feat: add a backed using cranelift ir and codegen crates

src/main.rs

@@ -1,17 +1,34 @@
-use std::{env::args, fs::read_to_string, process::exit};
+use std::{fs::read_to_string, path::PathBuf, process::exit};
+
+use clap::Parser as ClapParser;
 
 use crate::frontend::parser::Parser;
 use crate::frontend::sema::Sema;
 
+pub mod backend;
 pub mod frontend;
 
-fn main() {
-    let Some(path) = args().nth(1) else {
-        eprintln!("usage: compiler <file>");
-        exit(1);
-    };
+use crate::backend::cranelift::CraneliftBackend;
 
-    let content = read_to_string(&path).unwrap_or_else(|err| {
+#[derive(ClapParser)]
+#[command(version, about, long_about = None)]
+struct Cli {
+    /// The input source file to compile
+    input: String,
+
+    /// The output file path
+    #[arg(short, long)]
+    output: Option<String>,
+
+    /// Emit Cranelift IR instead of an object file
+    #[arg(long)]
+    emit_ir: bool,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    let content = read_to_string(&cli.input).unwrap_or_else(|err| {
         eprintln!("error: failed to read source file ({:?})", err);
         exit(1);
     });
@@ -38,5 +55,24 @@ fn main() {
         exit(1);
     }
 
-    println!("{:#?}", typed_module);
+    let backend = CraneliftBackend::new();
+    let (ir, obj_bytes) = backend.compile_module(&typed_module);
+
+    if cli.emit_ir {
+        println!("{}", ir);
+    } else {
+        let output_path = cli.output.unwrap_or_else(|| {
+            PathBuf::from(&cli.input)
+                .with_extension("o")
+                .to_string_lossy()
+                .into_owned()
+        });
+
+        std::fs::write(&output_path, obj_bytes).unwrap_or_else(|err| {
+            eprintln!("error: failed to write object file: {:?}", err);
+            exit(1);
+        });
+
+        println!("Generated object file: {}", output_path);
+    }
 }