1
1
Fork 0
mirror of https://github.com/azur1s/bobbylisp.git synced 2024-10-16 02:37:40 -05:00

some c backend

This commit is contained in:
Natapat Samutpong 2022-02-24 19:33:14 +07:00
parent 0e992d9324
commit 0e3cd664af
5 changed files with 97 additions and 14 deletions

View file

@ -1,12 +1,9 @@
let foo = if 1 == 1 then
5
else
10
end;
let foo = 1;
let bar = true;
let baz = "qux";
do
print(1);
end;
fun bar a b = a + b;
let baz = bar(34 35);
if (bar == true) then
print(baz);
else
print("quux");
end;

76
src/back/c.rs Normal file
View file

@ -0,0 +1,76 @@
use crate::front::parse::Expr;
pub struct Codegen {
pub emitted: String,
}
impl Codegen {
pub fn new() -> Self {
Self {
emitted: String::new(),
}
}
fn emit(&mut self, s: String) {
self.emitted.push_str(s.as_str());
}
pub fn gen(&mut self, exprs: &[Expr]) {
self.emit("#include <stdio.h>\n#include <stdbool.h>\nint main() {\n".to_string());
for expr in exprs {
self.gen_expr(expr);
}
self.emit("return 0;\n}\n".to_string());
}
fn gen_expr(&mut self, expr: &Expr) {
match expr {
Expr::Let { name, value } => {
match &**value {
Expr::Int(i) => self.emit(format!("int {} = {};\n", name, i)),
Expr::Float(f) => self.emit(format!("double {} = {};\n", name, f)),
Expr::Boolean(b) => self.emit(format!("bool {} = {};\n", name, b)),
Expr::String(s) => self.emit(format!("char *{} = \"{}\";\n", name, s)),
_ => todo!(),
}
},
Expr::Call { name, args } => {
match &**name {
Expr::Ident(func) => {
match func.as_str() {
"print" => {
self.emit(format!("printf({});\n", match &args[0] {
Expr::String(s) => format!("\"{}\"", s),
Expr::Ident(s) => s.to_string(),
_ => todo!(),
}));
},
_ => todo!(),
}
},
_ => todo!(),
}
},
Expr::If { cond, then, else_ } => {
self.emit("if ".to_string());
self.gen_expr(&cond);
self.emit(" {\n".to_string());
self.gen_expr(&then);
self.emit("} else {\n".to_string());
self.gen_expr(&else_);
self.emit("}\n".to_string());
},
Expr::Binary { left, op, right } => {
self.emit("(".to_string());
self.gen_expr(&left);
self.emit(format!(" {} ", op.to_string()));
self.gen_expr(&right);
self.emit(")".to_string());
},
Expr::Ident(s) => self.emit(s.to_string()),
Expr::Boolean(b) => self.emit(format!("{}", b)),
_ => { println!("{:?}", expr); todo!() },
}
}
}

2
src/back/mod.rs Normal file
View file

@ -0,0 +1,2 @@
/// C compiler backend
pub mod c;

View file

@ -26,6 +26,7 @@ pub fn lexer() -> impl Parser<char, Vec<(Token, Span)>, Error = Simple<char>> {
let int = text::int(10)
.map(|s: String| Token::Int(s.parse().unwrap()));
// TODO: this is not working somehow
let float = text::int(10)
.then_ignore(just('.'))
.chain::<char, _, _>(text::digits(10))
@ -315,7 +316,7 @@ impl Expr {
Self::String(x) => out.push_str(&format!("\"{}\"", x)),
Self::Ident(x) => out.push_str(&x),
Self::Unary{ op, expr } => out.push_str(&format!("({} {})", op, expr.to_sexpr())),
Self::Unary{ op, expr } => out.push_str(&format!("({} {})", op, expr.to_sexpr())),
Self::Binary{ op, left, right } => out.push_str(
&format!("({} {} {})", op, left.to_sexpr(), right.to_sexpr())
),
@ -328,7 +329,7 @@ impl Expr {
&format!("(fun {} ({})\n {})", name, args.join(" "), body.to_sexpr())),
Self::If { cond, then, else_ } => out.push_str(
&format!("(if {}\n {}\n {})", cond.to_sexpr(), then.to_sexpr(), else_.to_sexpr())),
&format!("(if {} {} {})", cond.to_sexpr(), then.to_sexpr(), else_.to_sexpr())),
Self::Do { body } => out.push_str(
&format!("(do {})", body.iter().map(|x| x.to_sexpr()).collect::<Vec<_>>().join(" "))),

View file

@ -12,6 +12,10 @@ use args::{Args, Options};
pub mod front;
use front::parse::{lexer, parser};
/// Back-end of the language.
/// Contains code generator.
pub mod back;
fn main() {
let args = Args::parse();
match args.options {
@ -24,7 +28,10 @@ fn main() {
if parse_error.is_empty() {
match ast {
Some(ast) => {
println!("{}", ast.iter().map(|e| e.to_sexpr()).collect::<Vec<String>>().join("\n\n"));
// println!("{}", ast.iter().map(|e| e.to_sexpr()).collect::<Vec<String>>().join("\n\n"));
let mut codegen = back::c::Codegen::new();
codegen.gen(&ast);
print!("{}", codegen.emitted);
},
None => println!("no ast :("),
};