patch -p1 -F $fuzz ) 2>&1`;
 210
 211my $dirtypatch = 0;
 212if (($? >> 8) == 2) {
 213    cleanupcvs(@files);
 214    die "Exiting: Patch reported serious trouble -- you will have to apply this patch manually";
 215} elsif (($? >> 8) == 1) { # some hunks failed to apply
 216    $dirtypatch = 1;
 217}
 218
 219foreach my $f (@afiles) {
 220    system('cvs', 'add', $f);
 221    if ($?) {
 222        $dirty = 1;
 223        warn "Failed to cvs add $f -- you may need to do it manually";
 224    }
 225}
 226
 227foreach my $f (@dfiles) {
 228    system('cvs', 'rm', '-f', $f);
 229    if ($?) {
 230        $dirty = 1;
 231        warn "Failed to cvs rm -f $f -- you may need to do it manually";
 232    }
 233}
 234
 235print "Commit to CVS\n";
 236my $commitfiles = join(' ', @afiles, @mfiles, @dfiles);
 237my $cmd = "cvs commit -F .msg $commitfiles";
 238
 239if ($dirtypatch) {
 240    print "NOTE: One or more hunks failed to apply cleanly.\n";
 241    print "Resolve the conflicts and then commit using:\n";
 242    print "\n    $cmd\n\n";
 243    exit(1);
 244}
 245
 246
 247if ($opt_c) {
 248    print "Autocommit\n  $cmd\n";
 249    print safe_pipe_capture('cvs', 'commit', '-F', '.msg', @afiles, @mfiles, @dfiles);
 250    if ($?) {
 251        cleanupcvs(@files);
 252        die "Exiting: The commit did not succeed";
 253    }
 254    print "Committed successfully to CVS\n";
 255} else {
 256    print "Ready for you to commit, just run:\n\n   $cmd\n";
 257}
 258sub usage {
 259        print STDERR <<END;
 260Usage: GIT_DIR=/path/to/.git ${\basename $0} [-h] [-p] [-v] [-c] [-f] [-m msgprefix] [ parent ] commit
 261END
 262        exit(1);
 263}
 264
 265# ensure cvs is clean before we die
 266sub cleanupcvs {
 267    my @files = @_;
 268    foreach my $f (@files) {
 269        system('cvs', '-q', 'update', '-C', $f);
 270        if ($?) {
 271            warn "Warning! Failed to cleanup state of $f\n";
 272        }
 273    }
 274}
 275
 276# An alterative to `command` that allows input to be passed as an array
 277# to work around shell problems with weird characters in arguments
 278# if the exec returns non-zero we die
 279sub safe_pipe_capture {
 280    my @output;
 281    if (my $pid = open my $child, '-|') {
 282        @output = (<$child>);
 283        close $child or die join(' ',@_).": $! $?";
 284    } else {
 285        exec(@_) or die "$! $?"; # exec() can fail the executable can't be found
 286    }
 287    return wantarray ? @output : join('',@output);
 288}