1 use crate::rmeta::table::{FixedSizeEncoding, TableBuilder};
4 use log::{debug, trace};
6 use rustc_data_structures::fingerprint::Fingerprint;
7 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
8 use rustc_data_structures::stable_hasher::StableHasher;
9 use rustc_data_structures::sync::{join, Lrc};
11 use rustc_hir::def::CtorKind;
12 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
13 use rustc_hir::definitions::DefPathTable;
14 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
15 use rustc_hir::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor};
16 use rustc_hir::lang_items;
17 use rustc_hir::{AnonConst, GenericParamKind};
18 use rustc_index::bit_set::GrowableBitSet;
19 use rustc_index::vec::Idx;
20 use rustc_middle::hir::map::Map;
21 use rustc_middle::middle::cstore::{EncodedMetadata, ForeignModule, LinkagePreference, NativeLib};
22 use rustc_middle::middle::dependency_format::Linkage;
23 use rustc_middle::middle::exported_symbols::{
24 metadata_symbol_name, ExportedSymbol, SymbolExportLevel,
26 use rustc_middle::mir::{self, interpret};
27 use rustc_middle::traits::specialization_graph;
28 use rustc_middle::ty::codec::{self as ty_codec, TyEncoder};
29 use rustc_middle::ty::{self, SymbolName, Ty, TyCtxt};
30 use rustc_serialize::{opaque, Encodable, Encoder, SpecializedEncoder, UseSpecializedEncodable};
31 use rustc_session::config::CrateType;
32 use rustc_span::hygiene::{ExpnDataEncodeMode, HygieneEncodeContext};
33 use rustc_span::source_map::Spanned;
34 use rustc_span::symbol::{sym, Ident, Symbol};
35 use rustc_span::{self, ExternalSource, FileName, SourceFile, Span, SyntaxContext};
36 use rustc_target::abi::VariantIdx;
38 use std::num::NonZeroUsize;
41 struct EncodeContext<'a, 'tcx> {
42 opaque: opaque::Encoder,
45 tables: TableBuilders<'tcx>,
47 lazy_state: LazyState,
48 type_shorthands: FxHashMap<Ty<'tcx>, usize>,
49 predicate_shorthands: FxHashMap<ty::Predicate<'tcx>, usize>,
51 interpret_allocs: FxHashMap<interpret::AllocId, usize>,
52 interpret_allocs_inverse: Vec<interpret::AllocId>,
54 // This is used to speed up Span encoding.
55 // The `usize` is an index into the `MonotonicVec`
56 // that stores the `SourceFile`
57 source_file_cache: (Lrc<SourceFile>, usize),
58 // The indices (into the `SourceMap`'s `MonotonicVec`)
59 // of all of the `SourceFiles` that we need to serialize.
60 // When we serialize a `Span`, we insert the index of its
61 // `SourceFile` into the `GrowableBitSet`.
63 // This needs to be a `GrowableBitSet` and not a
64 // regular `BitSet` because we may actually import new `SourceFiles`
65 // during metadata encoding, due to executing a query
66 // with a result containing a foreign `Span`.
67 required_source_files: Option<GrowableBitSet<usize>>,
69 hygiene_ctxt: &'a HygieneEncodeContext,
72 macro_rules! encoder_methods {
73 ($($name:ident($ty:ty);)*) => {
74 $(fn $name(&mut self, value: $ty) -> Result<(), Self::Error> {
75 self.opaque.$name(value)
80 impl<'a, 'tcx> Encoder for EncodeContext<'a, 'tcx> {
81 type Error = <opaque::Encoder as Encoder>::Error;
84 fn emit_unit(&mut self) -> Result<(), Self::Error> {
111 impl<'a, 'tcx, T> SpecializedEncoder<Lazy<T, ()>> for EncodeContext<'a, 'tcx> {
112 fn specialized_encode(&mut self, lazy: &Lazy<T>) -> Result<(), Self::Error> {
113 self.emit_lazy_distance(*lazy)
117 impl<'a, 'tcx, T> SpecializedEncoder<Lazy<[T], usize>> for EncodeContext<'a, 'tcx> {
118 fn specialized_encode(&mut self, lazy: &Lazy<[T]>) -> Result<(), Self::Error> {
119 self.emit_usize(lazy.meta)?;
123 self.emit_lazy_distance(*lazy)
127 impl<'a, 'tcx, I: Idx, T> SpecializedEncoder<Lazy<Table<I, T>, usize>> for EncodeContext<'a, 'tcx>
129 Option<T>: FixedSizeEncoding,
131 fn specialized_encode(&mut self, lazy: &Lazy<Table<I, T>>) -> Result<(), Self::Error> {
132 self.emit_usize(lazy.meta)?;
133 self.emit_lazy_distance(*lazy)
137 impl<'a, 'tcx> SpecializedEncoder<CrateNum> for EncodeContext<'a, 'tcx> {
139 fn specialized_encode(&mut self, cnum: &CrateNum) -> Result<(), Self::Error> {
140 self.emit_u32(cnum.as_u32())
144 impl<'a, 'tcx> SpecializedEncoder<DefId> for EncodeContext<'a, 'tcx> {
146 fn specialized_encode(&mut self, def_id: &DefId) -> Result<(), Self::Error> {
147 let DefId { krate, index } = *def_id;
154 impl<'a, 'tcx> SpecializedEncoder<SyntaxContext> for EncodeContext<'a, 'tcx> {
155 fn specialized_encode(&mut self, ctxt: &SyntaxContext) -> Result<(), Self::Error> {
156 rustc_span::hygiene::raw_encode_syntax_context(*ctxt, &self.hygiene_ctxt, self)
160 impl<'a, 'tcx> SpecializedEncoder<ExpnId> for EncodeContext<'a, 'tcx> {
161 fn specialized_encode(&mut self, expn: &ExpnId) -> Result<(), Self::Error> {
162 rustc_span::hygiene::raw_encode_expn_id(
164 &mut self.hygiene_ctxt,
165 ExpnDataEncodeMode::Metadata,
171 impl<'a, 'tcx> SpecializedEncoder<DefIndex> for EncodeContext<'a, 'tcx> {
173 fn specialized_encode(&mut self, def_index: &DefIndex) -> Result<(), Self::Error> {
174 self.emit_u32(def_index.as_u32())
178 impl<'a, 'tcx> SpecializedEncoder<Span> for EncodeContext<'a, 'tcx> {
179 fn specialized_encode(&mut self, span: &Span) -> Result<(), Self::Error> {
181 return TAG_INVALID_SPAN.encode(self);
184 let span = span.data();
186 // The Span infrastructure should make sure that this invariant holds:
187 debug_assert!(span.lo <= span.hi);
189 if !self.source_file_cache.0.contains(span.lo) {
190 let source_map = self.tcx.sess.source_map();
191 let source_file_index = source_map.lookup_source_file_idx(span.lo);
192 self.source_file_cache =
193 (source_map.files()[source_file_index].clone(), source_file_index);
196 if !self.source_file_cache.0.contains(span.hi) {
197 // Unfortunately, macro expansion still sometimes generates Spans
198 // that malformed in this way.
199 return TAG_INVALID_SPAN.encode(self);
202 let source_files = self.required_source_files.as_mut().expect("Already encoded SourceMap!");
203 // Record the fact that we need to encode the data for this `SourceFile`
204 source_files.insert(self.source_file_cache.1);
206 // There are two possible cases here:
207 // 1. This span comes from a 'foreign' crate - e.g. some crate upstream of the
208 // crate we are writing metadata for. When the metadata for *this* crate gets
209 // deserialized, the deserializer will need to know which crate it originally came
210 // from. We use `TAG_VALID_SPAN_FOREIGN` to indicate that a `CrateNum` should
211 // be deserialized after the rest of the span data, which tells the deserializer
212 // which crate contains the source map information.
213 // 2. This span comes from our own crate. No special hamdling is needed - we just
214 // write `TAG_VALID_SPAN_LOCAL` to let the deserializer know that it should use
215 // our own source map information.
217 // If we're a proc-macro crate, we always treat this as a local `Span`.
218 // In `encode_source_map`, we serialize foreign `SourceFile`s into our metadata
219 // if we're a proc-macro crate.
220 // This allows us to avoid loading the dependencies of proc-macro crates: all of
221 // the information we need to decode `Span`s is stored in the proc-macro crate.
222 let (tag, lo, hi) = if self.source_file_cache.0.is_imported() && !self.is_proc_macro {
223 // To simplify deserialization, we 'rebase' this span onto the crate it originally came from
224 // (the crate that 'owns' the file it references. These rebased 'lo' and 'hi' values
225 // are relative to the source map information for the 'foreign' crate whose CrateNum
226 // we write into the metadata. This allows `imported_source_files` to binary
227 // search through the 'foreign' crate's source map information, using the
228 // deserialized 'lo' and 'hi' values directly.
230 // All of this logic ensures that the final result of deserialization is a 'normal'
231 // Span that can be used without any additional trouble.
232 let external_start_pos = {
233 // Introduce a new scope so that we drop the 'lock()' temporary
234 match &*self.source_file_cache.0.external_src.lock() {
235 ExternalSource::Foreign { original_start_pos, .. } => *original_start_pos,
236 src => panic!("Unexpected external source {:?}", src),
239 let lo = (span.lo - self.source_file_cache.0.start_pos) + external_start_pos;
240 let hi = (span.hi - self.source_file_cache.0.start_pos) + external_start_pos;
242 (TAG_VALID_SPAN_FOREIGN, lo, hi)
244 (TAG_VALID_SPAN_LOCAL, span.lo, span.hi)
250 // Encode length which is usually less than span.hi and profits more
251 // from the variable-length integer encoding that we use.
255 // Don't serialize any `SyntaxContext`s from a proc-macro crate,
256 // since we don't load proc-macro dependencies during serialization.
257 // This means that any hygiene information from macros used *within*
258 // a proc-macro crate (e.g. invoking a macro that expands to a proc-macro
259 // definition) will be lost.
261 // This can show up in two ways:
263 // 1. Any hygiene information associated with identifier of
264 // a proc macro (e.g. `#[proc_macro] pub fn $name`) will be lost.
265 // Since proc-macros can only be invoked from a different crate,
266 // real code should never need to care about this.
268 // 2. Using `Span::def_site` or `Span::mixed_site` will not
269 // include any hygiene information associated with the definition
270 // site. This means that a proc-macro cannot emit a `$crate`
271 // identifier which resolves to one of its dependencies,
272 // which also should never come up in practice.
274 // Additionally, this affects `Span::parent`, and any other
275 // span inspection APIs that would otherwise allow traversing
276 // the `SyntaxContexts` associated with a span.
278 // None of these user-visible effects should result in any
279 // cross-crate inconsistencies (getting one behavior in the same
280 // crate, and a different behavior in another crate) due to the
281 // limited surface that proc-macros can expose.
282 if self.is_proc_macro {
283 SyntaxContext::root().encode(self)?;
285 span.ctxt.encode(self)?;
288 if tag == TAG_VALID_SPAN_FOREIGN {
289 // This needs to be two lines to avoid holding the `self.source_file_cache`
290 // while calling `cnum.encode(self)`
291 let cnum = self.source_file_cache.0.cnum;
299 impl<'a, 'tcx> SpecializedEncoder<LocalDefId> for EncodeContext<'a, 'tcx> {
301 fn specialized_encode(&mut self, def_id: &LocalDefId) -> Result<(), Self::Error> {
302 self.specialized_encode(&def_id.to_def_id())
306 impl<'a, 'b, 'c, 'tcx> SpecializedEncoder<&'a ty::TyS<'b>> for EncodeContext<'c, 'tcx>
308 &'a ty::TyS<'b>: UseSpecializedEncodable,
310 fn specialized_encode(&mut self, ty: &&'a ty::TyS<'b>) -> Result<(), Self::Error> {
311 debug_assert!(self.tcx.lift(ty).is_some());
312 let ty = unsafe { std::mem::transmute::<&&'a ty::TyS<'b>, &&'tcx ty::TyS<'tcx>>(ty) };
313 ty_codec::encode_with_shorthand(self, ty, |ecx| &mut ecx.type_shorthands)
317 impl<'a, 'b, 'tcx> SpecializedEncoder<ty::Predicate<'b>> for EncodeContext<'a, 'tcx> {
318 fn specialized_encode(&mut self, predicate: &ty::Predicate<'b>) -> Result<(), Self::Error> {
319 debug_assert!(self.tcx.lift(predicate).is_some());
321 unsafe { std::mem::transmute::<&ty::Predicate<'b>, &ty::Predicate<'tcx>>(predicate) };
322 ty_codec::encode_with_shorthand(self, predicate, |encoder| {
323 &mut encoder.predicate_shorthands
328 impl<'a, 'tcx> SpecializedEncoder<interpret::AllocId> for EncodeContext<'a, 'tcx> {
329 fn specialized_encode(&mut self, alloc_id: &interpret::AllocId) -> Result<(), Self::Error> {
330 use std::collections::hash_map::Entry;
331 let index = match self.interpret_allocs.entry(*alloc_id) {
332 Entry::Occupied(e) => *e.get(),
333 Entry::Vacant(e) => {
334 let idx = self.interpret_allocs_inverse.len();
335 self.interpret_allocs_inverse.push(*alloc_id);
345 impl<'a, 'tcx> SpecializedEncoder<Fingerprint> for EncodeContext<'a, 'tcx> {
346 fn specialized_encode(&mut self, f: &Fingerprint) -> Result<(), Self::Error> {
347 f.encode_opaque(&mut self.opaque)
351 impl<'a, 'tcx, T> SpecializedEncoder<mir::ClearCrossCrate<T>> for EncodeContext<'a, 'tcx>
353 mir::ClearCrossCrate<T>: UseSpecializedEncodable,
355 fn specialized_encode(&mut self, _: &mir::ClearCrossCrate<T>) -> Result<(), Self::Error> {
360 impl<'a, 'tcx> TyEncoder for EncodeContext<'a, 'tcx> {
361 fn position(&self) -> usize {
362 self.opaque.position()
366 /// Helper trait to allow overloading `EncodeContext::lazy` for iterators.
367 trait EncodeContentsForLazy<T: ?Sized + LazyMeta> {
368 fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) -> T::Meta;
371 impl<T: Encodable> EncodeContentsForLazy<T> for &T {
372 fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) {
373 self.encode(ecx).unwrap()
377 impl<T: Encodable> EncodeContentsForLazy<T> for T {
378 fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) {
379 self.encode(ecx).unwrap()
383 impl<I, T: Encodable> EncodeContentsForLazy<[T]> for I
386 I::Item: EncodeContentsForLazy<T>,
388 fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) -> usize {
389 self.into_iter().map(|value| value.encode_contents_for_lazy(ecx)).count()
393 // Shorthand for `$self.$tables.$table.set($def_id.index, $self.lazy($value))`, which would
394 // normally need extra variables to avoid errors about multiple mutable borrows.
395 macro_rules! record {
396 ($self:ident.$tables:ident.$table:ident[$def_id:expr] <- $value:expr) => {{
399 let lazy = $self.lazy(value);
400 $self.$tables.$table.set($def_id.index, lazy);
405 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
406 fn emit_lazy_distance<T: ?Sized + LazyMeta>(
409 ) -> Result<(), <Self as Encoder>::Error> {
410 let min_end = lazy.position.get() + T::min_size(lazy.meta);
411 let distance = match self.lazy_state {
412 LazyState::NoNode => bug!("emit_lazy_distance: outside of a metadata node"),
413 LazyState::NodeStart(start) => {
414 let start = start.get();
415 assert!(min_end <= start);
418 LazyState::Previous(last_min_end) => {
420 last_min_end <= lazy.position,
421 "make sure that the calls to `lazy*` \
422 are in the same order as the metadata fields",
424 lazy.position.get() - last_min_end.get()
427 self.lazy_state = LazyState::Previous(NonZeroUsize::new(min_end).unwrap());
428 self.emit_usize(distance)
431 fn lazy<T: ?Sized + LazyMeta>(&mut self, value: impl EncodeContentsForLazy<T>) -> Lazy<T> {
432 let pos = NonZeroUsize::new(self.position()).unwrap();
434 assert_eq!(self.lazy_state, LazyState::NoNode);
435 self.lazy_state = LazyState::NodeStart(pos);
436 let meta = value.encode_contents_for_lazy(self);
437 self.lazy_state = LazyState::NoNode;
439 assert!(pos.get() + <T>::min_size(meta) <= self.position());
441 Lazy::from_position_and_meta(pos, meta)
444 fn encode_info_for_items(&mut self) {
445 let krate = self.tcx.hir().krate();
446 let vis = Spanned { span: rustc_span::DUMMY_SP, node: hir::VisibilityKind::Public };
447 self.encode_info_for_mod(hir::CRATE_HIR_ID, &krate.item.module, &krate.item.attrs, &vis);
448 krate.visit_all_item_likes(&mut self.as_deep_visitor());
449 for macro_def in krate.exported_macros {
450 self.visit_macro_def(macro_def);
454 fn encode_def_path_table(&mut self) -> Lazy<DefPathTable> {
455 let definitions = self.tcx.hir().definitions();
456 self.lazy(definitions.def_path_table())
459 fn encode_source_map(&mut self) -> Lazy<[rustc_span::SourceFile]> {
460 let source_map = self.tcx.sess.source_map();
461 let all_source_files = source_map.files();
463 let (working_dir, _cwd_remapped) = self.tcx.sess.working_dir.clone();
464 // By replacing the `Option` with `None`, we ensure that we can't
465 // accidentally serialize any more `Span`s after the source map encoding
467 let required_source_files = self.required_source_files.take().unwrap();
469 let adapted = all_source_files
472 .filter(|(idx, source_file)| {
473 // Only serialize `SourceFile`s that were used
474 // during the encoding of a `Span`
475 required_source_files.contains(*idx) &&
476 // Don't serialize imported `SourceFile`s, unless
477 // we're in a proc-macro crate.
478 (!source_file.is_imported() || self.is_proc_macro)
480 .map(|(_, source_file)| {
481 let mut adapted = match source_file.name {
482 // This path of this SourceFile has been modified by
483 // path-remapping, so we use it verbatim (and avoid
484 // cloning the whole map in the process).
485 _ if source_file.name_was_remapped => source_file.clone(),
487 // Otherwise expand all paths to absolute paths because
488 // any relative paths are potentially relative to a
490 FileName::Real(ref name) => {
491 let name = name.stable_name();
492 let mut adapted = (**source_file).clone();
493 adapted.name = Path::new(&working_dir).join(name).into();
494 adapted.name_hash = {
495 let mut hasher: StableHasher = StableHasher::new();
496 adapted.name.hash(&mut hasher);
497 hasher.finish::<u128>()
502 // expanded code, not from a file
503 _ => source_file.clone(),
506 // We're serializing this `SourceFile` into our crate metadata,
507 // so mark it as coming from this crate.
508 // This also ensures that we don't try to deserialize the
509 // `CrateNum` for a proc-macro dependency - since proc macro
510 // dependencies aren't loaded when we deserialize a proc-macro,
511 // trying to remap the `CrateNum` would fail.
512 if self.is_proc_macro {
513 Lrc::make_mut(&mut adapted).cnum = LOCAL_CRATE;
517 .collect::<Vec<_>>();
519 self.lazy(adapted.iter().map(|rc| &**rc))
522 fn is_proc_macro(&self) -> bool {
523 self.tcx.sess.crate_types().contains(&CrateType::ProcMacro)
526 fn encode_crate_root(&mut self) -> Lazy<CrateRoot<'tcx>> {
527 let is_proc_macro = self.is_proc_macro();
529 let mut i = self.position();
531 // Encode the crate deps
532 let crate_deps = self.encode_crate_deps();
533 let dylib_dependency_formats = self.encode_dylib_dependency_formats();
534 let dep_bytes = self.position() - i;
536 // Encode the lib features.
538 let lib_features = self.encode_lib_features();
539 let lib_feature_bytes = self.position() - i;
541 // Encode the language items.
543 let lang_items = self.encode_lang_items();
544 let lang_items_missing = self.encode_lang_items_missing();
545 let lang_item_bytes = self.position() - i;
547 // Encode the diagnostic items.
549 let diagnostic_items = self.encode_diagnostic_items();
550 let diagnostic_item_bytes = self.position() - i;
552 // Encode the native libraries used
554 let native_libraries = self.encode_native_libraries();
555 let native_lib_bytes = self.position() - i;
557 let foreign_modules = self.encode_foreign_modules();
559 // Encode DefPathTable
561 let def_path_table = self.encode_def_path_table();
562 let def_path_table_bytes = self.position() - i;
564 // Encode the def IDs of impls, for coherence checking.
566 let impls = self.encode_impls();
567 let impl_bytes = self.position() - i;
573 self.encode_info_for_items();
574 let item_bytes = self.position() - i;
576 // Encode the allocation index
577 let interpret_alloc_index = {
578 let mut interpret_alloc_index = Vec::new();
580 trace!("beginning to encode alloc ids");
582 let new_n = self.interpret_allocs_inverse.len();
583 // if we have found new ids, serialize those, too
588 trace!("encoding {} further alloc ids", new_n - n);
589 for idx in n..new_n {
590 let id = self.interpret_allocs_inverse[idx];
591 let pos = self.position() as u32;
592 interpret_alloc_index.push(pos);
593 interpret::specialized_encode_alloc_id(self, tcx, id).unwrap();
597 self.lazy(interpret_alloc_index)
601 let tables = self.tables.encode(&mut self.opaque);
602 let tables_bytes = self.position() - i;
604 // Encode the proc macro data
606 let proc_macro_data = self.encode_proc_macros();
607 let proc_macro_data_bytes = self.position() - i;
609 // Encode exported symbols info. This is prefetched in `encode_metadata` so we encode
610 // this as late as possible to give the prefetching as much time as possible to complete.
612 let exported_symbols = tcx.exported_symbols(LOCAL_CRATE);
613 let exported_symbols = self.encode_exported_symbols(&exported_symbols);
614 let exported_symbols_bytes = self.position() - i;
616 // Encode the hygiene data,
617 // IMPORTANT: this *must* be the last thing that we encode (other than `SourceMap`). The process
618 // of encoding other items (e.g. `optimized_mir`) may cause us to load
619 // data from the incremental cache. If this causes us to deserialize a `Span`,
620 // then we may load additional `SyntaxContext`s into the global `HygieneData`.
621 // Therefore, we need to encode the hygiene data last to ensure that we encode
622 // any `SyntaxContext`s that might be used.
624 let (syntax_contexts, expn_data) = self.encode_hygiene();
625 let hygiene_bytes = self.position() - i;
627 // Encode source_map. This needs to be done last,
628 // since encoding `Span`s tells us which `SourceFiles` we actually
631 let source_map = self.encode_source_map();
632 let source_map_bytes = self.position() - i;
634 let attrs = tcx.hir().krate_attrs();
635 let has_default_lib_allocator = tcx.sess.contains_name(&attrs, sym::default_lib_allocator);
637 let root = self.lazy(CrateRoot {
638 name: tcx.crate_name(LOCAL_CRATE),
639 extra_filename: tcx.sess.opts.cg.extra_filename.clone(),
640 triple: tcx.sess.opts.target_triple.clone(),
641 hash: tcx.crate_hash(LOCAL_CRATE),
642 disambiguator: tcx.sess.local_crate_disambiguator(),
643 panic_strategy: tcx.sess.panic_strategy(),
644 edition: tcx.sess.edition(),
645 has_global_allocator: tcx.has_global_allocator(LOCAL_CRATE),
646 has_panic_handler: tcx.has_panic_handler(LOCAL_CRATE),
647 has_default_lib_allocator,
648 plugin_registrar_fn: tcx.plugin_registrar_fn(LOCAL_CRATE).map(|id| id.index),
649 proc_macro_decls_static: if is_proc_macro {
650 let id = tcx.proc_macro_decls_static(LOCAL_CRATE).unwrap();
656 proc_macro_stability: if is_proc_macro {
657 tcx.lookup_stability(DefId::local(CRATE_DEF_INDEX)).copied()
661 compiler_builtins: tcx.sess.contains_name(&attrs, sym::compiler_builtins),
662 needs_allocator: tcx.sess.contains_name(&attrs, sym::needs_allocator),
663 needs_panic_runtime: tcx.sess.contains_name(&attrs, sym::needs_panic_runtime),
664 no_builtins: tcx.sess.contains_name(&attrs, sym::no_builtins),
665 panic_runtime: tcx.sess.contains_name(&attrs, sym::panic_runtime),
666 profiler_runtime: tcx.sess.contains_name(&attrs, sym::profiler_runtime),
667 symbol_mangling_version: tcx.sess.opts.debugging_opts.symbol_mangling_version,
670 dylib_dependency_formats,
681 interpret_alloc_index,
687 let total_bytes = self.position();
689 if tcx.sess.meta_stats() {
690 let mut zero_bytes = 0;
691 for e in self.opaque.data.iter() {
697 println!("metadata stats:");
698 println!(" dep bytes: {}", dep_bytes);
699 println!(" lib feature bytes: {}", lib_feature_bytes);
700 println!(" lang item bytes: {}", lang_item_bytes);
701 println!(" diagnostic item bytes: {}", diagnostic_item_bytes);
702 println!(" native bytes: {}", native_lib_bytes);
703 println!(" source_map bytes: {}", source_map_bytes);
704 println!(" impl bytes: {}", impl_bytes);
705 println!(" exp. symbols bytes: {}", exported_symbols_bytes);
706 println!(" def-path table bytes: {}", def_path_table_bytes);
707 println!(" proc-macro-data-bytes: {}", proc_macro_data_bytes);
708 println!(" item bytes: {}", item_bytes);
709 println!(" table bytes: {}", tables_bytes);
710 println!(" hygiene bytes: {}", hygiene_bytes);
711 println!(" zero bytes: {}", zero_bytes);
712 println!(" total bytes: {}", total_bytes);
719 impl EncodeContext<'a, 'tcx> {
720 fn encode_variances_of(&mut self, def_id: DefId) {
721 debug!("EncodeContext::encode_variances_of({:?})", def_id);
722 record!(self.tables.variances[def_id] <- &self.tcx.variances_of(def_id)[..]);
725 fn encode_item_type(&mut self, def_id: DefId) {
726 debug!("EncodeContext::encode_item_type({:?})", def_id);
727 record!(self.tables.ty[def_id] <- self.tcx.type_of(def_id));
730 fn encode_enum_variant_info(&mut self, def: &ty::AdtDef, index: VariantIdx) {
732 let variant = &def.variants[index];
733 let def_id = variant.def_id;
734 debug!("EncodeContext::encode_enum_variant_info({:?})", def_id);
736 let data = VariantData {
737 ctor_kind: variant.ctor_kind,
738 discr: variant.discr,
739 ctor: variant.ctor_def_id.map(|did| did.index),
740 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
743 let enum_id = tcx.hir().as_local_hir_id(def.did.expect_local());
744 let enum_vis = &tcx.hir().expect_item(enum_id).vis;
746 record!(self.tables.kind[def_id] <- EntryKind::Variant(self.lazy(data)));
747 record!(self.tables.visibility[def_id] <-
748 ty::Visibility::from_hir(enum_vis, enum_id, self.tcx));
749 record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
750 record!(self.tables.attributes[def_id] <- &self.tcx.get_attrs(def_id)[..]);
751 record!(self.tables.children[def_id] <- variant.fields.iter().map(|f| {
752 assert!(f.did.is_local());
755 self.encode_ident_span(def_id, variant.ident);
756 self.encode_stability(def_id);
757 self.encode_deprecation(def_id);
758 self.encode_item_type(def_id);
759 if variant.ctor_kind == CtorKind::Fn {
760 // FIXME(eddyb) encode signature only in `encode_enum_variant_ctor`.
761 if let Some(ctor_def_id) = variant.ctor_def_id {
762 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(ctor_def_id));
764 // FIXME(eddyb) is this ever used?
765 self.encode_variances_of(def_id);
767 self.encode_generics(def_id);
768 self.encode_explicit_predicates(def_id);
769 self.encode_inferred_outlives(def_id);
770 self.encode_optimized_mir(def_id.expect_local());
771 self.encode_promoted_mir(def_id.expect_local());
774 fn encode_enum_variant_ctor(&mut self, def: &ty::AdtDef, index: VariantIdx) {
776 let variant = &def.variants[index];
777 let def_id = variant.ctor_def_id.unwrap();
778 debug!("EncodeContext::encode_enum_variant_ctor({:?})", def_id);
780 // FIXME(eddyb) encode only the `CtorKind` for constructors.
781 let data = VariantData {
782 ctor_kind: variant.ctor_kind,
783 discr: variant.discr,
784 ctor: Some(def_id.index),
785 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
788 // Variant constructors have the same visibility as the parent enums, unless marked as
789 // non-exhaustive, in which case they are lowered to `pub(crate)`.
790 let enum_id = tcx.hir().as_local_hir_id(def.did.expect_local());
791 let enum_vis = &tcx.hir().expect_item(enum_id).vis;
792 let mut ctor_vis = ty::Visibility::from_hir(enum_vis, enum_id, tcx);
793 if variant.is_field_list_non_exhaustive() && ctor_vis == ty::Visibility::Public {
794 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
797 record!(self.tables.kind[def_id] <- EntryKind::Variant(self.lazy(data)));
798 record!(self.tables.visibility[def_id] <- ctor_vis);
799 record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
800 self.encode_stability(def_id);
801 self.encode_deprecation(def_id);
802 self.encode_item_type(def_id);
803 if variant.ctor_kind == CtorKind::Fn {
804 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
805 self.encode_variances_of(def_id);
807 self.encode_generics(def_id);
808 self.encode_explicit_predicates(def_id);
809 self.encode_inferred_outlives(def_id);
810 self.encode_optimized_mir(def_id.expect_local());
811 self.encode_promoted_mir(def_id.expect_local());
814 fn encode_info_for_mod(
818 attrs: &[ast::Attribute],
819 vis: &hir::Visibility<'_>,
822 let local_def_id = tcx.hir().local_def_id(id);
823 let def_id = local_def_id.to_def_id();
824 debug!("EncodeContext::encode_info_for_mod({:?})", def_id);
827 reexports: match tcx.module_exports(local_def_id) {
829 let hir_map = self.tcx.hir();
833 .map(|export| export.map_id(|id| hir_map.as_local_hir_id(id))),
838 expansion: tcx.hir().definitions().expansion_that_defined(local_def_id),
841 record!(self.tables.kind[def_id] <- EntryKind::Mod(self.lazy(data)));
842 record!(self.tables.visibility[def_id] <- ty::Visibility::from_hir(vis, id, self.tcx));
843 record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
844 record!(self.tables.attributes[def_id] <- attrs);
845 record!(self.tables.children[def_id] <- md.item_ids.iter().map(|item_id| {
846 tcx.hir().local_def_id(item_id.id).local_def_index
848 self.encode_stability(def_id);
849 self.encode_deprecation(def_id);
854 adt_def: &ty::AdtDef,
855 variant_index: VariantIdx,
859 let variant = &adt_def.variants[variant_index];
860 let field = &variant.fields[field_index];
862 let def_id = field.did;
863 debug!("EncodeContext::encode_field({:?})", def_id);
865 let variant_id = tcx.hir().as_local_hir_id(variant.def_id.expect_local());
866 let variant_data = tcx.hir().expect_variant_data(variant_id);
868 record!(self.tables.kind[def_id] <- EntryKind::Field);
869 record!(self.tables.visibility[def_id] <- field.vis);
870 record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
871 record!(self.tables.attributes[def_id] <- variant_data.fields()[field_index].attrs);
872 self.encode_ident_span(def_id, field.ident);
873 self.encode_stability(def_id);
874 self.encode_deprecation(def_id);
875 self.encode_item_type(def_id);
876 self.encode_generics(def_id);
877 self.encode_explicit_predicates(def_id);
878 self.encode_inferred_outlives(def_id);
881 fn encode_struct_ctor(&mut self, adt_def: &ty::AdtDef, def_id: DefId) {
882 debug!("EncodeContext::encode_struct_ctor({:?})", def_id);
884 let variant = adt_def.non_enum_variant();
886 let data = VariantData {
887 ctor_kind: variant.ctor_kind,
888 discr: variant.discr,
889 ctor: Some(def_id.index),
890 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
893 let struct_id = tcx.hir().as_local_hir_id(adt_def.did.expect_local());
894 let struct_vis = &tcx.hir().expect_item(struct_id).vis;
895 let mut ctor_vis = ty::Visibility::from_hir(struct_vis, struct_id, tcx);
896 for field in &variant.fields {
897 if ctor_vis.is_at_least(field.vis, tcx) {
898 ctor_vis = field.vis;
902 // If the structure is marked as non_exhaustive then lower the visibility
903 // to within the crate.
904 if adt_def.non_enum_variant().is_field_list_non_exhaustive()
905 && ctor_vis == ty::Visibility::Public
907 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
910 record!(self.tables.kind[def_id] <- EntryKind::Struct(self.lazy(data), adt_def.repr));
911 record!(self.tables.visibility[def_id] <- ctor_vis);
912 record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
913 self.encode_stability(def_id);
914 self.encode_deprecation(def_id);
915 self.encode_item_type(def_id);
916 if variant.ctor_kind == CtorKind::Fn {
917 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
918 self.encode_variances_of(def_id);
920 self.encode_generics(def_id);
921 self.encode_explicit_predicates(def_id);
922 self.encode_inferred_outlives(def_id);
923 self.encode_optimized_mir(def_id.expect_local());
924 self.encode_promoted_mir(def_id.expect_local());
927 fn encode_generics(&mut self, def_id: DefId) {
928 debug!("EncodeContext::encode_generics({:?})", def_id);
929 record!(self.tables.generics[def_id] <- self.tcx.generics_of(def_id));
932 fn encode_explicit_predicates(&mut self, def_id: DefId) {
933 debug!("EncodeContext::encode_explicit_predicates({:?})", def_id);
934 record!(self.tables.explicit_predicates[def_id] <-
935 self.tcx.explicit_predicates_of(def_id));
938 fn encode_inferred_outlives(&mut self, def_id: DefId) {
939 debug!("EncodeContext::encode_inferred_outlives({:?})", def_id);
940 let inferred_outlives = self.tcx.inferred_outlives_of(def_id);
941 if !inferred_outlives.is_empty() {
942 record!(self.tables.inferred_outlives[def_id] <- inferred_outlives);
946 fn encode_super_predicates(&mut self, def_id: DefId) {
947 debug!("EncodeContext::encode_super_predicates({:?})", def_id);
948 record!(self.tables.super_predicates[def_id] <- self.tcx.super_predicates_of(def_id));
951 fn encode_info_for_trait_item(&mut self, def_id: DefId) {
952 debug!("EncodeContext::encode_info_for_trait_item({:?})", def_id);
955 let hir_id = tcx.hir().as_local_hir_id(def_id.expect_local());
956 let ast_item = tcx.hir().expect_trait_item(hir_id);
957 let trait_item = tcx.associated_item(def_id);
959 let container = match trait_item.defaultness {
960 hir::Defaultness::Default { has_value: true } => AssocContainer::TraitWithDefault,
961 hir::Defaultness::Default { has_value: false } => AssocContainer::TraitRequired,
962 hir::Defaultness::Final => span_bug!(ast_item.span, "traits cannot have final items"),
965 record!(self.tables.kind[def_id] <- match trait_item.kind {
966 ty::AssocKind::Const => {
967 let rendered = rustc_hir_pretty::to_string(
968 &(&self.tcx.hir() as &dyn intravisit::Map<'_>),
969 |s| s.print_trait_item(ast_item)
971 let rendered_const = self.lazy(RenderedConst(rendered));
973 EntryKind::AssocConst(
979 ty::AssocKind::Fn => {
980 let fn_data = if let hir::TraitItemKind::Fn(m_sig, m) = &ast_item.kind {
981 let param_names = match *m {
982 hir::TraitFn::Required(ref names) => {
983 self.encode_fn_param_names(names)
985 hir::TraitFn::Provided(body) => {
986 self.encode_fn_param_names_for_body(body)
990 asyncness: m_sig.header.asyncness,
991 constness: hir::Constness::NotConst,
997 EntryKind::AssocFn(self.lazy(AssocFnData {
1000 has_self: trait_item.fn_has_self_parameter,
1003 ty::AssocKind::Type => EntryKind::AssocType(container),
1005 record!(self.tables.visibility[def_id] <- trait_item.vis);
1006 record!(self.tables.span[def_id] <- ast_item.span);
1007 record!(self.tables.attributes[def_id] <- ast_item.attrs);
1008 self.encode_ident_span(def_id, ast_item.ident);
1009 self.encode_stability(def_id);
1010 self.encode_const_stability(def_id);
1011 self.encode_deprecation(def_id);
1012 match trait_item.kind {
1013 ty::AssocKind::Const | ty::AssocKind::Fn => {
1014 self.encode_item_type(def_id);
1016 ty::AssocKind::Type => {
1017 if trait_item.defaultness.has_value() {
1018 self.encode_item_type(def_id);
1022 if trait_item.kind == ty::AssocKind::Fn {
1023 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1024 self.encode_variances_of(def_id);
1026 self.encode_generics(def_id);
1027 self.encode_explicit_predicates(def_id);
1028 self.encode_inferred_outlives(def_id);
1030 // This should be kept in sync with `PrefetchVisitor.visit_trait_item`.
1031 self.encode_optimized_mir(def_id.expect_local());
1032 self.encode_promoted_mir(def_id.expect_local());
1035 fn metadata_output_only(&self) -> bool {
1036 // MIR optimisation can be skipped when we're just interested in the metadata.
1037 !self.tcx.sess.opts.output_types.should_codegen()
1040 fn encode_info_for_impl_item(&mut self, def_id: DefId) {
1041 debug!("EncodeContext::encode_info_for_impl_item({:?})", def_id);
1044 let hir_id = self.tcx.hir().as_local_hir_id(def_id.expect_local());
1045 let ast_item = self.tcx.hir().expect_impl_item(hir_id);
1046 let impl_item = self.tcx.associated_item(def_id);
1048 let container = match impl_item.defaultness {
1049 hir::Defaultness::Default { has_value: true } => AssocContainer::ImplDefault,
1050 hir::Defaultness::Final => AssocContainer::ImplFinal,
1051 hir::Defaultness::Default { has_value: false } => {
1052 span_bug!(ast_item.span, "impl items always have values (currently)")
1056 record!(self.tables.kind[def_id] <- match impl_item.kind {
1057 ty::AssocKind::Const => {
1058 if let hir::ImplItemKind::Const(_, body_id) = ast_item.kind {
1059 let qualifs = self.tcx.at(ast_item.span).mir_const_qualif(def_id);
1061 EntryKind::AssocConst(
1064 self.encode_rendered_const_for_body(body_id))
1069 ty::AssocKind::Fn => {
1070 let fn_data = if let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind {
1072 asyncness: sig.header.asyncness,
1073 constness: sig.header.constness,
1074 param_names: self.encode_fn_param_names_for_body(body),
1079 EntryKind::AssocFn(self.lazy(AssocFnData {
1082 has_self: impl_item.fn_has_self_parameter,
1085 ty::AssocKind::Type => EntryKind::AssocType(container)
1087 record!(self.tables.visibility[def_id] <- impl_item.vis);
1088 record!(self.tables.span[def_id] <- ast_item.span);
1089 record!(self.tables.attributes[def_id] <- ast_item.attrs);
1090 self.encode_ident_span(def_id, impl_item.ident);
1091 self.encode_stability(def_id);
1092 self.encode_const_stability(def_id);
1093 self.encode_deprecation(def_id);
1094 self.encode_item_type(def_id);
1095 if impl_item.kind == ty::AssocKind::Fn {
1096 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1097 self.encode_variances_of(def_id);
1099 self.encode_generics(def_id);
1100 self.encode_explicit_predicates(def_id);
1101 self.encode_inferred_outlives(def_id);
1103 // The following part should be kept in sync with `PrefetchVisitor.visit_impl_item`.
1105 let mir = match ast_item.kind {
1106 hir::ImplItemKind::Const(..) => true,
1107 hir::ImplItemKind::Fn(ref sig, _) => {
1108 let generics = self.tcx.generics_of(def_id);
1109 let needs_inline = (generics.requires_monomorphization(self.tcx)
1110 || tcx.codegen_fn_attrs(def_id).requests_inline())
1111 && !self.metadata_output_only();
1112 let is_const_fn = sig.header.constness == hir::Constness::Const;
1113 let always_encode_mir = self.tcx.sess.opts.debugging_opts.always_encode_mir;
1114 needs_inline || is_const_fn || always_encode_mir
1116 hir::ImplItemKind::TyAlias(..) => false,
1119 self.encode_optimized_mir(def_id.expect_local());
1120 self.encode_promoted_mir(def_id.expect_local());
1124 fn encode_fn_param_names_for_body(&mut self, body_id: hir::BodyId) -> Lazy<[Ident]> {
1125 self.tcx.dep_graph.with_ignore(|| self.lazy(self.tcx.hir().body_param_names(body_id)))
1128 fn encode_fn_param_names(&mut self, param_names: &[Ident]) -> Lazy<[Ident]> {
1129 self.lazy(param_names.iter())
1132 fn encode_optimized_mir(&mut self, def_id: LocalDefId) {
1133 debug!("EntryBuilder::encode_mir({:?})", def_id);
1134 if self.tcx.mir_keys(LOCAL_CRATE).contains(&def_id) {
1135 record!(self.tables.mir[def_id.to_def_id()] <- self.tcx.optimized_mir(def_id));
1137 let unused = self.tcx.unused_generic_params(def_id);
1138 if !unused.is_empty() {
1139 record!(self.tables.unused_generic_params[def_id.to_def_id()] <- unused);
1144 fn encode_promoted_mir(&mut self, def_id: LocalDefId) {
1145 debug!("EncodeContext::encode_promoted_mir({:?})", def_id);
1146 if self.tcx.mir_keys(LOCAL_CRATE).contains(&def_id) {
1147 record!(self.tables.promoted_mir[def_id.to_def_id()] <- self.tcx.promoted_mir(def_id));
1151 // Encodes the inherent implementations of a structure, enumeration, or trait.
1152 fn encode_inherent_implementations(&mut self, def_id: DefId) {
1153 debug!("EncodeContext::encode_inherent_implementations({:?})", def_id);
1154 let implementations = self.tcx.inherent_impls(def_id);
1155 if !implementations.is_empty() {
1156 record!(self.tables.inherent_impls[def_id] <- implementations.iter().map(|&def_id| {
1157 assert!(def_id.is_local());
1163 fn encode_stability(&mut self, def_id: DefId) {
1164 debug!("EncodeContext::encode_stability({:?})", def_id);
1165 if let Some(stab) = self.tcx.lookup_stability(def_id) {
1166 record!(self.tables.stability[def_id] <- stab)
1170 fn encode_const_stability(&mut self, def_id: DefId) {
1171 debug!("EncodeContext::encode_const_stability({:?})", def_id);
1172 if let Some(stab) = self.tcx.lookup_const_stability(def_id) {
1173 record!(self.tables.const_stability[def_id] <- stab)
1177 fn encode_deprecation(&mut self, def_id: DefId) {
1178 debug!("EncodeContext::encode_deprecation({:?})", def_id);
1179 if let Some(depr) = self.tcx.lookup_deprecation(def_id) {
1180 record!(self.tables.deprecation[def_id] <- depr);
1184 fn encode_rendered_const_for_body(&mut self, body_id: hir::BodyId) -> Lazy<RenderedConst> {
1185 let hir = self.tcx.hir();
1186 let body = hir.body(body_id);
1187 let rendered = rustc_hir_pretty::to_string(&(&hir as &dyn intravisit::Map<'_>), |s| {
1188 s.print_expr(&body.value)
1190 let rendered_const = &RenderedConst(rendered);
1191 self.lazy(rendered_const)
1194 fn encode_info_for_item(&mut self, def_id: DefId, item: &'tcx hir::Item<'tcx>) {
1197 debug!("EncodeContext::encode_info_for_item({:?})", def_id);
1199 self.encode_ident_span(def_id, item.ident);
1201 record!(self.tables.kind[def_id] <- match item.kind {
1202 hir::ItemKind::Static(_, hir::Mutability::Mut, _) => EntryKind::MutStatic,
1203 hir::ItemKind::Static(_, hir::Mutability::Not, _) => EntryKind::ImmStatic,
1204 hir::ItemKind::Const(_, body_id) => {
1205 let qualifs = self.tcx.at(item.span).mir_const_qualif(def_id);
1208 self.encode_rendered_const_for_body(body_id)
1211 hir::ItemKind::Fn(ref sig, .., body) => {
1213 asyncness: sig.header.asyncness,
1214 constness: sig.header.constness,
1215 param_names: self.encode_fn_param_names_for_body(body),
1218 EntryKind::Fn(self.lazy(data))
1220 hir::ItemKind::Mod(ref m) => {
1221 return self.encode_info_for_mod(item.hir_id, m, &item.attrs, &item.vis);
1223 hir::ItemKind::ForeignMod(_) => EntryKind::ForeignMod,
1224 hir::ItemKind::GlobalAsm(..) => EntryKind::GlobalAsm,
1225 hir::ItemKind::TyAlias(..) => EntryKind::Type,
1226 hir::ItemKind::OpaqueTy(..) => EntryKind::OpaqueTy,
1227 hir::ItemKind::Enum(..) => EntryKind::Enum(self.tcx.adt_def(def_id).repr),
1228 hir::ItemKind::Struct(ref struct_def, _) => {
1229 let adt_def = self.tcx.adt_def(def_id);
1230 let variant = adt_def.non_enum_variant();
1232 // Encode def_ids for each field and method
1233 // for methods, write all the stuff get_trait_method
1235 let ctor = struct_def.ctor_hir_id().map(|ctor_hir_id| {
1236 self.tcx.hir().local_def_id(ctor_hir_id).local_def_index
1239 EntryKind::Struct(self.lazy(VariantData {
1240 ctor_kind: variant.ctor_kind,
1241 discr: variant.discr,
1243 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
1246 hir::ItemKind::Union(..) => {
1247 let adt_def = self.tcx.adt_def(def_id);
1248 let variant = adt_def.non_enum_variant();
1250 EntryKind::Union(self.lazy(VariantData {
1251 ctor_kind: variant.ctor_kind,
1252 discr: variant.discr,
1254 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
1257 hir::ItemKind::Impl { defaultness, .. } => {
1258 let trait_ref = self.tcx.impl_trait_ref(def_id);
1259 let polarity = self.tcx.impl_polarity(def_id);
1260 let parent = if let Some(trait_ref) = trait_ref {
1261 let trait_def = self.tcx.trait_def(trait_ref.def_id);
1262 trait_def.ancestors(self.tcx, def_id).ok()
1263 .and_then(|mut an| an.nth(1).and_then(|node| {
1265 specialization_graph::Node::Impl(parent) => Some(parent),
1273 // if this is an impl of `CoerceUnsized`, create its
1274 // "unsized info", else just store None
1275 let coerce_unsized_info =
1276 trait_ref.and_then(|t| {
1277 if Some(t.def_id) == self.tcx.lang_items().coerce_unsized_trait() {
1278 Some(self.tcx.at(item.span).coerce_unsized_info(def_id))
1284 let data = ImplData {
1287 parent_impl: parent,
1288 coerce_unsized_info,
1291 EntryKind::Impl(self.lazy(data))
1293 hir::ItemKind::Trait(..) => {
1294 let trait_def = self.tcx.trait_def(def_id);
1295 let data = TraitData {
1296 unsafety: trait_def.unsafety,
1297 paren_sugar: trait_def.paren_sugar,
1298 has_auto_impl: self.tcx.trait_is_auto(def_id),
1299 is_marker: trait_def.is_marker,
1300 specialization_kind: trait_def.specialization_kind,
1303 EntryKind::Trait(self.lazy(data))
1305 hir::ItemKind::TraitAlias(..) => EntryKind::TraitAlias,
1306 hir::ItemKind::ExternCrate(_) |
1307 hir::ItemKind::Use(..) => bug!("cannot encode info for item {:?}", item),
1309 record!(self.tables.visibility[def_id] <-
1310 ty::Visibility::from_hir(&item.vis, item.hir_id, tcx));
1311 record!(self.tables.span[def_id] <- item.span);
1312 record!(self.tables.attributes[def_id] <- item.attrs);
1313 // FIXME(eddyb) there should be a nicer way to do this.
1315 hir::ItemKind::ForeignMod(ref fm) => record!(self.tables.children[def_id] <-
1318 .map(|foreign_item| tcx.hir().local_def_id(
1319 foreign_item.hir_id).local_def_index)
1321 hir::ItemKind::Enum(..) => record!(self.tables.children[def_id] <-
1322 self.tcx.adt_def(def_id).variants.iter().map(|v| {
1323 assert!(v.def_id.is_local());
1327 hir::ItemKind::Struct(..) | hir::ItemKind::Union(..) => {
1328 record!(self.tables.children[def_id] <-
1329 self.tcx.adt_def(def_id).non_enum_variant().fields.iter().map(|f| {
1330 assert!(f.did.is_local());
1335 hir::ItemKind::Impl { .. } | hir::ItemKind::Trait(..) => {
1336 let associated_item_def_ids = self.tcx.associated_item_def_ids(def_id);
1337 record!(self.tables.children[def_id] <-
1338 associated_item_def_ids.iter().map(|&def_id| {
1339 assert!(def_id.is_local());
1346 self.encode_stability(def_id);
1347 self.encode_const_stability(def_id);
1348 self.encode_deprecation(def_id);
1350 hir::ItemKind::Static(..)
1351 | hir::ItemKind::Const(..)
1352 | hir::ItemKind::Fn(..)
1353 | hir::ItemKind::TyAlias(..)
1354 | hir::ItemKind::OpaqueTy(..)
1355 | hir::ItemKind::Enum(..)
1356 | hir::ItemKind::Struct(..)
1357 | hir::ItemKind::Union(..)
1358 | hir::ItemKind::Impl { .. } => self.encode_item_type(def_id),
1361 if let hir::ItemKind::Fn(..) = item.kind {
1362 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1364 if let hir::ItemKind::Impl { .. } = item.kind {
1365 if let Some(trait_ref) = self.tcx.impl_trait_ref(def_id) {
1366 record!(self.tables.impl_trait_ref[def_id] <- trait_ref);
1369 self.encode_inherent_implementations(def_id);
1371 hir::ItemKind::Enum(..)
1372 | hir::ItemKind::Struct(..)
1373 | hir::ItemKind::Union(..)
1374 | hir::ItemKind::Fn(..) => self.encode_variances_of(def_id),
1378 hir::ItemKind::Static(..)
1379 | hir::ItemKind::Const(..)
1380 | hir::ItemKind::Fn(..)
1381 | hir::ItemKind::TyAlias(..)
1382 | hir::ItemKind::Enum(..)
1383 | hir::ItemKind::Struct(..)
1384 | hir::ItemKind::Union(..)
1385 | hir::ItemKind::Impl { .. }
1386 | hir::ItemKind::OpaqueTy(..)
1387 | hir::ItemKind::Trait(..)
1388 | hir::ItemKind::TraitAlias(..) => {
1389 self.encode_generics(def_id);
1390 self.encode_explicit_predicates(def_id);
1391 self.encode_inferred_outlives(def_id);
1396 hir::ItemKind::Trait(..) | hir::ItemKind::TraitAlias(..) => {
1397 self.encode_super_predicates(def_id);
1402 // The following part should be kept in sync with `PrefetchVisitor.visit_item`.
1404 let mir = match item.kind {
1405 hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => true,
1406 hir::ItemKind::Fn(ref sig, ..) => {
1407 let generics = tcx.generics_of(def_id);
1408 let needs_inline = (generics.requires_monomorphization(tcx)
1409 || tcx.codegen_fn_attrs(def_id).requests_inline())
1410 && !self.metadata_output_only();
1411 let always_encode_mir = self.tcx.sess.opts.debugging_opts.always_encode_mir;
1412 needs_inline || sig.header.constness == hir::Constness::Const || always_encode_mir
1417 self.encode_optimized_mir(def_id.expect_local());
1418 self.encode_promoted_mir(def_id.expect_local());
1422 /// Serialize the text of exported macros
1423 fn encode_info_for_macro_def(&mut self, macro_def: &hir::MacroDef<'_>) {
1424 let def_id = self.tcx.hir().local_def_id(macro_def.hir_id).to_def_id();
1425 record!(self.tables.kind[def_id] <- EntryKind::MacroDef(self.lazy(macro_def.ast.clone())));
1426 record!(self.tables.visibility[def_id] <- ty::Visibility::Public);
1427 record!(self.tables.span[def_id] <- macro_def.span);
1428 record!(self.tables.attributes[def_id] <- macro_def.attrs);
1429 self.encode_ident_span(def_id, macro_def.ident);
1430 self.encode_stability(def_id);
1431 self.encode_deprecation(def_id);
1434 fn encode_info_for_generic_param(&mut self, def_id: DefId, kind: EntryKind, encode_type: bool) {
1435 record!(self.tables.kind[def_id] <- kind);
1436 record!(self.tables.visibility[def_id] <- ty::Visibility::Public);
1437 record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));
1439 self.encode_item_type(def_id);
1443 fn encode_info_for_closure(&mut self, def_id: LocalDefId) {
1444 debug!("EncodeContext::encode_info_for_closure({:?})", def_id);
1446 // NOTE(eddyb) `tcx.type_of(def_id)` isn't used because it's fully generic,
1447 // including on the signature, which is inferred in `typeck.
1448 let hir_id = self.tcx.hir().as_local_hir_id(def_id);
1449 let ty = self.tcx.typeck(def_id).node_type(hir_id);
1451 record!(self.tables.kind[def_id.to_def_id()] <- match ty.kind {
1452 ty::Generator(..) => {
1453 let data = self.tcx.generator_kind(def_id).unwrap();
1454 EntryKind::Generator(data)
1457 ty::Closure(..) => EntryKind::Closure,
1459 _ => bug!("closure that is neither generator nor closure"),
1461 record!(self.tables.visibility[def_id.to_def_id()] <- ty::Visibility::Public);
1462 record!(self.tables.span[def_id.to_def_id()] <- self.tcx.def_span(def_id));
1463 record!(self.tables.attributes[def_id.to_def_id()] <- &self.tcx.get_attrs(def_id.to_def_id())[..]);
1464 self.encode_item_type(def_id.to_def_id());
1465 if let ty::Closure(def_id, substs) = ty.kind {
1466 record!(self.tables.fn_sig[def_id] <- substs.as_closure().sig());
1468 self.encode_generics(def_id.to_def_id());
1469 self.encode_optimized_mir(def_id);
1470 self.encode_promoted_mir(def_id);
1473 fn encode_info_for_anon_const(&mut self, def_id: LocalDefId) {
1474 debug!("EncodeContext::encode_info_for_anon_const({:?})", def_id);
1475 let id = self.tcx.hir().as_local_hir_id(def_id);
1476 let body_id = self.tcx.hir().body_owned_by(id);
1477 let const_data = self.encode_rendered_const_for_body(body_id);
1478 let qualifs = self.tcx.mir_const_qualif(def_id);
1480 record!(self.tables.kind[def_id.to_def_id()] <- EntryKind::AnonConst(qualifs, const_data));
1481 record!(self.tables.visibility[def_id.to_def_id()] <- ty::Visibility::Public);
1482 record!(self.tables.span[def_id.to_def_id()] <- self.tcx.def_span(def_id));
1483 self.encode_item_type(def_id.to_def_id());
1484 self.encode_generics(def_id.to_def_id());
1485 self.encode_explicit_predicates(def_id.to_def_id());
1486 self.encode_inferred_outlives(def_id.to_def_id());
1487 self.encode_optimized_mir(def_id);
1488 self.encode_promoted_mir(def_id);
1491 fn encode_native_libraries(&mut self) -> Lazy<[NativeLib]> {
1492 let used_libraries = self.tcx.native_libraries(LOCAL_CRATE);
1493 self.lazy(used_libraries.iter().cloned())
1496 fn encode_foreign_modules(&mut self) -> Lazy<[ForeignModule]> {
1497 let foreign_modules = self.tcx.foreign_modules(LOCAL_CRATE);
1498 self.lazy(foreign_modules.iter().cloned())
1501 fn encode_hygiene(&mut self) -> (SyntaxContextTable, ExpnDataTable) {
1502 let mut syntax_contexts: TableBuilder<_, _> = Default::default();
1503 let mut expn_data_table: TableBuilder<_, _> = Default::default();
1505 let _: Result<(), !> = self.hygiene_ctxt.encode(
1506 &mut (&mut *self, &mut syntax_contexts, &mut expn_data_table),
1507 |(this, syntax_contexts, _), index, ctxt_data| {
1508 syntax_contexts.set(index, this.lazy(ctxt_data));
1511 |(this, _, expn_data_table), index, expn_data| {
1512 expn_data_table.set(index, this.lazy(expn_data));
1517 (syntax_contexts.encode(&mut self.opaque), expn_data_table.encode(&mut self.opaque))
1520 fn encode_proc_macros(&mut self) -> Option<Lazy<[DefIndex]>> {
1521 let is_proc_macro = self.tcx.sess.crate_types().contains(&CrateType::ProcMacro);
1524 Some(self.lazy(tcx.hir().krate().proc_macros.iter().map(|p| p.owner.local_def_index)))
1530 fn encode_crate_deps(&mut self) -> Lazy<[CrateDep]> {
1531 let crates = self.tcx.crates();
1533 let mut deps = crates
1536 let dep = CrateDep {
1537 name: self.tcx.original_crate_name(cnum),
1538 hash: self.tcx.crate_hash(cnum),
1539 host_hash: self.tcx.crate_host_hash(cnum),
1540 kind: self.tcx.dep_kind(cnum),
1541 extra_filename: self.tcx.extra_filename(cnum),
1545 .collect::<Vec<_>>();
1547 deps.sort_by_key(|&(cnum, _)| cnum);
1550 // Sanity-check the crate numbers
1551 let mut expected_cnum = 1;
1552 for &(n, _) in &deps {
1553 assert_eq!(n, CrateNum::new(expected_cnum));
1558 // We're just going to write a list of crate 'name-hash-version's, with
1559 // the assumption that they are numbered 1 to n.
1560 // FIXME (#2166): This is not nearly enough to support correct versioning
1561 // but is enough to get transitive crate dependencies working.
1562 self.lazy(deps.iter().map(|&(_, ref dep)| dep))
1565 fn encode_lib_features(&mut self) -> Lazy<[(Symbol, Option<Symbol>)]> {
1567 let lib_features = tcx.lib_features();
1568 self.lazy(lib_features.to_vec())
1571 fn encode_diagnostic_items(&mut self) -> Lazy<[(Symbol, DefIndex)]> {
1573 let diagnostic_items = tcx.diagnostic_items(LOCAL_CRATE);
1574 self.lazy(diagnostic_items.iter().map(|(&name, def_id)| (name, def_id.index)))
1577 fn encode_lang_items(&mut self) -> Lazy<[(DefIndex, usize)]> {
1579 let lang_items = tcx.lang_items();
1580 let lang_items = lang_items.items().iter();
1581 self.lazy(lang_items.enumerate().filter_map(|(i, &opt_def_id)| {
1582 if let Some(def_id) = opt_def_id {
1583 if def_id.is_local() {
1584 return Some((def_id.index, i));
1591 fn encode_lang_items_missing(&mut self) -> Lazy<[lang_items::LangItem]> {
1593 self.lazy(&tcx.lang_items().missing)
1596 /// Encodes an index, mapping each trait to its (local) implementations.
1597 fn encode_impls(&mut self) -> Lazy<[TraitImpls]> {
1598 debug!("EncodeContext::encode_impls()");
1600 let mut visitor = ImplVisitor { tcx, impls: FxHashMap::default() };
1601 tcx.hir().krate().visit_all_item_likes(&mut visitor);
1603 let mut all_impls: Vec<_> = visitor.impls.into_iter().collect();
1605 // Bring everything into deterministic order for hashing
1606 all_impls.sort_by_cached_key(|&(trait_def_id, _)| tcx.def_path_hash(trait_def_id));
1608 let all_impls: Vec<_> = all_impls
1610 .map(|(trait_def_id, mut impls)| {
1611 // Bring everything into deterministic order for hashing
1612 impls.sort_by_cached_key(|&(index, _)| {
1613 tcx.hir().definitions().def_path_hash(LocalDefId { local_def_index: index })
1617 trait_id: (trait_def_id.krate.as_u32(), trait_def_id.index),
1618 impls: self.lazy(&impls),
1623 self.lazy(&all_impls)
1626 // Encodes all symbols exported from this crate into the metadata.
1628 // This pass is seeded off the reachability list calculated in the
1629 // middle::reachable module but filters out items that either don't have a
1630 // symbol associated with them (they weren't translated) or if they're an FFI
1631 // definition (as that's not defined in this crate).
1632 fn encode_exported_symbols(
1634 exported_symbols: &[(ExportedSymbol<'tcx>, SymbolExportLevel)],
1635 ) -> Lazy<[(ExportedSymbol<'tcx>, SymbolExportLevel)]> {
1636 // The metadata symbol name is special. It should not show up in
1637 // downstream crates.
1638 let metadata_symbol_name = SymbolName::new(self.tcx, &metadata_symbol_name(self.tcx));
1643 .filter(|&&(ref exported_symbol, _)| match *exported_symbol {
1644 ExportedSymbol::NoDefId(symbol_name) => symbol_name != metadata_symbol_name,
1651 fn encode_dylib_dependency_formats(&mut self) -> Lazy<[Option<LinkagePreference>]> {
1652 let formats = self.tcx.dependency_formats(LOCAL_CRATE);
1653 for (ty, arr) in formats.iter() {
1654 if *ty != CrateType::Dylib {
1657 return self.lazy(arr.iter().map(|slot| match *slot {
1658 Linkage::NotLinked | Linkage::IncludedFromDylib => None,
1660 Linkage::Dynamic => Some(LinkagePreference::RequireDynamic),
1661 Linkage::Static => Some(LinkagePreference::RequireStatic),
1667 fn encode_info_for_foreign_item(&mut self, def_id: DefId, nitem: &hir::ForeignItem<'_>) {
1670 debug!("EncodeContext::encode_info_for_foreign_item({:?})", def_id);
1672 record!(self.tables.kind[def_id] <- match nitem.kind {
1673 hir::ForeignItemKind::Fn(_, ref names, _) => {
1675 asyncness: hir::IsAsync::NotAsync,
1676 constness: if self.tcx.is_const_fn_raw(def_id) {
1677 hir::Constness::Const
1679 hir::Constness::NotConst
1681 param_names: self.encode_fn_param_names(names),
1683 EntryKind::ForeignFn(self.lazy(data))
1685 hir::ForeignItemKind::Static(_, hir::Mutability::Mut) => EntryKind::ForeignMutStatic,
1686 hir::ForeignItemKind::Static(_, hir::Mutability::Not) => EntryKind::ForeignImmStatic,
1687 hir::ForeignItemKind::Type => EntryKind::ForeignType,
1689 record!(self.tables.visibility[def_id] <-
1690 ty::Visibility::from_hir(&nitem.vis, nitem.hir_id, self.tcx));
1691 record!(self.tables.span[def_id] <- nitem.span);
1692 record!(self.tables.attributes[def_id] <- nitem.attrs);
1693 self.encode_ident_span(def_id, nitem.ident);
1694 self.encode_stability(def_id);
1695 self.encode_const_stability(def_id);
1696 self.encode_deprecation(def_id);
1697 self.encode_item_type(def_id);
1698 if let hir::ForeignItemKind::Fn(..) = nitem.kind {
1699 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1700 self.encode_variances_of(def_id);
1702 self.encode_generics(def_id);
1703 self.encode_explicit_predicates(def_id);
1704 self.encode_inferred_outlives(def_id);
1708 // FIXME(eddyb) make metadata encoding walk over all definitions, instead of HIR.
1709 impl Visitor<'tcx> for EncodeContext<'a, 'tcx> {
1710 type Map = Map<'tcx>;
1712 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1713 NestedVisitorMap::OnlyBodies(self.tcx.hir())
1715 fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
1716 intravisit::walk_expr(self, ex);
1717 self.encode_info_for_expr(ex);
1719 fn visit_anon_const(&mut self, c: &'tcx AnonConst) {
1720 intravisit::walk_anon_const(self, c);
1721 let def_id = self.tcx.hir().local_def_id(c.hir_id);
1722 self.encode_info_for_anon_const(def_id);
1724 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1725 intravisit::walk_item(self, item);
1726 let def_id = self.tcx.hir().local_def_id(item.hir_id);
1728 hir::ItemKind::ExternCrate(_) | hir::ItemKind::Use(..) => {} // ignore these
1729 _ => self.encode_info_for_item(def_id.to_def_id(), item),
1731 self.encode_addl_info_for_item(item);
1733 fn visit_foreign_item(&mut self, ni: &'tcx hir::ForeignItem<'tcx>) {
1734 intravisit::walk_foreign_item(self, ni);
1735 let def_id = self.tcx.hir().local_def_id(ni.hir_id);
1736 self.encode_info_for_foreign_item(def_id.to_def_id(), ni);
1738 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1739 intravisit::walk_generics(self, generics);
1740 self.encode_info_for_generics(generics);
1742 fn visit_macro_def(&mut self, macro_def: &'tcx hir::MacroDef<'tcx>) {
1743 self.encode_info_for_macro_def(macro_def);
1747 impl EncodeContext<'a, 'tcx> {
1748 fn encode_fields(&mut self, adt_def: &ty::AdtDef) {
1749 for (variant_index, variant) in adt_def.variants.iter_enumerated() {
1750 for (field_index, _field) in variant.fields.iter().enumerate() {
1751 self.encode_field(adt_def, variant_index, field_index);
1756 fn encode_info_for_generics(&mut self, generics: &hir::Generics<'tcx>) {
1757 for param in generics.params {
1758 let def_id = self.tcx.hir().local_def_id(param.hir_id);
1760 GenericParamKind::Lifetime { .. } => continue,
1761 GenericParamKind::Type { ref default, .. } => {
1762 self.encode_info_for_generic_param(
1764 EntryKind::TypeParam,
1768 GenericParamKind::Const { .. } => {
1769 self.encode_info_for_generic_param(
1771 EntryKind::ConstParam,
1779 fn encode_info_for_expr(&mut self, expr: &hir::Expr<'_>) {
1780 if let hir::ExprKind::Closure(..) = expr.kind {
1781 let def_id = self.tcx.hir().local_def_id(expr.hir_id);
1782 self.encode_info_for_closure(def_id);
1786 fn encode_ident_span(&mut self, def_id: DefId, ident: Ident) {
1787 record!(self.tables.ident_span[def_id] <- ident.span);
1790 /// In some cases, along with the item itself, we also
1791 /// encode some sub-items. Usually we want some info from the item
1792 /// so it's easier to do that here then to wait until we would encounter
1793 /// normally in the visitor walk.
1794 fn encode_addl_info_for_item(&mut self, item: &hir::Item<'_>) {
1795 let def_id = self.tcx.hir().local_def_id(item.hir_id);
1797 hir::ItemKind::Static(..)
1798 | hir::ItemKind::Const(..)
1799 | hir::ItemKind::Fn(..)
1800 | hir::ItemKind::Mod(..)
1801 | hir::ItemKind::ForeignMod(..)
1802 | hir::ItemKind::GlobalAsm(..)
1803 | hir::ItemKind::ExternCrate(..)
1804 | hir::ItemKind::Use(..)
1805 | hir::ItemKind::TyAlias(..)
1806 | hir::ItemKind::OpaqueTy(..)
1807 | hir::ItemKind::TraitAlias(..) => {
1808 // no sub-item recording needed in these cases
1810 hir::ItemKind::Enum(..) => {
1811 let def = self.tcx.adt_def(def_id.to_def_id());
1812 self.encode_fields(def);
1814 for (i, variant) in def.variants.iter_enumerated() {
1815 self.encode_enum_variant_info(def, i);
1817 if let Some(_ctor_def_id) = variant.ctor_def_id {
1818 self.encode_enum_variant_ctor(def, i);
1822 hir::ItemKind::Struct(ref struct_def, _) => {
1823 let def = self.tcx.adt_def(def_id.to_def_id());
1824 self.encode_fields(def);
1826 // If the struct has a constructor, encode it.
1827 if let Some(ctor_hir_id) = struct_def.ctor_hir_id() {
1828 let ctor_def_id = self.tcx.hir().local_def_id(ctor_hir_id);
1829 self.encode_struct_ctor(def, ctor_def_id.to_def_id());
1832 hir::ItemKind::Union(..) => {
1833 let def = self.tcx.adt_def(def_id.to_def_id());
1834 self.encode_fields(def);
1836 hir::ItemKind::Impl { .. } => {
1837 for &trait_item_def_id in
1838 self.tcx.associated_item_def_ids(def_id.to_def_id()).iter()
1840 self.encode_info_for_impl_item(trait_item_def_id);
1843 hir::ItemKind::Trait(..) => {
1844 for &item_def_id in self.tcx.associated_item_def_ids(def_id.to_def_id()).iter() {
1845 self.encode_info_for_trait_item(item_def_id);
1852 struct ImplVisitor<'tcx> {
1854 impls: FxHashMap<DefId, Vec<(DefIndex, Option<ty::fast_reject::SimplifiedType>)>>,
1857 impl<'tcx, 'v> ItemLikeVisitor<'v> for ImplVisitor<'tcx> {
1858 fn visit_item(&mut self, item: &hir::Item<'_>) {
1859 if let hir::ItemKind::Impl { .. } = item.kind {
1860 let impl_id = self.tcx.hir().local_def_id(item.hir_id);
1861 if let Some(trait_ref) = self.tcx.impl_trait_ref(impl_id.to_def_id()) {
1862 let simplified_self_ty =
1863 ty::fast_reject::simplify_type(self.tcx, trait_ref.self_ty(), false);
1866 .entry(trait_ref.def_id)
1868 .push((impl_id.local_def_index, simplified_self_ty));
1873 fn visit_trait_item(&mut self, _trait_item: &'v hir::TraitItem<'v>) {}
1875 fn visit_impl_item(&mut self, _impl_item: &'v hir::ImplItem<'v>) {
1876 // handled in `visit_item` above
1880 /// Used to prefetch queries which will be needed later by metadata encoding.
1881 /// Only a subset of the queries are actually prefetched to keep this code smaller.
1882 struct PrefetchVisitor<'tcx> {
1884 mir_keys: &'tcx FxHashSet<LocalDefId>,
1887 impl<'tcx> PrefetchVisitor<'tcx> {
1888 fn prefetch_mir(&self, def_id: LocalDefId) {
1889 if self.mir_keys.contains(&def_id) {
1890 self.tcx.ensure().optimized_mir(def_id);
1891 self.tcx.ensure().promoted_mir(def_id);
1896 impl<'tcx, 'v> ParItemLikeVisitor<'v> for PrefetchVisitor<'tcx> {
1897 fn visit_item(&self, item: &hir::Item<'_>) {
1898 // This should be kept in sync with `encode_info_for_item`.
1901 hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => {
1902 self.prefetch_mir(tcx.hir().local_def_id(item.hir_id))
1904 hir::ItemKind::Fn(ref sig, ..) => {
1905 let def_id = tcx.hir().local_def_id(item.hir_id);
1906 let generics = tcx.generics_of(def_id.to_def_id());
1907 let needs_inline = generics.requires_monomorphization(tcx)
1908 || tcx.codegen_fn_attrs(def_id.to_def_id()).requests_inline();
1909 if needs_inline || sig.header.constness == hir::Constness::Const {
1910 self.prefetch_mir(def_id)
1917 fn visit_trait_item(&self, trait_item: &'v hir::TraitItem<'v>) {
1918 // This should be kept in sync with `encode_info_for_trait_item`.
1919 self.prefetch_mir(self.tcx.hir().local_def_id(trait_item.hir_id));
1922 fn visit_impl_item(&self, impl_item: &'v hir::ImplItem<'v>) {
1923 // This should be kept in sync with `encode_info_for_impl_item`.
1925 match impl_item.kind {
1926 hir::ImplItemKind::Const(..) => {
1927 self.prefetch_mir(tcx.hir().local_def_id(impl_item.hir_id))
1929 hir::ImplItemKind::Fn(ref sig, _) => {
1930 let def_id = tcx.hir().local_def_id(impl_item.hir_id);
1931 let generics = tcx.generics_of(def_id.to_def_id());
1932 let needs_inline = generics.requires_monomorphization(tcx)
1933 || tcx.codegen_fn_attrs(def_id.to_def_id()).requests_inline();
1934 let is_const_fn = sig.header.constness == hir::Constness::Const;
1935 if needs_inline || is_const_fn {
1936 self.prefetch_mir(def_id)
1939 hir::ImplItemKind::TyAlias(..) => (),
1944 // NOTE(eddyb) The following comment was preserved for posterity, even
1945 // though it's no longer relevant as EBML (which uses nested & tagged
1946 // "documents") was replaced with a scheme that can't go out of bounds.
1948 // And here we run into yet another obscure archive bug: in which metadata
1949 // loaded from archives may have trailing garbage bytes. Awhile back one of
1950 // our tests was failing sporadically on the macOS 64-bit builders (both nopt
1951 // and opt) by having ebml generate an out-of-bounds panic when looking at
1954 // Upon investigation it turned out that the metadata file inside of an rlib
1955 // (and ar archive) was being corrupted. Some compilations would generate a
1956 // metadata file which would end in a few extra bytes, while other
1957 // compilations would not have these extra bytes appended to the end. These
1958 // extra bytes were interpreted by ebml as an extra tag, so they ended up
1959 // being interpreted causing the out-of-bounds.
1961 // The root cause of why these extra bytes were appearing was never
1962 // discovered, and in the meantime the solution we're employing is to insert
1963 // the length of the metadata to the start of the metadata. Later on this
1964 // will allow us to slice the metadata to the precise length that we just
1965 // generated regardless of trailing bytes that end up in it.
1967 pub(super) fn encode_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
1968 // Since encoding metadata is not in a query, and nothing is cached,
1969 // there's no need to do dep-graph tracking for any of it.
1970 tcx.dep_graph.assert_ignored();
1973 || encode_metadata_impl(tcx),
1975 if tcx.sess.threads() == 1 {
1978 // Prefetch some queries used by metadata encoding.
1979 // This is not necessary for correctness, but is only done for performance reasons.
1980 // It can be removed if it turns out to cause trouble or be detrimental to performance.
1983 if !tcx.sess.opts.output_types.should_codegen() {
1984 // We won't emit MIR, so don't prefetch it.
1987 tcx.hir().krate().par_visit_all_item_likes(&PrefetchVisitor {
1989 mir_keys: tcx.mir_keys(LOCAL_CRATE),
1992 || tcx.exported_symbols(LOCAL_CRATE),
1999 fn encode_metadata_impl(tcx: TyCtxt<'_>) -> EncodedMetadata {
2000 let mut encoder = opaque::Encoder::new(vec![]);
2001 encoder.emit_raw_bytes(METADATA_HEADER);
2003 // Will be filled with the root position after encoding everything.
2004 encoder.emit_raw_bytes(&[0, 0, 0, 0]);
2006 let source_map_files = tcx.sess.source_map().files();
2007 let hygiene_ctxt = HygieneEncodeContext::default();
2009 let mut ecx = EncodeContext {
2012 tables: Default::default(),
2013 lazy_state: LazyState::NoNode,
2014 type_shorthands: Default::default(),
2015 predicate_shorthands: Default::default(),
2016 source_file_cache: (source_map_files[0].clone(), 0),
2017 interpret_allocs: Default::default(),
2018 interpret_allocs_inverse: Default::default(),
2019 required_source_files: Some(GrowableBitSet::with_capacity(source_map_files.len())),
2020 is_proc_macro: tcx.sess.crate_types().contains(&CrateType::ProcMacro),
2021 hygiene_ctxt: &hygiene_ctxt,
2023 drop(source_map_files);
2025 // Encode the rustc version string in a predictable location.
2026 rustc_version().encode(&mut ecx).unwrap();
2028 // Encode all the entries and extra information in the crate,
2029 // culminating in the `CrateRoot` which points to all of it.
2030 let root = ecx.encode_crate_root();
2032 let mut result = ecx.opaque.into_inner();
2034 // Encode the root position.
2035 let header = METADATA_HEADER.len();
2036 let pos = root.position.get();
2037 result[header + 0] = (pos >> 24) as u8;
2038 result[header + 1] = (pos >> 16) as u8;
2039 result[header + 2] = (pos >> 8) as u8;
2040 result[header + 3] = (pos >> 0) as u8;
2042 EncodedMetadata { raw_data: result }