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

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"),

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)
             }

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),
+            })
     }
 }
 

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)
     }
 

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)]

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);
 }
 

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());

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);

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);
             }

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);

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)
 }
 

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) &&

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

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;
+    };
+}
+```