Remove RawDefId tracking infrastructure from incr. comp. framework.

This infrastructure is obsolete now with the new encoding scheme for
the DefPathHash->DefIndex maps in crate metadata.
This commit is contained in:
Michael Woerister 2021-07-20 14:03:20 +02:00
parent 960893c50a
commit 5445715c20
7 changed files with 6 additions and 134 deletions

View file

@ -6,7 +6,7 @@ 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;
@ -86,27 +86,9 @@ pub struct OnDiskCache<'sess> {
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*
// 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>,
// FIXME(mw): Update this comment:
// Likewise for ExpnId.
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.
@ -121,7 +103,6 @@ struct Footer {
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>,
}
@ -144,19 +125,6 @@ impl AbsoluteBytePos {
}
}
/// 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
@ -220,9 +188,6 @@ impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
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(),
}
}
@ -241,9 +206,6 @@ impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
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(),
}
}
@ -253,13 +215,6 @@ impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
/// 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.
@ -293,7 +248,6 @@ impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
(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 {
@ -305,7 +259,6 @@ impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
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.
@ -382,9 +335,6 @@ impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
},
)?;
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(
@ -397,7 +347,6 @@ impl<'sess> rustc_middle::ty::OnDiskCache<'sess> for OnDiskCache<'sess> {
syntax_contexts,
expn_data,
foreign_expn_data,
foreign_def_path_hashes,
},
)?;
@ -460,17 +409,6 @@ impl<'sess> OnDiskCache<'sess> {
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>(
@ -911,7 +849,6 @@ pub struct CacheEncoder<'a, 'tcx, E: OpaqueEncoder> {
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>
@ -1044,17 +981,7 @@ where
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)
}
}