Auto merge of rust-lang#48586 - Zoxc:atomic-rc, r=michaelwoerister

Replace Rc with Lrc for shared data

This replaces `Rc`s reachable from `TyCtxt` with `Lrc`. This has no effect unless `cfg(parallel_queries)` is set. It also contains a fix for the `Decodable` impl for `Arc`.

r? @nikomatsakis

Author: bors

src/Cargo.lock

@@ -11,3 +11,4 @@ crate-type = ["dylib"]
 syntax = { path = "../libsyntax" }
 syntax_pos = { path = "../libsyntax_pos" }
 rustc_errors = { path = "../librustc_errors" }
+rustc_data_structures = { path = "../librustc_data_structures" }

src/libproc_macro/Cargo.toml

@@ -38,19 +38,21 @@
 #![feature(rustc_private)]
 #![feature(staged_api)]
 #![feature(lang_items)]
+#![feature(optin_builtin_traits)]
 
 #[macro_use]
 extern crate syntax;
 extern crate syntax_pos;
 extern crate rustc_errors;
+extern crate rustc_data_structures;
 
 mod diagnostic;
 
 #[unstable(feature = "proc_macro", issue = "38356")]
 pub use diagnostic::{Diagnostic, Level};
 
 use std::{ascii, fmt, iter};
-use std::rc::Rc;
+use rustc_data_structures::sync::Lrc;
 use std::str::FromStr;
 
 use syntax::ast;
@@ -306,9 +308,14 @@ pub struct LineColumn {
 #[unstable(feature = "proc_macro", issue = "38356")]
 #[derive(Clone)]
 pub struct SourceFile {
-    filemap: Rc<FileMap>,
+    filemap: Lrc<FileMap>,
 }
 
+#[unstable(feature = "proc_macro", issue = "38356")]
+impl !Send for SourceFile {}
+#[unstable(feature = "proc_macro", issue = "38356")]
+impl !Sync for SourceFile {}
+
 impl SourceFile {
     /// Get the path to this source file.
     ///
@@ -356,7 +363,7 @@ impl fmt::Debug for SourceFile {
 #[unstable(feature = "proc_macro", issue = "38356")]
 impl PartialEq for SourceFile {
     fn eq(&self, other: &Self) -> bool {
-        Rc::ptr_eq(&self.filemap, &other.filemap)
+        Lrc::ptr_eq(&self.filemap, &other.filemap)
     }
 }
 

src/libproc_macro/lib.rs

@@ -13,10 +13,10 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher,
                                            StableHashingContextProvider};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
+use rustc_data_structures::sync::Lrc;
 use std::cell::{Ref, RefCell};
 use std::env;
 use std::hash::Hash;
-use std::rc::Rc;
 use ty::TyCtxt;
 use util::common::{ProfileQueriesMsg, profq_msg};
 
@@ -32,13 +32,13 @@ use super::prev::PreviousDepGraph;
 
 #[derive(Clone)]
 pub struct DepGraph {
-    data: Option<Rc<DepGraphData>>,
+    data: Option<Lrc<DepGraphData>>,
 
     // A vector mapping depnodes from the current graph to their associated
     // result value fingerprints. Do not rely on the length of this vector
     // being the same as the number of nodes in the graph. The vector can
     // contain an arbitrary number of zero-entries at the end.
-    fingerprints: Rc<RefCell<IndexVec<DepNodeIndex, Fingerprint>>>
+    fingerprints: Lrc<RefCell<IndexVec<DepNodeIndex, Fingerprint>>>
 }
 
 
@@ -102,7 +102,7 @@ impl DepGraph {
         let fingerprints = IndexVec::from_elem_n(Fingerprint::ZERO,
                                                  (prev_graph_node_count * 115) / 100);
         DepGraph {
-            data: Some(Rc::new(DepGraphData {
+            data: Some(Lrc::new(DepGraphData {
                 previous_work_products: RefCell::new(FxHashMap()),
                 work_products: RefCell::new(FxHashMap()),
                 dep_node_debug: RefCell::new(FxHashMap()),
@@ -111,14 +111,14 @@ impl DepGraph {
                 colors: RefCell::new(DepNodeColorMap::new(prev_graph_node_count)),
                 loaded_from_cache: RefCell::new(FxHashMap()),
             })),
-            fingerprints: Rc::new(RefCell::new(fingerprints)),
+            fingerprints: Lrc::new(RefCell::new(fingerprints)),
         }
     }
 
     pub fn new_disabled() -> DepGraph {
         DepGraph {
             data: None,
-            fingerprints: Rc::new(RefCell::new(IndexVec::new())),
+            fingerprints: Lrc::new(RefCell::new(IndexVec::new())),
         }
     }
 

src/librustc/dep_graph/graph.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::rc::Rc;
+use rustc_data_structures::sync::Lrc;
 use syntax::codemap::CodeMap;
 use syntax_pos::{BytePos, FileMap};
 
@@ -18,7 +18,7 @@ struct CacheEntry {
     line_number: usize,
     line_start: BytePos,
     line_end: BytePos,
-    file: Rc<FileMap>,
+    file: Lrc<FileMap>,
     file_index: usize,
 }
 
@@ -51,7 +51,7 @@ impl<'cm> CachingCodemapView<'cm> {
 
     pub fn byte_pos_to_line_and_col(&mut self,
                                     pos: BytePos)
-                                    -> Option<(Rc<FileMap>, usize, BytePos)> {
+                                    -> Option<(Lrc<FileMap>, usize, BytePos)> {
         self.time_stamp += 1;
 
         // Check if the position is in one of the cached lines

src/librustc/ich/caching_codemap_view.rs

@@ -31,7 +31,7 @@
 pub use self::Level::*;
 pub use self::LintSource::*;
 
-use std::rc::Rc;
+use rustc_data_structures::sync::Lrc;
 
 use errors::{DiagnosticBuilder, DiagnosticId};
 use hir::def_id::{CrateNum, LOCAL_CRATE};
@@ -505,7 +505,7 @@ pub fn struct_lint_level<'a>(sess: &'a Session,
 }
 
 fn lint_levels<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, cnum: CrateNum)
-    -> Rc<LintLevelMap>
+    -> Lrc<LintLevelMap>
 {
     assert_eq!(cnum, LOCAL_CRATE);
     let mut builder = LintLevelMapBuilder {
@@ -518,7 +518,7 @@ fn lint_levels<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, cnum: CrateNum)
         intravisit::walk_crate(builder, krate);
     });
 
-    Rc::new(builder.levels.build_map())
+    Lrc::new(builder.levels.build_map())
 }
 
 struct LintLevelMapBuilder<'a, 'tcx: 'a> {

src/librustc/lint/mod.rs

@@ -37,13 +37,13 @@ use util::nodemap::NodeSet;
 use std::any::Any;
 use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};
-use std::rc::Rc;
 use rustc_data_structures::owning_ref::ErasedBoxRef;
 use syntax::ast;
 use syntax::ext::base::SyntaxExtension;
 use syntax::symbol::Symbol;
 use syntax_pos::Span;
 use rustc_back::target::Target;
+use rustc_data_structures::sync::Lrc;
 
 pub use self::NativeLibraryKind::*;
 
@@ -139,7 +139,7 @@ pub struct NativeLibrary {
 
 pub enum LoadedMacro {
     MacroDef(ast::Item),
-    ProcMacro(Rc<SyntaxExtension>),
+    ProcMacro(Lrc<SyntaxExtension>),
 }
 
 #[derive(Copy, Clone, Debug)]
@@ -206,7 +206,7 @@ pub struct ExternConstBody<'tcx> {
 
 #[derive(Clone)]
 pub struct ExternBodyNestedBodies {
-    pub nested_bodies: Rc<BTreeMap<hir::BodyId, hir::Body>>,
+    pub nested_bodies: Lrc<BTreeMap<hir::BodyId, hir::Body>>,
 
     // It would require a lot of infrastructure to enable stable-hashing Bodies
     // from other crates, so we hash on export and just store the fingerprint
@@ -225,7 +225,7 @@ pub struct ExternBodyNestedBodies {
 /// (it'd break incremental compilation) and should only be called pre-HIR (e.g.
 /// during resolve)
 pub trait CrateStore {
-    fn crate_data_as_rc_any(&self, krate: CrateNum) -> Rc<Any>;
+    fn crate_data_as_rc_any(&self, krate: CrateNum) -> Lrc<Any>;
 
     // access to the metadata loader
     fn metadata_loader(&self) -> &MetadataLoader;
@@ -234,7 +234,7 @@ pub trait CrateStore {
     fn def_key(&self, def: DefId) -> DefKey;
     fn def_path(&self, def: DefId) -> hir_map::DefPath;
     fn def_path_hash(&self, def: DefId) -> hir_map::DefPathHash;
-    fn def_path_table(&self, cnum: CrateNum) -> Rc<DefPathTable>;
+    fn def_path_table(&self, cnum: CrateNum) -> Lrc<DefPathTable>;
 
     // "queries" used in resolve that aren't tracked for incremental compilation
     fn visibility_untracked(&self, def: DefId) -> ty::Visibility;
@@ -297,7 +297,7 @@ pub struct DummyCrateStore;
 
 #[allow(unused_variables)]
 impl CrateStore for DummyCrateStore {
-    fn crate_data_as_rc_any(&self, krate: CrateNum) -> Rc<Any>
+    fn crate_data_as_rc_any(&self, krate: CrateNum) -> Lrc<Any>
         { bug!("crate_data_as_rc_any") }
     // item info
     fn visibility_untracked(&self, def: DefId) -> ty::Visibility { bug!("visibility") }
@@ -325,7 +325,7 @@ impl CrateStore for DummyCrateStore {
     fn def_path_hash(&self, def: DefId) -> hir_map::DefPathHash {
         bug!("def_path_hash")
     }
-    fn def_path_table(&self, cnum: CrateNum) -> Rc<DefPathTable> {
+    fn def_path_table(&self, cnum: CrateNum) -> Lrc<DefPathTable> {
         bug!("def_path_table")
     }
     fn struct_field_names_untracked(&self, def: DefId) -> Vec<ast::Name> {
@@ -398,7 +398,7 @@ pub fn used_crates(tcx: TyCtxt, prefer: LinkagePreference)
         })
         .collect::<Vec<_>>();
     let mut ordering = tcx.postorder_cnums(LOCAL_CRATE);
-    Rc::make_mut(&mut ordering).reverse();
+    Lrc::make_mut(&mut ordering).reverse();
     libs.sort_by_key(|&(a, _)| {
         ordering.iter().position(|x| *x == a)
     });

src/librustc/middle/cstore.rs

@@ -27,7 +27,7 @@ use middle::region;
 use ty::{self, TyCtxt, adjustment};
 
 use hir::{self, PatKind};
-use std::rc::Rc;
+use rustc_data_structures::sync::Lrc;
 use syntax::ast;
 use syntax::ptr::P;
 use syntax_pos::Span;
@@ -279,7 +279,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx, 'tcx> {
                param_env: ty::ParamEnv<'tcx>,
                region_scope_tree: &'a region::ScopeTree,
                tables: &'a ty::TypeckTables<'tcx>,
-               rvalue_promotable_map: Option<Rc<ItemLocalSet>>)
+               rvalue_promotable_map: Option<Lrc<ItemLocalSet>>)
                -> Self
     {
         ExprUseVisitor {

src/librustc/middle/expr_use_visitor.rs

@@ -85,6 +85,7 @@ use syntax::ast;
 use syntax_pos::Span;
 
 use std::fmt;
+use rustc_data_structures::sync::Lrc;
 use std::rc::Rc;
 use util::nodemap::ItemLocalSet;
 
@@ -286,7 +287,7 @@ pub struct MemCategorizationContext<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     pub tcx: TyCtxt<'a, 'gcx, 'tcx>,
     pub region_scope_tree: &'a region::ScopeTree,
     pub tables: &'a ty::TypeckTables<'tcx>,
-    rvalue_promotable_map: Option<Rc<ItemLocalSet>>,
+    rvalue_promotable_map: Option<Lrc<ItemLocalSet>>,
     infcx: Option<&'a InferCtxt<'a, 'gcx, 'tcx>>,
 }
 
@@ -395,7 +396,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx, 'tcx> {
     pub fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                region_scope_tree: &'a region::ScopeTree,
                tables: &'a ty::TypeckTables<'tcx>,
-               rvalue_promotable_map: Option<Rc<ItemLocalSet>>)
+               rvalue_promotable_map: Option<Lrc<ItemLocalSet>>)
                -> MemCategorizationContext<'a, 'tcx, 'tcx> {
         MemCategorizationContext {
             tcx,

src/librustc/middle/mem_categorization.rs

@@ -18,7 +18,7 @@
 use hir::map as hir_map;
 use hir::def::Def;
 use hir::def_id::{DefId, CrateNum};
-use std::rc::Rc;
+use rustc_data_structures::sync::Lrc;
 use ty::{self, TyCtxt};
 use ty::maps::Providers;
 use middle::privacy;
@@ -377,7 +377,7 @@ impl<'a, 'tcx: 'a> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a,
 // We introduce a new-type here, so we can have a specialized HashStable
 // implementation for it.
 #[derive(Clone)]
-pub struct ReachableSet(pub Rc<NodeSet>);
+pub struct ReachableSet(pub Lrc<NodeSet>);
 
 
 fn reachable_set<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, crate_num: CrateNum) -> ReachableSet {
@@ -425,7 +425,7 @@ fn reachable_set<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, crate_num: CrateNum) ->
     reachable_context.propagate();
 
     // Return the set of reachable symbols.
-    ReachableSet(Rc::new(reachable_context.reachable_symbols))
+    ReachableSet(Lrc::new(reachable_context.reachable_symbols))
 }
 
 pub fn provide(providers: &mut Providers) {

src/librustc/middle/reachable.rs

@@ -20,7 +20,7 @@ use ty;
 
 use std::fmt;
 use std::mem;
-use std::rc::Rc;
+use rustc_data_structures::sync::Lrc;
 use syntax::codemap;
 use syntax::ast;
 use syntax_pos::{Span, DUMMY_SP};
@@ -1436,7 +1436,7 @@ impl<'a, 'tcx> Visitor<'tcx> for RegionResolutionVisitor<'a, 'tcx> {
 }
 
 fn region_scope_tree<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId)
-    -> Rc<ScopeTree>
+    -> Lrc<ScopeTree>
 {
     let closure_base_def_id = tcx.closure_base_def_id(def_id);
     if closure_base_def_id != def_id {
@@ -1478,7 +1478,7 @@ fn region_scope_tree<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId)
         ScopeTree::default()
     };
 
-    Rc::new(scope_tree)
+    Lrc::new(scope_tree)
 }
 
 pub fn provide(providers: &mut Providers) {