Auto merge of #49390 - Zoxc:sync-syntax, r=michaelwoerister

More thread-safety changes

r? @michaelwoerister

5 files changed, 31 insertions, 38 deletions

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index a09bea25a24..c25a7686bea 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -28,7 +28,7 @@ use std::collections::HashMap;
 use std::iter;
 use std::path::PathBuf;
 use std::rc::Rc;
-use rustc_data_structures::sync::Lrc;
+use rustc_data_structures::sync::{self, Lrc};
 use std::default::Default;
 use tokenstream::{self, TokenStream};
 
@@ -565,26 +565,26 @@ pub enum SyntaxExtension {
     /// `#[derive(...)]` is a `MultiItemDecorator`.
     ///
     /// Prefer ProcMacro or MultiModifier since they are more flexible.
-    MultiDecorator(Box<MultiItemDecorator>),
+    MultiDecorator(Box<MultiItemDecorator + sync::Sync + sync::Send>),
 
     /// A syntax extension that is attached to an item and modifies it
     /// in-place. Also allows decoration, i.e., creating new items.
-    MultiModifier(Box<MultiItemModifier>),
+    MultiModifier(Box<MultiItemModifier + sync::Sync + sync::Send>),
 
     /// A function-like procedural macro. TokenStream -> TokenStream.
-    ProcMacro(Box<ProcMacro>),
+    ProcMacro(Box<ProcMacro + sync::Sync + sync::Send>),
 
     /// An attribute-like procedural macro. TokenStream, TokenStream -> TokenStream.
     /// The first TokenSteam is the attribute, the second is the annotated item.
     /// Allows modification of the input items and adding new items, similar to
     /// MultiModifier, but uses TokenStreams, rather than AST nodes.
-    AttrProcMacro(Box<AttrProcMacro>),
+    AttrProcMacro(Box<AttrProcMacro + sync::Sync + sync::Send>),
 
     /// A normal, function-like syntax extension.
     ///
     /// `bytes!` is a `NormalTT`.
     NormalTT {
-        expander: Box<TTMacroExpander>,
+        expander: Box<TTMacroExpander + sync::Sync + sync::Send>,
         def_info: Option<(ast::NodeId, Span)>,
         /// Whether the contents of the macro can
         /// directly use `#[unstable]` things (true == yes).
@@ -599,13 +599,15 @@ pub enum SyntaxExtension {
     /// A function-like syntax extension that has an extra ident before
     /// the block.
     ///
-    IdentTT(Box<IdentMacroExpander>, Option<Span>, bool),
+    IdentTT(Box<IdentMacroExpander + sync::Sync + sync::Send>, Option<Span>, bool),
 
     /// An attribute-like procedural macro. TokenStream -> TokenStream.
     /// The input is the annotated item.
     /// Allows generating code to implement a Trait for a given struct
     /// or enum item.
-    ProcMacroDerive(Box<MultiItemModifier>, Vec<Symbol> /* inert attribute names */),
+    ProcMacroDerive(Box<MultiItemModifier +
+                        sync::Sync +
+                        sync::Send>, Vec<Symbol> /* inert attribute names */),
 
     /// An attribute-like procedural macro that derives a builtin trait.
     BuiltinDerive(BuiltinDeriveFn),
@@ -613,7 +615,7 @@ pub enum SyntaxExtension {
     /// A declarative macro, e.g. `macro m() {}`.
     ///
     /// The second element is the definition site span.
-    DeclMacro(Box<TTMacroExpander>, Option<(ast::NodeId, Span)>),
+    DeclMacro(Box<TTMacroExpander + sync::Sync + sync::Send>, Option<(ast::NodeId, Span)>),
 }
 
 impl SyntaxExtension {
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index c456dc45d21..b1a22724a9a 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -26,6 +26,8 @@
 #![feature(const_atomic_usize_new)]
 #![feature(rustc_attrs)]
 
+#![recursion_limit="256"]
+
 // See librustc_cratesio_shim/Cargo.toml for a comment explaining this.
 #[allow(unused_extern_crates)]
 extern crate rustc_cratesio_shim;
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 152c4c31eb3..39b2f77f230 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -1781,7 +1781,6 @@ mod tests {
     use errors;
     use feature_gate::UnstableFeatures;
     use parse::token;
-    use std::cell::RefCell;
     use std::collections::HashSet;
     use std::io;
     use std::path::PathBuf;
@@ -1797,12 +1796,12 @@ mod tests {
             span_diagnostic: errors::Handler::with_emitter(true, false, Box::new(emitter)),
             unstable_features: UnstableFeatures::from_environment(),
             config: CrateConfig::new(),
-            included_mod_stack: RefCell::new(Vec::new()),
+            included_mod_stack: Lock::new(Vec::new()),
             code_map: cm,
-            missing_fragment_specifiers: RefCell::new(HashSet::new()),
-            raw_identifier_spans: RefCell::new(Vec::new()),
+            missing_fragment_specifiers: Lock::new(HashSet::new()),
+            raw_identifier_spans: Lock::new(Vec::new()),
             registered_diagnostics: Lock::new(ErrorMap::new()),
-            non_modrs_mods: RefCell::new(vec![]),
+            non_modrs_mods: Lock::new(vec![]),
         }
     }
 
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 428b3b136df..ff63c9a5c6d 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -23,7 +23,6 @@ use symbol::Symbol;
 use tokenstream::{TokenStream, TokenTree};
 use diagnostics::plugin::ErrorMap;
 
-use std::cell::RefCell;
 use std::collections::HashSet;
 use std::iter;
 use std::path::{Path, PathBuf};
@@ -46,17 +45,17 @@ pub struct ParseSess {
     pub span_diagnostic: Handler,
     pub unstable_features: UnstableFeatures,
     pub config: CrateConfig,
-    pub missing_fragment_specifiers: RefCell<HashSet<Span>>,
+    pub missing_fragment_specifiers: Lock<HashSet<Span>>,
     /// Places where raw identifiers were used. This is used for feature gating
     /// raw identifiers
-    pub raw_identifier_spans: RefCell<Vec<Span>>,
+    pub raw_identifier_spans: Lock<Vec<Span>>,
     /// The registered diagnostics codes
     pub registered_diagnostics: Lock<ErrorMap>,
     // Spans where a `mod foo;` statement was included in a non-mod.rs file.
     // These are used to issue errors if the non_modrs_mods feature is not enabled.
-    pub non_modrs_mods: RefCell<Vec<(ast::Ident, Span)>>,
+    pub non_modrs_mods: Lock<Vec<(ast::Ident, Span)>>,
     /// Used to determine and report recursive mod inclusions
-    included_mod_stack: RefCell<Vec<PathBuf>>,
+    included_mod_stack: Lock<Vec<PathBuf>>,
     code_map: Lrc<CodeMap>,
 }
 
@@ -75,12 +74,12 @@ impl ParseSess {
             span_diagnostic: handler,
             unstable_features: UnstableFeatures::from_environment(),
             config: HashSet::new(),
-            missing_fragment_specifiers: RefCell::new(HashSet::new()),
-            raw_identifier_spans: RefCell::new(Vec::new()),
+            missing_fragment_specifiers: Lock::new(HashSet::new()),
+            raw_identifier_spans: Lock::new(Vec::new()),
             registered_diagnostics: Lock::new(ErrorMap::new()),
-            included_mod_stack: RefCell::new(vec![]),
+            included_mod_stack: Lock::new(vec![]),
             code_map,
-            non_modrs_mods: RefCell::new(vec![]),
+            non_modrs_mods: Lock::new(vec![]),
         }
     }
 
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index df0ea05005c..8da79f92768 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -25,9 +25,8 @@ use syntax_pos::{self, Span, FileName};
 use tokenstream::{TokenStream, TokenTree};
 use tokenstream;
 
-use std::cell::Cell;
 use std::{cmp, fmt};
-use rustc_data_structures::sync::Lrc;
+use rustc_data_structures::sync::{Lrc, Lock};
 
 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Debug, Copy)]
 pub enum BinOpToken {
@@ -627,15 +626,8 @@ pub fn is_op(tok: &Token) -> bool {
     }
 }
 
-pub struct LazyTokenStream(Cell<Option<TokenStream>>);
-
-impl Clone for LazyTokenStream {
-    fn clone(&self) -> Self {
-        let opt_stream = self.0.take();
-        self.0.set(opt_stream.clone());
-        LazyTokenStream(Cell::new(opt_stream))
-    }
-}
+#[derive(Clone)]
+pub struct LazyTokenStream(Lock<Option<TokenStream>>);
 
 impl cmp::Eq for LazyTokenStream {}
 impl PartialEq for LazyTokenStream {
@@ -652,15 +644,14 @@ impl fmt::Debug for LazyTokenStream {
 
 impl LazyTokenStream {
     pub fn new() -> Self {
-        LazyTokenStream(Cell::new(None))
+        LazyTokenStream(Lock::new(None))
     }
 
     pub fn force<F: FnOnce() -> TokenStream>(&self, f: F) -> TokenStream {
-        let mut opt_stream = self.0.take();
+        let mut opt_stream = self.0.lock();
         if opt_stream.is_none() {
-            opt_stream = Some(f());
+            *opt_stream = Some(f());
         }
-        self.0.set(opt_stream.clone());
         opt_stream.clone().unwrap()
     }
 }