rustc: Add a convenience alias for dyn MetadataLoader + Sync

src/librustc/middle/cstore.rs

@@ -191,6 +191,8 @@ pub trait MetadataLoader {
                           -> Result<MetadataRef, String>;
 }
 
+pub type MetadataLoaderDyn = dyn MetadataLoader + Sync;
+
 /// A store of Rust crates, through which their metadata can be accessed.
 ///
 /// Note that this trait should probably not be expanding today. All new

src/librustc_codegen_llvm/lib.rs

@@ -56,7 +56,7 @@ use std::sync::Arc;
 use std::ffi::CStr;
 
 use rustc::dep_graph::DepGraph;
-use rustc::middle::cstore::{EncodedMetadata, MetadataLoader};
+use rustc::middle::cstore::{EncodedMetadata, MetadataLoaderDyn};
 use rustc::session::Session;
 use rustc::session::config::{OutputFilenames, OutputType, PrintRequest, OptLevel};
 use rustc::ty::{self, TyCtxt};
@@ -260,7 +260,7 @@ impl CodegenBackend for LlvmCodegenBackend {
         target_features(sess)
     }
 
-    fn metadata_loader(&self) -> Box<dyn MetadataLoader + Sync> {
+    fn metadata_loader(&self) -> Box<MetadataLoaderDyn> {
         box metadata::LlvmMetadataLoader
     }
 

src/librustc_codegen_utils/codegen_backend.rs

@@ -14,7 +14,7 @@ use rustc::util::common::ErrorReported;
 use rustc::session::config::{OutputFilenames, PrintRequest};
 use rustc::ty::TyCtxt;
 use rustc::ty::query::Providers;
-use rustc::middle::cstore::{EncodedMetadata, MetadataLoader};
+use rustc::middle::cstore::{EncodedMetadata, MetadataLoaderDyn};
 use rustc::dep_graph::DepGraph;
 
 pub use rustc_data_structures::sync::MetadataRef;
@@ -26,7 +26,7 @@ pub trait CodegenBackend {
     fn print_passes(&self) {}
     fn print_version(&self) {}
 
-    fn metadata_loader(&self) -> Box<dyn MetadataLoader + Sync>;
+    fn metadata_loader(&self) -> Box<MetadataLoaderDyn>;
     fn provide(&self, _providers: &mut Providers<'_>);
     fn provide_extern(&self, _providers: &mut Providers<'_>);
     fn codegen_crate<'tcx>(

src/librustc_metadata/cstore.rs

@@ -5,7 +5,7 @@ use crate::schema;
 use rustc::dep_graph::DepNodeIndex;
 use rustc::hir::def_id::{CrateNum, DefIndex};
 use rustc::hir::map::definitions::DefPathTable;
-use rustc::middle::cstore::{CrateSource, DepKind, ExternCrate, MetadataLoader};
+use rustc::middle::cstore::{CrateSource, DepKind, ExternCrate, MetadataLoaderDyn};
 use rustc::mir::interpret::AllocDecodingState;
 use rustc_index::vec::IndexVec;
 use rustc::util::nodemap::FxHashMap;
@@ -96,7 +96,7 @@ pub struct CrateMetadata {
 
 pub struct CStore {
     metas: RwLock<IndexVec<CrateNum, Option<Lrc<CrateMetadata>>>>,
-    crate metadata_loader: Box<dyn MetadataLoader + Sync>,
+    crate metadata_loader: Box<MetadataLoaderDyn>,
 }
 
 pub enum LoadedMacro {
@@ -105,7 +105,7 @@ pub enum LoadedMacro {
 }
 
 impl CStore {
-    pub fn new(metadata_loader: Box<dyn MetadataLoader + Sync>) -> CStore {
+    pub fn new(metadata_loader: Box<MetadataLoaderDyn>) -> CStore {
         CStore {
             // We add an empty entry for LOCAL_CRATE (which maps to zero) in
             // order to make array indices in `metas` match with the

src/test/run-make-fulldeps/hotplug_codegen_backend/the_backend.rs

@@ -9,14 +9,14 @@ extern crate rustc_target;
 extern crate rustc_driver;
 
 use std::any::Any;
-use std::sync::{Arc, mpsc};
+use std::sync::Arc;
 use std::path::Path;
 use syntax::symbol::Symbol;
 use rustc::session::Session;
 use rustc::session::config::OutputFilenames;
 use rustc::ty::TyCtxt;
 use rustc::ty::query::Providers;
-use rustc::middle::cstore::{EncodedMetadata, MetadataLoader};
+use rustc::middle::cstore::{EncodedMetadata, MetadataLoader, MetadataLoaderDyn};
 use rustc::dep_graph::DepGraph;
 use rustc::util::common::ErrorReported;
 use rustc_codegen_utils::codegen_backend::CodegenBackend;
@@ -41,7 +41,7 @@ impl MetadataLoader for NoLlvmMetadataLoader {
 struct TheBackend;
 
 impl CodegenBackend for TheBackend {
-    fn metadata_loader(&self) -> Box<dyn MetadataLoader + Sync> {
+    fn metadata_loader(&self) -> Box<MetadataLoaderDyn> {
         Box::new(NoLlvmMetadataLoader)
     }