Eliminate unnecessary Ident::with_empty_ctxts

src/librustc/hir/lowering.rs

@@ -1614,7 +1614,7 @@ impl<'a> LoweringContext<'a> {
         trace!("registering existential type with id {:#?}", exist_ty_id);
         let exist_ty_item = hir::Item {
             hir_id: exist_ty_id,
-            ident: Ident::with_empty_ctxt(kw::Invalid),
+            ident: Ident::invalid(),
             attrs: Default::default(),
             node: exist_ty_item_kind,
             vis: respan(span.shrink_to_lo(), hir::VisibilityKind::Inherited),

src/librustc/hir/map/def_collector.rs

@@ -138,7 +138,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
         // information we encapsulate into, the better
         let def_data = match i.node {
             ItemKind::Impl(..) => DefPathData::Impl,
-            ItemKind::Mod(..) if i.ident == Ident::with_empty_ctxt(kw::Invalid) => {
+            ItemKind::Mod(..) if i.ident.name == kw::Invalid => {
                 return visit::walk_item(self, i);
             }
             ItemKind::Mod(..) | ItemKind::Trait(..) | ItemKind::TraitAlias(..) |

src/librustc/hir/mod.rs

@@ -234,8 +234,7 @@ pub enum LifetimeName {
 impl LifetimeName {
     pub fn ident(&self) -> Ident {
         match *self {
-            LifetimeName::Implicit => Ident::with_empty_ctxt(kw::Invalid),
+            LifetimeName::Implicit | LifetimeName::Error => Ident::invalid(),
-            LifetimeName::Error => Ident::with_empty_ctxt(kw::Invalid),
             LifetimeName::Underscore => Ident::with_empty_ctxt(kw::UnderscoreLifetime),
             LifetimeName::Static => Ident::with_empty_ctxt(kw::StaticLifetime),
             LifetimeName::Param(param_name) => param_name.ident(),

src/librustc/middle/resolve_lifetime.rs

@@ -1602,7 +1602,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                     } {
                         debug!("id = {:?} span = {:?} name = {:?}", id, span, name);
 
-                        if name == ast::Ident::with_empty_ctxt(kw::UnderscoreLifetime) {
+                        if name.name == kw::UnderscoreLifetime {
                             continue;
                         }
 

src/librustc_resolve/build_reduced_graph.rs

@@ -420,7 +420,7 @@ impl<'a> Resolver<'a> {
 
             ItemKind::GlobalAsm(..) => {}
 
-            ItemKind::Mod(..) if ident == Ident::with_empty_ctxt(kw::Invalid) => {} // Crate root
+            ItemKind::Mod(..) if ident.name == kw::Invalid => {} // Crate root
 
             ItemKind::Mod(..) => {
                 let def_id = self.definitions.local_def_id(item.id);

src/librustc_resolve/diagnostics.rs

@@ -460,7 +460,7 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
             (Some(fst), _) if fst.ident.span.rust_2018() &&
                               !fst.ident.is_path_segment_keyword() => {
                 // Insert a placeholder that's later replaced by `self`/`super`/etc.
-                path.insert(0, Segment::from_ident(Ident::with_empty_ctxt(kw::Invalid)));
+                path.insert(0, Segment::from_ident(Ident::invalid()));
             }
             _ => return None,
         }

src/librustc_resolve/lib.rs

@@ -4669,7 +4669,7 @@ impl<'a> Resolver<'a> {
     {
         let mut candidates = Vec::new();
         let mut seen_modules = FxHashSet::default();
-        let not_local_module = crate_name != Ident::with_empty_ctxt(kw::Crate);
+        let not_local_module = crate_name.name != kw::Crate;
         let mut worklist = vec![(start_module, Vec::<ast::PathSegment>::new(), not_local_module)];
 
         while let Some((in_module,

src/librustc_resolve/resolve_imports.rs

@@ -992,7 +992,7 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
                     // HACK(eddyb) `lint_if_path_starts_with_module` needs at least
                     // 2 segments, so the `resolve_path` above won't trigger it.
                     let mut full_path = directive.module_path.clone();
-                    full_path.push(Segment::from_ident(Ident::with_empty_ctxt(kw::Invalid)));
+                    full_path.push(Segment::from_ident(Ident::invalid()));
                     self.lint_if_path_starts_with_module(
                         directive.crate_lint(),
                         &full_path,

src/libsyntax/ext/build.rs

@@ -1175,7 +1175,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
                 vis: ast::Visibility, vp: P<ast::UseTree>) -> P<ast::Item> {
         P(ast::Item {
             id: ast::DUMMY_NODE_ID,
-            ident: Ident::with_empty_ctxt(kw::Invalid),
+            ident: Ident::invalid(),
             attrs: vec![],
             node: ast::ItemKind::Use(vp),
             vis,

src/libsyntax/ext/expand.rs

@@ -271,7 +271,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             attrs: krate.attrs,
             span: krate.span,
             node: ast::ItemKind::Mod(krate.module),
-            ident: Ident::with_empty_ctxt(kw::Invalid),
+            ident: Ident::invalid(),
             id: ast::DUMMY_NODE_ID,
             vis: respan(krate.span.shrink_to_lo(), ast::VisibilityKind::Public),
             tokens: None,
@@ -708,7 +708,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         };
         let path = &mac.node.path;
 
-        let ident = ident.unwrap_or_else(|| Ident::with_empty_ctxt(kw::Invalid));
+        let ident = ident.unwrap_or_else(|| Ident::invalid());
         let validate_and_set_expn_info = |this: &mut Self, // arg instead of capture
                                           def_site_span: Option<Span>,
                                           allow_internal_unstable,
@@ -929,7 +929,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 invoc.expansion_data.mark.set_expn_info(expn_info);
                 let span = span.with_ctxt(self.cx.backtrace());
                 let dummy = ast::MetaItem { // FIXME(jseyfried) avoid this
-                    path: Path::from_ident(Ident::with_empty_ctxt(kw::Invalid)),
+                    path: Path::from_ident(Ident::invalid()),
                     span: DUMMY_SP,
                     node: ast::MetaItemKind::Word,
                 };
@@ -1338,7 +1338,7 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
                 })
             }
             ast::ItemKind::Mod(ast::Mod { inner, .. }) => {
-                if item.ident == Ident::with_empty_ctxt(kw::Invalid) {
+                if item.ident == Ident::invalid() {
                     return noop_flat_map_item(item, self);
                 }
 

src/libsyntax/ext/placeholders.rs

@@ -6,7 +6,6 @@ use crate::ext::hygiene::Mark;
 use crate::tokenstream::TokenStream;
 use crate::mut_visit::*;
 use crate::ptr::P;
-use crate::symbol::kw;
 use crate::ThinVec;
 
 use smallvec::{smallvec, SmallVec};
@@ -22,7 +21,7 @@ pub fn placeholder(kind: AstFragmentKind, id: ast::NodeId) -> AstFragment {
         })
     }
 
-    let ident = ast::Ident::with_empty_ctxt(kw::Invalid);
+    let ident = ast::Ident::invalid();
     let attrs = Vec::new();
     let generics = ast::Generics::default();
     let vis = dummy_spanned(ast::VisibilityKind::Inherited);

src/libsyntax/ext/tt/quoted.rs

@@ -228,7 +228,7 @@ pub fn parse(
                 result.push(TokenTree::MetaVarDecl(
                     span,
                     ident,
-                    ast::Ident::with_empty_ctxt(kw::Invalid),
+                    ast::Ident::invalid(),
                 ));
             }
 
@@ -334,7 +334,7 @@ where
                     pprust::token_to_string(&tok)
                 );
                 sess.span_diagnostic.span_err(span, &msg);
-                TokenTree::MetaVar(span, ast::Ident::with_empty_ctxt(kw::Invalid))
+                TokenTree::MetaVar(span, ast::Ident::invalid())
             }
 
             // There are no more tokens. Just return the `$` we already have.

src/libsyntax/mut_visit.rs

@@ -11,7 +11,6 @@ use crate::ast::*;
 use crate::source_map::{Spanned, respan};
 use crate::parse::token::{self, Token};
 use crate::ptr::P;
-use crate::symbol::kw;
 use crate::ThinVec;
 use crate::tokenstream::*;
 use crate::util::map_in_place::MapInPlace;
@@ -977,7 +976,7 @@ pub fn noop_visit_mod<T: MutVisitor>(Mod { inner, items, inline: _ }: &mut Mod,
 pub fn noop_visit_crate<T: MutVisitor>(krate: &mut Crate, vis: &mut T) {
     visit_clobber(krate, |Crate { module, attrs, span }| {
         let item = P(Item {
-            ident: Ident::with_empty_ctxt(kw::Invalid),
+            ident: Ident::invalid(),
             attrs,
             id: DUMMY_NODE_ID,
             vis: respan(span.shrink_to_lo(), VisibilityKind::Public),

src/libsyntax/parse/parser.rs

@@ -1480,9 +1480,7 @@ impl<'a> Parser<'a> {
             (ident, TraitItemKind::Const(ty, default), ast::Generics::default())
         } else if let Some(mac) = self.parse_assoc_macro_invoc("trait", None, &mut false)? {
             // trait item macro.
-            (Ident::with_empty_ctxt(kw::Invalid),
+            (Ident::invalid(), ast::TraitItemKind::Macro(mac), ast::Generics::default())
-             ast::TraitItemKind::Macro(mac),
-             ast::Generics::default())
         } else {
             let (constness, unsafety, mut asyncness, abi) = self.parse_fn_front_matter()?;
 
@@ -4988,7 +4986,7 @@ impl<'a> Parser<'a> {
 
             // it's a macro invocation
             let id = match self.token {
-                token::OpenDelim(_) => Ident::with_empty_ctxt(kw::Invalid), // no special identifier
+                token::OpenDelim(_) => Ident::invalid(), // no special identifier
                 _ => self.parse_ident()?,
             };
 
@@ -6396,7 +6394,7 @@ impl<'a> Parser<'a> {
         // code copied from parse_macro_use_or_failure... abstraction!
         if let Some(mac) = self.parse_assoc_macro_invoc("impl", Some(vis), at_end)? {
             // method macro
-            Ok((Ident::with_empty_ctxt(kw::Invalid), vec![], ast::Generics::default(),
+            Ok((Ident::invalid(), vec![], ast::Generics::default(),
                 ast::ImplItemKind::Macro(mac)))
         } else {
             let (constness, unsafety, mut asyncness, abi) = self.parse_fn_front_matter()?;
@@ -6616,7 +6614,7 @@ impl<'a> Parser<'a> {
             }
         };
 
-        Ok((Ident::with_empty_ctxt(kw::Invalid), item_kind, Some(attrs)))
+        Ok((Ident::invalid(), item_kind, Some(attrs)))
     }
 
     fn parse_late_bound_lifetime_defs(&mut self) -> PResult<'a, Vec<GenericParam>> {
@@ -7414,7 +7412,7 @@ impl<'a> Parser<'a> {
             abi,
             items: foreign_items
         };
-        let invalid = Ident::with_empty_ctxt(kw::Invalid);
+        let invalid = Ident::invalid();
         Ok(self.mk_item(lo.to(prev_span), invalid, ItemKind::ForeignMod(m), visibility, attrs))
     }
 
@@ -7662,7 +7660,7 @@ impl<'a> Parser<'a> {
 
             let span = lo.to(self.prev_span);
             let item =
-                self.mk_item(span, Ident::with_empty_ctxt(kw::Invalid), item_, visibility, attrs);
+                self.mk_item(span, Ident::invalid(), item_, visibility, attrs);
             return Ok(Some(item));
         }
 
@@ -8108,7 +8106,7 @@ impl<'a> Parser<'a> {
             Some(mac) => {
                 Ok(
                     ForeignItem {
-                        ident: Ident::with_empty_ctxt(kw::Invalid),
+                        ident: Ident::invalid(),
                         span: lo.to(self.prev_span),
                         id: ast::DUMMY_NODE_ID,
                         attrs,
@@ -8155,7 +8153,7 @@ impl<'a> Parser<'a> {
             let id = if self.token.is_ident() {
                 self.parse_ident()?
             } else {
-                Ident::with_empty_ctxt(kw::Invalid) // no special identifier
+                Ident::invalid() // no special identifier
             };
             // eat a matched-delimiter token tree:
             let (delim, tts) = self.expect_delimited_token_tree()?;

src/libsyntax/std_inject.rs

@@ -118,7 +118,7 @@ pub fn maybe_inject_crates_ref(
             span,
         })),
         id: ast::DUMMY_NODE_ID,
-        ident: ast::Ident::with_empty_ctxt(kw::Invalid),
+        ident: ast::Ident::invalid(),
         span,
         tokens: None,
     }));

src/libsyntax_ext/deriving/generic/mod.rs

@@ -686,7 +686,7 @@ impl<'a> TraitDef<'a> {
         };
 
         cx.item(self.span,
-                Ident::with_empty_ctxt(kw::Invalid),
+                Ident::invalid(),
                 a,
                 ast::ItemKind::Impl(unsafety,
                                     ast::ImplPolarity::Positive,

src/libsyntax_ext/global_asm.rs

@@ -37,7 +37,7 @@ pub fn expand_global_asm<'cx>(cx: &'cx mut ExtCtxt<'_>,
     match parse_global_asm(cx, sp, tts) {
         Ok(Some(global_asm)) => {
             MacEager::items(smallvec![P(ast::Item {
-                ident: ast::Ident::with_empty_ctxt(Symbol::intern("")),
+                ident: ast::Ident::invalid(),
                 attrs: Vec::new(),
                 id: ast::DUMMY_NODE_ID,
                 node: ast::ItemKind::GlobalAsm(P(global_asm)),

src/libsyntax_pos/symbol.rs

@@ -641,6 +641,11 @@ impl Ident {
         Ident::new(name, DUMMY_SP)
     }
 
+    #[inline]
+    pub fn invalid() -> Ident {
+        Ident::with_empty_ctxt(kw::Invalid)
+    }
+
     /// Maps an interned string to an identifier with an empty syntax context.
     pub fn from_interned_str(string: InternedString) -> Ident {
         Ident::with_empty_ctxt(string.as_symbol())