On Mon, 05 Mar 2012 22:51:28 -0500, Jonathan M Davis <jmdavisp...@gmx.com>
wrote:
On Monday, March 05, 2012 21:04:20 Steven Schveighoffer wrote:
On Mon, 05 Mar 2012 20:17:32 -0500, Michel Fortin
<michel.for...@michelf.com> wrote:
> That said, throwing an exception might not be a better response all
the
> time. On my operating system (Mac OS X) when a program crashes I get a
> nice crash log with the date, a stack trace for each thread with named
> functions, the list of all loaded libraries, and the list of VM
regions
> dumped into ~/Library/Logs/CrashReporter/. That's very useful when you
> have a customer experiencing a crash with your software, as you can
ask
> for the crash log. Can't you do the same on other operating systems?
It depends on the OS facilities and the installed libraries for such
features. It's eminently possible, and I think on Windows, you can
catch
such exceptions too in external programs to do the same sort of dumping.
On Linux, you get a "Segmentation Fault" message (or nothing if you have
no terminal showing the output), and the program goes away. That's the
default behavior. I think it's better in any case to do *something*
other
than just print "Segmentation Fault" by default. If someone has a way
to
hook this in a better fashion, we can include that, but I hazard to
guess
it will not be on stock Linux boxes.
All you have to do is add a signal handler which handles SIGSEV and have
it
print out a stacktrace. It's pretty easy to do. It _is_ the sort of
thing that
programs may want to override (to handle other signals), so I'm not
quite sure
what the best way to handle that is without causing problems for them
(e.g.
initialization order could affect which handler is added last and is
therefore
the one used). Maybe a function should be added to druntime which wraps
the
glibc function so that programs can add their signal handler through
_it_, and
if that happens, the default one won't be used.
Install the default (stack-trace printing) handler before calling any of
the static constructors. Any call to signal after that will override the
installed handler.
-Steve
