The Vm struct is the core execution engine for Cubipods. It manages the stack, memory, storage, and lexer to execute EVM bytecode instructions.
Structure
pub struct Vm<'a> {
pub stack: Stack<String>,
pub lexer: Lexer<'a>,
pub memory: Memory,
pub storage: Storage,
pub history: History,
pub verbose: bool,
}
Methods
new()
Creates a new VM instance with the given bytecode.
The bytecode string to execute (with or without “0x” prefix)
Whether to enable verbose logging and history tracking
Result
Result<Vm, Box<dyn Error>>
Returns a new VM instance or an error if bytecode is invalid
let vm = Vm::new("0x600160020101", false)?;
run()
Executes the bytecode loaded in the VM.
Result
Result<(), Box<dyn Error>>
Returns Ok(()) on successful execution or an error if execution fails
let mut vm = Vm::new("0x600160020101", false)?;
vm.run()?;
Usage Examples
Basic Arithmetic
// ADD: 10 + 20 = 30 (0x1e in hex)
let bytecode = "6014600a01";
let mut vm = Vm::new(&bytecode, false)?;
vm.run()?;
assert_eq!(vm.stack.peek().unwrap(), "1e");
Memory Operations
// MSTORE: Store 0x20 at memory location 0x80
let bytecode = "6020608052";
let mut vm = Vm::new(&bytecode, false)?;
vm.run()?;
let data = unsafe { vm.memory.mload("80".parse::<Bytes32>()?) };
assert_eq!(data, Bytes32::from(32));
Storage Operations
// SSTORE: Save "hello" (0x68656c6c6f) in slot 1
let data = "68656c6c6f";
let bytecode = format!("64{data}600155");
let mut vm = Vm::new(&bytecode, false)?;
vm.run()?;
let result = vm.storage.sload("01".parse::<Bytes32>()?);
assert_eq!(result.unwrap().to_string(), data);
Stack Manipulation
// SWAP: Swap 3rd item with 1st item
// Stack before: [1, 2, 3]
// Stack after: [3, 2, 1]
let bytecode = "60016002600391";
let mut vm = Vm::new(&bytecode, false)?;
vm.run()?;
assert_eq!(vm.stack.peek().unwrap(), "01");
Supported Opcodes
The VM supports the following EVM opcodes:
- Arithmetic: ADD, MUL, SUB, DIV, MOD, EXP
- Comparison: LT, GT, EQ, ISZERO
- Bitwise: AND, OR, XOR, NOT, BYTE
- Cryptographic: KECCAK256
- Stack: PUSH, POP, DUP, SWAP
- Memory: MLOAD, MSTORE
- Storage: SLOAD, SSTORE
- Control: STOP
