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::ich::StableHashingContext;
18 use rustc::middle::const_val::ConstVal;
19 use rustc::middle::cstore::{DepKind, LinkagePreference, NativeLibrary};
20 use rustc::middle::lang_items;
22 use rustc::ty::{self, Ty, ReprOptions};
23 use rustc_back::PanicStrategy;
25 use rustc_serialize as serialize;
26 use syntax::{ast, attr};
27 use syntax::symbol::Symbol;
28 use syntax_pos::{self, Span};
30 use std::marker::PhantomData;
33 use rustc_data_structures::stable_hasher::{StableHasher, HashStable,
36 pub fn rustc_version() -> String {
38 option_env!("CFG_VERSION").unwrap_or("unknown version"))
41 /// Metadata encoding version.
42 /// NB: increment this if you change the format of metadata such that
43 /// the rustc version can't be found to compare with `rustc_version()`.
44 pub const METADATA_VERSION: u8 = 4;
46 /// Metadata header which includes `METADATA_VERSION`.
47 /// To get older versions of rustc to ignore this metadata,
48 /// there are 4 zero bytes at the start, which are treated
49 /// as a length of 0 by old compilers.
51 /// This header is followed by the position of the `CrateRoot`,
52 /// which is encoded as a 32-bit big-endian unsigned integer,
53 /// and further followed by the rustc version string.
54 pub const METADATA_HEADER: &'static [u8; 12] =
55 &[0, 0, 0, 0, b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
57 /// The shorthand encoding uses an enum's variant index `usize`
58 /// and is offset by this value so it never matches a real variant.
59 /// This offset is also chosen so that the first byte is never < 0x80.
60 pub const SHORTHAND_OFFSET: usize = 0x80;
62 /// A value of type T referred to by its absolute position
63 /// in the metadata, and which can be decoded lazily.
65 /// Metadata is effective a tree, encoded in post-order,
66 /// and with the root's position written next to the header.
67 /// That means every single `Lazy` points to some previous
68 /// location in the metadata and is part of a larger node.
70 /// The first `Lazy` in a node is encoded as the backwards
71 /// distance from the position where the containing node
72 /// starts and where the `Lazy` points to, while the rest
73 /// use the forward distance from the previous `Lazy`.
74 /// Distances start at 1, as 0-byte nodes are invalid.
75 /// Also invalid are nodes being referred in a different
76 /// order than they were encoded in.
80 _marker: PhantomData<T>,
84 pub fn with_position(position: usize) -> Lazy<T> {
91 /// Returns the minimum encoded size of a value of type `T`.
92 // FIXME(eddyb) Give better estimates for certain types.
93 pub fn min_size() -> usize {
98 impl<T> Copy for Lazy<T> {}
99 impl<T> Clone for Lazy<T> {
100 fn clone(&self) -> Self {
105 impl<T> serialize::UseSpecializedEncodable for Lazy<T> {}
106 impl<T> serialize::UseSpecializedDecodable for Lazy<T> {}
108 impl<CTX, T> HashStable<CTX> for Lazy<T> {
109 fn hash_stable<W: StableHasherResult>(&self,
111 _: &mut StableHasher<W>) {
112 // There's nothing to do. Whatever got encoded within this Lazy<>
113 // wrapper has already been hashed.
117 /// A sequence of type T referred to by its absolute position
118 /// in the metadata and length, and which can be decoded lazily.
119 /// The sequence is a single node for the purposes of `Lazy`.
121 /// Unlike `Lazy<Vec<T>>`, the length is encoded next to the
122 /// position, not at the position, which means that the length
123 /// doesn't need to be known before encoding all the elements.
125 /// If the length is 0, no position is encoded, but otherwise,
126 /// the encoding is that of `Lazy`, with the distinction that
127 /// the minimal distance the length of the sequence, i.e.
128 /// it's assumed there's no 0-byte element in the sequence.
130 pub struct LazySeq<T> {
133 _marker: PhantomData<T>,
137 pub fn empty() -> LazySeq<T> {
138 LazySeq::with_position_and_length(0, 0)
141 pub fn with_position_and_length(position: usize, len: usize) -> LazySeq<T> {
145 _marker: PhantomData,
149 /// Returns the minimum encoded size of `length` values of type `T`.
150 pub fn min_size(length: usize) -> usize {
155 impl<T> Copy for LazySeq<T> {}
156 impl<T> Clone for LazySeq<T> {
157 fn clone(&self) -> Self {
162 impl<T> serialize::UseSpecializedEncodable for LazySeq<T> {}
163 impl<T> serialize::UseSpecializedDecodable for LazySeq<T> {}
165 impl<CTX, T> HashStable<CTX> for LazySeq<T> {
166 fn hash_stable<W: StableHasherResult>(&self,
168 _: &mut StableHasher<W>) {
169 // There's nothing to do. Whatever got encoded within this Lazy<>
170 // wrapper has already been hashed.
174 /// Encoding / decoding state for `Lazy` and `LazySeq`.
175 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
177 /// Outside of a metadata node.
180 /// Inside a metadata node, and before any `Lazy` or `LazySeq`.
181 /// The position is that of the node itself.
184 /// Inside a metadata node, with a previous `Lazy` or `LazySeq`.
185 /// The position is a conservative estimate of where that
186 /// previous `Lazy` / `LazySeq` would end (see their comments).
190 #[derive(RustcEncodable, RustcDecodable)]
191 pub struct CrateRoot {
194 pub hash: hir::svh::Svh,
195 pub disambiguator: Symbol,
196 pub panic_strategy: PanicStrategy,
197 pub plugin_registrar_fn: Option<DefIndex>,
198 pub macro_derive_registrar: Option<DefIndex>,
200 pub crate_deps: LazySeq<CrateDep>,
201 pub dylib_dependency_formats: LazySeq<Option<LinkagePreference>>,
202 pub lang_items: LazySeq<(DefIndex, usize)>,
203 pub lang_items_missing: LazySeq<lang_items::LangItem>,
204 pub native_libraries: LazySeq<NativeLibrary>,
205 pub codemap: LazySeq<syntax_pos::FileMap>,
206 pub def_path_table: Lazy<hir::map::definitions::DefPathTable>,
207 pub impls: LazySeq<TraitImpls>,
208 pub exported_symbols: LazySeq<DefIndex>,
209 pub index: LazySeq<index::Index>,
212 #[derive(RustcEncodable, RustcDecodable)]
213 pub struct CrateDep {
215 pub hash: hir::svh::Svh,
219 #[derive(RustcEncodable, RustcDecodable)]
220 pub struct TraitImpls {
221 pub trait_id: (u32, DefIndex),
222 pub impls: LazySeq<DefIndex>,
225 #[derive(RustcEncodable, RustcDecodable)]
226 pub struct Entry<'tcx> {
227 pub kind: EntryKind<'tcx>,
228 pub visibility: Lazy<ty::Visibility>,
229 pub span: Lazy<Span>,
230 pub attributes: LazySeq<ast::Attribute>,
231 pub children: LazySeq<DefIndex>,
232 pub stability: Option<Lazy<attr::Stability>>,
233 pub deprecation: Option<Lazy<attr::Deprecation>>,
235 pub ty: Option<Lazy<Ty<'tcx>>>,
236 pub inherent_impls: LazySeq<DefIndex>,
237 pub variances: LazySeq<ty::Variance>,
238 pub generics: Option<Lazy<ty::Generics>>,
239 pub predicates: Option<Lazy<ty::GenericPredicates<'tcx>>>,
241 pub ast: Option<Lazy<astencode::Ast<'tcx>>>,
242 pub mir: Option<Lazy<mir::Mir<'tcx>>>,
245 impl_stable_hash_for!(struct Entry<'tcx> {
262 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
263 pub enum EntryKind<'tcx> {
273 Variant(Lazy<VariantData<'tcx>>),
274 Struct(Lazy<VariantData<'tcx>>, ReprOptions),
275 Union(Lazy<VariantData<'tcx>>, ReprOptions),
277 ForeignFn(Lazy<FnData>),
279 MacroDef(Lazy<MacroDef>),
280 Closure(Lazy<ClosureData<'tcx>>),
281 Trait(Lazy<TraitData<'tcx>>),
282 Impl(Lazy<ImplData<'tcx>>),
283 DefaultImpl(Lazy<ImplData<'tcx>>),
284 Method(Lazy<MethodData>),
285 AssociatedType(AssociatedContainer),
286 AssociatedConst(AssociatedContainer, u8),
289 impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for EntryKind<'tcx> {
290 fn hash_stable<W: StableHasherResult>(&self,
291 hcx: &mut StableHashingContext<'a, 'tcx>,
292 hasher: &mut StableHasher<W>) {
293 mem::discriminant(self).hash_stable(hcx, hasher);
295 EntryKind::ImmStatic |
296 EntryKind::MutStatic |
297 EntryKind::ForeignImmStatic |
298 EntryKind::ForeignMutStatic |
299 EntryKind::ForeignMod |
302 // Nothing else to hash here.
304 EntryKind::Const(qualif) => {
305 qualif.hash_stable(hcx, hasher);
307 EntryKind::Enum(ref repr_options) => {
308 repr_options.hash_stable(hcx, hasher);
310 EntryKind::Variant(ref variant_data) => {
311 variant_data.hash_stable(hcx, hasher);
313 EntryKind::Struct(ref variant_data, ref repr_options) |
314 EntryKind::Union(ref variant_data, ref repr_options) => {
315 variant_data.hash_stable(hcx, hasher);
316 repr_options.hash_stable(hcx, hasher);
318 EntryKind::Fn(ref fn_data) |
319 EntryKind::ForeignFn(ref fn_data) => {
320 fn_data.hash_stable(hcx, hasher);
322 EntryKind::Mod(ref mod_data) => {
323 mod_data.hash_stable(hcx, hasher);
325 EntryKind::MacroDef(ref macro_def) => {
326 macro_def.hash_stable(hcx, hasher);
328 EntryKind::Closure(closure_data) => {
329 closure_data.hash_stable(hcx, hasher);
331 EntryKind::Trait(ref trait_data) => {
332 trait_data.hash_stable(hcx, hasher);
334 EntryKind::DefaultImpl(ref impl_data) |
335 EntryKind::Impl(ref impl_data) => {
336 impl_data.hash_stable(hcx, hasher);
338 EntryKind::Method(ref method_data) => {
339 method_data.hash_stable(hcx, hasher);
341 EntryKind::AssociatedType(associated_container) => {
342 associated_container.hash_stable(hcx, hasher);
344 EntryKind::AssociatedConst(associated_container, qualif) => {
345 associated_container.hash_stable(hcx, hasher);
346 qualif.hash_stable(hcx, hasher);
352 #[derive(RustcEncodable, RustcDecodable)]
354 pub reexports: LazySeq<def::Export>,
357 impl_stable_hash_for!(struct ModData { reexports });
359 #[derive(RustcEncodable, RustcDecodable)]
360 pub struct MacroDef {
364 impl_stable_hash_for!(struct MacroDef { body });
366 #[derive(RustcEncodable, RustcDecodable)]
368 pub constness: hir::Constness,
369 pub arg_names: LazySeq<ast::Name>,
372 impl_stable_hash_for!(struct FnData { constness, arg_names });
374 #[derive(RustcEncodable, RustcDecodable)]
375 pub struct VariantData<'tcx> {
376 pub ctor_kind: CtorKind,
377 pub discr: ty::VariantDiscr,
378 pub evaluated_discr: Option<ConstVal<'tcx>>,
380 /// If this is a struct's only variant, this
381 /// is the index of the "struct ctor" item.
382 pub struct_ctor: Option<DefIndex>,
385 impl_stable_hash_for!(struct VariantData<'tcx> {
392 #[derive(RustcEncodable, RustcDecodable)]
393 pub struct TraitData<'tcx> {
394 pub unsafety: hir::Unsafety,
395 pub paren_sugar: bool,
396 pub has_default_impl: bool,
397 pub super_predicates: Lazy<ty::GenericPredicates<'tcx>>,
400 impl_stable_hash_for!(struct TraitData<'tcx> {
407 #[derive(RustcEncodable, RustcDecodable)]
408 pub struct ImplData<'tcx> {
409 pub polarity: hir::ImplPolarity,
410 pub parent_impl: Option<DefId>,
412 /// This is `Some` only for impls of `CoerceUnsized`.
413 pub coerce_unsized_info: Option<ty::adjustment::CoerceUnsizedInfo>,
414 pub trait_ref: Option<Lazy<ty::TraitRef<'tcx>>>,
417 impl_stable_hash_for!(struct ImplData<'tcx> {
425 /// Describes whether the container of an associated item
426 /// is a trait or an impl and whether, in a trait, it has
427 /// a default, or an in impl, whether it's marked "default".
428 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
429 pub enum AssociatedContainer {
436 impl_stable_hash_for!(enum ::schema::AssociatedContainer {
443 impl AssociatedContainer {
444 pub fn with_def_id(&self, def_id: DefId) -> ty::AssociatedItemContainer {
446 AssociatedContainer::TraitRequired |
447 AssociatedContainer::TraitWithDefault => ty::TraitContainer(def_id),
449 AssociatedContainer::ImplDefault |
450 AssociatedContainer::ImplFinal => ty::ImplContainer(def_id),
454 pub fn defaultness(&self) -> hir::Defaultness {
456 AssociatedContainer::TraitRequired => hir::Defaultness::Default {
460 AssociatedContainer::TraitWithDefault |
461 AssociatedContainer::ImplDefault => hir::Defaultness::Default {
465 AssociatedContainer::ImplFinal => hir::Defaultness::Final,
470 #[derive(RustcEncodable, RustcDecodable)]
471 pub struct MethodData {
473 pub container: AssociatedContainer,
476 impl_stable_hash_for!(struct MethodData { fn_data, container, has_self });
478 #[derive(RustcEncodable, RustcDecodable)]
479 pub struct ClosureData<'tcx> {
480 pub kind: ty::ClosureKind,
481 pub ty: Lazy<ty::PolyFnSig<'tcx>>,
483 impl_stable_hash_for!(struct ClosureData<'tcx> { kind, ty });