Auto merge of #32156 - pnkfelix:borrowck-on-mir-move-analysis, r=nikomatsakis

Move analysis for MIR borrowck

This PR adds code for doing MIR-based gathering of the moves in a `fn` and the dataflow to determine where uninitialized locations flow to, analogous to how the same thing is done in `borrowck`.

It also adds a couple attributes to print out graphviz visualizations of the analyzed MIR that includes the dataflow analysis results.

cc @nikomatsakis

33 files changed, 2013 insertions, 135 deletions

diff --git a/src/libgraphviz/lib.rs b/src/libgraphviz/lib.rs
index 2e26cc1b266..f1317e80b03 100644
--- a/src/libgraphviz/lib.rs
+++ b/src/libgraphviz/lib.rs
@@ -62,7 +62,9 @@
 //!     dot::render(&edges, output).unwrap()
 //! }
 //!
-//! impl<'a> dot::Labeller<'a, Nd, Ed> for Edges {
+//! impl<'a> dot::Labeller<'a> for Edges {
+//!     type Node = Nd;
+//!     type Edge = Ed;
 //!     fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example1").unwrap() }
 //!
 //!     fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
@@ -70,7 +72,9 @@
 //!     }
 //! }
 //!
-//! impl<'a> dot::GraphWalk<'a, Nd, Ed> for Edges {
+//! impl<'a> dot::GraphWalk<'a> for Edges {
+//!     type Node = Nd;
+//!     type Edge = Ed;
 //!     fn nodes(&self) -> dot::Nodes<'a,Nd> {
 //!         // (assumes that |N| \approxeq |E|)
 //!         let &Edges(ref v) = self;
@@ -167,7 +171,9 @@
 //!     dot::render(&graph, output).unwrap()
 //! }
 //!
-//! impl<'a> dot::Labeller<'a, Nd, Ed<'a>> for Graph {
+//! impl<'a> dot::Labeller<'a> for Graph {
+//!     type Node = Nd;
+//!     type Edge = Ed<'a>;
 //!     fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example2").unwrap() }
 //!     fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
 //!         dot::Id::new(format!("N{}", n)).unwrap()
@@ -180,7 +186,9 @@
 //!     }
 //! }
 //!
-//! impl<'a> dot::GraphWalk<'a, Nd, Ed<'a>> for Graph {
+//! impl<'a> dot::GraphWalk<'a> for Graph {
+//!     type Node = Nd;
+//!     type Edge = Ed<'a>;
 //!     fn nodes(&self) -> dot::Nodes<'a,Nd> { (0..self.nodes.len()).collect() }
 //!     fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> { self.edges.iter().collect() }
 //!     fn source(&self, e: &Ed) -> Nd { let & &(s,_) = e; s }
@@ -225,7 +233,9 @@
 //!     dot::render(&graph, output).unwrap()
 //! }
 //!
-//! impl<'a> dot::Labeller<'a, Nd<'a>, Ed<'a>> for Graph {
+//! impl<'a> dot::Labeller<'a> for Graph {
+//!     type Node = Nd<'a>;
+//!     type Edge = Ed<'a>;
 //!     fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example3").unwrap() }
 //!     fn node_id(&'a self, n: &Nd<'a>) -> dot::Id<'a> {
 //!         dot::Id::new(format!("N{}", n.0)).unwrap()
@@ -239,7 +249,9 @@
 //!     }
 //! }
 //!
-//! impl<'a> dot::GraphWalk<'a, Nd<'a>, Ed<'a>> for Graph {
+//! impl<'a> dot::GraphWalk<'a> for Graph {
+//!     type Node = Nd<'a>;
+//!     type Edge = Ed<'a>;
 //!     fn nodes(&'a self) -> dot::Nodes<'a,Nd<'a>> {
 //!         self.nodes.iter().map(|s| &s[..]).enumerate().collect()
 //!     }
@@ -447,45 +459,48 @@ impl<'a> Id<'a> {
 /// The graph instance is responsible for providing the DOT compatible
 /// identifiers for the nodes and (optionally) rendered labels for the nodes and
 /// edges, as well as an identifier for the graph itself.
-pub trait Labeller<'a,N,E> {
+pub trait Labeller<'a> {
+    type Node;
+    type Edge;
+
     /// Must return a DOT compatible identifier naming the graph.
     fn graph_id(&'a self) -> Id<'a>;
 
     /// Maps `n` to a unique identifier with respect to `self`. The
     /// implementor is responsible for ensuring that the returned name
     /// is a valid DOT identifier.
-    fn node_id(&'a self, n: &N) -> Id<'a>;
+    fn node_id(&'a self, n: &Self::Node) -> Id<'a>;
 
     /// Maps `n` to one of the [graphviz `shape` names][1]. If `None`
     /// is returned, no `shape` attribute is specified.
     ///
     /// [1]: http://www.graphviz.org/content/node-shapes
-    fn node_shape(&'a self, _node: &N) -> Option<LabelText<'a>> {
+    fn node_shape(&'a self, _node: &Self::Node) -> Option<LabelText<'a>> {
         None
     }
 
     /// Maps `n` to a label that will be used in the rendered output.
     /// The label need not be unique, and may be the empty string; the
     /// default is just the output from `node_id`.
-    fn node_label(&'a self, n: &N) -> LabelText<'a> {
+    fn node_label(&'a self, n: &Self::Node) -> LabelText<'a> {
         LabelStr(self.node_id(n).name)
     }
 
     /// Maps `e` to a label that will be used in the rendered output.
     /// The label need not be unique, and may be the empty string; the
     /// default is in fact the empty string.
-    fn edge_label(&'a self, e: &E) -> LabelText<'a> {
+    fn edge_label(&'a self, e: &Self::Edge) -> LabelText<'a> {
         let _ignored = e;
         LabelStr("".into_cow())
     }
 
     /// Maps `n` to a style that will be used in the rendered output.
-    fn node_style(&'a self, _n: &N) -> Style {
+    fn node_style(&'a self, _n: &Self::Node) -> Style {
         Style::None
     }
 
     /// Maps `e` to a style that will be used in the rendered output.
-    fn edge_style(&'a self, _e: &E) -> Style {
+    fn edge_style(&'a self, _e: &Self::Edge) -> Style {
         Style::None
     }
 }
@@ -596,15 +611,18 @@ pub type Edges<'a,E> = Cow<'a,[E]>;
 /// `Cow<[T]>` to leave implementors the freedom to create
 /// entirely new vectors or to pass back slices into internally owned
 /// vectors.
-pub trait GraphWalk<'a, N: Clone, E: Clone> {
+pub trait GraphWalk<'a> {
+    type Node: Clone;
+    type Edge: Clone;
+
     /// Returns all the nodes in this graph.
-    fn nodes(&'a self) -> Nodes<'a, N>;
+    fn nodes(&'a self) -> Nodes<'a, Self::Node>;
     /// Returns all of the edges in this graph.
-    fn edges(&'a self) -> Edges<'a, E>;
+    fn edges(&'a self) -> Edges<'a, Self::Edge>;
     /// The source node for `edge`.
-    fn source(&'a self, edge: &E) -> N;
+    fn source(&'a self, edge: &Self::Edge) -> Self::Node;
     /// The target node for `edge`.
-    fn target(&'a self, edge: &E) -> N;
+    fn target(&'a self, edge: &Self::Edge) -> Self::Node;
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
@@ -622,28 +640,26 @@ pub fn default_options() -> Vec<RenderOption> {
 
 /// Renders directed graph `g` into the writer `w` in DOT syntax.
 /// (Simple wrapper around `render_opts` that passes a default set of options.)
-pub fn render<'a,
-              N: Clone + 'a,
-              E: Clone + 'a,
-              G: Labeller<'a, N, E> + GraphWalk<'a, N, E>,
-              W: Write>
-    (g: &'a G,
-     w: &mut W)
-     -> io::Result<()> {
+pub fn render<'a,N,E,G,W>(g: &'a G, w: &mut W) -> io::Result<()>
+    where N: Clone + 'a,
+          E: Clone + 'a,
+          G: Labeller<'a, Node=N, Edge=E> + GraphWalk<'a, Node=N, Edge=E>,
+          W: Write
+{
     render_opts(g, w, &[])
 }
 
 /// Renders directed graph `g` into the writer `w` in DOT syntax.
 /// (Main entry point for the library.)
-pub fn render_opts<'a,
-                   N: Clone + 'a,
-                   E: Clone + 'a,
-                   G: Labeller<'a, N, E> + GraphWalk<'a, N, E>,
-                   W: Write>
-    (g: &'a G,
-     w: &mut W,
-     options: &[RenderOption])
-     -> io::Result<()> {
+pub fn render_opts<'a, N, E, G, W>(g: &'a G,
+                                   w: &mut W,
+                                   options: &[RenderOption])
+                                   -> io::Result<()>
+    where N: Clone + 'a,
+          E: Clone + 'a,
+          G: Labeller<'a, Node=N, Edge=E> + GraphWalk<'a, Node=N, Edge=E>,
+          W: Write
+{
     fn writeln<W: Write>(w: &mut W, arg: &[&str]) -> io::Result<()> {
         for &s in arg {
             try!(w.write_all(s.as_bytes()));
@@ -858,7 +874,9 @@ mod tests {
         Id::new(format!("N{}", *n)).unwrap()
     }
 
-    impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraph {
+    impl<'a> Labeller<'a> for LabelledGraph {
+        type Node = Node;
+        type Edge = &'a Edge;
         fn graph_id(&'a self) -> Id<'a> {
             Id::new(&self.name[..]).unwrap()
         }
@@ -882,7 +900,9 @@ mod tests {
         }
     }
 
-    impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
+    impl<'a> Labeller<'a> for LabelledGraphWithEscStrs {
+        type Node = Node;
+        type Edge = &'a Edge;
         fn graph_id(&'a self) -> Id<'a> {
             self.graph.graph_id()
         }
@@ -901,7 +921,9 @@ mod tests {
         }
     }
 
-    impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraph {
+    impl<'a> GraphWalk<'a> for LabelledGraph {
+        type Node = Node;
+        type Edge = &'a Edge;
         fn nodes(&'a self) -> Nodes<'a, Node> {
             (0..self.node_labels.len()).collect()
         }
@@ -916,7 +938,9 @@ mod tests {
         }
     }
 
-    impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
+    impl<'a> GraphWalk<'a> for LabelledGraphWithEscStrs {
+        type Node = Node;
+        type Edge = &'a Edge;
         fn nodes(&'a self) -> Nodes<'a, Node> {
             self.graph.nodes()
         }
diff --git a/src/librustc/front/map/blocks.rs b/src/librustc/front/map/blocks.rs
index 752b625f529..976a8c6dda0 100644
--- a/src/librustc/front/map/blocks.rs
+++ b/src/librustc/front/map/blocks.rs
@@ -26,7 +26,8 @@ pub use self::Code::*;
 use front::map::{self, Node};
 use syntax::abi;
 use rustc_front::hir::{Block, FnDecl};
-use syntax::ast::{Name, NodeId};
+use syntax::ast::{Attribute, Name, NodeId};
+use syntax::attr::ThinAttributesExt;
 use rustc_front::hir as ast;
 use syntax::codemap::Span;
 use rustc_front::intravisit::FnKind;
@@ -116,7 +117,8 @@ struct ItemFnParts<'a> {
     generics: &'a ast::Generics,
     body:     &'a Block,
     id:       NodeId,
-    span:     Span
+    span:     Span,
+    attrs:    &'a [Attribute],
 }
 
 /// These are all the components one can extract from a closure expr
@@ -125,12 +127,13 @@ struct ClosureParts<'a> {
     decl: &'a FnDecl,
     body: &'a Block,
     id: NodeId,
-    span: Span
+    span: Span,
+    attrs: &'a [Attribute],
 }
 
 impl<'a> ClosureParts<'a> {
-    fn new(d: &'a FnDecl, b: &'a Block, id: NodeId, s: Span) -> ClosureParts<'a> {
-        ClosureParts { decl: d, body: b, id: id, span: s }
+    fn new(d: &'a FnDecl, b: &'a Block, id: NodeId, s: Span, attrs: &'a [Attribute]) -> Self {
+        ClosureParts { decl: d, body: b, id: id, span: s, attrs: attrs }
     }
 }
 
@@ -165,37 +168,37 @@ impl<'a> FnLikeNode<'a> {
 
     pub fn body(self) -> &'a Block {
         self.handle(|i: ItemFnParts<'a>|  &*i.body,
-                    |_, _, _: &'a ast::MethodSig, _, body: &'a ast::Block, _|  body,
+                    |_, _, _: &'a ast::MethodSig, _, body: &'a ast::Block, _, _|  body,
                     |c: ClosureParts<'a>| c.body)
     }
 
     pub fn decl(self) -> &'a FnDecl {
         self.handle(|i: ItemFnParts<'a>|  &*i.decl,
-                    |_, _, sig: &'a ast::MethodSig, _, _, _|  &sig.decl,
+                    |_, _, sig: &'a ast::MethodSig, _, _, _, _|  &sig.decl,
                     |c: ClosureParts<'a>| c.decl)
     }
 
     pub fn span(self) -> Span {
         self.handle(|i: ItemFnParts|     i.span,
-                    |_, _, _: &'a ast::MethodSig, _, _, span| span,
+                    |_, _, _: &'a ast::MethodSig, _, _, span, _| span,
                     |c: ClosureParts|    c.span)
     }
 
     pub fn id(self) -> NodeId {
         self.handle(|i: ItemFnParts|     i.id,
-                    |id, _, _: &'a ast::MethodSig, _, _, _| id,
+                    |id, _, _: &'a ast::MethodSig, _, _, _, _| id,
                     |c: ClosureParts|    c.id)
     }
 
     pub fn kind(self) -> FnKind<'a> {
         let item = |p: ItemFnParts<'a>| -> FnKind<'a> {
-            FnKind::ItemFn(p.name, p.generics, p.unsafety, p.constness, p.abi, p.vis)
+            FnKind::ItemFn(p.name, p.generics, p.unsafety, p.constness, p.abi, p.vis, p.attrs)
         };
-        let closure = |_: ClosureParts| {
-            FnKind::Closure
+        let closure = |c: ClosureParts<'a>| {
+            FnKind::Closure(c.attrs)
         };
-        let method = |_, name: Name, sig: &'a ast::MethodSig, vis, _, _| {
-            FnKind::Method(name, sig, vis)
+        let method = |_, name: Name, sig: &'a ast::MethodSig, vis, _, _, attrs| {
+            FnKind::Method(name, sig, vis, attrs)
         };
         self.handle(item, method, closure)
     }
@@ -207,7 +210,8 @@ impl<'a> FnLikeNode<'a> {
                   &'a ast::MethodSig,
                   Option<ast::Visibility>,
                   &'a ast::Block,
-                  Span)
+                  Span,
+                  &'a [Attribute])
                   -> A,
         C: FnOnce(ClosureParts<'a>) -> A,
     {
@@ -224,20 +228,21 @@ impl<'a> FnLikeNode<'a> {
                         abi: abi,
                         vis: i.vis,
                         constness: constness,
-                        span: i.span
+                        span: i.span,
+                        attrs: &i.attrs,
                     }),
                 _ => panic!("item FnLikeNode that is not fn-like"),
             },
             map::NodeTraitItem(ti) => match ti.node {
                 ast::MethodTraitItem(ref sig, Some(ref body)) => {
-                    method(ti.id, ti.name, sig, None, body, ti.span)
+                    method(ti.id, ti.name, sig, None, body, ti.span, &ti.attrs)
                 }
                 _ => panic!("trait method FnLikeNode that is not fn-like"),
             },
             map::NodeImplItem(ii) => {
                 match ii.node {
                     ast::ImplItemKind::Method(ref sig, ref body) => {
-                        method(ii.id, ii.name, sig, Some(ii.vis), body, ii.span)
+                        method(ii.id, ii.name, sig, Some(ii.vis), body, ii.span, &ii.attrs)
                     }
                     _ => {
                         panic!("impl method FnLikeNode that is not fn-like")
@@ -246,7 +251,11 @@ impl<'a> FnLikeNode<'a> {
             }
             map::NodeExpr(e) => match e.node {
                 ast::ExprClosure(_, ref decl, ref block) =>
-                    closure(ClosureParts::new(&decl, &block, e.id, e.span)),
+                    closure(ClosureParts::new(&decl,
+                                              &block,
+                                              e.id,
+                                              e.span,
+                                              e.attrs.as_attr_slice())),
                 _ => panic!("expr FnLikeNode that is not fn-like"),
             },
             _ => panic!("other FnLikeNode that is not fn-like"),
diff --git a/src/librustc/middle/cfg/graphviz.rs b/src/librustc/middle/cfg/graphviz.rs
index e8070925070..c9c712c2d6e 100644
--- a/src/librustc/middle/cfg/graphviz.rs
+++ b/src/librustc/middle/cfg/graphviz.rs
@@ -52,7 +52,9 @@ fn replace_newline_with_backslash_l(s: String) -> String {
     }
 }
 
-impl<'a, 'ast> dot::Labeller<'a, Node<'a>, Edge<'a>> for LabelledCFG<'a, 'ast> {
+impl<'a, 'ast> dot::Labeller<'a> for LabelledCFG<'a, 'ast> {
+    type Node = Node<'a>;
+    type Edge = Edge<'a>;
     fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new(&self.name[..]).unwrap() }
 
     fn node_id(&'a self, &(i,_): &Node<'a>) -> dot::Id<'a> {
@@ -97,7 +99,9 @@ impl<'a, 'ast> dot::Labeller<'a, Node<'a>, Edge<'a>> for LabelledCFG<'a, 'ast> {
     }
 }
 
-impl<'a> dot::GraphWalk<'a, Node<'a>, Edge<'a>> for &'a cfg::CFG {
+impl<'a> dot::GraphWalk<'a> for &'a cfg::CFG {
+    type Node = Node<'a>;
+    type Edge = Edge<'a>;
     fn nodes(&'a self) -> dot::Nodes<'a, Node<'a>> {
         let mut v = Vec::new();
         self.graph.each_node(|i, nd| { v.push((i, nd)); true });
@@ -116,8 +120,10 @@ impl<'a> dot::GraphWalk<'a, Node<'a>, Edge<'a>> for &'a cfg::CFG {
     }
 }
 
-impl<'a, 'ast> dot::GraphWalk<'a, Node<'a>, Edge<'a>> for LabelledCFG<'a, 'ast>
+impl<'a, 'ast> dot::GraphWalk<'a> for LabelledCFG<'a, 'ast>
 {
+    type Node = Node<'a>;
+    type Edge = Edge<'a>;
     fn nodes(&'a self) -> dot::Nodes<'a, Node<'a>> { self.cfg.nodes() }
     fn edges(&'a self) -> dot::Edges<'a, Edge<'a>> { self.cfg.edges() }
     fn source(&'a self, edge: &Edge<'a>) -> Node<'a> { self.cfg.source(edge) }
diff --git a/src/librustc/middle/check_match.rs b/src/librustc/middle/check_match.rs
index 16e0a334440..b456291b17a 100644
--- a/src/librustc/middle/check_match.rs
+++ b/src/librustc/middle/check_match.rs
@@ -1017,7 +1017,7 @@ fn check_fn(cx: &mut MatchCheckCtxt,
             sp: Span,
             fn_id: NodeId) {
     match kind {
-        FnKind::Closure => {}
+        FnKind::Closure(_) => {}
         _ => cx.param_env = ParameterEnvironment::for_item(cx.tcx, fn_id),
     }
 
diff --git a/src/librustc/middle/const_eval.rs b/src/librustc/middle/const_eval.rs
index 47b6c49fddb..228a7d21007 100644
--- a/src/librustc/middle/const_eval.rs
+++ b/src/librustc/middle/const_eval.rs
@@ -226,10 +226,10 @@ pub fn lookup_const_fn_by_id<'tcx>(tcx: &TyCtxt<'tcx>, def_id: DefId)
     };
 
     match fn_like.kind() {
-        FnKind::ItemFn(_, _, _, hir::Constness::Const, _, _) => {
+        FnKind::ItemFn(_, _, _, hir::Constness::Const, _, _, _) => {
             Some(fn_like)
         }
-        FnKind::Method(_, m, _) => {
+        FnKind::Method(_, m, _, _) => {
             if m.constness == hir::Constness::Const {
                 Some(fn_like)
             } else {
diff --git a/src/librustc/middle/dataflow.rs b/src/librustc/middle/dataflow.rs
index c746fab3ea1..de3f7f1b086 100644
--- a/src/librustc/middle/dataflow.rs
+++ b/src/librustc/middle/dataflow.rs
@@ -653,7 +653,7 @@ fn set_bit(words: &mut [usize], bit: usize) -> bool {
     let word = bit / usize_bits;
     let bit_in_word = bit % usize_bits;
     let bit_mask = 1 << bit_in_word;
-    debug!("word={} bit_in_word={} bit_mask={}", word, bit_in_word, word);
+    debug!("word={} bit_in_word={} bit_mask={}", word, bit_in_word, bit_mask);
     let oldv = words[word];
     let newv = oldv | bit_mask;
     words[word] = newv;
diff --git a/src/librustc/middle/effect.rs b/src/librustc/middle/effect.rs
index e6821cf639e..d4ff4b797c8 100644
--- a/src/librustc/middle/effect.rs
+++ b/src/librustc/middle/effect.rs
@@ -82,9 +82,9 @@ impl<'a, 'tcx, 'v> Visitor<'v> for EffectCheckVisitor<'a, 'tcx> {
                 block: &'v hir::Block, span: Span, _: ast::NodeId) {
 
         let (is_item_fn, is_unsafe_fn) = match fn_kind {
-            FnKind::ItemFn(_, _, unsafety, _, _, _) =>
+            FnKind::ItemFn(_, _, unsafety, _, _, _, _) =>
                 (true, unsafety == hir::Unsafety::Unsafe),
-            FnKind::Method(_, sig, _) =>
+            FnKind::Method(_, sig, _, _) =>
                 (true, sig.unsafety == hir::Unsafety::Unsafe),
             _ => (false, false),
         };
diff --git a/src/librustc/middle/infer/region_inference/graphviz.rs b/src/librustc/middle/infer/region_inference/graphviz.rs
index b6c9b5636d9..23559e7b340 100644
--- a/src/librustc/middle/infer/region_inference/graphviz.rs
+++ b/src/librustc/middle/infer/region_inference/graphviz.rs
@@ -173,7 +173,9 @@ impl<'a, 'tcx> ConstraintGraph<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> dot::Labeller<'a, Node, Edge> for ConstraintGraph<'a, 'tcx> {
+impl<'a, 'tcx> dot::Labeller<'a> for ConstraintGraph<'a, 'tcx> {
+    type Node = Node;
+    type Edge = Edge;
     fn graph_id(&self) -> dot::Id {
         dot::Id::new(&*self.graph_name).unwrap()
     }
@@ -224,7 +226,9 @@ fn edge_to_nodes(e: &Edge) -> (Node, Node) {
     }
 }
 
-impl<'a, 'tcx> dot::GraphWalk<'a, Node, Edge> for ConstraintGraph<'a, 'tcx> {
+impl<'a, 'tcx> dot::GraphWalk<'a> for ConstraintGraph<'a, 'tcx> {
+    type Node = Node;
+    type Edge = Edge;
     fn nodes(&self) -> dot::Nodes<Node> {
         let mut set = FnvHashSet();
         for node in self.node_ids.keys() {
diff --git a/src/librustc/middle/intrinsicck.rs b/src/librustc/middle/intrinsicck.rs
index fd857513e5b..233e55cdbb5 100644
--- a/src/librustc/middle/intrinsicck.rs
+++ b/src/librustc/middle/intrinsicck.rs
@@ -226,7 +226,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for IntrinsicCheckingVisitor<'a, 'tcx> {
                 intravisit::walk_fn(self, fk, fd, b, s);
                 self.param_envs.pop();
             }
-            FnKind::Closure => {
+            FnKind::Closure(..) => {
                 intravisit::walk_fn(self, fk, fd, b, s);
             }
         }
diff --git a/src/librustc/middle/resolve_lifetime.rs b/src/librustc/middle/resolve_lifetime.rs
index f29e14f67d7..b5ea365f880 100644
--- a/src/librustc/middle/resolve_lifetime.rs
+++ b/src/librustc/middle/resolve_lifetime.rs
@@ -182,17 +182,17 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
     fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v hir::FnDecl,
                 b: &'v hir::Block, s: Span, fn_id: ast::NodeId) {
         match fk {
-            FnKind::ItemFn(_, generics, _, _, _, _) => {
+            FnKind::ItemFn(_, generics, _, _, _, _, _) => {
                 self.visit_early_late(subst::FnSpace, generics, |this| {
                     this.add_scope_and_walk_fn(fk, fd, b, s, fn_id)
                 })
             }
-            FnKind::Method(_, sig, _) => {
+            FnKind::Method(_, sig, _, _) => {
                 self.visit_early_late(subst::FnSpace, &sig.generics, |this| {
                     this.add_scope_and_walk_fn(fk, fd, b, s, fn_id)
                 })
             }
-            FnKind::Closure => {
+            FnKind::Closure(_) => {
                 self.add_scope_and_walk_fn(fk, fd, b, s, fn_id)
             }
         }
@@ -471,16 +471,16 @@ impl<'a> LifetimeContext<'a> {
                                  fn_id: ast::NodeId) {
 
         match fk {
-            FnKind::ItemFn(_, generics, _, _, _, _) => {
+            FnKind::ItemFn(_, generics, _, _, _, _, _) => {
                 intravisit::walk_fn_decl(self, fd);
                 self.visit_generics(generics);
             }
-            FnKind::Method(_, sig, _) => {
+            FnKind::Method(_, sig, _, _) => {
                 intravisit::walk_fn_decl(self, fd);
                 self.visit_generics(&sig.generics);
                 self.visit_explicit_self(&sig.explicit_self);
             }
-            FnKind::Closure => {
+            FnKind::Closure(_) => {
                 intravisit::walk_fn_decl(self, fd);
             }
         }
diff --git a/src/librustc/mir/repr.rs b/src/librustc/mir/repr.rs
index 06d68af8838..1476c3513dc 100644
--- a/src/librustc/mir/repr.rs
+++ b/src/librustc/mir/repr.rs
@@ -499,13 +499,13 @@ pub enum Lvalue<'tcx> {
 /// or `*B` or `B[index]`. Note that it is parameterized because it is
 /// shared between `Constant` and `Lvalue`. See the aliases
 /// `LvalueProjection` etc below.
-#[derive(Clone, Debug, PartialEq, RustcEncodable, RustcDecodable)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
 pub struct Projection<'tcx, B, V> {
     pub base: B,
     pub elem: ProjectionElem<'tcx, V>,
 }
 
-#[derive(Clone, Debug, PartialEq, RustcEncodable, RustcDecodable)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
 pub enum ProjectionElem<'tcx, V> {
     Deref,
     Field(Field, Ty<'tcx>),
@@ -857,7 +857,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
 /// this does not necessarily mean that they are "==" in Rust -- in
 /// particular one must be wary of `NaN`!
 
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
+#[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
 pub struct Constant<'tcx> {
     pub span: Span,
     pub ty: Ty<'tcx>,
@@ -877,7 +877,7 @@ impl<'tcx> Debug for TypedConstVal<'tcx> {
     }
 }
 
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
+#[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
 pub enum Literal<'tcx> {
     Item {
         def_id: DefId,
diff --git a/src/librustc_borrowck/Cargo.toml b/src/librustc_borrowck/Cargo.toml
index f78f6fb86ae..fdb97bd8d2d 100644
--- a/src/librustc_borrowck/Cargo.toml
+++ b/src/librustc_borrowck/Cargo.toml
@@ -14,3 +14,4 @@ syntax = { path = "../libsyntax" }
 graphviz = { path = "../libgraphviz" }
 rustc = { path = "../librustc" }
 rustc_front = { path = "../librustc_front" }
+rustc_mir = { path = "../librustc_mir" }
diff --git a/src/librustc_borrowck/bitslice.rs b/src/librustc_borrowck/bitslice.rs
new file mode 100644
index 00000000000..a4aa7ae1574
--- /dev/null
+++ b/src/librustc_borrowck/bitslice.rs
@@ -0,0 +1,105 @@
+// Copyright 2012-2016 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 std::mem;
+
+/// `BitSlice` provides helper methods for treating a `[usize]`
+/// as a bitvector.
+pub trait BitSlice {
+    fn clear_bit(&mut self, idx: usize) -> bool;
+    fn set_bit(&mut self, idx: usize) -> bool;
+    fn get_bit(&self, idx: usize) -> bool;
+}
+
+impl BitSlice for [usize] {
+    /// Clears bit at `idx` to 0; returns true iff this changed `self.`
+    fn clear_bit(&mut self, idx: usize) -> bool {
+        let words = self;
+        debug!("clear_bit: words={} idx={}",
+               bits_to_string(words, words.len() * mem::size_of::<usize>()), bit_str(idx));
+        let BitLookup { word, bit_in_word, bit_mask } = bit_lookup(idx);
+        debug!("word={} bit_in_word={} bit_mask={}", word, bit_in_word, bit_mask);
+        let oldv = words[word];
+        let newv = oldv & !bit_mask;
+        words[word] = newv;
+        oldv != newv
+    }
+
+    /// Sets bit at `idx` to 1; returns true iff this changed `self.`
+    fn set_bit(&mut self, idx: usize) -> bool {
+        let words = self;
+        debug!("set_bit: words={} idx={}",
+               bits_to_string(words, words.len() * mem::size_of::<usize>()), bit_str(idx));
+        let BitLookup { word, bit_in_word, bit_mask } = bit_lookup(idx);
+        debug!("word={} bit_in_word={} bit_mask={}", word, bit_in_word, bit_mask);
+        let oldv = words[word];
+        let newv = oldv | bit_mask;
+        words[word] = newv;
+        oldv != newv
+    }
+
+    /// Extracts value of bit at `idx` in `self`.
+    fn get_bit(&self, idx: usize) -> bool {
+        let words = self;
+        let BitLookup { word, bit_mask, .. } = bit_lookup(idx);
+        (words[word] & bit_mask) != 0
+    }
+}
+
+struct BitLookup {
+    /// An index of the word holding the bit in original `[usize]` of query.
+    word: usize,
+    /// Index of the particular bit within the word holding the bit.
+    bit_in_word: usize,
+    /// Word with single 1-bit set corresponding to where the bit is located.
+    bit_mask: usize,
+}
+
+#[inline]
+fn bit_lookup(bit: usize) -> BitLookup {
+    let usize_bits = mem::size_of::<usize>() * 8;
+    let word = bit / usize_bits;
+    let bit_in_word = bit % usize_bits;
+    let bit_mask = 1 << bit_in_word;
+    BitLookup { word: word, bit_in_word: bit_in_word, bit_mask: bit_mask }
+}
+
+
+fn bit_str(bit: usize) -> String {
+    let byte = bit >> 8;
+    let lobits = 1 << (bit & 0xFF);
+    format!("[{}:{}-{:02x}]", bit, byte, lobits)
+}
+
+pub fn bits_to_string(words: &[usize], bytes: usize) -> String {
+    let mut result = String::new();
+    let mut sep = '[';
+
+    // Note: this is a little endian printout of bytes.
+
+    let mut i = 0;
+    for &word in words.iter() {
+        let mut v = word;
+        for _ in 0..mem::size_of::<usize>() {
+            let byte = v & 0xFF;
+            if i >= bytes {
+                assert!(byte == 0);
+            } else {
+                result.push(sep);
+                result.push_str(&format!("{:02x}", byte));
+            }
+            v >>= 8;
+            i += 1;
+            sep = '-';
+        }
+    }
+    result.push(']');
+    return result
+}
diff --git a/src/librustc_borrowck/borrowck/mir/abs_domain.rs b/src/librustc_borrowck/borrowck/mir/abs_domain.rs
new file mode 100644
index 00000000000..aa885eb4742
--- /dev/null
+++ b/src/librustc_borrowck/borrowck/mir/abs_domain.rs
@@ -0,0 +1,62 @@
+// Copyright 2012-2016 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.
+
+//! The move-analysis portion of borrowck needs to work in an abstract
+//! domain of lifted Lvalues.  Most of the Lvalue variants fall into a
+//! one-to-one mapping between the concrete and abstract (e.g. a
+//! field-deref on a local-variable, `x.field`, has the same meaning
+//! in both domains). Indexed-Projections are the exception: `a[x]`
+//! needs to be treated as mapping to the same move path as `a[y]` as
+//! well as `a[13]`, et cetera.
+//!
+//! (In theory the analysis could be extended to work with sets of
+//! paths, so that `a[0]` and `a[13]` could be kept distinct, while
+//! `a[x]` would still overlap them both. But that is not this
+//! representation does today.)
+
+use rustc::mir::repr::{Lvalue, LvalueElem};
+use rustc::mir::repr::{Operand, Projection, ProjectionElem};
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+pub struct AbstractOperand;
+pub type AbstractProjection<'tcx> =
+    Projection<'tcx, Lvalue<'tcx>, AbstractOperand>;
+pub type AbstractElem<'tcx> =
+    ProjectionElem<'tcx, AbstractOperand>;
+
+pub trait Lift {
+    type Abstract;
+    fn lift(&self) -> Self::Abstract;
+}
+impl<'tcx> Lift for Operand<'tcx> {
+    type Abstract = AbstractOperand;
+    fn lift(&self) -> Self::Abstract { AbstractOperand }
+}
+impl<'tcx> Lift for LvalueElem<'tcx> {
+    type Abstract = AbstractElem<'tcx>;
+    fn lift(&self) -> Self::Abstract {
+        match *self {
+            ProjectionElem::Deref =>
+                ProjectionElem::Deref,
+            ProjectionElem::Field(ref f, ty) =>
+                ProjectionElem::Field(f.clone(), ty.clone()),
+            ProjectionElem::Index(ref i) =>
+                ProjectionElem::Index(i.lift()),
+            ProjectionElem::ConstantIndex {offset,min_length,from_end} =>
+                ProjectionElem::ConstantIndex {
+                    offset: offset,
+                    min_length: min_length,
+                    from_end: from_end
+                },
+            ProjectionElem::Downcast(a, u) =>
+                ProjectionElem::Downcast(a.clone(), u.clone()),
+        }
+    }
+}
diff --git a/src/librustc_borrowck/borrowck/mir/dataflow.rs b/src/librustc_borrowck/borrowck/mir/dataflow.rs
new file mode 100644
index 00000000000..69aaae91c49
--- /dev/null
+++ b/src/librustc_borrowck/borrowck/mir/dataflow.rs
@@ -0,0 +1,505 @@
+// Copyright 2012-2016 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 syntax::attr::AttrMetaMethods;
+
+use rustc::middle::ty;
+use rustc::mir::repr::{self, Mir};
+
+use std::io;
+use std::mem;
+use std::usize;
+
+use super::MirBorrowckCtxt;
+use super::gather_moves::{Location, MoveData, MovePathData, MovePathIndex, MoveOutIndex, PathMap};
+use super::graphviz;
+use bitslice::BitSlice; // adds set_bit/get_bit to &[usize] bitvector rep.
+
+pub trait Dataflow {
+    fn dataflow(&mut self);
+}
+
+impl<'b, 'a: 'b, 'tcx: 'a> Dataflow for MirBorrowckCtxt<'b, 'a, 'tcx> {
+    fn dataflow(&mut self) {
+        self.build_gen_and_kill_sets();
+        self.pre_dataflow_instrumentation().unwrap();
+        self.propagate();
+        self.post_dataflow_instrumentation().unwrap();
+    }
+}
+
+struct PropagationContext<'c, 'b: 'c, 'a: 'b, 'tcx: 'a, OnReturn>
+    where OnReturn: Fn(&MoveData, &mut [usize], &repr::Lvalue)
+{
+    mbcx: &'c mut MirBorrowckCtxt<'b, 'a, 'tcx>,
+    changed: bool,
+    on_return: OnReturn
+}
+
+impl<'b, 'a: 'b, 'tcx: 'a> MirBorrowckCtxt<'b, 'a, 'tcx> {
+    fn propagate(&mut self) {
+        let mut temp = vec![0; self.flow_state.sets.words_per_block];
+        let mut propcx = PropagationContext {
+            mbcx: &mut *self,
+            changed: true,
+            on_return: |move_data, in_out, dest_lval| {
+                let move_path_index = move_data.rev_lookup.find(dest_lval);
+                on_all_children_bits(in_out,
+                                     &move_data.path_map,
+                                     &move_data.move_paths,
+                                     move_path_index,
+                                     &|in_out, mpi| {
+                                         in_out.clear_bit(mpi.idx());
+                                     });
+            },
+        };
+        while propcx.changed {
+            propcx.changed = false;
+            propcx.reset(&mut temp);
+            propcx.walk_cfg(&mut temp);
+        }
+    }
+
+    fn build_gen_and_kill_sets(&mut self) {
+        // First we need to build the gen- and kill-sets. The
+        // gather_moves information provides a high-level mapping from
+        // mir-locations to the MoveOuts (and those correspond
+        // directly to gen-sets here). But we still need to figure out
+        // the kill-sets.
+
+        let move_data = &self.flow_state.operator;
+        let move_paths = &move_data.move_paths;
+        let loc_map = &move_data.loc_map;
+        let path_map = &move_data.path_map;
+        let rev_lookup = &move_data.rev_lookup;
+
+        for bb in self.mir.all_basic_blocks() {
+            let &repr::BasicBlockData { ref statements,
+                                        ref terminator,
+                                        is_cleanup: _ } =
+                self.mir.basic_block_data(bb);
+
+            let mut sets = self.flow_state.sets.for_block(bb.index());
+            for (j, stmt) in statements.iter().enumerate() {
+                let loc = Location { block: bb, index: j };
+                debug!("stmt {:?} at loc {:?} moves out of move_indexes {:?}",
+                       stmt, loc, &loc_map[loc]);
+                for move_index in &loc_map[loc] {
+                    // Every path deinitialized by a *particular move*
+                    // has corresponding bit, "gen'ed" (i.e. set)
+                    // here, in dataflow vector
+                    zero_to_one(&mut sets.gen_set, *move_index);
+                }
+                match stmt.kind {
+                    repr::StatementKind::Assign(ref lvalue, _) => {
+                        // assigning into this `lvalue` kills all
+                        // MoveOuts from it, and *also* all MoveOuts
+                        // for children and associated fragment sets.
+                        let move_path_index = rev_lookup.find(lvalue);
+
+                        on_all_children_bits(sets.kill_set,
+                                             path_map,
+                                             move_paths,
+                                             move_path_index,
+                                             &|kill_set, mpi| {
+                                                 kill_set.set_bit(mpi.idx());
+                                             });
+                    }
+                }
+            }
+
+            let loc = Location { block: bb, index: statements.len() };
+            debug!("terminator {:?} at loc {:?} moves out of move_indexes {:?}",
+                   terminator, loc, &loc_map[loc]);
+            for move_index in &loc_map[loc] {
+                zero_to_one(&mut sets.gen_set, *move_index);
+            }
+        }
+
+        fn zero_to_one(gen_set: &mut [usize], move_index: MoveOutIndex) {
+            let retval = gen_set.set_bit(move_index.idx());
+            assert!(retval);
+        }
+    }
+}
+
+fn on_all_children_bits<Each>(set: &mut [usize],
+                              path_map: &PathMap,
+                              move_paths: &MovePathData,
+                              move_path_index: MovePathIndex,
+                              each_child: &Each)
+    where Each: Fn(&mut [usize], MoveOutIndex)
+{
+    // 1. invoke `each_child` callback for all moves that directly
+    //    influence path for `move_path_index`
+    for move_index in &path_map[move_path_index] {
+        each_child(set, *move_index);
+    }
+
+    // 2. for each child of the path (that is named in this
+    //    function), recur.
+    //
+    // (Unnamed children are irrelevant to dataflow; by
+    // definition they have no associated moves.)
+    let mut next_child_index = move_paths[move_path_index].first_child;
+    while let Some(child_index) = next_child_index {
+        on_all_children_bits(set, path_map, move_paths, child_index, each_child);
+        next_child_index = move_paths[child_index].next_sibling;
+    }
+}
+
+impl<'c, 'b: 'c, 'a: 'b, 'tcx: 'a, OnReturn> PropagationContext<'c, 'b, 'a, 'tcx, OnReturn>
+    where OnReturn: Fn(&MoveData, &mut [usize], &repr::Lvalue)
+{
+    fn reset(&mut self, bits: &mut [usize]) {
+        let e = if self.mbcx.flow_state.operator.initial_value() {usize::MAX} else {0};
+        for b in bits {
+            *b = e;
+        }
+    }
+
+    fn walk_cfg(&mut self, in_out: &mut [usize]) {
+        let &mut MirBorrowckCtxt { ref mir, ref mut flow_state, .. } = self.mbcx;
+        for (idx, bb) in mir.basic_blocks.iter().enumerate() {
+            {
+                let sets = flow_state.sets.for_block(idx);
+                debug_assert!(in_out.len() == sets.on_entry.len());
+                in_out.clone_from_slice(sets.on_entry);
+                bitwise(in_out, sets.gen_set, &Union);
+                bitwise(in_out, sets.kill_set, &Subtract);
+            }
+            flow_state.propagate_bits_into_graph_successors_of(in_out,
+                                                               &mut self.changed,
+                                                               bb,
+                                                               &self.on_return);
+        }
+    }
+}
+
+impl<'b, 'a: 'b, 'tcx: 'a> MirBorrowckCtxt<'b, 'a, 'tcx> {
+    fn pre_dataflow_instrumentation(&self) -> io::Result<()> {
+        self.if_attr_meta_name_found(
+            "borrowck_graphviz_preflow",
+            |this, path: &str| {
+                graphviz::print_borrowck_graph_to(this, "preflow", path)
+            })
+    }
+
+    fn post_dataflow_instrumentation(&self) -> io::Result<()> {
+        self.if_attr_meta_name_found(
+            "borrowck_graphviz_postflow",
+            |this, path: &str| {
+                graphviz::print_borrowck_graph_to(this, "postflow", path)
+            })
+    }
+
+    fn if_attr_meta_name_found<F>(&self,
+                                  name: &str,
+                                  callback: F) -> io::Result<()>
+        where F: for <'aa, 'bb> FnOnce(&'aa Self, &'bb str) -> io::Result<()>
+    {
+        for attr in self.attributes {
+            if attr.check_name("rustc_mir") {
+                let items = attr.meta_item_list();
+                for item in items.iter().flat_map(|l| l.iter()) {
+                    if item.check_name(name) {
+                        if let Some(s) = item.value_str() {
+                            return callback(self, &s);
+                        } else {
+                            self.bcx.tcx.sess.span_err(
+                                item.span,
+                                &format!("{} attribute requires a path", item.name()));
+                        }
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+/// Maps each block to a set of bits
+#[derive(Clone, Debug)]
+struct Bits {
+    bits: Vec<usize>,
+}
+
+impl Bits {
+    fn new(init_word: usize, num_words: usize) -> Self {
+        Bits { bits: vec![init_word; num_words] }
+    }
+}
+
+pub struct DataflowState<O: BitDenotation>
+{
+    /// All the sets for the analysis. (Factored into its
+    /// own structure so that we can borrow it mutably
+    /// on its own separate from other fields.)
+    pub sets: AllSets,
+
+    /// operator used to initialize, combine, and interpret bits.
+    operator: O,
+}
+
+pub struct AllSets {
+    /// Analysis bitwidth for each block.
+    bits_per_block: usize,
+
+    /// Number of words associated with each block entry
+    /// equal to bits_per_block / usize::BITS, rounded up.
+    words_per_block: usize,
+
+    /// For each block, bits generated by executing the statements in
+    /// the block. (For comparison, the Terminator for each block is
+    /// handled in a flow-specific manner during propagation.)
+    gen_sets: Bits,
+
+    /// For each block, bits killed by executing the statements in the
+    /// block. (For comparison, the Terminator for each block is
+    /// handled in a flow-specific manner during propagation.)
+    kill_sets: Bits,
+
+    /// For each block, bits valid on entry to the block.
+    on_entry_sets: Bits,
+}
+
+pub struct BlockSets<'a> {
+    on_entry: &'a mut [usize],
+    gen_set: &'a mut [usize],
+    kill_set: &'a mut [usize],
+}
+
+impl AllSets {
+    pub fn bits_per_block(&self) -> usize { self.bits_per_block }
+    pub fn bytes_per_block(&self) -> usize { (self.bits_per_block + 7) / 8 }
+    pub fn for_block(&mut self, block_idx: usize) -> BlockSets {
+        let offset = self.words_per_block * block_idx;
+        let range = offset..(offset + self.words_per_block);
+        BlockSets {
+            on_entry: &mut self.on_entry_sets.bits[range.clone()],
+            gen_set: &mut self.gen_sets.bits[range.clone()],
+            kill_set: &mut self.kill_sets.bits[range],
+        }
+    }
+
+    fn lookup_set_for<'a>(&self, sets: &'a Bits, block_idx: usize) -> &'a [usize] {
+        let offset = self.words_per_block * block_idx;
+        &sets.bits[offset..(offset + self.words_per_block)]
+    }
+    pub fn gen_set_for(&self, block_idx: usize) -> &[usize] {
+        self.lookup_set_for(&self.gen_sets, block_idx)
+    }
+    pub fn kill_set_for(&self, block_idx: usize) -> &[usize] {
+        self.lookup_set_for(&self.kill_sets, block_idx)
+    }
+    pub fn on_entry_set_for(&self, block_idx: usize) -> &[usize] {
+        self.lookup_set_for(&self.on_entry_sets, block_idx)
+    }
+}
+
+impl<O: BitDenotation> DataflowState<O> {
+    fn each_bit<F>(&self, words: &[usize], mut f: F)
+        where F: FnMut(usize) {
+        //! Helper for iterating over the bits in a bitvector.
+
+        for (word_index, &word) in words.iter().enumerate() {
+            if word != 0 {
+                let usize_bits: usize = mem::size_of::<usize>();
+                let base_index = word_index * usize_bits;
+                for offset in 0..usize_bits {
+                    let bit = 1 << offset;
+                    if (word & bit) != 0 {
+                        // NB: we round up the total number of bits
+                        // that we store in any given bit set so that
+                        // it is an even multiple of usize::BITS. This
+                        // means that there may be some stray bits at
+                        // the end that do not correspond to any
+                        // actual value; that's why we first check
+                        // that we are in range of bits_per_block.
+                        let bit_index = base_index + offset as usize;
+                        if bit_index >= self.sets.bits_per_block() {
+                            return;
+                        } else {
+                            f(bit_index);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn interpret_set(&self, words: &[usize]) -> Vec<&O::Bit> {
+        let mut v = Vec::new();
+        self.each_bit(words, |i| {
+            v.push(self.operator.interpret(i));
+        });
+        v
+    }
+}
+
+pub trait BitwiseOperator {
+    /// Joins two predecessor bits together, typically either `|` or `&`
+    fn join(&self, pred1: usize, pred2: usize) -> usize;
+}
+
+/// Parameterization for the precise form of data flow that is used.
+pub trait DataflowOperator : BitwiseOperator {
+    /// Specifies the initial value for each bit in the `on_entry` set
+    fn initial_value(&self) -> bool;
+}
+
+pub trait BitDenotation: DataflowOperator {
+    /// Specifies what is represented by each bit in the dataflow bitvector.
+    type Bit;
+    /// Size of each bivector allocated for each block in the analysis.
+    fn bits_per_block(&self) -> usize;
+    /// Provides the meaning of each entry in the dataflow bitvector.
+    /// (Mostly intended for use for better debug instrumentation.)
+    fn interpret(&self, idx: usize) -> &Self::Bit;
+}
+
+impl<D: BitDenotation> DataflowState<D> {
+    pub fn new(mir: &Mir, denotation: D) -> Self {
+        let bits_per_block = denotation.bits_per_block();
+        let usize_bits = mem::size_of::<usize>() * 8;
+        let words_per_block = (bits_per_block + usize_bits - 1) / usize_bits;
+        let num_blocks = mir.basic_blocks.len();
+        let num_words = num_blocks * words_per_block;
+
+        let entry = if denotation.initial_value() { usize::MAX } else {0};
+
+        let zeroes = Bits::new(0, num_words);
+        let on_entry = Bits::new(entry, num_words);
+
+        DataflowState {
+            sets: AllSets {
+                bits_per_block: bits_per_block,
+                words_per_block: words_per_block,
+                gen_sets: zeroes.clone(),
+                kill_sets: zeroes,
+                on_entry_sets: on_entry,
+            },
+            operator: denotation,
+        }
+    }
+}
+
+impl<D: BitDenotation> DataflowState<D> {
+    /// Propagates the bits of `in_out` into all the successors of `bb`,
+    /// using bitwise operator denoted by `self.operator`.
+    ///
+    /// For most blocks, this is entirely uniform. However, for blocks
+    /// that end with a call terminator, the effect of the call on the
+    /// dataflow state may depend on whether the call returned
+    /// successfully or unwound. To reflect this, the `on_return`
+    /// callback mutates `in_out` when propagating `in_out` via a call
+    /// terminator; such mutation is performed *last*, to ensure its
+    /// side-effects do not leak elsewhere (e.g. into unwind target).
+    fn propagate_bits_into_graph_successors_of<OnReturn>(
+        &mut self,
+        in_out: &mut [usize],
+        changed: &mut bool,
+        bb: &repr::BasicBlockData,
+        on_return: OnReturn) where OnReturn: Fn(&D, &mut [usize], &repr::Lvalue)
+    {
+        let term = if let Some(ref term) = bb.terminator { term } else { return };
+        match *term {
+            repr::Terminator::Return |
+            repr::Terminator::Resume => {}
+            repr::Terminator::Goto { ref target } |
+            repr::Terminator::Drop { ref target, value: _, unwind: None } => {
+                self.propagate_bits_into_entry_set_for(in_out, changed, target);
+            }
+            repr::Terminator::Drop { ref target, value: _, unwind: Some(ref unwind) } => {
+                self.propagate_bits_into_entry_set_for(in_out, changed, target);
+                self.propagate_bits_into_entry_set_for(in_out, changed, unwind);
+            }
+            repr::Terminator::If { ref targets, .. } => {
+                self.propagate_bits_into_entry_set_for(in_out, changed, &targets.0);
+                self.propagate_bits_into_entry_set_for(in_out, changed, &targets.1);
+            }
+            repr::Terminator::Switch { ref targets, .. } |
+            repr::Terminator::SwitchInt { ref targets, .. } => {
+                for target in targets {
+                    self.propagate_bits_into_entry_set_for(in_out, changed, target);
+                }
+            }
+            repr::Terminator::Call { ref cleanup, ref destination, func: _, args: _ } => {
+                if let Some(ref unwind) = *cleanup {
+                    self.propagate_bits_into_entry_set_for(in_out, changed, unwind);
+                }
+                if let Some((ref dest_lval, ref dest_bb)) = *destination {
+                    // N.B.: This must be done *last*, after all other
+                    // propagation, as documented in comment above.
+                    on_return(&self.operator, in_out, dest_lval);
+                    self.propagate_bits_into_entry_set_for(in_out, changed, dest_bb);
+                }
+            }
+        }
+    }
+
+    fn propagate_bits_into_entry_set_for(&mut self,
+                                         in_out: &[usize],
+                                         changed: &mut bool,
+                                         bb: &repr::BasicBlock) {
+        let entry_set = self.sets.for_block(bb.index()).on_entry;
+        let set_changed = bitwise(entry_set, in_out, &self.operator);
+        if set_changed {
+            *changed = true;
+        }
+    }
+}
+
+
+impl<'tcx> DataflowState<MoveData<'tcx>> {
+    pub fn new_move_analysis(mir: &Mir<'tcx>, tcx: &ty::TyCtxt<'tcx>) -> Self {
+        let move_data = MoveData::gather_moves(mir, tcx);
+        DataflowState::new(mir, move_data)
+    }
+}
+
+impl<'tcx> BitwiseOperator for MoveData<'tcx> {
+    #[inline]
+    fn join(&self, pred1: usize, pred2: usize) -> usize {
+        pred1 | pred2 // moves from both preds are in scope
+    }
+}
+
+impl<'tcx> DataflowOperator for MoveData<'tcx> {
+    #[inline]
+    fn initial_value(&self) -> bool {
+        false // no loans in scope by default
+    }
+}
+
+#[inline]
+fn bitwise<Op:BitwiseOperator>(out_vec: &mut [usize],
+                               in_vec: &[usize],
+                               op: &Op) -> bool {
+    assert_eq!(out_vec.len(), in_vec.len());
+    let mut changed = false;
+    for (out_elt, in_elt) in out_vec.iter_mut().zip(in_vec) {
+        let old_val = *out_elt;
+        let new_val = op.join(old_val, *in_elt);
+        *out_elt = new_val;
+        changed |= old_val != new_val;
+    }
+    changed
+}
+
+struct Union;
+impl BitwiseOperator for Union {
+    fn join(&self, a: usize, b: usize) -> usize { a | b }
+}
+struct Subtract;
+impl BitwiseOperator for Subtract {
+    fn join(&self, a: usize, b: usize) -> usize { a & !b }
+}
diff --git a/src/librustc_borrowck/borrowck/mir/gather_moves.rs b/src/librustc_borrowck/borrowck/mir/gather_moves.rs
new file mode 100644
index 00000000000..17a016a3ae3
--- /dev/null
+++ b/src/librustc_borrowck/borrowck/mir/gather_moves.rs
@@ -0,0 +1,747 @@
+// Copyright 2012-2016 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::middle::ty;
+use rustc::mir::repr::{self, Mir, BasicBlock, Lvalue, Rvalue};
+use rustc::mir::repr::{StatementKind, Terminator};
+use rustc::util::nodemap::FnvHashMap;
+
+use std::cell::{Cell};
+use std::collections::hash_map::Entry;
+use std::fmt;
+use std::iter;
+use std::ops::Index;
+
+use super::dataflow::BitDenotation;
+use super::abs_domain::{AbstractElem, Lift};
+
+// This submodule holds some newtype'd Index wrappers that are using
+// NonZero to ensure that Option<Index> occupies only a single word.
+// They are in a submodule to impose privacy restrictions; namely, to
+// ensure that other code does not accidentally access `index.0`
+// (which is likely to yield a subtle off-by-one error).
+mod indexes {
+    use core::nonzero::NonZero;
+
+    macro_rules! new_index {
+        ($Index:ident) => {
+            #[derive(Copy, Clone, PartialEq, Eq, Debug)]
+            pub struct $Index(NonZero<usize>);
+
+            impl $Index {
+                pub fn new(idx: usize) -> Self {
+                    unsafe { $Index(NonZero::new(idx + 1)) }
+                }
+                pub fn idx(&self) -> usize {
+                    *self.0 - 1
+                }
+            }
+        }
+    }
+
+    /// Index into MovePathData.move_paths
+    new_index!(MovePathIndex);
+
+    /// Index into MoveData.moves.
+    new_index!(MoveOutIndex);
+}
+
+pub use self::indexes::MovePathIndex;
+pub use self::indexes::MoveOutIndex;
+
+/// `MovePath` is a canonicalized representation of a path that is
+/// moved or assigned to.
+///
+/// It follows a tree structure.
+///
+/// Given `struct X { m: M, n: N }` and `x: X`, moves like `drop x.m;`
+/// move *out* of the l-value `x.m`.
+///
+/// The MovePaths representing `x.m` and `x.n` are siblings (that is,
+/// one of them will link to the other via the `next_sibling` field,
+/// and the other will have no entry in its `next_sibling` field), and
+/// they both have the MovePath representing `x` as their parent.
+#[derive(Clone)]
+pub struct MovePath<'tcx> {
+    pub next_sibling: Option<MovePathIndex>,
+    pub first_child: Option<MovePathIndex>,
+    pub parent: Option<MovePathIndex>,
+    pub content: MovePathContent<'tcx>,
+}
+
+/// MovePaths usually represent a single l-value. The exceptions are
+/// forms that arise due to erroneous input code: static data holds
+/// l-values that we cannot actually move out of. Therefore we map
+/// statics to a special marker value (`MovePathContent::Static`)
+/// representing an invalid origin.
+#[derive(Clone, Debug)]
+pub enum MovePathContent<'tcx> {
+    Lvalue(Lvalue<'tcx>),
+    Static,
+}
+
+/// During construction of the MovePath's, we use PreMovePath to
+/// represent accumulated state while we are gathering up all the
+/// children of each path.
+#[derive(Clone)]
+struct PreMovePath<'tcx> {
+    pub next_sibling: Option<MovePathIndex>,
+    pub first_child: Cell<Option<MovePathIndex>>,
+    pub parent: Option<MovePathIndex>,
+    pub content: MovePathContent<'tcx>,
+}
+
+impl<'tcx> PreMovePath<'tcx> {
+    fn into_move_path(self) -> MovePath<'tcx> {
+        MovePath {
+            next_sibling: self.next_sibling,
+            parent: self.parent,
+            content: self.content,
+            first_child: self.first_child.get(),
+        }
+    }
+}
+
+impl<'tcx> fmt::Debug for MovePath<'tcx> {
+    fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result {
+        try!(write!(w, "MovePath {{"));
+        if let Some(parent) = self.parent {
+            try!(write!(w, " parent: {:?},", parent));
+        }
+        if let Some(first_child) = self.first_child {
+            try!(write!(w, " first_child: {:?},", first_child));
+        }
+        if let Some(next_sibling) = self.next_sibling {
+            try!(write!(w, " next_sibling: {:?}", next_sibling));
+        }
+        write!(w, " content: {:?} }}", self.content)
+    }
+}
+
+pub struct MoveData<'tcx> {
+    pub move_paths: MovePathData<'tcx>,
+    pub moves: Vec<MoveOut>,
+    pub loc_map: LocMap,
+    pub path_map: PathMap,
+    pub rev_lookup: MovePathLookup<'tcx>,
+}
+
+pub struct LocMap {
+    /// Location-indexed (BasicBlock for outer index, index within BB
+    /// for inner index) map to list of MoveOutIndex's.
+    ///
+    /// Each Location `l` is mapped to the MoveOut's that are effects
+    /// of executing the code at `l`. (There can be multiple MoveOut's
+    /// for a given `l` because each MoveOut is associated with one
+    /// particular path being moved.)
+    map: Vec<Vec<Vec<MoveOutIndex>>>,
+}
+
+impl Index<Location> for LocMap {
+    type Output = [MoveOutIndex];
+    fn index(&self, index: Location) -> &Self::Output {
+        assert!(index.block.index() < self.map.len());
+        assert!(index.index < self.map[index.block.index()].len());
+        &self.map[index.block.index()][index.index]
+    }
+}
+
+pub struct PathMap {
+    /// Path-indexed map to list of MoveOutIndex's.
+    ///
+    /// Each Path `p` is mapped to the MoveOut's that move out of `p`.
+    map: Vec<Vec<MoveOutIndex>>,
+}
+
+impl Index<MovePathIndex> for PathMap {
+    type Output = [MoveOutIndex];
+    fn index(&self, index: MovePathIndex) -> &Self::Output {
+        &self.map[index.idx()]
+    }
+}
+
+/// `MoveOut` represents a point in a program that moves out of some
+/// L-value; i.e., "creates" uninitialized memory.
+///
+/// With respect to dataflow analysis:
+/// - Generated by moves and declaration of uninitialized variables.
+/// - Killed by assignments to the memory.
+#[derive(Copy, Clone)]
+pub struct MoveOut {
+    /// path being moved
+    pub path: MovePathIndex,
+    /// location of move
+    pub source: Location,
+}
+
+impl fmt::Debug for MoveOut {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "p{}@{:?}", self.path.idx(), self.source)
+    }
+}
+
+#[derive(Copy, Clone)]
+pub struct Location {
+    /// block where action is located
+    pub block: BasicBlock,
+    /// index within above block; statement when < statments.len) or
+    /// the terminator (when = statements.len).
+    pub index: usize,
+}
+
+impl fmt::Debug for Location {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{:?}[{}]", self.block, self.index)
+    }
+}
+
+pub struct MovePathData<'tcx> {
+    move_paths: Vec<MovePath<'tcx>>,
+}
+
+impl<'tcx> Index<MovePathIndex> for MovePathData<'tcx> {
+    type Output = MovePath<'tcx>;
+    fn index(&self, i: MovePathIndex) -> &MovePath<'tcx> {
+        &self.move_paths[i.idx()]
+    }
+}
+
+/// MovePathInverseMap maps from a uint in an lvalue-category to the
+/// MovePathIndex for the MovePath for that lvalue.
+type MovePathInverseMap = Vec<Option<MovePathIndex>>;
+
+struct MovePathDataBuilder<'a, 'tcx: 'a> {
+    mir: &'a Mir<'tcx>,
+    pre_move_paths: Vec<PreMovePath<'tcx>>,
+    rev_lookup: MovePathLookup<'tcx>,
+}
+
+/// Tables mapping from an l-value to its MovePathIndex.
+pub struct MovePathLookup<'tcx> {
+    vars: MovePathInverseMap,
+    temps: MovePathInverseMap,
+    args: MovePathInverseMap,
+
+    /// The move path representing the return value is constructed
+    /// lazily when we first encounter it in the input MIR.
+    return_ptr: Option<MovePathIndex>,
+
+    /// A single move path (representing any static data referenced)
+    /// is constructed lazily when we first encounter statics in the
+    /// input MIR.
+    statics: Option<MovePathIndex>,
+
+    /// projections are made from a base-lvalue and a projection
+    /// elem. The base-lvalue will have a unique MovePathIndex; we use
+    /// the latter as the index into the outer vector (narrowing
+    /// subsequent search so that it is solely relative to that
+    /// base-lvalue). For the remaining lookup, we map the projection
+    /// elem to the associated MovePathIndex.
+    projections: Vec<FnvHashMap<AbstractElem<'tcx>, MovePathIndex>>,
+
+    /// Tracks the next index to allocate during construction of the
+    /// MovePathData. Unused after MovePathData is fully constructed.
+    next_index: MovePathIndex,
+}
+
+trait FillTo {
+    type T;
+    fn fill_to_with(&mut self, idx: usize, x: Self::T);
+    fn fill_to(&mut self, idx: usize) where Self::T: Default {
+        self.fill_to_with(idx, Default::default())
+    }
+}
+impl<T:Clone> FillTo for Vec<T> {
+    type T = T;
+    fn fill_to_with(&mut self, idx: usize, x: T) {
+        if idx >= self.len() {
+            let delta = idx + 1 - self.len();
+            assert_eq!(idx + 1, self.len() + delta);
+            self.extend(iter::repeat(x).take(delta))
+        }
+        debug_assert!(idx < self.len());
+    }
+}
+
+#[derive(Clone, Debug)]
+enum LookupKind { Generate, Reuse }
+struct Lookup<T>(LookupKind, T);
+
+impl Lookup<MovePathIndex> {
+    fn idx(&self) -> usize { (self.1).idx() }
+}
+
+impl<'tcx> MovePathLookup<'tcx> {
+    fn new() -> Self {
+        MovePathLookup {
+            vars: vec![],
+            temps: vec![],
+            args: vec![],
+            statics: None,
+            return_ptr: None,
+            projections: vec![],
+            next_index: MovePathIndex::new(0),
+        }
+    }
+
+    fn next_index(next: &mut MovePathIndex) -> MovePathIndex {
+        let i = *next;
+        *next = MovePathIndex::new(i.idx() + 1);
+        i
+    }
+
+    fn lookup_or_generate(vec: &mut Vec<Option<MovePathIndex>>,
+                          idx: u32,
+                          next_index: &mut MovePathIndex) -> Lookup<MovePathIndex> {
+        let idx = idx as usize;
+        vec.fill_to_with(idx, None);
+        let entry = &mut vec[idx];
+        match *entry {
+            None => {
+                let i = Self::next_index(next_index);
+                *entry = Some(i);
+                Lookup(LookupKind::Generate, i)
+            }
+            Some(entry_idx) => {
+                Lookup(LookupKind::Reuse, entry_idx)
+            }
+        }
+    }
+
+    fn lookup_var(&mut self, var_idx: u32) -> Lookup<MovePathIndex> {
+        Self::lookup_or_generate(&mut self.vars,
+                                 var_idx,
+                                 &mut self.next_index)
+    }
+
+    fn lookup_temp(&mut self, temp_idx: u32) -> Lookup<MovePathIndex> {
+        Self::lookup_or_generate(&mut self.temps,
+                                 temp_idx,
+                                 &mut self.next_index)
+    }
+
+    fn lookup_arg(&mut self, arg_idx: u32) -> Lookup<MovePathIndex> {
+        Self::lookup_or_generate(&mut self.args,
+                                 arg_idx,
+                                 &mut self.next_index)
+    }
+
+    fn lookup_static(&mut self) -> Lookup<MovePathIndex> {
+        match self.statics {
+            Some(mpi) => {
+                Lookup(LookupKind::Reuse, mpi)
+            }
+            ref mut ret @ None => {
+                let mpi = Self::next_index(&mut self.next_index);
+                *ret = Some(mpi);
+                Lookup(LookupKind::Generate, mpi)
+            }
+        }
+    }
+
+    fn lookup_return_pointer(&mut self) -> Lookup<MovePathIndex> {
+        match self.return_ptr {
+            Some(mpi) => {
+                Lookup(LookupKind::Reuse, mpi)
+            }
+            ref mut ret @ None => {
+                let mpi = Self::next_index(&mut self.next_index);
+                *ret = Some(mpi);
+                Lookup(LookupKind::Generate, mpi)
+            }
+        }
+    }
+
+    fn lookup_proj(&mut self,
+                   proj: &repr::LvalueProjection<'tcx>,
+                   base: MovePathIndex) -> Lookup<MovePathIndex> {
+        let MovePathLookup { ref mut projections,
+                             ref mut next_index, .. } = *self;
+        projections.fill_to(base.idx());
+        match projections[base.idx()].entry(proj.elem.lift()) {
+            Entry::Occupied(ent) => {
+                Lookup(LookupKind::Reuse, *ent.get())
+            }
+            Entry::Vacant(ent) => {
+                let mpi = Self::next_index(next_index);
+                ent.insert(mpi);
+                Lookup(LookupKind::Generate, mpi)
+            }
+        }
+    }
+}
+
+impl<'tcx> MovePathLookup<'tcx> {
+    // Unlike the builder `fn move_path_for` below, this lookup
+    // alternative will *not* create a MovePath on the fly for an
+    // unknown l-value; it will simply panic.
+    pub fn find(&self, lval: &Lvalue<'tcx>) -> MovePathIndex {
+        match *lval {
+            Lvalue::Var(var_idx) => self.vars[var_idx as usize].unwrap(),
+            Lvalue::Temp(temp_idx) => self.temps[temp_idx as usize].unwrap(),
+            Lvalue::Arg(arg_idx) => self.args[arg_idx as usize].unwrap(),
+            Lvalue::Static(ref _def_id) => self.statics.unwrap(),
+            Lvalue::ReturnPointer => self.return_ptr.unwrap(),
+            Lvalue::Projection(ref proj) => {
+                let base_index = self.find(&proj.base);
+                self.projections[base_index.idx()][&proj.elem.lift()]
+            }
+        }
+    }
+}
+
+impl<'a, 'tcx> MovePathDataBuilder<'a, 'tcx> {
+    fn lookup(&mut self, lval: &Lvalue<'tcx>) -> Lookup<MovePathIndex> {
+        let proj = match *lval {
+            Lvalue::Var(var_idx) =>
+                return self.rev_lookup.lookup_var(var_idx),
+            Lvalue::Temp(temp_idx) =>
+                return self.rev_lookup.lookup_temp(temp_idx),
+            Lvalue::Arg(arg_idx) =>
+                return self.rev_lookup.lookup_arg(arg_idx),
+            Lvalue::Static(_def_id) =>
+                return self.rev_lookup.lookup_static(),
+            Lvalue::ReturnPointer =>
+                return self.rev_lookup.lookup_return_pointer(),
+            Lvalue::Projection(ref proj) => {
+                proj
+            }
+        };
+
+        let base_index = self.move_path_for(&proj.base);
+        self.rev_lookup.lookup_proj(proj, base_index)
+    }
+
+    fn move_path_for(&mut self, lval: &Lvalue<'tcx>) -> MovePathIndex {
+        let lookup: Lookup<MovePathIndex> = self.lookup(lval);
+
+        // `lookup` is either the previously assigned index or a
+        // newly-allocated one.
+        debug_assert!(lookup.idx() <= self.pre_move_paths.len());
+
+        if let Lookup(LookupKind::Generate, mpi) = lookup {
+            let parent;
+            let sibling;
+            // tracks whether content is Some non-static; statics map to None.
+            let content: Option<&Lvalue<'tcx>>;
+
+            match *lval {
+                Lvalue::Static(_) => {
+                    content = None;
+                    sibling = None;
+                    parent = None;
+                }
+
+                Lvalue::Var(_) | Lvalue::Temp(_) | Lvalue::Arg(_) |
+                Lvalue::ReturnPointer => {
+                    content = Some(lval);
+                    sibling = None;
+                    parent = None;
+                }
+                Lvalue::Projection(ref proj) => {
+                    content = Some(lval);
+
+                    // Here, install new MovePath as new first_child.
+
+                    // Note: `parent` previously allocated (Projection
+                    // case of match above established this).
+                    let idx = self.move_path_for(&proj.base);
+                    parent = Some(idx);
+
+                    let parent_move_path = &mut self.pre_move_paths[idx.idx()];
+
+                    // At last: Swap in the new first_child.
+                    sibling = parent_move_path.first_child.get();
+                    parent_move_path.first_child.set(Some(mpi));
+                }
+            };
+
+            let content = match content {
+                Some(lval) => MovePathContent::Lvalue(lval.clone()),
+                None => MovePathContent::Static,
+            };
+
+            let move_path = PreMovePath {
+                next_sibling: sibling,
+                parent: parent,
+                content: content,
+                first_child: Cell::new(None),
+            };
+
+            self.pre_move_paths.push(move_path);
+        }
+
+        return lookup.1;
+    }
+}
+
+impl<'tcx> MoveData<'tcx> {
+    pub fn gather_moves(mir: &Mir<'tcx>, tcx: &ty::TyCtxt<'tcx>) -> Self {
+        gather_moves(mir, tcx)
+    }
+}
+
+#[derive(Debug)]
+enum StmtKind {
+    Use, Repeat, Cast, BinaryOp, UnaryOp, Box,
+    Aggregate, Drop, CallFn, CallArg, Return,
+}
+
+fn gather_moves<'tcx>(mir: &Mir<'tcx>, tcx: &ty::TyCtxt<'tcx>) -> MoveData<'tcx> {
+    use self::StmtKind as SK;
+
+    let bbs = mir.all_basic_blocks();
+    let mut moves = Vec::with_capacity(bbs.len());
+    let mut loc_map: Vec<_> = iter::repeat(Vec::new()).take(bbs.len()).collect();
+    let mut path_map = Vec::new();
+
+    // this is mutable only because we will move it to and fro' the
+    // BlockContexts constructed on each iteration. (Moving is more
+    // straight-forward than mutable borrows in this instance.)
+    let mut builder = MovePathDataBuilder {
+        mir: mir,
+        pre_move_paths: Vec::new(),
+        rev_lookup: MovePathLookup::new(),
+    };
+
+    for bb in bbs {
+        let loc_map_bb = &mut loc_map[bb.index()];
+        let bb_data = mir.basic_block_data(bb);
+
+        debug_assert!(loc_map_bb.len() == 0);
+        let len = bb_data.statements.len();
+        loc_map_bb.fill_to(len);
+        debug_assert!(loc_map_bb.len() == len + 1);
+
+        let mut bb_ctxt = BlockContext {
+            tcx: tcx,
+            moves: &mut moves,
+            builder: builder,
+            path_map: &mut path_map,
+            loc_map_bb: loc_map_bb,
+        };
+
+        for (i, stmt) in bb_data.statements.iter().enumerate() {
+            let source = Location { block: bb, index: i };
+            match stmt.kind {
+                StatementKind::Assign(ref lval, ref rval) => {
+                    // ensure MovePath created for `lval`.
+                    bb_ctxt.builder.move_path_for(lval);
+
+                    match *rval {
+                        Rvalue::Use(ref operand) => {
+                            bb_ctxt.on_operand(SK::Use, operand, source)
+                        }
+                        Rvalue::Repeat(ref operand, ref _const) =>
+                            bb_ctxt.on_operand(SK::Repeat, operand, source),
+                        Rvalue::Cast(ref _kind, ref operand, ref _ty) =>
+                            bb_ctxt.on_operand(SK::Cast, operand, source),
+                        Rvalue::BinaryOp(ref _binop, ref operand1, ref operand2) => {
+                            bb_ctxt.on_operand(SK::BinaryOp, operand1, source);
+                            bb_ctxt.on_operand(SK::BinaryOp, operand2, source);
+                        }
+                        Rvalue::UnaryOp(ref _unop, ref operand) => {
+                            bb_ctxt.on_operand(SK::UnaryOp, operand, source);
+                        }
+                        Rvalue::Box(ref _ty) => {
+                            // this is creating uninitialized
+                            // memory that needs to be initialized.
+                            let deref_lval = Lvalue::Projection(Box::new( repr::Projection {
+                                base: lval.clone(),
+                                elem: repr::ProjectionElem::Deref,
+                            }));
+                            bb_ctxt.on_move_out_lval(SK::Box, &deref_lval, source);
+                        }
+                        Rvalue::Aggregate(ref _kind, ref operands) => {
+                            for operand in operands {
+                                bb_ctxt.on_operand(SK::Aggregate, operand, source);
+                            }
+                        }
+                        Rvalue::Ref(..) |
+                        Rvalue::Len(..) |
+                        Rvalue::InlineAsm { .. } => {}
+
+                        Rvalue::Slice {..} => {
+                            bb_ctxt.tcx.sess.bug("cannot move out of slice");
+                        }
+                    }
+                }
+            }
+        }
+
+        if let Some(ref term) = bb_data.terminator {
+            match *term {
+                Terminator::Goto { target: _ } | Terminator::Resume => { }
+
+                Terminator::Return => {
+                    let source = Location { block: bb,
+                                            index: bb_data.statements.len() };
+                    let lval = &Lvalue::ReturnPointer.deref();
+                    bb_ctxt.on_move_out_lval(SK::Return, lval, source);
+                }
+
+                Terminator::If { ref cond, targets: _ } => {
+                    // The `cond` is always of (copyable) type `bool`,
+                    // so there will never be anything to move.
+                    let _ = cond;
+                }
+
+                Terminator::SwitchInt { switch_ty: _, values: _, targets: _, ref discr } |
+                Terminator::Switch { adt_def: _, targets: _, ref discr } => {
+                    // The `discr` is not consumed; that is instead
+                    // encoded on specific match arms (and for
+                    // SwitchInt`, it is always a copyable integer
+                    // type anyway).
+                    let _ = discr;
+                }
+
+                Terminator::Drop { value: ref lval, target: _, unwind: _ } => {
+                    let source = Location { block: bb,
+                                            index: bb_data.statements.len() };
+                    bb_ctxt.on_move_out_lval(SK::Drop, lval, source);
+                }
+
+                Terminator::Call { ref func, ref args, ref destination, cleanup: _ } => {
+                    let source = Location { block: bb,
+                                            index: bb_data.statements.len() };
+                    bb_ctxt.on_operand(SK::CallFn, func, source);
+                    for arg in args {
+                        bb_ctxt.on_operand(SK::CallArg, arg, source);
+                    }
+                    if let Some((ref destination, _bb)) = *destination {
+                        // Create MovePath for `destination`, then
+                        // discard returned index.
+                        bb_ctxt.builder.move_path_for(destination);
+                    }
+                }
+            }
+        }
+
+        builder = bb_ctxt.builder;
+    }
+
+    // At this point, we may have created some MovePaths that do not
+    // have corresponding entries in the path map.
+    //
+    // (For example, creating the path `a.b.c` may, as a side-effect,
+    // create a path for the parent path `a.b`.)
+    //
+    // All such paths were not referenced ...
+    //
+    // well you know, lets actually try just asserting that the path map *is* complete.
+    assert_eq!(path_map.len(), builder.pre_move_paths.len());
+    path_map.fill_to(builder.pre_move_paths.len() - 1);
+
+    let pre_move_paths = builder.pre_move_paths;
+    let move_paths: Vec<_> = pre_move_paths.into_iter()
+        .map(|p| p.into_move_path())
+        .collect();
+
+    debug!("{}", {
+        let mut seen: Vec<_> = move_paths.iter().map(|_| false).collect();
+        for (j, &MoveOut { ref path, ref source }) in moves.iter().enumerate() {
+            debug!("MovePathData moves[{}]: MoveOut {{ path: {:?} = {:?}, source: {:?} }}",
+                   j, path, move_paths[path.idx()], source);
+            seen[path.idx()] = true;
+        }
+        for (j, path) in move_paths.iter().enumerate() {
+            if !seen[j] {
+                debug!("MovePathData move_paths[{}]: {:?}", j, path);
+            }
+        }
+        "done dumping MovePathData"
+    });
+
+    MoveData {
+        move_paths: MovePathData { move_paths: move_paths, },
+        moves: moves,
+        loc_map: LocMap { map: loc_map },
+        path_map: PathMap { map: path_map },
+        rev_lookup: builder.rev_lookup,
+    }
+}
+
+struct BlockContext<'b, 'a: 'b, 'tcx: 'a> {
+    tcx: &'b ty::TyCtxt<'tcx>,
+    moves: &'b mut Vec<MoveOut>,
+    builder: MovePathDataBuilder<'a, 'tcx>,
+    path_map: &'b mut Vec<Vec<MoveOutIndex>>,
+    loc_map_bb: &'b mut Vec<Vec<MoveOutIndex>>,
+}
+
+impl<'b, 'a: 'b, 'tcx: 'a> BlockContext<'b, 'a, 'tcx> {
+    fn on_move_out_lval(&mut self,
+                        stmt_kind: StmtKind,
+                        lval: &repr::Lvalue<'tcx>,
+                        source: Location) {
+        let tcx = self.tcx;
+        let lval_ty = self.builder.mir.lvalue_ty(tcx, lval);
+
+        // FIXME: does lvalue_ty ever return TyError, or is it
+        // guaranteed to always return non-Infer/non-Error values?
+
+        // This code is just trying to avoid creating a MoveOut
+        // entry for values that do not need move semantics.
+        //
+        // type_contents is imprecise (may claim needs drop for
+        // types that in fact have no destructor). But that is
+        // still usable for our purposes here.
+        let consumed = lval_ty.to_ty(tcx).type_contents(tcx).needs_drop(tcx);
+
+        if !consumed {
+            debug!("ctxt: {:?} no consume of lval: {:?} of type {:?}",
+                   stmt_kind, lval, lval_ty);
+            return;
+        }
+        let i = source.index;
+        let index = MoveOutIndex::new(self.moves.len());
+
+        let path = self.builder.move_path_for(lval);
+        self.moves.push(MoveOut { path: path, source: source.clone() });
+        self.path_map.fill_to(path.idx());
+
+        debug!("ctxt: {:?} add consume of lval: {:?} \
+                at index: {:?} \
+                to path_map for path: {:?} and \
+                to loc_map for loc: {:?}",
+               stmt_kind, lval, index, path, source);
+
+        debug_assert!(path.idx() < self.path_map.len());
+        // this is actually a questionable assert; at the very
+        // least, incorrect input code can probably cause it to
+        // fire.
+        assert!(self.path_map[path.idx()].iter().find(|idx| **idx == index).is_none());
+        self.path_map[path.idx()].push(index);
+
+        debug_assert!(i < self.loc_map_bb.len());
+        debug_assert!(self.loc_map_bb[i].iter().find(|idx| **idx == index).is_none());
+        self.loc_map_bb[i].push(index);
+    }
+
+    fn on_operand(&mut self, stmt_kind: StmtKind, operand: &repr::Operand<'tcx>, source: Location) {
+        match *operand {
+            repr::Operand::Constant(..) => {} // not-a-move
+            repr::Operand::Consume(ref lval) => { // a move
+                self.on_move_out_lval(stmt_kind, lval, source);
+            }
+        }
+    }
+}
+
+impl<'tcx> BitDenotation for MoveData<'tcx>{
+    type Bit = MoveOut;
+    fn bits_per_block(&self) -> usize {
+        self.moves.len()
+    }
+    fn interpret(&self, idx: usize) -> &Self::Bit {
+        &self.moves[idx]
+    }
+}
diff --git a/src/librustc_borrowck/borrowck/mir/graphviz.rs b/src/librustc_borrowck/borrowck/mir/graphviz.rs
new file mode 100644
index 00000000000..b81ef186a4f
--- /dev/null
+++ b/src/librustc_borrowck/borrowck/mir/graphviz.rs
@@ -0,0 +1,232 @@
+// Copyright 2012-2016 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.
+
+//! Hook into libgraphviz for rendering dataflow graphs for MIR.
+
+use rustc::mir::repr::{BasicBlock, Mir};
+
+use dot;
+use dot::IntoCow;
+
+use std::fs::File;
+use std::io;
+use std::io::prelude::*;
+
+use super::MirBorrowckCtxt;
+use bitslice::bits_to_string;
+use super::gather_moves::MoveOut;
+
+struct Graph<'c, 'b:'c, 'a:'b, 'tcx:'a> { mbcx: &'c MirBorrowckCtxt<'b, 'a, 'tcx>,
+                                          context: &'b str }
+
+pub fn print_borrowck_graph_to(mbcx: &MirBorrowckCtxt,
+                               context: &str,
+                               path: &str) -> io::Result<()> {
+    let g = Graph { mbcx: mbcx, context: context };
+    let mut v = Vec::new();
+    try!(dot::render(&g, &mut v));
+    println!("print_borrowck_graph_to path: {} context: {} node_id: {}",
+             path, context, mbcx.node_id);
+    File::create(path).and_then(|mut f| f.write_all(&v))
+}
+
+pub type Node = BasicBlock;
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct Edge { source: BasicBlock, index: usize }
+
+fn outgoing(mir: &Mir, bb: BasicBlock) -> Vec<Edge> {
+    let succ_len = mir.basic_block_data(bb).terminator().successors().len();
+    (0..succ_len).map(|index| Edge { source: bb, index: index}).collect()
+}
+
+impl<'c, 'b:'c, 'a:'b, 'tcx:'a> dot::Labeller<'c> for Graph<'c,'b,'a,'tcx> {
+    type Node = Node;
+    type Edge = Edge;
+    fn graph_id(&self) -> dot::Id {
+        dot::Id::new(format!("graph_for_node_{}_{}",
+                             self.mbcx.node_id,
+                             self.context))
+            .unwrap()
+    }
+
+    fn node_id(&self, n: &Node) -> dot::Id {
+        dot::Id::new(format!("bb_{}", n.index()))
+            .unwrap()
+    }
+
+    fn node_label(&self, n: &Node) -> dot::LabelText {
+        // A standard MIR label, as generated by write_node_label, is
+        // presented in a single column in a table.
+        //
+        // The code below does a bunch of formatting work to format a
+        // node (i.e. MIR basic-block) label with extra
+        // dataflow-enriched information.  In particular, the goal is
+        // to add extra columns that present the three dataflow
+        // bitvectors, and the data those bitvectors represent.
+        //
+        // It presents it in the following format (where I am
+        // presenting the table rendering via ASCII art, one line per
+        // row of the table, and a chunk size of 3 rather than 5):
+        //
+        // ------  -----------------------  ------------  --------------------
+        //                    [e1, e3, e4]
+        //             [e8, e9] "= ENTRY:"  <ENTRY-BITS>
+        // ------  -----------------------  ------------  --------------------
+        // Left
+        // Most
+        // Column
+        // Is
+        // Just
+        // Normal
+        // Series
+        // Of
+        // MIR
+        // Stmts
+        // ------  -----------------------  ------------  --------------------
+        //           [g1, g4, g5] "= GEN:"  <GEN-BITS>
+        // ------  -----------------------  ------------  --------------------
+        //                         "KILL:"  <KILL-BITS>   "=" [k1, k3, k8]
+        //                                                [k9]
+        // ------  -----------------------  ------------  --------------------
+        //
+        // (In addition, the added dataflow is rendered with a colored
+        // background just so it will stand out compared to the
+        // statements.)
+        let mut v = Vec::new();
+        let i = n.index();
+        let chunk_size = 5;
+        const BG_FLOWCONTENT: &'static str = r#"bgcolor="pink""#;
+        const ALIGN_RIGHT: &'static str = r#"align="right""#;
+        const FACE_MONOSPACE: &'static str = r#"FACE="Courier""#;
+        fn chunked_present_left<W:io::Write>(w: &mut W,
+                                             interpreted: &[&MoveOut],
+                                             chunk_size: usize)
+                                             -> io::Result<()>
+        {
+            // This function may emit a sequence of <tr>'s, but it
+            // always finishes with an (unfinished)
+            // <tr><td></td><td>
+            //
+            // Thus, after being called, one should finish both the
+            // pending <td> as well as the <tr> itself.
+            let mut seen_one = false;
+            for c in interpreted.chunks(chunk_size) {
+                if seen_one {
+                    // if not the first row, finish off the previous row
+                    try!(write!(w, "</td><td></td><td></td></tr>"));
+                }
+                try!(write!(w, "<tr><td></td><td {bg} {align}>{objs:?}",
+                            bg = BG_FLOWCONTENT,
+                            align = ALIGN_RIGHT,
+                            objs = c));
+                seen_one = true;
+            }
+            if !seen_one {
+                try!(write!(w, "<tr><td></td><td {bg} {align}>[]",
+                            bg = BG_FLOWCONTENT,
+                            align = ALIGN_RIGHT));
+            }
+            Ok(())
+        }
+        ::rustc_mir::graphviz::write_node_label(
+            *n, self.mbcx.mir, &mut v, 4,
+            |w| {
+                let flow = &self.mbcx.flow_state;
+                let entry = flow.interpret_set(flow.sets.on_entry_set_for(i));
+                try!(chunked_present_left(w, &entry[..], chunk_size));
+                write!(w, "= ENTRY:</td><td {bg}><FONT {face}>{entrybits:?}</FONT></td>\
+                                        <td></td></tr>",
+                       bg = BG_FLOWCONTENT,
+                       face = FACE_MONOSPACE,
+                       entrybits=bits_to_string(flow.sets.on_entry_set_for(i),
+                                                flow.sets.bytes_per_block()))
+            },
+            |w| {
+                let flow = &self.mbcx.flow_state;
+                let gen = flow.interpret_set( flow.sets.gen_set_for(i));
+                let kill = flow.interpret_set(flow.sets.kill_set_for(i));
+                try!(chunked_present_left(w, &gen[..], chunk_size));
+                try!(write!(w, " = GEN:</td><td {bg}><FONT {face}>{genbits:?}</FONT></td>\
+                                            <td></td></tr>",
+                            bg = BG_FLOWCONTENT,
+                            face = FACE_MONOSPACE,
+                            genbits=bits_to_string( flow.sets.gen_set_for(i),
+                                                    flow.sets.bytes_per_block())));
+                try!(write!(w, "<tr><td></td><td {bg} {align}>KILL:</td>\
+                                             <td {bg}><FONT {face}>{killbits:?}</FONT></td>",
+                            bg = BG_FLOWCONTENT,
+                            align = ALIGN_RIGHT,
+                            face = FACE_MONOSPACE,
+                            killbits=bits_to_string(flow.sets.kill_set_for(i),
+                                                    flow.sets.bytes_per_block())));
+
+                // (chunked_present_right)
+                let mut seen_one = false;
+                for k in kill.chunks(chunk_size) {
+                    if !seen_one {
+                        // continuation of row; this is fourth <td>
+                        try!(write!(w, "<td {bg}>= {kill:?}</td></tr>",
+                                    bg = BG_FLOWCONTENT,
+                                    kill=k));
+                    } else {
+                        // new row, with indent of three <td>'s
+                        try!(write!(w, "<tr><td></td><td></td><td></td><td {bg}>{kill:?}</td></tr>",
+                                    bg = BG_FLOWCONTENT,
+                                    kill=k));
+                    }
+                    seen_one = true;
+                }
+                if !seen_one {
+                    try!(write!(w, "<td {bg}>= []</td></tr>",
+                                bg = BG_FLOWCONTENT));
+                }
+
+                Ok(())
+            })
+            .unwrap();
+        dot::LabelText::html(String::from_utf8(v).unwrap())
+    }
+
+    fn node_shape(&self, _n: &Node) -> Option<dot::LabelText> {
+        Some(dot::LabelText::label("none"))
+    }
+}
+
+impl<'c, 'b:'c, 'a:'b, 'tcx:'a> dot::GraphWalk<'c> for Graph<'c,'b,'a,'tcx> {
+    type Node = Node;
+    type Edge = Edge;
+    fn nodes(&self) -> dot::Nodes<Node> {
+        self.mbcx.mir.all_basic_blocks().into_cow()
+    }
+
+    fn edges(&self) -> dot::Edges<Edge> {
+        let mir = self.mbcx.mir;
+        let blocks = self.mbcx.mir.all_basic_blocks();
+        // base initial capacity on assumption every block has at
+        // least one outgoing edge (Which should be true for all
+        // blocks but one, the exit-block).
+        let mut edges = Vec::with_capacity(blocks.len());
+        for bb in blocks {
+            let outgoing = outgoing(mir, bb);
+            edges.extend(outgoing.into_iter());
+        }
+        edges.into_cow()
+    }
+
+    fn source(&self, edge: &Edge) -> Node {
+        edge.source
+    }
+
+    fn target(&self, edge: &Edge) -> Node {
+        let mir = self.mbcx.mir;
+        mir.basic_block_data(edge.source).terminator().successors()[edge.index]
+    }
+}
diff --git a/src/librustc_borrowck/borrowck/mir/mod.rs b/src/librustc_borrowck/borrowck/mir/mod.rs
new file mode 100644
index 00000000000..d1335811858
--- /dev/null
+++ b/src/librustc_borrowck/borrowck/mir/mod.rs
@@ -0,0 +1,91 @@
+// Copyright 2012-2016 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 borrowck::BorrowckCtxt;
+
+use syntax::ast;
+use syntax::codemap::Span;
+
+use rustc_front::hir;
+use rustc_front::intravisit::{FnKind};
+
+use rustc::mir::repr::{BasicBlock, BasicBlockData, Mir, Statement, Terminator};
+
+mod abs_domain;
+mod dataflow;
+mod gather_moves;
+mod graphviz;
+
+use self::dataflow::{Dataflow, DataflowState};
+use self::gather_moves::{MoveData};
+
+pub fn borrowck_mir<'b, 'a: 'b, 'tcx: 'a>(
+    bcx: &'b mut BorrowckCtxt<'a, 'tcx>,
+    fk: FnKind,
+    _decl: &hir::FnDecl,
+    mir: &'a Mir<'tcx>,
+    body: &hir::Block,
+    _sp: Span,
+    id: ast::NodeId,
+    attributes: &[ast::Attribute]) {
+    match fk {
+        FnKind::ItemFn(name, _, _, _, _, _, _) |
+        FnKind::Method(name, _, _, _) => {
+            debug!("borrowck_mir({}) UNIMPLEMENTED", name);
+        }
+        FnKind::Closure(_) => {
+            debug!("borrowck_mir closure (body.id={}) UNIMPLEMENTED", body.id);
+        }
+    }
+
+    let mut mbcx = MirBorrowckCtxt {
+        bcx: bcx,
+        mir: mir,
+        node_id: id,
+        attributes: attributes,
+        flow_state: DataflowState::new_move_analysis(mir, bcx.tcx),
+    };
+
+    for bb in mir.all_basic_blocks() {
+        mbcx.process_basic_block(bb);
+    }
+
+    mbcx.dataflow();
+
+    debug!("borrowck_mir done");
+}
+
+pub struct MirBorrowckCtxt<'b, 'a: 'b, 'tcx: 'a> {
+    bcx: &'b mut BorrowckCtxt<'a, 'tcx>,
+    mir: &'b Mir<'tcx>,
+    node_id: ast::NodeId,
+    attributes: &'b [ast::Attribute],
+    flow_state: DataflowState<MoveData<'tcx>>,
+}
+
+impl<'b, 'a: 'b, 'tcx: 'a> MirBorrowckCtxt<'b, 'a, 'tcx> {
+    fn process_basic_block(&mut self, bb: BasicBlock) {
+        let &BasicBlockData { ref statements, ref terminator, is_cleanup: _ } =
+            self.mir.basic_block_data(bb);
+        for stmt in statements {
+            self.process_statement(bb, stmt);
+        }
+
+        self.process_terminator(bb, terminator);
+    }
+
+    fn process_statement(&mut self, bb: BasicBlock, stmt: &Statement<'tcx>) {
+        debug!("MirBorrowckCtxt::process_statement({:?}, {:?}", bb, stmt);
+    }
+
+    fn process_terminator(&mut self, bb: BasicBlock, term: &Option<Terminator<'tcx>>) {
+        debug!("MirBorrowckCtxt::process_terminator({:?}, {:?})", bb, term);
+    }
+}
diff --git a/src/librustc_borrowck/borrowck/mod.rs b/src/librustc_borrowck/borrowck/mod.rs
index cab8125a61b..bb2fe7acb95 100644
--- a/src/librustc_borrowck/borrowck/mod.rs
+++ b/src/librustc_borrowck/borrowck/mod.rs
@@ -40,6 +40,7 @@ use std::fmt;
 use std::mem;
 use std::rc::Rc;
 use syntax::ast;
+use syntax::attr::AttrMetaMethods;
 use syntax::codemap::Span;
 use syntax::errors::DiagnosticBuilder;
 
@@ -49,12 +50,16 @@ use rustc_front::intravisit;
 use rustc_front::intravisit::{Visitor, FnKind};
 use rustc_front::util as hir_util;
 
+use rustc::mir::mir_map::MirMap;
+
 pub mod check_loans;
 
 pub mod gather_loans;
 
 pub mod move_data;
 
+mod mir;
+
 #[derive(Clone, Copy)]
 pub struct LoanDataFlowOperator;
 
@@ -66,15 +71,13 @@ impl<'a, 'tcx, 'v> Visitor<'v> for BorrowckCtxt<'a, 'tcx> {
         match fk {
             FnKind::ItemFn(..) |
             FnKind::Method(..) => {
-                let new_free_region_map = self.tcx.free_region_map(id);
-                let old_free_region_map =
-                    mem::replace(&mut self.free_region_map, new_free_region_map);
-                borrowck_fn(self, fk, fd, b, s, id);
-                self.free_region_map = old_free_region_map;
+                self.with_temp_region_map(id, |this| {
+                    borrowck_fn(this, fk, fd, b, s, id, fk.attrs())
+                });
             }
 
-            FnKind::Closure => {
-                borrowck_fn(self, fk, fd, b, s, id);
+            FnKind::Closure(..) => {
+                borrowck_fn(self, fk, fd, b, s, id, fk.attrs());
             }
         }
     }
@@ -98,9 +101,10 @@ impl<'a, 'tcx, 'v> Visitor<'v> for BorrowckCtxt<'a, 'tcx> {
     }
 }
 
-pub fn check_crate(tcx: &TyCtxt) {
+pub fn check_crate<'tcx>(tcx: &TyCtxt<'tcx>, mir_map: &MirMap<'tcx>) {
     let mut bccx = BorrowckCtxt {
         tcx: tcx,
+        mir_map: Some(mir_map),
         free_region_map: FreeRegionMap::new(),
         stats: BorrowStats {
             loaned_paths_same: 0,
@@ -159,8 +163,17 @@ fn borrowck_fn(this: &mut BorrowckCtxt,
                decl: &hir::FnDecl,
                body: &hir::Block,
                sp: Span,
-               id: ast::NodeId) {
+               id: ast::NodeId,
+               attributes: &[ast::Attribute]) {
     debug!("borrowck_fn(id={})", id);
+
+    if attributes.iter().any(|item| item.check_name("rustc_mir_borrowck")) {
+        let mir = this.mir_map.unwrap().map.get(&id).unwrap();
+        this.with_temp_region_map(id, |this| {
+            mir::borrowck_mir(this, fk, decl, mir, body, sp, id, attributes)
+        });
+    }
+
     let cfg = cfg::CFG::new(this.tcx, body);
     let AnalysisData { all_loans,
                        loans: loan_dfcx,
@@ -233,6 +246,7 @@ fn build_borrowck_dataflow_data<'a, 'tcx>(this: &mut BorrowckCtxt<'a, 'tcx>,
 /// the `BorrowckCtxt` itself , e.g. the flowgraph visualizer.
 pub fn build_borrowck_dataflow_data_for_fn<'a, 'tcx>(
     tcx: &'a TyCtxt<'tcx>,
+    mir_map: Option<&'a MirMap<'tcx>>,
     fn_parts: FnParts<'a>,
     cfg: &cfg::CFG)
     -> (BorrowckCtxt<'a, 'tcx>, AnalysisData<'a, 'tcx>)
@@ -240,6 +254,7 @@ pub fn build_borrowck_dataflow_data_for_fn<'a, 'tcx>(
 
     let mut bccx = BorrowckCtxt {
         tcx: tcx,
+        mir_map: mir_map,
         free_region_map: FreeRegionMap::new(),
         stats: BorrowStats {
             loaned_paths_same: 0,
@@ -279,9 +294,13 @@ pub struct BorrowckCtxt<'a, 'tcx: 'a> {
     free_region_map: FreeRegionMap,
 
     // Statistics:
-    stats: BorrowStats
+    stats: BorrowStats,
+
+    // NodeId to MIR mapping (for methods that carry the #[rustc_mir] attribute).
+    mir_map: Option<&'a MirMap<'tcx>>,
 }
 
+#[derive(Clone)]
 struct BorrowStats {
     loaned_paths_same: usize,
     loaned_paths_imm: usize,
@@ -574,6 +593,15 @@ pub enum MovedValueUseKind {
 // Misc
 
 impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
+    fn with_temp_region_map<F>(&mut self, id: ast::NodeId, f: F)
+        where F: for <'b> FnOnce(&'b mut BorrowckCtxt<'a, 'tcx>)
+    {
+        let new_free_region_map = self.tcx.free_region_map(id);
+        let old_free_region_map = mem::replace(&mut self.free_region_map, new_free_region_map);
+        f(self);
+        self.free_region_map = old_free_region_map;
+    }
+
     pub fn is_subregion_of(&self, r_sub: ty::Region, r_sup: ty::Region)
                            -> bool
     {
diff --git a/src/librustc_borrowck/graphviz.rs b/src/librustc_borrowck/graphviz.rs
index 7a5491cdbe7..fd23772bcda 100644
--- a/src/librustc_borrowck/graphviz.rs
+++ b/src/librustc_borrowck/graphviz.rs
@@ -129,7 +129,9 @@ impl<'a, 'tcx> DataflowLabeller<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> dot::Labeller<'a, Node<'a>, Edge<'a>> for DataflowLabeller<'a, 'tcx> {
+impl<'a, 'tcx> dot::Labeller<'a> for DataflowLabeller<'a, 'tcx> {
+    type Node = Node<'a>;
+    type Edge = Edge<'a>;
     fn graph_id(&'a self) -> dot::Id<'a> { self.inner.graph_id() }
     fn node_id(&'a self, n: &Node<'a>) -> dot::Id<'a> { self.inner.node_id(n) }
     fn node_label(&'a self, n: &Node<'a>) -> dot::LabelText<'a> {
@@ -143,7 +145,9 @@ impl<'a, 'tcx> dot::Labeller<'a, Node<'a>, Edge<'a>> for DataflowLabeller<'a, 't
     fn edge_label(&'a self, e: &Edge<'a>) -> dot::LabelText<'a> { self.inner.edge_label(e) }
 }
 
-impl<'a, 'tcx> dot::GraphWalk<'a, Node<'a>, Edge<'a>> for DataflowLabeller<'a, 'tcx> {
+impl<'a, 'tcx> dot::GraphWalk<'a> for DataflowLabeller<'a, 'tcx> {
+    type Node = Node<'a>;
+    type Edge = Edge<'a>;
     fn nodes(&'a self) -> dot::Nodes<'a, Node<'a>> { self.inner.nodes() }
     fn edges(&'a self) -> dot::Edges<'a, Edge<'a>> { self.inner.edges() }
     fn source(&'a self, edge: &Edge<'a>) -> Node<'a> { self.inner.source(edge) }
diff --git a/src/librustc_borrowck/lib.rs b/src/librustc_borrowck/lib.rs
index e7f5fddc7bb..65e9b792241 100644
--- a/src/librustc_borrowck/lib.rs
+++ b/src/librustc_borrowck/lib.rs
@@ -23,7 +23,8 @@
 #![feature(rustc_diagnostic_macros)]
 #![feature(rustc_private)]
 #![feature(staged_api)]
-
+#![feature(associated_consts)]
+#![feature(nonzero)]
 #[macro_use] extern crate log;
 #[macro_use] extern crate syntax;
 
@@ -32,6 +33,8 @@
 extern crate graphviz as dot;
 extern crate rustc;
 extern crate rustc_front;
+extern crate rustc_mir;
+extern crate core; // for NonZero
 
 pub use borrowck::check_crate;
 pub use borrowck::build_borrowck_dataflow_data_for_fn;
@@ -42,6 +45,7 @@ pub use borrowck::{AnalysisData, BorrowckCtxt};
 pub mod diagnostics;
 
 mod borrowck;
+mod bitslice;
 
 pub mod graphviz;
 
diff --git a/src/librustc_driver/driver.rs b/src/librustc_driver/driver.rs
index 8dac25cc0cb..c39d0d7587f 100644
--- a/src/librustc_driver/driver.rs
+++ b/src/librustc_driver/driver.rs
@@ -880,7 +880,7 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
 
         time(time_passes,
              "borrow checking",
-             || borrowck::check_crate(tcx));
+             || borrowck::check_crate(tcx, &mir_map));
 
         // Avoid overwhelming user with errors if type checking failed.
         // I'm not sure how helpful this is, to be honest, but it avoids
diff --git a/src/librustc_driver/pretty.rs b/src/librustc_driver/pretty.rs
index 4792fa72831..5134278de21 100644
--- a/src/librustc_driver/pretty.rs
+++ b/src/librustc_driver/pretty.rs
@@ -56,6 +56,8 @@ use rustc_front::hir;
 use rustc_front::lowering::{lower_crate, LoweringContext};
 use rustc_front::print::pprust as pprust_hir;
 
+use rustc::mir::mir_map::MirMap;
+
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub enum PpSourceMode {
     PpmNormal,
@@ -875,9 +877,10 @@ pub fn pretty_print_input(sess: Session,
                                                                      &arenas,
                                                                      &id,
                                                                      resolve::MakeGlobMap::No,
-                                                                     |tcx, _, _, _| {
+                                                                     |tcx, mir_map, _, _| {
                         print_flowgraph(variants,
                                         tcx,
+                                        mir_map.as_ref(),
                                         code,
                                         mode,
                                         out)
@@ -911,12 +914,13 @@ pub fn pretty_print_input(sess: Session,
     }
 }
 
-fn print_flowgraph<W: Write>(variants: Vec<borrowck_dot::Variant>,
-                             tcx: &TyCtxt,
-                             code: blocks::Code,
-                             mode: PpFlowGraphMode,
-                             mut out: W)
-                             -> io::Result<()> {
+fn print_flowgraph<'tcx, W: Write>(variants: Vec<borrowck_dot::Variant>,
+                                   tcx: &TyCtxt<'tcx>,
+                                   mir_map: Option<&MirMap<'tcx>>,
+                                   code: blocks::Code,
+                                   mode: PpFlowGraphMode,
+                                   mut out: W)
+                                   -> io::Result<()> {
     let cfg = match code {
         blocks::BlockCode(block) => cfg::CFG::new(tcx, &block),
         blocks::FnLikeCode(fn_like) => cfg::CFG::new(tcx, &fn_like.body()),
@@ -942,6 +946,7 @@ fn print_flowgraph<W: Write>(variants: Vec<borrowck_dot::Variant>,
         blocks::FnLikeCode(fn_like) => {
             let (bccx, analysis_data) =
                 borrowck::build_borrowck_dataflow_data_for_fn(tcx,
+                                                              mir_map,
                                                               fn_like.to_fn_parts(),
                                                               &cfg);
 
diff --git a/src/librustc_front/intravisit.rs b/src/librustc_front/intravisit.rs
index e031dfc5b16..be1cc528d88 100644
--- a/src/librustc_front/intravisit.rs
+++ b/src/librustc_front/intravisit.rs
@@ -27,19 +27,30 @@
 
 use syntax::abi::Abi;
 use syntax::ast::{NodeId, CRATE_NODE_ID, Name, Attribute};
+use syntax::attr::ThinAttributesExt;
 use syntax::codemap::Span;
 use hir::*;
 
 #[derive(Copy, Clone, PartialEq, Eq)]
 pub enum FnKind<'a> {
     /// fn foo() or extern "Abi" fn foo()
-    ItemFn(Name, &'a Generics, Unsafety, Constness, Abi, Visibility),
+    ItemFn(Name, &'a Generics, Unsafety, Constness, Abi, Visibility, &'a [Attribute]),
 
     /// fn foo(&self)
-    Method(Name, &'a MethodSig, Option<Visibility>),
+    Method(Name, &'a MethodSig, Option<Visibility>, &'a [Attribute]),
 
     /// |x, y| {}
-    Closure,
+    Closure(&'a [Attribute]),
+}
+
+impl<'a> FnKind<'a> {
+    pub fn attrs(&self) -> &'a [Attribute] {
+        match *self {
+            FnKind::ItemFn(_, _, _, _, _, _, attrs) => attrs,
+            FnKind::Method(_, _, _, attrs) => attrs,
+            FnKind::Closure(attrs) => attrs,
+        }
+    }
 }
 
 /// Each method of the Visitor trait is a hook to be potentially
@@ -310,7 +321,8 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
                                             unsafety,
                                             constness,
                                             abi,
-                                            item.vis),
+                                            item.vis,
+                                            &item.attrs),
                              declaration,
                              body,
                              item.span,
@@ -595,14 +607,14 @@ pub fn walk_fn_decl_nopat<'v, V: Visitor<'v>>(visitor: &mut V, function_declarat
 
 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
     match function_kind {
-        FnKind::ItemFn(_, generics, _, _, _, _) => {
+        FnKind::ItemFn(_, generics, _, _, _, _, _) => {
             visitor.visit_generics(generics);
         }
-        FnKind::Method(_, sig, _) => {
+        FnKind::Method(_, sig, _, _) => {
             visitor.visit_generics(&sig.generics);
             visitor.visit_explicit_self(&sig.explicit_self);
         }
-        FnKind::Closure => {}
+        FnKind::Closure(_) => {}
     }
 }
 
@@ -630,7 +642,10 @@ pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v Trai
             walk_fn_decl(visitor, &sig.decl);
         }
         MethodTraitItem(ref sig, Some(ref body)) => {
-            visitor.visit_fn(FnKind::Method(trait_item.name, sig, None),
+            visitor.visit_fn(FnKind::Method(trait_item.name,
+                                            sig,
+                                            None,
+                                            &trait_item.attrs),
                              &sig.decl,
                              body,
                              trait_item.span,
@@ -652,7 +667,10 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplIt
             visitor.visit_expr(expr);
         }
         ImplItemKind::Method(ref sig, ref body) => {
-            visitor.visit_fn(FnKind::Method(impl_item.name, sig, Some(impl_item.vis)),
+            visitor.visit_fn(FnKind::Method(impl_item.name,
+                                            sig,
+                                            Some(impl_item.vis),
+                                            &impl_item.attrs),
                              &sig.decl,
                              body,
                              impl_item.span,
@@ -758,7 +776,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
             walk_list!(visitor, visit_arm, arms);
         }
         ExprClosure(_, ref function_declaration, ref body) => {
-            visitor.visit_fn(FnKind::Closure,
+            visitor.visit_fn(FnKind::Closure(expression.attrs.as_attr_slice()),
                              function_declaration,
                              body,
                              expression.span,
diff --git a/src/librustc_front/util.rs b/src/librustc_front/util.rs
index 2c86c713b1b..f4f9cb75eaf 100644
--- a/src/librustc_front/util.rs
+++ b/src/librustc_front/util.rs
@@ -254,13 +254,13 @@ impl<'a, 'v, O: ast_util::IdVisitingOperation> Visitor<'v> for IdVisitor<'a, O>
         self.operation.visit_id(node_id);
 
         match function_kind {
-            FnKind::ItemFn(_, generics, _, _, _, _) => {
+            FnKind::ItemFn(_, generics, _, _, _, _, _) => {
                 self.visit_generics_helper(generics)
             }
-            FnKind::Method(_, sig, _) => {
+            FnKind::Method(_, sig, _, _) => {
                 self.visit_generics_helper(&sig.generics)
             }
-            FnKind::Closure => {}
+            FnKind::Closure(_) => {}
         }
 
         for argument in &function_declaration.inputs {
diff --git a/src/librustc_lint/bad_style.rs b/src/librustc_lint/bad_style.rs
index 925aec9894e..e399270197e 100644
--- a/src/librustc_lint/bad_style.rs
+++ b/src/librustc_lint/bad_style.rs
@@ -237,7 +237,7 @@ impl LateLintPass for NonSnakeCase {
                 fk: FnKind, _: &hir::FnDecl,
                 _: &hir::Block, span: Span, id: ast::NodeId) {
         match fk {
-            FnKind::Method(name, _, _) => match method_context(cx, id, span) {
+            FnKind::Method(name, _, _, _) => match method_context(cx, id, span) {
                 MethodLateContext::PlainImpl => {
                     self.check_snake_case(cx, "method", &name.as_str(), Some(span))
                 },
@@ -246,10 +246,10 @@ impl LateLintPass for NonSnakeCase {
                 },
                 _ => (),
             },
-            FnKind::ItemFn(name, _, _, _, _, _) => {
+            FnKind::ItemFn(name, _, _, _, _, _, _) => {
                 self.check_snake_case(cx, "function", &name.as_str(), Some(span))
             },
-            _ => (),
+            FnKind::Closure(_) => (),
         }
     }
 
diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs
index 88027931022..2ccb905b6ec 100644
--- a/src/librustc_lint/builtin.rs
+++ b/src/librustc_lint/builtin.rs
@@ -223,10 +223,10 @@ impl LateLintPass for UnsafeCode {
     fn check_fn(&mut self, cx: &LateContext, fk: FnKind, _: &hir::FnDecl,
                 _: &hir::Block, span: Span, _: ast::NodeId) {
         match fk {
-            FnKind::ItemFn(_, _, hir::Unsafety::Unsafe, _, _, _) =>
+            FnKind::ItemFn(_, _, hir::Unsafety::Unsafe, _, _, _, _) =>
                 cx.span_lint(UNSAFE_CODE, span, "declaration of an `unsafe` function"),
 
-            FnKind::Method(_, sig, _) => {
+            FnKind::Method(_, sig, _, _) => {
                 if sig.unsafety == hir::Unsafety::Unsafe {
                     cx.span_lint(UNSAFE_CODE, span, "implementation of an `unsafe` method")
                 }
@@ -670,7 +670,7 @@ impl LateLintPass for UnconditionalRecursion {
                 cx.tcx.impl_or_trait_item(cx.tcx.map.local_def_id(id)).as_opt_method()
             }
             // closures can't recur, so they don't matter.
-            FnKind::Closure => return
+            FnKind::Closure(_) => return
         };
 
         // Walk through this function (say `f`) looking to see if
diff --git a/src/librustc_mir/graphviz.rs b/src/librustc_mir/graphviz.rs
index f705c0591b5..bed83708ff8 100644
--- a/src/librustc_mir/graphviz.rs
+++ b/src/librustc_mir/graphviz.rs
@@ -43,16 +43,33 @@ where W: Write, I: Iterator<Item=(&'a NodeId, &'a Mir<'a>)> {
     Ok(())
 }
 
-/// Write a graphviz DOT node for the given basic block.
-fn write_node<W: Write>(block: BasicBlock, mir: &Mir, w: &mut W) -> io::Result<()> {
+/// Write a graphviz HTML-styled label for the given basic block, with
+/// all necessary escaping already performed. (This is suitable for
+/// emitting directly, as is done in this module, or for use with the
+/// LabelText::HtmlStr from libgraphviz.)
+///
+/// `init` and `fini` are callbacks for emitting additional rows of
+/// data (using HTML enclosed with `<tr>` in the emitted text).
+pub fn write_node_label<W: Write, INIT, FINI>(block: BasicBlock,
+                                              mir: &Mir,
+                                              w: &mut W,
+                                              num_cols: u32,
+                                              init: INIT,
+                                              fini: FINI) -> io::Result<()>
+    where INIT: Fn(&mut W) -> io::Result<()>,
+          FINI: Fn(&mut W) -> io::Result<()>
+{
     let data = mir.basic_block_data(block);
 
-    // Start a new node with the label to follow, in one of DOT's pseudo-HTML tables.
-    try!(write!(w, r#"    {} [shape="none", label=<"#, node(block)));
     try!(write!(w, r#"<table border="0" cellborder="1" cellspacing="0">"#));
 
     // Basic block number at the top.
-    try!(write!(w, r#"<tr><td bgcolor="gray" align="center">{}</td></tr>"#, block.index()));
+    try!(write!(w, r#"<tr><td {attrs} colspan="{colspan}">{blk}</td></tr>"#,
+                attrs=r#"bgcolor="gray" align="center""#,
+                colspan=num_cols,
+                blk=block.index()));
+
+    try!(init(w));
 
     // List of statements in the middle.
     if !data.statements.is_empty() {
@@ -69,8 +86,19 @@ fn write_node<W: Write>(block: BasicBlock, mir: &Mir, w: &mut W) -> io::Result<(
     data.terminator().fmt_head(&mut terminator_head).unwrap();
     try!(write!(w, r#"<tr><td align="left">{}</td></tr>"#, dot::escape_html(&terminator_head)));
 
-    // Close the table, node label, and the node itself.
-    writeln!(w, "</table>>];")
+    try!(fini(w));
+
+    // Close the table
+    writeln!(w, "</table>")
+}
+
+/// Write a graphviz DOT node for the given basic block.
+fn write_node<W: Write>(block: BasicBlock, mir: &Mir, w: &mut W) -> io::Result<()> {
+    // Start a new node with the label to follow, in one of DOT's pseudo-HTML tables.
+    try!(write!(w, r#"    {} [shape="none", label=<"#, node(block)));
+    try!(write_node_label(block, mir, w, 1, |_| Ok(()), |_| Ok(())));
+    // Close the node label and the node itself.
+    writeln!(w, ">];")
 }
 
 /// Write graphviz DOT edges with labels between the given basic block and all of its successors.
diff --git a/src/librustc_mir/mir_map.rs b/src/librustc_mir/mir_map.rs
index 4717c54ca64..05dbd63ef1a 100644
--- a/src/librustc_mir/mir_map.rs
+++ b/src/librustc_mir/mir_map.rs
@@ -132,7 +132,7 @@ impl<'a, 'm, 'tcx> Visitor<'tcx> for InnerDump<'a,'m,'tcx> {
                 body: &'tcx hir::Block,
                 span: Span,
                 id: ast::NodeId) {
-        let implicit_arg_tys = if let intravisit::FnKind::Closure = fk {
+        let implicit_arg_tys = if let intravisit::FnKind::Closure(..) = fk {
             vec![closure_self_ty(&self.tcx, id, body.id)]
         } else {
             vec![]
diff --git a/src/librustc_passes/consts.rs b/src/librustc_passes/consts.rs
index c964179d407..c2b76459418 100644
--- a/src/librustc_passes/consts.rs
+++ b/src/librustc_passes/consts.rs
@@ -132,10 +132,10 @@ impl<'a, 'tcx> CheckCrateVisitor<'a, 'tcx> {
         }
 
         let mode = match fk {
-            FnKind::ItemFn(_, _, _, hir::Constness::Const, _, _) => {
+            FnKind::ItemFn(_, _, _, hir::Constness::Const, _, _, _) => {
                 Mode::ConstFn
             }
-            FnKind::Method(_, m, _) => {
+            FnKind::Method(_, m, _, _) => {
                 if m.constness == hir::Constness::Const {
                     Mode::ConstFn
                 } else {
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index 9d09e8d1eb1..af8c9d81687 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -634,16 +634,16 @@ impl<'a, 'v, 'tcx> Visitor<'v> for Resolver<'a, 'tcx> {
                 _: Span,
                 node_id: NodeId) {
         let rib_kind = match function_kind {
-            FnKind::ItemFn(_, generics, _, _, _, _) => {
+            FnKind::ItemFn(_, generics, _, _, _, _, _) => {
                 self.visit_generics(generics);
                 ItemRibKind
             }
-            FnKind::Method(_, sig, _) => {
+            FnKind::Method(_, sig, _, _) => {
                 self.visit_generics(&sig.generics);
                 self.visit_explicit_self(&sig.explicit_self);
                 MethodRibKind
             }
-            FnKind::Closure => ClosureRibKind(node_id),
+            FnKind::Closure(_) => ClosureRibKind(node_id),
         };
         self.resolve_function(rib_kind, declaration, block);
     }
diff --git a/src/librustc_trans/trans/assert_dep_graph.rs b/src/librustc_trans/trans/assert_dep_graph.rs
index a186a8ea99c..11386715492 100644
--- a/src/librustc_trans/trans/assert_dep_graph.rs
+++ b/src/librustc_trans/trans/assert_dep_graph.rs
@@ -253,7 +253,9 @@ fn dump_graph(tcx: &TyCtxt) {
 
 pub struct GraphvizDepGraph(FnvHashSet<DepNode>, Vec<(DepNode, DepNode)>);
 
-impl<'a, 'tcx> dot::GraphWalk<'a, DepNode, (DepNode, DepNode)> for GraphvizDepGraph {
+impl<'a, 'tcx> dot::GraphWalk<'a> for GraphvizDepGraph {
+    type Node = DepNode;
+    type Edge = (DepNode, DepNode);
     fn nodes(&self) -> dot::Nodes<DepNode> {
         let nodes: Vec<_> = self.0.iter().cloned().collect();
         nodes.into_cow()
@@ -269,7 +271,9 @@ impl<'a, 'tcx> dot::GraphWalk<'a, DepNode, (DepNode, DepNode)> for GraphvizDepGr
     }
 }
 
-impl<'a, 'tcx> dot::Labeller<'a, DepNode, (DepNode, DepNode)> for GraphvizDepGraph {
+impl<'a, 'tcx> dot::Labeller<'a> for GraphvizDepGraph {
+    type Node = DepNode;
+    type Edge = (DepNode, DepNode);
     fn graph_id(&self) -> dot::Id {
         dot::Id::new("DependencyGraph").unwrap()
     }
diff --git a/src/rustc/Cargo.lock b/src/rustc/Cargo.lock
index 03e7aaca0f7..9ef0b400022 100644
--- a/src/rustc/Cargo.lock
+++ b/src/rustc/Cargo.lock
@@ -109,6 +109,7 @@ dependencies = [
  "log 0.0.0",
  "rustc 0.0.0",
  "rustc_front 0.0.0",
+ "rustc_mir 0.0.0",
  "syntax 0.0.0",
 ]