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 use rustc::dep_graph::{DepGraph, DepNode};
37 pub fn rustc_version() -> String {
39 option_env!("CFG_VERSION").unwrap_or("unknown version"))
42 /// Metadata encoding version.
43 /// NB: increment this if you change the format of metadata such that
44 /// the rustc version can't be found to compare with `rustc_version()`.
45 pub const METADATA_VERSION: u8 = 4;
47 /// Metadata header which includes `METADATA_VERSION`.
48 /// To get older versions of rustc to ignore this metadata,
49 /// there are 4 zero bytes at the start, which are treated
50 /// as a length of 0 by old compilers.
52 /// This header is followed by the position of the `CrateRoot`,
53 /// which is encoded as a 32-bit big-endian unsigned integer,
54 /// and further followed by the rustc version string.
55 pub const METADATA_HEADER: &'static [u8; 12] =
56 &[0, 0, 0, 0, b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
58 /// The shorthand encoding uses an enum's variant index `usize`
59 /// and is offset by this value so it never matches a real variant.
60 /// This offset is also chosen so that the first byte is never < 0x80.
61 pub const SHORTHAND_OFFSET: usize = 0x80;
63 /// A value of type T referred to by its absolute position
64 /// in the metadata, and which can be decoded lazily.
66 /// Metadata is effective a tree, encoded in post-order,
67 /// and with the root's position written next to the header.
68 /// That means every single `Lazy` points to some previous
69 /// location in the metadata and is part of a larger node.
71 /// The first `Lazy` in a node is encoded as the backwards
72 /// distance from the position where the containing node
73 /// starts and where the `Lazy` points to, while the rest
74 /// use the forward distance from the previous `Lazy`.
75 /// Distances start at 1, as 0-byte nodes are invalid.
76 /// Also invalid are nodes being referred in a different
77 /// order than they were encoded in.
81 _marker: PhantomData<T>,
85 pub fn with_position(position: usize) -> Lazy<T> {
92 /// Returns the minimum encoded size of a value of type `T`.
93 // FIXME(eddyb) Give better estimates for certain types.
94 pub fn min_size() -> usize {
99 impl<T> Copy for Lazy<T> {}
100 impl<T> Clone for Lazy<T> {
101 fn clone(&self) -> Self {
106 impl<T> serialize::UseSpecializedEncodable for Lazy<T> {}
107 impl<T> serialize::UseSpecializedDecodable for Lazy<T> {}
109 impl<CTX, T> HashStable<CTX> for Lazy<T> {
110 fn hash_stable<W: StableHasherResult>(&self,
112 _: &mut StableHasher<W>) {
113 // There's nothing to do. Whatever got encoded within this Lazy<>
114 // wrapper has already been hashed.
118 /// A sequence of type T referred to by its absolute position
119 /// in the metadata and length, and which can be decoded lazily.
120 /// The sequence is a single node for the purposes of `Lazy`.
122 /// Unlike `Lazy<Vec<T>>`, the length is encoded next to the
123 /// position, not at the position, which means that the length
124 /// doesn't need to be known before encoding all the elements.
126 /// If the length is 0, no position is encoded, but otherwise,
127 /// the encoding is that of `Lazy`, with the distinction that
128 /// the minimal distance the length of the sequence, i.e.
129 /// it's assumed there's no 0-byte element in the sequence.
131 pub struct LazySeq<T> {
134 _marker: PhantomData<T>,
138 pub fn empty() -> LazySeq<T> {
139 LazySeq::with_position_and_length(0, 0)
142 pub fn with_position_and_length(position: usize, len: usize) -> LazySeq<T> {
146 _marker: PhantomData,
150 /// Returns the minimum encoded size of `length` values of type `T`.
151 pub fn min_size(length: usize) -> usize {
156 impl<T> Copy for LazySeq<T> {}
157 impl<T> Clone for LazySeq<T> {
158 fn clone(&self) -> Self {
163 impl<T> serialize::UseSpecializedEncodable for LazySeq<T> {}
164 impl<T> serialize::UseSpecializedDecodable for LazySeq<T> {}
166 impl<CTX, T> HashStable<CTX> for LazySeq<T> {
167 fn hash_stable<W: StableHasherResult>(&self,
169 _: &mut StableHasher<W>) {
170 // There's nothing to do. Whatever got encoded within this Lazy<>
171 // wrapper has already been hashed.
175 /// Encoding / decoding state for `Lazy` and `LazySeq`.
176 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
178 /// Outside of a metadata node.
181 /// Inside a metadata node, and before any `Lazy` or `LazySeq`.
182 /// The position is that of the node itself.
185 /// Inside a metadata node, with a previous `Lazy` or `LazySeq`.
186 /// The position is a conservative estimate of where that
187 /// previous `Lazy` / `LazySeq` would end (see their comments).
191 /// A `Tracked<T>` wraps a value so that one can only access it when specifying
192 /// the `DepNode` for that value. This makes it harder to forget registering
194 #[derive(RustcEncodable, RustcDecodable)]
195 pub struct Tracked<T> {
200 pub fn new(state: T) -> Tracked<T> {
206 pub fn get(&self, dep_graph: &DepGraph, dep_node: DepNode) -> &T {
207 dep_graph.read(dep_node);
211 pub fn get_untracked(&self) -> &T {
215 pub fn map<F, R>(&self, f: F) -> Tracked<R>
216 where F: FnOnce(&T) -> R
219 state: f(&self.state),
224 impl<'a, 'gcx, 'tcx, T> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for Tracked<T>
225 where T: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
227 fn hash_stable<W: StableHasherResult>(&self,
228 hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
229 hasher: &mut StableHasher<W>) {
234 state.hash_stable(hcx, hasher);
239 #[derive(RustcEncodable, RustcDecodable)]
240 pub struct CrateRoot {
243 pub hash: hir::svh::Svh,
244 pub disambiguator: Symbol,
245 pub panic_strategy: Tracked<PanicStrategy>,
246 pub has_global_allocator: Tracked<bool>,
247 pub has_default_lib_allocator: Tracked<bool>,
248 pub plugin_registrar_fn: Option<DefIndex>,
249 pub macro_derive_registrar: Option<DefIndex>,
251 pub crate_deps: Tracked<LazySeq<CrateDep>>,
252 pub dylib_dependency_formats: Tracked<LazySeq<Option<LinkagePreference>>>,
253 pub lang_items: Tracked<LazySeq<(DefIndex, usize)>>,
254 pub lang_items_missing: Tracked<LazySeq<lang_items::LangItem>>,
255 pub native_libraries: Tracked<LazySeq<NativeLibrary>>,
256 pub codemap: LazySeq<syntax_pos::FileMap>,
257 pub def_path_table: Lazy<hir::map::definitions::DefPathTable>,
258 pub impls: Tracked<LazySeq<TraitImpls>>,
259 pub exported_symbols: Tracked<LazySeq<DefIndex>>,
260 pub index: LazySeq<index::Index>,
263 #[derive(RustcEncodable, RustcDecodable)]
264 pub struct CrateDep {
266 pub hash: hir::svh::Svh,
270 impl_stable_hash_for!(struct CrateDep {
276 #[derive(RustcEncodable, RustcDecodable)]
277 pub struct TraitImpls {
278 pub trait_id: (u32, DefIndex),
279 pub impls: LazySeq<DefIndex>,
282 impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for TraitImpls {
283 fn hash_stable<W: StableHasherResult>(&self,
284 hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
285 hasher: &mut StableHasher<W>) {
287 trait_id: (krate, def_index),
292 krate: CrateNum::from_u32(krate),
294 }.hash_stable(hcx, hasher);
295 impls.hash_stable(hcx, hasher);
299 #[derive(RustcEncodable, RustcDecodable)]
300 pub struct Entry<'tcx> {
301 pub kind: EntryKind<'tcx>,
302 pub visibility: Lazy<ty::Visibility>,
303 pub span: Lazy<Span>,
304 pub attributes: LazySeq<ast::Attribute>,
305 pub children: LazySeq<DefIndex>,
306 pub stability: Option<Lazy<attr::Stability>>,
307 pub deprecation: Option<Lazy<attr::Deprecation>>,
309 pub ty: Option<Lazy<Ty<'tcx>>>,
310 pub inherent_impls: LazySeq<DefIndex>,
311 pub variances: LazySeq<ty::Variance>,
312 pub generics: Option<Lazy<ty::Generics>>,
313 pub predicates: Option<Lazy<ty::GenericPredicates<'tcx>>>,
315 pub ast: Option<Lazy<astencode::Ast<'tcx>>>,
316 pub mir: Option<Lazy<mir::Mir<'tcx>>>,
319 impl_stable_hash_for!(struct Entry<'tcx> {
336 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
337 pub enum EntryKind<'tcx> {
348 Variant(Lazy<VariantData<'tcx>>),
349 Struct(Lazy<VariantData<'tcx>>, ReprOptions),
350 Union(Lazy<VariantData<'tcx>>, ReprOptions),
351 Fn(Lazy<FnData<'tcx>>),
352 ForeignFn(Lazy<FnData<'tcx>>),
354 MacroDef(Lazy<MacroDef>),
355 Closure(Lazy<ClosureData<'tcx>>),
356 Trait(Lazy<TraitData<'tcx>>),
357 Impl(Lazy<ImplData<'tcx>>),
358 DefaultImpl(Lazy<ImplData<'tcx>>),
359 Method(Lazy<MethodData<'tcx>>),
360 AssociatedType(AssociatedContainer),
361 AssociatedConst(AssociatedContainer, u8),
364 impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for EntryKind<'tcx> {
365 fn hash_stable<W: StableHasherResult>(&self,
366 hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
367 hasher: &mut StableHasher<W>) {
368 mem::discriminant(self).hash_stable(hcx, hasher);
370 EntryKind::ImmStatic |
371 EntryKind::MutStatic |
372 EntryKind::ForeignImmStatic |
373 EntryKind::ForeignMutStatic |
374 EntryKind::ForeignMod |
375 EntryKind::GlobalAsm |
378 // Nothing else to hash here.
380 EntryKind::Const(qualif) => {
381 qualif.hash_stable(hcx, hasher);
383 EntryKind::Enum(ref repr_options) => {
384 repr_options.hash_stable(hcx, hasher);
386 EntryKind::Variant(ref variant_data) => {
387 variant_data.hash_stable(hcx, hasher);
389 EntryKind::Struct(ref variant_data, ref repr_options) |
390 EntryKind::Union(ref variant_data, ref repr_options) => {
391 variant_data.hash_stable(hcx, hasher);
392 repr_options.hash_stable(hcx, hasher);
394 EntryKind::Fn(ref fn_data) |
395 EntryKind::ForeignFn(ref fn_data) => {
396 fn_data.hash_stable(hcx, hasher);
398 EntryKind::Mod(ref mod_data) => {
399 mod_data.hash_stable(hcx, hasher);
401 EntryKind::MacroDef(ref macro_def) => {
402 macro_def.hash_stable(hcx, hasher);
404 EntryKind::Closure(closure_data) => {
405 closure_data.hash_stable(hcx, hasher);
407 EntryKind::Trait(ref trait_data) => {
408 trait_data.hash_stable(hcx, hasher);
410 EntryKind::DefaultImpl(ref impl_data) |
411 EntryKind::Impl(ref impl_data) => {
412 impl_data.hash_stable(hcx, hasher);
414 EntryKind::Method(ref method_data) => {
415 method_data.hash_stable(hcx, hasher);
417 EntryKind::AssociatedType(associated_container) => {
418 associated_container.hash_stable(hcx, hasher);
420 EntryKind::AssociatedConst(associated_container, qualif) => {
421 associated_container.hash_stable(hcx, hasher);
422 qualif.hash_stable(hcx, hasher);
428 #[derive(RustcEncodable, RustcDecodable)]
430 pub reexports: LazySeq<def::Export>,
433 impl_stable_hash_for!(struct ModData { reexports });
435 #[derive(RustcEncodable, RustcDecodable)]
436 pub struct MacroDef {
441 impl_stable_hash_for!(struct MacroDef { body, legacy });
443 #[derive(RustcEncodable, RustcDecodable)]
444 pub struct FnData<'tcx> {
445 pub constness: hir::Constness,
446 pub arg_names: LazySeq<ast::Name>,
447 pub sig: Lazy<ty::PolyFnSig<'tcx>>,
450 impl_stable_hash_for!(struct FnData<'tcx> { constness, arg_names, sig });
452 #[derive(RustcEncodable, RustcDecodable)]
453 pub struct VariantData<'tcx> {
454 pub ctor_kind: CtorKind,
455 pub discr: ty::VariantDiscr,
457 /// If this is a struct's only variant, this
458 /// is the index of the "struct ctor" item.
459 pub struct_ctor: Option<DefIndex>,
461 /// If this is a tuple struct or variant
462 /// ctor, this is its "function" signature.
463 pub ctor_sig: Option<Lazy<ty::PolyFnSig<'tcx>>>,
466 impl_stable_hash_for!(struct VariantData<'tcx> {
473 #[derive(RustcEncodable, RustcDecodable)]
474 pub struct TraitData<'tcx> {
475 pub unsafety: hir::Unsafety,
476 pub paren_sugar: bool,
477 pub has_default_impl: bool,
478 pub super_predicates: Lazy<ty::GenericPredicates<'tcx>>,
481 impl_stable_hash_for!(struct TraitData<'tcx> {
488 #[derive(RustcEncodable, RustcDecodable)]
489 pub struct ImplData<'tcx> {
490 pub polarity: hir::ImplPolarity,
491 pub defaultness: hir::Defaultness,
492 pub parent_impl: Option<DefId>,
494 /// This is `Some` only for impls of `CoerceUnsized`.
495 pub coerce_unsized_info: Option<ty::adjustment::CoerceUnsizedInfo>,
496 pub trait_ref: Option<Lazy<ty::TraitRef<'tcx>>>,
499 impl_stable_hash_for!(struct ImplData<'tcx> {
508 /// Describes whether the container of an associated item
509 /// is a trait or an impl and whether, in a trait, it has
510 /// a default, or an in impl, whether it's marked "default".
511 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
512 pub enum AssociatedContainer {
519 impl_stable_hash_for!(enum ::schema::AssociatedContainer {
526 impl AssociatedContainer {
527 pub fn with_def_id(&self, def_id: DefId) -> ty::AssociatedItemContainer {
529 AssociatedContainer::TraitRequired |
530 AssociatedContainer::TraitWithDefault => ty::TraitContainer(def_id),
532 AssociatedContainer::ImplDefault |
533 AssociatedContainer::ImplFinal => ty::ImplContainer(def_id),
537 pub fn defaultness(&self) -> hir::Defaultness {
539 AssociatedContainer::TraitRequired => hir::Defaultness::Default {
543 AssociatedContainer::TraitWithDefault |
544 AssociatedContainer::ImplDefault => hir::Defaultness::Default {
548 AssociatedContainer::ImplFinal => hir::Defaultness::Final,
553 #[derive(RustcEncodable, RustcDecodable)]
554 pub struct MethodData<'tcx> {
555 pub fn_data: FnData<'tcx>,
556 pub container: AssociatedContainer,
559 impl_stable_hash_for!(struct MethodData<'tcx> { fn_data, container, has_self });
561 #[derive(RustcEncodable, RustcDecodable)]
562 pub struct ClosureData<'tcx> {
563 pub kind: ty::ClosureKind,
564 pub sig: Lazy<ty::PolyFnSig<'tcx>>,
566 impl_stable_hash_for!(struct ClosureData<'tcx> { kind, sig });