1 // Decoding metadata from a single crate's metadata
3 use crate::creader::CrateMetadataRef;
4 use crate::rmeta::table::{FixedSizeEncoding, Table};
9 use rustc_attr as attr;
10 use rustc_data_structures::captures::Captures;
11 use rustc_data_structures::fx::FxHashMap;
12 use rustc_data_structures::svh::Svh;
13 use rustc_data_structures::sync::{Lock, LockGuard, Lrc, OnceCell};
14 use rustc_data_structures::unhash::UnhashMap;
15 use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
16 use rustc_expand::proc_macro::{AttrProcMacro, BangProcMacro, ProcMacroDerive};
17 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
18 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
19 use rustc_hir::definitions::{DefKey, DefPath, DefPathData, DefPathHash};
20 use rustc_hir::diagnostic_items::DiagnosticItems;
21 use rustc_hir::lang_items;
22 use rustc_index::vec::{Idx, IndexVec};
23 use rustc_middle::arena::ArenaAllocatable;
24 use rustc_middle::metadata::ModChild;
25 use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
26 use rustc_middle::middle::stability::DeprecationEntry;
27 use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
28 use rustc_middle::thir;
29 use rustc_middle::ty::codec::TyDecoder;
30 use rustc_middle::ty::fast_reject::SimplifiedType;
31 use rustc_middle::ty::{self, Ty, TyCtxt, Visibility};
32 use rustc_serialize::{opaque, Decodable, Decoder};
33 use rustc_session::cstore::{
34 CrateSource, ExternCrate, ForeignModule, LinkagePreference, NativeLib,
36 use rustc_session::Session;
37 use rustc_span::hygiene::{ExpnIndex, MacroKind};
38 use rustc_span::source_map::{respan, Spanned};
39 use rustc_span::symbol::{sym, Ident, Symbol};
40 use rustc_span::{self, BytePos, ExpnId, Pos, Span, SyntaxContext, DUMMY_SP};
42 use proc_macro::bridge::client::ProcMacro;
45 use std::num::NonZeroUsize;
49 pub(super) use cstore_impl::provide;
50 pub use cstore_impl::provide_extern;
51 use rustc_span::hygiene::HygieneDecodeContext;
55 /// A reference to the raw binary version of crate metadata.
56 /// A `MetadataBlob` internally is just a reference counted pointer to
57 /// the actual data, so cloning it is cheap.
59 crate struct MetadataBlob(Lrc<MetadataRef>);
61 // This is needed so we can create an OwningRef into the blob.
62 // The data behind a `MetadataBlob` has a stable address because it is
63 // contained within an Rc/Arc.
64 unsafe impl rustc_data_structures::owning_ref::StableAddress for MetadataBlob {}
66 // This is needed so we can create an OwningRef into the blob.
67 impl std::ops::Deref for MetadataBlob {
71 fn deref(&self) -> &[u8] {
76 // A map from external crate numbers (as decoded from some crate file) to
77 // local crate numbers (as generated during this session). Each external
78 // crate may refer to types in other external crates, and each has their
80 crate type CrateNumMap = IndexVec<CrateNum, CrateNum>;
82 crate struct CrateMetadata {
83 /// The primary crate data - binary metadata blob.
86 // --- Some data pre-decoded from the metadata blob, usually for performance ---
87 /// Properties of the whole crate.
88 /// NOTE(eddyb) we pass `'static` to a `'tcx` parameter because this
89 /// lifetime is only used behind `Lazy`, and therefore acts like a
90 /// universal (`for<'tcx>`), that is paired up with whichever `TyCtxt`
91 /// is being used to decode those values.
92 root: CrateRoot<'static>,
94 /// FIXME: Used only from queries and can use query cache,
95 /// so pre-decoding can probably be avoided.
96 trait_impls: FxHashMap<(u32, DefIndex), Lazy<[(DefIndex, Option<SimplifiedType>)]>>,
97 /// Inherent impls which do not follow the normal coherence rules.
99 /// These can be introduced using either `#![rustc_coherence_is_core]`
100 /// or `#[rustc_allow_incoherent_impl]`.
101 incoherent_impls: FxHashMap<SimplifiedType, Lazy<[DefIndex]>>,
102 /// Proc macro descriptions for this crate, if it's a proc macro crate.
103 raw_proc_macros: Option<&'static [ProcMacro]>,
104 /// Source maps for code from the crate.
105 source_map_import_info: OnceCell<Vec<ImportedSourceFile>>,
106 /// For every definition in this crate, maps its `DefPathHash` to its `DefIndex`.
107 def_path_hash_map: DefPathHashMapRef<'static>,
108 /// Likewise for ExpnHash.
109 expn_hash_map: OnceCell<UnhashMap<ExpnHash, ExpnIndex>>,
110 /// Used for decoding interpret::AllocIds in a cached & thread-safe manner.
111 alloc_decoding_state: AllocDecodingState,
112 /// Caches decoded `DefKey`s.
113 def_key_cache: Lock<FxHashMap<DefIndex, DefKey>>,
114 /// Caches decoded `DefPathHash`es.
115 def_path_hash_cache: Lock<FxHashMap<DefIndex, DefPathHash>>,
117 // --- Other significant crate properties ---
118 /// ID of this crate, from the current compilation session's point of view.
120 /// Maps crate IDs as they are were seen from this crate's compilation sessions into
121 /// IDs as they are seen from the current compilation session.
122 cnum_map: CrateNumMap,
123 /// Same ID set as `cnum_map` plus maybe some injected crates like panic runtime.
124 dependencies: Lock<Vec<CrateNum>>,
125 /// How to link (or not link) this crate to the currently compiled crate.
126 dep_kind: Lock<CrateDepKind>,
127 /// Filesystem location of this crate.
128 source: Lrc<CrateSource>,
129 /// Whether or not this crate should be consider a private dependency
130 /// for purposes of the 'exported_private_dependencies' lint
132 /// The hash for the host proc macro. Used to support `-Z dual-proc-macro`.
133 host_hash: Option<Svh>,
135 /// Additional data used for decoding `HygieneData` (e.g. `SyntaxContext`
137 /// Note that we store a `HygieneDecodeContext` for each `CrateMetadat`. This is
138 /// because `SyntaxContext` ids are not globally unique, so we need
139 /// to track which ids we've decoded on a per-crate basis.
140 hygiene_context: HygieneDecodeContext,
142 // --- Data used only for improving diagnostics ---
143 /// Information about the `extern crate` item or path that caused this crate to be loaded.
144 /// If this is `None`, then the crate was injected (e.g., by the allocator).
145 extern_crate: Lock<Option<ExternCrate>>,
148 /// Holds information about a rustc_span::SourceFile imported from another crate.
149 /// See `imported_source_files()` for more information.
150 struct ImportedSourceFile {
151 /// This SourceFile's byte-offset within the source_map of its original crate
152 original_start_pos: rustc_span::BytePos,
153 /// The end of this SourceFile within the source_map of its original crate
154 original_end_pos: rustc_span::BytePos,
155 /// The imported SourceFile's representation within the local source_map
156 translated_source_file: Lrc<rustc_span::SourceFile>,
159 pub(super) struct DecodeContext<'a, 'tcx> {
160 opaque: opaque::Decoder<'a>,
161 cdata: Option<CrateMetadataRef<'a>>,
162 blob: &'a MetadataBlob,
163 sess: Option<&'tcx Session>,
164 tcx: Option<TyCtxt<'tcx>>,
166 // Cache the last used source_file for translating spans as an optimization.
167 last_source_file_index: usize,
169 lazy_state: LazyState,
171 // Used for decoding interpret::AllocIds in a cached & thread-safe manner.
172 alloc_decoding_session: Option<AllocDecodingSession<'a>>,
175 /// Abstract over the various ways one can create metadata decoders.
176 pub(super) trait Metadata<'a, 'tcx>: Copy {
177 fn blob(self) -> &'a MetadataBlob;
179 fn cdata(self) -> Option<CrateMetadataRef<'a>> {
182 fn sess(self) -> Option<&'tcx Session> {
185 fn tcx(self) -> Option<TyCtxt<'tcx>> {
189 fn decoder(self, pos: usize) -> DecodeContext<'a, 'tcx> {
190 let tcx = self.tcx();
192 opaque: opaque::Decoder::new(self.blob(), pos),
195 sess: self.sess().or(tcx.map(|tcx| tcx.sess)),
197 last_source_file_index: 0,
198 lazy_state: LazyState::NoNode,
199 alloc_decoding_session: self
201 .map(|cdata| cdata.cdata.alloc_decoding_state.new_decoding_session()),
206 impl<'a, 'tcx> Metadata<'a, 'tcx> for &'a MetadataBlob {
208 fn blob(self) -> &'a MetadataBlob {
213 impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a MetadataBlob, &'tcx Session) {
215 fn blob(self) -> &'a MetadataBlob {
220 fn sess(self) -> Option<&'tcx Session> {
221 let (_, sess) = self;
226 impl<'a, 'tcx> Metadata<'a, 'tcx> for CrateMetadataRef<'a> {
228 fn blob(self) -> &'a MetadataBlob {
232 fn cdata(self) -> Option<CrateMetadataRef<'a>> {
237 impl<'a, 'tcx> Metadata<'a, 'tcx> for (CrateMetadataRef<'a>, &'tcx Session) {
239 fn blob(self) -> &'a MetadataBlob {
243 fn cdata(self) -> Option<CrateMetadataRef<'a>> {
247 fn sess(self) -> Option<&'tcx Session> {
252 impl<'a, 'tcx> Metadata<'a, 'tcx> for (CrateMetadataRef<'a>, TyCtxt<'tcx>) {
254 fn blob(self) -> &'a MetadataBlob {
258 fn cdata(self) -> Option<CrateMetadataRef<'a>> {
262 fn tcx(self) -> Option<TyCtxt<'tcx>> {
267 impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> Lazy<T> {
268 fn decode<M: Metadata<'a, 'tcx>>(self, metadata: M) -> T {
269 let mut dcx = metadata.decoder(self.position.get());
270 dcx.lazy_state = LazyState::NodeStart(self.position);
275 impl<'a: 'x, 'tcx: 'x, 'x, T: Decodable<DecodeContext<'a, 'tcx>>> Lazy<[T]> {
276 fn decode<M: Metadata<'a, 'tcx>>(
279 ) -> impl ExactSizeIterator<Item = T> + Captures<'a> + Captures<'tcx> + 'x {
280 let mut dcx = metadata.decoder(self.position.get());
281 dcx.lazy_state = LazyState::NodeStart(self.position);
282 (0..self.meta).map(move |_| T::decode(&mut dcx))
286 trait LazyQueryDecodable<'a, 'tcx, T> {
289 cdata: CrateMetadataRef<'a>,
291 err: impl FnOnce() -> !,
295 impl<'a, 'tcx, T> LazyQueryDecodable<'a, 'tcx, T> for Option<Lazy<T>>
297 T: Decodable<DecodeContext<'a, 'tcx>>,
301 cdata: CrateMetadataRef<'a>,
303 err: impl FnOnce() -> !,
305 if let Some(l) = self { l.decode((cdata, tcx)) } else { err() }
309 impl<'a, 'tcx, T> LazyQueryDecodable<'a, 'tcx, &'tcx T> for Option<Lazy<T>>
311 T: Decodable<DecodeContext<'a, 'tcx>>,
312 T: ArenaAllocatable<'tcx>,
316 cdata: CrateMetadataRef<'a>,
318 err: impl FnOnce() -> !,
320 if let Some(l) = self { tcx.arena.alloc(l.decode((cdata, tcx))) } else { err() }
324 impl<'a, 'tcx, T> LazyQueryDecodable<'a, 'tcx, Option<T>> for Option<Lazy<T>>
326 T: Decodable<DecodeContext<'a, 'tcx>>,
330 cdata: CrateMetadataRef<'a>,
332 _err: impl FnOnce() -> !,
334 self.map(|l| l.decode((cdata, tcx)))
338 impl<'a, 'tcx, T, E> LazyQueryDecodable<'a, 'tcx, Result<Option<T>, E>> for Option<Lazy<T>>
340 T: Decodable<DecodeContext<'a, 'tcx>>,
344 cdata: CrateMetadataRef<'a>,
346 _err: impl FnOnce() -> !,
347 ) -> Result<Option<T>, E> {
348 Ok(self.map(|l| l.decode((cdata, tcx))))
352 impl<'a, 'tcx, T> LazyQueryDecodable<'a, 'tcx, &'tcx [T]> for Option<Lazy<[T], usize>>
354 T: Decodable<DecodeContext<'a, 'tcx>> + Copy,
358 cdata: CrateMetadataRef<'a>,
360 _err: impl FnOnce() -> !,
362 if let Some(l) = self { tcx.arena.alloc_from_iter(l.decode((cdata, tcx))) } else { &[] }
366 impl<'a, 'tcx> LazyQueryDecodable<'a, 'tcx, Option<DeprecationEntry>>
367 for Option<Lazy<attr::Deprecation>>
371 cdata: CrateMetadataRef<'a>,
373 _err: impl FnOnce() -> !,
374 ) -> Option<DeprecationEntry> {
375 self.map(|l| l.decode((cdata, tcx))).map(DeprecationEntry::external)
379 impl<'a, 'tcx> DecodeContext<'a, 'tcx> {
381 fn tcx(&self) -> TyCtxt<'tcx> {
382 debug_assert!(self.tcx.is_some(), "missing TyCtxt in DecodeContext");
387 pub fn blob(&self) -> &'a MetadataBlob {
392 pub fn cdata(&self) -> CrateMetadataRef<'a> {
393 debug_assert!(self.cdata.is_some(), "missing CrateMetadata in DecodeContext");
397 fn map_encoded_cnum_to_current(&self, cnum: CrateNum) -> CrateNum {
398 if cnum == LOCAL_CRATE { self.cdata().cnum } else { self.cdata().cnum_map[cnum] }
401 fn read_lazy_with_meta<T: ?Sized + LazyMeta>(&mut self, meta: T::Meta) -> Lazy<T> {
402 let distance = self.read_usize();
403 let position = match self.lazy_state {
404 LazyState::NoNode => bug!("read_lazy_with_meta: outside of a metadata node"),
405 LazyState::NodeStart(start) => {
406 let start = start.get();
407 assert!(distance <= start);
410 LazyState::Previous(last_pos) => last_pos.get() + distance,
412 self.lazy_state = LazyState::Previous(NonZeroUsize::new(position).unwrap());
413 Lazy::from_position_and_meta(NonZeroUsize::new(position).unwrap(), meta)
417 pub fn read_raw_bytes(&mut self, len: usize) -> &[u8] {
418 self.opaque.read_raw_bytes(len)
422 impl<'a, 'tcx> TyDecoder<'tcx> for DecodeContext<'a, 'tcx> {
423 const CLEAR_CROSS_CRATE: bool = true;
426 fn tcx(&self) -> TyCtxt<'tcx> {
427 self.tcx.expect("missing TyCtxt in DecodeContext")
431 fn peek_byte(&self) -> u8 {
432 self.opaque.data[self.opaque.position()]
436 fn position(&self) -> usize {
437 self.opaque.position()
440 fn cached_ty_for_shorthand<F>(&mut self, shorthand: usize, or_insert_with: F) -> Ty<'tcx>
442 F: FnOnce(&mut Self) -> Ty<'tcx>,
444 let tcx = self.tcx();
446 let key = ty::CReaderCacheKey { cnum: Some(self.cdata().cnum), pos: shorthand };
448 if let Some(&ty) = tcx.ty_rcache.borrow().get(&key) {
452 let ty = or_insert_with(self);
453 tcx.ty_rcache.borrow_mut().insert(key, ty);
457 fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
459 F: FnOnce(&mut Self) -> R,
461 let new_opaque = opaque::Decoder::new(self.opaque.data, pos);
462 let old_opaque = mem::replace(&mut self.opaque, new_opaque);
463 let old_state = mem::replace(&mut self.lazy_state, LazyState::NoNode);
465 self.opaque = old_opaque;
466 self.lazy_state = old_state;
470 fn decode_alloc_id(&mut self) -> rustc_middle::mir::interpret::AllocId {
471 if let Some(alloc_decoding_session) = self.alloc_decoding_session {
472 alloc_decoding_session.decode_alloc_id(self)
474 bug!("Attempting to decode interpret::AllocId without CrateMetadata")
479 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for CrateNum {
480 fn decode(d: &mut DecodeContext<'a, 'tcx>) -> CrateNum {
481 let cnum = CrateNum::from_u32(d.read_u32());
482 d.map_encoded_cnum_to_current(cnum)
486 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for DefIndex {
487 fn decode(d: &mut DecodeContext<'a, 'tcx>) -> DefIndex {
488 DefIndex::from_u32(d.read_u32())
492 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for ExpnIndex {
493 fn decode(d: &mut DecodeContext<'a, 'tcx>) -> ExpnIndex {
494 ExpnIndex::from_u32(d.read_u32())
498 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for SyntaxContext {
499 fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> SyntaxContext {
500 let cdata = decoder.cdata();
501 let sess = decoder.sess.unwrap();
502 let cname = cdata.root.name;
503 rustc_span::hygiene::decode_syntax_context(decoder, &cdata.hygiene_context, |_, id| {
504 debug!("SpecializedDecoder<SyntaxContext>: decoding {}", id);
509 .unwrap_or_else(|| panic!("Missing SyntaxContext {:?} for crate {:?}", id, cname))
510 .decode((cdata, sess))
515 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for ExpnId {
516 fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> ExpnId {
517 let local_cdata = decoder.cdata();
518 let sess = decoder.sess.unwrap();
520 let cnum = CrateNum::decode(decoder);
521 let index = u32::decode(decoder);
523 let expn_id = rustc_span::hygiene::decode_expn_id(cnum, index, |expn_id| {
524 let ExpnId { krate: cnum, local_id: index } = expn_id;
525 // Lookup local `ExpnData`s in our own crate data. Foreign `ExpnData`s
526 // are stored in the owning crate, to avoid duplication.
527 debug_assert_ne!(cnum, LOCAL_CRATE);
528 let crate_data = if cnum == local_cdata.cnum {
531 local_cdata.cstore.get_crate_data(cnum)
533 let expn_data = crate_data
536 .get(crate_data, index)
538 .decode((crate_data, sess));
539 let expn_hash = crate_data
542 .get(crate_data, index)
544 .decode((crate_data, sess));
545 (expn_data, expn_hash)
551 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for Span {
552 fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Span {
553 let ctxt = SyntaxContext::decode(decoder);
554 let tag = u8::decode(decoder);
556 if tag == TAG_PARTIAL_SPAN {
557 return DUMMY_SP.with_ctxt(ctxt);
560 debug_assert!(tag == TAG_VALID_SPAN_LOCAL || tag == TAG_VALID_SPAN_FOREIGN);
562 let lo = BytePos::decode(decoder);
563 let len = BytePos::decode(decoder);
566 let Some(sess) = decoder.sess else {
567 bug!("Cannot decode Span without Session.")
570 // There are two possibilities here:
571 // 1. This is a 'local span', which is located inside a `SourceFile`
572 // that came from this crate. In this case, we use the source map data
573 // encoded in this crate. This branch should be taken nearly all of the time.
574 // 2. This is a 'foreign span', which is located inside a `SourceFile`
575 // that came from a *different* crate (some crate upstream of the one
576 // whose metadata we're looking at). For example, consider this dependency graph:
580 // Suppose that we're currently compiling crate A, and start deserializing
581 // metadata from crate B. When we deserialize a Span from crate B's metadata,
582 // there are two possibilities:
584 // 1. The span references a file from crate B. This makes it a 'local' span,
585 // which means that we can use crate B's serialized source map information.
586 // 2. The span references a file from crate C. This makes it a 'foreign' span,
587 // which means we need to use Crate *C* (not crate B) to determine the source
588 // map information. We only record source map information for a file in the
589 // crate that 'owns' it, so deserializing a Span may require us to look at
590 // a transitive dependency.
592 // When we encode a foreign span, we adjust its 'lo' and 'high' values
593 // to be based on the *foreign* crate (e.g. crate C), not the crate
594 // we are writing metadata for (e.g. crate B). This allows us to
595 // treat the 'local' and 'foreign' cases almost identically during deserialization:
596 // we can call `imported_source_files` for the proper crate, and binary search
597 // through the returned slice using our span.
598 let imported_source_files = if tag == TAG_VALID_SPAN_LOCAL {
599 decoder.cdata().imported_source_files(sess)
601 // When we encode a proc-macro crate, all `Span`s should be encoded
602 // with `TAG_VALID_SPAN_LOCAL`
603 if decoder.cdata().root.is_proc_macro_crate() {
604 // Decode `CrateNum` as u32 - using `CrateNum::decode` will ICE
605 // since we don't have `cnum_map` populated.
606 let cnum = u32::decode(decoder);
608 "Decoding of crate {:?} tried to access proc-macro dep {:?}",
609 decoder.cdata().root.name,
613 // tag is TAG_VALID_SPAN_FOREIGN, checked by `debug_assert` above
614 let cnum = CrateNum::decode(decoder);
616 "SpecializedDecoder<Span>::specialized_decode: loading source files from cnum {:?}",
620 // Decoding 'foreign' spans should be rare enough that it's
621 // not worth it to maintain a per-CrateNum cache for `last_source_file_index`.
622 // We just set it to 0, to ensure that we don't try to access something out
623 // of bounds for our initial 'guess'
624 decoder.last_source_file_index = 0;
626 let foreign_data = decoder.cdata().cstore.get_crate_data(cnum);
627 foreign_data.imported_source_files(sess)
631 // Optimize for the case that most spans within a translated item
632 // originate from the same source_file.
633 let last_source_file = &imported_source_files[decoder.last_source_file_index];
635 if lo >= last_source_file.original_start_pos && lo <= last_source_file.original_end_pos
639 let index = imported_source_files
640 .binary_search_by_key(&lo, |source_file| source_file.original_start_pos)
641 .unwrap_or_else(|index| index - 1);
643 // Don't try to cache the index for foreign spans,
644 // as this would require a map from CrateNums to indices
645 if tag == TAG_VALID_SPAN_LOCAL {
646 decoder.last_source_file_index = index;
648 &imported_source_files[index]
652 // Make sure our binary search above is correct.
654 lo >= source_file.original_start_pos && lo <= source_file.original_end_pos,
655 "Bad binary search: lo={:?} source_file.original_start_pos={:?} source_file.original_end_pos={:?}",
657 source_file.original_start_pos,
658 source_file.original_end_pos
661 // Make sure we correctly filtered out invalid spans during encoding
663 hi >= source_file.original_start_pos && hi <= source_file.original_end_pos,
664 "Bad binary search: hi={:?} source_file.original_start_pos={:?} source_file.original_end_pos={:?}",
666 source_file.original_start_pos,
667 source_file.original_end_pos
671 (lo + source_file.translated_source_file.start_pos) - source_file.original_start_pos;
673 (hi + source_file.translated_source_file.start_pos) - source_file.original_start_pos;
675 // Do not try to decode parent for foreign spans.
676 Span::new(lo, hi, ctxt, None)
680 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for &'tcx [thir::abstract_const::Node<'tcx>] {
681 fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Self {
682 ty::codec::RefDecodable::decode(d)
686 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for &'tcx [(ty::Predicate<'tcx>, Span)] {
687 fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Self {
688 ty::codec::RefDecodable::decode(d)
692 impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> Decodable<DecodeContext<'a, 'tcx>>
695 fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
696 decoder.read_lazy_with_meta(())
700 impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> Decodable<DecodeContext<'a, 'tcx>>
703 fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
704 let len = decoder.read_usize();
705 if len == 0 { Lazy::empty() } else { decoder.read_lazy_with_meta(len) }
709 impl<'a, 'tcx, I: Idx, T: Decodable<DecodeContext<'a, 'tcx>>> Decodable<DecodeContext<'a, 'tcx>>
710 for Lazy<Table<I, T>>
712 Option<T>: FixedSizeEncoding,
714 fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
715 let len = decoder.read_usize();
716 decoder.read_lazy_with_meta(len)
720 implement_ty_decoder!(DecodeContext<'a, 'tcx>);
722 impl<'tcx> MetadataBlob {
723 crate fn new(metadata_ref: MetadataRef) -> MetadataBlob {
724 MetadataBlob(Lrc::new(metadata_ref))
727 crate fn is_compatible(&self) -> bool {
728 self.blob().starts_with(METADATA_HEADER)
731 crate fn get_rustc_version(&self) -> String {
732 Lazy::<String>::from_position(NonZeroUsize::new(METADATA_HEADER.len() + 4).unwrap())
736 crate fn get_root(&self) -> CrateRoot<'tcx> {
737 let slice = &self.blob()[..];
738 let offset = METADATA_HEADER.len();
739 let pos = (((slice[offset + 0] as u32) << 24)
740 | ((slice[offset + 1] as u32) << 16)
741 | ((slice[offset + 2] as u32) << 8)
742 | ((slice[offset + 3] as u32) << 0)) as usize;
743 Lazy::<CrateRoot<'tcx>>::from_position(NonZeroUsize::new(pos).unwrap()).decode(self)
746 crate fn list_crate_metadata(&self, out: &mut dyn io::Write) -> io::Result<()> {
747 let root = self.get_root();
748 writeln!(out, "Crate info:")?;
749 writeln!(out, "name {}{}", root.name, root.extra_filename)?;
750 writeln!(out, "hash {} stable_crate_id {:?}", root.hash, root.stable_crate_id)?;
751 writeln!(out, "proc_macro {:?}", root.proc_macro_data.is_some())?;
752 writeln!(out, "=External Dependencies=")?;
753 for (i, dep) in root.crate_deps.decode(self).enumerate() {
756 "{} {}{} hash {} host_hash {:?} kind {:?}",
771 crate fn is_proc_macro_crate(&self) -> bool {
772 self.proc_macro_data.is_some()
775 crate fn name(&self) -> Symbol {
779 crate fn hash(&self) -> Svh {
783 crate fn stable_crate_id(&self) -> StableCrateId {
787 crate fn triple(&self) -> &TargetTriple {
791 crate fn decode_crate_deps<'a>(
793 metadata: &'a MetadataBlob,
794 ) -> impl ExactSizeIterator<Item = CrateDep> + Captures<'a> {
795 self.crate_deps.decode(metadata)
799 impl<'a, 'tcx> CrateMetadataRef<'a> {
800 fn raw_proc_macro(self, id: DefIndex) -> &'a ProcMacro {
801 // DefIndex's in root.proc_macro_data have a one-to-one correspondence
802 // with items in 'raw_proc_macros'.
810 .position(|i| i == id)
812 &self.raw_proc_macros.unwrap()[pos]
815 fn opt_item_name(self, item_index: DefIndex) -> Option<Symbol> {
816 self.def_key(item_index).disambiguated_data.data.get_opt_name()
819 fn item_name(self, item_index: DefIndex) -> Symbol {
820 self.opt_item_name(item_index).expect("no encoded ident for item")
823 fn opt_item_ident(self, item_index: DefIndex, sess: &Session) -> Option<Ident> {
824 let name = self.opt_item_name(item_index)?;
825 let span = match self.root.tables.def_ident_span.get(self, item_index) {
826 Some(lazy_span) => lazy_span.decode((self, sess)),
828 // FIXME: this weird case of a name with no span is specific to `extern crate`
829 // items, which are supposed to be treated like `use` items and only be encoded
830 // to metadata as `Export`s, return `None` because that's what all the callers
831 // expect in this case.
832 assert_eq!(self.def_kind(item_index), DefKind::ExternCrate);
836 Some(Ident::new(name, span))
839 fn item_ident(self, item_index: DefIndex, sess: &Session) -> Ident {
840 self.opt_item_ident(item_index, sess).expect("no encoded ident for item")
843 fn maybe_kind(self, item_id: DefIndex) -> Option<EntryKind> {
844 self.root.tables.kind.get(self, item_id).map(|k| k.decode(self))
847 fn kind(self, item_id: DefIndex) -> EntryKind {
848 self.maybe_kind(item_id).unwrap_or_else(|| {
850 "CrateMetadata::kind({:?}): id not found, in crate {:?} with number {}",
858 fn def_kind(self, item_id: DefIndex) -> DefKind {
859 self.root.tables.opt_def_kind.get(self, item_id).map(|k| k.decode(self)).unwrap_or_else(
862 "CrateMetadata::def_kind({:?}): id not found, in crate {:?} with number {}",
871 fn get_span(self, index: DefIndex, sess: &Session) -> Span {
876 .unwrap_or_else(|| panic!("Missing span for {:?}", index))
877 .decode((self, sess))
880 fn load_proc_macro(self, id: DefIndex, sess: &Session) -> SyntaxExtension {
881 let (name, kind, helper_attrs) = match *self.raw_proc_macro(id) {
882 ProcMacro::CustomDerive { trait_name, attributes, client } => {
884 attributes.iter().cloned().map(Symbol::intern).collect::<Vec<_>>();
887 SyntaxExtensionKind::Derive(Box::new(ProcMacroDerive { client })),
891 ProcMacro::Attr { name, client } => {
892 (name, SyntaxExtensionKind::Attr(Box::new(AttrProcMacro { client })), Vec::new())
894 ProcMacro::Bang { name, client } => {
895 (name, SyntaxExtensionKind::Bang(Box::new(BangProcMacro { client })), Vec::new())
899 let attrs: Vec<_> = self.get_item_attrs(id, sess).collect();
900 SyntaxExtension::new(
903 self.get_span(id, sess),
906 Symbol::intern(name),
911 fn get_variant(self, kind: &EntryKind, index: DefIndex, parent_did: DefId) -> ty::VariantDef {
912 let data = match kind {
913 EntryKind::Variant(data) | EntryKind::Struct(data) | EntryKind::Union(data) => {
919 let adt_kind = match kind {
920 EntryKind::Variant(_) => ty::AdtKind::Enum,
921 EntryKind::Struct(..) => ty::AdtKind::Struct,
922 EntryKind::Union(..) => ty::AdtKind::Union,
927 if adt_kind == ty::AdtKind::Enum { Some(self.local_def_id(index)) } else { None };
928 let ctor_did = data.ctor.map(|index| self.local_def_id(index));
931 self.item_name(index),
939 .unwrap_or_else(Lazy::empty)
941 .map(|index| ty::FieldDef {
942 did: self.local_def_id(index),
943 name: self.item_name(index),
944 vis: self.get_visibility(index),
951 data.is_non_exhaustive,
955 fn get_adt_def(self, item_id: DefIndex, tcx: TyCtxt<'tcx>) -> ty::AdtDef<'tcx> {
956 let kind = self.kind(item_id);
957 let did = self.local_def_id(item_id);
959 let adt_kind = match kind {
960 EntryKind::Enum => ty::AdtKind::Enum,
961 EntryKind::Struct(_) => ty::AdtKind::Struct,
962 EntryKind::Union(_) => ty::AdtKind::Union,
963 _ => bug!("get_adt_def called on a non-ADT {:?}", did),
965 let repr = self.root.tables.repr_options.get(self, item_id).unwrap().decode(self);
967 let variants = if let ty::AdtKind::Enum = adt_kind {
972 .unwrap_or_else(Lazy::empty)
974 .map(|index| self.get_variant(&self.kind(index), index, did))
977 std::iter::once(self.get_variant(&kind, item_id, did)).collect()
980 tcx.alloc_adt_def(did, adt_kind, variants, repr)
983 fn get_generics(self, item_id: DefIndex, sess: &Session) -> ty::Generics {
984 self.root.tables.generics_of.get(self, item_id).unwrap().decode((self, sess))
987 fn get_visibility(self, id: DefIndex) -> ty::Visibility {
988 self.root.tables.visibility.get(self, id).unwrap().decode(self)
991 fn get_trait_item_def_id(self, id: DefIndex) -> Option<DefId> {
992 self.root.tables.trait_item_def_id.get(self, id).map(|d| d.decode(self))
995 fn get_expn_that_defined(self, id: DefIndex, sess: &Session) -> ExpnId {
996 self.root.tables.expn_that_defined.get(self, id).unwrap().decode((self, sess))
999 /// Iterates over all the stability attributes in the given crate.
1000 fn get_lib_features(self, tcx: TyCtxt<'tcx>) -> &'tcx [(Symbol, Option<Symbol>)] {
1001 tcx.arena.alloc_from_iter(self.root.lib_features.decode(self))
1004 /// Iterates over the language items in the given crate.
1005 fn get_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, usize)] {
1006 tcx.arena.alloc_from_iter(
1010 .map(move |(def_index, index)| (self.local_def_id(def_index), index)),
1014 /// Iterates over the diagnostic items in the given crate.
1015 fn get_diagnostic_items(self) -> DiagnosticItems {
1016 let mut id_to_name = FxHashMap::default();
1017 let name_to_id = self
1021 .map(|(name, def_index)| {
1022 let id = self.local_def_id(def_index);
1023 id_to_name.insert(id, name);
1027 DiagnosticItems { id_to_name, name_to_id }
1030 /// Iterates over all named children of the given module,
1031 /// including both proper items and reexports.
1032 /// Module here is understood in name resolution sense - it can be a `mod` item,
1033 /// or a crate root, or an enum, or a trait.
1034 fn for_each_module_child(
1037 mut callback: impl FnMut(ModChild),
1040 if let Some(data) = &self.root.proc_macro_data {
1041 // If we are loading as a proc macro, we want to return
1042 // the view of this crate as a proc macro crate.
1043 if id == CRATE_DEF_INDEX {
1044 for def_index in data.macros.decode(self) {
1045 let raw_macro = self.raw_proc_macro(def_index);
1047 DefKind::Macro(macro_kind(raw_macro)),
1048 self.local_def_id(def_index),
1050 let ident = self.item_ident(def_index, sess);
1054 vis: ty::Visibility::Public,
1063 // Iterate over all children.
1064 if let Some(children) = self.root.tables.children.get(self, id) {
1065 for child_index in children.decode((self, sess)) {
1066 if let Some(ident) = self.opt_item_ident(child_index, sess) {
1067 let kind = self.def_kind(child_index);
1068 let def_id = self.local_def_id(child_index);
1069 let res = Res::Def(kind, def_id);
1070 let vis = self.get_visibility(child_index);
1071 let span = self.get_span(child_index, sess);
1072 let macro_rules = match kind {
1073 DefKind::Macro(..) => match self.kind(child_index) {
1074 EntryKind::MacroDef(_, macro_rules) => macro_rules,
1075 _ => unreachable!(),
1080 callback(ModChild { ident, res, vis, span, macro_rules });
1082 // For non-re-export structs and variants add their constructors to children.
1083 // Re-export lists automatically contain constructors when necessary.
1085 DefKind::Struct => {
1086 if let Some((ctor_def_id, ctor_kind)) =
1087 self.get_ctor_def_id_and_kind(child_index)
1090 Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id);
1091 let vis = self.get_visibility(ctor_def_id.index);
1101 DefKind::Variant => {
1102 // Braced variants, unlike structs, generate unusable names in
1103 // value namespace, they are reserved for possible future use.
1104 // It's ok to use the variant's id as a ctor id since an
1105 // error will be reported on any use of such resolution anyway.
1106 let (ctor_def_id, ctor_kind) = self
1107 .get_ctor_def_id_and_kind(child_index)
1108 .unwrap_or((def_id, CtorKind::Fictive));
1110 Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
1111 let mut vis = self.get_visibility(ctor_def_id.index);
1112 if ctor_def_id == def_id && vis.is_public() {
1113 // For non-exhaustive variants lower the constructor visibility to
1114 // within the crate. We only need this for fictive constructors,
1115 // for other constructors correct visibilities
1116 // were already encoded in metadata.
1117 let mut attrs = self.get_item_attrs(def_id.index, sess);
1118 if attrs.any(|item| item.has_name(sym::non_exhaustive)) {
1119 let crate_def_id = self.local_def_id(CRATE_DEF_INDEX);
1120 vis = ty::Visibility::Restricted(crate_def_id);
1137 match self.kind(id) {
1138 EntryKind::Mod(exports) => {
1139 for exp in exports.decode((self, sess)) {
1143 EntryKind::Enum | EntryKind::Trait => {}
1144 _ => bug!("`for_each_module_child` is called on a non-module: {:?}", self.def_kind(id)),
1148 fn is_ctfe_mir_available(self, id: DefIndex) -> bool {
1149 self.root.tables.mir_for_ctfe.get(self, id).is_some()
1152 fn is_item_mir_available(self, id: DefIndex) -> bool {
1153 self.root.tables.optimized_mir.get(self, id).is_some()
1156 fn module_expansion(self, id: DefIndex, sess: &Session) -> ExpnId {
1157 match self.kind(id) {
1158 EntryKind::Mod(_) | EntryKind::Enum | EntryKind::Trait => {
1159 self.get_expn_that_defined(id, sess)
1161 _ => panic!("Expected module, found {:?}", self.local_def_id(id)),
1165 fn get_fn_has_self_parameter(self, id: DefIndex) -> bool {
1166 match self.kind(id) {
1167 EntryKind::AssocFn(data) => data.decode(self).has_self,
1172 fn get_associated_item_def_ids(
1176 ) -> impl Iterator<Item = DefId> + 'a {
1181 .unwrap_or_else(Lazy::empty)
1182 .decode((self, sess))
1183 .map(move |child_index| self.local_def_id(child_index))
1186 fn get_associated_item(self, id: DefIndex) -> ty::AssocItem {
1187 let def_key = self.def_key(id);
1188 let parent = self.local_def_id(def_key.parent.unwrap());
1189 let name = self.item_name(id);
1191 let (kind, container, has_self) = match self.kind(id) {
1192 EntryKind::AssocConst(container) => (ty::AssocKind::Const, container, false),
1193 EntryKind::AssocFn(data) => {
1194 let data = data.decode(self);
1195 (ty::AssocKind::Fn, data.container, data.has_self)
1197 EntryKind::AssocType(container) => (ty::AssocKind::Type, container, false),
1198 _ => bug!("cannot get associated-item of `{:?}`", def_key),
1204 vis: self.get_visibility(id),
1205 defaultness: container.defaultness(),
1206 def_id: self.local_def_id(id),
1207 trait_item_def_id: self.get_trait_item_def_id(id),
1208 container: container.with_def_id(parent),
1209 fn_has_self_parameter: has_self,
1213 fn get_ctor_def_id_and_kind(self, node_id: DefIndex) -> Option<(DefId, CtorKind)> {
1214 match self.kind(node_id) {
1215 EntryKind::Struct(data) | EntryKind::Variant(data) => {
1216 let vdata = data.decode(self);
1217 vdata.ctor.map(|index| (self.local_def_id(index), vdata.ctor_kind))
1227 ) -> impl Iterator<Item = ast::Attribute> + 'a {
1232 .unwrap_or_else(|| {
1233 // Structure and variant constructors don't have any attributes encoded for them,
1234 // but we assume that someone passing a constructor ID actually wants to look at
1235 // the attributes on the corresponding struct or variant.
1236 let def_key = self.def_key(id);
1237 assert_eq!(def_key.disambiguated_data.data, DefPathData::Ctor);
1238 let parent_id = def_key.parent.expect("no parent for a constructor");
1242 .get(self, parent_id)
1243 .expect("no encoded attributes for a structure or variant")
1245 .decode((self, sess))
1248 fn get_struct_field_names(
1252 ) -> impl Iterator<Item = Spanned<Symbol>> + 'a {
1257 .unwrap_or_else(Lazy::empty)
1259 .map(move |index| respan(self.get_span(index, sess), self.item_name(index)))
1262 fn get_struct_field_visibilities(self, id: DefIndex) -> impl Iterator<Item = Visibility> + 'a {
1267 .unwrap_or_else(Lazy::empty)
1269 .map(move |field_index| self.get_visibility(field_index))
1272 fn get_inherent_implementations_for_type(
1276 ) -> &'tcx [DefId] {
1277 tcx.arena.alloc_from_iter(
1282 .unwrap_or_else(Lazy::empty)
1284 .map(|index| self.local_def_id(index)),
1288 /// Decodes all inherent impls in the crate (for rustdoc).
1289 fn get_inherent_impls(self) -> impl Iterator<Item = (DefId, DefId)> + 'a {
1290 (0..self.root.tables.inherent_impls.size()).flat_map(move |i| {
1291 let ty_index = DefIndex::from_usize(i);
1292 let ty_def_id = self.local_def_id(ty_index);
1296 .get(self, ty_index)
1297 .unwrap_or_else(Lazy::empty)
1299 .map(move |impl_index| (ty_def_id, self.local_def_id(impl_index)))
1303 /// Decodes all traits in the crate (for rustdoc and rustc diagnostics).
1304 fn get_traits(self) -> impl Iterator<Item = DefId> + 'a {
1305 self.root.traits.decode(self).map(move |index| self.local_def_id(index))
1308 /// Decodes all trait impls in the crate (for rustdoc).
1309 fn get_trait_impls(self) -> impl Iterator<Item = (DefId, DefId, Option<SimplifiedType>)> + 'a {
1310 self.cdata.trait_impls.iter().flat_map(move |(&(trait_cnum_raw, trait_index), impls)| {
1311 let trait_def_id = DefId {
1312 krate: self.cnum_map[CrateNum::from_u32(trait_cnum_raw)],
1315 impls.decode(self).map(move |(impl_index, simplified_self_ty)| {
1316 (trait_def_id, self.local_def_id(impl_index), simplified_self_ty)
1321 fn get_all_incoherent_impls(self) -> impl Iterator<Item = DefId> + 'a {
1325 .flat_map(move |impls| impls.decode(self).map(move |idx| self.local_def_id(idx)))
1328 fn get_incoherent_impls(self, tcx: TyCtxt<'tcx>, simp: SimplifiedType) -> &'tcx [DefId] {
1329 if let Some(impls) = self.cdata.incoherent_impls.get(&simp) {
1330 tcx.arena.alloc_from_iter(impls.decode(self).map(|idx| self.local_def_id(idx)))
1336 fn get_implementations_of_trait(
1339 trait_def_id: DefId,
1340 ) -> &'tcx [(DefId, Option<SimplifiedType>)] {
1341 if self.trait_impls.is_empty() {
1345 // Do a reverse lookup beforehand to avoid touching the crate_num
1346 // hash map in the loop below.
1347 let key = match self.reverse_translate_def_id(trait_def_id) {
1348 Some(def_id) => (def_id.krate.as_u32(), def_id.index),
1352 if let Some(impls) = self.trait_impls.get(&key) {
1353 tcx.arena.alloc_from_iter(
1356 .map(|(idx, simplified_self_ty)| (self.local_def_id(idx), simplified_self_ty)),
1363 fn get_trait_of_item(self, id: DefIndex) -> Option<DefId> {
1364 let def_key = self.def_key(id);
1365 match def_key.disambiguated_data.data {
1366 DefPathData::TypeNs(..) | DefPathData::ValueNs(..) => (),
1367 // Not an associated item
1370 def_key.parent.and_then(|parent_index| match self.kind(parent_index) {
1371 EntryKind::Trait | EntryKind::TraitAlias => Some(self.local_def_id(parent_index)),
1376 fn get_native_libraries(self, sess: &'a Session) -> impl Iterator<Item = NativeLib> + 'a {
1377 self.root.native_libraries.decode((self, sess))
1380 fn get_proc_macro_quoted_span(self, index: usize, sess: &Session) -> Span {
1383 .proc_macro_quoted_spans
1385 .unwrap_or_else(|| panic!("Missing proc macro quoted span: {:?}", index))
1386 .decode((self, sess))
1389 fn get_foreign_modules(self, sess: &'a Session) -> impl Iterator<Item = ForeignModule> + '_ {
1390 self.root.foreign_modules.decode((self, sess))
1393 fn get_dylib_dependency_formats(
1396 ) -> &'tcx [(CrateNum, LinkagePreference)] {
1397 tcx.arena.alloc_from_iter(
1398 self.root.dylib_dependency_formats.decode(self).enumerate().flat_map(|(i, link)| {
1399 let cnum = CrateNum::new(i + 1);
1400 link.map(|link| (self.cnum_map[cnum], link))
1405 fn get_missing_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [lang_items::LangItem] {
1406 tcx.arena.alloc_from_iter(self.root.lang_items_missing.decode(self))
1409 fn exported_symbols(
1412 ) -> &'tcx [(ExportedSymbol<'tcx>, SymbolExportLevel)] {
1413 tcx.arena.alloc_from_iter(self.root.exported_symbols.decode((self, tcx)))
1416 fn get_macro(self, id: DefIndex, sess: &Session) -> ast::MacroDef {
1417 match self.kind(id) {
1418 EntryKind::MacroDef(mac_args, macro_rules) => {
1419 ast::MacroDef { body: P(mac_args.decode((self, sess))), macro_rules }
1425 fn is_foreign_item(self, id: DefIndex) -> bool {
1426 match self.kind(id) {
1427 EntryKind::ForeignStatic | EntryKind::ForeignFn => true,
1433 fn def_key(self, index: DefIndex) -> DefKey {
1438 .or_insert_with(|| self.root.tables.def_keys.get(self, index).unwrap().decode(self))
1441 // Returns the path leading to the thing with this `id`.
1442 fn def_path(self, id: DefIndex) -> DefPath {
1443 debug!("def_path(cnum={:?}, id={:?})", self.cnum, id);
1444 DefPath::make(self.cnum, id, |parent| self.def_key(parent))
1447 fn def_path_hash_unlocked(
1450 def_path_hashes: &mut FxHashMap<DefIndex, DefPathHash>,
1452 *def_path_hashes.entry(index).or_insert_with(|| {
1453 self.root.tables.def_path_hashes.get(self, index).unwrap().decode(self)
1458 fn def_path_hash(self, index: DefIndex) -> DefPathHash {
1459 let mut def_path_hashes = self.def_path_hash_cache.lock();
1460 self.def_path_hash_unlocked(index, &mut def_path_hashes)
1464 fn def_path_hash_to_def_index(self, hash: DefPathHash) -> DefIndex {
1465 self.def_path_hash_map.def_path_hash_to_def_index(&hash)
1468 fn expn_hash_to_expn_id(self, sess: &Session, index_guess: u32, hash: ExpnHash) -> ExpnId {
1469 debug_assert_eq!(ExpnId::from_hash(hash), None);
1470 let index_guess = ExpnIndex::from_u32(index_guess);
1471 let old_hash = self.root.expn_hashes.get(self, index_guess).map(|lazy| lazy.decode(self));
1473 let index = if old_hash == Some(hash) {
1474 // Fast path: the expn and its index is unchanged from the
1475 // previous compilation session. There is no need to decode anything
1479 // Slow path: We need to find out the new `DefIndex` of the provided
1480 // `DefPathHash`, if its still exists. This requires decoding every `DefPathHash`
1481 // stored in this crate.
1482 let map = self.cdata.expn_hash_map.get_or_init(|| {
1483 let end_id = self.root.expn_hashes.size() as u32;
1485 UnhashMap::with_capacity_and_hasher(end_id as usize, Default::default());
1486 for i in 0..end_id {
1487 let i = ExpnIndex::from_u32(i);
1488 if let Some(hash) = self.root.expn_hashes.get(self, i) {
1489 map.insert(hash.decode(self), i);
1497 let data = self.root.expn_data.get(self, index).unwrap().decode((self, sess));
1498 rustc_span::hygiene::register_expn_id(self.cnum, index, data, hash)
1501 /// Imports the source_map from an external crate into the source_map of the crate
1502 /// currently being compiled (the "local crate").
1504 /// The import algorithm works analogous to how AST items are inlined from an
1505 /// external crate's metadata:
1506 /// For every SourceFile in the external source_map an 'inline' copy is created in the
1507 /// local source_map. The correspondence relation between external and local
1508 /// SourceFiles is recorded in the `ImportedSourceFile` objects returned from this
1509 /// function. When an item from an external crate is later inlined into this
1510 /// crate, this correspondence information is used to translate the span
1511 /// information of the inlined item so that it refers the correct positions in
1512 /// the local source_map (see `<decoder::DecodeContext as SpecializedDecoder<Span>>`).
1514 /// The import algorithm in the function below will reuse SourceFiles already
1515 /// existing in the local source_map. For example, even if the SourceFile of some
1516 /// source file of libstd gets imported many times, there will only ever be
1517 /// one SourceFile object for the corresponding file in the local source_map.
1519 /// Note that imported SourceFiles do not actually contain the source code of the
1520 /// file they represent, just information about length, line breaks, and
1521 /// multibyte characters. This information is enough to generate valid debuginfo
1522 /// for items inlined from other crates.
1524 /// Proc macro crates don't currently export spans, so this function does not have
1525 /// to work for them.
1526 fn imported_source_files(self, sess: &Session) -> &'a [ImportedSourceFile] {
1527 // Translate the virtual `/rustc/$hash` prefix back to a real directory
1528 // that should hold actual sources, where possible.
1530 // NOTE: if you update this, you might need to also update bootstrap's code for generating
1531 // the `rust-src` component in `Src::run` in `src/bootstrap/dist.rs`.
1532 let virtual_rust_source_base_dir = option_env!("CFG_VIRTUAL_RUST_SOURCE_BASE_DIR")
1535 // Only spend time on further checks if we have what to translate *to*.
1536 sess.opts.real_rust_source_base_dir.is_some()
1538 .filter(|virtual_dir| {
1539 // Don't translate away `/rustc/$hash` if we're still remapping to it,
1540 // since that means we're still building `std`/`rustc` that need it,
1541 // and we don't want the real path to leak into codegen/debuginfo.
1542 !sess.opts.remap_path_prefix.iter().any(|(_from, to)| to == virtual_dir)
1544 let try_to_translate_virtual_to_real = |name: &mut rustc_span::FileName| {
1546 "try_to_translate_virtual_to_real(name={:?}): \
1547 virtual_rust_source_base_dir={:?}, real_rust_source_base_dir={:?}",
1548 name, virtual_rust_source_base_dir, sess.opts.real_rust_source_base_dir,
1551 if let Some(virtual_dir) = virtual_rust_source_base_dir {
1552 if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
1553 if let rustc_span::FileName::Real(old_name) = name {
1554 if let rustc_span::RealFileName::Remapped { local_path: _, virtual_name } =
1557 if let Ok(rest) = virtual_name.strip_prefix(virtual_dir) {
1558 let virtual_name = virtual_name.clone();
1560 // The std library crates are in
1561 // `$sysroot/lib/rustlib/src/rust/library`, whereas other crates
1562 // may be in `$sysroot/lib/rustlib/src/rust/` directly. So we
1563 // detect crates from the std libs and handle them specially.
1564 const STD_LIBS: &[&str] = &[
1574 "profiler_builtins",
1576 "rustc-std-workspace-core",
1577 "rustc-std-workspace-alloc",
1578 "rustc-std-workspace-std",
1581 let is_std_lib = STD_LIBS.iter().any(|l| rest.starts_with(l));
1583 let new_path = if is_std_lib {
1584 real_dir.join("library").join(rest)
1590 "try_to_translate_virtual_to_real: `{}` -> `{}`",
1591 virtual_name.display(),
1594 let new_name = rustc_span::RealFileName::Remapped {
1595 local_path: Some(new_path),
1598 *old_name = new_name;
1606 self.cdata.source_map_import_info.get_or_init(|| {
1607 let external_source_map = self.root.source_map.decode(self);
1610 .map(|source_file_to_import| {
1611 // We can't reuse an existing SourceFile, so allocate a new one
1612 // containing the information we need.
1613 let rustc_span::SourceFile {
1619 mut multibyte_chars,
1620 mut non_narrow_chars,
1624 } = source_file_to_import;
1626 // If this file is under $sysroot/lib/rustlib/src/ but has not been remapped
1627 // during rust bootstrapping by `remap-debuginfo = true`, and the user
1628 // wish to simulate that behaviour by -Z simulate-remapped-rust-src-base,
1629 // then we change `name` to a similar state as if the rust was bootstrapped
1630 // with `remap-debuginfo = true`.
1631 // This is useful for testing so that tests about the effects of
1632 // `try_to_translate_virtual_to_real` don't have to worry about how the
1633 // compiler is bootstrapped.
1634 if let Some(virtual_dir) =
1635 &sess.opts.debugging_opts.simulate_remapped_rust_src_base
1637 if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
1638 if let rustc_span::FileName::Real(ref mut old_name) = name {
1639 if let rustc_span::RealFileName::LocalPath(local) = old_name {
1640 if let Ok(rest) = local.strip_prefix(real_dir) {
1641 *old_name = rustc_span::RealFileName::Remapped {
1643 virtual_name: virtual_dir.join(rest),
1651 // If this file's path has been remapped to `/rustc/$hash`,
1652 // we might be able to reverse that (also see comments above,
1653 // on `try_to_translate_virtual_to_real`).
1654 try_to_translate_virtual_to_real(&mut name);
1656 let source_length = (end_pos - start_pos).to_usize();
1658 // Translate line-start positions and multibyte character
1659 // position into frame of reference local to file.
1660 // `SourceMap::new_imported_source_file()` will then translate those
1661 // coordinates to their new global frame of reference when the
1662 // offset of the SourceFile is known.
1663 for pos in &mut lines {
1664 *pos = *pos - start_pos;
1666 for mbc in &mut multibyte_chars {
1667 mbc.pos = mbc.pos - start_pos;
1669 for swc in &mut non_narrow_chars {
1670 *swc = *swc - start_pos;
1672 for np in &mut normalized_pos {
1673 np.pos = np.pos - start_pos;
1676 let local_version = sess.source_map().new_imported_source_file(
1690 "CrateMetaData::imported_source_files alloc \
1691 source_file {:?} original (start_pos {:?} end_pos {:?}) \
1692 translated (start_pos {:?} end_pos {:?})",
1696 local_version.start_pos,
1697 local_version.end_pos
1700 ImportedSourceFile {
1701 original_start_pos: start_pos,
1702 original_end_pos: end_pos,
1703 translated_source_file: local_version,
1711 impl CrateMetadata {
1715 root: CrateRoot<'static>,
1716 raw_proc_macros: Option<&'static [ProcMacro]>,
1718 cnum_map: CrateNumMap,
1719 dep_kind: CrateDepKind,
1720 source: CrateSource,
1722 host_hash: Option<Svh>,
1723 ) -> CrateMetadata {
1724 let trait_impls = root
1726 .decode((&blob, sess))
1727 .map(|trait_impls| (trait_impls.trait_id, trait_impls.impls))
1729 let incoherent_impls = root
1731 .decode((&blob, sess))
1732 .map(|incoherent_impls| (incoherent_impls.self_ty, incoherent_impls.impls))
1734 let alloc_decoding_state =
1735 AllocDecodingState::new(root.interpret_alloc_index.decode(&blob).collect());
1736 let dependencies = Lock::new(cnum_map.iter().cloned().collect());
1738 // Pre-decode the DefPathHash->DefIndex table. This is a cheap operation
1739 // that does not copy any data. It just does some data verification.
1740 let def_path_hash_map = root.def_path_hash_map.decode(&blob);
1748 source_map_import_info: OnceCell::new(),
1750 expn_hash_map: Default::default(),
1751 alloc_decoding_state,
1755 dep_kind: Lock::new(dep_kind),
1756 source: Lrc::new(source),
1759 extern_crate: Lock::new(None),
1760 hygiene_context: Default::default(),
1761 def_key_cache: Default::default(),
1762 def_path_hash_cache: Default::default(),
1766 crate fn dependencies(&self) -> LockGuard<'_, Vec<CrateNum>> {
1767 self.dependencies.borrow()
1770 crate fn add_dependency(&self, cnum: CrateNum) {
1771 self.dependencies.borrow_mut().push(cnum);
1774 crate fn update_extern_crate(&self, new_extern_crate: ExternCrate) -> bool {
1775 let mut extern_crate = self.extern_crate.borrow_mut();
1776 let update = Some(new_extern_crate.rank()) > extern_crate.as_ref().map(ExternCrate::rank);
1778 *extern_crate = Some(new_extern_crate);
1783 crate fn source(&self) -> &CrateSource {
1787 crate fn dep_kind(&self) -> CrateDepKind {
1788 *self.dep_kind.lock()
1791 crate fn update_dep_kind(&self, f: impl FnOnce(CrateDepKind) -> CrateDepKind) {
1792 self.dep_kind.with_lock(|dep_kind| *dep_kind = f(*dep_kind))
1795 crate fn panic_strategy(&self) -> PanicStrategy {
1796 self.root.panic_strategy
1799 crate fn needs_panic_runtime(&self) -> bool {
1800 self.root.needs_panic_runtime
1803 crate fn is_panic_runtime(&self) -> bool {
1804 self.root.panic_runtime
1807 crate fn is_profiler_runtime(&self) -> bool {
1808 self.root.profiler_runtime
1811 crate fn needs_allocator(&self) -> bool {
1812 self.root.needs_allocator
1815 crate fn has_global_allocator(&self) -> bool {
1816 self.root.has_global_allocator
1819 crate fn has_default_lib_allocator(&self) -> bool {
1820 self.root.has_default_lib_allocator
1823 crate fn is_proc_macro_crate(&self) -> bool {
1824 self.root.is_proc_macro_crate()
1827 crate fn name(&self) -> Symbol {
1831 crate fn stable_crate_id(&self) -> StableCrateId {
1832 self.root.stable_crate_id
1835 crate fn hash(&self) -> Svh {
1839 fn num_def_ids(&self) -> usize {
1840 self.root.tables.def_keys.size()
1843 fn local_def_id(&self, index: DefIndex) -> DefId {
1844 DefId { krate: self.cnum, index }
1847 // Translate a DefId from the current compilation environment to a DefId
1848 // for an external crate.
1849 fn reverse_translate_def_id(&self, did: DefId) -> Option<DefId> {
1850 for (local, &global) in self.cnum_map.iter_enumerated() {
1851 if global == did.krate {
1852 return Some(DefId { krate: local, index: did.index });
1860 // Cannot be implemented on 'ProcMacro', as libproc_macro
1861 // does not depend on librustc_ast
1862 fn macro_kind(raw: &ProcMacro) -> MacroKind {
1864 ProcMacro::CustomDerive { .. } => MacroKind::Derive,
1865 ProcMacro::Attr { .. } => MacroKind::Attr,
1866 ProcMacro::Bang { .. } => MacroKind::Bang,