src/librustc/middle/def.rs

   1 // Copyright 2014 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 use middle::def_id::DefId;
  12 use middle::subst::ParamSpace;
  13 use util::nodemap::NodeMap;
  14 use syntax::ast;
  15 use rustc_front::hir;
  16
  17 #[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
  18 pub enum Def {
  19     Fn(DefId),
  20     SelfTy(Option<DefId>,                    // trait id
  21               Option<(ast::NodeId, ast::NodeId)>),   // (impl id, self type id)
  22     Mod(DefId),
  23     ForeignMod(DefId),
  24     Static(DefId, bool /* is_mutbl */),
  25     Const(DefId),
  26     AssociatedConst(DefId),
  27     Local(DefId, // def id of variable
  28              ast::NodeId), // node id of variable
  29     Variant(DefId /* enum */, DefId /* variant */),
  30     Enum(DefId),
  31     TyAlias(DefId),
  32     AssociatedTy(DefId /* trait */, DefId),
  33     Trait(DefId),
  34     PrimTy(hir::PrimTy),
  35     TyParam(ParamSpace, u32, DefId, ast::Name),
  36     Upvar(DefId,        // def id of closed over local
  37              ast::NodeId,  // node id of closed over local
  38              usize,        // index in the freevars list of the closure
  39              ast::NodeId), // expr node that creates the closure
  40
  41     // If Def::Struct lives in type namespace it denotes a struct item and its DefId refers
  42     // to NodeId of the struct itself.
  43     // If Def::Struct lives in value namespace (e.g. tuple struct, unit struct expressions)
  44     // it denotes a constructor and its DefId refers to NodeId of the struct's constructor.
  45     Struct(DefId),
  46     Label(ast::NodeId),
  47     Method(DefId),
  48     Err,
  49 }
  50
  51 /// The result of resolving a path.
  52 /// Before type checking completes, `depth` represents the number of
  53 /// trailing segments which are yet unresolved. Afterwards, if there
  54 /// were no errors, all paths should be fully resolved, with `depth`
  55 /// set to `0` and `base_def` representing the final resolution.
  56 ///
  57 ///     module::Type::AssocX::AssocY::MethodOrAssocType
  58 ///     ^~~~~~~~~~~~  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  59 ///     base_def      depth = 3
  60 ///
  61 ///     <T as Trait>::AssocX::AssocY::MethodOrAssocType
  62 ///           ^~~~~~~~~~~~~~  ^~~~~~~~~~~~~~~~~~~~~~~~~
  63 ///           base_def        depth = 2
  64 #[derive(Copy, Clone, Debug)]
  65 pub struct PathResolution {
  66     pub base_def: Def,
  67     pub depth: usize
  68 }
  69
  70 impl PathResolution {
  71     /// Get the definition, if fully resolved, otherwise panic.
  72     pub fn full_def(&self) -> Def {
  73         if self.depth != 0 {
  74             panic!("path not fully resolved: {:?}", self);
  75         }
  76         self.base_def
  77     }
  78
  79     /// Get the DefId, if fully resolved, otherwise panic.
  80     pub fn def_id(&self) -> DefId {
  81         self.full_def().def_id()
  82     }
  83
  84     pub fn new(base_def: Def,
  85                depth: usize)
  86                -> PathResolution {
  87         PathResolution {
  88             base_def: base_def,
  89             depth: depth,
  90         }
  91     }
  92 }
  93
  94 // Definition mapping
  95 pub type DefMap = NodeMap<PathResolution>;
  96 // This is the replacement export map. It maps a module to all of the exports
  97 // within.
  98 pub type ExportMap = NodeMap<Vec<Export>>;
  99
 100 #[derive(Copy, Clone)]
 101 pub struct Export {
 102     pub name: ast::Name,    // The name of the target.
 103     pub def_id: DefId, // The definition of the target.
 104 }
 105
 106 impl Def {
 107     pub fn var_id(&self) -> ast::NodeId {
 108         match *self {
 109             Def::Local(_, id) |
 110             Def::Upvar(_, id, _, _) => {
 111                 id
 112             }
 113
 114             Def::Fn(..) | Def::Mod(..) | Def::ForeignMod(..) | Def::Static(..) |
 115             Def::Variant(..) | Def::Enum(..) | Def::TyAlias(..) | Def::AssociatedTy(..) |
 116             Def::TyParam(..) | Def::Struct(..) | Def::Trait(..) |
 117             Def::Method(..) | Def::Const(..) | Def::AssociatedConst(..) |
 118             Def::PrimTy(..) | Def::Label(..) | Def::SelfTy(..) | Def::Err => {
 119                 panic!("attempted .var_id() on invalid {:?}", self)
 120             }
 121         }
 122     }
 123
 124     pub fn def_id(&self) -> DefId {
 125         match *self {
 126             Def::Fn(id) | Def::Mod(id) | Def::ForeignMod(id) | Def::Static(id, _) |
 127             Def::Variant(_, id) | Def::Enum(id) | Def::TyAlias(id) | Def::AssociatedTy(_, id) |
 128             Def::TyParam(_, _, id, _) | Def::Struct(id) | Def::Trait(id) |
 129             Def::Method(id) | Def::Const(id) | Def::AssociatedConst(id) |
 130             Def::Local(id, _) | Def::Upvar(id, _, _, _) => {
 131                 id
 132             }
 133
 134             Def::Label(..)  |
 135             Def::PrimTy(..) |
 136             Def::SelfTy(..) |
 137             Def::Err => {
 138                 panic!("attempted .def_id() on invalid def: {:?}", self)
 139             }
 140         }
 141     }
 142
 143     pub fn variant_def_ids(&self) -> Option<(DefId, DefId)> {
 144         match *self {
 145             Def::Variant(enum_id, var_id) => {
 146                 Some((enum_id, var_id))
 147             }
 148             _ => None
 149         }
 150     }
 151
 152     pub fn kind_name(&self) -> &'static str {
 153         match *self {
 154             Def::Fn(..) => "function",
 155             Def::Mod(..) => "module",
 156             Def::ForeignMod(..) => "foreign module",
 157             Def::Static(..) => "static",
 158             Def::Variant(..) => "variant",
 159             Def::Enum(..) => "enum",
 160             Def::TyAlias(..) => "type",
 161             Def::AssociatedTy(..) => "associated type",
 162             Def::Struct(..) => "struct",
 163             Def::Trait(..) => "trait",
 164             Def::Method(..) => "method",
 165             Def::Const(..) => "const",
 166             Def::AssociatedConst(..) => "associated const",
 167             Def::TyParam(..) => "type parameter",
 168             Def::PrimTy(..) => "builtin type",
 169             Def::Local(..) => "local variable",
 170             Def::Upvar(..) => "closure capture",
 171             Def::Label(..) => "label",
 172             Def::SelfTy(..) => "self type",
 173             Def::Err => "unresolved item",
 174         }
 175     }
 176 }