fn default() -> Self {

Self::new()

}

/// Creates a new BytecodeValidator.

pub fn new() -> Self {

Self

}

/// Validates the module.

pub fn validate(&self, module: &BytecodeModule) -> Result<(), String> {

for func in &module.functions {

let num_insts = func.chunk.instructions.len();

let mut stack_height = 0i32;

for (idx, inst) in func.chunk.instructions.iter().enumerate() {

// 1. Stack height check

let effect = inst.op.stack_effect();

stack_height += effect;

if stack_height < 0 {

return Err(format!(

"Validation error in function '{}': Stack underflow at instruction index {}",

func.name, idx

));

}

// 2. Operand checks

for op in &inst.operands {

match op {

Operand::ConstantIndex(c_idx) => {

if func.chunk.constants.get(*c_idx).is_none() {

return Err(format!(

"Validation error in function '{}': Reference to invalid ConstantPool index {}",

func.name, c_idx

));

}

}

Operand::JumpOffset(offset) => {

let target = (idx as i32) + offset;

if target < 0 || target >= (num_insts as i32) {

return Err(format!(

"Validation error in function '{}': Out of bounds jump offset {} targeting index {}",

func.name, offset, target

));

}

}

_ => {}

}

}

}

}

Ok(())

}