remove the `closure_tys` map from `TypeckTables`

The information we need is now part of the closure type.

6 files changed, 34 insertions, 45 deletions

diff --git a/src/librustc/infer/mod.rs b/src/librustc/infer/mod.rs
index 905e45bf9f0..05f1184fad3 100644
--- a/src/librustc/infer/mod.rs
+++ b/src/librustc/infer/mod.rs
@@ -1484,9 +1484,17 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         if let Some(tables) = self.in_progress_tables {
             if let Some(id) = self.tcx.hir.as_local_node_id(def_id) {
                 let hir_id = self.tcx.hir.node_to_hir_id(id);
-                if let Some(&ty) = tables.borrow().closure_tys().get(hir_id) {
-                    return ty;
-                }
+                let closure_ty = tables.borrow().node_id_to_type(hir_id);
+                let (closure_def_id, closure_substs) = match closure_ty.sty {
+                    ty::TyClosure(closure_def_id, closure_substs) =>
+                        (closure_def_id, closure_substs),
+                    _ =>
+                        bug!("closure with non-closure type: {:?}", closure_ty),
+                };
+                assert_eq!(def_id, closure_def_id);
+                let closure_sig_ty = closure_substs.closure_sig_ty(def_id, self.tcx);
+                let closure_sig_ty = self.shallow_resolve(&closure_sig_ty);
+                return closure_sig_ty.fn_sig(self.tcx);
             }
         }
 
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 6bd1a3564b1..ccd851799fe 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -356,9 +356,6 @@ pub struct TypeckTables<'tcx> {
     /// Borrows
     pub upvar_capture_map: ty::UpvarCaptureMap<'tcx>,
 
-    /// Records the type of each closure.
-    closure_tys: ItemLocalMap<ty::PolyFnSig<'tcx>>,
-
     /// Records the reasons that we picked the kind of each closure;
     /// not all closures are present in the map.
     closure_kind_origins: ItemLocalMap<(Span, ast::Name)>,
@@ -413,7 +410,6 @@ impl<'tcx> TypeckTables<'tcx> {
             upvar_capture_map: FxHashMap(),
             generator_sigs: ItemLocalMap(),
             generator_interiors: ItemLocalMap(),
-            closure_tys: ItemLocalMap(),
             closure_kind_origins: ItemLocalMap(),
             liberated_fn_sigs: ItemLocalMap(),
             fru_field_types: ItemLocalMap(),
@@ -609,21 +605,6 @@ impl<'tcx> TypeckTables<'tcx> {
         self.upvar_capture_map[&upvar_id]
     }
 
-    pub fn closure_tys(&self) -> LocalTableInContext<ty::PolyFnSig<'tcx>> {
-        LocalTableInContext {
-            local_id_root: self.local_id_root,
-            data: &self.closure_tys
-        }
-    }
-
-    pub fn closure_tys_mut(&mut self)
-                           -> LocalTableInContextMut<ty::PolyFnSig<'tcx>> {
-        LocalTableInContextMut {
-            local_id_root: self.local_id_root,
-            data: &mut self.closure_tys
-        }
-    }
-
     pub fn closure_kind_origins(&self) -> LocalTableInContext<(Span, ast::Name)> {
         LocalTableInContext {
             local_id_root: self.local_id_root,
@@ -730,7 +711,6 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for TypeckTables<'gcx> {
             ref pat_binding_modes,
             ref pat_adjustments,
             ref upvar_capture_map,
-            ref closure_tys,
             ref closure_kind_origins,
             ref liberated_fn_sigs,
             ref fru_field_types,
@@ -773,7 +753,6 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for TypeckTables<'gcx> {
                  hcx.def_path_hash(closure_def_id))
             });
 
-            closure_tys.hash_stable(hcx, hasher);
             closure_kind_origins.hash_stable(hcx, hasher);
             liberated_fn_sigs.hash_stable(hcx, hasher);
             fru_field_types.hash_stable(hcx, hasher);
diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs
index 77aa3553967..e581eac9ccd 100644
--- a/src/librustc/ty/sty.rs
+++ b/src/librustc/ty/sty.rs
@@ -297,24 +297,19 @@ impl<'tcx> ClosureSubsts<'tcx> {
     }
 
     /// Returns the closure kind for this closure; may return a type
-    /// variable during inference.
+    /// variable during inference. To get the closure kind during
+    /// inference, use `infcx.closure_kind(def_id, substs)`.
     pub fn closure_kind_ty(self, def_id: DefId, tcx: TyCtxt<'_, '_, '_>) -> Ty<'tcx> {
         self.split(def_id, tcx).closure_kind_ty
     }
 
     /// Returns the type representing the closure signature for this
-    /// closure; may contain type variables during inference.
+    /// closure; may contain type variables during inference. To get
+    /// the closure signature during inference, use
+    /// `infcx.fn_sig(def_id)`.
     pub fn closure_sig_ty(self, def_id: DefId, tcx: TyCtxt<'_, '_, '_>) -> Ty<'tcx> {
         self.split(def_id, tcx).closure_sig_ty
     }
-
-    /// Extracts the signature from the closure.
-    pub fn closure_sig(self, def_id: DefId, tcx: TyCtxt<'_, '_, '_>) -> ty::PolyFnSig<'tcx> {
-        match &self.split(def_id, tcx).closure_sig_ty.sty {
-            ty::TyFnPtr(sig) => *sig,
-            t => bug!("closure_sig_ty is not a fn-ptr: {:?}", t),
-        }
-    }
 }
 
 impl<'tcx> ClosureSubsts<'tcx> {
@@ -324,6 +319,16 @@ impl<'tcx> ClosureSubsts<'tcx> {
     pub fn closure_kind(self, def_id: DefId, tcx: TyCtxt<'_, 'tcx, 'tcx>) -> ty::ClosureKind {
         self.split(def_id, tcx).closure_kind_ty.to_opt_closure_kind().unwrap()
     }
+
+    /// Extracts the signature from the closure; only usable outside
+    /// of an inference context, because in that context we know that
+    /// there are no type variables.
+    pub fn closure_sig(self, def_id: DefId, tcx: TyCtxt<'_, 'tcx, 'tcx>) -> ty::PolyFnSig<'tcx> {
+        match self.closure_sig_ty(def_id, tcx).sty {
+            ty::TyFnPtr(sig) => sig,
+            ref t => bug!("closure_sig_ty is not a fn-ptr: {:?}", t),
+        }
+    }
 }
 
 impl<'a, 'gcx, 'tcx> ClosureSubsts<'tcx> {
diff --git a/src/librustc_typeck/check/closure.rs b/src/librustc_typeck/check/closure.rs
index 6c20468c286..5fd1a0afb3e 100644
--- a/src/librustc_typeck/check/closure.rs
+++ b/src/librustc_typeck/check/closure.rs
@@ -146,7 +146,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                            sig_fn_ptr_ty,
                            substs.closure_sig_ty(expr_def_id, self.tcx));
 
-        self.tables.borrow_mut().closure_tys_mut().insert(expr.hir_id, sig);
         if let Some(kind) = opt_kind {
             self.demand_eqtype(expr.span,
                                kind.to_ty(self.tcx),
diff --git a/src/librustc_typeck/check/writeback.rs b/src/librustc_typeck/check/writeback.rs
index 48af2f0eff7..cf5864e910d 100644
--- a/src/librustc_typeck/check/writeback.rs
+++ b/src/librustc_typeck/check/writeback.rs
@@ -243,15 +243,6 @@ impl<'cx, 'gcx, 'tcx> WritebackCx<'cx, 'gcx, 'tcx> {
         debug_assert_eq!(fcx_tables.local_id_root, self.tables.local_id_root);
         let common_local_id_root = fcx_tables.local_id_root.unwrap();
 
-        for (&id, closure_ty) in fcx_tables.closure_tys().iter() {
-            let hir_id = hir::HirId {
-                owner: common_local_id_root.index,
-                local_id: id,
-            };
-            let closure_ty = self.resolve(closure_ty, &hir_id);
-            self.tables.closure_tys_mut().insert(hir_id, closure_ty);
-        }
-
         for (&id, &origin) in fcx_tables.closure_kind_origins().iter() {
             let hir_id = hir::HirId {
                 owner: common_local_id_root.index,
diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs
index 7a03d97c18a..90a3ab75751 100644
--- a/src/librustc_typeck/collect.rs
+++ b/src/librustc_typeck/collect.rs
@@ -1265,7 +1265,14 @@ fn fn_sig<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         }
 
         NodeExpr(&hir::Expr { node: hir::ExprClosure(..), hir_id, .. }) => {
-            tcx.typeck_tables_of(def_id).closure_tys()[hir_id]
+            let tables = tcx.typeck_tables_of(def_id);
+            match tables.node_id_to_type(hir_id).sty {
+                ty::TyClosure(closure_def_id, closure_substs) => {
+                    assert_eq!(def_id, closure_def_id);
+                    return closure_substs.closure_sig(closure_def_id, tcx);
+                }
+                ref t => bug!("closure with non-closure type: {:?}", t),
+            }
         }
 
         x => {