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-rw-r--r--compiler/rustc_metadata/src/rmeta/decoder.rs1820
1 files changed, 1820 insertions, 0 deletions
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
new file mode 100644
index 000000000..40dc4fb05
--- /dev/null
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -0,0 +1,1820 @@
+// Decoding metadata from a single crate's metadata
+
+use crate::creader::{CStore, CrateMetadataRef};
+use crate::rmeta::*;
+
+use rustc_ast as ast;
+use rustc_ast::ptr::P;
+use rustc_data_structures::captures::Captures;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::svh::Svh;
+use rustc_data_structures::sync::{Lock, LockGuard, Lrc, OnceCell};
+use rustc_data_structures::unhash::UnhashMap;
+use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
+use rustc_expand::proc_macro::{AttrProcMacro, BangProcMacro, DeriveProcMacro};
+use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
+use rustc_hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
+use rustc_hir::definitions::{DefKey, DefPath, DefPathData, DefPathHash};
+use rustc_hir::diagnostic_items::DiagnosticItems;
+use rustc_hir::lang_items;
+use rustc_index::vec::{Idx, IndexVec};
+use rustc_middle::metadata::ModChild;
+use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo};
+use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
+use rustc_middle::ty::codec::TyDecoder;
+use rustc_middle::ty::fast_reject::SimplifiedType;
+use rustc_middle::ty::GeneratorDiagnosticData;
+use rustc_middle::ty::{self, ParameterizedOverTcx, Ty, TyCtxt, Visibility};
+use rustc_serialize::opaque::MemDecoder;
+use rustc_serialize::{Decodable, Decoder};
+use rustc_session::cstore::{
+ CrateSource, ExternCrate, ForeignModule, LinkagePreference, NativeLib,
+};
+use rustc_session::Session;
+use rustc_span::hygiene::{ExpnIndex, MacroKind};
+use rustc_span::source_map::{respan, Spanned};
+use rustc_span::symbol::{sym, Ident, Symbol};
+use rustc_span::{self, BytePos, ExpnId, Pos, Span, SyntaxContext, DUMMY_SP};
+
+use proc_macro::bridge::client::ProcMacro;
+use std::io;
+use std::iter::TrustedLen;
+use std::mem;
+use std::num::NonZeroUsize;
+use std::path::Path;
+use tracing::debug;
+
+pub(super) use cstore_impl::provide;
+pub use cstore_impl::provide_extern;
+use rustc_span::hygiene::HygieneDecodeContext;
+
+mod cstore_impl;
+
+/// A reference to the raw binary version of crate metadata.
+/// A `MetadataBlob` internally is just a reference counted pointer to
+/// the actual data, so cloning it is cheap.
+#[derive(Clone)]
+pub(crate) struct MetadataBlob(Lrc<MetadataRef>);
+
+// This is needed so we can create an OwningRef into the blob.
+// The data behind a `MetadataBlob` has a stable address because it is
+// contained within an Rc/Arc.
+unsafe impl rustc_data_structures::owning_ref::StableAddress for MetadataBlob {}
+
+// This is needed so we can create an OwningRef into the blob.
+impl std::ops::Deref for MetadataBlob {
+ type Target = [u8];
+
+ #[inline]
+ fn deref(&self) -> &[u8] {
+ &self.0[..]
+ }
+}
+
+// A map from external crate numbers (as decoded from some crate file) to
+// local crate numbers (as generated during this session). Each external
+// crate may refer to types in other external crates, and each has their
+// own crate numbers.
+pub(crate) type CrateNumMap = IndexVec<CrateNum, CrateNum>;
+
+pub(crate) struct CrateMetadata {
+ /// The primary crate data - binary metadata blob.
+ blob: MetadataBlob,
+
+ // --- Some data pre-decoded from the metadata blob, usually for performance ---
+ /// NOTE(eddyb) we pass `'static` to a `'tcx` parameter because this
+ /// lifetime is only used behind `LazyValue`, `LazyArray`, or `LazyTable`, and therefore acts like a
+ /// universal (`for<'tcx>`), that is paired up with whichever `TyCtxt`
+ /// is being used to decode those values.
+ root: CrateRoot,
+ /// Trait impl data.
+ /// FIXME: Used only from queries and can use query cache,
+ /// so pre-decoding can probably be avoided.
+ trait_impls: FxHashMap<(u32, DefIndex), LazyArray<(DefIndex, Option<SimplifiedType>)>>,
+ /// Inherent impls which do not follow the normal coherence rules.
+ ///
+ /// These can be introduced using either `#![rustc_coherence_is_core]`
+ /// or `#[rustc_allow_incoherent_impl]`.
+ incoherent_impls: FxHashMap<SimplifiedType, LazyArray<DefIndex>>,
+ /// Proc macro descriptions for this crate, if it's a proc macro crate.
+ raw_proc_macros: Option<&'static [ProcMacro]>,
+ /// Source maps for code from the crate.
+ source_map_import_info: OnceCell<Vec<ImportedSourceFile>>,
+ /// For every definition in this crate, maps its `DefPathHash` to its `DefIndex`.
+ def_path_hash_map: DefPathHashMapRef<'static>,
+ /// Likewise for ExpnHash.
+ expn_hash_map: OnceCell<UnhashMap<ExpnHash, ExpnIndex>>,
+ /// Used for decoding interpret::AllocIds in a cached & thread-safe manner.
+ alloc_decoding_state: AllocDecodingState,
+ /// Caches decoded `DefKey`s.
+ def_key_cache: Lock<FxHashMap<DefIndex, DefKey>>,
+ /// Caches decoded `DefPathHash`es.
+ def_path_hash_cache: Lock<FxHashMap<DefIndex, DefPathHash>>,
+
+ // --- Other significant crate properties ---
+ /// ID of this crate, from the current compilation session's point of view.
+ cnum: CrateNum,
+ /// Maps crate IDs as they are were seen from this crate's compilation sessions into
+ /// IDs as they are seen from the current compilation session.
+ cnum_map: CrateNumMap,
+ /// Same ID set as `cnum_map` plus maybe some injected crates like panic runtime.
+ dependencies: Lock<Vec<CrateNum>>,
+ /// How to link (or not link) this crate to the currently compiled crate.
+ dep_kind: Lock<CrateDepKind>,
+ /// Filesystem location of this crate.
+ source: Lrc<CrateSource>,
+ /// Whether or not this crate should be consider a private dependency
+ /// for purposes of the 'exported_private_dependencies' lint
+ private_dep: bool,
+ /// The hash for the host proc macro. Used to support `-Z dual-proc-macro`.
+ host_hash: Option<Svh>,
+
+ /// Additional data used for decoding `HygieneData` (e.g. `SyntaxContext`
+ /// and `ExpnId`).
+ /// Note that we store a `HygieneDecodeContext` for each `CrateMetadat`. This is
+ /// because `SyntaxContext` ids are not globally unique, so we need
+ /// to track which ids we've decoded on a per-crate basis.
+ hygiene_context: HygieneDecodeContext,
+
+ // --- Data used only for improving diagnostics ---
+ /// Information about the `extern crate` item or path that caused this crate to be loaded.
+ /// If this is `None`, then the crate was injected (e.g., by the allocator).
+ extern_crate: Lock<Option<ExternCrate>>,
+}
+
+/// Holds information about a rustc_span::SourceFile imported from another crate.
+/// See `imported_source_files()` for more information.
+struct ImportedSourceFile {
+ /// This SourceFile's byte-offset within the source_map of its original crate
+ original_start_pos: rustc_span::BytePos,
+ /// The end of this SourceFile within the source_map of its original crate
+ original_end_pos: rustc_span::BytePos,
+ /// The imported SourceFile's representation within the local source_map
+ translated_source_file: Lrc<rustc_span::SourceFile>,
+}
+
+pub(super) struct DecodeContext<'a, 'tcx> {
+ opaque: MemDecoder<'a>,
+ cdata: Option<CrateMetadataRef<'a>>,
+ blob: &'a MetadataBlob,
+ sess: Option<&'tcx Session>,
+ tcx: Option<TyCtxt<'tcx>>,
+
+ // Cache the last used source_file for translating spans as an optimization.
+ last_source_file_index: usize,
+
+ lazy_state: LazyState,
+
+ // Used for decoding interpret::AllocIds in a cached & thread-safe manner.
+ alloc_decoding_session: Option<AllocDecodingSession<'a>>,
+}
+
+/// Abstract over the various ways one can create metadata decoders.
+pub(super) trait Metadata<'a, 'tcx>: Copy {
+ fn blob(self) -> &'a MetadataBlob;
+
+ fn cdata(self) -> Option<CrateMetadataRef<'a>> {
+ None
+ }
+ fn sess(self) -> Option<&'tcx Session> {
+ None
+ }
+ fn tcx(self) -> Option<TyCtxt<'tcx>> {
+ None
+ }
+
+ fn decoder(self, pos: usize) -> DecodeContext<'a, 'tcx> {
+ let tcx = self.tcx();
+ DecodeContext {
+ opaque: MemDecoder::new(self.blob(), pos),
+ cdata: self.cdata(),
+ blob: self.blob(),
+ sess: self.sess().or(tcx.map(|tcx| tcx.sess)),
+ tcx,
+ last_source_file_index: 0,
+ lazy_state: LazyState::NoNode,
+ alloc_decoding_session: self
+ .cdata()
+ .map(|cdata| cdata.cdata.alloc_decoding_state.new_decoding_session()),
+ }
+ }
+}
+
+impl<'a, 'tcx> Metadata<'a, 'tcx> for &'a MetadataBlob {
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ self
+ }
+}
+
+impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a MetadataBlob, &'tcx Session) {
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ self.0
+ }
+
+ #[inline]
+ fn sess(self) -> Option<&'tcx Session> {
+ let (_, sess) = self;
+ Some(sess)
+ }
+}
+
+impl<'a, 'tcx> Metadata<'a, 'tcx> for CrateMetadataRef<'a> {
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ &self.cdata.blob
+ }
+ #[inline]
+ fn cdata(self) -> Option<CrateMetadataRef<'a>> {
+ Some(self)
+ }
+}
+
+impl<'a, 'tcx> Metadata<'a, 'tcx> for (CrateMetadataRef<'a>, &'tcx Session) {
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ &self.0.cdata.blob
+ }
+ #[inline]
+ fn cdata(self) -> Option<CrateMetadataRef<'a>> {
+ Some(self.0)
+ }
+ #[inline]
+ fn sess(self) -> Option<&'tcx Session> {
+ Some(self.1)
+ }
+}
+
+impl<'a, 'tcx> Metadata<'a, 'tcx> for (CrateMetadataRef<'a>, TyCtxt<'tcx>) {
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ &self.0.cdata.blob
+ }
+ #[inline]
+ fn cdata(self) -> Option<CrateMetadataRef<'a>> {
+ Some(self.0)
+ }
+ #[inline]
+ fn tcx(self) -> Option<TyCtxt<'tcx>> {
+ Some(self.1)
+ }
+}
+
+impl<T: ParameterizedOverTcx> LazyValue<T> {
+ fn decode<'a, 'tcx, M: Metadata<'a, 'tcx>>(self, metadata: M) -> T::Value<'tcx>
+ where
+ T::Value<'tcx>: Decodable<DecodeContext<'a, 'tcx>>,
+ {
+ let mut dcx = metadata.decoder(self.position.get());
+ dcx.lazy_state = LazyState::NodeStart(self.position);
+ T::Value::decode(&mut dcx)
+ }
+}
+
+struct DecodeIterator<'a, 'tcx, T> {
+ elem_counter: std::ops::Range<usize>,
+ dcx: DecodeContext<'a, 'tcx>,
+ _phantom: PhantomData<fn() -> T>,
+}
+
+impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> Iterator for DecodeIterator<'a, 'tcx, T> {
+ type Item = T;
+
+ #[inline(always)]
+ fn next(&mut self) -> Option<Self::Item> {
+ self.elem_counter.next().map(|_| T::decode(&mut self.dcx))
+ }
+
+ #[inline(always)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.elem_counter.size_hint()
+ }
+}
+
+impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> ExactSizeIterator
+ for DecodeIterator<'a, 'tcx, T>
+{
+ fn len(&self) -> usize {
+ self.elem_counter.len()
+ }
+}
+
+unsafe impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> TrustedLen
+ for DecodeIterator<'a, 'tcx, T>
+{
+}
+
+impl<T: ParameterizedOverTcx> LazyArray<T> {
+ fn decode<'a, 'tcx, M: Metadata<'a, 'tcx>>(
+ self,
+ metadata: M,
+ ) -> DecodeIterator<'a, 'tcx, T::Value<'tcx>>
+ where
+ T::Value<'tcx>: Decodable<DecodeContext<'a, 'tcx>>,
+ {
+ let mut dcx = metadata.decoder(self.position.get());
+ dcx.lazy_state = LazyState::NodeStart(self.position);
+ DecodeIterator { elem_counter: (0..self.num_elems), dcx, _phantom: PhantomData }
+ }
+}
+
+impl<'a, 'tcx> DecodeContext<'a, 'tcx> {
+ #[inline]
+ fn tcx(&self) -> TyCtxt<'tcx> {
+ debug_assert!(self.tcx.is_some(), "missing TyCtxt in DecodeContext");
+ self.tcx.unwrap()
+ }
+
+ #[inline]
+ pub fn blob(&self) -> &'a MetadataBlob {
+ self.blob
+ }
+
+ #[inline]
+ pub fn cdata(&self) -> CrateMetadataRef<'a> {
+ debug_assert!(self.cdata.is_some(), "missing CrateMetadata in DecodeContext");
+ self.cdata.unwrap()
+ }
+
+ #[inline]
+ fn map_encoded_cnum_to_current(&self, cnum: CrateNum) -> CrateNum {
+ self.cdata().map_encoded_cnum_to_current(cnum)
+ }
+
+ #[inline]
+ fn read_lazy_offset_then<T>(&mut self, f: impl Fn(NonZeroUsize) -> T) -> T {
+ let distance = self.read_usize();
+ let position = match self.lazy_state {
+ LazyState::NoNode => bug!("read_lazy_with_meta: outside of a metadata node"),
+ LazyState::NodeStart(start) => {
+ let start = start.get();
+ assert!(distance <= start);
+ start - distance
+ }
+ LazyState::Previous(last_pos) => last_pos.get() + distance,
+ };
+ let position = NonZeroUsize::new(position).unwrap();
+ self.lazy_state = LazyState::Previous(position);
+ f(position)
+ }
+
+ fn read_lazy<T>(&mut self) -> LazyValue<T> {
+ self.read_lazy_offset_then(|pos| LazyValue::from_position(pos))
+ }
+
+ fn read_lazy_array<T>(&mut self, len: usize) -> LazyArray<T> {
+ self.read_lazy_offset_then(|pos| LazyArray::from_position_and_num_elems(pos, len))
+ }
+
+ fn read_lazy_table<I, T>(&mut self, len: usize) -> LazyTable<I, T> {
+ self.read_lazy_offset_then(|pos| LazyTable::from_position_and_encoded_size(pos, len))
+ }
+
+ #[inline]
+ pub fn read_raw_bytes(&mut self, len: usize) -> &[u8] {
+ self.opaque.read_raw_bytes(len)
+ }
+}
+
+impl<'a, 'tcx> TyDecoder for DecodeContext<'a, 'tcx> {
+ const CLEAR_CROSS_CRATE: bool = true;
+
+ type I = TyCtxt<'tcx>;
+
+ #[inline]
+ fn interner(&self) -> Self::I {
+ self.tcx()
+ }
+
+ #[inline]
+ fn peek_byte(&self) -> u8 {
+ self.opaque.data[self.opaque.position()]
+ }
+
+ #[inline]
+ fn position(&self) -> usize {
+ self.opaque.position()
+ }
+
+ fn cached_ty_for_shorthand<F>(&mut self, shorthand: usize, or_insert_with: F) -> Ty<'tcx>
+ where
+ F: FnOnce(&mut Self) -> Ty<'tcx>,
+ {
+ let tcx = self.tcx();
+
+ let key = ty::CReaderCacheKey { cnum: Some(self.cdata().cnum), pos: shorthand };
+
+ if let Some(&ty) = tcx.ty_rcache.borrow().get(&key) {
+ return ty;
+ }
+
+ let ty = or_insert_with(self);
+ tcx.ty_rcache.borrow_mut().insert(key, ty);
+ ty
+ }
+
+ fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
+ where
+ F: FnOnce(&mut Self) -> R,
+ {
+ let new_opaque = MemDecoder::new(self.opaque.data, pos);
+ let old_opaque = mem::replace(&mut self.opaque, new_opaque);
+ let old_state = mem::replace(&mut self.lazy_state, LazyState::NoNode);
+ let r = f(self);
+ self.opaque = old_opaque;
+ self.lazy_state = old_state;
+ r
+ }
+
+ fn decode_alloc_id(&mut self) -> rustc_middle::mir::interpret::AllocId {
+ if let Some(alloc_decoding_session) = self.alloc_decoding_session {
+ alloc_decoding_session.decode_alloc_id(self)
+ } else {
+ bug!("Attempting to decode interpret::AllocId without CrateMetadata")
+ }
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for CrateNum {
+ fn decode(d: &mut DecodeContext<'a, 'tcx>) -> CrateNum {
+ let cnum = CrateNum::from_u32(d.read_u32());
+ d.map_encoded_cnum_to_current(cnum)
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for DefIndex {
+ fn decode(d: &mut DecodeContext<'a, 'tcx>) -> DefIndex {
+ DefIndex::from_u32(d.read_u32())
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for ExpnIndex {
+ fn decode(d: &mut DecodeContext<'a, 'tcx>) -> ExpnIndex {
+ ExpnIndex::from_u32(d.read_u32())
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for SyntaxContext {
+ fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> SyntaxContext {
+ let cdata = decoder.cdata();
+ let sess = decoder.sess.unwrap();
+ let cname = cdata.root.name;
+ rustc_span::hygiene::decode_syntax_context(decoder, &cdata.hygiene_context, |_, id| {
+ debug!("SpecializedDecoder<SyntaxContext>: decoding {}", id);
+ cdata
+ .root
+ .syntax_contexts
+ .get(cdata, id)
+ .unwrap_or_else(|| panic!("Missing SyntaxContext {:?} for crate {:?}", id, cname))
+ .decode((cdata, sess))
+ })
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for ExpnId {
+ fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> ExpnId {
+ let local_cdata = decoder.cdata();
+ let sess = decoder.sess.unwrap();
+
+ let cnum = CrateNum::decode(decoder);
+ let index = u32::decode(decoder);
+
+ let expn_id = rustc_span::hygiene::decode_expn_id(cnum, index, |expn_id| {
+ let ExpnId { krate: cnum, local_id: index } = expn_id;
+ // Lookup local `ExpnData`s in our own crate data. Foreign `ExpnData`s
+ // are stored in the owning crate, to avoid duplication.
+ debug_assert_ne!(cnum, LOCAL_CRATE);
+ let crate_data = if cnum == local_cdata.cnum {
+ local_cdata
+ } else {
+ local_cdata.cstore.get_crate_data(cnum)
+ };
+ let expn_data = crate_data
+ .root
+ .expn_data
+ .get(crate_data, index)
+ .unwrap()
+ .decode((crate_data, sess));
+ let expn_hash = crate_data
+ .root
+ .expn_hashes
+ .get(crate_data, index)
+ .unwrap()
+ .decode((crate_data, sess));
+ (expn_data, expn_hash)
+ });
+ expn_id
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for Span {
+ fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Span {
+ let ctxt = SyntaxContext::decode(decoder);
+ let tag = u8::decode(decoder);
+
+ if tag == TAG_PARTIAL_SPAN {
+ return DUMMY_SP.with_ctxt(ctxt);
+ }
+
+ debug_assert!(tag == TAG_VALID_SPAN_LOCAL || tag == TAG_VALID_SPAN_FOREIGN);
+
+ let lo = BytePos::decode(decoder);
+ let len = BytePos::decode(decoder);
+ let hi = lo + len;
+
+ let Some(sess) = decoder.sess else {
+ bug!("Cannot decode Span without Session.")
+ };
+
+ // There are two possibilities here:
+ // 1. This is a 'local span', which is located inside a `SourceFile`
+ // that came from this crate. In this case, we use the source map data
+ // encoded in this crate. This branch should be taken nearly all of the time.
+ // 2. This is a 'foreign span', which is located inside a `SourceFile`
+ // that came from a *different* crate (some crate upstream of the one
+ // whose metadata we're looking at). For example, consider this dependency graph:
+ //
+ // A -> B -> C
+ //
+ // Suppose that we're currently compiling crate A, and start deserializing
+ // metadata from crate B. When we deserialize a Span from crate B's metadata,
+ // there are two possibilities:
+ //
+ // 1. The span references a file from crate B. This makes it a 'local' span,
+ // which means that we can use crate B's serialized source map information.
+ // 2. The span references a file from crate C. This makes it a 'foreign' span,
+ // which means we need to use Crate *C* (not crate B) to determine the source
+ // map information. We only record source map information for a file in the
+ // crate that 'owns' it, so deserializing a Span may require us to look at
+ // a transitive dependency.
+ //
+ // When we encode a foreign span, we adjust its 'lo' and 'high' values
+ // to be based on the *foreign* crate (e.g. crate C), not the crate
+ // we are writing metadata for (e.g. crate B). This allows us to
+ // treat the 'local' and 'foreign' cases almost identically during deserialization:
+ // we can call `imported_source_files` for the proper crate, and binary search
+ // through the returned slice using our span.
+ let imported_source_files = if tag == TAG_VALID_SPAN_LOCAL {
+ decoder.cdata().imported_source_files(sess)
+ } else {
+ // When we encode a proc-macro crate, all `Span`s should be encoded
+ // with `TAG_VALID_SPAN_LOCAL`
+ if decoder.cdata().root.is_proc_macro_crate() {
+ // Decode `CrateNum` as u32 - using `CrateNum::decode` will ICE
+ // since we don't have `cnum_map` populated.
+ let cnum = u32::decode(decoder);
+ panic!(
+ "Decoding of crate {:?} tried to access proc-macro dep {:?}",
+ decoder.cdata().root.name,
+ cnum
+ );
+ }
+ // tag is TAG_VALID_SPAN_FOREIGN, checked by `debug_assert` above
+ let cnum = CrateNum::decode(decoder);
+ debug!(
+ "SpecializedDecoder<Span>::specialized_decode: loading source files from cnum {:?}",
+ cnum
+ );
+
+ // Decoding 'foreign' spans should be rare enough that it's
+ // not worth it to maintain a per-CrateNum cache for `last_source_file_index`.
+ // We just set it to 0, to ensure that we don't try to access something out
+ // of bounds for our initial 'guess'
+ decoder.last_source_file_index = 0;
+
+ let foreign_data = decoder.cdata().cstore.get_crate_data(cnum);
+ foreign_data.imported_source_files(sess)
+ };
+
+ let source_file = {
+ // Optimize for the case that most spans within a translated item
+ // originate from the same source_file.
+ let last_source_file = &imported_source_files[decoder.last_source_file_index];
+
+ if lo >= last_source_file.original_start_pos && lo <= last_source_file.original_end_pos
+ {
+ last_source_file
+ } else {
+ let index = imported_source_files
+ .binary_search_by_key(&lo, |source_file| source_file.original_start_pos)
+ .unwrap_or_else(|index| index - 1);
+
+ // Don't try to cache the index for foreign spans,
+ // as this would require a map from CrateNums to indices
+ if tag == TAG_VALID_SPAN_LOCAL {
+ decoder.last_source_file_index = index;
+ }
+ &imported_source_files[index]
+ }
+ };
+
+ // Make sure our binary search above is correct.
+ debug_assert!(
+ lo >= source_file.original_start_pos && lo <= source_file.original_end_pos,
+ "Bad binary search: lo={:?} source_file.original_start_pos={:?} source_file.original_end_pos={:?}",
+ lo,
+ source_file.original_start_pos,
+ source_file.original_end_pos
+ );
+
+ // Make sure we correctly filtered out invalid spans during encoding
+ debug_assert!(
+ hi >= source_file.original_start_pos && hi <= source_file.original_end_pos,
+ "Bad binary search: hi={:?} source_file.original_start_pos={:?} source_file.original_end_pos={:?}",
+ hi,
+ source_file.original_start_pos,
+ source_file.original_end_pos
+ );
+
+ let lo =
+ (lo + source_file.translated_source_file.start_pos) - source_file.original_start_pos;
+ let hi =
+ (hi + source_file.translated_source_file.start_pos) - source_file.original_start_pos;
+
+ // Do not try to decode parent for foreign spans.
+ Span::new(lo, hi, ctxt, None)
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for &'tcx [ty::abstract_const::Node<'tcx>] {
+ fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Self {
+ ty::codec::RefDecodable::decode(d)
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for &'tcx [(ty::Predicate<'tcx>, Span)] {
+ fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Self {
+ ty::codec::RefDecodable::decode(d)
+ }
+}
+
+impl<'a, 'tcx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyValue<T> {
+ fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
+ decoder.read_lazy()
+ }
+}
+
+impl<'a, 'tcx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyArray<T> {
+ fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
+ let len = decoder.read_usize();
+ if len == 0 { LazyArray::empty() } else { decoder.read_lazy_array(len) }
+ }
+}
+
+impl<'a, 'tcx, I: Idx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyTable<I, T> {
+ fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
+ let len = decoder.read_usize();
+ decoder.read_lazy_table(len)
+ }
+}
+
+implement_ty_decoder!(DecodeContext<'a, 'tcx>);
+
+impl MetadataBlob {
+ pub(crate) fn new(metadata_ref: MetadataRef) -> MetadataBlob {
+ MetadataBlob(Lrc::new(metadata_ref))
+ }
+
+ pub(crate) fn is_compatible(&self) -> bool {
+ self.blob().starts_with(METADATA_HEADER)
+ }
+
+ pub(crate) fn get_rustc_version(&self) -> String {
+ LazyValue::<String>::from_position(NonZeroUsize::new(METADATA_HEADER.len() + 4).unwrap())
+ .decode(self)
+ }
+
+ pub(crate) fn get_root(&self) -> CrateRoot {
+ let slice = &self.blob()[..];
+ let offset = METADATA_HEADER.len();
+ let pos = (((slice[offset + 0] as u32) << 24)
+ | ((slice[offset + 1] as u32) << 16)
+ | ((slice[offset + 2] as u32) << 8)
+ | ((slice[offset + 3] as u32) << 0)) as usize;
+ LazyValue::<CrateRoot>::from_position(NonZeroUsize::new(pos).unwrap()).decode(self)
+ }
+
+ pub(crate) fn list_crate_metadata(&self, out: &mut dyn io::Write) -> io::Result<()> {
+ let root = self.get_root();
+ writeln!(out, "Crate info:")?;
+ writeln!(out, "name {}{}", root.name, root.extra_filename)?;
+ writeln!(out, "hash {} stable_crate_id {:?}", root.hash, root.stable_crate_id)?;
+ writeln!(out, "proc_macro {:?}", root.proc_macro_data.is_some())?;
+ writeln!(out, "=External Dependencies=")?;
+ for (i, dep) in root.crate_deps.decode(self).enumerate() {
+ writeln!(
+ out,
+ "{} {}{} hash {} host_hash {:?} kind {:?}",
+ i + 1,
+ dep.name,
+ dep.extra_filename,
+ dep.hash,
+ dep.host_hash,
+ dep.kind
+ )?;
+ }
+ write!(out, "\n")?;
+ Ok(())
+ }
+}
+
+impl CrateRoot {
+ pub(crate) fn is_proc_macro_crate(&self) -> bool {
+ self.proc_macro_data.is_some()
+ }
+
+ pub(crate) fn name(&self) -> Symbol {
+ self.name
+ }
+
+ pub(crate) fn hash(&self) -> Svh {
+ self.hash
+ }
+
+ pub(crate) fn stable_crate_id(&self) -> StableCrateId {
+ self.stable_crate_id
+ }
+
+ pub(crate) fn triple(&self) -> &TargetTriple {
+ &self.triple
+ }
+
+ pub(crate) fn decode_crate_deps<'a>(
+ &self,
+ metadata: &'a MetadataBlob,
+ ) -> impl ExactSizeIterator<Item = CrateDep> + Captures<'a> {
+ self.crate_deps.decode(metadata)
+ }
+}
+
+impl<'a, 'tcx> CrateMetadataRef<'a> {
+ fn raw_proc_macro(self, id: DefIndex) -> &'a ProcMacro {
+ // DefIndex's in root.proc_macro_data have a one-to-one correspondence
+ // with items in 'raw_proc_macros'.
+ let pos = self
+ .root
+ .proc_macro_data
+ .as_ref()
+ .unwrap()
+ .macros
+ .decode(self)
+ .position(|i| i == id)
+ .unwrap();
+ &self.raw_proc_macros.unwrap()[pos]
+ }
+
+ fn opt_item_name(self, item_index: DefIndex) -> Option<Symbol> {
+ self.def_key(item_index).disambiguated_data.data.get_opt_name()
+ }
+
+ fn item_name(self, item_index: DefIndex) -> Symbol {
+ self.opt_item_name(item_index).expect("no encoded ident for item")
+ }
+
+ fn opt_item_ident(self, item_index: DefIndex, sess: &Session) -> Option<Ident> {
+ let name = self.opt_item_name(item_index)?;
+ let span =
+ self.root.tables.def_ident_span.get(self, item_index).unwrap().decode((self, sess));
+ Some(Ident::new(name, span))
+ }
+
+ fn item_ident(self, item_index: DefIndex, sess: &Session) -> Ident {
+ self.opt_item_ident(item_index, sess).expect("no encoded ident for item")
+ }
+
+ fn maybe_kind(self, item_id: DefIndex) -> Option<EntryKind> {
+ self.root.tables.kind.get(self, item_id).map(|k| k.decode(self))
+ }
+
+ #[inline]
+ pub(super) fn map_encoded_cnum_to_current(self, cnum: CrateNum) -> CrateNum {
+ if cnum == LOCAL_CRATE { self.cnum } else { self.cnum_map[cnum] }
+ }
+
+ fn kind(self, item_id: DefIndex) -> EntryKind {
+ self.maybe_kind(item_id).unwrap_or_else(|| {
+ bug!(
+ "CrateMetadata::kind({:?}): id not found, in crate {:?} with number {}",
+ item_id,
+ self.root.name,
+ self.cnum,
+ )
+ })
+ }
+
+ fn def_kind(self, item_id: DefIndex) -> DefKind {
+ self.root.tables.opt_def_kind.get(self, item_id).unwrap_or_else(|| {
+ bug!(
+ "CrateMetadata::def_kind({:?}): id not found, in crate {:?} with number {}",
+ item_id,
+ self.root.name,
+ self.cnum,
+ )
+ })
+ }
+
+ fn get_span(self, index: DefIndex, sess: &Session) -> Span {
+ self.root
+ .tables
+ .def_span
+ .get(self, index)
+ .unwrap_or_else(|| panic!("Missing span for {:?}", index))
+ .decode((self, sess))
+ }
+
+ fn load_proc_macro(self, id: DefIndex, sess: &Session) -> SyntaxExtension {
+ let (name, kind, helper_attrs) = match *self.raw_proc_macro(id) {
+ ProcMacro::CustomDerive { trait_name, attributes, client } => {
+ let helper_attrs =
+ attributes.iter().cloned().map(Symbol::intern).collect::<Vec<_>>();
+ (
+ trait_name,
+ SyntaxExtensionKind::Derive(Box::new(DeriveProcMacro { client })),
+ helper_attrs,
+ )
+ }
+ ProcMacro::Attr { name, client } => {
+ (name, SyntaxExtensionKind::Attr(Box::new(AttrProcMacro { client })), Vec::new())
+ }
+ ProcMacro::Bang { name, client } => {
+ (name, SyntaxExtensionKind::Bang(Box::new(BangProcMacro { client })), Vec::new())
+ }
+ };
+
+ let attrs: Vec<_> = self.get_item_attrs(id, sess).collect();
+ SyntaxExtension::new(
+ sess,
+ kind,
+ self.get_span(id, sess),
+ helper_attrs,
+ self.root.edition,
+ Symbol::intern(name),
+ &attrs,
+ )
+ }
+
+ fn get_variant(self, kind: &EntryKind, index: DefIndex, parent_did: DefId) -> ty::VariantDef {
+ let data = match kind {
+ EntryKind::Variant(data) | EntryKind::Struct(data) | EntryKind::Union(data) => {
+ data.decode(self)
+ }
+ _ => bug!(),
+ };
+
+ let adt_kind = match kind {
+ EntryKind::Variant(_) => ty::AdtKind::Enum,
+ EntryKind::Struct(..) => ty::AdtKind::Struct,
+ EntryKind::Union(..) => ty::AdtKind::Union,
+ _ => bug!(),
+ };
+
+ let variant_did =
+ if adt_kind == ty::AdtKind::Enum { Some(self.local_def_id(index)) } else { None };
+ let ctor_did = data.ctor.map(|index| self.local_def_id(index));
+
+ ty::VariantDef::new(
+ self.item_name(index),
+ variant_did,
+ ctor_did,
+ data.discr,
+ self.root
+ .tables
+ .children
+ .get(self, index)
+ .unwrap_or_else(LazyArray::empty)
+ .decode(self)
+ .map(|index| ty::FieldDef {
+ did: self.local_def_id(index),
+ name: self.item_name(index),
+ vis: self.get_visibility(index),
+ })
+ .collect(),
+ data.ctor_kind,
+ adt_kind,
+ parent_did,
+ false,
+ data.is_non_exhaustive,
+ )
+ }
+
+ fn get_adt_def(self, item_id: DefIndex, tcx: TyCtxt<'tcx>) -> ty::AdtDef<'tcx> {
+ let kind = self.kind(item_id);
+ let did = self.local_def_id(item_id);
+
+ let adt_kind = match kind {
+ EntryKind::Enum => ty::AdtKind::Enum,
+ EntryKind::Struct(_) => ty::AdtKind::Struct,
+ EntryKind::Union(_) => ty::AdtKind::Union,
+ _ => bug!("get_adt_def called on a non-ADT {:?}", did),
+ };
+ let repr = self.root.tables.repr_options.get(self, item_id).unwrap().decode(self);
+
+ let variants = if let ty::AdtKind::Enum = adt_kind {
+ self.root
+ .tables
+ .children
+ .get(self, item_id)
+ .unwrap_or_else(LazyArray::empty)
+ .decode(self)
+ .map(|index| self.get_variant(&self.kind(index), index, did))
+ .collect()
+ } else {
+ std::iter::once(self.get_variant(&kind, item_id, did)).collect()
+ };
+
+ tcx.alloc_adt_def(did, adt_kind, variants, repr)
+ }
+
+ fn get_generics(self, item_id: DefIndex, sess: &Session) -> ty::Generics {
+ self.root.tables.generics_of.get(self, item_id).unwrap().decode((self, sess))
+ }
+
+ fn get_visibility(self, id: DefIndex) -> ty::Visibility {
+ self.root.tables.visibility.get(self, id).unwrap().decode(self)
+ }
+
+ fn get_trait_item_def_id(self, id: DefIndex) -> Option<DefId> {
+ self.root.tables.trait_item_def_id.get(self, id).map(|d| d.decode_from_cdata(self))
+ }
+
+ fn get_expn_that_defined(self, id: DefIndex, sess: &Session) -> ExpnId {
+ self.root.tables.expn_that_defined.get(self, id).unwrap().decode((self, sess))
+ }
+
+ fn get_debugger_visualizers(self) -> Vec<rustc_span::DebuggerVisualizerFile> {
+ self.root.debugger_visualizers.decode(self).collect::<Vec<_>>()
+ }
+
+ /// Iterates over all the stability attributes in the given crate.
+ fn get_lib_features(self, tcx: TyCtxt<'tcx>) -> &'tcx [(Symbol, Option<Symbol>)] {
+ tcx.arena.alloc_from_iter(self.root.lib_features.decode(self))
+ }
+
+ /// Iterates over the stability implications in the given crate (when a `#[unstable]` attribute
+ /// has an `implied_by` meta item, then the mapping from the implied feature to the actual
+ /// feature is a stability implication).
+ fn get_stability_implications(self, tcx: TyCtxt<'tcx>) -> &'tcx [(Symbol, Symbol)] {
+ tcx.arena.alloc_from_iter(self.root.stability_implications.decode(self))
+ }
+
+ /// Iterates over the language items in the given crate.
+ fn get_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, usize)] {
+ tcx.arena.alloc_from_iter(
+ self.root
+ .lang_items
+ .decode(self)
+ .map(move |(def_index, index)| (self.local_def_id(def_index), index)),
+ )
+ }
+
+ /// Iterates over the diagnostic items in the given crate.
+ fn get_diagnostic_items(self) -> DiagnosticItems {
+ let mut id_to_name = FxHashMap::default();
+ let name_to_id = self
+ .root
+ .diagnostic_items
+ .decode(self)
+ .map(|(name, def_index)| {
+ let id = self.local_def_id(def_index);
+ id_to_name.insert(id, name);
+ (name, id)
+ })
+ .collect();
+ DiagnosticItems { id_to_name, name_to_id }
+ }
+
+ /// Iterates over all named children of the given module,
+ /// including both proper items and reexports.
+ /// Module here is understood in name resolution sense - it can be a `mod` item,
+ /// or a crate root, or an enum, or a trait.
+ fn for_each_module_child(
+ self,
+ id: DefIndex,
+ mut callback: impl FnMut(ModChild),
+ sess: &Session,
+ ) {
+ if let Some(data) = &self.root.proc_macro_data {
+ // If we are loading as a proc macro, we want to return
+ // the view of this crate as a proc macro crate.
+ if id == CRATE_DEF_INDEX {
+ for def_index in data.macros.decode(self) {
+ let raw_macro = self.raw_proc_macro(def_index);
+ let res = Res::Def(
+ DefKind::Macro(macro_kind(raw_macro)),
+ self.local_def_id(def_index),
+ );
+ let ident = self.item_ident(def_index, sess);
+ callback(ModChild {
+ ident,
+ res,
+ vis: ty::Visibility::Public,
+ span: ident.span,
+ macro_rules: false,
+ });
+ }
+ }
+ return;
+ }
+
+ // Iterate over all children.
+ if let Some(children) = self.root.tables.children.get(self, id) {
+ for child_index in children.decode((self, sess)) {
+ let ident = self.item_ident(child_index, sess);
+ let kind = self.def_kind(child_index);
+ let def_id = self.local_def_id(child_index);
+ let res = Res::Def(kind, def_id);
+ let vis = self.get_visibility(child_index);
+ let span = self.get_span(child_index, sess);
+ let macro_rules = match kind {
+ DefKind::Macro(..) => match self.kind(child_index) {
+ EntryKind::MacroDef(_, macro_rules) => macro_rules,
+ _ => unreachable!(),
+ },
+ _ => false,
+ };
+
+ callback(ModChild { ident, res, vis, span, macro_rules });
+
+ // For non-re-export structs and variants add their constructors to children.
+ // Re-export lists automatically contain constructors when necessary.
+ match kind {
+ DefKind::Struct => {
+ if let Some((ctor_def_id, ctor_kind)) =
+ self.get_ctor_def_id_and_kind(child_index)
+ {
+ let ctor_res =
+ Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id);
+ let vis = self.get_visibility(ctor_def_id.index);
+ callback(ModChild {
+ ident,
+ res: ctor_res,
+ vis,
+ span,
+ macro_rules: false,
+ });
+ }
+ }
+ DefKind::Variant => {
+ // Braced variants, unlike structs, generate unusable names in
+ // value namespace, they are reserved for possible future use.
+ // It's ok to use the variant's id as a ctor id since an
+ // error will be reported on any use of such resolution anyway.
+ let (ctor_def_id, ctor_kind) = self
+ .get_ctor_def_id_and_kind(child_index)
+ .unwrap_or((def_id, CtorKind::Fictive));
+ let ctor_res =
+ Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
+ let mut vis = self.get_visibility(ctor_def_id.index);
+ if ctor_def_id == def_id && vis.is_public() {
+ // For non-exhaustive variants lower the constructor visibility to
+ // within the crate. We only need this for fictive constructors,
+ // for other constructors correct visibilities
+ // were already encoded in metadata.
+ let mut attrs = self.get_item_attrs(def_id.index, sess);
+ if attrs.any(|item| item.has_name(sym::non_exhaustive)) {
+ let crate_def_id = self.local_def_id(CRATE_DEF_INDEX);
+ vis = ty::Visibility::Restricted(crate_def_id);
+ }
+ }
+ callback(ModChild { ident, res: ctor_res, vis, span, macro_rules: false });
+ }
+ _ => {}
+ }
+ }
+ }
+
+ match self.kind(id) {
+ EntryKind::Mod(exports) => {
+ for exp in exports.decode((self, sess)) {
+ callback(exp);
+ }
+ }
+ EntryKind::Enum | EntryKind::Trait => {}
+ _ => bug!("`for_each_module_child` is called on a non-module: {:?}", self.def_kind(id)),
+ }
+ }
+
+ fn is_ctfe_mir_available(self, id: DefIndex) -> bool {
+ self.root.tables.mir_for_ctfe.get(self, id).is_some()
+ }
+
+ fn is_item_mir_available(self, id: DefIndex) -> bool {
+ self.root.tables.optimized_mir.get(self, id).is_some()
+ }
+
+ fn module_expansion(self, id: DefIndex, sess: &Session) -> ExpnId {
+ match self.kind(id) {
+ EntryKind::Mod(_) | EntryKind::Enum | EntryKind::Trait => {
+ self.get_expn_that_defined(id, sess)
+ }
+ _ => panic!("Expected module, found {:?}", self.local_def_id(id)),
+ }
+ }
+
+ fn get_fn_has_self_parameter(self, id: DefIndex) -> bool {
+ match self.kind(id) {
+ EntryKind::AssocFn { has_self, .. } => has_self,
+ _ => false,
+ }
+ }
+
+ fn get_associated_item_def_ids(
+ self,
+ id: DefIndex,
+ sess: &'a Session,
+ ) -> impl Iterator<Item = DefId> + 'a {
+ self.root
+ .tables
+ .children
+ .get(self, id)
+ .unwrap_or_else(LazyArray::empty)
+ .decode((self, sess))
+ .map(move |child_index| self.local_def_id(child_index))
+ }
+
+ fn get_associated_item(self, id: DefIndex) -> ty::AssocItem {
+ let name = self.item_name(id);
+
+ let (kind, container, has_self) = match self.kind(id) {
+ EntryKind::AssocConst(container) => (ty::AssocKind::Const, container, false),
+ EntryKind::AssocFn { container, has_self } => (ty::AssocKind::Fn, container, has_self),
+ EntryKind::AssocType(container) => (ty::AssocKind::Type, container, false),
+ _ => bug!("cannot get associated-item of `{:?}`", id),
+ };
+
+ ty::AssocItem {
+ name,
+ kind,
+ def_id: self.local_def_id(id),
+ trait_item_def_id: self.get_trait_item_def_id(id),
+ container,
+ fn_has_self_parameter: has_self,
+ }
+ }
+
+ fn get_ctor_def_id_and_kind(self, node_id: DefIndex) -> Option<(DefId, CtorKind)> {
+ match self.kind(node_id) {
+ EntryKind::Struct(data) | EntryKind::Variant(data) => {
+ let vdata = data.decode(self);
+ vdata.ctor.map(|index| (self.local_def_id(index), vdata.ctor_kind))
+ }
+ _ => None,
+ }
+ }
+
+ fn get_item_attrs(
+ self,
+ id: DefIndex,
+ sess: &'a Session,
+ ) -> impl Iterator<Item = ast::Attribute> + 'a {
+ self.root
+ .tables
+ .attributes
+ .get(self, id)
+ .unwrap_or_else(|| {
+ // Structure and variant constructors don't have any attributes encoded for them,
+ // but we assume that someone passing a constructor ID actually wants to look at
+ // the attributes on the corresponding struct or variant.
+ let def_key = self.def_key(id);
+ assert_eq!(def_key.disambiguated_data.data, DefPathData::Ctor);
+ let parent_id = def_key.parent.expect("no parent for a constructor");
+ self.root
+ .tables
+ .attributes
+ .get(self, parent_id)
+ .expect("no encoded attributes for a structure or variant")
+ })
+ .decode((self, sess))
+ }
+
+ fn get_struct_field_names(
+ self,
+ id: DefIndex,
+ sess: &'a Session,
+ ) -> impl Iterator<Item = Spanned<Symbol>> + 'a {
+ self.root
+ .tables
+ .children
+ .get(self, id)
+ .unwrap_or_else(LazyArray::empty)
+ .decode(self)
+ .map(move |index| respan(self.get_span(index, sess), self.item_name(index)))
+ }
+
+ fn get_struct_field_visibilities(self, id: DefIndex) -> impl Iterator<Item = Visibility> + 'a {
+ self.root
+ .tables
+ .children
+ .get(self, id)
+ .unwrap_or_else(LazyArray::empty)
+ .decode(self)
+ .map(move |field_index| self.get_visibility(field_index))
+ }
+
+ fn get_inherent_implementations_for_type(
+ self,
+ tcx: TyCtxt<'tcx>,
+ id: DefIndex,
+ ) -> &'tcx [DefId] {
+ tcx.arena.alloc_from_iter(
+ self.root
+ .tables
+ .inherent_impls
+ .get(self, id)
+ .unwrap_or_else(LazyArray::empty)
+ .decode(self)
+ .map(|index| self.local_def_id(index)),
+ )
+ }
+
+ /// Decodes all inherent impls in the crate (for rustdoc).
+ fn get_inherent_impls(self) -> impl Iterator<Item = (DefId, DefId)> + 'a {
+ (0..self.root.tables.inherent_impls.size()).flat_map(move |i| {
+ let ty_index = DefIndex::from_usize(i);
+ let ty_def_id = self.local_def_id(ty_index);
+ self.root
+ .tables
+ .inherent_impls
+ .get(self, ty_index)
+ .unwrap_or_else(LazyArray::empty)
+ .decode(self)
+ .map(move |impl_index| (ty_def_id, self.local_def_id(impl_index)))
+ })
+ }
+
+ /// Decodes all traits in the crate (for rustdoc and rustc diagnostics).
+ fn get_traits(self) -> impl Iterator<Item = DefId> + 'a {
+ self.root.traits.decode(self).map(move |index| self.local_def_id(index))
+ }
+
+ /// Decodes all trait impls in the crate (for rustdoc).
+ fn get_trait_impls(self) -> impl Iterator<Item = (DefId, DefId, Option<SimplifiedType>)> + 'a {
+ self.cdata.trait_impls.iter().flat_map(move |(&(trait_cnum_raw, trait_index), impls)| {
+ let trait_def_id = DefId {
+ krate: self.cnum_map[CrateNum::from_u32(trait_cnum_raw)],
+ index: trait_index,
+ };
+ impls.decode(self).map(move |(impl_index, simplified_self_ty)| {
+ (trait_def_id, self.local_def_id(impl_index), simplified_self_ty)
+ })
+ })
+ }
+
+ fn get_all_incoherent_impls(self) -> impl Iterator<Item = DefId> + 'a {
+ self.cdata
+ .incoherent_impls
+ .values()
+ .flat_map(move |impls| impls.decode(self).map(move |idx| self.local_def_id(idx)))
+ }
+
+ fn get_incoherent_impls(self, tcx: TyCtxt<'tcx>, simp: SimplifiedType) -> &'tcx [DefId] {
+ if let Some(impls) = self.cdata.incoherent_impls.get(&simp) {
+ tcx.arena.alloc_from_iter(impls.decode(self).map(|idx| self.local_def_id(idx)))
+ } else {
+ &[]
+ }
+ }
+
+ fn get_implementations_of_trait(
+ self,
+ tcx: TyCtxt<'tcx>,
+ trait_def_id: DefId,
+ ) -> &'tcx [(DefId, Option<SimplifiedType>)] {
+ if self.trait_impls.is_empty() {
+ return &[];
+ }
+
+ // Do a reverse lookup beforehand to avoid touching the crate_num
+ // hash map in the loop below.
+ let key = match self.reverse_translate_def_id(trait_def_id) {
+ Some(def_id) => (def_id.krate.as_u32(), def_id.index),
+ None => return &[],
+ };
+
+ if let Some(impls) = self.trait_impls.get(&key) {
+ tcx.arena.alloc_from_iter(
+ impls
+ .decode(self)
+ .map(|(idx, simplified_self_ty)| (self.local_def_id(idx), simplified_self_ty)),
+ )
+ } else {
+ &[]
+ }
+ }
+
+ fn get_native_libraries(self, sess: &'a Session) -> impl Iterator<Item = NativeLib> + 'a {
+ self.root.native_libraries.decode((self, sess))
+ }
+
+ fn get_proc_macro_quoted_span(self, index: usize, sess: &Session) -> Span {
+ self.root
+ .tables
+ .proc_macro_quoted_spans
+ .get(self, index)
+ .unwrap_or_else(|| panic!("Missing proc macro quoted span: {:?}", index))
+ .decode((self, sess))
+ }
+
+ fn get_foreign_modules(self, sess: &'a Session) -> impl Iterator<Item = ForeignModule> + '_ {
+ self.root.foreign_modules.decode((self, sess))
+ }
+
+ fn get_dylib_dependency_formats(
+ self,
+ tcx: TyCtxt<'tcx>,
+ ) -> &'tcx [(CrateNum, LinkagePreference)] {
+ tcx.arena.alloc_from_iter(
+ self.root.dylib_dependency_formats.decode(self).enumerate().flat_map(|(i, link)| {
+ let cnum = CrateNum::new(i + 1);
+ link.map(|link| (self.cnum_map[cnum], link))
+ }),
+ )
+ }
+
+ fn get_missing_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [lang_items::LangItem] {
+ tcx.arena.alloc_from_iter(self.root.lang_items_missing.decode(self))
+ }
+
+ fn exported_symbols(
+ self,
+ tcx: TyCtxt<'tcx>,
+ ) -> &'tcx [(ExportedSymbol<'tcx>, SymbolExportInfo)] {
+ tcx.arena.alloc_from_iter(self.root.exported_symbols.decode((self, tcx)))
+ }
+
+ fn get_macro(self, id: DefIndex, sess: &Session) -> ast::MacroDef {
+ match self.kind(id) {
+ EntryKind::MacroDef(mac_args, macro_rules) => {
+ ast::MacroDef { body: P(mac_args.decode((self, sess))), macro_rules }
+ }
+ _ => bug!(),
+ }
+ }
+
+ fn is_foreign_item(self, id: DefIndex) -> bool {
+ match self.kind(id) {
+ EntryKind::ForeignStatic | EntryKind::ForeignFn => true,
+ _ => false,
+ }
+ }
+
+ #[inline]
+ fn def_key(self, index: DefIndex) -> DefKey {
+ *self
+ .def_key_cache
+ .lock()
+ .entry(index)
+ .or_insert_with(|| self.root.tables.def_keys.get(self, index).unwrap().decode(self))
+ }
+
+ // Returns the path leading to the thing with this `id`.
+ fn def_path(self, id: DefIndex) -> DefPath {
+ debug!("def_path(cnum={:?}, id={:?})", self.cnum, id);
+ DefPath::make(self.cnum, id, |parent| self.def_key(parent))
+ }
+
+ fn def_path_hash_unlocked(
+ self,
+ index: DefIndex,
+ def_path_hashes: &mut FxHashMap<DefIndex, DefPathHash>,
+ ) -> DefPathHash {
+ *def_path_hashes
+ .entry(index)
+ .or_insert_with(|| self.root.tables.def_path_hashes.get(self, index).unwrap())
+ }
+
+ #[inline]
+ fn def_path_hash(self, index: DefIndex) -> DefPathHash {
+ let mut def_path_hashes = self.def_path_hash_cache.lock();
+ self.def_path_hash_unlocked(index, &mut def_path_hashes)
+ }
+
+ #[inline]
+ fn def_path_hash_to_def_index(self, hash: DefPathHash) -> DefIndex {
+ self.def_path_hash_map.def_path_hash_to_def_index(&hash)
+ }
+
+ fn expn_hash_to_expn_id(self, sess: &Session, index_guess: u32, hash: ExpnHash) -> ExpnId {
+ debug_assert_eq!(ExpnId::from_hash(hash), None);
+ let index_guess = ExpnIndex::from_u32(index_guess);
+ let old_hash = self.root.expn_hashes.get(self, index_guess).map(|lazy| lazy.decode(self));
+
+ let index = if old_hash == Some(hash) {
+ // Fast path: the expn and its index is unchanged from the
+ // previous compilation session. There is no need to decode anything
+ // else.
+ index_guess
+ } else {
+ // Slow path: We need to find out the new `DefIndex` of the provided
+ // `DefPathHash`, if its still exists. This requires decoding every `DefPathHash`
+ // stored in this crate.
+ let map = self.cdata.expn_hash_map.get_or_init(|| {
+ let end_id = self.root.expn_hashes.size() as u32;
+ let mut map =
+ UnhashMap::with_capacity_and_hasher(end_id as usize, Default::default());
+ for i in 0..end_id {
+ let i = ExpnIndex::from_u32(i);
+ if let Some(hash) = self.root.expn_hashes.get(self, i) {
+ map.insert(hash.decode(self), i);
+ }
+ }
+ map
+ });
+ map[&hash]
+ };
+
+ let data = self.root.expn_data.get(self, index).unwrap().decode((self, sess));
+ rustc_span::hygiene::register_expn_id(self.cnum, index, data, hash)
+ }
+
+ /// Imports the source_map from an external crate into the source_map of the crate
+ /// currently being compiled (the "local crate").
+ ///
+ /// The import algorithm works analogous to how AST items are inlined from an
+ /// external crate's metadata:
+ /// For every SourceFile in the external source_map an 'inline' copy is created in the
+ /// local source_map. The correspondence relation between external and local
+ /// SourceFiles is recorded in the `ImportedSourceFile` objects returned from this
+ /// function. When an item from an external crate is later inlined into this
+ /// crate, this correspondence information is used to translate the span
+ /// information of the inlined item so that it refers the correct positions in
+ /// the local source_map (see `<decoder::DecodeContext as SpecializedDecoder<Span>>`).
+ ///
+ /// The import algorithm in the function below will reuse SourceFiles already
+ /// existing in the local source_map. For example, even if the SourceFile of some
+ /// source file of libstd gets imported many times, there will only ever be
+ /// one SourceFile object for the corresponding file in the local source_map.
+ ///
+ /// Note that imported SourceFiles do not actually contain the source code of the
+ /// file they represent, just information about length, line breaks, and
+ /// multibyte characters. This information is enough to generate valid debuginfo
+ /// for items inlined from other crates.
+ ///
+ /// Proc macro crates don't currently export spans, so this function does not have
+ /// to work for them.
+ fn imported_source_files(self, sess: &Session) -> &'a [ImportedSourceFile] {
+ fn filter<'a>(sess: &Session, path: Option<&'a Path>) -> Option<&'a Path> {
+ path.filter(|_| {
+ // Only spend time on further checks if we have what to translate *to*.
+ sess.opts.real_rust_source_base_dir.is_some()
+ // Some tests need the translation to be always skipped.
+ && sess.opts.unstable_opts.translate_remapped_path_to_local_path
+ })
+ .filter(|virtual_dir| {
+ // Don't translate away `/rustc/$hash` if we're still remapping to it,
+ // since that means we're still building `std`/`rustc` that need it,
+ // and we don't want the real path to leak into codegen/debuginfo.
+ !sess.opts.remap_path_prefix.iter().any(|(_from, to)| to == virtual_dir)
+ })
+ }
+
+ // Translate the virtual `/rustc/$hash` prefix back to a real directory
+ // that should hold actual sources, where possible.
+ //
+ // NOTE: if you update this, you might need to also update bootstrap's code for generating
+ // the `rust-src` component in `Src::run` in `src/bootstrap/dist.rs`.
+ let virtual_rust_source_base_dir = [
+ filter(sess, option_env!("CFG_VIRTUAL_RUST_SOURCE_BASE_DIR").map(Path::new)),
+ filter(sess, sess.opts.unstable_opts.simulate_remapped_rust_src_base.as_deref()),
+ ];
+
+ let try_to_translate_virtual_to_real = |name: &mut rustc_span::FileName| {
+ debug!(
+ "try_to_translate_virtual_to_real(name={:?}): \
+ virtual_rust_source_base_dir={:?}, real_rust_source_base_dir={:?}",
+ name, virtual_rust_source_base_dir, sess.opts.real_rust_source_base_dir,
+ );
+
+ for virtual_dir in virtual_rust_source_base_dir.iter().flatten() {
+ if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
+ if let rustc_span::FileName::Real(old_name) = name {
+ if let rustc_span::RealFileName::Remapped { local_path: _, virtual_name } =
+ old_name
+ {
+ if let Ok(rest) = virtual_name.strip_prefix(virtual_dir) {
+ let virtual_name = virtual_name.clone();
+
+ // The std library crates are in
+ // `$sysroot/lib/rustlib/src/rust/library`, whereas other crates
+ // may be in `$sysroot/lib/rustlib/src/rust/` directly. So we
+ // detect crates from the std libs and handle them specially.
+ const STD_LIBS: &[&str] = &[
+ "core",
+ "alloc",
+ "std",
+ "test",
+ "term",
+ "unwind",
+ "proc_macro",
+ "panic_abort",
+ "panic_unwind",
+ "profiler_builtins",
+ "rtstartup",
+ "rustc-std-workspace-core",
+ "rustc-std-workspace-alloc",
+ "rustc-std-workspace-std",
+ "backtrace",
+ ];
+ let is_std_lib = STD_LIBS.iter().any(|l| rest.starts_with(l));
+
+ let new_path = if is_std_lib {
+ real_dir.join("library").join(rest)
+ } else {
+ real_dir.join(rest)
+ };
+
+ debug!(
+ "try_to_translate_virtual_to_real: `{}` -> `{}`",
+ virtual_name.display(),
+ new_path.display(),
+ );
+ let new_name = rustc_span::RealFileName::Remapped {
+ local_path: Some(new_path),
+ virtual_name,
+ };
+ *old_name = new_name;
+ }
+ }
+ }
+ }
+ }
+ };
+
+ self.cdata.source_map_import_info.get_or_init(|| {
+ let external_source_map = self.root.source_map.decode(self);
+
+ external_source_map
+ .map(|source_file_to_import| {
+ // We can't reuse an existing SourceFile, so allocate a new one
+ // containing the information we need.
+ let rustc_span::SourceFile {
+ mut name,
+ src_hash,
+ start_pos,
+ end_pos,
+ lines,
+ multibyte_chars,
+ non_narrow_chars,
+ normalized_pos,
+ name_hash,
+ ..
+ } = source_file_to_import;
+
+ // If this file is under $sysroot/lib/rustlib/src/ but has not been remapped
+ // during rust bootstrapping by `remap-debuginfo = true`, and the user
+ // wish to simulate that behaviour by -Z simulate-remapped-rust-src-base,
+ // then we change `name` to a similar state as if the rust was bootstrapped
+ // with `remap-debuginfo = true`.
+ // This is useful for testing so that tests about the effects of
+ // `try_to_translate_virtual_to_real` don't have to worry about how the
+ // compiler is bootstrapped.
+ if let Some(virtual_dir) =
+ &sess.opts.unstable_opts.simulate_remapped_rust_src_base
+ {
+ if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
+ if let rustc_span::FileName::Real(ref mut old_name) = name {
+ if let rustc_span::RealFileName::LocalPath(local) = old_name {
+ if let Ok(rest) = local.strip_prefix(real_dir) {
+ *old_name = rustc_span::RealFileName::Remapped {
+ local_path: None,
+ virtual_name: virtual_dir.join(rest),
+ };
+ }
+ }
+ }
+ }
+ }
+
+ // If this file's path has been remapped to `/rustc/$hash`,
+ // we might be able to reverse that (also see comments above,
+ // on `try_to_translate_virtual_to_real`).
+ try_to_translate_virtual_to_real(&mut name);
+
+ let source_length = (end_pos - start_pos).to_usize();
+
+ let local_version = sess.source_map().new_imported_source_file(
+ name,
+ src_hash,
+ name_hash,
+ source_length,
+ self.cnum,
+ lines,
+ multibyte_chars,
+ non_narrow_chars,
+ normalized_pos,
+ start_pos,
+ end_pos,
+ );
+ debug!(
+ "CrateMetaData::imported_source_files alloc \
+ source_file {:?} original (start_pos {:?} end_pos {:?}) \
+ translated (start_pos {:?} end_pos {:?})",
+ local_version.name,
+ start_pos,
+ end_pos,
+ local_version.start_pos,
+ local_version.end_pos
+ );
+
+ ImportedSourceFile {
+ original_start_pos: start_pos,
+ original_end_pos: end_pos,
+ translated_source_file: local_version,
+ }
+ })
+ .collect()
+ })
+ }
+
+ fn get_generator_diagnostic_data(
+ self,
+ tcx: TyCtxt<'tcx>,
+ id: DefIndex,
+ ) -> Option<GeneratorDiagnosticData<'tcx>> {
+ self.root
+ .tables
+ .generator_diagnostic_data
+ .get(self, id)
+ .map(|param| param.decode((self, tcx)))
+ .map(|generator_data| GeneratorDiagnosticData {
+ generator_interior_types: generator_data.generator_interior_types,
+ hir_owner: generator_data.hir_owner,
+ nodes_types: generator_data.nodes_types,
+ adjustments: generator_data.adjustments,
+ })
+ }
+
+ fn get_may_have_doc_links(self, index: DefIndex) -> bool {
+ self.root.tables.may_have_doc_links.get(self, index).is_some()
+ }
+
+ fn get_is_intrinsic(self, index: DefIndex) -> bool {
+ self.root.tables.is_intrinsic.get(self, index).is_some()
+ }
+}
+
+impl CrateMetadata {
+ pub(crate) fn new(
+ sess: &Session,
+ cstore: &CStore,
+ blob: MetadataBlob,
+ root: CrateRoot,
+ raw_proc_macros: Option<&'static [ProcMacro]>,
+ cnum: CrateNum,
+ cnum_map: CrateNumMap,
+ dep_kind: CrateDepKind,
+ source: CrateSource,
+ private_dep: bool,
+ host_hash: Option<Svh>,
+ ) -> CrateMetadata {
+ let trait_impls = root
+ .impls
+ .decode((&blob, sess))
+ .map(|trait_impls| (trait_impls.trait_id, trait_impls.impls))
+ .collect();
+ let alloc_decoding_state =
+ AllocDecodingState::new(root.interpret_alloc_index.decode(&blob).collect());
+ let dependencies = Lock::new(cnum_map.iter().cloned().collect());
+
+ // Pre-decode the DefPathHash->DefIndex table. This is a cheap operation
+ // that does not copy any data. It just does some data verification.
+ let def_path_hash_map = root.def_path_hash_map.decode(&blob);
+
+ let mut cdata = CrateMetadata {
+ blob,
+ root,
+ trait_impls,
+ incoherent_impls: Default::default(),
+ raw_proc_macros,
+ source_map_import_info: OnceCell::new(),
+ def_path_hash_map,
+ expn_hash_map: Default::default(),
+ alloc_decoding_state,
+ cnum,
+ cnum_map,
+ dependencies,
+ dep_kind: Lock::new(dep_kind),
+ source: Lrc::new(source),
+ private_dep,
+ host_hash,
+ extern_crate: Lock::new(None),
+ hygiene_context: Default::default(),
+ def_key_cache: Default::default(),
+ def_path_hash_cache: Default::default(),
+ };
+
+ // Need `CrateMetadataRef` to decode `DefId`s in simplified types.
+ cdata.incoherent_impls = cdata
+ .root
+ .incoherent_impls
+ .decode(CrateMetadataRef { cdata: &cdata, cstore })
+ .map(|incoherent_impls| (incoherent_impls.self_ty, incoherent_impls.impls))
+ .collect();
+
+ cdata
+ }
+
+ pub(crate) fn dependencies(&self) -> LockGuard<'_, Vec<CrateNum>> {
+ self.dependencies.borrow()
+ }
+
+ pub(crate) fn add_dependency(&self, cnum: CrateNum) {
+ self.dependencies.borrow_mut().push(cnum);
+ }
+
+ pub(crate) fn update_extern_crate(&self, new_extern_crate: ExternCrate) -> bool {
+ let mut extern_crate = self.extern_crate.borrow_mut();
+ let update = Some(new_extern_crate.rank()) > extern_crate.as_ref().map(ExternCrate::rank);
+ if update {
+ *extern_crate = Some(new_extern_crate);
+ }
+ update
+ }
+
+ pub(crate) fn source(&self) -> &CrateSource {
+ &*self.source
+ }
+
+ pub(crate) fn dep_kind(&self) -> CrateDepKind {
+ *self.dep_kind.lock()
+ }
+
+ pub(crate) fn update_dep_kind(&self, f: impl FnOnce(CrateDepKind) -> CrateDepKind) {
+ self.dep_kind.with_lock(|dep_kind| *dep_kind = f(*dep_kind))
+ }
+
+ pub(crate) fn required_panic_strategy(&self) -> Option<PanicStrategy> {
+ self.root.required_panic_strategy
+ }
+
+ pub(crate) fn needs_panic_runtime(&self) -> bool {
+ self.root.needs_panic_runtime
+ }
+
+ pub(crate) fn is_panic_runtime(&self) -> bool {
+ self.root.panic_runtime
+ }
+
+ pub(crate) fn is_profiler_runtime(&self) -> bool {
+ self.root.profiler_runtime
+ }
+
+ pub(crate) fn needs_allocator(&self) -> bool {
+ self.root.needs_allocator
+ }
+
+ pub(crate) fn has_global_allocator(&self) -> bool {
+ self.root.has_global_allocator
+ }
+
+ pub(crate) fn has_default_lib_allocator(&self) -> bool {
+ self.root.has_default_lib_allocator
+ }
+
+ pub(crate) fn is_proc_macro_crate(&self) -> bool {
+ self.root.is_proc_macro_crate()
+ }
+
+ pub(crate) fn name(&self) -> Symbol {
+ self.root.name
+ }
+
+ pub(crate) fn stable_crate_id(&self) -> StableCrateId {
+ self.root.stable_crate_id
+ }
+
+ pub(crate) fn hash(&self) -> Svh {
+ self.root.hash
+ }
+
+ fn num_def_ids(&self) -> usize {
+ self.root.tables.def_keys.size()
+ }
+
+ fn local_def_id(&self, index: DefIndex) -> DefId {
+ DefId { krate: self.cnum, index }
+ }
+
+ // Translate a DefId from the current compilation environment to a DefId
+ // for an external crate.
+ fn reverse_translate_def_id(&self, did: DefId) -> Option<DefId> {
+ for (local, &global) in self.cnum_map.iter_enumerated() {
+ if global == did.krate {
+ return Some(DefId { krate: local, index: did.index });
+ }
+ }
+
+ None
+ }
+}
+
+// Cannot be implemented on 'ProcMacro', as libproc_macro
+// does not depend on librustc_ast
+fn macro_kind(raw: &ProcMacro) -> MacroKind {
+ match raw {
+ ProcMacro::CustomDerive { .. } => MacroKind::Derive,
+ ProcMacro::Attr { .. } => MacroKind::Attr,
+ ProcMacro::Bang { .. } => MacroKind::Bang,
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-12 15:12:42 +0000