Big Rewrite

compiler/src/libqjs/mod.rs

@@ -0,0 +1,53 @@
+mod ffi;
+pub mod parse;
+
+use std::ffi::{CStr, CString};
+
+use parse::QuickJSBinary;
+
+pub fn compile(src: &[u8], filename: &str) -> QuickJSBinary {
+    unsafe {
+        let filename = CString::new(filename).unwrap();
+
+        let rt = ffi::JS_NewRuntime();
+        let ctx = ffi::JS_NewContext(rt);
+
+        let obj = ffi::JS_Eval(
+            ctx,
+            src.as_ptr(),
+            src.len(),
+            filename.as_ptr().cast(),
+            ffi::JS_EVAL_FLAG_COMPILE_ONLY | ffi::JS_EVAL_TYPE_MODULE,
+        );
+
+        assert!(obj.tag != ffi::JS_TAG_EXCEPTION, "{}", get_exception(ctx));
+
+        let mut len = 0;
+        let buf = ffi::JS_WriteObject(ctx, &mut len, obj, ffi::JS_WRITE_OBJ_BYTECODE);
+        ffi::JS_FreeValue(ctx, obj);
+
+        assert!(!buf.is_null());
+        let bytes = std::slice::from_raw_parts(buf, len).to_vec();
+
+        // TODO: Are we sure other cleanup is not necessary?
+        ffi::JS_FreeContext(ctx);
+        ffi::JS_FreeRuntime(rt);
+
+        QuickJSBinary::parse(&bytes).unwrap().1
+    }
+}
+
+fn get_exception(ctx: *mut ffi::JSContext) -> String {
+    unsafe {
+        let err = ffi::JS_GetException(ctx);
+        let text = ffi::JS_ToCStringLen2(ctx, std::ptr::null_mut(), err, false);
+
+        let message = if text.is_null() {
+            "quickjs raised an exception it could not describe".to_string()
+        } else {
+            CStr::from_ptr(text).to_string_lossy().into_owned()
+        };
+
+        message
+    }
+}