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fuchsia / third_party / rust / 5fd9c059efaa76efeb2c85782a94aec343fd8bdc / . / compiler / rustc_metadata / src / rmeta / decoder.rs
blob: 220bc9c5f752f556bcf41e55b433f3043e68ef56 [file] [log] [blame]
// Decoding metadata from a single crate's metadata
use crate::creader::CrateMetadataRef;
use crate::rmeta::table::{FixedSizeEncoding, Table};
use crate::rmeta::*;
use rustc_ast as ast;
use rustc_attr as attr;
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_errors::ErrorReported;
use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
use rustc_expand::proc_macro::{AttrProcMacro, BangProcMacro, ProcMacroDerive};
use rustc_hir as hir;
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, SymbolExportLevel};
use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
use rustc_middle::mir::{self, Body, Promoted};
use rustc_middle::thir;
use rustc_middle::ty::codec::TyDecoder;
use rustc_middle::ty::fast_reject::SimplifiedType;
use rustc_middle::ty::{self, Ty, TyCtxt, Visibility};
use rustc_serialize::{opaque, 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::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)]
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.
crate type CrateNumMap = IndexVec<CrateNum, CrateNum>;
crate struct CrateMetadata {
/// The primary crate data - binary metadata blob.
blob: MetadataBlob,
// --- Some data pre-decoded from the metadata blob, usually for performance ---
/// Properties of the whole crate.
/// NOTE(eddyb) we pass `'static` to a `'tcx` parameter because this
/// lifetime is only used behind `Lazy`, and therefore acts like a
/// universal (`for<'tcx>`), that is paired up with whichever `TyCtxt`
/// is being used to decode those values.
root: CrateRoot<'static>,
/// 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), Lazy<[(DefIndex, Option<SimplifiedType>)]>>,
/// 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: 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: opaque::Decoder<'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: opaque::Decoder::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<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> Lazy<T> {
fn decode<M: Metadata<'a, 'tcx>>(self, metadata: M) -> T {
let mut dcx = metadata.decoder(self.position.get());
dcx.lazy_state = LazyState::NodeStart(self.position);
T::decode(&mut dcx).unwrap()
}
}
impl<'a: 'x, 'tcx: 'x, 'x, T: Decodable<DecodeContext<'a, 'tcx>>> Lazy<[T]> {
fn decode<M: Metadata<'a, 'tcx>>(
self,
metadata: M,
) -> impl ExactSizeIterator<Item = T> + Captures<'a> + Captures<'tcx> + 'x {
let mut dcx = metadata.decoder(self.position.get());
dcx.lazy_state = LazyState::NodeStart(self.position);
(0..self.meta).map(move |_| T::decode(&mut dcx).unwrap())
}
}
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()
}
fn map_encoded_cnum_to_current(&self, cnum: CrateNum) -> CrateNum {
if cnum == LOCAL_CRATE { self.cdata().cnum } else { self.cdata().cnum_map[cnum] }
}
fn read_lazy_with_meta<T: ?Sized + LazyMeta>(
&mut self,
meta: T::Meta,
) -> Result<Lazy<T>, <Self as Decoder>::Error> {
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,
};
self.lazy_state = LazyState::Previous(NonZeroUsize::new(position).unwrap());
Ok(Lazy::from_position_and_meta(NonZeroUsize::new(position).unwrap(), meta))
}
#[inline]
pub fn read_raw_bytes(&mut self, len: usize) -> &'a [u8] {
self.opaque.read_raw_bytes(len)
}
}
impl<'a, 'tcx> TyDecoder<'tcx> for DecodeContext<'a, 'tcx> {
const CLEAR_CROSS_CRATE: bool = true;
#[inline]
fn tcx(&self) -> TyCtxt<'tcx> {
self.tcx.expect("missing TyCtxt in DecodeContext")
}
#[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,
) -> Result<Ty<'tcx>, Self::Error>
where
F: FnOnce(&mut Self) -> Result<Ty<'tcx>, Self::Error>,
{
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 Ok(ty);
}
let ty = or_insert_with(self)?;
tcx.ty_rcache.borrow_mut().insert(key, ty);
Ok(ty)
}
fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
where
F: FnOnce(&mut Self) -> R,
{
let new_opaque = opaque::Decoder::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) -> Result<rustc_middle::mir::interpret::AllocId, Self::Error> {
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>) -> Result<CrateNum, String> {
let cnum = CrateNum::from_u32(d.read_u32()?);
Ok(d.map_encoded_cnum_to_current(cnum))
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for DefIndex {
fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Result<DefIndex, String> {
Ok(DefIndex::from_u32(d.read_u32()?))
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for ExpnIndex {
fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Result<ExpnIndex, String> {
Ok(ExpnIndex::from_u32(d.read_u32()?))
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for SyntaxContext {
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Result<SyntaxContext, String> {
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);
Ok(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>) -> Result<ExpnId, String> {
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)
});
Ok(expn_id)
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for Span {
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Result<Span, String> {
let ctxt = SyntaxContext::decode(decoder)?;
let tag = u8::decode(decoder)?;
if tag == TAG_PARTIAL_SPAN {
return Ok(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 posibilites:
//
// 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.
Ok(Span::new(lo, hi, ctxt, None))
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for &'tcx [thir::abstract_const::Node<'tcx>] {
fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Result<Self, String> {
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>) -> Result<Self, String> {
ty::codec::RefDecodable::decode(d)
}
}
impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> Decodable<DecodeContext<'a, 'tcx>>
for Lazy<T>
{
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Result<Self, String> {
decoder.read_lazy_with_meta(())
}
}
impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> Decodable<DecodeContext<'a, 'tcx>>
for Lazy<[T]>
{
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Result<Self, String> {
let len = decoder.read_usize()?;
if len == 0 { Ok(Lazy::empty()) } else { decoder.read_lazy_with_meta(len) }
}
}
impl<'a, 'tcx, I: Idx, T: Decodable<DecodeContext<'a, 'tcx>>> Decodable<DecodeContext<'a, 'tcx>>
for Lazy<Table<I, T>>
where
Option<T>: FixedSizeEncoding,
{
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Result<Self, String> {
let len = decoder.read_usize()?;
decoder.read_lazy_with_meta(len)
}
}
implement_ty_decoder!(DecodeContext<'a, 'tcx>);
impl<'tcx> MetadataBlob {
crate fn new(metadata_ref: MetadataRef) -> MetadataBlob {
MetadataBlob(Lrc::new(metadata_ref))
}
crate fn is_compatible(&self) -> bool {
self.blob().starts_with(METADATA_HEADER)
}
crate fn get_rustc_version(&self) -> String {
Lazy::<String>::from_position(NonZeroUsize::new(METADATA_HEADER.len() + 4).unwrap())
.decode(self)
}
crate fn get_root(&self) -> CrateRoot<'tcx> {
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;
Lazy::<CrateRoot<'tcx>>::from_position(NonZeroUsize::new(pos).unwrap()).decode(self)
}
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<'_> {
crate fn is_proc_macro_crate(&self) -> bool {
self.proc_macro_data.is_some()
}
crate fn name(&self) -> Symbol {
self.name
}
crate fn hash(&self) -> Svh {
self.hash
}
crate fn stable_crate_id(&self) -> StableCrateId {
self.stable_crate_id
}
crate fn triple(&self) -> &TargetTriple {
&self.triple
}
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_ident(self, item_index: DefIndex, sess: &Session) -> Option<Ident> {
let name = self.def_key(item_index).disambiguated_data.data.get_opt_name()?;
let span = match self.root.tables.ident_span.get(self, item_index) {
Some(lazy_span) => lazy_span.decode((self, sess)),
None => {
// FIXME: this weird case of a name with no span is specific to `extern crate`
// items, which are supposed to be treated like `use` items and only be encoded
// to metadata as `Export`s, return `None` because that's what all the callers
// expect in this case.
assert_eq!(self.def_kind(item_index), DefKind::ExternCrate);
return None;
}
};
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))
}
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.def_kind.get(self, item_id).map(|k| k.decode(self)).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
.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(ProcMacroDerive { 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_trait_def(self, item_id: DefIndex, sess: &Session) -> ty::TraitDef {
match self.kind(item_id) {
EntryKind::Trait(data) => {
let data = data.decode((self, sess));
ty::TraitDef::new(
self.local_def_id(item_id),
data.unsafety,
data.paren_sugar,
data.has_auto_impl,
data.is_marker,
data.skip_array_during_method_dispatch,
data.specialization_kind,
self.def_path_hash(item_id),
data.must_implement_one_of,
)
}
EntryKind::TraitAlias => ty::TraitDef::new(
self.local_def_id(item_id),
hir::Unsafety::Normal,
false,
false,
false,
false,
ty::trait_def::TraitSpecializationKind::None,
self.def_path_hash(item_id),
None,
),
_ => bug!("def-index does not refer to trait or trait alias"),
}
}
fn get_variant(
self,
kind: &EntryKind,
index: DefIndex,
parent_did: DefId,
sess: &Session,
) -> 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_ident(index, sess).name,
variant_did,
ctor_did,
data.discr,
self.root
.tables
.children
.get(self, index)
.unwrap_or_else(Lazy::empty)
.decode(self)
.map(|index| ty::FieldDef {
did: self.local_def_id(index),
name: self.item_ident(index, sess).name,
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>) -> &'tcx ty::AdtDef {
let kind = self.kind(item_id);
let did = self.local_def_id(item_id);
let (adt_kind, repr) = match kind {
EntryKind::Enum(repr) => (ty::AdtKind::Enum, repr),
EntryKind::Struct(_, repr) => (ty::AdtKind::Struct, repr),
EntryKind::Union(_, repr) => (ty::AdtKind::Union, repr),
_ => bug!("get_adt_def called on a non-ADT {:?}", did),
};
let variants = if let ty::AdtKind::Enum = adt_kind {
self.root
.tables
.children
.get(self, item_id)
.unwrap_or_else(Lazy::empty)
.decode(self)
.map(|index| self.get_variant(&self.kind(index), index, did, tcx.sess))
.collect()
} else {
std::iter::once(self.get_variant(&kind, item_id, did, tcx.sess)).collect()
};
tcx.alloc_adt_def(did, adt_kind, variants, repr)
}
fn get_explicit_predicates(
self,
item_id: DefIndex,
tcx: TyCtxt<'tcx>,
) -> ty::GenericPredicates<'tcx> {
self.root.tables.explicit_predicates.get(self, item_id).unwrap().decode((self, tcx))
}
fn get_inferred_outlives(
self,
item_id: DefIndex,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(ty::Predicate<'tcx>, Span)] {
self.root
.tables
.inferred_outlives
.get(self, item_id)
.map(|predicates| tcx.arena.alloc_from_iter(predicates.decode((self, tcx))))
.unwrap_or_default()
}
fn get_super_predicates(
self,
item_id: DefIndex,
tcx: TyCtxt<'tcx>,
) -> ty::GenericPredicates<'tcx> {
self.root.tables.super_predicates.get(self, item_id).unwrap().decode((self, tcx))
}
fn get_explicit_item_bounds(
self,
item_id: DefIndex,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(ty::Predicate<'tcx>, Span)] {
self.root
.tables
.explicit_item_bounds
.get(self, item_id)
.map(|bounds| tcx.arena.alloc_from_iter(bounds.decode((self, tcx))))
.unwrap_or_default()
}
fn get_generics(self, item_id: DefIndex, sess: &Session) -> ty::Generics {
self.root.tables.generics.get(self, item_id).unwrap().decode((self, sess))
}
fn get_type(self, id: DefIndex, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
self.root
.tables
.ty
.get(self, id)
.unwrap_or_else(|| panic!("Not a type: {:?}", id))
.decode((self, tcx))
}
fn get_stability(self, id: DefIndex) -> Option<attr::Stability> {
self.root.tables.stability.get(self, id).map(|stab| stab.decode(self))
}
fn get_const_stability(self, id: DefIndex) -> Option<attr::ConstStability> {
self.root.tables.const_stability.get(self, id).map(|stab| stab.decode(self))
}
fn get_deprecation(self, id: DefIndex) -> Option<attr::Deprecation> {
self.root.tables.deprecation.get(self, id).map(|depr| depr.decode(self))
}
fn get_visibility(self, id: DefIndex) -> ty::Visibility {
self.root.tables.visibility.get(self, id).unwrap().decode(self)
}
fn get_impl_data(self, id: DefIndex) -> ImplData {
match self.kind(id) {
EntryKind::Impl(data) => data.decode(self),
_ => bug!(),
}
}
fn get_parent_impl(self, id: DefIndex) -> Option<DefId> {
self.get_impl_data(id).parent_impl
}
fn get_impl_polarity(self, id: DefIndex) -> ty::ImplPolarity {
self.get_impl_data(id).polarity
}
fn get_impl_defaultness(self, id: DefIndex) -> hir::Defaultness {
self.get_impl_data(id).defaultness
}
fn get_impl_constness(self, id: DefIndex) -> hir::Constness {
self.get_impl_data(id).constness
}
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(self))
}
fn get_coerce_unsized_info(self, id: DefIndex) -> Option<ty::adjustment::CoerceUnsizedInfo> {
self.get_impl_data(id).coerce_unsized_info
}
fn get_impl_trait(self, id: DefIndex, tcx: TyCtxt<'tcx>) -> Option<ty::TraitRef<'tcx>> {
self.root.tables.impl_trait_ref.get(self, id).map(|tr| tr.decode((self, tcx)))
}
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_const_param_default(
self,
tcx: TyCtxt<'tcx>,
id: DefIndex,
) -> rustc_middle::ty::Const<'tcx> {
self.root.tables.const_defaults.get(self, id).unwrap().decode((self, tcx))
}
/// 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 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(|(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,
});
}
}
return;
}
// Iterate over all children.
if let Some(children) = self.root.tables.children.get(self, id) {
for child_index in children.decode((self, sess)) {
if let Some(ident) = self.opt_item_ident(child_index, sess) {
let kind = self.def_kind(child_index);
if matches!(kind, DefKind::Macro(..)) {
// FIXME: Macros are currently encoded twice, once as items and once as
// reexports. We ignore the items here and only use the reexports.
continue;
}
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);
callback(ModChild { ident, res, vis, span });
// 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 });
}
}
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 });
}
_ => {}
}
}
}
}
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.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_optimized_mir(self, tcx: TyCtxt<'tcx>, id: DefIndex) -> Body<'tcx> {
self.root
.tables
.mir
.get(self, id)
.unwrap_or_else(|| {
bug!("get_optimized_mir: missing MIR for `{:?}`", self.local_def_id(id))
})
.decode((self, tcx))
}
fn get_mir_for_ctfe(self, tcx: TyCtxt<'tcx>, id: DefIndex) -> Body<'tcx> {
self.root
.tables
.mir_for_ctfe
.get(self, id)
.unwrap_or_else(|| {
bug!("get_mir_for_ctfe: missing MIR for `{:?}`", self.local_def_id(id))
})
.decode((self, tcx))
}
fn get_thir_abstract_const(
self,
tcx: TyCtxt<'tcx>,
id: DefIndex,
) -> Result<Option<&'tcx [thir::abstract_const::Node<'tcx>]>, ErrorReported> {
self.root
.tables
.thir_abstract_consts
.get(self, id)
.map_or(Ok(None), |v| Ok(Some(v.decode((self, tcx)))))
}
fn get_unused_generic_params(self, id: DefIndex) -> FiniteBitSet<u32> {
self.root
.tables
.unused_generic_params
.get(self, id)
.map(|params| params.decode(self))
.unwrap_or_default()
}
fn get_promoted_mir(self, tcx: TyCtxt<'tcx>, id: DefIndex) -> IndexVec<Promoted, Body<'tcx>> {
self.root
.tables
.promoted_mir
.get(self, id)
.unwrap_or_else(|| {
bug!("get_promoted_mir: missing MIR for `{:?}`", self.local_def_id(id))
})
.decode((self, tcx))
}
fn mir_const_qualif(self, id: DefIndex) -> mir::ConstQualifs {
match self.kind(id) {
EntryKind::AnonConst(qualif, _)
| EntryKind::Const(qualif, _)
| EntryKind::AssocConst(
AssocContainer::ImplDefault
| AssocContainer::ImplFinal
| AssocContainer::TraitWithDefault,
qualif,
_,
) => qualif,
_ => bug!("mir_const_qualif: unexpected kind"),
}
}
fn get_fn_has_self_parameter(self, id: DefIndex) -> bool {
match self.kind(id) {
EntryKind::AssocFn(data) => data.decode(self).has_self,
_ => false,
}
}
fn get_associated_item_def_ids(self, tcx: TyCtxt<'tcx>, id: DefIndex) -> &'tcx [DefId] {
if let Some(children) = self.root.tables.children.get(self, id) {
tcx.arena.alloc_from_iter(
children.decode((self, tcx.sess)).map(|child_index| self.local_def_id(child_index)),
)
} else {
&[]
}
}
fn get_associated_item(self, id: DefIndex, sess: &Session) -> ty::AssocItem {
let def_key = self.def_key(id);
let parent = self.local_def_id(def_key.parent.unwrap());
let ident = self.item_ident(id, sess);
let (kind, container, has_self) = match self.kind(id) {
EntryKind::AssocConst(container, _, _) => (ty::AssocKind::Const, container, false),
EntryKind::AssocFn(data) => {
let data = data.decode(self);
(ty::AssocKind::Fn, data.container, data.has_self)
}
EntryKind::AssocType(container) => (ty::AssocKind::Type, container, false),
_ => bug!("cannot get associated-item of `{:?}`", def_key),
};
ty::AssocItem {
ident,
kind,
vis: self.get_visibility(id),
defaultness: container.defaultness(),
def_id: self.local_def_id(id),
trait_item_def_id: self.get_trait_item_def_id(id),
container: container.with_def_id(parent),
fn_has_self_parameter: has_self,
}
}
fn get_item_variances(self, id: DefIndex) -> impl Iterator<Item = ty::Variance> + 'a {
self.root.tables.variances.get(self, id).unwrap_or_else(Lazy::empty).decode(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(Lazy::empty)
.decode(self)
.map(move |index| respan(self.get_span(index, sess), self.item_ident(index, sess).name))
}
fn get_struct_field_visibilities(self, id: DefIndex) -> impl Iterator<Item = Visibility> + 'a {
self.root
.tables
.children
.get(self, id)
.unwrap_or_else(Lazy::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(Lazy::empty)
.decode(self)
.map(|index| self.local_def_id(index)),
)
}
fn get_traits(self) -> impl Iterator<Item = DefId> + 'a {
self.root.traits.decode(self).map(move |index| self.local_def_id(index))
}
fn get_trait_impls(self) -> impl Iterator<Item = (DefId, Option<SimplifiedType>)> + 'a {
self.cdata.trait_impls.values().flat_map(move |impls| {
impls
.decode(self)
.map(move |(idx, simplified_self_ty)| (self.local_def_id(idx), simplified_self_ty))
})
}
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_trait_of_item(self, id: DefIndex) -> Option<DefId> {
let def_key = self.def_key(id);
match def_key.disambiguated_data.data {
DefPathData::TypeNs(..) | DefPathData::ValueNs(..) => (),
// Not an associated item
_ => return None,
}
def_key.parent.and_then(|parent_index| match self.kind(parent_index) {
EntryKind::Trait(_) | EntryKind::TraitAlias => Some(self.local_def_id(parent_index)),
_ => None,
})
}
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 get_fn_param_names(self, tcx: TyCtxt<'tcx>, id: DefIndex) -> &'tcx [Ident] {
let param_names = match self.kind(id) {
EntryKind::Fn(data) | EntryKind::ForeignFn(data) => data.decode(self).param_names,
EntryKind::AssocFn(data) => data.decode(self).fn_data.param_names,
_ => Lazy::empty(),
};
tcx.arena.alloc_from_iter(param_names.decode((self, tcx)))
}
fn exported_symbols(
self,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(ExportedSymbol<'tcx>, SymbolExportLevel)] {
tcx.arena.alloc_from_iter(self.root.exported_symbols.decode((self, tcx)))
}
fn get_rendered_const(self, id: DefIndex) -> String {
match self.kind(id) {
EntryKind::AnonConst(_, data)
| EntryKind::Const(_, data)
| EntryKind::AssocConst(_, _, data) => data.decode(self).0,
_ => bug!(),
}
}
fn get_macro(self, id: DefIndex, sess: &Session) -> MacroDef {
match self.kind(id) {
EntryKind::MacroDef(macro_def) => macro_def.decode((self, sess)),
_ => bug!(),
}
}
// This replicates some of the logic of the crate-local `is_const_fn_raw` query, because we
// don't serialize constness for tuple variant and tuple struct constructors.
fn is_const_fn_raw(self, id: DefIndex) -> bool {
let constness = match self.kind(id) {
EntryKind::AssocFn(data) => data.decode(self).fn_data.constness,
EntryKind::Fn(data) => data.decode(self).constness,
EntryKind::ForeignFn(data) => data.decode(self).constness,
EntryKind::Variant(..) | EntryKind::Struct(..) => hir::Constness::Const,
_ => hir::Constness::NotConst,
};
constness == hir::Constness::Const
}
fn asyncness(self, id: DefIndex) -> hir::IsAsync {
match self.kind(id) {
EntryKind::Fn(data) => data.decode(self).asyncness,
EntryKind::AssocFn(data) => data.decode(self).fn_data.asyncness,
EntryKind::ForeignFn(data) => data.decode(self).asyncness,
_ => bug!("asyncness: expected function kind"),
}
}
fn is_foreign_item(self, id: DefIndex) -> bool {
match self.kind(id) {
EntryKind::ForeignImmStatic | EntryKind::ForeignMutStatic | EntryKind::ForeignFn(_) => {
true
}
_ => false,
}
}
fn static_mutability(self, id: DefIndex) -> Option<hir::Mutability> {
match self.kind(id) {
EntryKind::ImmStatic | EntryKind::ForeignImmStatic => Some(hir::Mutability::Not),
EntryKind::MutStatic | EntryKind::ForeignMutStatic => Some(hir::Mutability::Mut),
_ => None,
}
}
fn generator_kind(self, id: DefIndex) -> Option<hir::GeneratorKind> {
match self.kind(id) {
EntryKind::Generator(data) => Some(data),
_ => None,
}
}
fn fn_sig(self, id: DefIndex, tcx: TyCtxt<'tcx>) -> ty::PolyFnSig<'tcx> {
self.root.tables.fn_sig.get(self, id).unwrap().decode((self, tcx))
}
#[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().decode(self)
})
}
#[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] {
// Translate the virtual `/rustc/$hash` prefix back to a real directory
// that should hold actual sources, where possible.
//
// NOTE: if you update this, you might need to also update bootstrap's code for generating
// the `rust-src` component in `Src::run` in `src/bootstrap/dist.rs`.
let virtual_rust_source_base_dir = option_env!("CFG_VIRTUAL_RUST_SOURCE_BASE_DIR")
.map(Path::new)
.filter(|_| {
// Only spend time on further checks if we have what to translate *to*.
sess.opts.real_rust_source_base_dir.is_some()
})
.filter(|virtual_dir| {
// Don't translate away `/rustc/$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)
});
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,
);
if let Some(virtual_dir) = virtual_rust_source_base_dir {
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,
mut lines,
mut multibyte_chars,
mut non_narrow_chars,
mut normalized_pos,
name_hash,
..
} = source_file_to_import;
// If this file is under $sysroot/lib/rustlib/src/ but has not been remapped
// during rust bootstrapping by `remap-debuginfo = true`, and the user
// wish to simulate that behaviour by -Z simulate-remapped-rust-src-base,
// then we change `name` to a similar state as if the rust was bootstrapped
// with `remap-debuginfo = true`.
// This is useful for testing so that tests about the effects of
// `try_to_translate_virtual_to_real` don't have to worry about how the
// compiler is bootstrapped.
if let Some(virtual_dir) =
&sess.opts.debugging_opts.simulate_remapped_rust_src_base
{
if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
if let rustc_span::FileName::Real(ref mut old_name) = name {
if let rustc_span::RealFileName::LocalPath(local) = old_name {
if let Ok(rest) = local.strip_prefix(real_dir) {
*old_name = rustc_span::RealFileName::Remapped {
local_path: None,
virtual_name: virtual_dir.join(rest),
};
}
}
}
}
}
// If this file's path has been remapped to `/rustc/$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();
// Translate line-start positions and multibyte character
// position into frame of reference local to file.
// `SourceMap::new_imported_source_file()` will then translate those
// coordinates to their new global frame of reference when the
// offset of the SourceFile is known.
for pos in &mut lines {
*pos = *pos - start_pos;
}
for mbc in &mut multibyte_chars {
mbc.pos = mbc.pos - start_pos;
}
for swc in &mut non_narrow_chars {
*swc = *swc - start_pos;
}
for np in &mut normalized_pos {
np.pos = np.pos - start_pos;
}
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()
})
}
}
impl CrateMetadata {
crate fn new(
sess: &Session,
blob: MetadataBlob,
root: CrateRoot<'static>,
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);
CrateMetadata {
blob,
root,
trait_impls,
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,
private_dep,
host_hash,
extern_crate: Lock::new(None),
hygiene_context: Default::default(),
def_key_cache: Default::default(),
def_path_hash_cache: Default::default(),
}
}
crate fn dependencies(&self) -> LockGuard<'_, Vec<CrateNum>> {
self.dependencies.borrow()
}
crate fn add_dependency(&self, cnum: CrateNum) {
self.dependencies.borrow_mut().push(cnum);
}
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
}
crate fn source(&self) -> &CrateSource {
&self.source
}
crate fn dep_kind(&self) -> CrateDepKind {
*self.dep_kind.lock()
}
crate fn update_dep_kind(&self, f: impl FnOnce(CrateDepKind) -> CrateDepKind) {
self.dep_kind.with_lock(|dep_kind| *dep_kind = f(*dep_kind))
}
crate fn panic_strategy(&self) -> PanicStrategy {
self.root.panic_strategy
}
crate fn needs_panic_runtime(&self) -> bool {
self.root.needs_panic_runtime
}
crate fn is_panic_runtime(&self) -> bool {
self.root.panic_runtime
}
crate fn is_profiler_runtime(&self) -> bool {
self.root.profiler_runtime
}
crate fn needs_allocator(&self) -> bool {
self.root.needs_allocator
}
crate fn has_global_allocator(&self) -> bool {
self.root.has_global_allocator
}
crate fn has_default_lib_allocator(&self) -> bool {
self.root.has_default_lib_allocator
}
crate fn is_proc_macro_crate(&self) -> bool {
self.root.is_proc_macro_crate()
}
crate fn name(&self) -> Symbol {
self.root.name
}
crate fn stable_crate_id(&self) -> StableCrateId {
self.root.stable_crate_id
}
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,
}
}