Add an exception handler on Windows (#14582)
We've seen a few cases of uv.exe exiting with an exception code as its
exit status and no user-visible output (#14563 in the field, and #13812
in CI). It seems that recent versions of Windows no longer show dialog
boxes on access violations (what UNIX calls segfaults) or similar
errors. Something is probably sent to Windows Error Reporting, and we
can maybe sign up to get the crashes from Microsoft, but the user
experience of seeing uv exit with no output is poor, both for end users
and during development. While it's possible to opt out of this behavior
or set up a debugger, this isn't the default configuration. (See
https://superuser.com/q/1246626 for some pointers.)
In order to get some output on a crash, we need to install our own
default handler for unhandled exceptions (or call all our code inside a
Structured Exception Handling __try/__catch block, which is complicated
on Rust). This is the moral equivalent of a segfault handler on Windows;
the kernel creates a new stack frame and passes arguments to it with
some processor state.
This commit adds a relatively simple exception handler that leans on
Rust's own backtrace implementation and also displays some minimal
information from the exception itself. This should be enough info to
communicate that something went wrong and let us collect enough
information to attempt to debug. There are also a handful of (non-Rust)
open-source libraries for this like Breakpad and Crashpad (both from
Google) and crashrpt.
The approach here, of using SetUnhandledExceptionFilter, seems to be the
standard one taken by other such libraries. Crashpad also seems to try
to use a newer mechanism for an out-of-tree DLL to report the crash:
https://issues.chromium.org/issues/42310037
If we have serious problems with memory corruption, it might be worth
adopting some third-party library that has already implemented this
approach. (In general, the docs of other crash reporting libraries are
worth skimming to understand how these things ought to work.)
Co-authored-by: samypr100 <3933065+samypr100@users.noreply.github.com>
