Use Symbol in ParamTy.

This removes the need for a lot of `as_str()` and `as_interned_str()`
calls.

Author: nnethercote

src/librustc/hir/mod.rs

@@ -16,7 +16,7 @@ use crate::util::nodemap::{NodeMap, FxHashSet};
 use crate::mir::mono::Linkage;
 
 use errors::FatalError;
-use syntax_pos::{Span, DUMMY_SP, symbol::InternedString};
+use syntax_pos::{Span, DUMMY_SP};
 use syntax::source_map::Spanned;
 use rustc_target::spec::abi::Abi;
 use syntax::ast::{self, CrateSugar, Ident, Name, NodeId, AsmDialect};
@@ -609,9 +609,9 @@ 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/error_reporting/mod.rs

@@ -194,20 +194,20 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 let mut sp = cm.def_span(self.hir().span_by_hir_id(node));
                 if let Some(param) = self.hir()
                     .get_generics(scope)
-                    .and_then(|generics| generics.get_named(&br.name))
+                    .and_then(|generics| generics.get_named(br.name))
                 {
                     sp = param.span;
                 }
                 (format!("the lifetime {} as defined on", br.name), sp)
             }
             ty::ReFree(ty::FreeRegion {
-                bound_region: ty::BoundRegion::BrNamed(_, ref name),
+                bound_region: ty::BoundRegion::BrNamed(_, name),
                 ..
             }) => {
                 let mut sp = cm.def_span(self.hir().span_by_hir_id(node));
                 if let Some(param) = self.hir()
                     .get_generics(scope)
-                    .and_then(|generics| generics.get_named(&name))
+                    .and_then(|generics| generics.get_named(name))
                 {
                     sp = param.span;
                 }

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;
@@ -383,7 +383,7 @@ 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};
 
@@ -43,7 +43,7 @@ pub enum TypeVariableOrigin {
     MiscVariable(Span),
     NormalizeProjectionType(Span),
     TypeInference(Span),
-    TypeParameterDefinition(Span, InternedString),
+    TypeParameterDefinition(Span, 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;
@@ -84,7 +84,7 @@ impl ToType for FloatVarValue {
 pub enum ConstVariableOrigin {
     MiscVariable(Span),
     ConstInference(Span),
-    ConstParameterDefinition(Span, InternedString),
+    ConstParameterDefinition(Span, Symbol),
     SubstitutionPlaceholder(Span),
 }
 

src/librustc/traits/object_safety.rs

@@ -539,7 +539,7 @@ impl<'a, 'tcx> TyCtxt<'a, 'tcx, 'tcx> {
         // are implemented
         let unsized_self_ty: Ty<'tcx> = self.mk_ty_param(
             ::std::u32::MAX,
-            Name::intern("RustaceansAreAwesome").as_interned_str(),
+            Name::intern("RustaceansAreAwesome"),
         );
 
         // `Receiver[Self => U]`

src/librustc/traits/on_unimplemented.rs

@@ -250,7 +250,7 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedFormatString {
                     Position::ArgumentNamed(s) if s == "from_desugaring" => (),
                     // So is `{A}` if A is a type parameter
                     Position::ArgumentNamed(s) => match generics.params.iter().find(|param|
-                        param.name == s
+                        param.name.as_str() == s
                     ) {
                         Some(_) => (),
                         None => {

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,
 }
@@ -312,8 +312,6 @@ impl<'tcx> TypeVisitor<'tcx> for BoundNamesCollector {
     }
 
     fn visit_ty(&mut self, t: Ty<'tcx>) -> bool {
-        use syntax::symbol::Symbol;
-
         match t.sty {
             ty::Bound(debruijn, bound_ty) if debruijn == self.binder_index => {
                 self.types.insert(
@@ -322,7 +320,7 @@ impl<'tcx> TypeVisitor<'tcx> for BoundNamesCollector {
                         ty::BoundTyKind::Param(name) => name,
                         ty::BoundTyKind::Anon => Symbol::intern(
                             &format!("^{}", bound_ty.var.as_u32())
-                        ).as_interned_str(),
+                        ),
                     }
                 );
             }
@@ -334,8 +332,6 @@ impl<'tcx> TypeVisitor<'tcx> for BoundNamesCollector {
     }
 
     fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
-        use syntax::symbol::Symbol;
-
         match r {
             ty::ReLateBound(index, br) if *index == self.binder_index => {
                 match br {
@@ -346,7 +342,7 @@ impl<'tcx> TypeVisitor<'tcx> for BoundNamesCollector {
                     ty::BoundRegion::BrAnon(var) => {
                         self.regions.insert(Symbol::intern(
                             &format!("'^{}", var)
-                        ).as_interned_str());
+                        ));
                     }
 
                     _ => (),

src/librustc/ty/context.rs

@@ -74,7 +74,7 @@ use syntax::ast;
 use syntax::attr;
 use syntax::source_map::MultiSpan;
 use syntax::feature_gate;
-use syntax::symbol::{Symbol, keywords, InternedString, sym};
+use syntax::symbol::{Symbol, keywords, sym};
 use syntax_pos::Span;
 
 use crate::hir;
@@ -2716,15 +2716,15 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, '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 {
@@ -2735,7 +2735,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
     #[inline]
     pub fn mk_self_type(self) -> Ty<'tcx> {
-        self.mk_ty_param(0, keywords::SelfUpper.name().as_interned_str())
+        self.mk_ty_param(0, keywords::SelfUpper.name())
     }
 
     pub fn mk_param_from_def(self, param: &ty::GenericParamDef) -> Kind<'tcx> {

src/librustc/ty/mod.rs

@@ -835,7 +835,7 @@ 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 != keywords::UnderscoreLifetime.name().as_interned_str()
+        self.name != keywords::UnderscoreLifetime.name()
     }
 }
 
@@ -852,7 +852,7 @@ pub enum GenericParamDefKind {
 
 #[derive(Clone, RustcEncodable, RustcDecodable, HashStable)]
 pub struct GenericParamDef {
-    pub name: InternedString,
+    pub name: Symbol,
     pub def_id: DefId,
     pub index: u32,