Simple assembly debugger

[frisitano]

This is a work in progress. This PR introduces a primitive miden assembly debugger. It allows the user to step through code and print out the vm state at each clock cycle. The debugger supports the following commands:

    --------------------------------------------------------
    Miden Assembly Debug CLI
    ---------------------------------------------------------
    !next        steps to the next clock cycle
    !play        executes program until completion or failure
    !play.n      executes n clock cycles
    !prev        steps to the previous clock cycle
    !rewind      rewinds program until beginning
    !rewind.n    rewinds n clock cycles
    !print       displays the complete state of the virtual machine
    !stack       displays the complete state of the stack
    !mem         displays the complete state of memory
    !mem[i]      displays memory at address i
    !help        displays this message

It can be invoked via the CLI using: ./miden debug -a ASSEMBLY_FILE.masm -i INPUT_FILE

Example:

[hackaugusto]

Tested locally, works as advertised. This is pretty awesome :)

I left one comment, but that is just a detail. I'm not going to merge so other people can review it too.

One thing that I haven't look at, do we have any sort of stack available? A way of figuring out where we are in the program.

[bobbinth]

Looks great! Thank you for doing this! I left a couple of comments inline, but I also thing we should update the docs to let people know about this. The docs could be updated in this PR or in a different PR (but then we should create an issue for this).

For doc updates, I'd add a bullet point in the "Running Miden VM" section for the debug command, but also I wonder if a separate section (similar to the one we have for REPL) is warranted. If we do add a separate section, we should probably break out REPL and Debug sections into their own files as (still sub-sections under "Usage").

[bobbinth]

Looks great! Thank you! I left a couple more comments inline - but to summarize:

• Let's remove VmState display logic from the processor crate. This should also fix the WASM compilation errors.
• Could you fix this minor issue: Simple assembly debugger #693 (comment)
• Let's create an issue for updating documentation (unless it has already been created).

[frisitano]

• Let's remove VmState display logic from the processor crate. This should also fix the WASM compilation errors.

Done.

• Could you fix this minor issue: #693 (comment)

I've removed all changes to the REPL module such that the debugger implementation is standalone. I've made this issue which states that we should consolidate documentation and logic between the debugger and REPL #699. It would also be cool to allow the REPL to be feature of the debugger. Say you get to a particular clock cycle and you then enter repl mode where you can specify new instructions against the wm.

• Let's create an issue for updating documentation (unless it has already been created).
  created

#699

[bobbinth]

All looks good! Thank you! I think we just need to resolve the merge conflict and then we can merge.