1 // Copyright 2012-2016 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.
15 use rustc::hir::def::{self, CtorKind};
16 use rustc::hir::def_id::{DefIndex, DefId};
17 use rustc::middle::cstore::{DepKind, LinkagePreference, NativeLibrary};
18 use rustc::middle::lang_items;
20 use rustc::ty::{self, Ty};
21 use rustc_back::PanicStrategy;
23 use rustc_serialize as serialize;
24 use syntax::{ast, attr};
25 use syntax::symbol::Symbol;
26 use syntax_pos::{self, Span};
28 use std::marker::PhantomData;
30 pub fn rustc_version() -> String {
32 option_env!("CFG_VERSION").unwrap_or("unknown version"))
35 /// Metadata encoding version.
36 /// NB: increment this if you change the format of metadata such that
37 /// the rustc version can't be found to compare with `rustc_version()`.
38 pub const METADATA_VERSION: u8 = 4;
40 /// Metadata header which includes `METADATA_VERSION`.
41 /// To get older versions of rustc to ignore this metadata,
42 /// there are 4 zero bytes at the start, which are treated
43 /// as a length of 0 by old compilers.
45 /// This header is followed by the position of the `CrateRoot`,
46 /// which is encoded as a 32-bit big-endian unsigned integer,
47 /// and further followed by the rustc version string.
48 pub const METADATA_HEADER: &'static [u8; 12] =
49 &[0, 0, 0, 0, b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
51 /// The shorthand encoding uses an enum's variant index `usize`
52 /// and is offset by this value so it never matches a real variant.
53 /// This offset is also chosen so that the first byte is never < 0x80.
54 pub const SHORTHAND_OFFSET: usize = 0x80;
56 /// A value of type T referred to by its absolute position
57 /// in the metadata, and which can be decoded lazily.
59 /// Metadata is effective a tree, encoded in post-order,
60 /// and with the root's position written next to the header.
61 /// That means every single `Lazy` points to some previous
62 /// location in the metadata and is part of a larger node.
64 /// The first `Lazy` in a node is encoded as the backwards
65 /// distance from the position where the containing node
66 /// starts and where the `Lazy` points to, while the rest
67 /// use the forward distance from the previous `Lazy`.
68 /// Distances start at 1, as 0-byte nodes are invalid.
69 /// Also invalid are nodes being referred in a different
70 /// order than they were encoded in.
74 _marker: PhantomData<T>,
78 pub fn with_position(position: usize) -> Lazy<T> {
85 /// Returns the minimum encoded size of a value of type `T`.
86 // FIXME(eddyb) Give better estimates for certain types.
87 pub fn min_size() -> usize {
92 impl<T> Copy for Lazy<T> {}
93 impl<T> Clone for Lazy<T> {
94 fn clone(&self) -> Self {
99 impl<T> serialize::UseSpecializedEncodable for Lazy<T> {}
100 impl<T> serialize::UseSpecializedDecodable for Lazy<T> {}
102 /// A sequence of type T referred to by its absolute position
103 /// in the metadata and length, and which can be decoded lazily.
104 /// The sequence is a single node for the purposes of `Lazy`.
106 /// Unlike `Lazy<Vec<T>>`, the length is encoded next to the
107 /// position, not at the position, which means that the length
108 /// doesn't need to be known before encoding all the elements.
110 /// If the length is 0, no position is encoded, but otherwise,
111 /// the encoding is that of `Lazy`, with the distinction that
112 /// the minimal distance the length of the sequence, i.e.
113 /// it's assumed there's no 0-byte element in the sequence.
115 pub struct LazySeq<T> {
118 _marker: PhantomData<T>,
122 pub fn empty() -> LazySeq<T> {
123 LazySeq::with_position_and_length(0, 0)
126 pub fn with_position_and_length(position: usize, len: usize) -> LazySeq<T> {
130 _marker: PhantomData,
134 /// Returns the minimum encoded size of `length` values of type `T`.
135 pub fn min_size(length: usize) -> usize {
140 impl<T> Copy for LazySeq<T> {}
141 impl<T> Clone for LazySeq<T> {
142 fn clone(&self) -> Self {
147 impl<T> serialize::UseSpecializedEncodable for LazySeq<T> {}
148 impl<T> serialize::UseSpecializedDecodable for LazySeq<T> {}
150 /// Encoding / decoding state for `Lazy` and `LazySeq`.
151 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
153 /// Outside of a metadata node.
156 /// Inside a metadata node, and before any `Lazy` or `LazySeq`.
157 /// The position is that of the node itself.
160 /// Inside a metadata node, with a previous `Lazy` or `LazySeq`.
161 /// The position is a conservative estimate of where that
162 /// previous `Lazy` / `LazySeq` would end (see their comments).
166 #[derive(RustcEncodable, RustcDecodable)]
167 pub struct CrateRoot {
170 pub hash: hir::svh::Svh,
171 pub disambiguator: Symbol,
172 pub panic_strategy: PanicStrategy,
173 pub plugin_registrar_fn: Option<DefIndex>,
174 pub macro_derive_registrar: Option<DefIndex>,
176 pub crate_deps: LazySeq<CrateDep>,
177 pub dylib_dependency_formats: LazySeq<Option<LinkagePreference>>,
178 pub lang_items: LazySeq<(DefIndex, usize)>,
179 pub lang_items_missing: LazySeq<lang_items::LangItem>,
180 pub native_libraries: LazySeq<NativeLibrary>,
181 pub codemap: LazySeq<syntax_pos::FileMap>,
182 pub def_path_table: Lazy<hir::map::definitions::DefPathTable>,
183 pub impls: LazySeq<TraitImpls>,
184 pub exported_symbols: LazySeq<DefIndex>,
185 pub index: LazySeq<index::Index>,
188 #[derive(RustcEncodable, RustcDecodable)]
189 pub struct CrateDep {
191 pub hash: hir::svh::Svh,
195 #[derive(RustcEncodable, RustcDecodable)]
196 pub struct TraitImpls {
197 pub trait_id: (u32, DefIndex),
198 pub impls: LazySeq<DefIndex>,
201 #[derive(RustcEncodable, RustcDecodable)]
202 pub struct Entry<'tcx> {
203 pub kind: EntryKind<'tcx>,
204 pub visibility: Lazy<ty::Visibility>,
205 pub span: Lazy<Span>,
206 pub attributes: LazySeq<ast::Attribute>,
207 pub children: LazySeq<DefIndex>,
208 pub stability: Option<Lazy<attr::Stability>>,
209 pub deprecation: Option<Lazy<attr::Deprecation>>,
211 pub ty: Option<Lazy<Ty<'tcx>>>,
212 pub inherent_impls: LazySeq<DefIndex>,
213 pub variances: LazySeq<ty::Variance>,
214 pub generics: Option<Lazy<ty::Generics<'tcx>>>,
215 pub predicates: Option<Lazy<ty::GenericPredicates<'tcx>>>,
217 pub ast: Option<Lazy<astencode::Ast<'tcx>>>,
218 pub mir: Option<Lazy<mir::Mir<'tcx>>>,
221 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
222 pub enum EntryKind<'tcx> {
232 Variant(Lazy<VariantData>),
233 Struct(Lazy<VariantData>),
234 Union(Lazy<VariantData>),
236 ForeignFn(Lazy<FnData>),
238 MacroDef(Lazy<MacroDef>),
239 Closure(Lazy<ClosureData<'tcx>>),
240 Trait(Lazy<TraitData<'tcx>>),
241 Impl(Lazy<ImplData<'tcx>>),
242 DefaultImpl(Lazy<ImplData<'tcx>>),
243 Method(Lazy<MethodData>),
244 AssociatedType(AssociatedContainer),
245 AssociatedConst(AssociatedContainer),
248 #[derive(RustcEncodable, RustcDecodable)]
250 pub reexports: LazySeq<def::Export>,
253 #[derive(RustcEncodable, RustcDecodable)]
254 pub struct MacroDef {
258 #[derive(RustcEncodable, RustcDecodable)]
260 pub constness: hir::Constness,
261 pub arg_names: LazySeq<ast::Name>,
264 #[derive(RustcEncodable, RustcDecodable)]
265 pub struct VariantData {
266 pub ctor_kind: CtorKind,
269 /// If this is a struct's only variant, this
270 /// is the index of the "struct ctor" item.
271 pub struct_ctor: Option<DefIndex>,
274 #[derive(RustcEncodable, RustcDecodable)]
275 pub struct TraitData<'tcx> {
276 pub unsafety: hir::Unsafety,
277 pub paren_sugar: bool,
278 pub has_default_impl: bool,
279 pub super_predicates: Lazy<ty::GenericPredicates<'tcx>>,
282 #[derive(RustcEncodable, RustcDecodable)]
283 pub struct ImplData<'tcx> {
284 pub polarity: hir::ImplPolarity,
285 pub parent_impl: Option<DefId>,
286 pub coerce_unsized_kind: Option<ty::adjustment::CustomCoerceUnsized>,
287 pub trait_ref: Option<Lazy<ty::TraitRef<'tcx>>>,
290 /// Describes whether the container of an associated item
291 /// is a trait or an impl and whether, in a trait, it has
292 /// a default, or an in impl, whether it's marked "default".
293 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
294 pub enum AssociatedContainer {
301 impl AssociatedContainer {
302 pub fn with_def_id(&self, def_id: DefId) -> ty::AssociatedItemContainer {
304 AssociatedContainer::TraitRequired |
305 AssociatedContainer::TraitWithDefault => ty::TraitContainer(def_id),
307 AssociatedContainer::ImplDefault |
308 AssociatedContainer::ImplFinal => ty::ImplContainer(def_id),
312 pub fn defaultness(&self) -> hir::Defaultness {
314 AssociatedContainer::TraitRequired => hir::Defaultness::Default {
318 AssociatedContainer::TraitWithDefault |
319 AssociatedContainer::ImplDefault => hir::Defaultness::Default {
323 AssociatedContainer::ImplFinal => hir::Defaultness::Final,
328 #[derive(RustcEncodable, RustcDecodable)]
329 pub struct MethodData {
331 pub container: AssociatedContainer,
335 #[derive(RustcEncodable, RustcDecodable)]
336 pub struct ClosureData<'tcx> {
337 pub kind: ty::ClosureKind,
338 pub ty: Lazy<ty::ClosureTy<'tcx>>,