Auto merge of rust-lang#33710 - Manishearth:rollup, r=Manishearth

Rollup of 5 pull requests

- Successful merges: rust-lang#33656, rust-lang#33666, rust-lang#33673, rust-lang#33675, rust-lang#33695
- Failed merges:

Author: bors

src/librustc/traits/mod.rs

@@ -38,6 +38,7 @@ pub use self::select::{EvaluationCache, SelectionContext, SelectionCache};
 pub use self::select::{MethodMatchResult, MethodMatched, MethodAmbiguous, MethodDidNotMatch};
 pub use self::select::{MethodMatchedData}; // intentionally don't export variants
 pub use self::specialize::{OverlapError, specialization_graph, specializes, translate_substs};
+pub use self::specialize::{SpecializesCache};
 pub use self::util::elaborate_predicates;
 pub use self::util::supertraits;
 pub use self::util::Supertraits;

src/librustc/traits/specialize/mod.rs

@@ -20,6 +20,7 @@
 use super::{SelectionContext, FulfillmentContext};
 use super::util::{fresh_type_vars_for_impl, impl_trait_ref_and_oblig};
 
+use rustc_data_structures::fnv::FnvHashMap;
 use hir::def_id::DefId;
 use infer::{InferCtxt, TypeOrigin};
 use middle::region;
@@ -111,6 +112,10 @@ pub fn translate_substs<'a, 'gcx, 'tcx>(infcx: &InferCtxt<'a, 'gcx, 'tcx>,
 pub fn specializes<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                              impl1_def_id: DefId,
                              impl2_def_id: DefId) -> bool {
+    if let Some(r) = tcx.specializes_cache.borrow().check(impl1_def_id, impl2_def_id) {
+        return r;
+    }
+
     // The feature gate should prevent introducing new specializations, but not
     // taking advantage of upstream ones.
     if !tcx.sess.features.borrow().specialization &&
@@ -146,7 +151,7 @@ pub fn specializes<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                              .unwrap()
                              .subst(tcx, &penv.free_substs);
 
-    tcx.normalizing_infer_ctxt(ProjectionMode::Topmost).enter(|mut infcx| {
+    let result = tcx.normalizing_infer_ctxt(ProjectionMode::Topmost).enter(|mut infcx| {
         // Normalize the trait reference, adding any obligations
         // that arise into the impl1 assumptions.
         let Normalized { value: impl1_trait_ref, obligations: normalization_obligations } = {
@@ -167,7 +172,10 @@ pub fn specializes<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
         // Attempt to prove that impl2 applies, given all of the above.
         fulfill_implication(&infcx, impl1_trait_ref, impl2_def_id).is_ok()
-    })
+    });
+
+    tcx.specializes_cache.borrow_mut().insert(impl1_def_id, impl2_def_id, result);
+    result
 }
 
 /// Attempt to fulfill all obligations of `target_impl` after unification with
@@ -225,3 +233,23 @@ fn fulfill_implication<'a, 'gcx, 'tcx>(infcx: &InferCtxt<'a, 'gcx, 'tcx>,
         }
     })
 }
+
+pub struct SpecializesCache {
+    map: FnvHashMap<(DefId, DefId), bool>
+}
+
+impl SpecializesCache {
+    pub fn new() -> Self {
+        SpecializesCache {
+            map: FnvHashMap()
+        }
+    }
+
+    pub fn check(&self, a: DefId, b: DefId) -> Option<bool> {
+        self.map.get(&(a, b)).cloned()
+    }
+
+    pub fn insert(&mut self, a: DefId, b: DefId, result: bool) {
+        self.map.insert((a, b), result);
+    }
+}

src/librustc/ty/context.rs

@@ -291,6 +291,8 @@ impl<'a, 'gcx, 'tcx> Deref for TyCtxt<'a, 'gcx, 'tcx> {
 pub struct GlobalCtxt<'tcx> {
     global_interners: CtxtInterners<'tcx>,
 
+    pub specializes_cache: RefCell<traits::SpecializesCache>,
+
     pub dep_graph: DepGraph,
 
     /// Common types, pre-interned for your convenience.
@@ -637,6 +639,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         let dep_graph = map.dep_graph.clone();
         let fulfilled_predicates = traits::GlobalFulfilledPredicates::new(dep_graph.clone());
         tls::enter_global(GlobalCtxt {
+            specializes_cache: RefCell::new(traits::SpecializesCache::new()),
             global_interners: interners,
             dep_graph: dep_graph.clone(),
             types: common_types,

src/librustc_borrowck/diagnostics.rs

@@ -391,6 +391,7 @@ fn you_know_nothing(jon_snow: &mut i32) {
                        //        but it is already borrowed
     };
 }
+```
 
 In here, `jon_snow` is already borrowed by the `nights_watch` closure, so it
 cannot be borrowed by the `starks` closure at the same time. To fix this issue,

src/librustdoc/clean/mod.rs

@@ -795,7 +795,17 @@ impl Clean<Lifetime> for hir::Lifetime {
 
 impl Clean<Lifetime> for hir::LifetimeDef {
     fn clean(&self, _: &DocContext) -> Lifetime {
-        Lifetime(self.lifetime.name.to_string())
+        if self.bounds.len() > 0 {
+            let mut s = format!("{}: {}",
+                                self.lifetime.name.to_string(),
+                                self.bounds[0].name.to_string());
+            for bound in self.bounds.iter().skip(1) {
+                s.push_str(&format!(" + {}", bound.name.to_string()));
+            }
+            Lifetime(s)
+        } else {
+            Lifetime(self.lifetime.name.to_string())
+        }
     }
 }
 

src/librustdoc/html/static/rustdoc.css

@@ -640,6 +640,10 @@ span.since {
     margin-right: 5px;
 }
 
+:target > code {
+   background: #FDFFD3;
+}
+
 /* Media Queries */
 
 @media (max-width: 700px) {

src/libsyntax_ext/format.rs

@@ -67,8 +67,7 @@ struct Context<'a, 'b:'a> {
 
     name_positions: HashMap<String, usize>,
 
-    /// Updated as arguments are consumed or methods are entered
-    nest_level: usize,
+    /// Updated as arguments are consumed
     next_arg: usize,
 }
 
@@ -164,9 +163,7 @@ impl<'a, 'b> Context<'a, 'b> {
                 let pos = match arg.position {
                     parse::ArgumentNext => {
                         let i = self.next_arg;
-                        if self.check_positional_ok() {
-                            self.next_arg += 1;
-                        }
+                        self.next_arg += 1;
                         Exact(i)
                     }
                     parse::ArgumentIs(i) => Exact(i),
@@ -189,25 +186,13 @@ impl<'a, 'b> Context<'a, 'b> {
                 self.verify_arg_type(Named(s.to_string()), Unsigned);
             }
             parse::CountIsNextParam => {
-                if self.check_positional_ok() {
-                    let next_arg = self.next_arg;
-                    self.verify_arg_type(Exact(next_arg), Unsigned);
-                    self.next_arg += 1;
-                }
+                let next_arg = self.next_arg;
+                self.verify_arg_type(Exact(next_arg), Unsigned);
+                self.next_arg += 1;
             }
         }
     }
 
-    fn check_positional_ok(&mut self) -> bool {
-        if self.nest_level != 0 {
-            self.ecx.span_err(self.fmtsp, "cannot use implicit positional \
-                                           arguments nested inside methods");
-            false
-        } else {
-            true
-        }
-    }
-
     fn describe_num_args(&self) -> String {
         match self.args.len() {
             0 => "no arguments given".to_string(),
@@ -655,7 +640,6 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt, sp: Span,
         name_positions: HashMap::new(),
         name_types: HashMap::new(),
         name_ordering: name_ordering,
-        nest_level: 0,
         next_arg: 0,
         literal: String::new(),
         pieces: Vec::new(),