bquarkz
30acbf5156
Co-authored-by: Nilton Constantino <nilton.constantino@visma.com> Reviewed-on: #5
76 lines
2.4 KiB
Rust
76 lines
2.4 KiB
Rust
use crate::opcode::OpCode;
|
|
use crate::readwrite::*;
|
|
use std::collections::HashMap;
|
|
|
|
#[derive(Debug, Clone)]
|
|
pub enum Operand {
|
|
U32(u32),
|
|
I32(i32),
|
|
I64(i64),
|
|
F64(f64),
|
|
Bool(bool),
|
|
Label(String),
|
|
}
|
|
|
|
#[derive(Debug, Clone)]
|
|
pub enum Asm {
|
|
Op(OpCode, Vec<Operand>),
|
|
Label(String),
|
|
}
|
|
|
|
pub fn update_pc_by_operand(initial_pc: u32, operands: &Vec<Operand>) -> u32 {
|
|
let mut pcp: u32 = initial_pc;
|
|
for operand in operands {
|
|
match operand {
|
|
Operand::U32(_) | Operand::I32(_) | Operand::Label(_) => pcp += 4,
|
|
Operand::I64(_) | Operand::F64(_) => pcp += 8,
|
|
Operand::Bool(_) => pcp += 1,
|
|
}
|
|
}
|
|
pcp
|
|
}
|
|
|
|
pub fn assemble(instructions: &[Asm]) -> Result<Vec<u8>, String> {
|
|
let mut labels = HashMap::new();
|
|
let mut current_pc = 0u32;
|
|
|
|
// First pass: resolve labels
|
|
for instr in instructions {
|
|
match instr {
|
|
Asm::Label(name) => {
|
|
labels.insert(name.clone(), current_pc);
|
|
}
|
|
Asm::Op(_opcode, operands) => {
|
|
current_pc += 2; // OpCode is u16 (2 bytes)
|
|
current_pc = update_pc_by_operand(current_pc, operands);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Second pass: generate bytes
|
|
let mut rom = Vec::new();
|
|
for instr in instructions {
|
|
match instr {
|
|
Asm::Label(_) => {}
|
|
Asm::Op(opcode, operands) => {
|
|
write_u16_le(&mut rom, *opcode as u16).map_err(|e| e.to_string())?;
|
|
for operand in operands {
|
|
match operand {
|
|
Operand::U32(v) => write_u32_le(&mut rom, *v).map_err(|e| e.to_string())?,
|
|
Operand::I32(v) => write_u32_le(&mut rom, *v as u32).map_err(|e| e.to_string())?,
|
|
Operand::I64(v) => write_i64_le(&mut rom, *v).map_err(|e| e.to_string())?,
|
|
Operand::F64(v) => write_f64_le(&mut rom, *v).map_err(|e| e.to_string())?,
|
|
Operand::Bool(v) => rom.push(if *v { 1 } else { 0 }),
|
|
Operand::Label(name) => {
|
|
let addr = labels.get(name).ok_or(format!("Undefined label: {}", name))?;
|
|
write_u32_le(&mut rom, *addr).map_err(|e| e.to_string())?;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
Ok(rom)
|
|
}
|