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, CrateNum};
17 use rustc::ich::StableHashingContext;
18 use rustc::middle::cstore::{DepKind, LinkagePreference, NativeLibrary};
19 use rustc::middle::lang_items;
21 use rustc::ty::{self, Ty, ReprOptions};
22 use rustc_back::PanicStrategy;
24 use rustc_serialize as serialize;
25 use syntax::{ast, attr};
26 use syntax::symbol::Symbol;
27 use syntax_pos::{self, Span};
29 use std::marker::PhantomData;
32 use rustc_data_structures::stable_hasher::{StableHasher, HashStable,
35 pub fn rustc_version() -> String {
37 option_env!("CFG_VERSION").unwrap_or("unknown version"))
40 /// Metadata encoding version.
41 /// NB: increment this if you change the format of metadata such that
42 /// the rustc version can't be found to compare with `rustc_version()`.
43 pub const METADATA_VERSION: u8 = 4;
45 /// Metadata header which includes `METADATA_VERSION`.
46 /// To get older versions of rustc to ignore this metadata,
47 /// there are 4 zero bytes at the start, which are treated
48 /// as a length of 0 by old compilers.
50 /// This header is followed by the position of the `CrateRoot`,
51 /// which is encoded as a 32-bit big-endian unsigned integer,
52 /// and further followed by the rustc version string.
53 pub const METADATA_HEADER: &'static [u8; 12] =
54 &[0, 0, 0, 0, b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
56 /// The shorthand encoding uses an enum's variant index `usize`
57 /// and is offset by this value so it never matches a real variant.
58 /// This offset is also chosen so that the first byte is never < 0x80.
59 pub const SHORTHAND_OFFSET: usize = 0x80;
61 /// A value of type T referred to by its absolute position
62 /// in the metadata, and which can be decoded lazily.
64 /// Metadata is effective a tree, encoded in post-order,
65 /// and with the root's position written next to the header.
66 /// That means every single `Lazy` points to some previous
67 /// location in the metadata and is part of a larger node.
69 /// The first `Lazy` in a node is encoded as the backwards
70 /// distance from the position where the containing node
71 /// starts and where the `Lazy` points to, while the rest
72 /// use the forward distance from the previous `Lazy`.
73 /// Distances start at 1, as 0-byte nodes are invalid.
74 /// Also invalid are nodes being referred in a different
75 /// order than they were encoded in.
79 _marker: PhantomData<T>,
83 pub fn with_position(position: usize) -> Lazy<T> {
90 /// Returns the minimum encoded size of a value of type `T`.
91 // FIXME(eddyb) Give better estimates for certain types.
92 pub fn min_size() -> usize {
97 impl<T> Copy for Lazy<T> {}
98 impl<T> Clone for Lazy<T> {
99 fn clone(&self) -> Self {
104 impl<T> serialize::UseSpecializedEncodable for Lazy<T> {}
105 impl<T> serialize::UseSpecializedDecodable for Lazy<T> {}
107 impl<CTX, T> HashStable<CTX> for Lazy<T> {
108 fn hash_stable<W: StableHasherResult>(&self,
110 _: &mut StableHasher<W>) {
111 // There's nothing to do. Whatever got encoded within this Lazy<>
112 // wrapper has already been hashed.
116 /// A sequence of type T referred to by its absolute position
117 /// in the metadata and length, and which can be decoded lazily.
118 /// The sequence is a single node for the purposes of `Lazy`.
120 /// Unlike `Lazy<Vec<T>>`, the length is encoded next to the
121 /// position, not at the position, which means that the length
122 /// doesn't need to be known before encoding all the elements.
124 /// If the length is 0, no position is encoded, but otherwise,
125 /// the encoding is that of `Lazy`, with the distinction that
126 /// the minimal distance the length of the sequence, i.e.
127 /// it's assumed there's no 0-byte element in the sequence.
129 pub struct LazySeq<T> {
132 _marker: PhantomData<T>,
136 pub fn empty() -> LazySeq<T> {
137 LazySeq::with_position_and_length(0, 0)
140 pub fn with_position_and_length(position: usize, len: usize) -> LazySeq<T> {
144 _marker: PhantomData,
148 /// Returns the minimum encoded size of `length` values of type `T`.
149 pub fn min_size(length: usize) -> usize {
154 impl<T> Copy for LazySeq<T> {}
155 impl<T> Clone for LazySeq<T> {
156 fn clone(&self) -> Self {
161 impl<T> serialize::UseSpecializedEncodable for LazySeq<T> {}
162 impl<T> serialize::UseSpecializedDecodable for LazySeq<T> {}
164 impl<CTX, T> HashStable<CTX> for LazySeq<T> {
165 fn hash_stable<W: StableHasherResult>(&self,
167 _: &mut StableHasher<W>) {
168 // There's nothing to do. Whatever got encoded within this Lazy<>
169 // wrapper has already been hashed.
173 /// Encoding / decoding state for `Lazy` and `LazySeq`.
174 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
176 /// Outside of a metadata node.
179 /// Inside a metadata node, and before any `Lazy` or `LazySeq`.
180 /// The position is that of the node itself.
183 /// Inside a metadata node, with a previous `Lazy` or `LazySeq`.
184 /// The position is a conservative estimate of where that
185 /// previous `Lazy` / `LazySeq` would end (see their comments).
189 #[derive(RustcEncodable, RustcDecodable)]
190 pub struct CrateRoot {
193 pub hash: hir::svh::Svh,
194 pub disambiguator: Symbol,
195 pub panic_strategy: PanicStrategy,
196 pub has_global_allocator: bool,
197 pub has_default_lib_allocator: bool,
198 pub plugin_registrar_fn: Option<DefIndex>,
199 pub macro_derive_registrar: Option<DefIndex>,
201 pub crate_deps: LazySeq<CrateDep>,
202 pub dylib_dependency_formats: LazySeq<Option<LinkagePreference>>,
203 pub lang_items: LazySeq<(DefIndex, usize)>,
204 pub lang_items_missing: LazySeq<lang_items::LangItem>,
205 pub native_libraries: LazySeq<NativeLibrary>,
206 pub codemap: LazySeq<syntax_pos::FileMap>,
207 pub def_path_table: Lazy<hir::map::definitions::DefPathTable>,
208 pub impls: LazySeq<TraitImpls>,
209 pub exported_symbols: LazySeq<DefIndex>,
210 pub index: LazySeq<index::Index>,
213 #[derive(RustcEncodable, RustcDecodable)]
214 pub struct CrateDep {
216 pub hash: hir::svh::Svh,
220 impl_stable_hash_for!(struct CrateDep {
226 #[derive(RustcEncodable, RustcDecodable)]
227 pub struct TraitImpls {
228 pub trait_id: (u32, DefIndex),
229 pub impls: LazySeq<DefIndex>,
232 impl<'gcx> HashStable<StableHashingContext<'gcx>> for TraitImpls {
233 fn hash_stable<W: StableHasherResult>(&self,
234 hcx: &mut StableHashingContext<'gcx>,
235 hasher: &mut StableHasher<W>) {
237 trait_id: (krate, def_index),
242 krate: CrateNum::from_u32(krate),
244 }.hash_stable(hcx, hasher);
245 impls.hash_stable(hcx, hasher);
249 #[derive(RustcEncodable, RustcDecodable)]
250 pub struct Entry<'tcx> {
251 pub kind: EntryKind<'tcx>,
252 pub visibility: Lazy<ty::Visibility>,
253 pub span: Lazy<Span>,
254 pub attributes: LazySeq<ast::Attribute>,
255 pub children: LazySeq<DefIndex>,
256 pub stability: Option<Lazy<attr::Stability>>,
257 pub deprecation: Option<Lazy<attr::Deprecation>>,
259 pub ty: Option<Lazy<Ty<'tcx>>>,
260 pub inherent_impls: LazySeq<DefIndex>,
261 pub variances: LazySeq<ty::Variance>,
262 pub generics: Option<Lazy<ty::Generics>>,
263 pub predicates: Option<Lazy<ty::GenericPredicates<'tcx>>>,
265 pub ast: Option<Lazy<astencode::Ast<'tcx>>>,
266 pub mir: Option<Lazy<mir::Mir<'tcx>>>,
269 impl_stable_hash_for!(struct Entry<'tcx> {
286 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
287 pub enum EntryKind<'tcx> {
298 Variant(Lazy<VariantData<'tcx>>),
299 Struct(Lazy<VariantData<'tcx>>, ReprOptions),
300 Union(Lazy<VariantData<'tcx>>, ReprOptions),
301 Fn(Lazy<FnData<'tcx>>),
302 ForeignFn(Lazy<FnData<'tcx>>),
304 MacroDef(Lazy<MacroDef>),
305 Closure(Lazy<ClosureData<'tcx>>),
306 Generator(Lazy<GeneratorData<'tcx>>),
307 Trait(Lazy<TraitData<'tcx>>),
308 Impl(Lazy<ImplData<'tcx>>),
309 DefaultImpl(Lazy<ImplData<'tcx>>),
310 Method(Lazy<MethodData<'tcx>>),
311 AssociatedType(AssociatedContainer),
312 AssociatedConst(AssociatedContainer, u8),
315 impl<'gcx> HashStable<StableHashingContext<'gcx>> for EntryKind<'gcx> {
316 fn hash_stable<W: StableHasherResult>(&self,
317 hcx: &mut StableHashingContext<'gcx>,
318 hasher: &mut StableHasher<W>) {
319 mem::discriminant(self).hash_stable(hcx, hasher);
321 EntryKind::ImmStatic |
322 EntryKind::MutStatic |
323 EntryKind::ForeignImmStatic |
324 EntryKind::ForeignMutStatic |
325 EntryKind::ForeignMod |
326 EntryKind::GlobalAsm |
329 // Nothing else to hash here.
331 EntryKind::Const(qualif) => {
332 qualif.hash_stable(hcx, hasher);
334 EntryKind::Enum(ref repr_options) => {
335 repr_options.hash_stable(hcx, hasher);
337 EntryKind::Variant(ref variant_data) => {
338 variant_data.hash_stable(hcx, hasher);
340 EntryKind::Struct(ref variant_data, ref repr_options) |
341 EntryKind::Union(ref variant_data, ref repr_options) => {
342 variant_data.hash_stable(hcx, hasher);
343 repr_options.hash_stable(hcx, hasher);
345 EntryKind::Fn(ref fn_data) |
346 EntryKind::ForeignFn(ref fn_data) => {
347 fn_data.hash_stable(hcx, hasher);
349 EntryKind::Mod(ref mod_data) => {
350 mod_data.hash_stable(hcx, hasher);
352 EntryKind::MacroDef(ref macro_def) => {
353 macro_def.hash_stable(hcx, hasher);
355 EntryKind::Generator(data) => {
356 data.hash_stable(hcx, hasher);
358 EntryKind::Closure(closure_data) => {
359 closure_data.hash_stable(hcx, hasher);
361 EntryKind::Trait(ref trait_data) => {
362 trait_data.hash_stable(hcx, hasher);
364 EntryKind::DefaultImpl(ref impl_data) |
365 EntryKind::Impl(ref impl_data) => {
366 impl_data.hash_stable(hcx, hasher);
368 EntryKind::Method(ref method_data) => {
369 method_data.hash_stable(hcx, hasher);
371 EntryKind::AssociatedType(associated_container) => {
372 associated_container.hash_stable(hcx, hasher);
374 EntryKind::AssociatedConst(associated_container, qualif) => {
375 associated_container.hash_stable(hcx, hasher);
376 qualif.hash_stable(hcx, hasher);
382 #[derive(RustcEncodable, RustcDecodable)]
384 pub reexports: LazySeq<def::Export>,
387 impl_stable_hash_for!(struct ModData { reexports });
389 #[derive(RustcEncodable, RustcDecodable)]
390 pub struct MacroDef {
395 impl_stable_hash_for!(struct MacroDef { body, legacy });
397 #[derive(RustcEncodable, RustcDecodable)]
398 pub struct FnData<'tcx> {
399 pub constness: hir::Constness,
400 pub arg_names: LazySeq<ast::Name>,
401 pub sig: Lazy<ty::PolyFnSig<'tcx>>,
404 impl_stable_hash_for!(struct FnData<'tcx> { constness, arg_names, sig });
406 #[derive(RustcEncodable, RustcDecodable)]
407 pub struct VariantData<'tcx> {
408 pub ctor_kind: CtorKind,
409 pub discr: ty::VariantDiscr,
411 /// If this is a struct's only variant, this
412 /// is the index of the "struct ctor" item.
413 pub struct_ctor: Option<DefIndex>,
415 /// If this is a tuple struct or variant
416 /// ctor, this is its "function" signature.
417 pub ctor_sig: Option<Lazy<ty::PolyFnSig<'tcx>>>,
420 impl_stable_hash_for!(struct VariantData<'tcx> {
427 #[derive(RustcEncodable, RustcDecodable)]
428 pub struct TraitData<'tcx> {
429 pub unsafety: hir::Unsafety,
430 pub paren_sugar: bool,
431 pub has_default_impl: bool,
432 pub super_predicates: Lazy<ty::GenericPredicates<'tcx>>,
435 impl_stable_hash_for!(struct TraitData<'tcx> {
442 #[derive(RustcEncodable, RustcDecodable)]
443 pub struct ImplData<'tcx> {
444 pub polarity: hir::ImplPolarity,
445 pub defaultness: hir::Defaultness,
446 pub parent_impl: Option<DefId>,
448 /// This is `Some` only for impls of `CoerceUnsized`.
449 pub coerce_unsized_info: Option<ty::adjustment::CoerceUnsizedInfo>,
450 pub trait_ref: Option<Lazy<ty::TraitRef<'tcx>>>,
453 impl_stable_hash_for!(struct ImplData<'tcx> {
462 /// Describes whether the container of an associated item
463 /// is a trait or an impl and whether, in a trait, it has
464 /// a default, or an in impl, whether it's marked "default".
465 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
466 pub enum AssociatedContainer {
473 impl_stable_hash_for!(enum ::schema::AssociatedContainer {
480 impl AssociatedContainer {
481 pub fn with_def_id(&self, def_id: DefId) -> ty::AssociatedItemContainer {
483 AssociatedContainer::TraitRequired |
484 AssociatedContainer::TraitWithDefault => ty::TraitContainer(def_id),
486 AssociatedContainer::ImplDefault |
487 AssociatedContainer::ImplFinal => ty::ImplContainer(def_id),
491 pub fn defaultness(&self) -> hir::Defaultness {
493 AssociatedContainer::TraitRequired => hir::Defaultness::Default {
497 AssociatedContainer::TraitWithDefault |
498 AssociatedContainer::ImplDefault => hir::Defaultness::Default {
502 AssociatedContainer::ImplFinal => hir::Defaultness::Final,
507 #[derive(RustcEncodable, RustcDecodable)]
508 pub struct MethodData<'tcx> {
509 pub fn_data: FnData<'tcx>,
510 pub container: AssociatedContainer,
513 impl_stable_hash_for!(struct MethodData<'tcx> { fn_data, container, has_self });
515 #[derive(RustcEncodable, RustcDecodable)]
516 pub struct ClosureData<'tcx> {
517 pub kind: ty::ClosureKind,
518 pub sig: Lazy<ty::PolyFnSig<'tcx>>,
520 impl_stable_hash_for!(struct ClosureData<'tcx> { kind, sig });
522 #[derive(RustcEncodable, RustcDecodable)]
523 pub struct GeneratorData<'tcx> {
524 pub sig: ty::PolyGenSig<'tcx>,
525 pub layout: mir::GeneratorLayout<'tcx>,
527 impl_stable_hash_for!(struct GeneratorData<'tcx> { sig, layout });