2 use table::{Table, TableBuilder};
4 use rustc_ast::ast::{self, MacroDef};
5 use rustc_attr as attr;
6 use rustc_data_structures::svh::Svh;
7 use rustc_data_structures::sync::MetadataRef;
9 use rustc_hir::def::CtorKind;
10 use rustc_hir::def_id::{DefId, DefIndex};
11 use rustc_hir::lang_items;
12 use rustc_index::{bit_set::FiniteBitSet, vec::IndexVec};
13 use rustc_middle::hir::exports::Export;
14 use rustc_middle::middle::cstore::{CrateDepKind, ForeignModule, LinkagePreference, NativeLib};
15 use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
16 use rustc_middle::mir;
17 use rustc_middle::ty::{self, ReprOptions, Ty};
18 use rustc_serialize::opaque::Encoder;
19 use rustc_session::config::SymbolManglingVersion;
20 use rustc_session::CrateDisambiguator;
21 use rustc_span::edition::Edition;
22 use rustc_span::symbol::{Ident, Symbol};
23 use rustc_span::{self, ExpnData, ExpnId, Span};
24 use rustc_target::spec::{PanicStrategy, TargetTriple};
26 use std::marker::PhantomData;
27 use std::num::NonZeroUsize;
29 pub use decoder::{provide, provide_extern};
30 crate use decoder::{CrateMetadata, CrateNumMap, MetadataBlob};
31 use rustc_span::hygiene::SyntaxContextData;
37 crate fn rustc_version() -> String {
38 format!("rustc {}", option_env!("CFG_VERSION").unwrap_or("unknown version"))
41 /// Metadata encoding version.
42 /// N.B., 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 const METADATA_VERSION: u8 = 5;
46 /// Metadata header which includes `METADATA_VERSION`.
48 /// This header is followed by the position of the `CrateRoot`,
49 /// which is encoded as a 32-bit big-endian unsigned integer,
50 /// and further followed by the rustc version string.
51 crate const METADATA_HEADER: &[u8; 8] = &[b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
53 /// Additional metadata for a `Lazy<T>` where `T` may not be `Sized`,
54 /// e.g. for `Lazy<[T]>`, this is the length (count of `T` values).
56 type Meta: Copy + 'static;
58 /// Returns the minimum encoded size.
59 // FIXME(eddyb) Give better estimates for certain types.
60 fn min_size(meta: Self::Meta) -> usize;
63 impl<T> LazyMeta for T {
66 fn min_size(_: ()) -> usize {
67 assert_ne!(std::mem::size_of::<T>(), 0);
72 impl<T> LazyMeta for [T] {
75 fn min_size(len: usize) -> usize {
80 /// A value of type T referred to by its absolute position
81 /// in the metadata, and which can be decoded lazily.
83 /// Metadata is effective a tree, encoded in post-order,
84 /// and with the root's position written next to the header.
85 /// That means every single `Lazy` points to some previous
86 /// location in the metadata and is part of a larger node.
88 /// The first `Lazy` in a node is encoded as the backwards
89 /// distance from the position where the containing node
90 /// starts and where the `Lazy` points to, while the rest
91 /// use the forward distance from the previous `Lazy`.
92 /// Distances start at 1, as 0-byte nodes are invalid.
93 /// Also invalid are nodes being referred in a different
94 /// order than they were encoded in.
96 /// # Sequences (`Lazy<[T]>`)
98 /// Unlike `Lazy<Vec<T>>`, the length is encoded next to the
99 /// position, not at the position, which means that the length
100 /// doesn't need to be known before encoding all the elements.
102 /// If the length is 0, no position is encoded, but otherwise,
103 /// the encoding is that of `Lazy`, with the distinction that
104 /// the minimal distance the length of the sequence, i.e.
105 /// it's assumed there's no 0-byte element in the sequence.
107 // FIXME(#59875) the `Meta` parameter only exists to dodge
108 // invariance wrt `T` (coming from the `meta: T::Meta` field).
109 struct Lazy<T, Meta = <T as LazyMeta>::Meta>
111 T: ?Sized + LazyMeta<Meta = Meta>,
112 Meta: 'static + Copy,
114 position: NonZeroUsize,
116 _marker: PhantomData<T>,
119 impl<T: ?Sized + LazyMeta> Lazy<T> {
120 fn from_position_and_meta(position: NonZeroUsize, meta: T::Meta) -> Lazy<T> {
121 Lazy { position, meta, _marker: PhantomData }
126 fn from_position(position: NonZeroUsize) -> Lazy<T> {
127 Lazy::from_position_and_meta(position, ())
132 fn empty() -> Lazy<[T]> {
133 Lazy::from_position_and_meta(NonZeroUsize::new(1).unwrap(), 0)
137 impl<T: ?Sized + LazyMeta> Copy for Lazy<T> {}
138 impl<T: ?Sized + LazyMeta> Clone for Lazy<T> {
139 fn clone(&self) -> Self {
144 impl<T: ?Sized + LazyMeta> rustc_serialize::UseSpecializedEncodable for Lazy<T> {}
145 impl<T: ?Sized + LazyMeta> rustc_serialize::UseSpecializedDecodable for Lazy<T> {}
147 /// Encoding / decoding state for `Lazy`.
148 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
150 /// Outside of a metadata node.
153 /// Inside a metadata node, and before any `Lazy`.
154 /// The position is that of the node itself.
155 NodeStart(NonZeroUsize),
157 /// Inside a metadata node, with a previous `Lazy`.
158 /// The position is a conservative estimate of where that
159 /// previous `Lazy` would end (see their comments).
160 Previous(NonZeroUsize),
163 // FIXME(#59875) `Lazy!(T)` replaces `Lazy<T>`, passing the `Meta` parameter
164 // manually, instead of relying on the default, to get the correct variance.
165 // Only needed when `T` itself contains a parameter (e.g. `'tcx`).
167 (Table<$I:ty, $T:ty>) => {Lazy<Table<$I, $T>, usize>};
168 ([$T:ty]) => {Lazy<[$T], usize>};
169 ($T:ty) => {Lazy<$T, ()>};
172 type SyntaxContextTable = Lazy<Table<u32, Lazy<SyntaxContextData>>>;
173 type ExpnDataTable = Lazy<Table<u32, Lazy<ExpnData>>>;
175 #[derive(RustcEncodable, RustcDecodable)]
176 crate struct CrateRoot<'tcx> {
178 triple: TargetTriple,
179 extra_filename: String,
181 disambiguator: CrateDisambiguator,
182 panic_strategy: PanicStrategy,
184 has_global_allocator: bool,
185 has_panic_handler: bool,
186 has_default_lib_allocator: bool,
187 plugin_registrar_fn: Option<DefIndex>,
188 proc_macro_decls_static: Option<DefIndex>,
189 proc_macro_stability: Option<attr::Stability>,
191 crate_deps: Lazy<[CrateDep]>,
192 dylib_dependency_formats: Lazy<[Option<LinkagePreference>]>,
193 lib_features: Lazy<[(Symbol, Option<Symbol>)]>,
194 lang_items: Lazy<[(DefIndex, usize)]>,
195 lang_items_missing: Lazy<[lang_items::LangItem]>,
196 diagnostic_items: Lazy<[(Symbol, DefIndex)]>,
197 native_libraries: Lazy<[NativeLib]>,
198 foreign_modules: Lazy<[ForeignModule]>,
199 def_path_table: Lazy<rustc_hir::definitions::DefPathTable>,
200 impls: Lazy<[TraitImpls]>,
201 interpret_alloc_index: Lazy<[u32]>,
203 tables: LazyTables<'tcx>,
205 /// The DefIndex's of any proc macros declared by this crate.
206 proc_macro_data: Option<Lazy<[DefIndex]>>,
208 exported_symbols: Lazy!([(ExportedSymbol<'tcx>, SymbolExportLevel)]),
210 syntax_contexts: SyntaxContextTable,
211 expn_data: ExpnDataTable,
213 source_map: Lazy<[rustc_span::SourceFile]>,
215 compiler_builtins: bool,
216 needs_allocator: bool,
217 needs_panic_runtime: bool,
220 profiler_runtime: bool,
221 symbol_mangling_version: SymbolManglingVersion,
224 #[derive(RustcEncodable, RustcDecodable)]
225 crate struct CrateDep {
228 pub host_hash: Option<Svh>,
229 pub kind: CrateDepKind,
230 pub extra_filename: String,
233 #[derive(RustcEncodable, RustcDecodable)]
234 crate struct TraitImpls {
235 trait_id: (u32, DefIndex),
236 impls: Lazy<[DefIndex]>,
239 /// Define `LazyTables` and `TableBuilders` at the same time.
240 macro_rules! define_tables {
241 ($($name:ident: Table<DefIndex, $T:ty>),+ $(,)?) => {
242 #[derive(RustcEncodable, RustcDecodable)]
243 crate struct LazyTables<'tcx> {
244 $($name: Lazy!(Table<DefIndex, $T>)),+
248 struct TableBuilders<'tcx> {
249 $($name: TableBuilder<DefIndex, $T>),+
252 impl TableBuilders<'tcx> {
253 fn encode(&self, buf: &mut Encoder) -> LazyTables<'tcx> {
255 $($name: self.$name.encode(buf)),+
263 kind: Table<DefIndex, Lazy<EntryKind>>,
264 visibility: Table<DefIndex, Lazy<ty::Visibility>>,
265 span: Table<DefIndex, Lazy<Span>>,
266 ident_span: Table<DefIndex, Lazy<Span>>,
267 attributes: Table<DefIndex, Lazy<[ast::Attribute]>>,
268 children: Table<DefIndex, Lazy<[DefIndex]>>,
269 stability: Table<DefIndex, Lazy<attr::Stability>>,
270 const_stability: Table<DefIndex, Lazy<attr::ConstStability>>,
271 deprecation: Table<DefIndex, Lazy<attr::Deprecation>>,
272 ty: Table<DefIndex, Lazy!(Ty<'tcx>)>,
273 fn_sig: Table<DefIndex, Lazy!(ty::PolyFnSig<'tcx>)>,
274 impl_trait_ref: Table<DefIndex, Lazy!(ty::TraitRef<'tcx>)>,
275 inherent_impls: Table<DefIndex, Lazy<[DefIndex]>>,
276 variances: Table<DefIndex, Lazy<[ty::Variance]>>,
277 generics: Table<DefIndex, Lazy<ty::Generics>>,
278 explicit_predicates: Table<DefIndex, Lazy!(ty::GenericPredicates<'tcx>)>,
279 // FIXME(eddyb) this would ideally be `Lazy<[...]>` but `ty::Predicate`
280 // doesn't handle shorthands in its own (de)serialization impls,
281 // as it's an `enum` for which we want to derive (de)serialization,
282 // so the `ty::codec` APIs handle the whole `&'tcx [...]` at once.
283 // Also, as an optimization, a missing entry indicates an empty `&[]`.
284 inferred_outlives: Table<DefIndex, Lazy!(&'tcx [(ty::Predicate<'tcx>, Span)])>,
285 super_predicates: Table<DefIndex, Lazy!(ty::GenericPredicates<'tcx>)>,
286 mir: Table<DefIndex, Lazy!(mir::Body<'tcx>)>,
287 promoted_mir: Table<DefIndex, Lazy!(IndexVec<mir::Promoted, mir::Body<'tcx>>)>,
288 unused_generic_params: Table<DefIndex, Lazy<FiniteBitSet<u64>>>,
291 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
293 AnonConst(mir::ConstQualifs, Lazy<RenderedConst>),
294 Const(mir::ConstQualifs, Lazy<RenderedConst>),
308 Variant(Lazy<VariantData>),
309 Struct(Lazy<VariantData>, ReprOptions),
310 Union(Lazy<VariantData>, ReprOptions),
312 ForeignFn(Lazy<FnData>),
314 MacroDef(Lazy<MacroDef>),
316 Generator(hir::GeneratorKind),
317 Trait(Lazy<TraitData>),
318 Impl(Lazy<ImplData>),
319 AssocFn(Lazy<AssocFnData>),
320 AssocType(AssocContainer),
321 AssocConst(AssocContainer, mir::ConstQualifs, Lazy<RenderedConst>),
325 /// Contains a constant which has been rendered to a String.
327 #[derive(RustcEncodable, RustcDecodable)]
328 struct RenderedConst(String);
330 #[derive(RustcEncodable, RustcDecodable)]
332 reexports: Lazy<[Export<hir::HirId>]>,
336 #[derive(RustcEncodable, RustcDecodable)]
338 asyncness: hir::IsAsync,
339 constness: hir::Constness,
340 param_names: Lazy<[Ident]>,
343 #[derive(RustcEncodable, RustcDecodable)]
346 discr: ty::VariantDiscr,
347 /// If this is unit or tuple-variant/struct, then this is the index of the ctor id.
348 ctor: Option<DefIndex>,
349 is_non_exhaustive: bool,
352 #[derive(RustcEncodable, RustcDecodable)]
354 unsafety: hir::Unsafety,
358 specialization_kind: ty::trait_def::TraitSpecializationKind,
361 #[derive(RustcEncodable, RustcDecodable)]
363 polarity: ty::ImplPolarity,
364 defaultness: hir::Defaultness,
365 parent_impl: Option<DefId>,
367 /// This is `Some` only for impls of `CoerceUnsized`.
368 // FIXME(eddyb) perhaps compute this on the fly if cheap enough?
369 coerce_unsized_info: Option<ty::adjustment::CoerceUnsizedInfo>,
372 /// Describes whether the container of an associated item
373 /// is a trait or an impl and whether, in a trait, it has
374 /// a default, or an in impl, whether it's marked "default".
375 #[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
376 enum AssocContainer {
383 impl AssocContainer {
384 fn with_def_id(&self, def_id: DefId) -> ty::AssocItemContainer {
386 AssocContainer::TraitRequired | AssocContainer::TraitWithDefault => {
387 ty::TraitContainer(def_id)
390 AssocContainer::ImplDefault | AssocContainer::ImplFinal => ty::ImplContainer(def_id),
394 fn defaultness(&self) -> hir::Defaultness {
396 AssocContainer::TraitRequired => hir::Defaultness::Default { has_value: false },
398 AssocContainer::TraitWithDefault | AssocContainer::ImplDefault => {
399 hir::Defaultness::Default { has_value: true }
402 AssocContainer::ImplFinal => hir::Defaultness::Final,
407 #[derive(RustcEncodable, RustcDecodable)]
410 container: AssocContainer,
414 #[derive(RustcEncodable, RustcDecodable)]
415 struct GeneratorData<'tcx> {
416 layout: mir::GeneratorLayout<'tcx>,
419 // Tags used for encoding Spans:
420 const TAG_VALID_SPAN_LOCAL: u8 = 0;
421 const TAG_VALID_SPAN_FOREIGN: u8 = 1;
422 const TAG_INVALID_SPAN: u8 = 2;