2 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
3 use rustc_data_structures::memmap::Mmap;
4 use rustc_data_structures::sync::{HashMapExt, Lock, Lrc, RwLock};
5 use rustc_data_structures::unhash::UnhashMap;
6 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, StableCrateId, LOCAL_CRATE};
7 use rustc_hir::definitions::DefPathHash;
8 use rustc_index::vec::{Idx, IndexVec};
9 use rustc_middle::dep_graph::{DepNodeIndex, SerializedDepNodeIndex};
10 use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
11 use rustc_middle::mir::{self, interpret};
12 use rustc_middle::thir;
13 use rustc_middle::ty::codec::{RefDecodable, TyDecoder, TyEncoder};
14 use rustc_middle::ty::{self, Ty, TyCtxt};
15 use rustc_query_system::dep_graph::DepContext;
16 use rustc_query_system::query::{QueryContext, QuerySideEffects};
17 use rustc_serialize::{
18 opaque::{self, FileEncodeResult, FileEncoder, IntEncodedWithFixedSize},
19 Decodable, Decoder, Encodable, Encoder,
21 use rustc_session::Session;
22 use rustc_span::hygiene::{
23 ExpnId, HygieneDecodeContext, HygieneEncodeContext, SyntaxContext, SyntaxContextData,
25 use rustc_span::source_map::{SourceMap, StableSourceFileId};
26 use rustc_span::CachingSourceMapView;
27 use rustc_span::{BytePos, ExpnData, ExpnHash, Pos, SourceFile, Span};
30 const TAG_FILE_FOOTER: u128 = 0xC0FFEE_C0FFEE_C0FFEE_C0FFEE_C0FFEE;
32 // A normal span encoded with both location information and a `SyntaxContext`
33 const TAG_FULL_SPAN: u8 = 0;
34 // A partial span with no location information, encoded only with a `SyntaxContext`
35 const TAG_PARTIAL_SPAN: u8 = 1;
36 const TAG_RELATIVE_SPAN: u8 = 2;
38 const TAG_SYNTAX_CONTEXT: u8 = 0;
39 const TAG_EXPN_DATA: u8 = 1;
41 /// Provides an interface to incremental compilation data cached from the
42 /// previous compilation session. This data will eventually include the results
43 /// of a few selected queries (like `typeck` and `mir_optimized`) and
44 /// any side effects that have been emitted during a query.
45 pub struct OnDiskCache<'sess> {
46 // The complete cache data in serialized form.
47 serialized_data: RwLock<Option<Mmap>>,
49 // Collects all `QuerySideEffects` created during the current compilation
51 current_side_effects: Lock<FxHashMap<DepNodeIndex, QuerySideEffects>>,
53 source_map: &'sess SourceMap,
54 file_index_to_stable_id: FxHashMap<SourceFileIndex, EncodedSourceFileId>,
56 // Caches that are populated lazily during decoding.
57 file_index_to_file: Lock<FxHashMap<SourceFileIndex, Lrc<SourceFile>>>,
59 // A map from dep-node to the position of the cached query result in
61 query_result_index: FxHashMap<SerializedDepNodeIndex, AbsoluteBytePos>,
63 // A map from dep-node to the position of any associated `QuerySideEffects` in
65 prev_side_effects_index: FxHashMap<SerializedDepNodeIndex, AbsoluteBytePos>,
67 alloc_decoding_state: AllocDecodingState,
69 // A map from syntax context ids to the position of their associated
70 // `SyntaxContextData`. We use a `u32` instead of a `SyntaxContext`
71 // to represent the fact that we are storing *encoded* ids. When we decode
72 // a `SyntaxContext`, a new id will be allocated from the global `HygieneData`,
73 // which will almost certainly be different than the serialized id.
74 syntax_contexts: FxHashMap<u32, AbsoluteBytePos>,
75 // A map from the `DefPathHash` of an `ExpnId` to the position
76 // of their associated `ExpnData`. Ideally, we would store a `DefId`,
77 // but we need to decode this before we've constructed a `TyCtxt` (which
78 // makes it difficult to decode a `DefId`).
80 // Note that these `DefPathHashes` correspond to both local and foreign
81 // `ExpnData` (e.g `ExpnData.krate` may not be `LOCAL_CRATE`). Alternatively,
82 // we could look up the `ExpnData` from the metadata of foreign crates,
83 // but it seemed easier to have `OnDiskCache` be independent of the `CStore`.
84 expn_data: UnhashMap<ExpnHash, AbsoluteBytePos>,
85 // Additional information used when decoding hygiene data.
86 hygiene_context: HygieneDecodeContext,
87 // Maps `ExpnHash`es to their raw value from the *previous*
88 // compilation session. This is used as an initial 'guess' when
89 // we try to map an `ExpnHash` to its value in the current
90 // compilation session.
91 foreign_expn_data: UnhashMap<ExpnHash, u32>,
94 // This type is used only for serialization and deserialization.
95 #[derive(Encodable, Decodable)]
97 file_index_to_stable_id: FxHashMap<SourceFileIndex, EncodedSourceFileId>,
98 query_result_index: EncodedDepNodeIndex,
99 side_effects_index: EncodedDepNodeIndex,
100 // The location of all allocations.
101 interpret_alloc_index: Vec<u32>,
102 // See `OnDiskCache.syntax_contexts`
103 syntax_contexts: FxHashMap<u32, AbsoluteBytePos>,
104 // See `OnDiskCache.expn_data`
105 expn_data: UnhashMap<ExpnHash, AbsoluteBytePos>,
106 foreign_expn_data: UnhashMap<ExpnHash, u32>,
109 pub type EncodedDepNodeIndex = Vec<(SerializedDepNodeIndex, AbsoluteBytePos)>;
111 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, Encodable, Decodable)]
112 struct SourceFileIndex(u32);
114 #[derive(Copy, Clone, Debug, Hash, Eq, PartialEq, Encodable, Decodable)]
115 pub struct AbsoluteBytePos(u32);
117 impl AbsoluteBytePos {
118 fn new(pos: usize) -> AbsoluteBytePos {
119 debug_assert!(pos <= u32::MAX as usize);
120 AbsoluteBytePos(pos as u32)
123 fn to_usize(self) -> usize {
128 /// An `EncodedSourceFileId` is the same as a `StableSourceFileId` except that
129 /// the source crate is represented as a [StableCrateId] instead of as a
130 /// `CrateNum`. This way `EncodedSourceFileId` can be encoded and decoded
131 /// without any additional context, i.e. with a simple `opaque::Decoder` (which
132 /// is the only thing available when decoding the cache's [Footer].
133 #[derive(Encodable, Decodable, Clone, Debug)]
134 struct EncodedSourceFileId {
136 stable_crate_id: StableCrateId,
139 impl EncodedSourceFileId {
140 fn translate(&self, tcx: TyCtxt<'_>) -> StableSourceFileId {
141 let cnum = tcx.stable_crate_id_to_crate_num(self.stable_crate_id);
142 StableSourceFileId { file_name_hash: self.file_name_hash, cnum }
145 fn new(tcx: TyCtxt<'_>, file: &SourceFile) -> EncodedSourceFileId {
146 let source_file_id = StableSourceFileId::new(file);
147 EncodedSourceFileId {
148 file_name_hash: source_file_id.file_name_hash,
149 stable_crate_id: tcx.stable_crate_id(source_file_id.cnum),
154 impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
155 /// Creates a new `OnDiskCache` instance from the serialized data in `data`.
156 fn new(sess: &'sess Session, data: Mmap, start_pos: usize) -> Self {
157 debug_assert!(sess.opts.incremental.is_some());
159 // Wrap in a scope so we can borrow `data`.
160 let footer: Footer = {
161 let mut decoder = opaque::Decoder::new(&data, start_pos);
163 // Decode the *position* of the footer, which can be found in the
164 // last 8 bytes of the file.
165 decoder.set_position(data.len() - IntEncodedWithFixedSize::ENCODED_SIZE);
166 let footer_pos = IntEncodedWithFixedSize::decode(&mut decoder).0 as usize;
168 // Decode the file footer, which contains all the lookup tables, etc.
169 decoder.set_position(footer_pos);
171 decode_tagged(&mut decoder, TAG_FILE_FOOTER)
175 serialized_data: RwLock::new(Some(data)),
176 file_index_to_stable_id: footer.file_index_to_stable_id,
177 file_index_to_file: Default::default(),
178 source_map: sess.source_map(),
179 current_side_effects: Default::default(),
180 query_result_index: footer.query_result_index.into_iter().collect(),
181 prev_side_effects_index: footer.side_effects_index.into_iter().collect(),
182 alloc_decoding_state: AllocDecodingState::new(footer.interpret_alloc_index),
183 syntax_contexts: footer.syntax_contexts,
184 expn_data: footer.expn_data,
185 foreign_expn_data: footer.foreign_expn_data,
186 hygiene_context: Default::default(),
190 fn new_empty(source_map: &'sess SourceMap) -> Self {
192 serialized_data: RwLock::new(None),
193 file_index_to_stable_id: Default::default(),
194 file_index_to_file: Default::default(),
196 current_side_effects: Default::default(),
197 query_result_index: Default::default(),
198 prev_side_effects_index: Default::default(),
199 alloc_decoding_state: AllocDecodingState::new(Vec::new()),
200 syntax_contexts: FxHashMap::default(),
201 expn_data: UnhashMap::default(),
202 foreign_expn_data: UnhashMap::default(),
203 hygiene_context: Default::default(),
207 /// Execute all cache promotions and release the serialized backing Mmap.
209 /// Cache promotions require invoking queries, which needs to read the serialized data.
210 /// In order to serialize the new on-disk cache, the former on-disk cache file needs to be
211 /// deleted, hence we won't be able to refer to its memmapped data.
212 fn drop_serialized_data(&self, tcx: TyCtxt<'_>) {
213 // Load everything into memory so we can write it out to the on-disk
214 // cache. The vast majority of cacheable query results should already
215 // be in memory, so this should be a cheap operation.
216 // Do this *before* we clone 'latest_foreign_def_path_hashes', since
217 // loading existing queries may cause us to create new DepNodes, which
218 // may in turn end up invoking `store_foreign_def_id_hash`
219 tcx.dep_graph.exec_cache_promotions(tcx);
221 *self.serialized_data.write() = None;
224 fn serialize<'tcx>(&self, tcx: TyCtxt<'tcx>, encoder: &mut FileEncoder) -> FileEncodeResult {
225 // Serializing the `DepGraph` should not modify it.
226 tcx.dep_graph.with_ignore(|| {
227 // Allocate `SourceFileIndex`es.
228 let (file_to_file_index, file_index_to_stable_id) = {
229 let files = tcx.sess.source_map().files();
230 let mut file_to_file_index =
231 FxHashMap::with_capacity_and_hasher(files.len(), Default::default());
232 let mut file_index_to_stable_id =
233 FxHashMap::with_capacity_and_hasher(files.len(), Default::default());
235 for (index, file) in files.iter().enumerate() {
236 let index = SourceFileIndex(index as u32);
237 let file_ptr: *const SourceFile = &**file as *const _;
238 file_to_file_index.insert(file_ptr, index);
239 let source_file_id = EncodedSourceFileId::new(tcx, &file);
240 file_index_to_stable_id.insert(index, source_file_id);
243 (file_to_file_index, file_index_to_stable_id)
246 let hygiene_encode_context = HygieneEncodeContext::default();
248 let mut encoder = CacheEncoder {
251 type_shorthands: Default::default(),
252 predicate_shorthands: Default::default(),
253 interpret_allocs: Default::default(),
254 source_map: CachingSourceMapView::new(tcx.sess.source_map()),
256 hygiene_context: &hygiene_encode_context,
259 // Encode query results.
260 let mut query_result_index = EncodedDepNodeIndex::new();
262 tcx.sess.time("encode_query_results", || -> FileEncodeResult {
263 let enc = &mut encoder;
264 let qri = &mut query_result_index;
265 QueryCtxt::from_tcx(tcx).encode_query_results(enc, qri)
268 // Encode side effects.
269 let side_effects_index: EncodedDepNodeIndex = self
270 .current_side_effects
274 |(dep_node_index, side_effects)| -> Result<_, <FileEncoder as Encoder>::Error> {
275 let pos = AbsoluteBytePos::new(encoder.position());
276 let dep_node_index = SerializedDepNodeIndex::new(dep_node_index.index());
277 encoder.encode_tagged(dep_node_index, side_effects)?;
279 Ok((dep_node_index, pos))
282 .collect::<Result<_, _>>()?;
284 let interpret_alloc_index = {
285 let mut interpret_alloc_index = Vec::new();
288 let new_n = encoder.interpret_allocs.len();
289 // If we have found new IDs, serialize those too.
294 interpret_alloc_index.reserve(new_n - n);
295 for idx in n..new_n {
296 let id = encoder.interpret_allocs[idx];
297 let pos = encoder.position() as u32;
298 interpret_alloc_index.push(pos);
299 interpret::specialized_encode_alloc_id(&mut encoder, tcx, id)?;
303 interpret_alloc_index
306 let mut syntax_contexts = FxHashMap::default();
307 let mut expn_data = UnhashMap::default();
308 let mut foreign_expn_data = UnhashMap::default();
310 // Encode all hygiene data (`SyntaxContextData` and `ExpnData`) from the current
313 hygiene_encode_context.encode(
315 |encoder, index, ctxt_data| -> FileEncodeResult {
316 let pos = AbsoluteBytePos::new(encoder.position());
317 encoder.encode_tagged(TAG_SYNTAX_CONTEXT, ctxt_data)?;
318 syntax_contexts.insert(index, pos);
321 |encoder, expn_id, data, hash| -> FileEncodeResult {
322 if expn_id.krate == LOCAL_CRATE {
323 let pos = AbsoluteBytePos::new(encoder.position());
324 encoder.encode_tagged(TAG_EXPN_DATA, data)?;
325 expn_data.insert(hash, pos);
327 foreign_expn_data.insert(hash, expn_id.local_id.as_u32());
333 // `Encode the file footer.
334 let footer_pos = encoder.position() as u64;
335 encoder.encode_tagged(
338 file_index_to_stable_id,
341 interpret_alloc_index,
348 // Encode the position of the footer as the last 8 bytes of the
349 // file so we know where to look for it.
350 IntEncodedWithFixedSize(footer_pos).encode(encoder.encoder)?;
352 // DO NOT WRITE ANYTHING TO THE ENCODER AFTER THIS POINT! The address
353 // of the footer must be the last thing in the data stream.
360 impl<'sess> OnDiskCache<'sess> {
361 pub fn as_dyn(&self) -> &dyn rustc_middle::ty::OnDiskCache<'sess> {
365 /// Loads a `QuerySideEffects` created during the previous compilation session.
366 pub fn load_side_effects(
369 dep_node_index: SerializedDepNodeIndex,
370 ) -> QuerySideEffects {
371 let side_effects: Option<QuerySideEffects> =
372 self.load_indexed(tcx, dep_node_index, &self.prev_side_effects_index);
374 side_effects.unwrap_or_default()
377 /// Stores a `QuerySideEffects` emitted during the current compilation session.
378 /// Anything stored like this will be available via `load_side_effects` in
379 /// the next compilation session.
382 pub fn store_side_effects(&self, dep_node_index: DepNodeIndex, side_effects: QuerySideEffects) {
383 let mut current_side_effects = self.current_side_effects.borrow_mut();
384 let prev = current_side_effects.insert(dep_node_index, side_effects);
385 debug_assert!(prev.is_none());
388 /// Returns the cached query result if there is something in the cache for
389 /// the given `SerializedDepNodeIndex`; otherwise returns `None`.
390 pub fn try_load_query_result<'tcx, T>(
393 dep_node_index: SerializedDepNodeIndex,
396 T: for<'a> Decodable<CacheDecoder<'a, 'tcx>>,
398 self.load_indexed(tcx, dep_node_index, &self.query_result_index)
401 /// Stores side effect emitted during computation of an anonymous query.
402 /// Since many anonymous queries can share the same `DepNode`, we aggregate
403 /// them -- as opposed to regular queries where we assume that there is a
404 /// 1:1 relationship between query-key and `DepNode`.
407 pub fn store_side_effects_for_anon_node(
409 dep_node_index: DepNodeIndex,
410 side_effects: QuerySideEffects,
412 let mut current_side_effects = self.current_side_effects.borrow_mut();
414 let x = current_side_effects.entry(dep_node_index).or_default();
415 x.append(side_effects);
418 fn load_indexed<'tcx, T>(
421 dep_node_index: SerializedDepNodeIndex,
422 index: &FxHashMap<SerializedDepNodeIndex, AbsoluteBytePos>,
425 T: for<'a> Decodable<CacheDecoder<'a, 'tcx>>,
427 let pos = index.get(&dep_node_index).cloned()?;
429 self.with_decoder(tcx, pos, |decoder| Some(decode_tagged(decoder, dep_node_index)))
432 fn with_decoder<'a, 'tcx, T, F: for<'s> FnOnce(&mut CacheDecoder<'s, 'tcx>) -> T>(
435 pos: AbsoluteBytePos,
439 T: Decodable<CacheDecoder<'a, 'tcx>>,
441 let serialized_data = self.serialized_data.read();
442 let mut decoder = CacheDecoder {
444 opaque: opaque::Decoder::new(serialized_data.as_deref().unwrap_or(&[]), pos.to_usize()),
445 source_map: self.source_map,
446 file_index_to_file: &self.file_index_to_file,
447 file_index_to_stable_id: &self.file_index_to_stable_id,
448 alloc_decoding_session: self.alloc_decoding_state.new_decoding_session(),
449 syntax_contexts: &self.syntax_contexts,
450 expn_data: &self.expn_data,
451 foreign_expn_data: &self.foreign_expn_data,
452 hygiene_context: &self.hygiene_context,
458 //- DECODING -------------------------------------------------------------------
460 /// A decoder that can read from the incremental compilation cache. It is similar to the one
461 /// we use for crate metadata decoding in that it can rebase spans and eventually
462 /// will also handle things that contain `Ty` instances.
463 pub struct CacheDecoder<'a, 'tcx> {
465 opaque: opaque::Decoder<'a>,
466 source_map: &'a SourceMap,
467 file_index_to_file: &'a Lock<FxHashMap<SourceFileIndex, Lrc<SourceFile>>>,
468 file_index_to_stable_id: &'a FxHashMap<SourceFileIndex, EncodedSourceFileId>,
469 alloc_decoding_session: AllocDecodingSession<'a>,
470 syntax_contexts: &'a FxHashMap<u32, AbsoluteBytePos>,
471 expn_data: &'a UnhashMap<ExpnHash, AbsoluteBytePos>,
472 foreign_expn_data: &'a UnhashMap<ExpnHash, u32>,
473 hygiene_context: &'a HygieneDecodeContext,
476 impl<'a, 'tcx> CacheDecoder<'a, 'tcx> {
477 fn file_index_to_file(&self, index: SourceFileIndex) -> Lrc<SourceFile> {
480 ref file_index_to_file,
481 ref file_index_to_stable_id,
490 let stable_id = file_index_to_stable_id[&index].translate(tcx);
492 // If this `SourceFile` is from a foreign crate, then make sure
493 // that we've imported all of the source files from that crate.
494 // This has usually already been done during macro invocation.
495 // However, when encoding query results like `TypeckResults`,
496 // we might encode an `AdtDef` for a foreign type (because it
497 // was referenced in the body of the function). There is no guarantee
498 // that we will load the source files from that crate during macro
499 // expansion, so we use `import_source_files` to ensure that the foreign
500 // source files are actually imported before we call `source_file_by_stable_id`.
501 if stable_id.cnum != LOCAL_CRATE {
502 self.tcx.cstore_untracked().import_source_files(self.tcx.sess, stable_id.cnum);
506 .source_file_by_stable_id(stable_id)
507 .expect("failed to lookup `SourceFile` in new context")
513 trait DecoderWithPosition: Decoder {
514 fn position(&self) -> usize;
517 impl<'a> DecoderWithPosition for opaque::Decoder<'a> {
518 fn position(&self) -> usize {
523 impl<'a, 'tcx> DecoderWithPosition for CacheDecoder<'a, 'tcx> {
524 fn position(&self) -> usize {
525 self.opaque.position()
529 // Decodes something that was encoded with `encode_tagged()` and verify that the
530 // tag matches and the correct amount of bytes was read.
531 fn decode_tagged<D, T, V>(decoder: &mut D, expected_tag: T) -> V
533 T: Decodable<D> + Eq + std::fmt::Debug,
535 D: DecoderWithPosition,
537 let start_pos = decoder.position();
539 let actual_tag = T::decode(decoder);
540 assert_eq!(actual_tag, expected_tag);
541 let value = V::decode(decoder);
542 let end_pos = decoder.position();
544 let expected_len: u64 = Decodable::decode(decoder);
545 assert_eq!((end_pos - start_pos) as u64, expected_len);
550 impl<'a, 'tcx> TyDecoder<'tcx> for CacheDecoder<'a, 'tcx> {
551 const CLEAR_CROSS_CRATE: bool = false;
554 fn tcx(&self) -> TyCtxt<'tcx> {
559 fn position(&self) -> usize {
560 self.opaque.position()
564 fn peek_byte(&self) -> u8 {
565 self.opaque.data[self.opaque.position()]
568 fn cached_ty_for_shorthand<F>(&mut self, shorthand: usize, or_insert_with: F) -> Ty<'tcx>
570 F: FnOnce(&mut Self) -> Ty<'tcx>,
572 let tcx = self.tcx();
574 let cache_key = ty::CReaderCacheKey { cnum: None, pos: shorthand };
576 if let Some(&ty) = tcx.ty_rcache.borrow().get(&cache_key) {
580 let ty = or_insert_with(self);
581 // This may overwrite the entry, but it should overwrite with the same value.
582 tcx.ty_rcache.borrow_mut().insert_same(cache_key, ty);
586 fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
588 F: FnOnce(&mut Self) -> R,
590 debug_assert!(pos < self.opaque.data.len());
592 let new_opaque = opaque::Decoder::new(self.opaque.data, pos);
593 let old_opaque = mem::replace(&mut self.opaque, new_opaque);
595 self.opaque = old_opaque;
599 fn decode_alloc_id(&mut self) -> interpret::AllocId {
600 let alloc_decoding_session = self.alloc_decoding_session;
601 alloc_decoding_session.decode_alloc_id(self)
605 rustc_middle::implement_ty_decoder!(CacheDecoder<'a, 'tcx>);
607 // This ensures that the `Decodable<opaque::Decoder>::decode` specialization for `Vec<u8>` is used
608 // when a `CacheDecoder` is passed to `Decodable::decode`. Unfortunately, we have to manually opt
609 // into specializations this way, given how `CacheDecoder` and the decoding traits currently work.
610 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for Vec<u8> {
611 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
612 Decodable::decode(&mut d.opaque)
616 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for SyntaxContext {
617 fn decode(decoder: &mut CacheDecoder<'a, 'tcx>) -> Self {
618 let syntax_contexts = decoder.syntax_contexts;
619 rustc_span::hygiene::decode_syntax_context(decoder, decoder.hygiene_context, |this, id| {
620 // This closure is invoked if we haven't already decoded the data for the `SyntaxContext` we are deserializing.
621 // We look up the position of the associated `SyntaxData` and decode it.
622 let pos = syntax_contexts.get(&id).unwrap();
623 this.with_position(pos.to_usize(), |decoder| {
624 let data: SyntaxContextData = decode_tagged(decoder, TAG_SYNTAX_CONTEXT);
631 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for ExpnId {
632 fn decode(decoder: &mut CacheDecoder<'a, 'tcx>) -> Self {
633 let hash = ExpnHash::decode(decoder);
635 return ExpnId::root();
638 if let Some(expn_id) = ExpnId::from_hash(hash) {
642 let krate = decoder.tcx.stable_crate_id_to_crate_num(hash.stable_crate_id());
644 let expn_id = if krate == LOCAL_CRATE {
645 // We look up the position of the associated `ExpnData` and decode it.
649 .unwrap_or_else(|| panic!("Bad hash {:?} (map {:?})", hash, decoder.expn_data));
651 let data: ExpnData = decoder
652 .with_position(pos.to_usize(), |decoder| decode_tagged(decoder, TAG_EXPN_DATA));
653 let expn_id = rustc_span::hygiene::register_local_expn_id(data, hash);
655 #[cfg(debug_assertions)]
657 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
658 let mut hcx = decoder.tcx.create_stable_hashing_context();
659 let mut hasher = StableHasher::new();
660 hcx.while_hashing_spans(true, |hcx| {
661 expn_id.expn_data().hash_stable(hcx, &mut hasher)
663 let local_hash: u64 = hasher.finish();
664 debug_assert_eq!(hash.local_hash(), local_hash);
669 let index_guess = decoder.foreign_expn_data[&hash];
670 decoder.tcx.cstore_untracked().expn_hash_to_expn_id(
678 debug_assert_eq!(expn_id.krate, krate);
683 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for Span {
684 fn decode(decoder: &mut CacheDecoder<'a, 'tcx>) -> Self {
685 let ctxt = SyntaxContext::decode(decoder);
686 let parent = Option::<LocalDefId>::decode(decoder);
687 let tag: u8 = Decodable::decode(decoder);
689 if tag == TAG_PARTIAL_SPAN {
690 return Span::new(BytePos(0), BytePos(0), ctxt, parent);
691 } else if tag == TAG_RELATIVE_SPAN {
692 let dlo = u32::decode(decoder);
693 let dto = u32::decode(decoder);
696 decoder.tcx.definitions_untracked().def_span(parent.unwrap()).data_untracked();
697 let span = Span::new(
698 enclosing.lo + BytePos::from_u32(dlo),
699 enclosing.lo + BytePos::from_u32(dto),
706 debug_assert_eq!(tag, TAG_FULL_SPAN);
709 let file_lo_index = SourceFileIndex::decode(decoder);
710 let line_lo = usize::decode(decoder);
711 let col_lo = BytePos::decode(decoder);
712 let len = BytePos::decode(decoder);
714 let file_lo = decoder.file_index_to_file(file_lo_index);
715 let lo = file_lo.lines[line_lo - 1] + col_lo;
718 Span::new(lo, hi, ctxt, parent)
722 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for CrateNum {
723 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
724 let stable_id = StableCrateId::decode(d);
725 let cnum = d.tcx.stable_crate_id_to_crate_num(stable_id);
730 // This impl makes sure that we get a runtime error when we try decode a
731 // `DefIndex` that is not contained in a `DefId`. Such a case would be problematic
732 // because we would not know how to transform the `DefIndex` to the current
734 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for DefIndex {
735 fn decode(_d: &mut CacheDecoder<'a, 'tcx>) -> DefIndex {
736 panic!("trying to decode `DefIndex` outside the context of a `DefId`")
740 // Both the `CrateNum` and the `DefIndex` of a `DefId` can change in between two
741 // compilation sessions. We use the `DefPathHash`, which is stable across
742 // sessions, to map the old `DefId` to the new one.
743 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for DefId {
744 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
745 // Load the `DefPathHash` which is was we encoded the `DefId` as.
746 let def_path_hash = DefPathHash::decode(d);
748 // Using the `DefPathHash`, we can lookup the new `DefId`.
749 // Subtle: We only encode a `DefId` as part of a query result.
750 // If we get to this point, then all of the query inputs were green,
751 // which means that the definition with this hash is guaranteed to
752 // still exist in the current compilation session.
753 d.tcx().def_path_hash_to_def_id(def_path_hash, &mut || {
754 panic!("Failed to convert DefPathHash {:?}", def_path_hash)
759 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx FxHashSet<LocalDefId> {
760 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
761 RefDecodable::decode(d)
765 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>>
766 for &'tcx IndexVec<mir::Promoted, mir::Body<'tcx>>
768 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
769 RefDecodable::decode(d)
773 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [thir::abstract_const::Node<'tcx>] {
774 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
775 RefDecodable::decode(d)
779 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [(ty::Predicate<'tcx>, Span)] {
780 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
781 RefDecodable::decode(d)
785 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [rustc_ast::InlineAsmTemplatePiece] {
786 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
787 RefDecodable::decode(d)
791 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [Span] {
792 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Self {
793 RefDecodable::decode(d)
797 //- ENCODING -------------------------------------------------------------------
799 pub trait OpaqueEncoder: Encoder {
800 fn position(&self) -> usize;
803 impl OpaqueEncoder for FileEncoder {
805 fn position(&self) -> usize {
806 FileEncoder::position(self)
810 /// An encoder that can write to the incremental compilation cache.
811 pub struct CacheEncoder<'a, 'tcx, E: OpaqueEncoder> {
814 type_shorthands: FxHashMap<Ty<'tcx>, usize>,
815 predicate_shorthands: FxHashMap<ty::PredicateKind<'tcx>, usize>,
816 interpret_allocs: FxIndexSet<interpret::AllocId>,
817 source_map: CachingSourceMapView<'tcx>,
818 file_to_file_index: FxHashMap<*const SourceFile, SourceFileIndex>,
819 hygiene_context: &'a HygieneEncodeContext,
822 impl<'a, 'tcx, E> CacheEncoder<'a, 'tcx, E>
824 E: 'a + OpaqueEncoder,
826 fn source_file_index(&mut self, source_file: Lrc<SourceFile>) -> SourceFileIndex {
827 self.file_to_file_index[&(&*source_file as *const SourceFile)]
830 /// Encode something with additional information that allows to do some
831 /// sanity checks when decoding the data again. This method will first
832 /// encode the specified tag, then the given value, then the number of
833 /// bytes taken up by tag and value. On decoding, we can then verify that
834 /// we get the expected tag and read the expected number of bytes.
835 fn encode_tagged<T: Encodable<Self>, V: Encodable<Self>>(
839 ) -> Result<(), E::Error> {
840 let start_pos = self.position();
845 let end_pos = self.position();
846 ((end_pos - start_pos) as u64).encode(self)
850 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for SyntaxContext
852 E: 'a + OpaqueEncoder,
854 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
855 rustc_span::hygiene::raw_encode_syntax_context(*self, s.hygiene_context, s)
859 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for ExpnId
861 E: 'a + OpaqueEncoder,
863 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
864 s.hygiene_context.schedule_expn_data_for_encoding(*self);
865 self.expn_hash().encode(s)
869 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for Span
871 E: 'a + OpaqueEncoder,
873 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
874 let span_data = self.data_untracked();
875 span_data.ctxt.encode(s)?;
876 span_data.parent.encode(s)?;
878 if span_data.is_dummy() {
879 return TAG_PARTIAL_SPAN.encode(s);
882 if let Some(parent) = span_data.parent {
883 let enclosing = s.tcx.definitions_untracked().def_span(parent).data_untracked();
884 if enclosing.contains(span_data) {
885 TAG_RELATIVE_SPAN.encode(s)?;
886 (span_data.lo - enclosing.lo).to_u32().encode(s)?;
887 (span_data.hi - enclosing.lo).to_u32().encode(s)?;
892 let pos = s.source_map.byte_pos_to_line_and_col(span_data.lo);
893 let partial_span = match &pos {
894 Some((file_lo, _, _)) => !file_lo.contains(span_data.hi),
899 return TAG_PARTIAL_SPAN.encode(s);
902 let (file_lo, line_lo, col_lo) = pos.unwrap();
904 let len = span_data.hi - span_data.lo;
906 let source_file_index = s.source_file_index(file_lo);
908 TAG_FULL_SPAN.encode(s)?;
909 source_file_index.encode(s)?;
916 impl<'a, 'tcx, E> TyEncoder<'tcx> for CacheEncoder<'a, 'tcx, E>
918 E: 'a + OpaqueEncoder,
920 const CLEAR_CROSS_CRATE: bool = false;
922 fn position(&self) -> usize {
923 self.encoder.position()
925 fn type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize> {
926 &mut self.type_shorthands
928 fn predicate_shorthands(&mut self) -> &mut FxHashMap<ty::PredicateKind<'tcx>, usize> {
929 &mut self.predicate_shorthands
931 fn encode_alloc_id(&mut self, alloc_id: &interpret::AllocId) -> Result<(), Self::Error> {
932 let (index, _) = self.interpret_allocs.insert_full(*alloc_id);
938 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for CrateNum
940 E: 'a + OpaqueEncoder,
942 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
943 s.tcx.stable_crate_id(*self).encode(s)
947 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for DefId
949 E: 'a + OpaqueEncoder,
951 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
952 s.tcx.def_path_hash(*self).encode(s)
956 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for DefIndex
958 E: 'a + OpaqueEncoder,
960 fn encode(&self, _: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
961 bug!("encoding `DefIndex` without context");
965 macro_rules! encoder_methods {
966 ($($name:ident($ty:ty);)*) => {
968 $(fn $name(&mut self, value: $ty) -> Result<(), Self::Error> {
969 self.encoder.$name(value)
974 impl<'a, 'tcx, E> Encoder for CacheEncoder<'a, 'tcx, E>
976 E: 'a + OpaqueEncoder,
978 type Error = E::Error;
981 fn emit_unit(&mut self) -> Result<(), Self::Error> {
1005 emit_raw_bytes(&[u8]);
1009 // This ensures that the `Encodable<opaque::FileEncoder>::encode` specialization for byte slices
1010 // is used when a `CacheEncoder` having an `opaque::FileEncoder` is passed to `Encodable::encode`.
1011 // Unfortunately, we have to manually opt into specializations this way, given how `CacheEncoder`
1012 // and the encoding traits currently work.
1013 impl<'a, 'tcx> Encodable<CacheEncoder<'a, 'tcx, FileEncoder>> for [u8] {
1014 fn encode(&self, e: &mut CacheEncoder<'a, 'tcx, FileEncoder>) -> FileEncodeResult {
1015 self.encode(e.encoder)
1019 pub fn encode_query_results<'a, 'tcx, CTX, Q>(
1021 encoder: &mut CacheEncoder<'a, 'tcx, FileEncoder>,
1022 query_result_index: &mut EncodedDepNodeIndex,
1023 ) -> FileEncodeResult
1025 CTX: QueryContext + 'tcx,
1026 Q: super::QueryDescription<CTX>,
1027 Q::Value: Encodable<CacheEncoder<'a, 'tcx, FileEncoder>>,
1032 .extra_verbose_generic_activity("encode_query_results_for", std::any::type_name::<Q>());
1034 assert!(Q::query_state(tcx).all_inactive());
1035 let cache = Q::query_cache(tcx);
1036 let mut res = Ok(());
1037 cache.iter_results(&mut |key, value, dep_node| {
1041 if Q::cache_on_disk(*tcx.dep_context(), &key) {
1042 let dep_node = SerializedDepNodeIndex::new(dep_node.index());
1044 // Record position of the cache entry.
1045 query_result_index.push((dep_node, AbsoluteBytePos::new(encoder.encoder.position())));
1047 // Encode the type check tables with the `SerializedDepNodeIndex`
1049 match encoder.encode_tagged(dep_node, value) {