Expand macros in the do_log macro after checking the log level
instead of each log macro (ie: SCLogDebug) expanding the macros
then passing off to do_log to have the log level check.
Will eliminate any expense of expanding macros if this log level
does not permit the given message to be logged.
Redmine issue:
https://redmine.openinfosecfoundation.org/issues/4114
Borrow a macro from https://github.com/popzxc/stdext-rs that
will give us the Rust function name in SCLog messages in Rust.
As this trick only works on Rust 1.38 and newer, keep the old
macro around and set a feature based on a Rust version test
done during ./configure.
Make sure the log level is setup with a pure Rust function, so
when it is set, its set within the address space of the caller.
This is important for Rust plugins where the Rust modules are not
in the address space of the Suricata main process.
The 'debug' feature is enabled if suricata was configured with the
--enabled-debug' flag.
If enabled, the SCLogDebug format and calls the logging function as
usual. Otherwise, this macro is a no-op (similarly to the C code).
In logging (SCLog*), safely convert strings to cstrings instead
of blindly unwrapping them.
Also implement a simple rust logger if the Suricata C context
is not available.
Where the context is a struct passed from C with pointers
to all the functions that may be called.
Instead of referencing C functions directly, wrap them
in function pointers so pure Rust unit tests can still run.