X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=Debian%2FDgit.pm;h=a53cb822950d9df861ab80df8d0996145d444b2d;hb=03894a4813bd99f86c188de61d72c0a05833e5cb;hp=b21a431e2fa742b5d7da605383bd485d3c93e82d;hpb=8007c2b1326e7deffa1c71d2d51ebca08107084a;p=dgit.git

diff --git a/Debian/Dgit.pm b/Debian/Dgit.pm
index b21a431e..a53cb822 100644
--- a/Debian/Dgit.pm
+++ b/Debian/Dgit.pm
@@ -7,6 +7,7 @@ use warnings;
 
 use POSIX;
 use IO::Handle;
+use Config;
 
 BEGIN {
     use Exporter   ();
@@ -15,14 +16,17 @@ BEGIN {
     $VERSION     = 1.00;
     @ISA         = qw(Exporter);
     @EXPORT      = qw(debiantag server_branch server_ref
-                      stat_exists git_for_each_ref
-                      git_for_each_tag_referring
+                      stat_exists fail waitstatusmsg failedcmd
+                      cmdoutput cmdoutput_errok
+                      git_rev_parse git_for_each_ref
+                      git_for_each_tag_referring is_fast_fwd
                       $package_re $component_re $deliberately_re
                       $branchprefix
                       initdebug enabledebug enabledebuglevel
                       printdebug debugcmd
                       $debugprefix *debuglevel *DEBUG
                       shellquote printcmd);
+    # implicitly uses $main::us
     %EXPORT_TAGS = ( policyflags => [qw(NOFFCHECK FRESHREPO)] );
     @EXPORT_OK   = @{ $EXPORT_TAGS{policyflags} };
 }
@@ -113,6 +117,70 @@ sub stat_exists ($) {
     die "stat $f: $!";
 }
 
+sub _us () {
+    $::us // ($0 =~ m#[^/]*$#, $&);
+}
+
+sub fail { 
+    my $s = "@_\n";
+    my $prefix = _us().": ";
+    $s =~ s/^/$prefix/gm;
+    die $s;
+}
+
+our @signames = split / /, $Config{sig_name};
+
+sub waitstatusmsg () {
+    if (!$?) {
+	return "terminated, reporting successful completion";
+    } elsif (!($? & 255)) {
+	return "failed with error exit status ".WEXITSTATUS($?);
+    } elsif (WIFSIGNALED($?)) {
+	my $signum=WTERMSIG($?);
+	return "died due to fatal signal ".
+	    ($signames[$signum] // "number $signum").
+	    ($? & 128 ? " (core dumped)" : ""); # POSIX(3pm) has no WCOREDUMP
+    } else {
+	return "failed with unknown wait status ".$?;
+    }
+}
+
+sub failedcmd {
+    { local ($!); printcmd \*STDERR, _us().": failed command:", @_ or die $!; };
+    if ($!) {
+	fail "failed to fork/exec: $!";
+    } elsif ($?) {
+	fail "subprocess ".waitstatusmsg();
+    } else {
+	fail "subprocess produced invalid output";
+    }
+}
+
+sub cmdoutput_errok {
+    die Dumper(\@_)." ?" if grep { !defined } @_;
+    debugcmd "|",@_;
+    open P, "-|", @_ or die $!;
+    my $d;
+    $!=0; $?=0;
+    { local $/ = undef; $d = <P>; }
+    die $! if P->error;
+    if (!close P) { printdebug "=>!$?\n"; return undef; }
+    chomp $d;
+    $d =~ m/^.*/;
+    printdebug "=> \`$&'",(length $' ? '...' : ''),"\n" if $debuglevel>0; #';
+    return $d;
+}
+
+sub cmdoutput {
+    my $d = cmdoutput_errok @_;
+    defined $d or failedcmd @_;
+    return $d;
+}
+
+sub git_rev_parse ($) {
+    return cmdoutput qw(git rev-parse), "$_[0]~0";
+}
+
 sub git_for_each_ref ($$) {
     my ($pattern,$func) = @_;
     # calls $func->($objid,$objtype,$fullrefname,$reftail);
@@ -132,15 +200,31 @@ sub git_for_each_ref ($$) {
 
 sub git_for_each_tag_referring ($$) {
     my ($objreferring, $func) = @_;
-    # calls $func->($objid,$fullrefname,$tagname);
+    # calls $func->($tagobjid,$refobjid,$fullrefname,$tagname);
     printdebug "git_for_each_tag_referring ",
         ($objreferring // 'UNDEF'),"\n";
     git_for_each_ref('refs/tags', sub {
-	my ($objid,$objtype,$fullrefname,$tagname) = @_;
+	my ($tagobjid,$objtype,$fullrefname,$tagname) = @_;
 	return unless $objtype eq 'tag';
-	return if defined $objreferring and $objid ne $objreferring;
-	$func->($objid,$fullrefname,$tagname);
+	my $refobjid = git_rev_parse $tagobjid;
+	return unless
+	    !defined $objreferring # caller wants them all
+	    or $tagobjid eq $objreferring
+	    or $refobjid eq $objreferring;
+	$func->($tagobjid,$refobjid,$fullrefname,$tagname);
     });
 }
 
+sub is_fast_fwd ($$) {
+    my ($ancestor,$child) = @_;
+    my @cmd = (qw(git merge-base), $ancestor, $child);
+    my $mb = cmdoutput_errok @cmd;
+    if (defined $mb) {
+	return git_rev_parse($mb) eq git_rev_parse($ancestor);
+    } else {
+	$?==256 or failedcmd @cmd;
+	return 0;
+    }
+}
+
 1;