holey-bytes/hblang/build.rs
2024-07-08 07:22:53 +02:00

125 lines
3.6 KiB
Rust

#![feature(iter_next_chunk)]
use std::fmt::Write;
fn main() -> Result<(), Box<dyn std::error::Error>> {
println!("cargo:rerun-if-changed=build.rs");
println!("cargo:rerun-if-changed=../hbbytecode/instructions.in");
let mut generated = String::new();
writeln!(generated, "#![allow(dead_code)] #![allow(clippy::upper_case_acronyms)]")?;
gen_max_size(&mut generated)?;
gen_encodes(&mut generated)?;
gen_structs(&mut generated)?;
gen_name_list(&mut generated)?;
std::fs::write("src/instrs.rs", generated)?;
Ok(())
}
fn gen_name_list(generated: &mut String) -> Result<(), Box<dyn std::error::Error>> {
writeln!(generated, "pub const NAMES: [&str; {}] = [", instructions().count())?;
for [_, name, _, _] in instructions() {
writeln!(generated, " \"{}\",", name.to_lowercase())?;
}
writeln!(generated, "];")?;
Ok(())
}
fn gen_max_size(generated: &mut String) -> Result<(), Box<dyn std::error::Error>> {
let max = instructions()
.map(|[_, _, ty, _]| {
if ty == "N" {
1
} else {
iter_args(ty).map(|(_, c)| arg_to_width(c)).sum::<usize>() + 1
}
})
.max()
.unwrap();
writeln!(generated, "pub const MAX_SIZE: usize = {};", max)?;
Ok(())
}
fn gen_encodes(generated: &mut String) -> Result<(), Box<dyn std::error::Error>> {
for [op, name, ty, doc] in instructions() {
writeln!(generated, "/// {}", doc.trim_matches('"'))?;
let name = name.to_lowercase();
let args = comma_sep(
iter_args(ty).map(|(i, c)| format!("{}{i}: {}", arg_to_name(c), arg_to_type(c))),
);
writeln!(generated, "pub fn {name}({args}) -> (usize, [u8; MAX_SIZE]) {{")?;
let arg_names = comma_sep(iter_args(ty).map(|(i, c)| format!("{}{i}", arg_to_name(c))));
writeln!(generated, " unsafe {{ crate::encode({ty}({op}, {arg_names})) }}")?;
writeln!(generated, "}}")?;
}
Ok(())
}
fn gen_structs(generated: &mut String) -> Result<(), Box<dyn std::error::Error>> {
let mut seen = std::collections::HashSet::new();
for [_, _, ty, _] in instructions() {
if !seen.insert(ty) {
continue;
}
let types = comma_sep(iter_args(ty).map(|(_, c)| arg_to_type(c).to_string()));
writeln!(generated, "#[repr(packed)] pub struct {ty}(u8, {types});")?;
}
Ok(())
}
fn comma_sep(items: impl Iterator<Item = String>) -> String {
items.map(|item| item.to_string()).collect::<Vec<_>>().join(", ")
}
fn instructions() -> impl Iterator<Item = [&'static str; 4]> {
include_str!("../hbbytecode/instructions.in")
.lines()
.filter_map(|line| line.strip_suffix(';'))
.map(|line| line.splitn(4, ',').map(str::trim).next_chunk().unwrap())
}
fn arg_to_type(arg: char) -> &'static str {
match arg {
'R' | 'B' => "u8",
'H' => "u16",
'W' => "u32",
'D' | 'A' => "u64",
'P' => "i16",
'O' => "i32",
_ => panic!("unknown type: {}", arg),
}
}
fn arg_to_width(arg: char) -> usize {
match arg {
'R' | 'B' => 1,
'H' => 2,
'W' => 4,
'D' | 'A' => 8,
'P' => 2,
'O' => 4,
_ => panic!("unknown type: {}", arg),
}
}
fn arg_to_name(arg: char) -> &'static str {
match arg {
'R' => "reg",
'B' | 'H' | 'W' | 'D' => "imm",
'P' | 'O' => "offset",
'A' => "addr",
_ => panic!("unknown type: {}", arg),
}
}
fn iter_args(ty: &'static str) -> impl Iterator<Item = (usize, char)> {
ty.chars().enumerate().filter(|(_, c)| *c != 'N')
}