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android / toolchain / rustc / b1d328019a485dc2e58d5dc46556067c927ec9f2 / . / compiler / rustc_metadata / src / rmeta / decoder.rs
blob: 40dc4fb052d9652767243e185465767954979847 [file] [log] [blame]
// Decoding metadata from a single crate's metadata
use crate::creader::{CStore, CrateMetadataRef};
use crate::rmeta::*;
use rustc_ast as ast;
use rustc_ast::ptr::P;
use rustc_data_structures::captures::Captures;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::svh::Svh;
use rustc_data_structures::sync::{Lock, LockGuard, Lrc, OnceCell};
use rustc_data_structures::unhash::UnhashMap;
use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
use rustc_expand::proc_macro::{AttrProcMacro, BangProcMacro, DeriveProcMacro};
use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
use rustc_hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
use rustc_hir::definitions::{DefKey, DefPath, DefPathData, DefPathHash};
use rustc_hir::diagnostic_items::DiagnosticItems;
use rustc_hir::lang_items;
use rustc_index::vec::{Idx, IndexVec};
use rustc_middle::metadata::ModChild;
use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo};
use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
use rustc_middle::ty::codec::TyDecoder;
use rustc_middle::ty::fast_reject::SimplifiedType;
use rustc_middle::ty::GeneratorDiagnosticData;
use rustc_middle::ty::{self, ParameterizedOverTcx, Ty, TyCtxt, Visibility};
use rustc_serialize::opaque::MemDecoder;
use rustc_serialize::{Decodable, Decoder};
use rustc_session::cstore::{
CrateSource, ExternCrate, ForeignModule, LinkagePreference, NativeLib,
};
use rustc_session::Session;
use rustc_span::hygiene::{ExpnIndex, MacroKind};
use rustc_span::source_map::{respan, Spanned};
use rustc_span::symbol::{sym, Ident, Symbol};
use rustc_span::{self, BytePos, ExpnId, Pos, Span, SyntaxContext, DUMMY_SP};
use proc_macro::bridge::client::ProcMacro;
use std::io;
use std::iter::TrustedLen;
use std::mem;
use std::num::NonZeroUsize;
use std::path::Path;
use tracing::debug;
pub(super) use cstore_impl::provide;
pub use cstore_impl::provide_extern;
use rustc_span::hygiene::HygieneDecodeContext;
mod cstore_impl;
/// A reference to the raw binary version of crate metadata.
/// A `MetadataBlob` internally is just a reference counted pointer to
/// the actual data, so cloning it is cheap.
#[derive(Clone)]
pub(crate) struct MetadataBlob(Lrc<MetadataRef>);
// This is needed so we can create an OwningRef into the blob.
// The data behind a `MetadataBlob` has a stable address because it is
// contained within an Rc/Arc.
unsafe impl rustc_data_structures::owning_ref::StableAddress for MetadataBlob {}
// This is needed so we can create an OwningRef into the blob.
impl std::ops::Deref for MetadataBlob {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
&self.0[..]
}
}
// A map from external crate numbers (as decoded from some crate file) to
// local crate numbers (as generated during this session). Each external
// crate may refer to types in other external crates, and each has their
// own crate numbers.
pub(crate) type CrateNumMap = IndexVec<CrateNum, CrateNum>;
pub(crate) struct CrateMetadata {
/// The primary crate data - binary metadata blob.
blob: MetadataBlob,
// --- Some data pre-decoded from the metadata blob, usually for performance ---
/// NOTE(eddyb) we pass `'static` to a `'tcx` parameter because this
/// lifetime is only used behind `LazyValue`, `LazyArray`, or `LazyTable`, and therefore acts like a
/// universal (`for<'tcx>`), that is paired up with whichever `TyCtxt`
/// is being used to decode those values.
root: CrateRoot,
/// Trait impl data.
/// FIXME: Used only from queries and can use query cache,
/// so pre-decoding can probably be avoided.
trait_impls: FxHashMap<(u32, DefIndex), LazyArray<(DefIndex, Option<SimplifiedType>)>>,
/// Inherent impls which do not follow the normal coherence rules.
///
/// These can be introduced using either `#![rustc_coherence_is_core]`
/// or `#[rustc_allow_incoherent_impl]`.
incoherent_impls: FxHashMap<SimplifiedType, LazyArray<DefIndex>>,
/// Proc macro descriptions for this crate, if it's a proc macro crate.
raw_proc_macros: Option<&'static [ProcMacro]>,
/// Source maps for code from the crate.
source_map_import_info: OnceCell<Vec<ImportedSourceFile>>,
/// For every definition in this crate, maps its `DefPathHash` to its `DefIndex`.
def_path_hash_map: DefPathHashMapRef<'static>,
/// Likewise for ExpnHash.
expn_hash_map: OnceCell<UnhashMap<ExpnHash, ExpnIndex>>,
/// Used for decoding interpret::AllocIds in a cached & thread-safe manner.
alloc_decoding_state: AllocDecodingState,
/// Caches decoded `DefKey`s.
def_key_cache: Lock<FxHashMap<DefIndex, DefKey>>,
/// Caches decoded `DefPathHash`es.
def_path_hash_cache: Lock<FxHashMap<DefIndex, DefPathHash>>,
// --- Other significant crate properties ---
/// ID of this crate, from the current compilation session's point of view.
cnum: CrateNum,
/// Maps crate IDs as they are were seen from this crate's compilation sessions into
/// IDs as they are seen from the current compilation session.
cnum_map: CrateNumMap,
/// Same ID set as `cnum_map` plus maybe some injected crates like panic runtime.
dependencies: Lock<Vec<CrateNum>>,
/// How to link (or not link) this crate to the currently compiled crate.
dep_kind: Lock<CrateDepKind>,
/// Filesystem location of this crate.
source: Lrc<CrateSource>,
/// Whether or not this crate should be consider a private dependency
/// for purposes of the 'exported_private_dependencies' lint
private_dep: bool,
/// The hash for the host proc macro. Used to support `-Z dual-proc-macro`.
host_hash: Option<Svh>,
/// Additional data used for decoding `HygieneData` (e.g. `SyntaxContext`
/// and `ExpnId`).
/// Note that we store a `HygieneDecodeContext` for each `CrateMetadat`. This is
/// because `SyntaxContext` ids are not globally unique, so we need
/// to track which ids we've decoded on a per-crate basis.
hygiene_context: HygieneDecodeContext,
// --- Data used only for improving diagnostics ---
/// Information about the `extern crate` item or path that caused this crate to be loaded.
/// If this is `None`, then the crate was injected (e.g., by the allocator).
extern_crate: Lock<Option<ExternCrate>>,
}
/// Holds information about a rustc_span::SourceFile imported from another crate.
/// See `imported_source_files()` for more information.
struct ImportedSourceFile {
/// This SourceFile's byte-offset within the source_map of its original crate
original_start_pos: rustc_span::BytePos,
/// The end of this SourceFile within the source_map of its original crate
original_end_pos: rustc_span::BytePos,
/// The imported SourceFile's representation within the local source_map
translated_source_file: Lrc<rustc_span::SourceFile>,
}
pub(super) struct DecodeContext<'a, 'tcx> {
opaque: MemDecoder<'a>,
cdata: Option<CrateMetadataRef<'a>>,
blob: &'a MetadataBlob,
sess: Option<&'tcx Session>,
tcx: Option<TyCtxt<'tcx>>,
// Cache the last used source_file for translating spans as an optimization.
last_source_file_index: usize,
lazy_state: LazyState,
// Used for decoding interpret::AllocIds in a cached & thread-safe manner.
alloc_decoding_session: Option<AllocDecodingSession<'a>>,
}
/// Abstract over the various ways one can create metadata decoders.
pub(super) trait Metadata<'a, 'tcx>: Copy {
fn blob(self) -> &'a MetadataBlob;
fn cdata(self) -> Option<CrateMetadataRef<'a>> {
None
}
fn sess(self) -> Option<&'tcx Session> {
None
}
fn tcx(self) -> Option<TyCtxt<'tcx>> {
None
}
fn decoder(self, pos: usize) -> DecodeContext<'a, 'tcx> {
let tcx = self.tcx();
DecodeContext {
opaque: MemDecoder::new(self.blob(), pos),
cdata: self.cdata(),
blob: self.blob(),
sess: self.sess().or(tcx.map(|tcx| tcx.sess)),
tcx,
last_source_file_index: 0,
lazy_state: LazyState::NoNode,
alloc_decoding_session: self
.cdata()
.map(|cdata| cdata.cdata.alloc_decoding_state.new_decoding_session()),
}
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for &'a MetadataBlob {
#[inline]
fn blob(self) -> &'a MetadataBlob {
self
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a MetadataBlob, &'tcx Session) {
#[inline]
fn blob(self) -> &'a MetadataBlob {
self.0
}
#[inline]
fn sess(self) -> Option<&'tcx Session> {
let (_, sess) = self;
Some(sess)
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for CrateMetadataRef<'a> {
#[inline]
fn blob(self) -> &'a MetadataBlob {
&self.cdata.blob
}
#[inline]
fn cdata(self) -> Option<CrateMetadataRef<'a>> {
Some(self)
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for (CrateMetadataRef<'a>, &'tcx Session) {
#[inline]
fn blob(self) -> &'a MetadataBlob {
&self.0.cdata.blob
}
#[inline]
fn cdata(self) -> Option<CrateMetadataRef<'a>> {
Some(self.0)
}
#[inline]
fn sess(self) -> Option<&'tcx Session> {
Some(self.1)
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for (CrateMetadataRef<'a>, TyCtxt<'tcx>) {
#[inline]
fn blob(self) -> &'a MetadataBlob {
&self.0.cdata.blob
}
#[inline]
fn cdata(self) -> Option<CrateMetadataRef<'a>> {
Some(self.0)
}
#[inline]
fn tcx(self) -> Option<TyCtxt<'tcx>> {
Some(self.1)
}
}
impl<T: ParameterizedOverTcx> LazyValue<T> {
fn decode<'a, 'tcx, M: Metadata<'a, 'tcx>>(self, metadata: M) -> T::Value<'tcx>
where
T::Value<'tcx>: Decodable<DecodeContext<'a, 'tcx>>,
{
let mut dcx = metadata.decoder(self.position.get());
dcx.lazy_state = LazyState::NodeStart(self.position);
T::Value::decode(&mut dcx)
}
}
struct DecodeIterator<'a, 'tcx, T> {
elem_counter: std::ops::Range<usize>,
dcx: DecodeContext<'a, 'tcx>,
_phantom: PhantomData<fn() -> T>,
}
impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> Iterator for DecodeIterator<'a, 'tcx, T> {
type Item = T;
#[inline(always)]
fn next(&mut self) -> Option<Self::Item> {
self.elem_counter.next().map(|_| T::decode(&mut self.dcx))
}
#[inline(always)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.elem_counter.size_hint()
}
}
impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> ExactSizeIterator
for DecodeIterator<'a, 'tcx, T>
{
fn len(&self) -> usize {
self.elem_counter.len()
}
}
unsafe impl<'a, 'tcx, T: Decodable<DecodeContext<'a, 'tcx>>> TrustedLen
for DecodeIterator<'a, 'tcx, T>
{
}
impl<T: ParameterizedOverTcx> LazyArray<T> {
fn decode<'a, 'tcx, M: Metadata<'a, 'tcx>>(
self,
metadata: M,
) -> DecodeIterator<'a, 'tcx, T::Value<'tcx>>
where
T::Value<'tcx>: Decodable<DecodeContext<'a, 'tcx>>,
{
let mut dcx = metadata.decoder(self.position.get());
dcx.lazy_state = LazyState::NodeStart(self.position);
DecodeIterator { elem_counter: (0..self.num_elems), dcx, _phantom: PhantomData }
}
}
impl<'a, 'tcx> DecodeContext<'a, 'tcx> {
#[inline]
fn tcx(&self) -> TyCtxt<'tcx> {
debug_assert!(self.tcx.is_some(), "missing TyCtxt in DecodeContext");
self.tcx.unwrap()
}
#[inline]
pub fn blob(&self) -> &'a MetadataBlob {
self.blob
}
#[inline]
pub fn cdata(&self) -> CrateMetadataRef<'a> {
debug_assert!(self.cdata.is_some(), "missing CrateMetadata in DecodeContext");
self.cdata.unwrap()
}
#[inline]
fn map_encoded_cnum_to_current(&self, cnum: CrateNum) -> CrateNum {
self.cdata().map_encoded_cnum_to_current(cnum)
}
#[inline]
fn read_lazy_offset_then<T>(&mut self, f: impl Fn(NonZeroUsize) -> T) -> T {
let distance = self.read_usize();
let position = match self.lazy_state {
LazyState::NoNode => bug!("read_lazy_with_meta: outside of a metadata node"),
LazyState::NodeStart(start) => {
let start = start.get();
assert!(distance <= start);
start - distance
}
LazyState::Previous(last_pos) => last_pos.get() + distance,
};
let position = NonZeroUsize::new(position).unwrap();
self.lazy_state = LazyState::Previous(position);
f(position)
}
fn read_lazy<T>(&mut self) -> LazyValue<T> {
self.read_lazy_offset_then(|pos| LazyValue::from_position(pos))
}
fn read_lazy_array<T>(&mut self, len: usize) -> LazyArray<T> {
self.read_lazy_offset_then(|pos| LazyArray::from_position_and_num_elems(pos, len))
}
fn read_lazy_table<I, T>(&mut self, len: usize) -> LazyTable<I, T> {
self.read_lazy_offset_then(|pos| LazyTable::from_position_and_encoded_size(pos, len))
}
#[inline]
pub fn read_raw_bytes(&mut self, len: usize) -> &[u8] {
self.opaque.read_raw_bytes(len)
}
}
impl<'a, 'tcx> TyDecoder for DecodeContext<'a, 'tcx> {
const CLEAR_CROSS_CRATE: bool = true;
type I = TyCtxt<'tcx>;
#[inline]
fn interner(&self) -> Self::I {
self.tcx()
}
#[inline]
fn peek_byte(&self) -> u8 {
self.opaque.data[self.opaque.position()]
}
#[inline]
fn position(&self) -> usize {
self.opaque.position()
}
fn cached_ty_for_shorthand<F>(&mut self, shorthand: usize, or_insert_with: F) -> Ty<'tcx>
where
F: FnOnce(&mut Self) -> Ty<'tcx>,
{
let tcx = self.tcx();
let key = ty::CReaderCacheKey { cnum: Some(self.cdata().cnum), pos: shorthand };
if let Some(&ty) = tcx.ty_rcache.borrow().get(&key) {
return ty;
}
let ty = or_insert_with(self);
tcx.ty_rcache.borrow_mut().insert(key, ty);
ty
}
fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
where
F: FnOnce(&mut Self) -> R,
{
let new_opaque = MemDecoder::new(self.opaque.data, pos);
let old_opaque = mem::replace(&mut self.opaque, new_opaque);
let old_state = mem::replace(&mut self.lazy_state, LazyState::NoNode);
let r = f(self);
self.opaque = old_opaque;
self.lazy_state = old_state;
r
}
fn decode_alloc_id(&mut self) -> rustc_middle::mir::interpret::AllocId {
if let Some(alloc_decoding_session) = self.alloc_decoding_session {
alloc_decoding_session.decode_alloc_id(self)
} else {
bug!("Attempting to decode interpret::AllocId without CrateMetadata")
}
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for CrateNum {
fn decode(d: &mut DecodeContext<'a, 'tcx>) -> CrateNum {
let cnum = CrateNum::from_u32(d.read_u32());
d.map_encoded_cnum_to_current(cnum)
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for DefIndex {
fn decode(d: &mut DecodeContext<'a, 'tcx>) -> DefIndex {
DefIndex::from_u32(d.read_u32())
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for ExpnIndex {
fn decode(d: &mut DecodeContext<'a, 'tcx>) -> ExpnIndex {
ExpnIndex::from_u32(d.read_u32())
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for SyntaxContext {
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> SyntaxContext {
let cdata = decoder.cdata();
let sess = decoder.sess.unwrap();
let cname = cdata.root.name;
rustc_span::hygiene::decode_syntax_context(decoder, &cdata.hygiene_context, |_, id| {
debug!("SpecializedDecoder<SyntaxContext>: decoding {}", id);
cdata
.root
.syntax_contexts
.get(cdata, id)
.unwrap_or_else(|| panic!("Missing SyntaxContext {:?} for crate {:?}", id, cname))
.decode((cdata, sess))
})
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for ExpnId {
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> ExpnId {
let local_cdata = decoder.cdata();
let sess = decoder.sess.unwrap();
let cnum = CrateNum::decode(decoder);
let index = u32::decode(decoder);
let expn_id = rustc_span::hygiene::decode_expn_id(cnum, index, |expn_id| {
let ExpnId { krate: cnum, local_id: index } = expn_id;
// Lookup local `ExpnData`s in our own crate data. Foreign `ExpnData`s
// are stored in the owning crate, to avoid duplication.
debug_assert_ne!(cnum, LOCAL_CRATE);
let crate_data = if cnum == local_cdata.cnum {
local_cdata
} else {
local_cdata.cstore.get_crate_data(cnum)
};
let expn_data = crate_data
.root
.expn_data
.get(crate_data, index)
.unwrap()
.decode((crate_data, sess));
let expn_hash = crate_data
.root
.expn_hashes
.get(crate_data, index)
.unwrap()
.decode((crate_data, sess));
(expn_data, expn_hash)
});
expn_id
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for Span {
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Span {
let ctxt = SyntaxContext::decode(decoder);
let tag = u8::decode(decoder);
if tag == TAG_PARTIAL_SPAN {
return DUMMY_SP.with_ctxt(ctxt);
}
debug_assert!(tag == TAG_VALID_SPAN_LOCAL || tag == TAG_VALID_SPAN_FOREIGN);
let lo = BytePos::decode(decoder);
let len = BytePos::decode(decoder);
let hi = lo + len;
let Some(sess) = decoder.sess else {
bug!("Cannot decode Span without Session.")
};
// There are two possibilities here:
// 1. This is a 'local span', which is located inside a `SourceFile`
// that came from this crate. In this case, we use the source map data
// encoded in this crate. This branch should be taken nearly all of the time.
// 2. This is a 'foreign span', which is located inside a `SourceFile`
// that came from a *different* crate (some crate upstream of the one
// whose metadata we're looking at). For example, consider this dependency graph:
//
// A -> B -> C
//
// Suppose that we're currently compiling crate A, and start deserializing
// metadata from crate B. When we deserialize a Span from crate B's metadata,
// there are two possibilities:
//
// 1. The span references a file from crate B. This makes it a 'local' span,
// which means that we can use crate B's serialized source map information.
// 2. The span references a file from crate C. This makes it a 'foreign' span,
// which means we need to use Crate *C* (not crate B) to determine the source
// map information. We only record source map information for a file in the
// crate that 'owns' it, so deserializing a Span may require us to look at
// a transitive dependency.
//
// When we encode a foreign span, we adjust its 'lo' and 'high' values
// to be based on the *foreign* crate (e.g. crate C), not the crate
// we are writing metadata for (e.g. crate B). This allows us to
// treat the 'local' and 'foreign' cases almost identically during deserialization:
// we can call `imported_source_files` for the proper crate, and binary search
// through the returned slice using our span.
let imported_source_files = if tag == TAG_VALID_SPAN_LOCAL {
decoder.cdata().imported_source_files(sess)
} else {
// When we encode a proc-macro crate, all `Span`s should be encoded
// with `TAG_VALID_SPAN_LOCAL`
if decoder.cdata().root.is_proc_macro_crate() {
// Decode `CrateNum` as u32 - using `CrateNum::decode` will ICE
// since we don't have `cnum_map` populated.
let cnum = u32::decode(decoder);
panic!(
"Decoding of crate {:?} tried to access proc-macro dep {:?}",
decoder.cdata().root.name,
cnum
);
}
// tag is TAG_VALID_SPAN_FOREIGN, checked by `debug_assert` above
let cnum = CrateNum::decode(decoder);
debug!(
"SpecializedDecoder<Span>::specialized_decode: loading source files from cnum {:?}",
cnum
);
// Decoding 'foreign' spans should be rare enough that it's
// not worth it to maintain a per-CrateNum cache for `last_source_file_index`.
// We just set it to 0, to ensure that we don't try to access something out
// of bounds for our initial 'guess'
decoder.last_source_file_index = 0;
let foreign_data = decoder.cdata().cstore.get_crate_data(cnum);
foreign_data.imported_source_files(sess)
};
let source_file = {
// Optimize for the case that most spans within a translated item
// originate from the same source_file.
let last_source_file = &imported_source_files[decoder.last_source_file_index];
if lo >= last_source_file.original_start_pos && lo <= last_source_file.original_end_pos
{
last_source_file
} else {
let index = imported_source_files
.binary_search_by_key(&lo, |source_file| source_file.original_start_pos)
.unwrap_or_else(|index| index - 1);
// Don't try to cache the index for foreign spans,
// as this would require a map from CrateNums to indices
if tag == TAG_VALID_SPAN_LOCAL {
decoder.last_source_file_index = index;
}
&imported_source_files[index]
}
};
// Make sure our binary search above is correct.
debug_assert!(
lo >= source_file.original_start_pos && lo <= source_file.original_end_pos,
"Bad binary search: lo={:?} source_file.original_start_pos={:?} source_file.original_end_pos={:?}",
lo,
source_file.original_start_pos,
source_file.original_end_pos
);
// Make sure we correctly filtered out invalid spans during encoding
debug_assert!(
hi >= source_file.original_start_pos && hi <= source_file.original_end_pos,
"Bad binary search: hi={:?} source_file.original_start_pos={:?} source_file.original_end_pos={:?}",
hi,
source_file.original_start_pos,
source_file.original_end_pos
);
let lo =
(lo + source_file.translated_source_file.start_pos) - source_file.original_start_pos;
let hi =
(hi + source_file.translated_source_file.start_pos) - source_file.original_start_pos;
// Do not try to decode parent for foreign spans.
Span::new(lo, hi, ctxt, None)
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for &'tcx [ty::abstract_const::Node<'tcx>] {
fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Self {
ty::codec::RefDecodable::decode(d)
}
}
impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for &'tcx [(ty::Predicate<'tcx>, Span)] {
fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Self {
ty::codec::RefDecodable::decode(d)
}
}
impl<'a, 'tcx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyValue<T> {
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
decoder.read_lazy()
}
}
impl<'a, 'tcx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyArray<T> {
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
let len = decoder.read_usize();
if len == 0 { LazyArray::empty() } else { decoder.read_lazy_array(len) }
}
}
impl<'a, 'tcx, I: Idx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyTable<I, T> {
fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
let len = decoder.read_usize();
decoder.read_lazy_table(len)
}
}
implement_ty_decoder!(DecodeContext<'a, 'tcx>);
impl MetadataBlob {
pub(crate) fn new(metadata_ref: MetadataRef) -> MetadataBlob {
MetadataBlob(Lrc::new(metadata_ref))
}
pub(crate) fn is_compatible(&self) -> bool {
self.blob().starts_with(METADATA_HEADER)
}
pub(crate) fn get_rustc_version(&self) -> String {
LazyValue::<String>::from_position(NonZeroUsize::new(METADATA_HEADER.len() + 4).unwrap())
.decode(self)
}
pub(crate) fn get_root(&self) -> CrateRoot {
let slice = &self.blob()[..];
let offset = METADATA_HEADER.len();
let pos = (((slice[offset + 0] as u32) << 24)
| ((slice[offset + 1] as u32) << 16)
| ((slice[offset + 2] as u32) << 8)
| ((slice[offset + 3] as u32) << 0)) as usize;
LazyValue::<CrateRoot>::from_position(NonZeroUsize::new(pos).unwrap()).decode(self)
}
pub(crate) fn list_crate_metadata(&self, out: &mut dyn io::Write) -> io::Result<()> {
let root = self.get_root();
writeln!(out, "Crate info:")?;
writeln!(out, "name {}{}", root.name, root.extra_filename)?;
writeln!(out, "hash {} stable_crate_id {:?}", root.hash, root.stable_crate_id)?;
writeln!(out, "proc_macro {:?}", root.proc_macro_data.is_some())?;
writeln!(out, "=External Dependencies=")?;
for (i, dep) in root.crate_deps.decode(self).enumerate() {
writeln!(
out,
"{} {}{} hash {} host_hash {:?} kind {:?}",
i + 1,
dep.name,
dep.extra_filename,
dep.hash,
dep.host_hash,
dep.kind
)?;
}
write!(out, "\n")?;
Ok(())
}
}
impl CrateRoot {
pub(crate) fn is_proc_macro_crate(&self) -> bool {
self.proc_macro_data.is_some()
}
pub(crate) fn name(&self) -> Symbol {
self.name
}
pub(crate) fn hash(&self) -> Svh {
self.hash
}
pub(crate) fn stable_crate_id(&self) -> StableCrateId {
self.stable_crate_id
}
pub(crate) fn triple(&self) -> &TargetTriple {
&self.triple
}
pub(crate) fn decode_crate_deps<'a>(
&self,
metadata: &'a MetadataBlob,
) -> impl ExactSizeIterator<Item = CrateDep> + Captures<'a> {
self.crate_deps.decode(metadata)
}
}
impl<'a, 'tcx> CrateMetadataRef<'a> {
fn raw_proc_macro(self, id: DefIndex) -> &'a ProcMacro {
// DefIndex's in root.proc_macro_data have a one-to-one correspondence
// with items in 'raw_proc_macros'.
let pos = self
.root
.proc_macro_data
.as_ref()
.unwrap()
.macros
.decode(self)
.position(|i| i == id)
.unwrap();
&self.raw_proc_macros.unwrap()[pos]
}
fn opt_item_name(self, item_index: DefIndex) -> Option<Symbol> {
self.def_key(item_index).disambiguated_data.data.get_opt_name()
}
fn item_name(self, item_index: DefIndex) -> Symbol {
self.opt_item_name(item_index).expect("no encoded ident for item")
}
fn opt_item_ident(self, item_index: DefIndex, sess: &Session) -> Option<Ident> {
let name = self.opt_item_name(item_index)?;
let span =
self.root.tables.def_ident_span.get(self, item_index).unwrap().decode((self, sess));
Some(Ident::new(name, span))
}
fn item_ident(self, item_index: DefIndex, sess: &Session) -> Ident {
self.opt_item_ident(item_index, sess).expect("no encoded ident for item")
}
fn maybe_kind(self, item_id: DefIndex) -> Option<EntryKind> {
self.root.tables.kind.get(self, item_id).map(|k| k.decode(self))
}
#[inline]
pub(super) fn map_encoded_cnum_to_current(self, cnum: CrateNum) -> CrateNum {
if cnum == LOCAL_CRATE { self.cnum } else { self.cnum_map[cnum] }
}
fn kind(self, item_id: DefIndex) -> EntryKind {
self.maybe_kind(item_id).unwrap_or_else(|| {
bug!(
"CrateMetadata::kind({:?}): id not found, in crate {:?} with number {}",
item_id,
self.root.name,
self.cnum,
)
})
}
fn def_kind(self, item_id: DefIndex) -> DefKind {
self.root.tables.opt_def_kind.get(self, item_id).unwrap_or_else(|| {
bug!(
"CrateMetadata::def_kind({:?}): id not found, in crate {:?} with number {}",
item_id,
self.root.name,
self.cnum,
)
})
}
fn get_span(self, index: DefIndex, sess: &Session) -> Span {
self.root
.tables
.def_span
.get(self, index)
.unwrap_or_else(|| panic!("Missing span for {:?}", index))
.decode((self, sess))
}
fn load_proc_macro(self, id: DefIndex, sess: &Session) -> SyntaxExtension {
let (name, kind, helper_attrs) = match *self.raw_proc_macro(id) {
ProcMacro::CustomDerive { trait_name, attributes, client } => {
let helper_attrs =
attributes.iter().cloned().map(Symbol::intern).collect::<Vec<_>>();
(
trait_name,
SyntaxExtensionKind::Derive(Box::new(DeriveProcMacro { client })),
helper_attrs,
)
}
ProcMacro::Attr { name, client } => {
(name, SyntaxExtensionKind::Attr(Box::new(AttrProcMacro { client })), Vec::new())
}
ProcMacro::Bang { name, client } => {
(name, SyntaxExtensionKind::Bang(Box::new(BangProcMacro { client })), Vec::new())
}
};
let attrs: Vec<_> = self.get_item_attrs(id, sess).collect();
SyntaxExtension::new(
sess,
kind,
self.get_span(id, sess),
helper_attrs,
self.root.edition,
Symbol::intern(name),
&attrs,
)
}
fn get_variant(self, kind: &EntryKind, index: DefIndex, parent_did: DefId) -> ty::VariantDef {
let data = match kind {
EntryKind::Variant(data) | EntryKind::Struct(data) | EntryKind::Union(data) => {
data.decode(self)
}
_ => bug!(),
};
let adt_kind = match kind {
EntryKind::Variant(_) => ty::AdtKind::Enum,
EntryKind::Struct(..) => ty::AdtKind::Struct,
EntryKind::Union(..) => ty::AdtKind::Union,
_ => bug!(),
};
let variant_did =
if adt_kind == ty::AdtKind::Enum { Some(self.local_def_id(index)) } else { None };
let ctor_did = data.ctor.map(|index| self.local_def_id(index));
ty::VariantDef::new(
self.item_name(index),
variant_did,
ctor_did,
data.discr,
self.root
.tables
.children
.get(self, index)
.unwrap_or_else(LazyArray::empty)
.decode(self)
.map(|index| ty::FieldDef {
did: self.local_def_id(index),
name: self.item_name(index),
vis: self.get_visibility(index),
})
.collect(),
data.ctor_kind,
adt_kind,
parent_did,
false,
data.is_non_exhaustive,
)
}
fn get_adt_def(self, item_id: DefIndex, tcx: TyCtxt<'tcx>) -> ty::AdtDef<'tcx> {
let kind = self.kind(item_id);
let did = self.local_def_id(item_id);
let adt_kind = match kind {
EntryKind::Enum => ty::AdtKind::Enum,
EntryKind::Struct(_) => ty::AdtKind::Struct,
EntryKind::Union(_) => ty::AdtKind::Union,
_ => bug!("get_adt_def called on a non-ADT {:?}", did),
};
let repr = self.root.tables.repr_options.get(self, item_id).unwrap().decode(self);
let variants = if let ty::AdtKind::Enum = adt_kind {
self.root
.tables
.children
.get(self, item_id)
.unwrap_or_else(LazyArray::empty)
.decode(self)
.map(|index| self.get_variant(&self.kind(index), index, did))
.collect()
} else {
std::iter::once(self.get_variant(&kind, item_id, did)).collect()
};
tcx.alloc_adt_def(did, adt_kind, variants, repr)
}
fn get_generics(self, item_id: DefIndex, sess: &Session) -> ty::Generics {
self.root.tables.generics_of.get(self, item_id).unwrap().decode((self, sess))
}
fn get_visibility(self, id: DefIndex) -> ty::Visibility {
self.root.tables.visibility.get(self, id).unwrap().decode(self)
}
fn get_trait_item_def_id(self, id: DefIndex) -> Option<DefId> {
self.root.tables.trait_item_def_id.get(self, id).map(|d| d.decode_from_cdata(self))
}
fn get_expn_that_defined(self, id: DefIndex, sess: &Session) -> ExpnId {
self.root.tables.expn_that_defined.get(self, id).unwrap().decode((self, sess))
}
fn get_debugger_visualizers(self) -> Vec<rustc_span::DebuggerVisualizerFile> {
self.root.debugger_visualizers.decode(self).collect::<Vec<_>>()
}
/// Iterates over all the stability attributes in the given crate.
fn get_lib_features(self, tcx: TyCtxt<'tcx>) -> &'tcx [(Symbol, Option<Symbol>)] {
tcx.arena.alloc_from_iter(self.root.lib_features.decode(self))
}
/// Iterates over the stability implications in the given crate (when a `#[unstable]` attribute
/// has an `implied_by` meta item, then the mapping from the implied feature to the actual
/// feature is a stability implication).
fn get_stability_implications(self, tcx: TyCtxt<'tcx>) -> &'tcx [(Symbol, Symbol)] {
tcx.arena.alloc_from_iter(self.root.stability_implications.decode(self))
}
/// Iterates over the language items in the given crate.
fn get_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, usize)] {
tcx.arena.alloc_from_iter(
self.root
.lang_items
.decode(self)
.map(move |(def_index, index)| (self.local_def_id(def_index), index)),
)
}
/// Iterates over the diagnostic items in the given crate.
fn get_diagnostic_items(self) -> DiagnosticItems {
let mut id_to_name = FxHashMap::default();
let name_to_id = self
.root
.diagnostic_items
.decode(self)
.map(|(name, def_index)| {
let id = self.local_def_id(def_index);
id_to_name.insert(id, name);
(name, id)
})
.collect();
DiagnosticItems { id_to_name, name_to_id }
}
/// Iterates over all named children of the given module,
/// including both proper items and reexports.
/// Module here is understood in name resolution sense - it can be a `mod` item,
/// or a crate root, or an enum, or a trait.
fn for_each_module_child(
self,
id: DefIndex,
mut callback: impl FnMut(ModChild),
sess: &Session,
) {
if let Some(data) = &self.root.proc_macro_data {
// If we are loading as a proc macro, we want to return
// the view of this crate as a proc macro crate.
if id == CRATE_DEF_INDEX {
for def_index in data.macros.decode(self) {
let raw_macro = self.raw_proc_macro(def_index);
let res = Res::Def(
DefKind::Macro(macro_kind(raw_macro)),
self.local_def_id(def_index),
);
let ident = self.item_ident(def_index, sess);
callback(ModChild {
ident,
res,
vis: ty::Visibility::Public,
span: ident.span,
macro_rules: false,
});
}
}
return;
}
// Iterate over all children.
if let Some(children) = self.root.tables.children.get(self, id) {
for child_index in children.decode((self, sess)) {
let ident = self.item_ident(child_index, sess);
let kind = self.def_kind(child_index);
let def_id = self.local_def_id(child_index);
let res = Res::Def(kind, def_id);
let vis = self.get_visibility(child_index);
let span = self.get_span(child_index, sess);
let macro_rules = match kind {
DefKind::Macro(..) => match self.kind(child_index) {
EntryKind::MacroDef(_, macro_rules) => macro_rules,
_ => unreachable!(),
},
_ => false,
};
callback(ModChild { ident, res, vis, span, macro_rules });
// For non-re-export structs and variants add their constructors to children.
// Re-export lists automatically contain constructors when necessary.
match kind {
DefKind::Struct => {
if let Some((ctor_def_id, ctor_kind)) =
self.get_ctor_def_id_and_kind(child_index)
{
let ctor_res =
Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id);
let vis = self.get_visibility(ctor_def_id.index);
callback(ModChild {
ident,
res: ctor_res,
vis,
span,
macro_rules: false,
});
}
}
DefKind::Variant => {
// Braced variants, unlike structs, generate unusable names in
// value namespace, they are reserved for possible future use.
// It's ok to use the variant's id as a ctor id since an
// error will be reported on any use of such resolution anyway.
let (ctor_def_id, ctor_kind) = self
.get_ctor_def_id_and_kind(child_index)
.unwrap_or((def_id, CtorKind::Fictive));
let ctor_res =
Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
let mut vis = self.get_visibility(ctor_def_id.index);
if ctor_def_id == def_id && vis.is_public() {
// For non-exhaustive variants lower the constructor visibility to
// within the crate. We only need this for fictive constructors,
// for other constructors correct visibilities
// were already encoded in metadata.
let mut attrs = self.get_item_attrs(def_id.index, sess);
if attrs.any(|item| item.has_name(sym::non_exhaustive)) {
let crate_def_id = self.local_def_id(CRATE_DEF_INDEX);
vis = ty::Visibility::Restricted(crate_def_id);
}
}
callback(ModChild { ident, res: ctor_res, vis, span, macro_rules: false });
}
_ => {}
}
}
}
match self.kind(id) {
EntryKind::Mod(exports) => {
for exp in exports.decode((self, sess)) {
callback(exp);
}
}
EntryKind::Enum | EntryKind::Trait => {}
_ => bug!("`for_each_module_child` is called on a non-module: {:?}", self.def_kind(id)),
}
}
fn is_ctfe_mir_available(self, id: DefIndex) -> bool {
self.root.tables.mir_for_ctfe.get(self, id).is_some()
}
fn is_item_mir_available(self, id: DefIndex) -> bool {
self.root.tables.optimized_mir.get(self, id).is_some()
}
fn module_expansion(self, id: DefIndex, sess: &Session) -> ExpnId {
match self.kind(id) {
EntryKind::Mod(_) | EntryKind::Enum | EntryKind::Trait => {
self.get_expn_that_defined(id, sess)
}
_ => panic!("Expected module, found {:?}", self.local_def_id(id)),
}
}
fn get_fn_has_self_parameter(self, id: DefIndex) -> bool {
match self.kind(id) {
EntryKind::AssocFn { has_self, .. } => has_self,
_ => false,
}
}
fn get_associated_item_def_ids(
self,
id: DefIndex,
sess: &'a Session,
) -> impl Iterator<Item = DefId> + 'a {
self.root
.tables
.children
.get(self, id)
.unwrap_or_else(LazyArray::empty)
.decode((self, sess))
.map(move |child_index| self.local_def_id(child_index))
}
fn get_associated_item(self, id: DefIndex) -> ty::AssocItem {
let name = self.item_name(id);
let (kind, container, has_self) = match self.kind(id) {
EntryKind::AssocConst(container) => (ty::AssocKind::Const, container, false),
EntryKind::AssocFn { container, has_self } => (ty::AssocKind::Fn, container, has_self),
EntryKind::AssocType(container) => (ty::AssocKind::Type, container, false),
_ => bug!("cannot get associated-item of `{:?}`", id),
};
ty::AssocItem {
name,
kind,
def_id: self.local_def_id(id),
trait_item_def_id: self.get_trait_item_def_id(id),
container,
fn_has_self_parameter: has_self,
}
}
fn get_ctor_def_id_and_kind(self, node_id: DefIndex) -> Option<(DefId, CtorKind)> {
match self.kind(node_id) {
EntryKind::Struct(data) | EntryKind::Variant(data) => {
let vdata = data.decode(self);
vdata.ctor.map(|index| (self.local_def_id(index), vdata.ctor_kind))
}
_ => None,
}
}
fn get_item_attrs(
self,
id: DefIndex,
sess: &'a Session,
) -> impl Iterator<Item = ast::Attribute> + 'a {
self.root
.tables
.attributes
.get(self, id)
.unwrap_or_else(|| {
// Structure and variant constructors don't have any attributes encoded for them,
// but we assume that someone passing a constructor ID actually wants to look at
// the attributes on the corresponding struct or variant.
let def_key = self.def_key(id);
assert_eq!(def_key.disambiguated_data.data, DefPathData::Ctor);
let parent_id = def_key.parent.expect("no parent for a constructor");
self.root
.tables
.attributes
.get(self, parent_id)
.expect("no encoded attributes for a structure or variant")
})
.decode((self, sess))
}
fn get_struct_field_names(
self,
id: DefIndex,
sess: &'a Session,
) -> impl Iterator<Item = Spanned<Symbol>> + 'a {
self.root
.tables
.children
.get(self, id)
.unwrap_or_else(LazyArray::empty)
.decode(self)
.map(move |index| respan(self.get_span(index, sess), self.item_name(index)))
}
fn get_struct_field_visibilities(self, id: DefIndex) -> impl Iterator<Item = Visibility> + 'a {
self.root
.tables
.children
.get(self, id)
.unwrap_or_else(LazyArray::empty)
.decode(self)
.map(move |field_index| self.get_visibility(field_index))
}
fn get_inherent_implementations_for_type(
self,
tcx: TyCtxt<'tcx>,
id: DefIndex,
) -> &'tcx [DefId] {
tcx.arena.alloc_from_iter(
self.root
.tables
.inherent_impls
.get(self, id)
.unwrap_or_else(LazyArray::empty)
.decode(self)
.map(|index| self.local_def_id(index)),
)
}
/// Decodes all inherent impls in the crate (for rustdoc).
fn get_inherent_impls(self) -> impl Iterator<Item = (DefId, DefId)> + 'a {
(0..self.root.tables.inherent_impls.size()).flat_map(move |i| {
let ty_index = DefIndex::from_usize(i);
let ty_def_id = self.local_def_id(ty_index);
self.root
.tables
.inherent_impls
.get(self, ty_index)
.unwrap_or_else(LazyArray::empty)
.decode(self)
.map(move |impl_index| (ty_def_id, self.local_def_id(impl_index)))
})
}
/// Decodes all traits in the crate (for rustdoc and rustc diagnostics).
fn get_traits(self) -> impl Iterator<Item = DefId> + 'a {
self.root.traits.decode(self).map(move |index| self.local_def_id(index))
}
/// Decodes all trait impls in the crate (for rustdoc).
fn get_trait_impls(self) -> impl Iterator<Item = (DefId, DefId, Option<SimplifiedType>)> + 'a {
self.cdata.trait_impls.iter().flat_map(move |(&(trait_cnum_raw, trait_index), impls)| {
let trait_def_id = DefId {
krate: self.cnum_map[CrateNum::from_u32(trait_cnum_raw)],
index: trait_index,
};
impls.decode(self).map(move |(impl_index, simplified_self_ty)| {
(trait_def_id, self.local_def_id(impl_index), simplified_self_ty)
})
})
}
fn get_all_incoherent_impls(self) -> impl Iterator<Item = DefId> + 'a {
self.cdata
.incoherent_impls
.values()
.flat_map(move |impls| impls.decode(self).map(move |idx| self.local_def_id(idx)))
}
fn get_incoherent_impls(self, tcx: TyCtxt<'tcx>, simp: SimplifiedType) -> &'tcx [DefId] {
if let Some(impls) = self.cdata.incoherent_impls.get(&simp) {
tcx.arena.alloc_from_iter(impls.decode(self).map(|idx| self.local_def_id(idx)))
} else {
&[]
}
}
fn get_implementations_of_trait(
self,
tcx: TyCtxt<'tcx>,
trait_def_id: DefId,
) -> &'tcx [(DefId, Option<SimplifiedType>)] {
if self.trait_impls.is_empty() {
return &[];
}
// Do a reverse lookup beforehand to avoid touching the crate_num
// hash map in the loop below.
let key = match self.reverse_translate_def_id(trait_def_id) {
Some(def_id) => (def_id.krate.as_u32(), def_id.index),
None => return &[],
};
if let Some(impls) = self.trait_impls.get(&key) {
tcx.arena.alloc_from_iter(
impls
.decode(self)
.map(|(idx, simplified_self_ty)| (self.local_def_id(idx), simplified_self_ty)),
)
} else {
&[]
}
}
fn get_native_libraries(self, sess: &'a Session) -> impl Iterator<Item = NativeLib> + 'a {
self.root.native_libraries.decode((self, sess))
}
fn get_proc_macro_quoted_span(self, index: usize, sess: &Session) -> Span {
self.root
.tables
.proc_macro_quoted_spans
.get(self, index)
.unwrap_or_else(|| panic!("Missing proc macro quoted span: {:?}", index))
.decode((self, sess))
}
fn get_foreign_modules(self, sess: &'a Session) -> impl Iterator<Item = ForeignModule> + '_ {
self.root.foreign_modules.decode((self, sess))
}
fn get_dylib_dependency_formats(
self,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(CrateNum, LinkagePreference)] {
tcx.arena.alloc_from_iter(
self.root.dylib_dependency_formats.decode(self).enumerate().flat_map(|(i, link)| {
let cnum = CrateNum::new(i + 1);
link.map(|link| (self.cnum_map[cnum], link))
}),
)
}
fn get_missing_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [lang_items::LangItem] {
tcx.arena.alloc_from_iter(self.root.lang_items_missing.decode(self))
}
fn exported_symbols(
self,
tcx: TyCtxt<'tcx>,
) -> &'tcx [(ExportedSymbol<'tcx>, SymbolExportInfo)] {
tcx.arena.alloc_from_iter(self.root.exported_symbols.decode((self, tcx)))
}
fn get_macro(self, id: DefIndex, sess: &Session) -> ast::MacroDef {
match self.kind(id) {
EntryKind::MacroDef(mac_args, macro_rules) => {
ast::MacroDef { body: P(mac_args.decode((self, sess))), macro_rules }
}
_ => bug!(),
}
}
fn is_foreign_item(self, id: DefIndex) -> bool {
match self.kind(id) {
EntryKind::ForeignStatic | EntryKind::ForeignFn => true,
_ => false,
}
}
#[inline]
fn def_key(self, index: DefIndex) -> DefKey {
*self
.def_key_cache
.lock()
.entry(index)
.or_insert_with(|| self.root.tables.def_keys.get(self, index).unwrap().decode(self))
}
// Returns the path leading to the thing with this `id`.
fn def_path(self, id: DefIndex) -> DefPath {
debug!("def_path(cnum={:?}, id={:?})", self.cnum, id);
DefPath::make(self.cnum, id, |parent| self.def_key(parent))
}
fn def_path_hash_unlocked(
self,
index: DefIndex,
def_path_hashes: &mut FxHashMap<DefIndex, DefPathHash>,
) -> DefPathHash {
*def_path_hashes
.entry(index)
.or_insert_with(|| self.root.tables.def_path_hashes.get(self, index).unwrap())
}
#[inline]
fn def_path_hash(self, index: DefIndex) -> DefPathHash {
let mut def_path_hashes = self.def_path_hash_cache.lock();
self.def_path_hash_unlocked(index, &mut def_path_hashes)
}
#[inline]
fn def_path_hash_to_def_index(self, hash: DefPathHash) -> DefIndex {
self.def_path_hash_map.def_path_hash_to_def_index(&hash)
}
fn expn_hash_to_expn_id(self, sess: &Session, index_guess: u32, hash: ExpnHash) -> ExpnId {
debug_assert_eq!(ExpnId::from_hash(hash), None);
let index_guess = ExpnIndex::from_u32(index_guess);
let old_hash = self.root.expn_hashes.get(self, index_guess).map(|lazy| lazy.decode(self));
let index = if old_hash == Some(hash) {
// Fast path: the expn and its index is unchanged from the
// previous compilation session. There is no need to decode anything
// else.
index_guess
} else {
// Slow path: We need to find out the new `DefIndex` of the provided
// `DefPathHash`, if its still exists. This requires decoding every `DefPathHash`
// stored in this crate.
let map = self.cdata.expn_hash_map.get_or_init(|| {
let end_id = self.root.expn_hashes.size() as u32;
let mut map =
UnhashMap::with_capacity_and_hasher(end_id as usize, Default::default());
for i in 0..end_id {
let i = ExpnIndex::from_u32(i);
if let Some(hash) = self.root.expn_hashes.get(self, i) {
map.insert(hash.decode(self), i);
}
}
map
});
map[&hash]
};
let data = self.root.expn_data.get(self, index).unwrap().decode((self, sess));
rustc_span::hygiene::register_expn_id(self.cnum, index, data, hash)
}
/// Imports the source_map from an external crate into the source_map of the crate
/// currently being compiled (the "local crate").
///
/// The import algorithm works analogous to how AST items are inlined from an
/// external crate's metadata:
/// For every SourceFile in the external source_map an 'inline' copy is created in the
/// local source_map. The correspondence relation between external and local
/// SourceFiles is recorded in the `ImportedSourceFile` objects returned from this
/// function. When an item from an external crate is later inlined into this
/// crate, this correspondence information is used to translate the span
/// information of the inlined item so that it refers the correct positions in
/// the local source_map (see `<decoder::DecodeContext as SpecializedDecoder<Span>>`).
///
/// The import algorithm in the function below will reuse SourceFiles already
/// existing in the local source_map. For example, even if the SourceFile of some
/// source file of libstd gets imported many times, there will only ever be
/// one SourceFile object for the corresponding file in the local source_map.
///
/// Note that imported SourceFiles do not actually contain the source code of the
/// file they represent, just information about length, line breaks, and
/// multibyte characters. This information is enough to generate valid debuginfo
/// for items inlined from other crates.
///
/// Proc macro crates don't currently export spans, so this function does not have
/// to work for them.
fn imported_source_files(self, sess: &Session) -> &'a [ImportedSourceFile] {
fn filter<'a>(sess: &Session, path: Option<&'a Path>) -> Option<&'a Path> {
path.filter(|_| {
// Only spend time on further checks if we have what to translate *to*.
sess.opts.real_rust_source_base_dir.is_some()
// Some tests need the translation to be always skipped.
&& sess.opts.unstable_opts.translate_remapped_path_to_local_path
})
.filter(|virtual_dir| {
// Don't translate away `/rustc/$hash` if we're still remapping to it,
// since that means we're still building `std`/`rustc` that need it,
// and we don't want the real path to leak into codegen/debuginfo.
!sess.opts.remap_path_prefix.iter().any(|(_from, to)| to == virtual_dir)
})
}
// Translate the virtual `/rustc/$hash` prefix back to a real directory
// that should hold actual sources, where possible.
//
// NOTE: if you update this, you might need to also update bootstrap's code for generating
// the `rust-src` component in `Src::run` in `src/bootstrap/dist.rs`.
let virtual_rust_source_base_dir = [
filter(sess, option_env!("CFG_VIRTUAL_RUST_SOURCE_BASE_DIR").map(Path::new)),
filter(sess, sess.opts.unstable_opts.simulate_remapped_rust_src_base.as_deref()),
];
let try_to_translate_virtual_to_real = |name: &mut rustc_span::FileName| {
debug!(
"try_to_translate_virtual_to_real(name={:?}): \
virtual_rust_source_base_dir={:?}, real_rust_source_base_dir={:?}",
name, virtual_rust_source_base_dir, sess.opts.real_rust_source_base_dir,
);
for virtual_dir in virtual_rust_source_base_dir.iter().flatten() {
if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
if let rustc_span::FileName::Real(old_name) = name {
if let rustc_span::RealFileName::Remapped { local_path: _, virtual_name } =
old_name
{
if let Ok(rest) = virtual_name.strip_prefix(virtual_dir) {
let virtual_name = virtual_name.clone();
// The std library crates are in
// `$sysroot/lib/rustlib/src/rust/library`, whereas other crates
// may be in `$sysroot/lib/rustlib/src/rust/` directly. So we
// detect crates from the std libs and handle them specially.
const STD_LIBS: &[&str] = &[
"core",
"alloc",
"std",
"test",
"term",
"unwind",
"proc_macro",
"panic_abort",
"panic_unwind",
"profiler_builtins",
"rtstartup",
"rustc-std-workspace-core",
"rustc-std-workspace-alloc",
"rustc-std-workspace-std",
"backtrace",
];
let is_std_lib = STD_LIBS.iter().any(|l| rest.starts_with(l));
let new_path = if is_std_lib {
real_dir.join("library").join(rest)
} else {
real_dir.join(rest)
};
debug!(
"try_to_translate_virtual_to_real: `{}` -> `{}`",
virtual_name.display(),
new_path.display(),
);
let new_name = rustc_span::RealFileName::Remapped {
local_path: Some(new_path),
virtual_name,
};
*old_name = new_name;
}
}
}
}
}
};
self.cdata.source_map_import_info.get_or_init(|| {
let external_source_map = self.root.source_map.decode(self);
external_source_map
.map(|source_file_to_import| {
// We can't reuse an existing SourceFile, so allocate a new one
// containing the information we need.
let rustc_span::SourceFile {
mut name,
src_hash,
start_pos,
end_pos,
lines,
multibyte_chars,
non_narrow_chars,
normalized_pos,
name_hash,
..
} = source_file_to_import;
// If this file is under $sysroot/lib/rustlib/src/ but has not been remapped
// during rust bootstrapping by `remap-debuginfo = true`, and the user
// wish to simulate that behaviour by -Z simulate-remapped-rust-src-base,
// then we change `name` to a similar state as if the rust was bootstrapped
// with `remap-debuginfo = true`.
// This is useful for testing so that tests about the effects of
// `try_to_translate_virtual_to_real` don't have to worry about how the
// compiler is bootstrapped.
if let Some(virtual_dir) =
&sess.opts.unstable_opts.simulate_remapped_rust_src_base
{
if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
if let rustc_span::FileName::Real(ref mut old_name) = name {
if let rustc_span::RealFileName::LocalPath(local) = old_name {
if let Ok(rest) = local.strip_prefix(real_dir) {
*old_name = rustc_span::RealFileName::Remapped {
local_path: None,
virtual_name: virtual_dir.join(rest),
};
}
}
}
}
}
// If this file's path has been remapped to `/rustc/$hash`,
// we might be able to reverse that (also see comments above,
// on `try_to_translate_virtual_to_real`).
try_to_translate_virtual_to_real(&mut name);
let source_length = (end_pos - start_pos).to_usize();
let local_version = sess.source_map().new_imported_source_file(
name,
src_hash,
name_hash,
source_length,
self.cnum,
lines,
multibyte_chars,
non_narrow_chars,
normalized_pos,
start_pos,
end_pos,
);
debug!(
"CrateMetaData::imported_source_files alloc \
source_file {:?} original (start_pos {:?} end_pos {:?}) \
translated (start_pos {:?} end_pos {:?})",
local_version.name,
start_pos,
end_pos,
local_version.start_pos,
local_version.end_pos
);
ImportedSourceFile {
original_start_pos: start_pos,
original_end_pos: end_pos,
translated_source_file: local_version,
}
})
.collect()
})
}
fn get_generator_diagnostic_data(
self,
tcx: TyCtxt<'tcx>,
id: DefIndex,
) -> Option<GeneratorDiagnosticData<'tcx>> {
self.root
.tables
.generator_diagnostic_data
.get(self, id)
.map(|param| param.decode((self, tcx)))
.map(|generator_data| GeneratorDiagnosticData {
generator_interior_types: generator_data.generator_interior_types,
hir_owner: generator_data.hir_owner,
nodes_types: generator_data.nodes_types,
adjustments: generator_data.adjustments,
})
}
fn get_may_have_doc_links(self, index: DefIndex) -> bool {
self.root.tables.may_have_doc_links.get(self, index).is_some()
}
fn get_is_intrinsic(self, index: DefIndex) -> bool {
self.root.tables.is_intrinsic.get(self, index).is_some()
}
}
impl CrateMetadata {
pub(crate) fn new(
sess: &Session,
cstore: &CStore,
blob: MetadataBlob,
root: CrateRoot,
raw_proc_macros: Option<&'static [ProcMacro]>,
cnum: CrateNum,
cnum_map: CrateNumMap,
dep_kind: CrateDepKind,
source: CrateSource,
private_dep: bool,
host_hash: Option<Svh>,
) -> CrateMetadata {
let trait_impls = root
.impls
.decode((&blob, sess))
.map(|trait_impls| (trait_impls.trait_id, trait_impls.impls))
.collect();
let alloc_decoding_state =
AllocDecodingState::new(root.interpret_alloc_index.decode(&blob).collect());
let dependencies = Lock::new(cnum_map.iter().cloned().collect());
// Pre-decode the DefPathHash->DefIndex table. This is a cheap operation
// that does not copy any data. It just does some data verification.
let def_path_hash_map = root.def_path_hash_map.decode(&blob);
let mut cdata = CrateMetadata {
blob,
root,
trait_impls,
incoherent_impls: Default::default(),
raw_proc_macros,
source_map_import_info: OnceCell::new(),
def_path_hash_map,
expn_hash_map: Default::default(),
alloc_decoding_state,
cnum,
cnum_map,
dependencies,
dep_kind: Lock::new(dep_kind),
source: Lrc::new(source),
private_dep,
host_hash,
extern_crate: Lock::new(None),
hygiene_context: Default::default(),
def_key_cache: Default::default(),
def_path_hash_cache: Default::default(),
};
// Need `CrateMetadataRef` to decode `DefId`s in simplified types.
cdata.incoherent_impls = cdata
.root
.incoherent_impls
.decode(CrateMetadataRef { cdata: &cdata, cstore })
.map(|incoherent_impls| (incoherent_impls.self_ty, incoherent_impls.impls))
.collect();
cdata
}
pub(crate) fn dependencies(&self) -> LockGuard<'_, Vec<CrateNum>> {
self.dependencies.borrow()
}
pub(crate) fn add_dependency(&self, cnum: CrateNum) {
self.dependencies.borrow_mut().push(cnum);
}
pub(crate) fn update_extern_crate(&self, new_extern_crate: ExternCrate) -> bool {
let mut extern_crate = self.extern_crate.borrow_mut();
let update = Some(new_extern_crate.rank()) > extern_crate.as_ref().map(ExternCrate::rank);
if update {
*extern_crate = Some(new_extern_crate);
}
update
}
pub(crate) fn source(&self) -> &CrateSource {
&*self.source
}
pub(crate) fn dep_kind(&self) -> CrateDepKind {
*self.dep_kind.lock()
}
pub(crate) fn update_dep_kind(&self, f: impl FnOnce(CrateDepKind) -> CrateDepKind) {
self.dep_kind.with_lock(|dep_kind| *dep_kind = f(*dep_kind))
}
pub(crate) fn required_panic_strategy(&self) -> Option<PanicStrategy> {
self.root.required_panic_strategy
}
pub(crate) fn needs_panic_runtime(&self) -> bool {
self.root.needs_panic_runtime
}
pub(crate) fn is_panic_runtime(&self) -> bool {
self.root.panic_runtime
}
pub(crate) fn is_profiler_runtime(&self) -> bool {
self.root.profiler_runtime
}
pub(crate) fn needs_allocator(&self) -> bool {
self.root.needs_allocator
}
pub(crate) fn has_global_allocator(&self) -> bool {
self.root.has_global_allocator
}
pub(crate) fn has_default_lib_allocator(&self) -> bool {
self.root.has_default_lib_allocator
}
pub(crate) fn is_proc_macro_crate(&self) -> bool {
self.root.is_proc_macro_crate()
}
pub(crate) fn name(&self) -> Symbol {
self.root.name
}
pub(crate) fn stable_crate_id(&self) -> StableCrateId {
self.root.stable_crate_id
}
pub(crate) fn hash(&self) -> Svh {
self.root.hash
}
fn num_def_ids(&self) -> usize {
self.root.tables.def_keys.size()
}
fn local_def_id(&self, index: DefIndex) -> DefId {
DefId { krate: self.cnum, index }
}
// Translate a DefId from the current compilation environment to a DefId
// for an external crate.
fn reverse_translate_def_id(&self, did: DefId) -> Option<DefId> {
for (local, &global) in self.cnum_map.iter_enumerated() {
if global == did.krate {
return Some(DefId { krate: local, index: did.index });
}
}
None
}
}
// Cannot be implemented on 'ProcMacro', as libproc_macro
// does not depend on librustc_ast
fn macro_kind(raw: &ProcMacro) -> MacroKind {
match raw {
ProcMacro::CustomDerive { .. } => MacroKind::Derive,
ProcMacro::Attr { .. } => MacroKind::Attr,
ProcMacro::Bang { .. } => MacroKind::Bang,
}
}