Auto merge of #70040 - Dylan-DPC:rollup-id1k6lz, r=Dylan-DPC

Rollup of 7 pull requests

Successful merges:

 - #67335 (Refactor the `Qualif` trait)
 - #69122 (Backtrace Debug tweaks)
 - #69520 (Make error message clearer about creating new module)
 - #69738 (More Method -> AssocFn renaming)
 - #69867 (Add long error explanation for E0628 )
 - #69989 (resolve/hygiene: `macro_rules` are not "legacy")
 - #70036 (Make article_and_description primarily use def_kind)

Failed merges:

r? @ghost

82 files changed, 694 insertions, 579 deletions

diff --git a/src/librustc/hir/map/blocks.rs b/src/librustc/hir/map/blocks.rs
index d9ffe4582e7..7024e86f95d 100644
--- a/src/librustc/hir/map/blocks.rs
+++ b/src/librustc/hir/map/blocks.rs
@@ -51,7 +51,7 @@ impl MaybeFnLike for hir::Item<'_> {
 impl MaybeFnLike for hir::ImplItem<'_> {
     fn is_fn_like(&self) -> bool {
         match self.kind {
-            hir::ImplItemKind::Method(..) => true,
+            hir::ImplItemKind::Fn(..) => true,
             _ => false,
         }
     }
@@ -60,7 +60,7 @@ impl MaybeFnLike for hir::ImplItem<'_> {
 impl MaybeFnLike for hir::TraitItem<'_> {
     fn is_fn_like(&self) -> bool {
         match self.kind {
-            hir::TraitItemKind::Fn(_, hir::TraitMethod::Provided(_)) => true,
+            hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(_)) => true,
             _ => false,
         }
     }
@@ -239,13 +239,13 @@ impl<'a> FnLikeNode<'a> {
                 _ => bug!("item FnLikeNode that is not fn-like"),
             },
             Node::TraitItem(ti) => match ti.kind {
-                hir::TraitItemKind::Fn(ref sig, hir::TraitMethod::Provided(body)) => {
+                hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
                     method(ti.hir_id, ti.ident, sig, None, body, ti.span, &ti.attrs)
                 }
                 _ => bug!("trait method FnLikeNode that is not fn-like"),
             },
             Node::ImplItem(ii) => match ii.kind {
-                hir::ImplItemKind::Method(ref sig, body) => {
+                hir::ImplItemKind::Fn(ref sig, body) => {
                     method(ii.hir_id, ii.ident, sig, Some(&ii.vis), body, ii.span, &ii.attrs)
                 }
                 _ => bug!("impl method FnLikeNode that is not fn-like"),
diff --git a/src/librustc/hir/map/mod.rs b/src/librustc/hir/map/mod.rs
index bcbb6f3ec31..55ed07a97d1 100644
--- a/src/librustc/hir/map/mod.rs
+++ b/src/librustc/hir/map/mod.rs
@@ -56,7 +56,7 @@ fn fn_decl<'hir>(node: Node<'hir>) -> Option<&'hir FnDecl<'hir>> {
         },
 
         Node::ImplItem(ref item) => match item.kind {
-            ImplItemKind::Method(ref sig, _) => Some(&sig.decl),
+            ImplItemKind::Fn(ref sig, _) => Some(&sig.decl),
             _ => None,
         },
 
@@ -82,7 +82,7 @@ fn fn_sig<'hir>(node: Node<'hir>) -> Option<&'hir FnSig<'hir>> {
         },
 
         Node::ImplItem(item) => match &item.kind {
-            ImplItemKind::Method(sig, _) => Some(sig),
+            ImplItemKind::Fn(sig, _) => Some(sig),
             _ => None,
         },
 
@@ -100,13 +100,14 @@ fn associated_body<'hir>(node: Node<'hir>) -> Option<BodyId> {
         },
 
         Node::TraitItem(item) => match item.kind {
-            TraitItemKind::Const(_, Some(body))
-            | TraitItemKind::Fn(_, TraitMethod::Provided(body)) => Some(body),
+            TraitItemKind::Const(_, Some(body)) | TraitItemKind::Fn(_, TraitFn::Provided(body)) => {
+                Some(body)
+            }
             _ => None,
         },
 
         Node::ImplItem(item) => match item.kind {
-            ImplItemKind::Const(_, body) | ImplItemKind::Method(_, body) => Some(body),
+            ImplItemKind::Const(_, body) | ImplItemKind::Fn(_, body) => Some(body),
             _ => None,
         },
 
@@ -299,7 +300,7 @@ impl<'hir> Map<'hir> {
             },
             Node::ImplItem(item) => match item.kind {
                 ImplItemKind::Const(..) => DefKind::AssocConst,
-                ImplItemKind::Method(..) => DefKind::AssocFn,
+                ImplItemKind::Fn(..) => DefKind::AssocFn,
                 ImplItemKind::TyAlias(..) => DefKind::AssocTy,
                 ImplItemKind::OpaqueTy(..) => DefKind::AssocOpaqueTy,
             },
@@ -443,7 +444,7 @@ impl<'hir> Map<'hir> {
             Node::Ctor(..)
             | Node::Item(&Item { kind: ItemKind::Fn(..), .. })
             | Node::TraitItem(&TraitItem { kind: TraitItemKind::Fn(..), .. })
-            | Node::ImplItem(&ImplItem { kind: ImplItemKind::Method(..), .. }) => BodyOwnerKind::Fn,
+            | Node::ImplItem(&ImplItem { kind: ImplItemKind::Fn(..), .. }) => BodyOwnerKind::Fn,
             Node::Item(&Item { kind: ItemKind::Static(_, m, _), .. }) => BodyOwnerKind::Static(m),
             Node::Expr(&Expr { kind: ExprKind::Closure(..), .. }) => BodyOwnerKind::Closure,
             node => bug!("{:#?} is not a body node", node),
@@ -749,7 +750,7 @@ impl<'hir> Map<'hir> {
                     _ => false,
                 },
                 Node::ImplItem(ii) => match ii.kind {
-                    ImplItemKind::Method(..) => true,
+                    ImplItemKind::Fn(..) => true,
                     _ => false,
                 },
                 Node::Block(_) => true,
@@ -1110,7 +1111,7 @@ fn hir_id_to_string(map: &Map<'_>, id: HirId, include_id: bool) -> String {
             ImplItemKind::Const(..) => {
                 format!("assoc const {} in {}{}", ii.ident, path_str(), id_str)
             }
-            ImplItemKind::Method(..) => format!("method {} in {}{}", ii.ident, path_str(), id_str),
+            ImplItemKind::Fn(..) => format!("method {} in {}{}", ii.ident, path_str(), id_str),
             ImplItemKind::TyAlias(_) => {
                 format!("assoc type {} in {}{}", ii.ident, path_str(), id_str)
             }
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 611a2dc20b4..d6f6788697c 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -1520,20 +1520,21 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Returns a displayable description and article for the given `def_id` (e.g. `("a", "struct")`).
     pub fn article_and_description(&self, def_id: DefId) -> (&'static str, &'static str) {
-        match self.def_key(def_id).disambiguated_data.data {
-            DefPathData::TypeNs(..) | DefPathData::ValueNs(..) | DefPathData::MacroNs(..) => {
-                let kind = self.def_kind(def_id).unwrap();
-                (kind.article(), kind.descr(def_id))
-            }
-            DefPathData::ClosureExpr => match self.generator_kind(def_id) {
-                None => ("a", "closure"),
-                Some(rustc_hir::GeneratorKind::Async(..)) => ("an", "async closure"),
-                Some(rustc_hir::GeneratorKind::Gen) => ("a", "generator"),
-            },
-            DefPathData::LifetimeNs(..) => ("a", "lifetime"),
-            DefPathData::Impl => ("an", "implementation"),
-            _ => bug!("article_and_description called on def_id {:?}", def_id),
-        }
+        self.def_kind(def_id)
+            .map(|def_kind| (def_kind.article(), def_kind.descr(def_id)))
+            .unwrap_or_else(|| match self.def_key(def_id).disambiguated_data.data {
+                DefPathData::ClosureExpr => match self.generator_kind(def_id) {
+                    None => ("a", "closure"),
+                    Some(rustc_hir::GeneratorKind::Async(..)) => ("an", "async closure"),
+                    Some(rustc_hir::GeneratorKind::Gen) => ("a", "generator"),
+                },
+                DefPathData::LifetimeNs(..) => ("a", "lifetime"),
+                DefPathData::Impl => ("an", "implementation"),
+                DefPathData::TypeNs(..) | DefPathData::ValueNs(..) | DefPathData::MacroNs(..) => {
+                    unreachable!()
+                }
+                _ => bug!("article_and_description called on def_id {:?}", def_id),
+            })
     }
 }
 
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index d3c4ddf1ed3..338ff45a4ac 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -3083,7 +3083,7 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn hygienic_eq(self, use_name: Ident, def_name: Ident, def_parent_def_id: DefId) -> bool {
         // We could use `Ident::eq` here, but we deliberately don't. The name
         // comparison fails frequently, and we want to avoid the expensive
-        // `modern()` calls required for the span comparison whenever possible.
+        // `normalize_to_macros_2_0()` calls required for the span comparison whenever possible.
         use_name.name == def_name.name
             && use_name
                 .span
@@ -3099,7 +3099,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn adjust_ident(self, mut ident: Ident, scope: DefId) -> Ident {
-        ident.span.modernize_and_adjust(self.expansion_that_defined(scope));
+        ident.span.normalize_to_macros_2_0_and_adjust(self.expansion_that_defined(scope));
         ident
     }
 
@@ -3109,12 +3109,14 @@ impl<'tcx> TyCtxt<'tcx> {
         scope: DefId,
         block: hir::HirId,
     ) -> (Ident, DefId) {
-        let scope = match ident.span.modernize_and_adjust(self.expansion_that_defined(scope)) {
-            Some(actual_expansion) => {
-                self.hir().definitions().parent_module_of_macro_def(actual_expansion)
-            }
-            None => self.parent_module(block),
-        };
+        let scope =
+            match ident.span.normalize_to_macros_2_0_and_adjust(self.expansion_that_defined(scope))
+            {
+                Some(actual_expansion) => {
+                    self.hir().definitions().parent_module_of_macro_def(actual_expansion)
+                }
+                None => self.parent_module(block),
+            };
         (ident, scope)
     }
 
diff --git a/src/librustc_ast/ast.rs b/src/librustc_ast/ast.rs
index 08ce0cc2c56..68960ba9fe9 100644
--- a/src/librustc_ast/ast.rs
+++ b/src/librustc_ast/ast.rs
@@ -1450,7 +1450,7 @@ impl MacDelimiter {
 pub struct MacroDef {
     pub body: P<MacArgs>,
     /// `true` if macro was defined with `macro_rules`.
-    pub legacy: bool,
+    pub macro_rules: bool,
 }
 
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, Hash, Eq, PartialEq)]
diff --git a/src/librustc_ast/mut_visit.rs b/src/librustc_ast/mut_visit.rs
index a1a5b9debc5..aa2968b3cbe 100644
--- a/src/librustc_ast/mut_visit.rs
+++ b/src/librustc_ast/mut_visit.rs
@@ -591,7 +591,7 @@ pub fn noop_visit_mac<T: MutVisitor>(mac: &mut MacCall, vis: &mut T) {
 }
 
 pub fn noop_visit_macro_def<T: MutVisitor>(macro_def: &mut MacroDef, vis: &mut T) {
-    let MacroDef { body, legacy: _ } = macro_def;
+    let MacroDef { body, macro_rules: _ } = macro_def;
     visit_mac_args(body, vis);
 }
 
diff --git a/src/librustc_ast_lowering/item.rs b/src/librustc_ast_lowering/item.rs
index 2c60fe9c077..aab6aa7c35b 100644
--- a/src/librustc_ast_lowering/item.rs
+++ b/src/librustc_ast_lowering/item.rs
@@ -115,7 +115,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             _ => &[],
         };
         let lt_def_names = parent_generics.iter().filter_map(|param| match param.kind {
-            hir::GenericParamKind::Lifetime { .. } => Some(param.name.modern()),
+            hir::GenericParamKind::Lifetime { .. } => Some(param.name.normalize_to_macros_2_0()),
             _ => None,
         });
         self.in_scope_lifetimes.extend(lt_def_names);
@@ -220,8 +220,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let mut vis = self.lower_visibility(&i.vis, None);
         let attrs = self.lower_attrs(&i.attrs);
 
-        if let ItemKind::MacroDef(MacroDef { ref body, legacy }) = i.kind {
-            if !legacy || attr::contains_name(&i.attrs, sym::macro_export) {
+        if let ItemKind::MacroDef(MacroDef { ref body, macro_rules }) = i.kind {
+            if !macro_rules || attr::contains_name(&i.attrs, sym::macro_export) {
                 let hir_id = self.lower_node_id(i.id);
                 let body = P(self.lower_mac_args(body));
                 self.exported_macros.push(hir::MacroDef {
@@ -230,7 +230,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     attrs,
                     hir_id,
                     span: i.span,
-                    ast: MacroDef { body, legacy },
+                    ast: MacroDef { body, macro_rules },
                 });
             } else {
                 self.non_exported_macro_attrs.extend(attrs.iter().cloned());
@@ -761,13 +761,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 let names = self.lower_fn_params_to_names(&sig.decl);
                 let (generics, sig) =
                     self.lower_method_sig(generics, sig, trait_item_def_id, false, None);
-                (generics, hir::TraitItemKind::Fn(sig, hir::TraitMethod::Required(names)))
+                (generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Required(names)))
             }
             AssocItemKind::Fn(_, ref sig, ref generics, Some(ref body)) => {
                 let body_id = self.lower_fn_body_block(i.span, &sig.decl, Some(body));
                 let (generics, sig) =
                     self.lower_method_sig(generics, sig, trait_item_def_id, false, None);
-                (generics, hir::TraitItemKind::Fn(sig, hir::TraitMethod::Provided(body_id)))
+                (generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Provided(body_id)))
             }
             AssocItemKind::TyAlias(_, ref generics, ref bounds, ref default) => {
                 let ty = default.as_ref().map(|x| self.lower_ty(x, ImplTraitContext::disallowed()));
@@ -838,7 +838,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     asyncness.opt_return_id(),
                 );
 
-                (generics, hir::ImplItemKind::Method(sig, body_id))
+                (generics, hir::ImplItemKind::Fn(sig, body_id))
             }
             AssocItemKind::TyAlias(_, generics, _, ty) => {
                 let generics = self.lower_generics(generics, ImplTraitContext::disallowed());
diff --git a/src/librustc_ast_lowering/lib.rs b/src/librustc_ast_lowering/lib.rs
index 3ef02d7c61e..32b0f0db358 100644
--- a/src/librustc_ast_lowering/lib.rs
+++ b/src/librustc_ast_lowering/lib.rs
@@ -153,7 +153,7 @@ struct LoweringContext<'a, 'hir: 'a> {
     /// against this list to see if it is already in-scope, or if a definition
     /// needs to be created for it.
     ///
-    /// We always store a `modern()` version of the param-name in this
+    /// We always store a `normalize_to_macros_2_0()` version of the param-name in this
     /// vector.
     in_scope_lifetimes: Vec<ParamName>,
 
@@ -803,14 +803,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             return;
         }
 
-        if self.in_scope_lifetimes.contains(&ParamName::Plain(ident.modern())) {
+        if self.in_scope_lifetimes.contains(&ParamName::Plain(ident.normalize_to_macros_2_0())) {
             return;
         }
 
         let hir_name = ParamName::Plain(ident);
 
-        if self.lifetimes_to_define.iter().any(|(_, lt_name)| lt_name.modern() == hir_name.modern())
-        {
+        if self.lifetimes_to_define.iter().any(|(_, lt_name)| {
+            lt_name.normalize_to_macros_2_0() == hir_name.normalize_to_macros_2_0()
+        }) {
             return;
         }
 
@@ -838,7 +839,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     ) -> T {
         let old_len = self.in_scope_lifetimes.len();
         let lt_def_names = params.iter().filter_map(|param| match param.kind {
-            GenericParamKind::Lifetime { .. } => Some(ParamName::Plain(param.ident.modern())),
+            GenericParamKind::Lifetime { .. } => {
+                Some(ParamName::Plain(param.ident.normalize_to_macros_2_0()))
+            }
             _ => None,
         });
         self.in_scope_lifetimes.extend(lt_def_names);
diff --git a/src/librustc_ast_passes/feature_gate.rs b/src/librustc_ast_passes/feature_gate.rs
index 66be2b49ada..2a9847c900e 100644
--- a/src/librustc_ast_passes/feature_gate.rs
+++ b/src/librustc_ast_passes/feature_gate.rs
@@ -366,7 +366,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                 gate_feature_post!(&self, trait_alias, i.span, "trait aliases are experimental");
             }
 
-            ast::ItemKind::MacroDef(ast::MacroDef { legacy: false, .. }) => {
+            ast::ItemKind::MacroDef(ast::MacroDef { macro_rules: false, .. }) => {
                 let msg = "`macro` is experimental";
                 gate_feature_post!(&self, decl_macro, i.span, msg);
             }
diff --git a/src/librustc_ast_pretty/pprust.rs b/src/librustc_ast_pretty/pprust.rs
index a81b28d7c39..b2e6ab7c5e7 100644
--- a/src/librustc_ast_pretty/pprust.rs
+++ b/src/librustc_ast_pretty/pprust.rs
@@ -1238,7 +1238,7 @@ impl<'a> State<'a> {
                 }
             }
             ast::ItemKind::MacroDef(ref macro_def) => {
-                let (kw, has_bang) = if macro_def.legacy {
+                let (kw, has_bang) = if macro_def.macro_rules {
                     ("macro_rules", true)
                 } else {
                     self.print_visibility(&item.vis);
diff --git a/src/librustc_attr/builtin.rs b/src/librustc_attr/builtin.rs
index 08eae24da9b..99083cca6cb 100644
--- a/src/librustc_attr/builtin.rs
+++ b/src/librustc_attr/builtin.rs
@@ -1024,7 +1024,7 @@ pub enum TransparencyError {
 
 pub fn find_transparency(
     attrs: &[Attribute],
-    is_legacy: bool,
+    macro_rules: bool,
 ) -> (Transparency, Option<TransparencyError>) {
     let mut transparency = None;
     let mut error = None;
@@ -1049,7 +1049,7 @@ pub fn find_transparency(
             }
         }
     }
-    let fallback = if is_legacy { Transparency::SemiTransparent } else { Transparency::Opaque };
+    let fallback = if macro_rules { Transparency::SemiTransparent } else { Transparency::Opaque };
     (transparency.map_or(fallback, |t| t.0), error)
 }
 
diff --git a/src/librustc_codegen_ssa/back/symbol_export.rs b/src/librustc_codegen_ssa/back/symbol_export.rs
index 3fe256ce25b..178a74c791b 100644
--- a/src/librustc_codegen_ssa/back/symbol_export.rs
+++ b/src/librustc_codegen_ssa/back/symbol_export.rs
@@ -88,7 +88,7 @@ fn reachable_non_generics_provider(
                 // Only consider nodes that actually have exported symbols.
                 Node::Item(&hir::Item { kind: hir::ItemKind::Static(..), .. })
                 | Node::Item(&hir::Item { kind: hir::ItemKind::Fn(..), .. })
-                | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Method(..), .. }) => {
+                | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. }) => {
                     let def_id = tcx.hir().local_def_id(hir_id);
                     let generics = tcx.generics_of(def_id);
                     if !generics.requires_monomorphization(tcx) &&
diff --git a/src/librustc_error_codes/error_codes.rs b/src/librustc_error_codes/error_codes.rs
index 59a030bc4c6..85339ab9aa1 100644
--- a/src/librustc_error_codes/error_codes.rs
+++ b/src/librustc_error_codes/error_codes.rs
@@ -349,6 +349,7 @@ E0623: include_str!("./error_codes/E0623.md"),
 E0624: include_str!("./error_codes/E0624.md"),
 E0626: include_str!("./error_codes/E0626.md"),
 E0627: include_str!("./error_codes/E0627.md"),
+E0628: include_str!("./error_codes/E0628.md"),
 E0631: include_str!("./error_codes/E0631.md"),
 E0633: include_str!("./error_codes/E0633.md"),
 E0634: include_str!("./error_codes/E0634.md"),
@@ -583,7 +584,6 @@ E0748: include_str!("./error_codes/E0748.md"),
 //  E0612, // merged into E0609
 //  E0613, // Removed (merged with E0609)
     E0625, // thread-local statics cannot be accessed at compile-time
-    E0628, // generators cannot have explicit parameters
     E0629, // missing 'feature' (rustc_const_unstable)
     // rustc_const_unstable attribute must be paired with stable/unstable
     // attribute
diff --git a/src/librustc_error_codes/error_codes/E0628.md b/src/librustc_error_codes/error_codes/E0628.md
new file mode 100644
index 00000000000..40040c9a56a
--- /dev/null
+++ b/src/librustc_error_codes/error_codes/E0628.md
@@ -0,0 +1,30 @@
+More than one parameter was used for a generator.
+
+Erroneous code example:
+
+```compile_fail,E0628
+#![feature(generators, generator_trait)]
+
+fn main() {
+    let generator = |a: i32, b: i32| {
+        // error: too many parameters for a generator
+        // Allowed only 0 or 1 parameter
+        yield a;
+    };
+}
+```
+
+At present, it is not permitted to pass more than one explicit
+parameter for a generator.This can be fixed by using
+at most 1 parameter for the generator. For example, we might resolve
+the previous example by passing only one parameter.
+
+```
+#![feature(generators, generator_trait)]
+
+fn main() {
+    let generator = |a: i32| {
+        yield a;
+    };
+}
+```
diff --git a/src/librustc_expand/mbe/macro_check.rs b/src/librustc_expand/mbe/macro_check.rs
index 6eb834beac6..8c6bfbec902 100644
--- a/src/librustc_expand/mbe/macro_check.rs
+++ b/src/librustc_expand/mbe/macro_check.rs
@@ -419,10 +419,10 @@ fn check_nested_occurrences(
             | (NestedMacroState::MacroName, &TokenTree::Delimited(_, ref del))
                 if del.delim == DelimToken::Brace =>
             {
-                let legacy = state == NestedMacroState::MacroRulesNotName;
+                let macro_rules = state == NestedMacroState::MacroRulesNotName;
                 state = NestedMacroState::Empty;
                 let rest =
-                    check_nested_macro(sess, node_id, legacy, &del.tts, &nested_macros, valid);
+                    check_nested_macro(sess, node_id, macro_rules, &del.tts, &nested_macros, valid);
                 // If we did not check the whole macro definition, then check the rest as if outside
                 // the macro definition.
                 check_nested_occurrences(
@@ -493,21 +493,21 @@ fn check_nested_occurrences(
 /// Arguments:
 /// - `sess` is used to emit diagnostics and lints
 /// - `node_id` is used to emit lints
-/// - `legacy` specifies whether the macro is legacy
+/// - `macro_rules` specifies whether the macro is `macro_rules`
 /// - `tts` is checked as a list of (LHS) => {RHS}
 /// - `macros` is the stack of outer macros
 /// - `valid` is set in case of errors
 fn check_nested_macro(
     sess: &ParseSess,
     node_id: NodeId,
-    legacy: bool,
+    macro_rules: bool,
     tts: &[TokenTree],
     macros: &Stack<'_, MacroState<'_>>,
     valid: &mut bool,
 ) -> usize {
     let n = tts.len();
     let mut i = 0;
-    let separator = if legacy { TokenKind::Semi } else { TokenKind::Comma };
+    let separator = if macro_rules { TokenKind::Semi } else { TokenKind::Comma };
     loop {
         // We expect 3 token trees: `(LHS) => {RHS}`. The separator is checked after.
         if i + 2 >= n
@@ -522,7 +522,7 @@ fn check_nested_macro(
         let mut binders = Binders::default();
         check_binders(sess, node_id, lhs, macros, &mut binders, &Stack::Empty, valid);
         check_occurrences(sess, node_id, rhs, macros, &binders, &Stack::Empty, valid);
-        // Since the last semicolon is optional for legacy macros and decl_macro are not terminated,
+        // Since the last semicolon is optional for `macro_rules` macros and decl_macro are not terminated,
         // we increment our checked position by how many token trees we already checked (the 3
         // above) before checking for the separator.
         i += 3;
diff --git a/src/librustc_expand/mbe/macro_rules.rs b/src/librustc_expand/mbe/macro_rules.rs
index 3040a9aefbb..3cad3ff55d9 100644
--- a/src/librustc_expand/mbe/macro_rules.rs
+++ b/src/librustc_expand/mbe/macro_rules.rs
@@ -350,8 +350,8 @@ pub fn compile_declarative_macro(
     let tt_spec = ast::Ident::new(sym::tt, def.span);
 
     // Parse the macro_rules! invocation
-    let (is_legacy, body) = match &def.kind {
-        ast::ItemKind::MacroDef(macro_def) => (macro_def.legacy, macro_def.body.inner_tokens()),
+    let (macro_rules, body) = match &def.kind {
+        ast::ItemKind::MacroDef(def) => (def.macro_rules, def.body.inner_tokens()),
         _ => unreachable!(),
     };
 
@@ -370,7 +370,7 @@ pub fn compile_declarative_macro(
                     mbe::TokenTree::MetaVarDecl(def.span, rhs_nm, tt_spec),
                 ],
                 separator: Some(Token::new(
-                    if is_legacy { token::Semi } else { token::Comma },
+                    if macro_rules { token::Semi } else { token::Comma },
                     def.span,
                 )),
                 kleene: mbe::KleeneToken::new(mbe::KleeneOp::OneOrMore, def.span),
@@ -382,7 +382,7 @@ pub fn compile_declarative_macro(
             DelimSpan::dummy(),
             Lrc::new(mbe::SequenceRepetition {
                 tts: vec![mbe::TokenTree::token(
-                    if is_legacy { token::Semi } else { token::Comma },
+                    if macro_rules { token::Semi } else { token::Comma },
                     def.span,
                 )],
                 separator: None,
@@ -456,7 +456,7 @@ pub fn compile_declarative_macro(
     // that is not lint-checked and trigger the "failed to process buffered lint here" bug.
     valid &= macro_check::check_meta_variables(sess, ast::CRATE_NODE_ID, def.span, &lhses, &rhses);
 
-    let (transparency, transparency_error) = attr::find_transparency(&def.attrs, is_legacy);
+    let (transparency, transparency_error) = attr::find_transparency(&def.attrs, macro_rules);
     match transparency_error {
         Some(TransparencyError::UnknownTransparency(value, span)) => {
             diag.span_err(span, &format!("unknown macro transparency: `{}`", value))
diff --git a/src/librustc_hir/hir.rs b/src/librustc_hir/hir.rs
index 48b423de268..0ef35b184e1 100644
--- a/src/librustc_hir/hir.rs
+++ b/src/librustc_hir/hir.rs
@@ -79,9 +79,9 @@ impl ParamName {
         }
     }
 
-    pub fn modern(&self) -> ParamName {
+    pub fn normalize_to_macros_2_0(&self) -> ParamName {
         match *self {
-            ParamName::Plain(ident) => ParamName::Plain(ident.modern()),
+            ParamName::Plain(ident) => ParamName::Plain(ident.normalize_to_macros_2_0()),
             param_name => param_name,
         }
     }
@@ -151,9 +151,11 @@ impl LifetimeName {
         self == &LifetimeName::Static
     }
 
-    pub fn modern(&self) -> LifetimeName {
+    pub fn normalize_to_macros_2_0(&self) -> LifetimeName {
         match *self {
-            LifetimeName::Param(param_name) => LifetimeName::Param(param_name.modern()),
+            LifetimeName::Param(param_name) => {
+                LifetimeName::Param(param_name.normalize_to_macros_2_0())
+            }
             lifetime_name => lifetime_name,
         }
     }
@@ -1854,7 +1856,7 @@ pub struct TraitItem<'hir> {
 
 /// Represents a trait method's body (or just argument names).
 #[derive(RustcEncodable, RustcDecodable, Debug, HashStable_Generic)]
-pub enum TraitMethod<'hir> {
+pub enum TraitFn<'hir> {
     /// No default body in the trait, just a signature.
     Required(&'hir [Ident]),
 
@@ -1868,7 +1870,7 @@ pub enum TraitItemKind<'hir> {
     /// An associated constant with an optional value (otherwise `impl`s must contain a value).
     Const(&'hir Ty<'hir>, Option<BodyId>),
     /// An associated function with an optional body.
-    Fn(FnSig<'hir>, TraitMethod<'hir>),
+    Fn(FnSig<'hir>, TraitFn<'hir>),
     /// An associated type with (possibly empty) bounds and optional concrete
     /// type.
     Type(GenericBounds<'hir>, Option<&'hir Ty<'hir>>),
@@ -1901,8 +1903,8 @@ pub enum ImplItemKind<'hir> {
     /// An associated constant of the given type, set to the constant result
     /// of the expression.
     Const(&'hir Ty<'hir>, BodyId),
-    /// A method implementation with the given signature and body.
-    Method(FnSig<'hir>, BodyId),
+    /// An associated function implementation with the given signature and body.
+    Fn(FnSig<'hir>, BodyId),
     /// An associated type.
     TyAlias(&'hir Ty<'hir>),
     /// An associated `type = impl Trait`.
@@ -1913,7 +1915,7 @@ impl ImplItemKind<'_> {
     pub fn namespace(&self) -> Namespace {
         match self {
             ImplItemKind::OpaqueTy(..) | ImplItemKind::TyAlias(..) => Namespace::TypeNS,
-            ImplItemKind::Const(..) | ImplItemKind::Method(..) => Namespace::ValueNS,
+            ImplItemKind::Const(..) | ImplItemKind::Fn(..) => Namespace::ValueNS,
         }
     }
 }
@@ -2704,7 +2706,7 @@ impl Node<'_> {
     pub fn fn_decl(&self) -> Option<&FnDecl<'_>> {
         match self {
             Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
-            | Node::ImplItem(ImplItem { kind: ImplItemKind::Method(fn_sig, _), .. })
+            | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
             | Node::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig.decl),
             Node::ForeignItem(ForeignItem { kind: ForeignItemKind::Fn(fn_decl, _, _), .. }) => {
                 Some(fn_decl)
diff --git a/src/librustc_hir/intravisit.rs b/src/librustc_hir/intravisit.rs
index 79c7f34dd53..b13f1a91b03 100644
--- a/src/librustc_hir/intravisit.rs
+++ b/src/librustc_hir/intravisit.rs
@@ -911,14 +911,14 @@ pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v Trai
             visitor.visit_ty(ty);
             walk_list!(visitor, visit_nested_body, default);
         }
-        TraitItemKind::Fn(ref sig, TraitMethod::Required(param_names)) => {
+        TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
             visitor.visit_id(trait_item.hir_id);
             visitor.visit_fn_decl(&sig.decl);
             for &param_name in param_names {
                 visitor.visit_ident(param_name);
             }
         }
-        TraitItemKind::Fn(ref sig, TraitMethod::Provided(body_id)) => {
+        TraitItemKind::Fn(ref sig, TraitFn::Provided(body_id)) => {
             visitor.visit_fn(
                 FnKind::Method(trait_item.ident, sig, None, &trait_item.attrs),
                 &sig.decl,
@@ -968,7 +968,7 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplIt
             visitor.visit_ty(ty);
             visitor.visit_nested_body(body);
         }
-        ImplItemKind::Method(ref sig, body_id) => {
+        ImplItemKind::Fn(ref sig, body_id) => {
             visitor.visit_fn(
                 FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), &impl_item.attrs),
                 &sig.decl,
diff --git a/src/librustc_hir/print.rs b/src/librustc_hir/print.rs
index 1a2c3a38565..4e9618b7676 100644
--- a/src/librustc_hir/print.rs
+++ b/src/librustc_hir/print.rs
@@ -886,13 +886,13 @@ impl<'a> State<'a> {
                     Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Inherited };
                 self.print_associated_const(ti.ident, &ty, default, &vis);
             }
-            hir::TraitItemKind::Fn(ref sig, hir::TraitMethod::Required(ref arg_names)) => {
+            hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(ref arg_names)) => {
                 let vis =
                     Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Inherited };
                 self.print_method_sig(ti.ident, sig, &ti.generics, &vis, arg_names, None);
                 self.s.word(";");
             }
-            hir::TraitItemKind::Fn(ref sig, hir::TraitMethod::Provided(body)) => {
+            hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
                 let vis =
                     Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Inherited };
                 self.head("");
@@ -925,7 +925,7 @@ impl<'a> State<'a> {
             hir::ImplItemKind::Const(ref ty, expr) => {
                 self.print_associated_const(ii.ident, &ty, Some(expr), &ii.vis);
             }
-            hir::ImplItemKind::Method(ref sig, body) => {
+            hir::ImplItemKind::Fn(ref sig, body) => {
                 self.head("");
                 self.print_method_sig(ii.ident, sig, &ii.generics, &ii.vis, &[], Some(body));
                 self.nbsp();
diff --git a/src/librustc_hir/target.rs b/src/librustc_hir/target.rs
index b7bc555d7b4..3a4485a1b17 100644
--- a/src/librustc_hir/target.rs
+++ b/src/librustc_hir/target.rs
@@ -105,10 +105,10 @@ impl Target {
     pub fn from_trait_item(trait_item: &TraitItem<'_>) -> Target {
         match trait_item.kind {
             TraitItemKind::Const(..) => Target::AssocConst,
-            TraitItemKind::Fn(_, hir::TraitMethod::Required(_)) => {
+            TraitItemKind::Fn(_, hir::TraitFn::Required(_)) => {
                 Target::Method(MethodKind::Trait { body: false })
             }
-            TraitItemKind::Fn(_, hir::TraitMethod::Provided(_)) => {
+            TraitItemKind::Fn(_, hir::TraitFn::Provided(_)) => {
                 Target::Method(MethodKind::Trait { body: true })
             }
             TraitItemKind::Type(..) => Target::AssocTy,
diff --git a/src/librustc_incremental/persist/dirty_clean.rs b/src/librustc_incremental/persist/dirty_clean.rs
index cfc0a5e1498..df5fd110db9 100644
--- a/src/librustc_incremental/persist/dirty_clean.rs
+++ b/src/librustc_incremental/persist/dirty_clean.rs
@@ -333,7 +333,7 @@ impl DirtyCleanVisitor<'tcx> {
                 TraitItemKind::Type(..) => ("NodeTraitType", LABELS_CONST_IN_TRAIT),
             },
             HirNode::ImplItem(item) => match item.kind {
-                ImplItemKind::Method(..) => ("Node::ImplItem", LABELS_FN_IN_IMPL),
+                ImplItemKind::Fn(..) => ("Node::ImplItem", LABELS_FN_IN_IMPL),
                 ImplItemKind::Const(..) => ("NodeImplConst", LABELS_CONST_IN_IMPL),
                 ImplItemKind::TyAlias(..) => ("NodeImplType", LABELS_CONST_IN_IMPL),
                 ImplItemKind::OpaqueTy(..) => ("NodeImplType", LABELS_CONST_IN_IMPL),
diff --git a/src/librustc_infer/infer/error_reporting/mod.rs b/src/librustc_infer/infer/error_reporting/mod.rs
index 4a39403f211..a544381f33d 100644
--- a/src/librustc_infer/infer/error_reporting/mod.rs
+++ b/src/librustc_infer/infer/error_reporting/mod.rs
@@ -275,7 +275,7 @@ fn trait_item_scope_tag(item: &hir::TraitItem<'_>) -> &'static str {
 
 fn impl_item_scope_tag(item: &hir::ImplItem<'_>) -> &'static str {
     match item.kind {
-        hir::ImplItemKind::Method(..) => "method body",
+        hir::ImplItemKind::Fn(..) => "method body",
         hir::ImplItemKind::Const(..)
         | hir::ImplItemKind::OpaqueTy(..)
         | hir::ImplItemKind::TyAlias(..) => "associated item",
diff --git a/src/librustc_infer/infer/error_reporting/nice_region_error/find_anon_type.rs b/src/librustc_infer/infer/error_reporting/nice_region_error/find_anon_type.rs
index 47d6f5ccbb1..15acf632b2c 100644
--- a/src/librustc_infer/infer/error_reporting/nice_region_error/find_anon_type.rs
+++ b/src/librustc_infer/infer/error_reporting/nice_region_error/find_anon_type.rs
@@ -37,7 +37,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                         ..
                     })
                     | Node::ImplItem(&hir::ImplItem {
-                        kind: hir::ImplItemKind::Method(ref m, ..),
+                        kind: hir::ImplItemKind::Fn(ref m, ..),
                         ..
                     }) => &m.decl,
                     _ => return None,
diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs
index ab8a6070721..54b8fad3930 100644
--- a/src/librustc_lint/builtin.rs
+++ b/src/librustc_lint/builtin.rs
@@ -486,7 +486,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDoc {
 
         let desc = match impl_item.kind {
             hir::ImplItemKind::Const(..) => "an associated constant",
-            hir::ImplItemKind::Method(..) => "a method",
+            hir::ImplItemKind::Fn(..) => "a method",
             hir::ImplItemKind::TyAlias(_) => "an associated type",
             hir::ImplItemKind::OpaqueTy(_) => "an associated `impl Trait` type",
         };
diff --git a/src/librustc_lint/nonstandard_style.rs b/src/librustc_lint/nonstandard_style.rs
index 37fefe680d7..afab55358d9 100644
--- a/src/librustc_lint/nonstandard_style.rs
+++ b/src/librustc_lint/nonstandard_style.rs
@@ -343,7 +343,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonSnakeCase {
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'_, '_>, item: &hir::TraitItem<'_>) {
-        if let hir::TraitItemKind::Fn(_, hir::TraitMethod::Required(pnames)) = item.kind {
+        if let hir::TraitItemKind::Fn(_, hir::TraitFn::Required(pnames)) = item.kind {
             self.check_snake_case(cx, "trait method", &item.ident);
             for param_name in pnames {
                 self.check_snake_case(cx, "variable", param_name);
diff --git a/src/librustc_metadata/rmeta/decoder.rs b/src/librustc_metadata/rmeta/decoder.rs
index 7126f86c326..b37e339bab3 100644
--- a/src/librustc_metadata/rmeta/decoder.rs
+++ b/src/librustc_metadata/rmeta/decoder.rs
@@ -505,7 +505,7 @@ impl EntryKind {
             EntryKind::Struct(_, _) => DefKind::Struct,
             EntryKind::Union(_, _) => DefKind::Union,
             EntryKind::Fn(_) | EntryKind::ForeignFn(_) => DefKind::Fn,
-            EntryKind::Method(_) => DefKind::AssocFn,
+            EntryKind::AssocFn(_) => DefKind::AssocFn,
             EntryKind::Type => DefKind::TyAlias,
             EntryKind::TypeParam => DefKind::TyParam,
             EntryKind::ConstParam => DefKind::ConstParam,
@@ -1067,7 +1067,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
 
         let (kind, container, has_self) = match self.kind(id) {
             EntryKind::AssocConst(container, _, _) => (ty::AssocKind::Const, container, false),
-            EntryKind::Method(data) => {
+            EntryKind::AssocFn(data) => {
                 let data = data.decode(self);
                 (ty::AssocKind::Method, data.container, data.has_self)
             }
@@ -1249,7 +1249,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     fn get_fn_param_names(&self, id: DefIndex) -> Vec<ast::Name> {
         let param_names = match self.kind(id) {
             EntryKind::Fn(data) | EntryKind::ForeignFn(data) => data.decode(self).param_names,
-            EntryKind::Method(data) => data.decode(self).fn_data.param_names,
+            EntryKind::AssocFn(data) => data.decode(self).fn_data.param_names,
             _ => Lazy::empty(),
         };
         param_names.decode(self).collect()
@@ -1286,7 +1286,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     // don't serialize constness for tuple variant and tuple struct constructors.
     fn is_const_fn_raw(&self, id: DefIndex) -> bool {
         let constness = match self.kind(id) {
-            EntryKind::Method(data) => data.decode(self).fn_data.constness,
+            EntryKind::AssocFn(data) => data.decode(self).fn_data.constness,
             EntryKind::Fn(data) => data.decode(self).constness,
             // Some intrinsics can be const fn. While we could recompute this (at least until we
             // stop having hardcoded whitelists and move to stability attributes), it seems cleaner
@@ -1301,7 +1301,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     fn asyncness(&self, id: DefIndex) -> hir::IsAsync {
         match self.kind(id) {
             EntryKind::Fn(data) => data.decode(self).asyncness,
-            EntryKind::Method(data) => data.decode(self).fn_data.asyncness,
+            EntryKind::AssocFn(data) => data.decode(self).fn_data.asyncness,
             EntryKind::ForeignFn(data) => data.decode(self).asyncness,
             _ => bug!("asyncness: expected function kind"),
         }
diff --git a/src/librustc_metadata/rmeta/encoder.rs b/src/librustc_metadata/rmeta/encoder.rs
index 8b589f70651..005bebbe1e2 100644
--- a/src/librustc_metadata/rmeta/encoder.rs
+++ b/src/librustc_metadata/rmeta/encoder.rs
@@ -807,10 +807,10 @@ impl EncodeContext<'tcx> {
             ty::AssocKind::Method => {
                 let fn_data = if let hir::TraitItemKind::Fn(m_sig, m) = &ast_item.kind {
                     let param_names = match *m {
-                        hir::TraitMethod::Required(ref names) => {
+                        hir::TraitFn::Required(ref names) => {
                             self.encode_fn_param_names(names)
                         }
-                        hir::TraitMethod::Provided(body) => {
+                        hir::TraitFn::Provided(body) => {
                             self.encode_fn_param_names_for_body(body)
                         }
                     };
@@ -822,7 +822,7 @@ impl EncodeContext<'tcx> {
                 } else {
                     bug!()
                 };
-                EntryKind::Method(self.lazy(MethodData {
+                EntryKind::AssocFn(self.lazy(AssocFnData {
                     fn_data,
                     container,
                     has_self: trait_item.method_has_self_argument,
@@ -894,7 +894,7 @@ impl EncodeContext<'tcx> {
                 }
             }
             ty::AssocKind::Method => {
-                let fn_data = if let hir::ImplItemKind::Method(ref sig, body) = ast_item.kind {
+                let fn_data = if let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind {
                     FnData {
                         asyncness: sig.header.asyncness,
                         constness: sig.header.constness,
@@ -903,7 +903,7 @@ impl EncodeContext<'tcx> {
                 } else {
                     bug!()
                 };
-                EntryKind::Method(self.lazy(MethodData {
+                EntryKind::AssocFn(self.lazy(AssocFnData {
                     fn_data,
                     container,
                     has_self: impl_item.method_has_self_argument,
@@ -928,7 +928,7 @@ impl EncodeContext<'tcx> {
         self.encode_inferred_outlives(def_id);
         let mir = match ast_item.kind {
             hir::ImplItemKind::Const(..) => true,
-            hir::ImplItemKind::Method(ref sig, _) => {
+            hir::ImplItemKind::Fn(ref sig, _) => {
                 let generics = self.tcx.generics_of(def_id);
                 let needs_inline = (generics.requires_monomorphization(self.tcx)
                     || tcx.codegen_fn_attrs(def_id).requests_inline())
diff --git a/src/librustc_metadata/rmeta/mod.rs b/src/librustc_metadata/rmeta/mod.rs
index 152bb257fa2..43a1515da32 100644
--- a/src/librustc_metadata/rmeta/mod.rs
+++ b/src/librustc_metadata/rmeta/mod.rs
@@ -305,7 +305,7 @@ enum EntryKind {
     Generator(hir::GeneratorKind),
     Trait(Lazy<TraitData>),
     Impl(Lazy<ImplData>),
-    Method(Lazy<MethodData>),
+    AssocFn(Lazy<AssocFnData>),
     AssocType(AssocContainer),
     AssocOpaqueTy(AssocContainer),
     AssocConst(AssocContainer, mir::ConstQualifs, Lazy<RenderedConst>),
@@ -392,7 +392,7 @@ impl AssocContainer {
 }
 
 #[derive(RustcEncodable, RustcDecodable)]
-struct MethodData {
+struct AssocFnData {
     fn_data: FnData,
     container: AssocContainer,
     has_self: bool,
diff --git a/src/librustc_mir/borrow_check/diagnostics/mutability_errors.rs b/src/librustc_mir/borrow_check/diagnostics/mutability_errors.rs
index 5d22ef46c41..c462f934148 100644
--- a/src/librustc_mir/borrow_check/diagnostics/mutability_errors.rs
+++ b/src/librustc_mir/borrow_check/diagnostics/mutability_errors.rs
@@ -485,7 +485,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                         }))
                         | Some(hir::Node::ImplItem(hir::ImplItem {
                             ident,
-                            kind: hir::ImplItemKind::Method(sig, _),
+                            kind: hir::ImplItemKind::Fn(sig, _),
                             ..
                         })) => Some(
                             arg_pos
@@ -527,7 +527,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 })
                 | hir::Node::ImplItem(hir::ImplItem {
                     ident,
-                    kind: hir::ImplItemKind::Method(sig, _),
+                    kind: hir::ImplItemKind::Fn(sig, _),
                     ..
                 }) => {
                     err.span_label(ident.span, "");
diff --git a/src/librustc_mir/borrow_check/diagnostics/region_name.rs b/src/librustc_mir/borrow_check/diagnostics/region_name.rs
index 01ace742876..7103fc596c9 100644
--- a/src/librustc_mir/borrow_check/diagnostics/region_name.rs
+++ b/src/librustc_mir/borrow_check/diagnostics/region_name.rs
@@ -651,7 +651,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
                 if gen_move.is_some() { " of generator" } else { " of closure" },
             ),
             hir::Node::ImplItem(hir::ImplItem {
-                kind: hir::ImplItemKind::Method(method_sig, _),
+                kind: hir::ImplItemKind::Fn(method_sig, _),
                 ..
             }) => (method_sig.decl.output.span(), ""),
             _ => (self.body.span, ""),
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index 862a7ef1e73..f56bef031a7 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -983,7 +983,7 @@ impl ItemLikeVisitor<'v> for RootCollector<'_, 'v> {
 
     fn visit_impl_item(&mut self, ii: &'v hir::ImplItem<'v>) {
         match ii.kind {
-            hir::ImplItemKind::Method(hir::FnSig { .. }, _) => {
+            hir::ImplItemKind::Fn(hir::FnSig { .. }, _) => {
                 let def_id = self.tcx.hir().local_def_id(ii.hir_id);
                 self.push_if_root(def_id);
             }
@@ -1088,9 +1088,9 @@ fn create_mono_items_for_default_impls<'tcx>(
                 let param_env = ty::ParamEnv::reveal_all();
                 let trait_ref = tcx.normalize_erasing_regions(param_env, trait_ref);
                 let overridden_methods: FxHashSet<_> =
-                    items.iter().map(|iiref| iiref.ident.modern()).collect();
+                    items.iter().map(|iiref| iiref.ident.normalize_to_macros_2_0()).collect();
                 for method in tcx.provided_trait_methods(trait_ref.def_id) {
-                    if overridden_methods.contains(&method.ident.modern()) {
+                    if overridden_methods.contains(&method.ident.normalize_to_macros_2_0()) {
                         continue;
                     }
 
diff --git a/src/librustc_mir/transform/check_consts/qualifs.rs b/src/librustc_mir/transform/check_consts/qualifs.rs
index baff8383c20..9359ec16533 100644
--- a/src/librustc_mir/transform/check_consts/qualifs.rs
+++ b/src/librustc_mir/transform/check_consts/qualifs.rs
@@ -1,7 +1,9 @@
-//! A copy of the `Qualif` trait in `qualify_consts.rs` that is suitable for the new validator.
+//! Structural const qualification.
+//!
+//! See the `Qualif` trait for more info.
 
 use rustc::mir::*;
-use rustc::ty::{self, Ty};
+use rustc::ty::{self, AdtDef, Ty};
 use rustc_span::DUMMY_SP;
 
 use super::Item as ConstCx;
@@ -14,11 +16,16 @@ pub fn in_any_value_of_ty(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>) -> ConstQualifs
 }
 
 /// A "qualif"(-ication) is a way to look for something "bad" in the MIR that would disqualify some
-/// code for promotion or prevent it from evaluating at compile time. So `return true` means
-/// "I found something bad, no reason to go on searching". `false` is only returned if we
-/// definitely cannot find anything bad anywhere.
+/// code for promotion or prevent it from evaluating at compile time.
 ///
-/// The default implementations proceed structurally.
+/// Normally, we would determine what qualifications apply to each type and error when an illegal
+/// operation is performed on such a type. However, this was found to be too imprecise, especially
+/// in the presence of `enum`s. If only a single variant of an enum has a certain qualification, we
+/// needn't reject code unless it actually constructs and operates on the qualifed variant.
+///
+/// To accomplish this, const-checking and promotion use a value-based analysis (as opposed to a
+/// type-based one). Qualifications propagate structurally across variables: If a local (or a
+/// projection of a local) is assigned a qualifed value, that local itself becomes qualifed.
 pub trait Qualif {
     /// The name of the file used to debug the dataflow analysis that computes this qualif.
     const ANALYSIS_NAME: &'static str;
@@ -26,157 +33,27 @@ pub trait Qualif {
     /// Whether this `Qualif` is cleared when a local is moved from.
     const IS_CLEARED_ON_MOVE: bool = false;
 
+    /// Extracts the field of `ConstQualifs` that corresponds to this `Qualif`.
     fn in_qualifs(qualifs: &ConstQualifs) -> bool;
 
-    /// Return the qualification that is (conservatively) correct for any value
-    /// of the type.
-    fn in_any_value_of_ty(_cx: &ConstCx<'_, 'tcx>, _ty: Ty<'tcx>) -> bool;
-
-    fn in_projection_structurally(
-        cx: &ConstCx<'_, 'tcx>,
-        per_local: &mut impl FnMut(Local) -> bool,
-        place: PlaceRef<'tcx>,
-    ) -> bool {
-        if let [proj_base @ .., elem] = place.projection {
-            let base_qualif = Self::in_place(
-                cx,
-                per_local,
-                PlaceRef { local: place.local, projection: proj_base },
-            );
-            let qualif = base_qualif
-                && Self::in_any_value_of_ty(
-                    cx,
-                    Place::ty_from(place.local, proj_base, *cx.body, cx.tcx)
-                        .projection_ty(cx.tcx, elem)
-                        .ty,
-                );
-            match elem {
-                ProjectionElem::Deref
-                | ProjectionElem::Subslice { .. }
-                | ProjectionElem::Field(..)
-                | ProjectionElem::ConstantIndex { .. }
-                | ProjectionElem::Downcast(..) => qualif,
-
-                ProjectionElem::Index(local) => qualif || per_local(*local),
-            }
-        } else {
-            bug!("This should be called if projection is not empty");
-        }
-    }
-
-    fn in_projection(
-        cx: &ConstCx<'_, 'tcx>,
-        per_local: &mut impl FnMut(Local) -> bool,
-        place: PlaceRef<'tcx>,
-    ) -> bool {
-        Self::in_projection_structurally(cx, per_local, place)
-    }
-
-    fn in_place(
-        cx: &ConstCx<'_, 'tcx>,
-        per_local: &mut impl FnMut(Local) -> bool,
-        place: PlaceRef<'tcx>,
-    ) -> bool {
-        match place {
-            PlaceRef { local, projection: [] } => per_local(local),
-            PlaceRef { local: _, projection: [.., _] } => Self::in_projection(cx, per_local, place),
-        }
-    }
-
-    fn in_operand(
-        cx: &ConstCx<'_, 'tcx>,
-        per_local: &mut impl FnMut(Local) -> bool,
-        operand: &Operand<'tcx>,
-    ) -> bool {
-        match *operand {
-            Operand::Copy(ref place) | Operand::Move(ref place) => {
-                Self::in_place(cx, per_local, place.as_ref())
-            }
-
-            Operand::Constant(ref constant) => {
-                // Check the qualifs of the value of `const` items.
-                if let ty::ConstKind::Unevaluated(def_id, _, promoted) = constant.literal.val {
-                    assert!(promoted.is_none());
-                    // Don't peek inside trait associated constants.
-                    if cx.tcx.trait_of_item(def_id).is_none() {
-                        let qualifs = cx.tcx.at(constant.span).mir_const_qualif(def_id);
-                        if !Self::in_qualifs(&qualifs) {
-                            return false;
-                        }
-
-                        // Just in case the type is more specific than
-                        // the definition, e.g., impl associated const
-                        // with type parameters, take it into account.
-                    }
-                }
-                // Otherwise use the qualifs of the type.
-                Self::in_any_value_of_ty(cx, constant.literal.ty)
-            }
-        }
-    }
-
-    fn in_rvalue_structurally(
-        cx: &ConstCx<'_, 'tcx>,
-        per_local: &mut impl FnMut(Local) -> bool,
-        rvalue: &Rvalue<'tcx>,
-    ) -> bool {
-        match *rvalue {
-            Rvalue::NullaryOp(..) => false,
-
-            Rvalue::Discriminant(ref place) | Rvalue::Len(ref place) => {
-                Self::in_place(cx, per_local, place.as_ref())
-            }
-
-            Rvalue::Use(ref operand)
-            | Rvalue::Repeat(ref operand, _)
-            | Rvalue::UnaryOp(_, ref operand)
-            | Rvalue::Cast(_, ref operand, _) => Self::in_operand(cx, per_local, operand),
-
-            Rvalue::BinaryOp(_, ref lhs, ref rhs)
-            | Rvalue::CheckedBinaryOp(_, ref lhs, ref rhs) => {
-                Self::in_operand(cx, per_local, lhs) || Self::in_operand(cx, per_local, rhs)
-            }
-
-            Rvalue::Ref(_, _, ref place) | Rvalue::AddressOf(_, ref place) => {
-                // Special-case reborrows to be more like a copy of the reference.
-                if let [proj_base @ .., ProjectionElem::Deref] = place.projection.as_ref() {
-                    let base_ty = Place::ty_from(place.local, proj_base, *cx.body, cx.tcx).ty;
-                    if let ty::Ref(..) = base_ty.kind {
-                        return Self::in_place(
-                            cx,
-                            per_local,
-                            PlaceRef { local: place.local, projection: proj_base },
-                        );
-                    }
-                }
-
-                Self::in_place(cx, per_local, place.as_ref())
-            }
-
-            Rvalue::Aggregate(_, ref operands) => {
-                operands.iter().any(|o| Self::in_operand(cx, per_local, o))
-            }
-        }
-    }
-
-    fn in_rvalue(
-        cx: &ConstCx<'_, 'tcx>,
-        per_local: &mut impl FnMut(Local) -> bool,
-        rvalue: &Rvalue<'tcx>,
-    ) -> bool {
-        Self::in_rvalue_structurally(cx, per_local, rvalue)
-    }
-
-    fn in_call(
-        cx: &ConstCx<'_, 'tcx>,
-        _per_local: &mut impl FnMut(Local) -> bool,
-        _callee: &Operand<'tcx>,
-        _args: &[Operand<'tcx>],
-        return_ty: Ty<'tcx>,
-    ) -> bool {
-        // Be conservative about the returned value of a const fn.
-        Self::in_any_value_of_ty(cx, return_ty)
-    }
+    /// Returns `true` if *any* value of the given type could possibly have this `Qualif`.
+    ///
+    /// This function determines `Qualif`s when we cannot do a value-based analysis. Since qualif
+    /// propagation is context-insenstive, this includes function arguments and values returned
+    /// from a call to another function.
+    ///
+    /// It also determines the `Qualif`s for primitive types.
+    fn in_any_value_of_ty(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>) -> bool;
+
+    /// Returns `true` if this `Qualif` is inherent to the given struct or enum.
+    ///
+    /// By default, `Qualif`s propagate into ADTs in a structural way: An ADT only becomes
+    /// qualified if part of it is assigned a value with that `Qualif`. However, some ADTs *always*
+    /// have a certain `Qualif`, regardless of whether their fields have it. For example, a type
+    /// with a custom `Drop` impl is inherently `NeedsDrop`.
+    ///
+    /// Returning `true` for `in_adt_inherently` but `false` for `in_any_value_of_ty` is unsound.
+    fn in_adt_inherently(cx: &ConstCx<'_, 'tcx>, adt: &AdtDef) -> bool;
 }
 
 /// Constant containing interior mutability (`UnsafeCell<T>`).
@@ -197,26 +74,10 @@ impl Qualif for HasMutInterior {
         !ty.is_freeze(cx.tcx, cx.param_env, DUMMY_SP)
     }
 
-    fn in_rvalue(
-        cx: &ConstCx<'_, 'tcx>,
-        per_local: &mut impl FnMut(Local) -> bool,
-        rvalue: &Rvalue<'tcx>,
-    ) -> bool {
-        match *rvalue {
-            Rvalue::Aggregate(ref kind, _) => {
-                if let AggregateKind::Adt(def, ..) = **kind {
-                    if Some(def.did) == cx.tcx.lang_items().unsafe_cell_type() {
-                        let ty = rvalue.ty(*cx.body, cx.tcx);
-                        assert_eq!(Self::in_any_value_of_ty(cx, ty), true);
-                        return true;
-                    }
-                }
-            }
-
-            _ => {}
-        }
-
-        Self::in_rvalue_structurally(cx, per_local, rvalue)
+    fn in_adt_inherently(cx: &ConstCx<'_, 'tcx>, adt: &AdtDef) -> bool {
+        // Exactly one type, `UnsafeCell`, has the `HasMutInterior` qualif inherently.
+        // It arises structurally for all other types.
+        Some(adt.did) == cx.tcx.lang_items().unsafe_cell_type()
     }
 }
 
@@ -238,19 +99,127 @@ impl Qualif for NeedsDrop {
         ty.needs_drop(cx.tcx, cx.param_env)
     }
 
-    fn in_rvalue(
-        cx: &ConstCx<'_, 'tcx>,
-        per_local: &mut impl FnMut(Local) -> bool,
-        rvalue: &Rvalue<'tcx>,
-    ) -> bool {
-        if let Rvalue::Aggregate(ref kind, _) = *rvalue {
+    fn in_adt_inherently(cx: &ConstCx<'_, 'tcx>, adt: &AdtDef) -> bool {
+        adt.has_dtor(cx.tcx)
+    }
+}
+
+// FIXME: Use `mir::visit::Visitor` for the `in_*` functions if/when it supports early return.
+
+/// Returns `true` if this `Rvalue` contains qualif `Q`.
+pub fn in_rvalue<Q, F>(cx: &ConstCx<'_, 'tcx>, in_local: &mut F, rvalue: &Rvalue<'tcx>) -> bool
+where
+    Q: Qualif,
+    F: FnMut(Local) -> bool,
+{
+    match rvalue {
+        Rvalue::NullaryOp(..) => Q::in_any_value_of_ty(cx, rvalue.ty(*cx.body, cx.tcx)),
+
+        Rvalue::Discriminant(place) | Rvalue::Len(place) => {
+            in_place::<Q, _>(cx, in_local, place.as_ref())
+        }
+
+        Rvalue::Use(operand)
+        | Rvalue::Repeat(operand, _)
+        | Rvalue::UnaryOp(_, operand)
+        | Rvalue::Cast(_, operand, _) => in_operand::<Q, _>(cx, in_local, operand),
+
+        Rvalue::BinaryOp(_, lhs, rhs) | Rvalue::CheckedBinaryOp(_, lhs, rhs) => {
+            in_operand::<Q, _>(cx, in_local, lhs) || in_operand::<Q, _>(cx, in_local, rhs)
+        }
+
+        Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) => {
+            // Special-case reborrows to be more like a copy of the reference.
+            if let &[ref proj_base @ .., ProjectionElem::Deref] = place.projection.as_ref() {
+                let base_ty = Place::ty_from(place.local, proj_base, *cx.body, cx.tcx).ty;
+                if let ty::Ref(..) = base_ty.kind {
+                    return in_place::<Q, _>(
+                        cx,
+                        in_local,
+                        PlaceRef { local: place.local, projection: proj_base },
+                    );
+                }
+            }
+
+            in_place::<Q, _>(cx, in_local, place.as_ref())
+        }
+
+        Rvalue::Aggregate(kind, operands) => {
+            // Return early if we know that the struct or enum being constructed is always
+            // qualified.
             if let AggregateKind::Adt(def, ..) = **kind {
-                if def.has_dtor(cx.tcx) {
+                if Q::in_adt_inherently(cx, def) {
                     return true;
                 }
             }
+
+            // Otherwise, proceed structurally...
+            operands.iter().any(|o| in_operand::<Q, _>(cx, in_local, o))
         }
+    }
+}
 
-        Self::in_rvalue_structurally(cx, per_local, rvalue)
+/// Returns `true` if this `Place` contains qualif `Q`.
+pub fn in_place<Q, F>(cx: &ConstCx<'_, 'tcx>, in_local: &mut F, place: PlaceRef<'tcx>) -> bool
+where
+    Q: Qualif,
+    F: FnMut(Local) -> bool,
+{
+    let mut projection = place.projection;
+    while let [ref proj_base @ .., proj_elem] = projection {
+        match *proj_elem {
+            ProjectionElem::Index(index) if in_local(index) => return true,
+
+            ProjectionElem::Deref
+            | ProjectionElem::Field(_, _)
+            | ProjectionElem::ConstantIndex { .. }
+            | ProjectionElem::Subslice { .. }
+            | ProjectionElem::Downcast(_, _)
+            | ProjectionElem::Index(_) => {}
+        }
+
+        let base_ty = Place::ty_from(place.local, proj_base, *cx.body, cx.tcx);
+        let proj_ty = base_ty.projection_ty(cx.tcx, proj_elem).ty;
+        if !Q::in_any_value_of_ty(cx, proj_ty) {
+            return false;
+        }
+
+        projection = proj_base;
+    }
+
+    assert!(projection.is_empty());
+    in_local(place.local)
+}
+
+/// Returns `true` if this `Operand` contains qualif `Q`.
+pub fn in_operand<Q, F>(cx: &ConstCx<'_, 'tcx>, in_local: &mut F, operand: &Operand<'tcx>) -> bool
+where
+    Q: Qualif,
+    F: FnMut(Local) -> bool,
+{
+    let constant = match operand {
+        Operand::Copy(place) | Operand::Move(place) => {
+            return in_place::<Q, _>(cx, in_local, place.as_ref());
+        }
+
+        Operand::Constant(c) => c,
+    };
+
+    // Check the qualifs of the value of `const` items.
+    if let ty::ConstKind::Unevaluated(def_id, _, promoted) = constant.literal.val {
+        assert!(promoted.is_none());
+        // Don't peek inside trait associated constants.
+        if cx.tcx.trait_of_item(def_id).is_none() {
+            let qualifs = cx.tcx.at(constant.span).mir_const_qualif(def_id);
+            if !Q::in_qualifs(&qualifs) {
+                return false;
+            }
+
+            // Just in case the type is more specific than
+            // the definition, e.g., impl associated const
+            // with type parameters, take it into account.
+        }
     }
+    // Otherwise use the qualifs of the type.
+    Q::in_any_value_of_ty(cx, constant.literal.ty)
 }
diff --git a/src/librustc_mir/transform/check_consts/resolver.rs b/src/librustc_mir/transform/check_consts/resolver.rs
index 3e14cc6d32a..e42f64b5c73 100644
--- a/src/librustc_mir/transform/check_consts/resolver.rs
+++ b/src/librustc_mir/transform/check_consts/resolver.rs
@@ -8,7 +8,7 @@ use rustc_index::bit_set::BitSet;
 
 use std::marker::PhantomData;
 
-use super::{Item, Qualif};
+use super::{qualifs, Item, Qualif};
 use crate::dataflow::{self as old_dataflow, generic as dataflow};
 
 /// A `Visitor` that propagates qualifs between locals. This defines the transfer function of
@@ -66,18 +66,15 @@ where
     fn apply_call_return_effect(
         &mut self,
         _block: BasicBlock,
-        func: &mir::Operand<'tcx>,
-        args: &[mir::Operand<'tcx>],
+        _func: &mir::Operand<'tcx>,
+        _args: &[mir::Operand<'tcx>],
         return_place: &mir::Place<'tcx>,
     ) {
+        // We cannot reason about another function's internals, so use conservative type-based
+        // qualification for the result of a function call.
         let return_ty = return_place.ty(*self.item.body, self.item.tcx).ty;
-        let qualif = Q::in_call(
-            self.item,
-            &mut |l| self.qualifs_per_local.contains(l),
-            func,
-            args,
-            return_ty,
-        );
+        let qualif = Q::in_any_value_of_ty(self.item, return_ty);
+
         if !return_place.is_indirect() {
             self.assign_qualif_direct(return_place, qualif);
         }
@@ -110,7 +107,11 @@ where
         rvalue: &mir::Rvalue<'tcx>,
         location: Location,
     ) {
-        let qualif = Q::in_rvalue(self.item, &mut |l| self.qualifs_per_local.contains(l), rvalue);
+        let qualif = qualifs::in_rvalue::<Q, _>(
+            self.item,
+            &mut |l| self.qualifs_per_local.contains(l),
+            rvalue,
+        );
         if !place.is_indirect() {
             self.assign_qualif_direct(place, qualif);
         }
@@ -125,8 +126,12 @@ where
         // here; that occurs in `apply_call_return_effect`.
 
         if let mir::TerminatorKind::DropAndReplace { value, location: dest, .. } = kind {
-            let qualif =
-                Q::in_operand(self.item, &mut |l| self.qualifs_per_local.contains(l), value);
+            let qualif = qualifs::in_operand::<Q, _>(
+                self.item,
+                &mut |l| self.qualifs_per_local.contains(l),
+                value,
+            );
+
             if !dest.is_indirect() {
                 self.assign_qualif_direct(dest, qualif);
             }
diff --git a/src/librustc_mir/transform/check_consts/validation.rs b/src/librustc_mir/transform/check_consts/validation.rs
index bfd97fcff3f..be461c0e03d 100644
--- a/src/librustc_mir/transform/check_consts/validation.rs
+++ b/src/librustc_mir/transform/check_consts/validation.rs
@@ -344,7 +344,7 @@ impl Visitor<'tcx> for Validator<'_, 'mir, 'tcx> {
             Rvalue::Ref(_, BorrowKind::Shared, ref place)
             | Rvalue::Ref(_, BorrowKind::Shallow, ref place)
             | Rvalue::AddressOf(Mutability::Not, ref place) => {
-                let borrowed_place_has_mut_interior = HasMutInterior::in_place(
+                let borrowed_place_has_mut_interior = qualifs::in_place::<HasMutInterior, _>(
                     &self.item,
                     &mut |local| self.qualifs.has_mut_interior(local, location),
                     place.as_ref(),
diff --git a/src/librustc_mir/transform/promote_consts.rs b/src/librustc_mir/transform/promote_consts.rs
index 7dd134a35d9..1336206e186 100644
--- a/src/librustc_mir/transform/promote_consts.rs
+++ b/src/librustc_mir/transform/promote_consts.rs
@@ -407,15 +407,17 @@ impl<'tcx> Validator<'_, 'tcx> {
 
     // FIXME(eddyb) maybe cache this?
     fn qualif_local<Q: qualifs::Qualif>(&self, local: Local) -> bool {
-        let per_local = &mut |l| self.qualif_local::<Q>(l);
-
         if let TempState::Defined { location: loc, .. } = self.temps[local] {
             let num_stmts = self.body[loc.block].statements.len();
 
             if loc.statement_index < num_stmts {
                 let statement = &self.body[loc.block].statements[loc.statement_index];
                 match &statement.kind {
-                    StatementKind::Assign(box (_, rhs)) => Q::in_rvalue(&self.item, per_local, rhs),
+                    StatementKind::Assign(box (_, rhs)) => qualifs::in_rvalue::<Q, _>(
+                        &self.item,
+                        &mut |l| self.qualif_local::<Q>(l),
+                        rhs,
+                    ),
                     _ => {
                         span_bug!(
                             statement.source_info.span,
@@ -427,9 +429,9 @@ impl<'tcx> Validator<'_, 'tcx> {
             } else {
                 let terminator = self.body[loc.block].terminator();
                 match &terminator.kind {
-                    TerminatorKind::Call { func, args, .. } => {
+                    TerminatorKind::Call { .. } => {
                         let return_ty = self.body.local_decls[local].ty;
-                        Q::in_call(&self.item, per_local, func, args, return_ty)
+                        Q::in_any_value_of_ty(&self.item, return_ty)
                     }
                     kind => {
                         span_bug!(terminator.source_info.span, "{:?} not promotable", kind);
diff --git a/src/librustc_mir_build/build/mod.rs b/src/librustc_mir_build/build/mod.rs
index c6bc8694295..821c4d68c7e 100644
--- a/src/librustc_mir_build/build/mod.rs
+++ b/src/librustc_mir_build/build/mod.rs
@@ -39,12 +39,12 @@ fn mir_build(tcx: TyCtxt<'_>, def_id: DefId) -> BodyAndCache<'_> {
             ..
         })
         | Node::ImplItem(hir::ImplItem {
-            kind: hir::ImplItemKind::Method(hir::FnSig { decl, .. }, body_id),
+            kind: hir::ImplItemKind::Fn(hir::FnSig { decl, .. }, body_id),
             ..
         })
         | Node::TraitItem(hir::TraitItem {
             kind:
-                hir::TraitItemKind::Fn(hir::FnSig { decl, .. }, hir::TraitMethod::Provided(body_id)),
+                hir::TraitItemKind::Fn(hir::FnSig { decl, .. }, hir::TraitFn::Provided(body_id)),
             ..
         }) => (*body_id, decl.output.span()),
         Node::Item(hir::Item { kind: hir::ItemKind::Static(ty, _, body_id), .. })
diff --git a/src/librustc_parse/parser/diagnostics.rs b/src/librustc_parse/parser/diagnostics.rs
index 7c1df531ad1..8e52bb16147 100644
--- a/src/librustc_parse/parser/diagnostics.rs
+++ b/src/librustc_parse/parser/diagnostics.rs
@@ -18,6 +18,7 @@ use rustc_span::{MultiSpan, Span, SpanSnippetError, DUMMY_SP};
 
 use log::{debug, trace};
 use std::mem;
+use std::path::PathBuf;
 
 const TURBOFISH: &str = "use `::<...>` instead of `<...>` to specify type arguments";
 
@@ -40,29 +41,15 @@ pub(super) fn dummy_arg(ident: Ident) -> Param {
 }
 
 pub enum Error {
-    FileNotFoundForModule {
-        mod_name: String,
-        default_path: String,
-        secondary_path: String,
-        dir_path: String,
-    },
-    DuplicatePaths {
-        mod_name: String,
-        default_path: String,
-        secondary_path: String,
-    },
+    FileNotFoundForModule { mod_name: String, default_path: PathBuf },
+    DuplicatePaths { mod_name: String, default_path: String, secondary_path: String },
     UselessDocComment,
 }
 
 impl Error {
     fn span_err(self, sp: impl Into<MultiSpan>, handler: &Handler) -> DiagnosticBuilder<'_> {
         match self {
-            Error::FileNotFoundForModule {
-                ref mod_name,
-                ref default_path,
-                ref secondary_path,
-                ref dir_path,
-            } => {
+            Error::FileNotFoundForModule { ref mod_name, ref default_path } => {
                 let mut err = struct_span_err!(
                     handler,
                     sp,
@@ -71,8 +58,9 @@ impl Error {
                     mod_name,
                 );
                 err.help(&format!(
-                    "name the file either {} or {} inside the directory \"{}\"",
-                    default_path, secondary_path, dir_path,
+                    "to create the module `{}`, create file \"{}\"",
+                    mod_name,
+                    default_path.display(),
                 ));
                 err
             }
diff --git a/src/librustc_parse/parser/item.rs b/src/librustc_parse/parser/item.rs
index fe5495fbf8a..e927bcd07e2 100644
--- a/src/librustc_parse/parser/item.rs
+++ b/src/librustc_parse/parser/item.rs
@@ -1260,7 +1260,7 @@ impl<'a> Parser<'a> {
         };
 
         self.sess.gated_spans.gate(sym::decl_macro, lo.to(self.prev_token.span));
-        Ok((ident, ItemKind::MacroDef(ast::MacroDef { body, legacy: false })))
+        Ok((ident, ItemKind::MacroDef(ast::MacroDef { body, macro_rules: false })))
     }
 
     /// Is this unambiguously the start of a `macro_rules! foo` item defnition?
@@ -1270,7 +1270,7 @@ impl<'a> Parser<'a> {
             && self.look_ahead(2, |t| t.is_ident())
     }
 
-    /// Parses a legacy `macro_rules! foo { ... }` declarative macro.
+    /// Parses a `macro_rules! foo { ... }` declarative macro.
     fn parse_item_macro_rules(&mut self, vis: &Visibility) -> PResult<'a, ItemInfo> {
         self.expect_keyword(kw::MacroRules)?; // `macro_rules`
         self.expect(&token::Not)?; // `!`
@@ -1280,7 +1280,7 @@ impl<'a> Parser<'a> {
         self.eat_semi_for_macro_if_needed(&body);
         self.complain_if_pub_macro(vis, true);
 
-        Ok((ident, ItemKind::MacroDef(ast::MacroDef { body, legacy: true })))
+        Ok((ident, ItemKind::MacroDef(ast::MacroDef { body, macro_rules: true })))
     }
 
     /// Item macro invocations or `macro_rules!` definitions need inherited visibility.
diff --git a/src/librustc_parse/parser/module.rs b/src/librustc_parse/parser/module.rs
index b436f1969bb..7b46601cc7d 100644
--- a/src/librustc_parse/parser/module.rs
+++ b/src/librustc_parse/parser/module.rs
@@ -234,12 +234,9 @@ impl<'a> Parser<'a> {
                 path: secondary_path,
                 directory_ownership: DirectoryOwnership::Owned { relative: None },
             }),
-            (false, false) => Err(Error::FileNotFoundForModule {
-                mod_name: mod_name.clone(),
-                default_path: default_path_str,
-                secondary_path: secondary_path_str,
-                dir_path: dir_path.display().to_string(),
-            }),
+            (false, false) => {
+                Err(Error::FileNotFoundForModule { mod_name: mod_name.clone(), default_path })
+            }
             (true, true) => Err(Error::DuplicatePaths {
                 mod_name: mod_name.clone(),
                 default_path: default_path_str,
diff --git a/src/librustc_passes/check_attr.rs b/src/librustc_passes/check_attr.rs
index 702872400c4..373b7c56d38 100644
--- a/src/librustc_passes/check_attr.rs
+++ b/src/librustc_passes/check_attr.rs
@@ -25,7 +25,7 @@ use rustc_span::Span;
 fn target_from_impl_item<'tcx>(tcx: TyCtxt<'tcx>, impl_item: &hir::ImplItem<'_>) -> Target {
     match impl_item.kind {
         hir::ImplItemKind::Const(..) => Target::AssocConst,
-        hir::ImplItemKind::Method(..) => {
+        hir::ImplItemKind::Fn(..) => {
             let parent_hir_id = tcx.hir().get_parent_item(impl_item.hir_id);
             let containing_item = tcx.hir().expect_item(parent_hir_id);
             let containing_impl_is_for_trait = match &containing_item.kind {
diff --git a/src/librustc_passes/dead.rs b/src/librustc_passes/dead.rs
index 7460b8e2fe9..587b57eb322 100644
--- a/src/librustc_passes/dead.rs
+++ b/src/librustc_passes/dead.rs
@@ -391,7 +391,7 @@ impl<'v, 'k, 'tcx> ItemLikeVisitor<'v> for LifeSeeder<'k, 'tcx> {
                     let trait_item = self.krate.trait_item(trait_item_ref.id);
                     match trait_item.kind {
                         hir::TraitItemKind::Const(_, Some(_))
-                        | hir::TraitItemKind::Fn(_, hir::TraitMethod::Provided(_)) => {
+                        | hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(_)) => {
                             if has_allow_dead_code_or_lang_attr(
                                 self.tcx,
                                 trait_item.hir_id,
@@ -661,7 +661,7 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
                 }
                 self.visit_nested_body(body_id)
             }
-            hir::ImplItemKind::Method(_, body_id) => {
+            hir::ImplItemKind::Fn(_, body_id) => {
                 if !self.symbol_is_live(impl_item.hir_id) {
                     let span = self.tcx.sess.source_map().def_span(impl_item.span);
                     self.warn_dead_code(
@@ -682,11 +682,11 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
         match trait_item.kind {
             hir::TraitItemKind::Const(_, Some(body_id))
-            | hir::TraitItemKind::Fn(_, hir::TraitMethod::Provided(body_id)) => {
+            | hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(body_id)) => {
                 self.visit_nested_body(body_id)
             }
             hir::TraitItemKind::Const(_, None)
-            | hir::TraitItemKind::Fn(_, hir::TraitMethod::Required(_))
+            | hir::TraitItemKind::Fn(_, hir::TraitFn::Required(_))
             | hir::TraitItemKind::Type(..) => {}
         }
     }
diff --git a/src/librustc_passes/reachable.rs b/src/librustc_passes/reachable.rs
index ad415ed8f62..4643add5ac3 100644
--- a/src/librustc_passes/reachable.rs
+++ b/src/librustc_passes/reachable.rs
@@ -53,7 +53,7 @@ fn method_might_be_inlined(
     if codegen_fn_attrs.requests_inline() || generics.requires_monomorphization(tcx) {
         return true;
     }
-    if let hir::ImplItemKind::Method(method_sig, _) = &impl_item.kind {
+    if let hir::ImplItemKind::Fn(method_sig, _) = &impl_item.kind {
         if method_sig.header.is_const() {
             return true;
         }
@@ -162,14 +162,14 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
             },
             Some(Node::TraitItem(trait_method)) => match trait_method.kind {
                 hir::TraitItemKind::Const(_, ref default) => default.is_some(),
-                hir::TraitItemKind::Fn(_, hir::TraitMethod::Provided(_)) => true,
-                hir::TraitItemKind::Fn(_, hir::TraitMethod::Required(_))
+                hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(_)) => true,
+                hir::TraitItemKind::Fn(_, hir::TraitFn::Required(_))
                 | hir::TraitItemKind::Type(..) => false,
             },
             Some(Node::ImplItem(impl_item)) => {
                 match impl_item.kind {
                     hir::ImplItemKind::Const(..) => true,
-                    hir::ImplItemKind::Method(..) => {
+                    hir::ImplItemKind::Fn(..) => {
                         let attrs = self.tcx.codegen_fn_attrs(def_id);
                         let generics = self.tcx.generics_of(def_id);
                         if generics.requires_monomorphization(self.tcx) || attrs.requests_inline() {
@@ -278,11 +278,11 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
             Node::TraitItem(trait_method) => {
                 match trait_method.kind {
                     hir::TraitItemKind::Const(_, None)
-                    | hir::TraitItemKind::Fn(_, hir::TraitMethod::Required(_)) => {
+                    | hir::TraitItemKind::Fn(_, hir::TraitFn::Required(_)) => {
                         // Keep going, nothing to get exported
                     }
                     hir::TraitItemKind::Const(_, Some(body_id))
-                    | hir::TraitItemKind::Fn(_, hir::TraitMethod::Provided(body_id)) => {
+                    | hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(body_id)) => {
                         self.visit_nested_body(body_id);
                     }
                     hir::TraitItemKind::Type(..) => {}
@@ -292,7 +292,7 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
                 hir::ImplItemKind::Const(_, body) => {
                     self.visit_nested_body(body);
                 }
-                hir::ImplItemKind::Method(_, body) => {
+                hir::ImplItemKind::Fn(_, body) => {
                     let did = self.tcx.hir().get_parent_did(search_item);
                     if method_might_be_inlined(self.tcx, impl_item, did) {
                         self.visit_nested_body(body)
diff --git a/src/librustc_privacy/lib.rs b/src/librustc_privacy/lib.rs
index 28a2987301f..108a8006409 100644
--- a/src/librustc_privacy/lib.rs
+++ b/src/librustc_privacy/lib.rs
@@ -920,7 +920,7 @@ impl Visitor<'tcx> for EmbargoVisitor<'tcx> {
     }
 
     fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef<'tcx>) {
-        if attr::find_transparency(&md.attrs, md.ast.legacy).0 != Transparency::Opaque {
+        if attr::find_transparency(&md.attrs, md.ast.macro_rules).0 != Transparency::Opaque {
             self.update(md.hir_id, Some(AccessLevel::Public));
             return;
         }
@@ -1556,7 +1556,7 @@ impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
                     || items.iter().any(|impl_item_ref| {
                         let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
                         match impl_item.kind {
-                            hir::ImplItemKind::Const(..) | hir::ImplItemKind::Method(..) => {
+                            hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => {
                                 self.access_levels.is_reachable(impl_item_ref.id.hir_id)
                             }
                             hir::ImplItemKind::OpaqueTy(..) | hir::ImplItemKind::TyAlias(_) => {
@@ -1578,8 +1578,7 @@ impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
                                 // types in private items.
                                 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
                                 match impl_item.kind {
-                                    hir::ImplItemKind::Const(..)
-                                    | hir::ImplItemKind::Method(..)
+                                    hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
                                         if self
                                             .item_is_public(&impl_item.hir_id, &impl_item.vis) =>
                                     {
diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs
index 0c6edd3e47d..ce3b1233a74 100644
--- a/src/librustc_resolve/build_reduced_graph.rs
+++ b/src/librustc_resolve/build_reduced_graph.rs
@@ -7,7 +7,7 @@
 
 use crate::def_collector::collect_definitions;
 use crate::imports::{Import, ImportKind};
-use crate::macros::{LegacyBinding, LegacyScope};
+use crate::macros::{MacroRulesBinding, MacroRulesScope};
 use crate::Namespace::{self, MacroNS, TypeNS, ValueNS};
 use crate::{CrateLint, Determinacy, PathResult, ResolutionError, VisResolutionError};
 use crate::{
@@ -165,11 +165,11 @@ impl<'a> Resolver<'a> {
         &mut self,
         fragment: &AstFragment,
         parent_scope: ParentScope<'a>,
-    ) -> LegacyScope<'a> {
+    ) -> MacroRulesScope<'a> {
         collect_definitions(&mut self.definitions, fragment, parent_scope.expansion);
         let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope };
         fragment.visit_with(&mut visitor);
-        visitor.parent_scope.legacy
+        visitor.parent_scope.macro_rules
     }
 
     crate fn build_reduced_graph_external(&mut self, module: Module<'a>) {
@@ -624,7 +624,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                     self.r.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX })
                 };
 
-                let used = self.process_legacy_macro_imports(item, module);
+                let used = self.process_macro_use_imports(item, module);
                 let binding =
                     (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
                 let import = self.r.arenas.alloc_import(Import {
@@ -645,7 +645,8 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 self.r.potentially_unused_imports.push(import);
                 let imported_binding = self.r.import(binding, import);
                 if ptr::eq(parent, self.r.graph_root) {
-                    if let Some(entry) = self.r.extern_prelude.get(&ident.modern()) {
+                    if let Some(entry) = self.r.extern_prelude.get(&ident.normalize_to_macros_2_0())
+                    {
                         if expansion != ExpnId::root()
                             && orig_name.is_some()
                             && entry.extern_crate_item.is_none()
@@ -656,10 +657,12 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                         }
                     }
                     let entry =
-                        self.r.extern_prelude.entry(ident.modern()).or_insert(ExternPreludeEntry {
-                            extern_crate_item: None,
-                            introduced_by_item: true,
-                        });
+                        self.r.extern_prelude.entry(ident.normalize_to_macros_2_0()).or_insert(
+                            ExternPreludeEntry {
+                                extern_crate_item: None,
+                                introduced_by_item: true,
+                            },
+                        );
                     entry.extern_crate_item = Some(imported_binding);
                     if orig_name.is_some() {
                         entry.introduced_by_item = true;
@@ -913,7 +916,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         }
     }
 
-    fn legacy_import_macro(
+    fn add_macro_use_binding(
         &mut self,
         name: ast::Name,
         binding: &'a NameBinding<'a>,
@@ -929,7 +932,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
     }
 
     /// Returns `true` if we should consider the underlying `extern crate` to be used.
-    fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>) -> bool {
+    fn process_macro_use_imports(&mut self, item: &Item, module: Module<'a>) -> bool {
         let mut import_all = None;
         let mut single_imports = Vec::new();
         for attr in &item.attrs {
@@ -1004,7 +1007,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             module.for_each_child(self, |this, ident, ns, binding| {
                 if ns == MacroNS {
                     let imported_binding = this.r.import(binding, import);
-                    this.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
+                    this.add_macro_use_binding(ident.name, imported_binding, span, allow_shadowing);
                 }
             });
         } else {
@@ -1021,7 +1024,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                     let import = macro_use_import(self, ident.span);
                     self.r.potentially_unused_imports.push(import);
                     let imported_binding = self.r.import(binding, import);
-                    self.legacy_import_macro(
+                    self.add_macro_use_binding(
                         ident.name,
                         imported_binding,
                         ident.span,
@@ -1060,7 +1063,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         false
     }
 
-    fn visit_invoc(&mut self, id: NodeId) -> LegacyScope<'a> {
+    fn visit_invoc(&mut self, id: NodeId) -> MacroRulesScope<'a> {
         let invoc_id = id.placeholder_to_expn_id();
 
         self.parent_scope.module.unexpanded_invocations.borrow_mut().insert(invoc_id);
@@ -1068,7 +1071,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         let old_parent_scope = self.r.invocation_parent_scopes.insert(invoc_id, self.parent_scope);
         assert!(old_parent_scope.is_none(), "invocation data is reset for an invocation");
 
-        LegacyScope::Invocation(invoc_id)
+        MacroRulesScope::Invocation(invoc_id)
     }
 
     fn proc_macro_stub(item: &ast::Item) -> Option<(MacroKind, Ident, Span)> {
@@ -1095,20 +1098,20 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         }
     }
 
-    fn define_macro(&mut self, item: &ast::Item) -> LegacyScope<'a> {
+    fn define_macro(&mut self, item: &ast::Item) -> MacroRulesScope<'a> {
         let parent_scope = self.parent_scope;
         let expansion = parent_scope.expansion;
-        let (ext, ident, span, is_legacy) = match &item.kind {
+        let (ext, ident, span, macro_rules) = match &item.kind {
             ItemKind::MacroDef(def) => {
                 let ext = Lrc::new(self.r.compile_macro(item, self.r.session.edition()));
-                (ext, item.ident, item.span, def.legacy)
+                (ext, item.ident, item.span, def.macro_rules)
             }
             ItemKind::Fn(..) => match Self::proc_macro_stub(item) {
                 Some((macro_kind, ident, span)) => {
                     self.r.proc_macro_stubs.insert(item.id);
                     (self.r.dummy_ext(macro_kind), ident, span, false)
                 }
-                None => return parent_scope.legacy,
+                None => return parent_scope.macro_rules,
             },
             _ => unreachable!(),
         };
@@ -1118,8 +1121,8 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         self.r.macro_map.insert(def_id, ext);
         self.r.local_macro_def_scopes.insert(item.id, parent_scope.module);
 
-        if is_legacy {
-            let ident = ident.modern();
+        if macro_rules {
+            let ident = ident.normalize_to_macros_2_0();
             self.r.macro_names.insert(ident);
             let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export);
             let vis = if is_macro_export {
@@ -1137,8 +1140,8 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 self.r.check_reserved_macro_name(ident, res);
                 self.insert_unused_macro(ident, item.id, span);
             }
-            LegacyScope::Binding(self.r.arenas.alloc_legacy_binding(LegacyBinding {
-                parent_legacy_scope: parent_scope.legacy,
+            MacroRulesScope::Binding(self.r.arenas.alloc_macro_rules_binding(MacroRulesBinding {
+                parent_macro_rules_scope: parent_scope.macro_rules,
                 binding,
                 ident,
             }))
@@ -1149,7 +1152,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 self.insert_unused_macro(ident, item.id, span);
             }
             self.r.define(module, ident, MacroNS, (res, vis, span, expansion));
-            self.parent_scope.legacy
+            self.parent_scope.macro_rules
         }
     }
 }
@@ -1174,29 +1177,29 @@ impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
     fn visit_item(&mut self, item: &'b Item) {
         let macro_use = match item.kind {
             ItemKind::MacroDef(..) => {
-                self.parent_scope.legacy = self.define_macro(item);
+                self.parent_scope.macro_rules = self.define_macro(item);
                 return;
             }
             ItemKind::MacCall(..) => {
-                self.parent_scope.legacy = self.visit_invoc(item.id);
+                self.parent_scope.macro_rules = self.visit_invoc(item.id);
                 return;
             }
             ItemKind::Mod(..) => self.contains_macro_use(&item.attrs),
             _ => false,
         };
         let orig_current_module = self.parent_scope.module;
-        let orig_current_legacy_scope = self.parent_scope.legacy;
+        let orig_current_macro_rules_scope = self.parent_scope.macro_rules;
         self.build_reduced_graph_for_item(item);
         visit::walk_item(self, item);
         self.parent_scope.module = orig_current_module;
         if !macro_use {
-            self.parent_scope.legacy = orig_current_legacy_scope;
+            self.parent_scope.macro_rules = orig_current_macro_rules_scope;
         }
     }
 
     fn visit_stmt(&mut self, stmt: &'b ast::Stmt) {
         if let ast::StmtKind::MacCall(..) = stmt.kind {
-            self.parent_scope.legacy = self.visit_invoc(stmt.id);
+            self.parent_scope.macro_rules = self.visit_invoc(stmt.id);
         } else {
             visit::walk_stmt(self, stmt);
         }
@@ -1214,11 +1217,11 @@ impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
 
     fn visit_block(&mut self, block: &'b Block) {
         let orig_current_module = self.parent_scope.module;
-        let orig_current_legacy_scope = self.parent_scope.legacy;
+        let orig_current_macro_rules_scope = self.parent_scope.macro_rules;
         self.build_reduced_graph_for_block(block);
         visit::walk_block(self, block);
         self.parent_scope.module = orig_current_module;
-        self.parent_scope.legacy = orig_current_legacy_scope;
+        self.parent_scope.macro_rules = orig_current_macro_rules_scope;
     }
 
     fn visit_assoc_item(&mut self, item: &'b AssocItem, ctxt: AssocCtxt) {
diff --git a/src/librustc_resolve/diagnostics.rs b/src/librustc_resolve/diagnostics.rs
index 47a05ec90d4..63fbc800ff7 100644
--- a/src/librustc_resolve/diagnostics.rs
+++ b/src/librustc_resolve/diagnostics.rs
@@ -21,7 +21,9 @@ use rustc_span::{BytePos, MultiSpan, Span};
 use crate::imports::{Import, ImportKind, ImportResolver};
 use crate::path_names_to_string;
 use crate::{AmbiguityError, AmbiguityErrorMisc, AmbiguityKind};
-use crate::{BindingError, CrateLint, HasGenericParams, LegacyScope, Module, ModuleOrUniformRoot};
+use crate::{
+    BindingError, CrateLint, HasGenericParams, MacroRulesScope, Module, ModuleOrUniformRoot,
+};
 use crate::{NameBinding, NameBindingKind, PrivacyError, VisResolutionError};
 use crate::{ParentScope, PathResult, ResolutionError, Resolver, Scope, ScopeSet, Segment};
 
@@ -498,12 +500,12 @@ impl<'a> Resolver<'a> {
                         }
                     }
                 }
-                Scope::MacroRules(legacy_scope) => {
-                    if let LegacyScope::Binding(legacy_binding) = legacy_scope {
-                        let res = legacy_binding.binding.res();
+                Scope::MacroRules(macro_rules_scope) => {
+                    if let MacroRulesScope::Binding(macro_rules_binding) = macro_rules_scope {
+                        let res = macro_rules_binding.binding.res();
                         if filter_fn(res) {
                             suggestions
-                                .push(TypoSuggestion::from_res(legacy_binding.ident.name, res))
+                                .push(TypoSuggestion::from_res(macro_rules_binding.ident.name, res))
                         }
                     }
                 }
@@ -756,7 +758,7 @@ impl<'a> Resolver<'a> {
             let msg = format!("unsafe traits like `{}` should be implemented explicitly", ident);
             err.span_note(ident.span, &msg);
         }
-        if self.macro_names.contains(&ident.modern()) {
+        if self.macro_names.contains(&ident.normalize_to_macros_2_0()) {
             err.help("have you added the `#[macro_use]` on the module/import?");
         }
     }
diff --git a/src/librustc_resolve/imports.rs b/src/librustc_resolve/imports.rs
index 485b86636a0..681c0392118 100644
--- a/src/librustc_resolve/imports.rs
+++ b/src/librustc_resolve/imports.rs
@@ -416,7 +416,8 @@ impl<'a> Resolver<'a> {
                 None => return Err((Undetermined, Weak::Yes)),
             };
             let tmp_parent_scope;
-            let (mut adjusted_parent_scope, mut ident) = (parent_scope, ident.modern());
+            let (mut adjusted_parent_scope, mut ident) =
+                (parent_scope, ident.normalize_to_macros_2_0());
             match ident.span.glob_adjust(module.expansion, glob_import.span) {
                 Some(Some(def)) => {
                     tmp_parent_scope =
diff --git a/src/librustc_resolve/late.rs b/src/librustc_resolve/late.rs
index 7efd9e90ceb..867aa8c6321 100644
--- a/src/librustc_resolve/late.rs
+++ b/src/librustc_resolve/late.rs
@@ -935,7 +935,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 _ => unreachable!(),
             };
 
-            let ident = param.ident.modern();
+            let ident = param.ident.normalize_to_macros_2_0();
             debug!("with_generic_param_rib: {}", param.id);
 
             if seen_bindings.contains_key(&ident) {
@@ -1464,7 +1464,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         // Add the binding to the local ribs, if it doesn't already exist in the bindings map.
         // (We must not add it if it's in the bindings map because that breaks the assumptions
         // later passes make about or-patterns.)
-        let ident = ident.modern_and_legacy();
+        let ident = ident.normalize_to_macro_rules();
 
         let mut bound_iter = bindings.iter().filter(|(_, set)| set.contains(&ident));
         // Already bound in a product pattern? e.g. `(a, a)` which is not allowed.
@@ -1873,7 +1873,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 self.diagnostic_metadata.unused_labels.insert(id, label.ident.span);
             }
             self.with_label_rib(NormalRibKind, |this| {
-                let ident = label.ident.modern_and_legacy();
+                let ident = label.ident.normalize_to_macro_rules();
                 this.label_ribs.last_mut().unwrap().bindings.insert(ident, id);
                 f(this);
             });
@@ -1949,7 +1949,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
 
             ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
                 let node_id = self.search_label(label.ident, |rib, ident| {
-                    rib.bindings.get(&ident.modern_and_legacy()).cloned()
+                    rib.bindings.get(&ident.normalize_to_macro_rules()).cloned()
                 });
                 match node_id {
                     None => {
@@ -2115,7 +2115,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
             }
         }
 
-        ident.span = ident.span.modern();
+        ident.span = ident.span.normalize_to_macros_2_0();
         let mut search_module = self.parent_scope.module;
         loop {
             self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
diff --git a/src/librustc_resolve/late/lifetimes.rs b/src/librustc_resolve/late/lifetimes.rs
index ddee73e72a4..c015841cdc5 100644
--- a/src/librustc_resolve/late/lifetimes.rs
+++ b/src/librustc_resolve/late/lifetimes.rs
@@ -62,7 +62,7 @@ impl RegionExt for Region {
         let def_id = hir_map.local_def_id(param.hir_id);
         let origin = LifetimeDefOrigin::from_param(param);
         debug!("Region::early: index={} def_id={:?}", i, def_id);
-        (param.name.modern(), Region::EarlyBound(i, def_id, origin))
+        (param.name.normalize_to_macros_2_0(), Region::EarlyBound(i, def_id, origin))
     }
 
     fn late(hir_map: &Map<'_>, param: &GenericParam<'_>) -> (ParamName, Region) {
@@ -73,7 +73,7 @@ impl RegionExt for Region {
             "Region::late: param={:?} depth={:?} def_id={:?} origin={:?}",
             param, depth, def_id, origin,
         );
-        (param.name.modern(), Region::LateBound(depth, def_id, origin))
+        (param.name.normalize_to_macros_2_0(), Region::LateBound(depth, def_id, origin))
     }
 
     fn late_anon(index: &Cell<u32>) -> Region {
@@ -771,7 +771,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         use self::hir::ImplItemKind::*;
         self.missing_named_lifetime_spots.push((&impl_item.generics).into());
         match impl_item.kind {
-            Method(ref sig, _) => {
+            Fn(ref sig, _) => {
                 let tcx = self.tcx;
                 self.visit_early_late(
                     Some(tcx.hir().get_parent_item(impl_item.hir_id)),
@@ -1174,7 +1174,9 @@ fn extract_labels(ctxt: &mut LifetimeContext<'_, '_>, body: &hir::Body<'_>) {
 
                 Scope::Binder { ref lifetimes, s, .. } => {
                     // FIXME (#24278): non-hygienic comparison
-                    if let Some(def) = lifetimes.get(&hir::ParamName::Plain(label.modern())) {
+                    if let Some(def) =
+                        lifetimes.get(&hir::ParamName::Plain(label.normalize_to_macros_2_0()))
+                    {
                         let hir_id = tcx.hir().as_local_hir_id(def.id().unwrap()).unwrap();
 
                         signal_shadowing_problem(
@@ -1253,7 +1255,7 @@ fn object_lifetime_defaults_for_item(
     fn add_bounds(set: &mut Set1<hir::LifetimeName>, bounds: &[hir::GenericBound<'_>]) {
         for bound in bounds {
             if let hir::GenericBound::Outlives(ref lifetime) = *bound {
-                set.insert(lifetime.name.modern());
+                set.insert(lifetime.name.normalize_to_macros_2_0());
             }
         }
     }
@@ -1466,7 +1468,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                         }
                     }
                     Node::ImplItem(impl_item) => {
-                        if let hir::ImplItemKind::Method(sig, _) = &impl_item.kind {
+                        if let hir::ImplItemKind::Fn(sig, _) = &impl_item.kind {
                             find_arg_use_span(sig.decl.inputs);
                         }
                     }
@@ -1791,7 +1793,8 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                 Scope::Binder { ref lifetimes, s, .. } => {
                     match lifetime_ref.name {
                         LifetimeName::Param(param_name) => {
-                            if let Some(&def) = lifetimes.get(&param_name.modern()) {
+                            if let Some(&def) = lifetimes.get(&param_name.normalize_to_macros_2_0())
+                            {
                                 break Some(def.shifted(late_depth));
                             }
                         }
@@ -1818,9 +1821,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                     | Node::TraitItem(&hir::TraitItem {
                         kind: hir::TraitItemKind::Fn(..), ..
                     })
-                    | Node::ImplItem(&hir::ImplItem {
-                        kind: hir::ImplItemKind::Method(..), ..
-                    }) => {
+                    | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. }) => {
                         let scope = self.tcx.hir().local_def_id(fn_id);
                         def = Region::Free(scope, def.id().unwrap());
                     }
@@ -2100,12 +2101,12 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                         trait_items.iter().find(|ti| ti.id.hir_id == parent).map(|ti| ti.kind);
                 }
                 match *m {
-                    hir::TraitMethod::Required(_) => None,
-                    hir::TraitMethod::Provided(body) => Some(body),
+                    hir::TraitFn::Required(_) => None,
+                    hir::TraitFn::Provided(body) => Some(body),
                 }
             }
 
-            Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Method(_, body), .. }) => {
+            Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Fn(_, body), .. }) => {
                 if let hir::ItemKind::Impl { ref self_ty, ref items, .. } =
                     self.tcx.hir().expect_item(self.tcx.hir().get_parent_item(parent)).kind
                 {
@@ -2544,7 +2545,9 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         let lifetimes: Vec<_> = params
             .iter()
             .filter_map(|param| match param.kind {
-                GenericParamKind::Lifetime { .. } => Some((param, param.name.modern())),
+                GenericParamKind::Lifetime { .. } => {
+                    Some((param, param.name.normalize_to_macros_2_0()))
+                }
                 _ => None,
             })
             .collect();
@@ -2661,7 +2664,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                 }
 
                 Scope::Binder { ref lifetimes, s, .. } => {
-                    if let Some(&def) = lifetimes.get(&param.name.modern()) {
+                    if let Some(&def) = lifetimes.get(&param.name.normalize_to_macros_2_0()) {
                         let hir_id = self.tcx.hir().as_local_hir_id(def.id().unwrap()).unwrap();
 
                         signal_shadowing_problem(
@@ -2799,7 +2802,7 @@ fn insert_late_bound_lifetimes(
                 // `'a: 'b` means both `'a` and `'b` are referenced
                 appears_in_where_clause
                     .regions
-                    .insert(hir::LifetimeName::Param(param.name.modern()));
+                    .insert(hir::LifetimeName::Param(param.name.normalize_to_macros_2_0()));
             }
         }
     }
@@ -2821,7 +2824,7 @@ fn insert_late_bound_lifetimes(
             hir::GenericParamKind::Type { .. } | hir::GenericParamKind::Const { .. } => continue,
         }
 
-        let lt_name = hir::LifetimeName::Param(param.name.modern());
+        let lt_name = hir::LifetimeName::Param(param.name.normalize_to_macros_2_0());
         // appears in the where clauses? early-bound.
         if appears_in_where_clause.regions.contains(&lt_name) {
             continue;
@@ -2885,7 +2888,7 @@ fn insert_late_bound_lifetimes(
         }
 
         fn visit_lifetime(&mut self, lifetime_ref: &'v hir::Lifetime) {
-            self.regions.insert(lifetime_ref.name.modern());
+            self.regions.insert(lifetime_ref.name.normalize_to_macros_2_0());
         }
     }
 
@@ -2902,7 +2905,7 @@ fn insert_late_bound_lifetimes(
         }
 
         fn visit_lifetime(&mut self, lifetime_ref: &'v hir::Lifetime) {
-            self.regions.insert(lifetime_ref.name.modern());
+            self.regions.insert(lifetime_ref.name.normalize_to_macros_2_0());
         }
     }
 }
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index 37a800a0b7b..05d0f206450 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -58,7 +58,7 @@ use diagnostics::{extend_span_to_previous_binding, find_span_of_binding_until_ne
 use diagnostics::{ImportSuggestion, Suggestion};
 use imports::{Import, ImportKind, ImportResolver, NameResolution};
 use late::{HasGenericParams, PathSource, Rib, RibKind::*};
-use macros::{LegacyBinding, LegacyScope};
+use macros::{MacroRulesBinding, MacroRulesScope};
 
 type Res = def::Res<NodeId>;
 
@@ -94,7 +94,7 @@ impl Determinacy {
 enum Scope<'a> {
     DeriveHelpers(ExpnId),
     DeriveHelpersCompat,
-    MacroRules(LegacyScope<'a>),
+    MacroRules(MacroRulesScope<'a>),
     CrateRoot,
     Module(Module<'a>),
     RegisteredAttrs,
@@ -127,7 +127,7 @@ enum ScopeSet {
 pub struct ParentScope<'a> {
     module: Module<'a>,
     expansion: ExpnId,
-    legacy: LegacyScope<'a>,
+    macro_rules: MacroRulesScope<'a>,
     derives: &'a [ast::Path],
 }
 
@@ -135,7 +135,12 @@ impl<'a> ParentScope<'a> {
     /// Creates a parent scope with the passed argument used as the module scope component,
     /// and other scope components set to default empty values.
     pub fn module(module: Module<'a>) -> ParentScope<'a> {
-        ParentScope { module, expansion: ExpnId::root(), legacy: LegacyScope::Empty, derives: &[] }
+        ParentScope {
+            module,
+            expansion: ExpnId::root(),
+            macro_rules: MacroRulesScope::Empty,
+            derives: &[],
+        }
     }
 }
 
@@ -419,7 +424,7 @@ impl ModuleKind {
 /// program) if all but one of them come from glob imports.
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 struct BindingKey {
-    /// The identifier for the binding, aways the `modern` version of the
+    /// The identifier for the binding, aways the `normalize_to_macros_2_0` version of the
     /// identifier.
     ident: Ident,
     ns: Namespace,
@@ -613,7 +618,7 @@ enum AmbiguityKind {
     Import,
     BuiltinAttr,
     DeriveHelper,
-    LegacyVsModern,
+    MacroRulesVsModularized,
     GlobVsOuter,
     GlobVsGlob,
     GlobVsExpanded,
@@ -626,7 +631,9 @@ impl AmbiguityKind {
             AmbiguityKind::Import => "name vs any other name during import resolution",
             AmbiguityKind::BuiltinAttr => "built-in attribute vs any other name",
             AmbiguityKind::DeriveHelper => "derive helper attribute vs any other name",
-            AmbiguityKind::LegacyVsModern => "`macro_rules` vs non-`macro_rules` from other module",
+            AmbiguityKind::MacroRulesVsModularized => {
+                "`macro_rules` vs non-`macro_rules` from other module"
+            }
             AmbiguityKind::GlobVsOuter => {
                 "glob import vs any other name from outer scope during import/macro resolution"
             }
@@ -930,9 +937,9 @@ pub struct Resolver<'a> {
     /// Parent scopes in which the macros were invoked.
     /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere.
     invocation_parent_scopes: FxHashMap<ExpnId, ParentScope<'a>>,
-    /// Legacy scopes *produced* by expanding the macro invocations,
+    /// `macro_rules` scopes *produced* by expanding the macro invocations,
     /// include all the `macro_rules` items and other invocations generated by them.
-    output_legacy_scopes: FxHashMap<ExpnId, LegacyScope<'a>>,
+    output_macro_rules_scopes: FxHashMap<ExpnId, MacroRulesScope<'a>>,
     /// Helper attributes that are in scope for the given expansion.
     helper_attrs: FxHashMap<ExpnId, Vec<Ident>>,
 
@@ -965,7 +972,7 @@ pub struct ResolverArenas<'a> {
     name_bindings: arena::TypedArena<NameBinding<'a>>,
     imports: arena::TypedArena<Import<'a>>,
     name_resolutions: arena::TypedArena<RefCell<NameResolution<'a>>>,
-    legacy_bindings: arena::TypedArena<LegacyBinding<'a>>,
+    macro_rules_bindings: arena::TypedArena<MacroRulesBinding<'a>>,
     ast_paths: arena::TypedArena<ast::Path>,
 }
 
@@ -989,8 +996,11 @@ impl<'a> ResolverArenas<'a> {
     fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
         self.name_resolutions.alloc(Default::default())
     }
-    fn alloc_legacy_binding(&'a self, binding: LegacyBinding<'a>) -> &'a LegacyBinding<'a> {
-        self.legacy_bindings.alloc(binding)
+    fn alloc_macro_rules_binding(
+        &'a self,
+        binding: MacroRulesBinding<'a>,
+    ) -> &'a MacroRulesBinding<'a> {
+        self.macro_rules_bindings.alloc(binding)
     }
     fn alloc_ast_paths(&'a self, paths: &[ast::Path]) -> &'a [ast::Path] {
         self.ast_paths.alloc_from_iter(paths.iter().cloned())
@@ -1210,7 +1220,7 @@ impl<'a> Resolver<'a> {
             dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(session.edition())),
             non_macro_attrs: [non_macro_attr(false), non_macro_attr(true)],
             invocation_parent_scopes,
-            output_legacy_scopes: Default::default(),
+            output_macro_rules_scopes: Default::default(),
             helper_attrs: Default::default(),
             macro_defs,
             local_macro_def_scopes: FxHashMap::default(),
@@ -1352,7 +1362,7 @@ impl<'a> Resolver<'a> {
     }
 
     fn new_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey {
-        let ident = ident.modern();
+        let ident = ident.normalize_to_macros_2_0();
         let disambiguator = if ident.name == kw::Underscore {
             self.underscore_disambiguator += 1;
             self.underscore_disambiguator
@@ -1403,7 +1413,7 @@ impl<'a> Resolver<'a> {
             // Avoid marking `extern crate` items that refer to a name from extern prelude,
             // but not introduce it, as used if they are accessed from lexical scope.
             if is_lexical_scope {
-                if let Some(entry) = self.extern_prelude.get(&ident.modern()) {
+                if let Some(entry) = self.extern_prelude.get(&ident.normalize_to_macros_2_0()) {
                     if let Some(crate_item) = entry.extern_crate_item {
                         if ptr::eq(used_binding, crate_item) && !entry.introduced_by_item {
                             return;
@@ -1465,7 +1475,7 @@ impl<'a> Resolver<'a> {
         //    derives (you need to resolve the derive first to add helpers into scope), but they
         //    should be available before the derive is expanded for compatibility.
         //    It's mess in general, so we are being conservative for now.
-        // 1-3. `macro_rules` (open, not controlled), loop through legacy scopes. Have higher
+        // 1-3. `macro_rules` (open, not controlled), loop through `macro_rules` scopes. Have higher
         //    priority than prelude macros, but create ambiguities with macros in modules.
         // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
         //    (open, not controlled). Have higher priority than prelude macros, but create
@@ -1490,7 +1500,7 @@ impl<'a> Resolver<'a> {
             TypeNS | ValueNS => Scope::Module(module),
             MacroNS => Scope::DeriveHelpers(parent_scope.expansion),
         };
-        let mut ident = ident.modern();
+        let mut ident = ident.normalize_to_macros_2_0();
         let mut use_prelude = !module.no_implicit_prelude;
 
         loop {
@@ -1530,16 +1540,18 @@ impl<'a> Resolver<'a> {
                     }
                 }
                 Scope::DeriveHelpers(..) => Scope::DeriveHelpersCompat,
-                Scope::DeriveHelpersCompat => Scope::MacroRules(parent_scope.legacy),
-                Scope::MacroRules(legacy_scope) => match legacy_scope {
-                    LegacyScope::Binding(binding) => Scope::MacroRules(binding.parent_legacy_scope),
-                    LegacyScope::Invocation(invoc_id) => Scope::MacroRules(
-                        self.output_legacy_scopes
+                Scope::DeriveHelpersCompat => Scope::MacroRules(parent_scope.macro_rules),
+                Scope::MacroRules(macro_rules_scope) => match macro_rules_scope {
+                    MacroRulesScope::Binding(binding) => {
+                        Scope::MacroRules(binding.parent_macro_rules_scope)
+                    }
+                    MacroRulesScope::Invocation(invoc_id) => Scope::MacroRules(
+                        self.output_macro_rules_scopes
                             .get(&invoc_id)
                             .cloned()
-                            .unwrap_or(self.invocation_parent_scopes[&invoc_id].legacy),
+                            .unwrap_or(self.invocation_parent_scopes[&invoc_id].macro_rules),
                     ),
-                    LegacyScope::Empty => Scope::Module(module),
+                    MacroRulesScope::Empty => Scope::Module(module),
                 },
                 Scope::CrateRoot => match ns {
                     TypeNS => {
@@ -1610,18 +1622,18 @@ impl<'a> Resolver<'a> {
         if ident.name == kw::Invalid {
             return Some(LexicalScopeBinding::Res(Res::Err));
         }
-        let (general_span, modern_span) = if ident.name == kw::SelfUpper {
+        let (general_span, normalized_span) = if ident.name == kw::SelfUpper {
             // FIXME(jseyfried) improve `Self` hygiene
             let empty_span = ident.span.with_ctxt(SyntaxContext::root());
             (empty_span, empty_span)
         } else if ns == TypeNS {
-            let modern_span = ident.span.modern();
-            (modern_span, modern_span)
+            let normalized_span = ident.span.normalize_to_macros_2_0();
+            (normalized_span, normalized_span)
         } else {
-            (ident.span.modern_and_legacy(), ident.span.modern())
+            (ident.span.normalize_to_macro_rules(), ident.span.normalize_to_macros_2_0())
         };
         ident.span = general_span;
-        let modern_ident = Ident { span: modern_span, ..ident };
+        let normalized_ident = Ident { span: normalized_span, ..ident };
 
         // Walk backwards up the ribs in scope.
         let record_used = record_used_id.is_some();
@@ -1629,8 +1641,8 @@ impl<'a> Resolver<'a> {
         for i in (0..ribs.len()).rev() {
             debug!("walk rib\n{:?}", ribs[i].bindings);
             // Use the rib kind to determine whether we are resolving parameters
-            // (modern hygiene) or local variables (legacy hygiene).
-            let rib_ident = if ribs[i].kind.contains_params() { modern_ident } else { ident };
+            // (macro 2.0 hygiene) or local variables (`macro_rules` hygiene).
+            let rib_ident = if ribs[i].kind.contains_params() { normalized_ident } else { ident };
             if let Some(res) = ribs[i].bindings.get(&rib_ident).cloned() {
                 // The ident resolves to a type parameter or local variable.
                 return Some(LexicalScopeBinding::Res(self.validate_res_from_ribs(
@@ -1673,7 +1685,7 @@ impl<'a> Resolver<'a> {
             }
         }
 
-        ident = modern_ident;
+        ident = normalized_ident;
         let mut poisoned = None;
         loop {
             let opt_module = if let Some(node_id) = record_used_id {
@@ -1842,14 +1854,14 @@ impl<'a> Resolver<'a> {
         let mut adjusted_parent_scope = parent_scope;
         match module {
             ModuleOrUniformRoot::Module(m) => {
-                if let Some(def) = ident.span.modernize_and_adjust(m.expansion) {
+                if let Some(def) = ident.span.normalize_to_macros_2_0_and_adjust(m.expansion) {
                     tmp_parent_scope =
                         ParentScope { module: self.macro_def_scope(def), ..*parent_scope };
                     adjusted_parent_scope = &tmp_parent_scope;
                 }
             }
             ModuleOrUniformRoot::ExternPrelude => {
-                ident.span.modernize_and_adjust(ExpnId::root());
+                ident.span.normalize_to_macros_2_0_and_adjust(ExpnId::root());
             }
             ModuleOrUniformRoot::CrateRootAndExternPrelude | ModuleOrUniformRoot::CurrentScope => {
                 // No adjustments
@@ -1872,14 +1884,14 @@ impl<'a> Resolver<'a> {
         let mark = if ident.name == kw::DollarCrate {
             // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
             // we don't want to pretend that the `macro_rules!` definition is in the `macro`
-            // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
+            // as described in `SyntaxContext::apply_mark`, so we ignore prepended opaque marks.
             // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
             // definitions actually produced by `macro` and `macro` definitions produced by
             // `macro_rules!`, but at least such configurations are not stable yet.
-            ctxt = ctxt.modern_and_legacy();
+            ctxt = ctxt.normalize_to_macro_rules();
             let mut iter = ctxt.marks().into_iter().rev().peekable();
             let mut result = None;
-            // Find the last modern mark from the end if it exists.
+            // Find the last opaque mark from the end if it exists.
             while let Some(&(mark, transparency)) = iter.peek() {
                 if transparency == Transparency::Opaque {
                     result = Some(mark);
@@ -1888,7 +1900,7 @@ impl<'a> Resolver<'a> {
                     break;
                 }
             }
-            // Then find the last legacy mark from the end if it exists.
+            // Then find the last semi-transparent mark from the end if it exists.
             for (mark, transparency) in iter {
                 if transparency == Transparency::SemiTransparent {
                     result = Some(mark);
@@ -1898,7 +1910,7 @@ impl<'a> Resolver<'a> {
             }
             result
         } else {
-            ctxt = ctxt.modern();
+            ctxt = ctxt.normalize_to_macros_2_0();
             ctxt.adjust(ExpnId::root())
         };
         let module = match mark {
@@ -1910,7 +1922,7 @@ impl<'a> Resolver<'a> {
 
     fn resolve_self(&mut self, ctxt: &mut SyntaxContext, module: Module<'a>) -> Module<'a> {
         let mut module = self.get_module(module.normal_ancestor_id);
-        while module.span.ctxt().modern() != *ctxt {
+        while module.span.ctxt().normalize_to_macros_2_0() != *ctxt {
             let parent = module.parent.unwrap_or_else(|| self.macro_def_scope(ctxt.remove_mark()));
             module = self.get_module(parent.normal_ancestor_id);
         }
@@ -1978,7 +1990,7 @@ impl<'a> Resolver<'a> {
 
             if ns == TypeNS {
                 if allow_super && name == kw::Super {
-                    let mut ctxt = ident.span.ctxt().modern();
+                    let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
                     let self_module = match i {
                         0 => Some(self.resolve_self(&mut ctxt, parent_scope.module)),
                         _ => match module {
@@ -2004,7 +2016,7 @@ impl<'a> Resolver<'a> {
                 }
                 if i == 0 {
                     if name == kw::SelfLower {
-                        let mut ctxt = ident.span.ctxt().modern();
+                        let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
                         module = Some(ModuleOrUniformRoot::Module(
                             self.resolve_self(&mut ctxt, parent_scope.module),
                         ));
@@ -2413,21 +2425,21 @@ impl<'a> Resolver<'a> {
         }
     }
 
-    fn disambiguate_legacy_vs_modern(
+    fn disambiguate_macro_rules_vs_modularized(
         &self,
-        legacy: &'a NameBinding<'a>,
-        modern: &'a NameBinding<'a>,
+        macro_rules: &'a NameBinding<'a>,
+        modularized: &'a NameBinding<'a>,
     ) -> bool {
-        // Some non-controversial subset of ambiguities "modern macro name" vs "macro_rules"
+        // Some non-controversial subset of ambiguities "modularized macro name" vs "macro_rules"
         // is disambiguated to mitigate regressions from macro modularization.
         // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
         match (
-            self.binding_parent_modules.get(&PtrKey(legacy)),
-            self.binding_parent_modules.get(&PtrKey(modern)),
+            self.binding_parent_modules.get(&PtrKey(macro_rules)),
+            self.binding_parent_modules.get(&PtrKey(modularized)),
         ) {
-            (Some(legacy), Some(modern)) => {
-                legacy.normal_ancestor_id == modern.normal_ancestor_id
-                    && modern.is_ancestor_of(legacy)
+            (Some(macro_rules), Some(modularized)) => {
+                macro_rules.normal_ancestor_id == modularized.normal_ancestor_id
+                    && modularized.is_ancestor_of(macro_rules)
             }
             _ => false,
         }
@@ -2757,7 +2769,7 @@ impl<'a> Resolver<'a> {
             // Make sure `self`, `super` etc produce an error when passed to here.
             return None;
         }
-        self.extern_prelude.get(&ident.modern()).cloned().and_then(|entry| {
+        self.extern_prelude.get(&ident.normalize_to_macros_2_0()).cloned().and_then(|entry| {
             if let Some(binding) = entry.extern_crate_item {
                 if !speculative && entry.introduced_by_item {
                     self.record_use(ident, TypeNS, binding, false);
diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs
index e11aec90669..058ead95f50 100644
--- a/src/librustc_resolve/macros.rs
+++ b/src/librustc_resolve/macros.rs
@@ -33,26 +33,26 @@ use std::{mem, ptr};
 type Res = def::Res<NodeId>;
 
 /// Binding produced by a `macro_rules` item.
-/// Not modularized, can shadow previous legacy bindings, etc.
+/// Not modularized, can shadow previous `macro_rules` bindings, etc.
 #[derive(Debug)]
-pub struct LegacyBinding<'a> {
+pub struct MacroRulesBinding<'a> {
     crate binding: &'a NameBinding<'a>,
-    /// Legacy scope into which the `macro_rules` item was planted.
-    crate parent_legacy_scope: LegacyScope<'a>,
+    /// `macro_rules` scope into which the `macro_rules` item was planted.
+    crate parent_macro_rules_scope: MacroRulesScope<'a>,
     crate ident: Ident,
 }
 
 /// The scope introduced by a `macro_rules!` macro.
 /// This starts at the macro's definition and ends at the end of the macro's parent
 /// module (named or unnamed), or even further if it escapes with `#[macro_use]`.
-/// Some macro invocations need to introduce legacy scopes too because they
+/// Some macro invocations need to introduce `macro_rules` scopes too because they
 /// can potentially expand into macro definitions.
 #[derive(Copy, Clone, Debug)]
-pub enum LegacyScope<'a> {
+pub enum MacroRulesScope<'a> {
     /// Empty "root" scope at the crate start containing no names.
     Empty,
     /// The scope introduced by a `macro_rules!` macro definition.
-    Binding(&'a LegacyBinding<'a>),
+    Binding(&'a MacroRulesBinding<'a>),
     /// The scope introduced by a macro invocation that can potentially
     /// create a `macro_rules!` macro definition.
     Invocation(ExpnId),
@@ -159,8 +159,8 @@ impl<'a> base::Resolver for Resolver<'a> {
         // Integrate the new AST fragment into all the definition and module structures.
         // We are inside the `expansion` now, but other parent scope components are still the same.
         let parent_scope = ParentScope { expansion, ..self.invocation_parent_scopes[&expansion] };
-        let output_legacy_scope = self.build_reduced_graph(fragment, parent_scope);
-        self.output_legacy_scopes.insert(expansion, output_legacy_scope);
+        let output_macro_rules_scope = self.build_reduced_graph(fragment, parent_scope);
+        self.output_macro_rules_scopes.insert(expansion, output_macro_rules_scope);
 
         parent_scope.module.unexpanded_invocations.borrow_mut().remove(&expansion);
     }
@@ -258,7 +258,13 @@ impl<'a> base::Resolver for Resolver<'a> {
                             force,
                         ) {
                             Ok((Some(ext), _)) => {
-                                let span = path.segments.last().unwrap().ident.span.modern();
+                                let span = path
+                                    .segments
+                                    .last()
+                                    .unwrap()
+                                    .ident
+                                    .span
+                                    .normalize_to_macros_2_0();
                                 helper_attrs.extend(
                                     ext.helper_attrs.iter().map(|name| Ident::new(*name, span)),
                                 );
@@ -608,12 +614,14 @@ impl<'a> Resolver<'a> {
                         }
                         result
                     }
-                    Scope::MacroRules(legacy_scope) => match legacy_scope {
-                        LegacyScope::Binding(legacy_binding) if ident == legacy_binding.ident => {
-                            Ok((legacy_binding.binding, Flags::MACRO_RULES))
+                    Scope::MacroRules(macro_rules_scope) => match macro_rules_scope {
+                        MacroRulesScope::Binding(macro_rules_binding)
+                            if ident == macro_rules_binding.ident =>
+                        {
+                            Ok((macro_rules_binding.binding, Flags::MACRO_RULES))
                         }
-                        LegacyScope::Invocation(invoc_id)
-                            if !this.output_legacy_scopes.contains_key(&invoc_id) =>
+                        MacroRulesScope::Invocation(invoc_id)
+                            if !this.output_macro_rules_scopes.contains_key(&invoc_id) =>
                         {
                             Err(Determinacy::Undetermined)
                         }
@@ -759,16 +767,18 @@ impl<'a> Resolver<'a> {
                                     Some(AmbiguityKind::DeriveHelper)
                                 } else if innermost_flags.contains(Flags::MACRO_RULES)
                                     && flags.contains(Flags::MODULE)
-                                    && !this
-                                        .disambiguate_legacy_vs_modern(innermost_binding, binding)
+                                    && !this.disambiguate_macro_rules_vs_modularized(
+                                        innermost_binding,
+                                        binding,
+                                    )
                                     || flags.contains(Flags::MACRO_RULES)
                                         && innermost_flags.contains(Flags::MODULE)
-                                        && !this.disambiguate_legacy_vs_modern(
+                                        && !this.disambiguate_macro_rules_vs_modularized(
                                             binding,
                                             innermost_binding,
                                         )
                                 {
-                                    Some(AmbiguityKind::LegacyVsModern)
+                                    Some(AmbiguityKind::MacroRulesVsModularized)
                                 } else if innermost_binding.is_glob_import() {
                                     Some(AmbiguityKind::GlobVsOuter)
                                 } else if innermost_binding
diff --git a/src/librustc_span/hygiene.rs b/src/librustc_span/hygiene.rs
index a368a881674..e073d735a12 100644
--- a/src/librustc_span/hygiene.rs
+++ b/src/librustc_span/hygiene.rs
@@ -201,11 +201,11 @@ impl HygieneData {
         true
     }
 
-    fn modern(&self, ctxt: SyntaxContext) -> SyntaxContext {
+    fn normalize_to_macros_2_0(&self, ctxt: SyntaxContext) -> SyntaxContext {
         self.syntax_context_data[ctxt.0 as usize].opaque
     }
 
-    fn modern_and_legacy(&self, ctxt: SyntaxContext) -> SyntaxContext {
+    fn normalize_to_macro_rules(&self, ctxt: SyntaxContext) -> SyntaxContext {
         self.syntax_context_data[ctxt.0 as usize].opaque_and_semitransparent
     }
 
@@ -266,9 +266,9 @@ impl HygieneData {
 
         let call_site_ctxt = self.expn_data(expn_id).call_site.ctxt();
         let mut call_site_ctxt = if transparency == Transparency::SemiTransparent {
-            self.modern(call_site_ctxt)
+            self.normalize_to_macros_2_0(call_site_ctxt)
         } else {
-            self.modern_and_legacy(call_site_ctxt)
+            self.normalize_to_macro_rules(call_site_ctxt)
         };
 
         if call_site_ctxt == SyntaxContext::root() {
@@ -491,10 +491,10 @@ impl SyntaxContext {
         HygieneData::with(|data| data.adjust(self, expn_id))
     }
 
-    /// Like `SyntaxContext::adjust`, but also modernizes `self`.
-    pub fn modernize_and_adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> {
+    /// Like `SyntaxContext::adjust`, but also normalizes `self` to macros 2.0.
+    pub fn normalize_to_macros_2_0_and_adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> {
         HygieneData::with(|data| {
-            *self = data.modern(*self);
+            *self = data.normalize_to_macros_2_0(*self);
             data.adjust(self, expn_id)
         })
     }
@@ -527,7 +527,7 @@ impl SyntaxContext {
     pub fn glob_adjust(&mut self, expn_id: ExpnId, glob_span: Span) -> Option<Option<ExpnId>> {
         HygieneData::with(|data| {
             let mut scope = None;
-            let mut glob_ctxt = data.modern(glob_span.ctxt());
+            let mut glob_ctxt = data.normalize_to_macros_2_0(glob_span.ctxt());
             while !data.is_descendant_of(expn_id, data.outer_expn(glob_ctxt)) {
                 scope = Some(data.remove_mark(&mut glob_ctxt).0);
                 if data.remove_mark(self).0 != scope.unwrap() {
@@ -558,7 +558,7 @@ impl SyntaxContext {
                 return None;
             }
 
-            let mut glob_ctxt = data.modern(glob_span.ctxt());
+            let mut glob_ctxt = data.normalize_to_macros_2_0(glob_span.ctxt());
             let mut marks = Vec::new();
             while !data.is_descendant_of(expn_id, data.outer_expn(glob_ctxt)) {
                 marks.push(data.remove_mark(&mut glob_ctxt));
@@ -574,20 +574,20 @@ impl SyntaxContext {
 
     pub fn hygienic_eq(self, other: SyntaxContext, expn_id: ExpnId) -> bool {
         HygieneData::with(|data| {
-            let mut self_modern = data.modern(self);
-            data.adjust(&mut self_modern, expn_id);
-            self_modern == data.modern(other)
+            let mut self_normalized = data.normalize_to_macros_2_0(self);
+            data.adjust(&mut self_normalized, expn_id);
+            self_normalized == data.normalize_to_macros_2_0(other)
         })
     }
 
     #[inline]
-    pub fn modern(self) -> SyntaxContext {
-        HygieneData::with(|data| data.modern(self))
+    pub fn normalize_to_macros_2_0(self) -> SyntaxContext {
+        HygieneData::with(|data| data.normalize_to_macros_2_0(self))
     }
 
     #[inline]
-    pub fn modern_and_legacy(self) -> SyntaxContext {
-        HygieneData::with(|data| data.modern_and_legacy(self))
+    pub fn normalize_to_macro_rules(self) -> SyntaxContext {
+        HygieneData::with(|data| data.normalize_to_macro_rules(self))
     }
 
     #[inline]
diff --git a/src/librustc_span/lib.rs b/src/librustc_span/lib.rs
index b5224e57cd2..caa50e9a41c 100644
--- a/src/librustc_span/lib.rs
+++ b/src/librustc_span/lib.rs
@@ -548,9 +548,9 @@ impl Span {
     }
 
     #[inline]
-    pub fn modernize_and_adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> {
+    pub fn normalize_to_macros_2_0_and_adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> {
         let mut span = self.data();
-        let mark = span.ctxt.modernize_and_adjust(expn_id);
+        let mark = span.ctxt.normalize_to_macros_2_0_and_adjust(expn_id);
         *self = Span::new(span.lo, span.hi, span.ctxt);
         mark
     }
@@ -576,15 +576,15 @@ impl Span {
     }
 
     #[inline]
-    pub fn modern(self) -> Span {
+    pub fn normalize_to_macros_2_0(self) -> Span {
         let span = self.data();
-        span.with_ctxt(span.ctxt.modern())
+        span.with_ctxt(span.ctxt.normalize_to_macros_2_0())
     }
 
     #[inline]
-    pub fn modern_and_legacy(self) -> Span {
+    pub fn normalize_to_macro_rules(self) -> Span {
         let span = self.data();
-        span.with_ctxt(span.ctxt.modern_and_legacy())
+        span.with_ctxt(span.ctxt.normalize_to_macro_rules())
     }
 }
 
diff --git a/src/librustc_span/symbol.rs b/src/librustc_span/symbol.rs
index bca4bfee85a..5760e1d004e 100644
--- a/src/librustc_span/symbol.rs
+++ b/src/librustc_span/symbol.rs
@@ -853,12 +853,12 @@ impl Ident {
     }
 
     /// "Normalize" ident for use in comparisons using "item hygiene".
-    /// Identifiers with same string value become same if they came from the same "modern" macro
+    /// Identifiers with same string value become same if they came from the same macro 2.0 macro
     /// (e.g., `macro` item, but not `macro_rules` item) and stay different if they came from
-    /// different "modern" macros.
+    /// different macro 2.0 macros.
     /// Technically, this operation strips all non-opaque marks from ident's syntactic context.
-    pub fn modern(self) -> Ident {
-        Ident::new(self.name, self.span.modern())
+    pub fn normalize_to_macros_2_0(self) -> Ident {
+        Ident::new(self.name, self.span.normalize_to_macros_2_0())
     }
 
     /// "Normalize" ident for use in comparisons using "local variable hygiene".
@@ -866,8 +866,8 @@ impl Ident {
     /// macro (e.g., `macro` or `macro_rules!` items) and stay different if they came from different
     /// non-transparent macros.
     /// Technically, this operation strips all transparent marks from ident's syntactic context.
-    pub fn modern_and_legacy(self) -> Ident {
-        Ident::new(self.name, self.span.modern_and_legacy())
+    pub fn normalize_to_macro_rules(self) -> Ident {
+        Ident::new(self.name, self.span.normalize_to_macro_rules())
     }
 
     /// Convert the name to a `SymbolStr`. This is a slowish operation because
diff --git a/src/librustc_trait_selection/traits/error_reporting/mod.rs b/src/librustc_trait_selection/traits/error_reporting/mod.rs
index abd9638bfa7..46654a4e8b4 100644
--- a/src/librustc_trait_selection/traits/error_reporting/mod.rs
+++ b/src/librustc_trait_selection/traits/error_reporting/mod.rs
@@ -715,7 +715,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
             Node::Item(&hir::Item { span, kind: hir::ItemKind::Fn(ref sig, ..), .. })
             | Node::ImplItem(&hir::ImplItem {
                 span,
-                kind: hir::ImplItemKind::Method(ref sig, _),
+                kind: hir::ImplItemKind::Fn(ref sig, _),
                 ..
             })
             | Node::TraitItem(&hir::TraitItem {
diff --git a/src/librustc_trait_selection/traits/error_reporting/on_unimplemented.rs b/src/librustc_trait_selection/traits/error_reporting/on_unimplemented.rs
index 6e3074cd3ca..3d0dd73f03c 100644
--- a/src/librustc_trait_selection/traits/error_reporting/on_unimplemented.rs
+++ b/src/librustc_trait_selection/traits/error_reporting/on_unimplemented.rs
@@ -90,11 +90,11 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                 })
             }
             hir::Node::TraitItem(hir::TraitItem {
-                kind: hir::TraitItemKind::Fn(_, hir::TraitMethod::Provided(body_id)),
+                kind: hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(body_id)),
                 ..
             }) => self.describe_generator(*body_id).or_else(|| Some("a trait method")),
             hir::Node::ImplItem(hir::ImplItem {
-                kind: hir::ImplItemKind::Method(sig, body_id),
+                kind: hir::ImplItemKind::Fn(sig, body_id),
                 ..
             }) => self.describe_generator(*body_id).or_else(|| {
                 Some(if let hir::FnHeader { asyncness: hir::IsAsync::Async, .. } = sig.header {
diff --git a/src/librustc_trait_selection/traits/error_reporting/suggestions.rs b/src/librustc_trait_selection/traits/error_reporting/suggestions.rs
index 656c3c7e613..6fe6d7aab28 100644
--- a/src/librustc_trait_selection/traits/error_reporting/suggestions.rs
+++ b/src/librustc_trait_selection/traits/error_reporting/suggestions.rs
@@ -203,7 +203,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                 })
                 | hir::Node::ImplItem(hir::ImplItem {
                     generics,
-                    kind: hir::ImplItemKind::Method(..),
+                    kind: hir::ImplItemKind::Fn(..),
                     ..
                 })
                 | hir::Node::Item(hir::Item {
diff --git a/src/librustc_traits/lowering/environment.rs b/src/librustc_traits/lowering/environment.rs
index db392ede432..69d0bd09296 100644
--- a/src/librustc_traits/lowering/environment.rs
+++ b/src/librustc_traits/lowering/environment.rs
@@ -190,7 +190,7 @@ crate fn environment(tcx: TyCtxt<'_>, def_id: DefId) -> Environment<'_> {
         },
 
         Node::ImplItem(item) => match item.kind {
-            ImplItemKind::Method(..) => NodeKind::Fn,
+            ImplItemKind::Fn(..) => NodeKind::Fn,
             _ => NodeKind::Other,
         },
 
diff --git a/src/librustc_typeck/astconv.rs b/src/librustc_typeck/astconv.rs
index be8090cf21b..b273efa7827 100644
--- a/src/librustc_typeck/astconv.rs
+++ b/src/librustc_typeck/astconv.rs
@@ -1441,12 +1441,14 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         let (assoc_ident, def_scope) =
             tcx.adjust_ident_and_get_scope(binding.item_name, candidate.def_id(), hir_ref_id);
 
-        // We have already adjusted the item name above, so compare with `ident.modern()` instead
+        // We have already adjusted the item name above, so compare with `ident.normalize_to_macros_2_0()` instead
         // of calling `filter_by_name_and_kind`.
         let assoc_ty = tcx
             .associated_items(candidate.def_id())
             .filter_by_name_unhygienic(assoc_ident.name)
-            .find(|i| i.kind == ty::AssocKind::Type && i.ident.modern() == assoc_ident)
+            .find(|i| {
+                i.kind == ty::AssocKind::Type && i.ident.normalize_to_macros_2_0() == assoc_ident
+            })
             .expect("missing associated type");
 
         if !assoc_ty.vis.is_accessible_from(def_scope, tcx) {
@@ -2298,12 +2300,15 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         let (assoc_ident, def_scope) =
             tcx.adjust_ident_and_get_scope(assoc_ident, trait_did, hir_ref_id);
 
-        // We have already adjusted the item name above, so compare with `ident.modern()` instead
+        // We have already adjusted the item name above, so compare with `ident.normalize_to_macros_2_0()` instead
         // of calling `filter_by_name_and_kind`.
         let item = tcx
             .associated_items(trait_did)
             .in_definition_order()
-            .find(|i| i.kind.namespace() == Namespace::TypeNS && i.ident.modern() == assoc_ident)
+            .find(|i| {
+                i.kind.namespace() == Namespace::TypeNS
+                    && i.ident.normalize_to_macros_2_0() == assoc_ident
+            })
             .expect("missing associated type");
 
         let ty = self.projected_ty_from_poly_trait_ref(span, item.def_id, assoc_segment, bound);
diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs
index 1dde57124ee..779b87f6623 100644
--- a/src/librustc_typeck/check/compare_method.rs
+++ b/src/librustc_typeck/check/compare_method.rs
@@ -403,7 +403,7 @@ fn extract_spans_for_error_reporting<'a, 'tcx>(
     let tcx = infcx.tcx;
     let impl_m_hir_id = tcx.hir().as_local_hir_id(impl_m.def_id).unwrap();
     let (impl_m_output, impl_m_iter) = match tcx.hir().expect_impl_item(impl_m_hir_id).kind {
-        ImplItemKind::Method(ref impl_m_sig, _) => {
+        ImplItemKind::Fn(ref impl_m_sig, _) => {
             (&impl_m_sig.decl.output, impl_m_sig.decl.inputs.iter())
         }
         _ => bug!("{:?} is not a method", impl_m),
@@ -732,7 +732,7 @@ fn compare_number_of_method_arguments<'tcx>(
         };
         let impl_m_hir_id = tcx.hir().as_local_hir_id(impl_m.def_id).unwrap();
         let impl_span = match tcx.hir().expect_impl_item(impl_m_hir_id).kind {
-            ImplItemKind::Method(ref impl_m_sig, _) => {
+            ImplItemKind::Fn(ref impl_m_sig, _) => {
                 let pos = if impl_number_args > 0 { impl_number_args - 1 } else { 0 };
                 if let Some(arg) = impl_m_sig.decl.inputs.get(pos) {
                     if pos == 0 {
@@ -873,7 +873,7 @@ fn compare_synthetic_generics<'tcx>(
                         let impl_m = tcx.hir().as_local_hir_id(impl_m.def_id)?;
                         let impl_m = tcx.hir().impl_item(hir::ImplItemId { hir_id: impl_m });
                         let input_tys = match impl_m.kind {
-                            hir::ImplItemKind::Method(ref sig, _) => sig.decl.inputs,
+                            hir::ImplItemKind::Fn(ref sig, _) => sig.decl.inputs,
                             _ => unreachable!(),
                         };
                         struct Visitor(Option<Span>, hir::def_id::DefId);
diff --git a/src/librustc_typeck/check/expr.rs b/src/librustc_typeck/check/expr.rs
index 93f9050b26e..4531d93c01d 100644
--- a/src/librustc_typeck/check/expr.rs
+++ b/src/librustc_typeck/check/expr.rs
@@ -1203,7 +1203,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .fields
             .iter()
             .enumerate()
-            .map(|(i, field)| (field.ident.modern(), (i, field)))
+            .map(|(i, field)| (field.ident.normalize_to_macros_2_0(), (i, field)))
             .collect::<FxHashMap<_, _>>();
 
         let mut seen_fields = FxHashMap::default();
@@ -1469,7 +1469,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     let (ident, def_scope) =
                         self.tcx.adjust_ident_and_get_scope(field, base_def.did, self.body_id);
                     let fields = &base_def.non_enum_variant().fields;
-                    if let Some(index) = fields.iter().position(|f| f.ident.modern() == ident) {
+                    if let Some(index) =
+                        fields.iter().position(|f| f.ident.normalize_to_macros_2_0() == ident)
+                    {
                         let field = &fields[index];
                         let field_ty = self.field_ty(expr.span, field, substs);
                         // Save the index of all fields regardless of their visibility in case
diff --git a/src/librustc_typeck/check/method/suggest.rs b/src/librustc_typeck/check/method/suggest.rs
index ef779cfa834..3eb3624a296 100644
--- a/src/librustc_typeck/check/method/suggest.rs
+++ b/src/librustc_typeck/check/method/suggest.rs
@@ -939,10 +939,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 })) = id.map(|id| self.tcx.hir().get(id))
                                 {
                                     let self_first_arg = match method {
-                                        hir::TraitMethod::Required([ident, ..]) => {
+                                        hir::TraitFn::Required([ident, ..]) => {
                                             ident.name == kw::SelfLower
                                         }
-                                        hir::TraitMethod::Provided(body_id) => {
+                                        hir::TraitFn::Provided(body_id) => {
                                             match &self.tcx.hir().body(*body_id).params[..] {
                                                 [hir::Param {
                                                     pat:
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index d0d421746ae..55e395afad9 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -816,14 +816,14 @@ fn primary_body_of(
         },
         Node::TraitItem(item) => match item.kind {
             hir::TraitItemKind::Const(ref ty, Some(body)) => Some((body, Some(ty), None, None)),
-            hir::TraitItemKind::Fn(ref sig, hir::TraitMethod::Provided(body)) => {
+            hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
                 Some((body, None, Some(&sig.header), Some(&sig.decl)))
             }
             _ => None,
         },
         Node::ImplItem(item) => match item.kind {
             hir::ImplItemKind::Const(ref ty, body) => Some((body, Some(ty), None, None)),
-            hir::ImplItemKind::Method(ref sig, body) => {
+            hir::ImplItemKind::Fn(ref sig, body) => {
                 Some((body, None, Some(&sig.header), Some(&sig.decl)))
             }
             _ => None,
@@ -1896,7 +1896,7 @@ fn check_specialization_validity<'tcx>(
 ) {
     let kind = match impl_item.kind {
         hir::ImplItemKind::Const(..) => ty::AssocKind::Const,
-        hir::ImplItemKind::Method(..) => ty::AssocKind::Method,
+        hir::ImplItemKind::Fn(..) => ty::AssocKind::Method,
         hir::ImplItemKind::OpaqueTy(..) => ty::AssocKind::OpaqueTy,
         hir::ImplItemKind::TyAlias(_) => ty::AssocKind::Type,
     };
@@ -2019,7 +2019,7 @@ fn check_impl_items_against_trait<'tcx>(
                         err.emit()
                     }
                 }
-                hir::ImplItemKind::Method(..) => {
+                hir::ImplItemKind::Fn(..) => {
                     let opt_trait_span = tcx.hir().span_if_local(ty_trait_item.def_id);
                     if ty_trait_item.kind == ty::AssocKind::Method {
                         compare_impl_method(
@@ -4738,9 +4738,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let node = self.tcx.hir().get(self.tcx.hir().get_parent_item(id));
         match node {
             Node::Item(&hir::Item { kind: hir::ItemKind::Fn(_, _, body_id), .. })
-            | Node::ImplItem(&hir::ImplItem {
-                kind: hir::ImplItemKind::Method(_, body_id), ..
-            }) => {
+            | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Fn(_, body_id), .. }) => {
                 let body = self.tcx.hir().body(body_id);
                 if let ExprKind::Block(block, _) = &body.value.kind {
                     return Some(block.span);
@@ -4779,7 +4777,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }) => Some((&sig.decl, ident, true)),
             Node::ImplItem(&hir::ImplItem {
                 ident,
-                kind: hir::ImplItemKind::Method(ref sig, ..),
+                kind: hir::ImplItemKind::Fn(ref sig, ..),
                 ..
             }) => Some((&sig.decl, ident, false)),
             _ => None,
@@ -4864,11 +4862,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             match hir.get_if_local(def_id) {
                 Some(Node::Item(hir::Item { kind: ItemKind::Fn(.., body_id), .. }))
                 | Some(Node::ImplItem(hir::ImplItem {
-                    kind: hir::ImplItemKind::Method(_, body_id),
+                    kind: hir::ImplItemKind::Fn(_, body_id),
                     ..
                 }))
                 | Some(Node::TraitItem(hir::TraitItem {
-                    kind: hir::TraitItemKind::Fn(.., hir::TraitMethod::Provided(body_id)),
+                    kind: hir::TraitItemKind::Fn(.., hir::TraitFn::Provided(body_id)),
                     ..
                 })) => {
                     let body = hir.body(*body_id);
@@ -4939,7 +4937,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         .join(", ")
                 }
                 Some(Node::TraitItem(hir::TraitItem {
-                    kind: hir::TraitItemKind::Fn(.., hir::TraitMethod::Required(idents)),
+                    kind: hir::TraitItemKind::Fn(.., hir::TraitFn::Required(idents)),
                     ..
                 })) => {
                     sugg_call = idents
diff --git a/src/librustc_typeck/check/pat.rs b/src/librustc_typeck/check/pat.rs
index fabf3dd1153..0f3884de84e 100644
--- a/src/librustc_typeck/check/pat.rs
+++ b/src/librustc_typeck/check/pat.rs
@@ -1023,7 +1023,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .fields
             .iter()
             .enumerate()
-            .map(|(i, field)| (field.ident.modern(), (i, field)))
+            .map(|(i, field)| (field.ident.normalize_to_macros_2_0(), (i, field)))
             .collect::<FxHashMap<_, _>>();
 
         // Keep track of which fields have already appeared in the pattern.
@@ -1064,7 +1064,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let mut unmentioned_fields = variant
             .fields
             .iter()
-            .map(|field| field.ident.modern())
+            .map(|field| field.ident.normalize_to_macros_2_0())
             .filter(|ident| !used_fields.contains_key(&ident))
             .collect::<Vec<_>>();
 
diff --git a/src/librustc_typeck/check/wfcheck.rs b/src/librustc_typeck/check/wfcheck.rs
index 026e68e10e0..23826c84509 100644
--- a/src/librustc_typeck/check/wfcheck.rs
+++ b/src/librustc_typeck/check/wfcheck.rs
@@ -248,7 +248,7 @@ pub fn check_impl_item(tcx: TyCtxt<'_>, def_id: DefId) {
     let impl_item = tcx.hir().expect_impl_item(hir_id);
 
     let method_sig = match impl_item.kind {
-        hir::ImplItemKind::Method(ref sig, _) => Some(sig),
+        hir::ImplItemKind::Fn(ref sig, _) => Some(sig),
         _ => None,
     };
 
diff --git a/src/librustc_typeck/coherence/inherent_impls_overlap.rs b/src/librustc_typeck/coherence/inherent_impls_overlap.rs
index 1eae9d3b7fa..7513759c76b 100644
--- a/src/librustc_typeck/coherence/inherent_impls_overlap.rs
+++ b/src/librustc_typeck/coherence/inherent_impls_overlap.rs
@@ -26,7 +26,8 @@ impl InherentOverlapChecker<'tcx> {
             let collision = impl_items2.filter_by_name_unhygienic(item1.ident.name).any(|item2| {
                 // Symbols and namespace match, compare hygienically.
                 item1.kind.namespace() == item2.kind.namespace()
-                    && item1.ident.modern() == item2.ident.modern()
+                    && item1.ident.normalize_to_macros_2_0()
+                        == item2.ident.normalize_to_macros_2_0()
             });
 
             if collision {
@@ -50,11 +51,12 @@ impl InherentOverlapChecker<'tcx> {
             let collision = impl_items2.filter_by_name_unhygienic(item1.ident.name).find(|item2| {
                 // Symbols and namespace match, compare hygienically.
                 item1.kind.namespace() == item2.kind.namespace()
-                    && item1.ident.modern() == item2.ident.modern()
+                    && item1.ident.normalize_to_macros_2_0()
+                        == item2.ident.normalize_to_macros_2_0()
             });
 
             if let Some(item2) = collision {
-                let name = item1.ident.modern();
+                let name = item1.ident.normalize_to_macros_2_0();
                 let mut err = struct_span_err!(
                     self.tcx.sess,
                     self.tcx.span_of_impl(item1.def_id).unwrap(),
diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs
index 779b30c55e1..1ee344db1dd 100644
--- a/src/librustc_typeck/collect.rs
+++ b/src/librustc_typeck/collect.rs
@@ -745,7 +745,7 @@ fn convert_impl_item(tcx: TyCtxt<'_>, impl_item_id: hir::HirId) {
     tcx.predicates_of(def_id);
     let impl_item = tcx.hir().expect_impl_item(impl_item_id);
     match impl_item.kind {
-        hir::ImplItemKind::Method(..) => {
+        hir::ImplItemKind::Fn(..) => {
             tcx.fn_sig(def_id);
         }
         hir::ImplItemKind::TyAlias(_) | hir::ImplItemKind::OpaqueTy(_) => {
@@ -828,7 +828,7 @@ fn convert_variant(
         .iter()
         .map(|f| {
             let fid = tcx.hir().local_def_id(f.hir_id);
-            let dup_span = seen_fields.get(&f.ident.modern()).cloned();
+            let dup_span = seen_fields.get(&f.ident.normalize_to_macros_2_0()).cloned();
             if let Some(prev_span) = dup_span {
                 struct_span_err!(
                     tcx.sess,
@@ -841,7 +841,7 @@ fn convert_variant(
                 .span_label(prev_span, format!("`{}` first declared here", f.ident))
                 .emit();
             } else {
-                seen_fields.insert(f.ident.modern(), f.span);
+                seen_fields.insert(f.ident.normalize_to_macros_2_0(), f.span);
             }
 
             ty::FieldDef {
@@ -1127,7 +1127,7 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option<S
             _ => None,
         },
         Node::ImplItem(item) => match item.kind {
-            hir::ImplItemKind::Method(ref sig, _) => {
+            hir::ImplItemKind::Fn(ref sig, _) => {
                 has_late_bound_regions(tcx, &item.generics, &sig.decl)
             }
             _ => None,
@@ -1437,12 +1437,12 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
 
     match tcx.hir().get(hir_id) {
         TraitItem(hir::TraitItem {
-            kind: TraitItemKind::Fn(sig, TraitMethod::Provided(_)),
+            kind: TraitItemKind::Fn(sig, TraitFn::Provided(_)),
             ident,
             generics,
             ..
         })
-        | ImplItem(hir::ImplItem { kind: ImplItemKind::Method(sig, _), ident, generics, .. })
+        | ImplItem(hir::ImplItem { kind: ImplItemKind::Fn(sig, _), ident, generics, .. })
         | Item(hir::Item { kind: ItemKind::Fn(sig, generics, _), ident, .. }) => {
             match get_infer_ret_ty(&sig.decl.output) {
                 Some(ty) => {
diff --git a/src/librustc_typeck/collect/type_of.rs b/src/librustc_typeck/collect/type_of.rs
index c4a8edd86f8..c5d3d276721 100644
--- a/src/librustc_typeck/collect/type_of.rs
+++ b/src/librustc_typeck/collect/type_of.rs
@@ -47,7 +47,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
         },
 
         Node::ImplItem(item) => match item.kind {
-            ImplItemKind::Method(..) => {
+            ImplItemKind::Fn(..) => {
                 let substs = InternalSubsts::identity_for_item(tcx, def_id);
                 tcx.mk_fn_def(def_id, substs)
             }
diff --git a/src/librustc_typeck/impl_wf_check.rs b/src/librustc_typeck/impl_wf_check.rs
index 0a765a1f9c9..5fb510d6e33 100644
--- a/src/librustc_typeck/impl_wf_check.rs
+++ b/src/librustc_typeck/impl_wf_check.rs
@@ -227,7 +227,7 @@ fn enforce_impl_items_are_distinct(tcx: TyCtxt<'_>, impl_item_refs: &[hir::ImplI
             hir::ImplItemKind::TyAlias(_) => &mut seen_type_items,
             _ => &mut seen_value_items,
         };
-        match seen_items.entry(impl_item.ident.modern()) {
+        match seen_items.entry(impl_item.ident.normalize_to_macros_2_0()) {
             Occupied(entry) => {
                 let mut err = struct_span_err!(
                     tcx.sess,
diff --git a/src/librustc_typeck/variance/constraints.rs b/src/librustc_typeck/variance/constraints.rs
index fc3b7201a1e..54f84272ae8 100644
--- a/src/librustc_typeck/variance/constraints.rs
+++ b/src/librustc_typeck/variance/constraints.rs
@@ -111,7 +111,7 @@ impl<'a, 'tcx, 'v> ItemLikeVisitor<'v> for ConstraintContext<'a, 'tcx> {
     }
 
     fn visit_impl_item(&mut self, impl_item: &hir::ImplItem<'_>) {
-        if let hir::ImplItemKind::Method(..) = impl_item.kind {
+        if let hir::ImplItemKind::Fn(..) = impl_item.kind {
             self.visit_node_helper(impl_item.hir_id);
         }
     }
diff --git a/src/librustc_typeck/variance/mod.rs b/src/librustc_typeck/variance/mod.rs
index b1fcc3d3fe8..3cbb42bb5f3 100644
--- a/src/librustc_typeck/variance/mod.rs
+++ b/src/librustc_typeck/variance/mod.rs
@@ -60,7 +60,7 @@ fn variances_of(tcx: TyCtxt<'_>, item_def_id: DefId) -> &[ty::Variance] {
         },
 
         Node::ImplItem(item) => match item.kind {
-            hir::ImplItemKind::Method(..) => {}
+            hir::ImplItemKind::Fn(..) => {}
 
             _ => unsupported(),
         },
diff --git a/src/librustc_typeck/variance/terms.rs b/src/librustc_typeck/variance/terms.rs
index bd44a3eda98..7e6ec96b379 100644
--- a/src/librustc_typeck/variance/terms.rs
+++ b/src/librustc_typeck/variance/terms.rs
@@ -170,7 +170,7 @@ impl<'a, 'tcx, 'v> ItemLikeVisitor<'v> for TermsContext<'a, 'tcx> {
     }
 
     fn visit_impl_item(&mut self, impl_item: &hir::ImplItem<'_>) {
-        if let hir::ImplItemKind::Method(..) = impl_item.kind {
+        if let hir::ImplItemKind::Fn(..) = impl_item.kind {
             self.add_inferreds_for_item(impl_item.hir_id);
         }
     }
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index e2fca8f39a3..c4ad4554a00 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1084,10 +1084,10 @@ impl Clean<Item> for hir::TraitItem<'_> {
             hir::TraitItemKind::Const(ref ty, default) => {
                 AssocConstItem(ty.clean(cx), default.map(|e| print_const_expr(cx, e)))
             }
-            hir::TraitItemKind::Fn(ref sig, hir::TraitMethod::Provided(body)) => {
+            hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
                 MethodItem((sig, &self.generics, body, None).clean(cx))
             }
-            hir::TraitItemKind::Fn(ref sig, hir::TraitMethod::Required(ref names)) => {
+            hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(ref names)) => {
                 let (generics, decl) = enter_impl_trait(cx, || {
                     (self.generics.clean(cx), (&*sig.decl, &names[..]).clean(cx))
                 });
@@ -1118,7 +1118,7 @@ impl Clean<Item> for hir::ImplItem<'_> {
             hir::ImplItemKind::Const(ref ty, expr) => {
                 AssocConstItem(ty.clean(cx), Some(print_const_expr(cx, expr)))
             }
-            hir::ImplItemKind::Method(ref sig, body) => {
+            hir::ImplItemKind::Fn(ref sig, body) => {
                 MethodItem((sig, &self.generics, body, Some(self.defaultness)).clean(cx))
             }
             hir::ImplItemKind::TyAlias(ref ty) => {
diff --git a/src/libstd/backtrace.rs b/src/libstd/backtrace.rs
index 97db0ff3791..34317c7a2ee 100644
--- a/src/libstd/backtrace.rs
+++ b/src/libstd/backtrace.rs
@@ -92,6 +92,7 @@
 // a backtrace or actually symbolizing it.
 
 use crate::env;
+use crate::ffi::c_void;
 use crate::fmt;
 use crate::sync::atomic::{AtomicUsize, Ordering::SeqCst};
 use crate::sync::Mutex;
@@ -144,10 +145,16 @@ fn _assert_send_sync() {
 }
 
 struct BacktraceFrame {
-    frame: backtrace::Frame,
+    frame: RawFrame,
     symbols: Vec<BacktraceSymbol>,
 }
 
+enum RawFrame {
+    Actual(backtrace::Frame),
+    #[cfg(test)]
+    Fake,
+}
+
 struct BacktraceSymbol {
     name: Option<Vec<u8>>,
     filename: Option<BytesOrWide>,
@@ -162,8 +169,8 @@ enum BytesOrWide {
 impl fmt::Debug for Backtrace {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut capture = match &self.inner {
-            Inner::Unsupported => return fmt.write_str("unsupported backtrace"),
-            Inner::Disabled => return fmt.write_str("disabled backtrace"),
+            Inner::Unsupported => return fmt.write_str("<unsupported>"),
+            Inner::Disabled => return fmt.write_str("<disabled>"),
             Inner::Captured(c) => c.lock().unwrap(),
         };
         capture.resolve();
@@ -193,11 +200,11 @@ impl fmt::Debug for BacktraceSymbol {
         if let Some(fn_name) = self.name.as_ref().map(|b| backtrace::SymbolName::new(b)) {
             write!(fmt, "fn: \"{:#}\"", fn_name)?;
         } else {
-            write!(fmt, "fn: \"<unknown>\"")?;
+            write!(fmt, "fn: <unknown>")?;
         }
 
         if let Some(fname) = self.filename.as_ref() {
-            write!(fmt, ", file: {:?}", fname)?;
+            write!(fmt, ", file: \"{:?}\"", fname)?;
         }
 
         if let Some(line) = self.lineno.as_ref() {
@@ -293,7 +300,10 @@ impl Backtrace {
         let mut actual_start = None;
         unsafe {
             backtrace::trace_unsynchronized(|frame| {
-                frames.push(BacktraceFrame { frame: frame.clone(), symbols: Vec::new() });
+                frames.push(BacktraceFrame {
+                    frame: RawFrame::Actual(frame.clone()),
+                    symbols: Vec::new(),
+                });
                 if frame.symbol_address() as usize == ip && actual_start.is_none() {
                     actual_start = Some(frames.len());
                 }
@@ -393,8 +403,13 @@ impl Capture {
         let _lock = lock();
         for frame in self.frames.iter_mut() {
             let symbols = &mut frame.symbols;
+            let frame = match &frame.frame {
+                RawFrame::Actual(frame) => frame,
+                #[cfg(test)]
+                RawFrame::Fake => unimplemented!(),
+            };
             unsafe {
-                backtrace::resolve_frame_unsynchronized(&frame.frame, |symbol| {
+                backtrace::resolve_frame_unsynchronized(frame, |symbol| {
                     symbols.push(BacktraceSymbol {
                         name: symbol.name().map(|m| m.as_bytes().to_vec()),
                         filename: symbol.filename_raw().map(|b| match b {
@@ -408,3 +423,65 @@ impl Capture {
         }
     }
 }
+
+impl RawFrame {
+    fn ip(&self) -> *mut c_void {
+        match self {
+            RawFrame::Actual(frame) => frame.ip(),
+            #[cfg(test)]
+            RawFrame::Fake => 1 as *mut c_void,
+        }
+    }
+}
+
+#[test]
+fn test_debug() {
+    let backtrace = Backtrace {
+        inner: Inner::Captured(Mutex::new(Capture {
+            actual_start: 1,
+            resolved: true,
+            frames: vec![
+                BacktraceFrame {
+                    frame: RawFrame::Fake,
+                    symbols: vec![BacktraceSymbol {
+                        name: Some(b"std::backtrace::Backtrace::create".to_vec()),
+                        filename: Some(BytesOrWide::Bytes(b"rust/backtrace.rs".to_vec())),
+                        lineno: Some(100),
+                    }],
+                },
+                BacktraceFrame {
+                    frame: RawFrame::Fake,
+                    symbols: vec![BacktraceSymbol {
+                        name: Some(b"__rust_maybe_catch_panic".to_vec()),
+                        filename: None,
+                        lineno: None,
+                    }],
+                },
+                BacktraceFrame {
+                    frame: RawFrame::Fake,
+                    symbols: vec![
+                        BacktraceSymbol {
+                            name: Some(b"std::rt::lang_start_internal".to_vec()),
+                            filename: Some(BytesOrWide::Bytes(b"rust/rt.rs".to_vec())),
+                            lineno: Some(300),
+                        },
+                        BacktraceSymbol {
+                            name: Some(b"std::rt::lang_start".to_vec()),
+                            filename: Some(BytesOrWide::Bytes(b"rust/rt.rs".to_vec())),
+                            lineno: Some(400),
+                        },
+                    ],
+                },
+            ],
+        })),
+    };
+
+    #[rustfmt::skip]
+    let expected = "Backtrace [\
+    \n    { fn: \"__rust_maybe_catch_panic\" },\
+    \n    { fn: \"std::rt::lang_start_internal\", file: \"rust/rt.rs\", line: 300 },\
+    \n    { fn: \"std::rt::lang_start\", file: \"rust/rt.rs\", line: 400 },\
+    \n]";
+
+    assert_eq!(format!("{:#?}", backtrace), expected);
+}
diff --git a/src/test/ui/error-codes/E0583.stderr b/src/test/ui/error-codes/E0583.stderr
index ef7a48bc8a4..5d47b633e78 100644
--- a/src/test/ui/error-codes/E0583.stderr
+++ b/src/test/ui/error-codes/E0583.stderr
@@ -4,7 +4,7 @@ error[E0583]: file not found for module `module_that_doesnt_exist`
 LL | mod module_that_doesnt_exist;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = help: name the file either module_that_doesnt_exist.rs or module_that_doesnt_exist/mod.rs inside the directory "$DIR"
+   = help: to create the module `module_that_doesnt_exist`, create file "$DIR/module_that_doesnt_exist.rs"
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/generator/too-many-parameters.stderr b/src/test/ui/generator/too-many-parameters.stderr
index a297ee43de9..22d40db3f26 100644
--- a/src/test/ui/generator/too-many-parameters.stderr
+++ b/src/test/ui/generator/too-many-parameters.stderr
@@ -6,3 +6,4 @@ LL |     |(), ()| {
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0628`.
diff --git a/src/test/ui/invalid-module-declaration/invalid-module-declaration.stderr b/src/test/ui/invalid-module-declaration/invalid-module-declaration.stderr
index c95df5b4534..5d2cdaef1a7 100644
--- a/src/test/ui/invalid-module-declaration/invalid-module-declaration.stderr
+++ b/src/test/ui/invalid-module-declaration/invalid-module-declaration.stderr
@@ -4,7 +4,7 @@ error[E0583]: file not found for module `baz`
 LL | pub mod baz;
    |         ^^^
    |
-   = help: name the file either bar/baz.rs or bar/baz/mod.rs inside the directory "$DIR/auxiliary/foo"
+   = help: to create the module `baz`, create file "$DIR/auxiliary/foo/bar/baz.rs"
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/missing_non_modrs_mod/missing_non_modrs_mod.stderr b/src/test/ui/missing_non_modrs_mod/missing_non_modrs_mod.stderr
index 98b74e5f5cb..e8d997e6de0 100644
--- a/src/test/ui/missing_non_modrs_mod/missing_non_modrs_mod.stderr
+++ b/src/test/ui/missing_non_modrs_mod/missing_non_modrs_mod.stderr
@@ -4,7 +4,7 @@ error[E0583]: file not found for module `missing`
 LL | mod missing;
    |     ^^^^^^^
    |
-   = help: name the file either foo/missing.rs or foo/missing/mod.rs inside the directory "$DIR"
+   = help: to create the module `missing`, create file "$DIR/foo/missing.rs"
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/missing_non_modrs_mod/missing_non_modrs_mod_inline.stderr b/src/test/ui/missing_non_modrs_mod/missing_non_modrs_mod_inline.stderr
index 457e8fcccbf..b2b0f8b466a 100644
--- a/src/test/ui/missing_non_modrs_mod/missing_non_modrs_mod_inline.stderr
+++ b/src/test/ui/missing_non_modrs_mod/missing_non_modrs_mod_inline.stderr
@@ -4,7 +4,7 @@ error[E0583]: file not found for module `missing`
 LL |     mod missing;
    |         ^^^^^^^
    |
-   = help: name the file either missing.rs or missing/mod.rs inside the directory "$DIR/foo_inline/inline"
+   = help: to create the module `missing`, create file "$DIR/foo_inline/inline/missing.rs"
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/mod_file_not_exist.rs b/src/test/ui/parser/mod_file_not_exist.rs
index e662c707a38..71fbc7aea45 100644
--- a/src/test/ui/parser/mod_file_not_exist.rs
+++ b/src/test/ui/parser/mod_file_not_exist.rs
@@ -1,7 +1,7 @@
 // ignore-windows
 
 mod not_a_real_file; //~ ERROR file not found for module `not_a_real_file`
-//~^ HELP name the file either not_a_real_file.rs or not_a_real_file/mod.rs inside the directory
+//~^ HELP to create the module `not_a_real_file`, create file "
 
 fn main() {
     assert_eq!(mod_file_aux::bar(), 10);
diff --git a/src/test/ui/parser/mod_file_not_exist.stderr b/src/test/ui/parser/mod_file_not_exist.stderr
index dadf4b29dcf..db3ea04ac76 100644
--- a/src/test/ui/parser/mod_file_not_exist.stderr
+++ b/src/test/ui/parser/mod_file_not_exist.stderr
@@ -4,7 +4,7 @@ error[E0583]: file not found for module `not_a_real_file`
 LL | mod not_a_real_file;
    |     ^^^^^^^^^^^^^^^
    |
-   = help: name the file either not_a_real_file.rs or not_a_real_file/mod.rs inside the directory "$DIR"
+   = help: to create the module `not_a_real_file`, create file "$DIR/not_a_real_file.rs"
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/mod_file_not_exist_windows.rs b/src/test/ui/parser/mod_file_not_exist_windows.rs
index 0cd9e9c799f..97cadab675f 100644
--- a/src/test/ui/parser/mod_file_not_exist_windows.rs
+++ b/src/test/ui/parser/mod_file_not_exist_windows.rs
@@ -1,7 +1,7 @@
 // only-windows
 
 mod not_a_real_file; //~ ERROR file not found for module `not_a_real_file`
-//~^ HELP name the file either not_a_real_file.rs or not_a_real_file\mod.rs inside the directory
+//~^ HELP to create the module `not_a_real_file`, create file
 
 fn main() {
     assert_eq!(mod_file_aux::bar(), 10);
diff --git a/src/test/ui/parser/mod_file_not_exist_windows.stderr b/src/test/ui/parser/mod_file_not_exist_windows.stderr
index 60ae00abab1..a58db80f73d 100644
--- a/src/test/ui/parser/mod_file_not_exist_windows.stderr
+++ b/src/test/ui/parser/mod_file_not_exist_windows.stderr
@@ -4,7 +4,7 @@ error[E0583]: file not found for module `not_a_real_file`
 LL | mod not_a_real_file;
    |     ^^^^^^^^^^^^^^^
    |
-   = help: name the file either not_a_real_file.rs or not_a_real_file/mod.rs inside the directory "$DIR"
+   = help: to create the module `not_a_real_file`, create file "$DIR/not_a_real_file.rs"
 
 error: aborting due to previous error