bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Remove concept of 'completion' from the projection cache

Browse source 
Fixes #88910

When we initially store a `NormalizedTy` in the projection cache,
we discard all obligations that we can (while ensuring that we
don't cause any issues with incremental compilation).

Marking a projection cache entry as 'completed' discards all
obligations associated with it. This can only cause problems,
since any obligations stored in the cache are there for a reason
(e.g. they evaluate to `EvaluatedToOkModuloRegions`).

This commit removes `complete` and `complete_normalized` entirely.
This commit is contained in:
Aaron Hill 2021-09-14 15:38:53 -05:00
parent ec9a1bdc45
commit 055651d1af
No known key found for this signature in database
GPG key ID: B4087E510E98B164
2 changed files with 2 additions and 51 deletions
Download patch file Download diff file Expand all files Collapse all files

12
compiler/rustc_trait_selection/src/traits/select/mod.rs
View file

@ -14,18 +14,17 @@ use super::util;
use super::util::{closure_trait_ref_and_return_type, predicate_for_trait_def};
use super::wf;
use super::DerivedObligationCause;
use super::Normalized;
use super::Obligation;
use super::ObligationCauseCode;
use super::Selection;
use super::SelectionResult;
use super::TraitQueryMode;
use super::{Normalized, ProjectionCacheKey};
use super::{ObligationCause, PredicateObligation, TraitObligation};
use super::{Overflow, SelectionError, Unimplemented};
use crate::infer::{InferCtxt, InferOk, TypeFreshener};
use crate::traits::error_reporting::InferCtxtExt;
use crate::traits::project::ProjectionCacheKeyExt;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::stack::ensure_sufficient_stack;
use rustc_data_structures::sync::Lrc;
@ -574,14 +573,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
match project::poly_project_and_unify_type(self, &project_obligation) {
Ok(Ok(Some(mut subobligations))) => {
self.add_depth(subobligations.iter_mut(), obligation.recursion_depth);
let result = self
.evaluate_predicates_recursively(previous_stack, subobligations);
if let Some(key) =
ProjectionCacheKey::from_poly_projection_predicate(self, data)
{
self.infcx.inner.borrow_mut().projection_cache().complete(key);
}
result
self.evaluate_predicates_recursively(previous_stack, subobligations)
}
Ok(Ok(None)) => Ok(EvaluatedToAmbig),
Ok(Err(project::InProgress)) => Ok(EvaluatedToRecur),