Auto merge of #33632 - Manishearth:rollup, r=Manishearth

Rollup of 9 pull requests

- Successful merges: #33544, #33552, #33554, #33555, #33560, #33566, #33572, #33574, #33576
- Failed merges:

38 files changed, 1182 insertions, 943 deletions

diff --git a/src/librustc/traits/mod.rs b/src/librustc/traits/mod.rs
index f606d73a549..65df056fd42 100644
--- a/src/librustc/traits/mod.rs
+++ b/src/librustc/traits/mod.rs
@@ -239,7 +239,7 @@ pub enum Vtable<'tcx, N> {
     VtableParam(Vec<N>),
 
     /// Virtual calls through an object
-    VtableObject(VtableObjectData<'tcx>),
+    VtableObject(VtableObjectData<'tcx, N>),
 
     /// Successful resolution for a builtin trait.
     VtableBuiltin(VtableBuiltinData<N>),
@@ -250,7 +250,7 @@ pub enum Vtable<'tcx, N> {
     VtableClosure(VtableClosureData<'tcx, N>),
 
     /// Same as above, but for a fn pointer type with the given signature.
-    VtableFnPointer(ty::Ty<'tcx>),
+    VtableFnPointer(VtableFnPointerData<'tcx, N>),
 }
 
 /// Identifies a particular impl in the source, along with a set of
@@ -293,14 +293,22 @@ pub struct VtableBuiltinData<N> {
 /// A vtable for some object-safe trait `Foo` automatically derived
 /// for the object type `Foo`.
 #[derive(PartialEq,Eq,Clone)]
-pub struct VtableObjectData<'tcx> {
+pub struct VtableObjectData<'tcx, N> {
     /// `Foo` upcast to the obligation trait. This will be some supertrait of `Foo`.
     pub upcast_trait_ref: ty::PolyTraitRef<'tcx>,
 
     /// The vtable is formed by concatenating together the method lists of
     /// the base object trait and all supertraits; this is the start of
     /// `upcast_trait_ref`'s methods in that vtable.
-    pub vtable_base: usize
+    pub vtable_base: usize,
+
+    pub nested: Vec<N>,
+}
+
+#[derive(Clone, PartialEq, Eq)]
+pub struct VtableFnPointerData<'tcx, N> {
+    pub fn_ty: ty::Ty<'tcx>,
+    pub nested: Vec<N>
 }
 
 /// Creates predicate obligations from the generic bounds.
@@ -569,7 +577,20 @@ impl<'tcx, N> Vtable<'tcx, N> {
             VtableBuiltin(i) => i.nested,
             VtableDefaultImpl(d) => d.nested,
             VtableClosure(c) => c.nested,
-            VtableObject(_) | VtableFnPointer(..) => vec![]
+            VtableObject(d) => d.nested,
+            VtableFnPointer(d) => d.nested,
+        }
+    }
+
+    fn nested_obligations_mut(&mut self) -> &mut Vec<N> {
+        match self {
+            &mut VtableImpl(ref mut i) => &mut i.nested,
+            &mut VtableParam(ref mut n) => n,
+            &mut VtableBuiltin(ref mut i) => &mut i.nested,
+            &mut VtableDefaultImpl(ref mut d) => &mut d.nested,
+            &mut VtableClosure(ref mut c) => &mut c.nested,
+            &mut VtableObject(ref mut d) => &mut d.nested,
+            &mut VtableFnPointer(ref mut d) => &mut d.nested,
         }
     }
 
@@ -578,18 +599,25 @@ impl<'tcx, N> Vtable<'tcx, N> {
             VtableImpl(i) => VtableImpl(VtableImplData {
                 impl_def_id: i.impl_def_id,
                 substs: i.substs,
-                nested: i.nested.into_iter().map(f).collect()
+                nested: i.nested.into_iter().map(f).collect(),
             }),
             VtableParam(n) => VtableParam(n.into_iter().map(f).collect()),
             VtableBuiltin(i) => VtableBuiltin(VtableBuiltinData {
-                nested: i.nested.into_iter().map(f).collect()
+                nested: i.nested.into_iter().map(f).collect(),
+            }),
+            VtableObject(o) => VtableObject(VtableObjectData {
+                upcast_trait_ref: o.upcast_trait_ref,
+                vtable_base: o.vtable_base,
+                nested: o.nested.into_iter().map(f).collect(),
             }),
-            VtableObject(o) => VtableObject(o),
             VtableDefaultImpl(d) => VtableDefaultImpl(VtableDefaultImplData {
                 trait_def_id: d.trait_def_id,
-                nested: d.nested.into_iter().map(f).collect()
+                nested: d.nested.into_iter().map(f).collect(),
+            }),
+            VtableFnPointer(p) => VtableFnPointer(VtableFnPointerData {
+                fn_ty: p.fn_ty,
+                nested: p.nested.into_iter().map(f).collect(),
             }),
-            VtableFnPointer(f) => VtableFnPointer(f),
             VtableClosure(c) => VtableClosure(VtableClosureData {
                 closure_def_id: c.closure_def_id,
                 substs: c.substs,
diff --git a/src/librustc/traits/project.rs b/src/librustc/traits/project.rs
index 4c338219ffb..9abb179f288 100644
--- a/src/librustc/traits/project.rs
+++ b/src/librustc/traits/project.rs
@@ -19,6 +19,7 @@ use super::PredicateObligation;
 use super::SelectionContext;
 use super::SelectionError;
 use super::VtableClosureData;
+use super::VtableFnPointerData;
 use super::VtableImplData;
 use super::util;
 
@@ -158,7 +159,7 @@ enum ProjectionTyCandidate<'tcx> {
     Closure(VtableClosureData<'tcx, PredicateObligation<'tcx>>),
 
     // fn pointer return type
-    FnPointer(Ty<'tcx>),
+    FnPointer(VtableFnPointerData<'tcx, PredicateObligation<'tcx>>),
 }
 
 struct ProjectionTyCandidateSet<'tcx> {
@@ -218,10 +219,7 @@ fn project_and_unify_type<'cx, 'gcx, 'tcx>(
                                             obligation.cause.clone(),
                                             obligation.recursion_depth) {
             Some(n) => n,
-            None => {
-                consider_unification_despite_ambiguity(selcx, obligation);
-                return Ok(None);
-            }
+            None => return Ok(None),
         };
 
     debug!("project_and_unify_type: normalized_ty={:?} obligations={:?}",
@@ -240,59 +238,6 @@ fn project_and_unify_type<'cx, 'gcx, 'tcx>(
     }
 }
 
-fn consider_unification_despite_ambiguity<'cx, 'gcx, 'tcx>(
-    selcx: &mut SelectionContext<'cx, 'gcx, 'tcx>,
-    obligation: &ProjectionObligation<'tcx>)
-{
-    debug!("consider_unification_despite_ambiguity(obligation={:?})",
-           obligation);
-
-    let def_id = obligation.predicate.projection_ty.trait_ref.def_id;
-    match selcx.tcx().lang_items.fn_trait_kind(def_id) {
-        Some(_) => { }
-        None => { return; }
-    }
-
-    let infcx = selcx.infcx();
-    let self_ty = obligation.predicate.projection_ty.trait_ref.self_ty();
-    let self_ty = infcx.shallow_resolve(self_ty);
-    debug!("consider_unification_despite_ambiguity: self_ty.sty={:?}",
-           self_ty.sty);
-    match self_ty.sty {
-        ty::TyClosure(closure_def_id, substs) => {
-            let closure_typer = selcx.closure_typer();
-            let closure_type = closure_typer.closure_type(closure_def_id, substs);
-            let ty::Binder((_, ret_type)) =
-                infcx.tcx.closure_trait_ref_and_return_type(def_id,
-                                                            self_ty,
-                                                            &closure_type.sig,
-                                                            util::TupleArgumentsFlag::No);
-            // We don't have to normalize the return type here - this is only
-            // reached for TyClosure: Fn inputs where the closure kind is
-            // still unknown, which should only occur in typeck where the
-            // closure type is already normalized.
-            let (ret_type, _) =
-                infcx.replace_late_bound_regions_with_fresh_var(
-                    obligation.cause.span,
-                    infer::AssocTypeProjection(obligation.predicate.projection_ty.item_name),
-                    &ty::Binder(ret_type));
-
-            debug!("consider_unification_despite_ambiguity: ret_type={:?}",
-                   ret_type);
-            let origin = TypeOrigin::RelateOutputImplTypes(obligation.cause.span);
-            let obligation_ty = obligation.predicate.ty;
-            match infcx.eq_types(true, origin, obligation_ty, ret_type) {
-                Ok(InferOk { obligations, .. }) => {
-                    // FIXME(#32730) propagate obligations
-                    assert!(obligations.is_empty());
-                }
-                Err(_) => { /* ignore errors */ }
-            }
-        }
-        _ => { }
-    }
-}
-
 /// Normalizes any associated type projections in `value`, replacing
 /// them with a fully resolved type where possible. The return value
 /// combines the normalized result and any additional obligations that
@@ -929,9 +874,9 @@ fn assemble_candidates_from_impls<'cx, 'gcx, 'tcx>(
             candidate_set.vec.push(
                 ProjectionTyCandidate::Closure(data));
         }
-        super::VtableFnPointer(fn_type) => {
+        super::VtableFnPointer(data) => {
             candidate_set.vec.push(
-                ProjectionTyCandidate::FnPointer(fn_type));
+                ProjectionTyCandidate::FnPointer(data));
         }
         super::VtableParam(..) => {
             // This case tell us nothing about the value of an
@@ -997,8 +942,8 @@ fn confirm_candidate<'cx, 'gcx, 'tcx>(
             confirm_closure_candidate(selcx, obligation, closure_vtable)
         }
 
-        ProjectionTyCandidate::FnPointer(fn_type) => {
-            confirm_fn_pointer_candidate(selcx, obligation, fn_type)
+        ProjectionTyCandidate::FnPointer(fn_pointer_vtable) => {
+            confirm_fn_pointer_candidate(selcx, obligation, fn_pointer_vtable)
         }
     }
 }
@@ -1006,10 +951,13 @@ fn confirm_candidate<'cx, 'gcx, 'tcx>(
 fn confirm_fn_pointer_candidate<'cx, 'gcx, 'tcx>(
     selcx: &mut SelectionContext<'cx, 'gcx, 'tcx>,
     obligation: &ProjectionTyObligation<'tcx>,
-    fn_type: Ty<'tcx>)
+    fn_pointer_vtable: VtableFnPointerData<'tcx, PredicateObligation<'tcx>>)
     -> (Ty<'tcx>, Vec<PredicateObligation<'tcx>>)
 {
-    let fn_type = selcx.infcx().shallow_resolve(fn_type);
+    // FIXME(#32730) propagate obligations (fn pointer vtable nested obligations ONLY come from
+    // unification in inference)
+    assert!(fn_pointer_vtable.nested.is_empty());
+    let fn_type = selcx.infcx().shallow_resolve(fn_pointer_vtable.fn_ty);
     let sig = fn_type.fn_sig();
     confirm_callable_candidate(selcx, obligation, sig, util::TupleArgumentsFlag::Yes)
 }
diff --git a/src/librustc/traits/select.rs b/src/librustc/traits/select.rs
index 7d9a256a6e0..5307749b87b 100644
--- a/src/librustc/traits/select.rs
+++ b/src/librustc/traits/select.rs
@@ -30,7 +30,7 @@ use super::SelectionResult;
 use super::{VtableBuiltin, VtableImpl, VtableParam, VtableClosure,
             VtableFnPointer, VtableObject, VtableDefaultImpl};
 use super::{VtableImplData, VtableObjectData, VtableBuiltinData,
-            VtableClosureData, VtableDefaultImplData};
+            VtableClosureData, VtableDefaultImplData, VtableFnPointerData};
 use super::util;
 
 use hir::def_id::DefId;
@@ -42,13 +42,24 @@ use traits;
 use ty::fast_reject;
 use ty::relate::TypeRelation;
 
+use rustc_data_structures::snapshot_vec::{SnapshotVecDelegate, SnapshotVec};
 use std::cell::RefCell;
 use std::fmt;
+use std::marker::PhantomData;
 use std::rc::Rc;
 use syntax::abi::Abi;
 use hir;
 use util::nodemap::FnvHashMap;
 
+struct InferredObligationsSnapshotVecDelegate<'tcx> {
+    phantom: PhantomData<&'tcx i32>,
+}
+impl<'tcx> SnapshotVecDelegate for InferredObligationsSnapshotVecDelegate<'tcx> {
+    type Value = PredicateObligation<'tcx>;
+    type Undo = ();
+    fn reverse(_: &mut Vec<Self::Value>, _: Self::Undo) {}
+}
+
 pub struct SelectionContext<'cx, 'gcx: 'cx+'tcx, 'tcx: 'cx> {
     infcx: &'cx InferCtxt<'cx, 'gcx, 'tcx>,
 
@@ -74,6 +85,8 @@ pub struct SelectionContext<'cx, 'gcx: 'cx+'tcx, 'tcx: 'cx> {
     /// there is no type that the user could *actually name* that
     /// would satisfy it. This avoids crippling inference, basically.
     intercrate: bool,
+
+    inferred_obligations: SnapshotVec<InferredObligationsSnapshotVecDelegate<'tcx>>,
 }
 
 // A stack that walks back up the stack frame.
@@ -300,6 +313,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             infcx: infcx,
             freshener: infcx.freshener(),
             intercrate: false,
+            inferred_obligations: SnapshotVec::new(),
         }
     }
 
@@ -308,6 +322,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             infcx: infcx,
             freshener: infcx.freshener(),
             intercrate: true,
+            inferred_obligations: SnapshotVec::new(),
         }
     }
 
@@ -331,6 +346,46 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         self.infcx.projection_mode()
     }
 
+    /// Wraps the inference context's in_snapshot s.t. snapshot handling is only from the selection
+    /// context's self.
+    fn in_snapshot<R, F>(&mut self, f: F) -> R
+        where F: FnOnce(&mut Self, &infer::CombinedSnapshot) -> R
+    {
+        // The irrefutable nature of the operation means we don't need to snapshot the
+        // inferred_obligations vector.
+        self.infcx.in_snapshot(|snapshot| f(self, snapshot))
+    }
+
+    /// Wraps a probe s.t. obligations collected during it are ignored and old obligations are
+    /// retained.
+    fn probe<R, F>(&mut self, f: F) -> R
+        where F: FnOnce(&mut Self, &infer::CombinedSnapshot) -> R
+    {
+        let inferred_obligations_snapshot = self.inferred_obligations.start_snapshot();
+        let result = self.infcx.probe(|snapshot| f(self, snapshot));
+        self.inferred_obligations.rollback_to(inferred_obligations_snapshot);
+        result
+    }
+
+    /// Wraps a commit_if_ok s.t. obligations collected during it are not returned in selection if
+    /// the transaction fails and s.t. old obligations are retained.
+    fn commit_if_ok<T, E, F>(&mut self, f: F) -> Result<T, E> where
+        F: FnOnce(&mut Self, &infer::CombinedSnapshot) -> Result<T, E>
+    {
+        let inferred_obligations_snapshot = self.inferred_obligations.start_snapshot();
+        match self.infcx.commit_if_ok(|snapshot| f(self, snapshot)) {
+            Ok(ok) => {
+                self.inferred_obligations.commit(inferred_obligations_snapshot);
+                Ok(ok)
+            },
+            Err(err) => {
+                self.inferred_obligations.rollback_to(inferred_obligations_snapshot);
+                Err(err)
+            }
+        }
+    }
+
+
     ///////////////////////////////////////////////////////////////////////////
     // Selection
     //
@@ -359,7 +414,15 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         let stack = self.push_stack(TraitObligationStackList::empty(), obligation);
         match self.candidate_from_obligation(&stack)? {
             None => Ok(None),
-            Some(candidate) => Ok(Some(self.confirm_candidate(obligation, candidate)?)),
+            Some(candidate) => {
+                let mut candidate = self.confirm_candidate(obligation, candidate)?;
+                // FIXME(#32730) remove this assertion once inferred obligations are propagated
+                // from inference
+                assert!(self.inferred_obligations.len() == 0);
+                let inferred_obligations = (*self.inferred_obligations).into_iter().cloned();
+                candidate.nested_obligations_mut().extend(inferred_obligations);
+                Ok(Some(candidate))
+            },
         }
     }
 
@@ -381,8 +444,8 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         debug!("evaluate_obligation({:?})",
                obligation);
 
-        self.infcx.probe(|_| {
-            self.evaluate_predicate_recursively(TraitObligationStackList::empty(), obligation)
+        self.probe(|this, _| {
+            this.evaluate_predicate_recursively(TraitObligationStackList::empty(), obligation)
                 .may_apply()
         })
     }
@@ -397,8 +460,8 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         debug!("evaluate_obligation_conservatively({:?})",
                obligation);
 
-        self.infcx.probe(|_| {
-            self.evaluate_predicate_recursively(TraitObligationStackList::empty(), obligation)
+        self.probe(|this, _| {
+            this.evaluate_predicate_recursively(TraitObligationStackList::empty(), obligation)
                 == EvaluatedToOk
         })
     }
@@ -460,8 +523,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 // does this code ever run?
                 match self.infcx.equality_predicate(obligation.cause.span, p) {
                     Ok(InferOk { obligations, .. }) => {
-                        // FIXME(#32730) propagate obligations
-                        assert!(obligations.is_empty());
+                        self.inferred_obligations.extend(obligations);
                         EvaluatedToOk
                     },
                     Err(_) => EvaluatedToErr
@@ -643,11 +705,11 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
     {
         debug!("evaluate_candidate: depth={} candidate={:?}",
                stack.obligation.recursion_depth, candidate);
-        let result = self.infcx.probe(|_| {
+        let result = self.probe(|this, _| {
             let candidate = (*candidate).clone();
-            match self.confirm_candidate(stack.obligation, candidate) {
+            match this.confirm_candidate(stack.obligation, candidate) {
                 Ok(selection) => {
-                    self.evaluate_predicates_recursively(
+                    this.evaluate_predicates_recursively(
                         stack.list(),
                         selection.nested_obligations().iter())
                 }
@@ -1107,8 +1169,8 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         debug!("assemble_candidates_for_projected_tys: trait_def_id={:?}",
                trait_def_id);
 
-        let result = self.infcx.probe(|snapshot| {
-            self.match_projection_obligation_against_bounds_from_trait(obligation,
+        let result = self.probe(|this, snapshot| {
+            this.match_projection_obligation_against_bounds_from_trait(obligation,
                                                                        snapshot)
         });
 
@@ -1156,12 +1218,12 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             util::elaborate_predicates(self.tcx(), bounds.predicates.into_vec())
             .filter_to_traits()
             .find(
-                |bound| self.infcx.probe(
-                    |_| self.match_projection(obligation,
-                                              bound.clone(),
-                                              skol_trait_predicate.trait_ref.clone(),
-                                              &skol_map,
-                                              snapshot)));
+                |bound| self.probe(
+                    |this, _| this.match_projection(obligation,
+                                                    bound.clone(),
+                                                    skol_trait_predicate.trait_ref.clone(),
+                                                    &skol_map,
+                                                    snapshot)));
 
         debug!("match_projection_obligation_against_bounds_from_trait: \
                 matching_bound={:?}",
@@ -1196,8 +1258,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                                              trait_bound.clone(),
                                              ty::Binder(skol_trait_ref.clone())) {
             Ok(InferOk { obligations, .. }) => {
-                // FIXME(#32730) propagate obligations
-                assert!(obligations.is_empty());
+                self.inferred_obligations.extend(obligations);
             }
             Err(_) => { return false; }
         }
@@ -1239,10 +1300,10 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                                  where_clause_trait_ref: ty::PolyTraitRef<'tcx>)
                                  -> EvaluationResult
     {
-        self.infcx().probe(move |_| {
-            match self.match_where_clause_trait_ref(stack.obligation, where_clause_trait_ref) {
+        self.probe(move |this, _| {
+            match this.match_where_clause_trait_ref(stack.obligation, where_clause_trait_ref) {
                 Ok(obligations) => {
-                    self.evaluate_predicates_recursively(stack.list(), obligations.iter())
+                    this.evaluate_predicates_recursively(stack.list(), obligations.iter())
                 }
                 Err(()) => EvaluatedToErr
             }
@@ -1361,8 +1422,8 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             self.tcx(),
             obligation.predicate.0.trait_ref.self_ty(),
             |impl_def_id| {
-                self.infcx.probe(|snapshot| {
-                    if let Ok(_) = self.match_impl(impl_def_id, obligation, snapshot) {
+                self.probe(|this, snapshot| {
+                    if let Ok(_) = this.match_impl(impl_def_id, obligation, snapshot) {
                         candidates.vec.push(ImplCandidate(impl_def_id));
                     }
                 });
@@ -1448,12 +1509,12 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             return;
         }
 
-        self.infcx.in_snapshot(|snapshot| {
+        self.probe(|this, snapshot| {
             let (self_ty, _) =
-                self.infcx().skolemize_late_bound_regions(&obligation.self_ty(), snapshot);
+                this.infcx().skolemize_late_bound_regions(&obligation.self_ty(), snapshot);
             let poly_trait_ref = match self_ty.sty {
                 ty::TyTrait(ref data) => {
-                    match self.tcx().lang_items.to_builtin_kind(obligation.predicate.def_id()) {
+                    match this.tcx().lang_items.to_builtin_kind(obligation.predicate.def_id()) {
                         Some(bound @ ty::BoundSend) | Some(bound @ ty::BoundSync) => {
                             if data.bounds.builtin_bounds.contains(&bound) {
                                 debug!("assemble_candidates_from_object_ty: matched builtin bound, \
@@ -1465,7 +1526,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                         _ => {}
                     }
 
-                    data.principal_trait_ref_with_self_ty(self.tcx(), self_ty)
+                    data.principal_trait_ref_with_self_ty(this.tcx(), self_ty)
                 }
                 ty::TyInfer(ty::TyVar(_)) => {
                     debug!("assemble_candidates_from_object_ty: ambiguous");
@@ -1486,11 +1547,11 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             // For example, we may be trying to upcast `Foo` to `Bar<i32>`,
             // but `Foo` is declared as `trait Foo : Bar<u32>`.
             let upcast_trait_refs =
-                util::supertraits(self.tcx(), poly_trait_ref)
+                util::supertraits(this.tcx(), poly_trait_ref)
                 .filter(|upcast_trait_ref| {
-                    self.infcx.probe(|_| {
+                    this.probe(|this, _| {
                         let upcast_trait_ref = upcast_trait_ref.clone();
-                        self.match_poly_trait_ref(obligation, upcast_trait_ref).is_ok()
+                        this.match_poly_trait_ref(obligation, upcast_trait_ref).is_ok()
                     })
                 })
                 .count();
@@ -1894,23 +1955,23 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         types.skip_binder().into_iter().flat_map(|ty| { // binder moved -\
             let ty: ty::Binder<Ty<'tcx>> = ty::Binder(ty); // <----------/
 
-            self.infcx.in_snapshot(|snapshot| {
+            self.in_snapshot(|this, snapshot| {
                 let (skol_ty, skol_map) =
-                    self.infcx().skolemize_late_bound_regions(&ty, snapshot);
+                    this.infcx().skolemize_late_bound_regions(&ty, snapshot);
                 let Normalized { value: normalized_ty, mut obligations } =
-                    project::normalize_with_depth(self,
+                    project::normalize_with_depth(this,
                                                   cause.clone(),
                                                   recursion_depth,
                                                   &skol_ty);
                 let skol_obligation =
-                    self.tcx().predicate_for_trait_def(
+                    this.tcx().predicate_for_trait_def(
                                                   cause.clone(),
                                                   trait_def_id,
                                                   recursion_depth,
                                                   normalized_ty,
                                                   vec![]);
                 obligations.push(skol_obligation);
-                self.infcx().plug_leaks(skol_map, snapshot, &obligations)
+                this.infcx().plug_leaks(skol_map, snapshot, &obligations)
             })
         }).collect()
     }
@@ -1977,9 +2038,9 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             }
 
             FnPointerCandidate => {
-                let fn_type =
+                let data =
                     self.confirm_fn_pointer_candidate(obligation)?;
-                Ok(VtableFnPointer(fn_type))
+                Ok(VtableFnPointer(data))
             }
 
             ProjectionCandidate => {
@@ -1997,9 +2058,9 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
     fn confirm_projection_candidate(&mut self,
                                     obligation: &TraitObligation<'tcx>)
     {
-        self.infcx.in_snapshot(|snapshot| {
+        self.in_snapshot(|this, snapshot| {
             let result =
-                self.match_projection_obligation_against_bounds_from_trait(obligation,
+                this.match_projection_obligation_against_bounds_from_trait(obligation,
                                                                            snapshot);
             assert!(result);
         })
@@ -2140,12 +2201,12 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             trait_def_id,
             nested);
 
-        let trait_obligations = self.infcx.in_snapshot(|snapshot| {
+        let trait_obligations = self.in_snapshot(|this, snapshot| {
             let poly_trait_ref = obligation.predicate.to_poly_trait_ref();
             let (trait_ref, skol_map) =
-                self.infcx().skolemize_late_bound_regions(&poly_trait_ref, snapshot);
-            let cause = self.derived_cause(obligation, ImplDerivedObligation);
-            self.impl_or_trait_obligations(cause,
+                this.infcx().skolemize_late_bound_regions(&poly_trait_ref, snapshot);
+            let cause = this.derived_cause(obligation, ImplDerivedObligation);
+            this.impl_or_trait_obligations(cause,
                                            obligation.recursion_depth + 1,
                                            trait_def_id,
                                            &trait_ref.substs,
@@ -2174,13 +2235,13 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
         // First, create the substitutions by matching the impl again,
         // this time not in a probe.
-        self.infcx.in_snapshot(|snapshot| {
+        self.in_snapshot(|this, snapshot| {
             let (substs, skol_map) =
-                self.rematch_impl(impl_def_id, obligation,
+                this.rematch_impl(impl_def_id, obligation,
                                   snapshot);
             debug!("confirm_impl_candidate substs={:?}", substs);
-            let cause = self.derived_cause(obligation, ImplDerivedObligation);
-            self.vtable_impl(impl_def_id, substs, cause,
+            let cause = this.derived_cause(obligation, ImplDerivedObligation);
+            this.vtable_impl(impl_def_id, substs, cause,
                              obligation.recursion_depth + 1,
                              skol_map, snapshot)
         })
@@ -2227,7 +2288,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
     fn confirm_object_candidate(&mut self,
                                 obligation: &TraitObligation<'tcx>)
-                                -> VtableObjectData<'tcx>
+                                -> VtableObjectData<'tcx, PredicateObligation<'tcx>>
     {
         debug!("confirm_object_candidate({:?})",
                obligation);
@@ -2251,6 +2312,8 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         let vtable_base;
 
         {
+            let tcx = self.tcx();
+
             // We want to find the first supertrait in the list of
             // supertraits that we can unify with, and do that
             // unification. We know that there is exactly one in the list
@@ -2258,11 +2321,11 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             // reported an ambiguity. (When we do find a match, also
             // record it for later.)
             let nonmatching =
-                util::supertraits(self.tcx(), poly_trait_ref)
+                util::supertraits(tcx, poly_trait_ref)
                 .take_while(|&t| {
                     match
-                        self.infcx.commit_if_ok(
-                            |_| self.match_poly_trait_ref(obligation, t))
+                        self.commit_if_ok(
+                            |this, _| this.match_poly_trait_ref(obligation, t))
                     {
                         Ok(_) => { upcast_trait_ref = Some(t); false }
                         Err(_) => { true }
@@ -2274,7 +2337,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
             // entries, so that we can compute the offset for the selected
             // trait.
             vtable_base =
-                nonmatching.map(|t| self.tcx().count_own_vtable_entries(t))
+                nonmatching.map(|t| tcx.count_own_vtable_entries(t))
                            .sum();
 
         }
@@ -2282,12 +2345,12 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         VtableObjectData {
             upcast_trait_ref: upcast_trait_ref.unwrap(),
             vtable_base: vtable_base,
+            nested: vec![]
         }
     }
 
-    fn confirm_fn_pointer_candidate(&mut self,
-                                    obligation: &TraitObligation<'tcx>)
-                                    -> Result<ty::Ty<'tcx>,SelectionError<'tcx>>
+    fn confirm_fn_pointer_candidate(&mut self, obligation: &TraitObligation<'tcx>)
+        -> Result<VtableFnPointerData<'tcx, PredicateObligation<'tcx>>, SelectionError<'tcx>>
     {
         debug!("confirm_fn_pointer_candidate({:?})",
                obligation);
@@ -2305,7 +2368,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         self.confirm_poly_trait_refs(obligation.cause.clone(),
                                      obligation.predicate.to_poly_trait_ref(),
                                      trait_ref)?;
-        Ok(self_ty)
+        Ok(VtableFnPointerData { fn_ty: self_ty, nested: vec![] })
     }
 
     fn confirm_closure_candidate(&mut self,
@@ -2384,8 +2447,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                                        origin,
                                        expected_trait_ref.clone(),
                                        obligation_trait_ref.clone())
-            // FIXME(#32730) propagate obligations
-            .map(|InferOk { obligations, .. }| assert!(obligations.is_empty()))
+            .map(|InferOk { obligations, .. }| self.inferred_obligations.extend(obligations))
             .map_err(|e| OutputTypeParameterMismatch(expected_trait_ref, obligation_trait_ref, e))
     }
 
@@ -2420,8 +2482,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 let InferOk { obligations, .. } =
                     self.infcx.sub_types(false, origin, new_trait, target)
                     .map_err(|_| Unimplemented)?;
-                // FIXME(#32730) propagate obligations
-                assert!(obligations.is_empty());
+                self.inferred_obligations.extend(obligations);
 
                 // Register one obligation for 'a: 'b.
                 let cause = ObligationCause::new(obligation.cause.span,
@@ -2494,8 +2555,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 let InferOk { obligations, .. } =
                     self.infcx.sub_types(false, origin, a, b)
                     .map_err(|_| Unimplemented)?;
-                // FIXME(#32730) propagate obligations
-                assert!(obligations.is_empty());
+                self.inferred_obligations.extend(obligations);
             }
 
             // Struct<T> -> Struct<U>.
@@ -2554,8 +2614,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 let InferOk { obligations, .. } =
                     self.infcx.sub_types(false, origin, new_struct, target)
                     .map_err(|_| Unimplemented)?;
-                // FIXME(#32730) propagate obligations
-                assert!(obligations.is_empty());
+                self.inferred_obligations.extend(obligations);
 
                 // Construct the nested Field<T>: Unsize<Field<U>> predicate.
                 nested.push(tcx.predicate_for_trait_def(
@@ -2649,8 +2708,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 debug!("match_impl: failed eq_trait_refs due to `{}`", e);
                 ()
             })?;
-        // FIXME(#32730) propagate obligations
-        assert!(obligations.is_empty());
+        self.inferred_obligations.extend(obligations);
 
         if let Err(e) = self.infcx.leak_check(false, &skol_map, snapshot) {
             debug!("match_impl: failed leak check due to `{}`", e);
@@ -2703,7 +2761,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
     /// Returns `Ok` if `poly_trait_ref` being true implies that the
     /// obligation is satisfied.
-    fn match_poly_trait_ref(&self,
+    fn match_poly_trait_ref(&mut self,
                             obligation: &TraitObligation<'tcx>,
                             poly_trait_ref: ty::PolyTraitRef<'tcx>)
                             -> Result<(),()>
@@ -2717,8 +2775,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                                        origin,
                                        poly_trait_ref,
                                        obligation.predicate.to_poly_trait_ref())
-            // FIXME(#32730) propagate obligations
-            .map(|InferOk { obligations, .. }| assert!(obligations.is_empty()))
+            .map(|InferOk { obligations, .. }| self.inferred_obligations.extend(obligations))
             .map_err(|_| ())
     }
 
diff --git a/src/librustc/traits/structural_impls.rs b/src/librustc/traits/structural_impls.rs
index 1495ae72ab3..e210d2da94c 100644
--- a/src/librustc/traits/structural_impls.rs
+++ b/src/librustc/traits/structural_impls.rs
@@ -99,11 +99,20 @@ impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableDefaultImplData<N> {
     }
 }
 
-impl<'tcx> fmt::Debug for traits::VtableObjectData<'tcx> {
+impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableObjectData<'tcx, N> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "VtableObject(upcast={:?}, vtable_base={})",
+        write!(f, "VtableObject(upcast={:?}, vtable_base={}, nested={:?})",
                self.upcast_trait_ref,
-               self.vtable_base)
+               self.vtable_base,
+               self.nested)
+    }
+}
+
+impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableFnPointerData<'tcx, N> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "VtableFnPointer(fn_ty={:?}, nested={:?})",
+               self.fn_ty,
+               self.nested)
     }
 }
 
@@ -185,19 +194,26 @@ impl<'a, 'tcx> Lift<'tcx> for traits::Vtable<'a, ()> {
                     })
                 })
             }
-            traits::VtableFnPointer(ty) => {
-                tcx.lift(&ty).map(traits::VtableFnPointer)
+            traits::VtableFnPointer(traits::VtableFnPointerData { fn_ty, nested }) => {
+                tcx.lift(&fn_ty).map(|fn_ty| {
+                    traits::VtableFnPointer(traits::VtableFnPointerData {
+                        fn_ty: fn_ty,
+                        nested: nested,
+                    })
+                })
             }
             traits::VtableParam(n) => Some(traits::VtableParam(n)),
             traits::VtableBuiltin(d) => Some(traits::VtableBuiltin(d)),
             traits::VtableObject(traits::VtableObjectData {
                 upcast_trait_ref,
-                vtable_base
+                vtable_base,
+                nested
             }) => {
                 tcx.lift(&upcast_trait_ref).map(|trait_ref| {
                     traits::VtableObject(traits::VtableObjectData {
                         upcast_trait_ref: trait_ref,
-                        vtable_base: vtable_base
+                        vtable_base: vtable_base,
+                        nested: nested
                     })
                 })
             }
@@ -276,16 +292,30 @@ impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableBuiltinDa
     }
 }
 
-impl<'tcx> TypeFoldable<'tcx> for traits::VtableObjectData<'tcx> {
+impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableObjectData<'tcx, N> {
     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
         traits::VtableObjectData {
             upcast_trait_ref: self.upcast_trait_ref.fold_with(folder),
-            vtable_base: self.vtable_base
+            vtable_base: self.vtable_base,
+            nested: self.nested.fold_with(folder),
+        }
+    }
+
+    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
+        self.upcast_trait_ref.visit_with(visitor) || self.nested.visit_with(visitor)
+    }
+}
+
+impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableFnPointerData<'tcx, N> {
+    fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
+        traits::VtableFnPointerData {
+            fn_ty: self.fn_ty.fold_with(folder),
+            nested: self.nested.fold_with(folder),
         }
     }
 
     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
-        self.upcast_trait_ref.visit_with(visitor)
+        self.fn_ty.visit_with(visitor) || self.nested.visit_with(visitor)
     }
 }
 
diff --git a/src/librustc/traits/util.rs b/src/librustc/traits/util.rs
index 010add01237..f8149565aa6 100644
--- a/src/librustc/traits/util.rs
+++ b/src/librustc/traits/util.rs
@@ -473,9 +473,9 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     /// Given an upcast trait object described by `object`, returns the
     /// index of the method `method_def_id` (which should be part of
     /// `object.upcast_trait_ref`) within the vtable for `object`.
-    pub fn get_vtable_index_of_object_method(self,
-                                             object: &super::VtableObjectData<'tcx>,
-                                             method_def_id: DefId) -> usize {
+    pub fn get_vtable_index_of_object_method<N>(self,
+                                                object: &super::VtableObjectData<'tcx, N>,
+                                                method_def_id: DefId) -> usize {
         // Count number of methods preceding the one we are selecting and
         // add them to the total offset.
         // Skip over associated types and constants.
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 005d83da38d..114e81721ab 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -1260,7 +1260,7 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
         match tcx.map.find(id) {
             Some(ast_map::NodeImplItem(ref impl_item)) => {
                 match impl_item.node {
-                    hir::ImplItemKind::Type(_) => {
+                    hir::ImplItemKind::Type(_) | hir::ImplItemKind::Const(_, _) => {
                         // associated types don't have their own entry (for some reason),
                         // so for now just grab environment for the impl
                         let impl_id = tcx.map.get_parent(id);
@@ -1272,15 +1272,6 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                                                             &predicates,
                                                             tcx.region_maps.item_extent(id))
                     }
-                    hir::ImplItemKind::Const(_, _) => {
-                        let def_id = tcx.map.local_def_id(id);
-                        let scheme = tcx.lookup_item_type(def_id);
-                        let predicates = tcx.lookup_predicates(def_id);
-                        tcx.construct_parameter_environment(impl_item.span,
-                                                            &scheme.generics,
-                                                            &predicates,
-                                                            tcx.region_maps.item_extent(id))
-                    }
                     hir::ImplItemKind::Method(_, ref body) => {
                         let method_def_id = tcx.map.local_def_id(id);
                         match tcx.impl_or_trait_item(method_def_id) {
@@ -1303,7 +1294,7 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
             }
             Some(ast_map::NodeTraitItem(trait_item)) => {
                 match trait_item.node {
-                    hir::TypeTraitItem(..) => {
+                    hir::TypeTraitItem(..) | hir::ConstTraitItem(..) => {
                         // associated types don't have their own entry (for some reason),
                         // so for now just grab environment for the trait
                         let trait_id = tcx.map.get_parent(id);
@@ -1315,15 +1306,6 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                                                             &predicates,
                                                             tcx.region_maps.item_extent(id))
                     }
-                    hir::ConstTraitItem(..) => {
-                        let def_id = tcx.map.local_def_id(id);
-                        let scheme = tcx.lookup_item_type(def_id);
-                        let predicates = tcx.lookup_predicates(def_id);
-                        tcx.construct_parameter_environment(trait_item.span,
-                                                            &scheme.generics,
-                                                            &predicates,
-                                                            tcx.region_maps.item_extent(id))
-                    }
                     hir::MethodTraitItem(_, ref body) => {
                         // Use call-site for extent (unless this is a
                         // trait method with no default; then fallback
diff --git a/src/librustc_data_structures/snapshot_vec.rs b/src/librustc_data_structures/snapshot_vec.rs
index 614e7aae74b..dac074ab91e 100644
--- a/src/librustc_data_structures/snapshot_vec.rs
+++ b/src/librustc_data_structures/snapshot_vec.rs
@@ -213,3 +213,11 @@ impl<D: SnapshotVecDelegate> ops::IndexMut<usize> for SnapshotVec<D> {
         self.get_mut(index)
     }
 }
+
+impl<D: SnapshotVecDelegate> Extend<D::Value> for SnapshotVec<D> {
+    fn extend<T>(&mut self, iterable: T) where T: IntoIterator<Item=D::Value> {
+        for item in iterable {
+            self.push(item);
+        }
+    }
+}
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index da36cb7c2e4..46356add8c6 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -1036,7 +1036,7 @@ pub fn phase_4_translate_to_llvm<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         passes.push_pass(box mir::transform::no_landing_pads::NoLandingPads);
         passes.push_pass(box mir::transform::remove_dead_blocks::RemoveDeadBlocks);
         passes.push_pass(box mir::transform::erase_regions::EraseRegions);
-        passes.push_pass(box mir::transform::break_critical_edges::BreakCriticalEdges);
+        passes.push_pass(box mir::transform::break_cleanup_edges::BreakCleanupEdges);
         passes.run_passes(tcx, &mut mir_map);
     });
 
diff --git a/src/librustc_mir/transform/break_cleanup_edges.rs b/src/librustc_mir/transform/break_cleanup_edges.rs
new file mode 100644
index 00000000000..0eb6223a71e
--- /dev/null
+++ b/src/librustc_mir/transform/break_cleanup_edges.rs
@@ -0,0 +1,111 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use rustc::ty::TyCtxt;
+use rustc::mir::repr::*;
+use rustc::mir::transform::{MirPass, MirSource, Pass};
+
+use rustc_data_structures::bitvec::BitVector;
+
+use pretty;
+
+use traversal;
+
+pub struct BreakCleanupEdges;
+
+/**
+ * Breaks outgoing critical edges for call terminators in the MIR.
+ *
+ * Critical edges are edges that are neither the only edge leaving a
+ * block, nor the only edge entering one.
+ *
+ * When you want something to happen "along" an edge, you can either
+ * do at the end of the predecessor block, or at the start of the
+ * successor block. Critical edges have to be broken in order to prevent
+ * "edge actions" from affecting other edges. We need this for calls that are
+ * translated to LLVM invoke instructions, because invoke is a block terminator
+ * in LLVM so we can't insert any code to handle the call's result into the
+ * block that performs the call.
+ *
+ * This function will break those edges by inserting new blocks along them.
+ *
+ * NOTE: Simplify CFG will happily undo most of the work this pass does.
+ *
+ */
+
+impl<'tcx> MirPass<'tcx> for BreakCleanupEdges {
+    fn run_pass<'a>(&mut self, tcx: TyCtxt<'a, 'tcx, 'tcx>, src: MirSource, mir: &mut Mir<'tcx>) {
+        let mut pred_count = vec![0u32; mir.basic_blocks.len()];
+
+        // Build the precedecessor map for the MIR
+        for (_, data) in traversal::preorder(mir) {
+            if let Some(ref term) = data.terminator {
+                for &tgt in term.successors().iter() {
+                    pred_count[tgt.index()] += 1;
+                }
+            }
+        }
+
+        let cleanup_map : BitVector = mir.basic_blocks
+            .iter().map(|bb| bb.is_cleanup).collect();
+
+        // We need a place to store the new blocks generated
+        let mut new_blocks = Vec::new();
+
+        let bbs = mir.all_basic_blocks();
+        let cur_len = mir.basic_blocks.len();
+
+        for &bb in &bbs {
+            let data = mir.basic_block_data_mut(bb);
+
+            if let Some(ref mut term) = data.terminator {
+                if term_is_invoke(term) {
+                    let term_span = term.span;
+                    let term_scope = term.scope;
+                    let succs = term.successors_mut();
+                    for tgt in succs {
+                        let num_preds = pred_count[tgt.index()];
+                        if num_preds > 1 {
+                            // It's a critical edge, break it
+                            let goto = Terminator {
+                                span: term_span,
+                                scope: term_scope,
+                                kind: TerminatorKind::Goto { target: *tgt }
+                            };
+                            let mut data = BasicBlockData::new(Some(goto));
+                            data.is_cleanup = cleanup_map.contains(tgt.index());
+
+                            // Get the index it will be when inserted into the MIR
+                            let idx = cur_len + new_blocks.len();
+                            new_blocks.push(data);
+                            *tgt = BasicBlock::new(idx);
+                        }
+                    }
+                }
+            }
+        }
+
+        pretty::dump_mir(tcx, "break_cleanup_edges", &0, src, mir, None);
+        debug!("Broke {} N edges", new_blocks.len());
+
+        mir.basic_blocks.extend_from_slice(&new_blocks);
+    }
+}
+
+impl Pass for BreakCleanupEdges {}
+
+// Returns true if the terminator is a call that would use an invoke in LLVM.
+fn term_is_invoke(term: &Terminator) -> bool {
+    match term.kind {
+        TerminatorKind::Call { cleanup: Some(_), .. } |
+        TerminatorKind::Drop { unwind: Some(_), .. } => true,
+        _ => false
+    }
+}
diff --git a/src/librustc_mir/transform/break_critical_edges.rs b/src/librustc_mir/transform/break_critical_edges.rs
deleted file mode 100644
index a6af30b7eec..00000000000
--- a/src/librustc_mir/transform/break_critical_edges.rs
+++ /dev/null
@@ -1,117 +0,0 @@
-// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-use rustc::ty::TyCtxt;
-use rustc::mir::repr::*;
-use rustc::mir::transform::{MirPass, MirSource, Pass};
-
-use rustc_data_structures::bitvec::BitVector;
-
-use traversal;
-
-pub struct BreakCriticalEdges;
-
-/**
- * Breaks critical edges in the MIR.
- *
- * Critical edges are edges that are neither the only edge leaving a
- * block, nor the only edge entering one.
- *
- * When you want something to happen "along" an edge, you can either
- * do at the end of the predecessor block, or at the start of the
- * successor block. Critical edges have to be broken in order to prevent
- * "edge actions" from affecting other edges.
- *
- * This function will break those edges by inserting new blocks along them.
- *
- * A special case is Drop and Call terminators with unwind/cleanup successors,
- * They use `invoke` in LLVM, which terminates a block, meaning that code cannot
- * be inserted after them, so even if an edge is the only edge leaving a block
- * like that, we still insert blocks if the edge is one of many entering the
- * target.
- *
- * NOTE: Simplify CFG will happily undo most of the work this pass does.
- *
- */
-
-impl<'tcx> MirPass<'tcx> for BreakCriticalEdges {
-    fn run_pass<'a>(&mut self, _: TyCtxt<'a, 'tcx, 'tcx>,
-                    _: MirSource, mir: &mut Mir<'tcx>) {
-        break_critical_edges(mir);
-    }
-}
-
-impl Pass for BreakCriticalEdges {}
-
-fn break_critical_edges(mir: &mut Mir) {
-    let mut pred_count = vec![0u32; mir.basic_blocks.len()];
-
-    // Build the precedecessor map for the MIR
-    for (_, data) in traversal::preorder(mir) {
-        if let Some(ref term) = data.terminator {
-            for &tgt in term.successors().iter() {
-                pred_count[tgt.index()] += 1;
-            }
-        }
-    }
-
-    let cleanup_map : BitVector = mir.basic_blocks
-        .iter().map(|bb| bb.is_cleanup).collect();
-
-    // We need a place to store the new blocks generated
-    let mut new_blocks = Vec::new();
-
-    let bbs = mir.all_basic_blocks();
-    let cur_len = mir.basic_blocks.len();
-
-    for &bb in &bbs {
-        let data = mir.basic_block_data_mut(bb);
-
-        if let Some(ref mut term) = data.terminator {
-            let is_invoke = term_is_invoke(term);
-            let term_span = term.span;
-            let term_scope = term.scope;
-            let succs = term.successors_mut();
-            if succs.len() > 1 || (succs.len() > 0 && is_invoke) {
-                for tgt in succs {
-                    let num_preds = pred_count[tgt.index()];
-                    if num_preds > 1 {
-                        // It's a critical edge, break it
-                        let goto = Terminator {
-                            span: term_span,
-                            scope: term_scope,
-                            kind: TerminatorKind::Goto { target: *tgt }
-                        };
-                        let mut data = BasicBlockData::new(Some(goto));
-                        data.is_cleanup = cleanup_map.contains(tgt.index());
-
-                        // Get the index it will be when inserted into the MIR
-                        let idx = cur_len + new_blocks.len();
-                        new_blocks.push(data);
-                        *tgt = BasicBlock::new(idx);
-                    }
-                }
-            }
-        }
-    }
-
-    debug!("Broke {} N edges", new_blocks.len());
-
-    mir.basic_blocks.extend_from_slice(&new_blocks);
-}
-
-// Returns true if the terminator would use an invoke in LLVM.
-fn term_is_invoke(term: &Terminator) -> bool {
-    match term.kind {
-        TerminatorKind::Call { cleanup: Some(_), .. } |
-        TerminatorKind::Drop { unwind: Some(_), .. } => true,
-        _ => false
-    }
-}
diff --git a/src/librustc_mir/transform/mod.rs b/src/librustc_mir/transform/mod.rs
index 51f5c3cd7f5..0dcb7ef84d0 100644
--- a/src/librustc_mir/transform/mod.rs
+++ b/src/librustc_mir/transform/mod.rs
@@ -13,6 +13,6 @@ pub mod simplify_cfg;
 pub mod erase_regions;
 pub mod no_landing_pads;
 pub mod type_check;
-pub mod break_critical_edges;
+pub mod break_cleanup_edges;
 pub mod promote_consts;
 pub mod qualify_consts;
diff --git a/src/librustc_mir/transform/simplify_cfg.rs b/src/librustc_mir/transform/simplify_cfg.rs
index fa897384a54..526157a49c7 100644
--- a/src/librustc_mir/transform/simplify_cfg.rs
+++ b/src/librustc_mir/transform/simplify_cfg.rs
@@ -8,73 +8,155 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use rustc_data_structures::bitvec::BitVector;
 use rustc::middle::const_val::ConstVal;
 use rustc::ty::TyCtxt;
 use rustc::mir::repr::*;
 use rustc::mir::transform::{MirPass, MirSource, Pass};
 use pretty;
+use std::mem;
 
 use super::remove_dead_blocks::RemoveDeadBlocks;
 
+use traversal;
+
 pub struct SimplifyCfg;
 
 impl SimplifyCfg {
     pub fn new() -> SimplifyCfg {
         SimplifyCfg
     }
+}
+
+impl<'tcx> MirPass<'tcx> for SimplifyCfg {
+    fn run_pass<'a>(&mut self, tcx: TyCtxt<'a, 'tcx, 'tcx>, src: MirSource, mir: &mut Mir<'tcx>) {
+        simplify_branches(mir);
+        RemoveDeadBlocks.run_pass(tcx, src, mir);
+        merge_consecutive_blocks(mir);
+        RemoveDeadBlocks.run_pass(tcx, src, mir);
+        pretty::dump_mir(tcx, "simplify_cfg", &0, src, mir, None);
+
+        // FIXME: Should probably be moved into some kind of pass manager
+        mir.basic_blocks.shrink_to_fit();
+    }
+}
+
+impl Pass for SimplifyCfg {}
+
+fn merge_consecutive_blocks(mir: &mut Mir) {
+    // Build the precedecessor map for the MIR
+    let mut pred_count = vec![0u32; mir.basic_blocks.len()];
+    for (_, data) in traversal::preorder(mir) {
+        if let Some(ref term) = data.terminator {
+            for &tgt in term.successors().iter() {
+                pred_count[tgt.index()] += 1;
+            }
+        }
+    }
+
+    loop {
+        let mut changed = false;
+        let mut seen = BitVector::new(mir.basic_blocks.len());
+        let mut worklist = vec![START_BLOCK];
+        while let Some(bb) = worklist.pop() {
+            // Temporarily take ownership of the terminator we're modifying to keep borrowck happy
+            let mut terminator = mir.basic_block_data_mut(bb).terminator.take()
+                .expect("invalid terminator state");
+
+            // See if we can merge the target block into this one
+            loop {
+                let mut inner_change = false;
 
-    fn remove_goto_chains(&self, mir: &mut Mir) -> bool {
-        // Find the target at the end of the jump chain, return None if there is a loop
-        fn final_target(mir: &Mir, mut target: BasicBlock) -> Option<BasicBlock> {
-            // Keep track of already seen blocks to detect loops
-            let mut seen: Vec<BasicBlock> = Vec::with_capacity(8);
-
-            while mir.basic_block_data(target).statements.is_empty() {
-                // NB -- terminator may have been swapped with `None`
-                // below, in which case we have a cycle and just want
-                // to stop
-                if let Some(ref terminator) = mir.basic_block_data(target).terminator {
-                    match terminator.kind {
-                        TerminatorKind::Goto { target: next } => {
-                            if seen.contains(&next) {
-                                return None;
+                if let TerminatorKind::Goto { target } = terminator.kind {
+                    // Don't bother trying to merge a block into itself
+                    if target == bb {
+                        break;
+                    }
+
+                    let num_insts = mir.basic_block_data(target).statements.len();
+                    match mir.basic_block_data(target).terminator().kind {
+                        TerminatorKind::Goto { target: new_target } if num_insts == 0 => {
+                            inner_change = true;
+                            terminator.kind = TerminatorKind::Goto { target: new_target };
+                            pred_count[target.index()] -= 1;
+                            pred_count[new_target.index()] += 1;
+                        }
+                        _ if pred_count[target.index()] == 1 => {
+                            inner_change = true;
+                            let mut stmts = Vec::new();
+                            {
+                                let target_data = mir.basic_block_data_mut(target);
+                                mem::swap(&mut stmts, &mut target_data.statements);
+                                mem::swap(&mut terminator, target_data.terminator_mut());
                             }
-                            seen.push(next);
-                            target = next;
+
+                            mir.basic_block_data_mut(bb).statements.append(&mut stmts);
                         }
-                        _ => break
+                        _ => {}
+                    };
+                }
+
+                for target in terminator.successors_mut() {
+                    let new_target = match final_target(mir, *target) {
+                        Some(new_target) => new_target,
+                        None if mir.basic_block_data(bb).statements.is_empty() => bb,
+                        None => continue
+                    };
+                    if *target != new_target {
+                        inner_change = true;
+                        pred_count[target.index()] -= 1;
+                        pred_count[new_target.index()] += 1;
+                        *target = new_target;
                     }
-                } else {
-                    break
+                }
+
+                changed |= inner_change;
+                if !inner_change {
+                    break;
                 }
             }
 
-            Some(target)
+            mir.basic_block_data_mut(bb).terminator = Some(terminator);
+
+            for succ in mir.basic_block_data(bb).terminator().successors().iter() {
+                if seen.insert(succ.index()) {
+                    worklist.push(*succ);
+                }
+            }
         }
 
-        let mut changed = false;
-        for bb in mir.all_basic_blocks() {
-            // Temporarily take ownership of the terminator we're modifying to keep borrowck happy
-            let mut terminator = mir.basic_block_data_mut(bb).terminator.take()
-                                    .expect("invalid terminator state");
-
-            debug!("remove_goto_chains: bb={:?} terminator={:?}", bb, terminator);
-
-            for target in terminator.successors_mut() {
-                let new_target = match final_target(mir, *target) {
-                    Some(new_target) => new_target,
-                    None if mir.basic_block_data(bb).statements.is_empty() => bb,
-                    None => continue
-                };
-                changed |= *target != new_target;
-                *target = new_target;
+        if !changed {
+            break;
+        }
+    }
+}
+
+// Find the target at the end of the jump chain, return None if there is a loop
+fn final_target(mir: &Mir, mut target: BasicBlock) -> Option<BasicBlock> {
+    // Keep track of already seen blocks to detect loops
+    let mut seen: Vec<BasicBlock> = Vec::with_capacity(8);
+
+    while mir.basic_block_data(target).statements.is_empty() {
+        // NB -- terminator may have been swapped with `None` in
+        // merge_consecutive_blocks, in which case we have a cycle and just want
+        // to stop
+        match mir.basic_block_data(target).terminator {
+            Some(Terminator { kind: TerminatorKind::Goto { target: next }, .. }) =>  {
+                if seen.contains(&next) {
+                    return None;
+                }
+                seen.push(next);
+                target = next;
             }
-            mir.basic_block_data_mut(bb).terminator = Some(terminator);
+            _ => break
         }
-        changed
     }
 
-    fn simplify_branches(&self, mir: &mut Mir) -> bool {
+    Some(target)
+}
+
+fn simplify_branches(mir: &mut Mir) {
+    loop {
         let mut changed = false;
 
         for bb in mir.all_basic_blocks() {
@@ -106,25 +188,8 @@ impl SimplifyCfg {
             }
         }
 
-        changed
-    }
-}
-
-impl<'tcx> MirPass<'tcx> for SimplifyCfg {
-    fn run_pass<'a>(&mut self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                    src: MirSource, mir: &mut Mir<'tcx>) {
-        let mut counter = 0;
-        let mut changed = true;
-        while changed {
-            pretty::dump_mir(tcx, "simplify_cfg", &counter, src, mir, None);
-            counter += 1;
-            changed = self.simplify_branches(mir);
-            changed |= self.remove_goto_chains(mir);
-            RemoveDeadBlocks.run_pass(tcx, src, mir);
+        if !changed {
+            break;
         }
-        // FIXME: Should probably be moved into some kind of pass manager
-        mir.basic_blocks.shrink_to_fit();
     }
 }
-
-impl Pass for SimplifyCfg {}
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index 9cec3a51794..a1a966ea65a 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -1949,9 +1949,7 @@ impl<'a> Resolver<'a> {
                                     this.check_trait_item(impl_item.ident.name,
                                                           impl_item.span,
                                         |n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
-                                    this.with_constant_rib(|this| {
-                                        visit::walk_impl_item(this, impl_item);
-                                    });
+                                    visit::walk_impl_item(this, impl_item);
                                 }
                                 ImplItemKind::Method(ref sig, _) => {
                                     // If this is a trait impl, ensure the method
diff --git a/src/librustc_trans/base.rs b/src/librustc_trans/base.rs
index 7665b730cad..65c3aa12ba6 100644
--- a/src/librustc_trans/base.rs
+++ b/src/librustc_trans/base.rs
@@ -59,7 +59,7 @@ use callee::{Callee, CallArgs, ArgExprs, ArgVals};
 use cleanup::{self, CleanupMethods, DropHint};
 use closure;
 use common::{Block, C_bool, C_bytes_in_context, C_i32, C_int, C_uint, C_integral};
-use collector::{self, TransItem, TransItemState, TransItemCollectionMode};
+use collector::{self, TransItemState, TransItemCollectionMode};
 use common::{C_null, C_struct_in_context, C_u64, C_u8, C_undef};
 use common::{CrateContext, DropFlagHintsMap, Field, FunctionContext};
 use common::{Result, NodeIdAndSpan, VariantInfo};
@@ -80,8 +80,9 @@ use machine::{llalign_of_min, llsize_of, llsize_of_real};
 use meth;
 use mir;
 use monomorphize::{self, Instance};
-use partitioning::{self, PartitioningStrategy, InstantiationMode, CodegenUnit};
+use partitioning::{self, PartitioningStrategy, CodegenUnit};
 use symbol_names_test;
+use trans_item::TransItem;
 use tvec;
 use type_::Type;
 use type_of;
@@ -2941,8 +2942,8 @@ fn collect_and_partition_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a
         None => TransItemCollectionMode::Lazy
     };
 
-    let (items, reference_map) = time(time_passes, "translation item collection", || {
-        collector::collect_crate_translation_items(scx, collection_mode)
+    let (items, inlining_map) = time(time_passes, "translation item collection", || {
+        collector::collect_crate_translation_items(&scx, collection_mode)
     });
 
     let strategy = if scx.sess().opts.debugging_opts.incremental.is_some() {
@@ -2955,7 +2956,7 @@ fn collect_and_partition_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a
         partitioning::partition(scx.tcx(),
                                 items.iter().cloned(),
                                 strategy,
-                                &reference_map)
+                                &inlining_map)
     });
 
     if scx.sess().opts.debugging_opts.print_trans_items.is_some() {
@@ -2983,18 +2984,17 @@ fn collect_and_partition_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a
                     output.push_str(&cgu_name[..]);
 
                     let linkage_abbrev = match linkage {
-                        InstantiationMode::Def(llvm::ExternalLinkage) => "External",
-                        InstantiationMode::Def(llvm::AvailableExternallyLinkage) => "Available",
-                        InstantiationMode::Def(llvm::LinkOnceAnyLinkage) => "OnceAny",
-                        InstantiationMode::Def(llvm::LinkOnceODRLinkage) => "OnceODR",
-                        InstantiationMode::Def(llvm::WeakAnyLinkage) => "WeakAny",
-                        InstantiationMode::Def(llvm::WeakODRLinkage) => "WeakODR",
-                        InstantiationMode::Def(llvm::AppendingLinkage) => "Appending",
-                        InstantiationMode::Def(llvm::InternalLinkage) => "Internal",
-                        InstantiationMode::Def(llvm::PrivateLinkage) => "Private",
-                        InstantiationMode::Def(llvm::ExternalWeakLinkage) => "ExternalWeak",
-                        InstantiationMode::Def(llvm::CommonLinkage) => "Common",
-                        InstantiationMode::Decl => "Declaration",
+                        llvm::ExternalLinkage => "External",
+                        llvm::AvailableExternallyLinkage => "Available",
+                        llvm::LinkOnceAnyLinkage => "OnceAny",
+                        llvm::LinkOnceODRLinkage => "OnceODR",
+                        llvm::WeakAnyLinkage => "WeakAny",
+                        llvm::WeakODRLinkage => "WeakODR",
+                        llvm::AppendingLinkage => "Appending",
+                        llvm::InternalLinkage => "Internal",
+                        llvm::PrivateLinkage => "Private",
+                        llvm::ExternalWeakLinkage => "ExternalWeak",
+                        llvm::CommonLinkage => "Common",
                     };
 
                     output.push_str("[");
diff --git a/src/librustc_trans/callee.rs b/src/librustc_trans/callee.rs
index 3fb86054120..c0c5ea818b2 100644
--- a/src/librustc_trans/callee.rs
+++ b/src/librustc_trans/callee.rs
@@ -188,9 +188,9 @@ impl<'tcx> Callee<'tcx> {
                 };
                 Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty))
             }
-            traits::VtableFnPointer(fn_ty) => {
+            traits::VtableFnPointer(vtable_fn_pointer) => {
                 let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_id).unwrap();
-                let llfn = trans_fn_pointer_shim(ccx, trait_closure_kind, fn_ty);
+                let llfn = trans_fn_pointer_shim(ccx, trait_closure_kind, vtable_fn_pointer.fn_ty);
 
                 let method_ty = def_ty(tcx, def_id, substs);
                 let fn_ptr_ty = match method_ty.sty {
@@ -494,7 +494,7 @@ fn get_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
         _ => bug!("expected fn item type, found {}", ty)
     };
 
-    let instance = Instance::mono(ccx.tcx(), def_id);
+    let instance = Instance::mono(ccx.shared(), def_id);
     if let Some(&llfn) = ccx.instances().borrow().get(&instance) {
         return immediate_rvalue(llfn, fn_ptr_ty);
     }
diff --git a/src/librustc_trans/collector.rs b/src/librustc_trans/collector.rs
index dfab2bdbf64..d278c3c8320 100644
--- a/src/librustc_trans/collector.rs
+++ b/src/librustc_trans/collector.rs
@@ -188,8 +188,6 @@
 //! this is not implemented however: a translation item will be produced
 //! regardless of whether it is actually needed or not.
 
-use rustc_data_structures::bitvec::BitVector;
-
 use rustc::hir;
 use rustc::hir::intravisit as hir_visit;
 
@@ -198,27 +196,24 @@ use rustc::hir::def_id::DefId;
 use rustc::middle::lang_items::{ExchangeFreeFnLangItem, ExchangeMallocFnLangItem};
 use rustc::traits;
 use rustc::ty::subst::{self, Substs, Subst};
-use rustc::ty::{self, Ty, TypeFoldable, TyCtxt};
+use rustc::ty::{self, TypeFoldable, TyCtxt};
 use rustc::ty::adjustment::CustomCoerceUnsized;
 use rustc::mir::repr as mir;
 use rustc::mir::visit as mir_visit;
 use rustc::mir::visit::Visitor as MirVisitor;
 
-use syntax::ast::{self, NodeId};
+use syntax::abi::Abi;
 use syntax::codemap::DUMMY_SP;
-use syntax::{attr, errors};
-use syntax::parse::token;
-
-use base::{custom_coerce_unsize_info, llvm_linkage_by_name};
+use syntax::errors;
+use base::custom_coerce_unsize_info;
 use context::SharedCrateContext;
 use common::{fulfill_obligation, normalize_and_test_predicates, type_is_sized};
 use glue::{self, DropGlueKind};
-use llvm;
 use meth;
 use monomorphize::{self, Instance};
 use util::nodemap::{FnvHashSet, FnvHashMap, DefIdMap};
 
-use std::hash::{Hash, Hasher};
+use trans_item::{TransItem, type_to_string, def_id_to_string};
 
 #[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
 pub enum TransItemCollectionMode {
@@ -226,71 +221,35 @@ pub enum TransItemCollectionMode {
     Lazy
 }
 
-#[derive(PartialEq, Eq, Clone, Copy, Debug)]
-pub enum TransItem<'tcx> {
-    DropGlue(DropGlueKind<'tcx>),
-    Fn(Instance<'tcx>),
-    Static(NodeId)
-}
-
-impl<'tcx> Hash for TransItem<'tcx> {
-    fn hash<H: Hasher>(&self, s: &mut H) {
-        match *self {
-            TransItem::DropGlue(t) => {
-                0u8.hash(s);
-                t.hash(s);
-            },
-            TransItem::Fn(instance) => {
-                1u8.hash(s);
-                instance.def.hash(s);
-                (instance.substs as *const _ as usize).hash(s);
-            }
-            TransItem::Static(node_id) => {
-                2u8.hash(s);
-                node_id.hash(s);
-            }
-        };
-    }
-}
-
 /// Maps every translation item to all translation items it references in its
 /// body.
-pub struct ReferenceMap<'tcx> {
-    // Maps a source translation item to a range of target translation items.
+pub struct InliningMap<'tcx> {
+    // Maps a source translation item to a range of target translation items
+    // that are potentially inlined by LLVM into the source.
     // The two numbers in the tuple are the start (inclusive) and
-    // end index (exclusive) within the `targets` and the `inlined` vecs.
+    // end index (exclusive) within the `targets` vecs.
     index: FnvHashMap<TransItem<'tcx>, (usize, usize)>,
     targets: Vec<TransItem<'tcx>>,
-    inlined: BitVector
 }
 
-impl<'tcx> ReferenceMap<'tcx> {
+impl<'tcx> InliningMap<'tcx> {
 
-    fn new() -> ReferenceMap<'tcx> {
-        ReferenceMap {
+    fn new() -> InliningMap<'tcx> {
+        InliningMap {
             index: FnvHashMap(),
             targets: Vec::new(),
-            inlined: BitVector::new(64 * 256),
         }
     }
 
-    fn record_references<I>(&mut self, source: TransItem<'tcx>, targets: I)
-        where I: Iterator<Item=(TransItem<'tcx>, bool)>
+    fn record_inlining_canditates<I>(&mut self,
+                                     source: TransItem<'tcx>,
+                                     targets: I)
+        where I: Iterator<Item=TransItem<'tcx>>
     {
         assert!(!self.index.contains_key(&source));
 
         let start_index = self.targets.len();
-
-        for (target, inlined) in targets {
-            let index = self.targets.len();
-            self.targets.push(target);
-            self.inlined.grow(index + 1);
-
-            if inlined {
-                self.inlined.insert(index);
-            }
-        }
-
+        self.targets.extend(targets);
         let end_index = self.targets.len();
         self.index.insert(source, (start_index, end_index));
     }
@@ -301,28 +260,17 @@ impl<'tcx> ReferenceMap<'tcx> {
         where F: FnMut(TransItem<'tcx>) {
         if let Some(&(start_index, end_index)) = self.index.get(&source)
         {
-            for index in start_index .. end_index {
-                if self.inlined.contains(index) {
-                    f(self.targets[index])
-                }
+            for candidate in &self.targets[start_index .. end_index] {
+                f(*candidate)
             }
         }
     }
-
-    pub fn get_direct_references_from(&self, source: TransItem<'tcx>) -> &[TransItem<'tcx>]
-    {
-        if let Some(&(start_index, end_index)) = self.index.get(&source) {
-            &self.targets[start_index .. end_index]
-        } else {
-            &self.targets[0 .. 0]
-        }
-    }
 }
 
 pub fn collect_crate_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>,
                                                  mode: TransItemCollectionMode)
                                                  -> (FnvHashSet<TransItem<'tcx>>,
-                                                     ReferenceMap<'tcx>) {
+                                                     InliningMap<'tcx>) {
     // We are not tracking dependencies of this pass as it has to be re-executed
     // every time no matter what.
     scx.tcx().dep_graph.with_ignore(|| {
@@ -331,17 +279,17 @@ pub fn collect_crate_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a, 't
         debug!("Building translation item graph, beginning at roots");
         let mut visited = FnvHashSet();
         let mut recursion_depths = DefIdMap();
-        let mut reference_map = ReferenceMap::new();
+        let mut inlining_map = InliningMap::new();
 
         for root in roots {
             collect_items_rec(scx,
                               root,
                               &mut visited,
                               &mut recursion_depths,
-                              &mut reference_map);
+                              &mut inlining_map);
         }
 
-        (visited, reference_map)
+        (visited, inlining_map)
     })
 }
 
@@ -372,7 +320,7 @@ fn collect_items_rec<'a, 'tcx: 'a>(scx: &SharedCrateContext<'a, 'tcx>,
                                    starting_point: TransItem<'tcx>,
                                    visited: &mut FnvHashSet<TransItem<'tcx>>,
                                    recursion_depths: &mut DefIdMap<usize>,
-                                   reference_map: &mut ReferenceMap<'tcx>) {
+                                   inlining_map: &mut InliningMap<'tcx>) {
     if !visited.insert(starting_point.clone()) {
         // We've been here already, no need to search again.
         return;
@@ -392,7 +340,26 @@ fn collect_items_rec<'a, 'tcx: 'a>(scx: &SharedCrateContext<'a, 'tcx>,
             let ty = scx.tcx().lookup_item_type(def_id).ty;
             let ty = glue::get_drop_glue_type(scx.tcx(), ty);
             neighbors.push(TransItem::DropGlue(DropGlueKind::Ty(ty)));
+
             recursion_depth_reset = None;
+
+            // Scan the MIR in order to find function calls, closures, and
+            // drop-glue
+            let mir = errors::expect(scx.sess().diagnostic(), scx.get_mir(def_id),
+                || format!("Could not find MIR for static: {:?}", def_id));
+
+            let empty_substs = scx.empty_substs_for_def_id(def_id);
+            let mut visitor = MirNeighborCollector {
+                scx: scx,
+                mir: &mir,
+                output: &mut neighbors,
+                param_substs: empty_substs
+            };
+
+            visitor.visit_mir(&mir);
+            for promoted in &mir.promoted {
+                visitor.visit_mir(promoted);
+            }
         }
         TransItem::Fn(instance) => {
             // Keep track of the monomorphization recursion depth
@@ -419,10 +386,10 @@ fn collect_items_rec<'a, 'tcx: 'a>(scx: &SharedCrateContext<'a, 'tcx>,
         }
     }
 
-    record_references(scx.tcx(), starting_point, &neighbors[..], reference_map);
+    record_inlining_canditates(scx.tcx(), starting_point, &neighbors[..], inlining_map);
 
     for neighbour in neighbors {
-        collect_items_rec(scx, neighbour, visited, recursion_depths, reference_map);
+        collect_items_rec(scx, neighbour, visited, recursion_depths, inlining_map);
     }
 
     if let Some((def_id, depth)) = recursion_depth_reset {
@@ -432,17 +399,19 @@ fn collect_items_rec<'a, 'tcx: 'a>(scx: &SharedCrateContext<'a, 'tcx>,
     debug!("END collect_items_rec({})", starting_point.to_string(scx.tcx()));
 }
 
-fn record_references<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                               caller: TransItem<'tcx>,
-                               callees: &[TransItem<'tcx>],
-                               reference_map: &mut ReferenceMap<'tcx>) {
-    let iter = callees.into_iter()
-                      .map(|callee| {
-                        let is_inlining_candidate = callee.is_from_extern_crate() ||
-                                                    callee.requests_inline(tcx);
-                        (*callee, is_inlining_candidate)
-                      });
-    reference_map.record_references(caller, iter);
+fn record_inlining_canditates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                        caller: TransItem<'tcx>,
+                                        callees: &[TransItem<'tcx>],
+                                        inlining_map: &mut InliningMap<'tcx>) {
+    let is_inlining_candidate = |trans_item: &TransItem<'tcx>| {
+        trans_item.is_from_extern_crate() || trans_item.requests_inline(tcx)
+    };
+
+    let inlining_candidates = callees.into_iter()
+                                     .map(|x| *x)
+                                     .filter(is_inlining_candidate);
+
+    inlining_map.record_inlining_canditates(caller, inlining_candidates);
 }
 
 fn check_recursion_limit<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
@@ -527,10 +496,11 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                         .unwrap_or_else(|e| self.scx.sess().fatal(&e));
 
                 assert!(can_have_local_instance(self.scx.tcx(), exchange_malloc_fn_def_id));
+                let empty_substs = self.scx.empty_substs_for_def_id(exchange_malloc_fn_def_id);
                 let exchange_malloc_fn_trans_item =
                     create_fn_trans_item(self.scx.tcx(),
                                          exchange_malloc_fn_def_id,
-                                         self.scx.tcx().mk_substs(Substs::empty()),
+                                         empty_substs,
                                          self.param_substs);
 
                 self.output.push(exchange_malloc_fn_trans_item);
@@ -633,6 +603,49 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
             can_have_local_instance(tcx, def_id)
         }
     }
+
+    // This takes care of the "drop_in_place" intrinsic for which we otherwise
+    // we would not register drop-glues.
+    fn visit_terminator_kind(&mut self,
+                             block: mir::BasicBlock,
+                             kind: &mir::TerminatorKind<'tcx>) {
+        let tcx = self.scx.tcx();
+        match *kind {
+            mir::TerminatorKind::Call {
+                func: mir::Operand::Constant(ref constant),
+                ref args,
+                ..
+            } => {
+                match constant.ty.sty {
+                    ty::TyFnDef(def_id, _, bare_fn_ty)
+                        if is_drop_in_place_intrinsic(tcx, def_id, bare_fn_ty) => {
+                        let operand_ty = self.mir.operand_ty(tcx, &args[0]);
+                        if let ty::TyRawPtr(mt) = operand_ty.sty {
+                            let operand_ty = monomorphize::apply_param_substs(tcx,
+                                                                              self.param_substs,
+                                                                              &mt.ty);
+                            self.output.push(TransItem::DropGlue(DropGlueKind::Ty(operand_ty)));
+                        } else {
+                            bug!("Has the drop_in_place() intrinsic's signature changed?")
+                        }
+                    }
+                    _ => { /* Nothing to do. */ }
+                }
+            }
+            _ => { /* Nothing to do. */ }
+        }
+
+        self.super_terminator_kind(block, kind);
+
+        fn is_drop_in_place_intrinsic<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                                def_id: DefId,
+                                                bare_fn_ty: &ty::BareFnTy<'tcx>)
+                                                -> bool {
+            (bare_fn_ty.abi == Abi::RustIntrinsic ||
+             bare_fn_ty.abi == Abi::PlatformIntrinsic) &&
+            tcx.item_name(def_id).as_str() == "drop_in_place"
+        }
+    }
 }
 
 fn can_have_local_instance<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
@@ -667,10 +680,11 @@ fn find_drop_glue_neighbors<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>,
                                          .unwrap_or_else(|e| scx.sess().fatal(&e));
 
         assert!(can_have_local_instance(scx.tcx(), exchange_free_fn_def_id));
+        let fn_substs = scx.empty_substs_for_def_id(exchange_free_fn_def_id);
         let exchange_free_fn_trans_item =
             create_fn_trans_item(scx.tcx(),
                                  exchange_free_fn_def_id,
-                                 scx.tcx().mk_substs(Substs::empty()),
+                                 fn_substs,
                                  scx.tcx().mk_substs(Substs::empty()));
 
         output.push(exchange_free_fn_trans_item);
@@ -730,7 +744,6 @@ fn find_drop_glue_neighbors<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>,
         ty::TyRef(..)   |
         ty::TyFnDef(..) |
         ty::TyFnPtr(_)  |
-        ty::TySlice(_)  |
         ty::TyTrait(_)  => {
             /* nothing to do */
         }
@@ -756,6 +769,7 @@ fn find_drop_glue_neighbors<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>,
             }
         }
         ty::TyBox(inner_type)      |
+        ty::TySlice(inner_type)    |
         ty::TyArray(inner_type, _) => {
             let inner_type = glue::get_drop_glue_type(scx.tcx(), inner_type);
             if glue::type_needs_drop(scx.tcx(), inner_type) {
@@ -777,6 +791,8 @@ fn find_drop_glue_neighbors<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>,
             bug!("encountered unexpected type");
         }
     }
+
+
 }
 
 fn do_static_dispatch<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>,
@@ -1097,7 +1113,7 @@ impl<'b, 'a, 'v> hir_visit::Visitor<'v> for RootCollector<'b, 'a, 'v> {
                     debug!("RootCollector: ItemFn({})",
                            def_id_to_string(self.scx.tcx(), def_id));
 
-                    let instance = Instance::mono(self.scx.tcx(), def_id);
+                    let instance = Instance::mono(self.scx, def_id);
                     self.output.push(TransItem::Fn(instance));
                 }
             }
@@ -1134,7 +1150,7 @@ impl<'b, 'a, 'v> hir_visit::Visitor<'v> for RootCollector<'b, 'a, 'v> {
                     debug!("RootCollector: MethodImplItem({})",
                            def_id_to_string(self.scx.tcx(), def_id));
 
-                    let instance = Instance::mono(self.scx.tcx(), def_id);
+                    let instance = Instance::mono(self.scx, def_id);
                     self.output.push(TransItem::Fn(instance));
                 }
             }
@@ -1210,334 +1226,6 @@ fn create_trans_items_for_default_impls<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     }
 }
 
-//=-----------------------------------------------------------------------------
-// TransItem String Keys
-//=-----------------------------------------------------------------------------
-
-// The code below allows for producing a unique string key for a trans item.
-// These keys are used by the handwritten auto-tests, so they need to be
-// predictable and human-readable.
-//
-// Note: A lot of this could looks very similar to what's already in the
-//       ppaux module. It would be good to refactor things so we only have one
-//       parameterizable implementation for printing types.
-
-/// Same as `unique_type_name()` but with the result pushed onto the given
-/// `output` parameter.
-pub fn push_unique_type_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                                       t: ty::Ty<'tcx>,
-                                       output: &mut String) {
-    match t.sty {
-        ty::TyBool              => output.push_str("bool"),
-        ty::TyChar              => output.push_str("char"),
-        ty::TyStr               => output.push_str("str"),
-        ty::TyInt(ast::IntTy::Is)    => output.push_str("isize"),
-        ty::TyInt(ast::IntTy::I8)    => output.push_str("i8"),
-        ty::TyInt(ast::IntTy::I16)   => output.push_str("i16"),
-        ty::TyInt(ast::IntTy::I32)   => output.push_str("i32"),
-        ty::TyInt(ast::IntTy::I64)   => output.push_str("i64"),
-        ty::TyUint(ast::UintTy::Us)   => output.push_str("usize"),
-        ty::TyUint(ast::UintTy::U8)   => output.push_str("u8"),
-        ty::TyUint(ast::UintTy::U16)  => output.push_str("u16"),
-        ty::TyUint(ast::UintTy::U32)  => output.push_str("u32"),
-        ty::TyUint(ast::UintTy::U64)  => output.push_str("u64"),
-        ty::TyFloat(ast::FloatTy::F32) => output.push_str("f32"),
-        ty::TyFloat(ast::FloatTy::F64) => output.push_str("f64"),
-        ty::TyStruct(adt_def, substs) |
-        ty::TyEnum(adt_def, substs) => {
-            push_item_name(tcx, adt_def.did, output);
-            push_type_params(tcx, &substs.types, &[], output);
-        },
-        ty::TyTuple(component_types) => {
-            output.push('(');
-            for &component_type in component_types {
-                push_unique_type_name(tcx, component_type, output);
-                output.push_str(", ");
-            }
-            if !component_types.is_empty() {
-                output.pop();
-                output.pop();
-            }
-            output.push(')');
-        },
-        ty::TyBox(inner_type) => {
-            output.push_str("Box<");
-            push_unique_type_name(tcx, inner_type, output);
-            output.push('>');
-        },
-        ty::TyRawPtr(ty::TypeAndMut { ty: inner_type, mutbl } ) => {
-            output.push('*');
-            match mutbl {
-                hir::MutImmutable => output.push_str("const "),
-                hir::MutMutable => output.push_str("mut "),
-            }
-
-            push_unique_type_name(tcx, inner_type, output);
-        },
-        ty::TyRef(_, ty::TypeAndMut { ty: inner_type, mutbl }) => {
-            output.push('&');
-            if mutbl == hir::MutMutable {
-                output.push_str("mut ");
-            }
-
-            push_unique_type_name(tcx, inner_type, output);
-        },
-        ty::TyArray(inner_type, len) => {
-            output.push('[');
-            push_unique_type_name(tcx, inner_type, output);
-            output.push_str(&format!("; {}", len));
-            output.push(']');
-        },
-        ty::TySlice(inner_type) => {
-            output.push('[');
-            push_unique_type_name(tcx, inner_type, output);
-            output.push(']');
-        },
-        ty::TyTrait(ref trait_data) => {
-            push_item_name(tcx, trait_data.principal.skip_binder().def_id, output);
-            push_type_params(tcx,
-                             &trait_data.principal.skip_binder().substs.types,
-                             &trait_data.bounds.projection_bounds,
-                             output);
-        },
-        ty::TyFnDef(_, _, &ty::BareFnTy{ unsafety, abi, ref sig } ) |
-        ty::TyFnPtr(&ty::BareFnTy{ unsafety, abi, ref sig } ) => {
-            if unsafety == hir::Unsafety::Unsafe {
-                output.push_str("unsafe ");
-            }
-
-            if abi != ::abi::Abi::Rust {
-                output.push_str("extern \"");
-                output.push_str(abi.name());
-                output.push_str("\" ");
-            }
-
-            output.push_str("fn(");
-
-            let sig = tcx.erase_late_bound_regions(sig);
-            if !sig.inputs.is_empty() {
-                for &parameter_type in &sig.inputs {
-                    push_unique_type_name(tcx, parameter_type, output);
-                    output.push_str(", ");
-                }
-                output.pop();
-                output.pop();
-            }
-
-            if sig.variadic {
-                if !sig.inputs.is_empty() {
-                    output.push_str(", ...");
-                } else {
-                    output.push_str("...");
-                }
-            }
-
-            output.push(')');
-
-            match sig.output {
-                ty::FnConverging(result_type) if result_type.is_nil() => {}
-                ty::FnConverging(result_type) => {
-                    output.push_str(" -> ");
-                    push_unique_type_name(tcx, result_type, output);
-                }
-                ty::FnDiverging => {
-                    output.push_str(" -> !");
-                }
-            }
-        },
-        ty::TyClosure(def_id, ref closure_substs) => {
-            push_item_name(tcx, def_id, output);
-            output.push_str("{");
-            output.push_str(&format!("{}:{}", def_id.krate, def_id.index.as_usize()));
-            output.push_str("}");
-            push_type_params(tcx, &closure_substs.func_substs.types, &[], output);
-        }
-        ty::TyError |
-        ty::TyInfer(_) |
-        ty::TyProjection(..) |
-        ty::TyParam(_) => {
-            bug!("debuginfo: Trying to create type name for \
-                  unexpected type: {:?}", t);
-        }
-    }
-}
-
-fn push_item_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                            def_id: DefId,
-                            output: &mut String) {
-    let def_path = tcx.def_path(def_id);
-
-    // some_crate::
-    output.push_str(&tcx.crate_name(def_path.krate));
-    output.push_str("::");
-
-    // foo::bar::ItemName::
-    for part in tcx.def_path(def_id).data {
-        output.push_str(&format!("{}[{}]::",
-                        part.data.as_interned_str(),
-                        part.disambiguator));
-    }
-
-    // remove final "::"
-    output.pop();
-    output.pop();
-}
-
-fn push_type_params<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                              types: &'tcx subst::VecPerParamSpace<Ty<'tcx>>,
-                              projections: &[ty::PolyProjectionPredicate<'tcx>],
-                              output: &mut String) {
-    if types.is_empty() && projections.is_empty() {
-        return;
-    }
-
-    output.push('<');
-
-    for &type_parameter in types {
-        push_unique_type_name(tcx, type_parameter, output);
-        output.push_str(", ");
-    }
-
-    for projection in projections {
-        let projection = projection.skip_binder();
-        let name = token::get_ident_interner().get(projection.projection_ty.item_name);
-        output.push_str(&name[..]);
-        output.push_str("=");
-        push_unique_type_name(tcx, projection.ty, output);
-        output.push_str(", ");
-    }
-
-    output.pop();
-    output.pop();
-
-    output.push('>');
-}
-
-fn push_instance_as_string<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                                     instance: Instance<'tcx>,
-                                     output: &mut String) {
-    push_item_name(tcx, instance.def, output);
-    push_type_params(tcx, &instance.substs.types, &[], output);
-}
-
-pub fn def_id_to_string<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                                  def_id: DefId) -> String {
-    let mut output = String::new();
-    push_item_name(tcx, def_id, &mut output);
-    output
-}
-
-fn type_to_string<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                            ty: ty::Ty<'tcx>)
-                            -> String {
-    let mut output = String::new();
-    push_unique_type_name(tcx, ty, &mut output);
-    output
-}
-
-impl<'a, 'tcx> TransItem<'tcx> {
-    pub fn requests_inline(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> bool {
-        match *self {
-            TransItem::Fn(ref instance) => {
-                let attributes = tcx.get_attrs(instance.def);
-                attr::requests_inline(&attributes[..])
-            }
-            TransItem::DropGlue(..) => true,
-            TransItem::Static(..)   => false,
-        }
-    }
-
-    pub fn is_from_extern_crate(&self) -> bool {
-        match *self {
-            TransItem::Fn(ref instance) => !instance.def.is_local(),
-            TransItem::DropGlue(..) |
-            TransItem::Static(..)   => false,
-        }
-    }
-
-    pub fn is_lazily_instantiated(&self) -> bool {
-        match *self {
-            TransItem::Fn(ref instance) => !instance.substs.types.is_empty(),
-            TransItem::DropGlue(..) => true,
-            TransItem::Static(..)   => false,
-        }
-    }
-
-    pub fn explicit_linkage(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Option<llvm::Linkage> {
-        let def_id = match *self {
-            TransItem::Fn(ref instance) => instance.def,
-            TransItem::Static(node_id) => tcx.map.local_def_id(node_id),
-            TransItem::DropGlue(..) => return None,
-        };
-
-        let attributes = tcx.get_attrs(def_id);
-        if let Some(name) = attr::first_attr_value_str_by_name(&attributes, "linkage") {
-            if let Some(linkage) = llvm_linkage_by_name(&name) {
-                Some(linkage)
-            } else {
-                let span = tcx.map.span_if_local(def_id);
-                if let Some(span) = span {
-                    tcx.sess.span_fatal(span, "invalid linkage specified")
-                } else {
-                    tcx.sess.fatal(&format!("invalid linkage specified: {}", name))
-                }
-            }
-        } else {
-            None
-        }
-    }
-
-    pub fn to_string(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> String {
-        let hir_map = &tcx.map;
-
-        return match *self {
-            TransItem::DropGlue(dg) => {
-                let mut s = String::with_capacity(32);
-                match dg {
-                    DropGlueKind::Ty(_) => s.push_str("drop-glue "),
-                    DropGlueKind::TyContents(_) => s.push_str("drop-glue-contents "),
-                };
-                push_unique_type_name(tcx, dg.ty(), &mut s);
-                s
-            }
-            TransItem::Fn(instance) => {
-                to_string_internal(tcx, "fn ", instance)
-            },
-            TransItem::Static(node_id) => {
-                let def_id = hir_map.local_def_id(node_id);
-                let instance = Instance::mono(tcx, def_id);
-                to_string_internal(tcx, "static ", instance)
-            },
-        };
-
-        fn to_string_internal<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                                        prefix: &str,
-                                        instance: Instance<'tcx>)
-                                        -> String {
-            let mut result = String::with_capacity(32);
-            result.push_str(prefix);
-            push_instance_as_string(tcx, instance, &mut result);
-            result
-        }
-    }
-
-    fn to_raw_string(&self) -> String {
-        match *self {
-            TransItem::DropGlue(dg) => {
-                format!("DropGlue({})", dg.ty() as *const _ as usize)
-            }
-            TransItem::Fn(instance) => {
-                format!("Fn({:?}, {})",
-                         instance.def,
-                         instance.substs as *const _ as usize)
-            }
-            TransItem::Static(id) => {
-                format!("Static({:?})", id)
-            }
-        }
-    }
-}
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum TransItemState {
     PredictedAndGenerated,
@@ -1546,7 +1234,7 @@ pub enum TransItemState {
 }
 
 pub fn collecting_debug_information(scx: &SharedCrateContext) -> bool {
-    return cfg!(debug_assertions) &&
+    return scx.sess().opts.cg.debug_assertions == Some(true) &&
            scx.sess().opts.debugging_opts.print_trans_items.is_some();
 }
 
diff --git a/src/librustc_trans/consts.rs b/src/librustc_trans/consts.rs
index 7775ed3fc68..3e876eb3d7d 100644
--- a/src/librustc_trans/consts.rs
+++ b/src/librustc_trans/consts.rs
@@ -21,7 +21,8 @@ use rustc::hir::map as hir_map;
 use {abi, adt, closure, debuginfo, expr, machine};
 use base::{self, exported_name, imported_name, push_ctxt};
 use callee::Callee;
-use collector::{self, TransItem};
+use collector;
+use trans_item::TransItem;
 use common::{type_is_sized, C_nil, const_get_elt};
 use common::{CrateContext, C_integral, C_floating, C_bool, C_str_slice, C_bytes, val_ty};
 use common::{C_struct, C_undef, const_to_opt_int, const_to_opt_uint, VariantInfo, C_uint};
@@ -1011,7 +1012,7 @@ pub fn get_static<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, def_id: DefId)
                             -> Datum<'tcx, Lvalue> {
     let ty = ccx.tcx().lookup_item_type(def_id).ty;
 
-    let instance = Instance::mono(ccx.tcx(), def_id);
+    let instance = Instance::mono(ccx.shared(), def_id);
     if let Some(&g) = ccx.instances().borrow().get(&instance) {
         return Datum::new(g, ty, Lvalue::new("static"));
     }
diff --git a/src/librustc_trans/context.rs b/src/librustc_trans/context.rs
index 61137d7f377..60c6af84ebb 100644
--- a/src/librustc_trans/context.rs
+++ b/src/librustc_trans/context.rs
@@ -27,8 +27,9 @@ use glue::DropGlueKind;
 use mir::CachedMir;
 use monomorphize::Instance;
 
-use collector::{TransItem, TransItemState};
 use partitioning::CodegenUnit;
+use collector::TransItemState;
+use trans_item::TransItem;
 use type_::{Type, TypeNames};
 use rustc::ty::subst::{Substs, VecPerParamSpace};
 use rustc::ty::{self, Ty, TyCtxt};
@@ -487,6 +488,21 @@ impl<'b, 'tcx> SharedCrateContext<'b, 'tcx> {
     pub fn translation_items(&self) -> &RefCell<FnvHashMap<TransItem<'tcx>, TransItemState>> {
         &self.translation_items
     }
+
+    /// Given the def-id of some item that has no type parameters, make
+    /// a suitable "empty substs" for it.
+    pub fn empty_substs_for_def_id(&self, item_def_id: DefId) -> &'tcx Substs<'tcx> {
+        let scheme = self.tcx().lookup_item_type(item_def_id);
+        self.empty_substs_for_scheme(&scheme)
+    }
+
+    pub fn empty_substs_for_scheme(&self, scheme: &ty::TypeScheme<'tcx>)
+                                   -> &'tcx Substs<'tcx> {
+        assert!(scheme.generics.types.is_empty());
+        self.tcx().mk_substs(
+            Substs::new(VecPerParamSpace::empty(),
+                        scheme.generics.regions.map(|_| ty::ReStatic)))
+    }
 }
 
 impl<'tcx> LocalCrateContext<'tcx> {
@@ -901,16 +917,12 @@ impl<'b, 'tcx> CrateContext<'b, 'tcx> {
     /// Given the def-id of some item that has no type parameters, make
     /// a suitable "empty substs" for it.
     pub fn empty_substs_for_def_id(&self, item_def_id: DefId) -> &'tcx Substs<'tcx> {
-        let scheme = self.tcx().lookup_item_type(item_def_id);
-        self.empty_substs_for_scheme(&scheme)
+        self.shared().empty_substs_for_def_id(item_def_id)
     }
 
     pub fn empty_substs_for_scheme(&self, scheme: &ty::TypeScheme<'tcx>)
                                    -> &'tcx Substs<'tcx> {
-        assert!(scheme.generics.types.is_empty());
-        self.tcx().mk_substs(
-            Substs::new(VecPerParamSpace::empty(),
-                        scheme.generics.regions.map(|_| ty::ReStatic)))
+        self.shared().empty_substs_for_scheme(scheme)
     }
 }
 
diff --git a/src/librustc_trans/glue.rs b/src/librustc_trans/glue.rs
index a29ff95851d..10e33195305 100644
--- a/src/librustc_trans/glue.rs
+++ b/src/librustc_trans/glue.rs
@@ -29,13 +29,14 @@ use build::*;
 use callee::{Callee, ArgVals};
 use cleanup;
 use cleanup::CleanupMethods;
-use collector::{self, TransItem};
+use collector;
 use common::*;
 use debuginfo::DebugLoc;
 use declare;
 use expr;
 use machine::*;
 use monomorphize;
+use trans_item::TransItem;
 use type_of::{type_of, sizing_type_of, align_of};
 use type_::Type;
 use value::Value;
diff --git a/src/librustc_trans/lib.rs b/src/librustc_trans/lib.rs
index f48409ec755..bccb5aa050b 100644
--- a/src/librustc_trans/lib.rs
+++ b/src/librustc_trans/lib.rs
@@ -123,6 +123,7 @@ mod mir;
 mod monomorphize;
 mod partitioning;
 mod symbol_names_test;
+mod trans_item;
 mod tvec;
 mod type_;
 mod type_of;
diff --git a/src/librustc_trans/meth.rs b/src/librustc_trans/meth.rs
index 9b279a397f8..64ee18fccef 100644
--- a/src/librustc_trans/meth.rs
+++ b/src/librustc_trans/meth.rs
@@ -176,7 +176,10 @@ pub fn get_vtable<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                                          trait_closure_kind);
                 vec![llfn].into_iter()
             }
-            traits::VtableFnPointer(bare_fn_ty) => {
+            traits::VtableFnPointer(
+                traits::VtableFnPointerData {
+                    fn_ty: bare_fn_ty,
+                    nested: _ }) => {
                 let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_ref.def_id()).unwrap();
                 vec![trans_fn_pointer_shim(ccx, trait_closure_kind, bare_fn_ty)].into_iter()
             }
diff --git a/src/librustc_trans/mir/block.rs b/src/librustc_trans/mir/block.rs
index e1318396e31..4e3386bc736 100644
--- a/src/librustc_trans/mir/block.rs
+++ b/src/librustc_trans/mir/block.rs
@@ -24,6 +24,7 @@ use meth;
 use type_of;
 use glue;
 use type_::Type;
+use rustc_data_structures::fnv::FnvHashMap;
 
 use super::{MirContext, TempRef, drop};
 use super::constant::Const;
@@ -95,17 +96,32 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
                     adt::trans_get_discr(bcx, &repr, discr_lvalue.llval, None, true)
                 );
 
-                // The else branch of the Switch can't be hit, so branch to an unreachable
-                // instruction so LLVM knows that
-                let unreachable_blk = self.unreachable_block();
-                let switch = bcx.switch(discr, unreachable_blk.llbb, targets.len());
+                let mut bb_hist = FnvHashMap();
+                for target in targets {
+                    *bb_hist.entry(target).or_insert(0) += 1;
+                }
+                let (default_bb, default_blk) = match bb_hist.iter().max_by_key(|&(_, c)| c) {
+                    // If a single target basic blocks is predominant, promote that to be the
+                    // default case for the switch instruction to reduce the size of the generated
+                    // code. This is especially helpful in cases like an if-let on a huge enum.
+                    // Note: This optimization is only valid for exhaustive matches.
+                    Some((&&bb, &c)) if c > targets.len() / 2 => {
+                        (Some(bb), self.blocks[bb.index()])
+                    }
+                    // We're generating an exhaustive switch, so the else branch
+                    // can't be hit.  Branching to an unreachable instruction
+                    // lets LLVM know this
+                    _ => (None, self.unreachable_block())
+                };
+                let switch = bcx.switch(discr, default_blk.llbb, targets.len());
                 assert_eq!(adt_def.variants.len(), targets.len());
-                for (adt_variant, target) in adt_def.variants.iter().zip(targets) {
-                    let llval = bcx.with_block(|bcx|
-                        adt::trans_case(bcx, &repr, Disr::from(adt_variant.disr_val))
-                    );
-                    let llbb = self.llblock(*target);
-                    build::AddCase(switch, llval, llbb)
+                for (adt_variant, &target) in adt_def.variants.iter().zip(targets) {
+                    if default_bb != Some(target) {
+                        let llbb = self.llblock(target);
+                        let llval = bcx.with_block(|bcx| adt::trans_case(
+                                bcx, &repr, Disr::from(adt_variant.disr_val)));
+                        build::AddCase(switch, llval, llbb)
+                    }
                 }
             }
 
diff --git a/src/librustc_trans/mir/constant.rs b/src/librustc_trans/mir/constant.rs
index 039304ece60..0403c7b1f75 100644
--- a/src/librustc_trans/mir/constant.rs
+++ b/src/librustc_trans/mir/constant.rs
@@ -854,6 +854,6 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
 
 pub fn trans_static_initializer(ccx: &CrateContext, def_id: DefId)
                                 -> Result<ValueRef, ConstEvalFailure> {
-    let instance = Instance::mono(ccx.tcx(), def_id);
+    let instance = Instance::mono(ccx.shared(), def_id);
     MirConstContext::trans_def(ccx, instance, vec![]).map(|c| c.llval)
 }
diff --git a/src/librustc_trans/monomorphize.rs b/src/librustc_trans/monomorphize.rs
index 8b1809e4023..dfaf84ecef0 100644
--- a/src/librustc_trans/monomorphize.rs
+++ b/src/librustc_trans/monomorphize.rs
@@ -183,8 +183,8 @@ impl<'tcx> Instance<'tcx> {
         assert!(substs.regions.iter().all(|&r| r == ty::ReStatic));
         Instance { def: def_id, substs: substs }
     }
-    pub fn mono<'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Instance<'tcx> {
-        Instance::new(def_id, tcx.mk_substs(Substs::empty()))
+    pub fn mono<'a>(scx: &SharedCrateContext<'a, 'tcx>, def_id: DefId) -> Instance<'tcx> {
+        Instance::new(def_id, scx.empty_substs_for_def_id(def_id))
     }
 }
 
diff --git a/src/librustc_trans/partitioning.rs b/src/librustc_trans/partitioning.rs
index 18a860f9357..098ba759247 100644
--- a/src/librustc_trans/partitioning.rs
+++ b/src/librustc_trans/partitioning.rs
@@ -116,30 +116,20 @@
 //! source-level module, functions from the same module will be available for
 //! inlining, even when they are not marked #[inline].
 
-use collector::{TransItem, ReferenceMap};
+use collector::InliningMap;
+use llvm;
 use monomorphize;
 use rustc::hir::def_id::DefId;
 use rustc::hir::map::DefPathData;
 use rustc::ty::TyCtxt;
 use rustc::ty::item_path::characteristic_def_id_of_type;
-use llvm;
 use syntax::parse::token::{self, InternedString};
+use trans_item::TransItem;
 use util::nodemap::{FnvHashMap, FnvHashSet};
 
-#[derive(Clone, Copy, Eq, PartialEq, Debug)]
-pub enum InstantiationMode {
-    /// This variant indicates that a translation item should be placed in some
-    /// codegen unit as a definition and with the given linkage.
-    Def(llvm::Linkage),
-
-    /// This variant indicates that only a declaration of some translation item
-    /// should be placed in a given codegen unit.
-    Decl
-}
-
 pub struct CodegenUnit<'tcx> {
     pub name: InternedString,
-    pub items: FnvHashMap<TransItem<'tcx>, InstantiationMode>,
+    pub items: FnvHashMap<TransItem<'tcx>, llvm::Linkage>,
 }
 
 pub enum PartitioningStrategy {
@@ -156,7 +146,7 @@ const FALLBACK_CODEGEN_UNIT: &'static str = "__rustc_fallback_codegen_unit";
 pub fn partition<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                               trans_items: I,
                               strategy: PartitioningStrategy,
-                              reference_map: &ReferenceMap<'tcx>)
+                              inlining_map: &InliningMap<'tcx>)
                               -> Vec<CodegenUnit<'tcx>>
     where I: Iterator<Item = TransItem<'tcx>>
 {
@@ -176,13 +166,8 @@ pub fn partition<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     // translation items can be drop-glue, functions from external crates, and
     // local functions the definition of which is marked with #[inline].
     let post_inlining = place_inlined_translation_items(initial_partitioning,
-                                                        reference_map);
-
-    // Now we know all *definitions* within all codegen units, thus we can
-    // easily determine which declarations need to be placed within each one.
-    let post_declarations = place_declarations(post_inlining, reference_map);
-
-    post_declarations.0
+                                                        inlining_map);
+    post_inlining.0
 }
 
 struct PreInliningPartitioning<'tcx> {
@@ -191,7 +176,6 @@ struct PreInliningPartitioning<'tcx> {
 }
 
 struct PostInliningPartitioning<'tcx>(Vec<CodegenUnit<'tcx>>);
-struct PostDeclarationsPartitioning<'tcx>(Vec<CodegenUnit<'tcx>>);
 
 fn place_root_translation_items<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                              trans_items: I)
@@ -239,8 +223,7 @@ fn place_root_translation_items<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                 }
             };
 
-            codegen_unit.items.insert(trans_item,
-                                      InstantiationMode::Def(linkage));
+            codegen_unit.items.insert(trans_item, linkage);
             roots.insert(trans_item);
         }
     }
@@ -294,7 +277,7 @@ fn merge_codegen_units<'tcx>(initial_partitioning: &mut PreInliningPartitioning<
 }
 
 fn place_inlined_translation_items<'tcx>(initial_partitioning: PreInliningPartitioning<'tcx>,
-                                         reference_map: &ReferenceMap<'tcx>)
+                                         inlining_map: &InliningMap<'tcx>)
                                          -> PostInliningPartitioning<'tcx> {
     let mut new_partitioning = Vec::new();
 
@@ -302,7 +285,7 @@ fn place_inlined_translation_items<'tcx>(initial_partitioning: PreInliningPartit
         // Collect all items that need to be available in this codegen unit
         let mut reachable = FnvHashSet();
         for root in codegen_unit.items.keys() {
-            follow_inlining(*root, reference_map, &mut reachable);
+            follow_inlining(*root, inlining_map, &mut reachable);
         }
 
         let mut new_codegen_unit = CodegenUnit {
@@ -312,22 +295,22 @@ fn place_inlined_translation_items<'tcx>(initial_partitioning: PreInliningPartit
 
         // Add all translation items that are not already there
         for trans_item in reachable {
-            if let Some(instantiation_mode) = codegen_unit.items.get(&trans_item) {
+            if let Some(linkage) = codegen_unit.items.get(&trans_item) {
                 // This is a root, just copy it over
-                new_codegen_unit.items.insert(trans_item, *instantiation_mode);
+                new_codegen_unit.items.insert(trans_item, *linkage);
             } else {
                 if initial_partitioning.roots.contains(&trans_item) {
                     // This item will be instantiated in some other codegen unit,
                     // so we just add it here with AvailableExternallyLinkage
                     new_codegen_unit.items.insert(trans_item,
-                        InstantiationMode::Def(llvm::AvailableExternallyLinkage));
+                                                  llvm::AvailableExternallyLinkage);
                 } else {
                     // We can't be sure if this will also be instantiated
                     // somewhere else, so we add an instance here with
                     // LinkOnceODRLinkage. That way the item can be discarded if
                     // it's not needed (inlined) after all.
                     new_codegen_unit.items.insert(trans_item,
-                        InstantiationMode::Def(llvm::LinkOnceODRLinkage));
+                                                  llvm::LinkOnceODRLinkage);
                 }
             }
         }
@@ -338,43 +321,18 @@ fn place_inlined_translation_items<'tcx>(initial_partitioning: PreInliningPartit
     return PostInliningPartitioning(new_partitioning);
 
     fn follow_inlining<'tcx>(trans_item: TransItem<'tcx>,
-                             reference_map: &ReferenceMap<'tcx>,
+                             inlining_map: &InliningMap<'tcx>,
                              visited: &mut FnvHashSet<TransItem<'tcx>>) {
         if !visited.insert(trans_item) {
             return;
         }
 
-        reference_map.with_inlining_candidates(trans_item, |target| {
-            follow_inlining(target, reference_map, visited);
+        inlining_map.with_inlining_candidates(trans_item, |target| {
+            follow_inlining(target, inlining_map, visited);
         });
     }
 }
 
-fn place_declarations<'tcx>(codegen_units: PostInliningPartitioning<'tcx>,
-                            reference_map: &ReferenceMap<'tcx>)
-                            -> PostDeclarationsPartitioning<'tcx> {
-    let PostInliningPartitioning(mut codegen_units) = codegen_units;
-
-    for codegen_unit in codegen_units.iter_mut() {
-        let mut declarations = FnvHashSet();
-
-        for (trans_item, _) in &codegen_unit.items {
-            for referenced_item in reference_map.get_direct_references_from(*trans_item) {
-                if !codegen_unit.items.contains_key(referenced_item) {
-                    declarations.insert(*referenced_item);
-                }
-            }
-        }
-
-        codegen_unit.items
-                    .extend(declarations.iter()
-                                        .map(|trans_item| (*trans_item,
-                                                           InstantiationMode::Decl)));
-    }
-
-    PostDeclarationsPartitioning(codegen_units)
-}
-
 fn characteristic_def_id_of_trans_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                                  trans_item: TransItem<'tcx>)
                                                  -> Option<DefId> {
diff --git a/src/librustc_trans/symbol_names_test.rs b/src/librustc_trans/symbol_names_test.rs
index 2e3355968df..284a227276d 100644
--- a/src/librustc_trans/symbol_names_test.rs
+++ b/src/librustc_trans/symbol_names_test.rs
@@ -52,7 +52,7 @@ impl<'a, 'tcx> SymbolNamesTest<'a, 'tcx> {
         for attr in tcx.get_attrs(def_id).iter() {
             if attr.check_name(SYMBOL_NAME) {
                 // for now, can only use on monomorphic names
-                let instance = Instance::mono(tcx, def_id);
+                let instance = Instance::mono(self.ccx.shared(), def_id);
                 let name = symbol_names::exported_name(self.ccx, &instance);
                 tcx.sess.span_err(attr.span, &format!("symbol-name({})", name));
             } else if attr.check_name(ITEM_PATH) {
diff --git a/src/librustc_trans/trans_item.rs b/src/librustc_trans/trans_item.rs
new file mode 100644
index 00000000000..d7c5c41a156
--- /dev/null
+++ b/src/librustc_trans/trans_item.rs
@@ -0,0 +1,384 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Walks the crate looking for items/impl-items/trait-items that have
+//! either a `rustc_symbol_name` or `rustc_item_path` attribute and
+//! generates an error giving, respectively, the symbol name or
+//! item-path. This is used for unit testing the code that generates
+//! paths etc in all kinds of annoying scenarios.
+
+use base::llvm_linkage_by_name;
+use glue::DropGlueKind;
+use llvm;
+use monomorphize::Instance;
+use rustc::hir;
+use rustc::hir::def_id::DefId;
+use rustc::ty::{self, Ty, TyCtxt};
+use rustc::ty::subst;
+use std::hash::{Hash, Hasher};
+use syntax::ast::{self, NodeId};
+use syntax::attr;
+use syntax::parse::token;
+
+#[derive(PartialEq, Eq, Clone, Copy, Debug)]
+pub enum TransItem<'tcx> {
+    DropGlue(DropGlueKind<'tcx>),
+    Fn(Instance<'tcx>),
+    Static(NodeId)
+}
+
+impl<'tcx> Hash for TransItem<'tcx> {
+    fn hash<H: Hasher>(&self, s: &mut H) {
+        match *self {
+            TransItem::DropGlue(t) => {
+                0u8.hash(s);
+                t.hash(s);
+            },
+            TransItem::Fn(instance) => {
+                1u8.hash(s);
+                instance.def.hash(s);
+                (instance.substs as *const _ as usize).hash(s);
+            }
+            TransItem::Static(node_id) => {
+                2u8.hash(s);
+                node_id.hash(s);
+            }
+        };
+    }
+}
+
+//=-----------------------------------------------------------------------------
+// TransItem String Keys
+//=-----------------------------------------------------------------------------
+
+// The code below allows for producing a unique string key for a trans item.
+// These keys are used by the handwritten auto-tests, so they need to be
+// predictable and human-readable.
+//
+// Note: A lot of this could looks very similar to what's already in the
+//       ppaux module. It would be good to refactor things so we only have one
+//       parameterizable implementation for printing types.
+
+/// Same as `unique_type_name()` but with the result pushed onto the given
+/// `output` parameter.
+pub fn push_unique_type_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                       t: ty::Ty<'tcx>,
+                                       output: &mut String) {
+    match t.sty {
+        ty::TyBool              => output.push_str("bool"),
+        ty::TyChar              => output.push_str("char"),
+        ty::TyStr               => output.push_str("str"),
+        ty::TyInt(ast::IntTy::Is)    => output.push_str("isize"),
+        ty::TyInt(ast::IntTy::I8)    => output.push_str("i8"),
+        ty::TyInt(ast::IntTy::I16)   => output.push_str("i16"),
+        ty::TyInt(ast::IntTy::I32)   => output.push_str("i32"),
+        ty::TyInt(ast::IntTy::I64)   => output.push_str("i64"),
+        ty::TyUint(ast::UintTy::Us)   => output.push_str("usize"),
+        ty::TyUint(ast::UintTy::U8)   => output.push_str("u8"),
+        ty::TyUint(ast::UintTy::U16)  => output.push_str("u16"),
+        ty::TyUint(ast::UintTy::U32)  => output.push_str("u32"),
+        ty::TyUint(ast::UintTy::U64)  => output.push_str("u64"),
+        ty::TyFloat(ast::FloatTy::F32) => output.push_str("f32"),
+        ty::TyFloat(ast::FloatTy::F64) => output.push_str("f64"),
+        ty::TyStruct(adt_def, substs) |
+        ty::TyEnum(adt_def, substs) => {
+            push_item_name(tcx, adt_def.did, output);
+            push_type_params(tcx, &substs.types, &[], output);
+        },
+        ty::TyTuple(component_types) => {
+            output.push('(');
+            for &component_type in component_types {
+                push_unique_type_name(tcx, component_type, output);
+                output.push_str(", ");
+            }
+            if !component_types.is_empty() {
+                output.pop();
+                output.pop();
+            }
+            output.push(')');
+        },
+        ty::TyBox(inner_type) => {
+            output.push_str("Box<");
+            push_unique_type_name(tcx, inner_type, output);
+            output.push('>');
+        },
+        ty::TyRawPtr(ty::TypeAndMut { ty: inner_type, mutbl } ) => {
+            output.push('*');
+            match mutbl {
+                hir::MutImmutable => output.push_str("const "),
+                hir::MutMutable => output.push_str("mut "),
+            }
+
+            push_unique_type_name(tcx, inner_type, output);
+        },
+        ty::TyRef(_, ty::TypeAndMut { ty: inner_type, mutbl }) => {
+            output.push('&');
+            if mutbl == hir::MutMutable {
+                output.push_str("mut ");
+            }
+
+            push_unique_type_name(tcx, inner_type, output);
+        },
+        ty::TyArray(inner_type, len) => {
+            output.push('[');
+            push_unique_type_name(tcx, inner_type, output);
+            output.push_str(&format!("; {}", len));
+            output.push(']');
+        },
+        ty::TySlice(inner_type) => {
+            output.push('[');
+            push_unique_type_name(tcx, inner_type, output);
+            output.push(']');
+        },
+        ty::TyTrait(ref trait_data) => {
+            push_item_name(tcx, trait_data.principal.skip_binder().def_id, output);
+            push_type_params(tcx,
+                             &trait_data.principal.skip_binder().substs.types,
+                             &trait_data.bounds.projection_bounds,
+                             output);
+        },
+        ty::TyFnDef(_, _, &ty::BareFnTy{ unsafety, abi, ref sig } ) |
+        ty::TyFnPtr(&ty::BareFnTy{ unsafety, abi, ref sig } ) => {
+            if unsafety == hir::Unsafety::Unsafe {
+                output.push_str("unsafe ");
+            }
+
+            if abi != ::abi::Abi::Rust {
+                output.push_str("extern \"");
+                output.push_str(abi.name());
+                output.push_str("\" ");
+            }
+
+            output.push_str("fn(");
+
+            let sig = tcx.erase_late_bound_regions(sig);
+            if !sig.inputs.is_empty() {
+                for &parameter_type in &sig.inputs {
+                    push_unique_type_name(tcx, parameter_type, output);
+                    output.push_str(", ");
+                }
+                output.pop();
+                output.pop();
+            }
+
+            if sig.variadic {
+                if !sig.inputs.is_empty() {
+                    output.push_str(", ...");
+                } else {
+                    output.push_str("...");
+                }
+            }
+
+            output.push(')');
+
+            match sig.output {
+                ty::FnConverging(result_type) if result_type.is_nil() => {}
+                ty::FnConverging(result_type) => {
+                    output.push_str(" -> ");
+                    push_unique_type_name(tcx, result_type, output);
+                }
+                ty::FnDiverging => {
+                    output.push_str(" -> !");
+                }
+            }
+        },
+        ty::TyClosure(def_id, ref closure_substs) => {
+            push_item_name(tcx, def_id, output);
+            output.push_str("{");
+            output.push_str(&format!("{}:{}", def_id.krate, def_id.index.as_usize()));
+            output.push_str("}");
+            push_type_params(tcx, &closure_substs.func_substs.types, &[], output);
+        }
+        ty::TyError |
+        ty::TyInfer(_) |
+        ty::TyProjection(..) |
+        ty::TyParam(_) => {
+            bug!("debuginfo: Trying to create type name for \
+                  unexpected type: {:?}", t);
+        }
+    }
+}
+
+fn push_item_name(tcx: TyCtxt,
+                  def_id: DefId,
+                  output: &mut String) {
+    let def_path = tcx.def_path(def_id);
+
+    // some_crate::
+    output.push_str(&tcx.crate_name(def_path.krate));
+    output.push_str("::");
+
+    // foo::bar::ItemName::
+    for part in tcx.def_path(def_id).data {
+        output.push_str(&format!("{}[{}]::",
+                        part.data.as_interned_str(),
+                        part.disambiguator));
+    }
+
+    // remove final "::"
+    output.pop();
+    output.pop();
+}
+
+fn push_type_params<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                              types: &'tcx subst::VecPerParamSpace<Ty<'tcx>>,
+                              projections: &[ty::PolyProjectionPredicate<'tcx>],
+                              output: &mut String) {
+    if types.is_empty() && projections.is_empty() {
+        return;
+    }
+
+    output.push('<');
+
+    for &type_parameter in types {
+        push_unique_type_name(tcx, type_parameter, output);
+        output.push_str(", ");
+    }
+
+    for projection in projections {
+        let projection = projection.skip_binder();
+        let name = token::get_ident_interner().get(projection.projection_ty.item_name);
+        output.push_str(&name[..]);
+        output.push_str("=");
+        push_unique_type_name(tcx, projection.ty, output);
+        output.push_str(", ");
+    }
+
+    output.pop();
+    output.pop();
+
+    output.push('>');
+}
+
+fn push_instance_as_string<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                     instance: Instance<'tcx>,
+                                     output: &mut String) {
+    push_item_name(tcx, instance.def, output);
+    push_type_params(tcx, &instance.substs.types, &[], output);
+}
+
+pub fn def_id_to_string(tcx: TyCtxt, def_id: DefId) -> String {
+    let mut output = String::new();
+    push_item_name(tcx, def_id, &mut output);
+    output
+}
+
+pub fn type_to_string<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                ty: ty::Ty<'tcx>)
+                                -> String {
+    let mut output = String::new();
+    push_unique_type_name(tcx, ty, &mut output);
+    output
+}
+
+impl<'tcx> TransItem<'tcx> {
+
+    pub fn requests_inline<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> bool {
+        match *self {
+            TransItem::Fn(ref instance) => {
+                let attributes = tcx.get_attrs(instance.def);
+                attr::requests_inline(&attributes[..])
+            }
+            TransItem::DropGlue(..) => true,
+            TransItem::Static(..)   => false,
+        }
+    }
+
+    pub fn is_from_extern_crate(&self) -> bool {
+        match *self {
+            TransItem::Fn(ref instance) => !instance.def.is_local(),
+            TransItem::DropGlue(..) |
+            TransItem::Static(..)   => false,
+        }
+    }
+
+    pub fn is_lazily_instantiated(&self) -> bool {
+        match *self {
+            TransItem::Fn(ref instance) => !instance.substs.types.is_empty(),
+            TransItem::DropGlue(..) => true,
+            TransItem::Static(..)   => false,
+        }
+    }
+
+    pub fn explicit_linkage<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Option<llvm::Linkage> {
+        let def_id = match *self {
+            TransItem::Fn(ref instance) => instance.def,
+            TransItem::Static(node_id) => tcx.map.local_def_id(node_id),
+            TransItem::DropGlue(..) => return None,
+        };
+
+        let attributes = tcx.get_attrs(def_id);
+        if let Some(name) = attr::first_attr_value_str_by_name(&attributes, "linkage") {
+            if let Some(linkage) = llvm_linkage_by_name(&name) {
+                Some(linkage)
+            } else {
+                let span = tcx.map.span_if_local(def_id);
+                if let Some(span) = span {
+                    tcx.sess.span_fatal(span, "invalid linkage specified")
+                } else {
+                    tcx.sess.fatal(&format!("invalid linkage specified: {}", name))
+                }
+            }
+        } else {
+            None
+        }
+    }
+
+    pub fn to_string<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> String {
+        let hir_map = &tcx.map;
+
+        return match *self {
+            TransItem::DropGlue(dg) => {
+                let mut s = String::with_capacity(32);
+                match dg {
+                    DropGlueKind::Ty(_) => s.push_str("drop-glue "),
+                    DropGlueKind::TyContents(_) => s.push_str("drop-glue-contents "),
+                };
+                push_unique_type_name(tcx, dg.ty(), &mut s);
+                s
+            }
+            TransItem::Fn(instance) => {
+                to_string_internal(tcx, "fn ", instance)
+            },
+            TransItem::Static(node_id) => {
+                let def_id = hir_map.local_def_id(node_id);
+                let empty_substs = tcx.mk_substs(subst::Substs::empty());
+                let instance = Instance::new(def_id, empty_substs);
+                to_string_internal(tcx, "static ", instance)
+            },
+        };
+
+        fn to_string_internal<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                        prefix: &str,
+                                        instance: Instance<'tcx>)
+                                        -> String {
+            let mut result = String::with_capacity(32);
+            result.push_str(prefix);
+            push_instance_as_string(tcx, instance, &mut result);
+            result
+        }
+    }
+
+    pub fn to_raw_string(&self) -> String {
+        match *self {
+            TransItem::DropGlue(dg) => {
+                format!("DropGlue({})", dg.ty() as *const _ as usize)
+            }
+            TransItem::Fn(instance) => {
+                format!("Fn({:?}, {})",
+                         instance.def,
+                         instance.substs as *const _ as usize)
+            }
+            TransItem::Static(id) => {
+                format!("Static({:?})", id)
+            }
+        }
+    }
+}
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 6dfad749982..8f9e44c1365 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -1153,7 +1153,8 @@ fn check_const<'a,'tcx>(ccx: &CrateCtxt<'a,'tcx>,
                         sp: Span,
                         e: &'tcx hir::Expr,
                         id: ast::NodeId) {
-    ccx.inherited(None).enter(|inh| {
+    let param_env = ParameterEnvironment::for_item(ccx.tcx, id);
+    ccx.inherited(Some(param_env)).enter(|inh| {
         let rty = ccx.tcx.node_id_to_type(id);
         let fcx = FnCtxt::new(&inh, ty::FnConverging(rty), e.id);
         let declty = fcx.tcx.lookup_item_type(ccx.tcx.map.local_def_id(id)).ty;
diff --git a/src/libstd/sys/common/gnu/libbacktrace.rs b/src/libstd/sys/common/gnu/libbacktrace.rs
index db719ccce61..b5802afc109 100644
--- a/src/libstd/sys/common/gnu/libbacktrace.rs
+++ b/src/libstd/sys/common/gnu/libbacktrace.rs
@@ -15,7 +15,6 @@ use sys_common::backtrace::{output, output_fileline};
 
 pub fn print(w: &mut Write, idx: isize, addr: *mut libc::c_void,
              symaddr: *mut libc::c_void) -> io::Result<()> {
-    use env;
     use ffi::CStr;
     use ptr;
 
@@ -110,46 +109,22 @@ pub fn print(w: &mut Write, idx: isize, addr: *mut libc::c_void,
     // that is calculated the first time this is requested. Remember that
     // backtracing all happens serially (one global lock).
     //
-    // An additionally oddity in this function is that we initialize the
-    // filename via self_exe_name() to pass to libbacktrace. It turns out
-    // that on Linux libbacktrace seamlessly gets the filename of the
-    // current executable, but this fails on freebsd. by always providing
-    // it, we make sure that libbacktrace never has a reason to not look up
-    // the symbols. The libbacktrace API also states that the filename must
-    // be in "permanent memory", so we copy it to a static and then use the
-    // static as the pointer.
+    // Things don't work so well on not-Linux since libbacktrace can't track
+    // down that executable this is. We at one point used env::current_exe but
+    // it turns out that there are some serious security issues with that
+    // approach.
     //
-    // FIXME: We also call self_exe_name() on DragonFly BSD. I haven't
-    //        tested if this is required or not.
+    // Specifically, on certain platforms like BSDs, a malicious actor can cause
+    // an arbitrary file to be placed at the path returned by current_exe.
+    // libbacktrace does not behave defensively in the presence of ill-formed
+    // DWARF information, and has been demonstrated to segfault in at least one
+    // case. There is no evidence at the moment to suggest that a more carefully
+    // constructed file can't cause arbitrary code execution. As a result of all
+    // of this, we don't hint libbacktrace with the path to the current process.
     unsafe fn init_state() -> *mut backtrace_state {
         static mut STATE: *mut backtrace_state = ptr::null_mut();
-        static mut LAST_FILENAME: [libc::c_char; 256] = [0; 256];
         if !STATE.is_null() { return STATE }
-        let selfname = if cfg!(target_os = "freebsd") ||
-            cfg!(target_os = "dragonfly") ||
-            cfg!(target_os = "bitrig") ||
-            cfg!(target_os = "openbsd") ||
-            cfg!(target_os = "windows") {
-                env::current_exe().ok()
-            } else {
-                None
-            };
-        let filename = match selfname.as_ref().and_then(|s| s.to_str()) {
-            Some(path) => {
-                let bytes = path.as_bytes();
-                if bytes.len() < LAST_FILENAME.len() {
-                    let i = bytes.iter();
-                    for (slot, val) in LAST_FILENAME.iter_mut().zip(i) {
-                        *slot = *val as libc::c_char;
-                    }
-                    LAST_FILENAME.as_ptr()
-                } else {
-                    ptr::null()
-                }
-            }
-            None => ptr::null(),
-        };
-        STATE = backtrace_create_state(filename, 0, error_cb,
+        STATE = backtrace_create_state(ptr::null(), 0, error_cb,
                                        ptr::null_mut());
         STATE
     }
diff --git a/src/test/codegen-units/item-collection/drop_in_place_intrinsic.rs b/src/test/codegen-units/item-collection/drop_in_place_intrinsic.rs
new file mode 100644
index 00000000000..db940b68047
--- /dev/null
+++ b/src/test/codegen-units/item-collection/drop_in_place_intrinsic.rs
@@ -0,0 +1,41 @@
+// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-tidy-linelength
+// compile-flags:-Zprint-trans-items=eager
+
+//~ TRANS_ITEM drop-glue drop_in_place_intrinsic::StructWithDtor[0]
+//~ TRANS_ITEM drop-glue-contents drop_in_place_intrinsic::StructWithDtor[0]
+struct StructWithDtor(u32);
+
+impl Drop for StructWithDtor {
+    //~ TRANS_ITEM fn drop_in_place_intrinsic::{{impl}}[0]::drop[0]
+    fn drop(&mut self) {}
+}
+
+//~ TRANS_ITEM fn drop_in_place_intrinsic::main[0]
+fn main() {
+
+    //~ TRANS_ITEM drop-glue [drop_in_place_intrinsic::StructWithDtor[0]; 2]
+    let x = [StructWithDtor(0), StructWithDtor(1)];
+
+    drop_slice_in_place(&x);
+}
+
+//~ TRANS_ITEM fn drop_in_place_intrinsic::drop_slice_in_place[0]
+fn drop_slice_in_place(x: &[StructWithDtor]) {
+    unsafe {
+        // This is the interesting thing in this test case: Normally we would
+        // not have drop-glue for the unsized [StructWithDtor]. This has to be
+        // generated though when the drop_in_place() intrinsic is used.
+        //~ TRANS_ITEM drop-glue [drop_in_place_intrinsic::StructWithDtor[0]]
+        ::std::ptr::drop_in_place(x as *const _ as *mut [StructWithDtor]);
+    }
+}
diff --git a/src/test/codegen-units/item-collection/static-init.rs b/src/test/codegen-units/item-collection/static-init.rs
new file mode 100644
index 00000000000..41c0f46f80b
--- /dev/null
+++ b/src/test/codegen-units/item-collection/static-init.rs
@@ -0,0 +1,23 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags:-Zprint-trans-items=eager
+
+pub static FN : fn() = foo::<i32>;
+
+pub fn foo<T>() { }
+
+//~ TRANS_ITEM fn static_init::foo[0]<i32>
+//~ TRANS_ITEM static static_init::FN[0]
+
+fn main() { }
+
+//~ TRANS_ITEM fn static_init::main[0]
+//~ TRANS_ITEM drop-glue i8
diff --git a/src/test/codegen-units/partitioning/local-drop-glue.rs b/src/test/codegen-units/partitioning/local-drop-glue.rs
index 1edc3d5d2e2..04ebef645ec 100644
--- a/src/test/codegen-units/partitioning/local-drop-glue.rs
+++ b/src/test/codegen-units/partitioning/local-drop-glue.rs
@@ -23,7 +23,7 @@ struct Struct {
 }
 
 impl Drop for Struct {
-    //~ TRANS_ITEM fn local_drop_glue::{{impl}}[0]::drop[0] @@ local_drop_glue[WeakODR] local_drop_glue-mod1[Declaration]
+    //~ TRANS_ITEM fn local_drop_glue::{{impl}}[0]::drop[0] @@ local_drop_glue[WeakODR]
     fn drop(&mut self) {}
 }
 
diff --git a/src/test/codegen-units/partitioning/local-generic.rs b/src/test/codegen-units/partitioning/local-generic.rs
index 4c762ebdc2e..e38e676b95c 100644
--- a/src/test/codegen-units/partitioning/local-generic.rs
+++ b/src/test/codegen-units/partitioning/local-generic.rs
@@ -19,10 +19,10 @@
 // Used in different modules/codegen units but always instantiated in the same
 // codegen unit.
 
-//~ TRANS_ITEM fn local_generic::generic[0]<u32> @@ local_generic.volatile[WeakODR] local_generic[Declaration]
-//~ TRANS_ITEM fn local_generic::generic[0]<u64> @@ local_generic.volatile[WeakODR] local_generic-mod1[Declaration]
-//~ TRANS_ITEM fn local_generic::generic[0]<char> @@ local_generic.volatile[WeakODR] local_generic-mod1-mod1[Declaration]
-//~ TRANS_ITEM fn local_generic::generic[0]<&str> @@ local_generic.volatile[WeakODR] local_generic-mod2[Declaration]
+//~ TRANS_ITEM fn local_generic::generic[0]<u32> @@ local_generic.volatile[WeakODR]
+//~ TRANS_ITEM fn local_generic::generic[0]<u64> @@ local_generic.volatile[WeakODR]
+//~ TRANS_ITEM fn local_generic::generic[0]<char> @@ local_generic.volatile[WeakODR]
+//~ TRANS_ITEM fn local_generic::generic[0]<&str> @@ local_generic.volatile[WeakODR]
 pub fn generic<T>(x: T) -> T { x }
 
 //~ TRANS_ITEM fn local_generic::user[0] @@ local_generic[WeakODR]
diff --git a/src/test/codegen-units/partitioning/methods-are-with-self-type.rs b/src/test/codegen-units/partitioning/methods-are-with-self-type.rs
index 390bade153c..99dda0e38ba 100644
--- a/src/test/codegen-units/partitioning/methods-are-with-self-type.rs
+++ b/src/test/codegen-units/partitioning/methods-are-with-self-type.rs
@@ -61,19 +61,19 @@ mod type2 {
 //~ TRANS_ITEM fn methods_are_with_self_type::main[0]
 fn main()
 {
-    //~ TRANS_ITEM fn methods_are_with_self_type::mod1[0]::{{impl}}[1]::method[0]<u32, u64> @@ methods_are_with_self_type.volatile[WeakODR] methods_are_with_self_type[Declaration]
+    //~ TRANS_ITEM fn methods_are_with_self_type::mod1[0]::{{impl}}[1]::method[0]<u32, u64> @@ methods_are_with_self_type.volatile[WeakODR]
     SomeGenericType(0u32, 0u64).method();
-    //~ TRANS_ITEM fn methods_are_with_self_type::mod1[0]::{{impl}}[1]::associated_fn[0]<char, &str> @@ methods_are_with_self_type.volatile[WeakODR] methods_are_with_self_type[Declaration]
+    //~ TRANS_ITEM fn methods_are_with_self_type::mod1[0]::{{impl}}[1]::associated_fn[0]<char, &str> @@ methods_are_with_self_type.volatile[WeakODR]
     SomeGenericType::associated_fn('c', "&str");
 
-    //~ TRANS_ITEM fn methods_are_with_self_type::{{impl}}[0]::foo[0]<methods_are_with_self_type::type1[0]::Struct[0]> @@ methods_are_with_self_type-type1.volatile[WeakODR] methods_are_with_self_type[Declaration]
+    //~ TRANS_ITEM fn methods_are_with_self_type::{{impl}}[0]::foo[0]<methods_are_with_self_type::type1[0]::Struct[0]> @@ methods_are_with_self_type-type1.volatile[WeakODR]
     type1::Struct.foo();
-    //~ TRANS_ITEM fn methods_are_with_self_type::{{impl}}[0]::foo[0]<methods_are_with_self_type::type2[0]::Struct[0]> @@ methods_are_with_self_type-type2.volatile[WeakODR] methods_are_with_self_type[Declaration]
+    //~ TRANS_ITEM fn methods_are_with_self_type::{{impl}}[0]::foo[0]<methods_are_with_self_type::type2[0]::Struct[0]> @@ methods_are_with_self_type-type2.volatile[WeakODR]
     type2::Struct.foo();
 
-    //~ TRANS_ITEM fn methods_are_with_self_type::Trait[0]::default[0]<methods_are_with_self_type::type1[0]::Struct[0]> @@ methods_are_with_self_type-type1.volatile[WeakODR] methods_are_with_self_type[Declaration]
+    //~ TRANS_ITEM fn methods_are_with_self_type::Trait[0]::default[0]<methods_are_with_self_type::type1[0]::Struct[0]> @@ methods_are_with_self_type-type1.volatile[WeakODR]
     type1::Struct.default();
-    //~ TRANS_ITEM fn methods_are_with_self_type::Trait[0]::default[0]<methods_are_with_self_type::type2[0]::Struct[0]> @@ methods_are_with_self_type-type2.volatile[WeakODR] methods_are_with_self_type[Declaration]
+    //~ TRANS_ITEM fn methods_are_with_self_type::Trait[0]::default[0]<methods_are_with_self_type::type2[0]::Struct[0]> @@ methods_are_with_self_type-type2.volatile[WeakODR]
     type2::Struct.default();
 }
 
diff --git a/src/test/run-pass/associated-const-outer-ty-refs.rs b/src/test/run-pass/associated-const-outer-ty-refs.rs
new file mode 100644
index 00000000000..a603b225132
--- /dev/null
+++ b/src/test/run-pass/associated-const-outer-ty-refs.rs
@@ -0,0 +1,21 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+#![feature(associated_consts)]
+
+trait Lattice {
+    const BOTTOM: Self;
+}
+
+// FIXME(#33573): this should work without the 'static lifetime bound.
+impl<T: 'static> Lattice for Option<T> {
+    const BOTTOM: Option<T> = None;
+}
+
+fn main(){}
diff --git a/src/test/run-pass/backtrace-debuginfo.rs b/src/test/run-pass/backtrace-debuginfo.rs
index 8b2b2694882..f42a6ab162b 100644
--- a/src/test/run-pass/backtrace-debuginfo.rs
+++ b/src/test/run-pass/backtrace-debuginfo.rs
@@ -32,11 +32,15 @@ macro_rules! dump_and_die {
     ($($pos:expr),*) => ({
         // FIXME(#18285): we cannot include the current position because
         // the macro span takes over the last frame's file/line.
-        if cfg!(target_os = "macos") ||
-           cfg!(target_os = "ios") ||
-           cfg!(target_os = "android") ||
-           cfg!(all(target_os = "linux", target_arch = "arm")) ||
-           cfg!(all(windows, target_env = "gnu")) {
+        if cfg!(any(target_os = "macos",
+                    target_os = "ios",
+                    target_os = "android",
+                    all(target_os = "linux", target_arch = "arm"),
+                    target_os = "windows",
+                    target_os = "freebsd",
+                    target_os = "dragonfly",
+                    target_os = "bitrig",
+                    target_os = "openbsd")) {
             // skip these platforms as this support isn't implemented yet.
         } else {
             dump_filelines(&[$($pos),*]);
diff --git a/src/test/run-pass/backtrace.rs b/src/test/run-pass/backtrace.rs
index 5b364358a59..ad38dc8f452 100644
--- a/src/test/run-pass/backtrace.rs
+++ b/src/test/run-pass/backtrace.rs
@@ -115,7 +115,7 @@ fn runtest(me: &str) {
 }
 
 fn main() {
-    if cfg!(windows) && cfg!(target_arch = "x86") && cfg!(target_env = "gnu") {
+    if cfg!(windows) && cfg!(target_env = "gnu") {
         return
     }
 
diff --git a/src/tools/tidy/src/bins.rs b/src/tools/tidy/src/bins.rs
index 43475f203d5..e91b8fb0967 100644
--- a/src/tools/tidy/src/bins.rs
+++ b/src/tools/tidy/src/bins.rs
@@ -35,7 +35,7 @@ pub fn check(path: &Path, bad: &mut bool) {
             return
         }
 
-        let metadata = t!(fs::metadata(&file), &file);
+        let metadata = t!(fs::symlink_metadata(&file), &file);
         if metadata.mode() & 0o111 != 0 {
             println!("binary checked into source: {}", file.display());
             *bad = true;