This is a test-only change except for the introduction of a new request
that is only used by tests.
Our notifications are dispatched in the XPC event handler, which is not
synchronized with replies to explicit XPC send_message_with_reply calls.
This is fine for most users of sourcekitd, since the notifications are
already enqueued on the client side, but for testing we need a way to
guarantee that all notifications are passed to the client-side handler
before we exit. This commit introduces a new request for testing that
triggers a notification, allowing the client to wait on that
notification to ensure all previously posted notifications have been
handled.
Note: the non-deterministic test failures can be triggered by adding a
sleep of ~100 ms in the event handler before the notification is
dispatched to the main queue.
rdar://40311995
... instead of an array of compiler arguments. This is good enough
for seeing what's going on, and it saves significant time for long
argument strings, because it doesn't create and destroy so many
xpc strings, and more of the string copying that happens is on a large
contiguous string instead of many small strings.
rdar://39538847
When enabled, send a notification before/after every "compilation",
which for now means `performSema`. This piggy-backs and modifies some
existing code that we had for "tracing" operations in sourcekitd that
unfortunately was untested. At least now some of the basic parts are
tested via the new notifications.
Part of rdar://38438512
