Use List::empty() instead of mk_substs(&[]).

Author: nnethercote

compiler/rustc_codegen_gcc/src/context.rs

@@ -383,7 +383,7 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                     tcx,
                     ty::ParamEnv::reveal_all(),
                     def_id,
-                    tcx.mk_substs(&[]),
+                    ty::List::empty(),
                 )
                 .unwrap().unwrap(),
             ),

compiler/rustc_codegen_llvm/src/context.rs

@@ -520,7 +520,7 @@ impl<'ll, 'tcx> MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         let tcx = self.tcx;
         let llfn = match tcx.lang_items().eh_personality() {
             Some(def_id) if !wants_msvc_seh(self.sess()) => self.get_fn_addr(
-                ty::Instance::resolve(tcx, ty::ParamEnv::reveal_all(), def_id, tcx.mk_substs(&[]))
+                ty::Instance::resolve(tcx, ty::ParamEnv::reveal_all(), def_id, ty::List::empty())
                     .unwrap()
                     .unwrap(),
             ),

compiler/rustc_lint/src/builtin.rs

@@ -677,21 +677,21 @@ impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations {
                     return;
                 }
                 let def = cx.tcx.adt_def(item.owner_id);
-                (def, cx.tcx.mk_adt(def, cx.tcx.mk_substs(&[])))
+                (def, cx.tcx.mk_adt(def, ty::List::empty()))
             }
             hir::ItemKind::Union(_, ref ast_generics) => {
                 if !ast_generics.params.is_empty() {
                     return;
                 }
                 let def = cx.tcx.adt_def(item.owner_id);
-                (def, cx.tcx.mk_adt(def, cx.tcx.mk_substs(&[])))
+                (def, cx.tcx.mk_adt(def, ty::List::empty()))
             }
             hir::ItemKind::Enum(_, ref ast_generics) => {
                 if !ast_generics.params.is_empty() {
                     return;
                 }
                 let def = cx.tcx.adt_def(item.owner_id);
-                (def, cx.tcx.mk_adt(def, cx.tcx.mk_substs(&[])))
+                (def, cx.tcx.mk_adt(def, ty::List::empty()))
             }
             _ => return,
         };

compiler/rustc_middle/src/mir/mod.rs

@@ -2530,7 +2530,7 @@ impl<'tcx> ConstantKind<'tcx> {
         {
             InternalSubsts::identity_for_item(tcx, parent_did.to_def_id())
         } else {
-            tcx.mk_substs(&[])
+            List::empty()
         };
         debug!(?parent_substs);
 

src/tools/clippy/clippy_utils/src/consts.rs

@@ -237,7 +237,7 @@ pub fn constant<'tcx>(
         typeck_results,
         param_env: lcx.param_env,
         needed_resolution: false,
-        substs: lcx.tcx.mk_substs(&[]),
+        substs: ty::List::empty(),
     };
     cx.expr(e).map(|cst| (cst, cx.needed_resolution))
 }
@@ -306,7 +306,7 @@ pub fn constant_context<'a, 'tcx>(
         typeck_results,
         param_env: lcx.param_env,
         needed_resolution: false,
-        substs: lcx.tcx.mk_substs(&[]),
+        substs: ty::List::empty(),
     }
 }