replace &'tcx Substs with SubstsRef

src/librustc/dep_graph/dep_node.rs

@@ -67,7 +67,7 @@ use crate::traits::query::{
 };
 use crate::ty::{TyCtxt, FnSig, Instance, InstanceDef,
          ParamEnv, ParamEnvAnd, Predicate, PolyFnSig, PolyTraitRef, Ty};
-use crate::ty::subst::Substs;
+use crate::ty::subst::SubstsRef;
 
 // erase!() just makes tokens go away. It's used to specify which macro argument
 // is repeated (i.e., which sub-expression of the macro we are in) but don't need
@@ -661,7 +661,7 @@ define_dep_nodes!( <'tcx>
     [] TypeOpNormalizePolyFnSig(CanonicalTypeOpNormalizeGoal<'tcx, PolyFnSig<'tcx>>),
     [] TypeOpNormalizeFnSig(CanonicalTypeOpNormalizeGoal<'tcx, FnSig<'tcx>>),
 
-    [] SubstituteNormalizeAndTestPredicates { key: (DefId, &'tcx Substs<'tcx>) },
+    [] SubstituteNormalizeAndTestPredicates { key: (DefId, SubstsRef<'tcx>) },
     [] MethodAutoderefSteps(CanonicalTyGoal<'tcx>),
 
     [input] TargetFeaturesWhitelist,

src/librustc/infer/combine.rs

@@ -34,7 +34,7 @@ use crate::ty::{IntType, UintType};
 use crate::ty::{self, Ty, TyCtxt};
 use crate::ty::error::TypeError;
 use crate::ty::relate::{self, Relate, RelateResult, TypeRelation};
-use crate::ty::subst::Substs;
+use crate::ty::subst::SubstsRef;
 use crate::traits::{Obligation, PredicateObligations};
 
 use syntax::ast;
@@ -373,9 +373,9 @@ impl<'cx, 'gcx, 'tcx> TypeRelation<'cx, 'gcx, 'tcx> for Generalizer<'cx, 'gcx, '
 
     fn relate_item_substs(&mut self,
                           item_def_id: DefId,
-                          a_subst: &'tcx Substs<'tcx>,
-                          b_subst: &'tcx Substs<'tcx>)
-                          -> RelateResult<'tcx, &'tcx Substs<'tcx>>
+                          a_subst: SubstsRef<'tcx>,
+                          b_subst: SubstsRef<'tcx>)
+                          -> RelateResult<'tcx, SubstsRef<'tcx>>
     {
         if self.ambient_variance == ty::Variance::Invariant {
             // Avoid fetching the variance if we are in an invariant

src/librustc/infer/equate.rs

@@ -5,7 +5,7 @@ use crate::hir::def_id::DefId;
 
 use crate::ty::{self, Ty, TyCtxt};
 use crate::ty::TyVar;
-use crate::ty::subst::Substs;
+use crate::ty::subst::SubstsRef;
 use crate::ty::relate::{self, Relate, RelateResult, TypeRelation};
 
 /// Ensures `a` is made equal to `b`. Returns `a` on success.
@@ -33,9 +33,9 @@ impl<'combine, 'infcx, 'gcx, 'tcx> TypeRelation<'infcx, 'gcx, 'tcx>
 
     fn relate_item_substs(&mut self,
                           _item_def_id: DefId,
-                          a_subst: &'tcx Substs<'tcx>,
-                          b_subst: &'tcx Substs<'tcx>)
-                          -> RelateResult<'tcx, &'tcx Substs<'tcx>>
+                          a_subst: SubstsRef<'tcx>,
+                          b_subst: SubstsRef<'tcx>)
+                          -> RelateResult<'tcx, SubstsRef<'tcx>>
     {
         // N.B., once we are equating types, we don't care about
         // variance, so don't try to lookup the variance here. This

src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs

@@ -7,7 +7,7 @@ use crate::infer::{SubregionOrigin, TypeTrace};
 use crate::traits::{ObligationCause, ObligationCauseCode};
 use crate::ty;
 use crate::ty::error::ExpectedFound;
-use crate::ty::subst::Substs;
+use crate::ty::subst::SubstsRef;
 use crate::util::ppaux::RegionHighlightMode;
 
 impl NiceRegionError<'me, 'gcx, 'tcx> {
@@ -175,8 +175,8 @@ impl NiceRegionError<'me, 'gcx, 'tcx> {
         sub_placeholder: Option<ty::Region<'tcx>>,
         sup_placeholder: Option<ty::Region<'tcx>>,
         trait_def_id: DefId,
-        expected_substs: &'tcx Substs<'tcx>,
-        actual_substs: &'tcx Substs<'tcx>,
+        expected_substs: SubstsRef<'tcx>,
+        actual_substs: SubstsRef<'tcx>,
     ) -> DiagnosticBuilder<'me> {
         debug!(
             "try_report_placeholders_trait(\

src/librustc/infer/mod.rs

@@ -18,7 +18,7 @@ use crate::traits::{self, ObligationCause, PredicateObligations, TraitEngine};
 use crate::ty::error::{ExpectedFound, TypeError, UnconstrainedNumeric};
 use crate::ty::fold::TypeFoldable;
 use crate::ty::relate::RelateResult;
-use crate::ty::subst::{Kind, Substs};
+use crate::ty::subst::{Kind, Substs, SubstsRef};
 use crate::ty::{self, GenericParamDefKind, Ty, TyCtxt, CtxtInterners};
 use crate::ty::{FloatVid, IntVid, TyVid};
 use crate::util::nodemap::FxHashMap;
@@ -1088,7 +1088,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
     /// Given a set of generics defined on a type or impl, returns a substitution mapping each
     /// type/region parameter to a fresh inference variable.
-    pub fn fresh_substs_for_item(&self, span: Span, def_id: DefId) -> &'tcx Substs<'tcx> {
+    pub fn fresh_substs_for_item(&self, span: Span, def_id: DefId) -> SubstsRef<'tcx> {
         Substs::for_item(self.tcx, def_id, |param, _| self.var_for_def(span, param))
     }
 

src/librustc/infer/opaque_types/mod.rs

@@ -9,7 +9,7 @@ use crate::traits::{self, PredicateObligation};
 use crate::ty::{self, Ty, TyCtxt, GenericParamDefKind};
 use crate::ty::fold::{BottomUpFolder, TypeFoldable, TypeFolder};
 use crate::ty::outlives::Component;
-use crate::ty::subst::{Kind, Substs, UnpackedKind};
+use crate::ty::subst::{Kind, Substs, SubstsRef, UnpackedKind};
 use crate::util::nodemap::DefIdMap;
 
 pub type OpaqueTypeMap<'tcx> = DefIdMap<OpaqueTypeDecl<'tcx>>;
@@ -30,7 +30,7 @@ pub struct OpaqueTypeDecl<'tcx> {
     ///     fn foo<'a, 'b, T>() -> Foo<'a, T>
     ///
     /// then `substs` would be `['a, T]`.
-    pub substs: &'tcx Substs<'tcx>,
+    pub substs: SubstsRef<'tcx>,
 
     /// The type variable that represents the value of the abstract type
     /// that we require. In other words, after we compile this function,
@@ -740,7 +740,7 @@ impl<'a, 'gcx, 'tcx> Instantiator<'a, 'gcx, 'tcx> {
         &mut self,
         ty: Ty<'tcx>,
         def_id: DefId,
-        substs: &'tcx Substs<'tcx>,
+        substs: SubstsRef<'tcx>,
     ) -> Ty<'tcx> {
         let infcx = self.infcx;
         let tcx = infcx.tcx;

src/librustc/middle/exported_symbols.rs

@@ -5,7 +5,7 @@ use rustc_data_structures::stable_hasher::{StableHasher, HashStable,
 use std::cmp;
 use std::mem;
 use crate::ty;
-use crate::ty::subst::Substs;
+use crate::ty::subst::SubstsRef;
 
 /// The SymbolExportLevel of a symbols specifies from which kinds of crates
 /// the symbol will be exported. `C` symbols will be exported from any
@@ -33,7 +33,7 @@ impl SymbolExportLevel {
 #[derive(Eq, PartialEq, Debug, Copy, Clone, RustcEncodable, RustcDecodable)]
 pub enum ExportedSymbol<'tcx> {
     NonGeneric(DefId),
-    Generic(DefId, &'tcx Substs<'tcx>),
+    Generic(DefId, SubstsRef<'tcx>),
     NoDefId(ty::SymbolName),
 }
 

src/librustc/mir/mod.rs

@@ -27,7 +27,7 @@ use syntax::ast::{self, Name};
 use syntax::symbol::InternedString;
 use syntax_pos::{Span, DUMMY_SP};
 use crate::ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
-use crate::ty::subst::{Subst, Substs};
+use crate::ty::subst::{Subst, SubstsRef};
 use crate::ty::layout::VariantIdx;
 use crate::ty::{
     self, AdtDef, CanonicalUserTypeAnnotations, ClosureSubsts, GeneratorSubsts, Region, Ty, TyCtxt,
@@ -2151,7 +2151,7 @@ impl<'tcx> Operand<'tcx> {
     pub fn function_handle<'a>(
         tcx: TyCtxt<'a, 'tcx, 'tcx>,
         def_id: DefId,
-        substs: &'tcx Substs<'tcx>,
+        substs: SubstsRef<'tcx>,
         span: Span,
     ) -> Self {
         let ty = tcx.type_of(def_id).subst(tcx, substs);
@@ -2247,7 +2247,7 @@ pub enum AggregateKind<'tcx> {
     Adt(
         &'tcx AdtDef,
         VariantIdx,
-        &'tcx Substs<'tcx>,
+        SubstsRef<'tcx>,
         Option<UserTypeAnnotationIndex>,
         Option<usize>,
     ),

src/librustc/mir/tcx.rs

@@ -4,7 +4,7 @@
  */
 
 use crate::mir::*;
-use crate::ty::subst::{Subst, Substs};
+use crate::ty::subst::{Subst, SubstsRef};
 use crate::ty::{self, AdtDef, Ty, TyCtxt};
 use crate::ty::layout::VariantIdx;
 use crate::hir;
@@ -17,7 +17,7 @@ pub enum PlaceTy<'tcx> {
 
     /// Downcast to a particular variant of an enum.
     Downcast { adt_def: &'tcx AdtDef,
-               substs: &'tcx Substs<'tcx>,
+               substs: SubstsRef<'tcx>,
                variant_index: VariantIdx },
 }
 

src/librustc/mir/visit.rs

@@ -1,5 +1,5 @@
 use crate::hir::def_id::DefId;
-use crate::ty::subst::Substs;
+use crate::ty::subst::SubstsRef;
 use crate::ty::{CanonicalUserTypeAnnotation, ClosureSubsts, GeneratorSubsts, Region, Ty};
 use crate::mir::*;
 use syntax_pos::Span;
@@ -238,7 +238,7 @@ macro_rules! make_mir_visitor {
             }
 
             fn visit_substs(&mut self,
-                            substs: & $($mutability)? &'tcx Substs<'tcx>,
+                            substs: & $($mutability)? SubstsRef<'tcx>,
                             _: Location) {
                 self.super_substs(substs);
             }
@@ -889,7 +889,7 @@ macro_rules! make_mir_visitor {
             fn super_const(&mut self, _const: & $($mutability)? &'tcx ty::LazyConst<'tcx>) {
             }
 
-            fn super_substs(&mut self, _substs: & $($mutability)? &'tcx Substs<'tcx>) {
+            fn super_substs(&mut self, _substs: & $($mutability)? SubstsRef<'tcx>) {
             }
 
             fn super_generator_substs(&mut self,

src/librustc/traits/mod.rs

@@ -29,7 +29,7 @@ use crate::mir::interpret::ErrorHandled;
 use rustc_data_structures::sync::Lrc;
 use syntax::ast;
 use syntax_pos::{Span, DUMMY_SP};
-use crate::ty::subst::Substs;
+use crate::ty::subst::{Substs, SubstsRef};
 use crate::ty::{self, AdtKind, List, Ty, TyCtxt, GenericParamDefKind, ToPredicate};
 use crate::ty::error::{ExpectedFound, TypeError};
 use crate::ty::fold::{TypeFolder, TypeFoldable, TypeVisitor};
@@ -565,7 +565,7 @@ pub enum Vtable<'tcx, N> {
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable)]
 pub struct VtableImplData<'tcx, N> {
     pub impl_def_id: DefId,
-    pub substs: &'tcx Substs<'tcx>,
+    pub substs: SubstsRef<'tcx>,
     pub nested: Vec<N>
 }
 
@@ -622,7 +622,7 @@ pub struct VtableFnPointerData<'tcx, N> {
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable)]
 pub struct VtableTraitAliasData<'tcx, N> {
     pub alias_def_id: DefId,
-    pub substs: &'tcx Substs<'tcx>,
+    pub substs: SubstsRef<'tcx>,
     pub nested: Vec<N>,
 }
 
@@ -963,7 +963,7 @@ fn normalize_and_test_predicates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 }
 
 fn substitute_normalize_and_test_predicates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                                                      key: (DefId, &'tcx Substs<'tcx>))
+                                                      key: (DefId, SubstsRef<'tcx>))
                                                       -> bool
 {
     debug!("substitute_normalize_and_test_predicates(key={:?})",
@@ -983,7 +983,7 @@ fn substitute_normalize_and_test_predicates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx
 fn vtable_methods<'a, 'tcx>(
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     trait_ref: ty::PolyTraitRef<'tcx>)
-    -> Lrc<Vec<Option<(DefId, &'tcx Substs<'tcx>)>>>
+    -> Lrc<Vec<Option<(DefId, SubstsRef<'tcx>)>>>
 {
     debug!("vtable_methods({:?})", trait_ref);
 

src/librustc/traits/select.rs

@@ -34,7 +34,7 @@ use crate::middle::lang_items;
 use crate::mir::interpret::GlobalId;
 use crate::ty::fast_reject;
 use crate::ty::relate::TypeRelation;
-use crate::ty::subst::{Subst, Substs};
+use crate::ty::subst::{Subst, Substs, SubstsRef};
 use crate::ty::{self, ToPolyTraitRef, ToPredicate, Ty, TyCtxt, TypeFoldable};
 
 use crate::hir;
@@ -2944,7 +2944,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
     fn vtable_impl(
         &mut self,
         impl_def_id: DefId,
-        mut substs: Normalized<'tcx, &'tcx Substs<'tcx>>,
+        mut substs: Normalized<'tcx, SubstsRef<'tcx>>,
         cause: ObligationCause<'tcx>,
         recursion_depth: usize,
         param_env: ty::ParamEnv<'tcx>,
@@ -3538,7 +3538,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         impl_def_id: DefId,
         obligation: &TraitObligation<'tcx>,
         snapshot: &CombinedSnapshot<'_, 'tcx>,
-    ) -> Normalized<'tcx, &'tcx Substs<'tcx>> {
+    ) -> Normalized<'tcx, SubstsRef<'tcx>> {
         match self.match_impl(impl_def_id, obligation, snapshot) {
             Ok(substs) => substs,
             Err(()) => {
@@ -3556,7 +3556,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         impl_def_id: DefId,
         obligation: &TraitObligation<'tcx>,
         snapshot: &CombinedSnapshot<'_, 'tcx>,
-    ) -> Result<Normalized<'tcx, &'tcx Substs<'tcx>>, ()> {
+    ) -> Result<Normalized<'tcx, SubstsRef<'tcx>>, ()> {
         let impl_trait_ref = self.tcx().impl_trait_ref(impl_def_id).unwrap();
 
         // Before we create the substitutions and everything, first

src/librustc/traits/specialize/mod.rs

@@ -20,7 +20,7 @@ use rustc_data_structures::sync::Lrc;
 use syntax_pos::DUMMY_SP;
 use crate::traits::select::IntercrateAmbiguityCause;
 use crate::ty::{self, TyCtxt, TypeFoldable};
-use crate::ty::subst::{Subst, Substs};
+use crate::ty::subst::{Subst, Substs, SubstsRef};
 
 use super::{SelectionContext, FulfillmentContext};
 use super::util::impl_trait_ref_and_oblig;
@@ -73,9 +73,9 @@ pub struct OverlapError {
 pub fn translate_substs<'a, 'gcx, 'tcx>(infcx: &InferCtxt<'a, 'gcx, 'tcx>,
                                         param_env: ty::ParamEnv<'tcx>,
                                         source_impl: DefId,
-                                        source_substs: &'tcx Substs<'tcx>,
+                                        source_substs: SubstsRef<'tcx>,
                                         target_node: specialization_graph::Node)
-                                        -> &'tcx Substs<'tcx> {
+                                        -> SubstsRef<'tcx> {
     debug!("translate_substs({:?}, {:?}, {:?}, {:?})",
            param_env, source_impl, source_substs, target_node);
     let source_trait_ref = infcx.tcx
@@ -114,9 +114,9 @@ pub fn find_associated_item<'a, 'tcx>(
     tcx: TyCtxt<'a, 'tcx, 'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     item: &ty::AssociatedItem,
-    substs: &'tcx Substs<'tcx>,
+    substs: SubstsRef<'tcx>,
     impl_data: &super::VtableImplData<'tcx, ()>,
-) -> (DefId, &'tcx Substs<'tcx>) {
+) -> (DefId, SubstsRef<'tcx>) {
     debug!("find_associated_item({:?}, {:?}, {:?}, {:?})",
            param_env, item, substs, impl_data);
     assert!(!substs.needs_infer());
@@ -214,7 +214,7 @@ fn fulfill_implication<'a, 'gcx, 'tcx>(infcx: &InferCtxt<'a, 'gcx, 'tcx>,
                                        param_env: ty::ParamEnv<'tcx>,
                                        source_trait_ref: ty::TraitRef<'tcx>,
                                        target_impl: DefId)
-                                       -> Result<&'tcx Substs<'tcx>, ()> {
+                                       -> Result<SubstsRef<'tcx>, ()> {
     debug!("fulfill_implication({:?}, trait_ref={:?} |- {:?} applies)",
            param_env, source_trait_ref, target_impl);
 

src/librustc/ty/adjustment.rs

@@ -1,7 +1,7 @@
 use crate::hir;
 use crate::hir::def_id::DefId;
 use crate::ty::{self, Ty, TyCtxt};
-use crate::ty::subst::Substs;
+use crate::ty::subst::SubstsRef;
 
 
 /// Represents coercing a value to a different type of value.
@@ -98,7 +98,7 @@ pub struct OverloadedDeref<'tcx> {
 
 impl<'a, 'gcx, 'tcx> OverloadedDeref<'tcx> {
     pub fn method_call(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>, source: Ty<'tcx>)
-                       -> (DefId, &'tcx Substs<'tcx>) {
+                       -> (DefId, SubstsRef<'tcx>) {
         let trait_def_id = match self.mutbl {
             hir::MutImmutable => tcx.lang_items().deref_trait(),
             hir::MutMutable => tcx.lang_items().deref_mut_trait()

src/librustc/ty/codec.rs

@@ -13,7 +13,7 @@ use crate::rustc_serialize::{Decodable, Decoder, Encoder, Encodable, opaque};
 use std::hash::Hash;
 use std::intrinsics;
 use crate::ty::{self, Ty, TyCtxt};
-use crate::ty::subst::Substs;
+use crate::ty::subst::SubstsRef;
 use crate::mir::interpret::Allocation;
 
 /// The shorthand encoding uses an enum's variant index `usize`
@@ -185,7 +185,7 @@ pub fn decode_predicates<'a, 'tcx, D>(decoder: &mut D)
 }
 
 #[inline]
-pub fn decode_substs<'a, 'tcx, D>(decoder: &mut D) -> Result<&'tcx Substs<'tcx>, D::Error>
+pub fn decode_substs<'a, 'tcx, D>(decoder: &mut D) -> Result<SubstsRef<'tcx>, D::Error>
     where D: TyDecoder<'a, 'tcx>,
           'tcx: 'a,
 {
@@ -281,7 +281,7 @@ macro_rules! implement_ty_decoder {
             use $crate::infer::canonical::CanonicalVarInfos;
             use $crate::ty;
             use $crate::ty::codec::*;
-            use $crate::ty::subst::Substs;
+            use $crate::ty::subst::SubstsRef;
             use $crate::hir::def_id::{CrateNum};
             use crate::rustc_serialize::{Decoder, SpecializedDecoder};
             use std::borrow::Cow;
@@ -344,9 +344,9 @@ macro_rules! implement_ty_decoder {
                 }
             }
 
-            impl<$($typaram),*> SpecializedDecoder<&'tcx Substs<'tcx>>
+            impl<$($typaram),*> SpecializedDecoder<SubstsRef<'tcx>>
             for $DecoderName<$($typaram),*> {
-                fn specialized_decode(&mut self) -> Result<&'tcx Substs<'tcx>, Self::Error> {
+                fn specialized_decode(&mut self) -> Result<SubstsRef<'tcx>, Self::Error> {
                     decode_substs(self)
                 }
             }