Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

rustdoc: heavily simplify the synthesis of auto trait impls #123340

Merged
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
62 changes: 22 additions & 40 deletions compiler/rustc_trait_selection/src/traits/auto_trait.rs
Original file line number Diff line number Diff line change
Expand Up @@ -6,13 +6,13 @@ use super::*;
use crate::errors::UnableToConstructConstantValue;
use crate::infer::region_constraints::{Constraint, RegionConstraintData};
use crate::traits::project::ProjectAndUnifyResult;

use rustc_data_structures::fx::{FxIndexMap, FxIndexSet, IndexEntry};
use rustc_data_structures::unord::UnordSet;
use rustc_infer::infer::DefineOpaqueTypes;
use rustc_middle::mir::interpret::ErrorHandled;
use rustc_middle::ty::{Region, RegionVid};

use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};

use std::collections::hash_map::Entry;
use std::collections::VecDeque;
use std::iter;

Expand All @@ -25,8 +25,8 @@ pub enum RegionTarget<'tcx> {

#[derive(Default, Debug, Clone)]
pub struct RegionDeps<'tcx> {
larger: FxIndexSet<RegionTarget<'tcx>>,
smaller: FxIndexSet<RegionTarget<'tcx>>,
pub larger: FxIndexSet<RegionTarget<'tcx>>,
pub smaller: FxIndexSet<RegionTarget<'tcx>>,
}

pub enum AutoTraitResult<A> {
Expand All @@ -35,17 +35,10 @@ pub enum AutoTraitResult<A> {
NegativeImpl,
}

#[allow(dead_code)]
impl<A> AutoTraitResult<A> {
fn is_auto(&self) -> bool {
matches!(self, AutoTraitResult::PositiveImpl(_) | AutoTraitResult::NegativeImpl)
}
}

pub struct AutoTraitInfo<'cx> {
pub full_user_env: ty::ParamEnv<'cx>,
pub region_data: RegionConstraintData<'cx>,
pub vid_to_region: FxHashMap<ty::RegionVid, ty::Region<'cx>>,
pub vid_to_region: FxIndexMap<ty::RegionVid, ty::Region<'cx>>,
}

pub struct AutoTraitFinder<'tcx> {
Expand Down Expand Up @@ -88,19 +81,12 @@ impl<'tcx> AutoTraitFinder<'tcx> {

let infcx = tcx.infer_ctxt().build();
let mut selcx = SelectionContext::new(&infcx);
for polarity in [true, false] {
for polarity in [ty::PredicatePolarity::Positive, ty::PredicatePolarity::Negative] {
let result = selcx.select(&Obligation::new(
tcx,
ObligationCause::dummy(),
orig_env,
ty::TraitPredicate {
trait_ref,
polarity: if polarity {
ty::PredicatePolarity::Positive
} else {
ty::PredicatePolarity::Negative
},
},
ty::TraitPredicate { trait_ref, polarity },
));
if let Ok(Some(ImplSource::UserDefined(_))) = result {
debug!(
Expand All @@ -114,7 +100,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
}

let infcx = tcx.infer_ctxt().build();
let mut fresh_preds = FxHashSet::default();
let mut fresh_preds = FxIndexSet::default();

// Due to the way projections are handled by SelectionContext, we need to run
// evaluate_predicates twice: once on the original param env, and once on the result of
Expand Down Expand Up @@ -239,7 +225,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
ty: Ty<'tcx>,
param_env: ty::ParamEnv<'tcx>,
user_env: ty::ParamEnv<'tcx>,
fresh_preds: &mut FxHashSet<ty::Predicate<'tcx>>,
fresh_preds: &mut FxIndexSet<ty::Predicate<'tcx>>,
) -> Option<(ty::ParamEnv<'tcx>, ty::ParamEnv<'tcx>)> {
let tcx = infcx.tcx;

Expand All @@ -252,7 +238,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {

let mut select = SelectionContext::new(infcx);

let mut already_visited = FxHashSet::default();
let mut already_visited = UnordSet::new();
let mut predicates = VecDeque::new();
predicates.push_back(ty::Binder::dummy(ty::TraitPredicate {
trait_ref: ty::TraitRef::new(infcx.tcx, trait_did, [ty]),
Expand Down Expand Up @@ -473,9 +459,9 @@ impl<'tcx> AutoTraitFinder<'tcx> {
fn map_vid_to_region<'cx>(
&self,
regions: &RegionConstraintData<'cx>,
) -> FxHashMap<ty::RegionVid, ty::Region<'cx>> {
let mut vid_map: FxHashMap<RegionTarget<'cx>, RegionDeps<'cx>> = FxHashMap::default();
let mut finished_map = FxHashMap::default();
) -> FxIndexMap<ty::RegionVid, ty::Region<'cx>> {
let mut vid_map = FxIndexMap::<RegionTarget<'cx>, RegionDeps<'cx>>::default();
let mut finished_map = FxIndexMap::default();

for (constraint, _) in &regions.constraints {
match constraint {
Expand Down Expand Up @@ -513,25 +499,22 @@ impl<'tcx> AutoTraitFinder<'tcx> {
}

while !vid_map.is_empty() {
#[allow(rustc::potential_query_instability)]
let target = *vid_map.keys().next().expect("Keys somehow empty");
let deps = vid_map.remove(&target).expect("Entry somehow missing");
let target = *vid_map.keys().next().unwrap();
let deps = vid_map.swap_remove(&target).unwrap();

for smaller in deps.smaller.iter() {
for larger in deps.larger.iter() {
match (smaller, larger) {
(&RegionTarget::Region(_), &RegionTarget::Region(_)) => {
if let Entry::Occupied(v) = vid_map.entry(*smaller) {
if let IndexEntry::Occupied(v) = vid_map.entry(*smaller) {
let smaller_deps = v.into_mut();
smaller_deps.larger.insert(*larger);
// FIXME(#120456) - is `swap_remove` correct?
smaller_deps.larger.swap_remove(&target);
}

if let Entry::Occupied(v) = vid_map.entry(*larger) {
if let IndexEntry::Occupied(v) = vid_map.entry(*larger) {
let larger_deps = v.into_mut();
larger_deps.smaller.insert(*smaller);
// FIXME(#120456) - is `swap_remove` correct?
larger_deps.smaller.swap_remove(&target);
}
}
Expand All @@ -542,24 +525,23 @@ impl<'tcx> AutoTraitFinder<'tcx> {
// Do nothing; we don't care about regions that are smaller than vids.
}
(&RegionTarget::RegionVid(_), &RegionTarget::RegionVid(_)) => {
if let Entry::Occupied(v) = vid_map.entry(*smaller) {
if let IndexEntry::Occupied(v) = vid_map.entry(*smaller) {
let smaller_deps = v.into_mut();
smaller_deps.larger.insert(*larger);
// FIXME(#120456) - is `swap_remove` correct?
smaller_deps.larger.swap_remove(&target);
}

if let Entry::Occupied(v) = vid_map.entry(*larger) {
if let IndexEntry::Occupied(v) = vid_map.entry(*larger) {
let larger_deps = v.into_mut();
larger_deps.smaller.insert(*smaller);
// FIXME(#120456) - is `swap_remove` correct?
larger_deps.smaller.swap_remove(&target);
}
}
}
}
}
}

finished_map
}

Expand Down Expand Up @@ -588,7 +570,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
ty: Ty<'_>,
nested: impl Iterator<Item = PredicateObligation<'tcx>>,
computed_preds: &mut FxIndexSet<ty::Predicate<'tcx>>,
fresh_preds: &mut FxHashSet<ty::Predicate<'tcx>>,
fresh_preds: &mut FxIndexSet<ty::Predicate<'tcx>>,
predicates: &mut VecDeque<ty::PolyTraitPredicate<'tcx>>,
selcx: &mut SelectionContext<'_, 'tcx>,
) -> bool {
Expand Down
Loading
Loading