Re: bzr commit into mysql-5.1 branch (sven:2668) Bug#38817

[Sven Sandberg]

Hi Magnus!

I committed an update to BUG#38817, which should allow printing stack
traces on Pushbuild's Valgrind host (we discussed it on IRC, the problem
was just that gdb printed backtick after the binary's filename on that
host). Could you review it?

/Sven


Sven Sandberg wrote:
> #At file:///home/sven/bzr/b38817-mtr_core/5.1-rpl/
> 
>  2668 Sven Sandberg	2008-10-04
>       BUG#38817: please make mtr analyze crashes better
>       Post-push fixes making it work on pushbuild's valgrind host, and clarifying the
> output.
> modified:
>   mysql-test/lib/My/CoreDump.pm
> 
> per-file messages:
>   mysql-test/lib/My/CoreDump.pm
>     - Improved parsing of mtr output so that it works on pushbuild's "valgrind"
> host.
>     - Added stack trace for the thread that coredumped, to make output more readable
> when there are many threads.
>     - Added explanation of what the output consists of.
>     - Added early removal of temp file.
> === modified file 'mysql-test/lib/My/CoreDump.pm'
> --- a/mysql-test/lib/My/CoreDump.pm	2008-09-20 14:10:22 +0000
> +++ b/mysql-test/lib/My/CoreDump.pm	2008-10-04 07:49:09 +0000
> @@ -27,33 +27,33 @@ sub _gdb {
>  
>    return unless -f $core_name;
>  
> -  my $dir = tempdir( CLEANUP => 1 );
> -  my ($tmp, $tmp_name) = tempfile( DIR => $dir );
> +  # Find out name of binary that generated core
> +  `gdb -c '$core_name' -q --batch 2>&1` =~
> +    /Core was generated by `([^\s\'\`]+)/;
> +  my $binary= $1 or  return;
> +  print "Core generated by '$binary'\n";
>  
> +  # Create tempfile containing gdb commands
> +  my ($tmp, $tmp_name) = tempfile();
>    print $tmp
> +    "bt\n",
>      "thread apply all bt\n",
>      "quit\n";
> +  close $tmp or die "Error closing $tmp_name: $!";
>  
> -  # Find out name of binary that generated core
> -  my $list= `gdb -c $core_name -x $tmp_name -q --batch 2>&1`
> -    or return;
> -
> -  my $binary;
> -  foreach my $line (split('\n', $list))
> -  {
> -    $binary= $1
> -      if ($line =~ /Core was generated by `(\S+)/);
> -  }
> -
> -  return unless $binary;
> -
> -  print "Generated by '$binary'\n";
> +  # Run gdb
> +  my $gdb_output=
> +    `gdb '$binary' -c '$core_name' -x '$tmp_name' -q --batch 2>&1`;
>  
> -  my $list= `gdb $binary -c $core_name -x $tmp_name -q --batch 2>&1`
> -    or return;
> +  unlink $tmp_name or die "Error removing $tmp_name: $!";
>  
> -  print $list, "\n";
> +  return unless $gdb_output;
>  
> +  print <<EOF, $gdb_output, "\n";
> +Output from gdb follows. The first stack trace is from the failing thread.
> +The following stack traces are from all threads (so the failing one is
> +duplicated).
> +EOF
>    return 1;
>  }
>  
> 
> 


-- 
Sven Sandberg, Software Engineer
MySQL AB, www.mysql.com