Change `SymbolName::name` to a `&str`.

This eliminates a bunch of `Symbol::intern()` and `Symbol::as_str()`
calls, which is good, because they require locking the interner.

Note that the unsafety in `from_cycle_error()` is identical to the
unsafety on other adjacent impls.

3 files changed, 3 insertions, 4 deletions

diff --git a/src/librustc_codegen_llvm/debuginfo/metadata.rs b/src/librustc_codegen_llvm/debuginfo/metadata.rs
index f2e042cf86a..ef9d42968ae 100644
--- a/src/librustc_codegen_llvm/debuginfo/metadata.rs
+++ b/src/librustc_codegen_llvm/debuginfo/metadata.rs
@@ -2468,8 +2468,7 @@ pub fn create_global_var_metadata(cx: &CodegenCx<'ll, '_>, def_id: DefId, global
     let variable_type = Instance::mono(cx.tcx, def_id).monomorphic_ty(cx.tcx);
     let type_metadata = type_metadata(cx, variable_type, span);
     let var_name = tcx.item_name(def_id).as_str();
-    let linkage_name: &str =
-        &mangled_name_of_instance(cx, Instance::mono(tcx, def_id)).name.as_str();
+    let linkage_name = mangled_name_of_instance(cx, Instance::mono(tcx, def_id)).name;
     // When empty, linkage_name field is omitted,
     // which is what we want for no_mangle statics
     let linkage_name = if var_name == linkage_name { "" } else { linkage_name };
diff --git a/src/librustc_codegen_llvm/debuginfo/mod.rs b/src/librustc_codegen_llvm/debuginfo/mod.rs
index b5434298805..44993d7602f 100644
--- a/src/librustc_codegen_llvm/debuginfo/mod.rs
+++ b/src/librustc_codegen_llvm/debuginfo/mod.rs
@@ -267,7 +267,7 @@ impl DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         let substs = instance.substs.truncate_to(self.tcx(), generics);
         let template_parameters = get_template_parameters(self, &generics, substs, &mut name);
 
-        let linkage_name: &str = &mangled_name_of_instance(self, instance).name.as_str();
+        let linkage_name = &mangled_name_of_instance(self, instance).name;
         // Omit the linkage_name if it is the same as subprogram name.
         let linkage_name = if &name == linkage_name { "" } else { linkage_name };
 
diff --git a/src/librustc_codegen_llvm/debuginfo/namespace.rs b/src/librustc_codegen_llvm/debuginfo/namespace.rs
index 475dea239a7..d1a55335c44 100644
--- a/src/librustc_codegen_llvm/debuginfo/namespace.rs
+++ b/src/librustc_codegen_llvm/debuginfo/namespace.rs
@@ -12,7 +12,7 @@ use rustc_hir::definitions::DefPathData;
 pub fn mangled_name_of_instance<'a, 'tcx>(
     cx: &CodegenCx<'a, 'tcx>,
     instance: Instance<'tcx>,
-) -> ty::SymbolName {
+) -> ty::SymbolName<'tcx> {
     let tcx = cx.tcx;
     tcx.symbol_name(instance)
 }