1 files changed, 19 insertions, 9 deletions

diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 14bbe65d5..972c84b10 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -7,8 +7,9 @@ use crate::rmeta::{CrateDep, CrateMetadata, CrateNumMap, CrateRoot, MetadataBlob
 use rustc_ast::expand::allocator::{alloc_error_handler_name, global_fn_name, AllocatorKind};
 use rustc_ast::{self as ast, *};
 use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::owned_slice::OwnedSlice;
 use rustc_data_structures::svh::Svh;
-use rustc_data_structures::sync::{FreezeReadGuard, FreezeWriteGuard};
+use rustc_data_structures::sync::{self, FreezeReadGuard, FreezeWriteGuard};
 use rustc_expand::base::SyntaxExtension;
 use rustc_fs_util::try_canonicalize;
 use rustc_hir::def_id::{CrateNum, LocalDefId, StableCrateId, StableCrateIdMap, LOCAL_CRATE};
@@ -16,16 +17,14 @@ use rustc_hir::definitions::Definitions;
 use rustc_index::IndexVec;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{self, CrateType, ExternLocation};
-use rustc_session::cstore::{
-    CrateDepKind, CrateSource, ExternCrate, ExternCrateSource, MetadataLoaderDyn,
-};
+use rustc_session::cstore::{CrateDepKind, CrateSource, ExternCrate, ExternCrateSource};
 use rustc_session::lint;
 use rustc_session::output::validate_crate_name;
 use rustc_session::search_paths::PathKind;
 use rustc_span::edition::Edition;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{Span, DUMMY_SP};
-use rustc_target::spec::{PanicStrategy, TargetTriple};
+use rustc_target::spec::{PanicStrategy, Target, TargetTriple};
 
 use proc_macro::bridge::client::ProcMacro;
 use std::error::Error;
@@ -34,6 +33,17 @@ use std::path::Path;
 use std::time::Duration;
 use std::{cmp, iter};
 
+/// The backend's way to give the crate store access to the metadata in a library.
+/// Note that it returns the raw metadata bytes stored in the library file, whether
+/// it is compressed, uncompressed, some weird mix, etc.
+/// rmeta files are backend independent and not handled here.
+pub trait MetadataLoader {
+    fn get_rlib_metadata(&self, target: &Target, filename: &Path) -> Result<OwnedSlice, String>;
+    fn get_dylib_metadata(&self, target: &Target, filename: &Path) -> Result<OwnedSlice, String>;
+}
+
+pub type MetadataLoaderDyn = dyn MetadataLoader + Send + Sync + sync::DynSend + sync::DynSync;
+
 pub struct CStore {
     metadata_loader: Box<MetadataLoaderDyn>,
 
@@ -257,7 +267,7 @@ impl CStore {
             let unused_externs =
                 self.unused_externs.iter().map(|ident| ident.to_ident_string()).collect::<Vec<_>>();
             let unused_externs = unused_externs.iter().map(String::as_str).collect::<Vec<&str>>();
-            tcx.sess.parse_sess.span_diagnostic.emit_unused_externs(
+            tcx.sess.dcx().emit_unused_externs(
                 level,
                 json_unused_externs.is_loud(),
                 &unused_externs,
@@ -427,7 +437,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
 
         let crate_metadata = CrateMetadata::new(
             self.sess,
-            &self.cstore,
+            self.cstore,
             metadata,
             crate_root,
             raw_proc_macros,
@@ -515,7 +525,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
             Err(err) => {
                 let missing_core =
                     self.maybe_resolve_crate(sym::core, CrateDepKind::Explicit, None).is_err();
-                err.report(&self.sess, span, missing_core);
+                err.report(self.sess, span, missing_core);
                 None
             }
         }
@@ -987,7 +997,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
 
         self.report_unused_deps(krate);
 
-        info!("{:?}", CrateDump(&self.cstore));
+        info!("{:?}", CrateDump(self.cstore));
     }
 
     pub fn process_extern_crate(