1 use crate::dep_graph::{DepNode, DepNodeIndex, SerializedDepNodeIndex};
2 use crate::mir::interpret::{AllocDecodingSession, AllocDecodingState};
3 use crate::mir::{self, interpret};
4 use crate::ty::codec::{RefDecodable, TyDecoder, TyEncoder};
5 use crate::ty::context::TyCtxt;
6 use crate::ty::{self, Ty};
7 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
8 use rustc_data_structures::sync::{HashMapExt, Lock, Lrc, OnceCell};
9 use rustc_data_structures::thin_vec::ThinVec;
10 use rustc_data_structures::unhash::UnhashMap;
11 use rustc_errors::Diagnostic;
12 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, LOCAL_CRATE};
13 use rustc_hir::definitions::DefPathHash;
14 use rustc_hir::definitions::Definitions;
15 use rustc_index::vec::{Idx, IndexVec};
16 use rustc_query_system::dep_graph::DepContext;
17 use rustc_query_system::query::QueryContext;
18 use rustc_serialize::{
19 opaque::{self, FileEncodeResult, FileEncoder, IntEncodedWithFixedSize},
20 Decodable, Decoder, Encodable, Encoder,
22 use rustc_session::{CrateDisambiguator, Session};
23 use rustc_span::hygiene::{
24 ExpnDataDecodeMode, ExpnDataEncodeMode, ExpnId, HygieneDecodeContext, HygieneEncodeContext,
25 SyntaxContext, SyntaxContextData,
27 use rustc_span::source_map::{SourceMap, StableSourceFileId};
28 use rustc_span::CachingSourceMapView;
29 use rustc_span::{BytePos, ExpnData, SourceFile, Span, DUMMY_SP};
30 use std::collections::hash_map::Entry;
31 use std::iter::FromIterator;
34 const TAG_FILE_FOOTER: u128 = 0xC0FFEE_C0FFEE_C0FFEE_C0FFEE_C0FFEE;
36 // A normal span encoded with both location information and a `SyntaxContext`
37 const TAG_FULL_SPAN: u8 = 0;
38 // A partial span with no location information, encoded only with a `SyntaxContext`
39 const TAG_PARTIAL_SPAN: u8 = 1;
41 const TAG_SYNTAX_CONTEXT: u8 = 0;
42 const TAG_EXPN_DATA: u8 = 1;
44 /// Provides an interface to incremental compilation data cached from the
45 /// previous compilation session. This data will eventually include the results
46 /// of a few selected queries (like `typeck` and `mir_optimized`) and
47 /// any diagnostics that have been emitted during a query.
48 pub struct OnDiskCache<'sess> {
49 // The complete cache data in serialized form.
50 serialized_data: Vec<u8>,
52 // Collects all `Diagnostic`s emitted during the current compilation
54 current_diagnostics: Lock<FxHashMap<DepNodeIndex, Vec<Diagnostic>>>,
56 prev_cnums: Vec<(u32, String, CrateDisambiguator)>,
57 cnum_map: OnceCell<IndexVec<CrateNum, Option<CrateNum>>>,
59 source_map: &'sess SourceMap,
60 file_index_to_stable_id: FxHashMap<SourceFileIndex, StableSourceFileId>,
62 // Caches that are populated lazily during decoding.
63 file_index_to_file: Lock<FxHashMap<SourceFileIndex, Lrc<SourceFile>>>,
65 // A map from dep-node to the position of the cached query result in
67 query_result_index: FxHashMap<SerializedDepNodeIndex, AbsoluteBytePos>,
69 // A map from dep-node to the position of any associated diagnostics in
71 prev_diagnostics_index: FxHashMap<SerializedDepNodeIndex, AbsoluteBytePos>,
73 alloc_decoding_state: AllocDecodingState,
75 // A map from syntax context ids to the position of their associated
76 // `SyntaxContextData`. We use a `u32` instead of a `SyntaxContext`
77 // to represent the fact that we are storing *encoded* ids. When we decode
78 // a `SyntaxContext`, a new id will be allocated from the global `HygieneData`,
79 // which will almost certainly be different than the serialized id.
80 syntax_contexts: FxHashMap<u32, AbsoluteBytePos>,
81 // A map from the `DefPathHash` of an `ExpnId` to the position
82 // of their associated `ExpnData`. Ideally, we would store a `DefId`,
83 // but we need to decode this before we've constructed a `TyCtxt` (which
84 // makes it difficult to decode a `DefId`).
86 // Note that these `DefPathHashes` correspond to both local and foreign
87 // `ExpnData` (e.g `ExpnData.krate` may not be `LOCAL_CRATE`). Alternatively,
88 // we could look up the `ExpnData` from the metadata of foreign crates,
89 // but it seemed easier to have `OnDiskCache` be independent of the `CStore`.
90 expn_data: FxHashMap<u32, AbsoluteBytePos>,
91 // Additional information used when decoding hygiene data.
92 hygiene_context: HygieneDecodeContext,
93 // Maps `DefPathHash`es to their `RawDefId`s from the *previous*
94 // compilation session. This is used as an initial 'guess' when
95 // we try to map a `DefPathHash` to its `DefId` in the current compilation
97 foreign_def_path_hashes: UnhashMap<DefPathHash, RawDefId>,
99 // The *next* compilation sessison's `foreign_def_path_hashes` - at
100 // the end of our current compilation session, this will get written
101 // out to the `foreign_def_path_hashes` field of the `Footer`, which
102 // will become `foreign_def_path_hashes` of the next compilation session.
103 // This stores any `DefPathHash` that we may need to map to a `DefId`
104 // during the next compilation session.
105 latest_foreign_def_path_hashes: Lock<UnhashMap<DefPathHash, RawDefId>>,
107 // Maps `DefPathHashes` to their corresponding `LocalDefId`s for all
108 // local items in the current compilation session. This is only populated
109 // when we are in incremental mode and have loaded a pre-existing cache
110 // from disk, since this map is only used when deserializing a `DefPathHash`
111 // from the incremental cache.
112 local_def_path_hash_to_def_id: UnhashMap<DefPathHash, LocalDefId>,
113 // Caches all lookups of `DefPathHashes`, both for local and foreign
114 // definitions. A definition from the previous compilation session
115 // may no longer exist in the current compilation session, so
116 // we use `Option<DefId>` so that we can cache a lookup failure.
117 def_path_hash_to_def_id_cache: Lock<UnhashMap<DefPathHash, Option<DefId>>>,
120 // This type is used only for serialization and deserialization.
121 #[derive(Encodable, Decodable)]
123 file_index_to_stable_id: FxHashMap<SourceFileIndex, StableSourceFileId>,
124 prev_cnums: Vec<(u32, String, CrateDisambiguator)>,
125 query_result_index: EncodedQueryResultIndex,
126 diagnostics_index: EncodedQueryResultIndex,
127 // The location of all allocations.
128 interpret_alloc_index: Vec<u32>,
129 // See `OnDiskCache.syntax_contexts`
130 syntax_contexts: FxHashMap<u32, AbsoluteBytePos>,
131 // See `OnDiskCache.expn_data`
132 expn_data: FxHashMap<u32, AbsoluteBytePos>,
133 foreign_def_path_hashes: UnhashMap<DefPathHash, RawDefId>,
136 pub type EncodedQueryResultIndex = Vec<(SerializedDepNodeIndex, AbsoluteBytePos)>;
137 type EncodedDiagnosticsIndex = Vec<(SerializedDepNodeIndex, AbsoluteBytePos)>;
138 type EncodedDiagnostics = Vec<Diagnostic>;
140 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, Encodable, Decodable)]
141 struct SourceFileIndex(u32);
143 #[derive(Copy, Clone, Debug, Hash, Eq, PartialEq, Encodable, Decodable)]
144 pub struct AbsoluteBytePos(u32);
146 impl AbsoluteBytePos {
147 fn new(pos: usize) -> AbsoluteBytePos {
148 debug_assert!(pos <= u32::MAX as usize);
149 AbsoluteBytePos(pos as u32)
152 fn to_usize(self) -> usize {
157 /// Represents a potentially invalid `DefId`. This is used during incremental
158 /// compilation to represent a `DefId` from the *previous* compilation session,
159 /// which may no longer be valid. This is used to help map a `DefPathHash`
160 /// to a `DefId` in the current compilation session.
161 #[derive(Encodable, Decodable, Copy, Clone, Debug)]
162 crate struct RawDefId {
163 // We deliberately do not use `CrateNum` and `DefIndex`
164 // here, since a crate/index from the previous compilation
165 // session may no longer exist.
170 fn make_local_def_path_hash_map(definitions: &Definitions) -> UnhashMap<DefPathHash, LocalDefId> {
171 UnhashMap::from_iter(
174 .all_def_path_hashes_and_def_ids(LOCAL_CRATE)
175 .map(|(hash, def_id)| (hash, def_id.as_local().unwrap())),
179 impl<'sess> OnDiskCache<'sess> {
180 /// Creates a new `OnDiskCache` instance from the serialized data in `data`.
182 sess: &'sess Session,
185 definitions: &Definitions,
187 debug_assert!(sess.opts.incremental.is_some());
189 // Wrap in a scope so we can borrow `data`.
190 let footer: Footer = {
191 let mut decoder = opaque::Decoder::new(&data[..], start_pos);
193 // Decode the *position* of the footer, which can be found in the
194 // last 8 bytes of the file.
195 decoder.set_position(data.len() - IntEncodedWithFixedSize::ENCODED_SIZE);
196 let footer_pos = IntEncodedWithFixedSize::decode(&mut decoder)
197 .expect("error while trying to decode footer position")
200 // Decode the file footer, which contains all the lookup tables, etc.
201 decoder.set_position(footer_pos);
203 decode_tagged(&mut decoder, TAG_FILE_FOOTER)
204 .expect("error while trying to decode footer position")
208 serialized_data: data,
209 file_index_to_stable_id: footer.file_index_to_stable_id,
210 file_index_to_file: Default::default(),
211 prev_cnums: footer.prev_cnums,
212 cnum_map: OnceCell::new(),
213 source_map: sess.source_map(),
214 current_diagnostics: Default::default(),
215 query_result_index: footer.query_result_index.into_iter().collect(),
216 prev_diagnostics_index: footer.diagnostics_index.into_iter().collect(),
217 alloc_decoding_state: AllocDecodingState::new(footer.interpret_alloc_index),
218 syntax_contexts: footer.syntax_contexts,
219 expn_data: footer.expn_data,
220 hygiene_context: Default::default(),
221 foreign_def_path_hashes: footer.foreign_def_path_hashes,
222 latest_foreign_def_path_hashes: Default::default(),
223 local_def_path_hash_to_def_id: make_local_def_path_hash_map(definitions),
224 def_path_hash_to_def_id_cache: Default::default(),
228 pub fn new_empty(source_map: &'sess SourceMap) -> Self {
230 serialized_data: Vec::new(),
231 file_index_to_stable_id: Default::default(),
232 file_index_to_file: Default::default(),
234 cnum_map: OnceCell::new(),
236 current_diagnostics: Default::default(),
237 query_result_index: Default::default(),
238 prev_diagnostics_index: Default::default(),
239 alloc_decoding_state: AllocDecodingState::new(Vec::new()),
240 syntax_contexts: FxHashMap::default(),
241 expn_data: FxHashMap::default(),
242 hygiene_context: Default::default(),
243 foreign_def_path_hashes: Default::default(),
244 latest_foreign_def_path_hashes: Default::default(),
245 local_def_path_hash_to_def_id: Default::default(),
246 def_path_hash_to_def_id_cache: Default::default(),
250 pub fn serialize<'tcx>(
253 encoder: &mut FileEncoder,
254 ) -> FileEncodeResult {
255 // Serializing the `DepGraph` should not modify it.
256 tcx.dep_graph.with_ignore(|| {
257 // Allocate `SourceFileIndex`es.
258 let (file_to_file_index, file_index_to_stable_id) = {
259 let files = tcx.sess.source_map().files();
260 let mut file_to_file_index =
261 FxHashMap::with_capacity_and_hasher(files.len(), Default::default());
262 let mut file_index_to_stable_id =
263 FxHashMap::with_capacity_and_hasher(files.len(), Default::default());
265 for (index, file) in files.iter().enumerate() {
266 let index = SourceFileIndex(index as u32);
267 let file_ptr: *const SourceFile = &**file as *const _;
268 file_to_file_index.insert(file_ptr, index);
269 file_index_to_stable_id.insert(index, StableSourceFileId::new(&file));
272 (file_to_file_index, file_index_to_stable_id)
275 // Register any dep nodes that we reused from the previous session,
276 // but didn't `DepNode::construct` in this session. This ensures
277 // that their `DefPathHash` to `RawDefId` mappings are registered
278 // in 'latest_foreign_def_path_hashes' if necessary, since that
279 // normally happens in `DepNode::construct`.
280 tcx.dep_graph.register_reused_dep_nodes(tcx);
282 // Load everything into memory so we can write it out to the on-disk
283 // cache. The vast majority of cacheable query results should already
284 // be in memory, so this should be a cheap operation.
285 // Do this *before* we clone 'latest_foreign_def_path_hashes', since
286 // loading existing queries may cause us to create new DepNodes, which
287 // may in turn end up invoking `store_foreign_def_id_hash`
288 tcx.queries.exec_cache_promotions(tcx);
290 let latest_foreign_def_path_hashes = self.latest_foreign_def_path_hashes.lock().clone();
291 let hygiene_encode_context = HygieneEncodeContext::default();
293 let mut encoder = CacheEncoder {
296 type_shorthands: Default::default(),
297 predicate_shorthands: Default::default(),
298 interpret_allocs: Default::default(),
299 source_map: CachingSourceMapView::new(tcx.sess.source_map()),
301 hygiene_context: &hygiene_encode_context,
302 latest_foreign_def_path_hashes,
305 // Encode query results.
306 let mut query_result_index = EncodedQueryResultIndex::new();
308 tcx.sess.time("encode_query_results", || -> FileEncodeResult {
309 let enc = &mut encoder;
310 let qri = &mut query_result_index;
311 tcx.queries.encode_query_results(tcx, enc, qri)
314 // Encode diagnostics.
315 let diagnostics_index: EncodedDiagnosticsIndex = self
320 |(dep_node_index, diagnostics)| -> Result<_, <FileEncoder as Encoder>::Error> {
321 let pos = AbsoluteBytePos::new(encoder.position());
322 // Let's make sure we get the expected type here.
323 let diagnostics: &EncodedDiagnostics = diagnostics;
324 let dep_node_index = SerializedDepNodeIndex::new(dep_node_index.index());
325 encoder.encode_tagged(dep_node_index, diagnostics)?;
327 Ok((dep_node_index, pos))
330 .collect::<Result<_, _>>()?;
332 let interpret_alloc_index = {
333 let mut interpret_alloc_index = Vec::new();
336 let new_n = encoder.interpret_allocs.len();
337 // If we have found new IDs, serialize those too.
342 interpret_alloc_index.reserve(new_n - n);
343 for idx in n..new_n {
344 let id = encoder.interpret_allocs[idx];
345 let pos = encoder.position() as u32;
346 interpret_alloc_index.push(pos);
347 interpret::specialized_encode_alloc_id(&mut encoder, tcx, id)?;
351 interpret_alloc_index
354 let sorted_cnums = sorted_cnums_including_local_crate(tcx);
355 let prev_cnums: Vec<_> = sorted_cnums
358 let crate_name = tcx.original_crate_name(cnum).to_string();
359 let crate_disambiguator = tcx.crate_disambiguator(cnum);
360 (cnum.as_u32(), crate_name, crate_disambiguator)
364 let mut syntax_contexts = FxHashMap::default();
365 let mut expn_ids = FxHashMap::default();
367 // Encode all hygiene data (`SyntaxContextData` and `ExpnData`) from the current
370 hygiene_encode_context.encode(
372 |encoder, index, ctxt_data| -> FileEncodeResult {
373 let pos = AbsoluteBytePos::new(encoder.position());
374 encoder.encode_tagged(TAG_SYNTAX_CONTEXT, ctxt_data)?;
375 syntax_contexts.insert(index, pos);
378 |encoder, index, expn_data| -> FileEncodeResult {
379 let pos = AbsoluteBytePos::new(encoder.position());
380 encoder.encode_tagged(TAG_EXPN_DATA, expn_data)?;
381 expn_ids.insert(index, pos);
386 let foreign_def_path_hashes =
387 std::mem::take(&mut encoder.latest_foreign_def_path_hashes);
389 // `Encode the file footer.
390 let footer_pos = encoder.position() as u64;
391 encoder.encode_tagged(
394 file_index_to_stable_id,
398 interpret_alloc_index,
401 foreign_def_path_hashes,
405 // Encode the position of the footer as the last 8 bytes of the
406 // file so we know where to look for it.
407 IntEncodedWithFixedSize(footer_pos).encode(encoder.encoder)?;
409 // DO NOT WRITE ANYTHING TO THE ENCODER AFTER THIS POINT! The address
410 // of the footer must be the last thing in the data stream.
414 fn sorted_cnums_including_local_crate(tcx: TyCtxt<'_>) -> Vec<CrateNum> {
415 let mut cnums = vec![LOCAL_CRATE];
416 cnums.extend_from_slice(tcx.crates());
417 cnums.sort_unstable();
418 // Just to be sure...
425 /// Loads a diagnostic emitted during the previous compilation session.
426 pub fn load_diagnostics(
429 dep_node_index: SerializedDepNodeIndex,
430 ) -> Vec<Diagnostic> {
431 let diagnostics: Option<EncodedDiagnostics> =
432 self.load_indexed(tcx, dep_node_index, &self.prev_diagnostics_index, "diagnostics");
434 diagnostics.unwrap_or_default()
437 /// Stores a diagnostic emitted during the current compilation session.
438 /// Anything stored like this will be available via `load_diagnostics` in
439 /// the next compilation session.
442 pub fn store_diagnostics(
444 dep_node_index: DepNodeIndex,
445 diagnostics: ThinVec<Diagnostic>,
447 let mut current_diagnostics = self.current_diagnostics.borrow_mut();
448 let prev = current_diagnostics.insert(dep_node_index, diagnostics.into());
449 debug_assert!(prev.is_none());
452 fn get_raw_def_id(&self, hash: &DefPathHash) -> Option<RawDefId> {
453 self.foreign_def_path_hashes.get(hash).copied()
456 fn try_remap_cnum(&self, tcx: TyCtxt<'_>, cnum: u32) -> Option<CrateNum> {
458 self.cnum_map.get_or_init(|| Self::compute_cnum_map(tcx, &self.prev_cnums[..]));
459 debug!("try_remap_cnum({}): cnum_map={:?}", cnum, cnum_map);
461 cnum_map[CrateNum::from_u32(cnum)]
464 pub(crate) fn store_foreign_def_id_hash(&self, def_id: DefId, hash: DefPathHash) {
465 // We may overwrite an existing entry, but it will have the same value,
467 self.latest_foreign_def_path_hashes
469 .insert(hash, RawDefId { krate: def_id.krate.as_u32(), index: def_id.index.as_u32() });
472 /// If the given `dep_node`'s hash still exists in the current compilation,
473 /// and its current `DefId` is foreign, calls `store_foreign_def_id` with it.
475 /// Normally, `store_foreign_def_id_hash` can be called directly by
476 /// the dependency graph when we construct a `DepNode`. However,
477 /// when we re-use a deserialized `DepNode` from the previous compilation
478 /// session, we only have the `DefPathHash` available. This method is used
479 /// to that any `DepNode` that we re-use has a `DefPathHash` -> `RawId` written
480 /// out for usage in the next compilation session.
481 pub fn register_reused_dep_node(&self, tcx: TyCtxt<'tcx>, dep_node: &DepNode) {
482 // For reused dep nodes, we only need to store the mapping if the node
483 // is one whose query key we can reconstruct from the hash. We use the
484 // mapping to aid that reconstruction in the next session. While we also
485 // use it to decode `DefId`s we encoded in the cache as `DefPathHashes`,
486 // they're already registered during `DefId` encoding.
487 if dep_node.kind.can_reconstruct_query_key() {
488 let hash = DefPathHash(dep_node.hash.into());
490 // We can't simply copy the `RawDefId` from `foreign_def_path_hashes` to
491 // `latest_foreign_def_path_hashes`, since the `RawDefId` might have
492 // changed in the current compilation session (e.g. we've added/removed crates,
493 // or added/removed definitions before/after the target definition).
494 if let Some(def_id) = self.def_path_hash_to_def_id(tcx, hash) {
495 if !def_id.is_local() {
496 self.store_foreign_def_id_hash(def_id, hash);
502 /// Returns the cached query result if there is something in the cache for
503 /// the given `SerializedDepNodeIndex`; otherwise returns `None`.
504 pub fn try_load_query_result<'tcx, T>(
507 dep_node_index: SerializedDepNodeIndex,
510 T: for<'a> Decodable<CacheDecoder<'a, 'tcx>>,
512 self.load_indexed(tcx, dep_node_index, &self.query_result_index, "query result")
515 /// Stores a diagnostic emitted during computation of an anonymous query.
516 /// Since many anonymous queries can share the same `DepNode`, we aggregate
517 /// them -- as opposed to regular queries where we assume that there is a
518 /// 1:1 relationship between query-key and `DepNode`.
521 pub fn store_diagnostics_for_anon_node(
523 dep_node_index: DepNodeIndex,
524 diagnostics: ThinVec<Diagnostic>,
526 let mut current_diagnostics = self.current_diagnostics.borrow_mut();
528 let x = current_diagnostics.entry(dep_node_index).or_default();
530 x.extend(Into::<Vec<_>>::into(diagnostics));
533 fn load_indexed<'tcx, T>(
536 dep_node_index: SerializedDepNodeIndex,
537 index: &FxHashMap<SerializedDepNodeIndex, AbsoluteBytePos>,
538 debug_tag: &'static str,
541 T: for<'a> Decodable<CacheDecoder<'a, 'tcx>>,
543 let pos = index.get(&dep_node_index).cloned()?;
545 self.with_decoder(tcx, pos, |decoder| match decode_tagged(decoder, dep_node_index) {
547 Err(e) => bug!("could not decode cached {}: {}", debug_tag, e),
551 fn with_decoder<'a, 'tcx, T, F: FnOnce(&mut CacheDecoder<'sess, 'tcx>) -> T>(
554 pos: AbsoluteBytePos,
558 T: Decodable<CacheDecoder<'a, 'tcx>>,
561 self.cnum_map.get_or_init(|| Self::compute_cnum_map(tcx, &self.prev_cnums[..]));
563 let mut decoder = CacheDecoder {
565 opaque: opaque::Decoder::new(&self.serialized_data[..], pos.to_usize()),
566 source_map: self.source_map,
568 file_index_to_file: &self.file_index_to_file,
569 file_index_to_stable_id: &self.file_index_to_stable_id,
570 alloc_decoding_session: self.alloc_decoding_state.new_decoding_session(),
571 syntax_contexts: &self.syntax_contexts,
572 expn_data: &self.expn_data,
573 hygiene_context: &self.hygiene_context,
578 // This function builds mapping from previous-session-`CrateNum` to
579 // current-session-`CrateNum`. There might be `CrateNum`s from the previous
580 // `Session` that don't occur in the current one. For these, the mapping
584 prev_cnums: &[(u32, String, CrateDisambiguator)],
585 ) -> IndexVec<CrateNum, Option<CrateNum>> {
586 tcx.dep_graph.with_ignore(|| {
587 let current_cnums = tcx
588 .all_crate_nums(LOCAL_CRATE)
591 let crate_name = tcx.original_crate_name(cnum).to_string();
592 let crate_disambiguator = tcx.crate_disambiguator(cnum);
593 ((crate_name, crate_disambiguator), cnum)
595 .collect::<FxHashMap<_, _>>();
597 let map_size = prev_cnums.iter().map(|&(cnum, ..)| cnum).max().unwrap_or(0) + 1;
598 let mut map = IndexVec::from_elem_n(None, map_size as usize);
600 for &(prev_cnum, ref crate_name, crate_disambiguator) in prev_cnums {
601 let key = (crate_name.clone(), crate_disambiguator);
602 map[CrateNum::from_u32(prev_cnum)] = current_cnums.get(&key).cloned();
605 map[LOCAL_CRATE] = Some(LOCAL_CRATE);
610 /// Converts a `DefPathHash` to its corresponding `DefId` in the current compilation
611 /// session, if it still exists. This is used during incremental compilation to
612 /// turn a deserialized `DefPathHash` into its current `DefId`.
613 pub(crate) fn def_path_hash_to_def_id(
618 let mut cache = self.def_path_hash_to_def_id_cache.lock();
619 match cache.entry(hash) {
620 Entry::Occupied(e) => *e.get(),
621 Entry::Vacant(e) => {
622 debug!("def_path_hash_to_def_id({:?})", hash);
623 // Check if the `DefPathHash` corresponds to a definition in the current
625 if let Some(def_id) = self.local_def_path_hash_to_def_id.get(&hash).cloned() {
626 let def_id = def_id.to_def_id();
627 e.insert(Some(def_id));
630 // This `raw_def_id` represents the `DefId` of this `DefPathHash` in
631 // the *previous* compliation session. The `DefPathHash` includes the
632 // owning crate, so if the corresponding definition still exists in the
633 // current compilation session, the crate is guaranteed to be the same
634 // (otherwise, we would compute a different `DefPathHash`).
635 let raw_def_id = self.get_raw_def_id(&hash)?;
636 debug!("def_path_hash_to_def_id({:?}): raw_def_id = {:?}", hash, raw_def_id);
637 // If the owning crate no longer exists, the corresponding definition definitely
639 let krate = self.try_remap_cnum(tcx, raw_def_id.krate)?;
640 debug!("def_path_hash_to_def_id({:?}): krate = {:?}", hash, krate);
641 // If our `DefPathHash` corresponded to a definition in the local crate,
642 // we should have either found it in `local_def_path_hash_to_def_id`, or
643 // never attempted to load it in the first place. Any query result or `DepNode`
644 // that references a local `DefId` should depend on some HIR-related `DepNode`.
645 // If a local definition is removed/modified such that its old `DefPathHash`
646 // no longer has a corresponding definition, that HIR-related `DepNode` should
647 // end up red. This should prevent us from ever calling
648 // `tcx.def_path_hash_to_def_id`, since we'll end up recomputing any
650 debug_assert_ne!(krate, LOCAL_CRATE);
651 // Try to find a definition in the current session, using the previous `DefIndex`
652 // as an initial guess.
653 let opt_def_id = tcx.cstore.def_path_hash_to_def_id(krate, raw_def_id.index, hash);
654 debug!("def_path_to_def_id({:?}): opt_def_id = {:?}", hash, opt_def_id);
655 e.insert(opt_def_id);
662 //- DECODING -------------------------------------------------------------------
664 /// A decoder that can read from the incremental compilation cache. It is similar to the one
665 /// we use for crate metadata decoding in that it can rebase spans and eventually
666 /// will also handle things that contain `Ty` instances.
667 pub struct CacheDecoder<'a, 'tcx> {
669 opaque: opaque::Decoder<'a>,
670 source_map: &'a SourceMap,
671 cnum_map: &'a IndexVec<CrateNum, Option<CrateNum>>,
672 file_index_to_file: &'a Lock<FxHashMap<SourceFileIndex, Lrc<SourceFile>>>,
673 file_index_to_stable_id: &'a FxHashMap<SourceFileIndex, StableSourceFileId>,
674 alloc_decoding_session: AllocDecodingSession<'a>,
675 syntax_contexts: &'a FxHashMap<u32, AbsoluteBytePos>,
676 expn_data: &'a FxHashMap<u32, AbsoluteBytePos>,
677 hygiene_context: &'a HygieneDecodeContext,
680 impl<'a, 'tcx> CacheDecoder<'a, 'tcx> {
681 fn file_index_to_file(&self, index: SourceFileIndex) -> Lrc<SourceFile> {
683 ref file_index_to_file,
684 ref file_index_to_stable_id,
693 let stable_id = file_index_to_stable_id[&index];
695 .source_file_by_stable_id(stable_id)
696 .expect("failed to lookup `SourceFile` in new context")
702 trait DecoderWithPosition: Decoder {
703 fn position(&self) -> usize;
706 impl<'a> DecoderWithPosition for opaque::Decoder<'a> {
707 fn position(&self) -> usize {
712 impl<'a, 'tcx> DecoderWithPosition for CacheDecoder<'a, 'tcx> {
713 fn position(&self) -> usize {
714 self.opaque.position()
718 // Decodes something that was encoded with `encode_tagged()` and verify that the
719 // tag matches and the correct amount of bytes was read.
720 fn decode_tagged<D, T, V>(decoder: &mut D, expected_tag: T) -> Result<V, D::Error>
722 T: Decodable<D> + Eq + std::fmt::Debug,
724 D: DecoderWithPosition,
726 let start_pos = decoder.position();
728 let actual_tag = T::decode(decoder)?;
729 assert_eq!(actual_tag, expected_tag);
730 let value = V::decode(decoder)?;
731 let end_pos = decoder.position();
733 let expected_len: u64 = Decodable::decode(decoder)?;
734 assert_eq!((end_pos - start_pos) as u64, expected_len);
739 impl<'a, 'tcx> TyDecoder<'tcx> for CacheDecoder<'a, 'tcx> {
740 const CLEAR_CROSS_CRATE: bool = false;
743 fn tcx(&self) -> TyCtxt<'tcx> {
748 fn position(&self) -> usize {
749 self.opaque.position()
753 fn peek_byte(&self) -> u8 {
754 self.opaque.data[self.opaque.position()]
757 fn cached_ty_for_shorthand<F>(
761 ) -> Result<Ty<'tcx>, Self::Error>
763 F: FnOnce(&mut Self) -> Result<Ty<'tcx>, Self::Error>,
765 let tcx = self.tcx();
768 ty::CReaderCacheKey { cnum: CrateNum::ReservedForIncrCompCache, pos: shorthand };
770 if let Some(&ty) = tcx.ty_rcache.borrow().get(&cache_key) {
774 let ty = or_insert_with(self)?;
775 // This may overwrite the entry, but it should overwrite with the same value.
776 tcx.ty_rcache.borrow_mut().insert_same(cache_key, ty);
780 fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
782 F: FnOnce(&mut Self) -> R,
784 debug_assert!(pos < self.opaque.data.len());
786 let new_opaque = opaque::Decoder::new(self.opaque.data, pos);
787 let old_opaque = mem::replace(&mut self.opaque, new_opaque);
789 self.opaque = old_opaque;
793 fn map_encoded_cnum_to_current(&self, cnum: CrateNum) -> CrateNum {
794 self.cnum_map[cnum].unwrap_or_else(|| bug!("could not find new `CrateNum` for {:?}", cnum))
797 fn decode_alloc_id(&mut self) -> Result<interpret::AllocId, Self::Error> {
798 let alloc_decoding_session = self.alloc_decoding_session;
799 alloc_decoding_session.decode_alloc_id(self)
803 crate::implement_ty_decoder!(CacheDecoder<'a, 'tcx>);
805 // This ensures that the `Decodable<opaque::Decoder>::decode` specialization for `Vec<u8>` is used
806 // when a `CacheDecoder` is passed to `Decodable::decode`. Unfortunately, we have to manually opt
807 // into specializations this way, given how `CacheDecoder` and the decoding traits currently work.
808 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for Vec<u8> {
809 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
810 Decodable::decode(&mut d.opaque)
814 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for SyntaxContext {
815 fn decode(decoder: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
816 let syntax_contexts = decoder.syntax_contexts;
817 rustc_span::hygiene::decode_syntax_context(decoder, decoder.hygiene_context, |this, id| {
818 // This closure is invoked if we haven't already decoded the data for the `SyntaxContext` we are deserializing.
819 // We look up the position of the associated `SyntaxData` and decode it.
820 let pos = syntax_contexts.get(&id).unwrap();
821 this.with_position(pos.to_usize(), |decoder| {
822 let data: SyntaxContextData = decode_tagged(decoder, TAG_SYNTAX_CONTEXT)?;
829 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for ExpnId {
830 fn decode(decoder: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
831 let expn_data = decoder.expn_data;
832 rustc_span::hygiene::decode_expn_id(
834 ExpnDataDecodeMode::incr_comp(decoder.hygiene_context),
836 // This closure is invoked if we haven't already decoded the data for the `ExpnId` we are deserializing.
837 // We look up the position of the associated `ExpnData` and decode it.
840 .unwrap_or_else(|| panic!("Bad index {:?} (map {:?})", index, expn_data));
842 this.with_position(pos.to_usize(), |decoder| {
843 let data: ExpnData = decode_tagged(decoder, TAG_EXPN_DATA)?;
851 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for Span {
852 fn decode(decoder: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
853 let tag: u8 = Decodable::decode(decoder)?;
855 if tag == TAG_PARTIAL_SPAN {
856 let ctxt = SyntaxContext::decode(decoder)?;
857 return Ok(DUMMY_SP.with_ctxt(ctxt));
859 debug_assert_eq!(tag, TAG_FULL_SPAN);
862 let file_lo_index = SourceFileIndex::decode(decoder)?;
863 let line_lo = usize::decode(decoder)?;
864 let col_lo = BytePos::decode(decoder)?;
865 let len = BytePos::decode(decoder)?;
866 let ctxt = SyntaxContext::decode(decoder)?;
868 let file_lo = decoder.file_index_to_file(file_lo_index);
869 let lo = file_lo.lines[line_lo - 1] + col_lo;
872 Ok(Span::new(lo, hi, ctxt))
876 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for CrateNum {
877 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
878 let cnum = CrateNum::from_u32(u32::decode(d)?);
879 Ok(d.map_encoded_cnum_to_current(cnum))
883 // This impl makes sure that we get a runtime error when we try decode a
884 // `DefIndex` that is not contained in a `DefId`. Such a case would be problematic
885 // because we would not know how to transform the `DefIndex` to the current
887 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for DefIndex {
888 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<DefIndex, String> {
889 Err(d.error("trying to decode `DefIndex` outside the context of a `DefId`"))
893 // Both the `CrateNum` and the `DefIndex` of a `DefId` can change in between two
894 // compilation sessions. We use the `DefPathHash`, which is stable across
895 // sessions, to map the old `DefId` to the new one.
896 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for DefId {
897 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
898 // Load the `DefPathHash` which is was we encoded the `DefId` as.
899 let def_path_hash = DefPathHash::decode(d)?;
901 // Using the `DefPathHash`, we can lookup the new `DefId`.
902 // Subtle: We only encode a `DefId` as part of a query result.
903 // If we get to this point, then all of the query inputs were green,
904 // which means that the definition with this hash is guaranteed to
905 // still exist in the current compilation session.
910 .def_path_hash_to_def_id(d.tcx(), def_path_hash)
915 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx FxHashSet<LocalDefId> {
916 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
917 RefDecodable::decode(d)
921 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>>
922 for &'tcx IndexVec<mir::Promoted, mir::Body<'tcx>>
924 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
925 RefDecodable::decode(d)
929 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [mir::abstract_const::Node<'tcx>] {
930 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
931 RefDecodable::decode(d)
935 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [(ty::Predicate<'tcx>, Span)] {
936 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
937 RefDecodable::decode(d)
941 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [rustc_ast::InlineAsmTemplatePiece] {
942 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
943 RefDecodable::decode(d)
947 impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx [Span] {
948 fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
949 RefDecodable::decode(d)
953 //- ENCODING -------------------------------------------------------------------
955 pub trait OpaqueEncoder: Encoder {
956 fn position(&self) -> usize;
959 impl OpaqueEncoder for FileEncoder {
961 fn position(&self) -> usize {
962 FileEncoder::position(self)
966 /// An encoder that can write to the incremental compilation cache.
967 pub struct CacheEncoder<'a, 'tcx, E: OpaqueEncoder> {
970 type_shorthands: FxHashMap<Ty<'tcx>, usize>,
971 predicate_shorthands: FxHashMap<ty::PredicateKind<'tcx>, usize>,
972 interpret_allocs: FxIndexSet<interpret::AllocId>,
973 source_map: CachingSourceMapView<'tcx>,
974 file_to_file_index: FxHashMap<*const SourceFile, SourceFileIndex>,
975 hygiene_context: &'a HygieneEncodeContext,
976 latest_foreign_def_path_hashes: UnhashMap<DefPathHash, RawDefId>,
979 impl<'a, 'tcx, E> CacheEncoder<'a, 'tcx, E>
981 E: 'a + OpaqueEncoder,
983 fn source_file_index(&mut self, source_file: Lrc<SourceFile>) -> SourceFileIndex {
984 self.file_to_file_index[&(&*source_file as *const SourceFile)]
987 /// Encode something with additional information that allows to do some
988 /// sanity checks when decoding the data again. This method will first
989 /// encode the specified tag, then the given value, then the number of
990 /// bytes taken up by tag and value. On decoding, we can then verify that
991 /// we get the expected tag and read the expected number of bytes.
992 fn encode_tagged<T: Encodable<Self>, V: Encodable<Self>>(
996 ) -> Result<(), E::Error> {
997 let start_pos = self.position();
1000 value.encode(self)?;
1002 let end_pos = self.position();
1003 ((end_pos - start_pos) as u64).encode(self)
1007 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for SyntaxContext
1009 E: 'a + OpaqueEncoder,
1011 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
1012 rustc_span::hygiene::raw_encode_syntax_context(*self, s.hygiene_context, s)
1016 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for ExpnId
1018 E: 'a + OpaqueEncoder,
1020 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
1021 rustc_span::hygiene::raw_encode_expn_id(
1024 ExpnDataEncodeMode::IncrComp,
1030 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for Span
1032 E: 'a + OpaqueEncoder,
1034 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
1035 let span_data = self.data();
1036 if self.is_dummy() {
1037 TAG_PARTIAL_SPAN.encode(s)?;
1038 return span_data.ctxt.encode(s);
1041 let pos = s.source_map.byte_pos_to_line_and_col(span_data.lo);
1042 let partial_span = match &pos {
1043 Some((file_lo, _, _)) => !file_lo.contains(span_data.hi),
1048 TAG_PARTIAL_SPAN.encode(s)?;
1049 return span_data.ctxt.encode(s);
1052 let (file_lo, line_lo, col_lo) = pos.unwrap();
1054 let len = span_data.hi - span_data.lo;
1056 let source_file_index = s.source_file_index(file_lo);
1058 TAG_FULL_SPAN.encode(s)?;
1059 source_file_index.encode(s)?;
1063 span_data.ctxt.encode(s)
1067 impl<'a, 'tcx, E> TyEncoder<'tcx> for CacheEncoder<'a, 'tcx, E>
1069 E: 'a + OpaqueEncoder,
1071 const CLEAR_CROSS_CRATE: bool = false;
1073 fn position(&self) -> usize {
1074 self.encoder.position()
1076 fn type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize> {
1077 &mut self.type_shorthands
1079 fn predicate_shorthands(&mut self) -> &mut FxHashMap<ty::PredicateKind<'tcx>, usize> {
1080 &mut self.predicate_shorthands
1082 fn encode_alloc_id(&mut self, alloc_id: &interpret::AllocId) -> Result<(), Self::Error> {
1083 let (index, _) = self.interpret_allocs.insert_full(*alloc_id);
1089 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for DefId
1091 E: 'a + OpaqueEncoder,
1093 fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
1094 let def_path_hash = s.tcx.def_path_hash(*self);
1095 // Store additional information when we encode a foreign `DefId`,
1096 // so that we can map its `DefPathHash` back to a `DefId` in the next
1097 // compilation session.
1098 if !self.is_local() {
1099 s.latest_foreign_def_path_hashes.insert(
1101 RawDefId { krate: self.krate.as_u32(), index: self.index.as_u32() },
1104 def_path_hash.encode(s)
1108 impl<'a, 'tcx, E> Encodable<CacheEncoder<'a, 'tcx, E>> for DefIndex
1110 E: 'a + OpaqueEncoder,
1112 fn encode(&self, _: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
1113 bug!("encoding `DefIndex` without context");
1117 macro_rules! encoder_methods {
1118 ($($name:ident($ty:ty);)*) => {
1120 $(fn $name(&mut self, value: $ty) -> Result<(), Self::Error> {
1121 self.encoder.$name(value)
1126 impl<'a, 'tcx, E> Encoder for CacheEncoder<'a, 'tcx, E>
1128 E: 'a + OpaqueEncoder,
1130 type Error = E::Error;
1133 fn emit_unit(&mut self) -> Result<(), Self::Error> {
1157 emit_raw_bytes(&[u8]);
1161 // This ensures that the `Encodable<opaque::FileEncoder>::encode` specialization for byte slices
1162 // is used when a `CacheEncoder` having an `opaque::FileEncoder` is passed to `Encodable::encode`.
1163 // Unfortunately, we have to manually opt into specializations this way, given how `CacheEncoder`
1164 // and the encoding traits currently work.
1165 impl<'a, 'tcx> Encodable<CacheEncoder<'a, 'tcx, FileEncoder>> for [u8] {
1166 fn encode(&self, e: &mut CacheEncoder<'a, 'tcx, FileEncoder>) -> FileEncodeResult {
1167 self.encode(e.encoder)
1171 pub fn encode_query_results<'a, 'tcx, CTX, Q>(
1173 encoder: &mut CacheEncoder<'a, 'tcx, FileEncoder>,
1174 query_result_index: &mut EncodedQueryResultIndex,
1175 ) -> FileEncodeResult
1177 CTX: QueryContext + 'tcx,
1178 Q: super::QueryDescription<CTX> + super::QueryAccessors<CTX>,
1179 Q::Value: Encodable<CacheEncoder<'a, 'tcx, FileEncoder>>,
1184 .extra_verbose_generic_activity("encode_query_results_for", std::any::type_name::<Q>());
1186 assert!(Q::query_state(tcx).all_inactive());
1187 let cache = Q::query_cache(tcx);
1188 let mut res = Ok(());
1189 cache.iter_results(&mut |key, value, dep_node| {
1193 if Q::cache_on_disk(tcx, &key, Some(value)) {
1194 let dep_node = SerializedDepNodeIndex::new(dep_node.index());
1196 // Record position of the cache entry.
1197 query_result_index.push((dep_node, AbsoluteBytePos::new(encoder.encoder.position())));
1199 // Encode the type check tables with the `SerializedDepNodeIndex`
1201 match encoder.encode_tagged(dep_node, value) {