src/librustc/ty/maps/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 hir::def_id::{CrateNum, DefId, LOCAL_CRATE, DefIndex};
  14 use mir::transform::{MirSuite, MirPassIndex};
  15 use ty::{self, Ty, TyCtxt};
  16 use ty::subst::Substs;
  17 use ty::fast_reject::SimplifiedType;
  18
  19 use std::fmt::Debug;
  20 use std::hash::Hash;
  21 use syntax_pos::{Span, DUMMY_SP};
  22 use syntax_pos::symbol::InternedString;
  23
  24 /// The `Key` trait controls what types can legally be used as the key
  25 /// for a query.
  26 pub trait Key: Clone + Hash + Eq + Debug {
  27     /// Given an instance of this key, what crate is it referring to?
  28     /// This is used to find the provider.
  29     fn map_crate(&self) -> CrateNum;
  30
  31     /// In the event that a cycle occurs, if no explicit span has been
  32     /// given for a query with key `self`, what span should we use?
  33     fn default_span(&self, tcx: TyCtxt) -> Span;
  34 }
  35
  36 impl<'tcx> Key for ty::InstanceDef<'tcx> {
  37     fn map_crate(&self) -> CrateNum {
  38         LOCAL_CRATE
  39     }
  40
  41     fn default_span(&self, tcx: TyCtxt) -> Span {
  42         tcx.def_span(self.def_id())
  43     }
  44 }
  45
  46 impl<'tcx> Key for ty::Instance<'tcx> {
  47     fn map_crate(&self) -> CrateNum {
  48         LOCAL_CRATE
  49     }
  50
  51     fn default_span(&self, tcx: TyCtxt) -> Span {
  52         tcx.def_span(self.def_id())
  53     }
  54 }
  55
  56 impl Key for CrateNum {
  57     fn map_crate(&self) -> CrateNum {
  58         *self
  59     }
  60     fn default_span(&self, _: TyCtxt) -> Span {
  61         DUMMY_SP
  62     }
  63 }
  64
  65 impl Key for DefIndex {
  66     fn map_crate(&self) -> CrateNum {
  67         LOCAL_CRATE
  68     }
  69     fn default_span(&self, _tcx: TyCtxt) -> Span {
  70         DUMMY_SP
  71     }
  72 }
  73
  74 impl Key for DefId {
  75     fn map_crate(&self) -> CrateNum {
  76         self.krate
  77     }
  78     fn default_span(&self, tcx: TyCtxt) -> Span {
  79         tcx.def_span(*self)
  80     }
  81 }
  82
  83 impl Key for (DefId, DefId) {
  84     fn map_crate(&self) -> CrateNum {
  85         self.0.krate
  86     }
  87     fn default_span(&self, tcx: TyCtxt) -> Span {
  88         self.1.default_span(tcx)
  89     }
  90 }
  91
  92 impl Key for (CrateNum, DefId) {
  93     fn map_crate(&self) -> CrateNum {
  94         self.0
  95     }
  96     fn default_span(&self, tcx: TyCtxt) -> Span {
  97         self.1.default_span(tcx)
  98     }
  99 }
 100
 101 impl Key for (DefId, SimplifiedType) {
 102     fn map_crate(&self) -> CrateNum {
 103         self.0.krate
 104     }
 105     fn default_span(&self, tcx: TyCtxt) -> Span {
 106         self.0.default_span(tcx)
 107     }
 108 }
 109
 110 impl<'tcx> Key for (DefId, &'tcx Substs<'tcx>) {
 111     fn map_crate(&self) -> CrateNum {
 112         self.0.krate
 113     }
 114     fn default_span(&self, tcx: TyCtxt) -> Span {
 115         self.0.default_span(tcx)
 116     }
 117 }
 118
 119 impl Key for (MirSuite, DefId) {
 120     fn map_crate(&self) -> CrateNum {
 121         self.1.map_crate()
 122     }
 123     fn default_span(&self, tcx: TyCtxt) -> Span {
 124         self.1.default_span(tcx)
 125     }
 126 }
 127
 128 impl Key for (MirSuite, MirPassIndex, DefId) {
 129     fn map_crate(&self) -> CrateNum {
 130         self.2.map_crate()
 131     }
 132     fn default_span(&self, tcx: TyCtxt) -> Span {
 133         self.2.default_span(tcx)
 134     }
 135 }
 136
 137 impl<'tcx> Key for Ty<'tcx> {
 138     fn map_crate(&self) -> CrateNum {
 139         LOCAL_CRATE
 140     }
 141     fn default_span(&self, _: TyCtxt) -> Span {
 142         DUMMY_SP
 143     }
 144 }
 145
 146 impl<'tcx, T: Key> Key for ty::ParamEnvAnd<'tcx, T> {
 147     fn map_crate(&self) -> CrateNum {
 148         self.value.map_crate()
 149     }
 150     fn default_span(&self, tcx: TyCtxt) -> Span {
 151         self.value.default_span(tcx)
 152     }
 153 }
 154
 155 impl Key for InternedString {
 156     fn map_crate(&self) -> CrateNum {
 157         LOCAL_CRATE
 158     }
 159     fn default_span(&self, _tcx: TyCtxt) -> Span {
 160         DUMMY_SP
 161     }
 162 }