1use gcmodule::Cc;2use jrsonnet_evaluator::{3 error::{Error, LocError},4 gc::TraceBox,5 native::{NativeCallback, NativeCallbackHandler},6 EvaluationState, Val,7};8use jrsonnet_parser::{Param, ParamsDesc};9use std::{10 ffi::{c_void, CStr},11 os::raw::{c_char, c_int},12 path::Path,13 rc::Rc,14};1516type JsonnetNativeCallback = unsafe extern "C" fn(17 ctx: *const c_void,18 argv: *const *const Val,19 success: *mut c_int,20) -> *mut Val;2122#[derive(gcmodule::Trace)]23struct JsonnetNativeCallbackHandler {24 #[skip_trace]25 ctx: *const c_void,26 #[skip_trace]27 cb: JsonnetNativeCallback,28}29impl NativeCallbackHandler for JsonnetNativeCallbackHandler {30 fn call(&self, _from: Rc<Path>, args: &[Val]) -> Result<Val, LocError> {31 let mut n_args = Vec::new();32 for a in args {33 n_args.push(Some(Box::new(a.clone())));34 }35 n_args.push(None);36 let mut success = 1;37 let v = unsafe {38 (self.cb)(39 self.ctx,40 &n_args as *const _ as *const *const Val,41 &mut success,42 )43 };44 let v = unsafe { *Box::from_raw(v) };45 if success == 1 {46 Ok(v)47 } else {48 let e = v.try_cast_str("native error").expect("error msg");49 Err(Error::RuntimeError(e).into())50 }51 }52}535455#[no_mangle]56pub unsafe extern "C" fn jsonnet_native_callback(57 vm: &EvaluationState,58 name: *const c_char,59 cb: JsonnetNativeCallback,60 ctx: *const c_void,61 mut raw_params: *const *const c_char,62) {63 let name = CStr::from_ptr(name).to_str().expect("utf8 name").into();64 let mut params = Vec::new();65 loop {66 if (*raw_params).is_null() {67 break;68 }69 let param = CStr::from_ptr(*raw_params).to_str().expect("not utf8");70 params.push(Param(param.into(), None));71 raw_params = raw_params.offset(1);72 }73 let params = ParamsDesc(Rc::new(params));7475 vm.add_native(76 name,77 Cc::new(NativeCallback::new(78 params,79 TraceBox(Box::new(JsonnetNativeCallbackHandler { ctx, cb })),80 )),81 )82}