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.
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.
13 use rustc_data_structures::indexed_vec::Idx;
14 use serialize::{self, Encoder, Decoder};
19 #[derive(Clone, Copy, Eq, Ord, PartialOrd, PartialEq, Hash, Debug)]
20 pub struct CrateNum(u32);
22 impl Idx for CrateNum {
23 fn new(value: usize) -> Self {
24 assert!(value < (u32::MAX) as usize);
25 CrateNum(value as u32)
28 fn index(self) -> usize {
33 /// Item definitions in the currently-compiled crate would have the CrateNum
34 /// LOCAL_CRATE in their DefId.
35 pub const LOCAL_CRATE: CrateNum = CrateNum(0);
37 /// Virtual crate for builtin macros
38 // FIXME(jseyfried): this is also used for custom derives until proc-macro crates get `CrateNum`s.
39 pub const BUILTIN_MACROS_CRATE: CrateNum = CrateNum(u32::MAX);
41 /// A CrateNum value that indicates that something is wrong.
42 pub const INVALID_CRATE: CrateNum = CrateNum(u32::MAX - 1);
45 pub fn new(x: usize) -> CrateNum {
46 assert!(x < (u32::MAX as usize));
50 pub fn from_u32(x: u32) -> CrateNum {
54 pub fn as_usize(&self) -> usize {
58 pub fn as_u32(&self) -> u32 {
63 impl fmt::Display for CrateNum {
64 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
65 fmt::Display::fmt(&self.0, f)
69 impl serialize::UseSpecializedEncodable for CrateNum {
70 fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
75 impl serialize::UseSpecializedDecodable for CrateNum {
76 fn default_decode<D: Decoder>(d: &mut D) -> Result<CrateNum, D::Error> {
77 d.read_u32().map(CrateNum)
81 /// A DefIndex is an index into the hir-map for a crate, identifying a
82 /// particular definition. It should really be considered an interned
83 /// shorthand for a particular DefPath.
85 /// At the moment we are allocating the numerical values of DefIndexes into two
86 /// ranges: the "low" range (starting at zero) and the "high" range (starting at
87 /// DEF_INDEX_HI_START). This allows us to allocate the DefIndexes of all
88 /// item-likes (Items, TraitItems, and ImplItems) into one of these ranges and
89 /// consequently use a simple array for lookup tables keyed by DefIndex and
90 /// known to be densely populated. This is especially important for the HIR map.
92 /// Since the DefIndex is mostly treated as an opaque ID, you probably
93 /// don't have to care about these ranges.
94 #[derive(Clone, Debug, Eq, Ord, PartialOrd, PartialEq, RustcEncodable,
95 RustcDecodable, Hash, Copy)]
96 pub struct DefIndex(u32);
100 pub fn new(x: usize) -> DefIndex {
101 assert!(x < (u32::MAX as usize));
106 pub fn from_u32(x: u32) -> DefIndex {
111 pub fn as_usize(&self) -> usize {
116 pub fn as_u32(&self) -> u32 {
121 pub fn address_space(&self) -> DefIndexAddressSpace {
122 if self.0 < DEF_INDEX_HI_START.0 {
123 DefIndexAddressSpace::Low
125 DefIndexAddressSpace::High
129 /// Converts this DefIndex into a zero-based array index.
130 /// This index is the offset within the given "range" of the DefIndex,
131 /// that is, if the DefIndex is part of the "high" range, the resulting
132 /// index will be (DefIndex - DEF_INDEX_HI_START).
134 pub fn as_array_index(&self) -> usize {
135 (self.0 & !DEF_INDEX_HI_START.0) as usize
139 /// The start of the "high" range of DefIndexes.
140 const DEF_INDEX_HI_START: DefIndex = DefIndex(1 << 31);
142 /// The crate root is always assigned index 0 by the AST Map code,
143 /// thanks to `NodeCollector::new`.
144 pub const CRATE_DEF_INDEX: DefIndex = DefIndex(0);
146 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
147 pub enum DefIndexAddressSpace {
152 impl DefIndexAddressSpace {
154 pub fn index(&self) -> usize {
159 pub fn start(&self) -> usize {
160 self.index() * DEF_INDEX_HI_START.as_usize()
164 /// A DefId identifies a particular *definition*, by combining a crate
165 /// index and a def index.
166 #[derive(Clone, Eq, Ord, PartialOrd, PartialEq, RustcEncodable, RustcDecodable, Hash, Copy)]
172 impl fmt::Debug for DefId {
173 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
174 write!(f, "DefId {{ krate: {:?}, node: {:?}",
175 self.krate, self.index)?;
177 ty::tls::with_opt(|opt_tcx| {
178 if let Some(tcx) = opt_tcx {
179 write!(f, " => {}", tcx.def_path(*self).to_string(tcx))?;
190 /// Make a local `DefId` with the given index.
191 pub fn local(index: DefIndex) -> DefId {
192 DefId { krate: LOCAL_CRATE, index: index }
195 pub fn is_local(&self) -> bool {
196 self.krate == LOCAL_CRATE