[quickjs][oden][oden-js] Source maps

The worst support but it should cost very little if nobody is using
them (psst we're using them)

oden-js/src/module/loader.rs

@@ -1,6 +1,5 @@
 use super::ModuleRef;
-use crate::{throw_error, ContextRef, Error, Result};
-use oden_js_sys as sys;
+use crate::{Atom, AtomRef, ContextRef, Error, Result};
 use std::path::Path;
 
 pub enum ModuleSource<'a> {
@@ -9,7 +8,22 @@ pub enum ModuleSource<'a> {
 }
 
 pub trait ModuleLoader {
-    fn load(&self, context: &ContextRef, name: &str) -> Result<ModuleSource>;
+    fn load<'a>(&mut self, context: &'a ContextRef, name: &str) -> Result<ModuleSource<'a>>;
+
+    // Return true if this loader also supports source maps, otherwise false.
+    // NOTE: This must return `true` if you want to have a non-trivial
+    //       implementation of `map_source`; if this returns `false` (the
+    //       default) then your object will never even receive a map_source
+    //       call.
+    fn support_source_map(&self) -> bool {
+        false
+    }
+
+    // Map a given file/line pair to the source file/line pair. This is only
+    // called if `support_source_map` returns true.
+    fn map_source(&self, context: &ContextRef, file: &AtomRef, line: i32) -> Result<(Atom, i32)> {
+        Ok((file.dup(context), line))
+    }
 }
 
 pub struct DefaultModuleLoader {}
@@ -21,7 +35,7 @@ impl DefaultModuleLoader {
 }
 
 impl ModuleLoader for DefaultModuleLoader {
-    fn load(&self, _context: &ContextRef, name: &str) -> Result<ModuleSource> {
+    fn load<'a>(&mut self, _context: &'a ContextRef, name: &str) -> Result<ModuleSource<'a>> {
         // Attempt to open the file.
         let path = Path::new(name);
         match std::fs::read_to_string(path) {
@@ -30,24 +44,3 @@ impl ModuleLoader for DefaultModuleLoader {
         }
     }
 }
-
-pub(crate) fn load_module(
-    context: &ContextRef,
-    name: &str,
-    loader: &Box<dyn ModuleLoader>,
-) -> *mut sys::JSModuleDef {
-    match loader.load(context, name) {
-        Ok(ModuleSource::Native(native)) => native.module,
-        Ok(ModuleSource::JavaScript(js)) => match context.eval_module(&js, name) {
-            Ok(v) => v.module,
-            Err(e) => {
-                throw_error(context, e);
-                return std::ptr::null_mut();
-            }
-        },
-        Err(e) => {
-            throw_error(context, e);
-            return std::ptr::null_mut();
-        }
-    }
-}

oden-js/src/module/mod.rs

@@ -8,7 +8,7 @@ pub mod native;
 
 #[derive(Debug, Clone)]
 pub struct ModuleRef {
-    module: *mut sys::JSModuleDef,
+    pub(crate) module: *mut sys::JSModuleDef,
 }
 
 impl ModuleRef {