3. Frequently Asked Questions

3.1. Spicy Language

Are Spicy’s global variables really global?

Indeed, they are. Changes to global variables become visible to all Spicy code; their values are not associated with specific connections or other dynamic state. If they are public, they can even be accessed from other, unrelated modules as well. This all means that globals often won’t be the right tool for the job; it’s rare that a parser needs truly global state. Take a look at Contexts for a different mechanism tying state to the current connection, which is a much more common requirement.

3.2. Toolchain

Is there a way to speed up compilation of Spicy code?

Depending on the complexity of the Spicy code, processing through spicyc/spicyz/spicy-driver may take a bit. The bulk of the time time tends to be spent on compiling the generated C++ code; often about 80-90%. Make sure to run spicy-precompile-headers to speed that up a little. During development of new parsers, it also helps quite a bit to build non-optimized debug versions by adding --debug to the command-line.

If you want to see a break-down of where Spicy spends its time, run the tools with --report-times. (In the output at the end, jit refers to compiling generated C++ code).

3.3. Zeek

Do I need a Spicy installation for using the Zeek plugin?

No, if the Zeek plugin was compiled with --build-toolchain=no, it will not require Spicy to be installed on the system. It will only be able to load pre-compiled analyzers then (i.e., *.hlto files), which you can create on a similar system that has Spicy installed through spicyz. The build process will leave a binary distribution inside your build directory at zeek/plugin/Zeek_Spicy.tgz.

Does Spicy support Dynamic Protocol Detection (DPD)?

Yes, see the corresponding section on how to add it to your analyzers.

I have print statements in my Spicy grammar, why do I not see any output when running Zeek?

The Zeek plugin by default disables the output of Spicy-side print statements. To enable them, add Spicy::enable_print=T to the Zeek command line (or redef Spicy::enable_print=T; to a Zeek script that you are loading).