Drop metadata_encoding_version.

Cargo.lock

@@ -3677,6 +3677,7 @@ dependencies = [
  "rustc_incremental",
  "rustc_index",
  "rustc_llvm",
+ "rustc_metadata",
  "rustc_middle",
  "rustc_serialize",
  "rustc_session",

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -14,6 +14,7 @@ extern crate rustc_fs_util;
 extern crate rustc_hir;
 extern crate rustc_incremental;
 extern crate rustc_index;
+extern crate rustc_metadata;
 extern crate rustc_session;
 extern crate rustc_span;
 extern crate rustc_target;

compiler/rustc_codegen_cranelift/src/metadata.rs

@@ -10,7 +10,7 @@ pub(crate) fn write_metadata<O: WriteMetadata>(tcx: TyCtxt<'_>, object: &mut O)
     use std::io::Write;
 
     let metadata = tcx.encode_metadata();
-    let mut compressed = tcx.metadata_encoding_version();
+    let mut compressed = rustc_metadata::METADATA_HEADER.to_vec();
     FrameEncoder::new(&mut compressed).write_all(&metadata.raw_data).unwrap();
 
     object.add_rustc_section(

compiler/rustc_codegen_llvm/Cargo.toml

@@ -27,6 +27,7 @@ rustc_hir = { path = "../rustc_hir" }
 rustc_incremental = { path = "../rustc_incremental" }
 rustc_index = { path = "../rustc_index" }
 rustc_llvm = { path = "../rustc_llvm" }
+rustc_metadata = { path = "../rustc_metadata" }
 rustc_session = { path = "../rustc_session" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_target = { path = "../rustc_target" }

compiler/rustc_codegen_llvm/src/base.rs

@@ -63,7 +63,7 @@ pub fn write_compressed_metadata<'tcx>(
     let section_name = if tcx.sess.target.is_like_osx { "__DATA,.rustc" } else { ".rustc" };
 
     let (metadata_llcx, metadata_llmod) = (&*llvm_module.llcx, llvm_module.llmod());
-    let mut compressed = tcx.metadata_encoding_version();
+    let mut compressed = rustc_metadata::METADATA_HEADER.to_vec();
     FrameEncoder::new(&mut compressed).write_all(&metadata.raw_data).unwrap();
 
     let llmeta = common::bytes_in_context(metadata_llcx, &compressed);

compiler/rustc_metadata/src/lib.rs

@@ -31,3 +31,5 @@ mod rmeta;
 pub mod creader;
 pub mod dynamic_lib;
 pub mod locator;
+
+pub use rmeta::METADATA_HEADER;

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -1,7 +1,7 @@
 use crate::creader::{CStore, LoadedMacro};
 use crate::foreign_modules;
 use crate::native_libs;
-use crate::rmeta::{self, encoder};
+use crate::rmeta::encoder;
 
 use rustc_ast as ast;
 use rustc_ast::expand::allocator::AllocatorKind;
@@ -528,10 +528,6 @@ impl CrateStore for CStore {
         encoder::encode_metadata(tcx)
     }
 
-    fn metadata_encoding_version(&self) -> &[u8] {
-        rmeta::METADATA_HEADER
-    }
-
     fn allocator_kind(&self) -> Option<AllocatorKind> {
         self.allocator_kind()
     }

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -51,7 +51,7 @@ const METADATA_VERSION: u8 = 5;
 /// This header is followed by the position of the `CrateRoot`,
 /// which is encoded as a 32-bit big-endian unsigned integer,
 /// and further followed by the rustc version string.
-crate const METADATA_HEADER: &[u8; 8] = &[b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
+pub const METADATA_HEADER: &[u8] = &[b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
 
 /// Additional metadata for a `Lazy<T>` where `T` may not be `Sized`,
 /// e.g. for `Lazy<[T]>`, this is the length (count of `T` values).

compiler/rustc_middle/src/middle/cstore.rs

@@ -209,7 +209,6 @@ pub trait CrateStore {
 
     // utility functions
     fn encode_metadata(&self, tcx: TyCtxt<'_>) -> EncodedMetadata;
-    fn metadata_encoding_version(&self) -> &[u8];
     fn allocator_kind(&self) -> Option<AllocatorKind>;
 }
 

compiler/rustc_middle/src/ty/context.rs

@@ -1314,10 +1314,6 @@ impl<'tcx> TyCtxt<'tcx> {
         )
     }
 
-    pub fn metadata_encoding_version(self) -> Vec<u8> {
-        self.cstore.metadata_encoding_version().to_vec()
-    }
-
     pub fn encode_metadata(self) -> EncodedMetadata {
         let _prof_timer = self.prof.verbose_generic_activity("generate_crate_metadata");
         self.cstore.encode_metadata(self)