1 // Decoding metadata from a single crate's metadata
3 use crate::cstore::{self, CrateMetadata, MetadataBlob, NativeLibrary, ForeignModule};
6 use rustc_data_structures::sync::{Lrc, ReadGuard};
7 use rustc::hir::map::{DefKey, DefPath, DefPathData, DefPathHash, Definitions};
9 use rustc::middle::cstore::LinkagePreference;
10 use rustc::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
11 use rustc::hir::def::{self, Res, DefKind, CtorOf, CtorKind};
12 use rustc::hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
13 use rustc::hir::map::definitions::DefPathTable;
14 use rustc_data_structures::fingerprint::Fingerprint;
15 use rustc::middle::lang_items;
16 use rustc::mir::{self, interpret};
17 use rustc::mir::interpret::AllocDecodingSession;
18 use rustc::session::Session;
19 use rustc::ty::{self, Ty, TyCtxt};
20 use rustc::ty::codec::TyDecoder;
22 use rustc::util::captures::Captures;
28 use rustc_serialize::{Decodable, Decoder, SpecializedDecoder, opaque};
30 use syntax::ast::{self, Ident};
31 use syntax::source_map;
32 use syntax::symbol::{Symbol, sym};
33 use syntax::ext::base::{MacroKind, SyntaxExtension};
34 use syntax::ext::hygiene::Mark;
35 use syntax_pos::{self, Span, BytePos, Pos, DUMMY_SP, NO_EXPANSION};
38 pub struct DecodeContext<'a, 'tcx: 'a> {
39 opaque: opaque::Decoder<'a>,
40 cdata: Option<&'a CrateMetadata>,
41 sess: Option<&'a Session>,
42 tcx: Option<TyCtxt<'tcx, 'tcx>>,
44 // Cache the last used source_file for translating spans as an optimization.
45 last_source_file_index: usize,
47 lazy_state: LazyState,
49 // Used for decoding interpret::AllocIds in a cached & thread-safe manner.
50 alloc_decoding_session: Option<AllocDecodingSession<'a>>,
53 /// Abstract over the various ways one can create metadata decoders.
54 pub trait Metadata<'a, 'tcx>: Copy {
55 fn raw_bytes(self) -> &'a [u8];
56 fn cdata(self) -> Option<&'a CrateMetadata> { None }
57 fn sess(self) -> Option<&'a Session> { None }
58 fn tcx(self) -> Option<TyCtxt<'tcx, 'tcx>> {
62 fn decoder(self, pos: usize) -> DecodeContext<'a, 'tcx> {
65 opaque: opaque::Decoder::new(self.raw_bytes(), pos),
67 sess: self.sess().or(tcx.map(|tcx| tcx.sess)),
69 last_source_file_index: 0,
70 lazy_state: LazyState::NoNode,
71 alloc_decoding_session: self.cdata().map(|cdata| {
72 cdata.alloc_decoding_state.new_decoding_session()
78 impl<'a, 'tcx> Metadata<'a, 'tcx> for &'a MetadataBlob {
79 fn raw_bytes(self) -> &'a [u8] {
85 impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a MetadataBlob, &'a Session) {
86 fn raw_bytes(self) -> &'a [u8] {
91 fn sess(self) -> Option<&'a Session> {
98 impl<'a, 'tcx> Metadata<'a, 'tcx> for &'a CrateMetadata {
99 fn raw_bytes(self) -> &'a [u8] {
100 self.blob.raw_bytes()
102 fn cdata(self) -> Option<&'a CrateMetadata> {
107 impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a CrateMetadata, &'a Session) {
108 fn raw_bytes(self) -> &'a [u8] {
111 fn cdata(self) -> Option<&'a CrateMetadata> {
114 fn sess(self) -> Option<&'a Session> {
119 impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a CrateMetadata, TyCtxt<'tcx, 'tcx>) {
120 fn raw_bytes(self) -> &'a [u8] {
123 fn cdata(self) -> Option<&'a CrateMetadata> {
126 fn tcx(self) -> Option<TyCtxt<'tcx, 'tcx>> {
131 impl<'a, 'tcx: 'a, T: Decodable> Lazy<T> {
132 pub fn decode<M: Metadata<'a, 'tcx>>(self, meta: M) -> T {
133 let mut dcx = meta.decoder(self.position);
134 dcx.lazy_state = LazyState::NodeStart(self.position);
135 T::decode(&mut dcx).unwrap()
139 impl<'a, 'tcx: 'a, T: Decodable> LazySeq<T> {
140 pub fn decode<M: Metadata<'a, 'tcx>>(
143 ) -> impl Iterator<Item = T> + Captures<'tcx> + 'a {
144 let mut dcx = meta.decoder(self.position);
145 dcx.lazy_state = LazyState::NodeStart(self.position);
146 (0..self.len).map(move |_| T::decode(&mut dcx).unwrap())
150 impl<'a, 'tcx> DecodeContext<'a, 'tcx> {
151 pub fn tcx(&self) -> TyCtxt<'tcx, 'tcx> {
152 self.tcx.expect("missing TyCtxt in DecodeContext")
155 pub fn cdata(&self) -> &'a CrateMetadata {
156 self.cdata.expect("missing CrateMetadata in DecodeContext")
159 fn read_lazy_distance(&mut self, min_size: usize) -> Result<usize, <Self as Decoder>::Error> {
160 let distance = self.read_usize()?;
161 let position = match self.lazy_state {
162 LazyState::NoNode => bug!("read_lazy_distance: outside of a metadata node"),
163 LazyState::NodeStart(start) => {
164 assert!(distance + min_size <= start);
165 start - distance - min_size
167 LazyState::Previous(last_min_end) => last_min_end + distance,
169 self.lazy_state = LazyState::Previous(position + min_size);
174 impl<'a, 'tcx> TyDecoder<'tcx> for DecodeContext<'a, 'tcx> {
176 fn tcx(&self) -> TyCtxt<'tcx, 'tcx> {
177 self.tcx.expect("missing TyCtxt in DecodeContext")
181 fn peek_byte(&self) -> u8 {
182 self.opaque.data[self.opaque.position()]
186 fn position(&self) -> usize {
187 self.opaque.position()
190 fn cached_ty_for_shorthand<F>(&mut self,
193 -> Result<Ty<'tcx>, Self::Error>
194 where F: FnOnce(&mut Self) -> Result<Ty<'tcx>, Self::Error>
196 let tcx = self.tcx();
198 let key = ty::CReaderCacheKey {
199 cnum: self.cdata().cnum,
203 if let Some(&ty) = tcx.rcache.borrow().get(&key) {
207 let ty = or_insert_with(self)?;
208 tcx.rcache.borrow_mut().insert(key, ty);
212 fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
213 where F: FnOnce(&mut Self) -> R
215 let new_opaque = opaque::Decoder::new(self.opaque.data, pos);
216 let old_opaque = mem::replace(&mut self.opaque, new_opaque);
217 let old_state = mem::replace(&mut self.lazy_state, LazyState::NoNode);
219 self.opaque = old_opaque;
220 self.lazy_state = old_state;
224 fn map_encoded_cnum_to_current(&self, cnum: CrateNum) -> CrateNum {
225 if cnum == LOCAL_CRATE {
228 self.cdata().cnum_map[cnum]
233 impl<'a, 'tcx, T> SpecializedDecoder<Lazy<T>> for DecodeContext<'a, 'tcx> {
234 fn specialized_decode(&mut self) -> Result<Lazy<T>, Self::Error> {
235 Ok(Lazy::with_position(self.read_lazy_distance(Lazy::<T>::min_size())?))
239 impl<'a, 'tcx, T> SpecializedDecoder<LazySeq<T>> for DecodeContext<'a, 'tcx> {
240 fn specialized_decode(&mut self) -> Result<LazySeq<T>, Self::Error> {
241 let len = self.read_usize()?;
242 let position = if len == 0 {
245 self.read_lazy_distance(LazySeq::<T>::min_size(len))?
247 Ok(LazySeq::with_position_and_length(position, len))
252 impl<'a, 'tcx> SpecializedDecoder<DefId> for DecodeContext<'a, 'tcx> {
254 fn specialized_decode(&mut self) -> Result<DefId, Self::Error> {
255 let krate = CrateNum::decode(self)?;
256 let index = DefIndex::decode(self)?;
265 impl<'a, 'tcx> SpecializedDecoder<DefIndex> for DecodeContext<'a, 'tcx> {
267 fn specialized_decode(&mut self) -> Result<DefIndex, Self::Error> {
268 Ok(DefIndex::from_u32(self.read_u32()?))
272 impl<'a, 'tcx> SpecializedDecoder<LocalDefId> for DecodeContext<'a, 'tcx> {
274 fn specialized_decode(&mut self) -> Result<LocalDefId, Self::Error> {
275 self.specialized_decode().map(|i| LocalDefId::from_def_id(i))
279 impl<'a, 'tcx> SpecializedDecoder<interpret::AllocId> for DecodeContext<'a, 'tcx> {
280 fn specialized_decode(&mut self) -> Result<interpret::AllocId, Self::Error> {
281 if let Some(alloc_decoding_session) = self.alloc_decoding_session {
282 alloc_decoding_session.decode_alloc_id(self)
284 bug!("Attempting to decode interpret::AllocId without CrateMetadata")
289 impl<'a, 'tcx> SpecializedDecoder<Span> for DecodeContext<'a, 'tcx> {
290 fn specialized_decode(&mut self) -> Result<Span, Self::Error> {
291 let tag = u8::decode(self)?;
293 if tag == TAG_INVALID_SPAN {
297 debug_assert_eq!(tag, TAG_VALID_SPAN);
299 let lo = BytePos::decode(self)?;
300 let len = BytePos::decode(self)?;
303 let sess = if let Some(sess) = self.sess {
306 bug!("Cannot decode Span without Session.")
309 let imported_source_files = self.cdata().imported_source_files(&sess.source_map());
311 // Optimize for the case that most spans within a translated item
312 // originate from the same source_file.
313 let last_source_file = &imported_source_files[self.last_source_file_index];
315 if lo >= last_source_file.original_start_pos &&
316 lo <= last_source_file.original_end_pos {
320 let mut b = imported_source_files.len();
324 if imported_source_files[m].original_start_pos > lo {
331 self.last_source_file_index = a;
332 &imported_source_files[a]
336 // Make sure our binary search above is correct.
337 debug_assert!(lo >= source_file.original_start_pos &&
338 lo <= source_file.original_end_pos);
340 // Make sure we correctly filtered out invalid spans during encoding
341 debug_assert!(hi >= source_file.original_start_pos &&
342 hi <= source_file.original_end_pos);
344 let lo = (lo + source_file.translated_source_file.start_pos)
345 - source_file.original_start_pos;
346 let hi = (hi + source_file.translated_source_file.start_pos)
347 - source_file.original_start_pos;
349 Ok(Span::new(lo, hi, NO_EXPANSION))
353 impl<'a, 'tcx> SpecializedDecoder<Fingerprint> for DecodeContext<'a, 'tcx> {
354 fn specialized_decode(&mut self) -> Result<Fingerprint, Self::Error> {
355 Fingerprint::decode_opaque(&mut self.opaque)
359 impl<'a, 'tcx, T: Decodable> SpecializedDecoder<mir::ClearCrossCrate<T>>
360 for DecodeContext<'a, 'tcx> {
362 fn specialized_decode(&mut self) -> Result<mir::ClearCrossCrate<T>, Self::Error> {
363 Ok(mir::ClearCrossCrate::Clear)
367 implement_ty_decoder!( DecodeContext<'a, 'tcx> );
369 impl<'tcx> MetadataBlob {
370 pub fn is_compatible(&self) -> bool {
371 self.raw_bytes().starts_with(METADATA_HEADER)
374 pub fn get_rustc_version(&self) -> String {
375 Lazy::with_position(METADATA_HEADER.len() + 4).decode(self)
378 pub fn get_root(&self) -> CrateRoot<'tcx> {
379 let slice = self.raw_bytes();
380 let offset = METADATA_HEADER.len();
381 let pos = (((slice[offset + 0] as u32) << 24) | ((slice[offset + 1] as u32) << 16) |
382 ((slice[offset + 2] as u32) << 8) |
383 ((slice[offset + 3] as u32) << 0)) as usize;
384 Lazy::with_position(pos).decode(self)
387 pub fn list_crate_metadata(&self,
388 out: &mut dyn io::Write) -> io::Result<()> {
389 write!(out, "=External Dependencies=\n")?;
390 let root = self.get_root();
391 for (i, dep) in root.crate_deps
394 write!(out, "{} {}{}\n", i + 1, dep.name, dep.extra_filename)?;
401 impl<'tcx> EntryKind<'tcx> {
402 fn def_kind(&self) -> Option<DefKind> {
404 EntryKind::Const(..) => DefKind::Const,
405 EntryKind::AssocConst(..) => DefKind::AssocConst,
406 EntryKind::ImmStatic |
407 EntryKind::MutStatic |
408 EntryKind::ForeignImmStatic |
409 EntryKind::ForeignMutStatic => DefKind::Static,
410 EntryKind::Struct(_, _) => DefKind::Struct,
411 EntryKind::Union(_, _) => DefKind::Union,
413 EntryKind::ForeignFn(_) => DefKind::Fn,
414 EntryKind::Method(_) => DefKind::Method,
415 EntryKind::Type => DefKind::TyAlias,
416 EntryKind::TypeParam => DefKind::TyParam,
417 EntryKind::ConstParam => DefKind::ConstParam,
418 EntryKind::Existential => DefKind::Existential,
419 EntryKind::AssocType(_) => DefKind::AssocTy,
420 EntryKind::AssocExistential(_) => DefKind::AssocExistential,
421 EntryKind::Mod(_) => DefKind::Mod,
422 EntryKind::Variant(_) => DefKind::Variant,
423 EntryKind::Trait(_) => DefKind::Trait,
424 EntryKind::TraitAlias(_) => DefKind::TraitAlias,
425 EntryKind::Enum(..) => DefKind::Enum,
426 EntryKind::MacroDef(_) => DefKind::Macro(MacroKind::Bang),
427 EntryKind::ForeignType => DefKind::ForeignTy,
429 EntryKind::ForeignMod |
430 EntryKind::GlobalAsm |
433 EntryKind::Generator(_) |
434 EntryKind::Closure(_) => return None,
439 /// Creates the "fake" DefPathTable for a given proc macro crate.
441 /// The DefPathTable is as follows:
443 /// CRATE_ROOT (DefIndex 0:0)
444 /// |- GlobalMetaDataKind data (DefIndex 1:0 .. DefIndex 1:N)
445 /// |- proc macro #0 (DefIndex 1:N)
446 /// |- proc macro #1 (DefIndex 1:N+1)
448 crate fn proc_macro_def_path_table(crate_root: &CrateRoot<'_>,
449 proc_macros: &[(ast::Name, Lrc<SyntaxExtension>)])
452 let mut definitions = Definitions::default();
454 let name = crate_root.name.as_str();
455 let disambiguator = crate_root.disambiguator;
456 debug!("creating proc macro def path table for {:?}/{:?}", name, disambiguator);
457 let crate_root = definitions.create_root_def(&name, disambiguator);
458 for (index, (name, _)) in proc_macros.iter().enumerate() {
459 let def_index = definitions.create_def_with_parent(
462 DefPathData::MacroNs(name.as_interned_str()),
465 debug!("definition for {:?} is {:?}", name, def_index);
466 assert_eq!(def_index, DefIndex::from_proc_macro_index(index));
469 definitions.def_path_table().clone()
472 impl<'a, 'tcx> CrateMetadata {
473 fn is_proc_macro(&self, id: DefIndex) -> bool {
474 self.proc_macros.is_some() && id != CRATE_DEF_INDEX
477 fn maybe_entry(&self, item_id: DefIndex) -> Option<Lazy<Entry<'tcx>>> {
478 assert!(!self.is_proc_macro(item_id));
479 self.root.entries_index.lookup(self.blob.raw_bytes(), item_id)
482 fn entry(&self, item_id: DefIndex) -> Entry<'tcx> {
483 match self.maybe_entry(item_id) {
485 bug!("entry: id not found: {:?} in crate {:?} with number {}",
490 Some(d) => d.decode(self),
494 fn local_def_id(&self, index: DefIndex) -> DefId {
501 pub fn item_name(&self, item_index: DefIndex) -> Symbol {
502 self.def_key(item_index)
506 .expect("no name in item_name")
510 pub fn def_kind(&self, index: DefIndex) -> Option<DefKind> {
511 if !self.is_proc_macro(index) {
512 self.entry(index).kind.def_kind()
514 let kind = self.proc_macros.as_ref().unwrap()[index.to_proc_macro_index()].1.kind();
515 Some(DefKind::Macro(kind))
519 pub fn get_span(&self, index: DefIndex, sess: &Session) -> Span {
520 match self.is_proc_macro(index) {
522 false => self.entry(index).span.decode((self, sess)),
526 pub fn get_trait_def(&self, item_id: DefIndex, sess: &Session) -> ty::TraitDef {
527 match self.entry(item_id).kind {
528 EntryKind::Trait(data) => {
529 let data = data.decode((self, sess));
530 ty::TraitDef::new(self.local_def_id(item_id),
535 self.def_path_table.def_path_hash(item_id))
537 EntryKind::TraitAlias(_) => {
538 ty::TraitDef::new(self.local_def_id(item_id),
539 hir::Unsafety::Normal,
543 self.def_path_table.def_path_hash(item_id))
545 _ => bug!("def-index does not refer to trait or trait alias"),
551 tcx: TyCtxt<'tcx, 'tcx>,
555 adt_kind: ty::AdtKind,
556 ) -> ty::VariantDef {
557 let data = match item.kind {
558 EntryKind::Variant(data) |
559 EntryKind::Struct(data, _) |
560 EntryKind::Union(data, _) => data.decode(self),
564 let variant_did = if adt_kind == ty::AdtKind::Enum {
565 Some(self.local_def_id(index))
569 let ctor_did = data.ctor.map(|index| self.local_def_id(index));
573 Ident::with_empty_ctxt(self.item_name(index)),
577 item.children.decode(self).map(|index| {
578 let f = self.entry(index);
580 did: self.local_def_id(index),
581 ident: Ident::with_empty_ctxt(self.item_name(index)),
582 vis: f.visibility.decode(self)
592 pub fn get_adt_def(&self, item_id: DefIndex, tcx: TyCtxt<'tcx, 'tcx>) -> &'tcx ty::AdtDef {
593 let item = self.entry(item_id);
594 let did = self.local_def_id(item_id);
596 let (kind, repr) = match item.kind {
597 EntryKind::Enum(repr) => (ty::AdtKind::Enum, repr),
598 EntryKind::Struct(_, repr) => (ty::AdtKind::Struct, repr),
599 EntryKind::Union(_, repr) => (ty::AdtKind::Union, repr),
600 _ => bug!("get_adt_def called on a non-ADT {:?}", did),
603 let variants = if let ty::AdtKind::Enum = kind {
607 self.get_variant(tcx, &self.entry(index), index, did, kind)
611 std::iter::once(self.get_variant(tcx, &item, item_id, did, kind)).collect()
614 tcx.alloc_adt_def(did, kind, variants, repr)
617 pub fn get_predicates(
620 tcx: TyCtxt<'tcx, 'tcx>,
621 ) -> ty::GenericPredicates<'tcx> {
622 self.entry(item_id).predicates.unwrap().decode((self, tcx))
625 pub fn get_predicates_defined_on(
628 tcx: TyCtxt<'tcx, 'tcx>,
629 ) -> ty::GenericPredicates<'tcx> {
630 self.entry(item_id).predicates_defined_on.unwrap().decode((self, tcx))
633 pub fn get_super_predicates(
636 tcx: TyCtxt<'tcx, 'tcx>,
637 ) -> ty::GenericPredicates<'tcx> {
638 let super_predicates = match self.entry(item_id).kind {
639 EntryKind::Trait(data) => data.decode(self).super_predicates,
640 EntryKind::TraitAlias(data) => data.decode(self).super_predicates,
641 _ => bug!("def-index does not refer to trait or trait alias"),
644 super_predicates.decode((self, tcx))
647 pub fn get_generics(&self,
651 self.entry(item_id).generics.unwrap().decode((self, sess))
654 pub fn get_type(&self, id: DefIndex, tcx: TyCtxt<'tcx, 'tcx>) -> Ty<'tcx> {
655 self.entry(id).ty.unwrap().decode((self, tcx))
658 pub fn get_stability(&self, id: DefIndex) -> Option<attr::Stability> {
659 match self.is_proc_macro(id) {
660 true => self.root.proc_macro_stability.clone(),
661 false => self.entry(id).stability.map(|stab| stab.decode(self)),
665 pub fn get_deprecation(&self, id: DefIndex) -> Option<attr::Deprecation> {
666 match self.is_proc_macro(id) {
668 false => self.entry(id).deprecation.map(|depr| depr.decode(self)),
672 pub fn get_visibility(&self, id: DefIndex) -> ty::Visibility {
673 match self.is_proc_macro(id) {
674 true => ty::Visibility::Public,
675 false => self.entry(id).visibility.decode(self),
679 fn get_impl_data(&self, id: DefIndex) -> ImplData<'tcx> {
680 match self.entry(id).kind {
681 EntryKind::Impl(data) => data.decode(self),
686 pub fn get_parent_impl(&self, id: DefIndex) -> Option<DefId> {
687 self.get_impl_data(id).parent_impl
690 pub fn get_impl_polarity(&self, id: DefIndex) -> hir::ImplPolarity {
691 self.get_impl_data(id).polarity
694 pub fn get_impl_defaultness(&self, id: DefIndex) -> hir::Defaultness {
695 self.get_impl_data(id).defaultness
698 pub fn get_coerce_unsized_info(&self,
700 -> Option<ty::adjustment::CoerceUnsizedInfo> {
701 self.get_impl_data(id).coerce_unsized_info
704 pub fn get_impl_trait(
707 tcx: TyCtxt<'tcx, 'tcx>,
708 ) -> Option<ty::TraitRef<'tcx>> {
709 self.get_impl_data(id).trait_ref.map(|tr| tr.decode((self, tcx)))
712 /// Iterates over all the stability attributes in the given crate.
713 pub fn get_lib_features(
715 tcx: TyCtxt<'tcx, '_>,
716 ) -> &'tcx [(ast::Name, Option<ast::Name>)] {
717 // FIXME: For a proc macro crate, not sure whether we should return the "host"
718 // features or an empty Vec. Both don't cause ICEs.
719 tcx.arena.alloc_from_iter(self.root
724 /// Iterates over the language items in the given crate.
725 pub fn get_lang_items(&self, tcx: TyCtxt<'tcx, '_>) -> &'tcx [(DefId, usize)] {
726 if self.proc_macros.is_some() {
727 // Proc macro crates do not export any lang-items to the target.
730 tcx.arena.alloc_from_iter(self.root
733 .map(|(def_index, index)| (self.local_def_id(def_index), index)))
737 /// Iterates over each child of the given item.
738 pub fn each_child_of_item<F>(&self, id: DefIndex, mut callback: F, sess: &Session)
739 where F: FnMut(def::Export<hir::HirId>)
741 if let Some(ref proc_macros) = self.proc_macros {
742 /* If we are loading as a proc macro, we want to return the view of this crate
743 * as a proc macro crate, not as a Rust crate. See `proc_macro_def_path_table`
744 * for the DefPathTable we are corresponding to.
746 if id == CRATE_DEF_INDEX {
747 for (id, &(name, ref ext)) in proc_macros.iter().enumerate() {
749 DefKind::Macro(ext.kind()),
750 self.local_def_id(DefIndex::from_proc_macro_index(id)),
752 let ident = Ident::with_empty_ctxt(name);
753 callback(def::Export {
756 vis: ty::Visibility::Public,
765 let item = match self.maybe_entry(id) {
767 Some(item) => item.decode((self, sess)),
770 // Iterate over all children.
771 let macros_only = self.dep_kind.lock().macros_only();
772 for child_index in item.children.decode((self, sess)) {
778 if let Some(child) = self.maybe_entry(child_index) {
779 let child = child.decode((self, sess));
781 EntryKind::MacroDef(..) => {}
782 _ if macros_only => continue,
786 // Hand off the item to the callback.
788 // FIXME(eddyb) Don't encode these in children.
789 EntryKind::ForeignMod => {
790 for child_index in child.children.decode((self, sess)) {
791 if let Some(kind) = self.def_kind(child_index) {
792 callback(def::Export {
793 res: Res::Def(kind, self.local_def_id(child_index)),
794 ident: Ident::with_empty_ctxt(self.item_name(child_index)),
795 vis: self.get_visibility(child_index),
796 span: self.entry(child_index).span.decode((self, sess)),
802 EntryKind::Impl(_) => continue,
807 let def_key = self.def_key(child_index);
808 let span = child.span.decode((self, sess));
809 if let (Some(kind), Some(name)) =
810 (self.def_kind(child_index), def_key.disambiguated_data.data.get_opt_name()) {
811 let ident = Ident::from_interned_str(name);
812 let vis = self.get_visibility(child_index);
813 let def_id = self.local_def_id(child_index);
814 let res = Res::Def(kind, def_id);
815 callback(def::Export { res, ident, vis, span });
816 // For non-re-export structs and variants add their constructors to children.
817 // Re-export lists automatically contain constructors when necessary.
820 if let Some(ctor_def_id) = self.get_ctor_def_id(child_index) {
821 let ctor_kind = self.get_ctor_kind(child_index);
822 let ctor_res = Res::Def(
823 DefKind::Ctor(CtorOf::Struct, ctor_kind),
826 let vis = self.get_visibility(ctor_def_id.index);
827 callback(def::Export { res: ctor_res, vis, ident, span });
830 DefKind::Variant => {
831 // Braced variants, unlike structs, generate unusable names in
832 // value namespace, they are reserved for possible future use.
833 // It's ok to use the variant's id as a ctor id since an
834 // error will be reported on any use of such resolution anyway.
835 let ctor_def_id = self.get_ctor_def_id(child_index).unwrap_or(def_id);
836 let ctor_kind = self.get_ctor_kind(child_index);
837 let ctor_res = Res::Def(
838 DefKind::Ctor(CtorOf::Variant, ctor_kind),
841 let mut vis = self.get_visibility(ctor_def_id.index);
842 if ctor_def_id == def_id && vis == ty::Visibility::Public {
843 // For non-exhaustive variants lower the constructor visibility to
844 // within the crate. We only need this for fictive constructors,
845 // for other constructors correct visibilities
846 // were already encoded in metadata.
847 let attrs = self.get_item_attrs(def_id.index, sess);
848 if attr::contains_name(&attrs, sym::non_exhaustive) {
849 let crate_def_id = self.local_def_id(CRATE_DEF_INDEX);
850 vis = ty::Visibility::Restricted(crate_def_id);
853 callback(def::Export { res: ctor_res, ident, vis, span });
861 if let EntryKind::Mod(data) = item.kind {
862 for exp in data.decode((self, sess)).reexports.decode((self, sess)) {
864 Res::Def(DefKind::Macro(..), _) => {}
865 _ if macros_only => continue,
873 pub fn const_is_rvalue_promotable_to_static(&self, id: DefIndex) -> bool {
874 match self.entry(id).kind {
875 EntryKind::AssocConst(_, data, _) |
876 EntryKind::Const(data, _) => data.ast_promotable,
881 pub fn is_item_mir_available(&self, id: DefIndex) -> bool {
882 !self.is_proc_macro(id) &&
883 self.maybe_entry(id).and_then(|item| item.decode(self).mir).is_some()
886 pub fn maybe_get_optimized_mir(
888 tcx: TyCtxt<'tcx, 'tcx>,
890 ) -> Option<Body<'tcx>> {
891 match self.is_proc_macro(id) {
893 false => self.entry(id).mir.map(|mir| mir.decode((self, tcx))),
897 pub fn mir_const_qualif(&self, id: DefIndex) -> u8 {
898 match self.entry(id).kind {
899 EntryKind::Const(qualif, _) |
900 EntryKind::AssocConst(AssocContainer::ImplDefault, qualif, _) |
901 EntryKind::AssocConst(AssocContainer::ImplFinal, qualif, _) => {
908 pub fn get_associated_item(&self, id: DefIndex) -> ty::AssocItem {
909 let item = self.entry(id);
910 let def_key = self.def_key(id);
911 let parent = self.local_def_id(def_key.parent.unwrap());
912 let name = def_key.disambiguated_data.data.get_opt_name().unwrap();
914 let (kind, container, has_self) = match item.kind {
915 EntryKind::AssocConst(container, _, _) => {
916 (ty::AssocKind::Const, container, false)
918 EntryKind::Method(data) => {
919 let data = data.decode(self);
920 (ty::AssocKind::Method, data.container, data.has_self)
922 EntryKind::AssocType(container) => {
923 (ty::AssocKind::Type, container, false)
925 EntryKind::AssocExistential(container) => {
926 (ty::AssocKind::Existential, container, false)
928 _ => bug!("cannot get associated-item of `{:?}`", def_key)
932 ident: Ident::from_interned_str(name),
934 vis: item.visibility.decode(self),
935 defaultness: container.defaultness(),
936 def_id: self.local_def_id(id),
937 container: container.with_def_id(parent),
938 method_has_self_argument: has_self
942 pub fn get_item_variances(&self, id: DefIndex) -> Vec<ty::Variance> {
943 self.entry(id).variances.decode(self).collect()
946 pub fn get_ctor_kind(&self, node_id: DefIndex) -> CtorKind {
947 match self.entry(node_id).kind {
948 EntryKind::Struct(data, _) |
949 EntryKind::Union(data, _) |
950 EntryKind::Variant(data) => data.decode(self).ctor_kind,
951 _ => CtorKind::Fictive,
955 pub fn get_ctor_def_id(&self, node_id: DefIndex) -> Option<DefId> {
956 match self.entry(node_id).kind {
957 EntryKind::Struct(data, _) => {
958 data.decode(self).ctor.map(|index| self.local_def_id(index))
960 EntryKind::Variant(data) => {
961 data.decode(self).ctor.map(|index| self.local_def_id(index))
967 pub fn get_item_attrs(&self, node_id: DefIndex, sess: &Session) -> Lrc<[ast::Attribute]> {
968 if self.is_proc_macro(node_id) {
972 // The attributes for a tuple struct/variant are attached to the definition, not the ctor;
973 // we assume that someone passing in a tuple struct ctor is actually wanting to
974 // look at the definition
975 let def_key = self.def_key(node_id);
976 let item_id = if def_key.disambiguated_data.data == DefPathData::Ctor {
977 def_key.parent.unwrap()
982 let item = self.entry(item_id);
983 Lrc::from(self.get_attributes(&item, sess))
986 pub fn get_struct_field_names(&self, id: DefIndex) -> Vec<ast::Name> {
990 .map(|index| self.item_name(index))
994 fn get_attributes(&self, item: &Entry<'tcx>, sess: &Session) -> Vec<ast::Attribute> {
996 .decode((self, sess))
998 // Need new unique IDs: old thread-local IDs won't map to new threads.
999 attr.id = attr::mk_attr_id();
1005 // Translate a DefId from the current compilation environment to a DefId
1006 // for an external crate.
1007 fn reverse_translate_def_id(&self, did: DefId) -> Option<DefId> {
1008 for (local, &global) in self.cnum_map.iter_enumerated() {
1009 if global == did.krate {
1020 pub fn get_inherent_implementations_for_type(
1022 tcx: TyCtxt<'tcx, '_>,
1024 ) -> &'tcx [DefId] {
1025 tcx.arena.alloc_from_iter(self.entry(id)
1028 .map(|index| self.local_def_id(index)))
1031 pub fn get_implementations_for_trait(
1033 tcx: TyCtxt<'tcx, '_>,
1034 filter: Option<DefId>,
1035 ) -> &'tcx [DefId] {
1036 if self.proc_macros.is_some() {
1037 // proc-macro crates export no trait impls.
1041 // Do a reverse lookup beforehand to avoid touching the crate_num
1042 // hash map in the loop below.
1043 let filter = match filter.map(|def_id| self.reverse_translate_def_id(def_id)) {
1044 Some(Some(def_id)) => Some((def_id.krate.as_u32(), def_id.index)),
1045 Some(None) => return &[],
1049 if let Some(filter) = filter {
1050 if let Some(impls) = self.trait_impls.get(&filter) {
1051 tcx.arena.alloc_from_iter(impls.decode(self).map(|idx| self.local_def_id(idx)))
1056 tcx.arena.alloc_from_iter(self.trait_impls.values().flat_map(|impls| {
1057 impls.decode(self).map(|idx| self.local_def_id(idx))
1062 pub fn get_trait_of_item(&self, id: DefIndex) -> Option<DefId> {
1063 let def_key = self.def_key(id);
1064 match def_key.disambiguated_data.data {
1065 DefPathData::TypeNs(..) | DefPathData::ValueNs(..) => (),
1066 // Not an associated item
1069 def_key.parent.and_then(|parent_index| {
1070 match self.entry(parent_index).kind {
1071 EntryKind::Trait(_) |
1072 EntryKind::TraitAlias(_) => Some(self.local_def_id(parent_index)),
1079 pub fn get_native_libraries(&self, sess: &Session) -> Vec<NativeLibrary> {
1080 if self.proc_macros.is_some() {
1081 // Proc macro crates do not have any *target* native libraries.
1084 self.root.native_libraries.decode((self, sess)).collect()
1088 pub fn get_foreign_modules(&self, tcx: TyCtxt<'tcx, '_>) -> &'tcx [ForeignModule] {
1089 if self.proc_macros.is_some() {
1090 // Proc macro crates do not have any *target* foreign modules.
1093 tcx.arena.alloc_from_iter(self.root.foreign_modules.decode((self, tcx.sess)))
1097 pub fn get_dylib_dependency_formats(
1099 tcx: TyCtxt<'tcx, '_>,
1100 ) -> &'tcx [(CrateNum, LinkagePreference)] {
1101 tcx.arena.alloc_from_iter(self.root
1102 .dylib_dependency_formats
1105 .flat_map(|(i, link)| {
1106 let cnum = CrateNum::new(i + 1);
1107 link.map(|link| (self.cnum_map[cnum], link))
1111 pub fn get_missing_lang_items(&self, tcx: TyCtxt<'tcx, '_>) -> &'tcx [lang_items::LangItem] {
1112 if self.proc_macros.is_some() {
1113 // Proc macro crates do not depend on any target weak lang-items.
1116 tcx.arena.alloc_from_iter(self.root
1122 pub fn get_fn_arg_names(&self, id: DefIndex) -> Vec<ast::Name> {
1123 let arg_names = match self.entry(id).kind {
1124 EntryKind::Fn(data) |
1125 EntryKind::ForeignFn(data) => data.decode(self).arg_names,
1126 EntryKind::Method(data) => data.decode(self).fn_data.arg_names,
1127 _ => LazySeq::empty(),
1129 arg_names.decode(self).collect()
1132 pub fn exported_symbols(
1134 tcx: TyCtxt<'tcx, 'tcx>,
1135 ) -> Vec<(ExportedSymbol<'tcx>, SymbolExportLevel)> {
1136 if self.proc_macros.is_some() {
1137 // If this crate is a custom derive crate, then we're not even going to
1138 // link those in so we skip those crates.
1141 self.root.exported_symbols.decode((self, tcx)).collect()
1145 pub fn get_rendered_const(&self, id: DefIndex) -> String {
1146 match self.entry(id).kind {
1147 EntryKind::Const(_, data) |
1148 EntryKind::AssocConst(_, _, data) => data.decode(self).0,
1153 pub fn get_macro(&self, id: DefIndex) -> MacroDef {
1154 let entry = self.entry(id);
1156 EntryKind::MacroDef(macro_def) => macro_def.decode(self),
1161 crate fn is_const_fn_raw(&self, id: DefIndex) -> bool {
1162 let constness = match self.entry(id).kind {
1163 EntryKind::Method(data) => data.decode(self).fn_data.constness,
1164 EntryKind::Fn(data) => data.decode(self).constness,
1165 EntryKind::Variant(..) | EntryKind::Struct(..) => hir::Constness::Const,
1166 _ => hir::Constness::NotConst,
1168 constness == hir::Constness::Const
1171 pub fn is_foreign_item(&self, id: DefIndex) -> bool {
1172 match self.entry(id).kind {
1173 EntryKind::ForeignImmStatic |
1174 EntryKind::ForeignMutStatic |
1175 EntryKind::ForeignFn(_) => true,
1180 crate fn static_mutability(&self, id: DefIndex) -> Option<hir::Mutability> {
1181 match self.entry(id).kind {
1182 EntryKind::ImmStatic |
1183 EntryKind::ForeignImmStatic => Some(hir::MutImmutable),
1184 EntryKind::MutStatic |
1185 EntryKind::ForeignMutStatic => Some(hir::MutMutable),
1190 pub fn fn_sig(&self, id: DefIndex, tcx: TyCtxt<'tcx, 'tcx>) -> ty::PolyFnSig<'tcx> {
1191 let sig = match self.entry(id).kind {
1192 EntryKind::Fn(data) |
1193 EntryKind::ForeignFn(data) => data.decode(self).sig,
1194 EntryKind::Method(data) => data.decode(self).fn_data.sig,
1195 EntryKind::Variant(data) |
1196 EntryKind::Struct(data, _) => data.decode(self).ctor_sig.unwrap(),
1197 EntryKind::Closure(data) => data.decode(self).sig,
1200 sig.decode((self, tcx))
1204 pub fn def_key(&self, index: DefIndex) -> DefKey {
1205 self.def_path_table.def_key(index)
1208 // Returns the path leading to the thing with this `id`.
1209 pub fn def_path(&self, id: DefIndex) -> DefPath {
1210 debug!("def_path(cnum={:?}, id={:?})", self.cnum, id);
1211 DefPath::make(self.cnum, id, |parent| self.def_path_table.def_key(parent))
1215 pub fn def_path_hash(&self, index: DefIndex) -> DefPathHash {
1216 self.def_path_table.def_path_hash(index)
1219 /// Imports the source_map from an external crate into the source_map of the crate
1220 /// currently being compiled (the "local crate").
1222 /// The import algorithm works analogous to how AST items are inlined from an
1223 /// external crate's metadata:
1224 /// For every SourceFile in the external source_map an 'inline' copy is created in the
1225 /// local source_map. The correspondence relation between external and local
1226 /// SourceFiles is recorded in the `ImportedSourceFile` objects returned from this
1227 /// function. When an item from an external crate is later inlined into this
1228 /// crate, this correspondence information is used to translate the span
1229 /// information of the inlined item so that it refers the correct positions in
1230 /// the local source_map (see `<decoder::DecodeContext as SpecializedDecoder<Span>>`).
1232 /// The import algorithm in the function below will reuse SourceFiles already
1233 /// existing in the local source_map. For example, even if the SourceFile of some
1234 /// source file of libstd gets imported many times, there will only ever be
1235 /// one SourceFile object for the corresponding file in the local source_map.
1237 /// Note that imported SourceFiles do not actually contain the source code of the
1238 /// file they represent, just information about length, line breaks, and
1239 /// multibyte characters. This information is enough to generate valid debuginfo
1240 /// for items inlined from other crates.
1242 /// Proc macro crates don't currently export spans, so this function does not have
1243 /// to work for them.
1244 pub fn imported_source_files(&'a self,
1245 local_source_map: &source_map::SourceMap)
1246 -> ReadGuard<'a, Vec<cstore::ImportedSourceFile>> {
1248 let source_files = self.source_map_import_info.borrow();
1249 if !source_files.is_empty() {
1250 return source_files;
1254 // Lock the source_map_import_info to ensure this only happens once
1255 let mut source_map_import_info = self.source_map_import_info.borrow_mut();
1257 if !source_map_import_info.is_empty() {
1258 drop(source_map_import_info);
1259 return self.source_map_import_info.borrow();
1262 let external_source_map = self.root.source_map.decode(self);
1264 let imported_source_files = external_source_map.map(|source_file_to_import| {
1265 // We can't reuse an existing SourceFile, so allocate a new one
1266 // containing the information we need.
1267 let syntax_pos::SourceFile { name,
1273 mut multibyte_chars,
1274 mut non_narrow_chars,
1276 .. } = source_file_to_import;
1278 let source_length = (end_pos - start_pos).to_usize();
1280 // Translate line-start positions and multibyte character
1281 // position into frame of reference local to file.
1282 // `SourceMap::new_imported_source_file()` will then translate those
1283 // coordinates to their new global frame of reference when the
1284 // offset of the SourceFile is known.
1285 for pos in &mut lines {
1286 *pos = *pos - start_pos;
1288 for mbc in &mut multibyte_chars {
1289 mbc.pos = mbc.pos - start_pos;
1291 for swc in &mut non_narrow_chars {
1292 *swc = *swc - start_pos;
1295 let local_version = local_source_map.new_imported_source_file(name,
1304 debug!("CrateMetaData::imported_source_files alloc \
1305 source_file {:?} original (start_pos {:?} end_pos {:?}) \
1306 translated (start_pos {:?} end_pos {:?})",
1307 local_version.name, start_pos, end_pos,
1308 local_version.start_pos, local_version.end_pos);
1310 cstore::ImportedSourceFile {
1311 original_start_pos: start_pos,
1312 original_end_pos: end_pos,
1313 translated_source_file: local_version,
1317 *source_map_import_info = imported_source_files;
1318 drop(source_map_import_info);
1320 // This shouldn't borrow twice, but there is no way to downgrade RefMut to Ref.
1321 self.source_map_import_info.borrow()