src/librustc/hir/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 hir::def_id::DefId;
  12 use util::nodemap::NodeMap;
  13 use syntax::ast;
  14 use syntax::ext::base::MacroKind;
  15 use syntax_pos::Span;
  16 use hir;
  17
  18 #[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
  19 pub enum CtorKind {
  20     /// Constructor function automatically created by a tuple struct/variant.
  21     Fn,
  22     /// Constructor constant automatically created by a unit struct/variant.
  23     Const,
  24     /// Unusable name in value namespace created by a struct variant.
  25     Fictive,
  26 }
  27
  28 #[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
  29 pub enum Def {
  30     // Type namespace
  31     Mod(DefId),
  32     Struct(DefId), // DefId refers to NodeId of the struct itself
  33     Union(DefId),
  34     Enum(DefId),
  35     Variant(DefId),
  36     Trait(DefId),
  37     TyAlias(DefId),
  38     AssociatedTy(DefId),
  39     PrimTy(hir::PrimTy),
  40     TyParam(DefId),
  41     SelfTy(Option<DefId> /* trait */, Option<DefId> /* impl */),
  42
  43     // Value namespace
  44     Fn(DefId),
  45     Const(DefId),
  46     Static(DefId, bool /* is_mutbl */),
  47     StructCtor(DefId, CtorKind), // DefId refers to NodeId of the struct's constructor
  48     VariantCtor(DefId, CtorKind),
  49     Method(DefId),
  50     AssociatedConst(DefId),
  51     Local(DefId),
  52     Upvar(DefId,        // def id of closed over local
  53           usize,        // index in the freevars list of the closure
  54           ast::NodeId), // expr node that creates the closure
  55     Label(ast::NodeId),
  56
  57     // Macro namespace
  58     Macro(DefId, MacroKind),
  59
  60     GlobalAsm(DefId),
  61
  62     // Both namespaces
  63     Err,
  64 }
  65
  66 /// The result of resolving a path before lowering to HIR.
  67 /// `base_def` is definition of resolved part of the
  68 /// path, `unresolved_segments` is the number of unresolved
  69 /// segments.
  70 ///     module::Type::AssocX::AssocY::MethodOrAssocType
  71 ///     ^~~~~~~~~~~~  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  72 ///     base_def      unresolved_segments = 3
  73 ///
  74 ///     <T as Trait>::AssocX::AssocY::MethodOrAssocType
  75 ///           ^~~~~~~~~~~~~~  ^~~~~~~~~~~~~~~~~~~~~~~~~
  76 ///           base_def        unresolved_segments = 2
  77 #[derive(Copy, Clone, Debug)]
  78 pub struct PathResolution {
  79     base_def: Def,
  80     unresolved_segments: usize,
  81 }
  82
  83 impl PathResolution {
  84     pub fn new(def: Def) -> Self {
  85         PathResolution { base_def: def, unresolved_segments: 0 }
  86     }
  87
  88     pub fn with_unresolved_segments(def: Def, mut unresolved_segments: usize) -> Self {
  89         if def == Def::Err { unresolved_segments = 0 }
  90         PathResolution { base_def: def, unresolved_segments: unresolved_segments }
  91     }
  92
  93     #[inline]
  94     pub fn base_def(&self) -> Def {
  95         self.base_def
  96     }
  97
  98     #[inline]
  99     pub fn unresolved_segments(&self) -> usize {
 100         self.unresolved_segments
 101     }
 102
 103     pub fn kind_name(&self) -> &'static str {
 104         if self.unresolved_segments != 0 {
 105             "associated item"
 106         } else {
 107             self.base_def.kind_name()
 108         }
 109     }
 110 }
 111
 112 /// Definition mapping
 113 pub type DefMap = NodeMap<PathResolution>;
 114
 115 /// This is the replacement export map. It maps a module to all of the exports
 116 /// within.
 117 pub type ExportMap = NodeMap<Vec<Export>>;
 118
 119 #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable)]
 120 pub struct Export {
 121     /// The name of the target.
 122     pub ident: ast::Ident,
 123     /// The definition of the target.
 124     pub def: Def,
 125     /// The span of the target definition.
 126     pub span: Span,
 127 }
 128
 129 impl CtorKind {
 130     pub fn from_ast(vdata: &ast::VariantData) -> CtorKind {
 131         match *vdata {
 132             ast::VariantData::Tuple(..) => CtorKind::Fn,
 133             ast::VariantData::Unit(..) => CtorKind::Const,
 134             ast::VariantData::Struct(..) => CtorKind::Fictive,
 135         }
 136     }
 137     pub fn from_hir(vdata: &hir::VariantData) -> CtorKind {
 138         match *vdata {
 139             hir::VariantData::Tuple(..) => CtorKind::Fn,
 140             hir::VariantData::Unit(..) => CtorKind::Const,
 141             hir::VariantData::Struct(..) => CtorKind::Fictive,
 142         }
 143     }
 144 }
 145
 146 impl Def {
 147     pub fn def_id(&self) -> DefId {
 148         match *self {
 149             Def::Fn(id) | Def::Mod(id) | Def::Static(id, _) |
 150             Def::Variant(id) | Def::VariantCtor(id, ..) | Def::Enum(id) | Def::TyAlias(id) |
 151             Def::AssociatedTy(id) | Def::TyParam(id) | Def::Struct(id) | Def::StructCtor(id, ..) |
 152             Def::Union(id) | Def::Trait(id) | Def::Method(id) | Def::Const(id) |
 153             Def::AssociatedConst(id) | Def::Local(id) | Def::Upvar(id, ..) | Def::Macro(id, ..) |
 154             Def::GlobalAsm(id) => {
 155                 id
 156             }
 157
 158             Def::Label(..)  |
 159             Def::PrimTy(..) |
 160             Def::SelfTy(..) |
 161             Def::Err => {
 162                 bug!("attempted .def_id() on invalid def: {:?}", self)
 163             }
 164         }
 165     }
 166
 167     /// A human readable kind name
 168     pub fn kind_name(&self) -> &'static str {
 169         match *self {
 170             Def::Fn(..) => "function",
 171             Def::Mod(..) => "module",
 172             Def::Static(..) => "static",
 173             Def::Variant(..) => "variant",
 174             Def::VariantCtor(.., CtorKind::Fn) => "tuple variant",
 175             Def::VariantCtor(.., CtorKind::Const) => "unit variant",
 176             Def::VariantCtor(.., CtorKind::Fictive) => "struct variant",
 177             Def::Enum(..) => "enum",
 178             Def::TyAlias(..) => "type alias",
 179             Def::AssociatedTy(..) => "associated type",
 180             Def::Struct(..) => "struct",
 181             Def::StructCtor(.., CtorKind::Fn) => "tuple struct",
 182             Def::StructCtor(.., CtorKind::Const) => "unit struct",
 183             Def::StructCtor(.., CtorKind::Fictive) => bug!("impossible struct constructor"),
 184             Def::Union(..) => "union",
 185             Def::Trait(..) => "trait",
 186             Def::Method(..) => "method",
 187             Def::Const(..) => "constant",
 188             Def::AssociatedConst(..) => "associated constant",
 189             Def::TyParam(..) => "type parameter",
 190             Def::PrimTy(..) => "builtin type",
 191             Def::Local(..) => "local variable",
 192             Def::Upvar(..) => "closure capture",
 193             Def::Label(..) => "label",
 194             Def::SelfTy(..) => "self type",
 195             Def::Macro(..) => "macro",
 196             Def::GlobalAsm(..) => "global asm",
 197             Def::Err => "unresolved item",
 198         }
 199     }
 200 }