Checklist for Alpha 0.2.0

[StandingPadAnimations]

This checklist is the stuff left for the first alpha release of Resurgence:

• [ ] #8
• [ ] #9
• [x] #15
• [ ] Finish C FFI (including returning errors instead of just status)
• [x] Make sure @dynafide adds himself to Cargo.toml
• [x] Add drop to stack methods for the Rust and C APIs - [x] Make sure RunTimeSeal can catch most if not all attempts of tampering the runtime (this will definitely not be finished by the first alpha, but we can try our best) EDIT: RunTimeSeal will be removed as it doesn't bring much benefit
• [ ] Publish on Crates.io
• [x] Update diagrams in README
• [ ] Port RASM to Rust (requires code gen API to be finished)
• [x] Make sure that RASM can compile all instructions
• [x] BIG ONE: add Global support for FrameAlloc and FrameFree
• [x] Make sure function visibility is correct (internals should not be usable to the end user)

@dynafide anything else we need to check off before we release alpha 0.2.0?

[dynafide]

Two things I just thought of:

• A mechanism for extcall callbacks to put data into the VM (perhaps via a special register, or by pushing to the stack?)
• Some sort of way in the C FFI to retrieve the textual error message in the event that an error occurs (currently we only indicate the failure state by either returning a non-zero value or null pointers)

Otherwise, this list looks good! I will post here if I think of anything else.

[dynafide]

We have a series of 0.1.x versions already, so it looks like we will need to use 0.2.x for the alpha versions instead

[StandingPadAnimations]

A mechanism for extcall callbacks to put data into the VM (perhaps via a special register, or by pushing to the stack?)

Forgot about that, thanks for reminding me. I think we'll just push to the stack, since we already do that for arguments

[StandingPadAnimations]

Oh yeah @dynafide, don't forget to add yourself to the authors section of Cargo.toml, I'll add that to the checklist

[StandingPadAnimations]

One more thing: we need to go over the documentation of the internals and make it more consistent. The format for most things is as follows:

Description
arg (`Type`): description of what the argument is

codeblock-
example rust code 
-codeblock

[StandingPadAnimations]

Ok so there's a security issue in Resurgence, though I'm not sure if we should make a separate issue tracking it since it may be unfixable

So it seems to be possible for an API function to create an interpreter instance and execute arbitrary code. RunTimeSeal can't do much, as it's a per-instance thing.

[StandingPadAnimations]

Alright, I've added Rust support for dropping values on the stack. Now we just need the C wrappers

[StandingPadAnimations]

One important thing: guarantee exception safety for the FFI, as the Rust standard library can still throw exceptions