Convert some InternedStrings to Symbols.

This avoids the needs for various conversions, and makes the code
slightly faster, because `Symbol` comparisons and hashing is faster.

Author: nnethercote

src/librustc/hir/mod.rs

@@ -19,7 +19,7 @@ use crate::ty::query::Providers;
 use crate::util::nodemap::{NodeMap, FxHashSet};
 
 use errors::FatalError;
-use syntax_pos::{Span, DUMMY_SP, symbol::InternedString, MultiSpan};
+use syntax_pos::{Span, DUMMY_SP, MultiSpan};
 use syntax::source_map::Spanned;
 use syntax::ast::{self, CrateSugar, Ident, Name, NodeId, AsmDialect};
 use syntax::ast::{Attribute, Label, LitKind, StrStyle, FloatTy, IntTy, UintTy};
@@ -628,9 +628,9 @@ impl Generics {
         own_counts
     }
 
-    pub fn get_named(&self, name: InternedString) -> Option<&GenericParam> {
+    pub fn get_named(&self, name: Symbol) -> Option<&GenericParam> {
         for param in &self.params {
-            if name == param.name.ident().as_interned_str() {
+            if name == param.name.ident().name {
                 return Some(param);
             }
         }

src/librustc/infer/mod.rs

@@ -32,7 +32,7 @@ use std::cell::{Cell, Ref, RefCell, RefMut};
 use std::collections::BTreeMap;
 use std::fmt;
 use syntax::ast;
-use syntax_pos::symbol::InternedString;
+use syntax_pos::symbol::Symbol;
 use syntax_pos::Span;
 
 use self::combine::CombineFields;
@@ -392,7 +392,7 @@ pub enum RegionVariableOrigin {
     Coercion(Span),
 
     /// Region variables created as the values for early-bound regions
-    EarlyBoundRegion(Span, InternedString),
+    EarlyBoundRegion(Span, Symbol),
 
     /// Region variables created for bound regions
     /// in a function or method that is called

src/librustc/infer/type_variable.rs

@@ -1,4 +1,4 @@
-use syntax::symbol::InternedString;
+use syntax::symbol::Symbol;
 use syntax_pos::Span;
 use crate::ty::{self, Ty, TyVid};
 
@@ -49,7 +49,7 @@ pub enum TypeVariableOriginKind {
     MiscVariable,
     NormalizeProjectionType,
     TypeInference,
-    TypeParameterDefinition(InternedString),
+    TypeParameterDefinition(Symbol),
 
     /// One of the upvars or closure kind parameters in a `ClosureSubsts`
     /// (before it has been determined).

src/librustc/infer/unify_key.rs

@@ -3,7 +3,7 @@ use crate::mir::interpret::ConstValue;
 use rustc_data_structures::unify::{NoError, EqUnifyValue, UnifyKey, UnifyValue, UnificationTable};
 use rustc_data_structures::unify::InPlace;
 use syntax_pos::{Span, DUMMY_SP};
-use syntax::symbol::InternedString;
+use syntax::symbol::Symbol;
 
 use std::cmp;
 use std::marker::PhantomData;
@@ -90,7 +90,7 @@ pub struct ConstVariableOrigin {
 pub enum ConstVariableOriginKind {
     MiscVariable,
     ConstInference,
-    ConstParameterDefinition(InternedString),
+    ConstParameterDefinition(Symbol),
     SubstitutionPlaceholder,
 }
 

src/librustc/traits/error_reporting.rs

@@ -406,7 +406,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 },
                 GenericParamDefKind::Lifetime => continue,
             };
-            let name = param.name.as_symbol();
+            let name = param.name;
             flags.push((name, Some(value)));
         }
 

src/librustc/traits/object_safety.rs

@@ -19,7 +19,7 @@ use crate::ty::subst::{Subst, InternalSubsts};
 use std::borrow::Cow;
 use std::iter::{self};
 use syntax::ast::{self};
-use syntax::symbol::InternedString;
+use syntax::symbol::Symbol;
 use syntax_pos::{Span, DUMMY_SP};
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
@@ -560,7 +560,7 @@ impl<'tcx> TyCtxt<'tcx> {
         // are implemented
         let unsized_self_ty: Ty<'tcx> = self.mk_ty_param(
             ::std::u32::MAX,
-            InternedString::intern("RustaceansAreAwesome"),
+            Symbol::intern("RustaceansAreAwesome"),
         );
 
         // `Receiver[Self => U]`

src/librustc/traits/on_unimplemented.rs

@@ -250,7 +250,7 @@ impl<'tcx> OnUnimplementedFormatString {
                     Position::ArgumentNamed(s) if s == sym::from_desugaring => (),
                     // So is `{A}` if A is a type parameter
                     Position::ArgumentNamed(s) => match generics.params.iter().find(|param| {
-                        param.name.as_symbol() == s
+                        param.name == s
                     }) {
                         Some(_) => (),
                         None => {
@@ -289,7 +289,7 @@ impl<'tcx> OnUnimplementedFormatString {
                 },
                 GenericParamDefKind::Lifetime => return None
             };
-            let name = param.name.as_symbol();
+            let name = param.name;
             Some((name, value))
         }).collect::<FxHashMap<Symbol, String>>();
         let empty_string = String::new();

src/librustc/traits/structural_impls.rs

@@ -4,7 +4,7 @@ use crate::traits;
 use crate::traits::project::Normalized;
 use crate::ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
 use crate::ty::{self, Lift, Ty, TyCtxt};
-use syntax::symbol::InternedString;
+use syntax::symbol::Symbol;
 
 use std::fmt;
 use std::rc::Rc;
@@ -261,11 +261,11 @@ impl fmt::Display for traits::QuantifierKind {
 /// for debug output in tests anyway.
 struct BoundNamesCollector {
     // Just sort by name because `BoundRegion::BrNamed` does not have a `BoundVar` index anyway.
-    regions: BTreeSet<InternedString>,
+    regions: BTreeSet<Symbol>,
 
     // Sort by `BoundVar` index, so usually this should be equivalent to the order given
     // by the list of type parameters.
-    types: BTreeMap<u32, InternedString>,
+    types: BTreeMap<u32, Symbol>,
 
     binder_index: ty::DebruijnIndex,
 }
@@ -319,7 +319,7 @@ impl<'tcx> TypeVisitor<'tcx> for BoundNamesCollector {
                     match bound_ty.kind {
                         ty::BoundTyKind::Param(name) => name,
                         ty::BoundTyKind::Anon =>
-                            InternedString::intern(&format!("^{}", bound_ty.var.as_u32()),
+                            Symbol::intern(&format!("^{}", bound_ty.var.as_u32()),
                         ),
                     }
                 );
@@ -340,7 +340,7 @@ impl<'tcx> TypeVisitor<'tcx> for BoundNamesCollector {
                     }
 
                     ty::BoundRegion::BrAnon(var) => {
-                        self.regions.insert(InternedString::intern(&format!("'^{}", var)));
+                        self.regions.insert(Symbol::intern(&format!("'^{}", var)));
                     }
 
                     _ => (),

src/librustc/ty/context.rs

@@ -72,7 +72,7 @@ use syntax::ast;
 use syntax::attr;
 use syntax::source_map::MultiSpan;
 use syntax::feature_gate;
-use syntax::symbol::{Symbol, InternedString, kw, sym};
+use syntax::symbol::{Symbol, kw, sym};
 use syntax_pos::Span;
 
 pub struct AllArenas {
@@ -949,7 +949,7 @@ impl<'tcx> CommonTypes<'tcx> {
             f64: mk(Float(ast::FloatTy::F64)),
             self_param: mk(ty::Param(ty::ParamTy {
                 index: 0,
-                name: kw::SelfUpper.as_interned_str(),
+                name: kw::SelfUpper,
             })),
 
             trait_object_dummy_self: mk(Infer(ty::FreshTy(0))),
@@ -2552,15 +2552,15 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     #[inline]
-    pub fn mk_ty_param(self, index: u32, name: InternedString) -> Ty<'tcx> {
+    pub fn mk_ty_param(self, index: u32, name: Symbol) -> Ty<'tcx> {
         self.mk_ty(Param(ParamTy { index, name: name }))
     }
 
     #[inline]
     pub fn mk_const_param(
         self,
         index: u32,
-        name: InternedString,
+        name: Symbol,
         ty: Ty<'tcx>
     ) -> &'tcx Const<'tcx> {
         self.mk_const(ty::Const {

src/librustc/ty/mod.rs

@@ -849,7 +849,7 @@ impl ty::EarlyBoundRegion {
     /// Does this early bound region have a name? Early bound regions normally
     /// always have names except when using anonymous lifetimes (`'_`).
     pub fn has_name(&self) -> bool {
-        self.name != kw::UnderscoreLifetime.as_interned_str()
+        self.name != kw::UnderscoreLifetime
     }
 }
 
@@ -866,7 +866,7 @@ pub enum GenericParamDefKind {
 
 #[derive(Clone, RustcEncodable, RustcDecodable, HashStable)]
 pub struct GenericParamDef {
-    pub name: InternedString,
+    pub name: Symbol,
     pub def_id: DefId,
     pub index: u32,