src/librustc/ty/query/keys.rs

   1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Defines the set of legal keys that can be used in queries.
  12
  13 use infer::canonical::Canonical;
  14 use hir::def_id::{CrateNum, DefId, LOCAL_CRATE, DefIndex};
  15 use traits;
  16 use ty::{self, Ty, TyCtxt};
  17 use ty::subst::Substs;
  18 use ty::fast_reject::SimplifiedType;
  19 use mir;
  20
  21 use std::fmt::Debug;
  22 use std::hash::Hash;
  23 use syntax_pos::{Span, DUMMY_SP};
  24 use syntax_pos::symbol::InternedString;
  25
  26 /// The `Key` trait controls what types can legally be used as the key
  27 /// for a query.
  28 pub(super) trait Key: Clone + Hash + Eq + Debug {
  29     /// Given an instance of this key, what crate is it referring to?
  30     /// This is used to find the provider.
  31     fn query_crate(&self) -> CrateNum;
  32
  33     /// In the event that a cycle occurs, if no explicit span has been
  34     /// given for a query with key `self`, what span should we use?
  35     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span;
  36 }
  37
  38 impl<'tcx> Key for ty::InstanceDef<'tcx> {
  39     fn query_crate(&self) -> CrateNum {
  40         LOCAL_CRATE
  41     }
  42
  43     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
  44         tcx.def_span(self.def_id())
  45     }
  46 }
  47
  48 impl<'tcx> Key for ty::Instance<'tcx> {
  49     fn query_crate(&self) -> CrateNum {
  50         LOCAL_CRATE
  51     }
  52
  53     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
  54         tcx.def_span(self.def_id())
  55     }
  56 }
  57
  58 impl<'tcx> Key for mir::interpret::GlobalId<'tcx> {
  59     fn query_crate(&self) -> CrateNum {
  60         self.instance.query_crate()
  61     }
  62
  63     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
  64         self.instance.default_span(tcx)
  65     }
  66 }
  67
  68 impl Key for CrateNum {
  69     fn query_crate(&self) -> CrateNum {
  70         *self
  71     }
  72     fn default_span(&self, _: TyCtxt<'_, '_, '_>) -> Span {
  73         DUMMY_SP
  74     }
  75 }
  76
  77 impl Key for DefIndex {
  78     fn query_crate(&self) -> CrateNum {
  79         LOCAL_CRATE
  80     }
  81     fn default_span(&self, _tcx: TyCtxt<'_, '_, '_>) -> Span {
  82         DUMMY_SP
  83     }
  84 }
  85
  86 impl Key for DefId {
  87     fn query_crate(&self) -> CrateNum {
  88         self.krate
  89     }
  90     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
  91         tcx.def_span(*self)
  92     }
  93 }
  94
  95 impl Key for (DefId, DefId) {
  96     fn query_crate(&self) -> CrateNum {
  97         self.0.krate
  98     }
  99     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
 100         self.1.default_span(tcx)
 101     }
 102 }
 103
 104 impl Key for (CrateNum, DefId) {
 105     fn query_crate(&self) -> CrateNum {
 106         self.0
 107     }
 108     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
 109         self.1.default_span(tcx)
 110     }
 111 }
 112
 113 impl Key for (DefId, SimplifiedType) {
 114     fn query_crate(&self) -> CrateNum {
 115         self.0.krate
 116     }
 117     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
 118         self.0.default_span(tcx)
 119     }
 120 }
 121
 122 impl<'tcx> Key for (DefId, &'tcx Substs<'tcx>) {
 123     fn query_crate(&self) -> CrateNum {
 124         self.0.krate
 125     }
 126     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
 127         self.0.default_span(tcx)
 128     }
 129 }
 130
 131 impl<'tcx> Key for (ty::ParamEnv<'tcx>, ty::PolyTraitRef<'tcx>) {
 132     fn query_crate(&self) -> CrateNum {
 133         self.1.def_id().krate
 134     }
 135     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
 136         tcx.def_span(self.1.def_id())
 137     }
 138 }
 139
 140 impl<'tcx> Key for ty::PolyTraitRef<'tcx>{
 141     fn query_crate(&self) -> CrateNum {
 142         self.def_id().krate
 143     }
 144     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
 145         tcx.def_span(self.def_id())
 146     }
 147 }
 148
 149 impl<'tcx> Key for &'tcx ty::Const<'tcx> {
 150     fn query_crate(&self) -> CrateNum {
 151         LOCAL_CRATE
 152     }
 153     fn default_span(&self, _: TyCtxt<'_, '_, '_>) -> Span {
 154         DUMMY_SP
 155     }
 156 }
 157
 158 impl<'tcx> Key for Ty<'tcx> {
 159     fn query_crate(&self) -> CrateNum {
 160         LOCAL_CRATE
 161     }
 162     fn default_span(&self, _: TyCtxt<'_, '_, '_>) -> Span {
 163         DUMMY_SP
 164     }
 165 }
 166
 167 impl<'tcx> Key for ty::ParamEnv<'tcx> {
 168     fn query_crate(&self) -> CrateNum {
 169         LOCAL_CRATE
 170     }
 171     fn default_span(&self, _: TyCtxt<'_, '_, '_>) -> Span {
 172         DUMMY_SP
 173     }
 174 }
 175
 176 impl<'tcx, T: Key> Key for ty::ParamEnvAnd<'tcx, T> {
 177     fn query_crate(&self) -> CrateNum {
 178         self.value.query_crate()
 179     }
 180     fn default_span(&self, tcx: TyCtxt<'_, '_, '_>) -> Span {
 181         self.value.default_span(tcx)
 182     }
 183 }
 184
 185 impl<'tcx> Key for traits::Environment<'tcx> {
 186     fn query_crate(&self) -> CrateNum {
 187         LOCAL_CRATE
 188     }
 189     fn default_span(&self, _: TyCtxt<'_, '_, '_>) -> Span {
 190         DUMMY_SP
 191     }
 192 }
 193
 194 impl Key for InternedString {
 195     fn query_crate(&self) -> CrateNum {
 196         LOCAL_CRATE
 197     }
 198     fn default_span(&self, _tcx: TyCtxt<'_, '_, '_>) -> Span {
 199         DUMMY_SP
 200     }
 201 }
 202
 203 /// Canonical query goals correspond to abstract trait operations that
 204 /// are not tied to any crate in particular.
 205 impl<'tcx, T> Key for Canonical<'tcx, T>
 206 where
 207     T: Debug + Hash + Clone + Eq,
 208 {
 209     fn query_crate(&self) -> CrateNum {
 210         LOCAL_CRATE
 211     }
 212
 213     fn default_span(&self, _tcx: TyCtxt<'_, '_, '_>) -> Span {
 214         DUMMY_SP
 215     }
 216 }