Better reporting of child exit statuses (esp. deaths due to signals).

[dgit.git] / dgit

diff --git a/dgit b/dgit
index b24264676f23de3e67c5a78592c51b7d6c921982..e3fc0eefd33bb6bf0372044f070cc7db03e0ad15 100755 (executable)
--- a/dgit
+++ b/dgit
@@ -30,6 +30,7 @@ use Dpkg::Version;
 use POSIX;
 use IPC::Open2;
 use Digest::SHA;
+use Config;
 
 our $our_version = 'UNRELEASED'; ###substituted###
 
@@ -133,6 +134,23 @@ END {
     }
 };
 
+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 printdebug { print DEBUG $debugprefix, @_ or die $!; }
 
 sub fail { 
@@ -350,10 +368,8 @@ sub failedcmd {
     { local ($!); printcmd \*STDERR, "$us: failed command:", @_ or die $!; };
     if ($!) {
        fail "failed to fork/exec: $!";
-    } elsif (!($? & 0xff)) {
-       fail "subprocess failed with error exit status ".($?>>8);
     } elsif ($?) {
-       fail "subprocess crashed (wait status $?)";
+       fail "subprocess ".waitstatusmsg();
     } else {
        fail "subprocess produced invalid output";
     }