Auto merge of #49558 - Zoxc:sync-misc, r=michaelwoerister

Even more thread-safety changes

r? @michaelwoerister

Author: bors

src/librustc/dep_graph/dep_node.rs

@@ -632,6 +632,7 @@ define_dep_nodes!( <'tcx>
     [input] MaybeUnusedTraitImport(DefId),
     [input] MaybeUnusedExternCrates,
     [eval_always] StabilityIndex,
+    [eval_always] AllTraits,
     [input] AllCrateNums,
     [] ExportedSymbols(CrateNum),
     [eval_always] CollectAndPartitionTranslationItems,

src/librustc/infer/canonical.rs

@@ -36,13 +36,13 @@ use rustc_data_structures::indexed_vec::Idx;
 use serialize::UseSpecializedDecodable;
 use std::fmt::Debug;
 use std::ops::Index;
+use std::sync::atomic::Ordering;
 use syntax::codemap::Span;
 use traits::{Obligation, ObligationCause, PredicateObligation};
 use ty::{self, CanonicalVar, Lift, Region, Slice, Ty, TyCtxt, TypeFlags};
 use ty::subst::{Kind, UnpackedKind};
 use ty::fold::{TypeFoldable, TypeFolder};
 use util::captures::Captures;
-use util::common::CellUsizeExt;
 
 use rustc_data_structures::indexed_vec::IndexVec;
 use rustc_data_structures::fx::FxHashMap;
@@ -473,7 +473,7 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> {
     where
         V: Canonicalize<'gcx, 'tcx>,
     {
-        self.tcx.sess.perf_stats.queries_canonicalized.increment();
+        self.tcx.sess.perf_stats.queries_canonicalized.fetch_add(1, Ordering::Relaxed);
 
         Canonicalizer::canonicalize(
             value,

src/librustc/middle/dead.rs

@@ -408,7 +408,7 @@ fn create_and_seed_worklist<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     }
 
     // Seed entry point
-    if let Some((id, _)) = *tcx.sess.entry_fn.borrow() {
+    if let Some((id, _, _)) = *tcx.sess.entry_fn.borrow() {
         worklist.push(id);
     }
 

src/librustc/middle/dependency_format.rs

@@ -94,13 +94,14 @@ pub enum Linkage {
 
 pub fn calculate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
     let sess = &tcx.sess;
-    let mut fmts = sess.dependency_formats.borrow_mut();
+    let mut fmts = FxHashMap();
     for &ty in sess.crate_types.borrow().iter() {
         let linkage = calculate_type(tcx, ty);
         verify_ok(tcx, &linkage);
         fmts.insert(ty, linkage);
     }
     sess.abort_if_errors();
+    sess.dependency_formats.set(fmts);
 }
 
 fn calculate_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
@@ -222,7 +223,7 @@ fn calculate_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     //
     // Things like allocators and panic runtimes may not have been activated
     // quite yet, so do so here.
-    activate_injected_dep(sess.injected_panic_runtime.get(), &mut ret,
+    activate_injected_dep(*sess.injected_panic_runtime.get(), &mut ret,
                           &|cnum| tcx.is_panic_runtime(cnum));
     activate_injected_allocator(sess, &mut ret);
 
@@ -301,7 +302,7 @@ fn attempt_static<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Option<DependencyLis
     // Our allocator/panic runtime may not have been linked above if it wasn't
     // explicitly linked, which is the case for any injected dependency. Handle
     // that here and activate them.
-    activate_injected_dep(sess.injected_panic_runtime.get(), &mut ret,
+    activate_injected_dep(*sess.injected_panic_runtime.get(), &mut ret,
                           &|cnum| tcx.is_panic_runtime(cnum));
     activate_injected_allocator(sess, &mut ret);
 

src/librustc/middle/entry.rs

@@ -63,12 +63,13 @@ pub fn find_entry_point(session: &Session,
     });
     if !any_exe {
         // No need to find a main function
+        session.entry_fn.set(None);
         return
     }
 
     // If the user wants no main function at all, then stop here.
     if attr::contains_name(&hir_map.krate().attrs, "no_main") {
-        session.entry_type.set(Some(config::EntryNone));
+        session.entry_fn.set(None);
         return
     }
 
@@ -153,17 +154,15 @@ fn find_item(item: &Item, ctxt: &mut EntryContext, at_root: bool) {
 }
 
 fn configure_main(this: &mut EntryContext, crate_name: &str) {
-    if this.start_fn.is_some() {
-        *this.session.entry_fn.borrow_mut() = this.start_fn;
-        this.session.entry_type.set(Some(config::EntryStart));
-    } else if this.attr_main_fn.is_some() {
-        *this.session.entry_fn.borrow_mut() = this.attr_main_fn;
-        this.session.entry_type.set(Some(config::EntryMain));
-    } else if this.main_fn.is_some() {
-        *this.session.entry_fn.borrow_mut() = this.main_fn;
-        this.session.entry_type.set(Some(config::EntryMain));
+    if let Some((node_id, span)) = this.start_fn {
+        this.session.entry_fn.set(Some((node_id, span, config::EntryStart)));
+    } else if let Some((node_id, span)) = this.attr_main_fn {
+        this.session.entry_fn.set(Some((node_id, span, config::EntryMain)));
+    } else if let Some((node_id, span)) = this.main_fn {
+        this.session.entry_fn.set(Some((node_id, span, config::EntryMain)));
     } else {
         // No main function
+        this.session.entry_fn.set(None);
         let mut err = struct_err!(this.session, E0601,
             "`main` function not found in crate `{}`", crate_name);
         if !this.non_main_fns.is_empty() {

src/librustc/middle/recursion_limit.rs

@@ -18,17 +18,17 @@
 use session::Session;
 use syntax::ast;
 
-use std::cell::Cell;
+use rustc_data_structures::sync::Once;
 
 pub fn update_limits(sess: &Session, krate: &ast::Crate) {
     update_limit(sess, krate, &sess.recursion_limit, "recursion_limit",
-                 "recursion limit");
+                 "recursion limit", 64);
     update_limit(sess, krate, &sess.type_length_limit, "type_length_limit",
-                 "type length limit");
+                 "type length limit", 1048576);
 }
 
-fn update_limit(sess: &Session, krate: &ast::Crate, limit: &Cell<usize>,
-                name: &str, description: &str) {
+fn update_limit(sess: &Session, krate: &ast::Crate, limit: &Once<usize>,
+                name: &str, description: &str, default: usize) {
     for attr in &krate.attrs {
         if !attr.check_name(name) {
             continue;
@@ -45,4 +45,5 @@ fn update_limit(sess: &Session, krate: &ast::Crate, limit: &Cell<usize>,
                   "malformed {} attribute, expected #![{}=\"N\"]",
                   description, name);
     }
+    limit.set(default);
 }

src/librustc/session/config.rs

@@ -614,13 +614,11 @@ impl Options {
 
 // The type of entry function, so
 // users can have their own entry
-// functions that don't start a
-// scheduler
+// functions
 #[derive(Copy, Clone, PartialEq)]
 pub enum EntryFnType {
     EntryMain,
     EntryStart,
-    EntryNone,
 }
 
 #[derive(Copy, PartialEq, PartialOrd, Clone, Ord, Eq, Hash, Debug)]
@@ -1861,6 +1859,13 @@ pub fn build_session_options_and_crate_config(
         );
     }
 
+    if debugging_opts.query_threads.unwrap_or(1) > 1 && debugging_opts.fuel.is_some() {
+        early_error(
+            error_format,
+            "Optimization fuel is incompatible with multiple query threads",
+        );
+    }
+
     if codegen_units == Some(0) {
         early_error(
             error_format,