incr.comp.: Make sure traits_in_scope results are hashed in a stable way.

This commit is contained in:
Michael Woerister 2017-09-14 17:40:37 +02:00
parent 54996837a3
commit 3b75a3dfea
5 changed files with 67 additions and 9 deletions

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@ -168,6 +168,11 @@ impl<'gcx> StableHashingContext<'gcx> {
self.definitions.def_path_hash(def_index)
}
#[inline]
pub fn node_to_hir_id(&self, node_id: ast::NodeId) -> hir::HirId {
self.definitions.node_to_hir_id(node_id)
}
#[inline]
pub fn hash_spans(&self) -> bool {
self.hash_spans

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@ -1160,6 +1160,25 @@ for hir::TraitCandidate {
}
}
impl<'gcx> ToStableHashKey<StableHashingContext<'gcx>> for hir::TraitCandidate {
type KeyType = (DefPathHash, Option<(DefPathHash, hir::ItemLocalId)>);
fn to_stable_hash_key(&self,
hcx: &StableHashingContext<'gcx>)
-> Self::KeyType {
let hir::TraitCandidate {
def_id,
import_id,
} = *self;
let import_id = import_id.map(|node_id| hcx.node_to_hir_id(node_id))
.map(|hir_id| (hcx.local_def_path_hash(hir_id.owner),
hir_id.local_id));
(hcx.def_path_hash(def_id), import_id)
}
}
impl_stable_hash_for!(struct hir::Freevar {
def,
span

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@ -50,8 +50,8 @@ use util::nodemap::{NodeMap, NodeSet, DefIdSet, ItemLocalMap};
use util::nodemap::{FxHashMap, FxHashSet};
use rustc_data_structures::accumulate_vec::AccumulateVec;
use rustc_data_structures::stable_hasher::{HashStable, hash_stable_hashmap,
StableHasher, StableHasherResult};
StableHasher, StableHasherResult,
StableVec};
use arena::{TypedArena, DroplessArena};
use rustc_const_math::{ConstInt, ConstUsize};
use rustc_data_structures::indexed_vec::IndexVec;
@ -828,7 +828,9 @@ pub struct GlobalCtxt<'tcx> {
/// Map indicating what traits are in scope for places where this
/// is relevant; generated by resolve.
trait_map: FxHashMap<DefIndex, Rc<FxHashMap<ItemLocalId, Rc<Vec<TraitCandidate>>>>>,
trait_map: FxHashMap<DefIndex,
Rc<FxHashMap<ItemLocalId,
Rc<StableVec<TraitCandidate>>>>>,
/// Export map produced by name resolution.
export_map: FxHashMap<DefId, Rc<Vec<Export>>>,
@ -1081,15 +1083,14 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
None
};
// FIXME(mw): Each of the Vecs in the trait_map should be brought into
// a deterministic order here. Otherwise we might end up with
// unnecessarily unstable incr. comp. hashes.
let mut trait_map = FxHashMap();
for (k, v) in resolutions.trait_map {
let hir_id = hir.node_to_hir_id(k);
let map = trait_map.entry(hir_id.owner)
.or_insert_with(|| Rc::new(FxHashMap()));
Rc::get_mut(map).unwrap().insert(hir_id.local_id, Rc::new(v));
Rc::get_mut(map).unwrap()
.insert(hir_id.local_id,
Rc::new(StableVec::new(v)));
}
let mut defs = FxHashMap();
for (k, v) in named_region_map.defs {
@ -2103,7 +2104,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
lint::struct_lint_level(self.sess, lint, level, src, None, msg)
}
pub fn in_scope_traits(self, id: HirId) -> Option<Rc<Vec<TraitCandidate>>> {
pub fn in_scope_traits(self, id: HirId) -> Option<Rc<StableVec<TraitCandidate>>> {
self.in_scope_traits_map(id.owner)
.and_then(|map| map.get(&id.local_id).cloned())
}

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@ -42,6 +42,7 @@ use rustc_data_structures::indexed_set::IdxSetBuf;
use rustc_back::PanicStrategy;
use rustc_data_structures::indexed_vec::IndexVec;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::stable_hasher::StableVec;
use std::cell::{RefCell, Cell};
use std::ops::Deref;
@ -259,7 +260,7 @@ define_maps! { <'tcx>
[] fn specializes: specializes_node((DefId, DefId)) -> bool,
[] fn in_scope_traits_map: InScopeTraits(DefIndex)
-> Option<Rc<FxHashMap<ItemLocalId, Rc<Vec<TraitCandidate>>>>>,
-> Option<Rc<FxHashMap<ItemLocalId, Rc<StableVec<TraitCandidate>>>>>,
[] fn module_exports: ModuleExports(DefId) -> Option<Rc<Vec<Export>>>,
[] fn lint_levels: lint_levels_node(CrateNum) -> Rc<lint::LintLevelMap>,

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@ -558,3 +558,35 @@ pub fn hash_stable_hashmap<HCX, K, V, R, SK, F, W>(
entries.hash_stable(hcx, hasher);
}
pub struct StableVec<T>(Vec<T>);
impl<T> StableVec<T> {
pub fn new(v: Vec<T>) -> Self {
StableVec(v)
}
}
impl<T> ::std::ops::Deref for StableVec<T> {
type Target = Vec<T>;
fn deref(&self) -> &Vec<T> {
&self.0
}
}
impl<T, HCX> HashStable<HCX> for StableVec<T>
where T: HashStable<HCX> + ToStableHashKey<HCX>
{
fn hash_stable<W: StableHasherResult>(&self,
hcx: &mut HCX,
hasher: &mut StableHasher<W>) {
let StableVec(ref v) = *self;
let mut sorted: Vec<_> = v.iter()
.map(|x| x.to_stable_hash_key(hcx))
.collect();
sorted.sort_unstable();
sorted.hash_stable(hcx, hasher);
}
}