3 # Debian::Dgit: functions common to dgit and its helpers and servers
5 # Copyright (C) 2015-2016 Ian Jackson
7 # This program is free software; you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation; either version 3 of the License, or
10 # (at your option) any later version.
12 # This program is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with this program. If not, see <http://www.gnu.org/licenses/>.
37 our ($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS);
41 @EXPORT = qw(setup_sigwarn forkcheck_setup forkcheck_mainprocess
43 debiantags debiantag_old debiantag_new
44 server_branch server_ref
45 stat_exists link_ltarget
47 fail ensuredir must_getcwd executable_on_path
48 waitstatusmsg failedcmd_waitstatus
49 failedcmd_report_cmd failedcmd
50 runcmd cmdoutput cmdoutput_errok
51 git_rev_parse git_cat_file
52 git_get_ref git_get_symref git_for_each_ref
53 git_for_each_tag_referring is_fast_fwd
55 $package_re $component_re $deliberately_re
56 $distro_re $versiontag_re $series_filename_re
57 $extra_orig_namepart_re
61 initdebug enabledebug enabledebuglevel
63 $debugprefix *debuglevel *DEBUG
64 shellquote printcmd messagequote
65 $negate_harmful_gitattrs
66 changedir git_slurp_config_src
68 # implicitly uses $main::us
69 %EXPORT_TAGS = ( policyflags => [qw(NOFFCHECK FRESHREPO NOCOMMITCHECK)],
70 playground => [qw(record_maindir $maindir $local_git_cfg
71 $maindir_gitdir $maindir_gitcommon
73 ensure_a_playground)]);
74 @EXPORT_OK = ( @{ $EXPORT_TAGS{policyflags} },
75 @{ $EXPORT_TAGS{playground} } );
80 our $package_re = '[0-9a-z][-+.0-9a-z]*';
81 our $component_re = '[0-9a-zA-Z][-+.0-9a-zA-Z]*';
82 our $deliberately_re = "(?:TEST-)?$package_re";
83 our $distro_re = $component_re;
84 our $versiontag_re = qr{[-+.\%_0-9a-zA-Z/]+};
85 our $branchprefix = 'dgit';
86 our $series_filename_re = qr{(?:^|\.)series(?!\n)$}s;
87 our $extra_orig_namepart_re = qr{[-0-9a-z]+};
88 our $git_null_obj = '0' x 40;
89 our $ffq_refprefix = 'ffq-prev';
91 # policy hook exit status bits
92 # see dgit-repos-server head comment for documentation
93 # 1 is reserved in case something fails with `exit 1' and to spot
94 # dynamic loader, runtime, etc., failures, which report 127 or 255
95 sub NOFFCHECK () { return 0x2; }
96 sub FRESHREPO () { return 0x4; }
97 sub NOCOMMITCHECK () { return 0x8; }
102 our $negate_harmful_gitattrs = "-text -eol -crlf -ident -filter";
104 our $forkcheck_mainprocess;
106 sub forkcheck_setup () {
107 $forkcheck_mainprocess = $$;
110 sub forkcheck_mainprocess () {
111 # You must have called forkcheck_setup or setup_sigwarn already
112 getppid != $forkcheck_mainprocess;
115 sub setup_sigwarn () {
117 $SIG{__WARN__} = sub {
118 confess $_[0] if forkcheck_mainprocess;
124 open DEBUG, ">/dev/null" or die $!;
128 open DEBUG, ">&STDERR" or die $!;
133 sub enabledebuglevel ($) {
134 my ($newlevel) = @_; # may be undef (eg from env var)
138 return unless $newlevel;
139 $debuglevel = $newlevel;
144 print DEBUG $debugprefix, @_ or die $! if $debuglevel>0;
147 sub messagequote ($) {
153 s{[\000-\037\177]}{ sprintf "\\x%02x", ord $& }ge;
160 defined or confess 'internal error' foreach @_;
163 if (!length || m{[^-=_./:0-9a-z]}i) {
170 return join ' ', @out;
175 my $intro = shift @_;
176 print $fh $intro," " or die $!;
177 print $fh shellquote @_ or die $!;
178 print $fh "\n" or die $!;
182 my $extraprefix = shift @_;
183 printcmd(\*DEBUG,$debugprefix.$extraprefix,@_) if $debuglevel>0;
186 sub dep14_version_mangle ($) {
188 # DEP-14 patch proposed 2016-11-09 "Version Mangling"
190 $v =~ s/\.(?=\.|$|lock$)/.#/g;
194 sub debiantag_old ($$) {
195 my ($v,$distro) = @_;
196 return "$distro/". dep14_version_mangle $v;
199 sub debiantag_new ($$) {
200 my ($v,$distro) = @_;
201 return "archive/$distro/".dep14_version_mangle $v;
204 sub debiantags ($$) {
205 my ($version,$distro) = @_;
206 map { $_->($version, $distro) } (\&debiantag_new, \&debiantag_old);
209 sub server_branch ($) { return "$branchprefix/$_[0]"; }
210 sub server_ref ($) { return "refs/".server_branch($_[0]); }
212 sub stat_exists ($) {
215 return 0 if $!==&ENOENT;
220 $::us // ($0 =~ m#[^/]*$#, $&);
226 my $prefix = _us().": ";
227 $s =~ s/^/$prefix/gm;
232 my ($dir) = @_; # does not create parents
233 return if mkdir $dir;
234 return if $! == EEXIST;
235 die "mkdir $dir: $!";
240 defined $d or fail "getcwd failed: $!";
244 sub executable_on_path ($) {
246 return 1 if $program =~ m{/};
247 my @path = split /:/, ($ENV{PATH} // "/usr/local/bin:/bin:/usr/bin");
248 foreach my $pe (@path) {
249 my $here = "$pe/$program";
250 return $here if stat_exists $here && -x _;
255 our @signames = split / /, $Config{sig_name};
257 sub waitstatusmsg () {
259 return "terminated, reporting successful completion";
260 } elsif (!($? & 255)) {
261 return "failed with error exit status ".WEXITSTATUS($?);
262 } elsif (WIFSIGNALED($?)) {
263 my $signum=WTERMSIG($?);
264 return "died due to fatal signal ".
265 ($signames[$signum] // "number $signum").
266 ($? & 128 ? " (core dumped)" : ""); # POSIX(3pm) has no WCOREDUMP
268 return "failed with unknown wait status ".$?;
272 sub failedcmd_report_cmd {
273 my $intro = shift @_;
274 $intro //= "failed command";
275 { local ($!); printcmd \*STDERR, _us().": $intro:", @_ or die $!; };
278 sub failedcmd_waitstatus {
280 return "failed to fork/exec: $!";
282 return "subprocess ".waitstatusmsg();
284 return "subprocess produced invalid output";
289 # Expects $!,$? as set by close - see below.
290 # To use with system(), set $?=-1 first.
292 # Actual behaviour of perl operations:
293 # success $!==0 $?==0 close of piped open
294 # program failed $!==0 $? >0 close of piped open
295 # syscall failure $! >0 $?=-1 close of piped open
296 # failure $! >0 unchanged close of something else
297 # success trashed $?==0 system
298 # program failed trashed $? >0 system
299 # syscall failure $! >0 unchanged system
300 failedcmd_report_cmd undef, @_;
301 fail failedcmd_waitstatus();
307 failedcmd @_ if system @_;
310 sub cmdoutput_errok {
311 confess Dumper(\@_)." ?" if grep { !defined } @_;
313 open P, "-|", @_ or die "$_[0] $!";
316 { local $/ = undef; $d = <P>; }
318 if (!close P) { printdebug "=>!$?\n"; return undef; }
320 if ($debuglevel > 0) {
323 my $more = (length $' ? '...' : ''); #');
324 $dd =~ s{[^\n -~]|\\}{ sprintf "\\x%02x", ord $& }ge;
325 printdebug "=> \`$dd'",$more,"\n";
331 my $d = cmdoutput_errok @_;
332 defined $d or failedcmd @_;
336 sub link_ltarget ($$) {
338 lstat $old or return undef;
340 $old = cmdoutput qw(realpath --), $old;
342 my $r = link $old, $new;
343 $r = symlink $old, $new if !$r && $!==EXDEV;
344 $r or die "(sym)link $old $new: $!";
349 my $h = Digest::SHA->new(256);
351 return $h->hexdigest();
354 sub git_rev_parse ($) {
355 return cmdoutput qw(git rev-parse), "$_[0]~0";
358 sub git_cat_file ($;$) {
359 my ($objname, $etype) = @_;
360 # => ($type, $data) or ('missing', undef)
361 # in scalar context, just the data
362 # if $etype defined, dies unless type is $etype or in @$etype
363 our ($gcf_pid, $gcf_i, $gcf_o);
365 my ($gtype, $data) = @_;
367 $etype = [$etype] unless ref $etype;
368 confess "$objname expected @$etype but is $gtype"
369 unless grep { $gtype eq $_ } @$etype;
371 return ($gtype, $data);
374 my @cmd = qw(git cat-file --batch);
375 debugcmd "GCF|", @cmd;
376 $gcf_pid = open2 $gcf_o, $gcf_i, @cmd or die $!;
378 printdebug "GCF>| ", $objname, "\n";
379 print $gcf_i $objname, "\n" or die $!;
381 printdebug "GCF<| ", $x;
382 if ($x =~ m/ (missing)$/) { return $chk->($1, undef); }
383 my ($type, $size) = $x =~ m/^.* (\w+) (\d+)\n/ or die "$objname ?";
385 (read $gcf_o, $data, $size) == $size or die "$objname $!";
387 $x eq "\n" or die "$objname ($_) $!";
388 return $chk->($type, $data);
391 sub git_get_symref (;$) {
392 my ($symref) = @_; $symref //= 'HEAD';
393 # => undef if not a symref, otherwise refs/...
394 my @cmd = (qw(git symbolic-ref -q HEAD));
395 my $branch = cmdoutput_errok @cmd;
396 if (!defined $branch) {
397 $?==256 or failedcmd @cmd;
404 sub git_for_each_ref ($$;$) {
405 my ($pattern,$func,$gitdir) = @_;
406 # calls $func->($objid,$objtype,$fullrefname,$reftail);
407 # $reftail is RHS of ref after refs/[^/]+/
408 # breaks if $pattern matches any ref `refs/blah' where blah has no `/'
409 # $pattern may be an array ref to mean multiple patterns
410 $pattern = [ $pattern ] unless ref $pattern;
411 my @cmd = (qw(git for-each-ref), @$pattern);
412 if (defined $gitdir) {
413 @cmd = ('sh','-ec','cd "$1"; shift; exec "$@"','x', $gitdir, @cmd);
415 open GFER, "-|", @cmd or die $!;
419 printdebug "|> ", $_, "\n";
420 m#^(\w+)\s+(\w+)\s+(refs/[^/]+/(\S+))$# or die "$_ ?";
421 $func->($1,$2,$3,$4);
423 $!=0; $?=0; close GFER or die "$pattern $? $!";
426 sub git_get_ref ($) {
427 # => '' if no such ref
430 s{^refs/}{[r]efs/} or die "$refname $_ ?";
431 return cmdoutput qw(git for-each-ref --format=%(objectname)), $_;
434 sub git_for_each_tag_referring ($$) {
435 my ($objreferring, $func) = @_;
436 # calls $func->($tagobjid,$refobjid,$fullrefname,$tagname);
437 printdebug "git_for_each_tag_referring ",
438 ($objreferring // 'UNDEF'),"\n";
439 git_for_each_ref('refs/tags', sub {
440 my ($tagobjid,$objtype,$fullrefname,$tagname) = @_;
441 return unless $objtype eq 'tag';
442 my $refobjid = git_rev_parse $tagobjid;
444 !defined $objreferring # caller wants them all
445 or $tagobjid eq $objreferring
446 or $refobjid eq $objreferring;
447 $func->($tagobjid,$refobjid,$fullrefname,$tagname);
451 sub git_check_unmodified () {
452 foreach my $cached (qw(0 1)) {
453 my @cmd = qw(git diff --quiet);
454 push @cmd, qw(--cached) if $cached;
457 $!=0; $?=-1; system @cmd;
462 ? "git index contains changes (does not match HEAD)"
463 : "working tree is dirty (does not match HEAD)";
470 sub is_fast_fwd ($$) {
471 my ($ancestor,$child) = @_;
472 my @cmd = (qw(git merge-base), $ancestor, $child);
473 my $mb = cmdoutput_errok @cmd;
475 return git_rev_parse($mb) eq git_rev_parse($ancestor);
477 $?==256 or failedcmd @cmd;
484 printdebug "CD $newdir\n";
485 chdir $newdir or confess "chdir: $newdir: $!";
488 sub git_slurp_config_src ($) {
490 # returns $r such that $r->{KEY}[] = VALUE
491 my @cmd = (qw(git config -z --get-regexp), "--$src", qw(.*));
494 local ($debuglevel) = $debuglevel-2;
498 open GITS, "-|", @cmd or die $!;
501 printdebug "=> ", (messagequote $_), "\n";
503 push @{ $r->{$`} }, $'; #';
507 or ($!==0 && $?==256)
512 # ========== playground handling ==========
516 # $maindir user's git working tree
517 # playground area in .git/ where we can make files, unpack, etc. etc.
518 # playtree git working tree sharing object store with the user's
519 # inside playground, or identical to it
523 # $local_git_cfg hash of arrays of values: git config from $maindir
525 # expected calling pattern
530 # must be run in directory containing .git
531 # assigns to $maindir if not already set
532 # also calls git_slurp_config_src to record git config
533 # in $local_git_cfg, unless it's already set
535 # fresh_playground SUBDIR_PATH_COMPONENTS
536 # e.g fresh_playground 'dgit/unpack' ('.git/' is implied)
537 # default SUBDIR_PATH_COMPONENTS is playground_subdir
538 # calls record_maindir
539 # sets up a new playground (destroying any old one)
540 # returns playground pathname
541 # caller may call multiple times with different subdir paths
542 # createing different playgrounds
544 # ensure_a_playground SUBDIR_PATH_COMPONENTS
545 # like fresh_playground except:
546 # merely ensures the directory exists; does not delete an existing one
550 # changedir playground
553 # playtree_setup $local_git_cfg
554 # # ^ call in some (perhaps trivial) subdir of playground
558 # ----- maindir -----
560 # these three all go together
563 our $maindir_gitcommon;
567 sub record_maindir () {
568 if (!defined $maindir) {
569 $maindir = must_getcwd();
570 if (!stat "$maindir/.git") {
571 fail "cannot stat $maindir/.git: $!";
574 # we fall back to this in case we have a pre-worktree
575 # git, which may not know git rev-parse --git-common-dir
576 $maindir_gitdir = "$maindir/.git";
577 $maindir_gitcommon = "$maindir/.git";
579 $maindir_gitdir = cmdoutput qw(git rev-parse --git-dir);
580 $maindir_gitcommon = cmdoutput qw(git rev-parse --git-common-dir);
583 $local_git_cfg //= git_slurp_config_src 'local';
586 # ----- playgrounds -----
588 sub ensure_a_playground_parent ($) {
591 $spc = "$maindir_gitdir/$spc";
592 my $parent = dirname $spc;
593 mkdir $parent or $!==EEXIST
594 or fail "failed to mkdir playground parent $parent: $!";
598 sub ensure_a_playground ($) {
600 $spc = ensure_a_playground_parent $spc;
601 mkdir $spc or $!==EEXIST or fail "failed to mkdir a playground $spc: $!";
605 sub fresh_playground ($) {
607 $spc = ensure_a_playground_parent $spc;
609 mkdir $spc or fail "failed to mkdir the playground $spc: $!";
613 # ----- playtrees -----
615 sub playtree_setup (;$) {
616 my ($t_local_git_cfg) = @_;
617 $t_local_git_cfg //= $local_git_cfg;
618 # for use in the playtree
619 # $maindir must be set, eg by calling record_maindir or fresh_playground
620 runcmd qw(git init -q);
621 runcmd qw(git config gc.auto 0);
622 foreach my $copy (qw(user.email user.name user.useConfigOnly
623 core.sharedRepository
624 core.compression core.looseCompression
625 core.bigFileThreshold core.fsyncObjectFiles)) {
626 my $v = $t_local_git_cfg->{$copy};
628 runcmd qw(git config), $copy, $_ foreach @$v;
630 # this is confusing: we have
631 # . playtree, not a worktree, has .git/, our cwd
632 # $maindir might be a worktree so
633 # $maindir_gitdir contains our main working "dgit", HEAD, etc.
634 # $maindir_gitcommon the shared stuff, including .objects
635 rmtree('.git/objects');
636 symlink "$maindir_gitcommon/objects",'.git/objects' or die $!;
637 ensuredir '.git/info';
638 open GA, "> .git/info/attributes" or die $!;
639 print GA "* $negate_harmful_gitattrs\n" or die $!;