remove ast_ty_to_ty_cache entirely

Author: nikomatsakis

Diff for: src/librustc/ty/context.rs

@@ -556,9 +556,6 @@ pub struct GlobalCtxt<'tcx> {
     /// error reporting, and so is lazily initialised and generally
     /// shouldn't taint the common path (hence the RefCell).
     pub all_traits: RefCell<Option<Vec<DefId>>>,
-
-    /// HIR Ty -> Ty lowering cache.
-    pub ast_ty_to_ty_cache: RefCell<NodeMap<Ty<'tcx>>>,
 }
 
 impl<'tcx> GlobalCtxt<'tcx> {
@@ -770,7 +767,6 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             derive_macros: RefCell::new(NodeMap()),
             stability_interner: RefCell::new(FxHashSet()),
             all_traits: RefCell::new(None),
-            ast_ty_to_ty_cache: RefCell::new(NodeMap()),
        }, f)
     }
 

Diff for: src/librustc_typeck/astconv.rs

@@ -25,9 +25,8 @@ use rustc::ty::wf::object_region_bounds;
 use rustc_back::slice;
 use require_c_abi_if_variadic;
 use util::common::{ErrorReported, FN_OUTPUT_NAME};
-use util::nodemap::{NodeMap, FxHashSet};
+use util::nodemap::FxHashSet;
 
-use std::cell::RefCell;
 use std::iter;
 use syntax::{abi, ast};
 use syntax::feature_gate::{GateIssue, emit_feature_err};
@@ -37,9 +36,6 @@ use syntax_pos::Span;
 pub trait AstConv<'gcx, 'tcx> {
     fn tcx<'a>(&'a self) -> TyCtxt<'a, 'gcx, 'tcx>;
 
-    /// A cache used for the result of `ast_ty_to_ty_cache`
-    fn ast_ty_to_ty_cache(&self) -> &RefCell<NodeMap<Ty<'tcx>>>;
-
     /// Returns the set of bounds in scope for the type parameter with
     /// the given id.
     fn get_type_parameter_bounds(&self, span: Span, def_id: DefId)
@@ -1074,11 +1070,6 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
 
         let tcx = self.tcx();
 
-        let cache = self.ast_ty_to_ty_cache();
-        if let Some(ty) = cache.borrow().get(&ast_ty.id) {
-            return ty;
-        }
-
         let result_ty = match ast_ty.node {
             hir::TySlice(ref ty) => {
                 tcx.mk_slice(self.ast_ty_to_ty(&ty))
@@ -1240,8 +1231,6 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
             }
         };
 
-        cache.borrow_mut().insert(ast_ty.id, result_ty);
-
         result_ty
     }
 

Diff for: src/librustc_typeck/check/mod.rs

@@ -451,8 +451,6 @@ impl<'gcx, 'tcx> EnclosingBreakables<'gcx, 'tcx> {
 }
 
 pub struct FnCtxt<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
-    ast_ty_to_ty_cache: RefCell<NodeMap<Ty<'tcx>>>,
-
     body_id: ast::NodeId,
 
     // Number of errors that had been reported when we started
@@ -1516,10 +1514,6 @@ pub fn check_enum<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 impl<'a, 'gcx, 'tcx> AstConv<'gcx, 'tcx> for FnCtxt<'a, 'gcx, 'tcx> {
     fn tcx<'b>(&'b self) -> TyCtxt<'b, 'gcx, 'tcx> { self.tcx }
 
-    fn ast_ty_to_ty_cache(&self) -> &RefCell<NodeMap<Ty<'tcx>>> {
-        &self.ast_ty_to_ty_cache
-    }
-
     fn get_free_substs(&self) -> Option<&Substs<'tcx>> {
         Some(&self.parameter_environment.free_substs)
     }
@@ -1621,7 +1615,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                body_id: ast::NodeId)
                -> FnCtxt<'a, 'gcx, 'tcx> {
         FnCtxt {
-            ast_ty_to_ty_cache: RefCell::new(NodeMap()),
             body_id: body_id,
             err_count_on_creation: inh.tcx.sess.err_count(),
             ret_coercion: None,

Diff for: src/librustc_typeck/check/writeback.rs

@@ -43,7 +43,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         wbcx.visit_liberated_fn_sigs();
         wbcx.visit_fru_field_types();
         wbcx.visit_anon_types();
-        wbcx.visit_type_nodes();
         wbcx.visit_cast_types();
         wbcx.visit_lints();
         wbcx.visit_free_region_map();
@@ -442,13 +441,6 @@ impl<'cx, 'gcx, 'tcx> WritebackCx<'cx, 'gcx, 'tcx> {
         }
     }
 
-    fn visit_type_nodes(&self) {
-        for (&id, ty) in self.fcx.ast_ty_to_ty_cache.borrow().iter() {
-            let ty = self.resolve(ty, &id);
-            self.fcx.tcx.ast_ty_to_ty_cache.borrow_mut().insert(id, ty);
-        }
-    }
-
     fn resolve<T>(&self, x: &T, span: &Locatable) -> T::Lifted
         where T: TypeFoldable<'tcx> + ty::Lift<'gcx>
     {

Diff for: src/librustc_typeck/collect.rs

@@ -64,11 +64,10 @@ use rustc::ty::{ToPredicate, ReprOptions};
 use rustc::ty::{self, AdtKind, ToPolyTraitRef, Ty, TyCtxt};
 use rustc::ty::maps::Providers;
 use rustc::ty::util::IntTypeExt;
-use util::nodemap::{NodeMap, FxHashMap};
+use util::nodemap::FxHashMap;
 
 use rustc_const_math::ConstInt;
 
-use std::cell::RefCell;
 use std::collections::BTreeMap;
 
 use syntax::{abi, ast};
@@ -198,10 +197,6 @@ impl<'a,'tcx> ItemCtxt<'a,'tcx> {
 impl<'a, 'tcx> AstConv<'tcx, 'tcx> for ItemCtxt<'a, 'tcx> {
     fn tcx<'b>(&'b self) -> TyCtxt<'b, 'tcx, 'tcx> { self.tcx }
 
-    fn ast_ty_to_ty_cache(&self) -> &RefCell<NodeMap<Ty<'tcx>>> {
-        &self.tcx.ast_ty_to_ty_cache
-    }
-
     fn get_type_parameter_bounds(&self,
                                  span: Span,
                                  def_id: DefId)