Simplify lazy DefPathHash decoding by using an on-disk hash table.
This PR simplifies the logic around mapping `DefPathHash` values encountered during incremental compilation to valid `DefId`s in the current session. It is able to do so by using an on-disk hash table encoding that allows for looking up values directly, i.e. without deserializing the entire table.
The main simplification comes from not having to keep track of `DefPathHashes` being used during the compilation session.
"rustc-std-workspace-core",
]
+[[package]]
+name = "odht"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b18a8d1c919d3e7b5c49708d08ef7d60bc2150a7c3a8244257c54ca3f625010"
+dependencies = [
+ "cfg-if 1.0.0",
+]
+
[[package]]
name = "once_cell"
version = "1.7.2"
name = "rustc_hir"
version = "0.0.0"
dependencies = [
+ "odht",
"rustc_ast",
"rustc_data_structures",
"rustc_feature",
version = "0.0.0"
dependencies = [
"libc",
+ "odht",
"rustc_ast",
"rustc_attr",
"rustc_data_structures",
rustc_ast = { path = "../rustc_ast" }
tracing = "0.1"
smallvec = { version = "1.6.1", features = ["union", "may_dangle"] }
+odht = { version = "0.2.1", features = ["nightly"] }
--- /dev/null
+use rustc_data_structures::fingerprint::Fingerprint;
+use rustc_span::def_id::{DefIndex, DefPathHash};
+
+#[derive(Clone, Default)]
+pub struct Config;
+
+impl odht::Config for Config {
+ type Key = DefPathHash;
+ type Value = DefIndex;
+
+ type EncodedKey = [u8; 16];
+ type EncodedValue = [u8; 4];
+
+ type H = odht::UnHashFn;
+
+ #[inline]
+ fn encode_key(k: &DefPathHash) -> [u8; 16] {
+ k.0.to_le_bytes()
+ }
+
+ #[inline]
+ fn encode_value(v: &DefIndex) -> [u8; 4] {
+ v.as_u32().to_le_bytes()
+ }
+
+ #[inline]
+ fn decode_key(k: &[u8; 16]) -> DefPathHash {
+ DefPathHash(Fingerprint::from_le_bytes(*k))
+ }
+
+ #[inline]
+ fn decode_value(v: &[u8; 4]) -> DefIndex {
+ DefIndex::from_u32(u32::from_le_bytes(*v))
+ }
+}
+
+pub type DefPathHashMap = odht::HashTableOwned<Config>;
pub use crate::def_id::DefPathHash;
use crate::def_id::{CrateNum, DefIndex, LocalDefId, StableCrateId, CRATE_DEF_INDEX, LOCAL_CRATE};
+use crate::def_path_hash_map::DefPathHashMap;
use crate::hir;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::stable_hasher::StableHasher;
-use rustc_data_structures::unhash::UnhashMap;
use rustc_index::vec::IndexVec;
use rustc_span::hygiene::ExpnId;
use rustc_span::symbol::{kw, sym, Symbol};
pub struct DefPathTable {
index_to_key: IndexVec<DefIndex, DefKey>,
def_path_hashes: IndexVec<DefIndex, DefPathHash>,
- def_path_hash_to_index: UnhashMap<DefPathHash, DefIndex>,
+ def_path_hash_to_index: DefPathHashMap,
}
impl DefPathTable {
// Check for hash collisions of DefPathHashes. These should be
// exceedingly rare.
- if let Some(existing) = self.def_path_hash_to_index.insert(def_path_hash, index) {
+ if let Some(existing) = self.def_path_hash_to_index.insert(&def_path_hash, &index) {
let def_path1 = DefPath::make(LOCAL_CRATE, existing, |idx| self.def_key(idx));
let def_path2 = DefPath::make(LOCAL_CRATE, index, |idx| self.def_key(idx));
pub fn enumerated_keys_and_path_hashes(
&self,
- ) -> impl Iterator<Item = (DefIndex, &DefKey, &DefPathHash)> + '_ {
+ ) -> impl Iterator<Item = (DefIndex, &DefKey, &DefPathHash)> + ExactSizeIterator + '_ {
self.index_to_key
.iter_enumerated()
.map(move |(index, key)| (index, key, &self.def_path_hashes[index]))
expansions_that_defined: FxHashMap<LocalDefId, ExpnId>,
def_id_to_span: IndexVec<LocalDefId, Span>,
+
+ /// The [StableCrateId] of the local crate.
+ stable_crate_id: StableCrateId,
}
/// A unique identifier that we can use to lookup a definition
hir_id_to_def_id: Default::default(),
expansions_that_defined: Default::default(),
def_id_to_span,
+ stable_crate_id,
}
}
}
#[inline(always)]
- pub fn local_def_path_hash_to_def_id(&self, hash: DefPathHash) -> Option<LocalDefId> {
+ pub fn local_def_path_hash_to_def_id(&self, hash: DefPathHash) -> LocalDefId {
+ debug_assert!(hash.stable_crate_id() == self.stable_crate_id);
self.table
.def_path_hash_to_index
.get(&hash)
- .map(|&local_def_index| LocalDefId { local_def_index })
+ .map(|local_def_index| LocalDefId { local_def_index })
+ .unwrap()
+ }
+
+ pub fn def_path_hash_to_def_index_map(&self) -> &DefPathHashMap {
+ &self.table.def_path_hash_to_index
}
}
mod arena;
pub mod def;
+pub mod def_path_hash_map;
pub mod definitions;
pub use rustc_span::def_id;
mod hir;
[dependencies]
libc = "0.2"
+odht = { version = "0.2.1", features = ["nightly"] }
snap = "1"
tracing = "0.1"
smallvec = { version = "1.6.1", features = ["union", "may_dangle"] }
/// This map is used to verify we get no hash conflicts between
/// `StableCrateId` values.
- stable_crate_ids: FxHashMap<StableCrateId, CrateNum>,
+ pub(crate) stable_crate_ids: FxHashMap<StableCrateId, CrateNum>,
/// Unused externs of the crate
unused_externs: Vec<Symbol>,
mod cstore_impl;
-crate struct MetadataBlob(MetadataRef);
+/// 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
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`. See `raw_def_id_to_def_id` for more details about how
- /// this is used.
- def_path_hash_map: OnceCell<UnhashMap<DefPathHash, DefIndex>>,
+ /// 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.
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>>,
/// Abstract over the various ways one can create metadata decoders.
pub(super) trait Metadata<'a, 'tcx>: Copy {
- fn raw_bytes(self) -> &'a [u8];
+ fn blob(self) -> &'a MetadataBlob;
+
fn cdata(self) -> Option<CrateMetadataRef<'a>> {
None
}
fn decoder(self, pos: usize) -> DecodeContext<'a, 'tcx> {
let tcx = self.tcx();
DecodeContext {
- opaque: opaque::Decoder::new(self.raw_bytes(), pos),
+ 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,
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for &'a MetadataBlob {
- fn raw_bytes(self) -> &'a [u8] {
- &self.0
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ self
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a MetadataBlob, &'tcx Session) {
- fn raw_bytes(self) -> &'a [u8] {
- let (blob, _) = self;
- &blob.0
+ #[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 &'a CrateMetadataRef<'a> {
- fn raw_bytes(self) -> &'a [u8] {
- self.blob.raw_bytes()
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ &self.blob
}
+ #[inline]
fn cdata(self) -> Option<CrateMetadataRef<'a>> {
Some(*self)
}
}
impl<'a, 'tcx> Metadata<'a, 'tcx> for (&'a CrateMetadataRef<'a>, &'tcx Session) {
- fn raw_bytes(self) -> &'a [u8] {
- self.0.raw_bytes()
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ &self.0.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 (&'a CrateMetadataRef<'a>, TyCtxt<'tcx>) {
- fn raw_bytes(self) -> &'a [u8] {
- self.0.raw_bytes()
+ #[inline]
+ fn blob(self) -> &'a MetadataBlob {
+ &self.0.blob
}
+ #[inline]
fn cdata(self) -> Option<CrateMetadataRef<'a>> {
Some(*self.0)
}
+ #[inline]
fn tcx(self) -> Option<TyCtxt<'tcx>> {
Some(self.1)
}
}
impl<'a, 'tcx> DecodeContext<'a, 'tcx> {
+ #[inline]
fn tcx(&self) -> TyCtxt<'tcx> {
- self.tcx.expect("missing TyCtxt in DecodeContext")
+ debug_assert!(self.tcx.is_some(), "missing TyCtxt in DecodeContext");
+ self.tcx.unwrap()
+ }
+
+ #[inline]
+ pub fn blob(&self) -> &'a MetadataBlob {
+ self.blob
}
- fn cdata(&self) -> CrateMetadataRef<'a> {
- self.cdata.expect("missing CrateMetadata in DecodeContext")
+ #[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 {
self.lazy_state = LazyState::Previous(NonZeroUsize::new(position + min_size).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> {
impl MetadataBlob {
crate fn new(metadata_ref: MetadataRef) -> MetadataBlob {
- MetadataBlob(metadata_ref)
+ MetadataBlob(Lrc::new(metadata_ref))
}
crate fn is_compatible(&self) -> bool {
- self.raw_bytes().starts_with(METADATA_HEADER)
+ self.blob().starts_with(METADATA_HEADER)
}
crate fn get_rustc_version(&self) -> String {
}
crate fn get_root(&self) -> CrateRoot<'tcx> {
- let slice = self.raw_bytes();
+ let slice = &self.blob()[..];
let offset = METADATA_HEADER.len();
let pos = (((slice[offset + 0] as u32) << 24)
| ((slice[offset + 1] as u32) << 16)
.or_insert_with(|| self.root.tables.def_keys.get(self, index).unwrap().decode(self))
}
- /// Finds the corresponding `DefId` for the provided `DefPathHash`, if it exists.
- /// This is used by incremental compilation to map a serialized `DefPathHash` to
- /// its `DefId` in the current session.
- /// Normally, only one 'main' crate will change between incremental compilation sessions:
- /// all dependencies will be completely unchanged. In this case, we can avoid
- /// decoding every `DefPathHash` in the crate, since the `DefIndex` from the previous
- /// session will still be valid. If our 'guess' is wrong (the `DefIndex` no longer exists,
- /// or has a different `DefPathHash`, then we need to decode all `DefPathHashes` to determine
- /// the correct mapping).
- fn def_path_hash_to_def_id(
- &self,
- krate: CrateNum,
- index_guess: u32,
- hash: DefPathHash,
- ) -> Option<DefId> {
- let def_index_guess = DefIndex::from_u32(index_guess);
- let old_hash = self
- .root
- .tables
- .def_path_hashes
- .get(self, def_index_guess)
- .map(|lazy| lazy.decode(self));
-
- // Fast path: the definition and its index is unchanged from the
- // previous compilation session. There is no need to decode anything
- // else
- if old_hash == Some(hash) {
- return Some(DefId { krate, index: def_index_guess });
- }
-
- let is_proc_macro = self.is_proc_macro_crate();
-
- // 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.def_path_hash_map.get_or_init(|| {
- let end_id = self.root.tables.def_path_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 def_index = DefIndex::from_u32(i);
- // There may be gaps in the encoded table if we're decoding a proc-macro crate
- if let Some(hash) = self.root.tables.def_path_hashes.get(self, def_index) {
- map.insert(hash.decode(self), def_index);
- } else if !is_proc_macro {
- panic!("Missing def_path_hashes entry for {:?}", def_index);
- }
- }
- map
- });
- map.get(&hash).map(|index| DefId { krate, index: *index })
- }
-
// 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);
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, index_guess: u32, hash: ExpnHash) -> ExpnId {
debug_assert_eq!(ExpnId::from_hash(hash), None);
let index_guess = ExpnIndex::from_u32(index_guess);
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: Default::default(),
+ def_path_hash_map,
expn_hash_map: Default::default(),
alloc_decoding_state,
cnum,
self.get_crate_data(cnum).root.stable_crate_id
}
+ fn stable_crate_id_to_crate_num(&self, stable_crate_id: StableCrateId) -> CrateNum {
+ self.stable_crate_ids[&stable_crate_id]
+ }
+
/// Returns the `DefKey` for a given `DefId`. This indicates the
/// parent `DefId` as well as some idea of what kind of data the
/// `DefId` refers to.
self.get_crate_data(def.krate).def_path_hash(def.index)
}
- // See `CrateMetadataRef::def_path_hash_to_def_id` for more details
- fn def_path_hash_to_def_id(
- &self,
- cnum: CrateNum,
- index_guess: u32,
- hash: DefPathHash,
- ) -> Option<DefId> {
- self.get_crate_data(cnum).def_path_hash_to_def_id(cnum, index_guess, hash)
+ fn def_path_hash_to_def_id(&self, cnum: CrateNum, hash: DefPathHash) -> DefId {
+ let def_index = self.get_crate_data(cnum).def_path_hash_to_def_index(hash);
+ DefId { krate: cnum, index: def_index }
}
fn expn_hash_to_expn_id(&self, cnum: CrateNum, index_guess: u32, hash: ExpnHash) -> ExpnId {
--- /dev/null
+use crate::rmeta::DecodeContext;
+use crate::rmeta::EncodeContext;
+use crate::rmeta::MetadataBlob;
+use rustc_data_structures::owning_ref::OwningRef;
+use rustc_hir::def_path_hash_map::{Config as HashMapConfig, DefPathHashMap};
+use rustc_serialize::{opaque, Decodable, Decoder, Encodable, Encoder};
+use rustc_span::def_id::{DefIndex, DefPathHash};
+
+crate enum DefPathHashMapRef<'tcx> {
+ OwnedFromMetadata(odht::HashTable<HashMapConfig, OwningRef<MetadataBlob, [u8]>>),
+ BorrowedFromTcx(&'tcx DefPathHashMap),
+}
+
+impl DefPathHashMapRef<'tcx> {
+ #[inline]
+ pub fn def_path_hash_to_def_index(&self, def_path_hash: &DefPathHash) -> DefIndex {
+ match *self {
+ DefPathHashMapRef::OwnedFromMetadata(ref map) => map.get(def_path_hash).unwrap(),
+ DefPathHashMapRef::BorrowedFromTcx(_) => {
+ panic!("DefPathHashMap::BorrowedFromTcx variant only exists for serialization")
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for DefPathHashMapRef<'tcx> {
+ fn encode(&self, e: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
+ match *self {
+ DefPathHashMapRef::BorrowedFromTcx(def_path_hash_map) => {
+ let bytes = def_path_hash_map.raw_bytes();
+ e.emit_usize(bytes.len())?;
+ e.emit_raw_bytes(bytes)
+ }
+ DefPathHashMapRef::OwnedFromMetadata(_) => {
+ panic!("DefPathHashMap::OwnedFromMetadata variant only exists for deserialization")
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for DefPathHashMapRef<'static> {
+ fn decode(d: &mut DecodeContext<'a, 'tcx>) -> Result<DefPathHashMapRef<'static>, String> {
+ // Import TyDecoder so we can access the DecodeContext::position() method
+ use crate::rustc_middle::ty::codec::TyDecoder;
+
+ let len = d.read_usize()?;
+ let pos = d.position();
+ let o = OwningRef::new(d.blob().clone()).map(|x| &x[pos..pos + len]);
+
+ // Although we already have the data we need via the OwningRef, we still need
+ // to advance the DecodeContext's position so it's in a valid state after
+ // the method. We use read_raw_bytes() for that.
+ let _ = d.read_raw_bytes(len);
+
+ let inner = odht::HashTable::from_raw_bytes(o).map_err(|e| format!("{}", e))?;
+ Ok(DefPathHashMapRef::OwnedFromMetadata(inner))
+ }
+}
+use crate::rmeta::def_path_hash_map::DefPathHashMapRef;
use crate::rmeta::table::{FixedSizeEncoding, TableBuilder};
use crate::rmeta::*;
}
}
+ fn encode_def_path_hash_map(&mut self) -> Lazy<DefPathHashMapRef<'tcx>> {
+ self.lazy(DefPathHashMapRef::BorrowedFromTcx(
+ self.tcx.resolutions(()).definitions.def_path_hash_to_def_index_map(),
+ ))
+ }
+
fn encode_source_map(&mut self) -> Lazy<[rustc_span::SourceFile]> {
let source_map = self.tcx.sess.source_map();
let all_source_files = source_map.files();
let (syntax_contexts, expn_data, expn_hashes) = self.encode_hygiene();
let hygiene_bytes = self.position() - i;
+ i = self.position();
+ let def_path_hash_map = self.encode_def_path_hash_map();
+ let def_path_hash_map_bytes = self.position() - i;
+
// Encode source_map. This needs to be done last,
// since encoding `Span`s tells us which `SourceFiles` we actually
// need to encode.
syntax_contexts,
expn_data,
expn_hashes,
+ def_path_hash_map,
});
let total_bytes = self.position();
eprintln!(" impl bytes: {}", impl_bytes);
eprintln!(" exp. symbols bytes: {}", exported_symbols_bytes);
eprintln!(" def-path table bytes: {}", def_path_table_bytes);
+ eprintln!(" def-path hashes bytes: {}", def_path_hash_map_bytes);
eprintln!(" proc-macro-data-bytes: {}", proc_macro_data_bytes);
eprintln!(" mir bytes: {}", mir_bytes);
eprintln!(" item bytes: {}", item_bytes);
use decoder::Metadata;
+use def_path_hash_map::DefPathHashMapRef;
use table::{Table, TableBuilder};
use rustc_ast::{self as ast, MacroDef};
use rustc_span::hygiene::SyntaxContextData;
mod decoder;
+mod def_path_hash_map;
mod encoder;
mod table;
expn_data: ExpnDataTable,
expn_hashes: ExpnHashTable,
+ def_path_hash_map: Lazy<DefPathHashMapRef<'tcx>>,
+
source_map: Lazy<[rustc_span::SourceFile]>,
compiler_builtins: bool,
debug!("Table::lookup: index={:?} len={:?}", i, self.meta);
let start = self.position.get();
- let bytes = &metadata.raw_bytes()[start..start + self.meta];
+ let bytes = &metadata.blob()[start..start + self.meta];
<Option<T>>::maybe_read_from_bytes_at(bytes, i.index())?
}
/// has been removed.
fn extract_def_id(&self, tcx: TyCtxt<'tcx>) -> Option<DefId> {
if self.kind.can_reconstruct_query_key() {
- tcx.on_disk_cache.as_ref()?.def_path_hash_to_def_id(tcx, DefPathHash(self.hash.into()))
+ Some(
+ tcx.on_disk_cache
+ .as_ref()?
+ .def_path_hash_to_def_id(tcx, DefPathHash(self.hash.into())),
+ )
} else {
None
}
}
fn to_fingerprint(&self, tcx: TyCtxt<'tcx>) -> Fingerprint {
- let hash = tcx.def_path_hash(*self);
- // If this is a foreign `DefId`, store its current value
- // in the incremental cache. When we decode the cache,
- // we will use the old DefIndex as an initial guess for
- // a lookup into the crate metadata.
- if !self.is_local() {
- if let Some(cache) = &tcx.on_disk_cache {
- cache.store_foreign_def_id_hash(*self, hash);
- }
- }
- hash.0
+ tcx.def_path_hash(*self).0
}
fn to_debug_str(&self, tcx: TyCtxt<'tcx>) -> String {
type DepKind = DepKind;
type StableHashingContext = StableHashingContext<'tcx>;
- fn register_reused_dep_node(&self, dep_node: &DepNode) {
- if let Some(cache) = self.on_disk_cache.as_ref() {
- cache.register_reused_dep_node(*self, dep_node)
- }
- }
-
+ #[inline]
fn create_stable_hashing_context(&self) -> Self::StableHashingContext {
TyCtxt::create_stable_hashing_context(*self)
}
// incr. comp. uses to identify a CrateNum.
fn crate_name(&self, cnum: CrateNum) -> Symbol;
fn stable_crate_id(&self, cnum: CrateNum) -> StableCrateId;
+ fn stable_crate_id_to_crate_num(&self, stable_crate_id: StableCrateId) -> CrateNum;
/// Fetch a DefId from a DefPathHash for a foreign crate.
- fn def_path_hash_to_def_id(
- &self,
- cnum: CrateNum,
- index_guess: u32,
- hash: DefPathHash,
- ) -> Option<DefId>;
+ fn def_path_hash_to_def_id(&self, cnum: CrateNum, hash: DefPathHash) -> DefId;
fn expn_hash_to_expn_id(&self, cnum: CrateNum, index_guess: u32, hash: ExpnHash) -> ExpnId;
// utility functions
//! Type context book-keeping.
use crate::arena::Arena;
-use crate::dep_graph::{DepGraph, DepNode};
+use crate::dep_graph::DepGraph;
use crate::hir::place::Place as HirPlace;
use crate::ich::{NodeIdHashingMode, StableHashingContext};
use crate::infer::canonical::{Canonical, CanonicalVarInfo, CanonicalVarInfos};
/// Converts a `DefPathHash` to its corresponding `DefId` in the current compilation
/// session, if it still exists. This is used during incremental compilation to
/// turn a deserialized `DefPathHash` into its current `DefId`.
- fn def_path_hash_to_def_id(
- &self,
- tcx: TyCtxt<'tcx>,
- def_path_hash: DefPathHash,
- ) -> Option<DefId>;
-
- /// If the given `dep_node`'s hash still exists in the current compilation,
- /// and its current `DefId` is foreign, calls `store_foreign_def_id` with it.
- ///
- /// Normally, `store_foreign_def_id_hash` can be called directly by
- /// the dependency graph when we construct a `DepNode`. However,
- /// when we re-use a deserialized `DepNode` from the previous compilation
- /// session, we only have the `DefPathHash` available. This method is used
- /// to that any `DepNode` that we re-use has a `DefPathHash` -> `RawId` written
- /// out for usage in the next compilation session.
- fn register_reused_dep_node(&self, tcx: TyCtxt<'tcx>, dep_node: &DepNode);
- fn store_foreign_def_id_hash(&self, def_id: DefId, hash: DefPathHash);
+ fn def_path_hash_to_def_id(&self, tcx: TyCtxt<'tcx>, def_path_hash: DefPathHash) -> DefId;
fn drop_serialized_data(&self, tcx: TyCtxt<'tcx>);
}
}
+ /// Maps a StableCrateId to the corresponding CrateNum. This method assumes
+ /// that the crate in question has already been loaded by the CrateStore.
+ #[inline]
+ pub fn stable_crate_id_to_crate_num(self, stable_crate_id: StableCrateId) -> CrateNum {
+ if stable_crate_id == self.sess.local_stable_crate_id() {
+ LOCAL_CRATE
+ } else {
+ self.untracked_resolutions.cstore.stable_crate_id_to_crate_num(stable_crate_id)
+ }
+ }
+
pub fn def_path_debug_str(self, def_id: DefId) -> String {
// We are explicitly not going through queries here in order to get
// crate name and stable crate id since this code is called from debug!()
use crate::QueryCtxt;
use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
use rustc_data_structures::memmap::Mmap;
-use rustc_data_structures::sync::{HashMapExt, Lock, Lrc, OnceCell, RwLock};
+use rustc_data_structures::sync::{HashMapExt, Lock, Lrc, RwLock};
use rustc_data_structures::unhash::UnhashMap;
use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, StableCrateId, LOCAL_CRATE};
use rustc_hir::definitions::DefPathHash;
use rustc_index::vec::{Idx, IndexVec};
-use rustc_middle::dep_graph::{DepNode, DepNodeIndex, SerializedDepNodeIndex};
+use rustc_middle::dep_graph::{DepNodeIndex, SerializedDepNodeIndex};
use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
use rustc_middle::mir::{self, interpret};
use rustc_middle::thir;
use rustc_span::source_map::{SourceMap, StableSourceFileId};
use rustc_span::CachingSourceMapView;
use rustc_span::{BytePos, ExpnData, ExpnHash, Pos, SourceFile, Span};
-use std::collections::hash_map::Entry;
use std::mem;
const TAG_FILE_FOOTER: u128 = 0xC0FFEE_C0FFEE_C0FFEE_C0FFEE_C0FFEE;
// session.
current_side_effects: Lock<FxHashMap<DepNodeIndex, QuerySideEffects>>,
- cnum_map: OnceCell<UnhashMap<StableCrateId, CrateNum>>,
-
source_map: &'sess SourceMap,
file_index_to_stable_id: FxHashMap<SourceFileIndex, EncodedSourceFileId>,
expn_data: UnhashMap<ExpnHash, AbsoluteBytePos>,
// Additional information used when decoding hygiene data.
hygiene_context: HygieneDecodeContext,
- // Maps `DefPathHash`es to their `RawDefId`s from the *previous*
+ // Maps `ExpnHash`es to their raw value from the *previous*
// compilation session. This is used as an initial 'guess' when
- // we try to map a `DefPathHash` to its `DefId` in the current compilation
- // session.
- foreign_def_path_hashes: UnhashMap<DefPathHash, RawDefId>,
- // Likewise for ExpnId.
+ // we try to map an `ExpnHash` to its value in the current
+ // compilation session.
foreign_expn_data: UnhashMap<ExpnHash, u32>,
-
- // The *next* compilation sessison's `foreign_def_path_hashes` - at
- // the end of our current compilation session, this will get written
- // out to the `foreign_def_path_hashes` field of the `Footer`, which
- // will become `foreign_def_path_hashes` of the next compilation session.
- // This stores any `DefPathHash` that we may need to map to a `DefId`
- // during the next compilation session.
- latest_foreign_def_path_hashes: Lock<UnhashMap<DefPathHash, RawDefId>>,
-
- // Caches all lookups of `DefPathHashes`, both for local and foreign
- // definitions. A definition from the previous compilation session
- // may no longer exist in the current compilation session, so
- // we use `Option<DefId>` so that we can cache a lookup failure.
- def_path_hash_to_def_id_cache: Lock<UnhashMap<DefPathHash, Option<DefId>>>,
}
// This type is used only for serialization and deserialization.
syntax_contexts: FxHashMap<u32, AbsoluteBytePos>,
// See `OnDiskCache.expn_data`
expn_data: UnhashMap<ExpnHash, AbsoluteBytePos>,
- foreign_def_path_hashes: UnhashMap<DefPathHash, RawDefId>,
foreign_expn_data: UnhashMap<ExpnHash, u32>,
}
}
}
-/// Represents a potentially invalid `DefId`. This is used during incremental
-/// compilation to represent a `DefId` from the *previous* compilation session,
-/// which may no longer be valid. This is used to help map a `DefPathHash`
-/// to a `DefId` in the current compilation session.
-#[derive(Encodable, Decodable, Copy, Clone, Debug)]
-crate struct RawDefId {
- // We deliberately do not use `CrateNum` and `DefIndex`
- // here, since a crate/index from the previous compilation
- // session may no longer exist.
- pub krate: u32,
- pub index: u32,
-}
-
/// An `EncodedSourceFileId` is the same as a `StableSourceFileId` except that
/// the source crate is represented as a [StableCrateId] instead of as a
/// `CrateNum`. This way `EncodedSourceFileId` can be encoded and decoded
}
impl EncodedSourceFileId {
- fn translate(&self, cnum_map: &UnhashMap<StableCrateId, CrateNum>) -> StableSourceFileId {
- let cnum = cnum_map[&self.stable_crate_id];
+ fn translate(&self, tcx: TyCtxt<'_>) -> StableSourceFileId {
+ let cnum = tcx.stable_crate_id_to_crate_num(self.stable_crate_id);
StableSourceFileId { file_name_hash: self.file_name_hash, cnum }
}
serialized_data: RwLock::new(Some(data)),
file_index_to_stable_id: footer.file_index_to_stable_id,
file_index_to_file: Default::default(),
- cnum_map: OnceCell::new(),
source_map: sess.source_map(),
current_side_effects: Default::default(),
query_result_index: footer.query_result_index.into_iter().collect(),
expn_data: footer.expn_data,
foreign_expn_data: footer.foreign_expn_data,
hygiene_context: Default::default(),
- foreign_def_path_hashes: footer.foreign_def_path_hashes,
- latest_foreign_def_path_hashes: Default::default(),
- def_path_hash_to_def_id_cache: Default::default(),
}
}
serialized_data: RwLock::new(None),
file_index_to_stable_id: Default::default(),
file_index_to_file: Default::default(),
- cnum_map: OnceCell::new(),
source_map,
current_side_effects: Default::default(),
query_result_index: Default::default(),
expn_data: UnhashMap::default(),
foreign_expn_data: UnhashMap::default(),
hygiene_context: Default::default(),
- foreign_def_path_hashes: Default::default(),
- latest_foreign_def_path_hashes: Default::default(),
- def_path_hash_to_def_id_cache: Default::default(),
}
}
/// In order to serialize the new on-disk cache, the former on-disk cache file needs to be
/// deleted, hence we won't be able to refer to its memmapped data.
fn drop_serialized_data(&self, tcx: TyCtxt<'tcx>) {
- // Register any dep nodes that we reused from the previous session,
- // but didn't `DepNode::construct` in this session. This ensures
- // that their `DefPathHash` to `RawDefId` mappings are registered
- // in 'latest_foreign_def_path_hashes' if necessary, since that
- // normally happens in `DepNode::construct`.
- tcx.dep_graph.register_reused_dep_nodes(tcx);
-
// Load everything into memory so we can write it out to the on-disk
// cache. The vast majority of cacheable query results should already
// be in memory, so this should be a cheap operation.
(file_to_file_index, file_index_to_stable_id)
};
- let latest_foreign_def_path_hashes = self.latest_foreign_def_path_hashes.lock().clone();
let hygiene_encode_context = HygieneEncodeContext::default();
let mut encoder = CacheEncoder {
source_map: CachingSourceMapView::new(tcx.sess.source_map()),
file_to_file_index,
hygiene_context: &hygiene_encode_context,
- latest_foreign_def_path_hashes,
};
// Encode query results.
},
)?;
- let foreign_def_path_hashes =
- std::mem::take(&mut encoder.latest_foreign_def_path_hashes);
-
// `Encode the file footer.
let footer_pos = encoder.position() as u64;
encoder.encode_tagged(
syntax_contexts,
expn_data,
foreign_expn_data,
- foreign_def_path_hashes,
},
)?;
})
}
- fn def_path_hash_to_def_id(&self, tcx: TyCtxt<'tcx>, hash: DefPathHash) -> Option<DefId> {
- let mut cache = self.def_path_hash_to_def_id_cache.lock();
- match cache.entry(hash) {
- Entry::Occupied(e) => *e.get(),
- Entry::Vacant(e) => {
- debug!("def_path_hash_to_def_id({:?})", hash);
- // Check if the `DefPathHash` corresponds to a definition in the current
- // crate
- if let Some(def_id) =
- tcx.definitions_untracked().local_def_path_hash_to_def_id(hash)
- {
- let def_id = def_id.to_def_id();
- e.insert(Some(def_id));
- return Some(def_id);
- }
- // This `raw_def_id` represents the `DefId` of this `DefPathHash` in
- // the *previous* compliation session. The `DefPathHash` includes the
- // owning crate, so if the corresponding definition still exists in the
- // current compilation session, the crate is guaranteed to be the same
- // (otherwise, we would compute a different `DefPathHash`).
- let raw_def_id = self.get_raw_def_id(&hash)?;
- debug!("def_path_hash_to_def_id({:?}): raw_def_id = {:?}", hash, raw_def_id);
- // If the owning crate no longer exists, the corresponding definition definitely
- // no longer exists.
- let krate = self.try_remap_cnum(tcx, hash.stable_crate_id())?;
- debug!("def_path_hash_to_def_id({:?}): krate = {:?}", hash, krate);
- // If our `DefPathHash` corresponded to a definition in the local crate,
- // we should have either found it in `local_def_path_hash_to_def_id`, or
- // never attempted to load it in the first place. Any query result or `DepNode`
- // that references a local `DefId` should depend on some HIR-related `DepNode`.
- // If a local definition is removed/modified such that its old `DefPathHash`
- // no longer has a corresponding definition, that HIR-related `DepNode` should
- // end up red. This should prevent us from ever calling
- // `tcx.def_path_hash_to_def_id`, since we'll end up recomputing any
- // queries involved.
- debug_assert_ne!(krate, LOCAL_CRATE);
- // Try to find a definition in the current session, using the previous `DefIndex`
- // as an initial guess.
- let opt_def_id =
- tcx.cstore_untracked().def_path_hash_to_def_id(krate, raw_def_id.index, hash);
- debug!("def_path_to_def_id({:?}): opt_def_id = {:?}", hash, opt_def_id);
- e.insert(opt_def_id);
- opt_def_id
- }
- }
- }
+ fn def_path_hash_to_def_id(&self, tcx: TyCtxt<'tcx>, hash: DefPathHash) -> DefId {
+ debug!("def_path_hash_to_def_id({:?})", hash);
- fn register_reused_dep_node(&self, tcx: TyCtxt<'sess>, dep_node: &DepNode) {
- // For reused dep nodes, we only need to store the mapping if the node
- // is one whose query key we can reconstruct from the hash. We use the
- // mapping to aid that reconstruction in the next session. While we also
- // use it to decode `DefId`s we encoded in the cache as `DefPathHashes`,
- // they're already registered during `DefId` encoding.
- if dep_node.kind.can_reconstruct_query_key() {
- let hash = DefPathHash(dep_node.hash.into());
-
- // We can't simply copy the `RawDefId` from `foreign_def_path_hashes` to
- // `latest_foreign_def_path_hashes`, since the `RawDefId` might have
- // changed in the current compilation session (e.g. we've added/removed crates,
- // or added/removed definitions before/after the target definition).
- if let Some(def_id) = self.def_path_hash_to_def_id(tcx, hash) {
- if !def_id.is_local() {
- self.store_foreign_def_id_hash(def_id, hash);
- }
- }
- }
- }
+ let stable_crate_id = hash.stable_crate_id();
- fn store_foreign_def_id_hash(&self, def_id: DefId, hash: DefPathHash) {
- // We may overwrite an existing entry, but it will have the same value,
- // so it's fine
- self.latest_foreign_def_path_hashes
- .lock()
- .insert(hash, RawDefId { krate: def_id.krate.as_u32(), index: def_id.index.as_u32() });
+ // If this is a DefPathHash from the local crate, we can look up the
+ // DefId in the tcx's `Definitions`.
+ if stable_crate_id == tcx.sess.local_stable_crate_id() {
+ tcx.definitions_untracked().local_def_path_hash_to_def_id(hash).to_def_id()
+ } else {
+ // If this is a DefPathHash from an upstream crate, let the CrateStore map
+ // it to a DefId.
+ let cnum = tcx.cstore_untracked().stable_crate_id_to_crate_num(stable_crate_id);
+ tcx.cstore_untracked().def_path_hash_to_def_id(cnum, hash)
+ }
}
}
debug_assert!(prev.is_none());
}
- fn get_raw_def_id(&self, hash: &DefPathHash) -> Option<RawDefId> {
- self.foreign_def_path_hashes.get(hash).copied()
- }
-
- fn try_remap_cnum(&self, tcx: TyCtxt<'_>, stable_crate_id: StableCrateId) -> Option<CrateNum> {
- let cnum_map = self.cnum_map.get_or_init(|| Self::compute_cnum_map(tcx));
- debug!("try_remap_cnum({:?}): cnum_map={:?}", stable_crate_id, cnum_map);
-
- cnum_map.get(&stable_crate_id).copied()
- }
-
/// Returns the cached query result if there is something in the cache for
/// the given `SerializedDepNodeIndex`; otherwise returns `None`.
pub fn try_load_query_result<'tcx, T>(
where
T: Decodable<CacheDecoder<'a, 'tcx>>,
{
- let cnum_map = self.cnum_map.get_or_init(|| Self::compute_cnum_map(tcx));
-
let serialized_data = self.serialized_data.read();
let mut decoder = CacheDecoder {
tcx,
opaque: opaque::Decoder::new(serialized_data.as_deref().unwrap_or(&[]), pos.to_usize()),
source_map: self.source_map,
- cnum_map,
file_index_to_file: &self.file_index_to_file,
file_index_to_stable_id: &self.file_index_to_stable_id,
alloc_decoding_session: self.alloc_decoding_state.new_decoding_session(),
};
f(&mut decoder)
}
-
- // This function builds mapping from previous-session-`CrateNum` to
- // current-session-`CrateNum`. There might be `CrateNum`s from the previous
- // `Session` that don't occur in the current one. For these, the mapping
- // maps to None.
- fn compute_cnum_map(tcx: TyCtxt<'_>) -> UnhashMap<StableCrateId, CrateNum> {
- tcx.dep_graph.with_ignore(|| {
- tcx.crates(())
- .iter()
- .chain(std::iter::once(&LOCAL_CRATE))
- .map(|&cnum| {
- let hash = tcx.def_path_hash(cnum.as_def_id()).stable_crate_id();
- (hash, cnum)
- })
- .collect()
- })
- }
}
//- DECODING -------------------------------------------------------------------
tcx: TyCtxt<'tcx>,
opaque: opaque::Decoder<'a>,
source_map: &'a SourceMap,
- cnum_map: &'a UnhashMap<StableCrateId, CrateNum>,
file_index_to_file: &'a Lock<FxHashMap<SourceFileIndex, Lrc<SourceFile>>>,
file_index_to_stable_id: &'a FxHashMap<SourceFileIndex, EncodedSourceFileId>,
alloc_decoding_session: AllocDecodingSession<'a>,
impl<'a, 'tcx> CacheDecoder<'a, 'tcx> {
fn file_index_to_file(&self, index: SourceFileIndex) -> Lrc<SourceFile> {
let CacheDecoder {
+ tcx,
ref file_index_to_file,
ref file_index_to_stable_id,
ref source_map,
- ref cnum_map,
..
} = *self;
.borrow_mut()
.entry(index)
.or_insert_with(|| {
- let stable_id = file_index_to_stable_id[&index].translate(cnum_map);
+ let stable_id = file_index_to_stable_id[&index].translate(tcx);
source_map
.source_file_by_stable_id(stable_id)
.expect("failed to lookup `SourceFile` in new context")
return Ok(expn_id);
}
- let krate = decoder.cnum_map[&hash.stable_crate_id()];
+ let krate = decoder.tcx.stable_crate_id_to_crate_num(hash.stable_crate_id());
let expn_id = if krate == LOCAL_CRATE {
// We look up the position of the associated `ExpnData` and decode it.
impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for CrateNum {
fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> Result<Self, String> {
let stable_id = StableCrateId::decode(d)?;
- let cnum = d.cnum_map[&stable_id];
+ let cnum = d.tcx.stable_crate_id_to_crate_num(stable_id);
Ok(cnum)
}
}
// If we get to this point, then all of the query inputs were green,
// which means that the definition with this hash is guaranteed to
// still exist in the current compilation session.
- Ok(d.tcx()
- .on_disk_cache
- .as_ref()
- .unwrap()
- .def_path_hash_to_def_id(d.tcx(), def_path_hash)
- .unwrap())
+ Ok(d.tcx().on_disk_cache.as_ref().unwrap().def_path_hash_to_def_id(d.tcx(), def_path_hash))
}
}
source_map: CachingSourceMapView<'tcx>,
file_to_file_index: FxHashMap<*const SourceFile, SourceFileIndex>,
hygiene_context: &'a HygieneEncodeContext,
- latest_foreign_def_path_hashes: UnhashMap<DefPathHash, RawDefId>,
}
impl<'a, 'tcx, E> CacheEncoder<'a, 'tcx, E>
E: 'a + OpaqueEncoder,
{
fn encode(&self, s: &mut CacheEncoder<'a, 'tcx, E>) -> Result<(), E::Error> {
- let def_path_hash = s.tcx.def_path_hash(*self);
- // Store additional information when we encode a foreign `DefId`,
- // so that we can map its `DefPathHash` back to a `DefId` in the next
- // compilation session.
- if !self.is_local() {
- s.latest_foreign_def_path_hashes.insert(
- def_path_hash,
- RawDefId { krate: self.krate.as_u32(), index: self.index.as_u32() },
- );
- }
- def_path_hash.encode(s)
+ s.tcx.def_path_hash(*self).encode(s)
}
}
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]
pub struct DepNode<K> {
pub kind: K,
- // Important - whenever a `DepNode` is constructed, we need to make
- // sure to register a `DefPathHash -> DefId` mapping if needed.
- // This is currently done in two places:
- //
- // * When a `DepNode::construct` is called, `arg.to_fingerprint()`
- // is responsible for calling `OnDiskCache::store_foreign_def_id_hash`
- // if needed
- // * When we serialize the on-disk cache, `OnDiskCache::serialize` is
- // responsible for calling `DepGraph::register_reused_dep_nodes`.
- //
- // FIXME: Enforce this by preventing manual construction of `DefNode`
- // (e.g. add a `_priv: ()` field)
pub hash: PackedFingerprint,
}
}
}
- // Register reused dep nodes (i.e. nodes we've marked red or green) with the context.
- pub fn register_reused_dep_nodes<Ctxt: DepContext<DepKind = K>>(&self, tcx: Ctxt) {
- let data = self.data.as_ref().unwrap();
- for prev_index in data.colors.values.indices() {
- match data.colors.get(prev_index) {
- Some(DepNodeColor::Red) | Some(DepNodeColor::Green(_)) => {
- let dep_node = data.previous.index_to_node(prev_index);
- tcx.register_reused_dep_node(&dep_node);
- }
- None => {}
- }
- }
- }
-
pub fn print_incremental_info(&self) {
if let Some(data) = &self.data {
data.current.encoder.borrow().print_incremental_info(
/// Access the DepGraph.
fn dep_graph(&self) -> &DepGraph<Self::DepKind>;
- fn register_reused_dep_node(&self, dep_node: &DepNode<Self::DepKind>);
-
/// Access the profiler.
fn profiler(&self) -> &SelfProfilerRef;
"num-integer",
"num-traits",
"object",
+ "odht",
"once_cell",
"opaque-debug",
"parking_lot",
projects / rust.git / commitdiff