Rollup merge of #49894 - Zoxc:sync-internedstring, r=michaelwoerister

Rename InternedString to LocalInternedString and introduce a new thread-safe InternedString

This is an allocation-free alternative to #46972.

Author: kennytm

src/librustc/hir/lowering.rs

@@ -655,7 +655,7 @@ impl<'a> LoweringContext<'a> {
                 self.resolver.definitions().create_def_with_parent(
                     parent_id.index,
                     def_node_id,
-                    DefPathData::LifetimeDef(str_name),
+                    DefPathData::LifetimeDef(str_name.as_interned_str()),
                     DefIndexAddressSpace::High,
                     Mark::root(),
                     span,
@@ -1302,7 +1302,7 @@ impl<'a> LoweringContext<'a> {
                     self.context.resolver.definitions().create_def_with_parent(
                         self.parent,
                         def_node_id,
-                        DefPathData::LifetimeDef(name.name().as_str()),
+                        DefPathData::LifetimeDef(name.name().as_interned_str()),
                         DefIndexAddressSpace::High,
                         Mark::root(),
                         lifetime.span,

src/librustc/hir/map/def_collector.rs

@@ -107,18 +107,18 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
         // information we encapsulate into
         let def_data = match i.node {
             ItemKind::Impl(..) => DefPathData::Impl,
-            ItemKind::Trait(..) => DefPathData::Trait(i.ident.name.as_str()),
+            ItemKind::Trait(..) => DefPathData::Trait(i.ident.name.as_interned_str()),
             ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) |
             ItemKind::TraitAlias(..) |
             ItemKind::ExternCrate(..) | ItemKind::ForeignMod(..) | ItemKind::Ty(..) =>
-                DefPathData::TypeNs(i.ident.name.as_str()),
+                DefPathData::TypeNs(i.ident.name.as_interned_str()),
             ItemKind::Mod(..) if i.ident == keywords::Invalid.ident() => {
                 return visit::walk_item(self, i);
             }
-            ItemKind::Mod(..) => DefPathData::Module(i.ident.name.as_str()),
+            ItemKind::Mod(..) => DefPathData::Module(i.ident.name.as_interned_str()),
             ItemKind::Static(..) | ItemKind::Const(..) | ItemKind::Fn(..) =>
-                DefPathData::ValueNs(i.ident.name.as_str()),
-            ItemKind::MacroDef(..) => DefPathData::MacroDef(i.ident.name.as_str()),
+                DefPathData::ValueNs(i.ident.name.as_interned_str()),
+            ItemKind::MacroDef(..) => DefPathData::MacroDef(i.ident.name.as_interned_str()),
             ItemKind::Mac(..) => return self.visit_macro_invoc(i.id, false),
             ItemKind::GlobalAsm(..) => DefPathData::Misc,
             ItemKind::Use(..) => {
@@ -133,15 +133,16 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
                     for v in &enum_definition.variants {
                         let variant_def_index =
                             this.create_def(v.node.data.id(),
-                                            DefPathData::EnumVariant(v.node.ident.name.as_str()),
+                                            DefPathData::EnumVariant(v.node.ident
+                                                                      .name.as_interned_str()),
                                             REGULAR_SPACE,
                                             v.span);
                         this.with_parent(variant_def_index, |this| {
                             for (index, field) in v.node.data.fields().iter().enumerate() {
                                 let name = field.ident.map(|ident| ident.name)
                                     .unwrap_or_else(|| Symbol::intern(&index.to_string()));
                                 this.create_def(field.id,
-                                                DefPathData::Field(name.as_str()),
+                                                DefPathData::Field(name.as_interned_str()),
                                                 REGULAR_SPACE,
                                                 field.span);
                             }
@@ -165,7 +166,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
                         let name = field.ident.map(|ident| ident.name)
                             .unwrap_or_else(|| Symbol::intern(&index.to_string()));
                         this.create_def(field.id,
-                                        DefPathData::Field(name.as_str()),
+                                        DefPathData::Field(name.as_interned_str()),
                                         REGULAR_SPACE,
                                         field.span);
                     }
@@ -187,7 +188,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
         }
 
         let def = self.create_def(foreign_item.id,
-                                  DefPathData::ValueNs(foreign_item.ident.name.as_str()),
+                                  DefPathData::ValueNs(foreign_item.ident.name.as_interned_str()),
                                   REGULAR_SPACE,
                                   foreign_item.span);
 
@@ -201,15 +202,15 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
             GenericParam::Lifetime(ref lifetime_def) => {
                 self.create_def(
                     lifetime_def.lifetime.id,
-                    DefPathData::LifetimeDef(lifetime_def.lifetime.ident.name.as_str()),
+                    DefPathData::LifetimeDef(lifetime_def.lifetime.ident.name.as_interned_str()),
                     REGULAR_SPACE,
                     lifetime_def.lifetime.ident.span
                 );
             }
             GenericParam::Type(ref ty_param) => {
                 self.create_def(
                     ty_param.id,
-                    DefPathData::TypeParam(ty_param.ident.name.as_str()),
+                    DefPathData::TypeParam(ty_param.ident.name.as_interned_str()),
                     REGULAR_SPACE,
                     ty_param.ident.span
                 );
@@ -222,8 +223,10 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
     fn visit_trait_item(&mut self, ti: &'a TraitItem) {
         let def_data = match ti.node {
             TraitItemKind::Method(..) | TraitItemKind::Const(..) =>
-                DefPathData::ValueNs(ti.ident.name.as_str()),
-            TraitItemKind::Type(..) => DefPathData::AssocTypeInTrait(ti.ident.name.as_str()),
+                DefPathData::ValueNs(ti.ident.name.as_interned_str()),
+            TraitItemKind::Type(..) => {
+                DefPathData::AssocTypeInTrait(ti.ident.name.as_interned_str())
+            },
             TraitItemKind::Macro(..) => return self.visit_macro_invoc(ti.id, false),
         };
 
@@ -240,8 +243,8 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
     fn visit_impl_item(&mut self, ii: &'a ImplItem) {
         let def_data = match ii.node {
             ImplItemKind::Method(..) | ImplItemKind::Const(..) =>
-                DefPathData::ValueNs(ii.ident.name.as_str()),
-            ImplItemKind::Type(..) => DefPathData::AssocTypeInImpl(ii.ident.name.as_str()),
+                DefPathData::ValueNs(ii.ident.name.as_interned_str()),
+            ImplItemKind::Type(..) => DefPathData::AssocTypeInImpl(ii.ident.name.as_interned_str()),
             ImplItemKind::Macro(..) => return self.visit_macro_invoc(ii.id, false),
         };
 

src/librustc/hir/map/definitions.rs

@@ -701,7 +701,7 @@ impl DefPathData {
             Typeof => "{{typeof}}",
         };
 
-        Symbol::intern(s).as_str()
+        Symbol::intern(s).as_interned_str()
     }
 
     pub fn to_string(&self) -> String {
@@ -731,7 +731,7 @@ macro_rules! define_global_metadata_kind {
                     definitions.create_def_with_parent(
                         CRATE_DEF_INDEX,
                         ast::DUMMY_NODE_ID,
-                        DefPathData::GlobalMetaData(instance.name().as_str()),
+                        DefPathData::GlobalMetaData(instance.name().as_interned_str()),
                         GLOBAL_MD_ADDRESS_SPACE,
                         Mark::root(),
                         DUMMY_SP
@@ -746,7 +746,7 @@ macro_rules! define_global_metadata_kind {
                 let def_key = DefKey {
                     parent: Some(CRATE_DEF_INDEX),
                     disambiguated_data: DisambiguatedDefPathData {
-                        data: DefPathData::GlobalMetaData(self.name().as_str()),
+                        data: DefPathData::GlobalMetaData(self.name().as_interned_str()),
                         disambiguator: 0,
                     }
                 };

src/librustc/ich/impls_syntax.rs

@@ -19,7 +19,7 @@ use std::mem;
 use syntax::ast;
 use syntax::feature_gate;
 use syntax::parse::token;
-use syntax::symbol::InternedString;
+use syntax::symbol::{InternedString, LocalInternedString};
 use syntax::tokenstream;
 use syntax_pos::FileMap;
 
@@ -34,8 +34,7 @@ impl<'a> HashStable<StableHashingContext<'a>> for InternedString {
     fn hash_stable<W: StableHasherResult>(&self,
                                           hcx: &mut StableHashingContext<'a>,
                                           hasher: &mut StableHasher<W>) {
-        let s: &str = &**self;
-        s.hash_stable(hcx, hasher);
+        self.with(|s| s.hash_stable(hcx, hasher))
     }
 }
 
@@ -50,6 +49,27 @@ impl<'a> ToStableHashKey<StableHashingContext<'a>> for InternedString {
     }
 }
 
+impl<'a> HashStable<StableHashingContext<'a>> for LocalInternedString {
+    #[inline]
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut StableHashingContext<'a>,
+                                          hasher: &mut StableHasher<W>) {
+        let s: &str = &**self;
+        s.hash_stable(hcx, hasher);
+    }
+}
+
+impl<'a> ToStableHashKey<StableHashingContext<'a>> for LocalInternedString {
+    type KeyType = LocalInternedString;
+
+    #[inline]
+    fn to_stable_hash_key(&self,
+                          _: &StableHashingContext<'a>)
+                          -> LocalInternedString {
+        self.clone()
+    }
+}
+
 impl<'a> HashStable<StableHashingContext<'a>> for ast::Name {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
@@ -66,7 +86,7 @@ impl<'a> ToStableHashKey<StableHashingContext<'a>> for ast::Name {
     fn to_stable_hash_key(&self,
                           _: &StableHashingContext<'a>)
                           -> InternedString {
-        self.as_str()
+        self.as_interned_str()
     }
 }
 

src/librustc/lib.rs

@@ -58,6 +58,7 @@
 #![feature(nonzero)]
 #![feature(proc_macro_internals)]
 #![feature(quote)]
+#![feature(optin_builtin_traits)]
 #![feature(refcell_replace_swap)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(slice_patterns)]

src/librustc/traits/on_unimplemented.rs

@@ -18,10 +18,10 @@ use util::nodemap::FxHashMap;
 use syntax::ast::{MetaItem, NestedMetaItem};
 use syntax::attr;
 use syntax_pos::Span;
-use syntax_pos::symbol::InternedString;
+use syntax_pos::symbol::LocalInternedString;
 
 #[derive(Clone, Debug)]
-pub struct OnUnimplementedFormatString(InternedString);
+pub struct OnUnimplementedFormatString(LocalInternedString);
 
 #[derive(Debug)]
 pub struct OnUnimplementedDirective {
@@ -225,7 +225,7 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedDirective {
 impl<'a, 'gcx, 'tcx> OnUnimplementedFormatString {
     pub fn try_parse(tcx: TyCtxt<'a, 'gcx, 'tcx>,
                      trait_def_id: DefId,
-                     from: InternedString,
+                     from: LocalInternedString,
                      err_sp: Span)
                      -> Result<Self, ErrorReported>
     {

src/librustc/ty/context.rs

@@ -2471,7 +2471,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     }
 
     pub fn mk_self_type(self) -> Ty<'tcx> {
-        self.mk_param(0, keywords::SelfType.name().as_str())
+        self.mk_param(0, keywords::SelfType.name().as_interned_str())
     }
 
     pub fn mk_param_from_def(self, def: &ty::TypeParameterDef) -> Ty<'tcx> {

src/librustc/ty/item_path.rs

@@ -14,7 +14,7 @@ use ty::{self, Ty, TyCtxt};
 use middle::cstore::{ExternCrate, ExternCrateSource};
 use syntax::ast;
 use syntax::symbol::Symbol;
-use syntax::symbol::InternedString;
+use syntax::symbol::LocalInternedString;
 
 use std::cell::Cell;
 
@@ -131,7 +131,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     {
         let visible_parent_map = self.visible_parent_map(LOCAL_CRATE);
 
-        let (mut cur_def, mut cur_path) = (external_def_id, Vec::<InternedString>::new());
+        let (mut cur_def, mut cur_path) = (external_def_id, Vec::<LocalInternedString>::new());
         loop {
             // If `cur_def` is a direct or injected extern crate, push the path to the crate
             // followed by the path to the item within the crate and return.
@@ -168,8 +168,9 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             }
 
             let data = cur_def_key.disambiguated_data.data;
-            let symbol =
-                data.get_opt_name().unwrap_or_else(|| Symbol::intern("<unnamed>").as_str());
+            let symbol = data.get_opt_name().map(|n| n.as_str()).unwrap_or_else(|| {
+                Symbol::intern("<unnamed>").as_str()
+            });
             cur_path.push(symbol);
 
             match visible_parent_map.get(&cur_def) {
@@ -221,7 +222,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             data @ DefPathData::GlobalMetaData(..) => {
                 let parent_def_id = self.parent_def_id(def_id).unwrap();
                 self.push_item_path(buffer, parent_def_id);
-                buffer.push(&data.as_interned_str());
+                buffer.push(&data.as_interned_str().as_symbol().as_str());
             }
             DefPathData::StructCtor => { // present `X` instead of `X::{{constructor}}`
                 let parent_def_id = self.parent_def_id(def_id).unwrap();

src/librustc/ty/maps/values.rs

@@ -37,7 +37,7 @@ impl<'tcx> Value<'tcx> for Ty<'tcx> {
 
 impl<'tcx> Value<'tcx> for ty::SymbolName {
     fn from_cycle_error<'a>(_: TyCtxt<'a, 'tcx, 'tcx>) -> Self {
-        ty::SymbolName { name: Symbol::intern("<error>").as_str() }
+        ty::SymbolName { name: Symbol::intern("<error>").as_interned_str() }
     }
 }
 

src/librustc/ty/mod.rs

@@ -51,7 +51,7 @@ use std::mem;
 use syntax::ast::{self, DUMMY_NODE_ID, Name, Ident, NodeId};
 use syntax::attr;
 use syntax::ext::hygiene::Mark;
-use syntax::symbol::{Symbol, InternedString};
+use syntax::symbol::{Symbol, LocalInternedString, InternedString};
 use syntax_pos::{DUMMY_SP, Span};
 
 use rustc_data_structures::accumulate_vec::IntoIter as AccIntoIter;
@@ -2463,7 +2463,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
     pub fn item_name(self, id: DefId) -> InternedString {
         if id.index == CRATE_DEF_INDEX {
-            self.original_crate_name(id.krate).as_str()
+            self.original_crate_name(id.krate).as_interned_str()
         } else {
             let def_key = self.def_key(id);
             // The name of a StructCtor is that of its struct parent.
@@ -2820,15 +2820,13 @@ impl_stable_hash_for!(struct self::SymbolName {
 impl SymbolName {
     pub fn new(name: &str) -> SymbolName {
         SymbolName {
-            name: Symbol::intern(name).as_str()
+            name: Symbol::intern(name).as_interned_str()
         }
     }
-}
-
-impl Deref for SymbolName {
-    type Target = str;
 
-    fn deref(&self) -> &str { &self.name }
+    pub fn as_str(&self) -> LocalInternedString {
+        self.name.as_str()
+    }
 }
 
 impl fmt::Display for SymbolName {