diff --git a/src/librustc_incremental/Cargo.toml b/src/librustc_incremental/Cargo.toml
index b8519ee1ab1..10b448b7fec 100644
--- a/src/librustc_incremental/Cargo.toml
+++ b/src/librustc_incremental/Cargo.toml
@@ -2,6 +2,7 @@
 authors = ["The Rust Project Developers"]
 name = "rustc_incremental"
 version = "0.0.0"
+edition = "2018"
 
 [lib]
 name = "rustc_incremental"
diff --git a/src/librustc_incremental/assert_dep_graph.rs b/src/librustc_incremental/assert_dep_graph.rs
index 57ab48493fa..b715a32cb05 100644
--- a/src/librustc_incremental/assert_dep_graph.rs
+++ b/src/librustc_incremental/assert_dep_graph.rs
@@ -217,7 +217,7 @@ fn check_paths<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     }
 }
 
-fn dump_graph(tcx: TyCtxt) {
+fn dump_graph(tcx: TyCtxt<'_, '_, '_>) {
     let path: String = env::var("RUST_DEP_GRAPH").unwrap_or_else(|_| "dep_graph".to_string());
     let query = tcx.dep_graph.query();
 
@@ -261,11 +261,11 @@ pub struct GraphvizDepGraph<'q>(FxHashSet<&'q DepNode>,
 impl<'a, 'tcx, 'q> dot::GraphWalk<'a> for GraphvizDepGraph<'q> {
     type Node = &'q DepNode;
     type Edge = (&'q DepNode, &'q DepNode);
-    fn nodes(&self) -> dot::Nodes<&'q DepNode> {
+    fn nodes(&self) -> dot::Nodes<'_, &'q DepNode> {
         let nodes: Vec<_> = self.0.iter().cloned().collect();
         nodes.into()
     }
-    fn edges(&self) -> dot::Edges<(&'q DepNode, &'q DepNode)> {
+    fn edges(&self) -> dot::Edges<'_, (&'q DepNode, &'q DepNode)> {
         self.1[..].into()
     }
     fn source(&self, edge: &(&'q DepNode, &'q DepNode)) -> &'q DepNode {
@@ -279,10 +279,10 @@ impl<'a, 'tcx, 'q> dot::GraphWalk<'a> for GraphvizDepGraph<'q> {
 impl<'a, 'tcx, 'q> dot::Labeller<'a> for GraphvizDepGraph<'q> {
     type Node = &'q DepNode;
     type Edge = (&'q DepNode, &'q DepNode);
-    fn graph_id(&self) -> dot::Id {
+    fn graph_id(&self) -> dot::Id<'_> {
         dot::Id::new("DependencyGraph").unwrap()
     }
-    fn node_id(&self, n: &&'q DepNode) -> dot::Id {
+    fn node_id(&self, n: &&'q DepNode) -> dot::Id<'_> {
         let s: String =
             format!("{:?}", n).chars()
                               .map(|c| if c == '_' || c.is_alphanumeric() { c } else { '_' })
@@ -290,7 +290,7 @@ impl<'a, 'tcx, 'q> dot::Labeller<'a> for GraphvizDepGraph<'q> {
         debug!("n={:?} s={:?}", n, s);
         dot::Id::new(s).unwrap()
     }
-    fn node_label(&self, n: &&'q DepNode) -> dot::LabelText {
+    fn node_label(&self, n: &&'q DepNode) -> dot::LabelText<'_> {
         dot::LabelText::label(format!("{:?}", n))
     }
 }
diff --git a/src/librustc_incremental/lib.rs b/src/librustc_incremental/lib.rs
index ae2e6e0b94c..1fc51c27311 100644
--- a/src/librustc_incremental/lib.rs
+++ b/src/librustc_incremental/lib.rs
@@ -9,16 +9,13 @@
 
 #![recursion_limit="256"]
 
-extern crate graphviz;
+#![deny(rust_2018_idioms)]
+
 #[macro_use] extern crate rustc;
-extern crate rustc_data_structures;
-extern crate serialize as rustc_serialize;
-extern crate rand;
-extern crate rustc_fs_util;
+#[allow(unused_extern_crates)]
+extern crate serialize as rustc_serialize; // used by deriving
 
 #[macro_use] extern crate log;
-extern crate syntax;
-extern crate syntax_pos;
 
 mod assert_dep_graph;
 pub mod assert_module_sources;
diff --git a/src/librustc_incremental/persist/dirty_clean.rs b/src/librustc_incremental/persist/dirty_clean.rs
index 3ff4d2ec38d..9b52199465b 100644
--- a/src/librustc_incremental/persist/dirty_clean.rs
+++ b/src/librustc_incremental/persist/dirty_clean.rs
@@ -538,7 +538,7 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for DirtyCleanVisitor<'a, 'tcx> {
 ///
 /// Also make sure that the `label` and `except` fields do not
 /// both exist.
-fn check_config(tcx: TyCtxt, attr: &Attribute) -> bool {
+fn check_config(tcx: TyCtxt<'_, '_, '_>, attr: &Attribute) -> bool {
     debug!("check_config(attr={:?})", attr);
     let config = &tcx.sess.parse_sess.config;
     debug!("check_config: config={:?}", config);
@@ -573,7 +573,7 @@ fn check_config(tcx: TyCtxt, attr: &Attribute) -> bool {
     }
 }
 
-fn expect_associated_value(tcx: TyCtxt, item: &NestedMetaItem) -> ast::Name {
+fn expect_associated_value(tcx: TyCtxt<'_, '_, '_>, item: &NestedMetaItem) -> ast::Name {
     if let Some(value) = item.value_str() {
         value
     } else {
diff --git a/src/librustc_incremental/persist/load.rs b/src/librustc_incremental/persist/load.rs
index f330de71918..ecf8bc4a880 100644
--- a/src/librustc_incremental/persist/load.rs
+++ b/src/librustc_incremental/persist/load.rs
@@ -9,7 +9,6 @@ use rustc::util::common::time_ext;
 use rustc_serialize::Decodable as RustcDecodable;
 use rustc_serialize::opaque::Decoder;
 use std::path::Path;
-use std;
 
 use super::data::*;
 use super::fs::*;
diff --git a/src/librustc_incremental/persist/mod.rs b/src/librustc_incremental/persist/mod.rs
index bd59f24d04e..3aad4f5abb8 100644
--- a/src/librustc_incremental/persist/mod.rs
+++ b/src/librustc_incremental/persist/mod.rs
@@ -10,16 +10,16 @@ mod save;
 mod work_product;
 mod file_format;
 
-pub use self::fs::finalize_session_directory;
-pub use self::fs::garbage_collect_session_directories;
-pub use self::fs::in_incr_comp_dir;
-pub use self::fs::in_incr_comp_dir_sess;
-pub use self::fs::prepare_session_directory;
-pub use self::load::dep_graph_tcx_init;
-pub use self::load::load_dep_graph;
-pub use self::load::load_query_result_cache;
-pub use self::load::LoadResult;
-pub use self::save::save_dep_graph;
-pub use self::save::save_work_product_index;
-pub use self::work_product::copy_cgu_workproducts_to_incr_comp_cache_dir;
-pub use self::work_product::delete_workproduct_files;
+pub use fs::finalize_session_directory;
+pub use fs::garbage_collect_session_directories;
+pub use fs::in_incr_comp_dir;
+pub use fs::in_incr_comp_dir_sess;
+pub use fs::prepare_session_directory;
+pub use load::dep_graph_tcx_init;
+pub use load::load_dep_graph;
+pub use load::load_query_result_cache;
+pub use load::LoadResult;
+pub use save::save_dep_graph;
+pub use save::save_work_product_index;
+pub use work_product::copy_cgu_workproducts_to_incr_comp_cache_dir;
+pub use work_product::delete_workproduct_files;
diff --git a/src/librustc_incremental/persist/save.rs b/src/librustc_incremental/persist/save.rs
index 6a7553b3882..34fe2f1c25d 100644
--- a/src/librustc_incremental/persist/save.rs
+++ b/src/librustc_incremental/persist/save.rs
@@ -129,7 +129,7 @@ fn save_in<F>(sess: &Session, path_buf: PathBuf, encode: F)
     }
 }
 
-fn encode_dep_graph(tcx: TyCtxt,
+fn encode_dep_graph(tcx: TyCtxt<'_, '_, '_>,
                     encoder: &mut Encoder) {
     // First encode the commandline arguments hash
     tcx.sess.opts.dep_tracking_hash().encode(encoder).unwrap();
@@ -234,7 +234,7 @@ fn encode_work_product_index(work_products: &FxHashMap<WorkProductId, WorkProduc
     serialized_products.encode(encoder).unwrap();
 }
 
-fn encode_query_cache(tcx: TyCtxt,
+fn encode_query_cache(tcx: TyCtxt<'_, '_, '_>,
                       encoder: &mut Encoder) {
     time(tcx.sess, "serialize query result cache", || {
         tcx.serialize_query_result_cache(encoder).unwrap();
diff --git a/src/librustc_incremental/persist/work_product.rs b/src/librustc_incremental/persist/work_product.rs
index 535f6930aa3..3495b27c5eb 100644
--- a/src/librustc_incremental/persist/work_product.rs
+++ b/src/librustc_incremental/persist/work_product.rs
@@ -1,6 +1,6 @@
 //! This module contains files for saving intermediate work-products.
 
-use persist::fs::*;
+use crate::persist::fs::*;
 use rustc::dep_graph::{WorkProduct, WorkProductId, WorkProductFileKind};
 use rustc::session::Session;
 use rustc_fs_util::link_or_copy;