diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 9fd5cb2a0b33c..254ada7cf1ffb 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -224,7 +224,9 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
debug!("report_overflow_error_cycle: cycle={:?}", cycle);
- self.report_overflow_error(&cycle[0], false);
+ // The 'deepest' obligation is most likely to have a useful
+ // cause 'backtrace'
+ self.report_overflow_error(cycle.iter().max_by_key(|p| p.recursion_depth).unwrap(), false);
}
fn report_selection_error(
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 91b9ad0af356c..7038f16a2c9c4 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -10,6 +10,7 @@ use super::PredicateObligation;
use super::Selection;
use super::SelectionContext;
use super::SelectionError;
+use super::TraitQueryMode;
use super::{
ImplSourceClosureData, ImplSourceDiscriminantKindData, ImplSourceFnPointerData,
ImplSourceGeneratorData, ImplSourcePointeeData, ImplSourceUserDefinedData,
@@ -18,7 +19,7 @@ use super::{Normalized, NormalizedTy, ProjectionCacheEntry, ProjectionCacheKey};
use crate::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
use crate::infer::{InferCtxt, InferOk, LateBoundRegionConversionTime};
-use crate::traits::error_reporting::InferCtxtExt;
+use crate::traits::error_reporting::InferCtxtExt as _;
use rustc_data_structures::stack::ensure_sufficient_stack;
use rustc_errors::ErrorReported;
use rustc_hir::def_id::DefId;
@@ -912,6 +913,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
}
let obligation = Obligation::with_depth(cause.clone(), depth, param_env, projection_ty);
+
match project_type(selcx, &obligation) {
Ok(ProjectedTy::Progress(Progress {
ty: projected_ty,
@@ -925,7 +927,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
let projected_ty = selcx.infcx().resolve_vars_if_possible(projected_ty);
debug!(?projected_ty, ?depth, ?projected_obligations);
- let result = if projected_ty.has_projections() {
+ let mut result = if projected_ty.has_projections() {
let mut normalizer = AssocTypeNormalizer::new(
selcx,
param_env,
@@ -942,8 +944,26 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
Normalized { value: projected_ty, obligations: projected_obligations }
};
- let cache_value = prune_cache_value_obligations(infcx, &result);
- infcx.inner.borrow_mut().projection_cache().insert_ty(cache_key, cache_value);
+ let mut canonical =
+ SelectionContext::with_query_mode(selcx.infcx(), TraitQueryMode::Canonical);
+ result.obligations.drain_filter(|projected_obligation| {
+ // If any global obligations always apply, considering regions, then we don't
+ // need to include them. The `is_global` check rules out inference variables,
+ // so there's no need for the caller of `opt_normalize_projection_type`
+ // to evaluate them.
+ // Note that we do *not* discard obligations that evaluate to
+ // `EvaluatedtoOkModuloRegions`. Evaluating these obligations
+ // inside of a query (e.g. `evaluate_obligation`) can change
+ // the result to `EvaluatedToOkModuloRegions`, while an
+ // `EvaluatedToOk` obligation will never change the result.
+ // See #85360 for more details
+ projected_obligation.is_global(canonical.tcx())
+ && canonical
+ .evaluate_root_obligation(projected_obligation)
+ .map_or(false, |res| res.must_apply_considering_regions())
+ });
+
+ infcx.inner.borrow_mut().projection_cache().insert_ty(cache_key, result.clone());
obligations.extend(result.obligations);
Ok(Some(result.value))
}
@@ -974,49 +994,6 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
}
}
-/// If there are unresolved type variables, then we need to include
-/// any subobligations that bind them, at least until those type
-/// variables are fully resolved.
-fn prune_cache_value_obligations<'a, 'tcx>(
- infcx: &'a InferCtxt<'a, 'tcx>,
- result: &NormalizedTy<'tcx>,
-) -> NormalizedTy<'tcx> {
- if infcx.unresolved_type_vars(&result.value).is_none() {
- return NormalizedTy { value: result.value, obligations: vec![] };
- }
-
- let mut obligations: Vec<_> = result
- .obligations
- .iter()
- .filter(|obligation| {
- let bound_predicate = obligation.predicate.kind();
- match bound_predicate.skip_binder() {
- // We found a `T: Foo<X = U>` predicate, let's check
- // if `U` references any unresolved type
- // variables. In principle, we only care if this
- // projection can help resolve any of the type
- // variables found in `result.value` -- but we just
- // check for any type variables here, for fear of
- // indirect obligations (e.g., we project to `?0`,
- // but we have `T: Foo<X = ?1>` and `?1: Bar<X =
- // ?0>`).
- ty::PredicateKind::Projection(data) => {
- infcx.unresolved_type_vars(&bound_predicate.rebind(data.ty)).is_some()
- }
-
- // We are only interested in `T: Foo<X = U>` predicates, whre
- // `U` references one of `unresolved_type_vars`. =)
- _ => false,
- }
- })
- .cloned()
- .collect();
-
- obligations.shrink_to_fit();
-
- NormalizedTy { value: result.value, obligations }
-}
-
/// If we are projecting `<T as Trait>::Item`, but `T: Trait` does not
/// hold. In various error cases, we cannot generate a valid
/// normalized projection. Therefore, we create an inference variable
diff --git a/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs b/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs
index 2dc48e47efccd..032d402fec045 100644
--- a/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/evaluate_obligation.rs
@@ -71,7 +71,7 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'tcx> {
// Run canonical query. If overflow occurs, rerun from scratch but this time
// in standard trait query mode so that overflow is handled appropriately
// within `SelectionContext`.
- self.tcx.evaluate_obligation(c_pred)
+ self.tcx.at(obligation.cause.span(self.tcx)).evaluate_obligation(c_pred)
}
// Helper function that canonicalizes and runs the query. If an
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 5214277a37d53..22013fb79cf79 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -682,7 +682,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
});
- debug!(?result);
+ debug!("finished: {:?} from {:?}", result, obligation);
result
}
diff --git a/src/test/incremental/const-generics/hash-tyvid-regression-1.rs b/src/test/incremental/const-generics/hash-tyvid-regression-1.rs
index b5a0108a0a397..5ff7b19d8945e 100644
--- a/src/test/incremental/const-generics/hash-tyvid-regression-1.rs
+++ b/src/test/incremental/const-generics/hash-tyvid-regression-1.rs
@@ -9,7 +9,8 @@ where
use std::convert::TryFrom;
<[T; N.get()]>::try_from(())
//~^ error: the trait bound
- //~^^ error: mismatched types
+ //~| error: the trait bound
+ //~| error: mismatched types
}
fn main() {}
diff --git a/src/test/ui/impl-trait/auto-trait-leak.stderr b/src/test/ui/impl-trait/auto-trait-leak.stderr
index 3eb141cc2bb55..a31c104d8f58b 100644
--- a/src/test/ui/impl-trait/auto-trait-leak.stderr
+++ b/src/test/ui/impl-trait/auto-trait-leak.stderr
@@ -30,10 +30,10 @@ note: ...which requires building MIR for `cycle1`...
LL | fn cycle1() -> impl Clone {
| ^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires type-checking `cycle1`...
- --> $DIR/auto-trait-leak.rs:12:1
+ --> $DIR/auto-trait-leak.rs:14:5
|
-LL | fn cycle1() -> impl Clone {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | send(cycle2().clone());
+ | ^^^^
= note: ...which requires evaluating trait selection obligation `impl std::clone::Clone: std::marker::Send`...
note: ...which requires computing type of `cycle2::{opaque#0}`...
--> $DIR/auto-trait-leak.rs:19:16
@@ -66,10 +66,10 @@ note: ...which requires building MIR for `cycle2`...
LL | fn cycle2() -> impl Clone {
| ^^^^^^^^^^^^^^^^^^^^^^^^^
note: ...which requires type-checking `cycle2`...
- --> $DIR/auto-trait-leak.rs:19:1
+ --> $DIR/auto-trait-leak.rs:20:5
|
-LL | fn cycle2() -> impl Clone {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | send(cycle1().clone());
+ | ^^^^
= note: ...which requires evaluating trait selection obligation `impl std::clone::Clone: std::marker::Send`...
= note: ...which again requires computing type of `cycle1::{opaque#0}`, completing the cycle
note: cycle used when checking item types in top-level module
diff --git a/src/test/ui/traits/cycle-cache-err-60010.rs b/src/test/ui/traits/cycle-cache-err-60010.rs
index 98bfcb8d67b51..94e718317e7c8 100644
--- a/src/test/ui/traits/cycle-cache-err-60010.rs
+++ b/src/test/ui/traits/cycle-cache-err-60010.rs
@@ -25,6 +25,7 @@ struct Runtime<DB: Database> {
}
struct SalsaStorage {
_parse: <ParseQuery as Query<RootDatabase>>::Data,
+ //~^ ERROR overflow
}
impl Database for RootDatabase {
@@ -67,7 +68,6 @@ pub(crate) fn goto_implementation(db: &RootDatabase) -> u32 {
// we used to fail to report an error here because we got the
// caching wrong.
SourceDatabase::parse(db);
- //~^ ERROR overflow
22
}
diff --git a/src/test/ui/traits/cycle-cache-err-60010.stderr b/src/test/ui/traits/cycle-cache-err-60010.stderr
index 565899677bf1a..9452e11e302e3 100644
--- a/src/test/ui/traits/cycle-cache-err-60010.stderr
+++ b/src/test/ui/traits/cycle-cache-err-60010.stderr
@@ -1,8 +1,8 @@
error[E0275]: overflow evaluating the requirement `SalsaStorage: RefUnwindSafe`
- --> $DIR/cycle-cache-err-60010.rs:69:5
+ --> $DIR/cycle-cache-err-60010.rs:27:13
|
-LL | SourceDatabase::parse(db);
- | ^^^^^^^^^^^^^^^^^^^^^
+LL | _parse: <ParseQuery as Query<RootDatabase>>::Data,
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: required because it appears within the type `*const SalsaStorage`
= note: required because it appears within the type `Unique<SalsaStorage>`
@@ -18,15 +18,15 @@ note: required because it appears within the type `RootDatabase`
LL | struct RootDatabase {
| ^^^^^^^^^^^^
note: required because of the requirements on the impl of `SourceDatabase` for `RootDatabase`
- --> $DIR/cycle-cache-err-60010.rs:43:9
+ --> $DIR/cycle-cache-err-60010.rs:44:9
|
LL | impl<T> SourceDatabase for T
| ^^^^^^^^^^^^^^ ^
-note: required by `SourceDatabase::parse`
- --> $DIR/cycle-cache-err-60010.rs:14:5
+note: required because of the requirements on the impl of `Query<RootDatabase>` for `ParseQuery`
+ --> $DIR/cycle-cache-err-60010.rs:37:10
|
-LL | fn parse(&self) {
- | ^^^^^^^^^^^^^^^
+LL | impl<DB> Query<DB> for ParseQuery
+ | ^^^^^^^^^ ^^^^^^^^^^
error: aborting due to previous error
diff --git a/src/test/ui/traits/inductive-overflow/lifetime.rs b/src/test/ui/traits/inductive-overflow/lifetime.rs
index 072c46bc21e9a..8be42fc4ad07f 100644
--- a/src/test/ui/traits/inductive-overflow/lifetime.rs
+++ b/src/test/ui/traits/inductive-overflow/lifetime.rs
@@ -15,8 +15,8 @@ impl<'a> Y for C<'a> {
struct C<'a>(&'a ());
struct X<T: Y>(T::P);
-impl<T: NotAuto> NotAuto for Box<T> {}
-impl<T: Y> NotAuto for X<T> where T::P: NotAuto {} //~ NOTE: required
+impl<T: NotAuto> NotAuto for Box<T> {} //~ NOTE: required
+impl<T: Y> NotAuto for X<T> where T::P: NotAuto {}
impl<'a> NotAuto for C<'a> {}
fn is_send<S: NotAuto>() {}
@@ -26,6 +26,6 @@ fn main() {
// Should only be a few notes.
is_send::<X<C<'static>>>();
//~^ ERROR overflow evaluating
- //~| 2 redundant requirements hidden
+ //~| 3 redundant requirements hidden
//~| required because of
}
diff --git a/src/test/ui/traits/inductive-overflow/lifetime.stderr b/src/test/ui/traits/inductive-overflow/lifetime.stderr
index 2905deb940f3a..2ffcdb0e1c6de 100644
--- a/src/test/ui/traits/inductive-overflow/lifetime.stderr
+++ b/src/test/ui/traits/inductive-overflow/lifetime.stderr
@@ -1,15 +1,15 @@
-error[E0275]: overflow evaluating the requirement `Box<X<C<'_>>>: NotAuto`
+error[E0275]: overflow evaluating the requirement `X<C<'_>>: NotAuto`
--> $DIR/lifetime.rs:27:5
|
LL | is_send::<X<C<'static>>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
-note: required because of the requirements on the impl of `NotAuto` for `X<C<'_>>`
- --> $DIR/lifetime.rs:19:12
+note: required because of the requirements on the impl of `NotAuto` for `Box<X<C<'_>>>`
+ --> $DIR/lifetime.rs:18:18
|
-LL | impl<T: Y> NotAuto for X<T> where T::P: NotAuto {}
- | ^^^^^^^ ^^^^
- = note: 2 redundant requirements hidden
+LL | impl<T: NotAuto> NotAuto for Box<T> {}
+ | ^^^^^^^ ^^^^^^
+ = note: 3 redundant requirements hidden
= note: required because of the requirements on the impl of `NotAuto` for `X<C<'static>>`
note: required by a bound in `is_send`
--> $DIR/lifetime.rs:22:15
diff --git a/src/test/ui/traits/inductive-overflow/simultaneous.stderr b/src/test/ui/traits/inductive-overflow/simultaneous.stderr
index 7eb1c9ffb3b49..230c2638c5003 100644
--- a/src/test/ui/traits/inductive-overflow/simultaneous.stderr
+++ b/src/test/ui/traits/inductive-overflow/simultaneous.stderr
@@ -1,4 +1,4 @@
-error[E0275]: overflow evaluating the requirement `{integer}: Tweedledee`
+error[E0275]: overflow evaluating the requirement `{integer}: Tweedledum`
--> $DIR/simultaneous.rs:18:5
|
LL | is_ee(4);
diff --git a/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr b/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
index ac7bbd272c771..86b3f87d34d03 100644
--- a/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
+++ b/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
@@ -5,10 +5,10 @@ LL | type Foo = impl std::fmt::Debug;
| ^^^^^^^^^^^^^^^^^^^^
|
note: ...which requires type-checking `m::bar`...
- --> $DIR/auto-trait-leakage3.rs:14:5
+ --> $DIR/auto-trait-leakage3.rs:15:9
|
-LL | pub fn bar() {
- | ^^^^^^^^^^^^
+LL | is_send(foo());
+ | ^^^^^^^
= note: ...which requires evaluating trait selection obligation `impl std::fmt::Debug: std::marker::Send`...
= note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
note: cycle used when checking item types in module `m`
diff --git a/src/test/ui/type-alias-impl-trait/inference-cycle.stderr b/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
index ac0ca8e048cb0..4c5921c7f660b 100644
--- a/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
+++ b/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
@@ -5,10 +5,10 @@ LL | type Foo = impl std::fmt::Debug;
| ^^^^^^^^^^^^^^^^^^^^
|
note: ...which requires type-checking `m::bar`...
- --> $DIR/inference-cycle.rs:14:5
+ --> $DIR/inference-cycle.rs:15:9
|
-LL | pub fn bar() {
- | ^^^^^^^^^^^^
+LL | is_send(foo()); // Today: error
+ | ^^^^^^^
= note: ...which requires evaluating trait selection obligation `impl std::fmt::Debug: std::marker::Send`...
= note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
note: cycle used when checking item types in module `m`