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 newtype_index!(CrateNum nopub
24 /// Item definitions in the currently-compiled crate would have the CrateNum
25 /// LOCAL_CRATE in their DefId.
26 const LOCAL_CRATE = 0,
28 /// Virtual crate for builtin macros
29 // FIXME(jseyfried): this is also used for custom derives until proc-macro crates get
31 const BUILTIN_MACROS_CRATE = u32::MAX,
33 /// A CrateNum value that indicates that something is wrong.
34 const INVALID_CRATE = u32::MAX - 1,
38 pub fn new(x: usize) -> CrateNum {
39 assert!(x < (u32::MAX as usize));
43 pub fn from_u32(x: u32) -> CrateNum {
47 pub fn as_usize(&self) -> usize {
51 pub fn as_u32(&self) -> u32 {
55 pub fn as_def_id(&self) -> DefId { DefId { krate: *self, index: CRATE_DEF_INDEX } }
58 impl fmt::Display for CrateNum {
59 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
60 fmt::Display::fmt(&self.0, f)
64 impl serialize::UseSpecializedEncodable for CrateNum {
65 fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
70 impl serialize::UseSpecializedDecodable for CrateNum {
71 fn default_decode<D: Decoder>(d: &mut D) -> Result<CrateNum, D::Error> {
72 d.read_u32().map(CrateNum)
76 /// A DefIndex is an index into the hir-map for a crate, identifying a
77 /// particular definition. It should really be considered an interned
78 /// shorthand for a particular DefPath.
80 /// At the moment we are allocating the numerical values of DefIndexes into two
81 /// ranges: the "low" range (starting at zero) and the "high" range (starting at
82 /// DEF_INDEX_HI_START). This allows us to allocate the DefIndexes of all
83 /// item-likes (Items, TraitItems, and ImplItems) into one of these ranges and
84 /// consequently use a simple array for lookup tables keyed by DefIndex and
85 /// known to be densely populated. This is especially important for the HIR map.
87 /// Since the DefIndex is mostly treated as an opaque ID, you probably
88 /// don't have to care about these ranges.
89 #[derive(Clone, Eq, Ord, PartialOrd, PartialEq, RustcEncodable,
90 RustcDecodable, Hash, Copy)]
91 pub struct DefIndex(u32);
93 impl Idx for DefIndex {
94 fn new(value: usize) -> Self {
95 assert!(value < (u32::MAX) as usize);
96 DefIndex(value as u32)
99 fn index(self) -> usize {
104 impl fmt::Debug for DefIndex {
105 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
108 self.address_space().index(),
109 self.as_array_index())
115 pub fn new(x: usize) -> DefIndex {
116 assert!(x < (u32::MAX as usize));
121 pub fn from_u32(x: u32) -> DefIndex {
126 pub fn as_usize(&self) -> usize {
131 pub fn as_u32(&self) -> u32 {
136 pub fn address_space(&self) -> DefIndexAddressSpace {
137 if self.0 < DEF_INDEX_HI_START.0 {
138 DefIndexAddressSpace::Low
140 DefIndexAddressSpace::High
144 /// Converts this DefIndex into a zero-based array index.
145 /// This index is the offset within the given "range" of the DefIndex,
146 /// that is, if the DefIndex is part of the "high" range, the resulting
147 /// index will be (DefIndex - DEF_INDEX_HI_START).
149 pub fn as_array_index(&self) -> usize {
150 (self.0 & !DEF_INDEX_HI_START.0) as usize
153 pub fn from_array_index(i: usize, address_space: DefIndexAddressSpace) -> DefIndex {
154 DefIndex::new(address_space.start() + i)
158 /// The start of the "high" range of DefIndexes.
159 const DEF_INDEX_HI_START: DefIndex = DefIndex(1 << 31);
161 /// The crate root is always assigned index 0 by the AST Map code,
162 /// thanks to `NodeCollector::new`.
163 pub const CRATE_DEF_INDEX: DefIndex = DefIndex(0);
165 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
166 pub enum DefIndexAddressSpace {
171 impl DefIndexAddressSpace {
173 pub fn index(&self) -> usize {
178 pub fn start(&self) -> usize {
179 self.index() * DEF_INDEX_HI_START.as_usize()
183 /// A DefId identifies a particular *definition*, by combining a crate
184 /// index and a def index.
185 #[derive(Clone, Eq, Ord, PartialOrd, PartialEq, RustcEncodable, RustcDecodable, Hash, Copy)]
191 impl fmt::Debug for DefId {
192 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
193 write!(f, "DefId {{ krate: {:?}, index: {:?}",
194 self.krate, self.index)?;
196 ty::tls::with_opt(|opt_tcx| {
197 if let Some(tcx) = opt_tcx {
198 write!(f, " => {}", tcx.def_path_debug_str(*self))?;
209 /// Make a local `DefId` with the given index.
210 pub fn local(index: DefIndex) -> DefId {
211 DefId { krate: LOCAL_CRATE, index: index }
214 pub fn is_local(&self) -> bool {
215 self.krate == LOCAL_CRATE