Updates for build system integration

- Use a config file as input to `dol split`
- Add depfile output
- Adjust splits config writing

src/obj/mod.rs

@@ -764,6 +764,12 @@ impl ObjInfo {
         self.splits.entry(address).or_default().push(split);
         Ok(())
     }
+
+    pub fn is_unit_autogenerated(&self, unit: &str) -> bool {
+        self.splits_for_range(..)
+            .filter(|(_, split)| split.unit == unit)
+            .all(|(_, split)| split.autogenerated)
+    }
 }
 
 impl ObjSection {

src/obj/split.rs

@@ -402,8 +402,7 @@ fn resolve_link_order(obj: &ObjInfo) -> Result<Vec<String>> {
         unit_to_index_map.insert(split.unit.clone(), NodeIndex::new(0));
     }
     for (unit, index) in unit_to_index_map.iter_mut() {
-        let new_index = graph.add_node(unit.clone());
-        *index = new_index;
+        *index = graph.add_node(unit.clone());
     }
 
     for section in &obj.sections {