diff --git a/src/allocator.rs b/src/allocator.rs
index 2474e014670..ba1eda7148f 100644
--- a/src/allocator.rs
+++ b/src/allocator.rs
@@ -63,7 +63,7 @@ pub fn codegen(module: &mut Module<impl Backend + 'static>, kind: AllocatorKind)
         ctx.func = Function::with_name_signature(ExternalName::user(0, 0), sig.clone());
         {
             let mut func_ctx = FunctionBuilderContext::new();
-            let mut bcx: FunctionBuilder = FunctionBuilder::new(&mut ctx.func, &mut func_ctx);
+            let mut bcx = FunctionBuilder::new(&mut ctx.func, &mut func_ctx);
 
             let ebb = bcx.create_ebb();
             bcx.switch_to_block(ebb);
diff --git a/src/analyze.rs b/src/analyze.rs
index 025fc1fecba..d3cbe93b722 100644
--- a/src/analyze.rs
+++ b/src/analyze.rs
@@ -2,7 +2,7 @@ use crate::prelude::*;
 
 use rustc::mir::StatementKind::*;
 
-bitflags! {
+bitflags::bitflags! {
     pub struct Flags: u8 {
         const NOT_SSA = 0b00000001;
     }
diff --git a/src/base.rs b/src/base.rs
index a4645ea7e01..5607df48838 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -74,7 +74,7 @@ fn trans_fn<'a, 'tcx: 'a>(
     // Step 3. Make FunctionBuilder
     let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
     let mut func_ctx = FunctionBuilderContext::new();
-    let mut bcx: FunctionBuilder = FunctionBuilder::new(&mut func, &mut func_ctx);
+    let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
 
     // Step 4. Predefine ebb's
     let start_ebb = bcx.create_ebb();
diff --git a/src/common.rs b/src/common.rs
index e3f13260e8b..02e04f0d3eb 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -603,7 +603,7 @@ pub fn clif_intcast<'a, 'tcx: 'a>(
     }
 }
 
-pub struct FunctionCx<'a, 'tcx: 'a, B: Backend + 'a> {
+pub struct FunctionCx<'a, 'tcx: 'a, B: Backend> {
     pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
     pub module: &'a mut Module<B>,
     pub pointer_type: Type, // Cached from module
diff --git a/src/lib.rs b/src/lib.rs
index 5b25861838e..9f81cebccaf 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,32 +7,17 @@
 )]
 #![allow(intra_doc_link_resolution_failure)]
 
-extern crate byteorder;
 extern crate syntax;
-#[macro_use]
 extern crate rustc;
 extern crate rustc_allocator;
 extern crate rustc_codegen_utils;
 extern crate rustc_incremental;
 extern crate rustc_mir;
 extern crate rustc_target;
-#[macro_use]
 extern crate rustc_data_structures;
 extern crate rustc_fs_util;
-#[macro_use]
 extern crate log;
 
-extern crate ar;
-#[macro_use]
-extern crate bitflags;
-extern crate faerie;
-//extern crate goblin;
-extern crate cranelift;
-extern crate cranelift_faerie;
-extern crate cranelift_module;
-extern crate cranelift_simplejit;
-extern crate target_lexicon;
-
 use std::any::Any;
 use std::fs::File;
 use std::sync::mpsc;
@@ -84,6 +69,7 @@ mod prelude {
     pub use syntax::ast::{FloatTy, IntTy, UintTy};
     pub use syntax::source_map::DUMMY_SP;
 
+    pub use rustc::bug;
     pub use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
     pub use rustc::mir::{self, interpret::AllocId, *};
     pub use rustc::session::{
@@ -291,7 +277,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
         }
     }
 
-    fn metadata_loader(&self) -> Box<MetadataLoader + Sync> {
+    fn metadata_loader(&self) -> Box<dyn MetadataLoader + Sync> {
         Box::new(crate::metadata::CraneliftMetadataLoader)
     }
 
@@ -308,8 +294,8 @@ impl CodegenBackend for CraneliftCodegenBackend {
     fn codegen_crate<'a, 'tcx>(
         &self,
         tcx: TyCtxt<'a, 'tcx, 'tcx>,
-        _rx: mpsc::Receiver<Box<Any + Send>>,
-    ) -> Box<Any> {
+        _rx: mpsc::Receiver<Box<dyn Any + Send>>,
+    ) -> Box<dyn Any> {
         if !tcx.sess.crate_types.get().contains(&CrateType::Executable)
             && std::env::var("SHOULD_RUN").is_ok()
         {
@@ -436,7 +422,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
 
     fn join_codegen_and_link(
         &self,
-        res: Box<Any>,
+        res: Box<dyn Any>,
         sess: &Session,
         _dep_graph: &DepGraph,
         outputs: &OutputFilenames,
@@ -512,6 +498,6 @@ fn save_incremental<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
 
 /// This is the entrypoint for a hot plugged rustc_codegen_cranelift
 #[no_mangle]
-pub fn __rustc_codegen_backend() -> Box<CodegenBackend> {
+pub fn __rustc_codegen_backend() -> Box<dyn CodegenBackend> {
     Box::new(CraneliftCodegenBackend)
 }
diff --git a/src/link_copied.rs b/src/link_copied.rs
index 986fe71e906..2bec64612aa 100644
--- a/src/link_copied.rs
+++ b/src/link_copied.rs
@@ -9,6 +9,7 @@ use std::path::{Path, PathBuf};
 use std::process::{Output, Stdio};
 
 use cc::windows_registry;
+use log::info;
 
 use rustc::middle::cstore::{NativeLibrary, NativeLibraryKind};
 use rustc::middle::dependency_format::Linkage;
diff --git a/src/metadata.rs b/src/metadata.rs
index c70fdba35d8..c9cdb44d87d 100644
--- a/src/metadata.rs
+++ b/src/metadata.rs
@@ -1,5 +1,6 @@
 use rustc::middle::cstore::MetadataLoader;
 use rustc_data_structures::owning_ref::{self, OwningRef};
+use rustc_data_structures::rustc_erase_owner;
 use std::fs::File;
 use std::path::Path;