rustc: remove ParamSpace from Substs.

Author: eddyb

src/librustc/middle/dead.rs

@@ -18,7 +18,7 @@ use hir::{self, pat_util, PatKind};
 use hir::intravisit::{self, Visitor};
 
 use middle::privacy;
-use ty::{self, subst, TyCtxt};
+use ty::{self, TyCtxt};
 use hir::def::Def;
 use hir::def_id::{DefId};
 use lint;
@@ -95,7 +95,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
             Def::AssociatedTy(..) | Def::Method(_) | Def::AssociatedConst(_)
             if self.tcx.trait_of_item(def.def_id()).is_some() => {
                 if let Some(substs) = self.tcx.tables.borrow().item_substs.get(&id) {
-                    match substs.substs.types.get(subst::TypeSpace, 0).sty {
+                    match substs.substs.types[0].sty {
                         TyEnum(tyid, _) | TyStruct(tyid, _) => {
                             self.check_def_id(tyid.did)
                         }

src/librustc/middle/resolve_lifetime.rs

@@ -24,9 +24,7 @@ use session::Session;
 use hir::def::{Def, DefMap};
 use hir::def_id::DefId;
 use middle::region;
-use ty::subst;
 use ty;
-use std::fmt;
 use std::mem::replace;
 use syntax::ast;
 use syntax::parse::token::keywords;
@@ -41,8 +39,7 @@ use hir::intravisit::{self, Visitor, FnKind};
 #[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)]
 pub enum DefRegion {
     DefStaticRegion,
-    DefEarlyBoundRegion(/* space */ subst::ParamSpace,
-                        /* index */ u32,
+    DefEarlyBoundRegion(/* index */ u32,
                         /* lifetime decl */ ast::NodeId),
     DefLateBoundRegion(ty::DebruijnIndex,
                        /* lifetime decl */ ast::NodeId),
@@ -90,10 +87,11 @@ struct LifetimeContext<'a, 'tcx: 'a> {
     labels_in_fn: Vec<(ast::Name, Span)>,
 }
 
+#[derive(PartialEq, Debug)]
 enum ScopeChain<'a> {
-    /// EarlyScope(i, ['a, 'b, ...], s) extends s with early-bound
-    /// lifetimes, assigning indexes 'a => i, 'b => i+1, ... etc.
-    EarlyScope(subst::ParamSpace, &'a [hir::LifetimeDef], Scope<'a>),
+    /// EarlyScope(['a, 'b, ...], s) extends s with early-bound
+    /// lifetimes.
+    EarlyScope(&'a [hir::LifetimeDef], Scope<'a>),
     /// LateScope(['a, 'b, ...], s) extends s with late-bound
     /// lifetimes introduced by the declaration binder_id.
     LateScope(&'a [hir::LifetimeDef], Scope<'a>),
@@ -159,8 +157,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for LifetimeContext<'a, 'tcx> {
                 hir::ItemImpl(_, _, ref generics, _, _, _) => {
                     // These kinds of items have only early bound lifetime parameters.
                     let lifetimes = &generics.lifetimes;
-                    let early_scope = EarlyScope(subst::TypeSpace, lifetimes, &ROOT_SCOPE);
-                    this.with(early_scope, |old_scope, this| {
+                    this.with(EarlyScope(lifetimes, &ROOT_SCOPE), |old_scope, this| {
                         this.check_lifetime_defs(old_scope, lifetimes);
                         intravisit::walk_item(this, item);
                     });
@@ -181,11 +178,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for LifetimeContext<'a, 'tcx> {
         self.with(RootScope, |_, this| {
             match item.node {
                 hir::ForeignItemFn(ref decl, ref generics) => {
-                    this.visit_early_late(item.id,
-                                          subst::FnSpace,
-                                          decl,
-                                          generics,
-                                          |this| {
+                    this.visit_early_late(item.id, decl, generics, |this| {
                         intravisit::walk_foreign_item(this, item);
                     })
                 }
@@ -203,14 +196,13 @@ impl<'a, 'tcx, 'v> Visitor<'v> for LifetimeContext<'a, 'tcx> {
                 b: &'v hir::Block, s: Span, fn_id: ast::NodeId) {
         match fk {
             FnKind::ItemFn(_, generics, _, _, _, _, _) => {
-                self.visit_early_late(fn_id, subst::FnSpace, decl, generics, |this| {
+                self.visit_early_late(fn_id,decl, generics, |this| {
                     this.add_scope_and_walk_fn(fk, decl, b, s, fn_id)
                 })
             }
             FnKind::Method(_, sig, _, _) => {
                 self.visit_early_late(
                     fn_id,
-                    subst::FnSpace,
                     decl,
                     &sig.generics,
                     |this| this.add_scope_and_walk_fn(fk, decl, b, s, fn_id));
@@ -263,7 +255,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for LifetimeContext<'a, 'tcx> {
 
         if let hir::MethodTraitItem(ref sig, None) = trait_item.node {
             self.visit_early_late(
-                trait_item.id, subst::FnSpace,
+                trait_item.id,
                 &sig.decl, &sig.generics,
                 |this| intravisit::walk_trait_item(this, trait_item))
         } else {
@@ -469,7 +461,7 @@ fn extract_labels(ctxt: &mut LifetimeContext, b: &hir::Block) {
                 FnScope { s, .. } => { scope = s; }
                 RootScope => { return; }
 
-                EarlyScope(_, lifetimes, s) |
+                EarlyScope(lifetimes, s) |
                 LateScope(lifetimes, s) => {
                     for lifetime_def in lifetimes {
                         // FIXME (#24278): non-hygienic comparison
@@ -557,7 +549,6 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
     /// ordering is not important there.
     fn visit_early_late<F>(&mut self,
                            fn_id: ast::NodeId,
-                           early_space: subst::ParamSpace,
                            decl: &hir::FnDecl,
                            generics: &hir::Generics,
                            walk: F) where
@@ -576,7 +567,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                     .partition(|l| self.map.late_bound.contains_key(&l.lifetime.id));
 
         let this = self;
-        this.with(EarlyScope(early_space, &early, this.scope), move |old_scope, this| {
+        this.with(EarlyScope(&early, this.scope), move |old_scope, this| {
             this.with(LateScope(&late, this.scope), move |_, this| {
                 this.check_lifetime_defs(old_scope, &generics.lifetimes);
                 walk(this);
@@ -606,11 +597,19 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                     break;
                 }
 
-                EarlyScope(space, lifetimes, s) => {
+                EarlyScope(lifetimes, s) => {
                     match search_lifetimes(lifetimes, lifetime_ref) {
-                        Some((index, lifetime_def)) => {
+                        Some((mut index, lifetime_def)) => {
+                            // Adjust for nested early scopes, e.g. in methods.
+                            let mut parent = s;
+                            while let EarlyScope(lifetimes, s) = *parent {
+                                index += lifetimes.len() as u32;
+                                parent = s;
+                            }
+                            assert_eq!(*parent, RootScope);
+
                             let decl_id = lifetime_def.id;
-                            let def = DefEarlyBoundRegion(space, index, decl_id);
+                            let def = DefEarlyBoundRegion(index, decl_id);
                             self.insert_lifetime(lifetime_ref, def);
                             return;
                         }
@@ -672,7 +671,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                     break;
                 }
 
-                EarlyScope(_, lifetimes, s) |
+                EarlyScope(lifetimes, s) |
                 LateScope(lifetimes, s) => {
                     search_result = search_lifetimes(lifetimes, lifetime_ref);
                     if search_result.is_some() {
@@ -768,7 +767,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                     return;
                 }
 
-                EarlyScope(_, lifetimes, s) |
+                EarlyScope(lifetimes, s) |
                 LateScope(lifetimes, s) => {
                     if let Some((_, lifetime_def)) = search_lifetimes(lifetimes, lifetime) {
                         signal_shadowing_problem(
@@ -963,14 +962,3 @@ fn insert_late_bound_lifetimes(map: &mut NamedRegionMap,
         }
     }
 }
-
-impl<'a> fmt::Debug for ScopeChain<'a> {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            EarlyScope(space, defs, _) => write!(fmt, "EarlyScope({:?}, {:?})", space, defs),
-            LateScope(defs, _) => write!(fmt, "LateScope({:?})", defs),
-            FnScope { fn_id, body_id, s: _ } => write!(fmt, "FnScope({:?}, {:?})", fn_id, body_id),
-            RootScope => write!(fmt, "RootScope"),
-        }
-    }
-}

src/librustc/traits/error_reporting.rs

@@ -31,7 +31,7 @@ use ty::{self, ToPredicate, ToPolyTraitRef, Ty, TyCtxt, TypeFoldable};
 use ty::error::ExpectedFound;
 use ty::fast_reject;
 use ty::fold::TypeFolder;
-use ty::subst::{Subst, TypeSpace};
+use ty::subst::Subst;
 use util::nodemap::{FnvHashMap, FnvHashSet};
 
 use std::cmp;
@@ -232,8 +232,8 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 if let Ok(..) = self.can_equate(&trait_self_ty, &impl_self_ty) {
                     self_match_impls.push(def_id);
 
-                    if trait_ref.substs.types.get_slice(TypeSpace)[1..].iter()
-                        .zip(&impl_trait_ref.substs.types.get_slice(TypeSpace)[1..])
+                    if trait_ref.substs.types[1..].iter()
+                        .zip(&impl_trait_ref.substs.types[1..])
                         .all(|(u,v)| self.fuzzy_match_tys(u, v))
                     {
                         fuzzy_match_impls.push(def_id);

src/librustc/traits/fulfill.rs

@@ -142,7 +142,7 @@ impl<'a, 'gcx, 'tcx> DeferredObligation<'tcx> {
         // Auto trait obligations on `impl Trait`.
         if tcx.trait_has_default_impl(predicate.def_id()) {
             let substs = predicate.skip_binder().trait_ref.substs;
-            if substs.types.as_full_slice().len() == 1 && substs.regions.is_empty() {
+            if substs.types.len() == 1 && substs.regions.is_empty() {
                 if let ty::TyAnon(..) = predicate.skip_binder().self_ty().sty {
                     return true;
                 }

src/librustc/traits/select.rs

@@ -36,7 +36,7 @@ use super::util;
 use hir::def_id::DefId;
 use infer;
 use infer::{InferCtxt, InferOk, TypeFreshener, TypeOrigin};
-use ty::subst::{Subst, Substs, TypeSpace};
+use ty::subst::{Subst, Substs};
 use ty::{self, ToPredicate, ToPolyTraitRef, Ty, TyCtxt, TypeFoldable};
 use traits;
 use ty::fast_reject;
@@ -1936,7 +1936,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
             // for `PhantomData<T>`, we pass `T`
             ty::TyStruct(def, substs) if def.is_phantom_data() => {
-                substs.types.as_full_slice().to_vec()
+                substs.types.to_vec()
             }
 
             ty::TyStruct(def, substs) | ty::TyEnum(def, substs) => {
@@ -2585,11 +2585,10 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 } else {
                     return Err(Unimplemented);
                 };
-                let mut ty_params = BitVector::new(substs_a.types.len(TypeSpace));
+                let mut ty_params = BitVector::new(substs_a.types.len());
                 let mut found = false;
                 for ty in field.walk() {
                     if let ty::TyParam(p) = ty.sty {
-                        assert!(p.space == TypeSpace);
                         ty_params.insert(p.idx as usize);
                         found = true;
                     }
@@ -2602,13 +2601,13 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                 // TyError and ensure they do not affect any other fields.
                 // This could be checked after type collection for any struct
                 // with a potentially unsized trailing field.
-                let types = substs_a.types.map_enumerated(|(_, i, ty)| {
+                let types = substs_a.types.iter().enumerate().map(|(i, ty)| {
                     if ty_params.contains(i) {
                         tcx.types.err
                     } else {
                         ty
                     }
-                });
+                }).collect();
                 let substs = Substs::new(tcx, types, substs_a.regions.clone());
                 for &ty in fields.split_last().unwrap().1 {
                     if ty.subst(tcx, substs).references_error() {
@@ -2622,13 +2621,13 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
 
                 // Check that the source structure with the target's
                 // type parameters is a subtype of the target.
-                let types = substs_a.types.map_enumerated(|(_, i, ty)| {
+                let types = substs_a.types.iter().enumerate().map(|(i, ty)| {
                     if ty_params.contains(i) {
-                        *substs_b.types.get(TypeSpace, i)
+                        substs_b.types[i]
                     } else {
                         ty
                     }
-                });
+                }).collect();
                 let substs = Substs::new(tcx, types, substs_a.regions.clone());
                 let new_struct = tcx.mk_struct(def, substs);
                 let origin = TypeOrigin::Misc(obligation.cause.span);

src/librustc/traits/specialize/mod.rs

@@ -44,11 +44,10 @@ pub struct OverlapError {
 /// When we have selected one impl, but are actually using item definitions from
 /// a parent impl providing a default, we need a way to translate between the
 /// type parameters of the two impls. Here the `source_impl` is the one we've
-/// selected, and `source_substs` is a substitution of its generics (and
-/// possibly some relevant `FnSpace` variables as well). And `target_node` is
-/// the impl/trait we're actually going to get the definition from. The resulting
-/// substitution will map from `target_node`'s generics to `source_impl`'s
-/// generics as instantiated by `source_subst`.
+/// selected, and `source_substs` is a substitution of its generics.
+/// And `target_node` is the impl/trait we're actually going to get the
+/// definition from. The resulting substitution will map from `target_node`'s
+/// generics to `source_impl`'s generics as instantiated by `source_subst`.
 ///
 /// For example, consider the following scenario:
 ///

src/librustc/ty/context.rs

@@ -23,7 +23,7 @@ use middle::free_region::FreeRegionMap;
 use middle::region::RegionMaps;
 use middle::resolve_lifetime;
 use middle::stability;
-use ty::subst::{self, Substs};
+use ty::subst::Substs;
 use traits;
 use ty::{self, TraitRef, Ty, TypeAndMut};
 use ty::{TyS, TypeVariants};
@@ -1346,18 +1346,17 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     }
 
     pub fn mk_param(self,
-                    space: subst::ParamSpace,
                     index: u32,
                     name: Name) -> Ty<'tcx> {
-        self.mk_ty(TyParam(ParamTy { space: space, idx: index, name: name }))
+        self.mk_ty(TyParam(ParamTy { idx: index, name: name }))
     }
 
     pub fn mk_self_type(self) -> Ty<'tcx> {
-        self.mk_param(subst::TypeSpace, 0, keywords::SelfType.name())
+        self.mk_param(0, keywords::SelfType.name())
     }
 
     pub fn mk_param_from_def(self, def: &ty::TypeParameterDef) -> Ty<'tcx> {
-        self.mk_param(def.space, def.index, def.name)
+        self.mk_param(def.index, def.name)
     }
 
     pub fn mk_anon(self, def_id: DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {

src/librustc/ty/flags.rs

@@ -208,8 +208,8 @@ impl FlagComputation {
     }
 
     fn add_substs(&mut self, substs: &Substs) {
-        self.add_tys(substs.types.as_full_slice());
-        for &r in substs.regions.as_full_slice() {
+        self.add_tys(&substs.types);
+        for &r in &substs.regions {
             self.add_region(r);
         }
     }