Google Git Google Git
Sign in
rust/rust/a123594de1feec1732ed9251135bc42ccaaef8f3/./compiler/rustc_metadata/src/rmeta/decoder.rs
blob: f4d3380594c9f685638de7c874525d0fe39368ec [file]
// Decoding metadata from a single crate's metadata
use std::iter::TrustedLen;
use std::ops::{Deref, DerefMut};
use std::path::{Path, PathBuf};
use std::sync::{Arc, OnceLock};
use std::{io, mem};
pub(super) use cstore_impl::provide;
use rustc_ast as ast;
use rustc_crate_store::{CrateSource, ExternCrate};
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::fx::FxIndexMap;
use rustc_data_structures::owned_slice::OwnedSlice;
use rustc_data_structures::sync::Lock;
use rustc_data_structures::unhash::UnhashMap;
use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
use rustc_expand::proc_macro::{AttrProcMacro, BangProcMacro, DeriveProcMacro};
use rustc_hir::Safety;
use rustc_hir::attrs::CanonicalSymbols;
use rustc_hir::attrs::diagnostic_items::DiagnosticItems;
use rustc_hir::def::Res;
use rustc_hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE};
use rustc_hir::definitions::{DefPath, DefPathData};
use rustc_index::Idx;
use rustc_middle::middle::lib_features::LibFeatures;
use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
use rustc_middle::ty::codec::TyDecoder;
use rustc_middle::ty::{RestrictionKind, Visibility};
use rustc_middle::{bug, implement_ty_decoder};
use rustc_proc_macro::bridge::client::Client as ProcMacroClient;
use rustc_serialize::opaque::MemDecoder;
use rustc_serialize::{Decodable, Decoder};
use rustc_session::config::TargetModifier;
use rustc_session::config::mitigation_coverage::DeniedPartialMitigation;
use rustc_span::def_id::ModId;
use rustc_span::hygiene::HygieneDecodeContext;
use rustc_span::{
BlobDecoder, BytePos, ByteSymbol, DUMMY_SP, Pos, RemapPathScopeComponents, SpanData,
SpanDecoder, Symbol, SyntaxContext, kw,
};
use tracing::debug;
use crate::creader::CStore;
use crate::eii::EiiMapEncodedKeyValue;
use crate::rmeta::table::IsDefault;
use crate::rmeta::*;
mod cstore_impl;
/// A reference to the raw binary version of crate metadata.
/// This struct applies [`MemDecoder`]'s validation when constructed
/// so that later constructions are guaranteed to succeed.
pub(crate) struct MetadataBlob(OwnedSlice);
impl std::ops::Deref for MetadataBlob {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
&self.0[..]
}
}
impl MetadataBlob {
/// Runs the [`MemDecoder`] validation and if it passes, constructs a new [`MetadataBlob`].
pub(crate) fn new(slice: OwnedSlice) -> Result<Self, ()> {
if MemDecoder::new(&slice, 0).is_ok() { Ok(Self(slice)) } else { Err(()) }
}
/// Since this has passed the validation of [`MetadataBlob::new`], this returns bytes which are
/// known to pass the [`MemDecoder`] validation.
pub(crate) fn bytes(&self) -> &OwnedSlice {
&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>;
/// Target modifiers - abi or exploit mitigations options that may cause unsoundness when mixed or
/// partially enabled.
pub(crate) type TargetModifiers = Vec<TargetModifier>;
/// The set of mitigations that cannot be partially enabled (see
/// [RFC 3855](https://github.com/rust-lang/rfcs/pull/3855)), but are currently enabled for this
/// crate.
pub(crate) type DeniedPartialMitigations = Vec<DeniedPartialMitigation>;
pub(crate) struct CrateMetadata {
/// The primary crate data - binary metadata blob.
blob: MetadataBlob,
// --- Some data pre-decoded from the metadata blob, usually for performance ---
/// Data about the top-level items in a crate, as well as various crate-level metadata.
root: CrateRoot,
/// Trait impl data.
/// FIXME: Used only from queries and can use query cache,
/// so pre-decoding can probably be avoided.
trait_impls: FxIndexMap<(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: FxIndexMap<SimplifiedType, LazyArray<DefIndex>>,
/// Proc macro function pointers for this crate, if it's a proc macro crate.
raw_proc_macros: Option<&'static [ProcMacroClient]>,
/// Source maps for code from the crate.
source_map_import_info: Lock<Vec<Option<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: OnceLock<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>>,
// --- 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,
/// How to link (or not link) this crate to the currently compiled crate.
dep_kind: CrateDepKind,
/// Filesystem location of this crate.
source: Arc<CrateSource>,
/// Whether or not this crate should be consider a private dependency.
/// Used by the 'exported_private_dependencies' lint, and for determining
/// whether to emit suggestions that reference this crate.
private_dep: bool,
/// The hash for the host proc macro. Used to support `-Z dual-proc-macro`.
host_hash: Option<Svh>,
/// The crate was used non-speculatively.
used: bool,
/// Additional data used for decoding `HygieneData` (e.g. `SyntaxContext`
/// and `ExpnId`).
/// Note that we store a `HygieneDecodeContext` for each `CrateMetadata`. 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: Option<ExternCrate>,
}
/// Holds information about a rustc_span::SourceFile imported from another crate.
/// See `imported_source_file()` for more information.
#[derive(Clone)]
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: Arc<rustc_span::SourceFile>,
}
/// Decode context used when we just have a blob of metadata from which we have to decode a header
/// and [`CrateRoot`]. After that, [`MetadataDecodeContext`] can be used.
/// Most notably, [`BlobDecodeContext]` doesn't implement [`SpanDecoder`]
pub(super) struct BlobDecodeContext<'a> {
opaque: MemDecoder<'a>,
blob: &'a MetadataBlob,
lazy_state: LazyState,
}
/// This trait abstracts over decoders that can decode lazy values using [`LazyState`]:
///
/// - [`LazyValue`]
/// - [`LazyArray`]
/// - [`LazyTable`]
pub(super) trait LazyDecoder: BlobDecoder {
fn set_lazy_state(&mut self, state: LazyState);
fn get_lazy_state(&self) -> LazyState;
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, width: usize, len: usize) -> LazyTable<I, T> {
self.read_lazy_offset_then(|pos| LazyTable::from_position_and_encoded_size(pos, width, len))
}
#[inline]
fn read_lazy_offset_then<T>(&mut self, f: impl Fn(NonZero<usize>) -> T) -> T {
let distance = self.read_usize();
let position = match self.get_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 = NonZero::new(position).unwrap();
self.set_lazy_state(LazyState::Previous(position));
f(position)
}
}
impl<'a> LazyDecoder for BlobDecodeContext<'a> {
fn set_lazy_state(&mut self, state: LazyState) {
self.lazy_state = state;
}
fn get_lazy_state(&self) -> LazyState {
self.lazy_state
}
}
/// This is the decode context used when crate metadata was already read.
/// Decoding of some types, like `Span` require some information to already been read.
/// Can be constructed from a [`TyCtxt`] and [`CrateMetadata`] (see impls of the [`MetaDecoder`]
/// trait).
pub(super) struct MetadataDecodeContext<'a, 'tcx> {
blob_decoder: BlobDecodeContext<'a>,
cdata: &'a CrateMetadata,
tcx: TyCtxt<'tcx>,
// Used for decoding interpret::AllocIds in a cached & thread-safe manner.
alloc_decoding_session: AllocDecodingSession<'a>,
}
impl<'a, 'tcx> LazyDecoder for MetadataDecodeContext<'a, 'tcx> {
fn set_lazy_state(&mut self, state: LazyState) {
self.lazy_state = state;
}
fn get_lazy_state(&self) -> LazyState {
self.lazy_state
}
}
impl<'a, 'tcx> DerefMut for MetadataDecodeContext<'a, 'tcx> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.blob_decoder
}
}
impl<'a, 'tcx> Deref for MetadataDecodeContext<'a, 'tcx> {
type Target = BlobDecodeContext<'a>;
fn deref(&self) -> &Self::Target {
&self.blob_decoder
}
}
pub(super) trait MetaBlob<'a>: Copy {
fn blob(&self) -> &'a MetadataBlob;
}
pub(super) trait MetaDecoder: Copy {
type Context: BlobDecoder + LazyDecoder;
fn decoder(self, pos: usize) -> Self::Context;
}
impl<'a> MetaBlob<'a> for &'a MetadataBlob {
fn blob(&self) -> &'a MetadataBlob {
self
}
}
impl<'a> MetaDecoder for &'a MetadataBlob {
type Context = BlobDecodeContext<'a>;
fn decoder(self, pos: usize) -> Self::Context {
BlobDecodeContext {
// FIXME: This unwrap should never panic because we check that it won't when creating
// `MetadataBlob`. Ideally we'd just have a `MetadataDecoder` and hand out subslices of
// it as we do elsewhere in the compiler using `MetadataDecoder::split_at`. But we own
// the data for the decoder so holding onto the `MemDecoder` too would make us a
// self-referential struct which is downright goofy because `MetadataBlob` is already
// self-referential. Probably `MemDecoder` should contain an `OwnedSlice`, but that
// demands a significant refactoring due to our crate graph.
opaque: MemDecoder::new(self, pos).unwrap(),
lazy_state: LazyState::NoNode,
blob: self.blob(),
}
}
}
impl<'a> MetaBlob<'a> for &'a CrateMetadata {
fn blob(&self) -> &'a MetadataBlob {
&self.blob
}
}
impl<'a, 'tcx> MetaDecoder for (&'a CrateMetadata, TyCtxt<'tcx>) {
type Context = MetadataDecodeContext<'a, 'tcx>;
fn decoder(self, pos: usize) -> MetadataDecodeContext<'a, 'tcx> {
MetadataDecodeContext {
blob_decoder: self.0.blob().decoder(pos),
cdata: self.0,
tcx: self.1,
alloc_decoding_session: self.0.alloc_decoding_state.new_decoding_session(),
}
}
}
impl<T: ParameterizedOverTcx> LazyValue<T> {
#[inline]
fn decode<'tcx, M: MetaDecoder>(self, metadata: M) -> T::Value<'tcx>
where
T::Value<'tcx>: Decodable<M::Context>,
{
let mut dcx = metadata.decoder(self.position.get());
dcx.set_lazy_state(LazyState::NodeStart(self.position));
T::Value::decode(&mut dcx)
}
}
struct DecodeIterator<T, D> {
elem_counter: std::ops::Range<usize>,
dcx: D,
_phantom: PhantomData<fn() -> T>,
}
impl<D: Decoder, T: Decodable<D>> Iterator for DecodeIterator<T, D> {
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<D: Decoder, T: Decodable<D>> ExactSizeIterator for DecodeIterator<T, D> {
fn len(&self) -> usize {
self.elem_counter.len()
}
}
unsafe impl<D: Decoder, T: Decodable<D>> TrustedLen for DecodeIterator<T, D> {}
impl<T: ParameterizedOverTcx> LazyArray<T> {
#[inline]
fn decode<'tcx, M: MetaDecoder>(self, metadata: M) -> DecodeIterator<T::Value<'tcx>, M::Context>
where
T::Value<'tcx>: Decodable<M::Context>,
{
let mut dcx = metadata.decoder(self.position.get());
dcx.set_lazy_state(LazyState::NodeStart(self.position));
DecodeIterator { elem_counter: (0..self.num_elems), dcx, _phantom: PhantomData }
}
}
impl<'a, 'tcx> MetadataDecodeContext<'a, 'tcx> {
#[inline]
fn map_encoded_cnum_to_current(&self, cnum: CrateNum) -> CrateNum {
self.cdata.map_encoded_cnum_to_current(cnum)
}
}
impl<'a> BlobDecodeContext<'a> {
#[inline]
pub(crate) fn blob(&self) -> &'a MetadataBlob {
self.blob
}
fn decode_symbol_or_byte_symbol<S>(
&mut self,
new_from_index: impl Fn(u32) -> S,
read_and_intern_str_or_byte_str_this: impl Fn(&mut Self) -> S,
read_and_intern_str_or_byte_str_opaque: impl Fn(&mut MemDecoder<'a>) -> S,
) -> S {
let tag = self.read_u8();
match tag {
SYMBOL_STR => read_and_intern_str_or_byte_str_this(self),
SYMBOL_OFFSET => {
// read str offset
let pos = self.read_usize();
// move to str offset and read
self.opaque.with_position(pos, |d| read_and_intern_str_or_byte_str_opaque(d))
}
SYMBOL_PREDEFINED => new_from_index(self.read_u32()),
_ => unreachable!(),
}
}
}
impl<'a, 'tcx> TyDecoder<'tcx> for MetadataDecodeContext<'a, 'tcx> {
const CLEAR_CROSS_CRATE: bool = true;
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 = self.blob_decoder.opaque.split_at(pos);
let old_opaque = mem::replace(&mut self.blob_decoder.opaque, new_opaque);
let old_state = mem::replace(&mut self.blob_decoder.lazy_state, LazyState::NoNode);
let r = f(self);
self.blob_decoder.opaque = old_opaque;
self.blob_decoder.lazy_state = old_state;
r
}
fn decode_alloc_id(&mut self) -> rustc_middle::mir::interpret::AllocId {
let ads = self.alloc_decoding_session;
ads.decode_alloc_id(self)
}
}
impl<'a, 'tcx> rustc_middle::ty::InternerDecoder for MetadataDecodeContext<'a, 'tcx> {
type Interner = TyCtxt<'tcx>;
#[inline]
fn interner(&self) -> TyCtxt<'tcx> {
self.tcx
}
}
impl<'a, 'tcx> Decodable<MetadataDecodeContext<'a, 'tcx>> for ExpnIndex {
#[inline]
fn decode(d: &mut MetadataDecodeContext<'a, 'tcx>) -> ExpnIndex {
ExpnIndex::from_u32(d.read_u32())
}
}
impl<'a, 'tcx> SpanDecoder for MetadataDecodeContext<'a, 'tcx> {
fn decode_attr_id(&mut self) -> rustc_span::AttrId {
self.tcx.sess.psess.attr_id_generator.mk_attr_id()
}
fn decode_crate_num(&mut self) -> CrateNum {
let cnum = CrateNum::from_u32(self.read_u32());
self.map_encoded_cnum_to_current(cnum)
}
fn decode_def_id(&mut self) -> DefId {
DefId { krate: Decodable::decode(self), index: Decodable::decode(self) }
}
fn decode_syntax_context(&mut self) -> SyntaxContext {
let cdata = self.cdata;
let tcx = self.tcx;
let cname = cdata.root.name();
rustc_span::hygiene::decode_syntax_context(self, &cdata.hygiene_context, |_, id| {
debug!("SpecializedDecoder<SyntaxContext>: decoding {}", id);
cdata
.root
.syntax_contexts
.get(cdata, id)
.unwrap_or_else(|| panic!("Missing SyntaxContext {id:?} for crate {cname:?}"))
.decode((cdata, tcx))
})
}
fn decode_expn_id(&mut self) -> ExpnId {
let tcx = self.tcx;
let cnum = CrateNum::decode(self);
let index = u32::decode(self);
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 cstore;
let cdata = if cnum == self.cdata.cnum {
self.cdata
} else {
cstore = CStore::from_tcx(tcx);
cstore.get_crate_data(cnum)
};
let expn_data = cdata.root.expn_data.get(cdata, index).unwrap().decode((cdata, tcx));
let expn_hash = cdata.root.expn_hashes.get(cdata, index).unwrap().decode((cdata, tcx));
(expn_data, expn_hash)
});
expn_id
}
fn decode_span(&mut self) -> Span {
let start = self.position();
let tag = SpanTag(self.peek_byte());
let data = if tag.kind() == SpanKind::Indirect {
// Skip past the tag we just peek'd.
self.read_u8();
// indirect tag lengths are safe to access, since they're (0, 8)
let bytes_needed = tag.length().unwrap().0 as usize;
let mut total = [0u8; usize::BITS as usize / 8];
total[..bytes_needed].copy_from_slice(self.read_raw_bytes(bytes_needed));
let offset_or_position = usize::from_le_bytes(total);
let position = if tag.is_relative_offset() {
start - offset_or_position
} else {
offset_or_position
};
self.with_position(position, SpanData::decode)
} else {
SpanData::decode(self)
};
data.span()
}
}
impl<'a, 'tcx> BlobDecoder for MetadataDecodeContext<'a, 'tcx> {
fn decode_def_index(&mut self) -> DefIndex {
self.blob_decoder.decode_def_index()
}
fn decode_symbol(&mut self) -> Symbol {
self.blob_decoder.decode_symbol()
}
fn decode_byte_symbol(&mut self) -> ByteSymbol {
self.blob_decoder.decode_byte_symbol()
}
}
impl<'a> BlobDecoder for BlobDecodeContext<'a> {
fn decode_def_index(&mut self) -> DefIndex {
DefIndex::from_u32(self.read_u32())
}
fn decode_symbol(&mut self) -> Symbol {
self.decode_symbol_or_byte_symbol(
Symbol::new,
|this| Symbol::intern(this.read_str()),
|opaque| Symbol::intern(opaque.read_str()),
)
}
fn decode_byte_symbol(&mut self) -> ByteSymbol {
self.decode_symbol_or_byte_symbol(
ByteSymbol::new,
|this| ByteSymbol::intern(this.read_byte_str()),
|opaque| ByteSymbol::intern(opaque.read_byte_str()),
)
}
}
impl<'a, 'tcx> Decodable<MetadataDecodeContext<'a, 'tcx>> for SpanData {
fn decode(decoder: &mut MetadataDecodeContext<'a, 'tcx>) -> SpanData {
let tag = SpanTag::decode(decoder);
let ctxt = tag.context().unwrap_or_else(|| SyntaxContext::decode(decoder));
if tag.kind() == SpanKind::Partial {
return DUMMY_SP.with_ctxt(ctxt).data();
}
debug_assert!(tag.kind() == SpanKind::Local || tag.kind() == SpanKind::Foreign);
let lo = BytePos::decode(decoder);
let len = tag.length().unwrap_or_else(|| BytePos::decode(decoder));
let hi = lo + len;
let tcx = decoder.tcx;
// Index of the file in the corresponding crate's list of encoded files.
let metadata_index = u32::decode(decoder);
// 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_file` for the proper crate, and binary search
// through the returned slice using our span.
let source_file = if tag.kind() == SpanKind::Local {
decoder.cdata.imported_source_file(tcx, metadata_index)
} 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.header.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
);
let cstore = CStore::from_tcx(tcx);
let foreign_cdata = cstore.get_crate_data(cnum);
foreign_cdata.imported_source_file(tcx, metadata_index)
};
// Make sure our span is well-formed.
debug_assert!(
lo + source_file.original_start_pos <= source_file.original_end_pos,
"Malformed encoded span: 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 <= source_file.original_end_pos,
"Malformed encoded span: 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;
let hi = hi + source_file.translated_source_file.start_pos;
// Do not try to decode parent for foreign spans (it wasn't encoded in the first place).
SpanData { lo, hi, ctxt, parent: None }
}
}
impl<'a, 'tcx> Decodable<MetadataDecodeContext<'a, 'tcx>> for &'tcx [(ty::Clause<'tcx>, Span)] {
fn decode(d: &mut MetadataDecodeContext<'a, 'tcx>) -> Self {
ty::codec::RefDecodable::decode(d)
}
}
impl<D: LazyDecoder, T> Decodable<D> for LazyValue<T> {
fn decode(decoder: &mut D) -> Self {
decoder.read_lazy()
}
}
impl<D: LazyDecoder, T> Decodable<D> for LazyArray<T> {
#[inline]
fn decode(decoder: &mut D) -> Self {
let len = decoder.read_usize();
if len == 0 { LazyArray::default() } else { decoder.read_lazy_array(len) }
}
}
impl<I: Idx, D: LazyDecoder, T> Decodable<D> for LazyTable<I, T> {
fn decode(decoder: &mut D) -> Self {
let width = decoder.read_usize();
let len = decoder.read_usize();
decoder.read_lazy_table(width, len)
}
}
mod meta {
use super::*;
implement_ty_decoder!(MetadataDecodeContext<'a, 'tcx>);
}
mod blob {
use super::*;
implement_ty_decoder!(BlobDecodeContext<'a>);
}
impl MetadataBlob {
pub(crate) fn check_compatibility(
&self,
cfg_version: &'static str,
) -> Result<(), Option<String>> {
if !self.starts_with(METADATA_HEADER) {
if self.starts_with(b"rust") {
return Err(Some("<unknown rustc version>".to_owned()));
}
return Err(None);
}
let found_version =
LazyValue::<String>::from_position(NonZero::new(METADATA_HEADER.len() + 8).unwrap())
.decode(self);
if rustc_version(cfg_version) != found_version {
return Err(Some(found_version));
}
Ok(())
}
fn root_pos(&self) -> NonZero<usize> {
let offset = METADATA_HEADER.len();
let pos_bytes = self[offset..][..8].try_into().unwrap();
let pos = u64::from_le_bytes(pos_bytes);
NonZero::new(pos as usize).unwrap()
}
pub(crate) fn get_header(&self) -> CrateHeader {
let pos = self.root_pos();
LazyValue::<CrateHeader>::from_position(pos).decode(self)
}
pub(crate) fn get_root(&self) -> CrateRoot {
let pos = self.root_pos();
LazyValue::<CrateRoot>::from_position(pos).decode(self)
}
pub(crate) fn list_crate_metadata(
&self,
out: &mut dyn io::Write,
ls_kinds: &[String],
) -> io::Result<()> {
let root = self.get_root();
let all_ls_kinds = vec![
"root".to_owned(),
"lang_items".to_owned(),
"features".to_owned(),
"items".to_owned(),
"target_modifiers".to_owned(),
];
let ls_kinds = if ls_kinds.contains(&"all".to_owned()) { &all_ls_kinds } else { ls_kinds };
for kind in ls_kinds {
match &**kind {
"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, "triple {}", root.header.triple.tuple())?;
writeln!(out, "edition {}", root.edition)?;
writeln!(out, "symbol_mangling_version {:?}", root.symbol_mangling_version)?;
writeln!(
out,
"required_panic_strategy {:?} panic_in_drop_strategy {:?}",
root.required_panic_strategy, root.panic_in_drop_strategy
)?;
writeln!(
out,
"has_global_allocator {} has_alloc_error_handler {} has_panic_handler {} has_default_lib_allocator {}",
root.has_global_allocator,
root.has_alloc_error_handler,
root.has_panic_handler,
root.has_default_lib_allocator
)?;
writeln!(
out,
"compiler_builtins {} needs_allocator {} needs_panic_runtime {} no_builtins {} panic_runtime {} profiler_runtime {}",
root.compiler_builtins,
root.needs_allocator,
root.needs_panic_runtime,
root.no_builtins,
root.panic_runtime,
root.profiler_runtime
)?;
writeln!(out, "=External Dependencies=")?;
let dylib_dependency_formats =
root.dylib_dependency_formats.decode(self).collect::<Vec<_>>();
for (i, dep) in root.crate_deps.decode(self).enumerate() {
let CrateDep { name, extra_filename, hash, host_hash, kind, is_private } =
dep;
let number = i + 1;
writeln!(
out,
"{number} {name}{extra_filename} hash {hash} host_hash {host_hash:?} kind {kind:?} {privacy}{linkage}",
privacy = if is_private { "private" } else { "public" },
linkage = if dylib_dependency_formats.is_empty() {
String::new()
} else {
format!(" linkage {:?}", dylib_dependency_formats[i])
}
)?;
}
write!(out, "\n")?;
}
"lang_items" => {
writeln!(out, "=Lang items=")?;
for (id, lang_item) in root.lang_items.decode(self) {
writeln!(
out,
"{} = crate{}",
lang_item.name(),
DefPath::make(LOCAL_CRATE, id, |parent| root
.tables
.def_keys
.get(self, parent)
.unwrap()
.decode(self))
.to_string_no_crate_verbose()
)?;
}
for lang_item in root.lang_items_missing.decode(self) {
writeln!(out, "{} = <missing>", lang_item.name())?;
}
write!(out, "\n")?;
}
"features" => {
writeln!(out, "=Lib features=")?;
for (feature, since) in root.lib_features.decode(self) {
writeln!(
out,
"{}{}",
feature,
if let FeatureStability::AcceptedSince(since) = since {
format!(" since {since}")
} else {
String::new()
}
)?;
}
write!(out, "\n")?;
}
"items" => {
writeln!(out, "=Items=")?;
fn print_item(
blob: &MetadataBlob,
out: &mut dyn io::Write,
item: DefIndex,
indent: usize,
) -> io::Result<()> {
let root = blob.get_root();
let def_kind = root.tables.def_kind.get(blob, item).unwrap();
let def_key = root.tables.def_keys.get(blob, item).unwrap().decode(blob);
#[allow(rustc::symbol_intern_string_literal)]
let def_name = if item == CRATE_DEF_INDEX {
kw::Crate
} else {
def_key
.disambiguated_data
.data
.get_opt_name()
.unwrap_or_else(|| Symbol::intern("???"))
};
let visibility =
root.tables.visibility.get(blob, item).unwrap().decode(blob).map_id(
|index| {
format!(
"crate{}",
DefPath::make(LOCAL_CRATE, index, |parent| root
.tables
.def_keys
.get(blob, parent)
.unwrap()
.decode(blob))
.to_string_no_crate_verbose()
)
},
);
write!(
out,
"{nil: <indent$}{:?} {:?} {} {{",
visibility,
def_kind,
def_name,
nil = "",
)?;
if let Some(children) =
root.tables.module_children_non_reexports.get(blob, item)
{
write!(out, "\n")?;
for child in children.decode(blob) {
print_item(blob, out, child, indent + 4)?;
}
writeln!(out, "{nil: <indent$}}}", nil = "")?;
} else {
writeln!(out, "}}")?;
}
Ok(())
}
print_item(self, out, CRATE_DEF_INDEX, 0)?;
write!(out, "\n")?;
}
"target_modifiers" => {
writeln!(out, "=Target modifiers=")?;
for modifier in root.decode_target_modifiers(self) {
let extended = modifier.extend();
writeln!(
out,
"-{}{}={} [{}]",
extended.prefix,
extended.name,
modifier.value_name,
extended.tech_value,
)?;
}
}
_ => {
writeln!(
out,
"unknown -Zls kind. allowed values are: all, root, lang_items, features, items, \
target_modifiers"
)?;
}
}
}
Ok(())
}
pub(crate) fn get_proc_macro_info(&self) -> Vec<ProcMacroKind> {
self.get_root()
.proc_macro_data
.unwrap()
.macros
.decode(self)
.map(|(_id, kind)| kind.decode(self))
.collect::<Vec<_>>()
}
}
impl CrateRoot {
pub(crate) fn is_proc_macro_crate(&self) -> bool {
self.proc_macro_data.is_some()
}
pub(crate) fn name(&self) -> Symbol {
self.header.name
}
pub(crate) fn hash(&self) -> Svh {
self.header.hash
}
pub(crate) fn stable_crate_id(&self) -> StableCrateId {
self.stable_crate_id
}
pub(crate) fn decode_crate_deps<'a>(
&self,
metadata: &'a MetadataBlob,
) -> impl ExactSizeIterator<Item = CrateDep> {
self.crate_deps.decode(metadata)
}
pub(crate) fn decode_target_modifiers<'a>(
&self,
metadata: &'a MetadataBlob,
) -> impl ExactSizeIterator<Item = TargetModifier> {
self.target_modifiers.decode(metadata)
}
pub(crate) fn decode_denied_partial_mitigations<'a>(
&self,
metadata: &'a MetadataBlob,
) -> impl ExactSizeIterator<Item = DeniedPartialMitigation> {
self.denied_partial_mitigations.decode(metadata)
}
}
impl CrateMetadata {
fn missing(&self, descr: &str, id: DefIndex) -> ! {
bug!("missing `{descr}` for {:?}", self.local_def_id(id))
}
fn raw_proc_macro(&self, tcx: TyCtxt<'_>, id: DefIndex) -> (ProcMacroClient, ProcMacroKind) {
// DefIndex's in root.proc_macro_data have a one-to-one correspondence
// with items in 'raw_proc_macros'.
let (pos, (_id, kind)) = self
.root
.proc_macro_data
.as_ref()
.unwrap()
.macros
.decode((self, tcx))
.enumerate()
.find(|(_pos, (i, _))| *i == id)
.unwrap();
(self.raw_proc_macros.unwrap()[pos], kind.decode((self, tcx)))
}
fn opt_item_name(&self, item_index: DefIndex) -> Option<Symbol> {
let def_key = self.def_key(item_index);
def_key.disambiguated_data.data.get_opt_name().or_else(|| {
if def_key.disambiguated_data.data == DefPathData::Ctor {
let parent_index = def_key.parent.expect("no parent for a constructor");
self.def_key(parent_index).disambiguated_data.data.get_opt_name()
} else {
None
}
})
}
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, tcx: TyCtxt<'_>, item_index: DefIndex) -> Option<Ident> {
let name = self.opt_item_name(item_index)?;
let span = self
.root
.tables
.def_ident_span
.get(self, item_index)
.unwrap_or_else(|| self.missing("def_ident_span", item_index))
.decode((self, tcx));
Some(Ident::new(name, span))
}
fn item_ident(&self, tcx: TyCtxt<'_>, item_index: DefIndex) -> Ident {
self.opt_item_ident(tcx, item_index).expect("no encoded ident for item")
}
#[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 def_kind(&self, item_id: DefIndex) -> DefKind {
self.root
.tables
.def_kind
.get(self, item_id)
.unwrap_or_else(|| self.missing("def_kind", item_id))
}
fn get_span(&self, tcx: TyCtxt<'_>, index: DefIndex) -> Span {
self.root
.tables
.def_span
.get(self, index)
.unwrap_or_else(|| self.missing("def_span", index))
.decode((self, tcx))
}
fn load_proc_macro<'tcx>(&self, tcx: TyCtxt<'tcx>, id: DefIndex) -> SyntaxExtension {
let (name, kind, helper_attrs) = match self.raw_proc_macro(tcx, id) {
(client, ProcMacroKind::CustomDerive { trait_name, attributes }) => {
let helper_attrs =
attributes.into_iter().map(|attr| Symbol::intern(&attr)).collect();
(
trait_name,
SyntaxExtensionKind::Derive(Arc::new(DeriveProcMacro { client })),
helper_attrs,
)
}
(client, ProcMacroKind::Attr { name }) => {
(name, SyntaxExtensionKind::Attr(Arc::new(AttrProcMacro { client })), Vec::new())
}
(client, ProcMacroKind::Bang { name }) => {
(name, SyntaxExtensionKind::Bang(Arc::new(BangProcMacro { client })), Vec::new())
}
};
let sess = tcx.sess;
let attrs: Vec<_> = self.get_item_attrs(tcx, id).collect();
SyntaxExtension::new(
sess,
kind,
self.get_span(tcx, id),
helper_attrs,
self.root.edition,
Symbol::intern(&name),
&attrs,
false,
)
}
fn get_variant(
&self,
tcx: TyCtxt<'_>,
kind: DefKind,
index: DefIndex,
parent_did: DefId,
) -> (VariantIdx, ty::VariantDef) {
let adt_kind = match kind {
DefKind::Variant => ty::AdtKind::Enum,
DefKind::Struct => ty::AdtKind::Struct,
DefKind::Union => ty::AdtKind::Union,
_ => bug!(),
};
let data = self.root.tables.variant_data.get(self, index).unwrap().decode((self, tcx));
let variant_did =
if adt_kind == ty::AdtKind::Enum { Some(self.local_def_id(index)) } else { None };
let ctor = data.ctor.map(|(kind, index)| (kind, self.local_def_id(index)));
(
data.idx,
ty::VariantDef::new(
self.item_name(index),
variant_did,
ctor,
data.discr,
self.get_associated_item_or_field_def_ids(tcx, index)
.map(|did| ty::FieldDef {
did,
name: self.item_name(did.index),
vis: self.get_visibility(tcx, did.index),
mut_restriction: self.get_mut_restriction(tcx, did.index),
safety: self.get_safety(did.index),
value: self.get_default_field(tcx, did.index),
})
.collect(),
parent_did,
None,
data.is_non_exhaustive,
),
)
}
fn get_adt_def<'tcx>(&self, tcx: TyCtxt<'tcx>, item_id: DefIndex) -> ty::AdtDef<'tcx> {
let kind = self.def_kind(item_id);
let did = self.local_def_id(item_id);
let adt_kind = match kind {
DefKind::Enum => ty::AdtKind::Enum,
DefKind::Struct => ty::AdtKind::Struct,
DefKind::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, tcx));
let mut variants: Vec<_> = if let ty::AdtKind::Enum = adt_kind {
self.root
.tables
.module_children_non_reexports
.get(self, item_id)
.expect("variants are not encoded for an enum")
.decode((self, tcx))
.filter_map(|index| {
let kind = self.def_kind(index);
match kind {
DefKind::Ctor(..) => None,
_ => Some(self.get_variant(tcx, kind, index, did)),
}
})
.collect()
} else {
std::iter::once(self.get_variant(tcx, kind, item_id, did)).collect()
};
variants.sort_by_key(|(idx, _)| *idx);
tcx.mk_adt_def(
did,
adt_kind,
variants.into_iter().map(|(_, variant)| variant).collect(),
repr,
)
}
fn get_visibility(&self, tcx: TyCtxt<'_>, id: DefIndex) -> Visibility<ModId> {
self.root
.tables
.visibility
.get(self, id)
.unwrap_or_else(|| self.missing("visibility", id))
.decode((self, tcx))
.map_id(|index| ModId::new_unchecked(self.local_def_id(index)))
}
fn get_mut_restriction(&self, tcx: TyCtxt<'_>, id: DefIndex) -> RestrictionKind {
self.root
.tables
.mut_restriction
.get(self, id)
.unwrap_or_else(|| self.missing("mut_restriction", id))
.decode((self, tcx))
}
fn get_safety(&self, id: DefIndex) -> Safety {
self.root.tables.safety.get(self, id)
}
fn get_default_field(&self, tcx: TyCtxt<'_>, id: DefIndex) -> Option<DefId> {
self.root.tables.default_fields.get(self, id).map(|d| d.decode((self, tcx)))
}
fn get_expn_that_defined(&self, tcx: TyCtxt<'_>, id: DefIndex) -> ExpnId {
self.root
.tables
.expn_that_defined
.get(self, id)
.unwrap_or_else(|| self.missing("expn_that_defined", id))
.decode((self, tcx))
}
fn get_debugger_visualizers(&self, tcx: TyCtxt<'_>) -> Vec<DebuggerVisualizerFile> {
self.root.debugger_visualizers.decode((self, tcx)).collect::<Vec<_>>()
}
/// Iterates over all the stability attributes in the given crate.
fn get_lib_features(&self, tcx: TyCtxt<'_>) -> LibFeatures {
LibFeatures {
stability: self
.root
.lib_features
.decode((self, tcx))
.map(|(sym, stab)| (sym, (stab, DUMMY_SP)))
.collect(),
}
}
/// 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<'tcx>(&self, tcx: TyCtxt<'tcx>) -> &'tcx [(Symbol, Symbol)] {
tcx.arena.alloc_from_iter(self.root.stability_implications.decode((self, tcx)))
}
/// Iterates over the lang items in the given crate.
fn get_lang_items<'tcx>(&self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, LangItem)] {
tcx.arena.alloc_from_iter(
self.root
.lang_items
.decode((self, tcx))
.map(move |(def_index, index)| (self.local_def_id(def_index), index)),
)
}
fn get_stripped_cfg_items<'tcx>(
&self,
tcx: TyCtxt<'tcx>,
cnum: CrateNum,
) -> &'tcx [StrippedCfgItem] {
let item_names = self
.root
.stripped_cfg_items
.decode((self, tcx))
.map(|item| item.map_scope_id(|index| DefId { krate: cnum, index }));
tcx.arena.alloc_from_iter(item_names)
}
/// Iterates over the diagnostic items in the given crate.
fn get_diagnostic_items(&self, tcx: TyCtxt<'_>) -> DiagnosticItems {
let mut id_to_name = DefIdMap::default();
let name_to_id = self
.root
.diagnostic_items
.decode((self, tcx))
.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 the canonical_symbols in the given crate.
fn get_canonical_symbols(&self, tcx: TyCtxt<'_>) -> CanonicalSymbols {
let mut canonical_symbols = CanonicalSymbols::new();
for (name, def_index) in self.root.canonical_symbols.decode((self, tcx)) {
let id = self.local_def_id(def_index);
let _ = canonical_symbols.set(name, id);
}
canonical_symbols
}
fn get_mod_child(&self, tcx: TyCtxt<'_>, id: DefIndex) -> ModChild {
let ident = self.item_ident(tcx, id);
let res = Res::Def(self.def_kind(id), self.local_def_id(id));
let vis = self.get_visibility(tcx, id);
ModChild { ident, res, vis, reexport_chain: Default::default() }
}
/// 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.
///
/// # Panics
///
/// May panic if the provided `id` does not refer to a module.
fn get_module_children(&self, tcx: TyCtxt<'_>, id: DefIndex) -> impl Iterator<Item = ModChild> {
gen move {
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 (child_index, _) in data.macros.decode((self, tcx)) {
yield self.get_mod_child(tcx, child_index);
}
}
} else {
// Iterate over all children.
let non_reexports = self.root.tables.module_children_non_reexports.get(self, id);
let non_reexports =
non_reexports.expect("provided `DefIndex` must refer to a module-like item");
for child_index in non_reexports.decode((self, tcx)) {
yield self.get_mod_child(tcx, child_index);
}
let reexports = self.root.tables.module_children_reexports.get(self, id);
if !reexports.is_default() {
for reexport in reexports.decode((self, tcx)) {
yield reexport;
}
}
}
}
}
fn get_ambig_module_children(
&self,
tcx: TyCtxt<'_>,
id: DefIndex,
) -> impl Iterator<Item = AmbigModChild> {
gen move {
let children = self.root.tables.ambig_module_children.get(self, id);
if !children.is_default() {
for child in children.decode((self, tcx)) {
yield child;
}
}
}
}
fn is_item_mir_available(&self, id: DefIndex) -> bool {
self.root.tables.optimized_mir.get(self, id).is_some()
}
fn get_fn_has_self_parameter(&self, tcx: TyCtxt<'_>, id: DefIndex) -> bool {
self.root
.tables
.fn_arg_idents
.get(self, id)
.expect("argument names not encoded for a function")
.decode((self, tcx))
.nth(0)
.is_some_and(|ident| matches!(ident, Some(Ident { name: kw::SelfLower, .. })))
}
fn get_associated_item_or_field_def_ids(
&self,
tcx: TyCtxt<'_>,
id: DefIndex,
) -> impl Iterator<Item = DefId> {
self.root
.tables
.associated_item_or_field_def_ids
.get(self, id)
.unwrap_or_else(|| self.missing("associated_item_or_field_def_ids", id))
.decode((self, tcx))
.map(move |child_index| self.local_def_id(child_index))
}
fn get_associated_item(&self, tcx: TyCtxt<'_>, id: DefIndex) -> ty::AssocItem {
let kind = match self.def_kind(id) {
DefKind::AssocConst { is_type_const } => {
ty::AssocKind::Const { name: self.item_name(id), is_type_const }
}
DefKind::AssocFn => ty::AssocKind::Fn {
name: self.item_name(id),
has_self: self.get_fn_has_self_parameter(tcx, id),
},
DefKind::AssocTy => {
let data = if let Some(rpitit_info) = self.root.tables.opt_rpitit_info.get(self, id)
{
ty::AssocTypeData::Rpitit(rpitit_info.decode((self, tcx)))
} else {
ty::AssocTypeData::Normal(self.item_name(id))
};
ty::AssocKind::Type { data }
}
_ => bug!("cannot get associated-item of `{:?}`", self.def_key(id)),
};
let container = self.root.tables.assoc_container.get(self, id).unwrap().decode((self, tcx));
ty::AssocItem { kind, def_id: self.local_def_id(id), container }
}
fn get_ctor(&self, tcx: TyCtxt<'_>, node_id: DefIndex) -> Option<(CtorKind, DefId)> {
match self.def_kind(node_id) {
DefKind::Struct | DefKind::Variant => {
let vdata =
self.root.tables.variant_data.get(self, node_id).unwrap().decode((self, tcx));
vdata.ctor.map(|(kind, index)| (kind, self.local_def_id(index)))
}
_ => None,
}
}
fn get_item_attrs(
&self,
tcx: TyCtxt<'_>,
id: DefIndex,
) -> impl Iterator<Item = hir::Attribute> {
self.root
.tables
.attributes
.get(self, id)
.unwrap_or_else(|| {
let def_key = self.def_key(id);
match def_key.disambiguated_data.data {
DefPathData::Ctor => {
// 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.
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")
}
DefPathData::SyntheticCoroutineBody => {
// SyntheticCoroutineBodies cannot have attributes
LazyArray::default()
}
_ => panic!("Definition key {def_key:?} of type `{:?}` did not have any attributes stored", def_key.disambiguated_data.data)
}
})
.decode((self, tcx))
}
fn get_inherent_implementations_for_type<'tcx>(
&self,
tcx: TyCtxt<'tcx>,
id: DefIndex,
) -> &'tcx [DefId] {
tcx.arena.alloc_from_iter(
self.root
.tables
.inherent_impls
.get(self, id)
.decode((self, tcx))
.map(|index| self.local_def_id(index)),
)
}
/// Decodes all traits in the crate (for rustdoc and rustc diagnostics).
fn get_traits(&self, tcx: TyCtxt<'_>) -> impl Iterator<Item = DefId> {
self.root.traits.decode((self, tcx)).map(move |index| self.local_def_id(index))
}
/// Decodes all trait impls in the crate (for rustdoc).
fn get_trait_impls(&self, tcx: TyCtxt<'_>) -> impl Iterator<Item = DefId> {
self.trait_impls.values().flat_map(move |impls| {
impls.decode((self, tcx)).map(move |(impl_index, _)| self.local_def_id(impl_index))
})
}
fn get_incoherent_impls<'tcx>(&self, tcx: TyCtxt<'tcx>, simp: SimplifiedType) -> &'tcx [DefId] {
if let Some(impls) = self.incoherent_impls.get(&simp) {
tcx.arena.alloc_from_iter(impls.decode((self, tcx)).map(|idx| self.local_def_id(idx)))
} else {
&[]
}
}
fn get_implementations_of_trait<'tcx>(
&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, tcx))
.map(|(idx, simplified_self_ty)| (self.local_def_id(idx), simplified_self_ty)),
)
} else {
&[]
}
}
fn get_native_libraries(&self, tcx: TyCtxt<'_>) -> impl Iterator<Item = NativeLib> {
self.root.native_libraries.decode((self, tcx))
}
fn get_proc_macro_quoted_span(&self, tcx: TyCtxt<'_>, index: usize) -> Span {
self.root
.tables
.proc_macro_quoted_spans
.get(self, index)
.unwrap_or_else(|| panic!("Missing proc macro quoted span: {index:?}"))
.decode((self, tcx))
}
fn get_foreign_modules(&self, tcx: TyCtxt<'_>) -> impl Iterator<Item = ForeignModule> {
self.root.foreign_modules.decode((self, tcx))
}
fn get_dylib_dependency_formats<'tcx>(
&self,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(CrateNum, LinkagePreference)] {
tcx.arena.alloc_from_iter(
self.root.dylib_dependency_formats.decode((self, tcx)).enumerate().flat_map(
|(i, link)| {
let cnum = CrateNum::new(i + 1); // We skipped LOCAL_CRATE when encoding
link.map(|link| (self.cnum_map[cnum], link))
},
),
)
}
fn get_externally_implementable_items(
&self,
tcx: TyCtxt<'_>,
) -> impl Iterator<Item = EiiMapEncodedKeyValue> {
self.root.externally_implementable_items.decode((self, tcx))
}
fn get_missing_lang_items<'tcx>(&self, tcx: TyCtxt<'tcx>) -> &'tcx [LangItem] {
tcx.arena.alloc_from_iter(self.root.lang_items_missing.decode((self, tcx)))
}
fn get_exportable_items(&self, tcx: TyCtxt<'_>) -> impl Iterator<Item = DefId> {
self.root.exportable_items.decode((self, tcx)).map(move |index| self.local_def_id(index))
}
fn get_stable_order_of_exportable_impls(
&self,
tcx: TyCtxt<'_>,
) -> impl Iterator<Item = (DefId, usize)> {
self.root
.stable_order_of_exportable_impls
.decode((self, tcx))
.map(move |v| (self.local_def_id(v.0), v.1))
}
fn exported_non_generic_symbols<'tcx>(
&self,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(ExportedSymbol<'tcx>, SymbolExportInfo)] {
tcx.arena.alloc_from_iter(self.root.exported_non_generic_symbols.decode((self, tcx)))
}
fn exported_generic_symbols<'tcx>(
&self,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(ExportedSymbol<'tcx>, SymbolExportInfo)] {
tcx.arena.alloc_from_iter(self.root.exported_generic_symbols.decode((self, tcx)))
}
fn get_macro(&self, tcx: TyCtxt<'_>, id: DefIndex) -> ast::MacroDef {
match self.def_kind(id) {
DefKind::Macro(_) => {
let macro_rules = self.root.tables.is_macro_rules.get(self, id);
let body =
self.root.tables.macro_definition.get(self, id).unwrap().decode((self, tcx));
ast::MacroDef { macro_rules, body: Box::new(body), eii_declaration: None }
}
_ => bug!(),
}
}
#[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.blob, index).unwrap().decode(&self.blob)
})
}
// 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))
}
#[inline]
fn def_path_hash(&self, index: DefIndex) -> DefPathHash {
// This is a hack to workaround the fact that we can't easily encode/decode a Hash64
// into the FixedSizeEncoding, as Hash64 lacks a Default impl. A future refactor to
// relax the Default restriction will likely fix this.
let fingerprint = Fingerprint::new(
self.root.stable_crate_id.as_u64(),
self.root.tables.def_path_hashes.get(&self.blob, index),
);
DefPathHash::new(self.root.stable_crate_id, fingerprint.split().1)
}
#[inline]
fn def_path_hash_to_def_index(&self, hash: DefPathHash) -> Option<DefIndex> {
self.def_path_hash_map.def_path_hash_to_def_index(&hash)
}
fn expn_hash_to_expn_id(&self, tcx: TyCtxt<'_>, index_guess: u32, hash: ExpnHash) -> ExpnId {
let index_guess = ExpnIndex::from_u32(index_guess);
let old_hash =
self.root.expn_hashes.get(self, index_guess).map(|lazy| lazy.decode((self, tcx)));
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.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, tcx)), i);
}
}
map
});
map[&hash]
};
let data = self.root.expn_data.get(self, index).unwrap().decode((self, tcx));
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_file(&self, tcx: TyCtxt<'_>, source_file_index: u32) -> ImportedSourceFile {
fn filter<'a>(
tcx: TyCtxt<'_>,
real_source_base_dir: &Option<PathBuf>,
path: Option<&'a Path>,
) -> Option<&'a Path> {
path.filter(|_| {
// Only spend time on further checks if we have what to translate *to*.
real_source_base_dir.is_some()
// Some tests need the translation to be always skipped.
&& tcx.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.
!tcx.sess.opts.remap_path_prefix.iter().any(|(_from, to)| to == virtual_dir)
})
}
let try_to_translate_virtual_to_real =
|virtual_source_base_dir: Option<&str>,
real_source_base_dir: &Option<PathBuf>,
name: &mut rustc_span::FileName| {
let virtual_source_base_dir = [
filter(tcx, real_source_base_dir, virtual_source_base_dir.map(Path::new)),
filter(
tcx,
real_source_base_dir,
tcx.sess.opts.unstable_opts.simulate_remapped_rust_src_base.as_deref(),
),
];
debug!(
"try_to_translate_virtual_to_real(name={:?}): \
virtual_source_base_dir={:?}, real_source_base_dir={:?}",
name, virtual_source_base_dir, real_source_base_dir,
);
for virtual_dir in virtual_source_base_dir.iter().flatten() {
if let Some(real_dir) = &real_source_base_dir
&& let rustc_span::FileName::Real(old_name) = name
&& let virtual_path = old_name.path(RemapPathScopeComponents::MACRO)
&& let Ok(rest) = virtual_path.strip_prefix(virtual_dir)
{
let new_path = real_dir.join(rest);
debug!(
"try_to_translate_virtual_to_real: `{}` -> `{}`",
virtual_path.display(),
new_path.display(),
);
// Check if the translated real path is affected by any user-requested
// remaps via --remap-path-prefix. Apply them if so.
// Note that this is a special case for imported rust-src paths specified by
// https://rust-lang.github.io/rfcs/3127-trim-paths.html#handling-sysroot-paths.
// Other imported paths are not currently remapped (see #66251).
*name = rustc_span::FileName::Real(
tcx.sess
.source_map()
.path_mapping()
.to_real_filename(&rustc_span::RealFileName::empty(), new_path),
);
}
}
};
let try_to_translate_real_to_virtual =
|virtual_source_base_dir: Option<&str>,
real_source_base_dir: &Option<PathBuf>,
subdir: &str,
name: &mut rustc_span::FileName| {
if let Some(virtual_dir) =
&tcx.sess.opts.unstable_opts.simulate_remapped_rust_src_base
&& let Some(real_dir) = real_source_base_dir
&& let rustc_span::FileName::Real(old_name) = name
{
let (_working_dir, embeddable_path) =
old_name.embeddable_name(RemapPathScopeComponents::MACRO);
let relative_path = embeddable_path.strip_prefix(real_dir).ok().or_else(|| {
virtual_source_base_dir
.and_then(|virtual_dir| embeddable_path.strip_prefix(virtual_dir).ok())
});
debug!(
?relative_path,
?virtual_dir,
?subdir,
"simulate_remapped_rust_src_base"
);
if let Some(rest) = relative_path.and_then(|p| p.strip_prefix(subdir).ok()) {
*name =
rustc_span::FileName::Real(rustc_span::RealFileName::from_virtual_path(
&virtual_dir.join(subdir).join(rest),
))
}
}
};
let mut import_info = self.source_map_import_info.lock();
for _ in import_info.len()..=(source_file_index as usize) {
import_info.push(None);
}
import_info[source_file_index as usize]
.get_or_insert_with(|| {
let source_file_to_import = self
.root
.source_map
.get(self, source_file_index)
.expect("missing source file")
.decode((self, tcx));
// We can't reuse an existing SourceFile, so allocate a new one
// containing the information we need.
let original_end_pos = source_file_to_import.end_position();
let rustc_span::SourceFile {
mut name,
src_hash,
checksum_hash,
start_pos: original_start_pos,
normalized_source_len,
unnormalized_source_len,
lines,
multibyte_chars,
normalized_pos,
stable_id,
..
} = source_file_to_import;
// If this file is under $sysroot/lib/rustlib/src/
// and the user wish to simulate remapping with -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.
try_to_translate_real_to_virtual(
option_env!("CFG_VIRTUAL_RUST_SOURCE_BASE_DIR"),
&tcx.sess.opts.real_rust_source_base_dir,
"library",
&mut name,
);
// If this file is under $sysroot/lib/rustlib/rustc-src/
// and the user wish to simulate remapping with -Z simulate-remapped-rust-src-base,
// then we change `name` to a similar state as if the rust was bootstrapped
// with `remap-debuginfo = true`.
try_to_translate_real_to_virtual(
option_env!("CFG_VIRTUAL_RUSTC_DEV_SOURCE_BASE_DIR"),
&tcx.sess.opts.real_rustc_dev_source_base_dir,
"compiler",
&mut name,
);
// If this file's path has been remapped to `/rustc/$hash`,
// we might be able to reverse that.
//
// 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`.
try_to_translate_virtual_to_real(
option_env!("CFG_VIRTUAL_RUST_SOURCE_BASE_DIR"),
&tcx.sess.opts.real_rust_source_base_dir,
&mut name,
);
// If this file's path has been remapped to `/rustc-dev/$hash`,
// we might be able to reverse that.
//
// NOTE: if you update this, you might need to also update bootstrap's code for generating
// the `rustc-dev` component in `Src::run` in `src/bootstrap/dist.rs`.
try_to_translate_virtual_to_real(
option_env!("CFG_VIRTUAL_RUSTC_DEV_SOURCE_BASE_DIR"),
&tcx.sess.opts.real_rustc_dev_source_base_dir,
&mut name,
);
let local_version = tcx.sess.source_map().new_imported_source_file(
name,
src_hash,
checksum_hash,
stable_id,
normalized_source_len.to_u32(),
unnormalized_source_len,
self.cnum,
lines,
multibyte_chars,
normalized_pos,
source_file_index,
);
debug!(
"CrateMetaData::imported_source_files alloc \
source_file {:?} original (start_pos {:?} source_len {:?}) \
translated (start_pos {:?} source_len {:?})",
local_version.name,
original_start_pos,
normalized_source_len,
local_version.start_pos,
local_version.normalized_source_len
);
ImportedSourceFile {
original_start_pos,
original_end_pos,
translated_source_file: local_version,
}
})
.clone()
}
fn get_attr_flags(&self, index: DefIndex) -> AttrFlags {
self.root.tables.attr_flags.get(self, index)
}
fn get_intrinsic(&self, tcx: TyCtxt<'_>, index: DefIndex) -> Option<ty::IntrinsicDef> {
self.root.tables.intrinsic.get(self, index).map(|d| d.decode((self, tcx)))
}
fn get_doc_link_resolutions(&self, tcx: TyCtxt<'_>, index: DefIndex) -> DocLinkResMap {
self.root
.tables
.doc_link_resolutions
.get(self, index)
.expect("no resolutions for a doc link")
.decode((self, tcx))
}
fn get_doc_link_traits_in_scope(
&self,
tcx: TyCtxt<'_>,
index: DefIndex,
) -> impl Iterator<Item = DefId> {
self.root
.tables
.doc_link_traits_in_scope
.get(self, index)
.expect("no traits in scope for a doc link")
.decode((self, tcx))
}
}
impl CrateMetadata {
pub(crate) fn new(
tcx: TyCtxt<'_>,
blob: MetadataBlob,
root: CrateRoot,
raw_proc_macros: Option<&'static [ProcMacroClient]>,
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)
.map(|trait_impls| (trait_impls.trait_id, trait_impls.impls))
.collect();
let alloc_decoding_state =
AllocDecodingState::new(root.interpret_alloc_index.decode(&blob).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: Lock::new(Vec::new()),
def_path_hash_map,
expn_hash_map: Default::default(),
alloc_decoding_state,
cnum,
cnum_map,
dep_kind,
source: Arc::new(source),
private_dep,
host_hash,
used: false,
extern_crate: None,
hygiene_context: Default::default(),
def_key_cache: Default::default(),
};
cdata.incoherent_impls = cdata
.root
.incoherent_impls
.decode((&cdata, tcx))
.map(|incoherent_impls| {
(incoherent_impls.self_ty.decode((&cdata, tcx)), incoherent_impls.impls)
})
.collect();
cdata
}
pub(crate) fn dependencies(&self) -> impl Iterator<Item = CrateNum> {
self.cnum_map.iter().copied()
}
pub(crate) fn target_modifiers(&self) -> TargetModifiers {
self.root.decode_target_modifiers(&self.blob).collect()
}
pub(crate) fn enabled_denied_partial_mitigations(&self) -> DeniedPartialMitigations {
self.root.decode_denied_partial_mitigations(&self.blob).collect()
}
/// Keep `new_extern_crate` if it looks better in diagnostics
pub(crate) fn update_extern_crate_diagnostics(
&mut self,
new_extern_crate: ExternCrate,
) -> bool {
let update =
self.extern_crate.as_ref().is_none_or(|old| old.rank() < new_extern_crate.rank());
if update {
self.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
}
pub(crate) fn set_dep_kind(&mut self, dep_kind: CrateDepKind) {
self.dep_kind = dep_kind;
}
pub(crate) fn update_and_private_dep(&mut self, private_dep: bool) {
self.private_dep &= private_dep;
}
pub(crate) fn used(&self) -> bool {
self.used
}
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_private_dep(&self) -> bool {
self.private_dep
}
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 is_compiler_builtins(&self) -> bool {
self.root.compiler_builtins
}
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_alloc_error_handler(&self) -> bool {
self.root.has_alloc_error_handler
}
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 proc_macros_for_crate(
&self,
tcx: TyCtxt<'_>,
krate: CrateNum,
) -> impl Iterator<Item = DefId> {
gen move {
if let Some(data) = &self.root.proc_macro_data {
for def_id in
data.macros.decode((self, tcx)).map(move |(index, _)| DefId { index, krate })
{
yield def_id;
}
}
}
}
pub(crate) fn name(&self) -> Symbol {
self.root.header.name
}
pub(crate) fn hash(&self) -> Svh {
self.root.header.hash
}
pub(crate) fn has_async_drops(&self) -> bool {
self.root.tables.adt_async_destructor.len > 0
}
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
}
}