[Grbl_Esp32 Issue#361] Circular includes of grbl.h?

I am working on a fork to implement a new custom machine based on the custommachinetemplate. I have found that the inverse kinematics function relies on a circular include of the grbl.h file. Specifically, the planlinedatat struct is undefined when the compiler enters the custommachinetemplate.h file, but by a nested series of #include “grbl.h” the struct is defined by the time it is used. Adding a header guard to the grbl.h file breaks custom machines that use inverse kinematics (tested with commit a9cc851 using the CPUMAPPOLARCOASTER config setting).

Unfortunately, NOT having a header guard breaks my custom machine code. My instinct is to just add a header guard to grbl.h, but I don’t have nearly deep enough knowledge of the code to know what other effects that might have. Was leaving out the header guard a conscious decision, and is there a good documentation somewhere of the funky dependencies it creates?

Sorry for the long post, I hope it is clear. Thanks so much for this great software, I’m super excited to get it fully ported to the machine I’m working with.