1 use crate::creader::CrateMetadataRef;
3 use def_path_hash_map::DefPathHashMapRef;
4 use rustc_data_structures::fx::FxHashMap;
5 use table::TableBuilder;
8 use rustc_attr as attr;
9 use rustc_data_structures::svh::Svh;
10 use rustc_data_structures::sync::MetadataRef;
12 use rustc_hir::def::{CtorKind, DefKind};
13 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, DefPathHash, StableCrateId};
14 use rustc_hir::definitions::DefKey;
15 use rustc_hir::lang_items::LangItem;
16 use rustc_index::bit_set::BitSet;
17 use rustc_index::vec::IndexVec;
18 use rustc_middle::metadata::ModChild;
19 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
20 use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo};
21 use rustc_middle::middle::resolve_lifetime::ObjectLifetimeDefault;
22 use rustc_middle::mir;
23 use rustc_middle::ty::fast_reject::SimplifiedType;
24 use rustc_middle::ty::query::Providers;
25 use rustc_middle::ty::{self, ReprOptions, Ty, UnusedGenericParams};
26 use rustc_middle::ty::{DeducedParamAttrs, GeneratorDiagnosticData, ParameterizedOverTcx, TyCtxt};
27 use rustc_serialize::opaque::FileEncoder;
28 use rustc_session::config::SymbolManglingVersion;
29 use rustc_session::cstore::{CrateDepKind, ForeignModule, LinkagePreference, NativeLib};
30 use rustc_span::edition::Edition;
31 use rustc_span::hygiene::{ExpnIndex, MacroKind};
32 use rustc_span::symbol::{Ident, Symbol};
33 use rustc_span::{self, ExpnData, ExpnHash, ExpnId, Span};
34 use rustc_target::spec::{PanicStrategy, TargetTriple};
36 use std::marker::PhantomData;
37 use std::num::NonZeroUsize;
39 pub use decoder::provide_extern;
40 use decoder::DecodeContext;
41 pub(crate) use decoder::{CrateMetadata, CrateNumMap, MetadataBlob};
42 use encoder::EncodeContext;
43 pub use encoder::{encode_metadata, EncodedMetadata};
44 use rustc_span::hygiene::SyntaxContextData;
47 mod def_path_hash_map;
51 pub(crate) fn rustc_version() -> String {
52 format!("rustc {}", option_env!("CFG_VERSION").unwrap_or("unknown version"))
55 /// Metadata encoding version.
56 /// N.B., increment this if you change the format of metadata such that
57 /// the rustc version can't be found to compare with `rustc_version()`.
58 const METADATA_VERSION: u8 = 6;
60 /// Metadata header which includes `METADATA_VERSION`.
62 /// This header is followed by the position of the `CrateRoot`,
63 /// which is encoded as a 32-bit big-endian unsigned integer,
64 /// and further followed by the rustc version string.
65 pub const METADATA_HEADER: &[u8] = &[b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
67 /// A value of type T referred to by its absolute position
68 /// in the metadata, and which can be decoded lazily.
70 /// Metadata is effective a tree, encoded in post-order,
71 /// and with the root's position written next to the header.
72 /// That means every single `LazyValue` points to some previous
73 /// location in the metadata and is part of a larger node.
75 /// The first `LazyValue` in a node is encoded as the backwards
76 /// distance from the position where the containing node
77 /// starts and where the `LazyValue` points to, while the rest
78 /// use the forward distance from the previous `LazyValue`.
79 /// Distances start at 1, as 0-byte nodes are invalid.
80 /// Also invalid are nodes being referred in a different
81 /// order than they were encoded in.
84 position: NonZeroUsize,
85 _marker: PhantomData<fn() -> T>,
88 impl<T: ParameterizedOverTcx> ParameterizedOverTcx for LazyValue<T> {
89 type Value<'tcx> = LazyValue<T::Value<'tcx>>;
92 impl<T> LazyValue<T> {
93 fn from_position(position: NonZeroUsize) -> LazyValue<T> {
94 LazyValue { position, _marker: PhantomData }
98 /// A list of lazily-decoded values.
100 /// Unlike `LazyValue<Vec<T>>`, the length is encoded next to the
101 /// position, not at the position, which means that the length
102 /// doesn't need to be known before encoding all the elements.
104 /// If the length is 0, no position is encoded, but otherwise,
105 /// the encoding is that of `LazyArray`, with the distinction that
106 /// the minimal distance the length of the sequence, i.e.
107 /// it's assumed there's no 0-byte element in the sequence.
108 struct LazyArray<T> {
109 position: NonZeroUsize,
111 _marker: PhantomData<fn() -> T>,
114 impl<T: ParameterizedOverTcx> ParameterizedOverTcx for LazyArray<T> {
115 type Value<'tcx> = LazyArray<T::Value<'tcx>>;
118 impl<T> LazyArray<T> {
119 fn from_position_and_num_elems(position: NonZeroUsize, num_elems: usize) -> LazyArray<T> {
120 LazyArray { position, num_elems, _marker: PhantomData }
123 fn empty() -> LazyArray<T> {
124 LazyArray::from_position_and_num_elems(NonZeroUsize::new(1).unwrap(), 0)
128 /// A list of lazily-decoded values, with the added capability of random access.
130 /// Random-access table (i.e. offering constant-time `get`/`set`), similar to
131 /// `LazyArray<T>`, but without requiring encoding or decoding all the values
132 /// eagerly and in-order.
133 struct LazyTable<I, T> {
134 position: NonZeroUsize,
136 _marker: PhantomData<fn(I) -> T>,
139 impl<I: 'static, T: ParameterizedOverTcx> ParameterizedOverTcx for LazyTable<I, T> {
140 type Value<'tcx> = LazyTable<I, T::Value<'tcx>>;
143 impl<I, T> LazyTable<I, T> {
144 fn from_position_and_encoded_size(
145 position: NonZeroUsize,
147 ) -> LazyTable<I, T> {
148 LazyTable { position, encoded_size, _marker: PhantomData }
152 impl<T> Copy for LazyValue<T> {}
153 impl<T> Clone for LazyValue<T> {
154 fn clone(&self) -> Self {
159 impl<T> Copy for LazyArray<T> {}
160 impl<T> Clone for LazyArray<T> {
161 fn clone(&self) -> Self {
166 impl<I, T> Copy for LazyTable<I, T> {}
167 impl<I, T> Clone for LazyTable<I, T> {
168 fn clone(&self) -> Self {
173 /// Encoding / decoding state for `Lazy`s (`LazyValue`, `LazyArray`, and `LazyTable`).
174 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
176 /// Outside of a metadata node.
179 /// Inside a metadata node, and before any `Lazy`s.
180 /// The position is that of the node itself.
181 NodeStart(NonZeroUsize),
183 /// Inside a metadata node, with a previous `Lazy`s.
184 /// The position is where that previous `Lazy` would start.
185 Previous(NonZeroUsize),
188 type SyntaxContextTable = LazyTable<u32, LazyValue<SyntaxContextData>>;
189 type ExpnDataTable = LazyTable<ExpnIndex, LazyValue<ExpnData>>;
190 type ExpnHashTable = LazyTable<ExpnIndex, LazyValue<ExpnHash>>;
192 #[derive(MetadataEncodable, MetadataDecodable)]
193 pub(crate) struct ProcMacroData {
194 proc_macro_decls_static: DefIndex,
195 stability: Option<attr::Stability>,
196 macros: LazyArray<DefIndex>,
199 /// Serialized metadata for a crate.
200 /// When compiling a proc-macro crate, we encode many of
201 /// the `LazyArray<T>` fields as `Lazy::empty()`. This serves two purposes:
203 /// 1. We avoid performing unnecessary work. Proc-macro crates can only
204 /// export proc-macros functions, which are compiled into a shared library.
205 /// As a result, a large amount of the information we normally store
206 /// (e.g. optimized MIR) is unneeded by downstream crates.
207 /// 2. We avoid serializing invalid `CrateNum`s. When we deserialize
208 /// a proc-macro crate, we don't load any of its dependencies (since we
209 /// just need to invoke a native function from the shared library).
210 /// This means that any foreign `CrateNum`s that we serialize cannot be
211 /// deserialized, since we will not know how to map them into the current
212 /// compilation session. If we were to serialize a proc-macro crate like
213 /// a normal crate, much of what we serialized would be unusable in addition
215 #[derive(MetadataEncodable, MetadataDecodable)]
216 pub(crate) struct CrateRoot {
218 triple: TargetTriple,
219 extra_filename: String,
221 stable_crate_id: StableCrateId,
222 required_panic_strategy: Option<PanicStrategy>,
223 panic_in_drop_strategy: PanicStrategy,
225 has_global_allocator: bool,
226 has_alloc_error_handler: bool,
227 has_panic_handler: bool,
228 has_default_lib_allocator: bool,
230 crate_deps: LazyArray<CrateDep>,
231 dylib_dependency_formats: LazyArray<Option<LinkagePreference>>,
232 lib_features: LazyArray<(Symbol, Option<Symbol>)>,
233 stability_implications: LazyArray<(Symbol, Symbol)>,
234 lang_items: LazyArray<(DefIndex, LangItem)>,
235 lang_items_missing: LazyArray<LangItem>,
236 diagnostic_items: LazyArray<(Symbol, DefIndex)>,
237 native_libraries: LazyArray<NativeLib>,
238 foreign_modules: LazyArray<ForeignModule>,
239 traits: LazyArray<DefIndex>,
240 impls: LazyArray<TraitImpls>,
241 incoherent_impls: LazyArray<IncoherentImpls>,
242 interpret_alloc_index: LazyArray<u32>,
243 proc_macro_data: Option<ProcMacroData>,
246 debugger_visualizers: LazyArray<rustc_span::DebuggerVisualizerFile>,
248 exported_symbols: LazyArray<(ExportedSymbol<'static>, SymbolExportInfo)>,
250 syntax_contexts: SyntaxContextTable,
251 expn_data: ExpnDataTable,
252 expn_hashes: ExpnHashTable,
254 def_path_hash_map: LazyValue<DefPathHashMapRef<'static>>,
256 source_map: LazyTable<u32, LazyValue<rustc_span::SourceFile>>,
258 compiler_builtins: bool,
259 needs_allocator: bool,
260 needs_panic_runtime: bool,
263 profiler_runtime: bool,
264 symbol_mangling_version: SymbolManglingVersion,
267 /// On-disk representation of `DefId`.
268 /// This creates a type-safe way to enforce that we remap the CrateNum between the on-disk
269 /// representation and the compilation session.
270 #[derive(Copy, Clone)]
271 pub(crate) struct RawDefId {
276 impl Into<RawDefId> for DefId {
277 fn into(self) -> RawDefId {
278 RawDefId { krate: self.krate.as_u32(), index: self.index.as_u32() }
283 /// This exists so that `provide_one!` is happy
284 fn decode(self, meta: (CrateMetadataRef<'_>, TyCtxt<'_>)) -> DefId {
285 self.decode_from_cdata(meta.0)
288 fn decode_from_cdata(self, cdata: CrateMetadataRef<'_>) -> DefId {
289 let krate = CrateNum::from_u32(self.krate);
290 let krate = cdata.map_encoded_cnum_to_current(krate);
291 DefId { krate, index: DefIndex::from_u32(self.index) }
295 #[derive(Encodable, Decodable)]
296 pub(crate) struct CrateDep {
299 pub host_hash: Option<Svh>,
300 pub kind: CrateDepKind,
301 pub extra_filename: String,
304 #[derive(MetadataEncodable, MetadataDecodable)]
305 pub(crate) struct TraitImpls {
306 trait_id: (u32, DefIndex),
307 impls: LazyArray<(DefIndex, Option<SimplifiedType>)>,
310 #[derive(MetadataEncodable, MetadataDecodable)]
311 pub(crate) struct IncoherentImpls {
312 self_ty: SimplifiedType,
313 impls: LazyArray<DefIndex>,
316 /// Define `LazyTables` and `TableBuilders` at the same time.
317 macro_rules! define_tables {
318 ($($name:ident: Table<$IDX:ty, $T:ty>),+ $(,)?) => {
319 #[derive(MetadataEncodable, MetadataDecodable)]
320 pub(crate) struct LazyTables {
321 $($name: LazyTable<$IDX, $T>),+
325 struct TableBuilders {
326 $($name: TableBuilder<$IDX, $T>),+
330 fn encode(&self, buf: &mut FileEncoder) -> LazyTables {
332 $($name: self.$name.encode(buf)),+
340 attributes: Table<DefIndex, LazyArray<ast::Attribute>>,
341 children: Table<DefIndex, LazyArray<DefIndex>>,
343 opt_def_kind: Table<DefIndex, DefKind>,
344 visibility: Table<DefIndex, LazyValue<ty::Visibility<DefIndex>>>,
345 def_span: Table<DefIndex, LazyValue<Span>>,
346 def_ident_span: Table<DefIndex, LazyValue<Span>>,
347 lookup_stability: Table<DefIndex, LazyValue<attr::Stability>>,
348 lookup_const_stability: Table<DefIndex, LazyValue<attr::ConstStability>>,
349 lookup_default_body_stability: Table<DefIndex, LazyValue<attr::DefaultBodyStability>>,
350 lookup_deprecation_entry: Table<DefIndex, LazyValue<attr::Deprecation>>,
351 // As an optimization, a missing entry indicates an empty `&[]`.
352 explicit_item_bounds: Table<DefIndex, LazyArray<(ty::Predicate<'static>, Span)>>,
353 explicit_predicates_of: Table<DefIndex, LazyValue<ty::GenericPredicates<'static>>>,
354 generics_of: Table<DefIndex, LazyValue<ty::Generics>>,
355 // As an optimization, a missing entry indicates an empty `&[]`.
356 inferred_outlives_of: Table<DefIndex, LazyArray<(ty::Clause<'static>, Span)>>,
357 super_predicates_of: Table<DefIndex, LazyValue<ty::GenericPredicates<'static>>>,
358 type_of: Table<DefIndex, LazyValue<Ty<'static>>>,
359 variances_of: Table<DefIndex, LazyArray<ty::Variance>>,
360 fn_sig: Table<DefIndex, LazyValue<ty::PolyFnSig<'static>>>,
361 codegen_fn_attrs: Table<DefIndex, LazyValue<CodegenFnAttrs>>,
362 impl_trait_ref: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::TraitRef<'static>>>>,
363 const_param_default: Table<DefIndex, LazyValue<ty::EarlyBinder<rustc_middle::ty::Const<'static>>>>,
364 object_lifetime_default: Table<DefIndex, LazyValue<ObjectLifetimeDefault>>,
365 optimized_mir: Table<DefIndex, LazyValue<mir::Body<'static>>>,
366 mir_for_ctfe: Table<DefIndex, LazyValue<mir::Body<'static>>>,
367 promoted_mir: Table<DefIndex, LazyValue<IndexVec<mir::Promoted, mir::Body<'static>>>>,
368 // FIXME(compiler-errors): Why isn't this a LazyArray?
369 thir_abstract_const: Table<DefIndex, LazyValue<ty::Const<'static>>>,
370 impl_parent: Table<DefIndex, RawDefId>,
371 impl_polarity: Table<DefIndex, ty::ImplPolarity>,
372 constness: Table<DefIndex, hir::Constness>,
373 is_intrinsic: Table<DefIndex, ()>,
374 impl_defaultness: Table<DefIndex, hir::Defaultness>,
375 // FIXME(eddyb) perhaps compute this on the fly if cheap enough?
376 coerce_unsized_info: Table<DefIndex, LazyValue<ty::adjustment::CoerceUnsizedInfo>>,
377 mir_const_qualif: Table<DefIndex, LazyValue<mir::ConstQualifs>>,
378 rendered_const: Table<DefIndex, LazyValue<String>>,
379 asyncness: Table<DefIndex, hir::IsAsync>,
380 fn_arg_names: Table<DefIndex, LazyArray<Ident>>,
381 generator_kind: Table<DefIndex, LazyValue<hir::GeneratorKind>>,
382 trait_def: Table<DefIndex, LazyValue<ty::TraitDef>>,
384 trait_item_def_id: Table<DefIndex, RawDefId>,
385 inherent_impls: Table<DefIndex, LazyArray<DefIndex>>,
386 expn_that_defined: Table<DefIndex, LazyValue<ExpnId>>,
387 unused_generic_params: Table<DefIndex, LazyValue<UnusedGenericParams>>,
388 params_in_repr: Table<DefIndex, LazyValue<BitSet<u32>>>,
389 repr_options: Table<DefIndex, LazyValue<ReprOptions>>,
390 // `def_keys` and `def_path_hashes` represent a lazy version of a
391 // `DefPathTable`. This allows us to avoid deserializing an entire
392 // `DefPathTable` up front, since we may only ever use a few
393 // definitions from any given crate.
394 def_keys: Table<DefIndex, LazyValue<DefKey>>,
395 def_path_hashes: Table<DefIndex, DefPathHash>,
396 proc_macro_quoted_spans: Table<usize, LazyValue<Span>>,
397 generator_diagnostic_data: Table<DefIndex, LazyValue<GeneratorDiagnosticData<'static>>>,
398 attr_flags: Table<DefIndex, AttrFlags>,
399 variant_data: Table<DefIndex, LazyValue<VariantData>>,
400 assoc_container: Table<DefIndex, ty::AssocItemContainer>,
401 // Slot is full when macro is macro_rules.
402 macro_rules: Table<DefIndex, ()>,
403 macro_definition: Table<DefIndex, LazyValue<ast::DelimArgs>>,
404 proc_macro: Table<DefIndex, MacroKind>,
405 module_reexports: Table<DefIndex, LazyArray<ModChild>>,
406 deduced_param_attrs: Table<DefIndex, LazyArray<DeducedParamAttrs>>,
407 // Slot is full when opaque is TAIT.
408 is_type_alias_impl_trait: Table<DefIndex, ()>,
410 trait_impl_trait_tys: Table<DefIndex, LazyValue<FxHashMap<DefId, Ty<'static>>>>,
413 #[derive(TyEncodable, TyDecodable)]
415 discr: ty::VariantDiscr,
416 /// If this is unit or tuple-variant/struct, then this is the index of the ctor id.
417 ctor: Option<(CtorKind, DefIndex)>,
418 is_non_exhaustive: bool,
421 bitflags::bitflags! {
422 pub struct AttrFlags: u8 {
423 const MAY_HAVE_DOC_LINKS = 1 << 0;
424 const IS_DOC_HIDDEN = 1 << 1;
428 // Tags used for encoding Spans:
429 const TAG_VALID_SPAN_LOCAL: u8 = 0;
430 const TAG_VALID_SPAN_FOREIGN: u8 = 1;
431 const TAG_PARTIAL_SPAN: u8 = 2;
433 // Tags for encoding Symbol's
434 const SYMBOL_STR: u8 = 0;
435 const SYMBOL_OFFSET: u8 = 1;
436 const SYMBOL_PREINTERNED: u8 = 2;
438 pub fn provide(providers: &mut Providers) {
439 encoder::provide(providers);
440 decoder::provide(providers);
443 trivially_parameterized_over_tcx! {