diff --git a/ipc/codegen/src/codegen.rs b/ipc/codegen/src/codegen.rs
index ebd2bb361..85ea86f16 100644
--- a/ipc/codegen/src/codegen.rs
+++ b/ipc/codegen/src/codegen.rs
@@ -702,9 +702,10 @@ fn implement_interface(
 	}
 
 	let all_tys = collect_tys(
-		cx,
-		builder,
-		&method_signatures.iter().map(|&(_, signature)| signature).collect::<Vec<&MethodSig>>());
+		&method_signatures
+			.iter()
+			.map(|&(_, signature)| signature)
+			.collect::<Vec<&MethodSig>>());
 
 	let replacements = typegen::match_unknown_tys(cx, builder, &all_tys, push);
 
diff --git a/ipc/codegen/src/typegen.rs b/ipc/codegen/src/typegen.rs
index e339b6788..6e09c9fe6 100644
--- a/ipc/codegen/src/typegen.rs
+++ b/ipc/codegen/src/typegen.rs
@@ -23,7 +23,6 @@ use syntax::ast::{
 };
 
 use syntax::ast;
-use syntax::codemap::Span;
 use syntax::ext::base::{Annotatable, ExtCtxt};
 use syntax::ext::build::AstBuilder;
 use syntax::ptr::P;
@@ -31,13 +30,12 @@ use syntax::ptr::P;
 use std::collections::{HashMap, HashSet};
 use std::ops::Deref;
 
-fn is_new_entry(builder: &aster::AstBuilder, path: &Path) -> Option<String> {
+fn is_new_entry(path: &Path) -> Option<String> {
 	let known = {
 		if path.segments.len() > 1 {
 			false
 		} else {
 			let ident = format!("{}", path.segments[0].identifier.name.as_str());
-
 			ident == "u32"       ||
 			ident == "u64"       ||
 			ident == "usize"     ||
@@ -52,14 +50,6 @@ fn is_new_entry(builder: &aster::AstBuilder, path: &Path) -> Option<String> {
 	else { Some(::syntax::print::pprust::path_to_string(path)) }
 }
 
-fn path_str(path: &Path) -> String {
-	let mut res: String = "_".to_owned();
-	for segment in path.segments.iter() {
-		res.push_str(&format!("{}_", segment.identifier.name.as_str()));
-	}
-	res
-}
-
 pub fn argument_replacement(
 	builder: &aster::AstBuilder,
 	replacements: &HashMap<String, P<Ty>>,
@@ -219,7 +209,7 @@ pub fn match_unknown_tys(
 					continue;
 				}
 
-				match is_new_entry(builder, path) {
+				match is_new_entry(path) {
 					Some(old_path) => {
 						if hash_map.get(&old_path).is_some() {
 							continue;