import trait engine to typeck

14 files changed, 38 insertions, 35 deletions

diff --git a/src/librustc/infer/mod.rs b/src/librustc/infer/mod.rs
index eb693ea3c6a..fe919775da0 100644
--- a/src/librustc/infer/mod.rs
+++ b/src/librustc/infer/mod.rs
@@ -27,7 +27,7 @@ use ty::{self, Ty, TyCtxt};
 use ty::error::{ExpectedFound, TypeError, UnconstrainedNumeric};
 use ty::fold::TypeFoldable;
 use ty::relate::RelateResult;
-use traits::{self, ObligationCause, PredicateObligations, TraitEngine};
+use traits::{self, ObligationCause, PredicateObligations};
 use rustc_data_structures::unify as ut;
 use std::cell::{Cell, RefCell, Ref, RefMut};
 use std::collections::BTreeMap;
diff --git a/src/librustc/infer/outlives/bounds.rs b/src/librustc/infer/outlives/bounds.rs
index 8bb3f4158ff..4bc64acc763 100644
--- a/src/librustc/infer/outlives/bounds.rs
+++ b/src/librustc/infer/outlives/bounds.rs
@@ -11,7 +11,7 @@
 use infer::InferCtxt;
 use syntax::ast;
 use syntax::codemap::Span;
-use traits::FulfillmentContext;
+use traits::{FulfillmentContext, TraitEngine};
 use ty::{self, Ty, TypeFoldable};
 use ty::outlives::Component;
 use ty::wf;
diff --git a/src/librustc/traits/engine.rs b/src/librustc/traits/engine.rs
index 17cd7d8d9c7..317fe2cc273 100644
--- a/src/librustc/traits/engine.rs
+++ b/src/librustc/traits/engine.rs
@@ -16,13 +16,6 @@ use super::{FulfillmentContext, FulfillmentError};
 use super::{ObligationCause, PredicateObligation, PendingPredicateObligation};
 
 pub trait TraitEngine<'tcx> {
-    /// "Normalize" a projection type `<SomeType as SomeTrait>::X` by
-    /// creating a fresh type variable `$0` as well as a projection
-    /// predicate `<SomeType as SomeTrait>::X == $0`. When the
-    /// inference engine runs, it will attempt to find an impl of
-    /// `SomeTrait` or a where clause that lets us unify `$0` with
-    /// something concrete. If this fails, we'll unify `$0` with
-    /// `projection_ty` again.
     fn normalize_projection_type<'a, 'gcx>(
         &mut self,
         infcx: &InferCtxt<'a, 'gcx, 'tcx>,
@@ -31,9 +24,6 @@ pub trait TraitEngine<'tcx> {
         cause: ObligationCause<'tcx>,
     ) -> Ty<'tcx>;
 
-    /// Requires that `ty` must implement the trait with `def_id` in
-    /// the given environment. This trait must not have any type
-    /// parameters (except for `Self`).
     fn register_bound<'a, 'gcx>(
         &mut self,
         infcx: &InferCtxt<'a, 'gcx, 'tcx>,
@@ -62,8 +52,19 @@ pub trait TraitEngine<'tcx> {
     fn pending_obligations(&self) -> Vec<PendingPredicateObligation<'tcx>>;
 }
 
-impl<'tcx> dyn TraitEngine<'tcx> {
-    pub fn new(_tcx: TyCtxt<'_, '_, 'tcx>) -> Box<Self> {
-        Box::new(FulfillmentContext::new())
-    }
+impl<'a, 'gcx, 'tcx> dyn TraitEngine<'tcx> +'tcx {
+   pub fn new(_tcx: TyCtxt<'_, '_, 'tcx>) -> Box<Self + 'tcx>
+   {
+       Box::new(FulfillmentContext::new())
+   }
+
+   pub fn register_predicate_obligations<I>(&mut self,
+                                            infcx: &InferCtxt<'a, 'gcx, 'tcx>,
+                                            obligations: I)
+       where I: IntoIterator<Item = PredicateObligation<'tcx>>
+   {
+       for obligation in obligations {
+           self.register_predicate_obligation(infcx, obligation);
+       }
+   }
 }
diff --git a/src/librustc/traits/fulfill.rs b/src/librustc/traits/fulfill.rs
index 3e4c4b2cae0..1c091d68a2e 100644
--- a/src/librustc/traits/fulfill.rs
+++ b/src/librustc/traits/fulfill.rs
@@ -85,7 +85,7 @@ impl<'a, 'gcx, 'tcx> FulfillmentContext<'tcx> {
             register_region_obligations: false
         }
     }
-    
+
     pub fn register_predicate_obligations<I>(&mut self,
                                              infcx: &InferCtxt<'a, 'gcx, 'tcx>,
                                              obligations: I)
@@ -217,8 +217,8 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
     }
 
     fn select_all_or_error<'a, 'gcx>(&mut self,
-                           infcx: &InferCtxt<'a, 'gcx, 'tcx>)
-                           -> Result<(),Vec<FulfillmentError<'tcx>>>
+                                     infcx: &InferCtxt<'a, 'gcx, 'tcx>)
+                                     -> Result<(),Vec<FulfillmentError<'tcx>>>
     {
         self.select_where_possible(infcx)?;
 
diff --git a/src/librustc/traits/mod.rs b/src/librustc/traits/mod.rs
index 64b939dddc9..1d5d3e41c9c 100644
--- a/src/librustc/traits/mod.rs
+++ b/src/librustc/traits/mod.rs
@@ -45,6 +45,7 @@ pub use self::select::{EvaluationCache, SelectionContext, SelectionCache};
 pub use self::select::IntercrateAmbiguityCause;
 pub use self::specialize::{OverlapError, specialization_graph, translate_substs};
 pub use self::specialize::{SpecializesCache, find_associated_item};
+pub use self::engine::TraitEngine;
 pub use self::util::elaborate_predicates;
 pub use self::util::supertraits;
 pub use self::util::Supertraits;
diff --git a/src/librustc/traits/specialize/mod.rs b/src/librustc/traits/specialize/mod.rs
index 5ea089abb8e..a9d1c8bcc3d 100644
--- a/src/librustc/traits/specialize/mod.rs
+++ b/src/librustc/traits/specialize/mod.rs
@@ -26,7 +26,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use hir::def_id::DefId;
 use infer::{InferCtxt, InferOk};
 use ty::subst::{Subst, Substs};
-use traits::{self, ObligationCause};
+use traits::{self, ObligationCause, TraitEngine};
 use traits::select::IntercrateAmbiguityCause;
 use ty::{self, TyCtxt, TypeFoldable};
 use syntax_pos::DUMMY_SP;
diff --git a/src/librustc/traits/trans/mod.rs b/src/librustc/traits/trans/mod.rs
index ba39d796147..31e851126d7 100644
--- a/src/librustc/traits/trans/mod.rs
+++ b/src/librustc/traits/trans/mod.rs
@@ -18,7 +18,8 @@ use std::marker::PhantomData;
 use syntax_pos::DUMMY_SP;
 use infer::InferCtxt;
 use syntax_pos::Span;
-use traits::{FulfillmentContext, Obligation, ObligationCause, SelectionContext, TraitEngine, Vtable};
+use traits::{FulfillmentContext, Obligation, ObligationCause, SelectionContext,
+             TraitEngine, Vtable};
 use ty::{self, Ty, TyCtxt};
 use ty::subst::{Subst, Substs};
 use ty::fold::TypeFoldable;
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index 022831b5a92..b9ba0af2346 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -20,7 +20,7 @@ use dataflow::move_paths::MoveData;
 use rustc::hir::def_id::DefId;
 use rustc::infer::{InferCtxt, InferOk, InferResult, LateBoundRegionConversionTime, UnitResult};
 use rustc::infer::region_constraints::{GenericKind, RegionConstraintData};
-use rustc::traits::{self, Normalized, FulfillmentContext};
+use rustc::traits::{self, Normalized, TraitEngine};
 use rustc::traits::query::NoSolution;
 use rustc::ty::error::TypeError;
 use rustc::ty::fold::TypeFoldable;
@@ -662,7 +662,7 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
     where
         OP: FnOnce(&mut Self) -> InferResult<'tcx, R>,
     {
-        let mut fulfill_cx = FulfillmentContext::new();
+        let mut fulfill_cx = TraitEngine::new(self.infcx.tcx);
         let InferOk { value, obligations } = self.infcx.commit_if_ok(|_| op(self))?;
         fulfill_cx.register_predicate_obligations(self.infcx, obligations);
         if let Err(e) = fulfill_cx.select_all_or_error(self.infcx) {
diff --git a/src/librustc_mir/transform/qualify_consts.rs b/src/librustc_mir/transform/qualify_consts.rs
index 59a872a23b0..8fe9f6bad1b 100644
--- a/src/librustc_mir/transform/qualify_consts.rs
+++ b/src/librustc_mir/transform/qualify_consts.rs
@@ -21,7 +21,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc::hir;
 use rustc::hir::def_id::DefId;
 use rustc::middle::const_val::ConstVal;
-use rustc::traits;
+use rustc::traits::{self, TraitEngine};
 use rustc::ty::{self, TyCtxt, Ty, TypeFoldable};
 use rustc::ty::cast::CastTy;
 use rustc::ty::maps::Providers;
diff --git a/src/librustc_traits/util.rs b/src/librustc_traits/util.rs
index 976eb442a0d..bff070ab73d 100644
--- a/src/librustc_traits/util.rs
+++ b/src/librustc_traits/util.rs
@@ -12,7 +12,7 @@ use rustc::infer::InferCtxt;
 use rustc::infer::canonical::{CanonicalVarValues, Canonicalize, Certainty, QueryRegionConstraints,
                               QueryResult};
 use rustc::infer::region_constraints::{Constraint, RegionConstraintData};
-use rustc::traits::FulfillmentContext;
+use rustc::traits::{FulfillmentContext, TraitEngine};
 use rustc::traits::query::NoSolution;
 use rustc::ty;
 use std::fmt::Debug;
diff --git a/src/librustc_typeck/check/dropck.rs b/src/librustc_typeck/check/dropck.rs
index 3a13e2fe294..d508b6df924 100644
--- a/src/librustc_typeck/check/dropck.rs
+++ b/src/librustc_typeck/check/dropck.rs
@@ -16,7 +16,7 @@ use rustc::infer::outlives::env::OutlivesEnvironment;
 use rustc::middle::region;
 use rustc::ty::subst::{Subst, Substs, UnpackedKind};
 use rustc::ty::{self, Ty, TyCtxt};
-use rustc::traits::{self, ObligationCause, TraitEngine};
+use rustc::traits::{ObligationCause, TraitEngine};
 use util::common::ErrorReported;
 
 use syntax::ast;
@@ -84,7 +84,7 @@ fn ensure_drop_params_and_item_params_correspond<'a, 'tcx>(
     tcx.infer_ctxt().enter(|ref infcx| {
         let impl_param_env = tcx.param_env(self_type_did);
         let tcx = infcx.tcx;
-        let mut fulfillment_cx = TraitEngine::new();
+        let mut fulfillment_cx = TraitEngine::new(tcx);
 
         let named_type = tcx.type_of(self_type_did);
 
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 3ecdb4e5cec..2336742968b 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -95,8 +95,7 @@ use rustc::infer::type_variable::{TypeVariableOrigin};
 use rustc::middle::region;
 use rustc::mir::interpret::{GlobalId};
 use rustc::ty::subst::{Kind, Subst, Substs};
-use rustc::traits::{self, ObligationCause, ObligationCauseCode};
-use rustc::traits::engine::TraitEngine;
+use rustc::traits::{self, ObligationCause, ObligationCauseCode, TraitEngine};
 use rustc::ty::{self, Ty, TyCtxt, Visibility, ToPredicate};
 use rustc::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
 use rustc::ty::fold::TypeFoldable;
@@ -635,7 +634,7 @@ impl<'a, 'gcx, 'tcx> Inherited<'a, 'gcx, 'tcx> {
                 maybe_tables: infcx.in_progress_tables,
             },
             infcx,
-            fulfillment_cx: RefCell::new(TraitEngine::new()),
+            fulfillment_cx: RefCell::new(TraitEngine::new(tcx)),
             locals: RefCell::new(NodeMap()),
             deferred_call_resolutions: RefCell::new(DefIdMap()),
             deferred_cast_checks: RefCell::new(Vec::new()),
@@ -2883,7 +2882,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 // is polymorphic) and the expected return type.
                 // No argument expectations are produced if unification fails.
                 let origin = self.misc(call_span);
-                let ures = self.at(&origin, self.param_env).sup(ret_ty, formal_ret);
+                let ures = self.at(&origin, self.param_env).sup(ret_ty, &formal_ret);
 
                 // FIXME(#27336) can't use ? here, Try::from_error doesn't default
                 // to identity so the resulting type is not constrained.
@@ -2894,7 +2893,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                         // out unconstrained or ambiguous, as we're
                         // just trying to get hints here.
                         self.save_and_restore_in_snapshot_flag(|_| {
-                            let mut fulfill = TraitEngine::new();
+                            let mut fulfill = TraitEngine::new(self.tcx);
                             for obligation in ok.obligations {
                                 fulfill.register_predicate_obligation(self, obligation);
                             }
diff --git a/src/librustc_typeck/coherence/builtin.rs b/src/librustc_typeck/coherence/builtin.rs
index 9700aa6bc54..8a1f827749a 100644
--- a/src/librustc_typeck/coherence/builtin.rs
+++ b/src/librustc_typeck/coherence/builtin.rs
@@ -372,7 +372,7 @@ pub fn coerce_unsized_info<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
             }
         };
 
-        let mut fulfill_cx = TraitEngine::new();
+        let mut fulfill_cx = TraitEngine::new(tcx);
 
         // Register an obligation for `A: Trait<B>`.
         let cause = traits::ObligationCause::misc(span, impl_node_id);
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index 7f61ecb83db..de81de59a05 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -88,6 +88,7 @@ This API is completely unstable and subject to change.
 #![feature(slice_patterns)]
 #![feature(i128_type)]
 #![cfg_attr(stage0, feature(never_type))]
+#![feature(dyn_trait)]
 
 #[macro_use] extern crate log;
 #[macro_use] extern crate syntax;
@@ -111,7 +112,7 @@ use rustc::infer::InferOk;
 use rustc::ty::subst::Substs;
 use rustc::ty::{self, Ty, TyCtxt};
 use rustc::ty::maps::Providers;
-use rustc::traits::{FulfillmentContext, ObligationCause, ObligationCauseCode, TraitEngine};
+use rustc::traits::{ObligationCause, ObligationCauseCode, TraitEngine};
 use session::{CompileIncomplete, config};
 use util::common::time;
 
@@ -160,7 +161,7 @@ fn require_same_types<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                 -> bool {
     tcx.infer_ctxt().enter(|ref infcx| {
         let param_env = ty::ParamEnv::empty();
-        let mut fulfill_cx = TraitEngine::new();
+        let mut fulfill_cx = TraitEngine::new(infcx.tcx);
         match infcx.at(&cause, param_env).eq(expected, actual) {
             Ok(InferOk { obligations, .. }) => {
                 fulfill_cx.register_predicate_obligations(infcx, obligations);