Track #2: Syscall Handler

[drspacemn]

Implement the deprecated and stable syscall handler for SNOS. There are various places in which we need to be able to execute both deprecated and stable syscalls starting with block_context and the execution of the test transaction set. For syscall reference the cairo-lang pip package includes a json definition of both deprecated and new syscalls. To see:

• pip3 install cairo-lang==0.12.2
• cat ~/cairo_venv/lib/python3.9/site-packages/starkware/starknet/core/os/starknet_new_syscalls.json
• cat ~/cairo_venv/lib/python3.9/site-packages/starkware/starknet/core/os/starknet_syscalls.json

Exploration:

• blockifier has already done much of the implementation work here
• ideally we could use their hint processor directly
• as blockifier syscall implementation needs the block context we can most likely handle the logic via methods on the shared state struct

Setup for testing:

• reference for the pythonic syscall handler
• you will not be able to run the code, but can use it for testing logic/value reference
• we have a test fixture to run the initial transaction set run by the pythonic os testes here

[drspacemn]

It does not look like its going to be possible to use Blockifier's syscall handler as a drop in. Here are the OS syscall handler python references:

• https://github.com/starkware-libs/cairo-lang/blob/27a157d761ae49b242026bcbe5fca6e60c1e98bd/src/starkware/starknet/core/os/deprecated_syscall_handler.py#L713
• https://github.com/starkware-libs/cairo-lang/blob/27a157d761ae49b242026bcbe5fca6e60c1e98bd/src/starkware/starknet/core/os/syscall_handler.py#L1217
• https://github.com/starkware-libs/cairo-lang/blob/27a157d761ae49b242026bcbe5fca6e60c1e98bd/src/starkware/starknet/core/os/syscall_handler.py#L1038

[drspacemn]

moving away from large tickets