1 use crate::rmeta::table::{FixedSizeEncoding, TableBuilder};
4 use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
5 use rustc_data_structures::stable_hasher::StableHasher;
6 use rustc_data_structures::sync::{join, par_iter, Lrc, ParallelIterator};
8 use rustc_hir::def::{CtorOf, DefKind};
9 use rustc_hir::def_id::{
10 CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_ID, CRATE_DEF_INDEX, LOCAL_CRATE,
12 use rustc_hir::definitions::DefPathData;
13 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
14 use rustc_hir::itemlikevisit::ItemLikeVisitor;
15 use rustc_hir::lang_items;
16 use rustc_hir::{AnonConst, GenericParamKind};
17 use rustc_index::bit_set::GrowableBitSet;
18 use rustc_index::vec::Idx;
19 use rustc_middle::hir::map::Map;
20 use rustc_middle::middle::cstore::{EncodedMetadata, ForeignModule, LinkagePreference, NativeLib};
21 use rustc_middle::middle::dependency_format::Linkage;
22 use rustc_middle::middle::exported_symbols::{
23 metadata_symbol_name, ExportedSymbol, SymbolExportLevel,
25 use rustc_middle::mir::interpret;
26 use rustc_middle::traits::specialization_graph;
27 use rustc_middle::ty::codec::TyEncoder;
28 use rustc_middle::ty::{self, SymbolName, Ty, TyCtxt};
29 use rustc_serialize::{opaque, Encodable, Encoder};
30 use rustc_session::config::CrateType;
31 use rustc_span::symbol::{sym, Ident, Symbol};
32 use rustc_span::{self, ExternalSource, FileName, SourceFile, Span, SyntaxContext};
34 hygiene::{ExpnDataEncodeMode, HygieneEncodeContext, MacroKind},
37 use rustc_target::abi::VariantIdx;
39 use std::num::NonZeroUsize;
41 use tracing::{debug, trace};
43 pub(super) struct EncodeContext<'a, 'tcx> {
44 opaque: opaque::Encoder,
46 feat: &'tcx rustc_feature::Features,
48 tables: TableBuilders<'tcx>,
50 lazy_state: LazyState,
51 type_shorthands: FxHashMap<Ty<'tcx>, usize>,
52 predicate_shorthands: FxHashMap<ty::PredicateKind<'tcx>, usize>,
54 interpret_allocs: FxIndexSet<interpret::AllocId>,
56 // This is used to speed up Span encoding.
57 // The `usize` is an index into the `MonotonicVec`
58 // that stores the `SourceFile`
59 source_file_cache: (Lrc<SourceFile>, usize),
60 // The indices (into the `SourceMap`'s `MonotonicVec`)
61 // of all of the `SourceFiles` that we need to serialize.
62 // When we serialize a `Span`, we insert the index of its
63 // `SourceFile` into the `GrowableBitSet`.
65 // This needs to be a `GrowableBitSet` and not a
66 // regular `BitSet` because we may actually import new `SourceFiles`
67 // during metadata encoding, due to executing a query
68 // with a result containing a foreign `Span`.
69 required_source_files: Option<GrowableBitSet<usize>>,
71 hygiene_ctxt: &'a HygieneEncodeContext,
74 /// If the current crate is a proc-macro, returns early with `Lazy:empty()`.
75 /// This is useful for skipping the encoding of things that aren't needed
76 /// for proc-macro crates.
77 macro_rules! empty_proc_macro {
79 if $self.is_proc_macro {
85 macro_rules! encoder_methods {
86 ($($name:ident($ty:ty);)*) => {
87 $(fn $name(&mut self, value: $ty) -> Result<(), Self::Error> {
88 self.opaque.$name(value)
93 impl<'a, 'tcx> Encoder for EncodeContext<'a, 'tcx> {
94 type Error = <opaque::Encoder as Encoder>::Error;
97 fn emit_unit(&mut self) -> Result<(), Self::Error> {
121 emit_raw_bytes(&[u8]);
125 impl<'a, 'tcx, T: Encodable<EncodeContext<'a, 'tcx>>> Encodable<EncodeContext<'a, 'tcx>>
128 fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
129 e.emit_lazy_distance(*self)
133 impl<'a, 'tcx, T: Encodable<EncodeContext<'a, 'tcx>>> Encodable<EncodeContext<'a, 'tcx>>
136 fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
137 e.emit_usize(self.meta)?;
141 e.emit_lazy_distance(*self)
145 impl<'a, 'tcx, I: Idx, T: Encodable<EncodeContext<'a, 'tcx>>> Encodable<EncodeContext<'a, 'tcx>>
146 for Lazy<Table<I, T>>
148 Option<T>: FixedSizeEncoding,
150 fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
151 e.emit_usize(self.meta)?;
152 e.emit_lazy_distance(*self)
156 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for CrateNum {
157 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
158 if *self != LOCAL_CRATE && s.is_proc_macro {
159 panic!("Attempted to encode non-local CrateNum {:?} for proc-macro crate", self);
161 s.emit_u32(self.as_u32())
165 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for DefIndex {
166 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
167 s.emit_u32(self.as_u32())
171 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for SyntaxContext {
172 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
173 rustc_span::hygiene::raw_encode_syntax_context(*self, &s.hygiene_ctxt, s)
177 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for ExpnId {
178 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
179 rustc_span::hygiene::raw_encode_expn_id(
182 ExpnDataEncodeMode::Metadata,
188 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
189 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
190 let span = self.data();
192 // Don't serialize any `SyntaxContext`s from a proc-macro crate,
193 // since we don't load proc-macro dependencies during serialization.
194 // This means that any hygiene information from macros used *within*
195 // a proc-macro crate (e.g. invoking a macro that expands to a proc-macro
196 // definition) will be lost.
198 // This can show up in two ways:
200 // 1. Any hygiene information associated with identifier of
201 // a proc macro (e.g. `#[proc_macro] pub fn $name`) will be lost.
202 // Since proc-macros can only be invoked from a different crate,
203 // real code should never need to care about this.
205 // 2. Using `Span::def_site` or `Span::mixed_site` will not
206 // include any hygiene information associated with the definition
207 // site. This means that a proc-macro cannot emit a `$crate`
208 // identifier which resolves to one of its dependencies,
209 // which also should never come up in practice.
211 // Additionally, this affects `Span::parent`, and any other
212 // span inspection APIs that would otherwise allow traversing
213 // the `SyntaxContexts` associated with a span.
215 // None of these user-visible effects should result in any
216 // cross-crate inconsistencies (getting one behavior in the same
217 // crate, and a different behavior in another crate) due to the
218 // limited surface that proc-macros can expose.
220 // IMPORTANT: If this is ever changed, be sure to update
221 // `rustc_span::hygiene::raw_encode_expn_id` to handle
222 // encoding `ExpnData` for proc-macro crates.
224 SyntaxContext::root().encode(s)?;
226 span.ctxt.encode(s)?;
230 return TAG_PARTIAL_SPAN.encode(s);
233 // The Span infrastructure should make sure that this invariant holds:
234 debug_assert!(span.lo <= span.hi);
236 if !s.source_file_cache.0.contains(span.lo) {
237 let source_map = s.tcx.sess.source_map();
238 let source_file_index = source_map.lookup_source_file_idx(span.lo);
239 s.source_file_cache =
240 (source_map.files()[source_file_index].clone(), source_file_index);
243 if !s.source_file_cache.0.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 let source_files = s.required_source_files.as_mut().expect("Already encoded SourceMap!");
250 // Record the fact that we need to encode the data for this `SourceFile`
251 source_files.insert(s.source_file_cache.1);
253 // There are two possible cases here:
254 // 1. This span comes from a 'foreign' crate - e.g. some crate upstream of the
255 // crate we are writing metadata for. When the metadata for *this* crate gets
256 // deserialized, the deserializer will need to know which crate it originally came
257 // from. We use `TAG_VALID_SPAN_FOREIGN` to indicate that a `CrateNum` should
258 // be deserialized after the rest of the span data, which tells the deserializer
259 // which crate contains the source map information.
260 // 2. This span comes from our own crate. No special hamdling is needed - we just
261 // write `TAG_VALID_SPAN_LOCAL` to let the deserializer know that it should use
262 // our own source map information.
264 // If we're a proc-macro crate, we always treat this as a local `Span`.
265 // In `encode_source_map`, we serialize foreign `SourceFile`s into our metadata
266 // if we're a proc-macro crate.
267 // This allows us to avoid loading the dependencies of proc-macro crates: all of
268 // the information we need to decode `Span`s is stored in the proc-macro crate.
269 let (tag, lo, hi) = if s.source_file_cache.0.is_imported() && !s.is_proc_macro {
270 // To simplify deserialization, we 'rebase' this span onto the crate it originally came from
271 // (the crate that 'owns' the file it references. These rebased 'lo' and 'hi' values
272 // are relative to the source map information for the 'foreign' crate whose CrateNum
273 // we write into the metadata. This allows `imported_source_files` to binary
274 // search through the 'foreign' crate's source map information, using the
275 // deserialized 'lo' and 'hi' values directly.
277 // All of this logic ensures that the final result of deserialization is a 'normal'
278 // Span that can be used without any additional trouble.
279 let external_start_pos = {
280 // Introduce a new scope so that we drop the 'lock()' temporary
281 match &*s.source_file_cache.0.external_src.lock() {
282 ExternalSource::Foreign { original_start_pos, .. } => *original_start_pos,
283 src => panic!("Unexpected external source {:?}", src),
286 let lo = (span.lo - s.source_file_cache.0.start_pos) + external_start_pos;
287 let hi = (span.hi - s.source_file_cache.0.start_pos) + external_start_pos;
289 (TAG_VALID_SPAN_FOREIGN, lo, hi)
291 (TAG_VALID_SPAN_LOCAL, span.lo, span.hi)
297 // Encode length which is usually less than span.hi and profits more
298 // from the variable-length integer encoding that we use.
302 if tag == TAG_VALID_SPAN_FOREIGN {
303 // This needs to be two lines to avoid holding the `s.source_file_cache`
304 // while calling `cnum.encode(s)`
305 let cnum = s.source_file_cache.0.cnum;
313 impl<'a, 'tcx> TyEncoder<'tcx> for EncodeContext<'a, 'tcx> {
314 const CLEAR_CROSS_CRATE: bool = true;
316 fn position(&self) -> usize {
317 self.opaque.position()
320 fn type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize> {
321 &mut self.type_shorthands
324 fn predicate_shorthands(&mut self) -> &mut FxHashMap<ty::PredicateKind<'tcx>, usize> {
325 &mut self.predicate_shorthands
330 alloc_id: &rustc_middle::mir::interpret::AllocId,
331 ) -> Result<(), Self::Error> {
332 let (index, _) = self.interpret_allocs.insert_full(*alloc_id);
338 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for &'tcx [mir::abstract_const::Node<'tcx>] {
339 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
344 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for &'tcx [(ty::Predicate<'tcx>, Span)] {
345 fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
350 /// Helper trait to allow overloading `EncodeContext::lazy` for iterators.
351 trait EncodeContentsForLazy<'a, 'tcx, T: ?Sized + LazyMeta> {
352 fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) -> T::Meta;
355 impl<'a, 'tcx, T: Encodable<EncodeContext<'a, 'tcx>>> EncodeContentsForLazy<'a, 'tcx, T> for &T {
356 fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) {
357 self.encode(ecx).unwrap()
361 impl<'a, 'tcx, T: Encodable<EncodeContext<'a, 'tcx>>> EncodeContentsForLazy<'a, 'tcx, T> for T {
362 fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) {
363 self.encode(ecx).unwrap()
367 impl<'a, 'tcx, I, T: Encodable<EncodeContext<'a, 'tcx>>> EncodeContentsForLazy<'a, 'tcx, [T]> for I
370 I::Item: EncodeContentsForLazy<'a, 'tcx, T>,
372 fn encode_contents_for_lazy(self, ecx: &mut EncodeContext<'a, 'tcx>) -> usize {
373 self.into_iter().map(|value| value.encode_contents_for_lazy(ecx)).count()
377 // Shorthand for `$self.$tables.$table.set($def_id.index, $self.lazy($value))`, which would
378 // normally need extra variables to avoid errors about multiple mutable borrows.
379 macro_rules! record {
380 ($self:ident.$tables:ident.$table:ident[$def_id:expr] <- $value:expr) => {{
383 let lazy = $self.lazy(value);
384 $self.$tables.$table.set($def_id.index, lazy);
389 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
390 fn emit_lazy_distance<T: ?Sized + LazyMeta>(
393 ) -> Result<(), <Self as Encoder>::Error> {
394 let min_end = lazy.position.get() + T::min_size(lazy.meta);
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!(min_end <= start);
402 LazyState::Previous(last_min_end) => {
404 last_min_end <= lazy.position,
405 "make sure that the calls to `lazy*` \
406 are in the same order as the metadata fields",
408 lazy.position.get() - last_min_end.get()
411 self.lazy_state = LazyState::Previous(NonZeroUsize::new(min_end).unwrap());
412 self.emit_usize(distance)
415 fn lazy<T: ?Sized + LazyMeta>(
417 value: impl EncodeContentsForLazy<'a, 'tcx, T>,
419 let pos = NonZeroUsize::new(self.position()).unwrap();
421 assert_eq!(self.lazy_state, LazyState::NoNode);
422 self.lazy_state = LazyState::NodeStart(pos);
423 let meta = value.encode_contents_for_lazy(self);
424 self.lazy_state = LazyState::NoNode;
426 assert!(pos.get() + <T>::min_size(meta) <= self.position());
428 Lazy::from_position_and_meta(pos, meta)
431 fn encode_info_for_items(&mut self) {
432 let krate = self.tcx.hir().krate();
433 self.encode_info_for_mod(CRATE_DEF_ID, &krate.item);
435 // Proc-macro crates only export proc-macro items, which are looked
436 // up using `proc_macro_data`
437 if self.is_proc_macro {
441 krate.visit_all_item_likes(&mut self.as_deep_visitor());
442 for macro_def in krate.exported_macros {
443 self.visit_macro_def(macro_def);
447 fn encode_def_path_table(&mut self) {
448 let table = self.tcx.resolutions(()).definitions.def_path_table();
449 if self.is_proc_macro {
450 for def_index in std::iter::once(CRATE_DEF_INDEX)
451 .chain(self.tcx.hir().krate().proc_macros.iter().map(|p| p.owner.local_def_index))
453 let def_key = self.lazy(table.def_key(def_index));
454 let def_path_hash = self.lazy(table.def_path_hash(def_index));
455 self.tables.def_keys.set(def_index, def_key);
456 self.tables.def_path_hashes.set(def_index, def_path_hash);
459 for (def_index, def_key, def_path_hash) in table.enumerated_keys_and_path_hashes() {
460 let def_key = self.lazy(def_key);
461 let def_path_hash = self.lazy(def_path_hash);
462 self.tables.def_keys.set(def_index, def_key);
463 self.tables.def_path_hashes.set(def_index, def_path_hash);
468 fn encode_source_map(&mut self) -> Lazy<[rustc_span::SourceFile]> {
469 let source_map = self.tcx.sess.source_map();
470 let all_source_files = source_map.files();
472 // By replacing the `Option` with `None`, we ensure that we can't
473 // accidentally serialize any more `Span`s after the source map encoding
475 let required_source_files = self.required_source_files.take().unwrap();
477 let adapted = all_source_files
480 .filter(|(idx, source_file)| {
481 // Only serialize `SourceFile`s that were used
482 // during the encoding of a `Span`
483 required_source_files.contains(*idx) &&
484 // Don't serialize imported `SourceFile`s, unless
485 // we're in a proc-macro crate.
486 (!source_file.is_imported() || self.is_proc_macro)
488 .map(|(_, source_file)| {
489 let mut adapted = match source_file.name {
490 FileName::Real(ref realname) => {
491 let mut adapted = (**source_file).clone();
492 adapted.name = FileName::Real(match realname {
493 RealFileName::LocalPath(path_to_file) => {
494 // Prepend path of working directory onto potentially
495 // relative paths, because they could become relative
496 // to a wrong directory.
497 let working_dir = &self.tcx.sess.working_dir;
499 RealFileName::LocalPath(absolute) => {
500 // If working_dir has not been remapped, then we emit a
501 // LocalPath variant as it's likely to be a valid path
502 RealFileName::LocalPath(
503 Path::new(absolute).join(path_to_file),
506 RealFileName::Remapped { local_path: _, virtual_name } => {
507 // If working_dir has been remapped, then we emit
508 // Remapped variant as the expanded path won't be valid
509 RealFileName::Remapped {
511 virtual_name: Path::new(virtual_name)
517 RealFileName::Remapped { local_path: _, virtual_name } => {
518 RealFileName::Remapped {
519 // We do not want any local path to be exported into metadata
521 virtual_name: virtual_name.clone(),
525 adapted.name_hash = {
526 let mut hasher: StableHasher = StableHasher::new();
527 adapted.name.hash(&mut hasher);
528 hasher.finish::<u128>()
533 // expanded code, not from a file
534 _ => source_file.clone(),
537 // We're serializing this `SourceFile` into our crate metadata,
538 // so mark it as coming from this crate.
539 // This also ensures that we don't try to deserialize the
540 // `CrateNum` for a proc-macro dependency - since proc macro
541 // dependencies aren't loaded when we deserialize a proc-macro,
542 // trying to remap the `CrateNum` would fail.
543 if self.is_proc_macro {
544 Lrc::make_mut(&mut adapted).cnum = LOCAL_CRATE;
548 .collect::<Vec<_>>();
550 self.lazy(adapted.iter().map(|rc| &**rc))
553 fn encode_crate_root(&mut self) -> Lazy<CrateRoot<'tcx>> {
554 let mut i = self.position();
556 // Encode the crate deps
557 let crate_deps = self.encode_crate_deps();
558 let dylib_dependency_formats = self.encode_dylib_dependency_formats();
559 let dep_bytes = self.position() - i;
561 // Encode the lib features.
563 let lib_features = self.encode_lib_features();
564 let lib_feature_bytes = self.position() - i;
566 // Encode the language items.
568 let lang_items = self.encode_lang_items();
569 let lang_items_missing = self.encode_lang_items_missing();
570 let lang_item_bytes = self.position() - i;
572 // Encode the diagnostic items.
574 let diagnostic_items = self.encode_diagnostic_items();
575 let diagnostic_item_bytes = self.position() - i;
577 // Encode the native libraries used
579 let native_libraries = self.encode_native_libraries();
580 let native_lib_bytes = self.position() - i;
582 let foreign_modules = self.encode_foreign_modules();
584 // Encode DefPathTable
586 self.encode_def_path_table();
587 let def_path_table_bytes = self.position() - i;
589 // Encode the def IDs of impls, for coherence checking.
591 let impls = self.encode_impls();
592 let impl_bytes = self.position() - i;
599 let mir_bytes = self.position() - i;
603 self.encode_def_ids();
604 self.encode_info_for_items();
605 let item_bytes = self.position() - i;
607 // Encode the allocation index
608 let 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).unwrap();
628 self.lazy(interpret_alloc_index)
631 // Encode the proc macro data. This affects 'tables',
632 // so we need to do this before we encode the tables
634 let proc_macro_data = self.encode_proc_macros();
635 let proc_macro_data_bytes = self.position() - i;
638 let tables = self.tables.encode(&mut self.opaque);
639 let tables_bytes = self.position() - i;
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.
644 let exported_symbols = tcx.exported_symbols(LOCAL_CRATE);
645 let exported_symbols = self.encode_exported_symbols(&exported_symbols);
646 let exported_symbols_bytes = self.position() - i;
648 // Encode the hygiene data,
649 // IMPORTANT: this *must* be the last thing that we encode (other than `SourceMap`). The process
650 // of encoding other items (e.g. `optimized_mir`) may cause us to load
651 // data from the incremental cache. If this causes us to deserialize a `Span`,
652 // then we may load additional `SyntaxContext`s into the global `HygieneData`.
653 // Therefore, we need to encode the hygiene data last to ensure that we encode
654 // any `SyntaxContext`s that might be used.
656 let (syntax_contexts, expn_data, expn_hashes) = self.encode_hygiene();
657 let hygiene_bytes = self.position() - i;
659 // Encode source_map. This needs to be done last,
660 // since encoding `Span`s tells us which `SourceFiles` we actually
663 let source_map = self.encode_source_map();
664 let source_map_bytes = self.position() - i;
666 let attrs = tcx.hir().krate_attrs();
667 let has_default_lib_allocator = tcx.sess.contains_name(&attrs, sym::default_lib_allocator);
669 let root = self.lazy(CrateRoot {
670 name: tcx.crate_name(LOCAL_CRATE),
671 extra_filename: tcx.sess.opts.cg.extra_filename.clone(),
672 triple: tcx.sess.opts.target_triple.clone(),
673 hash: tcx.crate_hash(LOCAL_CRATE),
674 stable_crate_id: tcx.def_path_hash(LOCAL_CRATE.as_def_id()).stable_crate_id(),
675 panic_strategy: tcx.sess.panic_strategy(),
676 edition: tcx.sess.edition(),
677 has_global_allocator: tcx.has_global_allocator(LOCAL_CRATE),
678 has_panic_handler: tcx.has_panic_handler(LOCAL_CRATE),
679 has_default_lib_allocator,
681 compiler_builtins: tcx.sess.contains_name(&attrs, sym::compiler_builtins),
682 needs_allocator: tcx.sess.contains_name(&attrs, sym::needs_allocator),
683 needs_panic_runtime: tcx.sess.contains_name(&attrs, sym::needs_panic_runtime),
684 no_builtins: tcx.sess.contains_name(&attrs, sym::no_builtins),
685 panic_runtime: tcx.sess.contains_name(&attrs, sym::panic_runtime),
686 profiler_runtime: tcx.sess.contains_name(&attrs, sym::profiler_runtime),
687 symbol_mangling_version: tcx.sess.opts.debugging_opts.get_symbol_mangling_version(),
690 dylib_dependency_formats,
700 interpret_alloc_index,
707 let total_bytes = self.position();
709 if tcx.sess.meta_stats() {
710 let mut zero_bytes = 0;
711 for e in self.opaque.data.iter() {
717 eprintln!("metadata stats:");
718 eprintln!(" dep bytes: {}", dep_bytes);
719 eprintln!(" lib feature bytes: {}", lib_feature_bytes);
720 eprintln!(" lang item bytes: {}", lang_item_bytes);
721 eprintln!(" diagnostic item bytes: {}", diagnostic_item_bytes);
722 eprintln!(" native bytes: {}", native_lib_bytes);
723 eprintln!(" source_map bytes: {}", source_map_bytes);
724 eprintln!(" impl bytes: {}", impl_bytes);
725 eprintln!(" exp. symbols bytes: {}", exported_symbols_bytes);
726 eprintln!(" def-path table bytes: {}", def_path_table_bytes);
727 eprintln!(" proc-macro-data-bytes: {}", proc_macro_data_bytes);
728 eprintln!(" mir bytes: {}", mir_bytes);
729 eprintln!(" item bytes: {}", item_bytes);
730 eprintln!(" table bytes: {}", tables_bytes);
731 eprintln!(" hygiene bytes: {}", hygiene_bytes);
732 eprintln!(" zero bytes: {}", zero_bytes);
733 eprintln!(" total bytes: {}", total_bytes);
740 fn should_encode_visibility(def_kind: DefKind) -> bool {
750 | DefKind::TraitAlias
757 | DefKind::AssocConst
760 | DefKind::ForeignMod
763 | DefKind::Field => true,
765 | DefKind::ConstParam
766 | DefKind::LifetimeParam
771 | DefKind::ExternCrate => false,
775 fn should_encode_stability(def_kind: DefKind) -> bool {
784 | DefKind::AssocConst
786 | DefKind::ConstParam
790 | DefKind::ForeignMod
797 | DefKind::TraitAlias
799 | DefKind::ForeignTy => true,
801 | DefKind::LifetimeParam
806 | DefKind::ExternCrate => false,
810 /// Whether we should encode MIR.
812 /// Computing, optimizing and encoding the MIR is a relatively expensive operation.
813 /// We want to avoid this work when not required. Therefore:
814 /// - we only compute `mir_for_ctfe` on items with const-eval semantics;
815 /// - we skip `optimized_mir` for check runs.
817 /// Return a pair, resp. for CTFE and for LLVM.
818 fn should_encode_mir(tcx: TyCtxt<'_>, def_id: LocalDefId) -> (bool, bool) {
819 match tcx.def_kind(def_id) {
821 DefKind::Ctor(_, _) => {
822 let mir_opt_base = tcx.sess.opts.output_types.should_codegen()
823 || tcx.sess.opts.debugging_opts.always_encode_mir;
827 DefKind::AnonConst | DefKind::AssocConst | DefKind::Static | DefKind::Const => {
830 // Full-fledged functions
831 DefKind::AssocFn | DefKind::Fn => {
832 let generics = tcx.generics_of(def_id);
833 let needs_inline = (generics.requires_monomorphization(tcx)
834 || tcx.codegen_fn_attrs(def_id).requests_inline())
835 && tcx.sess.opts.output_types.should_codegen();
836 // Only check the presence of the `const` modifier.
837 let is_const_fn = tcx.is_const_fn_raw(def_id.to_def_id());
838 let always_encode_mir = tcx.sess.opts.debugging_opts.always_encode_mir;
839 (is_const_fn, needs_inline || always_encode_mir)
841 // Closures can't be const fn.
842 DefKind::Closure => {
843 let generics = tcx.generics_of(def_id);
844 let needs_inline = (generics.requires_monomorphization(tcx)
845 || tcx.codegen_fn_attrs(def_id).requests_inline())
846 && tcx.sess.opts.output_types.should_codegen();
847 let always_encode_mir = tcx.sess.opts.debugging_opts.always_encode_mir;
848 (false, needs_inline || always_encode_mir)
850 // Generators require optimized MIR to compute layout.
851 DefKind::Generator => (false, true),
852 // The others don't have MIR.
857 fn should_encode_variances(def_kind: DefKind) -> bool {
865 | DefKind::AssocFn => true,
869 | DefKind::AssocConst
871 | DefKind::ConstParam
874 | DefKind::ForeignMod
879 | DefKind::TraitAlias
883 | DefKind::LifetimeParam
888 | DefKind::ExternCrate => false,
892 fn should_encode_generics(def_kind: DefKind) -> bool {
901 | DefKind::TraitAlias
908 | DefKind::AssocConst
913 | DefKind::Generator => true,
916 | DefKind::ForeignMod
918 | DefKind::ConstParam
921 | DefKind::LifetimeParam
923 | DefKind::ExternCrate => false,
927 impl EncodeContext<'a, 'tcx> {
928 fn encode_def_ids(&mut self) {
929 if self.is_proc_macro {
934 for local_id in hir.iter_local_def_id() {
935 let def_id = local_id.to_def_id();
936 let def_kind = tcx.opt_def_kind(local_id);
937 let def_kind = if let Some(def_kind) = def_kind { def_kind } else { continue };
938 record!(self.tables.def_kind[def_id] <- match def_kind {
939 // Replace Ctor by the enclosing object to avoid leaking details in children crates.
940 DefKind::Ctor(CtorOf::Struct, _) => DefKind::Struct,
941 DefKind::Ctor(CtorOf::Variant, _) => DefKind::Variant,
942 def_kind => def_kind,
944 record!(self.tables.span[def_id] <- tcx.def_span(def_id));
945 record!(self.tables.attributes[def_id] <- tcx.get_attrs(def_id));
946 record!(self.tables.expn_that_defined[def_id] <- self.tcx.expn_that_defined(def_id));
947 if should_encode_visibility(def_kind) {
948 record!(self.tables.visibility[def_id] <- self.tcx.visibility(def_id));
950 if should_encode_stability(def_kind) {
951 self.encode_stability(def_id);
952 self.encode_const_stability(def_id);
953 self.encode_deprecation(def_id);
955 if should_encode_variances(def_kind) {
956 let v = self.tcx.variances_of(def_id);
957 record!(self.tables.variances[def_id] <- v);
959 if should_encode_generics(def_kind) {
960 let g = tcx.generics_of(def_id);
961 record!(self.tables.generics[def_id] <- g);
962 record!(self.tables.explicit_predicates[def_id] <- self.tcx.explicit_predicates_of(def_id));
963 let inferred_outlives = self.tcx.inferred_outlives_of(def_id);
964 if !inferred_outlives.is_empty() {
965 record!(self.tables.inferred_outlives[def_id] <- inferred_outlives);
968 if let DefKind::Trait | DefKind::TraitAlias = def_kind {
969 record!(self.tables.super_predicates[def_id] <- self.tcx.super_predicates_of(def_id));
972 let inherent_impls = tcx.crate_inherent_impls(());
973 for (def_id, implementations) in inherent_impls.inherent_impls.iter() {
974 if implementations.is_empty() {
977 record!(self.tables.inherent_impls[def_id.to_def_id()] <- implementations.iter().map(|&def_id| {
978 assert!(def_id.is_local());
984 fn encode_item_type(&mut self, def_id: DefId) {
985 debug!("EncodeContext::encode_item_type({:?})", def_id);
986 record!(self.tables.ty[def_id] <- self.tcx.type_of(def_id));
989 fn encode_enum_variant_info(&mut self, def: &ty::AdtDef, index: VariantIdx) {
991 let variant = &def.variants[index];
992 let def_id = variant.def_id;
993 debug!("EncodeContext::encode_enum_variant_info({:?})", def_id);
995 let data = VariantData {
996 ctor_kind: variant.ctor_kind,
997 discr: variant.discr,
998 ctor: variant.ctor_def_id.map(|did| did.index),
999 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
1002 record!(self.tables.kind[def_id] <- EntryKind::Variant(self.lazy(data)));
1003 record!(self.tables.children[def_id] <- variant.fields.iter().map(|f| {
1004 assert!(f.did.is_local());
1007 self.encode_ident_span(def_id, variant.ident);
1008 self.encode_item_type(def_id);
1009 if variant.ctor_kind == CtorKind::Fn {
1010 // FIXME(eddyb) encode signature only in `encode_enum_variant_ctor`.
1011 if let Some(ctor_def_id) = variant.ctor_def_id {
1012 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(ctor_def_id));
1017 fn encode_enum_variant_ctor(&mut self, def: &ty::AdtDef, index: VariantIdx) {
1019 let variant = &def.variants[index];
1020 let def_id = variant.ctor_def_id.unwrap();
1021 debug!("EncodeContext::encode_enum_variant_ctor({:?})", def_id);
1023 // FIXME(eddyb) encode only the `CtorKind` for constructors.
1024 let data = VariantData {
1025 ctor_kind: variant.ctor_kind,
1026 discr: variant.discr,
1027 ctor: Some(def_id.index),
1028 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
1031 record!(self.tables.kind[def_id] <- EntryKind::Variant(self.lazy(data)));
1032 self.encode_item_type(def_id);
1033 if variant.ctor_kind == CtorKind::Fn {
1034 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1038 fn encode_info_for_mod(&mut self, local_def_id: LocalDefId, md: &hir::Mod<'_>) {
1040 let def_id = local_def_id.to_def_id();
1041 debug!("EncodeContext::encode_info_for_mod({:?})", def_id);
1043 // If we are encoding a proc-macro crates, `encode_info_for_mod` will
1044 // only ever get called for the crate root. We still want to encode
1045 // the crate root for consistency with other crates (some of the resolver
1046 // code uses it). However, we skip encoding anything relating to child
1047 // items - we encode information about proc-macros later on.
1048 let reexports = if !self.is_proc_macro {
1049 match tcx.module_exports(local_def_id) {
1051 let hir = self.tcx.hir();
1055 .map(|export| export.map_id(|id| hir.local_def_id_to_hir_id(id))),
1064 let data = ModData { reexports, expansion: tcx.expn_that_defined(local_def_id) };
1066 record!(self.tables.kind[def_id] <- EntryKind::Mod(self.lazy(data)));
1067 if self.is_proc_macro {
1068 record!(self.tables.children[def_id] <- &[]);
1070 record!(self.tables.children[def_id] <- md.item_ids.iter().map(|item_id| {
1071 item_id.def_id.local_def_index
1078 adt_def: &ty::AdtDef,
1079 variant_index: VariantIdx,
1082 let variant = &adt_def.variants[variant_index];
1083 let field = &variant.fields[field_index];
1085 let def_id = field.did;
1086 debug!("EncodeContext::encode_field({:?})", def_id);
1088 record!(self.tables.kind[def_id] <- EntryKind::Field);
1089 self.encode_ident_span(def_id, field.ident);
1090 self.encode_item_type(def_id);
1093 fn encode_struct_ctor(&mut self, adt_def: &ty::AdtDef, def_id: DefId) {
1094 debug!("EncodeContext::encode_struct_ctor({:?})", def_id);
1096 let variant = adt_def.non_enum_variant();
1098 let data = VariantData {
1099 ctor_kind: variant.ctor_kind,
1100 discr: variant.discr,
1101 ctor: Some(def_id.index),
1102 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
1105 record!(self.tables.kind[def_id] <- EntryKind::Struct(self.lazy(data), adt_def.repr));
1106 self.encode_item_type(def_id);
1107 if variant.ctor_kind == CtorKind::Fn {
1108 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1112 fn encode_explicit_item_bounds(&mut self, def_id: DefId) {
1113 debug!("EncodeContext::encode_explicit_item_bounds({:?})", def_id);
1114 let bounds = self.tcx.explicit_item_bounds(def_id);
1115 if !bounds.is_empty() {
1116 record!(self.tables.explicit_item_bounds[def_id] <- bounds);
1120 fn encode_info_for_trait_item(&mut self, def_id: DefId) {
1121 debug!("EncodeContext::encode_info_for_trait_item({:?})", def_id);
1124 let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
1125 let ast_item = tcx.hir().expect_trait_item(hir_id);
1126 let trait_item = tcx.associated_item(def_id);
1128 let container = match trait_item.defaultness {
1129 hir::Defaultness::Default { has_value: true } => AssocContainer::TraitWithDefault,
1130 hir::Defaultness::Default { has_value: false } => AssocContainer::TraitRequired,
1131 hir::Defaultness::Final => span_bug!(ast_item.span, "traits cannot have final items"),
1134 match trait_item.kind {
1135 ty::AssocKind::Const => {
1136 let rendered = rustc_hir_pretty::to_string(
1137 &(&self.tcx.hir() as &dyn intravisit::Map<'_>),
1138 |s| s.print_trait_item(ast_item),
1140 let rendered_const = self.lazy(RenderedConst(rendered));
1142 record!(self.tables.kind[def_id] <- EntryKind::AssocConst(
1148 ty::AssocKind::Fn => {
1149 let fn_data = if let hir::TraitItemKind::Fn(m_sig, m) = &ast_item.kind {
1150 let param_names = match *m {
1151 hir::TraitFn::Required(ref names) => self.encode_fn_param_names(names),
1152 hir::TraitFn::Provided(body) => self.encode_fn_param_names_for_body(body),
1155 asyncness: m_sig.header.asyncness,
1156 constness: hir::Constness::NotConst,
1162 record!(self.tables.kind[def_id] <- EntryKind::AssocFn(self.lazy(AssocFnData {
1165 has_self: trait_item.fn_has_self_parameter,
1168 ty::AssocKind::Type => {
1169 self.encode_explicit_item_bounds(def_id);
1170 record!(self.tables.kind[def_id] <- EntryKind::AssocType(container));
1173 self.encode_ident_span(def_id, ast_item.ident);
1174 match trait_item.kind {
1175 ty::AssocKind::Const | ty::AssocKind::Fn => {
1176 self.encode_item_type(def_id);
1178 ty::AssocKind::Type => {
1179 if trait_item.defaultness.has_value() {
1180 self.encode_item_type(def_id);
1184 if trait_item.kind == ty::AssocKind::Fn {
1185 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1189 fn encode_info_for_impl_item(&mut self, def_id: DefId) {
1190 debug!("EncodeContext::encode_info_for_impl_item({:?})", def_id);
1193 let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
1194 let ast_item = self.tcx.hir().expect_impl_item(hir_id);
1195 let impl_item = self.tcx.associated_item(def_id);
1197 let container = match impl_item.defaultness {
1198 hir::Defaultness::Default { has_value: true } => AssocContainer::ImplDefault,
1199 hir::Defaultness::Final => AssocContainer::ImplFinal,
1200 hir::Defaultness::Default { has_value: false } => {
1201 span_bug!(ast_item.span, "impl items always have values (currently)")
1205 match impl_item.kind {
1206 ty::AssocKind::Const => {
1207 if let hir::ImplItemKind::Const(_, body_id) = ast_item.kind {
1208 let qualifs = self.tcx.at(ast_item.span).mir_const_qualif(def_id);
1210 record!(self.tables.kind[def_id] <- EntryKind::AssocConst(
1213 self.encode_rendered_const_for_body(body_id))
1219 ty::AssocKind::Fn => {
1220 let fn_data = if let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind {
1222 asyncness: sig.header.asyncness,
1223 // Can be inside `impl const Trait`, so using sig.header.constness is not reliable
1224 constness: if self.tcx.is_const_fn_raw(def_id) {
1225 hir::Constness::Const
1227 hir::Constness::NotConst
1229 param_names: self.encode_fn_param_names_for_body(body),
1234 record!(self.tables.kind[def_id] <- EntryKind::AssocFn(self.lazy(AssocFnData {
1237 has_self: impl_item.fn_has_self_parameter,
1240 ty::AssocKind::Type => {
1241 record!(self.tables.kind[def_id] <- EntryKind::AssocType(container));
1244 self.encode_ident_span(def_id, impl_item.ident);
1245 self.encode_item_type(def_id);
1246 if impl_item.kind == ty::AssocKind::Fn {
1247 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1251 fn encode_fn_param_names_for_body(&mut self, body_id: hir::BodyId) -> Lazy<[Ident]> {
1252 self.lazy(self.tcx.hir().body_param_names(body_id))
1255 fn encode_fn_param_names(&mut self, param_names: &[Ident]) -> Lazy<[Ident]> {
1256 self.lazy(param_names.iter())
1259 fn encode_mir(&mut self) {
1260 if self.is_proc_macro {
1264 let mut keys_and_jobs = self
1268 .filter_map(|&def_id| {
1269 let (encode_const, encode_opt) = should_encode_mir(self.tcx, def_id);
1270 if encode_const || encode_opt {
1271 Some((def_id, encode_const, encode_opt))
1276 .collect::<Vec<_>>();
1277 // Sort everything to ensure a stable order for diagnotics.
1278 keys_and_jobs.sort_by_key(|&(def_id, _, _)| def_id);
1279 for (def_id, encode_const, encode_opt) in keys_and_jobs.into_iter() {
1280 debug_assert!(encode_const || encode_opt);
1282 debug!("EntryBuilder::encode_mir({:?})", def_id);
1284 record!(self.tables.mir[def_id.to_def_id()] <- self.tcx.optimized_mir(def_id));
1287 record!(self.tables.mir_for_ctfe[def_id.to_def_id()] <- self.tcx.mir_for_ctfe(def_id));
1289 let abstract_const = self.tcx.mir_abstract_const(def_id);
1290 if let Ok(Some(abstract_const)) = abstract_const {
1291 record!(self.tables.mir_abstract_consts[def_id.to_def_id()] <- abstract_const);
1294 record!(self.tables.promoted_mir[def_id.to_def_id()] <- self.tcx.promoted_mir(def_id));
1296 let unused = self.tcx.unused_generic_params(def_id);
1297 if !unused.is_empty() {
1298 record!(self.tables.unused_generic_params[def_id.to_def_id()] <- unused);
1303 fn encode_stability(&mut self, def_id: DefId) {
1304 debug!("EncodeContext::encode_stability({:?})", def_id);
1306 // The query lookup can take a measurable amount of time in crates with many items. Check if
1307 // the stability attributes are even enabled before using their queries.
1308 if self.feat.staged_api || self.tcx.sess.opts.debugging_opts.force_unstable_if_unmarked {
1309 if let Some(stab) = self.tcx.lookup_stability(def_id) {
1310 record!(self.tables.stability[def_id] <- stab)
1315 fn encode_const_stability(&mut self, def_id: DefId) {
1316 debug!("EncodeContext::encode_const_stability({:?})", def_id);
1318 // The query lookup can take a measurable amount of time in crates with many items. Check if
1319 // the stability attributes are even enabled before using their queries.
1320 if self.feat.staged_api || self.tcx.sess.opts.debugging_opts.force_unstable_if_unmarked {
1321 if let Some(stab) = self.tcx.lookup_const_stability(def_id) {
1322 record!(self.tables.const_stability[def_id] <- stab)
1327 fn encode_deprecation(&mut self, def_id: DefId) {
1328 debug!("EncodeContext::encode_deprecation({:?})", def_id);
1329 if let Some(depr) = self.tcx.lookup_deprecation(def_id) {
1330 record!(self.tables.deprecation[def_id] <- depr);
1334 fn encode_rendered_const_for_body(&mut self, body_id: hir::BodyId) -> Lazy<RenderedConst> {
1335 let hir = self.tcx.hir();
1336 let body = hir.body(body_id);
1337 let rendered = rustc_hir_pretty::to_string(&(&hir as &dyn intravisit::Map<'_>), |s| {
1338 s.print_expr(&body.value)
1340 let rendered_const = &RenderedConst(rendered);
1341 self.lazy(rendered_const)
1344 fn encode_info_for_item(&mut self, def_id: DefId, item: &'tcx hir::Item<'tcx>) {
1347 debug!("EncodeContext::encode_info_for_item({:?})", def_id);
1349 self.encode_ident_span(def_id, item.ident);
1351 let entry_kind = match item.kind {
1352 hir::ItemKind::Static(_, hir::Mutability::Mut, _) => EntryKind::MutStatic,
1353 hir::ItemKind::Static(_, hir::Mutability::Not, _) => EntryKind::ImmStatic,
1354 hir::ItemKind::Const(_, body_id) => {
1355 let qualifs = self.tcx.at(item.span).mir_const_qualif(def_id);
1356 EntryKind::Const(qualifs, self.encode_rendered_const_for_body(body_id))
1358 hir::ItemKind::Fn(ref sig, .., body) => {
1360 asyncness: sig.header.asyncness,
1361 constness: sig.header.constness,
1362 param_names: self.encode_fn_param_names_for_body(body),
1365 EntryKind::Fn(self.lazy(data))
1367 hir::ItemKind::Mod(ref m) => {
1368 return self.encode_info_for_mod(item.def_id, m);
1370 hir::ItemKind::ForeignMod { .. } => EntryKind::ForeignMod,
1371 hir::ItemKind::GlobalAsm(..) => EntryKind::GlobalAsm,
1372 hir::ItemKind::TyAlias(..) => EntryKind::Type,
1373 hir::ItemKind::OpaqueTy(..) => {
1374 self.encode_explicit_item_bounds(def_id);
1377 hir::ItemKind::Enum(..) => EntryKind::Enum(self.tcx.adt_def(def_id).repr),
1378 hir::ItemKind::Struct(ref struct_def, _) => {
1379 let adt_def = self.tcx.adt_def(def_id);
1380 let variant = adt_def.non_enum_variant();
1382 // Encode def_ids for each field and method
1383 // for methods, write all the stuff get_trait_method
1385 let ctor = struct_def
1387 .map(|ctor_hir_id| self.tcx.hir().local_def_id(ctor_hir_id).local_def_index);
1390 self.lazy(VariantData {
1391 ctor_kind: variant.ctor_kind,
1392 discr: variant.discr,
1394 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
1399 hir::ItemKind::Union(..) => {
1400 let adt_def = self.tcx.adt_def(def_id);
1401 let variant = adt_def.non_enum_variant();
1404 self.lazy(VariantData {
1405 ctor_kind: variant.ctor_kind,
1406 discr: variant.discr,
1408 is_non_exhaustive: variant.is_field_list_non_exhaustive(),
1413 hir::ItemKind::Impl(hir::Impl { defaultness, constness, .. }) => {
1414 let trait_ref = self.tcx.impl_trait_ref(def_id);
1415 let polarity = self.tcx.impl_polarity(def_id);
1416 let parent = if let Some(trait_ref) = trait_ref {
1417 let trait_def = self.tcx.trait_def(trait_ref.def_id);
1418 trait_def.ancestors(self.tcx, def_id).ok().and_then(|mut an| {
1419 an.nth(1).and_then(|node| match node {
1420 specialization_graph::Node::Impl(parent) => Some(parent),
1428 // if this is an impl of `CoerceUnsized`, create its
1429 // "unsized info", else just store None
1430 let coerce_unsized_info = trait_ref.and_then(|t| {
1431 if Some(t.def_id) == self.tcx.lang_items().coerce_unsized_trait() {
1432 Some(self.tcx.at(item.span).coerce_unsized_info(def_id))
1438 let data = ImplData {
1442 parent_impl: parent,
1443 coerce_unsized_info,
1446 EntryKind::Impl(self.lazy(data))
1448 hir::ItemKind::Trait(..) => {
1449 let trait_def = self.tcx.trait_def(def_id);
1450 let data = TraitData {
1451 unsafety: trait_def.unsafety,
1452 paren_sugar: trait_def.paren_sugar,
1453 has_auto_impl: self.tcx.trait_is_auto(def_id),
1454 is_marker: trait_def.is_marker,
1455 skip_array_during_method_dispatch: trait_def.skip_array_during_method_dispatch,
1456 specialization_kind: trait_def.specialization_kind,
1459 EntryKind::Trait(self.lazy(data))
1461 hir::ItemKind::TraitAlias(..) => EntryKind::TraitAlias,
1462 hir::ItemKind::ExternCrate(_) | hir::ItemKind::Use(..) => {
1463 bug!("cannot encode info for item {:?}", item)
1466 record!(self.tables.kind[def_id] <- entry_kind);
1467 // FIXME(eddyb) there should be a nicer way to do this.
1469 hir::ItemKind::ForeignMod { items, .. } => record!(self.tables.children[def_id] <-
1472 .map(|foreign_item| foreign_item.id.def_id.local_def_index)
1474 hir::ItemKind::Enum(..) => record!(self.tables.children[def_id] <-
1475 self.tcx.adt_def(def_id).variants.iter().map(|v| {
1476 assert!(v.def_id.is_local());
1480 hir::ItemKind::Struct(..) | hir::ItemKind::Union(..) => {
1481 record!(self.tables.children[def_id] <-
1482 self.tcx.adt_def(def_id).non_enum_variant().fields.iter().map(|f| {
1483 assert!(f.did.is_local());
1488 hir::ItemKind::Impl { .. } | hir::ItemKind::Trait(..) => {
1489 let associated_item_def_ids = self.tcx.associated_item_def_ids(def_id);
1490 record!(self.tables.children[def_id] <-
1491 associated_item_def_ids.iter().map(|&def_id| {
1492 assert!(def_id.is_local());
1500 hir::ItemKind::Static(..)
1501 | hir::ItemKind::Const(..)
1502 | hir::ItemKind::Fn(..)
1503 | hir::ItemKind::TyAlias(..)
1504 | hir::ItemKind::OpaqueTy(..)
1505 | hir::ItemKind::Enum(..)
1506 | hir::ItemKind::Struct(..)
1507 | hir::ItemKind::Union(..)
1508 | hir::ItemKind::Impl { .. } => self.encode_item_type(def_id),
1511 if let hir::ItemKind::Fn(..) = item.kind {
1512 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1514 if let hir::ItemKind::Impl { .. } = item.kind {
1515 if let Some(trait_ref) = self.tcx.impl_trait_ref(def_id) {
1516 record!(self.tables.impl_trait_ref[def_id] <- trait_ref);
1521 /// Serialize the text of exported macros
1522 fn encode_info_for_macro_def(&mut self, macro_def: &hir::MacroDef<'_>) {
1523 let def_id = macro_def.def_id.to_def_id();
1524 record!(self.tables.kind[def_id] <- EntryKind::MacroDef(self.lazy(macro_def.ast.clone())));
1525 self.encode_ident_span(def_id, macro_def.ident);
1528 fn encode_info_for_generic_param(&mut self, def_id: DefId, kind: EntryKind, encode_type: bool) {
1529 record!(self.tables.kind[def_id] <- kind);
1531 self.encode_item_type(def_id);
1535 fn encode_info_for_closure(&mut self, def_id: LocalDefId) {
1536 debug!("EncodeContext::encode_info_for_closure({:?})", def_id);
1538 // NOTE(eddyb) `tcx.type_of(def_id)` isn't used because it's fully generic,
1539 // including on the signature, which is inferred in `typeck.
1540 let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
1541 let ty = self.tcx.typeck(def_id).node_type(hir_id);
1544 ty::Generator(..) => {
1545 let data = self.tcx.generator_kind(def_id).unwrap();
1546 record!(self.tables.kind[def_id.to_def_id()] <- EntryKind::Generator(data));
1549 ty::Closure(..) => {
1550 record!(self.tables.kind[def_id.to_def_id()] <- EntryKind::Closure);
1553 _ => bug!("closure that is neither generator nor closure"),
1555 self.encode_item_type(def_id.to_def_id());
1556 if let ty::Closure(def_id, substs) = *ty.kind() {
1557 record!(self.tables.fn_sig[def_id] <- substs.as_closure().sig());
1561 fn encode_info_for_anon_const(&mut self, def_id: LocalDefId) {
1562 debug!("EncodeContext::encode_info_for_anon_const({:?})", def_id);
1563 let id = self.tcx.hir().local_def_id_to_hir_id(def_id);
1564 let body_id = self.tcx.hir().body_owned_by(id);
1565 let const_data = self.encode_rendered_const_for_body(body_id);
1566 let qualifs = self.tcx.mir_const_qualif(def_id);
1568 record!(self.tables.kind[def_id.to_def_id()] <- EntryKind::AnonConst(qualifs, const_data));
1569 self.encode_item_type(def_id.to_def_id());
1572 fn encode_native_libraries(&mut self) -> Lazy<[NativeLib]> {
1573 empty_proc_macro!(self);
1574 let used_libraries = self.tcx.native_libraries(LOCAL_CRATE);
1575 self.lazy(used_libraries.iter().cloned())
1578 fn encode_foreign_modules(&mut self) -> Lazy<[ForeignModule]> {
1579 empty_proc_macro!(self);
1580 let foreign_modules = self.tcx.foreign_modules(LOCAL_CRATE);
1581 self.lazy(foreign_modules.iter().map(|(_, m)| m).cloned())
1584 fn encode_hygiene(&mut self) -> (SyntaxContextTable, ExpnDataTable, ExpnHashTable) {
1585 let mut syntax_contexts: TableBuilder<_, _> = Default::default();
1586 let mut expn_data_table: TableBuilder<_, _> = Default::default();
1587 let mut expn_hash_table: TableBuilder<_, _> = Default::default();
1589 let _: Result<(), !> = self.hygiene_ctxt.encode(
1590 &mut (&mut *self, &mut syntax_contexts, &mut expn_data_table, &mut expn_hash_table),
1591 |(this, syntax_contexts, _, _), index, ctxt_data| {
1592 syntax_contexts.set(index, this.lazy(ctxt_data));
1595 |(this, _, expn_data_table, expn_hash_table), index, expn_data, hash| {
1596 expn_data_table.set(index, this.lazy(expn_data));
1597 expn_hash_table.set(index, this.lazy(hash));
1603 syntax_contexts.encode(&mut self.opaque),
1604 expn_data_table.encode(&mut self.opaque),
1605 expn_hash_table.encode(&mut self.opaque),
1609 fn encode_proc_macros(&mut self) -> Option<ProcMacroData> {
1610 let is_proc_macro = self.tcx.sess.crate_types().contains(&CrateType::ProcMacro);
1613 let hir = tcx.hir();
1615 let proc_macro_decls_static = tcx.proc_macro_decls_static(()).unwrap().local_def_index;
1616 let stability = tcx.lookup_stability(DefId::local(CRATE_DEF_INDEX)).copied();
1617 let macros = self.lazy(hir.krate().proc_macros.iter().map(|p| p.owner.local_def_index));
1618 let spans = self.tcx.sess.parse_sess.proc_macro_quoted_spans();
1619 for (i, span) in spans.into_iter().enumerate() {
1620 let span = self.lazy(span);
1621 self.tables.proc_macro_quoted_spans.set(i, span);
1624 record!(self.tables.def_kind[LOCAL_CRATE.as_def_id()] <- DefKind::Mod);
1625 record!(self.tables.span[LOCAL_CRATE.as_def_id()] <- tcx.def_span(LOCAL_CRATE.as_def_id()));
1626 record!(self.tables.attributes[LOCAL_CRATE.as_def_id()] <- tcx.get_attrs(LOCAL_CRATE.as_def_id()));
1627 record!(self.tables.visibility[LOCAL_CRATE.as_def_id()] <- tcx.visibility(LOCAL_CRATE.as_def_id()));
1628 if let Some(stability) = stability {
1629 record!(self.tables.stability[LOCAL_CRATE.as_def_id()] <- stability);
1631 self.encode_deprecation(LOCAL_CRATE.as_def_id());
1633 // Normally, this information is encoded when we walk the items
1634 // defined in this crate. However, we skip doing that for proc-macro crates,
1635 // so we manually encode just the information that we need
1636 for proc_macro in &hir.krate().proc_macros {
1637 let id = proc_macro.owner.local_def_index;
1638 let mut name = hir.name(*proc_macro);
1639 let span = hir.span(*proc_macro);
1640 // Proc-macros may have attributes like `#[allow_internal_unstable]`,
1641 // so downstream crates need access to them.
1642 let attrs = hir.attrs(*proc_macro);
1643 let macro_kind = if tcx.sess.contains_name(attrs, sym::proc_macro) {
1645 } else if tcx.sess.contains_name(attrs, sym::proc_macro_attribute) {
1647 } else if let Some(attr) = tcx.sess.find_by_name(attrs, sym::proc_macro_derive) {
1648 // This unwrap chain should have been checked by the proc-macro harness.
1649 name = attr.meta_item_list().unwrap()[0]
1657 bug!("Unknown proc-macro type for item {:?}", id);
1660 let mut def_key = self.tcx.hir().def_key(proc_macro.owner);
1661 def_key.disambiguated_data.data = DefPathData::MacroNs(name);
1663 let def_id = DefId::local(id);
1664 record!(self.tables.def_kind[def_id] <- DefKind::Macro(macro_kind));
1665 record!(self.tables.kind[def_id] <- EntryKind::ProcMacro(macro_kind));
1666 record!(self.tables.attributes[def_id] <- attrs);
1667 record!(self.tables.def_keys[def_id] <- def_key);
1668 record!(self.tables.ident_span[def_id] <- span);
1669 record!(self.tables.span[def_id] <- span);
1670 record!(self.tables.visibility[def_id] <- ty::Visibility::Public);
1671 if let Some(stability) = stability {
1672 record!(self.tables.stability[def_id] <- stability);
1676 Some(ProcMacroData { proc_macro_decls_static, stability, macros })
1682 fn encode_crate_deps(&mut self) -> Lazy<[CrateDep]> {
1683 empty_proc_macro!(self);
1684 let crates = self.tcx.crates(());
1686 let mut deps = crates
1689 let dep = CrateDep {
1690 name: self.tcx.crate_name(cnum),
1691 hash: self.tcx.crate_hash(cnum),
1692 host_hash: self.tcx.crate_host_hash(cnum),
1693 kind: self.tcx.dep_kind(cnum),
1694 extra_filename: self.tcx.extra_filename(cnum),
1698 .collect::<Vec<_>>();
1700 deps.sort_by_key(|&(cnum, _)| cnum);
1703 // Sanity-check the crate numbers
1704 let mut expected_cnum = 1;
1705 for &(n, _) in &deps {
1706 assert_eq!(n, CrateNum::new(expected_cnum));
1711 // We're just going to write a list of crate 'name-hash-version's, with
1712 // the assumption that they are numbered 1 to n.
1713 // FIXME (#2166): This is not nearly enough to support correct versioning
1714 // but is enough to get transitive crate dependencies working.
1715 self.lazy(deps.iter().map(|&(_, ref dep)| dep))
1718 fn encode_lib_features(&mut self) -> Lazy<[(Symbol, Option<Symbol>)]> {
1719 empty_proc_macro!(self);
1721 let lib_features = tcx.lib_features();
1722 self.lazy(lib_features.to_vec())
1725 fn encode_diagnostic_items(&mut self) -> Lazy<[(Symbol, DefIndex)]> {
1726 empty_proc_macro!(self);
1728 let diagnostic_items = tcx.diagnostic_items(LOCAL_CRATE);
1729 self.lazy(diagnostic_items.iter().map(|(&name, def_id)| (name, def_id.index)))
1732 fn encode_lang_items(&mut self) -> Lazy<[(DefIndex, usize)]> {
1733 empty_proc_macro!(self);
1735 let lang_items = tcx.lang_items();
1736 let lang_items = lang_items.items().iter();
1737 self.lazy(lang_items.enumerate().filter_map(|(i, &opt_def_id)| {
1738 if let Some(def_id) = opt_def_id {
1739 if def_id.is_local() {
1740 return Some((def_id.index, i));
1747 fn encode_lang_items_missing(&mut self) -> Lazy<[lang_items::LangItem]> {
1748 empty_proc_macro!(self);
1750 self.lazy(&tcx.lang_items().missing)
1753 /// Encodes an index, mapping each trait to its (local) implementations.
1754 fn encode_impls(&mut self) -> Lazy<[TraitImpls]> {
1755 empty_proc_macro!(self);
1756 debug!("EncodeContext::encode_impls()");
1758 let mut visitor = ImplVisitor { tcx, impls: FxHashMap::default() };
1759 tcx.hir().krate().visit_all_item_likes(&mut visitor);
1761 let mut all_impls: Vec<_> = visitor.impls.into_iter().collect();
1763 // Bring everything into deterministic order for hashing
1764 all_impls.sort_by_cached_key(|&(trait_def_id, _)| tcx.def_path_hash(trait_def_id));
1766 let all_impls: Vec<_> = all_impls
1768 .map(|(trait_def_id, mut impls)| {
1769 // Bring everything into deterministic order for hashing
1770 impls.sort_by_cached_key(|&(index, _)| {
1771 tcx.hir().def_path_hash(LocalDefId { local_def_index: index })
1775 trait_id: (trait_def_id.krate.as_u32(), trait_def_id.index),
1776 impls: self.lazy(&impls),
1781 self.lazy(&all_impls)
1784 // Encodes all symbols exported from this crate into the metadata.
1786 // This pass is seeded off the reachability list calculated in the
1787 // middle::reachable module but filters out items that either don't have a
1788 // symbol associated with them (they weren't translated) or if they're an FFI
1789 // definition (as that's not defined in this crate).
1790 fn encode_exported_symbols(
1792 exported_symbols: &[(ExportedSymbol<'tcx>, SymbolExportLevel)],
1793 ) -> Lazy<[(ExportedSymbol<'tcx>, SymbolExportLevel)]> {
1794 empty_proc_macro!(self);
1795 // The metadata symbol name is special. It should not show up in
1796 // downstream crates.
1797 let metadata_symbol_name = SymbolName::new(self.tcx, &metadata_symbol_name(self.tcx));
1802 .filter(|&&(ref exported_symbol, _)| match *exported_symbol {
1803 ExportedSymbol::NoDefId(symbol_name) => symbol_name != metadata_symbol_name,
1810 fn encode_dylib_dependency_formats(&mut self) -> Lazy<[Option<LinkagePreference>]> {
1811 empty_proc_macro!(self);
1812 let formats = self.tcx.dependency_formats(());
1813 for (ty, arr) in formats.iter() {
1814 if *ty != CrateType::Dylib {
1817 return self.lazy(arr.iter().map(|slot| match *slot {
1818 Linkage::NotLinked | Linkage::IncludedFromDylib => None,
1820 Linkage::Dynamic => Some(LinkagePreference::RequireDynamic),
1821 Linkage::Static => Some(LinkagePreference::RequireStatic),
1827 fn encode_info_for_foreign_item(&mut self, def_id: DefId, nitem: &hir::ForeignItem<'_>) {
1830 debug!("EncodeContext::encode_info_for_foreign_item({:?})", def_id);
1833 hir::ForeignItemKind::Fn(_, ref names, _) => {
1835 asyncness: hir::IsAsync::NotAsync,
1836 constness: if self.tcx.is_const_fn_raw(def_id) {
1837 hir::Constness::Const
1839 hir::Constness::NotConst
1841 param_names: self.encode_fn_param_names(names),
1843 record!(self.tables.kind[def_id] <- EntryKind::ForeignFn(self.lazy(data)));
1845 hir::ForeignItemKind::Static(_, hir::Mutability::Mut) => {
1846 record!(self.tables.kind[def_id] <- EntryKind::ForeignMutStatic);
1848 hir::ForeignItemKind::Static(_, hir::Mutability::Not) => {
1849 record!(self.tables.kind[def_id] <- EntryKind::ForeignImmStatic);
1851 hir::ForeignItemKind::Type => {
1852 record!(self.tables.kind[def_id] <- EntryKind::ForeignType);
1855 self.encode_ident_span(def_id, nitem.ident);
1856 self.encode_item_type(def_id);
1857 if let hir::ForeignItemKind::Fn(..) = nitem.kind {
1858 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
1863 // FIXME(eddyb) make metadata encoding walk over all definitions, instead of HIR.
1864 impl Visitor<'tcx> for EncodeContext<'a, 'tcx> {
1865 type Map = Map<'tcx>;
1867 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1868 NestedVisitorMap::OnlyBodies(self.tcx.hir())
1870 fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
1871 intravisit::walk_expr(self, ex);
1872 self.encode_info_for_expr(ex);
1874 fn visit_anon_const(&mut self, c: &'tcx AnonConst) {
1875 intravisit::walk_anon_const(self, c);
1876 let def_id = self.tcx.hir().local_def_id(c.hir_id);
1877 self.encode_info_for_anon_const(def_id);
1879 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1880 intravisit::walk_item(self, item);
1882 hir::ItemKind::ExternCrate(_) | hir::ItemKind::Use(..) => {} // ignore these
1883 _ => self.encode_info_for_item(item.def_id.to_def_id(), item),
1885 self.encode_addl_info_for_item(item);
1887 fn visit_foreign_item(&mut self, ni: &'tcx hir::ForeignItem<'tcx>) {
1888 intravisit::walk_foreign_item(self, ni);
1889 self.encode_info_for_foreign_item(ni.def_id.to_def_id(), ni);
1891 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1892 intravisit::walk_generics(self, generics);
1893 self.encode_info_for_generics(generics);
1895 fn visit_macro_def(&mut self, macro_def: &'tcx hir::MacroDef<'tcx>) {
1896 self.encode_info_for_macro_def(macro_def);
1900 impl EncodeContext<'a, 'tcx> {
1901 fn encode_fields(&mut self, adt_def: &ty::AdtDef) {
1902 for (variant_index, variant) in adt_def.variants.iter_enumerated() {
1903 for (field_index, _field) in variant.fields.iter().enumerate() {
1904 self.encode_field(adt_def, variant_index, field_index);
1909 fn encode_info_for_generics(&mut self, generics: &hir::Generics<'tcx>) {
1910 for param in generics.params {
1911 let def_id = self.tcx.hir().local_def_id(param.hir_id);
1913 GenericParamKind::Lifetime { .. } => continue,
1914 GenericParamKind::Type { default, .. } => {
1915 self.encode_info_for_generic_param(
1917 EntryKind::TypeParam,
1921 GenericParamKind::Const { ref default, .. } => {
1922 let def_id = def_id.to_def_id();
1923 self.encode_info_for_generic_param(def_id, EntryKind::ConstParam, true);
1924 if default.is_some() {
1925 record!(self.tables.const_defaults[def_id] <- self.tcx.const_param_default(def_id))
1932 fn encode_info_for_expr(&mut self, expr: &hir::Expr<'_>) {
1933 if let hir::ExprKind::Closure(..) = expr.kind {
1934 let def_id = self.tcx.hir().local_def_id(expr.hir_id);
1935 self.encode_info_for_closure(def_id);
1939 fn encode_ident_span(&mut self, def_id: DefId, ident: Ident) {
1940 record!(self.tables.ident_span[def_id] <- ident.span);
1943 /// In some cases, along with the item itself, we also
1944 /// encode some sub-items. Usually we want some info from the item
1945 /// so it's easier to do that here then to wait until we would encounter
1946 /// normally in the visitor walk.
1947 fn encode_addl_info_for_item(&mut self, item: &hir::Item<'_>) {
1949 hir::ItemKind::Static(..)
1950 | hir::ItemKind::Const(..)
1951 | hir::ItemKind::Fn(..)
1952 | hir::ItemKind::Mod(..)
1953 | hir::ItemKind::ForeignMod { .. }
1954 | hir::ItemKind::GlobalAsm(..)
1955 | hir::ItemKind::ExternCrate(..)
1956 | hir::ItemKind::Use(..)
1957 | hir::ItemKind::TyAlias(..)
1958 | hir::ItemKind::OpaqueTy(..)
1959 | hir::ItemKind::TraitAlias(..) => {
1960 // no sub-item recording needed in these cases
1962 hir::ItemKind::Enum(..) => {
1963 let def = self.tcx.adt_def(item.def_id.to_def_id());
1964 self.encode_fields(def);
1966 for (i, variant) in def.variants.iter_enumerated() {
1967 self.encode_enum_variant_info(def, i);
1969 if let Some(_ctor_def_id) = variant.ctor_def_id {
1970 self.encode_enum_variant_ctor(def, i);
1974 hir::ItemKind::Struct(ref struct_def, _) => {
1975 let def = self.tcx.adt_def(item.def_id.to_def_id());
1976 self.encode_fields(def);
1978 // If the struct has a constructor, encode it.
1979 if let Some(ctor_hir_id) = struct_def.ctor_hir_id() {
1980 let ctor_def_id = self.tcx.hir().local_def_id(ctor_hir_id);
1981 self.encode_struct_ctor(def, ctor_def_id.to_def_id());
1984 hir::ItemKind::Union(..) => {
1985 let def = self.tcx.adt_def(item.def_id.to_def_id());
1986 self.encode_fields(def);
1988 hir::ItemKind::Impl { .. } => {
1989 for &trait_item_def_id in
1990 self.tcx.associated_item_def_ids(item.def_id.to_def_id()).iter()
1992 self.encode_info_for_impl_item(trait_item_def_id);
1995 hir::ItemKind::Trait(..) => {
1996 for &item_def_id in self.tcx.associated_item_def_ids(item.def_id.to_def_id()).iter()
1998 self.encode_info_for_trait_item(item_def_id);
2005 struct ImplVisitor<'tcx> {
2007 impls: FxHashMap<DefId, Vec<(DefIndex, Option<ty::fast_reject::SimplifiedType>)>>,
2010 impl<'tcx, 'v> ItemLikeVisitor<'v> for ImplVisitor<'tcx> {
2011 fn visit_item(&mut self, item: &hir::Item<'_>) {
2012 if let hir::ItemKind::Impl { .. } = item.kind {
2013 if let Some(trait_ref) = self.tcx.impl_trait_ref(item.def_id.to_def_id()) {
2014 let simplified_self_ty =
2015 ty::fast_reject::simplify_type(self.tcx, trait_ref.self_ty(), false);
2018 .entry(trait_ref.def_id)
2020 .push((item.def_id.local_def_index, simplified_self_ty));
2025 fn visit_trait_item(&mut self, _trait_item: &'v hir::TraitItem<'v>) {}
2027 fn visit_impl_item(&mut self, _impl_item: &'v hir::ImplItem<'v>) {
2028 // handled in `visit_item` above
2031 fn visit_foreign_item(&mut self, _foreign_item: &'v hir::ForeignItem<'v>) {}
2034 /// Used to prefetch queries which will be needed later by metadata encoding.
2035 /// Only a subset of the queries are actually prefetched to keep this code smaller.
2036 fn prefetch_mir(tcx: TyCtxt<'_>) {
2037 if !tcx.sess.opts.output_types.should_codegen() {
2038 // We won't emit MIR, so don't prefetch it.
2042 par_iter(tcx.mir_keys(())).for_each(|&def_id| {
2043 let (encode_const, encode_opt) = should_encode_mir(tcx, def_id);
2046 tcx.ensure().mir_for_ctfe(def_id);
2049 tcx.ensure().optimized_mir(def_id);
2051 if encode_opt || encode_const {
2052 tcx.ensure().promoted_mir(def_id);
2057 // NOTE(eddyb) The following comment was preserved for posterity, even
2058 // though it's no longer relevant as EBML (which uses nested & tagged
2059 // "documents") was replaced with a scheme that can't go out of bounds.
2061 // And here we run into yet another obscure archive bug: in which metadata
2062 // loaded from archives may have trailing garbage bytes. Awhile back one of
2063 // our tests was failing sporadically on the macOS 64-bit builders (both nopt
2064 // and opt) by having ebml generate an out-of-bounds panic when looking at
2067 // Upon investigation it turned out that the metadata file inside of an rlib
2068 // (and ar archive) was being corrupted. Some compilations would generate a
2069 // metadata file which would end in a few extra bytes, while other
2070 // compilations would not have these extra bytes appended to the end. These
2071 // extra bytes were interpreted by ebml as an extra tag, so they ended up
2072 // being interpreted causing the out-of-bounds.
2074 // The root cause of why these extra bytes were appearing was never
2075 // discovered, and in the meantime the solution we're employing is to insert
2076 // the length of the metadata to the start of the metadata. Later on this
2077 // will allow us to slice the metadata to the precise length that we just
2078 // generated regardless of trailing bytes that end up in it.
2080 pub(super) fn encode_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata {
2081 // Since encoding metadata is not in a query, and nothing is cached,
2082 // there's no need to do dep-graph tracking for any of it.
2083 tcx.dep_graph.assert_ignored();
2086 || encode_metadata_impl(tcx),
2088 if tcx.sess.threads() == 1 {
2091 // Prefetch some queries used by metadata encoding.
2092 // This is not necessary for correctness, but is only done for performance reasons.
2093 // It can be removed if it turns out to cause trouble or be detrimental to performance.
2094 join(|| prefetch_mir(tcx), || tcx.exported_symbols(LOCAL_CRATE));
2100 fn encode_metadata_impl(tcx: TyCtxt<'_>) -> EncodedMetadata {
2101 let mut encoder = opaque::Encoder::new(vec![]);
2102 encoder.emit_raw_bytes(METADATA_HEADER).unwrap();
2104 // Will be filled with the root position after encoding everything.
2105 encoder.emit_raw_bytes(&[0, 0, 0, 0]).unwrap();
2107 let source_map_files = tcx.sess.source_map().files();
2108 let source_file_cache = (source_map_files[0].clone(), 0);
2109 let required_source_files = Some(GrowableBitSet::with_capacity(source_map_files.len()));
2110 drop(source_map_files);
2112 let hygiene_ctxt = HygieneEncodeContext::default();
2114 let mut ecx = EncodeContext {
2117 feat: tcx.features(),
2118 tables: Default::default(),
2119 lazy_state: LazyState::NoNode,
2120 type_shorthands: Default::default(),
2121 predicate_shorthands: Default::default(),
2123 interpret_allocs: Default::default(),
2124 required_source_files,
2125 is_proc_macro: tcx.sess.crate_types().contains(&CrateType::ProcMacro),
2126 hygiene_ctxt: &hygiene_ctxt,
2129 // Encode the rustc version string in a predictable location.
2130 rustc_version().encode(&mut ecx).unwrap();
2132 // Encode all the entries and extra information in the crate,
2133 // culminating in the `CrateRoot` which points to all of it.
2134 let root = ecx.encode_crate_root();
2136 let mut result = ecx.opaque.into_inner();
2138 // Encode the root position.
2139 let header = METADATA_HEADER.len();
2140 let pos = root.position.get();
2141 result[header + 0] = (pos >> 24) as u8;
2142 result[header + 1] = (pos >> 16) as u8;
2143 result[header + 2] = (pos >> 8) as u8;
2144 result[header + 3] = (pos >> 0) as u8;
2146 EncodedMetadata { raw_data: result }