This commit marks (hopefully) ever one-parameter constructor as explicit.
It also uses override in (hopefully) all circumstances where a virtual
method is overridden.
There are a very few other minor changes - most of them were necessary
to get everything to compile (like one additional constructor). In one
case I changed an implicit operation to an explicit string conversion -
I think the automatically chosen conversion was much more convoluted.
This took longer than I want to admit but not as long as I feared :)
Also changed asynchronous data store query code a bit; trying to make
memory management and handling of corner cases a bit clearer (former
maybe could still be better, but I need to lookup queries by memory
address to associate response cookies to them, and so wrapping pointers
kind of just gets in the way).
- 'when' statements were problematic when used in a function/event/hook
that had local variables with an assigned function value. This was
because 'when' blocks operate on a clone of the frame and the cloning
process serializes locals and the serialization of functions had an
infinite cycle in it (ID -> BroFunc -> ID -> BroFunc ...). The ID
was only used for the function name and type information, so
refactoring Func and subclasses to depend on those two things instead
fixes the issue.
- 'return when' blocks, specifically, didn't work whenever execution
of the containing function's body does another function call before
reaching the 'return when' block, because of an assertion. This was
was due to logic in CallExpr::Eval always clearing the CallExpr
associated with the Frame after doing the call, instead of restoring
any previous CallExpr, which the code in Trigger::Eval expected to
have available.
- An assert could be reached when the condition of a 'when' statement
depended on checking the value of global state variables. The assert
in Trigger::QueueTrigger that checks that the Trigger isn't disabled
would get hit because Trigger::Eval/Timeout disable themselves after
running, but don't unregister themselves from the NotifierRegistry,
which keeps calling QueueTrigger for every state access of the global.
