1 use crate::errors::{FailCreateFileEncoder, FailSeekFile, FailWriteFile};
2 use crate::rmeta::def_path_hash_map::DefPathHashMapRef;
3 use crate::rmeta::table::TableBuilder;
6 use rustc_ast::util::comments;
7 use rustc_ast::Attribute;
8 use rustc_data_structures::fingerprint::Fingerprint;
9 use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
10 use rustc_data_structures::memmap::{Mmap, MmapMut};
11 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
12 use rustc_data_structures::sync::{join, par_iter, Lrc, ParallelIterator};
13 use rustc_data_structures::temp_dir::MaybeTempDir;
15 use rustc_hir::def::DefKind;
16 use rustc_hir::def_id::{
17 CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_ID, CRATE_DEF_INDEX, LOCAL_CRATE,
19 use rustc_hir::definitions::DefPathData;
20 use rustc_hir::intravisit::{self, Visitor};
21 use rustc_hir::lang_items::LangItem;
22 use rustc_middle::hir::nested_filter;
23 use rustc_middle::middle::dependency_format::Linkage;
24 use rustc_middle::middle::exported_symbols::{
25 metadata_symbol_name, ExportedSymbol, SymbolExportInfo,
27 use rustc_middle::mir::interpret;
28 use rustc_middle::traits::specialization_graph;
29 use rustc_middle::ty::codec::TyEncoder;
30 use rustc_middle::ty::fast_reject::{self, SimplifiedType, TreatParams};
31 use rustc_middle::ty::query::Providers;
32 use rustc_middle::ty::{self, SymbolName, Ty, TyCtxt};
33 use rustc_middle::util::common::to_readable_str;
34 use rustc_serialize::{opaque, Decodable, Decoder, Encodable, Encoder};
35 use rustc_session::config::{CrateType, OptLevel};
36 use rustc_session::cstore::{ForeignModule, LinkagePreference, NativeLib};
37 use rustc_span::hygiene::{ExpnIndex, HygieneEncodeContext, MacroKind};
38 use rustc_span::symbol::{sym, Symbol};
40 self, DebuggerVisualizerFile, ExternalSource, FileName, SourceFile, Span, SyntaxContext,
42 use std::borrow::Borrow;
43 use std::collections::hash_map::Entry;
45 use std::io::{Read, Seek, Write};
47 use std::num::NonZeroUsize;
48 use std::path::{Path, PathBuf};
50 pub(super) struct EncodeContext<'a, 'tcx> {
51 opaque: opaque::FileEncoder,
53 feat: &'tcx rustc_feature::Features,
55 tables: TableBuilders,
57 lazy_state: LazyState,
58 type_shorthands: FxHashMap<Ty<'tcx>, usize>,
59 predicate_shorthands: FxHashMap<ty::PredicateKind<'tcx>, usize>,
61 interpret_allocs: FxIndexSet<interpret::AllocId>,
63 // This is used to speed up Span encoding.
64 // The `usize` is an index into the `MonotonicVec`
65 // that stores the `SourceFile`
66 source_file_cache: (Lrc<SourceFile>, usize),
67 // The indices (into the `SourceMap`'s `MonotonicVec`)
68 // of all of the `SourceFiles` that we need to serialize.
69 // When we serialize a `Span`, we insert the index of its
70 // `SourceFile` into the `FxIndexSet`.
71 // The order inside the `FxIndexSet` is used as on-disk
72 // order of `SourceFiles`, and encoded inside `Span`s.
73 required_source_files: Option<FxIndexSet<usize>>,
75 hygiene_ctxt: &'a HygieneEncodeContext,
76 symbol_table: FxHashMap<Symbol, usize>,
79 /// If the current crate is a proc-macro, returns early with `LazyArray::empty()`.
80 /// This is useful for skipping the encoding of things that aren't needed
81 /// for proc-macro crates.
82 macro_rules! empty_proc_macro {
84 if $self.is_proc_macro {
85 return LazyArray::empty();
90 macro_rules! encoder_methods {
91 ($($name:ident($ty:ty);)*) => {
92 $(fn $name(&mut self, value: $ty) {
93 self.opaque.$name(value)
98 impl<'a, 'tcx> Encoder for EncodeContext<'a, 'tcx> {
119 emit_raw_bytes(&[u8]);
123 impl<'a, 'tcx, T> Encodable<EncodeContext<'a, 'tcx>> for LazyValue<T> {
124 fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) {
125 e.emit_lazy_distance(self.position);
129 impl<'a, 'tcx, T> Encodable<EncodeContext<'a, 'tcx>> for LazyArray<T> {
130 fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) {
131 e.emit_usize(self.num_elems);
132 if self.num_elems > 0 {
133 e.emit_lazy_distance(self.position)
138 impl<'a, 'tcx, I, T> Encodable<EncodeContext<'a, 'tcx>> for LazyTable<I, T> {
139 fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) {
140 e.emit_usize(self.encoded_size);
141 e.emit_lazy_distance(self.position);
145 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for CrateNum {
146 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
147 if *self != LOCAL_CRATE && s.is_proc_macro {
148 panic!("Attempted to encode non-local CrateNum {self:?} for proc-macro crate");
150 s.emit_u32(self.as_u32());
154 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for DefIndex {
155 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
156 s.emit_u32(self.as_u32());
160 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for ExpnIndex {
161 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
162 s.emit_u32(self.as_u32());
166 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for SyntaxContext {
167 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
168 rustc_span::hygiene::raw_encode_syntax_context(*self, &s.hygiene_ctxt, s);
172 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for ExpnId {
173 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
174 if self.krate == LOCAL_CRATE {
175 // We will only write details for local expansions. Non-local expansions will fetch
176 // data from the corresponding crate's metadata.
177 // FIXME(#43047) FIXME(#74731) We may eventually want to avoid relying on external
178 // metadata from proc-macro crates.
179 s.hygiene_ctxt.schedule_expn_data_for_encoding(*self);
181 self.krate.encode(s);
182 self.local_id.encode(s);
186 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
187 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
188 let span = self.data();
190 // Don't serialize any `SyntaxContext`s from a proc-macro crate,
191 // since we don't load proc-macro dependencies during serialization.
192 // This means that any hygiene information from macros used *within*
193 // a proc-macro crate (e.g. invoking a macro that expands to a proc-macro
194 // definition) will be lost.
196 // This can show up in two ways:
198 // 1. Any hygiene information associated with identifier of
199 // a proc macro (e.g. `#[proc_macro] pub fn $name`) will be lost.
200 // Since proc-macros can only be invoked from a different crate,
201 // real code should never need to care about this.
203 // 2. Using `Span::def_site` or `Span::mixed_site` will not
204 // include any hygiene information associated with the definition
205 // site. This means that a proc-macro cannot emit a `$crate`
206 // identifier which resolves to one of its dependencies,
207 // which also should never come up in practice.
209 // Additionally, this affects `Span::parent`, and any other
210 // span inspection APIs that would otherwise allow traversing
211 // the `SyntaxContexts` associated with a span.
213 // None of these user-visible effects should result in any
214 // cross-crate inconsistencies (getting one behavior in the same
215 // crate, and a different behavior in another crate) due to the
216 // limited surface that proc-macros can expose.
218 // IMPORTANT: If this is ever changed, be sure to update
219 // `rustc_span::hygiene::raw_encode_expn_id` to handle
220 // encoding `ExpnData` for proc-macro crates.
222 SyntaxContext::root().encode(s);
228 return TAG_PARTIAL_SPAN.encode(s);
231 // The Span infrastructure should make sure that this invariant holds:
232 debug_assert!(span.lo <= span.hi);
234 if !s.source_file_cache.0.contains(span.lo) {
235 let source_map = s.tcx.sess.source_map();
236 let source_file_index = source_map.lookup_source_file_idx(span.lo);
237 s.source_file_cache =
238 (source_map.files()[source_file_index].clone(), source_file_index);
240 let (ref source_file, source_file_index) = s.source_file_cache;
241 debug_assert!(source_file.contains(span.lo));
243 if !source_file.contains(span.hi) {
244 // Unfortunately, macro expansion still sometimes generates Spans
245 // that malformed in this way.
246 return TAG_PARTIAL_SPAN.encode(s);
249 // There are two possible cases here:
250 // 1. This span comes from a 'foreign' crate - e.g. some crate upstream of the
251 // crate we are writing metadata for. When the metadata for *this* crate gets
252 // deserialized, the deserializer will need to know which crate it originally came
253 // from. We use `TAG_VALID_SPAN_FOREIGN` to indicate that a `CrateNum` should
254 // be deserialized after the rest of the span data, which tells the deserializer
255 // which crate contains the source map information.
256 // 2. This span comes from our own crate. No special handling is needed - we just
257 // write `TAG_VALID_SPAN_LOCAL` to let the deserializer know that it should use
258 // our own source map information.
260 // If we're a proc-macro crate, we always treat this as a local `Span`.
261 // In `encode_source_map`, we serialize foreign `SourceFile`s into our metadata
262 // if we're a proc-macro crate.
263 // This allows us to avoid loading the dependencies of proc-macro crates: all of
264 // the information we need to decode `Span`s is stored in the proc-macro crate.
265 let (tag, metadata_index) = if source_file.is_imported() && !s.is_proc_macro {
266 // To simplify deserialization, we 'rebase' this span onto the crate it originally came
267 // from (the crate that 'owns' the file it references. These rebased 'lo' and 'hi'
268 // values are relative to the source map information for the 'foreign' crate whose
269 // CrateNum we write into the metadata. This allows `imported_source_files` to binary
270 // search through the 'foreign' crate's source map information, using the
271 // deserialized 'lo' and 'hi' values directly.
273 // All of this logic ensures that the final result of deserialization is a 'normal'
274 // Span that can be used without any additional trouble.
275 let metadata_index = {
276 // Introduce a new scope so that we drop the 'lock()' temporary
277 match &*source_file.external_src.lock() {
278 ExternalSource::Foreign { metadata_index, .. } => *metadata_index,
279 src => panic!("Unexpected external source {src:?}"),
283 (TAG_VALID_SPAN_FOREIGN, metadata_index)
285 // Record the fact that we need to encode the data for this `SourceFile`
287 s.required_source_files.as_mut().expect("Already encoded SourceMap!");
288 let (metadata_index, _) = source_files.insert_full(source_file_index);
289 let metadata_index: u32 =
290 metadata_index.try_into().expect("cannot export more than U32_MAX files");
292 (TAG_VALID_SPAN_LOCAL, metadata_index)
295 // Encode the start position relative to the file start, so we profit more from the
296 // variable-length integer encoding.
297 let lo = span.lo - source_file.start_pos;
299 // Encode length which is usually less than span.hi and profits more
300 // from the variable-length integer encoding that we use.
301 let len = span.hi - span.lo;
307 // Encode the index of the `SourceFile` for the span, in order to make decoding faster.
308 metadata_index.encode(s);
310 if tag == TAG_VALID_SPAN_FOREIGN {
311 // This needs to be two lines to avoid holding the `s.source_file_cache`
312 // while calling `cnum.encode(s)`
313 let cnum = s.source_file_cache.0.cnum;
319 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Symbol {
320 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
321 // if symbol preinterned, emit tag and symbol index
322 if self.is_preinterned() {
323 s.opaque.emit_u8(SYMBOL_PREINTERNED);
324 s.opaque.emit_u32(self.as_u32());
326 // otherwise write it as string or as offset to it
327 match s.symbol_table.entry(*self) {
328 Entry::Vacant(o) => {
329 s.opaque.emit_u8(SYMBOL_STR);
330 let pos = s.opaque.position();
332 s.emit_str(self.as_str());
334 Entry::Occupied(o) => {
336 s.emit_u8(SYMBOL_OFFSET);
344 impl<'a, 'tcx> TyEncoder for EncodeContext<'a, 'tcx> {
345 const CLEAR_CROSS_CRATE: bool = true;
347 type I = TyCtxt<'tcx>;
349 fn position(&self) -> usize {
350 self.opaque.position()
353 fn type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize> {
354 &mut self.type_shorthands
357 fn predicate_shorthands(&mut self) -> &mut FxHashMap<ty::PredicateKind<'tcx>, usize> {
358 &mut self.predicate_shorthands
361 fn encode_alloc_id(&mut self, alloc_id: &rustc_middle::mir::interpret::AllocId) {
362 let (index, _) = self.interpret_allocs.insert_full(*alloc_id);
368 // Shorthand for `$self.$tables.$table.set($def_id.index, $self.lazy_value($value))`, which would
369 // normally need extra variables to avoid errors about multiple mutable borrows.
370 macro_rules! record {
371 ($self:ident.$tables:ident.$table:ident[$def_id:expr] <- $value:expr) => {{
374 let lazy = $self.lazy(value);
375 $self.$tables.$table.set($def_id.index, lazy);
380 // Shorthand for `$self.$tables.$table.set($def_id.index, $self.lazy_value($value))`, which would
381 // normally need extra variables to avoid errors about multiple mutable borrows.
382 macro_rules! record_array {
383 ($self:ident.$tables:ident.$table:ident[$def_id:expr] <- $value:expr) => {{
386 let lazy = $self.lazy_array(value);
387 $self.$tables.$table.set($def_id.index, lazy);
392 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
393 fn emit_lazy_distance(&mut self, position: NonZeroUsize) {
394 let pos = position.get();
395 let distance = match self.lazy_state {
396 LazyState::NoNode => bug!("emit_lazy_distance: outside of a metadata node"),
397 LazyState::NodeStart(start) => {
398 let start = start.get();
399 assert!(pos <= start);
402 LazyState::Previous(last_pos) => {
404 last_pos <= position,
405 "make sure that the calls to `lazy*` \
406 are in the same order as the metadata fields",
408 position.get() - last_pos.get()
411 self.lazy_state = LazyState::Previous(NonZeroUsize::new(pos).unwrap());
412 self.emit_usize(distance);
415 fn lazy<T: ParameterizedOverTcx, B: Borrow<T::Value<'tcx>>>(&mut self, value: B) -> LazyValue<T>
417 T::Value<'tcx>: Encodable<EncodeContext<'a, 'tcx>>,
419 let pos = NonZeroUsize::new(self.position()).unwrap();
421 assert_eq!(self.lazy_state, LazyState::NoNode);
422 self.lazy_state = LazyState::NodeStart(pos);
423 value.borrow().encode(self);
424 self.lazy_state = LazyState::NoNode;
426 assert!(pos.get() <= self.position());
428 LazyValue::from_position(pos)
431 fn lazy_array<T: ParameterizedOverTcx, I: IntoIterator<Item = B>, B: Borrow<T::Value<'tcx>>>(
436 T::Value<'tcx>: Encodable<EncodeContext<'a, 'tcx>>,
438 let pos = NonZeroUsize::new(self.position()).unwrap();
440 assert_eq!(self.lazy_state, LazyState::NoNode);
441 self.lazy_state = LazyState::NodeStart(pos);
442 let len = values.into_iter().map(|value| value.borrow().encode(self)).count();
443 self.lazy_state = LazyState::NoNode;
445 assert!(pos.get() <= self.position());
447 LazyArray::from_position_and_num_elems(pos, len)
450 fn encode_info_for_items(&mut self) {
451 self.encode_info_for_mod(CRATE_DEF_ID, self.tcx.hir().root_module());
453 // Proc-macro crates only export proc-macro items, which are looked
454 // up using `proc_macro_data`
455 if self.is_proc_macro {
459 self.tcx.hir().visit_all_item_likes_in_crate(self);
462 fn encode_def_path_table(&mut self) {
463 let table = self.tcx.def_path_table();
464 if self.is_proc_macro {
465 for def_index in std::iter::once(CRATE_DEF_INDEX)
466 .chain(self.tcx.resolutions(()).proc_macros.iter().map(|p| p.local_def_index))
468 let def_key = self.lazy(table.def_key(def_index));
469 let def_path_hash = table.def_path_hash(def_index);
470 self.tables.def_keys.set(def_index, def_key);
471 self.tables.def_path_hashes.set(def_index, def_path_hash);
474 for (def_index, def_key, def_path_hash) in table.enumerated_keys_and_path_hashes() {
475 let def_key = self.lazy(def_key);
476 self.tables.def_keys.set(def_index, def_key);
477 self.tables.def_path_hashes.set(def_index, *def_path_hash);
482 fn encode_def_path_hash_map(&mut self) -> LazyValue<DefPathHashMapRef<'static>> {
483 self.lazy(DefPathHashMapRef::BorrowedFromTcx(self.tcx.def_path_hash_to_def_index_map()))
486 fn encode_source_map(&mut self) -> LazyTable<u32, Option<LazyValue<rustc_span::SourceFile>>> {
487 let source_map = self.tcx.sess.source_map();
488 let all_source_files = source_map.files();
490 // By replacing the `Option` with `None`, we ensure that we can't
491 // accidentally serialize any more `Span`s after the source map encoding
493 let required_source_files = self.required_source_files.take().unwrap();
495 let working_directory = &self.tcx.sess.opts.working_dir;
497 let mut adapted = TableBuilder::default();
499 // Only serialize `SourceFile`s that were used during the encoding of a `Span`.
501 // The order in which we encode source files is important here: the on-disk format for
502 // `Span` contains the index of the corresponding `SourceFile`.
503 for (on_disk_index, &source_file_index) in required_source_files.iter().enumerate() {
504 let source_file = &all_source_files[source_file_index];
505 // Don't serialize imported `SourceFile`s, unless we're in a proc-macro crate.
506 assert!(!source_file.is_imported() || self.is_proc_macro);
508 // At export time we expand all source file paths to absolute paths because
509 // downstream compilation sessions can have a different compiler working
510 // directory, so relative paths from this or any other upstream crate
511 // won't be valid anymore.
513 // At this point we also erase the actual on-disk path and only keep
514 // the remapped version -- as is necessary for reproducible builds.
515 let mut source_file = match source_file.name {
516 FileName::Real(ref original_file_name) => {
517 let adapted_file_name = source_map
519 .to_embeddable_absolute_path(original_file_name.clone(), working_directory);
521 if adapted_file_name != *original_file_name {
522 let mut adapted: SourceFile = (**source_file).clone();
523 adapted.name = FileName::Real(adapted_file_name);
524 adapted.name_hash = {
525 let mut hasher: StableHasher = StableHasher::new();
526 adapted.name.hash(&mut hasher);
527 hasher.finish::<u128>()
535 // expanded code, not from a file
536 _ => source_file.clone(),
539 // We're serializing this `SourceFile` into our crate metadata,
540 // so mark it as coming from this crate.
541 // This also ensures that we don't try to deserialize the
542 // `CrateNum` for a proc-macro dependency - since proc macro
543 // dependencies aren't loaded when we deserialize a proc-macro,
544 // trying to remap the `CrateNum` would fail.
545 if self.is_proc_macro {
546 Lrc::make_mut(&mut source_file).cnum = LOCAL_CRATE;
549 let on_disk_index: u32 =
550 on_disk_index.try_into().expect("cannot export more than U32_MAX files");
551 adapted.set(on_disk_index, self.lazy(source_file));
554 adapted.encode(&mut self.opaque)
557 fn encode_crate_root(&mut self) -> LazyValue<CrateRoot> {
559 let mut stats: Vec<(&'static str, usize)> = Vec::with_capacity(32);
562 ($label:literal, $f:expr) => {{
563 let orig_pos = self.position();
565 stats.push(($label, self.position() - orig_pos));
570 // We have already encoded some things. Get their combined size from the current position.
571 stats.push(("preamble", self.position()));
573 let (crate_deps, dylib_dependency_formats) =
574 stat!("dep", || (self.encode_crate_deps(), self.encode_dylib_dependency_formats()));
576 let lib_features = stat!("lib-features", || self.encode_lib_features());
578 let stability_implications =
579 stat!("stability-implications", || self.encode_stability_implications());
581 let (lang_items, lang_items_missing) = stat!("lang-items", || {
582 (self.encode_lang_items(), self.encode_lang_items_missing())
585 let diagnostic_items = stat!("diagnostic-items", || self.encode_diagnostic_items());
587 let native_libraries = stat!("native-libs", || self.encode_native_libraries());
589 let foreign_modules = stat!("foreign-modules", || self.encode_foreign_modules());
591 _ = stat!("def-path-table", || self.encode_def_path_table());
593 // Encode the def IDs of traits, for rustdoc and diagnostics.
594 let traits = stat!("traits", || self.encode_traits());
596 // Encode the def IDs of impls, for coherence checking.
597 let impls = stat!("impls", || self.encode_impls());
599 let incoherent_impls = stat!("incoherent-impls", || self.encode_incoherent_impls());
601 _ = stat!("mir", || self.encode_mir());
603 _ = stat!("items", || {
604 self.encode_def_ids();
605 self.encode_info_for_items();
608 let interpret_alloc_index = stat!("interpret-alloc-index", || {
609 let mut interpret_alloc_index = Vec::new();
611 trace!("beginning to encode alloc ids");
613 let new_n = self.interpret_allocs.len();
614 // if we have found new ids, serialize those, too
619 trace!("encoding {} further alloc ids", new_n - n);
620 for idx in n..new_n {
621 let id = self.interpret_allocs[idx];
622 let pos = self.position() as u32;
623 interpret_alloc_index.push(pos);
624 interpret::specialized_encode_alloc_id(self, tcx, id);
628 self.lazy_array(interpret_alloc_index)
631 // Encode the proc macro data. This affects `tables`, so we need to do this before we
632 // encode the tables. This overwrites def_keys, so it must happen after
633 // encode_def_path_table.
634 let proc_macro_data = stat!("proc-macro-data", || self.encode_proc_macros());
636 let tables = stat!("tables", || self.tables.encode(&mut self.opaque));
638 let debugger_visualizers =
639 stat!("debugger-visualizers", || self.encode_debugger_visualizers());
641 // Encode exported symbols info. This is prefetched in `encode_metadata` so we encode
642 // this as late as possible to give the prefetching as much time as possible to complete.
643 let exported_symbols = stat!("exported-symbols", || {
644 self.encode_exported_symbols(&tcx.exported_symbols(LOCAL_CRATE))
647 // Encode the hygiene data.
648 // IMPORTANT: this *must* be the last thing that we encode (other than `SourceMap`). The
649 // process of encoding other items (e.g. `optimized_mir`) may cause us to load data from
650 // the incremental cache. If this causes us to deserialize a `Span`, then we may load
651 // additional `SyntaxContext`s into the global `HygieneData`. Therefore, we need to encode
652 // the hygiene data last to ensure that we encode any `SyntaxContext`s that might be used.
653 let (syntax_contexts, expn_data, expn_hashes) = stat!("hygiene", || self.encode_hygiene());
655 let def_path_hash_map = stat!("def-path-hash-map", || self.encode_def_path_hash_map());
657 // Encode source_map. This needs to be done last, because encoding `Span`s tells us which
658 // `SourceFiles` we actually need to encode.
659 let source_map = stat!("source-map", || self.encode_source_map());
661 let root = stat!("final", || {
662 let attrs = tcx.hir().krate_attrs();
663 self.lazy(CrateRoot {
664 name: tcx.crate_name(LOCAL_CRATE),
665 extra_filename: tcx.sess.opts.cg.extra_filename.clone(),
666 triple: tcx.sess.opts.target_triple.clone(),
667 hash: tcx.crate_hash(LOCAL_CRATE),
668 stable_crate_id: tcx.def_path_hash(LOCAL_CRATE.as_def_id()).stable_crate_id(),
669 required_panic_strategy: tcx.required_panic_strategy(LOCAL_CRATE),
670 panic_in_drop_strategy: tcx.sess.opts.unstable_opts.panic_in_drop,
671 edition: tcx.sess.edition(),
672 has_global_allocator: tcx.has_global_allocator(LOCAL_CRATE),
673 has_alloc_error_handler: tcx.has_alloc_error_handler(LOCAL_CRATE),
674 has_panic_handler: tcx.has_panic_handler(LOCAL_CRATE),
675 has_default_lib_allocator: tcx
677 .contains_name(&attrs, sym::default_lib_allocator),
679 debugger_visualizers,
680 compiler_builtins: tcx.sess.contains_name(&attrs, sym::compiler_builtins),
681 needs_allocator: tcx.sess.contains_name(&attrs, sym::needs_allocator),
682 needs_panic_runtime: tcx.sess.contains_name(&attrs, sym::needs_panic_runtime),
683 no_builtins: tcx.sess.contains_name(&attrs, sym::no_builtins),
684 panic_runtime: tcx.sess.contains_name(&attrs, sym::panic_runtime),
685 profiler_runtime: tcx.sess.contains_name(&attrs, sym::profiler_runtime),
686 symbol_mangling_version: tcx.sess.opts.get_symbol_mangling_version(),
689 dylib_dependency_formats,
691 stability_implications,
702 interpret_alloc_index,
711 let total_bytes = self.position();
713 let computed_total_bytes: usize = stats.iter().map(|(_, size)| size).sum();
714 assert_eq!(total_bytes, computed_total_bytes);
716 if tcx.sess.opts.unstable_opts.meta_stats {
719 // Rewind and re-read all the metadata to count the zero bytes we wrote.
720 let pos_before_rewind = self.opaque.file().stream_position().unwrap();
721 let mut zero_bytes = 0;
722 self.opaque.file().rewind().unwrap();
723 let file = std::io::BufReader::new(self.opaque.file());
724 for e in file.bytes() {
729 assert_eq!(self.opaque.file().stream_position().unwrap(), pos_before_rewind);
731 stats.sort_by_key(|&(_, usize)| usize);
733 let prefix = "meta-stats";
734 let perc = |bytes| (bytes * 100) as f64 / total_bytes as f64;
736 eprintln!("{prefix} METADATA STATS");
737 eprintln!("{} {:<23}{:>10}", prefix, "Section", "Size");
738 eprintln!("{prefix} ----------------------------------------------------------------");
739 for (label, size) in stats {
741 "{} {:<23}{:>10} ({:4.1}%)",
744 to_readable_str(size),
748 eprintln!("{prefix} ----------------------------------------------------------------");
750 "{} {:<23}{:>10} (of which {:.1}% are zero bytes)",
753 to_readable_str(total_bytes),
756 eprintln!("{prefix}");
763 struct AnalyzeAttrState {
765 may_have_doc_links: bool,
769 /// Returns whether an attribute needs to be recorded in metadata, that is, if it's usable and
770 /// useful in downstream crates. Local-only attributes are an obvious example, but some
771 /// rustdoc-specific attributes can equally be of use while documenting the current crate only.
773 /// Removing these superfluous attributes speeds up compilation by making the metadata smaller.
775 /// Note: the `is_exported` parameter is used to cache whether the given `DefId` has a public
776 /// visibility: this is a piece of data that can be computed once per defid, and not once per
777 /// attribute. Some attributes would only be usable downstream if they are public.
779 fn analyze_attr(attr: &Attribute, state: &mut AnalyzeAttrState) -> bool {
780 let mut should_encode = false;
781 if rustc_feature::is_builtin_only_local(attr.name_or_empty()) {
782 // Attributes marked local-only don't need to be encoded for downstream crates.
783 } else if let Some(s) = attr.doc_str() {
784 // We keep all doc comments reachable to rustdoc because they might be "imported" into
785 // downstream crates if they use `#[doc(inline)]` to copy an item's documentation into
787 if state.is_exported {
788 should_encode = true;
789 if comments::may_have_doc_links(s.as_str()) {
790 state.may_have_doc_links = true;
793 } else if attr.has_name(sym::doc) {
794 // If this is a `doc` attribute that doesn't have anything except maybe `inline` (as in
795 // `#[doc(inline)]`), then we can remove it. It won't be inlinable in downstream crates.
796 if let Some(item_list) = attr.meta_item_list() {
797 for item in item_list {
798 if !item.has_name(sym::inline) {
799 should_encode = true;
800 if item.has_name(sym::hidden) {
801 state.is_doc_hidden = true;
808 should_encode = true;
813 fn should_encode_visibility(def_kind: DefKind) -> bool {
823 | DefKind::TraitAlias
827 | DefKind::Static(..)
830 | DefKind::AssocConst
833 | DefKind::ForeignMod
835 | DefKind::ImplTraitPlaceholder
837 | DefKind::Field => true,
839 | DefKind::ConstParam
840 | DefKind::LifetimeParam
842 | DefKind::InlineConst
846 | DefKind::ExternCrate => false,
850 fn should_encode_stability(def_kind: DefKind) -> bool {
859 | DefKind::AssocConst
861 | DefKind::ConstParam
862 | DefKind::Static(..)
865 | DefKind::ForeignMod
868 | DefKind::ImplTraitPlaceholder
873 | DefKind::TraitAlias
875 | DefKind::ForeignTy => true,
877 | DefKind::LifetimeParam
879 | DefKind::InlineConst
883 | DefKind::ExternCrate => false,
887 /// Whether we should encode MIR.
889 /// Computing, optimizing and encoding the MIR is a relatively expensive operation.
890 /// We want to avoid this work when not required. Therefore:
891 /// - we only compute `mir_for_ctfe` on items with const-eval semantics;
892 /// - we skip `optimized_mir` for check runs.
894 /// Return a pair, resp. for CTFE and for LLVM.
895 fn should_encode_mir(tcx: TyCtxt<'_>, def_id: LocalDefId) -> (bool, bool) {
896 match tcx.def_kind(def_id) {
898 DefKind::Ctor(_, _) => {
899 let mir_opt_base = tcx.sess.opts.output_types.should_codegen()
900 || tcx.sess.opts.unstable_opts.always_encode_mir;
905 | DefKind::InlineConst
906 | DefKind::AssocConst
907 | DefKind::Static(..)
908 | DefKind::Const => (true, false),
909 // Full-fledged functions + closures
910 DefKind::AssocFn | DefKind::Fn | DefKind::Closure => {
911 let generics = tcx.generics_of(def_id);
912 let needs_inline = (generics.requires_monomorphization(tcx)
913 || tcx.codegen_fn_attrs(def_id).requests_inline())
914 && tcx.sess.opts.output_types.should_codegen();
915 // The function has a `const` modifier or is in a `#[const_trait]`.
916 let is_const_fn = tcx.is_const_fn_raw(def_id.to_def_id())
917 || tcx.is_const_default_method(def_id.to_def_id());
918 let always_encode_mir = tcx.sess.opts.unstable_opts.always_encode_mir;
919 (is_const_fn, needs_inline || always_encode_mir)
921 // Generators require optimized MIR to compute layout.
922 DefKind::Generator => (false, true),
923 // The others don't have MIR.
928 fn should_encode_variances(def_kind: DefKind) -> bool {
935 | DefKind::ImplTraitPlaceholder
938 | DefKind::AssocFn => true,
942 | DefKind::AssocConst
944 | DefKind::ConstParam
945 | DefKind::Static(..)
947 | DefKind::ForeignMod
951 | DefKind::TraitAlias
955 | DefKind::LifetimeParam
957 | DefKind::InlineConst
961 | DefKind::ExternCrate => false,
965 fn should_encode_generics(def_kind: DefKind) -> bool {
974 | DefKind::TraitAlias
978 | DefKind::Static(..)
981 | DefKind::AssocConst
983 | DefKind::InlineConst
985 | DefKind::ImplTraitPlaceholder
990 | DefKind::Generator => true,
992 | DefKind::ForeignMod
993 | DefKind::ConstParam
996 | DefKind::LifetimeParam
998 | DefKind::ExternCrate => false,
1002 fn should_encode_type(tcx: TyCtxt<'_>, def_id: LocalDefId, def_kind: DefKind) -> bool {
1012 | DefKind::Static(..)
1015 | DefKind::ForeignTy
1018 | DefKind::AssocConst
1020 | DefKind::Generator
1021 | DefKind::ConstParam
1022 | DefKind::AnonConst
1023 | DefKind::InlineConst => true,
1025 DefKind::ImplTraitPlaceholder => {
1026 let parent_def_id = tcx.impl_trait_in_trait_parent(def_id.to_def_id());
1027 let assoc_item = tcx.associated_item(parent_def_id);
1028 match assoc_item.container {
1029 // Always encode an RPIT in an impl fn, since it always has a body
1030 ty::AssocItemContainer::ImplContainer => true,
1031 ty::AssocItemContainer::TraitContainer => {
1032 // Encode an RPIT for a trait only if the trait has a default body
1033 assoc_item.defaultness(tcx).has_value()
1038 DefKind::AssocTy => {
1039 let assoc_item = tcx.associated_item(def_id);
1040 match assoc_item.container {
1041 ty::AssocItemContainer::ImplContainer => true,
1042 ty::AssocItemContainer::TraitContainer => assoc_item.defaultness(tcx).has_value(),
1045 DefKind::TyParam => {
1046 let hir::Node::GenericParam(param) = tcx.hir().get_by_def_id(def_id) else { bug!() };
1047 let hir::GenericParamKind::Type { default, .. } = param.kind else { bug!() };
1052 | DefKind::TraitAlias
1054 | DefKind::ForeignMod
1055 | DefKind::Macro(..)
1057 | DefKind::LifetimeParam
1058 | DefKind::GlobalAsm
1059 | DefKind::ExternCrate => false,
1063 fn should_encode_const(def_kind: DefKind) -> bool {
1065 DefKind::Const | DefKind::AssocConst | DefKind::AnonConst => true,
1074 | DefKind::Static(..)
1077 | DefKind::ImplTraitPlaceholder
1078 | DefKind::ForeignTy
1082 | DefKind::Generator
1083 | DefKind::ConstParam
1084 | DefKind::InlineConst
1088 | DefKind::TraitAlias
1090 | DefKind::ForeignMod
1091 | DefKind::Macro(..)
1093 | DefKind::LifetimeParam
1094 | DefKind::GlobalAsm
1095 | DefKind::ExternCrate => false,
1099 fn should_encode_trait_impl_trait_tys(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
1100 if tcx.def_kind(def_id) != DefKind::AssocFn {
1104 let Some(item) = tcx.opt_associated_item(def_id) else { return false; };
1105 if item.container != ty::AssocItemContainer::ImplContainer {
1109 let Some(trait_item_def_id) = item.trait_item_def_id else { return false; };
1111 // FIXME(RPITIT): This does a somewhat manual walk through the signature
1112 // of the trait fn to look for any RPITITs, but that's kinda doing a lot
1113 // of work. We can probably remove this when we refactor RPITITs to be
1114 // associated types.
1115 tcx.fn_sig(trait_item_def_id).subst_identity().skip_binder().output().walk().any(|arg| {
1116 if let ty::GenericArgKind::Type(ty) = arg.unpack()
1117 && let ty::Alias(ty::Projection, data) = ty.kind()
1118 && tcx.def_kind(data.def_id) == DefKind::ImplTraitPlaceholder
1127 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
1128 fn encode_attrs(&mut self, def_id: LocalDefId) {
1130 let mut state = AnalyzeAttrState {
1131 is_exported: tcx.effective_visibilities(()).is_exported(def_id),
1132 may_have_doc_links: false,
1133 is_doc_hidden: false,
1137 .attrs(tcx.hir().local_def_id_to_hir_id(def_id))
1139 .filter(|attr| analyze_attr(attr, &mut state));
1141 record_array!(self.tables.attributes[def_id.to_def_id()] <- attr_iter);
1143 let mut attr_flags = AttrFlags::empty();
1144 if state.may_have_doc_links {
1145 attr_flags |= AttrFlags::MAY_HAVE_DOC_LINKS;
1147 if state.is_doc_hidden {
1148 attr_flags |= AttrFlags::IS_DOC_HIDDEN;
1150 if !attr_flags.is_empty() {
1151 self.tables.attr_flags.set_nullable(def_id.local_def_index, attr_flags);
1155 fn encode_def_ids(&mut self) {
1156 if self.is_proc_macro {
1160 for local_id in tcx.iter_local_def_id() {
1161 let def_id = local_id.to_def_id();
1162 let def_kind = tcx.opt_def_kind(local_id);
1163 let Some(def_kind) = def_kind else { continue };
1164 self.tables.opt_def_kind.set(def_id.index, def_kind);
1165 let def_span = tcx.def_span(local_id);
1166 record!(self.tables.def_span[def_id] <- def_span);
1167 self.encode_attrs(local_id);
1168 record!(self.tables.expn_that_defined[def_id] <- self.tcx.expn_that_defined(def_id));
1169 if let Some(ident_span) = tcx.def_ident_span(def_id) {
1170 record!(self.tables.def_ident_span[def_id] <- ident_span);
1172 if def_kind.has_codegen_attrs() {
1173 record!(self.tables.codegen_fn_attrs[def_id] <- self.tcx.codegen_fn_attrs(def_id));
1175 if should_encode_visibility(def_kind) {
1177 self.tcx.local_visibility(local_id).map_id(|def_id| def_id.local_def_index);
1178 record!(self.tables.visibility[def_id] <- vis);
1180 if should_encode_stability(def_kind) {
1181 self.encode_stability(def_id);
1182 self.encode_const_stability(def_id);
1183 self.encode_default_body_stability(def_id);
1184 self.encode_deprecation(def_id);
1186 if should_encode_variances(def_kind) {
1187 let v = self.tcx.variances_of(def_id);
1188 record_array!(self.tables.variances_of[def_id] <- v);
1190 if should_encode_generics(def_kind) {
1191 let g = tcx.generics_of(def_id);
1192 record!(self.tables.generics_of[def_id] <- g);
1193 record!(self.tables.explicit_predicates_of[def_id] <- self.tcx.explicit_predicates_of(def_id));
1194 let inferred_outlives = self.tcx.inferred_outlives_of(def_id);
1195 if !inferred_outlives.is_empty() {
1196 record_array!(self.tables.inferred_outlives_of[def_id] <- inferred_outlives);
1199 if should_encode_type(tcx, local_id, def_kind) {
1200 record!(self.tables.type_of[def_id] <- self.tcx.type_of(def_id));
1202 if let DefKind::TyParam = def_kind {
1203 let default = self.tcx.object_lifetime_default(def_id);
1204 record!(self.tables.object_lifetime_default[def_id] <- default);
1206 if let DefKind::Trait | DefKind::TraitAlias = def_kind {
1207 record!(self.tables.super_predicates_of[def_id] <- self.tcx.super_predicates_of(def_id));
1209 if let DefKind::Enum | DefKind::Struct | DefKind::Union = def_kind {
1210 self.encode_info_for_adt(def_id);
1212 if should_encode_trait_impl_trait_tys(tcx, def_id)
1213 && let Ok(table) = self.tcx.collect_return_position_impl_trait_in_trait_tys(def_id)
1215 record!(self.tables.trait_impl_trait_tys[def_id] <- table);
1218 let inherent_impls = tcx.with_stable_hashing_context(|hcx| {
1219 tcx.crate_inherent_impls(()).inherent_impls.to_sorted(&hcx, true)
1222 for (def_id, implementations) in inherent_impls {
1223 if implementations.is_empty() {
1226 record_array!(self.tables.inherent_impls[def_id.to_def_id()] <- implementations.iter().map(|&def_id| {
1227 assert!(def_id.is_local());
1233 #[instrument(level = "trace", skip(self))]
1234 fn encode_info_for_adt(&mut self, def_id: DefId) {
1236 let adt_def = tcx.adt_def(def_id);
1237 record!(self.tables.repr_options[def_id] <- adt_def.repr());
1239 let params_in_repr = self.tcx.params_in_repr(def_id);
1240 record!(self.tables.params_in_repr[def_id] <- params_in_repr);
1242 if adt_def.is_enum() {
1243 record_array!(self.tables.children[def_id] <- iter::from_generator(||
1244 for variant in tcx.adt_def(def_id).variants() {
1245 yield variant.def_id.index;
1246 // Encode constructors which take a separate slot in value namespace.
1247 if let Some(ctor_def_id) = variant.ctor_def_id() {
1248 yield ctor_def_id.index;
1253 // For non-enum, there is only one variant, and its def_id is the adt's.
1254 debug_assert_eq!(adt_def.variants().len(), 1);
1255 debug_assert_eq!(adt_def.non_enum_variant().def_id, def_id);
1256 // Therefore, the loop over variants will encode its fields as the adt's children.
1259 for variant in adt_def.variants().iter() {
1260 let data = VariantData {
1261 discr: variant.discr,
1262 ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
1263 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
1265 record!(self.tables.variant_data[variant.def_id] <- data);
1267 self.tables.constness.set(variant.def_id.index, hir::Constness::Const);
1268 record_array!(self.tables.children[variant.def_id] <- variant.fields.iter().map(|f| {
1269 assert!(f.did.is_local());
1273 if let Some((CtorKind::Fn, ctor_def_id)) = variant.ctor {
1274 self.tables.constness.set(ctor_def_id.index, hir::Constness::Const);
1275 let fn_sig = tcx.fn_sig(ctor_def_id);
1276 record!(self.tables.fn_sig[ctor_def_id] <- fn_sig);
1277 // FIXME only encode signature for ctor_def_id
1278 record!(self.tables.fn_sig[variant.def_id] <- fn_sig);
1283 fn encode_info_for_mod(&mut self, local_def_id: LocalDefId, md: &hir::Mod<'_>) {
1285 let def_id = local_def_id.to_def_id();
1286 debug!("EncodeContext::encode_info_for_mod({:?})", def_id);
1288 // If we are encoding a proc-macro crates, `encode_info_for_mod` will
1289 // only ever get called for the crate root. We still want to encode
1290 // the crate root for consistency with other crates (some of the resolver
1291 // code uses it). However, we skip encoding anything relating to child
1292 // items - we encode information about proc-macros later on.
1293 if self.is_proc_macro {
1294 // Encode this here because we don't do it in encode_def_ids.
1295 record!(self.tables.expn_that_defined[def_id] <- tcx.expn_that_defined(local_def_id));
1297 record_array!(self.tables.children[def_id] <- iter::from_generator(|| {
1298 for item_id in md.item_ids {
1299 match tcx.hir().item(*item_id).kind {
1300 // Foreign items are planted into their parent modules
1301 // from name resolution point of view.
1302 hir::ItemKind::ForeignMod { items, .. } => {
1303 for foreign_item in items {
1304 yield foreign_item.id.owner_id.def_id.local_def_index;
1307 // Only encode named non-reexport children, reexports are encoded
1308 // separately and unnamed items are not used by name resolution.
1309 hir::ItemKind::ExternCrate(..) => continue,
1310 hir::ItemKind::Struct(ref vdata, _) => {
1311 yield item_id.owner_id.def_id.local_def_index;
1312 // Encode constructors which take a separate slot in value namespace.
1313 if let Some(ctor_def_id) = vdata.ctor_def_id() {
1314 yield ctor_def_id.local_def_index;
1317 _ if tcx.def_key(item_id.owner_id.to_def_id()).get_opt_name().is_some() => {
1318 yield item_id.owner_id.def_id.local_def_index;
1325 if let Some(reexports) = tcx.module_reexports(local_def_id) {
1326 assert!(!reexports.is_empty());
1327 record_array!(self.tables.module_reexports[def_id] <- reexports);
1332 fn encode_explicit_item_bounds(&mut self, def_id: DefId) {
1333 debug!("EncodeContext::encode_explicit_item_bounds({:?})", def_id);
1334 let bounds = self.tcx.explicit_item_bounds(def_id);
1335 if !bounds.is_empty() {
1336 record_array!(self.tables.explicit_item_bounds[def_id] <- bounds);
1340 fn encode_info_for_trait_item(&mut self, def_id: DefId) {
1341 debug!("EncodeContext::encode_info_for_trait_item({:?})", def_id);
1344 let impl_defaultness = tcx.impl_defaultness(def_id.expect_local());
1345 self.tables.impl_defaultness.set(def_id.index, impl_defaultness);
1346 let trait_item = tcx.associated_item(def_id);
1347 self.tables.assoc_container.set(def_id.index, trait_item.container);
1349 match trait_item.kind {
1350 ty::AssocKind::Const => {}
1351 ty::AssocKind::Fn => {
1352 record_array!(self.tables.fn_arg_names[def_id] <- tcx.fn_arg_names(def_id));
1353 self.tables.asyncness.set(def_id.index, tcx.asyncness(def_id));
1354 self.tables.constness.set(def_id.index, hir::Constness::NotConst);
1356 ty::AssocKind::Type => {
1357 self.encode_explicit_item_bounds(def_id);
1360 if trait_item.kind == ty::AssocKind::Fn {
1361 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1365 fn encode_info_for_impl_item(&mut self, def_id: DefId) {
1366 debug!("EncodeContext::encode_info_for_impl_item({:?})", def_id);
1369 let ast_item = self.tcx.hir().expect_impl_item(def_id.expect_local());
1370 self.tables.impl_defaultness.set(def_id.index, ast_item.defaultness);
1371 let impl_item = self.tcx.associated_item(def_id);
1372 self.tables.assoc_container.set(def_id.index, impl_item.container);
1374 match impl_item.kind {
1375 ty::AssocKind::Fn => {
1376 let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind else { bug!() };
1377 self.tables.asyncness.set(def_id.index, sig.header.asyncness);
1378 record_array!(self.tables.fn_arg_names[def_id] <- self.tcx.hir().body_param_names(body));
1379 // Can be inside `impl const Trait`, so using sig.header.constness is not reliable
1380 let constness = if self.tcx.is_const_fn_raw(def_id) {
1381 hir::Constness::Const
1383 hir::Constness::NotConst
1385 self.tables.constness.set(def_id.index, constness);
1387 ty::AssocKind::Const | ty::AssocKind::Type => {}
1389 if let Some(trait_item_def_id) = impl_item.trait_item_def_id {
1390 self.tables.trait_item_def_id.set(def_id.index, trait_item_def_id.into());
1392 if impl_item.kind == ty::AssocKind::Fn {
1393 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1394 if tcx.is_intrinsic(def_id) {
1395 self.tables.is_intrinsic.set_nullable(def_id.index, true);
1400 fn encode_mir(&mut self) {
1401 if self.is_proc_macro {
1407 let keys_and_jobs = tcx.mir_keys(()).iter().filter_map(|&def_id| {
1408 let (encode_const, encode_opt) = should_encode_mir(tcx, def_id);
1409 if encode_const || encode_opt { Some((def_id, encode_const, encode_opt)) } else { None }
1411 for (def_id, encode_const, encode_opt) in keys_and_jobs {
1412 debug_assert!(encode_const || encode_opt);
1414 debug!("EntryBuilder::encode_mir({:?})", def_id);
1416 record!(self.tables.optimized_mir[def_id.to_def_id()] <- tcx.optimized_mir(def_id));
1418 if let DefKind::Generator = self.tcx.def_kind(def_id) && tcx.sess.opts.unstable_opts.drop_tracking_mir {
1419 record!(self.tables.mir_generator_witnesses[def_id.to_def_id()] <- tcx.mir_generator_witnesses(def_id));
1423 record!(self.tables.mir_for_ctfe[def_id.to_def_id()] <- tcx.mir_for_ctfe(def_id));
1425 // FIXME(generic_const_exprs): this feels wrong to have in `encode_mir`
1426 let abstract_const = tcx.thir_abstract_const(def_id);
1427 if let Ok(Some(abstract_const)) = abstract_const {
1428 record!(self.tables.thir_abstract_const[def_id.to_def_id()] <- abstract_const);
1431 if should_encode_const(tcx.def_kind(def_id)) {
1432 let qualifs = tcx.mir_const_qualif(def_id);
1433 record!(self.tables.mir_const_qualif[def_id.to_def_id()] <- qualifs);
1434 let body_id = tcx.hir().maybe_body_owned_by(def_id);
1435 if let Some(body_id) = body_id {
1436 let const_data = self.encode_rendered_const_for_body(body_id);
1437 record!(self.tables.rendered_const[def_id.to_def_id()] <- const_data);
1441 record!(self.tables.promoted_mir[def_id.to_def_id()] <- tcx.promoted_mir(def_id));
1444 ty::InstanceDef::Item(ty::WithOptConstParam::unknown(def_id.to_def_id()));
1445 let unused = tcx.unused_generic_params(instance);
1446 if !unused.all_used() {
1447 record!(self.tables.unused_generic_params[def_id.to_def_id()] <- unused);
1451 // Encode all the deduced parameter attributes for everything that has MIR, even for items
1452 // that can't be inlined. But don't if we aren't optimizing in non-incremental mode, to
1453 // save the query traffic.
1454 if tcx.sess.opts.output_types.should_codegen()
1455 && tcx.sess.opts.optimize != OptLevel::No
1456 && tcx.sess.opts.incremental.is_none()
1458 for &local_def_id in tcx.mir_keys(()) {
1459 if let DefKind::AssocFn | DefKind::Fn = tcx.def_kind(local_def_id) {
1460 record_array!(self.tables.deduced_param_attrs[local_def_id.to_def_id()] <-
1461 self.tcx.deduced_param_attrs(local_def_id.to_def_id()));
1467 fn encode_stability(&mut self, def_id: DefId) {
1468 debug!("EncodeContext::encode_stability({:?})", def_id);
1470 // The query lookup can take a measurable amount of time in crates with many items. Check if
1471 // the stability attributes are even enabled before using their queries.
1472 if self.feat.staged_api || self.tcx.sess.opts.unstable_opts.force_unstable_if_unmarked {
1473 if let Some(stab) = self.tcx.lookup_stability(def_id) {
1474 record!(self.tables.lookup_stability[def_id] <- stab)
1479 fn encode_const_stability(&mut self, def_id: DefId) {
1480 debug!("EncodeContext::encode_const_stability({:?})", def_id);
1482 // The query lookup can take a measurable amount of time in crates with many items. Check if
1483 // the stability attributes are even enabled before using their queries.
1484 if self.feat.staged_api || self.tcx.sess.opts.unstable_opts.force_unstable_if_unmarked {
1485 if let Some(stab) = self.tcx.lookup_const_stability(def_id) {
1486 record!(self.tables.lookup_const_stability[def_id] <- stab)
1491 fn encode_default_body_stability(&mut self, def_id: DefId) {
1492 debug!("EncodeContext::encode_default_body_stability({:?})", def_id);
1494 // The query lookup can take a measurable amount of time in crates with many items. Check if
1495 // the stability attributes are even enabled before using their queries.
1496 if self.feat.staged_api || self.tcx.sess.opts.unstable_opts.force_unstable_if_unmarked {
1497 if let Some(stab) = self.tcx.lookup_default_body_stability(def_id) {
1498 record!(self.tables.lookup_default_body_stability[def_id] <- stab)
1503 fn encode_deprecation(&mut self, def_id: DefId) {
1504 debug!("EncodeContext::encode_deprecation({:?})", def_id);
1505 if let Some(depr) = self.tcx.lookup_deprecation(def_id) {
1506 record!(self.tables.lookup_deprecation_entry[def_id] <- depr);
1510 fn encode_rendered_const_for_body(&mut self, body_id: hir::BodyId) -> String {
1511 let hir = self.tcx.hir();
1512 let body = hir.body(body_id);
1513 rustc_hir_pretty::to_string(&(&hir as &dyn intravisit::Map<'_>), |s| {
1514 s.print_expr(&body.value)
1518 fn encode_info_for_item(&mut self, def_id: DefId, item: &'tcx hir::Item<'tcx>) {
1521 debug!("EncodeContext::encode_info_for_item({:?})", def_id);
1524 hir::ItemKind::Fn(ref sig, .., body) => {
1525 self.tables.asyncness.set(def_id.index, sig.header.asyncness);
1526 record_array!(self.tables.fn_arg_names[def_id] <- self.tcx.hir().body_param_names(body));
1527 self.tables.constness.set(def_id.index, sig.header.constness);
1529 hir::ItemKind::Macro(ref macro_def, _) => {
1530 if macro_def.macro_rules {
1531 self.tables.is_macro_rules.set_nullable(def_id.index, true);
1533 record!(self.tables.macro_definition[def_id] <- &*macro_def.body);
1535 hir::ItemKind::Mod(ref m) => {
1536 return self.encode_info_for_mod(item.owner_id.def_id, m);
1538 hir::ItemKind::OpaqueTy(ref opaque) => {
1539 self.encode_explicit_item_bounds(def_id);
1540 if matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias) {
1541 self.tables.is_type_alias_impl_trait.set_nullable(def_id.index, true);
1544 hir::ItemKind::Impl(hir::Impl { defaultness, constness, .. }) => {
1545 self.tables.impl_defaultness.set(def_id.index, *defaultness);
1546 self.tables.constness.set(def_id.index, *constness);
1548 let trait_ref = self.tcx.impl_trait_ref(def_id).map(ty::EarlyBinder::skip_binder);
1549 if let Some(trait_ref) = trait_ref {
1550 let trait_def = self.tcx.trait_def(trait_ref.def_id);
1551 if let Ok(mut an) = trait_def.ancestors(self.tcx, def_id) {
1552 if let Some(specialization_graph::Node::Impl(parent)) = an.nth(1) {
1553 self.tables.impl_parent.set(def_id.index, parent.into());
1557 // if this is an impl of `CoerceUnsized`, create its
1558 // "unsized info", else just store None
1559 if Some(trait_ref.def_id) == self.tcx.lang_items().coerce_unsized_trait() {
1560 let coerce_unsized_info =
1561 self.tcx.at(item.span).coerce_unsized_info(def_id);
1562 record!(self.tables.coerce_unsized_info[def_id] <- coerce_unsized_info);
1566 let polarity = self.tcx.impl_polarity(def_id);
1567 self.tables.impl_polarity.set(def_id.index, polarity);
1569 hir::ItemKind::Trait(..) => {
1570 let trait_def = self.tcx.trait_def(def_id);
1571 record!(self.tables.trait_def[def_id] <- trait_def);
1573 hir::ItemKind::TraitAlias(..) => {
1574 let trait_def = self.tcx.trait_def(def_id);
1575 record!(self.tables.trait_def[def_id] <- trait_def);
1577 hir::ItemKind::ExternCrate(_) | hir::ItemKind::Use(..) => {
1578 bug!("cannot encode info for item {:?}", item)
1580 hir::ItemKind::Static(..)
1581 | hir::ItemKind::Const(..)
1582 | hir::ItemKind::Enum(..)
1583 | hir::ItemKind::Struct(..)
1584 | hir::ItemKind::Union(..)
1585 | hir::ItemKind::ForeignMod { .. }
1586 | hir::ItemKind::GlobalAsm(..)
1587 | hir::ItemKind::TyAlias(..) => {}
1589 // FIXME(eddyb) there should be a nicer way to do this.
1591 hir::ItemKind::Impl { .. } | hir::ItemKind::Trait(..) => {
1592 let associated_item_def_ids = self.tcx.associated_item_def_ids(def_id);
1593 record_array!(self.tables.children[def_id] <-
1594 associated_item_def_ids.iter().map(|&def_id| {
1595 assert!(def_id.is_local());
1602 if let hir::ItemKind::Fn(..) = item.kind {
1603 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1604 if tcx.is_intrinsic(def_id) {
1605 self.tables.is_intrinsic.set_nullable(def_id.index, true);
1608 if let hir::ItemKind::Impl { .. } = item.kind {
1609 if let Some(trait_ref) = self.tcx.impl_trait_ref(def_id) {
1610 record!(self.tables.impl_trait_ref[def_id] <- trait_ref);
1613 // In some cases, along with the item itself, we also
1614 // encode some sub-items. Usually we want some info from the item
1615 // so it's easier to do that here then to wait until we would encounter
1616 // normally in the visitor walk.
1618 hir::ItemKind::Impl { .. } => {
1619 for &trait_item_def_id in
1620 self.tcx.associated_item_def_ids(item.owner_id.to_def_id()).iter()
1622 self.encode_info_for_impl_item(trait_item_def_id);
1625 hir::ItemKind::Trait(..) => {
1627 self.tcx.associated_item_def_ids(item.owner_id.to_def_id()).iter()
1629 self.encode_info_for_trait_item(item_def_id);
1636 #[instrument(level = "debug", skip(self))]
1637 fn encode_info_for_closure(&mut self, def_id: LocalDefId) {
1638 // NOTE(eddyb) `tcx.type_of(def_id)` isn't used because it's fully generic,
1639 // including on the signature, which is inferred in `typeck.
1640 let typeck_result: &'tcx ty::TypeckResults<'tcx> = self.tcx.typeck(def_id);
1641 let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
1642 let ty = typeck_result.node_type(hir_id);
1644 ty::Generator(..) => {
1645 let data = self.tcx.generator_kind(def_id).unwrap();
1646 let generator_diagnostic_data = typeck_result.get_generator_diagnostic_data();
1647 record!(self.tables.generator_kind[def_id.to_def_id()] <- data);
1648 record!(self.tables.generator_diagnostic_data[def_id.to_def_id()] <- generator_diagnostic_data);
1651 ty::Closure(_, substs) => {
1652 let constness = self.tcx.constness(def_id.to_def_id());
1653 self.tables.constness.set(def_id.to_def_id().index, constness);
1654 record!(self.tables.fn_sig[def_id.to_def_id()] <- ty::EarlyBinder(substs.as_closure().sig()));
1657 _ => bug!("closure that is neither generator nor closure"),
1661 fn encode_native_libraries(&mut self) -> LazyArray<NativeLib> {
1662 empty_proc_macro!(self);
1663 let used_libraries = self.tcx.native_libraries(LOCAL_CRATE);
1664 self.lazy_array(used_libraries.iter())
1667 fn encode_foreign_modules(&mut self) -> LazyArray<ForeignModule> {
1668 empty_proc_macro!(self);
1669 let foreign_modules = self.tcx.foreign_modules(LOCAL_CRATE);
1670 self.lazy_array(foreign_modules.iter().map(|(_, m)| m).cloned())
1673 fn encode_hygiene(&mut self) -> (SyntaxContextTable, ExpnDataTable, ExpnHashTable) {
1674 let mut syntax_contexts: TableBuilder<_, _> = Default::default();
1675 let mut expn_data_table: TableBuilder<_, _> = Default::default();
1676 let mut expn_hash_table: TableBuilder<_, _> = Default::default();
1678 self.hygiene_ctxt.encode(
1679 &mut (&mut *self, &mut syntax_contexts, &mut expn_data_table, &mut expn_hash_table),
1680 |(this, syntax_contexts, _, _), index, ctxt_data| {
1681 syntax_contexts.set(index, this.lazy(ctxt_data));
1683 |(this, _, expn_data_table, expn_hash_table), index, expn_data, hash| {
1684 if let Some(index) = index.as_local() {
1685 expn_data_table.set(index.as_raw(), this.lazy(expn_data));
1686 expn_hash_table.set(index.as_raw(), this.lazy(hash));
1692 syntax_contexts.encode(&mut self.opaque),
1693 expn_data_table.encode(&mut self.opaque),
1694 expn_hash_table.encode(&mut self.opaque),
1698 fn encode_proc_macros(&mut self) -> Option<ProcMacroData> {
1699 let is_proc_macro = self.tcx.sess.crate_types().contains(&CrateType::ProcMacro);
1702 let hir = tcx.hir();
1704 let proc_macro_decls_static = tcx.proc_macro_decls_static(()).unwrap().local_def_index;
1705 let stability = tcx.lookup_stability(CRATE_DEF_ID);
1707 self.lazy_array(tcx.resolutions(()).proc_macros.iter().map(|p| p.local_def_index));
1708 let spans = self.tcx.sess.parse_sess.proc_macro_quoted_spans();
1709 for (i, span) in spans.into_iter().enumerate() {
1710 let span = self.lazy(span);
1711 self.tables.proc_macro_quoted_spans.set(i, span);
1714 self.tables.opt_def_kind.set(LOCAL_CRATE.as_def_id().index, DefKind::Mod);
1715 record!(self.tables.def_span[LOCAL_CRATE.as_def_id()] <- tcx.def_span(LOCAL_CRATE.as_def_id()));
1716 self.encode_attrs(LOCAL_CRATE.as_def_id().expect_local());
1717 let vis = tcx.local_visibility(CRATE_DEF_ID).map_id(|def_id| def_id.local_def_index);
1718 record!(self.tables.visibility[LOCAL_CRATE.as_def_id()] <- vis);
1719 if let Some(stability) = stability {
1720 record!(self.tables.lookup_stability[LOCAL_CRATE.as_def_id()] <- stability);
1722 self.encode_deprecation(LOCAL_CRATE.as_def_id());
1724 // Normally, this information is encoded when we walk the items
1725 // defined in this crate. However, we skip doing that for proc-macro crates,
1726 // so we manually encode just the information that we need
1727 for &proc_macro in &tcx.resolutions(()).proc_macros {
1728 let id = proc_macro;
1729 let proc_macro = hir.local_def_id_to_hir_id(proc_macro);
1730 let mut name = hir.name(proc_macro);
1731 let span = hir.span(proc_macro);
1732 // Proc-macros may have attributes like `#[allow_internal_unstable]`,
1733 // so downstream crates need access to them.
1734 let attrs = hir.attrs(proc_macro);
1735 let macro_kind = if tcx.sess.contains_name(attrs, sym::proc_macro) {
1737 } else if tcx.sess.contains_name(attrs, sym::proc_macro_attribute) {
1739 } else if let Some(attr) = tcx.sess.find_by_name(attrs, sym::proc_macro_derive) {
1740 // This unwrap chain should have been checked by the proc-macro harness.
1741 name = attr.meta_item_list().unwrap()[0]
1749 bug!("Unknown proc-macro type for item {:?}", id);
1752 let mut def_key = self.tcx.hir().def_key(id);
1753 def_key.disambiguated_data.data = DefPathData::MacroNs(name);
1755 let def_id = id.to_def_id();
1756 self.tables.opt_def_kind.set(def_id.index, DefKind::Macro(macro_kind));
1757 self.tables.proc_macro.set(def_id.index, macro_kind);
1758 self.encode_attrs(id);
1759 record!(self.tables.def_keys[def_id] <- def_key);
1760 record!(self.tables.def_ident_span[def_id] <- span);
1761 record!(self.tables.def_span[def_id] <- span);
1762 record!(self.tables.visibility[def_id] <- ty::Visibility::Public);
1763 if let Some(stability) = stability {
1764 record!(self.tables.lookup_stability[def_id] <- stability);
1768 Some(ProcMacroData { proc_macro_decls_static, stability, macros })
1774 fn encode_debugger_visualizers(&mut self) -> LazyArray<DebuggerVisualizerFile> {
1775 empty_proc_macro!(self);
1776 self.lazy_array(self.tcx.debugger_visualizers(LOCAL_CRATE).iter())
1779 fn encode_crate_deps(&mut self) -> LazyArray<CrateDep> {
1780 empty_proc_macro!(self);
1787 let dep = CrateDep {
1788 name: self.tcx.crate_name(cnum),
1789 hash: self.tcx.crate_hash(cnum),
1790 host_hash: self.tcx.crate_host_hash(cnum),
1791 kind: self.tcx.dep_kind(cnum),
1792 extra_filename: self.tcx.extra_filename(cnum).clone(),
1796 .collect::<Vec<_>>();
1799 // Sanity-check the crate numbers
1800 let mut expected_cnum = 1;
1801 for &(n, _) in &deps {
1802 assert_eq!(n, CrateNum::new(expected_cnum));
1807 // We're just going to write a list of crate 'name-hash-version's, with
1808 // the assumption that they are numbered 1 to n.
1809 // FIXME (#2166): This is not nearly enough to support correct versioning
1810 // but is enough to get transitive crate dependencies working.
1811 self.lazy_array(deps.iter().map(|(_, dep)| dep))
1814 fn encode_lib_features(&mut self) -> LazyArray<(Symbol, Option<Symbol>)> {
1815 empty_proc_macro!(self);
1817 let lib_features = tcx.lib_features(());
1818 self.lazy_array(lib_features.to_vec())
1821 fn encode_stability_implications(&mut self) -> LazyArray<(Symbol, Symbol)> {
1822 empty_proc_macro!(self);
1824 let implications = tcx.stability_implications(LOCAL_CRATE);
1825 self.lazy_array(implications.iter().map(|(k, v)| (*k, *v)))
1828 fn encode_diagnostic_items(&mut self) -> LazyArray<(Symbol, DefIndex)> {
1829 empty_proc_macro!(self);
1831 let diagnostic_items = &tcx.diagnostic_items(LOCAL_CRATE).name_to_id;
1832 self.lazy_array(diagnostic_items.iter().map(|(&name, def_id)| (name, def_id.index)))
1835 fn encode_lang_items(&mut self) -> LazyArray<(DefIndex, LangItem)> {
1836 empty_proc_macro!(self);
1837 let lang_items = self.tcx.lang_items().iter();
1838 self.lazy_array(lang_items.filter_map(|(lang_item, def_id)| {
1839 def_id.as_local().map(|id| (id.local_def_index, lang_item))
1843 fn encode_lang_items_missing(&mut self) -> LazyArray<LangItem> {
1844 empty_proc_macro!(self);
1846 self.lazy_array(&tcx.lang_items().missing)
1849 fn encode_traits(&mut self) -> LazyArray<DefIndex> {
1850 empty_proc_macro!(self);
1851 self.lazy_array(self.tcx.traits_in_crate(LOCAL_CRATE).iter().map(|def_id| def_id.index))
1854 /// Encodes an index, mapping each trait to its (local) implementations.
1855 fn encode_impls(&mut self) -> LazyArray<TraitImpls> {
1856 debug!("EncodeContext::encode_traits_and_impls()");
1857 empty_proc_macro!(self);
1859 let mut fx_hash_map: FxHashMap<DefId, Vec<(DefIndex, Option<SimplifiedType>)>> =
1860 FxHashMap::default();
1862 for id in tcx.hir().items() {
1863 if matches!(tcx.def_kind(id.owner_id), DefKind::Impl) {
1864 if let Some(trait_ref) = tcx.impl_trait_ref(id.owner_id) {
1865 let trait_ref = trait_ref.subst_identity();
1867 let simplified_self_ty = fast_reject::simplify_type(
1869 trait_ref.self_ty(),
1870 TreatParams::AsInfer,
1874 .entry(trait_ref.def_id)
1876 .push((id.owner_id.def_id.local_def_index, simplified_self_ty));
1881 let mut all_impls: Vec<_> = fx_hash_map.into_iter().collect();
1883 // Bring everything into deterministic order for hashing
1884 all_impls.sort_by_cached_key(|&(trait_def_id, _)| tcx.def_path_hash(trait_def_id));
1886 let all_impls: Vec<_> = all_impls
1888 .map(|(trait_def_id, mut impls)| {
1889 // Bring everything into deterministic order for hashing
1890 impls.sort_by_cached_key(|&(index, _)| {
1891 tcx.hir().def_path_hash(LocalDefId { local_def_index: index })
1895 trait_id: (trait_def_id.krate.as_u32(), trait_def_id.index),
1896 impls: self.lazy_array(&impls),
1901 self.lazy_array(&all_impls)
1904 fn encode_incoherent_impls(&mut self) -> LazyArray<IncoherentImpls> {
1905 debug!("EncodeContext::encode_traits_and_impls()");
1906 empty_proc_macro!(self);
1908 let mut all_impls: Vec<_> = tcx.crate_inherent_impls(()).incoherent_impls.iter().collect();
1909 tcx.with_stable_hashing_context(|mut ctx| {
1910 all_impls.sort_by_cached_key(|&(&simp, _)| {
1911 let mut hasher = StableHasher::new();
1912 simp.hash_stable(&mut ctx, &mut hasher);
1913 hasher.finish::<Fingerprint>()
1916 let all_impls: Vec<_> = all_impls
1918 .map(|(&simp, impls)| {
1919 let mut impls: Vec<_> =
1920 impls.into_iter().map(|def_id| def_id.local_def_index).collect();
1921 impls.sort_by_cached_key(|&local_def_index| {
1922 tcx.hir().def_path_hash(LocalDefId { local_def_index })
1925 IncoherentImpls { self_ty: simp, impls: self.lazy_array(impls) }
1929 self.lazy_array(&all_impls)
1932 // Encodes all symbols exported from this crate into the metadata.
1934 // This pass is seeded off the reachability list calculated in the
1935 // middle::reachable module but filters out items that either don't have a
1936 // symbol associated with them (they weren't translated) or if they're an FFI
1937 // definition (as that's not defined in this crate).
1938 fn encode_exported_symbols(
1940 exported_symbols: &[(ExportedSymbol<'tcx>, SymbolExportInfo)],
1941 ) -> LazyArray<(ExportedSymbol<'static>, SymbolExportInfo)> {
1942 empty_proc_macro!(self);
1943 // The metadata symbol name is special. It should not show up in
1944 // downstream crates.
1945 let metadata_symbol_name = SymbolName::new(self.tcx, &metadata_symbol_name(self.tcx));
1950 .filter(|&(exported_symbol, _)| match *exported_symbol {
1951 ExportedSymbol::NoDefId(symbol_name) => symbol_name != metadata_symbol_name,
1958 fn encode_dylib_dependency_formats(&mut self) -> LazyArray<Option<LinkagePreference>> {
1959 empty_proc_macro!(self);
1960 let formats = self.tcx.dependency_formats(());
1961 for (ty, arr) in formats.iter() {
1962 if *ty != CrateType::Dylib {
1965 return self.lazy_array(arr.iter().map(|slot| match *slot {
1966 Linkage::NotLinked | Linkage::IncludedFromDylib => None,
1968 Linkage::Dynamic => Some(LinkagePreference::RequireDynamic),
1969 Linkage::Static => Some(LinkagePreference::RequireStatic),
1975 fn encode_info_for_foreign_item(&mut self, def_id: DefId, nitem: &hir::ForeignItem<'_>) {
1978 debug!("EncodeContext::encode_info_for_foreign_item({:?})", def_id);
1981 hir::ForeignItemKind::Fn(_, ref names, _) => {
1982 self.tables.asyncness.set(def_id.index, hir::IsAsync::NotAsync);
1983 record_array!(self.tables.fn_arg_names[def_id] <- *names);
1984 let constness = if self.tcx.is_const_fn_raw(def_id) {
1985 hir::Constness::Const
1987 hir::Constness::NotConst
1989 self.tables.constness.set(def_id.index, constness);
1990 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1992 hir::ForeignItemKind::Static(..) | hir::ForeignItemKind::Type => {}
1994 if let hir::ForeignItemKind::Fn(..) = nitem.kind {
1995 if tcx.is_intrinsic(def_id) {
1996 self.tables.is_intrinsic.set_nullable(def_id.index, true);
2002 // FIXME(eddyb) make metadata encoding walk over all definitions, instead of HIR.
2003 impl<'a, 'tcx> Visitor<'tcx> for EncodeContext<'a, 'tcx> {
2004 type NestedFilter = nested_filter::OnlyBodies;
2006 fn nested_visit_map(&mut self) -> Self::Map {
2009 fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
2010 intravisit::walk_expr(self, ex);
2011 self.encode_info_for_expr(ex);
2013 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
2014 intravisit::walk_item(self, item);
2016 hir::ItemKind::ExternCrate(_) | hir::ItemKind::Use(..) => {} // ignore these
2017 _ => self.encode_info_for_item(item.owner_id.to_def_id(), item),
2020 fn visit_foreign_item(&mut self, ni: &'tcx hir::ForeignItem<'tcx>) {
2021 intravisit::walk_foreign_item(self, ni);
2022 self.encode_info_for_foreign_item(ni.owner_id.to_def_id(), ni);
2024 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
2025 intravisit::walk_generics(self, generics);
2026 self.encode_info_for_generics(generics);
2030 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
2031 fn encode_info_for_generics(&mut self, generics: &hir::Generics<'tcx>) {
2032 for param in generics.params {
2034 hir::GenericParamKind::Lifetime { .. } | hir::GenericParamKind::Type { .. } => {}
2035 hir::GenericParamKind::Const { ref default, .. } => {
2036 let def_id = param.def_id.to_def_id();
2037 if default.is_some() {
2038 record!(self.tables.const_param_default[def_id] <- self.tcx.const_param_default(def_id))
2045 fn encode_info_for_expr(&mut self, expr: &hir::Expr<'_>) {
2046 if let hir::ExprKind::Closure(closure) = expr.kind {
2047 self.encode_info_for_closure(closure.def_id);
2052 /// Used to prefetch queries which will be needed later by metadata encoding.
2053 /// Only a subset of the queries are actually prefetched to keep this code smaller.
2054 fn prefetch_mir(tcx: TyCtxt<'_>) {
2055 if !tcx.sess.opts.output_types.should_codegen() {
2056 // We won't emit MIR, so don't prefetch it.
2060 par_iter(tcx.mir_keys(())).for_each(|&def_id| {
2061 let (encode_const, encode_opt) = should_encode_mir(tcx, def_id);
2064 tcx.ensure().mir_for_ctfe(def_id);
2067 tcx.ensure().optimized_mir(def_id);
2069 if encode_opt || encode_const {
2070 tcx.ensure().promoted_mir(def_id);
2075 // NOTE(eddyb) The following comment was preserved for posterity, even
2076 // though it's no longer relevant as EBML (which uses nested & tagged
2077 // "documents") was replaced with a scheme that can't go out of bounds.
2079 // And here we run into yet another obscure archive bug: in which metadata
2080 // loaded from archives may have trailing garbage bytes. Awhile back one of
2081 // our tests was failing sporadically on the macOS 64-bit builders (both nopt
2082 // and opt) by having ebml generate an out-of-bounds panic when looking at
2085 // Upon investigation it turned out that the metadata file inside of an rlib
2086 // (and ar archive) was being corrupted. Some compilations would generate a
2087 // metadata file which would end in a few extra bytes, while other
2088 // compilations would not have these extra bytes appended to the end. These
2089 // extra bytes were interpreted by ebml as an extra tag, so they ended up
2090 // being interpreted causing the out-of-bounds.
2092 // The root cause of why these extra bytes were appearing was never
2093 // discovered, and in the meantime the solution we're employing is to insert
2094 // the length of the metadata to the start of the metadata. Later on this
2095 // will allow us to slice the metadata to the precise length that we just
2096 // generated regardless of trailing bytes that end up in it.
2098 pub struct EncodedMetadata {
2099 // The declaration order matters because `mmap` should be dropped before `_temp_dir`.
2101 // We need to carry MaybeTempDir to avoid deleting the temporary
2102 // directory while accessing the Mmap.
2103 _temp_dir: Option<MaybeTempDir>,
2106 impl EncodedMetadata {
2108 pub fn from_path(path: PathBuf, temp_dir: Option<MaybeTempDir>) -> std::io::Result<Self> {
2109 let file = std::fs::File::open(&path)?;
2110 let file_metadata = file.metadata()?;
2111 if file_metadata.len() == 0 {
2112 return Ok(Self { mmap: None, _temp_dir: None });
2114 let mmap = unsafe { Some(Mmap::map(file)?) };
2115 Ok(Self { mmap, _temp_dir: temp_dir })
2119 pub fn raw_data(&self) -> &[u8] {
2120 self.mmap.as_deref().unwrap_or_default()
2124 impl<S: Encoder> Encodable<S> for EncodedMetadata {
2125 fn encode(&self, s: &mut S) {
2126 let slice = self.raw_data();
2131 impl<D: Decoder> Decodable<D> for EncodedMetadata {
2132 fn decode(d: &mut D) -> Self {
2133 let len = d.read_usize();
2134 let mmap = if len > 0 {
2135 let mut mmap = MmapMut::map_anon(len).unwrap();
2137 (&mut mmap[..]).write(&[d.read_u8()]).unwrap();
2139 mmap.flush().unwrap();
2140 Some(mmap.make_read_only().unwrap())
2145 Self { mmap, _temp_dir: None }
2149 pub fn encode_metadata(tcx: TyCtxt<'_>, path: &Path) {
2150 let _prof_timer = tcx.prof.verbose_generic_activity("generate_crate_metadata");
2152 // Since encoding metadata is not in a query, and nothing is cached,
2153 // there's no need to do dep-graph tracking for any of it.
2154 tcx.dep_graph.assert_ignored();
2157 || encode_metadata_impl(tcx, path),
2159 if tcx.sess.threads() == 1 {
2162 // Prefetch some queries used by metadata encoding.
2163 // This is not necessary for correctness, but is only done for performance reasons.
2164 // It can be removed if it turns out to cause trouble or be detrimental to performance.
2165 join(|| prefetch_mir(tcx), || tcx.exported_symbols(LOCAL_CRATE));
2170 fn encode_metadata_impl(tcx: TyCtxt<'_>, path: &Path) {
2171 let mut encoder = opaque::FileEncoder::new(path)
2172 .unwrap_or_else(|err| tcx.sess.emit_fatal(FailCreateFileEncoder { err }));
2173 encoder.emit_raw_bytes(METADATA_HEADER);
2175 // Will be filled with the root position after encoding everything.
2176 encoder.emit_raw_bytes(&[0, 0, 0, 0]);
2178 let source_map_files = tcx.sess.source_map().files();
2179 let source_file_cache = (source_map_files[0].clone(), 0);
2180 let required_source_files = Some(FxIndexSet::default());
2181 drop(source_map_files);
2183 let hygiene_ctxt = HygieneEncodeContext::default();
2185 let mut ecx = EncodeContext {
2188 feat: tcx.features(),
2189 tables: Default::default(),
2190 lazy_state: LazyState::NoNode,
2191 type_shorthands: Default::default(),
2192 predicate_shorthands: Default::default(),
2194 interpret_allocs: Default::default(),
2195 required_source_files,
2196 is_proc_macro: tcx.sess.crate_types().contains(&CrateType::ProcMacro),
2197 hygiene_ctxt: &hygiene_ctxt,
2198 symbol_table: Default::default(),
2201 // Encode the rustc version string in a predictable location.
2202 rustc_version().encode(&mut ecx);
2204 // Encode all the entries and extra information in the crate,
2205 // culminating in the `CrateRoot` which points to all of it.
2206 let root = ecx.encode_crate_root();
2210 let mut file = ecx.opaque.file();
2211 // We will return to this position after writing the root position.
2212 let pos_before_seek = file.stream_position().unwrap();
2214 // Encode the root position.
2215 let header = METADATA_HEADER.len();
2216 file.seek(std::io::SeekFrom::Start(header as u64))
2217 .unwrap_or_else(|err| tcx.sess.emit_fatal(FailSeekFile { err }));
2218 let pos = root.position.get();
2219 file.write_all(&[(pos >> 24) as u8, (pos >> 16) as u8, (pos >> 8) as u8, (pos >> 0) as u8])
2220 .unwrap_or_else(|err| tcx.sess.emit_fatal(FailWriteFile { err }));
2222 // Return to the position where we are before writing the root position.
2223 file.seek(std::io::SeekFrom::Start(pos_before_seek)).unwrap();
2225 // Record metadata size for self-profiling
2226 tcx.prof.artifact_size(
2229 file.metadata().unwrap().len() as u64,
2233 pub fn provide(providers: &mut Providers) {
2234 *providers = Providers {
2235 traits_in_crate: |tcx, cnum| {
2236 assert_eq!(cnum, LOCAL_CRATE);
2238 let mut traits = Vec::new();
2239 for id in tcx.hir().items() {
2240 if matches!(tcx.def_kind(id.owner_id), DefKind::Trait | DefKind::TraitAlias) {
2241 traits.push(id.owner_id.to_def_id())
2245 // Bring everything into deterministic order.
2246 traits.sort_by_cached_key(|&def_id| tcx.def_path_hash(def_id));
2247 tcx.arena.alloc_slice(&traits)