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Auto merge of #119192 - michaelwoerister:mcp533-push, r=cjgillot

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Replace a number of FxHashMaps/Sets with stable-iteration-order alternatives

This PR replaces almost all of the remaining `FxHashMap`s in query results with either `FxIndexMap` or `UnordMap`. The only case that is missing is the `EffectiveVisibilities` struct which turned out to not be straightforward to transform. Once that is done too, we can remove the `HashStable` implementation from `HashMap`.

The first commit adds the `StableCompare` trait which is a companion trait to `StableOrd`. Some types like `Symbol` can be compared in a cross-session stable way, but their `Ord` implementation is not stable. In such cases, a `StableCompare` implementation can be provided to offer a lightweight way for stable sorting. The more heavyweight option is to sort via `ToStableHashKey`, but then sorting needs to have access to a stable hashing context and `ToStableHashKey` can also be expensive as in the case of `Symbol` where it has to allocate a `String`.

The rest of the commits are rather mechanical and don't overlap, so they are best reviewed individually.

Part of [MCP 533](https://github.com/rust-lang/compiler-team/issues/533).
This commit is contained in:
bors
2024-01-05 19:38:27 +00:00
parent 11035f9f52 077540cedf
commit b8c207435c
30 changed files with 256 additions and 147 deletions
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17
compiler/rustc_metadata/src/rmeta/encoder.rs
View File

@@ -2,10 +2,8 @@ use crate::errors::{FailCreateFileEncoder, FailWriteFile};
use crate::rmeta::*;
use rustc_ast::Attribute;
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::fx::FxIndexSet;
use rustc_data_structures::memmap::{Mmap, MmapMut};
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_data_structures::sync::{join, par_for_each_in, Lrc};
use rustc_data_structures::temp_dir::MaybeTempDir;
use rustc_hir as hir;
@@ -1914,14 +1912,15 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
empty_proc_macro!(self);
let tcx = self.tcx;
let lib_features = tcx.lib_features(LOCAL_CRATE);
self.lazy_array(lib_features.to_vec())
self.lazy_array(lib_features.to_sorted_vec())
}
fn encode_stability_implications(&mut self) -> LazyArray<(Symbol, Symbol)> {
empty_proc_macro!(self);
let tcx = self.tcx;
let implications = tcx.stability_implications(LOCAL_CRATE);
self.lazy_array(implications.iter().map(|(k, v)| (*k, *v)))
let sorted = implications.to_sorted_stable_ord();
self.lazy_array(sorted.into_iter().map(|(k, v)| (*k, *v)))
}
fn encode_diagnostic_items(&mut self) -> LazyArray<(Symbol, DefIndex)> {
@@ -2033,14 +2032,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
fn encode_incoherent_impls(&mut self) -> LazyArray<IncoherentImpls> {
empty_proc_macro!(self);
let tcx = self.tcx;
let mut all_impls: Vec<_> = tcx.crate_inherent_impls(()).incoherent_impls.iter().collect();
tcx.with_stable_hashing_context(|mut ctx| {
all_impls.sort_by_cached_key(|&(&simp, _)| {
let mut hasher = StableHasher::new();
simp.hash_stable(&mut ctx, &mut hasher);
hasher.finish::<Fingerprint>()
})
let all_impls = tcx.with_stable_hashing_context(|hcx| {
tcx.crate_inherent_impls(()).incoherent_impls.to_sorted(&hcx, true)
});
let all_impls: Vec<_> = all_impls
.into_iter()
.map(|(&simp, impls)| {

4
compiler/rustc_metadata/src/rmeta/mod.rs
View File

@@ -12,7 +12,7 @@ use rustc_attr as attr;
use rustc_data_structures::svh::Svh;
use rustc_hir as hir;
use rustc_hir::def::{CtorKind, DefKind, DocLinkResMap};
use rustc_hir::def_id::{CrateNum, DefId, DefIndex, DefPathHash, StableCrateId};
use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIndex, DefPathHash, StableCrateId};
use rustc_hir::definitions::DefKey;
use rustc_hir::lang_items::LangItem;
use rustc_index::bit_set::BitSet;
@@ -459,7 +459,7 @@ define_tables! {
macro_definition: Table<DefIndex, LazyValue<ast::DelimArgs>>,
proc_macro: Table<DefIndex, MacroKind>,
deduced_param_attrs: Table<DefIndex, LazyArray<DeducedParamAttrs>>,
trait_impl_trait_tys: Table<DefIndex, LazyValue<FxHashMap<DefId, ty::EarlyBinder<Ty<'static>>>>>,
trait_impl_trait_tys: Table<DefIndex, LazyValue<DefIdMap<ty::EarlyBinder<Ty<'static>>>>>,
doc_link_resolutions: Table<DefIndex, LazyValue<DocLinkResMap>>,
doc_link_traits_in_scope: Table<DefIndex, LazyArray<DefId>>,
assumed_wf_types_for_rpitit: Table<DefIndex, LazyArray<(Ty<'static>, Span)>>,