link: rely on the default metadata loader.

Author: eddyb

crates/rustc_codegen_spirv/src/lib.rs

@@ -167,10 +167,9 @@ use rustc_codegen_ssa::traits::{
 };
 use rustc_codegen_ssa::{CodegenResults, CompiledModule, ModuleCodegen, ModuleKind};
 use rustc_data_structures::fx::FxHashMap;
-use rustc_data_structures::sync::MetadataRef;
 use rustc_errors::{ErrorReported, FatalError, Handler};
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
-use rustc_middle::middle::cstore::{EncodedMetadata, MetadataLoader, MetadataLoaderDyn};
+use rustc_middle::middle::cstore::EncodedMetadata;
 use rustc_middle::mir::mono::{Linkage, MonoItem, Visibility};
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{self, query, DefIdTree, Instance, InstanceDef, TyCtxt};
@@ -262,18 +261,6 @@ impl ThinBufferMethods for SpirvThinBuffer {
     }
 }
 
-struct SpirvMetadataLoader;
-
-impl MetadataLoader for SpirvMetadataLoader {
-    fn get_rlib_metadata(&self, _: &Target, path: &Path) -> Result<MetadataRef, String> {
-        link::read_metadata(path)
-    }
-
-    fn get_dylib_metadata(&self, target: &Target, path: &Path) -> Result<MetadataRef, String> {
-        rustc_codegen_ssa::back::metadata::DefaultMetadataLoader.get_dylib_metadata(target, path)
-    }
-}
-
 #[derive(Clone)]
 struct SpirvCodegenBackend;
 
@@ -299,10 +286,6 @@ impl CodegenBackend for SpirvCodegenBackend {
         }
     }
 
-    fn metadata_loader(&self) -> Box<MetadataLoaderDyn> {
-        Box::new(SpirvMetadataLoader)
-    }
-
     fn provide(&self, providers: &mut query::Providers) {
         // This is a lil weird: so, we obviously don't support C ABIs at all. However, libcore does declare some extern
         // C functions:

crates/rustc_codegen_spirv/src/link.rs

@@ -8,9 +8,6 @@ use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModul
 use rustc_codegen_ssa::back::write::CodegenContext;
 use rustc_codegen_ssa::{CodegenResults, NativeLib, METADATA_FILENAME};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::owning_ref::OwningRef;
-use rustc_data_structures::rustc_erase_owner;
-use rustc_data_structures::sync::MetadataRef;
 use rustc_errors::FatalError;
 use rustc_middle::bug;
 use rustc_middle::dep_graph::WorkProduct;
@@ -481,27 +478,6 @@ fn create_archive(files: &[&Path], metadata: &[u8], out_filename: &Path) {
     builder.into_inner().unwrap();
 }
 
-pub fn read_metadata(rlib: &Path) -> Result<MetadataRef, String> {
-    fn read_metadata_internal(rlib: &Path) -> Result<Option<MetadataRef>, std::io::Error> {
-        let mut archive = Archive::new(File::open(rlib).unwrap());
-        while let Some(entry) = archive.next_entry() {
-            let mut entry = entry?;
-            if entry.header().identifier() == METADATA_FILENAME.as_bytes() {
-                let mut bytes = Vec::new();
-                entry.read_to_end(&mut bytes)?;
-                let buf: OwningRef<Vec<u8>, [u8]> = OwningRef::new(bytes);
-                return Ok(Some(rustc_erase_owner!(buf.map_owner_box())));
-            }
-        }
-        Ok(None)
-    }
-    match read_metadata_internal(rlib) {
-        Ok(Some(m)) => Ok(m),
-        Ok(None) => Err(format!("No .metadata file in rlib: {:?}", rlib)),
-        Err(io) => Err(format!("Failed to read rlib at {:?}: {}", rlib, io)),
-    }
-}
-
 /// This is the actual guts of linking: the rest of the link-related functions are just digging through rustc's
 /// shenanigans to collect all the object files we need to link.
 fn do_link(